diff options
Diffstat (limited to 'kernel')
75 files changed, 4643 insertions, 2326 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index 85cbfb31e73e..e9cf19155b46 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -21,7 +21,6 @@ CFLAGS_REMOVE_mutex-debug.o = -pg CFLAGS_REMOVE_rtmutex-debug.o = -pg CFLAGS_REMOVE_cgroup-debug.o = -pg CFLAGS_REMOVE_sched_clock.o = -pg -CFLAGS_REMOVE_perf_event.o = -pg CFLAGS_REMOVE_irq_work.o = -pg endif @@ -103,8 +102,9 @@ obj-$(CONFIG_RING_BUFFER) += trace/ obj-$(CONFIG_TRACEPOINTS) += trace/ obj-$(CONFIG_SMP) += sched_cpupri.o obj-$(CONFIG_IRQ_WORK) += irq_work.o -obj-$(CONFIG_PERF_EVENTS) += perf_event.o -obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o + +obj-$(CONFIG_PERF_EVENTS) += events/ + obj-$(CONFIG_USER_RETURN_NOTIFIER) += user-return-notifier.o obj-$(CONFIG_PADATA) += padata.o obj-$(CONFIG_CRASH_DUMP) += crash_dump.o diff --git a/kernel/capability.c b/kernel/capability.c index bf0c734d0c12..32a80e08ff4b 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -399,3 +399,15 @@ bool task_ns_capable(struct task_struct *t, int cap) return ns_capable(task_cred_xxx(t, user)->user_ns, cap); } EXPORT_SYMBOL(task_ns_capable); + +/** + * nsown_capable - Check superior capability to one's own user_ns + * @cap: The capability in question + * + * Return true if the current task has the given superior capability + * targeted at its own user namespace. + */ +bool nsown_capable(int cap) +{ + return ns_capable(current_user_ns(), cap); +} diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 25c7eb52de1a..909a35510af5 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -326,12 +326,6 @@ static struct hlist_head *css_set_hash(struct cgroup_subsys_state *css[]) return &css_set_table[index]; } -static void free_css_set_rcu(struct rcu_head *obj) -{ - struct css_set *cg = container_of(obj, struct css_set, rcu_head); - kfree(cg); -} - /* We don't maintain the lists running through each css_set to its * task until after the first call to cgroup_iter_start(). This * reduces the fork()/exit() overhead for people who have cgroups @@ -375,7 +369,7 @@ static void __put_css_set(struct css_set *cg, int taskexit) } write_unlock(&css_set_lock); - call_rcu(&cg->rcu_head, free_css_set_rcu); + kfree_rcu(cg, rcu_head); } /* @@ -812,13 +806,6 @@ static int cgroup_call_pre_destroy(struct cgroup *cgrp) return ret; } -static void free_cgroup_rcu(struct rcu_head *obj) -{ - struct cgroup *cgrp = container_of(obj, struct cgroup, rcu_head); - - kfree(cgrp); -} - static void cgroup_diput(struct dentry *dentry, struct inode *inode) { /* is dentry a directory ? if so, kfree() associated cgroup */ @@ -856,7 +843,7 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode) */ BUG_ON(!list_empty(&cgrp->pidlists)); - call_rcu(&cgrp->rcu_head, free_cgroup_rcu); + kfree_rcu(cgrp, rcu_head); } iput(inode); } @@ -4623,14 +4610,6 @@ bool css_is_ancestor(struct cgroup_subsys_state *child, return ret; } -static void __free_css_id_cb(struct rcu_head *head) -{ - struct css_id *id; - - id = container_of(head, struct css_id, rcu_head); - kfree(id); -} - void free_css_id(struct cgroup_subsys *ss, struct cgroup_subsys_state *css) { struct css_id *id = css->id; @@ -4645,7 +4624,7 @@ void free_css_id(struct cgroup_subsys *ss, struct cgroup_subsys_state *css) spin_lock(&ss->id_lock); idr_remove(&ss->idr, id->id); spin_unlock(&ss->id_lock); - call_rcu(&id->rcu_head, __free_css_id_cb); + kfree_rcu(id, rcu_head); } EXPORT_SYMBOL_GPL(free_css_id); diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 33eee16addb8..2bb8c2e98fff 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1159,7 +1159,7 @@ int current_cpuset_is_being_rebound(void) static int update_relax_domain_level(struct cpuset *cs, s64 val) { #ifdef CONFIG_SMP - if (val < -1 || val >= SD_LV_MAX) + if (val < -1 || val >= sched_domain_level_max) return -EINVAL; #endif diff --git a/kernel/cred.c b/kernel/cred.c index 5557b55048df..8093c16b84b1 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -54,6 +54,7 @@ struct cred init_cred = { .cap_effective = CAP_INIT_EFF_SET, .cap_bset = CAP_INIT_BSET, .user = INIT_USER, + .user_ns = &init_user_ns, .group_info = &init_groups, #ifdef CONFIG_KEYS .tgcred = &init_tgcred, @@ -410,6 +411,11 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) goto error_put; } + /* cache user_ns in cred. Doesn't need a refcount because it will + * stay pinned by cred->user + */ + new->user_ns = new->user->user_ns; + #ifdef CONFIG_KEYS /* new threads get their own thread keyrings if their parent already * had one */ @@ -741,12 +747,6 @@ int set_create_files_as(struct cred *new, struct inode *inode) } EXPORT_SYMBOL(set_create_files_as); -struct user_namespace *current_user_ns(void) -{ - return _current_user_ns(); -} -EXPORT_SYMBOL(current_user_ns); - #ifdef CONFIG_DEBUG_CREDENTIALS bool creds_are_invalid(const struct cred *cred) diff --git a/kernel/events/Makefile b/kernel/events/Makefile new file mode 100644 index 000000000000..1ce23d3d8394 --- /dev/null +++ b/kernel/events/Makefile @@ -0,0 +1,6 @@ +ifdef CONFIG_FUNCTION_TRACER +CFLAGS_REMOVE_core.o = -pg +endif + +obj-y := core.o +obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o diff --git a/kernel/perf_event.c b/kernel/events/core.c index 8e81a9860a0d..c09767f7db3e 100644 --- a/kernel/perf_event.c +++ b/kernel/events/core.c @@ -2,8 +2,8 @@ * Performance events core code: * * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de> - * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar - * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> + * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar + * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com> * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> * * For licensing details see kernel-base/COPYING @@ -39,10 +39,10 @@ #include <asm/irq_regs.h> struct remote_function_call { - struct task_struct *p; - int (*func)(void *info); - void *info; - int ret; + struct task_struct *p; + int (*func)(void *info); + void *info; + int ret; }; static void remote_function(void *data) @@ -76,10 +76,10 @@ static int task_function_call(struct task_struct *p, int (*func) (void *info), void *info) { struct remote_function_call data = { - .p = p, - .func = func, - .info = info, - .ret = -ESRCH, /* No such (running) process */ + .p = p, + .func = func, + .info = info, + .ret = -ESRCH, /* No such (running) process */ }; if (task_curr(p)) @@ -100,10 +100,10 @@ task_function_call(struct task_struct *p, int (*func) (void *info), void *info) static int cpu_function_call(int cpu, int (*func) (void *info), void *info) { struct remote_function_call data = { - .p = NULL, - .func = func, - .info = info, - .ret = -ENXIO, /* No such CPU */ + .p = NULL, + .func = func, + .info = info, + .ret = -ENXIO, /* No such CPU */ }; smp_call_function_single(cpu, remote_function, &data, 1); @@ -125,7 +125,7 @@ enum event_type_t { * perf_sched_events : >0 events exist * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu */ -atomic_t perf_sched_events __read_mostly; +struct jump_label_key perf_sched_events __read_mostly; static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); static atomic_t nr_mmap_events __read_mostly; @@ -586,14 +586,6 @@ static void get_ctx(struct perf_event_context *ctx) WARN_ON(!atomic_inc_not_zero(&ctx->refcount)); } -static void free_ctx(struct rcu_head *head) -{ - struct perf_event_context *ctx; - - ctx = container_of(head, struct perf_event_context, rcu_head); - kfree(ctx); -} - static void put_ctx(struct perf_event_context *ctx) { if (atomic_dec_and_test(&ctx->refcount)) { @@ -601,7 +593,7 @@ static void put_ctx(struct perf_event_context *ctx) put_ctx(ctx->parent_ctx); if (ctx->task) put_task_struct(ctx->task); - call_rcu(&ctx->rcu_head, free_ctx); + kfree_rcu(ctx, rcu_head); } } @@ -5331,14 +5323,6 @@ swevent_hlist_deref(struct swevent_htable *swhash) lockdep_is_held(&swhash->hlist_mutex)); } -static void swevent_hlist_release_rcu(struct rcu_head *rcu_head) -{ - struct swevent_hlist *hlist; - - hlist = container_of(rcu_head, struct swevent_hlist, rcu_head); - kfree(hlist); -} - static void swevent_hlist_release(struct swevent_htable *swhash) { struct swevent_hlist *hlist = swevent_hlist_deref(swhash); @@ -5347,7 +5331,7 @@ static void swevent_hlist_release(struct swevent_htable *swhash) return; rcu_assign_pointer(swhash->swevent_hlist, NULL); - call_rcu(&hlist->rcu_head, swevent_hlist_release_rcu); + kfree_rcu(hlist, rcu_head); } static void swevent_hlist_put_cpu(struct perf_event *event, int cpu) @@ -5429,7 +5413,7 @@ fail: return err; } -atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX]; +struct jump_label_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; static void sw_perf_event_destroy(struct perf_event *event) { @@ -7445,11 +7429,11 @@ static void perf_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp, } struct cgroup_subsys perf_subsys = { - .name = "perf_event", - .subsys_id = perf_subsys_id, - .create = perf_cgroup_create, - .destroy = perf_cgroup_destroy, - .exit = perf_cgroup_exit, - .attach = perf_cgroup_attach, + .name = "perf_event", + .subsys_id = perf_subsys_id, + .create = perf_cgroup_create, + .destroy = perf_cgroup_destroy, + .exit = perf_cgroup_exit, + .attach = perf_cgroup_attach, }; #endif /* CONFIG_CGROUP_PERF */ diff --git a/kernel/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index 086adf25a55e..086adf25a55e 100644 --- a/kernel/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c diff --git a/kernel/exit.c b/kernel/exit.c index f5d2f63bae0b..8dd874181542 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1016,7 +1016,7 @@ NORET_TYPE void do_exit(long code) /* * FIXME: do that only when needed, using sched_exit tracepoint */ - flush_ptrace_hw_breakpoint(tsk); + ptrace_put_breakpoints(tsk); exit_notify(tsk, group_dead); #ifdef CONFIG_NUMA diff --git a/kernel/extable.c b/kernel/extable.c index 7f8f263f8524..c2d625fcda77 100644 --- a/kernel/extable.c +++ b/kernel/extable.c @@ -72,6 +72,14 @@ int core_kernel_text(unsigned long addr) return 0; } +int core_kernel_data(unsigned long addr) +{ + if (addr >= (unsigned long)_sdata && + addr < (unsigned long)_edata) + return 1; + return 0; +} + int __kernel_text_address(unsigned long addr) { if (core_kernel_text(addr)) diff --git a/kernel/fork.c b/kernel/fork.c index e7548dee636b..2b44d82b8237 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1103,7 +1103,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, posix_cpu_timers_init(p); - p->lock_depth = -1; /* -1 = no lock */ do_posix_clock_monotonic_gettime(&p->start_time); p->real_start_time = p->start_time; monotonic_to_bootbased(&p->real_start_time); @@ -1153,7 +1152,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, #endif /* Perform scheduler related setup. Assign this task to a CPU. */ - sched_fork(p, clone_flags); + sched_fork(p); retval = perf_event_init_task(p); if (retval) @@ -1464,7 +1463,7 @@ long do_fork(unsigned long clone_flags, */ p->flags &= ~PF_STARTING; - wake_up_new_task(p, clone_flags); + wake_up_new_task(p); tracehook_report_clone_complete(trace, regs, clone_flags, nr, p); diff --git a/kernel/freezer.c b/kernel/freezer.c index 66ecd2ead215..7b01de98bb6a 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -17,7 +17,7 @@ static inline void frozen_process(void) { if (!unlikely(current->flags & PF_NOFREEZE)) { current->flags |= PF_FROZEN; - wmb(); + smp_wmb(); } clear_freeze_flag(current); } @@ -93,7 +93,7 @@ bool freeze_task(struct task_struct *p, bool sig_only) * the task as frozen and next clears its TIF_FREEZE. */ if (!freezing(p)) { - rmb(); + smp_rmb(); if (frozen(p)) return false; diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 53ead174da2f..ea640120ab86 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -33,7 +33,7 @@ unsigned long __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT; /* * Zero means infinite timeout - no checking done: */ -unsigned long __read_mostly sysctl_hung_task_timeout_secs = 120; +unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_TASK_TIMEOUT; unsigned long __read_mostly sysctl_hung_task_warnings = 10; diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig index c574f9a12c48..d1d051b38e0b 100644 --- a/kernel/irq/Kconfig +++ b/kernel/irq/Kconfig @@ -48,6 +48,10 @@ config IRQ_PREFLOW_FASTEOI config IRQ_EDGE_EOI_HANDLER bool +# Generic configurable interrupt chip implementation +config GENERIC_IRQ_CHIP + bool + # Support forced irq threading config IRQ_FORCED_THREADING bool diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile index 54329cd7b3ee..73290056cfb6 100644 --- a/kernel/irq/Makefile +++ b/kernel/irq/Makefile @@ -1,5 +1,6 @@ obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o +obj-$(CONFIG_GENERIC_IRQ_CHIP) += generic-chip.o obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o obj-$(CONFIG_PROC_FS) += proc.o obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 4af1e2b244cb..d5a3009da71a 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -310,6 +310,7 @@ handle_simple_irq(unsigned int irq, struct irq_desc *desc) out_unlock: raw_spin_unlock(&desc->lock); } +EXPORT_SYMBOL_GPL(handle_simple_irq); /** * handle_level_irq - Level type irq handler @@ -573,6 +574,7 @@ __irq_set_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, if (handle != handle_bad_irq && is_chained) { irq_settings_set_noprobe(desc); irq_settings_set_norequest(desc); + irq_settings_set_nothread(desc); irq_startup(desc); } out: @@ -612,6 +614,7 @@ void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set) irq_put_desc_unlock(desc, flags); } +EXPORT_SYMBOL_GPL(irq_modify_status); /** * irq_cpu_online - Invoke all irq_cpu_online functions. diff --git a/kernel/irq/debug.h b/kernel/irq/debug.h index 306cba37e9a5..97a8bfadc88a 100644 --- a/kernel/irq/debug.h +++ b/kernel/irq/debug.h @@ -27,6 +27,7 @@ static inline void print_irq_desc(unsigned int irq, struct irq_desc *desc) P(IRQ_PER_CPU); P(IRQ_NOPROBE); P(IRQ_NOREQUEST); + P(IRQ_NOTHREAD); P(IRQ_NOAUTOEN); PS(IRQS_AUTODETECT); diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c new file mode 100644 index 000000000000..31a9db711906 --- /dev/null +++ b/kernel/irq/generic-chip.c @@ -0,0 +1,354 @@ +/* + * Library implementing the most common irq chip callback functions + * + * Copyright (C) 2011, Thomas Gleixner + */ +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <linux/kernel_stat.h> +#include <linux/syscore_ops.h> + +#include "internals.h" + +static LIST_HEAD(gc_list); +static DEFINE_RAW_SPINLOCK(gc_lock); + +static inline struct irq_chip_regs *cur_regs(struct irq_data *d) +{ + return &container_of(d->chip, struct irq_chip_type, chip)->regs; +} + +/** + * irq_gc_noop - NOOP function + * @d: irq_data + */ +void irq_gc_noop(struct irq_data *d) +{ +} + +/** + * irq_gc_mask_disable_reg - Mask chip via disable register + * @d: irq_data + * + * Chip has separate enable/disable registers instead of a single mask + * register. + */ +void irq_gc_mask_disable_reg(struct irq_data *d) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + u32 mask = 1 << (d->irq - gc->irq_base); + + irq_gc_lock(gc); + irq_reg_writel(mask, gc->reg_base + cur_regs(d)->disable); + gc->mask_cache &= ~mask; + irq_gc_unlock(gc); +} + +/** + * irq_gc_mask_set_mask_bit - Mask chip via setting bit in mask register + * @d: irq_data + * + * Chip has a single mask register. Values of this register are cached + * and protected by gc->lock + */ +void irq_gc_mask_set_bit(struct irq_data *d) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + u32 mask = 1 << (d->irq - gc->irq_base); + + irq_gc_lock(gc); + gc->mask_cache |= mask; + irq_reg_writel(gc->mask_cache, gc->reg_base + cur_regs(d)->mask); + irq_gc_unlock(gc); +} + +/** + * irq_gc_mask_set_mask_bit - Mask chip via clearing bit in mask register + * @d: irq_data + * + * Chip has a single mask register. Values of this register are cached + * and protected by gc->lock + */ +void irq_gc_mask_clr_bit(struct irq_data *d) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + u32 mask = 1 << (d->irq - gc->irq_base); + + irq_gc_lock(gc); + gc->mask_cache &= ~mask; + irq_reg_writel(gc->mask_cache, gc->reg_base + cur_regs(d)->mask); + irq_gc_unlock(gc); +} + +/** + * irq_gc_unmask_enable_reg - Unmask chip via enable register + * @d: irq_data + * + * Chip has separate enable/disable registers instead of a single mask + * register. + */ +void irq_gc_unmask_enable_reg(struct irq_data *d) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + u32 mask = 1 << (d->irq - gc->irq_base); + + irq_gc_lock(gc); + irq_reg_writel(mask, gc->reg_base + cur_regs(d)->enable); + gc->mask_cache |= mask; + irq_gc_unlock(gc); +} + +/** + * irq_gc_ack - Ack pending interrupt + * @d: irq_data + */ +void irq_gc_ack(struct irq_data *d) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + u32 mask = 1 << (d->irq - gc->irq_base); + + irq_gc_lock(gc); + irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack); + irq_gc_unlock(gc); +} + +/** + * irq_gc_mask_disable_reg_and_ack- Mask and ack pending interrupt + * @d: irq_data + */ +void irq_gc_mask_disable_reg_and_ack(struct irq_data *d) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + u32 mask = 1 << (d->irq - gc->irq_base); + + irq_gc_lock(gc); + irq_reg_writel(mask, gc->reg_base + cur_regs(d)->mask); + irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack); + irq_gc_unlock(gc); +} + +/** + * irq_gc_eoi - EOI interrupt + * @d: irq_data + */ +void irq_gc_eoi(struct irq_data *d) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + u32 mask = 1 << (d->irq - gc->irq_base); + + irq_gc_lock(gc); + irq_reg_writel(mask, gc->reg_base + cur_regs(d)->eoi); + irq_gc_unlock(gc); +} + +/** + * irq_gc_set_wake - Set/clr wake bit for an interrupt + * @d: irq_data + * + * For chips where the wake from suspend functionality is not + * configured in a separate register and the wakeup active state is + * just stored in a bitmask. + */ +int irq_gc_set_wake(struct irq_data *d, unsigned int on) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + u32 mask = 1 << (d->irq - gc->irq_base); + + if (!(mask & gc->wake_enabled)) + return -EINVAL; + + irq_gc_lock(gc); + if (on) + gc->wake_active |= mask; + else + gc->wake_active &= ~mask; + irq_gc_unlock(gc); + return 0; +} + +/** + * irq_alloc_generic_chip - Allocate a generic chip and initialize it + * @name: Name of the irq chip + * @num_ct: Number of irq_chip_type instances associated with this + * @irq_base: Interrupt base nr for this chip + * @reg_base: Register base address (virtual) + * @handler: Default flow handler associated with this chip + * + * Returns an initialized irq_chip_generic structure. The chip defaults + * to the primary (index 0) irq_chip_type and @handler + */ +struct irq_chip_generic * +irq_alloc_generic_chip(const char *name, int num_ct, unsigned int irq_base, + void __iomem *reg_base, irq_flow_handler_t handler) +{ + struct irq_chip_generic *gc; + unsigned long sz = sizeof(*gc) + num_ct * sizeof(struct irq_chip_type); + + gc = kzalloc(sz, GFP_KERNEL); + if (gc) { + raw_spin_lock_init(&gc->lock); + gc->num_ct = num_ct; + gc->irq_base = irq_base; + gc->reg_base = reg_base; + gc->chip_types->chip.name = name; + gc->chip_types->handler = handler; + } + return gc; +} + +/* + * Separate lockdep class for interrupt chip which can nest irq_desc + * lock. + */ +static struct lock_class_key irq_nested_lock_class; + +/** + * irq_setup_generic_chip - Setup a range of interrupts with a generic chip + * @gc: Generic irq chip holding all data + * @msk: Bitmask holding the irqs to initialize relative to gc->irq_base + * @flags: Flags for initialization + * @clr: IRQ_* bits to clear + * @set: IRQ_* bits to set + * + * Set up max. 32 interrupts starting from gc->irq_base. Note, this + * initializes all interrupts to the primary irq_chip_type and its + * associated handler. + */ +void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk, + enum irq_gc_flags flags, unsigned int clr, + unsigned int set) +{ + struct irq_chip_type *ct = gc->chip_types; + unsigned int i; + + raw_spin_lock(&gc_lock); + list_add_tail(&gc->list, &gc_list); + raw_spin_unlock(&gc_lock); + + /* Init mask cache ? */ + if (flags & IRQ_GC_INIT_MASK_CACHE) + gc->mask_cache = irq_reg_readl(gc->reg_base + ct->regs.mask); + + for (i = gc->irq_base; msk; msk >>= 1, i++) { + if (!msk & 0x01) + continue; + + if (flags & IRQ_GC_INIT_NESTED_LOCK) + irq_set_lockdep_class(i, &irq_nested_lock_class); + + irq_set_chip_and_handler(i, &ct->chip, ct->handler); + irq_set_chip_data(i, gc); + irq_modify_status(i, clr, set); + } + gc->irq_cnt = i - gc->irq_base; +} + +/** + * irq_setup_alt_chip - Switch to alternative chip + * @d: irq_data for this interrupt + * @type Flow type to be initialized + * + * Only to be called from chip->irq_set_type() callbacks. + */ +int irq_setup_alt_chip(struct irq_data *d, unsigned int type) +{ + struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d); + struct irq_chip_type *ct = gc->chip_types; + unsigned int i; + + for (i = 0; i < gc->num_ct; i++, ct++) { + if (ct->type & type) { + d->chip = &ct->chip; + irq_data_to_desc(d)->handle_irq = ct->handler; + return 0; + } + } + return -EINVAL; +} + +/** + * irq_remove_generic_chip - Remove a chip + * @gc: Generic irq chip holding all data + * @msk: Bitmask holding the irqs to initialize relative to gc->irq_base + * @clr: IRQ_* bits to clear + * @set: IRQ_* bits to set + * + * Remove up to 32 interrupts starting from gc->irq_base. + */ +void irq_remove_generic_chip(struct irq_chip_generic *gc, u32 msk, + unsigned int clr, unsigned int set) +{ + unsigned int i = gc->irq_base; + + raw_spin_lock(&gc_lock); + list_del(&gc->list); + raw_spin_unlock(&gc_lock); + + for (; msk; msk >>= 1, i++) { + if (!msk & 0x01) + continue; + + /* Remove handler first. That will mask the irq line */ + irq_set_handler(i, NULL); + irq_set_chip(i, &no_irq_chip); + irq_set_chip_data(i, NULL); + irq_modify_status(i, clr, set); + } +} + +#ifdef CONFIG_PM +static int irq_gc_suspend(void) +{ + struct irq_chip_generic *gc; + + list_for_each_entry(gc, &gc_list, list) { + struct irq_chip_type *ct = gc->chip_types; + + if (ct->chip.irq_suspend) + ct->chip.irq_suspend(irq_get_irq_data(gc->irq_base)); + } + return 0; +} + +static void irq_gc_resume(void) +{ + struct irq_chip_generic *gc; + + list_for_each_entry(gc, &gc_list, list) { + struct irq_chip_type *ct = gc->chip_types; + + if (ct->chip.irq_resume) + ct->chip.irq_resume(irq_get_irq_data(gc->irq_base)); + } +} +#else +#define irq_gc_suspend NULL +#define irq_gc_resume NULL +#endif + +static void irq_gc_shutdown(void) +{ + struct irq_chip_generic *gc; + + list_for_each_entry(gc, &gc_list, list) { + struct irq_chip_type *ct = gc->chip_types; + + if (ct->chip.irq_pm_shutdown) + ct->chip.irq_pm_shutdown(irq_get_irq_data(gc->irq_base)); + } +} + +static struct syscore_ops irq_gc_syscore_ops = { + .suspend = irq_gc_suspend, + .resume = irq_gc_resume, + .shutdown = irq_gc_shutdown, +}; + +static int __init irq_gc_init_ops(void) +{ + register_syscore_ops(&irq_gc_syscore_ops); + return 0; +} +device_initcall(irq_gc_init_ops); diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 2c039c9b9383..886e80347b32 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -22,7 +22,7 @@ */ static struct lock_class_key irq_desc_lock_class; -#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS) +#if defined(CONFIG_SMP) static void __init init_irq_default_affinity(void) { alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT); @@ -290,6 +290,22 @@ static int irq_expand_nr_irqs(unsigned int nr) #endif /* !CONFIG_SPARSE_IRQ */ +/** + * generic_handle_irq - Invoke the handler for a particular irq + * @irq: The irq number to handle + * + */ +int generic_handle_irq(unsigned int irq) +{ + struct irq_desc *desc = irq_to_desc(irq); + + if (!desc) + return -EINVAL; + generic_handle_irq_desc(irq, desc); + return 0; +} +EXPORT_SYMBOL_GPL(generic_handle_irq); + /* Dynamic interrupt handling */ /** @@ -311,6 +327,7 @@ void irq_free_descs(unsigned int from, unsigned int cnt) bitmap_clear(allocated_irqs, from, cnt); mutex_unlock(&sparse_irq_lock); } +EXPORT_SYMBOL_GPL(irq_free_descs); /** * irq_alloc_descs - allocate and initialize a range of irq descriptors @@ -351,6 +368,7 @@ err: mutex_unlock(&sparse_irq_lock); return ret; } +EXPORT_SYMBOL_GPL(irq_alloc_descs); /** * irq_reserve_irqs - mark irqs allocated @@ -430,7 +448,6 @@ unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) *per_cpu_ptr(desc->kstat_irqs, cpu) : 0; } -#ifdef CONFIG_GENERIC_HARDIRQS unsigned int kstat_irqs(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); @@ -443,4 +460,3 @@ unsigned int kstat_irqs(unsigned int irq) sum += *per_cpu_ptr(desc->kstat_irqs, cpu); return sum; } -#endif /* CONFIG_GENERIC_HARDIRQS */ diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 07c1611f3899..f7ce0021e1c4 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -900,7 +900,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) */ new->handler = irq_nested_primary_handler; } else { - irq_setup_forced_threading(new); + if (irq_settings_can_thread(desc)) + irq_setup_forced_threading(new); } /* diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index dd201bd35103..834899f2500f 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -419,7 +419,7 @@ int show_interrupts(struct seq_file *p, void *v) } else { seq_printf(p, " %8s", "None"); } -#ifdef CONFIG_GENIRC_IRQ_SHOW_LEVEL +#ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge"); #endif if (desc->name) diff --git a/kernel/irq/settings.h b/kernel/irq/settings.h index 0d91730b6330..f1667833d444 100644 --- a/kernel/irq/settings.h +++ b/kernel/irq/settings.h @@ -8,6 +8,7 @@ enum { _IRQ_LEVEL = IRQ_LEVEL, _IRQ_NOPROBE = IRQ_NOPROBE, _IRQ_NOREQUEST = IRQ_NOREQUEST, + _IRQ_NOTHREAD = IRQ_NOTHREAD, _IRQ_NOAUTOEN = IRQ_NOAUTOEN, _IRQ_MOVE_PCNTXT = IRQ_MOVE_PCNTXT, _IRQ_NO_BALANCING = IRQ_NO_BALANCING, @@ -20,6 +21,7 @@ enum { #define IRQ_LEVEL GOT_YOU_MORON #define IRQ_NOPROBE GOT_YOU_MORON #define IRQ_NOREQUEST GOT_YOU_MORON +#define IRQ_NOTHREAD GOT_YOU_MORON #define IRQ_NOAUTOEN GOT_YOU_MORON #define IRQ_NESTED_THREAD GOT_YOU_MORON #undef IRQF_MODIFY_MASK @@ -94,6 +96,21 @@ static inline void irq_settings_set_norequest(struct irq_desc *desc) desc->status_use_accessors |= _IRQ_NOREQUEST; } +static inline bool irq_settings_can_thread(struct irq_desc *desc) +{ + return !(desc->status_use_accessors & _IRQ_NOTHREAD); +} + +static inline void irq_settings_clr_nothread(struct irq_desc *desc) +{ + desc->status_use_accessors &= ~_IRQ_NOTHREAD; +} + +static inline void irq_settings_set_nothread(struct irq_desc *desc) +{ + desc->status_use_accessors |= _IRQ_NOTHREAD; +} + static inline bool irq_settings_can_probe(struct irq_desc *desc) { return !(desc->status_use_accessors & _IRQ_NOPROBE); diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 3b79bd938330..74d1c099fbd1 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -2,43 +2,23 @@ * jump label support * * Copyright (C) 2009 Jason Baron <jbaron@redhat.com> + * Copyright (C) 2011 Peter Zijlstra <pzijlstr@redhat.com> * */ -#include <linux/jump_label.h> #include <linux/memory.h> #include <linux/uaccess.h> #include <linux/module.h> #include <linux/list.h> -#include <linux/jhash.h> #include <linux/slab.h> #include <linux/sort.h> #include <linux/err.h> +#include <linux/jump_label.h> #ifdef HAVE_JUMP_LABEL -#define JUMP_LABEL_HASH_BITS 6 -#define JUMP_LABEL_TABLE_SIZE (1 << JUMP_LABEL_HASH_BITS) -static struct hlist_head jump_label_table[JUMP_LABEL_TABLE_SIZE]; - /* mutex to protect coming/going of the the jump_label table */ static DEFINE_MUTEX(jump_label_mutex); -struct jump_label_entry { - struct hlist_node hlist; - struct jump_entry *table; - int nr_entries; - /* hang modules off here */ - struct hlist_head modules; - unsigned long key; -}; - -struct jump_label_module_entry { - struct hlist_node hlist; - struct jump_entry *table; - int nr_entries; - struct module *mod; -}; - void jump_label_lock(void) { mutex_lock(&jump_label_mutex); @@ -49,6 +29,11 @@ void jump_label_unlock(void) mutex_unlock(&jump_label_mutex); } +bool jump_label_enabled(struct jump_label_key *key) +{ + return !!atomic_read(&key->enabled); +} + static int jump_label_cmp(const void *a, const void *b) { const struct jump_entry *jea = a; @@ -64,7 +49,7 @@ static int jump_label_cmp(const void *a, const void *b) } static void -sort_jump_label_entries(struct jump_entry *start, struct jump_entry *stop) +jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop) { unsigned long size; @@ -73,118 +58,25 @@ sort_jump_label_entries(struct jump_entry *start, struct jump_entry *stop) sort(start, size, sizeof(struct jump_entry), jump_label_cmp, NULL); } -static struct jump_label_entry *get_jump_label_entry(jump_label_t key) -{ - struct hlist_head *head; - struct hlist_node *node; - struct jump_label_entry *e; - u32 hash = jhash((void *)&key, sizeof(jump_label_t), 0); - - head = &jump_label_table[hash & (JUMP_LABEL_TABLE_SIZE - 1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (key == e->key) - return e; - } - return NULL; -} +static void jump_label_update(struct jump_label_key *key, int enable); -static struct jump_label_entry * -add_jump_label_entry(jump_label_t key, int nr_entries, struct jump_entry *table) +void jump_label_inc(struct jump_label_key *key) { - struct hlist_head *head; - struct jump_label_entry *e; - u32 hash; - - e = get_jump_label_entry(key); - if (e) - return ERR_PTR(-EEXIST); - - e = kmalloc(sizeof(struct jump_label_entry), GFP_KERNEL); - if (!e) - return ERR_PTR(-ENOMEM); - - hash = jhash((void *)&key, sizeof(jump_label_t), 0); - head = &jump_label_table[hash & (JUMP_LABEL_TABLE_SIZE - 1)]; - e->key = key; - e->table = table; - e->nr_entries = nr_entries; - INIT_HLIST_HEAD(&(e->modules)); - hlist_add_head(&e->hlist, head); - return e; -} + if (atomic_inc_not_zero(&key->enabled)) + return; -static int -build_jump_label_hashtable(struct jump_entry *start, struct jump_entry *stop) -{ - struct jump_entry *iter, *iter_begin; - struct jump_label_entry *entry; - int count; - - sort_jump_label_entries(start, stop); - iter = start; - while (iter < stop) { - entry = get_jump_label_entry(iter->key); - if (!entry) { - iter_begin = iter; - count = 0; - while ((iter < stop) && - (iter->key == iter_begin->key)) { - iter++; - count++; - } - entry = add_jump_label_entry(iter_begin->key, - count, iter_begin); - if (IS_ERR(entry)) - return PTR_ERR(entry); - } else { - WARN_ONCE(1, KERN_ERR "build_jump_hashtable: unexpected entry!\n"); - return -1; - } - } - return 0; + jump_label_lock(); + if (atomic_add_return(1, &key->enabled) == 1) + jump_label_update(key, JUMP_LABEL_ENABLE); + jump_label_unlock(); } -/*** - * jump_label_update - update jump label text - * @key - key value associated with a a jump label - * @type - enum set to JUMP_LABEL_ENABLE or JUMP_LABEL_DISABLE - * - * Will enable/disable the jump for jump label @key, depending on the - * value of @type. - * - */ - -void jump_label_update(unsigned long key, enum jump_label_type type) +void jump_label_dec(struct jump_label_key *key) { - struct jump_entry *iter; - struct jump_label_entry *entry; - struct hlist_node *module_node; - struct jump_label_module_entry *e_module; - int count; + if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) + return; - jump_label_lock(); - entry = get_jump_label_entry((jump_label_t)key); - if (entry) { - count = entry->nr_entries; - iter = entry->table; - while (count--) { - if (kernel_text_address(iter->code)) - arch_jump_label_transform(iter, type); - iter++; - } - /* eanble/disable jump labels in modules */ - hlist_for_each_entry(e_module, module_node, &(entry->modules), - hlist) { - count = e_module->nr_entries; - iter = e_module->table; - while (count--) { - if (iter->key && - kernel_text_address(iter->code)) - arch_jump_label_transform(iter, type); - iter++; - } - } - } + jump_label_update(key, JUMP_LABEL_DISABLE); jump_label_unlock(); } @@ -197,77 +89,33 @@ static int addr_conflict(struct jump_entry *entry, void *start, void *end) return 0; } -#ifdef CONFIG_MODULES - -static int module_conflict(void *start, void *end) +static int __jump_label_text_reserved(struct jump_entry *iter_start, + struct jump_entry *iter_stop, void *start, void *end) { - struct hlist_head *head; - struct hlist_node *node, *node_next, *module_node, *module_node_next; - struct jump_label_entry *e; - struct jump_label_module_entry *e_module; struct jump_entry *iter; - int i, count; - int conflict = 0; - - for (i = 0; i < JUMP_LABEL_TABLE_SIZE; i++) { - head = &jump_label_table[i]; - hlist_for_each_entry_safe(e, node, node_next, head, hlist) { - hlist_for_each_entry_safe(e_module, module_node, - module_node_next, - &(e->modules), hlist) { - count = e_module->nr_entries; - iter = e_module->table; - while (count--) { - if (addr_conflict(iter, start, end)) { - conflict = 1; - goto out; - } - iter++; - } - } - } - } -out: - return conflict; -} - -#endif - -/*** - * jump_label_text_reserved - check if addr range is reserved - * @start: start text addr - * @end: end text addr - * - * checks if the text addr located between @start and @end - * overlaps with any of the jump label patch addresses. Code - * that wants to modify kernel text should first verify that - * it does not overlap with any of the jump label addresses. - * Caller must hold jump_label_mutex. - * - * returns 1 if there is an overlap, 0 otherwise - */ -int jump_label_text_reserved(void *start, void *end) -{ - struct jump_entry *iter; - struct jump_entry *iter_start = __start___jump_table; - struct jump_entry *iter_stop = __start___jump_table; - int conflict = 0; iter = iter_start; while (iter < iter_stop) { - if (addr_conflict(iter, start, end)) { - conflict = 1; - goto out; - } + if (addr_conflict(iter, start, end)) + return 1; iter++; } - /* now check modules */ -#ifdef CONFIG_MODULES - conflict = module_conflict(start, end); -#endif -out: - return conflict; + return 0; +} + +static void __jump_label_update(struct jump_label_key *key, + struct jump_entry *entry, int enable) +{ + for (; entry->key == (jump_label_t)(unsigned long)key; entry++) { + /* + * entry->code set to 0 invalidates module init text sections + * kernel_text_address() verifies we are not in core kernel + * init code, see jump_label_invalidate_module_init(). + */ + if (entry->code && kernel_text_address(entry->code)) + arch_jump_label_transform(entry, enable); + } } /* @@ -277,142 +125,173 @@ void __weak arch_jump_label_text_poke_early(jump_label_t addr) { } -static __init int init_jump_label(void) +static __init int jump_label_init(void) { - int ret; struct jump_entry *iter_start = __start___jump_table; struct jump_entry *iter_stop = __stop___jump_table; + struct jump_label_key *key = NULL; struct jump_entry *iter; jump_label_lock(); - ret = build_jump_label_hashtable(__start___jump_table, - __stop___jump_table); - iter = iter_start; - while (iter < iter_stop) { + jump_label_sort_entries(iter_start, iter_stop); + + for (iter = iter_start; iter < iter_stop; iter++) { arch_jump_label_text_poke_early(iter->code); - iter++; + if (iter->key == (jump_label_t)(unsigned long)key) + continue; + + key = (struct jump_label_key *)(unsigned long)iter->key; + atomic_set(&key->enabled, 0); + key->entries = iter; +#ifdef CONFIG_MODULES + key->next = NULL; +#endif } jump_label_unlock(); - return ret; + + return 0; } -early_initcall(init_jump_label); +early_initcall(jump_label_init); #ifdef CONFIG_MODULES -static struct jump_label_module_entry * -add_jump_label_module_entry(struct jump_label_entry *entry, - struct jump_entry *iter_begin, - int count, struct module *mod) +struct jump_label_mod { + struct jump_label_mod *next; + struct jump_entry *entries; + struct module *mod; +}; + +static int __jump_label_mod_text_reserved(void *start, void *end) +{ + struct module *mod; + + mod = __module_text_address((unsigned long)start); + if (!mod) + return 0; + + WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod); + + return __jump_label_text_reserved(mod->jump_entries, + mod->jump_entries + mod->num_jump_entries, + start, end); +} + +static void __jump_label_mod_update(struct jump_label_key *key, int enable) +{ + struct jump_label_mod *mod = key->next; + + while (mod) { + __jump_label_update(key, mod->entries, enable); + mod = mod->next; + } +} + +/*** + * apply_jump_label_nops - patch module jump labels with arch_get_jump_label_nop() + * @mod: module to patch + * + * Allow for run-time selection of the optimal nops. Before the module + * loads patch these with arch_get_jump_label_nop(), which is specified by + * the arch specific jump label code. + */ +void jump_label_apply_nops(struct module *mod) { - struct jump_label_module_entry *e; - - e = kmalloc(sizeof(struct jump_label_module_entry), GFP_KERNEL); - if (!e) - return ERR_PTR(-ENOMEM); - e->mod = mod; - e->nr_entries = count; - e->table = iter_begin; - hlist_add_head(&e->hlist, &entry->modules); - return e; + struct jump_entry *iter_start = mod->jump_entries; + struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; + struct jump_entry *iter; + + /* if the module doesn't have jump label entries, just return */ + if (iter_start == iter_stop) + return; + + for (iter = iter_start; iter < iter_stop; iter++) + arch_jump_label_text_poke_early(iter->code); } -static int add_jump_label_module(struct module *mod) +static int jump_label_add_module(struct module *mod) { - struct jump_entry *iter, *iter_begin; - struct jump_label_entry *entry; - struct jump_label_module_entry *module_entry; - int count; + struct jump_entry *iter_start = mod->jump_entries; + struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; + struct jump_entry *iter; + struct jump_label_key *key = NULL; + struct jump_label_mod *jlm; /* if the module doesn't have jump label entries, just return */ - if (!mod->num_jump_entries) + if (iter_start == iter_stop) return 0; - sort_jump_label_entries(mod->jump_entries, - mod->jump_entries + mod->num_jump_entries); - iter = mod->jump_entries; - while (iter < mod->jump_entries + mod->num_jump_entries) { - entry = get_jump_label_entry(iter->key); - iter_begin = iter; - count = 0; - while ((iter < mod->jump_entries + mod->num_jump_entries) && - (iter->key == iter_begin->key)) { - iter++; - count++; - } - if (!entry) { - entry = add_jump_label_entry(iter_begin->key, 0, NULL); - if (IS_ERR(entry)) - return PTR_ERR(entry); + jump_label_sort_entries(iter_start, iter_stop); + + for (iter = iter_start; iter < iter_stop; iter++) { + if (iter->key == (jump_label_t)(unsigned long)key) + continue; + + key = (struct jump_label_key *)(unsigned long)iter->key; + + if (__module_address(iter->key) == mod) { + atomic_set(&key->enabled, 0); + key->entries = iter; + key->next = NULL; + continue; } - module_entry = add_jump_label_module_entry(entry, iter_begin, - count, mod); - if (IS_ERR(module_entry)) - return PTR_ERR(module_entry); + + jlm = kzalloc(sizeof(struct jump_label_mod), GFP_KERNEL); + if (!jlm) + return -ENOMEM; + + jlm->mod = mod; + jlm->entries = iter; + jlm->next = key->next; + key->next = jlm; + + if (jump_label_enabled(key)) + __jump_label_update(key, iter, JUMP_LABEL_ENABLE); } + return 0; } -static void remove_jump_label_module(struct module *mod) +static void jump_label_del_module(struct module *mod) { - struct hlist_head *head; - struct hlist_node *node, *node_next, *module_node, *module_node_next; - struct jump_label_entry *e; - struct jump_label_module_entry *e_module; - int i; + struct jump_entry *iter_start = mod->jump_entries; + struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; + struct jump_entry *iter; + struct jump_label_key *key = NULL; + struct jump_label_mod *jlm, **prev; - /* if the module doesn't have jump label entries, just return */ - if (!mod->num_jump_entries) - return; + for (iter = iter_start; iter < iter_stop; iter++) { + if (iter->key == (jump_label_t)(unsigned long)key) + continue; + + key = (struct jump_label_key *)(unsigned long)iter->key; + + if (__module_address(iter->key) == mod) + continue; + + prev = &key->next; + jlm = key->next; - for (i = 0; i < JUMP_LABEL_TABLE_SIZE; i++) { - head = &jump_label_table[i]; - hlist_for_each_entry_safe(e, node, node_next, head, hlist) { - hlist_for_each_entry_safe(e_module, module_node, - module_node_next, - &(e->modules), hlist) { - if (e_module->mod == mod) { - hlist_del(&e_module->hlist); - kfree(e_module); - } - } - if (hlist_empty(&e->modules) && (e->nr_entries == 0)) { - hlist_del(&e->hlist); - kfree(e); - } + while (jlm && jlm->mod != mod) { + prev = &jlm->next; + jlm = jlm->next; + } + + if (jlm) { + *prev = jlm->next; + kfree(jlm); } } } -static void remove_jump_label_module_init(struct module *mod) +static void jump_label_invalidate_module_init(struct module *mod) { - struct hlist_head *head; - struct hlist_node *node, *node_next, *module_node, *module_node_next; - struct jump_label_entry *e; - struct jump_label_module_entry *e_module; + struct jump_entry *iter_start = mod->jump_entries; + struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; struct jump_entry *iter; - int i, count; - - /* if the module doesn't have jump label entries, just return */ - if (!mod->num_jump_entries) - return; - for (i = 0; i < JUMP_LABEL_TABLE_SIZE; i++) { - head = &jump_label_table[i]; - hlist_for_each_entry_safe(e, node, node_next, head, hlist) { - hlist_for_each_entry_safe(e_module, module_node, - module_node_next, - &(e->modules), hlist) { - if (e_module->mod != mod) - continue; - count = e_module->nr_entries; - iter = e_module->table; - while (count--) { - if (within_module_init(iter->code, mod)) - iter->key = 0; - iter++; - } - } - } + for (iter = iter_start; iter < iter_stop; iter++) { + if (within_module_init(iter->code, mod)) + iter->code = 0; } } @@ -426,59 +305,77 @@ jump_label_module_notify(struct notifier_block *self, unsigned long val, switch (val) { case MODULE_STATE_COMING: jump_label_lock(); - ret = add_jump_label_module(mod); + ret = jump_label_add_module(mod); if (ret) - remove_jump_label_module(mod); + jump_label_del_module(mod); jump_label_unlock(); break; case MODULE_STATE_GOING: jump_label_lock(); - remove_jump_label_module(mod); + jump_label_del_module(mod); jump_label_unlock(); break; case MODULE_STATE_LIVE: jump_label_lock(); - remove_jump_label_module_init(mod); + jump_label_invalidate_module_init(mod); jump_label_unlock(); break; } - return ret; -} -/*** - * apply_jump_label_nops - patch module jump labels with arch_get_jump_label_nop() - * @mod: module to patch - * - * Allow for run-time selection of the optimal nops. Before the module - * loads patch these with arch_get_jump_label_nop(), which is specified by - * the arch specific jump label code. - */ -void jump_label_apply_nops(struct module *mod) -{ - struct jump_entry *iter; - - /* if the module doesn't have jump label entries, just return */ - if (!mod->num_jump_entries) - return; - - iter = mod->jump_entries; - while (iter < mod->jump_entries + mod->num_jump_entries) { - arch_jump_label_text_poke_early(iter->code); - iter++; - } + return notifier_from_errno(ret); } struct notifier_block jump_label_module_nb = { .notifier_call = jump_label_module_notify, - .priority = 0, + .priority = 1, /* higher than tracepoints */ }; -static __init int init_jump_label_module(void) +static __init int jump_label_init_module(void) { return register_module_notifier(&jump_label_module_nb); } -early_initcall(init_jump_label_module); +early_initcall(jump_label_init_module); #endif /* CONFIG_MODULES */ +/*** + * jump_label_text_reserved - check if addr range is reserved + * @start: start text addr + * @end: end text addr + * + * checks if the text addr located between @start and @end + * overlaps with any of the jump label patch addresses. Code + * that wants to modify kernel text should first verify that + * it does not overlap with any of the jump label addresses. + * Caller must hold jump_label_mutex. + * + * returns 1 if there is an overlap, 0 otherwise + */ +int jump_label_text_reserved(void *start, void *end) +{ + int ret = __jump_label_text_reserved(__start___jump_table, + __stop___jump_table, start, end); + + if (ret) + return ret; + +#ifdef CONFIG_MODULES + ret = __jump_label_mod_text_reserved(start, end); +#endif + return ret; +} + +static void jump_label_update(struct jump_label_key *key, int enable) +{ + struct jump_entry *entry = key->entries; + + /* if there are no users, entry can be NULL */ + if (entry) + __jump_label_update(key, entry, enable); + +#ifdef CONFIG_MODULES + __jump_label_mod_update(key, enable); +#endif +} + #endif diff --git a/kernel/kexec.c b/kernel/kexec.c index 87b77de03dd3..8d814cbc8109 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -1531,13 +1531,7 @@ int kernel_kexec(void) if (error) goto Enable_cpus; local_irq_disable(); - /* Suspend system devices */ - error = sysdev_suspend(PMSG_FREEZE); - if (!error) { - error = syscore_suspend(); - if (error) - sysdev_resume(); - } + error = syscore_suspend(); if (error) goto Enable_irqs; } else @@ -1553,7 +1547,6 @@ int kernel_kexec(void) #ifdef CONFIG_KEXEC_JUMP if (kexec_image->preserve_context) { syscore_resume(); - sysdev_resume(); Enable_irqs: local_irq_enable(); Enable_cpus: diff --git a/kernel/kmod.c b/kernel/kmod.c index 9cd0591c96a2..5ae0ff38425f 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -245,7 +245,6 @@ static void __call_usermodehelper(struct work_struct *work) } } -#ifdef CONFIG_PM_SLEEP /* * If set, call_usermodehelper_exec() will exit immediately returning -EBUSY * (used for preventing user land processes from being created after the user @@ -301,6 +300,15 @@ void usermodehelper_enable(void) usermodehelper_disabled = 0; } +/** + * usermodehelper_is_disabled - check if new helpers are allowed to be started + */ +bool usermodehelper_is_disabled(void) +{ + return usermodehelper_disabled; +} +EXPORT_SYMBOL_GPL(usermodehelper_is_disabled); + static void helper_lock(void) { atomic_inc(&running_helpers); @@ -312,12 +320,6 @@ static void helper_unlock(void) if (atomic_dec_and_test(&running_helpers)) wake_up(&running_helpers_waitq); } -#else /* CONFIG_PM_SLEEP */ -#define usermodehelper_disabled 0 - -static inline void helper_lock(void) {} -static inline void helper_unlock(void) {} -#endif /* CONFIG_PM_SLEEP */ /** * call_usermodehelper_setup - prepare to call a usermode helper diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index 0b624e791805..3b053c04dd86 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -16,6 +16,7 @@ #include <linux/kexec.h> #include <linux/profile.h> #include <linux/sched.h> +#include <linux/capability.h> #define KERNEL_ATTR_RO(_name) \ static struct kobj_attribute _name##_attr = __ATTR_RO(_name) @@ -131,6 +132,14 @@ KERNEL_ATTR_RO(vmcoreinfo); #endif /* CONFIG_KEXEC */ +/* whether file capabilities are enabled */ +static ssize_t fscaps_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", file_caps_enabled); +} +KERNEL_ATTR_RO(fscaps); + /* * Make /sys/kernel/notes give the raw contents of our kernel .notes section. */ @@ -158,6 +167,7 @@ struct kobject *kernel_kobj; EXPORT_SYMBOL_GPL(kernel_kobj); static struct attribute * kernel_attrs[] = { + &fscaps_attr.attr, #if defined(CONFIG_HOTPLUG) &uevent_seqnum_attr.attr, &uevent_helper_attr.attr, diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 53a68956f131..63437d065ac8 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -490,6 +490,18 @@ void get_usage_chars(struct lock_class *class, char usage[LOCK_USAGE_CHARS]) usage[i] = '\0'; } +static int __print_lock_name(struct lock_class *class) +{ + char str[KSYM_NAME_LEN]; + const char *name; + + name = class->name; + if (!name) + name = __get_key_name(class->key, str); + + return printk("%s", name); +} + static void print_lock_name(struct lock_class *class) { char str[KSYM_NAME_LEN], usage[LOCK_USAGE_CHARS]; @@ -1053,6 +1065,56 @@ print_circular_bug_entry(struct lock_list *target, int depth) return 0; } +static void +print_circular_lock_scenario(struct held_lock *src, + struct held_lock *tgt, + struct lock_list *prt) +{ + struct lock_class *source = hlock_class(src); + struct lock_class *target = hlock_class(tgt); + struct lock_class *parent = prt->class; + + /* + * A direct locking problem where unsafe_class lock is taken + * directly by safe_class lock, then all we need to show + * is the deadlock scenario, as it is obvious that the + * unsafe lock is taken under the safe lock. + * + * But if there is a chain instead, where the safe lock takes + * an intermediate lock (middle_class) where this lock is + * not the same as the safe lock, then the lock chain is + * used to describe the problem. Otherwise we would need + * to show a different CPU case for each link in the chain + * from the safe_class lock to the unsafe_class lock. + */ + if (parent != source) { + printk("Chain exists of:\n "); + __print_lock_name(source); + printk(" --> "); + __print_lock_name(parent); + printk(" --> "); + __print_lock_name(target); + printk("\n\n"); + } + + printk(" Possible unsafe locking scenario:\n\n"); + printk(" CPU0 CPU1\n"); + printk(" ---- ----\n"); + printk(" lock("); + __print_lock_name(target); + printk(");\n"); + printk(" lock("); + __print_lock_name(parent); + printk(");\n"); + printk(" lock("); + __print_lock_name(target); + printk(");\n"); + printk(" lock("); + __print_lock_name(source); + printk(");\n"); + printk("\n *** DEADLOCK ***\n\n"); +} + /* * When a circular dependency is detected, print the * header first: @@ -1096,6 +1158,7 @@ static noinline int print_circular_bug(struct lock_list *this, { struct task_struct *curr = current; struct lock_list *parent; + struct lock_list *first_parent; int depth; if (!debug_locks_off_graph_unlock() || debug_locks_silent) @@ -1109,6 +1172,7 @@ static noinline int print_circular_bug(struct lock_list *this, print_circular_bug_header(target, depth, check_src, check_tgt); parent = get_lock_parent(target); + first_parent = parent; while (parent) { print_circular_bug_entry(parent, --depth); @@ -1116,6 +1180,9 @@ static noinline int print_circular_bug(struct lock_list *this, } printk("\nother info that might help us debug this:\n\n"); + print_circular_lock_scenario(check_src, check_tgt, + first_parent); + lockdep_print_held_locks(curr); printk("\nstack backtrace:\n"); @@ -1314,7 +1381,7 @@ print_shortest_lock_dependencies(struct lock_list *leaf, printk("\n"); if (depth == 0 && (entry != root)) { - printk("lockdep:%s bad BFS generated tree\n", __func__); + printk("lockdep:%s bad path found in chain graph\n", __func__); break; } @@ -1325,6 +1392,62 @@ print_shortest_lock_dependencies(struct lock_list *leaf, return; } +static void +print_irq_lock_scenario(struct lock_list *safe_entry, + struct lock_list *unsafe_entry, + struct lock_class *prev_class, + struct lock_class *next_class) +{ + struct lock_class *safe_class = safe_entry->class; + struct lock_class *unsafe_class = unsafe_entry->class; + struct lock_class *middle_class = prev_class; + + if (middle_class == safe_class) + middle_class = next_class; + + /* + * A direct locking problem where unsafe_class lock is taken + * directly by safe_class lock, then all we need to show + * is the deadlock scenario, as it is obvious that the + * unsafe lock is taken under the safe lock. + * + * But if there is a chain instead, where the safe lock takes + * an intermediate lock (middle_class) where this lock is + * not the same as the safe lock, then the lock chain is + * used to describe the problem. Otherwise we would need + * to show a different CPU case for each link in the chain + * from the safe_class lock to the unsafe_class lock. + */ + if (middle_class != unsafe_class) { + printk("Chain exists of:\n "); + __print_lock_name(safe_class); + printk(" --> "); + __print_lock_name(middle_class); + printk(" --> "); + __print_lock_name(unsafe_class); + printk("\n\n"); + } + + printk(" Possible interrupt unsafe locking scenario:\n\n"); + printk(" CPU0 CPU1\n"); + printk(" ---- ----\n"); + printk(" lock("); + __print_lock_name(unsafe_class); + printk(");\n"); + printk(" local_irq_disable();\n"); + printk(" lock("); + __print_lock_name(safe_class); + printk(");\n"); + printk(" lock("); + __print_lock_name(middle_class); + printk(");\n"); + printk(" <Interrupt>\n"); + printk(" lock("); + __print_lock_name(safe_class); + printk(");\n"); + printk("\n *** DEADLOCK ***\n\n"); +} + static int print_bad_irq_dependency(struct task_struct *curr, struct lock_list *prev_root, @@ -1376,6 +1499,9 @@ print_bad_irq_dependency(struct task_struct *curr, print_stack_trace(forwards_entry->class->usage_traces + bit2, 1); printk("\nother info that might help us debug this:\n\n"); + print_irq_lock_scenario(backwards_entry, forwards_entry, + hlock_class(prev), hlock_class(next)); + lockdep_print_held_locks(curr); printk("\nthe dependencies between %s-irq-safe lock", irqclass); @@ -1539,6 +1665,26 @@ static inline void inc_chains(void) #endif +static void +print_deadlock_scenario(struct held_lock *nxt, + struct held_lock *prv) +{ + struct lock_class *next = hlock_class(nxt); + struct lock_class *prev = hlock_class(prv); + + printk(" Possible unsafe locking scenario:\n\n"); + printk(" CPU0\n"); + printk(" ----\n"); + printk(" lock("); + __print_lock_name(prev); + printk(");\n"); + printk(" lock("); + __print_lock_name(next); + printk(");\n"); + printk("\n *** DEADLOCK ***\n\n"); + printk(" May be due to missing lock nesting notation\n\n"); +} + static int print_deadlock_bug(struct task_struct *curr, struct held_lock *prev, struct held_lock *next) @@ -1557,6 +1703,7 @@ print_deadlock_bug(struct task_struct *curr, struct held_lock *prev, print_lock(prev); printk("\nother info that might help us debug this:\n"); + print_deadlock_scenario(next, prev); lockdep_print_held_locks(curr); printk("\nstack backtrace:\n"); @@ -1826,7 +1973,7 @@ static inline int lookup_chain_cache(struct task_struct *curr, struct list_head *hash_head = chainhashentry(chain_key); struct lock_chain *chain; struct held_lock *hlock_curr, *hlock_next; - int i, j, n, cn; + int i, j; if (DEBUG_LOCKS_WARN_ON(!irqs_disabled())) return 0; @@ -1886,15 +2033,9 @@ cache_hit: } i++; chain->depth = curr->lockdep_depth + 1 - i; - cn = nr_chain_hlocks; - while (cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS) { - n = cmpxchg(&nr_chain_hlocks, cn, cn + chain->depth); - if (n == cn) - break; - cn = n; - } - if (likely(cn + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) { - chain->base = cn; + if (likely(nr_chain_hlocks + chain->depth <= MAX_LOCKDEP_CHAIN_HLOCKS)) { + chain->base = nr_chain_hlocks; + nr_chain_hlocks += chain->depth; for (j = 0; j < chain->depth - 1; j++, i++) { int lock_id = curr->held_locks[i].class_idx - 1; chain_hlocks[chain->base + j] = lock_id; @@ -2011,6 +2152,24 @@ static void check_chain_key(struct task_struct *curr) #endif } +static void +print_usage_bug_scenario(struct held_lock *lock) +{ + struct lock_class *class = hlock_class(lock); + + printk(" Possible unsafe locking scenario:\n\n"); + printk(" CPU0\n"); + printk(" ----\n"); + printk(" lock("); + __print_lock_name(class); + printk(");\n"); + printk(" <Interrupt>\n"); + printk(" lock("); + __print_lock_name(class); + printk(");\n"); + printk("\n *** DEADLOCK ***\n\n"); +} + static int print_usage_bug(struct task_struct *curr, struct held_lock *this, enum lock_usage_bit prev_bit, enum lock_usage_bit new_bit) @@ -2039,6 +2198,8 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this, print_irqtrace_events(curr); printk("\nother info that might help us debug this:\n"); + print_usage_bug_scenario(this); + lockdep_print_held_locks(curr); printk("\nstack backtrace:\n"); @@ -2073,6 +2234,10 @@ print_irq_inversion_bug(struct task_struct *curr, struct held_lock *this, int forwards, const char *irqclass) { + struct lock_list *entry = other; + struct lock_list *middle = NULL; + int depth; + if (!debug_locks_off_graph_unlock() || debug_locks_silent) return 0; @@ -2091,6 +2256,25 @@ print_irq_inversion_bug(struct task_struct *curr, printk("\n\nand interrupts could create inverse lock ordering between them.\n\n"); printk("\nother info that might help us debug this:\n"); + + /* Find a middle lock (if one exists) */ + depth = get_lock_depth(other); + do { + if (depth == 0 && (entry != root)) { + printk("lockdep:%s bad path found in chain graph\n", __func__); + break; + } + middle = entry; + entry = get_lock_parent(entry); + depth--; + } while (entry && entry != root && (depth >= 0)); + if (forwards) + print_irq_lock_scenario(root, other, + middle ? middle->class : root->class, other->class); + else + print_irq_lock_scenario(other, root, + middle ? middle->class : other->class, root->class); + lockdep_print_held_locks(curr); printk("\nthe shortest dependencies between 2nd lock and 1st lock:\n"); diff --git a/kernel/module.c b/kernel/module.c index d5938a5c19c4..22879725678d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -57,6 +57,7 @@ #include <linux/kmemleak.h> #include <linux/jump_label.h> #include <linux/pfn.h> +#include <linux/bsearch.h> #define CREATE_TRACE_POINTS #include <trace/events/module.h> @@ -240,23 +241,24 @@ static bool each_symbol_in_section(const struct symsearch *arr, struct module *owner, bool (*fn)(const struct symsearch *syms, struct module *owner, - unsigned int symnum, void *data), + void *data), void *data) { - unsigned int i, j; + unsigned int j; for (j = 0; j < arrsize; j++) { - for (i = 0; i < arr[j].stop - arr[j].start; i++) - if (fn(&arr[j], owner, i, data)) - return true; + if (fn(&arr[j], owner, data)) + return true; } return false; } /* Returns true as soon as fn returns true, otherwise false. */ -bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner, - unsigned int symnum, void *data), void *data) +bool each_symbol_section(bool (*fn)(const struct symsearch *arr, + struct module *owner, + void *data), + void *data) { struct module *mod; static const struct symsearch arr[] = { @@ -309,7 +311,7 @@ bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner, } return false; } -EXPORT_SYMBOL_GPL(each_symbol); +EXPORT_SYMBOL_GPL(each_symbol_section); struct find_symbol_arg { /* Input */ @@ -323,15 +325,12 @@ struct find_symbol_arg { const struct kernel_symbol *sym; }; -static bool find_symbol_in_section(const struct symsearch *syms, - struct module *owner, - unsigned int symnum, void *data) +static bool check_symbol(const struct symsearch *syms, + struct module *owner, + unsigned int symnum, void *data) { struct find_symbol_arg *fsa = data; - if (strcmp(syms->start[symnum].name, fsa->name) != 0) - return false; - if (!fsa->gplok) { if (syms->licence == GPL_ONLY) return false; @@ -365,6 +364,30 @@ static bool find_symbol_in_section(const struct symsearch *syms, return true; } +static int cmp_name(const void *va, const void *vb) +{ + const char *a; + const struct kernel_symbol *b; + a = va; b = vb; + return strcmp(a, b->name); +} + +static bool find_symbol_in_section(const struct symsearch *syms, + struct module *owner, + void *data) +{ + struct find_symbol_arg *fsa = data; + struct kernel_symbol *sym; + + sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, + sizeof(struct kernel_symbol), cmp_name); + + if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data)) + return true; + + return false; +} + /* Find a symbol and return it, along with, (optional) crc and * (optional) module which owns it. Needs preempt disabled or module_mutex. */ const struct kernel_symbol *find_symbol(const char *name, @@ -379,7 +402,7 @@ const struct kernel_symbol *find_symbol(const char *name, fsa.gplok = gplok; fsa.warn = warn; - if (each_symbol(find_symbol_in_section, &fsa)) { + if (each_symbol_section(find_symbol_in_section, &fsa)) { if (owner) *owner = fsa.owner; if (crc) @@ -1607,27 +1630,28 @@ static void set_section_ro_nx(void *base, } } -/* Setting memory back to RW+NX before releasing it */ -void unset_section_ro_nx(struct module *mod, void *module_region) +static void unset_module_core_ro_nx(struct module *mod) { - unsigned long total_pages; - - if (mod->module_core == module_region) { - /* Set core as NX+RW */ - total_pages = MOD_NUMBER_OF_PAGES(mod->module_core, mod->core_size); - set_memory_nx((unsigned long)mod->module_core, total_pages); - set_memory_rw((unsigned long)mod->module_core, total_pages); + set_page_attributes(mod->module_core + mod->core_text_size, + mod->module_core + mod->core_size, + set_memory_x); + set_page_attributes(mod->module_core, + mod->module_core + mod->core_ro_size, + set_memory_rw); +} - } else if (mod->module_init == module_region) { - /* Set init as NX+RW */ - total_pages = MOD_NUMBER_OF_PAGES(mod->module_init, mod->init_size); - set_memory_nx((unsigned long)mod->module_init, total_pages); - set_memory_rw((unsigned long)mod->module_init, total_pages); - } +static void unset_module_init_ro_nx(struct module *mod) +{ + set_page_attributes(mod->module_init + mod->init_text_size, + mod->module_init + mod->init_size, + set_memory_x); + set_page_attributes(mod->module_init, + mod->module_init + mod->init_ro_size, + set_memory_rw); } /* Iterate through all modules and set each module's text as RW */ -void set_all_modules_text_rw() +void set_all_modules_text_rw(void) { struct module *mod; @@ -1648,7 +1672,7 @@ void set_all_modules_text_rw() } /* Iterate through all modules and set each module's text as RO */ -void set_all_modules_text_ro() +void set_all_modules_text_ro(void) { struct module *mod; @@ -1669,7 +1693,8 @@ void set_all_modules_text_ro() } #else static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { } -static inline void unset_section_ro_nx(struct module *mod, void *module_region) { } +static void unset_module_core_ro_nx(struct module *mod) { } +static void unset_module_init_ro_nx(struct module *mod) { } #endif /* Free a module, remove from lists, etc. */ @@ -1696,7 +1721,7 @@ static void free_module(struct module *mod) destroy_params(mod->kp, mod->num_kp); /* This may be NULL, but that's OK */ - unset_section_ro_nx(mod, mod->module_init); + unset_module_init_ro_nx(mod); module_free(mod, mod->module_init); kfree(mod->args); percpu_modfree(mod); @@ -1705,7 +1730,7 @@ static void free_module(struct module *mod) lockdep_free_key_range(mod->module_core, mod->core_size); /* Finally, free the core (containing the module structure) */ - unset_section_ro_nx(mod, mod->module_core); + unset_module_core_ro_nx(mod); module_free(mod, mod->module_core); #ifdef CONFIG_MPU @@ -2030,11 +2055,8 @@ static const struct kernel_symbol *lookup_symbol(const char *name, const struct kernel_symbol *start, const struct kernel_symbol *stop) { - const struct kernel_symbol *ks = start; - for (; ks < stop; ks++) - if (strcmp(ks->name, name) == 0) - return ks; - return NULL; + return bsearch(name, start, stop - start, + sizeof(struct kernel_symbol), cmp_name); } static int is_exported(const char *name, unsigned long value, @@ -2931,10 +2953,11 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, mod->symtab = mod->core_symtab; mod->strtab = mod->core_strtab; #endif - unset_section_ro_nx(mod, mod->module_init); + unset_module_init_ro_nx(mod); module_free(mod, mod->module_init); mod->module_init = NULL; mod->init_size = 0; + mod->init_ro_size = 0; mod->init_text_size = 0; mutex_unlock(&module_mutex); diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c index ec815a960b5d..73da83aff418 100644 --- a/kernel/mutex-debug.c +++ b/kernel/mutex-debug.c @@ -75,7 +75,7 @@ void debug_mutex_unlock(struct mutex *lock) return; DEBUG_LOCKS_WARN_ON(lock->magic != lock); - DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); + DEBUG_LOCKS_WARN_ON(lock->owner != current); DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next); mutex_clear_owner(lock); } diff --git a/kernel/mutex-debug.h b/kernel/mutex-debug.h index 57d527a16f9d..0799fd3e4cfa 100644 --- a/kernel/mutex-debug.h +++ b/kernel/mutex-debug.h @@ -29,7 +29,7 @@ extern void debug_mutex_init(struct mutex *lock, const char *name, static inline void mutex_set_owner(struct mutex *lock) { - lock->owner = current_thread_info(); + lock->owner = current; } static inline void mutex_clear_owner(struct mutex *lock) diff --git a/kernel/mutex.c b/kernel/mutex.c index c4195fa98900..2c938e2337cd 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -160,14 +160,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, */ for (;;) { - struct thread_info *owner; - - /* - * If we own the BKL, then don't spin. The owner of - * the mutex might be waiting on us to release the BKL. - */ - if (unlikely(current->lock_depth >= 0)) - break; + struct task_struct *owner; /* * If there's an owner, wait for it to either diff --git a/kernel/mutex.h b/kernel/mutex.h index 67578ca48f94..4115fbf83b12 100644 --- a/kernel/mutex.h +++ b/kernel/mutex.h @@ -19,7 +19,7 @@ #ifdef CONFIG_SMP static inline void mutex_set_owner(struct mutex *lock) { - lock->owner = current_thread_info(); + lock->owner = current; } static inline void mutex_clear_owner(struct mutex *lock) diff --git a/kernel/params.c b/kernel/params.c index 7ab388a48a2e..ed72e1330862 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -297,21 +297,15 @@ EXPORT_SYMBOL(param_ops_charp); int param_set_bool(const char *val, const struct kernel_param *kp) { bool v; + int ret; /* No equals means "set"... */ if (!val) val = "1"; /* One of =[yYnN01] */ - switch (val[0]) { - case 'y': case 'Y': case '1': - v = true; - break; - case 'n': case 'N': case '0': - v = false; - break; - default: - return -EINVAL; - } + ret = strtobool(val, &v); + if (ret) + return ret; if (kp->flags & KPARAM_ISBOOL) *(bool *)kp->arg = v; @@ -821,15 +815,18 @@ ssize_t __modver_version_show(struct module_attribute *mattr, return sprintf(buf, "%s\n", vattr->version); } -extern struct module_version_attribute __start___modver[], __stop___modver[]; +extern const struct module_version_attribute *__start___modver[]; +extern const struct module_version_attribute *__stop___modver[]; static void __init version_sysfs_builtin(void) { - const struct module_version_attribute *vattr; + const struct module_version_attribute **p; struct module_kobject *mk; int err; - for (vattr = __start___modver; vattr < __stop___modver; vattr++) { + for (p = __start___modver; p < __stop___modver; p++) { + const struct module_version_attribute *vattr = *p; + mk = locate_module_kobject(vattr->module_name); if (mk) { err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr); diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 6de9a8fc3417..87f4d24b55b0 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -125,12 +125,6 @@ config PM_DEBUG code. This is helpful when debugging and reporting PM bugs, like suspend support. -config PM_VERBOSE - bool "Verbose Power Management debugging" - depends on PM_DEBUG - ---help--- - This option enables verbose messages from the Power Management code. - config PM_ADVANCED_DEBUG bool "Extra PM attributes in sysfs for low-level debugging/testing" depends on PM_DEBUG @@ -229,3 +223,7 @@ config PM_OPP representing individual voltage domains and provides SOC implementations a ready to use framework to manage OPPs. For more information, read <file:Documentation/power/opp.txt> + +config PM_RUNTIME_CLK + def_bool y + depends on PM_RUNTIME && HAVE_CLK diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 50aae660174d..f9bec56d8825 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -272,12 +272,7 @@ static int create_image(int platform_mode) local_irq_disable(); - error = sysdev_suspend(PMSG_FREEZE); - if (!error) { - error = syscore_suspend(); - if (error) - sysdev_resume(); - } + error = syscore_suspend(); if (error) { printk(KERN_ERR "PM: Some system devices failed to power down, " "aborting hibernation\n"); @@ -302,7 +297,6 @@ static int create_image(int platform_mode) Power_up: syscore_resume(); - sysdev_resume(); /* NOTE: dpm_resume_noirq() is just a resume() for devices * that suspended with irqs off ... no overall powerup. */ @@ -333,20 +327,25 @@ static int create_image(int platform_mode) int hibernation_snapshot(int platform_mode) { + pm_message_t msg = PMSG_RECOVER; int error; error = platform_begin(platform_mode); if (error) goto Close; + error = dpm_prepare(PMSG_FREEZE); + if (error) + goto Complete_devices; + /* Preallocate image memory before shutting down devices. */ error = hibernate_preallocate_memory(); if (error) - goto Close; + goto Complete_devices; suspend_console(); pm_restrict_gfp_mask(); - error = dpm_suspend_start(PMSG_FREEZE); + error = dpm_suspend(PMSG_FREEZE); if (error) goto Recover_platform; @@ -364,13 +363,17 @@ int hibernation_snapshot(int platform_mode) if (error || !in_suspend) swsusp_free(); - dpm_resume_end(in_suspend ? - (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); + msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE; + dpm_resume(msg); if (error || !in_suspend) pm_restore_gfp_mask(); resume_console(); + + Complete_devices: + dpm_complete(msg); + Close: platform_end(platform_mode); return error; @@ -409,12 +412,7 @@ static int resume_target_kernel(bool platform_mode) local_irq_disable(); - error = sysdev_suspend(PMSG_QUIESCE); - if (!error) { - error = syscore_suspend(); - if (error) - sysdev_resume(); - } + error = syscore_suspend(); if (error) goto Enable_irqs; @@ -442,7 +440,6 @@ static int resume_target_kernel(bool platform_mode) touch_softlockup_watchdog(); syscore_resume(); - sysdev_resume(); Enable_irqs: local_irq_enable(); @@ -528,7 +525,6 @@ int hibernation_platform_enter(void) goto Platform_finish; local_irq_disable(); - sysdev_suspend(PMSG_HIBERNATE); syscore_suspend(); if (pm_wakeup_pending()) { error = -EAGAIN; @@ -541,7 +537,6 @@ int hibernation_platform_enter(void) Power_up: syscore_resume(); - sysdev_resume(); local_irq_enable(); enable_nonboot_cpus(); @@ -982,10 +977,33 @@ static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *att power_attr(image_size); +static ssize_t reserved_size_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%lu\n", reserved_size); +} + +static ssize_t reserved_size_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + unsigned long size; + + if (sscanf(buf, "%lu", &size) == 1) { + reserved_size = size; + return n; + } + + return -EINVAL; +} + +power_attr(reserved_size); + static struct attribute * g[] = { &disk_attr.attr, &resume_attr.attr, &image_size_attr.attr, + &reserved_size_attr.attr, NULL, }; diff --git a/kernel/power/main.c b/kernel/power/main.c index de9aef8742f4..2981af4ce7cb 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -337,6 +337,7 @@ static int __init pm_init(void) if (error) return error; hibernate_image_size_init(); + hibernate_reserved_size_init(); power_kobj = kobject_create_and_add("power", NULL); if (!power_kobj) return -ENOMEM; diff --git a/kernel/power/power.h b/kernel/power/power.h index 03634be55f62..9a00a0a26280 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -15,6 +15,7 @@ struct swsusp_info { #ifdef CONFIG_HIBERNATION /* kernel/power/snapshot.c */ +extern void __init hibernate_reserved_size_init(void); extern void __init hibernate_image_size_init(void); #ifdef CONFIG_ARCH_HIBERNATION_HEADER @@ -55,6 +56,7 @@ extern int hibernation_platform_enter(void); #else /* !CONFIG_HIBERNATION */ +static inline void hibernate_reserved_size_init(void) {} static inline void hibernate_image_size_init(void) {} #endif /* !CONFIG_HIBERNATION */ @@ -72,6 +74,8 @@ static struct kobj_attribute _name##_attr = { \ /* Preferred image size in bytes (default 500 MB) */ extern unsigned long image_size; +/* Size of memory reserved for drivers (default SPARE_PAGES x PAGE_SIZE) */ +extern unsigned long reserved_size; extern int in_suspend; extern dev_t swsusp_resume_device; extern sector_t swsusp_resume_block; diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index ca0aacc24874..ace55889f702 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -41,16 +41,28 @@ static void swsusp_set_page_forbidden(struct page *); static void swsusp_unset_page_forbidden(struct page *); /* + * Number of bytes to reserve for memory allocations made by device drivers + * from their ->freeze() and ->freeze_noirq() callbacks so that they don't + * cause image creation to fail (tunable via /sys/power/reserved_size). + */ +unsigned long reserved_size; + +void __init hibernate_reserved_size_init(void) +{ + reserved_size = SPARE_PAGES * PAGE_SIZE; +} + +/* * Preferred image size in bytes (tunable via /sys/power/image_size). - * When it is set to N, the image creating code will do its best to - * ensure the image size will not exceed N bytes, but if that is - * impossible, it will try to create the smallest image possible. + * When it is set to N, swsusp will do its best to ensure the image + * size will not exceed N bytes, but if that is impossible, it will + * try to create the smallest image possible. */ unsigned long image_size; void __init hibernate_image_size_init(void) { - image_size = (totalram_pages / 3) * PAGE_SIZE; + image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE; } /* List of PBEs needed for restoring the pages that were allocated before @@ -1263,11 +1275,13 @@ static unsigned long minimum_image_size(unsigned long saveable) * frame in use. We also need a number of page frames to be free during * hibernation for allocations made while saving the image and for device * drivers, in case they need to allocate memory from their hibernation - * callbacks (these two numbers are given by PAGES_FOR_IO and SPARE_PAGES, - * respectively, both of which are rough estimates). To make this happen, we - * compute the total number of available page frames and allocate at least + * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough + * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through + * /sys/power/reserved_size, respectively). To make this happen, we compute the + * total number of available page frames and allocate at least * - * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 + 2 * SPARE_PAGES + * ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 + * + 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE) * * of them, which corresponds to the maximum size of a hibernation image. * @@ -1322,7 +1336,8 @@ int hibernate_preallocate_memory(void) count -= totalreserve_pages; /* Compute the maximum number of saveable pages to leave in memory. */ - max_size = (count - (size + PAGES_FOR_IO)) / 2 - 2 * SPARE_PAGES; + max_size = (count - (size + PAGES_FOR_IO)) / 2 + - 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE); /* Compute the desired number of image pages specified by image_size. */ size = DIV_ROUND_UP(image_size, PAGE_SIZE); if (size > max_size) diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 8935369d503a..1c41ba215419 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -163,19 +163,13 @@ static int suspend_enter(suspend_state_t state) arch_suspend_disable_irqs(); BUG_ON(!irqs_disabled()); - error = sysdev_suspend(PMSG_SUSPEND); - if (!error) { - error = syscore_suspend(); - if (error) - sysdev_resume(); - } + error = syscore_suspend(); if (!error) { if (!(suspend_test(TEST_CORE) || pm_wakeup_pending())) { error = suspend_ops->enter(state); events_check_enabled = false; } syscore_resume(); - sysdev_resume(); } arch_suspend_enable_irqs(); @@ -216,7 +210,6 @@ int suspend_devices_and_enter(suspend_state_t state) goto Close; } suspend_console(); - pm_restrict_gfp_mask(); suspend_test_start(); error = dpm_suspend_start(PMSG_SUSPEND); if (error) { @@ -227,13 +220,12 @@ int suspend_devices_and_enter(suspend_state_t state) if (suspend_test(TEST_DEVICES)) goto Recover_platform; - suspend_enter(state); + error = suspend_enter(state); Resume_devices: suspend_test_start(); dpm_resume_end(PMSG_RESUME); suspend_test_finish("resume devices"); - pm_restore_gfp_mask(); resume_console(); Close: if (suspend_ops->end) @@ -294,7 +286,9 @@ int enter_state(suspend_state_t state) goto Finish; pr_debug("PM: Entering %s sleep\n", pm_states[state]); + pm_restrict_gfp_mask(); error = suspend_devices_and_enter(state); + pm_restore_gfp_mask(); Finish: pr_debug("PM: Finishing wakeup.\n"); diff --git a/kernel/power/user.c b/kernel/power/user.c index c36c3b9e8a84..7d02d33be699 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -135,8 +135,10 @@ static int snapshot_release(struct inode *inode, struct file *filp) free_basic_memory_bitmaps(); data = filp->private_data; free_all_swap_pages(data->swap); - if (data->frozen) + if (data->frozen) { + pm_restore_gfp_mask(); thaw_processes(); + } pm_notifier_call_chain(data->mode == O_RDONLY ? PM_POST_HIBERNATION : PM_POST_RESTORE); atomic_inc(&snapshot_device_available); @@ -379,6 +381,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, * PM_HIBERNATION_PREPARE */ error = suspend_devices_and_enter(PM_SUSPEND_MEM); + data->ready = 0; break; case SNAPSHOT_PLATFORM_SUPPORT: diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 0fc1eed28d27..dc7ab65f3b36 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -22,6 +22,7 @@ #include <linux/syscalls.h> #include <linux/uaccess.h> #include <linux/regset.h> +#include <linux/hw_breakpoint.h> /* @@ -879,3 +880,19 @@ asmlinkage long compat_sys_ptrace(compat_long_t request, compat_long_t pid, return ret; } #endif /* CONFIG_COMPAT */ + +#ifdef CONFIG_HAVE_HW_BREAKPOINT +int ptrace_get_breakpoints(struct task_struct *tsk) +{ + if (atomic_inc_not_zero(&tsk->ptrace_bp_refcnt)) + return 0; + + return -1; +} + +void ptrace_put_breakpoints(struct task_struct *tsk) +{ + if (atomic_dec_and_test(&tsk->ptrace_bp_refcnt)) + flush_ptrace_hw_breakpoint(tsk); +} +#endif /* CONFIG_HAVE_HW_BREAKPOINT */ diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c index f3240e987928..7784bd216b6a 100644 --- a/kernel/rcupdate.c +++ b/kernel/rcupdate.c @@ -142,10 +142,17 @@ static int rcuhead_fixup_init(void *addr, enum debug_obj_state state) * Ensure that queued callbacks are all executed. * If we detect that we are nested in a RCU read-side critical * section, we should simply fail, otherwise we would deadlock. + * In !PREEMPT configurations, there is no way to tell if we are + * in a RCU read-side critical section or not, so we never + * attempt any fixup and just print a warning. */ +#ifndef CONFIG_PREEMPT + WARN_ON_ONCE(1); + return 0; +#endif if (rcu_preempt_depth() != 0 || preempt_count() != 0 || irqs_disabled()) { - WARN_ON(1); + WARN_ON_ONCE(1); return 0; } rcu_barrier(); @@ -184,10 +191,17 @@ static int rcuhead_fixup_activate(void *addr, enum debug_obj_state state) * Ensure that queued callbacks are all executed. * If we detect that we are nested in a RCU read-side critical * section, we should simply fail, otherwise we would deadlock. + * In !PREEMPT configurations, there is no way to tell if we are + * in a RCU read-side critical section or not, so we never + * attempt any fixup and just print a warning. */ +#ifndef CONFIG_PREEMPT + WARN_ON_ONCE(1); + return 0; +#endif if (rcu_preempt_depth() != 0 || preempt_count() != 0 || irqs_disabled()) { - WARN_ON(1); + WARN_ON_ONCE(1); return 0; } rcu_barrier(); @@ -214,15 +228,17 @@ static int rcuhead_fixup_free(void *addr, enum debug_obj_state state) * Ensure that queued callbacks are all executed. * If we detect that we are nested in a RCU read-side critical * section, we should simply fail, otherwise we would deadlock. - * Note that the machinery to reliably determine whether - * or not we are in an RCU read-side critical section - * exists only in the preemptible RCU implementations - * (TINY_PREEMPT_RCU and TREE_PREEMPT_RCU), which is why - * DEBUG_OBJECTS_RCU_HEAD is disallowed if !PREEMPT. + * In !PREEMPT configurations, there is no way to tell if we are + * in a RCU read-side critical section or not, so we never + * attempt any fixup and just print a warning. */ +#ifndef CONFIG_PREEMPT + WARN_ON_ONCE(1); + return 0; +#endif if (rcu_preempt_depth() != 0 || preempt_count() != 0 || irqs_disabled()) { - WARN_ON(1); + WARN_ON_ONCE(1); return 0; } rcu_barrier(); diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c index 0c343b9a46d5..421abfd3641d 100644 --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -40,10 +40,10 @@ static struct task_struct *rcu_kthread_task; static DECLARE_WAIT_QUEUE_HEAD(rcu_kthread_wq); static unsigned long have_rcu_kthread_work; -static void invoke_rcu_kthread(void); /* Forward declarations for rcutiny_plugin.h. */ struct rcu_ctrlblk; +static void invoke_rcu_kthread(void); static void rcu_process_callbacks(struct rcu_ctrlblk *rcp); static int rcu_kthread(void *arg); static void __call_rcu(struct rcu_head *head, @@ -79,36 +79,45 @@ void rcu_exit_nohz(void) #endif /* #ifdef CONFIG_NO_HZ */ /* - * Helper function for rcu_qsctr_inc() and rcu_bh_qsctr_inc(). - * Also disable irqs to avoid confusion due to interrupt handlers + * Helper function for rcu_sched_qs() and rcu_bh_qs(). + * Also irqs are disabled to avoid confusion due to interrupt handlers * invoking call_rcu(). */ static int rcu_qsctr_help(struct rcu_ctrlblk *rcp) { - unsigned long flags; - - local_irq_save(flags); if (rcp->rcucblist != NULL && rcp->donetail != rcp->curtail) { rcp->donetail = rcp->curtail; - local_irq_restore(flags); return 1; } - local_irq_restore(flags); return 0; } /* + * Wake up rcu_kthread() to process callbacks now eligible for invocation + * or to boost readers. + */ +static void invoke_rcu_kthread(void) +{ + have_rcu_kthread_work = 1; + wake_up(&rcu_kthread_wq); +} + +/* * Record an rcu quiescent state. And an rcu_bh quiescent state while we * are at it, given that any rcu quiescent state is also an rcu_bh * quiescent state. Use "+" instead of "||" to defeat short circuiting. */ void rcu_sched_qs(int cpu) { + unsigned long flags; + + local_irq_save(flags); if (rcu_qsctr_help(&rcu_sched_ctrlblk) + rcu_qsctr_help(&rcu_bh_ctrlblk)) invoke_rcu_kthread(); + local_irq_restore(flags); } /* @@ -116,8 +125,12 @@ void rcu_sched_qs(int cpu) */ void rcu_bh_qs(int cpu) { + unsigned long flags; + + local_irq_save(flags); if (rcu_qsctr_help(&rcu_bh_ctrlblk)) invoke_rcu_kthread(); + local_irq_restore(flags); } /* @@ -167,7 +180,7 @@ static void rcu_process_callbacks(struct rcu_ctrlblk *rcp) prefetch(next); debug_rcu_head_unqueue(list); local_bh_disable(); - list->func(list); + __rcu_reclaim(list); local_bh_enable(); list = next; RCU_TRACE(cb_count++); @@ -208,20 +221,6 @@ static int rcu_kthread(void *arg) } /* - * Wake up rcu_kthread() to process callbacks now eligible for invocation - * or to boost readers. - */ -static void invoke_rcu_kthread(void) -{ - unsigned long flags; - - local_irq_save(flags); - have_rcu_kthread_work = 1; - wake_up(&rcu_kthread_wq); - local_irq_restore(flags); -} - -/* * Wait for a grace period to elapse. But it is illegal to invoke * synchronize_sched() from within an RCU read-side critical section. * Therefore, any legal call to synchronize_sched() is a quiescent diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h index 3cb8e362e883..f259c676195f 100644 --- a/kernel/rcutiny_plugin.h +++ b/kernel/rcutiny_plugin.h @@ -100,23 +100,28 @@ struct rcu_preempt_ctrlblk { u8 completed; /* Last grace period completed. */ /* If all three are equal, RCU is idle. */ #ifdef CONFIG_RCU_BOOST - s8 boosted_this_gp; /* Has boosting already happened? */ unsigned long boost_time; /* When to start boosting (jiffies) */ #endif /* #ifdef CONFIG_RCU_BOOST */ #ifdef CONFIG_RCU_TRACE unsigned long n_grace_periods; #ifdef CONFIG_RCU_BOOST unsigned long n_tasks_boosted; + /* Total number of tasks boosted. */ unsigned long n_exp_boosts; + /* Number of tasks boosted for expedited GP. */ unsigned long n_normal_boosts; - unsigned long n_normal_balk_blkd_tasks; - unsigned long n_normal_balk_gp_tasks; - unsigned long n_normal_balk_boost_tasks; - unsigned long n_normal_balk_boosted; - unsigned long n_normal_balk_notyet; - unsigned long n_normal_balk_nos; - unsigned long n_exp_balk_blkd_tasks; - unsigned long n_exp_balk_nos; + /* Number of tasks boosted for normal GP. */ + unsigned long n_balk_blkd_tasks; + /* Refused to boost: no blocked tasks. */ + unsigned long n_balk_exp_gp_tasks; + /* Refused to boost: nothing blocking GP. */ + unsigned long n_balk_boost_tasks; + /* Refused to boost: already boosting. */ + unsigned long n_balk_notyet; + /* Refused to boost: not yet time. */ + unsigned long n_balk_nos; + /* Refused to boost: not sure why, though. */ + /* This can happen due to race conditions. */ #endif /* #ifdef CONFIG_RCU_BOOST */ #endif /* #ifdef CONFIG_RCU_TRACE */ }; @@ -201,7 +206,6 @@ static struct list_head *rcu_next_node_entry(struct task_struct *t) #ifdef CONFIG_RCU_BOOST static void rcu_initiate_boost_trace(void); -static void rcu_initiate_exp_boost_trace(void); #endif /* #ifdef CONFIG_RCU_BOOST */ /* @@ -219,41 +223,21 @@ static void show_tiny_preempt_stats(struct seq_file *m) "N."