2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/file.h>
17 #include <linux/poll.h>
18 #include <linux/slab.h>
19 #include <linux/sysfs.h>
20 #include <linux/dcache.h>
21 #include <linux/percpu.h>
22 #include <linux/ptrace.h>
23 #include <linux/vmstat.h>
24 #include <linux/vmalloc.h>
25 #include <linux/hardirq.h>
26 #include <linux/rculist.h>
27 #include <linux/uaccess.h>
28 #include <linux/syscalls.h>
29 #include <linux/anon_inodes.h>
30 #include <linux/kernel_stat.h>
31 #include <linux/perf_event.h>
32 #include <linux/ftrace_event.h>
33 #include <linux/hw_breakpoint.h>
35 #include <asm/irq_regs.h>
38 * Each CPU has a list of per CPU events:
40 static DEFINE_PER_CPU(struct perf_cpu_context
, perf_cpu_context
);
42 int perf_max_events __read_mostly
= 1;
43 static int perf_reserved_percpu __read_mostly
;
44 static int perf_overcommit __read_mostly
= 1;
46 static atomic_t nr_events __read_mostly
;
47 static atomic_t nr_mmap_events __read_mostly
;
48 static atomic_t nr_comm_events __read_mostly
;
49 static atomic_t nr_task_events __read_mostly
;
52 * perf event paranoia level:
53 * -1 - not paranoid at all
54 * 0 - disallow raw tracepoint access for unpriv
55 * 1 - disallow cpu events for unpriv
56 * 2 - disallow kernel profiling for unpriv
58 int sysctl_perf_event_paranoid __read_mostly
= 1;
60 int sysctl_perf_event_mlock __read_mostly
= 512; /* 'free' kb per user */
63 * max perf event sample rate
65 int sysctl_perf_event_sample_rate __read_mostly
= 100000;
67 static atomic64_t perf_event_id
;
70 * Lock for (sysadmin-configurable) event reservations:
72 static DEFINE_SPINLOCK(perf_resource_lock
);
75 * Architecture provided APIs - weak aliases:
77 extern __weak
const struct pmu
*hw_perf_event_init(struct perf_event
*event
)
82 void __weak
hw_perf_disable(void) { barrier(); }
83 void __weak
hw_perf_enable(void) { barrier(); }
86 hw_perf_group_sched_in(struct perf_event
*group_leader
,
87 struct perf_cpu_context
*cpuctx
,
88 struct perf_event_context
*ctx
)
93 void __weak
perf_event_print_debug(void) { }
95 static DEFINE_PER_CPU(int, perf_disable_count
);
97 void perf_disable(void)
99 if (!__get_cpu_var(perf_disable_count
)++)
103 void perf_enable(void)
105 if (!--__get_cpu_var(perf_disable_count
))
109 static void get_ctx(struct perf_event_context
*ctx
)
111 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
114 static void free_ctx(struct rcu_head
*head
)
116 struct perf_event_context
*ctx
;
118 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
122 static void put_ctx(struct perf_event_context
*ctx
)
124 if (atomic_dec_and_test(&ctx
->refcount
)) {
126 put_ctx(ctx
->parent_ctx
);
128 put_task_struct(ctx
->task
);
129 call_rcu(&ctx
->rcu_head
, free_ctx
);
133 static void unclone_ctx(struct perf_event_context
*ctx
)
135 if (ctx
->parent_ctx
) {
136 put_ctx(ctx
->parent_ctx
);
137 ctx
->parent_ctx
= NULL
;
142 * If we inherit events we want to return the parent event id
145 static u64
primary_event_id(struct perf_event
*event
)
150 id
= event
->parent
->id
;
156 * Get the perf_event_context for a task and lock it.
157 * This has to cope with with the fact that until it is locked,
158 * the context could get moved to another task.
160 static struct perf_event_context
*
161 perf_lock_task_context(struct task_struct
*task
, unsigned long *flags
)
163 struct perf_event_context
*ctx
;
167 ctx
= rcu_dereference(task
->perf_event_ctxp
);
170 * If this context is a clone of another, it might
171 * get swapped for another underneath us by
172 * perf_event_task_sched_out, though the
173 * rcu_read_lock() protects us from any context
174 * getting freed. Lock the context and check if it
175 * got swapped before we could get the lock, and retry
176 * if so. If we locked the right context, then it
177 * can't get swapped on us any more.
179 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
180 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
)) {
181 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
185 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
186 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
195 * Get the context for a task and increment its pin_count so it
196 * can't get swapped to another task. This also increments its
197 * reference count so that the context can't get freed.
199 static struct perf_event_context
*perf_pin_task_context(struct task_struct
*task
)
201 struct perf_event_context
*ctx
;
204 ctx
= perf_lock_task_context(task
, &flags
);
207 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
212 static void perf_unpin_context(struct perf_event_context
*ctx
)
216 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
218 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
222 static inline u64
perf_clock(void)
224 return cpu_clock(raw_smp_processor_id());
228 * Update the record of the current time in a context.
230 static void update_context_time(struct perf_event_context
*ctx
)
232 u64 now
= perf_clock();
234 ctx
->time
+= now
- ctx
->timestamp
;
235 ctx
->timestamp
= now
;
239 * Update the total_time_enabled and total_time_running fields for a event.
241 static void update_event_times(struct perf_event
*event
)
243 struct perf_event_context
*ctx
= event
->ctx
;
246 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
247 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
253 run_end
= event
->tstamp_stopped
;
255 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
257 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
258 run_end
= event
->tstamp_stopped
;
262 event
->total_time_running
= run_end
- event
->tstamp_running
;
265 static struct list_head
*
266 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
268 if (event
->attr
.pinned
)
269 return &ctx
->pinned_groups
;
271 return &ctx
->flexible_groups
;
275 * Add a event from the lists for its context.
276 * Must be called with ctx->mutex and ctx->lock held.
279 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
281 struct perf_event
*group_leader
= event
->group_leader
;
284 * Depending on whether it is a standalone or sibling event,
285 * add it straight to the context's event list, or to the group
286 * leader's sibling list:
288 if (group_leader
== event
) {
289 struct list_head
*list
;
291 if (is_software_event(event
))
292 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
294 list
= ctx_group_list(event
, ctx
);
295 list_add_tail(&event
->group_entry
, list
);
297 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
298 !is_software_event(event
))
299 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
301 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
302 group_leader
->nr_siblings
++;
305 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
307 if (event
->attr
.inherit_stat
)
312 * Remove a event from the lists for its context.
313 * Must be called with ctx->mutex and ctx->lock held.
316 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
318 struct perf_event
*sibling
, *tmp
;
320 if (list_empty(&event
->group_entry
))
323 if (event
->attr
.inherit_stat
)
326 list_del_init(&event
->group_entry
);
327 list_del_rcu(&event
->event_entry
);
329 if (event
->group_leader
!= event
)
330 event
->group_leader
->nr_siblings
--;
332 update_event_times(event
);
335 * If event was in error state, then keep it
336 * that way, otherwise bogus counts will be
337 * returned on read(). The only way to get out
338 * of error state is by explicit re-enabling
341 if (event
->state
> PERF_EVENT_STATE_OFF
)
342 event
->state
= PERF_EVENT_STATE_OFF
;
345 * If this was a group event with sibling events then
346 * upgrade the siblings to singleton events by adding them
347 * to the context list directly:
349 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
350 struct list_head
*list
;
352 list
= ctx_group_list(event
, ctx
);
353 list_move_tail(&sibling
->group_entry
, list
);
354 sibling
->group_leader
= sibling
;
356 /* Inherit group flags from the previous leader */
357 sibling
->group_flags
= event
->group_flags
;
362 event_sched_out(struct perf_event
*event
,
363 struct perf_cpu_context
*cpuctx
,
364 struct perf_event_context
*ctx
)
366 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
369 event
->state
= PERF_EVENT_STATE_INACTIVE
;
370 if (event
->pending_disable
) {
371 event
->pending_disable
= 0;
372 event
->state
= PERF_EVENT_STATE_OFF
;
374 event
->tstamp_stopped
= ctx
->time
;
375 event
->pmu
->disable(event
);
378 if (!is_software_event(event
))
379 cpuctx
->active_oncpu
--;
381 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
382 cpuctx
->exclusive
= 0;
386 group_sched_out(struct perf_event
*group_event
,
387 struct perf_cpu_context
*cpuctx
,
388 struct perf_event_context
*ctx
)
390 struct perf_event
*event
;
392 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
395 event_sched_out(group_event
, cpuctx
, ctx
);
398 * Schedule out siblings (if any):
400 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
401 event_sched_out(event
, cpuctx
, ctx
);
403 if (group_event
->attr
.exclusive
)
404 cpuctx
->exclusive
= 0;
408 * Cross CPU call to remove a performance event
410 * We disable the event on the hardware level first. After that we
411 * remove it from the context list.
413 static void __perf_event_remove_from_context(void *info
)
415 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
416 struct perf_event
*event
= info
;
417 struct perf_event_context
*ctx
= event
->ctx
;
420 * If this is a task context, we need to check whether it is
421 * the current task context of this cpu. If not it has been
422 * scheduled out before the smp call arrived.
424 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
427 raw_spin_lock(&ctx
->lock
);
429 * Protect the list operation against NMI by disabling the
430 * events on a global level.
434 event_sched_out(event
, cpuctx
, ctx
);
436 list_del_event(event
, ctx
);
440 * Allow more per task events with respect to the
443 cpuctx
->max_pertask
=
444 min(perf_max_events
- ctx
->nr_events
,
445 perf_max_events
- perf_reserved_percpu
);
449 raw_spin_unlock(&ctx
->lock
);
454 * Remove the event from a task's (or a CPU's) list of events.
456 * Must be called with ctx->mutex held.
458 * CPU events are removed with a smp call. For task events we only
459 * call when the task is on a CPU.
461 * If event->ctx is a cloned context, callers must make sure that
462 * every task struct that event->ctx->task could possibly point to
463 * remains valid. This is OK when called from perf_release since
464 * that only calls us on the top-level context, which can't be a clone.
465 * When called from perf_event_exit_task, it's OK because the
466 * context has been detached from its task.
468 static void perf_event_remove_from_context(struct perf_event
*event
)
470 struct perf_event_context
*ctx
= event
->ctx
;
471 struct task_struct
*task
= ctx
->task
;
475 * Per cpu events are removed via an smp call and
476 * the removal is always successful.
478 smp_call_function_single(event
->cpu
,
479 __perf_event_remove_from_context
,
485 task_oncpu_function_call(task
, __perf_event_remove_from_context
,
488 raw_spin_lock_irq(&ctx
->lock
);
490 * If the context is active we need to retry the smp call.
492 if (ctx
->nr_active
&& !list_empty(&event
->group_entry
)) {
493 raw_spin_unlock_irq(&ctx
->lock
);
498 * The lock prevents that this context is scheduled in so we
499 * can remove the event safely, if the call above did not
502 if (!list_empty(&event
->group_entry
))
503 list_del_event(event
, ctx
);
504 raw_spin_unlock_irq(&ctx
->lock
);
508 * Update total_time_enabled and total_time_running for all events in a group.
510 static void update_group_times(struct perf_event
*leader
)
512 struct perf_event
*event
;
514 update_event_times(leader
);
515 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
516 update_event_times(event
);
520 * Cross CPU call to disable a performance event
522 static void __perf_event_disable(void *info
)
524 struct perf_event
*event
= info
;
525 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
526 struct perf_event_context
*ctx
= event
->ctx
;
529 * If this is a per-task event, need to check whether this
530 * event's task is the current task on this cpu.
532 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
535 raw_spin_lock(&ctx
->lock
);
538 * If the event is on, turn it off.
539 * If it is in error state, leave it in error state.
541 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
542 update_context_time(ctx
);
543 update_group_times(event
);
544 if (event
== event
->group_leader
)
545 group_sched_out(event
, cpuctx
, ctx
);
547 event_sched_out(event
, cpuctx
, ctx
);
548 event
->state
= PERF_EVENT_STATE_OFF
;
551 raw_spin_unlock(&ctx
->lock
);
557 * If event->ctx is a cloned context, callers must make sure that
558 * every task struct that event->ctx->task could possibly point to
559 * remains valid. This condition is satisifed when called through
560 * perf_event_for_each_child or perf_event_for_each because they
561 * hold the top-level event's child_mutex, so any descendant that
562 * goes to exit will block in sync_child_event.
563 * When called from perf_pending_event it's OK because event->ctx
564 * is the current context on this CPU and preemption is disabled,
565 * hence we can't get into perf_event_task_sched_out for this context.
567 void perf_event_disable(struct perf_event
*event
)
569 struct perf_event_context
*ctx
= event
->ctx
;
570 struct task_struct
*task
= ctx
->task
;
574 * Disable the event on the cpu that it's on
576 smp_call_function_single(event
->cpu
, __perf_event_disable
,
582 task_oncpu_function_call(task
, __perf_event_disable
, event
);
584 raw_spin_lock_irq(&ctx
->lock
);
586 * If the event is still active, we need to retry the cross-call.
588 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
589 raw_spin_unlock_irq(&ctx
->lock
);
594 * Since we have the lock this context can't be scheduled
595 * in, so we can change the state safely.
597 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
598 update_group_times(event
);
599 event
->state
= PERF_EVENT_STATE_OFF
;
602 raw_spin_unlock_irq(&ctx
->lock
);
606 event_sched_in(struct perf_event
*event
,
607 struct perf_cpu_context
*cpuctx
,
608 struct perf_event_context
*ctx
)
610 if (event
->state
<= PERF_EVENT_STATE_OFF
)
613 event
->state
= PERF_EVENT_STATE_ACTIVE
;
614 event
->oncpu
= smp_processor_id();
616 * The new state must be visible before we turn it on in the hardware:
620 if (event
->pmu
->enable(event
)) {
621 event
->state
= PERF_EVENT_STATE_INACTIVE
;
626 event
->tstamp_running
+= ctx
->time
- event
->tstamp_stopped
;
628 if (!is_software_event(event
))
629 cpuctx
->active_oncpu
++;
632 if (event
->attr
.exclusive
)
633 cpuctx
->exclusive
= 1;
639 group_sched_in(struct perf_event
*group_event
,
640 struct perf_cpu_context
*cpuctx
,
641 struct perf_event_context
*ctx
)
643 struct perf_event
*event
, *partial_group
;
646 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
649 ret
= hw_perf_group_sched_in(group_event
, cpuctx
, ctx
);
651 return ret
< 0 ? ret
: 0;
653 if (event_sched_in(group_event
, cpuctx
, ctx
))
657 * Schedule in siblings as one group (if any):
659 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
660 if (event_sched_in(event
, cpuctx
, ctx
)) {
661 partial_group
= event
;
670 * Groups can be scheduled in as one unit only, so undo any
671 * partial group before returning:
673 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
674 if (event
== partial_group
)
676 event_sched_out(event
, cpuctx
, ctx
);
678 event_sched_out(group_event
, cpuctx
, ctx
);
684 * Work out whether we can put this event group on the CPU now.
686 static int group_can_go_on(struct perf_event
*event
,
687 struct perf_cpu_context
*cpuctx
,
691 * Groups consisting entirely of software events can always go on.
693 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
696 * If an exclusive group is already on, no other hardware
699 if (cpuctx
->exclusive
)
702 * If this group is exclusive and there are already
703 * events on the CPU, it can't go on.
