Merge tag 'v3.9-rc3' into drm-intel-next-queued

Backmerge so that I can merge Imre Deak's coalesced sg entries fixes,
which depend upon the new for_each_sg_page introduce in

commit a321e91b6d73ed011ffceed384c40d2785cf723b
Author: Imre Deak <imre.deak@intel.com>
Date:   Wed Feb 27 17:02:56 2013 -0800

    lib/scatterlist: add simple page iterator

The merge itself is just two trivial conflicts:

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

118 files changed, 5435 insertions, 4514 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index 6c072b6da239..bbde5f1a4486 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -7,7 +7,7 @@ obj-y     = fork.o exec_domain.o panic.o printk.o \
 	    sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \
 	    signal.o sys.o kmod.o workqueue.o pid.o task_work.o \
 	    rcupdate.o extable.o params.o posix-timers.o \
-	    kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
+	    kthread.o wait.o sys_ni.o posix-cpu-timers.o mutex.o \
 	    hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
 	    notifier.o ksysfs.o cred.o \
 	    async.o range.o groups.o lglock.o smpboot.o
@@ -25,9 +25,7 @@ endif
 obj-y += sched/
 obj-y += power/
 
-ifeq ($(CONFIG_CHECKPOINT_RESTORE),y)
-obj-$(CONFIG_X86) += kcmp.o
-endif
+obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o
 obj-$(CONFIG_FREEZER) += freezer.o
 obj-$(CONFIG_PROFILING) += profile.o
 obj-$(CONFIG_STACKTRACE) += stacktrace.o
@@ -127,11 +125,19 @@ $(obj)/config_data.h: $(obj)/config_data.gz FORCE
 
 $(obj)/time.o: $(obj)/timeconst.h
 
-quiet_cmd_timeconst  = TIMEC   $@
-      cmd_timeconst  = $(PERL) $< $(CONFIG_HZ) > $@
+quiet_cmd_hzfile = HZFILE  $@
+      cmd_hzfile = echo "hz=$(CONFIG_HZ)" > $@
+
+targets += hz.bc
+$(obj)/hz.bc: $(objtree)/include/config/hz.h FORCE
+	$(call if_changed,hzfile)
+
+quiet_cmd_bc  = BC      $@
+      cmd_bc  = bc -q $(filter-out FORCE,$^) > $@
+
 targets += timeconst.h
-$(obj)/timeconst.h: $(src)/timeconst.pl FORCE
-	$(call if_changed,timeconst)
+$(obj)/timeconst.h: $(obj)/hz.bc $(src)/timeconst.bc FORCE
+	$(call if_changed,bc)
 
 ifeq ($(CONFIG_MODULE_SIG),y)
 #
@@ -153,23 +159,7 @@ kernel/modsign_certificate.o: signing_key.x509 extra_certificates
 # fail and that the kernel may be used afterwards.
 #
 ###############################################################################
-sign_key_with_hash :=
-ifeq ($(CONFIG_MODULE_SIG_SHA1),y)
-sign_key_with_hash := -sha1
-endif
-ifeq ($(CONFIG_MODULE_SIG_SHA224),y)
-sign_key_with_hash := -sha224
-endif
-ifeq ($(CONFIG_MODULE_SIG_SHA256),y)
-sign_key_with_hash := -sha256
-endif
-ifeq ($(CONFIG_MODULE_SIG_SHA384),y)
-sign_key_with_hash := -sha384
-endif
-ifeq ($(CONFIG_MODULE_SIG_SHA512),y)
-sign_key_with_hash := -sha512
-endif
-ifeq ($(sign_key_with_hash),)
+ifndef CONFIG_MODULE_SIG_HASH
 $(error Could not determine digest type to use from kernel config)
 endif
 
@@ -182,8 +172,8 @@ signing_key.priv signing_key.x509: x509.genkey
 	@echo "### needs to be run as root, and uses a hardware random"
 	@echo "### number generator if one is available."
 	@echo "###"
-	openssl req -new -nodes -utf8 $(sign_key_with_hash) -days 36500 -batch \
-		-x509 -config x509.genkey \
+	openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
+		-batch -x509 -config x509.genkey \
 		-outform DER -out signing_key.x509 \
 		-keyout signing_key.priv
 	@echo "###"
diff --git a/kernel/acct.c b/kernel/acct.c
index 051e071a06e7..b9bd7f098ee5 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -205,7 +205,7 @@ static int acct_on(struct filename *pathname)
 	if (IS_ERR(file))
 		return PTR_ERR(file);
 
-	if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) {
+	if (!S_ISREG(file_inode(file)->i_mode)) {
 		filp_close(file, NULL);
 		return -EACCES;
 	}
@@ -566,6 +566,7 @@ out:
 void acct_collect(long exitcode, int group_dead)
 {
 	struct pacct_struct *pacct = &current->signal->pacct;
+	cputime_t utime, stime;
 	unsigned long vsize = 0;
 
 	if (group_dead && current->mm) {
@@ -593,8 +594,9 @@ void acct_collect(long exitcode, int group_dead)
 		pacct->ac_flag |= ACORE;
 	if (current->flags & PF_SIGNALED)
 		pacct->ac_flag |= AXSIG;
-	pacct->ac_utime += current->utime;
-	pacct->ac_stime += current->stime;
+	task_cputime(current, &utime, &stime);
+	pacct->ac_utime += utime;
+	pacct->ac_stime += stime;
 	pacct->ac_minflt += current->min_flt;
 	pacct->ac_majflt += current->maj_flt;
 	spin_unlock_irq(&current->sighand->siglock);
diff --git a/kernel/async.c b/kernel/async.c
index 6f34904a0b53..8ddee2c3e5b0 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -57,65 +57,52 @@ asynchronous and synchronous parts of the kernel.
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 
+#include "workqueue_internal.h"
+
 static async_cookie_t next_cookie = 1;
 
-#define MAX_WORK	32768
+#define MAX_WORK		32768
+#define ASYNC_COOKIE_MAX	ULLONG_MAX	/* infinity cookie */
 
-static LIST_HEAD(async_pending);
-static ASYNC_DOMAIN(async_running);
-static LIST_HEAD(async_domains);
+static LIST_HEAD(async_global_pending);	/* pending from all registered doms */
+static ASYNC_DOMAIN(async_dfl_domain);
 static DEFINE_SPINLOCK(async_lock);
-static DEFINE_MUTEX(async_register_mutex);
 
 struct async_entry {
-	struct list_head	list;
+	struct list_head	domain_list;
+	struct list_head	global_list;
 	struct work_struct	work;
 	async_cookie_t		cookie;
 	async_func_ptr		*func;
 	void			*data;
-	struct async_domain	*running;
+	struct async_domain	*domain;
 };
 
 static DECLARE_WAIT_QUEUE_HEAD(async_done);
 
 static atomic_t entry_count;
 
-
-/*
- * MUST be called with the lock held!
- */
-static async_cookie_t  __lowest_in_progress(struct async_domain *running)
+static async_cookie_t lowest_in_progress(struct async_domain *domain)
 {
-	async_cookie_t first_running = next_cookie;	/* infinity value */
-	async_cookie_t first_pending = next_cookie;	/* ditto */
-	struct async_entry *entry;
+	struct async_entry *first = NULL;
+	async_cookie_t ret = ASYNC_COOKIE_MAX;
+	unsigned long flags;
 
-	/*
-	 * Both running and pending lists are sorted but not disjoint.
-	 * Take the first cookies from both and return the min.
-	 */
-	if (!list_empty(&running->domain)) {
-		entry = list_first_entry(&running->domain, typeof(*entry), list);
-		first_running = entry->cookie;
-	}
+	spin_lock_irqsave(&async_lock, flags);
 
-	list_for_each_entry(entry, &async_pending, list) {
-		if (entry->running == running) {
-			first_pending = entry->cookie;
-			break;
-		}
+	if (domain) {
+		if (!list_empty(&domain->pending))
+			first = list_first_entry(&domain->pending,
+					struct async_entry, domain_list);
+	} else {
+		if (!list_empty(&async_global_pending))
+			first = list_first_entry(&async_global_pending,
+					struct async_entry, global_list);
 	}
 
-	return min(first_running, first_pending);
-}
-
-static async_cookie_t  lowest_in_progress(struct async_domain *running)
-{
-	unsigned long flags;
-	async_cookie_t ret;
+	if (first)
+		ret = first->cookie;
 
-	spin_lock_irqsave(&async_lock, flags);
-	ret = __lowest_in_progress(running);
 	spin_unlock_irqrestore(&async_lock, flags);
 	return ret;
 }
@@ -127,20 +114,10 @@ static void async_run_entry_fn(struct work_struct *work)
 {
 	struct async_entry *entry =
 		container_of(work, struct async_entry, work);
-	struct async_entry *pos;
 	unsigned long flags;
 	ktime_t uninitialized_var(calltime), delta, rettime;
-	struct async_domain *running = entry->running;
 
-	/* 1) move self to the running queue, make sure it stays sorted */
-	spin_lock_irqsave(&async_lock, flags);
-	list_for_each_entry_reverse(pos, &running->domain, list)
-		if (entry->cookie < pos->cookie)
-			break;
-	list_move_tail(&entry->list, &pos->list);
-	spin_unlock_irqrestore(&async_lock, flags);
-
-	/* 2) run (and print duration) */
+	/* 1) run (and print duration) */
 	if (initcall_debug && system_state == SYSTEM_BOOTING) {
 		printk(KERN_DEBUG "calling  %lli_%pF @ %i\n",
 			(long long)entry->cookie,
@@ -157,23 +134,22 @@ static void async_run_entry_fn(struct work_struct *work)
 			(long long)ktime_to_ns(delta) >> 10);
 	}
 
-	/* 3) remove self from the running queue */
+	/* 2) remove self from the pending queues */
 	spin_lock_irqsave(&async_lock, flags);
-	list_del(&entry->list);
-	if (running->registered && --running->count == 0)
-		list_del_init(&running->node);
+	list_del_init(&entry->domain_list);
+	list_del_init(&entry->global_list);
 
-	/* 4) free the entry */
+	/* 3) free the entry */
 	kfree(entry);
 	atomic_dec(&entry_count);
 
 	spin_unlock_irqrestore(&async_lock, flags);
 
-	/* 5) wake up any waiters */
+	/* 4) wake up any waiters */
 	wake_up(&async_done);
 }
 
-static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct async_domain *running)
+static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct async_domain *domain)
 {
 	struct async_entry *entry;
 	unsigned long flags;
@@ -196,16 +172,22 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct a
 		ptr(data, newcookie);
 		return newcookie;
 	}
+	INIT_LIST_HEAD(&entry->domain_list);
+	INIT_LIST_HEAD(&entry->global_list);
 	INIT_WORK(&entry->work, async_run_entry_fn);
 	entry->func = ptr;
 	entry->data = data;
-	entry->running = running;
+	entry->domain = domain;
 
 	spin_lock_irqsave(&async_lock, flags);
+
+	/* allocate cookie and queue */
 	newcookie = entry->cookie = next_cookie++;
-	list_add_tail(&entry->list, &async_pending);
-	if (running->registered && running->count++ == 0)
-		list_add_tail(&running->node, &async_domains);
+
+	list_add_tail(&entry->domain_list, &domain->pending);
+	if (domain->registered)
+		list_add_tail(&entry->global_list, &async_global_pending);
+
 	atomic_inc(&entry_count);
 	spin_unlock_irqrestore(&async_lock, flags);
 
@@ -228,7 +210,7 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct a
  */
 async_cookie_t async_schedule(async_func_ptr *ptr, void *data)
 {
-	return __async_schedule(ptr, data, &async_running);
+	return __async_schedule(ptr, data, &async_dfl_domain);
 }
 EXPORT_SYMBOL_GPL(async_schedule);
 
@@ -236,18 +218,18 @@ EXPORT_SYMBOL_GPL(async_schedule);
  * async_schedule_domain - schedule a function for asynchronous execution within a certain domain
  * @ptr: function to execute asynchronously
  * @data: data pointer to pass to the function
- * @running: running list for the domain
+ * @domain: the domain
  *
  * Returns an async_cookie_t that may be used for checkpointing later.
- * @running may be used in the async_synchronize_*_domain() functions
- * to wait within a certain synchronization domain rather than globally.
- * A synchronization domain is specified via the running queue @running to use.
- * Note: This function may be called from atomic or non-atomic contexts.
+ * @domain may be used in the async_synchronize_*_domain() functions to
+ * wait within a certain synchronization domain rather than globally.  A
+ * synchronization domain is specified via @domain.  Note: This function
+ * may be called from atomic or non-atomic contexts.
  */
 async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data,
-				     struct async_domain *running)
+				     struct async_domain *domain)
 {
-	return __async_schedule(ptr, data, running);
+	return __async_schedule(ptr, data, domain);
 }
 EXPORT_SYMBOL_GPL(async_schedule_domain);
 
@@ -258,18 +240,7 @@ EXPORT_SYMBOL_GPL(async_schedule_domain);
  */
 void async_synchronize_full(void)
 {
-	mutex_lock(&async_register_mutex);
-	do {
-		struct async_domain *domain = NULL;
-
-		spin_lock_irq(&async_lock);
-		if (!list_empty(&async_domains))
-			domain = list_first_entry(&async_domains, typeof(*domain), node);
-		spin_unlock_irq(&async_lock);
-
-		async_synchronize_cookie_domain(next_cookie, domain);
-	} while (!list_empty(&async_domains));
-	mutex_unlock(&async_register_mutex);
+	async_synchronize_full_domain(NULL);
 }
 EXPORT_SYMBOL_GPL(async_synchronize_full);
 
@@ -284,51 +255,45 @@ EXPORT_SYMBOL_GPL(async_synchronize_full);
  */
 void async_unregister_domain(struct async_domain *domain)
 {
-	mutex_lock(&async_register_mutex);
 	spin_lock_irq(&async_lock);
-	WARN_ON(!domain->registered || !list_empty(&domain->node) ||
-		!list_empty(&domain->domain));
+	WARN_ON(!domain->registered || !list_empty(&domain->pending));
 	domain->registered = 0;
 	spin_unlock_irq(&async_lock);
-	mutex_unlock(&async_register_mutex);
 }
 EXPORT_SYMBOL_GPL(async_unregister_domain);
 
 /**
  * async_synchronize_full_domain - synchronize all asynchronous function within a certain domain
- * @domain: running list to synchronize on
+ * @domain: the domain to synchronize
  *
  * This function waits until all asynchronous function calls for the
- * synchronization domain specified by the running list @domain have been done.
+ * synchronization domain specified by @domain have been done.
  */
 void async_synchronize_full_domain(struct async_domain *domain)
 {
-	async_synchronize_cookie_domain(next_cookie, domain);
+	async_synchronize_cookie_domain(ASYNC_COOKIE_MAX, domain);
 }
 EXPORT_SYMBOL_GPL(async_synchronize_full_domain);
 
 /**
  * async_synchronize_cookie_domain - synchronize asynchronous function calls within a certain domain with cookie checkpointing
  * @cookie: async_cookie_t to use as checkpoint
- * @running: running list to synchronize on
+ * @domain: the domain to synchronize (%NULL for all registered domains)
  *
  * This function waits until all asynchronous function calls for the
- * synchronization domain specified by running list @running submitted
- * prior to @cookie have been done.
+ * synchronization domain specified by @domain submitted prior to @cookie
+ * have been done.
  */
-void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain *running)
+void async_synchronize_cookie_domain(async_cookie_t cookie, struct async_domain *domain)
 {
 	ktime_t uninitialized_var(starttime), delta, endtime;
 
-	if (!running)
-		return;
-
 	if (initcall_debug && system_state == SYSTEM_BOOTING) {
 		printk(KERN_DEBUG "async_waiting @ %i\n", task_pid_nr(current));
 		starttime = ktime_get();
 	}
 
-	wait_event(async_done, lowest_in_progress(running) >= cookie);
+	wait_event(async_done, lowest_in_progress(domain) >= cookie);
 
 	if (initcall_debug && system_state == SYSTEM_BOOTING) {
 		endtime = ktime_get();
@@ -350,6 +315,18 @@ EXPORT_SYMBOL_GPL(async_synchronize_cookie_domain);
  */
 void async_synchronize_cookie(async_cookie_t cookie)
 {
-	async_synchronize_cookie_domain(cookie, &async_running);
+	async_synchronize_cookie_domain(cookie, &async_dfl_domain);
 }
 EXPORT_SYMBOL_GPL(async_synchronize_cookie);
+
+/**
+ * current_is_async - is %current an async worker task?
+ *
+ * Returns %true if %current is an async worker task.
+ */
+bool current_is_async(void)
+{
+	struct worker *worker = current_wq_worker();
+
+	return worker && worker->current_func == async_run_entry_fn;
+}
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 4855892798fd..a32f9432666c 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -52,7 +52,7 @@
 #include <linux/module.h>
 #include <linux/delayacct.h>
 #include <linux/cgroupstats.h>
-#include <linux/hash.h>
+#include <linux/hashtable.h>
 #include <linux/namei.h>
 #include <linux/pid_namespace.h>
 #include <linux/idr.h>
@@ -376,22 +376,18 @@ static int css_set_count;
  * account cgroups in empty hierarchies.
  */
 #define CSS_SET_HASH_BITS	7
-#define CSS_SET_TABLE_SIZE	(1 << CSS_SET_HASH_BITS)
-static struct hlist_head css_set_table[CSS_SET_TABLE_SIZE];
+static DEFINE_HASHTABLE(css_set_table, CSS_SET_HASH_BITS);
 
-static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[])
+static unsigned long css_set_hash(struct cgroup_subsys_state *css[])
 {
 	int i;
-	int index;
-	unsigned long tmp = 0UL;
+	unsigned long key = 0UL;
 
 	for (i = 0; i < CGROUP_SUBSYS_COUNT; i++)
-		tmp += (unsigned long)css[i];
-	tmp = (tmp >> 16) ^ tmp;
+		key += (unsigned long)css[i];
+	key = (key >> 16) ^ key;
 
-	index = hash_long(tmp, CSS_SET_HASH_BITS);
-
-	return &css_set_table[index];
+	return key;
 }
 
 /* We don't maintain the lists running through each css_set to its
@@ -418,7 +414,7 @@ static void __put_css_set(struct css_set *cg, int taskexit)
 	}
 
 	/* This css_set is dead. unlink it and release cgroup refcounts */
-	hlist_del(&cg->hlist);
+	hash_del(&cg->hlist);
 	css_set_count--;
 
 	list_for_each_entry_safe(link, saved_link, &cg->cg_links,
@@ -426,12 +422,20 @@ static void __put_css_set(struct css_set *cg, int taskexit)
 		struct cgroup *cgrp = link->cgrp;
 		list_del(&link->cg_link_list);
 		list_del(&link->cgrp_link_list);
+
+		/*
+		 * We may not be holding cgroup_mutex, and if cgrp->count is
+		 * dropped to 0 the cgroup can be destroyed at any time, hence
+		 * rcu_read_lock is used to keep it alive.
+		 */
+		rcu_read_lock();
 		if (atomic_dec_and_test(&cgrp->count) &&
 		    notify_on_release(cgrp)) {
 			if (taskexit)
 				set_bit(CGRP_RELEASABLE, &cgrp->flags);
 			check_for_release(cgrp);
 		}
+		rcu_read_unlock();
 
 		kfree(link);
 	}
@@ -550,9 +554,8 @@ static struct css_set *find_existing_css_set(
 {
 	int i;
 	struct cgroupfs_root *root = cgrp->root;
-	struct hlist_head *hhead;
-	struct hlist_node *node;
 	struct css_set *cg;
+	unsigned long key;
 
 	/*
 	 * Build the set of subsystem state objects that we want to see in the
@@ -572,8 +575,8 @@ static struct css_set *find_existing_css_set(
 		}
 	}
 
-	hhead = css_set_hash(template);
-	hlist_for_each_entry(cg, node, hhead, hlist) {
+	key = css_set_hash(template);
+	hash_for_each_possible(css_set_table, cg, hlist, key) {
 		if (!compare_css_sets(cg, oldcg, cgrp, template))
 			continue;
 
@@ -657,8 +660,8 @@ static struct css_set *find_css_set(
 
 	struct list_head tmp_cg_links;
 
-	struct hlist_head *hhead;
 	struct cg_cgroup_link *link;
+	unsigned long key;
 
 	/* First see if we already have a cgroup group that matches
 	 * the desired set */
@@ -704,8 +707,8 @@ static struct css_set *find_css_set(
 	css_set_count++;
 
 	/* Add this cgroup group to the hash table */
-	hhead = css_set_hash(res->subsys);
-	hlist_add_head(&res->hlist, hhead);
+	key = css_set_hash(res->subsys);
+	hash_add(css_set_table, &res->hlist, key);
 
 	write_unlock(&css_set_lock);
 
@@ -856,47 +859,54 @@ static struct inode *cgroup_new_inode(umode_t mode, struct super_block *sb)
 	return inode;
 }
 
-static void cgroup_diput(struct dentry *dentry, struct inode *inode)
+static void cgroup_free_fn(struct work_struct *work)
 {
-	/* is dentry a directory ? if so, kfree() associated cgroup */
-	if (S_ISDIR(inode->i_mode)) {
-		struct cgroup *cgrp = dentry->d_fsdata;
-		struct cgroup_subsys *ss;
-		BUG_ON(!(cgroup_is_removed(cgrp)));
-		/* It's possible for external users to be holding css
-		 * reference counts on a cgroup; css_put() needs to
-		 * be able to access the cgroup after decrementing
-		 * the reference count in order to know if it needs to
-		 * queue the cgroup to be handled by the release
-		 * agent */
-		synchronize_rcu();
+	struct cgroup *cgrp = container_of(work, struct cgroup, free_work);
+	struct cgroup_subsys *ss;
 
-		mutex_lock(&cgroup_mutex);
-		/*
-		 * Release the subsystem state objects.
-		 */
-		for_each_subsys(cgrp->root, ss)
-			ss->css_free(cgrp);
+	mutex_lock(&cgroup_mutex);
+	/*
+	 * Release the subsystem state objects.
+	 */
+	for_each_subsys(cgrp->root, ss)
+		ss->css_free(cgrp);
 
-		cgrp->root->number_of_cgroups--;
-		mutex_unlock(&cgroup_mutex);
+	cgrp->root->number_of_cgroups--;
+	mutex_unlock(&cgroup_mutex);
 
-		/*
-		 * Drop the active superblock reference that we took when we
-		 * created the cgroup
-		 */
-		deactivate_super(cgrp->root->sb);
+	/*
+	 * Drop the active superblock reference that we took when we
+	 * created the cgroup
+	 */
+	deactivate_super(cgrp->root->sb);
 
-		/*
-		 * if we're getting rid of the cgroup, refcount should ensure
-		 * that there are no pidlists left.
-		 */
-		BUG_ON(!list_empty(&cgrp->pidlists));
+	/*
+	 * if we're getting rid of the cgroup, refcount should ensure
+	 * that there are no pidlists left.
+	 */
+	BUG_ON(!list_empty(&cgrp->pidlists));
+
+	simple_xattrs_free(&cgrp->xattrs);
+
+	ida_simple_remove(&cgrp->root->cgroup_ida, cgrp->id);
+	kfree(cgrp);
+}
 
-		simple_xattrs_free(&cgrp->xattrs);
+static void cgroup_free_rcu(struct rcu_head *head)
+{
+	struct cgroup *cgrp = container_of(head, struct cgroup, rcu_head);
+
+	schedule_work(&cgrp->free_work);
+}
+
+static void cgroup_diput(struct dentry *dentry, struct inode *inode)
+{
+	/* is dentry a directory ? if so, kfree() associated cgroup */
+	if (S_ISDIR(inode->i_mode)) {
+		struct cgroup *cgrp = dentry->d_fsdata;
 
-		ida_simple_remove(&cgrp->root->cgroup_ida, cgrp->id);
-		kfree_rcu(cgrp, rcu_head);
+		BUG_ON(!(cgroup_is_removed(cgrp)));
+		call_rcu(&cgrp->rcu_head, cgroup_free_rcu);
 	} else {
 		struct cfent *cfe = __d_cfe(dentry);
 		struct cgroup *cgrp = dentry->d_parent->d_fsdata;
@@ -925,13 +935,17 @@ static void remove_dir(struct dentry *d)
 	dput(parent);
 }
 
-static int cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
+static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
 {
 	struct cfent *cfe;
 
 	lockdep_assert_held(&cgrp->dentry->d_inode->i_mutex);
 	lockdep_assert_held(&cgroup_mutex);
 
+	/*
+	 * If we're doing cleanup due to failure of cgroup_create(),
+	 * the corresponding @cfe may not exist.
+	 */
 	list_for_each_entry(cfe, &cgrp->files, node) {
 		struct dentry *d = cfe->dentry;
 
@@ -944,9 +958,8 @@ static int cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft)
 		list_del_init(&cfe->node);
 		dput(d);
 
-		return 0;
+		break;
 	}
-	return -ENOENT;
 }
 
 /**
@@ -1083,7 +1096,6 @@ static int rebind_subsystems(struct cgroupfs_root *root,
 		}
 	}
 	root->subsys_mask = root->actual_subsys_mask = final_subsys_mask;
-	synchronize_rcu();
 
 	return 0;
 }
@@ -1393,6 +1405,7 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
 	INIT_LIST_HEAD(&cgrp->allcg_node);
 	INIT_LIST_HEAD(&cgrp->release_list);
 	INIT_LIST_HEAD(&cgrp->pidlists);
+	INIT_WORK(&cgrp->free_work, cgroup_free_fn);
 	mutex_init(&cgrp->pidlist_mutex);
 	INIT_LIST_HEAD(&cgrp->event_list);
 	spin_lock_init(&cgrp->event_list_lock);
@@ -1597,6 +1610,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
 		struct cgroupfs_root *existing_root;
 		const struct cred *cred;
 		int i;
+		struct css_set *cg;
 
 		BUG_ON(sb->s_root != NULL);
 
@@ -1650,14 +1664,8 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
 		/* Link the top cgroup in this hierarchy into all
 		 * the css_set objects */
 		write_lock(&css_set_lock);
-		for (i = 0; i < CSS_SET_TABLE_SIZE; i++) {
-			struct hlist_head *hhead = &css_set_table[i];
-			struct hlist_node *node;
-			struct css_set *cg;
-
-			hlist_for_each_entry(cg, node, hhead, hlist)
-				link_css_set(&tmp_cg_links, cg, root_cgrp);
-		}
+		hash_for_each(css_set_table, i, cg, hlist)
+			link_css_set(&tmp_cg_links, cg, root_cgrp);
 		write_unlock(&css_set_lock);
 
 		free_cg_links(&tmp_cg_links);
@@ -1773,7 +1781,7 @@ int cgroup_path(const struct cgroup *cgrp, char *buf, int buflen)
 	rcu_lockdep_assert(rcu_read_lock_held() || cgroup_lock_is_held(),
 			   "cgroup_path() called without proper locking");
 
-	if (!dentry || cgrp == dummytop) {
+	if (cgrp == dummytop) {
 		/*
 		 * Inactive subsystems have no dentry for their root
 		 * cgroup
@@ -1982,7 +1990,6 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
 			ss->attach(cgrp, &tset);
 	}
 
-	synchronize_rcu();
 out:
 	if (retval) {
 		for_each_subsys(root, ss) {
@@ -2151,7 +2158,6 @@ static int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
 	/*
 	 * step 5: success! and cleanup
 	 */
-	synchronize_rcu();
 	retval = 0;
 out_put_css_set_refs:
 	if (retval) {
@@ -2637,7 +2643,7 @@ static struct dentry *cgroup_lookup(struct inode *dir, struct dentry *dentry, un
  */
 static inline struct cftype *__file_cft(struct file *file)
 {
-	if (file->f_dentry->d_inode->i_fop != &cgroup_file_operations)
+	if (file_inode(file)->i_fop != &cgroup_file_operations)
 		return ERR_PTR(-EINVAL);
 	return __d_cft(file->f_dentry);
 }
@@ -2769,14 +2775,14 @@ static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys,
 		if ((cft->flags & CFTYPE_ONLY_ON_ROOT) && cgrp->parent)
 			continue;
 
-		if (is_add)
+		if (is_add) {
 			err = cgroup_add_file(cgrp, subsys, cft);
-		else
-			err = cgroup_rm_file(cgrp, cft);
-		if (err) {
-			pr_warning("cgroup_addrm_files: failed to %s %s, err=%d\n",
-				   is_add ? "add" : "remove", cft->name, err);
+			if (err)
+				pr_warn("cgroup_addrm_files: failed to add %s, err=%d\n",
+					cft->name, err);
 			ret = err;
+		} else {
+			cgroup_rm_file(cgrp, cft);
 		}
 	}
 	return ret;
@@ -3017,6 +3023,32 @@ struct cgroup *cgroup_next_descendant_pre(struct cgroup *pos,
 }
 EXPORT_SYMBOL_GPL(cgroup_next_descendant_pre);
 
+/**
+ * cgroup_rightmost_descendant - return the rightmost descendant of a cgroup
+ * @pos: cgroup of interest
+ *
+ * Return the rightmost descendant of @pos.  If there's no descendant,
+ * @pos is returned.  This can be used during pre-order traversal to skip
+ * subtree of @pos.
+ */
+struct cgroup *cgroup_rightmost_descendant(struct cgroup *pos)
+{
+	struct cgroup *last, *tmp;
+
+	WARN_ON_ONCE(!rcu_read_lock_held());
+
+	do {
+		last = pos;
+		/* ->prev isn't RCU safe, walk ->next till the end */
+		pos = NULL;
+		list_for_each_entry_rcu(tmp, &last->children, sibling)
+			pos = tmp;
+	} while (pos);
+
+	return last;
+}
+EXPORT_SYMBOL_GPL(cgroup_rightmost_descendant);
+
 static struct cgroup *cgroup_leftmost_descendant(struct cgroup *pos)
 {
 	struct cgroup *last;
@@ -3752,8 +3784,13 @@ static void cgroup_event_remove(struct work_struct *work)
 			remove);
 	struct cgroup *cgrp = event->cgrp;
 
+	remove_wait_queue(event->wqh, &event->wait);
+
 	event->cft->unregister_event(cgrp, event->cft, event->eventfd);
 
+	/* Notify userspace the event is going away. */
+	eventfd_signal(event->eventfd, 1);
+
 	eventfd_ctx_put(event->eventfd);
 	kfree(event);
 	dput(cgrp->dentry);
@@ -3773,15 +3810,25 @@ static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
 	unsigned long flags = (unsigned long)key;
 
 	if (flags & POLLHUP) {
-		__remove_wait_queue(event->wqh, &event->wait);
-		spin_lock(&cgrp->event_list_lock);
-		list_del_init(&event->list);
-		spin_unlock(&cgrp->event_list_lock);
 		/*
-		 * We are in atomic context, but cgroup_event_remove() may
-		 * sleep, so we have to call it in workqueue.
+		 * If the event has been detached at cgroup removal, we
+		 * can simply return knowing the other side will cleanup
+		 * for us.
+		 *
+		 * We can't race against event freeing since the other
+		 * side will require wqh->lock via remove_wait_queue(),
+		 * which we hold.
 		 */
-		schedule_work(&event->remove);
+		spin_lock(&cgrp->event_list_lock);
+		if (!list_empty(&event->list)) {
+			list_del_init(&event->list);
+			/*
+			 * We are in atomic context, but cgroup_event_remove()
+			 * may sleep, so we have to call it in workqueue.
+			 */
+			schedule_work(&event->remove);
+		}
+		spin_unlock(&cgrp->event_list_lock);
 	}
 
 	return 0;
@@ -3807,6 +3854,7 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
 				      const char *buffer)
 {
 	struct cgroup_event *event = NULL;
+	struct cgroup *cgrp_cfile;
 	unsigned int efd, cfd;
 	struct file *efile = NULL;
 	struct file *cfile = NULL;
@@ -3852,7 +3900,7 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
 
 	/* the process need read permission on control file */
 	/* AV: shouldn't we check that it's been opened for read instead? */
-	ret = inode_permission(cfile->f_path.dentry->d_inode, MAY_READ);
+	ret = inode_permission(file_inode(cfile), MAY_READ);
 	if (ret < 0)
 		goto fail;
 
@@ -3862,6 +3910,16 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
 		goto fail;
 	}
 
+	/*
+	 * The file to be monitored must be in the same cgroup as
+	 * cgroup.event_control is.
+	 */
+	cgrp_cfile = __d_cgrp(cfile->f_dentry->d_parent);
+	if (cgrp_cfile != cgrp) {
+		ret = -EINVAL;
+		goto fail;
+	}
+
 	if (!event->cft->register_event || !event->cft->unregister_event) {
 		ret = -EINVAL;
 		goto fail;
@@ -4135,6 +4193,9 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
 
 	init_cgroup_housekeeping(cgrp);
 
+	dentry->d_fsdata = cgrp;
+	cgrp->dentry = dentry;
+
 	cgrp->parent = parent;
 	cgrp->root = parent->root;
 	cgrp->top_cgroup = parent->top_cgroup;
@@ -4172,8 +4233,6 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
 	lockdep_assert_held(&dentry->d_inode->i_mutex);
 
 	/* allocation complete, commit to creation */
-	dentry->d_fsdata = cgrp;
-	cgrp->dentry = dentry;
 	list_add_tail(&cgrp->allcg_node, &root->allcg_list);
 	list_add_tail_rcu(&cgrp->sibling, &cgrp->parent->children);
 	root->number_of_cgroups++;
@@ -4340,20 +4399,14 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
 	/*
 	 * Unregister events and notify userspace.
 	 * Notify userspace about cgroup removing only after rmdir of cgroup
-	 * directory to avoid race between userspace and kernelspace. Use
-	 * a temporary list to avoid a deadlock with cgroup_event_wake(). Since
-	 * cgroup_event_wake() is called with the wait queue head locked,
-	 * remove_wait_queue() cannot be called while holding event_list_lock.
+	 * directory to avoid race between userspace and kernelspace.
 	 */
 	spin_lock(&cgrp->event_list_lock);
-	list_splice_init(&cgrp->event_list, &tmp_list);
-	spin_unlock(&cgrp->event_list_lock);
-	list_for_each_entry_safe(event, tmp, &tmp_list, list) {
+	list_for_each_entry_safe(event, tmp, &cgrp->event_list, list) {
 		list_del_init(&event->list);
-		remove_wait_queue(event->wqh, &event->wait);
-		eventfd_signal(event->eventfd, 1);
 		schedule_work(&event->remove);
 	}
+	spin_unlock(&cgrp->event_list_lock);
 
 	return 0;
 }
@@ -4438,6 +4491,9 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
 {
 	struct cgroup_subsys_state *css;
 	int i, ret;
+	struct hlist_node *tmp;
+	struct css_set *cg;
+	unsigned long key;
 
 	/* check name and function validity */
 	if (ss->name == NULL || strlen(ss->name) > MAX_CGROUP_TYPE_NAMELEN ||
@@ -4503,23 +4559,17 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
 	 * this is all done under the css_set_lock.
 	 */
 	write_lock(&css_set_lock);
-	for (i = 0; i < CSS_SET_TABLE_SIZE; i++) {
-		struct css_set *cg;
-		struct hlist_node *node, *tmp;
-		struct hlist_head *bucket = &css_set_table[i], *new_bucket;
-
-		hlist_for_each_entry_safe(cg, node, tmp, bucket, hlist) {
-			/* skip entries that we already rehashed */
-			if (cg->subsys[ss->subsys_id])
-				continue;
-			/* remove existing entry */
-			hlist_del(&cg->hlist);
-			/* set new value */
-			cg->subsys[ss->subsys_id] = css;
-			/* recompute hash and restore entry */
-			new_bucket = css_set_hash(cg->subsys);
-			hlist_add_head(&cg->hlist, new_bucket);
-		}
+	hash_for_each_safe(css_set_table, i, tmp, cg, hlist) {
+		/* skip entries that we already rehashed */
+		if (cg->subsys[ss->subsys_id])
+			continue;
+		/* remove existing entry */
+		hash_del(&cg->hlist);
+		/* set new value */
+		cg->subsys[ss->subsys_id] = css;
+		/* recompute hash and restore entry */
+		key = css_set_hash(cg->subsys);
+		hash_add(css_set_table, &cg->hlist, key);
 	}
 	write_unlock(&css_set_lock);
 
@@ -4551,7 +4601,6 @@ EXPORT_SYMBOL_GPL(cgroup_load_subsys);
 void cgroup_unload_subsys(struct cgroup_subsys *ss)
 {
 	struct cg_cgroup_link *link;
-	struct hlist_head *hhead;
 
 	BUG_ON(ss->module == NULL);
 
@@ -4567,10 +4616,8 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
 	offline_css(ss, dummytop);
 	ss->active = 0;
 
-	if (ss->use_id) {
-		idr_remove_all(&ss->idr);
+	if (ss->use_id)
 		idr_destroy(&ss->idr);
-	}
 
 	/* deassign the subsys_id */
 	subsys[ss->subsys_id] = NULL;
@@ -4585,11 +4632,12 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
 	write_lock(&css_set_lock);
 	list_for_each_entry(link, &dummytop->css_sets, cgrp_link_list) {
 		struct css_set *cg = link->cg;
+		unsigned long key;
 
-		hlist_del(&cg->hlist);
+		hash_del(&cg->hlist);
 		cg->subsys[ss->subsys_id] = NULL;
-		hhead = css_set_hash(cg->subsys);
-		hlist_add_head(&cg->hlist, hhead);
+		key = css_set_hash(cg->subsys);
+		hash_add(css_set_table, &cg->hlist, key);
 	}
 	write_unlock(&css_set_lock);
 
@@ -4631,9 +4679,6 @@ int __init cgroup_init_early(void)
 	list_add(&init_css_set_link.cg_link_list,
 		 &init_css_set.cg_links);
 
-	for (i = 0; i < CSS_SET_TABLE_SIZE; i++)
-		INIT_HLIST_HEAD(&css_set_table[i]);
-
 	for (i = 0; i < CGROUP_SUBSYS_COUNT; i++) {
 		struct cgroup_subsys *ss = subsys[i];
 
@@ -4667,7 +4712,7 @@ int __init cgroup_init(void)
 {
 	int err;
 	int i;
-	struct hlist_head *hhead;
+	unsigned long key;
 
 	err = bdi_init(&cgroup_backing_dev_info);
 	if (err)
@@ -4686,8 +4731,8 @@ int __init cgroup_init(void)
 	}
 
 	/* Add init_css_set to the hash table */
-	hhead = css_set_hash(init_css_set.subsys);
-	hlist_add_head(&init_css_set.hlist, hhead);
+	key = css_set_hash(init_css_set.subsys);
+	hash_add(css_set_table, &init_css_set.hlist, key);
 	BUG_ON(!init_root_id(&rootnode));
 
 	cgroup_kobj = kobject_create_and_add("cgroup", fs_kobj);
@@ -4982,8 +5027,7 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks)
 	}
 	task_unlock(tsk);
 
-	if (cg)
-		put_css_set_taskexit(cg);
+	put_css_set_taskexit(cg);
 }
 
 /**
@@ -5274,7 +5318,7 @@ EXPORT_SYMBOL_GPL(free_css_id);
 static struct css_id *get_new_cssid(struct cgroup_subsys *ss, int depth)
 {
 	struct css_id *newid;
-	int myid, error, size;
+	int ret, size;
 
 	BUG_ON(!ss->use_id);
 
@@ -5282,35 +5326,24 @@ static struct css_id *get_new_cssid(struct cgroup_subsys *ss, int depth)
 	newid = kzalloc(size, GFP_KERNEL);
 	if (!newid)
 		return ERR_PTR(-ENOMEM);
-	/* get id */
-	if (unlikely(!idr_pre_get(&ss->idr, GFP_KERNEL))) {
-		error = -ENOMEM;
-		goto err_out;
-	}
+
+	idr_preload(GFP_KERNEL);
 	spin_lock(&ss->id_lock);
 	/* Don't use 0. allocates an ID of 1-65535 */
-	error = idr_get_new_above(&ss->idr, newid, 1, &myid);
+	ret = idr_alloc(&ss->idr, newid, 1, CSS_ID_MAX + 1, GFP_NOWAIT);
 	spin_unlock(&ss->id_lock);
+	idr_preload_end();
 
 	/* Returns error when there are no free spaces for new ID.*/
-	if (error) {
-		error = -ENOSPC;
+	if (ret < 0)
 		goto err_out;
-	}
-	if (myid > CSS_ID_MAX)
-		goto remove_idr;
 
-	newid->id = myid;
+	newid->id = ret;
 	newid->depth = depth;
 	return newid;
-remove_idr:
-	error = -ENOSPC;
-	spin_lock(&ss->id_lock);
-	idr_remove(&ss->idr, myid);
-	spin_unlock(&ss->id_lock);
 err_out:
 	kfree(newid);
-	return ERR_PTR(error);
+	return ERR_PTR(ret);
 
 }
 
@@ -5441,7 +5474,7 @@ struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id)
 	struct inode *inode;
 	struct cgroup_subsys_state *css;
 
-	inode = f->f_dentry->d_inode;
+	inode = file_inode(f);
 	/* check in cgroup filesystem dir */
 	if (inode->i_op != &cgroup_dir_inode_operations)
 		return ERR_PTR(-EBADF);
diff --git a/kernel/compat.c b/kernel/compat.c
index 36700e9e2be9..19971d8c7299 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -290,8 +290,8 @@ static inline long put_compat_itimerval(struct compat_itimerval __user *o,
 		 __put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
 }
 
-asmlinkage long compat_sys_getitimer(int which,
-		struct compat_itimerval __user *it)
+COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
+		struct compat_itimerval __user *, it)
 {
 	struct itimerval kit;
 	int error;
@@ -302,9 +302,9 @@ asmlinkage long compat_sys_getitimer(int which,
 	return error;
 }
 
-asmlinkage long compat_sys_setitimer(int which,
-		struct compat_itimerval __user *in,
-		struct compat_itimerval __user *out)
+COMPAT_SYSCALL_DEFINE3(setitimer, int, which,
+		struct compat_itimerval __user *, in,
+		struct compat_itimerval __user *, out)
 {
 	struct itimerval kin, kout;
 	int error;
@@ -381,9 +381,9 @@ static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
 	memcpy(blocked->sig, &set, sizeof(set));
 }
 
-asmlinkage long compat_sys_sigprocmask(int how,
-				       compat_old_sigset_t __user *nset,
-				       compat_old_sigset_t __user *oset)
+COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
+		       compat_old_sigset_t __user *, nset,
+		       compat_old_sigset_t __user *, oset)
 {
 	old_sigset_t old_set, new_set;
 	sigset_t new_blocked;
@@ -593,7 +593,7 @@ COMPAT_SYSCALL_DEFINE5(waitid,
 		else
 			ret = put_compat_rusage(&ru, uru);
 		if (ret)
-			return ret;
+			return -EFAULT;
 	}
 
 	BUG_ON(info.si_code & __SI_MASK);
@@ -971,7 +971,7 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
 }
 
 void
-sigset_from_compat (sigset_t *set, compat_sigset_t *compat)
+sigset_from_compat(sigset_t *set, const compat_sigset_t *compat)
 {
 	switch (_NSIG_WORDS) {
 	case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
@@ -982,10 +982,20 @@ sigset_from_compat (sigset_t *set, compat_sigset_t *compat)
 }
 EXPORT_SYMBOL_GPL(sigset_from_compat);
 
-asmlinkage long
-compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese,
-		struct compat_siginfo __user *uinfo,
-		struct compat_timespec __user *uts, compat_size_t sigsetsize)
+void
+sigset_to_compat(compat_sigset_t *compat, const sigset_t *set)
+{
+	switch (_NSIG_WORDS) {
+	case 4: compat->sig[7] = (set->sig[3] >> 32); compat->sig[6] = set->sig[3];
+	case 3: compat->sig[5] = (set->sig[2] >> 32); compat->sig[4] = set->sig[2];
+	case 2: compat->sig[3] = (set->sig[1] >> 32); compat->sig[2] = set->sig[1];
+	case 1: compat->sig[1] = (set->sig[0] >> 32); compat->sig[0] = set->sig[0];
+	}
+}
+
+COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
+		struct compat_siginfo __user *, uinfo,
+		struct compat_timespec __user *, uts, compat_size_t, sigsetsize)
 {
 	compat_sigset_t s32;
 	sigset_t s;
@@ -1013,18 +1023,6 @@ compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese,
 	}
 
 	return ret;
-
-}
-
-asmlinkage long
-compat_sys_rt_tgsigqueueinfo(compat_pid_t tgid, compat_pid_t pid, int sig,
-			     struct compat_siginfo __user *uinfo)
-{
-	siginfo_t info;
-
-	if (copy_siginfo_from_user32(&info, uinfo))
-		return -EFAULT;
-	return do_rt_tgsigqueueinfo(tgid, pid, sig, &info);
 }
 
 #ifdef __ARCH_WANT_COMPAT_SYS_TIME
@@ -1067,23 +1065,6 @@ asmlinkage long compat_sys_stime(compat_time_t __user *tptr)
 
 #endif /* __ARCH_WANT_COMPAT_SYS_TIME */
 
-#ifdef __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND
-asmlinkage long compat_sys_rt_sigsuspend(compat_sigset_t __user *unewset, compat_size_t sigsetsize)
-{
-	sigset_t newset;
-	compat_sigset_t newset32;
-
-	/* XXX: Don't preclude handling different sized sigset_t's.  */
-	if (sigsetsize != sizeof(sigset_t))
-		return -EINVAL;
-
-	if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t)))
-		return -EFAULT;
-	sigset_from_compat(&newset, &newset32);
-	return sigsuspend(&newset);
-}
-#endif /* __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND */
-
 asmlinkage long compat_sys_adjtimex(struct compat_timex __user *utp)
 {
 	struct timex txc;
@@ -1222,9 +1203,9 @@ compat_sys_sysinfo(struct compat_sysinfo __user *info)
 	return 0;
 }
 
-#ifdef __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL
-asmlinkage long compat_sys_sched_rr_get_interval(compat_pid_t pid,
-						 struct compat_timespec __user *interval)
+COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
+		       compat_pid_t, pid,
+		       struct compat_timespec __user *, interval)
 {
 	struct timespec t;
 	int ret;
@@ -1237,7 +1218,6 @@ asmlinkage long compat_sys_sched_rr_get_interval(compat_pid_t pid,
 		return -EFAULT;
 	return ret;
 }
-#endif /* __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL */
 
 /*
  * Allocate user-space memory for the duration of a single system call,
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index e0e07fd55508..65349f07b878 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -1,29 +1,41 @@
+/*
+ * Context tracking: Probe on high level context boundaries such as kernel
+ * and userspace. This includes syscalls and exceptions entry/exit.
+ *
+ * This is used by RCU to remove its dependency on the timer tick while a CPU
+ * runs in userspace.
+ *
+ *  Started by Frederic Weisbecker:
+ *
+ * Copyright (C) 2012 Red Hat, Inc., Frederic Weisbecker <fweisbec@redhat.com>
+ *
+ * Many thanks to Gilad Ben-Yossef, Paul McKenney, Ingo Molnar, Andrew Morton,
+ * Steven Rostedt, Peter Zijlstra for suggestions and improvements.
+ *
+ */
+
 #include <linux/context_tracking.h>
+#include <linux/kvm_host.h>
 #include <linux/rcupdate.h>
 #include <linux/sched.h>
-#include <linux/percpu.h>
 #include <linux/hardirq.h>
+#include <linux/export.h>
 
-struct context_tracking {
-	/*
-	 * When active is false, hooks are not set to
-	 * minimize overhead: TIF flags are cleared
-	 * and calls to user_enter/exit are ignored. This
-	 * may be further optimized using static keys.
-	 */
-	bool active;
-	enum {
-		IN_KERNEL = 0,
-		IN_USER,
-	} state;
-};
-
-static DEFINE_PER_CPU(struct context_tracking, context_tracking) = {
+DEFINE_PER_CPU(struct context_tracking, context_tracking) = {
 #ifdef CONFIG_CONTEXT_TRACKING_FORCE
 	.active = true,
 #endif
 };
 
+/**
+ * user_enter - Inform the context tracking that the CPU is going to
+ *              enter userspace mode.
+ *
+ * This function must be called right before we switch from the kernel
+ * to userspace, when it's guaranteed the remaining kernel instructions
+ * to execute won't use any RCU read side critical section because this
+ * function sets RCU in extended quiescent state.
+ */
 void user_enter(void)
 {
 	unsigned long flags;
@@ -39,40 +51,90 @@ void user_enter(void)
 	if (in_interrupt())
 		return;
 
+	/* Kernel threads aren't supposed to go to userspace */
 	WARN_ON_ONCE(!current->mm);
 
 	local_irq_save(flags);
 	if (__this_cpu_read(context_tracking.active) &&
 	    __this_cpu_read(context_tracking.state) != IN_USER) {
-		__this_cpu_write(context_tracking.state, IN_USER);
+		/*
+		 * At this stage, only low level arch entry code remains and
+		 * then we'll run in userspace. We can assume there won't be
+		 * any RCU read-side critical section until the next call to
+		 * user_exit() or rcu_irq_enter(). Let's remove RCU's dependency
+		 * on the tick.
+		 */
+		vtime_user_enter(current);
 		rcu_user_enter();
+		__this_cpu_write(context_tracking.state, IN_USER);
 	}
 	local_irq_restore(flags);
 }
 
+
+/**
+ * user_exit - Inform the context tracking that the CPU is
+ *             exiting userspace mode and entering the kernel.
+ *
+ * This function must be called after we entered the kernel from userspace
+ * before any use of RCU read side critical section. This potentially include
+ * any high level kernel code like syscalls, exceptions, signal handling, etc...
+ *
+ * This call supports re-entrancy. This way it can be called from any exception
+ * handler without needing to know if we came from userspace or not.
+ */
 void user_exit(void)
 {
 	unsigned long flags;
 
-	/*
-	 * Some contexts may involve an exception occuring in an irq,
-	 * leading to that nesting:
-	 * rcu_irq_enter() rcu_user_exit() rcu_user_exit() rcu_irq_exit()
-	 * This would mess up the dyntick_nesting count though. And rcu_irq_*()
-	 * helpers are enough to protect RCU uses inside the exception. So
-	 * just return immediately if we detect we are in an IRQ.
-	 */
 	if (in_interrupt())
 		return;
 
 	local_irq_save(flags);
 	if (__this_cpu_read(context_tracking.state) == IN_USER) {
-		__this_cpu_write(context_tracking.state, IN_KERNEL);
+		/*
+		 * We are going to run code that may use RCU. Inform
+		 * RCU core about that (ie: we may need the tick again).
+		 */
 		rcu_user_exit();
+		vtime_user_exit(current);
+		__this_cpu_write(context_tracking.state, IN_KERNEL);
 	}
 	local_irq_restore(flags);
 }
 
+void guest_enter(void)
+{
+	if (vtime_accounting_enabled())
+		vtime_guest_enter(current);
+	else
+		__guest_enter();
+}
+EXPORT_SYMBOL_GPL(guest_enter);
+
+void guest_exit(void)
+{
+	if (vtime_accounting_enabled())
+		vtime_guest_exit(current);
+	else
+		__guest_exit();
+}
+EXPORT_SYMBOL_GPL(guest_exit);
+
+
+/**
+ * context_tracking_task_switch - context switch the syscall callbacks
+ * @prev: the task that is being switched out
+ * @next: the task that is being switched in
+ *
+ * The context tracking uses the syscall slow path to implement its user-kernel
+ * boundaries probes on syscalls. This way it doesn't impact the syscall fast
+ * path on CPUs that don't do context tracking.
+ *
+ * But we need to clear the flag on the previous task because it may later
+ * migrate to some CPU that doesn't do the context tracking. As such the TIF
+ * flag may not be desired there.
+ */
 void context_tracking_task_switch(struct task_struct *prev,
 			     struct task_struct *next)
 {
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 3046a503242c..b5e4ab2d427e 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -224,11 +224,13 @@ void clear_tasks_mm_cpumask(int cpu)
 static inline void check_for_tasks(int cpu)
 {
 	struct task_struct *p;
+	cputime_t utime, stime;
 
 	write_lock_irq(&tasklist_lock);
 	for_each_process(p) {
+		task_cputime(p, &utime, &stime);
 		if (task_cpu(p) == cpu && p->state == TASK_RUNNING &&
-		    (p->utime || p->stime))
+		    (utime || stime))
 			printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d "
 				"(state = %ld, flags = %x)\n",
 				p->comm, task_pid_nr(p), cpu,
@@ -254,6 +256,8 @@ static int __ref take_cpu_down(void *_param)
 		return err;
 
 	cpu_notify(CPU_DYING | param->mod, param->hcpu);
+	/* Park the stopper thread */
+	kthread_park(current);
 	return 0;
 }
 
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 7bb63eea6eb8..4f9dfe43ecbd 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -61,14 +61,6 @@
 #include <linux/cgroup.h>
 
 /*
- * Workqueue for cpuset related tasks.
- *
- * Using kevent workqueue may cause deadlock when memory_migrate
- * is set. So we create a separate workqueue thread for cpuset.
- */
-static struct workqueue_struct *cpuset_wq;
-
-/*
  * Tracks how many cpusets are currently defined in system.
  * When there is only one cpuset (the root cpuset) we can
  * short circuit some hooks.
@@ -95,18 +87,21 @@ struct cpuset {
 	cpumask_var_t cpus_allowed;	/* CPUs allowed to tasks in cpuset */
 	nodemask_t mems_allowed;	/* Memory Nodes allowed to tasks */
 
-	struct cpuset *parent;		/* my parent */
-
 	struct fmeter fmeter;		/* memory_pressure filter */
 
+	/*
+	 * Tasks are being attached to this cpuset.  Used to prevent
+	 * zeroing cpus/mems_allowed between ->can_attach() and ->attach().
+	 */
+	int attach_in_progress;
+
 	/* partition number for rebuild_sched_domains() */
 	int pn;
 
 	/* for custom sched domain */
 	int relax_domain_level;
 
-	/* used for walking a cpuset hierarchy */
-	struct list_head stack_list;
+	struct work_struct hotplug_work;
 };
 
 /* Retrieve the cpuset for a cgroup */
@@ -123,6 +118,15 @@ static inline struct cpuset *task_cs(struct task_struct *task)
 			    struct cpuset, css);
 }
 
+static inline struct cpuset *parent_cs(const struct cpuset *cs)
+{
+	struct cgroup *pcgrp = cs->css.cgroup->parent;
+
+	if (pcgrp)
+		return cgroup_cs(pcgrp);
+	return NULL;
+}
+
 #ifdef CONFIG_NUMA
 static inline bool task_has_mempolicy(struct task_struct *task)
 {
@@ -138,6 +142,7 @@ static inline bool task_has_mempolicy(struct task_struct *task)
 
 /* bits in struct cpuset flags field */
 typedef enum {
+	CS_ONLINE,
 	CS_CPU_EXCLUSIVE,
 	CS_MEM_EXCLUSIVE,
 	CS_MEM_HARDWALL,
@@ -147,13 +152,12 @@ typedef enum {
 	CS_SPREAD_SLAB,
 } cpuset_flagbits_t;
 
-/* the type of hotplug event */
-enum hotplug_event {
-	CPUSET_CPU_OFFLINE,
-	CPUSET_MEM_OFFLINE,
-};
-
 /* convenient tests for these bits */
+static inline bool is_cpuset_online(const struct cpuset *cs)
+{
+	return test_bit(CS_ONLINE, &cs->flags);
+}
+
 static inline int is_cpu_exclusive(const struct cpuset *cs)
 {
 	return test_bit(CS_CPU_EXCLUSIVE, &cs->flags);
@@ -190,27 +194,52 @@ static inline int is_spread_slab(const struct cpuset *cs)
 }
 
 static struct cpuset top_cpuset = {
-	.flags = ((1 << CS_CPU_EXCLUSIVE) | (1 << CS_MEM_EXCLUSIVE)),
+	.flags = ((1 << CS_ONLINE) | (1 << CS_CPU_EXCLUSIVE) |
+		  (1 << CS_MEM_EXCLUSIVE)),
 };
 
+/**
+ * cpuset_for_each_child - traverse online children of a cpuset
+ * @child_cs: loop cursor pointing to the current child
+ * @pos_cgrp: used for iteration
+ * @parent_cs: target cpuset to walk children of
+ *
+ * Walk @child_cs through the online children of @parent_cs.  Must be used
+ * with RCU read locked.
+ */
+#define cpuset_for_each_child(child_cs, pos_cgrp, parent_cs)		\
+	cgroup_for_each_child((pos_cgrp), (parent_cs)->css.cgroup)	\
+		if (is_cpuset_online(((child_cs) = cgroup_cs((pos_cgrp)))))
+
+/**
+ * cpuset_for_each_descendant_pre - pre-order walk of a cpuset's descendants
+ * @des_cs: loop cursor pointing to the current descendant
+ * @pos_cgrp: used for iteration
+ * @root_cs: target cpuset to walk ancestor of
+ *
+ * Walk @des_cs through the online descendants of @root_cs.  Must be used
+ * with RCU read locked.  The caller may modify @pos_cgrp by calling
+ * cgroup_rightmost_descendant() to skip subtree.
+ */
+#define cpuset_for_each_descendant_pre(des_cs, pos_cgrp, root_cs)	\
+	cgroup_for_each_descendant_pre((pos_cgrp), (root_cs)->css.cgroup) \
+		if (is_cpuset_online(((des_cs) = cgroup_cs((pos_cgrp)))))
+
 /*
- * There are two global mutexes guarding cpuset structures.  The first
- * is the main control groups cgroup_mutex, accessed via
- * cgroup_lock()/cgroup_unlock().  The second is the cpuset-specific
- * callback_mutex, below. They can nest.  It is ok to first take
- * cgroup_mutex, then nest callback_mutex.  We also require taking
- * task_lock() when dereferencing a task's cpuset pointer.  See "The
- * task_lock() exception", at the end of this comment.
- *
- * A task must hold both mutexes to modify cpusets.  If a task
- * holds cgroup_mutex, then it blocks others wanting that mutex,
- * ensuring that it is the only task able to also acquire callback_mutex
- * and be able to modify cpusets.  It can perform various checks on
- * the cpuset structure first, knowing nothing will change.  It can
- * also allocate memory while just holding cgroup_mutex.  While it is
- * performing these checks, various callback routines can briefly
- * acquire callback_mutex to query cpusets.  Once it is ready to make
- * the changes, it takes callback_mutex, blocking everyone else.
+ * There are two global mutexes guarding cpuset structures - cpuset_mutex
+ * and callback_mutex.  The latter may nest inside the former.  We also
+ * require taking task_lock() when dereferencing a task's cpuset pointer.
+ * See "The task_lock() exception", at the end of this comment.
+ *
+ * A task must hold both mutexes to modify cpusets.  If a task holds
+ * cpuset_mutex, then it blocks others wanting that mutex, ensuring that it
+ * is the only task able to also acquire callback_mutex and be able to
+ * modify cpusets.  It can perform various checks on the cpuset structure
+ * first, knowing nothing will change.  It can also allocate memory while
+ * just holding cpuset_mutex.  While it is performing these checks, various
+ * callback routines can briefly acquire callback_mutex to query cpusets.
+ * Once it is ready to make the changes, it takes callback_mutex, blocking
+ * everyone else.
  *
  * Calls to the kernel memory allocator can not be made while holding
  * callback_mutex, as that would risk double tripping on callback_mutex
@@ -232,6 +261,7 @@ static struct cpuset top_cpuset = {
  * guidelines for accessing subsystem state in kernel/cgroup.c
  */
 
+static DEFINE_MUTEX(cpuset_mutex);
 static DEFINE_MUTEX(callback_mutex);
 
 /*
@@ -246,6 +276,17 @@ static char cpuset_nodelist[CPUSET_NODELIST_LEN];
 static DEFINE_SPINLOCK(cpuset_buffer_lock);
 
 /*
+ * CPU / memory hotplug is handled asynchronously.
+ */
+static struct workqueue_struct *cpuset_propagate_hotplug_wq;
+
+static void cpuset_hotplug_workfn(struct work_struct *work);
+static void cpuset_propagate_hotplug_workfn(struct work_struct *work);
+static void schedule_cpuset_propagate_hotplug(struct cpuset *cs);
+
+static DECLARE_WORK(cpuset_hotplug_work, cpuset_hotplug_workfn);
+
+/*
  * This is ugly, but preserves the userspace API for existing cpuset
  * users. If someone tries to mount the "cpuset" filesystem, we
  * silently switch it to mount "cgroup" instead
@@ -289,7 +330,7 @@ static void guarantee_online_cpus(const struct cpuset *cs,
 				  struct cpumask *pmask)
 {
 	while (cs && !cpumask_intersects(cs->cpus_allowed, cpu_online_mask))
-		cs = cs->parent;
+		cs = parent_cs(cs);
 	if (cs)
 		cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask);
 	else
@@ -314,7 +355,7 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
 {
 	while (cs && !nodes_intersects(cs->mems_allowed,
 					node_states[N_MEMORY]))
-		cs = cs->parent;
+		cs = parent_cs(cs);
 	if (cs)
 		nodes_and(*pmask, cs->mems_allowed,
 					node_states[N_MEMORY]);
@@ -326,7 +367,7 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
 /*
  * update task's spread flag if cpuset's page/slab spread flag is set
  *
- * Called with callback_mutex/cgroup_mutex held
+ * Called with callback_mutex/cpuset_mutex held
  */
 static void cpuset_update_task_spread_flag(struct cpuset *cs,
 					struct task_struct *tsk)
@@ -346,7 +387,7 @@ static void cpuset_update_task_spread_flag(struct cpuset *cs,
  *
  * One cpuset is a subset of another if all its allowed CPUs and
  * Memory Nodes are a subset of the other, and its exclusive flags
- * are only set if the other's are set.  Call holding cgroup_mutex.
+ * are only set if the other's are set.  Call holding cpuset_mutex.
  */
 
 static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
@@ -395,7 +436,7 @@ static void free_trial_cpuset(struct cpuset *trial)
  * If we replaced the flag and mask values of the current cpuset
  * (cur) with those values in the trial cpuset (trial), would
  * our various subset and exclusive rules still be valid?  Presumes
- * cgroup_mutex held.
+ * cpuset_mutex held.
  *
  * 'cur' is the address of an actual, in-use cpuset.  Operations
  * such as list traversal that depend on the actual address of the
@@ -412,48 +453,58 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
 {
 	struct cgroup *cont;
 	struct cpuset *c, *par;
+	int ret;
+
+	rcu_read_lock();
 
 	/* Each of our child cpusets must be a subset of us */
-	list_for_each_entry(cont, &cur->css.cgroup->children, sibling) {
-		if (!is_cpuset_subset(cgroup_cs(cont), trial))
-			return -EBUSY;
-	}
+	ret = -EBUSY;
+	cpuset_for_each_child(c, cont, cur)
+		if (!is_cpuset_subset(c, trial))
+			goto out;
 
 	/* Remaining checks don't apply to root cpuset */
+	ret = 0;
 	if (cur == &top_cpuset)
-		return 0;
+		goto out;
 
-	par = cur->parent;
+	par = parent_cs(cur);
 
 	/* We must be a subset of our parent cpuset */
+	ret = -EACCES;
 	if (!is_cpuset_subset(trial, par))
-		return -EACCES;
+		goto out;
 
 	/*
 	 * If either I or some sibling (!= me) is exclusive, we can't
 	 * overlap
 	 */
-	list_for_each_entry(cont, &par->css.cgroup->children, sibling) {
-		c = cgroup_cs(cont);
+	ret = -EINVAL;
+	cpuset_for_each_child(c, cont, par) {
 		if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) &&
 		    c != cur &&
 		    cpumask_intersects(trial->cpus_allowed, c->cpus_allowed))
-			return -EINVAL;
+			goto out;
 		if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) &&
 		    c != cur &&
 		    nodes_intersects(trial->mems_allowed, c->mems_allowed))
-			return -EINVAL;
+			goto out;
 	}
 
-	/* Cpusets with tasks can't have empty cpus_allowed or mems_allowed */
-	if (cgroup_task_count(cur->css.cgroup)) {
-		if (cpumask_empty(trial->cpus_allowed) ||
-		    nodes_empty(trial->mems_allowed)) {
-			return -ENOSPC;
-		}
-	}
+	/*
+	 * Cpusets with tasks - existing or newly being attached - can't
+	 * have empty cpus_allowed or mems_allowed.
+	 */
+	ret = -ENOSPC;
+	if ((cgroup_task_count(cur->css.cgroup) || cur->attach_in_progress) &&
+	    (cpumask_empty(trial->cpus_allowed) ||
+	     nodes_empty(trial->mems_allowed)))
+		goto out;
 
-	return 0;
+	ret = 0;
+out:
+	rcu_read_unlock();
+	return ret;
 }
 
 #ifdef CONFIG_SMP
@@ -474,31 +525,24 @@ update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c)
 	return;
 }
 
-static void
-update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c)
+static void update_domain_attr_tree(struct sched_domain_attr *dattr,
+				    struct cpuset *root_cs)
 {
-	LIST_HEAD(q);
-
-	list_add(&c->stack_list, &q);
-	while (!list_empty(&q)) {
-		struct cpuset *cp;
-		struct cgroup *cont;
-		struct cpuset *child;
-
-		cp = list_first_entry(&q, struct cpuset, stack_list);
-		list_del(q.next);
+	struct cpuset *cp;
+	struct cgroup *pos_cgrp;
 
-		if (cpumask_empty(cp->cpus_allowed))
+	rcu_read_lock();
+	cpuset_for_each_descendant_pre(cp, pos_cgrp, root_cs) {
+		/* skip the whole subtree if @cp doesn't have any CPU */
+		if (cpumask_empty(cp->cpus_allowed)) {
+			pos_cgrp = cgroup_rightmost_descendant(pos_cgrp);
 			continue;
+		}
 
 		if (is_sched_load_balance(cp))
 			update_domain_attr(dattr, cp);
-
-		list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
-			child = cgroup_cs(cont);
-			list_add_tail(&child->stack_list, &q);
-		}
 	}
+	rcu_read_unlock();
 }
 
 /*
@@ -520,7 +564,7 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c)
  * domains when operating in the severe memory shortage situations
  * that could cause allocation failures below.
  *
- * Must be called with cgroup_lock held.
+ * Must be called with cpuset_mutex held.
  *
  * The three key local variables below are:
  *    q  - a linked-list queue of cpuset pointers, used to implement a
@@ -558,7 +602,6 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c)
 static int generate_sched_domains(cpumask_var_t **domains,
 			struct sched_domain_attr **attributes)
 {
-	LIST_HEAD(q);		/* queue of cpusets to be scanned */
 	struct cpuset *cp;	/* scans q */
 	struct cpuset **csa;	/* array of all cpuset ptrs */
 	int csn;		/* how many cpuset ptrs in csa so far */
@@ -567,6 +610,7 @@ static int generate_sched_domains(cpumask_var_t **domains,
 	struct sched_domain_attr *dattr;  /* attributes for custom domains */
 	int ndoms = 0;		/* number of sched domains in result */
 	int nslot;		/* next empty doms[] struct cpumask slot */
+	struct cgroup *pos_cgrp;
 
 	doms = NULL;
 	dattr = NULL;
@@ -594,33 +638,27 @@ static int generate_sched_domains(cpumask_var_t **domains,
 		goto done;
 	csn = 0;
 
-	list_add(&top_cpuset.stack_list, &q);
-	while (!list_empty(&q)) {
-		struct cgroup *cont;
-		struct cpuset *child;   /* scans child cpusets of cp */
-
-		cp = list_first_entry(&q, struct cpuset, stack_list);
-		list_del(q.next);
-
-		if (cpumask_empty(cp->cpus_allowed))
-			continue;
-
+	rcu_read_lock();
+	cpuset_for_each_descendant_pre(cp, pos_cgrp, &top_cpuset) {
 		/*
-		 * All child cpusets contain a subset of the parent's cpus, so
-		 * just skip them, and then we call update_domain_attr_tree()
-		 * to calc relax_domain_level of the corresponding sched
-		 * domain.
+		 * Continue traversing beyond @cp iff @cp has some CPUs and
+		 * isn't load balancing.  The former is obvious.  The
+		 * latter: All child cpusets contain a subset of the
+		 * parent's cpus, so just skip them, and then we call
+		 * update_domain_attr_tree() to calc relax_domain_level of
+		 * the corresponding sched domain.
 		 */
-		if (is_sched_load_balance(cp)) {
-			csa[csn++] = cp;
+		if (!cpumask_empty(cp->cpus_allowed) &&
+		    !is_sched_load_balance(cp))
 			continue;
-		}
 
-		list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
-			child = cgroup_cs(cont);
-			list_add_tail(&child->stack_list, &q);
-		}
-  	}
+		if (is_sched_load_balance(cp))
+			csa[csn++] = cp;
+
+		/* skip @cp's subtree */
+		pos_cgrp = cgroup_rightmost_descendant(pos_cgrp);
+	}
+	rcu_read_unlock();
 
 	for (i = 0; i < csn; i++)
 		csa[i]->pn = i;
@@ -725,25 +763,25 @@ done:
 /*
  * Rebuild scheduler domains.
  *
- * Call with neither cgroup_mutex held nor within get_online_cpus().
- * Takes both cgroup_mutex and get_online_cpus().
+ * If the flag 'sched_load_balance' of any cpuset with non-empty
+ * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset
+ * which has that flag enabled, or if any cpuset with a non-empty
+ * 'cpus' is removed, then call this routine to rebuild the
+ * scheduler's dynamic sched domains.
  *
- * Cannot be directly called from cpuset code handling changes
- * to the cpuset pseudo-filesystem, because it cannot be called
- * from code that already holds cgroup_mutex.
+ * Call with cpuset_mutex held.  Takes get_online_cpus().
  */
-static void do_rebuild_sched_domains(struct work_struct *unused)
+static void rebuild_sched_domains_locked(void)
 {
 	struct sched_domain_attr *attr;
 	cpumask_var_t *doms;
 	int ndoms;
 
+	lockdep_assert_held(&cpuset_mutex);
 	get_online_cpus();
 
 	/* Generate domain masks and attrs */
-	cgroup_lock();
 	ndoms = generate_sched_domains(&doms, &attr);
-	cgroup_unlock();
 
 	/* Have scheduler rebuild the domains */
 	partition_sched_domains(ndoms, doms, attr);
@@ -751,7 +789,7 @@ static void do_rebuild_sched_domains(struct work_struct *unused)
 	put_online_cpus();
 }
 #else /* !CONFIG_SMP */
-static void do_rebuild_sched_domains(struct work_struct *unused)
+static void rebuild_sched_domains_locked(void)
 {
 }
 
@@ -763,44 +801,11 @@ static int generate_sched_domains(cpumask_var_t **domains,
 }
 #endif /* CONFIG_SMP */
 
-static DECLARE_WORK(rebuild_sched_domains_work, do_rebuild_sched_domains);
-
-/*
- * Rebuild scheduler domains, asynchronously via workqueue.
- *
- * If the flag 'sched_load_balance' of any cpuset with non-empty
- * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset
- * which has that flag enabled, or if any cpuset with a non-empty
- * 'cpus' is removed, then call this routine to rebuild the
- * scheduler's dynamic sched domains.
- *
- * The rebuild_sched_domains() and partition_sched_domains()
- * routines must nest cgroup_lock() inside get_online_cpus(),
- * but such cpuset changes as these must nest that locking the
- * other way, holding cgroup_lock() for much of the code.
- *
- * So in order to avoid an ABBA deadlock, the cpuset code handling
- * these user changes delegates the actual sched domain rebuilding
- * to a separate workqueue thread, which ends up processing the
- * above do_rebuild_sched_domains() function.
- */
-static void async_rebuild_sched_domains(void)
-{
-	queue_work(cpuset_wq, &rebuild_sched_domains_work);
-}
-
-/*
- * Accomplishes the same scheduler domain rebuild as the above
- * async_rebuild_sched_domains(), however it directly calls the
- * rebuild routine synchronously rather than calling it via an
- * asynchronous work thread.
- *
- * This can only be called from code that is not holding
- * cgroup_mutex (not nested in a cgroup_lock() call.)
- */
 void rebuild_sched_domains(void)
 {
-	do_rebuild_sched_domains(NULL);
+	mutex_lock(&cpuset_mutex);
+	rebuild_sched_domains_locked();
+	mutex_unlock(&cpuset_mutex);
 }
 
 /**
@@ -808,7 +813,7 @@ void rebuild_sched_domains(void)
  * @tsk: task to test
  * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner
  *
- * Call with cgroup_mutex held.  May take callback_mutex during call.
+ * Call with cpuset_mutex held.  May take callback_mutex during call.
  * Called for each task in a cgroup by cgroup_scan_tasks().
  * Return nonzero if this tasks's cpus_allowed mask should be changed (in other
  * words, if its mask is not equal to its cpuset's mask).
@@ -829,7 +834,7 @@ static int cpuset_test_cpumask(struct task_struct *tsk,
  * cpus_allowed mask needs to be changed.
  *
  * We don't need to re-check for the cgroup/cpuset membership, since we're
- * holding cgroup_lock() at this point.
+ * holding cpuset_mutex at this point.
  */
 static void cpuset_change_cpumask(struct task_struct *tsk,
 				  struct cgroup_scanner *scan)
@@ -842,7 +847,7 @@ static void cpuset_change_cpumask(struct task_struct *tsk,
  * @cs: the cpuset in which each task's cpus_allowed mask needs to be changed
  * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
  *
- * Called with cgroup_mutex held
+ * Called with cpuset_mutex held
  *
  * The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
  * calling callback functions for each.
@@ -920,7 +925,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
 	heap_free(&heap);
 
 	if (is_load_balanced)
-		async_rebuild_sched_domains();
+		rebuild_sched_domains_locked();
 	return 0;
 }
 
@@ -932,7 +937,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
  *    Temporarilly set tasks mems_allowed to target nodes of migration,
  *    so that the migration code can allocate pages on these nodes.
  *
- *    Call holding cgroup_mutex, so current's cpuset won't change
+ *    Call holding cpuset_mutex, so current's cpuset won't change
  *    during this call, as manage_mutex holds off any cpuset_attach()
  *    calls.  Therefore we don't need to take task_lock around the
  *    call to guarantee_online_mems(), as we know no one is changing
@@ -1007,7 +1012,7 @@ static void cpuset_change_task_nodemask(struct task_struct *tsk,
 /*
  * Update task's mems_allowed and rebind its mempolicy and vmas' mempolicy
  * of it to cpuset's new mems_allowed, and migrate pages to new nodes if
- * memory_migrate flag is set. Called with cgroup_mutex held.
+ * memory_migrate flag is set. Called with cpuset_mutex held.
  */
 static void cpuset_change_nodemask(struct task_struct *p,
 				   struct cgroup_scanner *scan)
@@ -1016,7 +1021,7 @@ static void cpuset_change_nodemask(struct task_struct *p,
 	struct cpuset *cs;
 	int migrate;
 	const nodemask_t *oldmem = scan->data;
-	static nodemask_t newmems;	/* protected by cgroup_mutex */
+	static nodemask_t newmems;	/* protected by cpuset_mutex */
 
 	cs = cgroup_cs(scan->cg);
 	guarantee_online_mems(cs, &newmems);
@@ -1043,7 +1048,7 @@ static void *cpuset_being_rebound;
  * @oldmem: old mems_allowed of cpuset cs
  * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
  *
- * Called with cgroup_mutex held
+ * Called with cpuset_mutex held
  * No return value. It's guaranteed that cgroup_scan_tasks() always returns 0
  * if @heap != NULL.
  */
@@ -1065,7 +1070,7 @@ static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem,
 	 * take while holding tasklist_lock.  Forks can happen - the
 	 * mpol_dup() cpuset_being_rebound check will catch such forks,
 	 * and rebind their vma mempolicies too.  Because we still hold
-	 * the global cgroup_mutex, we know that no other rebind effort
+	 * the global cpuset_mutex, we know that no other rebind effort
 	 * will be contending for the global variable cpuset_being_rebound.
 	 * It's ok if we rebind the same mm twice; mpol_rebind_mm()
 	 * is idempotent.  Also migrate pages in each mm to new nodes.
@@ -1084,7 +1089,7 @@ static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem,
  * mempolicies and if the cpuset is marked 'memory_migrate',
  * migrate the tasks pages to the new memory.
  *
- * Call with cgroup_mutex held.  May take callback_mutex during call.
+ * Call with cpuset_mutex held.  May take callback_mutex during call.
  * Will take tasklist_lock, scan tasklist for tasks in cpuset cs,
  * lock each such tasks mm->mmap_sem, scan its vma's and rebind
  * their mempolicies to the cpusets new mems_allowed.
@@ -1168,7 +1173,7 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val)
 		cs->relax_domain_level = val;
 		if (!cpumask_empty(cs->cpus_allowed) &&
 		    is_sched_load_balance(cs))
-			async_rebuild_sched_domains();
+			rebuild_sched_domains_locked();
 	}
 
 	return 0;
@@ -1182,7 +1187,7 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val)
  * Called by cgroup_scan_tasks() for each task in a cgroup.
  *
  * We don't need to re-check for the cgroup/cpuset membership, since we're
- * holding cgroup_lock() at this point.
+ * holding cpuset_mutex at this point.
  */
 static void cpuset_change_flag(struct task_struct *tsk,
 				struct cgroup_scanner *scan)
@@ -1195,7 +1200,7 @@ static void cpuset_change_flag(struct task_struct *tsk,
  * @cs: the cpuset in which each task's spread flags needs to be changed
  * @heap: if NULL, defer allocating heap memory to cgroup_scan_tasks()
  *
- * Called with cgroup_mutex held
+ * Called with cpuset_mutex held
  *
  * The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
  * calling callback functions for each.
@@ -1220,7 +1225,7 @@ static void update_tasks_flags(struct cpuset *cs, struct ptr_heap *heap)
  * cs:		the cpuset to update
  * turning_on: 	whether the flag is being set or cleared
  *
- * Call with cgroup_mutex held.
+ * Call with cpuset_mutex held.
  */
 
 static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
@@ -1260,7 +1265,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
 	mutex_unlock(&callback_mutex);
 
 	if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
-		async_rebuild_sched_domains();
+		rebuild_sched_domains_locked();
 
 	if (spread_flag_changed)
 		update_tasks_flags(cs, &heap);
@@ -1368,24 +1373,18 @@ static int fmeter_getrate(struct fmeter *fmp)
 	return val;
 }
 
-/*
- * Protected by cgroup_lock. The nodemasks must be stored globally because
- * dynamically allocating them is not allowed in can_attach, and they must
- * persist until attach.
- */
-static cpumask_var_t cpus_attach;
-static nodemask_t cpuset_attach_nodemask_from;
-static nodemask_t cpuset_attach_nodemask_to;
-
-/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
+/* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */
 static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 {
 	struct cpuset *cs = cgroup_cs(cgrp);
 	struct task_struct *task;
 	int ret;
 
+	mutex_lock(&cpuset_mutex);
+
+	ret = -ENOSPC;
 	if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
-		return -ENOSPC;
+		goto out_unlock;
 
 	cgroup_taskset_for_each(task, cgrp, tset) {
 		/*
@@ -1397,25 +1396,45 @@ static int cpuset_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 		 * set_cpus_allowed_ptr() on all attached tasks before
 		 * cpus_allowed may be changed.
 		 */
+		ret = -EINVAL;
 		if (task->flags & PF_THREAD_BOUND)
-			return -EINVAL;
-		if ((ret = security_task_setscheduler(task)))
-			return ret;
+			goto out_unlock;
+		ret = security_task_setscheduler(task);
+		if (ret)
+			goto out_unlock;
 	}
 
-	/* prepare for attach */
-	if (cs == &top_cpuset)
-		cpumask_copy(cpus_attach, cpu_possible_mask);
-	else
-		guarantee_online_cpus(cs, cpus_attach);
-
-	guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
+	/*
+	 * Mark attach is in progress.  This makes validate_change() fail
+	 * changes which zero cpus/mems_allowed.
+	 */
+	cs->attach_in_progress++;
+	ret = 0;
+out_unlock:
+	mutex_unlock(&cpuset_mutex);
+	return ret;
+}
 
-	return 0;
+static void cpuset_cancel_attach(struct cgroup *cgrp,
+				 struct cgroup_taskset *tset)
+{
+	mutex_lock(&cpuset_mutex);
+	cgroup_cs(cgrp)->attach_in_progress--;
+	mutex_unlock(&cpuset_mutex);
 }
 