[!rcu_preempt_ctrlblk.gp_tasks], "E."[!rcu_preempt_ctrlblk.exp_tasks]); #ifdef CONFIG_RCU_BOOST - seq_printf(m, " ttb=%c btg=", - "B."[!rcu_preempt_ctrlblk.boost_tasks]); - switch (rcu_preempt_ctrlblk.boosted_this_gp) { - case -1: - seq_puts(m, "exp"); - break; - case 0: - seq_puts(m, "no"); - break; - case 1: - seq_puts(m, "begun"); - break; - case 2: - seq_puts(m, "done"); - break; - default: - seq_printf(m, "?%d?", rcu_preempt_ctrlblk.boosted_this_gp); - } - seq_printf(m, " ntb=%lu neb=%lu nnb=%lu j=%04x bt=%04x\n", + seq_printf(m, "%sttb=%c ntb=%lu neb=%lu nnb=%lu j=%04x bt=%04x\n", + " ", + "B."[!rcu_preempt_ctrlblk.boost_tasks], rcu_preempt_ctrlblk.n_tasks_boosted, rcu_preempt_ctrlblk.n_exp_boosts, rcu_preempt_ctrlblk.n_normal_boosts, (int)(jiffies & 0xffff), (int)(rcu_preempt_ctrlblk.boost_time & 0xffff)); - seq_printf(m, " %s: nt=%lu gt=%lu bt=%lu b=%lu ny=%lu nos=%lu\n", - "normal balk", - rcu_preempt_ctrlblk.n_normal_balk_blkd_tasks, - rcu_preempt_ctrlblk.n_normal_balk_gp_tasks, - rcu_preempt_ctrlblk.n_normal_balk_boost_tasks, - rcu_preempt_ctrlblk.n_normal_balk_boosted, - rcu_preempt_ctrlblk.n_normal_balk_notyet, - rcu_preempt_ctrlblk.n_normal_balk_nos); - seq_printf(m, " exp balk: bt=%lu nos=%lu\n", - rcu_preempt_ctrlblk.n_exp_balk_blkd_tasks, - rcu_preempt_ctrlblk.n_exp_balk_nos); + seq_printf(m, "%s: nt=%lu egt=%lu bt=%lu ny=%lu nos=%lu\n", + " balk", + rcu_preempt_ctrlblk.n_balk_blkd_tasks, + rcu_preempt_ctrlblk.n_balk_exp_gp_tasks, + rcu_preempt_ctrlblk.n_balk_boost_tasks, + rcu_preempt_ctrlblk.n_balk_notyet, + rcu_preempt_ctrlblk.n_balk_nos); #endif /* #ifdef CONFIG_RCU_BOOST */ } @@ -271,25 +255,59 @@ static int rcu_boost(void) { unsigned long flags; struct rt_mutex mtx; - struct list_head *np; struct task_struct *t; + struct list_head *tb; - if (rcu_preempt_ctrlblk.boost_tasks == NULL) + if (rcu_preempt_ctrlblk.boost_tasks == NULL && + rcu_preempt_ctrlblk.exp_tasks == NULL) return 0; /* Nothing to boost. */ + raw_local_irq_save(flags); - rcu_preempt_ctrlblk.boosted_this_gp++; - t = container_of(rcu_preempt_ctrlblk.boost_tasks, struct task_struct, - rcu_node_entry); - np = rcu_next_node_entry(t); + + /* + * Recheck with irqs disabled: all tasks in need of boosting + * might exit their RCU read-side critical sections on their own + * if we are preempted just before disabling irqs. + */ + if (rcu_preempt_ctrlblk.boost_tasks == NULL && + rcu_preempt_ctrlblk.exp_tasks == NULL) { + raw_local_irq_restore(flags); + return 0; + } + + /* + * Preferentially boost tasks blocking expedited grace periods. + * This cannot starve the normal grace periods because a second + * expedited grace period must boost all blocked tasks, including + * those blocking the pre-existing normal grace period. + */ + if (rcu_preempt_ctrlblk.exp_tasks != NULL) { + tb = rcu_preempt_ctrlblk.exp_tasks; + RCU_TRACE(rcu_preempt_ctrlblk.n_exp_boosts++); + } else { + tb = rcu_preempt_ctrlblk.boost_tasks; + RCU_TRACE(rcu_preempt_ctrlblk.n_normal_boosts++); + } + RCU_TRACE(rcu_preempt_ctrlblk.n_tasks_boosted++); + + /* + * We boost task t by manufacturing an rt_mutex that appears to + * be held by task t. We leave a pointer to that rt_mutex where + * task t can find it, and task t will release the mutex when it + * exits its outermost RCU read-side critical section. Then + * simply acquiring this artificial rt_mutex will boost task + * t's priority. (Thanks to tglx for suggesting this approach!) + */ + t = container_of(tb, struct task_struct, rcu_node_entry); rt_mutex_init_proxy_locked(&mtx, t); t->rcu_boost_mutex = &mtx; t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BOOSTED; raw_local_irq_restore(flags); rt_mutex_lock(&mtx); - RCU_TRACE(rcu_preempt_ctrlblk.n_tasks_boosted++); - rcu_preempt_ctrlblk.boosted_this_gp++; - rt_mutex_unlock(&mtx); - return rcu_preempt_ctrlblk.boost_tasks != NULL; + rt_mutex_unlock(&mtx); /* Keep lockdep happy. */ + + return rcu_preempt_ctrlblk.boost_tasks != NULL || + rcu_preempt_ctrlblk.exp_tasks != NULL; } /* @@ -304,42 +322,25 @@ static int rcu_boost(void) */ static int rcu_initiate_boost(void) { - if (!rcu_preempt_blocked_readers_cgp()) { - RCU_TRACE(rcu_preempt_ctrlblk.n_normal_balk_blkd_tasks++); + if (!rcu_preempt_blocked_readers_cgp() && + rcu_preempt_ctrlblk.exp_tasks == NULL) { + RCU_TRACE(rcu_preempt_ctrlblk.n_balk_exp_gp_tasks++); return 0; } - if (rcu_preempt_ctrlblk.gp_tasks != NULL && - rcu_preempt_ctrlblk.boost_tasks == NULL && - rcu_preempt_ctrlblk.boosted_this_gp == 0 && - ULONG_CMP_GE(jiffies, rcu_preempt_ctrlblk.boost_time)) { - rcu_preempt_ctrlblk.boost_tasks = rcu_preempt_ctrlblk.gp_tasks; + if (rcu_preempt_ctrlblk.exp_tasks != NULL || + (rcu_preempt_ctrlblk.gp_tasks != NULL && + rcu_preempt_ctrlblk.boost_tasks == NULL && + ULONG_CMP_GE(jiffies, rcu_preempt_ctrlblk.boost_time))) { + if (rcu_preempt_ctrlblk.exp_tasks == NULL) + rcu_preempt_ctrlblk.boost_tasks = + rcu_preempt_ctrlblk.gp_tasks; invoke_rcu_kthread(); - RCU_TRACE(rcu_preempt_ctrlblk.n_normal_boosts++); } else RCU_TRACE(rcu_initiate_boost_trace()); return 1; } -/* - * Initiate boosting for an expedited grace period. - */ -static void rcu_initiate_expedited_boost(void) -{ - unsigned long flags; - - raw_local_irq_save(flags); - if (!list_empty(&rcu_preempt_ctrlblk.blkd_tasks)) { - rcu_preempt_ctrlblk.boost_tasks = - rcu_preempt_ctrlblk.blkd_tasks.next; - rcu_preempt_ctrlblk.boosted_this_gp = -1; - invoke_rcu_kthread(); - RCU_TRACE(rcu_preempt_ctrlblk.n_exp_boosts++); - } else - RCU_TRACE(rcu_initiate_exp_boost_trace()); - raw_local_irq_restore(flags); -} - -#define RCU_BOOST_DELAY_JIFFIES DIV_ROUND_UP(CONFIG_RCU_BOOST_DELAY * HZ, 1000); +#define RCU_BOOST_DELAY_JIFFIES DIV_ROUND_UP(CONFIG_RCU_BOOST_DELAY * HZ, 1000) /* * Do priority-boost accounting for the start of a new grace period. @@ -347,8 +348,6 @@ static void rcu_initiate_expedited_boost(void) static void rcu_preempt_boost_start_gp(void) { rcu_preempt_ctrlblk.boost_time = jiffies + RCU_BOOST_DELAY_JIFFIES; - if (rcu_preempt_ctrlblk.boosted_this_gp > 0) - rcu_preempt_ctrlblk.boosted_this_gp = 0; } #else /* #ifdef CONFIG_RCU_BOOST */ @@ -372,13 +371,6 @@ static int rcu_initiate_boost(void) } /* - * If there is no RCU priority boosting, we don't initiate expedited boosting. - */ -static void rcu_initiate_expedited_boost(void) -{ -} - -/* * If there is no RCU priority boosting, nothing to do at grace-period start. */ static void rcu_preempt_boost_start_gp(void) @@ -418,7 +410,7 @@ static void rcu_preempt_cpu_qs(void) if (!rcu_preempt_gp_in_progress()) return; /* - * Check up on boosting. If there are no readers blocking the + * Check up on boosting. If there are readers blocking the * current grace period, leave. */ if (rcu_initiate_boost()) @@ -578,7 +570,7 @@ static void rcu_read_unlock_special(struct task_struct *t) empty = !rcu_preempt_blocked_readers_cgp(); empty_exp = rcu_preempt_ctrlblk.exp_tasks == NULL; np = rcu_next_node_entry(t); - list_del(&t->rcu_node_entry); + list_del_init(&t->rcu_node_entry); if (&t->rcu_node_entry == rcu_preempt_ctrlblk.gp_tasks) rcu_preempt_ctrlblk.gp_tasks = np; if (&t->rcu_node_entry == rcu_preempt_ctrlblk.exp_tasks) @@ -587,7 +579,6 @@ static void rcu_read_unlock_special(struct task_struct *t) if (&t->rcu_node_entry == rcu_preempt_ctrlblk.boost_tasks) rcu_preempt_ctrlblk.boost_tasks = np; #endif /* #ifdef CONFIG_RCU_BOOST */ - INIT_LIST_HEAD(&t->rcu_node_entry); /* * If this was the last task on the current list, and if @@ -812,13 +803,16 @@ void synchronize_rcu_expedited(void) rpcp->exp_tasks = rpcp->blkd_tasks.next; if (rpcp->exp_tasks == &rpcp->blkd_tasks) rpcp->exp_tasks = NULL; - local_irq_restore(flags); /* Wait for tail of ->blkd_tasks list to drain. */ - if (rcu_preempted_readers_exp()) - rcu_initiate_expedited_boost(); + if (!rcu_preempted_readers_exp()) + local_irq_restore(flags); + else { + rcu_initiate_boost(); + local_irq_restore(flags); wait_event(sync_rcu_preempt_exp_wq, !rcu_preempted_readers_exp()); + } /* Clean up and exit. */ barrier(); /* ensure expedited GP seen before counter increment. */ @@ -931,24 +925,17 @@ void __init rcu_scheduler_starting(void) static void rcu_initiate_boost_trace(void) { - if (rcu_preempt_ctrlblk.gp_tasks == NULL) - rcu_preempt_ctrlblk.n_normal_balk_gp_tasks++; + if (list_empty(&rcu_preempt_ctrlblk.blkd_tasks)) + rcu_preempt_ctrlblk.n_balk_blkd_tasks++; + else if (rcu_preempt_ctrlblk.gp_tasks == NULL && + rcu_preempt_ctrlblk.exp_tasks == NULL) + rcu_preempt_ctrlblk.n_balk_exp_gp_tasks++; else if (rcu_preempt_ctrlblk.boost_tasks != NULL) - rcu_preempt_ctrlblk.n_normal_balk_boost_tasks++; - else if (rcu_preempt_ctrlblk.boosted_this_gp != 0) - rcu_preempt_ctrlblk.n_normal_balk_boosted++; + rcu_preempt_ctrlblk.n_balk_boost_tasks++; else if (!ULONG_CMP_GE(jiffies, rcu_preempt_ctrlblk.boost_time)) - rcu_preempt_ctrlblk.n_normal_balk_notyet++; - else - rcu_preempt_ctrlblk.n_normal_balk_nos++; -} - -static void rcu_initiate_exp_boost_trace(void) -{ - if (list_empty(&rcu_preempt_ctrlblk.blkd_tasks)) - rcu_preempt_ctrlblk.n_exp_balk_blkd_tasks++; + rcu_preempt_ctrlblk.n_balk_notyet++; else - rcu_preempt_ctrlblk.n_exp_balk_nos++; + rcu_preempt_ctrlblk.n_balk_nos++; } #endif /* #ifdef CONFIG_RCU_BOOST */ diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c index c224da41890c..2e138db03382 100644 --- a/kernel/rcutorture.c +++ b/kernel/rcutorture.c @@ -131,7 +131,7 @@ struct rcu_torture { static LIST_HEAD(rcu_torture_freelist); static struct rcu_torture __rcu *rcu_torture_current; -static long rcu_torture_current_version; +static unsigned long rcu_torture_current_version; static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; static DEFINE_SPINLOCK(rcu_torture_lock); static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = @@ -146,8 +146,6 @@ static atomic_t n_rcu_torture_mberror; static atomic_t n_rcu_torture_error; static long n_rcu_torture_boost_ktrerror; static long n_rcu_torture_boost_rterror; -static long n_rcu_torture_boost_allocerror; -static long n_rcu_torture_boost_afferror; static long n_rcu_torture_boost_failure; static long n_rcu_torture_boosts; static long n_rcu_torture_timers; @@ -163,11 +161,11 @@ static int stutter_pause_test; #endif int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT; -#ifdef CONFIG_RCU_BOOST +#if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) #define rcu_can_boost() 1 -#else /* #ifdef CONFIG_RCU_BOOST */ +#else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ #define rcu_can_boost() 0 -#endif /* #else #ifdef CONFIG_RCU_BOOST */ +#endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ static unsigned long boost_starttime; /* jiffies of next boost test start. */ DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ @@ -751,6 +749,7 @@ static int rcu_torture_boost(void *arg) n_rcu_torture_boost_rterror++; } + init_rcu_head_on_stack(&rbi.rcu); /* Each pass through the following loop does one boost-test cycle. */ do { /* Wait for the next test interval. */ @@ -810,6 +809,7 @@ checkwait: rcu_stutter_wait("rcu_torture_boost"); /* Clean up and exit. */ VERBOSE_PRINTK_STRING("rcu_torture_boost task stopping"); + destroy_rcu_head_on_stack(&rbi.rcu); rcutorture_shutdown_absorb("rcu_torture_boost"); while (!kthread_should_stop() || rbi.inflight) schedule_timeout_uninterruptible(1); @@ -886,7 +886,7 @@ rcu_torture_writer(void *arg) old_rp->rtort_pipe_count++; cur_ops->deferred_free(old_rp); } - rcu_torture_current_version++; + rcutorture_record_progress(++rcu_torture_current_version); oldbatch = cur_ops->completed(); rcu_stutter_wait("rcu_torture_writer"); } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); @@ -1066,8 +1066,8 @@ rcu_torture_printk(char *page) } cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); cnt += sprintf(&page[cnt], - "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d " - "rtmbe: %d rtbke: %ld rtbre: %ld rtbae: %ld rtbafe: %ld " + "rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d " + "rtmbe: %d rtbke: %ld rtbre: %ld " "rtbf: %ld rtb: %ld nt: %ld", rcu_torture_current, rcu_torture_current_version, @@ -1078,16 +1078,12 @@ rcu_torture_printk(char *page) atomic_read(&n_rcu_torture_mberror), n_rcu_torture_boost_ktrerror, n_rcu_torture_boost_rterror, - n_rcu_torture_boost_allocerror, - n_rcu_torture_boost_afferror, n_rcu_torture_boost_failure, n_rcu_torture_boosts, n_rcu_torture_timers); if (atomic_read(&n_rcu_torture_mberror) != 0 || n_rcu_torture_boost_ktrerror != 0 || n_rcu_torture_boost_rterror != 0 || - n_rcu_torture_boost_allocerror != 0 || - n_rcu_torture_boost_afferror != 0 || n_rcu_torture_boost_failure != 0) cnt += sprintf(&page[cnt], " !!!"); cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); @@ -1331,6 +1327,7 @@ rcu_torture_cleanup(void) int i; mutex_lock(&fullstop_mutex); + rcutorture_record_test_transition(); if (fullstop == FULLSTOP_SHUTDOWN) { printk(KERN_WARNING /* but going down anyway, so... */ "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); @@ -1486,8 +1483,6 @@ rcu_torture_init(void) atomic_set(&n_rcu_torture_error, 0); n_rcu_torture_boost_ktrerror = 0; n_rcu_torture_boost_rterror = 0; - n_rcu_torture_boost_allocerror = 0; - n_rcu_torture_boost_afferror = 0; n_rcu_torture_boost_failure = 0; n_rcu_torture_boosts = 0; for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) @@ -1624,6 +1619,7 @@ rcu_torture_init(void) } } register_reboot_notifier(&rcutorture_shutdown_nb); + rcutorture_record_test_transition(); mutex_unlock(&fullstop_mutex); return 0; diff --git a/kernel/rcutree.c b/kernel/rcutree.c index dd4aea806f8e..e486f7c3ffb8 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -47,6 +47,8 @@ #include <linux/mutex.h> #include <linux/time.h> #include <linux/kernel_stat.h> +#include <linux/wait.h> +#include <linux/kthread.h> #include "rcutree.h" @@ -79,10 +81,41 @@ DEFINE_PER_CPU(struct rcu_data, rcu_sched_data); struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state); DEFINE_PER_CPU(struct rcu_data, rcu_bh_data); +static struct rcu_state *rcu_state; + int rcu_scheduler_active __read_mostly; EXPORT_SYMBOL_GPL(rcu_scheduler_active); /* + * Control variables for per-CPU and per-rcu_node kthreads. These + * handle all flavors of RCU. + */ +static DEFINE_PER_CPU(struct task_struct *, rcu_cpu_kthread_task); +DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_status); +DEFINE_PER_CPU(int, rcu_cpu_kthread_cpu); +DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_loops); +static DEFINE_PER_CPU(wait_queue_head_t, rcu_cpu_wq); +DEFINE_PER_CPU(char, rcu_cpu_has_work); +static char rcu_kthreads_spawnable; + +static void rcu_node_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu); +static void invoke_rcu_cpu_kthread(void); + +#define RCU_KTHREAD_PRIO 1 /* RT priority for per-CPU kthreads. */ + +/* + * Track the rcutorture test sequence number and the update version + * number within a given test. The rcutorture_testseq is incremented + * on every rcutorture module load and unload, so has an odd value + * when a test is running. The rcutorture_vernum is set to zero + * when rcutorture starts and is incremented on each rcutorture update. + * These variables enable correlating rcutorture output with the + * RCU tracing information. + */ +unsigned long rcutorture_testseq; +unsigned long rcutorture_vernum; + +/* * Return true if an RCU grace period is in progress. The ACCESS_ONCE()s * permit this function to be invoked without holding the root rcu_node * structure's ->lock, but of course results can be subject to change. @@ -124,6 +157,7 @@ void rcu_note_context_switch(int cpu) rcu_sched_qs(cpu); rcu_preempt_note_context_switch(cpu); } +EXPORT_SYMBOL_GPL(rcu_note_context_switch); #ifdef CONFIG_NO_HZ DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = { @@ -140,10 +174,8 @@ module_param(blimit, int, 0); module_param(qhimark, int, 0); module_param(qlowmark, int, 0); -#ifdef CONFIG_RCU_CPU_STALL_DETECTOR -int rcu_cpu_stall_suppress __read_mostly = RCU_CPU_STALL_SUPPRESS_INIT; +int rcu_cpu_stall_suppress __read_mostly; module_param(rcu_cpu_stall_suppress, int, 0644); -#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ static void force_quiescent_state(struct rcu_state *rsp, int relaxed); static int rcu_pending(int cpu); @@ -176,6 +208,31 @@ void rcu_bh_force_quiescent_state(void) EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state); /* + * Record the number of times rcutorture tests have been initiated and + * terminated. This information allows the debugfs tracing stats to be + * correlated to the rcutorture messages, even when the rcutorture module + * is being repeatedly loaded and unloaded. In other words, we cannot + * store this state in rcutorture itself. + */ +void rcutorture_record_test_transition(void) +{ + rcutorture_testseq++; + rcutorture_vernum = 0; +} +EXPORT_SYMBOL_GPL(rcutorture_record_test_transition); + +/* + * Record the number of writer passes through the current rcutorture test. + * This is also used to correlate debugfs tracing stats with the rcutorture + * messages. + */ +void rcutorture_record_progress(unsigned long vernum) +{ + rcutorture_vernum++; +} +EXPORT_SYMBOL_GPL(rcutorture_record_progress); + +/* * Force a quiescent state for RCU-sched. */ void rcu_sched_force_quiescent_state(void) @@ -234,8 +291,8 @@ static int rcu_implicit_offline_qs(struct rcu_data *rdp) return 1; } - /* If preemptable RCU, no point in sending reschedule IPI. */ - if (rdp->preemptable) + /* If preemptible RCU, no point in sending reschedule IPI. */ + if (rdp->preemptible) return 0; /* The CPU is online, so send it a reschedule IPI. */ @@ -450,8 +507,6 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp) #endif /* #else #ifdef CONFIG_NO_HZ */ -#ifdef CONFIG_RCU_CPU_STALL_DETECTOR - int rcu_cpu_stall_suppress __read_mostly; static void record_gp_stall_check_time(struct rcu_state *rsp) @@ -537,21 +592,24 @@ static void print_cpu_stall(struct rcu_state *rsp) static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) { - long delta; + unsigned long j; + unsigned long js; struct rcu_node *rnp; if (rcu_cpu_stall_suppress) return; - delta = jiffies - ACCESS_ONCE(rsp->jiffies_stall); + j = ACCESS_ONCE(jiffies); + js = ACCESS_ONCE(rsp->jiffies_stall); rnp = rdp->mynode; - if ((ACCESS_ONCE(rnp->qsmask) & rdp->grpmask) && delta >= 0) { + if ((ACCESS_ONCE(rnp->qsmask) & rdp->grpmask) && ULONG_CMP_GE(j, js)) { /* We haven't checked in, so go dump stack. */ print_cpu_stall(rsp); - } else if (rcu_gp_in_progress(rsp) && delta >= RCU_STALL_RAT_DELAY) { + } else if (rcu_gp_in_progress(rsp) && + ULONG_CMP_GE(j, js + RCU_STALL_RAT_DELAY)) { - /* They had two time units to dump stack, so complain. */ + /* They had a few time units to dump stack, so complain. */ print_other_cpu_stall(rsp); } } @@ -587,26 +645,6 @@ static void __init check_cpu_stall_init(void) atomic_notifier_chain_register(&panic_notifier_list, &rcu_panic_block); } -#else /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ - -static void record_gp_stall_check_time(struct rcu_state *rsp) -{ -} - -static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) -{ -} - -void rcu_cpu_stall_reset(void) -{ -} - -static void __init check_cpu_stall_init(void) -{ -} - -#endif /* #else #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ - /* * 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 @@ -809,6 +847,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) rnp->completed = rsp->completed; rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */ rcu_start_gp_per_cpu(rsp, rnp, rdp); + rcu_preempt_boost_start_gp(rnp); raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } @@ -844,6 +883,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) rnp->completed = rsp->completed; if (rnp == rdp->mynode) rcu_start_gp_per_cpu(rsp, rnp, rdp); + rcu_preempt_boost_start_gp(rnp); raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ } @@ -864,7 +904,12 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags) static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags) __releases(rcu_get_root(rsp)->lock) { + unsigned long gp_duration; + WARN_ON_ONCE(!rcu_gp_in_progress(rsp)); + gp_duration = jiffies - rsp->gp_start; + if (gp_duration > rsp->gp_max) + rsp->gp_max = gp_duration; rsp->completed = rsp->gpnum; rsp->signaled = RCU_GP_IDLE; rcu_start_gp(rsp, flags); /* releases root node's rnp->lock. */ @@ -894,7 +939,7 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp, return; } rnp->qsmask &= ~mask; - if (rnp->qsmask != 0 || rcu_preempted_readers(rnp)) { + if (rnp->qsmask != 0 || rcu_preempt_blocked_readers_cgp(rnp)) { /* Other bits still set at this level, so done. */ raw_spin_unlock_irqrestore(&rnp->lock, flags); @@ -1037,6 +1082,8 @@ static void rcu_send_cbs_to_online(struct rcu_state *rsp) /* * Remove the outgoing CPU from the bitmasks in the rcu_node hierarchy * and move all callbacks from the outgoing CPU to the current one. + * There can only be one CPU hotplug operation at a time, so no other + * CPU can be attempting to update rcu_cpu_kthread_task. */ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) { @@ -1045,6 +1092,14 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) int need_report = 0; struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu); struct rcu_node *rnp; + struct task_struct *t; + + /* Stop the CPU's kthread. */ + t = per_cpu(rcu_cpu_kthread_task, cpu); + if (t != NULL) { + per_cpu(rcu_cpu_kthread_task, cpu) = NULL; + kthread_stop(t); + } /* Exclude any attempts to start a new grace period. */ raw_spin_lock_irqsave(&rsp->onofflock, flags); @@ -1082,6 +1137,7 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp) raw_spin_unlock_irqrestore(&rnp->lock, flags); if (need_report & RCU_OFL_TASKS_EXP_GP) rcu_report_exp_rnp(rsp, rnp); + rcu_node_kthread_setaffinity(rnp, -1); } /* @@ -1143,7 +1199,7 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp) next = list->next; prefetch(next); debug_rcu_head_unqueue(list); - list->func(list); + __rcu_reclaim(list); list = next; if (++count >= rdp->blimit) break; @@ -1179,7 +1235,7 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp) /* Re-raise the RCU softirq if there are callbacks remaining. */ if (cpu_has_callbacks_ready_to_invoke(rdp)) - raise_softirq(RCU_SOFTIRQ); + invoke_rcu_cpu_kthread(); } /* @@ -1225,7 +1281,7 @@ void rcu_check_callbacks(int cpu, int user) } rcu_preempt_check_callbacks(cpu); if (rcu_pending(cpu)) - raise_softirq(RCU_SOFTIRQ); + invoke_rcu_cpu_kthread(); } #ifdef CONFIG_SMP @@ -1233,6 +1289,8 @@ void rcu_check_callbacks(int cpu, int user) /* * Scan the leaf rcu_node structures, processing dyntick state for any that * have not yet encountered a quiescent state, using the function specified. + * Also initiate boosting for any threads blocked on the root rcu_node. + * * The caller must have suppressed start of new grace periods. */ static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *)) @@ -1251,7 +1309,7 @@ static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *)) return; } if (rnp->qsmask == 0) { - raw_spin_unlock_irqrestore(&rnp->lock, flags); + rcu_initiate_boost(rnp, flags); /* releases rnp->lock */ continue; } cpu = rnp->grplo; @@ -1269,6 +1327,11 @@ static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *)) } raw_spin_unlock_irqrestore(&rnp->lock, flags); } + rnp = rcu_get_root(rsp); + if (rnp->qsmask == 0) { + raw_spin_lock_irqsave(&rnp->lock, flags); + rcu_initiate_boost(rnp, flags); /* releases rnp->lock. */ + } } /* @@ -1389,7 +1452,7 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp) /* * Do softirq processing for the current CPU. */ -static void rcu_process_callbacks(struct softirq_action *unused) +static void rcu_process_callbacks(void) { /* * Memory references from any prior RCU read-side critical sections @@ -1414,6 +1477,347 @@ static void rcu_process_callbacks(struct softirq_action *unused) rcu_needs_cpu_flush(); } +/* + * Wake up the current CPU's kthread. This replaces raise_softirq() + * in earlier versions of RCU. Note that because we are running on + * the current CPU with interrupts disabled, the rcu_cpu_kthread_task + * cannot disappear out from under us. + */ +static void invoke_rcu_cpu_kthread(void) +{ + unsigned long flags; + + local_irq_save(flags); + __this_cpu_write(rcu_cpu_has_work, 1); + if (__this_cpu_read(rcu_cpu_kthread_task) == NULL) { + local_irq_restore(flags); + return; + } + wake_up(&__get_cpu_var(rcu_cpu_wq)); + local_irq_restore(flags); +} + +/* + * Wake up the specified per-rcu_node-structure kthread. + * Because the per-rcu_node kthreads are immortal, we don't need + * to do anything to keep them alive. + */ +static void invoke_rcu_node_kthread(struct rcu_node *rnp) +{ + struct task_struct *t; + + t = rnp->node_kthread_task; + if (t != NULL) + wake_up_process(t); +} + +/* + * Set the specified CPU's kthread to run RT or not, as specified by + * the to_rt argument. The CPU-hotplug locks are held, so the task + * is not going away. + */ +static void rcu_cpu_kthread_setrt(int cpu, int to_rt) +{ + int policy; + struct sched_param sp; + struct task_struct *t; + + t = per_cpu(rcu_cpu_kthread_task, cpu); + if (t == NULL) + return; + if (to_rt) { + policy = SCHED_FIFO; + sp.sched_priority = RCU_KTHREAD_PRIO; + } else { + policy = SCHED_NORMAL; + sp.sched_priority = 0; + } + sched_setscheduler_nocheck(t, policy, &sp); +} + +/* + * Timer handler to initiate the waking up of per-CPU kthreads that + * have yielded the CPU due to excess numbers of RCU callbacks. + * We wake up the per-rcu_node kthread, which in turn will wake up + * the booster kthread. + */ +static void rcu_cpu_kthread_timer(unsigned long arg) +{ + unsigned long flags; + struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, arg); + struct rcu_node *rnp = rdp->mynode; + + raw_spin_lock_irqsave(&rnp->lock, flags); + rnp->wakemask |= rdp->grpmask; + raw_spin_unlock_irqrestore(&rnp->lock, flags); + invoke_rcu_node_kthread(rnp); +} + +/* + * Drop to non-real-time priority and yield, but only after posting a + * timer that will cause us to regain our real-time priority if we + * remain preempted. Either way, we restore our real-time priority + * before returning. + */ +static void rcu_yield(void (*f)(unsigned long), unsigned long arg) +{ + struct sched_param sp; + struct timer_list yield_timer; + + setup_timer_on_stack(&yield_timer, f, arg); + mod_timer(&yield_timer, jiffies + 2); + sp.sched_priority = 0; + sched_setscheduler_nocheck(current, SCHED_NORMAL, &sp); + set_user_nice(current, 19); + schedule(); + sp.sched_priority = RCU_KTHREAD_PRIO; + sched_setscheduler_nocheck(current, SCHED_FIFO, &sp); + del_timer(&yield_timer); +} + +/* + * Handle cases where the rcu_cpu_kthread() ends up on the wrong CPU. + * This can happen while the corresponding CPU is either coming online + * or going offline. We cannot wait until the CPU is fully online + * before starting the kthread, because the various notifier functions + * can wait for RCU grace periods. So we park rcu_cpu_kthread() until + * the corresponding CPU is online. + * + * Return 1 if the kthread needs to stop, 0 otherwise. + * + * Caller must disable bh. This function can momentarily enable it. + */ +static int rcu_cpu_kthread_should_stop(int cpu) +{ + while (cpu_is_offline(cpu) || + !cpumask_equal(¤t->cpus_allowed, cpumask_of(cpu)) || + smp_processor_id() != cpu) { + if (kthread_should_stop()) + return 1; + per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU; + per_cpu(rcu_cpu_kthread_cpu, cpu) = raw_smp_processor_id(); + local_bh_enable(); + schedule_timeout_uninterruptible(1); + if (!cpumask_equal(¤t->cpus_allowed, cpumask_of(cpu))) + set_cpus_allowed_ptr(current, cpumask_of(cpu)); + local_bh_disable(); + } + per_cpu(rcu_cpu_kthread_cpu, cpu) = cpu; + return 0; +} + +/* + * Per-CPU kernel thread that invokes RCU callbacks. This replaces the + * earlier RCU softirq. + */ +static int rcu_cpu_kthread(void *arg) +{ + int cpu = (int)(long)arg; + unsigned long flags; + int spincnt = 0; + unsigned int *statusp = &per_cpu(rcu_cpu_kthread_status, cpu); + wait_queue_head_t *wqp = &per_cpu(rcu_cpu_wq, cpu); + char work; + char *workp = &per_cpu(rcu_cpu_has_work, cpu); + + for (;;) { + *statusp = RCU_KTHREAD_WAITING; + wait_event_interruptible(*wqp, + *workp != 0 || kthread_should_stop()); + local_bh_disable(); + if (rcu_cpu_kthread_should_stop(cpu)) { + local_bh_enable(); + break; + } + *statusp = RCU_KTHREAD_RUNNING; + per_cpu(rcu_cpu_kthread_loops, cpu)++; + local_irq_save(flags); + work = *workp; + *workp = 0; + local_irq_restore(flags); + if (work) + rcu_process_callbacks(); + local_bh_enable(); + if (*workp != 0) + spincnt++; + else + spincnt = 0; + if (spincnt > 10) { + *statusp = RCU_KTHREAD_YIELDING; + rcu_yield(rcu_cpu_kthread_timer, (unsigned long)cpu); + spincnt = 0; + } + } + *statusp = RCU_KTHREAD_STOPPED; + return 0; +} + +/* + * Spawn a per-CPU kthread, setting up affinity and priority. + * Because the CPU hotplug lock is held, no other CPU will be attempting + * to manipulate rcu_cpu_kthread_task. There might be another CPU + * attempting to access it during boot, but the locking in kthread_bind() + * will enforce sufficient ordering. + */ +static int __cpuinit rcu_spawn_one_cpu_kthread(int cpu) +{ + struct sched_param sp; + struct task_struct *t; + + if (!rcu_kthreads_spawnable || + per_cpu(rcu_cpu_kthread_task, cpu) != NULL) + return 0; + t = kthread_create(rcu_cpu_kthread, (void *)(long)cpu, "rcuc%d", cpu); + if (IS_ERR(t)) + return PTR_ERR(t); + kthread_bind(t, cpu); + per_cpu(rcu_cpu_kthread_cpu, cpu) = cpu; + WARN_ON_ONCE(per_cpu(rcu_cpu_kthread_task, cpu) != NULL); + per_cpu(rcu_cpu_kthread_task, cpu) = t; + wake_up_process(t); + sp.sched_priority = RCU_KTHREAD_PRIO; + sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); + return 0; +} + +/* + * Per-rcu_node kthread, which is in charge of waking up the per-CPU + * kthreads when needed. We ignore requests to wake up kthreads + * for offline CPUs, which is OK because force_quiescent_state() + * takes care of this case. + */ +static int rcu_node_kthread(void *arg) +{ + int cpu; + unsigned long flags; + unsigned long mask; + struct rcu_node *rnp = (struct rcu_node *)arg; + struct sched_param sp; + struct task_struct *t; + + for (;;) { + rnp->node_kthread_status = RCU_KTHREAD_WAITING; + wait_event_interruptible(rnp->node_wq, rnp->wakemask != 0); + rnp->node_kthread_status = RCU_KTHREAD_RUNNING; + raw_spin_lock_irqsave(&rnp->lock, flags); + mask = rnp->wakemask; + rnp->wakemask = 0; + rcu_initiate_boost(rnp, flags); /* releases rnp->lock. */ + for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask >>= 1) { + if ((mask & 0x1) == 0) + continue; + preempt_disable(); + t = per_cpu(rcu_cpu_kthread_task, cpu); + if (!cpu_online(cpu) || t == NULL) { + preempt_enable(); + continue; + } + per_cpu(rcu_cpu_has_work, cpu) = 1; + sp.sched_priority = RCU_KTHREAD_PRIO; + sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); + preempt_enable(); + } + } + /* NOTREACHED */ + rnp->node_kthread_status = RCU_KTHREAD_STOPPED; + return 0; +} + +/* + * Set the per-rcu_node kthread's affinity to cover all CPUs that are + * served by the rcu_node in question. The CPU hotplug lock is still + * held, so the value of rnp->qsmaskinit will be stable. + * + * We don't include outgoingcpu in the affinity set, use -1 if there is + * no outgoing CPU. If there are no CPUs left in the affinity set, + * this function allows the kthread to execute on any CPU. + */ +static void rcu_node_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu) +{ + cpumask_var_t cm; + int cpu; + unsigned long mask = rnp->qsmaskinit; + + if (rnp->node_kthread_task == NULL) + return; + if (!alloc_cpumask_var(&cm, GFP_KERNEL)) + return; + cpumask_clear(cm); + for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask >>= 1) + if ((mask & 0x1) && cpu != outgoingcpu) + cpumask_set_cpu(cpu, cm); + if (cpumask_weight(cm) == 0) { + cpumask_setall(cm); + for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++) + cpumask_clear_cpu(cpu, cm); + WARN_ON_ONCE(cpumask_weight(cm) == 0); + } + set_cpus_allowed_ptr(rnp->node_kthread_task, cm); + rcu_boost_kthread_setaffinity(rnp, cm); + free_cpumask_var(cm); +} + +/* + * Spawn a per-rcu_node kthread, setting priority and affinity. + * Called during boot before online/offline can happen, or, if + * during runtime, with the main CPU-hotplug locks held. So only + * one of these can be executing at a time. + */ +static int __cpuinit rcu_spawn_one_node_kthread(struct rcu_state *rsp, + struct rcu_node *rnp) +{ + unsigned long flags; + int rnp_index = rnp - &rsp->node[0]; + struct sched_param sp; + struct task_struct *t; + + if (!rcu_kthreads_spawnable || + rnp->qsmaskinit == 0) + return 0; + if (rnp->node_kthread_task == NULL) { + t = kthread_create(rcu_node_kthread, (void *)rnp, + "rcun%d", rnp_index); + if (IS_ERR(t)) + return PTR_ERR(t); + raw_spin_lock_irqsave(&rnp->lock, flags); + rnp->node_kthread_task = t; + raw_spin_unlock_irqrestore(&rnp->lock, flags); + wake_up_process(t); + sp.sched_priority = 99; + sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); + } + return rcu_spawn_one_boost_kthread(rsp, rnp, rnp_index); +} + +/* + * Spawn all kthreads -- called as soon as the scheduler is running. + */ +static int __init rcu_spawn_kthreads(void) +{ + int cpu; + struct rcu_node *rnp; + + rcu_kthreads_spawnable = 1; + for_each_possible_cpu(cpu) { + init_waitqueue_head(&per_cpu(rcu_cpu_wq, cpu)); + per_cpu(rcu_cpu_has_work, cpu) = 0; + if (cpu_online(cpu)) + (void)rcu_spawn_one_cpu_kthread(cpu); + } + rnp = rcu_get_root(rcu_state); + init_waitqueue_head(&rnp->node_wq); + rcu_init_boost_waitqueue(rnp); + (void)rcu_spawn_one_node_kthread(rcu_state, rnp); + if (NUM_RCU_NODES > 1) + rcu_for_each_leaf_node(rcu_state, rnp) { + init_waitqueue_head(&rnp->node_wq); + rcu_init_boost_waitqueue(rnp); + (void)rcu_spawn_one_node_kthread(rcu_state, rnp); + } + return 0; +} +early_initcall(rcu_spawn_kthreads); + static void __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu), struct rcu_state *rsp) @@ -1439,6 +1843,13 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu), /* Add the callback to our list. */ *rdp->nxttail[RCU_NEXT_TAIL] = head; rdp->nxttail[RCU_NEXT_TAIL] = &head->next; + rdp->qlen++; + + /* If interrupts were disabled, don't dive into RCU core. */ + if (irqs_disabled_flags(flags)) { + local_irq_restore(flags); + return; + } /* * Force the grace period if too many callbacks or too long waiting. @@ -1447,7 +1858,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu), * invoking force_quiescent_state() if the newly enqueued callback * is the only one waiting for a grace period to complete. */ - if (unlikely(++rdp->qlen > rdp->qlen_last_fqs_check + qhimark)) { + if (unlikely(rdp->qlen > rdp->qlen_last_fqs_check + qhimark)) { /* Are we ignoring a completed grace period? */ rcu_process_gp_end(rsp, rdp); @@ -1583,7 +1994,7 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp) * or RCU-bh, force a local reschedule. */ rdp->n_rp_qs_pending++; - if (!rdp->preemptable && + if (!rdp->preemptible && ULONG_CMP_LT(ACCESS_ONCE(rsp->jiffies_force_qs) - 1, jiffies)) set_need_resched(); @@ -1760,7 +2171,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) * that this CPU cannot possibly have any RCU callbacks in flight yet. */ static void __cpuinit -rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) +rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible) { unsigned long flags; unsigned long mask; @@ -1772,7 +2183,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable) rdp->passed_quiesc = 0; /* We could be racing with new GP, */ rdp->qs_pending = 1; /* so set up to respond to current GP. */ rdp->beenonline = 1; /* We have now been online. */ - rdp->preemptable = preemptable; + rdp->preemptible = preemptible; rdp->qlen_last_fqs_check = 0; rdp->n_force_qs_snap = rsp->n_force_qs; rdp->blimit = blimit; @@ -1813,6 +2224,19 @@ static void __cpuinit rcu_online_cpu(int cpu) rcu_preempt_init_percpu_data(cpu); } +static void __cpuinit rcu_online_kthreads(int cpu) +{ + struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, cpu); + struct rcu_node *rnp = rdp->mynode; + + /* Fire up the incoming CPU's kthread and leaf rcu_node kthread. */ + if (rcu_kthreads_spawnable) { + (void)rcu_spawn_one_cpu_kthread(cpu); + if (rnp->node_kthread_task == NULL) + (void)rcu_spawn_one_node_kthread(rcu_state, rnp); + } +} + /* * Handle CPU online/offline notification events. */ @@ -1820,11 +2244,23 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { long cpu = (long)hcpu; + struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, cpu); + struct rcu_node *rnp = rdp->mynode; switch (action) { case CPU_UP_PREPARE: case CPU_UP_PREPARE_FROZEN: rcu_online_cpu(cpu); + rcu_online_kthreads(cpu); + break; + case CPU_ONLINE: + case CPU_DOWN_FAILED: + rcu_node_kthread_setaffinity(rnp, -1); + rcu_cpu_kthread_setrt(cpu, 1); + break; + case CPU_DOWN_PREPARE: + rcu_node_kthread_setaffinity(rnp, cpu); + rcu_cpu_kthread_setrt(cpu, 0); break; case CPU_DYING: case CPU_DYING_FROZEN: @@ -1943,10 +2379,7 @@ static void __init rcu_init_one(struct rcu_state *rsp, j / rsp->levelspread[i - 1]; } rnp->level = i; - INIT_LIST_HEAD(&rnp->blocked_tasks[0]); - INIT_LIST_HEAD(&rnp->blocked_tasks[1]); - INIT_LIST_HEAD(&rnp->blocked_tasks[2]); - INIT_LIST_HEAD(&rnp->blocked_tasks[3]); + INIT_LIST_HEAD(&rnp->blkd_tasks); } } @@ -1968,7 +2401,6 @@ void __init rcu_init(void) rcu_init_one(&rcu_sched_state, &rcu_sched_data); rcu_init_one(&rcu_bh_state, &rcu_bh_data); __rcu_init_preempt(); - open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); /* * We don't need protection against CPU-hotplug here because diff --git a/kernel/rcutree.h b/kernel/rcutree.h index e8f057e44e3e..257664815d5d 100644 --- a/kernel/rcutree.h +++ b/kernel/rcutree.h @@ -91,6 +91,14 @@ struct rcu_dynticks { /* remains even for nmi from irq handler. */ }; +/* RCU's kthread states for tracing. */ +#define RCU_KTHREAD_STOPPED 0 +#define RCU_KTHREAD_RUNNING 1 +#define RCU_KTHREAD_WAITING 2 +#define RCU_KTHREAD_OFFCPU 3 +#define RCU_KTHREAD_YIELDING 4 +#define RCU_KTHREAD_MAX 4 + /* * Definition for node within the RCU grace-period-detection hierarchy. */ @@ -109,10 +117,11 @@ struct rcu_node { /* an rcu_data structure, otherwise, each */ /* bit corresponds to a child rcu_node */ /* structure. */ - unsigned long expmask; /* Groups that have ->blocked_tasks[] */ + unsigned long expmask; /* Groups that have ->blkd_tasks */ /* elements that need to drain to allow the */ /* current expedited grace period to */ /* complete (only for TREE_PREEMPT_RCU). */ + unsigned long wakemask; /* CPUs whose kthread needs to be awakened. */ unsigned long qsmaskinit; /* Per-GP initial value for qsmask & expmask. */ unsigned long grpmask; /* Mask to apply to parent qsmask. */ @@ -122,11 +131,68 @@ struct rcu_node { u8 grpnum; /* CPU/group number for next level up. */ u8 level; /* root is at level 0. */ struct rcu_node *parent; - struct list_head blocked_tasks[4]; - /* Tasks blocked in RCU read-side critsect. */ - /* Grace period number (->gpnum) x blocked */ - /* by tasks on the (x & 0x1) element of the */ - /* blocked_tasks[] array. */ + struct list_head blkd_tasks; + /* Tasks blocked in RCU read-side critical */ + /* section. Tasks are placed at the head */ + /* of this list and age towards the tail. */ + struct list_head *gp_tasks; + /* Pointer to the first task blocking the */ + /* current grace period, or NULL if there */ + /* is no such task. */ + struct list_head *exp_tasks; + /* Pointer to the first task blocking the */ + /* current expedited grace period, or NULL */ + /* if there is no such task. If there */ + /* is no current expedited grace period, */ + /* then there can cannot be any such task. */ +#ifdef CONFIG_RCU_BOOST + struct list_head *boost_tasks; + /* Pointer to first task that needs to be */ + /* priority boosted, or NULL if no priority */ + /* boosting is needed for this rcu_node */ + /* structure. If there are no tasks */ + /* queued on this rcu_node structure that */ + /* are blocking the current grace period, */ + /* there can be no such task. */ + unsigned long boost_time; + /* When to start boosting (jiffies). */ + struct task_struct *boost_kthread_task; + /* kthread that takes care of priority */ + /* boosting for this rcu_node structure. */ + wait_queue_head_t boost_wq; + /* Wait queue on which to park the boost */ + /* kthread. */ + unsigned int boost_kthread_status; + /* State of boost_kthread_task for tracing. */ + unsigned long n_tasks_boosted; + /* Total number of tasks boosted. */ + unsigned long n_exp_boosts; + /* Number of tasks boosted for expedited GP. */ + unsigned long n_normal_boosts; + /* Number of tasks boosted for normal GP. */ + unsigned long n_balk_blkd_tasks; + /* Refused to boost: no blocked tasks. */ + unsigned long n_balk_exp_gp_tasks; + /* Refused to boost: nothing blocking GP. */ + unsigned long n_balk_boost_tasks; + /* Refused to boost: already boosting. */ + unsigned long n_balk_notblocked; + /* Refused to boost: RCU RS CS still running. */ + unsigned long n_balk_notyet; + /* Refused to boost: not yet time. */ + unsigned long n_balk_nos; + /* Refused to boost: not sure why, though. */ + /* This can happen due to race conditions. */ +#endif /* #ifdef CONFIG_RCU_BOOST */ + struct task_struct *node_kthread_task; + /* kthread that takes care of this rcu_node */ + /* structure, for example, awakening the */ + /* per-CPU kthreads as needed. */ + wait_queue_head_t node_wq; + /* Wait queue on which to park the per-node */ + /* kthread. */ + unsigned int node_kthread_status; + /* State of node_kthread_task for tracing. */ } ____cacheline_internodealigned_in_smp; /* @@ -175,7 +241,7 @@ struct rcu_data { bool passed_quiesc; /* User-mode/idle loop etc. */ bool qs_pending; /* Core waits for quiesc state. */ bool beenonline; /* CPU online at least once. */ - bool preemptable; /* Preemptable RCU? */ + bool preemptible; /* Preemptible RCU? */ struct rcu_node *mynode; /* This CPU's leaf of hierarchy */ unsigned long grpmask; /* Mask to apply to leaf qsmask. */ @@ -254,7 +320,6 @@ struct rcu_data { #endif /* #else #ifdef CONFIG_NO_HZ */ #define RCU_JIFFIES_TILL_FORCE_QS 3 /* for rsp->jiffies_force_qs */ -#ifdef CONFIG_RCU_CPU_STALL_DETECTOR #ifdef CONFIG_PROVE_RCU #define RCU_STALL_DELAY_DELTA (5 * HZ) @@ -272,13 +337,6 @@ struct rcu_data { /* scheduling clock irq */ /* before ratting on them. */ -#ifdef CONFIG_RCU_CPU_STALL_DETECTOR_RUNNABLE -#define RCU_CPU_STALL_SUPPRESS_INIT 0 -#else -#define RCU_CPU_STALL_SUPPRESS_INIT 1 -#endif - -#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ /* * RCU global state, including node hierarchy. This hierarchy is @@ -325,12 +383,12 @@ struct rcu_state { /* due to lock unavailable. */ unsigned long n_force_qs_ngp; /* Number of calls leaving */ /* due to no GP active. */ -#ifdef CONFIG_RCU_CPU_STALL_DETECTOR unsigned long gp_start; /* Time at which GP started, */ /* but in jiffies. */ unsigned long jiffies_stall; /* Time at which to check */ /* for CPU stalls. */ -#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ + unsigned long gp_max; /* Maximum GP duration in */ + /* jiffies. */ char *name; /* Name of structure. */ }; @@ -361,16 +419,14 @@ DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data); static void rcu_bootup_announce(void); long rcu_batches_completed(void); static void rcu_preempt_note_context_switch(int cpu); -static int rcu_preempted_readers(struct rcu_node *rnp); +static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp); #ifdef CONFIG_HOTPLUG_CPU static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags); #endif /* #ifdef CONFIG_HOTPLUG_CPU */ -#ifdef CONFIG_RCU_CPU_STALL_DETECTOR static void rcu_print_detail_task_stall(struct rcu_state *rsp); static void rcu_print_task_stall(struct rcu_node *rnp); static void rcu_preempt_stall_reset(void); -#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp); #ifdef CONFIG_HOTPLUG_CPU static int rcu_preempt_offline_tasks(struct rcu_state *rsp, @@ -390,5 +446,13 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu); static void rcu_preempt_send_cbs_to_online(void); static void __init __rcu_init_preempt(void); static void rcu_needs_cpu_flush(void); +static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp); +static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags); +static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, + cpumask_var_t cm); +static void rcu_preempt_boost_start_gp(struct rcu_node *rnp); +static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp, + struct rcu_node *rnp, + int rnp_index); #endif /* #ifndef RCU_TREE_NONCORE */ diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index a3638710dc67..3f6559a5f5cd 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -1,7 +1,7 @@ /* * Read-Copy Update mechanism for mutual exclusion (tree-based version) * Internal non-public definitions that provide either classic - * or preemptable semantics. + * or preemptible semantics. * * 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 @@ -54,10 +54,6 @@ static void __init rcu_bootup_announce_oddness(void) #ifdef CONFIG_RCU_TORTURE_TEST_RUNNABLE printk(KERN_INFO "\tRCU torture testing starts during boot.