2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/file.h>
17 #include <linux/poll.h>
18 #include <linux/slab.h>
19 #include <linux/sysfs.h>
20 #include <linux/dcache.h>
21 #include <linux/percpu.h>
22 #include <linux/ptrace.h>
23 #include <linux/vmstat.h>
24 #include <linux/vmalloc.h>
25 #include <linux/hardirq.h>
26 #include <linux/rculist.h>
27 #include <linux/uaccess.h>
28 #include <linux/syscalls.h>
29 #include <linux/anon_inodes.h>
30 #include <linux/kernel_stat.h>
31 #include <linux/perf_event.h>
32 #include <linux/ftrace_event.h>
33 #include <linux/hw_breakpoint.h>
35 #include <asm/irq_regs.h>
38 * Each CPU has a list of per CPU events:
40 static DEFINE_PER_CPU(struct perf_cpu_context
, perf_cpu_context
);
42 int perf_max_events __read_mostly
= 1;
43 static int perf_reserved_percpu __read_mostly
;
44 static int perf_overcommit __read_mostly
= 1;
46 static atomic_t nr_events __read_mostly
;
47 static atomic_t nr_mmap_events __read_mostly
;
48 static atomic_t nr_comm_events __read_mostly
;
49 static atomic_t nr_task_events __read_mostly
;
52 * perf event paranoia level:
53 * -1 - not paranoid at all
54 * 0 - disallow raw tracepoint access for unpriv
55 * 1 - disallow cpu events for unpriv
56 * 2 - disallow kernel profiling for unpriv
58 int sysctl_perf_event_paranoid __read_mostly
= 1;
60 int sysctl_perf_event_mlock __read_mostly
= 512; /* 'free' kb per user */
63 * max perf event sample rate
65 int sysctl_perf_event_sample_rate __read_mostly
= 100000;
67 static atomic64_t perf_event_id
;
70 * Lock for (sysadmin-configurable) event reservations:
72 static DEFINE_SPINLOCK(perf_resource_lock
);
75 * Architecture provided APIs - weak aliases:
77 extern __weak
const struct pmu
*hw_perf_event_init(struct perf_event
*event
)
82 void __weak
hw_perf_disable(void) { barrier(); }
83 void __weak
hw_perf_enable(void) { barrier(); }
86 hw_perf_group_sched_in(struct perf_event
*group_leader
,
87 struct perf_cpu_context
*cpuctx
,
88 struct perf_event_context
*ctx
)
93 void __weak
perf_event_print_debug(void) { }
95 static DEFINE_PER_CPU(int, perf_disable_count
);
97 void perf_disable(void)
99 if (!__get_cpu_var(perf_disable_count
)++)
103 void perf_enable(void)
105 if (!--__get_cpu_var(perf_disable_count
))
109 static void get_ctx(struct perf_event_context
*ctx
)
111 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
114 static void free_ctx(struct rcu_head
*head
)
116 struct perf_event_context
*ctx
;
118 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
122 static void put_ctx(struct perf_event_context
*ctx
)
124 if (atomic_dec_and_test(&ctx
->refcount
)) {
126 put_ctx(ctx
->parent_ctx
);
128 put_task_struct(ctx
->task
);
129 call_rcu(&ctx
->rcu_head
, free_ctx
);
133 static void unclone_ctx(struct perf_event_context
*ctx
)
135 if (ctx
->parent_ctx
) {
136 put_ctx(ctx
->parent_ctx
);
137 ctx
->parent_ctx
= NULL
;
142 * If we inherit events we want to return the parent event id
145 static u64
primary_event_id(struct perf_event
*event
)
150 id
= event
->parent
->id
;
156 * Get the perf_event_context for a task and lock it.
157 * This has to cope with with the fact that until it is locked,
158 * the context could get moved to another task.
160 static struct perf_event_context
*
161 perf_lock_task_context(struct task_struct
*task
, unsigned long *flags
)
163 struct perf_event_context
*ctx
;
167 ctx
= rcu_dereference(task
->perf_event_ctxp
);
170 * If this context is a clone of another, it might
171 * get swapped for another underneath us by
172 * perf_event_task_sched_out, though the
173 * rcu_read_lock() protects us from any context
174 * getting freed. Lock the context and check if it
175 * got swapped before we could get the lock, and retry
176 * if so. If we locked the right context, then it
177 * can't get swapped on us any more.
179 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
180 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
)) {
181 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
185 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
186 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
195 * Get the context for a task and increment its pin_count so it
196 * can't get swapped to another task. This also increments its
197 * reference count so that the context can't get freed.
199 static struct perf_event_context
*perf_pin_task_context(struct task_struct
*task
)
201 struct perf_event_context
*ctx
;
204 ctx
= perf_lock_task_context(task
, &flags
);
207 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
212 static void perf_unpin_context(struct perf_event_context
*ctx
)
216 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
218 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
222 static inline u64
perf_clock(void)
224 return cpu_clock(raw_smp_processor_id());
228 * Update the record of the current time in a context.
230 static void update_context_time(struct perf_event_context
*ctx
)
232 u64 now
= perf_clock();
234 ctx
->time
+= now
- ctx
->timestamp
;
235 ctx
->timestamp
= now
;
239 * Update the total_time_enabled and total_time_running fields for a event.
241 static void update_event_times(struct perf_event
*event
)
243 struct perf_event_context
*ctx
= event
->ctx
;
246 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
247 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
253 run_end
= event
->tstamp_stopped
;
255 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
257 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
258 run_end
= event
->tstamp_stopped
;
262 event
->total_time_running
= run_end
- event
->tstamp_running
;
265 static struct list_head
*
266 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
268 if (event
->attr
.pinned
)
269 return &ctx
->pinned_groups
;
271 return &ctx
->flexible_groups
;
275 * Add a event from the lists for its context.
276 * Must be called with ctx->mutex and ctx->lock held.
279 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
281 struct perf_event
*group_leader
= event
->group_leader
;
284 * Depending on whether it is a standalone or sibling event,
285 * add it straight to the context's event list, or to the group
286 * leader's sibling list:
288 if (group_leader
== event
) {
289 struct list_head
*list
;
291 if (is_software_event(event
))
292 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
294 list
= ctx_group_list(event
, ctx
);
295 list_add_tail(&event
->group_entry
, list
);
297 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
298 !is_software_event(event
))
299 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
301 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
302 group_leader
->nr_siblings
++;
305 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
307 if (event
->attr
.inherit_stat
)
312 * Remove a event from the lists for its context.
313 * Must be called with ctx->mutex and ctx->lock held.
316 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
318 struct perf_event
*sibling
, *tmp
;
320 if (list_empty(&event
->group_entry
))
323 if (event
->attr
.inherit_stat
)
326 list_del_init(&event
->group_entry
);
327 list_del_rcu(&event
->event_entry
);
329 if (event
->group_leader
!= event
)
330 event
->group_leader
->nr_siblings
--;
332 update_event_times(event
);
335 * If event was in error state, then keep it
336 * that way, otherwise bogus counts will be
337 * returned on read(). The only way to get out
338 * of error state is by explicit re-enabling
341 if (event
->state
> PERF_EVENT_STATE_OFF
)
342 event
->state
= PERF_EVENT_STATE_OFF
;
345 * If this was a group event with sibling events then
346 * upgrade the siblings to singleton events by adding them
347 * to the context list directly:
349 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
350 struct list_head
*list
;
352 list
= ctx_group_list(event
, ctx
);
353 list_move_tail(&sibling
->group_entry
, list
);
354 sibling
->group_leader
= sibling
;
356 /* Inherit group flags from the previous leader */
357 sibling
->group_flags
= event
->group_flags
;
362 event_sched_out(struct perf_event
*event
,
363 struct perf_cpu_context
*cpuctx
,
364 struct perf_event_context
*ctx
)
366 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
369 event
->state
= PERF_EVENT_STATE_INACTIVE
;
370 if (event
->pending_disable
) {
371 event
->pending_disable
= 0;
372 event
->state
= PERF_EVENT_STATE_OFF
;
374 event
->tstamp_stopped
= ctx
->time
;
375 event
->pmu
->disable(event
);
378 if (!is_software_event(event
))
379 cpuctx
->active_oncpu
--;
381 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
382 cpuctx
->exclusive
= 0;
386 group_sched_out(struct perf_event
*group_event
,
387 struct perf_cpu_context
*cpuctx
,
388 struct perf_event_context
*ctx
)
390 struct perf_event
*event
;
392 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
395 event_sched_out(group_event
, cpuctx
, ctx
);
398 * Schedule out siblings (if any):
400 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
401 event_sched_out(event
, cpuctx
, ctx
);
403 if (group_event
->attr
.exclusive
)
404 cpuctx
->exclusive
= 0;
408 * Cross CPU call to remove a performance event
410 * We disable the event on the hardware level first. After that we
411 * remove it from the context list.
413 static void __perf_event_remove_from_context(void *info
)
415 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
416 struct perf_event
*event
= info
;
417 struct perf_event_context
*ctx
= event
->ctx
;
420 * If this is a task context, we need to check whether it is
421 * the current task context of this cpu. If not it has been
422 * scheduled out before the smp call arrived.
424 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
427 raw_spin_lock(&ctx
->lock
);
429 * Protect the list operation against NMI by disabling the
430 * events on a global level.
434 event_sched_out(event
, cpuctx
, ctx
);
436 list_del_event(event
, ctx
);
440 * Allow more per task events with respect to the
443 cpuctx
->max_pertask
=
444 min(perf_max_events
- ctx
->nr_events
,
445 perf_max_events
- perf_reserved_percpu
);
449 raw_spin_unlock(&ctx
->lock
);
454 * Remove the event from a task's (or a CPU's) list of events.
456 * Must be called with ctx->mutex held.
458 * CPU events are removed with a smp call. For task events we only
459 * call when the task is on a CPU.
461 * If event->ctx is a cloned context, callers must make sure that
462 * every task struct that event->ctx->task could possibly point to
463 * remains valid. This is OK when called from perf_release since
464 * that only calls us on the top-level context, which can't be a clone.
465 * When called from perf_event_exit_task, it's OK because the
466 * context has been detached from its task.
468 static void perf_event_remove_from_context(struct perf_event
*event
)
470 struct perf_event_context
*ctx
= event
->ctx
;
471 struct task_struct
*task
= ctx
->task
;
475 * Per cpu events are removed via an smp call and
476 * the removal is always successful.
478 smp_call_function_single(event
->cpu
,
479 __perf_event_remove_from_context
,
485 task_oncpu_function_call(task
, __perf_event_remove_from_context
,
488 raw_spin_lock_irq(&ctx
->lock
);
490 * If the context is active we need to retry the smp call.
492 if (ctx
->nr_active
&& !list_empty(&event
->group_entry
)) {
493 raw_spin_unlock_irq(&ctx
->lock
);
498 * The lock prevents that this context is scheduled in so we
499 * can remove the event safely, if the call above did not
502 if (!list_empty(&event
->group_entry
))
503 list_del_event(event
, ctx
);
504 raw_spin_unlock_irq(&ctx
->lock
);
508 * Update total_time_enabled and total_time_running for all events in a group.
510 static void update_group_times(struct perf_event
*leader
)
512 struct perf_event
*event
;
514 update_event_times(leader
);
515 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
516 update_event_times(event
);
520 * Cross CPU call to disable a performance event
522 static void __perf_event_disable(void *info
)
524 struct perf_event
*event
= info
;
525 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
526 struct perf_event_context
*ctx
= event
->ctx
;
529 * If this is a per-task event, need to check whether this
530 * event's task is the current task on this cpu.
532 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
535 raw_spin_lock(&ctx
->lock
);
538 * If the event is on, turn it off.
539 * If it is in error state, leave it in error state.
541 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
542 update_context_time(ctx
);
543 update_group_times(event
);
544 if (event
== event
->group_leader
)
545 group_sched_out(event
, cpuctx
, ctx
);
547 event_sched_out(event
, cpuctx
, ctx
);
548 event
->state
= PERF_EVENT_STATE_OFF
;
551 raw_spin_unlock(&ctx
->lock
);
557 * If event->ctx is a cloned context, callers must make sure that
558 * every task struct that event->ctx->task could possibly point to
559 * remains valid. This condition is satisifed when called through
560 * perf_event_for_each_child or perf_event_for_each because they
561 * hold the top-level event's child_mutex, so any descendant that
562 * goes to exit will block in sync_child_event.
563 * When called from perf_pending_event it's OK because event->ctx
564 * is the current context on this CPU and preemption is disabled,
565 * hence we can't get into perf_event_task_sched_out for this context.
567 void perf_event_disable(struct perf_event
*event
)
569 struct perf_event_context
*ctx
= event
->ctx
;
570 struct task_struct
*task
= ctx
->task
;
574 * Disable the event on the cpu that it's on
576 smp_call_function_single(event
->cpu
, __perf_event_disable
,
582 task_oncpu_function_call(task
, __perf_event_disable
, event
);
584 raw_spin_lock_irq(&ctx
->lock
);
586 * If the event is still active, we need to retry the cross-call.
588 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
589 raw_spin_unlock_irq(&ctx
->lock
);
594 * Since we have the lock this context can't be scheduled
595 * in, so we can change the state safely.
597 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
598 update_group_times(event
);
599 event
->state
= PERF_EVENT_STATE_OFF
;
602 raw_spin_unlock_irq(&ctx
->lock
);
606 event_sched_in(struct perf_event
*event
,
607 struct perf_cpu_context
*cpuctx
,
608 struct perf_event_context
*ctx
)
610 if (event
->state
<= PERF_EVENT_STATE_OFF
)
613 event
->state
= PERF_EVENT_STATE_ACTIVE
;
614 event
->oncpu
= smp_processor_id();
616 * The new state must be visible before we turn it on in the hardware:
620 if (event
->pmu
->enable(event
)) {
621 event
->state
= PERF_EVENT_STATE_INACTIVE
;
626 event
->tstamp_running
+= ctx
->time
- event
->tstamp_stopped
;
628 if (!is_software_event(event
))
629 cpuctx
->active_oncpu
++;
632 if (event
->attr
.exclusive
)
633 cpuctx
->exclusive
= 1;
639 group_sched_in(struct perf_event
*group_event
,
640 struct perf_cpu_context
*cpuctx
,
641 struct perf_event_context
*ctx
)
643 struct perf_event
*event
, *partial_group
;
646 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
649 ret
= hw_perf_group_sched_in(group_event
, cpuctx
, ctx
);
651 return ret
< 0 ? ret
: 0;
653 if (event_sched_in(group_event
, cpuctx
, ctx
))
657 * Schedule in siblings as one group (if any):
659 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
660 if (event_sched_in(event
, cpuctx
, ctx
)) {
661 partial_group
= event
;
670 * Groups can be scheduled in as one unit only, so undo any
671 * partial group before returning:
673 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
674 if (event
== partial_group
)
676 event_sched_out(event
, cpuctx
, ctx
);
678 event_sched_out(group_event
, cpuctx
, ctx
);
684 * Work out whether we can put this event group on the CPU now.
686 static int group_can_go_on(struct perf_event
*event
,
687 struct perf_cpu_context
*cpuctx
,
691 * Groups consisting entirely of software events can always go on.
693 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
696 * If an exclusive group is already on, no other hardware
699 if (cpuctx
->exclusive
)
702 * If this group is exclusive and there are already
703 * events on the CPU, it can't go on.