+/*
+ * Protected by cpuset_mutex.  cpus_attach is used only by cpuset_attach()
+ * but we can't allocate it dynamically there.  Define it global and
+ * allocate from cpuset_init().
+ */
+static cpumask_var_t cpus_attach;
+
 static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 {
+	/* static bufs protected by cpuset_mutex */
+	static nodemask_t cpuset_attach_nodemask_from;
+	static nodemask_t cpuset_attach_nodemask_to;
 	struct mm_struct *mm;
 	struct task_struct *task;
 	struct task_struct *leader = cgroup_taskset_first(tset);
@@ -1423,6 +1442,16 @@ static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 	struct cpuset *cs = cgroup_cs(cgrp);
 	struct cpuset *oldcs = cgroup_cs(oldcgrp);
 
+	mutex_lock(&cpuset_mutex);
+
+	/* prepare for attach */
+	if (cs == &top_cpuset)
+		cpumask_copy(cpus_attach, cpu_possible_mask);
+	else
+		guarantee_online_cpus(cs, cpus_attach);
+
+	guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
+
 	cgroup_taskset_for_each(task, cgrp, tset) {
 		/*
 		 * can_attach beforehand should guarantee that this doesn't
@@ -1448,6 +1477,18 @@ static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 					  &cpuset_attach_nodemask_to);
 		mmput(mm);
 	}
+
+	cs->attach_in_progress--;
+
+	/*
+	 * We may have raced with CPU/memory hotunplug.  Trigger hotplug
+	 * propagation if @cs doesn't have any CPU or memory.  It will move
+	 * the newly added tasks to the nearest parent which can execute.
+	 */
+	if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
+		schedule_cpuset_propagate_hotplug(cs);
+
+	mutex_unlock(&cpuset_mutex);
 }
 
 /* The various types of files and directories in a cpuset file system */
@@ -1469,12 +1510,13 @@ typedef enum {
 
 static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
 {
-	int retval = 0;
 	struct cpuset *cs = cgroup_cs(cgrp);
 	cpuset_filetype_t type = cft->private;
+	int retval = -ENODEV;
 
-	if (!cgroup_lock_live_group(cgrp))
-		return -ENODEV;
+	mutex_lock(&cpuset_mutex);
+	if (!is_cpuset_online(cs))
+		goto out_unlock;
 
 	switch (type) {
 	case FILE_CPU_EXCLUSIVE:
@@ -1508,18 +1550,20 @@ static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
 		retval = -EINVAL;
 		break;
 	}
-	cgroup_unlock();
+out_unlock:
+	mutex_unlock(&cpuset_mutex);
 	return retval;
 }
 
 static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
 {
-	int retval = 0;
 	struct cpuset *cs = cgroup_cs(cgrp);
 	cpuset_filetype_t type = cft->private;
+	int retval = -ENODEV;
 
-	if (!cgroup_lock_live_group(cgrp))
-		return -ENODEV;
+	mutex_lock(&cpuset_mutex);
+	if (!is_cpuset_online(cs))
+		goto out_unlock;
 
 	switch (type) {
 	case FILE_SCHED_RELAX_DOMAIN_LEVEL:
@@ -1529,7 +1573,8 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
 		retval = -EINVAL;
 		break;
 	}
-	cgroup_unlock();
+out_unlock:
+	mutex_unlock(&cpuset_mutex);
 	return retval;
 }
 
@@ -1539,17 +1584,36 @@ static int cpuset_write_s64(struct cgroup *cgrp, struct cftype *cft, s64 val)
 static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
 				const char *buf)
 {
-	int retval = 0;
 	struct cpuset *cs = cgroup_cs(cgrp);
 	struct cpuset *trialcs;
+	int retval = -ENODEV;
+
+	/*
+	 * CPU or memory hotunplug may leave @cs w/o any execution
+	 * resources, in which case the hotplug code asynchronously updates
+	 * configuration and transfers all tasks to the nearest ancestor
+	 * which can execute.
+	 *
+	 * As writes to "cpus" or "mems" may restore @cs's execution
+	 * resources, wait for the previously scheduled operations before
+	 * proceeding, so that we don't end up keep removing tasks added
+	 * after execution capability is restored.
+	 *
+	 * Flushing cpuset_hotplug_work is enough to synchronize against
+	 * hotplug hanlding; however, cpuset_attach() may schedule
+	 * propagation work directly.  Flush the workqueue too.
+	 */
+	flush_work(&cpuset_hotplug_work);
+	flush_workqueue(cpuset_propagate_hotplug_wq);
 
-	if (!cgroup_lock_live_group(cgrp))
-		return -ENODEV;
+	mutex_lock(&cpuset_mutex);
+	if (!is_cpuset_online(cs))
+		goto out_unlock;
 
 	trialcs = alloc_trial_cpuset(cs);
 	if (!trialcs) {
 		retval = -ENOMEM;
-		goto out;
+		goto out_unlock;
 	}
 
 	switch (cft->private) {
@@ -1565,8 +1629,8 @@ static int cpuset_write_resmask(struct cgroup *cgrp, struct cftype *cft,
 	}
 
 	free_trial_cpuset(trialcs);
-out:
-	cgroup_unlock();
+out_unlock:
+	mutex_unlock(&cpuset_mutex);
 	return retval;
 }
 
@@ -1790,15 +1854,12 @@ static struct cftype files[] = {
 
 static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont)
 {
-	struct cgroup *parent_cg = cont->parent;
-	struct cgroup *tmp_cg;
-	struct cpuset *parent, *cs;
+	struct cpuset *cs;
 
-	if (!parent_cg)
+	if (!cont->parent)
 		return &top_cpuset.css;
-	parent = cgroup_cs(parent_cg);
 
-	cs = kmalloc(sizeof(*cs), GFP_KERNEL);
+	cs = kzalloc(sizeof(*cs), GFP_KERNEL);
 	if (!cs)
 		return ERR_PTR(-ENOMEM);
 	if (!alloc_cpumask_var(&cs->cpus_allowed, GFP_KERNEL)) {
@@ -1806,22 +1867,38 @@ static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont)
 		return ERR_PTR(-ENOMEM);
 	}
 
-	cs->flags = 0;
-	if (is_spread_page(parent))
-		set_bit(CS_SPREAD_PAGE, &cs->flags);
-	if (is_spread_slab(parent))
-		set_bit(CS_SPREAD_SLAB, &cs->flags);
 	set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
 	cpumask_clear(cs->cpus_allowed);
 	nodes_clear(cs->mems_allowed);
 	fmeter_init(&cs->fmeter);
+	INIT_WORK(&cs->hotplug_work, cpuset_propagate_hotplug_workfn);
 	cs->relax_domain_level = -1;
 
-	cs->parent = parent;
+	return &cs->css;
+}
+
+static int cpuset_css_online(struct cgroup *cgrp)
+{
+	struct cpuset *cs = cgroup_cs(cgrp);
+	struct cpuset *parent = parent_cs(cs);
+	struct cpuset *tmp_cs;
+	struct cgroup *pos_cg;
+
+	if (!parent)
+		return 0;
+
+	mutex_lock(&cpuset_mutex);
+
+	set_bit(CS_ONLINE, &cs->flags);
+	if (is_spread_page(parent))
+		set_bit(CS_SPREAD_PAGE, &cs->flags);
+	if (is_spread_slab(parent))
+		set_bit(CS_SPREAD_SLAB, &cs->flags);
+
 	number_of_cpusets++;
 
-	if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cont->flags))
-		goto skip_clone;
+	if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags))
+		goto out_unlock;
 
 	/*
 	 * Clone @parent's configuration if CGRP_CPUSET_CLONE_CHILDREN is
@@ -1836,35 +1913,49 @@ static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont)
 	 * changed to grant parent->cpus_allowed-sibling_cpus_exclusive
 	 * (and likewise for mems) to the new cgroup.
 	 */
-	list_for_each_entry(tmp_cg, &parent_cg->children, sibling) {
-		struct cpuset *tmp_cs = cgroup_cs(tmp_cg);
-
-		if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs))
-			goto skip_clone;
+	rcu_read_lock();
+	cpuset_for_each_child(tmp_cs, pos_cg, parent) {
+		if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs)) {
+			rcu_read_unlock();
+			goto out_unlock;
+		}
 	}
+	rcu_read_unlock();
 
 	mutex_lock(&callback_mutex);
 	cs->mems_allowed = parent->mems_allowed;
 	cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
 	mutex_unlock(&callback_mutex);
-skip_clone:
-	return &cs->css;
+out_unlock:
+	mutex_unlock(&cpuset_mutex);
+	return 0;
+}
+
+static void cpuset_css_offline(struct cgroup *cgrp)
+{
+	struct cpuset *cs = cgroup_cs(cgrp);
+
+	mutex_lock(&cpuset_mutex);
+
+	if (is_sched_load_balance(cs))
+		update_flag(CS_SCHED_LOAD_BALANCE, cs, 0);
+
+	number_of_cpusets--;
+	clear_bit(CS_ONLINE, &cs->flags);
+
+	mutex_unlock(&cpuset_mutex);
 }
 
 /*
  * If the cpuset being removed has its flag 'sched_load_balance'
  * enabled, then simulate turning sched_load_balance off, which
- * will call async_rebuild_sched_domains().
+ * will call rebuild_sched_domains_locked().
  */
 
 static void cpuset_css_free(struct cgroup *cont)
 {
 	struct cpuset *cs = cgroup_cs(cont);
 
-	if (is_sched_load_balance(cs))
-		update_flag(CS_SCHED_LOAD_BALANCE, cs, 0);
-
-	number_of_cpusets--;
 	free_cpumask_var(cs->cpus_allowed);
 	kfree(cs);
 }
@@ -1872,8 +1963,11 @@ static void cpuset_css_free(struct cgroup *cont)
 struct cgroup_subsys cpuset_subsys = {
 	.name = "cpuset",
 	.css_alloc = cpuset_css_alloc,
+	.css_online = cpuset_css_online,
+	.css_offline = cpuset_css_offline,
 	.css_free = cpuset_css_free,
 	.can_attach = cpuset_can_attach,
+	.cancel_attach = cpuset_cancel_attach,
 	.attach = cpuset_attach,
 	.subsys_id = cpuset_subsys_id,
 	.base_cftypes = files,
@@ -1924,7 +2018,9 @@ static void cpuset_do_move_task(struct task_struct *tsk,
 {
 	struct cgroup *new_cgroup = scan->data;
 
+	cgroup_lock();
 	cgroup_attach_task(new_cgroup, tsk);
+	cgroup_unlock();
 }
 
 /**
@@ -1932,7 +2028,7 @@ static void cpuset_do_move_task(struct task_struct *tsk,
  * @from: cpuset in which the tasks currently reside
  * @to: cpuset to which the tasks will be moved
  *
- * Called with cgroup_mutex held
+ * Called with cpuset_mutex held
  * callback_mutex must not be held, as cpuset_attach() will take it.
  *
  * The cgroup_scan_tasks() function will scan all the tasks in a cgroup,
@@ -1959,169 +2055,200 @@ static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to)
  * removing that CPU or node from all cpusets.  If this removes the
  * last CPU or node from a cpuset, then move the tasks in the empty
  * cpuset to its next-highest non-empty parent.
- *
- * Called with cgroup_mutex held
- * callback_mutex must not be held, as cpuset_attach() will take it.
  */
 static void remove_tasks_in_empty_cpuset(struct cpuset *cs)
 {
 	struct cpuset *parent;
 
 	/*
-	 * The cgroup's css_sets list is in use if there are tasks
-	 * in the cpuset; the list is empty if there are none;
-	 * the cs->css.refcnt seems always 0.
-	 */
-	if (list_empty(&cs->css.cgroup->css_sets))
-		return;
-
-	/*
 	 * Find its next-highest non-empty parent, (top cpuset
 	 * has online cpus, so can't be empty).
 	 */
-	parent = cs->parent;
+	parent = parent_cs(cs);
 	while (cpumask_empty(parent->cpus_allowed) ||
 			nodes_empty(parent->mems_allowed))
-		parent = parent->parent;
+		parent = parent_cs(parent);
 
 	move_member_tasks_to_cpuset(cs, parent);
 }
 
-/*
- * Helper function to traverse cpusets.
- * It can be used to walk the cpuset tree from top to bottom, completing
- * one layer before dropping down to the next (thus always processing a
- * node before any of its children).
+/**
+ * cpuset_propagate_hotplug_workfn - propagate CPU/memory hotplug to a cpuset
+ * @cs: cpuset in interest
+ *
+ * Compare @cs's cpu and mem masks against top_cpuset and if some have gone
+ * offline, update @cs accordingly.  If @cs ends up with no CPU or memory,
+ * all its tasks are moved to the nearest ancestor with both resources.
  */
-static struct cpuset *cpuset_next(struct list_head *queue)
+static void cpuset_propagate_hotplug_workfn(struct work_struct *work)
 {
-	struct cpuset *cp;
-	struct cpuset *child;	/* scans child cpusets of cp */
-	struct cgroup *cont;
+	static cpumask_t off_cpus;
+	static nodemask_t off_mems, tmp_mems;
+	struct cpuset *cs = container_of(work, struct cpuset, hotplug_work);
+	bool is_empty;
 
-	if (list_empty(queue))
-		return NULL;
+	mutex_lock(&cpuset_mutex);
+
+	cpumask_andnot(&off_cpus, cs->cpus_allowed, top_cpuset.cpus_allowed);
+	nodes_andnot(off_mems, cs->mems_allowed, top_cpuset.mems_allowed);
 
-	cp = list_first_entry(queue, struct cpuset, stack_list);
-	list_del(queue->next);
-	list_for_each_entry(cont, &cp->css.cgroup->children, sibling) {
-		child = cgroup_cs(cont);
-		list_add_tail(&child->stack_list, queue);
+	/* remove offline cpus from @cs */
+	if (!cpumask_empty(&off_cpus)) {
+		mutex_lock(&callback_mutex);
+		cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, &off_cpus);
+		mutex_unlock(&callback_mutex);
+		update_tasks_cpumask(cs, NULL);
+	}
+
+	/* remove offline mems from @cs */
+	if (!nodes_empty(off_mems)) {
+		tmp_mems = cs->mems_allowed;
+		mutex_lock(&callback_mutex);
+		nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems);
+		mutex_unlock(&callback_mutex);
+		update_tasks_nodemask(cs, &tmp_mems, NULL);
 	}
 
-	return cp;
+	is_empty = cpumask_empty(cs->cpus_allowed) ||
+		nodes_empty(cs->mems_allowed);
+
+	mutex_unlock(&cpuset_mutex);
+
+	/*
+	 * If @cs became empty, move tasks to the nearest ancestor with
+	 * execution resources.  This is full cgroup operation which will
+	 * also call back into cpuset.  Should be done outside any lock.
+	 */
+	if (is_empty)
+		remove_tasks_in_empty_cpuset(cs);
+
+	/* the following may free @cs, should be the last operation */
+	css_put(&cs->css);
 }
 
+/**
+ * schedule_cpuset_propagate_hotplug - schedule hotplug propagation to a cpuset
+ * @cs: cpuset of interest
+ *
+ * Schedule cpuset_propagate_hotplug_workfn() which will update CPU and
+ * memory masks according to top_cpuset.
+ */
+static void schedule_cpuset_propagate_hotplug(struct cpuset *cs)
+{
+	/*
+	 * Pin @cs.  The refcnt will be released when the work item
+	 * finishes executing.
+	 */
+	if (!css_tryget(&cs->css))
+		return;
 
-/*
- * Walk the specified cpuset subtree upon a hotplug operation (CPU/Memory
- * online/offline) and update the cpusets accordingly.
- * For regular CPU/Mem hotplug, look for empty cpusets; the tasks of such
- * cpuset must be moved to a parent cpuset.
+	/*
+	 * Queue @cs->hotplug_work.  If already pending, lose the css ref.
+	 * cpuset_propagate_hotplug_wq is ordered and propagation will
+	 * happen in the order this function is called.
+	 */
+	if (!queue_work(cpuset_propagate_hotplug_wq, &cs->hotplug_work))
+		css_put(&cs->css);
+}
+
+/**
+ * cpuset_hotplug_workfn - handle CPU/memory hotunplug for a cpuset
  *
- * Called with cgroup_mutex held.  We take callback_mutex to modify
- * cpus_allowed and mems_allowed.
+ * This function is called after either CPU or memory configuration has
+ * changed and updates cpuset accordingly.  The top_cpuset is always
+ * synchronized to cpu_active_mask and N_MEMORY, which is necessary in
+ * order to make cpusets transparent (of no affect) on systems that are
+ * actively using CPU hotplug but making no active use of cpusets.
  *
- * This walk processes the tree from top to bottom, completing one layer
- * before dropping down to the next.  It always processes a node before
- * any of its children.
+ * Non-root cpusets are only affected by offlining.  If any CPUs or memory
+ * nodes have been taken down, cpuset_propagate_hotplug() is invoked on all
+ * descendants.
  *
- * In the case of memory hot-unplug, it will remove nodes from N_MEMORY
- * if all present pages from a node are offlined.
+ * Note that CPU offlining during suspend is ignored.  We don't modify
+ * cpusets across suspend/resume cycles at all.
  */
-static void
-scan_cpusets_upon_hotplug(struct cpuset *root, enum hotplug_event event)
+static void cpuset_hotplug_workfn(struct work_struct *work)
 {
-	LIST_HEAD(queue);
-	struct cpuset *cp;		/* scans cpusets being updated */
-	static nodemask_t oldmems;	/* protected by cgroup_mutex */
+	static cpumask_t new_cpus, tmp_cpus;
+	static nodemask_t new_mems, tmp_mems;
+	bool cpus_updated, mems_updated;
+	bool cpus_offlined, mems_offlined;
 
-	list_add_tail((struct list_head *)&root->stack_list, &queue);
+	mutex_lock(&cpuset_mutex);
 
-	switch (event) {
-	case CPUSET_CPU_OFFLINE:
-		while ((cp = cpuset_next(&queue)) != NULL) {
+	/* fetch the available cpus/mems and find out which changed how */
+	cpumask_copy(&new_cpus, cpu_active_mask);
+	new_mems = node_states[N_MEMORY];
 
-			/* Continue past cpusets with all cpus online */
-			if (cpumask_subset(cp->cpus_allowed, cpu_active_mask))
-				continue;
+	cpus_updated = !cpumask_equal(top_cpuset.cpus_allowed, &new_cpus);
+	cpus_offlined = cpumask_andnot(&tmp_cpus, top_cpuset.cpus_allowed,
+				       &new_cpus);
 
-			/* Remove offline cpus from this cpuset. */
-			mutex_lock(&callback_mutex);
-			cpumask_and(cp->cpus_allowed, cp->cpus_allowed,
-							cpu_active_mask);
-			mutex_unlock(&callback_mutex);
+	mems_updated = !nodes_equal(top_cpuset.mems_allowed, new_mems);
+	nodes_andnot(tmp_mems, top_cpuset.mems_allowed, new_mems);
+	mems_offlined = !nodes_empty(tmp_mems);
 
-			/* Move tasks from the empty cpuset to a parent */
-			if (cpumask_empty(cp->cpus_allowed))
-				remove_tasks_in_empty_cpuset(cp);
-			else
-				update_tasks_cpumask(cp, NULL);
-		}
-		break;
+	/* synchronize cpus_allowed to cpu_active_mask */
+	if (cpus_updated) {
+		mutex_lock(&callback_mutex);
+		cpumask_copy(top_cpuset.cpus_allowed, &new_cpus);
+		mutex_unlock(&callback_mutex);
+		/* we don't mess with cpumasks of tasks in top_cpuset */
+	}
 
-	case CPUSET_MEM_OFFLINE:
-		while ((cp = cpuset_next(&queue)) != NULL) {
+	/* synchronize mems_allowed to N_MEMORY */
+	if (mems_updated) {
+		tmp_mems = top_cpuset.mems_allowed;
+		mutex_lock(&callback_mutex);
+		top_cpuset.mems_allowed = new_mems;
+		mutex_unlock(&callback_mutex);
+		update_tasks_nodemask(&top_cpuset, &tmp_mems, NULL);
+	}
 
-			/* Continue past cpusets with all mems online */
-			if (nodes_subset(cp->mems_allowed,
-					node_states[N_MEMORY]))
-				continue;
+	/* if cpus or mems went down, we need to propagate to descendants */
+	if (cpus_offlined || mems_offlined) {
+		struct cpuset *cs;
+		struct cgroup *pos_cgrp;
 
-			oldmems = cp->mems_allowed;
+		rcu_read_lock();
+		cpuset_for_each_descendant_pre(cs, pos_cgrp, &top_cpuset)
+			schedule_cpuset_propagate_hotplug(cs);
+		rcu_read_unlock();
+	}
 
-			/* Remove offline mems from this cpuset. */
-			mutex_lock(&callback_mutex);
-			nodes_and(cp->mems_allowed, cp->mems_allowed,
-						node_states[N_MEMORY]);
-			mutex_unlock(&callback_mutex);
+	mutex_unlock(&cpuset_mutex);
 
-			/* Move tasks from the empty cpuset to a parent */
-			if (nodes_empty(cp->mems_allowed))
-				remove_tasks_in_empty_cpuset(cp);
-			else
-				update_tasks_nodemask(cp, &oldmems, NULL);
-		}
+	/* wait for propagations to finish */
+	flush_workqueue(cpuset_propagate_hotplug_wq);
+
+	/* rebuild sched domains if cpus_allowed has changed */
+	if (cpus_updated) {
+		struct sched_domain_attr *attr;
+		cpumask_var_t *doms;
+		int ndoms;
+
+		mutex_lock(&cpuset_mutex);
+		ndoms = generate_sched_domains(&doms, &attr);
+		mutex_unlock(&cpuset_mutex);
+
+		partition_sched_domains(ndoms, doms, attr);
 	}
 }
 
-/*
- * The top_cpuset tracks what CPUs and Memory Nodes are online,
- * period.  This is necessary in order to make cpusets transparent
- * (of no affect) on systems that are actively using CPU hotplug
- * but making no active use of cpusets.
- *
- * The only exception to this is suspend/resume, where we don't
- * modify cpusets at all.
- *
- * This routine ensures that top_cpuset.cpus_allowed tracks
- * cpu_active_mask on each CPU hotplug (cpuhp) event.
- *
- * Called within get_online_cpus().  Needs to call cgroup_lock()
- * before calling generate_sched_domains().
- *
- * @cpu_online: Indicates whether this is a CPU online event (true) or
- * a CPU offline event (false).
- */
 void cpuset_update_active_cpus(bool cpu_online)
 {
-	struct sched_domain_attr *attr;
-	cpumask_var_t *doms;
-	int ndoms;
-
-	cgroup_lock();
-	mutex_lock(&callback_mutex);
-	cpumask_copy(top_cpuset.cpus_allowed, cpu_active_mask);
-	mutex_unlock(&callback_mutex);
-
-	if (!cpu_online)
-		scan_cpusets_upon_hotplug(&top_cpuset, CPUSET_CPU_OFFLINE);
-
-	ndoms = generate_sched_domains(&doms, &attr);
-	cgroup_unlock();
-
-	/* Have scheduler rebuild the domains */
-	partition_sched_domains(ndoms, doms, attr);
+	/*
+	 * We're inside cpu hotplug critical region which usually nests
+	 * inside cgroup synchronization.  Bounce actual hotplug processing
+	 * to a work item to avoid reverse locking order.
+	 *
+	 * We still need to do partition_sched_domains() synchronously;
+	 * otherwise, the scheduler will get confused and put tasks to the
+	 * dead CPU.  Fall back to the default single domain.
+	 * cpuset_hotplug_workfn() will rebuild it as necessary.
+	 */
+	partition_sched_domains(1, NULL, NULL);
+	schedule_work(&cpuset_hotplug_work);
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
@@ -2133,29 +2260,7 @@ void cpuset_update_active_cpus(bool cpu_online)
 static int cpuset_track_online_nodes(struct notifier_block *self,
 				unsigned long action, void *arg)
 {
-	static nodemask_t oldmems;	/* protected by cgroup_mutex */
-
-	cgroup_lock();
-	switch (action) {
-	case MEM_ONLINE:
-		oldmems = top_cpuset.mems_allowed;
-		mutex_lock(&callback_mutex);
-		top_cpuset.mems_allowed = node_states[N_MEMORY];
-		mutex_unlock(&callback_mutex);
-		update_tasks_nodemask(&top_cpuset, &oldmems, NULL);
-		break;
-	case MEM_OFFLINE:
-		/*
-		 * needn't update top_cpuset.mems_allowed explicitly because
-		 * scan_cpusets_upon_hotplug() will update it.
-		 */
-		scan_cpusets_upon_hotplug(&top_cpuset, CPUSET_MEM_OFFLINE);
-		break;
-	default:
-		break;
-	}
-	cgroup_unlock();
-
+	schedule_work(&cpuset_hotplug_work);
 	return NOTIFY_OK;
 }
 #endif
@@ -2173,8 +2278,9 @@ void __init cpuset_init_smp(void)
 
 	hotplug_memory_notifier(cpuset_track_online_nodes, 10);
 
-	cpuset_wq = create_singlethread_workqueue("cpuset");
-	BUG_ON(!cpuset_wq);
+	cpuset_propagate_hotplug_wq =
+		alloc_ordered_workqueue("cpuset_hotplug", 0);
+	BUG_ON(!cpuset_propagate_hotplug_wq);
 }
 
 /**
@@ -2273,8 +2379,8 @@ int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask)
  */
 static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs)
 {
-	while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && cs->parent)
-		cs = cs->parent;
+	while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && parent_cs(cs))
+		cs = parent_cs(cs);
 	return cs;
 }
 
@@ -2412,17 +2518,6 @@ int __cpuset_node_allowed_hardwall(int node, gfp_t gfp_mask)
 }
 
 /**
- * cpuset_unlock - release lock on cpuset changes
- *
- * Undo the lock taken in a previous cpuset_lock() call.
- */
-
-void cpuset_unlock(void)
-{
-	mutex_unlock(&callback_mutex);
-}
-
-/**
  * cpuset_mem_spread_node() - On which node to begin search for a file page
  * cpuset_slab_spread_node() - On which node to begin search for a slab page
  *
@@ -2511,8 +2606,16 @@ void cpuset_print_task_mems_allowed(struct task_struct *tsk)
 
 	dentry = task_cs(tsk)->css.cgroup->dentry;
 	spin_lock(&cpuset_buffer_lock);
-	snprintf(cpuset_name, CPUSET_NAME_LEN,
-		 dentry ? (const char *)dentry->d_name.name : "/");
+
+	if (!dentry) {
+		strcpy(cpuset_name, "/");
+	} else {
+		spin_lock(&dentry->d_lock);
+		strlcpy(cpuset_name, (const char *)dentry->d_name.name,
+			CPUSET_NAME_LEN);
+		spin_unlock(&dentry->d_lock);
+	}
+
 	nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN,
 			   tsk->mems_allowed);
 	printk(KERN_INFO "%s cpuset=%s mems_allowed=%s\n",
@@ -2560,7 +2663,7 @@ void __cpuset_memory_pressure_bump(void)
  *  - Used for /proc/<pid>/cpuset.
  *  - No need to task_lock(tsk) on this tsk->cpuset reference, as it
  *    doesn't really matter if tsk->cpuset changes after we read it,
- *    and we take cgroup_mutex, keeping cpuset_attach() from changing it
+ *    and we take cpuset_mutex, keeping cpuset_attach() from changing it
  *    anyway.
  */
 static int proc_cpuset_show(struct seq_file *m, void *unused_v)
@@ -2582,16 +2685,15 @@ static int proc_cpuset_show(struct seq_file *m, void *unused_v)
 	if (!tsk)
 		goto out_free;
 
-	retval = -EINVAL;
-	cgroup_lock();
+	rcu_read_lock();
 	css = task_subsys_state(tsk, cpuset_subsys_id);
 	retval = cgroup_path(css->cgroup, buf, PAGE_SIZE);
+	rcu_read_unlock();
 	if (retval < 0)
-		goto out_unlock;
+		goto out_put_task;
 	seq_puts(m, buf);
 	seq_putc(m, '\n');
-out_unlock:
-	cgroup_unlock();
+out_put_task:
 	put_task_struct(tsk);
 out_free:
 	kfree(buf);
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 9a61738cefc8..c26278fd4851 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -29,6 +29,7 @@
  */
 #include <linux/pid_namespace.h>
 #include <linux/clocksource.h>
+#include <linux/serial_core.h>
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
 #include <linux/console.h>
diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h
index 3494c28a7e7a..2235967e78b0 100644
--- a/kernel/debug/debug_core.h
+++ b/kernel/debug/debug_core.h
@@ -72,6 +72,8 @@ extern int dbg_kdb_mode;
 #ifdef CONFIG_KGDB_KDB
 extern int kdb_stub(struct kgdb_state *ks);
 extern int kdb_parse(const char *cmdstr);
+extern int kdb_common_init_state(struct kgdb_state *ks);
+extern int kdb_common_deinit_state(void);
 #else /* ! CONFIG_KGDB_KDB */
 static inline int kdb_stub(struct kgdb_state *ks)
 {
diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index ce615e064482..19d9a578c753 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -31,6 +31,7 @@
 #include <linux/kernel.h>
 #include <linux/kgdb.h>
 #include <linux/kdb.h>
+#include <linux/serial_core.h>
 #include <linux/reboot.h>
 #include <linux/uaccess.h>
 #include <asm/cacheflush.h>
@@ -782,7 +783,10 @@ static void gdb_cmd_query(struct kgdb_state *ks)
 			len = len / 2;
 			remcom_out_buffer[len++] = 0;
 
+			kdb_common_init_state(ks);
 			kdb_parse(remcom_out_buffer);
+			kdb_common_deinit_state();
+
 			strcpy(remcom_out_buffer, "OK");
 		}
 		break;
diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index 8418c2f8ec5d..70a504601dc3 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -486,11 +486,9 @@ static int kdb_bc(int argc, const char **argv)
 /*
  * kdb_ss
  *
- *	Process the 'ss' (Single Step) and 'ssb' (Single Step to Branch)
- *	commands.
+ *	Process the 'ss' (Single Step) command.
  *
  *	ss
- *	ssb
  *
  * Parameters:
  *	argc	Argument count
@@ -498,35 +496,23 @@ static int kdb_bc(int argc, const char **argv)
  * Outputs:
  *	None.
  * Returns:
- *	KDB_CMD_SS[B] for success, a kdb error if failure.
+ *	KDB_CMD_SS for success, a kdb error if failure.
  * Locking:
  *	None.
  * Remarks:
  *
  *	Set the arch specific option to trigger a debug trap after the next
  *	instruction.
- *
- *	For 'ssb', set the trace flag in the debug trap handler
- *	after printing the current insn and return directly without
- *	invoking the kdb command processor, until a branch instruction
- *	is encountered.
  */
 
 static int kdb_ss(int argc, const char **argv)
 {
-	int ssb = 0;
-
-	ssb = (strcmp(argv[0], "ssb") == 0);
 	if (argc != 0)
 		return KDB_ARGCOUNT;
 	/*
 	 * Set trace flag and go.
 	 */
 	KDB_STATE_SET(DOING_SS);
-	if (ssb) {
-		KDB_STATE_SET(DOING_SSB);
-		return KDB_CMD_SSB;
-	}
 	return KDB_CMD_SS;
 }
 
@@ -561,8 +547,6 @@ void __init kdb_initbptab(void)
 
 	kdb_register_repeat("ss", kdb_ss, "",
 		"Single Step", 1, KDB_REPEAT_NO_ARGS);
-	kdb_register_repeat("ssb", kdb_ss, "",
-		"Single step to branch/call", 0, KDB_REPEAT_NO_ARGS);
 	/*
 	 * Architecture dependent initialization.
 	 */
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index be7b33b73d30..328d18ef31e4 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -34,6 +34,22 @@ EXPORT_SYMBOL_GPL(kdb_poll_idx);
 
 static struct kgdb_state *kdb_ks;
 
+int kdb_common_init_state(struct kgdb_state *ks)
+{
+	kdb_initial_cpu = atomic_read(&kgdb_active);
+	kdb_current_task = kgdb_info[ks->cpu].task;
+	kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo;
+	return 0;
+}
+
+int kdb_common_deinit_state(void)
+{
+	kdb_initial_cpu = -1;
+	kdb_current_task = NULL;
+	kdb_current_regs = NULL;
+	return 0;
+}
+
 int kdb_stub(struct kgdb_state *ks)
 {
 	int error = 0;
@@ -94,13 +110,10 @@ int kdb_stub(struct kgdb_state *ks)
 	}
 	/* Set initial kdb state variables */
 	KDB_STATE_CLEAR(KGDB_TRANS);
-	kdb_initial_cpu = atomic_read(&kgdb_active);
-	kdb_current_task = kgdb_info[ks->cpu].task;
-	kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo;
+	kdb_common_init_state(ks);
 	/* Remove any breakpoints as needed by kdb and clear single step */
 	kdb_bp_remove();
 	KDB_STATE_CLEAR(DOING_SS);
-	KDB_STATE_CLEAR(DOING_SSB);
 	KDB_STATE_SET(PAGER);
 	/* zero out any offline cpu data */
 	for_each_present_cpu(i) {
@@ -125,9 +138,7 @@ int kdb_stub(struct kgdb_state *ks)
 	 * Upon exit from the kdb main loop setup break points and restart
 	 * the system based on the requested continue state
 	 */
-	kdb_initial_cpu = -1;
-	kdb_current_task = NULL;
-	kdb_current_regs = NULL;
+	kdb_common_deinit_state();
 	KDB_STATE_CLEAR(PAGER);
 	kdbnearsym_cleanup();
 	if (error == KDB_CMD_KGDB) {
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 8875254120b6..00eb8f7fbf41 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -124,7 +124,7 @@ static kdbmsg_t kdbmsgs[] = {
 };
 #undef KDBMSG
 
-static const int __nkdb_err = sizeof(kdbmsgs) / sizeof(kdbmsg_t);
+static const int __nkdb_err = ARRAY_SIZE(kdbmsgs);
 
 
 /*
@@ -175,7 +175,7 @@ static char *__env[] = {
  (char *)0,
 };
 
-static const int __nenv = (sizeof(__env) / sizeof(char *));
+static const int __nenv = ARRAY_SIZE(__env);
 
 struct task_struct *kdb_curr_task(int cpu)
 {
@@ -681,34 +681,50 @@ static int kdb_defcmd(int argc, const char **argv)
 	}
 	if (argc != 3)
 		return KDB_ARGCOUNT;
-	defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set),
-			     GFP_KDB);
-	if (!defcmd_set) {
-		kdb_printf("Could not allocate new defcmd_set entry for %s\n",
-			   argv[1]);
-		defcmd_set = save_defcmd_set;
+	if (in_dbg_master()) {
+		kdb_printf("Command only available during kdb_init()\n");
 		return KDB_NOTIMP;
 	}
+	defcmd_set = kmalloc((defcmd_set_count + 1) * sizeof(*defcmd_set),
+			     GFP_KDB);
+	if (!defcmd_set)
+		goto fail_defcmd;
 	memcpy(defcmd_set, save_defcmd_set,
 	       defcmd_set_count * sizeof(*defcmd_set));
-	kfree(save_defcmd_set);
 	s = defcmd_set + defcmd_set_count;
 	memset(s, 0, sizeof(*s));
 	s->usable = 1;
 	s->name = kdb_strdup(argv[1], GFP_KDB);
+	if (!s->name)
+		goto fail_name;
 	s->usage = kdb_strdup(argv[2], GFP_KDB);
+	if (!s->usage)
+		goto fail_usage;
 	s->help = kdb_strdup(argv[3], GFP_KDB);
+	if (!s->help)
+		goto fail_help;
 	if (s->usage[0] == '"') {
-		strcpy(s->usage, s->usage+1);
+		strcpy(s->usage, argv[2]+1);
 		s->usage[strlen(s->usage)-1] = '\0';
 	}
 	if (s->help[0] == '"') {
-		strcpy(s->help, s->help+1);
+		strcpy(s->help, argv[3]+1);
 		s->help[strlen(s->help)-1] = '\0';
 	}
 	++defcmd_set_count;
 	defcmd_in_progress = 1;
+	kfree(save_defcmd_set);
 	return 0;
+fail_help:
+	kfree(s->usage);
+fail_usage:
+	kfree(s->name);
+fail_name:
+	kfree(defcmd_set);
+fail_defcmd:
+	kdb_printf("Could not allocate new defcmd_set entry for %s\n", argv[1]);
+	defcmd_set = save_defcmd_set;
+	return KDB_NOTIMP;
 }
 
 /*
@@ -1112,7 +1128,6 @@ void kdb_set_current_task(struct task_struct *p)
  *	KDB_CMD_GO	User typed 'go'.
  *	KDB_CMD_CPU	User switched to another cpu.
  *	KDB_CMD_SS	Single step.
- *	KDB_CMD_SSB	Single step until branch.
  */
 static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
 		     kdb_dbtrap_t db_result)
@@ -1151,14 +1166,6 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
 			kdb_printf("due to Debug @ " kdb_machreg_fmt "\n",
 				   instruction_pointer(regs));
 			break;
-		case KDB_DB_SSB:
-			/*
-			 * In the midst of ssb command. Just return.
-			 */
-			KDB_DEBUG_STATE("kdb_local 3", reason);
-			return KDB_CMD_SSB;	/* Continue with SSB command */
-
-			break;
 		case KDB_DB_SS:
 			break;
 		case KDB_DB_SSBPT:
@@ -1281,7 +1288,6 @@ do_full_getstr:
 		if (diag == KDB_CMD_GO
 		 || diag == KDB_CMD_CPU
 		 || diag == KDB_CMD_SS
-		 || diag == KDB_CMD_SSB
 		 || diag == KDB_CMD_KGDB)
 			break;
 
@@ -1368,12 +1374,6 @@ int kdb_main_loop(kdb_reason_t reason, kdb_reason_t reason2, int error,
 			break;
 		}
 
-		if (result == KDB_CMD_SSB) {
-			KDB_STATE_SET(DOING_SS);
-			KDB_STATE_SET(DOING_SSB);
-			break;
-		}
-
 		if (result == KDB_CMD_KGDB) {
 			if (!KDB_STATE(DOING_KGDB))
 				kdb_printf("Entering please attach debugger "
@@ -2350,69 +2350,6 @@ static int kdb_pid(int argc, const char **argv)
 	return 0;
 }
 
-/*
- * kdb_ll - This function implements the 'll' command which follows a
- *	linked list and executes an arbitrary command for each
- *	element.
- */
-static int kdb_ll(int argc, const char **argv)
-{
-	int diag = 0;
-	unsigned long addr;
-	long offset = 0;
-	unsigned long va;
-	unsigned long linkoffset;
-	int nextarg;
-	const char *command;
-
-	if (argc != 3)
-		return KDB_ARGCOUNT;
-
-	nextarg = 1;
-	diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL);
-	if (diag)
-		return diag;
-
-	diag = kdbgetularg(argv[2], &linkoffset);
-	if (diag)
-		return diag;
-
-	/*
-	 * Using the starting address as
-	 * the first element in the list, and assuming that
-	 * the list ends with a null pointer.
-	 */
-
-	va = addr;
-	command = kdb_strdup(argv[3], GFP_KDB);
-	if (!command) {
-		kdb_printf("%s: cannot duplicate command\n", __func__);
-		return 0;
-	}
-	/* Recursive use of kdb_parse, do not use argv after this point */
-	argv = NULL;
-
-	while (va) {
-		char buf[80];
-
-		if (KDB_FLAG(CMD_INTERRUPT))
-			goto out;
-
-		sprintf(buf, "%s " kdb_machreg_fmt "\n", command, va);
-		diag = kdb_parse(buf);
-		if (diag)
-			goto out;
-
-		addr = va + linkoffset;
-		if (kdb_getword(&va, addr, sizeof(va)))
-			goto out;
-	}
-
-out:
-	kfree(command);
-	return diag;
-}
-
 static int kdb_kgdb(int argc, const char **argv)
 {
 	return KDB_CMD_KGDB;
@@ -2430,11 +2367,15 @@ static int kdb_help(int argc, const char **argv)
 	kdb_printf("-----------------------------"
 		   "-----------------------------\n");
 	for_each_kdbcmd(kt, i) {
-		if (kt->cmd_name)
-			kdb_printf("%-15.15s %-20.20s %s\n", kt->cmd_name,
-				   kt->cmd_usage, kt->cmd_help);
+		char *space = "";
 		if (KDB_FLAG(CMD_INTERRUPT))
 			return 0;
+		if (!kt->cmd_name)
+			continue;
+		if (strlen(kt->cmd_usage) > 20)
+			space = "\n                                    ";
+		kdb_printf("%-15.15s %-20s%s%s\n", kt->cmd_name,
+			   kt->cmd_usage, space, kt->cmd_help);
 	}
 	return 0;
 }
@@ -2739,7 +2680,7 @@ int kdb_register_repeat(char *cmd,
 			  (kdb_max_commands - KDB_BASE_CMD_MAX) * sizeof(*new));
 			kfree(kdb_commands);
 		}
-		memset(new + kdb_max_commands, 0,
+		memset(new + kdb_max_commands - KDB_BASE_CMD_MAX, 0,
 		       kdb_command_extend * sizeof(*new));
 		kdb_commands = new;
 		kp = kdb_commands + kdb_max_commands - KDB_BASE_CMD_MAX;
@@ -2843,15 +2784,13 @@ static void __init kdb_inittab(void)
 	  "Stack traceback", 1, KDB_REPEAT_NONE);
 	kdb_register_repeat("btp", kdb_bt, "<pid>",
 	  "Display stack for process <pid>", 0, KDB_REPEAT_NONE);
-	kdb_register_repeat("bta", kdb_bt, "[DRSTCZEUIMA]",
-	  "Display stack all processes", 0, KDB_REPEAT_NONE);
+	kdb_register_repeat("bta", kdb_bt, "[D|R|S|T|C|Z|E|U|I|M|A]",
+	  "Backtrace all processes matching state flag", 0, KDB_REPEAT_NONE);
 	kdb_register_repeat("btc", kdb_bt, "",
 	  "Backtrace current process on each cpu", 0, KDB_REPEAT_NONE);
 	kdb_register_repeat("btt", kdb_bt, "<vaddr>",
 	  "Backtrace process given its struct task address", 0,
 			    KDB_REPEAT_NONE);
-	kdb_register_repeat("ll", kdb_ll, "<first-element> <linkoffset> <cmd>",
-	  "Execute cmd for each element in linked list", 0, KDB_REPEAT_NONE);
 	kdb_register_repeat("env", kdb_env, "",
 	  "Show environment variables", 0, KDB_REPEAT_NONE);
 	kdb_register_repeat("set", kdb_set, "",
diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h
index 392ec6a25844..7afd3c8c41d5 100644
--- a/kernel/debug/kdb/kdb_private.h
+++ b/kernel/debug/kdb/kdb_private.h
@@ -19,7 +19,6 @@
 #define KDB_CMD_GO	(-1001)
 #define KDB_CMD_CPU	(-1002)
 #define KDB_CMD_SS	(-1003)
-#define KDB_CMD_SSB	(-1004)
 #define KDB_CMD_KGDB (-1005)
 
 /* Internal debug flags */
@@ -125,8 +124,6 @@ extern int kdb_state;
 						 * kdb control */
 #define KDB_STATE_HOLD_CPU	0x00000010	/* Hold this cpu inside kdb */
 #define KDB_STATE_DOING_SS	0x00000020	/* Doing ss command */
-#define KDB_STATE_DOING_SSB	0x00000040	/* Doing ssb command,
-						 * DOING_SS is also set */
 #define KDB_STATE_SSBPT		0x00000080	/* Install breakpoint
 						 * after one ss, independent of
 						 * DOING_SS */
@@ -191,7 +188,6 @@ extern void kdb_bp_remove(void);
 typedef enum {
 	KDB_DB_BPT,	/* Breakpoint */
 	KDB_DB_SS,	/* Single-step trap */
-	KDB_DB_SSB,	/* Single step to branch */
 	KDB_DB_SSBPT,	/* Single step over breakpoint */
 	KDB_DB_NOBPT	/* Spurious breakpoint */
 } kdb_dbtrap_t;
diff --git a/kernel/delayacct.c b/kernel/delayacct.c
index 418b3f7053aa..d473988c1d0b 100644
--- a/kernel/delayacct.c
+++ b/kernel/delayacct.c
@@ -106,6 +106,7 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
 	unsigned long long t2, t3;
 	unsigned long flags;
 	struct timespec ts;
+	cputime_t utime, stime, stimescaled, utimescaled;
 
 	/* Though tsk->delays accessed later, early exit avoids
 	 * unnecessary returning of other data
@@ -114,12 +115,14 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
 		goto done;
 
 	tmp = (s64)d->cpu_run_real_total;
-	cputime_to_timespec(tsk->utime + tsk->stime, &ts);
+	task_cputime(tsk, &utime, &stime);
+	cputime_to_timespec(utime + stime, &ts);
 	tmp += timespec_to_ns(&ts);
 	d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
 
 	tmp = (s64)d->cpu_scaled_run_real_total;
-	cputime_to_timespec(tsk->utimescaled + tsk->stimescaled, &ts);
+	task_cputime_scaled(tsk, &utimescaled, &stimescaled);
+	cputime_to_timespec(utimescaled + stimescaled, &ts);
 	tmp += timespec_to_ns(&ts);
 	d->cpu_scaled_run_real_total =
 		(tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 7b6646a8c067..b0cd86501c30 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3691,7 +3691,7 @@ unlock:
 
 static int perf_fasync(int fd, struct file *filp, int on)
 {
-	struct inode *inode = filp->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(filp);
 	struct perf_event *event = filp->private_data;
 	int retval;
 
@@ -5126,7 +5126,6 @@ static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
 {
 	struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
 	struct perf_event *event;
-	struct hlist_node *node;
 	struct hlist_head *head;
 
 	rcu_read_lock();
@@ -5134,7 +5133,7 @@ static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
 	if (!head)
 		goto end;
 
-	hlist_for_each_entry_rcu(event, node, head, hlist_entry) {
+	hlist_for_each_entry_rcu(event, head, hlist_entry) {
 		if (perf_swevent_match(event, type, event_id, data, regs))
 			perf_swevent_event(event, nr, data, regs);
 	}
@@ -5419,7 +5418,6 @@ void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
 {
 	struct perf_sample_data data;
 	struct perf_event *event;
-	struct hlist_node *node;
 
 	struct perf_raw_record raw = {
 		.size = entry_size,
@@ -5429,7 +5427,7 @@ void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
 	perf_sample_data_init(&data, addr, 0);
 	data.raw = &raw;
 
-	hlist_for_each_entry_rcu(event, node, head, hlist_entry) {
+	hlist_for_each_entry_rcu(event, head, hlist_entry) {
 		if (perf_tp_event_match(event, &data, regs))
 			perf_swevent_event(event, count, &data, regs);
 	}
@@ -5965,13 +5963,9 @@ int perf_pmu_register(struct pmu *pmu, char *name, int type)
 	pmu->name = name;
 
 	if (type < 0) {
-		int err = idr_pre_get(&pmu_idr, GFP_KERNEL);
-		if (!err)
-			goto free_pdc;
-
-		err = idr_get_new_above(&pmu_idr, pmu, PERF_TYPE_MAX, &type);
-		if (err) {
-			ret = err;
+		type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL);
+		if (type < 0) {
+			ret = type;
 			goto free_pdc;
 		}
 	}
@@ -6171,11 +6165,14 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
 
 	if (task) {
 		event->attach_state = PERF_ATTACH_TASK;
+
+		if (attr->type == PERF_TYPE_TRACEPOINT)
+			event->hw.tp_target = task;
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 		/*
 		 * hw_breakpoint is a bit difficult here..
 		 */
-		if (attr->type == PERF_TYPE_BREAKPOINT)
+		else if (attr->type == PERF_TYPE_BREAKPOINT)
 			event->hw.bp_target = task;
 #endif
 	}
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index fe8a916507ed..a64f8aeb5c1f 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -676,7 +676,7 @@ int __init init_hw_breakpoint(void)
  err_alloc:
 	for_each_possible_cpu(err_cpu) {
 		for (i = 0; i < TYPE_MAX; i++)
-			kfree(per_cpu(nr_task_bp_pinned[i], cpu));
+			kfree(per_cpu(nr_task_bp_pinned[i], err_cpu));
 		if (err_cpu == cpu)
 			break;
 	}
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index dea7acfbb071..a567c8c7ef31 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -27,6 +27,7 @@
 #include <linux/pagemap.h>	/* read_mapping_page */
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/export.h>
 #include <linux/rmap.h>		/* anon_vma_prepare */
 #include <linux/mmu_notifier.h>	/* set_pte_at_notify */
 #include <linux/swap.h>		/* try_to_free_swap */
@@ -41,58 +42,31 @@
 #define MAX_UPROBE_XOL_SLOTS		UINSNS_PER_PAGE
 
 static struct rb_root uprobes_tree = RB_ROOT;
-
-static DEFINE_SPINLOCK(uprobes_treelock);	/* serialize rbtree access */
-
-#define UPROBES_HASH_SZ	13
-
 /*
- * We need separate register/unregister and mmap/munmap lock hashes because
- * of mmap_sem nesting.
- *
- * uprobe_register() needs to install probes on (potentially) all processes
- * and thus needs to acquire multiple mmap_sems (consequtively, not
- * concurrently), whereas uprobe_mmap() is called while holding mmap_sem
- * for the particular process doing the mmap.
- *
- * uprobe_register()->register_for_each_vma() needs to drop/acquire mmap_sem
- * because of lock order against i_mmap_mutex. This means there's a hole in
- * the register vma iteration where a mmap() can happen.
- *
- * Thus uprobe_register() can race with uprobe_mmap() and we can try and
- * install a probe where one is already installed.
+ * allows us to skip the uprobe_mmap if there are no uprobe events active
+ * at this time.  Probably a fine grained per inode count is better?
  */
+#define no_uprobe_events()	RB_EMPTY_ROOT(&uprobes_tree)
 
-/* serialize (un)register */
-static struct mutex uprobes_mutex[UPROBES_HASH_SZ];
-
-#define uprobes_hash(v)		(&uprobes_mutex[((unsigned long)(v)) % UPROBES_HASH_SZ])
+static DEFINE_SPINLOCK(uprobes_treelock);	/* serialize rbtree access */
 
+#define UPROBES_HASH_SZ	13
 /* serialize uprobe->pending_list */
 static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ];
 #define uprobes_mmap_hash(v)	(&uprobes_mmap_mutex[((unsigned long)(v)) % UPROBES_HASH_SZ])
 
 static struct percpu_rw_semaphore dup_mmap_sem;
 
-/*
- * uprobe_events allows us to skip the uprobe_mmap if there are no uprobe
- * events active at this time.  Probably a fine grained per inode count is
- * better?
- */
-static atomic_t uprobe_events = ATOMIC_INIT(0);
-
 /* Have a copy of original instruction */
 #define UPROBE_COPY_INSN	0
-/* Dont run handlers when first register/ last unregister in progress*/
-#define UPROBE_RUN_HANDLER	1
 /* Can skip singlestep */
-#define UPROBE_SKIP_SSTEP	2
+#define UPROBE_SKIP_SSTEP	1
 
 struct uprobe {
 	struct rb_node		rb_node;	/* node in the rb tree */
 	atomic_t		ref;
+	struct rw_semaphore	register_rwsem;
 	struct rw_semaphore	consumer_rwsem;
-	struct mutex		copy_mutex;	/* TODO: kill me and UPROBE_COPY_INSN */
 	struct list_head	pending_list;
 	struct uprobe_consumer	*consumers;
 	struct inode		*inode;		/* Also hold a ref to inode */
@@ -430,9 +404,6 @@ static struct uprobe *insert_uprobe(struct uprobe *uprobe)
 	u = __insert_uprobe(uprobe);
 	spin_unlock(&uprobes_treelock);
 
-	/* For now assume that the instruction need not be single-stepped */
-	__set_bit(UPROBE_SKIP_SSTEP, &uprobe->flags);
-
 	return u;
 }
 
@@ -452,8 +423,10 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset)
 
 	uprobe->inode = igrab(inode);
 	uprobe->offset = offset;
+	init_rwsem(&uprobe->register_rwsem);
 	init_rwsem(&uprobe->consumer_rwsem);
-	mutex_init(&uprobe->copy_mutex);
+	/* For now assume that the instruction need not be single-stepped */
+	__set_bit(UPROBE_SKIP_SSTEP, &uprobe->flags);
 
 	/* add to uprobes_tree, sorted on inode:offset */
 	cur_uprobe = insert_uprobe(uprobe);
@@ -463,38 +436,17 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset)
 		kfree(uprobe);
 		uprobe = cur_uprobe;
 		iput(inode);
-	} else {
-		atomic_inc(&uprobe_events);
 	}
 
 	return uprobe;
 }
 
-static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs)
-{
-	struct uprobe_consumer *uc;
-
-	if (!test_bit(UPROBE_RUN_HANDLER, &uprobe->flags))
-		return;
-
-	down_read(&uprobe->consumer_rwsem);
-	for (uc = uprobe->consumers; uc; uc = uc->next) {
-		if (!uc->filter || uc->filter(uc, current))
-			uc->handler(uc, regs);
-	}
-	up_read(&uprobe->consumer_rwsem);
-}
-
-/* Returns the previous consumer */
-static struct uprobe_consumer *
-consumer_add(struct uprobe *uprobe, struct uprobe_consumer *uc)
+static void consumer_add(struct uprobe *uprobe, struct uprobe_consumer *uc)
 {
 	down_write(&uprobe->consumer_rwsem);
 	uc->next = uprobe->consumers;
 	uprobe->consumers = uc;
 	up_write(&uprobe->consumer_rwsem);
-
-	return uc->next;
 }
 
 /*
@@ -588,7 +540,8 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file,
 	if (test_bit(UPROBE_COPY_INSN, &uprobe->flags))
 		return ret;
 
-	mutex_lock(&uprobe->copy_mutex);
+	/* TODO: move this into _register, until then we abuse this sem. */
+	down_write(&uprobe->consumer_rwsem);
 	if (test_bit(UPROBE_COPY_INSN, &uprobe->flags))
 		goto out;
 
@@ -612,7 +565,30 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file,
 	set_bit(UPROBE_COPY_INSN, &uprobe->flags);
 
  out:
-	mutex_unlock(&uprobe->copy_mutex);
+	up_write(&uprobe->consumer_rwsem);
+
+	return ret;
+}
+
+static inline bool consumer_filter(struct uprobe_consumer *uc,
+				   enum uprobe_filter_ctx ctx, struct mm_struct *mm)
+{
+	return !uc->filter || uc->filter(uc, ctx, mm);
+}
+
+static bool filter_chain(struct uprobe *uprobe,
+			 enum uprobe_filter_ctx ctx, struct mm_struct *mm)
+{
+	struct uprobe_consumer *uc;
+	bool ret = false;
+
+	down_read(&uprobe->consumer_rwsem);
+	for (uc = uprobe->consumers; uc; uc = uc->next) {
+		ret = consumer_filter(uc, ctx, mm);
+		if (ret)
+			break;
+	}
+	up_read(&uprobe->consumer_rwsem);
 
 	return ret;
 }
@@ -624,16 +600,6 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
 	bool first_uprobe;
 	int ret;
 
-	/*
-	 * If probe is being deleted, unregister thread could be done with
-	 * the vma-rmap-walk through. Adding a probe now can be fatal since
-	 * nobody will be able to cleanup. Also we could be from fork or
-	 * mremap path, where the probe might have already been inserted.
-	 * Hence behave as if probe already existed.
-	 */
-	if (!uprobe->consumers)
-		return 0;
-
 	ret = prepare_uprobe(uprobe, vma->vm_file, mm, vaddr);
 	if (ret)
 		return ret;
@@ -658,14 +624,14 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
 static int
 remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr)
 {
-	/* can happen if uprobe_register() fails */
-	if (!test_bit(MMF_HAS_UPROBES, &mm->flags))
-		return 0;
-
 	set_bit(MMF_RECALC_UPROBES, &mm->flags);
 	return set_orig_insn(&uprobe->arch, mm, vaddr);
 }
 
+static inline bool uprobe_is_active(struct uprobe *uprobe)
+{
+	return !RB_EMPTY_NODE(&uprobe->rb_node);
+}
 /*
  * There could be threads that have already hit the breakpoint. They
  * will recheck the current insn and restart if find_uprobe() fails.
@@ -673,12 +639,15 @@ remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vad
  */
 static void delete_uprobe(struct uprobe *uprobe)
 {
+	if (WARN_ON(!uprobe_is_active(uprobe)))
+		return;
+
 	spin_lock(&uprobes_treelock);
 	rb_erase(&uprobe->rb_node, &uprobes_tree);
 	spin_unlock(&uprobes_treelock);
+	RB_CLEAR_NODE(&uprobe->rb_node); /* for uprobe_is_active() */
 	iput(uprobe->inode);
 	put_uprobe(uprobe);
-	atomic_dec(&uprobe_events);
 }
 
 struct map_info {
@@ -764,8 +733,10 @@ build_map_info(struct address_space *mapping, loff_t offset, bool is_register)
 	return curr;
 }
 
-static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
+static int
+register_for_each_vma(struct uprobe *uprobe, struct uprobe_consumer *new)
 {
+	bool is_register = !!new;
 	struct map_info *info;
 	int err = 0;
 
@@ -794,10 +765,16 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
 		    vaddr_to_offset(vma, info->vaddr) != uprobe->offset)
 			goto unlock;
 
-		if (is_register)
-			err = install_breakpoint(uprobe, mm, vma, info->vaddr);
-		else
-			err |= remove_breakpoint(uprobe, mm, info->vaddr);
+		if (is_register) {
+			/* consult only the "caller", new consumer. */
+			if (consumer_filter(new,
+					UPROBE_FILTER_REGISTER, mm))
+				err = install_breakpoint(uprobe, mm, vma, info->vaddr);
+		} else if (test_bit(MMF_HAS_UPROBES, &mm->flags)) {
+			if (!filter_chain(uprobe,
+					UPROBE_FILTER_UNREGISTER, mm))
+				err |= remove_breakpoint(uprobe, mm, info->vaddr);
+		}
 
  unlock:
 		up_write(&mm->mmap_sem);
@@ -810,17 +787,23 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register)
 	return err;
 }
 
-static int __uprobe_register(struct uprobe *uprobe)
+static int __uprobe_register(struct uprobe *uprobe, struct uprobe_consumer *uc)
 {
-	return register_for_each_vma(uprobe, true);
+	consumer_add(uprobe, uc);
+	return register_for_each_vma(uprobe, uc);
 }
 
-static void __uprobe_unregister(struct uprobe *uprobe)
+static void __uprobe_unregister(struct uprobe *uprobe, struct uprobe_consumer *uc)
 {
-	if (!register_for_each_vma(uprobe, false))
-		delete_uprobe(uprobe);
+	int err;
+
+	if (!consumer_del(uprobe, uc))	/* WARN? */
+		return;
 
+	err = register_for_each_vma(uprobe, NULL);
 	/* TODO : cant unregister? schedule a worker thread */
+	if (!uprobe->consumers && !err)
+		delete_uprobe(uprobe);
 }
 
 /*
@@ -845,31 +828,59 @@ int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *
 	struct uprobe *uprobe;
 	int ret;
 
-	if (!inode || !uc || uc->next)
-		return -EINVAL;
-
+	/* Racy, just to catch the obvious mistakes */
 	if (offset > i_size_read(inode))
 		return -EINVAL;
 
-	ret = 0;
-	mutex_lock(uprobes_hash(inode));
+ retry:
 	uprobe = alloc_uprobe(inode, offset);
-
-	if (!uprobe) {
-		ret = -ENOMEM;
-	} else if (!consumer_add(uprobe, uc)) {
-		ret = __uprobe_register(uprobe);
-		if (ret) {
-			uprobe->consumers = NULL;
-			__uprobe_unregister(uprobe);
-		} else {
-			set_bit(UPROBE_RUN_HANDLER, &uprobe->flags);
-		}
+	if (!uprobe)
+		return -ENOMEM;
+	/*
+	 * We can race with uprobe_unregister()->delete_uprobe().
+	 * Check uprobe_is_active() and retry if it is false.
+	 */
+	down_write(&uprobe->register_rwsem);
+	ret = -EAGAIN;
+	if (likely(uprobe_is_active(uprobe))) {
+		ret = __uprobe_register(uprobe, uc);
+		if (ret)
+			__uprobe_unregister(uprobe, uc);
 	}
+	up_write(&uprobe->register_rwsem);
+	put_uprobe(uprobe);
 
-	mutex_unlock(uprobes_hash(inode));
-	if (uprobe)
-		put_uprobe(uprobe);
+	if (unlikely(ret == -EAGAIN))
+		goto retry;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(uprobe_register);
+
+/*
+ * uprobe_apply - unregister a already registered probe.
+ * @inode: the file in which the probe has to be removed.
+ * @offset: offset from the start of the file.
+ * @uc: consumer which wants to add more or remove some breakpoints
+ * @add: add or remove the breakpoints
+ */
+int uprobe_apply(struct inode *inode, loff_t offset,
+			struct uprobe_consumer *uc, bool add)
+{
+	struct uprobe *uprobe;
+	struct uprobe_consumer *con;
+	int ret = -ENOENT;
+
+	uprobe = find_uprobe(inode, offset);
+	if (!uprobe)
+		return ret;
+
+	down_write(&uprobe->register_rwsem);
+	for (con = uprobe->consumers; con && con != uc ; con = con->next)
+		;
+	if (con)
+		ret = register_for_each_vma(uprobe, add ? uc : NULL);
+	up_write(&uprobe->register_rwsem);
+	put_uprobe(uprobe);
 
 	return ret;
 }
@@ -884,25 +895,42 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume
 {
 	struct uprobe *uprobe;
 
-	if (!inode || !uc)
-		return;
-
 	uprobe = find_uprobe(inode, offset);
 	if (!uprobe)
 		return;
 
-	mutex_lock(uprobes_hash(inode));
+	down_write(&uprobe->register_rwsem);
+	__uprobe_unregister(uprobe, uc);
+	up_write(&uprobe->register_rwsem);
+	put_uprobe(uprobe);
+}
+EXPORT_SYMBOL_GPL(uprobe_unregister);
 
-	if (consumer_del(uprobe, uc)) {
-		if (!uprobe->consumers) {
-			__uprobe_unregister(uprobe);
-			clear_bit(UPROBE_RUN_HANDLER, &uprobe->flags);
-		}
+static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm)
+{
+	struct vm_area_struct *vma;
+	int err = 0;
+
+	down_read(&mm->mmap_sem);
+	for (vma = mm->mmap; vma; vma = vma->vm_next) {
+		unsigned long vaddr;
+		loff_t offset;
+
+		if (!valid_vma(vma, false) ||
+		    vma->vm_file->f_mapping->host != uprobe->inode)
+			continue;
+
+		offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
+		if (uprobe->offset <  offset ||
+		    uprobe->offset >= offset + vma->vm_end - vma->vm_start)
+			continue;
+
+		vaddr = offset_to_vaddr(vma, uprobe->offset);
+		err |= remove_breakpoint(uprobe, mm, vaddr);
 	}
+	up_read(&mm->mmap_sem);
 
-	mutex_unlock(uprobes_hash(inode));
-	if (uprobe)
-		put_uprobe(uprobe);
+	return err;
 }
 
 static struct rb_node *
@@ -979,7 +1007,7 @@ int uprobe_mmap(struct vm_area_struct *vma)
 	struct uprobe *uprobe, *u;
 	struct inode *inode;
 
-	if (!atomic_read(&uprobe_events) || !valid_vma(vma, true))
+	if (no_uprobe_events() || !valid_vma(vma, true))
 		return 0;
 
 	inode = vma->vm_file->f_mapping->host;
@@ -988,9 +1016,14 @@ int uprobe_mmap(struct vm_area_struct *vma)
 
 	mutex_lock(uprobes_mmap_hash(inode));
 	build_probe_list(inode, vma, vma->vm_start, vma->vm_end, &tmp_list);
-
+	/*
+	 * We can race with uprobe_unregister(), this uprobe can be already
+	 * removed. But in this case filter_chain() must return false, all
+	 * consumers have gone away.
+	 */
 	list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) {
-		if (!fatal_signal_pending(current)) {
+		if (!fatal_signal_pending(current) &&
+		    filter_chain(uprobe, UPROBE_FILTER_MMAP, vma->vm_mm)) {
 			unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset);
 			install_breakpoint(uprobe, vma->vm_mm, vma, vaddr);
 		}
@@ -1025,7 +1058,7 @@ vma_has_uprobes(struct vm_area_struct *vma, unsigned long start, unsigned long e
  */
 void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end)
 {
-	if (!atomic_read(&uprobe_events) || !valid_vma(vma, false))
+	if (no_uprobe_events() || !valid_vma(vma, false))
 		return;
 
 	if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */
@@ -1042,22 +1075,14 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon
 /* Slot allocation for XOL */
 static int xol_add_vma(struct xol_area *area)
 {
-	struct mm_struct *mm;
-	int ret;
-
-	area->page = alloc_page(GFP_HIGHUSER);
-	if (!area->page)
-		return -ENOMEM;
-
-	ret = -EALREADY;
-	mm = current->mm;
+	struct mm_struct *mm = current->mm;
+	int ret = -EALREADY;
 
 	down_write(&mm->mmap_sem);
 	if (mm->uprobes_state.xol_area)
 		goto fail;
 
 	ret = -ENOMEM;
-
 	/* Try to map as high as possible, this is only a hint. */
 	area->vaddr = get_unmapped_area(NULL, TASK_SIZE - PAGE_SIZE, PAGE_SIZE, 0, 0);
 	if (area->vaddr & ~PAGE_MASK) {
@@ -1073,54 +1098,53 @@ static int xol_add_vma(struct xol_area *area)
 	smp_wmb();	/* pairs with get_xol_area() */
 	mm->uprobes_state.xol_area = area;
 	ret = 0;
-
-fail:
+ fail:
 	up_write(&mm->mmap_sem);
-	if (ret)
-		__free_page(area->page);
 
 	return ret;
 }
 
-static struct xol_area *get_xol_area(struct mm_struct *mm)
-{
-	struct xol_area *area;
-
-	area = mm->uprobes_state.xol_area;
-	smp_read_barrier_depends();	/* pairs with wmb in xol_add_vma() */
-
-	return area;
-}
-
 /*
- * xol_alloc_area - Allocate process's xol_area.
- * This area will be used for storing instructions for execution out of
- * line.
+ * get_xol_area - Allocate process's xol_area if necessary.
+ * This area will be used for storing instructions for execution out of line.
  *
  * Returns the allocated area or NULL.
  */
-static struct xol_area *xol_alloc_area(void)
+static struct xol_area *get_xol_area(void)
 {
+	struct mm_struct *mm = current->mm;
 	struct xol_area *area;
 
+	area = mm->uprobes_state.xol_area;
+	if (area)
+		goto ret;
+
 	area = kzalloc(sizeof(*area), GFP_KERNEL);
 	if (unlikely(!area))
-		return NULL;
+		goto out;
 
 	area->bitmap = kzalloc(BITS_TO_LONGS(UINSNS_PER_PAGE) * sizeof(long), GFP_KERNEL);
-
 	if (!area->bitmap)
-		goto fail;
+		goto free_area;
+
+	area->page = alloc_page(GFP_HIGHUSER);
+	if (!area->page)
+		goto free_bitmap;
 
 	init_waitqueue_head(&area->wq);
 	if (!xol_add_vma(area))
 		return area;
 
-fail:
+	__free_page(area->page);
+ free_bitmap:
 	kfree(area->bitmap);
+ free_area:
 	kfree(area);
-
-	return get_xol_area(current->mm);
+ out:
+	area = mm->uprobes_state.xol_area;
+ ret:
+	smp_read_barrier_depends();     /* pairs with wmb in xol_add_vma() */
+	return area;
 }
 
 /*
@@ -1186,33 +1210,26 @@ static unsigned long xol_take_insn_slot(struct xol_area *area)
 }
 
 /*
- * xol_get_insn_slot - If was not allocated a slot, then
- * allocate a slot.
+ * xol_get_insn_slot - allocate a slot for xol.
  * Returns the allocated slot address or 0.
  */
-static unsigned long xol_get_insn_slot(struct uprobe *uprobe, unsigned long slot_addr)
+static unsigned long xol_get_insn_slot(struct uprobe *uprobe)
 {
 	struct xol_area *area;
 	unsigned long offset;
+	unsigned long xol_vaddr;
 	void *vaddr;
 
-	area = get_xol_area(current->mm);
-	if (!area) {
-		area = xol_alloc_area();
-		if (!area)
-			return 0;
-	}
-	current->utask->xol_vaddr = xol_take_insn_slot(area);
+	area = get_xol_area();
+	if (!area)
+		return 0;
 
-	/*
-	 * Initialize the slot if xol_vaddr points to valid
-	 * instruction slot.
-	 */
-	if (unlikely(!current->utask->xol_vaddr))
+	xol_vaddr = xol_take_insn_slot(area);
+	if (unlikely(!xol_vaddr))
 		return 0;
 
-	current->utask->vaddr = slot_addr;
-	offset = current->utask->xol_vaddr & ~PAGE_MASK;
+	/* Initialize the slot */
+	offset = xol_vaddr & ~PAGE_MASK;
 	vaddr = kmap_atomic(area->page);
 	memcpy(vaddr + offset, uprobe->arch.insn, MAX_UINSN_BYTES);
 	kunmap_atomic(vaddr);
@@ -1222,7 +1239,7 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe, unsigned long slot
 	 */
 	flush_dcache_page(area->page);
 
-	return current->utask->xol_vaddr;
+	return xol_vaddr;
 }
 
 /*
@@ -1240,8 +1257,7 @@ static void xol_free_insn_slot(struct task_struct *tsk)
 		return;
 
 	slot_addr = tsk->utask->xol_vaddr;
-
-	if (unlikely(!slot_addr || IS_ERR_VALUE(slot_addr)))
+	if (unlikely(!slot_addr))
 		return;
 
 	area = tsk->mm->uprobes_state.xol_area;
@@ -1303,33 +1319,48 @@ void uprobe_copy_process(struct task_struct *t)
 }
 
 /*
- * Allocate a uprobe_task object for the task.
- * Called when the thread hits a breakpoint for the first time.
+ * Allocate a uprobe_task object for the task if if necessary.
+ * Called when the thread hits a breakpoint.
  *
  * Returns:
  * - pointer to new uprobe_task on success
  * - NULL otherwise
  */
-static struct uprobe_task *add_utask(void)
+static struct uprobe_task *get_utask(void)
 {
-	struct uprobe_task *utask;
-
-	utask = kzalloc(sizeof *utask, GFP_KERNEL);
-	if (unlikely(!utask))
-		return NULL;
-
-	current->utask = utask;
-	return utask;
+	if (!current->utask)
+		current->utask = kzalloc(sizeof(struct uprobe_task), GFP_KERNEL);
+	return current->utask;
 }
 
 /* Prepare to single-step probed instruction out of line. */
 static int
-pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long vaddr)
+pre_ssout(struct uprobe *uprobe, struct pt_regs *regs, unsigned long bp_vaddr)
 {
-	if (xol_get_insn_slot(uprobe, vaddr) && !arch_uprobe_pre_xol(&uprobe->arch, regs))
-		return 0;
+	struct uprobe_task *utask;
+	unsigned long xol_vaddr;
+	int err;
+
+	utask = get_utask();
+	if (!utask)
+		return -ENOMEM;
+
+	xol_vaddr = xol_get_insn_slot(uprobe);
+	if (!xol_vaddr)
+		return -ENOMEM;
+
+	utask->xol_vaddr = xol_vaddr;
+	utask->vaddr = bp_vaddr;
+
+	err = arch_uprobe_pre_xol(&uprobe->arch, regs);
+	if (unlikely(err)) {
+		xol_free_insn_slot(current);
+		return err;
+	}
 
-	return -EFAULT;
+	utask->active_uprobe = uprobe;
+	utask->state = UTASK_SSTEP;
+	return 0;
 }
 
 /*
@@ -1391,6 +1422,7 @@ static void mmf_recalc_uprobes(struct mm_struct *mm)
 		 * This is not strictly accurate, we can race with
 		 * uprobe_unregister() and see the already removed
 		 * uprobe if delete_uprobe() was not yet called.
+		 * Or this uprobe can be filtered out.
 		 */
 		if (vma_has_uprobes(vma, vma->vm_start, vma->vm_end))
 			return;
@@ -1452,13 +1484,33 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
 	return uprobe;
 }
 
+static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs)
+{
+	struct uprobe_consumer *uc;
+	int remove = UPROBE_HANDLER_REMOVE;
+
+	down_read(&uprobe->register_rwsem);
+	for (uc = uprobe->consumers; uc; uc = uc->next) {
+		int rc = uc->handler(uc, regs);
+
+		WARN(rc & ~UPROBE_HANDLER_MASK,
+			"bad rc=0x%x from %pf()\n", rc, uc->handler);
+		remove &= rc;
+	}
+
+	if (remove && uprobe->consumers) {
+		WARN_ON(!uprobe_is_active(uprobe));
+		unapply_uprobe(uprobe, current->mm);
+	}
+	up_read(&uprobe->register_rwsem);
+}
+
 /*
  * Run handler and ask thread to singlestep.
  * Ensure all non-fatal signals cannot interrupt thread while it singlesteps.
  */
 static void handle_swbp(struct pt_regs *regs)
 {
-	struct uprobe_task *utask;
 	struct uprobe *uprobe;
 	unsigned long bp_vaddr;
 	int uninitialized_var(is_swbp);
@@ -1483,6 +1535,10 @@ static void handle_swbp(struct pt_regs *regs)
 		}
 		return;
 	}
+
+	/* change it in advance for ->handler() and restart */
+	instruction_pointer_set(regs, bp_vaddr);
+
 	/*
 	 * TODO: move copy_insn/etc into _register and remove this hack.
 	 * After we hit the bp, _unregister + _register can install the
@@ -1490,32 +1546,16 @@ static void handle_swbp(struct pt_regs *regs)
 	 */
 	smp_rmb(); /* pairs with wmb() in install_breakpoint() */
 	if (unlikely(!test_bit(UPROBE_COPY_INSN, &uprobe->flags)))
-		goto restart;
-
-	utask = current->utask;
-	if (!utask) {
-		utask = add_utask();
-		/* Cannot allocate; re-execute the instruction. */
-		if (!utask)
-			goto restart;
-	}
+		goto out;
 
 	handler_chain(uprobe, regs);
 	if (can_skip_sstep(uprobe, regs))
 		goto out;
 
-	if (!pre_ssout(uprobe, regs, bp_vaddr)) {
-		utask->active_uprobe = uprobe;
-		utask->state = UTASK_SSTEP;
+	if (!pre_ssout(uprobe, regs, bp_vaddr))
 		return;
-	}
 
-restart:
-	/*
-	 * cannot singlestep; cannot skip instruction;
-	 * re-execute the instruction.
-	 */
-	instruction_pointer_set(regs, bp_vaddr);
+	/* can_skip_sstep() succeeded, or restart if can't singlestep */
 out:
 	put_uprobe(uprobe);
 }
@@ -1609,10 +1649,8 @@ static int __init init_uprobes(void)
 {
 	int i;
 
-	for (i = 0; i < UPROBES_HASH_SZ; i++) {
-		mutex_init(&uprobes_mutex[i]);
+	for (i = 0; i < UPROBES_HASH_SZ; i++)
 		mutex_init(&uprobes_mmap_mutex[i]);
-	}
 
 	if (percpu_init_rwsem(&dup_mmap_sem))
 		return -ENOMEM;
diff --git a/kernel/exit.c b/kernel/exit.c
index b4df21937216..51e485ca9935 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -20,6 +20,7 @@
 #include <linux/tsacct_kern.h>
 #include <linux/file.h>
 #include <linux/fdtable.h>
+#include <linux/freezer.h>
 #include <linux/binfmts.h>
 #include <linux/nsproxy.h>
 #include <linux/pid_namespace.h>
@@ -31,7 +32,6 @@
 #include <linux/mempolicy.h>
 #include <linux/taskstats_kern.h>
 #include <linux/delayacct.h>
-#include <linux/freezer.h>
 #include <linux/cgroup.h>
 #include <linux/syscalls.h>
 #include <linux/signal.h>
@@ -85,6 +85,7 @@ static void __exit_signal(struct task_struct *tsk)
 	bool group_dead = thread_group_leader(tsk);
 	struct sighand_struct *sighand;
 	struct tty_struct *uninitialized_var(tty);
+	cputime_t utime, stime;
 
 	sighand = rcu_dereference_check(tsk->sighand,
 					lockdep_tasklist_lock_is_held());
@@ -123,9 +124,10 @@ static void __exit_signal(struct task_struct *tsk)
 		 * We won't ever get here for the group leader, since it
 		 * will have been the last reference on the signal_struct.
 		 */
-		sig->utime += tsk->utime;
-		sig->stime += tsk->stime;
-		sig->gtime += tsk->gtime;
+		task_cputime(tsk, &utime, &stime);
+		sig->utime += utime;
+		sig->stime += stime;
+		sig->gtime += task_gtime(tsk);
 		sig->min_flt += tsk->min_flt;
 		sig->maj_flt += tsk->maj_flt;
 		sig->nvcsw += tsk->nvcsw;
@@ -483,7 +485,7 @@ static void exit_mm(struct task_struct * tsk)
 			set_task_state(tsk, TASK_UNINTERRUPTIBLE);
 			if (!self.task) /* see coredump_finish() */
 				break;
-			schedule();
+			freezable_schedule();
 		}
 		__set_task_state(tsk, TASK_RUNNING);
 		down_read(&mm->mmap_sem);
@@ -833,7 +835,7 @@ void do_exit(long code)
 	/*
 	 * Make sure we are holding no locks:
 	 */
-	debug_check_no_locks_held(tsk);
+	debug_check_no_locks_held();
 	/*
 	 * We can do this unlocked here. The futex code uses this flag
 	 * just to verify whether the pi state cleanup has been done
@@ -1092,7 +1094,7 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
 		sig = p->signal;
 		psig->cutime += tgutime + sig->cutime;
 		psig->cstime += tgstime + sig->cstime;
-		psig->cgtime += p->gtime + sig->gtime + sig->cgtime;
+		psig->cgtime += task_gtime(p) + sig->gtime + sig->cgtime;
 		psig->cmin_flt +=
 			p->min_flt + sig->min_flt + sig->cmin_flt;
 		psig->cmaj_flt +=
diff --git a/kernel/fork.c b/kernel/fork.c
index c535f33bbb9c..1766d324d5e3 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -413,7 +413,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
 		tmp->vm_next = tmp->vm_prev = NULL;
 		file = tmp->vm_file;
 		if (file) {
-			struct inode *inode = file->f_path.dentry->d_inode;
+			struct inode *inode = file_inode(file);
 			struct address_space *mapping = file->f_mapping;
 
 			get_file(file);
@@ -1141,6 +1141,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
 		return ERR_PTR(-EINVAL);
 
+	if ((clone_flags & (CLONE_NEWUSER|CLONE_FS)) == (CLONE_NEWUSER|CLONE_FS))
+		return ERR_PTR(-EINVAL);
+
 	/*
 	 * Thread groups must share signals as well, and detached threads
 	 * can only be started up within the thread group.
@@ -1233,6 +1236,12 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
 	p->prev_cputime.utime = p->prev_cputime.stime = 0;
 #endif
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+	seqlock_init(&p->vtime_seqlock);
+	p->vtime_snap = 0;
+	p->vtime_snap_whence = VTIME_SLEEPING;
+#endif
+
 #if defined(SPLIT_RSS_COUNTING)
 	memset(&p->rss_stat, 0, sizeof(p->rss_stat));
 #endif
@@ -1801,7 +1810,7 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
 	 * If unsharing a user namespace must also unshare the thread.
 	 */
 	if (unshare_flags & CLONE_NEWUSER)
-		unshare_flags |= CLONE_THREAD;
+		unshare_flags |= CLONE_THREAD | CLONE_FS;
 	/*
 	 * If unsharing a pid namespace must also unshare the thread.
 	 */
@@ -1855,10 +1864,8 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
 			exit_sem(current);
 		}
 
-		if (new_nsproxy) {
+		if (new_nsproxy)
 			switch_task_namespaces(current, new_nsproxy);
-			new_nsproxy = NULL;
-		}
 
 		task_lock(current);
 
@@ -1888,9 +1895,6 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
 		}
 	}
 
