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authorFrederic Weisbecker <fweisbec@gmail.com>2013-05-02 17:37:49 +0200
committerFrederic Weisbecker <fweisbec@gmail.com>2013-05-02 17:54:19 +0200
commitc032862fba51a3ca504752d3a25186b324c5ce83 (patch)
tree955dc2ba4ab3df76ecc2bb780ee84aca04967e8d /kernel/sched
parentMerge branch 'rcu/nohz' of git://git.kernel.org/pub/scm/linux/kernel/git/paul... (diff)
parentMerge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/ke... (diff)
downloadlinux-c032862fba51a3ca504752d3a25186b324c5ce83.tar.xz
linux-c032862fba51a3ca504752d3a25186b324c5ce83.zip
Merge commit '8700c95adb03' into timers/nohz
The full dynticks tree needs the latest RCU and sched upstream updates in order to fix some dependencies. Merge a common upstream merge point that has these updates. Conflicts: include/linux/perf_event.h kernel/rcutree.h kernel/rcutree_plugin.h Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/Makefile1
-rw-r--r--kernel/sched/clock.c26
-rw-r--r--kernel/sched/core.c299
-rw-r--r--kernel/sched/cpuacct.c296
-rw-r--r--kernel/sched/cpuacct.h17
-rw-r--r--kernel/sched/cputime.c20
-rw-r--r--kernel/sched/fair.c131
-rw-r--r--kernel/sched/features.h7
-rw-r--r--kernel/sched/idle_task.c16
-rw-r--r--kernel/sched/sched.h61
10 files changed, 464 insertions, 410 deletions
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index f06d249e103b..deaf90e4a1de 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_SMP) += cpupri.o
obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
obj-$(CONFIG_SCHEDSTATS) += stats.o
obj-$(CONFIG_SCHED_DEBUG) += debug.o
+obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o
diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index c685e31492df..c3ae1446461c 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -176,10 +176,36 @@ static u64 sched_clock_remote(struct sched_clock_data *scd)
u64 this_clock, remote_clock;
u64 *ptr, old_val, val;
+#if BITS_PER_LONG != 64
+again:
+ /*
+ * Careful here: The local and the remote clock values need to
+ * be read out atomic as we need to compare the values and
+ * then update either the local or the remote side. So the
+ * cmpxchg64 below only protects one readout.
+ *
+ * We must reread via sched_clock_local() in the retry case on
+ * 32bit as an NMI could use sched_clock_local() via the
+ * tracer and hit between the readout of
+ * the low32bit and the high 32bit portion.
+ */
+ this_clock = sched_clock_local(my_scd);
+ /*
+ * We must enforce atomic readout on 32bit, otherwise the
+ * update on the remote cpu can hit inbetween the readout of
+ * the low32bit and the high 32bit portion.
+ */
+ remote_clock = cmpxchg64(&scd->clock, 0, 0);
+#else
+ /*
+ * On 64bit the read of [my]scd->clock is atomic versus the
+ * update, so we can avoid the above 32bit dance.
+ */
sched_clock_local(my_scd);
again:
this_clock = my_scd->clock;
remote_clock = scd->clock;
+#endif
/*
* Use the opportunity that we have both locks
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index dd09def88567..e94842d4400c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -512,11 +512,6 @@ static inline void init_hrtick(void)
* the target CPU.
*/
#ifdef CONFIG_SMP
-
-#ifndef tsk_is_polling
-#define tsk_is_polling(t) 0
-#endif
-
void resched_task(struct task_struct *p)
{
int cpu;
@@ -1536,8 +1531,10 @@ static void try_to_wake_up_local(struct task_struct *p)
{
struct rq *rq = task_rq(p);
- BUG_ON(rq != this_rq());
- BUG_ON(p == current);
+ if (WARN_ON_ONCE(rq != this_rq()) ||
+ WARN_ON_ONCE(p == current))
+ return;
+
lockdep_assert_held(&rq->lock);
if (!raw_spin_trylock(&p->pi_lock)) {
@@ -3037,51 +3034,6 @@ void __sched schedule_preempt_disabled(void)
preempt_disable();
}
-#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
-
-static inline bool owner_running(struct mutex *lock, struct task_struct *owner)
-{
- if (lock->owner != owner)
- return false;
-
- /*
- * Ensure we emit the owner->on_cpu, dereference _after_ checking
- * lock->owner still matches owner, if that fails, owner might
- * point to free()d memory, if it still matches, the rcu_read_lock()
- * ensures the memory stays valid.
- */
- barrier();
-
- return owner->on_cpu;
-}
-
-/*
- * Look out! "owner" is an entirely speculative pointer
- * access and not reliable.
