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/sysfs.h>
19 #include <linux/dcache.h>
20 #include <linux/percpu.h>
21 #include <linux/ptrace.h>
22 #include <linux/vmstat.h>
23 #include <linux/vmalloc.h>
24 #include <linux/hardirq.h>
25 #include <linux/rculist.h>
26 #include <linux/uaccess.h>
27 #include <linux/syscalls.h>
28 #include <linux/anon_inodes.h>
29 #include <linux/kernel_stat.h>
30 #include <linux/perf_event.h>
31 #include <linux/ftrace_event.h>
32 #include <linux/hw_breakpoint.h>
34 #include <asm/irq_regs.h>
37 * Each CPU has a list of per CPU events:
39 static DEFINE_PER_CPU(struct perf_cpu_context
, perf_cpu_context
);
41 int perf_max_events __read_mostly
= 1;
42 static int perf_reserved_percpu __read_mostly
;
43 static int perf_overcommit __read_mostly
= 1;
45 static atomic_t nr_events __read_mostly
;
46 static atomic_t nr_mmap_events __read_mostly
;
47 static atomic_t nr_comm_events __read_mostly
;
48 static atomic_t nr_task_events __read_mostly
;
51 * perf event paranoia level:
52 * -1 - not paranoid at all
53 * 0 - disallow raw tracepoint access for unpriv
54 * 1 - disallow cpu events for unpriv
55 * 2 - disallow kernel profiling for unpriv
57 int sysctl_perf_event_paranoid __read_mostly
= 1;
59 int sysctl_perf_event_mlock __read_mostly
= 512; /* 'free' kb per user */
62 * max perf event sample rate
64 int sysctl_perf_event_sample_rate __read_mostly
= 100000;
66 static atomic64_t perf_event_id
;
69 * Lock for (sysadmin-configurable) event reservations:
71 static DEFINE_SPINLOCK(perf_resource_lock
);
74 * Architecture provided APIs - weak aliases:
76 extern __weak
const struct pmu
*hw_perf_event_init(struct perf_event
*event
)
81 void __weak
hw_perf_disable(void) { barrier(); }
82 void __weak
hw_perf_enable(void) { barrier(); }
85 hw_perf_group_sched_in(struct perf_event
*group_leader
,
86 struct perf_cpu_context
*cpuctx
,
87 struct perf_event_context
*ctx
)
92 void __weak
perf_event_print_debug(void) { }
94 static DEFINE_PER_CPU(int, perf_disable_count
);
96 void perf_disable(void)
98 if (!__get_cpu_var(perf_disable_count
)++)
102 void perf_enable(void)
104 if (!--__get_cpu_var(perf_disable_count
))
108 static void get_ctx(struct perf_event_context
*ctx
)
110 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
113 static void free_ctx(struct rcu_head
*head
)
115 struct perf_event_context
*ctx
;
117 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
121 static void put_ctx(struct perf_event_context
*ctx
)
123 if (atomic_dec_and_test(&ctx
->refcount
)) {
125 put_ctx(ctx
->parent_ctx
);
127 put_task_struct(ctx
->task
);
128 call_rcu(&ctx
->rcu_head
, free_ctx
);
132 static void unclone_ctx(struct perf_event_context
*ctx
)
134 if (ctx
->parent_ctx
) {
135 put_ctx(ctx
->parent_ctx
);
136 ctx
->parent_ctx
= NULL
;
141 * If we inherit events we want to return the parent event id
144 static u64
primary_event_id(struct perf_event
*event
)
149 id
= event
->parent
->id
;
155 * Get the perf_event_context for a task and lock it.
156 * This has to cope with with the fact that until it is locked,
157 * the context could get moved to another task.
159 static struct perf_event_context
*
160 perf_lock_task_context(struct task_struct
*task
, unsigned long *flags
)
162 struct perf_event_context
*ctx
;
166 ctx
= rcu_dereference(task
->perf_event_ctxp
);
169 * If this context is a clone of another, it might
170 * get swapped for another underneath us by
171 * perf_event_task_sched_out, though the
172 * rcu_read_lock() protects us from any context
173 * getting freed. Lock the context and check if it
174 * got swapped before we could get the lock, and retry
175 * if so. If we locked the right context, then it
176 * can't get swapped on us any more.
178 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
179 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
)) {
180 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
184 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
185 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
194 * Get the context for a task and increment its pin_count so it
195 * can't get swapped to another task. This also increments its
196 * reference count so that the context can't get freed.
198 static struct perf_event_context
*perf_pin_task_context(struct task_struct
*task
)
200 struct perf_event_context
*ctx
;
203 ctx
= perf_lock_task_context(task
, &flags
);
206 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
211 static void perf_unpin_context(struct perf_event_context
*ctx
)
215 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
217 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
221 static inline u64
perf_clock(void)
223 return cpu_clock(raw_smp_processor_id());
227 * Update the record of the current time in a context.
229 static void update_context_time(struct perf_event_context
*ctx
)
231 u64 now
= perf_clock();
233 ctx
->time
+= now
- ctx
->timestamp
;
234 ctx
->timestamp
= now
;
238 * Update the total_time_enabled and total_time_running fields for a event.
240 static void update_event_times(struct perf_event
*event
)
242 struct perf_event_context
*ctx
= event
->ctx
;
245 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
246 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
252 run_end
= event
->tstamp_stopped
;
254 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
256 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
257 run_end
= event
->tstamp_stopped
;
261 event
->total_time_running
= run_end
- event
->tstamp_running
;
264 static struct list_head
*
265 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
267 if (event
->attr
.pinned
)
268 return &ctx
->pinned_groups
;
270 return &ctx
->flexible_groups
;
274 * Add a event from the lists for its context.
275 * Must be called with ctx->mutex and ctx->lock held.
278 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
280 struct perf_event
*group_leader
= event
->group_leader
;
283 * Depending on whether it is a standalone or sibling event,
284 * add it straight to the context's event list, or to the group
285 * leader's sibling list:
287 if (group_leader
== event
) {
288 struct list_head
*list
;
290 if (is_software_event(event
))
291 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
293 list
= ctx_group_list(event
, ctx
);
294 list_add_tail(&event
->group_entry
, list
);
296 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
297 !is_software_event(event
))
298 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
300 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
301 group_leader
->nr_siblings
++;
304 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
306 if (event
->attr
.inherit_stat
)
311 * Remove a event from the lists for its context.
312 * Must be called with ctx->mutex and ctx->lock held.
315 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
317 struct perf_event
*sibling
, *tmp
;
319 if (list_empty(&event
->group_entry
))
322 if (event
->attr
.inherit_stat
)
325 list_del_init(&event
->group_entry
);
326 list_del_rcu(&event
->event_entry
);
328 if (event
->group_leader
!= event
)
329 event
->group_leader
->nr_siblings
--;
331 update_event_times(event
);
334 * If event was in error state, then keep it
335 * that way, otherwise bogus counts will be
336 * returned on read(). The only way to get out
337 * of error state is by explicit re-enabling
340 if (event
->state
> PERF_EVENT_STATE_OFF
)
341 event
->state
= PERF_EVENT_STATE_OFF
;
344 * If this was a group event with sibling events then
345 * upgrade the siblings to singleton events by adding them
346 * to the context list directly:
348 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
349 struct list_head
*list
;
351 list
= ctx_group_list(event
, ctx
);
352 list_move_tail(&sibling
->group_entry
, list
);
353 sibling
->group_leader
= sibling
;
355 /* Inherit group flags from the previous leader */
356 sibling
->group_flags
= event
->group_flags
;
361 event_sched_out(struct perf_event
*event
,
362 struct perf_cpu_context
*cpuctx
,
363 struct perf_event_context
*ctx
)
365 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
368 event
->state
= PERF_EVENT_STATE_INACTIVE
;
369 if (event
->pending_disable
) {
370 event
->pending_disable
= 0;
371 event
->state
= PERF_EVENT_STATE_OFF
;
373 event
->tstamp_stopped
= ctx
->time
;
374 event
->pmu
->disable(event
);
377 if (!is_software_event(event
))
378 cpuctx
->active_oncpu
--;
380 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
381 cpuctx
->exclusive
= 0;
385 group_sched_out(struct perf_event
*group_event
,
386 struct perf_cpu_context
*cpuctx
,
387 struct perf_event_context
*ctx
)
389 struct perf_event
*event
;
391 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
394 event_sched_out(group_event
, cpuctx
, ctx
);
397 * Schedule out siblings (if any):
399 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
400 event_sched_out(event
, cpuctx
, ctx
);
402 if (group_event
->attr
.exclusive
)
403 cpuctx
->exclusive
= 0;
407 * Cross CPU call to remove a performance event
409 * We disable the event on the hardware level first. After that we
410 * remove it from the context list.
412 static void __perf_event_remove_from_context(void *info
)
414 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
415 struct perf_event
*event
= info
;
416 struct perf_event_context
*ctx
= event
->ctx
;
419 * If this is a task context, we need to check whether it is
420 * the current task context of this cpu. If not it has been
421 * scheduled out before the smp call arrived.
423 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
426 raw_spin_lock(&ctx
->lock
);
428 * Protect the list operation against NMI by disabling the
429 * events on a global level.
433 event_sched_out(event
, cpuctx
, ctx
);
435 list_del_event(event
, ctx
);
439 * Allow more per task events with respect to the
442 cpuctx
->max_pertask
=
443 min(perf_max_events
- ctx
->nr_events
,
444 perf_max_events
- perf_reserved_percpu
);
448 raw_spin_unlock(&ctx
->lock
);
453 * Remove the event from a task's (or a CPU's) list of events.
455 * Must be called with ctx->mutex held.
457 * CPU events are removed with a smp call. For task events we only
458 * call when the task is on a CPU.
460 * If event->ctx is a cloned context, callers must make sure that
461 * every task struct that event->ctx->task could possibly point to
462 * remains valid. This is OK when called from perf_release since
463 * that only calls us on the top-level context, which can't be a clone.
464 * When called from perf_event_exit_task, it's OK because the
465 * context has been detached from its task.
467 static void perf_event_remove_from_context(struct perf_event
*event
)
469 struct perf_event_context
*ctx
= event
->ctx
;
470 struct task_struct
*task
= ctx
->task
;
474 * Per cpu events are removed via an smp call and
475 * the removal is always successful.
477 smp_call_function_single(event
->cpu
,
478 __perf_event_remove_from_context
,
484 task_oncpu_function_call(task
, __perf_event_remove_from_context
,
487 raw_spin_lock_irq(&ctx
->lock
);
489 * If the context is active we need to retry the smp call.
491 if (ctx
->nr_active
&& !list_empty(&event
->group_entry
)) {
492 raw_spin_unlock_irq(&ctx
->lock
);
497 * The lock prevents that this context is scheduled in so we
498 * can remove the event safely, if the call above did not
501 if (!list_empty(&event
->group_entry
))
502 list_del_event(event
, ctx
);
503 raw_spin_unlock_irq(&ctx
->lock
);
507 * Update total_time_enabled and total_time_running for all events in a group.
509 static void update_group_times(struct perf_event
*leader
)
511 struct perf_event
*event
;
513 update_event_times(leader
);
514 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
515 update_event_times(event
);
519 * Cross CPU call to disable a performance event
521 static void __perf_event_disable(void *info
)
523 struct perf_event
*event
= info
;
524 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
525 struct perf_event_context
*ctx
= event
->ctx
;
528 * If this is a per-task event, need to check whether this
529 * event's task is the current task on this cpu.
531 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
534 raw_spin_lock(&ctx
->lock
);
537 * If the event is on, turn it off.
538 * If it is in error state, leave it in error state.
540 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
541 update_context_time(ctx
);
542 update_group_times(event
);
543 if (event
== event
->group_leader
)
544 group_sched_out(event
, cpuctx
, ctx
);
546 event_sched_out(event
, cpuctx
, ctx
);
547 event
->state
= PERF_EVENT_STATE_OFF
;
550 raw_spin_unlock(&ctx
->lock
);
556 * If event->ctx is a cloned context, callers must make sure that
557 * every task struct that event->ctx->task could possibly point to
558 * remains valid. This condition is satisifed when called through
559 * perf_event_for_each_child or perf_event_for_each because they
560 * hold the top-level event's child_mutex, so any descendant that
561 * goes to exit will block in sync_child_event.
562 * When called from perf_pending_event it's OK because event->ctx
563 * is the current context on this CPU and preemption is disabled,
564 * hence we can't get into perf_event_task_sched_out for this context.
566 void perf_event_disable(struct perf_event
*event
)
568 struct perf_event_context
*ctx
= event
->ctx
;
569 struct task_struct
*task
= ctx
->task
;
573 * Disable the event on the cpu that it's on
575 smp_call_function_single(event
->cpu
, __perf_event_disable
,
581 task_oncpu_function_call(task
, __perf_event_disable
, event
);
583 raw_spin_lock_irq(&ctx
->lock
);
585 * If the event is still active, we need to retry the cross-call.
587 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
588 raw_spin_unlock_irq(&ctx
->lock
);
593 * Since we have the lock this context can't be scheduled
594 * in, so we can change the state safely.
596 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
597 update_group_times(event
);
598 event
->state
= PERF_EVENT_STATE_OFF
;
601 raw_spin_unlock_irq(&ctx
->lock
);
605 event_sched_in(struct perf_event
*event
,
606 struct perf_cpu_context
*cpuctx
,
607 struct perf_event_context
*ctx
)
609 if (event
->state
<= PERF_EVENT_STATE_OFF
)
612 event
->state
= PERF_EVENT_STATE_ACTIVE
;
613 event
->oncpu
= smp_processor_id();
615 * The new state must be visible before we turn it on in the hardware:
619 if (event
->pmu
->enable(event
)) {
620 event
->state
= PERF_EVENT_STATE_INACTIVE
;
625 event
->tstamp_running
+= ctx
->time
- event
->tstamp_stopped
;
627 if (!is_software_event(event
))
628 cpuctx
->active_oncpu
++;
631 if (event
->attr
.exclusive
)
632 cpuctx
->exclusive
= 1;
638 group_sched_in(struct perf_event
*group_event
,
639 struct perf_cpu_context
*cpuctx
,
640 struct perf_event_context
*ctx
)
642 struct perf_event
*event
, *partial_group
;
645 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
648 ret
= hw_perf_group_sched_in(group_event
, cpuctx
, ctx
);
650 return ret
< 0 ? ret
: 0;
652 if (event_sched_in(group_event
, cpuctx
, ctx
))
656 * Schedule in siblings as one group (if any):
658 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
659 if (event_sched_in(event
, cpuctx
, ctx
)) {
660 partial_group
= event
;
669 * Groups can be scheduled in as one unit only, so undo any
670 * partial group before returning:
672 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
673 if (event
== partial_group
)
675 event_sched_out(event
, cpuctx
, ctx
);
677 event_sched_out(group_event
, cpuctx
, ctx
);
683 * Work out whether we can put this event group on the CPU now.
685 static int group_can_go_on(struct perf_event
*event
,
686 struct perf_cpu_context
*cpuctx
,
690 * Groups consisting entirely of software events can always go on.
692 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
695 * If an exclusive group is already on, no other hardware
698 if (cpuctx
->exclusive
)
701 * If this group is exclusive and there are already
702 * events on the CPU, it can't go on.