\n"); #endif -#ifndef CONFIG_RCU_CPU_STALL_DETECTOR - printk(KERN_INFO - "\tRCU-based detection of stalled CPUs is disabled.\n"); -#endif #if defined(CONFIG_TREE_PREEMPT_RCU) && !defined(CONFIG_RCU_CPU_STALL_VERBOSE) printk(KERN_INFO "\tVerbose stalled-CPUs detection is disabled.\n"); #endif @@ -70,6 +66,7 @@ static void __init rcu_bootup_announce_oddness(void) struct rcu_state rcu_preempt_state = RCU_STATE_INITIALIZER(rcu_preempt_state); DEFINE_PER_CPU(struct rcu_data, rcu_preempt_data); +static struct rcu_state *rcu_state = &rcu_preempt_state; static int rcu_preempted_readers_exp(struct rcu_node *rnp); @@ -78,7 +75,7 @@ static int rcu_preempted_readers_exp(struct rcu_node *rnp); */ static void __init rcu_bootup_announce(void) { - printk(KERN_INFO "Preemptable hierarchical RCU implementation.\n"); + printk(KERN_INFO "Preemptible hierarchical RCU implementation.\n"); rcu_bootup_announce_oddness(); } @@ -111,7 +108,7 @@ void rcu_force_quiescent_state(void) EXPORT_SYMBOL_GPL(rcu_force_quiescent_state); /* - * Record a preemptable-RCU quiescent state for the specified CPU. Note + * Record a preemptible-RCU quiescent state for the specified CPU. Note * that this just means that the task currently running on the CPU is * not in a quiescent state. There might be any number of tasks blocked * while in an RCU read-side critical section. @@ -134,12 +131,12 @@ static void rcu_preempt_qs(int cpu) * We have entered the scheduler, and the current task might soon be * context-switched away from. If this task is in an RCU read-side * critical section, we will no longer be able to rely on the CPU to - * record that fact, so we enqueue the task on the appropriate entry - * of the blocked_tasks[] array. The task will dequeue itself when - * it exits the outermost enclosing RCU read-side critical section. - * Therefore, the current grace period cannot be permitted to complete - * until the blocked_tasks[] entry indexed by the low-order bit of - * rnp->gpnum empties. + * record that fact, so we enqueue the task on the blkd_tasks list. + * The task will dequeue itself when it exits the outermost enclosing + * RCU read-side critical section. Therefore, the current grace period + * cannot be permitted to complete until the blkd_tasks list entries + * predating the current grace period drain, in other words, until + * rnp->gp_tasks becomes NULL. * * Caller must disable preemption. */ @@ -147,7 +144,6 @@ static void rcu_preempt_note_context_switch(int cpu) { struct task_struct *t = current; unsigned long flags; - int phase; struct rcu_data *rdp; struct rcu_node *rnp; @@ -169,15 +165,30 @@ static void rcu_preempt_note_context_switch(int cpu) * (i.e., this CPU has not yet passed through a quiescent * state for the current grace period), then as long * as that task remains queued, the current grace period - * cannot end. + * cannot end. Note that there is some uncertainty as + * to exactly when the current grace period started. + * We take a conservative approach, which can result + * in unnecessarily waiting on tasks that started very + * slightly after the current grace period began. C'est + * la vie!!! * * But first, note that the current CPU must still be * on line! */ WARN_ON_ONCE((rdp->grpmask & rnp->qsmaskinit) == 0); WARN_ON_ONCE(!list_empty(&t->rcu_node_entry)); - phase = (rnp->gpnum + !(rnp->qsmask & rdp->grpmask)) & 0x1; - list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]); + if ((rnp->qsmask & rdp->grpmask) && rnp->gp_tasks != NULL) { + list_add(&t->rcu_node_entry, rnp->gp_tasks->prev); + rnp->gp_tasks = &t->rcu_node_entry; +#ifdef CONFIG_RCU_BOOST + if (rnp->boost_tasks != NULL) + rnp->boost_tasks = rnp->gp_tasks; +#endif /* #ifdef CONFIG_RCU_BOOST */ + } else { + list_add(&t->rcu_node_entry, &rnp->blkd_tasks); + if (rnp->qsmask & rdp->grpmask) + rnp->gp_tasks = &t->rcu_node_entry; + } raw_spin_unlock_irqrestore(&rnp->lock, flags); } @@ -196,7 +207,7 @@ static void rcu_preempt_note_context_switch(int cpu) } /* - * Tree-preemptable RCU implementation for rcu_read_lock(). + * Tree-preemptible RCU implementation for rcu_read_lock(). * Just increment ->rcu_read_lock_nesting, shared state will be updated * if we block. */ @@ -212,12 +223,9 @@ EXPORT_SYMBOL_GPL(__rcu_read_lock); * for the specified rcu_node structure. If the caller needs a reliable * answer, it must hold the rcu_node's ->lock. */ -static int rcu_preempted_readers(struct rcu_node *rnp) +static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp) { - int phase = rnp->gpnum & 0x1; - - return !list_empty(&rnp->blocked_tasks[phase]) || - !list_empty(&rnp->blocked_tasks[phase + 2]); + return rnp->gp_tasks != NULL; } /* @@ -233,7 +241,7 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags) unsigned long mask; struct rcu_node *rnp_p; - if (rnp->qsmask != 0 || rcu_preempted_readers(rnp)) { + if (rnp->qsmask != 0 || rcu_preempt_blocked_readers_cgp(rnp)) { raw_spin_unlock_irqrestore(&rnp->lock, flags); return; /* Still need more quiescent states! */ } @@ -257,6 +265,21 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags) } /* + * Advance a ->blkd_tasks-list pointer to the next entry, instead + * returning NULL if at the end of the list. + */ +static struct list_head *rcu_next_node_entry(struct task_struct *t, + struct rcu_node *rnp) +{ + struct list_head *np; + + np = t->rcu_node_entry.next; + if (np == &rnp->blkd_tasks) + np = NULL; + return np; +} + +/* * Handle special cases during rcu_read_unlock(), such as needing to * notify RCU core processing or task having blocked during the RCU * read-side critical section. @@ -266,6 +289,7 @@ static void rcu_read_unlock_special(struct task_struct *t) int empty; int empty_exp; unsigned long flags; + struct list_head *np; struct rcu_node *rnp; int special; @@ -306,10 +330,19 @@ static void rcu_read_unlock_special(struct task_struct *t) break; raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ } - empty = !rcu_preempted_readers(rnp); + empty = !rcu_preempt_blocked_readers_cgp(rnp); empty_exp = !rcu_preempted_readers_exp(rnp); smp_mb(); /* ensure expedited fastpath sees end of RCU c-s. */ + np = rcu_next_node_entry(t, rnp); list_del_init(&t->rcu_node_entry); + if (&t->rcu_node_entry == rnp->gp_tasks) + rnp->gp_tasks = np; + if (&t->rcu_node_entry == rnp->exp_tasks) + rnp->exp_tasks = np; +#ifdef CONFIG_RCU_BOOST + if (&t->rcu_node_entry == rnp->boost_tasks) + rnp->boost_tasks = np; +#endif /* #ifdef CONFIG_RCU_BOOST */ t->rcu_blocked_node = NULL; /* @@ -322,6 +355,15 @@ static void rcu_read_unlock_special(struct task_struct *t) else rcu_report_unblock_qs_rnp(rnp, flags); +#ifdef CONFIG_RCU_BOOST + /* Unboost if we were boosted. */ + if (special & RCU_READ_UNLOCK_BOOSTED) { + t->rcu_read_unlock_special &= ~RCU_READ_UNLOCK_BOOSTED; + rt_mutex_unlock(t->rcu_boost_mutex); + t->rcu_boost_mutex = NULL; + } +#endif /* #ifdef CONFIG_RCU_BOOST */ + /* * If this was the last task on the expedited lists, * then we need to report up the rcu_node hierarchy. @@ -334,7 +376,7 @@ static void rcu_read_unlock_special(struct task_struct *t) } /* - * Tree-preemptable RCU implementation for rcu_read_unlock(). + * Tree-preemptible RCU implementation for rcu_read_unlock(). * Decrement ->rcu_read_lock_nesting. If the result is zero (outermost * rcu_read_unlock()) and ->rcu_read_unlock_special is non-zero, then * invoke rcu_read_unlock_special() to clean up after a context switch @@ -356,8 +398,6 @@ void __rcu_read_unlock(void) } EXPORT_SYMBOL_GPL(__rcu_read_unlock); -#ifdef CONFIG_RCU_CPU_STALL_DETECTOR - #ifdef CONFIG_RCU_CPU_STALL_VERBOSE /* @@ -367,18 +407,16 @@ EXPORT_SYMBOL_GPL(__rcu_read_unlock); static void rcu_print_detail_task_stall_rnp(struct rcu_node *rnp) { unsigned long flags; - struct list_head *lp; - int phase; struct task_struct *t; - if (rcu_preempted_readers(rnp)) { - raw_spin_lock_irqsave(&rnp->lock, flags); - phase = rnp->gpnum & 0x1; - lp = &rnp->blocked_tasks[phase]; - list_for_each_entry(t, lp, rcu_node_entry) - sched_show_task(t); - raw_spin_unlock_irqrestore(&rnp->lock, flags); - } + if (!rcu_preempt_blocked_readers_cgp(rnp)) + return; + raw_spin_lock_irqsave(&rnp->lock, flags); + t = list_entry(rnp->gp_tasks, + struct task_struct, rcu_node_entry); + list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) + sched_show_task(t); + raw_spin_unlock_irqrestore(&rnp->lock, flags); } /* @@ -408,16 +446,14 @@ static void rcu_print_detail_task_stall(struct rcu_state *rsp) */ static void rcu_print_task_stall(struct rcu_node *rnp) { - struct list_head *lp; - int phase; struct task_struct *t; - if (rcu_preempted_readers(rnp)) { - phase = rnp->gpnum & 0x1; - lp = &rnp->blocked_tasks[phase]; - list_for_each_entry(t, lp, rcu_node_entry) - printk(" P%d", t->pid); - } + if (!rcu_preempt_blocked_readers_cgp(rnp)) + return; + t = list_entry(rnp->gp_tasks, + struct task_struct, rcu_node_entry); + list_for_each_entry_continue(t, &rnp->blkd_tasks, rcu_node_entry) + printk(" P%d", t->pid); } /* @@ -430,18 +466,21 @@ static void rcu_preempt_stall_reset(void) rcu_preempt_state.jiffies_stall = jiffies + ULONG_MAX / 2; } -#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ - /* * Check that the list of blocked tasks for the newly completed grace * period is in fact empty. It is a serious bug to complete a grace * period that still has RCU readers blocked! This function must be * invoked -before- updating this rnp's ->gpnum, and the rnp's ->lock * must be held by the caller. + * + * Also, if there are blocked tasks on the list, they automatically + * block the newly created grace period, so set up ->gp_tasks accordingly. */ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) { - WARN_ON_ONCE(rcu_preempted_readers(rnp)); + WARN_ON_ONCE(rcu_preempt_blocked_readers_cgp(rnp)); + if (!list_empty(&rnp->blkd_tasks)) + rnp->gp_tasks = rnp->blkd_tasks.next; WARN_ON_ONCE(rnp->qsmask); } @@ -465,50 +504,68 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp) { - int i; struct list_head *lp; struct list_head *lp_root; int retval = 0; struct rcu_node *rnp_root = rcu_get_root(rsp); - struct task_struct *tp; + struct task_struct *t; if (rnp == rnp_root) { WARN_ONCE(1, "Last CPU thought to be offlined?"); return 0; /* Shouldn't happen: at least one CPU online. */ } - WARN_ON_ONCE(rnp != rdp->mynode && - (!list_empty(&rnp->blocked_tasks[0]) || - !list_empty(&rnp->blocked_tasks[1]) || - !list_empty(&rnp->blocked_tasks[2]) || - !list_empty(&rnp->blocked_tasks[3]))); + + /* If we are on an internal node, complain bitterly. */ + WARN_ON_ONCE(rnp != rdp->mynode); /* - * Move tasks up to root rcu_node. Rely on the fact that the - * root rcu_node can be at most one ahead of the rest of the - * rcu_nodes in terms of gp_num value. This fact allows us to - * move the blocked_tasks[] array directly, element by element. + * Move tasks up to root rcu_node. Don't try to get fancy for + * this corner-case operation -- just put this node's tasks + * at the head of the root node's list, and update the root node's + * ->gp_tasks and ->exp_tasks pointers to those of this node's, + * if non-NULL. This might result in waiting for more tasks than + * absolutely necessary, but this is a good performance/complexity + * tradeoff. */ - if (rcu_preempted_readers(rnp)) + if (rcu_preempt_blocked_readers_cgp(rnp)) retval |= RCU_OFL_TASKS_NORM_GP; if (rcu_preempted_readers_exp(rnp)) retval |= RCU_OFL_TASKS_EXP_GP; - for (i = 0; i < 4; i++) { - lp = &rnp->blocked_tasks[i]; - lp_root = &rnp_root->blocked_tasks[i]; - while (!list_empty(lp)) { - tp = list_entry(lp->next, typeof(*tp), rcu_node_entry); - raw_spin_lock(&rnp_root->lock); /* irqs already disabled */ - list_del(&tp->rcu_node_entry); - tp->rcu_blocked_node = rnp_root; - list_add(&tp->rcu_node_entry, lp_root); - raw_spin_unlock(&rnp_root->lock); /* irqs remain disabled */ - } + lp = &rnp->blkd_tasks; + lp_root = &rnp_root->blkd_tasks; + while (!list_empty(lp)) { + t = list_entry(lp->next, typeof(*t), rcu_node_entry); + raw_spin_lock(&rnp_root->lock); /* irqs already disabled */ + list_del(&t->rcu_node_entry); + t->rcu_blocked_node = rnp_root; + list_add(&t->rcu_node_entry, lp_root); + if (&t->rcu_node_entry == rnp->gp_tasks) + rnp_root->gp_tasks = rnp->gp_tasks; + if (&t->rcu_node_entry == rnp->exp_tasks) + rnp_root->exp_tasks = rnp->exp_tasks; +#ifdef CONFIG_RCU_BOOST + if (&t->rcu_node_entry == rnp->boost_tasks) + rnp_root->boost_tasks = rnp->boost_tasks; +#endif /* #ifdef CONFIG_RCU_BOOST */ + raw_spin_unlock(&rnp_root->lock); /* irqs still disabled */ } + +#ifdef CONFIG_RCU_BOOST + /* In case root is being boosted and leaf is not. */ + raw_spin_lock(&rnp_root->lock); /* irqs already disabled */ + if (rnp_root->boost_tasks != NULL && + rnp_root->boost_tasks != rnp_root->gp_tasks) + rnp_root->boost_tasks = rnp_root->gp_tasks; + raw_spin_unlock(&rnp_root->lock); /* irqs still disabled */ +#endif /* #ifdef CONFIG_RCU_BOOST */ + + rnp->gp_tasks = NULL; + rnp->exp_tasks = NULL; return retval; } /* - * Do CPU-offline processing for preemptable RCU. + * Do CPU-offline processing for preemptible RCU. */ static void rcu_preempt_offline_cpu(int cpu) { @@ -537,7 +594,7 @@ static void rcu_preempt_check_callbacks(int cpu) } /* - * Process callbacks for preemptable RCU. + * Process callbacks for preemptible RCU. */ static void rcu_preempt_process_callbacks(void) { @@ -546,7 +603,7 @@ static void rcu_preempt_process_callbacks(void) } /* - * Queue a preemptable-RCU callback for invocation after a grace period. + * Queue a preemptible-RCU callback for invocation after a grace period. */ void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu)) { @@ -594,8 +651,7 @@ static DEFINE_MUTEX(sync_rcu_preempt_exp_mutex); */ static int rcu_preempted_readers_exp(struct rcu_node *rnp) { - return !list_empty(&rnp->blocked_tasks[2]) || - !list_empty(&rnp->blocked_tasks[3]); + return rnp->exp_tasks != NULL; } /* @@ -655,13 +711,17 @@ static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp) static void sync_rcu_preempt_exp_init(struct rcu_state *rsp, struct rcu_node *rnp) { - int must_wait; + unsigned long flags; + int must_wait = 0; - raw_spin_lock(&rnp->lock); /* irqs already disabled */ - list_splice_init(&rnp->blocked_tasks[0], &rnp->blocked_tasks[2]); - list_splice_init(&rnp->blocked_tasks[1], &rnp->blocked_tasks[3]); - must_wait = rcu_preempted_readers_exp(rnp); - raw_spin_unlock(&rnp->lock); /* irqs remain disabled */ + raw_spin_lock_irqsave(&rnp->lock, flags); + if (list_empty(&rnp->blkd_tasks)) + raw_spin_unlock_irqrestore(&rnp->lock, flags); + else { + rnp->exp_tasks = rnp->blkd_tasks.next; + rcu_initiate_boost(rnp, flags); /* releases rnp->lock */ + must_wait = 1; + } if (!must_wait) rcu_report_exp_rnp(rsp, rnp); } @@ -669,9 +729,7 @@ sync_rcu_preempt_exp_init(struct rcu_state *rsp, struct rcu_node *rnp) /* * Wait for an rcu-preempt grace period, but expedite it. The basic idea * is to invoke synchronize_sched_expedited() to push all the tasks to - * the ->blocked_tasks[] lists, move all entries from the first set of - * ->blocked_tasks[] lists to the second set, and finally wait for this - * second set to drain. + * the ->blkd_tasks lists and wait for this list to drain. */ void synchronize_rcu_expedited(void) { @@ -703,7 +761,7 @@ void synchronize_rcu_expedited(void) if ((ACCESS_ONCE(sync_rcu_preempt_exp_count) - snap) > 0) goto unlock_mb_ret; /* Others did our work for us. */ - /* force all RCU readers onto blocked_tasks[]. */ + /* force all RCU readers onto ->blkd_tasks lists. */ synchronize_sched_expedited(); raw_spin_lock_irqsave(&rsp->onofflock, flags); @@ -715,7 +773,7 @@ void synchronize_rcu_expedited(void) raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */ } - /* Snapshot current state of ->blocked_tasks[] lists. */ + /* Snapshot current state of ->blkd_tasks lists. */ rcu_for_each_leaf_node(rsp, rnp) sync_rcu_preempt_exp_init(rsp, rnp); if (NUM_RCU_NODES > 1) @@ -723,7 +781,7 @@ void synchronize_rcu_expedited(void) raw_spin_unlock_irqrestore(&rsp->onofflock, flags); - /* Wait for snapshotted ->blocked_tasks[] lists to drain. */ + /* Wait for snapshotted ->blkd_tasks lists to drain. */ rnp = rcu_get_root(rsp); wait_event(sync_rcu_preempt_exp_wq, sync_rcu_preempt_exp_done(rnp)); @@ -739,7 +797,7 @@ mb_ret: EXPORT_SYMBOL_GPL(synchronize_rcu_expedited); /* - * Check to see if there is any immediate preemptable-RCU-related work + * Check to see if there is any immediate preemptible-RCU-related work * to be done. */ static int rcu_preempt_pending(int cpu) @@ -749,7 +807,7 @@ static int rcu_preempt_pending(int cpu) } /* - * Does preemptable RCU need the CPU to stay out of dynticks mode? + * Does preemptible RCU need the CPU to stay out of dynticks mode? */ static int rcu_preempt_needs_cpu(int cpu) { @@ -766,7 +824,7 @@ void rcu_barrier(void) EXPORT_SYMBOL_GPL(rcu_barrier); /* - * Initialize preemptable RCU's per-CPU data. + * Initialize preemptible RCU's per-CPU data. */ static void __cpuinit rcu_preempt_init_percpu_data(int cpu) { @@ -774,7 +832,7 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu) } /* - * Move preemptable RCU's callbacks from dying CPU to other online CPU. + * Move preemptible RCU's callbacks from dying CPU to other online CPU. */ static void rcu_preempt_send_cbs_to_online(void) { @@ -782,7 +840,7 @@ static void rcu_preempt_send_cbs_to_online(void) } /* - * Initialize preemptable RCU's state structures. + * Initialize preemptible RCU's state structures. */ static void __init __rcu_init_preempt(void) { @@ -790,7 +848,7 @@ static void __init __rcu_init_preempt(void) } /* - * Check for a task exiting while in a preemptable-RCU read-side + * Check for a task exiting while in a preemptible-RCU read-side * critical section, clean up if so. No need to issue warnings, * as debug_check_no_locks_held() already does this if lockdep * is enabled. @@ -802,11 +860,13 @@ void exit_rcu(void) if (t->rcu_read_lock_nesting == 0) return; t->rcu_read_lock_nesting = 1; - rcu_read_unlock(); + __rcu_read_unlock(); } #else /* #ifdef CONFIG_TREE_PREEMPT_RCU */ +static struct rcu_state *rcu_state = &rcu_sched_state; + /* * Tell them what RCU they are running. */ @@ -836,7 +896,7 @@ void rcu_force_quiescent_state(void) EXPORT_SYMBOL_GPL(rcu_force_quiescent_state); /* - * Because preemptable RCU does not exist, we never have to check for + * Because preemptible RCU does not exist, we never have to check for * CPUs being in quiescent states. */ static void rcu_preempt_note_context_switch(int cpu) @@ -844,10 +904,10 @@ static void rcu_preempt_note_context_switch(int cpu) } /* - * Because preemptable RCU does not exist, there are never any preempted + * Because preemptible RCU does not exist, there are never any preempted * RCU readers. */ -static int rcu_preempted_readers(struct rcu_node *rnp) +static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp) { return 0; } @@ -862,10 +922,8 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags) #endif /* #ifdef CONFIG_HOTPLUG_CPU */ -#ifdef CONFIG_RCU_CPU_STALL_DETECTOR - /* - * Because preemptable RCU does not exist, we never have to check for + * Because preemptible RCU does not exist, we never have to check for * tasks blocked within RCU read-side critical sections. */ static void rcu_print_detail_task_stall(struct rcu_state *rsp) @@ -873,7 +931,7 @@ static void rcu_print_detail_task_stall(struct rcu_state *rsp) } /* - * Because preemptable RCU does not exist, we never have to check for + * Because preemptible RCU does not exist, we never have to check for * tasks blocked within RCU read-side critical sections. */ static void rcu_print_task_stall(struct rcu_node *rnp) @@ -888,10 +946,8 @@ static void rcu_preempt_stall_reset(void) { } -#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */ - /* - * Because there is no preemptable RCU, there can be no readers blocked, + * Because there is no preemptible RCU, there can be no readers blocked, * so there is no need to check for blocked tasks. So check only for * bogus qsmask values. */ @@ -903,7 +959,7 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) #ifdef CONFIG_HOTPLUG_CPU /* - * Because preemptable RCU does not exist, it never needs to migrate + * Because preemptible RCU does not exist, it never needs to migrate * tasks that were blocked within RCU read-side critical sections, and * such non-existent tasks cannot possibly have been blocking the current * grace period. @@ -916,7 +972,7 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp, } /* - * Because preemptable RCU does not exist, it never needs CPU-offline + * Because preemptible RCU does not exist, it never needs CPU-offline * processing. */ static void rcu_preempt_offline_cpu(int cpu) @@ -926,7 +982,7 @@ static void rcu_preempt_offline_cpu(int cpu) #endif /* #ifdef CONFIG_HOTPLUG_CPU */ /* - * Because preemptable RCU does not exist, it never has any callbacks + * Because preemptible RCU does not exist, it never has any callbacks * to check. */ static void rcu_preempt_check_callbacks(int cpu) @@ -934,7 +990,7 @@ static void rcu_preempt_check_callbacks(int cpu) } /* - * Because preemptable RCU does not exist, it never has any callbacks + * Because preemptible RCU does not exist, it never has any callbacks * to process. */ static void rcu_preempt_process_callbacks(void) @@ -943,7 +999,7 @@ static void rcu_preempt_process_callbacks(void) /* * Wait for an rcu-preempt grace period, but make it happen quickly. - * But because preemptable RCU does not exist, map to rcu-sched. + * But because preemptible RCU does not exist, map to rcu-sched. */ void synchronize_rcu_expedited(void) { @@ -954,7 +1010,7 @@ EXPORT_SYMBOL_GPL(synchronize_rcu_expedited); #ifdef CONFIG_HOTPLUG_CPU /* - * Because preemptable RCU does not exist, there is never any need to + * Because preemptible RCU does not exist, there is never any need to * report on tasks preempted in RCU read-side critical sections during * expedited RCU grace periods. */ @@ -966,7 +1022,7 @@ static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp) #endif /* #ifdef CONFIG_HOTPLUG_CPU */ /* - * Because preemptable RCU does not exist, it never has any work to do. + * Because preemptible RCU does not exist, it never has any work to do. */ static int rcu_preempt_pending(int cpu) { @@ -974,7 +1030,7 @@ static int rcu_preempt_pending(int cpu) } /* - * Because preemptable RCU does not exist, it never needs any CPU. + * Because preemptible RCU does not exist, it never needs any CPU. */ static int rcu_preempt_needs_cpu(int cpu) { @@ -982,7 +1038,7 @@ static int rcu_preempt_needs_cpu(int cpu) } /* - * Because preemptable RCU does not exist, rcu_barrier() is just + * Because preemptible RCU does not exist, rcu_barrier() is just * another name for rcu_barrier_sched(). */ void rcu_barrier(void) @@ -992,7 +1048,7 @@ void rcu_barrier(void) EXPORT_SYMBOL_GPL(rcu_barrier); /* - * Because preemptable RCU does not exist, there is no per-CPU + * Because preemptible RCU does not exist, there is no per-CPU * data to initialize. */ static void __cpuinit rcu_preempt_init_percpu_data(int cpu) @@ -1000,14 +1056,14 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu) } /* - * Because there is no preemptable RCU, there are no callbacks to move. + * Because there is no preemptible RCU, there are no callbacks to move. */ static void rcu_preempt_send_cbs_to_online(void) { } /* - * Because preemptable RCU does not exist, it need not be initialized. + * Because preemptible RCU does not exist, it need not be initialized. */ static void __init __rcu_init_preempt(void) { @@ -1015,6 +1071,276 @@ static void __init __rcu_init_preempt(void) #endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */ +#ifdef CONFIG_RCU_BOOST + +#include "rtmutex_common.h" + +#ifdef CONFIG_RCU_TRACE + +static void rcu_initiate_boost_trace(struct rcu_node *rnp) +{ + if (list_empty(&rnp->blkd_tasks)) + rnp->n_balk_blkd_tasks++; + else if (rnp->exp_tasks == NULL && rnp->gp_tasks == NULL) + rnp->n_balk_exp_gp_tasks++; + else if (rnp->gp_tasks != NULL && rnp->boost_tasks != NULL) + rnp->n_balk_boost_tasks++; + else if (rnp->gp_tasks != NULL && rnp->qsmask != 0) + rnp->n_balk_notblocked++; + else if (rnp->gp_tasks != NULL && + ULONG_CMP_LT(jiffies, rnp->boost_time)) + rnp->n_balk_notyet++; + else + rnp->n_balk_nos++; +} + +#else /* #ifdef CONFIG_RCU_TRACE */ + +static void rcu_initiate_boost_trace(struct rcu_node *rnp) +{ +} + +#endif /* #else #ifdef CONFIG_RCU_TRACE */ + +/* + * Carry out RCU priority boosting on the task indicated by ->exp_tasks + * or ->boost_tasks, advancing the pointer to the next task in the + * ->blkd_tasks list. + * + * Note that irqs must be enabled: boosting the task can block. + * Returns 1 if there are more tasks needing to be boosted. + */ +static int rcu_boost(struct rcu_node *rnp) +{ + unsigned long flags; + struct rt_mutex mtx; + struct task_struct *t; + struct list_head *tb; + + if (rnp->exp_tasks == NULL && rnp->boost_tasks == NULL) + return 0; /* Nothing left to boost. */ + + raw_spin_lock_irqsave(&rnp->lock, flags); + + /* + * Recheck under the lock: all tasks in need of boosting + * might exit their RCU read-side critical sections on their own. + */ + if (rnp->exp_tasks == NULL && rnp->boost_tasks == NULL) { + raw_spin_unlock_irqrestore(&rnp->lock, flags); + return 0; + } + + /* + * Preferentially boost tasks blocking expedited grace periods. + * This cannot starve the normal grace periods because a second + * expedited grace period must boost all blocked tasks, including + * those blocking the pre-existing normal grace period. + */ + if (rnp->exp_tasks != NULL) { + tb = rnp->exp_tasks; + rnp->n_exp_boosts++; + } else { + tb = rnp->boost_tasks; + rnp->n_normal_boosts++; + } + rnp->n_tasks_boosted++; + + /* + * We boost task t by manufacturing an rt_mutex that appears to + * be held by task t. We leave a pointer to that rt_mutex where + * task t can find it, and task t will release the mutex when it + * exits its outermost RCU read-side critical section. Then + * simply acquiring this artificial rt_mutex will boost task + * t's priority. (Thanks to tglx for suggesting this approach!) + * + * Note that task t must acquire rnp->lock to remove itself from + * the ->blkd_tasks list, which it will do from exit() if from + * nowhere else. We therefore are guaranteed that task t will + * stay around at least until we drop rnp->lock. Note that + * rnp->lock also resolves races between our priority boosting + * and task t's exiting its outermost RCU read-side critical + * section. + */ + t = container_of(tb, struct task_struct, rcu_node_entry); + rt_mutex_init_proxy_locked(&mtx, t); + t->rcu_boost_mutex = &mtx; + t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BOOSTED; + raw_spin_unlock_irqrestore(&rnp->lock, flags); + rt_mutex_lock(&mtx); /* Side effect: boosts task t's priority. */ + rt_mutex_unlock(&mtx); /* Keep lockdep happy. */ + + return rnp->exp_tasks != NULL || rnp->boost_tasks != NULL; +} + +/* + * Timer handler to initiate waking up of boost kthreads that + * have yielded the CPU due to excessive numbers of tasks to + * boost. We wake up the per-rcu_node kthread, which in turn + * will wake up the booster kthread. + */ +static void rcu_boost_kthread_timer(unsigned long arg) +{ + invoke_rcu_node_kthread((struct rcu_node *)arg); +} + +/* + * Priority-boosting kthread. One per leaf rcu_node and one for the + * root rcu_node. + */ +static int rcu_boost_kthread(void *arg) +{ + struct rcu_node *rnp = (struct rcu_node *)arg; + int spincnt = 0; + int more2boost; + + for (;;) { + rnp->boost_kthread_status = RCU_KTHREAD_WAITING; + wait_event_interruptible(rnp->boost_wq, rnp->boost_tasks || + rnp->exp_tasks); + rnp->boost_kthread_status = RCU_KTHREAD_RUNNING; + more2boost = rcu_boost(rnp); + if (more2boost) + spincnt++; + else + spincnt = 0; + if (spincnt > 10) { + rcu_yield(rcu_boost_kthread_timer, (unsigned long)rnp); + spincnt = 0; + } + } + /* NOTREACHED */ + return 0; +} + +/* + * Check to see if it is time to start boosting RCU readers that are + * blocking the current grace period, and, if so, tell the per-rcu_node + * kthread to start boosting them. If there is an expedited grace + * period in progress, it is always time to boost. + * + * The caller must hold rnp->lock, which this function releases, + * but irqs remain disabled. The ->boost_kthread_task is immortal, + * so we don't need to worry about it going away. + */ +static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags) +{ + struct task_struct *t; + + if (!rcu_preempt_blocked_readers_cgp(rnp) && rnp->exp_tasks == NULL) { + rnp->n_balk_exp_gp_tasks++; + raw_spin_unlock_irqrestore(&rnp->lock, flags); + return; + } + if (rnp->exp_tasks != NULL || + (rnp->gp_tasks != NULL && + rnp->boost_tasks == NULL && + rnp->qsmask == 0 && + ULONG_CMP_GE(jiffies, rnp->boost_time))) { + if (rnp->exp_tasks == NULL) + rnp->boost_tasks = rnp->gp_tasks; + raw_spin_unlock_irqrestore(&rnp->lock, flags); + t = rnp->boost_kthread_task; + if (t != NULL) + wake_up_process(t); + } else { + rcu_initiate_boost_trace(rnp); + raw_spin_unlock_irqrestore(&rnp->lock, flags); + } +} + +/* + * Set the affinity of the boost kthread. The CPU-hotplug locks are + * held, so no one should be messing with the existence of the boost + * kthread. + */ +static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, + cpumask_var_t cm) +{ + struct task_struct *t; + + t = rnp->boost_kthread_task; + if (t != NULL) + set_cpus_allowed_ptr(rnp->boost_kthread_task, cm); +} + +#define RCU_BOOST_DELAY_JIFFIES DIV_ROUND_UP(CONFIG_RCU_BOOST_DELAY * HZ, 1000) + +/* + * Do priority-boost accounting for the start of a new grace period. + */ +static void rcu_preempt_boost_start_gp(struct rcu_node *rnp) +{ + rnp->boost_time = jiffies + RCU_BOOST_DELAY_JIFFIES; +} + +/* + * Initialize the RCU-boost waitqueue. + */ +static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp) +{ + init_waitqueue_head(&rnp->boost_wq); +} + +/* + * Create an RCU-boost kthread for the specified node if one does not + * already exist. We only create this kthread for preemptible RCU. + * Returns zero if all is well, a negated errno otherwise. + */ +static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp, + struct rcu_node *rnp, + int rnp_index) +{ + unsigned long flags; + struct sched_param sp; + struct task_struct *t; + + if (&rcu_preempt_state != rsp) + return 0; + if (rnp->boost_kthread_task != NULL) + return 0; + t = kthread_create(rcu_boost_kthread, (void *)rnp, + "rcub%d", rnp_index); + if (IS_ERR(t)) + return PTR_ERR(t); + raw_spin_lock_irqsave(&rnp->lock, flags); + rnp->boost_kthread_task = t; + raw_spin_unlock_irqrestore(&rnp->lock, flags); + wake_up_process(t); + sp.sched_priority = RCU_KTHREAD_PRIO; + sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); + return 0; +} + +#else /* #ifdef CONFIG_RCU_BOOST */ + +static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags) +{ + raw_spin_unlock_irqrestore(&rnp->lock, flags); +} + +static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, + cpumask_var_t cm) +{ +} + +static void rcu_preempt_boost_start_gp(struct rcu_node *rnp) +{ +} + +static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp) +{ +} + +static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp, + struct rcu_node *rnp, + int rnp_index) +{ + return 0; +} + +#endif /* #else #ifdef CONFIG_RCU_BOOST */ + #ifndef CONFIG_SMP void synchronize_sched_expedited(void) @@ -1187,8 +1513,8 @@ static DEFINE_PER_CPU(unsigned long, rcu_dyntick_holdoff); * * Because it is not legal to invoke rcu_process_callbacks() with irqs * disabled, we do one pass of force_quiescent_state(), then do a - * raise_softirq() to cause rcu_process_callbacks() to be invoked later. - * The per-cpu rcu_dyntick_drain variable controls the sequencing. + * invoke_rcu_cpu_kthread() to cause rcu_process_callbacks() to be invoked + * later. The per-cpu rcu_dyntick_drain variable controls the sequencing. */ int rcu_needs_cpu(int cpu) { @@ -1239,7 +1565,7 @@ int rcu_needs_cpu(int cpu) /* If RCU callbacks are still pending, RCU still needs this CPU. */ if (c) - raise_softirq(RCU_SOFTIRQ); + invoke_rcu_cpu_kthread(); return c; } diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c index c8e97853b970..aa0fd72b4bc7 100644 --- a/kernel/rcutree_trace.c +++ b/kernel/rcutree_trace.c @@ -46,6 +46,18 @@ #define RCU_TREE_NONCORE #include "rcutree.h" +DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status); +DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_cpu); +DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops); +DECLARE_PER_CPU(char, rcu_cpu_has_work); + +static char convert_kthread_status(unsigned int kthread_status) +{ + if (kthread_status > RCU_KTHREAD_MAX) + return '?'; + return "SRWOY"[kthread_status]; +} + static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp) { if (!rdp->beenonline) @@ -64,7 +76,21 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp) rdp->dynticks_fqs); #endif /* #ifdef CONFIG_NO_HZ */ seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi); - seq_printf(m, " ql=%ld b=%ld", rdp->qlen, rdp->blimit); + seq_printf(m, " ql=%ld qs=%c%c%c%c kt=%d/%c/%d ktl=%x b=%ld", + rdp->qlen, + ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] != + rdp->nxttail[RCU_NEXT_TAIL]], + ".R"[rdp->nxttail[RCU_WAIT_TAIL] != + rdp->nxttail[RCU_NEXT_READY_TAIL]], + ".W"[rdp->nxttail[RCU_DONE_TAIL] != + rdp->nxttail[RCU_WAIT_TAIL]], + ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]], + per_cpu(rcu_cpu_has_work, rdp->cpu), + convert_kthread_status(per_cpu(rcu_cpu_kthread_status, + rdp->cpu)), + per_cpu(rcu_cpu_kthread_cpu, rdp->cpu), + per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff, + rdp->blimit); seq_printf(m, " ci=%lu co=%lu ca=%lu\n", rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted); } @@ -121,7 +147,18 @@ static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp) rdp->dynticks_fqs); #endif /* #ifdef CONFIG_NO_HZ */ seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi); - seq_printf(m, ",%ld,%ld", rdp->qlen, rdp->blimit); + seq_printf(m, ",%ld,\"%c%c%c%c\",%d,\"%c\",%ld", rdp->qlen, + ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] != + rdp->nxttail[RCU_NEXT_TAIL]], + ".R"[rdp->nxttail[RCU_WAIT_TAIL] != + rdp->nxttail[RCU_NEXT_READY_TAIL]], + ".W"[rdp->nxttail[RCU_DONE_TAIL] != + rdp->nxttail[RCU_WAIT_TAIL]], + ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]], + per_cpu(rcu_cpu_has_work, rdp->cpu), + convert_kthread_status(per_cpu(rcu_cpu_kthread_status, + rdp->cpu)), + rdp->blimit); seq_printf(m, ",%lu,%lu,%lu\n", rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted); } @@ -157,11 +194,76 @@ static const struct file_operations rcudata_csv_fops = { .release = single_release, }; +#ifdef CONFIG_RCU_BOOST + +static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp) +{ + seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu " + "j=%04x bt=%04x\n", + rnp->grplo, rnp->grphi, + "T."[list_empty(&rnp->blkd_tasks)], + "N."[!rnp->gp_tasks], + "E."[!rnp->exp_tasks], + "B."