705 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
708 * Otherwise, try to add it if all previous groups were able
714 static void add_event_to_ctx(struct perf_event
*event
,
715 struct perf_event_context
*ctx
)
717 list_add_event(event
, ctx
);
718 event
->tstamp_enabled
= ctx
->time
;
719 event
->tstamp_running
= ctx
->time
;
720 event
->tstamp_stopped
= ctx
->time
;
724 * Cross CPU call to install and enable a performance event
726 * Must be called with ctx->mutex held
728 static void __perf_install_in_context(void *info
)
730 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
731 struct perf_event
*event
= info
;
732 struct perf_event_context
*ctx
= event
->ctx
;
733 struct perf_event
*leader
= event
->group_leader
;
737 * If this is a task context, we need to check whether it is
738 * the current task context of this cpu. If not it has been
739 * scheduled out before the smp call arrived.
740 * Or possibly this is the right context but it isn't
741 * on this cpu because it had no events.
743 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
744 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
746 cpuctx
->task_ctx
= ctx
;
749 raw_spin_lock(&ctx
->lock
);
751 update_context_time(ctx
);
754 * Protect the list operation against NMI by disabling the
755 * events on a global level. NOP for non NMI based events.
759 add_event_to_ctx(event
, ctx
);
761 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
765 * Don't put the event on if it is disabled or if
766 * it is in a group and the group isn't on.
768 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
769 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
773 * An exclusive event can't go on if there are already active
774 * hardware events, and no hardware event can go on if there
775 * is already an exclusive event on.
777 if (!group_can_go_on(event
, cpuctx
, 1))
780 err
= event_sched_in(event
, cpuctx
, ctx
);
784 * This event couldn't go on. If it is in a group
785 * then we have to pull the whole group off.
786 * If the event group is pinned then put it in error state.
789 group_sched_out(leader
, cpuctx
, ctx
);
790 if (leader
->attr
.pinned
) {
791 update_group_times(leader
);
792 leader
->state
= PERF_EVENT_STATE_ERROR
;
796 if (!err
&& !ctx
->task
&& cpuctx
->max_pertask
)
797 cpuctx
->max_pertask
--;
802 raw_spin_unlock(&ctx
->lock
);
806 * Attach a performance event to a context
808 * First we add the event to the list with the hardware enable bit
809 * in event->hw_config cleared.
811 * If the event is attached to a task which is on a CPU we use a smp
812 * call to enable it in the task context. The task might have been
813 * scheduled away, but we check this in the smp call again.
815 * Must be called with ctx->mutex held.
818 perf_install_in_context(struct perf_event_context
*ctx
,
819 struct perf_event
*event
,
822 struct task_struct
*task
= ctx
->task
;
826 * Per cpu events are installed via an smp call and
827 * the install is always successful.
829 smp_call_function_single(cpu
, __perf_install_in_context
,
835 task_oncpu_function_call(task
, __perf_install_in_context
,
838 raw_spin_lock_irq(&ctx
->lock
);
840 * we need to retry the smp call.
842 if (ctx
->is_active
&& list_empty(&event
->group_entry
)) {
843 raw_spin_unlock_irq(&ctx
->lock
);
848 * The lock prevents that this context is scheduled in so we
849 * can add the event safely, if it the call above did not
852 if (list_empty(&event
->group_entry
))
853 add_event_to_ctx(event
, ctx
);
854 raw_spin_unlock_irq(&ctx
->lock
);
858 * Put a event into inactive state and update time fields.
859 * Enabling the leader of a group effectively enables all
860 * the group members that aren't explicitly disabled, so we
861 * have to update their ->tstamp_enabled also.
862 * Note: this works for group members as well as group leaders
863 * since the non-leader members' sibling_lists will be empty.
865 static void __perf_event_mark_enabled(struct perf_event
*event
,
866 struct perf_event_context
*ctx
)
868 struct perf_event
*sub
;
870 event
->state
= PERF_EVENT_STATE_INACTIVE
;
871 event
->tstamp_enabled
= ctx
->time
- event
->total_time_enabled
;
872 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
)
873 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
874 sub
->tstamp_enabled
=
875 ctx
->time
- sub
->total_time_enabled
;
879 * Cross CPU call to enable a performance event
881 static void __perf_event_enable(void *info
)
883 struct perf_event
*event
= info
;
884 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
885 struct perf_event_context
*ctx
= event
->ctx
;
886 struct perf_event
*leader
= event
->group_leader
;
890 * If this is a per-task event, need to check whether this
891 * event's task is the current task on this cpu.
893 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
894 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
896 cpuctx
->task_ctx
= ctx
;
899 raw_spin_lock(&ctx
->lock
);
901 update_context_time(ctx
);
903 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
905 __perf_event_mark_enabled(event
, ctx
);
907 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
911 * If the event is in a group and isn't the group leader,
912 * then don't put it on unless the group is on.
914 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
917 if (!group_can_go_on(event
, cpuctx
, 1)) {
922 err
= group_sched_in(event
, cpuctx
, ctx
);
924 err
= event_sched_in(event
, cpuctx
, ctx
);
930 * If this event can't go on and it's part of a
931 * group, then the whole group has to come off.
934 group_sched_out(leader
, cpuctx
, ctx
);
935 if (leader
->attr
.pinned
) {
936 update_group_times(leader
);
937 leader
->state
= PERF_EVENT_STATE_ERROR
;
942 raw_spin_unlock(&ctx
->lock
);
948 * If event->ctx is a cloned context, callers must make sure that
949 * every task struct that event->ctx->task could possibly point to
950 * remains valid. This condition is satisfied when called through
951 * perf_event_for_each_child or perf_event_for_each as described
952 * for perf_event_disable.
954 void perf_event_enable(struct perf_event
*event
)
956 struct perf_event_context
*ctx
= event
->ctx
;
957 struct task_struct
*task
= ctx
->task
;
961 * Enable the event on the cpu that it's on
963 smp_call_function_single(event
->cpu
, __perf_event_enable
,
968 raw_spin_lock_irq(&ctx
->lock
);
969 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
973 * If the event is in error state, clear that first.
974 * That way, if we see the event in error state below, we
975 * know that it has gone back into error state, as distinct
976 * from the task having been scheduled away before the
977 * cross-call arrived.
979 if (event
->state
== PERF_EVENT_STATE_ERROR
)
980 event
->state
= PERF_EVENT_STATE_OFF
;
983 raw_spin_unlock_irq(&ctx
->lock
);
984 task_oncpu_function_call(task
, __perf_event_enable
, event
);
986 raw_spin_lock_irq(&ctx
->lock
);
989 * If the context is active and the event is still off,
990 * we need to retry the cross-call.
992 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
)
996 * Since we have the lock this context can't be scheduled
997 * in, so we can change the state safely.
999 if (event
->state
== PERF_EVENT_STATE_OFF
)
1000 __perf_event_mark_enabled(event
, ctx
);
1003 raw_spin_unlock_irq(&ctx
->lock
);
1006 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1009 * not supported on inherited events
1011 if (event
->attr
.inherit
)
1014 atomic_add(refresh
, &event
->event_limit
);
1015 perf_event_enable(event
);
1021 EVENT_FLEXIBLE
= 0x1,
1023 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
1026 static void ctx_sched_out(struct perf_event_context
*ctx
,
1027 struct perf_cpu_context
*cpuctx
,
1028 enum event_type_t event_type
)
1030 struct perf_event
*event
;
1032 raw_spin_lock(&ctx
->lock
);
1034 if (likely(!ctx
->nr_events
))
1036 update_context_time(ctx
);
1039 if (!ctx
->nr_active
)
1042 if (event_type
& EVENT_PINNED
)
1043 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1044 group_sched_out(event
, cpuctx
, ctx
);
1046 if (event_type
& EVENT_FLEXIBLE
)
1047 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1048 group_sched_out(event
, cpuctx
, ctx
);
1053 raw_spin_unlock(&ctx
->lock
);
1057 * Test whether two contexts are equivalent, i.e. whether they
1058 * have both been cloned from the same version of the same context
1059 * and they both have the same number of enabled events.
1060 * If the number of enabled events is the same, then the set
1061 * of enabled events should be the same, because these are both
1062 * inherited contexts, therefore we can't access individual events
1063 * in them directly with an fd; we can only enable/disable all
1064 * events via prctl, or enable/disable all events in a family
1065 * via ioctl, which will have the same effect on both contexts.
1067 static int context_equiv(struct perf_event_context
*ctx1
,
1068 struct perf_event_context
*ctx2
)
1070 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1071 && ctx1
->parent_gen
== ctx2
->parent_gen
1072 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1075 static void __perf_event_sync_stat(struct perf_event
*event
,
1076 struct perf_event
*next_event
)
1080 if (!event
->attr
.inherit_stat
)
1084 * Update the event value, we cannot use perf_event_read()
1085 * because we're in the middle of a context switch and have IRQs
1086 * disabled, which upsets smp_call_function_single(), however
1087 * we know the event must be on the current CPU, therefore we
1088 * don't need to use it.
1090 switch (event
->state
) {
1091 case PERF_EVENT_STATE_ACTIVE
:
1092 event
->pmu
->read(event
);
1095 case PERF_EVENT_STATE_INACTIVE
:
1096 update_event_times(event
);
1104 * In order to keep per-task stats reliable we need to flip the event
1105 * values when we flip the contexts.
1107 value
= atomic64_read(&next_event
->count
);
1108 value
= atomic64_xchg(&event
->count
, value
);
1109 atomic64_set(&next_event
->count
, value
);
1111 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1112 swap(event
->total_time_running
, next_event
->total_time_running
);
1115 * Since we swizzled the values, update the user visible data too.
1117 perf_event_update_userpage(event
);
1118 perf_event_update_userpage(next_event
);
1121 #define list_next_entry(pos, member) \
1122 list_entry(pos->member.next, typeof(*pos), member)
1124 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1125 struct perf_event_context
*next_ctx
)
1127 struct perf_event
*event
, *next_event
;
1132 update_context_time(ctx
);
1134 event
= list_first_entry(&ctx
->event_list
,
1135 struct perf_event
, event_entry
);
1137 next_event
= list_first_entry(&next_ctx
->event_list
,
1138 struct perf_event
, event_entry
);
1140 while (&event
->event_entry
!= &ctx
->event_list
&&
1141 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1143 __perf_event_sync_stat(event
, next_event
);
1145 event
= list_next_entry(event
, event_entry
);
1146 next_event
= list_next_entry(next_event
, event_entry
);
1151 * Called from scheduler to remove the events of the current task,
1152 * with interrupts disabled.
1154 * We stop each event and update the event value in event->count.
1156 * This does not protect us against NMI, but disable()
1157 * sets the disabled bit in the control field of event _before_
1158 * accessing the event control register. If a NMI hits, then it will
1159 * not restart the event.
1161 void perf_event_task_sched_out(struct task_struct
*task
,
1162 struct task_struct
*next
)
1164 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1165 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1166 struct perf_event_context
*next_ctx
;
1167 struct perf_event_context
*parent
;
1168 struct pt_regs
*regs
;
1171 regs
= task_pt_regs(task
);
1172 perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES
, 1, 1, regs
, 0);
1174 if (likely(!ctx
|| !cpuctx
->task_ctx
))
1178 parent
= rcu_dereference(ctx
->parent_ctx
);
1179 next_ctx
= next
->perf_event_ctxp
;
1180 if (parent
&& next_ctx
&&
1181 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1183 * Looks like the two contexts are clones, so we might be
1184 * able to optimize the context switch. We lock both
1185 * contexts and check that they are clones under the
1186 * lock (including re-checking that neither has been
1187 * uncloned in the meantime). It doesn't matter which
1188 * order we take the locks because no other cpu could
1189 * be trying to lock both of these tasks.
1191 raw_spin_lock(&ctx
->lock
);
1192 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1193 if (context_equiv(ctx
, next_ctx
)) {
1195 * XXX do we need a memory barrier of sorts
1196 * wrt to rcu_dereference() of perf_event_ctxp
1198 task
->perf_event_ctxp
= next_ctx
;
1199 next
->perf_event_ctxp
= ctx
;
1201 next_ctx
->task
= task
;
1204 perf_event_sync_stat(ctx
, next_ctx
);
1206 raw_spin_unlock(&next_ctx
->lock
);
1207 raw_spin_unlock(&ctx
->lock
);
1212 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1213 cpuctx
->task_ctx
= NULL
;
1217 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1218 enum event_type_t event_type
)
1220 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1222 if (!cpuctx
->task_ctx
)
1225 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1228 ctx_sched_out(ctx
, cpuctx
, event_type
);
1229 cpuctx
->task_ctx
= NULL
;
1233 * Called with IRQs disabled
1235 static void __perf_event_task_sched_out(struct perf_event_context
*ctx
)
1237 task_ctx_sched_out(ctx
, EVENT_ALL
);
1241 * Called with IRQs disabled
1243 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1244 enum event_type_t event_type
)
1246 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1250 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1251 struct perf_cpu_context
*cpuctx
)
1253 struct perf_event
*event
;
1255 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1256 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1258 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1261 if (group_can_go_on(event
, cpuctx
, 1))
1262 group_sched_in(event
, cpuctx
, ctx
);
1265 * If this pinned group hasn't been scheduled,
1266 * put it in error state.
1268 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1269 update_group_times(event
);
1270 event
->state
= PERF_EVENT_STATE_ERROR
;
1276 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
1277 struct perf_cpu_context
*cpuctx
)
1279 struct perf_event
*event
;
1282 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1283 /* Ignore events in OFF or ERROR state */
1284 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1287 * Listen to the 'cpu' scheduling filter constraint
1290 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1293 if (group_can_go_on(event
, cpuctx
, can_add_hw
))
1294 if (group_sched_in(event
, cpuctx
, ctx
))
1300 ctx_sched_in(struct perf_event_context
*ctx
,
1301 struct perf_cpu_context
*cpuctx
,
1302 enum event_type_t event_type
)
1304 raw_spin_lock(&ctx
->lock
);
1306 if (likely(!ctx
->nr_events
))
1309 ctx
->timestamp
= perf_clock();
1314 * First go through the list and put on any pinned groups
1315 * in order to give them the best chance of going on.
1317 if (event_type
& EVENT_PINNED
)
1318 ctx_pinned_sched_in(ctx
, cpuctx
);
1320 /* Then walk through the lower prio flexible groups */
1321 if (event_type
& EVENT_FLEXIBLE
)
1322 ctx_flexible_sched_in(ctx
, cpuctx
);
1326 raw_spin_unlock(&ctx
->lock
);
1329 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
1330 enum event_type_t event_type
)
1332 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
1334 ctx_sched_in(ctx
, cpuctx
, event_type
);
1337 static void task_ctx_sched_in(struct task_struct
*task
,
1338 enum event_type_t event_type
)
1340 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1341 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1345 if (cpuctx
->task_ctx
== ctx
)
1347 ctx_sched_in(ctx
, cpuctx
, event_type
);
1348 cpuctx
->task_ctx
= ctx
;
1351 * Called from scheduler to add the events of the current task
1352 * with interrupts disabled.
1354 * We restore the event value and then enable it.
1356 * This does not protect us against NMI, but enable()
1357 * sets the enabled bit in the control field of event _before_
1358 * accessing the event control register. If a NMI hits, then it will
1359 * keep the event running.
1361 void perf_event_task_sched_in(struct task_struct
*task
)
1363 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1364 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1369 if (cpuctx
->task_ctx
== ctx
)
1373 * We want to keep the following priority order:
1374 * cpu pinned (that don't need to move), task pinned,
1375 * cpu flexible, task flexible.
