2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/file.h>
17 #include <linux/poll.h>
18 #include <linux/slab.h>
19 #include <linux/hash.h>
20 #include <linux/sysfs.h>
21 #include <linux/dcache.h>
22 #include <linux/percpu.h>
23 #include <linux/ptrace.h>
24 #include <linux/vmstat.h>
25 #include <linux/vmalloc.h>
26 #include <linux/hardirq.h>
27 #include <linux/rculist.h>
28 #include <linux/uaccess.h>
29 #include <linux/syscalls.h>
30 #include <linux/anon_inodes.h>
31 #include <linux/kernel_stat.h>
32 #include <linux/perf_event.h>
33 #include <linux/ftrace_event.h>
34 #include <linux/hw_breakpoint.h>
36 #include <asm/irq_regs.h>
39 * Each CPU has a list of per CPU events:
41 static DEFINE_PER_CPU(struct perf_cpu_context
, perf_cpu_context
);
43 int perf_max_events __read_mostly
= 1;
44 static int perf_reserved_percpu __read_mostly
;
45 static int perf_overcommit __read_mostly
= 1;
47 static atomic_t nr_events __read_mostly
;
48 static atomic_t nr_mmap_events __read_mostly
;
49 static atomic_t nr_comm_events __read_mostly
;
50 static atomic_t nr_task_events __read_mostly
;
53 * perf event paranoia level:
54 * -1 - not paranoid at all
55 * 0 - disallow raw tracepoint access for unpriv
56 * 1 - disallow cpu events for unpriv
57 * 2 - disallow kernel profiling for unpriv
59 int sysctl_perf_event_paranoid __read_mostly
= 1;
61 int sysctl_perf_event_mlock __read_mostly
= 512; /* 'free' kb per user */
64 * max perf event sample rate
66 int sysctl_perf_event_sample_rate __read_mostly
= 100000;
68 static atomic64_t perf_event_id
;
71 * Lock for (sysadmin-configurable) event reservations:
73 static DEFINE_SPINLOCK(perf_resource_lock
);
76 * Architecture provided APIs - weak aliases:
78 extern __weak
const struct pmu
*hw_perf_event_init(struct perf_event
*event
)
83 void __weak
hw_perf_disable(void) { barrier(); }
84 void __weak
hw_perf_enable(void) { barrier(); }
86 void __weak
perf_event_print_debug(void) { }
88 static DEFINE_PER_CPU(int, perf_disable_count
);
90 void perf_disable(void)
92 if (!__get_cpu_var(perf_disable_count
)++)
96 void perf_enable(void)
98 if (!--__get_cpu_var(perf_disable_count
))
102 static void get_ctx(struct perf_event_context
*ctx
)
104 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
107 static void free_ctx(struct rcu_head
*head
)
109 struct perf_event_context
*ctx
;
111 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
115 static void put_ctx(struct perf_event_context
*ctx
)
117 if (atomic_dec_and_test(&ctx
->refcount
)) {
119 put_ctx(ctx
->parent_ctx
);
121 put_task_struct(ctx
->task
);
122 call_rcu(&ctx
->rcu_head
, free_ctx
);
126 static void unclone_ctx(struct perf_event_context
*ctx
)
128 if (ctx
->parent_ctx
) {
129 put_ctx(ctx
->parent_ctx
);
130 ctx
->parent_ctx
= NULL
;
135 * If we inherit events we want to return the parent event id
138 static u64
primary_event_id(struct perf_event
*event
)
143 id
= event
->parent
->id
;
149 * Get the perf_event_context for a task and lock it.
150 * This has to cope with with the fact that until it is locked,
151 * the context could get moved to another task.
153 static struct perf_event_context
*
154 perf_lock_task_context(struct task_struct
*task
, unsigned long *flags
)
156 struct perf_event_context
*ctx
;
160 ctx
= rcu_dereference(task
->perf_event_ctxp
);
163 * If this context is a clone of another, it might
164 * get swapped for another underneath us by
165 * perf_event_task_sched_out, though the
166 * rcu_read_lock() protects us from any context
167 * getting freed. Lock the context and check if it
168 * got swapped before we could get the lock, and retry
169 * if so. If we locked the right context, then it
170 * can't get swapped on us any more.
172 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
173 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
)) {
174 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
178 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
179 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
188 * Get the context for a task and increment its pin_count so it
189 * can't get swapped to another task. This also increments its
190 * reference count so that the context can't get freed.
192 static struct perf_event_context
*perf_pin_task_context(struct task_struct
*task
)
194 struct perf_event_context
*ctx
;
197 ctx
= perf_lock_task_context(task
, &flags
);
200 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
205 static void perf_unpin_context(struct perf_event_context
*ctx
)
209 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
211 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
215 static inline u64
perf_clock(void)
217 return cpu_clock(raw_smp_processor_id());
221 * Update the record of the current time in a context.
223 static void update_context_time(struct perf_event_context
*ctx
)
225 u64 now
= perf_clock();
227 ctx
->time
+= now
- ctx
->timestamp
;
228 ctx
->timestamp
= now
;
232 * Update the total_time_enabled and total_time_running fields for a event.
234 static void update_event_times(struct perf_event
*event
)
236 struct perf_event_context
*ctx
= event
->ctx
;
239 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
240 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
246 run_end
= event
->tstamp_stopped
;
248 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
250 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
251 run_end
= event
->tstamp_stopped
;
255 event
->total_time_running
= run_end
- event
->tstamp_running
;
258 static struct list_head
*
259 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
261 if (event
->attr
.pinned
)
262 return &ctx
->pinned_groups
;
264 return &ctx
->flexible_groups
;
268 * Add a event from the lists for its context.
269 * Must be called with ctx->mutex and ctx->lock held.
272 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
274 struct perf_event
*group_leader
= event
->group_leader
;
277 * Depending on whether it is a standalone or sibling event,
278 * add it straight to the context's event list, or to the group
279 * leader's sibling list:
281 if (group_leader
== event
) {
282 struct list_head
*list
;
284 if (is_software_event(event
))
285 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
287 list
= ctx_group_list(event
, ctx
);
288 list_add_tail(&event
->group_entry
, list
);
290 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
291 !is_software_event(event
))
292 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
294 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
295 group_leader
->nr_siblings
++;
298 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
300 if (event
->attr
.inherit_stat
)
305 * Remove a event from the lists for its context.
306 * Must be called with ctx->mutex and ctx->lock held.
309 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
311 struct perf_event
*sibling
, *tmp
;
313 if (list_empty(&event
->group_entry
))
316 if (event
->attr
.inherit_stat
)
319 list_del_init(&event
->group_entry
);
320 list_del_rcu(&event
->event_entry
);
322 if (event
->group_leader
!= event
)
323 event
->group_leader
->nr_siblings
--;
325 update_event_times(event
);
328 * If event was in error state, then keep it
329 * that way, otherwise bogus counts will be
330 * returned on read(). The only way to get out
331 * of error state is by explicit re-enabling
334 if (event
->state
> PERF_EVENT_STATE_OFF
)
335 event
->state
= PERF_EVENT_STATE_OFF
;
337 if (event
->state
> PERF_EVENT_STATE_FREE
)
341 * If this was a group event with sibling events then
342 * upgrade the siblings to singleton events by adding them
343 * to the context list directly:
345 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
346 struct list_head
*list
;
348 list
= ctx_group_list(event
, ctx
);
349 list_move_tail(&sibling
->group_entry
, list
);
350 sibling
->group_leader
= sibling
;
352 /* Inherit group flags from the previous leader */
353 sibling
->group_flags
= event
->group_flags
;
358 event_sched_out(struct perf_event
*event
,
359 struct perf_cpu_context
*cpuctx
,
360 struct perf_event_context
*ctx
)
362 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
365 event
->state
= PERF_EVENT_STATE_INACTIVE
;
366 if (event
->pending_disable
) {
367 event
->pending_disable
= 0;
368 event
->state
= PERF_EVENT_STATE_OFF
;
370 event
->tstamp_stopped
= ctx
->time
;
371 event
->pmu
->disable(event
);
374 if (!is_software_event(event
))
375 cpuctx
->active_oncpu
--;
377 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
378 cpuctx
->exclusive
= 0;
382 group_sched_out(struct perf_event
*group_event
,
383 struct perf_cpu_context
*cpuctx
,
384 struct perf_event_context
*ctx
)
386 struct perf_event
*event
;
388 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
391 event_sched_out(group_event
, cpuctx
, ctx
);
394 * Schedule out siblings (if any):
396 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
397 event_sched_out(event
, cpuctx
, ctx
);
399 if (group_event
->attr
.exclusive
)
400 cpuctx
->exclusive
= 0;
404 * Cross CPU call to remove a performance event
406 * We disable the event on the hardware level first. After that we
407 * remove it from the context list.
409 static void __perf_event_remove_from_context(void *info
)
411 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
412 struct perf_event
*event
= info
;
413 struct perf_event_context
*ctx
= event
->ctx
;
416 * If this is a task context, we need to check whether it is
417 * the current task context of this cpu. If not it has been
418 * scheduled out before the smp call arrived.
420 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
423 raw_spin_lock(&ctx
->lock
);
425 * Protect the list operation against NMI by disabling the
426 * events on a global level.
430 event_sched_out(event
, cpuctx
, ctx
);
432 list_del_event(event
, ctx
);
436 * Allow more per task events with respect to the
439 cpuctx
->max_pertask
=
440 min(perf_max_events
- ctx
->nr_events
,
441 perf_max_events
- perf_reserved_percpu
);
445 raw_spin_unlock(&ctx
->lock
);
450 * Remove the event from a task's (or a CPU's) list of events.
452 * Must be called with ctx->mutex held.
454 * CPU events are removed with a smp call. For task events we only
455 * call when the task is on a CPU.
457 * If event->ctx is a cloned context, callers must make sure that
458 * every task struct that event->ctx->task could possibly point to
459 * remains valid. This is OK when called from perf_release since
460 * that only calls us on the top-level context, which can't be a clone.
461 * When called from perf_event_exit_task, it's OK because the
462 * context has been detached from its task.
464 static void perf_event_remove_from_context(struct perf_event
*event
)
466 struct perf_event_context
*ctx
= event
->ctx
;
467 struct task_struct
*task
= ctx
->task
;
471 * Per cpu events are removed via an smp call and
472 * the removal is always successful.
474 smp_call_function_single(event
->cpu
,
475 __perf_event_remove_from_context
,
481 task_oncpu_function_call(task
, __perf_event_remove_from_context
,
484 raw_spin_lock_irq(&ctx
->lock
);
486 * If the context is active we need to retry the smp call.
488 if (ctx
->nr_active
&& !list_empty(&event
->group_entry
)) {
489 raw_spin_unlock_irq(&ctx
->lock
);
494 * The lock prevents that this context is scheduled in so we
495 * can remove the event safely, if the call above did not
498 if (!list_empty(&event
->group_entry
))
499 list_del_event(event
, ctx
);
500 raw_spin_unlock_irq(&ctx
->lock
);
504 * Update total_time_enabled and total_time_running for all events in a group.
506 static void update_group_times(struct perf_event
*leader
)
508 struct perf_event
*event
;
510 update_event_times(leader
);
511 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
512 update_event_times(event
);
516 * Cross CPU call to disable a performance event
518 static void __perf_event_disable(void *info
)
520 struct perf_event
*event
= info
;
521 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
522 struct perf_event_context
*ctx
= event
->ctx
;
525 * If this is a per-task event, need to check whether this
526 * event's task is the current task on this cpu.
528 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
531 raw_spin_lock(&ctx
->lock
);
534 * If the event is on, turn it off.
535 * If it is in error state, leave it in error state.
537 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
538 update_context_time(ctx
);
539 update_group_times(event
);
540 if (event
== event
->group_leader
)
541 group_sched_out(event
, cpuctx
, ctx
);
543 event_sched_out(event
, cpuctx
, ctx
);
544 event
->state
= PERF_EVENT_STATE_OFF
;
547 raw_spin_unlock(&ctx
->lock
);
553 * If event->ctx is a cloned context, callers must make sure that
554 * every task struct that event->ctx->task could possibly point to
555 * remains valid. This condition is satisifed when called through
556 * perf_event_for_each_child or perf_event_for_each because they
557 * hold the top-level event's child_mutex, so any descendant that
558 * goes to exit will block in sync_child_event.
559 * When called from perf_pending_event it's OK because event->ctx
560 * is the current context on this CPU and preemption is disabled,
561 * hence we can't get into perf_event_task_sched_out for this context.
563 void perf_event_disable(struct perf_event
*event
)
565 struct perf_event_context
*ctx
= event
->ctx
;
566 struct task_struct
*task
= ctx
->task
;
570 * Disable the event on the cpu that it's on
572 smp_call_function_single(event
->cpu
, __perf_event_disable
,
578 task_oncpu_function_call(task
, __perf_event_disable
, event
);
580 raw_spin_lock_irq(&ctx
->lock
);
582 * If the event is still active, we need to retry the cross-call.
584 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
585 raw_spin_unlock_irq(&ctx
->lock
);
590 * Since we have the lock this context can't be scheduled
591 * in, so we can change the state safely.
593 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
594 update_group_times(event
);
595 event
->state
= PERF_EVENT_STATE_OFF
;
598 raw_spin_unlock_irq(&ctx
->lock
);
602 event_sched_in(struct perf_event
*event
,
603 struct perf_cpu_context
*cpuctx
,
604 struct perf_event_context
*ctx
)
606 if (event
->state
<= PERF_EVENT_STATE_OFF
)
609 event
->state
= PERF_EVENT_STATE_ACTIVE
;
610 event
->oncpu
= smp_processor_id();
612 * The new state must be visible before we turn it on in the hardware:
616 if (event
->pmu
->enable(event
)) {
617 event
->state
= PERF_EVENT_STATE_INACTIVE
;
622 event
->tstamp_running
+= ctx
->time
- event
->tstamp_stopped
;
624 if (!is_software_event(event
))
625 cpuctx
->active_oncpu
++;
628 if (event
->attr
.exclusive
)
629 cpuctx
->exclusive
= 1;
635 group_sched_in(struct perf_event
*group_event
,
636 struct perf_cpu_context
*cpuctx
,
637 struct perf_event_context
*ctx
)
639 struct perf_event
*event
, *partial_group
= NULL
;
640 const struct pmu
*pmu
= group_event
->pmu
;
644 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
647 /* Check if group transaction availabe */
654 if (event_sched_in(group_event
, cpuctx
, ctx
))
658 * Schedule in siblings as one group (if any):
660 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
661 if (event_sched_in(event
, cpuctx
, ctx
)) {
662 partial_group
= event
;
670 ret
= pmu
->commit_txn(pmu
);
672 pmu
->cancel_txn(pmu
);
678 pmu
->cancel_txn(pmu
);
681 * Groups can be scheduled in as one unit only, so undo any
682 * partial group before returning:
684 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
685 if (event
== partial_group
)
687 event_sched_out(event
, cpuctx
, ctx
);
689 event_sched_out(group_event
, cpuctx
, ctx
);
695 * Work out whether we can put this event group on the CPU now.
697 static int group_can_go_on(struct perf_event
*event
,
698 struct perf_cpu_context
*cpuctx
,
702 * Groups consisting entirely of software events can always go on.
704 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
707 * If an exclusive group is already on, no other hardware
710 if (cpuctx
->exclusive
)
713 * If this group is exclusive and there are already
714 * events on the CPU, it can't go on.
