2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/file.h>
17 #include <linux/poll.h>
18 #include <linux/sysfs.h>
19 #include <linux/dcache.h>
20 #include <linux/percpu.h>
21 #include <linux/ptrace.h>
22 #include <linux/vmstat.h>
23 #include <linux/vmalloc.h>
24 #include <linux/hardirq.h>
25 #include <linux/rculist.h>
26 #include <linux/uaccess.h>
27 #include <linux/syscalls.h>
28 #include <linux/anon_inodes.h>
29 #include <linux/kernel_stat.h>
30 #include <linux/perf_event.h>
31 #include <linux/ftrace_event.h>
32 #include <linux/hw_breakpoint.h>
34 #include <asm/irq_regs.h>
37 * Each CPU has a list of per CPU events:
39 static DEFINE_PER_CPU(struct perf_cpu_context
, perf_cpu_context
);
41 int perf_max_events __read_mostly
= 1;
42 static int perf_reserved_percpu __read_mostly
;
43 static int perf_overcommit __read_mostly
= 1;
45 static atomic_t nr_events __read_mostly
;
46 static atomic_t nr_mmap_events __read_mostly
;
47 static atomic_t nr_comm_events __read_mostly
;
48 static atomic_t nr_task_events __read_mostly
;
51 * perf event paranoia level:
52 * -1 - not paranoid at all
53 * 0 - disallow raw tracepoint access for unpriv
54 * 1 - disallow cpu events for unpriv
55 * 2 - disallow kernel profiling for unpriv
57 int sysctl_perf_event_paranoid __read_mostly
= 1;
59 int sysctl_perf_event_mlock __read_mostly
= 512; /* 'free' kb per user */
62 * max perf event sample rate
64 int sysctl_perf_event_sample_rate __read_mostly
= 100000;
66 static atomic64_t perf_event_id
;
69 * Lock for (sysadmin-configurable) event reservations:
71 static DEFINE_SPINLOCK(perf_resource_lock
);
74 * Architecture provided APIs - weak aliases:
76 extern __weak
const struct pmu
*hw_perf_event_init(struct perf_event
*event
)
81 void __weak
hw_perf_disable(void) { barrier(); }
82 void __weak
hw_perf_enable(void) { barrier(); }
84 void __weak
hw_perf_event_setup(int cpu
) { barrier(); }
85 void __weak
hw_perf_event_setup_online(int cpu
) { barrier(); }
86 void __weak
hw_perf_event_setup_offline(int cpu
) { barrier(); }
89 hw_perf_group_sched_in(struct perf_event
*group_leader
,
90 struct perf_cpu_context
*cpuctx
,
91 struct perf_event_context
*ctx
)
96 void __weak
perf_event_print_debug(void) { }
98 static DEFINE_PER_CPU(int, perf_disable_count
);
100 void __perf_disable(void)
102 __get_cpu_var(perf_disable_count
)++;
105 bool __perf_enable(void)
107 return !--__get_cpu_var(perf_disable_count
);
110 void perf_disable(void)
116 void perf_enable(void)
122 static void get_ctx(struct perf_event_context
*ctx
)
124 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
127 static void free_ctx(struct rcu_head
*head
)
129 struct perf_event_context
*ctx
;
131 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
135 static void put_ctx(struct perf_event_context
*ctx
)
137 if (atomic_dec_and_test(&ctx
->refcount
)) {
139 put_ctx(ctx
->parent_ctx
);
141 put_task_struct(ctx
->task
);
142 call_rcu(&ctx
->rcu_head
, free_ctx
);
146 static void unclone_ctx(struct perf_event_context
*ctx
)
148 if (ctx
->parent_ctx
) {
149 put_ctx(ctx
->parent_ctx
);
150 ctx
->parent_ctx
= NULL
;
155 * If we inherit events we want to return the parent event id
158 static u64
primary_event_id(struct perf_event
*event
)
163 id
= event
->parent
->id
;
169 * Get the perf_event_context for a task and lock it.
170 * This has to cope with with the fact that until it is locked,
171 * the context could get moved to another task.
173 static struct perf_event_context
*
174 perf_lock_task_context(struct task_struct
*task
, unsigned long *flags
)
176 struct perf_event_context
*ctx
;
180 ctx
= rcu_dereference(task
->perf_event_ctxp
);
183 * If this context is a clone of another, it might
184 * get swapped for another underneath us by
185 * perf_event_task_sched_out, though the
186 * rcu_read_lock() protects us from any context
187 * getting freed. Lock the context and check if it
188 * got swapped before we could get the lock, and retry
189 * if so. If we locked the right context, then it
190 * can't get swapped on us any more.
192 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
193 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
)) {
194 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
198 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
199 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
208 * Get the context for a task and increment its pin_count so it
209 * can't get swapped to another task. This also increments its
210 * reference count so that the context can't get freed.
212 static struct perf_event_context
*perf_pin_task_context(struct task_struct
*task
)
214 struct perf_event_context
*ctx
;
217 ctx
= perf_lock_task_context(task
, &flags
);
220 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
225 static void perf_unpin_context(struct perf_event_context
*ctx
)
229 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
231 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
235 static inline u64
perf_clock(void)
237 return cpu_clock(raw_smp_processor_id());
241 * Update the record of the current time in a context.
243 static void update_context_time(struct perf_event_context
*ctx
)
245 u64 now
= perf_clock();
247 ctx
->time
+= now
- ctx
->timestamp
;
248 ctx
->timestamp
= now
;
252 * Update the total_time_enabled and total_time_running fields for a event.
254 static void update_event_times(struct perf_event
*event
)
256 struct perf_event_context
*ctx
= event
->ctx
;
259 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
260 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
266 run_end
= event
->tstamp_stopped
;
268 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
270 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
271 run_end
= event
->tstamp_stopped
;
275 event
->total_time_running
= run_end
- event
->tstamp_running
;
278 static struct list_head
*
279 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
281 if (event
->attr
.pinned
)
282 return &ctx
->pinned_groups
;
284 return &ctx
->flexible_groups
;
288 * Add a event from the lists for its context.
289 * Must be called with ctx->mutex and ctx->lock held.
292 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
294 struct perf_event
*group_leader
= event
->group_leader
;
297 * Depending on whether it is a standalone or sibling event,
298 * add it straight to the context's event list, or to the group
299 * leader's sibling list:
301 if (group_leader
== event
) {
302 struct list_head
*list
;
304 if (is_software_event(event
))
305 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
307 list
= ctx_group_list(event
, ctx
);
308 list_add_tail(&event
->group_entry
, list
);
310 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
311 !is_software_event(event
))
312 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
314 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
315 group_leader
->nr_siblings
++;
318 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
320 if (event
->attr
.inherit_stat
)
325 * Remove a event from the lists for its context.
326 * Must be called with ctx->mutex and ctx->lock held.
329 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
331 struct perf_event
*sibling
, *tmp
;
333 if (list_empty(&event
->group_entry
))
336 if (event
->attr
.inherit_stat
)
339 list_del_init(&event
->group_entry
);
340 list_del_rcu(&event
->event_entry
);
342 if (event
->group_leader
!= event
)
343 event
->group_leader
->nr_siblings
--;
345 update_event_times(event
);
348 * If event was in error state, then keep it
349 * that way, otherwise bogus counts will be
350 * returned on read(). The only way to get out
351 * of error state is by explicit re-enabling
354 if (event
->state
> PERF_EVENT_STATE_OFF
)
355 event
->state
= PERF_EVENT_STATE_OFF
;
358 * If this was a group event with sibling events then
359 * upgrade the siblings to singleton events by adding them
360 * to the context list directly:
362 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
363 struct list_head
*list
;
365 list
= ctx_group_list(event
, ctx
);
366 list_move_tail(&sibling
->group_entry
, list
);
367 sibling
->group_leader
= sibling
;
369 /* Inherit group flags from the previous leader */
370 sibling
->group_flags
= event
->group_flags
;
375 event_sched_out(struct perf_event
*event
,
376 struct perf_cpu_context
*cpuctx
,
377 struct perf_event_context
*ctx
)
379 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
382 event
->state
= PERF_EVENT_STATE_INACTIVE
;
383 if (event
->pending_disable
) {
384 event
->pending_disable
= 0;
385 event
->state
= PERF_EVENT_STATE_OFF
;
387 event
->tstamp_stopped
= ctx
->time
;
388 event
->pmu
->disable(event
);
391 if (!is_software_event(event
))
392 cpuctx
->active_oncpu
--;
394 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
395 cpuctx
->exclusive
= 0;
399 group_sched_out(struct perf_event
*group_event
,
400 struct perf_cpu_context
*cpuctx
,
401 struct perf_event_context
*ctx
)
403 struct perf_event
*event
;
405 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
408 event_sched_out(group_event
, cpuctx
, ctx
);
411 * Schedule out siblings (if any):
413 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
414 event_sched_out(event
, cpuctx
, ctx
);
416 if (group_event
->attr
.exclusive
)
417 cpuctx
->exclusive
= 0;
421 * Cross CPU call to remove a performance event
423 * We disable the event on the hardware level first. After that we
424 * remove it from the context list.
426 static void __perf_event_remove_from_context(void *info
)
428 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
429 struct perf_event
*event
= info
;
430 struct perf_event_context
*ctx
= event
->ctx
;
433 * If this is a task context, we need to check whether it is
434 * the current task context of this cpu. If not it has been
435 * scheduled out before the smp call arrived.
437 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
440 raw_spin_lock(&ctx
->lock
);
442 * Protect the list operation against NMI by disabling the
443 * events on a global level.
447 event_sched_out(event
, cpuctx
, ctx
);
449 list_del_event(event
, ctx
);
453 * Allow more per task events with respect to the
456 cpuctx
->max_pertask
=
457 min(perf_max_events
- ctx
->nr_events
,
458 perf_max_events
- perf_reserved_percpu
);
462 raw_spin_unlock(&ctx
->lock
);
467 * Remove the event from a task's (or a CPU's) list of events.
469 * Must be called with ctx->mutex held.
471 * CPU events are removed with a smp call. For task events we only
472 * call when the task is on a CPU.
474 * If event->ctx is a cloned context, callers must make sure that
475 * every task struct that event->ctx->task could possibly point to
476 * remains valid. This is OK when called from perf_release since
477 * that only calls us on the top-level context, which can't be a clone.
478 * When called from perf_event_exit_task, it's OK because the
479 * context has been detached from its task.
481 static void perf_event_remove_from_context(struct perf_event
*event
)
483 struct perf_event_context
*ctx
= event
->ctx
;
484 struct task_struct
*task
= ctx
->task
;
488 * Per cpu events are removed via an smp call and
489 * the removal is always successful.
491 smp_call_function_single(event
->cpu
,
492 __perf_event_remove_from_context
,
498 task_oncpu_function_call(task
, __perf_event_remove_from_context
,
501 raw_spin_lock_irq(&ctx
->lock
);
503 * If the context is active we need to retry the smp call.
505 if (ctx
->nr_active
&& !list_empty(&event
->group_entry
)) {
506 raw_spin_unlock_irq(&ctx
->lock
);
511 * The lock prevents that this context is scheduled in so we
512 * can remove the event safely, if the call above did not
515 if (!list_empty(&event
->group_entry
))
516 list_del_event(event
, ctx
);
517 raw_spin_unlock_irq(&ctx
->lock
);
521 * Update total_time_enabled and total_time_running for all events in a group.
523 static void update_group_times(struct perf_event
*leader
)
525 struct perf_event
*event
;
527 update_event_times(leader
);
528 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
529 update_event_times(event
);
533 * Cross CPU call to disable a performance event
535 static void __perf_event_disable(void *info
)
537 struct perf_event
*event
= info
;
538 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
539 struct perf_event_context
*ctx
= event
->ctx
;
542 * If this is a per-task event, need to check whether this
543 * event's task is the current task on this cpu.
545 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
548 raw_spin_lock(&ctx
->lock
);
551 * If the event is on, turn it off.
552 * If it is in error state, leave it in error state.
554 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
555 update_context_time(ctx
);
556 update_group_times(event
);
557 if (event
== event
->group_leader
)
558 group_sched_out(event
, cpuctx
, ctx
);
560 event_sched_out(event
, cpuctx
, ctx
);
561 event
->state
= PERF_EVENT_STATE_OFF
;
564 raw_spin_unlock(&ctx
->lock
);
570 * If event->ctx is a cloned context, callers must make sure that
571 * every task struct that event->ctx->task could possibly point to
572 * remains valid. This condition is satisifed when called through
573 * perf_event_for_each_child or perf_event_for_each because they
574 * hold the top-level event's child_mutex, so any descendant that
575 * goes to exit will block in sync_child_event.
576 * When called from perf_pending_event it's OK because event->ctx
577 * is the current context on this CPU and preemption is disabled,
578 * hence we can't get into perf_event_task_sched_out for this context.
580 void perf_event_disable(struct perf_event
*event
)
582 struct perf_event_context
*ctx
= event
->ctx
;
583 struct task_struct
*task
= ctx
->task
;
587 * Disable the event on the cpu that it's on
589 smp_call_function_single(event
->cpu
, __perf_event_disable
,
595 task_oncpu_function_call(task
, __perf_event_disable
, event
);
597 raw_spin_lock_irq(&ctx
->lock
);
599 * If the event is still active, we need to retry the cross-call.
601 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
602 raw_spin_unlock_irq(&ctx
->lock
);
607 * Since we have the lock this context can't be scheduled
608 * in, so we can change the state safely.
610 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
611 update_group_times(event
);
612 event
->state
= PERF_EVENT_STATE_OFF
;
615 raw_spin_unlock_irq(&ctx
->lock
);
619 event_sched_in(struct perf_event
*event
,
620 struct perf_cpu_context
*cpuctx
,
621 struct perf_event_context
*ctx
)
623 if (event
->state
<= PERF_EVENT_STATE_OFF
)
626 event
->state
= PERF_EVENT_STATE_ACTIVE
;
627 event
->oncpu
= smp_processor_id();
629 * The new state must be visible before we turn it on in the hardware:
633 if (event
->pmu
->enable(event
)) {
634 event
->state
= PERF_EVENT_STATE_INACTIVE
;
639 event
->tstamp_running
+= ctx
->time
- event
->tstamp_stopped
;
641 if (!is_software_event(event
))
642 cpuctx
->active_oncpu
++;
645 if (event
->attr
.exclusive
)
646 cpuctx
->exclusive
= 1;
652 group_sched_in(struct perf_event
*group_event
,
653 struct perf_cpu_context
*cpuctx
,
654 struct perf_event_context
*ctx
)
656 struct perf_event
*event
, *partial_group
;
659 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
662 ret
= hw_perf_group_sched_in(group_event
, cpuctx
, ctx
);
664 return ret
< 0 ? ret
: 0;
666 if (event_sched_in(group_event
, cpuctx
, ctx
))
670 * Schedule in siblings as one group (if any):
672 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
673 if (event_sched_in(event
, cpuctx
, ctx
)) {
674 partial_group
= event
;
683 * Groups can be scheduled in as one unit only, so undo any
684 * partial group before returning:
686 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
687 if (event
== partial_group
)
689 event_sched_out(event
, cpuctx
, ctx
);
691 event_sched_out(group_event
, cpuctx
, ctx
);
697 * Work out whether we can put this event group on the CPU now.
699 static int group_can_go_on(struct perf_event
*event
,
700 struct perf_cpu_context
*cpuctx
,
704 * Groups consisting entirely of software events can always go on.
706 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
709 * If an exclusive group is already on, no other hardware
712 if (cpuctx
->exclusive
)
715 * If this group is exclusive and there are already
716 * events on the CPU, it can't go on.