-	if (new_nsproxy)
-		put_nsproxy(new_nsproxy);
-
 bad_unshare_cleanup_cred:
 	if (new_cred)
 		put_cred(new_cred);
diff --git a/kernel/futex.c b/kernel/futex.c
index 19eb089ca003..b26dcfc02c94 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -60,6 +60,7 @@
 #include <linux/pid.h>
 #include <linux/nsproxy.h>
 #include <linux/ptrace.h>
+#include <linux/sched/rt.h>
 
 #include <asm/futex.h>
 
@@ -222,10 +223,11 @@ static void drop_futex_key_refs(union futex_key *key)
  * @rw:		mapping needs to be read/write (values: VERIFY_READ,
  *              VERIFY_WRITE)
  *
- * Returns a negative error code or 0
+ * Return: a negative error code or 0
+ *
  * The key words are stored in *key on success.
  *
- * For shared mappings, it's (page->index, vma->vm_file->f_path.dentry->d_inode,
+ * For shared mappings, it's (page->index, file_inode(vma->vm_file),
  * offset_within_page).  For private mappings, it's (uaddr, current->mm).
  * We can usually work out the index without swapping in the page.
  *
@@ -704,9 +706,9 @@ lookup_pi_state(u32 uval, struct futex_hash_bucket *hb,
  *			be "current" except in the case of requeue pi.
  * @set_waiters:	force setting the FUTEX_WAITERS bit (1) or not (0)
  *
- * Returns:
- *  0 - ready to wait
- *  1 - acquired the lock
+ * Return:
+ *  0 - ready to wait;
+ *  1 - acquired the lock;
  * <0 - error
  *
  * The hb->lock and futex_key refs shall be held by the caller.
@@ -1190,9 +1192,9 @@ void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key,
  * then direct futex_lock_pi_atomic() to force setting the FUTEX_WAITERS bit.
  * hb1 and hb2 must be held by the caller.
  *
- * Returns:
- *  0 - failed to acquire the lock atomicly
- *  1 - acquired the lock
+ * Return:
+ *  0 - failed to acquire the lock atomically;
+ *  1 - acquired the lock;
  * <0 - error
  */
 static int futex_proxy_trylock_atomic(u32 __user *pifutex,
@@ -1253,8 +1255,8 @@ static int futex_proxy_trylock_atomic(u32 __user *pifutex,
  * Requeue waiters on uaddr1 to uaddr2. In the requeue_pi case, try to acquire
  * uaddr2 atomically on behalf of the top waiter.
  *
- * Returns:
- * >=0 - on success, the number of tasks requeued or woken
+ * Return:
+ * >=0 - on success, the number of tasks requeued or woken;
  *  <0 - on error
  */
 static int futex_requeue(u32 __user *uaddr1, unsigned int flags,
@@ -1535,8 +1537,8 @@ static inline void queue_me(struct futex_q *q, struct futex_hash_bucket *hb)
  * The q->lock_ptr must not be held by the caller. A call to unqueue_me() must
  * be paired with exactly one earlier call to queue_me().
  *
- * Returns:
- *   1 - if the futex_q was still queued (and we removed unqueued it)
+ * Return:
+ *   1 - if the futex_q was still queued (and we removed unqueued it);
  *   0 - if the futex_q was already removed by the waking thread
  */
 static int unqueue_me(struct futex_q *q)
@@ -1706,9 +1708,9 @@ static long futex_wait_restart(struct restart_block *restart);
  * the pi_state owner as well as handle race conditions that may allow us to
  * acquire the lock. Must be called with the hb lock held.
  *
- * Returns:
- *  1 - success, lock taken
- *  0 - success, lock not taken
+ * Return:
+ *  1 - success, lock taken;
+ *  0 - success, lock not taken;
  * <0 - on error (-EFAULT)
  */
 static int fixup_owner(u32 __user *uaddr, struct futex_q *q, int locked)
@@ -1823,8 +1825,8 @@ static void futex_wait_queue_me(struct futex_hash_bucket *hb, struct futex_q *q,
  * Return with the hb lock held and a q.key reference on success, and unlocked
  * with no q.key reference on failure.
  *
- * Returns:
- *  0 - uaddr contains val and hb has been locked
+ * Return:
+ *  0 - uaddr contains val and hb has been locked;
  * <1 - -EFAULT or -EWOULDBLOCK (uaddr does not contain val) and hb is unlocked
  */
 static int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
@@ -2202,9 +2204,9 @@ pi_faulted:
  * the wakeup and return the appropriate error code to the caller.  Must be
  * called with the hb lock held.
  *
- * Returns
- *  0 - no early wakeup detected
- * <0 - -ETIMEDOUT or -ERESTARTNOINTR
+ * Return:
+ *  0 = no early wakeup detected;
+ * <0 = -ETIMEDOUT or -ERESTARTNOINTR
  */
 static inline
 int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
@@ -2246,7 +2248,6 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
  * @val:	the expected value of uaddr
  * @abs_time:	absolute timeout
  * @bitset:	32 bit wakeup bitset set by userspace, defaults to all
- * @clockrt:	whether to use CLOCK_REALTIME (1) or CLOCK_MONOTONIC (0)
  * @uaddr2:	the pi futex we will take prior to returning to user-space
  *
  * The caller will wait on uaddr and will be requeued by futex_requeue() to
@@ -2257,7 +2258,7 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
  * there was a need to.
  *
  * We call schedule in futex_wait_queue_me() when we enqueue and return there
- * via the following:
+ * via the following--
  * 1) wakeup on uaddr2 after an atomic lock acquisition by futex_requeue()
  * 2) wakeup on uaddr2 after a requeue
  * 3) signal
@@ -2275,8 +2276,8 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
  *
  * If 4 or 7, we cleanup and return with -ETIMEDOUT.
  *
- * Returns:
- *  0 - On success
+ * Return:
+ *  0 - On success;
  * <0 - On error
  */
 static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
@@ -2471,8 +2472,6 @@ SYSCALL_DEFINE3(get_robust_list, int, pid,
 	if (!futex_cmpxchg_enabled)
 		return -ENOSYS;
 
-	WARN_ONCE(1, "deprecated: get_robust_list will be deleted in 2013.\n");
-
 	rcu_read_lock();
 
 	ret = -ESRCH;
diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index 83e368b005fc..f9f44fd4d34d 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -11,6 +11,7 @@
 #include <linux/nsproxy.h>
 #include <linux/futex.h>
 #include <linux/ptrace.h>
+#include <linux/syscalls.h>
 
 #include <asm/uaccess.h>
 
@@ -116,9 +117,9 @@ void compat_exit_robust_list(struct task_struct *curr)
 	}
 }
 
-asmlinkage long
-compat_sys_set_robust_list(struct compat_robust_list_head __user *head,
-			   compat_size_t len)
+COMPAT_SYSCALL_DEFINE2(set_robust_list,
+		struct compat_robust_list_head __user *, head,
+		compat_size_t, len)
 {
 	if (!futex_cmpxchg_enabled)
 		return -ENOSYS;
@@ -131,9 +132,9 @@ compat_sys_set_robust_list(struct compat_robust_list_head __user *head,
 	return 0;
 }
 
-asmlinkage long
-compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
-			   compat_size_t __user *len_ptr)
+COMPAT_SYSCALL_DEFINE3(get_robust_list, int, pid,
+			compat_uptr_t __user *, head_ptr,
+			compat_size_t __user *, len_ptr)
 {
 	struct compat_robust_list_head __user *head;
 	unsigned long ret;
@@ -142,8 +143,6 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
 	if (!futex_cmpxchg_enabled)
 		return -ENOSYS;
 
-	WARN_ONCE(1, "deprecated: get_robust_list will be deleted in 2013.\n");
-
 	rcu_read_lock();
 
 	ret = -ESRCH;
@@ -172,9 +171,9 @@ err_unlock:
 	return ret;
 }
 
-asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
-		struct compat_timespec __user *utime, u32 __user *uaddr2,
-		u32 val3)
+COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
+		struct compat_timespec __user *, utime, u32 __user *, uaddr2,
+		u32, val3)
 {
 	struct timespec ts;
 	ktime_t t, *tp = NULL;
diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
index a92028196cc1..d4da55d1fb65 100644
--- a/kernel/gcov/Kconfig
+++ b/kernel/gcov/Kconfig
@@ -35,7 +35,7 @@ config GCOV_KERNEL
 config GCOV_PROFILE_ALL
 	bool "Profile entire Kernel"
 	depends on GCOV_KERNEL
-	depends on SUPERH || S390 || X86 || (PPC && EXPERIMENTAL) || MICROBLAZE
+	depends on SUPERH || S390 || X86 || PPC || MICROBLAZE
 	default n
 	---help---
 	This options activates profiling for the entire kernel.
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 6db7a5ed52b5..cc47812d3feb 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -44,6 +44,8 @@
 #include <linux/err.h>
 #include <linux/debugobjects.h>
 #include <linux/sched.h>
+#include <linux/sched/sysctl.h>
+#include <linux/sched/rt.h>
 #include <linux/timer.h>
 
 #include <asm/uaccess.h>
@@ -640,21 +642,9 @@ static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
  * and expiry check is done in the hrtimer_interrupt or in the softirq.
  */
 static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
-					    struct hrtimer_clock_base *base,
-					    int wakeup)
+					    struct hrtimer_clock_base *base)
 {
-	if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
-		if (wakeup) {
-			raw_spin_unlock(&base->cpu_base->lock);
-			raise_softirq_irqoff(HRTIMER_SOFTIRQ);
-			raw_spin_lock(&base->cpu_base->lock);
-		} else
-			__raise_softirq_irqoff(HRTIMER_SOFTIRQ);
-
-		return 1;
-	}
-
-	return 0;
+	return base->cpu_base->hres_active && hrtimer_reprogram(timer, base);
 }
 
 static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
@@ -735,8 +725,7 @@ static inline int hrtimer_switch_to_hres(void) { return 0; }
 static inline void
 hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
 static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
-					    struct hrtimer_clock_base *base,
-					    int wakeup)
+					    struct hrtimer_clock_base *base)
 {
 	return 0;
 }
@@ -995,8 +984,21 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 	 *
 	 * XXX send_remote_softirq() ?
 	 */
-	if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases))
-		hrtimer_enqueue_reprogram(timer, new_base, wakeup);
+	if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)
+		&& hrtimer_enqueue_reprogram(timer, new_base)) {
+		if (wakeup) {
+			/*
+			 * We need to drop cpu_base->lock to avoid a
+			 * lock ordering issue vs. rq->lock.
+			 */
+			raw_spin_unlock(&new_base->cpu_base->lock);
+			raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+			local_irq_restore(flags);
+			return ret;
+		} else {
+			__raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+		}
+	}
 
 	unlock_hrtimer_base(timer, &flags);
 
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 3aca9f29d30e..cbd97ce0b000 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -90,27 +90,41 @@ int irq_set_handler_data(unsigned int irq, void *data)
 EXPORT_SYMBOL(irq_set_handler_data);
 
 /**
- *	irq_set_msi_desc - set MSI descriptor data for an irq
- *	@irq:	Interrupt number
- *	@entry:	Pointer to MSI descriptor data
+ *	irq_set_msi_desc_off - set MSI descriptor data for an irq at offset
+ *	@irq_base:	Interrupt number base
+ *	@irq_offset:	Interrupt number offset
+ *	@entry:		Pointer to MSI descriptor data
  *
- *	Set the MSI descriptor entry for an irq
+ *	Set the MSI descriptor entry for an irq at offset
  */
-int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
+int irq_set_msi_desc_off(unsigned int irq_base, unsigned int irq_offset,
+			 struct msi_desc *entry)
 {
 	unsigned long flags;
-	struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
+	struct irq_desc *desc = irq_get_desc_lock(irq_base + irq_offset, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
 
 	if (!desc)
 		return -EINVAL;
 	desc->irq_data.msi_desc = entry;
-	if (entry)
-		entry->irq = irq;
+	if (entry && !irq_offset)
+		entry->irq = irq_base;
 	irq_put_desc_unlock(desc, flags);
 	return 0;
 }
 
 /**
+ *	irq_set_msi_desc - set MSI descriptor data for an irq
+ *	@irq:	Interrupt number
+ *	@entry:	Pointer to MSI descriptor data
+ *
+ *	Set the MSI descriptor entry for an irq
+ */
+int irq_set_msi_desc(unsigned int irq, struct msi_desc *entry)
+{
+	return irq_set_msi_desc_off(irq, 0, entry);
+}
+
+/**
  *	irq_set_chip_data - set irq chip data for an irq
  *	@irq:	Interrupt number
  *	@data:	Pointer to chip specific data
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index e49a288fa479..fa17855ca65a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -16,6 +16,7 @@
 #include <linux/interrupt.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/sched/rt.h>
 #include <linux/task_work.h>
 
 #include "internals.h"
@@ -1524,6 +1525,7 @@ void enable_percpu_irq(unsigned int irq, unsigned int type)
 out:
 	irq_put_desc_unlock(desc, flags);
 }
+EXPORT_SYMBOL_GPL(enable_percpu_irq);
 
 void disable_percpu_irq(unsigned int irq)
 {
@@ -1537,6 +1539,7 @@ void disable_percpu_irq(unsigned int irq)
 	irq_percpu_disable(desc, cpu);
 	irq_put_desc_unlock(desc, flags);
 }
+EXPORT_SYMBOL_GPL(disable_percpu_irq);
 
 /*
  * Internal function to unregister a percpu irqaction.
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 4bd4faa6323a..397db02209ed 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -76,7 +76,7 @@ static int irq_affinity_list_proc_show(struct seq_file *m, void *v)
 static ssize_t write_irq_affinity(int type, struct file *file,
 		const char __user *buffer, size_t count, loff_t *pos)
 {
-	unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data;
+	unsigned int irq = (int)(long)PDE(file_inode(file))->data;
 	cpumask_var_t new_value;
 	int err;
 
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 611cd6003c45..7b5f012bde9d 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -80,13 +80,11 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force)
 
 	/*
 	 * All handlers must agree on IRQF_SHARED, so we test just the
-	 * first. Check for action->next as well.
+	 * first.
 	 */
 	action = desc->action;
 	if (!action || !(action->flags & IRQF_SHARED) ||
-	    (action->flags & __IRQF_TIMER) ||
-	    (action->handler(irq, action->dev_id) == IRQ_HANDLED) ||
-	    !action->next)
+	    (action->flags & __IRQF_TIMER))
 		goto out;
 
 	/* Already running on another processor */
@@ -104,6 +102,7 @@ static int try_one_irq(int irq, struct irq_desc *desc, bool force)
 	do {
 		if (handle_irq_event(desc) == IRQ_HANDLED)
 			ret = IRQ_HANDLED;
+		/* Make sure that there is still a valid action */
 		action = desc->action;
 	} while ((desc->istate & IRQS_PENDING) && action);
 	desc->istate &= ~IRQS_POLL_INPROGRESS;
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 1588e3b2871b..55fcce6065cf 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -12,37 +12,36 @@
 #include <linux/percpu.h>
 #include <linux/hardirq.h>
 #include <linux/irqflags.h>
+#include <linux/sched.h>
+#include <linux/tick.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
 #include <asm/processor.h>
 
-/*
- * An entry can be in one of four states:
- *
- * free	     NULL, 0 -> {claimed}       : free to be used
- * claimed   NULL, 3 -> {pending}       : claimed to be enqueued
- * pending   next, 3 -> {busy}          : queued, pending callback
- * busy      NULL, 2 -> {free, claimed} : callback in progress, can be claimed
- */
-
-#define IRQ_WORK_PENDING	1UL
-#define IRQ_WORK_BUSY		2UL
-#define IRQ_WORK_FLAGS		3UL
 
 static DEFINE_PER_CPU(struct llist_head, irq_work_list);
+static DEFINE_PER_CPU(int, irq_work_raised);
 
 /*
  * Claim the entry so that no one else will poke at it.
  */
 static bool irq_work_claim(struct irq_work *work)
 {
-	unsigned long flags, nflags;
+	unsigned long flags, oflags, nflags;
 
+	/*
+	 * Start with our best wish as a premise but only trust any
+	 * flag value after cmpxchg() result.
+	 */
+	flags = work->flags & ~IRQ_WORK_PENDING;
 	for (;;) {
-		flags = work->flags;
-		if (flags & IRQ_WORK_PENDING)
-			return false;
 		nflags = flags | IRQ_WORK_FLAGS;
-		if (cmpxchg(&work->flags, flags, nflags) == flags)
+		oflags = cmpxchg(&work->flags, flags, nflags);
+		if (oflags == flags)
 			break;
+		if (oflags & IRQ_WORK_PENDING)
+			return false;
+		flags = oflags;
 		cpu_relax();
 	}
 
@@ -57,57 +56,69 @@ void __weak arch_irq_work_raise(void)
 }
 
 /*
- * Queue the entry and raise the IPI if needed.
+ * Enqueue the irq_work @entry unless it's already pending
+ * somewhere.
+ *
+ * Can be re-enqueued while the callback is still in progress.
  */
-static void __irq_work_queue(struct irq_work *work)
+void irq_work_queue(struct irq_work *work)
 {
-	bool empty;
+	/* Only queue if not already pending */
+	if (!irq_work_claim(work))
+		return;
 
+	/* Queue the entry and raise the IPI if needed. */
 	preempt_disable();
 
-	empty = llist_add(&work->llnode, &__get_cpu_var(irq_work_list));
-	/* The list was empty, raise self-interrupt to start processing. */
-	if (empty)
-		arch_irq_work_raise();
+	llist_add(&work->llnode, &__get_cpu_var(irq_work_list));
+
+	/*
+	 * If the work is not "lazy" or the tick is stopped, raise the irq
+	 * work interrupt (if supported by the arch), otherwise, just wait
+	 * for the next tick.
+	 */
+	if (!(work->flags & IRQ_WORK_LAZY) || tick_nohz_tick_stopped()) {
+		if (!this_cpu_cmpxchg(irq_work_raised, 0, 1))
+			arch_irq_work_raise();
+	}
 
 	preempt_enable();
 }
+EXPORT_SYMBOL_GPL(irq_work_queue);
 
-/*
- * Enqueue the irq_work @entry, returns true on success, failure when the
- * @entry was already enqueued by someone else.
- *
- * Can be re-enqueued while the callback is still in progress.
- */
-bool irq_work_queue(struct irq_work *work)
+bool irq_work_needs_cpu(void)
 {
-	if (!irq_work_claim(work)) {
-		/*
-		 * Already enqueued, can't do!
-		 */
+	struct llist_head *this_list;
+
+	this_list = &__get_cpu_var(irq_work_list);
+	if (llist_empty(this_list))
 		return false;
-	}
 
-	__irq_work_queue(work);
+	/* All work should have been flushed before going offline */
+	WARN_ON_ONCE(cpu_is_offline(smp_processor_id()));
+
 	return true;
 }
-EXPORT_SYMBOL_GPL(irq_work_queue);
 
-/*
- * Run the irq_work entries on this cpu. Requires to be ran from hardirq
- * context with local IRQs disabled.
- */
-void irq_work_run(void)
+static void __irq_work_run(void)
 {
+	unsigned long flags;
 	struct irq_work *work;
 	struct llist_head *this_list;
 	struct llist_node *llnode;
 
+
+	/*
+	 * Reset the "raised" state right before we check the list because
+	 * an NMI may enqueue after we find the list empty from the runner.
+	 */
+	__this_cpu_write(irq_work_raised, 0);
+	barrier();
+
 	this_list = &__get_cpu_var(irq_work_list);
 	if (llist_empty(this_list))
 		return;
 
-	BUG_ON(!in_irq());
 	BUG_ON(!irqs_disabled());
 
 	llnode = llist_del_all(this_list);
@@ -119,16 +130,31 @@ void irq_work_run(void)
 		/*
 		 * Clear the PENDING bit, after this point the @work
 		 * can be re-used.
+		 * Make it immediately visible so that other CPUs trying
+		 * to claim that work don't rely on us to handle their data
+		 * while we are in the middle of the func.
 		 */
-		work->flags = IRQ_WORK_BUSY;
+		flags = work->flags & ~IRQ_WORK_PENDING;
+		xchg(&work->flags, flags);
+
 		work->func(work);
 		/*
 		 * Clear the BUSY bit and return to the free state if
 		 * no-one else claimed it meanwhile.
 		 */
-		(void)cmpxchg(&work->flags, IRQ_WORK_BUSY, 0);
+		(void)cmpxchg(&work->flags, flags, flags & ~IRQ_WORK_BUSY);
 	}
 }
+
+/*
+ * Run the irq_work entries on this cpu. Requires to be ran from hardirq
+ * context with local IRQs disabled.
+ */
+void irq_work_run(void)
+{
+	BUG_ON(!in_irq());
+	__irq_work_run();
+}
 EXPORT_SYMBOL_GPL(irq_work_run);
 
 /*
@@ -143,3 +169,35 @@ void irq_work_sync(struct irq_work *work)
 		cpu_relax();
 }
 EXPORT_SYMBOL_GPL(irq_work_sync);
+
+#ifdef CONFIG_HOTPLUG_CPU
+static int irq_work_cpu_notify(struct notifier_block *self,
+			       unsigned long action, void *hcpu)
+{
+	long cpu = (long)hcpu;
+
+	switch (action) {
+	case CPU_DYING:
+		/* Called from stop_machine */
+		if (WARN_ON_ONCE(cpu != smp_processor_id()))
+			break;
+		__irq_work_run();
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cpu_notify;
+
+static __init int irq_work_init_cpu_notifier(void)
+{
+	cpu_notify.notifier_call = irq_work_cpu_notify;
+	cpu_notify.priority = 0;
+	register_cpu_notifier(&cpu_notify);
+	return 0;
+}
+device_initcall(irq_work_init_cpu_notifier);
+
+#endif /* CONFIG_HOTPLUG_CPU */
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 5e4bd7864c5d..bddd3d7a74b6 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -54,6 +54,12 @@ struct resource crashk_res = {
 	.end   = 0,
 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM
 };
+struct resource crashk_low_res = {
+	.name  = "Crash kernel low",
+	.start = 0,
+	.end   = 0,
+	.flags = IORESOURCE_BUSY | IORESOURCE_MEM
+};
 
 int kexec_should_crash(struct task_struct *p)
 {
@@ -223,6 +229,8 @@ out:
 
 }
 
+static void kimage_free_page_list(struct list_head *list);
+
 static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
 				unsigned long nr_segments,
 				struct kexec_segment __user *segments)
@@ -236,8 +244,6 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
 	if (result)
 		goto out;
 
-	*rimage = image;
-
 	/*
 	 * Find a location for the control code buffer, and add it
 	 * the vector of segments so that it's pages will also be
@@ -248,22 +254,22 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
 					   get_order(KEXEC_CONTROL_PAGE_SIZE));
 	if (!image->control_code_page) {
 		printk(KERN_ERR "Could not allocate control_code_buffer\n");
-		goto out;
+		goto out_free;
 	}
 
 	image->swap_page = kimage_alloc_control_pages(image, 0);
 	if (!image->swap_page) {
 		printk(KERN_ERR "Could not allocate swap buffer\n");
-		goto out;
+		goto out_free;
 	}
 
-	result = 0;
- out:
-	if (result == 0)
-		*rimage = image;
-	else
-		kfree(image);
+	*rimage = image;
+	return 0;
 
+out_free:
+	kimage_free_page_list(&image->control_pages);
+	kfree(image);
+out:
 	return result;
 }
 
@@ -310,7 +316,7 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
 		mend = mstart + image->segment[i].memsz - 1;
 		/* Ensure we are within the crash kernel limits */
 		if ((mstart < crashk_res.start) || (mend > crashk_res.end))
-			goto out;
+			goto out_free;
 	}
 
 	/*
@@ -323,16 +329,15 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
 					   get_order(KEXEC_CONTROL_PAGE_SIZE));
 	if (!image->control_code_page) {
 		printk(KERN_ERR "Could not allocate control_code_buffer\n");
-		goto out;
+		goto out_free;
 	}
 
-	result = 0;
-out:
-	if (result == 0)
-		*rimage = image;
-	else
-		kfree(image);
+	*rimage = image;
+	return 0;
 
+out_free:
+	kfree(image);
+out:
 	return result;
 }
 
@@ -497,8 +502,6 @@ static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
 
 		if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
 			break;
-		if (hole_end > crashk_res.end)
-			break;
 		/* See if I overlap any of the segments */
 		for (i = 0; i < image->nr_segments; i++) {
 			unsigned long mstart, mend;
@@ -1369,10 +1372,11 @@ static int __init parse_crashkernel_simple(char 		*cmdline,
  * That function is the entry point for command line parsing and should be
  * called from the arch-specific code.
  */
-int __init parse_crashkernel(char 		 *cmdline,
+static int __init __parse_crashkernel(char *cmdline,
 			     unsigned long long system_ram,
 			     unsigned long long *crash_size,
-			     unsigned long long *crash_base)
+			     unsigned long long *crash_base,
+				const char *name)
 {
 	char 	*p = cmdline, *ck_cmdline = NULL;
 	char	*first_colon, *first_space;
@@ -1382,16 +1386,16 @@ int __init parse_crashkernel(char 		 *cmdline,
 	*crash_base = 0;
 
 	/* find crashkernel and use the last one if there are more */
-	p = strstr(p, "crashkernel=");
+	p = strstr(p, name);
 	while (p) {
 		ck_cmdline = p;
-		p = strstr(p+1, "crashkernel=");
+		p = strstr(p+1, name);
 	}
 
 	if (!ck_cmdline)
 		return -EINVAL;
 
-	ck_cmdline += 12; /* strlen("crashkernel=") */
+	ck_cmdline += strlen(name);
 
 	/*
 	 * if the commandline contains a ':', then that's the extended
@@ -1409,6 +1413,23 @@ int __init parse_crashkernel(char 		 *cmdline,
 	return 0;
 }
 
+int __init parse_crashkernel(char *cmdline,
+			     unsigned long long system_ram,
+			     unsigned long long *crash_size,
+			     unsigned long long *crash_base)
+{
+	return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
+					"crashkernel=");
+}
+
+int __init parse_crashkernel_low(char *cmdline,
+			     unsigned long long system_ram,
+			     unsigned long long *crash_size,
+			     unsigned long long *crash_base)
+{
+	return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
+					"crashkernel_low=");
+}
 
 static void update_vmcoreinfo_note(void)
 {
@@ -1490,6 +1511,8 @@ static int __init crash_save_vmcoreinfo_init(void)
 	VMCOREINFO_OFFSET(page, _count);
 	VMCOREINFO_OFFSET(page, mapping);
 	VMCOREINFO_OFFSET(page, lru);
+	VMCOREINFO_OFFSET(page, _mapcount);
+	VMCOREINFO_OFFSET(page, private);
 	VMCOREINFO_OFFSET(pglist_data, node_zones);
 	VMCOREINFO_OFFSET(pglist_data, nr_zones);
 #ifdef CONFIG_FLAT_NODE_MEM_MAP
@@ -1512,6 +1535,11 @@ static int __init crash_save_vmcoreinfo_init(void)
 	VMCOREINFO_NUMBER(PG_lru);
 	VMCOREINFO_NUMBER(PG_private);
 	VMCOREINFO_NUMBER(PG_swapcache);
+	VMCOREINFO_NUMBER(PG_slab);
+#ifdef CONFIG_MEMORY_FAILURE
+	VMCOREINFO_NUMBER(PG_hwpoison);
+#endif
+	VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
 
 	arch_crash_save_vmcoreinfo();
 	update_vmcoreinfo_note();
diff --git a/kernel/kfifo.c b/kernel/kfifo.c
deleted file mode 100644
index 59dcf5b81d24..000000000000
--- a/kernel/kfifo.c
+++ /dev/null
@@ -1,609 +0,0 @@
-/*
- * A generic kernel FIFO implementation
- *
- * Copyright (C) 2009/2010 Stefani Seibold <stefani@seibold.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- */
-
-#include <linux/kernel.h>
-#include <linux/export.h>
-#include <linux/slab.h>
-#include <linux/err.h>
-#include <linux/log2.h>
-#include <linux/uaccess.h>
-#include <linux/kfifo.h>
-
-/*
- * internal helper to calculate the unused elements in a fifo
- */
-static inline unsigned int kfifo_unused(struct __kfifo *fifo)
-{
-	return (fifo->mask + 1) - (fifo->in - fifo->out);
-}
-
-int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
-		size_t esize, gfp_t gfp_mask)
-{
-	/*
-	 * round down to the next power of 2, since our 'let the indices
-	 * wrap' technique works only in this case.
-	 */
-	if (!is_power_of_2(size))
-		size = rounddown_pow_of_two(size);
-
-	fifo->in = 0;
-	fifo->out = 0;
-	fifo->esize = esize;
-
-	if (size < 2) {
-		fifo->data = NULL;
-		fifo->mask = 0;
-		return -EINVAL;
-	}
-
-	fifo->data = kmalloc(size * esize, gfp_mask);
-
-	if (!fifo->data) {
-		fifo->mask = 0;
-		return -ENOMEM;
-	}
-	fifo->mask = size - 1;
-
-	return 0;
-}
-EXPORT_SYMBOL(__kfifo_alloc);
-
-void __kfifo_free(struct __kfifo *fifo)
-{
-	kfree(fifo->data);
-	fifo->in = 0;
-	fifo->out = 0;
-	fifo->esize = 0;
-	fifo->data = NULL;
-	fifo->mask = 0;
-}
-EXPORT_SYMBOL(__kfifo_free);
-
-int __kfifo_init(struct __kfifo *fifo, void *buffer,
-		unsigned int size, size_t esize)
-{
-	size /= esize;
-
-	if (!is_power_of_2(size))
-		size = rounddown_pow_of_two(size);
-
-	fifo->in = 0;
-	fifo->out = 0;
-	fifo->esize = esize;
-	fifo->data = buffer;
-
-	if (size < 2) {
-		fifo->mask = 0;
-		return -EINVAL;
-	}
-	fifo->mask = size - 1;
-
-	return 0;
-}
-EXPORT_SYMBOL(__kfifo_init);
-
-static void kfifo_copy_in(struct __kfifo *fifo, const void *src,
-		unsigned int len, unsigned int off)
-{
-	unsigned int size = fifo->mask + 1;
-	unsigned int esize = fifo->esize;
-	unsigned int l;
-
-	off &= fifo->mask;
-	if (esize != 1) {
-		off *= esize;
-		size *= esize;
-		len *= esize;
-	}
-	l = min(len, size - off);
-
-	memcpy(fifo->data + off, src, l);
-	memcpy(fifo->data, src + l, len - l);
-	/*
-	 * make sure that the data in the fifo is up to date before
-	 * incrementing the fifo->in index counter
-	 */
-	smp_wmb();
-}
-
-unsigned int __kfifo_in(struct __kfifo *fifo,
-		const void *buf, unsigned int len)
-{
-	unsigned int l;
-
-	l = kfifo_unused(fifo);
-	if (len > l)
-		len = l;
-
-	kfifo_copy_in(fifo, buf, len, fifo->in);
-	fifo->in += len;
-	return len;
-}
-EXPORT_SYMBOL(__kfifo_in);
-
-static void kfifo_copy_out(struct __kfifo *fifo, void *dst,
-		unsigned int len, unsigned int off)
-{
-	unsigned int size = fifo->mask + 1;
-	unsigned int esize = fifo->esize;
-	unsigned int l;
-
-	off &= fifo->mask;
-	if (esize != 1) {
-		off *= esize;
-		size *= esize;
-		len *= esize;
-	}
-	l = min(len, size - off);
-
-	memcpy(dst, fifo->data + off, l);
-	memcpy(dst + l, fifo->data, len - l);
-	/*
-	 * make sure that the data is copied before
-	 * incrementing the fifo->out index counter
-	 */
-	smp_wmb();
-}
-
-unsigned int __kfifo_out_peek(struct __kfifo *fifo,
-		void *buf, unsigned int len)
-{
-	unsigned int l;
-
-	l = fifo->in - fifo->out;
-	if (len > l)
-		len = l;
-
-	kfifo_copy_out(fifo, buf, len, fifo->out);
-	return len;
-}
-EXPORT_SYMBOL(__kfifo_out_peek);
-
-unsigned int __kfifo_out(struct __kfifo *fifo,
-		void *buf, unsigned int len)
-{
-	len = __kfifo_out_peek(fifo, buf, len);
-	fifo->out += len;
-	return len;
-}
-EXPORT_SYMBOL(__kfifo_out);
-
-static unsigned long kfifo_copy_from_user(struct __kfifo *fifo,
-	const void __user *from, unsigned int len, unsigned int off,
-	unsigned int *copied)
-{
-	unsigned int size = fifo->mask + 1;
-	unsigned int esize = fifo->esize;
-	unsigned int l;
-	unsigned long ret;
-
-	off &= fifo->mask;
-	if (esize != 1) {
-		off *= esize;
-		size *= esize;
-		len *= esize;
-	}
-	l = min(len, size - off);
-
-	ret = copy_from_user(fifo->data + off, from, l);
-	if (unlikely(ret))
-		ret = DIV_ROUND_UP(ret + len - l, esize);
-	else {
-		ret = copy_from_user(fifo->data, from + l, len - l);
-		if (unlikely(ret))
-			ret = DIV_ROUND_UP(ret, esize);
-	}
-	/*
-	 * make sure that the data in the fifo is up to date before
-	 * incrementing the fifo->in index counter
-	 */
-	smp_wmb();
-	*copied = len - ret;
-	/* return the number of elements which are not copied */
-	return ret;
-}
-
-int __kfifo_from_user(struct __kfifo *fifo, const void __user *from,
-		unsigned long len, unsigned int *copied)
-{
-	unsigned int l;
-	unsigned long ret;
-	unsigned int esize = fifo->esize;
-	int err;
-
-	if (esize != 1)
-		len /= esize;
-
-	l = kfifo_unused(fifo);
-	if (len > l)
-		len = l;
-
-	ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied);
-	if (unlikely(ret)) {
-		len -= ret;
-		err = -EFAULT;
-	} else
-		err = 0;
-	fifo->in += len;
-	return err;
-}
-EXPORT_SYMBOL(__kfifo_from_user);
-
-static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to,
-		unsigned int len, unsigned int off, unsigned int *copied)
-{
-	unsigned int l;
-	unsigned long ret;
-	unsigned int size = fifo->mask + 1;
-	unsigned int esize = fifo->esize;
-
-	off &= fifo->mask;
-	if (esize != 1) {
-		off *= esize;
-		size *= esize;
-		len *= esize;
-	}
-	l = min(len, size - off);
-
-	ret = copy_to_user(to, fifo->data + off, l);
-	if (unlikely(ret))
-		ret = DIV_ROUND_UP(ret + len - l, esize);
-	else {
-		ret = copy_to_user(to + l, fifo->data, len - l);
-		if (unlikely(ret))
-			ret = DIV_ROUND_UP(ret, esize);
-	}
-	/*
-	 * make sure that the data is copied before
-	 * incrementing the fifo->out index counter
-	 */
-	smp_wmb();
-	*copied = len - ret;
-	/* return the number of elements which are not copied */
-	return ret;
-}
-
-int __kfifo_to_user(struct __kfifo *fifo, void __user *to,
-		unsigned long len, unsigned int *copied)
-{
-	unsigned int l;
-	unsigned long ret;
-	unsigned int esize = fifo->esize;
-	int err;
-
-	if (esize != 1)
-		len /= esize;
-
-	l = fifo->in - fifo->out;
-	if (len > l)
-		len = l;
-	ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied);
-	if (unlikely(ret)) {
-		len -= ret;
-		err = -EFAULT;
-	} else
-		err = 0;
-	fifo->out += len;
-	return err;
-}
-EXPORT_SYMBOL(__kfifo_to_user);
-
-static int setup_sgl_buf(struct scatterlist *sgl, void *buf,
-		int nents, unsigned int len)
-{
-	int n;
-	unsigned int l;
-	unsigned int off;
-	struct page *page;
-
-	if (!nents)
-		return 0;
-
-	if (!len)
-		return 0;
-
-	n = 0;
-	page = virt_to_page(buf);
-	off = offset_in_page(buf);
-	l = 0;
-
-	while (len >= l + PAGE_SIZE - off) {
-		struct page *npage;
-
-		l += PAGE_SIZE;
-		buf += PAGE_SIZE;
-		npage = virt_to_page(buf);
-		if (page_to_phys(page) != page_to_phys(npage) - l) {
-			sg_set_page(sgl, page, l - off, off);
-			sgl = sg_next(sgl);
-			if (++n == nents || sgl == NULL)
-				return n;
-			page = npage;
-			len -= l - off;
-			l = off = 0;
-		}
-	}
-	sg_set_page(sgl, page, len, off);
-	return n + 1;
-}
-
-static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,
-		int nents, unsigned int len, unsigned int off)
-{
-	unsigned int size = fifo->mask + 1;
-	unsigned int esize = fifo->esize;
-	unsigned int l;
-	unsigned int n;
-
-	off &= fifo->mask;
-	if (esize != 1) {
-		off *= esize;
-		size *= esize;
-		len *= esize;
-	}
-	l = min(len, size - off);
-
-	n = setup_sgl_buf(sgl, fifo->data + off, nents, l);
-	n += setup_sgl_buf(sgl + n, fifo->data, nents - n, len - l);
-
-	return n;
-}
-
-unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
-		struct scatterlist *sgl, int nents, unsigned int len)
-{
-	unsigned int l;
-
-	l = kfifo_unused(fifo);
-	if (len > l)
-		len = l;
-
-	return setup_sgl(fifo, sgl, nents, len, fifo->in);
-}
-EXPORT_SYMBOL(__kfifo_dma_in_prepare);
-
-unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
-		struct scatterlist *sgl, int nents, unsigned int len)
-{
-	unsigned int l;
-
-	l = fifo->in - fifo->out;
-	if (len > l)
-		len = l;
-
-	return setup_sgl(fifo, sgl, nents, len, fifo->out);
-}
-EXPORT_SYMBOL(__kfifo_dma_out_prepare);
-
-unsigned int __kfifo_max_r(unsigned int len, size_t recsize)
-{
-	unsigned int max = (1 << (recsize << 3)) - 1;
-
-	if (len > max)
-		return max;
-	return len;
-}
-EXPORT_SYMBOL(__kfifo_max_r);
-
-#define	__KFIFO_PEEK(data, out, mask) \
-	((data)[(out) & (mask)])
-/*
- * __kfifo_peek_n internal helper function for determinate the length of
- * the next record in the fifo
- */
-static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize)
-{
-	unsigned int l;
-	unsigned int mask = fifo->mask;
-	unsigned char *data = fifo->data;
-
-	l = __KFIFO_PEEK(data, fifo->out, mask);
-
-	if (--recsize)
-		l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8;
-
-	return l;
-}
-
-#define	__KFIFO_POKE(data, in, mask, val) \
-	( \
-	(data)[(in) & (mask)] = (unsigned char)(val) \
-	)
-
-/*
- * __kfifo_poke_n internal helper function for storeing the length of
- * the record into the fifo
- */
-static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize)
-{
-	unsigned int mask = fifo->mask;
-	unsigned char *data = fifo->data;
-
-	__KFIFO_POKE(data, fifo->in, mask, n);
-
-	if (recsize > 1)
-		__KFIFO_POKE(data, fifo->in + 1, mask, n >> 8);
-}
-
-unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize)
-{
-	return __kfifo_peek_n(fifo, recsize);
-}
-EXPORT_SYMBOL(__kfifo_len_r);
-
-unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf,
-		unsigned int len, size_t recsize)
-{
-	if (len + recsize > kfifo_unused(fifo))
-		return 0;
-
-	__kfifo_poke_n(fifo, len, recsize);
-
-	kfifo_copy_in(fifo, buf, len, fifo->in + recsize);
-	fifo->in += len + recsize;
-	return len;
-}
-EXPORT_SYMBOL(__kfifo_in_r);
-
-static unsigned int kfifo_out_copy_r(struct __kfifo *fifo,
-	void *buf, unsigned int len, size_t recsize, unsigned int *n)
-{
-	*n = __kfifo_peek_n(fifo, recsize);
-
-	if (len > *n)
-		len = *n;
-
-	kfifo_copy_out(fifo, buf, len, fifo->out + recsize);
-	return len;
-}
-
-unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf,
-		unsigned int len, size_t recsize)
-{
-	unsigned int n;
-
-	if (fifo->in == fifo->out)
-		return 0;
-
-	return kfifo_out_copy_r(fifo, buf, len, recsize, &n);
-}
-EXPORT_SYMBOL(__kfifo_out_peek_r);
-
-unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,
-		unsigned int len, size_t recsize)
-{
-	unsigned int n;
-
-	if (fifo->in == fifo->out)
-		return 0;
-
-	len = kfifo_out_copy_r(fifo, buf, len, recsize, &n);
-	fifo->out += n + recsize;
-	return len;
-}
-EXPORT_SYMBOL(__kfifo_out_r);
-
-void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize)
-{
-	unsigned int n;
-
-	n = __kfifo_peek_n(fifo, recsize);
-	fifo->out += n + recsize;
-}
-EXPORT_SYMBOL(__kfifo_skip_r);
-
-int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,
-	unsigned long len, unsigned int *copied, size_t recsize)
-{
-	unsigned long ret;
-
-	len = __kfifo_max_r(len, recsize);
-
-	if (len + recsize > kfifo_unused(fifo)) {
-		*copied = 0;
-		return 0;
-	}
-
-	__kfifo_poke_n(fifo, len, recsize);
-
-	ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied);
-	if (unlikely(ret)) {
-		*copied = 0;
-		return -EFAULT;
-	}
-	fifo->in += len + recsize;
-	return 0;
-}
-EXPORT_SYMBOL(__kfifo_from_user_r);
-
-int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
-	unsigned long len, unsigned int *copied, size_t recsize)
-{
-	unsigned long ret;
-	unsigned int n;
-
-	if (fifo->in == fifo->out) {
-		*copied = 0;
-		return 0;
-	}
-
-	n = __kfifo_peek_n(fifo, recsize);
-	if (len > n)
-		len = n;
-
-	ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied);
-	if (unlikely(ret)) {
-		*copied = 0;
-		return -EFAULT;
-	}
-	fifo->out += n + recsize;
-	return 0;
-}
-EXPORT_SYMBOL(__kfifo_to_user_r);
-
-unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
-	struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
-{
-	if (!nents)
-		BUG();
-
-	len = __kfifo_max_r(len, recsize);
-
-	if (len + recsize > kfifo_unused(fifo))
-		return 0;
-
-	return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize);
-}
-EXPORT_SYMBOL(__kfifo_dma_in_prepare_r);
-
-void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
-	unsigned int len, size_t recsize)
-{
-	len = __kfifo_max_r(len, recsize);
-	__kfifo_poke_n(fifo, len, recsize);
-	fifo->in += len + recsize;
-}
-EXPORT_SYMBOL(__kfifo_dma_in_finish_r);
-
-unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
-	struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
-{
-	if (!nents)
-		BUG();
-
-	len = __kfifo_max_r(len, recsize);
-
-	if (len + recsize > fifo->in - fifo->out)
-		return 0;
-
-	return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize);
-}
-EXPORT_SYMBOL(__kfifo_dma_out_prepare_r);
-
-void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize)
-{
-	unsigned int len;
-
-	len = __kfifo_peek_n(fifo, recsize);
-	fifo->out += len + recsize;
-}
-EXPORT_SYMBOL(__kfifo_dma_out_finish_r);
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 0023a87e8de6..56dd34976d7b 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -38,6 +38,7 @@
 #include <linux/suspend.h>
 #include <linux/rwsem.h>
 #include <linux/ptrace.h>
+#include <linux/async.h>
 #include <asm/uaccess.h>
 
 #include <trace/events/module.h>
@@ -130,6 +131,14 @@ int __request_module(bool wait, const char *fmt, ...)
 #define MAX_KMOD_CONCURRENT 50	/* Completely arbitrary value - KAO */
 	static int kmod_loop_msg;
 
+	/*
+	 * We don't allow synchronous module loading from async.  Module
+	 * init may invoke async_synchronize_full() which will end up
+	 * waiting for this task which already is waiting for the module
+	 * loading to complete, leading to a deadlock.
+	 */
+	WARN_ON_ONCE(wait && current_is_async());
+
 	va_start(args, fmt);
 	ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args);
 	va_end(args);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 098f396aa409..e35be53f6613 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -334,11 +334,10 @@ static inline void reset_kprobe_instance(void)
 struct kprobe __kprobes *get_kprobe(void *addr)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 
 	head = &kprobe_table[hash_ptr(addr, KPROBE_HASH_BITS)];
-	hlist_for_each_entry_rcu(p, node, head, hlist) {
+	hlist_for_each_entry_rcu(p, head, hlist) {
 		if (p->addr == addr)
 			return p;
 	}
@@ -471,7 +470,6 @@ static LIST_HEAD(unoptimizing_list);
 
 static void kprobe_optimizer(struct work_struct *work);
 static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
-static DECLARE_COMPLETION(optimizer_comp);
 #define OPTIMIZE_DELAY 5
 
 /*
@@ -552,8 +550,7 @@ static __kprobes void do_free_cleaned_kprobes(struct list_head *free_list)
 /* Start optimizer after OPTIMIZE_DELAY passed */
 static __kprobes void kick_kprobe_optimizer(void)
 {
-	if (!delayed_work_pending(&optimizing_work))
-		schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY);
+	schedule_delayed_work(&optimizing_work, OPTIMIZE_DELAY);
 }
 
 /* Kprobe jump optimizer */
@@ -592,16 +589,25 @@ static __kprobes void kprobe_optimizer(struct work_struct *work)
 	/* Step 5: Kick optimizer again if needed */
 	if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list))
 		kick_kprobe_optimizer();
-	else
-		/* Wake up all waiters */
-		complete_all(&optimizer_comp);
 }
 
 /* Wait for completing optimization and unoptimization */
 static __kprobes void wait_for_kprobe_optimizer(void)
 {
-	if (delayed_work_pending(&optimizing_work))
-		wait_for_completion(&optimizer_comp);
+	mutex_lock(&kprobe_mutex);
+
+	while (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list)) {
+		mutex_unlock(&kprobe_mutex);
+
+		/* this will also make optimizing_work execute immmediately */
+		flush_delayed_work(&optimizing_work);
+		/* @optimizing_work might not have been queued yet, relax */
+		cpu_relax();
+
+		mutex_lock(&kprobe_mutex);
+	}
+
+	mutex_unlock(&kprobe_mutex);
 }
 
 /* Optimize kprobe if p is ready to be optimized */
@@ -792,7 +798,6 @@ out:
 static void __kprobes optimize_all_kprobes(void)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 	unsigned int i;
 
@@ -803,7 +808,7 @@ static void __kprobes optimize_all_kprobes(void)
 	kprobes_allow_optimization = true;
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, node, head, hlist)
+		hlist_for_each_entry_rcu(p, head, hlist)
 			if (!kprobe_disabled(p))
 				optimize_kprobe(p);
 	}
@@ -814,7 +819,6 @@ static void __kprobes optimize_all_kprobes(void)
 static void __kprobes unoptimize_all_kprobes(void)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 	unsigned int i;
 
@@ -825,7 +829,7 @@ static void __kprobes unoptimize_all_kprobes(void)
 	kprobes_allow_optimization = false;
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, node, head, hlist) {
+		hlist_for_each_entry_rcu(p, head, hlist) {
 			if (!kprobe_disabled(p))
 				unoptimize_kprobe(p, false);
 		}
@@ -919,7 +923,7 @@ static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p)
 }
 #endif /* CONFIG_OPTPROBES */
 
-#ifdef KPROBES_CAN_USE_FTRACE
+#ifdef CONFIG_KPROBES_ON_FTRACE
 static struct ftrace_ops kprobe_ftrace_ops __read_mostly = {
 	.func = kprobe_ftrace_handler,
 	.flags = FTRACE_OPS_FL_SAVE_REGS,
@@ -964,7 +968,7 @@ static void __kprobes disarm_kprobe_ftrace(struct kprobe *p)
 			   (unsigned long)p->addr, 1, 0);
 	WARN(ret < 0, "Failed to disarm kprobe-ftrace at %p (%d)\n", p->addr, ret);
 }
-#else	/* !KPROBES_CAN_USE_FTRACE */
+#else	/* !CONFIG_KPROBES_ON_FTRACE */
 #define prepare_kprobe(p)	arch_prepare_kprobe(p)
 #define arm_kprobe_ftrace(p)	do {} while (0)
 #define disarm_kprobe_ftrace(p)	do {} while (0)
@@ -1141,7 +1145,7 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
 {
 	struct kretprobe_instance *ri;
 	struct hlist_head *head, empty_rp;
-	struct hlist_node *node, *tmp;
+	struct hlist_node *tmp;
 	unsigned long hash, flags = 0;
 
 	if (unlikely(!kprobes_initialized))
@@ -1152,12 +1156,12 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
 	hash = hash_ptr(tk, KPROBE_HASH_BITS);
 	head = &kretprobe_inst_table[hash];
 	kretprobe_table_lock(hash, &flags);
-	hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
+	hlist_for_each_entry_safe(ri, tmp, head, hlist) {
 		if (ri->task == tk)
 			recycle_rp_inst(ri, &empty_rp);
 	}
 	kretprobe_table_unlock(hash, &flags);
-	hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
+	hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
 		hlist_del(&ri->hlist);
 		kfree(ri);
 	}
@@ -1166,9 +1170,9 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
 static inline void free_rp_inst(struct kretprobe *rp)
 {
 	struct kretprobe_instance *ri;
-	struct hlist_node *pos, *next;
+	struct hlist_node *next;
 
-	hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) {
+	hlist_for_each_entry_safe(ri, next, &rp->free_instances, hlist) {
 		hlist_del(&ri->hlist);
 		kfree(ri);
 	}
@@ -1178,14 +1182,14 @@ static void __kprobes cleanup_rp_inst(struct kretprobe *rp)
 {
 	unsigned long flags, hash;
 	struct kretprobe_instance *ri;
-	struct hlist_node *pos, *next;
+	struct hlist_node *next;
 	struct hlist_head *head;
 
 	/* No race here */
 	for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) {
 		kretprobe_table_lock(hash, &flags);
 		head = &kretprobe_inst_table[hash];
-		hlist_for_each_entry_safe(ri, pos, next, head, hlist) {
+		hlist_for_each_entry_safe(ri, next, head, hlist) {
 			if (ri->rp == rp)
 				ri->rp = NULL;
 		}
@@ -1414,12 +1418,12 @@ static __kprobes int check_kprobe_address_safe(struct kprobe *p,
 	 */
 	ftrace_addr = ftrace_location((unsigned long)p->addr);
 	if (ftrace_addr) {
-#ifdef KPROBES_CAN_USE_FTRACE
+#ifdef CONFIG_KPROBES_ON_FTRACE
 		/* Given address is not on the instruction boundary */
 		if ((unsigned long)p->addr != ftrace_addr)
 			return -EILSEQ;
 		p->flags |= KPROBE_FLAG_FTRACE;
-#else	/* !KPROBES_CAN_USE_FTRACE */
+#else	/* !CONFIG_KPROBES_ON_FTRACE */
 		return -EINVAL;
 #endif
 	}
@@ -2021,7 +2025,6 @@ static int __kprobes kprobes_module_callback(struct notifier_block *nb,
 {
 	struct module *mod = data;
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 	unsigned int i;
 	int checkcore = (val == MODULE_STATE_GOING);
@@ -2038,7 +2041,7 @@ static int __kprobes kprobes_module_callback(struct notifier_block *nb,
 	mutex_lock(&kprobe_mutex);
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, node, head, hlist)
+		hlist_for_each_entry_rcu(p, head, hlist)
 			if (within_module_init((unsigned long)p->addr, mod) ||
 			    (checkcore &&
 			     within_module_core((unsigned long)p->addr, mod))) {
@@ -2185,7 +2188,6 @@ static void __kprobes kprobe_seq_stop(struct seq_file *f, void *v)
 static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p, *kp;
 	const char *sym = NULL;
 	unsigned int i = *(loff_t *) v;
@@ -2194,7 +2196,7 @@ static int __kprobes show_kprobe_addr(struct seq_file *pi, void *v)
 
 	head = &kprobe_table[i];
 	preempt_disable();
-	hlist_for_each_entry_rcu(p, node, head, hlist) {
+	hlist_for_each_entry_rcu(p, head, hlist) {
 		sym = kallsyms_lookup((unsigned long)p->addr, NULL,
 					&offset, &modname, namebuf);
 		if (kprobe_aggrprobe(p)) {
@@ -2229,7 +2231,6 @@ static const struct file_operations debugfs_kprobes_operations = {
 static void __kprobes arm_all_kprobes(void)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 	unsigned int i;
 
@@ -2242,7 +2243,7 @@ static void __kprobes arm_all_kprobes(void)
 	/* Arming kprobes doesn't optimize kprobe itself */
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, node, head, hlist)
+		hlist_for_each_entry_rcu(p, head, hlist)
 			if (!kprobe_disabled(p))
 				arm_kprobe(p);
 	}
@@ -2258,7 +2259,6 @@ already_enabled:
 static void __kprobes disarm_all_kprobes(void)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct kprobe *p;
 	unsigned int i;
 
@@ -2275,7 +2275,7 @@ static void __kprobes disarm_all_kprobes(void)
 
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
-		hlist_for_each_entry_rcu(p, node, head, hlist) {
+		hlist_for_each_entry_rcu(p, head, hlist) {
 			if (!arch_trampoline_kprobe(p) && !kprobe_disabled(p))
 				disarm_kprobe(p, false);
 		}
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 7981e5b2350d..259db207b5d9 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3190,9 +3190,14 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 #endif
 	if (unlikely(curr->lockdep_depth >= MAX_LOCK_DEPTH)) {
 		debug_locks_off();
-		printk("BUG: MAX_LOCK_DEPTH too low!\n");
+		printk("BUG: MAX_LOCK_DEPTH too low, depth: %i  max: %lu!\n",
+		       curr->lockdep_depth, MAX_LOCK_DEPTH);
 		printk("turning off the locking correctness validator.\n");
+
+		lockdep_print_held_locks(current);
+		debug_show_all_locks();
 		dump_stack();
+
 		return 0;
 	}
 
@@ -3203,7 +3208,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
 }
 
 static int
-print_unlock_inbalance_bug(struct task_struct *curr, struct lockdep_map *lock,
+print_unlock_imbalance_bug(struct task_struct *curr, struct lockdep_map *lock,
 			   unsigned long ip)
 {
 	if (!debug_locks_off())
@@ -3246,7 +3251,7 @@ static int check_unlock(struct task_struct *curr, struct lockdep_map *lock,
 		return 0;
 
 	if (curr->lockdep_depth <= 0)
-		return print_unlock_inbalance_bug(curr, lock, ip);
+		return print_unlock_imbalance_bug(curr, lock, ip);
 
 	return 1;
 }
@@ -3317,7 +3322,7 @@ __lock_set_class(struct lockdep_map *lock, const char *name,
 			goto found_it;
 		prev_hlock = hlock;
 	}
-	return print_unlock_inbalance_bug(curr, lock, ip);
+	return print_unlock_imbalance_bug(curr, lock, ip);
 
 found_it:
 	lockdep_init_map(lock, name, key, 0);
@@ -3384,7 +3389,7 @@ lock_release_non_nested(struct task_struct *curr,
 			goto found_it;
 		prev_hlock = hlock;
 	}
-	return print_unlock_inbalance_bug(curr, lock, ip);
+	return print_unlock_imbalance_bug(curr, lock, ip);
 
 found_it:
 	if (hlock->instance == lock)
@@ -4083,7 +4088,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
 }
 EXPORT_SYMBOL_GPL(debug_check_no_locks_freed);
 
-static void print_held_locks_bug(struct task_struct *curr)
+static void print_held_locks_bug(void)
 {
 	if (!debug_locks_off())
 		return;
@@ -4092,22 +4097,21 @@ static void print_held_locks_bug(struct task_struct *curr)
 
 	printk("\n");
 	printk("=====================================\n");
-	printk("[ BUG: lock held at task exit time! ]\n");
+	printk("[ BUG: %s/%d still has locks held! ]\n",
+	       current->comm, task_pid_nr(current));
 	print_kernel_ident();
 	printk("-------------------------------------\n");
-	printk("%s/%d is exiting with locks still held!\n",
-		curr->comm, task_pid_nr(curr));
-	lockdep_print_held_locks(curr);
-
+	lockdep_print_held_locks(current);
 	printk("\nstack backtrace:\n");
 	dump_stack();
 }
 
-void debug_check_no_locks_held(struct task_struct *task)
+void debug_check_no_locks_held(void)
 {
-	if (unlikely(task->lockdep_depth > 0))
-		print_held_locks_bug(task);
+	if (unlikely(current->lockdep_depth > 0))
+		print_held_locks_bug();
 }
+EXPORT_SYMBOL_GPL(debug_check_no_locks_held);
 
 void debug_show_all_locks(void)
 {
diff --git a/kernel/module.c b/kernel/module.c
index eab08274ec9b..0925c9a71975 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -197,9 +197,10 @@ static inline int strong_try_module_get(struct module *mod)
 		return -ENOENT;
 }
 
-static inline void add_taint_module(struct module *mod, unsigned flag)
+static inline void add_taint_module(struct module *mod, unsigned flag,
+				    enum lockdep_ok lockdep_ok)
 {
-	add_taint(flag);
+	add_taint(flag, lockdep_ok);
 	mod->taints |= (1U << flag);
 }
 
@@ -727,7 +728,7 @@ static inline int try_force_unload(unsigned int flags)
 {
 	int ret = (flags & O_TRUNC);
 	if (ret)
-		add_taint(TAINT_FORCED_RMMOD);
+		add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
 	return ret;
 }
 #else
@@ -1138,7 +1139,7 @@ static int try_to_force_load(struct module *mod, const char *reason)
 	if (!test_taint(TAINT_FORCED_MODULE))
 		printk(KERN_WARNING "%s: %s: kernel tainted.\n",
 		       mod->name, reason);
-	add_taint_module(mod, TAINT_FORCED_MODULE);
+	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
 	return 0;
 #else
 	return -ENOEXEC;
@@ -2147,7 +2148,8 @@ static void set_license(struct module *mod, const char *license)
 		if (!test_taint(TAINT_PROPRIETARY_MODULE))
 			printk(KERN_WARNING "%s: module license '%s' taints "
 				"kernel.\n", mod->name, license);
-		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+				 LOCKDEP_NOW_UNRELIABLE);
 	}
 }
 
@@ -2539,7 +2541,7 @@ static int copy_module_from_fd(int fd, struct load_info *info)
 	if (err)
 		goto out;
 
-	err = vfs_getattr(file->f_vfsmnt, file->f_dentry, &stat);
+	err = vfs_getattr(&file->f_path, &stat);
 	if (err)
 		goto out;
 
@@ -2700,10 +2702,10 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
 	}
 
 	if (!get_modinfo(info, "intree"))
-		add_taint_module(mod, TAINT_OOT_MODULE);
+		add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
 
 	if (get_modinfo(info, "staging")) {
-		add_taint_module(mod, TAINT_CRAP);
+		add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
 		printk(KERN_WARNING "%s: module is from the staging directory,"
 		       " the quality is unknown, you have been warned.\n",
 		       mod->name);
@@ -2869,15 +2871,17 @@ static int check_module_license_and_versions(struct module *mod)
 	 * using GPL-only symbols it needs.
 	 */
 	if (strcmp(mod->name, "ndiswrapper") == 0)
-		add_taint(TAINT_PROPRIETARY_MODULE);
+		add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
 
 	/* driverloader was caught wrongly pretending to be under GPL */
 	if (strcmp(mod->name, "driverloader") == 0)
-		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+				 LOCKDEP_NOW_UNRELIABLE);
 
 	/* lve claims to be GPL but upstream won't provide source */
 	if (strcmp(mod->name, "lve") == 0)
-		add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+		add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
+				 LOCKDEP_NOW_UNRELIABLE);
 
 #ifdef CONFIG_MODVERSIONS
 	if ((mod->num_syms && !mod->crcs)
@@ -3141,12 +3145,72 @@ static int may_init_module(void)
 	return 0;
 }
 
+/*
+ * We try to place it in the list now to make sure it's unique before
+ * we dedicate too many resources.  In particular, temporary percpu
+ * memory exhaustion.
+ */
+static int add_unformed_module(struct module *mod)
+{
+	int err;
+	struct module *old;
+
+	mod->state = MODULE_STATE_UNFORMED;
+
+again:
+	mutex_lock(&module_mutex);
+	if ((old = find_module_all(mod->name, true)) != NULL) {
+		if (old->state == MODULE_STATE_COMING
+		    || old->state == MODULE_STATE_UNFORMED) {
+			/* Wait in case it fails to load. */
+			mutex_unlock(&module_mutex);
+			err = wait_event_interruptible(module_wq,
+					       finished_loading(mod->name));
+			if (err)
+				goto out_unlocked;
+			goto again;
+		}
+		err = -EEXIST;
+		goto out;
+	}
+	list_add_rcu(&mod->list, &modules);
+	err = 0;
+
+out:
+	mutex_unlock(&module_mutex);
+out_unlocked:
+	return err;
+}
+
+static int complete_formation(struct module *mod, struct load_info *info)
+{
+	int err;
+
+	mutex_lock(&module_mutex);
+
+	/* Find duplicate symbols (must be called under lock). */
+	err = verify_export_symbols(mod);
+	if (err < 0)
+		goto out;
+
+	/* This relies on module_mutex for list integrity. */
+	module_bug_finalize(info->hdr, info->sechdrs, mod);
+
+	/* Mark state as coming so strong_try_module_get() ignores us,
+	 * but kallsyms etc. can see us. */
+	mod->state = MODULE_STATE_COMING;
+
+out:
+	mutex_unlock(&module_mutex);
+	return err;
+}
+
 /* Allocate and load the module: note that size of section 0 is always
    zero, and we rely on this for optional sections. */
 static int load_module(struct load_info *info, const char __user *uargs,
 		       int flags)
 {
-	struct module *mod, *old;
+	struct module *mod;
 	long err;
 
 	err = module_sig_check(info);
@@ -3164,36 +3228,20 @@ static int load_module(struct load_info *info, const char __user *uargs,
 		goto free_copy;
 	}
 
-	/*
-	 * We try to place it in the list now to make sure it's unique
-	 * before we dedicate too many resources.  In particular,
-	 * temporary percpu memory exhaustion.
-	 */
-	mod->state = MODULE_STATE_UNFORMED;
-again:
-	mutex_lock(&module_mutex);
-	if ((old = find_module_all(mod->name, true)) != NULL) {
-		if (old->state == MODULE_STATE_COMING
-		    || old->state == MODULE_STATE_UNFORMED) {
-			/* Wait in case it fails to load. */
-			mutex_unlock(&module_mutex);
-			err = wait_event_interruptible(module_wq,
-					       finished_loading(mod->name));
-			if (err)
-				goto free_module;
-			goto again;
-		}
-		err = -EEXIST;
-		mutex_unlock(&module_mutex);
+	/* Reserve our place in the list. */
+	err = add_unformed_module(mod);
+	if (err)
 		goto free_module;
-	}
-	list_add_rcu(&mod->list, &modules);
-	mutex_unlock(&module_mutex);
 
 #ifdef CONFIG_MODULE_SIG
 	mod->sig_ok = info->sig_ok;
-	if (!mod->sig_ok)
-		add_taint_module(mod, TAINT_FORCED_MODULE);
+	if (!mod->sig_ok) {
+		printk_once(KERN_NOTICE
+			    "%s: module verification failed: signature and/or"
+			    " required key missing - tainting kernel\n",
+			    mod->name);
+		add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_STILL_OK);
+	}
 #endif
 
 	/* Now module is in final location, initialize linked lists, etc. */
@@ -3236,21 +3284,11 @@ again:
 
 	dynamic_debug_setup(info->debug, info->num_debug);
 
-	mutex_lock(&module_mutex);
-	/* Find duplicate symbols (must be called under lock). */
-	err = verify_export_symbols(mod);
-	if (err < 0)
+	/* Finally it's fully formed, ready to start executing. */
+	err = complete_formation(mod, info);
+	if (err)
 		goto ddebug_cleanup;
 
-	/* This relies on module_mutex for list integrity. */
-	module_bug_finalize(info->hdr, info->sechdrs, mod);
-
-	/* Mark state as coming so strong_try_module_get() ignores us,
-	 * but kallsyms etc. can see us. */
-	mod->state = MODULE_STATE_COMING;
-
-	mutex_unlock(&module_mutex);
-
 	/* Module is ready to execute: parsing args may do that. */
 	err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
 			 -32768, 32767, &ddebug_dyndbg_module_param_cb);
@@ -3274,8 +3312,8 @@ again:
 	/* module_bug_cleanup needs module_mutex protection */
 	mutex_lock(&module_mutex);
 	module_bug_cleanup(mod);
- ddebug_cleanup:
 	mutex_unlock(&module_mutex);
+ ddebug_cleanup:
 	dynamic_debug_remove(info->debug);
 	synchronize_sched();
 	kfree(mod->args);
diff --git a/kernel/mutex.c b/kernel/mutex.c
index a307cc9c9526..52f23011b6e0 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -19,6 +19,7 @@
  */
 #include <linux/mutex.h>
 #include <linux/sched.h>
+#include <linux/sched/rt.h>
 #include <linux/export.h>
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 78e2ecb20165..afc0456f227a 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -153,8 +153,7 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
 		goto out;
 	}
 
-	new_ns = create_new_namespaces(flags, tsk,
-				       task_cred_xxx(tsk, user_ns), tsk->fs);
+	new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs);
 	if (IS_ERR(new_ns)) {
 		err = PTR_ERR(new_ns);
 		goto out;
@@ -251,7 +250,7 @@ SYSCALL_DEFINE2(setns, int, fd, int, nstype)
 		return PTR_ERR(file);
 
 	err = -EINVAL;
-	ei = PROC_I(file->f_dentry->d_inode);
+	ei = PROC_I(file_inode(file));
 	ops = ei->ns_ops;
 	if (nstype && (ops->type != nstype))
 		goto out;
diff --git a/kernel/panic.c b/kernel/panic.c
index e1b2822fff97..7c57cc9eee2c 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -259,26 +259,19 @@ unsigned long get_taint(void)
 	return tainted_mask;
 }
 
-void add_taint(unsigned flag)
+/**
+ * add_taint: add a taint flag if not already set.
+ * @flag: one of the TAINT_* constants.
+ * @lockdep_ok: whether lock debugging is still OK.
+ *
+ * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
+ * some notewortht-but-not-corrupting cases, it can be set to true.
+ */
+void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
 {
-	/*
-	 * Can't trust the integrity of the kernel anymore.
-	 * We don't call directly debug_locks_off() because the issue
-	 * is not necessarily serious enough to set oops_in_progress to 1
-	 * Also we want to keep up lockdep for staging/out-of-tree
-	 * development and post-warning case.
-	 */
-	switch (flag) {
-	case TAINT_CRAP:
-	case TAINT_OOT_MODULE:
-	case TAINT_WARN:
-	case TAINT_FIRMWARE_WORKAROUND:
-		break;
-
-	default:
-		if (__debug_locks_off())
-			printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n");
-	}
+	if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
+		printk(KERN_WARNING
+		       "Disabling lock debugging due to kernel taint\n");
 
 	set_bit(flag, &tainted_mask);
 }
@@ -421,7 +414,8 @@ static void warn_slowpath_common(const char *file, int line, void *caller,
 	print_modules();
 	dump_stack();
 	print_oops_end_marker();
-	add_taint(taint);
+	/* Just a warning, don't kill lockdep. */
+	add_taint(taint, LOCKDEP_STILL_OK);
 }
 
 void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
diff --git a/kernel/pid.c b/kernel/pid.c
index de9af600006f..047dc6264638 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -331,7 +331,7 @@ out:
 	return pid;
 
 out_unlock:
-	spin_unlock(&pidmap_lock);
+	spin_unlock_irq(&pidmap_lock);
 out_free:
 	while (++i <= ns->level)
 		free_pidmap(pid->numbers + i);
@@ -350,10 +350,9 @@ void disable_pid_allocation(struct pid_namespace *ns)
 
 struct pid *find_pid_ns(int nr, struct pid_namespace *ns)
 {
-	struct hlist_node *elem;
 	struct upid *pnr;
 
-	hlist_for_each_entry_rcu(pnr, elem,
+	hlist_for_each_entry_rcu(pnr,
 			&pid_hash[pid_hashfn(nr, ns)], pid_chain)
 		if (pnr->nr == nr && pnr->ns == ns)
 			return container_of(pnr, struct pid,
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index a278cad1d5d6..8fd709c9bb58 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -155,11 +155,19 @@ static void bump_cpu_timer(struct k_itimer *timer,
 
 static inline cputime_t prof_ticks(struct task_struct *p)
 {
-	return p->utime + p->stime;
+	cputime_t utime, stime;
+
+	task_cputime(p, &utime, &stime);
+
+	return utime + stime;
 }
 static inline cputime_t virt_ticks(struct task_struct *p)
 {
-	return p->utime;
+	cputime_t utime;
+
+	task_cputime(p, &utime, NULL);
+
+	return utime;
 }
 
 static int
@@ -471,18 +479,23 @@ static void cleanup_timers(struct list_head *head,
  */
 void posix_cpu_timers_exit(struct task_struct *tsk)
 {
+	cputime_t utime, stime;
+
 	add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
 						sizeof(unsigned long long));
+	task_cputime(tsk, &utime, &stime);
 	cleanup_timers(tsk->cpu_timers,
-		       tsk->utime, tsk->stime, tsk->se.sum_exec_runtime);
+		       utime, stime, tsk->se.sum_exec_runtime);
 
 }
 void posix_cpu_timers_exit_group(struct task_struct *tsk)
 {
 	struct signal_struct *const sig = tsk->signal;
+	cputime_t utime, stime;
 
+	task_cputime(tsk, &utime, &stime);
 	cleanup_timers(tsk->signal->cpu_timers,
-		       tsk->utime + sig->utime, tsk->stime + sig->stime,
+		       utime + sig->utime, stime + sig->stime,
 		       tsk->se.sum_exec_runtime + sig->sum_sched_runtime);
 }
 
@@ -1226,11 +1239,14 @@ static inline int task_cputime_expired(const struct task_cputime *sample,
 static inline int fastpath_timer_check(struct task_struct *tsk)
 {
 	struct signal_struct *sig;
+	cputime_t utime, stime;
+
+	task_cputime(tsk, &utime, &stime);
 
 	if (!task_cputime_zero(&tsk->cputime_expires)) {
 		struct task_cputime task_sample = {
-			.utime = tsk->utime,
-			.stime = tsk->stime,
+			.utime = utime,
+			.stime = stime,
 			.sum_exec_runtime = tsk->se.sum_exec_runtime
 		};
 
@@ -1401,8 +1417,10 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
 		while (!signal_pending(current)) {
 			if (timer.it.cpu.expires.sched == 0) {
 				/*
-				 * Our timer fired and was reset.
+				 * Our timer fired and was reset, below
+				 * deletion can not fail.
 				 */
+				posix_cpu_timer_del(&timer);
 				spin_unlock_irq(&timer.it_lock);
 				return 0;
 			}
@@ -1420,9 +1438,26 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
 		 * We were interrupted by a signal.
 		 */
 		sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp);
-		posix_cpu_timer_set(&timer, 0, &zero_it, it);
+		error = posix_cpu_timer_set(&timer, 0, &zero_it, it);
+		if (!error) {
+			/*
+			 * Timer is now unarmed, deletion can not fail.
+			 */
+			posix_cpu_timer_del(&timer);
+		}
 		spin_unlock_irq(&timer.it_lock);
 
+		while (error == TIMER_RETRY) {
+			/*
+			 * We need to handle case when timer was or is in the
+			 * middle of firing. In other cases we already freed
+			 * resources.
+			 */
+			spin_lock_irq(&timer.it_lock);
+			error = posix_cpu_timer_del(&timer);
+			spin_unlock_irq(&timer.it_lock);
+		}
+
 		if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
 			/*
 			 * It actually did fire already.
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index 69185ae6b701..6edbb2c55c22 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -552,24 +552,22 @@ SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
 		return -EAGAIN;
 
 	spin_lock_init(&new_timer->it_lock);
- retry:
-	if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
-		error = -EAGAIN;
-		goto out;
-	}
+
+	idr_preload(GFP_KERNEL);
 	spin_lock_irq(&idr_lock);
-	error = idr_get_new(&posix_timers_id, new_timer, &new_timer_id);
+	error = idr_alloc(&posix_timers_id, new_timer, 0, 0, GFP_NOWAIT);
 	spin_unlock_irq(&idr_lock);
-	if (error) {
-		if (error == -EAGAIN)
-			goto retry;
+	idr_preload_end();
+	if (error < 0) {
 		/*
 		 * Weird looking, but we return EAGAIN if the IDR is
 		 * full (proper POSIX return value for this)
 		 */
-		error = -EAGAIN;
+		if (error == -ENOSPC)
+			error = -EAGAIN;
 		goto out;
 	}
+	new_timer_id = error;
 
 	it_id_set = IT_ID_SET;
 	new_timer->it_id = (timer_t) new_timer_id;
@@ -639,6 +637,13 @@ static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
 {
 	struct k_itimer *timr;
 
+	/*
+	 * timer_t could be any type >= int and we want to make sure any
+	 * @timer_id outside positive int range fails lookup.
+	 */
+	if ((unsigned long long)timer_id > INT_MAX)
+		return NULL;
+
 	rcu_read_lock();
 	timr = idr_find(&posix_timers_id, (int)timer_id);
 	if (timr) {
@@ -997,7 +1002,7 @@ SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
 
 	err = kc->clock_adj(which_clock, &ktx);
 
-	if (!err && copy_to_user(utx, &ktx, sizeof(ktx)))
+	if (err >= 0 && copy_to_user(utx, &ktx, sizeof(ktx)))
 		return -EFAULT;
 
 	return err;
diff --git a/kernel/power/autosleep.c b/kernel/power/autosleep.c
index ca304046d9e2..c6422ffeda9a 100644
--- a/kernel/power/autosleep.c
+++ b/kernel/power/autosleep.c
@@ -66,7 +66,7 @@ static DECLARE_WORK(suspend_work, try_to_suspend);
 
 void queue_up_suspend_work(void)
 {
-	if (!work_pending(&suspend_work) && autosleep_state > PM_SUSPEND_ON)
+	if (autosleep_state > PM_SUSPEND_ON)
 		queue_work(autosleep_wq, &suspend_work);
 }
 
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 1c16f9167de1..d77663bfedeb 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -313,7 +313,7 @@ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
 static suspend_state_t decode_state(const char *buf, size_t n)
 {
 #ifdef CONFIG_SUSPEND
-	suspend_state_t state = PM_SUSPEND_STANDBY;
+	suspend_state_t state = PM_SUSPEND_MIN;
 	const char * const *s;
 #endif
 	char *p;
@@ -553,6 +553,30 @@ power_attr(pm_trace_dev_match);
 
 #endif /* CONFIG_PM_TRACE */
 
+#ifdef CONFIG_FREEZER
+static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
+				      struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%u\n", freeze_timeout_msecs);
+}
+
+static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
+				       struct kobj_attribute *attr,
+				       const char *buf, size_t n)
+{
+	unsigned long val;
+
+	if (kstrtoul(buf, 10, &val))
+		return -EINVAL;
+
+	freeze_timeout_msecs = val;
+	return n;
+}
+
+power_attr(pm_freeze_timeout);
+
+#endif	/* CONFIG_FREEZER*/
+
 static struct attribute * g[] = {
 	&state_attr.attr,
 #ifdef CONFIG_PM_TRACE
@@ -576,6 +600,9 @@ static struct attribute * g[] = {
 	&pm_print_times_attr.attr,
 #endif
 #endif
+#ifdef CONFIG_FREEZER
+	&pm_freeze_timeout_attr.attr,
+#endif
 	NULL,
 };
 
diff --git a/kernel/power/process.c b/kernel/power/process.c
index d5a258b60c6f..98088e0e71e8 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -21,7 +21,7 @@
 /* 
  * Timeout for stopping processes
  */
-#define TIMEOUT	(20 * HZ)
+unsigned int __read_mostly freeze_timeout_msecs = 20 * MSEC_PER_SEC;
 
 static int try_to_freeze_tasks(bool user_only)
 {
@@ -36,7 +36,7 @@ static int try_to_freeze_tasks(bool user_only)
 
 	do_gettimeofday(&start);
 
-	end_time = jiffies + TIMEOUT;
+	end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs);
 
 	if (!user_only)
 		freeze_workqueues_begin();
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index 9322ff7eaad6..587dddeebf15 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -359,8 +359,7 @@ void pm_qos_update_request(struct pm_qos_request *req,
 		return;
 	}
 
-	if (delayed_work_pending(&req->work))
-		cancel_delayed_work_sync(&req->work);
+	cancel_delayed_work_sync(&req->work);
 
 	if (new_value != req->node.prio)
 		pm_qos_update_target(
@@ -386,8 +385,7 @@ void pm_qos_update_request_timeout(struct pm_qos_request *req, s32 new_value,
 		 "%s called for unknown object.", __func__))
 		return;
 
-	if (delayed_work_pending(&req->work))
-		cancel_delayed_work_sync(&req->work);
+	cancel_delayed_work_sync(&req->work);
 
 	if (new_value != req->node.prio)
 		pm_qos_update_target(
@@ -416,8 +414,7 @@ void pm_qos_remove_request(struct pm_qos_request *req)
 		return;
 	}
 
-	if (delayed_work_pending(&req->work))
-		cancel_delayed_work_sync(&req->work);
+	cancel_delayed_work_sync(&req->work);
 
 	pm_qos_update_target(pm_qos_array[req->pm_qos_class]->constraints,
 			     &req->node, PM_QOS_REMOVE_REQ,
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index c8b7446b27df..d4feda084a3a 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -30,12 +30,38 @@
 #include "power.h"
 
 const char *const pm_states[PM_SUSPEND_MAX] = {
+	[PM_SUSPEND_FREEZE]	= "freeze",
 	[PM_SUSPEND_STANDBY]	= "standby",
 	[PM_SUSPEND_MEM]	= "mem",
 };
 
 static const struct platform_suspend_ops *suspend_ops;
 
+static bool need_suspend_ops(suspend_state_t state)
+{
+	return !!(state > PM_SUSPEND_FREEZE);
+}
+
+static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
+static bool suspend_freeze_wake;
+
+static void freeze_begin(void)
+{
+	suspend_freeze_wake = false;
+}
+
+static void freeze_enter(void)
+{
+	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
+}
+
+void freeze_wake(void)
+{
+	suspend_freeze_wake = true;
+	wake_up(&suspend_freeze_wait_head);
+}
+EXPORT_SYMBOL_GPL(freeze_wake);
+
 /**
  * suspend_set_ops - Set the global suspend method table.
  * @ops: Suspend operations to use.
@@ -50,8 +76,11 @@ EXPORT_SYMBOL_GPL(suspend_set_ops);
 
 bool valid_state(suspend_state_t state)
 {
+	if (state == PM_SUSPEND_FREEZE)
+		return true;
 	/*
-	 * All states need lowlevel support and need to be valid to the lowlevel
+	 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
+	 * support and need to be valid to the lowlevel
 	 * implementation, no valid callback implies that none are valid.
 	 */
 	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
@@ -89,11 +118,11 @@ static int suspend_test(int level)
  * hibernation).  Run suspend notifiers, allocate the "suspend" console and
  * freeze processes.
  */
-static int suspend_prepare(void)
+static int suspend_prepare(suspend_state_t state)
 {
 	int error;
 
-	if (!suspend_ops || !suspend_ops->enter)
+	if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
 		return -EPERM;
 
 	pm_prepare_console();
@@ -137,7 +166,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 {
 	int error;
 
-	if (suspend_ops->prepare) {
+	if (need_suspend_ops(state) && suspend_ops->prepare) {
 		error = suspend_ops->prepare();
 		if (error)
 			goto Platform_finish;
@@ -149,12 +178,23 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 		goto Platform_finish;
 	}
 
-	if (suspend_ops->prepare_late) {
+	if (need_suspend_ops(state) && suspend_ops->prepare_late) {
 		error = suspend_ops->prepare_late();
 		if (error)
 			goto Platform_wake;
 	}
 
+	/*
+	 * PM_SUSPEND_FREEZE equals
+	 * frozen processes + suspended devices + idle processors.
+	 * Thus we should invoke freeze_enter() soon after
+	 * all the devices are suspended.
+	 */
+	if (state == PM_SUSPEND_FREEZE) {
+		freeze_enter();
+		goto Platform_wake;
+	}
+
 	if (suspend_test(TEST_PLATFORM))
 		goto Platform_wake;
 
@@ -182,13 +222,13 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	enable_nonboot_cpus();
 