[!rnp->boost_tasks], + convert_kthread_status(rnp->boost_kthread_status), + rnp->n_tasks_boosted, rnp->n_exp_boosts, + rnp->n_normal_boosts, + (int)(jiffies & 0xffff), + (int)(rnp->boost_time & 0xffff)); + seq_printf(m, "%s: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n", + " balk", + rnp->n_balk_blkd_tasks, + rnp->n_balk_exp_gp_tasks, + rnp->n_balk_boost_tasks, + rnp->n_balk_notblocked, + rnp->n_balk_notyet, + rnp->n_balk_nos); +} + +static int show_rcu_node_boost(struct seq_file *m, void *unused) +{ + struct rcu_node *rnp; + + rcu_for_each_leaf_node(&rcu_preempt_state, rnp) + print_one_rcu_node_boost(m, rnp); + return 0; +} + +static int rcu_node_boost_open(struct inode *inode, struct file *file) +{ + return single_open(file, show_rcu_node_boost, NULL); +} + +static const struct file_operations rcu_node_boost_fops = { + .owner = THIS_MODULE, + .open = rcu_node_boost_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +/* + * Create the rcuboost debugfs entry. Standard error return. + */ +static int rcu_boost_trace_create_file(struct dentry *rcudir) +{ + return !debugfs_create_file("rcuboost", 0444, rcudir, NULL, + &rcu_node_boost_fops); +} + +#else /* #ifdef CONFIG_RCU_BOOST */ + +static int rcu_boost_trace_create_file(struct dentry *rcudir) +{ + return 0; /* There cannot be an error if we didn't create it! */ +} + +#endif /* #else #ifdef CONFIG_RCU_BOOST */ + static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp) { unsigned long gpnum; int level = 0; - int phase; struct rcu_node *rnp; gpnum = rsp->gpnum; @@ -178,13 +280,11 @@ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp) seq_puts(m, "\n"); level = rnp->level; } - phase = gpnum & 0x1; - seq_printf(m, "%lx/%lx %c%c>%c%c %d:%d ^%d ", + seq_printf(m, "%lx/%lx %c%c>%c %d:%d ^%d ", rnp->qsmask, rnp->qsmaskinit, - "T."[list_empty(&rnp->blocked_tasks[phase])], - "E."[list_empty(&rnp->blocked_tasks[phase + 2])], - "T."[list_empty(&rnp->blocked_tasks[!phase])], - "E."[list_empty(&rnp->blocked_tasks[!phase + 2])], + ".G"[rnp->gp_tasks != NULL], + ".E"[rnp->exp_tasks != NULL], + ".T"[!list_empty(&rnp->blkd_tasks)], rnp->grplo, rnp->grphi, rnp->grpnum); } seq_puts(m, "\n"); @@ -216,16 +316,35 @@ static const struct file_operations rcuhier_fops = { .release = single_release, }; +static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp) +{ + unsigned long flags; + unsigned long completed; + unsigned long gpnum; + unsigned long gpage; + unsigned long gpmax; + struct rcu_node *rnp = &rsp->node[0]; + + raw_spin_lock_irqsave(&rnp->lock, flags); + completed = rsp->completed; + gpnum = rsp->gpnum; + if (rsp->completed == rsp->gpnum) + gpage = 0; + else + gpage = jiffies - rsp->gp_start; + gpmax = rsp->gp_max; + raw_spin_unlock_irqrestore(&rnp->lock, flags); + seq_printf(m, "%s: completed=%ld gpnum=%lu age=%ld max=%ld\n", + rsp->name, completed, gpnum, gpage, gpmax); +} + static int show_rcugp(struct seq_file *m, void *unused) { #ifdef CONFIG_TREE_PREEMPT_RCU - seq_printf(m, "rcu_preempt: completed=%ld gpnum=%lu\n", - rcu_preempt_state.completed, rcu_preempt_state.gpnum); + show_one_rcugp(m, &rcu_preempt_state); #endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */ - seq_printf(m, "rcu_sched: completed=%ld gpnum=%lu\n", - rcu_sched_state.completed, rcu_sched_state.gpnum); - seq_printf(m, "rcu_bh: completed=%ld gpnum=%lu\n", - rcu_bh_state.completed, rcu_bh_state.gpnum); + show_one_rcugp(m, &rcu_sched_state); + show_one_rcugp(m, &rcu_bh_state); return 0; } @@ -298,6 +417,29 @@ static const struct file_operations rcu_pending_fops = { .release = single_release, }; +static int show_rcutorture(struct seq_file *m, void *unused) +{ + seq_printf(m, "rcutorture test sequence: %lu %s\n", + rcutorture_testseq >> 1, + (rcutorture_testseq & 0x1) ? "(test in progress)" : ""); + seq_printf(m, "rcutorture update version number: %lu\n", + rcutorture_vernum); + return 0; +} + +static int rcutorture_open(struct inode *inode, struct file *file) +{ + return single_open(file, show_rcutorture, NULL); +} + +static const struct file_operations rcutorture_fops = { + .owner = THIS_MODULE, + .open = rcutorture_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static struct dentry *rcudir; static int __init rcutree_trace_init(void) @@ -318,6 +460,9 @@ static int __init rcutree_trace_init(void) if (!retval) goto free_out; + if (rcu_boost_trace_create_file(rcudir)) + goto free_out; + retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops); if (!retval) goto free_out; @@ -331,6 +476,11 @@ static int __init rcutree_trace_init(void) NULL, &rcu_pending_fops); if (!retval) goto free_out; + + retval = debugfs_create_file("rcutorture", 0444, rcudir, + NULL, &rcutorture_fops); + if (!retval) + goto free_out; return 0; free_out: debugfs_remove_recursive(rcudir); diff --git a/kernel/sched.c b/kernel/sched.c index 312f8b95c2d4..c62acf45d3b9 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -231,7 +231,7 @@ static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) #endif /* - * sched_domains_mutex serializes calls to arch_init_sched_domains, + * sched_domains_mutex serializes calls to init_sched_domains, * detach_destroy_domains and partition_sched_domains. */ static DEFINE_MUTEX(sched_domains_mutex); @@ -312,6 +312,9 @@ struct cfs_rq { u64 exec_clock; u64 min_vruntime; +#ifndef CONFIG_64BIT + u64 min_vruntime_copy; +#endif struct rb_root tasks_timeline; struct rb_node *rb_leftmost; @@ -325,7 +328,9 @@ struct cfs_rq { */ struct sched_entity *curr, *next, *last, *skip; +#ifdef CONFIG_SCHED_DEBUG unsigned int nr_spread_over; +#endif #ifdef CONFIG_FAIR_GROUP_SCHED struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ @@ -417,6 +422,7 @@ struct rt_rq { */ struct root_domain { atomic_t refcount; + struct rcu_head rcu; cpumask_var_t span; cpumask_var_t online; @@ -460,7 +466,7 @@ struct rq { u64 nohz_stamp; unsigned char nohz_balance_kick; #endif - unsigned int skip_clock_update; + int skip_clock_update; /* capture load from *all* tasks on this cpu: */ struct load_weight load; @@ -553,6 +559,10 @@ struct rq { unsigned int ttwu_count; unsigned int ttwu_local; #endif + +#ifdef CONFIG_SMP + struct task_struct *wake_list; +#endif }; static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); @@ -571,7 +581,7 @@ static inline int cpu_of(struct rq *rq) #define rcu_dereference_check_sched_domain(p) \ rcu_dereference_check((p), \ - rcu_read_lock_sched_held() || \ + rcu_read_lock_held() || \ lockdep_is_held(&sched_domains_mutex)) /* @@ -596,7 +606,7 @@ static inline int cpu_of(struct rq *rq) * Return the group to which this tasks belongs. * * We use task_subsys_state_check() and extend the RCU verification - * with lockdep_is_held(&task_rq(p)->lock) because cpu_cgroup_attach() + * with lockdep_is_held(&p->pi_lock) because cpu_cgroup_attach() * holds that lock for each task it moves into the cgroup. Therefore * by holding that lock, we pin the task to the current cgroup. */ @@ -606,7 +616,7 @@ static inline struct task_group *task_group(struct task_struct *p) struct cgroup_subsys_state *css; css = task_subsys_state_check(p, cpu_cgroup_subsys_id, - lockdep_is_held(&task_rq(p)->lock)); + lockdep_is_held(&p->pi_lock)); tg = container_of(css, struct task_group, css); return autogroup_task_group(p, tg); @@ -642,7 +652,7 @@ static void update_rq_clock(struct rq *rq) { s64 delta; - if (rq->skip_clock_update) + if (rq->skip_clock_update > 0) return; delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; @@ -838,18 +848,39 @@ static inline int task_current(struct rq *rq, struct task_struct *p) return rq->curr == p; } -#ifndef __ARCH_WANT_UNLOCKED_CTXSW static inline int task_running(struct rq *rq, struct task_struct *p) { +#ifdef CONFIG_SMP + return p->on_cpu; +#else return task_current(rq, p); +#endif } +#ifndef __ARCH_WANT_UNLOCKED_CTXSW static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) { +#ifdef CONFIG_SMP + /* + * We can optimise this out completely for !SMP, because the + * SMP rebalancing from interrupt is the only thing that cares + * here. + */ + next->on_cpu = 1; +#endif } static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) { +#ifdef CONFIG_SMP + /* + * After ->on_cpu is cleared, the task can be moved to a different CPU. + * We must ensure this doesn't happen until the switch is completely + * finished. + */ + smp_wmb(); + prev->on_cpu = 0; +#endif #ifdef CONFIG_DEBUG_SPINLOCK /* this is a valid case when another task releases the spinlock */ rq->lock.owner = current; @@ -865,15 +896,6 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) } #else /* __ARCH_WANT_UNLOCKED_CTXSW */ -static inline int task_running(struct rq *rq, struct task_struct *p) -{ -#ifdef CONFIG_SMP - return p->oncpu; -#else - return task_current(rq, p); -#endif -} - static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) { #ifdef CONFIG_SMP @@ -882,7 +904,7 @@ static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) * SMP rebalancing from interrupt is the only thing that cares * here. */ - next->oncpu = 1; + next->on_cpu = 1; #endif #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW raw_spin_unlock_irq(&rq->lock); @@ -895,12 +917,12 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) { #ifdef CONFIG_SMP /* - * After ->oncpu is cleared, the task can be moved to a different CPU. + * After ->on_cpu is cleared, the task can be moved to a different CPU. * We must ensure this doesn't happen until the switch is completely * finished. */ smp_wmb(); - prev->oncpu = 0; + prev->on_cpu = 0; #endif #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW local_irq_enable(); @@ -909,23 +931,15 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ /* - * Check whether the task is waking, we use this to synchronize ->cpus_allowed - * against ttwu(). - */ -static inline int task_is_waking(struct task_struct *p) -{ - return unlikely(p->state == TASK_WAKING); -} - -/* - * __task_rq_lock - lock the runqueue a given task resides on. - * Must be called interrupts disabled. + * __task_rq_lock - lock the rq @p resides on. */ static inline struct rq *__task_rq_lock(struct task_struct *p) __acquires(rq->lock) { struct rq *rq; + lockdep_assert_held(&p->pi_lock); + for (;;) { rq = task_rq(p); raw_spin_lock(&rq->lock); @@ -936,22 +950,22 @@ static inline struct rq *__task_rq_lock(struct task_struct *p) } /* - * task_rq_lock - lock the runqueue a given task resides on and disable - * interrupts. Note the ordering: we can safely lookup the task_rq without - * explicitly disabling preemption. + * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. */ static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) + __acquires(p->pi_lock) __acquires(rq->lock) { struct rq *rq; for (;;) { - local_irq_save(*flags); + raw_spin_lock_irqsave(&p->pi_lock, *flags); rq = task_rq(p); raw_spin_lock(&rq->lock); if (likely(rq == task_rq(p))) return rq; - raw_spin_unlock_irqrestore(&rq->lock, *flags); + raw_spin_unlock(&rq->lock); + raw_spin_unlock_irqrestore(&p->pi_lock, *flags); } } @@ -961,10 +975,13 @@ static void __task_rq_unlock(struct rq *rq) raw_spin_unlock(&rq->lock); } -static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) +static inline void +task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) __releases(rq->lock) + __releases(p->pi_lock) { - raw_spin_unlock_irqrestore(&rq->lock, *flags); + raw_spin_unlock(&rq->lock); + raw_spin_unlock_irqrestore(&p->pi_lock, *flags); } /* @@ -1193,11 +1210,17 @@ int get_nohz_timer_target(void) int i; struct sched_domain *sd; + rcu_read_lock(); for_each_domain(cpu, sd) { - for_each_cpu(i, sched_domain_span(sd)) - if (!idle_cpu(i)) - return i; + for_each_cpu(i, sched_domain_span(sd)) { + if (!idle_cpu(i)) { + cpu = i; + goto unlock; + } + } } +unlock: + rcu_read_unlock(); return cpu; } /* @@ -1307,15 +1330,15 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight, { u64 tmp; + tmp = (u64)delta_exec * weight; + if (!lw->inv_weight) { if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) lw->inv_weight = 1; else - lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) - / (lw->weight+1); + lw->inv_weight = WMULT_CONST / lw->weight; } - tmp = (u64)delta_exec * weight; /* * Check whether we'd overflow the 64-bit multiplication: */ @@ -1773,7 +1796,6 @@ static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) update_rq_clock(rq); sched_info_queued(p); p->sched_class->enqueue_task(rq, p, flags); - p->se.on_rq = 1; } static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) @@ -1781,7 +1803,6 @@ static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) update_rq_clock(rq); sched_info_dequeued(p); p->sched_class->dequeue_task(rq, p, flags); - p->se.on_rq = 0; } /* @@ -2116,7 +2137,7 @@ static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) * A queue event has occurred, and we're going to schedule. In * this case, we can save a useless back to back clock update. */ - if (rq->curr->se.on_rq && test_tsk_need_resched(rq->curr)) + if (rq->curr->on_rq && test_tsk_need_resched(rq->curr)) rq->skip_clock_update = 1; } @@ -2162,6 +2183,11 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) */ WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); + +#ifdef CONFIG_LOCKDEP + WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || + lockdep_is_held(&task_rq(p)->lock))); +#endif #endif trace_sched_migrate_task(p, new_cpu); @@ -2182,19 +2208,6 @@ struct migration_arg { static int migration_cpu_stop(void *data); /* - * The task's runqueue lock must be held. - * Returns true if you have to wait for migration thread. - */ -static bool migrate_task(struct task_struct *p, struct rq *rq) -{ - /* - * If the task is not on a runqueue (and not running), then - * the next wake-up will properly place the task. - */ - return p->se.on_rq || task_running(rq, p); -} - -/* * wait_task_inactive - wait for a thread to unschedule. * * If @match_state is nonzero, it's the @p->state value just checked and @@ -2251,11 +2264,11 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state) rq = task_rq_lock(p, &flags); trace_sched_wait_task(p); running = task_running(rq, p); - on_rq = p->se.on_rq; + on_rq = p->on_rq; ncsw = 0; if (!match_state || p->state == match_state) ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ - task_rq_unlock(rq, &flags); + task_rq_unlock(rq, p, &flags); /* * If it changed from the expected state, bail out now. @@ -2330,7 +2343,7 @@ EXPORT_SYMBOL_GPL(kick_process); #ifdef CONFIG_SMP /* - * ->cpus_allowed is protected by either TASK_WAKING or rq->lock held. + * ->cpus_allowed is protected by both rq->lock and p->pi_lock */ static int select_fallback_rq(int cpu, struct task_struct *p) { @@ -2363,12 +2376,12 @@ static int select_fallback_rq(int cpu, struct task_struct *p) } /* - * The caller (fork, wakeup) owns TASK_WAKING, ->cpus_allowed is stable. + * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. */ static inline -int select_task_rq(struct rq *rq, struct task_struct *p, int sd_flags, int wake_flags) +int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) { - int cpu = p->sched_class->select_task_rq(rq, p, sd_flags, wake_flags); + int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); /* * In order not to call set_task_cpu() on a blocking task we need @@ -2394,27 +2407,62 @@ static void update_avg(u64 *avg, u64 sample) } #endif -static inline void ttwu_activate(struct task_struct *p, struct rq *rq, - bool is_sync, bool is_migrate, bool is_local, - unsigned long en_flags) +static void +ttwu_stat(struct task_struct *p, int cpu, int wake_flags) { +#ifdef CONFIG_SCHEDSTATS + struct rq *rq = this_rq(); + +#ifdef CONFIG_SMP + int this_cpu = smp_processor_id(); + + if (cpu == this_cpu) { + schedstat_inc(rq, ttwu_local); + schedstat_inc(p, se.statistics.nr_wakeups_local); + } else { + struct sched_domain *sd; + + schedstat_inc(p, se.statistics.nr_wakeups_remote); + rcu_read_lock(); + for_each_domain(this_cpu, sd) { + if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { + schedstat_inc(sd, ttwu_wake_remote); + break; + } + } + rcu_read_unlock(); + } +#endif /* CONFIG_SMP */ + + schedstat_inc(rq, ttwu_count); schedstat_inc(p, se.statistics.nr_wakeups); - if (is_sync) + + if (wake_flags & WF_SYNC) schedstat_inc(p, se.statistics.nr_wakeups_sync); - if (is_migrate) + + if (cpu != task_cpu(p)) schedstat_inc(p, se.statistics.nr_wakeups_migrate); - if (is_local) - schedstat_inc(p, se.statistics.nr_wakeups_local); - else - schedstat_inc(p, se.statistics.nr_wakeups_remote); +#endif /* CONFIG_SCHEDSTATS */ +} + +static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) +{ activate_task(rq, p, en_flags); + p->on_rq = 1; + + /* if a worker is waking up, notify workqueue */ + if (p->flags & PF_WQ_WORKER) + wq_worker_waking_up(p, cpu_of(rq)); } -static inline void ttwu_post_activation(struct task_struct *p, struct rq *rq, - int wake_flags, bool success) +/* + * Mark the task runnable and perform wakeup-preemption. + */ +static void +ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) { - trace_sched_wakeup(p, success); + trace_sched_wakeup(p, true); check_preempt_curr(rq, p, wake_flags); p->state = TASK_RUNNING; @@ -2433,9 +2481,99 @@ static inline void ttwu_post_activation(struct task_struct *p, struct rq *rq, rq->idle_stamp = 0; } #endif - /* if a worker is waking up, notify workqueue */ - if ((p->flags & PF_WQ_WORKER) && success) - wq_worker_waking_up(p, cpu_of(rq)); +} + +static void +ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) +{ +#ifdef CONFIG_SMP + if (p->sched_contributes_to_load) + rq->nr_uninterruptible--; +#endif + + ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING); + ttwu_do_wakeup(rq, p, wake_flags); +} + +/* + * Called in case the task @p isn't fully descheduled from its runqueue, + * in this case we must do a remote wakeup. Its a 'light' wakeup though, + * since all we need to do is flip p->state to TASK_RUNNING, since + * the task is still ->on_rq. + */ +static int ttwu_remote(struct task_struct *p, int wake_flags) +{ + struct rq *rq; + int ret = 0; + + rq = __task_rq_lock(p); + if (p->on_rq) { + ttwu_do_wakeup(rq, p, wake_flags); + ret = 1; + } + __task_rq_unlock(rq); + + return ret; +} + +#ifdef CONFIG_SMP +static void sched_ttwu_pending(void) +{ + struct rq *rq = this_rq(); + struct task_struct *list = xchg(&rq->wake_list, NULL); + + if (!list) + return; + + raw_spin_lock(&rq->lock); + + while (list) { + struct task_struct *p = list; + list = list->wake_entry; + ttwu_do_activate(rq, p, 0); + } + + raw_spin_unlock(&rq->lock); +} + +void scheduler_ipi(void) +{ + sched_ttwu_pending(); +} + +static void ttwu_queue_remote(struct task_struct *p, int cpu) +{ + struct rq *rq = cpu_rq(cpu); + struct task_struct *next = rq->wake_list; + + for (;;) { + struct task_struct *old = next; + + p->wake_entry = next; + next = cmpxchg(&rq->wake_list, old, p); + if (next == old) + break; + } + + if (!next) + smp_send_reschedule(cpu); +} +#endif + +static void ttwu_queue(struct task_struct *p, int cpu) +{ + struct rq *rq = cpu_rq(cpu); + +#if defined(CONFIG_SMP) && defined(CONFIG_SCHED_TTWU_QUEUE) + if (sched_feat(TTWU_QUEUE) && cpu != smp_processor_id()) { + ttwu_queue_remote(p, cpu); + return; + } +#endif + + raw_spin_lock(&rq->lock); + ttwu_do_activate(rq, p, 0); + raw_spin_unlock(&rq->lock); } /** @@ -2453,92 +2591,64 @@ static inline void ttwu_post_activation(struct task_struct *p, struct rq *rq, * Returns %true if @p was woken up, %false if it was already running * or @state didn't match @p's state. */ -static int try_to_wake_up(struct task_struct *p, unsigned int state, - int wake_flags) +static int +try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) { - int cpu, orig_cpu, this_cpu, success = 0; unsigned long flags; - unsigned long en_flags = ENQUEUE_WAKEUP; - struct rq *rq; - - this_cpu = get_cpu(); + int cpu, success = 0; smp_wmb(); - rq = task_rq_lock(p, &flags); + raw_spin_lock_irqsave(&p->pi_lock, flags); if (!(p->state & state)) goto out; - if (p->se.on_rq) - goto out_running; - + success = 1; /* we're going to change ->state */ cpu = task_cpu(p); - orig_cpu = cpu; -#ifdef CONFIG_SMP - if (unlikely(task_running(rq, p))) - goto out_activate; + if (p->on_rq && ttwu_remote(p, wake_flags)) + goto stat; +#ifdef CONFIG_SMP /* - * In order to handle concurrent wakeups and release the rq->lock - * we put the task in TASK_WAKING state. - * - * First fix up the nr_uninterruptible count: + * If the owning (remote) cpu is still in the middle of schedule() with + * this task as prev, wait until its done referencing the task. */ - if (task_contributes_to_load(p)) { - if (likely(cpu_online(orig_cpu))) - rq->nr_uninterruptible--; - else - this_rq()->nr_uninterruptible--; - } - p->state = TASK_WAKING; - - if (p->sched_class->task_waking) { - p->sched_class->task_waking(rq, p); - en_flags |= ENQUEUE_WAKING; + while (p->on_cpu) { +#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW + /* + * If called from interrupt context we could have landed in the + * middle of schedule(), in this case we should take care not + * to spin on ->on_cpu if p is current, since that would + * deadlock. + */ + if (p == current) { + ttwu_queue(p, cpu); + goto stat; + } +#endif + cpu_relax(); } - - cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags); - if (cpu != orig_cpu) - set_task_cpu(p, cpu); - __task_rq_unlock(rq); - - rq = cpu_rq(cpu); - raw_spin_lock(&rq->lock); - /* - * We migrated the task without holding either rq->lock, however - * since the task is not on the task list itself, nobody else - * will try and migrate the task, hence the rq should match the - * cpu we just moved it to. + * Pairs with the smp_wmb() in finish_lock_switch(). */ - WARN_ON(task_cpu(p) != cpu); - WARN_ON(p->state != TASK_WAKING); + smp_rmb(); -#ifdef CONFIG_SCHEDSTATS - schedstat_inc(rq, ttwu_count); - if (cpu == this_cpu) - schedstat_inc(rq, ttwu_local); - else { - struct sched_domain *sd; - for_each_domain(this_cpu, sd) { - if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { - schedstat_inc(sd, ttwu_wake_remote); - break; - } - } - } -#endif /* CONFIG_SCHEDSTATS */ + p->sched_contributes_to_load = !!task_contributes_to_load(p); + p->state = TASK_WAKING; + + if (p->sched_class->task_waking) + p->sched_class->task_waking(p); -out_activate: + cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); + if (task_cpu(p) != cpu) + set_task_cpu(p, cpu); #endif /* CONFIG_SMP */ - ttwu_activate(p, rq, wake_flags & WF_SYNC, orig_cpu != cpu, - cpu == this_cpu, en_flags); - success = 1; -out_running: - ttwu_post_activation(p, rq, wake_flags, success); + + ttwu_queue(p, cpu); +stat: + ttwu_stat(p, cpu, wake_flags); out: - task_rq_unlock(rq, &flags); - put_cpu(); + raw_spin_unlock_irqrestore(&p->pi_lock, flags); return success; } @@ -2547,31 +2657,34 @@ out: * try_to_wake_up_local - try to wake up a local task with rq lock held * @p: the thread to be awakened * - * Put @p on the run-queue if it's not already there. The caller must + * Put @p on the run-queue if it's not already there. The caller must * ensure that this_rq() is locked, @p is bound to this_rq() and not - * the current task. this_rq() stays locked over invocation. + * the current task. */ static void try_to_wake_up_local(struct task_struct *p) { struct rq *rq = task_rq(p); - bool success = false; BUG_ON(rq != this_rq()); BUG_ON(p == current); lockdep_assert_held(&rq->lock); + if (!raw_spin_trylock(&p->pi_lock)) { + raw_spin_unlock(&rq->lock); + raw_spin_lock(&p->pi_lock); + raw_spin_lock(&rq->lock); + } + if (!(p->state & TASK_NORMAL)) - return; + goto out; - if (!p->se.on_rq) { - if (likely(!task_running(rq, p))) { - schedstat_inc(rq, ttwu_count); - schedstat_inc(rq, ttwu_local); - } - ttwu_activate(p, rq, false, false, true, ENQUEUE_WAKEUP); - success = true; - } - ttwu_post_activation(p, rq, 0, success); + if (!p->on_rq) + ttwu_activate(rq, p, ENQUEUE_WAKEUP); + + ttwu_do_wakeup(rq, p, 0); + ttwu_stat(p, smp_processor_id(), 0); +out: + raw_spin_unlock(&p->pi_lock); } /** @@ -2604,19 +2717,21 @@ int wake_up_state(struct task_struct *p, unsigned int state) */ static void __sched_fork(struct task_struct *p) { + p->on_rq = 0; + + p->se.on_rq = 0; p->se.exec_start = 0; p->se.sum_exec_runtime = 0; p->se.prev_sum_exec_runtime = 0; p->se.nr_migrations = 0; p->se.vruntime = 0; + INIT_LIST_HEAD(&p->se.group_node); #ifdef CONFIG_SCHEDSTATS memset(&p->se.statistics, 0, sizeof(p->se.statistics)); #endif INIT_LIST_HEAD(&p->rt.run_list); - p->se.on_rq = 0; - INIT_LIST_HEAD(&p->se.group_node); #ifdef CONFIG_PREEMPT_NOTIFIERS INIT_HLIST_HEAD(&p->preempt_notifiers); @@ -2626,8 +2741,9 @@ static void __sched_fork(struct task_struct *p) /* * fork()/clone()-time setup: */ -void sched_fork(struct task_struct *p, int clone_flags) +void sched_fork(struct task_struct *p) { + unsigned long flags; int cpu = get_cpu(); __sched_fork(p); @@ -2678,16 +2794,16 @@ void sched_fork(struct task_struct *p, int clone_flags) * * Silence PROVE_RCU. */ - rcu_read_lock(); + raw_spin_lock_irqsave(&p->pi_lock, flags); set_task_cpu(p, cpu); - rcu_read_unlock(); + raw_spin_unlock_irqrestore(&p->pi_lock, flags); #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) if (likely(sched_info_on())) memset(&p->sched_info, 0, sizeof(p->sched_info)); #endif -#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) - p->oncpu = 0; +#if defined(CONFIG_SMP) + p->on_cpu = 0; #endif #ifdef CONFIG_PREEMPT /* Want to start with kernel preemption disabled. */ @@ -2707,41 +2823,31 @@ void sched_fork(struct task_struct *p, int clone_flags) * that must be done for every newly created context, then puts the task * on the runqueue and wakes it. */ -void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) +void wake_up_new_task(struct task_struct *p) { unsigned long flags; struct rq *rq; - int cpu __maybe_unused = get_cpu(); + raw_spin_lock_irqsave(&p->pi_lock, flags); #ifdef CONFIG_SMP - rq = task_rq_lock(p, &flags); - p->state = TASK_WAKING; - /* * Fork balancing, do it here and not earlier because: * - cpus_allowed can change in the fork path * - any previously selected cpu might disappear through hotplug - * - * We set TASK_WAKING so that select_task_rq() can drop rq->lock - * without people poking at ->cpus_allowed. */ - cpu = select_task_rq(rq, p, SD_BALANCE_FORK, 0); - set_task_cpu(p, cpu); - - p->state = TASK_RUNNING; - task_rq_unlock(rq, &flags); + set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0)); #endif - rq = task_rq_lock(p, &flags); + rq = __task_rq_lock(p); activate_task(rq, p, 0); - trace_sched_wakeup_new(p, 1); + p->on_rq = 1; + trace_sched_wakeup_new(p, true); check_preempt_curr(rq, p, WF_FORK); #ifdef CONFIG_SMP if (p->sched_class->task_woken) p->sched_class->task_woken(rq, p); #endif - task_rq_unlock(rq, &flags); - put_cpu(); + task_rq_unlock(rq, p, &flags); } #ifdef CONFIG_PREEMPT_NOTIFIERS @@ -3450,27 +3556,22 @@ void sched_exec(void) { struct task_struct *p = current; unsigned long flags; - struct rq *rq; int dest_cpu; - rq = task_rq_lock(p, &flags); - dest_cpu = p->sched_class->select_task_rq(rq, p, SD_BALANCE_EXEC, 0); + raw_spin_lock_irqsave(&p->pi_lock, flags); + dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0); if (dest_cpu == smp_processor_id()) goto unlock; - /* - * select_task_rq() can race against ->cpus_allowed - */ - if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed) && - likely(cpu_active(dest_cpu)) && migrate_task(p, rq)) { + if (likely(cpu_active(dest_cpu))) { struct migration_arg arg = { p, dest_cpu }; - task_rq_unlock(rq, &flags); - stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); + raw_spin_unlock_irqrestore(&p->pi_lock, flags); + stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); return; } unlock: - task_rq_unlock(rq, &flags); + raw_spin_unlock_irqrestore(&p->pi_lock, flags); } #endif @@ -3507,7 +3608,7 @@ unsigned long long task_delta_exec(struct task_struct *p) rq = task_rq_lock(p, &flags); ns = do_task_delta_exec(p, rq); - task_rq_unlock(rq, &flags); + task_rq_unlock(rq, p, &flags); return ns; } @@ -3525,7 +3626,7 @@ unsigned long long task_sched_runtime(struct task_struct *p) rq = task_rq_lock(p, &flags); ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); - task_rq_unlock(rq, &flags); + task_rq_unlock(rq, p, &flags); return ns; } @@ -3549,7 +3650,7 @@ unsigned long long thread_group_sched_runtime(struct task_struct *p) rq = task_rq_lock(p, &flags); thread_group_cputime(p, &totals); ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); - task_rq_unlock(rq, &flags); + task_rq_unlock(rq, p, &flags); return ns; } @@ -3903,9 +4004,6 @@ void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) /* * This function gets called by the timer code, with HZ frequency. * We call it with interrupts disabled. - * - * It also gets called by the fork code, when changing the parent's - * timeslices. */ void scheduler_tick(void) { @@ -4025,17 +4123,11 @@ static inline void schedule_debug(struct task_struct *prev) profile_hit(SCHED_PROFILING, __builtin_return_address(0)); schedstat_inc(this_rq(), sched_count); -#ifdef CONFIG_SCHEDSTATS - if (unlikely(prev->lock_depth >= 0)) { - schedstat_inc(this_rq(), rq_sched_info.bkl_count); - schedstat_inc(prev, sched_info.bkl_count); - } -#endif } static void put_prev_task(struct rq *rq, struct task_struct *prev) { - if (prev->se.on_rq) + if (prev->on_rq || rq->skip_clock_update < 0) update_rq_clock(rq); prev->sched_class->put_prev_task(rq, prev); } @@ -4097,11 +4189,13 @@ need_resched: if (unlikely(signal_pending_state(prev->state, prev))) { prev->state = TASK_RUNNING; } else { + deactivate_task(rq, prev, DEQUEUE_SLEEP); + prev->on_rq = 0; + /* - * If a worker is going to sleep, notify and - * ask workqueue whether it wants to wake up a - * task to maintain concurrency. If so, wake - * up the task. + * If a worker went to sleep, notify and ask workqueue + * whether it wants to wake up a task to maintain + * concurrency. */ if (prev->flags & PF_WQ_WORKER) { struct task_struct *to_wakeup; @@ -4110,11 +4204,10 @@ need_resched: if (to_wakeup) try_to_wake_up_local(to_wakeup); } - deactivate_task(rq, prev, DEQUEUE_SLEEP); /* - * If we are going to sleep and we have plugged IO queued, make - * sure to submit it to avoid deadlocks. + * If we are going to sleep and we have plugged IO + * queued, make sure to submit it to avoid deadlocks. */ if (blk_needs_flush_plug(prev)) { raw_spin_unlock(&rq->lock); @@ -4161,70 +4254,53 @@ need_resched: EXPORT_SYMBOL(schedule); #ifdef CONFIG_MUTEX_SPIN_ON_OWNER -/* - * Look out! "owner" is an entirely speculative pointer - * access and not reliable. - */ -int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) -{ - unsigned int cpu; - struct rq *rq; - if (!sched_feat(OWNER_SPIN)) - return 0; +static inline bool owner_running(struct mutex *lock, struct task_struct *owner) +{ + bool ret = false; -#ifdef CONFIG_DEBUG_PAGEALLOC - /* - * Need to access the cpu field knowing that - * DEBUG_PAGEALLOC could have unmapped it if - * the mutex owner just released it and exited. - */ - if (probe_kernel_address(&owner->cpu, cpu)) - return 0; -#else - cpu = owner->cpu; -#endif + rcu_read_lock(); + if (lock->owner != owner) + goto fail; /* - * Even if the access succeeded (likely case), - * the cpu field may no longer be valid. + * 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. */ - if (cpu >= nr_cpumask_bits) - return 0; + barrier(); - /* - * We need to validate that we can do a - * get_cpu() and that we have the percpu area. - */ - if (!cpu_online(cpu)) - return 0; + ret = owner->on_cpu; +fail: + rcu_read_unlock(); - rq = cpu_rq(cpu); + return ret; +} - for (;;) { - /* - * Owner changed, break to re-assess state. - */ - if (lock->owner != owner) { - /* - * If the lock has switched to a different owner, - * we likely have heavy contention. Return 0 to quit - * optimistic spinning and not contend further: - */ - if (lock->owner) - return 0; - break; - } +/* + * 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; - /* - * Is that owner really running on that cpu? - */ - if (task_thread_info(rq->curr) != owner || need_resched()) + while (owner_running(lock, owner)) { + if (need_resched()) return 0; arch_mutex_cpu_relax(); } + /* + * If the owner changed to another task there is likely + * heavy contention, stop spinning. + */ + if (lock->owner) + return 0; + return 1; } #endif @@ -4684,19 +4760,18 @@ EXPORT_SYMBOL(sleep_on_timeout); */ void rt_mutex_setprio(struct task_struct *p, int prio) { - unsigned long flags; int oldprio, on_rq, running; struct rq *rq; const struct sched_class *prev_class; BUG_ON(prio < 0 || prio > MAX_PRIO); - rq = task_rq_lock(p, &flags); + rq = __task_rq_lock(p); trace_sched_pi_setprio(p, prio); oldprio = p->prio; prev_class = p->sched_class; - on_rq = p->se.on_rq; + on_rq = p->on_rq; running = task_current(rq, p); if (on_rq) dequeue_task(rq, p, 0); @@ -4716,7 +4791,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio) enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0); check_class_changed(rq, p, prev_class, oldprio); - task_rq_unlock(rq, &flags); + __task_rq_unlock(rq); } #endif @@ -4744,7 +4819,7 @@ void set_user_nice(struct task_struct *p, long nice) p->static_prio = NICE_TO_PRIO(nice); goto out_unlock; } - on_rq = p->se.on_rq; + on_rq = p->on_rq; if (on_rq) dequeue_task(rq, p, 0); @@ -4764,7 +4839,7 @@ void set_user_nice(struct task_struct *p, long nice) resched_task(rq->curr); } out_unlock: - task_rq_unlock(rq, &flags); + task_rq_unlock(rq, p, &flags); } EXPORT_SYMBOL(set_user_nice); @@ -4878,8 +4953,6 @@ static struct task_struct *find_process_by_pid(pid_t pid) static void __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) { - BUG_ON(p->se.on_rq); - p->policy = policy; p->rt_priority = prio; p->normal_prio = normal_prio(p); @@ -4994,20 +5067,17 @@ recheck: /* * make sure no PI-waiters arrive (or leave) while we are * changing the priority of the task: - */ - raw_spin_lock_irqsave(&p->pi_lock, flags); - /* + * * To be able to change p->policy safely, the appropriate * runqueue lock must be held. */ - rq = __task_rq_lock(p); + rq = task_rq_lock(p, &flags); /* * Changing the policy of the stop threads its a very bad idea */ if (p == rq->stop) { - __task_rq_unlock(rq); - raw_spin_unlock_irqrestore(&p->pi_lock, flags); + task_rq_unlock(rq, p, &flags); return -EINVAL; } @@ -5031,8 +5101,7 @@ recheck: if (rt_bandwidth_enabled() && rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime == 0 && !task_group_is_autogroup(task_group(p))) { - __task_rq_unlock(rq); - raw_spin_unlock_irqrestore(&p->pi_lock, flags); + task_rq_unlock(rq, p, &flags); return -EPERM; } } @@ -5041,11 +5110,10 @@ recheck: /* recheck policy now with rq lock held */ if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { policy = oldpolicy = -1; - __task_rq_unlock(rq); - raw_spin_unlock_irqrestore(&p->pi_lock, flags); + task_rq_unlock(rq, p, &flags); goto recheck; } - on_rq = p->se.on_rq; + on_rq = p->on_rq; running = task_current(rq, p); if (on_rq) deactivate_task(rq, p, 0); @@ -5064,8 +5132,7 @@ recheck: activate_task(rq, p, 0); check_class_changed(rq, p, prev_class, oldprio); - __task_rq_unlock(rq); - raw_spin_unlock_irqrestore(&p->pi_lock, flags); + task_rq_unlock(rq, p, &flags); rt_mutex_adjust_pi(p); @@ -5316,7 +5383,6 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask) { struct task_struct *p; unsigned long flags; - struct rq *rq; int retval; get_online_cpus(); @@ -5331,9 +5397,9 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask) if (retval) goto out_unlock; - rq = task_rq_lock(p, &flags); + raw_spin_lock_irqsave(&p->pi_lock, flags); cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); - task_rq_unlock(rq, &flags); + raw_spin_unlock_irqrestore(&p->pi_lock, flags); out_unlock: rcu_read_unlock(); @@ -5658,7 +5724,7 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, rq = task_rq_lock(p, &flags); time_slice = p->sched_class->get_rr_interval(rq, p); - task_rq_unlock(rq, &flags); + task_rq_unlock(rq, p, &flags); rcu_read_unlock(); jiffies_to_timespec(time_slice, &t); @@ -5776,17 +5842,14 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu) rcu_read_unlock(); rq->curr = rq->idle = idle; -#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) - idle->oncpu = 1; +#if defined(CONFIG_SMP) + idle->on_cpu = 1; #endif raw_spin_unlock_irqrestore(&rq->lock, flags); /* Set the preempt count _outside_ the spinlocks! */ -#if defined(CONFIG_PREEMPT) - task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); -#else task_thread_info(idle)->preempt_count = 0; -#endif + /* * The idle tasks have their own, simple scheduling class: */ @@ -5881,26 +5944,17 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) unsigned int dest_cpu; int ret = 0; - /* - * Serialize against TASK_WAKING so that ttwu() and wunt() can - * drop the rq->lock and still rely on ->cpus_allowed. - */ -again: - while (task_is_waking(p)) - cpu_relax(); rq = task_rq_lock(p, &flags); - if (task_is_waking(p)) { - task_rq_unlock(rq, &flags); - goto again; - } + + if (cpumask_equal(&p->cpus_allowed, new_mask)) + goto out; if (!cpumask_intersects(new_mask, cpu_active_mask)) { ret = -EINVAL; goto out; } - if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && - !cpumask_equal(&p->cpus_allowed, new_mask))) { + if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) { ret = -EINVAL; goto out; } @@ -5917,16 +5971,16 @@ again: goto out; dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); - if (migrate_task(p, rq)) { + if (p->on_rq) { struct migration_arg arg = { p, dest_cpu }; /* Need help from migration thread: drop lock and wait. */ - task_rq_unlock(rq, &flags); + task_rq_unlock(rq, p, &flags); stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); tlb_migrate_finish(p->mm); return 0; } out: - task_rq_unlock(rq, &flags); + task_rq_unlock(rq, p, &flags); return ret; } @@ -5954,6 +6008,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) rq_src = cpu_rq(src_cpu); rq_dest = cpu_rq(dest_cpu); + raw_spin_lock(&p->pi_lock); double_rq_lock(rq_src, rq_dest); /* Already moved. */ if (task_cpu(p) != src_cpu) @@ -5966,7 +6021,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) * If we're not on a rq, the next wake-up will ensure we're * placed properly. */ - if (p->se.on_rq) { + if (p->on_rq) { deactivate_task(rq_src, p, 0); set_task_cpu(p, dest_cpu); activate_task(rq_dest, p, 0); @@ -5976,6 +6031,7 @@ done: ret = 1; fail: double_rq_unlock(rq_src, rq_dest); + raw_spin_unlock(&p->pi_lock); return ret; } @@ -6316,6 +6372,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) #ifdef CONFIG_HOTPLUG_CPU case CPU_DYING: + sched_ttwu_pending(); /* Update our root-domain */ raw_spin_lock_irqsave(&rq->lock, flags); if (rq->rd) { @@ -6394,6 +6451,8 @@ early_initcall(migration_init); #ifdef CONFIG_SMP +static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */ + #ifdef CONFIG_SCHED_DEBUG static __read_mostly int sched_domain_debug_enabled; @@ -6489,7 +6548,6 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, static void sched_domain_debug(struct sched_domain *sd, int cpu) { - cpumask_var_t groupmask; int level = 0; if (!sched_domain_debug_enabled) @@ -6502,20 +6560,14 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu) printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); - if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { - printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); - return; - } - for (;;) { - if (sched_domain_debug_one(sd, cpu, level, groupmask)) + if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) break; level++; sd = sd->parent; if (!sd) break; } - free_cpumask_var(groupmask); } #else /* !CONFIG_SCHED_DEBUG */ # define sched_domain_debug(sd, cpu) do { } while (0) @@ -6572,12 +6624,11 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) return 1; } -static void free_rootdomain(struct root_domain *rd) +static void free_rootdomain(struct rcu_head *rcu) { - synchronize_sched(); + struct root_domain *rd = container_of(rcu, struct root_domain, rcu); cpupri_cleanup(&rd->cpupri); - free_cpumask_var(rd->rto_mask); free_cpumask_var(rd->online); free_cpumask_var(rd->span); @@ -6618,7 +6669,7 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd) raw_spin_unlock_irqrestore(&rq->lock, flags); if (old_rd) - free_rootdomain(old_rd); + call_rcu_sched(&old_rd->rcu, free_rootdomain); } static int init_rootdomain(struct root_domain *rd) @@ -6669,6 +6720,25 @@ static struct root_domain *alloc_rootdomain(void) return rd; } +static void free_sched_domain(struct rcu_head *rcu) +{ + struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); + if (atomic_dec_and_test(&sd->groups->ref)) + kfree(sd->groups); + kfree(sd); +} + +static void destroy_sched_domain(struct sched_domain *sd, int cpu) +{ + call_rcu(&sd->rcu, free_sched_domain); +} + +static void destroy_sched_domains(struct sched_domain *sd, int cpu) +{ + for (; sd; sd = sd->parent) + destroy_sched_domain(sd, cpu); +} + /* * Attach the domain 'sd' to 'cpu' as its base domain. Callers must * hold the hotplug lock. @@ -6679,9 +6749,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) struct rq *rq = cpu_rq(cpu); struct sched_domain *tmp; - for (tmp = sd; tmp; tmp = tmp->parent) - tmp->span_weight = cpumask_weight(sched_domain_span(tmp)); - /* Remove the sched domains which do not contribute to scheduling. */ for (tmp = sd; tmp; ) { struct sched_domain *parent = tmp->parent; @@ -6692,12 +6759,15 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) tmp->parent = parent->parent; if (parent->parent) parent->parent->child = tmp; + destroy_sched_domain(parent, cpu); } else tmp = tmp->parent; } if (sd && sd_degenerate(sd)) { + tmp = sd; sd = sd->parent; + destroy_sched_domain(tmp, cpu); if (sd) sd->child = NULL; } @@ -6705,7 +6775,9 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) sched_domain_debug(sd, cpu); rq_attach_root(rq, rd); + tmp = rq->sd; rcu_assign_pointer(rq->sd, sd); + destroy_sched_domains(tmp, cpu); } /* cpus with isolated domains */ @@ -6721,56 +6793,6 @@ static int __init isolated_cpu_setup(char *str) __setup("isolcpus=", isolated_cpu_setup); -/* - * init_sched_build_groups takes the cpumask we wish to span, and a pointer - * to a function which identifies what group(along with sched group) a CPU - * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids - * (due to the fact that we keep track of groups covered with a struct cpumask). - * - * init_sched_build_groups will build a circular linked list of the groups - * covered by the given span, and will set each group's ->cpumask correctly, - * and ->cpu_power to 0. - */ -static void -init_sched_build_groups(const struct cpumask *span, - const struct cpumask *cpu_map, - int (*group_fn)(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, - struct cpumask *tmpmask), - struct cpumask *covered, struct cpumask *tmpmask) -{ - struct sched_group *first = NULL, *last = NULL; - int i; - - cpumask_clear(covered); - - for_each_cpu(i, span) { - struct sched_group *sg; - int group = group_fn(i, cpu_map, &sg, tmpmask); - int j; - - if (cpumask_test_cpu(i, covered)) - continue; - - cpumask_clear(sched_group_cpus(sg)); - sg->cpu_power = 0; - - for_each_cpu(j, span) { - if (group_fn(j, cpu_map, NULL, tmpmask) != group) - continue; - - cpumask_set_cpu(j, covered); - cpumask_set_cpu(j, sched_group_cpus(sg)); - } - if (!first) - first = sg; - if (last) - last->next = sg; - last = sg; - } - last->next = first; -} - #define SD_NODES_PER_DOMAIN 16 #ifdef CONFIG_NUMA @@ -6787,7 +6809,7 @@ init_sched_build_groups(const struct cpumask *span, */ static int find_next_best_node(int node, nodemask_t *used_nodes) { - int i, n, val, min_val, best_node = 0; + int i, n, val, min_val, best_node = -1; min_val = INT_MAX; @@ -6811,7 +6833,8 @@ static int find_next_best_node(int node, nodemask_t *used_nodes) } } - node_set(best_node, *used_nodes); + if (best_node != -1) + node_set(best_node, *used_nodes); return best_node; } @@ -6837,315 +6860,130 @@ static void sched_domain_node_span(int node, struct cpumask *span) for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { int next_node = find_next_best_node(node, &used_nodes); - + if (next_node < 0) + break; cpumask_or(span, span, cpumask_of_node(next_node)); } } + +static const struct cpumask *cpu_node_mask(int cpu) +{ + lockdep_assert_held(&sched_domains_mutex); + + sched_domain_node_span(cpu_to_node(cpu), sched_domains_tmpmask); + + return sched_domains_tmpmask; +} + +static const struct cpumask *cpu_allnodes_mask(int cpu) +{ + return cpu_possible_mask; +} #endif /* CONFIG_NUMA */ -int sched_smt_power_savings = 0, sched_mc_power_savings = 0; +static const struct cpumask *cpu_cpu_mask(int cpu) +{ + return cpumask_of_node(cpu_to_node(cpu)); +} -/* - * The cpus mask in sched_group and sched_domain hangs off the end. - * - * ( See the the comments in include/linux/sched.h:struct sched_group - * and struct sched_domain. ) - */ -struct static_sched_group { - struct sched_group sg; - DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); -}; +int sched_smt_power_savings = 0, sched_mc_power_savings = 0; -struct static_sched_domain { - struct sched_domain sd; - DECLARE_BITMAP(span, CONFIG_NR_CPUS); +struct sd_data { + struct sched_domain **__percpu sd; + struct sched_group **__percpu sg; }; struct s_data { -#ifdef CONFIG_NUMA - int sd_allnodes; - cpumask_var_t domainspan; - cpumask_var_t covered; - cpumask_var_t notcovered; -#endif - cpumask_var_t nodemask; - cpumask_var_t this_sibling_map; - cpumask_var_t this_core_map; - cpumask_var_t this_book_map; - cpumask_var_t send_covered; - cpumask_var_t tmpmask; - struct sched_group **sched_group_nodes; + struct sched_domain ** __percpu sd; struct root_domain *rd; }; enum s_alloc { - sa_sched_groups = 0, sa_rootdomain, - sa_tmpmask, - sa_send_covered, - sa_this_book_map, - sa_this_core_map, - sa_this_sibling_map, - sa_nodemask, - sa_sched_group_nodes, -#ifdef CONFIG_NUMA - sa_notcovered, - sa_covered, - sa_domainspan, -#endif + sa_sd, + sa_sd_storage, sa_none, }; -/* - * SMT sched-domains: - */ -#ifdef CONFIG_SCHED_SMT -static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_groups); +struct sched_domain_topology_level; -static int -cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *unused) -{ - if (sg) - *sg = &per_cpu(sched_groups, cpu).sg; - return cpu; -} -#endif /* CONFIG_SCHED_SMT */ +typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu); +typedef const struct cpumask *(*sched_domain_mask_f)(int cpu); -/* - * multi-core sched-domains: - */ -#ifdef CONFIG_SCHED_MC -static DEFINE_PER_CPU(struct static_sched_domain, core_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); - -static int -cpu_to_core_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *mask) -{ - int group; -#ifdef CONFIG_SCHED_SMT - cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); - group = cpumask_first(mask); -#else - group = cpu; -#endif - if (sg) - *sg = &per_cpu(sched_group_core, group).sg; - return group; -} -#endif /* CONFIG_SCHED_MC */ +struct sched_domain_topology_level { + sched_domain_init_f init; + sched_domain_mask_f mask; + struct sd_data data; +}; /* - * book sched-domains: + * Assumes the sched_domain tree is fully constructed */ -#ifdef CONFIG_SCHED_BOOK -static DEFINE_PER_CPU(struct static_sched_domain, book_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_book); - -static int -cpu_to_book_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *mask) +static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) { - int group = cpu; -#ifdef CONFIG_SCHED_MC - cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); - group = cpumask_first(mask); -#elif defined(CONFIG_SCHED_SMT) - cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); - group = cpumask_first(mask); -#endif - if (sg) - *sg = &per_cpu(sched_group_book, group).sg; - return group; -} -#endif /* CONFIG_SCHED_BOOK */ + struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); + struct sched_domain *child = sd->child; -static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); + if (child) + cpu = cpumask_first(sched_domain_span(child)); -static int -cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, struct cpumask *mask) -{ - int group; -#ifdef CONFIG_SCHED_BOOK - cpumask_and(mask, cpu_book_mask(cpu), cpu_map); - group = cpumask_first(mask); -#elif defined(CONFIG_SCHED_MC) - cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); - group = cpumask_first(mask); -#elif defined(CONFIG_SCHED_SMT) - cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); - group = cpumask_first(mask); -#else - group = cpu; -#endif if (sg) - *sg = &per_cpu(sched_group_phys, group).sg; - return group; + *sg = *per_cpu_ptr(sdd->sg, cpu); + + return cpu; } -#ifdef CONFIG_NUMA /* - * The init_sched_build_groups can't handle what we want to do with node - * groups, so roll our own. Now each node has its own list of groups which - * gets dynamically allocated. + * build_sched_groups takes the cpumask we wish to span, and a pointer + * to a function which identifies what group(along with sched group) a CPU + * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids + * (due to the fact that we keep track of groups covered with a struct cpumask). + * + * build_sched_groups will build a circular linked list of the groups + * covered by the given span, and will set each group's ->cpumask correctly, + * and ->cpu_power to 0. */ -static DEFINE_PER_CPU(struct static_sched_domain, node_domains); -static struct sched_group ***sched_group_nodes_bycpu; - -static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); -static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); - -static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, - struct sched_group **sg, - struct cpumask *nodemask) -{ - int group; - - cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); - group = cpumask_first(nodemask); - - if (sg) - *sg = &per_cpu(sched_group_allnodes, group).sg; - return group; -} - -static void init_numa_sched_groups_power(struct sched_group *group_head) -{ - struct sched_group *sg = group_head; - int j; - - if (!sg) - return; - do { - for_each_cpu(j, sched_group_cpus(sg)) { - struct sched_domain *sd; - - sd = &per_cpu(phys_domains, j).sd; - if (j != group_first_cpu(sd->groups)) { - /* - * Only add "power" once for each - * physical package. - */ - continue; - } - - sg->cpu_power += sd->groups->cpu_power; - } - sg = sg->next; - } while (sg != group_head); -} - -static int build_numa_sched_groups(struct s_data *d, - const struct cpumask *cpu_map, int num) +static void +build_sched_groups(struct sched_domain *sd) { - struct sched_domain *sd; - struct sched_group *sg, *prev; - int n, j; - - cpumask_clear(d->covered); - cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map); - if (cpumask_empty(d->nodemask)) { - d->sched_group_nodes[num] = NULL; - goto out; - } - - sched_domain_node_span(num, d->domainspan); - cpumask_and(d->domainspan, d->domainspan, cpu_map); - - sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), - GFP_KERNEL, num); - if (!sg) { - printk(KERN_WARNING "Can not alloc domain group for node %d\n", - num); - return -ENOMEM; - } - d->sched_group_nodes[num] = sg; - - for_each_cpu(j, d->nodemask) { - sd = &per_cpu(node_domains, j).sd; - sd->groups = sg; - } - - sg->cpu_power = 0; - cpumask_copy(sched_group_cpus(sg), d->nodemask); - sg->next = sg; - cpumask_or(d->covered, d->covered, d->nodemask); + struct sched_group *first = NULL, *last = NULL; + struct sd_data *sdd = sd->private; + const struct cpumask *span = sched_domain_span(sd); + struct cpumask *covered; + int i; - prev = sg; - for (j = 0; j < nr_node_ids; j++) { - n = (num + j) % nr_node_ids; - cpumask_complement(d->notcovered, d->covered); - cpumask_and(d->tmpmask, d->notcovered, cpu_map); - cpumask_and(d->tmpmask, d->tmpmask, d->domainspan); - if (cpumask_empty(d->tmpmask)) - break; - cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n)); - if (cpumask_empty(d->tmpmask)) - continue; - sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), - GFP_KERNEL, num); - if (!sg) { - printk(KERN_WARNING - "Can not alloc domain group for node %d\n", j); - return -ENOMEM; - } - sg->cpu_power = 0; - cpumask_copy(sched_group_cpus(sg), d->tmpmask); - sg->next = prev->next; - cpumask_or(d->covered, d->covered, d->tmpmask); - prev->next = sg; - prev = sg; - } -out: - return 0; -} -#endif /* CONFIG_NUMA */ + lockdep_assert_held(&sched_domains_mutex); + covered = sched_domains_tmpmask; -#ifdef CONFIG_NUMA -/* Free memory allocated for various sched_group structures */ -static void free_sched_groups(const struct cpumask *cpu_map, - struct cpumask *nodemask) -{ - int cpu, i; + cpumask_clear(covered); - for_each_cpu(cpu, cpu_map) { - struct sched_group **sched_group_nodes - = sched_group_nodes_bycpu[cpu]; + for_each_cpu(i, span) { + struct sched_group *sg; + int group = get_group(i, sdd, &sg); + int j; - if (!sched_group_nodes) + if (cpumask_test_cpu(i, covered)) continue; - for (i = 0; i < nr_node_ids; i++) { - struct sched_group *oldsg, *sg = sched_group_nodes[i]; + cpumask_clear(sched_group_cpus(sg)); + sg->cpu_power = 0; - cpumask_and(nodemask, cpumask_of_node(i), cpu_map); - if (cpumask_empty(nodemask)) + for_each_cpu(j, span) { + if (get_group(j, sdd, NULL) != group) continue; - if (sg == NULL) - continue; - sg = sg->next; -next_sg: - oldsg = sg; - sg = sg->next; - kfree(oldsg); - if (oldsg != sched_group_nodes[i]) - goto next_sg; + cpumask_set_cpu(j, covered); + cpumask_set_cpu(j, sched_group_cpus(sg)); } - kfree(sched_group_nodes); - sched_group_nodes_bycpu[cpu] = NULL; + + if (!first) + first = sg; + if (last) + last->next = sg; + last = sg; } + last->next = first; } -#else /* !CONFIG_NUMA */ -static void free_sched_groups(const struct cpumask *cpu_map, - struct cpumask *nodemask) -{ -} -#endif /* CONFIG_NUMA */ /* * Initialize sched groups cpu_power. @@ -7159,11 +6997,6 @@ static void free_sched_groups(const struct cpumask *cpu_map, */ static void init_sched_groups_power(int cpu, struct sched_domain *sd) { - struct sched_domain *child; - struct sched_group *group; - long power; - int weight; - WARN_ON(!sd || !sd->groups); if (cpu != group_first_cpu(sd->groups)) @@ -7171,36 +7004,7 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd) sd->groups->group_weight = cpumask_weight(sched_group_cpus(sd->groups)); - child = sd->child; - - sd->groups->cpu_power = 0; - - if (!child) { - power = SCHED_LOAD_SCALE; - weight = cpumask_weight(sched_domain_span(sd)); - /* - * SMT siblings share the power of a single core. - * Usually multiple threads get a better yield out of - * that one core than a single thread would have, - * reflect that in sd->smt_gain. - */ - if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { - power *= sd->smt_gain; - power /= weight; - power >>= SCHED_LOAD_SHIFT; - } - sd->groups->cpu_power += power; - return; - } - - /* - * Add cpu_power of each child group to this groups cpu_power. - */ - group = child->groups; - do { - sd->groups->cpu_power += group->cpu_power; - group = group->next; - } while (group != child->groups); + update_group_power(sd, cpu); } /* @@ -7214,15 +7018,15 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd) # define SD_INIT_NAME(sd, type) do { } while (0) #endif -#define SD_INIT(sd, type) sd_init_##type(sd) - -#define SD_INIT_FUNC(type) \ -static noinline void sd_init_##type(struct sched_domain *sd) \ -{ \ - memset(sd, 0, sizeof(*sd)); \ - *sd = SD_##type##_INIT; \ - sd->level = SD_LV_##type; \ - SD_INIT_NAME(sd, type); \ +#define SD_INIT_FUNC(type) \ +static noinline struct sched_domain * \ +sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \ +{ \ + struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); \ + *sd = SD_##type##_INIT; \ + SD_INIT_NAME(sd, type); \ + sd->private = &tl->data; \ + return sd; \ } SD_INIT_FUNC(CPU) @@ -7241,13 +7045,14 @@ SD_INIT_FUNC(CPU) #endif static int default_relax_domain_level = -1; +int sched_domain_level_max; static int __init setup_relax_domain_level(char *str) { unsigned long val; val = simple_strtoul(str, NULL, 0); - if (val < SD_LV_MAX) + if (val < sched_domain_level_max) default_relax_domain_level = val; return 1; @@ -7275,37 +7080,20 @@ static void set_domain_attribute(struct sched_domain *sd, } } +static void __sdt_free(const struct cpumask *cpu_map); +static int __sdt_alloc(const struct cpumask *cpu_map); + static void __free_domain_allocs(struct s_data *d, enum s_alloc what, const struct cpumask *cpu_map) { switch (what) { - case sa_sched_groups: - free_sched_groups(cpu_map, d->tmpmask); /* fall through */ - d->sched_group_nodes = NULL; case sa_rootdomain: - free_rootdomain(d->rd); /* fall through */ - case sa_tmpmask: - free_cpumask_var(d->tmpmask); /* fall through */ - case sa_send_covered: - free_cpumask_var(d->send_covered); /* fall through */ - case sa_this_book_map: - free_cpumask_var(d->this_book_map); /* fall through */ - case sa_this_core_map: - free_cpumask_var(d->this_core_map); /* fall through */ - case sa_this_sibling_map: - free_cpumask_var(d->this_sibling_map); /* fall through */ - case sa_nodemask: - free_cpumask_var(d->nodemask); /* fall through */ - case sa_sched_group_nodes: -#ifdef CONFIG_NUMA - kfree(d->sched_group_nodes); /* fall through */ - case sa_notcovered: - free_cpumask_var(d->notcovered); /* fall through */ - case sa_covered: - free_cpumask_var(d->covered); /* fall through */ - case sa_domainspan: - free_cpumask_var(d->domainspan); /* fall through */ -#endif + if (!atomic_read(&d->rd->refcount)) + free_rootdomain(&d->rd->rcu); /* fall through */ + case sa_sd: + free_percpu(d->sd); /* fall through */ + case sa_sd_storage: + __sdt_free(cpu_map); /* fall through */ case sa_none: break; } @@ -7314,308 +7102,212 @@ static void __free_domain_allocs(struct s_data *d, enum s_alloc what, static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, const struct cpumask *cpu_map) { -#ifdef CONFIG_NUMA - if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL)) - return sa_none; - if (!alloc_cpumask_var(&d->covered, GFP_KERNEL)) - return sa_domainspan; - if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL)) - return sa_covered; - /* Allocate the per-node list of sched groups */ - d->sched_group_nodes = kcalloc(nr_node_ids, - sizeof(struct sched_group *), GFP_KERNEL); - if (!d->sched_group_nodes) { - printk(KERN_WARNING "Can not alloc sched group node list\n"); - return sa_notcovered; - } - sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes; -#endif - if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL)) - return sa_sched_group_nodes; - if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL)) - return sa_nodemask; - if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL)) - return sa_this_sibling_map; - if (!alloc_cpumask_var(&d->this_book_map, GFP_KERNEL)) - return sa_this_core_map; - if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL)) - return sa_this_book_map; - if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL)) - return sa_send_covered; + memset(d, 0, sizeof(*d)); + + if (__sdt_alloc(cpu_map)) + return sa_sd_storage; + d->sd = alloc_percpu(struct sched_domain *); + if (!d->sd) + return sa_sd_storage; d->rd = alloc_rootdomain(); - if (!d->rd) { - printk(KERN_WARNING "Cannot alloc root domain\n"); - return sa_tmpmask; - } + if (!d->rd) + return sa_sd; return sa_rootdomain; } -static struct sched_domain *__build_numa_sched_domains(struct s_data *d, - const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i) +/* + * NULL the sd_data elements we've used to build the sched_domain and + * sched_group structure so that the subsequent __free_domain_allocs() + * will not free the data we're using. + */ +static void claim_allocations(int cpu, struct sched_domain *sd) { - struct sched_domain *sd = NULL; -#ifdef CONFIG_NUMA - struct sched_domain *parent; - - d->sd_allnodes = 0; - if (cpumask_weight(cpu_map) > - SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) { - sd = &per_cpu(allnodes_domains, i).sd; - SD_INIT(sd, ALLNODES); - set_domain_attribute(sd, attr); - cpumask_copy(sched_domain_span(sd), cpu_map); - cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask); - d->sd_allnodes = 1; - } - parent = sd; - - sd = &per_cpu(node_domains, i).sd; - SD_INIT(sd, NODE); - set_domain_attribute(sd, attr); - sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); - sd->parent = parent; - if (parent) - parent->child = sd; - cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map); -#endif - return sd; -} + struct sd_data *sdd = sd->private; + struct sched_group *sg = sd->groups; -static struct sched_domain *__build_cpu_sched_domain(struct s_data *d, - const struct cpumask *cpu_map, struct sched_domain_attr *attr, - struct sched_domain *parent, int i) -{ - struct sched_domain *sd; - sd = &per_cpu(phys_domains, i).sd; - SD_INIT(sd, CPU); - set_domain_attribute(sd, attr); - cpumask_copy(sched_domain_span(sd), d->nodemask); - sd->parent = parent; - if (parent) - parent->child = sd; - cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask); - return sd; -} + WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); + *per_cpu_ptr(sdd->sd, cpu) = NULL; -static struct sched_domain *__build_book_sched_domain(struct s_data *d, - const struct cpumask *cpu_map, struct sched_domain_attr *attr, - struct sched_domain *parent, int i) -{ - struct sched_domain *sd = parent; -#ifdef CONFIG_SCHED_BOOK - sd = &per_cpu(book_domains, i).sd; - SD_INIT(sd, BOOK); - set_domain_attribute(sd, attr); - cpumask_and(sched_domain_span(sd), cpu_map, cpu_book_mask(i)); - sd->parent = parent; - parent->child = sd; - cpu_to_book_group(i, cpu_map, &sd->groups, d->tmpmask); -#endif - return sd; + if (cpu == cpumask_first(sched_group_cpus(sg))) { + WARN_ON_ONCE(*per_cpu_ptr(sdd->sg, cpu) != sg); + *per_cpu_ptr(sdd->sg, cpu) = NULL; + } } -static struct sched_domain *__build_mc_sched_domain(struct s_data *d, - const struct cpumask *cpu_map, struct sched_domain_attr *attr, - struct sched_domain *parent, int i) +#ifdef CONFIG_SCHED_SMT +static const struct cpumask *cpu_smt_mask(int cpu) { - struct sched_domain *sd = parent; -#ifdef CONFIG_SCHED_MC - sd = &per_cpu(core_domains, i).sd; - SD_INIT(sd, MC); - set_domain_attribute(sd, attr); - cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i)); - sd->parent = parent; - parent->child = sd; - cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask); -#endif - return sd; + return topology_thread_cpumask(cpu); } - -static struct sched_domain *__build_smt_sched_domain(struct s_data *d, - const struct cpumask *cpu_map, struct sched_domain_attr *attr, - struct sched_domain *parent, int i) -{ - struct sched_domain *sd = parent; -#ifdef CONFIG_SCHED_SMT - sd = &per_cpu(cpu_domains, i).sd; - SD_INIT(sd, SIBLING); - set_domain_attribute(sd, attr); - cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i)); - sd->parent = parent; - parent->child = sd; - cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask); #endif - return sd; -} -static void build_sched_groups(struct s_data *d, enum sched_domain_level l, - const struct cpumask *cpu_map, int cpu) -{ - switch (l) { +/* + * Topology list, bottom-up. + */ +static struct sched_domain_topology_level default_topology[] = { #ifdef CONFIG_SCHED_SMT - case SD_LV_SIBLING: /* set up CPU (sibling) groups */ - cpumask_and(d->this_sibling_map, cpu_map, - topology_thread_cpumask(cpu)); - if (cpu == cpumask_first(d->this_sibling_map)) - init_sched_build_groups(d->this_sibling_map, cpu_map, - &cpu_to_cpu_group, - d->send_covered, d->tmpmask); - break; + { sd_init_SIBLING, cpu_smt_mask, }, #endif #ifdef CONFIG_SCHED_MC - case SD_LV_MC: /* set up multi-core groups */ - cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu)); - if (cpu == cpumask_first(d->this_core_map)) - init_sched_build_groups(d->this_core_map, cpu_map, - &cpu_to_core_group, - d->send_covered, d->tmpmask); - break; + { sd_init_MC, cpu_coregroup_mask, }, #endif #ifdef CONFIG_SCHED_BOOK - case SD_LV_BOOK: /* set up book groups */ - cpumask_and(d->this_book_map, cpu_map, cpu_book_mask(cpu)); - if (cpu == cpumask_first(d->this_book_map)) - init_sched_build_groups(d->this_book_map, cpu_map, - &cpu_to_book_group, - d->send_covered, d->tmpmask); - break; + { sd_init_BOOK, cpu_book_mask, }, #endif - case SD_LV_CPU: /* set up physical groups */ - cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map); - if (!cpumask_empty(d->nodemask)) - init_sched_build_groups(d->nodemask, cpu_map, - &cpu_to_phys_group, - d->send_covered, d->tmpmask); - break; + { sd_init_CPU, cpu_cpu_mask, }, #ifdef CONFIG_NUMA - case SD_LV_ALLNODES: - init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group, - d->send_covered, d->tmpmask); - break; + { sd_init_NODE, cpu_node_mask, }, + { sd_init_ALLNODES, cpu_allnodes_mask, }, #endif - default: - break; + { NULL, }, +}; + +static struct sched_domain_topology_level *sched_domain_topology = default_topology; + +static int __sdt_alloc(const struct cpumask *cpu_map) +{ + struct sched_domain_topology_level *tl; + int j; + + for (tl = sched_domain_topology; tl->init; tl++) { + struct sd_data *sdd = &tl->data; + + sdd->sd = alloc_percpu(struct sched_domain *); + if (!sdd->sd) + return -ENOMEM; + + sdd->sg = alloc_percpu(struct sched_group *); + if (!sdd->sg) + return -ENOMEM; + + for_each_cpu(j, cpu_map) { + struct sched_domain *sd; + struct sched_group *sg; + + sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), + GFP_KERNEL, cpu_to_node(j)); + if (!sd) + return -ENOMEM; + + *per_cpu_ptr(sdd->sd, j) = sd; + + sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), + GFP_KERNEL, cpu_to_node(j)); + if (!sg) + return -ENOMEM; + + *per_cpu_ptr(sdd->sg, j) = sg; + } + } + + return 0; +} + +static void __sdt_free(const struct cpumask *cpu_map) +{ + struct sched_domain_topology_level *tl; + int j; + + for (tl = sched_domain_topology; tl->init; tl++) { + struct sd_data *sdd = &tl->data; + + for_each_cpu(j, cpu_map) { + kfree(*per_cpu_ptr(sdd->sd, j)); + kfree(*per_cpu_ptr(sdd->sg, j)); + } + free_percpu(sdd->sd); + free_percpu(sdd->sg); + } +} + +struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, + struct s_data *d, const struct cpumask *cpu_map, + struct sched_domain_attr *attr, struct sched_domain *child, + int cpu) +{ + struct sched_domain *sd = tl->init(tl, cpu); + if (!sd) + return child; + + set_domain_attribute(sd, attr); + cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); + if (child) { + sd->level = child->level + 1; + sched_domain_level_max = max(sched_domain_level_max, sd->level); + child->parent = sd; } + sd->child = child; + + return sd; } /* * Build sched domains for a given set of cpus and attach the sched domains * to the individual cpus */ -static int __build_sched_domains(const struct cpumask *cpu_map, - struct sched_domain_attr *attr) +static int build_sched_domains(const struct cpumask *cpu_map, + struct sched_domain_attr *attr) { enum s_alloc alloc_state = sa_none; - struct s_data d; struct sched_domain *sd; - int i; -#ifdef CONFIG_NUMA - d.sd_allnodes = 0; -#endif + struct s_data d; + int i, ret = -ENOMEM; alloc_state = __visit_domain_allocation_hell(&d, cpu_map); if (alloc_state != sa_rootdomain) goto error; - alloc_state = sa_sched_groups; - /* - * Set up domains for cpus specified by the cpu_map. - */ + /* Set up domains for cpus specified by the cpu_map. */ for_each_cpu(i, cpu_map) { - cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)), - cpu_map); + struct sched_domain_topology_level *tl; - sd = __build_numa_sched_domains(&d, cpu_map, attr, i); - sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i); - sd = __build_book_sched_domain(&d, cpu_map, attr, sd, i); - sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i); - sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i); - } - - for_each_cpu(i, cpu_map) { - build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i); - build_sched_groups(&d, SD_LV_BOOK, cpu_map, i); - build_sched_groups(&d, SD_LV_MC, cpu_map, i); - } - - /* Set up physical groups */ - for (i = 0; i < nr_node_ids; i++) - build_sched_groups(&d, SD_LV_CPU, cpu_map, i); + sd = NULL; + for (tl = sched_domain_topology; tl->init; tl++) + sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i); -#ifdef CONFIG_NUMA - /* Set up node groups */ - if (d.sd_allnodes) - build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0); - - for (i = 0; i < nr_node_ids; i++) - if (build_numa_sched_groups(&d, cpu_map, i)) - goto error; -#endif + while (sd->child) + sd = sd->child; - /* Calculate CPU power for physical packages and nodes */ -#ifdef CONFIG_SCHED_SMT - for_each_cpu(i, cpu_map) { - sd = &per_cpu(cpu_domains, i).sd; - init_sched_groups_power(i, sd); - } -#endif -#ifdef CONFIG_SCHED_MC - for_each_cpu(i, cpu_map) { - sd = &per_cpu(core_domains, i).sd; - init_sched_groups_power(i, sd); + *per_cpu_ptr(d.sd, i) = sd; } -#endif -#ifdef CONFIG_SCHED_BOOK - for_each_cpu(i, cpu_map) { - sd = &per_cpu(book_domains, i).sd; - init_sched_groups_power(i, sd); - } -#endif + /* Build the groups for the domains */ for_each_cpu(i, cpu_map) { - sd = &per_cpu(phys_domains, i).sd; - init_sched_groups_power(i, sd); - } + for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { + sd->span_weight = cpumask_weight(sched_domain_span(sd)); + get_group(i, sd->private, &sd->groups); + atomic_inc(&sd->groups->ref); -#ifdef CONFIG_NUMA - for (i = 0; i < nr_node_ids; i++) - init_numa_sched_groups_power(d.sched_group_nodes[i]); + if (i != cpumask_first(sched_domain_span(sd))) + continue; - if (d.sd_allnodes) { - struct sched_group *sg; + build_sched_groups(sd); + } + } - cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, - d.tmpmask); - init_numa_sched_groups_power(sg); + /* Calculate CPU power for physical packages and nodes */ + for (i = nr_cpumask_bits-1; i >= 0; i--) { + if (!cpumask_test_cpu(i, cpu_map)) + continue; + + for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { + claim_allocations(i, sd); + init_sched_groups_power(i, sd); + } } -#endif /* Attach the domains */ + rcu_read_lock(); for_each_cpu(i, cpu_map) { -#ifdef CONFIG_SCHED_SMT - sd = &per_cpu(cpu_domains, i).sd; -#elif defined(CONFIG_SCHED_MC) - sd = &per_cpu(core_domains, i).sd; -#elif defined(CONFIG_SCHED_BOOK) - sd = &per_cpu(book_domains, i).sd; -#else - sd = &per_cpu(phys_domains, i).sd; -#endif + sd = *per_cpu_ptr(d.sd, i); cpu_attach_domain(sd, d.rd, i); } + rcu_read_unlock(); - d.sched_group_nodes = NULL; /* don't free this we still need it */ - __free_domain_allocs(&d, sa_tmpmask, cpu_map); - return 0; - + ret = 0; error: __free_domain_allocs(&d, alloc_state, cpu_map); - return -ENOMEM; -} - -static int build_sched_domains(const struct cpumask *cpu_map) -{ - return __build_sched_domains(cpu_map, NULL); + return ret; } static cpumask_var_t *doms_cur; /* current sched domains */ @@ -7670,7 +7362,7 @@ void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) * For now this just excludes isolated cpus, but could be used to * exclude other special cases in the future. */ -static int arch_init_sched_domains(const struct cpumask *cpu_map) +static int init_sched_domains(const struct cpumask *cpu_map) { int err; @@ -7681,32 +7373,24 @@ static int arch_init_sched_domains(const struct cpumask *cpu_map) doms_cur = &fallback_doms; cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); dattr_cur = NULL; - err = build_sched_domains(doms_cur[0]); + err = build_sched_domains(doms_cur[0], NULL); register_sched_domain_sysctl(); return err; } -static void arch_destroy_sched_domains(const struct cpumask *cpu_map, - struct cpumask *tmpmask) -{ - free_sched_groups(cpu_map, tmpmask); -} - /* * Detach sched domains from a group of cpus specified in cpu_map * These cpus will now be attached to the NULL domain */ static void detach_destroy_domains(const struct cpumask *cpu_map) { - /* Save because hotplug lock held. */ - static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); int i; + rcu_read_lock(); for_each_cpu(i, cpu_map) cpu_attach_domain(NULL, &def_root_domain, i); - synchronize_sched(); - arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); + rcu_read_unlock(); } /* handle null as "default" */ @@ -7795,8 +7479,7 @@ match1: goto match2; } /* no match - add a new doms_new */ - __build_sched_domains(doms_new[i], - dattr_new ? dattr_new + i : NULL); + build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); match2: ; } @@ -7815,7 +7498,7 @@ match2: } #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) -static void arch_reinit_sched_domains(void) +static void reinit_sched_domains(void) { get_online_cpus(); @@ -7848,7 +7531,7 @@ static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) else sched_mc_power_savings = level; - arch_reinit_sched_domains(); + reinit_sched_domains(); return count; } @@ -7967,14 +7650,9 @@ void __init sched_init_smp(void) alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); alloc_cpumask_var(&fallback_doms, GFP_KERNEL); -#if defined(CONFIG_NUMA) - sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), - GFP_KERNEL); - BUG_ON(sched_group_nodes_bycpu == NULL); -#endif get_online_cpus(); mutex_lock(&sched_domains_mutex); - arch_init_sched_domains(cpu_active_mask); + init_sched_domains(cpu_active_mask); cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); if (cpumask_empty(non_isolated_cpus)) cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); @@ -8281,6 +7959,7 @@ void __init sched_init(void) /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); #ifdef CONFIG_SMP + zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT); #ifdef CONFIG_NO_HZ zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); alloc_cpumask_var(&nohz.grp_idle_mask, GFP_NOWAIT); @@ -8340,7 +8019,7 @@ static void normalize_task(struct rq *rq, struct task_struct *p) int old_prio = p->prio; int on_rq; - on_rq = p->se.on_rq; + on_rq = p->on_rq; if (on_rq) deactivate_task(rq, p, 0); __setscheduler(rq, p, SCHED_NORMAL, 0); @@ -8553,7 +8232,6 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) { struct rt_rq *rt_rq; struct sched_rt_entity *rt_se; - struct rq *rq; int i; tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); @@ -8567,8 +8245,6 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) ktime_to_ns(def_rt_bandwidth.rt_period), 0); for_each_possible_cpu(i) { - rq = cpu_rq(i); - rt_rq = kzalloc_node(sizeof(struct rt_rq), GFP_KERNEL, cpu_to_node(i)); if (!rt_rq) @@ -8683,7 +8359,7 @@ void sched_move_task(struct task_struct *tsk) rq = task_rq_lock(tsk, &flags); running = task_current(rq, tsk); - on_rq = tsk->se.on_rq; + on_rq = tsk->on_rq; if (on_rq) dequeue_task(rq, tsk, 0); @@ -8702,7 +8378,7 @@ void sched_move_task(struct task_struct *tsk) if (on_rq) enqueue_task(rq, tsk, 0); - task_rq_unlock(rq, &flags); + task_rq_unlock(rq, tsk, &flags); } #endif /* CONFIG_CGROUP_SCHED */ diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 7bacd83a4158..a6710a112b4f 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -152,7 +152,7 @@ static void print_rq(struct seq_file *m, struct rq *rq, int rq_cpu) read_lock_irqsave(&tasklist_lock, flags); do_each_thread(g, p) { - if (!p->se.on_rq || task_cpu(p) != rq_cpu) + if (!p->on_rq || task_cpu(p) != rq_cpu) continue; print_task(m, rq, p); @@ -296,9 +296,6 @@ static void print_cpu(struct seq_file *m, int cpu) P(ttwu_count); P(ttwu_local); - SEQ_printf(m, " .%-30s: %d\n", "bkl_count", - rq->rq_sched_info.bkl_count); - #undef P #undef P64 #endif @@ -441,7 +438,6 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) P(se.statistics.wait_count); PN(se.statistics.iowait_sum); P(se.statistics.iowait_count); - P(sched_info.bkl_count); P(se.nr_migrations); P(se.statistics.nr_migrations_cold); P(se.statistics.nr_failed_migrations_affine); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 6fa833ab2cb8..37f22626225e 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -358,6 +358,10 @@ static void update_min_vruntime(struct cfs_rq *cfs_rq) } cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime); +#ifndef CONFIG_64BIT + smp_wmb(); + cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime; +#endif } /* @@ -1340,6 +1344,8 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) hrtick_update(rq); } +static void set_next_buddy(struct sched_entity *se); + /* * The dequeue_task method is called before nr_running is * decreased. We remove the task from the rbtree and @@ -1349,14 +1355,22 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) { struct cfs_rq *cfs_rq; struct sched_entity *se = &p->se; + int task_sleep = flags & DEQUEUE_SLEEP; for_each_sched_entity(se) { cfs_rq = cfs_rq_of(se); dequeue_entity(cfs_rq, se, flags); /* Don't dequeue parent if it has other entities besides us */ - if (cfs_rq->load.weight) + if (cfs_rq->load.weight) { + /* + * Bias pick_next to pick a task from this cfs_rq, as + * p is sleeping when it is within its sched_slice. + */ + if (task_sleep && parent_entity(se)) + set_next_buddy(parent_entity(se)); break; + } flags |= DEQUEUE_SLEEP; } @@ -1372,12 +1386,25 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags) #ifdef CONFIG_SMP -static void task_waking_fair(struct rq *rq, struct task_struct *p) +static void task_waking_fair(struct task_struct *p) { struct sched_entity *se = &p->se; struct cfs_rq *cfs_rq = cfs_rq_of(se); + u64 min_vruntime; - se->vruntime -= cfs_rq->min_vruntime; +#ifndef CONFIG_64BIT + u64 min_vruntime_copy; + + do { + min_vruntime_copy = cfs_rq->min_vruntime_copy; + smp_rmb(); + min_vruntime = cfs_rq->min_vruntime; + } while (min_vruntime != min_vruntime_copy); +#else + min_vruntime = cfs_rq->min_vruntime; +#endif + + se->vruntime -= min_vruntime; } #ifdef CONFIG_FAIR_GROUP_SCHED @@ -1622,6 +1649,7 @@ static int select_idle_sibling(struct task_struct *p, int target) /* * Otherwise, iterate the domains and find an elegible idle cpu. */ + rcu_read_lock(); for_each_domain(target, sd) { if (!(sd->flags & SD_SHARE_PKG_RESOURCES)) break; @@ -1641,6 +1669,7 @@ static int select_idle_sibling(struct task_struct *p, int target) cpumask_test_cpu(prev_cpu, sched_domain_span(sd))) break; } + rcu_read_unlock(); return target; } @@ -1657,7 +1686,7 @@ static int select_idle_sibling(struct task_struct *p, int target) * preempt must be disabled. */ static int -select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_flags) +select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags) { struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL; int cpu = smp_processor_id(); @@ -1673,6 +1702,7 @@ select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_ new_cpu = prev_cpu; } + rcu_read_lock(); for_each_domain(cpu, tmp) { if (!(tmp->flags & SD_LOAD_BALANCE)) continue; @@ -1723,9 +1753,10 @@ select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_ if (affine_sd) { if (cpu == prev_cpu || wake_affine(affine_sd, p, sync)) - return select_idle_sibling(p, cpu); - else - return select_idle_sibling(p, prev_cpu); + prev_cpu = cpu; + + new_cpu = select_idle_sibling(p, prev_cpu); + goto unlock; } while (sd) { @@ -1766,6 +1797,8 @@ select_task_rq_fair(struct rq *rq, struct task_struct *p, int sd_flag, int wake_ } /* while loop will break here if sd == NULL */ } +unlock: + rcu_read_unlock(); return new_cpu; } @@ -1789,10 +1822,7 @@ wakeup_gran(struct sched_entity *curr, struct sched_entity *se) * This is especially important for buddies when the leftmost * task is higher priority than the buddy. */ - if (unlikely(se->load.weight != NICE_0_LOAD)) - gran = calc_delta_fair(gran, se); - - return gran; + return calc_delta_fair(gran, se); } /* @@ -1826,26 +1856,26 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) static void set_last_buddy(struct sched_entity *se) { - if (likely(task_of(se)->policy != SCHED_IDLE)) { - for_each_sched_entity(se) - cfs_rq_of(se)->last = se; - } + if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE)) + return; + + for_each_sched_entity(se) + cfs_rq_of(se)->last = se; } static void set_next_buddy(struct sched_entity *se) { - if (likely(task_of(se)->policy != SCHED_IDLE)) { - for_each_sched_entity(se) - cfs_rq_of(se)->next = se; - } + if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE)) + return; + + for_each_sched_entity(se) + cfs_rq_of(se)->next = se; } static void set_skip_buddy(struct sched_entity *se) { - if (likely(task_of(se)->policy != SCHED_IDLE)) { - for_each_sched_entity(se) - cfs_rq_of(se)->skip = se; - } + for_each_sched_entity(se) + cfs_rq_of(se)->skip = se; } /* @@ -1857,12 +1887,15 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ struct sched_entity *se = &curr->se, *pse = &p->se; struct cfs_rq *cfs_rq = task_cfs_rq(curr); int scale = cfs_rq->nr_running >= sched_nr_latency; + int next_buddy_marked = 0; if (unlikely(se == pse)) return; - if (sched_feat(NEXT_BUDDY) && scale && !(wake_flags & WF_FORK)) + if (sched_feat(NEXT_BUDDY) && scale && !(wake_flags & WF_FORK)) { set_next_buddy(pse); + next_buddy_marked = 1; + } /* * We can come here with TIF_NEED_RESCHED already set from new task @@ -1890,8 +1923,15 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ update_curr(cfs_rq); find_matching_se(&se, &pse); BUG_ON(!pse); - if (wakeup_preempt_entity(se, pse) == 1) + if (wakeup_preempt_entity(se, pse) == 1) { + /* + * Bias pick_next to pick the sched entity that is + * triggering this preemption. + */ + if (!next_buddy_marked) + set_next_buddy(pse); goto preempt; + } return; @@ -2102,7 +2142,7 @@ static unsigned long balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long max_load_move, struct sched_domain *sd, enum cpu_idle_type idle, int *all_pinned, - int *this_best_prio, struct cfs_rq *busiest_cfs_rq) + struct cfs_rq *busiest_cfs_rq) { int loops = 0, pulled = 0; long rem_load_move = max_load_move; @@ -2140,9 +2180,6 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, */ if (rem_load_move <= 0) break; - - if (p->prio < *this_best_prio) - *this_best_prio = p->prio; } out: /* @@ -2202,7 +2239,7 @@ static unsigned long load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long max_load_move, struct sched_domain *sd, enum cpu_idle_type idle, - int *all_pinned, int *this_best_prio) + int *all_pinned) { long rem_load_move = max_load_move; int busiest_cpu = cpu_of(busiest); @@ -2227,7 +2264,7 @@ load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, rem_load = div_u64(rem_load, busiest_h_load + 1); moved_load = balance_tasks(this_rq, this_cpu, busiest, - rem_load, sd, idle, all_pinned, this_best_prio, + rem_load, sd, idle, all_pinned, busiest_cfs_rq); if (!moved_load) @@ -2253,11 +2290,11 @@ static unsigned long load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long max_load_move, struct sched_domain *sd, enum cpu_idle_type idle, - int *all_pinned, int *this_best_prio) + int *all_pinned) { return balance_tasks(this_rq, this_cpu, busiest, max_load_move, sd, idle, all_pinned, - this_best_prio, &busiest->cfs); + &busiest->cfs); } #endif @@ -2274,12 +2311,11 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, int *all_pinned) { unsigned long total_load_moved = 0, load_moved; - int this_best_prio = this_rq->curr->prio; do { load_moved = load_balance_fair(this_rq, this_cpu, busiest, max_load_move - total_load_moved, - sd, idle, all_pinned, &this_best_prio); + sd, idle, all_pinned); total_load_moved += load_moved; @@ -2648,7 +2684,7 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group) /* * Only siblings can have significantly less than SCHED_LOAD_SCALE */ - if (sd->level != SD_LV_SIBLING) + if (!