1377 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1379 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
);
1380 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1381 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
);
1383 cpuctx
->task_ctx
= ctx
;
1386 #define MAX_INTERRUPTS (~0ULL)
1388 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1390 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1392 u64 frequency
= event
->attr
.sample_freq
;
1393 u64 sec
= NSEC_PER_SEC
;
1394 u64 divisor
, dividend
;
1396 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
1398 count_fls
= fls64(count
);
1399 nsec_fls
= fls64(nsec
);
1400 frequency_fls
= fls64(frequency
);
1404 * We got @count in @nsec, with a target of sample_freq HZ
1405 * the target period becomes:
1408 * period = -------------------
1409 * @nsec * sample_freq
1414 * Reduce accuracy by one bit such that @a and @b converge
1415 * to a similar magnitude.
1417 #define REDUCE_FLS(a, b) \
1419 if (a##_fls > b##_fls) { \
1429 * Reduce accuracy until either term fits in a u64, then proceed with
1430 * the other, so that finally we can do a u64/u64 division.
1432 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
1433 REDUCE_FLS(nsec
, frequency
);
1434 REDUCE_FLS(sec
, count
);
1437 if (count_fls
+ sec_fls
> 64) {
1438 divisor
= nsec
* frequency
;
1440 while (count_fls
+ sec_fls
> 64) {
1441 REDUCE_FLS(count
, sec
);
1445 dividend
= count
* sec
;
1447 dividend
= count
* sec
;
1449 while (nsec_fls
+ frequency_fls
> 64) {
1450 REDUCE_FLS(nsec
, frequency
);
1454 divisor
= nsec
* frequency
;
1457 return div64_u64(dividend
, divisor
);
1460 static void perf_event_stop(struct perf_event
*event
)
1462 if (!event
->pmu
->stop
)
1463 return event
->pmu
->disable(event
);
1465 return event
->pmu
->stop(event
);
1468 static int perf_event_start(struct perf_event
*event
)
1470 if (!event
->pmu
->start
)
1471 return event
->pmu
->enable(event
);
1473 return event
->pmu
->start(event
);
1476 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1478 struct hw_perf_event
*hwc
= &event
->hw
;
1479 u64 period
, sample_period
;
1482 period
= perf_calculate_period(event
, nsec
, count
);
1484 delta
= (s64
)(period
- hwc
->sample_period
);
1485 delta
= (delta
+ 7) / 8; /* low pass filter */
1487 sample_period
= hwc
->sample_period
+ delta
;
1492 hwc
->sample_period
= sample_period
;
1494 if (atomic64_read(&hwc
->period_left
) > 8*sample_period
) {
1496 perf_event_stop(event
);
1497 atomic64_set(&hwc
->period_left
, 0);
1498 perf_event_start(event
);
1503 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
)
1505 struct perf_event
*event
;
1506 struct hw_perf_event
*hwc
;
1507 u64 interrupts
, now
;
1510 raw_spin_lock(&ctx
->lock
);
1511 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
1512 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1515 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1520 interrupts
= hwc
->interrupts
;
1521 hwc
->interrupts
= 0;
1524 * unthrottle events on the tick
1526 if (interrupts
== MAX_INTERRUPTS
) {
1527 perf_log_throttle(event
, 1);
1529 event
->pmu
->unthrottle(event
);
1533 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
1537 event
->pmu
->read(event
);
1538 now
= atomic64_read(&event
->count
);
1539 delta
= now
- hwc
->freq_count_stamp
;
1540 hwc
->freq_count_stamp
= now
;
1543 perf_adjust_period(event
, TICK_NSEC
, delta
);
1546 raw_spin_unlock(&ctx
->lock
);
1550 * Round-robin a context's events:
1552 static void rotate_ctx(struct perf_event_context
*ctx
)
1554 raw_spin_lock(&ctx
->lock
);
1556 /* Rotate the first entry last of non-pinned groups */
1557 list_rotate_left(&ctx
->flexible_groups
);
1559 raw_spin_unlock(&ctx
->lock
);
1562 void perf_event_task_tick(struct task_struct
*curr
)
1564 struct perf_cpu_context
*cpuctx
;
1565 struct perf_event_context
*ctx
;
1568 if (!atomic_read(&nr_events
))
1571 cpuctx
= &__get_cpu_var(perf_cpu_context
);
1572 if (cpuctx
->ctx
.nr_events
&&
1573 cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
1576 ctx
= curr
->perf_event_ctxp
;
1577 if (ctx
&& ctx
->nr_events
&& ctx
->nr_events
!= ctx
->nr_active
)
1580 perf_ctx_adjust_freq(&cpuctx
->ctx
);
1582 perf_ctx_adjust_freq(ctx
);
1588 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1590 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
1592 rotate_ctx(&cpuctx
->ctx
);
1596 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1598 task_ctx_sched_in(curr
, EVENT_FLEXIBLE
);
1602 static int event_enable_on_exec(struct perf_event
*event
,
1603 struct perf_event_context
*ctx
)
1605 if (!event
->attr
.enable_on_exec
)
1608 event
->attr
.enable_on_exec
= 0;
1609 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1612 __perf_event_mark_enabled(event
, ctx
);
1618 * Enable all of a task's events that have been marked enable-on-exec.
1619 * This expects task == current.
1621 static void perf_event_enable_on_exec(struct task_struct
*task
)
1623 struct perf_event_context
*ctx
;
1624 struct perf_event
*event
;
1625 unsigned long flags
;
1629 local_irq_save(flags
);
1630 ctx
= task
->perf_event_ctxp
;
1631 if (!ctx
|| !ctx
->nr_events
)
1634 __perf_event_task_sched_out(ctx
);
1636 raw_spin_lock(&ctx
->lock
);
1638 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1639 ret
= event_enable_on_exec(event
, ctx
);
1644 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1645 ret
= event_enable_on_exec(event
, ctx
);
1651 * Unclone this context if we enabled any event.
1656 raw_spin_unlock(&ctx
->lock
);
1658 perf_event_task_sched_in(task
);
1660 local_irq_restore(flags
);
1664 * Cross CPU call to read the hardware event
1666 static void __perf_event_read(void *info
)
1668 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1669 struct perf_event
*event
= info
;
1670 struct perf_event_context
*ctx
= event
->ctx
;
1673 * If this is a task context, we need to check whether it is
1674 * the current task context of this cpu. If not it has been
1675 * scheduled out before the smp call arrived. In that case
1676 * event->count would have been updated to a recent sample
1677 * when the event was scheduled out.
1679 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1682 raw_spin_lock(&ctx
->lock
);
1683 update_context_time(ctx
);
1684 update_event_times(event
);
1685 raw_spin_unlock(&ctx
->lock
);
1687 event
->pmu
->read(event
);
1690 static u64
perf_event_read(struct perf_event
*event
)
1693 * If event is enabled and currently active on a CPU, update the
1694 * value in the event structure:
1696 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1697 smp_call_function_single(event
->oncpu
,
1698 __perf_event_read
, event
, 1);
1699 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1700 struct perf_event_context
*ctx
= event
->ctx
;
1701 unsigned long flags
;
1703 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1704 update_context_time(ctx
);
1705 update_event_times(event
);
1706 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1709 return atomic64_read(&event
->count
);
1713 * Initialize the perf_event context in a task_struct:
1716 __perf_event_init_context(struct perf_event_context
*ctx
,
1717 struct task_struct
*task
)
1719 raw_spin_lock_init(&ctx
->lock
);
1720 mutex_init(&ctx
->mutex
);
1721 INIT_LIST_HEAD(&ctx
->pinned_groups
);
1722 INIT_LIST_HEAD(&ctx
->flexible_groups
);
1723 INIT_LIST_HEAD(&ctx
->event_list
);
1724 atomic_set(&ctx
->refcount
, 1);
1728 static struct perf_event_context
*find_get_context(pid_t pid
, int cpu
)
1730 struct perf_event_context
*ctx
;
1731 struct perf_cpu_context
*cpuctx
;
1732 struct task_struct
*task
;
1733 unsigned long flags
;
1736 if (pid
== -1 && cpu
!= -1) {
1737 /* Must be root to operate on a CPU event: */
1738 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
1739 return ERR_PTR(-EACCES
);
1741 if (cpu
< 0 || cpu
>= nr_cpumask_bits
)
1742 return ERR_PTR(-EINVAL
);
1745 * We could be clever and allow to attach a event to an
1746 * offline CPU and activate it when the CPU comes up, but
1749 if (!cpu_online(cpu
))
1750 return ERR_PTR(-ENODEV
);
1752 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1763 task
= find_task_by_vpid(pid
);
1765 get_task_struct(task
);
1769 return ERR_PTR(-ESRCH
);
1772 * Can't attach events to a dying task.
1775 if (task
->flags
& PF_EXITING
)
1778 /* Reuse ptrace permission checks for now. */
1780 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
1784 ctx
= perf_lock_task_context(task
, &flags
);
1787 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1791 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
1795 __perf_event_init_context(ctx
, task
);
1797 if (cmpxchg(&task
->perf_event_ctxp
, NULL
, ctx
)) {
1799 * We raced with some other task; use
1800 * the context they set.
1805 get_task_struct(task
);
1808 put_task_struct(task
);
1812 put_task_struct(task
);
1813 return ERR_PTR(err
);
1816 static void perf_event_free_filter(struct perf_event
*event
);
1818 static void free_event_rcu(struct rcu_head
*head
)
1820 struct perf_event
*event
;
1822 event
= container_of(head
, struct perf_event
, rcu_head
);
1824 put_pid_ns(event
->ns
);
1825 perf_event_free_filter(event
);
1829 static void perf_pending_sync(struct perf_event
*event
);
1831 static void free_event(struct perf_event
*event
)
1833 perf_pending_sync(event
);
1835 if (!event
->parent
) {
1836 atomic_dec(&nr_events
);
1837 if (event
->attr
.mmap
)
1838 atomic_dec(&nr_mmap_events
);
1839 if (event
->attr
.comm
)
1840 atomic_dec(&nr_comm_events
);
1841 if (event
->attr
.task
)
1842 atomic_dec(&nr_task_events
);
1845 if (event
->output
) {
1846 fput(event
->output
->filp
);
1847 event
->output
= NULL
;
1851 event
->destroy(event
);
1853 put_ctx(event
->ctx
);
1854 call_rcu(&event
->rcu_head
, free_event_rcu
);
1857 int perf_event_release_kernel(struct perf_event
*event
)
1859 struct perf_event_context
*ctx
= event
->ctx
;
1861 WARN_ON_ONCE(ctx
->parent_ctx
);
1862 mutex_lock(&ctx
->mutex
);
1863 perf_event_remove_from_context(event
);
1864 mutex_unlock(&ctx
->mutex
);
1866 mutex_lock(&event
->owner
->perf_event_mutex
);
1867 list_del_init(&event
->owner_entry
);
1868 mutex_unlock(&event
->owner
->perf_event_mutex
);
1869 put_task_struct(event
->owner
);
1875 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
1878 * Called when the last reference to the file is gone.
1880 static int perf_release(struct inode
*inode
, struct file
*file
)
1882 struct perf_event
*event
= file
->private_data
;
1884 file
->private_data
= NULL
;
1886 return perf_event_release_kernel(event
);
1889 static int perf_event_read_size(struct perf_event
*event
)
1891 int entry
= sizeof(u64
); /* value */
1895 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1896 size
+= sizeof(u64
);
1898 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1899 size
+= sizeof(u64
);
1901 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1902 entry
+= sizeof(u64
);
1904 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1905 nr
+= event
->group_leader
->nr_siblings
;
1906 size
+= sizeof(u64
);
1914 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
1916 struct perf_event
*child
;
1922 mutex_lock(&event
->child_mutex
);
1923 total
+= perf_event_read(event
);
1924 *enabled
+= event
->total_time_enabled
+
1925 atomic64_read(&event
->child_total_time_enabled
);
1926 *running
+= event
->total_time_running
+
1927 atomic64_read(&event
->child_total_time_running
);
1929 list_for_each_entry(child
, &event
->child_list
, child_list
) {
1930 total
+= perf_event_read(child
);
1931 *enabled
+= child
->total_time_enabled
;
1932 *running
+= child
->total_time_running
;
1934 mutex_unlock(&event
->child_mutex
);
1938 EXPORT_SYMBOL_GPL(perf_event_read_value
);
1940 static int perf_event_read_group(struct perf_event
*event
,
1941 u64 read_format
, char __user
*buf
)
1943 struct perf_event
*leader
= event
->group_leader
, *sub
;
1944 int n
= 0, size
= 0, ret
= -EFAULT
;
1945 struct perf_event_context
*ctx
= leader
->ctx
;
1947 u64 count
, enabled
, running
;
1949 mutex_lock(&ctx
->mutex
);
1950 count
= perf_event_read_value(leader
, &enabled
, &running
);
1952 values
[n
++] = 1 + leader
->nr_siblings
;
1953 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1954 values
[n
++] = enabled
;
1955 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1956 values
[n
++] = running
;
1957 values
[n
++] = count
;
1958 if (read_format
& PERF_FORMAT_ID
)
1959 values
[n
++] = primary_event_id(leader
);
1961 size
= n
* sizeof(u64
);
1963 if (copy_to_user(buf
, values
, size
))
1968 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
1971 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
1972 if (read_format
& PERF_FORMAT_ID
)
1973 values
[n
++] = primary_event_id(sub
);
1975 size
= n
* sizeof(u64
);
1977 if (copy_to_user(buf
+ ret
, values
, size
)) {
1985 mutex_unlock(&ctx
->mutex
);
1990 static int perf_event_read_one(struct perf_event
*event
,
1991 u64 read_format
, char __user
*buf
)
1993 u64 enabled
, running
;
1997 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
1998 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1999 values
[n
++] = enabled
;
2000 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2001 values
[n
++] = running
;
2002 if (read_format
& PERF_FORMAT_ID
)
2003 values
[n
++] = primary_event_id(event
);
2005 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2008 return n
* sizeof(u64
);
2012 * Read the performance event - simple non blocking version for now
2015 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2017 u64 read_format
= event
->attr
.read_format
;
2021 * Return end-of-file for a read on a event that is in
2022 * error state (i.e. because it was pinned but it couldn't be
2023 * scheduled on to the CPU at some point).
2025 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2028 if (count
< perf_event_read_size(event
))
2031 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2032 if (read_format
& PERF_FORMAT_GROUP
)
2033 ret
= perf_event_read_group(event
, read_format
, buf
);
2035 ret
= perf_event_read_one(event
, read_format
, buf
);
2041 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2043 struct perf_event
*event
= file
->private_data
;
2045 return perf_read_hw(event
, buf
, count
);
2048 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2050 struct perf_event
*event
= file
->private_data
;
2051 struct perf_mmap_data
*data
;
2052 unsigned int events
= POLL_HUP
;
2055 data
= rcu_dereference(event
->data
);
2057 events
= atomic_xchg(&data
->poll
, 0);
2060 poll_wait(file
, &event
->waitq
, wait
);
2065 static void perf_event_reset(struct perf_event
*event
)
2067 (void)perf_event_read(event
);
2068 atomic64_set(&event
->count
, 0);
2069 perf_event_update_userpage(event
);
2073 * Holding the top-level event's child_mutex means that any
2074 * descendant process that has inherited this event will block
2075 * in sync_child_event if it goes to exit, thus satisfying the
2076 * task existence requirements of perf_event_enable/disable.