  Platform_wake:
-	if (suspend_ops->wake)
+	if (need_suspend_ops(state) && suspend_ops->wake)
 		suspend_ops->wake();
 
 	dpm_resume_start(PMSG_RESUME);
 
  Platform_finish:
-	if (suspend_ops->finish)
+	if (need_suspend_ops(state) && suspend_ops->finish)
 		suspend_ops->finish();
 
 	return error;
@@ -203,11 +243,11 @@ int suspend_devices_and_enter(suspend_state_t state)
 	int error;
 	bool wakeup = false;
 
-	if (!suspend_ops)
+	if (need_suspend_ops(state) && !suspend_ops)
 		return -ENOSYS;
 
 	trace_machine_suspend(state);
-	if (suspend_ops->begin) {
+	if (need_suspend_ops(state) && suspend_ops->begin) {
 		error = suspend_ops->begin(state);
 		if (error)
 			goto Close;
@@ -226,7 +266,7 @@ int suspend_devices_and_enter(suspend_state_t state)
 
 	do {
 		error = suspend_enter(state, &wakeup);
-	} while (!error && !wakeup
+	} while (!error && !wakeup && need_suspend_ops(state)
 		&& suspend_ops->suspend_again && suspend_ops->suspend_again());
 
  Resume_devices:
@@ -236,13 +276,13 @@ int suspend_devices_and_enter(suspend_state_t state)
 	ftrace_start();
 	resume_console();
  Close:
-	if (suspend_ops->end)
+	if (need_suspend_ops(state) && suspend_ops->end)
 		suspend_ops->end();
 	trace_machine_suspend(PWR_EVENT_EXIT);
 	return error;
 
  Recover_platform:
-	if (suspend_ops->recover)
+	if (need_suspend_ops(state) && suspend_ops->recover)
 		suspend_ops->recover();
 	goto Resume_devices;
 }
@@ -278,12 +318,15 @@ static int enter_state(suspend_state_t state)
 	if (!mutex_trylock(&pm_mutex))
 		return -EBUSY;
 
+	if (state == PM_SUSPEND_FREEZE)
+		freeze_begin();
+
 	printk(KERN_INFO "PM: Syncing filesystems ... ");
 	sys_sync();
 	printk("done.\n");
 
 	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
-	error = suspend_prepare();
+	error = suspend_prepare(state);
 	if (error)
 		goto Unlock;
 
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
index 25596e450ac7..9b2a1d58558d 100644
--- a/kernel/power/suspend_test.c
+++ b/kernel/power/suspend_test.c
@@ -112,7 +112,7 @@ static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
 	rtc_set_alarm(rtc, &alm);
 }
 
-static int __init has_wakealarm(struct device *dev, void *name_ptr)
+static int __init has_wakealarm(struct device *dev, const void *data)
 {
 	struct rtc_device *candidate = to_rtc_device(dev);
 
@@ -121,7 +121,6 @@ static int __init has_wakealarm(struct device *dev, void *name_ptr)
 	if (!device_may_wakeup(candidate->dev.parent))
 		return 0;
 
-	*(const char **)name_ptr = dev_name(dev);
 	return 1;
 }
 
@@ -159,8 +158,8 @@ static int __init test_suspend(void)
 	static char		warn_no_rtc[] __initdata =
 		KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n";
 
-	char			*pony = NULL;
 	struct rtc_device	*rtc = NULL;
+	struct device		*dev;
 
 	/* PM is initialized by now; is that state testable? */
 	if (test_state == PM_SUSPEND_ON)
@@ -171,9 +170,9 @@ static int __init test_suspend(void)
 	}
 
 	/* RTCs have initialized by now too ... can we use one? */
-	class_find_device(rtc_class, NULL, &pony, has_wakealarm);
-	if (pony)
-		rtc = rtc_class_open(pony);
+	dev = class_find_device(rtc_class, NULL, NULL, has_wakealarm);
+	if (dev)
+		rtc = rtc_class_open(dev_name(dev));
 	if (!rtc) {
 		printk(warn_no_rtc);
 		goto done;
diff --git a/kernel/printk.c b/kernel/printk.c
index 357f714ddd49..0b31715f335a 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -42,6 +42,7 @@
 #include <linux/notifier.h>
 #include <linux/rculist.h>
 #include <linux/poll.h>
+#include <linux/irq_work.h>
 
 #include <asm/uaccess.h>
 
@@ -1967,30 +1968,32 @@ int is_console_locked(void)
 static DEFINE_PER_CPU(int, printk_pending);
 static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf);
 
-void printk_tick(void)
+static void wake_up_klogd_work_func(struct irq_work *irq_work)
 {
-	if (__this_cpu_read(printk_pending)) {
-		int pending = __this_cpu_xchg(printk_pending, 0);
-		if (pending & PRINTK_PENDING_SCHED) {
-			char *buf = __get_cpu_var(printk_sched_buf);
-			printk(KERN_WARNING "[sched_delayed] %s", buf);
-		}
-		if (pending & PRINTK_PENDING_WAKEUP)
-			wake_up_interruptible(&log_wait);
+	int pending = __this_cpu_xchg(printk_pending, 0);
+
+	if (pending & PRINTK_PENDING_SCHED) {
+		char *buf = __get_cpu_var(printk_sched_buf);
+		printk(KERN_WARNING "[sched_delayed] %s", buf);
 	}
-}
 
-int printk_needs_cpu(int cpu)
-{
-	if (cpu_is_offline(cpu))
-		printk_tick();
-	return __this_cpu_read(printk_pending);
+	if (pending & PRINTK_PENDING_WAKEUP)
+		wake_up_interruptible(&log_wait);
 }
 
+static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = {
+	.func = wake_up_klogd_work_func,
+	.flags = IRQ_WORK_LAZY,
+};
+
 void wake_up_klogd(void)
 {
-	if (waitqueue_active(&log_wait))
+	preempt_disable();
+	if (waitqueue_active(&log_wait)) {
 		this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
+		irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
+	}
+	preempt_enable();
 }
 
 static void console_cont_flush(char *text, size_t size)
@@ -2471,6 +2474,7 @@ int printk_sched(const char *fmt, ...)
 	va_end(args);
 
 	__this_cpu_or(printk_pending, PRINTK_PENDING_SCHED);
+	irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
 	local_irq_restore(flags);
 
 	return r;
diff --git a/kernel/profile.c b/kernel/profile.c
index 1f391819c42f..dc3384ee874e 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -37,9 +37,6 @@ struct profile_hit {
 #define NR_PROFILE_HIT		(PAGE_SIZE/sizeof(struct profile_hit))
 #define NR_PROFILE_GRP		(NR_PROFILE_HIT/PROFILE_GRPSZ)
 
-/* Oprofile timer tick hook */
-static int (*timer_hook)(struct pt_regs *) __read_mostly;
-
 static atomic_t *prof_buffer;
 static unsigned long prof_len, prof_shift;
 
@@ -208,25 +205,6 @@ int profile_event_unregister(enum profile_type type, struct notifier_block *n)
 }
 EXPORT_SYMBOL_GPL(profile_event_unregister);
 
-int register_timer_hook(int (*hook)(struct pt_regs *))
-{
-	if (timer_hook)
-		return -EBUSY;
-	timer_hook = hook;
-	return 0;
-}
-EXPORT_SYMBOL_GPL(register_timer_hook);
-
-void unregister_timer_hook(int (*hook)(struct pt_regs *))
-{
-	WARN_ON(hook != timer_hook);
-	timer_hook = NULL;
-	/* make sure all CPUs see the NULL hook */
-	synchronize_sched();  /* Allow ongoing interrupts to complete. */
-}
-EXPORT_SYMBOL_GPL(unregister_timer_hook);
-
-
 #ifdef CONFIG_SMP
 /*
  * Each cpu has a pair of open-addressed hashtables for pending
@@ -436,8 +414,6 @@ void profile_tick(int type)
 {
 	struct pt_regs *regs = get_irq_regs();
 
-	if (type == CPU_PROFILING && timer_hook)
-		timer_hook(regs);
 	if (!user_mode(regs) && prof_cpu_mask != NULL &&
 	    cpumask_test_cpu(smp_processor_id(), prof_cpu_mask))
 		profile_hit(type, (void *)profile_pc(regs));
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 6cbeaae4406d..acbd28424d81 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -712,6 +712,12 @@ static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
 					     kiov->iov_len, kiov->iov_base);
 }
 
+/*
+ * This is declared in linux/regset.h and defined in machine-dependent
+ * code.  We put the export here, near the primary machine-neutral use,
+ * to ensure no machine forgets it.
+ */
+EXPORT_SYMBOL_GPL(task_user_regset_view);
 #endif
 
 int ptrace_request(struct task_struct *child, long request,
diff --git a/kernel/rcu.h b/kernel/rcu.h
index 20dfba576c2b..7f8e7590e3e5 100644
--- a/kernel/rcu.h
+++ b/kernel/rcu.h
@@ -111,4 +111,11 @@ static inline bool __rcu_reclaim(char *rn, struct rcu_head *head)
 
 extern int rcu_expedited;
 
+#ifdef CONFIG_RCU_STALL_COMMON
+
+extern int rcu_cpu_stall_suppress;
+int rcu_jiffies_till_stall_check(void);
+
+#endif /* #ifdef CONFIG_RCU_STALL_COMMON */
+
 #endif /* __LINUX_RCU_H */
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index a2cf76177b44..48ab70384a4c 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -404,11 +404,65 @@ EXPORT_SYMBOL_GPL(rcuhead_debug_descr);
 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
 
 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU) || defined(CONFIG_RCU_TRACE)
-void do_trace_rcu_torture_read(char *rcutorturename, struct rcu_head *rhp)
+void do_trace_rcu_torture_read(char *rcutorturename, struct rcu_head *rhp,
+			       unsigned long secs,
+			       unsigned long c_old, unsigned long c)
 {
-	trace_rcu_torture_read(rcutorturename, rhp);
+	trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c);
 }
 EXPORT_SYMBOL_GPL(do_trace_rcu_torture_read);
 #else
-#define do_trace_rcu_torture_read(rcutorturename, rhp) do { } while (0)
+#define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
+	do { } while (0)
 #endif
+
+#ifdef CONFIG_RCU_STALL_COMMON
+
+#ifdef CONFIG_PROVE_RCU
+#define RCU_STALL_DELAY_DELTA	       (5 * HZ)
+#else
+#define RCU_STALL_DELAY_DELTA	       0
+#endif
+
+int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */
+int rcu_cpu_stall_timeout __read_mostly = CONFIG_RCU_CPU_STALL_TIMEOUT;
+
+module_param(rcu_cpu_stall_suppress, int, 0644);
+module_param(rcu_cpu_stall_timeout, int, 0644);
+
+int rcu_jiffies_till_stall_check(void)
+{
+	int till_stall_check = ACCESS_ONCE(rcu_cpu_stall_timeout);
+
+	/*
+	 * Limit check must be consistent with the Kconfig limits
+	 * for CONFIG_RCU_CPU_STALL_TIMEOUT.
+	 */
+	if (till_stall_check < 3) {
+		ACCESS_ONCE(rcu_cpu_stall_timeout) = 3;
+		till_stall_check = 3;
+	} else if (till_stall_check > 300) {
+		ACCESS_ONCE(rcu_cpu_stall_timeout) = 300;
+		till_stall_check = 300;
+	}
+	return till_stall_check * HZ + RCU_STALL_DELAY_DELTA;
+}
+
+static int rcu_panic(struct notifier_block *this, unsigned long ev, void *ptr)
+{
+	rcu_cpu_stall_suppress = 1;
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block rcu_panic_block = {
+	.notifier_call = rcu_panic,
+};
+
+static int __init check_cpu_stall_init(void)
+{
+	atomic_notifier_chain_register(&panic_notifier_list, &rcu_panic_block);
+	return 0;
+}
+early_initcall(check_cpu_stall_init);
+
+#endif /* #ifdef CONFIG_RCU_STALL_COMMON */
diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index e7dce58f9c2a..a0714a51b6d7 100644
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -51,10 +51,10 @@ static void __call_rcu(struct rcu_head *head,
 		       void (*func)(struct rcu_head *rcu),
 		       struct rcu_ctrlblk *rcp);
 
-#include "rcutiny_plugin.h"
-
 static long long rcu_dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
 
+#include "rcutiny_plugin.h"
+
 /* Common code for rcu_idle_enter() and rcu_irq_exit(), see kernel/rcutree.c. */
 static void rcu_idle_enter_common(long long newval)
 {
@@ -193,7 +193,7 @@ EXPORT_SYMBOL(rcu_is_cpu_idle);
  * interrupts don't count, we must be running at the first interrupt
  * level.
  */
-int rcu_is_cpu_rrupt_from_idle(void)
+static int rcu_is_cpu_rrupt_from_idle(void)
 {
 	return rcu_dynticks_nesting <= 1;
 }
@@ -205,6 +205,7 @@ int rcu_is_cpu_rrupt_from_idle(void)
  */
 static int rcu_qsctr_help(struct rcu_ctrlblk *rcp)
 {
+	reset_cpu_stall_ticks(rcp);
 	if (rcp->rcucblist != NULL &&
 	    rcp->donetail != rcp->curtail) {
 		rcp->donetail = rcp->curtail;
@@ -251,6 +252,7 @@ void rcu_bh_qs(int cpu)
  */
 void rcu_check_callbacks(int cpu, int user)
 {
+	check_cpu_stalls();
 	if (user || rcu_is_cpu_rrupt_from_idle())
 		rcu_sched_qs(cpu);
 	else if (!in_softirq())
diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h
index f85016a2309b..8a233002faeb 100644
--- a/kernel/rcutiny_plugin.h
+++ b/kernel/rcutiny_plugin.h
@@ -33,6 +33,9 @@ struct rcu_ctrlblk {
 	struct rcu_head **donetail;	/* ->next pointer of last "done" CB. */
 	struct rcu_head **curtail;	/* ->next pointer of last CB. */
 	RCU_TRACE(long qlen);		/* Number of pending CBs. */
+	RCU_TRACE(unsigned long gp_start); /* Start time for stalls. */
+	RCU_TRACE(unsigned long ticks_this_gp); /* Statistic for stalls. */
+	RCU_TRACE(unsigned long jiffies_stall); /* Jiffies at next stall. */
 	RCU_TRACE(char *name);		/* Name of RCU type. */
 };
 
@@ -54,6 +57,51 @@ int rcu_scheduler_active __read_mostly;
 EXPORT_SYMBOL_GPL(rcu_scheduler_active);
 #endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
 
+#ifdef CONFIG_RCU_TRACE
+
+static void check_cpu_stall(struct rcu_ctrlblk *rcp)
+{
+	unsigned long j;
+	unsigned long js;
+
+	if (rcu_cpu_stall_suppress)
+		return;
+	rcp->ticks_this_gp++;
+	j = jiffies;
+	js = rcp->jiffies_stall;
+	if (*rcp->curtail && ULONG_CMP_GE(j, js)) {
+		pr_err("INFO: %s stall on CPU (%lu ticks this GP) idle=%llx (t=%lu jiffies q=%ld)\n",
+		       rcp->name, rcp->ticks_this_gp, rcu_dynticks_nesting,
+		       jiffies - rcp->gp_start, rcp->qlen);
+		dump_stack();
+	}
+	if (*rcp->curtail && ULONG_CMP_GE(j, js))
+		rcp->jiffies_stall = jiffies +
+			3 * rcu_jiffies_till_stall_check() + 3;
+	else if (ULONG_CMP_GE(j, js))
+		rcp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check();
+}
+
+static void check_cpu_stall_preempt(void);
+
+#endif /* #ifdef CONFIG_RCU_TRACE */
+
+static void reset_cpu_stall_ticks(struct rcu_ctrlblk *rcp)
+{
+#ifdef CONFIG_RCU_TRACE
+	rcp->ticks_this_gp = 0;
+	rcp->gp_start = jiffies;
+	rcp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check();
+#endif /* #ifdef CONFIG_RCU_TRACE */
+}
+
+static void check_cpu_stalls(void)
+{
+	RCU_TRACE(check_cpu_stall(&rcu_bh_ctrlblk));
+	RCU_TRACE(check_cpu_stall(&rcu_sched_ctrlblk));
+	RCU_TRACE(check_cpu_stall_preempt());
+}
+
 #ifdef CONFIG_TINY_PREEMPT_RCU
 
 #include <linux/delay.h>
@@ -448,6 +496,7 @@ static void rcu_preempt_start_gp(void)
 		/* Official start of GP. */
 		rcu_preempt_ctrlblk.gpnum++;
 		RCU_TRACE(rcu_preempt_ctrlblk.n_grace_periods++);
+		reset_cpu_stall_ticks(&rcu_preempt_ctrlblk.rcb);
 
 		/* Any blocked RCU readers block new GP. */
 		if (rcu_preempt_blocked_readers_any())
@@ -1054,4 +1103,11 @@ MODULE_AUTHOR("Paul E. McKenney");
 MODULE_DESCRIPTION("Read-Copy Update tracing for tiny implementation");
 MODULE_LICENSE("GPL");
 
+static void check_cpu_stall_preempt(void)
+{
+#ifdef CONFIG_TINY_PREEMPT_RCU
+	check_cpu_stall(&rcu_preempt_ctrlblk.rcb);
+#endif /* #ifdef CONFIG_TINY_PREEMPT_RCU */
+}
+
 #endif /* #ifdef CONFIG_RCU_TRACE */
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 31dea01c85fd..e1f3a8c96724 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -46,6 +46,7 @@
 #include <linux/stat.h>
 #include <linux/srcu.h>
 #include <linux/slab.h>
+#include <linux/trace_clock.h>
 #include <asm/byteorder.h>
 
 MODULE_LICENSE("GPL");
@@ -207,6 +208,20 @@ MODULE_PARM_DESC(rcutorture_runnable, "Start rcutorture at boot");
 #define rcu_can_boost() 0
 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
 
+#ifdef CONFIG_RCU_TRACE
+static u64 notrace rcu_trace_clock_local(void)
+{
+	u64 ts = trace_clock_local();
+	unsigned long __maybe_unused ts_rem = do_div(ts, NSEC_PER_USEC);
+	return ts;
+}
+#else /* #ifdef CONFIG_RCU_TRACE */
+static u64 notrace rcu_trace_clock_local(void)
+{
+	return 0ULL;
+}
+#endif /* #else #ifdef CONFIG_RCU_TRACE */
+
 static unsigned long shutdown_time;	/* jiffies to system shutdown. */
 static unsigned long boost_starttime;	/* jiffies of next boost test start. */
 DEFINE_MUTEX(boost_mutex);		/* protect setting boost_starttime */
@@ -845,7 +860,7 @@ static int rcu_torture_boost(void *arg)
 		/* Wait for the next test interval. */
 		oldstarttime = boost_starttime;
 		while (ULONG_CMP_LT(jiffies, oldstarttime)) {
-			schedule_timeout_uninterruptible(1);
+			schedule_timeout_interruptible(oldstarttime - jiffies);
 			rcu_stutter_wait("rcu_torture_boost");
 			if (kthread_should_stop() ||
 			    fullstop != FULLSTOP_DONTSTOP)
@@ -1028,7 +1043,6 @@ void rcutorture_trace_dump(void)
 		return;
 	if (atomic_xchg(&beenhere, 1) != 0)
 		return;
-	do_trace_rcu_torture_read(cur_ops->name, (struct rcu_head *)~0UL);
 	ftrace_dump(DUMP_ALL);
 }
 
@@ -1042,13 +1056,16 @@ static void rcu_torture_timer(unsigned long unused)
 {
 	int idx;
 	int completed;
+	int completed_end;
 	static DEFINE_RCU_RANDOM(rand);
 	static DEFINE_SPINLOCK(rand_lock);
 	struct rcu_torture *p;
 	int pipe_count;
+	unsigned long long ts;
 
 	idx = cur_ops->readlock();
 	completed = cur_ops->completed();
+	ts = rcu_trace_clock_local();
 	p = rcu_dereference_check(rcu_torture_current,
 				  rcu_read_lock_bh_held() ||
 				  rcu_read_lock_sched_held() ||
@@ -1058,7 +1075,6 @@ static void rcu_torture_timer(unsigned long unused)
 		cur_ops->readunlock(idx);
 		return;
 	}
-	do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu);
 	if (p->rtort_mbtest == 0)
 		atomic_inc(&n_rcu_torture_mberror);
 	spin_lock(&rand_lock);
@@ -1071,10 +1087,14 @@ static void rcu_torture_timer(unsigned long unused)
 		/* Should not happen, but... */
 		pipe_count = RCU_TORTURE_PIPE_LEN;
 	}
-	if (pipe_count > 1)
+	completed_end = cur_ops->completed();
+	if (pipe_count > 1) {
+		do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts,
+					  completed, completed_end);
 		rcutorture_trace_dump();
+	}
 	__this_cpu_inc(rcu_torture_count[pipe_count]);
-	completed = cur_ops->completed() - completed;
+	completed = completed_end - completed;
 	if (completed > RCU_TORTURE_PIPE_LEN) {
 		/* Should not happen, but... */
 		completed = RCU_TORTURE_PIPE_LEN;
@@ -1094,11 +1114,13 @@ static int
 rcu_torture_reader(void *arg)
 {
 	int completed;
+	int completed_end;
 	int idx;
 	DEFINE_RCU_RANDOM(rand);
 	struct rcu_torture *p;
 	int pipe_count;
 	struct timer_list t;
+	unsigned long long ts;
 
 	VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
 	set_user_nice(current, 19);
@@ -1112,6 +1134,7 @@ rcu_torture_reader(void *arg)
 		}
 		idx = cur_ops->readlock();
 		completed = cur_ops->completed();
+		ts = rcu_trace_clock_local();
 		p = rcu_dereference_check(rcu_torture_current,
 					  rcu_read_lock_bh_held() ||
 					  rcu_read_lock_sched_held() ||
@@ -1122,7 +1145,6 @@ rcu_torture_reader(void *arg)
 			schedule_timeout_interruptible(HZ);
 			continue;
 		}
-		do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu);
 		if (p->rtort_mbtest == 0)
 			atomic_inc(&n_rcu_torture_mberror);
 		cur_ops->read_delay(&rand);
@@ -1132,10 +1154,14 @@ rcu_torture_reader(void *arg)
 			/* Should not happen, but... */
 			pipe_count = RCU_TORTURE_PIPE_LEN;
 		}
-		if (pipe_count > 1)
+		completed_end = cur_ops->completed();
+		if (pipe_count > 1) {
+			do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
+						  ts, completed, completed_end);
 			rcutorture_trace_dump();
+		}
 		__this_cpu_inc(rcu_torture_count[pipe_count]);
-		completed = cur_ops->completed() - completed;
+		completed = completed_end - completed;
 		if (completed > RCU_TORTURE_PIPE_LEN) {
 			/* Should not happen, but... */
 			completed = RCU_TORTURE_PIPE_LEN;
@@ -1301,19 +1327,35 @@ static void rcu_torture_shuffle_tasks(void)
 				set_cpus_allowed_ptr(reader_tasks[i],
 						     shuffle_tmp_mask);
 	}
-
 	if (fakewriter_tasks) {
 		for (i = 0; i < nfakewriters; i++)
 			if (fakewriter_tasks[i])
 				set_cpus_allowed_ptr(fakewriter_tasks[i],
 						     shuffle_tmp_mask);
 	}
-
 	if (writer_task)
 		set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask);
-
 	if (stats_task)
 		set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask);
+	if (stutter_task)
+		set_cpus_allowed_ptr(stutter_task, shuffle_tmp_mask);
+	if (fqs_task)
+		set_cpus_allowed_ptr(fqs_task, shuffle_tmp_mask);
+	if (shutdown_task)
+		set_cpus_allowed_ptr(shutdown_task, shuffle_tmp_mask);
+#ifdef CONFIG_HOTPLUG_CPU
+	if (onoff_task)
+		set_cpus_allowed_ptr(onoff_task, shuffle_tmp_mask);
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+	if (stall_task)
+		set_cpus_allowed_ptr(stall_task, shuffle_tmp_mask);
+	if (barrier_cbs_tasks)
+		for (i = 0; i < n_barrier_cbs; i++)
+			if (barrier_cbs_tasks[i])
+				set_cpus_allowed_ptr(barrier_cbs_tasks[i],
+						     shuffle_tmp_mask);
+	if (barrier_task)
+		set_cpus_allowed_ptr(barrier_task, shuffle_tmp_mask);
 
 	if (rcu_idle_cpu == -1)
 		rcu_idle_cpu = num_online_cpus() - 1;
@@ -1749,7 +1791,7 @@ static int rcu_torture_barrier_init(void)
 	barrier_cbs_wq =
 		kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]),
 			GFP_KERNEL);
-	if (barrier_cbs_tasks == NULL || barrier_cbs_wq == 0)
+	if (barrier_cbs_tasks == NULL || !barrier_cbs_wq)
 		return -ENOMEM;
 	for (i = 0; i < n_barrier_cbs; i++) {
 		init_waitqueue_head(&barrier_cbs_wq[i]);
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index e441b77b614e..5b8ad827fd86 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -105,7 +105,7 @@ int rcu_num_nodes __read_mostly = NUM_RCU_NODES; /* Total # rcu_nodes in use. */
  * The rcu_scheduler_active variable transitions from zero to one just
  * before the first task is spawned.  So when this variable is zero, RCU
  * can assume that there is but one task, allowing RCU to (for example)
- * optimized synchronize_sched() to a simple barrier().  When this variable
+ * optimize synchronize_sched() to a simple barrier().  When this variable
  * is one, RCU must actually do all the hard work required to detect real
  * grace periods.  This variable is also used to suppress boot-time false
  * positives from lockdep-RCU error checking.
@@ -217,12 +217,6 @@ module_param(blimit, long, 0444);
 module_param(qhimark, long, 0444);
 module_param(qlowmark, long, 0444);
 
-int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */
-int rcu_cpu_stall_timeout __read_mostly = CONFIG_RCU_CPU_STALL_TIMEOUT;
-
-module_param(rcu_cpu_stall_suppress, int, 0644);
-module_param(rcu_cpu_stall_timeout, int, 0644);
-
 static ulong jiffies_till_first_fqs = RCU_JIFFIES_TILL_FORCE_QS;
 static ulong jiffies_till_next_fqs = RCU_JIFFIES_TILL_FORCE_QS;
 
@@ -305,17 +299,27 @@ cpu_has_callbacks_ready_to_invoke(struct rcu_data *rdp)
 }
 
 /*
- * Does the current CPU require a yet-as-unscheduled grace period?
+ * Does the current CPU require a not-yet-started grace period?
+ * The caller must have disabled interrupts to prevent races with
+ * normal callback registry.
  */
 static int
 cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp)
 {
-	struct rcu_head **ntp;
+	int i;
 
-	ntp = rdp->nxttail[RCU_DONE_TAIL +
-			   (ACCESS_ONCE(rsp->completed) != rdp->completed)];
-	return rdp->nxttail[RCU_DONE_TAIL] && ntp && *ntp &&
-	       !rcu_gp_in_progress(rsp);
+	if (rcu_gp_in_progress(rsp))
+		return 0;  /* No, a grace period is already in progress. */
+	if (!rdp->nxttail[RCU_NEXT_TAIL])
+		return 0;  /* No, this is a no-CBs (or offline) CPU. */
+	if (*rdp->nxttail[RCU_NEXT_READY_TAIL])
+		return 1;  /* Yes, this CPU has newly registered callbacks. */
+	for (i = RCU_WAIT_TAIL; i < RCU_NEXT_TAIL; i++)
+		if (rdp->nxttail[i - 1] != rdp->nxttail[i] &&
+		    ULONG_CMP_LT(ACCESS_ONCE(rsp->completed),
+				 rdp->nxtcompleted[i]))
+			return 1;  /* Yes, CBs for future grace period. */
+	return 0; /* No grace period needed. */
 }
 
 /*
@@ -336,7 +340,7 @@ static struct rcu_node *rcu_get_root(struct rcu_state *rsp)
 static void rcu_eqs_enter_common(struct rcu_dynticks *rdtp, long long oldval,
 				bool user)
 {
-	trace_rcu_dyntick("Start", oldval, 0);
+	trace_rcu_dyntick("Start", oldval, rdtp->dynticks_nesting);
 	if (!user && !is_idle_task(current)) {
 		struct task_struct *idle = idle_task(smp_processor_id());
 
@@ -727,7 +731,7 @@ EXPORT_SYMBOL_GPL(rcu_lockdep_current_cpu_online);
  * interrupt from idle, return true.  The caller must have at least
  * disabled preemption.
  */
-int rcu_is_cpu_rrupt_from_idle(void)
+static int rcu_is_cpu_rrupt_from_idle(void)
 {
 	return __get_cpu_var(rcu_dynticks).dynticks_nesting <= 1;
 }
@@ -793,28 +797,10 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
 	return 0;
 }
 
-static int jiffies_till_stall_check(void)
-{
-	int till_stall_check = ACCESS_ONCE(rcu_cpu_stall_timeout);
-
-	/*
-	 * Limit check must be consistent with the Kconfig limits
-	 * for CONFIG_RCU_CPU_STALL_TIMEOUT.
-	 */
-	if (till_stall_check < 3) {
-		ACCESS_ONCE(rcu_cpu_stall_timeout) = 3;
-		till_stall_check = 3;
-	} else if (till_stall_check > 300) {
-		ACCESS_ONCE(rcu_cpu_stall_timeout) = 300;
-		till_stall_check = 300;
-	}
-	return till_stall_check * HZ + RCU_STALL_DELAY_DELTA;
-}
-
 static void record_gp_stall_check_time(struct rcu_state *rsp)
 {
 	rsp->gp_start = jiffies;
-	rsp->jiffies_stall = jiffies + jiffies_till_stall_check();
+	rsp->jiffies_stall = jiffies + rcu_jiffies_till_stall_check();
 }
 
 /*
@@ -857,7 +843,7 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
 		raw_spin_unlock_irqrestore(&rnp->lock, flags);
 		return;
 	}
-	rsp->jiffies_stall = jiffies + 3 * jiffies_till_stall_check() + 3;
+	rsp->jiffies_stall = jiffies + 3 * rcu_jiffies_till_stall_check() + 3;
 	raw_spin_unlock_irqrestore(&rnp->lock, flags);
 
 	/*
@@ -935,7 +921,7 @@ static void print_cpu_stall(struct rcu_state *rsp)
 	raw_spin_lock_irqsave(&rnp->lock, flags);
 	if (ULONG_CMP_GE(jiffies, rsp->jiffies_stall))
 		rsp->jiffies_stall = jiffies +
-				     3 * jiffies_till_stall_check() + 3;
+				     3 * rcu_jiffies_till_stall_check() + 3;
 	raw_spin_unlock_irqrestore(&rnp->lock, flags);
 
 	set_need_resched();  /* kick ourselves to get things going. */
@@ -966,12 +952,6 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
 	}
 }
 
-static int rcu_panic(struct notifier_block *this, unsigned long ev, void *ptr)
-{
-	rcu_cpu_stall_suppress = 1;
-	return NOTIFY_DONE;
-}
-
 /**
  * rcu_cpu_stall_reset - prevent further stall warnings in current grace period
  *
@@ -989,15 +969,6 @@ void rcu_cpu_stall_reset(void)
 		rsp->jiffies_stall = jiffies + ULONG_MAX / 2;
 }
 
-static struct notifier_block rcu_panic_block = {
-	.notifier_call = rcu_panic,
-};
-
-static void __init check_cpu_stall_init(void)
-{
-	atomic_notifier_chain_register(&panic_notifier_list, &rcu_panic_block);
-}
-
 /*
  * Update CPU-local rcu_data state to record the newly noticed grace period.
  * This is used both when we started the grace period and when we notice
@@ -1071,6 +1042,145 @@ static void init_callback_list(struct rcu_data *rdp)
 }
 
 /*
+ * Determine the value that ->completed will have at the end of the
+ * next subsequent grace period.  This is used to tag callbacks so that
+ * a CPU can invoke callbacks in a timely fashion even if that CPU has
+ * been dyntick-idle for an extended period with callbacks under the
+ * influence of RCU_FAST_NO_HZ.
+ *
+ * The caller must hold rnp->lock with interrupts disabled.
+ */
+static unsigned long rcu_cbs_completed(struct rcu_state *rsp,
+				       struct rcu_node *rnp)
+{
+	/*
+	 * If RCU is idle, we just wait for the next grace period.
+	 * But we can only be sure that RCU is idle if we are looking
+	 * at the root rcu_node structure -- otherwise, a new grace
+	 * period might have started, but just not yet gotten around
+	 * to initializing the current non-root rcu_node structure.
+	 */
+	if (rcu_get_root(rsp) == rnp && rnp->gpnum == rnp->completed)
+		return rnp->completed + 1;
+
+	/*
+	 * Otherwise, wait for a possible partial grace period and
+	 * then the subsequent full grace period.
+	 */
+	return rnp->completed + 2;
+}
+
+/*
+ * If there is room, assign a ->completed number to any callbacks on
+ * this CPU that have not already been assigned.  Also accelerate any
+ * callbacks that were previously assigned a ->completed number that has
+ * since proven to be too conservative, which can happen if callbacks get
+ * assigned a ->completed number while RCU is idle, but with reference to
+ * a non-root rcu_node structure.  This function is idempotent, so it does
+ * not hurt to call it repeatedly.
+ *
+ * The caller must hold rnp->lock with interrupts disabled.
+ */
+static void rcu_accelerate_cbs(struct rcu_state *rsp, struct rcu_node *rnp,
+			       struct rcu_data *rdp)
+{
+	unsigned long c;
+	int i;
+
+	/* If the CPU has no callbacks, nothing to do. */
+	if (!rdp->nxttail[RCU_NEXT_TAIL] || !*rdp->nxttail[RCU_DONE_TAIL])
+		return;
+
+	/*
+	 * Starting from the sublist containing the callbacks most
+	 * recently assigned a ->completed number and working down, find the
+	 * first sublist that is not assignable to an upcoming grace period.
+	 * Such a sublist has something in it (first two tests) and has
+	 * a ->completed number assigned that will complete sooner than
+	 * the ->completed number for newly arrived callbacks (last test).
+	 *
+	 * The key point is that any later sublist can be assigned the
+	 * same ->completed number as the newly arrived callbacks, which
+	 * means that the callbacks in any of these later sublist can be
+	 * grouped into a single sublist, whether or not they have already
+	 * been assigned a ->completed number.
+	 */
+	c = rcu_cbs_completed(rsp, rnp);
+	for (i = RCU_NEXT_TAIL - 1; i > RCU_DONE_TAIL; i--)
+		if (rdp->nxttail[i] != rdp->nxttail[i - 1] &&
+		    !ULONG_CMP_GE(rdp->nxtcompleted[i], c))
+			break;
+
+	/*
+	 * If there are no sublist for unassigned callbacks, leave.
+	 * At the same time, advance "i" one sublist, so that "i" will
+	 * index into the sublist where all the remaining callbacks should
+	 * be grouped into.
+	 */
+	if (++i >= RCU_NEXT_TAIL)
+		return;
+
+	/*
+	 * Assign all subsequent callbacks' ->completed number to the next
+	 * full grace period and group them all in the sublist initially
+	 * indexed by "i".
+	 */
+	for (; i <= RCU_NEXT_TAIL; i++) {
+		rdp->nxttail[i] = rdp->nxttail[RCU_NEXT_TAIL];
+		rdp->nxtcompleted[i] = c;
+	}
+
+	/* Trace depending on how much we were able to accelerate. */
+	if (!*rdp->nxttail[RCU_WAIT_TAIL])
+		trace_rcu_grace_period(rsp->name, rdp->gpnum, "AccWaitCB");
+	else
+		trace_rcu_grace_period(rsp->name, rdp->gpnum, "AccReadyCB");
+}
+
+/*
+ * Move any callbacks whose grace period has completed to the
+ * RCU_DONE_TAIL sublist, then compact the remaining sublists and
+ * assign ->completed numbers to any callbacks in the RCU_NEXT_TAIL
+ * sublist.  This function is idempotent, so it does not hurt to
+ * invoke it repeatedly.  As long as it is not invoked -too- often...
+ *
+ * The caller must hold rnp->lock with interrupts disabled.
+ */
+static void rcu_advance_cbs(struct rcu_state *rsp, struct rcu_node *rnp,
+			    struct rcu_data *rdp)
+{
+	int i, j;
+
+	/* If the CPU has no callbacks, nothing to do. */
+	if (!rdp->nxttail[RCU_NEXT_TAIL] || !*rdp->nxttail[RCU_DONE_TAIL])
+		return;
+
+	/*
+	 * Find all callbacks whose ->completed numbers indicate that they
+	 * are ready to invoke, and put them into the RCU_DONE_TAIL sublist.
+	 */
+	for (i = RCU_WAIT_TAIL; i < RCU_NEXT_TAIL; i++) {
+		if (ULONG_CMP_LT(rnp->completed, rdp->nxtcompleted[i]))
+			break;
+		rdp->nxttail[RCU_DONE_TAIL] = rdp->nxttail[i];
+	}
+	/* Clean up any sublist tail pointers that were misordered above. */
+	for (j = RCU_WAIT_TAIL; j < i; j++)
+		rdp->nxttail[j] = rdp->nxttail[RCU_DONE_TAIL];
+
+	/* Copy down callbacks to fill in empty sublists. */
+	for (j = RCU_WAIT_TAIL; i < RCU_NEXT_TAIL; i++, j++) {
+		if (rdp->nxttail[j] == rdp->nxttail[RCU_NEXT_TAIL])
+			break;
+		rdp->nxttail[j] = rdp->nxttail[i];
+		rdp->nxtcompleted[j] = rdp->nxtcompleted[i];
+	}
+
+	/* Classify any remaining callbacks. */
+	rcu_accelerate_cbs(rsp, rnp, rdp);
+}
+
+/*
  * Advance this CPU's callbacks, but only if the current grace period
  * has ended.  This may be called only from the CPU to whom the rdp
  * belongs.  In addition, the corresponding leaf rcu_node structure's
@@ -1080,12 +1190,15 @@ static void
 __rcu_process_gp_end(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp)
 {
 	/* Did another grace period end? */
-	if (rdp->completed != rnp->completed) {
+	if (rdp->completed == rnp->completed) {
 
-		/* Advance callbacks.  No harm if list empty. */
-		rdp->nxttail[RCU_DONE_TAIL] = rdp->nxttail[RCU_WAIT_TAIL];
-		rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_READY_TAIL];
-		rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
+		/* No, so just accelerate recent callbacks. */
+		rcu_accelerate_cbs(rsp, rnp, rdp);
+
+	} else {
+
+		/* Advance callbacks. */
+		rcu_advance_cbs(rsp, rnp, rdp);
 
 		/* Remember that we saw this grace-period completion. */
 		rdp->completed = rnp->completed;
@@ -1392,17 +1505,10 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
 	/*
 	 * Because there is no grace period in progress right now,
 	 * any callbacks we have up to this point will be satisfied
-	 * by the next grace period.  So promote all callbacks to be
-	 * handled after the end of the next grace period.  If the
-	 * CPU is not yet aware of the end of the previous grace period,
-	 * we need to allow for the callback advancement that will
-	 * occur when it does become aware.  Deadlock prevents us from
-	 * making it aware at this point: We cannot acquire a leaf
-	 * rcu_node ->lock while holding the root rcu_node ->lock.
+	 * by the next grace period.  So this is a good place to
+	 * assign a grace period number to recently posted callbacks.
 	 */
-	rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
-	if (rdp->completed == rsp->completed)
-		rdp->nxttail[RCU_WAIT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
+	rcu_accelerate_cbs(rsp, rnp, rdp);
 
 	rsp->gp_flags = RCU_GP_FLAG_INIT;
 	raw_spin_unlock(&rnp->lock); /* Interrupts remain disabled. */
@@ -1527,7 +1633,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp)
 		 * This GP can't end until cpu checks in, so all of our
 		 * callbacks can be processed during the next GP.
 		 */
-		rdp->nxttail[RCU_NEXT_READY_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
+		rcu_accelerate_cbs(rsp, rnp, rdp);
 
 		rcu_report_qs_rnp(mask, rsp, rnp, flags); /* rlses rnp->lock */
 	}
@@ -1779,7 +1885,7 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
 	long bl, count, count_lazy;
 	int i;
 
-	/* If no callbacks are ready, just return.*/
+	/* If no callbacks are ready, just return. */
 	if (!cpu_has_callbacks_ready_to_invoke(rdp)) {
 		trace_rcu_batch_start(rsp->name, rdp->qlen_lazy, rdp->qlen, 0);
 		trace_rcu_batch_end(rsp->name, 0, !!ACCESS_ONCE(rdp->nxtlist),
@@ -2008,19 +2114,19 @@ __rcu_process_callbacks(struct rcu_state *rsp)
 
 	WARN_ON_ONCE(rdp->beenonline == 0);
 
-	/*
-	 * Advance callbacks in response to end of earlier grace
-	 * period that some other CPU ended.
-	 */
+	/* Handle the end of a grace period that some other CPU ended.  */
 	rcu_process_gp_end(rsp, rdp);
 
 	/* Update RCU state based on any recent quiescent states. */
 	rcu_check_quiescent_state(rsp, rdp);
 
 	/* Does this CPU require a not-yet-started grace period? */
+	local_irq_save(flags);
 	if (cpu_needs_another_gp(rsp, rdp)) {
-		raw_spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags);
+		raw_spin_lock(&rcu_get_root(rsp)->lock); /* irqs disabled. */
 		rcu_start_gp(rsp, flags);  /* releases above lock */
+	} else {
+		local_irq_restore(flags);
 	}
 
 	/* If there are callbacks ready, invoke them. */
@@ -2719,9 +2825,6 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
 	rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
 	WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != DYNTICK_TASK_EXIT_IDLE);
 	WARN_ON_ONCE(atomic_read(&rdp->dynticks->dynticks) != 1);
-#ifdef CONFIG_RCU_USER_QS
-	WARN_ON_ONCE(rdp->dynticks->in_user);
-#endif
 	rdp->cpu = cpu;
 	rdp->rsp = rsp;
 	rcu_boot_init_nocb_percpu_data(rdp);
@@ -2938,6 +3041,10 @@ static void __init rcu_init_one(struct rcu_state *rsp,
 
 	BUILD_BUG_ON(MAX_RCU_LVLS > ARRAY_SIZE(buf));  /* Fix buf[] init! */
 
+	/* Silence gcc 4.8 warning about array index out of range. */
+	if (rcu_num_lvls > RCU_NUM_LVLS)
+		panic("rcu_init_one: rcu_num_lvls overflow");
+
 	/* Initialize the level-tracking arrays. */
 
 	for (i = 0; i < rcu_num_lvls; i++)
@@ -3074,7 +3181,6 @@ void __init rcu_init(void)
 	cpu_notifier(rcu_cpu_notify, 0);
 	for_each_online_cpu(cpu)
 		rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
-	check_cpu_stall_init();
 }
 
 #include "rcutree_plugin.h"
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 4b69291b093d..c896b5045d9d 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -102,10 +102,6 @@ struct rcu_dynticks {
 				    /* idle-period nonlazy_posted snapshot. */
 	int tick_nohz_enabled_snap; /* Previously seen value from sysfs. */
 #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */
-#ifdef CONFIG_RCU_USER_QS
-	bool ignore_user_qs;	    /* Treat userspace as extended QS or not */
-	bool in_user;		    /* Is the CPU in userland from RCU POV? */
-#endif
 };
 
 /* RCU's kthread states for tracing. */
@@ -282,6 +278,8 @@ struct rcu_data {
 	 */
 	struct rcu_head *nxtlist;
 	struct rcu_head **nxttail[RCU_NEXT_SIZE];
+	unsigned long	nxtcompleted[RCU_NEXT_SIZE];
+					/* grace periods for sublists. */
 	long		qlen_lazy;	/* # of lazy queued callbacks */
 	long		qlen;		/* # of queued callbacks, incl lazy */
 	long		qlen_last_fqs_check;
@@ -343,11 +341,6 @@ struct rcu_data {
 
 #define RCU_JIFFIES_TILL_FORCE_QS	 3	/* for rsp->jiffies_force_qs */
 
-#ifdef CONFIG_PROVE_RCU
-#define RCU_STALL_DELAY_DELTA	       (5 * HZ)
-#else
-#define RCU_STALL_DELAY_DELTA	       0
-#endif
 #define RCU_STALL_RAT_DELAY		2	/* Allow other CPUs time */
 						/*  to take at least one */
 						/*  scheduling clock irq */
diff --git a/kernel/relay.c b/kernel/relay.c
index e8cd2027abbd..01ab081ac53a 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1139,7 +1139,7 @@ static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos,
 	if (!desc->count)
 		return 0;
 
-	mutex_lock(&filp->f_path.dentry->d_inode->i_mutex);
+	mutex_lock(&file_inode(filp)->i_mutex);
 	do {
 		if (!relay_file_read_avail(buf, *ppos))
 			break;
@@ -1159,7 +1159,7 @@ static ssize_t relay_file_read_subbufs(struct file *filp, loff_t *ppos,
 			*ppos = relay_file_read_end_pos(buf, read_start, ret);
 		}
 	} while (desc->count && ret);
-	mutex_unlock(&filp->f_path.dentry->d_inode->i_mutex);
+	mutex_unlock(&file_inode(filp)->i_mutex);
 
 	return desc->written;
 }
diff --git a/kernel/rtmutex-debug.c b/kernel/rtmutex-debug.c
index 16502d3a71c8..13b243a323fa 100644
--- a/kernel/rtmutex-debug.c
+++ b/kernel/rtmutex-debug.c
@@ -17,6 +17,7 @@
  * See rt.c in preempt-rt for proper credits and further information
  */
 #include <linux/sched.h>
+#include <linux/sched/rt.h>
 #include <linux/delay.h>
 #include <linux/export.h>
 #include <linux/spinlock.h>
diff --git a/kernel/rtmutex-tester.c b/kernel/rtmutex-tester.c
index 98ec49475460..7890b10084a7 100644
--- a/kernel/rtmutex-tester.c
+++ b/kernel/rtmutex-tester.c
@@ -10,6 +10,7 @@
 #include <linux/kthread.h>
 #include <linux/export.h>
 #include <linux/sched.h>
+#include <linux/sched/rt.h>
 #include <linux/spinlock.h>
 #include <linux/timer.h>
 #include <linux/freezer.h>
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index a242e691c993..1e09308bf2a1 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -13,6 +13,7 @@
 #include <linux/spinlock.h>
 #include <linux/export.h>
 #include <linux/sched.h>
+#include <linux/sched/rt.h>
 #include <linux/timer.h>
 
 #include "rtmutex_common.h"
diff --git a/kernel/sched/auto_group.c b/kernel/sched/auto_group.c
index 0984a21076a3..64de5f8b0c9e 100644
--- a/kernel/sched/auto_group.c
+++ b/kernel/sched/auto_group.c
@@ -35,6 +35,7 @@ static inline void autogroup_destroy(struct kref *kref)
 	ag->tg->rt_se = NULL;
 	ag->tg->rt_rq = NULL;
 #endif
+	sched_offline_group(ag->tg);
 	sched_destroy_group(ag->tg);
 }
 
@@ -76,6 +77,8 @@ static inline struct autogroup *autogroup_create(void)
 	if (IS_ERR(tg))
 		goto out_free;
 
+	sched_online_group(tg, &root_task_group);
+
 	kref_init(&ag->kref);
 	init_rwsem(&ag->lock);
 	ag->id = atomic_inc_return(&autogroup_seq_nr);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 26058d0bebba..7f12624a393c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -83,7 +83,7 @@
 #endif
 
 #include "sched.h"
-#include "../workqueue_sched.h"
+#include "../workqueue_internal.h"
 #include "../smpboot.h"
 
 #define CREATE_TRACE_POINTS
@@ -1132,18 +1132,28 @@ EXPORT_SYMBOL_GPL(kick_process);
  */
 static int select_fallback_rq(int cpu, struct task_struct *p)
 {
-	const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu));
+	int nid = cpu_to_node(cpu);
+	const struct cpumask *nodemask = NULL;
 	enum { cpuset, possible, fail } state = cpuset;
 	int dest_cpu;
 
-	/* Look for allowed, online CPU in same node. */
-	for_each_cpu(dest_cpu, nodemask) {
-		if (!cpu_online(dest_cpu))
-			continue;
-		if (!cpu_active(dest_cpu))
-			continue;
-		if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
-			return dest_cpu;
+	/*
+	 * If the node that the cpu is on has been offlined, cpu_to_node()
+	 * will return -1. There is no cpu on the node, and we should
+	 * select the cpu on the other node.
+	 */
+	if (nid != -1) {
+		nodemask = cpumask_of_node(nid);
+
+		/* Look for allowed, online CPU in same node. */
+		for_each_cpu(dest_cpu, nodemask) {
+			if (!cpu_online(dest_cpu))
+				continue;
+			if (!cpu_active(dest_cpu))
+				continue;
+			if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
+				return dest_cpu;
+		}
 	}
 
 	for (;;) {
@@ -1742,9 +1752,8 @@ EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
 static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
 {
 	struct preempt_notifier *notifier;
-	struct hlist_node *node;
 
-	hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
+	hlist_for_each_entry(notifier, &curr->preempt_notifiers, link)
 		notifier->ops->sched_in(notifier, raw_smp_processor_id());
 }
 
@@ -1753,9 +1762,8 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr,
 				 struct task_struct *next)
 {
 	struct preempt_notifier *notifier;
-	struct hlist_node *node;
 
-	hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link)
+	hlist_for_each_entry(notifier, &curr->preempt_notifiers, link)
 		notifier->ops->sched_out(notifier, next);
 }
 
@@ -1969,11 +1977,10 @@ context_switch(struct rq *rq, struct task_struct *prev,
 }
 
 /*
- * nr_running, nr_uninterruptible and nr_context_switches:
+ * nr_running and nr_context_switches:
  *
  * externally visible scheduler statistics: current number of runnable
- * threads, current number of uninterruptible-sleeping threads, total
- * number of context switches performed since bootup.
+ * threads, total number of context switches performed since bootup.
  */
 unsigned long nr_running(void)
 {
@@ -1985,23 +1992,6 @@ unsigned long nr_running(void)
 	return sum;
 }
 
-unsigned long nr_uninterruptible(void)
-{
-	unsigned long i, sum = 0;
-
-	for_each_possible_cpu(i)
-		sum += cpu_rq(i)->nr_uninterruptible;
-
-	/*
-	 * Since we read the counters lockless, it might be slightly
-	 * inaccurate. Do not allow it to go below zero though:
-	 */
-	if (unlikely((long)sum < 0))
-		sum = 0;
-
-	return sum;
-}
-
 unsigned long long nr_context_switches(void)
 {
 	int i;
@@ -2786,7 +2776,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
 	if (irqs_disabled())
 		print_irqtrace_events(prev);
 	dump_stack();
-	add_taint(TAINT_WARN);
+	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
 }
 
 /*
@@ -3268,7 +3258,8 @@ void complete_all(struct completion *x)
 EXPORT_SYMBOL(complete_all);
 
 static inline long __sched
-do_wait_for_common(struct completion *x, long timeout, int state)
+do_wait_for_common(struct completion *x,
+		   long (*action)(long), long timeout, int state)
 {
 	if (!x->done) {
 		DECLARE_WAITQUEUE(wait, current);
@@ -3281,7 +3272,7 @@ do_wait_for_common(struct completion *x, long timeout, int state)
 			}
 			__set_current_state(state);
 			spin_unlock_irq(&x->wait.lock);
-			timeout = schedule_timeout(timeout);
+			timeout = action(timeout);
 			spin_lock_irq(&x->wait.lock);
 		} while (!x->done && timeout);
 		__remove_wait_queue(&x->wait, &wait);
@@ -3292,17 +3283,30 @@ do_wait_for_common(struct completion *x, long timeout, int state)
 	return timeout ?: 1;
 }
 
-static long __sched
-wait_for_common(struct completion *x, long timeout, int state)
+static inline long __sched
+__wait_for_common(struct completion *x,
+		  long (*action)(long), long timeout, int state)
 {
 	might_sleep();
 
 	spin_lock_irq(&x->wait.lock);
-	timeout = do_wait_for_common(x, timeout, state);
+	timeout = do_wait_for_common(x, action, timeout, state);
 	spin_unlock_irq(&x->wait.lock);
 	return timeout;
 }
 
+static long __sched
+wait_for_common(struct completion *x, long timeout, int state)
+{
+	return __wait_for_common(x, schedule_timeout, timeout, state);
+}
+
+static long __sched
+wait_for_common_io(struct completion *x, long timeout, int state)
+{
+	return __wait_for_common(x, io_schedule_timeout, timeout, state);
+}
+
 /**
  * wait_for_completion: - waits for completion of a task
  * @x:  holds the state of this particular completion
@@ -3339,6 +3343,39 @@ wait_for_completion_timeout(struct completion *x, unsigned long timeout)
 EXPORT_SYMBOL(wait_for_completion_timeout);
 
 /**
+ * wait_for_completion_io: - waits for completion of a task
+ * @x:  holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It is NOT
+ * interruptible and there is no timeout. The caller is accounted as waiting
+ * for IO.
+ */
+void __sched wait_for_completion_io(struct completion *x)
+{
+	wait_for_common_io(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion_io);
+
+/**
+ * wait_for_completion_io_timeout: - waits for completion of a task (w/timeout)
+ * @x:  holds the state of this particular completion
+ * @timeout:  timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. The timeout is in jiffies. It is not
+ * interruptible. The caller is accounted as waiting for IO.
+ *
+ * The return value is 0 if timed out, and positive (at least 1, or number of
+ * jiffies left till timeout) if completed.
+ */
+unsigned long __sched
+wait_for_completion_io_timeout(struct completion *x, unsigned long timeout)
+{
+	return wait_for_common_io(x, timeout, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion_io_timeout);
+
+/**
  * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
  * @x:  holds the state of this particular completion
  *
@@ -4364,20 +4401,32 @@ EXPORT_SYMBOL(yield);
  * It's the caller's job to ensure that the target task struct
  * can't go away on us before we can do any checks.
  *
- * Returns true if we indeed boosted the target task.
+ * Returns:
+ *	true (>0) if we indeed boosted the target task.
+ *	false (0) if we failed to boost the target.
+ *	-ESRCH if there's no task to yield to.
  */
 bool __sched yield_to(struct task_struct *p, bool preempt)
 {
 	struct task_struct *curr = current;
 	struct rq *rq, *p_rq;
 	unsigned long flags;
-	bool yielded = 0;
+	int yielded = 0;
 
 	local_irq_save(flags);
 	rq = this_rq();
 
 again:
 	p_rq = task_rq(p);
+	/*
+	 * If we're the only runnable task on the rq and target rq also
+	 * has only one task, there's absolutely no point in yielding.
+	 */
+	if (rq->nr_running == 1 && p_rq->nr_running == 1) {
+		yielded = -ESRCH;
+		goto out_irq;
+	}
+
 	double_rq_lock(rq, p_rq);
 	while (task_rq(p) != p_rq) {
 		double_rq_unlock(rq, p_rq);
@@ -4385,13 +4434,13 @@ again:
 	}
 
 	if (!curr->sched_class->yield_to_task)
-		goto out;
+		goto out_unlock;
 
 	if (curr->sched_class != p->sched_class)
-		goto out;
+		goto out_unlock;
 
 	if (task_running(p_rq, p) || p->state)
-		goto out;
+		goto out_unlock;
 
 	yielded = curr->sched_class->yield_to_task(rq, p, preempt);
 	if (yielded) {
@@ -4404,11 +4453,12 @@ again:
 			resched_task(p_rq->curr);
 	}
 
-out:
+out_unlock:
 	double_rq_unlock(rq, p_rq);
+out_irq:
 	local_irq_restore(flags);
 
-	if (yielded)
+	if (yielded > 0)
 		schedule();
 
 	return yielded;
@@ -4667,6 +4717,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
 	 */
 	idle->sched_class = &idle_sched_class;
 	ftrace_graph_init_idle_task(idle, cpu);
+	vtime_init_idle(idle);
 #if defined(CONFIG_SMP)
 	sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu);
 #endif
@@ -7160,7 +7211,6 @@ static void free_sched_group(struct task_group *tg)
 struct task_group *sched_create_group(struct task_group *parent)
 {
 	struct task_group *tg;
-	unsigned long flags;
 
 	tg = kzalloc(sizeof(*tg), GFP_KERNEL);
 	if (!tg)
@@ -7172,6 +7222,17 @@ struct task_group *sched_create_group(struct task_group *parent)
 	if (!alloc_rt_sched_group(tg, parent))
 		goto err;
 
+	return tg;
+
+err:
+	free_sched_group(tg);
+	return ERR_PTR(-ENOMEM);
+}
+
+void sched_online_group(struct task_group *tg, struct task_group *parent)
+{
+	unsigned long flags;
+
 	spin_lock_irqsave(&task_group_lock, flags);
 	list_add_rcu(&tg->list, &task_groups);
 
@@ -7181,12 +7242,6 @@ struct task_group *sched_create_group(struct task_group *parent)
 	INIT_LIST_HEAD(&tg->children);
 	list_add_rcu(&tg->siblings, &parent->children);
 	spin_unlock_irqrestore(&task_group_lock, flags);
-
-	return tg;
-
-err:
-	free_sched_group(tg);
-	return ERR_PTR(-ENOMEM);
 }
 
 /* rcu callback to free various structures associated with a task group */
@@ -7199,6 +7254,12 @@ static void free_sched_group_rcu(struct rcu_head *rhp)
 /* Destroy runqueue etc associated with a task group */
 void sched_destroy_group(struct task_group *tg)
 {
+	/* wait for possible concurrent references to cfs_rqs complete */
+	call_rcu(&tg->rcu, free_sched_group_rcu);
+}
+
+void sched_offline_group(struct task_group *tg)
+{
 	unsigned long flags;
 	int i;
 
@@ -7210,9 +7271,6 @@ void sched_destroy_group(struct task_group *tg)
 	list_del_rcu(&tg->list);
 	list_del_rcu(&tg->siblings);
 	spin_unlock_irqrestore(&task_group_lock, flags);
-
-	/* wait for possible concurrent references to cfs_rqs complete */
-	call_rcu(&tg->rcu, free_sched_group_rcu);
 }
 
 /* change task's runqueue when it moves between groups.
@@ -7508,6 +7566,25 @@ static int sched_rt_global_constraints(void)
 }
 #endif /* CONFIG_RT_GROUP_SCHED */
 
+int sched_rr_handler(struct ctl_table *table, int write,
+		void __user *buffer, size_t *lenp,
+		loff_t *ppos)
+{
+	int ret;
+	static DEFINE_MUTEX(mutex);
+
+	mutex_lock(&mutex);
+	ret = proc_dointvec(table, write, buffer, lenp, ppos);
+	/* make sure that internally we keep jiffies */
+	/* also, writing zero resets timeslice to default */
+	if (!ret && write) {
+		sched_rr_timeslice = sched_rr_timeslice <= 0 ?
+			RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice);
+	}
+	mutex_unlock(&mutex);
+	return ret;
+}
+
 int sched_rt_handler(struct ctl_table *table, int write,
 		void __user *buffer, size_t *lenp,
 		loff_t *ppos)
@@ -7564,6 +7641,19 @@ static struct cgroup_subsys_state *cpu_cgroup_css_alloc(struct cgroup *cgrp)
 	return &tg->css;
 }
 
+static int cpu_cgroup_css_online(struct cgroup *cgrp)
+{
+	struct task_group *tg = cgroup_tg(cgrp);
+	struct task_group *parent;
+
+	if (!cgrp->parent)
+		return 0;
+
+	parent = cgroup_tg(cgrp->parent);
+	sched_online_group(tg, parent);
+	return 0;
+}
+
 static void cpu_cgroup_css_free(struct cgroup *cgrp)
 {
 	struct task_group *tg = cgroup_tg(cgrp);
@@ -7571,6 +7661,13 @@ static void cpu_cgroup_css_free(struct cgroup *cgrp)
 	sched_destroy_group(tg);
 }
 
+static void cpu_cgroup_css_offline(struct cgroup *cgrp)
+{
+	struct task_group *tg = cgroup_tg(cgrp);
+
+	sched_offline_group(tg);
+}
+
 static int cpu_cgroup_can_attach(struct cgroup *cgrp,
 				 struct cgroup_taskset *tset)
 {
@@ -7926,6 +8023,8 @@ struct cgroup_subsys cpu_cgroup_subsys = {
 	.name		= "cpu",
 	.css_alloc	= cpu_cgroup_css_alloc,
 	.css_free	= cpu_cgroup_css_free,
+	.css_online	= cpu_cgroup_css_online,
+	.css_offline	= cpu_cgroup_css_offline,
 	.can_attach	= cpu_cgroup_can_attach,
 	.attach		= cpu_cgroup_attach,
 	.exit		= cpu_cgroup_exit,
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c
index 23aa789c53ee..1095e878a46f 100644
--- a/kernel/sched/cpupri.c
+++ b/kernel/sched/cpupri.c
@@ -28,6 +28,8 @@
  */
 
 #include <linux/gfp.h>
+#include <linux/sched.h>
+#include <linux/sched/rt.h>
 #include "cpupri.h"
 
 /* Convert between a 140 based task->prio, and our 102 based cpupri */
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 293b202fcf79..ed12cbb135f4 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -3,6 +3,7 @@
 #include <linux/tsacct_kern.h>
 #include <linux/kernel_stat.h>
 #include <linux/static_key.h>
+#include <linux/context_tracking.h>
 #include "sched.h"
 
 
@@ -163,7 +164,7 @@ void account_user_time(struct task_struct *p, cputime_t cputime,
 	task_group_account_field(p, index, (__force u64) cputime);
 
 	/* Account for user time used */
-	acct_update_integrals(p);
+	acct_account_cputime(p);
 }
 
 /*
@@ -213,7 +214,7 @@ void __account_system_time(struct task_struct *p, cputime_t cputime,
 	task_group_account_field(p, index, (__force u64) cputime);
 
 	/* Account for system time used */
-	acct_update_integrals(p);
+	acct_account_cputime(p);
 }
 
 /*
@@ -295,6 +296,7 @@ static __always_inline bool steal_account_process_tick(void)
 void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
 {
 	struct signal_struct *sig = tsk->signal;
+	cputime_t utime, stime;
 	struct task_struct *t;
 
 	times->utime = sig->utime;
@@ -308,16 +310,15 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
 
 	t = tsk;
 	do {
-		times->utime += t->utime;
-		times->stime += t->stime;
+		task_cputime(tsk, &utime, &stime);
+		times->utime += utime;
+		times->stime += stime;
 		times->sum_exec_runtime += task_sched_runtime(t);
 	} while_each_thread(tsk, t);
 out:
 	rcu_read_unlock();
 }
 
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
-
 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
 /*
  * Account a tick to a process and cpustat
@@ -382,11 +383,12 @@ static void irqtime_account_idle_ticks(int ticks)
 		irqtime_account_process_tick(current, 0, rq);
 }
 #else /* CONFIG_IRQ_TIME_ACCOUNTING */
-static void irqtime_account_idle_ticks(int ticks) {}
-static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
+static inline void irqtime_account_idle_ticks(int ticks) {}
+static inline void irqtime_account_process_tick(struct task_struct *p, int user_tick,
 						struct rq *rq) {}
 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
 
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 /*
  * Account a single tick of cpu time.
  * @p: the process that the cpu time gets accounted to
@@ -397,6 +399,9 @@ void account_process_tick(struct task_struct *p, int user_tick)
 	cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
 	struct rq *rq = this_rq();
 
+	if (vtime_accounting_enabled())
+		return;
+
 	if (sched_clock_irqtime) {
 		irqtime_account_process_tick(p, user_tick, rq);
 		return;
@@ -438,8 +443,7 @@ void account_idle_ticks(unsigned long ticks)
 
 	account_idle_time(jiffies_to_cputime(ticks));
 }
-
-#endif
+#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
 
 /*
  * Use precise platform statistics if available:
@@ -461,25 +465,20 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime
 	*st = cputime.stime;
 }
 
-void vtime_account_system_irqsafe(struct task_struct *tsk)
-{
-	unsigned long flags;
-
-	local_irq_save(flags);
-	vtime_account_system(tsk);
-	local_irq_restore(flags);
-}
-EXPORT_SYMBOL_GPL(vtime_account_system_irqsafe);
-
 #ifndef __ARCH_HAS_VTIME_TASK_SWITCH
 void vtime_task_switch(struct task_struct *prev)
 {
+	if (!vtime_accounting_enabled())
+		return;
+
 	if (is_idle_task(prev))
 		vtime_account_idle(prev);
 	else
 		vtime_account_system(prev);
 
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 	vtime_account_user(prev);
+#endif
 	arch_vtime_task_switch(prev);
 }
 #endif
@@ -493,27 +492,40 @@ void vtime_task_switch(struct task_struct *prev)
  * vtime_account().
  */
 #ifndef __ARCH_HAS_VTIME_ACCOUNT
-void vtime_account(struct task_struct *tsk)
+void vtime_account_irq_enter(struct task_struct *tsk)
 {
-	if (in_interrupt() || !is_idle_task(tsk))
-		vtime_account_system(tsk);
-	else
-		vtime_account_idle(tsk);
+	if (!vtime_accounting_enabled())
+		return;
+
+	if (!in_interrupt()) {
+		/*
+		 * If we interrupted user, context_tracking_in_user()
+		 * is 1 because the context tracking don't hook
+		 * on irq entry/exit. This way we know if
+		 * we need to flush user time on kernel entry.
+		 */
+		if (context_tracking_in_user()) {
+			vtime_account_user(tsk);
+			return;
+		}
+
+		if (is_idle_task(tsk)) {
+			vtime_account_idle(tsk);
+			return;
+		}
+	}
+	vtime_account_system(tsk);
 }
-EXPORT_SYMBOL_GPL(vtime_account);
+EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
 #endif /* __ARCH_HAS_VTIME_ACCOUNT */
 
-#else
-
-#ifndef nsecs_to_cputime
-# define nsecs_to_cputime(__nsecs)	nsecs_to_jiffies(__nsecs)
-#endif
+#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
 
-static cputime_t scale_utime(cputime_t utime, cputime_t rtime, cputime_t total)
+static cputime_t scale_stime(cputime_t stime, cputime_t rtime, cputime_t total)
 {
 	u64 temp = (__force u64) rtime;
 
-	temp *= (__force u64) utime;
+	temp *= (__force u64) stime;
 
 	if (sizeof(cputime_t) == 4)
 		temp = div_u64(temp, (__force u32) total);
@@ -531,10 +543,10 @@ static void cputime_adjust(struct task_cputime *curr,
 			   struct cputime *prev,
 			   cputime_t *ut, cputime_t *st)
 {
-	cputime_t rtime, utime, total;
+	cputime_t rtime, stime, total;
 
-	utime = curr->utime;
-	total = utime + curr->stime;
+	stime = curr->stime;
+	total = stime + curr->utime;
 
 	/*
 	 * Tick based cputime accounting depend on random scheduling
@@ -549,17 +561,17 @@ static void cputime_adjust(struct task_cputime *curr,
 	rtime = nsecs_to_cputime(curr->sum_exec_runtime);
 
 	if (total)
-		utime = scale_utime(utime, rtime, total);
+		stime = scale_stime(stime, rtime, total);
 	else
-		utime = rtime;
+		stime = rtime;
 
 	/*
 	 * If the tick based count grows faster than the scheduler one,
 	 * the result of the scaling may go backward.
 	 * Let's enforce monotonicity.
 	 */
-	prev->utime = max(prev->utime, utime);
-	prev->stime = max(prev->stime, rtime - prev->utime);
+	prev->stime = max(prev->stime, stime);
+	prev->utime = max(prev->utime, rtime - prev->stime);
 
 	*ut = prev->utime;
 	*st = prev->stime;
@@ -568,11 +580,10 @@ static void cputime_adjust(struct task_cputime *curr,
 void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
 {
 	struct task_cputime cputime = {
-		.utime = p->utime,
-		.stime = p->stime,
 		.sum_exec_runtime = p->se.sum_exec_runtime,
 	};
 
+	task_cputime(p, &cputime.utime, &cputime.stime);
 	cputime_adjust(&cputime, &p->prev_cputime, ut, st);
 }
 
@@ -586,4 +597,221 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime
 	thread_group_cputime(p, &cputime);
 	cputime_adjust(&cputime, &p->signal->prev_cputime, ut, st);
 }
-#endif
+#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+static unsigned long long vtime_delta(struct task_struct *tsk)
+{
+	unsigned long long clock;
+
+	clock = local_clock();
+	if (clock < tsk->vtime_snap)
+		return 0;
+
+	return clock - tsk->vtime_snap;
+}
+
+static cputime_t get_vtime_delta(struct task_struct *tsk)
+{
+	unsigned long long delta = vtime_delta(tsk);
+
+	WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_SLEEPING);
+	tsk->vtime_snap += delta;
+
+	/* CHECKME: always safe to convert nsecs to cputime? */
+	return nsecs_to_cputime(delta);
+}
+
+static void __vtime_account_system(struct task_struct *tsk)
+{
+	cputime_t delta_cpu = get_vtime_delta(tsk);
+
+	account_system_time(tsk, irq_count(), delta_cpu, cputime_to_scaled(delta_cpu));
+}
+
+void vtime_account_system(struct task_struct *tsk)
+{
+	if (!vtime_accounting_enabled())
+		return;
+
+	write_seqlock(&tsk->vtime_seqlock);
+	__vtime_account_system(tsk);
+	write_sequnlock(&tsk->vtime_seqlock);
+}
+
+void vtime_account_irq_exit(struct task_struct *tsk)
+{
+	if (!vtime_accounting_enabled())
+		return;
+
+	write_seqlock(&tsk->vtime_seqlock);
+	if (context_tracking_in_user())
+		tsk->vtime_snap_whence = VTIME_USER;
+	__vtime_account_system(tsk);
+	write_sequnlock(&tsk->vtime_seqlock);
+}
+
+void vtime_account_user(struct task_struct *tsk)
+{
+	cputime_t delta_cpu;
+
+	if (!vtime_accounting_enabled())
+		return;
+
+	delta_cpu = get_vtime_delta(tsk);
+
+	write_seqlock(&tsk->vtime_seqlock);
+	tsk->vtime_snap_whence = VTIME_SYS;
+	account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
+	write_sequnlock(&tsk->vtime_seqlock);
+}
+
+void vtime_user_enter(struct task_struct *tsk)
+{
+	if (!vtime_accounting_enabled())
+		return;
+
+	write_seqlock(&tsk->vtime_seqlock);
+	tsk->vtime_snap_whence = VTIME_USER;
+	__vtime_account_system(tsk);
+	write_sequnlock(&tsk->vtime_seqlock);
+}
+
+void vtime_guest_enter(struct task_struct *tsk)
+{
+	write_seqlock(&tsk->vtime_seqlock);
+	__vtime_account_system(tsk);
+	current->flags |= PF_VCPU;
+	write_sequnlock(&tsk->vtime_seqlock);
+}
+
+void vtime_guest_exit(struct task_struct *tsk)
+{
+	write_seqlock(&tsk->vtime_seqlock);
+	__vtime_account_system(tsk);
+	current->flags &= ~PF_VCPU;
+	write_sequnlock(&tsk->vtime_seqlock);
+}
+
+void vtime_account_idle(struct task_struct *tsk)
+{
+	cputime_t delta_cpu = get_vtime_delta(tsk);
+
+	account_idle_time(delta_cpu);
+}
+
+bool vtime_accounting_enabled(void)
+{
+	return context_tracking_active();
+}
+
+void arch_vtime_task_switch(struct task_struct *prev)
+{
+	write_seqlock(&prev->vtime_seqlock);
+	prev->vtime_snap_whence = VTIME_SLEEPING;
+	write_sequnlock(&prev->vtime_seqlock);
+
+	write_seqlock(&current->vtime_seqlock);
+	current->vtime_snap_whence = VTIME_SYS;
+	current->vtime_snap = sched_clock();
+	write_sequnlock(&current->vtime_seqlock);
+}
+
+void vtime_init_idle(struct task_struct *t)
+{
+	unsigned long flags;
+
+	write_seqlock_irqsave(&t->vtime_seqlock, flags);
+	t->vtime_snap_whence = VTIME_SYS;
+	t->vtime_snap = sched_clock();
+	write_sequnlock_irqrestore(&t->vtime_seqlock, flags);
+}
+
+cputime_t task_gtime(struct task_struct *t)
+{
+	unsigned int seq;
+	cputime_t gtime;
+
+	do {
+		seq = read_seqbegin(&t->vtime_seqlock);
+
+		gtime = t->gtime;
+		if (t->flags & PF_VCPU)
+			gtime += vtime_delta(t);
+
+	} while (read_seqretry(&t->vtime_seqlock, seq));
+
+	return gtime;
+}
+
+/*
+ * Fetch cputime raw values from fields of task_struct and
+ * add up the pending nohz execution time since the last
+ * cputime snapshot.
+ */
+static void
+fetch_task_cputime(struct task_struct *t,
+		   cputime_t *u_dst, cputime_t *s_dst,
+		   cputime_t *u_src, cputime_t *s_src,
+		   cputime_t *udelta, cputime_t *sdelta)
+{
+	unsigned int seq;
+	unsigned long long delta;
+
+	do {
+		*udelta = 0;
+		*sdelta = 0;
+
+		seq = read_seqbegin(&t->vtime_seqlock);
+
+		if (u_dst)
+			*u_dst = *u_src;
+		if (s_dst)
+			*s_dst = *s_src;
+
+		/* Task is sleeping, nothing to add */
+		if (t->vtime_snap_whence == VTIME_SLEEPING ||
+		    is_idle_task(t))
+			continue;
+
+		delta = vtime_delta(t);
+
+		/*
+		 * Task runs either in user or kernel space, add pending nohz time to
+		 * the right place.
+		 */
+		if (t->vtime_snap_whence == VTIME_USER || t->flags & PF_VCPU) {
+			*udelta = delta;
+		} else {
+			if (t->vtime_snap_whence == VTIME_SYS)
+				*sdelta = delta;
+		}
+	} while (read_seqretry(&t->vtime_seqlock, seq));
+}
+
+
+void task_cputime(struct task_struct *t, cputime_t *utime, cputime_t *stime)
+{
+	cputime_t udelta, sdelta;
+
+	fetch_task_cputime(t, utime, stime, &t->utime,
+			   &t->stime, &udelta, &sdelta);
+	if (utime)
+		*utime += udelta;
+	if (stime)
+		*stime += sdelta;
+}
+
+void task_cputime_scaled(struct task_struct *t,
+			 cputime_t *utimescaled, cputime_t *stimescaled)
+{
+	cputime_t udelta, sdelta;
+
+	fetch_task_cputime(t, utimescaled, stimescaled,
+			   &t->utimescaled, &t->stimescaled, &udelta, &sdelta);
+	if (utimescaled)
+		*utimescaled += cputime_to_scaled(udelta);
+	if (stimescaled)
+		*stimescaled += cputime_to_scaled(sdelta);
+}
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 7ae4c4c5420e..75024a673520 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -110,13 +110,6 @@ static char *task_group_path(struct task_group *tg)
 	if (autogroup_path(tg, group_path, PATH_MAX))
 		return group_path;
 
-	/*
-	 * May be NULL if the underlying cgroup isn't fully-created yet
-	 */
-	if (!tg->css.cgroup) {
-		group_path[0] = '\0';
-		return group_path;
-	}
 	cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
 	return group_path;
 }
@@ -269,11 +262,11 @@ static void print_cpu(struct seq_file *m, int cpu)
 	{
 		unsigned int freq = cpu_khz ? : 1;
 
-		SEQ_printf(m, "\ncpu#%d, %u.%03u MHz\n",
+		SEQ_printf(m, "cpu#%d, %u.%03u MHz\n",
 			   cpu, freq / 1000, (freq % 1000));
 	}
 #else
-	SEQ_printf(m, "\ncpu#%d\n", cpu);
+	SEQ_printf(m, "cpu#%d\n", cpu);
 #endif
 
 #define P(x)								\
@@ -330,6 +323,7 @@ do {									\
 	print_rq(m, rq, cpu);
 	rcu_read_unlock();
 	spin_unlock_irqrestore(&sched_debug_lock, flags);
+	SEQ_printf(m, "\n");
 }
 
 static const char *sched_tunable_scaling_names[] = {
@@ -338,11 +332,10 @@ static const char *sched_tunable_scaling_names[] = {
 	"linear"
 };
 
-static int sched_debug_show(struct seq_file *m, void *v)
+static void sched_debug_header(struct seq_file *m)
 {
 	u64 ktime, sched_clk, cpu_clk;
 	unsigned long flags;
-	int cpu;
 
 	local_irq_save(flags);
 	ktime = ktime_to_ns(ktime_get());
@@ -384,33 +377,101 @@ static int sched_debug_show(struct seq_file *m, void *v)
 #undef PN
 #undef P
 
-	SEQ_printf(m, "  .%-40s: %d (%s)\n", "sysctl_sched_tunable_scaling",
+	SEQ_printf(m, "  .%-40s: %d (%s)\n",
+		"sysctl_sched_tunable_scaling",
 		sysctl_sched_tunable_scaling,
 		sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
+	SEQ_printf(m, "\n");
+}
 
-	for_each_online_cpu(cpu)
-		print_cpu(m, cpu);
+static int sched_debug_show(struct seq_file *m, void *v)
+{
+	int cpu = (unsigned long)(v - 2);
 
-	SEQ_printf(m, "\n");
+	if (cpu != -1)
+		print_cpu(m, cpu);
+	else
+		sched_debug_header(m);
 
 	return 0;
 }
 
 void sysrq_sched_debug_show(void)
 {
-	sched_debug_show(NULL, NULL);
+	int cpu;
+
+	sched_debug_header(NULL);
+	for_each_online_cpu(cpu)
+		print_cpu(NULL, cpu);
+
+}
+
+/*
+ * This itererator needs some explanation.
+ * It returns 1 for the header position.
+ * This means 2 is cpu 0.
+ * In a hotplugged system some cpus, including cpu 0, may be missing so we have
+ * to use cpumask_* to iterate over the cpus.
+ */
+static void *sched_debug_start(struct seq_file *file, loff_t *offset)
+{
+	unsigned long n = *offset;
+
+	if (n == 0)
+		return (void *) 1;
+
+	n--;
+
+	if (n > 0)
+		n = cpumask_next(n - 1, cpu_online_mask);
+	else
+		n = cpumask_first(cpu_online_mask);
+
+	*offset = n + 1;
+
+	if (n < nr_cpu_ids)
+		return (void *)(unsigned long)(n + 2);
+	return NULL;
+}
+
+static void *sched_debug_next(struct seq_file *file, void *data, loff_t *offset)
+{
+	(*offset)++;
+	return sched_debug_start(file, offset);
+}
+
+static void sched_debug_stop(struct seq_file *file, void *data)
+{
+}
+
+static const struct seq_operations sched_debug_sops = {
+	.start = sched_debug_start,
+	.next = sched_debug_next,
+	.stop = sched_debug_stop,
+	.show = sched_debug_show,
+};
+
+static int sched_debug_release(struct inode *inode, struct file *file)
+{
+	seq_release(inode, file);
+
+	return 0;
 }
 
 static int sched_debug_open(struct inode *inode, struct file *filp)
 {
-	return single_open(filp, sched_debug_show, NULL);
+	int ret = 0;
+
+	ret = seq_open(filp, &sched_debug_sops);
+
+	return ret;
 }
 
 static const struct file_operations sched_debug_fops = {
 	.open		= sched_debug_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
-	.release	= single_release,
+	.release	= sched_debug_release,
 };
 
 static int __init init_sched_debug_procfs(void)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 81fa53643409..7a33e5986fc5 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1680,9 +1680,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 	}
 
 	/* ensure we never gain time by being placed backwards. */
-	vruntime = max_vruntime(se->vruntime, vruntime);
-
-	se->vruntime = vruntime;
+	se->vruntime = max_vruntime(se->vruntime, vruntime);
 }
 
 static void check_enqueue_throttle(struct cfs_rq *cfs_rq);
@@ -3254,25 +3252,18 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
  */
 static int select_idle_sibling(struct task_struct *p, int target)
 {
-	int cpu = smp_processor_id();
-	int prev_cpu = task_cpu(p);
 	struct sched_domain *sd;
 	struct sched_group *sg;
-	int i;
+	int i = task_cpu(p);
 
-	/*
-	 * If the task is going to be woken-up on this cpu and if it is
-	 * already idle, then it is the right target.
-	 */
-	if (target == cpu && idle_cpu(cpu))
-		return cpu;
+	if (idle_cpu(target))
+		return target;
 