718 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
721 * Otherwise, try to add it if all previous groups were able
727 static void add_event_to_ctx(struct perf_event
*event
,
728 struct perf_event_context
*ctx
)
730 list_add_event(event
, ctx
);
731 event
->tstamp_enabled
= ctx
->time
;
732 event
->tstamp_running
= ctx
->time
;
733 event
->tstamp_stopped
= ctx
->time
;
737 * Cross CPU call to install and enable a performance event
739 * Must be called with ctx->mutex held
741 static void __perf_install_in_context(void *info
)
743 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
744 struct perf_event
*event
= info
;
745 struct perf_event_context
*ctx
= event
->ctx
;
746 struct perf_event
*leader
= event
->group_leader
;
750 * If this is a task context, we need to check whether it is
751 * the current task context of this cpu. If not it has been
752 * scheduled out before the smp call arrived.
753 * Or possibly this is the right context but it isn't
754 * on this cpu because it had no events.
756 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
757 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
759 cpuctx
->task_ctx
= ctx
;
762 raw_spin_lock(&ctx
->lock
);
764 update_context_time(ctx
);
767 * Protect the list operation against NMI by disabling the
768 * events on a global level. NOP for non NMI based events.
772 add_event_to_ctx(event
, ctx
);
774 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
778 * Don't put the event on if it is disabled or if
779 * it is in a group and the group isn't on.
781 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
782 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
786 * An exclusive event can't go on if there are already active
787 * hardware events, and no hardware event can go on if there
788 * is already an exclusive event on.
790 if (!group_can_go_on(event
, cpuctx
, 1))
793 err
= event_sched_in(event
, cpuctx
, ctx
);
797 * This event couldn't go on. If it is in a group
798 * then we have to pull the whole group off.
799 * If the event group is pinned then put it in error state.
802 group_sched_out(leader
, cpuctx
, ctx
);
803 if (leader
->attr
.pinned
) {
804 update_group_times(leader
);
805 leader
->state
= PERF_EVENT_STATE_ERROR
;
809 if (!err
&& !ctx
->task
&& cpuctx
->max_pertask
)
810 cpuctx
->max_pertask
--;
815 raw_spin_unlock(&ctx
->lock
);
819 * Attach a performance event to a context
821 * First we add the event to the list with the hardware enable bit
822 * in event->hw_config cleared.
824 * If the event is attached to a task which is on a CPU we use a smp
825 * call to enable it in the task context. The task might have been
826 * scheduled away, but we check this in the smp call again.
828 * Must be called with ctx->mutex held.
831 perf_install_in_context(struct perf_event_context
*ctx
,
832 struct perf_event
*event
,
835 struct task_struct
*task
= ctx
->task
;
839 * Per cpu events are installed via an smp call and
840 * the install is always successful.
842 smp_call_function_single(cpu
, __perf_install_in_context
,
848 task_oncpu_function_call(task
, __perf_install_in_context
,
851 raw_spin_lock_irq(&ctx
->lock
);
853 * we need to retry the smp call.
855 if (ctx
->is_active
&& list_empty(&event
->group_entry
)) {
856 raw_spin_unlock_irq(&ctx
->lock
);
861 * The lock prevents that this context is scheduled in so we
862 * can add the event safely, if it the call above did not
865 if (list_empty(&event
->group_entry
))
866 add_event_to_ctx(event
, ctx
);
867 raw_spin_unlock_irq(&ctx
->lock
);
871 * Put a event into inactive state and update time fields.
872 * Enabling the leader of a group effectively enables all
873 * the group members that aren't explicitly disabled, so we
874 * have to update their ->tstamp_enabled also.
875 * Note: this works for group members as well as group leaders
876 * since the non-leader members' sibling_lists will be empty.
878 static void __perf_event_mark_enabled(struct perf_event
*event
,
879 struct perf_event_context
*ctx
)
881 struct perf_event
*sub
;
883 event
->state
= PERF_EVENT_STATE_INACTIVE
;
884 event
->tstamp_enabled
= ctx
->time
- event
->total_time_enabled
;
885 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
)
886 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
887 sub
->tstamp_enabled
=
888 ctx
->time
- sub
->total_time_enabled
;
892 * Cross CPU call to enable a performance event
894 static void __perf_event_enable(void *info
)
896 struct perf_event
*event
= info
;
897 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
898 struct perf_event_context
*ctx
= event
->ctx
;
899 struct perf_event
*leader
= event
->group_leader
;
903 * If this is a per-task event, need to check whether this
904 * event's task is the current task on this cpu.
906 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
907 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
909 cpuctx
->task_ctx
= ctx
;
912 raw_spin_lock(&ctx
->lock
);
914 update_context_time(ctx
);
916 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
918 __perf_event_mark_enabled(event
, ctx
);
920 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
924 * If the event is in a group and isn't the group leader,
925 * then don't put it on unless the group is on.
927 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
930 if (!group_can_go_on(event
, cpuctx
, 1)) {
935 err
= group_sched_in(event
, cpuctx
, ctx
);
937 err
= event_sched_in(event
, cpuctx
, ctx
);
943 * If this event can't go on and it's part of a
944 * group, then the whole group has to come off.
947 group_sched_out(leader
, cpuctx
, ctx
);
948 if (leader
->attr
.pinned
) {
949 update_group_times(leader
);
950 leader
->state
= PERF_EVENT_STATE_ERROR
;
955 raw_spin_unlock(&ctx
->lock
);
961 * If event->ctx is a cloned context, callers must make sure that
962 * every task struct that event->ctx->task could possibly point to
963 * remains valid. This condition is satisfied when called through
964 * perf_event_for_each_child or perf_event_for_each as described
965 * for perf_event_disable.
967 void perf_event_enable(struct perf_event
*event
)
969 struct perf_event_context
*ctx
= event
->ctx
;
970 struct task_struct
*task
= ctx
->task
;
974 * Enable the event on the cpu that it's on
976 smp_call_function_single(event
->cpu
, __perf_event_enable
,
981 raw_spin_lock_irq(&ctx
->lock
);
982 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
986 * If the event is in error state, clear that first.
987 * That way, if we see the event in error state below, we
988 * know that it has gone back into error state, as distinct
989 * from the task having been scheduled away before the
990 * cross-call arrived.
992 if (event
->state
== PERF_EVENT_STATE_ERROR
)
993 event
->state
= PERF_EVENT_STATE_OFF
;
996 raw_spin_unlock_irq(&ctx
->lock
);
997 task_oncpu_function_call(task
, __perf_event_enable
, event
);
999 raw_spin_lock_irq(&ctx
->lock
);
1002 * If the context is active and the event is still off,
1003 * we need to retry the cross-call.
1005 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
)
1009 * Since we have the lock this context can't be scheduled
1010 * in, so we can change the state safely.
1012 if (event
->state
== PERF_EVENT_STATE_OFF
)
1013 __perf_event_mark_enabled(event
, ctx
);
1016 raw_spin_unlock_irq(&ctx
->lock
);
1019 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1022 * not supported on inherited events
1024 if (event
->attr
.inherit
)
1027 atomic_add(refresh
, &event
->event_limit
);
1028 perf_event_enable(event
);
1034 EVENT_FLEXIBLE
= 0x1,
1036 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
1039 static void ctx_sched_out(struct perf_event_context
*ctx
,
1040 struct perf_cpu_context
*cpuctx
,
1041 enum event_type_t event_type
)
1043 struct perf_event
*event
;
1045 raw_spin_lock(&ctx
->lock
);
1047 if (likely(!ctx
->nr_events
))
1049 update_context_time(ctx
);
1052 if (!ctx
->nr_active
)
1055 if (event_type
& EVENT_PINNED
)
1056 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1057 group_sched_out(event
, cpuctx
, ctx
);
1059 if (event_type
& EVENT_FLEXIBLE
)
1060 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1061 group_sched_out(event
, cpuctx
, ctx
);
1066 raw_spin_unlock(&ctx
->lock
);
1070 * Test whether two contexts are equivalent, i.e. whether they
1071 * have both been cloned from the same version of the same context
1072 * and they both have the same number of enabled events.
1073 * If the number of enabled events is the same, then the set
1074 * of enabled events should be the same, because these are both
1075 * inherited contexts, therefore we can't access individual events
1076 * in them directly with an fd; we can only enable/disable all
1077 * events via prctl, or enable/disable all events in a family
1078 * via ioctl, which will have the same effect on both contexts.
1080 static int context_equiv(struct perf_event_context
*ctx1
,
1081 struct perf_event_context
*ctx2
)
1083 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1084 && ctx1
->parent_gen
== ctx2
->parent_gen
1085 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1088 static void __perf_event_sync_stat(struct perf_event
*event
,
1089 struct perf_event
*next_event
)
1093 if (!event
->attr
.inherit_stat
)
1097 * Update the event value, we cannot use perf_event_read()
1098 * because we're in the middle of a context switch and have IRQs
1099 * disabled, which upsets smp_call_function_single(), however
1100 * we know the event must be on the current CPU, therefore we
1101 * don't need to use it.
1103 switch (event
->state
) {
1104 case PERF_EVENT_STATE_ACTIVE
:
1105 event
->pmu
->read(event
);
1108 case PERF_EVENT_STATE_INACTIVE
:
1109 update_event_times(event
);
1117 * In order to keep per-task stats reliable we need to flip the event
1118 * values when we flip the contexts.
1120 value
= atomic64_read(&next_event
->count
);
1121 value
= atomic64_xchg(&event
->count
, value
);
1122 atomic64_set(&next_event
->count
, value
);
1124 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1125 swap(event
->total_time_running
, next_event
->total_time_running
);
1128 * Since we swizzled the values, update the user visible data too.
1130 perf_event_update_userpage(event
);
1131 perf_event_update_userpage(next_event
);
1134 #define list_next_entry(pos, member) \
1135 list_entry(pos->member.next, typeof(*pos), member)
1137 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1138 struct perf_event_context
*next_ctx
)
1140 struct perf_event
*event
, *next_event
;
1145 update_context_time(ctx
);
1147 event
= list_first_entry(&ctx
->event_list
,
1148 struct perf_event
, event_entry
);
1150 next_event
= list_first_entry(&next_ctx
->event_list
,
1151 struct perf_event
, event_entry
);
1153 while (&event
->event_entry
!= &ctx
->event_list
&&
1154 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1156 __perf_event_sync_stat(event
, next_event
);
1158 event
= list_next_entry(event
, event_entry
);
1159 next_event
= list_next_entry(next_event
, event_entry
);
1164 * Called from scheduler to remove the events of the current task,
1165 * with interrupts disabled.
1167 * We stop each event and update the event value in event->count.
1169 * This does not protect us against NMI, but disable()
1170 * sets the disabled bit in the control field of event _before_
1171 * accessing the event control register. If a NMI hits, then it will
1172 * not restart the event.
1174 void perf_event_task_sched_out(struct task_struct
*task
,
1175 struct task_struct
*next
)
1177 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1178 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1179 struct perf_event_context
*next_ctx
;
1180 struct perf_event_context
*parent
;
1181 struct pt_regs
*regs
;
1184 regs
= task_pt_regs(task
);
1185 perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES
, 1, 1, regs
, 0);
1187 if (likely(!ctx
|| !cpuctx
->task_ctx
))
1191 parent
= rcu_dereference(ctx
->parent_ctx
);
1192 next_ctx
= next
->perf_event_ctxp
;
1193 if (parent
&& next_ctx
&&
1194 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1196 * Looks like the two contexts are clones, so we might be
1197 * able to optimize the context switch. We lock both
1198 * contexts and check that they are clones under the
1199 * lock (including re-checking that neither has been
1200 * uncloned in the meantime). It doesn't matter which
1201 * order we take the locks because no other cpu could
1202 * be trying to lock both of these tasks.
1204 raw_spin_lock(&ctx
->lock
);
1205 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1206 if (context_equiv(ctx
, next_ctx
)) {
1208 * XXX do we need a memory barrier of sorts
1209 * wrt to rcu_dereference() of perf_event_ctxp
1211 task
->perf_event_ctxp
= next_ctx
;
1212 next
->perf_event_ctxp
= ctx
;
1214 next_ctx
->task
= task
;
1217 perf_event_sync_stat(ctx
, next_ctx
);
1219 raw_spin_unlock(&next_ctx
->lock
);
1220 raw_spin_unlock(&ctx
->lock
);
1225 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1226 cpuctx
->task_ctx
= NULL
;
1230 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1231 enum event_type_t event_type
)
1233 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1235 if (!cpuctx
->task_ctx
)
1238 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1241 ctx_sched_out(ctx
, cpuctx
, event_type
);
1242 cpuctx
->task_ctx
= NULL
;
1246 * Called with IRQs disabled
1248 static void __perf_event_task_sched_out(struct perf_event_context
*ctx
)
1250 task_ctx_sched_out(ctx
, EVENT_ALL
);
1254 * Called with IRQs disabled
1256 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1257 enum event_type_t event_type
)
1259 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1263 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1264 struct perf_cpu_context
*cpuctx
)
1266 struct perf_event
*event
;
1268 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1269 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1271 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1274 if (group_can_go_on(event
, cpuctx
, 1))
1275 group_sched_in(event
, cpuctx
, ctx
);
1278 * If this pinned group hasn't been scheduled,
1279 * put it in error state.
1281 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1282 update_group_times(event
);
1283 event
->state
= PERF_EVENT_STATE_ERROR
;
1289 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
1290 struct perf_cpu_context
*cpuctx
)
1292 struct perf_event
*event
;
1295 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1296 /* Ignore events in OFF or ERROR state */
1297 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1300 * Listen to the 'cpu' scheduling filter constraint
1303 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1306 if (group_can_go_on(event
, cpuctx
, can_add_hw
))
1307 if (group_sched_in(event
, cpuctx
, ctx
))
1313 ctx_sched_in(struct perf_event_context
*ctx
,
1314 struct perf_cpu_context
*cpuctx
,
1315 enum event_type_t event_type
)
1317 raw_spin_lock(&ctx
->lock
);
1319 if (likely(!ctx
->nr_events
))
1322 ctx
->timestamp
= perf_clock();
1327 * First go through the list and put on any pinned groups
1328 * in order to give them the best chance of going on.
1330 if (event_type
& EVENT_PINNED
)
1331 ctx_pinned_sched_in(ctx
, cpuctx
);
1333 /* Then walk through the lower prio flexible groups */
1334 if (event_type
& EVENT_FLEXIBLE
)
1335 ctx_flexible_sched_in(ctx
, cpuctx
);
1339 raw_spin_unlock(&ctx
->lock
);
1342 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
1343 enum event_type_t event_type
)
1345 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
1347 ctx_sched_in(ctx
, cpuctx
, event_type
);
1350 static void task_ctx_sched_in(struct task_struct
*task
,
1351 enum event_type_t event_type
)
1353 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1354 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1358 if (cpuctx
->task_ctx
== ctx
)
1360 ctx_sched_in(ctx
, cpuctx
, event_type
);
1361 cpuctx
->task_ctx
= ctx
;
1364 * Called from scheduler to add the events of the current task
1365 * with interrupts disabled.
1367 * We restore the event value and then enable it.
1369 * This does not protect us against NMI, but enable()
1370 * sets the enabled bit in the control field of event _before_
1371 * accessing the event control register. If a NMI hits, then it will
1372 * keep the event running.
1374 void perf_event_task_sched_in(struct task_struct
*task
)
1376 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1377 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1382 if (cpuctx
->task_ctx
== ctx
)
1386 * We want to keep the following priority order:
1387 * cpu pinned (that don't need to move), task pinned,
1388 * cpu flexible, task flexible.