2078 static void perf_event_for_each_child(struct perf_event
*event
,
2079 void (*func
)(struct perf_event
*))
2081 struct perf_event
*child
;
2083 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2084 mutex_lock(&event
->child_mutex
);
2086 list_for_each_entry(child
, &event
->child_list
, child_list
)
2088 mutex_unlock(&event
->child_mutex
);
2091 static void perf_event_for_each(struct perf_event
*event
,
2092 void (*func
)(struct perf_event
*))
2094 struct perf_event_context
*ctx
= event
->ctx
;
2095 struct perf_event
*sibling
;
2097 WARN_ON_ONCE(ctx
->parent_ctx
);
2098 mutex_lock(&ctx
->mutex
);
2099 event
= event
->group_leader
;
2101 perf_event_for_each_child(event
, func
);
2103 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
2104 perf_event_for_each_child(event
, func
);
2105 mutex_unlock(&ctx
->mutex
);
2108 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
2110 struct perf_event_context
*ctx
= event
->ctx
;
2115 if (!event
->attr
.sample_period
)
2118 size
= copy_from_user(&value
, arg
, sizeof(value
));
2119 if (size
!= sizeof(value
))
2125 raw_spin_lock_irq(&ctx
->lock
);
2126 if (event
->attr
.freq
) {
2127 if (value
> sysctl_perf_event_sample_rate
) {
2132 event
->attr
.sample_freq
= value
;
2134 event
->attr
.sample_period
= value
;
2135 event
->hw
.sample_period
= value
;
2138 raw_spin_unlock_irq(&ctx
->lock
);
2143 static int perf_event_set_output(struct perf_event
*event
, int output_fd
);
2144 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
2146 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2148 struct perf_event
*event
= file
->private_data
;
2149 void (*func
)(struct perf_event
*);
2153 case PERF_EVENT_IOC_ENABLE
:
2154 func
= perf_event_enable
;
2156 case PERF_EVENT_IOC_DISABLE
:
2157 func
= perf_event_disable
;
2159 case PERF_EVENT_IOC_RESET
:
2160 func
= perf_event_reset
;
2163 case PERF_EVENT_IOC_REFRESH
:
2164 return perf_event_refresh(event
, arg
);
2166 case PERF_EVENT_IOC_PERIOD
:
2167 return perf_event_period(event
, (u64 __user
*)arg
);
2169 case PERF_EVENT_IOC_SET_OUTPUT
:
2170 return perf_event_set_output(event
, arg
);
2172 case PERF_EVENT_IOC_SET_FILTER
:
2173 return perf_event_set_filter(event
, (void __user
*)arg
);
2179 if (flags
& PERF_IOC_FLAG_GROUP
)
2180 perf_event_for_each(event
, func
);
2182 perf_event_for_each_child(event
, func
);
2187 int perf_event_task_enable(void)
2189 struct perf_event
*event
;
2191 mutex_lock(¤t
->perf_event_mutex
);
2192 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2193 perf_event_for_each_child(event
, perf_event_enable
);
2194 mutex_unlock(¤t
->perf_event_mutex
);
2199 int perf_event_task_disable(void)
2201 struct perf_event
*event
;
2203 mutex_lock(¤t
->perf_event_mutex
);
2204 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2205 perf_event_for_each_child(event
, perf_event_disable
);
2206 mutex_unlock(¤t
->perf_event_mutex
);
2211 #ifndef PERF_EVENT_INDEX_OFFSET
2212 # define PERF_EVENT_INDEX_OFFSET 0
2215 static int perf_event_index(struct perf_event
*event
)
2217 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2220 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
2224 * Callers need to ensure there can be no nesting of this function, otherwise
2225 * the seqlock logic goes bad. We can not serialize this because the arch
2226 * code calls this from NMI context.
2228 void perf_event_update_userpage(struct perf_event
*event
)
2230 struct perf_event_mmap_page
*userpg
;
2231 struct perf_mmap_data
*data
;
2234 data
= rcu_dereference(event
->data
);
2238 userpg
= data
->user_page
;
2241 * Disable preemption so as to not let the corresponding user-space
2242 * spin too long if we get preempted.
2247 userpg
->index
= perf_event_index(event
);
2248 userpg
->offset
= atomic64_read(&event
->count
);
2249 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2250 userpg
->offset
-= atomic64_read(&event
->hw
.prev_count
);
2252 userpg
->time_enabled
= event
->total_time_enabled
+
2253 atomic64_read(&event
->child_total_time_enabled
);
2255 userpg
->time_running
= event
->total_time_running
+
2256 atomic64_read(&event
->child_total_time_running
);
2265 static unsigned long perf_data_size(struct perf_mmap_data
*data
)
2267 return data
->nr_pages
<< (PAGE_SHIFT
+ data
->data_order
);
2270 #ifndef CONFIG_PERF_USE_VMALLOC
2273 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
2276 static struct page
*
2277 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2279 if (pgoff
> data
->nr_pages
)
2283 return virt_to_page(data
->user_page
);
2285 return virt_to_page(data
->data_pages
[pgoff
- 1]);
2288 static struct perf_mmap_data
*
2289 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2291 struct perf_mmap_data
*data
;
2295 WARN_ON(atomic_read(&event
->mmap_count
));
2297 size
= sizeof(struct perf_mmap_data
);
2298 size
+= nr_pages
* sizeof(void *);
2300 data
= kzalloc(size
, GFP_KERNEL
);
2304 data
->user_page
= (void *)get_zeroed_page(GFP_KERNEL
);
2305 if (!data
->user_page
)
2306 goto fail_user_page
;
2308 for (i
= 0; i
< nr_pages
; i
++) {
2309 data
->data_pages
[i
] = (void *)get_zeroed_page(GFP_KERNEL
);
2310 if (!data
->data_pages
[i
])
2311 goto fail_data_pages
;
2314 data
->data_order
= 0;
2315 data
->nr_pages
= nr_pages
;
2320 for (i
--; i
>= 0; i
--)
2321 free_page((unsigned long)data
->data_pages
[i
]);
2323 free_page((unsigned long)data
->user_page
);
2332 static void perf_mmap_free_page(unsigned long addr
)
2334 struct page
*page
= virt_to_page((void *)addr
);
2336 page
->mapping
= NULL
;
2340 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2344 perf_mmap_free_page((unsigned long)data
->user_page
);
2345 for (i
= 0; i
< data
->nr_pages
; i
++)
2346 perf_mmap_free_page((unsigned long)data
->data_pages
[i
]);
2353 * Back perf_mmap() with vmalloc memory.
2355 * Required for architectures that have d-cache aliasing issues.
2358 static struct page
*
2359 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2361 if (pgoff
> (1UL << data
->data_order
))
2364 return vmalloc_to_page((void *)data
->user_page
+ pgoff
* PAGE_SIZE
);
2367 static void perf_mmap_unmark_page(void *addr
)
2369 struct page
*page
= vmalloc_to_page(addr
);
2371 page
->mapping
= NULL
;
2374 static void perf_mmap_data_free_work(struct work_struct
*work
)
2376 struct perf_mmap_data
*data
;
2380 data
= container_of(work
, struct perf_mmap_data
, work
);
2381 nr
= 1 << data
->data_order
;
2383 base
= data
->user_page
;
2384 for (i
= 0; i
< nr
+ 1; i
++)
2385 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
2391 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2393 schedule_work(&data
->work
);
2396 static struct perf_mmap_data
*
2397 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2399 struct perf_mmap_data
*data
;
2403 WARN_ON(atomic_read(&event
->mmap_count
));
2405 size
= sizeof(struct perf_mmap_data
);
2406 size
+= sizeof(void *);
2408 data
= kzalloc(size
, GFP_KERNEL
);
2412 INIT_WORK(&data
->work
, perf_mmap_data_free_work
);
2414 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
2418 data
->user_page
= all_buf
;
2419 data
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
2420 data
->data_order
= ilog2(nr_pages
);
2434 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
2436 struct perf_event
*event
= vma
->vm_file
->private_data
;
2437 struct perf_mmap_data
*data
;
2438 int ret
= VM_FAULT_SIGBUS
;
2440 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
2441 if (vmf
->pgoff
== 0)
2447 data
= rcu_dereference(event
->data
);
2451 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
2454 vmf
->page
= perf_mmap_to_page(data
, vmf
->pgoff
);
2458 get_page(vmf
->page
);
2459 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
2460 vmf
->page
->index
= vmf
->pgoff
;
2470 perf_mmap_data_init(struct perf_event
*event
, struct perf_mmap_data
*data
)
2472 long max_size
= perf_data_size(data
);
2474 atomic_set(&data
->lock
, -1);
2476 if (event
->attr
.watermark
) {
2477 data
->watermark
= min_t(long, max_size
,
2478 event
->attr
.wakeup_watermark
);
2481 if (!data
->watermark
)
2482 data
->watermark
= max_size
/ 2;
2485 rcu_assign_pointer(event
->data
, data
);
2488 static void perf_mmap_data_free_rcu(struct rcu_head
*rcu_head
)
2490 struct perf_mmap_data
*data
;
2492 data
= container_of(rcu_head
, struct perf_mmap_data
, rcu_head
);
2493 perf_mmap_data_free(data
);
2496 static void perf_mmap_data_release(struct perf_event
*event
)
2498 struct perf_mmap_data
*data
= event
->data
;
2500 WARN_ON(atomic_read(&event
->mmap_count
));
2502 rcu_assign_pointer(event
->data
, NULL
);
2503 call_rcu(&data
->rcu_head
, perf_mmap_data_free_rcu
);
2506 static void perf_mmap_open(struct vm_area_struct
*vma
)
2508 struct perf_event
*event
= vma
->vm_file
->private_data
;
2510 atomic_inc(&event
->mmap_count
);
2513 static void perf_mmap_close(struct vm_area_struct
*vma
)
2515 struct perf_event
*event
= vma
->vm_file
->private_data
;
2517 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2518 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
2519 unsigned long size
= perf_data_size(event
->data
);
2520 struct user_struct
*user
= current_user();
2522 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
2523 vma
->vm_mm
->locked_vm
-= event
->data
->nr_locked
;
2524 perf_mmap_data_release(event
);
2525 mutex_unlock(&event
->mmap_mutex
);
2529 static const struct vm_operations_struct perf_mmap_vmops
= {
2530 .open
= perf_mmap_open
,
2531 .close
= perf_mmap_close
,
2532 .fault
= perf_mmap_fault
,
2533 .page_mkwrite
= perf_mmap_fault
,
2536 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
2538 struct perf_event
*event
= file
->private_data
;
2539 unsigned long user_locked
, user_lock_limit
;
2540 struct user_struct
*user
= current_user();
2541 unsigned long locked
, lock_limit
;
2542 struct perf_mmap_data
*data
;
2543 unsigned long vma_size
;
2544 unsigned long nr_pages
;
2545 long user_extra
, extra
;
2548 if (!(vma
->vm_flags
& VM_SHARED
))
2551 vma_size
= vma
->vm_end
- vma
->vm_start
;
2552 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
2555 * If we have data pages ensure they're a power-of-two number, so we
2556 * can do bitmasks instead of modulo.
2558 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
2561 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
2564 if (vma
->vm_pgoff
!= 0)
2567 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2568 mutex_lock(&event
->mmap_mutex
);
2569 if (event
->output
) {
2574 if (atomic_inc_not_zero(&event
->mmap_count
)) {
2575 if (nr_pages
!= event
->data
->nr_pages
)
2580 user_extra
= nr_pages
+ 1;
2581 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
2584 * Increase the limit linearly with more CPUs:
2586 user_lock_limit
*= num_online_cpus();
2588 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
2591 if (user_locked
> user_lock_limit
)
2592 extra
= user_locked
- user_lock_limit
;
2594 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
2595 lock_limit
>>= PAGE_SHIFT
;
2596 locked
= vma
->vm_mm
->locked_vm
+ extra
;
2598 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
2599 !capable(CAP_IPC_LOCK
)) {
2604 WARN_ON(event
->data
);
2606 data
= perf_mmap_data_alloc(event
, nr_pages
);
2612 perf_mmap_data_init(event
, data
);
2614 atomic_set(&event
->mmap_count
, 1);
2615 atomic_long_add(user_extra
, &user
->locked_vm
);
2616 vma
->vm_mm
->locked_vm
+= extra
;
2617 event
->data
->nr_locked
= extra
;
2618 if (vma
->vm_flags
& VM_WRITE
)
2619 event
->data
->writable
= 1;
2622 mutex_unlock(&event
->mmap_mutex
);
2624 vma
->vm_flags
|= VM_RESERVED
;
2625 vma
->vm_ops
= &perf_mmap_vmops
;
2630 static int perf_fasync(int fd
, struct file
*filp
, int on
)
2632 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
2633 struct perf_event
*event
= filp
->private_data
;
2636 mutex_lock(&inode
->i_mutex
);
2637 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
2638 mutex_unlock(&inode
->i_mutex
);
2646 static const struct file_operations perf_fops
= {
2647 .release
= perf_release
,
2650 .unlocked_ioctl
= perf_ioctl
,
2651 .compat_ioctl
= perf_ioctl
,
2653 .fasync
= perf_fasync
,
2659 * If there's data, ensure we set the poll() state and publish everything
2660 * to user-space before waking everybody up.
2663 void perf_event_wakeup(struct perf_event
*event
)
2665 wake_up_all(&event
->waitq
);
2667 if (event
->pending_kill
) {
2668 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
2669 event
->pending_kill
= 0;
2676 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
2678 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
2679 * single linked list and use cmpxchg() to add entries lockless.
2682 static void perf_pending_event(struct perf_pending_entry
*entry
)
2684 struct perf_event
*event
= container_of(entry
,
2685 struct perf_event
, pending
);
2687 if (event
->pending_disable
) {
2688 event
->pending_disable
= 0;
2689 __perf_event_disable(event
);
2692 if (event
->pending_wakeup
) {
2693 event
->pending_wakeup
= 0;
2694 perf_event_wakeup(event
);
2698 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
2700 static DEFINE_PER_CPU(struct perf_pending_entry
*, perf_pending_head
) = {
2704 static void perf_pending_queue(struct perf_pending_entry
*entry
,
2705 void (*func
)(struct perf_pending_entry
*))
2707 struct perf_pending_entry
**head
;
2709 if (cmpxchg(&entry
->next
, NULL
, PENDING_TAIL
) != NULL
)
2714 head
= &get_cpu_var(perf_pending_head
);
2717 entry
->next
= *head
;
2718 } while (cmpxchg(head
, entry
->next
, entry
) != entry
->next
);
2720 set_perf_event_pending();
2722 put_cpu_var(perf_pending_head
);
2725 static int __perf_pending_run(void)
2727 struct perf_pending_entry
*list
;
2730 list
= xchg(&__get_cpu_var(perf_pending_head
), PENDING_TAIL
);
2731 while (list
!= PENDING_TAIL
) {
2732 void (*func
)(struct perf_pending_entry
*);
2733 struct perf_pending_entry
*entry
= list
;
2740 * Ensure we observe the unqueue before we issue the wakeup,
2741 * so that we won't be waiting forever.
2742 * -- see perf_not_pending().