- */
-int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner)
-{
- if (!sched_feat(OWNER_SPIN))
- return 0;
-
- rcu_read_lock();
- while (owner_running(lock, owner)) {
- if (need_resched())
- break;
-
- arch_mutex_cpu_relax();
- }
- rcu_read_unlock();
-
- /*
- * We break out the loop above on need_resched() and when the
- * owner changed, which is a sign for heavy contention. Return
- * success only when lock->owner is NULL.
- */
- return lock->owner == NULL;
-}
-#endif
-
#ifdef CONFIG_PREEMPT
/*
* this is the entry point to schedule() from in-kernel preemption
@@ -4170,6 +4122,10 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
get_task_struct(p);
rcu_read_unlock();
+ if (p->flags & PF_NO_SETAFFINITY) {
+ retval = -EINVAL;
+ goto out_put_task;
+ }
if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
retval = -ENOMEM;
goto out_put_task;
@@ -4817,11 +4773,6 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
goto out;
}
- if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) {
- ret = -EINVAL;
- goto out;
- }
-
do_set_cpus_allowed(p, new_mask);
/* Can the task run on the task's current CPU? If so, we're done */
@@ -5043,7 +4994,7 @@ static void sd_free_ctl_entry(struct ctl_table **tablep)
}
static int min_load_idx = 0;
-static int max_load_idx = CPU_LOAD_IDX_MAX;
+static int max_load_idx = CPU_LOAD_IDX_MAX-1;
static void
set_table_entry(struct ctl_table *entry,
@@ -6292,7 +6243,7 @@ static void sched_init_numa(void)
* 'level' contains the number of unique distances, excluding the
* identity distance node_distance(i,i).
*
- * The sched_domains_nume_distance[] array includes the actual distance
+ * The sched_domains_numa_distance[] array includes the actual distance
* numbers.
*/
@@ -6913,7 +6864,7 @@ struct task_group root_task_group;
LIST_HEAD(task_groups);
#endif
-DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
+DECLARE_PER_CPU(cpumask_var_t, load_balance_mask);
void __init sched_init(void)
{
@@ -6950,7 +6901,7 @@ void __init sched_init(void)
#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_CPUMASK_OFFSTACK
for_each_possible_cpu(i) {
- per_cpu(load_balance_tmpmask, i) = (void *)ptr;
+ per_cpu(load_balance_mask, i) = (void *)ptr;
ptr += cpumask_size();
}
#endif /* CONFIG_CPUMASK_OFFSTACK */
@@ -6976,12 +6927,6 @@ void __init sched_init(void)
#endif /* CONFIG_CGROUP_SCHED */
-#ifdef CONFIG_CGROUP_CPUACCT
- root_cpuacct.cpustat = &kernel_cpustat;
- root_cpuacct.cpuusage = alloc_percpu(u64);
- /* Too early, not expected to fail */
- BUG_ON(!root_cpuacct.cpuusage);
-#endif
for_each_possible_cpu(i) {
struct rq *rq;
@@ -8083,226 +8028,6 @@ struct cgroup_subsys cpu_cgroup_subsys = {
#endif /* CONFIG_CGROUP_SCHED */
-#ifdef CONFIG_CGROUP_CPUACCT
-
-/*
- * CPU accounting code for task groups.
- *
- * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
- * (balbir@in.ibm.com).
- */
-
-struct cpuacct root_cpuacct;
-
-/* create a new cpu accounting group */
-static struct cgroup_subsys_state *cpuacct_css_alloc(struct cgroup *cgrp)
-{
- struct cpuacct *ca;
-
- if (!cgrp->parent)
- return &root_cpuacct.css;
-
- ca = kzalloc(sizeof(*ca), GFP_KERNEL);
- if (!ca)
- goto out;
-
- ca->cpuusage = alloc_percpu(u64);
- if (!ca->cpuusage)
- goto out_free_ca;
-
- ca->cpustat = alloc_percpu(struct kernel_cpustat);
- if (!ca->cpustat)
- goto out_free_cpuusage;
-
- return &ca->css;
-
-out_free_cpuusage:
- free_percpu(ca->cpuusage);
-out_free_ca:
- kfree(ca);
-out:
- return ERR_PTR(-ENOMEM);
-}
-
-/* destroy an existing cpu accounting group */
-static void cpuacct_css_free(struct cgroup *cgrp)
-{
- struct cpuacct *ca = cgroup_ca(cgrp);
-
- free_percpu(ca->cpustat);
- free_percpu(ca->cpuusage);
- kfree(ca);
-}
-
-static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
-{
- u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
- u64 data;
-
-#ifndef CONFIG_64BIT
- /*
- * Take rq->lock to make 64-bit read safe on 32-bit platforms.
- */
- raw_spin_lock_irq(&cpu_rq(cpu)->lock);
- data = *cpuusage;
- raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
-#else
- data = *cpuusage;
-#endif
-
- return data;
-}
-
-static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
-{
- u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
-
-#ifndef CONFIG_64BIT
- /*
- * Take rq->lock to make 64-bit write safe on 32-bit platforms.
