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(); }
87 hw_perf_group_sched_in(struct perf_event
*group_leader
,
88 struct perf_cpu_context
*cpuctx
,
89 struct perf_event_context
*ctx
)
94 void __weak
perf_event_print_debug(void) { }
96 static DEFINE_PER_CPU(int, perf_disable_count
);
98 void perf_disable(void)
100 if (!__get_cpu_var(perf_disable_count
)++)
104 void perf_enable(void)
106 if (!--__get_cpu_var(perf_disable_count
))
110 static void get_ctx(struct perf_event_context
*ctx
)
112 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
115 static void free_ctx(struct rcu_head
*head
)
117 struct perf_event_context
*ctx
;
119 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
123 static void put_ctx(struct perf_event_context
*ctx
)
125 if (atomic_dec_and_test(&ctx
->refcount
)) {
127 put_ctx(ctx
->parent_ctx
);
129 put_task_struct(ctx
->task
);
130 call_rcu(&ctx
->rcu_head
, free_ctx
);
134 static void unclone_ctx(struct perf_event_context
*ctx
)
136 if (ctx
->parent_ctx
) {
137 put_ctx(ctx
->parent_ctx
);
138 ctx
->parent_ctx
= NULL
;
143 * If we inherit events we want to return the parent event id
146 static u64
primary_event_id(struct perf_event
*event
)
151 id
= event
->parent
->id
;
157 * Get the perf_event_context for a task and lock it.
158 * This has to cope with with the fact that until it is locked,
159 * the context could get moved to another task.
161 static struct perf_event_context
*
162 perf_lock_task_context(struct task_struct
*task
, unsigned long *flags
)
164 struct perf_event_context
*ctx
;
168 ctx
= rcu_dereference(task
->perf_event_ctxp
);
171 * If this context is a clone of another, it might
172 * get swapped for another underneath us by
173 * perf_event_task_sched_out, though the
174 * rcu_read_lock() protects us from any context
175 * getting freed. Lock the context and check if it
176 * got swapped before we could get the lock, and retry
177 * if so. If we locked the right context, then it
178 * can't get swapped on us any more.
180 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
181 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
)) {
182 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
186 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
187 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
196 * Get the context for a task and increment its pin_count so it
197 * can't get swapped to another task. This also increments its
198 * reference count so that the context can't get freed.
200 static struct perf_event_context
*perf_pin_task_context(struct task_struct
*task
)
202 struct perf_event_context
*ctx
;
205 ctx
= perf_lock_task_context(task
, &flags
);
208 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
213 static void perf_unpin_context(struct perf_event_context
*ctx
)
217 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
219 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
223 static inline u64
perf_clock(void)
225 return cpu_clock(raw_smp_processor_id());
229 * Update the record of the current time in a context.
231 static void update_context_time(struct perf_event_context
*ctx
)
233 u64 now
= perf_clock();
235 ctx
->time
+= now
- ctx
->timestamp
;
236 ctx
->timestamp
= now
;
240 * Update the total_time_enabled and total_time_running fields for a event.
242 static void update_event_times(struct perf_event
*event
)
244 struct perf_event_context
*ctx
= event
->ctx
;
247 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
248 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
254 run_end
= event
->tstamp_stopped
;
256 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
258 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
259 run_end
= event
->tstamp_stopped
;
263 event
->total_time_running
= run_end
- event
->tstamp_running
;
266 static struct list_head
*
267 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
269 if (event
->attr
.pinned
)
270 return &ctx
->pinned_groups
;
272 return &ctx
->flexible_groups
;
276 * Add a event from the lists for its context.
277 * Must be called with ctx->mutex and ctx->lock held.
280 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
282 struct perf_event
*group_leader
= event
->group_leader
;
285 * Depending on whether it is a standalone or sibling event,
286 * add it straight to the context's event list, or to the group
287 * leader's sibling list:
289 if (group_leader
== event
) {
290 struct list_head
*list
;
292 if (is_software_event(event
))
293 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
295 list
= ctx_group_list(event
, ctx
);
296 list_add_tail(&event
->group_entry
, list
);
298 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
299 !is_software_event(event
))
300 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
302 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
303 group_leader
->nr_siblings
++;
306 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
308 if (event
->attr
.inherit_stat
)
313 * Remove a event from the lists for its context.
314 * Must be called with ctx->mutex and ctx->lock held.
317 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
319 struct perf_event
*sibling
, *tmp
;
321 if (list_empty(&event
->group_entry
))
324 if (event
->attr
.inherit_stat
)
327 list_del_init(&event
->group_entry
);
328 list_del_rcu(&event
->event_entry
);
330 if (event
->group_leader
!= event
)
331 event
->group_leader
->nr_siblings
--;
333 update_event_times(event
);
336 * If event was in error state, then keep it
337 * that way, otherwise bogus counts will be
338 * returned on read(). The only way to get out
339 * of error state is by explicit re-enabling
342 if (event
->state
> PERF_EVENT_STATE_OFF
)
343 event
->state
= PERF_EVENT_STATE_OFF
;
346 * If this was a group event with sibling events then
347 * upgrade the siblings to singleton events by adding them
348 * to the context list directly:
350 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
351 struct list_head
*list
;
353 list
= ctx_group_list(event
, ctx
);
354 list_move_tail(&sibling
->group_entry
, list
);
355 sibling
->group_leader
= sibling
;
357 /* Inherit group flags from the previous leader */
358 sibling
->group_flags
= event
->group_flags
;
363 event_sched_out(struct perf_event
*event
,
364 struct perf_cpu_context
*cpuctx
,
365 struct perf_event_context
*ctx
)
367 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
370 event
->state
= PERF_EVENT_STATE_INACTIVE
;
371 if (event
->pending_disable
) {
372 event
->pending_disable
= 0;
373 event
->state
= PERF_EVENT_STATE_OFF
;
375 event
->tstamp_stopped
= ctx
->time
;
376 event
->pmu
->disable(event
);
379 if (!is_software_event(event
))
380 cpuctx
->active_oncpu
--;
382 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
383 cpuctx
->exclusive
= 0;
387 group_sched_out(struct perf_event
*group_event
,
388 struct perf_cpu_context
*cpuctx
,
389 struct perf_event_context
*ctx
)
391 struct perf_event
*event
;
393 if (group_event
->state
!= PERF_EVENT_STATE_ACTIVE
)
396 event_sched_out(group_event
, cpuctx
, ctx
);
399 * Schedule out siblings (if any):
401 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
402 event_sched_out(event
, cpuctx
, ctx
);
404 if (group_event
->attr
.exclusive
)
405 cpuctx
->exclusive
= 0;
409 * Cross CPU call to remove a performance event
411 * We disable the event on the hardware level first. After that we
412 * remove it from the context list.
414 static void __perf_event_remove_from_context(void *info
)
416 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
417 struct perf_event
*event
= info
;
418 struct perf_event_context
*ctx
= event
->ctx
;
421 * If this is a task context, we need to check whether it is
422 * the current task context of this cpu. If not it has been
423 * scheduled out before the smp call arrived.
425 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
428 raw_spin_lock(&ctx
->lock
);
430 * Protect the list operation against NMI by disabling the
431 * events on a global level.
435 event_sched_out(event
, cpuctx
, ctx
);
437 list_del_event(event
, ctx
);
441 * Allow more per task events with respect to the
444 cpuctx
->max_pertask
=
445 min(perf_max_events
- ctx
->nr_events
,
446 perf_max_events
- perf_reserved_percpu
);
450 raw_spin_unlock(&ctx
->lock
);
455 * Remove the event from a task's (or a CPU's) list of events.
457 * Must be called with ctx->mutex held.
459 * CPU events are removed with a smp call. For task events we only
460 * call when the task is on a CPU.
462 * If event->ctx is a cloned context, callers must make sure that
463 * every task struct that event->ctx->task could possibly point to
464 * remains valid. This is OK when called from perf_release since
465 * that only calls us on the top-level context, which can't be a clone.
466 * When called from perf_event_exit_task, it's OK because the
467 * context has been detached from its task.
469 static void perf_event_remove_from_context(struct perf_event
*event
)
471 struct perf_event_context
*ctx
= event
->ctx
;
472 struct task_struct
*task
= ctx
->task
;
476 * Per cpu events are removed via an smp call and
477 * the removal is always successful.
479 smp_call_function_single(event
->cpu
,
480 __perf_event_remove_from_context
,
486 task_oncpu_function_call(task
, __perf_event_remove_from_context
,
489 raw_spin_lock_irq(&ctx
->lock
);
491 * If the context is active we need to retry the smp call.
493 if (ctx
->nr_active
&& !list_empty(&event
->group_entry
)) {
494 raw_spin_unlock_irq(&ctx
->lock
);
499 * The lock prevents that this context is scheduled in so we
500 * can remove the event safely, if the call above did not
503 if (!list_empty(&event
->group_entry
))
504 list_del_event(event
, ctx
);
505 raw_spin_unlock_irq(&ctx
->lock
);
509 * Update total_time_enabled and total_time_running for all events in a group.
511 static void update_group_times(struct perf_event
*leader
)
513 struct perf_event
*event
;
515 update_event_times(leader
);
516 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
517 update_event_times(event
);
521 * Cross CPU call to disable a performance event
523 static void __perf_event_disable(void *info
)
525 struct perf_event
*event
= info
;
526 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
527 struct perf_event_context
*ctx
= event
->ctx
;
530 * If this is a per-task event, need to check whether this
531 * event's task is the current task on this cpu.
533 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
536 raw_spin_lock(&ctx
->lock
);
539 * If the event is on, turn it off.
540 * If it is in error state, leave it in error state.
542 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
543 update_context_time(ctx
);
544 update_group_times(event
);
545 if (event
== event
->group_leader
)
546 group_sched_out(event
, cpuctx
, ctx
);
548 event_sched_out(event
, cpuctx
, ctx
);
549 event
->state
= PERF_EVENT_STATE_OFF
;
552 raw_spin_unlock(&ctx
->lock
);
558 * If event->ctx is a cloned context, callers must make sure that
559 * every task struct that event->ctx->task could possibly point to
560 * remains valid. This condition is satisifed when called through
561 * perf_event_for_each_child or perf_event_for_each because they
562 * hold the top-level event's child_mutex, so any descendant that
563 * goes to exit will block in sync_child_event.
564 * When called from perf_pending_event it's OK because event->ctx
565 * is the current context on this CPU and preemption is disabled,
566 * hence we can't get into perf_event_task_sched_out for this context.
568 void perf_event_disable(struct perf_event
*event
)
570 struct perf_event_context
*ctx
= event
->ctx
;
571 struct task_struct
*task
= ctx
->task
;
575 * Disable the event on the cpu that it's on
577 smp_call_function_single(event
->cpu
, __perf_event_disable
,
583 task_oncpu_function_call(task
, __perf_event_disable
, event
);
585 raw_spin_lock_irq(&ctx
->lock
);
587 * If the event is still active, we need to retry the cross-call.
589 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
590 raw_spin_unlock_irq(&ctx
->lock
);
595 * Since we have the lock this context can't be scheduled
596 * in, so we can change the state safely.
598 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
599 update_group_times(event
);
600 event
->state
= PERF_EVENT_STATE_OFF
;
603 raw_spin_unlock_irq(&ctx
->lock
);
607 event_sched_in(struct perf_event
*event
,
608 struct perf_cpu_context
*cpuctx
,
609 struct perf_event_context
*ctx
)
611 if (event
->state
<= PERF_EVENT_STATE_OFF
)
614 event
->state
= PERF_EVENT_STATE_ACTIVE
;
615 event
->oncpu
= smp_processor_id();
617 * The new state must be visible before we turn it on in the hardware:
621 if (event
->pmu
->enable(event
)) {
622 event
->state
= PERF_EVENT_STATE_INACTIVE
;
627 event
->tstamp_running
+= ctx
->time
- event
->tstamp_stopped
;
629 if (!is_software_event(event
))
630 cpuctx
->active_oncpu
++;
633 if (event
->attr
.exclusive
)
634 cpuctx
->exclusive
= 1;
640 group_sched_in(struct perf_event
*group_event
,
641 struct perf_cpu_context
*cpuctx
,
642 struct perf_event_context
*ctx
)
644 struct perf_event
*event
, *partial_group
;
647 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
650 ret
= hw_perf_group_sched_in(group_event
, cpuctx
, ctx
);
652 return ret
< 0 ? ret
: 0;
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
;
671 * Groups can be scheduled in as one unit only, so undo any
672 * partial group before returning:
674 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
675 if (event
== partial_group
)
677 event_sched_out(event
, cpuctx
, ctx
);
679 event_sched_out(group_event
, cpuctx
, ctx
);
685 * Work out whether we can put this event group on the CPU now.
687 static int group_can_go_on(struct perf_event
*event
,
688 struct perf_cpu_context
*cpuctx
,
692 * Groups consisting entirely of software events can always go on.
694 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
697 * If an exclusive group is already on, no other hardware
700 if (cpuctx
->exclusive
)
703 * If this group is exclusive and there are already
704 * events on the CPU, it can't go on.
706 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
709 * Otherwise, try to add it if all previous groups were able
715 static void add_event_to_ctx(struct perf_event
*event
,
716 struct perf_event_context
*ctx
)
718 list_add_event(event
, ctx
);
719 event
->tstamp_enabled
= ctx
->time
;
720 event
->tstamp_running
= ctx
->time
;
721 event
->tstamp_stopped
= ctx
->time
;
725 * Cross CPU call to install and enable a performance event
727 * Must be called with ctx->mutex held
729 static void __perf_install_in_context(void *info
)
731 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
732 struct perf_event
*event
= info
;
733 struct perf_event_context
*ctx
= event
->ctx
;
734 struct perf_event
*leader
= event
->group_leader
;
738 * If this is a task context, we need to check whether it is
739 * the current task context of this cpu. If not it has been
740 * scheduled out before the smp call arrived.
741 * Or possibly this is the right context but it isn't
742 * on this cpu because it had no events.
744 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
745 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
747 cpuctx
->task_ctx
= ctx
;
750 raw_spin_lock(&ctx
->lock
);
752 update_context_time(ctx
);
755 * Protect the list operation against NMI by disabling the
756 * events on a global level. NOP for non NMI based events.
760 add_event_to_ctx(event
, ctx
);
762 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
766 * Don't put the event on if it is disabled or if
767 * it is in a group and the group isn't on.
769 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
770 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
774 * An exclusive event can't go on if there are already active
775 * hardware events, and no hardware event can go on if there
776 * is already an exclusive event on.
778 if (!group_can_go_on(event
, cpuctx
, 1))
781 err
= event_sched_in(event
, cpuctx
, ctx
);
785 * This event couldn't go on. If it is in a group
786 * then we have to pull the whole group off.
787 * If the event group is pinned then put it in error state.
790 group_sched_out(leader
, cpuctx
, ctx
);
791 if (leader
->attr
.pinned
) {
792 update_group_times(leader
);
793 leader
->state
= PERF_EVENT_STATE_ERROR
;
797 if (!err
&& !ctx
->task
&& cpuctx
->max_pertask
)
798 cpuctx
->max_pertask
--;
803 raw_spin_unlock(&ctx
->lock
);
807 * Attach a performance event to a context
809 * First we add the event to the list with the hardware enable bit
810 * in event->hw_config cleared.
812 * If the event is attached to a task which is on a CPU we use a smp
813 * call to enable it in the task context. The task might have been
814 * scheduled away, but we check this in the smp call again.
816 * Must be called with ctx->mutex held.
819 perf_install_in_context(struct perf_event_context
*ctx
,
820 struct perf_event
*event
,
823 struct task_struct
*task
= ctx
->task
;
827 * Per cpu events are installed via an smp call and
828 * the install is always successful.