1390 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1392 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
);
1393 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1394 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
);
1396 cpuctx
->task_ctx
= ctx
;
1399 #define MAX_INTERRUPTS (~0ULL)
1401 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1403 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1405 u64 frequency
= event
->attr
.sample_freq
;
1406 u64 sec
= NSEC_PER_SEC
;
1407 u64 divisor
, dividend
;
1409 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
1411 count_fls
= fls64(count
);
1412 nsec_fls
= fls64(nsec
);
1413 frequency_fls
= fls64(frequency
);
1417 * We got @count in @nsec, with a target of sample_freq HZ
1418 * the target period becomes:
1421 * period = -------------------
1422 * @nsec * sample_freq
1427 * Reduce accuracy by one bit such that @a and @b converge
1428 * to a similar magnitude.
1430 #define REDUCE_FLS(a, b) \
1432 if (a##_fls > b##_fls) { \
1442 * Reduce accuracy until either term fits in a u64, then proceed with
1443 * the other, so that finally we can do a u64/u64 division.
1445 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
1446 REDUCE_FLS(nsec
, frequency
);
1447 REDUCE_FLS(sec
, count
);
1450 if (count_fls
+ sec_fls
> 64) {
1451 divisor
= nsec
* frequency
;
1453 while (count_fls
+ sec_fls
> 64) {
1454 REDUCE_FLS(count
, sec
);
1458 dividend
= count
* sec
;
1460 dividend
= count
* sec
;
1462 while (nsec_fls
+ frequency_fls
> 64) {
1463 REDUCE_FLS(nsec
, frequency
);
1467 divisor
= nsec
* frequency
;
1470 return div64_u64(dividend
, divisor
);
1473 static void perf_event_stop(struct perf_event
*event
)
1475 if (!event
->pmu
->stop
)
1476 return event
->pmu
->disable(event
);
1478 return event
->pmu
->stop(event
);
1481 static int perf_event_start(struct perf_event
*event
)
1483 if (!event
->pmu
->start
)
1484 return event
->pmu
->enable(event
);
1486 return event
->pmu
->start(event
);
1489 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1491 struct hw_perf_event
*hwc
= &event
->hw
;
1492 u64 period
, sample_period
;
1495 period
= perf_calculate_period(event
, nsec
, count
);
1497 delta
= (s64
)(period
- hwc
->sample_period
);
1498 delta
= (delta
+ 7) / 8; /* low pass filter */
1500 sample_period
= hwc
->sample_period
+ delta
;
1505 hwc
->sample_period
= sample_period
;
1507 if (atomic64_read(&hwc
->period_left
) > 8*sample_period
) {
1509 perf_event_stop(event
);
1510 atomic64_set(&hwc
->period_left
, 0);
1511 perf_event_start(event
);
1516 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
)
1518 struct perf_event
*event
;
1519 struct hw_perf_event
*hwc
;
1520 u64 interrupts
, now
;
1523 raw_spin_lock(&ctx
->lock
);
1524 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
1525 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1528 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1533 interrupts
= hwc
->interrupts
;
1534 hwc
->interrupts
= 0;
1537 * unthrottle events on the tick
1539 if (interrupts
== MAX_INTERRUPTS
) {
1540 perf_log_throttle(event
, 1);
1541 event
->pmu
->unthrottle(event
);
1544 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
1547 event
->pmu
->read(event
);
1548 now
= atomic64_read(&event
->count
);
1549 delta
= now
- hwc
->freq_count_stamp
;
1550 hwc
->freq_count_stamp
= now
;
1553 perf_adjust_period(event
, TICK_NSEC
, delta
);
1555 raw_spin_unlock(&ctx
->lock
);
1559 * Round-robin a context's events:
1561 static void rotate_ctx(struct perf_event_context
*ctx
)
1563 if (!ctx
->nr_events
)
1566 raw_spin_lock(&ctx
->lock
);
1568 /* Rotate the first entry last of non-pinned groups */
1569 list_rotate_left(&ctx
->flexible_groups
);
1571 raw_spin_unlock(&ctx
->lock
);
1574 void perf_event_task_tick(struct task_struct
*curr
)
1576 struct perf_cpu_context
*cpuctx
;
1577 struct perf_event_context
*ctx
;
1579 if (!atomic_read(&nr_events
))
1582 cpuctx
= &__get_cpu_var(perf_cpu_context
);
1583 ctx
= curr
->perf_event_ctxp
;
1587 perf_ctx_adjust_freq(&cpuctx
->ctx
);
1589 perf_ctx_adjust_freq(ctx
);
1591 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1593 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
1595 rotate_ctx(&cpuctx
->ctx
);
1599 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1601 task_ctx_sched_in(curr
, EVENT_FLEXIBLE
);
1606 static int event_enable_on_exec(struct perf_event
*event
,
1607 struct perf_event_context
*ctx
)
1609 if (!event
->attr
.enable_on_exec
)
1612 event
->attr
.enable_on_exec
= 0;
1613 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1616 __perf_event_mark_enabled(event
, ctx
);
1622 * Enable all of a task's events that have been marked enable-on-exec.
1623 * This expects task == current.
1625 static void perf_event_enable_on_exec(struct task_struct
*task
)
1627 struct perf_event_context
*ctx
;
1628 struct perf_event
*event
;
1629 unsigned long flags
;
1633 local_irq_save(flags
);
1634 ctx
= task
->perf_event_ctxp
;
1635 if (!ctx
|| !ctx
->nr_events
)
1638 __perf_event_task_sched_out(ctx
);
1640 raw_spin_lock(&ctx
->lock
);
1642 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1643 ret
= event_enable_on_exec(event
, ctx
);
1648 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1649 ret
= event_enable_on_exec(event
, ctx
);
1655 * Unclone this context if we enabled any event.
1660 raw_spin_unlock(&ctx
->lock
);
1662 perf_event_task_sched_in(task
);
1664 local_irq_restore(flags
);
1668 * Cross CPU call to read the hardware event
1670 static void __perf_event_read(void *info
)
1672 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1673 struct perf_event
*event
= info
;
1674 struct perf_event_context
*ctx
= event
->ctx
;
1677 * If this is a task context, we need to check whether it is
1678 * the current task context of this cpu. If not it has been
1679 * scheduled out before the smp call arrived. In that case
1680 * event->count would have been updated to a recent sample
1681 * when the event was scheduled out.
1683 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1686 raw_spin_lock(&ctx
->lock
);
1687 update_context_time(ctx
);
1688 update_event_times(event
);
1689 raw_spin_unlock(&ctx
->lock
);
1691 event
->pmu
->read(event
);
1694 static u64
perf_event_read(struct perf_event
*event
)
1697 * If event is enabled and currently active on a CPU, update the
1698 * value in the event structure:
1700 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1701 smp_call_function_single(event
->oncpu
,
1702 __perf_event_read
, event
, 1);
1703 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1704 struct perf_event_context
*ctx
= event
->ctx
;
1705 unsigned long flags
;
1707 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1708 update_context_time(ctx
);
1709 update_event_times(event
);
1710 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1713 return atomic64_read(&event
->count
);
1717 * Initialize the perf_event context in a task_struct:
1720 __perf_event_init_context(struct perf_event_context
*ctx
,
1721 struct task_struct
*task
)
1723 raw_spin_lock_init(&ctx
->lock
);
1724 mutex_init(&ctx
->mutex
);
1725 INIT_LIST_HEAD(&ctx
->pinned_groups
);
1726 INIT_LIST_HEAD(&ctx
->flexible_groups
);
1727 INIT_LIST_HEAD(&ctx
->event_list
);
1728 atomic_set(&ctx
->refcount
, 1);
1732 static struct perf_event_context
*find_get_context(pid_t pid
, int cpu
)
1734 struct perf_event_context
*ctx
;
1735 struct perf_cpu_context
*cpuctx
;
1736 struct task_struct
*task
;
1737 unsigned long flags
;
1740 if (pid
== -1 && cpu
!= -1) {
1741 /* Must be root to operate on a CPU event: */
1742 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
1743 return ERR_PTR(-EACCES
);
1745 if (cpu
< 0 || cpu
>= nr_cpumask_bits
)
1746 return ERR_PTR(-EINVAL
);
1749 * We could be clever and allow to attach a event to an
1750 * offline CPU and activate it when the CPU comes up, but
1753 if (!cpu_online(cpu
))
1754 return ERR_PTR(-ENODEV
);
1756 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1767 task
= find_task_by_vpid(pid
);
1769 get_task_struct(task
);
1773 return ERR_PTR(-ESRCH
);
1776 * Can't attach events to a dying task.
1779 if (task
->flags
& PF_EXITING
)
1782 /* Reuse ptrace permission checks for now. */
1784 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
1788 ctx
= perf_lock_task_context(task
, &flags
);
1791 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1795 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
1799 __perf_event_init_context(ctx
, task
);
1801 if (cmpxchg(&task
->perf_event_ctxp
, NULL
, ctx
)) {
1803 * We raced with some other task; use
1804 * the context they set.
1809 get_task_struct(task
);
1812 put_task_struct(task
);
1816 put_task_struct(task
);
1817 return ERR_PTR(err
);
1820 static void perf_event_free_filter(struct perf_event
*event
);
1822 static void free_event_rcu(struct rcu_head
*head
)
1824 struct perf_event
*event
;
1826 event
= container_of(head
, struct perf_event
, rcu_head
);
1828 put_pid_ns(event
->ns
);
1829 perf_event_free_filter(event
);
1833 static void perf_pending_sync(struct perf_event
*event
);
1835 static void free_event(struct perf_event
*event
)
1837 perf_pending_sync(event
);
1839 if (!event
->parent
) {
1840 atomic_dec(&nr_events
);
1841 if (event
->attr
.mmap
)
1842 atomic_dec(&nr_mmap_events
);
1843 if (event
->attr
.comm
)
1844 atomic_dec(&nr_comm_events
);
1845 if (event
->attr
.task
)
1846 atomic_dec(&nr_task_events
);
1849 if (event
->output
) {
1850 fput(event
->output
->filp
);
1851 event
->output
= NULL
;
1855 event
->destroy(event
);
1857 put_ctx(event
->ctx
);
1858 call_rcu(&event
->rcu_head
, free_event_rcu
);
1861 int perf_event_release_kernel(struct perf_event
*event
)
1863 struct perf_event_context
*ctx
= event
->ctx
;
1865 WARN_ON_ONCE(ctx
->parent_ctx
);
1866 mutex_lock(&ctx
->mutex
);
1867 perf_event_remove_from_context(event
);
1868 mutex_unlock(&ctx
->mutex
);
1870 mutex_lock(&event
->owner
->perf_event_mutex
);
1871 list_del_init(&event
->owner_entry
);
1872 mutex_unlock(&event
->owner
->perf_event_mutex
);
1873 put_task_struct(event
->owner
);
1879 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
1882 * Called when the last reference to the file is gone.
1884 static int perf_release(struct inode
*inode
, struct file
*file
)
1886 struct perf_event
*event
= file
->private_data
;
1888 file
->private_data
= NULL
;
1890 return perf_event_release_kernel(event
);
1893 static int perf_event_read_size(struct perf_event
*event
)
1895 int entry
= sizeof(u64
); /* value */
1899 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1900 size
+= sizeof(u64
);
1902 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1903 size
+= sizeof(u64
);
1905 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1906 entry
+= sizeof(u64
);
1908 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1909 nr
+= event
->group_leader
->nr_siblings
;
1910 size
+= sizeof(u64
);
1918 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
1920 struct perf_event
*child
;
1926 mutex_lock(&event
->child_mutex
);
1927 total
+= perf_event_read(event
);
1928 *enabled
+= event
->total_time_enabled
+
1929 atomic64_read(&event
->child_total_time_enabled
);
1930 *running
+= event
->total_time_running
+
1931 atomic64_read(&event
->child_total_time_running
);
1933 list_for_each_entry(child
, &event
->child_list
, child_list
) {
1934 total
+= perf_event_read(child
);
1935 *enabled
+= child
->total_time_enabled
;
1936 *running
+= child
->total_time_running
;
1938 mutex_unlock(&event
->child_mutex
);
1942 EXPORT_SYMBOL_GPL(perf_event_read_value
);
1944 static int perf_event_read_group(struct perf_event
*event
,
1945 u64 read_format
, char __user
*buf
)
1947 struct perf_event
*leader
= event
->group_leader
, *sub
;
1948 int n
= 0, size
= 0, ret
= -EFAULT
;
1949 struct perf_event_context
*ctx
= leader
->ctx
;
1951 u64 count
, enabled
, running
;
1953 mutex_lock(&ctx
->mutex
);
1954 count
= perf_event_read_value(leader
, &enabled
, &running
);
1956 values
[n
++] = 1 + leader
->nr_siblings
;
1957 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1958 values
[n
++] = enabled
;
1959 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1960 values
[n
++] = running
;
1961 values
[n
++] = count
;
1962 if (read_format
& PERF_FORMAT_ID
)
1963 values
[n
++] = primary_event_id(leader
);
1965 size
= n
* sizeof(u64
);
1967 if (copy_to_user(buf
, values
, size
))
1972 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
1975 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
1976 if (read_format
& PERF_FORMAT_ID
)
1977 values
[n
++] = primary_event_id(sub
);
1979 size
= n
* sizeof(u64
);
1981 if (copy_to_user(buf
+ ret
, values
, size
)) {
1989 mutex_unlock(&ctx
->mutex
);
1994 static int perf_event_read_one(struct perf_event
*event
,
1995 u64 read_format
, char __user
*buf
)
1997 u64 enabled
, running
;
2001 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
2002 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2003 values
[n
++] = enabled
;
2004 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2005 values
[n
++] = running
;
2006 if (read_format
& PERF_FORMAT_ID
)
2007 values
[n
++] = primary_event_id(event
);
2009 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2012 return n
* sizeof(u64
);
2016 * Read the performance event - simple non blocking version for now
2019 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2021 u64 read_format
= event
->attr
.read_format
;
2025 * Return end-of-file for a read on a event that is in
2026 * error state (i.e. because it was pinned but it couldn't be
2027 * scheduled on to the CPU at some point).
2029 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2032 if (count
< perf_event_read_size(event
))
2035 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2036 if (read_format
& PERF_FORMAT_GROUP
)
2037 ret
= perf_event_read_group(event
, read_format
, buf
);
2039 ret
= perf_event_read_one(event
, read_format
, buf
);
2045 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2047 struct perf_event
*event
= file
->private_data
;
2049 return perf_read_hw(event
, buf
, count
);
2052 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2054 struct perf_event
*event
= file
->private_data
;
2055 struct perf_mmap_data
*data
;
2056 unsigned int events
= POLL_HUP
;
2059 data
= rcu_dereference(event
->data
);
2061 events
= atomic_xchg(&data
->poll
, 0);
2064 poll_wait(file
, &event
->waitq
, wait
);
2069 static void perf_event_reset(struct perf_event
*event
)
2071 (void)perf_event_read(event
);
2072 atomic64_set(&event
->count
, 0);
2073 perf_event_update_userpage(event
);
2077 * Holding the top-level event's child_mutex means that any
2078 * descendant process that has inherited this event will block
2079 * in sync_child_event if it goes to exit, thus satisfying the
2080 * task existence requirements of perf_event_enable/disable.