716 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
719 * Otherwise, try to add it if all previous groups were able
725 static void add_event_to_ctx(struct perf_event
*event
,
726 struct perf_event_context
*ctx
)
728 list_add_event(event
, ctx
);
729 event
->tstamp_enabled
= ctx
->time
;
730 event
->tstamp_running
= ctx
->time
;
731 event
->tstamp_stopped
= ctx
->time
;
735 * Cross CPU call to install and enable a performance event
737 * Must be called with ctx->mutex held
739 static void __perf_install_in_context(void *info
)
741 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
742 struct perf_event
*event
= info
;
743 struct perf_event_context
*ctx
= event
->ctx
;
744 struct perf_event
*leader
= event
->group_leader
;
748 * If this is a task context, we need to check whether it is
749 * the current task context of this cpu. If not it has been
750 * scheduled out before the smp call arrived.
751 * Or possibly this is the right context but it isn't
752 * on this cpu because it had no events.
754 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
755 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
757 cpuctx
->task_ctx
= ctx
;
760 raw_spin_lock(&ctx
->lock
);
762 update_context_time(ctx
);
765 * Protect the list operation against NMI by disabling the
766 * events on a global level. NOP for non NMI based events.
770 add_event_to_ctx(event
, ctx
);
772 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
776 * Don't put the event on if it is disabled or if
777 * it is in a group and the group isn't on.
779 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
780 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
784 * An exclusive event can't go on if there are already active
785 * hardware events, and no hardware event can go on if there
786 * is already an exclusive event on.
788 if (!group_can_go_on(event
, cpuctx
, 1))
791 err
= event_sched_in(event
, cpuctx
, ctx
);
795 * This event couldn't go on. If it is in a group
796 * then we have to pull the whole group off.
797 * If the event group is pinned then put it in error state.
800 group_sched_out(leader
, cpuctx
, ctx
);
801 if (leader
->attr
.pinned
) {
802 update_group_times(leader
);
803 leader
->state
= PERF_EVENT_STATE_ERROR
;
807 if (!err
&& !ctx
->task
&& cpuctx
->max_pertask
)
808 cpuctx
->max_pertask
--;
813 raw_spin_unlock(&ctx
->lock
);
817 * Attach a performance event to a context
819 * First we add the event to the list with the hardware enable bit
820 * in event->hw_config cleared.
822 * If the event is attached to a task which is on a CPU we use a smp
823 * call to enable it in the task context. The task might have been
824 * scheduled away, but we check this in the smp call again.
826 * Must be called with ctx->mutex held.
829 perf_install_in_context(struct perf_event_context
*ctx
,
830 struct perf_event
*event
,
833 struct task_struct
*task
= ctx
->task
;
837 * Per cpu events are installed via an smp call and
838 * the install is always successful.
840 smp_call_function_single(cpu
, __perf_install_in_context
,
846 task_oncpu_function_call(task
, __perf_install_in_context
,
849 raw_spin_lock_irq(&ctx
->lock
);
851 * we need to retry the smp call.
853 if (ctx
->is_active
&& list_empty(&event
->group_entry
)) {
854 raw_spin_unlock_irq(&ctx
->lock
);
859 * The lock prevents that this context is scheduled in so we
860 * can add the event safely, if it the call above did not
863 if (list_empty(&event
->group_entry
))
864 add_event_to_ctx(event
, ctx
);
865 raw_spin_unlock_irq(&ctx
->lock
);
869 * Put a event into inactive state and update time fields.
870 * Enabling the leader of a group effectively enables all
871 * the group members that aren't explicitly disabled, so we
872 * have to update their ->tstamp_enabled also.
873 * Note: this works for group members as well as group leaders
874 * since the non-leader members' sibling_lists will be empty.
876 static void __perf_event_mark_enabled(struct perf_event
*event
,
877 struct perf_event_context
*ctx
)
879 struct perf_event
*sub
;
881 event
->state
= PERF_EVENT_STATE_INACTIVE
;
882 event
->tstamp_enabled
= ctx
->time
- event
->total_time_enabled
;
883 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
)
884 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
885 sub
->tstamp_enabled
=
886 ctx
->time
- sub
->total_time_enabled
;
890 * Cross CPU call to enable a performance event
892 static void __perf_event_enable(void *info
)
894 struct perf_event
*event
= info
;
895 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
896 struct perf_event_context
*ctx
= event
->ctx
;
897 struct perf_event
*leader
= event
->group_leader
;
901 * If this is a per-task event, need to check whether this
902 * event's task is the current task on this cpu.
904 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
905 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
907 cpuctx
->task_ctx
= ctx
;
910 raw_spin_lock(&ctx
->lock
);
912 update_context_time(ctx
);
914 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
916 __perf_event_mark_enabled(event
, ctx
);
918 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
922 * If the event is in a group and isn't the group leader,
923 * then don't put it on unless the group is on.
925 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
928 if (!group_can_go_on(event
, cpuctx
, 1)) {
933 err
= group_sched_in(event
, cpuctx
, ctx
);
935 err
= event_sched_in(event
, cpuctx
, ctx
);
941 * If this event can't go on and it's part of a
942 * group, then the whole group has to come off.
945 group_sched_out(leader
, cpuctx
, ctx
);
946 if (leader
->attr
.pinned
) {
947 update_group_times(leader
);
948 leader
->state
= PERF_EVENT_STATE_ERROR
;
953 raw_spin_unlock(&ctx
->lock
);
959 * If event->ctx is a cloned context, callers must make sure that
960 * every task struct that event->ctx->task could possibly point to
961 * remains valid. This condition is satisfied when called through
962 * perf_event_for_each_child or perf_event_for_each as described
963 * for perf_event_disable.
965 void perf_event_enable(struct perf_event
*event
)
967 struct perf_event_context
*ctx
= event
->ctx
;
968 struct task_struct
*task
= ctx
->task
;
972 * Enable the event on the cpu that it's on
974 smp_call_function_single(event
->cpu
, __perf_event_enable
,
979 raw_spin_lock_irq(&ctx
->lock
);
980 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
984 * If the event is in error state, clear that first.
985 * That way, if we see the event in error state below, we
986 * know that it has gone back into error state, as distinct
987 * from the task having been scheduled away before the
988 * cross-call arrived.
990 if (event
->state
== PERF_EVENT_STATE_ERROR
)
991 event
->state
= PERF_EVENT_STATE_OFF
;
994 raw_spin_unlock_irq(&ctx
->lock
);
995 task_oncpu_function_call(task
, __perf_event_enable
, event
);
997 raw_spin_lock_irq(&ctx
->lock
);
1000 * If the context is active and the event is still off,
1001 * we need to retry the cross-call.
1003 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
)
1007 * Since we have the lock this context can't be scheduled
1008 * in, so we can change the state safely.
1010 if (event
->state
== PERF_EVENT_STATE_OFF
)
1011 __perf_event_mark_enabled(event
, ctx
);
1014 raw_spin_unlock_irq(&ctx
->lock
);
1017 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1020 * not supported on inherited events
1022 if (event
->attr
.inherit
)
1025 atomic_add(refresh
, &event
->event_limit
);
1026 perf_event_enable(event
);
1032 EVENT_FLEXIBLE
= 0x1,
1034 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
1037 static void ctx_sched_out(struct perf_event_context
*ctx
,
1038 struct perf_cpu_context
*cpuctx
,
1039 enum event_type_t event_type
)
1041 struct perf_event
*event
;
1043 raw_spin_lock(&ctx
->lock
);
1045 if (likely(!ctx
->nr_events
))
1047 update_context_time(ctx
);
1050 if (!ctx
->nr_active
)
1053 if (event_type
& EVENT_PINNED
)
1054 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1055 group_sched_out(event
, cpuctx
, ctx
);
1057 if (event_type
& EVENT_FLEXIBLE
)
1058 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1059 group_sched_out(event
, cpuctx
, ctx
);
1064 raw_spin_unlock(&ctx
->lock
);
1068 * Test whether two contexts are equivalent, i.e. whether they
1069 * have both been cloned from the same version of the same context
1070 * and they both have the same number of enabled events.
1071 * If the number of enabled events is the same, then the set
1072 * of enabled events should be the same, because these are both
1073 * inherited contexts, therefore we can't access individual events
1074 * in them directly with an fd; we can only enable/disable all
1075 * events via prctl, or enable/disable all events in a family
1076 * via ioctl, which will have the same effect on both contexts.
1078 static int context_equiv(struct perf_event_context
*ctx1
,
1079 struct perf_event_context
*ctx2
)
1081 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1082 && ctx1
->parent_gen
== ctx2
->parent_gen
1083 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1086 static void __perf_event_sync_stat(struct perf_event
*event
,
1087 struct perf_event
*next_event
)
1091 if (!event
->attr
.inherit_stat
)
1095 * Update the event value, we cannot use perf_event_read()
1096 * because we're in the middle of a context switch and have IRQs
1097 * disabled, which upsets smp_call_function_single(), however
1098 * we know the event must be on the current CPU, therefore we
1099 * don't need to use it.
1101 switch (event
->state
) {
1102 case PERF_EVENT_STATE_ACTIVE
:
1103 event
->pmu
->read(event
);
1106 case PERF_EVENT_STATE_INACTIVE
:
1107 update_event_times(event
);
1115 * In order to keep per-task stats reliable we need to flip the event
1116 * values when we flip the contexts.
1118 value
= atomic64_read(&next_event
->count
);
1119 value
= atomic64_xchg(&event
->count
, value
);
1120 atomic64_set(&next_event
->count
, value
);
1122 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1123 swap(event
->total_time_running
, next_event
->total_time_running
);
1126 * Since we swizzled the values, update the user visible data too.
1128 perf_event_update_userpage(event
);
1129 perf_event_update_userpage(next_event
);
1132 #define list_next_entry(pos, member) \
1133 list_entry(pos->member.next, typeof(*pos), member)
1135 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1136 struct perf_event_context
*next_ctx
)
1138 struct perf_event
*event
, *next_event
;
1143 update_context_time(ctx
);
1145 event
= list_first_entry(&ctx
->event_list
,
1146 struct perf_event
, event_entry
);
1148 next_event
= list_first_entry(&next_ctx
->event_list
,
1149 struct perf_event
, event_entry
);
1151 while (&event
->event_entry
!= &ctx
->event_list
&&
1152 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1154 __perf_event_sync_stat(event
, next_event
);
1156 event
= list_next_entry(event
, event_entry
);
1157 next_event
= list_next_entry(next_event
, event_entry
);
1162 * Called from scheduler to remove the events of the current task,
1163 * with interrupts disabled.
1165 * We stop each event and update the event value in event->count.
1167 * This does not protect us against NMI, but disable()
1168 * sets the disabled bit in the control field of event _before_
1169 * accessing the event control register. If a NMI hits, then it will
1170 * not restart the event.
1172 void perf_event_task_sched_out(struct task_struct
*task
,
1173 struct task_struct
*next
)
1175 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1176 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1177 struct perf_event_context
*next_ctx
;
1178 struct perf_event_context
*parent
;
1181 perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES
, 1, 1, NULL
, 0);
1183 if (likely(!ctx
|| !cpuctx
->task_ctx
))
1187 parent
= rcu_dereference(ctx
->parent_ctx
);
1188 next_ctx
= next
->perf_event_ctxp
;
1189 if (parent
&& next_ctx
&&
1190 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1192 * Looks like the two contexts are clones, so we might be
1193 * able to optimize the context switch. We lock both
1194 * contexts and check that they are clones under the
1195 * lock (including re-checking that neither has been
1196 * uncloned in the meantime). It doesn't matter which
1197 * order we take the locks because no other cpu could
1198 * be trying to lock both of these tasks.
1200 raw_spin_lock(&ctx
->lock
);
1201 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1202 if (context_equiv(ctx
, next_ctx
)) {
1204 * XXX do we need a memory barrier of sorts
1205 * wrt to rcu_dereference() of perf_event_ctxp
1207 task
->perf_event_ctxp
= next_ctx
;
1208 next
->perf_event_ctxp
= ctx
;
1210 next_ctx
->task
= task
;
1213 perf_event_sync_stat(ctx
, next_ctx
);
1215 raw_spin_unlock(&next_ctx
->lock
);
1216 raw_spin_unlock(&ctx
->lock
);
1221 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1222 cpuctx
->task_ctx
= NULL
;
1226 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1227 enum event_type_t event_type
)
1229 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1231 if (!cpuctx
->task_ctx
)
1234 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1237 ctx_sched_out(ctx
, cpuctx
, event_type
);
1238 cpuctx
->task_ctx
= NULL
;
1242 * Called with IRQs disabled
1244 static void __perf_event_task_sched_out(struct perf_event_context
*ctx
)
1246 task_ctx_sched_out(ctx
, EVENT_ALL
);
1250 * Called with IRQs disabled
1252 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1253 enum event_type_t event_type
)
1255 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1259 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1260 struct perf_cpu_context
*cpuctx
)
1262 struct perf_event
*event
;
1264 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1265 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1267 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1270 if (group_can_go_on(event
, cpuctx
, 1))
1271 group_sched_in(event
, cpuctx
, ctx
);
1274 * If this pinned group hasn't been scheduled,
1275 * put it in error state.
1277 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1278 update_group_times(event
);
1279 event
->state
= PERF_EVENT_STATE_ERROR
;
1285 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
1286 struct perf_cpu_context
*cpuctx
)
1288 struct perf_event
*event
;
1291 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1292 /* Ignore events in OFF or ERROR state */
1293 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1296 * Listen to the 'cpu' scheduling filter constraint
1299 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1302 if (group_can_go_on(event
, cpuctx
, can_add_hw
))
1303 if (group_sched_in(event
, cpuctx
, ctx
))
1309 ctx_sched_in(struct perf_event_context
*ctx
,
1310 struct perf_cpu_context
*cpuctx
,
1311 enum event_type_t event_type
)
1313 raw_spin_lock(&ctx
->lock
);
1315 if (likely(!ctx
->nr_events
))
1318 ctx
->timestamp
= perf_clock();
1323 * First go through the list and put on any pinned groups
1324 * in order to give them the best chance of going on.
1326 if (event_type
& EVENT_PINNED
)
1327 ctx_pinned_sched_in(ctx
, cpuctx
);
1329 /* Then walk through the lower prio flexible groups */
1330 if (event_type
& EVENT_FLEXIBLE
)
1331 ctx_flexible_sched_in(ctx
, cpuctx
);
1335 raw_spin_unlock(&ctx
->lock
);
1338 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
1339 enum event_type_t event_type
)
1341 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
1343 ctx_sched_in(ctx
, cpuctx
, event_type
);
1346 static void task_ctx_sched_in(struct task_struct
*task
,
1347 enum event_type_t event_type
)
1349 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1350 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1354 if (cpuctx
->task_ctx
== ctx
)
1356 ctx_sched_in(ctx
, cpuctx
, event_type
);
1357 cpuctx
->task_ctx
= ctx
;
1360 * Called from scheduler to add the events of the current task
1361 * with interrupts disabled.
1363 * We restore the event value and then enable it.
1365 * This does not protect us against NMI, but enable()
1366 * sets the enabled bit in the control field of event _before_
1367 * accessing the event control register. If a NMI hits, then it will
1368 * keep the event running.
1370 void perf_event_task_sched_in(struct task_struct
*task
)
1372 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1373 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1378 if (cpuctx
->task_ctx
== ctx
)
1384 * We want to keep the following priority order:
1385 * cpu pinned (that don't need to move), task pinned,
1386 * cpu flexible, task flexible.