(sd->flags & SD_SHARE_CPUPOWER)) return 0; /* @@ -3465,6 +3501,7 @@ static void idle_balance(int this_cpu, struct rq *this_rq) raw_spin_unlock(&this_rq->lock); update_shares(this_cpu); + rcu_read_lock(); for_each_domain(this_cpu, sd) { unsigned long interval; int balance = 1; @@ -3486,6 +3523,7 @@ static void idle_balance(int this_cpu, struct rq *this_rq) break; } } + rcu_read_unlock(); raw_spin_lock(&this_rq->lock); @@ -3534,6 +3572,7 @@ static int active_load_balance_cpu_stop(void *data) double_lock_balance(busiest_rq, target_rq); /* Search for an sd spanning us and the target CPU. */ + rcu_read_lock(); for_each_domain(target_cpu, sd) { if ((sd->flags & SD_LOAD_BALANCE) && cpumask_test_cpu(busiest_cpu, sched_domain_span(sd))) @@ -3549,6 +3588,7 @@ static int active_load_balance_cpu_stop(void *data) else schedstat_inc(sd, alb_failed); } + rcu_read_unlock(); double_unlock_balance(busiest_rq, target_rq); out_unlock: busiest_rq->active_balance = 0; @@ -3675,6 +3715,7 @@ static int find_new_ilb(int cpu) { struct sched_domain *sd; struct sched_group *ilb_group; + int ilb = nr_cpu_ids; /* * Have idle load balancer selection from semi-idle packages only @@ -3690,20 +3731,25 @@ static int find_new_ilb(int cpu) if (cpumask_weight(nohz.idle_cpus_mask) < 2) goto out_done; + rcu_read_lock(); for_each_flag_domain(cpu, sd, SD_POWERSAVINGS_BALANCE) { ilb_group = sd->groups; do { - if (is_semi_idle_group(ilb_group)) - return cpumask_first(nohz.grp_idle_mask); + if (is_semi_idle_group(ilb_group)) { + ilb = cpumask_first(nohz.grp_idle_mask); + goto unlock; + } ilb_group = ilb_group->next; } while (ilb_group != sd->groups); } +unlock: + rcu_read_unlock(); out_done: - return nr_cpu_ids; + return ilb; } #else /* (CONFIG_SCHED_MC || CONFIG_SCHED_SMT) */ static inline int find_new_ilb(int call_cpu) @@ -3848,6 +3894,7 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle) update_shares(cpu); + rcu_read_lock(); for_each_domain(cpu, sd) { if (!(sd->flags & SD_LOAD_BALANCE)) continue; @@ -3893,6 +3940,7 @@ out: if (!balance) break; } + rcu_read_unlock(); /* * next_balance will be updated only when there is a need. diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 68e69acc29b9..be40f7371ee1 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -64,3 +64,9 @@ SCHED_FEAT(OWNER_SPIN, 1) * Decrement CPU power based on irq activity */ SCHED_FEAT(NONIRQ_POWER, 1) + +/* + * Queue remote wakeups on the target CPU and process them + * using the scheduler IPI. Reduces rq->lock contention/bounces. + */ +SCHED_FEAT(TTWU_QUEUE, 1) diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index a776a6396427..0a51882534ea 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -7,7 +7,7 @@ #ifdef CONFIG_SMP static int -select_task_rq_idle(struct rq *rq, struct task_struct *p, int sd_flag, int flags) +select_task_rq_idle(struct task_struct *p, int sd_flag, int flags) { return task_cpu(p); /* IDLE tasks as never migrated */ } diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index e7cebdc65f82..64b2a37c07d0 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -183,6 +183,14 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq) return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period); } +typedef struct task_group *rt_rq_iter_t; + +#define for_each_rt_rq(rt_rq, iter, rq) \ + for (iter = list_entry_rcu(task_groups.next, typeof(*iter), list); \ + (&iter->list != &task_groups) && \ + (rt_rq = iter->rt_rq[cpu_of(rq)]); \ + iter = list_entry_rcu(iter->list.next, typeof(*iter), list)) + static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq) { list_add_rcu(&rt_rq->leaf_rt_rq_list, @@ -288,6 +296,11 @@ static inline u64 sched_rt_period(struct rt_rq *rt_rq) return ktime_to_ns(def_rt_bandwidth.rt_period); } +typedef struct rt_rq *rt_rq_iter_t; + +#define for_each_rt_rq(rt_rq, iter, rq) \ + for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) + static inline void list_add_leaf_rt_rq(struct rt_rq *rt_rq) { } @@ -402,12 +415,13 @@ next: static void __disable_runtime(struct rq *rq) { struct root_domain *rd = rq->rd; + rt_rq_iter_t iter; struct rt_rq *rt_rq; if (unlikely(!scheduler_running)) return; - for_each_leaf_rt_rq(rt_rq, rq) { + for_each_rt_rq(rt_rq, iter, rq) { struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); s64 want; int i; @@ -487,6 +501,7 @@ static void disable_runtime(struct rq *rq) static void __enable_runtime(struct rq *rq) { + rt_rq_iter_t iter; struct rt_rq *rt_rq; if (unlikely(!scheduler_running)) @@ -495,7 +510,7 @@ static void __enable_runtime(struct rq *rq) /* * Reset each runqueue's bandwidth settings */ - for_each_leaf_rt_rq(rt_rq, rq) { + for_each_rt_rq(rt_rq, iter, rq) { struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); raw_spin_lock(&rt_b->rt_runtime_lock); @@ -562,6 +577,13 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) { rt_rq->rt_throttled = 0; enqueue = 1; + + /* + * Force a clock update if the CPU was idle, + * lest wakeup -> unthrottle time accumulate. + */ + if (rt_rq->rt_nr_running && rq->curr == rq->idle) + rq->skip_clock_update = -1; } if (rt_rq->rt_time || rt_rq->rt_nr_running) idle = 0; @@ -977,13 +999,23 @@ static void yield_task_rt(struct rq *rq) static int find_lowest_rq(struct task_struct *task); static int -select_task_rq_rt(struct rq *rq, struct task_struct *p, int sd_flag, int flags) +select_task_rq_rt(struct task_struct *p, int sd_flag, int flags) { + struct task_struct *curr; + struct rq *rq; + int cpu; + if (sd_flag != SD_BALANCE_WAKE) return smp_processor_id(); + cpu = task_cpu(p); + rq = cpu_rq(cpu); + + rcu_read_lock(); + curr = ACCESS_ONCE(rq->curr); /* unlocked access */ + /* - * If the current task is an RT task, then + * If the current task on @p's runqueue is an RT task, then * try to see if we can wake this RT task up on another * runqueue. Otherwise simply start this RT task * on its current runqueue. @@ -997,21 +1029,25 @@ select_task_rq_rt(struct rq *rq, struct task_struct *p, int sd_flag, int flags) * lock? * * For equal prio tasks, we just let the scheduler sort it out. + * + * Otherwise, just let it ride on the affined RQ and the + * post-schedule router will push the preempted task away + * + * This test is optimistic, if we get it wrong the load-balancer + * will have to sort it out. */ - if (unlikely(rt_task(rq->curr)) && - (rq->curr->rt.nr_cpus_allowed < 2 || - rq->curr->prio < p->prio) && + if (curr && unlikely(rt_task(curr)) && + (curr->rt.nr_cpus_allowed < 2 || + curr->prio < p->prio) && (p->rt.nr_cpus_allowed > 1)) { - int cpu = find_lowest_rq(p); + int target = find_lowest_rq(p); - return (cpu == -1) ? task_cpu(p) : cpu; + if (target != -1) + cpu = target; } + rcu_read_unlock(); - /* - * Otherwise, just let it ride on the affined RQ and the - * post-schedule router will push the preempted task away - */ - return task_cpu(p); + return cpu; } static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) @@ -1136,7 +1172,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p) * The previous task needs to be made eligible for pushing * if it is still active */ - if (p->se.on_rq && p->rt.nr_cpus_allowed > 1) + if (on_rt_rq(&p->rt) && p->rt.nr_cpus_allowed > 1) enqueue_pushable_task(rq, p); } @@ -1287,7 +1323,7 @@ static struct rq *find_lock_lowest_rq(struct task_struct *task, struct rq *rq) !cpumask_test_cpu(lowest_rq->cpu, &task->cpus_allowed) || task_running(rq, task) || - !task->se.on_rq)) { + !task->on_rq)) { raw_spin_unlock(&lowest_rq->lock); lowest_rq = NULL; @@ -1321,7 +1357,7 @@ static struct task_struct *pick_next_pushable_task(struct rq *rq) BUG_ON(task_current(rq, p)); BUG_ON(p->rt.nr_cpus_allowed <= 1); - BUG_ON(!p->se.on_rq); + BUG_ON(!p->on_rq); BUG_ON(!rt_task(p)); return p; @@ -1467,7 +1503,7 @@ static int pull_rt_task(struct rq *this_rq) */ if (p && (p->prio < this_rq->rt.highest_prio.curr)) { WARN_ON(p == src_rq->curr); - WARN_ON(!p->se.on_rq); + WARN_ON(!p->on_rq); /* * There's a chance that p is higher in priority @@ -1538,7 +1574,7 @@ static void set_cpus_allowed_rt(struct task_struct *p, * Update the migration status of the RQ if we have an RT task * which is running AND changing its weight value. */ - if (p->se.on_rq && (weight != p->rt.nr_cpus_allowed)) { + if (p->on_rq && (weight != p->rt.nr_cpus_allowed)) { struct rq *rq = task_rq(p); if (!task_current(rq, p)) { @@ -1608,7 +1644,7 @@ 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->se.on_rq && !rq->rt.rt_nr_running) + if (p->on_rq && !rq->rt.rt_nr_running) pull_rt_task(rq); } @@ -1638,7 +1674,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p) * If that current running task is also an RT task * then see if we can move to another run queue. */ - if (p->se.on_rq && rq->curr != p) { + if (p->on_rq && rq->curr != p) { #ifdef CONFIG_SMP if (rq->rt.overloaded && push_rt_task(rq) && /* Don't resched if we changed runqueues */ @@ -1657,7 +1693,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p) static void prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio) { - if (!p->se.on_rq) + if (!p->on_rq) return; if (rq->curr == p) { @@ -1796,10 +1832,11 @@ extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); static void print_rt_stats(struct seq_file *m, int cpu) { + rt_rq_iter_t iter; struct rt_rq *rt_rq; rcu_read_lock(); - for_each_leaf_rt_rq(rt_rq, cpu_rq(cpu)) + for_each_rt_rq(rt_rq, iter, cpu_rq(cpu)) print_rt_rq(m, cpu, rt_rq); rcu_read_unlock(); } diff --git a/kernel/sched_stoptask.c b/kernel/sched_stoptask.c index 1ba2bd40fdac..6f437632afab 100644 --- a/kernel/sched_stoptask.c +++ b/kernel/sched_stoptask.c @@ -9,8 +9,7 @@ #ifdef CONFIG_SMP static int -select_task_rq_stop(struct rq *rq, struct task_struct *p, - int sd_flag, int flags) +select_task_rq_stop(struct task_struct *p, int sd_flag, int flags) { return task_cpu(p); /* stop tasks as never migrate */ } @@ -26,7 +25,7 @@ static struct task_struct *pick_next_task_stop(struct rq *rq) { struct task_struct *stop = rq->stop; - if (stop && stop->se.on_rq) + if (stop && stop->on_rq) return stop; return NULL; diff --git a/kernel/softirq.c b/kernel/softirq.c index 174f976c2874..13960170cad4 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -58,7 +58,7 @@ DEFINE_PER_CPU(struct task_struct *, ksoftirqd); char *softirq_to_name[NR_SOFTIRQS] = { "HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "BLOCK_IOPOLL", - "TASKLET", "SCHED", "HRTIMER", "RCU" + "TASKLET", "SCHED", "HRTIMER" }; /* diff --git a/kernel/sys.c b/kernel/sys.c index af468edf096a..e4128b278f23 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -314,8 +314,8 @@ void kernel_restart_prepare(char *cmd) { blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); system_state = SYSTEM_RESTART; + usermodehelper_disable(); device_shutdown(); - sysdev_shutdown(); syscore_shutdown(); } @@ -344,6 +344,7 @@ static void kernel_shutdown_prepare(enum system_states state) blocking_notifier_call_chain(&reboot_notifier_list, (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); system_state = state; + usermodehelper_disable(); device_shutdown(); } /** @@ -354,7 +355,6 @@ static void kernel_shutdown_prepare(enum system_states state) void kernel_halt(void) { kernel_shutdown_prepare(SYSTEM_HALT); - sysdev_shutdown(); syscore_shutdown(); printk(KERN_EMERG "System halted.\n"); kmsg_dump(KMSG_DUMP_HALT); @@ -374,7 +374,6 @@ void kernel_power_off(void) if (pm_power_off_prepare) pm_power_off_prepare(); disable_nonboot_cpus(); - sysdev_shutdown(); syscore_shutdown(); printk(KERN_EMERG "Power down.\n"); kmsg_dump(KMSG_DUMP_POWEROFF); diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 0d74b9ba90c8..c027d4f602f1 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -194,6 +194,70 @@ void clockevents_register_device(struct clock_event_device *dev) } EXPORT_SYMBOL_GPL(clockevents_register_device); +static void clockevents_config(struct clock_event_device *dev, + u32 freq) +{ + u64 sec; + + if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT)) + return; + + /* + * Calculate the maximum number of seconds we can sleep. Limit + * to 10 minutes for hardware which can program more than + * 32bit ticks so we still get reasonable conversion values. + */ + sec = dev->max_delta_ticks; + do_div(sec, freq); + if (!sec) + sec = 1; + else if (sec > 600 && dev->max_delta_ticks > UINT_MAX) + sec = 600; + + clockevents_calc_mult_shift(dev, freq, sec); + dev->min_delta_ns = clockevent_delta2ns(dev->min_delta_ticks, dev); + dev->max_delta_ns = clockevent_delta2ns(dev->max_delta_ticks, dev); +} + +/** + * clockevents_config_and_register - Configure and register a clock event device + * @dev: device to register + * @freq: The clock frequency + * @min_delta: The minimum clock ticks to program in oneshot mode + * @max_delta: The maximum clock ticks to program in oneshot mode + * + * min/max_delta can be 0 for devices which do not support oneshot mode. + */ +void clockevents_config_and_register(struct clock_event_device *dev, + u32 freq, unsigned long min_delta, + unsigned long max_delta) +{ + dev->min_delta_ticks = min_delta; + dev->max_delta_ticks = max_delta; + clockevents_config(dev, freq); + clockevents_register_device(dev); +} + +/** + * clockevents_update_freq - Update frequency and reprogram a clock event device. + * @dev: device to modify + * @freq: new device frequency + * + * Reconfigure and reprogram a clock event device in oneshot + * mode. Must be called on the cpu for which the device delivers per + * cpu timer events with interrupts disabled! Returns 0 on success, + * -ETIME when the event is in the past. + */ +int clockevents_update_freq(struct clock_event_device *dev, u32 freq) +{ + clockevents_config(dev, freq); + + if (dev->mode != CLOCK_EVT_MODE_ONESHOT) + return 0; + + return clockevents_program_event(dev, dev->next_event, ktime_get()); +} + /* * Noop handler when we shut down an event device */ diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 6519cf62d9cd..1c95fd677328 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -626,19 +626,6 @@ static void clocksource_enqueue(struct clocksource *cs) list_add(&cs->list, entry); } - -/* - * Maximum time we expect to go between ticks. This includes idle - * tickless time. It provides the trade off between selecting a - * mult/shift pair that is very precise but can only handle a short - * period of time, vs. a mult/shift pair that can handle long periods - * of time but isn't as precise. - * - * This is a subsystem constant, and actual hardware limitations - * may override it (ie: clocksources that wrap every 3 seconds). - */ -#define MAX_UPDATE_LENGTH 5 /* Seconds */ - /** * __clocksource_updatefreq_scale - Used update clocksource with new freq * @t: clocksource to be registered @@ -652,15 +639,28 @@ static void clocksource_enqueue(struct clocksource *cs) */ void __clocksource_updatefreq_scale(struct clocksource *cs, u32 scale, u32 freq) { + u64 sec; + /* - * Ideally we want to use some of the limits used in - * clocksource_max_deferment, to provide a more informed - * MAX_UPDATE_LENGTH. But for now this just gets the - * register interface working properly. + * Calc the maximum number of seconds which we can run before + * wrapping around. For clocksources which have a mask > 32bit + * we need to limit the max sleep time to have a good + * conversion precision. 10 minutes is still a reasonable + * amount. That results in a shift value of 24 for a + * clocksource with mask >= 40bit and f >= 4GHz. That maps to + * ~ 0.06ppm granularity for NTP. We apply the same 12.5% + * margin as we do in clocksource_max_deferment() */ + sec = (cs->mask - (cs->mask >> 5)); + do_div(sec, freq); + do_div(sec, scale); + if (!sec) + sec = 1; + else if (sec > 600 && cs->mask > UINT_MAX) + sec = 600; + clocks_calc_mult_shift(&cs->mult, &cs->shift, freq, - NSEC_PER_SEC/scale, - MAX_UPDATE_LENGTH*scale); + NSEC_PER_SEC / scale, sec * scale); cs->max_idle_ns = clocksource_max_deferment(cs); } EXPORT_SYMBOL_GPL(__clocksource_updatefreq_scale); @@ -685,8 +685,8 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq) /* Add clocksource to the clcoksource list */ mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); - clocksource_select(); clocksource_enqueue_watchdog(cs); + clocksource_select(); mutex_unlock(&clocksource_mutex); return 0; } @@ -706,8 +706,8 @@ int clocksource_register(struct clocksource *cs) mutex_lock(&clocksource_mutex); clocksource_enqueue(cs); - clocksource_select(); clocksource_enqueue_watchdog(cs); + clocksource_select(); mutex_unlock(&clocksource_mutex); return 0; } diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 827e0f862da4..c7218d132738 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -524,10 +524,11 @@ static void tick_broadcast_init_next_event(struct cpumask *mask, */ void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { + int cpu = smp_processor_id(); + /* Set it up only once ! */ if (bc->event_handler != tick_handle_oneshot_broadcast) { int was_periodic = bc->mode == CLOCK_EVT_MODE_PERIODIC; - int cpu = smp_processor_id(); bc->event_handler = tick_handle_oneshot_broadcast; clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT); @@ -553,6 +554,15 @@ void tick_broadcast_setup_oneshot(struct clock_event_device *bc) tick_broadcast_set_event(tick_next_period, 1); } else bc->next_event.tv64 = KTIME_MAX; + } else { + /* + * The first cpu which switches to oneshot mode sets + * the bit for all other cpus which are in the general + * (periodic) broadcast mask. So the bit is set and + * would prevent the first broadcast enter after this + * to program the bc device. + */ + tick_broadcast_clear_oneshot(cpu); } } diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index ee24fa1935ac..d017c2c82c44 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -39,20 +39,26 @@ #include "trace_stat.h" #define FTRACE_WARN_ON(cond) \ - do { \ - if (WARN_ON(cond)) \ + ({ \ + int ___r = cond; \ + if (WARN_ON(___r)) \ ftrace_kill(); \ - } while (0) + ___r; \ + }) #define FTRACE_WARN_ON_ONCE(cond) \ - do { \ - if (WARN_ON_ONCE(cond)) \ + ({ \ + int ___r = cond; \ + if (WARN_ON_ONCE(___r)) \ ftrace_kill(); \ - } while (0) + ___r; \ + }) /* hash bits for specific function selection */ #define FTRACE_HASH_BITS 7 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) +#define FTRACE_HASH_DEFAULT_BITS 10 +#define FTRACE_HASH_MAX_BITS 12 /* ftrace_enabled is a method to turn ftrace on or off */ int ftrace_enabled __read_mostly; @@ -81,23 +87,29 @@ static struct ftrace_ops ftrace_list_end __read_mostly = .func = ftrace_stub, }; -static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; +static struct ftrace_ops *ftrace_global_list __read_mostly = &ftrace_list_end; +static struct ftrace_ops *ftrace_ops_list __read_mostly = &ftrace_list_end; ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; +static struct ftrace_ops global_ops; + +static void +ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); /* - * Traverse the ftrace_list, invoking all entries. The reason that we + * 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_list. + * concurrent insertions into the ftrace_global_list. * * Silly Alpha and silly pointer-speculation compiler optimizations! */ -static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) +static void ftrace_global_list_func(unsigned long ip, + unsigned long parent_ip) { - struct ftrace_ops *op = rcu_dereference_raw(ftrace_list); /*see above*/ + struct ftrace_ops *op = rcu_dereference_raw(ftrace_global_list); /*see above*/ while (op != &ftrace_list_end) { op->func(ip, parent_ip); @@ -147,46 +159,69 @@ static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) } #endif -static int __register_ftrace_function(struct ftrace_ops *ops) +static void update_global_ops(void) { - ops->next = ftrace_list; + ftrace_func_t func; + /* - * We are entering ops into the ftrace_list but another - * CPU might be walking that list. We need to make sure - * the ops->next pointer is valid before another CPU sees - * the ops pointer included into the ftrace_list. + * If there's only one function registered, then call that + * function directly. Otherwise, we need to iterate over the + * registered callers. */ - rcu_assign_pointer(ftrace_list, ops); + if (ftrace_global_list == &ftrace_list_end || + ftrace_global_list->next == &ftrace_list_end) + func = ftrace_global_list->func; + else + func = ftrace_global_list_func; - if (ftrace_enabled) { - ftrace_func_t func; + /* If we filter on pids, update to use the pid function */ + if (!list_empty(&ftrace_pids)) { + set_ftrace_pid_function(func); + func = ftrace_pid_func; + } - if (ops->next == &ftrace_list_end) - func = ops->func; - else - func = ftrace_list_func; + global_ops.func = func; +} - if (!list_empty(&ftrace_pids)) { - set_ftrace_pid_function(func); - func = ftrace_pid_func; - } +static void update_ftrace_function(void) +{ + ftrace_func_t func; + + update_global_ops(); + + /* + * If we are at the end of the list and this ops is + * not dynamic, then have the mcount trampoline call + * the function directly + */ + if (ftrace_ops_list == &ftrace_list_end || + (ftrace_ops_list->next == &ftrace_list_end && + !(ftrace_ops_list->flags & FTRACE_OPS_FL_DYNAMIC))) + func = ftrace_ops_list->func; + else + func = ftrace_ops_list_func; - /* - * For one func, simply call it directly. - * For more than one func, call the chain. - */ #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST - ftrace_trace_function = func; + ftrace_trace_function = func; #else - __ftrace_trace_function = func; - ftrace_trace_function = ftrace_test_stop_func; + __ftrace_trace_function = func; + ftrace_trace_function = ftrace_test_stop_func; #endif - } +} - return 0; +static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) +{ + ops->next = *list; + /* + * We are entering ops into the list but another + * CPU might be walking that list. We need to make sure + * the ops->next pointer is valid before another CPU sees + * the ops pointer included into the list. + */ + rcu_assign_pointer(*list, ops); } -static int __unregister_ftrace_function(struct ftrace_ops *ops) +static int remove_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) { struct ftrace_ops **p; @@ -194,13 +229,12 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) * If we are removing the last function, then simply point * to the ftrace_stub. */ - if (ftrace_list == ops && ops->next == &ftrace_list_end) { - ftrace_trace_function = ftrace_stub; - ftrace_list = &ftrace_list_end; + if (*list == ops && ops->next == &ftrace_list_end) { + *list = &ftrace_list_end; return 0; } - for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) + for (p = list; *p != &ftrace_list_end; p = &(*p)->next) if (*p == ops) break; @@ -208,53 +242,83 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) return -1; *p = (*p)->next; + return 0; +} - if (ftrace_enabled) { - /* If we only have one func left, then call that directly */ - if (ftrace_list->next == &ftrace_list_end) { - ftrace_func_t func = ftrace_list->func; +static int __register_ftrace_function(struct ftrace_ops *ops) +{ + if (ftrace_disabled) + return -ENODEV; - if (!list_empty(&ftrace_pids)) { - set_ftrace_pid_function(func); - func = ftrace_pid_func; - } -#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST - ftrace_trace_function = func; -#else - __ftrace_trace_function = func; -#endif - } - } + if (FTRACE_WARN_ON(ops == &global_ops)) + return -EINVAL; + + if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED)) + return -EBUSY; + + if (!core_kernel_data((unsigned long)ops)) + ops->flags |= FTRACE_OPS_FL_DYNAMIC; + + if (ops->flags & FTRACE_OPS_FL_GLOBAL) { + int first = ftrace_global_list == &ftrace_list_end; + add_ftrace_ops(&ftrace_global_list, ops); + ops->flags |= FTRACE_OPS_FL_ENABLED; + if (first) + add_ftrace_ops(&ftrace_ops_list, &global_ops); + } else + add_ftrace_ops(&ftrace_ops_list, ops); + + if (ftrace_enabled) + update_ftrace_function(); return 0; } -static void ftrace_update_pid_func(void) +static int __unregister_ftrace_function(struct ftrace_ops *ops) { - ftrace_func_t func; + int ret; - if (ftrace_trace_function == ftrace_stub) - return; + if (ftrace_disabled) + return -ENODEV; -#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST - func = ftrace_trace_function; -#else - func = __ftrace_trace_function; -#endif + if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED))) + return -EBUSY; - if (!list_empty(&ftrace_pids)) { - set_ftrace_pid_function(func); - func = ftrace_pid_func; - } else { - if (func == ftrace_pid_func) - func = ftrace_pid_function; - } + if (FTRACE_WARN_ON(ops == &global_ops)) + return -EINVAL; -#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST - ftrace_trace_function = func; -#else - __ftrace_trace_function = func; -#endif + if (ops->flags & FTRACE_OPS_FL_GLOBAL) { + ret = remove_ftrace_ops(&ftrace_global_list, ops); + if (!ret && ftrace_global_list == &ftrace_list_end) + ret = remove_ftrace_ops(&ftrace_ops_list, &global_ops); + if (!ret) + ops->flags &= ~FTRACE_OPS_FL_ENABLED; + } else + ret = remove_ftrace_ops(&ftrace_ops_list, ops); + + if (ret < 0) + return ret; + + if (ftrace_enabled) + update_ftrace_function(); + + /* + * Dynamic ops may be freed, we must make sure that all + * callers are done before leaving this function. + */ + if (ops->flags & FTRACE_OPS_FL_DYNAMIC) + synchronize_sched(); + + return 0; +} + +static void ftrace_update_pid_func(void) +{ + /* Only do something if we are tracing something */ + if (ftrace_trace_function == ftrace_stub) + return; + + update_ftrace_function(); } #ifdef CONFIG_FUNCTION_PROFILER @@ -888,8 +952,35 @@ enum { FTRACE_START_FUNC_RET = (1 << 3), FTRACE_STOP_FUNC_RET = (1 << 4), }; +struct ftrace_func_entry { + struct hlist_node hlist; + unsigned long ip; +}; -static int ftrace_filtered; +struct ftrace_hash { + unsigned long size_bits; + struct hlist_head *buckets; + unsigned long count; + struct rcu_head rcu; +}; + +/* + * We make these constant because no one should touch them, + * but they are used as the default "empty hash", to avoid allocating + * it all the time. These are in a read only section such that if + * anyone does try to modify it, it will cause an exception. + */ +static const struct hlist_head empty_buckets[1]; +static const struct ftrace_hash empty_hash = { + .buckets = (struct hlist_head *)empty_buckets, +}; +#define EMPTY_HASH ((struct ftrace_hash *)&empty_hash) + +static struct ftrace_ops global_ops = { + .func = ftrace_stub, + .notrace_hash = EMPTY_HASH, + .filter_hash = EMPTY_HASH, +}; static struct dyn_ftrace *ftrace_new_addrs; @@ -912,6 +1003,269 @@ static struct ftrace_page *ftrace_pages; static struct dyn_ftrace *ftrace_free_records; +static struct ftrace_func_entry * +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 (!hash->count) + return NULL; + + if (hash->size_bits > 0) + key = hash_long(ip, hash->size_bits); + else + key = 0; + + hhd = &hash->buckets[key]; + + hlist_for_each_entry_rcu(entry, n, hhd, hlist) { + if (entry->ip == ip) + return entry; + } + return NULL; +} + +static void __add_hash_entry(struct ftrace_hash *hash, + struct ftrace_func_entry *entry) +{ + struct hlist_head *hhd; + unsigned long key; + + if (hash->size_bits) + key = hash_long(entry->ip, hash->size_bits); + else + key = 0; + + hhd = &hash->buckets[key]; + hlist_add_head(&entry->hlist, hhd); + hash->count++; +} + +static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip) +{ + struct ftrace_func_entry *entry; + + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + + entry->ip = ip; + __add_hash_entry(hash, entry); + + return 0; +} + +static void +free_hash_entry(struct ftrace_hash *hash, + struct ftrace_func_entry *entry) +{ + hlist_del(&entry->hlist); + kfree(entry); + hash->count--; +} + +static void +remove_hash_entry(struct ftrace_hash *hash, + struct ftrace_func_entry *entry) +{ + hlist_del(&entry->hlist); + hash->count--; +} + +static void ftrace_hash_clear(struct ftrace_hash *hash) +{ + struct hlist_head *hhd; + struct hlist_node *tp, *tn; + struct ftrace_func_entry *entry; + int size = 1 << hash->size_bits; + int i; + + if (!hash->count) + return; + + for (i = 0; i < size; i++) { + hhd = &hash->buckets[i]; + hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist) + free_hash_entry(hash, entry); + } + FTRACE_WARN_ON(hash->count); +} + +static void free_ftrace_hash(struct ftrace_hash *hash) +{ + if (!hash || hash == EMPTY_HASH) + return; + ftrace_hash_clear(hash); + kfree(hash->buckets); + kfree(hash); +} + +static void __free_ftrace_hash_rcu(struct rcu_head *rcu) +{ + struct ftrace_hash *hash; + + hash = container_of(rcu, struct ftrace_hash, rcu); + free_ftrace_hash(hash); +} + +static void free_ftrace_hash_rcu(struct ftrace_hash *hash) +{ + if (!hash || hash == EMPTY_HASH) + return; + call_rcu_sched(&hash->rcu, __free_ftrace_hash_rcu); +} + +static struct ftrace_hash *alloc_ftrace_hash(int size_bits) +{ + struct ftrace_hash *hash; + int size; + + hash = kzalloc(sizeof(*hash), GFP_KERNEL); + if (!hash) + return NULL; + + size = 1 << size_bits; + hash->buckets = kzalloc(sizeof(*hash->buckets) * size, GFP_KERNEL); + + if (!hash->buckets) { + kfree(hash); + return NULL; + } + + hash->size_bits = size_bits; + + return hash; +} + +static struct ftrace_hash * +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; + + new_hash = alloc_ftrace_hash(size_bits); + if (!new_hash) + return NULL; + + /* Empty hash? */ + if (!hash || !hash->count) + return new_hash; + + size = 1 << hash->size_bits; + for (i = 0; i < size; i++) { + hlist_for_each_entry(entry, tp, &hash->buckets[i], hlist) { + ret = add_hash_entry(new_hash, entry->ip); + if (ret < 0) + goto free_hash; + } + } + + FTRACE_WARN_ON(new_hash->count != hash->count); + + return new_hash; + + free_hash: + free_ftrace_hash(new_hash); + return NULL; +} + +static int +ftrace_hash_move(struct ftrace_hash **dst, struct ftrace_hash *src) +{ + struct ftrace_func_entry *entry; + struct hlist_node *tp, *tn; + struct hlist_head *hhd; + struct ftrace_hash *old_hash; + struct ftrace_hash *new_hash; + unsigned long key; + int size = src->count; + int bits = 0; + int i; + + /* + * If the new source is empty, just free dst and assign it + * the empty_hash. + */ + if (!src->count) { + free_ftrace_hash_rcu(*dst); + rcu_assign_pointer(*dst, EMPTY_HASH); + return 0; + } + + /* + * Make the hash size about 1/2 the # found + */ + for (size /= 2; size; size >>= 1) + bits++; + + /* Don't allocate too much */ + if (bits > FTRACE_HASH_MAX_BITS) + bits = FTRACE_HASH_MAX_BITS; + + new_hash = alloc_ftrace_hash(bits); + if (!new_hash) + return -ENOMEM; + + 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) { + if (bits > 0) + key = hash_long(entry->ip, bits); + else + key = 0; + remove_hash_entry(src, entry); + __add_hash_entry(new_hash, entry); + } + } + + old_hash = *dst; + rcu_assign_pointer(*dst, new_hash); + free_ftrace_hash_rcu(old_hash); + + return 0; +} + +/* + * Test the hashes for this ops to see if we want to call + * the ops->func or not. + * + * It's a match if the ip is in the ops->filter_hash or + * the filter_hash does not exist or is empty, + * AND + * the ip is not in the ops->notrace_hash. + * + * This needs to be called with preemption disabled as + * the hashes are freed with call_rcu_sched(). + */ +static int +ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) +{ + struct ftrace_hash *filter_hash; + struct ftrace_hash *notrace_hash; + int ret; + + filter_hash = rcu_dereference_raw(ops->filter_hash); + notrace_hash = rcu_dereference_raw(ops->notrace_hash); + + if ((!filter_hash || !filter_hash->count || + ftrace_lookup_ip(filter_hash, ip)) && + (!notrace_hash || !notrace_hash->count || + !ftrace_lookup_ip(notrace_hash, ip))) + ret = 1; + else + ret = 0; + + return ret; +} + /* * This is a double for. Do not use 'break' to break out of the loop, * you must use a goto. @@ -926,6 +1280,105 @@ static struct dyn_ftrace *ftrace_free_records; } \ } +static void __ftrace_hash_rec_update(struct ftrace_ops *ops, + int filter_hash, + bool inc) +{ + struct ftrace_hash *hash; + struct ftrace_hash *other_hash; + struct ftrace_page *pg; + struct dyn_ftrace *rec; + int count = 0; + int all = 0; + + /* Only update if the ops has been registered */ + if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) + return; + + /* + * In the filter_hash case: + * If the count is zero, we update all records. + * Otherwise we just update the items in the hash. + * + * In the notrace_hash case: + * We enable the update in the hash. + * As disabling notrace means enabling the tracing, + * and enabling notrace means disabling, the inc variable + * gets inversed. + */ + if (filter_hash) { + hash = ops->filter_hash; + other_hash = ops->notrace_hash; + if (!hash || !hash->count) + all = 1; + } else { + inc = !inc; + hash = ops->notrace_hash; + other_hash = ops->filter_hash; + /* + * If the notrace hash has no items, + * then there's nothing to do. + */ + if (hash && !hash->count) + return; + } + + do_for_each_ftrace_rec(pg, rec) { + int in_other_hash = 0; + int in_hash = 0; + int match = 0; + + if (all) { + /* + * Only the filter_hash affects all records. + * Update if the record is not in the notrace hash. + */ + if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip)) + match = 1; + } else { + in_hash = hash && !!ftrace_lookup_ip(hash, rec->ip); + in_other_hash = other_hash && !!ftrace_lookup_ip(other_hash, rec->ip); + + /* + * + */ + if (filter_hash && in_hash && !in_other_hash) + match = 1; + else if (!filter_hash && in_hash && + (in_other_hash || !other_hash->count)) + match = 1; + } + if (!match) + continue; + + if (inc) { + rec->flags++; + if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == FTRACE_REF_MAX)) + return; + } else { + if (FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) + return; + rec->flags--; + } + count++; + /* Shortcut, if we handled all records, we are done. */ + if (!all && count == hash->count) + return; + } while_for_each_ftrace_rec(); +} + +static void ftrace_hash_rec_disable(struct ftrace_ops *ops, + int filter_hash) +{ + __ftrace_hash_rec_update(ops, filter_hash, 0); +} + +static void ftrace_hash_rec_enable(struct ftrace_ops *ops, + int filter_hash) +{ + __ftrace_hash_rec_update(ops, filter_hash, 1); +} + static void ftrace_free_rec(struct dyn_ftrace *rec) { rec->freelist = ftrace_free_records; @@ -1047,18 +1500,18 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable) ftrace_addr = (unsigned long)FTRACE_ADDR; /* - * If this record is not to be traced or we want to disable it, - * then disable it. + * If we are enabling tracing: + * + * If the record has a ref count, then we need to enable it + * because someone is using it. * - * If we want to enable it and filtering is off, then enable it. + * Otherwise we make sure its disabled. * - * If we want to enable it and filtering is on, enable it only if - * it's filtered + * If we are disabling tracing, then disable all records that + * are enabled. */ - if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) { - if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER)) - flag = FTRACE_FL_ENABLED; - } + if (enable && (rec->flags & ~FTRACE_FL_MASK)) + flag = FTRACE_FL_ENABLED; /* If the state of this record hasn't changed, then do nothing */ if ((rec->flags & FTRACE_FL_ENABLED) == flag) @@ -1079,19 +1532,16 @@ static void ftrace_replace_code(int enable) struct ftrace_page *pg; int failed; + if (unlikely(ftrace_disabled)) + return; + do_for_each_ftrace_rec(pg, rec) { - /* - * Skip over free records, records that have - * failed and not converted. - */ - if (rec->flags & FTRACE_FL_FREE || - rec->flags & FTRACE_FL_FAILED || - !(rec->flags & FTRACE_FL_CONVERTED)) + /* Skip over free records */ + if (rec->flags & FTRACE_FL_FREE) continue; failed = __ftrace_replace_code(rec, enable); if (failed) { - rec->flags |= FTRACE_FL_FAILED; ftrace_bug(failed, rec->ip); /* Stop processing */ return; @@ -1107,10 +1557,12 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) ip = rec->ip; + if (unlikely(ftrace_disabled)) + return 0; + ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); if (ret) { ftrace_bug(ret, ip); - rec->flags |= FTRACE_FL_FAILED; return 0; } return 1; @@ -1171,6 +1623,7 @@ static void ftrace_run_update_code(int command) static ftrace_func_t saved_ftrace_func; static int ftrace_start_up; +static int global_start_up; static void ftrace_startup_enable(int command) { @@ -1185,19 +1638,36 @@ static void ftrace_startup_enable(int command) ftrace_run_update_code(command); } -static void ftrace_startup(int command) +static void ftrace_startup(struct ftrace_ops *ops, int command) { + bool hash_enable = true; + if (unlikely(ftrace_disabled)) return; ftrace_start_up++; command |= FTRACE_ENABLE_CALLS; + /* ops marked global share the filter hashes */ + if (ops->flags & FTRACE_OPS_FL_GLOBAL) { + ops = &global_ops; + /* Don't update hash if global is already set */ + if (global_start_up) + hash_enable = false; + global_start_up++; + } + + ops->flags |= FTRACE_OPS_FL_ENABLED; + if (hash_enable) + ftrace_hash_rec_enable(ops, 1); + ftrace_startup_enable(command); } -static void ftrace_shutdown(int command) +static void ftrace_shutdown(struct ftrace_ops *ops, int command) { + bool hash_disable = true; + if (unlikely(ftrace_disabled)) return; @@ -1209,6 +1679,23 @@ static void ftrace_shutdown(int command) */ WARN_ON_ONCE(ftrace_start_up < 0); + if (ops->flags & FTRACE_OPS_FL_GLOBAL) { + ops = &global_ops; + global_start_up--; + WARN_ON_ONCE(global_start_up < 0); + /* Don't update hash if global still has users */ + if (global_start_up) { + WARN_ON_ONCE(!ftrace_start_up); + hash_disable = false; + } + } + + if (hash_disable) + ftrace_hash_rec_disable(ops, 1); + + if (ops != &global_ops || !global_start_up) + ops->flags &= ~FTRACE_OPS_FL_ENABLED; + if (!ftrace_start_up) command |= FTRACE_DISABLE_CALLS; @@ -1273,10 +1760,10 @@ static int ftrace_update_code(struct module *mod) */ if (!ftrace_code_disable(mod, p)) { ftrace_free_rec(p); - continue; + /* Game over */ + break; } - p->flags |= FTRACE_FL_CONVERTED; ftrace_update_cnt++; /* @@ -1351,9 +1838,9 @@ static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) enum { FTRACE_ITER_FILTER = (1 << 0), FTRACE_ITER_NOTRACE = (1 << 1), - FTRACE_ITER_FAILURES = (1 << 2), - FTRACE_ITER_PRINTALL = (1 << 3), - FTRACE_ITER_HASH = (1 << 4), + FTRACE_ITER_PRINTALL = (1 << 2), + FTRACE_ITER_HASH = (1 << 3), + FTRACE_ITER_ENABLED = (1 << 4), }; #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ @@ -1365,6 +1852,8 @@ struct ftrace_iterator { struct dyn_ftrace *func; struct ftrace_func_probe *probe; struct trace_parser parser; + struct ftrace_hash *hash; + struct ftrace_ops *ops; int hidx; int idx; unsigned flags; @@ -1461,8 +1950,12 @@ static void * t_next(struct seq_file *m, void *v, loff_t *pos) { struct ftrace_iterator *iter = m->private; + struct ftrace_ops *ops = &global_ops; struct dyn_ftrace *rec = NULL; + if (unlikely(ftrace_disabled)) + return NULL; + if (iter->flags & FTRACE_ITER_HASH) return t_hash_next(m, pos); @@ -1483,17 +1976,15 @@ t_next(struct seq_file *m, void *v, loff_t *pos) rec = &iter->pg->records[iter->idx++]; if ((rec->flags & FTRACE_FL_FREE) || - (!(iter->flags & FTRACE_ITER_FAILURES) && - (rec->flags & FTRACE_FL_FAILED)) || - - ((iter->flags & FTRACE_ITER_FAILURES) && - !(rec->flags & FTRACE_FL_FAILED)) || - ((iter->flags & FTRACE_ITER_FILTER) && - !(rec->flags & FTRACE_FL_FILTER)) || + !(ftrace_lookup_ip(ops->filter_hash, rec->ip))) || ((iter->flags & FTRACE_ITER_NOTRACE) && - !(rec->flags & FTRACE_FL_NOTRACE))) { + !ftrace_lookup_ip(ops->notrace_hash, rec->ip)) || + + ((iter->flags & FTRACE_ITER_ENABLED) && + !