2082 static void perf_event_for_each_child(struct perf_event
*event
,
2083 void (*func
)(struct perf_event
*))
2085 struct perf_event
*child
;
2087 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2088 mutex_lock(&event
->child_mutex
);
2090 list_for_each_entry(child
, &event
->child_list
, child_list
)
2092 mutex_unlock(&event
->child_mutex
);
2095 static void perf_event_for_each(struct perf_event
*event
,
2096 void (*func
)(struct perf_event
*))
2098 struct perf_event_context
*ctx
= event
->ctx
;
2099 struct perf_event
*sibling
;
2101 WARN_ON_ONCE(ctx
->parent_ctx
);
2102 mutex_lock(&ctx
->mutex
);
2103 event
= event
->group_leader
;
2105 perf_event_for_each_child(event
, func
);
2107 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
2108 perf_event_for_each_child(event
, func
);
2109 mutex_unlock(&ctx
->mutex
);
2112 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
2114 struct perf_event_context
*ctx
= event
->ctx
;
2119 if (!event
->attr
.sample_period
)
2122 size
= copy_from_user(&value
, arg
, sizeof(value
));
2123 if (size
!= sizeof(value
))
2129 raw_spin_lock_irq(&ctx
->lock
);
2130 if (event
->attr
.freq
) {
2131 if (value
> sysctl_perf_event_sample_rate
) {
2136 event
->attr
.sample_freq
= value
;
2138 event
->attr
.sample_period
= value
;
2139 event
->hw
.sample_period
= value
;
2142 raw_spin_unlock_irq(&ctx
->lock
);
2147 static int perf_event_set_output(struct perf_event
*event
, int output_fd
);
2148 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
2150 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2152 struct perf_event
*event
= file
->private_data
;
2153 void (*func
)(struct perf_event
*);
2157 case PERF_EVENT_IOC_ENABLE
:
2158 func
= perf_event_enable
;
2160 case PERF_EVENT_IOC_DISABLE
:
2161 func
= perf_event_disable
;
2163 case PERF_EVENT_IOC_RESET
:
2164 func
= perf_event_reset
;
2167 case PERF_EVENT_IOC_REFRESH
:
2168 return perf_event_refresh(event
, arg
);
2170 case PERF_EVENT_IOC_PERIOD
:
2171 return perf_event_period(event
, (u64 __user
*)arg
);
2173 case PERF_EVENT_IOC_SET_OUTPUT
:
2174 return perf_event_set_output(event
, arg
);
2176 case PERF_EVENT_IOC_SET_FILTER
:
2177 return perf_event_set_filter(event
, (void __user
*)arg
);
2183 if (flags
& PERF_IOC_FLAG_GROUP
)
2184 perf_event_for_each(event
, func
);
2186 perf_event_for_each_child(event
, func
);
2191 int perf_event_task_enable(void)
2193 struct perf_event
*event
;
2195 mutex_lock(¤t
->perf_event_mutex
);
2196 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2197 perf_event_for_each_child(event
, perf_event_enable
);
2198 mutex_unlock(¤t
->perf_event_mutex
);
2203 int perf_event_task_disable(void)
2205 struct perf_event
*event
;
2207 mutex_lock(¤t
->perf_event_mutex
);
2208 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2209 perf_event_for_each_child(event
, perf_event_disable
);
2210 mutex_unlock(¤t
->perf_event_mutex
);
2215 #ifndef PERF_EVENT_INDEX_OFFSET
2216 # define PERF_EVENT_INDEX_OFFSET 0
2219 static int perf_event_index(struct perf_event
*event
)
2221 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2224 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
2228 * Callers need to ensure there can be no nesting of this function, otherwise
2229 * the seqlock logic goes bad. We can not serialize this because the arch
2230 * code calls this from NMI context.
2232 void perf_event_update_userpage(struct perf_event
*event
)
2234 struct perf_event_mmap_page
*userpg
;
2235 struct perf_mmap_data
*data
;
2238 data
= rcu_dereference(event
->data
);
2242 userpg
= data
->user_page
;
2245 * Disable preemption so as to not let the corresponding user-space
2246 * spin too long if we get preempted.
2251 userpg
->index
= perf_event_index(event
);
2252 userpg
->offset
= atomic64_read(&event
->count
);
2253 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2254 userpg
->offset
-= atomic64_read(&event
->hw
.prev_count
);
2256 userpg
->time_enabled
= event
->total_time_enabled
+
2257 atomic64_read(&event
->child_total_time_enabled
);
2259 userpg
->time_running
= event
->total_time_running
+
2260 atomic64_read(&event
->child_total_time_running
);
2269 static unsigned long perf_data_size(struct perf_mmap_data
*data
)
2271 return data
->nr_pages
<< (PAGE_SHIFT
+ data
->data_order
);
2274 #ifndef CONFIG_PERF_USE_VMALLOC
2277 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
2280 static struct page
*
2281 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2283 if (pgoff
> data
->nr_pages
)
2287 return virt_to_page(data
->user_page
);
2289 return virt_to_page(data
->data_pages
[pgoff
- 1]);
2292 static struct perf_mmap_data
*
2293 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2295 struct perf_mmap_data
*data
;
2299 WARN_ON(atomic_read(&event
->mmap_count
));
2301 size
= sizeof(struct perf_mmap_data
);
2302 size
+= nr_pages
* sizeof(void *);
2304 data
= kzalloc(size
, GFP_KERNEL
);
2308 data
->user_page
= (void *)get_zeroed_page(GFP_KERNEL
);
2309 if (!data
->user_page
)
2310 goto fail_user_page
;
2312 for (i
= 0; i
< nr_pages
; i
++) {
2313 data
->data_pages
[i
] = (void *)get_zeroed_page(GFP_KERNEL
);
2314 if (!data
->data_pages
[i
])
2315 goto fail_data_pages
;
2318 data
->data_order
= 0;
2319 data
->nr_pages
= nr_pages
;
2324 for (i
--; i
>= 0; i
--)
2325 free_page((unsigned long)data
->data_pages
[i
]);
2327 free_page((unsigned long)data
->user_page
);
2336 static void perf_mmap_free_page(unsigned long addr
)
2338 struct page
*page
= virt_to_page((void *)addr
);
2340 page
->mapping
= NULL
;
2344 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2348 perf_mmap_free_page((unsigned long)data
->user_page
);
2349 for (i
= 0; i
< data
->nr_pages
; i
++)
2350 perf_mmap_free_page((unsigned long)data
->data_pages
[i
]);
2357 * Back perf_mmap() with vmalloc memory.
2359 * Required for architectures that have d-cache aliasing issues.
2362 static struct page
*
2363 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2365 if (pgoff
> (1UL << data
->data_order
))
2368 return vmalloc_to_page((void *)data
->user_page
+ pgoff
* PAGE_SIZE
);
2371 static void perf_mmap_unmark_page(void *addr
)
2373 struct page
*page
= vmalloc_to_page(addr
);
2375 page
->mapping
= NULL
;
2378 static void perf_mmap_data_free_work(struct work_struct
*work
)
2380 struct perf_mmap_data
*data
;
2384 data
= container_of(work
, struct perf_mmap_data
, work
);
2385 nr
= 1 << data
->data_order
;
2387 base
= data
->user_page
;
2388 for (i
= 0; i
< nr
+ 1; i
++)
2389 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
2395 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2397 schedule_work(&data
->work
);
2400 static struct perf_mmap_data
*
2401 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2403 struct perf_mmap_data
*data
;
2407 WARN_ON(atomic_read(&event
->mmap_count
));
2409 size
= sizeof(struct perf_mmap_data
);
2410 size
+= sizeof(void *);
2412 data
= kzalloc(size
, GFP_KERNEL
);
2416 INIT_WORK(&data
->work
, perf_mmap_data_free_work
);
2418 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
2422 data
->user_page
= all_buf
;
2423 data
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
2424 data
->data_order
= ilog2(nr_pages
);
2438 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
2440 struct perf_event
*event
= vma
->vm_file
->private_data
;
2441 struct perf_mmap_data
*data
;
2442 int ret
= VM_FAULT_SIGBUS
;
2444 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
2445 if (vmf
->pgoff
== 0)
2451 data
= rcu_dereference(event
->data
);
2455 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
2458 vmf
->page
= perf_mmap_to_page(data
, vmf
->pgoff
);
2462 get_page(vmf
->page
);
2463 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
2464 vmf
->page
->index
= vmf
->pgoff
;
2474 perf_mmap_data_init(struct perf_event
*event
, struct perf_mmap_data
*data
)
2476 long max_size
= perf_data_size(data
);
2478 atomic_set(&data
->lock
, -1);
2480 if (event
->attr
.watermark
) {
2481 data
->watermark
= min_t(long, max_size
,
2482 event
->attr
.wakeup_watermark
);
2485 if (!data
->watermark
)
2486 data
->watermark
= max_size
/ 2;
2489 rcu_assign_pointer(event
->data
, data
);
2492 static void perf_mmap_data_free_rcu(struct rcu_head
*rcu_head
)
2494 struct perf_mmap_data
*data
;
2496 data
= container_of(rcu_head
, struct perf_mmap_data
, rcu_head
);
2497 perf_mmap_data_free(data
);
2500 static void perf_mmap_data_release(struct perf_event
*event
)
2502 struct perf_mmap_data
*data
= event
->data
;
2504 WARN_ON(atomic_read(&event
->mmap_count
));
2506 rcu_assign_pointer(event
->data
, NULL
);
2507 call_rcu(&data
->rcu_head
, perf_mmap_data_free_rcu
);
2510 static void perf_mmap_open(struct vm_area_struct
*vma
)
2512 struct perf_event
*event
= vma
->vm_file
->private_data
;
2514 atomic_inc(&event
->mmap_count
);
2517 static void perf_mmap_close(struct vm_area_struct
*vma
)
2519 struct perf_event
*event
= vma
->vm_file
->private_data
;
2521 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2522 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
2523 unsigned long size
= perf_data_size(event
->data
);
2524 struct user_struct
*user
= current_user();
2526 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
2527 vma
->vm_mm
->locked_vm
-= event
->data
->nr_locked
;
2528 perf_mmap_data_release(event
);
2529 mutex_unlock(&event
->mmap_mutex
);
2533 static const struct vm_operations_struct perf_mmap_vmops
= {
2534 .open
= perf_mmap_open
,
2535 .close
= perf_mmap_close
,
2536 .fault
= perf_mmap_fault
,
2537 .page_mkwrite
= perf_mmap_fault
,
2540 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
2542 struct perf_event
*event
= file
->private_data
;
2543 unsigned long user_locked
, user_lock_limit
;
2544 struct user_struct
*user
= current_user();
2545 unsigned long locked
, lock_limit
;
2546 struct perf_mmap_data
*data
;
2547 unsigned long vma_size
;
2548 unsigned long nr_pages
;
2549 long user_extra
, extra
;
2552 if (!(vma
->vm_flags
& VM_SHARED
))
2555 vma_size
= vma
->vm_end
- vma
->vm_start
;
2556 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
2559 * If we have data pages ensure they're a power-of-two number, so we
2560 * can do bitmasks instead of modulo.
2562 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
2565 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
2568 if (vma
->vm_pgoff
!= 0)
2571 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2572 mutex_lock(&event
->mmap_mutex
);
2573 if (event
->output
) {
2578 if (atomic_inc_not_zero(&event
->mmap_count
)) {
2579 if (nr_pages
!= event
->data
->nr_pages
)
2584 user_extra
= nr_pages
+ 1;
2585 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
2588 * Increase the limit linearly with more CPUs:
2590 user_lock_limit
*= num_online_cpus();
2592 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
2595 if (user_locked
> user_lock_limit
)
2596 extra
= user_locked
- user_lock_limit
;
2598 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
2599 lock_limit
>>= PAGE_SHIFT
;
2600 locked
= vma
->vm_mm
->locked_vm
+ extra
;
2602 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
2603 !capable(CAP_IPC_LOCK
)) {
2608 WARN_ON(event
->data
);
2610 data
= perf_mmap_data_alloc(event
, nr_pages
);
2616 perf_mmap_data_init(event
, data
);
2618 atomic_set(&event
->mmap_count
, 1);
2619 atomic_long_add(user_extra
, &user
->locked_vm
);
2620 vma
->vm_mm
->locked_vm
+= extra
;
2621 event
->data
->nr_locked
= extra
;
2622 if (vma
->vm_flags
& VM_WRITE
)
2623 event
->data
->writable
= 1;
2626 mutex_unlock(&event
->mmap_mutex
);
2628 vma
->vm_flags
|= VM_RESERVED
;
2629 vma
->vm_ops
= &perf_mmap_vmops
;
2634 static int perf_fasync(int fd
, struct file
*filp
, int on
)
2636 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
2637 struct perf_event
*event
= filp
->private_data
;
2640 mutex_lock(&inode
->i_mutex
);
2641 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
2642 mutex_unlock(&inode
->i_mutex
);
2650 static const struct file_operations perf_fops
= {
2651 .release
= perf_release
,
2654 .unlocked_ioctl
= perf_ioctl
,
2655 .compat_ioctl
= perf_ioctl
,
2657 .fasync
= perf_fasync
,
2663 * If there's data, ensure we set the poll() state and publish everything
2664 * to user-space before waking everybody up.
2667 void perf_event_wakeup(struct perf_event
*event
)
2669 wake_up_all(&event
->waitq
);
2671 if (event
->pending_kill
) {
2672 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
2673 event
->pending_kill
= 0;
2680 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
2682 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
2683 * single linked list and use cmpxchg() to add entries lockless.
2686 static void perf_pending_event(struct perf_pending_entry
*entry
)
2688 struct perf_event
*event
= container_of(entry
,
2689 struct perf_event
, pending
);
2691 if (event
->pending_disable
) {
2692 event
->pending_disable
= 0;
2693 __perf_event_disable(event
);
2696 if (event
->pending_wakeup
) {
2697 event
->pending_wakeup
= 0;
2698 perf_event_wakeup(event
);
2702 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
2704 static DEFINE_PER_CPU(struct perf_pending_entry
*, perf_pending_head
) = {
2708 static void perf_pending_queue(struct perf_pending_entry
*entry
,
2709 void (*func
)(struct perf_pending_entry
*))
2711 struct perf_pending_entry
**head
;
2713 if (cmpxchg(&entry
->next
, NULL
, PENDING_TAIL
) != NULL
)
2718 head
= &get_cpu_var(perf_pending_head
);
2721 entry
->next
= *head
;
2722 } while (cmpxchg(head
, entry
->next
, entry
) != entry
->next
);
2724 set_perf_event_pending();
2726 put_cpu_var(perf_pending_head
);
2729 static int __perf_pending_run(void)
2731 struct perf_pending_entry
*list
;
2734 list
= xchg(&__get_cpu_var(perf_pending_head
), PENDING_TAIL
);
2735 while (list
!= PENDING_TAIL
) {
2736 void (*func
)(struct perf_pending_entry
*);
2737 struct perf_pending_entry
*entry
= list
;
2744 * Ensure we observe the unqueue before we issue the wakeup,
2745 * so that we won't be waiting forever.
2746 * -- see perf_not_pending().