830 smp_call_function_single(cpu
, __perf_install_in_context
,
836 task_oncpu_function_call(task
, __perf_install_in_context
,
839 raw_spin_lock_irq(&ctx
->lock
);
841 * we need to retry the smp call.
843 if (ctx
->is_active
&& list_empty(&event
->group_entry
)) {
844 raw_spin_unlock_irq(&ctx
->lock
);
849 * The lock prevents that this context is scheduled in so we
850 * can add the event safely, if it the call above did not
853 if (list_empty(&event
->group_entry
))
854 add_event_to_ctx(event
, ctx
);
855 raw_spin_unlock_irq(&ctx
->lock
);
859 * Put a event into inactive state and update time fields.
860 * Enabling the leader of a group effectively enables all
861 * the group members that aren't explicitly disabled, so we
862 * have to update their ->tstamp_enabled also.
863 * Note: this works for group members as well as group leaders
864 * since the non-leader members' sibling_lists will be empty.
866 static void __perf_event_mark_enabled(struct perf_event
*event
,
867 struct perf_event_context
*ctx
)
869 struct perf_event
*sub
;
871 event
->state
= PERF_EVENT_STATE_INACTIVE
;
872 event
->tstamp_enabled
= ctx
->time
- event
->total_time_enabled
;
873 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
)
874 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
875 sub
->tstamp_enabled
=
876 ctx
->time
- sub
->total_time_enabled
;
880 * Cross CPU call to enable a performance event
882 static void __perf_event_enable(void *info
)
884 struct perf_event
*event
= info
;
885 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
886 struct perf_event_context
*ctx
= event
->ctx
;
887 struct perf_event
*leader
= event
->group_leader
;
891 * If this is a per-task event, need to check whether this
892 * event's task is the current task on this cpu.
894 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
895 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
897 cpuctx
->task_ctx
= ctx
;
900 raw_spin_lock(&ctx
->lock
);
902 update_context_time(ctx
);
904 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
906 __perf_event_mark_enabled(event
, ctx
);
908 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
912 * If the event is in a group and isn't the group leader,
913 * then don't put it on unless the group is on.
915 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
918 if (!group_can_go_on(event
, cpuctx
, 1)) {
923 err
= group_sched_in(event
, cpuctx
, ctx
);
925 err
= event_sched_in(event
, cpuctx
, ctx
);
931 * If this event can't go on and it's part of a
932 * group, then the whole group has to come off.
935 group_sched_out(leader
, cpuctx
, ctx
);
936 if (leader
->attr
.pinned
) {
937 update_group_times(leader
);
938 leader
->state
= PERF_EVENT_STATE_ERROR
;
943 raw_spin_unlock(&ctx
->lock
);
949 * If event->ctx is a cloned context, callers must make sure that
950 * every task struct that event->ctx->task could possibly point to
951 * remains valid. This condition is satisfied when called through
952 * perf_event_for_each_child or perf_event_for_each as described
953 * for perf_event_disable.
955 void perf_event_enable(struct perf_event
*event
)
957 struct perf_event_context
*ctx
= event
->ctx
;
958 struct task_struct
*task
= ctx
->task
;
962 * Enable the event on the cpu that it's on
964 smp_call_function_single(event
->cpu
, __perf_event_enable
,
969 raw_spin_lock_irq(&ctx
->lock
);
970 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
974 * If the event is in error state, clear that first.
975 * That way, if we see the event in error state below, we
976 * know that it has gone back into error state, as distinct
977 * from the task having been scheduled away before the
978 * cross-call arrived.
980 if (event
->state
== PERF_EVENT_STATE_ERROR
)
981 event
->state
= PERF_EVENT_STATE_OFF
;
984 raw_spin_unlock_irq(&ctx
->lock
);
985 task_oncpu_function_call(task
, __perf_event_enable
, event
);
987 raw_spin_lock_irq(&ctx
->lock
);
990 * If the context is active and the event is still off,
991 * we need to retry the cross-call.
993 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
)
997 * Since we have the lock this context can't be scheduled
998 * in, so we can change the state safely.
1000 if (event
->state
== PERF_EVENT_STATE_OFF
)
1001 __perf_event_mark_enabled(event
, ctx
);
1004 raw_spin_unlock_irq(&ctx
->lock
);
1007 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1010 * not supported on inherited events
1012 if (event
->attr
.inherit
)
1015 atomic_add(refresh
, &event
->event_limit
);
1016 perf_event_enable(event
);
1022 EVENT_FLEXIBLE
= 0x1,
1024 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
1027 static void ctx_sched_out(struct perf_event_context
*ctx
,
1028 struct perf_cpu_context
*cpuctx
,
1029 enum event_type_t event_type
)
1031 struct perf_event
*event
;
1033 raw_spin_lock(&ctx
->lock
);
1035 if (likely(!ctx
->nr_events
))
1037 update_context_time(ctx
);
1040 if (!ctx
->nr_active
)
1043 if (event_type
& EVENT_PINNED
)
1044 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1045 group_sched_out(event
, cpuctx
, ctx
);
1047 if (event_type
& EVENT_FLEXIBLE
)
1048 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1049 group_sched_out(event
, cpuctx
, ctx
);
1054 raw_spin_unlock(&ctx
->lock
);
1058 * Test whether two contexts are equivalent, i.e. whether they
1059 * have both been cloned from the same version of the same context
1060 * and they both have the same number of enabled events.
1061 * If the number of enabled events is the same, then the set
1062 * of enabled events should be the same, because these are both
1063 * inherited contexts, therefore we can't access individual events
1064 * in them directly with an fd; we can only enable/disable all
1065 * events via prctl, or enable/disable all events in a family
1066 * via ioctl, which will have the same effect on both contexts.
1068 static int context_equiv(struct perf_event_context
*ctx1
,
1069 struct perf_event_context
*ctx2
)
1071 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1072 && ctx1
->parent_gen
== ctx2
->parent_gen
1073 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1076 static void __perf_event_sync_stat(struct perf_event
*event
,
1077 struct perf_event
*next_event
)
1081 if (!event
->attr
.inherit_stat
)
1085 * Update the event value, we cannot use perf_event_read()
1086 * because we're in the middle of a context switch and have IRQs
1087 * disabled, which upsets smp_call_function_single(), however
1088 * we know the event must be on the current CPU, therefore we
1089 * don't need to use it.
1091 switch (event
->state
) {
1092 case PERF_EVENT_STATE_ACTIVE
:
1093 event
->pmu
->read(event
);
1096 case PERF_EVENT_STATE_INACTIVE
:
1097 update_event_times(event
);
1105 * In order to keep per-task stats reliable we need to flip the event
1106 * values when we flip the contexts.
1108 value
= atomic64_read(&next_event
->count
);
1109 value
= atomic64_xchg(&event
->count
, value
);
1110 atomic64_set(&next_event
->count
, value
);
1112 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1113 swap(event
->total_time_running
, next_event
->total_time_running
);
1116 * Since we swizzled the values, update the user visible data too.
1118 perf_event_update_userpage(event
);
1119 perf_event_update_userpage(next_event
);
1122 #define list_next_entry(pos, member) \
1123 list_entry(pos->member.next, typeof(*pos), member)
1125 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1126 struct perf_event_context
*next_ctx
)
1128 struct perf_event
*event
, *next_event
;
1133 update_context_time(ctx
);
1135 event
= list_first_entry(&ctx
->event_list
,
1136 struct perf_event
, event_entry
);
1138 next_event
= list_first_entry(&next_ctx
->event_list
,
1139 struct perf_event
, event_entry
);
1141 while (&event
->event_entry
!= &ctx
->event_list
&&
1142 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1144 __perf_event_sync_stat(event
, next_event
);
1146 event
= list_next_entry(event
, event_entry
);
1147 next_event
= list_next_entry(next_event
, event_entry
);
1152 * Called from scheduler to remove the events of the current task,
1153 * with interrupts disabled.
1155 * We stop each event and update the event value in event->count.
1157 * This does not protect us against NMI, but disable()
1158 * sets the disabled bit in the control field of event _before_
1159 * accessing the event control register. If a NMI hits, then it will
1160 * not restart the event.
1162 void perf_event_task_sched_out(struct task_struct
*task
,
1163 struct task_struct
*next
)
1165 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1166 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1167 struct perf_event_context
*next_ctx
;
1168 struct perf_event_context
*parent
;
1171 perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES
, 1, 1, NULL
, 0);
1173 if (likely(!ctx
|| !cpuctx
->task_ctx
))
1177 parent
= rcu_dereference(ctx
->parent_ctx
);
1178 next_ctx
= next
->perf_event_ctxp
;
1179 if (parent
&& next_ctx
&&
1180 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1182 * Looks like the two contexts are clones, so we might be
1183 * able to optimize the context switch. We lock both
1184 * contexts and check that they are clones under the
1185 * lock (including re-checking that neither has been
1186 * uncloned in the meantime). It doesn't matter which
1187 * order we take the locks because no other cpu could
1188 * be trying to lock both of these tasks.
1190 raw_spin_lock(&ctx
->lock
);
1191 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1192 if (context_equiv(ctx
, next_ctx
)) {
1194 * XXX do we need a memory barrier of sorts
1195 * wrt to rcu_dereference() of perf_event_ctxp
1197 task
->perf_event_ctxp
= next_ctx
;
1198 next
->perf_event_ctxp
= ctx
;
1200 next_ctx
->task
= task
;
1203 perf_event_sync_stat(ctx
, next_ctx
);
1205 raw_spin_unlock(&next_ctx
->lock
);
1206 raw_spin_unlock(&ctx
->lock
);
1211 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1212 cpuctx
->task_ctx
= NULL
;
1216 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1217 enum event_type_t event_type
)
1219 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1221 if (!cpuctx
->task_ctx
)
1224 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1227 ctx_sched_out(ctx
, cpuctx
, event_type
);
1228 cpuctx
->task_ctx
= NULL
;
1232 * Called with IRQs disabled
1234 static void __perf_event_task_sched_out(struct perf_event_context
*ctx
)
1236 task_ctx_sched_out(ctx
, EVENT_ALL
);
1240 * Called with IRQs disabled
1242 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1243 enum event_type_t event_type
)
1245 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1249 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1250 struct perf_cpu_context
*cpuctx
)
1252 struct perf_event
*event
;
1254 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1255 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1257 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1260 if (group_can_go_on(event
, cpuctx
, 1))
1261 group_sched_in(event
, cpuctx
, ctx
);
1264 * If this pinned group hasn't been scheduled,
1265 * put it in error state.
1267 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1268 update_group_times(event
);
1269 event
->state
= PERF_EVENT_STATE_ERROR
;
1275 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
1276 struct perf_cpu_context
*cpuctx
)
1278 struct perf_event
*event
;
1281 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1282 /* Ignore events in OFF or ERROR state */
1283 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1286 * Listen to the 'cpu' scheduling filter constraint
1289 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1292 if (group_can_go_on(event
, cpuctx
, can_add_hw
))
1293 if (group_sched_in(event
, cpuctx
, ctx
))
1299 ctx_sched_in(struct perf_event_context
*ctx
,
1300 struct perf_cpu_context
*cpuctx
,
1301 enum event_type_t event_type
)
1303 raw_spin_lock(&ctx
->lock
);
1305 if (likely(!ctx
->nr_events
))
1308 ctx
->timestamp
= perf_clock();
1313 * First go through the list and put on any pinned groups
1314 * in order to give them the best chance of going on.
1316 if (event_type
& EVENT_PINNED
)
1317 ctx_pinned_sched_in(ctx
, cpuctx
);
1319 /* Then walk through the lower prio flexible groups */
1320 if (event_type
& EVENT_FLEXIBLE
)
1321 ctx_flexible_sched_in(ctx
, cpuctx
);
1325 raw_spin_unlock(&ctx
->lock
);
1328 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
1329 enum event_type_t event_type
)
1331 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
1333 ctx_sched_in(ctx
, cpuctx
, event_type
);
1336 static void task_ctx_sched_in(struct task_struct
*task
,
1337 enum event_type_t event_type
)
1339 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1340 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1344 if (cpuctx
->task_ctx
== ctx
)
1346 ctx_sched_in(ctx
, cpuctx
, event_type
);
1347 cpuctx
->task_ctx
= ctx
;
1350 * Called from scheduler to add the events of the current task
1351 * with interrupts disabled.
1353 * We restore the event value and then enable it.
1355 * This does not protect us against NMI, but enable()
1356 * sets the enabled bit in the control field of event _before_
1357 * accessing the event control register. If a NMI hits, then it will
1358 * keep the event running.
1360 void perf_event_task_sched_in(struct task_struct
*task
)
1362 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1363 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
1368 if (cpuctx
->task_ctx
== ctx
)
1374 * We want to keep the following priority order:
1375 * cpu pinned (that don't need to move), task pinned,
1376 * cpu flexible, task flexible.
1378 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1380 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
);
1381 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1382 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
);
1384 cpuctx
->task_ctx
= ctx
;
1389 #define MAX_INTERRUPTS (~0ULL)
1391 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1393 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1395 u64 frequency
= event
->attr
.sample_freq
;
1396 u64 sec
= NSEC_PER_SEC
;
1397 u64 divisor
, dividend
;
1399 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
1401 count_fls
= fls64(count
);
1402 nsec_fls
= fls64(nsec
);
1403 frequency_fls
= fls64(frequency
);
1407 * We got @count in @nsec, with a target of sample_freq HZ
1408 * the target period becomes:
1411 * period = -------------------
1412 * @nsec * sample_freq
1417 * Reduce accuracy by one bit such that @a and @b converge
1418 * to a similar magnitude.
1420 #define REDUCE_FLS(a, b) \
1422 if (a##_fls > b##_fls) { \
1432 * Reduce accuracy until either term fits in a u64, then proceed with
1433 * the other, so that finally we can do a u64/u64 division.