- */
- raw_spin_lock_irq(&cpu_rq(cpu)->lock);
- *cpuusage = val;
- raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
-#else
- *cpuusage = val;
-#endif
-}
-
-/* return total cpu usage (in nanoseconds) of a group */
-static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
-{
- struct cpuacct *ca = cgroup_ca(cgrp);
- u64 totalcpuusage = 0;
- int i;
-
- for_each_present_cpu(i)
- totalcpuusage += cpuacct_cpuusage_read(ca, i);
-
- return totalcpuusage;
-}
-
-static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype,
- u64 reset)
-{
- struct cpuacct *ca = cgroup_ca(cgrp);
- int err = 0;
- int i;
-
- if (reset) {
- err = -EINVAL;
- goto out;
- }
-
- for_each_present_cpu(i)
- cpuacct_cpuusage_write(ca, i, 0);
-
-out:
- return err;
-}
-
-static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft,
- struct seq_file *m)
-{
- struct cpuacct *ca = cgroup_ca(cgroup);
- u64 percpu;
- int i;
-
- for_each_present_cpu(i) {
- percpu = cpuacct_cpuusage_read(ca, i);
- seq_printf(m, "%llu ", (unsigned long long) percpu);
- }
- seq_printf(m, "\n");
- return 0;
-}
-
-static const char *cpuacct_stat_desc[] = {
- [CPUACCT_STAT_USER] = "user",
- [CPUACCT_STAT_SYSTEM] = "system",
-};
-
-static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft,
- struct cgroup_map_cb *cb)
-{
- struct cpuacct *ca = cgroup_ca(cgrp);
- int cpu;
- s64 val = 0;
-
- for_each_online_cpu(cpu) {
- struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
- val += kcpustat->cpustat[CPUTIME_USER];
- val += kcpustat->cpustat[CPUTIME_NICE];
- }
- val = cputime64_to_clock_t(val);
- cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_USER], val);
-
- val = 0;
- for_each_online_cpu(cpu) {
- struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
- val += kcpustat->cpustat[CPUTIME_SYSTEM];
- val += kcpustat->cpustat[CPUTIME_IRQ];
- val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
- }
-
- val = cputime64_to_clock_t(val);
- cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
-
- return 0;
-}
-
-static struct cftype files[] = {
- {
- .name = "usage",
- .read_u64 = cpuusage_read,
- .write_u64 = cpuusage_write,
- },
- {
- .name = "usage_percpu",
- .read_seq_string = cpuacct_percpu_seq_read,
- },
- {
- .name = "stat",
- .read_map = cpuacct_stats_show,
- },
- { } /* terminate */
-};
-
-/*
- * charge this task's execution time to its accounting group.
- *
- * called with rq->lock held.
- */
-void cpuacct_charge(struct task_struct *tsk, u64 cputime)
-{
- struct cpuacct *ca;
- int cpu;
-
- if (unlikely(!cpuacct_subsys.active))
- return;
-
- cpu = task_cpu(tsk);
-
- rcu_read_lock();
-
- ca = task_ca(tsk);
-
- for (; ca; ca = parent_ca(ca)) {
- u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
- *cpuusage += cputime;
- }
-
- rcu_read_unlock();
-}
-
-struct cgroup_subsys cpuacct_subsys = {
- .name = "cpuacct",
- .css_alloc = cpuacct_css_alloc,
- .css_free = cpuacct_css_free,
- .subsys_id = cpuacct_subsys_id,
- .base_cftypes = files,
-};
-#endif /* CONFIG_CGROUP_CPUACCT */
-
void dump_cpu_task(int cpu)
{
pr_info("Task dump for CPU %d:\n", cpu);
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
new file mode 100644
index 000000000000..dbb7e2cd95eb
--- /dev/null
+++ b/kernel/sched/cpuacct.c
@@ -0,0 +1,296 @@
+#include <linux/cgroup.h>
+#include <linux/slab.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+#include <linux/cpumask.h>
+#include <linux/seq_file.h>
+#include <linux/rcupdate.h>
+#include <linux/kernel_stat.h>
+#include <linux/err.h>
+
+#include "sched.h"
+
+/*
+ * CPU accounting code for task groups.
+ *
+ * Based on the work by Paul Menage (menage@google.com) and Balbir Singh
+ * (balbir@in.ibm.com).