2757 static inline int perf_not_pending(struct perf_event
*event
)
2760 * If we flush on whatever cpu we run, there is a chance we don't
2764 __perf_pending_run();
2768 * Ensure we see the proper queue state before going to sleep
2769 * so that we do not miss the wakeup. -- see perf_pending_handle()
2772 return event
->pending
.next
== NULL
;
2775 static void perf_pending_sync(struct perf_event
*event
)
2777 wait_event(event
->waitq
, perf_not_pending(event
));
2780 void perf_event_do_pending(void)
2782 __perf_pending_run();
2786 * Callchain support -- arch specific
2789 __weak
struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2797 static bool perf_output_space(struct perf_mmap_data
*data
, unsigned long tail
,
2798 unsigned long offset
, unsigned long head
)
2802 if (!data
->writable
)
2805 mask
= perf_data_size(data
) - 1;
2807 offset
= (offset
- tail
) & mask
;
2808 head
= (head
- tail
) & mask
;
2810 if ((int)(head
- offset
) < 0)
2816 static void perf_output_wakeup(struct perf_output_handle
*handle
)
2818 atomic_set(&handle
->data
->poll
, POLL_IN
);
2821 handle
->event
->pending_wakeup
= 1;
2822 perf_pending_queue(&handle
->event
->pending
,
2823 perf_pending_event
);
2825 perf_event_wakeup(handle
->event
);
2829 * Curious locking construct.
2831 * We need to ensure a later event_id doesn't publish a head when a former
2832 * event_id isn't done writing. However since we need to deal with NMIs we
2833 * cannot fully serialize things.
2835 * What we do is serialize between CPUs so we only have to deal with NMI
2836 * nesting on a single CPU.
2838 * We only publish the head (and generate a wakeup) when the outer-most
2839 * event_id completes.
2841 static void perf_output_lock(struct perf_output_handle
*handle
)
2843 struct perf_mmap_data
*data
= handle
->data
;
2844 int cur
, cpu
= get_cpu();
2849 cur
= atomic_cmpxchg(&data
->lock
, -1, cpu
);
2861 static void perf_output_unlock(struct perf_output_handle
*handle
)
2863 struct perf_mmap_data
*data
= handle
->data
;
2867 data
->done_head
= data
->head
;
2869 if (!handle
->locked
)
2874 * The xchg implies a full barrier that ensures all writes are done
2875 * before we publish the new head, matched by a rmb() in userspace when
2876 * reading this position.
2878 while ((head
= atomic_long_xchg(&data
->done_head
, 0)))
2879 data
->user_page
->data_head
= head
;
2882 * NMI can happen here, which means we can miss a done_head update.
2885 cpu
= atomic_xchg(&data
->lock
, -1);
2886 WARN_ON_ONCE(cpu
!= smp_processor_id());
2889 * Therefore we have to validate we did not indeed do so.
2891 if (unlikely(atomic_long_read(&data
->done_head
))) {
2893 * Since we had it locked, we can lock it again.
2895 while (atomic_cmpxchg(&data
->lock
, -1, cpu
) != -1)
2901 if (atomic_xchg(&data
->wakeup
, 0))
2902 perf_output_wakeup(handle
);
2907 void perf_output_copy(struct perf_output_handle
*handle
,
2908 const void *buf
, unsigned int len
)
2910 unsigned int pages_mask
;
2911 unsigned long offset
;
2915 offset
= handle
->offset
;
2916 pages_mask
= handle
->data
->nr_pages
- 1;
2917 pages
= handle
->data
->data_pages
;
2920 unsigned long page_offset
;
2921 unsigned long page_size
;
2924 nr
= (offset
>> PAGE_SHIFT
) & pages_mask
;
2925 page_size
= 1UL << (handle
->data
->data_order
+ PAGE_SHIFT
);
2926 page_offset
= offset
& (page_size
- 1);
2927 size
= min_t(unsigned int, page_size
- page_offset
, len
);
2929 memcpy(pages
[nr
] + page_offset
, buf
, size
);
2936 handle
->offset
= offset
;
2939 * Check we didn't copy past our reservation window, taking the
2940 * possible unsigned int wrap into account.
2942 WARN_ON_ONCE(((long)(handle
->head
- handle
->offset
)) < 0);
2945 int perf_output_begin(struct perf_output_handle
*handle
,
2946 struct perf_event
*event
, unsigned int size
,
2947 int nmi
, int sample
)
2949 struct perf_event
*output_event
;
2950 struct perf_mmap_data
*data
;
2951 unsigned long tail
, offset
, head
;
2954 struct perf_event_header header
;
2961 * For inherited events we send all the output towards the parent.
2964 event
= event
->parent
;
2966 output_event
= rcu_dereference(event
->output
);
2968 event
= output_event
;
2970 data
= rcu_dereference(event
->data
);
2974 handle
->data
= data
;
2975 handle
->event
= event
;
2977 handle
->sample
= sample
;
2979 if (!data
->nr_pages
)
2982 have_lost
= atomic_read(&data
->lost
);
2984 size
+= sizeof(lost_event
);
2986 perf_output_lock(handle
);
2990 * Userspace could choose to issue a mb() before updating the
2991 * tail pointer. So that all reads will be completed before the
2994 tail
= ACCESS_ONCE(data
->user_page
->data_tail
);
2996 offset
= head
= atomic_long_read(&data
->head
);
2998 if (unlikely(!perf_output_space(data
, tail
, offset
, head
)))
3000 } while (atomic_long_cmpxchg(&data
->head
, offset
, head
) != offset
);
3002 handle
->offset
= offset
;
3003 handle
->head
= head
;
3005 if (head
- tail
> data
->watermark
)
3006 atomic_set(&data
->wakeup
, 1);
3009 lost_event
.header
.type
= PERF_RECORD_LOST
;
3010 lost_event
.header
.misc
= 0;
3011 lost_event
.header
.size
= sizeof(lost_event
);
3012 lost_event
.id
= event
->id
;
3013 lost_event
.lost
= atomic_xchg(&data
->lost
, 0);
3015 perf_output_put(handle
, lost_event
);
3021 atomic_inc(&data
->lost
);
3022 perf_output_unlock(handle
);
3029 void perf_output_end(struct perf_output_handle
*handle
)
3031 struct perf_event
*event
= handle
->event
;
3032 struct perf_mmap_data
*data
= handle
->data
;
3034 int wakeup_events
= event
->attr
.wakeup_events
;
3036 if (handle
->sample
&& wakeup_events
) {
3037 int events
= atomic_inc_return(&data
->events
);
3038 if (events
>= wakeup_events
) {
3039 atomic_sub(wakeup_events
, &data
->events
);
3040 atomic_set(&data
->wakeup
, 1);
3044 perf_output_unlock(handle
);
3048 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
3051 * only top level events have the pid namespace they were created in
3054 event
= event
->parent
;
3056 return task_tgid_nr_ns(p
, event
->ns
);
3059 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
3062 * only top level events have the pid namespace they were created in
3065 event
= event
->parent
;
3067 return task_pid_nr_ns(p
, event
->ns
);
3070 static void perf_output_read_one(struct perf_output_handle
*handle
,
3071 struct perf_event
*event
)
3073 u64 read_format
= event
->attr
.read_format
;
3077 values
[n
++] = atomic64_read(&event
->count
);
3078 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3079 values
[n
++] = event
->total_time_enabled
+
3080 atomic64_read(&event
->child_total_time_enabled
);
3082 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3083 values
[n
++] = event
->total_time_running
+
3084 atomic64_read(&event
->child_total_time_running
);
3086 if (read_format
& PERF_FORMAT_ID
)
3087 values
[n
++] = primary_event_id(event
);
3089 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3093 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3095 static void perf_output_read_group(struct perf_output_handle
*handle
,
3096 struct perf_event
*event
)
3098 struct perf_event
*leader
= event
->group_leader
, *sub
;
3099 u64 read_format
= event
->attr
.read_format
;
3103 values
[n
++] = 1 + leader
->nr_siblings
;
3105 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3106 values
[n
++] = leader
->total_time_enabled
;
3108 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3109 values
[n
++] = leader
->total_time_running
;
3111 if (leader
!= event
)
3112 leader
->pmu
->read(leader
);
3114 values
[n
++] = atomic64_read(&leader
->count
);
3115 if (read_format
& PERF_FORMAT_ID
)
3116 values
[n
++] = primary_event_id(leader
);
3118 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3120 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3124 sub
->pmu
->read(sub
);
3126 values
[n
++] = atomic64_read(&sub
->count
);
3127 if (read_format
& PERF_FORMAT_ID
)
3128 values
[n
++] = primary_event_id(sub
);
3130 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3134 static void perf_output_read(struct perf_output_handle
*handle
,
3135 struct perf_event
*event
)
3137 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3138 perf_output_read_group(handle
, event
);
3140 perf_output_read_one(handle
, event
);
3143 void perf_output_sample(struct perf_output_handle
*handle
,
3144 struct perf_event_header
*header
,
3145 struct perf_sample_data
*data
,
3146 struct perf_event
*event
)
3148 u64 sample_type
= data
->type
;
3150 perf_output_put(handle
, *header
);
3152 if (sample_type
& PERF_SAMPLE_IP
)
3153 perf_output_put(handle
, data
->ip
);
3155 if (sample_type
& PERF_SAMPLE_TID
)
3156 perf_output_put(handle
, data
->tid_entry
);
3158 if (sample_type
& PERF_SAMPLE_TIME
)
3159 perf_output_put(handle
, data
->time
);
3161 if (sample_type
& PERF_SAMPLE_ADDR
)
3162 perf_output_put(handle
, data
->addr
);
3164 if (sample_type
& PERF_SAMPLE_ID
)
3165 perf_output_put(handle
, data
->id
);
3167 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3168 perf_output_put(handle
, data
->stream_id
);
3170 if (sample_type
& PERF_SAMPLE_CPU
)
3171 perf_output_put(handle
, data
->cpu_entry
);
3173 if (sample_type
& PERF_SAMPLE_PERIOD
)
3174 perf_output_put(handle
, data
->period
);
3176 if (sample_type
& PERF_SAMPLE_READ
)
3177 perf_output_read(handle
, event
);
3179 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3180 if (data
->callchain
) {
3183 if (data
->callchain
)
3184 size
+= data
->callchain
->nr
;
3186 size
*= sizeof(u64
);
3188 perf_output_copy(handle
, data
->callchain
, size
);
3191 perf_output_put(handle
, nr
);
3195 if (sample_type
& PERF_SAMPLE_RAW
) {
3197 perf_output_put(handle
, data
->raw
->size
);
3198 perf_output_copy(handle
, data
->raw
->data
,
3205 .size
= sizeof(u32
),
3208 perf_output_put(handle
, raw
);
3213 void perf_prepare_sample(struct perf_event_header
*header
,
3214 struct perf_sample_data
*data
,
3215 struct perf_event
*event
,
3216 struct pt_regs
*regs
)
3218 u64 sample_type
= event
->attr
.sample_type
;
3220 data
->type
= sample_type
;
3222 header
->type
= PERF_RECORD_SAMPLE
;
3223 header
->size
= sizeof(*header
);
3226 header
->misc
|= perf_misc_flags(regs
);
3228 if (sample_type
& PERF_SAMPLE_IP
) {
3229 data
->ip
= perf_instruction_pointer(regs
);
3231 header
->size
+= sizeof(data
->ip
);
3234 if (sample_type
& PERF_SAMPLE_TID
) {
3235 /* namespace issues */
3236 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3237 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3239 header
->size
+= sizeof(data
->tid_entry
);
3242 if (sample_type
& PERF_SAMPLE_TIME
) {
3243 data
->time
= perf_clock();
3245 header
->size
+= sizeof(data
->time
);
3248 if (sample_type
& PERF_SAMPLE_ADDR
)
3249 header
->size
+= sizeof(data
->addr
);
3251 if (sample_type
& PERF_SAMPLE_ID
) {
3252 data
->id
= primary_event_id(event
);
3254 header
->size
+= sizeof(data
->id
);
3257 if (sample_type
& PERF_SAMPLE_STREAM_ID
) {
3258 data
->stream_id
= event
->id
;
3260 header
->size
+= sizeof(data
->stream_id
);
3263 if (sample_type
& PERF_SAMPLE_CPU
) {
3264 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3265 data
->cpu_entry
.reserved
= 0;
3267 header
->size
+= sizeof(data
->cpu_entry
);
3270 if (sample_type
& PERF_SAMPLE_PERIOD
)
3271 header
->size
+= sizeof(data
->period
);
3273 if (sample_type
& PERF_SAMPLE_READ
)
3274 header
->size
+= perf_event_read_size(event
);
3276 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3279 data
->callchain
= perf_callchain(regs
);
3281 if (data
->callchain
)
3282 size
+= data
->callchain
->nr
;
3284 header
->size
+= size
* sizeof(u64
);
3287 if (sample_type
& PERF_SAMPLE_RAW
) {
3288 int size
= sizeof(u32
);
3291 size
+= data
->raw
->size
;
3293 size
+= sizeof(u32
);
3295 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3296 header
->size
+= size
;
3300 static void perf_event_output(struct perf_event
*event
, int nmi
,
3301 struct perf_sample_data
*data
,
3302 struct pt_regs
*regs
)
3304 struct perf_output_handle handle
;
3305 struct perf_event_header header
;
3307 perf_prepare_sample(&header
, data
, event
, regs
);
3309 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
3312 perf_output_sample(&handle
, &header
, data
, event
);
3314 perf_output_end(&handle
);
3321 struct perf_read_event
{
3322 struct perf_event_header header
;
3329 perf_event_read_event(struct perf_event
*event
,
3330 struct task_struct
*task
)
3332 struct perf_output_handle handle
;
3333 struct perf_read_event read_event
= {
3335 .type
= PERF_RECORD_READ
,
3337 .size
= sizeof(read_event
) + perf_event_read_size(event
),
3339 .pid
= perf_event_pid(event
, task
),
3340 .tid
= perf_event_tid(event
, task
),
3344 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
3348 perf_output_put(&handle
, read_event
);
3349 perf_output_read(&handle
, event
);
3351 perf_output_end(&handle
);
3355 * task tracking -- fork/exit
3357 * enabled by: attr.comm | attr.mmap | attr.task
3360 struct perf_task_event
{
3361 struct task_struct
*task
;
3362 struct perf_event_context
*task_ctx
;
3365 struct perf_event_header header
;
3375 static void perf_event_task_output(struct perf_event
*event
,
3376 struct perf_task_event
*task_event
)
3378 struct perf_output_handle handle
;
3380 struct task_struct
*task
= task_event
->task
;
3383 size
= task_event
->event_id
.header
.size
;
3384 ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3389 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
3390 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
3392 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
3393 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
3395 perf_output_put(&handle
, task_event
->event_id
);
3397 perf_output_end(&handle
);
3400 static int perf_event_task_match(struct perf_event
*event
)
3402 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3405 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3408 if (event
->attr
.comm
|| event
->attr
.mmap
|| event
->attr
.task
)
3414 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
3415 struct perf_task_event
*task_event
)
3417 struct perf_event
*event
;
3419 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3420 if (perf_event_task_match(event
))
3421 perf_event_task_output(event
, task_event
);
3425 static void perf_event_task_event(struct perf_task_event
*task_event
)
3427 struct perf_cpu_context
*cpuctx
;
3428 struct perf_event_context
*ctx
= task_event
->task_ctx
;
3431 cpuctx
= &get_cpu_var(perf_cpu_context
);
3432 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
3434 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3436 perf_event_task_ctx(ctx
, task_event
);
3437 put_cpu_var(perf_cpu_context
);
3441 static void perf_event_task(struct task_struct
*task
,
3442 struct perf_event_context
*task_ctx
,
3445 struct perf_task_event task_event
;
3447 if (!atomic_read(&nr_comm_events
) &&
3448 !atomic_read(&nr_mmap_events
) &&
3449 !atomic_read(&nr_task_events
))
3452 task_event
= (struct perf_task_event
){
3454 .task_ctx
= task_ctx
,
3457 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
3459 .size
= sizeof(task_event
.event_id
),
3465 .time
= perf_clock(),
3469 perf_event_task_event(&task_event
);
3472 void perf_event_fork(struct task_struct
*task
)
3474 perf_event_task(task
, NULL
, 1);
3481 struct perf_comm_event
{
3482 struct task_struct
*task
;
3487 struct perf_event_header header
;
3494 static void perf_event_comm_output(struct perf_event
*event
,
3495 struct perf_comm_event
*comm_event
)
3497 struct perf_output_handle handle
;
3498 int size
= comm_event
->event_id
.header
.size
;
3499 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3504 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
3505 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
3507 perf_output_put(&handle
, comm_event
->event_id
);
3508 perf_output_copy(&handle
, comm_event
->comm
,
3509 comm_event
->comm_size
);
3510 perf_output_end(&handle
);
3513 static int perf_event_comm_match(struct perf_event
*event
)
3515 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3518 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3521 if (event
->attr
.comm
)
3527 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
3528 struct perf_comm_event
*comm_event
)
3530 struct perf_event
*event
;
3532 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3533 if (perf_event_comm_match(event
))
3534 perf_event_comm_output(event
, comm_event
);
3538 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
3540 struct perf_cpu_context
*cpuctx
;
3541 struct perf_event_context
*ctx
;
3543 char comm
[TASK_COMM_LEN
];
3545 memset(comm
, 0, sizeof(comm
));
3546 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
3547 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
3549 comm_event
->comm
= comm
;
3550 comm_event
->comm_size
= size
;
3552 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
3555 cpuctx
= &get_cpu_var(perf_cpu_context
);
3556 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
3557 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3559 perf_event_comm_ctx(ctx
, comm_event
);
3560 put_cpu_var(perf_cpu_context
);
3564 void perf_event_comm(struct task_struct
*task
)
3566 struct perf_comm_event comm_event
;
3568 if (task
->perf_event_ctxp
)
3569 perf_event_enable_on_exec(task
);
3571 if (!atomic_read(&nr_comm_events
))
3574 comm_event
= (struct perf_comm_event
){
3580 .type
= PERF_RECORD_COMM
,
3589 perf_event_comm_event(&comm_event
);
3596 struct perf_mmap_event
{
3597 struct vm_area_struct
*vma
;
3599 const char *file_name
;
3603 struct perf_event_header header
;
3613 static void perf_event_mmap_output(struct perf_event
*event
,
3614 struct perf_mmap_event
*mmap_event
)
3616 struct perf_output_handle handle
;
3617 int size
= mmap_event
->event_id
.header
.size
;
3618 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3623 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
3624 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
3626 perf_output_put(&handle
, mmap_event
->event_id
);
3627 perf_output_copy(&handle
, mmap_event
->file_name
,
3628 mmap_event
->file_size
);
3629 perf_output_end(&handle
);
3632 static int perf_event_mmap_match(struct perf_event
*event
,
3633 struct perf_mmap_event
*mmap_event
)
3635 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3638 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3641 if (event
->attr
.mmap
)
3647 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
3648 struct perf_mmap_event
*mmap_event
)
3650 struct perf_event
*event
;
3652 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3653 if (perf_event_mmap_match(event
, mmap_event
))
3654 perf_event_mmap_output(event
, mmap_event
);
3658 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
3660 struct perf_cpu_context
*cpuctx
;
3661 struct perf_event_context
*ctx
;
3662 struct vm_area_struct
*vma
= mmap_event
->vma
;
3663 struct file
*file
= vma
->vm_file
;
3669 memset(tmp
, 0, sizeof(tmp
));
3673 * d_path works from the end of the buffer backwards, so we
3674 * need to add enough zero bytes after the string to handle
3675 * the 64bit alignment we do later.