1435 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
1436 REDUCE_FLS(nsec
, frequency
);
1437 REDUCE_FLS(sec
, count
);
1440 if (count_fls
+ sec_fls
> 64) {
1441 divisor
= nsec
* frequency
;
1443 while (count_fls
+ sec_fls
> 64) {
1444 REDUCE_FLS(count
, sec
);
1448 dividend
= count
* sec
;
1450 dividend
= count
* sec
;
1452 while (nsec_fls
+ frequency_fls
> 64) {
1453 REDUCE_FLS(nsec
, frequency
);
1457 divisor
= nsec
* frequency
;
1460 return div64_u64(dividend
, divisor
);
1463 static void perf_event_stop(struct perf_event
*event
)
1465 if (!event
->pmu
->stop
)
1466 return event
->pmu
->disable(event
);
1468 return event
->pmu
->stop(event
);
1471 static int perf_event_start(struct perf_event
*event
)
1473 if (!event
->pmu
->start
)
1474 return event
->pmu
->enable(event
);
1476 return event
->pmu
->start(event
);
1479 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1481 struct hw_perf_event
*hwc
= &event
->hw
;
1482 u64 period
, sample_period
;
1485 period
= perf_calculate_period(event
, nsec
, count
);
1487 delta
= (s64
)(period
- hwc
->sample_period
);
1488 delta
= (delta
+ 7) / 8; /* low pass filter */
1490 sample_period
= hwc
->sample_period
+ delta
;
1495 hwc
->sample_period
= sample_period
;
1497 if (atomic64_read(&hwc
->period_left
) > 8*sample_period
) {
1499 perf_event_stop(event
);
1500 atomic64_set(&hwc
->period_left
, 0);
1501 perf_event_start(event
);
1506 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
)
1508 struct perf_event
*event
;
1509 struct hw_perf_event
*hwc
;
1510 u64 interrupts
, now
;
1513 raw_spin_lock(&ctx
->lock
);
1514 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
1515 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1518 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1523 interrupts
= hwc
->interrupts
;
1524 hwc
->interrupts
= 0;
1527 * unthrottle events on the tick
1529 if (interrupts
== MAX_INTERRUPTS
) {
1530 perf_log_throttle(event
, 1);
1532 event
->pmu
->unthrottle(event
);
1536 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
1540 event
->pmu
->read(event
);
1541 now
= atomic64_read(&event
->count
);
1542 delta
= now
- hwc
->freq_count_stamp
;
1543 hwc
->freq_count_stamp
= now
;
1546 perf_adjust_period(event
, TICK_NSEC
, delta
);
1549 raw_spin_unlock(&ctx
->lock
);
1553 * Round-robin a context's events:
1555 static void rotate_ctx(struct perf_event_context
*ctx
)
1557 raw_spin_lock(&ctx
->lock
);
1559 /* Rotate the first entry last of non-pinned groups */
1560 list_rotate_left(&ctx
->flexible_groups
);
1562 raw_spin_unlock(&ctx
->lock
);
1565 void perf_event_task_tick(struct task_struct
*curr
)
1567 struct perf_cpu_context
*cpuctx
;
1568 struct perf_event_context
*ctx
;
1571 if (!atomic_read(&nr_events
))
1574 cpuctx
= &__get_cpu_var(perf_cpu_context
);
1575 if (cpuctx
->ctx
.nr_events
&&
1576 cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
1579 ctx
= curr
->perf_event_ctxp
;
1580 if (ctx
&& ctx
->nr_events
&& ctx
->nr_events
!= ctx
->nr_active
)
1583 perf_ctx_adjust_freq(&cpuctx
->ctx
);
1585 perf_ctx_adjust_freq(ctx
);
1591 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1593 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
1595 rotate_ctx(&cpuctx
->ctx
);
1599 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1601 task_ctx_sched_in(curr
, EVENT_FLEXIBLE
);
1605 static int event_enable_on_exec(struct perf_event
*event
,
1606 struct perf_event_context
*ctx
)
1608 if (!event
->attr
.enable_on_exec
)
1611 event
->attr
.enable_on_exec
= 0;
1612 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1615 __perf_event_mark_enabled(event
, ctx
);
1621 * Enable all of a task's events that have been marked enable-on-exec.
1622 * This expects task == current.
1624 static void perf_event_enable_on_exec(struct task_struct
*task
)
1626 struct perf_event_context
*ctx
;
1627 struct perf_event
*event
;
1628 unsigned long flags
;
1632 local_irq_save(flags
);
1633 ctx
= task
->perf_event_ctxp
;
1634 if (!ctx
|| !ctx
->nr_events
)
1637 __perf_event_task_sched_out(ctx
);
1639 raw_spin_lock(&ctx
->lock
);
1641 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1642 ret
= event_enable_on_exec(event
, ctx
);
1647 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1648 ret
= event_enable_on_exec(event
, ctx
);
1654 * Unclone this context if we enabled any event.
1659 raw_spin_unlock(&ctx
->lock
);
1661 perf_event_task_sched_in(task
);
1663 local_irq_restore(flags
);
1667 * Cross CPU call to read the hardware event
1669 static void __perf_event_read(void *info
)
1671 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
1672 struct perf_event
*event
= info
;
1673 struct perf_event_context
*ctx
= event
->ctx
;
1676 * If this is a task context, we need to check whether it is
1677 * the current task context of this cpu. If not it has been
1678 * scheduled out before the smp call arrived. In that case
1679 * event->count would have been updated to a recent sample
1680 * when the event was scheduled out.
1682 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1685 raw_spin_lock(&ctx
->lock
);
1686 update_context_time(ctx
);
1687 update_event_times(event
);
1688 raw_spin_unlock(&ctx
->lock
);
1690 event
->pmu
->read(event
);
1693 static u64
perf_event_read(struct perf_event
*event
)
1696 * If event is enabled and currently active on a CPU, update the
1697 * value in the event structure:
1699 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1700 smp_call_function_single(event
->oncpu
,
1701 __perf_event_read
, event
, 1);
1702 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1703 struct perf_event_context
*ctx
= event
->ctx
;
1704 unsigned long flags
;
1706 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1707 update_context_time(ctx
);
1708 update_event_times(event
);
1709 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1712 return atomic64_read(&event
->count
);
1716 * Initialize the perf_event context in a task_struct:
1719 __perf_event_init_context(struct perf_event_context
*ctx
,
1720 struct task_struct
*task
)
1722 raw_spin_lock_init(&ctx
->lock
);
1723 mutex_init(&ctx
->mutex
);
1724 INIT_LIST_HEAD(&ctx
->pinned_groups
);
1725 INIT_LIST_HEAD(&ctx
->flexible_groups
);
1726 INIT_LIST_HEAD(&ctx
->event_list
);
1727 atomic_set(&ctx
->refcount
, 1);
1731 static struct perf_event_context
*find_get_context(pid_t pid
, int cpu
)
1733 struct perf_event_context
*ctx
;
1734 struct perf_cpu_context
*cpuctx
;
1735 struct task_struct
*task
;
1736 unsigned long flags
;
1739 if (pid
== -1 && cpu
!= -1) {
1740 /* Must be root to operate on a CPU event: */
1741 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
1742 return ERR_PTR(-EACCES
);
1744 if (cpu
< 0 || cpu
>= nr_cpumask_bits
)
1745 return ERR_PTR(-EINVAL
);
1748 * We could be clever and allow to attach a event to an
1749 * offline CPU and activate it when the CPU comes up, but
1752 if (!cpu_online(cpu
))
1753 return ERR_PTR(-ENODEV
);
1755 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
1766 task
= find_task_by_vpid(pid
);
1768 get_task_struct(task
);
1772 return ERR_PTR(-ESRCH
);
1775 * Can't attach events to a dying task.
1778 if (task
->flags
& PF_EXITING
)
1781 /* Reuse ptrace permission checks for now. */
1783 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
1787 ctx
= perf_lock_task_context(task
, &flags
);
1790 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1794 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
1798 __perf_event_init_context(ctx
, task
);
1800 if (cmpxchg(&task
->perf_event_ctxp
, NULL
, ctx
)) {
1802 * We raced with some other task; use
1803 * the context they set.
1808 get_task_struct(task
);
1811 put_task_struct(task
);
1815 put_task_struct(task
);
1816 return ERR_PTR(err
);
1819 static void perf_event_free_filter(struct perf_event
*event
);
1821 static void free_event_rcu(struct rcu_head
*head
)
1823 struct perf_event
*event
;
1825 event
= container_of(head
, struct perf_event
, rcu_head
);
1827 put_pid_ns(event
->ns
);
1828 perf_event_free_filter(event
);
1832 static void perf_pending_sync(struct perf_event
*event
);
1834 static void free_event(struct perf_event
*event
)
1836 perf_pending_sync(event
);
1838 if (!event
->parent
) {
1839 atomic_dec(&nr_events
);
1840 if (event
->attr
.mmap
)
1841 atomic_dec(&nr_mmap_events
);
1842 if (event
->attr
.comm
)
1843 atomic_dec(&nr_comm_events
);
1844 if (event
->attr
.task
)
1845 atomic_dec(&nr_task_events
);
1848 if (event
->output
) {
1849 fput(event
->output
->filp
);
1850 event
->output
= NULL
;
1854 event
->destroy(event
);
1856 put_ctx(event
->ctx
);
1857 call_rcu(&event
->rcu_head
, free_event_rcu
);
1860 int perf_event_release_kernel(struct perf_event
*event
)
1862 struct perf_event_context
*ctx
= event
->ctx
;
1864 WARN_ON_ONCE(ctx
->parent_ctx
);
1865 mutex_lock(&ctx
->mutex
);
1866 perf_event_remove_from_context(event
);
1867 mutex_unlock(&ctx
->mutex
);
1869 mutex_lock(&event
->owner
->perf_event_mutex
);
1870 list_del_init(&event
->owner_entry
);
1871 mutex_unlock(&event
->owner
->perf_event_mutex
);
1872 put_task_struct(event
->owner
);
1878 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
1881 * Called when the last reference to the file is gone.
1883 static int perf_release(struct inode
*inode
, struct file
*file
)
1885 struct perf_event
*event
= file
->private_data
;
1887 file
->private_data
= NULL
;
1889 return perf_event_release_kernel(event
);
1892 static int perf_event_read_size(struct perf_event
*event
)
1894 int entry
= sizeof(u64
); /* value */
1898 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1899 size
+= sizeof(u64
);
1901 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1902 size
+= sizeof(u64
);
1904 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1905 entry
+= sizeof(u64
);
1907 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1908 nr
+= event
->group_leader
->nr_siblings
;
1909 size
+= sizeof(u64
);
1917 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
1919 struct perf_event
*child
;
1925 mutex_lock(&event
->child_mutex
);
1926 total
+= perf_event_read(event
);
1927 *enabled
+= event
->total_time_enabled
+
1928 atomic64_read(&event
->child_total_time_enabled
);
1929 *running
+= event
->total_time_running
+
1930 atomic64_read(&event
->child_total_time_running
);
1932 list_for_each_entry(child
, &event
->child_list
, child_list
) {
1933 total
+= perf_event_read(child
);
1934 *enabled
+= child
->total_time_enabled
;
1935 *running
+= child
->total_time_running
;
1937 mutex_unlock(&event
->child_mutex
);
1941 EXPORT_SYMBOL_GPL(perf_event_read_value
);
1943 static int perf_event_read_group(struct perf_event
*event
,
1944 u64 read_format
, char __user
*buf
)
1946 struct perf_event
*leader
= event
->group_leader
, *sub
;
1947 int n
= 0, size
= 0, ret
= -EFAULT
;
1948 struct perf_event_context
*ctx
= leader
->ctx
;
1950 u64 count
, enabled
, running
;
1952 mutex_lock(&ctx
->mutex
);
1953 count
= perf_event_read_value(leader
, &enabled
, &running
);
1955 values
[n
++] = 1 + leader
->nr_siblings
;
1956 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1957 values
[n
++] = enabled
;
1958 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1959 values
[n
++] = running
;
1960 values
[n
++] = count
;
1961 if (read_format
& PERF_FORMAT_ID
)
1962 values
[n
++] = primary_event_id(leader
);
1964 size
= n
* sizeof(u64
);
1966 if (copy_to_user(buf
, values
, size
))
1971 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
1974 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
1975 if (read_format
& PERF_FORMAT_ID
)
1976 values
[n
++] = primary_event_id(sub
);
1978 size
= n
* sizeof(u64
);
1980 if (copy_to_user(buf
+ ret
, values
, size
)) {
1988 mutex_unlock(&ctx
->mutex
);
1993 static int perf_event_read_one(struct perf_event
*event
,
1994 u64 read_format
, char __user
*buf
)
1996 u64 enabled
, running
;
2000 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
2001 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2002 values
[n
++] = enabled
;
2003 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2004 values
[n
++] = running
;
2005 if (read_format
& PERF_FORMAT_ID
)
2006 values
[n
++] = primary_event_id(event
);
2008 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2011 return n
* sizeof(u64
);
2015 * Read the performance event - simple non blocking version for now
2018 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2020 u64 read_format
= event
->attr
.read_format
;
2024 * Return end-of-file for a read on a event that is in
2025 * error state (i.e. because it was pinned but it couldn't be
2026 * scheduled on to the CPU at some point).
2028 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2031 if (count
< perf_event_read_size(event
))
2034 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2035 if (read_format
& PERF_FORMAT_GROUP
)
2036 ret
= perf_event_read_group(event
, read_format
, buf
);
2038 ret
= perf_event_read_one(event
, read_format
, buf
);
2044 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2046 struct perf_event
*event
= file
->private_data
;
2048 return perf_read_hw(event
, buf
, count
);
2051 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2053 struct perf_event
*event
= file
->private_data
;
2054 struct perf_mmap_data
*data
;
2055 unsigned int events
= POLL_HUP
;
2058 data
= rcu_dereference(event
->data
);
2060 events
= atomic_xchg(&data
->poll
, 0);
2063 poll_wait(file
, &event
->waitq
, wait
);
2068 static void perf_event_reset(struct perf_event
*event
)
2070 (void)perf_event_read(event
);
2071 atomic64_set(&event
->count
, 0);
2072 perf_event_update_userpage(event
);
2076 * Holding the top-level event's child_mutex means that any
2077 * descendant process that has inherited this event will block
2078 * in sync_child_event if it goes to exit, thus satisfying the
2079 * task existence requirements of perf_event_enable/disable.
2081 static void perf_event_for_each_child(struct perf_event
*event
,
2082 void (*func
)(struct perf_event
*))
2084 struct perf_event
*child
;
2086 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2087 mutex_lock(&event
->child_mutex
);
2089 list_for_each_entry(child
, &event
->child_list
, child_list
)
2091 mutex_unlock(&event
->child_mutex
);
2094 static void perf_event_for_each(struct perf_event
*event
,
2095 void (*func
)(struct perf_event
*))
2097 struct perf_event_context
*ctx
= event
->ctx
;
2098 struct perf_event
*sibling
;
2100 WARN_ON_ONCE(ctx
->parent_ctx
);
2101 mutex_lock(&ctx
->mutex
);
2102 event
= event
->group_leader
;
2104 perf_event_for_each_child(event
, func
);
2106 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
2107 perf_event_for_each_child(event
, func
);
2108 mutex_unlock(&ctx
->mutex
);
2111 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
2113 struct perf_event_context
*ctx
= event
->ctx
;
2118 if (!event
->attr
.sample_period
)
2121 size
= copy_from_user(&value
, arg
, sizeof(value
));
2122 if (size
!= sizeof(value
))
2128 raw_spin_lock_irq(&ctx
->lock
);
2129 if (event
->attr
.freq
) {
2130 if (value
> sysctl_perf_event_sample_rate
) {
2135 event
->attr
.sample_freq
= value
;
2137 event
->attr
.sample_period
= value
;
2138 event
->hw
.sample_period
= value
;
2141 raw_spin_unlock_irq(&ctx
->lock
);
2146 static int perf_event_set_output(struct perf_event
*event
, int output_fd
);
2147 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
2149 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2151 struct perf_event
*event
= file
->private_data
;
2152 void (*func
)(struct perf_event
*);
2156 case PERF_EVENT_IOC_ENABLE
:
2157 func
= perf_event_enable
;
2159 case PERF_EVENT_IOC_DISABLE
:
2160 func
= perf_event_disable
;
2162 case PERF_EVENT_IOC_RESET
:
2163 func
= perf_event_reset
;
2166 case PERF_EVENT_IOC_REFRESH
:
2167 return perf_event_refresh(event
, arg
);
2169 case PERF_EVENT_IOC_PERIOD
:
2170 return perf_event_period(event
, (u64 __user
*)arg
);
2172 case PERF_EVENT_IOC_SET_OUTPUT
:
2173 return perf_event_set_output(event
, arg
);
2175 case PERF_EVENT_IOC_SET_FILTER
:
2176 return perf_event_set_filter(event
, (void __user
*)arg
);
2182 if (flags
& PERF_IOC_FLAG_GROUP
)
2183 perf_event_for_each(event
, func
);
2185 perf_event_for_each_child(event
, func
);
2190 int perf_event_task_enable(void)
2192 struct perf_event
*event
;
2194 mutex_lock(¤t
->perf_event_mutex
);
2195 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2196 perf_event_for_each_child(event
, perf_event_enable
);
2197 mutex_unlock(¤t
->perf_event_mutex
);
2202 int perf_event_task_disable(void)
2204 struct perf_event
*event
;
2206 mutex_lock(¤t
->perf_event_mutex
);
2207 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2208 perf_event_for_each_child(event
, perf_event_disable
);
2209 mutex_unlock(¤t
->perf_event_mutex
);
2214 #ifndef PERF_EVENT_INDEX_OFFSET
2215 # define PERF_EVENT_INDEX_OFFSET 0
2218 static int perf_event_index(struct perf_event
*event
)
2220 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2223 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
2227 * Callers need to ensure there can be no nesting of this function, otherwise
2228 * the seqlock logic goes bad. We can not serialize this because the arch
2229 * code calls this from NMI context.