1388 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1390 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
);
1391 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1392 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
);
1394 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);
1542 event
->pmu
->unthrottle(event
);
1546 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
1550 event
->pmu
->read(event
);
1551 now
= atomic64_read(&event
->count
);
1552 delta
= now
- hwc
->freq_count_stamp
;
1553 hwc
->freq_count_stamp
= now
;
1556 perf_adjust_period(event
, TICK_NSEC
, delta
);
1559 raw_spin_unlock(&ctx
->lock
);
1563 * Round-robin a context's events:
1565 static void rotate_ctx(struct perf_event_context
*ctx
)
1567 raw_spin_lock(&ctx
->lock
);
1569 /* Rotate the first entry last of non-pinned groups */
1570 list_rotate_left(&ctx
->flexible_groups
);
1572 raw_spin_unlock(&ctx
->lock
);
1575 void perf_event_task_tick(struct task_struct
*curr
)
1577 struct perf_cpu_context
*cpuctx
;
1578 struct perf_event_context
*ctx
;
1581 if (!atomic_read(&nr_events
))
1584 cpuctx
= &__get_cpu_var(perf_cpu_context
);
1585 if (cpuctx
->ctx
.nr_events
&&
1586 cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
1589 ctx
= curr
->perf_event_ctxp
;
1590 if (ctx
&& ctx
->nr_events
&& ctx
->nr_events
!= ctx
->nr_active
)
1593 perf_ctx_adjust_freq(&cpuctx
->ctx
);
1595 perf_ctx_adjust_freq(ctx
);
1601 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1603 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
1605 rotate_ctx(&cpuctx
->ctx
);
1609 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1611 task_ctx_sched_in(curr
, EVENT_FLEXIBLE
);
1615 static int event_enable_on_exec(struct perf_event
*event
,
1616 struct perf_event_context
*ctx
)
1618 if (!event
->attr
.enable_on_exec
)
1621 event
->attr
.enable_on_exec
= 0;
1622 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1625 __perf_event_mark_enabled(event
, ctx
);
1631 * Enable all of a task's events that have been marked enable-on-exec.
1632 * This expects task == current.
1634 static void perf_event_enable_on_exec(struct task_struct
*task
)
1636 struct perf_event_context
*ctx
;
1637 struct perf_event
*event
;
1638 unsigned long flags
;
1642 local_irq_save(flags
);
1643 ctx
= task
->perf_event_ctxp
;
1644 if (!ctx
|| !ctx
->nr_events
)
1647 __perf_event_task_sched_out(ctx
);
1649 raw_spin_lock(&ctx
->lock
);
1651 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1652 ret
= event_enable_on_exec(event
, ctx
);
1657 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1658 ret
= event_enable_on_exec(event
, ctx
);
1664 * Unclone this context if we enabled any event.
1669 raw_spin_unlock(&ctx
->lock
);
1671 perf_event_task_sched_in(task
);
1673 local_irq_restore(flags
);
1677 * Cross CPU call to read the hardware event
1679 static void __perf_event_read(void *info
)
1681 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1682 struct perf_event
*event
= info
;
1683 struct perf_event_context
*ctx
= event
->ctx
;
1686 * If this is a task context, we need to check whether it is
1687 * the current task context of this cpu. If not it has been
1688 * scheduled out before the smp call arrived. In that case
1689 * event->count would have been updated to a recent sample
1690 * when the event was scheduled out.
1692 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1695 raw_spin_lock(&ctx
->lock
);
1696 update_context_time(ctx
);
1697 update_event_times(event
);
1698 raw_spin_unlock(&ctx
->lock
);
1700 event
->pmu
->read(event
);
1703 static u64
perf_event_read(struct perf_event
*event
)
1706 * If event is enabled and currently active on a CPU, update the
1707 * value in the event structure:
1709 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1710 smp_call_function_single(event
->oncpu
,
1711 __perf_event_read
, event
, 1);
1712 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1713 struct perf_event_context
*ctx
= event
->ctx
;
1714 unsigned long flags
;
1716 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1717 update_context_time(ctx
);
1718 update_event_times(event
);
1719 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1722 return atomic64_read(&event
->count
);
1726 * Initialize the perf_event context in a task_struct:
1729 __perf_event_init_context(struct perf_event_context
*ctx
,
1730 struct task_struct
*task
)
1732 raw_spin_lock_init(&ctx
->lock
);
1733 mutex_init(&ctx
->mutex
);
1734 INIT_LIST_HEAD(&ctx
->pinned_groups
);
1735 INIT_LIST_HEAD(&ctx
->flexible_groups
);
1736 INIT_LIST_HEAD(&ctx
->event_list
);
1737 atomic_set(&ctx
->refcount
, 1);
1741 static struct perf_event_context
*find_get_context(pid_t pid
, int cpu
)
1743 struct perf_event_context
*ctx
;
1744 struct perf_cpu_context
*cpuctx
;
1745 struct task_struct
*task
;
1746 unsigned long flags
;
1749 if (pid
== -1 && cpu
!= -1) {
1750 /* Must be root to operate on a CPU event: */
1751 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
1752 return ERR_PTR(-EACCES
);
1754 if (cpu
< 0 || cpu
>= nr_cpumask_bits
)
1755 return ERR_PTR(-EINVAL
);
1758 * We could be clever and allow to attach a event to an
1759 * offline CPU and activate it when the CPU comes up, but
1762 if (!cpu_online(cpu
))
1763 return ERR_PTR(-ENODEV
);
1765 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1776 task
= find_task_by_vpid(pid
);
1778 get_task_struct(task
);
1782 return ERR_PTR(-ESRCH
);
1785 * Can't attach events to a dying task.
1788 if (task
->flags
& PF_EXITING
)
1791 /* Reuse ptrace permission checks for now. */
1793 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
1797 ctx
= perf_lock_task_context(task
, &flags
);
1800 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1804 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
1808 __perf_event_init_context(ctx
, task
);
1810 if (cmpxchg(&task
->perf_event_ctxp
, NULL
, ctx
)) {
1812 * We raced with some other task; use
1813 * the context they set.
1818 get_task_struct(task
);
1821 put_task_struct(task
);
1825 put_task_struct(task
);
1826 return ERR_PTR(err
);
1829 static void perf_event_free_filter(struct perf_event
*event
);
1831 static void free_event_rcu(struct rcu_head
*head
)
1833 struct perf_event
*event
;
1835 event
= container_of(head
, struct perf_event
, rcu_head
);
1837 put_pid_ns(event
->ns
);
1838 perf_event_free_filter(event
);
1842 static void perf_pending_sync(struct perf_event
*event
);
1844 static void free_event(struct perf_event
*event
)
1846 perf_pending_sync(event
);
1848 if (!event
->parent
) {
1849 atomic_dec(&nr_events
);
1850 if (event
->attr
.mmap
)
1851 atomic_dec(&nr_mmap_events
);
1852 if (event
->attr
.comm
)
1853 atomic_dec(&nr_comm_events
);
1854 if (event
->attr
.task
)
1855 atomic_dec(&nr_task_events
);
1858 if (event
->output
) {
1859 fput(event
->output
->filp
);
1860 event
->output
= NULL
;
1864 event
->destroy(event
);
1866 put_ctx(event
->ctx
);
1867 call_rcu(&event
->rcu_head
, free_event_rcu
);
1870 int perf_event_release_kernel(struct perf_event
*event
)
1872 struct perf_event_context
*ctx
= event
->ctx
;
1874 event
->state
= PERF_EVENT_STATE_FREE
;
1876 WARN_ON_ONCE(ctx
->parent_ctx
);
1878 * There are two ways this annotation is useful:
1880 * 1) there is a lock recursion from perf_event_exit_task
1881 * see the comment there.
1883 * 2) there is a lock-inversion with mmap_sem through
1884 * perf_event_read_group(), which takes faults while
1885 * holding ctx->mutex, however this is called after
1886 * the last filedesc died, so there is no possibility
1887 * to trigger the AB-BA case.
1889 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
1890 perf_event_remove_from_context(event
);
1891 mutex_unlock(&ctx
->mutex
);
1893 mutex_lock(&event
->owner
->perf_event_mutex
);
1894 list_del_init(&event
->owner_entry
);
1895 mutex_unlock(&event
->owner
->perf_event_mutex
);
1896 put_task_struct(event
->owner
);
1902 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
1905 * Called when the last reference to the file is gone.
1907 static int perf_release(struct inode
*inode
, struct file
*file
)
1909 struct perf_event
*event
= file
->private_data
;
1911 file
->private_data
= NULL
;
1913 return perf_event_release_kernel(event
);
1916 static int perf_event_read_size(struct perf_event
*event
)
1918 int entry
= sizeof(u64
); /* value */
1922 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1923 size
+= sizeof(u64
);
1925 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1926 size
+= sizeof(u64
);
1928 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1929 entry
+= sizeof(u64
);
1931 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1932 nr
+= event
->group_leader
->nr_siblings
;
1933 size
+= sizeof(u64
);
1941 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
1943 struct perf_event
*child
;
1949 mutex_lock(&event
->child_mutex
);
1950 total
+= perf_event_read(event
);
1951 *enabled
+= event
->total_time_enabled
+
1952 atomic64_read(&event
->child_total_time_enabled
);
1953 *running
+= event
->total_time_running
+
1954 atomic64_read(&event
->child_total_time_running
);
1956 list_for_each_entry(child
, &event
->child_list
, child_list
) {
1957 total
+= perf_event_read(child
);
1958 *enabled
+= child
->total_time_enabled
;
1959 *running
+= child
->total_time_running
;
1961 mutex_unlock(&event
->child_mutex
);
1965 EXPORT_SYMBOL_GPL(perf_event_read_value
);
1967 static int perf_event_read_group(struct perf_event
*event
,
1968 u64 read_format
, char __user
*buf
)
1970 struct perf_event
*leader
= event
->group_leader
, *sub
;
1971 int n
= 0, size
= 0, ret
= -EFAULT
;
1972 struct perf_event_context
*ctx
= leader
->ctx
;
1974 u64 count
, enabled
, running
;
1976 mutex_lock(&ctx
->mutex
);
1977 count
= perf_event_read_value(leader
, &enabled
, &running
);
1979 values
[n
++] = 1 + leader
->nr_siblings
;
1980 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1981 values
[n
++] = enabled
;
1982 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1983 values
[n
++] = running
;
1984 values
[n
++] = count
;
1985 if (read_format
& PERF_FORMAT_ID
)
1986 values
[n
++] = primary_event_id(leader
);
1988 size
= n
* sizeof(u64
);
1990 if (copy_to_user(buf
, values
, size
))
1995 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
1998 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
1999 if (read_format
& PERF_FORMAT_ID
)
2000 values
[n
++] = primary_event_id(sub
);
2002 size
= n
* sizeof(u64
);
2004 if (copy_to_user(buf
+ ret
, values
, size
)) {
2012 mutex_unlock(&ctx
->mutex
);
2017 static int perf_event_read_one(struct perf_event
*event
,
2018 u64 read_format
, char __user
*buf
)
2020 u64 enabled
, running
;
2024 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
2025 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2026 values
[n
++] = enabled
;
2027 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2028 values
[n
++] = running
;
2029 if (read_format
& PERF_FORMAT_ID
)
2030 values
[n
++] = primary_event_id(event
);
2032 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2035 return n
* sizeof(u64
);
2039 * Read the performance event - simple non blocking version for now
2042 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2044 u64 read_format
= event
->attr
.read_format
;
2048 * Return end-of-file for a read on a event that is in
2049 * error state (i.e. because it was pinned but it couldn't be
2050 * scheduled on to the CPU at some point).
2052 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2055 if (count
< perf_event_read_size(event
))
2058 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2059 if (read_format
& PERF_FORMAT_GROUP
)
2060 ret
= perf_event_read_group(event
, read_format
, buf
);
2062 ret
= perf_event_read_one(event
, read_format
, buf
);
2068 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2070 struct perf_event
*event
= file
->private_data
;
2072 return perf_read_hw(event
, buf
, count
);
2075 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2077 struct perf_event
*event
= file
->private_data
;
2078 struct perf_mmap_data
*data
;
2079 unsigned int events
= POLL_HUP
;
2082 data
= rcu_dereference(event
->data
);
2084 events
= atomic_xchg(&data
->poll
, 0);
2087 poll_wait(file
, &event
->waitq
, wait
);
2092 static void perf_event_reset(struct perf_event
*event
)
2094 (void)perf_event_read(event
);
2095 atomic64_set(&event
->count
, 0);
2096 perf_event_update_userpage(event
);
2100 * Holding the top-level event's child_mutex means that any
2101 * descendant process that has inherited this event will block
2102 * in sync_child_event if it goes to exit, thus satisfying the
2103 * task existence requirements of perf_event_enable/disable.
2105 static void perf_event_for_each_child(struct perf_event
*event
,
2106 void (*func
)(struct perf_event
*))
2108 struct perf_event
*child
;
2110 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2111 mutex_lock(&event
->child_mutex
);
2113 list_for_each_entry(child
, &event
->child_list
, child_list
)
2115 mutex_unlock(&event
->child_mutex
);
2118 static void perf_event_for_each(struct perf_event
*event
,
2119 void (*func
)(struct perf_event
*))
2121 struct perf_event_context
*ctx
= event
->ctx
;
2122 struct perf_event
*sibling
;
2124 WARN_ON_ONCE(ctx
->parent_ctx
);
2125 mutex_lock(&ctx
->mutex
);
2126 event
= event
->group_leader
;
2128 perf_event_for_each_child(event
, func
);
2130 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
2131 perf_event_for_each_child(event
, func
);
2132 mutex_unlock(&ctx
->mutex
);
2135 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
2137 struct perf_event_context
*ctx
= event
->ctx
;
2142 if (!event
->attr
.sample_period
)
2145 size
= copy_from_user(&value
, arg
, sizeof(value
));
2146 if (size
!= sizeof(value
))
2152 raw_spin_lock_irq(&ctx
->lock
);
2153 if (event
->attr
.freq
) {
2154 if (value
> sysctl_perf_event_sample_rate
) {
2159 event
->attr
.sample_freq
= value
;
2161 event
->attr
.sample_period
= value
;
2162 event
->hw
.sample_period
= value
;
2165 raw_spin_unlock_irq(&ctx
->lock
);
2170 static int perf_event_set_output(struct perf_event
*event
, int output_fd
);
2171 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
2173 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2175 struct perf_event
*event
= file
->private_data
;
2176 void (*func
)(struct perf_event
*);
2180 case PERF_EVENT_IOC_ENABLE
:
2181 func
= perf_event_enable
;
2183 case PERF_EVENT_IOC_DISABLE
:
2184 func
= perf_event_disable
;
2186 case PERF_EVENT_IOC_RESET
:
2187 func
= perf_event_reset
;
2190 case PERF_EVENT_IOC_REFRESH
:
2191 return perf_event_refresh(event
, arg
);
2193 case PERF_EVENT_IOC_PERIOD
:
2194 return perf_event_period(event
, (u64 __user
*)arg
);
2196 case PERF_EVENT_IOC_SET_OUTPUT
:
2197 return perf_event_set_output(event
, arg
);
2199 case PERF_EVENT_IOC_SET_FILTER
:
2200 return perf_event_set_filter(event
, (void __user
*)arg
);
2206 if (flags
& PERF_IOC_FLAG_GROUP
)
2207 perf_event_for_each(event
, func
);
2209 perf_event_for_each_child(event
, func
);
2214 int perf_event_task_enable(void)
2216 struct perf_event
*event
;
2218 mutex_lock(¤t
->perf_event_mutex
);
2219 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2220 perf_event_for_each_child(event
, perf_event_enable
);
2221 mutex_unlock(¤t
->perf_event_mutex
);
2226 int perf_event_task_disable(void)
2228 struct perf_event
*event
;
2230 mutex_lock(¤t
->perf_event_mutex
);
2231 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2232 perf_event_for_each_child(event
, perf_event_disable
);
2233 mutex_unlock(¤t
->perf_event_mutex
);
2238 #ifndef PERF_EVENT_INDEX_OFFSET
2239 # define PERF_EVENT_INDEX_OFFSET 0
2242 static int perf_event_index(struct perf_event
*event
)
2244 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2247 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
2251 * Callers need to ensure there can be no nesting of this function, otherwise
2252 * the seqlock logic goes bad. We can not serialize this because the arch
2253 * code calls this from NMI context.