+ */
+
+/* Time spent by the tasks of the cpu accounting group executing in ... */
+enum cpuacct_stat_index {
+ CPUACCT_STAT_USER, /* ... user mode */
+ CPUACCT_STAT_SYSTEM, /* ... kernel mode */
+
+ CPUACCT_STAT_NSTATS,
+};
+
+/* track cpu usage of a group of tasks and its child groups */
+struct cpuacct {
+ struct cgroup_subsys_state css;
+ /* cpuusage holds pointer to a u64-type object on every cpu */
+ u64 __percpu *cpuusage;
+ struct kernel_cpustat __percpu *cpustat;
+};
+
+/* return cpu accounting group corresponding to this container */
+static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)
+{
+ return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id),
+ struct cpuacct, css);
+}
+
+/* return cpu accounting group to which this task belongs */
+static inline struct cpuacct *task_ca(struct task_struct *tsk)
+{
+ return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
+ struct cpuacct, css);
+}
+
+static inline struct cpuacct *__parent_ca(struct cpuacct *ca)
+{
+ return cgroup_ca(ca->css.cgroup->parent);
+}
+
+static inline struct cpuacct *parent_ca(struct cpuacct *ca)
+{
+ if (!ca->css.cgroup->parent)
+ return NULL;
+ return cgroup_ca(ca->css.cgroup->parent);
+}
+
+static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage);
+static struct cpuacct root_cpuacct = {
+ .cpustat = &kernel_cpustat,
+ .cpuusage = &root_cpuacct_cpuusage,
+};
+
+/* create a new cpu accounting group */
+static struct cgroup_subsys_state *cpuacct_css_alloc(struct cgroup *cgrp)
+{
+ struct cpuacct *ca;
+
+ if (!cgrp->parent)
+ return &root_cpuacct.css;
+
+ ca = kzalloc(sizeof(*ca), GFP_KERNEL);
+ if (!ca)
+ goto out;
+
+ ca->cpuusage = alloc_percpu(u64);
+ if (!ca->cpuusage)
+ goto out_free_ca;
+
+ ca->cpustat = alloc_percpu(struct kernel_cpustat);
+ if (!ca->cpustat)
+ goto out_free_cpuusage;
+
+ return &ca->css;
+
+out_free_cpuusage:
+ free_percpu(ca->cpuusage);
+out_free_ca:
+ kfree(ca);
+out:
+ return ERR_PTR(-ENOMEM);
+}
+
+/* destroy an existing cpu accounting group */
+static void cpuacct_css_free(struct cgroup *cgrp)
+{
+ struct cpuacct *ca = cgroup_ca(cgrp);
+
+ free_percpu(ca->cpustat);
+ free_percpu(ca->cpuusage);
+ kfree(ca);
+}
+
+static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
+{
+ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
+ u64 data;
+
+#ifndef CONFIG_64BIT
+ /*
+ * Take rq->lock to make 64-bit read safe on 32-bit platforms.
+ */
+ raw_spin_lock_irq(&cpu_rq(cpu)->lock);
+ data = *cpuusage;
+ raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
+#else
+ data = *cpuusage;
+#endif
+
+ return data;
+}
+
+static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
+{
+ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
+
+#ifndef CONFIG_64BIT
+ /*
+ * Take rq->lock to make 64-bit write safe on 32-bit platforms.
+ */
+ raw_spin_lock_irq(&cpu_rq(cpu)->lock);
+ *cpuusage = val;
+ raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
+#else
+ *cpuusage = val;
+#endif
+}
+
+/* return total cpu usage (in nanoseconds) of a group */
+static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
+{
+ struct cpuacct *ca = cgroup_ca(cgrp);
+ u64 totalcpuusage = 0;
+ int i;
+
+ for_each_present_cpu(i)
+ totalcpuusage += cpuacct_cpuusage_read(ca, i);
+
+ return totalcpuusage;
+}
+
+static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype,
+ u64 reset)
+{
+ struct cpuacct *ca = cgroup_ca(cgrp);
+ int err = 0;
+ int i;
+
+ if (reset) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ for_each_present_cpu(i)
+ cpuacct_cpuusage_write(ca, i, 0);
+
+out:
+ return err;
+}
+
+static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft,
+ struct seq_file *m)
+{
+ struct cpuacct *ca = cgroup_ca(cgroup);
+ u64 percpu;
+ int i;
+
+ for_each_present_cpu(i) {
+ percpu = cpuacct_cpuusage_read(ca, i);
+ seq_printf(m, "%llu ", (unsigned long long) percpu);
+ }
+ seq_printf(m, "\n");
+ return 0;
+}
+
+static const char * const cpuacct_stat_desc[] = {
+ [CPUACCT_STAT_USER] = "user",
+ [CPUACCT_STAT_SYSTEM] = "system",
+};
+
+static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft,
+ struct cgroup_map_cb *cb)
+{
+ struct cpuacct *ca = cgroup_ca(cgrp);
+ int cpu;
+ s64 val = 0;
+
+ for_each_online_cpu(cpu) {
+ struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
+ val += kcpustat->cpustat[CPUTIME_USER];
+ val += kcpustat->cpustat[CPUTIME_NICE];
+ }
+ val = cputime64_to_clock_t(val);
+ cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_USER], val);
+
+ val = 0;
+ for_each_online_cpu(cpu) {
+ struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
+ val += kcpustat->cpustat[CPUTIME_SYSTEM];
+ val += kcpustat->cpustat[CPUTIME_IRQ];
+ val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
+ }
+
+ val = cputime64_to_clock_t(val);
+ cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
+
+ return 0;
+}
+
+static struct cftype files[] = {
+ {
+ .name = "usage",
+ .read_u64 = cpuusage_read,
+ .write_u64 = cpuusage_write,
+ },
+ {
+ .name = "usage_percpu",
+ .read_seq_string = cpuacct_percpu_seq_read,
+ },
+ {
+ .name = "stat",
+ .read_map = cpuacct_stats_show,
+ },
+ { } /* terminate */
+};
+
+/*
+ * charge this task's execution time to its accounting group.