2231 void perf_event_update_userpage(struct perf_event
*event
)
2233 struct perf_event_mmap_page
*userpg
;
2234 struct perf_mmap_data
*data
;
2237 data
= rcu_dereference(event
->data
);
2241 userpg
= data
->user_page
;
2244 * Disable preemption so as to not let the corresponding user-space
2245 * spin too long if we get preempted.
2250 userpg
->index
= perf_event_index(event
);
2251 userpg
->offset
= atomic64_read(&event
->count
);
2252 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2253 userpg
->offset
-= atomic64_read(&event
->hw
.prev_count
);
2255 userpg
->time_enabled
= event
->total_time_enabled
+
2256 atomic64_read(&event
->child_total_time_enabled
);
2258 userpg
->time_running
= event
->total_time_running
+
2259 atomic64_read(&event
->child_total_time_running
);
2268 static unsigned long perf_data_size(struct perf_mmap_data
*data
)
2270 return data
->nr_pages
<< (PAGE_SHIFT
+ data
->data_order
);
2273 #ifndef CONFIG_PERF_USE_VMALLOC
2276 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
2279 static struct page
*
2280 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2282 if (pgoff
> data
->nr_pages
)
2286 return virt_to_page(data
->user_page
);
2288 return virt_to_page(data
->data_pages
[pgoff
- 1]);
2291 static struct perf_mmap_data
*
2292 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2294 struct perf_mmap_data
*data
;
2298 WARN_ON(atomic_read(&event
->mmap_count
));
2300 size
= sizeof(struct perf_mmap_data
);
2301 size
+= nr_pages
* sizeof(void *);
2303 data
= kzalloc(size
, GFP_KERNEL
);
2307 data
->user_page
= (void *)get_zeroed_page(GFP_KERNEL
);
2308 if (!data
->user_page
)
2309 goto fail_user_page
;
2311 for (i
= 0; i
< nr_pages
; i
++) {
2312 data
->data_pages
[i
] = (void *)get_zeroed_page(GFP_KERNEL
);
2313 if (!data
->data_pages
[i
])
2314 goto fail_data_pages
;
2317 data
->data_order
= 0;
2318 data
->nr_pages
= nr_pages
;
2323 for (i
--; i
>= 0; i
--)
2324 free_page((unsigned long)data
->data_pages
[i
]);
2326 free_page((unsigned long)data
->user_page
);
2335 static void perf_mmap_free_page(unsigned long addr
)
2337 struct page
*page
= virt_to_page((void *)addr
);
2339 page
->mapping
= NULL
;
2343 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2347 perf_mmap_free_page((unsigned long)data
->user_page
);
2348 for (i
= 0; i
< data
->nr_pages
; i
++)
2349 perf_mmap_free_page((unsigned long)data
->data_pages
[i
]);
2356 * Back perf_mmap() with vmalloc memory.
2358 * Required for architectures that have d-cache aliasing issues.
2361 static struct page
*
2362 perf_mmap_to_page(struct perf_mmap_data
*data
, unsigned long pgoff
)
2364 if (pgoff
> (1UL << data
->data_order
))
2367 return vmalloc_to_page((void *)data
->user_page
+ pgoff
* PAGE_SIZE
);
2370 static void perf_mmap_unmark_page(void *addr
)
2372 struct page
*page
= vmalloc_to_page(addr
);
2374 page
->mapping
= NULL
;
2377 static void perf_mmap_data_free_work(struct work_struct
*work
)
2379 struct perf_mmap_data
*data
;
2383 data
= container_of(work
, struct perf_mmap_data
, work
);
2384 nr
= 1 << data
->data_order
;
2386 base
= data
->user_page
;
2387 for (i
= 0; i
< nr
+ 1; i
++)
2388 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
2394 static void perf_mmap_data_free(struct perf_mmap_data
*data
)
2396 schedule_work(&data
->work
);
2399 static struct perf_mmap_data
*
2400 perf_mmap_data_alloc(struct perf_event
*event
, int nr_pages
)
2402 struct perf_mmap_data
*data
;
2406 WARN_ON(atomic_read(&event
->mmap_count
));
2408 size
= sizeof(struct perf_mmap_data
);
2409 size
+= sizeof(void *);
2411 data
= kzalloc(size
, GFP_KERNEL
);
2415 INIT_WORK(&data
->work
, perf_mmap_data_free_work
);
2417 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
2421 data
->user_page
= all_buf
;
2422 data
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
2423 data
->data_order
= ilog2(nr_pages
);
2437 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
2439 struct perf_event
*event
= vma
->vm_file
->private_data
;
2440 struct perf_mmap_data
*data
;
2441 int ret
= VM_FAULT_SIGBUS
;
2443 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
2444 if (vmf
->pgoff
== 0)
2450 data
= rcu_dereference(event
->data
);
2454 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
2457 vmf
->page
= perf_mmap_to_page(data
, vmf
->pgoff
);
2461 get_page(vmf
->page
);
2462 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
2463 vmf
->page
->index
= vmf
->pgoff
;
2473 perf_mmap_data_init(struct perf_event
*event
, struct perf_mmap_data
*data
)
2475 long max_size
= perf_data_size(data
);
2477 atomic_set(&data
->lock
, -1);
2479 if (event
->attr
.watermark
) {
2480 data
->watermark
= min_t(long, max_size
,
2481 event
->attr
.wakeup_watermark
);
2484 if (!data
->watermark
)
2485 data
->watermark
= max_size
/ 2;
2488 rcu_assign_pointer(event
->data
, data
);
2491 static void perf_mmap_data_free_rcu(struct rcu_head
*rcu_head
)
2493 struct perf_mmap_data
*data
;
2495 data
= container_of(rcu_head
, struct perf_mmap_data
, rcu_head
);
2496 perf_mmap_data_free(data
);
2499 static void perf_mmap_data_release(struct perf_event
*event
)
2501 struct perf_mmap_data
*data
= event
->data
;
2503 WARN_ON(atomic_read(&event
->mmap_count
));
2505 rcu_assign_pointer(event
->data
, NULL
);
2506 call_rcu(&data
->rcu_head
, perf_mmap_data_free_rcu
);
2509 static void perf_mmap_open(struct vm_area_struct
*vma
)
2511 struct perf_event
*event
= vma
->vm_file
->private_data
;
2513 atomic_inc(&event
->mmap_count
);
2516 static void perf_mmap_close(struct vm_area_struct
*vma
)
2518 struct perf_event
*event
= vma
->vm_file
->private_data
;
2520 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2521 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
2522 unsigned long size
= perf_data_size(event
->data
);
2523 struct user_struct
*user
= current_user();
2525 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
2526 vma
->vm_mm
->locked_vm
-= event
->data
->nr_locked
;
2527 perf_mmap_data_release(event
);
2528 mutex_unlock(&event
->mmap_mutex
);
2532 static const struct vm_operations_struct perf_mmap_vmops
= {
2533 .open
= perf_mmap_open
,
2534 .close
= perf_mmap_close
,
2535 .fault
= perf_mmap_fault
,
2536 .page_mkwrite
= perf_mmap_fault
,
2539 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
2541 struct perf_event
*event
= file
->private_data
;
2542 unsigned long user_locked
, user_lock_limit
;
2543 struct user_struct
*user
= current_user();
2544 unsigned long locked
, lock_limit
;
2545 struct perf_mmap_data
*data
;
2546 unsigned long vma_size
;
2547 unsigned long nr_pages
;
2548 long user_extra
, extra
;
2551 if (!(vma
->vm_flags
& VM_SHARED
))
2554 vma_size
= vma
->vm_end
- vma
->vm_start
;
2555 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
2558 * If we have data pages ensure they're a power-of-two number, so we
2559 * can do bitmasks instead of modulo.
2561 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
2564 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
2567 if (vma
->vm_pgoff
!= 0)
2570 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2571 mutex_lock(&event
->mmap_mutex
);
2572 if (event
->output
) {
2577 if (atomic_inc_not_zero(&event
->mmap_count
)) {
2578 if (nr_pages
!= event
->data
->nr_pages
)
2583 user_extra
= nr_pages
+ 1;
2584 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
2587 * Increase the limit linearly with more CPUs:
2589 user_lock_limit
*= num_online_cpus();
2591 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
2594 if (user_locked
> user_lock_limit
)
2595 extra
= user_locked
- user_lock_limit
;
2597 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
2598 lock_limit
>>= PAGE_SHIFT
;
2599 locked
= vma
->vm_mm
->locked_vm
+ extra
;
2601 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
2602 !capable(CAP_IPC_LOCK
)) {
2607 WARN_ON(event
->data
);
2609 data
= perf_mmap_data_alloc(event
, nr_pages
);
2615 perf_mmap_data_init(event
, data
);
2617 atomic_set(&event
->mmap_count
, 1);
2618 atomic_long_add(user_extra
, &user
->locked_vm
);
2619 vma
->vm_mm
->locked_vm
+= extra
;
2620 event
->data
->nr_locked
= extra
;
2621 if (vma
->vm_flags
& VM_WRITE
)
2622 event
->data
->writable
= 1;
2625 mutex_unlock(&event
->mmap_mutex
);
2627 vma
->vm_flags
|= VM_RESERVED
;
2628 vma
->vm_ops
= &perf_mmap_vmops
;
2633 static int perf_fasync(int fd
, struct file
*filp
, int on
)
2635 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
2636 struct perf_event
*event
= filp
->private_data
;
2639 mutex_lock(&inode
->i_mutex
);
2640 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
2641 mutex_unlock(&inode
->i_mutex
);
2649 static const struct file_operations perf_fops
= {
2650 .llseek
= no_llseek
,
2651 .release
= perf_release
,
2654 .unlocked_ioctl
= perf_ioctl
,
2655 .compat_ioctl
= perf_ioctl
,
2657 .fasync
= perf_fasync
,
2663 * If there's data, ensure we set the poll() state and publish everything
2664 * to user-space before waking everybody up.
2667 void perf_event_wakeup(struct perf_event
*event
)
2669 wake_up_all(&event
->waitq
);
2671 if (event
->pending_kill
) {
2672 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
2673 event
->pending_kill
= 0;
2680 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
2682 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
2683 * single linked list and use cmpxchg() to add entries lockless.
2686 static void perf_pending_event(struct perf_pending_entry
*entry
)
2688 struct perf_event
*event
= container_of(entry
,
2689 struct perf_event
, pending
);
2691 if (event
->pending_disable
) {
2692 event
->pending_disable
= 0;
2693 __perf_event_disable(event
);
2696 if (event
->pending_wakeup
) {
2697 event
->pending_wakeup
= 0;
2698 perf_event_wakeup(event
);
2702 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
2704 static DEFINE_PER_CPU(struct perf_pending_entry
*, perf_pending_head
) = {
2708 static void perf_pending_queue(struct perf_pending_entry
*entry
,
2709 void (*func
)(struct perf_pending_entry
*))
2711 struct perf_pending_entry
**head
;
2713 if (cmpxchg(&entry
->next
, NULL
, PENDING_TAIL
) != NULL
)
2718 head
= &get_cpu_var(perf_pending_head
);
2721 entry
->next
= *head
;
2722 } while (cmpxchg(head
, entry
->next
, entry
) != entry
->next
);
2724 set_perf_event_pending();
2726 put_cpu_var(perf_pending_head
);
2729 static int __perf_pending_run(void)
2731 struct perf_pending_entry
*list
;
2734 list
= xchg(&__get_cpu_var(perf_pending_head
), PENDING_TAIL
);
2735 while (list
!= PENDING_TAIL
) {
2736 void (*func
)(struct perf_pending_entry
*);
2737 struct perf_pending_entry
*entry
= list
;
2744 * Ensure we observe the unqueue before we issue the wakeup,
2745 * so that we won't be waiting forever.
2746 * -- see perf_not_pending().
2757 static inline int perf_not_pending(struct perf_event
*event
)
2760 * If we flush on whatever cpu we run, there is a chance we don't
2764 __perf_pending_run();
2768 * Ensure we see the proper queue state before going to sleep
2769 * so that we do not miss the wakeup. -- see perf_pending_handle()
2772 return event
->pending
.next
== NULL
;
2775 static void perf_pending_sync(struct perf_event
*event
)
2777 wait_event(event
->waitq
, perf_not_pending(event
));
2780 void perf_event_do_pending(void)
2782 __perf_pending_run();
2786 * Callchain support -- arch specific
2789 __weak
struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2795 void perf_arch_fetch_caller_regs(struct pt_regs
*regs
, unsigned long ip
, int skip
)
2803 static bool perf_output_space(struct perf_mmap_data
*data
, unsigned long tail
,
2804 unsigned long offset
, unsigned long head
)
2808 if (!data
->writable
)
2811 mask
= perf_data_size(data
) - 1;
2813 offset
= (offset
- tail
) & mask
;
2814 head
= (head
- tail
) & mask
;
2816 if ((int)(head
- offset
) < 0)
2822 static void perf_output_wakeup(struct perf_output_handle
*handle
)
2824 atomic_set(&handle
->data
->poll
, POLL_IN
);
2827 handle
->event
->pending_wakeup
= 1;
2828 perf_pending_queue(&handle
->event
->pending
,
2829 perf_pending_event
);
2831 perf_event_wakeup(handle
->event
);
2835 * Curious locking construct.
2837 * We need to ensure a later event_id doesn't publish a head when a former
2838 * event_id isn't done writing. However since we need to deal with NMIs we
2839 * cannot fully serialize things.
2841 * What we do is serialize between CPUs so we only have to deal with NMI
2842 * nesting on a single CPU.
2844 * We only publish the head (and generate a wakeup) when the outer-most
2845 * event_id completes.
2847 static void perf_output_lock(struct perf_output_handle
*handle
)
2849 struct perf_mmap_data
*data
= handle
->data
;
2850 int cur
, cpu
= get_cpu();
2855 cur
= atomic_cmpxchg(&data
->lock
, -1, cpu
);
2867 static void perf_output_unlock(struct perf_output_handle
*handle
)
2869 struct perf_mmap_data
*data
= handle
->data
;
2873 data
->done_head
= data
->head
;
2875 if (!handle
->locked
)
2880 * The xchg implies a full barrier that ensures all writes are done
2881 * before we publish the new head, matched by a rmb() in userspace when
2882 * reading this position.
2884 while ((head
= atomic_long_xchg(&data
->done_head
, 0)))
2885 data
->user_page
->data_head
= head
;
2888 * NMI can happen here, which means we can miss a done_head update.
2891 cpu
= atomic_xchg(&data
->lock
, -1);
2892 WARN_ON_ONCE(cpu
!= smp_processor_id());
2895 * Therefore we have to validate we did not indeed do so.
2897 if (unlikely(atomic_long_read(&data
->done_head
))) {
2899 * Since we had it locked, we can lock it again.
2901 while (atomic_cmpxchg(&data
->lock
, -1, cpu
) != -1)
2907 if (atomic_xchg(&data
->wakeup
, 0))
2908 perf_output_wakeup(handle
);
2913 void perf_output_copy(struct perf_output_handle
*handle
,
2914 const void *buf
, unsigned int len
)
2916 unsigned int pages_mask
;
2917 unsigned long offset
;
2921 offset
= handle
->offset
;
2922 pages_mask
= handle
->data
->nr_pages
- 1;
2923 pages
= handle
->data
->data_pages
;
2926 unsigned long page_offset
;
2927 unsigned long page_size
;
2930 nr
= (offset
>> PAGE_SHIFT
) & pages_mask
;
2931 page_size
= 1UL << (handle
->data
->data_order
+ PAGE_SHIFT
);
2932 page_offset
= offset
& (page_size
- 1);
2933 size
= min_t(unsigned int, page_size
- page_offset
, len
);
2935 memcpy(pages
[nr
] + page_offset
, buf
, size
);
2942 handle
->offset
= offset
;
2945 * Check we didn't copy past our reservation window, taking the
2946 * possible unsigned int wrap into account.