3677 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
3679 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
3682 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
3684 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
3688 if (arch_vma_name(mmap_event
->vma
)) {
3689 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
3695 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
3699 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
3704 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
3706 mmap_event
->file_name
= name
;
3707 mmap_event
->file_size
= size
;
3709 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
3712 cpuctx
= &get_cpu_var(perf_cpu_context
);
3713 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
);
3714 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3716 perf_event_mmap_ctx(ctx
, mmap_event
);
3717 put_cpu_var(perf_cpu_context
);
3723 void __perf_event_mmap(struct vm_area_struct
*vma
)
3725 struct perf_mmap_event mmap_event
;
3727 if (!atomic_read(&nr_mmap_events
))
3730 mmap_event
= (struct perf_mmap_event
){
3736 .type
= PERF_RECORD_MMAP
,
3742 .start
= vma
->vm_start
,
3743 .len
= vma
->vm_end
- vma
->vm_start
,
3744 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
3748 perf_event_mmap_event(&mmap_event
);
3752 * IRQ throttle logging
3755 static void perf_log_throttle(struct perf_event
*event
, int enable
)
3757 struct perf_output_handle handle
;
3761 struct perf_event_header header
;
3765 } throttle_event
= {
3767 .type
= PERF_RECORD_THROTTLE
,
3769 .size
= sizeof(throttle_event
),
3771 .time
= perf_clock(),
3772 .id
= primary_event_id(event
),
3773 .stream_id
= event
->id
,
3777 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
3779 ret
= perf_output_begin(&handle
, event
, sizeof(throttle_event
), 1, 0);
3783 perf_output_put(&handle
, throttle_event
);
3784 perf_output_end(&handle
);
3788 * Generic event overflow handling, sampling.
3791 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
3792 int throttle
, struct perf_sample_data
*data
,
3793 struct pt_regs
*regs
)
3795 int events
= atomic_read(&event
->event_limit
);
3796 struct hw_perf_event
*hwc
= &event
->hw
;
3799 throttle
= (throttle
&& event
->pmu
->unthrottle
!= NULL
);
3804 if (hwc
->interrupts
!= MAX_INTERRUPTS
) {
3806 if (HZ
* hwc
->interrupts
>
3807 (u64
)sysctl_perf_event_sample_rate
) {
3808 hwc
->interrupts
= MAX_INTERRUPTS
;
3809 perf_log_throttle(event
, 0);
3814 * Keep re-disabling events even though on the previous
3815 * pass we disabled it - just in case we raced with a
3816 * sched-in and the event got enabled again:
3822 if (event
->attr
.freq
) {
3823 u64 now
= perf_clock();
3824 s64 delta
= now
- hwc
->freq_time_stamp
;
3826 hwc
->freq_time_stamp
= now
;
3828 if (delta
> 0 && delta
< 2*TICK_NSEC
)
3829 perf_adjust_period(event
, delta
, hwc
->last_period
);
3833 * XXX event_limit might not quite work as expected on inherited
3837 event
->pending_kill
= POLL_IN
;
3838 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
3840 event
->pending_kill
= POLL_HUP
;
3842 event
->pending_disable
= 1;
3843 perf_pending_queue(&event
->pending
,
3844 perf_pending_event
);
3846 perf_event_disable(event
);
3849 if (event
->overflow_handler
)
3850 event
->overflow_handler(event
, nmi
, data
, regs
);
3852 perf_event_output(event
, nmi
, data
, regs
);
3857 int perf_event_overflow(struct perf_event
*event
, int nmi
,
3858 struct perf_sample_data
*data
,
3859 struct pt_regs
*regs
)
3861 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
3865 * Generic software event infrastructure
3869 * We directly increment event->count and keep a second value in
3870 * event->hw.period_left to count intervals. This period event
3871 * is kept in the range [-sample_period, 0] so that we can use the
3875 static u64
perf_swevent_set_period(struct perf_event
*event
)
3877 struct hw_perf_event
*hwc
= &event
->hw
;
3878 u64 period
= hwc
->last_period
;
3882 hwc
->last_period
= hwc
->sample_period
;
3885 old
= val
= atomic64_read(&hwc
->period_left
);
3889 nr
= div64_u64(period
+ val
, period
);
3890 offset
= nr
* period
;
3892 if (atomic64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
3898 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
3899 int nmi
, struct perf_sample_data
*data
,
3900 struct pt_regs
*regs
)
3902 struct hw_perf_event
*hwc
= &event
->hw
;
3905 data
->period
= event
->hw
.last_period
;
3907 overflow
= perf_swevent_set_period(event
);
3909 if (hwc
->interrupts
== MAX_INTERRUPTS
)
3912 for (; overflow
; overflow
--) {
3913 if (__perf_event_overflow(event
, nmi
, throttle
,
3916 * We inhibit the overflow from happening when
3917 * hwc->interrupts == MAX_INTERRUPTS.
3925 static void perf_swevent_unthrottle(struct perf_event
*event
)
3928 * Nothing to do, we already reset hwc->interrupts.
3932 static void perf_swevent_add(struct perf_event
*event
, u64 nr
,
3933 int nmi
, struct perf_sample_data
*data
,
3934 struct pt_regs
*regs
)
3936 struct hw_perf_event
*hwc
= &event
->hw
;
3938 atomic64_add(nr
, &event
->count
);
3943 if (!hwc
->sample_period
)
3946 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
3947 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
3949 if (atomic64_add_negative(nr
, &hwc
->period_left
))
3952 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
3955 static int perf_swevent_is_counting(struct perf_event
*event
)
3958 * The event is active, we're good!
3960 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3964 * The event is off/error, not counting.
3966 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
)
3970 * The event is inactive, if the context is active
3971 * we're part of a group that didn't make it on the 'pmu',
3974 if (event
->ctx
->is_active
)
3978 * We're inactive and the context is too, this means the
3979 * task is scheduled out, we're counting events that happen
3980 * to us, like migration events.
3985 static int perf_tp_event_match(struct perf_event
*event
,
3986 struct perf_sample_data
*data
);
3988 static int perf_exclude_event(struct perf_event
*event
,
3989 struct pt_regs
*regs
)
3992 if (event
->attr
.exclude_user
&& user_mode(regs
))
3995 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4002 static int perf_swevent_match(struct perf_event
*event
,
4003 enum perf_type_id type
,
4005 struct perf_sample_data
*data
,
4006 struct pt_regs
*regs
)
4008 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
4011 if (!perf_swevent_is_counting(event
))
4014 if (event
->attr
.type
!= type
)
4017 if (event
->attr
.config
!= event_id
)
4020 if (perf_exclude_event(event
, regs
))
4023 if (event
->attr
.type
== PERF_TYPE_TRACEPOINT
&&
4024 !perf_tp_event_match(event
, data
))
4030 static void perf_swevent_ctx_event(struct perf_event_context
*ctx
,
4031 enum perf_type_id type
,
4032 u32 event_id
, u64 nr
, int nmi
,
4033 struct perf_sample_data
*data
,
4034 struct pt_regs
*regs
)
4036 struct perf_event
*event
;
4038 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4039 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4040 perf_swevent_add(event
, nr
, nmi
, data
, regs
);
4044 int perf_swevent_get_recursion_context(void)
4046 struct perf_cpu_context
*cpuctx
= &get_cpu_var(perf_cpu_context
);
4053 else if (in_softirq())
4058 if (cpuctx
->recursion
[rctx
]) {
4059 put_cpu_var(perf_cpu_context
);
4063 cpuctx
->recursion
[rctx
]++;
4068 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4070 void perf_swevent_put_recursion_context(int rctx
)
4072 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
4074 cpuctx
->recursion
[rctx
]--;
4075 put_cpu_var(perf_cpu_context
);
4077 EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context
);
4079 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4081 struct perf_sample_data
*data
,
4082 struct pt_regs
*regs
)
4084 struct perf_cpu_context
*cpuctx
;
4085 struct perf_event_context
*ctx
;
4087 cpuctx
= &__get_cpu_var(perf_cpu_context
);
4089 perf_swevent_ctx_event(&cpuctx
->ctx
, type
, event_id
,
4090 nr
, nmi
, data
, regs
);
4092 * doesn't really matter which of the child contexts the
4093 * events ends up in.
4095 ctx
= rcu_dereference(current
->perf_event_ctxp
);
4097 perf_swevent_ctx_event(ctx
, type
, event_id
, nr
, nmi
, data
, regs
);
4101 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
4102 struct pt_regs
*regs
, u64 addr
)
4104 struct perf_sample_data data
;
4107 rctx
= perf_swevent_get_recursion_context();
4111 perf_sample_data_init(&data
, addr
);
4113 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
4115 perf_swevent_put_recursion_context(rctx
);
4118 static void perf_swevent_read(struct perf_event
*event
)
4122 static int perf_swevent_enable(struct perf_event
*event
)
4124 struct hw_perf_event
*hwc
= &event
->hw
;
4126 if (hwc
->sample_period
) {
4127 hwc
->last_period
= hwc
->sample_period
;
4128 perf_swevent_set_period(event
);
4133 static void perf_swevent_disable(struct perf_event
*event
)
4137 static const struct pmu perf_ops_generic
= {
4138 .enable
= perf_swevent_enable
,
4139 .disable
= perf_swevent_disable
,
4140 .read
= perf_swevent_read
,
4141 .unthrottle
= perf_swevent_unthrottle
,
4145 * hrtimer based swevent callback
4148 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
4150 enum hrtimer_restart ret
= HRTIMER_RESTART
;
4151 struct perf_sample_data data
;
4152 struct pt_regs
*regs
;
4153 struct perf_event
*event
;
4156 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
4157 event
->pmu
->read(event
);
4159 perf_sample_data_init(&data
, 0);
4160 data
.period
= event
->hw
.last_period
;
4161 regs
= get_irq_regs();
4163 * In case we exclude kernel IPs or are somehow not in interrupt
4164 * context, provide the next best thing, the user IP.