2255 void perf_event_update_userpage(struct perf_event
*event
)
2257 struct perf_event_mmap_page
*userpg
;
2258 struct perf_mmap_data
*data
;
2261 data
= rcu_dereference(event
->data
);
2265 userpg
= data
->user_page
;
2268 * Disable preemption so as to not let the corresponding user-space
2269 * spin too long if we get preempted.
2274 userpg
->index
= perf_event_index(event
);
2275 userpg
->offset
= atomic64_read(&event
->count
);
2276 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2277 userpg
->offset
-= atomic64_read(&event
->hw
.prev_count
);
2279 userpg
->time_enabled
= event
->total_time_enabled
+
2280 atomic64_read(&event
->child_total_time_enabled
);
2282 userpg
->time_running
= event
->total_time_running
+
2283 atomic64_read(&event
->child_total_time_running
);
2292 static unsigned long perf_data_size(struct perf_mmap_data
*data
)
2294 return data
->nr_pages
<< (PAGE_SHIFT
+ data
->data_order
);
2297 #ifndef CONFIG_PERF_USE_VMALLOC
2300 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
2303 static struct page
*
2304 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2306 if (pgoff
> data
->nr_pages
)
2310 return virt_to_page(data
->user_page
);
2312 return virt_to_page(data
->data_pages
[pgoff
- 1]);
2315 static struct perf_mmap_data
*
2316 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2318 struct perf_mmap_data
*data
;
2322 WARN_ON(atomic_read(&event
->mmap_count
));
2324 size
= sizeof(struct perf_mmap_data
);
2325 size
+= nr_pages
* sizeof(void *);
2327 data
= kzalloc(size
, GFP_KERNEL
);
2331 data
->user_page
= (void *)get_zeroed_page(GFP_KERNEL
);
2332 if (!data
->user_page
)
2333 goto fail_user_page
;
2335 for (i
= 0; i
< nr_pages
; i
++) {
2336 data
->data_pages
[i
] = (void *)get_zeroed_page(GFP_KERNEL
);
2337 if (!data
->data_pages
[i
])
2338 goto fail_data_pages
;
2341 data
->data_order
= 0;
2342 data
->nr_pages
= nr_pages
;
2347 for (i
--; i
>= 0; i
--)
2348 free_page((unsigned long)data
->data_pages
[i
]);
2350 free_page((unsigned long)data
->user_page
);
2359 static void perf_mmap_free_page(unsigned long addr
)
2361 struct page
*page
= virt_to_page((void *)addr
);
2363 page
->mapping
= NULL
;
2367 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2371 perf_mmap_free_page((unsigned long)data
->user_page
);
2372 for (i
= 0; i
< data
->nr_pages
; i
++)
2373 perf_mmap_free_page((unsigned long)data
->data_pages
[i
]);
2380 * Back perf_mmap() with vmalloc memory.
2382 * Required for architectures that have d-cache aliasing issues.
2385 static struct page
*
2386 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2388 if (pgoff
> (1UL << data
->data_order
))
2391 return vmalloc_to_page((void *)data
->user_page
+ pgoff
* PAGE_SIZE
);
2394 static void perf_mmap_unmark_page(void *addr
)
2396 struct page
*page
= vmalloc_to_page(addr
);
2398 page
->mapping
= NULL
;
2401 static void perf_mmap_data_free_work(struct work_struct
*work
)
2403 struct perf_mmap_data
*data
;
2407 data
= container_of(work
, struct perf_mmap_data
, work
);
2408 nr
= 1 << data
->data_order
;
2410 base
= data
->user_page
;
2411 for (i
= 0; i
< nr
+ 1; i
++)
2412 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
2418 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2420 schedule_work(&data
->work
);
2423 static struct perf_mmap_data
*
2424 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2426 struct perf_mmap_data
*data
;
2430 WARN_ON(atomic_read(&event
->mmap_count
));
2432 size
= sizeof(struct perf_mmap_data
);
2433 size
+= sizeof(void *);
2435 data
= kzalloc(size
, GFP_KERNEL
);
2439 INIT_WORK(&data
->work
, perf_mmap_data_free_work
);
2441 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
2445 data
->user_page
= all_buf
;
2446 data
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
2447 data
->data_order
= ilog2(nr_pages
);
2461 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
2463 struct perf_event
*event
= vma
->vm_file
->private_data
;
2464 struct perf_mmap_data
*data
;
2465 int ret
= VM_FAULT_SIGBUS
;
2467 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
2468 if (vmf
->pgoff
== 0)
2474 data
= rcu_dereference(event
->data
);
2478 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
2481 vmf
->page
= perf_mmap_to_page(data
, vmf
->pgoff
);
2485 get_page(vmf
->page
);
2486 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
2487 vmf
->page
->index
= vmf
->pgoff
;
2497 perf_mmap_data_init(struct perf_event
*event
, struct perf_mmap_data
*data
)
2499 long max_size
= perf_data_size(data
);
2501 atomic_set(&data
->lock
, -1);
2503 if (event
->attr
.watermark
) {
2504 data
->watermark
= min_t(long, max_size
,
2505 event
->attr
.wakeup_watermark
);
2508 if (!data
->watermark
)
2509 data
->watermark
= max_size
/ 2;
2512 rcu_assign_pointer(event
->data
, data
);
2515 static void perf_mmap_data_free_rcu(struct rcu_head
*rcu_head
)
2517 struct perf_mmap_data
*data
;
2519 data
= container_of(rcu_head
, struct perf_mmap_data
, rcu_head
);
2520 perf_mmap_data_free(data
);
2523 static void perf_mmap_data_release(struct perf_event
*event
)
2525 struct perf_mmap_data
*data
= event
->data
;
2527 WARN_ON(atomic_read(&event
->mmap_count
));
2529 rcu_assign_pointer(event
->data
, NULL
);
2530 call_rcu(&data
->rcu_head
, perf_mmap_data_free_rcu
);
2533 static void perf_mmap_open(struct vm_area_struct
*vma
)
2535 struct perf_event
*event
= vma
->vm_file
->private_data
;
2537 atomic_inc(&event
->mmap_count
);
2540 static void perf_mmap_close(struct vm_area_struct
*vma
)
2542 struct perf_event
*event
= vma
->vm_file
->private_data
;
2544 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2545 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
2546 unsigned long size
= perf_data_size(event
->data
);
2547 struct user_struct
*user
= current_user();
2549 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
2550 vma
->vm_mm
->locked_vm
-= event
->data
->nr_locked
;
2551 perf_mmap_data_release(event
);
2552 mutex_unlock(&event
->mmap_mutex
);
2556 static const struct vm_operations_struct perf_mmap_vmops
= {
2557 .open
= perf_mmap_open
,
2558 .close
= perf_mmap_close
,
2559 .fault
= perf_mmap_fault
,
2560 .page_mkwrite
= perf_mmap_fault
,
2563 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
2565 struct perf_event
*event
= file
->private_data
;
2566 unsigned long user_locked
, user_lock_limit
;
2567 struct user_struct
*user
= current_user();
2568 unsigned long locked
, lock_limit
;
2569 struct perf_mmap_data
*data
;
2570 unsigned long vma_size
;
2571 unsigned long nr_pages
;
2572 long user_extra
, extra
;
2575 if (!(vma
->vm_flags
& VM_SHARED
))
2578 vma_size
= vma
->vm_end
- vma
->vm_start
;
2579 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
2582 * If we have data pages ensure they're a power-of-two number, so we
2583 * can do bitmasks instead of modulo.
2585 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
2588 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
2591 if (vma
->vm_pgoff
!= 0)
2594 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2595 mutex_lock(&event
->mmap_mutex
);
2596 if (event
->output
) {
2601 if (atomic_inc_not_zero(&event
->mmap_count
)) {
2602 if (nr_pages
!= event
->data
->nr_pages
)
2607 user_extra
= nr_pages
+ 1;
2608 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
2611 * Increase the limit linearly with more CPUs:
2613 user_lock_limit
*= num_online_cpus();
2615 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
2618 if (user_locked
> user_lock_limit
)
2619 extra
= user_locked
- user_lock_limit
;
2621 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
2622 lock_limit
>>= PAGE_SHIFT
;
2623 locked
= vma
->vm_mm
->locked_vm
+ extra
;
2625 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
2626 !capable(CAP_IPC_LOCK
)) {
2631 WARN_ON(event
->data
);
2633 data
= perf_mmap_data_alloc(event
, nr_pages
);
2639 perf_mmap_data_init(event
, data
);
2641 atomic_set(&event
->mmap_count
, 1);
2642 atomic_long_add(user_extra
, &user
->locked_vm
);
2643 vma
->vm_mm
->locked_vm
+= extra
;
2644 event
->data
->nr_locked
= extra
;
2645 if (vma
->vm_flags
& VM_WRITE
)
2646 event
->data
->writable
= 1;
2649 mutex_unlock(&event
->mmap_mutex
);
2651 vma
->vm_flags
|= VM_RESERVED
;
2652 vma
->vm_ops
= &perf_mmap_vmops
;
2657 static int perf_fasync(int fd
, struct file
*filp
, int on
)
2659 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
2660 struct perf_event
*event
= filp
->private_data
;
2663 mutex_lock(&inode
->i_mutex
);
2664 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
2665 mutex_unlock(&inode
->i_mutex
);
2673 static const struct file_operations perf_fops
= {
2674 .llseek
= no_llseek
,
2675 .release
= perf_release
,
2678 .unlocked_ioctl
= perf_ioctl
,
2679 .compat_ioctl
= perf_ioctl
,
2681 .fasync
= perf_fasync
,
2687 * If there's data, ensure we set the poll() state and publish everything
2688 * to user-space before waking everybody up.
2691 void perf_event_wakeup(struct perf_event
*event
)
2693 wake_up_all(&event
->waitq
);
2695 if (event
->pending_kill
) {
2696 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
2697 event
->pending_kill
= 0;
2704 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
2706 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
2707 * single linked list and use cmpxchg() to add entries lockless.
2710 static void perf_pending_event(struct perf_pending_entry
*entry
)
2712 struct perf_event
*event
= container_of(entry
,
2713 struct perf_event
, pending
);
2715 if (event
->pending_disable
) {
2716 event
->pending_disable
= 0;
2717 __perf_event_disable(event
);
2720 if (event
->pending_wakeup
) {
2721 event
->pending_wakeup
= 0;
2722 perf_event_wakeup(event
);
2726 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
2728 static DEFINE_PER_CPU(struct perf_pending_entry
*, perf_pending_head
) = {
2732 static void perf_pending_queue(struct perf_pending_entry
*entry
,
2733 void (*func
)(struct perf_pending_entry
*))
2735 struct perf_pending_entry
**head
;
2737 if (cmpxchg(&entry
->next
, NULL
, PENDING_TAIL
) != NULL
)
2742 head
= &get_cpu_var(perf_pending_head
);
2745 entry
->next
= *head
;
2746 } while (cmpxchg(head
, entry
->next
, entry
) != entry
->next
);
2748 set_perf_event_pending();
2750 put_cpu_var(perf_pending_head
);
2753 static int __perf_pending_run(void)
2755 struct perf_pending_entry
*list
;
2758 list
= xchg(&__get_cpu_var(perf_pending_head
), PENDING_TAIL
);
2759 while (list
!= PENDING_TAIL
) {
2760 void (*func
)(struct perf_pending_entry
*);
2761 struct perf_pending_entry
*entry
= list
;
2768 * Ensure we observe the unqueue before we issue the wakeup,
2769 * so that we won't be waiting forever.
2770 * -- see perf_not_pending().
2781 static inline int perf_not_pending(struct perf_event
*event
)
2784 * If we flush on whatever cpu we run, there is a chance we don't
2788 __perf_pending_run();
2792 * Ensure we see the proper queue state before going to sleep
2793 * so that we do not miss the wakeup. -- see perf_pending_handle()
2796 return event
->pending
.next
== NULL
;
2799 static void perf_pending_sync(struct perf_event
*event
)
2801 wait_event(event
->waitq
, perf_not_pending(event
));
2804 void perf_event_do_pending(void)
2806 __perf_pending_run();
2810 * Callchain support -- arch specific
2813 __weak
struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2819 void perf_arch_fetch_caller_regs(struct pt_regs
*regs
, unsigned long ip
, int skip
)
2825 * We assume there is only KVM supporting the callbacks.
2826 * Later on, we might change it to a list if there is
2827 * another virtualization implementation supporting the callbacks.
2829 struct perf_guest_info_callbacks
*perf_guest_cbs
;
2831 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
2833 perf_guest_cbs
= cbs
;
2836 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
2838 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
2840 perf_guest_cbs
= NULL
;
2843 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
2848 static bool perf_output_space(struct perf_mmap_data
*data
, unsigned long tail
,
2849 unsigned long offset
, unsigned long head
)
2853 if (!data
->writable
)
2856 mask
= perf_data_size(data
) - 1;
2858 offset
= (offset
- tail
) & mask
;
2859 head
= (head
- tail
) & mask
;
2861 if ((int)(head
- offset
) < 0)
2867 static void perf_output_wakeup(struct perf_output_handle
*handle
)
2869 atomic_set(&handle
->data
->poll
, POLL_IN
);
2872 handle
->event
->pending_wakeup
= 1;
2873 perf_pending_queue(&handle
->event
->pending
,
2874 perf_pending_event
);
2876 perf_event_wakeup(handle
->event
);
2880 * Curious locking construct.
2882 * We need to ensure a later event_id doesn't publish a head when a former
2883 * event_id isn't done writing. However since we need to deal with NMIs we
2884 * cannot fully serialize things.
2886 * What we do is serialize between CPUs so we only have to deal with NMI
2887 * nesting on a single CPU.
2889 * We only publish the head (and generate a wakeup) when the outer-most
2890 * event_id completes.
2892 static void perf_output_lock(struct perf_output_handle
*handle
)
2894 struct perf_mmap_data
*data
= handle
->data
;
2895 int cur
, cpu
= get_cpu();
2900 cur
= atomic_cmpxchg(&data
->lock
, -1, cpu
);
2912 static void perf_output_unlock(struct perf_output_handle
*handle
)
2914 struct perf_mmap_data
*data
= handle
->data
;
2918 data
->done_head
= data
->head
;
2920 if (!handle
->locked
)
2925 * The xchg implies a full barrier that ensures all writes are done
2926 * before we publish the new head, matched by a rmb() in userspace when
2927 * reading this position.
2929 while ((head
= atomic_long_xchg(&data
->done_head
, 0)))
2930 data
->user_page
->data_head
= head
;
2933 * NMI can happen here, which means we can miss a done_head update.
2936 cpu
= atomic_xchg(&data
->lock
, -1);
2937 WARN_ON_ONCE(cpu
!= smp_processor_id());
2940 * Therefore we have to validate we did not indeed do so.
2942 if (unlikely(atomic_long_read(&data
->done_head
))) {
2944 * Since we had it locked, we can lock it again.