2948 WARN_ON_ONCE(((long)(handle
->head
- handle
->offset
)) < 0);
2951 int perf_output_begin(struct perf_output_handle
*handle
,
2952 struct perf_event
*event
, unsigned int size
,
2953 int nmi
, int sample
)
2955 struct perf_event
*output_event
;
2956 struct perf_mmap_data
*data
;
2957 unsigned long tail
, offset
, head
;
2960 struct perf_event_header header
;
2967 * For inherited events we send all the output towards the parent.
2970 event
= event
->parent
;
2972 output_event
= rcu_dereference(event
->output
);
2974 event
= output_event
;
2976 data
= rcu_dereference(event
->data
);
2980 handle
->data
= data
;
2981 handle
->event
= event
;
2983 handle
->sample
= sample
;
2985 if (!data
->nr_pages
)
2988 have_lost
= atomic_read(&data
->lost
);
2990 size
+= sizeof(lost_event
);
2992 perf_output_lock(handle
);
2996 * Userspace could choose to issue a mb() before updating the
2997 * tail pointer. So that all reads will be completed before the
3000 tail
= ACCESS_ONCE(data
->user_page
->data_tail
);
3002 offset
= head
= atomic_long_read(&data
->head
);
3004 if (unlikely(!perf_output_space(data
, tail
, offset
, head
)))
3006 } while (atomic_long_cmpxchg(&data
->head
, offset
, head
) != offset
);
3008 handle
->offset
= offset
;
3009 handle
->head
= head
;
3011 if (head
- tail
> data
->watermark
)
3012 atomic_set(&data
->wakeup
, 1);
3015 lost_event
.header
.type
= PERF_RECORD_LOST
;
3016 lost_event
.header
.misc
= 0;
3017 lost_event
.header
.size
= sizeof(lost_event
);
3018 lost_event
.id
= event
->id
;
3019 lost_event
.lost
= atomic_xchg(&data
->lost
, 0);
3021 perf_output_put(handle
, lost_event
);
3027 atomic_inc(&data
->lost
);
3028 perf_output_unlock(handle
);
3035 void perf_output_end(struct perf_output_handle
*handle
)
3037 struct perf_event
*event
= handle
->event
;
3038 struct perf_mmap_data
*data
= handle
->data
;
3040 int wakeup_events
= event
->attr
.wakeup_events
;
3042 if (handle
->sample
&& wakeup_events
) {
3043 int events
= atomic_inc_return(&data
->events
);
3044 if (events
>= wakeup_events
) {
3045 atomic_sub(wakeup_events
, &data
->events
);
3046 atomic_set(&data
->wakeup
, 1);
3050 perf_output_unlock(handle
);
3054 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
3057 * only top level events have the pid namespace they were created in
3060 event
= event
->parent
;
3062 return task_tgid_nr_ns(p
, event
->ns
);
3065 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
3068 * only top level events have the pid namespace they were created in
3071 event
= event
->parent
;
3073 return task_pid_nr_ns(p
, event
->ns
);
3076 static void perf_output_read_one(struct perf_output_handle
*handle
,
3077 struct perf_event
*event
)
3079 u64 read_format
= event
->attr
.read_format
;
3083 values
[n
++] = atomic64_read(&event
->count
);
3084 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3085 values
[n
++] = event
->total_time_enabled
+
3086 atomic64_read(&event
->child_total_time_enabled
);
3088 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3089 values
[n
++] = event
->total_time_running
+
3090 atomic64_read(&event
->child_total_time_running
);
3092 if (read_format
& PERF_FORMAT_ID
)
3093 values
[n
++] = primary_event_id(event
);
3095 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3099 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3101 static void perf_output_read_group(struct perf_output_handle
*handle
,
3102 struct perf_event
*event
)
3104 struct perf_event
*leader
= event
->group_leader
, *sub
;
3105 u64 read_format
= event
->attr
.read_format
;
3109 values
[n
++] = 1 + leader
->nr_siblings
;
3111 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3112 values
[n
++] = leader
->total_time_enabled
;
3114 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3115 values
[n
++] = leader
->total_time_running
;
3117 if (leader
!= event
)
3118 leader
->pmu
->read(leader
);
3120 values
[n
++] = atomic64_read(&leader
->count
);
3121 if (read_format
& PERF_FORMAT_ID
)
3122 values
[n
++] = primary_event_id(leader
);
3124 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3126 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3130 sub
->pmu
->read(sub
);
3132 values
[n
++] = atomic64_read(&sub
->count
);
3133 if (read_format
& PERF_FORMAT_ID
)
3134 values
[n
++] = primary_event_id(sub
);
3136 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3140 static void perf_output_read(struct perf_output_handle
*handle
,
3141 struct perf_event
*event
)
3143 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3144 perf_output_read_group(handle
, event
);
3146 perf_output_read_one(handle
, event
);
3149 void perf_output_sample(struct perf_output_handle
*handle
,
3150 struct perf_event_header
*header
,
3151 struct perf_sample_data
*data
,
3152 struct perf_event
*event
)
3154 u64 sample_type
= data
->type
;
3156 perf_output_put(handle
, *header
);
3158 if (sample_type
& PERF_SAMPLE_IP
)
3159 perf_output_put(handle
, data
->ip
);
3161 if (sample_type
& PERF_SAMPLE_TID
)
3162 perf_output_put(handle
, data
->tid_entry
);
3164 if (sample_type
& PERF_SAMPLE_TIME
)
3165 perf_output_put(handle
, data
->time
);
3167 if (sample_type
& PERF_SAMPLE_ADDR
)
3168 perf_output_put(handle
, data
->addr
);
3170 if (sample_type
& PERF_SAMPLE_ID
)
3171 perf_output_put(handle
, data
->id
);
3173 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3174 perf_output_put(handle
, data
->stream_id
);
3176 if (sample_type
& PERF_SAMPLE_CPU
)
3177 perf_output_put(handle
, data
->cpu_entry
);
3179 if (sample_type
& PERF_SAMPLE_PERIOD
)
3180 perf_output_put(handle
, data
->period
);
3182 if (sample_type
& PERF_SAMPLE_READ
)
3183 perf_output_read(handle
, event
);
3185 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3186 if (data
->callchain
) {
3189 if (data
->callchain
)
3190 size
+= data
->callchain
->nr
;
3192 size
*= sizeof(u64
);
3194 perf_output_copy(handle
, data
->callchain
, size
);
3197 perf_output_put(handle
, nr
);
3201 if (sample_type
& PERF_SAMPLE_RAW
) {
3203 perf_output_put(handle
, data
->raw
->size
);
3204 perf_output_copy(handle
, data
->raw
->data
,
3211 .size
= sizeof(u32
),
3214 perf_output_put(handle
, raw
);
3219 void perf_prepare_sample(struct perf_event_header
*header
,
3220 struct perf_sample_data
*data
,
3221 struct perf_event
*event
,
3222 struct pt_regs
*regs
)
3224 u64 sample_type
= event
->attr
.sample_type
;
3226 data
->type
= sample_type
;
3228 header
->type
= PERF_RECORD_SAMPLE
;
3229 header
->size
= sizeof(*header
);
3232 header
->misc
|= perf_misc_flags(regs
);
3234 if (sample_type
& PERF_SAMPLE_IP
) {
3235 data
->ip
= perf_instruction_pointer(regs
);
3237 header
->size
+= sizeof(data
->ip
);
3240 if (sample_type
& PERF_SAMPLE_TID
) {
3241 /* namespace issues */
3242 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3243 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3245 header
->size
+= sizeof(data
->tid_entry
);
3248 if (sample_type
& PERF_SAMPLE_TIME
) {
3249 data
->time
= perf_clock();
3251 header
->size
+= sizeof(data
->time
);
3254 if (sample_type
& PERF_SAMPLE_ADDR
)
3255 header
->size
+= sizeof(data
->addr
);
3257 if (sample_type
& PERF_SAMPLE_ID
) {
3258 data
->id
= primary_event_id(event
);
3260 header
->size
+= sizeof(data
->id
);
3263 if (sample_type
& PERF_SAMPLE_STREAM_ID
) {
3264 data
->stream_id
= event
->id
;
3266 header
->size
+= sizeof(data
->stream_id
);
3269 if (sample_type
& PERF_SAMPLE_CPU
) {
3270 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3271 data
->cpu_entry
.reserved
= 0;
3273 header
->size
+= sizeof(data
->cpu_entry
);
3276 if (sample_type
& PERF_SAMPLE_PERIOD
)
3277 header
->size
+= sizeof(data
->period
);
3279 if (sample_type
& PERF_SAMPLE_READ
)
3280 header
->size
+= perf_event_read_size(event
);
3282 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3285 data
->callchain
= perf_callchain(regs
);
3287 if (data
->callchain
)
3288 size
+= data
->callchain
->nr
;
3290 header
->size
+= size
* sizeof(u64
);
3293 if (sample_type
& PERF_SAMPLE_RAW
) {
3294 int size
= sizeof(u32
);
3297 size
+= data
->raw
->size
;
3299 size
+= sizeof(u32
);
3301 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3302 header
->size
+= size
;
3306 static void perf_event_output(struct perf_event
*event
, int nmi
,
3307 struct perf_sample_data
*data
,
3308 struct pt_regs
*regs
)
3310 struct perf_output_handle handle
;
3311 struct perf_event_header header
;
3313 perf_prepare_sample(&header
, data
, event
, regs
);
3315 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
3318 perf_output_sample(&handle
, &header
, data
, event
);
3320 perf_output_end(&handle
);
3327 struct perf_read_event
{
3328 struct perf_event_header header
;
3335 perf_event_read_event(struct perf_event
*event
,
3336 struct task_struct
*task
)
3338 struct perf_output_handle handle
;
3339 struct perf_read_event read_event
= {
3341 .type
= PERF_RECORD_READ
,
3343 .size
= sizeof(read_event
) + perf_event_read_size(event
),
3345 .pid
= perf_event_pid(event
, task
),
3346 .tid
= perf_event_tid(event
, task
),
3350 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
3354 perf_output_put(&handle
, read_event
);
3355 perf_output_read(&handle
, event
);
3357 perf_output_end(&handle
);
3361 * task tracking -- fork/exit
3363 * enabled by: attr.comm | attr.mmap | attr.task
3366 struct perf_task_event
{
3367 struct task_struct
*task
;
3368 struct perf_event_context
*task_ctx
;
3371 struct perf_event_header header
;
3381 static void perf_event_task_output(struct perf_event
*event
,
3382 struct perf_task_event
*task_event
)
3384 struct perf_output_handle handle
;
3385 struct task_struct
*task
= task_event
->task
;
3386 unsigned long flags
;
3390 * If this CPU attempts to acquire an rq lock held by a CPU spinning
3391 * in perf_output_lock() from interrupt context, it's game over.
3393 local_irq_save(flags
);
3395 size
= task_event
->event_id
.header
.size
;
3396 ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3399 local_irq_restore(flags
);
3403 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
3404 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
3406 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
3407 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
3409 perf_output_put(&handle
, task_event
->event_id
);
3411 perf_output_end(&handle
);
3412 local_irq_restore(flags
);
3415 static int perf_event_task_match(struct perf_event
*event
)
3417 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3420 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3423 if (event
->attr
.comm
|| event
->attr
.mmap
|| event
->attr
.task
)
3429 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
3430 struct perf_task_event
*task_event
)
3432 struct perf_event
*event
;
3434 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3435 if (perf_event_task_match(event
))
3436 perf_event_task_output(event
, task_event
);
3440 static void perf_event_task_event(struct perf_task_event
*task_event
)
3442 struct perf_cpu_context
*cpuctx
;
3443 struct perf_event_context
*ctx
= task_event
->task_ctx
;
3446 cpuctx
= &get_cpu_var(perf_cpu_context
);
3447 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
3449 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3451 perf_event_task_ctx(ctx
, task_event
);
3452 put_cpu_var(perf_cpu_context
);
3456 static void perf_event_task(struct task_struct
*task
,
3457 struct perf_event_context
*task_ctx
,
3460 struct perf_task_event task_event
;
3462 if (!atomic_read(&nr_comm_events
) &&
3463 !atomic_read(&nr_mmap_events
) &&
3464 !atomic_read(&nr_task_events
))
3467 task_event
= (struct perf_task_event
){
3469 .task_ctx
= task_ctx
,
3472 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
3474 .size
= sizeof(task_event
.event_id
),
3480 .time
= perf_clock(),
3484 perf_event_task_event(&task_event
);
3487 void perf_event_fork(struct task_struct
*task
)
3489 perf_event_task(task
, NULL
, 1);
3496 struct perf_comm_event
{
3497 struct task_struct
*task
;
3502 struct perf_event_header header
;
3509 static void perf_event_comm_output(struct perf_event
*event
,
3510 struct perf_comm_event
*comm_event
)
3512 struct perf_output_handle handle
;
3513 int size
= comm_event
->event_id
.header
.size
;
3514 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3519 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
3520 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
3522 perf_output_put(&handle
, comm_event
->event_id
);
3523 perf_output_copy(&handle
, comm_event
->comm
,
3524 comm_event
->comm_size
);
3525 perf_output_end(&handle
);
3528 static int perf_event_comm_match(struct perf_event
*event
)
3530 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3533 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3536 if (event
->attr
.comm
)
3542 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
3543 struct perf_comm_event
*comm_event
)
3545 struct perf_event
*event
;
3547 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3548 if (perf_event_comm_match(event
))
3549 perf_event_comm_output(event
, comm_event
);
3553 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
3555 struct perf_cpu_context
*cpuctx
;
3556 struct perf_event_context
*ctx
;
3558 char comm
[TASK_COMM_LEN
];
3560 memset(comm
, 0, sizeof(comm
));
3561 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
3562 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
3564 comm_event
->comm
= comm
;
3565 comm_event
->comm_size
= size
;
3567 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
3570 cpuctx
= &get_cpu_var(perf_cpu_context
);
3571 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
3572 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3574 perf_event_comm_ctx(ctx
, comm_event
);
3575 put_cpu_var(perf_cpu_context
);
3579 void perf_event_comm(struct task_struct
*task
)
3581 struct perf_comm_event comm_event
;
3583 if (task
->perf_event_ctxp
)
3584 perf_event_enable_on_exec(task
);
3586 if (!atomic_read(&nr_comm_events
))
3589 comm_event
= (struct perf_comm_event
){
3595 .type
= PERF_RECORD_COMM
,
3604 perf_event_comm_event(&comm_event
);
3611 struct perf_mmap_event
{
3612 struct vm_area_struct
*vma
;
3614 const char *file_name
;
3618 struct perf_event_header header
;
3628 static void perf_event_mmap_output(struct perf_event
*event
,
3629 struct perf_mmap_event
*mmap_event
)
3631 struct perf_output_handle handle
;
3632 int size
= mmap_event
->event_id
.header
.size
;
3633 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3638 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
3639 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
3641 perf_output_put(&handle
, mmap_event
->event_id
);
3642 perf_output_copy(&handle
, mmap_event
->file_name
,
3643 mmap_event
->file_size
);
3644 perf_output_end(&handle
);
3647 static int perf_event_mmap_match(struct perf_event
*event
,
3648 struct perf_mmap_event
*mmap_event
)
3650 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3653 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3656 if (event
->attr
.mmap
)
3662 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
3663 struct perf_mmap_event
*mmap_event
)
3665 struct perf_event
*event
;
3667 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3668 if (perf_event_mmap_match(event
, mmap_event
))
3669 perf_event_mmap_output(event
, mmap_event
);
3673 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
3675 struct perf_cpu_context
*cpuctx
;
3676 struct perf_event_context
*ctx
;
3677 struct vm_area_struct
*vma
= mmap_event
->vma
;
3678 struct file
*file
= vma
->vm_file
;
3684 memset(tmp
, 0, sizeof(tmp
));
3688 * d_path works from the end of the buffer backwards, so we
3689 * need to add enough zero bytes after the string to handle
3690 * the 64bit alignment we do later.