+ *
+ * called with rq->lock held.
+ */
+void cpuacct_charge(struct task_struct *tsk, u64 cputime)
+{
+ struct cpuacct *ca;
+ int cpu;
+
+ cpu = task_cpu(tsk);
+
+ rcu_read_lock();
+
+ ca = task_ca(tsk);
+
+ while (true) {
+ u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
+ *cpuusage += cputime;
+
+ ca = parent_ca(ca);
+ if (!ca)
+ break;
+ }
+
+ rcu_read_unlock();
+}
+
+/*
+ * Add user/system time to cpuacct.
+ *
+ * Note: it's the caller that updates the account of the root cgroup.
+ */
+void cpuacct_account_field(struct task_struct *p, int index, u64 val)
+{
+ struct kernel_cpustat *kcpustat;
+ struct cpuacct *ca;
+
+ rcu_read_lock();
+ ca = task_ca(p);
+ while (ca != &root_cpuacct) {
+ kcpustat = this_cpu_ptr(ca->cpustat);
+ kcpustat->cpustat[index] += val;
+ ca = __parent_ca(ca);
+ }
+ rcu_read_unlock();
+}
+
+struct cgroup_subsys cpuacct_subsys = {
+ .name = "cpuacct",
+ .css_alloc = cpuacct_css_alloc,
+ .css_free = cpuacct_css_free,
+ .subsys_id = cpuacct_subsys_id,
+ .base_cftypes = files,
+ .early_init = 1,
+};
diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
new file mode 100644
index 000000000000..ed605624a5e7
--- /dev/null
+++ b/kernel/sched/cpuacct.h
@@ -0,0 +1,17 @@
+#ifdef CONFIG_CGROUP_CPUACCT
+
+extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
+extern void cpuacct_account_field(struct task_struct *p, int index, u64 val);
+
+#else
+
+static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime)
+{
+}
+
+static inline void
+cpuacct_account_field(struct task_struct *p, int index, u64 val)
+{
+}
+
+#endif
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 699d59756ece..ea32f02bf2c3 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -115,10 +115,6 @@ static int irqtime_account_si_update(void)
static inline void task_group_account_field(struct task_struct *p, int index,
u64 tmp)
{
-#ifdef CONFIG_CGROUP_CPUACCT
- struct kernel_cpustat *kcpustat;
- struct cpuacct *ca;
-#endif
/*
* Since all updates are sure to touch the root cgroup, we
* get ourselves ahead and touch it first. If the root cgroup
@@ -127,19 +123,7 @@ static inline void task_group_account_field(struct task_struct *p, int index,
*/
__get_cpu_var(kernel_cpustat).cpustat[index] += tmp;
-#ifdef CONFIG_CGROUP_CPUACCT
- if (unlikely(!cpuacct_subsys.active))
- return;
-
- rcu_read_lock();
- ca = task_ca(p);
- while (ca && (ca != &root_cpuacct)) {
- kcpustat = this_cpu_ptr(ca->cpustat);
- kcpustat->cpustat[index] += tmp;
- ca = parent_ca(ca);
- }
- rcu_read_unlock();
-#endif
+ cpuacct_account_field(p, index, tmp);
}
/*
@@ -310,7 +294,7 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
t = tsk;
do {
- task_cputime(tsk, &utime, &stime);
+ task_cputime(t, &utime, &stime);
times->utime += utime;
times->stime += stime;
times->sum_exec_runtime += task_sched_runtime(t);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 5c97fca091a7..c61a614465c8 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1563,6 +1563,27 @@ static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq,
se->avg.decay_count = atomic64_read(&cfs_rq->decay_counter);
} /* migrations, e.g. sleep=0 leave decay_count == 0 */
}
+
+/*
+ * Update the rq's load with the elapsed running time before entering
+ * idle. if the last scheduled task is not a CFS task, idle_enter will
+ * be the only way to update the runnable statistic.