2946 while (atomic_cmpxchg(&data
->lock
, -1, cpu
) != -1)
2952 if (atomic_xchg(&data
->wakeup
, 0))
2953 perf_output_wakeup(handle
);
2958 void perf_output_copy(struct perf_output_handle
*handle
,
2959 const void *buf
, unsigned int len
)
2961 unsigned int pages_mask
;
2962 unsigned long offset
;
2966 offset
= handle
->offset
;
2967 pages_mask
= handle
->data
->nr_pages
- 1;
2968 pages
= handle
->data
->data_pages
;
2971 unsigned long page_offset
;
2972 unsigned long page_size
;
2975 nr
= (offset
>> PAGE_SHIFT
) & pages_mask
;
2976 page_size
= 1UL << (handle
->data
->data_order
+ PAGE_SHIFT
);
2977 page_offset
= offset
& (page_size
- 1);
2978 size
= min_t(unsigned int, page_size
- page_offset
, len
);
2980 memcpy(pages
[nr
] + page_offset
, buf
, size
);
2987 handle
->offset
= offset
;
2990 * Check we didn't copy past our reservation window, taking the
2991 * possible unsigned int wrap into account.
2993 WARN_ON_ONCE(((long)(handle
->head
- handle
->offset
)) < 0);
2996 int perf_output_begin(struct perf_output_handle
*handle
,
2997 struct perf_event
*event
, unsigned int size
,
2998 int nmi
, int sample
)
3000 struct perf_event
*output_event
;
3001 struct perf_mmap_data
*data
;
3002 unsigned long tail
, offset
, head
;
3005 struct perf_event_header header
;
3012 * For inherited events we send all the output towards the parent.
3015 event
= event
->parent
;
3017 output_event
= rcu_dereference(event
->output
);
3019 event
= output_event
;
3021 data
= rcu_dereference(event
->data
);
3025 handle
->data
= data
;
3026 handle
->event
= event
;
3028 handle
->sample
= sample
;
3030 if (!data
->nr_pages
)
3033 have_lost
= atomic_read(&data
->lost
);
3035 size
+= sizeof(lost_event
);
3037 perf_output_lock(handle
);
3041 * Userspace could choose to issue a mb() before updating the
3042 * tail pointer. So that all reads will be completed before the
3045 tail
= ACCESS_ONCE(data
->user_page
->data_tail
);
3047 offset
= head
= atomic_long_read(&data
->head
);
3049 if (unlikely(!perf_output_space(data
, tail
, offset
, head
)))
3051 } while (atomic_long_cmpxchg(&data
->head
, offset
, head
) != offset
);
3053 handle
->offset
= offset
;
3054 handle
->head
= head
;
3056 if (head
- tail
> data
->watermark
)
3057 atomic_set(&data
->wakeup
, 1);
3060 lost_event
.header
.type
= PERF_RECORD_LOST
;
3061 lost_event
.header
.misc
= 0;
3062 lost_event
.header
.size
= sizeof(lost_event
);
3063 lost_event
.id
= event
->id
;
3064 lost_event
.lost
= atomic_xchg(&data
->lost
, 0);
3066 perf_output_put(handle
, lost_event
);
3072 atomic_inc(&data
->lost
);
3073 perf_output_unlock(handle
);
3080 void perf_output_end(struct perf_output_handle
*handle
)
3082 struct perf_event
*event
= handle
->event
;
3083 struct perf_mmap_data
*data
= handle
->data
;
3085 int wakeup_events
= event
->attr
.wakeup_events
;
3087 if (handle
->sample
&& wakeup_events
) {
3088 int events
= atomic_inc_return(&data
->events
);
3089 if (events
>= wakeup_events
) {
3090 atomic_sub(wakeup_events
, &data
->events
);
3091 atomic_set(&data
->wakeup
, 1);
3095 perf_output_unlock(handle
);
3099 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
3102 * only top level events have the pid namespace they were created in
3105 event
= event
->parent
;
3107 return task_tgid_nr_ns(p
, event
->ns
);
3110 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
3113 * only top level events have the pid namespace they were created in
3116 event
= event
->parent
;
3118 return task_pid_nr_ns(p
, event
->ns
);
3121 static void perf_output_read_one(struct perf_output_handle
*handle
,
3122 struct perf_event
*event
)
3124 u64 read_format
= event
->attr
.read_format
;
3128 values
[n
++] = atomic64_read(&event
->count
);
3129 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3130 values
[n
++] = event
->total_time_enabled
+
3131 atomic64_read(&event
->child_total_time_enabled
);
3133 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3134 values
[n
++] = event
->total_time_running
+
3135 atomic64_read(&event
->child_total_time_running
);
3137 if (read_format
& PERF_FORMAT_ID
)
3138 values
[n
++] = primary_event_id(event
);
3140 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3144 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3146 static void perf_output_read_group(struct perf_output_handle
*handle
,
3147 struct perf_event
*event
)
3149 struct perf_event
*leader
= event
->group_leader
, *sub
;
3150 u64 read_format
= event
->attr
.read_format
;
3154 values
[n
++] = 1 + leader
->nr_siblings
;
3156 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3157 values
[n
++] = leader
->total_time_enabled
;
3159 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3160 values
[n
++] = leader
->total_time_running
;
3162 if (leader
!= event
)
3163 leader
->pmu
->read(leader
);
3165 values
[n
++] = atomic64_read(&leader
->count
);
3166 if (read_format
& PERF_FORMAT_ID
)
3167 values
[n
++] = primary_event_id(leader
);
3169 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3171 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3175 sub
->pmu
->read(sub
);
3177 values
[n
++] = atomic64_read(&sub
->count
);
3178 if (read_format
& PERF_FORMAT_ID
)
3179 values
[n
++] = primary_event_id(sub
);
3181 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3185 static void perf_output_read(struct perf_output_handle
*handle
,
3186 struct perf_event
*event
)
3188 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3189 perf_output_read_group(handle
, event
);
3191 perf_output_read_one(handle
, event
);
3194 void perf_output_sample(struct perf_output_handle
*handle
,
3195 struct perf_event_header
*header
,
3196 struct perf_sample_data
*data
,
3197 struct perf_event
*event
)
3199 u64 sample_type
= data
->type
;
3201 perf_output_put(handle
, *header
);
3203 if (sample_type
& PERF_SAMPLE_IP
)
3204 perf_output_put(handle
, data
->ip
);
3206 if (sample_type
& PERF_SAMPLE_TID
)
3207 perf_output_put(handle
, data
->tid_entry
);
3209 if (sample_type
& PERF_SAMPLE_TIME
)
3210 perf_output_put(handle
, data
->time
);
3212 if (sample_type
& PERF_SAMPLE_ADDR
)
3213 perf_output_put(handle
, data
->addr
);
3215 if (sample_type
& PERF_SAMPLE_ID
)
3216 perf_output_put(handle
, data
->id
);
3218 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3219 perf_output_put(handle
, data
->stream_id
);
3221 if (sample_type
& PERF_SAMPLE_CPU
)
3222 perf_output_put(handle
, data
->cpu_entry
);
3224 if (sample_type
& PERF_SAMPLE_PERIOD
)
3225 perf_output_put(handle
, data
->period
);
3227 if (sample_type
& PERF_SAMPLE_READ
)
3228 perf_output_read(handle
, event
);
3230 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3231 if (data
->callchain
) {
3234 if (data
->callchain
)
3235 size
+= data
->callchain
->nr
;
3237 size
*= sizeof(u64
);
3239 perf_output_copy(handle
, data
->callchain
, size
);
3242 perf_output_put(handle
, nr
);
3246 if (sample_type
& PERF_SAMPLE_RAW
) {
3248 perf_output_put(handle
, data
->raw
->size
);
3249 perf_output_copy(handle
, data
->raw
->data
,
3256 .size
= sizeof(u32
),
3259 perf_output_put(handle
, raw
);
3264 void perf_prepare_sample(struct perf_event_header
*header
,
3265 struct perf_sample_data
*data
,
3266 struct perf_event
*event
,
3267 struct pt_regs
*regs
)
3269 u64 sample_type
= event
->attr
.sample_type
;
3271 data
->type
= sample_type
;
3273 header
->type
= PERF_RECORD_SAMPLE
;
3274 header
->size
= sizeof(*header
);
3277 header
->misc
|= perf_misc_flags(regs
);
3279 if (sample_type
& PERF_SAMPLE_IP
) {
3280 data
->ip
= perf_instruction_pointer(regs
);
3282 header
->size
+= sizeof(data
->ip
);
3285 if (sample_type
& PERF_SAMPLE_TID
) {
3286 /* namespace issues */
3287 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3288 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3290 header
->size
+= sizeof(data
->tid_entry
);
3293 if (sample_type
& PERF_SAMPLE_TIME
) {
3294 data
->time
= perf_clock();
3296 header
->size
+= sizeof(data
->time
);
3299 if (sample_type
& PERF_SAMPLE_ADDR
)
3300 header
->size
+= sizeof(data
->addr
);
3302 if (sample_type
& PERF_SAMPLE_ID
) {
3303 data
->id
= primary_event_id(event
);
3305 header
->size
+= sizeof(data
->id
);
3308 if (sample_type
& PERF_SAMPLE_STREAM_ID
) {
3309 data
->stream_id
= event
->id
;
3311 header
->size
+= sizeof(data
->stream_id
);
3314 if (sample_type
& PERF_SAMPLE_CPU
) {
3315 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3316 data
->cpu_entry
.reserved
= 0;
3318 header
->size
+= sizeof(data
->cpu_entry
);
3321 if (sample_type
& PERF_SAMPLE_PERIOD
)
3322 header
->size
+= sizeof(data
->period
);
3324 if (sample_type
& PERF_SAMPLE_READ
)
3325 header
->size
+= perf_event_read_size(event
);
3327 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3330 data
->callchain
= perf_callchain(regs
);
3332 if (data
->callchain
)
3333 size
+= data
->callchain
->nr
;
3335 header
->size
+= size
* sizeof(u64
);
3338 if (sample_type
& PERF_SAMPLE_RAW
) {
3339 int size
= sizeof(u32
);
3342 size
+= data
->raw
->size
;
3344 size
+= sizeof(u32
);
3346 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3347 header
->size
+= size
;
3351 static void perf_event_output(struct perf_event
*event
, int nmi
,
3352 struct perf_sample_data
*data
,
3353 struct pt_regs
*regs
)
3355 struct perf_output_handle handle
;
3356 struct perf_event_header header
;
3358 perf_prepare_sample(&header
, data
, event
, regs
);
3360 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
3363 perf_output_sample(&handle
, &header
, data
, event
);
3365 perf_output_end(&handle
);
3372 struct perf_read_event
{
3373 struct perf_event_header header
;
3380 perf_event_read_event(struct perf_event
*event
,
3381 struct task_struct
*task
)
3383 struct perf_output_handle handle
;
3384 struct perf_read_event read_event
= {
3386 .type
= PERF_RECORD_READ
,
3388 .size
= sizeof(read_event
) + perf_event_read_size(event
),
3390 .pid
= perf_event_pid(event
, task
),
3391 .tid
= perf_event_tid(event
, task
),
3395 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
3399 perf_output_put(&handle
, read_event
);
3400 perf_output_read(&handle
, event
);
3402 perf_output_end(&handle
);
3406 * task tracking -- fork/exit
3408 * enabled by: attr.comm | attr.mmap | attr.task
3411 struct perf_task_event
{
3412 struct task_struct
*task
;
3413 struct perf_event_context
*task_ctx
;
3416 struct perf_event_header header
;
3426 static void perf_event_task_output(struct perf_event
*event
,
3427 struct perf_task_event
*task_event
)
3429 struct perf_output_handle handle
;
3430 struct task_struct
*task
= task_event
->task
;
3431 unsigned long flags
;
3435 * If this CPU attempts to acquire an rq lock held by a CPU spinning
3436 * in perf_output_lock() from interrupt context, it's game over.
3438 local_irq_save(flags
);
3440 size
= task_event
->event_id
.header
.size
;
3441 ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3444 local_irq_restore(flags
);
3448 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
3449 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
3451 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
3452 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
3454 perf_output_put(&handle
, task_event
->event_id
);
3456 perf_output_end(&handle
);
3457 local_irq_restore(flags
);
3460 static int perf_event_task_match(struct perf_event
*event
)
3462 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3465 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3468 if (event
->attr
.comm
|| event
->attr
.mmap
|| event
->attr
.task
)
3474 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
3475 struct perf_task_event
*task_event
)
3477 struct perf_event
*event
;
3479 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3480 if (perf_event_task_match(event
))
3481 perf_event_task_output(event
, task_event
);
3485 static void perf_event_task_event(struct perf_task_event
*task_event
)
3487 struct perf_cpu_context
*cpuctx
;
3488 struct perf_event_context
*ctx
= task_event
->task_ctx
;
3491 cpuctx
= &get_cpu_var(perf_cpu_context
);
3492 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
3494 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3496 perf_event_task_ctx(ctx
, task_event
);
3497 put_cpu_var(perf_cpu_context
);
3501 static void perf_event_task(struct task_struct
*task
,
3502 struct perf_event_context
*task_ctx
,
3505 struct perf_task_event task_event
;
3507 if (!atomic_read(&nr_comm_events
) &&
3508 !atomic_read(&nr_mmap_events
) &&
3509 !atomic_read(&nr_task_events
))
3512 task_event
= (struct perf_task_event
){
3514 .task_ctx
= task_ctx
,
3517 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
3519 .size
= sizeof(task_event
.event_id
),
3525 .time
= perf_clock(),
3529 perf_event_task_event(&task_event
);
3532 void perf_event_fork(struct task_struct
*task
)
3534 perf_event_task(task
, NULL
, 1);
3541 struct perf_comm_event
{
3542 struct task_struct
*task
;
3547 struct perf_event_header header
;
3554 static void perf_event_comm_output(struct perf_event
*event
,
3555 struct perf_comm_event
*comm_event
)
3557 struct perf_output_handle handle
;
3558 int size
= comm_event
->event_id
.header
.size
;
3559 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3564 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
3565 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
3567 perf_output_put(&handle
, comm_event
->event_id
);
3568 perf_output_copy(&handle
, comm_event
->comm
,
3569 comm_event
->comm_size
);
3570 perf_output_end(&handle
);
3573 static int perf_event_comm_match(struct perf_event
*event
)
3575 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3578 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3581 if (event
->attr
.comm
)
3587 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
3588 struct perf_comm_event
*comm_event
)
3590 struct perf_event
*event
;
3592 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3593 if (perf_event_comm_match(event
))
3594 perf_event_comm_output(event
, comm_event
);
3598 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
3600 struct perf_cpu_context
*cpuctx
;
3601 struct perf_event_context
*ctx
;
3603 char comm
[TASK_COMM_LEN
];
3605 memset(comm
, 0, sizeof(comm
));
3606 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
3607 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
3609 comm_event
->comm
= comm
;
3610 comm_event
->comm_size
= size
;
3612 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
3615 cpuctx
= &get_cpu_var(perf_cpu_context
);
3616 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
3617 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3619 perf_event_comm_ctx(ctx
, comm_event
);
3620 put_cpu_var(perf_cpu_context
);
3624 void perf_event_comm(struct task_struct
*task
)
3626 struct perf_comm_event comm_event
;
3628 if (task
->perf_event_ctxp
)
3629 perf_event_enable_on_exec(task
);
3631 if (!atomic_read(&nr_comm_events
))
3634 comm_event
= (struct perf_comm_event
){
3640 .type
= PERF_RECORD_COMM
,
3649 perf_event_comm_event(&comm_event
);
3656 struct perf_mmap_event
{
3657 struct vm_area_struct
*vma
;
3659 const char *file_name
;
3663 struct perf_event_header header
;
3673 static void perf_event_mmap_output(struct perf_event
*event
,
3674 struct perf_mmap_event
*mmap_event
)
3676 struct perf_output_handle handle
;
3677 int size
= mmap_event
->event_id
.header
.size
;
3678 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3683 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
3684 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
3686 perf_output_put(&handle
, mmap_event
->event_id
);
3687 perf_output_copy(&handle
, mmap_event
->file_name
,
3688 mmap_event
->file_size
);
3689 perf_output_end(&handle
);
3692 static int perf_event_mmap_match(struct perf_event
*event
,
3693 struct perf_mmap_event
*mmap_event
)
3695 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3698 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3701 if (event
->attr
.mmap
)
3707 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
3708 struct perf_mmap_event
*mmap_event
)
3710 struct perf_event
*event
;
3712 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3713 if (perf_event_mmap_match(event
, mmap_event
))
3714 perf_event_mmap_output(event
, mmap_event
);
3718 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
3720 struct perf_cpu_context
*cpuctx
;
3721 struct perf_event_context
*ctx
;
3722 struct vm_area_struct
*vma
= mmap_event
->vma
;
3723 struct file
*file
= vma
->vm_file
;
3729 memset(tmp
, 0, sizeof(tmp
));
3733 * d_path works from the end of the buffer backwards, so we
3734 * need to add enough zero bytes after the string to handle
3735 * the 64bit alignment we do later.