3692 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
3694 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
3697 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
3699 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
3703 if (arch_vma_name(mmap_event
->vma
)) {
3704 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
3710 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
3714 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
3719 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
3721 mmap_event
->file_name
= name
;
3722 mmap_event
->file_size
= size
;
3724 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
3727 cpuctx
= &get_cpu_var(perf_cpu_context
);
3728 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
);
3729 ctx
= rcu_dereference(current
->perf_event_ctxp
);
3731 perf_event_mmap_ctx(ctx
, mmap_event
);
3732 put_cpu_var(perf_cpu_context
);
3738 void __perf_event_mmap(struct vm_area_struct
*vma
)
3740 struct perf_mmap_event mmap_event
;
3742 if (!atomic_read(&nr_mmap_events
))
3745 mmap_event
= (struct perf_mmap_event
){
3751 .type
= PERF_RECORD_MMAP
,
3757 .start
= vma
->vm_start
,
3758 .len
= vma
->vm_end
- vma
->vm_start
,
3759 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
3763 perf_event_mmap_event(&mmap_event
);
3767 * IRQ throttle logging
3770 static void perf_log_throttle(struct perf_event
*event
, int enable
)
3772 struct perf_output_handle handle
;
3776 struct perf_event_header header
;
3780 } throttle_event
= {
3782 .type
= PERF_RECORD_THROTTLE
,
3784 .size
= sizeof(throttle_event
),
3786 .time
= perf_clock(),
3787 .id
= primary_event_id(event
),
3788 .stream_id
= event
->id
,
3792 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
3794 ret
= perf_output_begin(&handle
, event
, sizeof(throttle_event
), 1, 0);
3798 perf_output_put(&handle
, throttle_event
);
3799 perf_output_end(&handle
);
3803 * Generic event overflow handling, sampling.
3806 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
3807 int throttle
, struct perf_sample_data
*data
,
3808 struct pt_regs
*regs
)
3810 int events
= atomic_read(&event
->event_limit
);
3811 struct hw_perf_event
*hwc
= &event
->hw
;
3814 throttle
= (throttle
&& event
->pmu
->unthrottle
!= NULL
);
3819 if (hwc
->interrupts
!= MAX_INTERRUPTS
) {
3821 if (HZ
* hwc
->interrupts
>
3822 (u64
)sysctl_perf_event_sample_rate
) {
3823 hwc
->interrupts
= MAX_INTERRUPTS
;
3824 perf_log_throttle(event
, 0);
3829 * Keep re-disabling events even though on the previous
3830 * pass we disabled it - just in case we raced with a
3831 * sched-in and the event got enabled again:
3837 if (event
->attr
.freq
) {
3838 u64 now
= perf_clock();
3839 s64 delta
= now
- hwc
->freq_time_stamp
;
3841 hwc
->freq_time_stamp
= now
;
3843 if (delta
> 0 && delta
< 2*TICK_NSEC
)
3844 perf_adjust_period(event
, delta
, hwc
->last_period
);
3848 * XXX event_limit might not quite work as expected on inherited
3852 event
->pending_kill
= POLL_IN
;
3853 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
3855 event
->pending_kill
= POLL_HUP
;
3857 event
->pending_disable
= 1;
3858 perf_pending_queue(&event
->pending
,
3859 perf_pending_event
);
3861 perf_event_disable(event
);
3864 if (event
->overflow_handler
)
3865 event
->overflow_handler(event
, nmi
, data
, regs
);
3867 perf_event_output(event
, nmi
, data
, regs
);
3872 int perf_event_overflow(struct perf_event
*event
, int nmi
,
3873 struct perf_sample_data
*data
,
3874 struct pt_regs
*regs
)
3876 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
3880 * Generic software event infrastructure
3884 * We directly increment event->count and keep a second value in
3885 * event->hw.period_left to count intervals. This period event
3886 * is kept in the range [-sample_period, 0] so that we can use the
3890 static u64
perf_swevent_set_period(struct perf_event
*event
)
3892 struct hw_perf_event
*hwc
= &event
->hw
;
3893 u64 period
= hwc
->last_period
;
3897 hwc
->last_period
= hwc
->sample_period
;
3900 old
= val
= atomic64_read(&hwc
->period_left
);
3904 nr
= div64_u64(period
+ val
, period
);
3905 offset
= nr
* period
;
3907 if (atomic64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
3913 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
3914 int nmi
, struct perf_sample_data
*data
,
3915 struct pt_regs
*regs
)
3917 struct hw_perf_event
*hwc
= &event
->hw
;
3920 data
->period
= event
->hw
.last_period
;
3922 overflow
= perf_swevent_set_period(event
);
3924 if (hwc
->interrupts
== MAX_INTERRUPTS
)
3927 for (; overflow
; overflow
--) {
3928 if (__perf_event_overflow(event
, nmi
, throttle
,
3931 * We inhibit the overflow from happening when
3932 * hwc->interrupts == MAX_INTERRUPTS.
3940 static void perf_swevent_unthrottle(struct perf_event
*event
)
3943 * Nothing to do, we already reset hwc->interrupts.
3947 static void perf_swevent_add(struct perf_event
*event
, u64 nr
,
3948 int nmi
, struct perf_sample_data
*data
,
3949 struct pt_regs
*regs
)
3951 struct hw_perf_event
*hwc
= &event
->hw
;
3953 atomic64_add(nr
, &event
->count
);
3958 if (!hwc
->sample_period
)
3961 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
3962 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
3964 if (atomic64_add_negative(nr
, &hwc
->period_left
))
3967 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
3970 static int perf_tp_event_match(struct perf_event
*event
,
3971 struct perf_sample_data
*data
);
3973 static int perf_exclude_event(struct perf_event
*event
,
3974 struct pt_regs
*regs
)
3977 if (event
->attr
.exclude_user
&& user_mode(regs
))
3980 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
3987 static int perf_swevent_match(struct perf_event
*event
,
3988 enum perf_type_id type
,
3990 struct perf_sample_data
*data
,
3991 struct pt_regs
*regs
)
3993 if (event
->attr
.type
!= type
)
3996 if (event
->attr
.config
!= event_id
)
3999 if (perf_exclude_event(event
, regs
))
4002 if (event
->attr
.type
== PERF_TYPE_TRACEPOINT
&&
4003 !perf_tp_event_match(event
, data
))
4009 static inline u64
swevent_hash(u64 type
, u32 event_id
)
4011 u64 val
= event_id
| (type
<< 32);
4013 return hash_64(val
, SWEVENT_HLIST_BITS
);
4016 static struct hlist_head
*
4017 find_swevent_head(struct perf_cpu_context
*ctx
, u64 type
, u32 event_id
)
4020 struct swevent_hlist
*hlist
;
4022 hash
= swevent_hash(type
, event_id
);
4024 hlist
= rcu_dereference(ctx
->swevent_hlist
);
4028 return &hlist
->heads
[hash
];
4031 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4033 struct perf_sample_data
*data
,
4034 struct pt_regs
*regs
)
4036 struct perf_cpu_context
*cpuctx
;
4037 struct perf_event
*event
;
4038 struct hlist_node
*node
;
4039 struct hlist_head
*head
;
4041 cpuctx
= &__get_cpu_var(perf_cpu_context
);
4045 head
= find_swevent_head(cpuctx
, type
, event_id
);
4050 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4051 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4052 perf_swevent_add(event
, nr
, nmi
, data
, regs
);
4058 int perf_swevent_get_recursion_context(void)
4060 struct perf_cpu_context
*cpuctx
= &get_cpu_var(perf_cpu_context
);
4067 else if (in_softirq())
4072 if (cpuctx
->recursion
[rctx
]) {
4073 put_cpu_var(perf_cpu_context
);
4077 cpuctx
->recursion
[rctx
]++;
4082 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4084 void perf_swevent_put_recursion_context(int rctx
)
4086 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
4088 cpuctx
->recursion
[rctx
]--;
4089 put_cpu_var(perf_cpu_context
);
4091 EXPORT_SYMBOL_GPL(perf_swevent_put_recursion_context
);
4094 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
4095 struct pt_regs
*regs
, u64 addr
)
4097 struct perf_sample_data data
;
4100 rctx
= perf_swevent_get_recursion_context();
4104 perf_sample_data_init(&data
, addr
);
4106 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
4108 perf_swevent_put_recursion_context(rctx
);
4111 static void perf_swevent_read(struct perf_event
*event
)
4115 static int perf_swevent_enable(struct perf_event
*event
)
4117 struct hw_perf_event
*hwc
= &event
->hw
;
4118 struct perf_cpu_context
*cpuctx
;
4119 struct hlist_head
*head
;
4121 cpuctx
= &__get_cpu_var(perf_cpu_context
);
4123 if (hwc
->sample_period
) {
4124 hwc
->last_period
= hwc
->sample_period
;
4125 perf_swevent_set_period(event
);
4128 head
= find_swevent_head(cpuctx
, event
->attr
.type
, event
->attr
.config
);
4129 if (WARN_ON_ONCE(!head
))
4132 hlist_add_head_rcu(&event
->hlist_entry
, head
);
4137 static void perf_swevent_disable(struct perf_event
*event
)
4139 hlist_del_rcu(&event
->hlist_entry
);
4142 static const struct pmu perf_ops_generic
= {
4143 .enable
= perf_swevent_enable
,
4144 .disable
= perf_swevent_disable
,
4145 .read
= perf_swevent_read
,
4146 .unthrottle
= perf_swevent_unthrottle
,
4150 * hrtimer based swevent callback
4153 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
4155 enum hrtimer_restart ret
= HRTIMER_RESTART
;
4156 struct perf_sample_data data
;
4157 struct pt_regs
*regs
;
4158 struct perf_event
*event
;
4161 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
4162 event
->pmu
->read(event
);
4164 perf_sample_data_init(&data
, 0);
4165 data
.period
= event
->hw
.last_period
;
4166 regs
= get_irq_regs();
4168 if (regs
&& !perf_exclude_event(event
, regs
)) {
4169 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
4170 if (perf_event_overflow(event
, 0, &data
, regs
))
4171 ret
= HRTIMER_NORESTART
;
4174 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
4175 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
4180 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
4182 struct hw_perf_event
*hwc
= &event
->hw
;
4184 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
4185 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
4186 if (hwc
->sample_period
) {
4189 if (hwc
->remaining
) {
4190 if (hwc
->remaining
< 0)
4193 period
= hwc
->remaining
;
4196 period
= max_t(u64
, 10000, hwc
->sample_period
);
4198 __hrtimer_start_range_ns(&hwc
->hrtimer
,
4199 ns_to_ktime(period
), 0,
4200 HRTIMER_MODE_REL
, 0);
4204 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
4206 struct hw_perf_event
*hwc
= &event
->hw
;
4208 if (hwc
->sample_period
) {
4209 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
4210 hwc
->remaining
= ktime_to_ns(remaining
);
4212 hrtimer_cancel(&hwc
->hrtimer
);
4217 * Software event: cpu wall time clock
4220 static void cpu_clock_perf_event_update(struct perf_event
*event
)
4222 int cpu
= raw_smp_processor_id();
4226 now
= cpu_clock(cpu
);
4227 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4228 atomic64_add(now
- prev
, &event
->count
);
4231 static int cpu_clock_perf_event_enable(struct perf_event
*event
)
4233 struct hw_perf_event
*hwc
= &event
->hw
;
4234 int cpu
= raw_smp_processor_id();
4236 atomic64_set(&hwc
->prev_count
, cpu_clock(cpu
));
4237 perf_swevent_start_hrtimer(event
);
4242 static void cpu_clock_perf_event_disable(struct perf_event
*event
)
4244 perf_swevent_cancel_hrtimer(event
);
4245 cpu_clock_perf_event_update(event
);
4248 static void cpu_clock_perf_event_read(struct perf_event
*event
)
4250 cpu_clock_perf_event_update(event
);
4253 static const struct pmu perf_ops_cpu_clock
= {
4254 .enable
= cpu_clock_perf_event_enable
,
4255 .disable
= cpu_clock_perf_event_disable
,
4256 .read
= cpu_clock_perf_event_read
,
4260 * Software event: task time clock
4263 static void task_clock_perf_event_update(struct perf_event
*event
, u64 now
)
4268 prev
= atomic64_xchg(&event
->hw
.prev_count
, now
);
4270 atomic64_add(delta
, &event
->count
);
4273 static int task_clock_perf_event_enable(struct perf_event
*event
)
4275 struct hw_perf_event
*hwc
= &event
->hw
;
4278 now
= event
->ctx
->time
;
4280 atomic64_set(&hwc
->prev_count
, now
);
4282 perf_swevent_start_hrtimer(event
);
4287 static void task_clock_perf_event_disable(struct perf_event
*event
)
4289 perf_swevent_cancel_hrtimer(event
);
4290 task_clock_perf_event_update(event
, event
->ctx
->time
);
4294 static void task_clock_perf_event_read(struct perf_event
*event
)
4299 update_context_time(event
->ctx
);
4300 time
= event
->ctx
->time
;
4302 u64 now
= perf_clock();
4303 u64 delta
= now
- event
->ctx
->timestamp
;
4304 time
= event
->ctx
->time
+ delta
;
4307 task_clock_perf_event_update(event
, time
);
4310 static const struct pmu perf_ops_task_clock
= {
4311 .enable
= task_clock_perf_event_enable
,
4312 .disable
= task_clock_perf_event_disable
,
4313 .read
= task_clock_perf_event_read
,
4316 #ifdef CONFIG_EVENT_TRACING
4318 void perf_tp_event(int event_id
, u64 addr
, u64 count
, void *record
,
4319 int entry_size
, struct pt_regs
*regs
)
4321 struct perf_sample_data data
;
4322 struct perf_raw_record raw
= {
4327 perf_sample_data_init(&data
, addr
);
4330 /* Trace events already protected against recursion */
4331 do_perf_sw_event(PERF_TYPE_TRACEPOINT
, event_id
, count
, 1,
4334 EXPORT_SYMBOL_GPL(perf_tp_event
);
4336 static int perf_tp_event_match(struct perf_event
*event
,
4337 struct perf_sample_data
*data
)
4339 void *record
= data
->raw
->data
;
4341 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
4346 static void swevent_hlist_release_rcu(struct rcu_head
*rcu_head
)
4348 struct swevent_hlist
*hlist
;
4350 hlist
= container_of(rcu_head
, struct swevent_hlist
, rcu_head
);
4354 static void swevent_hlist_release(struct perf_cpu_context
*cpuctx
)
4356 struct swevent_hlist
*hlist
;
4358 if (!cpuctx
->swevent_hlist
)
4361 hlist
= cpuctx
->swevent_hlist
;
4362 rcu_assign_pointer(cpuctx
->swevent_hlist
, NULL
);
4363 call_rcu(&hlist
->rcu_head
, swevent_hlist_release_rcu
);
4366 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
4368 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
4370 mutex_lock(&cpuctx
->hlist_mutex
);
4372 if (!--cpuctx
->hlist_refcount
)
4373 swevent_hlist_release(cpuctx
);
4375 mutex_unlock(&cpuctx
->hlist_mutex
);
4378 static void swevent_hlist_put(struct perf_event
*event
)
4382 if (event
->cpu
!= -1) {
4383 swevent_hlist_put_cpu(event
, event
->cpu
);
4387 for_each_possible_cpu(cpu
)
4388 swevent_hlist_put_cpu(event
, cpu
);
4391 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
4393 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
4396 mutex_lock(&cpuctx
->hlist_mutex
);
4398 if (!cpuctx
->swevent_hlist
&& cpu_online(cpu
)) {
4399 struct swevent_hlist
*hlist
;
4401 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
4406 rcu_assign_pointer(cpuctx
->swevent_hlist
, hlist
);
4408 cpuctx
->hlist_refcount
++;
4410 mutex_unlock(&cpuctx
->hlist_mutex
);
4415 static int swevent_hlist_get(struct perf_event
*event
)
4418 int cpu
, failed_cpu
;
4420 if (event
->cpu
!= -1)
4421 return swevent_hlist_get_cpu(event
, event
->cpu
);
4424 for_each_possible_cpu(cpu
) {
4425 err
= swevent_hlist_get_cpu(event
, cpu
);
4435 for_each_possible_cpu(cpu
) {
4436 if (cpu
== failed_cpu
)
4438 swevent_hlist_put_cpu(event
, cpu
);
4445 static void tp_perf_event_destroy(struct perf_event
*event
)
4447 perf_trace_disable(event
->attr
.config
);
4448 swevent_hlist_put(event
);
4451 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4456 * Raw tracepoint data is a severe data leak, only allow root to
4459 if ((event
->attr
.sample_type
& PERF_SAMPLE_RAW
) &&
4460 perf_paranoid_tracepoint_raw() &&
4461 !capable(CAP_SYS_ADMIN
))
4462 return ERR_PTR(-EPERM
);
4464 if (perf_trace_enable(event
->attr
.config
))
4467 event
->destroy
= tp_perf_event_destroy
;
4468 err
= swevent_hlist_get(event
);
4470 perf_trace_disable(event
->attr
.config
);
4471 return ERR_PTR(err
);
4474 return &perf_ops_generic
;
4477 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4482 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4485 filter_str
= strndup_user(arg
, PAGE_SIZE
);
4486 if (IS_ERR(filter_str
))
4487 return PTR_ERR(filter_str
);
4489 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
4495 static void perf_event_free_filter(struct perf_event
*event
)
4497 ftrace_profile_free_filter(event
);
4502 static int perf_tp_event_match(struct perf_event
*event
,
4503 struct perf_sample_data
*data
)
4508 static const struct pmu
*tp_perf_event_init(struct perf_event
*event
)
4513 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4518 static void perf_event_free_filter(struct perf_event
*event
)
4522 #endif /* CONFIG_EVENT_TRACING */
4524 #ifdef CONFIG_HAVE_HW_BREAKPOINT
4525 static void bp_perf_event_destroy(struct perf_event
*event
)
4527 release_bp_slot(event
);
4530 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4534 err
= register_perf_hw_breakpoint(bp
);
4536 return ERR_PTR(err
);
4538 bp
->destroy
= bp_perf_event_destroy
;
4540 return &perf_ops_bp
;
4543 void perf_bp_event(struct perf_event
*bp
, void *data
)
4545 struct perf_sample_data sample
;
4546 struct pt_regs
*regs
= data
;
4548 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
4550 if (!perf_exclude_event(bp
, regs
))
4551 perf_swevent_add(bp
, 1, 1, &sample
, regs
);
4554 static const struct pmu
*bp_perf_event_init(struct perf_event
*bp
)
4559 void perf_bp_event(struct perf_event
*bp
, void *regs
)
4564 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4566 static void sw_perf_event_destroy(struct perf_event
*event
)
4568 u64 event_id
= event
->attr
.config
;
4570 WARN_ON(event
->parent
);
4572 atomic_dec(&perf_swevent_enabled
[event_id
]);
4573 swevent_hlist_put(event
);
4576 static const struct pmu
*sw_perf_event_init(struct perf_event
*event
)
4578 const struct pmu
*pmu
= NULL
;
4579 u64 event_id
= event
->attr
.config
;
4582 * Software events (currently) can't in general distinguish
4583 * between user, kernel and hypervisor events.