704 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
707 * Otherwise, try to add it if all previous groups were able
713 static void add_event_to_ctx(struct perf_event
*event
,
714 struct perf_event_context
*ctx
)
716 list_add_event(event
, ctx
);
717 event
->tstamp_enabled
= ctx
->time
;
718 event
->tstamp_running
= ctx
->time
;
719 event
->tstamp_stopped
= ctx
->time
;
723 * Cross CPU call to install and enable a performance event
725 * Must be called with ctx->mutex held
727 static void __perf_install_in_context(void *info
)
729 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
730 struct perf_event
*event
= info
;
731 struct perf_event_context
*ctx
= event
->ctx
;
732 struct perf_event
*leader
= event
->group_leader
;
736 * If this is a task context, we need to check whether it is
737 * the current task context of this cpu. If not it has been
738 * scheduled out before the smp call arrived.
739 * Or possibly this is the right context but it isn't
740 * on this cpu because it had no events.
742 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
743 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
745 cpuctx
->task_ctx
= ctx
;
748 raw_spin_lock(&ctx
->lock
);
750 update_context_time(ctx
);
753 * Protect the list operation against NMI by disabling the
754 * events on a global level. NOP for non NMI based events.
758 add_event_to_ctx(event
, ctx
);
760 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
764 * Don't put the event on if it is disabled or if
765 * it is in a group and the group isn't on.
767 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
768 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
772 * An exclusive event can't go on if there are already active
773 * hardware events, and no hardware event can go on if there
774 * is already an exclusive event on.
776 if (!group_can_go_on(event
, cpuctx
, 1))
779 err
= event_sched_in(event
, cpuctx
, ctx
);
783 * This event couldn't go on. If it is in a group
784 * then we have to pull the whole group off.
785 * If the event group is pinned then put it in error state.
788 group_sched_out(leader
, cpuctx
, ctx
);
789 if (leader
->attr
.pinned
) {
790 update_group_times(leader
);
791 leader
->state
= PERF_EVENT_STATE_ERROR
;
795 if (!err
&& !ctx
->task
&& cpuctx
->max_pertask
)
796 cpuctx
->max_pertask
--;
801 raw_spin_unlock(&ctx
->lock
);
805 * Attach a performance event to a context
807 * First we add the event to the list with the hardware enable bit
808 * in event->hw_config cleared.
810 * If the event is attached to a task which is on a CPU we use a smp
811 * call to enable it in the task context. The task might have been
812 * scheduled away, but we check this in the smp call again.
814 * Must be called with ctx->mutex held.
817 perf_install_in_context(struct perf_event_context
*ctx
,
818 struct perf_event
*event
,
821 struct task_struct
*task
= ctx
->task
;
825 * Per cpu events are installed via an smp call and
826 * the install is always successful.
828 smp_call_function_single(cpu
, __perf_install_in_context
,
834 task_oncpu_function_call(task
, __perf_install_in_context
,
837 raw_spin_lock_irq(&ctx
->lock
);
839 * we need to retry the smp call.
841 if (ctx
->is_active
&& list_empty(&event
->group_entry
)) {
842 raw_spin_unlock_irq(&ctx
->lock
);
847 * The lock prevents that this context is scheduled in so we
848 * can add the event safely, if it the call above did not
851 if (list_empty(&event
->group_entry
))
852 add_event_to_ctx(event
, ctx
);
853 raw_spin_unlock_irq(&ctx
->lock
);
857 * Put a event into inactive state and update time fields.
858 * Enabling the leader of a group effectively enables all
859 * the group members that aren't explicitly disabled, so we
860 * have to update their ->tstamp_enabled also.
861 * Note: this works for group members as well as group leaders
862 * since the non-leader members' sibling_lists will be empty.
864 static void __perf_event_mark_enabled(struct perf_event
*event
,
865 struct perf_event_context
*ctx
)
867 struct perf_event
*sub
;
869 event
->state
= PERF_EVENT_STATE_INACTIVE
;
870 event
->tstamp_enabled
= ctx
->time
- event
->total_time_enabled
;
871 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
)
872 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
873 sub
->tstamp_enabled
=
874 ctx
->time
- sub
->total_time_enabled
;
878 * Cross CPU call to enable a performance event
880 static void __perf_event_enable(void *info
)
882 struct perf_event
*event
= info
;
883 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
884 struct perf_event_context
*ctx
= event
->ctx
;
885 struct perf_event
*leader
= event
->group_leader
;
889 * If this is a per-task event, need to check whether this
890 * event's task is the current task on this cpu.
892 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
893 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
895 cpuctx
->task_ctx
= ctx
;
898 raw_spin_lock(&ctx
->lock
);
900 update_context_time(ctx
);
902 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
904 __perf_event_mark_enabled(event
, ctx
);
906 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
910 * If the event is in a group and isn't the group leader,
911 * then don't put it on unless the group is on.
913 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
916 if (!group_can_go_on(event
, cpuctx
, 1)) {
921 err
= group_sched_in(event
, cpuctx
, ctx
);
923 err
= event_sched_in(event
, cpuctx
, ctx
);
929 * If this event can't go on and it's part of a
930 * group, then the whole group has to come off.
933 group_sched_out(leader
, cpuctx
, ctx
);
934 if (leader
->attr
.pinned
) {
935 update_group_times(leader
);
936 leader
->state
= PERF_EVENT_STATE_ERROR
;
941 raw_spin_unlock(&ctx
->lock
);
947 * If event->ctx is a cloned context, callers must make sure that
948 * every task struct that event->ctx->task could possibly point to
949 * remains valid. This condition is satisfied when called through
950 * perf_event_for_each_child or perf_event_for_each as described
951 * for perf_event_disable.
953 void perf_event_enable(struct perf_event
*event
)
955 struct perf_event_context
*ctx
= event
->ctx
;
956 struct task_struct
*task
= ctx
->task
;
960 * Enable the event on the cpu that it's on
962 smp_call_function_single(event
->cpu
, __perf_event_enable
,
967 raw_spin_lock_irq(&ctx
->lock
);
968 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
972 * If the event is in error state, clear that first.
973 * That way, if we see the event in error state below, we
974 * know that it has gone back into error state, as distinct
975 * from the task having been scheduled away before the
976 * cross-call arrived.
978 if (event
->state
== PERF_EVENT_STATE_ERROR
)
979 event
->state
= PERF_EVENT_STATE_OFF
;
982 raw_spin_unlock_irq(&ctx
->lock
);
983 task_oncpu_function_call(task
, __perf_event_enable
, event
);
985 raw_spin_lock_irq(&ctx
->lock
);
988 * If the context is active and the event is still off,
989 * we need to retry the cross-call.
991 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
)
995 * Since we have the lock this context can't be scheduled
996 * in, so we can change the state safely.
998 if (event
->state
== PERF_EVENT_STATE_OFF
)
999 __perf_event_mark_enabled(event
, ctx
);
1002 raw_spin_unlock_irq(&ctx
->lock
);
1005 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1008 * not supported on inherited events
1010 if (event
->attr
.inherit
)
1013 atomic_add(refresh
, &event
->event_limit
);
1014 perf_event_enable(event
);
1020 EVENT_FLEXIBLE
= 0x1,
1022 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
1025 static void ctx_sched_out(struct perf_event_context
*ctx
,
1026 struct perf_cpu_context
*cpuctx
,
1027 enum event_type_t event_type
)
1029 struct perf_event
*event
;
1031 raw_spin_lock(&ctx
->lock
);
1033 if (likely(!ctx
->nr_events
))
1035 update_context_time(ctx
);
1038 if (!ctx
->nr_active
)
1041 if (event_type
& EVENT_PINNED
)
1042 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1043 group_sched_out(event
, cpuctx
, ctx
);
1045 if (event_type
& EVENT_FLEXIBLE
)
1046 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1047 group_sched_out(event
, cpuctx
, ctx
);
1052 raw_spin_unlock(&ctx
->lock
);
1056 * Test whether two contexts are equivalent, i.e. whether they
1057 * have both been cloned from the same version of the same context
1058 * and they both have the same number of enabled events.
1059 * If the number of enabled events is the same, then the set
1060 * of enabled events should be the same, because these are both
1061 * inherited contexts, therefore we can't access individual events
1062 * in them directly with an fd; we can only enable/disable all
1063 * events via prctl, or enable/disable all events in a family
1064 * via ioctl, which will have the same effect on both contexts.
1066 static int context_equiv(struct perf_event_context
*ctx1
,
1067 struct perf_event_context
*ctx2
)
1069 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1070 && ctx1
->parent_gen
== ctx2
->parent_gen
1071 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1074 static void __perf_event_sync_stat(struct perf_event
*event
,
1075 struct perf_event
*next_event
)
1079 if (!event
->attr
.inherit_stat
)
1083 * Update the event value, we cannot use perf_event_read()
1084 * because we're in the middle of a context switch and have IRQs
1085 * disabled, which upsets smp_call_function_single(), however
1086 * we know the event must be on the current CPU, therefore we
1087 * don't need to use it.
1089 switch (event
->state
) {
1090 case PERF_EVENT_STATE_ACTIVE
:
1091 event
->pmu
->read(event
);
1094 case PERF_EVENT_STATE_INACTIVE
:
1095 update_event_times(event
);
1103 * In order to keep per-task stats reliable we need to flip the event
1104 * values when we flip the contexts.
1106 value
= atomic64_read(&next_event
->count
);
1107 value
= atomic64_xchg(&event
->count
, value
);
1108 atomic64_set(&next_event
->count
, value
);
1110 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1111 swap(event
->total_time_running
, next_event
->total_time_running
);
1114 * Since we swizzled the values, update the user visible data too.
1116 perf_event_update_userpage(event
);
1117 perf_event_update_userpage(next_event
);
1120 #define list_next_entry(pos, member) \
1121 list_entry(pos->member.next, typeof(*pos), member)
1123 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1124 struct perf_event_context
*next_ctx
)
1126 struct perf_event
*event
, *next_event
;
1131 update_context_time(ctx
);
1133 event
= list_first_entry(&ctx
->event_list
,
1134 struct perf_event
, event_entry
);
1136 next_event
= list_first_entry(&next_ctx
->event_list
,
1137 struct perf_event
, event_entry
);
1139 while (&event
->event_entry
!= &ctx
->event_list
&&
1140 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1142 __perf_event_sync_stat(event
, next_event
);
1144 event
= list_next_entry(event
, event_entry
);
1145 next_event
= list_next_entry(next_event
, event_entry
);
1150 * Called from scheduler to remove the events of the current task,
1151 * with interrupts disabled.
1153 * We stop each event and update the event value in event->count.
1155 * This does not protect us against NMI, but disable()
1156 * sets the disabled bit in the control field of event _before_
1157 * accessing the event control register. If a NMI hits, then it will
1158 * not restart the event.
1160 void perf_event_task_sched_out(struct task_struct
*task
,
1161 struct task_struct
*next
)
1163 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1164 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1165 struct perf_event_context
*next_ctx
;
1166 struct perf_event_context
*parent
;
1169 perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES
, 1, 1, NULL
, 0);
1171 if (likely(!ctx
|| !cpuctx
->task_ctx
))
1175 parent
= rcu_dereference(ctx
->parent_ctx
);
1176 next_ctx
= next
->perf_event_ctxp
;
1177 if (parent
&& next_ctx
&&
1178 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1180 * Looks like the two contexts are clones, so we might be
1181 * able to optimize the context switch. We lock both
1182 * contexts and check that they are clones under the
1183 * lock (including re-checking that neither has been
1184 * uncloned in the meantime). It doesn't matter which
1185 * order we take the locks because no other cpu could
1186 * be trying to lock both of these tasks.
1188 raw_spin_lock(&ctx
->lock
);
1189 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1190 if (context_equiv(ctx
, next_ctx
)) {
1192 * XXX do we need a memory barrier of sorts
1193 * wrt to rcu_dereference() of perf_event_ctxp
1195 task
->perf_event_ctxp
= next_ctx
;
1196 next
->perf_event_ctxp
= ctx
;
1198 next_ctx
->task
= task
;
1201 perf_event_sync_stat(ctx
, next_ctx
);
1203 raw_spin_unlock(&next_ctx
->lock
);
1204 raw_spin_unlock(&ctx
->lock
);
1209 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1210 cpuctx
->task_ctx
= NULL
;
1214 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1215 enum event_type_t event_type
)
1217 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1219 if (!cpuctx
->task_ctx
)
1222 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1225 ctx_sched_out(ctx
, cpuctx
, event_type
);
1226 cpuctx
->task_ctx
= NULL
;
1230 * Called with IRQs disabled
1232 static void __perf_event_task_sched_out(struct perf_event_context
*ctx
)
1234 task_ctx_sched_out(ctx
, EVENT_ALL
);
1238 * Called with IRQs disabled
1240 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1241 enum event_type_t event_type
)
1243 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1247 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1248 struct perf_cpu_context
*cpuctx
)
1250 struct perf_event
*event
;
1252 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1253 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1255 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1258 if (group_can_go_on(event
, cpuctx
, 1))
1259 group_sched_in(event
, cpuctx
, ctx
);
1262 * If this pinned group hasn't been scheduled,
1263 * put it in error state.
1265 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1266 update_group_times(event
);
1267 event
->state
= PERF_EVENT_STATE_ERROR
;
1273 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
1274 struct perf_cpu_context
*cpuctx
)
1276 struct perf_event
*event
;
1279 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1280 /* Ignore events in OFF or ERROR state */
1281 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1284 * Listen to the 'cpu' scheduling filter constraint
1287 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1290 if (group_can_go_on(event
, cpuctx
, can_add_hw
))
1291 if (group_sched_in(event
, cpuctx
, ctx
))
1297 ctx_sched_in(struct perf_event_context
*ctx
,
1298 struct perf_cpu_context
*cpuctx
,
1299 enum event_type_t event_type
)
1301 raw_spin_lock(&ctx
->lock
);
1303 if (likely(!ctx
->nr_events
))
1306 ctx
->timestamp
= perf_clock();
1311 * First go through the list and put on any pinned groups
1312 * in order to give them the best chance of going on.
1314 if (event_type
& EVENT_PINNED
)
1315 ctx_pinned_sched_in(ctx
, cpuctx
);
1317 /* Then walk through the lower prio flexible groups */
1318 if (event_type
& EVENT_FLEXIBLE
)
1319 ctx_flexible_sched_in(ctx
, cpuctx
);
1323 raw_spin_unlock(&ctx
->lock
);
1326 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
1327 enum event_type_t event_type
)
1329 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
1331 ctx_sched_in(ctx
, cpuctx
, event_type
);
1334 static void task_ctx_sched_in(struct task_struct
*task
,
1335 enum event_type_t event_type
)
1337 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1338 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1342 if (cpuctx
->task_ctx
== ctx
)
1344 ctx_sched_in(ctx
, cpuctx
, event_type
);
1345 cpuctx
->task_ctx
= ctx
;
1348 * Called from scheduler to add the events of the current task
1349 * with interrupts disabled.
1351 * We restore the event value and then enable it.
1353 * This does not protect us against NMI, but enable()
1354 * sets the enabled bit in the control field of event _before_
1355 * accessing the event control register. If a NMI hits, then it will
1356 * keep the event running.
1358 void perf_event_task_sched_in(struct task_struct
*task
)
1360 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1361 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1366 if (cpuctx
->task_ctx
== ctx
)
1370 * We want to keep the following priority order:
1371 * cpu pinned (that don't need to move), task pinned,
1372 * cpu flexible, task flexible.