 	/*
-	 * If the task is going to be woken-up on the cpu where it previously
-	 * ran and if it is currently idle, then it the right target.
+	 * If the prevous cpu is cache affine and idle, don't be stupid.
 	 */
-	if (target == prev_cpu && idle_cpu(prev_cpu))
-		return prev_cpu;
+	if (i != target && cpus_share_cache(i, target) && idle_cpu(i))
+		return i;
 
 	/*
 	 * Otherwise, iterate the domains and find an elegible idle cpu.
@@ -3286,7 +3277,7 @@ static int select_idle_sibling(struct task_struct *p, int target)
 				goto next;
 
 			for_each_cpu(i, sched_group_cpus(sg)) {
-				if (!idle_cpu(i))
+				if (i == target || !idle_cpu(i))
 					goto next;
 			}
 
@@ -6101,7 +6092,7 @@ static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task
 	 * idle runqueue:
 	 */
 	if (rq->cfs.load.weight)
-		rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
+		rr_interval = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se));
 
 	return rr_interval;
 }
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 4f02b2847357..127a2c4cf4ab 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -7,6 +7,8 @@
 
 #include <linux/slab.h>
 
+int sched_rr_timeslice = RR_TIMESLICE;
+
 static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
 
 struct rt_bandwidth def_rt_bandwidth;
@@ -925,8 +927,8 @@ static void update_curr_rt(struct rq *rq)
 		return;
 
 	delta_exec = rq->clock_task - curr->se.exec_start;
-	if (unlikely((s64)delta_exec < 0))
-		delta_exec = 0;
+	if (unlikely((s64)delta_exec <= 0))
+		return;
 
 	schedstat_set(curr->se.statistics.exec_max,
 		      max(curr->se.statistics.exec_max, delta_exec));
@@ -1427,8 +1429,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p)
 static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
 {
 	if (!task_running(rq, p) &&
-	    (cpu < 0 || cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) &&
-	    (p->nr_cpus_allowed > 1))
+	    cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
 		return 1;
 	return 0;
 }
@@ -1889,8 +1890,11 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p)
 	 * we may need to handle the pulling of RT tasks
 	 * now.
 	 */
-	if (p->on_rq && !rq->rt.rt_nr_running)
-		pull_rt_task(rq);
+	if (!p->on_rq || rq->rt.rt_nr_running)
+		return;
+
+	if (pull_rt_task(rq))
+		resched_task(rq->curr);
 }
 
 void init_sched_rt_class(void)
@@ -1985,7 +1989,11 @@ static void watchdog(struct rq *rq, struct task_struct *p)
 	if (soft != RLIM_INFINITY) {
 		unsigned long next;
 
-		p->rt.timeout++;
+		if (p->rt.watchdog_stamp != jiffies) {
+			p->rt.timeout++;
+			p->rt.watchdog_stamp = jiffies;
+		}
+
 		next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);
 		if (p->rt.timeout > next)
 			p->cputime_expires.sched_exp = p->se.sum_exec_runtime;
@@ -2010,7 +2018,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
 	if (--p->rt.time_slice)
 		return;
 
-	p->rt.time_slice = RR_TIMESLICE;
+	p->rt.time_slice = sched_rr_timeslice;
 
 	/*
 	 * Requeue to the end of queue if we (and all of our ancestors) are the
@@ -2041,7 +2049,7 @@ static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
 	 * Time slice is 0 for SCHED_FIFO tasks
 	 */
 	if (task->policy == SCHED_RR)
-		return RR_TIMESLICE;
+		return sched_rr_timeslice;
 	else
 		return 0;
 }
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index fc886441436a..cc03cfdf469f 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1,5 +1,7 @@
 
 #include <linux/sched.h>
+#include <linux/sched/sysctl.h>
+#include <linux/sched/rt.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
 #include <linux/stop_machine.h>
diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
index 903ffa9e8872..e036eda1a9c9 100644
--- a/kernel/sched/stats.c
+++ b/kernel/sched/stats.c
@@ -21,14 +21,17 @@ static int show_schedstat(struct seq_file *seq, void *v)
 	if (mask_str == NULL)
 		return -ENOMEM;
 
-	seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
-	seq_printf(seq, "timestamp %lu\n", jiffies);
-	for_each_online_cpu(cpu) {
-		struct rq *rq = cpu_rq(cpu);
+	if (v == (void *)1) {
+		seq_printf(seq, "version %d\n", SCHEDSTAT_VERSION);
+		seq_printf(seq, "timestamp %lu\n", jiffies);
+	} else {
+		struct rq *rq;
 #ifdef CONFIG_SMP
 		struct sched_domain *sd;
 		int dcount = 0;
 #endif
+		cpu = (unsigned long)(v - 2);
+		rq = cpu_rq(cpu);
 
 		/* runqueue-specific stats */
 		seq_printf(seq,
@@ -77,30 +80,66 @@ static int show_schedstat(struct seq_file *seq, void *v)
 	return 0;
 }
 
-static int schedstat_open(struct inode *inode, struct file *file)
+/*
+ * This itererator needs some explanation.
+ * It returns 1 for the header position.
+ * This means 2 is cpu 0.
+ * In a hotplugged system some cpus, including cpu 0, may be missing so we have
+ * to use cpumask_* to iterate over the cpus.
+ */
+static void *schedstat_start(struct seq_file *file, loff_t *offset)
 {
-	unsigned int size = PAGE_SIZE * (1 + num_online_cpus() / 32);
-	char *buf = kmalloc(size, GFP_KERNEL);
-	struct seq_file *m;
-	int res;
+	unsigned long n = *offset;
 
-	if (!buf)
-		return -ENOMEM;
-	res = single_open(file, show_schedstat, NULL);
-	if (!res) {
-		m = file->private_data;
-		m->buf = buf;
-		m->size = size;
-	} else
-		kfree(buf);
-	return res;
+	if (n == 0)
+		return (void *) 1;
+
+	n--;
+
+	if (n > 0)
+		n = cpumask_next(n - 1, cpu_online_mask);
+	else
+		n = cpumask_first(cpu_online_mask);
+
+	*offset = n + 1;
+
+	if (n < nr_cpu_ids)
+		return (void *)(unsigned long)(n + 2);
+	return NULL;
+}
+
+static void *schedstat_next(struct seq_file *file, void *data, loff_t *offset)
+{
+	(*offset)++;
+	return schedstat_start(file, offset);
+}
+
+static void schedstat_stop(struct seq_file *file, void *data)
+{
+}
+
+static const struct seq_operations schedstat_sops = {
+	.start = schedstat_start,
+	.next  = schedstat_next,
+	.stop  = schedstat_stop,
+	.show  = show_schedstat,
+};
+
+static int schedstat_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &schedstat_sops);
 }
 
+static int schedstat_release(struct inode *inode, struct file *file)
+{
+	return 0;
+};
+
 static const struct file_operations proc_schedstat_operations = {
 	.open    = schedstat_open,
 	.read    = seq_read,
 	.llseek  = seq_lseek,
-	.release = single_release,
+	.release = schedstat_release,
 };
 
 static int __init proc_schedstat_init(void)
diff --git a/kernel/signal.c b/kernel/signal.c
index 3d09cf6cde75..dd72567767d9 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -485,6 +485,9 @@ flush_signal_handlers(struct task_struct *t, int force_default)
 		if (force_default || ka->sa.sa_handler != SIG_IGN)
 			ka->sa.sa_handler = SIG_DFL;
 		ka->sa.sa_flags = 0;
+#ifdef __ARCH_HAS_SA_RESTORER
+		ka->sa.sa_restorer = NULL;
+#endif
 		sigemptyset(&ka->sa.sa_mask);
 		ka++;
 	}
@@ -1157,11 +1160,11 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
 static void print_fatal_signal(int signr)
 {
 	struct pt_regs *regs = signal_pt_regs();
-	printk("%s/%d: potentially unexpected fatal signal %d.\n",
+	printk(KERN_INFO "%s/%d: potentially unexpected fatal signal %d.\n",
 		current->comm, task_pid_nr(current), signr);
 
 #if defined(__i386__) && !defined(__arch_um__)
-	printk("code at %08lx: ", regs->ip);
+	printk(KERN_INFO "code at %08lx: ", regs->ip);
 	{
 		int i;
 		for (i = 0; i < 16; i++) {
@@ -1169,11 +1172,11 @@ static void print_fatal_signal(int signr)
 
 			if (get_user(insn, (unsigned char *)(regs->ip + i)))
 				break;
-			printk("%02x ", insn);
+			printk(KERN_CONT "%02x ", insn);
 		}
 	}
+	printk(KERN_CONT "\n");
 #endif
-	printk("\n");
 	preempt_disable();
 	show_regs(regs);
 	preempt_enable();
@@ -1632,6 +1635,7 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
 	unsigned long flags;
 	struct sighand_struct *psig;
 	bool autoreap = false;
+	cputime_t utime, stime;
 
 	BUG_ON(sig == -1);
 
@@ -1669,8 +1673,9 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
 				       task_uid(tsk));
 	rcu_read_unlock();
 
-	info.si_utime = cputime_to_clock_t(tsk->utime + tsk->signal->utime);
-	info.si_stime = cputime_to_clock_t(tsk->stime + tsk->signal->stime);
+	task_cputime(tsk, &utime, &stime);
+	info.si_utime = cputime_to_clock_t(utime + tsk->signal->utime);
+	info.si_stime = cputime_to_clock_t(stime + tsk->signal->stime);
 
 	info.si_status = tsk->exit_code & 0x7f;
 	if (tsk->exit_code & 0x80)
@@ -1734,6 +1739,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
 	unsigned long flags;
 	struct task_struct *parent;
 	struct sighand_struct *sighand;
+	cputime_t utime, stime;
 
 	if (for_ptracer) {
 		parent = tsk->parent;
@@ -1752,8 +1758,9 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,
 	info.si_uid = from_kuid_munged(task_cred_xxx(parent, user_ns), task_uid(tsk));
 	rcu_read_unlock();
 
-	info.si_utime = cputime_to_clock_t(tsk->utime);
-	info.si_stime = cputime_to_clock_t(tsk->stime);
+	task_cputime(tsk, &utime, &stime);
+	info.si_utime = cputime_to_clock_t(utime);
+	info.si_stime = cputime_to_clock_t(stime);
 
  	info.si_code = why;
  	switch (why) {
@@ -2395,6 +2402,15 @@ void signal_delivered(int sig, siginfo_t *info, struct k_sigaction *ka,
 	tracehook_signal_handler(sig, info, ka, regs, stepping);
 }
 
+void signal_setup_done(int failed, struct ksignal *ksig, int stepping)
+{
+	if (failed)
+		force_sigsegv(ksig->sig, current);
+	else
+		signal_delivered(ksig->sig, &ksig->info, &ksig->ka,
+			signal_pt_regs(), stepping);
+}
+
 /*
  * It could be that complete_signal() picked us to notify about the
  * group-wide signal. Other threads should be notified now to take
@@ -2612,40 +2628,95 @@ SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset,
 	return 0;
 }
 
-long do_sigpending(void __user *set, unsigned long sigsetsize)
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset,
+		compat_sigset_t __user *, oset, compat_size_t, sigsetsize)
 {
-	long error = -EINVAL;
-	sigset_t pending;
+#ifdef __BIG_ENDIAN
+	sigset_t old_set = current->blocked;
+
+	/* XXX: Don't preclude handling different sized sigset_t's.  */
+	if (sigsetsize != sizeof(sigset_t))
+		return -EINVAL;
+
+	if (nset) {
+		compat_sigset_t new32;
+		sigset_t new_set;
+		int error;
+		if (copy_from_user(&new32, nset, sizeof(compat_sigset_t)))
+			return -EFAULT;
+
+		sigset_from_compat(&new_set, &new32);
+		sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
+
+		error = sigprocmask(how, &new_set, NULL);
+		if (error)
+			return error;
+	}
+	if (oset) {
+		compat_sigset_t old32;
+		sigset_to_compat(&old32, &old_set);
+		if (copy_to_user(oset, &old32, sizeof(compat_sigset_t)))
+			return -EFAULT;
+	}
+	return 0;
+#else
+	return sys_rt_sigprocmask(how, (sigset_t __user *)nset,
+				  (sigset_t __user *)oset, sigsetsize);
+#endif
+}
+#endif
 
+static int do_sigpending(void *set, unsigned long sigsetsize)
+{
 	if (sigsetsize > sizeof(sigset_t))
-		goto out;
+		return -EINVAL;
 
 	spin_lock_irq(&current->sighand->siglock);
-	sigorsets(&pending, &current->pending.signal,
+	sigorsets(set, &current->pending.signal,
 		  &current->signal->shared_pending.signal);
 	spin_unlock_irq(&current->sighand->siglock);
 
 	/* Outside the lock because only this thread touches it.  */
-	sigandsets(&pending, &current->blocked, &pending);
-
-	error = -EFAULT;
-	if (!copy_to_user(set, &pending, sigsetsize))
-		error = 0;
-
-out:
-	return error;
+	sigandsets(set, &current->blocked, set);
+	return 0;
 }
 
 /**
  *  sys_rt_sigpending - examine a pending signal that has been raised
  *			while blocked
- *  @set: stores pending signals
+ *  @uset: stores pending signals
  *  @sigsetsize: size of sigset_t type or larger
  */
-SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, set, size_t, sigsetsize)
+SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, uset, size_t, sigsetsize)
 {
-	return do_sigpending(set, sigsetsize);
+	sigset_t set;
+	int err = do_sigpending(&set, sigsetsize);
+	if (!err && copy_to_user(uset, &set, sigsetsize))
+		err = -EFAULT;
+	return err;
+}
+
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE2(rt_sigpending, compat_sigset_t __user *, uset,
+		compat_size_t, sigsetsize)
+{
+#ifdef __BIG_ENDIAN
+	sigset_t set;
+	int err = do_sigpending(&set, sigsetsize);
+	if (!err) {
+		compat_sigset_t set32;
+		sigset_to_compat(&set32, &set);
+		/* we can get here only if sigsetsize <= sizeof(set) */
+		if (copy_to_user(uset, &set32, sigsetsize))
+			err = -EFAULT;
+	}
+	return err;
+#else
+	return sys_rt_sigpending((sigset_t __user *)uset, sigsetsize);
+#endif
 }
+#endif
 
 #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER
 
@@ -2923,6 +2994,23 @@ SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig)
 	return do_tkill(0, pid, sig);
 }
 
+static int do_rt_sigqueueinfo(pid_t pid, int sig, siginfo_t *info)
+{
+	/* Not even root can pretend to send signals from the kernel.
+	 * Nor can they impersonate a kill()/tgkill(), which adds source info.
+	 */
+	if ((info->si_code >= 0 || info->si_code == SI_TKILL) &&
+	    (task_pid_vnr(current) != pid)) {
+		/* We used to allow any < 0 si_code */
+		WARN_ON_ONCE(info->si_code < 0);
+		return -EPERM;
+	}
+	info->si_signo = sig;
+
+	/* POSIX.1b doesn't mention process groups.  */
+	return kill_proc_info(sig, info, pid);
+}
+
 /**
  *  sys_rt_sigqueueinfo - send signal information to a signal
  *  @pid: the PID of the thread
@@ -2933,25 +3021,26 @@ SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig,
 		siginfo_t __user *, uinfo)
 {
 	siginfo_t info;
-
 	if (copy_from_user(&info, uinfo, sizeof(siginfo_t)))
 		return -EFAULT;
+	return do_rt_sigqueueinfo(pid, sig, &info);
+}
 
-	/* Not even root can pretend to send signals from the kernel.
-	 * Nor can they impersonate a kill()/tgkill(), which adds source info.
-	 */
-	if (info.si_code >= 0 || info.si_code == SI_TKILL) {
-		/* We used to allow any < 0 si_code */
-		WARN_ON_ONCE(info.si_code < 0);
-		return -EPERM;
-	}
-	info.si_signo = sig;
-
-	/* POSIX.1b doesn't mention process groups.  */
-	return kill_proc_info(sig, &info, pid);
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE3(rt_sigqueueinfo,
+			compat_pid_t, pid,
+			int, sig,
+			struct compat_siginfo __user *, uinfo)
+{
+	siginfo_t info;
+	int ret = copy_siginfo_from_user32(&info, uinfo);
+	if (unlikely(ret))
+		return ret;
+	return do_rt_sigqueueinfo(pid, sig, &info);
 }
+#endif
 
-long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info)
+static int do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info)
 {
 	/* This is only valid for single tasks */
 	if (pid <= 0 || tgid <= 0)
@@ -2960,7 +3049,8 @@ long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info)
 	/* Not even root can pretend to send signals from the kernel.
 	 * Nor can they impersonate a kill()/tgkill(), which adds source info.
 	 */
-	if (info->si_code >= 0 || info->si_code == SI_TKILL) {
+	if (((info->si_code >= 0 || info->si_code == SI_TKILL)) &&
+	    (task_pid_vnr(current) != pid)) {
 		/* We used to allow any < 0 si_code */
 		WARN_ON_ONCE(info->si_code < 0);
 		return -EPERM;
@@ -2981,6 +3071,21 @@ SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig,
 	return do_rt_tgsigqueueinfo(tgid, pid, sig, &info);
 }
 
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(rt_tgsigqueueinfo,
+			compat_pid_t, tgid,
+			compat_pid_t, pid,
+			int, sig,
+			struct compat_siginfo __user *, uinfo)
+{
+	siginfo_t info;
+
+	if (copy_siginfo_from_user32(&info, uinfo))
+		return -EFAULT;
+	return do_rt_tgsigqueueinfo(tgid, pid, sig, &info);
+}
+#endif
+
 int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
 {
 	struct task_struct *t = current;
@@ -3026,7 +3131,7 @@ int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact)
 	return 0;
 }
 
-int 
+static int 
 do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp)
 {
 	stack_t oss;
@@ -3091,12 +3196,10 @@ do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long s
 out:
 	return error;
 }
-#ifdef CONFIG_GENERIC_SIGALTSTACK
 SYSCALL_DEFINE2(sigaltstack,const stack_t __user *,uss, stack_t __user *,uoss)
 {
 	return do_sigaltstack(uss, uoss, current_user_stack_pointer());
 }
-#endif
 
 int restore_altstack(const stack_t __user *uss)
 {
@@ -3114,7 +3217,6 @@ int __save_altstack(stack_t __user *uss, unsigned long sp)
 }
 
 #ifdef CONFIG_COMPAT
-#ifdef CONFIG_GENERIC_SIGALTSTACK
 COMPAT_SYSCALL_DEFINE2(sigaltstack,
 			const compat_stack_t __user *, uss_ptr,
 			compat_stack_t __user *, uoss_ptr)
@@ -3164,7 +3266,6 @@ int __compat_save_altstack(compat_stack_t __user *uss, unsigned long sp)
 		__put_user(t->sas_ss_size, &uss->ss_size);
 }
 #endif
-#endif
 
 #ifdef __ARCH_WANT_SYS_SIGPENDING
 
@@ -3174,7 +3275,7 @@ int __compat_save_altstack(compat_stack_t __user *uss, unsigned long sp)
  */
 SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set)
 {
-	return do_sigpending(set, sizeof(*set));
+	return sys_rt_sigpending((sigset_t __user *)set, sizeof(old_sigset_t)); 
 }
 
 #endif
@@ -3230,7 +3331,7 @@ SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset,
 }
 #endif /* __ARCH_WANT_SYS_SIGPROCMASK */
 
-#ifdef __ARCH_WANT_SYS_RT_SIGACTION
+#ifndef CONFIG_ODD_RT_SIGACTION
 /**
  *  sys_rt_sigaction - alter an action taken by a process
  *  @sig: signal to be sent
@@ -3264,7 +3365,132 @@ SYSCALL_DEFINE4(rt_sigaction, int, sig,
 out:
 	return ret;
 }
-#endif /* __ARCH_WANT_SYS_RT_SIGACTION */
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE4(rt_sigaction, int, sig,
+		const struct compat_sigaction __user *, act,
+		struct compat_sigaction __user *, oact,
+		compat_size_t, sigsetsize)
+{
+	struct k_sigaction new_ka, old_ka;
+	compat_sigset_t mask;
+#ifdef __ARCH_HAS_SA_RESTORER
+	compat_uptr_t restorer;
+#endif
+	int ret;
+
+	/* XXX: Don't preclude handling different sized sigset_t's.  */
+	if (sigsetsize != sizeof(compat_sigset_t))
+		return -EINVAL;
+
+	if (act) {
+		compat_uptr_t handler;
+		ret = get_user(handler, &act->sa_handler);
+		new_ka.sa.sa_handler = compat_ptr(handler);
+#ifdef __ARCH_HAS_SA_RESTORER
+		ret |= get_user(restorer, &act->sa_restorer);
+		new_ka.sa.sa_restorer = compat_ptr(restorer);
+#endif
+		ret |= copy_from_user(&mask, &act->sa_mask, sizeof(mask));
+		ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
+		if (ret)
+			return -EFAULT;
+		sigset_from_compat(&new_ka.sa.sa_mask, &mask);
+	}
+
+	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
+	if (!ret && oact) {
+		sigset_to_compat(&mask, &old_ka.sa.sa_mask);
+		ret = put_user(ptr_to_compat(old_ka.sa.sa_handler), 
+			       &oact->sa_handler);
+		ret |= copy_to_user(&oact->sa_mask, &mask, sizeof(mask));
+		ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
+#ifdef __ARCH_HAS_SA_RESTORER
+		ret |= put_user(ptr_to_compat(old_ka.sa.sa_restorer),
+				&oact->sa_restorer);
+#endif
+	}
+	return ret;
+}
+#endif
+#endif /* !CONFIG_ODD_RT_SIGACTION */
+
+#ifdef CONFIG_OLD_SIGACTION
+SYSCALL_DEFINE3(sigaction, int, sig,
+		const struct old_sigaction __user *, act,
+	        struct old_sigaction __user *, oact)
+{
+	struct k_sigaction new_ka, old_ka;
+	int ret;
+
+	if (act) {
+		old_sigset_t mask;
+		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
+		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
+		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
+		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+		    __get_user(mask, &act->sa_mask))
+			return -EFAULT;
+#ifdef __ARCH_HAS_KA_RESTORER
+		new_ka.ka_restorer = NULL;
+#endif
+		siginitset(&new_ka.sa.sa_mask, mask);
+	}
+
+	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
+
+	if (!ret && oact) {
+		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
+		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
+		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
+		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
+			return -EFAULT;
+	}
+
+	return ret;
+}
+#endif
+#ifdef CONFIG_COMPAT_OLD_SIGACTION
+COMPAT_SYSCALL_DEFINE3(sigaction, int, sig,
+		const struct compat_old_sigaction __user *, act,
+	        struct compat_old_sigaction __user *, oact)
+{
+	struct k_sigaction new_ka, old_ka;
+	int ret;
+	compat_old_sigset_t mask;
+	compat_uptr_t handler, restorer;
+
+	if (act) {
+		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
+		    __get_user(handler, &act->sa_handler) ||
+		    __get_user(restorer, &act->sa_restorer) ||
+		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+		    __get_user(mask, &act->sa_mask))
+			return -EFAULT;
+
+#ifdef __ARCH_HAS_KA_RESTORER
+		new_ka.ka_restorer = NULL;
+#endif
+		new_ka.sa.sa_handler = compat_ptr(handler);
+		new_ka.sa.sa_restorer = compat_ptr(restorer);
+		siginitset(&new_ka.sa.sa_mask, mask);
+	}
+
+	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
+
+	if (!ret && oact) {
+		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
+		    __put_user(ptr_to_compat(old_ka.sa.sa_handler),
+			       &oact->sa_handler) ||
+		    __put_user(ptr_to_compat(old_ka.sa.sa_restorer),
+			       &oact->sa_restorer) ||
+		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
+			return -EFAULT;
+	}
+	return ret;
+}
+#endif
 
 #ifdef __ARCH_WANT_SYS_SGETMASK
 
@@ -3332,7 +3558,6 @@ int sigsuspend(sigset_t *set)
 	return -ERESTARTNOHAND;
 }
 
-#ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND
 /**
  *  sys_rt_sigsuspend - replace the signal mask for a value with the
  *	@unewset value until a signal is received
@@ -3351,7 +3576,45 @@ SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize)
 		return -EFAULT;
 	return sigsuspend(&newset);
 }
-#endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */
+ 
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE2(rt_sigsuspend, compat_sigset_t __user *, unewset, compat_size_t, sigsetsize)
+{
+#ifdef __BIG_ENDIAN
+	sigset_t newset;
+	compat_sigset_t newset32;
+
+	/* XXX: Don't preclude handling different sized sigset_t's.  */
+	if (sigsetsize != sizeof(sigset_t))
+		return -EINVAL;
+
+	if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t)))
+		return -EFAULT;
+	sigset_from_compat(&newset, &newset32);
+	return sigsuspend(&newset);
+#else
+	/* on little-endian bitmaps don't care about granularity */
+	return sys_rt_sigsuspend((sigset_t __user *)unewset, sigsetsize);
+#endif
+}
+#endif
+
+#ifdef CONFIG_OLD_SIGSUSPEND
+SYSCALL_DEFINE1(sigsuspend, old_sigset_t, mask)
+{
+	sigset_t blocked;
+	siginitset(&blocked, mask);
+	return sigsuspend(&blocked);
+}
+#endif
+#ifdef CONFIG_OLD_SIGSUSPEND3
+SYSCALL_DEFINE3(sigsuspend, int, unused1, int, unused2, old_sigset_t, mask)
+{
+	sigset_t blocked;
+	siginitset(&blocked, mask);
+	return sigsuspend(&blocked);
+}
+#endif
 
 __attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma)
 {
diff --git a/kernel/smp.c b/kernel/smp.c
index 69f38bd98b42..8e451f3ff51b 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -16,22 +16,12 @@
 #include "smpboot.h"
 
 #ifdef CONFIG_USE_GENERIC_SMP_HELPERS
-static struct {
-	struct list_head	queue;
-	raw_spinlock_t		lock;
-} call_function __cacheline_aligned_in_smp =
-	{
-		.queue		= LIST_HEAD_INIT(call_function.queue),
-		.lock		= __RAW_SPIN_LOCK_UNLOCKED(call_function.lock),
-	};
-
 enum {
 	CSD_FLAG_LOCK		= 0x01,
 };
 
 struct call_function_data {
-	struct call_single_data	csd;
-	atomic_t		refs;
+	struct call_single_data	__percpu *csd;
 	cpumask_var_t		cpumask;
 	cpumask_var_t		cpumask_ipi;
 };
@@ -60,6 +50,11 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
 		if (!zalloc_cpumask_var_node(&cfd->cpumask_ipi, GFP_KERNEL,
 				cpu_to_node(cpu)))
 			return notifier_from_errno(-ENOMEM);
+		cfd->csd = alloc_percpu(struct call_single_data);
+		if (!cfd->csd) {
+			free_cpumask_var(cfd->cpumask);
+			return notifier_from_errno(-ENOMEM);
+		}
 		break;
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -70,6 +65,7 @@ hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
 	case CPU_DEAD_FROZEN:
 		free_cpumask_var(cfd->cpumask);
 		free_cpumask_var(cfd->cpumask_ipi);
+		free_percpu(cfd->csd);
 		break;
 #endif
 	};
@@ -171,85 +167,6 @@ void generic_exec_single(int cpu, struct call_single_data *data, int wait)
 }
 
 /*
- * Invoked by arch to handle an IPI for call function. Must be called with
- * interrupts disabled.
- */
-void generic_smp_call_function_interrupt(void)
-{
-	struct call_function_data *data;
-	int cpu = smp_processor_id();
-
-	/*
-	 * Shouldn't receive this interrupt on a cpu that is not yet online.
-	 */
-	WARN_ON_ONCE(!cpu_online(cpu));
-
-	/*
-	 * Ensure entry is visible on call_function_queue after we have
-	 * entered the IPI. See comment in smp_call_function_many.
-	 * If we don't have this, then we may miss an entry on the list
-	 * and never get another IPI to process it.
-	 */
-	smp_mb();
-
-	/*
-	 * It's ok to use list_for_each_rcu() here even though we may
-	 * delete 'pos', since list_del_rcu() doesn't clear ->next
-	 */
-	list_for_each_entry_rcu(data, &call_function.queue, csd.list) {
-		int refs;
-		smp_call_func_t func;
-
-		/*
-		 * Since we walk the list without any locks, we might
-		 * see an entry that was completed, removed from the
-		 * list and is in the process of being reused.
-		 *
-		 * We must check that the cpu is in the cpumask before
-		 * checking the refs, and both must be set before
-		 * executing the callback on this cpu.
-		 */
-
-		if (!cpumask_test_cpu(cpu, data->cpumask))
-			continue;
-
-		smp_rmb();
-
-		if (atomic_read(&data->refs) == 0)
-			continue;
-
-		func = data->csd.func;		/* save for later warn */
-		func(data->csd.info);
-
-		/*
-		 * If the cpu mask is not still set then func enabled
-		 * interrupts (BUG), and this cpu took another smp call
-		 * function interrupt and executed func(info) twice
-		 * on this cpu.  That nested execution decremented refs.
-		 */
-		if (!cpumask_test_and_clear_cpu(cpu, data->cpumask)) {
-			WARN(1, "%pf enabled interrupts and double executed\n", func);
-			continue;
-		}
-
-		refs = atomic_dec_return(&data->refs);
-		WARN_ON(refs < 0);
-
-		if (refs)
-			continue;
-
-		WARN_ON(!cpumask_empty(data->cpumask));
-
-		raw_spin_lock(&call_function.lock);
-		list_del_rcu(&data->csd.list);
-		raw_spin_unlock(&call_function.lock);
-
-		csd_unlock(&data->csd);
-	}
-
-}
-
-/*
  * Invoked by arch to handle an IPI for call function single. Must be
  * called from the arch with interrupts disabled.
  */
@@ -453,8 +370,7 @@ void smp_call_function_many(const struct cpumask *mask,
 			    smp_call_func_t func, void *info, bool wait)
 {
 	struct call_function_data *data;
-	unsigned long flags;
-	int refs, cpu, next_cpu, this_cpu = smp_processor_id();
+	int cpu, next_cpu, this_cpu = smp_processor_id();
 
 	/*
 	 * Can deadlock when called with interrupts disabled.
@@ -486,50 +402,13 @@ void smp_call_function_many(const struct cpumask *mask,
 	}
 
 	data = &__get_cpu_var(cfd_data);
-	csd_lock(&data->csd);
-
-	/* This BUG_ON verifies our reuse assertions and can be removed */
-	BUG_ON(atomic_read(&data->refs) || !cpumask_empty(data->cpumask));
-
-	/*
-	 * The global call function queue list add and delete are protected
-	 * by a lock, but the list is traversed without any lock, relying
-	 * on the rcu list add and delete to allow safe concurrent traversal.
-	 * We reuse the call function data without waiting for any grace
-	 * period after some other cpu removes it from the global queue.
-	 * This means a cpu might find our data block as it is being
-	 * filled out.
-	 *
-	 * We hold off the interrupt handler on the other cpu by
-	 * ordering our writes to the cpu mask vs our setting of the
-	 * refs counter.  We assert only the cpu owning the data block
-	 * will set a bit in cpumask, and each bit will only be cleared
-	 * by the subject cpu.  Each cpu must first find its bit is
-	 * set and then check that refs is set indicating the element is
-	 * ready to be processed, otherwise it must skip the entry.
-	 *
-	 * On the previous iteration refs was set to 0 by another cpu.
-	 * To avoid the use of transitivity, set the counter to 0 here
-	 * so the wmb will pair with the rmb in the interrupt handler.
-	 */
-	atomic_set(&data->refs, 0);	/* convert 3rd to 1st party write */
-
-	data->csd.func = func;
-	data->csd.info = info;
 
-	/* Ensure 0 refs is visible before mask.  Also orders func and info */
-	smp_wmb();
-
-	/* We rely on the "and" being processed before the store */
 	cpumask_and(data->cpumask, mask, cpu_online_mask);
 	cpumask_clear_cpu(this_cpu, data->cpumask);
-	refs = cpumask_weight(data->cpumask);
 
 	/* Some callers race with other cpus changing the passed mask */
-	if (unlikely(!refs)) {
-		csd_unlock(&data->csd);
+	if (unlikely(!cpumask_weight(data->cpumask)))
 		return;
-	}
 
 	/*
 	 * After we put an entry into the list, data->cpumask
@@ -537,34 +416,32 @@ void smp_call_function_many(const struct cpumask *mask,
 	 * a SMP function call, so data->cpumask will be zero.
 	 */
 	cpumask_copy(data->cpumask_ipi, data->cpumask);
-	raw_spin_lock_irqsave(&call_function.lock, flags);
-	/*
-	 * Place entry at the _HEAD_ of the list, so that any cpu still
-	 * observing the entry in generic_smp_call_function_interrupt()
-	 * will not miss any other list entries:
-	 */
-	list_add_rcu(&data->csd.list, &call_function.queue);
-	/*
-	 * We rely on the wmb() in list_add_rcu to complete our writes
-	 * to the cpumask before this write to refs, which indicates
-	 * data is on the list and is ready to be processed.
-	 */
-	atomic_set(&data->refs, refs);
-	raw_spin_unlock_irqrestore(&call_function.lock, flags);
 
-	/*
-	 * Make the list addition visible before sending the ipi.
-	 * (IPIs must obey or appear to obey normal Linux cache
-	 * coherency rules -- see comment in generic_exec_single).
-	 */
-	smp_mb();
+	for_each_cpu(cpu, data->cpumask) {
+		struct call_single_data *csd = per_cpu_ptr(data->csd, cpu);
+		struct call_single_queue *dst =
+					&per_cpu(call_single_queue, cpu);
+		unsigned long flags;
+
+		csd_lock(csd);
+		csd->func = func;
+		csd->info = info;
+
+		raw_spin_lock_irqsave(&dst->lock, flags);
+		list_add_tail(&csd->list, &dst->list);
+		raw_spin_unlock_irqrestore(&dst->lock, flags);
+	}
 
 	/* Send a message to all CPUs in the map */
 	arch_send_call_function_ipi_mask(data->cpumask_ipi);
 
-	/* Optionally wait for the CPUs to complete */
-	if (wait)
-		csd_lock_wait(&data->csd);
+	if (wait) {
+		for_each_cpu(cpu, data->cpumask) {
+			struct call_single_data *csd =
+					per_cpu_ptr(data->csd, cpu);
+			csd_lock_wait(csd);
+		}
+	}
 }
 EXPORT_SYMBOL(smp_call_function_many);
 
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index d6c5fc054242..8eaed9aa9cf0 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -183,9 +183,10 @@ __smpboot_create_thread(struct smp_hotplug_thread *ht, unsigned int cpu)
 		kfree(td);
 		return PTR_ERR(tsk);
 	}
-
 	get_task_struct(tsk);
 	*per_cpu_ptr(ht->store, cpu) = tsk;
+	if (ht->create)
+		ht->create(cpu);
 	return 0;
 }
 
@@ -208,6 +209,8 @@ static void smpboot_unpark_thread(struct smp_hotplug_thread *ht, unsigned int cp
 {
 	struct task_struct *tsk = *per_cpu_ptr(ht->store, cpu);
 
+	if (ht->pre_unpark)
+		ht->pre_unpark(cpu);
 	kthread_unpark(tsk);
 }
 
@@ -225,7 +228,7 @@ static void smpboot_park_thread(struct smp_hotplug_thread *ht, unsigned int cpu)
 {
 	struct task_struct *tsk = *per_cpu_ptr(ht->store, cpu);
 
-	if (tsk)
+	if (tsk && !ht->selfparking)
 		kthread_park(tsk);
 }
 
diff --git a/kernel/softirq.c b/kernel/softirq.c
index ed567babe789..14d7758074aa 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -195,21 +195,21 @@ void local_bh_enable_ip(unsigned long ip)
 EXPORT_SYMBOL(local_bh_enable_ip);
 
 /*
- * We restart softirq processing MAX_SOFTIRQ_RESTART times,
- * and we fall back to softirqd after that.
+ * We restart softirq processing for at most 2 ms,
+ * and if need_resched() is not set.
  *
- * This number has been established via experimentation.
+ * These limits have been established via experimentation.
  * The two things to balance is latency against fairness -
  * we want to handle softirqs as soon as possible, but they
  * should not be able to lock up the box.
  */
-#define MAX_SOFTIRQ_RESTART 10
+#define MAX_SOFTIRQ_TIME  msecs_to_jiffies(2)
 
 asmlinkage void __do_softirq(void)
 {
 	struct softirq_action *h;
 	__u32 pending;
-	int max_restart = MAX_SOFTIRQ_RESTART;
+	unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
 	int cpu;
 	unsigned long old_flags = current->flags;
 
@@ -221,7 +221,7 @@ asmlinkage void __do_softirq(void)
 	current->flags &= ~PF_MEMALLOC;
 
 	pending = local_softirq_pending();
-	vtime_account_irq_enter(current);
+	account_irq_enter_time(current);
 
 	__local_bh_disable((unsigned long)__builtin_return_address(0),
 				SOFTIRQ_OFFSET);
@@ -264,15 +264,16 @@ restart:
 	local_irq_disable();
 
 	pending = local_softirq_pending();
-	if (pending && --max_restart)
-		goto restart;
+	if (pending) {
+		if (time_before(jiffies, end) && !need_resched())
+			goto restart;
 
-	if (pending)
 		wakeup_softirqd();
+	}
 
 	lockdep_softirq_exit();
 
-	vtime_account_irq_exit(current);
+	account_irq_exit_time(current);
 	__local_bh_enable(SOFTIRQ_OFFSET);
 	tsk_restore_flags(current, old_flags, PF_MEMALLOC);
 }
@@ -322,18 +323,10 @@ void irq_enter(void)
 
 static inline void invoke_softirq(void)
 {
-	if (!force_irqthreads) {
-#ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED
+	if (!force_irqthreads)
 		__do_softirq();
-#else
-		do_softirq();
-#endif
-	} else {
-		__local_bh_disable((unsigned long)__builtin_return_address(0),
-				SOFTIRQ_OFFSET);
+	else
 		wakeup_softirqd();
-		__local_bh_enable(SOFTIRQ_OFFSET);
-	}
 }
 
 /*
@@ -341,9 +334,15 @@ static inline void invoke_softirq(void)
  */
 void irq_exit(void)
 {
-	vtime_account_irq_exit(current);
+#ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED
+	local_irq_disable();
+#else
+	WARN_ON_ONCE(!irqs_disabled());
+#endif
+
+	account_irq_exit_time(current);
 	trace_hardirq_exit();
-	sub_preempt_count(IRQ_EXIT_OFFSET);
+	sub_preempt_count(HARDIRQ_OFFSET);
 	if (!in_interrupt() && local_softirq_pending())
 		invoke_softirq();
 
@@ -353,7 +352,6 @@ void irq_exit(void)
 		tick_nohz_irq_exit();
 #endif
 	rcu_irq_exit();
-	sched_preempt_enable_no_resched();
 }
 
 /*
diff --git a/kernel/srcu.c b/kernel/srcu.c
index 2b859828cdc3..01d5ccb8bfe3 100644
--- a/kernel/srcu.c
+++ b/kernel/srcu.c
@@ -282,12 +282,8 @@ static int srcu_readers_active(struct srcu_struct *sp)
  */
 void cleanup_srcu_struct(struct srcu_struct *sp)
 {
-	int sum;
-
-	sum = srcu_readers_active(sp);
-	WARN_ON(sum);  /* Leakage unless caller handles error. */
-	if (sum != 0)
-		return;
+	if (WARN_ON(srcu_readers_active(sp)))
+		return; /* Leakage unless caller handles error. */
 	free_percpu(sp->per_cpu_ref);
 	sp->per_cpu_ref = NULL;
 }
@@ -302,9 +298,8 @@ int __srcu_read_lock(struct srcu_struct *sp)
 {
 	int idx;
 
+	idx = ACCESS_ONCE(sp->completed) & 0x1;
 	preempt_disable();
-	idx = rcu_dereference_index_check(sp->completed,
-					  rcu_read_lock_sched_held()) & 0x1;
 	ACCESS_ONCE(this_cpu_ptr(sp->per_cpu_ref)->c[idx]) += 1;
 	smp_mb(); /* B */  /* Avoid leaking the critical section. */
 	ACCESS_ONCE(this_cpu_ptr(sp->per_cpu_ref)->seq[idx]) += 1;
@@ -321,10 +316,8 @@ EXPORT_SYMBOL_GPL(__srcu_read_lock);
  */
 void __srcu_read_unlock(struct srcu_struct *sp, int idx)
 {
-	preempt_disable();
 	smp_mb(); /* C */  /* Avoid leaking the critical section. */
-	ACCESS_ONCE(this_cpu_ptr(sp->per_cpu_ref)->c[idx]) -= 1;
-	preempt_enable();
+	this_cpu_dec(sp->per_cpu_ref->c[idx]);
 }
 EXPORT_SYMBOL_GPL(__srcu_read_unlock);
 
@@ -423,6 +416,7 @@ static void __synchronize_srcu(struct srcu_struct *sp, int trycount)
 			   !lock_is_held(&rcu_sched_lock_map),
 			   "Illegal synchronize_srcu() in same-type SRCU (or RCU) read-side critical section");
 
+	might_sleep();
 	init_completion(&rcu.completion);
 
 	head->next = NULL;
@@ -455,10 +449,12 @@ static void __synchronize_srcu(struct srcu_struct *sp, int trycount)
  * synchronize_srcu - wait for prior SRCU read-side critical-section completion
  * @sp: srcu_struct with which to synchronize.
  *
- * Flip the completed counter, and wait for the old count to drain to zero.
- * As with classic RCU, the updater must use some separate means of
- * synchronizing concurrent updates.  Can block; must be called from
- * process context.
+ * Wait for the count to drain to zero of both indexes. To avoid the
+ * possible starvation of synchronize_srcu(), it waits for the count of
+ * the index=((->completed & 1) ^ 1) to drain to zero at first,
+ * and then flip the completed and wait for the count of the other index.
+ *
+ * Can block; must be called from process context.
  *
  * Note that it is illegal to call synchronize_srcu() from the corresponding
  * SRCU read-side critical section; doing so will result in deadlock.
@@ -480,12 +476,11 @@ EXPORT_SYMBOL_GPL(synchronize_srcu);
  * Wait for an SRCU grace period to elapse, but be more aggressive about
  * spinning rather than blocking when waiting.
  *
- * Note that it is illegal to call this function while holding any lock
- * that is acquired by a CPU-hotplug notifier.  It is also illegal to call
- * synchronize_srcu_expedited() from the corresponding SRCU read-side
- * critical section; doing so will result in deadlock.  However, it is
- * perfectly legal to call synchronize_srcu_expedited() on one srcu_struct
- * from some other srcu_struct's read-side critical section, as long as
+ * Note that it is also illegal to call synchronize_srcu_expedited()
+ * from the corresponding SRCU read-side critical section;
+ * doing so will result in deadlock.  However, it is perfectly legal
+ * to call synchronize_srcu_expedited() on one srcu_struct from some
+ * other srcu_struct's read-side critical section, as long as
  * the resulting graph of srcu_structs is acyclic.
  */
 void synchronize_srcu_expedited(struct srcu_struct *sp)
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 2f194e965715..c09f2955ae30 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -18,7 +18,7 @@
 #include <linux/stop_machine.h>
 #include <linux/interrupt.h>
 #include <linux/kallsyms.h>
-
+#include <linux/smpboot.h>
 #include <linux/atomic.h>
 
 /*
@@ -37,10 +37,10 @@ struct cpu_stopper {
 	spinlock_t		lock;
 	bool			enabled;	/* is this stopper enabled? */
 	struct list_head	works;		/* list of pending works */
-	struct task_struct	*thread;	/* stopper thread */
 };
 
 static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);
+static DEFINE_PER_CPU(struct task_struct *, cpu_stopper_task);
 static bool stop_machine_initialized = false;
 
 static void cpu_stop_init_done(struct cpu_stop_done *done, unsigned int nr_todo)
@@ -62,16 +62,18 @@ static void cpu_stop_signal_done(struct cpu_stop_done *done, bool executed)
 }
 
 /* queue @work to @stopper.  if offline, @work is completed immediately */
-static void cpu_stop_queue_work(struct cpu_stopper *stopper,
-				struct cpu_stop_work *work)
+static void cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work)
 {
+	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
+	struct task_struct *p = per_cpu(cpu_stopper_task, cpu);
+
 	unsigned long flags;
 
 	spin_lock_irqsave(&stopper->lock, flags);
 
 	if (stopper->enabled) {
 		list_add_tail(&work->list, &stopper->works);
-		wake_up_process(stopper->thread);
+		wake_up_process(p);
 	} else
 		cpu_stop_signal_done(work->done, false);
 
@@ -108,7 +110,7 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
 	struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done };
 
 	cpu_stop_init_done(&done, 1);
-	cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), &work);
+	cpu_stop_queue_work(cpu, &work);
 	wait_for_completion(&done.completion);
 	return done.executed ? done.ret : -ENOENT;
 }
@@ -130,7 +132,7 @@ void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg,
 			struct cpu_stop_work *work_buf)
 {
 	*work_buf = (struct cpu_stop_work){ .fn = fn, .arg = arg, };
-	cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), work_buf);
+	cpu_stop_queue_work(cpu, work_buf);
 }
 
 /* static data for stop_cpus */
@@ -159,8 +161,7 @@ static void queue_stop_cpus_work(const struct cpumask *cpumask,
 	 */
 	preempt_disable();
 	for_each_cpu(cpu, cpumask)
-		cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu),
-				    &per_cpu(stop_cpus_work, cpu));
+		cpu_stop_queue_work(cpu, &per_cpu(stop_cpus_work, cpu));
 	preempt_enable();
 }
 
@@ -244,20 +245,25 @@ int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg)
 	return ret;
 }
 
-static int cpu_stopper_thread(void *data)
+static int cpu_stop_should_run(unsigned int cpu)
+{
+	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
+	unsigned long flags;
+	int run;
+
+	spin_lock_irqsave(&stopper->lock, flags);
+	run = !list_empty(&stopper->works);
+	spin_unlock_irqrestore(&stopper->lock, flags);
+	return run;
+}
+
+static void cpu_stopper_thread(unsigned int cpu)
 {
-	struct cpu_stopper *stopper = data;
+	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
 	struct cpu_stop_work *work;
 	int ret;
 
 repeat:
-	set_current_state(TASK_INTERRUPTIBLE);	/* mb paired w/ kthread_stop */
-
-	if (kthread_should_stop()) {
-		__set_current_state(TASK_RUNNING);
-		return 0;
-	}
-
 	work = NULL;
 	spin_lock_irq(&stopper->lock);
 	if (!list_empty(&stopper->works)) {
@@ -273,8 +279,6 @@ repeat:
 		struct cpu_stop_done *done = work->done;
 		char ksym_buf[KSYM_NAME_LEN] __maybe_unused;
 
-		__set_current_state(TASK_RUNNING);
-
 		/* cpu stop callbacks are not allowed to sleep */
 		preempt_disable();
 
@@ -290,88 +294,55 @@ repeat:
 					  ksym_buf), arg);
 
 		cpu_stop_signal_done(done, true);
-	} else
-		schedule();
-
-	goto repeat;
+		goto repeat;
+	}
 }
 
 extern void sched_set_stop_task(int cpu, struct task_struct *stop);
 
-/* manage stopper for a cpu, mostly lifted from sched migration thread mgmt */
-static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb,
-					   unsigned long action, void *hcpu)
+static void cpu_stop_create(unsigned int cpu)
+{
+	sched_set_stop_task(cpu, per_cpu(cpu_stopper_task, cpu));
+}
+
+static void cpu_stop_park(unsigned int cpu)
 {
-	unsigned int cpu = (unsigned long)hcpu;
 	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
-	struct task_struct *p;
-
-	switch (action & ~CPU_TASKS_FROZEN) {
-	case CPU_UP_PREPARE:
-		BUG_ON(stopper->thread || stopper->enabled ||
-		       !list_empty(&stopper->works));
-		p = kthread_create_on_node(cpu_stopper_thread,
-					   stopper,
-					   cpu_to_node(cpu),
-					   "migration/%d", cpu);
-		if (IS_ERR(p))
-			return notifier_from_errno(PTR_ERR(p));
-		get_task_struct(p);
-		kthread_bind(p, cpu);
-		sched_set_stop_task(cpu, p);
-		stopper->thread = p;
-		break;
-
-	case CPU_ONLINE:
-		/* strictly unnecessary, as first user will wake it */
-		wake_up_process(stopper->thread);
-		/* mark enabled */
-		spin_lock_irq(&stopper->lock);
-		stopper->enabled = true;
-		spin_unlock_irq(&stopper->lock);
-		break;
-
-#ifdef CONFIG_HOTPLUG_CPU
-	case CPU_UP_CANCELED:
-	case CPU_POST_DEAD:
-	{
-		struct cpu_stop_work *work;
-
-		sched_set_stop_task(cpu, NULL);
-		/* kill the stopper */
-		kthread_stop(stopper->thread);
-		/* drain remaining works */
-		spin_lock_irq(&stopper->lock);
-		list_for_each_entry(work, &stopper->works, list)
-			cpu_stop_signal_done(work->done, false);
-		stopper->enabled = false;
-		spin_unlock_irq(&stopper->lock);
-		/* release the stopper */
-		put_task_struct(stopper->thread);
-		stopper->thread = NULL;
-		break;
-	}
-#endif
-	}
+	struct cpu_stop_work *work;
+	unsigned long flags;
 
-	return NOTIFY_OK;
+	/* drain remaining works */
+	spin_lock_irqsave(&stopper->lock, flags);
+	list_for_each_entry(work, &stopper->works, list)
+		cpu_stop_signal_done(work->done, false);
+	stopper->enabled = false;
+	spin_unlock_irqrestore(&stopper->lock, flags);
 }
 
-/*
- * Give it a higher priority so that cpu stopper is available to other
- * cpu notifiers.  It currently shares the same priority as sched
- * migration_notifier.
- */
-static struct notifier_block __cpuinitdata cpu_stop_cpu_notifier = {
-	.notifier_call	= cpu_stop_cpu_callback,
-	.priority	= 10,
+static void cpu_stop_unpark(unsigned int cpu)
+{
+	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
+
+	spin_lock_irq(&stopper->lock);
+	stopper->enabled = true;
+	spin_unlock_irq(&stopper->lock);
+}
+
+static struct smp_hotplug_thread cpu_stop_threads = {
+	.store			= &cpu_stopper_task,
+	.thread_should_run	= cpu_stop_should_run,
+	.thread_fn		= cpu_stopper_thread,
+	.thread_comm		= "migration/%u",
+	.create			= cpu_stop_create,
+	.setup			= cpu_stop_unpark,
+	.park			= cpu_stop_park,
+	.pre_unpark		= cpu_stop_unpark,
+	.selfparking		= true,
 };
 
 static int __init cpu_stop_init(void)
 {
-	void *bcpu = (void *)(long)smp_processor_id();
 	unsigned int cpu;
-	int err;
 
 	for_each_possible_cpu(cpu) {
 		struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
@@ -380,15 +351,8 @@ static int __init cpu_stop_init(void)
 		INIT_LIST_HEAD(&stopper->works);
 	}
 
-	/* start one for the boot cpu */
-	err = cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_UP_PREPARE,
-				    bcpu);
-	BUG_ON(err != NOTIFY_OK);
-	cpu_stop_cpu_callback(&cpu_stop_cpu_notifier, CPU_ONLINE, bcpu);
-	register_cpu_notifier(&cpu_stop_cpu_notifier);
-
+	BUG_ON(smpboot_register_percpu_thread(&cpu_stop_threads));
 	stop_machine_initialized = true;
-
 	return 0;
 }
 early_initcall(cpu_stop_init);
diff --git a/kernel/sys.c b/kernel/sys.c
index 265b37690421..81f56445fba9 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -47,6 +47,7 @@
 #include <linux/syscalls.h>
 #include <linux/kprobes.h>
 #include <linux/user_namespace.h>
+#include <linux/binfmts.h>
 
 #include <linux/kmsg_dump.h>
 /* Move somewhere else to avoid recompiling? */
@@ -433,11 +434,12 @@ static DEFINE_MUTEX(reboot_mutex);
 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 		void __user *, arg)
 {
+	struct pid_namespace *pid_ns = task_active_pid_ns(current);
 	char buffer[256];
 	int ret = 0;
 
 	/* We only trust the superuser with rebooting the system. */
-	if (!capable(CAP_SYS_BOOT))
+	if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT))
 		return -EPERM;
 
 	/* For safety, we require "magic" arguments. */
@@ -453,7 +455,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 	 * pid_namespace, the command is handled by reboot_pid_ns() which will
 	 * call do_exit().
 	 */
-	ret = reboot_pid_ns(task_active_pid_ns(current), cmd);
+	ret = reboot_pid_ns(pid_ns, cmd);
 	if (ret)
 		return ret;
 
@@ -1792,14 +1794,14 @@ SYSCALL_DEFINE1(umask, int, mask)
 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
 {
 	struct fd exe;
-	struct dentry *dentry;
+	struct inode *inode;
 	int err;
 
 	exe = fdget(fd);
 	if (!exe.file)
 		return -EBADF;
 
-	dentry = exe.file->f_path.dentry;
+	inode = file_inode(exe.file);
 
 	/*
 	 * Because the original mm->exe_file points to executable file, make
@@ -1807,11 +1809,11 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
 	 * overall picture.
 	 */
 	err = -EACCES;
-	if (!S_ISREG(dentry->d_inode->i_mode)	||
+	if (!S_ISREG(inode->i_mode)	||
 	    exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC)
 		goto exit;
 
-	err = inode_permission(dentry->d_inode, MAY_EXEC);
+	err = inode_permission(inode, MAY_EXEC);
 	if (err)
 		goto exit;
 
@@ -2012,160 +2014,159 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 
 	error = 0;
 	switch (option) {
-		case PR_SET_PDEATHSIG:
-			if (!valid_signal(arg2)) {
-				error = -EINVAL;
-				break;
-			}
-			me->pdeath_signal = arg2;
-			break;
-		case PR_GET_PDEATHSIG:
-			error = put_user(me->pdeath_signal, (int __user *)arg2);
-			break;
-		case PR_GET_DUMPABLE:
-			error = get_dumpable(me->mm);
+	case PR_SET_PDEATHSIG:
+		if (!valid_signal(arg2)) {
+			error = -EINVAL;
 			break;
-		case PR_SET_DUMPABLE:
-			if (arg2 < 0 || arg2 > 1) {
-				error = -EINVAL;
-				break;
-			}
-			set_dumpable(me->mm, arg2);
+		}
+		me->pdeath_signal = arg2;
+		break;
+	case PR_GET_PDEATHSIG:
+		error = put_user(me->pdeath_signal, (int __user *)arg2);
+		break;
+	case PR_GET_DUMPABLE:
+		error = get_dumpable(me->mm);
+		break;
+	case PR_SET_DUMPABLE:
+		if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
+			error = -EINVAL;
 			break;
+		}
+		set_dumpable(me->mm, arg2);
+		break;
 
-		case PR_SET_UNALIGN:
-			error = SET_UNALIGN_CTL(me, arg2);
-			break;
-		case PR_GET_UNALIGN:
-			error = GET_UNALIGN_CTL(me, arg2);
-			break;
-		case PR_SET_FPEMU:
-			error = SET_FPEMU_CTL(me, arg2);
-			break;
-		case PR_GET_FPEMU:
-			error = GET_FPEMU_CTL(me, arg2);
-			break;
-		case PR_SET_FPEXC:
-			error = SET_FPEXC_CTL(me, arg2);
-			break;
-		case PR_GET_FPEXC:
-			error = GET_FPEXC_CTL(me, arg2);
-			break;
-		case PR_GET_TIMING:
-			error = PR_TIMING_STATISTICAL;
-			break;
-		case PR_SET_TIMING:
-			if (arg2 != PR_TIMING_STATISTICAL)
-				error = -EINVAL;
-			break;
-		case PR_SET_NAME:
-			comm[sizeof(me->comm)-1] = 0;
-			if (strncpy_from_user(comm, (char __user *)arg2,
-					      sizeof(me->comm) - 1) < 0)
-				return -EFAULT;
-			set_task_comm(me, comm);
-			proc_comm_connector(me);
-			break;
-		case PR_GET_NAME:
-			get_task_comm(comm, me);
-			if (copy_to_user((char __user *)arg2, comm,
-					 sizeof(comm)))
-				return -EFAULT;
-			break;
-		case PR_GET_ENDIAN:
-			error = GET_ENDIAN(me, arg2);
-			break;
-		case PR_SET_ENDIAN:
-			error = SET_ENDIAN(me, arg2);
-			break;
-		case PR_GET_SECCOMP:
-			error = prctl_get_seccomp();
-			break;
-		case PR_SET_SECCOMP:
-			error = prctl_set_seccomp(arg2, (char __user *)arg3);
-			break;
-		case PR_GET_TSC:
-			error = GET_TSC_CTL(arg2);
-			break;
-		case PR_SET_TSC:
-			error = SET_TSC_CTL(arg2);
-			break;
-		case PR_TASK_PERF_EVENTS_DISABLE:
-			error = perf_event_task_disable();
-			break;
-		case PR_TASK_PERF_EVENTS_ENABLE:
-			error = perf_event_task_enable();
-			break;
-		case PR_GET_TIMERSLACK:
-			error = current->timer_slack_ns;
-			break;
-		case PR_SET_TIMERSLACK:
-			if (arg2 <= 0)
-				current->timer_slack_ns =
+	case PR_SET_UNALIGN:
+		error = SET_UNALIGN_CTL(me, arg2);
+		break;
+	case PR_GET_UNALIGN:
+		error = GET_UNALIGN_CTL(me, arg2);
+		break;
+	case PR_SET_FPEMU:
+		error = SET_FPEMU_CTL(me, arg2);
+		break;
+	case PR_GET_FPEMU:
+		error = GET_FPEMU_CTL(me, arg2);
+		break;
+	case PR_SET_FPEXC:
+		error = SET_FPEXC_CTL(me, arg2);
+		break;
+	case PR_GET_FPEXC:
+		error = GET_FPEXC_CTL(me, arg2);
+		break;
+	case PR_GET_TIMING:
+		error = PR_TIMING_STATISTICAL;
+		break;
+	case PR_SET_TIMING:
+		if (arg2 != PR_TIMING_STATISTICAL)
+			error = -EINVAL;
+		break;
+	case PR_SET_NAME:
+		comm[sizeof(me->comm) - 1] = 0;
+		if (strncpy_from_user(comm, (char __user *)arg2,
+				      sizeof(me->comm) - 1) < 0)
+			return -EFAULT;
+		set_task_comm(me, comm);
+		proc_comm_connector(me);
+		break;
+	case PR_GET_NAME:
+		get_task_comm(comm, me);
+		if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
+			return -EFAULT;
+		break;
+	case PR_GET_ENDIAN:
+		error = GET_ENDIAN(me, arg2);
+		break;
+	case PR_SET_ENDIAN:
+		error = SET_ENDIAN(me, arg2);
+		break;
+	case PR_GET_SECCOMP:
+		error = prctl_get_seccomp();
+		break;
+	case PR_SET_SECCOMP:
+		error = prctl_set_seccomp(arg2, (char __user *)arg3);
+		break;
+	case PR_GET_TSC:
+		error = GET_TSC_CTL(arg2);
+		break;
+	case PR_SET_TSC:
+		error = SET_TSC_CTL(arg2);
+		break;
+	case PR_TASK_PERF_EVENTS_DISABLE:
+		error = perf_event_task_disable();
+		break;
+	case PR_TASK_PERF_EVENTS_ENABLE:
+		error = perf_event_task_enable();
+		break;
+	case PR_GET_TIMERSLACK:
+		error = current->timer_slack_ns;
+		break;
+	case PR_SET_TIMERSLACK:
+		if (arg2 <= 0)
+			current->timer_slack_ns =
 					current->default_timer_slack_ns;
-			else
-				current->timer_slack_ns = arg2;
-			break;
-		case PR_MCE_KILL:
-			if (arg4 | arg5)
-				return -EINVAL;
-			switch (arg2) {
-			case PR_MCE_KILL_CLEAR:
-				if (arg3 != 0)
-					return -EINVAL;
-				current->flags &= ~PF_MCE_PROCESS;
-				break;
-			case PR_MCE_KILL_SET:
-				current->flags |= PF_MCE_PROCESS;
-				if (arg3 == PR_MCE_KILL_EARLY)
-					current->flags |= PF_MCE_EARLY;
-				else if (arg3 == PR_MCE_KILL_LATE)
-					current->flags &= ~PF_MCE_EARLY;
-				else if (arg3 == PR_MCE_KILL_DEFAULT)
-					current->flags &=
-						~(PF_MCE_EARLY|PF_MCE_PROCESS);
-				else
-					return -EINVAL;
-				break;
-			default:
+		else
+			current->timer_slack_ns = arg2;
+		break;
+	case PR_MCE_KILL:
+		if (arg4 | arg5)
+			return -EINVAL;
+		switch (arg2) {
+		case PR_MCE_KILL_CLEAR:
+			if (arg3 != 0)
 				return -EINVAL;
-			}
+			current->flags &= ~PF_MCE_PROCESS;
 			break;
-		case PR_MCE_KILL_GET:
-			if (arg2 | arg3 | arg4 | arg5)
-				return -EINVAL;
-			if (current->flags & PF_MCE_PROCESS)
-				error = (current->flags & PF_MCE_EARLY) ?
-					PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
+		case PR_MCE_KILL_SET:
+			current->flags |= PF_MCE_PROCESS;
+			if (arg3 == PR_MCE_KILL_EARLY)
+				current->flags |= PF_MCE_EARLY;
+			else if (arg3 == PR_MCE_KILL_LATE)
+				current->flags &= ~PF_MCE_EARLY;
+			else if (arg3 == PR_MCE_KILL_DEFAULT)
+				current->flags &=
+						~(PF_MCE_EARLY|PF_MCE_PROCESS);
 			else
-				error = PR_MCE_KILL_DEFAULT;
-			break;
-		case PR_SET_MM:
-			error = prctl_set_mm(arg2, arg3, arg4, arg5);
-			break;
-		case PR_GET_TID_ADDRESS:
-			error = prctl_get_tid_address(me, (int __user **)arg2);
-			break;
-		case PR_SET_CHILD_SUBREAPER:
-			me->signal->is_child_subreaper = !!arg2;
-			break;
-		case PR_GET_CHILD_SUBREAPER:
-			error = put_user(me->signal->is_child_subreaper,
-					 (int __user *) arg2);
-			break;
-		case PR_SET_NO_NEW_PRIVS:
-			if (arg2 != 1 || arg3 || arg4 || arg5)
 				return -EINVAL;
-
-			current->no_new_privs = 1;
 			break;
-		case PR_GET_NO_NEW_PRIVS:
-			if (arg2 || arg3 || arg4 || arg5)
-				return -EINVAL;
-			return current->no_new_privs ? 1 : 0;
 		default:
-			error = -EINVAL;
-			break;
+			return -EINVAL;
+		}
+		break;
+	case PR_MCE_KILL_GET:
+		if (arg2 | arg3 | arg4 | arg5)
+			return -EINVAL;
+		if (current->flags & PF_MCE_PROCESS)
+			error = (current->flags & PF_MCE_EARLY) ?
+				PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
+		else
+			error = PR_MCE_KILL_DEFAULT;
+		break;
+	case PR_SET_MM:
+		error = prctl_set_mm(arg2, arg3, arg4, arg5);
+		break;
+	case PR_GET_TID_ADDRESS:
+		error = prctl_get_tid_address(me, (int __user **)arg2);
+		break;
+	case PR_SET_CHILD_SUBREAPER:
+		me->signal->is_child_subreaper = !!arg2;
+		break;
+	case PR_GET_CHILD_SUBREAPER:
+		error = put_user(me->signal->is_child_subreaper,
+				 (int __user *)arg2);
+		break;
+	case PR_SET_NO_NEW_PRIVS:
+		if (arg2 != 1 || arg3 || arg4 || arg5)
+			return -EINVAL;
+
+		current->no_new_privs = 1;
+		break;
+	case PR_GET_NO_NEW_PRIVS:
+		if (arg2 || arg3 || arg4 || arg5)
+			return -EINVAL;
+		return current->no_new_privs ? 1 : 0;
+	default:
+		error = -EINVAL;
+		break;
 	}
 	return error;
 }
@@ -2184,11 +2185,6 @@ SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
 
 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
 
-static void argv_cleanup(struct subprocess_info *info)
-{
-	argv_free(info->argv);
-}
-
 static int __orderly_poweroff(void)
 {
 	int argc;
@@ -2208,9 +2204,8 @@ static int __orderly_poweroff(void)
 	}
 
 	ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_WAIT_EXEC,
-				      NULL, argv_cleanup, NULL);
-	if (ret == -ENOMEM)
-		argv_free(argv);
+				      NULL, NULL, NULL);
+	argv_free(argv);
 
 	return ret;
 }
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c88878db491e..afc1dc60f3f8 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -61,6 +61,7 @@
 #include <linux/kmod.h>
 #include <linux/capability.h>
 #include <linux/binfmts.h>
+#include <linux/sched/sysctl.h>
 
 #include <asm/uaccess.h>
 #include <asm/processor.h>
@@ -104,7 +105,6 @@ extern char core_pattern[];
 extern unsigned int core_pipe_limit;
 #endif
 extern int pid_max;
-extern int min_free_kbytes;
 extern int pid_max_min, pid_max_max;
 extern int sysctl_drop_caches;
 extern int percpu_pagelist_fraction;
@@ -157,14 +157,20 @@ extern int sysctl_tsb_ratio;
 
 #ifdef __hppa__
 extern int pwrsw_enabled;
+#endif
+
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
 extern int unaligned_enabled;
 #endif
 
 #ifdef CONFIG_IA64
-extern int no_unaligned_warning;
 extern int unaligned_dump_stack;
 #endif
 
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
+extern int no_unaligned_warning;
+#endif
+
 #ifdef CONFIG_PROC_SYSCTL
 static int proc_do_cad_pid(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos);
@@ -403,6 +409,13 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= sched_rt_handler,
 	},
+	{
+		.procname	= "sched_rr_timeslice_ms",
+		.data		= &sched_rr_timeslice,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= sched_rr_handler,
+	},
 #ifdef CONFIG_SCHED_AUTOGROUP
 	{
 		.procname	= "sched_autogroup_enabled",
@@ -545,6 +558,8 @@ static struct ctl_table kern_table[] = {
 	 	.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+#endif
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
 	{
 		.procname	= "unaligned-trap",
 		.data		= &unaligned_enabled,
@@ -911,7 +926,7 @@ static struct ctl_table kern_table[] = {
 		.proc_handler	= proc_doulongvec_minmax,
 	},
 #endif
-#ifdef CONFIG_IA64
+#ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
 	{
 		.procname	= "ignore-unaligned-usertrap",
 		.data		= &no_unaligned_warning,
@@ -919,6 +934,8 @@ static struct ctl_table kern_table[] = {
 	 	.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
+#endif
+#ifdef CONFIG_IA64
 	{
 		.procname	= "unaligned-dump-stack",
 		.data		= &unaligned_dump_stack,
@@ -2006,7 +2023,7 @@ static int proc_taint(struct ctl_table *table, int write,
 		int i;
 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
 			if ((tmptaint >> i) & 1)
-				add_taint(i);
+				add_taint(i, LOCKDEP_STILL_OK);
 		}
 	}
 
@@ -2083,7 +2100,7 @@ int proc_dointvec_minmax(struct ctl_table *table, int write,
 static void validate_coredump_safety(void)
 {
 #ifdef CONFIG_COREDUMP
-	if (suid_dumpable == SUID_DUMPABLE_SAFE &&
+	if (suid_dumpable == SUID_DUMP_ROOT &&
 	    core_pattern[0] != '/' && core_pattern[0] != '|') {
 		printk(KERN_WARNING "Unsafe core_pattern used with "\
 			"suid_dumpable=2. Pipe handler or fully qualified "\
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 5a6384450501..ebf72358e86a 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -387,7 +387,6 @@ static const struct bin_table bin_net_ipv4_table[] = {
 	{ CTL_INT,	NET_TCP_MODERATE_RCVBUF,		"tcp_moderate_rcvbuf" },
 	{ CTL_INT,	NET_TCP_TSO_WIN_DIVISOR,		"tcp_tso_win_divisor" },
 	{ CTL_STR,	NET_TCP_CONG_CONTROL,			"tcp_congestion_control" },
-	{ CTL_INT,	NET_TCP_ABC,				"tcp_abc" },
 	{ CTL_INT,	NET_TCP_MTU_PROBING,			"tcp_mtu_probing" },
 	{ CTL_INT,	NET_TCP_BASE_MSS,			"tcp_base_mss" },
 	{ CTL_INT,	NET_IPV4_TCP_WORKAROUND_SIGNED_WINDOWS,	"tcp_workaround_signed_windows" },
@@ -971,7 +970,6 @@ out:
 static ssize_t bin_intvec(struct file *file,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
-	mm_segment_t old_fs = get_fs();
 	ssize_t copied = 0;
 	char *buffer;
 	ssize_t result;
@@ -984,13 +982,10 @@ static ssize_t bin_intvec(struct file *file,
 	if (oldval && oldlen) {
 		unsigned __user *vec = oldval;
 		size_t length = oldlen / sizeof(*vec);
-		loff_t pos = 0;
 		char *str, *end;
 		int i;
 
-		set_fs(KERNEL_DS);
-		result = vfs_read(file, buffer, BUFSZ - 1, &pos);
-		set_fs(old_fs);
+		result = kernel_read(file, 0, buffer, BUFSZ - 1);
 		if (result < 0)
 			goto out_kfree;
 
@@ -1017,7 +1012,6 @@ static ssize_t bin_intvec(struct file *file,
 	if (newval && newlen) {
 		unsigned __user *vec = newval;
 		size_t length = newlen / sizeof(*vec);
-		loff_t pos = 0;
 		char *str, *end;
 		int i;
 
@@ -1033,9 +1027,7 @@ static ssize_t bin_intvec(struct file *file,
 			str += snprintf(str, end - str, "%lu\t", value);
 		}
 
-		set_fs(KERNEL_DS);
-		result = vfs_write(file, buffer, str - buffer, &pos);
-		set_fs(old_fs);
+		result = kernel_write(file, buffer, str - buffer, 0);
 		if (result < 0)
 			goto out_kfree;
 	}
@@ -1049,7 +1041,6 @@ out:
 static ssize_t bin_ulongvec(struct file *file,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
-	mm_segment_t old_fs = get_fs();
 	ssize_t copied = 0;
 	char *buffer;
 	ssize_t result;
@@ -1062,13 +1053,10 @@ static ssize_t bin_ulongvec(struct file *file,
 	if (oldval && oldlen) {
 		unsigned long __user *vec = oldval;
 		size_t length = oldlen / sizeof(*vec);
-		loff_t pos = 0;
 		char *str, *end;
 		int i;
 
-		set_fs(KERNEL_DS);
-		result = vfs_read(file, buffer, BUFSZ - 1, &pos);
-		set_fs(old_fs);
+		result = kernel_read(file, 0, buffer, BUFSZ - 1);
 		if (result < 0)
 			goto out_kfree;
 
@@ -1095,7 +1083,6 @@ static ssize_t bin_ulongvec(struct file *file,
 	if (newval && newlen) {
 		unsigned long __user *vec = newval;
 		size_t length = newlen / sizeof(*vec);
-		loff_t pos = 0;
 		char *str, *end;
 		int i;
 
@@ -1111,9 +1098,7 @@ static ssize_t bin_ulongvec(struct file *file,
 			str += snprintf(str, end - str, "%lu\t", value);
 		}
 
-		set_fs(KERNEL_DS);
-		result = vfs_write(file, buffer, str - buffer, &pos);
-		set_fs(old_fs);
+		result = kernel_write(file, buffer, str - buffer, 0);
 		if (result < 0)
 			goto out_kfree;
 	}
@@ -1127,19 +1112,15 @@ out:
 static ssize_t bin_uuid(struct file *file,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
-	mm_segment_t old_fs = get_fs();
 	ssize_t result, copied = 0;
 
 	/* Only supports reads */
 	if (oldval && oldlen) {
-		loff_t pos = 0;
 		char buf[40], *str = buf;
 		unsigned char uuid[16];
 		int i;
 
-		set_fs(KERNEL_DS);
-		result = vfs_read(file, buf, sizeof(buf) - 1, &pos);
-		set_fs(old_fs);
+		result = kernel_read(file, 0, buf, sizeof(buf) - 1);
 		if (result < 0)
 			goto out;
 
@@ -1175,18 +1156,14 @@ out:
 static ssize_t bin_dn_node_address(struct file *file,
 	void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
 {
-	mm_segment_t old_fs = get_fs();
 	ssize_t result, copied = 0;
 
 	if (oldval && oldlen) {
-		loff_t pos = 0;
 		char buf[15], *nodep;
 		unsigned long area, node;
 		__le16 dnaddr;
 
-		set_fs(KERNEL_DS);
-		result = vfs_read(file, buf, sizeof(buf) - 1, &pos);
-		set_fs(old_fs);
+		result = kernel_read(file, 0, buf, sizeof(buf) - 1);
 		if (result < 0)
 			goto out;
 
@@ -1194,9 +1171,10 @@ static ssize_t bin_dn_node_address(struct file *file,
 
 		/* Convert the decnet address to binary */
 		result = -EIO;
-		nodep = strchr(buf, '.') + 1;
+		nodep = strchr(buf, '.');
 		if (!nodep)
 			goto out;
+		++nodep;
 
 		area = simple_strtoul(buf, NULL, 10);
 		node = simple_strtoul(nodep, NULL, 10);
@@ -1215,7 +1193,6 @@ static ssize_t bin_dn_node_address(struct file *file,
 	}
 
 	if (newval && newlen) {
-		loff_t pos = 0;
 		__le16 dnaddr;
 		char buf[15];
 		int len;
@@ -1232,9 +1209,7 @@ static ssize_t bin_dn_node_address(struct file *file,
 				le16_to_cpu(dnaddr) >> 10,
 				le16_to_cpu(dnaddr) & 0x3ff);
 
-		set_fs(KERNEL_DS);
-		result = vfs_write(file, buf, len, &pos);
-		set_fs(old_fs);
+		result = kernel_write(file, buf, len, 0);
 		if (result < 0)
 			goto out;
 	}
diff --git a/kernel/time.c b/kernel/time.c
index d226c6a3fd28..f8342a41efa6 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -115,6 +115,12 @@ SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv,
 }
 
 /*
+ * Indicates if there is an offset between the system clock and the hardware
+ * clock/persistent clock/rtc.
+ */
+int persistent_clock_is_local;
+
+/*
  * Adjust the time obtained from the CMOS to be UTC time instead of
  * local time.
  *
@@ -135,6 +141,8 @@ static inline void warp_clock(void)
 	struct timespec adjust;
 
 	adjust = current_kernel_time();
+	if (sys_tz.tz_minuteswest != 0)
+		persistent_clock_is_local = 1;
 	adjust.tv_sec += sys_tz.tz_minuteswest * 60;
 	do_settimeofday(&adjust);
 }
@@ -232,7 +240,7 @@ EXPORT_SYMBOL(current_fs_time);
  * Avoid unnecessary multiplications/divisions in the
  * two most common HZ cases:
  */
-inline unsigned int jiffies_to_msecs(const unsigned long j)
+unsigned int jiffies_to_msecs(const unsigned long j)
 {
 #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
 	return (MSEC_PER_SEC / HZ) * j;
@@ -248,7 +256,7 @@ inline unsigned int jiffies_to_msecs(const unsigned long j)
 }
 EXPORT_SYMBOL(jiffies_to_msecs);
 
-inline unsigned int jiffies_to_usecs(const unsigned long j)
+unsigned int jiffies_to_usecs(const unsigned long j)
 {
 #if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ)
 	return (USEC_PER_SEC / HZ) * j;
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 8601f0db1261..24510d84efd7 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -12,6 +12,11 @@ config CLOCKSOURCE_WATCHDOG
 config ARCH_CLOCKSOURCE_DATA
 	bool
 
+# Platforms has a persistent clock
+config ALWAYS_USE_PERSISTENT_CLOCK
+	bool
+	default n
+
 # Timekeeping vsyscall support
 config GENERIC_TIME_VSYSCALL
 	bool
@@ -38,6 +43,10 @@ config GENERIC_CLOCKEVENTS_BUILD
 	default y
 	depends on GENERIC_CLOCKEVENTS
 
+# Architecture can handle broadcast in a driver-agnostic way
+config ARCH_HAS_TICK_BROADCAST
+	bool
+
 # Clockevents broadcasting infrastructure
 config GENERIC_CLOCKEVENTS_BROADCAST
 	bool
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 30b6de0d977c..c6d6400ee137 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -339,6 +339,7 @@ void clockevents_config_and_register(struct clock_event_device *dev,
 	clockevents_config(dev, freq);
 	clockevents_register_device(dev);
 }
+EXPORT_SYMBOL_GPL(clockevents_config_and_register);
 
 /**
  * clockevents_update_freq - Update frequency and reprogram a clock event device.
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 24174b4d669b..072bb066bb7d 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -15,6 +15,7 @@
 #include <linux/time.h>
 #include <linux/mm.h>
 #include <linux/module.h>
+#include <linux/rtc.h>
 
 #include "tick-internal.h"
 
@@ -22,7 +23,7 @@
  * NTP timekeeping variables:
  */
 
-DEFINE_SPINLOCK(ntp_lock);
+DEFINE_RAW_SPINLOCK(ntp_lock);
 
 
 /* USER_HZ period (usecs): */
@@ -347,7 +348,7 @@ void ntp_clear(void)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&ntp_lock, flags);
+	raw_spin_lock_irqsave(&ntp_lock, flags);
 
 	time_adjust	= 0;		/* stop active adjtime() */
 	time_status	|= STA_UNSYNC;
@@ -361,7 +362,7 @@ void ntp_clear(void)
 
 	/* Clear PPS state variables */
 	pps_clear();
-	spin_unlock_irqrestore(&ntp_lock, flags);
+	raw_spin_unlock_irqrestore(&ntp_lock, flags);
 
 }
 
@@ -371,9 +372,9 @@ u64 ntp_tick_length(void)
 	unsigned long flags;
 	s64 ret;
 
-	spin_lock_irqsave(&ntp_lock, flags);
+	raw_spin_lock_irqsave(&ntp_lock, flags);
 	ret = tick_length;
-	spin_unlock_irqrestore(&ntp_lock, flags);
+	raw_spin_unlock_irqrestore(&ntp_lock, flags);
 	return ret;
 }
 
@@ -394,7 +395,7 @@ int second_overflow(unsigned long secs)
 	int leap = 0;
 	unsigned long flags;
 
-	spin_lock_irqsave(&ntp_lock, flags);
+	raw_spin_lock_irqsave(&ntp_lock, flags);
 
 	/*
 	 * Leap second processing. If in leap-insert state at the end of the
@@ -478,13 +479,12 @@ int second_overflow(unsigned long secs)
 	time_adjust = 0;
 
 out:
-	spin_unlock_irqrestore(&ntp_lock, flags);
+	raw_spin_unlock_irqrestore(&ntp_lock, flags);
 
 	return leap;
 }
 
-#ifdef CONFIG_GENERIC_CMOS_UPDATE
-
+#if defined(CONFIG_GENERIC_CMOS_UPDATE) || defined(CONFIG_RTC_SYSTOHC)
 static void sync_cmos_clock(struct work_struct *work);
 
 static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock);
@@ -510,14 +510,26 @@ static void sync_cmos_clock(struct work_struct *work)
 	}
 
 	getnstimeofday(&now);
-	if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
-		fail = update_persistent_clock(now);
+	if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2) {
+		struct timespec adjust = now;
+
+		fail = -ENODEV;
+		if (persistent_clock_is_local)
+			adjust.tv_sec -= (sys_tz.tz_minuteswest * 60);
+#ifdef CONFIG_GENERIC_CMOS_UPDATE
+		fail = update_persistent_clock(adjust);
+#endif
+#ifdef CONFIG_RTC_SYSTOHC
+		if (fail == -ENODEV)
+			fail = rtc_set_ntp_time(adjust);
+#endif
+	}
 
 	next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2);
 	if (next.tv_nsec <= 0)
 		next.tv_nsec += NSEC_PER_SEC;
 
-	if (!fail)
+	if (!fail || fail == -ENODEV)
 		next.tv_sec = 659;
 	else
 		next.tv_sec = 0;
@@ -660,7 +672,7 @@ int do_adjtimex(struct timex *txc)
 
 	getnstimeofday(&ts);
 