3737 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
3739 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
3742 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
3744 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
3748 if (arch_vma_name(mmap_event
->vma
)) {
3749 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
3755 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
3759 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
3764 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
3766 mmap_event
->file_name
= name
;
3767 mmap_event
->file_size
= size
;
3769 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
3772 cpuctx
= &get_cpu_var(perf_cpu_context
);
3773 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
);
3774 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3776 perf_event_mmap_ctx(ctx
, mmap_event
);
3777 put_cpu_var(perf_cpu_context
);
3783 void __perf_event_mmap(struct vm_area_struct
*vma
)
3785 struct perf_mmap_event mmap_event
;
3787 if (!atomic_read(&nr_mmap_events
))
3790 mmap_event
= (struct perf_mmap_event
){
3796 .type
= PERF_RECORD_MMAP
,
3797 .misc
= PERF_RECORD_MISC_USER
,
3802 .start
= vma
->vm_start
,
3803 .len
= vma
->vm_end
- vma
->vm_start
,
3804 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
3808 perf_event_mmap_event(&mmap_event
);
3812 * IRQ throttle logging
3815 static void perf_log_throttle(struct perf_event
*event
, int enable
)
3817 struct perf_output_handle handle
;
3821 struct perf_event_header header
;
3825 } throttle_event
= {
3827 .type
= PERF_RECORD_THROTTLE
,
3829 .size
= sizeof(throttle_event
),
3831 .time
= perf_clock(),
3832 .id
= primary_event_id(event
),
3833 .stream_id
= event
->id
,
3837 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
3839 ret
= perf_output_begin(&handle
, event
, sizeof(throttle_event
), 1, 0);
3843 perf_output_put(&handle
, throttle_event
);
3844 perf_output_end(&handle
);
3848 * Generic event overflow handling, sampling.
3851 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
3852 int throttle
, struct perf_sample_data
*data
,
3853 struct pt_regs
*regs
)
3855 int events
= atomic_read(&event
->event_limit
);
3856 struct hw_perf_event
*hwc
= &event
->hw
;
3859 throttle
= (throttle
&& event
->pmu
->unthrottle
!= NULL
);
3864 if (hwc
->interrupts
!= MAX_INTERRUPTS
) {
3866 if (HZ
* hwc
->interrupts
>
3867 (u64
)sysctl_perf_event_sample_rate
) {
3868 hwc
->interrupts
= MAX_INTERRUPTS
;
3869 perf_log_throttle(event
, 0);
3874 * Keep re-disabling events even though on the previous
3875 * pass we disabled it - just in case we raced with a
3876 * sched-in and the event got enabled again:
3882 if (event
->attr
.freq
) {
3883 u64 now
= perf_clock();
3884 s64 delta
= now
- hwc
->freq_time_stamp
;
3886 hwc
->freq_time_stamp
= now
;
3888 if (delta
> 0 && delta
< 2*TICK_NSEC
)
3889 perf_adjust_period(event
, delta
, hwc
->last_period
);
3893 * XXX event_limit might not quite work as expected on inherited
3897 event
->pending_kill
= POLL_IN
;
3898 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
3900 event
->pending_kill
= POLL_HUP
;
3902 event
->pending_disable
= 1;
3903 perf_pending_queue(&event
->pending
,
3904 perf_pending_event
);
3906 perf_event_disable(event
);
3909 if (event
->overflow_handler
)
3910 event
->overflow_handler(event
, nmi
, data
, regs
);
3912 perf_event_output(event
, nmi
, data
, regs
);
3917 int perf_event_overflow(struct perf_event
*event
, int nmi
,
3918 struct perf_sample_data
*data
,
3919 struct pt_regs
*regs
)
3921 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
3925 * Generic software event infrastructure
3929 * We directly increment event->count and keep a second value in
3930 * event->hw.period_left to count intervals. This period event
3931 * is kept in the range [-sample_period, 0] so that we can use the
3935 static u64
perf_swevent_set_period(struct perf_event
*event
)
3937 struct hw_perf_event
*hwc
= &event
->hw
;
3938 u64 period
= hwc
->last_period
;
3942 hwc
->last_period
= hwc
->sample_period
;
3945 old
= val
= atomic64_read(&hwc
->period_left
);
3949 nr
= div64_u64(period
+ val
, period
);
3950 offset
= nr
* period
;
3952 if (atomic64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
3958 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
3959 int nmi
, struct perf_sample_data
*data
,
3960 struct pt_regs
*regs
)
3962 struct hw_perf_event
*hwc
= &event
->hw
;
3965 data
->period
= event
->hw
.last_period
;
3967 overflow
= perf_swevent_set_period(event
);
3969 if (hwc
->interrupts
== MAX_INTERRUPTS
)
3972 for (; overflow
; overflow
--) {
3973 if (__perf_event_overflow(event
, nmi
, throttle
,
3976 * We inhibit the overflow from happening when
3977 * hwc->interrupts == MAX_INTERRUPTS.
3985 static void perf_swevent_unthrottle(struct perf_event
*event
)
3988 * Nothing to do, we already reset hwc->interrupts.
3992 static void perf_swevent_add(struct perf_event
*event
, u64 nr
,
3993 int nmi
, struct perf_sample_data
*data
,
3994 struct pt_regs
*regs
)
3996 struct hw_perf_event
*hwc
= &event
->hw
;
3998 atomic64_add(nr
, &event
->count
);
4003 if (!hwc
->sample_period
)
4006 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
4007 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
4009 if (atomic64_add_negative(nr
, &hwc
->period_left
))
4012 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
4015 static int perf_tp_event_match(struct perf_event
*event
,
4016 struct perf_sample_data
*data
);
4018 static int perf_exclude_event(struct perf_event
*event
,
4019 struct pt_regs
*regs
)
4022 if (event
->attr
.exclude_user
&& user_mode(regs
))
4025 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4032 static int perf_swevent_match(struct perf_event
*event
,
4033 enum perf_type_id type
,
4035 struct perf_sample_data
*data
,
4036 struct pt_regs
*regs
)
4038 if (event
->attr
.type
!= type
)
4041 if (event
->attr
.config
!= event_id
)
4044 if (perf_exclude_event(event
, regs
))
4047 if (event
->attr
.type
== PERF_TYPE_TRACEPOINT
&&
4048 !perf_tp_event_match(event
, data
))
4054 static inline u64
swevent_hash(u64 type
, u32 event_id
)
4056 u64 val
= event_id
| (type
<< 32);
4058 return hash_64(val
, SWEVENT_HLIST_BITS
);
4061 static struct hlist_head
*
4062 find_swevent_head(struct perf_cpu_context
*ctx
, u64 type
, u32 event_id
)
4065 struct swevent_hlist
*hlist
;
4067 hash
= swevent_hash(type
, event_id
);
4069 hlist
= rcu_dereference(ctx
->swevent_hlist
);
4073 return &hlist
->heads
[hash
];
4076 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4078 struct perf_sample_data
*data
,
4079 struct pt_regs
*regs
)
4081 struct perf_cpu_context
*cpuctx
;
4082 struct perf_event
*event
;
4083 struct hlist_node
*node
;
4084 struct hlist_head
*head
;
4086 cpuctx
= &__get_cpu_var(perf_cpu_context
);
4090 head
= find_swevent_head(cpuctx
, type
, event_id
);
4095 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4096 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4097 perf_swevent_add(event
, nr
, nmi
, data
, regs
);
4103 int perf_swevent_get_recursion_context(void)
4105 struct perf_cpu_context
*cpuctx
= &get_cpu_var(perf_cpu_context
);
4112 else if (in_softirq())
4117 if (cpuctx
->recursion
[rctx
]) {
4118 put_cpu_var(perf_cpu_context
);
4122 cpuctx
->recursion
[rctx
]++;
4127 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4129 void perf_swevent_put_recursion_context(int rctx
)
4131 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
4133 cpuctx
->recursion
[rctx
]--;
4134 put_cpu_var(perf_cpu_context
);
4136 EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context
);
4139 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
4140 struct pt_regs
*regs
, u64 addr
)
4142 struct perf_sample_data data
;
4145 rctx
= perf_swevent_get_recursion_context();
4149 perf_sample_data_init(&data
, addr
);
4151 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
4153 perf_swevent_put_recursion_context(rctx
);
4156 static void perf_swevent_read(struct perf_event
*event
)
4160 static int perf_swevent_enable(struct perf_event
*event
)
4162 struct hw_perf_event
*hwc
= &event
->hw
;
4163 struct perf_cpu_context
*cpuctx
;
4164 struct hlist_head
*head
;
4166 cpuctx
= &__get_cpu_var(perf_cpu_context
);
4168 if (hwc
->sample_period
) {
4169 hwc
->last_period
= hwc
->sample_period
;
4170 perf_swevent_set_period(event
);
4173 head
= find_swevent_head(cpuctx
, event
->attr
.type
, event
->attr
.config
);
4174 if (WARN_ON_ONCE(!head
))
4177 hlist_add_head_rcu(&event
->hlist_entry
, head
);
4182 static void perf_swevent_disable(struct perf_event
*event
)
4184 hlist_del_rcu(&event
->hlist_entry
);
4187 static const struct pmu perf_ops_generic
= {
4188 .enable
= perf_swevent_enable
,
4189 .disable
= perf_swevent_disable
,
4190 .read
= perf_swevent_read
,
4191 .unthrottle
= perf_swevent_unthrottle
,
4195 * hrtimer based swevent callback
4198 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
4200 enum hrtimer_restart ret
= HRTIMER_RESTART
;
4201 struct perf_sample_data data
;
4202 struct pt_regs
*regs
;
4203 struct perf_event
*event
;
4206 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
4207 event
->pmu
->read(event
);
4209 perf_sample_data_init(&data
, 0);
4210 data
.period
= event
->hw
.last_period
;
4211 regs
= get_irq_regs();
4213 if (regs
&& !perf_exclude_event(event
, regs
)) {
4214 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
4215 if (perf_event_overflow(event
, 0, &data
, regs
))
4216 ret
= HRTIMER_NORESTART
;
4219 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
4220 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
4225 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
4227 struct hw_perf_event
*hwc
= &event
->hw
;
4229 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
4230 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
4231 if (hwc
->sample_period
) {
4234 if (hwc
->remaining
) {
4235 if (hwc
->remaining
< 0)
4238 period
= hwc
->remaining
;
4241 period
= max_t(u64
, 10000, hwc
->sample_period
);
4243 __hrtimer_start_range_ns(&hwc
->hrtimer
,
4244 ns_to_ktime(period
), 0,
4245 HRTIMER_MODE_REL
, 0);
4249 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
4251 struct hw_perf_event
*hwc
= &event
->hw
;
4253 if (hwc
->sample_period
) {
4254 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
4255 hwc
->remaining
= ktime_to_ns(remaining
);
4257 hrtimer_cancel(&hwc
->hrtimer
);
4262 * Software event: cpu wall time clock
4265 static void cpu_clock_perf_event_update(struct perf_event
*event
)
4267 int cpu
= raw_smp_processor_id();
4271 now
= cpu_clock(cpu
);
4272 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4273 atomic64_add(now
- prev
, &event
->count
);
4276 static int cpu_clock_perf_event_enable(struct perf_event
*event
)
4278 struct hw_perf_event
*hwc
= &event
->hw
;
4279 int cpu
= raw_smp_processor_id();
4281 atomic64_set(&hwc
->prev_count
, cpu_clock(cpu
));
4282 perf_swevent_start_hrtimer(event
);
4287 static void cpu_clock_perf_event_disable(struct perf_event
*event
)
4289 perf_swevent_cancel_hrtimer(event
);
4290 cpu_clock_perf_event_update(event
);
4293 static void cpu_clock_perf_event_read(struct perf_event
*event
)
4295 cpu_clock_perf_event_update(event
);
4298 static const struct pmu perf_ops_cpu_clock
= {
4299 .enable
= cpu_clock_perf_event_enable
,
4300 .disable
= cpu_clock_perf_event_disable
,
4301 .read
= cpu_clock_perf_event_read
,
4305 * Software event: task time clock
4308 static void task_clock_perf_event_update(struct perf_event
*event
, u64 now
)
4313 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4315 atomic64_add(delta
, &event
->count
);
4318 static int task_clock_perf_event_enable(struct perf_event
*event
)
4320 struct hw_perf_event
*hwc
= &event
->hw
;
4323 now
= event
->ctx
->time
;
4325 atomic64_set(&hwc
->prev_count
, now
);
4327 perf_swevent_start_hrtimer(event
);
4332 static void task_clock_perf_event_disable(struct perf_event
*event
)
4334 perf_swevent_cancel_hrtimer(event
);
4335 task_clock_perf_event_update(event
, event
->ctx
->time
);
4339 static void task_clock_perf_event_read(struct perf_event
*event
)
4344 update_context_time(event
->ctx
);
4345 time
= event
->ctx
->time
;
4347 u64 now
= perf_clock();
4348 u64 delta
= now
- event
->ctx
->timestamp
;
4349 time
= event
->ctx
->time
+ delta
;
4352 task_clock_perf_event_update(event
, time
);
4355 static const struct pmu perf_ops_task_clock
= {
4356 .enable
= task_clock_perf_event_enable
,
4357 .disable
= task_clock_perf_event_disable
,
4358 .read
= task_clock_perf_event_read
,
4361 static void swevent_hlist_release_rcu(struct rcu_head
*rcu_head
)
4363 struct swevent_hlist
*hlist
;
4365 hlist
= container_of(rcu_head
, struct swevent_hlist
, rcu_head
);
4369 static void swevent_hlist_release(struct perf_cpu_context
*cpuctx
)
4371 struct swevent_hlist
*hlist
;
4373 if (!cpuctx
->swevent_hlist
)
4376 hlist
= cpuctx
->swevent_hlist
;
4377 rcu_assign_pointer(cpuctx
->swevent_hlist
, NULL
);
4378 call_rcu(&hlist
->rcu_head
, swevent_hlist_release_rcu
);
4381 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
4383 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
4385 mutex_lock(&cpuctx
->hlist_mutex
);
4387 if (!--cpuctx
->hlist_refcount
)
4388 swevent_hlist_release(cpuctx
);
4390 mutex_unlock(&cpuctx
->hlist_mutex
);
4393 static void swevent_hlist_put(struct perf_event
*event
)
4397 if (event
->cpu
!= -1) {
4398 swevent_hlist_put_cpu(event
, event
->cpu
);
4402 for_each_possible_cpu(cpu
)
4403 swevent_hlist_put_cpu(event
, cpu
);
4406 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
4408 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
4411 mutex_lock(&cpuctx
->hlist_mutex
);
4413 if (!cpuctx
->swevent_hlist
&& cpu_online(cpu
)) {
4414 struct swevent_hlist
*hlist
;
4416 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
4421 rcu_assign_pointer(cpuctx
->swevent_hlist
, hlist
);
4423 cpuctx
->hlist_refcount
++;
4425 mutex_unlock(&cpuctx
->hlist_mutex
);
4430 static int swevent_hlist_get(struct perf_event
*event
)
4433 int cpu
, failed_cpu
;
4435 if (event
->cpu
!= -1)
4436 return swevent_hlist_get_cpu(event
, event
->cpu
);
4439 for_each_possible_cpu(cpu
) {
4440 err
= swevent_hlist_get_cpu(event
, cpu
);
4450 for_each_possible_cpu(cpu
) {
4451 if (cpu
== failed_cpu
)
4453 swevent_hlist_put_cpu(event
, cpu
);
4460 #ifdef CONFIG_EVENT_TRACING
4462 void perf_tp_event(int event_id
, u64 addr
, u64 count
, void *record
,
4463 int entry_size
, struct pt_regs
*regs
)
4465 struct perf_sample_data data
;
4466 struct perf_raw_record raw
= {
4471 perf_sample_data_init(&data
, addr
);
4474 /* Trace events already protected against recursion */
4475 do_perf_sw_event(PERF_TYPE_TRACEPOINT
, event_id
, count
, 1,
4478 EXPORT_SYMBOL_GPL(perf_tp_event
);
4480 static int perf_tp_event_match(struct perf_event
*event
,
4481 struct perf_sample_data
*data
)
4483 void *record
= data
->raw
->data
;
4485 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
4490 static void tp_perf_event_destroy(struct perf_event
*event
)
4492 perf_trace_disable(event
->attr
.config
);
4493 swevent_hlist_put(event
);
4496 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4501 * Raw tracepoint data is a severe data leak, only allow root to
4504 if ((event
->attr
.sample_type
& PERF_SAMPLE_RAW
) &&
4505 perf_paranoid_tracepoint_raw() &&
4506 !capable(CAP_SYS_ADMIN
))
4507 return ERR_PTR(-EPERM
);
4509 if (perf_trace_enable(event
->attr
.config
))
4512 event
->destroy
= tp_perf_event_destroy
;
4513 err
= swevent_hlist_get(event
);
4515 perf_trace_disable(event
->attr
.config
);
4516 return ERR_PTR(err
);
4519 return &perf_ops_generic
;
4522 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4527 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4530 filter_str
= strndup_user(arg
, PAGE_SIZE
);
4531 if (IS_ERR(filter_str
))
4532 return PTR_ERR(filter_str
);
4534 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
4540 static void perf_event_free_filter(struct perf_event
*event
)
4542 ftrace_profile_free_filter(event
);
4547 static int perf_tp_event_match(struct perf_event
*event
,
4548 struct perf_sample_data
*data
)
4553 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4558 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4563 static void perf_event_free_filter(struct perf_event
*event
)
4567 #endif /* CONFIG_EVENT_TRACING */
4569 #ifdef CONFIG_HAVE_HW_BREAKPOINT
4570 static void bp_perf_event_destroy(struct perf_event
*event
)
4572 release_bp_slot(event
);
4575 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4579 err
= register_perf_hw_breakpoint(bp
);
4581 return ERR_PTR(err
);
4583 bp
->destroy
= bp_perf_event_destroy
;
4585 return &perf_ops_bp
;
4588 void perf_bp_event(struct perf_event
*bp
, void *data
)
4590 struct perf_sample_data sample
;
4591 struct pt_regs
*regs
= data
;
4593 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
4595 if (!perf_exclude_event(bp
, regs
))
4596 perf_swevent_add(bp
, 1, 1, &sample
, regs
);
4599 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4604 void perf_bp_event(struct perf_event
*bp
, void *regs
)
4609 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4611 static void sw_perf_event_destroy(struct perf_event
*event
)
4613 u64 event_id
= event
->attr
.config
;
4615 WARN_ON(event
->parent
);
4617 atomic_dec(&perf_swevent_enabled
[event_id
]);
4618 swevent_hlist_put(event
);
4621 static const struct pmu
*sw_perf_event_init(struct perf_event
*event
)
4623 const struct pmu
*pmu
= NULL
;
4624 u64 event_id
= event
->attr
.config
;
4627 * Software events (currently) can't in general distinguish
4628 * between user, kernel and hypervisor events.