4166 if ((event
->attr
.exclude_kernel
|| !regs
) &&
4167 !event
->attr
.exclude_user
)
4168 regs
= task_pt_regs(current
);
4171 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
4172 if (perf_event_overflow(event
, 0, &data
, regs
))
4173 ret
= HRTIMER_NORESTART
;
4176 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
4177 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
4182 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
4184 struct hw_perf_event
*hwc
= &event
->hw
;
4186 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
4187 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
4188 if (hwc
->sample_period
) {
4191 if (hwc
->remaining
) {
4192 if (hwc
->remaining
< 0)
4195 period
= hwc
->remaining
;
4198 period
= max_t(u64
, 10000, hwc
->sample_period
);
4200 __hrtimer_start_range_ns(&hwc
->hrtimer
,
4201 ns_to_ktime(period
), 0,
4202 HRTIMER_MODE_REL
, 0);
4206 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
4208 struct hw_perf_event
*hwc
= &event
->hw
;
4210 if (hwc
->sample_period
) {
4211 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
4212 hwc
->remaining
= ktime_to_ns(remaining
);
4214 hrtimer_cancel(&hwc
->hrtimer
);
4219 * Software event: cpu wall time clock
4222 static void cpu_clock_perf_event_update(struct perf_event
*event
)
4224 int cpu
= raw_smp_processor_id();
4228 now
= cpu_clock(cpu
);
4229 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4230 atomic64_add(now
- prev
, &event
->count
);
4233 static int cpu_clock_perf_event_enable(struct perf_event
*event
)
4235 struct hw_perf_event
*hwc
= &event
->hw
;
4236 int cpu
= raw_smp_processor_id();
4238 atomic64_set(&hwc
->prev_count
, cpu_clock(cpu
));
4239 perf_swevent_start_hrtimer(event
);
4244 static void cpu_clock_perf_event_disable(struct perf_event
*event
)
4246 perf_swevent_cancel_hrtimer(event
);
4247 cpu_clock_perf_event_update(event
);
4250 static void cpu_clock_perf_event_read(struct perf_event
*event
)
4252 cpu_clock_perf_event_update(event
);
4255 static const struct pmu perf_ops_cpu_clock
= {
4256 .enable
= cpu_clock_perf_event_enable
,
4257 .disable
= cpu_clock_perf_event_disable
,
4258 .read
= cpu_clock_perf_event_read
,
4262 * Software event: task time clock
4265 static void task_clock_perf_event_update(struct perf_event
*event
, u64 now
)
4270 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4272 atomic64_add(delta
, &event
->count
);
4275 static int task_clock_perf_event_enable(struct perf_event
*event
)
4277 struct hw_perf_event
*hwc
= &event
->hw
;
4280 now
= event
->ctx
->time
;
4282 atomic64_set(&hwc
->prev_count
, now
);
4284 perf_swevent_start_hrtimer(event
);
4289 static void task_clock_perf_event_disable(struct perf_event
*event
)
4291 perf_swevent_cancel_hrtimer(event
);
4292 task_clock_perf_event_update(event
, event
->ctx
->time
);
4296 static void task_clock_perf_event_read(struct perf_event
*event
)
4301 update_context_time(event
->ctx
);
4302 time
= event
->ctx
->time
;
4304 u64 now
= perf_clock();
4305 u64 delta
= now
- event
->ctx
->timestamp
;
4306 time
= event
->ctx
->time
+ delta
;
4309 task_clock_perf_event_update(event
, time
);
4312 static const struct pmu perf_ops_task_clock
= {
4313 .enable
= task_clock_perf_event_enable
,
4314 .disable
= task_clock_perf_event_disable
,
4315 .read
= task_clock_perf_event_read
,
4318 #ifdef CONFIG_EVENT_TRACING
4320 void perf_tp_event(int event_id
, u64 addr
, u64 count
, void *record
,
4323 struct pt_regs
*regs
= get_irq_regs();
4324 struct perf_sample_data data
;
4325 struct perf_raw_record raw
= {
4330 perf_sample_data_init(&data
, addr
);
4334 regs
= task_pt_regs(current
);
4336 /* Trace events already protected against recursion */
4337 do_perf_sw_event(PERF_TYPE_TRACEPOINT
, event_id
, count
, 1,
4340 EXPORT_SYMBOL_GPL(perf_tp_event
);
4342 static int perf_tp_event_match(struct perf_event
*event
,
4343 struct perf_sample_data
*data
)
4345 void *record
= data
->raw
->data
;
4347 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
4352 static void tp_perf_event_destroy(struct perf_event
*event
)
4354 ftrace_profile_disable(event
->attr
.config
);
4357 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4360 * Raw tracepoint data is a severe data leak, only allow root to
4363 if ((event
->attr
.sample_type
& PERF_SAMPLE_RAW
) &&
4364 perf_paranoid_tracepoint_raw() &&
4365 !capable(CAP_SYS_ADMIN
))
4366 return ERR_PTR(-EPERM
);
4368 if (ftrace_profile_enable(event
->attr
.config
))
4371 event
->destroy
= tp_perf_event_destroy
;
4373 return &perf_ops_generic
;
4376 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4381 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4384 filter_str
= strndup_user(arg
, PAGE_SIZE
);
4385 if (IS_ERR(filter_str
))
4386 return PTR_ERR(filter_str
);
4388 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
4394 static void perf_event_free_filter(struct perf_event
*event
)
4396 ftrace_profile_free_filter(event
);
4401 static int perf_tp_event_match(struct perf_event
*event
,
4402 struct perf_sample_data
*data
)
4407 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4412 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4417 static void perf_event_free_filter(struct perf_event
*event
)
4421 #endif /* CONFIG_EVENT_TRACING */
4423 #ifdef CONFIG_HAVE_HW_BREAKPOINT
4424 static void bp_perf_event_destroy(struct perf_event
*event
)
4426 release_bp_slot(event
);
4429 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4433 err
= register_perf_hw_breakpoint(bp
);
4435 return ERR_PTR(err
);
4437 bp
->destroy
= bp_perf_event_destroy
;
4439 return &perf_ops_bp
;
4442 void perf_bp_event(struct perf_event
*bp
, void *data
)
4444 struct perf_sample_data sample
;
4445 struct pt_regs
*regs
= data
;
4447 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
4449 if (!perf_exclude_event(bp
, regs
))
4450 perf_swevent_add(bp
, 1, 1, &sample
, regs
);
4453 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4458 void perf_bp_event(struct perf_event
*bp
, void *regs
)
4463 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4465 static void sw_perf_event_destroy(struct perf_event
*event
)
4467 u64 event_id
= event
->attr
.config
;
4469 WARN_ON(event
->parent
);
4471 atomic_dec(&perf_swevent_enabled
[event_id
]);
4474 static const struct pmu
*sw_perf_event_init(struct perf_event
*event
)
4476 const struct pmu
*pmu
= NULL
;
4477 u64 event_id
= event
->attr
.config
;
4480 * Software events (currently) can't in general distinguish
4481 * between user, kernel and hypervisor events.
4482 * However, context switches and cpu migrations are considered
4483 * to be kernel events, and page faults are never hypervisor
4487 case PERF_COUNT_SW_CPU_CLOCK
:
4488 pmu
= &perf_ops_cpu_clock
;
4491 case PERF_COUNT_SW_TASK_CLOCK
:
4493 * If the user instantiates this as a per-cpu event,
4494 * use the cpu_clock event instead.
4496 if (event
->ctx
->task
)
4497 pmu
= &perf_ops_task_clock
;
4499 pmu
= &perf_ops_cpu_clock
;
4502 case PERF_COUNT_SW_PAGE_FAULTS
:
4503 case PERF_COUNT_SW_PAGE_FAULTS_MIN
:
4504 case PERF_COUNT_SW_PAGE_FAULTS_MAJ
:
4505 case PERF_COUNT_SW_CONTEXT_SWITCHES
:
4506 case PERF_COUNT_SW_CPU_MIGRATIONS
:
4507 case PERF_COUNT_SW_ALIGNMENT_FAULTS
:
4508 case PERF_COUNT_SW_EMULATION_FAULTS
:
4509 if (!event
->parent
) {
4510 atomic_inc(&perf_swevent_enabled
[event_id
]);
4511 event
->destroy
= sw_perf_event_destroy
;
4513 pmu
= &perf_ops_generic
;
4521 * Allocate and initialize a event structure
4523 static struct perf_event
*
4524 perf_event_alloc(struct perf_event_attr
*attr
,
4526 struct perf_event_context
*ctx
,
4527 struct perf_event
*group_leader
,
4528 struct perf_event
*parent_event
,
4529 perf_overflow_handler_t overflow_handler
,
4532 const struct pmu
*pmu
;
4533 struct perf_event
*event
;
4534 struct hw_perf_event
*hwc
;
4537 event
= kzalloc(sizeof(*event
), gfpflags
);
4539 return ERR_PTR(-ENOMEM
);
4542 * Single events are their own group leaders, with an
4543 * empty sibling list:
4546 group_leader
= event
;
4548 mutex_init(&event
->child_mutex
);
4549 INIT_LIST_HEAD(&event
->child_list
);
4551 INIT_LIST_HEAD(&event
->group_entry
);
4552 INIT_LIST_HEAD(&event
->event_entry
);
4553 INIT_LIST_HEAD(&event
->sibling_list
);
4554 init_waitqueue_head(&event
->waitq
);
4556 mutex_init(&event
->mmap_mutex
);
4559 event
->attr
= *attr
;
4560 event
->group_leader
= group_leader
;
4565 event
->parent
= parent_event
;
4567 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
4568 event
->id
= atomic64_inc_return(&perf_event_id
);
4570 event
->state
= PERF_EVENT_STATE_INACTIVE
;
4572 if (!overflow_handler
&& parent_event
)
4573 overflow_handler
= parent_event
->overflow_handler
;
4575 event
->overflow_handler
= overflow_handler
;
4578 event
->state
= PERF_EVENT_STATE_OFF
;
4583 hwc
->sample_period
= attr
->sample_period
;
4584 if (attr
->freq
&& attr
->sample_freq
)
4585 hwc
->sample_period
= 1;
4586 hwc
->last_period
= hwc
->sample_period
;
4588 atomic64_set(&hwc
->period_left
, hwc
->sample_period
);
4591 * we currently do not support PERF_FORMAT_GROUP on inherited events
4593 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
4596 switch (attr
->type
) {
4598 case PERF_TYPE_HARDWARE
:
4599 case PERF_TYPE_HW_CACHE
:
4600 pmu
= hw_perf_event_init(event
);
4603 case PERF_TYPE_SOFTWARE
:
4604 pmu
= sw_perf_event_init(event
);
4607 case PERF_TYPE_TRACEPOINT
:
4608 pmu
= tp_perf_event_init(event
);
4611 case PERF_TYPE_BREAKPOINT
:
4612 pmu
= bp_perf_event_init(event
);
4623 else if (IS_ERR(pmu
))
4628 put_pid_ns(event
->ns
);
4630 return ERR_PTR(err
);
4635 if (!event
->parent
) {
4636 atomic_inc(&nr_events
);
4637 if (event
->attr
.mmap
)
4638 atomic_inc(&nr_mmap_events
);
4639 if (event
->attr
.comm
)
4640 atomic_inc(&nr_comm_events
);
4641 if (event
->attr
.task
)
4642 atomic_inc(&nr_task_events
);
4648 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
4649 struct perf_event_attr
*attr
)
4654 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
4658 * zero the full structure, so that a short copy will be nice.
4660 memset(attr
, 0, sizeof(*attr
));
4662 ret
= get_user(size
, &uattr
->size
);
4666 if (size
> PAGE_SIZE
) /* silly large */
4669 if (!size
) /* abi compat */
4670 size
= PERF_ATTR_SIZE_VER0
;
4672 if (size
< PERF_ATTR_SIZE_VER0
)
4676 * If we're handed a bigger struct than we know of,
4677 * ensure all the unknown bits are 0 - i.e. new
4678 * user-space does not rely on any kernel feature
4679 * extensions we dont know about yet.
4681 if (size
> sizeof(*attr
)) {
4682 unsigned char __user
*addr
;
4683 unsigned char __user
*end
;
4686 addr
= (void __user
*)uattr
+ sizeof(*attr
);
4687 end
= (void __user
*)uattr
+ size
;
4689 for (; addr
< end
; addr
++) {
4690 ret
= get_user(val
, addr
);
4696 size
= sizeof(*attr
);
4699 ret
= copy_from_user(attr
, uattr
, size
);
4704 * If the type exists, the corresponding creation will verify
4707 if (attr
->type
>= PERF_TYPE_MAX
)
4710 if (attr
->__reserved_1
)
4713 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
4716 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
4723 put_user(sizeof(*attr
), &uattr
->size
);
4728 static int perf_event_set_output(struct perf_event
*event
, int output_fd
)
4730 struct perf_event
*output_event
= NULL
;
4731 struct file
*output_file
= NULL
;
4732 struct perf_event
*old_output
;
4733 int fput_needed
= 0;
4739 output_file
= fget_light(output_fd
, &fput_needed
);
4743 if (output_file
->f_op
!= &perf_fops
)
4746 output_event
= output_file
->private_data
;
4748 /* Don't chain output fds */
4749 if (output_event
->output
)
4752 /* Don't set an output fd when we already have an output channel */
4756 atomic_long_inc(&output_file
->f_count
);
4759 mutex_lock(&event
->mmap_mutex
);
4760 old_output
= event
->output
;
4761 rcu_assign_pointer(event
->output
, output_event
);
4762 mutex_unlock(&event
->mmap_mutex
);
4766 * we need to make sure no existing perf_output_*()
4767 * is still referencing this event.
4770 fput(old_output
->filp
);
4775 fput_light(output_file
, fput_needed
);
4780 * sys_perf_event_open - open a performance event, associate it to a task/cpu
4782 * @attr_uptr: event_id type attributes for monitoring/sampling
4785 * @group_fd: group leader event fd
4787 SYSCALL_DEFINE5(perf_event_open
,
4788 struct perf_event_attr __user
*, attr_uptr
,
4789 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
4791 struct perf_event
*event
, *group_leader
;
4792 struct perf_event_attr attr
;
4793 struct perf_event_context
*ctx
;
4794 struct file
*event_file
= NULL
;
4795 struct file
*group_file
= NULL
;
4796 int fput_needed
= 0;
4797 int fput_needed2
= 0;
4800 /* for future expandability... */
4801 if (flags
& ~(PERF_FLAG_FD_NO_GROUP
| PERF_FLAG_FD_OUTPUT
))
4804 err
= perf_copy_attr(attr_uptr
, &attr
);
4808 if (!attr
.exclude_kernel
) {
4809 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
4814 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
4819 * Get the target context (task or percpu):
4821 ctx
= find_get_context(pid
, cpu
);
4823 return PTR_ERR(ctx
);
4826 * Look up the group leader (we will attach this event to it):
4828 group_leader
= NULL
;
4829 if (group_fd
!= -1 && !(flags
& PERF_FLAG_FD_NO_GROUP
)) {
4831 group_file
= fget_light(group_fd
, &fput_needed
);
4833 goto err_put_context
;
4834 if (group_file
->f_op
!= &perf_fops
)
4835 goto err_put_context
;
4837 group_leader
= group_file
->private_data
;
4839 * Do not allow a recursive hierarchy (this new sibling
4840 * becoming part of another group-sibling):
4842 if (group_leader
->group_leader
!= group_leader
)
4843 goto err_put_context
;
4845 * Do not allow to attach to a group in a different
4846 * task or CPU context:
4848 if (group_leader
->ctx
!= ctx
)
4849 goto err_put_context
;
4851 * Only a group leader can be exclusive or pinned
4853 if (attr
.exclusive
|| attr
.pinned
)
4854 goto err_put_context
;
4857 event
= perf_event_alloc(&attr
, cpu
, ctx
, group_leader
,
4858 NULL
, NULL
, GFP_KERNEL
);
4859 err
= PTR_ERR(event
);
4861 goto err_put_context
;
4863 err
= anon_inode_getfd("[perf_event]", &perf_fops
, event
, O_RDWR
);
4865 goto err_free_put_context
;
4867 event_file
= fget_light(err
, &fput_needed2
);
4869 goto err_free_put_context
;
4871 if (flags
& PERF_FLAG_FD_OUTPUT
) {
4872 err
= perf_event_set_output(event
, group_fd
);
4874 goto err_fput_free_put_context
;
4877 event
->filp
= event_file
;
4878 WARN_ON_ONCE(ctx
->parent_ctx
);
4879 mutex_lock(&ctx
->mutex
);
4880 perf_install_in_context(ctx
, event
, cpu
);
4882 mutex_unlock(&ctx
->mutex
);
4884 event
->owner
= current
;
4885 get_task_struct(current
);
4886 mutex_lock(¤t
->perf_event_mutex
);
4887 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
4888 mutex_unlock(¤t
->perf_event_mutex
);
4890 err_fput_free_put_context
:
4891 fput_light(event_file
, fput_needed2
);
4893 err_free_put_context
:
4901 fput_light(group_file
, fput_needed
);
4907 * perf_event_create_kernel_counter
4909 * @attr: attributes of the counter to create
4910 * @cpu: cpu in which the counter is bound
4911 * @pid: task to profile
4914 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
4916 perf_overflow_handler_t overflow_handler
)
4918 struct perf_event
*event
;
4919 struct perf_event_context
*ctx
;
4923 * Get the target context (task or percpu):
4926 ctx
= find_get_context(pid
, cpu
);
4932 event
= perf_event_alloc(attr
, cpu
, ctx
, NULL
,
4933 NULL
, overflow_handler
, GFP_KERNEL
);
4934 if (IS_ERR(event
)) {
4935 err
= PTR_ERR(event
);
4936 goto err_put_context
;
4940 WARN_ON_ONCE(ctx
->parent_ctx
);
4941 mutex_lock(&ctx
->mutex
);
4942 perf_install_in_context(ctx
, event
, cpu
);
4944 mutex_unlock(&ctx
->mutex
);
4946 event
->owner
= current
;
4947 get_task_struct(current
);
4948 mutex_lock(¤t
->perf_event_mutex
);
4949 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
4950 mutex_unlock(¤t
->perf_event_mutex
);
4957 return ERR_PTR(err
);
4959 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
4962 * inherit a event from parent task to child task:
4964 static struct perf_event
*
4965 inherit_event(struct perf_event
*parent_event
,
4966 struct task_struct
*parent
,
4967 struct perf_event_context
*parent_ctx
,
4968 struct task_struct
*child
,
4969 struct perf_event
*group_leader
,
4970 struct perf_event_context
*child_ctx
)
4972 struct perf_event
*child_event
;
4975 * Instead of creating recursive hierarchies of events,
4976 * we link inherited events back to the original parent,
4977 * which has a filp for sure, which we use as the reference
4980 if (parent_event
->parent
)
4981 parent_event
= parent_event
->parent
;
4983 child_event
= perf_event_alloc(&parent_event
->attr
,
4984 parent_event
->cpu
, child_ctx
,
4985 group_leader
, parent_event
,
4987 if (IS_ERR(child_event
))
4992 * Make the child state follow the state of the parent event,
4993 * not its attr.disabled bit. We hold the parent's mutex,
4994 * so we won't race with perf_event_{en, dis}able_family.