705 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
708 * Otherwise, try to add it if all previous groups were able
714 static void add_event_to_ctx(struct perf_event
*event
,
715 struct perf_event_context
*ctx
)
717 list_add_event(event
, ctx
);
718 event
->tstamp_enabled
= ctx
->time
;
719 event
->tstamp_running
= ctx
->time
;
720 event
->tstamp_stopped
= ctx
->time
;
724 * Cross CPU call to install and enable a performance event
726 * Must be called with ctx->mutex held
728 static void __perf_install_in_context(void *info
)
730 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
731 struct perf_event
*event
= info
;
732 struct perf_event_context
*ctx
= event
->ctx
;
733 struct perf_event
*leader
= event
->group_leader
;
737 * If this is a task context, we need to check whether it is
738 * the current task context of this cpu. If not it has been
739 * scheduled out before the smp call arrived.
740 * Or possibly this is the right context but it isn't
741 * on this cpu because it had no events.
743 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
744 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
746 cpuctx
->task_ctx
= ctx
;
749 raw_spin_lock(&ctx
->lock
);
751 update_context_time(ctx
);
754 * Protect the list operation against NMI by disabling the
755 * events on a global level. NOP for non NMI based events.
759 add_event_to_ctx(event
, ctx
);
761 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
765 * Don't put the event on if it is disabled or if
766 * it is in a group and the group isn't on.
768 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
769 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
773 * An exclusive event can't go on if there are already active
774 * hardware events, and no hardware event can go on if there
775 * is already an exclusive event on.
777 if (!group_can_go_on(event
, cpuctx
, 1))
780 err
= event_sched_in(event
, cpuctx
, ctx
);
784 * This event couldn't go on. If it is in a group
785 * then we have to pull the whole group off.
786 * If the event group is pinned then put it in error state.
789 group_sched_out(leader
, cpuctx
, ctx
);
790 if (leader
->attr
.pinned
) {
791 update_group_times(leader
);
792 leader
->state
= PERF_EVENT_STATE_ERROR
;
796 if (!err
&& !ctx
->task
&& cpuctx
->max_pertask
)
797 cpuctx
->max_pertask
--;
802 raw_spin_unlock(&ctx
->lock
);
806 * Attach a performance event to a context
808 * First we add the event to the list with the hardware enable bit
809 * in event->hw_config cleared.
811 * If the event is attached to a task which is on a CPU we use a smp
812 * call to enable it in the task context. The task might have been
813 * scheduled away, but we check this in the smp call again.
815 * Must be called with ctx->mutex held.
818 perf_install_in_context(struct perf_event_context
*ctx
,
819 struct perf_event
*event
,
822 struct task_struct
*task
= ctx
->task
;
826 * Per cpu events are installed via an smp call and
827 * the install is always successful.
829 smp_call_function_single(cpu
, __perf_install_in_context
,
835 task_oncpu_function_call(task
, __perf_install_in_context
,
838 raw_spin_lock_irq(&ctx
->lock
);
840 * we need to retry the smp call.
842 if (ctx
->is_active
&& list_empty(&event
->group_entry
)) {
843 raw_spin_unlock_irq(&ctx
->lock
);
848 * The lock prevents that this context is scheduled in so we
849 * can add the event safely, if it the call above did not
852 if (list_empty(&event
->group_entry
))
853 add_event_to_ctx(event
, ctx
);
854 raw_spin_unlock_irq(&ctx
->lock
);
858 * Put a event into inactive state and update time fields.
859 * Enabling the leader of a group effectively enables all
860 * the group members that aren't explicitly disabled, so we
861 * have to update their ->tstamp_enabled also.
862 * Note: this works for group members as well as group leaders
863 * since the non-leader members' sibling_lists will be empty.
865 static void __perf_event_mark_enabled(struct perf_event
*event
,
866 struct perf_event_context
*ctx
)
868 struct perf_event
*sub
;
870 event
->state
= PERF_EVENT_STATE_INACTIVE
;
871 event
->tstamp_enabled
= ctx
->time
- event
->total_time_enabled
;
872 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
)
873 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
874 sub
->tstamp_enabled
=
875 ctx
->time
- sub
->total_time_enabled
;
879 * Cross CPU call to enable a performance event
881 static void __perf_event_enable(void *info
)
883 struct perf_event
*event
= info
;
884 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
885 struct perf_event_context
*ctx
= event
->ctx
;
886 struct perf_event
*leader
= event
->group_leader
;
890 * If this is a per-task event, need to check whether this
891 * event's task is the current task on this cpu.
893 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
894 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
896 cpuctx
->task_ctx
= ctx
;
899 raw_spin_lock(&ctx
->lock
);
901 update_context_time(ctx
);
903 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
905 __perf_event_mark_enabled(event
, ctx
);
907 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
911 * If the event is in a group and isn't the group leader,
912 * then don't put it on unless the group is on.
914 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
917 if (!group_can_go_on(event
, cpuctx
, 1)) {
922 err
= group_sched_in(event
, cpuctx
, ctx
);
924 err
= event_sched_in(event
, cpuctx
, ctx
);
930 * If this event can't go on and it's part of a
931 * group, then the whole group has to come off.
934 group_sched_out(leader
, cpuctx
, ctx
);
935 if (leader
->attr
.pinned
) {
936 update_group_times(leader
);
937 leader
->state
= PERF_EVENT_STATE_ERROR
;
942 raw_spin_unlock(&ctx
->lock
);
948 * If event->ctx is a cloned context, callers must make sure that
949 * every task struct that event->ctx->task could possibly point to
950 * remains valid. This condition is satisfied when called through
951 * perf_event_for_each_child or perf_event_for_each as described
952 * for perf_event_disable.
954 void perf_event_enable(struct perf_event
*event
)
956 struct perf_event_context
*ctx
= event
->ctx
;
957 struct task_struct
*task
= ctx
->task
;
961 * Enable the event on the cpu that it's on
963 smp_call_function_single(event
->cpu
, __perf_event_enable
,
968 raw_spin_lock_irq(&ctx
->lock
);
969 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
973 * If the event is in error state, clear that first.
974 * That way, if we see the event in error state below, we
975 * know that it has gone back into error state, as distinct
976 * from the task having been scheduled away before the
977 * cross-call arrived.
979 if (event
->state
== PERF_EVENT_STATE_ERROR
)
980 event
->state
= PERF_EVENT_STATE_OFF
;
983 raw_spin_unlock_irq(&ctx
->lock
);
984 task_oncpu_function_call(task
, __perf_event_enable
, event
);
986 raw_spin_lock_irq(&ctx
->lock
);
989 * If the context is active and the event is still off,
990 * we need to retry the cross-call.
992 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
)
996 * Since we have the lock this context can't be scheduled
997 * in, so we can change the state safely.
999 if (event
->state
== PERF_EVENT_STATE_OFF
)
1000 __perf_event_mark_enabled(event
, ctx
);
1003 raw_spin_unlock_irq(&ctx
->lock
);
1006 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1009 * not supported on inherited events
1011 if (event
->attr
.inherit
)
1014 atomic_add(refresh
, &event
->event_limit
);
1015 perf_event_enable(event
);
1021 EVENT_FLEXIBLE
= 0x1,
1023 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
1026 static void ctx_sched_out(struct perf_event_context
*ctx
,
1027 struct perf_cpu_context
*cpuctx
,
1028 enum event_type_t event_type
)
1030 struct perf_event
*event
;
1032 raw_spin_lock(&ctx
->lock
);
1034 if (likely(!ctx
->nr_events
))
1036 update_context_time(ctx
);
1039 if (!ctx
->nr_active
)
1042 if (event_type
& EVENT_PINNED
)
1043 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1044 group_sched_out(event
, cpuctx
, ctx
);
1046 if (event_type
& EVENT_FLEXIBLE
)
1047 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1048 group_sched_out(event
, cpuctx
, ctx
);
1053 raw_spin_unlock(&ctx
->lock
);
1057 * Test whether two contexts are equivalent, i.e. whether they
1058 * have both been cloned from the same version of the same context
1059 * and they both have the same number of enabled events.
1060 * If the number of enabled events is the same, then the set
1061 * of enabled events should be the same, because these are both
1062 * inherited contexts, therefore we can't access individual events
1063 * in them directly with an fd; we can only enable/disable all
1064 * events via prctl, or enable/disable all events in a family
1065 * via ioctl, which will have the same effect on both contexts.
1067 static int context_equiv(struct perf_event_context
*ctx1
,
1068 struct perf_event_context
*ctx2
)
1070 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1071 && ctx1
->parent_gen
== ctx2
->parent_gen
1072 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1075 static void __perf_event_sync_stat(struct perf_event
*event
,
1076 struct perf_event
*next_event
)
1080 if (!event
->attr
.inherit_stat
)
1084 * Update the event value, we cannot use perf_event_read()
1085 * because we're in the middle of a context switch and have IRQs
1086 * disabled, which upsets smp_call_function_single(), however
1087 * we know the event must be on the current CPU, therefore we
1088 * don't need to use it.
1090 switch (event
->state
) {
1091 case PERF_EVENT_STATE_ACTIVE
:
1092 event
->pmu
->read(event
);
1095 case PERF_EVENT_STATE_INACTIVE
:
1096 update_event_times(event
);
1104 * In order to keep per-task stats reliable we need to flip the event
1105 * values when we flip the contexts.
1107 value
= atomic64_read(&next_event
->count
);
1108 value
= atomic64_xchg(&event
->count
, value
);
1109 atomic64_set(&next_event
->count
, value
);
1111 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1112 swap(event
->total_time_running
, next_event
->total_time_running
);
1115 * Since we swizzled the values, update the user visible data too.
1117 perf_event_update_userpage(event
);
1118 perf_event_update_userpage(next_event
);
1121 #define list_next_entry(pos, member) \
1122 list_entry(pos->member.next, typeof(*pos), member)
1124 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1125 struct perf_event_context
*next_ctx
)
1127 struct perf_event
*event
, *next_event
;
1132 update_context_time(ctx
);
1134 event
= list_first_entry(&ctx
->event_list
,
1135 struct perf_event
, event_entry
);
1137 next_event
= list_first_entry(&next_ctx
->event_list
,
1138 struct perf_event
, event_entry
);
1140 while (&event
->event_entry
!= &ctx
->event_list
&&
1141 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1143 __perf_event_sync_stat(event
, next_event
);
1145 event
= list_next_entry(event
, event_entry
);
1146 next_event
= list_next_entry(next_event
, event_entry
);
1151 * Called from scheduler to remove the events of the current task,
1152 * with interrupts disabled.
1154 * We stop each event and update the event value in event->count.
1156 * This does not protect us against NMI, but disable()
1157 * sets the disabled bit in the control field of event _before_
1158 * accessing the event control register. If a NMI hits, then it will
1159 * not restart the event.
1161 void perf_event_task_sched_out(struct task_struct
*task
,
1162 struct task_struct
*next
)
1164 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1165 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1166 struct perf_event_context
*next_ctx
;
1167 struct perf_event_context
*parent
;
1170 perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES
, 1, 1, NULL
, 0);
1172 if (likely(!ctx
|| !cpuctx
->task_ctx
))
1176 parent
= rcu_dereference(ctx
->parent_ctx
);
1177 next_ctx
= next
->perf_event_ctxp
;
1178 if (parent
&& next_ctx
&&
1179 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1181 * Looks like the two contexts are clones, so we might be
1182 * able to optimize the context switch. We lock both
1183 * contexts and check that they are clones under the
1184 * lock (including re-checking that neither has been
1185 * uncloned in the meantime). It doesn't matter which
1186 * order we take the locks because no other cpu could
1187 * be trying to lock both of these tasks.
1189 raw_spin_lock(&ctx
->lock
);
1190 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1191 if (context_equiv(ctx
, next_ctx
)) {
1193 * XXX do we need a memory barrier of sorts
1194 * wrt to rcu_dereference() of perf_event_ctxp
1196 task
->perf_event_ctxp
= next_ctx
;
1197 next
->perf_event_ctxp
= ctx
;
1199 next_ctx
->task
= task
;
1202 perf_event_sync_stat(ctx
, next_ctx
);
1204 raw_spin_unlock(&next_ctx
->lock
);
1205 raw_spin_unlock(&ctx
->lock
);
1210 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1211 cpuctx
->task_ctx
= NULL
;
1215 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1216 enum event_type_t event_type
)
1218 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1220 if (!cpuctx
->task_ctx
)
1223 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1226 ctx_sched_out(ctx
, cpuctx
, event_type
);
1227 cpuctx
->task_ctx
= NULL
;
1231 * Called with IRQs disabled
1233 static void __perf_event_task_sched_out(struct perf_event_context
*ctx
)
1235 task_ctx_sched_out(ctx
, EVENT_ALL
);
1239 * Called with IRQs disabled
1241 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1242 enum event_type_t event_type
)
1244 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1248 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1249 struct perf_cpu_context
*cpuctx
)
1251 struct perf_event
*event
;
1253 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1254 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1256 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1259 if (group_can_go_on(event
, cpuctx
, 1))
1260 group_sched_in(event
, cpuctx
, ctx
);
1263 * If this pinned group hasn't been scheduled,
1264 * put it in error state.
1266 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1267 update_group_times(event
);
1268 event
->state
= PERF_EVENT_STATE_ERROR
;
1274 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
1275 struct perf_cpu_context
*cpuctx
)
1277 struct perf_event
*event
;
1280 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1281 /* Ignore events in OFF or ERROR state */
1282 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1285 * Listen to the 'cpu' scheduling filter constraint
1288 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1291 if (group_can_go_on(event
, cpuctx
, can_add_hw
))
1292 if (group_sched_in(event
, cpuctx
, ctx
))
1298 ctx_sched_in(struct perf_event_context
*ctx
,
1299 struct perf_cpu_context
*cpuctx
,
1300 enum event_type_t event_type
)
1302 raw_spin_lock(&ctx
->lock
);
1304 if (likely(!ctx
->nr_events
))
1307 ctx
->timestamp
= perf_clock();
1312 * First go through the list and put on any pinned groups
1313 * in order to give them the best chance of going on.
1315 if (event_type
& EVENT_PINNED
)
1316 ctx_pinned_sched_in(ctx
, cpuctx
);
1318 /* Then walk through the lower prio flexible groups */
1319 if (event_type
& EVENT_FLEXIBLE
)
1320 ctx_flexible_sched_in(ctx
, cpuctx
);
1324 raw_spin_unlock(&ctx
->lock
);
1327 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
1328 enum event_type_t event_type
)
1330 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
1332 ctx_sched_in(ctx
, cpuctx
, event_type
);
1335 static void task_ctx_sched_in(struct task_struct
*task
,
1336 enum event_type_t event_type
)
1338 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1339 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1343 if (cpuctx
->task_ctx
== ctx
)
1345 ctx_sched_in(ctx
, cpuctx
, event_type
);
1346 cpuctx
->task_ctx
= ctx
;
1349 * Called from scheduler to add the events of the current task
1350 * with interrupts disabled.
1352 * We restore the event value and then enable it.
1354 * This does not protect us against NMI, but enable()
1355 * sets the enabled bit in the control field of event _before_
1356 * accessing the event control register. If a NMI hits, then it will
1357 * keep the event running.
1359 void perf_event_task_sched_in(struct task_struct
*task
)
1361 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1362 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1367 if (cpuctx
->task_ctx
== ctx
)
1373 * We want to keep the following priority order:
1374 * cpu pinned (that don't need to move), task pinned,
1375 * cpu flexible, task flexible.