+ */
+void idle_enter_fair(struct rq *this_rq)
+{
+ update_rq_runnable_avg(this_rq, 1);
+}
+
+/*
+ * Update the rq's load with the elapsed idle time before a task is
+ * scheduled. if the newly scheduled task is not a CFS task, idle_exit will
+ * be the only way to update the runnable statistic.
+ */
+void idle_exit_fair(struct rq *this_rq)
+{
+ update_rq_runnable_avg(this_rq, 0);
+}
+
#else
static inline void update_entity_load_avg(struct sched_entity *se,
int update_cfs_rq) {}
@@ -3875,12 +3896,16 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
int tsk_cache_hot = 0;
/*
* We do not migrate tasks that are:
- * 1) running (obviously), or
+ * 1) throttled_lb_pair, or
* 2) cannot be migrated to this CPU due to cpus_allowed, or
- * 3) are cache-hot on their current CPU.
+ * 3) running (obviously), or
+ * 4) are cache-hot on their current CPU.
*/
+ if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
+ return 0;
+
if (!cpumask_test_cpu(env->dst_cpu, tsk_cpus_allowed(p))) {
- int new_dst_cpu;
+ int cpu;
schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
@@ -3895,12 +3920,15 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
if (!env->dst_grpmask || (env->flags & LBF_SOME_PINNED))
return 0;
- new_dst_cpu = cpumask_first_and(env->dst_grpmask,
- tsk_cpus_allowed(p));
- if (new_dst_cpu < nr_cpu_ids) {
- env->flags |= LBF_SOME_PINNED;
- env->new_dst_cpu = new_dst_cpu;
+ /* Prevent to re-select dst_cpu via env's cpus */
+ for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) {
+ if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) {
+ env->flags |= LBF_SOME_PINNED;
+ env->new_dst_cpu = cpu;
+ break;
+ }
}
+
return 0;
}
@@ -3921,20 +3949,17 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
tsk_cache_hot = task_hot(p, env->src_rq->clock_task, env->sd);
if (!tsk_cache_hot ||
env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
-#ifdef CONFIG_SCHEDSTATS
+
if (tsk_cache_hot) {
schedstat_inc(env->sd, lb_hot_gained[env->idle]);
schedstat_inc(p, se.statistics.nr_forced_migrations);
}
-#endif
+
return 1;
}
- if (tsk_cache_hot) {
- schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
- return 0;
- }
- return 1;
+ schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
+ return 0;
}
/*
@@ -3949,9 +3974,6 @@ static int move_one_task(struct lb_env *env)
struct task_struct *p, *n;
list_for_each_entry_safe(p, n, &env->src_rq->cfs_tasks, se.group_node) {
- if (throttled_lb_pair(task_group(p), env->src_rq->cpu, env->dst_cpu))
- continue;
-
if (!can_migrate_task(p, env))
continue;
@@ -4003,7 +4025,7 @@ static int move_tasks(struct lb_env *env)
break;
}
- if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
+ if (!can_migrate_task(p, env))
goto next;
load = task_h_load(p);
@@ -4014,9 +4036,6 @@ static int move_tasks(struct lb_env *env)
if ((load / 2) > env->imbalance)
goto next;
- if (!can_migrate_task(p, env))
- goto next;
-
move_task(p, env);
pulled++;
env->imbalance -= load;
@@ -4961,7 +4980,7 @@ static struct rq *find_busiest_queue(struct lb_env *env,
#define MAX_PINNED_INTERVAL 512
/* Working cpumask for load_balance and load_balance_newidle. */
-DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
+DEFINE_PER_CPU(cpumask_var_t, load_balance_mask);
static int need_active_balance(struct lb_env *env)
{
@@ -4992,11 +5011,10 @@ static int load_balance(int this_cpu, struct rq *this_rq,
int *balance)
{
int ld_moved, cur_ld_moved, active_balance = 0;
- int lb_iterations, max_lb_iterations;
struct sched_group *group;
struct rq *busiest;
unsigned long flags;
- struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
+ struct cpumask *cpus = __get_cpu_var(load_balance_mask);
struct lb_env env = {
.sd = sd,
@@ -5008,8 +5026,14 @@ static int load_balance(int this_cpu, struct rq *this_rq,
.cpus = cpus,
};
+ /*
+ * For NEWLY_IDLE load_balancing, we don't need to consider
+ * other cpus in our group
+ */
+ if (idle == CPU_NEWLY_IDLE)
+ env.dst_grpmask = NULL;
+
cpumask_copy(cpus, cpu_active_mask);
- max_lb_iterations = cpumask_weight(env.dst_grpmask);
schedstat_inc(sd, lb_count[idle]);
@@ -5035,7 +5059,6 @@ redo:
schedstat_add(sd, lb_imbalance[idle], env.imbalance);
ld_moved = 0;
- lb_iterations = 1;
if (busiest->nr_running > 1) {
/*
* Attempt to move tasks. If find_busiest_group has found
@@ -5062,17 +5085,17 @@ more_balance:
double_rq_unlock(env.dst_rq, busiest);
local_irq_restore(flags);
- if (env.flags & LBF_NEED_BREAK) {
- env.flags &= ~LBF_NEED_BREAK;
- goto more_balance;
- }
-
/*
* some other cpu did the load balance for us.