4996 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
4997 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
4999 child_event
->state
= PERF_EVENT_STATE_OFF
;
5001 if (parent_event
->attr
.freq
) {
5002 u64 sample_period
= parent_event
->hw
.sample_period
;
5003 struct hw_perf_event
*hwc
= &child_event
->hw
;
5005 hwc
->sample_period
= sample_period
;
5006 hwc
->last_period
= sample_period
;
5008 atomic64_set(&hwc
->period_left
, sample_period
);
5011 child_event
->overflow_handler
= parent_event
->overflow_handler
;
5014 * Link it up in the child's context:
5016 add_event_to_ctx(child_event
, child_ctx
);
5019 * Get a reference to the parent filp - we will fput it
5020 * when the child event exits. This is safe to do because
5021 * we are in the parent and we know that the filp still
5022 * exists and has a nonzero count:
5024 atomic_long_inc(&parent_event
->filp
->f_count
);
5027 * Link this into the parent event's child list
5029 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5030 mutex_lock(&parent_event
->child_mutex
);
5031 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
5032 mutex_unlock(&parent_event
->child_mutex
);
5037 static int inherit_group(struct perf_event
*parent_event
,
5038 struct task_struct
*parent
,
5039 struct perf_event_context
*parent_ctx
,
5040 struct task_struct
*child
,
5041 struct perf_event_context
*child_ctx
)
5043 struct perf_event
*leader
;
5044 struct perf_event
*sub
;
5045 struct perf_event
*child_ctr
;
5047 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
5048 child
, NULL
, child_ctx
);
5050 return PTR_ERR(leader
);
5051 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
5052 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
5053 child
, leader
, child_ctx
);
5054 if (IS_ERR(child_ctr
))
5055 return PTR_ERR(child_ctr
);
5060 static void sync_child_event(struct perf_event
*child_event
,
5061 struct task_struct
*child
)
5063 struct perf_event
*parent_event
= child_event
->parent
;
5066 if (child_event
->attr
.inherit_stat
)
5067 perf_event_read_event(child_event
, child
);
5069 child_val
= atomic64_read(&child_event
->count
);
5072 * Add back the child's count to the parent's count:
5074 atomic64_add(child_val
, &parent_event
->count
);
5075 atomic64_add(child_event
->total_time_enabled
,
5076 &parent_event
->child_total_time_enabled
);
5077 atomic64_add(child_event
->total_time_running
,
5078 &parent_event
->child_total_time_running
);
5081 * Remove this event from the parent's list
5083 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5084 mutex_lock(&parent_event
->child_mutex
);
5085 list_del_init(&child_event
->child_list
);
5086 mutex_unlock(&parent_event
->child_mutex
);
5089 * Release the parent event, if this was the last
5092 fput(parent_event
->filp
);
5096 __perf_event_exit_task(struct perf_event
*child_event
,
5097 struct perf_event_context
*child_ctx
,
5098 struct task_struct
*child
)
5100 struct perf_event
*parent_event
;
5102 perf_event_remove_from_context(child_event
);
5104 parent_event
= child_event
->parent
;
5106 * It can happen that parent exits first, and has events
5107 * that are still around due to the child reference. These
5108 * events need to be zapped - but otherwise linger.
5111 sync_child_event(child_event
, child
);
5112 free_event(child_event
);
5117 * When a child task exits, feed back event values to parent events.
5119 void perf_event_exit_task(struct task_struct
*child
)
5121 struct perf_event
*child_event
, *tmp
;
5122 struct perf_event_context
*child_ctx
;
5123 unsigned long flags
;
5125 if (likely(!child
->perf_event_ctxp
)) {
5126 perf_event_task(child
, NULL
, 0);
5130 local_irq_save(flags
);
5132 * We can't reschedule here because interrupts are disabled,
5133 * and either child is current or it is a task that can't be
5134 * scheduled, so we are now safe from rescheduling changing
5137 child_ctx
= child
->perf_event_ctxp
;
5138 __perf_event_task_sched_out(child_ctx
);
5141 * Take the context lock here so that if find_get_context is
5142 * reading child->perf_event_ctxp, we wait until it has
5143 * incremented the context's refcount before we do put_ctx below.
5145 raw_spin_lock(&child_ctx
->lock
);
5146 child
->perf_event_ctxp
= NULL
;
5148 * If this context is a clone; unclone it so it can't get
5149 * swapped to another process while we're removing all
5150 * the events from it.
5152 unclone_ctx(child_ctx
);
5153 update_context_time(child_ctx
);
5154 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
5157 * Report the task dead after unscheduling the events so that we
5158 * won't get any samples after PERF_RECORD_EXIT. We can however still
5159 * get a few PERF_RECORD_READ events.
5161 perf_event_task(child
, child_ctx
, 0);
5164 * We can recurse on the same lock type through:
5166 * __perf_event_exit_task()
5167 * sync_child_event()
5168 * fput(parent_event->filp)
5170 * mutex_lock(&ctx->mutex)
5172 * But since its the parent context it won't be the same instance.
5174 mutex_lock_nested(&child_ctx
->mutex
, SINGLE_DEPTH_NESTING
);
5177 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
5179 __perf_event_exit_task(child_event
, child_ctx
, child
);
5181 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
5183 __perf_event_exit_task(child_event
, child_ctx
, child
);
5186 * If the last event was a group event, it will have appended all
5187 * its siblings to the list, but we obtained 'tmp' before that which
5188 * will still point to the list head terminating the iteration.
5190 if (!list_empty(&child_ctx
->pinned_groups
) ||
5191 !list_empty(&child_ctx
->flexible_groups
))
5194 mutex_unlock(&child_ctx
->mutex
);
5199 static void perf_free_event(struct perf_event
*event
,
5200 struct perf_event_context
*ctx
)
5202 struct perf_event
*parent
= event
->parent
;
5204 if (WARN_ON_ONCE(!parent
))
5207 mutex_lock(&parent
->child_mutex
);
5208 list_del_init(&event
->child_list
);
5209 mutex_unlock(&parent
->child_mutex
);
5213 list_del_event(event
, ctx
);
5218 * free an unexposed, unused context as created by inheritance by
5219 * init_task below, used by fork() in case of fail.
5221 void perf_event_free_task(struct task_struct
*task
)
5223 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
5224 struct perf_event
*event
, *tmp
;
5229 mutex_lock(&ctx
->mutex
);
5231 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5232 perf_free_event(event
, ctx
);
5234 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
5236 perf_free_event(event
, ctx
);
5238 if (!list_empty(&ctx
->pinned_groups
) ||
5239 !list_empty(&ctx
->flexible_groups
))
5242 mutex_unlock(&ctx
->mutex
);
5248 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
5249 struct perf_event_context
*parent_ctx
,
5250 struct task_struct
*child
,
5254 struct perf_event_context
*child_ctx
= child
->perf_event_ctxp
;
5256 if (!event
->attr
.inherit
) {
5263 * This is executed from the parent task context, so
5264 * inherit events that have been marked for cloning.
5265 * First allocate and initialize a context for the
5269 child_ctx
= kzalloc(sizeof(struct perf_event_context
),
5274 __perf_event_init_context(child_ctx
, child
);
5275 child
->perf_event_ctxp
= child_ctx
;
5276 get_task_struct(child
);
5279 ret
= inherit_group(event
, parent
, parent_ctx
,
5290 * Initialize the perf_event context in task_struct
5292 int perf_event_init_task(struct task_struct
*child
)
5294 struct perf_event_context
*child_ctx
, *parent_ctx
;
5295 struct perf_event_context
*cloned_ctx
;
5296 struct perf_event
*event
;
5297 struct task_struct
*parent
= current
;
5298 int inherited_all
= 1;
5301 child
->perf_event_ctxp
= NULL
;
5303 mutex_init(&child
->perf_event_mutex
);
5304 INIT_LIST_HEAD(&child
->perf_event_list
);
5306 if (likely(!parent
->perf_event_ctxp
))
5310 * If the parent's context is a clone, pin it so it won't get
5313 parent_ctx
= perf_pin_task_context(parent
);
5316 * No need to check if parent_ctx != NULL here; since we saw
5317 * it non-NULL earlier, the only reason for it to become NULL
5318 * is if we exit, and since we're currently in the middle of
5319 * a fork we can't be exiting at the same time.
5323 * Lock the parent list. No need to lock the child - not PID
5324 * hashed yet and not running, so nobody can access it.
5326 mutex_lock(&parent_ctx
->mutex
);
5329 * We dont have to disable NMIs - we are only looking at
5330 * the list, not manipulating it:
5332 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
5333 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5339 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
5340 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5346 child_ctx
= child
->perf_event_ctxp
;
5348 if (child_ctx
&& inherited_all
) {
5350 * Mark the child context as a clone of the parent
5351 * context, or of whatever the parent is a clone of.
5352 * Note that if the parent is a clone, it could get
5353 * uncloned at any point, but that doesn't matter
5354 * because the list of events and the generation
5355 * count can't have changed since we took the mutex.
5357 cloned_ctx
= rcu_dereference(parent_ctx
->parent_ctx
);
5359 child_ctx
->parent_ctx
= cloned_ctx
;
5360 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
5362 child_ctx
->parent_ctx
= parent_ctx
;
5363 child_ctx
->parent_gen
= parent_ctx
->generation
;
5365 get_ctx(child_ctx
->parent_ctx
);
5368 mutex_unlock(&parent_ctx
->mutex
);
5370 perf_unpin_context(parent_ctx
);
5375 static void __cpuinit
perf_event_init_cpu(int cpu
)
5377 struct perf_cpu_context
*cpuctx
;
5379 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5380 __perf_event_init_context(&cpuctx
->ctx
, NULL
);
5382 spin_lock(&perf_resource_lock
);
5383 cpuctx
->max_pertask
= perf_max_events
- perf_reserved_percpu
;
5384 spin_unlock(&perf_resource_lock
);
5386 hw_perf_event_setup(cpu
);
5389 #ifdef CONFIG_HOTPLUG_CPU
5390 static void __perf_event_exit_cpu(void *info
)
5392 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
5393 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5394 struct perf_event
*event
, *tmp
;
5396 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5397 __perf_event_remove_from_context(event
);
5398 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
5399 __perf_event_remove_from_context(event
);
5401 static void perf_event_exit_cpu(int cpu
)
5403 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5404 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5406 mutex_lock(&ctx
->mutex
);
5407 smp_call_function_single(cpu
, __perf_event_exit_cpu
, NULL
, 1);
5408 mutex_unlock(&ctx
->mutex
);
5411 static inline void perf_event_exit_cpu(int cpu
) { }
5414 static int __cpuinit
5415 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
5417 unsigned int cpu
= (long)hcpu
;
5421 case CPU_UP_PREPARE
:
5422 case CPU_UP_PREPARE_FROZEN
:
5423 perf_event_init_cpu(cpu
);
5427 case CPU_ONLINE_FROZEN
:
5428 hw_perf_event_setup_online(cpu
);
5431 case CPU_DOWN_PREPARE
:
5432 case CPU_DOWN_PREPARE_FROZEN
:
5433 perf_event_exit_cpu(cpu
);
5437 hw_perf_event_setup_offline(cpu
);
5448 * This has to have a higher priority than migration_notifier in sched.c.
5450 static struct notifier_block __cpuinitdata perf_cpu_nb
= {
5451 .notifier_call
= perf_cpu_notify
,
5455 void __init
perf_event_init(void)
5457 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_UP_PREPARE
,
5458 (void *)(long)smp_processor_id());
5459 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_ONLINE
,
5460 (void *)(long)smp_processor_id());
5461 register_cpu_notifier(&perf_cpu_nb
);
5464 static ssize_t
perf_show_reserve_percpu(struct sysdev_class
*class,
5465 struct sysdev_class_attribute
*attr
,
5468 return sprintf(buf
, "%d\n", perf_reserved_percpu
);
5472 perf_set_reserve_percpu(struct sysdev_class
*class,
5473 struct sysdev_class_attribute
*attr
,
5477 struct perf_cpu_context
*cpuctx
;
5481 err
= strict_strtoul(buf
, 10, &val
);
5484 if (val
> perf_max_events
)
5487 spin_lock(&perf_resource_lock
);
5488 perf_reserved_percpu
= val
;
5489 for_each_online_cpu(cpu
) {
5490 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5491 raw_spin_lock_irq(&cpuctx
->ctx
.lock
);
5492 mpt
= min(perf_max_events
- cpuctx
->ctx
.nr_events
,
5493 perf_max_events
- perf_reserved_percpu
);
5494 cpuctx
->max_pertask
= mpt
;
5495 raw_spin_unlock_irq(&cpuctx
->ctx
.lock
);
5497 spin_unlock(&perf_resource_lock
);
5502 static ssize_t
perf_show_overcommit(struct sysdev_class
*class,
5503 struct sysdev_class_attribute
*attr
,
5506 return sprintf(buf
, "%d\n", perf_overcommit
);
5510 perf_set_overcommit(struct sysdev_class
*class,
5511 struct sysdev_class_attribute
*attr
,
5512 const char *buf
, size_t count
)
5517 err
= strict_strtoul(buf
, 10, &val
);
5523 spin_lock(&perf_resource_lock
);
5524 perf_overcommit
= val
;
5525 spin_unlock(&perf_resource_lock
);
5530 static SYSDEV_CLASS_ATTR(
5533 perf_show_reserve_percpu
,
5534 perf_set_reserve_percpu
5537 static SYSDEV_CLASS_ATTR(
5540 perf_show_overcommit
,
5544 static struct attribute
*perfclass_attrs
[] = {
5545 &attr_reserve_percpu
.attr
,
5546 &attr_overcommit
.attr
,
5550 static struct attribute_group perfclass_attr_group
= {
5551 .attrs
= perfclass_attrs
,
5552 .name
= "perf_events",
5555 static int __init
perf_event_sysfs_init(void)
5557 return sysfs_create_group(&cpu_sysdev_class
.kset
.kobj
,
5558 &perfclass_attr_group
);
5560 device_initcall(perf_event_sysfs_init
);