4584 * However, context switches and cpu migrations are considered
4585 * to be kernel events, and page faults are never hypervisor
4589 case PERF_COUNT_SW_CPU_CLOCK
:
4590 pmu
= &perf_ops_cpu_clock
;
4593 case PERF_COUNT_SW_TASK_CLOCK
:
4595 * If the user instantiates this as a per-cpu event,
4596 * use the cpu_clock event instead.
4598 if (event
->ctx
->task
)
4599 pmu
= &perf_ops_task_clock
;
4601 pmu
= &perf_ops_cpu_clock
;
4604 case PERF_COUNT_SW_PAGE_FAULTS
:
4605 case PERF_COUNT_SW_PAGE_FAULTS_MIN
:
4606 case PERF_COUNT_SW_PAGE_FAULTS_MAJ
:
4607 case PERF_COUNT_SW_CONTEXT_SWITCHES
:
4608 case PERF_COUNT_SW_CPU_MIGRATIONS
:
4609 case PERF_COUNT_SW_ALIGNMENT_FAULTS
:
4610 case PERF_COUNT_SW_EMULATION_FAULTS
:
4611 if (!event
->parent
) {
4614 err
= swevent_hlist_get(event
);
4616 return ERR_PTR(err
);
4618 atomic_inc(&perf_swevent_enabled
[event_id
]);
4619 event
->destroy
= sw_perf_event_destroy
;
4621 pmu
= &perf_ops_generic
;
4629 * Allocate and initialize a event structure
4631 static struct perf_event
*
4632 perf_event_alloc(struct perf_event_attr
*attr
,
4634 struct perf_event_context
*ctx
,
4635 struct perf_event
*group_leader
,
4636 struct perf_event
*parent_event
,
4637 perf_overflow_handler_t overflow_handler
,
4640 const struct pmu
*pmu
;
4641 struct perf_event
*event
;
4642 struct hw_perf_event
*hwc
;
4645 event
= kzalloc(sizeof(*event
), gfpflags
);
4647 return ERR_PTR(-ENOMEM
);
4650 * Single events are their own group leaders, with an
4651 * empty sibling list:
4654 group_leader
= event
;
4656 mutex_init(&event
->child_mutex
);
4657 INIT_LIST_HEAD(&event
->child_list
);
4659 INIT_LIST_HEAD(&event
->group_entry
);
4660 INIT_LIST_HEAD(&event
->event_entry
);
4661 INIT_LIST_HEAD(&event
->sibling_list
);
4662 init_waitqueue_head(&event
->waitq
);
4664 mutex_init(&event
->mmap_mutex
);
4667 event
->attr
= *attr
;
4668 event
->group_leader
= group_leader
;
4673 event
->parent
= parent_event
;
4675 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
4676 event
->id
= atomic64_inc_return(&perf_event_id
);
4678 event
->state
= PERF_EVENT_STATE_INACTIVE
;
4680 if (!overflow_handler
&& parent_event
)
4681 overflow_handler
= parent_event
->overflow_handler
;
4683 event
->overflow_handler
= overflow_handler
;
4686 event
->state
= PERF_EVENT_STATE_OFF
;
4691 hwc
->sample_period
= attr
->sample_period
;
4692 if (attr
->freq
&& attr
->sample_freq
)
4693 hwc
->sample_period
= 1;
4694 hwc
->last_period
= hwc
->sample_period
;
4696 atomic64_set(&hwc
->period_left
, hwc
->sample_period
);
4699 * we currently do not support PERF_FORMAT_GROUP on inherited events
4701 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
4704 switch (attr
->type
) {
4706 case PERF_TYPE_HARDWARE
:
4707 case PERF_TYPE_HW_CACHE
:
4708 pmu
= hw_perf_event_init(event
);
4711 case PERF_TYPE_SOFTWARE
:
4712 pmu
= sw_perf_event_init(event
);
4715 case PERF_TYPE_TRACEPOINT
:
4716 pmu
= tp_perf_event_init(event
);
4719 case PERF_TYPE_BREAKPOINT
:
4720 pmu
= bp_perf_event_init(event
);
4731 else if (IS_ERR(pmu
))
4736 put_pid_ns(event
->ns
);
4738 return ERR_PTR(err
);
4743 if (!event
->parent
) {
4744 atomic_inc(&nr_events
);
4745 if (event
->attr
.mmap
)
4746 atomic_inc(&nr_mmap_events
);
4747 if (event
->attr
.comm
)
4748 atomic_inc(&nr_comm_events
);
4749 if (event
->attr
.task
)
4750 atomic_inc(&nr_task_events
);
4756 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
4757 struct perf_event_attr
*attr
)
4762 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
4766 * zero the full structure, so that a short copy will be nice.
4768 memset(attr
, 0, sizeof(*attr
));
4770 ret
= get_user(size
, &uattr
->size
);
4774 if (size
> PAGE_SIZE
) /* silly large */
4777 if (!size
) /* abi compat */
4778 size
= PERF_ATTR_SIZE_VER0
;
4780 if (size
< PERF_ATTR_SIZE_VER0
)
4784 * If we're handed a bigger struct than we know of,
4785 * ensure all the unknown bits are 0 - i.e. new
4786 * user-space does not rely on any kernel feature
4787 * extensions we dont know about yet.
4789 if (size
> sizeof(*attr
)) {
4790 unsigned char __user
*addr
;
4791 unsigned char __user
*end
;
4794 addr
= (void __user
*)uattr
+ sizeof(*attr
);
4795 end
= (void __user
*)uattr
+ size
;
4797 for (; addr
< end
; addr
++) {
4798 ret
= get_user(val
, addr
);
4804 size
= sizeof(*attr
);
4807 ret
= copy_from_user(attr
, uattr
, size
);
4812 * If the type exists, the corresponding creation will verify
4815 if (attr
->type
>= PERF_TYPE_MAX
)
4818 if (attr
->__reserved_1
)
4821 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
4824 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
4831 put_user(sizeof(*attr
), &uattr
->size
);
4836 static int perf_event_set_output(struct perf_event
*event
, int output_fd
)
4838 struct perf_event
*output_event
= NULL
;
4839 struct file
*output_file
= NULL
;
4840 struct perf_event
*old_output
;
4841 int fput_needed
= 0;
4847 output_file
= fget_light(output_fd
, &fput_needed
);
4851 if (output_file
->f_op
!= &perf_fops
)
4854 output_event
= output_file
->private_data
;
4856 /* Don't chain output fds */
4857 if (output_event
->output
)
4860 /* Don't set an output fd when we already have an output channel */
4864 atomic_long_inc(&output_file
->f_count
);
4867 mutex_lock(&event
->mmap_mutex
);
4868 old_output
= event
->output
;
4869 rcu_assign_pointer(event
->output
, output_event
);
4870 mutex_unlock(&event
->mmap_mutex
);
4874 * we need to make sure no existing perf_output_*()
4875 * is still referencing this event.
4878 fput(old_output
->filp
);
4883 fput_light(output_file
, fput_needed
);
4888 * sys_perf_event_open - open a performance event, associate it to a task/cpu
4890 * @attr_uptr: event_id type attributes for monitoring/sampling
4893 * @group_fd: group leader event fd
4895 SYSCALL_DEFINE5(perf_event_open
,
4896 struct perf_event_attr __user
*, attr_uptr
,
4897 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
4899 struct perf_event
*event
, *group_leader
;
4900 struct perf_event_attr attr
;
4901 struct perf_event_context
*ctx
;
4902 struct file
*event_file
= NULL
;
4903 struct file
*group_file
= NULL
;
4904 int fput_needed
= 0;
4905 int fput_needed2
= 0;
4908 /* for future expandability... */
4909 if (flags
& ~(PERF_FLAG_FD_NO_GROUP
| PERF_FLAG_FD_OUTPUT
))
4912 err
= perf_copy_attr(attr_uptr
, &attr
);
4916 if (!attr
.exclude_kernel
) {
4917 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
4922 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
4927 * Get the target context (task or percpu):
4929 ctx
= find_get_context(pid
, cpu
);
4931 return PTR_ERR(ctx
);
4934 * Look up the group leader (we will attach this event to it):
4936 group_leader
= NULL
;
4937 if (group_fd
!= -1 && !(flags
& PERF_FLAG_FD_NO_GROUP
)) {
4939 group_file
= fget_light(group_fd
, &fput_needed
);
4941 goto err_put_context
;
4942 if (group_file
->f_op
!= &perf_fops
)
4943 goto err_put_context
;
4945 group_leader
= group_file
->private_data
;
4947 * Do not allow a recursive hierarchy (this new sibling
4948 * becoming part of another group-sibling):
4950 if (group_leader
->group_leader
!= group_leader
)
4951 goto err_put_context
;
4953 * Do not allow to attach to a group in a different
4954 * task or CPU context:
4956 if (group_leader
->ctx
!= ctx
)
4957 goto err_put_context
;
4959 * Only a group leader can be exclusive or pinned
4961 if (attr
.exclusive
|| attr
.pinned
)
4962 goto err_put_context
;
4965 event
= perf_event_alloc(&attr
, cpu
, ctx
, group_leader
,
4966 NULL
, NULL
, GFP_KERNEL
);
4967 err
= PTR_ERR(event
);
4969 goto err_put_context
;
4971 err
= anon_inode_getfd("[perf_event]", &perf_fops
, event
, O_RDWR
);
4973 goto err_free_put_context
;
4975 event_file
= fget_light(err
, &fput_needed2
);
4977 goto err_free_put_context
;
4979 if (flags
& PERF_FLAG_FD_OUTPUT
) {
4980 err
= perf_event_set_output(event
, group_fd
);
4982 goto err_fput_free_put_context
;
4985 event
->filp
= event_file
;
4986 WARN_ON_ONCE(ctx
->parent_ctx
);
4987 mutex_lock(&ctx
->mutex
);
4988 perf_install_in_context(ctx
, event
, cpu
);
4990 mutex_unlock(&ctx
->mutex
);
4992 event
->owner
= current
;
4993 get_task_struct(current
);
4994 mutex_lock(¤t
->perf_event_mutex
);
4995 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
4996 mutex_unlock(¤t
->perf_event_mutex
);
4998 err_fput_free_put_context
:
4999 fput_light(event_file
, fput_needed2
);
5001 err_free_put_context
:
5009 fput_light(group_file
, fput_needed
);
5015 * perf_event_create_kernel_counter
5017 * @attr: attributes of the counter to create
5018 * @cpu: cpu in which the counter is bound
5019 * @pid: task to profile
5022 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
5024 perf_overflow_handler_t overflow_handler
)
5026 struct perf_event
*event
;
5027 struct perf_event_context
*ctx
;
5031 * Get the target context (task or percpu):
5034 ctx
= find_get_context(pid
, cpu
);
5040 event
= perf_event_alloc(attr
, cpu
, ctx
, NULL
,
5041 NULL
, overflow_handler
, GFP_KERNEL
);
5042 if (IS_ERR(event
)) {
5043 err
= PTR_ERR(event
);
5044 goto err_put_context
;
5048 WARN_ON_ONCE(ctx
->parent_ctx
);
5049 mutex_lock(&ctx
->mutex
);
5050 perf_install_in_context(ctx
, event
, cpu
);
5052 mutex_unlock(&ctx
->mutex
);
5054 event
->owner
= current
;
5055 get_task_struct(current
);
5056 mutex_lock(¤t
->perf_event_mutex
);
5057 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
5058 mutex_unlock(¤t
->perf_event_mutex
);
5065 return ERR_PTR(err
);
5067 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
5070 * inherit a event from parent task to child task:
5072 static struct perf_event
*
5073 inherit_event(struct perf_event
*parent_event
,
5074 struct task_struct
*parent
,
5075 struct perf_event_context
*parent_ctx
,
5076 struct task_struct
*child
,
5077 struct perf_event
*group_leader
,
5078 struct perf_event_context
*child_ctx
)
5080 struct perf_event
*child_event
;
5083 * Instead of creating recursive hierarchies of events,
5084 * we link inherited events back to the original parent,
5085 * which has a filp for sure, which we use as the reference
5088 if (parent_event
->parent
)
5089 parent_event
= parent_event
->parent
;
5091 child_event
= perf_event_alloc(&parent_event
->attr
,
5092 parent_event
->cpu
, child_ctx
,
5093 group_leader
, parent_event
,
5095 if (IS_ERR(child_event
))
5100 * Make the child state follow the state of the parent event,
5101 * not its attr.disabled bit. We hold the parent's mutex,
5102 * so we won't race with perf_event_{en, dis}able_family.