1374 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1376 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
);
1377 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1378 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
);
1380 cpuctx
->task_ctx
= ctx
;
1383 #define MAX_INTERRUPTS (~0ULL)
1385 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1387 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1389 u64 frequency
= event
->attr
.sample_freq
;
1390 u64 sec
= NSEC_PER_SEC
;
1391 u64 divisor
, dividend
;
1393 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
1395 count_fls
= fls64(count
);
1396 nsec_fls
= fls64(nsec
);
1397 frequency_fls
= fls64(frequency
);
1401 * We got @count in @nsec, with a target of sample_freq HZ
1402 * the target period becomes:
1405 * period = -------------------
1406 * @nsec * sample_freq
1411 * Reduce accuracy by one bit such that @a and @b converge
1412 * to a similar magnitude.
1414 #define REDUCE_FLS(a, b) \
1416 if (a##_fls > b##_fls) { \
1426 * Reduce accuracy until either term fits in a u64, then proceed with
1427 * the other, so that finally we can do a u64/u64 division.
1429 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
1430 REDUCE_FLS(nsec
, frequency
);
1431 REDUCE_FLS(sec
, count
);
1434 if (count_fls
+ sec_fls
> 64) {
1435 divisor
= nsec
* frequency
;
1437 while (count_fls
+ sec_fls
> 64) {
1438 REDUCE_FLS(count
, sec
);
1442 dividend
= count
* sec
;
1444 dividend
= count
* sec
;
1446 while (nsec_fls
+ frequency_fls
> 64) {
1447 REDUCE_FLS(nsec
, frequency
);
1451 divisor
= nsec
* frequency
;
1454 return div64_u64(dividend
, divisor
);
1457 static void perf_event_stop(struct perf_event
*event
)
1459 if (!event
->pmu
->stop
)
1460 return event
->pmu
->disable(event
);
1462 return event
->pmu
->stop(event
);
1465 static int perf_event_start(struct perf_event
*event
)
1467 if (!event
->pmu
->start
)
1468 return event
->pmu
->enable(event
);
1470 return event
->pmu
->start(event
);
1473 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1475 struct hw_perf_event
*hwc
= &event
->hw
;
1476 u64 period
, sample_period
;
1479 period
= perf_calculate_period(event
, nsec
, count
);
1481 delta
= (s64
)(period
- hwc
->sample_period
);
1482 delta
= (delta
+ 7) / 8; /* low pass filter */
1484 sample_period
= hwc
->sample_period
+ delta
;
1489 hwc
->sample_period
= sample_period
;
1491 if (atomic64_read(&hwc
->period_left
) > 8*sample_period
) {
1493 perf_event_stop(event
);
1494 atomic64_set(&hwc
->period_left
, 0);
1495 perf_event_start(event
);
1500 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
)
1502 struct perf_event
*event
;
1503 struct hw_perf_event
*hwc
;
1504 u64 interrupts
, now
;
1507 raw_spin_lock(&ctx
->lock
);
1508 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
1509 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1512 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1517 interrupts
= hwc
->interrupts
;
1518 hwc
->interrupts
= 0;
1521 * unthrottle events on the tick
1523 if (interrupts
== MAX_INTERRUPTS
) {
1524 perf_log_throttle(event
, 1);
1526 event
->pmu
->unthrottle(event
);
1530 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
1534 event
->pmu
->read(event
);
1535 now
= atomic64_read(&event
->count
);
1536 delta
= now
- hwc
->freq_count_stamp
;
1537 hwc
->freq_count_stamp
= now
;
1540 perf_adjust_period(event
, TICK_NSEC
, delta
);
1543 raw_spin_unlock(&ctx
->lock
);
1547 * Round-robin a context's events:
1549 static void rotate_ctx(struct perf_event_context
*ctx
)
1551 raw_spin_lock(&ctx
->lock
);
1553 /* Rotate the first entry last of non-pinned groups */
1554 list_rotate_left(&ctx
->flexible_groups
);
1556 raw_spin_unlock(&ctx
->lock
);
1559 void perf_event_task_tick(struct task_struct
*curr
)
1561 struct perf_cpu_context
*cpuctx
;
1562 struct perf_event_context
*ctx
;
1565 if (!atomic_read(&nr_events
))
1568 cpuctx
= &__get_cpu_var(perf_cpu_context
);
1569 if (cpuctx
->ctx
.nr_events
&&
1570 cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
1573 ctx
= curr
->perf_event_ctxp
;
1574 if (ctx
&& ctx
->nr_events
&& ctx
->nr_events
!= ctx
->nr_active
)
1577 perf_ctx_adjust_freq(&cpuctx
->ctx
);
1579 perf_ctx_adjust_freq(ctx
);
1585 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1587 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
1589 rotate_ctx(&cpuctx
->ctx
);
1593 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1595 task_ctx_sched_in(curr
, EVENT_FLEXIBLE
);
1599 static int event_enable_on_exec(struct perf_event
*event
,
1600 struct perf_event_context
*ctx
)
1602 if (!event
->attr
.enable_on_exec
)
1605 event
->attr
.enable_on_exec
= 0;
1606 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1609 __perf_event_mark_enabled(event
, ctx
);
1615 * Enable all of a task's events that have been marked enable-on-exec.
1616 * This expects task == current.
1618 static void perf_event_enable_on_exec(struct task_struct
*task
)
1620 struct perf_event_context
*ctx
;
1621 struct perf_event
*event
;
1622 unsigned long flags
;
1626 local_irq_save(flags
);
1627 ctx
= task
->perf_event_ctxp
;
1628 if (!ctx
|| !ctx
->nr_events
)
1631 __perf_event_task_sched_out(ctx
);
1633 raw_spin_lock(&ctx
->lock
);
1635 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1636 ret
= event_enable_on_exec(event
, ctx
);
1641 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1642 ret
= event_enable_on_exec(event
, ctx
);
1648 * Unclone this context if we enabled any event.
1653 raw_spin_unlock(&ctx
->lock
);
1655 perf_event_task_sched_in(task
);
1657 local_irq_restore(flags
);
1661 * Cross CPU call to read the hardware event
1663 static void __perf_event_read(void *info
)
1665 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1666 struct perf_event
*event
= info
;
1667 struct perf_event_context
*ctx
= event
->ctx
;
1670 * If this is a task context, we need to check whether it is
1671 * the current task context of this cpu. If not it has been
1672 * scheduled out before the smp call arrived. In that case
1673 * event->count would have been updated to a recent sample
1674 * when the event was scheduled out.
1676 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1679 raw_spin_lock(&ctx
->lock
);
1680 update_context_time(ctx
);
1681 update_event_times(event
);
1682 raw_spin_unlock(&ctx
->lock
);
1684 event
->pmu
->read(event
);
1687 static u64
perf_event_read(struct perf_event
*event
)
1690 * If event is enabled and currently active on a CPU, update the
1691 * value in the event structure:
1693 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1694 smp_call_function_single(event
->oncpu
,
1695 __perf_event_read
, event
, 1);
1696 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1697 struct perf_event_context
*ctx
= event
->ctx
;
1698 unsigned long flags
;
1700 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1701 update_context_time(ctx
);
1702 update_event_times(event
);
1703 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1706 return atomic64_read(&event
->count
);
1710 * Initialize the perf_event context in a task_struct:
1713 __perf_event_init_context(struct perf_event_context
*ctx
,
1714 struct task_struct
*task
)
1716 raw_spin_lock_init(&ctx
->lock
);
1717 mutex_init(&ctx
->mutex
);
1718 INIT_LIST_HEAD(&ctx
->pinned_groups
);
1719 INIT_LIST_HEAD(&ctx
->flexible_groups
);
1720 INIT_LIST_HEAD(&ctx
->event_list
);
1721 atomic_set(&ctx
->refcount
, 1);
1725 static struct perf_event_context
*find_get_context(pid_t pid
, int cpu
)
1727 struct perf_event_context
*ctx
;
1728 struct perf_cpu_context
*cpuctx
;
1729 struct task_struct
*task
;
1730 unsigned long flags
;
1733 if (pid
== -1 && cpu
!= -1) {
1734 /* Must be root to operate on a CPU event: */
1735 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
1736 return ERR_PTR(-EACCES
);
1738 if (cpu
< 0 || cpu
>= nr_cpumask_bits
)
1739 return ERR_PTR(-EINVAL
);
1742 * We could be clever and allow to attach a event to an
1743 * offline CPU and activate it when the CPU comes up, but
1746 if (!cpu_online(cpu
))
1747 return ERR_PTR(-ENODEV
);
1749 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1760 task
= find_task_by_vpid(pid
);
1762 get_task_struct(task
);
1766 return ERR_PTR(-ESRCH
);
1769 * Can't attach events to a dying task.
1772 if (task
->flags
& PF_EXITING
)
1775 /* Reuse ptrace permission checks for now. */
1777 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
1781 ctx
= perf_lock_task_context(task
, &flags
);
1784 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1788 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
1792 __perf_event_init_context(ctx
, task
);
1794 if (cmpxchg(&task
->perf_event_ctxp
, NULL
, ctx
)) {
1796 * We raced with some other task; use
1797 * the context they set.
1802 get_task_struct(task
);
1805 put_task_struct(task
);
1809 put_task_struct(task
);
1810 return ERR_PTR(err
);
1813 static void perf_event_free_filter(struct perf_event
*event
);
1815 static void free_event_rcu(struct rcu_head
*head
)
1817 struct perf_event
*event
;
1819 event
= container_of(head
, struct perf_event
, rcu_head
);
1821 put_pid_ns(event
->ns
);
1822 perf_event_free_filter(event
);
1826 static void perf_pending_sync(struct perf_event
*event
);
1828 static void free_event(struct perf_event
*event
)
1830 perf_pending_sync(event
);
1832 if (!event
->parent
) {
1833 atomic_dec(&nr_events
);
1834 if (event
->attr
.mmap
)
1835 atomic_dec(&nr_mmap_events
);
1836 if (event
->attr
.comm
)
1837 atomic_dec(&nr_comm_events
);
1838 if (event
->attr
.task
)
1839 atomic_dec(&nr_task_events
);
1842 if (event
->output
) {
1843 fput(event
->output
->filp
);
1844 event
->output
= NULL
;
1848 event
->destroy(event
);
1850 put_ctx(event
->ctx
);
1851 call_rcu(&event
->rcu_head
, free_event_rcu
);
1854 int perf_event_release_kernel(struct perf_event
*event
)
1856 struct perf_event_context
*ctx
= event
->ctx
;
1858 WARN_ON_ONCE(ctx
->parent_ctx
);
1859 mutex_lock(&ctx
->mutex
);
1860 perf_event_remove_from_context(event
);
1861 mutex_unlock(&ctx
->mutex
);
1863 mutex_lock(&event
->owner
->perf_event_mutex
);
1864 list_del_init(&event
->owner_entry
);
1865 mutex_unlock(&event
->owner
->perf_event_mutex
);
1866 put_task_struct(event
->owner
);
1872 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
1875 * Called when the last reference to the file is gone.
1877 static int perf_release(struct inode
*inode
, struct file
*file
)
1879 struct perf_event
*event
= file
->private_data
;
1881 file
->private_data
= NULL
;
1883 return perf_event_release_kernel(event
);
1886 static int perf_event_read_size(struct perf_event
*event
)
1888 int entry
= sizeof(u64
); /* value */
1892 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1893 size
+= sizeof(u64
);
1895 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1896 size
+= sizeof(u64
);
1898 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1899 entry
+= sizeof(u64
);
1901 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1902 nr
+= event
->group_leader
->nr_siblings
;
1903 size
+= sizeof(u64
);
1911 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
1913 struct perf_event
*child
;
1919 mutex_lock(&event
->child_mutex
);
1920 total
+= perf_event_read(event
);
1921 *enabled
+= event
->total_time_enabled
+
1922 atomic64_read(&event
->child_total_time_enabled
);
1923 *running
+= event
->total_time_running
+
1924 atomic64_read(&event
->child_total_time_running
);
1926 list_for_each_entry(child
, &event
->child_list
, child_list
) {
1927 total
+= perf_event_read(child
);
1928 *enabled
+= child
->total_time_enabled
;
1929 *running
+= child
->total_time_running
;
1931 mutex_unlock(&event
->child_mutex
);
1935 EXPORT_SYMBOL_GPL(perf_event_read_value
);
1937 static int perf_event_read_group(struct perf_event
*event
,
1938 u64 read_format
, char __user
*buf
)
1940 struct perf_event
*leader
= event
->group_leader
, *sub
;
1941 int n
= 0, size
= 0, ret
= -EFAULT
;
1942 struct perf_event_context
*ctx
= leader
->ctx
;
1944 u64 count
, enabled
, running
;
1946 mutex_lock(&ctx
->mutex
);
1947 count
= perf_event_read_value(leader
, &enabled
, &running
);
1949 values
[n
++] = 1 + leader
->nr_siblings
;
1950 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1951 values
[n
++] = enabled
;
1952 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1953 values
[n
++] = running
;
1954 values
[n
++] = count
;
1955 if (read_format
& PERF_FORMAT_ID
)
1956 values
[n
++] = primary_event_id(leader
);
1958 size
= n
* sizeof(u64
);
1960 if (copy_to_user(buf
, values
, size
))
1965 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
1968 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
1969 if (read_format
& PERF_FORMAT_ID
)
1970 values
[n
++] = primary_event_id(sub
);
1972 size
= n
* sizeof(u64
);
1974 if (copy_to_user(buf
+ ret
, values
, size
)) {
1982 mutex_unlock(&ctx
->mutex
);
1987 static int perf_event_read_one(struct perf_event
*event
,
1988 u64 read_format
, char __user
*buf
)
1990 u64 enabled
, running
;
1994 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
1995 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1996 values
[n
++] = enabled
;
1997 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1998 values
[n
++] = running
;
1999 if (read_format
& PERF_FORMAT_ID
)
2000 values
[n
++] = primary_event_id(event
);
2002 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2005 return n
* sizeof(u64
);
2009 * Read the performance event - simple non blocking version for now
2012 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2014 u64 read_format
= event
->attr
.read_format
;
2018 * Return end-of-file for a read on a event that is in
2019 * error state (i.e. because it was pinned but it couldn't be
2020 * scheduled on to the CPU at some point).
2022 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2025 if (count
< perf_event_read_size(event
))
2028 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2029 if (read_format
& PERF_FORMAT_GROUP
)
2030 ret
= perf_event_read_group(event
, read_format
, buf
);
2032 ret
= perf_event_read_one(event
, read_format
, buf
);
2038 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2040 struct perf_event
*event
= file
->private_data
;
2042 return perf_read_hw(event
, buf
, count
);
2045 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2047 struct perf_event
*event
= file
->private_data
;
2048 struct perf_mmap_data
*data
;
2049 unsigned int events
= POLL_HUP
;
2052 data
= rcu_dereference(event
->data
);
2054 events
= atomic_xchg(&data
->poll
, 0);
2057 poll_wait(file
, &event
->waitq
, wait
);
2062 static void perf_event_reset(struct perf_event
*event
)
2064 (void)perf_event_read(event
);
2065 atomic64_set(&event
->count
, 0);
2066 perf_event_update_userpage(event
);
2070 * Holding the top-level event's child_mutex means that any
2071 * descendant process that has inherited this event will block
2072 * in sync_child_event if it goes to exit, thus satisfying the
2073 * task existence requirements of perf_event_enable/disable.