4629 * However, context switches and cpu migrations are considered
4630 * to be kernel events, and page faults are never hypervisor
4634 case PERF_COUNT_SW_CPU_CLOCK
:
4635 pmu
= &perf_ops_cpu_clock
;
4638 case PERF_COUNT_SW_TASK_CLOCK
:
4640 * If the user instantiates this as a per-cpu event,
4641 * use the cpu_clock event instead.
4643 if (event
->ctx
->task
)
4644 pmu
= &perf_ops_task_clock
;
4646 pmu
= &perf_ops_cpu_clock
;
4649 case PERF_COUNT_SW_PAGE_FAULTS
:
4650 case PERF_COUNT_SW_PAGE_FAULTS_MIN
:
4651 case PERF_COUNT_SW_PAGE_FAULTS_MAJ
:
4652 case PERF_COUNT_SW_CONTEXT_SWITCHES
:
4653 case PERF_COUNT_SW_CPU_MIGRATIONS
:
4654 case PERF_COUNT_SW_ALIGNMENT_FAULTS
:
4655 case PERF_COUNT_SW_EMULATION_FAULTS
:
4656 if (!event
->parent
) {
4659 err
= swevent_hlist_get(event
);
4661 return ERR_PTR(err
);
4663 atomic_inc(&perf_swevent_enabled
[event_id
]);
4664 event
->destroy
= sw_perf_event_destroy
;
4666 pmu
= &perf_ops_generic
;
4674 * Allocate and initialize a event structure
4676 static struct perf_event
*
4677 perf_event_alloc(struct perf_event_attr
*attr
,
4679 struct perf_event_context
*ctx
,
4680 struct perf_event
*group_leader
,
4681 struct perf_event
*parent_event
,
4682 perf_overflow_handler_t overflow_handler
,
4685 const struct pmu
*pmu
;
4686 struct perf_event
*event
;
4687 struct hw_perf_event
*hwc
;
4690 event
= kzalloc(sizeof(*event
), gfpflags
);
4692 return ERR_PTR(-ENOMEM
);
4695 * Single events are their own group leaders, with an
4696 * empty sibling list:
4699 group_leader
= event
;
4701 mutex_init(&event
->child_mutex
);
4702 INIT_LIST_HEAD(&event
->child_list
);
4704 INIT_LIST_HEAD(&event
->group_entry
);
4705 INIT_LIST_HEAD(&event
->event_entry
);
4706 INIT_LIST_HEAD(&event
->sibling_list
);
4707 init_waitqueue_head(&event
->waitq
);
4709 mutex_init(&event
->mmap_mutex
);
4712 event
->attr
= *attr
;
4713 event
->group_leader
= group_leader
;
4718 event
->parent
= parent_event
;
4720 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
4721 event
->id
= atomic64_inc_return(&perf_event_id
);
4723 event
->state
= PERF_EVENT_STATE_INACTIVE
;
4725 if (!overflow_handler
&& parent_event
)
4726 overflow_handler
= parent_event
->overflow_handler
;
4728 event
->overflow_handler
= overflow_handler
;
4731 event
->state
= PERF_EVENT_STATE_OFF
;
4736 hwc
->sample_period
= attr
->sample_period
;
4737 if (attr
->freq
&& attr
->sample_freq
)
4738 hwc
->sample_period
= 1;
4739 hwc
->last_period
= hwc
->sample_period
;
4741 atomic64_set(&hwc
->period_left
, hwc
->sample_period
);
4744 * we currently do not support PERF_FORMAT_GROUP on inherited events
4746 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
4749 switch (attr
->type
) {
4751 case PERF_TYPE_HARDWARE
:
4752 case PERF_TYPE_HW_CACHE
:
4753 pmu
= hw_perf_event_init(event
);
4756 case PERF_TYPE_SOFTWARE
:
4757 pmu
= sw_perf_event_init(event
);
4760 case PERF_TYPE_TRACEPOINT
:
4761 pmu
= tp_perf_event_init(event
);
4764 case PERF_TYPE_BREAKPOINT
:
4765 pmu
= bp_perf_event_init(event
);
4776 else if (IS_ERR(pmu
))
4781 put_pid_ns(event
->ns
);
4783 return ERR_PTR(err
);
4788 if (!event
->parent
) {
4789 atomic_inc(&nr_events
);
4790 if (event
->attr
.mmap
)
4791 atomic_inc(&nr_mmap_events
);
4792 if (event
->attr
.comm
)
4793 atomic_inc(&nr_comm_events
);
4794 if (event
->attr
.task
)
4795 atomic_inc(&nr_task_events
);
4801 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
4802 struct perf_event_attr
*attr
)
4807 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
4811 * zero the full structure, so that a short copy will be nice.
4813 memset(attr
, 0, sizeof(*attr
));
4815 ret
= get_user(size
, &uattr
->size
);
4819 if (size
> PAGE_SIZE
) /* silly large */
4822 if (!size
) /* abi compat */
4823 size
= PERF_ATTR_SIZE_VER0
;
4825 if (size
< PERF_ATTR_SIZE_VER0
)
4829 * If we're handed a bigger struct than we know of,
4830 * ensure all the unknown bits are 0 - i.e. new
4831 * user-space does not rely on any kernel feature
4832 * extensions we dont know about yet.
4834 if (size
> sizeof(*attr
)) {
4835 unsigned char __user
*addr
;
4836 unsigned char __user
*end
;
4839 addr
= (void __user
*)uattr
+ sizeof(*attr
);
4840 end
= (void __user
*)uattr
+ size
;
4842 for (; addr
< end
; addr
++) {
4843 ret
= get_user(val
, addr
);
4849 size
= sizeof(*attr
);
4852 ret
= copy_from_user(attr
, uattr
, size
);
4857 * If the type exists, the corresponding creation will verify
4860 if (attr
->type
>= PERF_TYPE_MAX
)
4863 if (attr
->__reserved_1
)
4866 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
4869 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
4876 put_user(sizeof(*attr
), &uattr
->size
);
4881 static int perf_event_set_output(struct perf_event
*event
, int output_fd
)
4883 struct perf_event
*output_event
= NULL
;
4884 struct file
*output_file
= NULL
;
4885 struct perf_event
*old_output
;
4886 int fput_needed
= 0;
4892 output_file
= fget_light(output_fd
, &fput_needed
);
4896 if (output_file
->f_op
!= &perf_fops
)
4899 output_event
= output_file
->private_data
;
4901 /* Don't chain output fds */
4902 if (output_event
->output
)
4905 /* Don't set an output fd when we already have an output channel */
4909 atomic_long_inc(&output_file
->f_count
);
4912 mutex_lock(&event
->mmap_mutex
);
4913 old_output
= event
->output
;
4914 rcu_assign_pointer(event
->output
, output_event
);
4915 mutex_unlock(&event
->mmap_mutex
);
4919 * we need to make sure no existing perf_output_*()
4920 * is still referencing this event.
4923 fput(old_output
->filp
);
4928 fput_light(output_file
, fput_needed
);
4933 * sys_perf_event_open - open a performance event, associate it to a task/cpu
4935 * @attr_uptr: event_id type attributes for monitoring/sampling
4938 * @group_fd: group leader event fd
4940 SYSCALL_DEFINE5(perf_event_open
,
4941 struct perf_event_attr __user
*, attr_uptr
,
4942 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
4944 struct perf_event
*event
, *group_leader
;
4945 struct perf_event_attr attr
;
4946 struct perf_event_context
*ctx
;
4947 struct file
*event_file
= NULL
;
4948 struct file
*group_file
= NULL
;
4949 int fput_needed
= 0;
4950 int fput_needed2
= 0;
4953 /* for future expandability... */
4954 if (flags
& ~(PERF_FLAG_FD_NO_GROUP
| PERF_FLAG_FD_OUTPUT
))
4957 err
= perf_copy_attr(attr_uptr
, &attr
);
4961 if (!attr
.exclude_kernel
) {
4962 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
4967 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
4972 * Get the target context (task or percpu):
4974 ctx
= find_get_context(pid
, cpu
);
4976 return PTR_ERR(ctx
);
4979 * Look up the group leader (we will attach this event to it):
4981 group_leader
= NULL
;
4982 if (group_fd
!= -1 && !(flags
& PERF_FLAG_FD_NO_GROUP
)) {
4984 group_file
= fget_light(group_fd
, &fput_needed
);
4986 goto err_put_context
;
4987 if (group_file
->f_op
!= &perf_fops
)
4988 goto err_put_context
;
4990 group_leader
= group_file
->private_data
;
4992 * Do not allow a recursive hierarchy (this new sibling
4993 * becoming part of another group-sibling):
4995 if (group_leader
->group_leader
!= group_leader
)
4996 goto err_put_context
;
4998 * Do not allow to attach to a group in a different
4999 * task or CPU context:
5001 if (group_leader
->ctx
!= ctx
)
5002 goto err_put_context
;
5004 * Only a group leader can be exclusive or pinned
5006 if (attr
.exclusive
|| attr
.pinned
)
5007 goto err_put_context
;
5010 event
= perf_event_alloc(&attr
, cpu
, ctx
, group_leader
,
5011 NULL
, NULL
, GFP_KERNEL
);
5012 err
= PTR_ERR(event
);
5014 goto err_put_context
;
5016 err
= anon_inode_getfd("[perf_event]", &perf_fops
, event
, O_RDWR
);
5018 goto err_free_put_context
;
5020 event_file
= fget_light(err
, &fput_needed2
);
5022 goto err_free_put_context
;
5024 if (flags
& PERF_FLAG_FD_OUTPUT
) {
5025 err
= perf_event_set_output(event
, group_fd
);
5027 goto err_fput_free_put_context
;
5030 event
->filp
= event_file
;
5031 WARN_ON_ONCE(ctx
->parent_ctx
);
5032 mutex_lock(&ctx
->mutex
);
5033 perf_install_in_context(ctx
, event
, cpu
);
5035 mutex_unlock(&ctx
->mutex
);
5037 event
->owner
= current
;
5038 get_task_struct(current
);
5039 mutex_lock(¤t
->perf_event_mutex
);
5040 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
5041 mutex_unlock(¤t
->perf_event_mutex
);
5043 err_fput_free_put_context
:
5044 fput_light(event_file
, fput_needed2
);
5046 err_free_put_context
:
5054 fput_light(group_file
, fput_needed
);
5060 * perf_event_create_kernel_counter
5062 * @attr: attributes of the counter to create
5063 * @cpu: cpu in which the counter is bound
5064 * @pid: task to profile
5067 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
5069 perf_overflow_handler_t overflow_handler
)
5071 struct perf_event
*event
;
5072 struct perf_event_context
*ctx
;
5076 * Get the target context (task or percpu):
5079 ctx
= find_get_context(pid
, cpu
);
5085 event
= perf_event_alloc(attr
, cpu
, ctx
, NULL
,
5086 NULL
, overflow_handler
, GFP_KERNEL
);
5087 if (IS_ERR(event
)) {
5088 err
= PTR_ERR(event
);
5089 goto err_put_context
;
5093 WARN_ON_ONCE(ctx
->parent_ctx
);
5094 mutex_lock(&ctx
->mutex
);
5095 perf_install_in_context(ctx
, event
, cpu
);
5097 mutex_unlock(&ctx
->mutex
);
5099 event
->owner
= current
;
5100 get_task_struct(current
);
5101 mutex_lock(¤t
->perf_event_mutex
);
5102 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
5103 mutex_unlock(¤t
->perf_event_mutex
);
5110 return ERR_PTR(err
);
5112 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
5115 * inherit a event from parent task to child task:
5117 static struct perf_event
*
5118 inherit_event(struct perf_event
*parent_event
,
5119 struct task_struct
*parent
,
5120 struct perf_event_context
*parent_ctx
,
5121 struct task_struct
*child
,
5122 struct perf_event
*group_leader
,
5123 struct perf_event_context
*child_ctx
)
5125 struct perf_event
*child_event
;
5128 * Instead of creating recursive hierarchies of events,
5129 * we link inherited events back to the original parent,
5130 * which has a filp for sure, which we use as the reference
5133 if (parent_event
->parent
)
5134 parent_event
= parent_event
->parent
;
5136 child_event
= perf_event_alloc(&parent_event
->attr
,
5137 parent_event
->cpu
, child_ctx
,
5138 group_leader
, parent_event
,
5140 if (IS_ERR(child_event
))
5145 * Make the child state follow the state of the parent event,
5146 * not its attr.disabled bit. We hold the parent's mutex,
5147 * so we won't race with perf_event_{en, dis}able_family.