(rec->flags & ~FTRACE_FL_MASK))) { + rec = NULL; goto retry; } @@ -1517,10 +2008,15 @@ static void reset_iter_read(struct ftrace_iterator *iter) static void *t_start(struct seq_file *m, loff_t *pos) { struct ftrace_iterator *iter = m->private; + struct ftrace_ops *ops = &global_ops; void *p = NULL; loff_t l; mutex_lock(&ftrace_lock); + + if (unlikely(ftrace_disabled)) + return NULL; + /* * If an lseek was done, then reset and start from beginning. */ @@ -1532,7 +2028,7 @@ static void *t_start(struct seq_file *m, loff_t *pos) * off, we can short cut and just print out that all * functions are enabled. */ - if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { + if (iter->flags & FTRACE_ITER_FILTER && !ops->filter_hash->count) { if (*pos > 0) return t_hash_start(m, pos); iter->flags |= FTRACE_ITER_PRINTALL; @@ -1590,7 +2086,11 @@ static int t_show(struct seq_file *m, void *v) if (!rec) return 0; - seq_printf(m, "%ps\n", (void *)rec->ip); + seq_printf(m, "%ps", (void *)rec->ip); + if (iter->flags & FTRACE_ITER_ENABLED) + seq_printf(m, " (%ld)", + rec->flags & ~FTRACE_FL_MASK); + seq_printf(m, "\n"); return 0; } @@ -1630,44 +2130,46 @@ ftrace_avail_open(struct inode *inode, struct file *file) } static int -ftrace_failures_open(struct inode *inode, struct file *file) +ftrace_enabled_open(struct inode *inode, struct file *file) { - int ret; - struct seq_file *m; struct ftrace_iterator *iter; + int ret; + + if (unlikely(ftrace_disabled)) + return -ENODEV; + + iter = kzalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) + return -ENOMEM; + + iter->pg = ftrace_pages_start; + iter->flags = FTRACE_ITER_ENABLED; - ret = ftrace_avail_open(inode, file); + ret = seq_open(file, &show_ftrace_seq_ops); if (!ret) { - m = file->private_data; - iter = m->private; - iter->flags = FTRACE_ITER_FAILURES; + struct seq_file *m = file->private_data; + + m->private = iter; + } else { + kfree(iter); } return ret; } - -static void ftrace_filter_reset(int enable) +static void ftrace_filter_reset(struct ftrace_hash *hash) { - struct ftrace_page *pg; - struct dyn_ftrace *rec; - unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; - mutex_lock(&ftrace_lock); - if (enable) - ftrace_filtered = 0; - do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & FTRACE_FL_FAILED) - continue; - rec->flags &= ~type; - } while_for_each_ftrace_rec(); + ftrace_hash_clear(hash); mutex_unlock(&ftrace_lock); } static int -ftrace_regex_open(struct inode *inode, struct file *file, int enable) +ftrace_regex_open(struct ftrace_ops *ops, int flag, + struct inode *inode, struct file *file) { struct ftrace_iterator *iter; + struct ftrace_hash *hash; int ret = 0; if (unlikely(ftrace_disabled)) @@ -1682,21 +2184,42 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable) return -ENOMEM; } + if (flag & FTRACE_ITER_NOTRACE) + hash = ops->notrace_hash; + else + hash = ops->filter_hash; + + iter->ops = ops; + iter->flags = flag; + + if (file->f_mode & FMODE_WRITE) { + mutex_lock(&ftrace_lock); + iter->hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, hash); + mutex_unlock(&ftrace_lock); + + if (!iter->hash) { + trace_parser_put(&iter->parser); + kfree(iter); + return -ENOMEM; + } + } + mutex_lock(&ftrace_regex_lock); + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) - ftrace_filter_reset(enable); + ftrace_filter_reset(iter->hash); if (file->f_mode & FMODE_READ) { iter->pg = ftrace_pages_start; - iter->flags = enable ? FTRACE_ITER_FILTER : - FTRACE_ITER_NOTRACE; ret = seq_open(file, &show_ftrace_seq_ops); if (!ret) { struct seq_file *m = file->private_data; m->private = iter; } else { + /* Failed */ + free_ftrace_hash(iter->hash); trace_parser_put(&iter->parser); kfree(iter); } @@ -1710,13 +2233,15 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable) static int ftrace_filter_open(struct inode *inode, struct file *file) { - return ftrace_regex_open(inode, file, 1); + return ftrace_regex_open(&global_ops, FTRACE_ITER_FILTER, + inode, file); } static int ftrace_notrace_open(struct inode *inode, struct file *file) { - return ftrace_regex_open(inode, file, 0); + return ftrace_regex_open(&global_ops, FTRACE_ITER_NOTRACE, + inode, file); } static loff_t @@ -1761,86 +2286,99 @@ static int ftrace_match(char *str, char *regex, int len, int type) } static int -ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) +enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not) +{ + struct ftrace_func_entry *entry; + int ret = 0; + + entry = ftrace_lookup_ip(hash, rec->ip); + if (not) { + /* Do nothing if it doesn't exist */ + if (!entry) + return 0; + + free_hash_entry(hash, entry); + } else { + /* Do nothing if it exists */ + if (entry) + return 0; + + ret = add_hash_entry(hash, rec->ip); + } + return ret; +} + +static int +ftrace_match_record(struct dyn_ftrace *rec, char *mod, + char *regex, int len, int type) { char str[KSYM_SYMBOL_LEN]; + char *modname; + + kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); + + if (mod) { + /* module lookup requires matching the module */ + if (!modname || strcmp(modname, mod)) + return 0; + + /* blank search means to match all funcs in the mod */ + if (!len) + return 1; + } - kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); return ftrace_match(str, regex, len, type); } -static int ftrace_match_records(char *buff, int len, int enable) +static int +match_records(struct ftrace_hash *hash, char *buff, + int len, char *mod, int not) { - unsigned int search_len; + unsigned search_len = 0; struct ftrace_page *pg; struct dyn_ftrace *rec; - unsigned long flag; - char *search; - int type; - int not; + int type = MATCH_FULL; + char *search = buff; int found = 0; + int ret; - flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; - type = filter_parse_regex(buff, len, &search, ¬); - - search_len = strlen(search); + if (len) { + type = filter_parse_regex(buff, len, &search, ¬); + search_len = strlen(search); + } mutex_lock(&ftrace_lock); - do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & FTRACE_FL_FAILED) - continue; + if (unlikely(ftrace_disabled)) + goto out_unlock; - if (ftrace_match_record(rec, search, search_len, type)) { - if (not) - rec->flags &= ~flag; - else - rec->flags |= flag; + do_for_each_ftrace_rec(pg, rec) { + + if (ftrace_match_record(rec, mod, search, search_len, type)) { + ret = enter_record(hash, rec, not); + if (ret < 0) { + found = ret; + goto out_unlock; + } found = 1; } - /* - * Only enable filtering if we have a function that - * is filtered on. - */ - if (enable && (rec->flags & FTRACE_FL_FILTER)) - ftrace_filtered = 1; } while_for_each_ftrace_rec(); + out_unlock: mutex_unlock(&ftrace_lock); return found; } static int -ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, - char *regex, int len, int type) +ftrace_match_records(struct ftrace_hash *hash, char *buff, int len) { - char str[KSYM_SYMBOL_LEN]; - char *modname; - - kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); - - if (!modname || strcmp(modname, mod)) - return 0; - - /* blank search means to match all funcs in the mod */ - if (len) - return ftrace_match(str, regex, len, type); - else - return 1; + return match_records(hash, buff, len, NULL, 0); } -static int ftrace_match_module_records(char *buff, char *mod, int enable) +static int +ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod) { - unsigned search_len = 0; - struct ftrace_page *pg; - struct dyn_ftrace *rec; - int type = MATCH_FULL; - char *search = buff; - unsigned long flag; int not = 0; - int found = 0; - - flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; /* blank or '*' mean the same */ if (strcmp(buff, "*") == 0) @@ -1852,32 +2390,7 @@ static int ftrace_match_module_records(char *buff, char *mod, int enable) not = 1; } - if (strlen(buff)) { - type = filter_parse_regex(buff, strlen(buff), &search, ¬); - search_len = strlen(search); - } - - mutex_lock(&ftrace_lock); - do_for_each_ftrace_rec(pg, rec) { - - if (rec->flags & FTRACE_FL_FAILED) - continue; - - if (ftrace_match_module_record(rec, mod, - search, search_len, type)) { - if (not) - rec->flags &= ~flag; - else - rec->flags |= flag; - found = 1; - } - if (enable && (rec->flags & FTRACE_FL_FILTER)) - ftrace_filtered = 1; - - } while_for_each_ftrace_rec(); - mutex_unlock(&ftrace_lock); - - return found; + return match_records(hash, buff, strlen(buff), mod, not); } /* @@ -1888,7 +2401,10 @@ static int ftrace_match_module_records(char *buff, char *mod, int enable) static int ftrace_mod_callback(char *func, char *cmd, char *param, int enable) { + struct ftrace_ops *ops = &global_ops; + struct ftrace_hash *hash; char *mod; + int ret = -EINVAL; /* * cmd == 'mod' because we only registered this func @@ -1900,15 +2416,24 @@ ftrace_mod_callback(char *func, char *cmd, char *param, int enable) /* we must have a module name */ if (!param) - return -EINVAL; + return ret; mod = strsep(¶m, ":"); if (!strlen(mod)) - return -EINVAL; + return ret; - if (ftrace_match_module_records(func, mod, enable)) - return 0; - return -EINVAL; + if (enable) + hash = ops->filter_hash; + else + hash = ops->notrace_hash; + + ret = ftrace_match_module_records(hash, func, mod); + if (!ret) + ret = -EINVAL; + if (ret < 0) + return ret; + + return 0; } static struct ftrace_func_command ftrace_mod_cmd = { @@ -1959,6 +2484,7 @@ static int ftrace_probe_registered; static void __enable_ftrace_function_probe(void) { + int ret; int i; if (ftrace_probe_registered) @@ -1973,13 +2499,16 @@ static void __enable_ftrace_function_probe(void) if (i == FTRACE_FUNC_HASHSIZE) return; - __register_ftrace_function(&trace_probe_ops); - ftrace_startup(0); + ret = __register_ftrace_function(&trace_probe_ops); + if (!ret) + ftrace_startup(&trace_probe_ops, 0); + ftrace_probe_registered = 1; } static void __disable_ftrace_function_probe(void) { + int ret; int i; if (!ftrace_probe_registered) @@ -1992,8 +2521,10 @@ static void __disable_ftrace_function_probe(void) } /* no more funcs left */ - __unregister_ftrace_function(&trace_probe_ops); - ftrace_shutdown(0); + ret = __unregister_ftrace_function(&trace_probe_ops); + if (!ret) + ftrace_shutdown(&trace_probe_ops, 0); + ftrace_probe_registered = 0; } @@ -2029,12 +2560,13 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, return -EINVAL; mutex_lock(&ftrace_lock); - do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & FTRACE_FL_FAILED) - continue; + if (unlikely(ftrace_disabled)) + goto out_unlock; + + do_for_each_ftrace_rec(pg, rec) { - if (!ftrace_match_record(rec, search, len, type)) + if (!ftrace_match_record(rec, NULL, search, len, type)) continue; entry = kmalloc(sizeof(*entry), GFP_KERNEL); @@ -2195,18 +2727,22 @@ int unregister_ftrace_command(struct ftrace_func_command *cmd) return ret; } -static int ftrace_process_regex(char *buff, int len, int enable) +static int ftrace_process_regex(struct ftrace_hash *hash, + char *buff, int len, int enable) { char *func, *command, *next = buff; struct ftrace_func_command *p; - int ret = -EINVAL; + int ret; func = strsep(&next, ":"); if (!next) { - if (ftrace_match_records(func, len, enable)) - return 0; - return ret; + ret = ftrace_match_records(hash, func, len); + if (!ret) + ret = -EINVAL; + if (ret < 0) + return ret; + return 0; } /* command found */ @@ -2239,6 +2775,10 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, mutex_lock(&ftrace_regex_lock); + ret = -ENODEV; + if (unlikely(ftrace_disabled)) + goto out_unlock; + if (file->f_mode & FMODE_READ) { struct seq_file *m = file->private_data; iter = m->private; @@ -2250,7 +2790,7 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, if (read >= 0 && trace_parser_loaded(parser) && !trace_parser_cont(parser)) { - ret = ftrace_process_regex(parser->buffer, + ret = ftrace_process_regex(iter->hash, parser->buffer, parser->idx, enable); trace_parser_clear(parser); if (ret) @@ -2278,22 +2818,49 @@ ftrace_notrace_write(struct file *file, const char __user *ubuf, return ftrace_regex_write(file, ubuf, cnt, ppos, 0); } -static void -ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) +static int +ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, + int reset, int enable) { + struct ftrace_hash **orig_hash; + struct ftrace_hash *hash; + int ret; + + /* All global ops uses the global ops filters */ + if (ops->flags & FTRACE_OPS_FL_GLOBAL) + ops = &global_ops; + if (unlikely(ftrace_disabled)) - return; + return -ENODEV; + + if (enable) + orig_hash = &ops->filter_hash; + else + orig_hash = &ops->notrace_hash; + + hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash); + if (!hash) + return -ENOMEM; mutex_lock(&ftrace_regex_lock); if (reset) - ftrace_filter_reset(enable); + ftrace_filter_reset(hash); if (buf) - ftrace_match_records(buf, len, enable); + ftrace_match_records(hash, buf, len); + + mutex_lock(&ftrace_lock); + ret = ftrace_hash_move(orig_hash, hash); + mutex_unlock(&ftrace_lock); + mutex_unlock(&ftrace_regex_lock); + + free_ftrace_hash(hash); + return ret; } /** * ftrace_set_filter - set a function to filter on in ftrace + * @ops - the ops to set the filter with * @buf - the string that holds the function filter text. * @len - the length of the string. * @reset - non zero to reset all filters before applying this filter. @@ -2301,13 +2868,16 @@ ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) * Filters denote which functions should be enabled when tracing is enabled. * If @buf is NULL and reset is set, all functions will be enabled for tracing. */ -void ftrace_set_filter(unsigned char *buf, int len, int reset) +void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf, + int len, int reset) { - ftrace_set_regex(buf, len, reset, 1); + ftrace_set_regex(ops, buf, len, reset, 1); } +EXPORT_SYMBOL_GPL(ftrace_set_filter); /** * ftrace_set_notrace - set a function to not trace in ftrace + * @ops - the ops to set the notrace filter with * @buf - the string that holds the function notrace text. * @len - the length of the string. * @reset - non zero to reset all filters before applying this filter. @@ -2316,10 +2886,44 @@ void ftrace_set_filter(unsigned char *buf, int len, int reset) * is enabled. If @buf is NULL and reset is set, all functions will be enabled * for tracing. */ -void ftrace_set_notrace(unsigned char *buf, int len, int reset) +void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, + int len, int reset) { - ftrace_set_regex(buf, len, reset, 0); + ftrace_set_regex(ops, buf, len, reset, 0); } +EXPORT_SYMBOL_GPL(ftrace_set_notrace); +/** + * ftrace_set_filter - set a function to filter on in ftrace + * @ops - the ops to set the filter with + * @buf - the string that holds the function filter text. + * @len - the length of the string. + * @reset - non zero to reset all filters before applying this filter. + * + * Filters denote which functions should be enabled when tracing is enabled. + * If @buf is NULL and reset is set, all functions will be enabled for tracing. + */ +void ftrace_set_global_filter(unsigned char *buf, int len, int reset) +{ + ftrace_set_regex(&global_ops, buf, len, reset, 1); +} +EXPORT_SYMBOL_GPL(ftrace_set_global_filter); + +/** + * ftrace_set_notrace - set a function to not trace in ftrace + * @ops - the ops to set the notrace filter with + * @buf - the string that holds the function notrace text. + * @len - the length of the string. + * @reset - non zero to reset all filters before applying this filter. + * + * Notrace Filters denote which functions should not be enabled when tracing + * is enabled. If @buf is NULL and reset is set, all functions will be enabled + * for tracing. + */ +void ftrace_set_global_notrace(unsigned char *buf, int len, int reset) +{ + ftrace_set_regex(&global_ops, buf, len, reset, 0); +} +EXPORT_SYMBOL_GPL(ftrace_set_global_notrace); /* * command line interface to allow users to set filters on boot up. @@ -2370,22 +2974,23 @@ static void __init set_ftrace_early_graph(char *buf) } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -static void __init set_ftrace_early_filter(char *buf, int enable) +static void __init +set_ftrace_early_filter(struct ftrace_ops *ops, char *buf, int enable) { char *func; while (buf) { func = strsep(&buf, ","); - ftrace_set_regex(func, strlen(func), 0, enable); + ftrace_set_regex(ops, func, strlen(func), 0, enable); } } static void __init set_ftrace_early_filters(void) { if (ftrace_filter_buf[0]) - set_ftrace_early_filter(ftrace_filter_buf, 1); + set_ftrace_early_filter(&global_ops, ftrace_filter_buf, 1); if (ftrace_notrace_buf[0]) - set_ftrace_early_filter(ftrace_notrace_buf, 0); + set_ftrace_early_filter(&global_ops, ftrace_notrace_buf, 0); #ifdef CONFIG_FUNCTION_GRAPH_TRACER if (ftrace_graph_buf[0]) set_ftrace_early_graph(ftrace_graph_buf); @@ -2393,11 +2998,14 @@ static void __init set_ftrace_early_filters(void) } static int -ftrace_regex_release(struct inode *inode, struct file *file, int enable) +ftrace_regex_release(struct inode *inode, struct file *file) { struct seq_file *m = (struct seq_file *)file->private_data; struct ftrace_iterator *iter; + struct ftrace_hash **orig_hash; struct trace_parser *parser; + int filter_hash; + int ret; mutex_lock(&ftrace_regex_lock); if (file->f_mode & FMODE_READ) { @@ -2410,33 +3018,41 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable) parser = &iter->parser; if (trace_parser_loaded(parser)) { parser->buffer[parser->idx] = 0; - ftrace_match_records(parser->buffer, parser->idx, enable); + ftrace_match_records(iter->hash, parser->buffer, parser->idx); } - mutex_lock(&ftrace_lock); - if (ftrace_start_up && ftrace_enabled) - ftrace_run_update_code(FTRACE_ENABLE_CALLS); - mutex_unlock(&ftrace_lock); - trace_parser_put(parser); + + if (file->f_mode & FMODE_WRITE) { + filter_hash = !!(iter->flags & FTRACE_ITER_FILTER); + + if (filter_hash) + orig_hash = &iter->ops->filter_hash; + else + orig_hash = &iter->ops->notrace_hash; + + mutex_lock(&ftrace_lock); + /* + * Remove the current set, update the hash and add + * them back. + */ + ftrace_hash_rec_disable(iter->ops, filter_hash); + ret = ftrace_hash_move(orig_hash, iter->hash); + if (!ret) { + ftrace_hash_rec_enable(iter->ops, filter_hash); + if (iter->ops->flags & FTRACE_OPS_FL_ENABLED + && ftrace_enabled) + ftrace_run_update_code(FTRACE_ENABLE_CALLS); + } + mutex_unlock(&ftrace_lock); + } + free_ftrace_hash(iter->hash); kfree(iter); mutex_unlock(&ftrace_regex_lock); return 0; } -static int -ftrace_filter_release(struct inode *inode, struct file *file) -{ - return ftrace_regex_release(inode, file, 1); -} - -static int -ftrace_notrace_release(struct inode *inode, struct file *file) -{ - return ftrace_regex_release(inode, file, 0); -} - static const struct file_operations ftrace_avail_fops = { .open = ftrace_avail_open, .read = seq_read, @@ -2444,8 +3060,8 @@ static const struct file_operations ftrace_avail_fops = { .release = seq_release_private, }; -static const struct file_operations ftrace_failures_fops = { - .open = ftrace_failures_open, +static const struct file_operations ftrace_enabled_fops = { + .open = ftrace_enabled_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release_private, @@ -2456,7 +3072,7 @@ static const struct file_operations ftrace_filter_fops = { .read = seq_read, .write = ftrace_filter_write, .llseek = ftrace_regex_lseek, - .release = ftrace_filter_release, + .release = ftrace_regex_release, }; static const struct file_operations ftrace_notrace_fops = { @@ -2464,7 +3080,7 @@ static const struct file_operations ftrace_notrace_fops = { .read = seq_read, .write = ftrace_notrace_write, .llseek = ftrace_regex_lseek, - .release = ftrace_notrace_release, + .release = ftrace_regex_release, }; #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -2573,9 +3189,6 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer) bool exists; int i; - if (ftrace_disabled) - return -ENODEV; - /* decode regex */ type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) @@ -2584,12 +3197,18 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer) search_len = strlen(search); mutex_lock(&ftrace_lock); + + if (unlikely(ftrace_disabled)) { + mutex_unlock(&ftrace_lock); + return -ENODEV; + } + do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) + if (rec->flags & FTRACE_FL_FREE) continue; - if (ftrace_match_record(rec, search, search_len, type)) { + if (ftrace_match_record(rec, NULL, search, search_len, type)) { /* if it is in the array */ exists = false; for (i = 0; i < *idx; i++) { @@ -2679,8 +3298,8 @@ static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) trace_create_file("available_filter_functions", 0444, d_tracer, NULL, &ftrace_avail_fops); - trace_create_file("failures", 0444, - d_tracer, NULL, &ftrace_failures_fops); + trace_create_file("enabled_functions", 0444, + d_tracer, NULL, &ftrace_enabled_fops); trace_create_file("set_ftrace_filter", 0644, d_tracer, NULL, &ftrace_filter_fops); @@ -2703,7 +3322,6 @@ static int ftrace_process_locs(struct module *mod, { unsigned long *p; unsigned long addr; - unsigned long flags; mutex_lock(&ftrace_lock); p = start; @@ -2720,10 +3338,7 @@ static int ftrace_process_locs(struct module *mod, ftrace_record_ip(addr); } - /* disable interrupts to prevent kstop machine */ - local_irq_save(flags); ftrace_update_code(mod); - local_irq_restore(flags); mutex_unlock(&ftrace_lock); return 0; @@ -2735,10 +3350,11 @@ void ftrace_release_mod(struct module *mod) struct dyn_ftrace *rec; struct ftrace_page *pg; + mutex_lock(&ftrace_lock); + if (ftrace_disabled) - return; + goto out_unlock; - mutex_lock(&ftrace_lock); do_for_each_ftrace_rec(pg, rec) { if (within_module_core(rec->ip, mod)) { /* @@ -2749,6 +3365,7 @@ void ftrace_release_mod(struct module *mod) ftrace_free_rec(rec); } } while_for_each_ftrace_rec(); + out_unlock: mutex_unlock(&ftrace_lock); } @@ -2835,6 +3452,10 @@ void __init ftrace_init(void) #else +static struct ftrace_ops global_ops = { + .func = ftrace_stub, +}; + static int __init ftrace_nodyn_init(void) { ftrace_enabled = 1; @@ -2845,12 +3466,38 @@ device_initcall(ftrace_nodyn_init); static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } static inline void ftrace_startup_enable(int command) { } /* Keep as macros so we do not need to define the commands */ -# define ftrace_startup(command) do { } while (0) -# define ftrace_shutdown(command) do { } while (0) +# define ftrace_startup(ops, command) do { } while (0) +# define ftrace_shutdown(ops, command) do { } while (0) # define ftrace_startup_sysctl() do { } while (0) # define ftrace_shutdown_sysctl() do { } while (0) + +static inline int +ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip) +{ + return 1; +} + #endif /* CONFIG_DYNAMIC_FTRACE */ +static void +ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip) +{ + struct ftrace_ops *op; + + /* + * 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) { + if (ftrace_ops_test(op, ip)) + op->func(ip, parent_ip); + op = rcu_dereference_raw(op->next); + }; + preempt_enable_notrace(); +} + static void clear_ftrace_swapper(void) { struct task_struct *p; @@ -3143,19 +3790,23 @@ void ftrace_kill(void) */ int register_ftrace_function(struct ftrace_ops *ops) { - int ret; - - if (unlikely(ftrace_disabled)) - return -1; + int ret = -1; mutex_lock(&ftrace_lock); + if (unlikely(ftrace_disabled)) + goto out_unlock; + ret = __register_ftrace_function(ops); - ftrace_startup(0); + if (!ret) + ftrace_startup(ops, 0); + + out_unlock: mutex_unlock(&ftrace_lock); return ret; } +EXPORT_SYMBOL_GPL(register_ftrace_function); /** * unregister_ftrace_function - unregister a function for profiling. @@ -3169,25 +3820,27 @@ int unregister_ftrace_function(struct ftrace_ops *ops) mutex_lock(&ftrace_lock); ret = __unregister_ftrace_function(ops); - ftrace_shutdown(0); + if (!ret) + ftrace_shutdown(ops, 0); mutex_unlock(&ftrace_lock); return ret; } +EXPORT_SYMBOL_GPL(unregister_ftrace_function); int ftrace_enable_sysctl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret; - - if (unlikely(ftrace_disabled)) - return -ENODEV; + int ret = -ENODEV; mutex_lock(&ftrace_lock); - ret = proc_dointvec(table, write, buffer, lenp, ppos); + if (unlikely(ftrace_disabled)) + goto out; + + ret = proc_dointvec(table, write, buffer, lenp, ppos); if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) goto out; @@ -3199,11 +3852,11 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, ftrace_startup_sysctl(); /* we are starting ftrace again */ - if (ftrace_list != &ftrace_list_end) { - if (ftrace_list->next == &ftrace_list_end) - ftrace_trace_function = ftrace_list->func; + if (ftrace_ops_list != &ftrace_list_end) { + if (ftrace_ops_list->next == &ftrace_list_end) + ftrace_trace_function = ftrace_ops_list->func; else - ftrace_trace_function = ftrace_list_func; + ftrace_trace_function = ftrace_ops_list_func; } } else { @@ -3392,7 +4045,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc, ftrace_graph_return = retfunc; ftrace_graph_entry = entryfunc; - ftrace_startup(FTRACE_START_FUNC_RET); + ftrace_startup(&global_ops, FTRACE_START_FUNC_RET); out: mutex_unlock(&ftrace_lock); @@ -3409,7 +4062,7 @@ void unregister_ftrace_graph(void) ftrace_graph_active--; ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; ftrace_graph_entry = ftrace_graph_entry_stub; - ftrace_shutdown(FTRACE_STOP_FUNC_RET); + ftrace_shutdown(&global_ops, FTRACE_STOP_FUNC_RET); unregister_pm_notifier(&ftrace_suspend_notifier); unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d38c16a06a6f..ee9c921d7f21 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1110,6 +1110,7 @@ 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) | @@ -2013,9 +2014,10 @@ enum print_line_t print_trace_line(struct trace_iterator *iter) { enum print_line_t ret; - if (iter->lost_events) - trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", - iter->cpu, iter->lost_events); + if (iter->lost_events && + !trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", + iter->cpu, iter->lost_events)) + return TRACE_TYPE_PARTIAL_LINE; if (iter->trace && iter->trace->print_line) { ret = iter->trace->print_line(iter); @@ -3229,6 +3231,14 @@ waitagain: if (iter->seq.len >= cnt) break; + + /* + * Setting the full flag means we reached the trace_seq buffer + * size and we should leave by partial output condition above. + * One of the trace_seq_* functions is not used properly. + */ + WARN_ONCE(iter->seq.full, "full flag set for trace type %d", + iter->ent->type); } trace_access_unlock(iter->cpu_file); trace_event_read_unlock(); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 5e9dfc6286dd..6b69c4bd306f 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -419,6 +419,8 @@ extern void trace_find_cmdline(int pid, char comm[]); extern unsigned long ftrace_update_tot_cnt; #define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func extern int DYN_FTRACE_TEST_NAME(void); +#define DYN_FTRACE_TEST_NAME2 trace_selftest_dynamic_test_func2 +extern int DYN_FTRACE_TEST_NAME2(void); #endif extern int ring_buffer_expanded; diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index e88f74fe1d4c..2fe110341359 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -116,6 +116,7 @@ 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 16aee4d44e8f..8d0e1cc4e974 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -149,11 +149,13 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip) static struct ftrace_ops trace_ops __read_mostly = { .func = function_trace_call, + .flags = FTRACE_OPS_FL_GLOBAL, }; static struct ftrace_ops trace_stack_ops __read_mostly = { .func = function_stack_trace_call, + .flags = FTRACE_OPS_FL_GLOBAL, }; /* Our two options */ diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index a4969b47afc1..c77424be284d 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -153,6 +153,7 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip) static struct ftrace_ops trace_ops __read_mostly = { .func = irqsoff_tracer_call, + .flags = FTRACE_OPS_FL_GLOBAL, }; #endif /* CONFIG_FUNCTION_TRACER */ diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 35d55a386145..f925c45f0afa 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -53,7 +53,6 @@ const char *reserved_field_names[] = { "common_preempt_count", "common_pid", "common_tgid", - "common_lock_depth", FIELD_STRING_IP, FIELD_STRING_RETIP, FIELD_STRING_FUNC, diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 456be9063c2d..cf535ccedc86 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -830,6 +830,9 @@ EXPORT_SYMBOL_GPL(unregister_ftrace_event); enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags, struct trace_event *event) { + if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type)) + return TRACE_TYPE_PARTIAL_LINE; + return TRACE_TYPE_HANDLED; } diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index 2547d8813cf0..dff763b7baf1 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -32,7 +32,7 @@ static DEFINE_MUTEX(btrace_mutex); struct trace_bprintk_fmt { struct list_head list; - char fmt[0]; + const char *fmt; }; static inline struct trace_bprintk_fmt *lookup_format(const char *fmt) @@ -49,6 +49,7 @@ static void hold_module_trace_bprintk_format(const char **start, const char **end) { const char **iter; + char *fmt; mutex_lock(&btrace_mutex); for (iter = start; iter < end; iter++) { @@ -58,14 +59,18 @@ void hold_module_trace_bprintk_format(const char **start, const char **end) continue; } - tb_fmt = kmalloc(offsetof(struct trace_bprintk_fmt, fmt) - + strlen(*iter) + 1, GFP_KERNEL); - if (tb_fmt) { + tb_fmt = kmalloc(sizeof(*tb_fmt), GFP_KERNEL); + if (tb_fmt) + fmt = kmalloc(strlen(*iter) + 1, GFP_KERNEL); + if (tb_fmt && fmt) { list_add_tail(&tb_fmt->list, &trace_bprintk_fmt_list); - strcpy(tb_fmt->fmt, *iter); + strcpy(fmt, *iter); + tb_fmt->fmt = fmt; *iter = tb_fmt->fmt; - } else + } else { + kfree(tb_fmt); *iter = NULL; + } } mutex_unlock(&btrace_mutex); } @@ -84,6 +89,76 @@ static int module_trace_bprintk_format_notify(struct notifier_block *self, return 0; } +/* + * The debugfs/tracing/printk_formats file maps the addresses with + * the ASCII formats that are used in the bprintk events in the + * buffer. For userspace tools to be able to decode the events from + * the buffer, they need to be able to map the address with the format. + * + * The addresses of the bprintk formats are in their own section + * __trace_printk_fmt. But for modules we copy them into a link list. + * The code to print the formats and their addresses passes around the + * address of the fmt string. If the fmt address passed into the seq + * functions is within the kernel core __trace_printk_fmt section, then + * it simply uses the next pointer in the list. + * + * When the fmt pointer is outside the kernel core __trace_printk_fmt + * section, then we need to read the link list pointers. The trick is + * we pass the address of the string to the seq function just like + * we do for the kernel core formats. To get back the structure that + * holds the format, we simply use containerof() and then go to the + * next format in the list. + */ +static const char ** +find_next_mod_format(int start_index, void *v, const char **fmt, loff_t *pos) +{ + struct trace_bprintk_fmt *mod_fmt; + + if (list_empty(&trace_bprintk_fmt_list)) + return NULL; + + /* + * v will point to the address of the fmt record from t_next + * v will be NULL from t_start. + * If this is the first pointer or called from start + * then we need to walk the list. + */ + if (!v || start_index == *pos) { + struct trace_bprintk_fmt *p; + + /* search the module list */ + list_for_each_entry(p, &trace_bprintk_fmt_list, list) { + if (start_index == *pos) + return &p->fmt; + start_index++; + } + /* pos > index */ + return NULL; + } + + /* + * v points to the address of the fmt field in the mod list + * structure that holds the module print format. + */ + mod_fmt = container_of(v, typeof(*mod_fmt), fmt); + if (mod_fmt->list.next == &trace_bprintk_fmt_list) + return NULL; + + mod_fmt = container_of(mod_fmt->list.next, typeof(*mod_fmt), list); + + return &mod_fmt->fmt; +} + +static void format_mod_start(void) +{ + mutex_lock(&btrace_mutex); +} + +static void format_mod_stop(void) +{ + mutex_unlock(&btrace_mutex); +} + #else /* !CONFIG_MODULES */ __init static int module_trace_bprintk_format_notify(struct notifier_block *self, @@ -91,6 +166,13 @@ module_trace_bprintk_format_notify(struct notifier_block *self, { return 0; } +static inline const char ** +find_next_mod_format(int start_index, void *v, const char **fmt, loff_t *pos) +{ + return NULL; +} +static inline void format_mod_start(void) { } +static inline void format_mod_stop(void) { } #endif /* CONFIG_MODULES */ @@ -153,20 +235,33 @@ int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap) } EXPORT_SYMBOL_GPL(__ftrace_vprintk); +static const char **find_next(void *v, loff_t *pos) +{ + const char **fmt = v; + int start_index; + + if (!fmt) + fmt = __start___trace_bprintk_fmt + *pos; + + start_index = __stop___trace_bprintk_fmt - __start___trace_bprintk_fmt; + + if (*pos < start_index) + return fmt; + + return find_next_mod_format(start_index, v, fmt, pos); +} + static void * t_start(struct seq_file *m, loff_t *pos) { - const char **fmt = __start___trace_bprintk_fmt + *pos; - - if ((unsigned long)fmt >= (unsigned long)__stop___trace_bprintk_fmt) - return NULL; - return fmt; + format_mod_start(); + return find_next(NULL, pos); } static void *t_next(struct seq_file *m, void * v, loff_t *pos) { (*pos)++; - return t_start(m, pos); + return find_next(v, pos); } static int t_show(struct seq_file *m, void *v) @@ -205,6 +300,7 @@ static int t_show(struct seq_file *m, void *v) static void t_stop(struct seq_file *m, void *p) { + format_mod_stop(); } static const struct seq_operations show_format_seq_ops = { diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 7319559ed59f..f029dd4fd2ca 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -129,6 +129,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip) static struct ftrace_ops trace_ops __read_mostly = { .func = wakeup_tracer_call, + .flags = FTRACE_OPS_FL_GLOBAL, }; #endif /* CONFIG_FUNCTION_TRACER */ diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 659732eba07c..288541f977fb 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -101,6 +101,206 @@ static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret) #ifdef CONFIG_DYNAMIC_FTRACE +static int trace_selftest_test_probe1_cnt; +static void trace_selftest_test_probe1_func(unsigned long ip, + unsigned long pip) +{ + trace_selftest_test_probe1_cnt++; +} + +static int trace_selftest_test_probe2_cnt; +static void trace_selftest_test_probe2_func(unsigned long ip, + unsigned long pip) +{ + trace_selftest_test_probe2_cnt++; +} + +static int trace_selftest_test_probe3_cnt; +static void trace_selftest_test_probe3_func(unsigned long ip, + unsigned long pip) +{ + trace_selftest_test_probe3_cnt++; +} + +static int trace_selftest_test_global_cnt; +static void trace_selftest_test_global_func(unsigned long ip, + unsigned long pip) +{ + trace_selftest_test_global_cnt++; +} + +static int trace_selftest_test_dyn_cnt; +static void trace_selftest_test_dyn_func(unsigned long ip, + unsigned long pip) +{ + trace_selftest_test_dyn_cnt++; +} + +static struct ftrace_ops test_probe1 = { + .func = trace_selftest_test_probe1_func, +}; + +static struct ftrace_ops test_probe2 = { + .func = trace_selftest_test_probe2_func, +}; + +static struct ftrace_ops test_probe3 = { + .func = trace_selftest_test_probe3_func, +}; + +static struct ftrace_ops test_global = { + .func = trace_selftest_test_global_func, + .flags = FTRACE_OPS_FL_GLOBAL, +}; + +static void print_counts(void) +{ + printk("(%d %d %d %d %d) ", + trace_selftest_test_probe1_cnt, + trace_selftest_test_probe2_cnt, + trace_selftest_test_probe3_cnt, + trace_selftest_test_global_cnt, + trace_selftest_test_dyn_cnt); +} + +static void reset_counts(void) +{ + trace_selftest_test_probe1_cnt = 0; + trace_selftest_test_probe2_cnt = 0; + trace_selftest_test_probe3_cnt = 0; + trace_selftest_test_global_cnt = 0; + trace_selftest_test_dyn_cnt = 0; +} + +static int trace_selftest_ops(int cnt) +{ + int save_ftrace_enabled = ftrace_enabled; + struct ftrace_ops *dyn_ops; + char *func1_name; + char *func2_name; + int len1; + int len2; + int ret = -1; + + printk(KERN_CONT "PASSED\n"); + pr_info("Testing dynamic ftrace ops #%d: ", cnt); + + ftrace_enabled = 1; + reset_counts(); + + /* Handle PPC64 '.' name */ + func1_name = "*" __stringify(DYN_FTRACE_TEST_NAME); + func2_name = "*" __stringify(DYN_FTRACE_TEST_NAME2); + len1 = strlen(func1_name); + len2 = strlen(func2_name); + + /* + * Probe 1 will trace function 1. + * Probe 2 will trace function 2. + * Probe 3 will trace functions 1 and 2. + */ + ftrace_set_filter(&test_probe1, func1_name, len1, 1); + ftrace_set_filter(&test_probe2, func2_name, len2, 1); + ftrace_set_filter(&test_probe3, func1_name, len1, 1); + ftrace_set_filter(&test_probe3, func2_name, len2, 0); + + register_ftrace_function(&test_probe1); + register_ftrace_function(&test_probe2); + register_ftrace_function(&test_probe3); + register_ftrace_function(&test_global); + + DYN_FTRACE_TEST_NAME(); + + print_counts(); + + if (trace_selftest_test_probe1_cnt != 1) + goto out; + if (trace_selftest_test_probe2_cnt != 0) + goto out; + if (trace_selftest_test_probe3_cnt != 1) + goto out; + if (trace_selftest_test_global_cnt == 0) + goto out; + + DYN_FTRACE_TEST_NAME2(); + + print_counts(); + + if (trace_selftest_test_probe1_cnt != 1) + goto out; + if (trace_selftest_test_probe2_cnt != 1) + goto out; + if (trace_selftest_test_probe3_cnt != 2) + goto out; + + /* Add a dynamic probe */ + dyn_ops = kzalloc(sizeof(*dyn_ops), GFP_KERNEL); + if (!dyn_ops) { + printk("MEMORY ERROR "); + goto out; + } + + dyn_ops->func = trace_selftest_test_dyn_func; + + register_ftrace_function(dyn_ops); + + trace_selftest_test_global_cnt = 0; + + DYN_FTRACE_TEST_NAME(); + + print_counts(); + + if (trace_selftest_test_probe1_cnt != 2) + goto out_free; + if (trace_selftest_test_probe2_cnt != 1) + goto out_free; + if (trace_selftest_test_probe3_cnt != 3) + goto out_free; + if (trace_selftest_test_global_cnt == 0) + goto out; + if (trace_selftest_test_dyn_cnt == 0) + goto out_free; + + DYN_FTRACE_TEST_NAME2(); + + print_counts(); + + if (trace_selftest_test_probe1_cnt != 2) + goto out_free; + if (trace_selftest_test_probe2_cnt != 2) + goto out_free; + if (trace_selftest_test_probe3_cnt != 4) + goto out_free; + + ret = 0; + out_free: + unregister_ftrace_function(dyn_ops); + kfree(dyn_ops); + + out: + /* Purposely unregister in the same order */ + unregister_ftrace_function(&test_probe1); + unregister_ftrace_function(&test_probe2); + unregister_ftrace_function(&test_probe3); + unregister_ftrace_function(&test_global); + + /* Make sure everything is off */ + reset_counts(); + DYN_FTRACE_TEST_NAME(); + DYN_FTRACE_TEST_NAME(); + + if (trace_selftest_test_probe1_cnt || + trace_selftest_test_probe2_cnt || + trace_selftest_test_probe3_cnt || + trace_selftest_test_global_cnt || + trace_selftest_test_dyn_cnt) + ret = -1; + + ftrace_enabled = save_ftrace_enabled; + + return ret; +} + /* Test dynamic code modification and ftrace filters */ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, struct trace_array *tr, @@ -131,7 +331,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, func_name = "*" __stringify(DYN_FTRACE_TEST_NAME); /* filter only on our function */ - ftrace_set_filter(func_name, strlen(func_name), 1); + ftrace_set_global_filter(func_name, strlen(func_name), 1); /* enable tracing */ ret = tracer_init(trace, tr); @@ -166,22 +366,30 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, /* check the trace buffer */ ret = trace_test_buffer(tr, &count); - trace->reset(tr); tracing_start(); /* we should only have one item */ if (!ret && count != 1) { + trace->reset(tr); printk(KERN_CONT ".. filter failed count=%ld ..", count); ret = -1; goto out; } + /* Test the ops with global tracing running */ + ret = trace_selftest_ops(1); + trace->reset(tr); + out: ftrace_enabled = save_ftrace_enabled; tracer_enabled = save_tracer_enabled; /* Enable tracing on all functions again */ - ftrace_set_filter(NULL, 0, 1); + ftrace_set_global_filter(NULL, 0, 1); + + /* Test the ops with global tracing off */ + if (!ret) + ret = trace_selftest_ops(2); return ret; } diff --git a/kernel/trace/trace_selftest_dynamic.c b/kernel/trace/trace_selftest_dynamic.c index 54dd77cce5bf..b4c475a0a48b 100644 --- a/kernel/trace/trace_selftest_dynamic.c +++ b/kernel/trace/trace_selftest_dynamic.c @@ -5,3 +5,9 @@ int DYN_FTRACE_TEST_NAME(void) /* used to call mcount */ return 0; } + +int DYN_FTRACE_TEST_NAME2(void) +{ + /* used to call mcount */ + return 0; +} diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 4c5dead0c239..b0b53b8e4c25 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -133,6 +133,7 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip) static struct ftrace_ops trace_ops __read_mostly = { .func = stack_trace_call, + .flags = FTRACE_OPS_FL_GLOBAL, }; static ssize_t diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 68187af4889e..b219f1449c54 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -251,9 +251,9 @@ static void set_tracepoint(struct tracepoint_entry **entry, { WARN_ON(strcmp((*entry)->name, elem->name) != 0); - if (elem->regfunc && !elem->state && active) + if (elem->regfunc && !jump_label_enabled(&elem->key) && active) elem->regfunc(); - else if (elem->unregfunc && elem->state && !active) + else if (elem->unregfunc && jump_label_enabled(&elem->key) && !active) elem->unregfunc(); /* @@ -264,13 +264,10 @@ static void set_tracepoint(struct tracepoint_entry **entry, * is used. */ rcu_assign_pointer(elem->funcs, (*entry)->funcs); - if (!elem->state && active) { - jump_label_enable(&elem->state); - elem->state = active; - } else if (elem->state && !active) { - jump_label_disable(&elem->state); - elem->state = active; - } + if (active && !jump_label_enabled(&elem->key)) + jump_label_inc(&elem->key); + else if (!active && jump_label_enabled(&elem->key)) + jump_label_dec(&elem->key); } /* @@ -281,13 +278,11 @@ static void set_tracepoint(struct tracepoint_entry **entry, */ static void disable_tracepoint(struct tracepoint *elem) { - if (elem->unregfunc && elem->state) + if (elem->unregfunc && jump_label_enabled(&elem->key)) elem->unregfunc(); - if (elem->state) { - jump_label_disable(&elem->state); - elem->state = 0; - } + if (jump_label_enabled(&elem->key)) + jump_label_dec(&elem->key); rcu_assign_pointer(elem->funcs, NULL); } |