1377 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1379 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
);
1380 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1381 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
);
1383 cpuctx
->task_ctx
= ctx
;
1388 #define MAX_INTERRUPTS (~0ULL)
1390 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1392 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1394 u64 frequency
= event
->attr
.sample_freq
;
1395 u64 sec
= NSEC_PER_SEC
;
1396 u64 divisor
, dividend
;
1398 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
1400 count_fls
= fls64(count
);
1401 nsec_fls
= fls64(nsec
);
1402 frequency_fls
= fls64(frequency
);
1406 * We got @count in @nsec, with a target of sample_freq HZ
1407 * the target period becomes:
1410 * period = -------------------
1411 * @nsec * sample_freq
1416 * Reduce accuracy by one bit such that @a and @b converge
1417 * to a similar magnitude.
1419 #define REDUCE_FLS(a, b) \
1421 if (a##_fls > b##_fls) { \
1431 * Reduce accuracy until either term fits in a u64, then proceed with
1432 * the other, so that finally we can do a u64/u64 division.
1434 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
1435 REDUCE_FLS(nsec
, frequency
);
1436 REDUCE_FLS(sec
, count
);
1439 if (count_fls
+ sec_fls
> 64) {
1440 divisor
= nsec
* frequency
;
1442 while (count_fls
+ sec_fls
> 64) {
1443 REDUCE_FLS(count
, sec
);
1447 dividend
= count
* sec
;
1449 dividend
= count
* sec
;
1451 while (nsec_fls
+ frequency_fls
> 64) {
1452 REDUCE_FLS(nsec
, frequency
);
1456 divisor
= nsec
* frequency
;
1459 return div64_u64(dividend
, divisor
);
1462 static void perf_event_stop(struct perf_event
*event
)
1464 if (!event
->pmu
->stop
)
1465 return event
->pmu
->disable(event
);
1467 return event
->pmu
->stop(event
);
1470 static int perf_event_start(struct perf_event
*event
)
1472 if (!event
->pmu
->start
)
1473 return event
->pmu
->enable(event
);
1475 return event
->pmu
->start(event
);
1478 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1480 struct hw_perf_event
*hwc
= &event
->hw
;
1481 u64 period
, sample_period
;
1484 period
= perf_calculate_period(event
, nsec
, count
);
1486 delta
= (s64
)(period
- hwc
->sample_period
);
1487 delta
= (delta
+ 7) / 8; /* low pass filter */
1489 sample_period
= hwc
->sample_period
+ delta
;
1494 hwc
->sample_period
= sample_period
;
1496 if (atomic64_read(&hwc
->period_left
) > 8*sample_period
) {
1498 perf_event_stop(event
);
1499 atomic64_set(&hwc
->period_left
, 0);
1500 perf_event_start(event
);
1505 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
)
1507 struct perf_event
*event
;
1508 struct hw_perf_event
*hwc
;
1509 u64 interrupts
, now
;
1512 raw_spin_lock(&ctx
->lock
);
1513 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
1514 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1517 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1522 interrupts
= hwc
->interrupts
;
1523 hwc
->interrupts
= 0;
1526 * unthrottle events on the tick
1528 if (interrupts
== MAX_INTERRUPTS
) {
1529 perf_log_throttle(event
, 1);
1531 event
->pmu
->unthrottle(event
);
1535 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
1539 event
->pmu
->read(event
);
1540 now
= atomic64_read(&event
->count
);
1541 delta
= now
- hwc
->freq_count_stamp
;
1542 hwc
->freq_count_stamp
= now
;
1545 perf_adjust_period(event
, TICK_NSEC
, delta
);
1548 raw_spin_unlock(&ctx
->lock
);
1552 * Round-robin a context's events:
1554 static void rotate_ctx(struct perf_event_context
*ctx
)
1556 raw_spin_lock(&ctx
->lock
);
1558 /* Rotate the first entry last of non-pinned groups */
1559 list_rotate_left(&ctx
->flexible_groups
);
1561 raw_spin_unlock(&ctx
->lock
);
1564 void perf_event_task_tick(struct task_struct
*curr
)
1566 struct perf_cpu_context
*cpuctx
;
1567 struct perf_event_context
*ctx
;
1570 if (!atomic_read(&nr_events
))
1573 cpuctx
= &__get_cpu_var(perf_cpu_context
);
1574 if (cpuctx
->ctx
.nr_events
&&
1575 cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
1578 ctx
= curr
->perf_event_ctxp
;
1579 if (ctx
&& ctx
->nr_events
&& ctx
->nr_events
!= ctx
->nr_active
)
1582 perf_ctx_adjust_freq(&cpuctx
->ctx
);
1584 perf_ctx_adjust_freq(ctx
);
1590 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1592 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
1594 rotate_ctx(&cpuctx
->ctx
);
1598 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1600 task_ctx_sched_in(curr
, EVENT_FLEXIBLE
);
1604 static int event_enable_on_exec(struct perf_event
*event
,
1605 struct perf_event_context
*ctx
)
1607 if (!event
->attr
.enable_on_exec
)
1610 event
->attr
.enable_on_exec
= 0;
1611 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1614 __perf_event_mark_enabled(event
, ctx
);
1620 * Enable all of a task's events that have been marked enable-on-exec.
1621 * This expects task == current.
1623 static void perf_event_enable_on_exec(struct task_struct
*task
)
1625 struct perf_event_context
*ctx
;
1626 struct perf_event
*event
;
1627 unsigned long flags
;
1631 local_irq_save(flags
);
1632 ctx
= task
->perf_event_ctxp
;
1633 if (!ctx
|| !ctx
->nr_events
)
1636 __perf_event_task_sched_out(ctx
);
1638 raw_spin_lock(&ctx
->lock
);
1640 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1641 ret
= event_enable_on_exec(event
, ctx
);
1646 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1647 ret
= event_enable_on_exec(event
, ctx
);
1653 * Unclone this context if we enabled any event.
1658 raw_spin_unlock(&ctx
->lock
);
1660 perf_event_task_sched_in(task
);
1662 local_irq_restore(flags
);
1666 * Cross CPU call to read the hardware event
1668 static void __perf_event_read(void *info
)
1670 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1671 struct perf_event
*event
= info
;
1672 struct perf_event_context
*ctx
= event
->ctx
;
1675 * If this is a task context, we need to check whether it is
1676 * the current task context of this cpu. If not it has been
1677 * scheduled out before the smp call arrived. In that case
1678 * event->count would have been updated to a recent sample
1679 * when the event was scheduled out.
1681 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1684 raw_spin_lock(&ctx
->lock
);
1685 update_context_time(ctx
);
1686 update_event_times(event
);
1687 raw_spin_unlock(&ctx
->lock
);
1689 event
->pmu
->read(event
);
1692 static u64
perf_event_read(struct perf_event
*event
)
1695 * If event is enabled and currently active on a CPU, update the
1696 * value in the event structure:
1698 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1699 smp_call_function_single(event
->oncpu
,
1700 __perf_event_read
, event
, 1);
1701 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1702 struct perf_event_context
*ctx
= event
->ctx
;
1703 unsigned long flags
;
1705 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1706 update_context_time(ctx
);
1707 update_event_times(event
);
1708 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1711 return atomic64_read(&event
->count
);
1715 * Initialize the perf_event context in a task_struct:
1718 __perf_event_init_context(struct perf_event_context
*ctx
,
1719 struct task_struct
*task
)
1721 raw_spin_lock_init(&ctx
->lock
);
1722 mutex_init(&ctx
->mutex
);
1723 INIT_LIST_HEAD(&ctx
->pinned_groups
);
1724 INIT_LIST_HEAD(&ctx
->flexible_groups
);
1725 INIT_LIST_HEAD(&ctx
->event_list
);
1726 atomic_set(&ctx
->refcount
, 1);
1730 static struct perf_event_context
*find_get_context(pid_t pid
, int cpu
)
1732 struct perf_event_context
*ctx
;
1733 struct perf_cpu_context
*cpuctx
;
1734 struct task_struct
*task
;
1735 unsigned long flags
;
1738 if (pid
== -1 && cpu
!= -1) {
1739 /* Must be root to operate on a CPU event: */
1740 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
1741 return ERR_PTR(-EACCES
);
1743 if (cpu
< 0 || cpu
>= nr_cpumask_bits
)
1744 return ERR_PTR(-EINVAL
);
1747 * We could be clever and allow to attach a event to an
1748 * offline CPU and activate it when the CPU comes up, but
1751 if (!cpu_online(cpu
))
1752 return ERR_PTR(-ENODEV
);
1754 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1765 task
= find_task_by_vpid(pid
);
1767 get_task_struct(task
);
1771 return ERR_PTR(-ESRCH
);
1774 * Can't attach events to a dying task.
1777 if (task
->flags
& PF_EXITING
)
1780 /* Reuse ptrace permission checks for now. */
1782 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
1786 ctx
= perf_lock_task_context(task
, &flags
);
1789 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1793 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
1797 __perf_event_init_context(ctx
, task
);
1799 if (cmpxchg(&task
->perf_event_ctxp
, NULL
, ctx
)) {
1801 * We raced with some other task; use
1802 * the context they set.
1807 get_task_struct(task
);
1810 put_task_struct(task
);
1814 put_task_struct(task
);
1815 return ERR_PTR(err
);
1818 static void perf_event_free_filter(struct perf_event
*event
);
1820 static void free_event_rcu(struct rcu_head
*head
)
1822 struct perf_event
*event
;
1824 event
= container_of(head
, struct perf_event
, rcu_head
);
1826 put_pid_ns(event
->ns
);
1827 perf_event_free_filter(event
);
1831 static void perf_pending_sync(struct perf_event
*event
);
1833 static void free_event(struct perf_event
*event
)
1835 perf_pending_sync(event
);
1837 if (!event
->parent
) {
1838 atomic_dec(&nr_events
);
1839 if (event
->attr
.mmap
)
1840 atomic_dec(&nr_mmap_events
);
1841 if (event
->attr
.comm
)
1842 atomic_dec(&nr_comm_events
);
1843 if (event
->attr
.task
)
1844 atomic_dec(&nr_task_events
);
1847 if (event
->output
) {
1848 fput(event
->output
->filp
);
1849 event
->output
= NULL
;
1853 event
->destroy(event
);
1855 put_ctx(event
->ctx
);
1856 call_rcu(&event
->rcu_head
, free_event_rcu
);
1859 int perf_event_release_kernel(struct perf_event
*event
)
1861 struct perf_event_context
*ctx
= event
->ctx
;
1863 WARN_ON_ONCE(ctx
->parent_ctx
);
1864 mutex_lock(&ctx
->mutex
);
1865 perf_event_remove_from_context(event
);
1866 mutex_unlock(&ctx
->mutex
);
1868 mutex_lock(&event
->owner
->perf_event_mutex
);
1869 list_del_init(&event
->owner_entry
);
1870 mutex_unlock(&event
->owner
->perf_event_mutex
);
1871 put_task_struct(event
->owner
);
1877 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
1880 * Called when the last reference to the file is gone.
1882 static int perf_release(struct inode
*inode
, struct file
*file
)
1884 struct perf_event
*event
= file
->private_data
;
1886 file
->private_data
= NULL
;
1888 return perf_event_release_kernel(event
);
1891 static int perf_event_read_size(struct perf_event
*event
)
1893 int entry
= sizeof(u64
); /* value */
1897 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1898 size
+= sizeof(u64
);
1900 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1901 size
+= sizeof(u64
);
1903 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1904 entry
+= sizeof(u64
);
1906 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1907 nr
+= event
->group_leader
->nr_siblings
;
1908 size
+= sizeof(u64
);
1916 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
1918 struct perf_event
*child
;
1924 mutex_lock(&event
->child_mutex
);
1925 total
+= perf_event_read(event
);
1926 *enabled
+= event
->total_time_enabled
+
1927 atomic64_read(&event
->child_total_time_enabled
);
1928 *running
+= event
->total_time_running
+
1929 atomic64_read(&event
->child_total_time_running
);
1931 list_for_each_entry(child
, &event
->child_list
, child_list
) {
1932 total
+= perf_event_read(child
);
1933 *enabled
+= child
->total_time_enabled
;
1934 *running
+= child
->total_time_running
;
1936 mutex_unlock(&event
->child_mutex
);
1940 EXPORT_SYMBOL_GPL(perf_event_read_value
);
1942 static int perf_event_read_group(struct perf_event
*event
,
1943 u64 read_format
, char __user
*buf
)
1945 struct perf_event
*leader
= event
->group_leader
, *sub
;
1946 int n
= 0, size
= 0, ret
= -EFAULT
;
1947 struct perf_event_context
*ctx
= leader
->ctx
;
1949 u64 count
, enabled
, running
;
1951 mutex_lock(&ctx
->mutex
);
1952 count
= perf_event_read_value(leader
, &enabled
, &running
);
1954 values
[n
++] = 1 + leader
->nr_siblings
;
1955 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1956 values
[n
++] = enabled
;
1957 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1958 values
[n
++] = running
;
1959 values
[n
++] = count
;
1960 if (read_format
& PERF_FORMAT_ID
)
1961 values
[n
++] = primary_event_id(leader
);
1963 size
= n
* sizeof(u64
);
1965 if (copy_to_user(buf
, values
, size
))
1970 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
1973 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
1974 if (read_format
& PERF_FORMAT_ID
)
1975 values
[n
++] = primary_event_id(sub
);
1977 size
= n
* sizeof(u64
);
1979 if (copy_to_user(buf
+ ret
, values
, size
)) {
1987 mutex_unlock(&ctx
->mutex
);
1992 static int perf_event_read_one(struct perf_event
*event
,
1993 u64 read_format
, char __user
*buf
)
1995 u64 enabled
, running
;
1999 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
2000 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2001 values
[n
++] = enabled
;
2002 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2003 values
[n
++] = running
;
2004 if (read_format
& PERF_FORMAT_ID
)
2005 values
[n
++] = primary_event_id(event
);
2007 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2010 return n
* sizeof(u64
);
2014 * Read the performance event - simple non blocking version for now
2017 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2019 u64 read_format
= event
->attr
.read_format
;
2023 * Return end-of-file for a read on a event that is in
2024 * error state (i.e. because it was pinned but it couldn't be
2025 * scheduled on to the CPU at some point).
2027 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2030 if (count
< perf_event_read_size(event
))
2033 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2034 if (read_format
& PERF_FORMAT_GROUP
)
2035 ret
= perf_event_read_group(event
, read_format
, buf
);
2037 ret
= perf_event_read_one(event
, read_format
, buf
);
2043 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2045 struct perf_event
*event
= file
->private_data
;
2047 return perf_read_hw(event
, buf
, count
);
2050 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2052 struct perf_event
*event
= file
->private_data
;
2053 struct perf_mmap_data
*data
;
2054 unsigned int events
= POLL_HUP
;
2057 data
= rcu_dereference(event
->data
);
2059 events
= atomic_xchg(&data
->poll
, 0);
2062 poll_wait(file
, &event
->waitq
, wait
);
2067 static void perf_event_reset(struct perf_event
*event
)
2069 (void)perf_event_read(event
);
2070 atomic64_set(&event
->count
, 0);
2071 perf_event_update_userpage(event
);
2075 * Holding the top-level event's child_mutex means that any
2076 * descendant process that has inherited this event will block
2077 * in sync_child_event if it goes to exit, thus satisfying the
2078 * task existence requirements of perf_event_enable/disable.