2753 static inline int perf_not_pending(struct perf_event
*event
)
2756 * If we flush on whatever cpu we run, there is a chance we don't
2760 __perf_pending_run();
2764 * Ensure we see the proper queue state before going to sleep
2765 * so that we do not miss the wakeup. -- see perf_pending_handle()
2768 return event
->pending
.next
== NULL
;
2771 static void perf_pending_sync(struct perf_event
*event
)
2773 wait_event(event
->waitq
, perf_not_pending(event
));
2776 void perf_event_do_pending(void)
2778 __perf_pending_run();
2782 * Callchain support -- arch specific
2785 __weak
struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2790 #ifdef CONFIG_EVENT_TRACING
2792 void perf_arch_fetch_caller_regs(struct pt_regs
*regs
, unsigned long ip
, int skip
)
2800 static bool perf_output_space(struct perf_mmap_data
*data
, unsigned long tail
,
2801 unsigned long offset
, unsigned long head
)
2805 if (!data
->writable
)
2808 mask
= perf_data_size(data
) - 1;
2810 offset
= (offset
- tail
) & mask
;
2811 head
= (head
- tail
) & mask
;
2813 if ((int)(head
- offset
) < 0)
2819 static void perf_output_wakeup(struct perf_output_handle
*handle
)
2821 atomic_set(&handle
->data
->poll
, POLL_IN
);
2824 handle
->event
->pending_wakeup
= 1;
2825 perf_pending_queue(&handle
->event
->pending
,
2826 perf_pending_event
);
2828 perf_event_wakeup(handle
->event
);
2832 * Curious locking construct.
2834 * We need to ensure a later event_id doesn't publish a head when a former
2835 * event_id isn't done writing. However since we need to deal with NMIs we
2836 * cannot fully serialize things.
2838 * What we do is serialize between CPUs so we only have to deal with NMI
2839 * nesting on a single CPU.
2841 * We only publish the head (and generate a wakeup) when the outer-most
2842 * event_id completes.
2844 static void perf_output_lock(struct perf_output_handle
*handle
)
2846 struct perf_mmap_data
*data
= handle
->data
;
2847 int cur
, cpu
= get_cpu();
2852 cur
= atomic_cmpxchg(&data
->lock
, -1, cpu
);
2864 static void perf_output_unlock(struct perf_output_handle
*handle
)
2866 struct perf_mmap_data
*data
= handle
->data
;
2870 data
->done_head
= data
->head
;
2872 if (!handle
->locked
)
2877 * The xchg implies a full barrier that ensures all writes are done
2878 * before we publish the new head, matched by a rmb() in userspace when
2879 * reading this position.
2881 while ((head
= atomic_long_xchg(&data
->done_head
, 0)))
2882 data
->user_page
->data_head
= head
;
2885 * NMI can happen here, which means we can miss a done_head update.
2888 cpu
= atomic_xchg(&data
->lock
, -1);
2889 WARN_ON_ONCE(cpu
!= smp_processor_id());
2892 * Therefore we have to validate we did not indeed do so.
2894 if (unlikely(atomic_long_read(&data
->done_head
))) {
2896 * Since we had it locked, we can lock it again.
2898 while (atomic_cmpxchg(&data
->lock
, -1, cpu
) != -1)
2904 if (atomic_xchg(&data
->wakeup
, 0))
2905 perf_output_wakeup(handle
);
2910 void perf_output_copy(struct perf_output_handle
*handle
,
2911 const void *buf
, unsigned int len
)
2913 unsigned int pages_mask
;
2914 unsigned long offset
;
2918 offset
= handle
->offset
;
2919 pages_mask
= handle
->data
->nr_pages
- 1;
2920 pages
= handle
->data
->data_pages
;
2923 unsigned long page_offset
;
2924 unsigned long page_size
;
2927 nr
= (offset
>> PAGE_SHIFT
) & pages_mask
;
2928 page_size
= 1UL << (handle
->data
->data_order
+ PAGE_SHIFT
);
2929 page_offset
= offset
& (page_size
- 1);
2930 size
= min_t(unsigned int, page_size
- page_offset
, len
);
2932 memcpy(pages
[nr
] + page_offset
, buf
, size
);
2939 handle
->offset
= offset
;
2942 * Check we didn't copy past our reservation window, taking the
2943 * possible unsigned int wrap into account.
2945 WARN_ON_ONCE(((long)(handle
->head
- handle
->offset
)) < 0);
2948 int perf_output_begin(struct perf_output_handle
*handle
,
2949 struct perf_event
*event
, unsigned int size
,
2950 int nmi
, int sample
)
2952 struct perf_event
*output_event
;
2953 struct perf_mmap_data
*data
;
2954 unsigned long tail
, offset
, head
;
2957 struct perf_event_header header
;
2964 * For inherited events we send all the output towards the parent.
2967 event
= event
->parent
;
2969 output_event
= rcu_dereference(event
->output
);
2971 event
= output_event
;
2973 data
= rcu_dereference(event
->data
);
2977 handle
->data
= data
;
2978 handle
->event
= event
;
2980 handle
->sample
= sample
;
2982 if (!data
->nr_pages
)
2985 have_lost
= atomic_read(&data
->lost
);
2987 size
+= sizeof(lost_event
);
2989 perf_output_lock(handle
);
2993 * Userspace could choose to issue a mb() before updating the
2994 * tail pointer. So that all reads will be completed before the
2997 tail
= ACCESS_ONCE(data
->user_page
->data_tail
);
2999 offset
= head
= atomic_long_read(&data
->head
);
3001 if (unlikely(!perf_output_space(data
, tail
, offset
, head
)))
3003 } while (atomic_long_cmpxchg(&data
->head
, offset
, head
) != offset
);
3005 handle
->offset
= offset
;
3006 handle
->head
= head
;
3008 if (head
- tail
> data
->watermark
)
3009 atomic_set(&data
->wakeup
, 1);
3012 lost_event
.header
.type
= PERF_RECORD_LOST
;
3013 lost_event
.header
.misc
= 0;
3014 lost_event
.header
.size
= sizeof(lost_event
);
3015 lost_event
.id
= event
->id
;
3016 lost_event
.lost
= atomic_xchg(&data
->lost
, 0);
3018 perf_output_put(handle
, lost_event
);
3024 atomic_inc(&data
->lost
);
3025 perf_output_unlock(handle
);
3032 void perf_output_end(struct perf_output_handle
*handle
)
3034 struct perf_event
*event
= handle
->event
;
3035 struct perf_mmap_data
*data
= handle
->data
;
3037 int wakeup_events
= event
->attr
.wakeup_events
;
3039 if (handle
->sample
&& wakeup_events
) {
3040 int events
= atomic_inc_return(&data
->events
);
3041 if (events
>= wakeup_events
) {
3042 atomic_sub(wakeup_events
, &data
->events
);
3043 atomic_set(&data
->wakeup
, 1);
3047 perf_output_unlock(handle
);
3051 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
3054 * only top level events have the pid namespace they were created in
3057 event
= event
->parent
;
3059 return task_tgid_nr_ns(p
, event
->ns
);
3062 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
3065 * only top level events have the pid namespace they were created in
3068 event
= event
->parent
;
3070 return task_pid_nr_ns(p
, event
->ns
);
3073 static void perf_output_read_one(struct perf_output_handle
*handle
,
3074 struct perf_event
*event
)
3076 u64 read_format
= event
->attr
.read_format
;
3080 values
[n
++] = atomic64_read(&event
->count
);
3081 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3082 values
[n
++] = event
->total_time_enabled
+
3083 atomic64_read(&event
->child_total_time_enabled
);
3085 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3086 values
[n
++] = event
->total_time_running
+
3087 atomic64_read(&event
->child_total_time_running
);
3089 if (read_format
& PERF_FORMAT_ID
)
3090 values
[n
++] = primary_event_id(event
);
3092 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3096 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3098 static void perf_output_read_group(struct perf_output_handle
*handle
,
3099 struct perf_event
*event
)
3101 struct perf_event
*leader
= event
->group_leader
, *sub
;
3102 u64 read_format
= event
->attr
.read_format
;
3106 values
[n
++] = 1 + leader
->nr_siblings
;
3108 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3109 values
[n
++] = leader
->total_time_enabled
;
3111 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3112 values
[n
++] = leader
->total_time_running
;
3114 if (leader
!= event
)
3115 leader
->pmu
->read(leader
);
3117 values
[n
++] = atomic64_read(&leader
->count
);
3118 if (read_format
& PERF_FORMAT_ID
)
3119 values
[n
++] = primary_event_id(leader
);
3121 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3123 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3127 sub
->pmu
->read(sub
);
3129 values
[n
++] = atomic64_read(&sub
->count
);
3130 if (read_format
& PERF_FORMAT_ID
)
3131 values
[n
++] = primary_event_id(sub
);
3133 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3137 static void perf_output_read(struct perf_output_handle
*handle
,
3138 struct perf_event
*event
)
3140 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3141 perf_output_read_group(handle
, event
);
3143 perf_output_read_one(handle
, event
);
3146 void perf_output_sample(struct perf_output_handle
*handle
,
3147 struct perf_event_header
*header
,
3148 struct perf_sample_data
*data
,
3149 struct perf_event
*event
)
3151 u64 sample_type
= data
->type
;
3153 perf_output_put(handle
, *header
);
3155 if (sample_type
& PERF_SAMPLE_IP
)
3156 perf_output_put(handle
, data
->ip
);
3158 if (sample_type
& PERF_SAMPLE_TID
)
3159 perf_output_put(handle
, data
->tid_entry
);
3161 if (sample_type
& PERF_SAMPLE_TIME
)
3162 perf_output_put(handle
, data
->time
);
3164 if (sample_type
& PERF_SAMPLE_ADDR
)
3165 perf_output_put(handle
, data
->addr
);
3167 if (sample_type
& PERF_SAMPLE_ID
)
3168 perf_output_put(handle
, data
->id
);
3170 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3171 perf_output_put(handle
, data
->stream_id
);
3173 if (sample_type
& PERF_SAMPLE_CPU
)
3174 perf_output_put(handle
, data
->cpu_entry
);
3176 if (sample_type
& PERF_SAMPLE_PERIOD
)
3177 perf_output_put(handle
, data
->period
);
3179 if (sample_type
& PERF_SAMPLE_READ
)
3180 perf_output_read(handle
, event
);
3182 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3183 if (data
->callchain
) {
3186 if (data
->callchain
)
3187 size
+= data
->callchain
->nr
;
3189 size
*= sizeof(u64
);
3191 perf_output_copy(handle
, data
->callchain
, size
);
3194 perf_output_put(handle
, nr
);
3198 if (sample_type
& PERF_SAMPLE_RAW
) {
3200 perf_output_put(handle
, data
->raw
->size
);
3201 perf_output_copy(handle
, data
->raw
->data
,
3208 .size
= sizeof(u32
),
3211 perf_output_put(handle
, raw
);
3216 void perf_prepare_sample(struct perf_event_header
*header
,
3217 struct perf_sample_data
*data
,
3218 struct perf_event
*event
,
3219 struct pt_regs
*regs
)
3221 u64 sample_type
= event
->attr
.sample_type
;
3223 data
->type
= sample_type
;
3225 header
->type
= PERF_RECORD_SAMPLE
;
3226 header
->size
= sizeof(*header
);
3229 header
->misc
|= perf_misc_flags(regs
);
3231 if (sample_type
& PERF_SAMPLE_IP
) {
3232 data
->ip
= perf_instruction_pointer(regs
);
3234 header
->size
+= sizeof(data
->ip
);
3237 if (sample_type
& PERF_SAMPLE_TID
) {
3238 /* namespace issues */
3239 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3240 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3242 header
->size
+= sizeof(data
->tid_entry
);
3245 if (sample_type
& PERF_SAMPLE_TIME
) {
3246 data
->time
= perf_clock();
3248 header
->size
+= sizeof(data
->time
);
3251 if (sample_type
& PERF_SAMPLE_ADDR
)
3252 header
->size
+= sizeof(data
->addr
);
3254 if (sample_type
& PERF_SAMPLE_ID
) {
3255 data
->id
= primary_event_id(event
);
3257 header
->size
+= sizeof(data
->id
);
3260 if (sample_type
& PERF_SAMPLE_STREAM_ID
) {
3261 data
->stream_id
= event
->id
;
3263 header
->size
+= sizeof(data
->stream_id
);
3266 if (sample_type
& PERF_SAMPLE_CPU
) {
3267 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3268 data
->cpu_entry
.reserved
= 0;
3270 header
->size
+= sizeof(data
->cpu_entry
);
3273 if (sample_type
& PERF_SAMPLE_PERIOD
)
3274 header
->size
+= sizeof(data
->period
);
3276 if (sample_type
& PERF_SAMPLE_READ
)
3277 header
->size
+= perf_event_read_size(event
);
3279 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3282 data
->callchain
= perf_callchain(regs
);
3284 if (data
->callchain
)
3285 size
+= data
->callchain
->nr
;
3287 header
->size
+= size
* sizeof(u64
);
3290 if (sample_type
& PERF_SAMPLE_RAW
) {
3291 int size
= sizeof(u32
);
3294 size
+= data
->raw
->size
;
3296 size
+= sizeof(u32
);
3298 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3299 header
->size
+= size
;
3303 static void perf_event_output(struct perf_event
*event
, int nmi
,
3304 struct perf_sample_data
*data
,
3305 struct pt_regs
*regs
)
3307 struct perf_output_handle handle
;
3308 struct perf_event_header header
;
3310 perf_prepare_sample(&header
, data
, event
, regs
);
3312 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
3315 perf_output_sample(&handle
, &header
, data
, event
);
3317 perf_output_end(&handle
);
3324 struct perf_read_event
{
3325 struct perf_event_header header
;
3332 perf_event_read_event(struct perf_event
*event
,
3333 struct task_struct
*task
)
3335 struct perf_output_handle handle
;
3336 struct perf_read_event read_event
= {
3338 .type
= PERF_RECORD_READ
,
3340 .size
= sizeof(read_event
) + perf_event_read_size(event
),
3342 .pid
= perf_event_pid(event
, task
),
3343 .tid
= perf_event_tid(event
, task
),
3347 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
3351 perf_output_put(&handle
, read_event
);
3352 perf_output_read(&handle
, event
);
3354 perf_output_end(&handle
);
3358 * task tracking -- fork/exit
3360 * enabled by: attr.comm | attr.mmap | attr.task
3363 struct perf_task_event
{
3364 struct task_struct
*task
;
3365 struct perf_event_context
*task_ctx
;
3368 struct perf_event_header header
;
3378 static void perf_event_task_output(struct perf_event
*event
,
3379 struct perf_task_event
*task_event
)
3381 struct perf_output_handle handle
;
3383 struct task_struct
*task
= task_event
->task
;
3386 size
= task_event
->event_id
.header
.size
;
3387 ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3392 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
3393 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
3395 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
3396 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
3398 perf_output_put(&handle
, task_event
->event_id
);
3400 perf_output_end(&handle
);
3403 static int perf_event_task_match(struct perf_event
*event
)
3405 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3408 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3411 if (event
->attr
.comm
|| event
->attr
.mmap
|| event
->attr
.task
)
3417 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
3418 struct perf_task_event
*task_event
)
3420 struct perf_event
*event
;
3422 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3423 if (perf_event_task_match(event
))
3424 perf_event_task_output(event
, task_event
);
3428 static void perf_event_task_event(struct perf_task_event
*task_event
)
3430 struct perf_cpu_context
*cpuctx
;
3431 struct perf_event_context
*ctx
= task_event
->task_ctx
;
3434 cpuctx
= &get_cpu_var(perf_cpu_context
);
3435 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
3437 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3439 perf_event_task_ctx(ctx
, task_event
);
3440 put_cpu_var(perf_cpu_context
);
3444 static void perf_event_task(struct task_struct
*task
,
3445 struct perf_event_context
*task_ctx
,
3448 struct perf_task_event task_event
;
3450 if (!atomic_read(&nr_comm_events
) &&
3451 !atomic_read(&nr_mmap_events
) &&
3452 !atomic_read(&nr_task_events
))
3455 task_event
= (struct perf_task_event
){
3457 .task_ctx
= task_ctx
,
3460 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
3462 .size
= sizeof(task_event
.event_id
),
3468 .time
= perf_clock(),
3472 perf_event_task_event(&task_event
);
3475 void perf_event_fork(struct task_struct
*task
)
3477 perf_event_task(task
, NULL
, 1);
3484 struct perf_comm_event
{
3485 struct task_struct
*task
;
3490 struct perf_event_header header
;
3497 static void perf_event_comm_output(struct perf_event
*event
,
3498 struct perf_comm_event
*comm_event
)
3500 struct perf_output_handle handle
;
3501 int size
= comm_event
->event_id
.header
.size
;
3502 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3507 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
3508 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
3510 perf_output_put(&handle
, comm_event
->event_id
);
3511 perf_output_copy(&handle
, comm_event
->comm
,
3512 comm_event
->comm_size
);
3513 perf_output_end(&handle
);
3516 static int perf_event_comm_match(struct perf_event
*event
)
3518 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3521 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3524 if (event
->attr
.comm
)
3530 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
3531 struct perf_comm_event
*comm_event
)
3533 struct perf_event
*event
;
3535 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3536 if (perf_event_comm_match(event
))
3537 perf_event_comm_output(event
, comm_event
);
3541 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
3543 struct perf_cpu_context
*cpuctx
;
3544 struct perf_event_context
*ctx
;
3546 char comm
[TASK_COMM_LEN
];
3548 memset(comm
, 0, sizeof(comm
));
3549 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
3550 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
3552 comm_event
->comm
= comm
;
3553 comm_event
->comm_size
= size
;
3555 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
3558 cpuctx
= &get_cpu_var(perf_cpu_context
);
3559 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
3560 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3562 perf_event_comm_ctx(ctx
, comm_event
);
3563 put_cpu_var(perf_cpu_context
);
3567 void perf_event_comm(struct task_struct
*task
)
3569 struct perf_comm_event comm_event
;
3571 if (task
->perf_event_ctxp
)
3572 perf_event_enable_on_exec(task
);
3574 if (!atomic_read(&nr_comm_events
))
3577 comm_event
= (struct perf_comm_event
){
3583 .type
= PERF_RECORD_COMM
,
3592 perf_event_comm_event(&comm_event
);
3599 struct perf_mmap_event
{
3600 struct vm_area_struct
*vma
;
3602 const char *file_name
;
3606 struct perf_event_header header
;
3616 static void perf_event_mmap_output(struct perf_event
*event
,
3617 struct perf_mmap_event
*mmap_event
)
3619 struct perf_output_handle handle
;
3620 int size
= mmap_event
->event_id
.header
.size
;
3621 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3626 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
3627 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
3629 perf_output_put(&handle
, mmap_event
->event_id
);
3630 perf_output_copy(&handle
, mmap_event
->file_name
,
3631 mmap_event
->file_size
);
3632 perf_output_end(&handle
);
3635 static int perf_event_mmap_match(struct perf_event
*event
,
3636 struct perf_mmap_event
*mmap_event
)
3638 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3641 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3644 if (event
->attr
.mmap
)
3650 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
3651 struct perf_mmap_event
*mmap_event
)
3653 struct perf_event
*event
;
3655 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3656 if (perf_event_mmap_match(event
, mmap_event
))
3657 perf_event_mmap_output(event
, mmap_event
);
3661 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
3663 struct perf_cpu_context
*cpuctx
;
3664 struct perf_event_context
*ctx
;
3665 struct vm_area_struct
*vma
= mmap_event
->vma
;
3666 struct file
*file
= vma
->vm_file
;
3672 memset(tmp
, 0, sizeof(tmp
));
3676 * d_path works from the end of the buffer backwards, so we
3677 * need to add enough zero bytes after the string to handle
3678 * the 64bit alignment we do later.