2075 static void perf_event_for_each_child(struct perf_event
*event
,
2076 void (*func
)(struct perf_event
*))
2078 struct perf_event
*child
;
2080 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2081 mutex_lock(&event
->child_mutex
);
2083 list_for_each_entry(child
, &event
->child_list
, child_list
)
2085 mutex_unlock(&event
->child_mutex
);
2088 static void perf_event_for_each(struct perf_event
*event
,
2089 void (*func
)(struct perf_event
*))
2091 struct perf_event_context
*ctx
= event
->ctx
;
2092 struct perf_event
*sibling
;
2094 WARN_ON_ONCE(ctx
->parent_ctx
);
2095 mutex_lock(&ctx
->mutex
);
2096 event
= event
->group_leader
;
2098 perf_event_for_each_child(event
, func
);
2100 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
2101 perf_event_for_each_child(event
, func
);
2102 mutex_unlock(&ctx
->mutex
);
2105 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
2107 struct perf_event_context
*ctx
= event
->ctx
;
2112 if (!event
->attr
.sample_period
)
2115 size
= copy_from_user(&value
, arg
, sizeof(value
));
2116 if (size
!= sizeof(value
))
2122 raw_spin_lock_irq(&ctx
->lock
);
2123 if (event
->attr
.freq
) {
2124 if (value
> sysctl_perf_event_sample_rate
) {
2129 event
->attr
.sample_freq
= value
;
2131 event
->attr
.sample_period
= value
;
2132 event
->hw
.sample_period
= value
;
2135 raw_spin_unlock_irq(&ctx
->lock
);
2140 static int perf_event_set_output(struct perf_event
*event
, int output_fd
);
2141 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
2143 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2145 struct perf_event
*event
= file
->private_data
;
2146 void (*func
)(struct perf_event
*);
2150 case PERF_EVENT_IOC_ENABLE
:
2151 func
= perf_event_enable
;
2153 case PERF_EVENT_IOC_DISABLE
:
2154 func
= perf_event_disable
;
2156 case PERF_EVENT_IOC_RESET
:
2157 func
= perf_event_reset
;
2160 case PERF_EVENT_IOC_REFRESH
:
2161 return perf_event_refresh(event
, arg
);
2163 case PERF_EVENT_IOC_PERIOD
:
2164 return perf_event_period(event
, (u64 __user
*)arg
);
2166 case PERF_EVENT_IOC_SET_OUTPUT
:
2167 return perf_event_set_output(event
, arg
);
2169 case PERF_EVENT_IOC_SET_FILTER
:
2170 return perf_event_set_filter(event
, (void __user
*)arg
);
2176 if (flags
& PERF_IOC_FLAG_GROUP
)
2177 perf_event_for_each(event
, func
);
2179 perf_event_for_each_child(event
, func
);
2184 int perf_event_task_enable(void)
2186 struct perf_event
*event
;
2188 mutex_lock(¤t
->perf_event_mutex
);
2189 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2190 perf_event_for_each_child(event
, perf_event_enable
);
2191 mutex_unlock(¤t
->perf_event_mutex
);
2196 int perf_event_task_disable(void)
2198 struct perf_event
*event
;
2200 mutex_lock(¤t
->perf_event_mutex
);
2201 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2202 perf_event_for_each_child(event
, perf_event_disable
);
2203 mutex_unlock(¤t
->perf_event_mutex
);
2208 #ifndef PERF_EVENT_INDEX_OFFSET
2209 # define PERF_EVENT_INDEX_OFFSET 0
2212 static int perf_event_index(struct perf_event
*event
)
2214 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2217 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
2221 * Callers need to ensure there can be no nesting of this function, otherwise
2222 * the seqlock logic goes bad. We can not serialize this because the arch
2223 * code calls this from NMI context.
2225 void perf_event_update_userpage(struct perf_event
*event
)
2227 struct perf_event_mmap_page
*userpg
;
2228 struct perf_mmap_data
*data
;
2231 data
= rcu_dereference(event
->data
);
2235 userpg
= data
->user_page
;
2238 * Disable preemption so as to not let the corresponding user-space
2239 * spin too long if we get preempted.
2244 userpg
->index
= perf_event_index(event
);
2245 userpg
->offset
= atomic64_read(&event
->count
);
2246 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2247 userpg
->offset
-= atomic64_read(&event
->hw
.prev_count
);
2249 userpg
->time_enabled
= event
->total_time_enabled
+
2250 atomic64_read(&event
->child_total_time_enabled
);
2252 userpg
->time_running
= event
->total_time_running
+
2253 atomic64_read(&event
->child_total_time_running
);
2262 static unsigned long perf_data_size(struct perf_mmap_data
*data
)
2264 return data
->nr_pages
<< (PAGE_SHIFT
+ data
->data_order
);
2267 #ifndef CONFIG_PERF_USE_VMALLOC
2270 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
2273 static struct page
*
2274 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2276 if (pgoff
> data
->nr_pages
)
2280 return virt_to_page(data
->user_page
);
2282 return virt_to_page(data
->data_pages
[pgoff
- 1]);
2285 static struct perf_mmap_data
*
2286 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2288 struct perf_mmap_data
*data
;
2292 WARN_ON(atomic_read(&event
->mmap_count
));
2294 size
= sizeof(struct perf_mmap_data
);
2295 size
+= nr_pages
* sizeof(void *);
2297 data
= kzalloc(size
, GFP_KERNEL
);
2301 data
->user_page
= (void *)get_zeroed_page(GFP_KERNEL
);
2302 if (!data
->user_page
)
2303 goto fail_user_page
;
2305 for (i
= 0; i
< nr_pages
; i
++) {
2306 data
->data_pages
[i
] = (void *)get_zeroed_page(GFP_KERNEL
);
2307 if (!data
->data_pages
[i
])
2308 goto fail_data_pages
;
2311 data
->data_order
= 0;
2312 data
->nr_pages
= nr_pages
;
2317 for (i
--; i
>= 0; i
--)
2318 free_page((unsigned long)data
->data_pages
[i
]);
2320 free_page((unsigned long)data
->user_page
);
2329 static void perf_mmap_free_page(unsigned long addr
)
2331 struct page
*page
= virt_to_page((void *)addr
);
2333 page
->mapping
= NULL
;
2337 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2341 perf_mmap_free_page((unsigned long)data
->user_page
);
2342 for (i
= 0; i
< data
->nr_pages
; i
++)
2343 perf_mmap_free_page((unsigned long)data
->data_pages
[i
]);
2350 * Back perf_mmap() with vmalloc memory.
2352 * Required for architectures that have d-cache aliasing issues.
2355 static struct page
*
2356 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2358 if (pgoff
> (1UL << data
->data_order
))
2361 return vmalloc_to_page((void *)data
->user_page
+ pgoff
* PAGE_SIZE
);
2364 static void perf_mmap_unmark_page(void *addr
)
2366 struct page
*page
= vmalloc_to_page(addr
);
2368 page
->mapping
= NULL
;
2371 static void perf_mmap_data_free_work(struct work_struct
*work
)
2373 struct perf_mmap_data
*data
;
2377 data
= container_of(work
, struct perf_mmap_data
, work
);
2378 nr
= 1 << data
->data_order
;
2380 base
= data
->user_page
;
2381 for (i
= 0; i
< nr
+ 1; i
++)
2382 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
2388 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2390 schedule_work(&data
->work
);
2393 static struct perf_mmap_data
*
2394 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2396 struct perf_mmap_data
*data
;
2400 WARN_ON(atomic_read(&event
->mmap_count
));
2402 size
= sizeof(struct perf_mmap_data
);
2403 size
+= sizeof(void *);
2405 data
= kzalloc(size
, GFP_KERNEL
);
2409 INIT_WORK(&data
->work
, perf_mmap_data_free_work
);
2411 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
2415 data
->user_page
= all_buf
;
2416 data
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
2417 data
->data_order
= ilog2(nr_pages
);
2431 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
2433 struct perf_event
*event
= vma
->vm_file
->private_data
;
2434 struct perf_mmap_data
*data
;
2435 int ret
= VM_FAULT_SIGBUS
;
2437 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
2438 if (vmf
->pgoff
== 0)
2444 data
= rcu_dereference(event
->data
);
2448 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
2451 vmf
->page
= perf_mmap_to_page(data
, vmf
->pgoff
);
2455 get_page(vmf
->page
);
2456 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
2457 vmf
->page
->index
= vmf
->pgoff
;
2467 perf_mmap_data_init(struct perf_event
*event
, struct perf_mmap_data
*data
)
2469 long max_size
= perf_data_size(data
);
2471 atomic_set(&data
->lock
, -1);
2473 if (event
->attr
.watermark
) {
2474 data
->watermark
= min_t(long, max_size
,
2475 event
->attr
.wakeup_watermark
);
2478 if (!data
->watermark
)
2479 data
->watermark
= max_size
/ 2;
2482 rcu_assign_pointer(event
->data
, data
);
2485 static void perf_mmap_data_free_rcu(struct rcu_head
*rcu_head
)
2487 struct perf_mmap_data
*data
;
2489 data
= container_of(rcu_head
, struct perf_mmap_data
, rcu_head
);
2490 perf_mmap_data_free(data
);
2493 static void perf_mmap_data_release(struct perf_event
*event
)
2495 struct perf_mmap_data
*data
= event
->data
;
2497 WARN_ON(atomic_read(&event
->mmap_count
));
2499 rcu_assign_pointer(event
->data
, NULL
);
2500 call_rcu(&data
->rcu_head
, perf_mmap_data_free_rcu
);
2503 static void perf_mmap_open(struct vm_area_struct
*vma
)
2505 struct perf_event
*event
= vma
->vm_file
->private_data
;
2507 atomic_inc(&event
->mmap_count
);
2510 static void perf_mmap_close(struct vm_area_struct
*vma
)
2512 struct perf_event
*event
= vma
->vm_file
->private_data
;
2514 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2515 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
2516 unsigned long size
= perf_data_size(event
->data
);
2517 struct user_struct
*user
= current_user();
2519 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
2520 vma
->vm_mm
->locked_vm
-= event
->data
->nr_locked
;
2521 perf_mmap_data_release(event
);
2522 mutex_unlock(&event
->mmap_mutex
);
2526 static const struct vm_operations_struct perf_mmap_vmops
= {
2527 .open
= perf_mmap_open
,
2528 .close
= perf_mmap_close
,
2529 .fault
= perf_mmap_fault
,
2530 .page_mkwrite
= perf_mmap_fault
,
2533 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
2535 struct perf_event
*event
= file
->private_data
;
2536 unsigned long user_locked
, user_lock_limit
;
2537 struct user_struct
*user
= current_user();
2538 unsigned long locked
, lock_limit
;
2539 struct perf_mmap_data
*data
;
2540 unsigned long vma_size
;
2541 unsigned long nr_pages
;
2542 long user_extra
, extra
;
2545 if (!(vma
->vm_flags
& VM_SHARED
))
2548 vma_size
= vma
->vm_end
- vma
->vm_start
;
2549 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
2552 * If we have data pages ensure they're a power-of-two number, so we
2553 * can do bitmasks instead of modulo.
2555 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
2558 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
2561 if (vma
->vm_pgoff
!= 0)
2564 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2565 mutex_lock(&event
->mmap_mutex
);
2566 if (event
->output
) {
2571 if (atomic_inc_not_zero(&event
->mmap_count
)) {
2572 if (nr_pages
!= event
->data
->nr_pages
)
2577 user_extra
= nr_pages
+ 1;
2578 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
2581 * Increase the limit linearly with more CPUs:
2583 user_lock_limit
*= num_online_cpus();
2585 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
2588 if (user_locked
> user_lock_limit
)
2589 extra
= user_locked
- user_lock_limit
;
2591 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
2592 lock_limit
>>= PAGE_SHIFT
;
2593 locked
= vma
->vm_mm
->locked_vm
+ extra
;
2595 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
2596 !capable(CAP_IPC_LOCK
)) {
2601 WARN_ON(event
->data
);
2603 data
= perf_mmap_data_alloc(event
, nr_pages
);
2609 perf_mmap_data_init(event
, data
);
2611 atomic_set(&event
->mmap_count
, 1);
2612 atomic_long_add(user_extra
, &user
->locked_vm
);
2613 vma
->vm_mm
->locked_vm
+= extra
;
2614 event
->data
->nr_locked
= extra
;
2615 if (vma
->vm_flags
& VM_WRITE
)
2616 event
->data
->writable
= 1;
2619 mutex_unlock(&event
->mmap_mutex
);
2621 vma
->vm_flags
|= VM_RESERVED
;
2622 vma
->vm_ops
= &perf_mmap_vmops
;
2627 static int perf_fasync(int fd
, struct file
*filp
, int on
)
2629 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
2630 struct perf_event
*event
= filp
->private_data
;
2633 mutex_lock(&inode
->i_mutex
);
2634 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
2635 mutex_unlock(&inode
->i_mutex
);
2643 static const struct file_operations perf_fops
= {
2644 .release
= perf_release
,
2647 .unlocked_ioctl
= perf_ioctl
,
2648 .compat_ioctl
= perf_ioctl
,
2650 .fasync
= perf_fasync
,
2656 * If there's data, ensure we set the poll() state and publish everything
2657 * to user-space before waking everybody up.
2660 void perf_event_wakeup(struct perf_event
*event
)
2662 wake_up_all(&event
->waitq
);
2664 if (event
->pending_kill
) {
2665 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
2666 event
->pending_kill
= 0;
2673 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
2675 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
2676 * single linked list and use cmpxchg() to add entries lockless.
2679 static void perf_pending_event(struct perf_pending_entry
*entry
)
2681 struct perf_event
*event
= container_of(entry
,
2682 struct perf_event
, pending
);
2684 if (event
->pending_disable
) {
2685 event
->pending_disable
= 0;
2686 __perf_event_disable(event
);
2689 if (event
->pending_wakeup
) {
2690 event
->pending_wakeup
= 0;
2691 perf_event_wakeup(event
);
2695 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
2697 static DEFINE_PER_CPU(struct perf_pending_entry
*, perf_pending_head
) = {
2701 static void perf_pending_queue(struct perf_pending_entry
*entry
,
2702 void (*func
)(struct perf_pending_entry
*))
2704 struct perf_pending_entry
**head
;
2706 if (cmpxchg(&entry
->next
, NULL
, PENDING_TAIL
) != NULL
)
2711 head
= &get_cpu_var(perf_pending_head
);
2714 entry
->next
= *head
;
2715 } while (cmpxchg(head
, entry
->next
, entry
) != entry
->next
);
2717 set_perf_event_pending();
2719 put_cpu_var(perf_pending_head
);
2722 static int __perf_pending_run(void)
2724 struct perf_pending_entry
*list
;
2727 list
= xchg(&__get_cpu_var(perf_pending_head
), PENDING_TAIL
);
2728 while (list
!= PENDING_TAIL
) {
2729 void (*func
)(struct perf_pending_entry
*);
2730 struct perf_pending_entry
*entry
= list
;
2737 * Ensure we observe the unqueue before we issue the wakeup,
2738 * so that we won't be waiting forever.
2739 * -- see perf_not_pending().
2750 static inline int perf_not_pending(struct perf_event
*event
)
2753 * If we flush on whatever cpu we run, there is a chance we don't
2757 __perf_pending_run();
2761 * Ensure we see the proper queue state before going to sleep
2762 * so that we do not miss the wakeup. -- see perf_pending_handle()
2765 return event
->pending
.next
== NULL
;
2768 static void perf_pending_sync(struct perf_event
*event
)
2770 wait_event(event
->waitq
, perf_not_pending(event
));
2773 void perf_event_do_pending(void)
2775 __perf_pending_run();
2779 * Callchain support -- arch specific
2782 __weak
struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2788 void perf_arch_fetch_caller_regs(struct pt_regs
*regs
, unsigned long ip
, int skip
)
2796 static bool perf_output_space(struct perf_mmap_data
*data
, unsigned long tail
,
2797 unsigned long offset
, unsigned long head
)
2801 if (!data
->writable
)
2804 mask
= perf_data_size(data
) - 1;
2806 offset
= (offset
- tail
) & mask
;
2807 head
= (head
- tail
) & mask
;
2809 if ((int)(head
- offset
) < 0)
2815 static void perf_output_wakeup(struct perf_output_handle
*handle
)
2817 atomic_set(&handle
->data
->poll
, POLL_IN
);
2820 handle
->event
->pending_wakeup
= 1;
2821 perf_pending_queue(&handle
->event
->pending
,
2822 perf_pending_event
);
2824 perf_event_wakeup(handle
->event
);
2828 * Curious locking construct.