*/
if (cur_ld_moved && env.dst_cpu != smp_processor_id())
resched_cpu(env.dst_cpu);
+ if (env.flags & LBF_NEED_BREAK) {
+ env.flags &= ~LBF_NEED_BREAK;
+ goto more_balance;
+ }
+
/*
* Revisit (affine) tasks on src_cpu that couldn't be moved to
* us and move them to an alternate dst_cpu in our sched_group
@@ -5092,14 +5115,17 @@ more_balance:
* moreover subsequent load balance cycles should correct the
* excess load moved.
*/
- if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0 &&
- lb_iterations++ < max_lb_iterations) {
+ if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) {
env.dst_rq = cpu_rq(env.new_dst_cpu);
env.dst_cpu = env.new_dst_cpu;
env.flags &= ~LBF_SOME_PINNED;
env.loop = 0;
env.loop_break = sched_nr_migrate_break;
+
+ /* Prevent to re-select dst_cpu via env's cpus */
+ cpumask_clear_cpu(env.dst_cpu, env.cpus);
+
/*
* Go back to "more_balance" rather than "redo" since we
* need to continue with same src_cpu.
@@ -5220,8 +5246,6 @@ void idle_balance(int this_cpu, struct rq *this_rq)
if (this_rq->avg_idle < sysctl_sched_migration_cost)
return;
- update_rq_runnable_avg(this_rq, 1);
-
/*
* Drop the rq->lock, but keep IRQ/preempt disabled.
*/
@@ -5396,13 +5420,16 @@ static inline void set_cpu_sd_state_busy(void)
struct sched_domain *sd;
int cpu = smp_processor_id();
- if (!test_bit(NOHZ_IDLE, nohz_flags(cpu)))
- return;
- clear_bit(NOHZ_IDLE, nohz_flags(cpu));
-
rcu_read_lock();
- for_each_domain(cpu, sd)
+ sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd);
+
+ if (!sd || !sd->nohz_idle)
+ goto unlock;
+ sd->nohz_idle = 0;
+
+ for (; sd; sd = sd->parent)
atomic_inc(&sd->groups->sgp->nr_busy_cpus);
+unlock:
rcu_read_unlock();
}
@@ -5411,13 +5438,16 @@ void set_cpu_sd_state_idle(void)
struct sched_domain *sd;
int cpu = smp_processor_id();
- if (test_bit(NOHZ_IDLE, nohz_flags(cpu)))
- return;
- set_bit(NOHZ_IDLE, nohz_flags(cpu));
-
rcu_read_lock();
- for_each_domain(cpu, sd)
+ sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd);
+
+ if (!sd || sd->nohz_idle)
+ goto unlock;
+ sd->nohz_idle = 1;
+
+ for (; sd; sd = sd->parent)
atomic_dec(&sd->groups->sgp->nr_busy_cpus);
+unlock:
rcu_read_unlock();
}
@@ -5469,7 +5499,7 @@ void update_max_interval(void)
* It checks each scheduling domain to see if it is due to be balanced,
* and initiates a balancing operation if so.
*
- * Balancing parameters are set up in arch_init_sched_domains.
+ * Balancing parameters are set up in init_sched_domains.
*/
static void rebalance_domains(int cpu, enum cpu_idle_type idle)
{
@@ -5507,10 +5537,11 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
if (time_after_eq(jiffies, sd->last_balance + interval)) {
if (load_balance(cpu, rq, sd, idle, &balance)) {
/*
- * We've pulled tasks over so either we're no
- * longer idle.
+ * The LBF_SOME_PINNED logic could have changed
+ * env->dst_cpu, so we can't know our idle
+ * state even if we migrated tasks. Update it.
*/
- idle = CPU_NOT_IDLE;
+ idle = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE;
}
sd->last_balance = jiffies;
}
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 1ad1d2b5395f..99399f8e4799 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -46,13 +46,6 @@ SCHED_FEAT(DOUBLE_TICK, false)
SCHED_FEAT(LB_BIAS, true)
/*
- * Spin-wait on mutex acquisition when the mutex owner is running on
- * another cpu -- assumes that when the owner is running, it will soon
- * release the lock. Decreases scheduling overhead.