3680 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
3682 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
3685 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
3687 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
3691 if (arch_vma_name(mmap_event
->vma
)) {
3692 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
3698 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
3702 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
3707 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
3709 mmap_event
->file_name
= name
;
3710 mmap_event
->file_size
= size
;
3712 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
3715 cpuctx
= &get_cpu_var(perf_cpu_context
);
3716 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
);
3717 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3719 perf_event_mmap_ctx(ctx
, mmap_event
);
3720 put_cpu_var(perf_cpu_context
);
3726 void __perf_event_mmap(struct vm_area_struct
*vma
)
3728 struct perf_mmap_event mmap_event
;
3730 if (!atomic_read(&nr_mmap_events
))
3733 mmap_event
= (struct perf_mmap_event
){
3739 .type
= PERF_RECORD_MMAP
,
3745 .start
= vma
->vm_start
,
3746 .len
= vma
->vm_end
- vma
->vm_start
,
3747 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
3751 perf_event_mmap_event(&mmap_event
);
3755 * IRQ throttle logging
3758 static void perf_log_throttle(struct perf_event
*event
, int enable
)
3760 struct perf_output_handle handle
;
3764 struct perf_event_header header
;
3768 } throttle_event
= {
3770 .type
= PERF_RECORD_THROTTLE
,
3772 .size
= sizeof(throttle_event
),
3774 .time
= perf_clock(),
3775 .id
= primary_event_id(event
),
3776 .stream_id
= event
->id
,
3780 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
3782 ret
= perf_output_begin(&handle
, event
, sizeof(throttle_event
), 1, 0);
3786 perf_output_put(&handle
, throttle_event
);
3787 perf_output_end(&handle
);
3791 * Generic event overflow handling, sampling.
3794 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
3795 int throttle
, struct perf_sample_data
*data
,
3796 struct pt_regs
*regs
)
3798 int events
= atomic_read(&event
->event_limit
);
3799 struct hw_perf_event
*hwc
= &event
->hw
;
3802 throttle
= (throttle
&& event
->pmu
->unthrottle
!= NULL
);
3807 if (hwc
->interrupts
!= MAX_INTERRUPTS
) {
3809 if (HZ
* hwc
->interrupts
>
3810 (u64
)sysctl_perf_event_sample_rate
) {
3811 hwc
->interrupts
= MAX_INTERRUPTS
;
3812 perf_log_throttle(event
, 0);
3817 * Keep re-disabling events even though on the previous
3818 * pass we disabled it - just in case we raced with a
3819 * sched-in and the event got enabled again:
3825 if (event
->attr
.freq
) {
3826 u64 now
= perf_clock();
3827 s64 delta
= now
- hwc
->freq_time_stamp
;
3829 hwc
->freq_time_stamp
= now
;
3831 if (delta
> 0 && delta
< 2*TICK_NSEC
)
3832 perf_adjust_period(event
, delta
, hwc
->last_period
);
3836 * XXX event_limit might not quite work as expected on inherited
3840 event
->pending_kill
= POLL_IN
;
3841 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
3843 event
->pending_kill
= POLL_HUP
;
3845 event
->pending_disable
= 1;
3846 perf_pending_queue(&event
->pending
,
3847 perf_pending_event
);
3849 perf_event_disable(event
);
3852 if (event
->overflow_handler
)
3853 event
->overflow_handler(event
, nmi
, data
, regs
);
3855 perf_event_output(event
, nmi
, data
, regs
);
3860 int perf_event_overflow(struct perf_event
*event
, int nmi
,
3861 struct perf_sample_data
*data
,
3862 struct pt_regs
*regs
)
3864 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
3868 * Generic software event infrastructure
3872 * We directly increment event->count and keep a second value in
3873 * event->hw.period_left to count intervals. This period event
3874 * is kept in the range [-sample_period, 0] so that we can use the
3878 static u64
perf_swevent_set_period(struct perf_event
*event
)
3880 struct hw_perf_event
*hwc
= &event
->hw
;
3881 u64 period
= hwc
->last_period
;
3885 hwc
->last_period
= hwc
->sample_period
;
3888 old
= val
= atomic64_read(&hwc
->period_left
);
3892 nr
= div64_u64(period
+ val
, period
);
3893 offset
= nr
* period
;
3895 if (atomic64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
3901 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
3902 int nmi
, struct perf_sample_data
*data
,
3903 struct pt_regs
*regs
)
3905 struct hw_perf_event
*hwc
= &event
->hw
;
3908 data
->period
= event
->hw
.last_period
;
3910 overflow
= perf_swevent_set_period(event
);
3912 if (hwc
->interrupts
== MAX_INTERRUPTS
)
3915 for (; overflow
; overflow
--) {
3916 if (__perf_event_overflow(event
, nmi
, throttle
,
3919 * We inhibit the overflow from happening when
3920 * hwc->interrupts == MAX_INTERRUPTS.
3928 static void perf_swevent_unthrottle(struct perf_event
*event
)
3931 * Nothing to do, we already reset hwc->interrupts.
3935 static void perf_swevent_add(struct perf_event
*event
, u64 nr
,
3936 int nmi
, struct perf_sample_data
*data
,
3937 struct pt_regs
*regs
)
3939 struct hw_perf_event
*hwc
= &event
->hw
;
3941 atomic64_add(nr
, &event
->count
);
3946 if (!hwc
->sample_period
)
3949 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
3950 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
3952 if (atomic64_add_negative(nr
, &hwc
->period_left
))
3955 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
3958 static int perf_swevent_is_counting(struct perf_event
*event
)
3961 * The event is active, we're good!
3963 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3967 * The event is off/error, not counting.
3969 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
)
3973 * The event is inactive, if the context is active
3974 * we're part of a group that didn't make it on the 'pmu',
3977 if (event
->ctx
->is_active
)
3981 * We're inactive and the context is too, this means the
3982 * task is scheduled out, we're counting events that happen
3983 * to us, like migration events.
3988 static int perf_tp_event_match(struct perf_event
*event
,
3989 struct perf_sample_data
*data
);
3991 static int perf_exclude_event(struct perf_event
*event
,
3992 struct pt_regs
*regs
)
3995 if (event
->attr
.exclude_user
&& user_mode(regs
))
3998 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4005 static int perf_swevent_match(struct perf_event
*event
,
4006 enum perf_type_id type
,
4008 struct perf_sample_data
*data
,
4009 struct pt_regs
*regs
)
4011 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
4014 if (!perf_swevent_is_counting(event
))
4017 if (event
->attr
.type
!= type
)
4020 if (event
->attr
.config
!= event_id
)
4023 if (perf_exclude_event(event
, regs
))
4026 if (event
->attr
.type
== PERF_TYPE_TRACEPOINT
&&
4027 !perf_tp_event_match(event
, data
))
4033 static void perf_swevent_ctx_event(struct perf_event_context
*ctx
,
4034 enum perf_type_id type
,
4035 u32 event_id
, u64 nr
, int nmi
,
4036 struct perf_sample_data
*data
,
4037 struct pt_regs
*regs
)
4039 struct perf_event
*event
;
4041 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4042 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4043 perf_swevent_add(event
, nr
, nmi
, data
, regs
);
4047 int perf_swevent_get_recursion_context(void)
4049 struct perf_cpu_context
*cpuctx
= &get_cpu_var(perf_cpu_context
);
4056 else if (in_softirq())
4061 if (cpuctx
->recursion
[rctx
]) {
4062 put_cpu_var(perf_cpu_context
);
4066 cpuctx
->recursion
[rctx
]++;
4071 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4073 void perf_swevent_put_recursion_context(int rctx
)
4075 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
4077 cpuctx
->recursion
[rctx
]--;
4078 put_cpu_var(perf_cpu_context
);
4080 EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context
);
4082 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4084 struct perf_sample_data
*data
,
4085 struct pt_regs
*regs
)
4087 struct perf_cpu_context
*cpuctx
;
4088 struct perf_event_context
*ctx
;
4090 cpuctx
= &__get_cpu_var(perf_cpu_context
);
4092 perf_swevent_ctx_event(&cpuctx
->ctx
, type
, event_id
,
4093 nr
, nmi
, data
, regs
);
4095 * doesn't really matter which of the child contexts the
4096 * events ends up in.
4098 ctx
= rcu_dereference(current
->perf_event_ctxp
);
4100 perf_swevent_ctx_event(ctx
, type
, event_id
, nr
, nmi
, data
, regs
);
4104 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
4105 struct pt_regs
*regs
, u64 addr
)
4107 struct perf_sample_data data
;
4110 rctx
= perf_swevent_get_recursion_context();
4114 perf_sample_data_init(&data
, addr
);
4116 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
4118 perf_swevent_put_recursion_context(rctx
);
4121 static void perf_swevent_read(struct perf_event
*event
)
4125 static int perf_swevent_enable(struct perf_event
*event
)
4127 struct hw_perf_event
*hwc
= &event
->hw
;
4129 if (hwc
->sample_period
) {
4130 hwc
->last_period
= hwc
->sample_period
;
4131 perf_swevent_set_period(event
);
4136 static void perf_swevent_disable(struct perf_event
*event
)
4140 static const struct pmu perf_ops_generic
= {
4141 .enable
= perf_swevent_enable
,
4142 .disable
= perf_swevent_disable
,
4143 .read
= perf_swevent_read
,
4144 .unthrottle
= perf_swevent_unthrottle
,
4148 * hrtimer based swevent callback
4151 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
4153 enum hrtimer_restart ret
= HRTIMER_RESTART
;
4154 struct perf_sample_data data
;
4155 struct pt_regs
*regs
;
4156 struct perf_event
*event
;
4159 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
4160 event
->pmu
->read(event
);
4162 perf_sample_data_init(&data
, 0);
4163 data
.period
= event
->hw
.last_period
;
4164 regs
= get_irq_regs();
4166 * In case we exclude kernel IPs or are somehow not in interrupt
4167 * context, provide the next best thing, the user IP.