2830 * We need to ensure a later event_id doesn't publish a head when a former
2831 * event_id isn't done writing. However since we need to deal with NMIs we
2832 * cannot fully serialize things.
2834 * What we do is serialize between CPUs so we only have to deal with NMI
2835 * nesting on a single CPU.
2837 * We only publish the head (and generate a wakeup) when the outer-most
2838 * event_id completes.
2840 static void perf_output_lock(struct perf_output_handle
*handle
)
2842 struct perf_mmap_data
*data
= handle
->data
;
2843 int cur
, cpu
= get_cpu();
2848 cur
= atomic_cmpxchg(&data
->lock
, -1, cpu
);
2860 static void perf_output_unlock(struct perf_output_handle
*handle
)
2862 struct perf_mmap_data
*data
= handle
->data
;
2866 data
->done_head
= data
->head
;
2868 if (!handle
->locked
)
2873 * The xchg implies a full barrier that ensures all writes are done
2874 * before we publish the new head, matched by a rmb() in userspace when
2875 * reading this position.
2877 while ((head
= atomic_long_xchg(&data
->done_head
, 0)))
2878 data
->user_page
->data_head
= head
;
2881 * NMI can happen here, which means we can miss a done_head update.
2884 cpu
= atomic_xchg(&data
->lock
, -1);
2885 WARN_ON_ONCE(cpu
!= smp_processor_id());
2888 * Therefore we have to validate we did not indeed do so.
2890 if (unlikely(atomic_long_read(&data
->done_head
))) {
2892 * Since we had it locked, we can lock it again.
2894 while (atomic_cmpxchg(&data
->lock
, -1, cpu
) != -1)
2900 if (atomic_xchg(&data
->wakeup
, 0))
2901 perf_output_wakeup(handle
);
2906 void perf_output_copy(struct perf_output_handle
*handle
,
2907 const void *buf
, unsigned int len
)
2909 unsigned int pages_mask
;
2910 unsigned long offset
;
2914 offset
= handle
->offset
;
2915 pages_mask
= handle
->data
->nr_pages
- 1;
2916 pages
= handle
->data
->data_pages
;
2919 unsigned long page_offset
;
2920 unsigned long page_size
;
2923 nr
= (offset
>> PAGE_SHIFT
) & pages_mask
;
2924 page_size
= 1UL << (handle
->data
->data_order
+ PAGE_SHIFT
);
2925 page_offset
= offset
& (page_size
- 1);
2926 size
= min_t(unsigned int, page_size
- page_offset
, len
);
2928 memcpy(pages
[nr
] + page_offset
, buf
, size
);
2935 handle
->offset
= offset
;
2938 * Check we didn't copy past our reservation window, taking the
2939 * possible unsigned int wrap into account.
2941 WARN_ON_ONCE(((long)(handle
->head
- handle
->offset
)) < 0);
2944 int perf_output_begin(struct perf_output_handle
*handle
,
2945 struct perf_event
*event
, unsigned int size
,
2946 int nmi
, int sample
)
2948 struct perf_event
*output_event
;
2949 struct perf_mmap_data
*data
;
2950 unsigned long tail
, offset
, head
;
2953 struct perf_event_header header
;
2960 * For inherited events we send all the output towards the parent.
2963 event
= event
->parent
;
2965 output_event
= rcu_dereference(event
->output
);
2967 event
= output_event
;
2969 data
= rcu_dereference(event
->data
);
2973 handle
->data
= data
;
2974 handle
->event
= event
;
2976 handle
->sample
= sample
;
2978 if (!data
->nr_pages
)
2981 have_lost
= atomic_read(&data
->lost
);
2983 size
+= sizeof(lost_event
);
2985 perf_output_lock(handle
);
2989 * Userspace could choose to issue a mb() before updating the
2990 * tail pointer. So that all reads will be completed before the
2993 tail
= ACCESS_ONCE(data
->user_page
->data_tail
);
2995 offset
= head
= atomic_long_read(&data
->head
);
2997 if (unlikely(!perf_output_space(data
, tail
, offset
, head
)))
2999 } while (atomic_long_cmpxchg(&data
->head
, offset
, head
) != offset
);
3001 handle
->offset
= offset
;
3002 handle
->head
= head
;
3004 if (head
- tail
> data
->watermark
)
3005 atomic_set(&data
->wakeup
, 1);
3008 lost_event
.header
.type
= PERF_RECORD_LOST
;
3009 lost_event
.header
.misc
= 0;
3010 lost_event
.header
.size
= sizeof(lost_event
);
3011 lost_event
.id
= event
->id
;
3012 lost_event
.lost
= atomic_xchg(&data
->lost
, 0);
3014 perf_output_put(handle
, lost_event
);
3020 atomic_inc(&data
->lost
);
3021 perf_output_unlock(handle
);
3028 void perf_output_end(struct perf_output_handle
*handle
)
3030 struct perf_event
*event
= handle
->event
;
3031 struct perf_mmap_data
*data
= handle
->data
;
3033 int wakeup_events
= event
->attr
.wakeup_events
;
3035 if (handle
->sample
&& wakeup_events
) {
3036 int events
= atomic_inc_return(&data
->events
);
3037 if (events
>= wakeup_events
) {
3038 atomic_sub(wakeup_events
, &data
->events
);
3039 atomic_set(&data
->wakeup
, 1);
3043 perf_output_unlock(handle
);
3047 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
3050 * only top level events have the pid namespace they were created in
3053 event
= event
->parent
;
3055 return task_tgid_nr_ns(p
, event
->ns
);
3058 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
3061 * only top level events have the pid namespace they were created in
3064 event
= event
->parent
;
3066 return task_pid_nr_ns(p
, event
->ns
);
3069 static void perf_output_read_one(struct perf_output_handle
*handle
,
3070 struct perf_event
*event
)
3072 u64 read_format
= event
->attr
.read_format
;
3076 values
[n
++] = atomic64_read(&event
->count
);
3077 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3078 values
[n
++] = event
->total_time_enabled
+
3079 atomic64_read(&event
->child_total_time_enabled
);
3081 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3082 values
[n
++] = event
->total_time_running
+
3083 atomic64_read(&event
->child_total_time_running
);
3085 if (read_format
& PERF_FORMAT_ID
)
3086 values
[n
++] = primary_event_id(event
);
3088 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3092 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3094 static void perf_output_read_group(struct perf_output_handle
*handle
,
3095 struct perf_event
*event
)
3097 struct perf_event
*leader
= event
->group_leader
, *sub
;
3098 u64 read_format
= event
->attr
.read_format
;
3102 values
[n
++] = 1 + leader
->nr_siblings
;
3104 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3105 values
[n
++] = leader
->total_time_enabled
;
3107 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3108 values
[n
++] = leader
->total_time_running
;
3110 if (leader
!= event
)
3111 leader
->pmu
->read(leader
);
3113 values
[n
++] = atomic64_read(&leader
->count
);
3114 if (read_format
& PERF_FORMAT_ID
)
3115 values
[n
++] = primary_event_id(leader
);
3117 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3119 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3123 sub
->pmu
->read(sub
);
3125 values
[n
++] = atomic64_read(&sub
->count
);
3126 if (read_format
& PERF_FORMAT_ID
)
3127 values
[n
++] = primary_event_id(sub
);
3129 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3133 static void perf_output_read(struct perf_output_handle
*handle
,
3134 struct perf_event
*event
)
3136 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3137 perf_output_read_group(handle
, event
);
3139 perf_output_read_one(handle
, event
);
3142 void perf_output_sample(struct perf_output_handle
*handle
,
3143 struct perf_event_header
*header
,
3144 struct perf_sample_data
*data
,
3145 struct perf_event
*event
)
3147 u64 sample_type
= data
->type
;
3149 perf_output_put(handle
, *header
);
3151 if (sample_type
& PERF_SAMPLE_IP
)
3152 perf_output_put(handle
, data
->ip
);
3154 if (sample_type
& PERF_SAMPLE_TID
)
3155 perf_output_put(handle
, data
->tid_entry
);
3157 if (sample_type
& PERF_SAMPLE_TIME
)
3158 perf_output_put(handle
, data
->time
);
3160 if (sample_type
& PERF_SAMPLE_ADDR
)
3161 perf_output_put(handle
, data
->addr
);
3163 if (sample_type
& PERF_SAMPLE_ID
)
3164 perf_output_put(handle
, data
->id
);
3166 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3167 perf_output_put(handle
, data
->stream_id
);
3169 if (sample_type
& PERF_SAMPLE_CPU
)
3170 perf_output_put(handle
, data
->cpu_entry
);
3172 if (sample_type
& PERF_SAMPLE_PERIOD
)
3173 perf_output_put(handle
, data
->period
);
3175 if (sample_type
& PERF_SAMPLE_READ
)
3176 perf_output_read(handle
, event
);
3178 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3179 if (data
->callchain
) {
3182 if (data
->callchain
)
3183 size
+= data
->callchain
->nr
;
3185 size
*= sizeof(u64
);
3187 perf_output_copy(handle
, data
->callchain
, size
);
3190 perf_output_put(handle
, nr
);
3194 if (sample_type
& PERF_SAMPLE_RAW
) {
3196 perf_output_put(handle
, data
->raw
->size
);
3197 perf_output_copy(handle
, data
->raw
->data
,
3204 .size
= sizeof(u32
),
3207 perf_output_put(handle
, raw
);
3212 void perf_prepare_sample(struct perf_event_header
*header
,
3213 struct perf_sample_data
*data
,
3214 struct perf_event
*event
,
3215 struct pt_regs
*regs
)
3217 u64 sample_type
= event
->attr
.sample_type
;
3219 data
->type
= sample_type
;
3221 header
->type
= PERF_RECORD_SAMPLE
;
3222 header
->size
= sizeof(*header
);
3225 header
->misc
|= perf_misc_flags(regs
);
3227 if (sample_type
& PERF_SAMPLE_IP
) {
3228 data
->ip
= perf_instruction_pointer(regs
);
3230 header
->size
+= sizeof(data
->ip
);
3233 if (sample_type
& PERF_SAMPLE_TID
) {
3234 /* namespace issues */
3235 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3236 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3238 header
->size
+= sizeof(data
->tid_entry
);
3241 if (sample_type
& PERF_SAMPLE_TIME
) {
3242 data
->time
= perf_clock();
3244 header
->size
+= sizeof(data
->time
);
3247 if (sample_type
& PERF_SAMPLE_ADDR
)
3248 header
->size
+= sizeof(data
->addr
);
3250 if (sample_type
& PERF_SAMPLE_ID
) {
3251 data
->id
= primary_event_id(event
);
3253 header
->size
+= sizeof(data
->id
);
3256 if (sample_type
& PERF_SAMPLE_STREAM_ID
) {
3257 data
->stream_id
= event
->id
;
3259 header
->size
+= sizeof(data
->stream_id
);
3262 if (sample_type
& PERF_SAMPLE_CPU
) {
3263 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3264 data
->cpu_entry
.reserved
= 0;
3266 header
->size
+= sizeof(data
->cpu_entry
);
3269 if (sample_type
& PERF_SAMPLE_PERIOD
)
3270 header
->size
+= sizeof(data
->period
);
3272 if (sample_type
& PERF_SAMPLE_READ
)
3273 header
->size
+= perf_event_read_size(event
);
3275 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3278 data
->callchain
= perf_callchain(regs
);
3280 if (data
->callchain
)
3281 size
+= data
->callchain
->nr
;
3283 header
->size
+= size
* sizeof(u64
);
3286 if (sample_type
& PERF_SAMPLE_RAW
) {
3287 int size
= sizeof(u32
);
3290 size
+= data
->raw
->size
;
3292 size
+= sizeof(u32
);
3294 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3295 header
->size
+= size
;
3299 static void perf_event_output(struct perf_event
*event
, int nmi
,
3300 struct perf_sample_data
*data
,
3301 struct pt_regs
*regs
)
3303 struct perf_output_handle handle
;
3304 struct perf_event_header header
;
3306 perf_prepare_sample(&header
, data
, event
, regs
);
3308 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
3311 perf_output_sample(&handle
, &header
, data
, event
);
3313 perf_output_end(&handle
);
3320 struct perf_read_event
{
3321 struct perf_event_header header
;
3328 perf_event_read_event(struct perf_event
*event
,
3329 struct task_struct
*task
)
3331 struct perf_output_handle handle
;
3332 struct perf_read_event read_event
= {
3334 .type
= PERF_RECORD_READ
,
3336 .size
= sizeof(read_event
) + perf_event_read_size(event
),
3338 .pid
= perf_event_pid(event
, task
),
3339 .tid
= perf_event_tid(event
, task
),
3343 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
3347 perf_output_put(&handle
, read_event
);
3348 perf_output_read(&handle
, event
);
3350 perf_output_end(&handle
);
3354 * task tracking -- fork/exit
3356 * enabled by: attr.comm | attr.mmap | attr.task
3359 struct perf_task_event
{
3360 struct task_struct
*task
;
3361 struct perf_event_context
*task_ctx
;
3364 struct perf_event_header header
;
3374 static void perf_event_task_output(struct perf_event
*event
,
3375 struct perf_task_event
*task_event
)
3377 struct perf_output_handle handle
;
3378 struct task_struct
*task
= task_event
->task
;
3379 unsigned long flags
;
3383 * If this CPU attempts to acquire an rq lock held by a CPU spinning
3384 * in perf_output_lock() from interrupt context, it's game over.