-	spin_lock_irq(&ntp_lock);
+	raw_spin_lock_irq(&ntp_lock);
 
 	if (txc->modes & ADJ_ADJTIME) {
 		long save_adjust = time_adjust;
@@ -702,7 +714,7 @@ int do_adjtimex(struct timex *txc)
 	/* fill PPS status fields */
 	pps_fill_timex(txc);
 
-	spin_unlock_irq(&ntp_lock);
+	raw_spin_unlock_irq(&ntp_lock);
 
 	txc->time.tv_sec = ts.tv_sec;
 	txc->time.tv_usec = ts.tv_nsec;
@@ -900,7 +912,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
 
 	pts_norm = pps_normalize_ts(*phase_ts);
 
-	spin_lock_irqsave(&ntp_lock, flags);
+	raw_spin_lock_irqsave(&ntp_lock, flags);
 
 	/* clear the error bits, they will be set again if needed */
 	time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
@@ -913,7 +925,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
 	 * just start the frequency interval */
 	if (unlikely(pps_fbase.tv_sec == 0)) {
 		pps_fbase = *raw_ts;
-		spin_unlock_irqrestore(&ntp_lock, flags);
+		raw_spin_unlock_irqrestore(&ntp_lock, flags);
 		return;
 	}
 
@@ -928,7 +940,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
 		time_status |= STA_PPSJITTER;
 		/* restart the frequency calibration interval */
 		pps_fbase = *raw_ts;
-		spin_unlock_irqrestore(&ntp_lock, flags);
+		raw_spin_unlock_irqrestore(&ntp_lock, flags);
 		pr_err("hardpps: PPSJITTER: bad pulse\n");
 		return;
 	}
@@ -945,7 +957,7 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
 
 	hardpps_update_phase(pts_norm.nsec);
 
-	spin_unlock_irqrestore(&ntp_lock, flags);
+	raw_spin_unlock_irqrestore(&ntp_lock, flags);
 }
 EXPORT_SYMBOL(hardpps);
 
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index f113755695e2..2fb8cb88df8d 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -18,6 +18,7 @@
 #include <linux/percpu.h>
 #include <linux/profile.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 
 #include "tick-internal.h"
 
@@ -86,6 +87,22 @@ int tick_is_broadcast_device(struct clock_event_device *dev)
 	return (dev && tick_broadcast_device.evtdev == dev);
 }
 
+static void err_broadcast(const struct cpumask *mask)
+{
+	pr_crit_once("Failed to broadcast timer tick. Some CPUs may be unresponsive.\n");
+}
+
+static void tick_device_setup_broadcast_func(struct clock_event_device *dev)
+{
+	if (!dev->broadcast)
+		dev->broadcast = tick_broadcast;
+	if (!dev->broadcast) {
+		pr_warn_once("%s depends on broadcast, but no broadcast function available\n",
+			     dev->name);
+		dev->broadcast = err_broadcast;
+	}
+}
+
 /*
  * Check, if the device is disfunctional and a place holder, which
  * needs to be handled by the broadcast device.
@@ -105,6 +122,7 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
 	 */
 	if (!tick_device_is_functional(dev)) {
 		dev->event_handler = tick_handle_periodic;
+		tick_device_setup_broadcast_func(dev);
 		cpumask_set_cpu(cpu, tick_get_broadcast_mask());
 		tick_broadcast_start_periodic(tick_broadcast_device.evtdev);
 		ret = 1;
@@ -116,15 +134,33 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
 		 */
 		if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) {
 			int cpu = smp_processor_id();
-
 			cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
 			tick_broadcast_clear_oneshot(cpu);
+		} else {
+			tick_device_setup_broadcast_func(dev);
 		}
 	}
 	raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
 	return ret;
 }
 
+#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
+int tick_receive_broadcast(void)
+{
+	struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
+	struct clock_event_device *evt = td->evtdev;
+
+	if (!evt)
+		return -ENODEV;
+
+	if (!evt->event_handler)
+		return -EINVAL;
+
+	evt->event_handler(evt);
+	return 0;
+}
+#endif
+
 /*
  * Broadcast the event to the cpus, which are set in the mask (mangled).
  */
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index d58e552d9fd1..a19a39952c1b 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -20,6 +20,7 @@
 #include <linux/profile.h>
 #include <linux/sched.h>
 #include <linux/module.h>
+#include <linux/irq_work.h>
 
 #include <asm/irq_regs.h>
 
@@ -28,7 +29,7 @@
 /*
  * Per cpu nohz control structure
  */
-static DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched);
+DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched);
 
 /*
  * The time, when the last jiffy update happened. Protected by jiffies_lock.
@@ -331,8 +332,8 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
 		time_delta = timekeeping_max_deferment();
 	} while (read_seqretry(&jiffies_lock, seq));
 
-	if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || printk_needs_cpu(cpu) ||
-	    arch_needs_cpu(cpu)) {
+	if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) ||
+	    arch_needs_cpu(cpu) || irq_work_needs_cpu()) {
 		next_jiffies = last_jiffies + 1;
 		delta_jiffies = 1;
 	} else {
@@ -553,6 +554,7 @@ void tick_nohz_idle_enter(void)
 
 	local_irq_enable();
 }
+EXPORT_SYMBOL_GPL(tick_nohz_idle_enter);
 
 /**
  * tick_nohz_irq_exit - update next tick event from interrupt exit
@@ -631,8 +633,11 @@ static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
 
 static void tick_nohz_account_idle_ticks(struct tick_sched *ts)
 {
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 	unsigned long ticks;
+
+	if (vtime_accounting_enabled())
+		return;
 	/*
 	 * We stopped the tick in idle. Update process times would miss the
 	 * time we slept as update_process_times does only a 1 tick
@@ -681,6 +686,7 @@ void tick_nohz_idle_exit(void)
 
 	local_irq_enable();
 }
+EXPORT_SYMBOL_GPL(tick_nohz_idle_exit);
 
 static int tick_nohz_reprogram(struct tick_sched *ts, ktime_t now)
 {
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index cbc6acb0db3f..9a0bc98fbe1d 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -29,6 +29,9 @@ static struct timekeeper timekeeper;
 /* flag for if timekeeping is suspended */
 int __read_mostly timekeeping_suspended;
 
+/* Flag for if there is a persistent clock on this platform */
+bool __read_mostly persistent_clock_exist = false;
+
 static inline void tk_normalize_xtime(struct timekeeper *tk)
 {
 	while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) {
@@ -135,6 +138,20 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
 }
 
 /* Timekeeper helper functions. */
+
+#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
+u32 (*arch_gettimeoffset)(void);
+
+u32 get_arch_timeoffset(void)
+{
+	if (likely(arch_gettimeoffset))
+		return arch_gettimeoffset();
+	return 0;
+}
+#else
+static inline u32 get_arch_timeoffset(void) { return 0; }
+#endif
+
 static inline s64 timekeeping_get_ns(struct timekeeper *tk)
 {
 	cycle_t cycle_now, cycle_delta;
@@ -151,8 +168,8 @@ static inline s64 timekeeping_get_ns(struct timekeeper *tk)
 	nsec = cycle_delta * tk->mult + tk->xtime_nsec;
 	nsec >>= tk->shift;
 
-	/* If arch requires, add in gettimeoffset() */
-	return nsec + arch_gettimeoffset();
+	/* If arch requires, add in get_arch_timeoffset() */
+	return nsec + get_arch_timeoffset();
 }
 
 static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
@@ -171,8 +188,8 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
 	/* convert delta to nanoseconds. */
 	nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
 
-	/* If arch requires, add in gettimeoffset() */
-	return nsec + arch_gettimeoffset();
+	/* If arch requires, add in get_arch_timeoffset() */
+	return nsec + get_arch_timeoffset();
 }
 
 static RAW_NOTIFIER_HEAD(pvclock_gtod_chain);
@@ -254,8 +271,8 @@ static void timekeeping_forward_now(struct timekeeper *tk)
 
 	tk->xtime_nsec += cycle_delta * tk->mult;
 
-	/* If arch requires, add in gettimeoffset() */
-	tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift;
+	/* If arch requires, add in get_arch_timeoffset() */
+	tk->xtime_nsec += (u64)get_arch_timeoffset() << tk->shift;
 
 	tk_normalize_xtime(tk);
 
@@ -264,19 +281,18 @@ static void timekeeping_forward_now(struct timekeeper *tk)
 }
 
 /**
- * getnstimeofday - Returns the time of day in a timespec
+ * __getnstimeofday - Returns the time of day in a timespec.
  * @ts:		pointer to the timespec to be set
  *
- * Returns the time of day in a timespec.
+ * Updates the time of day in the timespec.
+ * Returns 0 on success, or -ve when suspended (timespec will be undefined).
  */
-void getnstimeofday(struct timespec *ts)
+int __getnstimeofday(struct timespec *ts)
 {
 	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	s64 nsecs = 0;
 
-	WARN_ON(timekeeping_suspended);
-
 	do {
 		seq = read_seqbegin(&tk->lock);
 
@@ -287,6 +303,26 @@ void getnstimeofday(struct timespec *ts)
 
 	ts->tv_nsec = 0;
 	timespec_add_ns(ts, nsecs);
+
+	/*
+	 * Do not bail out early, in case there were callers still using
+	 * the value, even in the face of the WARN_ON.
+	 */
+	if (unlikely(timekeeping_suspended))
+		return -EAGAIN;
+	return 0;
+}
+EXPORT_SYMBOL(__getnstimeofday);
+
+/**
+ * getnstimeofday - Returns the time of day in a timespec.
+ * @ts:		pointer to the timespec to be set
+ *
+ * Returns the time of day in a timespec (WARN if suspended).
+ */
+void getnstimeofday(struct timespec *ts)
+{
+	WARN_ON(__getnstimeofday(ts));
 }
 EXPORT_SYMBOL(getnstimeofday);
 
@@ -640,12 +676,14 @@ void __init timekeeping_init(void)
 	struct timespec now, boot, tmp;
 
 	read_persistent_clock(&now);
+
 	if (!timespec_valid_strict(&now)) {
 		pr_warn("WARNING: Persistent clock returned invalid value!\n"
 			"         Check your CMOS/BIOS settings.\n");
 		now.tv_sec = 0;
 		now.tv_nsec = 0;
-	}
+	} else if (now.tv_sec || now.tv_nsec)
+		persistent_clock_exist = true;
 
 	read_boot_clock(&boot);
 	if (!timespec_valid_strict(&boot)) {
@@ -718,11 +756,12 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
 {
 	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
-	struct timespec ts;
 
-	/* Make sure we don't set the clock twice */
-	read_persistent_clock(&ts);
-	if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
+	/*
+	 * Make sure we don't set the clock twice, as timekeeping_resume()
+	 * already did it
+	 */
+	if (has_persistent_clock())
 		return;
 
 	write_seqlock_irqsave(&tk->lock, flags);
diff --git a/kernel/timeconst.bc b/kernel/timeconst.bc
new file mode 100644
index 000000000000..511bdf2cafda
--- /dev/null
+++ b/kernel/timeconst.bc
@@ -0,0 +1,108 @@
+scale=0
+
+define gcd(a,b) {
+	auto t;
+	while (b) {
+		t = b;
+		b = a % b;
+		a = t;
+	}
+	return a;
+}
+
+/* Division by reciprocal multiplication. */
+define fmul(b,n,d) {
+       return (2^b*n+d-1)/d;
+}
+
+/* Adjustment factor when a ceiling value is used.  Use as:
+   (imul * n) + (fmulxx * n + fadjxx) >> xx) */
+define fadj(b,n,d) {
+	auto v;
+	d = d/gcd(n,d);
+	v = 2^b*(d-1)/d;
+	return v;
+}
+
+/* Compute the appropriate mul/adj values as well as a shift count,
+   which brings the mul value into the range 2^b-1 <= x < 2^b.  Such
+   a shift value will be correct in the signed integer range and off
+   by at most one in the upper half of the unsigned range. */
+define fmuls(b,n,d) {
+	auto s, m;
+	for (s = 0; 1; s++) {
+		m = fmul(s,n,d);
+		if (m >= 2^(b-1))
+			return s;
+	}
+	return 0;
+}
+
+define timeconst(hz) {
+	print "/* Automatically generated by kernel/timeconst.bc */\n"
+	print "/* Time conversion constants for HZ == ", hz, " */\n"
+	print "\n"
+
+	print "#ifndef KERNEL_TIMECONST_H\n"
+	print "#define KERNEL_TIMECONST_H\n\n"
+
+	print "#include <linux/param.h>\n"
+	print "#include <linux/types.h>\n\n"
+
+	print "#if HZ != ", hz, "\n"
+	print "#error \qkernel/timeconst.h has the wrong HZ value!\q\n"
+	print "#endif\n\n"
+
+	if (hz < 2) {
+		print "#error Totally bogus HZ value!\n"
+	} else {
+		s=fmuls(32,1000,hz)
+		obase=16
+		print "#define HZ_TO_MSEC_MUL32\tU64_C(0x", fmul(s,1000,hz), ")\n"
+		print "#define HZ_TO_MSEC_ADJ32\tU64_C(0x", fadj(s,1000,hz), ")\n"
+		obase=10
+		print "#define HZ_TO_MSEC_SHR32\t", s, "\n"
+
+		s=fmuls(32,hz,1000)
+		obase=16
+		print "#define MSEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000), ")\n"
+		print "#define MSEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000), ")\n"
+		obase=10
+		print "#define MSEC_TO_HZ_SHR32\t", s, "\n"
+
+		obase=10
+		cd=gcd(hz,1000)
+		print "#define HZ_TO_MSEC_NUM\t\t", 1000/cd, "\n"
+		print "#define HZ_TO_MSEC_DEN\t\t", hz/cd, "\n"
+		print "#define MSEC_TO_HZ_NUM\t\t", hz/cd, "\n"
+		print "#define MSEC_TO_HZ_DEN\t\t", 1000/cd, "\n"
+		print "\n"
+
+		s=fmuls(32,1000000,hz)
+		obase=16
+		print "#define HZ_TO_USEC_MUL32\tU64_C(0x", fmul(s,1000000,hz), ")\n"
+		print "#define HZ_TO_USEC_ADJ32\tU64_C(0x", fadj(s,1000000,hz), ")\n"
+		obase=10
+		print "#define HZ_TO_USEC_SHR32\t", s, "\n"
+
+		s=fmuls(32,hz,1000000)
+		obase=16
+		print "#define USEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000000), ")\n"
+		print "#define USEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000000), ")\n"
+		obase=10
+		print "#define USEC_TO_HZ_SHR32\t", s, "\n"
+
+		obase=10
+		cd=gcd(hz,1000000)
+		print "#define HZ_TO_USEC_NUM\t\t", 1000000/cd, "\n"
+		print "#define HZ_TO_USEC_DEN\t\t", hz/cd, "\n"
+		print "#define USEC_TO_HZ_NUM\t\t", hz/cd, "\n"
+		print "#define USEC_TO_HZ_DEN\t\t", 1000000/cd, "\n"
+		print "\n"
+
+		print "#endif /* KERNEL_TIMECONST_H */\n"
+	}
+	halt
+}
+
+timeconst(hz)
diff --git a/kernel/timeconst.pl b/kernel/timeconst.pl
deleted file mode 100644
index eb51d76e058a..000000000000
--- a/kernel/timeconst.pl
+++ /dev/null
@@ -1,378 +0,0 @@
-#!/usr/bin/perl
-# -----------------------------------------------------------------------
-#
-#   Copyright 2007-2008 rPath, Inc. - All Rights Reserved
-#
-#   This file is part of the Linux kernel, and is made available under
-#   the terms of the GNU General Public License version 2 or (at your
-#   option) any later version; incorporated herein by reference.
-#
-# -----------------------------------------------------------------------
-#
-
-#
-# Usage: timeconst.pl HZ > timeconst.h
-#
-
-# Precomputed values for systems without Math::BigInt
-# Generated by:
-# timeconst.pl --can 24 32 48 64 100 122 128 200 250 256 300 512 1000 1024 1200
-%canned_values = (
-	24 => [
-		'0xa6aaaaab','0x2aaaaaa',26,
-		125,3,
-		'0xc49ba5e4','0x1fbe76c8b4',37,
-		3,125,
-		'0xa2c2aaab','0xaaaa',16,
-		125000,3,
-		'0xc9539b89','0x7fffbce4217d',47,
-		3,125000,
-	], 32 => [
-		'0xfa000000','0x6000000',27,
-		125,4,
-		'0x83126e98','0xfdf3b645a',36,
-		4,125,
-		'0xf4240000','0x0',17,
-		31250,1,
-		'0x8637bd06','0x3fff79c842fa',46,
-		1,31250,
-	], 48 => [
-		'0xa6aaaaab','0x6aaaaaa',27,
-		125,6,
-		'0xc49ba5e4','0xfdf3b645a',36,
-		6,125,
-		'0xa2c2aaab','0x15555',17,
-		62500,3,
-		'0xc9539b89','0x3fffbce4217d',46,
-		3,62500,
-	], 64 => [
-		'0xfa000000','0xe000000',28,
-		125,8,
-		'0x83126e98','0x7ef9db22d',35,
-		8,125,
-		'0xf4240000','0x0',18,
-		15625,1,
-		'0x8637bd06','0x1fff79c842fa',45,
-		1,15625,
-	], 100 => [
-		'0xa0000000','0x0',28,
-		10,1,
-		'0xcccccccd','0x733333333',35,
-		1,10,
-		'0x9c400000','0x0',18,
-		10000,1,
-		'0xd1b71759','0x1fff2e48e8a7',45,
-		1,10000,
-	], 122 => [
-		'0x8325c53f','0xfbcda3a',28,
-		500,61,
-		'0xf9db22d1','0x7fbe76c8b',35,
-		61,500,
-		'0x8012e2a0','0x3ef36',18,
-		500000,61,
-		'0xffda4053','0x1ffffbce4217',45,
-		61,500000,
-	], 128 => [
-		'0xfa000000','0x1e000000',29,
-		125,16,
-		'0x83126e98','0x3f7ced916',34,
-		16,125,
-		'0xf4240000','0x40000',19,
-		15625,2,
-		'0x8637bd06','0xfffbce4217d',44,
-		2,15625,
-	], 200 => [
-		'0xa0000000','0x0',29,
-		5,1,
-		'0xcccccccd','0x333333333',34,
-		1,5,
-		'0x9c400000','0x0',19,
-		5000,1,
-		'0xd1b71759','0xfff2e48e8a7',44,
-		1,5000,
-	], 250 => [
-		'0x80000000','0x0',29,
-		4,1,
-		'0x80000000','0x180000000',33,
-		1,4,
-		'0xfa000000','0x0',20,
-		4000,1,
-		'0x83126e98','0x7ff7ced9168',43,
-		1,4000,
-	], 256 => [
-		'0xfa000000','0x3e000000',30,
-		125,32,
-		'0x83126e98','0x1fbe76c8b',33,
-		32,125,
-		'0xf4240000','0xc0000',20,
-		15625,4,
-		'0x8637bd06','0x7ffde7210be',43,
-		4,15625,
-	], 300 => [
-		'0xd5555556','0x2aaaaaaa',30,
-		10,3,
-		'0x9999999a','0x1cccccccc',33,
-		3,10,
-		'0xd0555556','0xaaaaa',20,
-		10000,3,
-		'0x9d495183','0x7ffcb923a29',43,
-		3,10000,
-	], 512 => [
-		'0xfa000000','0x7e000000',31,
-		125,64,
-		'0x83126e98','0xfdf3b645',32,
-		64,125,
-		'0xf4240000','0x1c0000',21,
-		15625,8,
-		'0x8637bd06','0x3ffef39085f',42,
-		8,15625,
-	], 1000 => [
-		'0x80000000','0x0',31,
-		1,1,
-		'0x80000000','0x0',31,
-		1,1,
-		'0xfa000000','0x0',22,
-		1000,1,
-		'0x83126e98','0x1ff7ced9168',41,
-		1,1000,
-	], 1024 => [
-		'0xfa000000','0xfe000000',32,
-		125,128,
-		'0x83126e98','0x7ef9db22',31,
-		128,125,
-		'0xf4240000','0x3c0000',22,
-		15625,16,
-		'0x8637bd06','0x1fff79c842f',41,
-		16,15625,
-	], 1200 => [
-		'0xd5555556','0xd5555555',32,
-		5,6,
-		'0x9999999a','0x66666666',31,
-		6,5,
-		'0xd0555556','0x2aaaaa',22,
-		2500,3,
-		'0x9d495183','0x1ffcb923a29',41,
-		3,2500,
-	]
-);
-
-$has_bigint = eval 'use Math::BigInt qw(bgcd); 1;';
-
-sub bint($)
-{
-	my($x) = @_;
-	return Math::BigInt->new($x);
-}
-
-#
-# Constants for division by reciprocal multiplication.
-# (bits, numerator, denominator)
-#
-sub fmul($$$)
-{
-	my ($b,$n,$d) = @_;
-
-	$n = bint($n);
-	$d = bint($d);
-
-	return scalar (($n << $b)+$d-bint(1))/$d;
-}
-
-sub fadj($$$)
-{
-	my($b,$n,$d) = @_;
-
-	$n = bint($n);
-	$d = bint($d);
-
-	$d = $d/bgcd($n, $d);
-	return scalar (($d-bint(1)) << $b)/$d;
-}
-
-sub fmuls($$$) {
-	my($b,$n,$d) = @_;
-	my($s,$m);
-	my($thres) = bint(1) << ($b-1);
-
-	$n = bint($n);
-	$d = bint($d);
-
-	for ($s = 0; 1; $s++) {
-		$m = fmul($s,$n,$d);
-		return $s if ($m >= $thres);
-	}
-	return 0;
-}
-
-# Generate a hex value if the result fits in 64 bits;
-# otherwise skip.
-sub bignum_hex($) {
-	my($x) = @_;
-	my $s = $x->as_hex();
-
-	return (length($s) > 18) ? undef : $s;
-}
-
-# Provides mul, adj, and shr factors for a specific
-# (bit, time, hz) combination
-sub muladj($$$) {
-	my($b, $t, $hz) = @_;
-	my $s = fmuls($b, $t, $hz);
-	my $m = fmul($s, $t, $hz);
-	my $a = fadj($s, $t, $hz);
-	return (bignum_hex($m), bignum_hex($a), $s);
-}
-
-# Provides numerator, denominator values
-sub numden($$) {
-	my($n, $d) = @_;
-	my $g = bgcd($n, $d);
-	return ($n/$g, $d/$g);
-}
-
-# All values for a specific (time, hz) combo
-sub conversions($$) {
-	my ($t, $hz) = @_;
-	my @val = ();
-
-	# HZ_TO_xx
-	push(@val, muladj(32, $t, $hz));
-	push(@val, numden($t, $hz));
-
-	# xx_TO_HZ
-	push(@val, muladj(32, $hz, $t));
-	push(@val, numden($hz, $t));
-
-	return @val;
-}
-
-sub compute_values($) {
-	my($hz) = @_;
-	my @val = ();
-	my $s, $m, $a, $g;
-
-	if (!$has_bigint) {
-		die "$0: HZ == $hz not canned and ".
-		    "Math::BigInt not available\n";
-	}
-
-	# MSEC conversions
-	push(@val, conversions(1000, $hz));
-
-	# USEC conversions
-	push(@val, conversions(1000000, $hz));
-
-	return @val;
-}
-
-sub outputval($$)
-{
-	my($name, $val) = @_;
-	my $csuf;
-
-	if (defined($val)) {
-	    if ($name !~ /SHR/) {
-		$val = "U64_C($val)";
-	    }
-	    printf "#define %-23s %s\n", $name.$csuf, $val.$csuf;
-	}
-}
-
-sub output($@)
-{
-	my($hz, @val) = @_;
-	my $pfx, $bit, $suf, $s, $m, $a;
-
-	print "/* Automatically generated by kernel/timeconst.pl */\n";
-	print "/* Conversion constants for HZ == $hz */\n";
-	print "\n";
-	print "#ifndef KERNEL_TIMECONST_H\n";
-	print "#define KERNEL_TIMECONST_H\n";
-	print "\n";
-
-	print "#include <linux/param.h>\n";
-	print "#include <linux/types.h>\n";
-
-	print "\n";
-	print "#if HZ != $hz\n";
-	print "#error \"kernel/timeconst.h has the wrong HZ value!\"\n";
-	print "#endif\n";
-	print "\n";
-
-	foreach $pfx ('HZ_TO_MSEC','MSEC_TO_HZ',
-		      'HZ_TO_USEC','USEC_TO_HZ') {
-		foreach $bit (32) {
-			foreach $suf ('MUL', 'ADJ', 'SHR') {
-				outputval("${pfx}_$suf$bit", shift(@val));
-			}
-		}
-		foreach $suf ('NUM', 'DEN') {
-			outputval("${pfx}_$suf", shift(@val));
-		}
-	}
-
-	print "\n";
-	print "#endif /* KERNEL_TIMECONST_H */\n";
-}
-
-# Pretty-print Perl values
-sub perlvals(@) {
-	my $v;
-	my @l = ();
-
-	foreach $v (@_) {
-		if (!defined($v)) {
-			push(@l, 'undef');
-		} elsif ($v =~ /^0x/) {
-			push(@l, "\'".$v."\'");
-		} else {
-			push(@l, $v.'');
-		}
-	}
-	return join(',', @l);
-}
-
-($hz) = @ARGV;
-
-# Use this to generate the %canned_values structure
-if ($hz eq '--can') {
-	shift(@ARGV);
-	@hzlist = sort {$a <=> $b} (@ARGV);
-
-	print "# Precomputed values for systems without Math::BigInt\n";
-	print "# Generated by:\n";
-	print "# timeconst.pl --can ", join(' ', @hzlist), "\n";
-	print "\%canned_values = (\n";
-	my $pf = "\t";
-	foreach $hz (@hzlist) {
-		my @values = compute_values($hz);
-		print "$pf$hz => [\n";
-		while (scalar(@values)) {
-			my $bit;
-			foreach $bit (32) {
-				my $m = shift(@values);
-				my $a = shift(@values);
-				my $s = shift(@values);
-				print "\t\t", perlvals($m,$a,$s), ",\n";
-			}
-			my $n = shift(@values);
-			my $d = shift(@values);
-			print "\t\t", perlvals($n,$d), ",\n";
-		}
-		print "\t]";
-		$pf = ', ';
-	}
-	print "\n);\n";
-} else {
-	$hz += 0;			# Force to number
-	if ($hz < 1) {
-		die "Usage: $0 HZ\n";
-	}
-
-	@val = @{$canned_values{$hz}};
-	if (!defined(@val)) {
-		@val = compute_values($hz);
-	}
-	output($hz, @val);
-}
-exit 0;
diff --git a/kernel/timer.c b/kernel/timer.c
index 367d00858482..dbf7a78a1ef1 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -39,6 +39,7 @@
 #include <linux/kallsyms.h>
 #include <linux/irq_work.h>
 #include <linux/sched.h>
+#include <linux/sched/sysctl.h>
 #include <linux/slab.h>
 
 #include <asm/uaccess.h>
@@ -1351,7 +1352,6 @@ void update_process_times(int user_tick)
 	account_process_tick(p, user_tick);
 	run_local_timers();
 	rcu_check_callbacks(cpu, user_tick);
-	printk_tick();
 #ifdef CONFIG_IRQ_WORK
 	if (in_irq())
 		irq_work_run();
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 5d89335a485f..fc382d6e2765 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -39,6 +39,9 @@ config HAVE_DYNAMIC_FTRACE
 	help
 	  See Documentation/trace/ftrace-design.txt
 
+config HAVE_DYNAMIC_FTRACE_WITH_REGS
+	bool
+
 config HAVE_FTRACE_MCOUNT_RECORD
 	bool
 	help
@@ -78,21 +81,6 @@ config EVENT_TRACING
 	select CONTEXT_SWITCH_TRACER
 	bool
 
-config EVENT_POWER_TRACING_DEPRECATED
-	depends on EVENT_TRACING
-	bool "Deprecated power event trace API, to be removed"
-	default y
-	help
-	  Provides old power event types:
-	  C-state/idle accounting events:
-	  power:power_start
-	  power:power_end
-	  and old cpufreq accounting event:
-	  power:power_frequency
-	  This is for userspace compatibility
-	  and will vanish after 5 kernel iterations,
-	  namely 3.1.
-
 config CONTEXT_SWITCH_TRACER
 	bool
 
@@ -250,6 +238,16 @@ config FTRACE_SYSCALLS
 	help
 	  Basic tracer to catch the syscall entry and exit events.
 
+config TRACER_SNAPSHOT
+	bool "Create a snapshot trace buffer"
+	select TRACER_MAX_TRACE
+	help
+	  Allow tracing users to take snapshot of the current buffer using the
+	  ftrace interface, e.g.:
+
+	      echo 1 > /sys/kernel/debug/tracing/snapshot
+	      cat snapshot
+
 config TRACE_BRANCH_PROFILING
 	bool
 	select GENERIC_TRACER
@@ -416,23 +414,32 @@ config PROBE_EVENTS
 	def_bool n
 
 config DYNAMIC_FTRACE
-	bool "enable/disable ftrace tracepoints dynamically"
+	bool "enable/disable function tracing dynamically"
 	depends on FUNCTION_TRACER
 	depends on HAVE_DYNAMIC_FTRACE
 	default y
 	help
-          This option will modify all the calls to ftrace dynamically
-	  (will patch them out of the binary image and replace them
-	  with a No-Op instruction) as they are called. A table is
-	  created to dynamically enable them again.
+	  This option will modify all the calls to function tracing
+	  dynamically (will patch them out of the binary image and
+	  replace them with a No-Op instruction) on boot up. During
+	  compile time, a table is made of all the locations that ftrace
+	  can function trace, and this table is linked into the kernel
+	  image. When this is enabled, functions can be individually
+	  enabled, and the functions not enabled will not affect
+	  performance of the system.
+
+	  See the files in /sys/kernel/debug/tracing:
+	    available_filter_functions
+	    set_ftrace_filter
+	    set_ftrace_notrace
 
 	  This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but
 	  otherwise has native performance as long as no tracing is active.
 
-	  The changes to the code are done by a kernel thread that
-	  wakes up once a second and checks to see if any ftrace calls
-	  were made. If so, it runs stop_machine (stops all CPUS)
-	  and modifies the code to jump over the call to ftrace.
+config DYNAMIC_FTRACE_WITH_REGS
+	def_bool y
+	depends on DYNAMIC_FTRACE
+	depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
 
 config FUNCTION_PROFILER
 	bool "Kernel function profiler"
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index c0bd0308741c..9e5b8c272eec 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -147,7 +147,7 @@ void __trace_note_message(struct blk_trace *bt, const char *fmt, ...)
 		return;
 
 	local_irq_save(flags);
-	buf = per_cpu_ptr(bt->msg_data, smp_processor_id());
+	buf = this_cpu_ptr(bt->msg_data);
 	va_start(args, fmt);
 	n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
 	va_end(args);
@@ -739,6 +739,12 @@ static void blk_add_trace_rq_complete(void *ignore,
 				      struct request_queue *q,
 				      struct request *rq)
 {
+	struct blk_trace *bt = q->blk_trace;
+
+	/* if control ever passes through here, it's a request based driver */
+	if (unlikely(bt && !bt->rq_based))
+		bt->rq_based = true;
+
 	blk_add_trace_rq(q, rq, BLK_TA_COMPLETE);
 }
 
@@ -774,15 +780,30 @@ static void blk_add_trace_bio_bounce(void *ignore,
 	blk_add_trace_bio(q, bio, BLK_TA_BOUNCE, 0);
 }
 
-static void blk_add_trace_bio_complete(void *ignore,
-				       struct request_queue *q, struct bio *bio,
-				       int error)
+static void blk_add_trace_bio_complete(void *ignore, struct bio *bio, int error)
 {
+	struct request_queue *q;
+	struct blk_trace *bt;
+
+	if (!bio->bi_bdev)
+		return;
+
+	q = bdev_get_queue(bio->bi_bdev);
+	bt = q->blk_trace;
+
+	/*
+	 * Request based drivers will generate both rq and bio completions.
+	 * Ignore bio ones.
+	 */
+	if (likely(!bt) || bt->rq_based)
+		return;
+
 	blk_add_trace_bio(q, bio, BLK_TA_COMPLETE, error);
 }
 
 static void blk_add_trace_bio_backmerge(void *ignore,
 					struct request_queue *q,
+					struct request *rq,
 					struct bio *bio)
 {
 	blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE, 0);
@@ -790,6 +811,7 @@ static void blk_add_trace_bio_backmerge(void *ignore,
 
 static void blk_add_trace_bio_frontmerge(void *ignore,
 					 struct request_queue *q,
+					 struct request *rq,
 					 struct bio *bio)
 {
 	blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE, 0);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 41473b4ad7a4..ab25b88aae56 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -111,6 +111,26 @@ static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
 #endif
 
+/*
+ * Traverse the ftrace_global_list, invoking all entries.  The reason that we
+ * can use rcu_dereference_raw() is that elements removed from this list
+ * are simply leaked, so there is no need to interact with a grace-period
+ * mechanism.  The rcu_dereference_raw() calls are needed to handle
+ * concurrent insertions into the ftrace_global_list.
+ *
+ * Silly Alpha and silly pointer-speculation compiler optimizations!
+ */
+#define do_for_each_ftrace_op(op, list)			\
+	op = rcu_dereference_raw(list);			\
+	do
+
+/*
+ * Optimized for just a single item in the list (as that is the normal case).
+ */
+#define while_for_each_ftrace_op(op)				\
+	while (likely(op = rcu_dereference_raw((op)->next)) &&	\
+	       unlikely((op) != &ftrace_list_end))
+
 /**
  * ftrace_nr_registered_ops - return number of ops registered
  *
@@ -132,29 +152,21 @@ int ftrace_nr_registered_ops(void)
 	return cnt;
 }
 
-/*
- * Traverse the ftrace_global_list, invoking all entries.  The reason that we
- * can use rcu_dereference_raw() is that elements removed from this list
- * are simply leaked, so there is no need to interact with a grace-period
- * mechanism.  The rcu_dereference_raw() calls are needed to handle
- * concurrent insertions into the ftrace_global_list.
- *
- * Silly Alpha and silly pointer-speculation compiler optimizations!
- */
 static void
 ftrace_global_list_func(unsigned long ip, unsigned long parent_ip,
 			struct ftrace_ops *op, struct pt_regs *regs)
 {
-	if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
+	int bit;
+
+	bit = trace_test_and_set_recursion(TRACE_GLOBAL_START, TRACE_GLOBAL_MAX);
+	if (bit < 0)
 		return;
 
-	trace_recursion_set(TRACE_GLOBAL_BIT);
-	op = rcu_dereference_raw(ftrace_global_list); /*see above*/
-	while (op != &ftrace_list_end) {
+	do_for_each_ftrace_op(op, ftrace_global_list) {
 		op->func(ip, parent_ip, op, regs);
-		op = rcu_dereference_raw(op->next); /*see above*/
-	};
-	trace_recursion_clear(TRACE_GLOBAL_BIT);
+	} while_for_each_ftrace_op(op);
+
+	trace_clear_recursion(bit);
 }
 
 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
@@ -221,10 +233,24 @@ static void update_global_ops(void)
 	 * registered callers.
 	 */
 	if (ftrace_global_list == &ftrace_list_end ||
-	    ftrace_global_list->next == &ftrace_list_end)
+	    ftrace_global_list->next == &ftrace_list_end) {
 		func = ftrace_global_list->func;
-	else
+		/*
+		 * As we are calling the function directly.
+		 * If it does not have recursion protection,
+		 * the function_trace_op needs to be updated
+		 * accordingly.
+		 */
+		if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE)
+			global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
+		else
+			global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE;
+	} else {
 		func = ftrace_global_list_func;
+		/* The list has its own recursion protection. */
+		global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
+	}
+
 
 	/* If we filter on pids, update to use the pid function */
 	if (!list_empty(&ftrace_pids)) {
@@ -337,7 +363,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
 	if ((ops->flags & FL_GLOBAL_CONTROL_MASK) == FL_GLOBAL_CONTROL_MASK)
 		return -EINVAL;
 
-#ifndef ARCH_SUPPORTS_FTRACE_SAVE_REGS
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	/*
 	 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
 	 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
@@ -736,7 +762,6 @@ ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
 {
 	struct ftrace_profile *rec;
 	struct hlist_head *hhd;
-	struct hlist_node *n;
 	unsigned long key;
 
 	key = hash_long(ip, ftrace_profile_bits);
@@ -745,7 +770,7 @@ ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
 	if (hlist_empty(hhd))
 		return NULL;
 
-	hlist_for_each_entry_rcu(rec, n, hhd, node) {
+	hlist_for_each_entry_rcu(rec, hhd, node) {
 		if (rec->ip == ip)
 			return rec;
 	}
@@ -1107,7 +1132,6 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
 	unsigned long key;
 	struct ftrace_func_entry *entry;
 	struct hlist_head *hhd;
-	struct hlist_node *n;
 
 	if (ftrace_hash_empty(hash))
 		return NULL;
@@ -1119,7 +1143,7 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
 
 	hhd = &hash->buckets[key];
 
-	hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
+	hlist_for_each_entry_rcu(entry, hhd, hlist) {
 		if (entry->ip == ip)
 			return entry;
 	}
@@ -1176,7 +1200,7 @@ remove_hash_entry(struct ftrace_hash *hash,
 static void ftrace_hash_clear(struct ftrace_hash *hash)
 {
 	struct hlist_head *hhd;
-	struct hlist_node *tp, *tn;
+	struct hlist_node *tn;
 	struct ftrace_func_entry *entry;
 	int size = 1 << hash->size_bits;
 	int i;
@@ -1186,7 +1210,7 @@ static void ftrace_hash_clear(struct ftrace_hash *hash)
 
 	for (i = 0; i < size; i++) {
 		hhd = &hash->buckets[i];
-		hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
+		hlist_for_each_entry_safe(entry, tn, hhd, hlist)
 			free_hash_entry(hash, entry);
 	}
 	FTRACE_WARN_ON(hash->count);
@@ -1249,7 +1273,6 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
 {
 	struct ftrace_func_entry *entry;
 	struct ftrace_hash *new_hash;
-	struct hlist_node *tp;
 	int size;
 	int ret;
 	int i;
@@ -1264,7 +1287,7 @@ alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
 
 	size = 1 << hash->size_bits;
 	for (i = 0; i < size; i++) {
-		hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) {
+		hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
 			ret = add_hash_entry(new_hash, entry->ip);
 			if (ret < 0)
 				goto free_hash;
@@ -1290,7 +1313,7 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
 		 struct ftrace_hash **dst, struct ftrace_hash *src)
 {
 	struct ftrace_func_entry *entry;
-	struct hlist_node *tp, *tn;
+	struct hlist_node *tn;
 	struct hlist_head *hhd;
 	struct ftrace_hash *old_hash;
 	struct ftrace_hash *new_hash;
@@ -1336,7 +1359,7 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
 	size = 1 << src->size_bits;
 	for (i = 0; i < size; i++) {
 		hhd = &src->buckets[i];
-		hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) {
+		hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
 			if (bits > 0)
 				key = hash_long(entry->ip, bits);
 			else
@@ -2875,7 +2898,6 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
 {
 	struct ftrace_func_probe *entry;
 	struct hlist_head *hhd;
-	struct hlist_node *n;
 	unsigned long key;
 
 	key = hash_long(ip, FTRACE_HASH_BITS);
@@ -2891,7 +2913,7 @@ static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
 	 * on the hash. rcu_read_lock is too dangerous here.
 	 */
 	preempt_disable_notrace();
-	hlist_for_each_entry_rcu(entry, n, hhd, node) {
+	hlist_for_each_entry_rcu(entry, hhd, node) {
 		if (entry->ip == ip)
 			entry->ops->func(ip, parent_ip, &entry->data);
 	}
@@ -3042,7 +3064,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 				  void *data, int flags)
 {
 	struct ftrace_func_probe *entry;
-	struct hlist_node *n, *tmp;
+	struct hlist_node *tmp;
 	char str[KSYM_SYMBOL_LEN];
 	int type = MATCH_FULL;
 	int i, len = 0;
@@ -3065,7 +3087,7 @@ __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
 	for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) {
 		struct hlist_head *hhd = &ftrace_func_hash[i];
 
-		hlist_for_each_entry_safe(entry, n, tmp, hhd, node) {
+		hlist_for_each_entry_safe(entry, tmp, hhd, node) {
 
 			/* break up if statements for readability */
 			if ((flags & PROBE_TEST_FUNC) && entry->ops != ops)
@@ -3970,37 +3992,51 @@ static void ftrace_init_module(struct module *mod,
 	ftrace_process_locs(mod, start, end);
 }
 
-static int ftrace_module_notify(struct notifier_block *self,
-				unsigned long val, void *data)
+static int ftrace_module_notify_enter(struct notifier_block *self,
+				      unsigned long val, void *data)
 {
 	struct module *mod = data;
 
-	switch (val) {
-	case MODULE_STATE_COMING:
+	if (val == MODULE_STATE_COMING)
 		ftrace_init_module(mod, mod->ftrace_callsites,
 				   mod->ftrace_callsites +
 				   mod->num_ftrace_callsites);
-		break;
-	case MODULE_STATE_GOING:
+	return 0;
+}
+
+static int ftrace_module_notify_exit(struct notifier_block *self,
+				     unsigned long val, void *data)
+{
+	struct module *mod = data;
+
+	if (val == MODULE_STATE_GOING)
 		ftrace_release_mod(mod);
-		break;
-	}
 
 	return 0;
 }
 #else
-static int ftrace_module_notify(struct notifier_block *self,
-				unsigned long val, void *data)
+static int ftrace_module_notify_enter(struct notifier_block *self,
+				      unsigned long val, void *data)
+{
+	return 0;
+}
+static int ftrace_module_notify_exit(struct notifier_block *self,
+				     unsigned long val, void *data)
 {
 	return 0;
 }
 #endif /* CONFIG_MODULES */
 
-struct notifier_block ftrace_module_nb = {
-	.notifier_call = ftrace_module_notify,
+struct notifier_block ftrace_module_enter_nb = {
+	.notifier_call = ftrace_module_notify_enter,
 	.priority = INT_MAX,	/* Run before anything that can use kprobes */
 };
 
+struct notifier_block ftrace_module_exit_nb = {
+	.notifier_call = ftrace_module_notify_exit,
+	.priority = INT_MIN,	/* Run after anything that can remove kprobes */
+};
+
 extern unsigned long __start_mcount_loc[];
 extern unsigned long __stop_mcount_loc[];
 
@@ -4032,9 +4068,13 @@ void __init ftrace_init(void)
 				  __start_mcount_loc,
 				  __stop_mcount_loc);
 
-	ret = register_module_notifier(&ftrace_module_nb);
+	ret = register_module_notifier(&ftrace_module_enter_nb);
 	if (ret)
-		pr_warning("Failed to register trace ftrace module notifier\n");
+		pr_warning("Failed to register trace ftrace module enter notifier\n");
+
+	ret = register_module_notifier(&ftrace_module_exit_nb);
+	if (ret)
+		pr_warning("Failed to register trace ftrace module exit notifier\n");
 
 	set_ftrace_early_filters();
 
@@ -4090,14 +4130,11 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
 	 */
 	preempt_disable_notrace();
 	trace_recursion_set(TRACE_CONTROL_BIT);
-	op = rcu_dereference_raw(ftrace_control_list);
-	while (op != &ftrace_list_end) {
+	do_for_each_ftrace_op(op, ftrace_control_list) {
 		if (!ftrace_function_local_disabled(op) &&
 		    ftrace_ops_test(op, ip))
 			op->func(ip, parent_ip, op, regs);
-
-		op = rcu_dereference_raw(op->next);
-	};
+	} while_for_each_ftrace_op(op);
 	trace_recursion_clear(TRACE_CONTROL_BIT);
 	preempt_enable_notrace();
 }
@@ -4112,27 +4149,26 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
 		       struct ftrace_ops *ignored, struct pt_regs *regs)
 {
 	struct ftrace_ops *op;
+	int bit;
 
 	if (function_trace_stop)
 		return;
 
-	if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
+	bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
+	if (bit < 0)
 		return;
 
-	trace_recursion_set(TRACE_INTERNAL_BIT);
 	/*
 	 * Some of the ops may be dynamically allocated,
 	 * they must be freed after a synchronize_sched().
 	 */
 	preempt_disable_notrace();
-	op = rcu_dereference_raw(ftrace_ops_list);
-	while (op != &ftrace_list_end) {
+	do_for_each_ftrace_op(op, ftrace_ops_list) {
 		if (ftrace_ops_test(op, ip))
 			op->func(ip, parent_ip, op, regs);
-		op = rcu_dereference_raw(op->next);
-	};
+	} while_for_each_ftrace_op(op);
 	preempt_enable_notrace();
-	trace_recursion_clear(TRACE_INTERNAL_BIT);
+	trace_clear_recursion(bit);
 }
 
 /*
@@ -4143,8 +4179,8 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
  * Archs are to support both the regs and ftrace_ops at the same time.
  * If they support ftrace_ops, it is assumed they support regs.
  * If call backs want to use regs, they must either check for regs
- * being NULL, or ARCH_SUPPORTS_FTRACE_SAVE_REGS.
- * Note, ARCH_SUPPORT_SAVE_REGS expects a full regs to be saved.
+ * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
+ * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
  * An architecture can pass partial regs with ftrace_ops and still
  * set the ARCH_SUPPORT_FTARCE_OPS.
  */
diff --git a/kernel/trace/power-traces.c b/kernel/trace/power-traces.c
index f55fcf61b223..1c71382b283d 100644
--- a/kernel/trace/power-traces.c
+++ b/kernel/trace/power-traces.c
@@ -13,8 +13,5 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/power.h>
 
-#ifdef EVENT_POWER_TRACING_DEPRECATED
-EXPORT_TRACEPOINT_SYMBOL_GPL(power_start);
-#endif
 EXPORT_TRACEPOINT_SYMBOL_GPL(cpu_idle);
 
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index ce8514feedcd..6989df2ba194 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3,8 +3,10 @@
  *
  * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
  */
+#include <linux/ftrace_event.h>
 #include <linux/ring_buffer.h>
 #include <linux/trace_clock.h>
+#include <linux/trace_seq.h>
 #include <linux/spinlock.h>
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
@@ -21,7 +23,6 @@
 #include <linux/fs.h>
 
 #include <asm/local.h>
-#include "trace.h"
 
 static void update_pages_handler(struct work_struct *work);
 
@@ -177,7 +178,7 @@ void tracing_off_permanent(void)
 #define RB_MAX_SMALL_DATA	(RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX)
 #define RB_EVNT_MIN_SIZE	8U	/* two 32bit words */
 
-#if !defined(CONFIG_64BIT) || defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+#ifndef CONFIG_HAVE_64BIT_ALIGNED_ACCESS
 # define RB_FORCE_8BYTE_ALIGNMENT	0
 # define RB_ARCH_ALIGNMENT		RB_ALIGNMENT
 #else
@@ -185,6 +186,8 @@ void tracing_off_permanent(void)
 # define RB_ARCH_ALIGNMENT		8U
 #endif
 
+#define RB_ALIGN_DATA		__aligned(RB_ARCH_ALIGNMENT)
+
 /* define RINGBUF_TYPE_DATA for 'case RINGBUF_TYPE_DATA:' */
 #define RINGBUF_TYPE_DATA 0 ... RINGBUF_TYPE_DATA_TYPE_LEN_MAX
 
@@ -333,7 +336,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data);
 struct buffer_data_page {
 	u64		 time_stamp;	/* page time stamp */
 	local_t		 commit;	/* write committed index */
-	unsigned char	 data[];	/* data of buffer page */
+	unsigned char	 data[] RB_ALIGN_DATA;	/* data of buffer page */
 };
 
 /*
@@ -2432,41 +2435,76 @@ rb_reserve_next_event(struct ring_buffer *buffer,
 
 #ifdef CONFIG_TRACING
 
-#define TRACE_RECURSIVE_DEPTH 16
+/*
+ * The lock and unlock are done within a preempt disable section.
+ * The current_context per_cpu variable can only be modified
+ * by the current task between lock and unlock. But it can
+ * be modified more than once via an interrupt. To pass this
+ * information from the lock to the unlock without having to
+ * access the 'in_interrupt()' functions again (which do show
+ * a bit of overhead in something as critical as function tracing,
+ * we use a bitmask trick.
+ *
+ *  bit 0 =  NMI context
+ *  bit 1 =  IRQ context
+ *  bit 2 =  SoftIRQ context
+ *  bit 3 =  normal context.
+ *
+ * This works because this is the order of contexts that can
+ * preempt other contexts. A SoftIRQ never preempts an IRQ
+ * context.
+ *
+ * When the context is determined, the corresponding bit is
+ * checked and set (if it was set, then a recursion of that context
+ * happened).
+ *
+ * On unlock, we need to clear this bit. To do so, just subtract
+ * 1 from the current_context and AND it to itself.
+ *
+ * (binary)
+ *  101 - 1 = 100
+ *  101 & 100 = 100 (clearing bit zero)
+ *
+ *  1010 - 1 = 1001
+ *  1010 & 1001 = 1000 (clearing bit 1)
+ *
+ * The least significant bit can be cleared this way, and it
+ * just so happens that it is the same bit corresponding to
+ * the current context.
+ */
+static DEFINE_PER_CPU(unsigned int, current_context);
 
-/* Keep this code out of the fast path cache */
-static noinline void trace_recursive_fail(void)
+static __always_inline int trace_recursive_lock(void)
 {
-	/* Disable all tracing before we do anything else */
-	tracing_off_permanent();
-
-	printk_once(KERN_WARNING "Tracing recursion: depth[%ld]:"
-		    "HC[%lu]:SC[%lu]:NMI[%lu]\n",
-		    trace_recursion_buffer(),
-		    hardirq_count() >> HARDIRQ_SHIFT,
-		    softirq_count() >> SOFTIRQ_SHIFT,
-		    in_nmi());
-
-	WARN_ON_ONCE(1);
-}
+	unsigned int val = this_cpu_read(current_context);
+	int bit;
 
-static inline int trace_recursive_lock(void)
-{
-	trace_recursion_inc();
+	if (in_interrupt()) {
+		if (in_nmi())
+			bit = 0;
+		else if (in_irq())
+			bit = 1;
+		else
+			bit = 2;
+	} else
+		bit = 3;
 
-	if (likely(trace_recursion_buffer() < TRACE_RECURSIVE_DEPTH))
-		return 0;
+	if (unlikely(val & (1 << bit)))
+		return 1;
 
-	trace_recursive_fail();
+	val |= (1 << bit);
+	this_cpu_write(current_context, val);
 
-	return -1;
+	return 0;
 }
 
-static inline void trace_recursive_unlock(void)
+static __always_inline void trace_recursive_unlock(void)
 {
-	WARN_ON_ONCE(!trace_recursion_buffer());
+	unsigned int val = this_cpu_read(current_context);
 
-	trace_recursion_dec();
+	val--;
+	val &= this_cpu_read(current_context);
+	this_cpu_write(current_context, val);
 }
 
 #else
@@ -3067,6 +3105,24 @@ ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu)
 EXPORT_SYMBOL_GPL(ring_buffer_dropped_events_cpu);
 
 /**
+ * ring_buffer_read_events_cpu - get the number of events successfully read
+ * @buffer: The ring buffer
+ * @cpu: The per CPU buffer to get the number of events read
+ */
+unsigned long
+ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+
+	if (!cpumask_test_cpu(cpu, buffer->cpumask))
+		return 0;
+
+	cpu_buffer = buffer->buffers[cpu];
+	return cpu_buffer->read;
+}
+EXPORT_SYMBOL_GPL(ring_buffer_read_events_cpu);
+
+/**
  * ring_buffer_entries - get the number of entries in a buffer
  * @buffer: The ring buffer
  *
@@ -3425,7 +3481,7 @@ static void rb_advance_iter(struct ring_buffer_iter *iter)
 	/* check for end of page padding */
 	if ((iter->head >= rb_page_size(iter->head_page)) &&
 	    (iter->head_page != cpu_buffer->commit_page))
-		rb_advance_iter(iter);
+		rb_inc_iter(iter);
 }
 
 static int rb_lost_events(struct ring_buffer_per_cpu *cpu_buffer)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 3c13e46d7d24..1f835a83cb2c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -39,6 +39,7 @@
 #include <linux/poll.h>
 #include <linux/nmi.h>
 #include <linux/fs.h>
+#include <linux/sched/rt.h>
 
 #include "trace.h"
 #include "trace_output.h"
@@ -249,7 +250,7 @@ static unsigned long		trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
 static struct tracer		*trace_types __read_mostly;
 
 /* current_trace points to the tracer that is currently active */
-static struct tracer		*current_trace __read_mostly;
+static struct tracer		*current_trace __read_mostly = &nop_trace;
 
 /*
  * trace_types_lock is used to protect the trace_types list.
@@ -709,10 +710,13 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 		return;
 
 	WARN_ON_ONCE(!irqs_disabled());
-	if (!current_trace->use_max_tr) {
-		WARN_ON_ONCE(1);
+
+	if (!current_trace->allocated_snapshot) {
+		/* Only the nop tracer should hit this when disabling */
+		WARN_ON_ONCE(current_trace != &nop_trace);
 		return;
 	}
+
 	arch_spin_lock(&ftrace_max_lock);
 
 	tr->buffer = max_tr.buffer;
@@ -739,10 +743,8 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
 		return;
 
 	WARN_ON_ONCE(!irqs_disabled());
-	if (!current_trace->use_max_tr) {
-		WARN_ON_ONCE(1);
+	if (WARN_ON_ONCE(!current_trace->allocated_snapshot))
 		return;
-	}
 
 	arch_spin_lock(&ftrace_max_lock);
 
@@ -862,10 +864,13 @@ int register_tracer(struct tracer *type)
 
 		current_trace = type;
 
-		/* If we expanded the buffers, make sure the max is expanded too */
-		if (ring_buffer_expanded && type->use_max_tr)
-			ring_buffer_resize(max_tr.buffer, trace_buf_size,
-						RING_BUFFER_ALL_CPUS);
+		if (type->use_max_tr) {
+			/* If we expanded the buffers, make sure the max is expanded too */
+			if (ring_buffer_expanded)
+				ring_buffer_resize(max_tr.buffer, trace_buf_size,
+						   RING_BUFFER_ALL_CPUS);
+			type->allocated_snapshot = true;
+		}
 
 		/* the test is responsible for initializing and enabling */
 		pr_info("Testing tracer %s: ", type->name);
@@ -881,10 +886,14 @@ int register_tracer(struct tracer *type)
 		/* Only reset on passing, to avoid touching corrupted buffers */
 		tracing_reset_online_cpus(tr);
 
-		/* Shrink the max buffer again */
-		if (ring_buffer_expanded && type->use_max_tr)
-			ring_buffer_resize(max_tr.buffer, 1,
-						RING_BUFFER_ALL_CPUS);
+		if (type->use_max_tr) {
+			type->allocated_snapshot = false;
+
+			/* Shrink the max buffer again */
+			if (ring_buffer_expanded)
+				ring_buffer_resize(max_tr.buffer, 1,
+						   RING_BUFFER_ALL_CPUS);
+		}
 
 		printk(KERN_CONT "PASSED\n");
 	}
@@ -922,6 +931,9 @@ void tracing_reset(struct trace_array *tr, int cpu)
 {
 	struct ring_buffer *buffer = tr->buffer;
 
+	if (!buffer)
+		return;
+
 	ring_buffer_record_disable(buffer);
 
 	/* Make sure all commits have finished */
@@ -936,6 +948,9 @@ void tracing_reset_online_cpus(struct trace_array *tr)
 	struct ring_buffer *buffer = tr->buffer;
 	int cpu;
 
+	if (!buffer)
+		return;
+
 	ring_buffer_record_disable(buffer);
 
 	/* Make sure all commits have finished */
@@ -1167,7 +1182,6 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
 
 	entry->preempt_count		= pc & 0xff;
 	entry->pid			= (tsk) ? tsk->pid : 0;
-	entry->padding			= 0;
 	entry->flags =
 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
 		(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
@@ -1335,7 +1349,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer,
 	 */
 	preempt_disable_notrace();
 
-	use_stack = ++__get_cpu_var(ftrace_stack_reserve);
+	use_stack = __this_cpu_inc_return(ftrace_stack_reserve);
 	/*
 	 * We don't need any atomic variables, just a barrier.
 	 * If an interrupt comes in, we don't care, because it would
@@ -1389,7 +1403,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer,
  out:
 	/* Again, don't let gcc optimize things here */
 	barrier();
-	__get_cpu_var(ftrace_stack_reserve)--;
+	__this_cpu_dec(ftrace_stack_reserve);
 	preempt_enable_notrace();
 
 }
@@ -1517,7 +1531,6 @@ static struct trace_buffer_struct *trace_percpu_nmi_buffer;
 static char *get_trace_buf(void)
 {
 	struct trace_buffer_struct *percpu_buffer;
-	struct trace_buffer_struct *buffer;
 
 	/*
 	 * If we have allocated per cpu buffers, then we do not
@@ -1535,9 +1548,7 @@ static char *get_trace_buf(void)
 	if (!percpu_buffer)
 		return NULL;
 
-	buffer = per_cpu_ptr(percpu_buffer, smp_processor_id());
-
-	return buffer->buffer;
+	return this_cpu_ptr(&percpu_buffer->buffer[0]);
 }
 
 static int alloc_percpu_trace_buffer(void)
@@ -1942,21 +1953,27 @@ void tracing_iter_reset(struct trace_iterator *iter, int cpu)
 static void *s_start(struct seq_file *m, loff_t *pos)
 {
 	struct trace_iterator *iter = m->private;
-	static struct tracer *old_tracer;
 	int cpu_file = iter->cpu_file;
 	void *p = NULL;
 	loff_t l = 0;
 	int cpu;
 
-	/* copy the tracer to avoid using a global lock all around */
+	/*
+	 * copy the tracer to avoid using a global lock all around.
+	 * iter->trace is a copy of current_trace, the pointer to the
+	 * name may be used instead of a strcmp(), as iter->trace->name
+	 * will point to the same string as current_trace->name.
+	 */
 	mutex_lock(&trace_types_lock);
-	if (unlikely(old_tracer != current_trace && current_trace)) {
-		old_tracer = current_trace;
+	if (unlikely(current_trace && iter->trace->name != current_trace->name))
 		*iter->trace = *current_trace;
-	}
 	mutex_unlock(&trace_types_lock);
 
-	atomic_inc(&trace_record_cmdline_disabled);
+	if (iter->snapshot && iter->trace->use_max_tr)
+		return ERR_PTR(-EBUSY);
+
+	if (!iter->snapshot)
+		atomic_inc(&trace_record_cmdline_disabled);
 
 	if (*pos != iter->pos) {
 		iter->ent = NULL;
@@ -1995,7 +2012,11 @@ static void s_stop(struct seq_file *m, void *p)
 {
 	struct trace_iterator *iter = m->private;
 
-	atomic_dec(&trace_record_cmdline_disabled);
+	if (iter->snapshot && iter->trace->use_max_tr)
+		return;
+
+	if (!iter->snapshot)
+		atomic_dec(&trace_record_cmdline_disabled);
 	trace_access_unlock(iter->cpu_file);
 	trace_event_read_unlock();
 }
@@ -2080,8 +2101,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
 	unsigned long total;
 	const char *name = "preemption";
 
-	if (type)
-		name = type->name;
+	name = type->name;
 
 	get_total_entries(tr, &total, &entries);
 
@@ -2380,6 +2400,27 @@ static void test_ftrace_alive(struct seq_file *m)
 	seq_printf(m, "#          MAY BE MISSING FUNCTION EVENTS\n");
 }
 
+#ifdef CONFIG_TRACER_MAX_TRACE
+static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter)
+{
+	if (iter->trace->allocated_snapshot)
+		seq_printf(m, "#\n# * Snapshot is allocated *\n#\n");
+	else
+		seq_printf(m, "#\n# * Snapshot is freed *\n#\n");
+
+	seq_printf(m, "# Snapshot commands:\n");
+	seq_printf(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n");
+	seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n");
+	seq_printf(m, "#                      Takes a snapshot of the main buffer.\n");
+	seq_printf(m, "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate)\n");
+	seq_printf(m, "#                      (Doesn't have to be '2' works with any number that\n");
+	seq_printf(m, "#                       is not a '0' or '1')\n");
+}
+#else
+/* Should never be called */
+static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { }
+#endif
+
 static int s_show(struct seq_file *m, void *v)
 {
 	struct trace_iterator *iter = v;
@@ -2391,7 +2432,9 @@ static int s_show(struct seq_file *m, void *v)
 			seq_puts(m, "#\n");
 			test_ftrace_alive(m);
 		}
-		if (iter->trace && iter->trace->print_header)
+		if (iter->snapshot && trace_empty(iter))
+			print_snapshot_help(m, iter);
+		else if (iter->trace && iter->trace->print_header)
 			iter->trace->print_header(m);
 		else
 			trace_default_header(m);
@@ -2430,7 +2473,7 @@ static const struct seq_operations tracer_seq_ops = {
 };
 
 static struct trace_iterator *
-__tracing_open(struct inode *inode, struct file *file)
+__tracing_open(struct inode *inode, struct file *file, bool snapshot)
 {
 	long cpu_file = (long) inode->i_private;
 	struct trace_iterator *iter;
@@ -2457,16 +2500,16 @@ __tracing_open(struct inode *inode, struct file *file)
 	if (!iter->trace)
 		goto fail;
 
-	if (current_trace)
-		*iter->trace = *current_trace;
+	*iter->trace = *current_trace;
 
 	if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL))
 		goto fail;
 
-	if (current_trace && current_trace->print_max)
+	if (current_trace->print_max || snapshot)
 		iter->tr = &max_tr;
 	else
 		iter->tr = &global_trace;
+	iter->snapshot = snapshot;
 	iter->pos = -1;
 	mutex_init(&iter->mutex);
 	iter->cpu_file = cpu_file;
@@ -2483,8 +2526,9 @@ __tracing_open(struct inode *inode, struct file *file)
 	if (trace_clocks[trace_clock_id].in_ns)
 		iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
 
-	/* stop the trace while dumping */
-	tracing_stop();
+	/* stop the trace while dumping if we are not opening "snapshot" */
+	if (!iter->snapshot)
+		tracing_stop();
 
 	if (iter->cpu_file == TRACE_PIPE_ALL_CPU) {
 		for_each_tracing_cpu(cpu) {
@@ -2547,8 +2591,9 @@ static int tracing_release(struct inode *inode, struct file *file)
 	if (iter->trace && iter->trace->close)
 		iter->trace->close(iter);
 
-	/* reenable tracing if it was previously enabled */
-	tracing_start();
+	if (!iter->snapshot)
+		/* reenable tracing if it was previously enabled */
+		tracing_start();
 	mutex_unlock(&trace_types_lock);
 
 	mutex_destroy(&iter->mutex);
@@ -2576,7 +2621,7 @@ static int tracing_open(struct inode *inode, struct file *file)
 	}
 
 	if (file->f_mode & FMODE_READ) {
-		iter = __tracing_open(inode, file);
+		iter = __tracing_open(inode, file, false);
 		if (IS_ERR(iter))
 			ret = PTR_ERR(iter);
 		else if (trace_flags & TRACE_ITER_LATENCY_FMT)
@@ -3014,10 +3059,7 @@ tracing_set_trace_read(struct file *filp, char __user *ubuf,
 	int r;
 
 	mutex_lock(&trace_types_lock);
-	if (current_trace)
-		r = sprintf(buf, "%s\n", current_trace->name);
-	else
-		r = sprintf(buf, "\n");
+	r = sprintf(buf, "%s\n", current_trace->name);
 	mutex_unlock(&trace_types_lock);
 
 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
@@ -3183,6 +3225,7 @@ static int tracing_set_tracer(const char *buf)
 	static struct trace_option_dentry *topts;
 	struct trace_array *tr = &global_trace;
 	struct tracer *t;
+	bool had_max_tr;
 	int ret = 0;
 
 	mutex_lock(&trace_types_lock);
@@ -3207,9 +3250,21 @@ static int tracing_set_tracer(const char *buf)
 		goto out;
 
 	trace_branch_disable();
-	if (current_trace && current_trace->reset)
+	if (current_trace->reset)
 		current_trace->reset(tr);
-	if (current_trace && current_trace->use_max_tr) {
+
+	had_max_tr = current_trace->allocated_snapshot;
+	current_trace = &nop_trace;
+
+	if (had_max_tr && !t->use_max_tr) {
+		/*
+		 * We need to make sure that the update_max_tr sees that
+		 * current_trace changed to nop_trace to keep it from
+		 * swapping the buffers after we resize it.
+		 * The update_max_tr is called from interrupts disabled
+		 * so a synchronized_sched() is sufficient.
+		 */
+		synchronize_sched();
 		/*
 		 * We don't free the ring buffer. instead, resize it because
 		 * The max_tr ring buffer has some state (e.g. ring->clock) and
@@ -3217,18 +3272,19 @@ static int tracing_set_tracer(const char *buf)
 		 */
 		ring_buffer_resize(max_tr.buffer, 1, RING_BUFFER_ALL_CPUS);
 		set_buffer_entries(&max_tr, 1);
+		tracing_reset_online_cpus(&max_tr);
+		current_trace->allocated_snapshot = false;
 	}
 	destroy_trace_option_files(topts);
 
-	current_trace = &nop_trace;
-
 	topts = create_trace_option_files(t);
-	if (t->use_max_tr) {
+	if (t->use_max_tr && !had_max_tr) {
 		/* we need to make per cpu buffer sizes equivalent */
 		ret = resize_buffer_duplicate_size(&max_tr, &global_trace,
 						   RING_BUFFER_ALL_CPUS);
 		if (ret < 0)
 			goto out;
+		t->allocated_snapshot = true;
 	}
 
 	if (t->init) {
@@ -3336,8 +3392,7 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
 		ret = -ENOMEM;
 		goto fail;
 	}
-	if (current_trace)
-		*iter->trace = *current_trace;
+	*iter->trace = *current_trace;
 
 	if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
 		ret = -ENOMEM;
@@ -3477,7 +3532,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 		  size_t cnt, loff_t *ppos)
 {
 	struct trace_iterator *iter = filp->private_data;
-	static struct tracer *old_tracer;
 	ssize_t sret;
 
 	/* return any leftover data */
@@ -3489,10 +3543,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 
 	/* copy the tracer to avoid using a global lock all around */
 	mutex_lock(&trace_types_lock);
-	if (unlikely(old_tracer != current_trace && current_trace)) {
-		old_tracer = current_trace;
+	if (unlikely(iter->trace->name != current_trace->name))
 		*iter->trace = *current_trace;
-	}
 	mutex_unlock(&trace_types_lock);
 
 	/*
@@ -3648,7 +3700,6 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
 		.ops		= &tracing_pipe_buf_ops,
 		.spd_release	= tracing_spd_release_pipe,
 	};
-	static struct tracer *old_tracer;
 	ssize_t ret;
 	size_t rem;
 	unsigned int i;
@@ -3658,10 +3709,8 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,
 
 	/* copy the tracer to avoid using a global lock all around */
 	mutex_lock(&trace_types_lock);
-	if (unlikely(old_tracer != current_trace && current_trace)) {
-		old_tracer = current_trace;
+	if (unlikely(iter->trace->name != current_trace->name))
 		*iter->trace = *current_trace;
-	}
 	mutex_unlock(&trace_types_lock);
 
 	mutex_lock(&iter->mutex);
@@ -4037,8 +4086,7 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
 	 * Reset the buffer so that it doesn't have incomparable timestamps.
 	 */
 	tracing_reset_online_cpus(&global_trace);
-	if (max_tr.buffer)
-		tracing_reset_online_cpus(&max_tr);
+	tracing_reset_online_cpus(&max_tr);
 
 	mutex_unlock(&trace_types_lock);
 
@@ -4054,6 +4102,85 @@ static int tracing_clock_open(struct inode *inode, struct file *file)
 	return single_open(file, tracing_clock_show, NULL);
 }
 
+#ifdef CONFIG_TRACER_SNAPSHOT
+static int tracing_snapshot_open(struct inode *inode, struct file *file)
+{
+	struct trace_iterator *iter;
+	int ret = 0;
+
+	if (file->f_mode & FMODE_READ) {
+		iter = __tracing_open(inode, file, true);
+		if (IS_ERR(iter))
+			ret = PTR_ERR(iter);
+	}
+	return ret;
+}
+
+static ssize_t
+tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
+		       loff_t *ppos)
+{
+	unsigned long val;
+	int ret;
+
+	ret = tracing_update_buffers();
+	if (ret < 0)
+		return ret;
+
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
+		return ret;
+
+	mutex_lock(&trace_types_lock);
+
+	if (current_trace->use_max_tr) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	switch (val) {
+	case 0:
+		if (current_trace->allocated_snapshot) {
+			/* free spare buffer */
+			ring_buffer_resize(max_tr.buffer, 1,
+					   RING_BUFFER_ALL_CPUS);
+			set_buffer_entries(&max_tr, 1);
+			tracing_reset_online_cpus(&max_tr);
+			current_trace->allocated_snapshot = false;
+		}
+		break;
+	case 1:
+		if (!current_trace->allocated_snapshot) {
+			/* allocate spare buffer */
+			ret = resize_buffer_duplicate_size(&max_tr,
+					&global_trace, RING_BUFFER_ALL_CPUS);
+			if (ret < 0)
+				break;
+			current_trace->allocated_snapshot = true;
+		}
+
+		local_irq_disable();
+		/* Now, we're going to swap */
+		update_max_tr(&global_trace, current, smp_processor_id());
+		local_irq_enable();
+		break;
+	default:
+		if (current_trace->allocated_snapshot)
+			tracing_reset_online_cpus(&max_tr);
+		break;
+	}
+
+	if (ret >= 0) {
+		*ppos += cnt;
+		ret = cnt;
+	}
+out:
+	mutex_unlock(&trace_types_lock);
+	return ret;
+}
+#endif /* CONFIG_TRACER_SNAPSHOT */
+
+
 static const struct file_operations tracing_max_lat_fops = {
 	.open		= tracing_open_generic,
 	.read		= tracing_max_lat_read,
@@ -4110,6 +4237,16 @@ static const struct file_operations trace_clock_fops = {
 	.write		= tracing_clock_write,
 };
 
+#ifdef CONFIG_TRACER_SNAPSHOT
+static const struct file_operations snapshot_fops = {
+	.open		= tracing_snapshot_open,
+	.read		= seq_read,
+	.write		= tracing_snapshot_write,
+	.llseek		= tracing_seek,
+	.release	= tracing_release,
+};
+#endif /* CONFIG_TRACER_SNAPSHOT */
+
 struct ftrace_buffer_info {
 	struct trace_array	*tr;
 	void			*spare;
@@ -4414,6 +4551,9 @@ tracing_stats_read(struct file *filp, char __user *ubuf,
 	cnt = ring_buffer_dropped_events_cpu(tr->buffer, cpu);
 	trace_seq_printf(s, "dropped events: %ld\n", cnt);
 
+	cnt = ring_buffer_read_events_cpu(tr->buffer, cpu);
+	trace_seq_printf(s, "read events: %ld\n", cnt);
+
 	count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len);
 
 	kfree(s);
@@ -4490,7 +4630,7 @@ struct dentry *tracing_init_dentry(void)
 
 static struct dentry *d_percpu;
 
-struct dentry *tracing_dentry_percpu(void)
+static struct dentry *tracing_dentry_percpu(void)
 {
 	static int once;
 	struct dentry *d_tracer;
@@ -4906,6 +5046,11 @@ static __init int tracer_init_debugfs(void)
 			&ftrace_update_tot_cnt, &tracing_dyn_info_fops);
 #endif
 
+#ifdef CONFIG_TRACER_SNAPSHOT
+	trace_create_file("snapshot", 0644, d_tracer,
+			  (void *) TRACE_PIPE_ALL_CPU, &snapshot_fops);
+#endif
+
 	create_trace_options_dir();
 
 	for_each_tracing_cpu(cpu)
@@ -5014,6 +5159,7 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
 	if (disable_tracing)
 		ftrace_kill();
 
+	/* Simulate the iterator */
 	trace_init_global_iter(&iter);
 
 	for_each_tracing_cpu(cpu) {
@@ -5025,10 +5171,6 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
 	/* don't look at user memory in panic mode */
 	trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
 
-	/* Simulate the iterator */
-	iter.tr = &global_trace;
-	iter.trace = current_trace;
-
 	switch (oops_dump_mode) {
 	case DUMP_ALL:
 		iter.cpu_file = TRACE_PIPE_ALL_CPU;
@@ -5173,7 +5315,7 @@ __init static int tracer_alloc_buffers(void)
 	init_irq_work(&trace_work_wakeup, trace_wake_up);
 
 	register_tracer(&nop_trace);
-	current_trace = &nop_trace;
+
 	/* All seems OK, enable tracing */
 	tracing_disabled = 0;
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index c75d7988902c..57d7e5397d56 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -287,20 +287,62 @@ struct tracer {
 	struct tracer_flags	*flags;
 	bool			print_max;
 	bool			use_max_tr;
+	bool			allocated_snapshot;
 };
 
 
 /* Only current can touch trace_recursion */
-#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0)
-#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0)
 
-/* Ring buffer has the 10 LSB bits to count */
-#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff)
-
-/* for function tracing recursion */
-#define TRACE_INTERNAL_BIT		(1<<11)
-#define TRACE_GLOBAL_BIT		(1<<12)
-#define TRACE_CONTROL_BIT		(1<<13)
+/*
+ * For function tracing recursion:
+ *  The order of these bits are important.
+ *
+ *  When function tracing occurs, the following steps are made:
+ *   If arch does not support a ftrace feature:
+ *    call internal function (uses INTERNAL bits) which calls...
+ *   If callback is registered to the "global" list, the list
+ *    function is called and recursion checks the GLOBAL bits.
+ *    then this function calls...
+ *   The function callback, which can use the FTRACE bits to
+ *    check for recursion.
+ *
+ * Now if the arch does not suppport a feature, and it calls
+ * the global list function which calls the ftrace callback
+ * all three of these steps will do a recursion protection.
+ * There's no reason to do one if the previous caller already
+ * did. The recursion that we are protecting against will
+ * go through the same steps again.
+ *
+ * To prevent the multiple recursion checks, if a recursion
+ * bit is set that is higher than the MAX bit of the current
+ * check, then we know that the check was made by the previous
+ * caller, and we can skip the current check.
+ */
+enum {
+	TRACE_BUFFER_BIT,
+	TRACE_BUFFER_NMI_BIT,
+	TRACE_BUFFER_IRQ_BIT,
+	TRACE_BUFFER_SIRQ_BIT,
+
+	/* Start of function recursion bits */
+	TRACE_FTRACE_BIT,
+	TRACE_FTRACE_NMI_BIT,
+	TRACE_FTRACE_IRQ_BIT,
+	TRACE_FTRACE_SIRQ_BIT,
+
+	/* GLOBAL_BITs must be greater than FTRACE_BITs */
+	TRACE_GLOBAL_BIT,
+	TRACE_GLOBAL_NMI_BIT,
+	TRACE_GLOBAL_IRQ_BIT,
+	TRACE_GLOBAL_SIRQ_BIT,
+
+	/* INTERNAL_BITs must be greater than GLOBAL_BITs */
+	TRACE_INTERNAL_BIT,
+	TRACE_INTERNAL_NMI_BIT,
+	TRACE_INTERNAL_IRQ_BIT,
+	TRACE_INTERNAL_SIRQ_BIT,
+
+	TRACE_CONTROL_BIT,
 
 /*
  * Abuse of the trace_recursion.
@@ -309,11 +351,77 @@ struct tracer {
  * was called in irq context but we have irq tracing off. Since this
  * can only be modified by current, we can reuse trace_recursion.
  */
-#define TRACE_IRQ_BIT			(1<<13)
+	TRACE_IRQ_BIT,
+};
+
+#define trace_recursion_set(bit)	do { (current)->trace_recursion |= (1<<(bit)); } while (0)
+#define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
+#define trace_recursion_test(bit)	((current)->trace_recursion & (1<<(bit)))
+
+#define TRACE_CONTEXT_BITS	4
+
+#define TRACE_FTRACE_START	TRACE_FTRACE_BIT
+#define TRACE_FTRACE_MAX	((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
+
+#define TRACE_GLOBAL_START	TRACE_GLOBAL_BIT
+#define TRACE_GLOBAL_MAX	((1 << (TRACE_GLOBAL_START + TRACE_CONTEXT_BITS)) - 1)
+
+#define TRACE_LIST_START	TRACE_INTERNAL_BIT
+#define TRACE_LIST_MAX		((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
+
+#define TRACE_CONTEXT_MASK	TRACE_LIST_MAX
+
+static __always_inline int trace_get_context_bit(void)
+{
+	int bit;
 
-#define trace_recursion_set(bit)	do { (current)->trace_recursion |= (bit); } while (0)
-#define trace_recursion_clear(bit)	do { (current)->trace_recursion &= ~(bit); } while (0)
-#define trace_recursion_test(bit)	((current)->trace_recursion & (bit))
+	if (in_interrupt()) {
+		if (in_nmi())
+			bit = 0;
+
+		else if (in_irq())
+			bit = 1;
+		else
+			bit = 2;
+	} else
+		bit = 3;
+
+	return bit;
+}
+
+static __always_inline int trace_test_and_set_recursion(int start, int max)
+{
+	unsigned int val = current->trace_recursion;
+	int bit;
+
+	/* A previous recursion check was made */
+	if ((val & TRACE_CONTEXT_MASK) > max)
+		return 0;
+
+	bit = trace_get_context_bit() + start;
+	if (unlikely(val & (1 << bit)))
+		return -1;
+
+	val |= 1 << bit;
+	current->trace_recursion = val;
+	barrier();
+
+	return bit;
+}
+
+static __always_inline void trace_clear_recursion(int bit)
+{
+	unsigned int val = current->trace_recursion;
+
+	if (!bit)
+		return;
+
+	bit = 1 << bit;
+	val &= ~bit;
+
+	barrier();
+	current->trace_recursion = val;
+}
 
 #define TRACE_PIPE_ALL_CPU	-1
 
diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c
index 394783531cbb..aa8f5f48dae6 100644
--- a/kernel/trace/trace_clock.c
+++ b/kernel/trace/trace_clock.c
@@ -21,8 +21,6 @@
 #include <linux/ktime.h>
 #include <linux/trace_clock.h>
 
-#include "trace.h"
-
 /*
  * trace_clock_local(): the simplest and least coherent tracing clock.
  *
@@ -44,6 +42,7 @@ u64 notrace trace_clock_local(void)
 
 	return clock;
 }
+EXPORT_SYMBOL_GPL(trace_clock_local);
 
 /*
  * trace_clock(): 'between' trace clock. Not completely serialized,
@@ -86,7 +85,7 @@ u64 notrace trace_clock_global(void)
 	local_irq_save(flags);
 
 	this_cpu = raw_smp_processor_id();
-	now = cpu_clock(this_cpu);
+	now = sched_clock_cpu(this_cpu);
 	/*
 	 * If in an NMI context then dont risk lockups and return the
 	 * cpu_clock() time:
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 880073d0b946..57e9b284250c 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -116,7 +116,6 @@ static int trace_define_common_fields(void)
 	__common_field(unsigned char, flags);
 	__common_field(unsigned char, preempt_count);
 	__common_field(int, pid);
-	__common_field(int, padding);
 
 	return ret;
 }
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 8e3ad8082ab7..601152523326 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -47,34 +47,6 @@ static void function_trace_start(struct trace_array *tr)
 	tracing_reset_online_cpus(tr);
 }
 
-static void
-function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip,
-				 struct ftrace_ops *op, struct pt_regs *pt_regs)
-{
-	struct trace_array *tr = func_trace;
-	struct trace_array_cpu *data;
-	unsigned long flags;
-	long disabled;
-	int cpu;
-	int pc;
-
-	if (unlikely(!ftrace_function_enabled))
-		return;
-
-	pc = preempt_count();
-	preempt_disable_notrace();
-	local_save_flags(flags);
-	cpu = raw_smp_processor_id();
-	data = tr->data[cpu];
-	disabled = atomic_inc_return(&data->disabled);
-
-	if (likely(disabled == 1))
-		trace_function(tr, ip, parent_ip, flags, pc);
-
-	atomic_dec(&data->disabled);
-	preempt_enable_notrace();
-}
-
 /* Our option */
 enum {
 	TRACE_FUNC_OPT_STACK	= 0x1,
@@ -85,34 +57,34 @@ static struct tracer_flags func_flags;
 static void
 function_trace_call(unsigned long ip, unsigned long parent_ip,
 		    struct ftrace_ops *op, struct pt_regs *pt_regs)
-
 {
 	struct trace_array *tr = func_trace;
 	struct trace_array_cpu *data;
 	unsigned long flags;
-	long disabled;
+	int bit;
 	int cpu;
 	int pc;
 
 	if (unlikely(!ftrace_function_enabled))
 		return;
 