4169 if ((event
->attr
.exclude_kernel
|| !regs
) &&
4170 !event
->attr
.exclude_user
)
4171 regs
= task_pt_regs(current
);
4174 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
4175 if (perf_event_overflow(event
, 0, &data
, regs
))
4176 ret
= HRTIMER_NORESTART
;
4179 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
4180 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
4185 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
4187 struct hw_perf_event
*hwc
= &event
->hw
;
4189 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
4190 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
4191 if (hwc
->sample_period
) {
4194 if (hwc
->remaining
) {
4195 if (hwc
->remaining
< 0)
4198 period
= hwc
->remaining
;
4201 period
= max_t(u64
, 10000, hwc
->sample_period
);
4203 __hrtimer_start_range_ns(&hwc
->hrtimer
,
4204 ns_to_ktime(period
), 0,
4205 HRTIMER_MODE_REL
, 0);
4209 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
4211 struct hw_perf_event
*hwc
= &event
->hw
;
4213 if (hwc
->sample_period
) {
4214 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
4215 hwc
->remaining
= ktime_to_ns(remaining
);
4217 hrtimer_cancel(&hwc
->hrtimer
);
4222 * Software event: cpu wall time clock
4225 static void cpu_clock_perf_event_update(struct perf_event
*event
)
4227 int cpu
= raw_smp_processor_id();
4231 now
= cpu_clock(cpu
);
4232 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4233 atomic64_add(now
- prev
, &event
->count
);
4236 static int cpu_clock_perf_event_enable(struct perf_event
*event
)
4238 struct hw_perf_event
*hwc
= &event
->hw
;
4239 int cpu
= raw_smp_processor_id();
4241 atomic64_set(&hwc
->prev_count
, cpu_clock(cpu
));
4242 perf_swevent_start_hrtimer(event
);
4247 static void cpu_clock_perf_event_disable(struct perf_event
*event
)
4249 perf_swevent_cancel_hrtimer(event
);
4250 cpu_clock_perf_event_update(event
);
4253 static void cpu_clock_perf_event_read(struct perf_event
*event
)
4255 cpu_clock_perf_event_update(event
);
4258 static const struct pmu perf_ops_cpu_clock
= {
4259 .enable
= cpu_clock_perf_event_enable
,
4260 .disable
= cpu_clock_perf_event_disable
,
4261 .read
= cpu_clock_perf_event_read
,
4265 * Software event: task time clock
4268 static void task_clock_perf_event_update(struct perf_event
*event
, u64 now
)
4273 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4275 atomic64_add(delta
, &event
->count
);
4278 static int task_clock_perf_event_enable(struct perf_event
*event
)
4280 struct hw_perf_event
*hwc
= &event
->hw
;
4283 now
= event
->ctx
->time
;
4285 atomic64_set(&hwc
->prev_count
, now
);
4287 perf_swevent_start_hrtimer(event
);
4292 static void task_clock_perf_event_disable(struct perf_event
*event
)
4294 perf_swevent_cancel_hrtimer(event
);
4295 task_clock_perf_event_update(event
, event
->ctx
->time
);
4299 static void task_clock_perf_event_read(struct perf_event
*event
)
4304 update_context_time(event
->ctx
);
4305 time
= event
->ctx
->time
;
4307 u64 now
= perf_clock();
4308 u64 delta
= now
- event
->ctx
->timestamp
;
4309 time
= event
->ctx
->time
+ delta
;
4312 task_clock_perf_event_update(event
, time
);
4315 static const struct pmu perf_ops_task_clock
= {
4316 .enable
= task_clock_perf_event_enable
,
4317 .disable
= task_clock_perf_event_disable
,
4318 .read
= task_clock_perf_event_read
,
4321 #ifdef CONFIG_EVENT_TRACING
4323 void perf_tp_event(int event_id
, u64 addr
, u64 count
, void *record
,
4324 int entry_size
, struct pt_regs
*regs
)
4326 struct perf_sample_data data
;
4327 struct perf_raw_record raw
= {
4332 perf_sample_data_init(&data
, addr
);
4335 /* Trace events already protected against recursion */
4336 do_perf_sw_event(PERF_TYPE_TRACEPOINT
, event_id
, count
, 1,
4339 EXPORT_SYMBOL_GPL(perf_tp_event
);
4341 static int perf_tp_event_match(struct perf_event
*event
,
4342 struct perf_sample_data
*data
)
4344 void *record
= data
->raw
->data
;
4346 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
4351 static void tp_perf_event_destroy(struct perf_event
*event
)
4353 perf_trace_disable(event
->attr
.config
);
4356 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4359 * Raw tracepoint data is a severe data leak, only allow root to
4362 if ((event
->attr
.sample_type
& PERF_SAMPLE_RAW
) &&
4363 perf_paranoid_tracepoint_raw() &&
4364 !capable(CAP_SYS_ADMIN
))
4365 return ERR_PTR(-EPERM
);
4367 if (perf_trace_enable(event
->attr
.config
))
4370 event
->destroy
= tp_perf_event_destroy
;
4372 return &perf_ops_generic
;
4375 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4380 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4383 filter_str
= strndup_user(arg
, PAGE_SIZE
);
4384 if (IS_ERR(filter_str
))
4385 return PTR_ERR(filter_str
);
4387 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
4393 static void perf_event_free_filter(struct perf_event
*event
)
4395 ftrace_profile_free_filter(event
);
4400 static int perf_tp_event_match(struct perf_event
*event
,
4401 struct perf_sample_data
*data
)
4406 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4411 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4416 static void perf_event_free_filter(struct perf_event
*event
)
4420 #endif /* CONFIG_EVENT_TRACING */
4422 #ifdef CONFIG_HAVE_HW_BREAKPOINT
4423 static void bp_perf_event_destroy(struct perf_event
*event
)
4425 release_bp_slot(event
);
4428 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4432 err
= register_perf_hw_breakpoint(bp
);
4434 return ERR_PTR(err
);
4436 bp
->destroy
= bp_perf_event_destroy
;
4438 return &perf_ops_bp
;
4441 void perf_bp_event(struct perf_event
*bp
, void *data
)
4443 struct perf_sample_data sample
;
4444 struct pt_regs
*regs
= data
;
4446 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
4448 if (!perf_exclude_event(bp
, regs
))
4449 perf_swevent_add(bp
, 1, 1, &sample
, regs
);
4452 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4457 void perf_bp_event(struct perf_event
*bp
, void *regs
)
4462 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4464 static void sw_perf_event_destroy(struct perf_event
*event
)
4466 u64 event_id
= event
->attr
.config
;
4468 WARN_ON(event
->parent
);
4470 atomic_dec(&perf_swevent_enabled
[event_id
]);
4473 static const struct pmu
*sw_perf_event_init(struct perf_event
*event
)
4475 const struct pmu
*pmu
= NULL
;
4476 u64 event_id
= event
->attr
.config
;
4479 * Software events (currently) can't in general distinguish
4480 * between user, kernel and hypervisor events.
4481 * However, context switches and cpu migrations are considered
4482 * to be kernel events, and page faults are never hypervisor
4486 case PERF_COUNT_SW_CPU_CLOCK
:
4487 pmu
= &perf_ops_cpu_clock
;
4490 case PERF_COUNT_SW_TASK_CLOCK
:
4492 * If the user instantiates this as a per-cpu event,
4493 * use the cpu_clock event instead.
4495 if (event
->ctx
->task
)
4496 pmu
= &perf_ops_task_clock
;
4498 pmu
= &perf_ops_cpu_clock
;
4501 case PERF_COUNT_SW_PAGE_FAULTS
:
4502 case PERF_COUNT_SW_PAGE_FAULTS_MIN
:
4503 case PERF_COUNT_SW_PAGE_FAULTS_MAJ
:
4504 case PERF_COUNT_SW_CONTEXT_SWITCHES
:
4505 case PERF_COUNT_SW_CPU_MIGRATIONS
:
4506 case PERF_COUNT_SW_ALIGNMENT_FAULTS
:
4507 case PERF_COUNT_SW_EMULATION_FAULTS
:
4508 if (!event
->parent
) {
4509 atomic_inc(&perf_swevent_enabled
[event_id
]);
4510 event
->destroy
= sw_perf_event_destroy
;
4512 pmu
= &perf_ops_generic
;
4520 * Allocate and initialize a event structure
4522 static struct perf_event
*
4523 perf_event_alloc(struct perf_event_attr
*attr
,
4525 struct perf_event_context
*ctx
,
4526 struct perf_event
*group_leader
,
4527 struct perf_event
*parent_event
,
4528 perf_overflow_handler_t overflow_handler
,
4531 const struct pmu
*pmu
;
4532 struct perf_event
*event
;
4533 struct hw_perf_event
*hwc
;
4536 event
= kzalloc(sizeof(*event
), gfpflags
);
4538 return ERR_PTR(-ENOMEM
);
4541 * Single events are their own group leaders, with an
4542 * empty sibling list:
4545 group_leader
= event
;
4547 mutex_init(&event
->child_mutex
);
4548 INIT_LIST_HEAD(&event
->child_list
);
4550 INIT_LIST_HEAD(&event
->group_entry
);
4551 INIT_LIST_HEAD(&event
->event_entry
);
4552 INIT_LIST_HEAD(&event
->sibling_list
);
4553 init_waitqueue_head(&event
->waitq
);
4555 mutex_init(&event
->mmap_mutex
);
4558 event
->attr
= *attr
;
4559 event
->group_leader
= group_leader
;
4564 event
->parent
= parent_event
;
4566 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
4567 event
->id
= atomic64_inc_return(&perf_event_id
);
4569 event
->state
= PERF_EVENT_STATE_INACTIVE
;
4571 if (!overflow_handler
&& parent_event
)
4572 overflow_handler
= parent_event
->overflow_handler
;
4574 event
->overflow_handler
= overflow_handler
;
4577 event
->state
= PERF_EVENT_STATE_OFF
;
4582 hwc
->sample_period
= attr
->sample_period
;
4583 if (attr
->freq
&& attr
->sample_freq
)
4584 hwc
->sample_period
= 1;
4585 hwc
->last_period
= hwc
->sample_period
;
4587 atomic64_set(&hwc
->period_left
, hwc
->sample_period
);
4590 * we currently do not support PERF_FORMAT_GROUP on inherited events
4592 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
4595 switch (attr
->type
) {
4597 case PERF_TYPE_HARDWARE
:
4598 case PERF_TYPE_HW_CACHE
:
4599 pmu
= hw_perf_event_init(event
);
4602 case PERF_TYPE_SOFTWARE
:
4603 pmu
= sw_perf_event_init(event
);
4606 case PERF_TYPE_TRACEPOINT
:
4607 pmu
= tp_perf_event_init(event
);
4610 case PERF_TYPE_BREAKPOINT
:
4611 pmu
= bp_perf_event_init(event
);
4622 else if (IS_ERR(pmu
))
4627 put_pid_ns(event
->ns
);
4629 return ERR_PTR(err
);
4634 if (!event
->parent
) {
4635 atomic_inc(&nr_events
);
4636 if (event
->attr
.mmap
)
4637 atomic_inc(&nr_mmap_events
);
4638 if (event
->attr
.comm
)
4639 atomic_inc(&nr_comm_events
);
4640 if (event
->attr
.task
)
4641 atomic_inc(&nr_task_events
);
4647 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
4648 struct perf_event_attr
*attr
)
4653 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
4657 * zero the full structure, so that a short copy will be nice.
4659 memset(attr
, 0, sizeof(*attr
));
4661 ret
= get_user(size
, &uattr
->size
);
4665 if (size
> PAGE_SIZE
) /* silly large */
4668 if (!size
) /* abi compat */
4669 size
= PERF_ATTR_SIZE_VER0
;
4671 if (size
< PERF_ATTR_SIZE_VER0
)
4675 * If we're handed a bigger struct than we know of,
4676 * ensure all the unknown bits are 0 - i.e. new
4677 * user-space does not rely on any kernel feature
4678 * extensions we dont know about yet.
4680 if (size
> sizeof(*attr
)) {
4681 unsigned char __user
*addr
;
4682 unsigned char __user
*end
;
4685 addr
= (void __user
*)uattr
+ sizeof(*attr
);
4686 end
= (void __user
*)uattr
+ size
;
4688 for (; addr
< end
; addr
++) {
4689 ret
= get_user(val
, addr
);
4695 size
= sizeof(*attr
);
4698 ret
= copy_from_user(attr
, uattr
, size
);
4703 * If the type exists, the corresponding creation will verify
4706 if (attr
->type
>= PERF_TYPE_MAX
)
4709 if (attr
->__reserved_1
)
4712 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
4715 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
4722 put_user(sizeof(*attr
), &uattr
->size
);
4727 static int perf_event_set_output(struct perf_event
*event
, int output_fd
)
4729 struct perf_event
*output_event
= NULL
;
4730 struct file
*output_file
= NULL
;
4731 struct perf_event
*old_output
;
4732 int fput_needed
= 0;
4738 output_file
= fget_light(output_fd
, &fput_needed
);
4742 if (output_file
->f_op
!= &perf_fops
)
4745 output_event
= output_file
->private_data
;
4747 /* Don't chain output fds */
4748 if (output_event
->output
)
4751 /* Don't set an output fd when we already have an output channel */
4755 atomic_long_inc(&output_file
->f_count
);
4758 mutex_lock(&event
->mmap_mutex
);
4759 old_output
= event
->output
;
4760 rcu_assign_pointer(event
->output
, output_event
);
4761 mutex_unlock(&event
->mmap_mutex
);
4765 * we need to make sure no existing perf_output_*()
4766 * is still referencing this event.
4769 fput(old_output
->filp
);
4774 fput_light(output_file
, fput_needed
);
4779 * sys_perf_event_open - open a performance event, associate it to a task/cpu
4781 * @attr_uptr: event_id type attributes for monitoring/sampling
4784 * @group_fd: group leader event fd
4786 SYSCALL_DEFINE5(perf_event_open
,
4787 struct perf_event_attr __user
*, attr_uptr
,
4788 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
4790 struct perf_event
*event
, *group_leader
;
4791 struct perf_event_attr attr
;
4792 struct perf_event_context
*ctx
;
4793 struct file
*event_file
= NULL
;
4794 struct file
*group_file
= NULL
;
4795 int fput_needed
= 0;
4796 int fput_needed2
= 0;
4799 /* for future expandability... */
4800 if (flags
& ~(PERF_FLAG_FD_NO_GROUP
| PERF_FLAG_FD_OUTPUT
))
4803 err
= perf_copy_attr(attr_uptr
, &attr
);
4807 if (!attr
.exclude_kernel
) {
4808 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
4813 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
4818 * Get the target context (task or percpu):
4820 ctx
= find_get_context(pid
, cpu
);
4822 return PTR_ERR(ctx
);
4825 * Look up the group leader (we will attach this event to it):
4827 group_leader
= NULL
;
4828 if (group_fd
!= -1 && !(flags
& PERF_FLAG_FD_NO_GROUP
)) {
4830 group_file
= fget_light(group_fd
, &fput_needed
);
4832 goto err_put_context
;
4833 if (group_file
->f_op
!= &perf_fops
)
4834 goto err_put_context
;
4836 group_leader
= group_file
->private_data
;
4838 * Do not allow a recursive hierarchy (this new sibling
4839 * becoming part of another group-sibling):
4841 if (group_leader
->group_leader
!= group_leader
)
4842 goto err_put_context
;
4844 * Do not allow to attach to a group in a different
4845 * task or CPU context:
4847 if (group_leader
->ctx
!= ctx
)
4848 goto err_put_context
;
4850 * Only a group leader can be exclusive or pinned
4852 if (attr
.exclusive
|| attr
.pinned
)
4853 goto err_put_context
;
4856 event
= perf_event_alloc(&attr
, cpu
, ctx
, group_leader
,
4857 NULL
, NULL
, GFP_KERNEL
);
4858 err
= PTR_ERR(event
);
4860 goto err_put_context
;
4862 err
= anon_inode_getfd("[perf_event]", &perf_fops
, event
, O_RDWR
);
4864 goto err_free_put_context
;
4866 event_file
= fget_light(err
, &fput_needed2
);
4868 goto err_free_put_context
;
4870 if (flags
& PERF_FLAG_FD_OUTPUT
) {
4871 err
= perf_event_set_output(event
, group_fd
);
4873 goto err_fput_free_put_context
;
4876 event
->filp
= event_file
;
4877 WARN_ON_ONCE(ctx
->parent_ctx
);
4878 mutex_lock(&ctx
->mutex
);
4879 perf_install_in_context(ctx
, event
, cpu
);
4881 mutex_unlock(&ctx
->mutex
);
4883 event
->owner
= current
;
4884 get_task_struct(current
);
4885 mutex_lock(¤t
->perf_event_mutex
);
4886 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
4887 mutex_unlock(¤t
->perf_event_mutex
);
4889 err_fput_free_put_context
:
4890 fput_light(event_file
, fput_needed2
);
4892 err_free_put_context
:
4900 fput_light(group_file
, fput_needed
);
4906 * perf_event_create_kernel_counter
4908 * @attr: attributes of the counter to create
4909 * @cpu: cpu in which the counter is bound
4910 * @pid: task to profile
4913 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
4915 perf_overflow_handler_t overflow_handler
)
4917 struct perf_event
*event
;
4918 struct perf_event_context
*ctx
;
4922 * Get the target context (task or percpu):
4925 ctx
= find_get_context(pid
, cpu
);
4931 event
= perf_event_alloc(attr
, cpu
, ctx
, NULL
,
4932 NULL
, overflow_handler
, GFP_KERNEL
);
4933 if (IS_ERR(event
)) {
4934 err
= PTR_ERR(event
);
4935 goto err_put_context
;
4939 WARN_ON_ONCE(ctx
->parent_ctx
);
4940 mutex_lock(&ctx
->mutex
);
4941 perf_install_in_context(ctx
, event
, cpu
);
4943 mutex_unlock(&ctx
->mutex
);
4945 event
->owner
= current
;
4946 get_task_struct(current
);
4947 mutex_lock(¤t
->perf_event_mutex
);
4948 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
4949 mutex_unlock(¤t
->perf_event_mutex
);
4956 return ERR_PTR(err
);
4958 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
4961 * inherit a event from parent task to child task:
4963 static struct perf_event
*
4964 inherit_event(struct perf_event
*parent_event
,
4965 struct task_struct
*parent
,
4966 struct perf_event_context
*parent_ctx
,
4967 struct task_struct
*child
,
4968 struct perf_event
*group_leader
,
4969 struct perf_event_context
*child_ctx
)
4971 struct perf_event
*child_event
;
4974 * Instead of creating recursive hierarchies of events,
4975 * we link inherited events back to the original parent,
4976 * which has a filp for sure, which we use as the reference
4979 if (parent_event
->parent
)
4980 parent_event
= parent_event
->parent
;
4982 child_event
= perf_event_alloc(&parent_event
->attr
,
4983 parent_event
->cpu
, child_ctx
,
4984 group_leader
, parent_event
,
4986 if (IS_ERR(child_event
))
4991 * Make the child state follow the state of the parent event,
4992 * not its attr.disabled bit. We hold the parent's mutex,
4993 * so we won't race with perf_event_{en, dis}able_family.