5104 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
5105 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
5107 child_event
->state
= PERF_EVENT_STATE_OFF
;
5109 if (parent_event
->attr
.freq
) {
5110 u64 sample_period
= parent_event
->hw
.sample_period
;
5111 struct hw_perf_event
*hwc
= &child_event
->hw
;
5113 hwc
->sample_period
= sample_period
;
5114 hwc
->last_period
= sample_period
;
5116 atomic64_set(&hwc
->period_left
, sample_period
);
5119 child_event
->overflow_handler
= parent_event
->overflow_handler
;
5122 * Link it up in the child's context:
5124 add_event_to_ctx(child_event
, child_ctx
);
5127 * Get a reference to the parent filp - we will fput it
5128 * when the child event exits. This is safe to do because
5129 * we are in the parent and we know that the filp still
5130 * exists and has a nonzero count:
5132 atomic_long_inc(&parent_event
->filp
->f_count
);
5135 * Link this into the parent event's child list
5137 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5138 mutex_lock(&parent_event
->child_mutex
);
5139 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
5140 mutex_unlock(&parent_event
->child_mutex
);
5145 static int inherit_group(struct perf_event
*parent_event
,
5146 struct task_struct
*parent
,
5147 struct perf_event_context
*parent_ctx
,
5148 struct task_struct
*child
,
5149 struct perf_event_context
*child_ctx
)
5151 struct perf_event
*leader
;
5152 struct perf_event
*sub
;
5153 struct perf_event
*child_ctr
;
5155 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
5156 child
, NULL
, child_ctx
);
5158 return PTR_ERR(leader
);
5159 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
5160 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
5161 child
, leader
, child_ctx
);
5162 if (IS_ERR(child_ctr
))
5163 return PTR_ERR(child_ctr
);
5168 static void sync_child_event(struct perf_event
*child_event
,
5169 struct task_struct
*child
)
5171 struct perf_event
*parent_event
= child_event
->parent
;
5174 if (child_event
->attr
.inherit_stat
)
5175 perf_event_read_event(child_event
, child
);
5177 child_val
= atomic64_read(&child_event
->count
);
5180 * Add back the child's count to the parent's count:
5182 atomic64_add(child_val
, &parent_event
->count
);
5183 atomic64_add(child_event
->total_time_enabled
,
5184 &parent_event
->child_total_time_enabled
);
5185 atomic64_add(child_event
->total_time_running
,
5186 &parent_event
->child_total_time_running
);
5189 * Remove this event from the parent's list
5191 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5192 mutex_lock(&parent_event
->child_mutex
);
5193 list_del_init(&child_event
->child_list
);
5194 mutex_unlock(&parent_event
->child_mutex
);
5197 * Release the parent event, if this was the last
5200 fput(parent_event
->filp
);
5204 __perf_event_exit_task(struct perf_event
*child_event
,
5205 struct perf_event_context
*child_ctx
,
5206 struct task_struct
*child
)
5208 struct perf_event
*parent_event
;
5210 perf_event_remove_from_context(child_event
);
5212 parent_event
= child_event
->parent
;
5214 * It can happen that parent exits first, and has events
5215 * that are still around due to the child reference. These
5216 * events need to be zapped - but otherwise linger.
5219 sync_child_event(child_event
, child
);
5220 free_event(child_event
);
5225 * When a child task exits, feed back event values to parent events.
5227 void perf_event_exit_task(struct task_struct
*child
)
5229 struct perf_event
*child_event
, *tmp
;
5230 struct perf_event_context
*child_ctx
;
5231 unsigned long flags
;
5233 if (likely(!child
->perf_event_ctxp
)) {
5234 perf_event_task(child
, NULL
, 0);
5238 local_irq_save(flags
);
5240 * We can't reschedule here because interrupts are disabled,
5241 * and either child is current or it is a task that can't be
5242 * scheduled, so we are now safe from rescheduling changing
5245 child_ctx
= child
->perf_event_ctxp
;
5246 __perf_event_task_sched_out(child_ctx
);
5249 * Take the context lock here so that if find_get_context is
5250 * reading child->perf_event_ctxp, we wait until it has
5251 * incremented the context's refcount before we do put_ctx below.
5253 raw_spin_lock(&child_ctx
->lock
);
5254 child
->perf_event_ctxp
= NULL
;
5256 * If this context is a clone; unclone it so it can't get
5257 * swapped to another process while we're removing all
5258 * the events from it.
5260 unclone_ctx(child_ctx
);
5261 update_context_time(child_ctx
);
5262 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
5265 * Report the task dead after unscheduling the events so that we
5266 * won't get any samples after PERF_RECORD_EXIT. We can however still
5267 * get a few PERF_RECORD_READ events.
5269 perf_event_task(child
, child_ctx
, 0);
5272 * We can recurse on the same lock type through:
5274 * __perf_event_exit_task()
5275 * sync_child_event()
5276 * fput(parent_event->filp)
5278 * mutex_lock(&ctx->mutex)
5280 * But since its the parent context it won't be the same instance.
5282 mutex_lock_nested(&child_ctx
->mutex
, SINGLE_DEPTH_NESTING
);
5285 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
5287 __perf_event_exit_task(child_event
, child_ctx
, child
);
5289 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
5291 __perf_event_exit_task(child_event
, child_ctx
, child
);
5294 * If the last event was a group event, it will have appended all
5295 * its siblings to the list, but we obtained 'tmp' before that which
5296 * will still point to the list head terminating the iteration.
5298 if (!list_empty(&child_ctx
->pinned_groups
) ||
5299 !list_empty(&child_ctx
->flexible_groups
))
5302 mutex_unlock(&child_ctx
->mutex
);
5307 static void perf_free_event(struct perf_event
*event
,
5308 struct perf_event_context
*ctx
)
5310 struct perf_event
*parent
= event
->parent
;
5312 if (WARN_ON_ONCE(!parent
))
5315 mutex_lock(&parent
->child_mutex
);
5316 list_del_init(&event
->child_list
);
5317 mutex_unlock(&parent
->child_mutex
);
5321 list_del_event(event
, ctx
);
5326 * free an unexposed, unused context as created by inheritance by
5327 * init_task below, used by fork() in case of fail.
5329 void perf_event_free_task(struct task_struct
*task
)
5331 struct perf_event_context
*ctx
= task
->perf_event_ctxp
;
5332 struct perf_event
*event
, *tmp
;
5337 mutex_lock(&ctx
->mutex
);
5339 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5340 perf_free_event(event
, ctx
);
5342 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
5344 perf_free_event(event
, ctx
);
5346 if (!list_empty(&ctx
->pinned_groups
) ||
5347 !list_empty(&ctx
->flexible_groups
))
5350 mutex_unlock(&ctx
->mutex
);
5356 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
5357 struct perf_event_context
*parent_ctx
,
5358 struct task_struct
*child
,
5362 struct perf_event_context
*child_ctx
= child
->perf_event_ctxp
;
5364 if (!event
->attr
.inherit
) {
5371 * This is executed from the parent task context, so
5372 * inherit events that have been marked for cloning.
5373 * First allocate and initialize a context for the
5377 child_ctx
= kzalloc(sizeof(struct perf_event_context
),
5382 __perf_event_init_context(child_ctx
, child
);
5383 child
->perf_event_ctxp
= child_ctx
;
5384 get_task_struct(child
);
5387 ret
= inherit_group(event
, parent
, parent_ctx
,
5398 * Initialize the perf_event context in task_struct
5400 int perf_event_init_task(struct task_struct
*child
)
5402 struct perf_event_context
*child_ctx
, *parent_ctx
;
5403 struct perf_event_context
*cloned_ctx
;
5404 struct perf_event
*event
;
5405 struct task_struct
*parent
= current
;
5406 int inherited_all
= 1;
5409 child
->perf_event_ctxp
= NULL
;
5411 mutex_init(&child
->perf_event_mutex
);
5412 INIT_LIST_HEAD(&child
->perf_event_list
);
5414 if (likely(!parent
->perf_event_ctxp
))
5418 * If the parent's context is a clone, pin it so it won't get
5421 parent_ctx
= perf_pin_task_context(parent
);
5424 * No need to check if parent_ctx != NULL here; since we saw
5425 * it non-NULL earlier, the only reason for it to become NULL
5426 * is if we exit, and since we're currently in the middle of
5427 * a fork we can't be exiting at the same time.
5431 * Lock the parent list. No need to lock the child - not PID
5432 * hashed yet and not running, so nobody can access it.
5434 mutex_lock(&parent_ctx
->mutex
);
5437 * We dont have to disable NMIs - we are only looking at
5438 * the list, not manipulating it:
5440 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
5441 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5447 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
5448 ret
= inherit_task_group(event
, parent
, parent_ctx
, child
,
5454 child_ctx
= child
->perf_event_ctxp
;
5456 if (child_ctx
&& inherited_all
) {
5458 * Mark the child context as a clone of the parent
5459 * context, or of whatever the parent is a clone of.
5460 * Note that if the parent is a clone, it could get
5461 * uncloned at any point, but that doesn't matter
5462 * because the list of events and the generation
5463 * count can't have changed since we took the mutex.
5465 cloned_ctx
= rcu_dereference(parent_ctx
->parent_ctx
);
5467 child_ctx
->parent_ctx
= cloned_ctx
;
5468 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
5470 child_ctx
->parent_ctx
= parent_ctx
;
5471 child_ctx
->parent_gen
= parent_ctx
->generation
;
5473 get_ctx(child_ctx
->parent_ctx
);
5476 mutex_unlock(&parent_ctx
->mutex
);
5478 perf_unpin_context(parent_ctx
);
5483 static void __init
perf_event_init_all_cpus(void)
5486 struct perf_cpu_context
*cpuctx
;
5488 for_each_possible_cpu(cpu
) {
5489 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5490 mutex_init(&cpuctx
->hlist_mutex
);
5491 __perf_event_init_context(&cpuctx
->ctx
, NULL
);
5495 static void __cpuinit
perf_event_init_cpu(int cpu
)
5497 struct perf_cpu_context
*cpuctx
;
5499 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5501 spin_lock(&perf_resource_lock
);
5502 cpuctx
->max_pertask
= perf_max_events
- perf_reserved_percpu
;
5503 spin_unlock(&perf_resource_lock
);
5505 mutex_lock(&cpuctx
->hlist_mutex
);
5506 if (cpuctx
->hlist_refcount
> 0) {
5507 struct swevent_hlist
*hlist
;
5509 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5510 WARN_ON_ONCE(!hlist
);
5511 rcu_assign_pointer(cpuctx
->swevent_hlist
, hlist
);
5513 mutex_unlock(&cpuctx
->hlist_mutex
);
5516 #ifdef CONFIG_HOTPLUG_CPU
5517 static void __perf_event_exit_cpu(void *info
)
5519 struct perf_cpu_context
*cpuctx
= &__get_cpu_var(perf_cpu_context
);
5520 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5521 struct perf_event
*event
, *tmp
;
5523 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
5524 __perf_event_remove_from_context(event
);
5525 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
5526 __perf_event_remove_from_context(event
);
5528 static void perf_event_exit_cpu(int cpu
)
5530 struct perf_cpu_context
*cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5531 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
5533 mutex_lock(&cpuctx
->hlist_mutex
);
5534 swevent_hlist_release(cpuctx
);
5535 mutex_unlock(&cpuctx
->hlist_mutex
);
5537 mutex_lock(&ctx
->mutex
);
5538 smp_call_function_single(cpu
, __perf_event_exit_cpu
, NULL
, 1);
5539 mutex_unlock(&ctx
->mutex
);
5542 static inline void perf_event_exit_cpu(int cpu
) { }
5545 static int __cpuinit
5546 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
5548 unsigned int cpu
= (long)hcpu
;
5552 case CPU_UP_PREPARE
:
5553 case CPU_UP_PREPARE_FROZEN
:
5554 perf_event_init_cpu(cpu
);
5557 case CPU_DOWN_PREPARE
:
5558 case CPU_DOWN_PREPARE_FROZEN
:
5559 perf_event_exit_cpu(cpu
);
5570 * This has to have a higher priority than migration_notifier in sched.c.
5572 static struct notifier_block __cpuinitdata perf_cpu_nb
= {
5573 .notifier_call
= perf_cpu_notify
,
5577 void __init
perf_event_init(void)
5579 perf_event_init_all_cpus();
5580 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_UP_PREPARE
,
5581 (void *)(long)smp_processor_id());
5582 perf_cpu_notify(&perf_cpu_nb
, (unsigned long)CPU_ONLINE
,
5583 (void *)(long)smp_processor_id());
5584 register_cpu_notifier(&perf_cpu_nb
);
5587 static ssize_t
perf_show_reserve_percpu(struct sysdev_class
*class,
5588 struct sysdev_class_attribute
*attr
,
5591 return sprintf(buf
, "%d\n", perf_reserved_percpu
);
5595 perf_set_reserve_percpu(struct sysdev_class
*class,
5596 struct sysdev_class_attribute
*attr
,
5600 struct perf_cpu_context
*cpuctx
;
5604 err
= strict_strtoul(buf
, 10, &val
);
5607 if (val
> perf_max_events
)
5610 spin_lock(&perf_resource_lock
);
5611 perf_reserved_percpu
= val
;
5612 for_each_online_cpu(cpu
) {
5613 cpuctx
= &per_cpu(perf_cpu_context
, cpu
);
5614 raw_spin_lock_irq(&cpuctx
->ctx
.lock
);
5615 mpt
= min(perf_max_events
- cpuctx
->ctx
.nr_events
,
5616 perf_max_events
- perf_reserved_percpu
);
5617 cpuctx
->max_pertask
= mpt
;
5618 raw_spin_unlock_irq(&cpuctx
->ctx
.lock
);
5620 spin_unlock(&perf_resource_lock
);
5625 static ssize_t
perf_show_overcommit(struct sysdev_class
*class,
5626 struct sysdev_class_attribute
*attr
,
5629 return sprintf(buf
, "%d\n", perf_overcommit
);
5633 perf_set_overcommit(struct sysdev_class
*class,
5634 struct sysdev_class_attribute
*attr
,
5635 const char *buf
, size_t count
)
5640 err
= strict_strtoul(buf
, 10, &val
);
5646 spin_lock(&perf_resource_lock
);
5647 perf_overcommit
= val
;
5648 spin_unlock(&perf_resource_lock
);
5653 static SYSDEV_CLASS_ATTR(
5656 perf_show_reserve_percpu
,
5657 perf_set_reserve_percpu
5660 static SYSDEV_CLASS_ATTR(
5663 perf_show_overcommit
,
5667 static struct attribute
*perfclass_attrs
[] = {
5668 &attr_reserve_percpu
.attr
,
5669 &attr_overcommit
.attr
,
5673 static struct attribute_group perfclass_attr_group
= {
5674 .attrs
= perfclass_attrs
,
5675 .name
= "perf_events",
5678 static int __init
perf_event_sysfs_init(void)
5680 return sysfs_create_group(&cpu_sysdev_class
.kset
.kobj
,
5681 &perfclass_attr_group
);
5683 device_initcall(perf_event_sysfs_init
);