-	/*
-	 * Need to use raw, since this must be called before the
-	 * recursive protection is performed.
-	 */
-	local_irq_save(flags);
-	cpu = raw_smp_processor_id();
-	data = tr->data[cpu];
-	disabled = atomic_inc_return(&data->disabled);
+	pc = preempt_count();
+	preempt_disable_notrace();
 
-	if (likely(disabled == 1)) {
-		pc = preempt_count();
+	bit = trace_test_and_set_recursion(TRACE_FTRACE_START, TRACE_FTRACE_MAX);
+	if (bit < 0)
+		goto out;
+
+	cpu = smp_processor_id();
+	data = tr->data[cpu];
+	if (!atomic_read(&data->disabled)) {
+		local_save_flags(flags);
 		trace_function(tr, ip, parent_ip, flags, pc);
 	}
+	trace_clear_recursion(bit);
 
-	atomic_dec(&data->disabled);
-	local_irq_restore(flags);
+ out:
+	preempt_enable_notrace();
 }
 
 static void
@@ -185,11 +157,6 @@ static void tracing_start_function_trace(void)
 {
 	ftrace_function_enabled = 0;
 
-	if (trace_flags & TRACE_ITER_PREEMPTONLY)
-		trace_ops.func = function_trace_call_preempt_only;
-	else
-		trace_ops.func = function_trace_call;
-
 	if (func_flags.val & TRACE_FUNC_OPT_STACK)
 		register_ftrace_function(&trace_stack_ops);
 	else
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 4edb4b74eb7e..39ada66389cc 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -47,6 +47,8 @@ struct fgraph_data {
 #define TRACE_GRAPH_PRINT_ABS_TIME	0x20
 #define TRACE_GRAPH_PRINT_IRQS		0x40
 
+static unsigned int max_depth;
+
 static struct tracer_opt trace_opts[] = {
 	/* Display overruns? (for self-debug purpose) */
 	{ TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
@@ -189,10 +191,16 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
 
 	ftrace_pop_return_trace(&trace, &ret, frame_pointer);
 	trace.rettime = trace_clock_local();
-	ftrace_graph_return(&trace);
 	barrier();
 	current->curr_ret_stack--;
 
+	/*
+	 * The trace should run after decrementing the ret counter
+	 * in case an interrupt were to come in. We don't want to
+	 * lose the interrupt if max_depth is set.
+	 */
+	ftrace_graph_return(&trace);
+
 	if (unlikely(!ret)) {
 		ftrace_graph_stop();
 		WARN_ON(1);
@@ -250,8 +258,9 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
 		return 0;
 
 	/* trace it when it is-nested-in or is a function enabled. */
-	if (!(trace->depth || ftrace_graph_addr(trace->func)) ||
-	      ftrace_graph_ignore_irqs())
+	if ((!(trace->depth || ftrace_graph_addr(trace->func)) ||
+	     ftrace_graph_ignore_irqs()) ||
+	    (max_depth && trace->depth >= max_depth))
 		return 0;
 
 	local_irq_save(flags);
@@ -1457,6 +1466,59 @@ static struct tracer graph_trace __read_mostly = {
 #endif
 };
 
+
+static ssize_t
+graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt,
+		  loff_t *ppos)
+{
+	unsigned long val;
+	int ret;
+
+	ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
+	if (ret)
+		return ret;
+
+	max_depth = val;
+
+	*ppos += cnt;
+
+	return cnt;
+}
+
+static ssize_t
+graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt,
+		 loff_t *ppos)
+{
+	char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/
+	int n;
+
+	n = sprintf(buf, "%d\n", max_depth);
+
+	return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
+}
+
+static const struct file_operations graph_depth_fops = {
+	.open		= tracing_open_generic,
+	.write		= graph_depth_write,
+	.read		= graph_depth_read,
+	.llseek		= generic_file_llseek,
+};
+
+static __init int init_graph_debugfs(void)
+{
+	struct dentry *d_tracer;
+
+	d_tracer = tracing_init_dentry();
+	if (!d_tracer)
+		return 0;
+
+	trace_create_file("max_graph_depth", 0644, d_tracer,
+			  NULL, &graph_depth_fops);
+
+	return 0;
+}
+fs_initcall(init_graph_debugfs);
+
 static __init int init_graph_trace(void)
 {
 	max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 194d79602dc7..697e88d13907 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -739,12 +739,11 @@ static int task_state_char(unsigned long state)
 struct trace_event *ftrace_find_event(int type)
 {
 	struct trace_event *event;
-	struct hlist_node *n;
 	unsigned key;
 
 	key = type & (EVENT_HASHSIZE - 1);
 
-	hlist_for_each_entry(event, n, &event_hash[key], node) {
+	hlist_for_each_entry(event, &event_hash[key], node) {
 		if (event->type == type)
 			return event;
 	}
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 933708677814..5c7e09d10d74 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -66,7 +66,6 @@
 #define TP_FLAG_TRACE		1
 #define TP_FLAG_PROFILE		2
 #define TP_FLAG_REGISTERED	4
-#define TP_FLAG_UPROBE		8
 
 
 /* data_rloc: data relative location, compatible with u32 */
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 9fe45fcefca0..75aa97fbe1a1 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -15,8 +15,8 @@
 #include <linux/kallsyms.h>
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
+#include <linux/sched/rt.h>
 #include <trace/events/sched.h>
-
 #include "trace.h"
 
 static struct trace_array	*wakeup_trace;
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 47623169a815..51c819c12c29 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -415,7 +415,8 @@ static void trace_selftest_test_recursion_func(unsigned long ip,
 	 * The ftrace infrastructure should provide the recursion
 	 * protection. If not, this will crash the kernel!
 	 */
-	trace_selftest_recursion_cnt++;
+	if (trace_selftest_recursion_cnt++ > 10)
+		return;
 	DYN_FTRACE_TEST_NAME();
 }
 
@@ -452,7 +453,6 @@ trace_selftest_function_recursion(void)
 	char *func_name;
 	int len;
 	int ret;
-	int cnt;
 
 	/* The previous test PASSED */
 	pr_cont("PASSED\n");
@@ -510,19 +510,10 @@ trace_selftest_function_recursion(void)
 
 	unregister_ftrace_function(&test_recsafe_probe);
 
-	/*
-	 * If arch supports all ftrace features, and no other task
-	 * was on the list, we should be fine.
-	 */
-	if (!ftrace_nr_registered_ops() && !FTRACE_FORCE_LIST_FUNC)
-		cnt = 2; /* Should have recursed */
-	else
-		cnt = 1;
-
 	ret = -1;
-	if (trace_selftest_recursion_cnt != cnt) {
-		pr_cont("*callback not called expected %d times (%d)* ",
-			cnt, trace_selftest_recursion_cnt);
+	if (trace_selftest_recursion_cnt != 2) {
+		pr_cont("*callback not called expected 2 times (%d)* ",
+			trace_selftest_recursion_cnt);
 		goto out;
 	}
 
@@ -568,7 +559,7 @@ trace_selftest_function_regs(void)
 	int ret;
 	int supported = 0;
 
-#ifdef ARCH_SUPPORTS_FTRACE_SAVE_REGS
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	supported = 1;
 #endif
 
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 7609dd6714c2..7a809e321058 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -1,5 +1,6 @@
 #include <trace/syscall.h>
 #include <trace/events/syscalls.h>
+#include <linux/syscalls.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/module.h>	/* for MODULE_NAME_LEN via KSYM_SYMBOL_LEN */
@@ -47,6 +48,38 @@ static inline bool arch_syscall_match_sym_name(const char *sym, const char *name
 }
 #endif
 
+#ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS
+/*
+ * Some architectures that allow for 32bit applications
+ * to run on a 64bit kernel, do not map the syscalls for
+ * the 32bit tasks the same as they do for 64bit tasks.
+ *
+ *     *cough*x86*cough*
+ *
+ * In such a case, instead of reporting the wrong syscalls,
+ * simply ignore them.
+ *
+ * For an arch to ignore the compat syscalls it needs to
+ * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as
+ * define the function arch_trace_is_compat_syscall() to let
+ * the tracing system know that it should ignore it.
+ */
+static int
+trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs)
+{
+	if (unlikely(arch_trace_is_compat_syscall(regs)))
+		return -1;
+
+	return syscall_get_nr(task, regs);
+}
+#else
+static inline int
+trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs)
+{
+	return syscall_get_nr(task, regs);
+}
+#endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */
+
 static __init struct syscall_metadata *
 find_syscall_meta(unsigned long syscall)
 {
@@ -77,7 +110,7 @@ static struct syscall_metadata *syscall_nr_to_meta(int nr)
 	return syscalls_metadata[nr];
 }
 
-enum print_line_t
+static enum print_line_t
 print_syscall_enter(struct trace_iterator *iter, int flags,
 		    struct trace_event *event)
 {
@@ -130,7 +163,7 @@ end:
 	return TRACE_TYPE_HANDLED;
 }
 
-enum print_line_t
+static enum print_line_t
 print_syscall_exit(struct trace_iterator *iter, int flags,
 		   struct trace_event *event)
 {
@@ -270,16 +303,16 @@ static int syscall_exit_define_fields(struct ftrace_event_call *call)
 	return ret;
 }
 
-void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id)
+static void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id)
 {
 	struct syscall_trace_enter *entry;
 	struct syscall_metadata *sys_data;
 	struct ring_buffer_event *event;
 	struct ring_buffer *buffer;
-	int size;
 	int syscall_nr;
+	int size;
 
-	syscall_nr = syscall_get_nr(current, regs);
+	syscall_nr = trace_get_syscall_nr(current, regs);
 	if (syscall_nr < 0)
 		return;
 	if (!test_bit(syscall_nr, enabled_enter_syscalls))
@@ -305,7 +338,7 @@ void ftrace_syscall_enter(void *ignore, struct pt_regs *regs, long id)
 		trace_current_buffer_unlock_commit(buffer, event, 0, 0);
 }
 
-void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
+static void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
 {
 	struct syscall_trace_exit *entry;
 	struct syscall_metadata *sys_data;
@@ -313,7 +346,7 @@ void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
 	struct ring_buffer *buffer;
 	int syscall_nr;
 
-	syscall_nr = syscall_get_nr(current, regs);
+	syscall_nr = trace_get_syscall_nr(current, regs);
 	if (syscall_nr < 0)
 		return;
 	if (!test_bit(syscall_nr, enabled_exit_syscalls))
@@ -337,7 +370,7 @@ void ftrace_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
 		trace_current_buffer_unlock_commit(buffer, event, 0, 0);
 }
 
-int reg_event_syscall_enter(struct ftrace_event_call *call)
+static int reg_event_syscall_enter(struct ftrace_event_call *call)
 {
 	int ret = 0;
 	int num;
@@ -356,7 +389,7 @@ int reg_event_syscall_enter(struct ftrace_event_call *call)
 	return ret;
 }
 
-void unreg_event_syscall_enter(struct ftrace_event_call *call)
+static void unreg_event_syscall_enter(struct ftrace_event_call *call)
 {
 	int num;
 
@@ -371,7 +404,7 @@ void unreg_event_syscall_enter(struct ftrace_event_call *call)
 	mutex_unlock(&syscall_trace_lock);
 }
 
-int reg_event_syscall_exit(struct ftrace_event_call *call)
+static int reg_event_syscall_exit(struct ftrace_event_call *call)
 {
 	int ret = 0;
 	int num;
@@ -390,7 +423,7 @@ int reg_event_syscall_exit(struct ftrace_event_call *call)
 	return ret;
 }
 
-void unreg_event_syscall_exit(struct ftrace_event_call *call)
+static void unreg_event_syscall_exit(struct ftrace_event_call *call)
 {
 	int num;
 
@@ -459,7 +492,7 @@ unsigned long __init __weak arch_syscall_addr(int nr)
 	return (unsigned long)sys_call_table[nr];
 }
 
-int __init init_ftrace_syscalls(void)
+static int __init init_ftrace_syscalls(void)
 {
 	struct syscall_metadata *meta;
 	unsigned long addr;
@@ -502,7 +535,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
 	int rctx;
 	int size;
 
-	syscall_nr = syscall_get_nr(current, regs);
+	syscall_nr = trace_get_syscall_nr(current, regs);
 	if (syscall_nr < 0)
 		return;
 	if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
@@ -578,7 +611,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
 	int rctx;
 	int size;
 
-	syscall_nr = syscall_get_nr(current, regs);
+	syscall_nr = trace_get_syscall_nr(current, regs);
 	if (syscall_nr < 0)
 		return;
 	if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index c86e6d4f67fb..8dad2a92dee9 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -28,20 +28,21 @@
 
 #define UPROBE_EVENT_SYSTEM	"uprobes"
 
+struct trace_uprobe_filter {
+	rwlock_t		rwlock;
+	int			nr_systemwide;
+	struct list_head	perf_events;
+};
+
 /*
  * uprobe event core functions
  */
-struct trace_uprobe;
-struct uprobe_trace_consumer {
-	struct uprobe_consumer		cons;
-	struct trace_uprobe		*tu;
-};
-
 struct trace_uprobe {
 	struct list_head		list;
 	struct ftrace_event_class	class;
 	struct ftrace_event_call	call;
-	struct uprobe_trace_consumer	*consumer;
+	struct trace_uprobe_filter	filter;
+	struct uprobe_consumer		consumer;
 	struct inode			*inode;
 	char				*filename;
 	unsigned long			offset;
@@ -64,6 +65,18 @@ static LIST_HEAD(uprobe_list);
 
 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
 
+static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
+{
+	rwlock_init(&filter->rwlock);
+	filter->nr_systemwide = 0;
+	INIT_LIST_HEAD(&filter->perf_events);
+}
+
+static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
+{
+	return !filter->nr_systemwide && list_empty(&filter->perf_events);
+}
+
 /*
  * Allocate new trace_uprobe and initialize it (including uprobes).
  */
@@ -92,6 +105,8 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs)
 		goto error;
 
 	INIT_LIST_HEAD(&tu->list);
+	tu->consumer.handler = uprobe_dispatcher;
+	init_trace_uprobe_filter(&tu->filter);
 	return tu;
 
 error:
@@ -253,12 +268,18 @@ static int create_trace_uprobe(int argc, char **argv)
 	if (ret)
 		goto fail_address_parse;
 
+	inode = igrab(path.dentry->d_inode);
+	path_put(&path);
+
+	if (!inode || !S_ISREG(inode->i_mode)) {
+		ret = -EINVAL;
+		goto fail_address_parse;
+	}
+
 	ret = kstrtoul(arg, 0, &offset);
 	if (ret)
 		goto fail_address_parse;
 
-	inode = igrab(path.dentry->d_inode);
-
 	argc -= 2;
 	argv += 2;
 
@@ -356,7 +377,7 @@ fail_address_parse:
 	if (inode)
 		iput(inode);
 
-	pr_info("Failed to parse address.\n");
+	pr_info("Failed to parse address or file.\n");
 
 	return ret;
 }
@@ -465,7 +486,7 @@ static const struct file_operations uprobe_profile_ops = {
 };
 
 /* uprobe handler */
-static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
+static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
 {
 	struct uprobe_trace_entry_head *entry;
 	struct ring_buffer_event *event;
@@ -475,8 +496,6 @@ static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
 	unsigned long irq_flags;
 	struct ftrace_event_call *call = &tu->call;
 
-	tu->nhit++;
-
 	local_save_flags(irq_flags);
 	pc = preempt_count();
 
@@ -485,16 +504,18 @@ static void uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
 	event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
 						  size, irq_flags, pc);
 	if (!event)
-		return;
+		return 0;
 
 	entry = ring_buffer_event_data(event);
-	entry->ip = uprobe_get_swbp_addr(task_pt_regs(current));
+	entry->ip = instruction_pointer(task_pt_regs(current));
 	data = (u8 *)&entry[1];
 	for (i = 0; i < tu->nr_args; i++)
 		call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
 
 	if (!filter_current_check_discard(buffer, call, entry, event))
 		trace_buffer_unlock_commit(buffer, event, irq_flags, pc);
+
+	return 0;
 }
 
 /* Event entry printers */
@@ -533,42 +554,43 @@ partial:
 	return TRACE_TYPE_PARTIAL_LINE;
 }
 
-static int probe_event_enable(struct trace_uprobe *tu, int flag)
+static inline bool is_trace_uprobe_enabled(struct trace_uprobe *tu)
 {
-	struct uprobe_trace_consumer *utc;
-	int ret = 0;
+	return tu->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE);
+}
 
-	if (!tu->inode || tu->consumer)
-		return -EINTR;
+typedef bool (*filter_func_t)(struct uprobe_consumer *self,
+				enum uprobe_filter_ctx ctx,
+				struct mm_struct *mm);
 
-	utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL);
-	if (!utc)
+static int
+probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter)
+{
+	int ret = 0;
+
+	if (is_trace_uprobe_enabled(tu))
 		return -EINTR;
 
-	utc->cons.handler = uprobe_dispatcher;
-	utc->cons.filter = NULL;
-	ret = uprobe_register(tu->inode, tu->offset, &utc->cons);
-	if (ret) {
-		kfree(utc);
-		return ret;
-	}
+	WARN_ON(!uprobe_filter_is_empty(&tu->filter));
 
 	tu->flags |= flag;
-	utc->tu = tu;
-	tu->consumer = utc;
+	tu->consumer.filter = filter;
+	ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
+	if (ret)
+		tu->flags &= ~flag;
 
-	return 0;
+	return ret;
 }
 
 static void probe_event_disable(struct trace_uprobe *tu, int flag)
 {
-	if (!tu->inode || !tu->consumer)
+	if (!is_trace_uprobe_enabled(tu))
 		return;
 
-	uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons);
+	WARN_ON(!uprobe_filter_is_empty(&tu->filter));
+
+	uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
 	tu->flags &= ~flag;
-	kfree(tu->consumer);
-	tu->consumer = NULL;
 }
 
 static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
@@ -642,8 +664,96 @@ static int set_print_fmt(struct trace_uprobe *tu)
 }
 
 #ifdef CONFIG_PERF_EVENTS
+static bool
+__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
+{
+	struct perf_event *event;
+
+	if (filter->nr_systemwide)
+		return true;
+
+	list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
+		if (event->hw.tp_target->mm == mm)
+			return true;
+	}
+
+	return false;
+}
+
+static inline bool
+uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
+{
+	return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm);
+}
+
+static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
+{
+	bool done;
+
+	write_lock(&tu->filter.rwlock);
+	if (event->hw.tp_target) {
+		/*
+		 * event->parent != NULL means copy_process(), we can avoid
+		 * uprobe_apply(). current->mm must be probed and we can rely
+		 * on dup_mmap() which preserves the already installed bp's.
+		 *
+		 * attr.enable_on_exec means that exec/mmap will install the
+		 * breakpoints we need.
+		 */
+		done = tu->filter.nr_systemwide ||
+			event->parent || event->attr.enable_on_exec ||
+			uprobe_filter_event(tu, event);
+		list_add(&event->hw.tp_list, &tu->filter.perf_events);
+	} else {
+		done = tu->filter.nr_systemwide;
+		tu->filter.nr_systemwide++;
+	}
+	write_unlock(&tu->filter.rwlock);
+
+	if (!done)
+		uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
+
+	return 0;
+}
+
+static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
+{
+	bool done;
+
+	write_lock(&tu->filter.rwlock);
+	if (event->hw.tp_target) {
+		list_del(&event->hw.tp_list);
+		done = tu->filter.nr_systemwide ||
+			(event->hw.tp_target->flags & PF_EXITING) ||
+			uprobe_filter_event(tu, event);
+	} else {
+		tu->filter.nr_systemwide--;
+		done = tu->filter.nr_systemwide;
+	}
+	write_unlock(&tu->filter.rwlock);
+
+	if (!done)
+		uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
+
+	return 0;
+}
+
+static bool uprobe_perf_filter(struct uprobe_consumer *uc,
+				enum uprobe_filter_ctx ctx, struct mm_struct *mm)
+{
+	struct trace_uprobe *tu;
+	int ret;
+
+	tu = container_of(uc, struct trace_uprobe, consumer);
+	read_lock(&tu->filter.rwlock);
+	ret = __uprobe_perf_filter(&tu->filter, mm);
+	read_unlock(&tu->filter.rwlock);
+
+	return ret;
+}
+
 /* uprobe profile handler */
-static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
+static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
 {
 	struct ftrace_event_call *call = &tu->call;
 	struct uprobe_trace_entry_head *entry;
@@ -652,11 +762,14 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
 	int size, __size, i;
 	int rctx;
 
+	if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
+		return UPROBE_HANDLER_REMOVE;
+
 	__size = sizeof(*entry) + tu->size;
 	size = ALIGN(__size + sizeof(u32), sizeof(u64));
 	size -= sizeof(u32);
 	if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
-		return;
+		return 0;
 
 	preempt_disable();
 
@@ -664,7 +777,7 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
 	if (!entry)
 		goto out;
 
-	entry->ip = uprobe_get_swbp_addr(task_pt_regs(current));
+	entry->ip = instruction_pointer(task_pt_regs(current));
 	data = (u8 *)&entry[1];
 	for (i = 0; i < tu->nr_args; i++)
 		call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
@@ -674,6 +787,7 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
 
  out:
 	preempt_enable();
+	return 0;
 }
 #endif	/* CONFIG_PERF_EVENTS */
 
@@ -684,7 +798,7 @@ int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type,
 
 	switch (type) {
 	case TRACE_REG_REGISTER:
-		return probe_event_enable(tu, TP_FLAG_TRACE);
+		return probe_event_enable(tu, TP_FLAG_TRACE, NULL);
 
 	case TRACE_REG_UNREGISTER:
 		probe_event_disable(tu, TP_FLAG_TRACE);
@@ -692,11 +806,18 @@ int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type,
 
 #ifdef CONFIG_PERF_EVENTS
 	case TRACE_REG_PERF_REGISTER:
-		return probe_event_enable(tu, TP_FLAG_PROFILE);
+		return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter);
 
 	case TRACE_REG_PERF_UNREGISTER:
 		probe_event_disable(tu, TP_FLAG_PROFILE);
 		return 0;
+
+	case TRACE_REG_PERF_OPEN:
+		return uprobe_perf_open(tu, data);
+
+	case TRACE_REG_PERF_CLOSE:
+		return uprobe_perf_close(tu, data);
+
 #endif
 	default:
 		return 0;
@@ -706,22 +827,20 @@ int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type,
 
 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
 {
-	struct uprobe_trace_consumer *utc;
 	struct trace_uprobe *tu;
+	int ret = 0;
 
-	utc = container_of(con, struct uprobe_trace_consumer, cons);
-	tu = utc->tu;
-	if (!tu || tu->consumer != utc)
-		return 0;
+	tu = container_of(con, struct trace_uprobe, consumer);
+	tu->nhit++;
 
 	if (tu->flags & TP_FLAG_TRACE)
-		uprobe_trace_func(tu, regs);
+		ret |= uprobe_trace_func(tu, regs);
 
 #ifdef CONFIG_PERF_EVENTS
 	if (tu->flags & TP_FLAG_PROFILE)
-		uprobe_perf_func(tu, regs);
+		ret |= uprobe_perf_func(tu, regs);
 #endif
-	return 0;
+	return ret;
 }
 
 static struct trace_event_functions uprobe_funcs = {
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index d96ba22dabfa..0c05a4592047 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -192,12 +192,11 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry,
 static struct tracepoint_entry *get_tracepoint(const char *name)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct tracepoint_entry *e;
 	u32 hash = jhash(name, strlen(name), 0);
 
 	head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)];
-	hlist_for_each_entry(e, node, head, hlist) {
+	hlist_for_each_entry(e, head, hlist) {
 		if (!strcmp(name, e->name))
 			return e;
 	}
@@ -211,13 +210,12 @@ static struct tracepoint_entry *get_tracepoint(const char *name)
 static struct tracepoint_entry *add_tracepoint(const char *name)
 {
 	struct hlist_head *head;
-	struct hlist_node *node;
 	struct tracepoint_entry *e;
 	size_t name_len = strlen(name) + 1;
 	u32 hash = jhash(name, name_len-1, 0);
 
 	head = &tracepoint_table[hash & (TRACEPOINT_TABLE_SIZE - 1)];
-	hlist_for_each_entry(e, node, head, hlist) {
+	hlist_for_each_entry(e, head, hlist) {
 		if (!strcmp(name, e->name)) {
 			printk(KERN_NOTICE
 				"tracepoint %s busy\n", name);
diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 625df0b44690..a1dd9a1b1327 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -32,6 +32,7 @@ void bacct_add_tsk(struct user_namespace *user_ns,
 {
 	const struct cred *tcred;
 	struct timespec uptime, ts;
+	cputime_t utime, stime, utimescaled, stimescaled;
 	u64 ac_etime;
 
 	BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
@@ -65,10 +66,15 @@ void bacct_add_tsk(struct user_namespace *user_ns,
 	stats->ac_ppid	 = pid_alive(tsk) ?
 		task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
 	rcu_read_unlock();
-	stats->ac_utime = cputime_to_usecs(tsk->utime);
-	stats->ac_stime = cputime_to_usecs(tsk->stime);
-	stats->ac_utimescaled = cputime_to_usecs(tsk->utimescaled);
-	stats->ac_stimescaled = cputime_to_usecs(tsk->stimescaled);
+
+	task_cputime(tsk, &utime, &stime);
+	stats->ac_utime = cputime_to_usecs(utime);
+	stats->ac_stime = cputime_to_usecs(stime);
+
+	task_cputime_scaled(tsk, &utimescaled, &stimescaled);
+	stats->ac_utimescaled = cputime_to_usecs(utimescaled);
+	stats->ac_stimescaled = cputime_to_usecs(stimescaled);
+
 	stats->ac_minflt = tsk->min_flt;
 	stats->ac_majflt = tsk->maj_flt;
 
@@ -115,11 +121,8 @@ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
 #undef KB
 #undef MB
 
-/**
- * acct_update_integrals - update mm integral fields in task_struct
- * @tsk: task_struct for accounting
- */
-void acct_update_integrals(struct task_struct *tsk)
+static void __acct_update_integrals(struct task_struct *tsk,
+				    cputime_t utime, cputime_t stime)
 {
 	if (likely(tsk->mm)) {
 		cputime_t time, dtime;
@@ -128,7 +131,7 @@ void acct_update_integrals(struct task_struct *tsk)
 		u64 delta;
 
 		local_irq_save(flags);
-		time = tsk->stime + tsk->utime;
+		time = stime + utime;
 		dtime = time - tsk->acct_timexpd;
 		jiffies_to_timeval(cputime_to_jiffies(dtime), &value);
 		delta = value.tv_sec;
@@ -145,6 +148,27 @@ void acct_update_integrals(struct task_struct *tsk)
 }
 
 /**
+ * acct_update_integrals - update mm integral fields in task_struct
+ * @tsk: task_struct for accounting
+ */
+void acct_update_integrals(struct task_struct *tsk)
+{
+	cputime_t utime, stime;
+
+	task_cputime(tsk, &utime, &stime);
+	__acct_update_integrals(tsk, utime, stime);
+}
+
+/**
+ * acct_account_cputime - update mm integral after cputime update
+ * @tsk: task_struct for accounting
+ */
+void acct_account_cputime(struct task_struct *tsk)
+{
+	__acct_update_integrals(tsk, tsk->utime, tsk->stime);
+}
+
+/**
  * acct_clear_integrals - clear the mm integral fields in task_struct
  * @tsk: task_struct whose accounting fields are cleared
  */
diff --git a/kernel/user-return-notifier.c b/kernel/user-return-notifier.c
index 1744bb80f1fb..394f70b17162 100644
--- a/kernel/user-return-notifier.c
+++ b/kernel/user-return-notifier.c
@@ -34,11 +34,11 @@ EXPORT_SYMBOL_GPL(user_return_notifier_unregister);
 void fire_user_return_notifiers(void)
 {
 	struct user_return_notifier *urn;
-	struct hlist_node *tmp1, *tmp2;
+	struct hlist_node *tmp2;
 	struct hlist_head *head;
 
 	head = &get_cpu_var(return_notifier_list);
-	hlist_for_each_entry_safe(urn, tmp1, tmp2, head, link)
+	hlist_for_each_entry_safe(urn, tmp2, head, link)
 		urn->on_user_return(urn);
 	put_cpu_var(return_notifier_list);
 }
diff --git a/kernel/user.c b/kernel/user.c
index 33acb5e53a5f..e81978e8c03b 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -47,9 +47,7 @@ struct user_namespace init_user_ns = {
 			.count = 4294967295U,
 		},
 	},
-	.kref = {
-		.refcount	= ATOMIC_INIT(3),
-	},
+	.count = ATOMIC_INIT(3),
 	.owner = GLOBAL_ROOT_UID,
 	.group = GLOBAL_ROOT_GID,
 	.proc_inum = PROC_USER_INIT_INO,
@@ -107,9 +105,8 @@ static void uid_hash_remove(struct user_struct *up)
 static struct user_struct *uid_hash_find(kuid_t uid, struct hlist_head *hashent)
 {
 	struct user_struct *user;
-	struct hlist_node *h;
 
-	hlist_for_each_entry(user, h, hashent, uidhash_node) {
+	hlist_for_each_entry(user, hashent, uidhash_node) {
 		if (uid_eq(user->uid, uid)) {
 			atomic_inc(&user->__count);
 			return user;
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 2b042c42fbc4..b14f4d342043 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -21,6 +21,7 @@
 #include <linux/uaccess.h>
 #include <linux/ctype.h>
 #include <linux/projid.h>
+#include <linux/fs_struct.h>
 
 static struct kmem_cache *user_ns_cachep __read_mostly;
 
@@ -78,7 +79,7 @@ int create_user_ns(struct cred *new)
 		return ret;
 	}
 
-	kref_init(&ns->kref);
+	atomic_set(&ns->count, 1);
 	/* Leave the new->user_ns reference with the new user namespace. */
 	ns->parent = parent_ns;
 	ns->owner = owner;
@@ -104,15 +105,16 @@ int unshare_userns(unsigned long unshare_flags, struct cred **new_cred)
 	return create_user_ns(cred);
 }
 
-void free_user_ns(struct kref *kref)
+void free_user_ns(struct user_namespace *ns)
 {
-	struct user_namespace *parent, *ns =
-		container_of(kref, struct user_namespace, kref);
+	struct user_namespace *parent;
 
-	parent = ns->parent;
-	proc_free_inum(ns->proc_inum);
-	kmem_cache_free(user_ns_cachep, ns);
-	put_user_ns(parent);
+	do {
+		parent = ns->parent;
+		proc_free_inum(ns->proc_inum);
+		kmem_cache_free(user_ns_cachep, ns);
+		ns = parent;
+	} while (atomic_dec_and_test(&parent->count));
 }
 EXPORT_SYMBOL(free_user_ns);
 
@@ -519,6 +521,42 @@ struct seq_operations proc_projid_seq_operations = {
 	.show = projid_m_show,
 };
 
+static bool mappings_overlap(struct uid_gid_map *new_map, struct uid_gid_extent *extent)
+{
+	u32 upper_first, lower_first, upper_last, lower_last;
+	unsigned idx;
+
+	upper_first = extent->first;
+	lower_first = extent->lower_first;
+	upper_last = upper_first + extent->count - 1;
+	lower_last = lower_first + extent->count - 1;
+
+	for (idx = 0; idx < new_map->nr_extents; idx++) {
+		u32 prev_upper_first, prev_lower_first;
+		u32 prev_upper_last, prev_lower_last;
+		struct uid_gid_extent *prev;
+
+		prev = &new_map->extent[idx];
+
+		prev_upper_first = prev->first;
+		prev_lower_first = prev->lower_first;
+		prev_upper_last = prev_upper_first + prev->count - 1;
+		prev_lower_last = prev_lower_first + prev->count - 1;
+
+		/* Does the upper range intersect a previous extent? */
+		if ((prev_upper_first <= upper_last) &&
+		    (prev_upper_last >= upper_first))
+			return true;
+
+		/* Does the lower range intersect a previous extent? */
+		if ((prev_lower_first <= lower_last) &&
+		    (prev_lower_last >= lower_first))
+			return true;
+	}
+	return false;
+}
+
+
 static DEFINE_MUTEX(id_map_mutex);
 
 static ssize_t map_write(struct file *file, const char __user *buf,
@@ -531,7 +569,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
 	struct user_namespace *ns = seq->private;
 	struct uid_gid_map new_map;
 	unsigned idx;
-	struct uid_gid_extent *extent, *last = NULL;
+	struct uid_gid_extent *extent = NULL;
 	unsigned long page = 0;
 	char *kbuf, *pos, *next_line;
 	ssize_t ret = -EINVAL;
@@ -634,14 +672,11 @@ static ssize_t map_write(struct file *file, const char __user *buf,
 		if ((extent->lower_first + extent->count) <= extent->lower_first)
 			goto out;
 
-		/* For now only accept extents that are strictly in order */
-		if (last &&
-		    (((last->first + last->count) > extent->first) ||
-		     ((last->lower_first + last->count) > extent->lower_first)))
+		/* Do the ranges in extent overlap any previous extents? */
+		if (mappings_overlap(&new_map, extent))
 			goto out;
 
 		new_map.nr_extents++;
-		last = extent;
 
 		/* Fail if the file contains too many extents */
 		if ((new_map.nr_extents == UID_GID_MAP_MAX_EXTENTS) &&
@@ -803,6 +838,9 @@ static int userns_install(struct nsproxy *nsproxy, void *ns)
 	if (atomic_read(&current->mm->mm_users) > 1)
 		return -EINVAL;
 
+	if (current->fs->users != 1)
+		return -EINVAL;
+
 	if (!ns_capable(user_ns, CAP_SYS_ADMIN))
 		return -EPERM;
 
diff --git a/kernel/utsname.c b/kernel/utsname.c
index 08b197e8c485..a47fc5de3113 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -30,7 +30,7 @@ static struct uts_namespace *create_uts_ns(void)
 /*
  * Clone a new ns copying an original utsname, setting refcount to 1
  * @old_ns: namespace to clone
- * Return NULL on error (failure to kmalloc), new ns otherwise
+ * Return ERR_PTR(-ENOMEM) on error (failure to kmalloc), new ns otherwise
  */
 static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns,
 					  struct uts_namespace *old_ns)
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
index 63da38c2d820..4f69f9a5e221 100644
--- a/kernel/utsname_sysctl.c
+++ b/kernel/utsname_sysctl.c
@@ -15,6 +15,8 @@
 #include <linux/sysctl.h>
 #include <linux/wait.h>
 
+#ifdef CONFIG_PROC_SYSCTL
+
 static void *get_uts(ctl_table *table, int write)
 {
 	char *which = table->data;
@@ -38,7 +40,6 @@ static void put_uts(ctl_table *table, int write, void *which)
 		up_write(&uts_sem);
 }
 
-#ifdef CONFIG_PROC_SYSCTL
 /*
  *	Special case of dostring for the UTS structure. This has locks
  *	to observe. Should this be in kernel/sys.c ????
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 75a2ab3d0b02..4a944676358e 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -23,6 +23,7 @@
 #include <linux/module.h>
 #include <linux/sysctl.h>
 #include <linux/smpboot.h>
+#include <linux/sched/rt.h>
 
 #include <asm/irq_regs.h>
 #include <linux/kvm_para.h>
@@ -112,9 +113,9 @@ static int get_softlockup_thresh(void)
  * resolution, and we don't need to waste time with a big divide when
  * 2^30ns == 1.074s.
  */
-static unsigned long get_timestamp(int this_cpu)
+static unsigned long get_timestamp(void)
 {
-	return cpu_clock(this_cpu) >> 30LL;  /* 2^30 ~= 10^9 */
+	return local_clock() >> 30LL;  /* 2^30 ~= 10^9 */
 }
 
 static void set_sample_period(void)
@@ -132,9 +133,7 @@ static void set_sample_period(void)
 /* Commands for resetting the watchdog */
 static void __touch_watchdog(void)
 {
-	int this_cpu = smp_processor_id();
-
-	__this_cpu_write(watchdog_touch_ts, get_timestamp(this_cpu));
+	__this_cpu_write(watchdog_touch_ts, get_timestamp());
 }
 
 void touch_softlockup_watchdog(void)
@@ -195,7 +194,7 @@ static int is_hardlockup(void)
 
 static int is_softlockup(unsigned long touch_ts)
 {
-	unsigned long now = get_timestamp(smp_processor_id());
+	unsigned long now = get_timestamp();
 
 	/* Warn about unreasonable delays: */
 	if (time_after(now, touch_ts + get_softlockup_thresh()))
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index fbc6576a83c3..55fac5b991b7 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -41,32 +41,31 @@
 #include <linux/debug_locks.h>
 #include <linux/lockdep.h>
 #include <linux/idr.h>
+#include <linux/hashtable.h>
 
-#include "workqueue_sched.h"
+#include "workqueue_internal.h"
 
 enum {
 	/*
-	 * global_cwq flags
+	 * worker_pool flags
 	 *
-	 * A bound gcwq is either associated or disassociated with its CPU.
+	 * A bound pool is either associated or disassociated with its CPU.
 	 * While associated (!DISASSOCIATED), all workers are bound to the
 	 * CPU and none has %WORKER_UNBOUND set and concurrency management
 	 * is in effect.
 	 *
 	 * While DISASSOCIATED, the cpu may be offline and all workers have
 	 * %WORKER_UNBOUND set and concurrency management disabled, and may
-	 * be executing on any CPU.  The gcwq behaves as an unbound one.
+	 * be executing on any CPU.  The pool behaves as an unbound one.
 	 *
 	 * Note that DISASSOCIATED can be flipped only while holding
-	 * assoc_mutex of all pools on the gcwq to avoid changing binding
-	 * state while create_worker() is in progress.
+	 * assoc_mutex to avoid changing binding state while
+	 * create_worker() is in progress.
 	 */
-	GCWQ_DISASSOCIATED	= 1 << 0,	/* cpu can't serve workers */
-	GCWQ_FREEZING		= 1 << 1,	/* freeze in progress */
-
-	/* pool flags */
 	POOL_MANAGE_WORKERS	= 1 << 0,	/* need to manage workers */
 	POOL_MANAGING_WORKERS   = 1 << 1,       /* managing workers */
+	POOL_DISASSOCIATED	= 1 << 2,	/* cpu can't serve workers */
+	POOL_FREEZING		= 1 << 3,	/* freeze in progress */
 
 	/* worker flags */
 	WORKER_STARTED		= 1 << 0,	/* started */
@@ -79,11 +78,9 @@ enum {
 	WORKER_NOT_RUNNING	= WORKER_PREP | WORKER_UNBOUND |
 				  WORKER_CPU_INTENSIVE,
 
-	NR_WORKER_POOLS		= 2,		/* # worker pools per gcwq */
+	NR_STD_WORKER_POOLS	= 2,		/* # standard pools per cpu */
 
 	BUSY_WORKER_HASH_ORDER	= 6,		/* 64 pointers */
-	BUSY_WORKER_HASH_SIZE	= 1 << BUSY_WORKER_HASH_ORDER,
-	BUSY_WORKER_HASH_MASK	= BUSY_WORKER_HASH_SIZE - 1,
 
 	MAX_IDLE_WORKERS_RATIO	= 4,		/* 1/4 of busy can be idle */
 	IDLE_WORKER_TIMEOUT	= 300 * HZ,	/* keep idle ones for 5 mins */
@@ -111,48 +108,24 @@ enum {
  * P: Preemption protected.  Disabling preemption is enough and should
  *    only be modified and accessed from the local cpu.
  *
- * L: gcwq->lock protected.  Access with gcwq->lock held.
+ * L: pool->lock protected.  Access with pool->lock held.
  *
- * X: During normal operation, modification requires gcwq->lock and
- *    should be done only from local cpu.  Either disabling preemption
- *    on local cpu or grabbing gcwq->lock is enough for read access.
- *    If GCWQ_DISASSOCIATED is set, it's identical to L.
+ * X: During normal operation, modification requires pool->lock and should
+ *    be done only from local cpu.  Either disabling preemption on local
+ *    cpu or grabbing pool->lock is enough for read access.  If
+ *    POOL_DISASSOCIATED is set, it's identical to L.
  *
  * F: wq->flush_mutex protected.
  *
  * W: workqueue_lock protected.
  */
 
-struct global_cwq;
-struct worker_pool;
-
-/*
- * The poor guys doing the actual heavy lifting.  All on-duty workers
- * are either serving the manager role, on idle list or on busy hash.
- */
-struct worker {
-	/* on idle list while idle, on busy hash table while busy */
-	union {
-		struct list_head	entry;	/* L: while idle */
-		struct hlist_node	hentry;	/* L: while busy */
-	};
-
-	struct work_struct	*current_work;	/* L: work being processed */
-	struct cpu_workqueue_struct *current_cwq; /* L: current_work's cwq */
-	struct list_head	scheduled;	/* L: scheduled works */
-	struct task_struct	*task;		/* I: worker task */
-	struct worker_pool	*pool;		/* I: the associated pool */
-	/* 64 bytes boundary on 64bit, 32 on 32bit */
-	unsigned long		last_active;	/* L: last active timestamp */
-	unsigned int		flags;		/* X: flags */
-	int			id;		/* I: worker id */
-
-	/* for rebinding worker to CPU */
-	struct work_struct	rebind_work;	/* L: for busy worker */
-};
+/* struct worker is defined in workqueue_internal.h */
 
 struct worker_pool {
-	struct global_cwq	*gcwq;		/* I: the owning gcwq */
+	spinlock_t		lock;		/* the pool lock */
+	unsigned int		cpu;		/* I: the associated cpu */
+	int			id;		/* I: pool ID */
 	unsigned int		flags;		/* X: flags */
 
 	struct list_head	worklist;	/* L: list of pending works */
@@ -165,34 +138,28 @@ struct worker_pool {
 	struct timer_list	idle_timer;	/* L: worker idle timeout */
 	struct timer_list	mayday_timer;	/* L: SOS timer for workers */
 
-	struct mutex		assoc_mutex;	/* protect GCWQ_DISASSOCIATED */
-	struct ida		worker_ida;	/* L: for worker IDs */
-};
-
-/*
- * Global per-cpu workqueue.  There's one and only one for each cpu
- * and all works are queued and processed here regardless of their
- * target workqueues.
- */
-struct global_cwq {
-	spinlock_t		lock;		/* the gcwq lock */
-	unsigned int		cpu;		/* I: the associated cpu */
-	unsigned int		flags;		/* L: GCWQ_* flags */
-
-	/* workers are chained either in busy_hash or pool idle_list */
-	struct hlist_head	busy_hash[BUSY_WORKER_HASH_SIZE];
+	/* workers are chained either in busy_hash or idle_list */
+	DECLARE_HASHTABLE(busy_hash, BUSY_WORKER_HASH_ORDER);
 						/* L: hash of busy workers */
 
-	struct worker_pool	pools[NR_WORKER_POOLS];
-						/* normal and highpri pools */
+	struct mutex		assoc_mutex;	/* protect POOL_DISASSOCIATED */
+	struct ida		worker_ida;	/* L: for worker IDs */
+
+	/*
+	 * The current concurrency level.  As it's likely to be accessed
+	 * from other CPUs during try_to_wake_up(), put it in a separate
+	 * cacheline.
+	 */
+	atomic_t		nr_running ____cacheline_aligned_in_smp;
 } ____cacheline_aligned_in_smp;
 
 /*
- * The per-CPU workqueue.  The lower WORK_STRUCT_FLAG_BITS of
- * work_struct->data are used for flags and thus cwqs need to be
- * aligned at two's power of the number of flag bits.
+ * The per-pool workqueue.  While queued, the lower WORK_STRUCT_FLAG_BITS
+ * of work_struct->data are used for flags and the remaining high bits
+ * point to the pwq; thus, pwqs need to be aligned at two's power of the
+ * number of flag bits.
  */
-struct cpu_workqueue_struct {
+struct pool_workqueue {
 	struct worker_pool	*pool;		/* I: the associated pool */
 	struct workqueue_struct *wq;		/* I: the owning workqueue */
 	int			work_color;	/* L: current color */
@@ -241,16 +208,16 @@ typedef unsigned long mayday_mask_t;
 struct workqueue_struct {
 	unsigned int		flags;		/* W: WQ_* flags */
 	union {
-		struct cpu_workqueue_struct __percpu	*pcpu;
-		struct cpu_workqueue_struct		*single;
+		struct pool_workqueue __percpu		*pcpu;
+		struct pool_workqueue			*single;
 		unsigned long				v;
-	} cpu_wq;				/* I: cwq's */
+	} pool_wq;				/* I: pwq's */
 	struct list_head	list;		/* W: list of all workqueues */
 
 	struct mutex		flush_mutex;	/* protects wq flushing */
 	int			work_color;	/* F: current work color */
 	int			flush_color;	/* F: current flush color */
-	atomic_t		nr_cwqs_to_flush; /* flush in progress */
+	atomic_t		nr_pwqs_to_flush; /* flush in progress */
 	struct wq_flusher	*first_flusher;	/* F: first flusher */
 	struct list_head	flusher_queue;	/* F: flush waiters */
 	struct list_head	flusher_overflow; /* F: flush overflow list */
@@ -259,7 +226,7 @@ struct workqueue_struct {
 	struct worker		*rescuer;	/* I: rescue worker */
 
 	int			nr_drainers;	/* W: drain in progress */
-	int			saved_max_active; /* W: saved cwq max_active */
+	int			saved_max_active; /* W: saved pwq max_active */
 #ifdef CONFIG_LOCKDEP
 	struct lockdep_map	lockdep_map;
 #endif
@@ -280,16 +247,15 @@ EXPORT_SYMBOL_GPL(system_freezable_wq);
 #define CREATE_TRACE_POINTS
 #include <trace/events/workqueue.h>
 
-#define for_each_worker_pool(pool, gcwq)				\
-	for ((pool) = &(gcwq)->pools[0];				\
-	     (pool) < &(gcwq)->pools[NR_WORKER_POOLS]; (pool)++)
+#define for_each_std_worker_pool(pool, cpu)				\
+	for ((pool) = &std_worker_pools(cpu)[0];			\
+	     (pool) < &std_worker_pools(cpu)[NR_STD_WORKER_POOLS]; (pool)++)
 
-#define for_each_busy_worker(worker, i, pos, gcwq)			\
-	for (i = 0; i < BUSY_WORKER_HASH_SIZE; i++)			\
-		hlist_for_each_entry(worker, pos, &gcwq->busy_hash[i], hentry)
+#define for_each_busy_worker(worker, i, pool)				\
+	hash_for_each(pool->busy_hash, i, worker, hentry)
 
-static inline int __next_gcwq_cpu(int cpu, const struct cpumask *mask,
-				  unsigned int sw)
+static inline int __next_wq_cpu(int cpu, const struct cpumask *mask,
+				unsigned int sw)
 {
 	if (cpu < nr_cpu_ids) {
 		if (sw & 1) {
@@ -300,42 +266,42 @@ static inline int __next_gcwq_cpu(int cpu, const struct cpumask *mask,
 		if (sw & 2)
 			return WORK_CPU_UNBOUND;
 	}
-	return WORK_CPU_NONE;
+	return WORK_CPU_END;
 }
 
-static inline int __next_wq_cpu(int cpu, const struct cpumask *mask,
-				struct workqueue_struct *wq)
+static inline int __next_pwq_cpu(int cpu, const struct cpumask *mask,
+				 struct workqueue_struct *wq)
 {
-	return __next_gcwq_cpu(cpu, mask, !(wq->flags & WQ_UNBOUND) ? 1 : 2);
+	return __next_wq_cpu(cpu, mask, !(wq->flags & WQ_UNBOUND) ? 1 : 2);
 }
 
 /*
  * CPU iterators
  *
- * An extra gcwq is defined for an invalid cpu number
+ * An extra cpu number is defined using an invalid cpu number
  * (WORK_CPU_UNBOUND) to host workqueues which are not bound to any
- * specific CPU.  The following iterators are similar to
- * for_each_*_cpu() iterators but also considers the unbound gcwq.
+ * specific CPU.  The following iterators are similar to for_each_*_cpu()
+ * iterators but also considers the unbound CPU.
  *
- * for_each_gcwq_cpu()		: possible CPUs + WORK_CPU_UNBOUND
- * for_each_online_gcwq_cpu()	: online CPUs + WORK_CPU_UNBOUND
- * for_each_cwq_cpu()		: possible CPUs for bound workqueues,
+ * for_each_wq_cpu()		: possible CPUs + WORK_CPU_UNBOUND
+ * for_each_online_wq_cpu()	: online CPUs + WORK_CPU_UNBOUND
+ * for_each_pwq_cpu()		: possible CPUs for bound workqueues,
  *				  WORK_CPU_UNBOUND for unbound workqueues
  */
-#define for_each_gcwq_cpu(cpu)						\
-	for ((cpu) = __next_gcwq_cpu(-1, cpu_possible_mask, 3);		\
-	     (cpu) < WORK_CPU_NONE;					\
-	     (cpu) = __next_gcwq_cpu((cpu), cpu_possible_mask, 3))
+#define for_each_wq_cpu(cpu)						\
+	for ((cpu) = __next_wq_cpu(-1, cpu_possible_mask, 3);		\
+	     (cpu) < WORK_CPU_END;					\
+	     (cpu) = __next_wq_cpu((cpu), cpu_possible_mask, 3))
 
-#define for_each_online_gcwq_cpu(cpu)					\
-	for ((cpu) = __next_gcwq_cpu(-1, cpu_online_mask, 3);		\
-	     (cpu) < WORK_CPU_NONE;					\
-	     (cpu) = __next_gcwq_cpu((cpu), cpu_online_mask, 3))
+#define for_each_online_wq_cpu(cpu)					\
+	for ((cpu) = __next_wq_cpu(-1, cpu_online_mask, 3);		\
+	     (cpu) < WORK_CPU_END;					\
+	     (cpu) = __next_wq_cpu((cpu), cpu_online_mask, 3))
 
-#define for_each_cwq_cpu(cpu, wq)					\
-	for ((cpu) = __next_wq_cpu(-1, cpu_possible_mask, (wq));	\
-	     (cpu) < WORK_CPU_NONE;					\
-	     (cpu) = __next_wq_cpu((cpu), cpu_possible_mask, (wq)))
+#define for_each_pwq_cpu(cpu, wq)					\
+	for ((cpu) = __next_pwq_cpu(-1, cpu_possible_mask, (wq));	\
+	     (cpu) < WORK_CPU_END;					\
+	     (cpu) = __next_pwq_cpu((cpu), cpu_possible_mask, (wq)))
 
 #ifdef CONFIG_DEBUG_OBJECTS_WORK
 
@@ -459,57 +425,70 @@ static LIST_HEAD(workqueues);
 static bool workqueue_freezing;		/* W: have wqs started freezing? */
 
 /*
- * The almighty global cpu workqueues.  nr_running is the only field
- * which is expected to be used frequently by other cpus via
- * try_to_wake_up().  Put it in a separate cacheline.
+ * The CPU and unbound standard worker pools.  The unbound ones have
+ * POOL_DISASSOCIATED set, and their workers have WORKER_UNBOUND set.
  */
-static DEFINE_PER_CPU(struct global_cwq, global_cwq);
-static DEFINE_PER_CPU_SHARED_ALIGNED(atomic_t, pool_nr_running[NR_WORKER_POOLS]);
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct worker_pool [NR_STD_WORKER_POOLS],
+				     cpu_std_worker_pools);
+static struct worker_pool unbound_std_worker_pools[NR_STD_WORKER_POOLS];
 
-/*
- * Global cpu workqueue and nr_running counter for unbound gcwq.  The
- * gcwq is always online, has GCWQ_DISASSOCIATED set, and all its
- * workers have WORKER_UNBOUND set.
- */
-static struct global_cwq unbound_global_cwq;
-static atomic_t unbound_pool_nr_running[NR_WORKER_POOLS] = {
-	[0 ... NR_WORKER_POOLS - 1]	= ATOMIC_INIT(0),	/* always 0 */
-};
+/* idr of all pools */
+static DEFINE_MUTEX(worker_pool_idr_mutex);
+static DEFINE_IDR(worker_pool_idr);
 
 static int worker_thread(void *__worker);
 
-static int worker_pool_pri(struct worker_pool *pool)
+static struct worker_pool *std_worker_pools(int cpu)
 {
-	return pool - pool->gcwq->pools;
+	if (cpu != WORK_CPU_UNBOUND)
+		return per_cpu(cpu_std_worker_pools, cpu);
+	else
+		return unbound_std_worker_pools;
 }
 
-static struct global_cwq *get_gcwq(unsigned int cpu)
+static int std_worker_pool_pri(struct worker_pool *pool)
 {
-	if (cpu != WORK_CPU_UNBOUND)
-		return &per_cpu(global_cwq, cpu);
-	else
-		return &unbound_global_cwq;
+	return pool - std_worker_pools(pool->cpu);
 }
 
-static atomic_t *get_pool_nr_running(struct worker_pool *pool)
+/* allocate ID and assign it to @pool */
+static int worker_pool_assign_id(struct worker_pool *pool)
 {
-	int cpu = pool->gcwq->cpu;
-	int idx = worker_pool_pri(pool);
+	int ret;
 
-	if (cpu != WORK_CPU_UNBOUND)
-		return &per_cpu(pool_nr_running, cpu)[idx];
-	else
-		return &unbound_pool_nr_running[idx];
+	mutex_lock(&worker_pool_idr_mutex);
+	ret = idr_alloc(&worker_pool_idr, pool, 0, 0, GFP_KERNEL);
+	if (ret >= 0)
+		pool->id = ret;
+	mutex_unlock(&worker_pool_idr_mutex);
+
+	return ret < 0 ? ret : 0;
+}
+
+/*
+ * Lookup worker_pool by id.  The idr currently is built during boot and
+ * never modified.  Don't worry about locking for now.
+ */
+static struct worker_pool *worker_pool_by_id(int pool_id)
+{
+	return idr_find(&worker_pool_idr, pool_id);
 }
 
-static struct cpu_workqueue_struct *get_cwq(unsigned int cpu,
-					    struct workqueue_struct *wq)
+static struct worker_pool *get_std_worker_pool(int cpu, bool highpri)
+{
+	struct worker_pool *pools = std_worker_pools(cpu);
+
+	return &pools[highpri];
+}
+
+static struct pool_workqueue *get_pwq(unsigned int cpu,
+				      struct workqueue_struct *wq)
 {
 	if (!(wq->flags & WQ_UNBOUND)) {
 		if (likely(cpu < nr_cpu_ids))
-			return per_cpu_ptr(wq->cpu_wq.pcpu, cpu);
+			return per_cpu_ptr(wq->pool_wq.pcpu, cpu);
 	} else if (likely(cpu == WORK_CPU_UNBOUND))
-		return wq->cpu_wq.single;
+		return wq->pool_wq.single;
 	return NULL;
 }
 
@@ -530,19 +509,19 @@ static int work_next_color(int color)
 }
 
 /*
- * While queued, %WORK_STRUCT_CWQ is set and non flag bits of a work's data
- * contain the pointer to the queued cwq.  Once execution starts, the flag
- * is cleared and the high bits contain OFFQ flags and CPU number.
+ * While queued, %WORK_STRUCT_PWQ is set and non flag bits of a work's data
+ * contain the pointer to the queued pwq.  Once execution starts, the flag
+ * is cleared and the high bits contain OFFQ flags and pool ID.
  *
- * set_work_cwq(), set_work_cpu_and_clear_pending(), mark_work_canceling()
- * and clear_work_data() can be used to set the cwq, cpu or clear
+ * set_work_pwq(), set_work_pool_and_clear_pending(), mark_work_canceling()
+ * and clear_work_data() can be used to set the pwq, pool or clear
  * work->data.  These functions should only be called while the work is
  * owned - ie. while the PENDING bit is set.
  *
- * get_work_[g]cwq() can be used to obtain the gcwq or cwq corresponding to
- * a work.  gcwq is available once the work has been queued anywhere after
- * initialization until it is sync canceled.  cwq is available only while
- * the work item is queued.
+ * get_work_pool() and get_work_pwq() can be used to obtain the pool or pwq
+ * corresponding to a work.  Pool is available once the work has been
+ * queued anywhere after initialization until it is sync canceled.  pwq is
+ * available only while the work item is queued.
  *
  * %WORK_OFFQ_CANCELING is used to mark a work item which is being
  * canceled.  While being canceled, a work item may have its PENDING set
@@ -556,16 +535,22 @@ static inline void set_work_data(struct work_struct *work, unsigned long data,
 	atomic_long_set(&work->data, data | flags | work_static(work));
 }
 
-static void set_work_cwq(struct work_struct *work,
-			 struct cpu_workqueue_struct *cwq,
+static void set_work_pwq(struct work_struct *work, struct pool_workqueue *pwq,
 			 unsigned long extra_flags)
 {
-	set_work_data(work, (unsigned long)cwq,
-		      WORK_STRUCT_PENDING | WORK_STRUCT_CWQ | extra_flags);
+	set_work_data(work, (unsigned long)pwq,
+		      WORK_STRUCT_PENDING | WORK_STRUCT_PWQ | extra_flags);
 }
 
-static void set_work_cpu_and_clear_pending(struct work_struct *work,
-					   unsigned int cpu)
+static void set_work_pool_and_keep_pending(struct work_struct *work,
+					   int pool_id)
+{
+	set_work_data(work, (unsigned long)pool_id << WORK_OFFQ_POOL_SHIFT,
+		      WORK_STRUCT_PENDING);
+}
+
+static void set_work_pool_and_clear_pending(struct work_struct *work,
+					    int pool_id)
 {
 	/*
 	 * The following wmb is paired with the implied mb in
@@ -574,67 +559,92 @@ static void set_work_cpu_and_clear_pending(struct work_struct *work,
 	 * owner.
 	 */
 	smp_wmb();
-	set_work_data(work, (unsigned long)cpu << WORK_OFFQ_CPU_SHIFT, 0);
+	set_work_data(work, (unsigned long)pool_id << WORK_OFFQ_POOL_SHIFT, 0);
 }
 
 static void clear_work_data(struct work_struct *work)
 {
-	smp_wmb();	/* see set_work_cpu_and_clear_pending() */
-	set_work_data(work, WORK_STRUCT_NO_CPU, 0);
+	smp_wmb();	/* see set_work_pool_and_clear_pending() */
+	set_work_data(work, WORK_STRUCT_NO_POOL, 0);
 }
 
-static struct cpu_workqueue_struct *get_work_cwq(struct work_struct *work)
+static struct pool_workqueue *get_work_pwq(struct work_struct *work)
 {
 	unsigned long data = atomic_long_read(&work->data);
 
-	if (data & WORK_STRUCT_CWQ)
+	if (data & WORK_STRUCT_PWQ)
 		return (void *)(data & WORK_STRUCT_WQ_DATA_MASK);
 	else
 		return NULL;
 }
 
-static struct global_cwq *get_work_gcwq(struct work_struct *work)
+/**
+ * get_work_pool - return the worker_pool a given work was associated with
+ * @work: the work item of interest
+ *
+ * Return the worker_pool @work was last associated with.  %NULL if none.
+ */
+static struct worker_pool *get_work_pool(struct work_struct *work)
 {
 	unsigned long data = atomic_long_read(&work->data);
-	unsigned int cpu;
+	struct worker_pool *pool;
+	int pool_id;
 
-	if (data & WORK_STRUCT_CWQ)
-		return ((struct cpu_workqueue_struct *)
-			(data & WORK_STRUCT_WQ_DATA_MASK))->pool->gcwq;
+	if (data & WORK_STRUCT_PWQ)
+		return ((struct pool_workqueue *)
+			(data & WORK_STRUCT_WQ_DATA_MASK))->pool;
 
-	cpu = data >> WORK_OFFQ_CPU_SHIFT;
-	if (cpu == WORK_CPU_NONE)
+	pool_id = data >> WORK_OFFQ_POOL_SHIFT;
+	if (pool_id == WORK_OFFQ_POOL_NONE)
 		return NULL;
 
-	BUG_ON(cpu >= nr_cpu_ids && cpu != WORK_CPU_UNBOUND);
-	return get_gcwq(cpu);
+	pool = worker_pool_by_id(pool_id);
+	WARN_ON_ONCE(!pool);
+	return pool;
+}
+
+/**
+ * get_work_pool_id - return the worker pool ID a given work is associated with
+ * @work: the work item of interest
+ *
+ * Return the worker_pool ID @work was last associated with.
+ * %WORK_OFFQ_POOL_NONE if none.
+ */
+static int get_work_pool_id(struct work_struct *work)
+{
+	unsigned long data = atomic_long_read(&work->data);
+
+	if (data & WORK_STRUCT_PWQ)
+		return ((struct pool_workqueue *)
+			(data & WORK_STRUCT_WQ_DATA_MASK))->pool->id;
+
+	return data >> WORK_OFFQ_POOL_SHIFT;
 }
 
 static void mark_work_canceling(struct work_struct *work)
 {
-	struct global_cwq *gcwq = get_work_gcwq(work);
-	unsigned long cpu = gcwq ? gcwq->cpu : WORK_CPU_NONE;
+	unsigned long pool_id = get_work_pool_id(work);
 
-	set_work_data(work, (cpu << WORK_OFFQ_CPU_SHIFT) | WORK_OFFQ_CANCELING,
-		      WORK_STRUCT_PENDING);
+	pool_id <<= WORK_OFFQ_POOL_SHIFT;
+	set_work_data(work, pool_id | WORK_OFFQ_CANCELING, WORK_STRUCT_PENDING);
 }
 
 static bool work_is_canceling(struct work_struct *work)
 {
 	unsigned long data = atomic_long_read(&work->data);
 
-	return !(data & WORK_STRUCT_CWQ) && (data & WORK_OFFQ_CANCELING);
+	return !(data & WORK_STRUCT_PWQ) && (data & WORK_OFFQ_CANCELING);
 }
 
 /*
  * Policy functions.  These define the policies on how the global worker
  * pools are managed.  Unless noted otherwise, these functions assume that
- * they're being called with gcwq->lock held.
+ * they're being called with pool->lock held.
  */
 
 static bool __need_more_worker(struct worker_pool *pool)
 {
-	return !atomic_read(get_pool_nr_running(pool));
+	return !atomic_read(&pool->nr_running);
 }
 
 /*
@@ -642,7 +652,7 @@ static bool __need_more_worker(struct worker_pool *pool)
  * running workers.
  *
  * Note that, because unbound workers never contribute to nr_running, this
- * function will always return %true for unbound gcwq as long as the
+ * function will always return %true for unbound pools as long as the
  * worklist isn't empty.
  */
 static bool need_more_worker(struct worker_pool *pool)
@@ -659,9 +669,8 @@ static bool may_start_working(struct worker_pool *pool)
 /* Do I need to keep working?  Called from currently running workers. */
 static bool keep_working(struct worker_pool *pool)
 {
-	atomic_t *nr_running = get_pool_nr_running(pool);
-
-	return !list_empty(&pool->worklist) && atomic_read(nr_running) <= 1;
+	return !list_empty(&pool->worklist) &&
+		atomic_read(&pool->nr_running) <= 1;
 }
 
 /* Do we need a new worker?  Called from manager. */
@@ -714,7 +723,7 @@ static struct worker *first_worker(struct worker_pool *pool)
  * Wake up the first idle worker of @pool.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock).
+ * spin_lock_irq(pool->lock).
  */
 static void wake_up_worker(struct worker_pool *pool)
 {
@@ -740,8 +749,8 @@ void wq_worker_waking_up(struct task_struct *task, unsigned int cpu)
 	struct worker *worker = kthread_data(task);
 
 	if (!(worker->flags & WORKER_NOT_RUNNING)) {
-		WARN_ON_ONCE(worker->pool->gcwq->cpu != cpu);
-		atomic_inc(get_pool_nr_running(worker->pool));
+		WARN_ON_ONCE(worker->pool->cpu != cpu);
+		atomic_inc(&worker->pool->nr_running);
 	}
 }
 
@@ -764,12 +773,18 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task,
 				       unsigned int cpu)
 {
 	struct worker *worker = kthread_data(task), *to_wakeup = NULL;
-	struct worker_pool *pool = worker->pool;
-	atomic_t *nr_running = get_pool_nr_running(pool);
+	struct worker_pool *pool;
 
+	/*
+	 * Rescuers, which may not have all the fields set up like normal
+	 * workers, also reach here, let's not access anything before
+	 * checking NOT_RUNNING.
+	 */
 	if (worker->flags & WORKER_NOT_RUNNING)
 		return NULL;
 
+	pool = worker->pool;
+
 	/* this can only happen on the local cpu */
 	BUG_ON(cpu != raw_smp_processor_id());
 
@@ -781,10 +796,11 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task,
 	 * NOT_RUNNING is clear.  This means that we're bound to and
 	 * running on the local cpu w/ rq lock held and preemption
 	 * disabled, which in turn means that none else could be
-	 * manipulating idle_list, so dereferencing idle_list without gcwq
+	 * manipulating idle_list, so dereferencing idle_list without pool
 	 * lock is safe.
 	 */
-	if (atomic_dec_and_test(nr_running) && !list_empty(&pool->worklist))
+	if (atomic_dec_and_test(&pool->nr_running) &&
+	    !list_empty(&pool->worklist))
 		to_wakeup = first_worker(pool);
 	return to_wakeup ? to_wakeup->task : NULL;
 }
@@ -800,7 +816,7 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task,
  * woken up.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock)
+ * spin_lock_irq(pool->lock)
  */
 static inline void worker_set_flags(struct worker *worker, unsigned int flags,
 				    bool wakeup)
@@ -816,14 +832,12 @@ static inline void worker_set_flags(struct worker *worker, unsigned int flags,
 	 */
 	if ((flags & WORKER_NOT_RUNNING) &&
 	    !(worker->flags & WORKER_NOT_RUNNING)) {
-		atomic_t *nr_running = get_pool_nr_running(pool);
-
 		if (wakeup) {
-			if (atomic_dec_and_test(nr_running) &&
+			if (atomic_dec_and_test(&pool->nr_running) &&
 			    !list_empty(&pool->worklist))
 				wake_up_worker(pool);
 		} else
-			atomic_dec(nr_running);
+			atomic_dec(&pool->nr_running);
 	}
 
 	worker->flags |= flags;
@@ -837,7 +851,7 @@ static inline void worker_set_flags(struct worker *worker, unsigned int flags,
  * Clear @flags in @worker->flags and adjust nr_running accordingly.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock)
+ * spin_lock_irq(pool->lock)
  */
 static inline void worker_clr_flags(struct worker *worker, unsigned int flags)
 {
@@ -855,87 +869,55 @@ static inline void worker_clr_flags(struct worker *worker, unsigned int flags)
 	 */
 	if ((flags & WORKER_NOT_RUNNING) && (oflags & WORKER_NOT_RUNNING))
 		if (!(worker->flags & WORKER_NOT_RUNNING))
-			atomic_inc(get_pool_nr_running(pool));
+			atomic_inc(&pool->nr_running);
 }
 
 /**
- * busy_worker_head - return the busy hash head for a work
- * @gcwq: gcwq of interest
- * @work: work to be hashed
- *
- * Return hash head of @gcwq for @work.
- *
- * CONTEXT:
- * spin_lock_irq(gcwq->lock).
- *
- * RETURNS:
- * Pointer to the hash head.
- */
-static struct hlist_head *busy_worker_head(struct global_cwq *gcwq,
-					   struct work_struct *work)
-{
-	const int base_shift = ilog2(sizeof(struct work_struct));
-	unsigned long v = (unsigned long)work;
-
-	/* simple shift and fold hash, do we need something better? */
-	v >>= base_shift;
-	v += v >> BUSY_WORKER_HASH_ORDER;
-	v &= BUSY_WORKER_HASH_MASK;
-
-	return &gcwq->busy_hash[v];
-}
-
-/**
- * __find_worker_executing_work - find worker which is executing a work
- * @gcwq: gcwq of interest
- * @bwh: hash head as returned by busy_worker_head()
+ * find_worker_executing_work - find worker which is executing a work
+ * @pool: pool of interest
  * @work: work to find worker for
  *
- * Find a worker which is executing @work on @gcwq.  @bwh should be
- * the hash head obtained by calling busy_worker_head() with the same
- * work.
+ * Find a worker which is executing @work on @pool by searching
+ * @pool->busy_hash which is keyed by the address of @work.  For a worker
+ * to match, its current execution should match the address of @work and
+ * its work function.  This is to avoid unwanted dependency between
+ * unrelated work executions through a work item being recycled while still
+ * being executed.
+ *
+ * This is a bit tricky.  A work item may be freed once its execution
+ * starts and nothing prevents the freed area from being recycled for
+ * another work item.  If the same work item address ends up being reused
+ * before the original execution finishes, workqueue will identify the
+ * recycled work item as currently executing and make it wait until the
+ * current execution finishes, introducing an unwanted dependency.
+ *
+ * This function checks the work item address, work function and workqueue
+ * to avoid false positives.  Note that this isn't complete as one may
+ * construct a work function which can introduce dependency onto itself
+ * through a recycled work item.  Well, if somebody wants to shoot oneself
+ * in the foot that badly, there's only so much we can do, and if such
+ * deadlock actually occurs, it should be easy to locate the culprit work
+ * function.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock).
+ * spin_lock_irq(pool->lock).
  *
  * RETURNS:
  * Pointer to worker which is executing @work if found, NULL
  * otherwise.
  */
-static struct worker *__find_worker_executing_work(struct global_cwq *gcwq,
-						   struct hlist_head *bwh,
-						   struct work_struct *work)
+static struct worker *find_worker_executing_work(struct worker_pool *pool,
+						 struct work_struct *work)
 {
 	struct worker *worker;
-	struct hlist_node *tmp;
 
-	hlist_for_each_entry(worker, tmp, bwh, hentry)
-		if (worker->current_work == work)
+	hash_for_each_possible(pool->busy_hash, worker, hentry,
+			       (unsigned long)work)
+		if (worker->current_work == work &&
+		    worker->current_func == work->func)
 			return worker;
-	return NULL;
-}
 
-/**
- * find_worker_executing_work - find worker which is executing a work
- * @gcwq: gcwq of interest
- * @work: work to find worker for
- *
- * Find a worker which is executing @work on @gcwq.  This function is
- * identical to __find_worker_executing_work() except that this
- * function calculates @bwh itself.
- *
- * CONTEXT:
- * spin_lock_irq(gcwq->lock).
- *
- * RETURNS:
- * Pointer to worker which is executing @work if found, NULL
- * otherwise.
- */
-static struct worker *find_worker_executing_work(struct global_cwq *gcwq,
-						 struct work_struct *work)
-{
-	return __find_worker_executing_work(gcwq, busy_worker_head(gcwq, work),
-					    work);
+	return NULL;
 }
 
 /**
@@ -953,7 +935,7 @@ static struct worker *find_worker_executing_work(struct global_cwq *gcwq,
  * nested inside outer list_for_each_entry_safe().
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock).
+ * spin_lock_irq(pool->lock).
  */
 static void move_linked_works(struct work_struct *work, struct list_head *head,
 			      struct work_struct **nextp)
@@ -979,67 +961,67 @@ static void move_linked_works(struct work_struct *work, struct list_head *head,
 		*nextp = n;
 }
 
-static void cwq_activate_delayed_work(struct work_struct *work)
+static void pwq_activate_delayed_work(struct work_struct *work)
 {
-	struct cpu_workqueue_struct *cwq = get_work_cwq(work);
+	struct pool_workqueue *pwq = get_work_pwq(work);
 
 	trace_workqueue_activate_work(work);
-	move_linked_works(work, &cwq->pool->worklist, NULL);
+	move_linked_works(work, &pwq->pool->worklist, NULL);
 	__clear_bit(WORK_STRUCT_DELAYED_BIT, work_data_bits(work));
-	cwq->nr_active++;
+	pwq->nr_active++;
 }
 
-static void cwq_activate_first_delayed(struct cpu_workqueue_struct *cwq)
+static void pwq_activate_first_delayed(struct pool_workqueue *pwq)
 {
-	struct work_struct *work = list_first_entry(&cwq->delayed_works,
+	struct work_struct *work = list_first_entry(&pwq->delayed_works,
 						    struct work_struct, entry);
 
-	cwq_activate_delayed_work(work);
+	pwq_activate_delayed_work(work);
 }
 
 /**
- * cwq_dec_nr_in_flight - decrement cwq's nr_in_flight
- * @cwq: cwq of interest
+ * pwq_dec_nr_in_flight - decrement pwq's nr_in_flight
+ * @pwq: pwq of interest
  * @color: color of work which left the queue
  *
  * A work either has completed or is removed from pending queue,
- * decrement nr_in_flight of its cwq and handle workqueue flushing.
+ * decrement nr_in_flight of its pwq and handle workqueue flushing.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock).
+ * spin_lock_irq(pool->lock).
  */
-static void cwq_dec_nr_in_flight(struct cpu_workqueue_struct *cwq, int color)
+static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, int color)
 {
 	/* ignore uncolored works */
 	if (color == WORK_NO_COLOR)
 		return;
 
-	cwq->nr_in_flight[color]--;
+	pwq->nr_in_flight[color]--;
 
-	cwq->nr_active--;
-	if (!list_empty(&cwq->delayed_works)) {
+	pwq->nr_active--;
+	if (!list_empty(&pwq->delayed_works)) {
 		/* one down, submit a delayed one */
-		if (cwq->nr_active < cwq->max_active)
-			cwq_activate_first_delayed(cwq);
+		if (pwq->nr_active < pwq->max_active)
+			pwq_activate_first_delayed(pwq);
 	}
 
 	/* is flush in progress and are we at the flushing tip? */
-	if (likely(cwq->flush_color != color))
+	if (likely(pwq->flush_color != color))
 		return;
 
 	/* are there still in-flight works? */
-	if (cwq->nr_in_flight[color])
+	if (pwq->nr_in_flight[color])
 		return;
 
-	/* this cwq is done, clear flush_color */
-	cwq->flush_color = -1;
+	/* this pwq is done, clear flush_color */
+	pwq->flush_color = -1;
 
 	/*
-	 * If this was the last cwq, wake up the first flusher.  It
+	 * If this was the last pwq, wake up the first flusher.  It
 	 * will handle the rest.
 	 */
-	if (atomic_dec_and_test(&cwq->wq->nr_cwqs_to_flush))
-		complete(&cwq->wq->first_flusher->done);
+	if (atomic_dec_and_test(&pwq->wq->nr_pwqs_to_flush))
+		complete(&pwq->wq->first_flusher->done);
 }
 
 /**
@@ -1070,7 +1052,8 @@ static void cwq_dec_nr_in_flight(struct cpu_workqueue_struct *cwq, int color)
 static int try_to_grab_pending(struct work_struct *work, bool is_dwork,
 			       unsigned long *flags)
 {
-	struct global_cwq *gcwq;
+	struct worker_pool *pool;
+	struct pool_workqueue *pwq;
 
 	local_irq_save(*flags);
 
@@ -1095,41 +1078,43 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork,
 	 * The queueing is in progress, or it is already queued. Try to
 	 * steal it from ->worklist without clearing WORK_STRUCT_PENDING.
 	 */
-	gcwq = get_work_gcwq(work);
-	if (!gcwq)
+	pool = get_work_pool(work);
+	if (!pool)
 		goto fail;
 
-	spin_lock(&gcwq->lock);
-	if (!list_empty(&work->entry)) {
+	spin_lock(&pool->lock);
+	/*
+	 * work->data is guaranteed to point to pwq only while the work
+	 * item is queued on pwq->wq, and both updating work->data to point
+	 * to pwq on queueing and to pool on dequeueing are done under
+	 * pwq->pool->lock.  This in turn guarantees that, if work->data
+	 * points to pwq which is associated with a locked pool, the work
+	 * item is currently queued on that pool.
+	 */
+	pwq = get_work_pwq(work);
+	if (pwq && pwq->pool == pool) {
+		debug_work_deactivate(work);
+
 		/*
-		 * This work is queued, but perhaps we locked the wrong gcwq.
-		 * In that case we must see the new value after rmb(), see
-		 * insert_work()->wmb().
+		 * A delayed work item cannot be grabbed directly because
+		 * it might have linked NO_COLOR work items which, if left
+		 * on the delayed_list, will confuse pwq->nr_active
+		 * management later on and cause stall.  Make sure the work
+		 * item is activated before grabbing.
 		 */
-		smp_rmb();
-		if (gcwq == get_work_gcwq(work)) {
-			debug_work_deactivate(work);
+		if (*work_data_bits(work) & WORK_STRUCT_DELAYED)
+			pwq_activate_delayed_work(work);
 
-			/*
-			 * A delayed work item cannot be grabbed directly
-			 * because it might have linked NO_COLOR work items
-			 * which, if left on the delayed_list, will confuse
-			 * cwq->nr_active management later on and cause
-			 * stall.  Make sure the work item is activated
-			 * before grabbing.
-			 */
-			if (*work_data_bits(work) & WORK_STRUCT_DELAYED)
-				cwq_activate_delayed_work(work);
+		list_del_init(&work->entry);
+		pwq_dec_nr_in_flight(get_work_pwq(work), get_work_color(work));
 
-			list_del_init(&work->entry);
-			cwq_dec_nr_in_flight(get_work_cwq(work),
-				get_work_color(work));
+		/* work->data points to pwq iff queued, point to pool */
+		set_work_pool_and_keep_pending(work, pool->id);
 
-			spin_unlock(&gcwq->lock);
-			return 1;
-		}
+		spin_unlock(&pool->lock);
+		return 1;
 	}
-	spin_unlock(&gcwq->lock);
+	spin_unlock(&pool->lock);
 fail:
 	local_irq_restore(*flags);
 	if (work_is_canceling(work))
@@ -1139,33 +1124,25 @@ fail:
 }
 
 /**
- * insert_work - insert a work into gcwq
- * @cwq: cwq @work belongs to
+ * insert_work - insert a work into a pool
+ * @pwq: pwq @work belongs to
  * @work: work to insert
  * @head: insertion point
  * @extra_flags: extra WORK_STRUCT_* flags to set
  *
- * Insert @work which belongs to @cwq into @gcwq after @head.
- * @extra_flags is or'd to work_struct flags.
+ * Insert @work which belongs to @pwq after @head.  @extra_flags is or'd to
+ * work_struct flags.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock).
+ * spin_lock_irq(pool->lock).
  */
-static void insert_work(struct cpu_workqueue_struct *cwq,
-			struct work_struct *work, struct list_head *head,
-			unsigned int extra_flags)
+static void insert_work(struct pool_workqueue *pwq, struct work_struct *work,
+			struct list_head *head, unsigned int extra_flags)
 {
-	struct worker_pool *pool = cwq->pool;
+	struct worker_pool *pool = pwq->pool;
 
 	/* we own @work, set data and link */
-	set_work_cwq(work, cwq, extra_flags);
-
-	/*
-	 * Ensure that we get the right work->data if we see the
-	 * result of list_add() below, see try_to_grab_pending().
-	 */
-	smp_wmb();
-
+	set_work_pwq(work, pwq, extra_flags);
 	list_add_tail(&work->entry, head);
 
 	/*
@@ -1181,41 +1158,24 @@ static void insert_work(struct cpu_workqueue_struct *cwq,
 
 /*
  * Test whether @work is being queued from another work executing on the
- * same workqueue.  This is rather expensive and should only be used from
- * cold paths.
+ * same workqueue.
  */
 static bool is_chained_work(struct workqueue_struct *wq)
 {
-	unsigned long flags;
-	unsigned int cpu;
-
-	for_each_gcwq_cpu(cpu) {
-		struct global_cwq *gcwq = get_gcwq(cpu);
-		struct worker *worker;
-		struct hlist_node *pos;
-		int i;
+	struct worker *worker;
 