2080 static void perf_event_for_each_child(struct perf_event
*event
,
2081 void (*func
)(struct perf_event
*))
2083 struct perf_event
*child
;
2085 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2086 mutex_lock(&event
->child_mutex
);
2088 list_for_each_entry(child
, &event
->child_list
, child_list
)
2090 mutex_unlock(&event
->child_mutex
);
2093 static void perf_event_for_each(struct perf_event
*event
,
2094 void (*func
)(struct perf_event
*))
2096 struct perf_event_context
*ctx
= event
->ctx
;
2097 struct perf_event
*sibling
;
2099 WARN_ON_ONCE(ctx
->parent_ctx
);
2100 mutex_lock(&ctx
->mutex
);
2101 event
= event
->group_leader
;
2103 perf_event_for_each_child(event
, func
);
2105 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
2106 perf_event_for_each_child(event
, func
);
2107 mutex_unlock(&ctx
->mutex
);
2110 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
2112 struct perf_event_context
*ctx
= event
->ctx
;
2117 if (!event
->attr
.sample_period
)
2120 size
= copy_from_user(&value
, arg
, sizeof(value
));
2121 if (size
!= sizeof(value
))
2127 raw_spin_lock_irq(&ctx
->lock
);
2128 if (event
->attr
.freq
) {
2129 if (value
> sysctl_perf_event_sample_rate
) {
2134 event
->attr
.sample_freq
= value
;
2136 event
->attr
.sample_period
= value
;
2137 event
->hw
.sample_period
= value
;
2140 raw_spin_unlock_irq(&ctx
->lock
);
2145 static int perf_event_set_output(struct perf_event
*event
, int output_fd
);
2146 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
2148 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2150 struct perf_event
*event
= file
->private_data
;
2151 void (*func
)(struct perf_event
*);
2155 case PERF_EVENT_IOC_ENABLE
:
2156 func
= perf_event_enable
;
2158 case PERF_EVENT_IOC_DISABLE
:
2159 func
= perf_event_disable
;
2161 case PERF_EVENT_IOC_RESET
:
2162 func
= perf_event_reset
;
2165 case PERF_EVENT_IOC_REFRESH
:
2166 return perf_event_refresh(event
, arg
);
2168 case PERF_EVENT_IOC_PERIOD
:
2169 return perf_event_period(event
, (u64 __user
*)arg
);
2171 case PERF_EVENT_IOC_SET_OUTPUT
:
2172 return perf_event_set_output(event
, arg
);
2174 case PERF_EVENT_IOC_SET_FILTER
:
2175 return perf_event_set_filter(event
, (void __user
*)arg
);
2181 if (flags
& PERF_IOC_FLAG_GROUP
)
2182 perf_event_for_each(event
, func
);
2184 perf_event_for_each_child(event
, func
);
2189 int perf_event_task_enable(void)
2191 struct perf_event
*event
;
2193 mutex_lock(¤t
->perf_event_mutex
);
2194 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2195 perf_event_for_each_child(event
, perf_event_enable
);
2196 mutex_unlock(¤t
->perf_event_mutex
);
2201 int perf_event_task_disable(void)
2203 struct perf_event
*event
;
2205 mutex_lock(¤t
->perf_event_mutex
);
2206 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2207 perf_event_for_each_child(event
, perf_event_disable
);
2208 mutex_unlock(¤t
->perf_event_mutex
);
2213 #ifndef PERF_EVENT_INDEX_OFFSET
2214 # define PERF_EVENT_INDEX_OFFSET 0
2217 static int perf_event_index(struct perf_event
*event
)
2219 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2222 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
2226 * Callers need to ensure there can be no nesting of this function, otherwise
2227 * the seqlock logic goes bad. We can not serialize this because the arch
2228 * code calls this from NMI context.
2230 void perf_event_update_userpage(struct perf_event
*event
)
2232 struct perf_event_mmap_page
*userpg
;
2233 struct perf_mmap_data
*data
;
2236 data
= rcu_dereference(event
->data
);
2240 userpg
= data
->user_page
;
2243 * Disable preemption so as to not let the corresponding user-space
2244 * spin too long if we get preempted.
2249 userpg
->index
= perf_event_index(event
);
2250 userpg
->offset
= atomic64_read(&event
->count
);
2251 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2252 userpg
->offset
-= atomic64_read(&event
->hw
.prev_count
);
2254 userpg
->time_enabled
= event
->total_time_enabled
+
2255 atomic64_read(&event
->child_total_time_enabled
);
2257 userpg
->time_running
= event
->total_time_running
+
2258 atomic64_read(&event
->child_total_time_running
);
2267 static unsigned long perf_data_size(struct perf_mmap_data
*data
)
2269 return data
->nr_pages
<< (PAGE_SHIFT
+ data
->data_order
);
2272 #ifndef CONFIG_PERF_USE_VMALLOC
2275 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
2278 static struct page
*
2279 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2281 if (pgoff
> data
->nr_pages
)
2285 return virt_to_page(data
->user_page
);
2287 return virt_to_page(data
->data_pages
[pgoff
- 1]);
2290 static struct perf_mmap_data
*
2291 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2293 struct perf_mmap_data
*data
;
2297 WARN_ON(atomic_read(&event
->mmap_count
));
2299 size
= sizeof(struct perf_mmap_data
);
2300 size
+= nr_pages
* sizeof(void *);
2302 data
= kzalloc(size
, GFP_KERNEL
);
2306 data
->user_page
= (void *)get_zeroed_page(GFP_KERNEL
);
2307 if (!data
->user_page
)
2308 goto fail_user_page
;
2310 for (i
= 0; i
< nr_pages
; i
++) {
2311 data
->data_pages
[i
] = (void *)get_zeroed_page(GFP_KERNEL
);
2312 if (!data
->data_pages
[i
])
2313 goto fail_data_pages
;
2316 data
->data_order
= 0;
2317 data
->nr_pages
= nr_pages
;
2322 for (i
--; i
>= 0; i
--)
2323 free_page((unsigned long)data
->data_pages
[i
]);
2325 free_page((unsigned long)data
->user_page
);
2334 static void perf_mmap_free_page(unsigned long addr
)
2336 struct page
*page
= virt_to_page((void *)addr
);
2338 page
->mapping
= NULL
;
2342 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2346 perf_mmap_free_page((unsigned long)data
->user_page
);
2347 for (i
= 0; i
< data
->nr_pages
; i
++)
2348 perf_mmap_free_page((unsigned long)data
->data_pages
[i
]);
2355 * Back perf_mmap() with vmalloc memory.
2357 * Required for architectures that have d-cache aliasing issues.
2360 static struct page
*
2361 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2363 if (pgoff
> (1UL << data
->data_order
))
2366 return vmalloc_to_page((void *)data
->user_page
+ pgoff
* PAGE_SIZE
);
2369 static void perf_mmap_unmark_page(void *addr
)
2371 struct page
*page
= vmalloc_to_page(addr
);
2373 page
->mapping
= NULL
;
2376 static void perf_mmap_data_free_work(struct work_struct
*work
)
2378 struct perf_mmap_data
*data
;
2382 data
= container_of(work
, struct perf_mmap_data
, work
);
2383 nr
= 1 << data
->data_order
;
2385 base
= data
->user_page
;
2386 for (i
= 0; i
< nr
+ 1; i
++)
2387 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
2393 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2395 schedule_work(&data
->work
);
2398 static struct perf_mmap_data
*
2399 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2401 struct perf_mmap_data
*data
;
2405 WARN_ON(atomic_read(&event
->mmap_count
));
2407 size
= sizeof(struct perf_mmap_data
);
2408 size
+= sizeof(void *);
2410 data
= kzalloc(size
, GFP_KERNEL
);
2414 INIT_WORK(&data
->work
, perf_mmap_data_free_work
);
2416 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
2420 data
->user_page
= all_buf
;
2421 data
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
2422 data
->data_order
= ilog2(nr_pages
);
2436 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
2438 struct perf_event
*event
= vma
->vm_file
->private_data
;
2439 struct perf_mmap_data
*data
;
2440 int ret
= VM_FAULT_SIGBUS
;
2442 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
2443 if (vmf
->pgoff
== 0)
2449 data
= rcu_dereference(event
->data
);
2453 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
2456 vmf
->page
= perf_mmap_to_page(data
, vmf
->pgoff
);
2460 get_page(vmf
->page
);
2461 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
2462 vmf
->page
->index
= vmf
->pgoff
;
2472 perf_mmap_data_init(struct perf_event
*event
, struct perf_mmap_data
*data
)
2474 long max_size
= perf_data_size(data
);
2476 atomic_set(&data
->lock
, -1);
2478 if (event
->attr
.watermark
) {
2479 data
->watermark
= min_t(long, max_size
,
2480 event
->attr
.wakeup_watermark
);
2483 if (!data
->watermark
)
2484 data
->watermark
= max_size
/ 2;
2487 rcu_assign_pointer(event
->data
, data
);
2490 static void perf_mmap_data_free_rcu(struct rcu_head
*rcu_head
)
2492 struct perf_mmap_data
*data
;
2494 data
= container_of(rcu_head
, struct perf_mmap_data
, rcu_head
);
2495 perf_mmap_data_free(data
);
2498 static void perf_mmap_data_release(struct perf_event
*event
)
2500 struct perf_mmap_data
*data
= event
->data
;
2502 WARN_ON(atomic_read(&event
->mmap_count
));
2504 rcu_assign_pointer(event
->data
, NULL
);
2505 call_rcu(&data
->rcu_head
, perf_mmap_data_free_rcu
);
2508 static void perf_mmap_open(struct vm_area_struct
*vma
)
2510 struct perf_event
*event
= vma
->vm_file
->private_data
;
2512 atomic_inc(&event
->mmap_count
);
2515 static void perf_mmap_close(struct vm_area_struct
*vma
)
2517 struct perf_event
*event
= vma
->vm_file
->private_data
;
2519 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2520 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
2521 unsigned long size
= perf_data_size(event
->data
);
2522 struct user_struct
*user
= current_user();
2524 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
2525 vma
->vm_mm
->locked_vm
-= event
->data
->nr_locked
;
2526 perf_mmap_data_release(event
);
2527 mutex_unlock(&event
->mmap_mutex
);
2531 static const struct vm_operations_struct perf_mmap_vmops
= {
2532 .open
= perf_mmap_open
,
2533 .close
= perf_mmap_close
,
2534 .fault
= perf_mmap_fault
,
2535 .page_mkwrite
= perf_mmap_fault
,
2538 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
2540 struct perf_event
*event
= file
->private_data
;
2541 unsigned long user_locked
, user_lock_limit
;
2542 struct user_struct
*user
= current_user();
2543 unsigned long locked
, lock_limit
;
2544 struct perf_mmap_data
*data
;
2545 unsigned long vma_size
;
2546 unsigned long nr_pages
;
2547 long user_extra
, extra
;
2550 if (!(vma
->vm_flags
& VM_SHARED
))
2553 vma_size
= vma
->vm_end
- vma
->vm_start
;
2554 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
2557 * If we have data pages ensure they're a power-of-two number, so we
2558 * can do bitmasks instead of modulo.
2560 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
2563 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
2566 if (vma
->vm_pgoff
!= 0)
2569 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2570 mutex_lock(&event
->mmap_mutex
);
2571 if (event
->output
) {
2576 if (atomic_inc_not_zero(&event
->mmap_count
)) {
2577 if (nr_pages
!= event
->data
->nr_pages
)
2582 user_extra
= nr_pages
+ 1;
2583 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
2586 * Increase the limit linearly with more CPUs:
2588 user_lock_limit
*= num_online_cpus();
2590 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
2593 if (user_locked
> user_lock_limit
)
2594 extra
= user_locked
- user_lock_limit
;
2596 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
2597 lock_limit
>>= PAGE_SHIFT
;
2598 locked
= vma
->vm_mm
->locked_vm
+ extra
;
2600 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
2601 !capable(CAP_IPC_LOCK
)) {
2606 WARN_ON(event
->data
);
2608 data
= perf_mmap_data_alloc(event
, nr_pages
);
2614 perf_mmap_data_init(event
, data
);
2616 atomic_set(&event
->mmap_count
, 1);
2617 atomic_long_add(user_extra
, &user
->locked_vm
);
2618 vma
->vm_mm
->locked_vm
+= extra
;
2619 event
->data
->nr_locked
= extra
;
2620 if (vma
->vm_flags
& VM_WRITE
)
2621 event
->data
->writable
= 1;
2624 mutex_unlock(&event
->mmap_mutex
);
2626 vma
->vm_flags
|= VM_RESERVED
;
2627 vma
->vm_ops
= &perf_mmap_vmops
;
2632 static int perf_fasync(int fd
, struct file
*filp
, int on
)
2634 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
2635 struct perf_event
*event
= filp
->private_data
;
2638 mutex_lock(&inode
->i_mutex
);
2639 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
2640 mutex_unlock(&inode
->i_mutex
);
2648 static const struct file_operations perf_fops
= {
2649 .llseek
= no_llseek
,
2650 .release
= perf_release
,
2653 .unlocked_ioctl
= perf_ioctl
,
2654 .compat_ioctl
= perf_ioctl
,
2656 .fasync
= perf_fasync
,
2662 * If there's data, ensure we set the poll() state and publish everything
2663 * to user-space before waking everybody up.
2666 void perf_event_wakeup(struct perf_event
*event
)
2668 wake_up_all(&event
->waitq
);
2670 if (event
->pending_kill
) {
2671 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
2672 event
->pending_kill
= 0;
2679 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
2681 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
2682 * single linked list and use cmpxchg() to add entries lockless.
2685 static void perf_pending_event(struct perf_pending_entry
*entry
)
2687 struct perf_event
*event
= container_of(entry
,
2688 struct perf_event
, pending
);
2690 if (event
->pending_disable
) {
2691 event
->pending_disable
= 0;
2692 __perf_event_disable(event
);
2695 if (event
->pending_wakeup
) {
2696 event
->pending_wakeup
= 0;
2697 perf_event_wakeup(event
);
2701 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
2703 static DEFINE_PER_CPU(struct perf_pending_entry
*, perf_pending_head
) = {
2707 static void perf_pending_queue(struct perf_pending_entry
*entry
,
2708 void (*func
)(struct perf_pending_entry
*))
2710 struct perf_pending_entry
**head
;
2712 if (cmpxchg(&entry
->next
, NULL
, PENDING_TAIL
) != NULL
)
2717 head
= &get_cpu_var(perf_pending_head
);
2720 entry
->next
= *head
;
2721 } while (cmpxchg(head
, entry
->next
, entry
) != entry
->next
);
2723 set_perf_event_pending();
2725 put_cpu_var(perf_pending_head
);
2728 static int __perf_pending_run(void)
2730 struct perf_pending_entry
*list
;
2733 list
= xchg(&__get_cpu_var(perf_pending_head
), PENDING_TAIL
);
2734 while (list
!= PENDING_TAIL
) {
2735 void (*func
)(struct perf_pending_entry
*);
2736 struct perf_pending_entry
*entry
= list
;
2743 * Ensure we observe the unqueue before we issue the wakeup,
2744 * so that we won't be waiting forever.
2745 * -- see perf_not_pending().
2756 static inline int perf_not_pending(struct perf_event
*event
)
2759 * If we flush on whatever cpu we run, there is a chance we don't
2763 __perf_pending_run();
2767 * Ensure we see the proper queue state before going to sleep
2768 * so that we do not miss the wakeup. -- see perf_pending_handle()
2771 return event
->pending
.next
== NULL
;
2774 static void perf_pending_sync(struct perf_event
*event
)
2776 wait_event(event
->waitq
, perf_not_pending(event
));
2779 void perf_event_do_pending(void)
2781 __perf_pending_run();
2785 * Callchain support -- arch specific
2788 __weak
struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2794 void perf_arch_fetch_caller_regs(struct pt_regs
*regs
, unsigned long ip
, int skip
)
2802 static bool perf_output_space(struct perf_mmap_data
*data
, unsigned long tail
,
2803 unsigned long offset
, unsigned long head
)
2807 if (!data
->writable
)
2810 mask
= perf_data_size(data
) - 1;
2812 offset
= (offset
- tail
) & mask
;
2813 head
= (head
- tail
) & mask
;
2815 if ((int)(head
- offset
) < 0)
2821 static void perf_output_wakeup(struct perf_output_handle
*handle
)
2823 atomic_set(&handle
->data
->poll
, POLL_IN
);
2826 handle
->event
->pending_wakeup
= 1;
2827 perf_pending_queue(&handle
->event
->pending
,
2828 perf_pending_event
);
2830 perf_event_wakeup(handle
->event
);
2834 * Curious locking construct.