4995 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
4996 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
4998 child_event
->state
= PERF_EVENT_STATE_OFF
;
5000 if (parent_event
->attr
.freq
) {
5001 u64 sample_period
= parent_event
->hw
.sample_period
;
5002 struct hw_perf_event
*hwc
= &child_event
->hw
;
5004 hwc
->sample_period
= sample_period
;
5005 hwc
->last_period
= sample_period
;
5007 atomic64_set(&hwc
->period_left
, sample_period
);
5010 child_event
->overflow_handler
= parent_event
->overflow_handler
;
5013 * Link it up in the child's context:
5015 add_event_to_ctx(child_event
, child_ctx
);
5018 * Get a reference to the parent filp - we will fput it
5019 * when the child event exits. This is safe to do because
5020 * we are in the parent and we know that the filp still
5021 * exists and has a nonzero count:
5023 atomic_long_inc(&parent_event
->filp
->f_count
);
5026 * Link this into the parent event's child list
5028 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5029 mutex_lock(&parent_event
->child_mutex
);
5030 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
5031 mutex_unlock(&parent_event
->child_mutex
);
5036 static int inherit_group(struct perf_event
*parent_event
,
5037 struct task_struct
*parent
,
5038 struct perf_event_context
*parent_ctx
,
5039 struct task_struct
*child
,
5040 struct perf_event_context
*child_ctx
)
5042 struct perf_event
*leader
;
5043 struct perf_event
*sub
;
5044 struct perf_event
*child_ctr
;
5046 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
5047 child
, NULL
, child_ctx
);
5049 return PTR_ERR(leader
);
5050 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
5051 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
5052 child
, leader
, child_ctx
);
5053 if (IS_ERR(child_ctr
))
5054 return PTR_ERR(child_ctr
);
5059 static void sync_child_event(struct perf_event
*child_event
,
5060 struct task_struct
*child
)
5062 struct perf_event
*parent_event
= child_event
->parent
;
5065 if (child_event
->attr
.inherit_stat
)
5066 perf_event_read_event(child_event
, child
);
5068 child_val
= atomic64_read(&child_event
->count
);
5071 * Add back the child's count to the parent's count:
5073 atomic64_add(child_val
, &parent_event
->count
);
5074 atomic64_add(child_event
->total_time_enabled
,
5075 &parent_event
->child_total_time_enabled
);
5076 atomic64_add(child_event
->total_time_running
,
5077 &parent_event
->child_total_time_running
);
5080 * Remove this event from the parent's list
5082 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5083 mutex_lock(&parent_event
->child_mutex
);
5084 list_del_init(&child_event
->child_list
);
5085 mutex_unlock(&parent_event
->child_mutex
);
5088 * Release the parent event, if this was the last
5091 fput(parent_event
->filp
);
5095 __perf_event_exit_task(struct perf_event
*child_event
,
5096 struct perf_event_context
*child_ctx
,
5097 struct task_struct
*child
)
5099 struct perf_event
*parent_event
;
5101 perf_event_remove_from_context(child_event
);
5103 parent_event
= child_event
->parent
;
5105 * It can happen that parent exits first, and has events
5106 * that are still around due to the child reference. These
5107 * events need to be zapped - but otherwise linger.
5110 sync_child_event(child_event
, child
);
5111 free_event(child_event
);
5116 * When a child task exits, feed back event values to parent events.
5118 void perf_event_exit_task(struct task_struct
*child
)
5120 struct perf_event
*child_event
, *tmp
;
5121 struct perf_event_context
*child_ctx
;
5122 unsigned long flags
;
5124 if (likely(!child
->perf_event_ctxp
)) {
5125 perf_event_task(child
, NULL
, 0);
5129 local_irq_save(flags
);
5131 * We can't reschedule here because interrupts are disabled,
5132 * and either child is current or it is a task that can't be
5133 * scheduled, so we are now safe from rescheduling changing
5136 child_ctx
= child
->perf_event_ctxp
;
5137 __perf_event_task_sched_out(child_ctx
);
5140 * Take the context lock here so that if find_get_context is
5141 * reading child->perf_event_ctxp, we wait until it has
5142 * incremented the context's refcount before we do put_ctx below.
5144 raw_spin_lock(&child_ctx
->lock
);
5145 child
->perf_event_ctxp
= NULL
;
5147 * If this context is a clone; unclone it so it can't get
5148 * swapped to another process while we're removing all
5149 * the events from it.
5151 unclone_ctx(child_ctx
);
5152 update_context_time(child_ctx
);
5153 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
5156 * Report the task dead after unscheduling the events so that we
5157 * won't get any samples after PERF_RECORD_EXIT. We can however still
5158 * get a few PERF_RECORD_READ events.
5160 perf_event_task(child
, child_ctx
, 0);
5163 * We can recurse on the same lock type through:
5165 * __perf_event_exit_task()
5166 * sync_child_event()
5167 * fput(parent_event->filp)
5169 * mutex_lock(&ctx->mutex)
5171 * But since its the parent context it won't be the same instance.
5173 mutex_lock_nested(&child_ctx
->mutex
, SINGLE_DEPTH_NESTING
);
5176 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
5178 __perf_event_exit_task(child_event
, child_ctx
, child
);
5180 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
5182 __perf_event_exit_task(child_event
, child_ctx
, child
);
5185 * If the last event was a group event, it will have appended all
5186 * its siblings to the list, but we obtained 'tmp' before that which
5187 * will still point to the list head terminating the iteration.
5189 if (!list_empty(&child_ctx
->pinned_groups
) ||
5190 !list_empty(&child_ctx
->flexible_groups
))
5193 mutex_unlock(&child_ctx
->mutex
);
5198 static void perf_free_event(struct perf_event
*event
,
5199 struct perf_event_context
*ctx
)
5201 struct perf_event
*parent
= event
->parent
;
5203 if (WARN_ON_ONCE(!parent
))
5206 mutex_lock(&parent
->child_mutex
);
5207 list_del_init(&event
->child_list
);
5208 mutex_unlock(&parent
->child_mutex
);
5212 list_del_event(event
, ctx
);
5217 * free an unexposed, unused context as created by inheritance by
5218 * init_task below, used by fork() in case of fail.
5220 void perf_event_free_task(struct task_struct
*task
)
5222 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
5223 struct perf_event
*event
, *tmp
;
5228 mutex_lock(&ctx
->mutex
);
5230 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5231 perf_free_event(event
, ctx
);
5233 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
5235 perf_free_event(event
, ctx
);
5237 if (!list_empty(&ctx
->pinned_groups
) ||
5238 !list_empty(&ctx
->flexible_groups
))
5241 mutex_unlock(&ctx
->mutex
);
5247 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
5248 struct perf_event_context
*parent_ctx
,
5249 struct task_struct
*child
,
5253 struct perf_event_context
*child_ctx
= child
->perf_event_ctxp
;
5255 if (!event
->attr
.inherit
) {
5262 * This is executed from the parent task context, so
5263 * inherit events that have been marked for cloning.
5264 * First allocate and initialize a context for the
5268 child_ctx
= kzalloc(sizeof(struct perf_event_context
),
5273 __perf_event_init_context(child_ctx
, child
);
5274 child
->perf_event_ctxp
= child_ctx
;
5275 get_task_struct(child
);
5278 ret
= inherit_group(event
, parent
, parent_ctx
,
5289 * Initialize the perf_event context in task_struct
5291 int perf_event_init_task(struct task_struct
*child
)
5293 struct perf_event_context
*child_ctx
, *parent_ctx
;
5294 struct perf_event_context
*cloned_ctx
;
5295 struct perf_event
*event
;
5296 struct task_struct
*parent
= current
;
5297 int inherited_all
= 1;
5300 child
->perf_event_ctxp
= NULL
;
5302 mutex_init(&child
->perf_event_mutex
);
5303 INIT_LIST_HEAD(&child
->perf_event_list
);
5305 if (likely(!parent
->perf_event_ctxp
))
5309 * If the parent's context is a clone, pin it so it won't get
5312 parent_ctx
= perf_pin_task_context(parent
);
5315 * No need to check if parent_ctx != NULL here; since we saw
5316 * it non-NULL earlier, the only reason for it to become NULL
5317 * is if we exit, and since we're currently in the middle of
5318 * a fork we can't be exiting at the same time.
5322 * Lock the parent list. No need to lock the child - not PID
5323 * hashed yet and not running, so nobody can access it.
5325 mutex_lock(&parent_ctx
->mutex
);
5328 * We dont have to disable NMIs - we are only looking at
5329 * the list, not manipulating it:
5331 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
5332 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5338 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
5339 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5345 child_ctx
= child
->perf_event_ctxp
;
5347 if (child_ctx
&& inherited_all
) {
5349 * Mark the child context as a clone of the parent
5350 * context, or of whatever the parent is a clone of.
5351 * Note that if the parent is a clone, it could get
5352 * uncloned at any point, but that doesn't matter
5353 * because the list of events and the generation
5354 * count can't have changed since we took the mutex.
5356 cloned_ctx
= rcu_dereference(parent_ctx
->parent_ctx
);
5358 child_ctx
->parent_ctx
= cloned_ctx
;
5359 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
5361 child_ctx
->parent_ctx
= parent_ctx
;
5362 child_ctx
->parent_gen
= parent_ctx
->generation
;
5364 get_ctx(child_ctx
->parent_ctx
);
5367 mutex_unlock(&parent_ctx
->mutex
);
5369 perf_unpin_context(parent_ctx
);
5374 static void __init
perf_event_init_all_cpus(void)
5377 struct perf_cpu_context
*cpuctx
;
5379 for_each_possible_cpu(cpu
) {
5380 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5381 __perf_event_init_context(&cpuctx
->ctx
, NULL
);
5385 static void __cpuinit
perf_event_init_cpu(int cpu
)
5387 struct perf_cpu_context
*cpuctx
;
5389 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5391 spin_lock(&perf_resource_lock
);
5392 cpuctx
->max_pertask
= perf_max_events
- perf_reserved_percpu
;
5393 spin_unlock(&perf_resource_lock
);
5396 #ifdef CONFIG_HOTPLUG_CPU
5397 static void __perf_event_exit_cpu(void *info
)
5399 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
5400 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5401 struct perf_event
*event
, *tmp
;
5403 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5404 __perf_event_remove_from_context(event
);
5405 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
5406 __perf_event_remove_from_context(event
);
5408 static void perf_event_exit_cpu(int cpu
)
5410 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5411 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5413 mutex_lock(&ctx
->mutex
);
5414 smp_call_function_single(cpu
, __perf_event_exit_cpu
, NULL
, 1);
5415 mutex_unlock(&ctx
->mutex
);
5418 static inline void perf_event_exit_cpu(int cpu
) { }
5421 static int __cpuinit
5422 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
5424 unsigned int cpu
= (long)hcpu
;
5428 case CPU_UP_PREPARE
:
5429 case CPU_UP_PREPARE_FROZEN
:
5430 perf_event_init_cpu(cpu
);
5433 case CPU_DOWN_PREPARE
:
5434 case CPU_DOWN_PREPARE_FROZEN
:
5435 perf_event_exit_cpu(cpu
);
5446 * This has to have a higher priority than migration_notifier in sched.c.
5448 static struct notifier_block __cpuinitdata perf_cpu_nb
= {
5449 .notifier_call
= perf_cpu_notify
,
5453 void __init
perf_event_init(void)
5455 perf_event_init_all_cpus();
5456 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_UP_PREPARE
,
5457 (void *)(long)smp_processor_id());
5458 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_ONLINE
,
5459 (void *)(long)smp_processor_id());
5460 register_cpu_notifier(&perf_cpu_nb
);
5463 static ssize_t
perf_show_reserve_percpu(struct sysdev_class
*class,
5464 struct sysdev_class_attribute
*attr
,
5467 return sprintf(buf
, "%d\n", perf_reserved_percpu
);
5471 perf_set_reserve_percpu(struct sysdev_class
*class,
5472 struct sysdev_class_attribute
*attr
,
5476 struct perf_cpu_context
*cpuctx
;
5480 err
= strict_strtoul(buf
, 10, &val
);
5483 if (val
> perf_max_events
)
5486 spin_lock(&perf_resource_lock
);
5487 perf_reserved_percpu
= val
;
5488 for_each_online_cpu(cpu
) {
5489 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5490 raw_spin_lock_irq(&cpuctx
->ctx
.lock
);
5491 mpt
= min(perf_max_events
- cpuctx
->ctx
.nr_events
,
5492 perf_max_events
- perf_reserved_percpu
);
5493 cpuctx
->max_pertask
= mpt
;
5494 raw_spin_unlock_irq(&cpuctx
->ctx
.lock
);
5496 spin_unlock(&perf_resource_lock
);
5501 static ssize_t
perf_show_overcommit(struct sysdev_class
*class,
5502 struct sysdev_class_attribute
*attr
,
5505 return sprintf(buf
, "%d\n", perf_overcommit
);
5509 perf_set_overcommit(struct sysdev_class
*class,
5510 struct sysdev_class_attribute
*attr
,
5511 const char *buf
, size_t count
)
5516 err
= strict_strtoul(buf
, 10, &val
);
5522 spin_lock(&perf_resource_lock
);
5523 perf_overcommit
= val
;
5524 spin_unlock(&perf_resource_lock
);
5529 static SYSDEV_CLASS_ATTR(
5532 perf_show_reserve_percpu
,
5533 perf_set_reserve_percpu
5536 static SYSDEV_CLASS_ATTR(
5539 perf_show_overcommit
,
5543 static struct attribute
*perfclass_attrs
[] = {
5544 &attr_reserve_percpu
.attr
,
5545 &attr_overcommit
.attr
,
5549 static struct attribute_group perfclass_attr_group
= {
5550 .attrs
= perfclass_attrs
,
5551 .name
= "perf_events",
5554 static int __init
perf_event_sysfs_init(void)
5556 return sysfs_create_group(&cpu_sysdev_class
.kset
.kobj
,
5557 &perfclass_attr_group
);
5559 device_initcall(perf_event_sysfs_init
);