-		spin_lock_irqsave(&gcwq->lock, flags);
-		for_each_busy_worker(worker, i, pos, gcwq) {
-			if (worker->task != current)
-				continue;
-			spin_unlock_irqrestore(&gcwq->lock, flags);
-			/*
-			 * I'm @worker, no locking necessary.  See if @work
-			 * is headed to the same workqueue.
-			 */
-			return worker->current_cwq->wq == wq;
-		}
-		spin_unlock_irqrestore(&gcwq->lock, flags);
-	}
-	return false;
+	worker = current_wq_worker();
+	/*
+	 * Return %true iff I'm a worker execuing a work item on @wq.  If
+	 * I'm @worker, it's safe to dereference it without locking.
+	 */
+	return worker && worker->current_pwq->wq == wq;
 }
 
 static void __queue_work(unsigned int cpu, struct workqueue_struct *wq,
 			 struct work_struct *work)
 {
-	struct global_cwq *gcwq;
-	struct cpu_workqueue_struct *cwq;
+	struct pool_workqueue *pwq;
 	struct list_head *worklist;
 	unsigned int work_flags;
 	unsigned int req_cpu = cpu;
@@ -1235,9 +1195,9 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq,
 	    WARN_ON_ONCE(!is_chained_work(wq)))
 		return;
 
-	/* determine gcwq to use */
+	/* determine the pwq to use */
 	if (!(wq->flags & WQ_UNBOUND)) {
-		struct global_cwq *last_gcwq;
+		struct worker_pool *last_pool;
 
 		if (cpu == WORK_CPU_UNBOUND)
 			cpu = raw_smp_processor_id();
@@ -1248,55 +1208,54 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq,
 		 * work needs to be queued on that cpu to guarantee
 		 * non-reentrancy.
 		 */
-		gcwq = get_gcwq(cpu);
-		last_gcwq = get_work_gcwq(work);
+		pwq = get_pwq(cpu, wq);
+		last_pool = get_work_pool(work);
 
-		if (last_gcwq && last_gcwq != gcwq) {
+		if (last_pool && last_pool != pwq->pool) {
 			struct worker *worker;
 
-			spin_lock(&last_gcwq->lock);
+			spin_lock(&last_pool->lock);
 
-			worker = find_worker_executing_work(last_gcwq, work);
+			worker = find_worker_executing_work(last_pool, work);
 
-			if (worker && worker->current_cwq->wq == wq)
-				gcwq = last_gcwq;
-			else {
+			if (worker && worker->current_pwq->wq == wq) {
+				pwq = get_pwq(last_pool->cpu, wq);
+			} else {
 				/* meh... not running there, queue here */
-				spin_unlock(&last_gcwq->lock);
-				spin_lock(&gcwq->lock);
+				spin_unlock(&last_pool->lock);
+				spin_lock(&pwq->pool->lock);
 			}
 		} else {
-			spin_lock(&gcwq->lock);
+			spin_lock(&pwq->pool->lock);
 		}
 	} else {
-		gcwq = get_gcwq(WORK_CPU_UNBOUND);
-		spin_lock(&gcwq->lock);
+		pwq = get_pwq(WORK_CPU_UNBOUND, wq);
+		spin_lock(&pwq->pool->lock);
 	}
 
-	/* gcwq determined, get cwq and queue */
-	cwq = get_cwq(gcwq->cpu, wq);
-	trace_workqueue_queue_work(req_cpu, cwq, work);
+	/* pwq determined, queue */
+	trace_workqueue_queue_work(req_cpu, pwq, work);
 
 	if (WARN_ON(!list_empty(&work->entry))) {
-		spin_unlock(&gcwq->lock);
+		spin_unlock(&pwq->pool->lock);
 		return;
 	}
 
-	cwq->nr_in_flight[cwq->work_color]++;
-	work_flags = work_color_to_flags(cwq->work_color);
+	pwq->nr_in_flight[pwq->work_color]++;
+	work_flags = work_color_to_flags(pwq->work_color);
 
-	if (likely(cwq->nr_active < cwq->max_active)) {
+	if (likely(pwq->nr_active < pwq->max_active)) {
 		trace_workqueue_activate_work(work);
-		cwq->nr_active++;
-		worklist = &cwq->pool->worklist;
+		pwq->nr_active++;
+		worklist = &pwq->pool->worklist;
 	} else {
 		work_flags |= WORK_STRUCT_DELAYED;
-		worklist = &cwq->delayed_works;
+		worklist = &pwq->delayed_works;
 	}
 
-	insert_work(cwq, work, worklist, work_flags);
+	insert_work(pwq, work, worklist, work_flags);
 
-	spin_unlock(&gcwq->lock);
+	spin_unlock(&pwq->pool->lock);
 }
 
 /**
@@ -1347,19 +1306,17 @@ EXPORT_SYMBOL_GPL(queue_work);
 void delayed_work_timer_fn(unsigned long __data)
 {
 	struct delayed_work *dwork = (struct delayed_work *)__data;
-	struct cpu_workqueue_struct *cwq = get_work_cwq(&dwork->work);
 
 	/* should have been called from irqsafe timer with irq already off */
-	__queue_work(dwork->cpu, cwq->wq, &dwork->work);
+	__queue_work(dwork->cpu, dwork->wq, &dwork->work);
 }
-EXPORT_SYMBOL_GPL(delayed_work_timer_fn);
+EXPORT_SYMBOL(delayed_work_timer_fn);
 
 static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
 				struct delayed_work *dwork, unsigned long delay)
 {
 	struct timer_list *timer = &dwork->timer;
 	struct work_struct *work = &dwork->work;
-	unsigned int lcpu;
 
 	WARN_ON_ONCE(timer->function != delayed_work_timer_fn ||
 		     timer->data != (unsigned long)dwork);
@@ -1379,30 +1336,7 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
 
 	timer_stats_timer_set_start_info(&dwork->timer);
 
-	/*
-	 * This stores cwq for the moment, for the timer_fn.  Note that the
-	 * work's gcwq is preserved to allow reentrance detection for
-	 * delayed works.
-	 */
-	if (!(wq->flags & WQ_UNBOUND)) {
-		struct global_cwq *gcwq = get_work_gcwq(work);
-
-		/*
-		 * If we cannot get the last gcwq from @work directly,
-		 * select the last CPU such that it avoids unnecessarily
-		 * triggering non-reentrancy check in __queue_work().
-		 */
-		lcpu = cpu;
-		if (gcwq)
-			lcpu = gcwq->cpu;
-		if (lcpu == WORK_CPU_UNBOUND)
-			lcpu = raw_smp_processor_id();
-	} else {
-		lcpu = WORK_CPU_UNBOUND;
-	}
-
-	set_work_cwq(work, get_cwq(lcpu, wq), 0);
-
+	dwork->wq = wq;
 	dwork->cpu = cpu;
 	timer->expires = jiffies + delay;
 
@@ -1519,12 +1453,11 @@ EXPORT_SYMBOL_GPL(mod_delayed_work);
  * necessary.
  *
  * LOCKING:
- * spin_lock_irq(gcwq->lock).
+ * spin_lock_irq(pool->lock).
  */
 static void worker_enter_idle(struct worker *worker)
 {
 	struct worker_pool *pool = worker->pool;
-	struct global_cwq *gcwq = pool->gcwq;
 
 	BUG_ON(worker->flags & WORKER_IDLE);
 	BUG_ON(!list_empty(&worker->entry) &&
@@ -1542,14 +1475,14 @@ static void worker_enter_idle(struct worker *worker)
 		mod_timer(&pool->idle_timer, jiffies + IDLE_WORKER_TIMEOUT);
 
 	/*
-	 * Sanity check nr_running.  Because gcwq_unbind_fn() releases
-	 * gcwq->lock between setting %WORKER_UNBOUND and zapping
+	 * Sanity check nr_running.  Because wq_unbind_fn() releases
+	 * pool->lock between setting %WORKER_UNBOUND and zapping
 	 * nr_running, the warning may trigger spuriously.  Check iff
 	 * unbind is not in progress.
 	 */
-	WARN_ON_ONCE(!(gcwq->flags & GCWQ_DISASSOCIATED) &&
+	WARN_ON_ONCE(!(pool->flags & POOL_DISASSOCIATED) &&
 		     pool->nr_workers == pool->nr_idle &&
-		     atomic_read(get_pool_nr_running(pool)));
+		     atomic_read(&pool->nr_running));
 }
 
 /**
@@ -1559,7 +1492,7 @@ static void worker_enter_idle(struct worker *worker)
  * @worker is leaving idle state.  Update stats.
  *
  * LOCKING:
- * spin_lock_irq(gcwq->lock).
+ * spin_lock_irq(pool->lock).
  */
 static void worker_leave_idle(struct worker *worker)
 {
@@ -1572,7 +1505,7 @@ static void worker_leave_idle(struct worker *worker)
 }
 
 /**
- * worker_maybe_bind_and_lock - bind worker to its cpu if possible and lock gcwq
+ * worker_maybe_bind_and_lock - bind worker to its cpu if possible and lock pool
  * @worker: self
  *
  * Works which are scheduled while the cpu is online must at least be
@@ -1584,27 +1517,27 @@ static void worker_leave_idle(struct worker *worker)
  * themselves to the target cpu and may race with cpu going down or
  * coming online.  kthread_bind() can't be used because it may put the
  * worker to already dead cpu and set_cpus_allowed_ptr() can't be used
- * verbatim as it's best effort and blocking and gcwq may be
+ * verbatim as it's best effort and blocking and pool may be
  * [dis]associated in the meantime.
  *
- * This function tries set_cpus_allowed() and locks gcwq and verifies the
- * binding against %GCWQ_DISASSOCIATED which is set during
+ * This function tries set_cpus_allowed() and locks pool and verifies the
+ * binding against %POOL_DISASSOCIATED which is set during
  * %CPU_DOWN_PREPARE and cleared during %CPU_ONLINE, so if the worker
  * enters idle state or fetches works without dropping lock, it can
  * guarantee the scheduling requirement described in the first paragraph.
  *
  * CONTEXT:
- * Might sleep.  Called without any lock but returns with gcwq->lock
+ * Might sleep.  Called without any lock but returns with pool->lock
  * held.
  *
  * RETURNS:
- * %true if the associated gcwq is online (@worker is successfully
+ * %true if the associated pool is online (@worker is successfully
  * bound), %false if offline.
  */
 static bool worker_maybe_bind_and_lock(struct worker *worker)
-__acquires(&gcwq->lock)
+__acquires(&pool->lock)
 {
-	struct global_cwq *gcwq = worker->pool->gcwq;
+	struct worker_pool *pool = worker->pool;
 	struct task_struct *task = worker->task;
 
 	while (true) {
@@ -1612,19 +1545,19 @@ __acquires(&gcwq->lock)
 		 * The following call may fail, succeed or succeed
 		 * without actually migrating the task to the cpu if
 		 * it races with cpu hotunplug operation.  Verify
-		 * against GCWQ_DISASSOCIATED.
+		 * against POOL_DISASSOCIATED.
 		 */
-		if (!(gcwq->flags & GCWQ_DISASSOCIATED))
-			set_cpus_allowed_ptr(task, get_cpu_mask(gcwq->cpu));
+		if (!(pool->flags & POOL_DISASSOCIATED))
+			set_cpus_allowed_ptr(task, get_cpu_mask(pool->cpu));
 
-		spin_lock_irq(&gcwq->lock);
-		if (gcwq->flags & GCWQ_DISASSOCIATED)
+		spin_lock_irq(&pool->lock);
+		if (pool->flags & POOL_DISASSOCIATED)
 			return false;
-		if (task_cpu(task) == gcwq->cpu &&
+		if (task_cpu(task) == pool->cpu &&
 		    cpumask_equal(&current->cpus_allowed,
-				  get_cpu_mask(gcwq->cpu)))
+				  get_cpu_mask(pool->cpu)))
 			return true;
-		spin_unlock_irq(&gcwq->lock);
+		spin_unlock_irq(&pool->lock);
 
 		/*
 		 * We've raced with CPU hot[un]plug.  Give it a breather
@@ -1643,15 +1576,13 @@ __acquires(&gcwq->lock)
  */
 static void idle_worker_rebind(struct worker *worker)
 {
-	struct global_cwq *gcwq = worker->pool->gcwq;
-
 	/* CPU may go down again inbetween, clear UNBOUND only on success */
 	if (worker_maybe_bind_and_lock(worker))
 		worker_clr_flags(worker, WORKER_UNBOUND);
 
 	/* rebind complete, become available again */
 	list_add(&worker->entry, &worker->pool->idle_list);
-	spin_unlock_irq(&gcwq->lock);
+	spin_unlock_irq(&worker->pool->lock);
 }
 
 /*
@@ -1663,19 +1594,18 @@ static void idle_worker_rebind(struct worker *worker)
 static void busy_worker_rebind_fn(struct work_struct *work)
 {
 	struct worker *worker = container_of(work, struct worker, rebind_work);
-	struct global_cwq *gcwq = worker->pool->gcwq;
 
 	if (worker_maybe_bind_and_lock(worker))
 		worker_clr_flags(worker, WORKER_UNBOUND);
 
-	spin_unlock_irq(&gcwq->lock);
+	spin_unlock_irq(&worker->pool->lock);
 }
 
 /**
- * rebind_workers - rebind all workers of a gcwq to the associated CPU
- * @gcwq: gcwq of interest
+ * rebind_workers - rebind all workers of a pool to the associated CPU
+ * @pool: pool of interest
  *
- * @gcwq->cpu is coming online.  Rebind all workers to the CPU.  Rebinding
+ * @pool->cpu is coming online.  Rebind all workers to the CPU.  Rebinding
  * is different for idle and busy ones.
  *
  * Idle ones will be removed from the idle_list and woken up.  They will
@@ -1693,38 +1623,31 @@ static void busy_worker_rebind_fn(struct work_struct *work)
  * including the manager will not appear on @idle_list until rebind is
  * complete, making local wake-ups safe.
  */
-static void rebind_workers(struct global_cwq *gcwq)
+static void rebind_workers(struct worker_pool *pool)
 {
-	struct worker_pool *pool;
 	struct worker *worker, *n;
-	struct hlist_node *pos;
 	int i;
 
-	lockdep_assert_held(&gcwq->lock);
-
-	for_each_worker_pool(pool, gcwq)
-		lockdep_assert_held(&pool->assoc_mutex);
+	lockdep_assert_held(&pool->assoc_mutex);
+	lockdep_assert_held(&pool->lock);
 
 	/* dequeue and kick idle ones */
-	for_each_worker_pool(pool, gcwq) {
-		list_for_each_entry_safe(worker, n, &pool->idle_list, entry) {
-			/*
-			 * idle workers should be off @pool->idle_list
-			 * until rebind is complete to avoid receiving
-			 * premature local wake-ups.
-			 */
-			list_del_init(&worker->entry);
+	list_for_each_entry_safe(worker, n, &pool->idle_list, entry) {
+		/*
+		 * idle workers should be off @pool->idle_list until rebind
+		 * is complete to avoid receiving premature local wake-ups.
+		 */
+		list_del_init(&worker->entry);
 
-			/*
-			 * worker_thread() will see the above dequeuing
-			 * and call idle_worker_rebind().
-			 */
-			wake_up_process(worker->task);
-		}
+		/*
+		 * worker_thread() will see the above dequeuing and call
+		 * idle_worker_rebind().
+		 */
+		wake_up_process(worker->task);
 	}
 
 	/* rebind busy workers */
-	for_each_busy_worker(worker, i, pos, gcwq) {
+	for_each_busy_worker(worker, i, pool) {
 		struct work_struct *rebind_work = &worker->rebind_work;
 		struct workqueue_struct *wq;
 
@@ -1736,16 +1659,16 @@ static void rebind_workers(struct global_cwq *gcwq)
 
 		/*
 		 * wq doesn't really matter but let's keep @worker->pool
-		 * and @cwq->pool consistent for sanity.
+		 * and @pwq->pool consistent for sanity.
 		 */
-		if (worker_pool_pri(worker->pool))
+		if (std_worker_pool_pri(worker->pool))
 			wq = system_highpri_wq;
 		else
 			wq = system_wq;
 
-		insert_work(get_cwq(gcwq->cpu, wq), rebind_work,
-			worker->scheduled.next,
-			work_color_to_flags(WORK_NO_COLOR));
+		insert_work(get_pwq(pool->cpu, wq), rebind_work,
+			    worker->scheduled.next,
+			    work_color_to_flags(WORK_NO_COLOR));
 	}
 }
 
@@ -1780,19 +1703,18 @@ static struct worker *alloc_worker(void)
  */
 static struct worker *create_worker(struct worker_pool *pool)
 {
-	struct global_cwq *gcwq = pool->gcwq;
-	const char *pri = worker_pool_pri(pool) ? "H" : "";
+	const char *pri = std_worker_pool_pri(pool) ? "H" : "";
 	struct worker *worker = NULL;
 	int id = -1;
 
-	spin_lock_irq(&gcwq->lock);
+	spin_lock_irq(&pool->lock);
 	while (ida_get_new(&pool->worker_ida, &id)) {
-		spin_unlock_irq(&gcwq->lock);
+		spin_unlock_irq(&pool->lock);
 		if (!ida_pre_get(&pool->worker_ida, GFP_KERNEL))
 			goto fail;
-		spin_lock_irq(&gcwq->lock);
+		spin_lock_irq(&pool->lock);
 	}
-	spin_unlock_irq(&gcwq->lock);
+	spin_unlock_irq(&pool->lock);
 
 	worker = alloc_worker();
 	if (!worker)
@@ -1801,30 +1723,30 @@ static struct worker *create_worker(struct worker_pool *pool)
 	worker->pool = pool;
 	worker->id = id;
 
-	if (gcwq->cpu != WORK_CPU_UNBOUND)
+	if (pool->cpu != WORK_CPU_UNBOUND)
 		worker->task = kthread_create_on_node(worker_thread,
-					worker, cpu_to_node(gcwq->cpu),
-					"kworker/%u:%d%s", gcwq->cpu, id, pri);
+					worker, cpu_to_node(pool->cpu),
+					"kworker/%u:%d%s", pool->cpu, id, pri);
 	else
 		worker->task = kthread_create(worker_thread, worker,
 					      "kworker/u:%d%s", id, pri);
 	if (IS_ERR(worker->task))
 		goto fail;
 
-	if (worker_pool_pri(pool))
+	if (std_worker_pool_pri(pool))
 		set_user_nice(worker->task, HIGHPRI_NICE_LEVEL);
 
 	/*
 	 * Determine CPU binding of the new worker depending on
-	 * %GCWQ_DISASSOCIATED.  The caller is responsible for ensuring the
+	 * %POOL_DISASSOCIATED.  The caller is responsible for ensuring the
 	 * flag remains stable across this function.  See the comments
 	 * above the flag definition for details.
 	 *
 	 * As an unbound worker may later become a regular one if CPU comes
 	 * online, make sure every worker has %PF_THREAD_BOUND set.
 	 */
-	if (!(gcwq->flags & GCWQ_DISASSOCIATED)) {
-		kthread_bind(worker->task, gcwq->cpu);
+	if (!(pool->flags & POOL_DISASSOCIATED)) {
+		kthread_bind(worker->task, pool->cpu);
 	} else {
 		worker->task->flags |= PF_THREAD_BOUND;
 		worker->flags |= WORKER_UNBOUND;
@@ -1833,9 +1755,9 @@ static struct worker *create_worker(struct worker_pool *pool)
 	return worker;
 fail:
 	if (id >= 0) {
-		spin_lock_irq(&gcwq->lock);
+		spin_lock_irq(&pool->lock);
 		ida_remove(&pool->worker_ida, id);
-		spin_unlock_irq(&gcwq->lock);
+		spin_unlock_irq(&pool->lock);
 	}
 	kfree(worker);
 	return NULL;
@@ -1845,10 +1767,10 @@ fail:
  * start_worker - start a newly created worker
  * @worker: worker to start
  *
- * Make the gcwq aware of @worker and start it.
+ * Make the pool aware of @worker and start it.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock).
+ * spin_lock_irq(pool->lock).
  */
 static void start_worker(struct worker *worker)
 {
@@ -1862,15 +1784,14 @@ static void start_worker(struct worker *worker)
  * destroy_worker - destroy a workqueue worker
  * @worker: worker to be destroyed
  *
- * Destroy @worker and adjust @gcwq stats accordingly.
+ * Destroy @worker and adjust @pool stats accordingly.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock) which is released and regrabbed.
+ * spin_lock_irq(pool->lock) which is released and regrabbed.
  */
 static void destroy_worker(struct worker *worker)
 {
 	struct worker_pool *pool = worker->pool;
-	struct global_cwq *gcwq = pool->gcwq;
 	int id = worker->id;
 
 	/* sanity check frenzy */
@@ -1885,21 +1806,20 @@ static void destroy_worker(struct worker *worker)
 	list_del_init(&worker->entry);
 	worker->flags |= WORKER_DIE;
 
-	spin_unlock_irq(&gcwq->lock);
+	spin_unlock_irq(&pool->lock);
 
 	kthread_stop(worker->task);
 	kfree(worker);
 
-	spin_lock_irq(&gcwq->lock);
+	spin_lock_irq(&pool->lock);
 	ida_remove(&pool->worker_ida, id);
 }
 
 static void idle_worker_timeout(unsigned long __pool)
 {
 	struct worker_pool *pool = (void *)__pool;
-	struct global_cwq *gcwq = pool->gcwq;
 
-	spin_lock_irq(&gcwq->lock);
+	spin_lock_irq(&pool->lock);
 
 	if (too_many_workers(pool)) {
 		struct worker *worker;
@@ -1918,20 +1838,20 @@ static void idle_worker_timeout(unsigned long __pool)
 		}
 	}
 
-	spin_unlock_irq(&gcwq->lock);
+	spin_unlock_irq(&pool->lock);
 }
 
 static bool send_mayday(struct work_struct *work)
 {
-	struct cpu_workqueue_struct *cwq = get_work_cwq(work);
-	struct workqueue_struct *wq = cwq->wq;
+	struct pool_workqueue *pwq = get_work_pwq(work);
+	struct workqueue_struct *wq = pwq->wq;
 	unsigned int cpu;
 
 	if (!(wq->flags & WQ_RESCUER))
 		return false;
 
 	/* mayday mayday mayday */
-	cpu = cwq->pool->gcwq->cpu;
+	cpu = pwq->pool->cpu;
 	/* WORK_CPU_UNBOUND can't be set in cpumask, use cpu 0 instead */
 	if (cpu == WORK_CPU_UNBOUND)
 		cpu = 0;
@@ -1940,13 +1860,12 @@ static bool send_mayday(struct work_struct *work)
 	return true;
 }
 
-static void gcwq_mayday_timeout(unsigned long __pool)
+static void pool_mayday_timeout(unsigned long __pool)
 {
 	struct worker_pool *pool = (void *)__pool;
-	struct global_cwq *gcwq = pool->gcwq;
 	struct work_struct *work;
 
-	spin_lock_irq(&gcwq->lock);
+	spin_lock_irq(&pool->lock);
 
 	if (need_to_create_worker(pool)) {
 		/*
@@ -1959,7 +1878,7 @@ static void gcwq_mayday_timeout(unsigned long __pool)
 			send_mayday(work);
 	}
 
-	spin_unlock_irq(&gcwq->lock);
+	spin_unlock_irq(&pool->lock);
 
 	mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INTERVAL);
 }
@@ -1978,24 +1897,22 @@ static void gcwq_mayday_timeout(unsigned long __pool)
  * may_start_working() true.
  *
  * LOCKING:
- * spin_lock_irq(gcwq->lock) which may be released and regrabbed
+ * spin_lock_irq(pool->lock) which may be released and regrabbed
  * multiple times.  Does GFP_KERNEL allocations.  Called only from
  * manager.
  *
  * RETURNS:
- * false if no action was taken and gcwq->lock stayed locked, true
+ * false if no action was taken and pool->lock stayed locked, true
  * otherwise.
  */
 static bool maybe_create_worker(struct worker_pool *pool)
-__releases(&gcwq->lock)
-__acquires(&gcwq->lock)
+__releases(&pool->lock)
+__acquires(&pool->lock)
 {
-	struct global_cwq *gcwq = pool->gcwq;
-
 	if (!need_to_create_worker(pool))
 		return false;
 restart:
-	spin_unlock_irq(&gcwq->lock);
+	spin_unlock_irq(&pool->lock);
 
 	/* if we don't make progress in MAYDAY_INITIAL_TIMEOUT, call for help */
 	mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INITIAL_TIMEOUT);
@@ -2006,7 +1923,7 @@ restart:
 		worker = create_worker(pool);
 		if (worker) {
 			del_timer_sync(&pool->mayday_timer);
-			spin_lock_irq(&gcwq->lock);
+			spin_lock_irq(&pool->lock);
 			start_worker(worker);
 			BUG_ON(need_to_create_worker(pool));
 			return true;
@@ -2023,7 +1940,7 @@ restart:
 	}
 
 	del_timer_sync(&pool->mayday_timer);
-	spin_lock_irq(&gcwq->lock);
+	spin_lock_irq(&pool->lock);
 	if (need_to_create_worker(pool))
 		goto restart;
 	return true;
@@ -2037,11 +1954,11 @@ restart:
  * IDLE_WORKER_TIMEOUT.
  *
  * LOCKING:
- * spin_lock_irq(gcwq->lock) which may be released and regrabbed
+ * spin_lock_irq(pool->lock) which may be released and regrabbed
  * multiple times.  Called only from manager.
  *
  * RETURNS:
- * false if no action was taken and gcwq->lock stayed locked, true
+ * false if no action was taken and pool->lock stayed locked, true
  * otherwise.
  */
 static bool maybe_destroy_workers(struct worker_pool *pool)
@@ -2071,21 +1988,21 @@ static bool maybe_destroy_workers(struct worker_pool *pool)
  * manage_workers - manage worker pool
  * @worker: self
  *
- * Assume the manager role and manage gcwq worker pool @worker belongs
+ * Assume the manager role and manage the worker pool @worker belongs
  * to.  At any given time, there can be only zero or one manager per
- * gcwq.  The exclusion is handled automatically by this function.
+ * pool.  The exclusion is handled automatically by this function.
  *
  * The caller can safely start processing works on false return.  On
  * true return, it's guaranteed that need_to_create_worker() is false
  * and may_start_working() is true.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock) which may be released and regrabbed
+ * spin_lock_irq(pool->lock) which may be released and regrabbed
  * multiple times.  Does GFP_KERNEL allocations.
  *
  * RETURNS:
- * false if no action was taken and gcwq->lock stayed locked, true if
- * some action was taken.
+ * spin_lock_irq(pool->lock) which may be released and regrabbed
+ * multiple times.  Does GFP_KERNEL allocations.
  */
 static bool manage_workers(struct worker *worker)
 {
@@ -2107,20 +2024,20 @@ static bool manage_workers(struct worker *worker)
 	 * manager against CPU hotplug.
 	 *
 	 * assoc_mutex would always be free unless CPU hotplug is in
-	 * progress.  trylock first without dropping @gcwq->lock.
+	 * progress.  trylock first without dropping @pool->lock.
 	 */
 	if (unlikely(!mutex_trylock(&pool->assoc_mutex))) {
-		spin_unlock_irq(&pool->gcwq->lock);
+		spin_unlock_irq(&pool->lock);
 		mutex_lock(&pool->assoc_mutex);
 		/*
 		 * CPU hotplug could have happened while we were waiting
 		 * for assoc_mutex.  Hotplug itself can't handle us
 		 * because manager isn't either on idle or busy list, and
-		 * @gcwq's state and ours could have deviated.
+		 * @pool's state and ours could have deviated.
 		 *
 		 * As hotplug is now excluded via assoc_mutex, we can
 		 * simply try to bind.  It will succeed or fail depending
-		 * on @gcwq's current state.  Try it and adjust
+		 * on @pool's current state.  Try it and adjust
 		 * %WORKER_UNBOUND accordingly.
 		 */
 		if (worker_maybe_bind_and_lock(worker))
@@ -2157,18 +2074,15 @@ static bool manage_workers(struct worker *worker)
  * call this function to process a work.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock) which is released and regrabbed.
+ * spin_lock_irq(pool->lock) which is released and regrabbed.
  */
 static void process_one_work(struct worker *worker, struct work_struct *work)
-__releases(&gcwq->lock)
-__acquires(&gcwq->lock)
+__releases(&pool->lock)
+__acquires(&pool->lock)
 {
-	struct cpu_workqueue_struct *cwq = get_work_cwq(work);
+	struct pool_workqueue *pwq = get_work_pwq(work);
 	struct worker_pool *pool = worker->pool;
-	struct global_cwq *gcwq = pool->gcwq;
-	struct hlist_head *bwh = busy_worker_head(gcwq, work);
-	bool cpu_intensive = cwq->wq->flags & WQ_CPU_INTENSIVE;
-	work_func_t f = work->func;
+	bool cpu_intensive = pwq->wq->flags & WQ_CPU_INTENSIVE;
 	int work_color;
 	struct worker *collision;
 #ifdef CONFIG_LOCKDEP
@@ -2186,11 +2100,11 @@ __acquires(&gcwq->lock)
 	/*
 	 * Ensure we're on the correct CPU.  DISASSOCIATED test is
 	 * necessary to avoid spurious warnings from rescuers servicing the
-	 * unbound or a disassociated gcwq.
+	 * unbound or a disassociated pool.
 	 */
 	WARN_ON_ONCE(!(worker->flags & WORKER_UNBOUND) &&
-		     !(gcwq->flags & GCWQ_DISASSOCIATED) &&
-		     raw_smp_processor_id() != gcwq->cpu);
+		     !(pool->flags & POOL_DISASSOCIATED) &&
+		     raw_smp_processor_id() != pool->cpu);
 
 	/*
 	 * A single work shouldn't be executed concurrently by
@@ -2198,7 +2112,7 @@ __acquires(&gcwq->lock)
 	 * already processing the work.  If so, defer the work to the
 	 * currently executing one.
 	 */
-	collision = __find_worker_executing_work(gcwq, bwh, work);
+	collision = find_worker_executing_work(pool, work);
 	if (unlikely(collision)) {
 		move_linked_works(work, &collision->scheduled, NULL);
 		return;
@@ -2206,9 +2120,10 @@ __acquires(&gcwq->lock)
 
 	/* claim and dequeue */
 	debug_work_deactivate(work);
-	hlist_add_head(&worker->hentry, bwh);
+	hash_add(pool->busy_hash, &worker->hentry, (unsigned long)work);
 	worker->current_work = work;
-	worker->current_cwq = cwq;
+	worker->current_func = work->func;
+	worker->current_pwq = pwq;
 	work_color = get_work_color(work);
 
 	list_del_init(&work->entry);
@@ -2221,53 +2136,55 @@ __acquires(&gcwq->lock)
 		worker_set_flags(worker, WORKER_CPU_INTENSIVE, true);
 
 	/*
-	 * Unbound gcwq isn't concurrency managed and work items should be
+	 * Unbound pool isn't concurrency managed and work items should be
 	 * executed ASAP.  Wake up another worker if necessary.
 	 */
 	if ((worker->flags & WORKER_UNBOUND) && need_more_worker(pool))
 		wake_up_worker(pool);
 
 	/*
-	 * Record the last CPU and clear PENDING which should be the last
-	 * update to @work.  Also, do this inside @gcwq->lock so that
+	 * Record the last pool and clear PENDING which should be the last
+	 * update to @work.  Also, do this inside @pool->lock so that
 	 * PENDING and queued state changes happen together while IRQ is
 	 * disabled.
 	 */
-	set_work_cpu_and_clear_pending(work, gcwq->cpu);
+	set_work_pool_and_clear_pending(work, pool->id);
 
-	spin_unlock_irq(&gcwq->lock);
+	spin_unlock_irq(&pool->lock);
 
-	lock_map_acquire_read(&cwq->wq->lockdep_map);
+	lock_map_acquire_read(&pwq->wq->lockdep_map);
 	lock_map_acquire(&lockdep_map);
 	trace_workqueue_execute_start(work);
-	f(work);
+	worker->current_func(work);
 	/*
 	 * While we must be careful to not use "work" after this, the trace
 	 * point will only record its address.
 	 */
 	trace_workqueue_execute_end(work);
 	lock_map_release(&lockdep_map);
-	lock_map_release(&cwq->wq->lockdep_map);
+	lock_map_release(&pwq->wq->lockdep_map);
 
 	if (unlikely(in_atomic() || lockdep_depth(current) > 0)) {
 		pr_err("BUG: workqueue leaked lock or atomic: %s/0x%08x/%d\n"
 		       "     last function: %pf\n",
-		       current->comm, preempt_count(), task_pid_nr(current), f);
+		       current->comm, preempt_count(), task_pid_nr(current),
+		       worker->current_func);
 		debug_show_held_locks(current);
 		dump_stack();
 	}
 
-	spin_lock_irq(&gcwq->lock);
+	spin_lock_irq(&pool->lock);
 
 	/* clear cpu intensive status */
 	if (unlikely(cpu_intensive))
 		worker_clr_flags(worker, WORKER_CPU_INTENSIVE);
 
 	/* we're done with it, release */
-	hlist_del_init(&worker->hentry);
+	hash_del(&worker->hentry);
 	worker->current_work = NULL;
-	worker->current_cwq = NULL;
-	cwq_dec_nr_in_flight(cwq, work_color);
+	worker->current_func = NULL;
+	worker->current_pwq = NULL;
+	pwq_dec_nr_in_flight(pwq, work_color);
 }
 
 /**
@@ -2279,7 +2196,7 @@ __acquires(&gcwq->lock)
  * fetches a work from the top and executes it.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock) which may be released and regrabbed
+ * spin_lock_irq(pool->lock) which may be released and regrabbed
  * multiple times.
  */
 static void process_scheduled_works(struct worker *worker)
@@ -2295,8 +2212,8 @@ static void process_scheduled_works(struct worker *worker)
  * worker_thread - the worker thread function
  * @__worker: self
  *
- * The gcwq worker thread function.  There's a single dynamic pool of
- * these per each cpu.  These workers process all works regardless of
+ * The worker thread function.  There are NR_CPU_WORKER_POOLS dynamic pools
+ * of these per each cpu.  These workers process all works regardless of
  * their specific target workqueue.  The only exception is works which
  * belong to workqueues with a rescuer which will be explained in
  * rescuer_thread().
@@ -2305,16 +2222,15 @@ static int worker_thread(void *__worker)
 {
 	struct worker *worker = __worker;
 	struct worker_pool *pool = worker->pool;
-	struct global_cwq *gcwq = pool->gcwq;
 
 	/* tell the scheduler that this is a workqueue worker */
 	worker->task->flags |= PF_WQ_WORKER;
 woke_up:
-	spin_lock_irq(&gcwq->lock);
+	spin_lock_irq(&pool->lock);
 
 	/* we are off idle list if destruction or rebind is requested */
 	if (unlikely(list_empty(&worker->entry))) {
-		spin_unlock_irq(&gcwq->lock);
+		spin_unlock_irq(&pool->lock);
 
 		/* if DIE is set, destruction is requested */
 		if (worker->flags & WORKER_DIE) {
@@ -2373,52 +2289,59 @@ sleep:
 		goto recheck;
 
 	/*
-	 * gcwq->lock is held and there's no work to process and no
-	 * need to manage, sleep.  Workers are woken up only while
-	 * holding gcwq->lock or from local cpu, so setting the
-	 * current state before releasing gcwq->lock is enough to
-	 * prevent losing any event.
+	 * pool->lock is held and there's no work to process and no need to
+	 * manage, sleep.  Workers are woken up only while holding
+	 * pool->lock or from local cpu, so setting the current state
+	 * before releasing pool->lock is enough to prevent losing any
+	 * event.
 	 */
 	worker_enter_idle(worker);
 	__set_current_state(TASK_INTERRUPTIBLE);
-	spin_unlock_irq(&gcwq->lock);
+	spin_unlock_irq(&pool->lock);
 	schedule();
 	goto woke_up;
 }
 
 /**
  * rescuer_thread - the rescuer thread function
- * @__wq: the associated workqueue
+ * @__rescuer: self
  *
  * Workqueue rescuer thread function.  There's one rescuer for each
  * workqueue which has WQ_RESCUER set.
  *
- * Regular work processing on a gcwq may block trying to create a new
+ * Regular work processing on a pool may block trying to create a new
  * worker which uses GFP_KERNEL allocation which has slight chance of
  * developing into deadlock if some works currently on the same queue
  * need to be processed to satisfy the GFP_KERNEL allocation.  This is
  * the problem rescuer solves.
  *
- * When such condition is possible, the gcwq summons rescuers of all
- * workqueues which have works queued on the gcwq and let them process
+ * When such condition is possible, the pool summons rescuers of all
+ * workqueues which have works queued on the pool and let them process
  * those works so that forward progress can be guaranteed.
  *
  * This should happen rarely.
  */
-static int rescuer_thread(void *__wq)
+static int rescuer_thread(void *__rescuer)
 {
-	struct workqueue_struct *wq = __wq;
-	struct worker *rescuer = wq->rescuer;
+	struct worker *rescuer = __rescuer;
+	struct workqueue_struct *wq = rescuer->rescue_wq;
 	struct list_head *scheduled = &rescuer->scheduled;
 	bool is_unbound = wq->flags & WQ_UNBOUND;
 	unsigned int cpu;
 
 	set_user_nice(current, RESCUER_NICE_LEVEL);
+
+	/*
+	 * Mark rescuer as worker too.  As WORKER_PREP is never cleared, it
+	 * doesn't participate in concurrency management.
+	 */
+	rescuer->task->flags |= PF_WQ_WORKER;
 repeat:
 	set_current_state(TASK_INTERRUPTIBLE);
 
 	if (kthread_should_stop()) {
 		__set_current_state(TASK_RUNNING);
+		rescuer->task->flags &= ~PF_WQ_WORKER;
 		return 0;
 	}
 
@@ -2428,9 +2351,8 @@ repeat:
 	 */
 	for_each_mayday_cpu(cpu, wq->mayday_mask) {
 		unsigned int tcpu = is_unbound ? WORK_CPU_UNBOUND : cpu;
-		struct cpu_workqueue_struct *cwq = get_cwq(tcpu, wq);
-		struct worker_pool *pool = cwq->pool;
-		struct global_cwq *gcwq = pool->gcwq;
+		struct pool_workqueue *pwq = get_pwq(tcpu, wq);
+		struct worker_pool *pool = pwq->pool;
 		struct work_struct *work, *n;
 
 		__set_current_state(TASK_RUNNING);
@@ -2446,22 +2368,24 @@ repeat:
 		 */
 		BUG_ON(!list_empty(&rescuer->scheduled));
 		list_for_each_entry_safe(work, n, &pool->worklist, entry)
-			if (get_work_cwq(work) == cwq)
+			if (get_work_pwq(work) == pwq)
 				move_linked_works(work, scheduled, &n);
 
 		process_scheduled_works(rescuer);
 
 		/*
-		 * Leave this gcwq.  If keep_working() is %true, notify a
+		 * Leave this pool.  If keep_working() is %true, notify a
 		 * regular worker; otherwise, we end up with 0 concurrency
 		 * and stalling the execution.
 		 */
 		if (keep_working(pool))
 			wake_up_worker(pool);
 
-		spin_unlock_irq(&gcwq->lock);
+		spin_unlock_irq(&pool->lock);
 	}
 
+	/* rescuers should never participate in concurrency management */
+	WARN_ON_ONCE(!(rescuer->flags & WORKER_NOT_RUNNING));
 	schedule();
 	goto repeat;
 }
@@ -2479,7 +2403,7 @@ static void wq_barrier_func(struct work_struct *work)
 
 /**
  * insert_wq_barrier - insert a barrier work
- * @cwq: cwq to insert barrier into
+ * @pwq: pwq to insert barrier into
  * @barr: wq_barrier to insert
  * @target: target work to attach @barr to
  * @worker: worker currently executing @target, NULL if @target is not executing
@@ -2496,12 +2420,12 @@ static void wq_barrier_func(struct work_struct *work)
  * after a work with LINKED flag set.
  *
  * Note that when @worker is non-NULL, @target may be modified
- * underneath us, so we can't reliably determine cwq from @target.
+ * underneath us, so we can't reliably determine pwq from @target.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock).
+ * spin_lock_irq(pool->lock).
  */
-static void insert_wq_barrier(struct cpu_workqueue_struct *cwq,
+static void insert_wq_barrier(struct pool_workqueue *pwq,
 			      struct wq_barrier *barr,
 			      struct work_struct *target, struct worker *worker)
 {
@@ -2509,7 +2433,7 @@ static void insert_wq_barrier(struct cpu_workqueue_struct *cwq,
 	unsigned int linked = 0;
 
 	/*
-	 * debugobject calls are safe here even with gcwq->lock locked
+	 * debugobject calls are safe here even with pool->lock locked
 	 * as we know for sure that this will not trigger any of the
 	 * checks and call back into the fixup functions where we
 	 * might deadlock.
@@ -2534,23 +2458,23 @@ static void insert_wq_barrier(struct cpu_workqueue_struct *cwq,
 	}
 
 	debug_work_activate(&barr->work);
-	insert_work(cwq, &barr->work, head,
+	insert_work(pwq, &barr->work, head,
 		    work_color_to_flags(WORK_NO_COLOR) | linked);
 }
 
 /**
- * flush_workqueue_prep_cwqs - prepare cwqs for workqueue flushing
+ * flush_workqueue_prep_pwqs - prepare pwqs for workqueue flushing
  * @wq: workqueue being flushed
  * @flush_color: new flush color, < 0 for no-op
  * @work_color: new work color, < 0 for no-op
  *
- * Prepare cwqs for workqueue flushing.
+ * Prepare pwqs for workqueue flushing.
  *
- * If @flush_color is non-negative, flush_color on all cwqs should be
- * -1.  If no cwq has in-flight commands at the specified color, all
- * cwq->flush_color's stay at -1 and %false is returned.  If any cwq
- * has in flight commands, its cwq->flush_color is set to
- * @flush_color, @wq->nr_cwqs_to_flush is updated accordingly, cwq
+ * If @flush_color is non-negative, flush_color on all pwqs should be
+ * -1.  If no pwq has in-flight commands at the specified color, all
+ * pwq->flush_color's stay at -1 and %false is returned.  If any pwq
+ * has in flight commands, its pwq->flush_color is set to
+ * @flush_color, @wq->nr_pwqs_to_flush is updated accordingly, pwq
  * wakeup logic is armed and %true is returned.
  *
  * The caller should have initialized @wq->first_flusher prior to
@@ -2558,7 +2482,7 @@ static void insert_wq_barrier(struct cpu_workqueue_struct *cwq,
  * @flush_color is negative, no flush color update is done and %false
  * is returned.
  *
- * If @work_color is non-negative, all cwqs should have the same
+ * If @work_color is non-negative, all pwqs should have the same
  * work_color which is previous to @work_color and all will be
  * advanced to @work_color.
  *
@@ -2569,42 +2493,42 @@ static void insert_wq_barrier(struct cpu_workqueue_struct *cwq,
  * %true if @flush_color >= 0 and there's something to flush.  %false
  * otherwise.
  */
-static bool flush_workqueue_prep_cwqs(struct workqueue_struct *wq,
+static bool flush_workqueue_prep_pwqs(struct workqueue_struct *wq,
 				      int flush_color, int work_color)
 {
 	bool wait = false;
 	unsigned int cpu;
 
 	if (flush_color >= 0) {
-		BUG_ON(atomic_read(&wq->nr_cwqs_to_flush));
-		atomic_set(&wq->nr_cwqs_to_flush, 1);
+		BUG_ON(atomic_read(&wq->nr_pwqs_to_flush));
+		atomic_set(&wq->nr_pwqs_to_flush, 1);
 	}
 
-	for_each_cwq_cpu(cpu, wq) {
-		struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
-		struct global_cwq *gcwq = cwq->pool->gcwq;
+	for_each_pwq_cpu(cpu, wq) {
+		struct pool_workqueue *pwq = get_pwq(cpu, wq);
+		struct worker_pool *pool = pwq->pool;
 
-		spin_lock_irq(&gcwq->lock);
+		spin_lock_irq(&pool->lock);
 
 		if (flush_color >= 0) {
-			BUG_ON(cwq->flush_color != -1);
+			BUG_ON(pwq->flush_color != -1);
 
-			if (cwq->nr_in_flight[flush_color]) {
-				cwq->flush_color = flush_color;
-				atomic_inc(&wq->nr_cwqs_to_flush);
+			if (pwq->nr_in_flight[flush_color]) {
+				pwq->flush_color = flush_color;
+				atomic_inc(&wq->nr_pwqs_to_flush);
 				wait = true;
 			}
 		}
 
 		if (work_color >= 0) {
-			BUG_ON(work_color != work_next_color(cwq->work_color));
-			cwq->work_color = work_color;
+			BUG_ON(work_color != work_next_color(pwq->work_color));
+			pwq->work_color = work_color;
 		}
 
-		spin_unlock_irq(&gcwq->lock);
+		spin_unlock_irq(&pool->lock);
 	}
 
-	if (flush_color >= 0 && atomic_dec_and_test(&wq->nr_cwqs_to_flush))
+	if (flush_color >= 0 && atomic_dec_and_test(&wq->nr_pwqs_to_flush))
 		complete(&wq->first_flusher->done);
 
 	return wait;
@@ -2655,7 +2579,7 @@ void flush_workqueue(struct workqueue_struct *wq)
 
 			wq->first_flusher = &this_flusher;
 
-			if (!flush_workqueue_prep_cwqs(wq, wq->flush_color,
+			if (!flush_workqueue_prep_pwqs(wq, wq->flush_color,
 						       wq->work_color)) {
 				/* nothing to flush, done */
 				wq->flush_color = next_color;
@@ -2666,7 +2590,7 @@ void flush_workqueue(struct workqueue_struct *wq)
 			/* wait in queue */
 			BUG_ON(wq->flush_color == this_flusher.flush_color);
 			list_add_tail(&this_flusher.list, &wq->flusher_queue);
-			flush_workqueue_prep_cwqs(wq, -1, wq->work_color);
+			flush_workqueue_prep_pwqs(wq, -1, wq->work_color);
 		}
 	} else {
 		/*
@@ -2733,7 +2657,7 @@ void flush_workqueue(struct workqueue_struct *wq)
 
 			list_splice_tail_init(&wq->flusher_overflow,
 					      &wq->flusher_queue);
-			flush_workqueue_prep_cwqs(wq, -1, wq->work_color);
+			flush_workqueue_prep_pwqs(wq, -1, wq->work_color);
 		}
 
 		if (list_empty(&wq->flusher_queue)) {
@@ -2743,7 +2667,7 @@ void flush_workqueue(struct workqueue_struct *wq)
 
 		/*
 		 * Need to flush more colors.  Make the next flusher
-		 * the new first flusher and arm cwqs.
+		 * the new first flusher and arm pwqs.
 		 */
 		BUG_ON(wq->flush_color == wq->work_color);
 		BUG_ON(wq->flush_color != next->flush_color);
@@ -2751,7 +2675,7 @@ void flush_workqueue(struct workqueue_struct *wq)
 		list_del_init(&next->list);
 		wq->first_flusher = next;
 
-		if (flush_workqueue_prep_cwqs(wq, wq->flush_color, -1))
+		if (flush_workqueue_prep_pwqs(wq, wq->flush_color, -1))
 			break;
 
 		/*
@@ -2794,13 +2718,13 @@ void drain_workqueue(struct workqueue_struct *wq)
 reflush:
 	flush_workqueue(wq);
 
-	for_each_cwq_cpu(cpu, wq) {
-		struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
+	for_each_pwq_cpu(cpu, wq) {
+		struct pool_workqueue *pwq = get_pwq(cpu, wq);
 		bool drained;
 
-		spin_lock_irq(&cwq->pool->gcwq->lock);
-		drained = !cwq->nr_active && list_empty(&cwq->delayed_works);
-		spin_unlock_irq(&cwq->pool->gcwq->lock);
+		spin_lock_irq(&pwq->pool->lock);
+		drained = !pwq->nr_active && list_empty(&pwq->delayed_works);
+		spin_unlock_irq(&pwq->pool->lock);
 
 		if (drained)
 			continue;
@@ -2822,34 +2746,29 @@ EXPORT_SYMBOL_GPL(drain_workqueue);
 static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr)
 {
 	struct worker *worker = NULL;
-	struct global_cwq *gcwq;
-	struct cpu_workqueue_struct *cwq;
+	struct worker_pool *pool;
+	struct pool_workqueue *pwq;
 
 	might_sleep();
-	gcwq = get_work_gcwq(work);
-	if (!gcwq)
+	pool = get_work_pool(work);
+	if (!pool)
 		return false;
 
-	spin_lock_irq(&gcwq->lock);
-	if (!list_empty(&work->entry)) {
-		/*
-		 * See the comment near try_to_grab_pending()->smp_rmb().
-		 * If it was re-queued to a different gcwq under us, we
-		 * are not going to wait.
-		 */
-		smp_rmb();
-		cwq = get_work_cwq(work);
-		if (unlikely(!cwq || gcwq != cwq->pool->gcwq))
+	spin_lock_irq(&pool->lock);
+	/* see the comment in try_to_grab_pending() with the same code */
+	pwq = get_work_pwq(work);
+	if (pwq) {
+		if (unlikely(pwq->pool != pool))
 			goto already_gone;
 	} else {
-		worker = find_worker_executing_work(gcwq, work);
+		worker = find_worker_executing_work(pool, work);
 		if (!worker)
 			goto already_gone;
-		cwq = worker->current_cwq;
+		pwq = worker->current_pwq;
 	}
 
-	insert_wq_barrier(cwq, barr, work, worker);
-	spin_unlock_irq(&gcwq->lock);
+	insert_wq_barrier(pwq, barr, work, worker);
+	spin_unlock_irq(&pool->lock);
 
 	/*
 	 * If @max_active is 1 or rescuer is in use, flushing another work
@@ -2857,15 +2776,15 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr)
 	 * flusher is not running on the same workqueue by verifying write
 	 * access.
 	 */
-	if (cwq->wq->saved_max_active == 1 || cwq->wq->flags & WQ_RESCUER)
-		lock_map_acquire(&cwq->wq->lockdep_map);
+	if (pwq->wq->saved_max_active == 1 || pwq->wq->flags & WQ_RESCUER)
+		lock_map_acquire(&pwq->wq->lockdep_map);
 	else
-		lock_map_acquire_read(&cwq->wq->lockdep_map);
-	lock_map_release(&cwq->wq->lockdep_map);
+		lock_map_acquire_read(&pwq->wq->lockdep_map);
+	lock_map_release(&pwq->wq->lockdep_map);
 
 	return true;
 already_gone:
-	spin_unlock_irq(&gcwq->lock);
+	spin_unlock_irq(&pool->lock);
 	return false;
 }
 
@@ -2961,8 +2880,7 @@ bool flush_delayed_work(struct delayed_work *dwork)
 {
 	local_irq_disable();
 	if (del_timer_sync(&dwork->timer))
-		__queue_work(dwork->cpu,
-			     get_work_cwq(&dwork->work)->wq, &dwork->work);
+		__queue_work(dwork->cpu, dwork->wq, &dwork->work);
 	local_irq_enable();
 	return flush_work(&dwork->work);
 }
@@ -2992,7 +2910,8 @@ bool cancel_delayed_work(struct delayed_work *dwork)
 	if (unlikely(ret < 0))
 		return false;
 
-	set_work_cpu_and_clear_pending(&dwork->work, work_cpu(&dwork->work));
+	set_work_pool_and_clear_pending(&dwork->work,
+					get_work_pool_id(&dwork->work));
 	local_irq_restore(flags);
 	return ret;
 }
@@ -3171,46 +3090,46 @@ int keventd_up(void)
 	return system_wq != NULL;
 }
 
-static int alloc_cwqs(struct workqueue_struct *wq)
+static int alloc_pwqs(struct workqueue_struct *wq)
 {
 	/*
-	 * cwqs are forced aligned according to WORK_STRUCT_FLAG_BITS.
+	 * pwqs are forced aligned according to WORK_STRUCT_FLAG_BITS.
 	 * Make sure that the alignment isn't lower than that of
 	 * unsigned long long.
 	 */
-	const size_t size = sizeof(struct cpu_workqueue_struct);
+	const size_t size = sizeof(struct pool_workqueue);
 	const size_t align = max_t(size_t, 1 << WORK_STRUCT_FLAG_BITS,
 				   __alignof__(unsigned long long));
 
 	if (!(wq->flags & WQ_UNBOUND))
-		wq->cpu_wq.pcpu = __alloc_percpu(size, align);
+		wq->pool_wq.pcpu = __alloc_percpu(size, align);
 	else {
 		void *ptr;
 
 		/*
-		 * Allocate enough room to align cwq and put an extra
+		 * Allocate enough room to align pwq and put an extra
 		 * pointer at the end pointing back to the originally
 		 * allocated pointer which will be used for free.
 		 */
 		ptr = kzalloc(size + align + sizeof(void *), GFP_KERNEL);
 		if (ptr) {
-			wq->cpu_wq.single = PTR_ALIGN(ptr, align);
-			*(void **)(wq->cpu_wq.single + 1) = ptr;
+			wq->pool_wq.single = PTR_ALIGN(ptr, align);
+			*(void **)(wq->pool_wq.single + 1) = ptr;
 		}
 	}
 
 	/* just in case, make sure it's actually aligned */
-	BUG_ON(!IS_ALIGNED(wq->cpu_wq.v, align));
-	return wq->cpu_wq.v ? 0 : -ENOMEM;
+	BUG_ON(!IS_ALIGNED(wq->pool_wq.v, align));
+	return wq->pool_wq.v ? 0 : -ENOMEM;
 }
 
-static void free_cwqs(struct workqueue_struct *wq)
+static void free_pwqs(struct workqueue_struct *wq)
 {
 	if (!(wq->flags & WQ_UNBOUND))
-		free_percpu(wq->cpu_wq.pcpu);
-	else if (wq->cpu_wq.single) {
-		/* the pointer to free is stored right after the cwq */
-		kfree(*(void **)(wq->cpu_wq.single + 1));
+		free_percpu(wq->pool_wq.pcpu);
+	else if (wq->pool_wq.single) {
+		/* the pointer to free is stored right after the pwq */
+		kfree(*(void **)(wq->pool_wq.single + 1));
 	}
 }
 
@@ -3264,27 +3183,25 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt,
 	wq->flags = flags;
 	wq->saved_max_active = max_active;
 	mutex_init(&wq->flush_mutex);
-	atomic_set(&wq->nr_cwqs_to_flush, 0);
+	atomic_set(&wq->nr_pwqs_to_flush, 0);
 	INIT_LIST_HEAD(&wq->flusher_queue);
 	INIT_LIST_HEAD(&wq->flusher_overflow);
 
 	lockdep_init_map(&wq->lockdep_map, lock_name, key, 0);
 	INIT_LIST_HEAD(&wq->list);
 
-	if (alloc_cwqs(wq) < 0)
+	if (alloc_pwqs(wq) < 0)
 		goto err;
 
-	for_each_cwq_cpu(cpu, wq) {
-		struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
-		struct global_cwq *gcwq = get_gcwq(cpu);
-		int pool_idx = (bool)(flags & WQ_HIGHPRI);
-
-		BUG_ON((unsigned long)cwq & WORK_STRUCT_FLAG_MASK);
-		cwq->pool = &gcwq->pools[pool_idx];
-		cwq->wq = wq;
-		cwq->flush_color = -1;
-		cwq->max_active = max_active;
-		INIT_LIST_HEAD(&cwq->delayed_works);
+	for_each_pwq_cpu(cpu, wq) {
+		struct pool_workqueue *pwq = get_pwq(cpu, wq);
+
+		BUG_ON((unsigned long)pwq & WORK_STRUCT_FLAG_MASK);
+		pwq->pool = get_std_worker_pool(cpu, flags & WQ_HIGHPRI);
+		pwq->wq = wq;
+		pwq->flush_color = -1;
+		pwq->max_active = max_active;
+		INIT_LIST_HEAD(&pwq->delayed_works);
 	}
 
 	if (flags & WQ_RESCUER) {
@@ -3297,7 +3214,8 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt,
 		if (!rescuer)
 			goto err;
 
-		rescuer->task = kthread_create(rescuer_thread, wq, "%s",
+		rescuer->rescue_wq = wq;
+		rescuer->task = kthread_create(rescuer_thread, rescuer, "%s",
 					       wq->name);
 		if (IS_ERR(rescuer->task))
 			goto err;
@@ -3314,8 +3232,8 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt,
 	spin_lock(&workqueue_lock);
 
 	if (workqueue_freezing && wq->flags & WQ_FREEZABLE)
-		for_each_cwq_cpu(cpu, wq)
-			get_cwq(cpu, wq)->max_active = 0;
+		for_each_pwq_cpu(cpu, wq)
+			get_pwq(cpu, wq)->max_active = 0;
 
 	list_add(&wq->list, &workqueues);
 
@@ -3324,7 +3242,7 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt,
 	return wq;
 err:
 	if (wq) {
-		free_cwqs(wq);
+		free_pwqs(wq);
 		free_mayday_mask(wq->mayday_mask);
 		kfree(wq->rescuer);
 		kfree(wq);
@@ -3355,14 +3273,14 @@ void destroy_workqueue(struct workqueue_struct *wq)
 	spin_unlock(&workqueue_lock);
 
 	/* sanity check */
-	for_each_cwq_cpu(cpu, wq) {
-		struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
+	for_each_pwq_cpu(cpu, wq) {
+		struct pool_workqueue *pwq = get_pwq(cpu, wq);
 		int i;
 
 		for (i = 0; i < WORK_NR_COLORS; i++)
-			BUG_ON(cwq->nr_in_flight[i]);
-		BUG_ON(cwq->nr_active);
-		BUG_ON(!list_empty(&cwq->delayed_works));
+			BUG_ON(pwq->nr_in_flight[i]);
+		BUG_ON(pwq->nr_active);
+		BUG_ON(!list_empty(&pwq->delayed_works));
 	}
 
 	if (wq->flags & WQ_RESCUER) {
@@ -3371,29 +3289,29 @@ void destroy_workqueue(struct workqueue_struct *wq)
 		kfree(wq->rescuer);
 	}
 
-	free_cwqs(wq);
+	free_pwqs(wq);
 	kfree(wq);
 }
 EXPORT_SYMBOL_GPL(destroy_workqueue);
 
 /**
- * cwq_set_max_active - adjust max_active of a cwq
- * @cwq: target cpu_workqueue_struct
+ * pwq_set_max_active - adjust max_active of a pwq
+ * @pwq: target pool_workqueue
  * @max_active: new max_active value.
  *
- * Set @cwq->max_active to @max_active and activate delayed works if
+ * Set @pwq->max_active to @max_active and activate delayed works if
  * increased.
  *
  * CONTEXT:
- * spin_lock_irq(gcwq->lock).
+ * spin_lock_irq(pool->lock).
  */
-static void cwq_set_max_active(struct cpu_workqueue_struct *cwq, int max_active)
+static void pwq_set_max_active(struct pool_workqueue *pwq, int max_active)
 {
-	cwq->max_active = max_active;
+	pwq->max_active = max_active;
 
-	while (!list_empty(&cwq->delayed_works) &&
-	       cwq->nr_active < cwq->max_active)
-		cwq_activate_first_delayed(cwq);
+	while (!list_empty(&pwq->delayed_works) &&
+	       pwq->nr_active < pwq->max_active)
+		pwq_activate_first_delayed(pwq);
 }
 
 /**
@@ -3416,16 +3334,17 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active)
 
 	wq->saved_max_active = max_active;
 
-	for_each_cwq_cpu(cpu, wq) {
-		struct global_cwq *gcwq = get_gcwq(cpu);
+	for_each_pwq_cpu(cpu, wq) {
+		struct pool_workqueue *pwq = get_pwq(cpu, wq);
+		struct worker_pool *pool = pwq->pool;
 
-		spin_lock_irq(&gcwq->lock);
+		spin_lock_irq(&pool->lock);
 
 		if (!(wq->flags & WQ_FREEZABLE) ||
-		    !(gcwq->flags & GCWQ_FREEZING))
-			cwq_set_max_active(get_cwq(gcwq->cpu, wq), max_active);
+		    !(pool->flags & POOL_FREEZING))
+			pwq_set_max_active(pwq, max_active);
 
-		spin_unlock_irq(&gcwq->lock);
+		spin_unlock_irq(&pool->lock);
 	}
 
 	spin_unlock(&workqueue_lock);
@@ -3446,57 +3365,38 @@ EXPORT_SYMBOL_GPL(workqueue_set_max_active);
  */
 bool workqueue_congested(unsigned int cpu, struct workqueue_struct *wq)
 {
-	struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
+	struct pool_workqueue *pwq = get_pwq(cpu, wq);
 
-	return !list_empty(&cwq->delayed_works);
+	return !list_empty(&pwq->delayed_works);
 }
 EXPORT_SYMBOL_GPL(workqueue_congested);
 
 /**
- * work_cpu - return the last known associated cpu for @work
- * @work: the work of interest
- *
- * RETURNS:
- * CPU number if @work was ever queued.  WORK_CPU_NONE otherwise.
- */
-unsigned int work_cpu(struct work_struct *work)
-{
-	struct global_cwq *gcwq = get_work_gcwq(work);
-
-	return gcwq ? gcwq->cpu : WORK_CPU_NONE;
-}
-EXPORT_SYMBOL_GPL(work_cpu);
-
-/**
  * work_busy - test whether a work is currently pending or running
  * @work: the work to be tested
  *
  * Test whether @work is currently pending or running.  There is no
  * synchronization around this function and the test result is
  * unreliable and only useful as advisory hints or for debugging.
- * Especially for reentrant wqs, the pending state might hide the
- * running state.
  *
  * RETURNS:
  * OR'd bitmask of WORK_BUSY_* bits.
  */
 unsigned int work_busy(struct work_struct *work)
 {
-	struct global_cwq *gcwq = get_work_gcwq(work);
+	struct worker_pool *pool = get_work_pool(work);
 	unsigned long flags;
 	unsigned int ret = 0;
 
-	if (!gcwq)
-		return 0;
-
-	spin_lock_irqsave(&gcwq->lock, flags);
-
 	if (work_pending(work))
 		ret |= WORK_BUSY_PENDING;
-	if (find_worker_executing_work(gcwq, work))
-		ret |= WORK_BUSY_RUNNING;
 
-	spin_unlock_irqrestore(&gcwq->lock, flags);
+	if (pool) {
+		spin_lock_irqsave(&pool->lock, flags);
+		if (find_worker_executing_work(pool, work))
+			ret |= WORK_BUSY_RUNNING;
+		spin_unlock_irqrestore(&pool->lock, flags);
+	}
 
 	return ret;
 }
@@ -3506,65 +3406,48 @@ EXPORT_SYMBOL_GPL(work_busy);
  * CPU hotplug.
  *
  * There are two challenges in supporting CPU hotplug.  Firstly, there
- * are a lot of assumptions on strong associations among work, cwq and
- * gcwq which make migrating pending and scheduled works very
+ * are a lot of assumptions on strong associations among work, pwq and
+ * pool which make migrating pending and scheduled works very
  * difficult to implement without impacting hot paths.  Secondly,
- * gcwqs serve mix of short, long and very long running works making
+ * worker pools serve mix of short, long and very long running works making
  * blocked draining impractical.
  *
- * This is solved by allowing a gcwq to be disassociated from the CPU
+ * This is solved by allowing the pools to be disassociated from the CPU
  * running as an unbound one and allowing it to be reattached later if the
  * cpu comes back online.
  */
 
-/* claim manager positions of all pools */
-static void gcwq_claim_assoc_and_lock(struct global_cwq *gcwq)
+static void wq_unbind_fn(struct work_struct *work)
 {
-	struct worker_pool *pool;
-
-	for_each_worker_pool(pool, gcwq)
-		mutex_lock_nested(&pool->assoc_mutex, pool - gcwq->pools);
-	spin_lock_irq(&gcwq->lock);
-}
-
-/* release manager positions */
-static void gcwq_release_assoc_and_unlock(struct global_cwq *gcwq)
-{
-	struct worker_pool *pool;
-
-	spin_unlock_irq(&gcwq->lock);
-	for_each_worker_pool(pool, gcwq)
-		mutex_unlock(&pool->assoc_mutex);
-}
-
-static void gcwq_unbind_fn(struct work_struct *work)
-{
-	struct global_cwq *gcwq = get_gcwq(smp_processor_id());
+	int cpu = smp_processor_id();
 	struct worker_pool *pool;
 	struct worker *worker;
-	struct hlist_node *pos;
 	int i;
 
-	BUG_ON(gcwq->cpu != smp_processor_id());
+	for_each_std_worker_pool(pool, cpu) {
+		BUG_ON(cpu != smp_processor_id());
 
-	gcwq_claim_assoc_and_lock(gcwq);
+		mutex_lock(&pool->assoc_mutex);
+		spin_lock_irq(&pool->lock);
 
-	/*
-	 * We've claimed all manager positions.  Make all workers unbound
-	 * and set DISASSOCIATED.  Before this, all workers except for the
-	 * ones which are still executing works from before the last CPU
-	 * down must be on the cpu.  After this, they may become diasporas.
-	 */
-	for_each_worker_pool(pool, gcwq)
+		/*
+		 * We've claimed all manager positions.  Make all workers
+		 * unbound and set DISASSOCIATED.  Before this, all workers
+		 * except for the ones which are still executing works from
+		 * before the last CPU down must be on the cpu.  After
+		 * this, they may become diasporas.
+		 */
 		list_for_each_entry(worker, &pool->idle_list, entry)
 			worker->flags |= WORKER_UNBOUND;
 
-	for_each_busy_worker(worker, i, pos, gcwq)
-		worker->flags |= WORKER_UNBOUND;
+		for_each_busy_worker(worker, i, pool)
+			worker->flags |= WORKER_UNBOUND;
 
-	gcwq->flags |= GCWQ_DISASSOCIATED;
+		pool->flags |= POOL_DISASSOCIATED;
 
-	gcwq_release_assoc_and_unlock(gcwq);
+		spin_unlock_irq(&pool->lock);
+		mutex_unlock(&pool->assoc_mutex);
+	}
 
 	/*
 	 * Call schedule() so that we cross rq->lock and thus can guarantee
@@ -3576,16 +3459,16 @@ static void gcwq_unbind_fn(struct work_struct *work)
 	/*
 	 * Sched callbacks are disabled now.  Zap nr_running.  After this,
 	 * nr_running stays zero and need_more_worker() and keep_working()
-	 * are always true as long as the worklist is not empty.  @gcwq now
-	 * behaves as unbound (in terms of concurrency management) gcwq
-	 * which is served by workers tied to the CPU.
+	 * are always true as long as the worklist is not empty.  Pools on
+	 * @cpu now behave as unbound (in terms of concurrency management)
+	 * pools which are served by workers tied to the CPU.
 	 *
 	 * On return from this function, the current worker would trigger
 	 * unbound chain execution of pending work items if other workers
 	 * didn't already.
 	 */
-	for_each_worker_pool(pool, gcwq)
-		atomic_set(get_pool_nr_running(pool), 0);
+	for_each_std_worker_pool(pool, cpu)
+		atomic_set(&pool->nr_running, 0);
 }
 
 /*
@@ -3597,12 +3480,11 @@ static int __cpuinit workqueue_cpu_up_callback(struct notifier_block *nfb,
 					       void *hcpu)
 {
 	unsigned int cpu = (unsigned long)hcpu;
-	struct global_cwq *gcwq = get_gcwq(cpu);
 	struct worker_pool *pool;
 
 	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_UP_PREPARE:
-		for_each_worker_pool(pool, gcwq) {
+		for_each_std_worker_pool(pool, cpu) {
 			struct worker *worker;
 
 			if (pool->nr_workers)
@@ -3612,18 +3494,24 @@ static int __cpuinit workqueue_cpu_up_callback(struct notifier_block *nfb,
 			if (!worker)
 				return NOTIFY_BAD;
 
-			spin_lock_irq(&gcwq->lock);
+			spin_lock_irq(&pool->lock);
 			start_worker(worker);
-			spin_unlock_irq(&gcwq->lock);
+			spin_unlock_irq(&pool->lock);
 		}
 		break;
 
 	case CPU_DOWN_FAILED:
 	case CPU_ONLINE:
-		gcwq_claim_assoc_and_lock(gcwq);
-		gcwq->flags &= ~GCWQ_DISASSOCIATED;
-		rebind_workers(gcwq);
-		gcwq_release_assoc_and_unlock(gcwq);
+		for_each_std_worker_pool(pool, cpu) {
+			mutex_lock(&pool->assoc_mutex);
+			spin_lock_irq(&pool->lock);
+
+			pool->flags &= ~POOL_DISASSOCIATED;
+			rebind_workers(pool);
+
+			spin_unlock_irq(&pool->lock);
+			mutex_unlock(&pool->assoc_mutex);
+		}
 		break;
 	}
 	return NOTIFY_OK;
@@ -3643,7 +3531,7 @@ static int __cpuinit workqueue_cpu_down_callback(struct notifier_block *nfb,
 	switch (action & ~CPU_TASKS_FROZEN) {
 	case CPU_DOWN_PREPARE:
 		/* unbinding should happen on the local CPU */
-		INIT_WORK_ONSTACK(&unbind_work, gcwq_unbind_fn);
+		INIT_WORK_ONSTACK(&unbind_work, wq_unbind_fn);
 		queue_work_on(cpu, system_highpri_wq, &unbind_work);
 		flush_work(&unbind_work);
 		break;
@@ -3696,10 +3584,10 @@ EXPORT_SYMBOL_GPL(work_on_cpu);
  *
  * Start freezing workqueues.  After this function returns, all freezable
  * workqueues will queue new works to their frozen_works list instead of
- * gcwq->worklist.
+ * pool->worklist.
  *
  * CONTEXT:
- * Grabs and releases workqueue_lock and gcwq->lock's.
+ * Grabs and releases workqueue_lock and pool->lock's.
  */
 void freeze_workqueues_begin(void)
 {
@@ -3710,23 +3598,26 @@ void freeze_workqueues_begin(void)
 	BUG_ON(workqueue_freezing);
 	workqueue_freezing = true;
 
-	for_each_gcwq_cpu(cpu) {
-		struct global_cwq *gcwq = get_gcwq(cpu);
+	for_each_wq_cpu(cpu) {
+		struct worker_pool *pool;
 		struct workqueue_struct *wq;
 
-		spin_lock_irq(&gcwq->lock);
+		for_each_std_worker_pool(pool, cpu) {
+			spin_lock_irq(&pool->lock);
 
-		BUG_ON(gcwq->flags & GCWQ_FREEZING);
-		gcwq->flags |= GCWQ_FREEZING;
+			WARN_ON_ONCE(pool->flags & POOL_FREEZING);
+			pool->flags |= POOL_FREEZING;
 
-		list_for_each_entry(wq, &workqueues, list) {
-			struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
+			list_for_each_entry(wq, &workqueues, list) {
+				struct pool_workqueue *pwq = get_pwq(cpu, wq);
 
-			if (cwq && wq->flags & WQ_FREEZABLE)
-				cwq->max_active = 0;
-		}
+				if (pwq && pwq->pool == pool &&
+				    (wq->flags & WQ_FREEZABLE))
+					pwq->max_active = 0;
+			}
 
-		spin_unlock_irq(&gcwq->lock);
+			spin_unlock_irq(&pool->lock);
+		}
 	}
 
 	spin_unlock(&workqueue_lock);
@@ -3754,20 +3645,20 @@ bool freeze_workqueues_busy(void)
 
 	BUG_ON(!workqueue_freezing);
 
-	for_each_gcwq_cpu(cpu) {
+	for_each_wq_cpu(cpu) {
 		struct workqueue_struct *wq;
 		/*
 		 * nr_active is monotonically decreasing.  It's safe
 		 * to peek without lock.
 		 */
 		list_for_each_entry(wq, &workqueues, list) {
-			struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
+			struct pool_workqueue *pwq = get_pwq(cpu, wq);
 
-			if (!cwq || !(wq->flags & WQ_FREEZABLE))
+			if (!pwq || !(wq->flags & WQ_FREEZABLE))
 				continue;
 
-			BUG_ON(cwq->nr_active < 0);
-			if (cwq->nr_active) {
+			BUG_ON(pwq->nr_active < 0);
+			if (pwq->nr_active) {
 				busy = true;
 				goto out_unlock;
 			}
@@ -3782,10 +3673,10 @@ out_unlock:
  * thaw_workqueues - thaw workqueues
  *
  * Thaw workqueues.  Normal queueing is restored and all collected
- * frozen works are transferred to their respective gcwq worklists.
+ * frozen works are transferred to their respective pool worklists.
  *
  * CONTEXT:
- * Grabs and releases workqueue_lock and gcwq->lock's.
+ * Grabs and releases workqueue_lock and pool->lock's.
  */
 void thaw_workqueues(void)
 {
@@ -3796,30 +3687,31 @@ void thaw_workqueues(void)
 	if (!workqueue_freezing)
 		goto out_unlock;
 
-	for_each_gcwq_cpu(cpu) {
-		struct global_cwq *gcwq = get_gcwq(cpu);
+	for_each_wq_cpu(cpu) {
 		struct worker_pool *pool;
 		struct workqueue_struct *wq;
 
-		spin_lock_irq(&gcwq->lock);
+		for_each_std_worker_pool(pool, cpu) {
+			spin_lock_irq(&pool->lock);
 
-		BUG_ON(!(gcwq->flags & GCWQ_FREEZING));
-		gcwq->flags &= ~GCWQ_FREEZING;
+			WARN_ON_ONCE(!(pool->flags & POOL_FREEZING));
+			pool->flags &= ~POOL_FREEZING;
 
-		list_for_each_entry(wq, &workqueues, list) {
-			struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
+			list_for_each_entry(wq, &workqueues, list) {
+				struct pool_workqueue *pwq = get_pwq(cpu, wq);
 
-			if (!cwq || !(wq->flags & WQ_FREEZABLE))
-				continue;
+				if (!pwq || pwq->pool != pool ||
+				    !(wq->flags & WQ_FREEZABLE))
+					continue;
 
-			/* restore max_active and repopulate worklist */
-			cwq_set_max_active(cwq, wq->saved_max_active);
-		}
+				/* restore max_active and repopulate worklist */
+				pwq_set_max_active(pwq, wq->saved_max_active);
+			}
 
-		for_each_worker_pool(pool, gcwq)
 			wake_up_worker(pool);
 
-		spin_unlock_irq(&gcwq->lock);
+			spin_unlock_irq(&pool->lock);
+		}
 	}
 
 	workqueue_freezing = false;
@@ -3831,60 +3723,56 @@ out_unlock:
 static int __init init_workqueues(void)
 {
 	unsigned int cpu;
-	int i;
 
-	/* make sure we have enough bits for OFFQ CPU number */
-	BUILD_BUG_ON((1LU << (BITS_PER_LONG - WORK_OFFQ_CPU_SHIFT)) <
-		     WORK_CPU_LAST);
+	/* make sure we have enough bits for OFFQ pool ID */
+	BUILD_BUG_ON((1LU << (BITS_PER_LONG - WORK_OFFQ_POOL_SHIFT)) <
+		     WORK_CPU_END * NR_STD_WORKER_POOLS);
 
 	cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP);
 	hotcpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN);
 
-	/* initialize gcwqs */
-	for_each_gcwq_cpu(cpu) {
-		struct global_cwq *gcwq = get_gcwq(cpu);
+	/* initialize CPU pools */
+	for_each_wq_cpu(cpu) {
 		struct worker_pool *pool;
 
-		spin_lock_init(&gcwq->lock);
-		gcwq->cpu = cpu;
-		gcwq->flags |= GCWQ_DISASSOCIATED;
-
-		for (i = 0; i < BUSY_WORKER_HASH_SIZE; i++)
-			INIT_HLIST_HEAD(&gcwq->busy_hash[i]);
-
-		for_each_worker_pool(pool, gcwq) {
-			pool->gcwq = gcwq;
+		for_each_std_worker_pool(pool, cpu) {
+			spin_lock_init(&pool->lock);
+			pool->cpu = cpu;
+			pool->flags |= POOL_DISASSOCIATED;
 			INIT_LIST_HEAD(&pool->worklist);
 			INIT_LIST_HEAD(&pool->idle_list);
+			hash_init(pool->busy_hash);
 
 			init_timer_deferrable(&pool->idle_timer);
 			pool->idle_timer.function = idle_worker_timeout;
 			pool->idle_timer.data = (unsigned long)pool;
 
-			setup_timer(&pool->mayday_timer, gcwq_mayday_timeout,
+			setup_timer(&pool->mayday_timer, pool_mayday_timeout,
 				    (unsigned long)pool);
 
 			mutex_init(&pool->assoc_mutex);
 			ida_init(&pool->worker_ida);
+
+			/* alloc pool ID */
+			BUG_ON(worker_pool_assign_id(pool));
 		}
 	}
 
 	/* create the initial worker */
-	for_each_online_gcwq_cpu(cpu) {
-		struct global_cwq *gcwq = get_gcwq(cpu);
+	for_each_online_wq_cpu(cpu) {
 		struct worker_pool *pool;
 
-		if (cpu != WORK_CPU_UNBOUND)
-			gcwq->flags &= ~GCWQ_DISASSOCIATED;
-
-		for_each_worker_pool(pool, gcwq) {
+		for_each_std_worker_pool(pool, cpu) {
 			struct worker *worker;
 
+			if (cpu != WORK_CPU_UNBOUND)
+				pool->flags &= ~POOL_DISASSOCIATED;
+
 			worker = create_worker(pool);
 			BUG_ON(!worker);
-			spin_lock_irq(&gcwq->lock);
+			spin_lock_irq(&pool->lock);
 			start_worker(worker);
-			spin_unlock_irq(&gcwq->lock);
+			spin_unlock_irq(&pool->lock);
 		}
 	}
 
diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h
new file mode 100644
index 000000000000..07650264ec15
--- /dev/null
+++ b/kernel/workqueue_internal.h
@@ -0,0 +1,65 @@
+/*
+ * kernel/workqueue_internal.h
+ *
+ * Workqueue internal header file.  Only to be included by workqueue and
+ * core kernel subsystems.
+ */
+#ifndef _KERNEL_WORKQUEUE_INTERNAL_H
+#define _KERNEL_WORKQUEUE_INTERNAL_H
+
+#include <linux/workqueue.h>
+#include <linux/kthread.h>
+
+struct worker_pool;
+
+/*
+ * The poor guys doing the actual heavy lifting.  All on-duty workers are
+ * either serving the manager role, on idle list or on busy hash.  For
+ * details on the locking annotation (L, I, X...), refer to workqueue.c.
+ *
+ * Only to be used in workqueue and async.
+ */
+struct worker {
+	/* on idle list while idle, on busy hash table while busy */
+	union {
+		struct list_head	entry;	/* L: while idle */
+		struct hlist_node	hentry;	/* L: while busy */
+	};
+
+	struct work_struct	*current_work;	/* L: work being processed */
+	work_func_t		current_func;	/* L: current_work's fn */
+	struct pool_workqueue	*current_pwq; /* L: current_work's pwq */
+	struct list_head	scheduled;	/* L: scheduled works */
+	struct task_struct	*task;		/* I: worker task */
+	struct worker_pool	*pool;		/* I: the associated pool */
+	/* 64 bytes boundary on 64bit, 32 on 32bit */
+	unsigned long		last_active;	/* L: last active timestamp */
+	unsigned int		flags;		/* X: flags */
+	int			id;		/* I: worker id */
+
+	/* for rebinding worker to CPU */
+	struct work_struct	rebind_work;	/* L: for busy worker */
+
+	/* used only by rescuers to point to the target workqueue */
+	struct workqueue_struct	*rescue_wq;	/* I: the workqueue to rescue */
+};
+
+/**
+ * current_wq_worker - return struct worker if %current is a workqueue worker
+ */
+static inline struct worker *current_wq_worker(void)
+{
+	if (current->flags & PF_WQ_WORKER)
+		return kthread_data(current);
+	return NULL;
+}
+
+/*
+ * Scheduler hooks for concurrency managed workqueue.  Only to be used from
+ * sched.c and workqueue.c.
+ */
+void wq_worker_waking_up(struct task_struct *task, unsigned int cpu);
+struct task_struct *wq_worker_sleeping(struct task_struct *task,
+				       unsigned int cpu);
+
+#endif /* _KERNEL_WORKQUEUE_INTERNAL_H */
diff --git a/kernel/workqueue_sched.h b/kernel/workqueue_sched.h
deleted file mode 100644
index 2d10fc98dc79..000000000000
--- a/kernel/workqueue_sched.h
+++ /dev/null
@@ -1,9 +0,0 @@
-/*
- * kernel/workqueue_sched.h
- *
- * Scheduler hooks for concurrency managed workqueue.  Only to be
- * included from sched.c and workqueue.c.
- */
-void wq_worker_waking_up(struct task_struct *task, unsigned int cpu);
-struct task_struct *wq_worker_sleeping(struct task_struct *task,
-				       unsigned int cpu);