3386 local_irq_save(flags
);
3388 size
= task_event
->event_id
.header
.size
;
3389 ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3392 local_irq_restore(flags
);
3396 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
3397 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
3399 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
3400 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
3402 perf_output_put(&handle
, task_event
->event_id
);
3404 perf_output_end(&handle
);
3405 local_irq_restore(flags
);
3408 static int perf_event_task_match(struct perf_event
*event
)
3410 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3413 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3416 if (event
->attr
.comm
|| event
->attr
.mmap
|| event
->attr
.task
)
3422 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
3423 struct perf_task_event
*task_event
)
3425 struct perf_event
*event
;
3427 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3428 if (perf_event_task_match(event
))
3429 perf_event_task_output(event
, task_event
);
3433 static void perf_event_task_event(struct perf_task_event
*task_event
)
3435 struct perf_cpu_context
*cpuctx
;
3436 struct perf_event_context
*ctx
= task_event
->task_ctx
;
3439 cpuctx
= &get_cpu_var(perf_cpu_context
);
3440 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
3442 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3444 perf_event_task_ctx(ctx
, task_event
);
3445 put_cpu_var(perf_cpu_context
);
3449 static void perf_event_task(struct task_struct
*task
,
3450 struct perf_event_context
*task_ctx
,
3453 struct perf_task_event task_event
;
3455 if (!atomic_read(&nr_comm_events
) &&
3456 !atomic_read(&nr_mmap_events
) &&
3457 !atomic_read(&nr_task_events
))
3460 task_event
= (struct perf_task_event
){
3462 .task_ctx
= task_ctx
,
3465 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
3467 .size
= sizeof(task_event
.event_id
),
3473 .time
= perf_clock(),
3477 perf_event_task_event(&task_event
);
3480 void perf_event_fork(struct task_struct
*task
)
3482 perf_event_task(task
, NULL
, 1);
3489 struct perf_comm_event
{
3490 struct task_struct
*task
;
3495 struct perf_event_header header
;
3502 static void perf_event_comm_output(struct perf_event
*event
,
3503 struct perf_comm_event
*comm_event
)
3505 struct perf_output_handle handle
;
3506 int size
= comm_event
->event_id
.header
.size
;
3507 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3512 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
3513 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
3515 perf_output_put(&handle
, comm_event
->event_id
);
3516 perf_output_copy(&handle
, comm_event
->comm
,
3517 comm_event
->comm_size
);
3518 perf_output_end(&handle
);
3521 static int perf_event_comm_match(struct perf_event
*event
)
3523 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3526 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3529 if (event
->attr
.comm
)
3535 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
3536 struct perf_comm_event
*comm_event
)
3538 struct perf_event
*event
;
3540 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3541 if (perf_event_comm_match(event
))
3542 perf_event_comm_output(event
, comm_event
);
3546 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
3548 struct perf_cpu_context
*cpuctx
;
3549 struct perf_event_context
*ctx
;
3551 char comm
[TASK_COMM_LEN
];
3553 memset(comm
, 0, sizeof(comm
));
3554 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
3555 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
3557 comm_event
->comm
= comm
;
3558 comm_event
->comm_size
= size
;
3560 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
3563 cpuctx
= &get_cpu_var(perf_cpu_context
);
3564 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
3565 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3567 perf_event_comm_ctx(ctx
, comm_event
);
3568 put_cpu_var(perf_cpu_context
);
3572 void perf_event_comm(struct task_struct
*task
)
3574 struct perf_comm_event comm_event
;
3576 if (task
->perf_event_ctxp
)
3577 perf_event_enable_on_exec(task
);
3579 if (!atomic_read(&nr_comm_events
))
3582 comm_event
= (struct perf_comm_event
){
3588 .type
= PERF_RECORD_COMM
,
3597 perf_event_comm_event(&comm_event
);
3604 struct perf_mmap_event
{
3605 struct vm_area_struct
*vma
;
3607 const char *file_name
;
3611 struct perf_event_header header
;
3621 static void perf_event_mmap_output(struct perf_event
*event
,
3622 struct perf_mmap_event
*mmap_event
)
3624 struct perf_output_handle handle
;
3625 int size
= mmap_event
->event_id
.header
.size
;
3626 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3631 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
3632 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
3634 perf_output_put(&handle
, mmap_event
->event_id
);
3635 perf_output_copy(&handle
, mmap_event
->file_name
,
3636 mmap_event
->file_size
);
3637 perf_output_end(&handle
);
3640 static int perf_event_mmap_match(struct perf_event
*event
,
3641 struct perf_mmap_event
*mmap_event
)
3643 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3646 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3649 if (event
->attr
.mmap
)
3655 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
3656 struct perf_mmap_event
*mmap_event
)
3658 struct perf_event
*event
;
3660 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3661 if (perf_event_mmap_match(event
, mmap_event
))
3662 perf_event_mmap_output(event
, mmap_event
);
3666 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
3668 struct perf_cpu_context
*cpuctx
;
3669 struct perf_event_context
*ctx
;
3670 struct vm_area_struct
*vma
= mmap_event
->vma
;
3671 struct file
*file
= vma
->vm_file
;
3677 memset(tmp
, 0, sizeof(tmp
));
3681 * d_path works from the end of the buffer backwards, so we
3682 * need to add enough zero bytes after the string to handle
3683 * the 64bit alignment we do later.
3685 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
3687 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
3690 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
3692 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
3696 if (arch_vma_name(mmap_event
->vma
)) {
3697 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
3703 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
3707 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
3712 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
3714 mmap_event
->file_name
= name
;
3715 mmap_event
->file_size
= size
;
3717 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
3720 cpuctx
= &get_cpu_var(perf_cpu_context
);
3721 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
);
3722 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3724 perf_event_mmap_ctx(ctx
, mmap_event
);
3725 put_cpu_var(perf_cpu_context
);
3731 void __perf_event_mmap(struct vm_area_struct
*vma
)
3733 struct perf_mmap_event mmap_event
;
3735 if (!atomic_read(&nr_mmap_events
))
3738 mmap_event
= (struct perf_mmap_event
){
3744 .type
= PERF_RECORD_MMAP
,
3750 .start
= vma
->vm_start
,
3751 .len
= vma
->vm_end
- vma
->vm_start
,
3752 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
3756 perf_event_mmap_event(&mmap_event
);
3760 * IRQ throttle logging
3763 static void perf_log_throttle(struct perf_event
*event
, int enable
)
3765 struct perf_output_handle handle
;
3769 struct perf_event_header header
;
3773 } throttle_event
= {
3775 .type
= PERF_RECORD_THROTTLE
,
3777 .size
= sizeof(throttle_event
),
3779 .time
= perf_clock(),
3780 .id
= primary_event_id(event
),
3781 .stream_id
= event
->id
,
3785 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
3787 ret
= perf_output_begin(&handle
, event
, sizeof(throttle_event
), 1, 0);
3791 perf_output_put(&handle
, throttle_event
);
3792 perf_output_end(&handle
);
3796 * Generic event overflow handling, sampling.
3799 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
3800 int throttle
, struct perf_sample_data
*data
,
3801 struct pt_regs
*regs
)
3803 int events
= atomic_read(&event
->event_limit
);
3804 struct hw_perf_event
*hwc
= &event
->hw
;
3807 throttle
= (throttle
&& event
->pmu
->unthrottle
!= NULL
);
3812 if (hwc
->interrupts
!= MAX_INTERRUPTS
) {
3814 if (HZ
* hwc
->interrupts
>
3815 (u64
)sysctl_perf_event_sample_rate
) {
3816 hwc
->interrupts
= MAX_INTERRUPTS
;
3817 perf_log_throttle(event
, 0);
3822 * Keep re-disabling events even though on the previous
3823 * pass we disabled it - just in case we raced with a
3824 * sched-in and the event got enabled again:
3830 if (event
->attr
.freq
) {
3831 u64 now
= perf_clock();
3832 s64 delta
= now
- hwc
->freq_time_stamp
;
3834 hwc
->freq_time_stamp
= now
;
3836 if (delta
> 0 && delta
< 2*TICK_NSEC
)
3837 perf_adjust_period(event
, delta
, hwc
->last_period
);
3841 * XXX event_limit might not quite work as expected on inherited
3845 event
->pending_kill
= POLL_IN
;
3846 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
3848 event
->pending_kill
= POLL_HUP
;
3850 event
->pending_disable
= 1;
3851 perf_pending_queue(&event
->pending
,
3852 perf_pending_event
);
3854 perf_event_disable(event
);
3857 if (event
->overflow_handler
)
3858 event
->overflow_handler(event
, nmi
, data
, regs
);
3860 perf_event_output(event
, nmi
, data
, regs
);
3865 int perf_event_overflow(struct perf_event
*event
, int nmi
,
3866 struct perf_sample_data
*data
,
3867 struct pt_regs
*regs
)
3869 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
3873 * Generic software event infrastructure
3877 * We directly increment event->count and keep a second value in
3878 * event->hw.period_left to count intervals. This period event
3879 * is kept in the range [-sample_period, 0] so that we can use the
3883 static u64
perf_swevent_set_period(struct perf_event
*event
)
3885 struct hw_perf_event
*hwc
= &event
->hw
;
3886 u64 period
= hwc
->last_period
;
3890 hwc
->last_period
= hwc
->sample_period
;
3893 old
= val
= atomic64_read(&hwc
->period_left
);
3897 nr
= div64_u64(period
+ val
, period
);
3898 offset
= nr
* period
;
3900 if (atomic64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
3906 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
3907 int nmi
, struct perf_sample_data
*data
,
3908 struct pt_regs
*regs
)
3910 struct hw_perf_event
*hwc
= &event
->hw
;
3913 data
->period
= event
->hw
.last_period
;
3915 overflow
= perf_swevent_set_period(event
);
3917 if (hwc
->interrupts
== MAX_INTERRUPTS
)
3920 for (; overflow
; overflow
--) {
3921 if (__perf_event_overflow(event
, nmi
, throttle
,
3924 * We inhibit the overflow from happening when
3925 * hwc->interrupts == MAX_INTERRUPTS.
3933 static void perf_swevent_unthrottle(struct perf_event
*event
)
3936 * Nothing to do, we already reset hwc->interrupts.
3940 static void perf_swevent_add(struct perf_event
*event
, u64 nr
,
3941 int nmi
, struct perf_sample_data
*data
,
3942 struct pt_regs
*regs
)
3944 struct hw_perf_event
*hwc
= &event
->hw
;
3946 atomic64_add(nr
, &event
->count
);
3951 if (!hwc
->sample_period
)
3954 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
3955 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
3957 if (atomic64_add_negative(nr
, &hwc
->period_left
))
3960 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
3963 static int perf_swevent_is_counting(struct perf_event
*event
)
3966 * The event is active, we're good!
3968 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3972 * The event is off/error, not counting.
3974 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
)
3978 * The event is inactive, if the context is active
3979 * we're part of a group that didn't make it on the 'pmu',
3982 if (event
->ctx
->is_active
)
3986 * We're inactive and the context is too, this means the
3987 * task is scheduled out, we're counting events that happen
3988 * to us, like migration events.
3993 static int perf_tp_event_match(struct perf_event
*event
,
3994 struct perf_sample_data
*data
);
3996 static int perf_exclude_event(struct perf_event
*event
,
3997 struct pt_regs
*regs
)
4000 if (event
->attr
.exclude_user
&& user_mode(regs
))
4003 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4010 static int perf_swevent_match(struct perf_event
*event
,
4011 enum perf_type_id type
,
4013 struct perf_sample_data
*data
,
4014 struct pt_regs
*regs
)
4016 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
4019 if (!perf_swevent_is_counting(event
))
4022 if (event
->attr
.type
!= type
)
4025 if (event
->attr
.config
!= event_id
)
4028 if (perf_exclude_event(event
, regs
))
4031 if (event
->attr
.type
== PERF_TYPE_TRACEPOINT
&&
4032 !perf_tp_event_match(event
, data
))
4038 static void perf_swevent_ctx_event(struct perf_event_context
*ctx
,
4039 enum perf_type_id type
,
4040 u32 event_id
, u64 nr
, int nmi
,
4041 struct perf_sample_data
*data
,
4042 struct pt_regs
*regs
)
4044 struct perf_event
*event
;
4046 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4047 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4048 perf_swevent_add(event
, nr
, nmi
, data
, regs
);
4052 int perf_swevent_get_recursion_context(void)
4054 struct perf_cpu_context
*cpuctx
= &get_cpu_var(perf_cpu_context
);
4061 else if (in_softirq())
4066 if (cpuctx
->recursion
[rctx
]) {
4067 put_cpu_var(perf_cpu_context
);
4071 cpuctx
->recursion
[rctx
]++;
4076 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4078 void perf_swevent_put_recursion_context(int rctx
)
4080 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
4082 cpuctx
->recursion
[rctx
]--;
4083 put_cpu_var(perf_cpu_context
);
4085 EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context
);
4087 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4089 struct perf_sample_data
*data
,
4090 struct pt_regs
*regs
)
4092 struct perf_cpu_context
*cpuctx
;
4093 struct perf_event_context
*ctx
;
4095 cpuctx
= &__get_cpu_var(perf_cpu_context
);
4097 perf_swevent_ctx_event(&cpuctx
->ctx
, type
, event_id
,
4098 nr
, nmi
, data
, regs
);
4100 * doesn't really matter which of the child contexts the
4101 * events ends up in.
4103 ctx
= rcu_dereference(current
->perf_event_ctxp
);
4105 perf_swevent_ctx_event(ctx
, type
, event_id
, nr
, nmi
, data
, regs
);
4109 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
4110 struct pt_regs
*regs
, u64 addr
)
4112 struct perf_sample_data data
;
4115 rctx
= perf_swevent_get_recursion_context();
4119 perf_sample_data_init(&data
, addr
);
4121 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
4123 perf_swevent_put_recursion_context(rctx
);
4126 static void perf_swevent_read(struct perf_event
*event
)
4130 static int perf_swevent_enable(struct perf_event
*event
)
4132 struct hw_perf_event
*hwc
= &event
->hw
;
4134 if (hwc
->sample_period
) {
4135 hwc
->last_period
= hwc
->sample_period
;
4136 perf_swevent_set_period(event
);
4141 static void perf_swevent_disable(struct perf_event
*event
)
4145 static const struct pmu perf_ops_generic
= {
4146 .enable
= perf_swevent_enable
,
4147 .disable
= perf_swevent_disable
,
4148 .read
= perf_swevent_read
,
4149 .unthrottle
= perf_swevent_unthrottle
,
4153 * hrtimer based swevent callback
4156 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
4158 enum hrtimer_restart ret
= HRTIMER_RESTART
;
4159 struct perf_sample_data data
;
4160 struct pt_regs
*regs
;
4161 struct perf_event
*event
;
4164 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
4165 event
->pmu
->read(event
);
4167 perf_sample_data_init(&data
, 0);
4168 data
.period
= event
->hw
.last_period
;
4169 regs
= get_irq_regs();
4171 * In case we exclude kernel IPs or are somehow not in interrupt
4172 * context, provide the next best thing, the user IP.