2836 * We need to ensure a later event_id doesn't publish a head when a former
2837 * event_id isn't done writing. However since we need to deal with NMIs we
2838 * cannot fully serialize things.
2840 * What we do is serialize between CPUs so we only have to deal with NMI
2841 * nesting on a single CPU.
2843 * We only publish the head (and generate a wakeup) when the outer-most
2844 * event_id completes.
2846 static void perf_output_lock(struct perf_output_handle
*handle
)
2848 struct perf_mmap_data
*data
= handle
->data
;
2849 int cur
, cpu
= get_cpu();
2854 cur
= atomic_cmpxchg(&data
->lock
, -1, cpu
);
2866 static void perf_output_unlock(struct perf_output_handle
*handle
)
2868 struct perf_mmap_data
*data
= handle
->data
;
2872 data
->done_head
= data
->head
;
2874 if (!handle
->locked
)
2879 * The xchg implies a full barrier that ensures all writes are done
2880 * before we publish the new head, matched by a rmb() in userspace when
2881 * reading this position.
2883 while ((head
= atomic_long_xchg(&data
->done_head
, 0)))
2884 data
->user_page
->data_head
= head
;
2887 * NMI can happen here, which means we can miss a done_head update.
2890 cpu
= atomic_xchg(&data
->lock
, -1);
2891 WARN_ON_ONCE(cpu
!= smp_processor_id());
2894 * Therefore we have to validate we did not indeed do so.
2896 if (unlikely(atomic_long_read(&data
->done_head
))) {
2898 * Since we had it locked, we can lock it again.
2900 while (atomic_cmpxchg(&data
->lock
, -1, cpu
) != -1)
2906 if (atomic_xchg(&data
->wakeup
, 0))
2907 perf_output_wakeup(handle
);
2912 void perf_output_copy(struct perf_output_handle
*handle
,
2913 const void *buf
, unsigned int len
)
2915 unsigned int pages_mask
;
2916 unsigned long offset
;
2920 offset
= handle
->offset
;
2921 pages_mask
= handle
->data
->nr_pages
- 1;
2922 pages
= handle
->data
->data_pages
;
2925 unsigned long page_offset
;
2926 unsigned long page_size
;
2929 nr
= (offset
>> PAGE_SHIFT
) & pages_mask
;
2930 page_size
= 1UL << (handle
->data
->data_order
+ PAGE_SHIFT
);
2931 page_offset
= offset
& (page_size
- 1);
2932 size
= min_t(unsigned int, page_size
- page_offset
, len
);
2934 memcpy(pages
[nr
] + page_offset
, buf
, size
);
2941 handle
->offset
= offset
;
2944 * Check we didn't copy past our reservation window, taking the
2945 * possible unsigned int wrap into account.
2947 WARN_ON_ONCE(((long)(handle
->head
- handle
->offset
)) < 0);
2950 int perf_output_begin(struct perf_output_handle
*handle
,
2951 struct perf_event
*event
, unsigned int size
,
2952 int nmi
, int sample
)
2954 struct perf_event
*output_event
;
2955 struct perf_mmap_data
*data
;
2956 unsigned long tail
, offset
, head
;
2959 struct perf_event_header header
;
2966 * For inherited events we send all the output towards the parent.
2969 event
= event
->parent
;
2971 output_event
= rcu_dereference(event
->output
);
2973 event
= output_event
;
2975 data
= rcu_dereference(event
->data
);
2979 handle
->data
= data
;
2980 handle
->event
= event
;
2982 handle
->sample
= sample
;
2984 if (!data
->nr_pages
)
2987 have_lost
= atomic_read(&data
->lost
);
2989 size
+= sizeof(lost_event
);
2991 perf_output_lock(handle
);
2995 * Userspace could choose to issue a mb() before updating the
2996 * tail pointer. So that all reads will be completed before the
2999 tail
= ACCESS_ONCE(data
->user_page
->data_tail
);
3001 offset
= head
= atomic_long_read(&data
->head
);
3003 if (unlikely(!perf_output_space(data
, tail
, offset
, head
)))
3005 } while (atomic_long_cmpxchg(&data
->head
, offset
, head
) != offset
);
3007 handle
->offset
= offset
;
3008 handle
->head
= head
;
3010 if (head
- tail
> data
->watermark
)
3011 atomic_set(&data
->wakeup
, 1);
3014 lost_event
.header
.type
= PERF_RECORD_LOST
;
3015 lost_event
.header
.misc
= 0;
3016 lost_event
.header
.size
= sizeof(lost_event
);
3017 lost_event
.id
= event
->id
;
3018 lost_event
.lost
= atomic_xchg(&data
->lost
, 0);
3020 perf_output_put(handle
, lost_event
);
3026 atomic_inc(&data
->lost
);
3027 perf_output_unlock(handle
);
3034 void perf_output_end(struct perf_output_handle
*handle
)
3036 struct perf_event
*event
= handle
->event
;
3037 struct perf_mmap_data
*data
= handle
->data
;
3039 int wakeup_events
= event
->attr
.wakeup_events
;
3041 if (handle
->sample
&& wakeup_events
) {
3042 int events
= atomic_inc_return(&data
->events
);
3043 if (events
>= wakeup_events
) {
3044 atomic_sub(wakeup_events
, &data
->events
);
3045 atomic_set(&data
->wakeup
, 1);
3049 perf_output_unlock(handle
);
3053 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
3056 * only top level events have the pid namespace they were created in
3059 event
= event
->parent
;
3061 return task_tgid_nr_ns(p
, event
->ns
);
3064 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
3067 * only top level events have the pid namespace they were created in
3070 event
= event
->parent
;
3072 return task_pid_nr_ns(p
, event
->ns
);
3075 static void perf_output_read_one(struct perf_output_handle
*handle
,
3076 struct perf_event
*event
)
3078 u64 read_format
= event
->attr
.read_format
;
3082 values
[n
++] = atomic64_read(&event
->count
);
3083 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3084 values
[n
++] = event
->total_time_enabled
+
3085 atomic64_read(&event
->child_total_time_enabled
);
3087 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3088 values
[n
++] = event
->total_time_running
+
3089 atomic64_read(&event
->child_total_time_running
);
3091 if (read_format
& PERF_FORMAT_ID
)
3092 values
[n
++] = primary_event_id(event
);
3094 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3098 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3100 static void perf_output_read_group(struct perf_output_handle
*handle
,
3101 struct perf_event
*event
)
3103 struct perf_event
*leader
= event
->group_leader
, *sub
;
3104 u64 read_format
= event
->attr
.read_format
;
3108 values
[n
++] = 1 + leader
->nr_siblings
;
3110 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3111 values
[n
++] = leader
->total_time_enabled
;
3113 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3114 values
[n
++] = leader
->total_time_running
;
3116 if (leader
!= event
)
3117 leader
->pmu
->read(leader
);
3119 values
[n
++] = atomic64_read(&leader
->count
);
3120 if (read_format
& PERF_FORMAT_ID
)
3121 values
[n
++] = primary_event_id(leader
);
3123 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3125 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3129 sub
->pmu
->read(sub
);
3131 values
[n
++] = atomic64_read(&sub
->count
);
3132 if (read_format
& PERF_FORMAT_ID
)
3133 values
[n
++] = primary_event_id(sub
);
3135 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3139 static void perf_output_read(struct perf_output_handle
*handle
,
3140 struct perf_event
*event
)
3142 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3143 perf_output_read_group(handle
, event
);
3145 perf_output_read_one(handle
, event
);
3148 void perf_output_sample(struct perf_output_handle
*handle
,
3149 struct perf_event_header
*header
,
3150 struct perf_sample_data
*data
,
3151 struct perf_event
*event
)
3153 u64 sample_type
= data
->type
;
3155 perf_output_put(handle
, *header
);
3157 if (sample_type
& PERF_SAMPLE_IP
)
3158 perf_output_put(handle
, data
->ip
);
3160 if (sample_type
& PERF_SAMPLE_TID
)
3161 perf_output_put(handle
, data
->tid_entry
);
3163 if (sample_type
& PERF_SAMPLE_TIME
)
3164 perf_output_put(handle
, data
->time
);
3166 if (sample_type
& PERF_SAMPLE_ADDR
)
3167 perf_output_put(handle
, data
->addr
);
3169 if (sample_type
& PERF_SAMPLE_ID
)
3170 perf_output_put(handle
, data
->id
);
3172 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3173 perf_output_put(handle
, data
->stream_id
);
3175 if (sample_type
& PERF_SAMPLE_CPU
)
3176 perf_output_put(handle
, data
->cpu_entry
);
3178 if (sample_type
& PERF_SAMPLE_PERIOD
)
3179 perf_output_put(handle
, data
->period
);
3181 if (sample_type
& PERF_SAMPLE_READ
)
3182 perf_output_read(handle
, event
);
3184 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3185 if (data
->callchain
) {
3188 if (data
->callchain
)
3189 size
+= data
->callchain
->nr
;
3191 size
*= sizeof(u64
);
3193 perf_output_copy(handle
, data
->callchain
, size
);
3196 perf_output_put(handle
, nr
);
3200 if (sample_type
& PERF_SAMPLE_RAW
) {
3202 perf_output_put(handle
, data
->raw
->size
);
3203 perf_output_copy(handle
, data
->raw
->data
,
3210 .size
= sizeof(u32
),
3213 perf_output_put(handle
, raw
);
3218 void perf_prepare_sample(struct perf_event_header
*header
,
3219 struct perf_sample_data
*data
,
3220 struct perf_event
*event
,
3221 struct pt_regs
*regs
)
3223 u64 sample_type
= event
->attr
.sample_type
;
3225 data
->type
= sample_type
;
3227 header
->type
= PERF_RECORD_SAMPLE
;
3228 header
->size
= sizeof(*header
);
3231 header
->misc
|= perf_misc_flags(regs
);
3233 if (sample_type
& PERF_SAMPLE_IP
) {
3234 data
->ip
= perf_instruction_pointer(regs
);
3236 header
->size
+= sizeof(data
->ip
);
3239 if (sample_type
& PERF_SAMPLE_TID
) {
3240 /* namespace issues */
3241 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3242 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3244 header
->size
+= sizeof(data
->tid_entry
);
3247 if (sample_type
& PERF_SAMPLE_TIME
) {
3248 data
->time
= perf_clock();
3250 header
->size
+= sizeof(data
->time
);
3253 if (sample_type
& PERF_SAMPLE_ADDR
)
3254 header
->size
+= sizeof(data
->addr
);
3256 if (sample_type
& PERF_SAMPLE_ID
) {
3257 data
->id
= primary_event_id(event
);
3259 header
->size
+= sizeof(data
->id
);
3262 if (sample_type
& PERF_SAMPLE_STREAM_ID
) {
3263 data
->stream_id
= event
->id
;
3265 header
->size
+= sizeof(data
->stream_id
);
3268 if (sample_type
& PERF_SAMPLE_CPU
) {
3269 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3270 data
->cpu_entry
.reserved
= 0;
3272 header
->size
+= sizeof(data
->cpu_entry
);
3275 if (sample_type
& PERF_SAMPLE_PERIOD
)
3276 header
->size
+= sizeof(data
->period
);
3278 if (sample_type
& PERF_SAMPLE_READ
)
3279 header
->size
+= perf_event_read_size(event
);
3281 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3284 data
->callchain
= perf_callchain(regs
);
3286 if (data
->callchain
)
3287 size
+= data
->callchain
->nr
;
3289 header
->size
+= size
* sizeof(u64
);
3292 if (sample_type
& PERF_SAMPLE_RAW
) {
3293 int size
= sizeof(u32
);
3296 size
+= data
->raw
->size
;
3298 size
+= sizeof(u32
);
3300 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3301 header
->size
+= size
;
3305 static void perf_event_output(struct perf_event
*event
, int nmi
,
3306 struct perf_sample_data
*data
,
3307 struct pt_regs
*regs
)
3309 struct perf_output_handle handle
;
3310 struct perf_event_header header
;
3312 perf_prepare_sample(&header
, data
, event
, regs
);
3314 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
3317 perf_output_sample(&handle
, &header
, data
, event
);
3319 perf_output_end(&handle
);
3326 struct perf_read_event
{
3327 struct perf_event_header header
;
3334 perf_event_read_event(struct perf_event
*event
,
3335 struct task_struct
*task
)
3337 struct perf_output_handle handle
;
3338 struct perf_read_event read_event
= {
3340 .type
= PERF_RECORD_READ
,
3342 .size
= sizeof(read_event
) + perf_event_read_size(event
),
3344 .pid
= perf_event_pid(event
, task
),
3345 .tid
= perf_event_tid(event
, task
),
3349 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
3353 perf_output_put(&handle
, read_event
);
3354 perf_output_read(&handle
, event
);
3356 perf_output_end(&handle
);
3360 * task tracking -- fork/exit
3362 * enabled by: attr.comm | attr.mmap | attr.task
3365 struct perf_task_event
{
3366 struct task_struct
*task
;
3367 struct perf_event_context
*task_ctx
;
3370 struct perf_event_header header
;
3380 static void perf_event_task_output(struct perf_event
*event
,
3381 struct perf_task_event
*task_event
)
3383 struct perf_output_handle handle
;
3384 struct task_struct
*task
= task_event
->task
;
3385 unsigned long flags
;
3389 * If this CPU attempts to acquire an rq lock held by a CPU spinning
3390 * in perf_output_lock() from interrupt context, it's game over.