- */
-SCHED_FEAT(OWNER_SPIN, true)
-
-/*
* Decrement CPU power based on time not spent running tasks
*/
SCHED_FEAT(NONTASK_POWER, true)
diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c
index b6baf370cae9..b8ce77328341 100644
--- a/kernel/sched/idle_task.c
+++ b/kernel/sched/idle_task.c
@@ -13,6 +13,16 @@ select_task_rq_idle(struct task_struct *p, int sd_flag, int flags)
{
return task_cpu(p); /* IDLE tasks as never migrated */
}
+
+static void pre_schedule_idle(struct rq *rq, struct task_struct *prev)
+{
+ idle_exit_fair(rq);
+}
+
+static void post_schedule_idle(struct rq *rq)
+{
+ idle_enter_fair(rq);
+}
#endif /* CONFIG_SMP */
/*
* Idle tasks are unconditionally rescheduled:
@@ -25,6 +35,10 @@ static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int fl
static struct task_struct *pick_next_task_idle(struct rq *rq)
{
schedstat_inc(rq, sched_goidle);
+#ifdef CONFIG_SMP
+ /* Trigger the post schedule to do an idle_enter for CFS */
+ rq->post_schedule = 1;
+#endif
return rq->idle;
}
@@ -86,6 +100,8 @@ const struct sched_class idle_sched_class = {
#ifdef CONFIG_SMP
.select_task_rq = select_task_rq_idle,
+ .pre_schedule = pre_schedule_idle,
+ .post_schedule = post_schedule_idle,
#endif
.set_curr_task = set_curr_task_idle,
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index eb363aa5d83c..24dc29897749 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -8,6 +8,7 @@
#include <linux/tick.h>
#include "cpupri.h"
+#include "cpuacct.h"
extern __read_mostly int scheduler_running;
@@ -951,14 +952,6 @@ static const u32 prio_to_wmult[40] = {
/* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
};
-/* Time spent by the tasks of the cpu accounting group executing in ... */
-enum cpuacct_stat_index {
- CPUACCT_STAT_USER, /* ... user mode */
- CPUACCT_STAT_SYSTEM, /* ... kernel mode */
-
- CPUACCT_STAT_NSTATS,
-};
-
#define ENQUEUE_WAKEUP 1
#define ENQUEUE_HEAD 2
#ifdef CONFIG_SMP
@@ -1032,6 +1025,18 @@ extern void update_group_power(struct sched_domain *sd, int cpu);
extern void trigger_load_balance(struct rq *rq, int cpu);
extern void idle_balance(int this_cpu, struct rq *this_rq);
+/*
+ * Only depends on SMP, FAIR_GROUP_SCHED may be removed when runnable_avg
+ * becomes useful in lb
+ */
+#if defined(CONFIG_FAIR_GROUP_SCHED)
+extern void idle_enter_fair(struct rq *this_rq);
+extern void idle_exit_fair(struct rq *this_rq);
+#else
+static inline void idle_enter_fair(struct rq *this_rq) {}
+static inline void idle_exit_fair(struct rq *this_rq) {}
+#endif
+
#else /* CONFIG_SMP */
static inline void idle_balance(int cpu, struct rq *rq)
@@ -1055,45 +1060,6 @@ extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime
extern void update_idle_cpu_load(struct rq *this_rq);
-#ifdef CONFIG_CGROUP_CPUACCT
-#include <linux/cgroup.h>
-/* track cpu usage of a group of tasks and its child groups */
-struct cpuacct {
- struct cgroup_subsys_state css;
- /* cpuusage holds pointer to a u64-type object on every cpu */
- u64 __percpu *cpuusage;
- struct kernel_cpustat __percpu *cpustat;
-};
-
-extern struct cgroup_subsys cpuacct_subsys;
-extern struct cpuacct root_cpuacct;
-
-/* return cpu accounting group corresponding to this container */
-static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)
-{
- return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id),
- struct cpuacct, css);
-}
-
-/* return cpu accounting group to which this task belongs */
-static inline struct cpuacct *task_ca(struct task_struct *tsk)
-{
- return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
- struct cpuacct, css);
-}
-
-static inline struct cpuacct *parent_ca(struct cpuacct *ca)
-{
- if (!ca || !ca->css.cgroup->parent)
- return NULL;
- return cgroup_ca(ca->css.cgroup->parent);
-}
-
-extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
-#else
-static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
-#endif
-
#ifdef CONFIG_PARAVIRT
static inline u64 steal_ticks(u64 steal)
{
@@ -1348,7 +1314,6 @@ extern void account_cfs_bandwidth_used(int enabled, int was_enabled);
enum rq_nohz_flag_bits {
NOHZ_TICK_STOPPED,
NOHZ_BALANCE_KICK,
- NOHZ_IDLE,
};
#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)