4174 if ((event
->attr
.exclude_kernel
|| !regs
) &&
4175 !event
->attr
.exclude_user
)
4176 regs
= task_pt_regs(current
);
4179 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
4180 if (perf_event_overflow(event
, 0, &data
, regs
))
4181 ret
= HRTIMER_NORESTART
;
4184 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
4185 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
4190 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
4192 struct hw_perf_event
*hwc
= &event
->hw
;
4194 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
4195 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
4196 if (hwc
->sample_period
) {
4199 if (hwc
->remaining
) {
4200 if (hwc
->remaining
< 0)
4203 period
= hwc
->remaining
;
4206 period
= max_t(u64
, 10000, hwc
->sample_period
);
4208 __hrtimer_start_range_ns(&hwc
->hrtimer
,
4209 ns_to_ktime(period
), 0,
4210 HRTIMER_MODE_REL
, 0);
4214 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
4216 struct hw_perf_event
*hwc
= &event
->hw
;
4218 if (hwc
->sample_period
) {
4219 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
4220 hwc
->remaining
= ktime_to_ns(remaining
);
4222 hrtimer_cancel(&hwc
->hrtimer
);
4227 * Software event: cpu wall time clock
4230 static void cpu_clock_perf_event_update(struct perf_event
*event
)
4232 int cpu
= raw_smp_processor_id();
4236 now
= cpu_clock(cpu
);
4237 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4238 atomic64_add(now
- prev
, &event
->count
);
4241 static int cpu_clock_perf_event_enable(struct perf_event
*event
)
4243 struct hw_perf_event
*hwc
= &event
->hw
;
4244 int cpu
= raw_smp_processor_id();
4246 atomic64_set(&hwc
->prev_count
, cpu_clock(cpu
));
4247 perf_swevent_start_hrtimer(event
);
4252 static void cpu_clock_perf_event_disable(struct perf_event
*event
)
4254 perf_swevent_cancel_hrtimer(event
);
4255 cpu_clock_perf_event_update(event
);
4258 static void cpu_clock_perf_event_read(struct perf_event
*event
)
4260 cpu_clock_perf_event_update(event
);
4263 static const struct pmu perf_ops_cpu_clock
= {
4264 .enable
= cpu_clock_perf_event_enable
,
4265 .disable
= cpu_clock_perf_event_disable
,
4266 .read
= cpu_clock_perf_event_read
,
4270 * Software event: task time clock
4273 static void task_clock_perf_event_update(struct perf_event
*event
, u64 now
)
4278 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4280 atomic64_add(delta
, &event
->count
);
4283 static int task_clock_perf_event_enable(struct perf_event
*event
)
4285 struct hw_perf_event
*hwc
= &event
->hw
;
4288 now
= event
->ctx
->time
;
4290 atomic64_set(&hwc
->prev_count
, now
);
4292 perf_swevent_start_hrtimer(event
);
4297 static void task_clock_perf_event_disable(struct perf_event
*event
)
4299 perf_swevent_cancel_hrtimer(event
);
4300 task_clock_perf_event_update(event
, event
->ctx
->time
);
4304 static void task_clock_perf_event_read(struct perf_event
*event
)
4309 update_context_time(event
->ctx
);
4310 time
= event
->ctx
->time
;
4312 u64 now
= perf_clock();
4313 u64 delta
= now
- event
->ctx
->timestamp
;
4314 time
= event
->ctx
->time
+ delta
;
4317 task_clock_perf_event_update(event
, time
);
4320 static const struct pmu perf_ops_task_clock
= {
4321 .enable
= task_clock_perf_event_enable
,
4322 .disable
= task_clock_perf_event_disable
,
4323 .read
= task_clock_perf_event_read
,
4326 #ifdef CONFIG_EVENT_TRACING
4328 void perf_tp_event(int event_id
, u64 addr
, u64 count
, void *record
,
4329 int entry_size
, struct pt_regs
*regs
)
4331 struct perf_sample_data data
;
4332 struct perf_raw_record raw
= {
4337 perf_sample_data_init(&data
, addr
);
4340 /* Trace events already protected against recursion */
4341 do_perf_sw_event(PERF_TYPE_TRACEPOINT
, event_id
, count
, 1,
4344 EXPORT_SYMBOL_GPL(perf_tp_event
);
4346 static int perf_tp_event_match(struct perf_event
*event
,
4347 struct perf_sample_data
*data
)
4349 void *record
= data
->raw
->data
;
4351 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
4356 static void tp_perf_event_destroy(struct perf_event
*event
)
4358 perf_trace_disable(event
->attr
.config
);
4361 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4364 * Raw tracepoint data is a severe data leak, only allow root to
4367 if ((event
->attr
.sample_type
& PERF_SAMPLE_RAW
) &&
4368 perf_paranoid_tracepoint_raw() &&
4369 !capable(CAP_SYS_ADMIN
))
4370 return ERR_PTR(-EPERM
);
4372 if (perf_trace_enable(event
->attr
.config
))
4375 event
->destroy
= tp_perf_event_destroy
;
4377 return &perf_ops_generic
;
4380 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4385 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4388 filter_str
= strndup_user(arg
, PAGE_SIZE
);
4389 if (IS_ERR(filter_str
))
4390 return PTR_ERR(filter_str
);
4392 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
4398 static void perf_event_free_filter(struct perf_event
*event
)
4400 ftrace_profile_free_filter(event
);
4405 static int perf_tp_event_match(struct perf_event
*event
,
4406 struct perf_sample_data
*data
)
4411 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4416 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4421 static void perf_event_free_filter(struct perf_event
*event
)
4425 #endif /* CONFIG_EVENT_TRACING */
4427 #ifdef CONFIG_HAVE_HW_BREAKPOINT
4428 static void bp_perf_event_destroy(struct perf_event
*event
)
4430 release_bp_slot(event
);
4433 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4437 err
= register_perf_hw_breakpoint(bp
);
4439 return ERR_PTR(err
);
4441 bp
->destroy
= bp_perf_event_destroy
;
4443 return &perf_ops_bp
;
4446 void perf_bp_event(struct perf_event
*bp
, void *data
)
4448 struct perf_sample_data sample
;
4449 struct pt_regs
*regs
= data
;
4451 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
4453 if (!perf_exclude_event(bp
, regs
))
4454 perf_swevent_add(bp
, 1, 1, &sample
, regs
);
4457 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4462 void perf_bp_event(struct perf_event
*bp
, void *regs
)
4467 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4469 static void sw_perf_event_destroy(struct perf_event
*event
)
4471 u64 event_id
= event
->attr
.config
;
4473 WARN_ON(event
->parent
);
4475 atomic_dec(&perf_swevent_enabled
[event_id
]);
4478 static const struct pmu
*sw_perf_event_init(struct perf_event
*event
)
4480 const struct pmu
*pmu
= NULL
;
4481 u64 event_id
= event
->attr
.config
;
4484 * Software events (currently) can't in general distinguish
4485 * between user, kernel and hypervisor events.
4486 * However, context switches and cpu migrations are considered
4487 * to be kernel events, and page faults are never hypervisor
4491 case PERF_COUNT_SW_CPU_CLOCK
:
4492 pmu
= &perf_ops_cpu_clock
;
4495 case PERF_COUNT_SW_TASK_CLOCK
:
4497 * If the user instantiates this as a per-cpu event,
4498 * use the cpu_clock event instead.
4500 if (event
->ctx
->task
)
4501 pmu
= &perf_ops_task_clock
;
4503 pmu
= &perf_ops_cpu_clock
;
4506 case PERF_COUNT_SW_PAGE_FAULTS
:
4507 case PERF_COUNT_SW_PAGE_FAULTS_MIN
:
4508 case PERF_COUNT_SW_PAGE_FAULTS_MAJ
:
4509 case PERF_COUNT_SW_CONTEXT_SWITCHES
:
4510 case PERF_COUNT_SW_CPU_MIGRATIONS
:
4511 case PERF_COUNT_SW_ALIGNMENT_FAULTS
:
4512 case PERF_COUNT_SW_EMULATION_FAULTS
:
4513 if (!event
->parent
) {
4514 atomic_inc(&perf_swevent_enabled
[event_id
]);
4515 event
->destroy
= sw_perf_event_destroy
;
4517 pmu
= &perf_ops_generic
;
4525 * Allocate and initialize a event structure
4527 static struct perf_event
*
4528 perf_event_alloc(struct perf_event_attr
*attr
,
4530 struct perf_event_context
*ctx
,
4531 struct perf_event
*group_leader
,
4532 struct perf_event
*parent_event
,
4533 perf_overflow_handler_t overflow_handler
,
4536 const struct pmu
*pmu
;
4537 struct perf_event
*event
;
4538 struct hw_perf_event
*hwc
;
4541 event
= kzalloc(sizeof(*event
), gfpflags
);
4543 return ERR_PTR(-ENOMEM
);
4546 * Single events are their own group leaders, with an
4547 * empty sibling list:
4550 group_leader
= event
;
4552 mutex_init(&event
->child_mutex
);
4553 INIT_LIST_HEAD(&event
->child_list
);
4555 INIT_LIST_HEAD(&event
->group_entry
);
4556 INIT_LIST_HEAD(&event
->event_entry
);
4557 INIT_LIST_HEAD(&event
->sibling_list
);
4558 init_waitqueue_head(&event
->waitq
);
4560 mutex_init(&event
->mmap_mutex
);
4563 event
->attr
= *attr
;
4564 event
->group_leader
= group_leader
;
4569 event
->parent
= parent_event
;
4571 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
4572 event
->id
= atomic64_inc_return(&perf_event_id
);
4574 event
->state
= PERF_EVENT_STATE_INACTIVE
;
4576 if (!overflow_handler
&& parent_event
)
4577 overflow_handler
= parent_event
->overflow_handler
;
4579 event
->overflow_handler
= overflow_handler
;
4582 event
->state
= PERF_EVENT_STATE_OFF
;
4587 hwc
->sample_period
= attr
->sample_period
;
4588 if (attr
->freq
&& attr
->sample_freq
)
4589 hwc
->sample_period
= 1;
4590 hwc
->last_period
= hwc
->sample_period
;
4592 atomic64_set(&hwc
->period_left
, hwc
->sample_period
);
4595 * we currently do not support PERF_FORMAT_GROUP on inherited events
4597 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
4600 switch (attr
->type
) {
4602 case PERF_TYPE_HARDWARE
:
4603 case PERF_TYPE_HW_CACHE
:
4604 pmu
= hw_perf_event_init(event
);
4607 case PERF_TYPE_SOFTWARE
:
4608 pmu
= sw_perf_event_init(event
);
4611 case PERF_TYPE_TRACEPOINT
:
4612 pmu
= tp_perf_event_init(event
);
4615 case PERF_TYPE_BREAKPOINT
:
4616 pmu
= bp_perf_event_init(event
);
4627 else if (IS_ERR(pmu
))
4632 put_pid_ns(event
->ns
);
4634 return ERR_PTR(err
);
4639 if (!event
->parent
) {
4640 atomic_inc(&nr_events
);
4641 if (event
->attr
.mmap
)
4642 atomic_inc(&nr_mmap_events
);
4643 if (event
->attr
.comm
)
4644 atomic_inc(&nr_comm_events
);
4645 if (event
->attr
.task
)
4646 atomic_inc(&nr_task_events
);
4652 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
4653 struct perf_event_attr
*attr
)
4658 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
4662 * zero the full structure, so that a short copy will be nice.
4664 memset(attr
, 0, sizeof(*attr
));
4666 ret
= get_user(size
, &uattr
->size
);
4670 if (size
> PAGE_SIZE
) /* silly large */
4673 if (!size
) /* abi compat */
4674 size
= PERF_ATTR_SIZE_VER0
;
4676 if (size
< PERF_ATTR_SIZE_VER0
)
4680 * If we're handed a bigger struct than we know of,
4681 * ensure all the unknown bits are 0 - i.e. new
4682 * user-space does not rely on any kernel feature
4683 * extensions we dont know about yet.
4685 if (size
> sizeof(*attr
)) {
4686 unsigned char __user
*addr
;
4687 unsigned char __user
*end
;
4690 addr
= (void __user
*)uattr
+ sizeof(*attr
);
4691 end
= (void __user
*)uattr
+ size
;
4693 for (; addr
< end
; addr
++) {
4694 ret
= get_user(val
, addr
);
4700 size
= sizeof(*attr
);
4703 ret
= copy_from_user(attr
, uattr
, size
);
4708 * If the type exists, the corresponding creation will verify
4711 if (attr
->type
>= PERF_TYPE_MAX
)
4714 if (attr
->__reserved_1
)
4717 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
4720 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
4727 put_user(sizeof(*attr
), &uattr
->size
);
4732 static int perf_event_set_output(struct perf_event
*event
, int output_fd
)
4734 struct perf_event
*output_event
= NULL
;
4735 struct file
*output_file
= NULL
;
4736 struct perf_event
*old_output
;
4737 int fput_needed
= 0;
4743 output_file
= fget_light(output_fd
, &fput_needed
);
4747 if (output_file
->f_op
!= &perf_fops
)
4750 output_event
= output_file
->private_data
;
4752 /* Don't chain output fds */
4753 if (output_event
->output
)
4756 /* Don't set an output fd when we already have an output channel */
4760 atomic_long_inc(&output_file
->f_count
);
4763 mutex_lock(&event
->mmap_mutex
);
4764 old_output
= event
->output
;
4765 rcu_assign_pointer(event
->output
, output_event
);
4766 mutex_unlock(&event
->mmap_mutex
);
4770 * we need to make sure no existing perf_output_*()
4771 * is still referencing this event.
4774 fput(old_output
->filp
);
4779 fput_light(output_file
, fput_needed
);
4784 * sys_perf_event_open - open a performance event, associate it to a task/cpu
4786 * @attr_uptr: event_id type attributes for monitoring/sampling
4789 * @group_fd: group leader event fd
4791 SYSCALL_DEFINE5(perf_event_open
,
4792 struct perf_event_attr __user
*, attr_uptr
,
4793 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
4795 struct perf_event
*event
, *group_leader
;
4796 struct perf_event_attr attr
;
4797 struct perf_event_context
*ctx
;
4798 struct file
*event_file
= NULL
;
4799 struct file
*group_file
= NULL
;
4800 int fput_needed
= 0;
4801 int fput_needed2
= 0;
4804 /* for future expandability... */
4805 if (flags
& ~(PERF_FLAG_FD_NO_GROUP
| PERF_FLAG_FD_OUTPUT
))
4808 err
= perf_copy_attr(attr_uptr
, &attr
);
4812 if (!attr
.exclude_kernel
) {
4813 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
4818 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
4823 * Get the target context (task or percpu):
4825 ctx
= find_get_context(pid
, cpu
);
4827 return PTR_ERR(ctx
);
4830 * Look up the group leader (we will attach this event to it):
4832 group_leader
= NULL
;
4833 if (group_fd
!= -1 && !(flags
& PERF_FLAG_FD_NO_GROUP
)) {
4835 group_file
= fget_light(group_fd
, &fput_needed
);
4837 goto err_put_context
;
4838 if (group_file
->f_op
!= &perf_fops
)
4839 goto err_put_context
;
4841 group_leader
= group_file
->private_data
;
4843 * Do not allow a recursive hierarchy (this new sibling
4844 * becoming part of another group-sibling):
4846 if (group_leader
->group_leader
!= group_leader
)
4847 goto err_put_context
;
4849 * Do not allow to attach to a group in a different
4850 * task or CPU context:
4852 if (group_leader
->ctx
!= ctx
)
4853 goto err_put_context
;
4855 * Only a group leader can be exclusive or pinned
4857 if (attr
.exclusive
|| attr
.pinned
)
4858 goto err_put_context
;
4861 event
= perf_event_alloc(&attr
, cpu
, ctx
, group_leader
,
4862 NULL
, NULL
, GFP_KERNEL
);
4863 err
= PTR_ERR(event
);
4865 goto err_put_context
;
4867 err
= anon_inode_getfd("[perf_event]", &perf_fops
, event
, O_RDWR
);
4869 goto err_free_put_context
;
4871 event_file
= fget_light(err
, &fput_needed2
);
4873 goto err_free_put_context
;
4875 if (flags
& PERF_FLAG_FD_OUTPUT
) {
4876 err
= perf_event_set_output(event
, group_fd
);
4878 goto err_fput_free_put_context
;
4881 event
->filp
= event_file
;
4882 WARN_ON_ONCE(ctx
->parent_ctx
);
4883 mutex_lock(&ctx
->mutex
);
4884 perf_install_in_context(ctx
, event
, cpu
);
4886 mutex_unlock(&ctx
->mutex
);
4888 event
->owner
= current
;
4889 get_task_struct(current
);
4890 mutex_lock(¤t
->perf_event_mutex
);
4891 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
4892 mutex_unlock(¤t
->perf_event_mutex
);
4894 err_fput_free_put_context
:
4895 fput_light(event_file
, fput_needed2
);
4897 err_free_put_context
:
4905 fput_light(group_file
, fput_needed
);
4911 * perf_event_create_kernel_counter
4913 * @attr: attributes of the counter to create
4914 * @cpu: cpu in which the counter is bound
4915 * @pid: task to profile
4918 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
4920 perf_overflow_handler_t overflow_handler
)
4922 struct perf_event
*event
;
4923 struct perf_event_context
*ctx
;
4927 * Get the target context (task or percpu):
4930 ctx
= find_get_context(pid
, cpu
);
4936 event
= perf_event_alloc(attr
, cpu
, ctx
, NULL
,
4937 NULL
, overflow_handler
, GFP_KERNEL
);
4938 if (IS_ERR(event
)) {
4939 err
= PTR_ERR(event
);
4940 goto err_put_context
;
4944 WARN_ON_ONCE(ctx
->parent_ctx
);
4945 mutex_lock(&ctx
->mutex
);
4946 perf_install_in_context(ctx
, event
, cpu
);
4948 mutex_unlock(&ctx
->mutex
);
4950 event
->owner
= current
;
4951 get_task_struct(current
);
4952 mutex_lock(¤t
->perf_event_mutex
);
4953 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
4954 mutex_unlock(¤t
->perf_event_mutex
);
4961 return ERR_PTR(err
);
4963 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
4966 * inherit a event from parent task to child task:
4968 static struct perf_event
*
4969 inherit_event(struct perf_event
*parent_event
,
4970 struct task_struct
*parent
,
4971 struct perf_event_context
*parent_ctx
,
4972 struct task_struct
*child
,
4973 struct perf_event
*group_leader
,
4974 struct perf_event_context
*child_ctx
)
4976 struct perf_event
*child_event
;
4979 * Instead of creating recursive hierarchies of events,
4980 * we link inherited events back to the original parent,
4981 * which has a filp for sure, which we use as the reference
4984 if (parent_event
->parent
)
4985 parent_event
= parent_event
->parent
;
4987 child_event
= perf_event_alloc(&parent_event
->attr
,
4988 parent_event
->cpu
, child_ctx
,
4989 group_leader
, parent_event
,
4991 if (IS_ERR(child_event
))
4996 * Make the child state follow the state of the parent event,
4997 * not its attr.disabled bit. We hold the parent's mutex,
4998 * so we won't race with perf_event_{en, dis}able_family.