3392 local_irq_save(flags
);
3394 size
= task_event
->event_id
.header
.size
;
3395 ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3398 local_irq_restore(flags
);
3402 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
3403 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
3405 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
3406 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
3408 perf_output_put(&handle
, task_event
->event_id
);
3410 perf_output_end(&handle
);
3411 local_irq_restore(flags
);
3414 static int perf_event_task_match(struct perf_event
*event
)
3416 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3419 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3422 if (event
->attr
.comm
|| event
->attr
.mmap
|| event
->attr
.task
)
3428 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
3429 struct perf_task_event
*task_event
)
3431 struct perf_event
*event
;
3433 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3434 if (perf_event_task_match(event
))
3435 perf_event_task_output(event
, task_event
);
3439 static void perf_event_task_event(struct perf_task_event
*task_event
)
3441 struct perf_cpu_context
*cpuctx
;
3442 struct perf_event_context
*ctx
= task_event
->task_ctx
;
3445 cpuctx
= &get_cpu_var(perf_cpu_context
);
3446 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
3448 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3450 perf_event_task_ctx(ctx
, task_event
);
3451 put_cpu_var(perf_cpu_context
);
3455 static void perf_event_task(struct task_struct
*task
,
3456 struct perf_event_context
*task_ctx
,
3459 struct perf_task_event task_event
;
3461 if (!atomic_read(&nr_comm_events
) &&
3462 !atomic_read(&nr_mmap_events
) &&
3463 !atomic_read(&nr_task_events
))
3466 task_event
= (struct perf_task_event
){
3468 .task_ctx
= task_ctx
,
3471 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
3473 .size
= sizeof(task_event
.event_id
),
3479 .time
= perf_clock(),
3483 perf_event_task_event(&task_event
);
3486 void perf_event_fork(struct task_struct
*task
)
3488 perf_event_task(task
, NULL
, 1);
3495 struct perf_comm_event
{
3496 struct task_struct
*task
;
3501 struct perf_event_header header
;
3508 static void perf_event_comm_output(struct perf_event
*event
,
3509 struct perf_comm_event
*comm_event
)
3511 struct perf_output_handle handle
;
3512 int size
= comm_event
->event_id
.header
.size
;
3513 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3518 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
3519 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
3521 perf_output_put(&handle
, comm_event
->event_id
);
3522 perf_output_copy(&handle
, comm_event
->comm
,
3523 comm_event
->comm_size
);
3524 perf_output_end(&handle
);
3527 static int perf_event_comm_match(struct perf_event
*event
)
3529 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3532 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3535 if (event
->attr
.comm
)
3541 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
3542 struct perf_comm_event
*comm_event
)
3544 struct perf_event
*event
;
3546 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3547 if (perf_event_comm_match(event
))
3548 perf_event_comm_output(event
, comm_event
);
3552 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
3554 struct perf_cpu_context
*cpuctx
;
3555 struct perf_event_context
*ctx
;
3557 char comm
[TASK_COMM_LEN
];
3559 memset(comm
, 0, sizeof(comm
));
3560 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
3561 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
3563 comm_event
->comm
= comm
;
3564 comm_event
->comm_size
= size
;
3566 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
3569 cpuctx
= &get_cpu_var(perf_cpu_context
);
3570 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
3571 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3573 perf_event_comm_ctx(ctx
, comm_event
);
3574 put_cpu_var(perf_cpu_context
);
3578 void perf_event_comm(struct task_struct
*task
)
3580 struct perf_comm_event comm_event
;
3582 if (task
->perf_event_ctxp
)
3583 perf_event_enable_on_exec(task
);
3585 if (!atomic_read(&nr_comm_events
))
3588 comm_event
= (struct perf_comm_event
){
3594 .type
= PERF_RECORD_COMM
,
3603 perf_event_comm_event(&comm_event
);
3610 struct perf_mmap_event
{
3611 struct vm_area_struct
*vma
;
3613 const char *file_name
;
3617 struct perf_event_header header
;
3627 static void perf_event_mmap_output(struct perf_event
*event
,
3628 struct perf_mmap_event
*mmap_event
)
3630 struct perf_output_handle handle
;
3631 int size
= mmap_event
->event_id
.header
.size
;
3632 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3637 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
3638 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
3640 perf_output_put(&handle
, mmap_event
->event_id
);
3641 perf_output_copy(&handle
, mmap_event
->file_name
,
3642 mmap_event
->file_size
);
3643 perf_output_end(&handle
);
3646 static int perf_event_mmap_match(struct perf_event
*event
,
3647 struct perf_mmap_event
*mmap_event
)
3649 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3652 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3655 if (event
->attr
.mmap
)
3661 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
3662 struct perf_mmap_event
*mmap_event
)
3664 struct perf_event
*event
;
3666 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3667 if (perf_event_mmap_match(event
, mmap_event
))
3668 perf_event_mmap_output(event
, mmap_event
);
3672 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
3674 struct perf_cpu_context
*cpuctx
;
3675 struct perf_event_context
*ctx
;
3676 struct vm_area_struct
*vma
= mmap_event
->vma
;
3677 struct file
*file
= vma
->vm_file
;
3683 memset(tmp
, 0, sizeof(tmp
));
3687 * d_path works from the end of the buffer backwards, so we
3688 * need to add enough zero bytes after the string to handle
3689 * the 64bit alignment we do later.
3691 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
3693 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
3696 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
3698 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
3702 if (arch_vma_name(mmap_event
->vma
)) {
3703 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
3709 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
3713 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
3718 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
3720 mmap_event
->file_name
= name
;
3721 mmap_event
->file_size
= size
;
3723 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
3726 cpuctx
= &get_cpu_var(perf_cpu_context
);
3727 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
);
3728 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3730 perf_event_mmap_ctx(ctx
, mmap_event
);
3731 put_cpu_var(perf_cpu_context
);
3737 void __perf_event_mmap(struct vm_area_struct
*vma
)
3739 struct perf_mmap_event mmap_event
;
3741 if (!atomic_read(&nr_mmap_events
))
3744 mmap_event
= (struct perf_mmap_event
){
3750 .type
= PERF_RECORD_MMAP
,
3756 .start
= vma
->vm_start
,
3757 .len
= vma
->vm_end
- vma
->vm_start
,
3758 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
3762 perf_event_mmap_event(&mmap_event
);
3766 * IRQ throttle logging
3769 static void perf_log_throttle(struct perf_event
*event
, int enable
)
3771 struct perf_output_handle handle
;
3775 struct perf_event_header header
;
3779 } throttle_event
= {
3781 .type
= PERF_RECORD_THROTTLE
,
3783 .size
= sizeof(throttle_event
),
3785 .time
= perf_clock(),
3786 .id
= primary_event_id(event
),
3787 .stream_id
= event
->id
,
3791 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
3793 ret
= perf_output_begin(&handle
, event
, sizeof(throttle_event
), 1, 0);
3797 perf_output_put(&handle
, throttle_event
);
3798 perf_output_end(&handle
);
3802 * Generic event overflow handling, sampling.
3805 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
3806 int throttle
, struct perf_sample_data
*data
,
3807 struct pt_regs
*regs
)
3809 int events
= atomic_read(&event
->event_limit
);
3810 struct hw_perf_event
*hwc
= &event
->hw
;
3813 throttle
= (throttle
&& event
->pmu
->unthrottle
!= NULL
);
3818 if (hwc
->interrupts
!= MAX_INTERRUPTS
) {
3820 if (HZ
* hwc
->interrupts
>
3821 (u64
)sysctl_perf_event_sample_rate
) {
3822 hwc
->interrupts
= MAX_INTERRUPTS
;
3823 perf_log_throttle(event
, 0);
3828 * Keep re-disabling events even though on the previous
3829 * pass we disabled it - just in case we raced with a
3830 * sched-in and the event got enabled again:
3836 if (event
->attr
.freq
) {
3837 u64 now
= perf_clock();
3838 s64 delta
= now
- hwc
->freq_time_stamp
;
3840 hwc
->freq_time_stamp
= now
;
3842 if (delta
> 0 && delta
< 2*TICK_NSEC
)
3843 perf_adjust_period(event
, delta
, hwc
->last_period
);
3847 * XXX event_limit might not quite work as expected on inherited
3851 event
->pending_kill
= POLL_IN
;
3852 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
3854 event
->pending_kill
= POLL_HUP
;
3856 event
->pending_disable
= 1;
3857 perf_pending_queue(&event
->pending
,
3858 perf_pending_event
);
3860 perf_event_disable(event
);
3863 if (event
->overflow_handler
)
3864 event
->overflow_handler(event
, nmi
, data
, regs
);
3866 perf_event_output(event
, nmi
, data
, regs
);
3871 int perf_event_overflow(struct perf_event
*event
, int nmi
,
3872 struct perf_sample_data
*data
,
3873 struct pt_regs
*regs
)
3875 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
3879 * Generic software event infrastructure
3883 * We directly increment event->count and keep a second value in
3884 * event->hw.period_left to count intervals. This period event
3885 * is kept in the range [-sample_period, 0] so that we can use the
3889 static u64
perf_swevent_set_period(struct perf_event
*event
)
3891 struct hw_perf_event
*hwc
= &event
->hw
;
3892 u64 period
= hwc
->last_period
;
3896 hwc
->last_period
= hwc
->sample_period
;
3899 old
= val
= atomic64_read(&hwc
->period_left
);
3903 nr
= div64_u64(period
+ val
, period
);
3904 offset
= nr
* period
;
3906 if (atomic64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
3912 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
3913 int nmi
, struct perf_sample_data
*data
,
3914 struct pt_regs
*regs
)
3916 struct hw_perf_event
*hwc
= &event
->hw
;
3919 data
->period
= event
->hw
.last_period
;
3921 overflow
= perf_swevent_set_period(event
);
3923 if (hwc
->interrupts
== MAX_INTERRUPTS
)
3926 for (; overflow
; overflow
--) {
3927 if (__perf_event_overflow(event
, nmi
, throttle
,
3930 * We inhibit the overflow from happening when
3931 * hwc->interrupts == MAX_INTERRUPTS.
3939 static void perf_swevent_unthrottle(struct perf_event
*event
)
3942 * Nothing to do, we already reset hwc->interrupts.
3946 static void perf_swevent_add(struct perf_event
*event
, u64 nr
,
3947 int nmi
, struct perf_sample_data
*data
,
3948 struct pt_regs
*regs
)
3950 struct hw_perf_event
*hwc
= &event
->hw
;
3952 atomic64_add(nr
, &event
->count
);
3957 if (!hwc
->sample_period
)
3960 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
3961 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
3963 if (atomic64_add_negative(nr
, &hwc
->period_left
))
3966 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
3969 static int perf_swevent_is_counting(struct perf_event
*event
)
3972 * The event is active, we're good!
3974 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3978 * The event is off/error, not counting.
3980 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
)
3984 * The event is inactive, if the context is active
3985 * we're part of a group that didn't make it on the 'pmu',
3988 if (event
->ctx
->is_active
)
3992 * We're inactive and the context is too, this means the
3993 * task is scheduled out, we're counting events that happen
3994 * to us, like migration events.
3999 static int perf_tp_event_match(struct perf_event
*event
,
4000 struct perf_sample_data
*data
);
4002 static int perf_exclude_event(struct perf_event
*event
,
4003 struct pt_regs
*regs
)
4006 if (event
->attr
.exclude_user
&& user_mode(regs
))
4009 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4016 static int perf_swevent_match(struct perf_event
*event
,
4017 enum perf_type_id type
,
4019 struct perf_sample_data
*data
,
4020 struct pt_regs
*regs
)
4022 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
4025 if (!perf_swevent_is_counting(event
))
4028 if (event
->attr
.type
!= type
)
4031 if (event
->attr
.config
!= event_id
)
4034 if (perf_exclude_event(event
, regs
))
4037 if (event
->attr
.type
== PERF_TYPE_TRACEPOINT
&&
4038 !perf_tp_event_match(event
, data
))
4044 static void perf_swevent_ctx_event(struct perf_event_context
*ctx
,
4045 enum perf_type_id type
,
4046 u32 event_id
, u64 nr
, int nmi
,
4047 struct perf_sample_data
*data
,
4048 struct pt_regs
*regs
)
4050 struct perf_event
*event
;
4052 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4053 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4054 perf_swevent_add(event
, nr
, nmi
, data
, regs
);
4058 int perf_swevent_get_recursion_context(void)
4060 struct perf_cpu_context
*cpuctx
= &get_cpu_var(perf_cpu_context
);
4067 else if (in_softirq())
4072 if (cpuctx
->recursion
[rctx
]) {
4073 put_cpu_var(perf_cpu_context
);
4077 cpuctx
->recursion
[rctx
]++;
4082 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4084 void perf_swevent_put_recursion_context(int rctx
)
4086 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
4088 cpuctx
->recursion
[rctx
]--;
4089 put_cpu_var(perf_cpu_context
);
4091 EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context
);
4093 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4095 struct perf_sample_data
*data
,
4096 struct pt_regs
*regs
)
4098 struct perf_cpu_context
*cpuctx
;
4099 struct perf_event_context
*ctx
;
4101 cpuctx
= &__get_cpu_var(perf_cpu_context
);
4103 perf_swevent_ctx_event(&cpuctx
->ctx
, type
, event_id
,
4104 nr
, nmi
, data
, regs
);
4106 * doesn't really matter which of the child contexts the
4107 * events ends up in.
4109 ctx
= rcu_dereference(current
->perf_event_ctxp
);
4111 perf_swevent_ctx_event(ctx
, type
, event_id
, nr
, nmi
, data
, regs
);
4115 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
4116 struct pt_regs
*regs
, u64 addr
)
4118 struct perf_sample_data data
;
4121 rctx
= perf_swevent_get_recursion_context();
4125 perf_sample_data_init(&data
, addr
);
4127 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
4129 perf_swevent_put_recursion_context(rctx
);
4132 static void perf_swevent_read(struct perf_event
*event
)
4136 static int perf_swevent_enable(struct perf_event
*event
)
4138 struct hw_perf_event
*hwc
= &event
->hw
;
4140 if (hwc
->sample_period
) {
4141 hwc
->last_period
= hwc
->sample_period
;
4142 perf_swevent_set_period(event
);
4147 static void perf_swevent_disable(struct perf_event
*event
)
4151 static const struct pmu perf_ops_generic
= {
4152 .enable
= perf_swevent_enable
,
4153 .disable
= perf_swevent_disable
,
4154 .read
= perf_swevent_read
,
4155 .unthrottle
= perf_swevent_unthrottle
,
4159 * hrtimer based swevent callback
4162 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
4164 enum hrtimer_restart ret
= HRTIMER_RESTART
;
4165 struct perf_sample_data data
;
4166 struct pt_regs
*regs
;
4167 struct perf_event
*event
;
4170 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
4171 event
->pmu
->read(event
);
4173 perf_sample_data_init(&data
, 0);
4174 data
.period
= event
->hw
.last_period
;
4175 regs
= get_irq_regs();
4177 * In case we exclude kernel IPs or are somehow not in interrupt
4178 * context, provide the next best thing, the user IP.