5149 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
5150 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
5152 child_event
->state
= PERF_EVENT_STATE_OFF
;
5154 if (parent_event
->attr
.freq
) {
5155 u64 sample_period
= parent_event
->hw
.sample_period
;
5156 struct hw_perf_event
*hwc
= &child_event
->hw
;
5158 hwc
->sample_period
= sample_period
;
5159 hwc
->last_period
= sample_period
;
5161 atomic64_set(&hwc
->period_left
, sample_period
);
5164 child_event
->overflow_handler
= parent_event
->overflow_handler
;
5167 * Link it up in the child's context:
5169 add_event_to_ctx(child_event
, child_ctx
);
5172 * Get a reference to the parent filp - we will fput it
5173 * when the child event exits. This is safe to do because
5174 * we are in the parent and we know that the filp still
5175 * exists and has a nonzero count:
5177 atomic_long_inc(&parent_event
->filp
->f_count
);
5180 * Link this into the parent event's child list
5182 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5183 mutex_lock(&parent_event
->child_mutex
);
5184 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
5185 mutex_unlock(&parent_event
->child_mutex
);
5190 static int inherit_group(struct perf_event
*parent_event
,
5191 struct task_struct
*parent
,
5192 struct perf_event_context
*parent_ctx
,
5193 struct task_struct
*child
,
5194 struct perf_event_context
*child_ctx
)
5196 struct perf_event
*leader
;
5197 struct perf_event
*sub
;
5198 struct perf_event
*child_ctr
;
5200 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
5201 child
, NULL
, child_ctx
);
5203 return PTR_ERR(leader
);
5204 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
5205 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
5206 child
, leader
, child_ctx
);
5207 if (IS_ERR(child_ctr
))
5208 return PTR_ERR(child_ctr
);
5213 static void sync_child_event(struct perf_event
*child_event
,
5214 struct task_struct
*child
)
5216 struct perf_event
*parent_event
= child_event
->parent
;
5219 if (child_event
->attr
.inherit_stat
)
5220 perf_event_read_event(child_event
, child
);
5222 child_val
= atomic64_read(&child_event
->count
);
5225 * Add back the child's count to the parent's count:
5227 atomic64_add(child_val
, &parent_event
->count
);
5228 atomic64_add(child_event
->total_time_enabled
,
5229 &parent_event
->child_total_time_enabled
);
5230 atomic64_add(child_event
->total_time_running
,
5231 &parent_event
->child_total_time_running
);
5234 * Remove this event from the parent's list
5236 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5237 mutex_lock(&parent_event
->child_mutex
);
5238 list_del_init(&child_event
->child_list
);
5239 mutex_unlock(&parent_event
->child_mutex
);
5242 * Release the parent event, if this was the last
5245 fput(parent_event
->filp
);
5249 __perf_event_exit_task(struct perf_event
*child_event
,
5250 struct perf_event_context
*child_ctx
,
5251 struct task_struct
*child
)
5253 struct perf_event
*parent_event
;
5255 perf_event_remove_from_context(child_event
);
5257 parent_event
= child_event
->parent
;
5259 * It can happen that parent exits first, and has events
5260 * that are still around due to the child reference. These
5261 * events need to be zapped - but otherwise linger.
5264 sync_child_event(child_event
, child
);
5265 free_event(child_event
);
5270 * When a child task exits, feed back event values to parent events.
5272 void perf_event_exit_task(struct task_struct
*child
)
5274 struct perf_event
*child_event
, *tmp
;
5275 struct perf_event_context
*child_ctx
;
5276 unsigned long flags
;
5278 if (likely(!child
->perf_event_ctxp
)) {
5279 perf_event_task(child
, NULL
, 0);
5283 local_irq_save(flags
);
5285 * We can't reschedule here because interrupts are disabled,
5286 * and either child is current or it is a task that can't be
5287 * scheduled, so we are now safe from rescheduling changing
5290 child_ctx
= child
->perf_event_ctxp
;
5291 __perf_event_task_sched_out(child_ctx
);
5294 * Take the context lock here so that if find_get_context is
5295 * reading child->perf_event_ctxp, we wait until it has
5296 * incremented the context's refcount before we do put_ctx below.
5298 raw_spin_lock(&child_ctx
->lock
);
5299 child
->perf_event_ctxp
= NULL
;
5301 * If this context is a clone; unclone it so it can't get
5302 * swapped to another process while we're removing all
5303 * the events from it.
5305 unclone_ctx(child_ctx
);
5306 update_context_time(child_ctx
);
5307 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
5310 * Report the task dead after unscheduling the events so that we
5311 * won't get any samples after PERF_RECORD_EXIT. We can however still
5312 * get a few PERF_RECORD_READ events.
5314 perf_event_task(child
, child_ctx
, 0);
5317 * We can recurse on the same lock type through:
5319 * __perf_event_exit_task()
5320 * sync_child_event()
5321 * fput(parent_event->filp)
5323 * mutex_lock(&ctx->mutex)
5325 * But since its the parent context it won't be the same instance.
5327 mutex_lock(&child_ctx
->mutex
);
5330 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
5332 __perf_event_exit_task(child_event
, child_ctx
, child
);
5334 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
5336 __perf_event_exit_task(child_event
, child_ctx
, child
);
5339 * If the last event was a group event, it will have appended all
5340 * its siblings to the list, but we obtained 'tmp' before that which
5341 * will still point to the list head terminating the iteration.
5343 if (!list_empty(&child_ctx
->pinned_groups
) ||
5344 !list_empty(&child_ctx
->flexible_groups
))
5347 mutex_unlock(&child_ctx
->mutex
);
5352 static void perf_free_event(struct perf_event
*event
,
5353 struct perf_event_context
*ctx
)
5355 struct perf_event
*parent
= event
->parent
;
5357 if (WARN_ON_ONCE(!parent
))
5360 mutex_lock(&parent
->child_mutex
);
5361 list_del_init(&event
->child_list
);
5362 mutex_unlock(&parent
->child_mutex
);
5366 list_del_event(event
, ctx
);
5371 * free an unexposed, unused context as created by inheritance by
5372 * init_task below, used by fork() in case of fail.
5374 void perf_event_free_task(struct task_struct
*task
)
5376 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
5377 struct perf_event
*event
, *tmp
;
5382 mutex_lock(&ctx
->mutex
);
5384 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5385 perf_free_event(event
, ctx
);
5387 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
5389 perf_free_event(event
, ctx
);
5391 if (!list_empty(&ctx
->pinned_groups
) ||
5392 !list_empty(&ctx
->flexible_groups
))
5395 mutex_unlock(&ctx
->mutex
);
5401 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
5402 struct perf_event_context
*parent_ctx
,
5403 struct task_struct
*child
,
5407 struct perf_event_context
*child_ctx
= child
->perf_event_ctxp
;
5409 if (!event
->attr
.inherit
) {
5416 * This is executed from the parent task context, so
5417 * inherit events that have been marked for cloning.
5418 * First allocate and initialize a context for the
5422 child_ctx
= kzalloc(sizeof(struct perf_event_context
),
5427 __perf_event_init_context(child_ctx
, child
);
5428 child
->perf_event_ctxp
= child_ctx
;
5429 get_task_struct(child
);
5432 ret
= inherit_group(event
, parent
, parent_ctx
,
5443 * Initialize the perf_event context in task_struct
5445 int perf_event_init_task(struct task_struct
*child
)
5447 struct perf_event_context
*child_ctx
, *parent_ctx
;
5448 struct perf_event_context
*cloned_ctx
;
5449 struct perf_event
*event
;
5450 struct task_struct
*parent
= current
;
5451 int inherited_all
= 1;
5454 child
->perf_event_ctxp
= NULL
;
5456 mutex_init(&child
->perf_event_mutex
);
5457 INIT_LIST_HEAD(&child
->perf_event_list
);
5459 if (likely(!parent
->perf_event_ctxp
))
5463 * If the parent's context is a clone, pin it so it won't get
5466 parent_ctx
= perf_pin_task_context(parent
);
5469 * No need to check if parent_ctx != NULL here; since we saw
5470 * it non-NULL earlier, the only reason for it to become NULL
5471 * is if we exit, and since we're currently in the middle of
5472 * a fork we can't be exiting at the same time.
5476 * Lock the parent list. No need to lock the child - not PID
5477 * hashed yet and not running, so nobody can access it.
5479 mutex_lock(&parent_ctx
->mutex
);
5482 * We dont have to disable NMIs - we are only looking at
5483 * the list, not manipulating it:
5485 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
5486 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5492 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
5493 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5499 child_ctx
= child
->perf_event_ctxp
;
5501 if (child_ctx
&& inherited_all
) {
5503 * Mark the child context as a clone of the parent
5504 * context, or of whatever the parent is a clone of.
5505 * Note that if the parent is a clone, it could get
5506 * uncloned at any point, but that doesn't matter
5507 * because the list of events and the generation
5508 * count can't have changed since we took the mutex.
5510 cloned_ctx
= rcu_dereference(parent_ctx
->parent_ctx
);
5512 child_ctx
->parent_ctx
= cloned_ctx
;
5513 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
5515 child_ctx
->parent_ctx
= parent_ctx
;
5516 child_ctx
->parent_gen
= parent_ctx
->generation
;
5518 get_ctx(child_ctx
->parent_ctx
);
5521 mutex_unlock(&parent_ctx
->mutex
);
5523 perf_unpin_context(parent_ctx
);
5528 static void __init
perf_event_init_all_cpus(void)
5531 struct perf_cpu_context
*cpuctx
;
5533 for_each_possible_cpu(cpu
) {
5534 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5535 mutex_init(&cpuctx
->hlist_mutex
);
5536 __perf_event_init_context(&cpuctx
->ctx
, NULL
);
5540 static void __cpuinit
perf_event_init_cpu(int cpu
)
5542 struct perf_cpu_context
*cpuctx
;
5544 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5546 spin_lock(&perf_resource_lock
);
5547 cpuctx
->max_pertask
= perf_max_events
- perf_reserved_percpu
;
5548 spin_unlock(&perf_resource_lock
);
5550 mutex_lock(&cpuctx
->hlist_mutex
);
5551 if (cpuctx
->hlist_refcount
> 0) {
5552 struct swevent_hlist
*hlist
;
5554 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5555 WARN_ON_ONCE(!hlist
);
5556 rcu_assign_pointer(cpuctx
->swevent_hlist
, hlist
);
5558 mutex_unlock(&cpuctx
->hlist_mutex
);
5561 #ifdef CONFIG_HOTPLUG_CPU
5562 static void __perf_event_exit_cpu(void *info
)
5564 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
5565 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5566 struct perf_event
*event
, *tmp
;
5568 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5569 __perf_event_remove_from_context(event
);
5570 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
5571 __perf_event_remove_from_context(event
);
5573 static void perf_event_exit_cpu(int cpu
)
5575 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5576 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5578 mutex_lock(&cpuctx
->hlist_mutex
);
5579 swevent_hlist_release(cpuctx
);
5580 mutex_unlock(&cpuctx
->hlist_mutex
);
5582 mutex_lock(&ctx
->mutex
);
5583 smp_call_function_single(cpu
, __perf_event_exit_cpu
, NULL
, 1);
5584 mutex_unlock(&ctx
->mutex
);
5587 static inline void perf_event_exit_cpu(int cpu
) { }
5590 static int __cpuinit
5591 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
5593 unsigned int cpu
= (long)hcpu
;
5597 case CPU_UP_PREPARE
:
5598 case CPU_UP_PREPARE_FROZEN
:
5599 perf_event_init_cpu(cpu
);
5602 case CPU_DOWN_PREPARE
:
5603 case CPU_DOWN_PREPARE_FROZEN
:
5604 perf_event_exit_cpu(cpu
);
5615 * This has to have a higher priority than migration_notifier in sched.c.
5617 static struct notifier_block __cpuinitdata perf_cpu_nb
= {
5618 .notifier_call
= perf_cpu_notify
,
5622 void __init
perf_event_init(void)
5624 perf_event_init_all_cpus();
5625 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_UP_PREPARE
,
5626 (void *)(long)smp_processor_id());
5627 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_ONLINE
,
5628 (void *)(long)smp_processor_id());
5629 register_cpu_notifier(&perf_cpu_nb
);
5632 static ssize_t
perf_show_reserve_percpu(struct sysdev_class
*class,
5633 struct sysdev_class_attribute
*attr
,
5636 return sprintf(buf
, "%d\n", perf_reserved_percpu
);
5640 perf_set_reserve_percpu(struct sysdev_class
*class,
5641 struct sysdev_class_attribute
*attr
,
5645 struct perf_cpu_context
*cpuctx
;
5649 err
= strict_strtoul(buf
, 10, &val
);
5652 if (val
> perf_max_events
)
5655 spin_lock(&perf_resource_lock
);
5656 perf_reserved_percpu
= val
;
5657 for_each_online_cpu(cpu
) {
5658 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5659 raw_spin_lock_irq(&cpuctx
->ctx
.lock
);
5660 mpt
= min(perf_max_events
- cpuctx
->ctx
.nr_events
,
5661 perf_max_events
- perf_reserved_percpu
);
5662 cpuctx
->max_pertask
= mpt
;
5663 raw_spin_unlock_irq(&cpuctx
->ctx
.lock
);
5665 spin_unlock(&perf_resource_lock
);
5670 static ssize_t
perf_show_overcommit(struct sysdev_class
*class,
5671 struct sysdev_class_attribute
*attr
,
5674 return sprintf(buf
, "%d\n", perf_overcommit
);
5678 perf_set_overcommit(struct sysdev_class
*class,
5679 struct sysdev_class_attribute
*attr
,
5680 const char *buf
, size_t count
)
5685 err
= strict_strtoul(buf
, 10, &val
);
5691 spin_lock(&perf_resource_lock
);
5692 perf_overcommit
= val
;
5693 spin_unlock(&perf_resource_lock
);
5698 static SYSDEV_CLASS_ATTR(
5701 perf_show_reserve_percpu
,
5702 perf_set_reserve_percpu
5705 static SYSDEV_CLASS_ATTR(
5708 perf_show_overcommit
,
5712 static struct attribute
*perfclass_attrs
[] = {
5713 &attr_reserve_percpu
.attr
,
5714 &attr_overcommit
.attr
,
5718 static struct attribute_group perfclass_attr_group
= {
5719 .attrs
= perfclass_attrs
,
5720 .name
= "perf_events",
5723 static int __init
perf_event_sysfs_init(void)
5725 return sysfs_create_group(&cpu_sysdev_class
.kset
.kobj
,
5726 &perfclass_attr_group
);
5728 device_initcall(perf_event_sysfs_init
);