5000 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
5001 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
5003 child_event
->state
= PERF_EVENT_STATE_OFF
;
5005 if (parent_event
->attr
.freq
) {
5006 u64 sample_period
= parent_event
->hw
.sample_period
;
5007 struct hw_perf_event
*hwc
= &child_event
->hw
;
5009 hwc
->sample_period
= sample_period
;
5010 hwc
->last_period
= sample_period
;
5012 atomic64_set(&hwc
->period_left
, sample_period
);
5015 child_event
->overflow_handler
= parent_event
->overflow_handler
;
5018 * Link it up in the child's context:
5020 add_event_to_ctx(child_event
, child_ctx
);
5023 * Get a reference to the parent filp - we will fput it
5024 * when the child event exits. This is safe to do because
5025 * we are in the parent and we know that the filp still
5026 * exists and has a nonzero count:
5028 atomic_long_inc(&parent_event
->filp
->f_count
);
5031 * Link this into the parent event's child list
5033 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5034 mutex_lock(&parent_event
->child_mutex
);
5035 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
5036 mutex_unlock(&parent_event
->child_mutex
);
5041 static int inherit_group(struct perf_event
*parent_event
,
5042 struct task_struct
*parent
,
5043 struct perf_event_context
*parent_ctx
,
5044 struct task_struct
*child
,
5045 struct perf_event_context
*child_ctx
)
5047 struct perf_event
*leader
;
5048 struct perf_event
*sub
;
5049 struct perf_event
*child_ctr
;
5051 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
5052 child
, NULL
, child_ctx
);
5054 return PTR_ERR(leader
);
5055 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
5056 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
5057 child
, leader
, child_ctx
);
5058 if (IS_ERR(child_ctr
))
5059 return PTR_ERR(child_ctr
);
5064 static void sync_child_event(struct perf_event
*child_event
,
5065 struct task_struct
*child
)
5067 struct perf_event
*parent_event
= child_event
->parent
;
5070 if (child_event
->attr
.inherit_stat
)
5071 perf_event_read_event(child_event
, child
);
5073 child_val
= atomic64_read(&child_event
->count
);
5076 * Add back the child's count to the parent's count:
5078 atomic64_add(child_val
, &parent_event
->count
);
5079 atomic64_add(child_event
->total_time_enabled
,
5080 &parent_event
->child_total_time_enabled
);
5081 atomic64_add(child_event
->total_time_running
,
5082 &parent_event
->child_total_time_running
);
5085 * Remove this event from the parent's list
5087 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5088 mutex_lock(&parent_event
->child_mutex
);
5089 list_del_init(&child_event
->child_list
);
5090 mutex_unlock(&parent_event
->child_mutex
);
5093 * Release the parent event, if this was the last
5096 fput(parent_event
->filp
);
5100 __perf_event_exit_task(struct perf_event
*child_event
,
5101 struct perf_event_context
*child_ctx
,
5102 struct task_struct
*child
)
5104 struct perf_event
*parent_event
;
5106 perf_event_remove_from_context(child_event
);
5108 parent_event
= child_event
->parent
;
5110 * It can happen that parent exits first, and has events
5111 * that are still around due to the child reference. These
5112 * events need to be zapped - but otherwise linger.
5115 sync_child_event(child_event
, child
);
5116 free_event(child_event
);
5121 * When a child task exits, feed back event values to parent events.
5123 void perf_event_exit_task(struct task_struct
*child
)
5125 struct perf_event
*child_event
, *tmp
;
5126 struct perf_event_context
*child_ctx
;
5127 unsigned long flags
;
5129 if (likely(!child
->perf_event_ctxp
)) {
5130 perf_event_task(child
, NULL
, 0);
5134 local_irq_save(flags
);
5136 * We can't reschedule here because interrupts are disabled,
5137 * and either child is current or it is a task that can't be
5138 * scheduled, so we are now safe from rescheduling changing
5141 child_ctx
= child
->perf_event_ctxp
;
5142 __perf_event_task_sched_out(child_ctx
);
5145 * Take the context lock here so that if find_get_context is
5146 * reading child->perf_event_ctxp, we wait until it has
5147 * incremented the context's refcount before we do put_ctx below.
5149 raw_spin_lock(&child_ctx
->lock
);
5150 child
->perf_event_ctxp
= NULL
;
5152 * If this context is a clone; unclone it so it can't get
5153 * swapped to another process while we're removing all
5154 * the events from it.
5156 unclone_ctx(child_ctx
);
5157 update_context_time(child_ctx
);
5158 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
5161 * Report the task dead after unscheduling the events so that we
5162 * won't get any samples after PERF_RECORD_EXIT. We can however still
5163 * get a few PERF_RECORD_READ events.
5165 perf_event_task(child
, child_ctx
, 0);
5168 * We can recurse on the same lock type through:
5170 * __perf_event_exit_task()
5171 * sync_child_event()
5172 * fput(parent_event->filp)
5174 * mutex_lock(&ctx->mutex)
5176 * But since its the parent context it won't be the same instance.
5178 mutex_lock_nested(&child_ctx
->mutex
, SINGLE_DEPTH_NESTING
);
5181 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
5183 __perf_event_exit_task(child_event
, child_ctx
, child
);
5185 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
5187 __perf_event_exit_task(child_event
, child_ctx
, child
);
5190 * If the last event was a group event, it will have appended all
5191 * its siblings to the list, but we obtained 'tmp' before that which
5192 * will still point to the list head terminating the iteration.
5194 if (!list_empty(&child_ctx
->pinned_groups
) ||
5195 !list_empty(&child_ctx
->flexible_groups
))
5198 mutex_unlock(&child_ctx
->mutex
);
5203 static void perf_free_event(struct perf_event
*event
,
5204 struct perf_event_context
*ctx
)
5206 struct perf_event
*parent
= event
->parent
;
5208 if (WARN_ON_ONCE(!parent
))
5211 mutex_lock(&parent
->child_mutex
);
5212 list_del_init(&event
->child_list
);
5213 mutex_unlock(&parent
->child_mutex
);
5217 list_del_event(event
, ctx
);
5222 * free an unexposed, unused context as created by inheritance by
5223 * init_task below, used by fork() in case of fail.
5225 void perf_event_free_task(struct task_struct
*task
)
5227 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
5228 struct perf_event
*event
, *tmp
;
5233 mutex_lock(&ctx
->mutex
);
5235 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5236 perf_free_event(event
, ctx
);
5238 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
5240 perf_free_event(event
, ctx
);
5242 if (!list_empty(&ctx
->pinned_groups
) ||
5243 !list_empty(&ctx
->flexible_groups
))
5246 mutex_unlock(&ctx
->mutex
);
5252 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
5253 struct perf_event_context
*parent_ctx
,
5254 struct task_struct
*child
,
5258 struct perf_event_context
*child_ctx
= child
->perf_event_ctxp
;
5260 if (!event
->attr
.inherit
) {
5267 * This is executed from the parent task context, so
5268 * inherit events that have been marked for cloning.
5269 * First allocate and initialize a context for the
5273 child_ctx
= kzalloc(sizeof(struct perf_event_context
),
5278 __perf_event_init_context(child_ctx
, child
);
5279 child
->perf_event_ctxp
= child_ctx
;
5280 get_task_struct(child
);
5283 ret
= inherit_group(event
, parent
, parent_ctx
,
5294 * Initialize the perf_event context in task_struct
5296 int perf_event_init_task(struct task_struct
*child
)
5298 struct perf_event_context
*child_ctx
, *parent_ctx
;
5299 struct perf_event_context
*cloned_ctx
;
5300 struct perf_event
*event
;
5301 struct task_struct
*parent
= current
;
5302 int inherited_all
= 1;
5305 child
->perf_event_ctxp
= NULL
;
5307 mutex_init(&child
->perf_event_mutex
);
5308 INIT_LIST_HEAD(&child
->perf_event_list
);
5310 if (likely(!parent
->perf_event_ctxp
))
5314 * If the parent's context is a clone, pin it so it won't get
5317 parent_ctx
= perf_pin_task_context(parent
);
5320 * No need to check if parent_ctx != NULL here; since we saw
5321 * it non-NULL earlier, the only reason for it to become NULL
5322 * is if we exit, and since we're currently in the middle of
5323 * a fork we can't be exiting at the same time.
5327 * Lock the parent list. No need to lock the child - not PID
5328 * hashed yet and not running, so nobody can access it.
5330 mutex_lock(&parent_ctx
->mutex
);
5333 * We dont have to disable NMIs - we are only looking at
5334 * the list, not manipulating it:
5336 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
5337 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5343 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
5344 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5350 child_ctx
= child
->perf_event_ctxp
;
5352 if (child_ctx
&& inherited_all
) {
5354 * Mark the child context as a clone of the parent
5355 * context, or of whatever the parent is a clone of.
5356 * Note that if the parent is a clone, it could get
5357 * uncloned at any point, but that doesn't matter
5358 * because the list of events and the generation
5359 * count can't have changed since we took the mutex.
5361 cloned_ctx
= rcu_dereference(parent_ctx
->parent_ctx
);
5363 child_ctx
->parent_ctx
= cloned_ctx
;
5364 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
5366 child_ctx
->parent_ctx
= parent_ctx
;
5367 child_ctx
->parent_gen
= parent_ctx
->generation
;
5369 get_ctx(child_ctx
->parent_ctx
);
5372 mutex_unlock(&parent_ctx
->mutex
);
5374 perf_unpin_context(parent_ctx
);
5379 static void __init
perf_event_init_all_cpus(void)
5382 struct perf_cpu_context
*cpuctx
;
5384 for_each_possible_cpu(cpu
) {
5385 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5386 __perf_event_init_context(&cpuctx
->ctx
, NULL
);
5390 static void __cpuinit
perf_event_init_cpu(int cpu
)
5392 struct perf_cpu_context
*cpuctx
;
5394 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5396 spin_lock(&perf_resource_lock
);
5397 cpuctx
->max_pertask
= perf_max_events
- perf_reserved_percpu
;
5398 spin_unlock(&perf_resource_lock
);
5401 #ifdef CONFIG_HOTPLUG_CPU
5402 static void __perf_event_exit_cpu(void *info
)
5404 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
5405 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5406 struct perf_event
*event
, *tmp
;
5408 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5409 __perf_event_remove_from_context(event
);
5410 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
5411 __perf_event_remove_from_context(event
);
5413 static void perf_event_exit_cpu(int cpu
)
5415 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5416 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5418 mutex_lock(&ctx
->mutex
);
5419 smp_call_function_single(cpu
, __perf_event_exit_cpu
, NULL
, 1);
5420 mutex_unlock(&ctx
->mutex
);
5423 static inline void perf_event_exit_cpu(int cpu
) { }
5426 static int __cpuinit
5427 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
5429 unsigned int cpu
= (long)hcpu
;
5433 case CPU_UP_PREPARE
:
5434 case CPU_UP_PREPARE_FROZEN
:
5435 perf_event_init_cpu(cpu
);
5438 case CPU_DOWN_PREPARE
:
5439 case CPU_DOWN_PREPARE_FROZEN
:
5440 perf_event_exit_cpu(cpu
);
5451 * This has to have a higher priority than migration_notifier in sched.c.
5453 static struct notifier_block __cpuinitdata perf_cpu_nb
= {
5454 .notifier_call
= perf_cpu_notify
,
5458 void __init
perf_event_init(void)
5460 perf_event_init_all_cpus();
5461 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_UP_PREPARE
,
5462 (void *)(long)smp_processor_id());
5463 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_ONLINE
,
5464 (void *)(long)smp_processor_id());
5465 register_cpu_notifier(&perf_cpu_nb
);
5468 static ssize_t
perf_show_reserve_percpu(struct sysdev_class
*class,
5469 struct sysdev_class_attribute
*attr
,
5472 return sprintf(buf
, "%d\n", perf_reserved_percpu
);
5476 perf_set_reserve_percpu(struct sysdev_class
*class,
5477 struct sysdev_class_attribute
*attr
,
5481 struct perf_cpu_context
*cpuctx
;
5485 err
= strict_strtoul(buf
, 10, &val
);
5488 if (val
> perf_max_events
)
5491 spin_lock(&perf_resource_lock
);
5492 perf_reserved_percpu
= val
;
5493 for_each_online_cpu(cpu
) {
5494 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5495 raw_spin_lock_irq(&cpuctx
->ctx
.lock
);
5496 mpt
= min(perf_max_events
- cpuctx
->ctx
.nr_events
,
5497 perf_max_events
- perf_reserved_percpu
);
5498 cpuctx
->max_pertask
= mpt
;
5499 raw_spin_unlock_irq(&cpuctx
->ctx
.lock
);
5501 spin_unlock(&perf_resource_lock
);
5506 static ssize_t
perf_show_overcommit(struct sysdev_class
*class,
5507 struct sysdev_class_attribute
*attr
,
5510 return sprintf(buf
, "%d\n", perf_overcommit
);
5514 perf_set_overcommit(struct sysdev_class
*class,
5515 struct sysdev_class_attribute
*attr
,
5516 const char *buf
, size_t count
)
5521 err
= strict_strtoul(buf
, 10, &val
);
5527 spin_lock(&perf_resource_lock
);
5528 perf_overcommit
= val
;
5529 spin_unlock(&perf_resource_lock
);
5534 static SYSDEV_CLASS_ATTR(
5537 perf_show_reserve_percpu
,
5538 perf_set_reserve_percpu
5541 static SYSDEV_CLASS_ATTR(
5544 perf_show_overcommit
,
5548 static struct attribute
*perfclass_attrs
[] = {
5549 &attr_reserve_percpu
.attr
,
5550 &attr_overcommit
.attr
,
5554 static struct attribute_group perfclass_attr_group
= {
5555 .attrs
= perfclass_attrs
,
5556 .name
= "perf_events",
5559 static int __init
perf_event_sysfs_init(void)
5561 return sysfs_create_group(&cpu_sysdev_class
.kset
.kobj
,
5562 &perfclass_attr_group
);
5564 device_initcall(perf_event_sysfs_init
);