4180 if ((event
->attr
.exclude_kernel
|| !regs
) &&
4181 !event
->attr
.exclude_user
)
4182 regs
= task_pt_regs(current
);
4185 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
4186 if (perf_event_overflow(event
, 0, &data
, regs
))
4187 ret
= HRTIMER_NORESTART
;
4190 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
4191 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
4196 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
4198 struct hw_perf_event
*hwc
= &event
->hw
;
4200 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
4201 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
4202 if (hwc
->sample_period
) {
4205 if (hwc
->remaining
) {
4206 if (hwc
->remaining
< 0)
4209 period
= hwc
->remaining
;
4212 period
= max_t(u64
, 10000, hwc
->sample_period
);
4214 __hrtimer_start_range_ns(&hwc
->hrtimer
,
4215 ns_to_ktime(period
), 0,
4216 HRTIMER_MODE_REL
, 0);
4220 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
4222 struct hw_perf_event
*hwc
= &event
->hw
;
4224 if (hwc
->sample_period
) {
4225 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
4226 hwc
->remaining
= ktime_to_ns(remaining
);
4228 hrtimer_cancel(&hwc
->hrtimer
);
4233 * Software event: cpu wall time clock
4236 static void cpu_clock_perf_event_update(struct perf_event
*event
)
4238 int cpu
= raw_smp_processor_id();
4242 now
= cpu_clock(cpu
);
4243 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4244 atomic64_add(now
- prev
, &event
->count
);
4247 static int cpu_clock_perf_event_enable(struct perf_event
*event
)
4249 struct hw_perf_event
*hwc
= &event
->hw
;
4250 int cpu
= raw_smp_processor_id();
4252 atomic64_set(&hwc
->prev_count
, cpu_clock(cpu
));
4253 perf_swevent_start_hrtimer(event
);
4258 static void cpu_clock_perf_event_disable(struct perf_event
*event
)
4260 perf_swevent_cancel_hrtimer(event
);
4261 cpu_clock_perf_event_update(event
);
4264 static void cpu_clock_perf_event_read(struct perf_event
*event
)
4266 cpu_clock_perf_event_update(event
);
4269 static const struct pmu perf_ops_cpu_clock
= {
4270 .enable
= cpu_clock_perf_event_enable
,
4271 .disable
= cpu_clock_perf_event_disable
,
4272 .read
= cpu_clock_perf_event_read
,
4276 * Software event: task time clock
4279 static void task_clock_perf_event_update(struct perf_event
*event
, u64 now
)
4284 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4286 atomic64_add(delta
, &event
->count
);
4289 static int task_clock_perf_event_enable(struct perf_event
*event
)
4291 struct hw_perf_event
*hwc
= &event
->hw
;
4294 now
= event
->ctx
->time
;
4296 atomic64_set(&hwc
->prev_count
, now
);
4298 perf_swevent_start_hrtimer(event
);
4303 static void task_clock_perf_event_disable(struct perf_event
*event
)
4305 perf_swevent_cancel_hrtimer(event
);
4306 task_clock_perf_event_update(event
, event
->ctx
->time
);
4310 static void task_clock_perf_event_read(struct perf_event
*event
)
4315 update_context_time(event
->ctx
);
4316 time
= event
->ctx
->time
;
4318 u64 now
= perf_clock();
4319 u64 delta
= now
- event
->ctx
->timestamp
;
4320 time
= event
->ctx
->time
+ delta
;
4323 task_clock_perf_event_update(event
, time
);
4326 static const struct pmu perf_ops_task_clock
= {
4327 .enable
= task_clock_perf_event_enable
,
4328 .disable
= task_clock_perf_event_disable
,
4329 .read
= task_clock_perf_event_read
,
4332 #ifdef CONFIG_EVENT_TRACING
4334 void perf_tp_event(int event_id
, u64 addr
, u64 count
, void *record
,
4335 int entry_size
, struct pt_regs
*regs
)
4337 struct perf_sample_data data
;
4338 struct perf_raw_record raw
= {
4343 perf_sample_data_init(&data
, addr
);
4346 /* Trace events already protected against recursion */
4347 do_perf_sw_event(PERF_TYPE_TRACEPOINT
, event_id
, count
, 1,
4350 EXPORT_SYMBOL_GPL(perf_tp_event
);
4352 static int perf_tp_event_match(struct perf_event
*event
,
4353 struct perf_sample_data
*data
)
4355 void *record
= data
->raw
->data
;
4357 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
4362 static void tp_perf_event_destroy(struct perf_event
*event
)
4364 perf_trace_disable(event
->attr
.config
);
4367 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4370 * Raw tracepoint data is a severe data leak, only allow root to
4373 if ((event
->attr
.sample_type
& PERF_SAMPLE_RAW
) &&
4374 perf_paranoid_tracepoint_raw() &&
4375 !capable(CAP_SYS_ADMIN
))
4376 return ERR_PTR(-EPERM
);
4378 if (perf_trace_enable(event
->attr
.config
))
4381 event
->destroy
= tp_perf_event_destroy
;
4383 return &perf_ops_generic
;
4386 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4391 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4394 filter_str
= strndup_user(arg
, PAGE_SIZE
);
4395 if (IS_ERR(filter_str
))
4396 return PTR_ERR(filter_str
);
4398 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
4404 static void perf_event_free_filter(struct perf_event
*event
)
4406 ftrace_profile_free_filter(event
);
4411 static int perf_tp_event_match(struct perf_event
*event
,
4412 struct perf_sample_data
*data
)
4417 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4422 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4427 static void perf_event_free_filter(struct perf_event
*event
)
4431 #endif /* CONFIG_EVENT_TRACING */
4433 #ifdef CONFIG_HAVE_HW_BREAKPOINT
4434 static void bp_perf_event_destroy(struct perf_event
*event
)
4436 release_bp_slot(event
);
4439 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4443 err
= register_perf_hw_breakpoint(bp
);
4445 return ERR_PTR(err
);
4447 bp
->destroy
= bp_perf_event_destroy
;
4449 return &perf_ops_bp
;
4452 void perf_bp_event(struct perf_event
*bp
, void *data
)
4454 struct perf_sample_data sample
;
4455 struct pt_regs
*regs
= data
;
4457 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
4459 if (!perf_exclude_event(bp
, regs
))
4460 perf_swevent_add(bp
, 1, 1, &sample
, regs
);
4463 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4468 void perf_bp_event(struct perf_event
*bp
, void *regs
)
4473 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4475 static void sw_perf_event_destroy(struct perf_event
*event
)
4477 u64 event_id
= event
->attr
.config
;
4479 WARN_ON(event
->parent
);
4481 atomic_dec(&perf_swevent_enabled
[event_id
]);
4484 static const struct pmu
*sw_perf_event_init(struct perf_event
*event
)
4486 const struct pmu
*pmu
= NULL
;
4487 u64 event_id
= event
->attr
.config
;
4490 * Software events (currently) can't in general distinguish
4491 * between user, kernel and hypervisor events.
4492 * However, context switches and cpu migrations are considered
4493 * to be kernel events, and page faults are never hypervisor
4497 case PERF_COUNT_SW_CPU_CLOCK
:
4498 pmu
= &perf_ops_cpu_clock
;
4501 case PERF_COUNT_SW_TASK_CLOCK
:
4503 * If the user instantiates this as a per-cpu event,
4504 * use the cpu_clock event instead.
4506 if (event
->ctx
->task
)
4507 pmu
= &perf_ops_task_clock
;
4509 pmu
= &perf_ops_cpu_clock
;
4512 case PERF_COUNT_SW_PAGE_FAULTS
:
4513 case PERF_COUNT_SW_PAGE_FAULTS_MIN
:
4514 case PERF_COUNT_SW_PAGE_FAULTS_MAJ
:
4515 case PERF_COUNT_SW_CONTEXT_SWITCHES
:
4516 case PERF_COUNT_SW_CPU_MIGRATIONS
:
4517 case PERF_COUNT_SW_ALIGNMENT_FAULTS
:
4518 case PERF_COUNT_SW_EMULATION_FAULTS
:
4519 if (!event
->parent
) {
4520 atomic_inc(&perf_swevent_enabled
[event_id
]);
4521 event
->destroy
= sw_perf_event_destroy
;
4523 pmu
= &perf_ops_generic
;
4531 * Allocate and initialize a event structure
4533 static struct perf_event
*
4534 perf_event_alloc(struct perf_event_attr
*attr
,
4536 struct perf_event_context
*ctx
,
4537 struct perf_event
*group_leader
,
4538 struct perf_event
*parent_event
,
4539 perf_overflow_handler_t overflow_handler
,
4542 const struct pmu
*pmu
;
4543 struct perf_event
*event
;
4544 struct hw_perf_event
*hwc
;
4547 event
= kzalloc(sizeof(*event
), gfpflags
);
4549 return ERR_PTR(-ENOMEM
);
4552 * Single events are their own group leaders, with an
4553 * empty sibling list:
4556 group_leader
= event
;
4558 mutex_init(&event
->child_mutex
);
4559 INIT_LIST_HEAD(&event
->child_list
);
4561 INIT_LIST_HEAD(&event
->group_entry
);
4562 INIT_LIST_HEAD(&event
->event_entry
);
4563 INIT_LIST_HEAD(&event
->sibling_list
);
4564 init_waitqueue_head(&event
->waitq
);
4566 mutex_init(&event
->mmap_mutex
);
4569 event
->attr
= *attr
;
4570 event
->group_leader
= group_leader
;
4575 event
->parent
= parent_event
;
4577 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
4578 event
->id
= atomic64_inc_return(&perf_event_id
);
4580 event
->state
= PERF_EVENT_STATE_INACTIVE
;
4582 if (!overflow_handler
&& parent_event
)
4583 overflow_handler
= parent_event
->overflow_handler
;
4585 event
->overflow_handler
= overflow_handler
;
4588 event
->state
= PERF_EVENT_STATE_OFF
;
4593 hwc
->sample_period
= attr
->sample_period
;
4594 if (attr
->freq
&& attr
->sample_freq
)
4595 hwc
->sample_period
= 1;
4596 hwc
->last_period
= hwc
->sample_period
;
4598 atomic64_set(&hwc
->period_left
, hwc
->sample_period
);
4601 * we currently do not support PERF_FORMAT_GROUP on inherited events
4603 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
4606 switch (attr
->type
) {
4608 case PERF_TYPE_HARDWARE
:
4609 case PERF_TYPE_HW_CACHE
:
4610 pmu
= hw_perf_event_init(event
);
4613 case PERF_TYPE_SOFTWARE
:
4614 pmu
= sw_perf_event_init(event
);
4617 case PERF_TYPE_TRACEPOINT
:
4618 pmu
= tp_perf_event_init(event
);
4621 case PERF_TYPE_BREAKPOINT
:
4622 pmu
= bp_perf_event_init(event
);
4633 else if (IS_ERR(pmu
))
4638 put_pid_ns(event
->ns
);
4640 return ERR_PTR(err
);
4645 if (!event
->parent
) {
4646 atomic_inc(&nr_events
);
4647 if (event
->attr
.mmap
)
4648 atomic_inc(&nr_mmap_events
);
4649 if (event
->attr
.comm
)
4650 atomic_inc(&nr_comm_events
);
4651 if (event
->attr
.task
)
4652 atomic_inc(&nr_task_events
);
4658 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
4659 struct perf_event_attr
*attr
)
4664 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
4668 * zero the full structure, so that a short copy will be nice.
4670 memset(attr
, 0, sizeof(*attr
));
4672 ret
= get_user(size
, &uattr
->size
);
4676 if (size
> PAGE_SIZE
) /* silly large */
4679 if (!size
) /* abi compat */
4680 size
= PERF_ATTR_SIZE_VER0
;
4682 if (size
< PERF_ATTR_SIZE_VER0
)
4686 * If we're handed a bigger struct than we know of,
4687 * ensure all the unknown bits are 0 - i.e. new
4688 * user-space does not rely on any kernel feature
4689 * extensions we dont know about yet.
4691 if (size
> sizeof(*attr
)) {
4692 unsigned char __user
*addr
;
4693 unsigned char __user
*end
;
4696 addr
= (void __user
*)uattr
+ sizeof(*attr
);
4697 end
= (void __user
*)uattr
+ size
;
4699 for (; addr
< end
; addr
++) {
4700 ret
= get_user(val
, addr
);
4706 size
= sizeof(*attr
);
4709 ret
= copy_from_user(attr
, uattr
, size
);
4714 * If the type exists, the corresponding creation will verify
4717 if (attr
->type
>= PERF_TYPE_MAX
)
4720 if (attr
->__reserved_1
)
4723 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
4726 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
4733 put_user(sizeof(*attr
), &uattr
->size
);
4738 static int perf_event_set_output(struct perf_event
*event
, int output_fd
)
4740 struct perf_event
*output_event
= NULL
;
4741 struct file
*output_file
= NULL
;
4742 struct perf_event
*old_output
;
4743 int fput_needed
= 0;
4749 output_file
= fget_light(output_fd
, &fput_needed
);
4753 if (output_file
->f_op
!= &perf_fops
)
4756 output_event
= output_file
->private_data
;
4758 /* Don't chain output fds */
4759 if (output_event
->output
)
4762 /* Don't set an output fd when we already have an output channel */
4766 atomic_long_inc(&output_file
->f_count
);
4769 mutex_lock(&event
->mmap_mutex
);
4770 old_output
= event
->output
;
4771 rcu_assign_pointer(event
->output
, output_event
);
4772 mutex_unlock(&event
->mmap_mutex
);
4776 * we need to make sure no existing perf_output_*()
4777 * is still referencing this event.
4780 fput(old_output
->filp
);
4785 fput_light(output_file
, fput_needed
);
4790 * sys_perf_event_open - open a performance event, associate it to a task/cpu
4792 * @attr_uptr: event_id type attributes for monitoring/sampling
4795 * @group_fd: group leader event fd
4797 SYSCALL_DEFINE5(perf_event_open
,
4798 struct perf_event_attr __user
*, attr_uptr
,
4799 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
4801 struct perf_event
*event
, *group_leader
;
4802 struct perf_event_attr attr
;
4803 struct perf_event_context
*ctx
;
4804 struct file
*event_file
= NULL
;
4805 struct file
*group_file
= NULL
;
4806 int fput_needed
= 0;
4807 int fput_needed2
= 0;
4810 /* for future expandability... */
4811 if (flags
& ~(PERF_FLAG_FD_NO_GROUP
| PERF_FLAG_FD_OUTPUT
))
4814 err
= perf_copy_attr(attr_uptr
, &attr
);
4818 if (!attr
.exclude_kernel
) {
4819 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
4824 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
4829 * Get the target context (task or percpu):
4831 ctx
= find_get_context(pid
, cpu
);
4833 return PTR_ERR(ctx
);
4836 * Look up the group leader (we will attach this event to it):
4838 group_leader
= NULL
;
4839 if (group_fd
!= -1 && !(flags
& PERF_FLAG_FD_NO_GROUP
)) {
4841 group_file
= fget_light(group_fd
, &fput_needed
);
4843 goto err_put_context
;
4844 if (group_file
->f_op
!= &perf_fops
)
4845 goto err_put_context
;
4847 group_leader
= group_file
->private_data
;
4849 * Do not allow a recursive hierarchy (this new sibling
4850 * becoming part of another group-sibling):
4852 if (group_leader
->group_leader
!= group_leader
)
4853 goto err_put_context
;
4855 * Do not allow to attach to a group in a different
4856 * task or CPU context:
4858 if (group_leader
->ctx
!= ctx
)
4859 goto err_put_context
;
4861 * Only a group leader can be exclusive or pinned
4863 if (attr
.exclusive
|| attr
.pinned
)
4864 goto err_put_context
;
4867 event
= perf_event_alloc(&attr
, cpu
, ctx
, group_leader
,
4868 NULL
, NULL
, GFP_KERNEL
);
4869 err
= PTR_ERR(event
);
4871 goto err_put_context
;
4873 err
= anon_inode_getfd("[perf_event]", &perf_fops
, event
, O_RDWR
);
4875 goto err_free_put_context
;
4877 event_file
= fget_light(err
, &fput_needed2
);
4879 goto err_free_put_context
;
4881 if (flags
& PERF_FLAG_FD_OUTPUT
) {
4882 err
= perf_event_set_output(event
, group_fd
);
4884 goto err_fput_free_put_context
;
4887 event
->filp
= event_file
;
4888 WARN_ON_ONCE(ctx
->parent_ctx
);
4889 mutex_lock(&ctx
->mutex
);
4890 perf_install_in_context(ctx
, event
, cpu
);
4892 mutex_unlock(&ctx
->mutex
);
4894 event
->owner
= current
;
4895 get_task_struct(current
);
4896 mutex_lock(¤t
->perf_event_mutex
);
4897 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
4898 mutex_unlock(¤t
->perf_event_mutex
);
4900 err_fput_free_put_context
:
4901 fput_light(event_file
, fput_needed2
);
4903 err_free_put_context
:
4911 fput_light(group_file
, fput_needed
);
4917 * perf_event_create_kernel_counter
4919 * @attr: attributes of the counter to create
4920 * @cpu: cpu in which the counter is bound
4921 * @pid: task to profile
4924 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
4926 perf_overflow_handler_t overflow_handler
)
4928 struct perf_event
*event
;
4929 struct perf_event_context
*ctx
;
4933 * Get the target context (task or percpu):
4936 ctx
= find_get_context(pid
, cpu
);
4942 event
= perf_event_alloc(attr
, cpu
, ctx
, NULL
,
4943 NULL
, overflow_handler
, GFP_KERNEL
);
4944 if (IS_ERR(event
)) {
4945 err
= PTR_ERR(event
);
4946 goto err_put_context
;
4950 WARN_ON_ONCE(ctx
->parent_ctx
);
4951 mutex_lock(&ctx
->mutex
);
4952 perf_install_in_context(ctx
, event
, cpu
);
4954 mutex_unlock(&ctx
->mutex
);
4956 event
->owner
= current
;
4957 get_task_struct(current
);
4958 mutex_lock(¤t
->perf_event_mutex
);
4959 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
4960 mutex_unlock(¤t
->perf_event_mutex
);
4967 return ERR_PTR(err
);
4969 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
4972 * inherit a event from parent task to child task:
4974 static struct perf_event
*
4975 inherit_event(struct perf_event
*parent_event
,
4976 struct task_struct
*parent
,
4977 struct perf_event_context
*parent_ctx
,
4978 struct task_struct
*child
,
4979 struct perf_event
*group_leader
,
4980 struct perf_event_context
*child_ctx
)
4982 struct perf_event
*child_event
;
4985 * Instead of creating recursive hierarchies of events,
4986 * we link inherited events back to the original parent,
4987 * which has a filp for sure, which we use as the reference
4990 if (parent_event
->parent
)
4991 parent_event
= parent_event
->parent
;
4993 child_event
= perf_event_alloc(&parent_event
->attr
,
4994 parent_event
->cpu
, child_ctx
,
4995 group_leader
, parent_event
,
4997 if (IS_ERR(child_event
))
5002 * Make the child state follow the state of the parent event,
5003 * not its attr.disabled bit. We hold the parent's mutex,
5004 * so we won't race with perf_event_{en, dis}able_family.
5006 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
5007 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
5009 child_event
->state
= PERF_EVENT_STATE_OFF
;
5011 if (parent_event
->attr
.freq
) {
5012 u64 sample_period
= parent_event
->hw
.sample_period
;
5013 struct hw_perf_event
*hwc
= &child_event
->hw
;
5015 hwc
->sample_period
= sample_period
;
5016 hwc
->last_period
= sample_period
;
5018 atomic64_set(&hwc
->period_left
, sample_period
);
5021 child_event
->overflow_handler
= parent_event
->overflow_handler
;
5024 * Link it up in the child's context:
5026 add_event_to_ctx(child_event
, child_ctx
);
5029 * Get a reference to the parent filp - we will fput it
5030 * when the child event exits. This is safe to do because
5031 * we are in the parent and we know that the filp still
5032 * exists and has a nonzero count:
5034 atomic_long_inc(&parent_event
->filp
->f_count
);
5037 * Link this into the parent event's child list
5039 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5040 mutex_lock(&parent_event
->child_mutex
);
5041 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
5042 mutex_unlock(&parent_event
->child_mutex
);
5047 static int inherit_group(struct perf_event
*parent_event
,
5048 struct task_struct
*parent
,
5049 struct perf_event_context
*parent_ctx
,
5050 struct task_struct
*child
,
5051 struct perf_event_context
*child_ctx
)
5053 struct perf_event
*leader
;
5054 struct perf_event
*sub
;
5055 struct perf_event
*child_ctr
;
5057 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
5058 child
, NULL
, child_ctx
);
5060 return PTR_ERR(leader
);
5061 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
5062 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
5063 child
, leader
, child_ctx
);
5064 if (IS_ERR(child_ctr
))
5065 return PTR_ERR(child_ctr
);
5070 static void sync_child_event(struct perf_event
*child_event
,
5071 struct task_struct
*child
)
5073 struct perf_event
*parent_event
= child_event
->parent
;
5076 if (child_event
->attr
.inherit_stat
)
5077 perf_event_read_event(child_event
, child
);
5079 child_val
= atomic64_read(&child_event
->count
);
5082 * Add back the child's count to the parent's count:
5084 atomic64_add(child_val
, &parent_event
->count
);
5085 atomic64_add(child_event
->total_time_enabled
,
5086 &parent_event
->child_total_time_enabled
);
5087 atomic64_add(child_event
->total_time_running
,
5088 &parent_event
->child_total_time_running
);
5091 * Remove this event from the parent's list
5093 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5094 mutex_lock(&parent_event
->child_mutex
);
5095 list_del_init(&child_event
->child_list
);
5096 mutex_unlock(&parent_event
->child_mutex
);
5099 * Release the parent event, if this was the last
5102 fput(parent_event
->filp
);
5106 __perf_event_exit_task(struct perf_event
*child_event
,
5107 struct perf_event_context
*child_ctx
,
5108 struct task_struct
*child
)
5110 struct perf_event
*parent_event
;
5112 perf_event_remove_from_context(child_event
);
5114 parent_event
= child_event
->parent
;
5116 * It can happen that parent exits first, and has events
5117 * that are still around due to the child reference. These
5118 * events need to be zapped - but otherwise linger.
5121 sync_child_event(child_event
, child
);
5122 free_event(child_event
);
5127 * When a child task exits, feed back event values to parent events.
5129 void perf_event_exit_task(struct task_struct
*child
)
5131 struct perf_event
*child_event
, *tmp
;
5132 struct perf_event_context
*child_ctx
;
5133 unsigned long flags
;
5135 if (likely(!child
->perf_event_ctxp
)) {
5136 perf_event_task(child
, NULL
, 0);
5140 local_irq_save(flags
);
5142 * We can't reschedule here because interrupts are disabled,
5143 * and either child is current or it is a task that can't be
5144 * scheduled, so we are now safe from rescheduling changing
5147 child_ctx
= child
->perf_event_ctxp
;
5148 __perf_event_task_sched_out(child_ctx
);
5151 * Take the context lock here so that if find_get_context is
5152 * reading child->perf_event_ctxp, we wait until it has
5153 * incremented the context's refcount before we do put_ctx below.
5155 raw_spin_lock(&child_ctx
->lock
);
5156 child
->perf_event_ctxp
= NULL
;
5158 * If this context is a clone; unclone it so it can't get
5159 * swapped to another process while we're removing all
5160 * the events from it.
5162 unclone_ctx(child_ctx
);
5163 update_context_time(child_ctx
);
5164 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
5167 * Report the task dead after unscheduling the events so that we
5168 * won't get any samples after PERF_RECORD_EXIT. We can however still
5169 * get a few PERF_RECORD_READ events.
5171 perf_event_task(child
, child_ctx
, 0);
5174 * We can recurse on the same lock type through:
5176 * __perf_event_exit_task()
5177 * sync_child_event()
5178 * fput(parent_event->filp)
5180 * mutex_lock(&ctx->mutex)
5182 * But since its the parent context it won't be the same instance.
5184 mutex_lock_nested(&child_ctx
->mutex
, SINGLE_DEPTH_NESTING
);
5187 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
5189 __perf_event_exit_task(child_event
, child_ctx
, child
);
5191 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
5193 __perf_event_exit_task(child_event
, child_ctx
, child
);
5196 * If the last event was a group event, it will have appended all
5197 * its siblings to the list, but we obtained 'tmp' before that which
5198 * will still point to the list head terminating the iteration.
5200 if (!list_empty(&child_ctx
->pinned_groups
) ||
5201 !list_empty(&child_ctx
->flexible_groups
))
5204 mutex_unlock(&child_ctx
->mutex
);
5209 static void perf_free_event(struct perf_event
*event
,
5210 struct perf_event_context
*ctx
)
5212 struct perf_event
*parent
= event
->parent
;
5214 if (WARN_ON_ONCE(!parent
))
5217 mutex_lock(&parent
->child_mutex
);
5218 list_del_init(&event
->child_list
);
5219 mutex_unlock(&parent
->child_mutex
);
5223 list_del_event(event
, ctx
);
5228 * free an unexposed, unused context as created by inheritance by
5229 * init_task below, used by fork() in case of fail.
5231 void perf_event_free_task(struct task_struct
*task
)
5233 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
5234 struct perf_event
*event
, *tmp
;
5239 mutex_lock(&ctx
->mutex
);
5241 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5242 perf_free_event(event
, ctx
);
5244 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
5246 perf_free_event(event
, ctx
);
5248 if (!list_empty(&ctx
->pinned_groups
) ||
5249 !list_empty(&ctx
->flexible_groups
))
5252 mutex_unlock(&ctx
->mutex
);
5258 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
5259 struct perf_event_context
*parent_ctx
,
5260 struct task_struct
*child
,
5264 struct perf_event_context
*child_ctx
= child
->perf_event_ctxp
;
5266 if (!event
->attr
.inherit
) {
5273 * This is executed from the parent task context, so
5274 * inherit events that have been marked for cloning.
5275 * First allocate and initialize a context for the
5279 child_ctx
= kzalloc(sizeof(struct perf_event_context
),
5284 __perf_event_init_context(child_ctx
, child
);
5285 child
->perf_event_ctxp
= child_ctx
;
5286 get_task_struct(child
);
5289 ret
= inherit_group(event
, parent
, parent_ctx
,
5300 * Initialize the perf_event context in task_struct
5302 int perf_event_init_task(struct task_struct
*child
)
5304 struct perf_event_context
*child_ctx
, *parent_ctx
;
5305 struct perf_event_context
*cloned_ctx
;
5306 struct perf_event
*event
;
5307 struct task_struct
*parent
= current
;
5308 int inherited_all
= 1;
5311 child
->perf_event_ctxp
= NULL
;
5313 mutex_init(&child
->perf_event_mutex
);
5314 INIT_LIST_HEAD(&child
->perf_event_list
);
5316 if (likely(!parent
->perf_event_ctxp
))
5320 * If the parent's context is a clone, pin it so it won't get
5323 parent_ctx
= perf_pin_task_context(parent
);
5326 * No need to check if parent_ctx != NULL here; since we saw
5327 * it non-NULL earlier, the only reason for it to become NULL
5328 * is if we exit, and since we're currently in the middle of
5329 * a fork we can't be exiting at the same time.
5333 * Lock the parent list. No need to lock the child - not PID
5334 * hashed yet and not running, so nobody can access it.
5336 mutex_lock(&parent_ctx
->mutex
);
5339 * We dont have to disable NMIs - we are only looking at
5340 * the list, not manipulating it:
5342 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
5343 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5349 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
5350 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5356 child_ctx
= child
->perf_event_ctxp
;
5358 if (child_ctx
&& inherited_all
) {
5360 * Mark the child context as a clone of the parent
5361 * context, or of whatever the parent is a clone of.
5362 * Note that if the parent is a clone, it could get
5363 * uncloned at any point, but that doesn't matter
5364 * because the list of events and the generation
5365 * count can't have changed since we took the mutex.
5367 cloned_ctx
= rcu_dereference(parent_ctx
->parent_ctx
);
5369 child_ctx
->parent_ctx
= cloned_ctx
;
5370 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
5372 child_ctx
->parent_ctx
= parent_ctx
;
5373 child_ctx
->parent_gen
= parent_ctx
->generation
;
5375 get_ctx(child_ctx
->parent_ctx
);
5378 mutex_unlock(&parent_ctx
->mutex
);
5380 perf_unpin_context(parent_ctx
);
5385 static void __init
perf_event_init_all_cpus(void)
5388 struct perf_cpu_context
*cpuctx
;
5390 for_each_possible_cpu(cpu
) {
5391 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5392 __perf_event_init_context(&cpuctx
->ctx
, NULL
);
5396 static void __cpuinit
perf_event_init_cpu(int cpu
)
5398 struct perf_cpu_context
*cpuctx
;
5400 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5402 spin_lock(&perf_resource_lock
);
5403 cpuctx
->max_pertask
= perf_max_events
- perf_reserved_percpu
;
5404 spin_unlock(&perf_resource_lock
);
5407 #ifdef CONFIG_HOTPLUG_CPU
5408 static void __perf_event_exit_cpu(void *info
)
5410 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
5411 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5412 struct perf_event
*event
, *tmp
;
5414 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5415 __perf_event_remove_from_context(event
);
5416 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
5417 __perf_event_remove_from_context(event
);
5419 static void perf_event_exit_cpu(int cpu
)
5421 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5422 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5424 mutex_lock(&ctx
->mutex
);
5425 smp_call_function_single(cpu
, __perf_event_exit_cpu
, NULL
, 1);
5426 mutex_unlock(&ctx
->mutex
);
5429 static inline void perf_event_exit_cpu(int cpu
) { }
5432 static int __cpuinit
5433 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
5435 unsigned int cpu
= (long)hcpu
;
5439 case CPU_UP_PREPARE
:
5440 case CPU_UP_PREPARE_FROZEN
:
5441 perf_event_init_cpu(cpu
);
5444 case CPU_DOWN_PREPARE
:
5445 case CPU_DOWN_PREPARE_FROZEN
:
5446 perf_event_exit_cpu(cpu
);
5457 * This has to have a higher priority than migration_notifier in sched.c.
5459 static struct notifier_block __cpuinitdata perf_cpu_nb
= {
5460 .notifier_call
= perf_cpu_notify
,
5464 void __init
perf_event_init(void)
5466 perf_event_init_all_cpus();
5467 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_UP_PREPARE
,
5468 (void *)(long)smp_processor_id());
5469 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_ONLINE
,
5470 (void *)(long)smp_processor_id());
5471 register_cpu_notifier(&perf_cpu_nb
);
5474 static ssize_t
perf_show_reserve_percpu(struct sysdev_class
*class,
5475 struct sysdev_class_attribute
*attr
,
5478 return sprintf(buf
, "%d\n", perf_reserved_percpu
);
5482 perf_set_reserve_percpu(struct sysdev_class
*class,
5483 struct sysdev_class_attribute
*attr
,
5487 struct perf_cpu_context
*cpuctx
;
5491 err
= strict_strtoul(buf
, 10, &val
);
5494 if (val
> perf_max_events
)
5497 spin_lock(&perf_resource_lock
);
5498 perf_reserved_percpu
= val
;
5499 for_each_online_cpu(cpu
) {
5500 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5501 raw_spin_lock_irq(&cpuctx
->ctx
.lock
);
5502 mpt
= min(perf_max_events
- cpuctx
->ctx
.nr_events
,
5503 perf_max_events
- perf_reserved_percpu
);
5504 cpuctx
->max_pertask
= mpt
;
5505 raw_spin_unlock_irq(&cpuctx
->ctx
.lock
);
5507 spin_unlock(&perf_resource_lock
);
5512 static ssize_t
perf_show_overcommit(struct sysdev_class
*class,
5513 struct sysdev_class_attribute
*attr
,
5516 return sprintf(buf
, "%d\n", perf_overcommit
);
5520 perf_set_overcommit(struct sysdev_class
*class,
5521 struct sysdev_class_attribute
*attr
,
5522 const char *buf
, size_t count
)
5527 err
= strict_strtoul(buf
, 10, &val
);
5533 spin_lock(&perf_resource_lock
);
5534 perf_overcommit
= val
;
5535 spin_unlock(&perf_resource_lock
);
5540 static SYSDEV_CLASS_ATTR(
5543 perf_show_reserve_percpu
,
5544 perf_set_reserve_percpu
5547 static SYSDEV_CLASS_ATTR(
5550 perf_show_overcommit
,
5554 static struct attribute
*perfclass_attrs
[] = {
5555 &attr_reserve_percpu
.attr
,
5556 &attr_overcommit
.attr
,
5560 static struct attribute_group perfclass_attr_group
= {
5561 .attrs
= perfclass_attrs
,
5562 .name
= "perf_events",
5565 static int __init
perf_event_sysfs_init(void)
5567 return sysfs_create_group(&cpu_sysdev_class
.kset
.kobj
,
5568 &perfclass_attr_group
);
5570 device_initcall(perf_event_sysfs_init
);