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>
38 atomic_t perf_task_events __read_mostly
;
39 static atomic_t nr_mmap_events __read_mostly
;
40 static atomic_t nr_comm_events __read_mostly
;
41 static atomic_t nr_task_events __read_mostly
;
43 static LIST_HEAD(pmus
);
44 static DEFINE_MUTEX(pmus_lock
);
45 static struct srcu_struct pmus_srcu
;
48 * perf event paranoia level:
49 * -1 - not paranoid at all
50 * 0 - disallow raw tracepoint access for unpriv
51 * 1 - disallow cpu events for unpriv
52 * 2 - disallow kernel profiling for unpriv
54 int sysctl_perf_event_paranoid __read_mostly
= 1;
56 int sysctl_perf_event_mlock __read_mostly
= 512; /* 'free' kb per user */
59 * max perf event sample rate
61 int sysctl_perf_event_sample_rate __read_mostly
= 100000;
63 static atomic64_t perf_event_id
;
65 void __weak
perf_event_print_debug(void) { }
67 extern __weak
const char *perf_pmu_name(void)
72 void perf_pmu_disable(struct pmu
*pmu
)
74 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
76 pmu
->pmu_disable(pmu
);
79 void perf_pmu_enable(struct pmu
*pmu
)
81 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
86 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
89 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
90 * because they're strictly cpu affine and rotate_start is called with IRQs
91 * disabled, while rotate_context is called from IRQ context.
93 static void perf_pmu_rotate_start(struct pmu
*pmu
)
95 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
96 struct list_head
*head
= &__get_cpu_var(rotation_list
);
98 WARN_ON(!irqs_disabled());
100 if (list_empty(&cpuctx
->rotation_list
))
101 list_add(&cpuctx
->rotation_list
, head
);
104 static void get_ctx(struct perf_event_context
*ctx
)
106 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
109 static void free_ctx(struct rcu_head
*head
)
111 struct perf_event_context
*ctx
;
113 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
117 static void put_ctx(struct perf_event_context
*ctx
)
119 if (atomic_dec_and_test(&ctx
->refcount
)) {
121 put_ctx(ctx
->parent_ctx
);
123 put_task_struct(ctx
->task
);
124 call_rcu(&ctx
->rcu_head
, free_ctx
);
128 static void unclone_ctx(struct perf_event_context
*ctx
)
130 if (ctx
->parent_ctx
) {
131 put_ctx(ctx
->parent_ctx
);
132 ctx
->parent_ctx
= NULL
;
136 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
139 * only top level events have the pid namespace they were created in
142 event
= event
->parent
;
144 return task_tgid_nr_ns(p
, event
->ns
);
147 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
150 * only top level events have the pid namespace they were created in
153 event
= event
->parent
;
155 return task_pid_nr_ns(p
, event
->ns
);
159 * If we inherit events we want to return the parent event id
162 static u64
primary_event_id(struct perf_event
*event
)
167 id
= event
->parent
->id
;
173 * Get the perf_event_context for a task and lock it.
174 * This has to cope with with the fact that until it is locked,
175 * the context could get moved to another task.
177 static struct perf_event_context
*
178 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
180 struct perf_event_context
*ctx
;
184 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
187 * If this context is a clone of another, it might
188 * get swapped for another underneath us by
189 * perf_event_task_sched_out, though the
190 * rcu_read_lock() protects us from any context
191 * getting freed. Lock the context and check if it
192 * got swapped before we could get the lock, and retry
193 * if so. If we locked the right context, then it
194 * can't get swapped on us any more.
196 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
197 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
198 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
202 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
203 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
212 * Get the context for a task and increment its pin_count so it
213 * can't get swapped to another task. This also increments its
214 * reference count so that the context can't get freed.
216 static struct perf_event_context
*
217 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
219 struct perf_event_context
*ctx
;
222 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
225 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
230 static void perf_unpin_context(struct perf_event_context
*ctx
)
234 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
236 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
240 static inline u64
perf_clock(void)
242 return local_clock();
246 * Update the record of the current time in a context.
248 static void update_context_time(struct perf_event_context
*ctx
)
250 u64 now
= perf_clock();
252 ctx
->time
+= now
- ctx
->timestamp
;
253 ctx
->timestamp
= now
;
257 * Update the total_time_enabled and total_time_running fields for a event.
259 static void update_event_times(struct perf_event
*event
)
261 struct perf_event_context
*ctx
= event
->ctx
;
264 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
265 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
271 run_end
= event
->tstamp_stopped
;
273 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
275 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
276 run_end
= event
->tstamp_stopped
;
280 event
->total_time_running
= run_end
- event
->tstamp_running
;
284 * Update total_time_enabled and total_time_running for all events in a group.
286 static void update_group_times(struct perf_event
*leader
)
288 struct perf_event
*event
;
290 update_event_times(leader
);
291 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
292 update_event_times(event
);
295 static struct list_head
*
296 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
298 if (event
->attr
.pinned
)
299 return &ctx
->pinned_groups
;
301 return &ctx
->flexible_groups
;
305 * Add a event from the lists for its context.
306 * Must be called with ctx->mutex and ctx->lock held.
309 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
311 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
312 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
315 * If we're a stand alone event or group leader, we go to the context
316 * list, group events are kept attached to the group so that
317 * perf_group_detach can, at all times, locate all siblings.
319 if (event
->group_leader
== event
) {
320 struct list_head
*list
;
322 if (is_software_event(event
))
323 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
325 list
= ctx_group_list(event
, ctx
);
326 list_add_tail(&event
->group_entry
, list
);
329 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
331 perf_pmu_rotate_start(ctx
->pmu
);
333 if (event
->attr
.inherit_stat
)
338 * Called at perf_event creation and when events are attached/detached from a
341 static void perf_event__read_size(struct perf_event
*event
)
343 int entry
= sizeof(u64
); /* value */
347 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
350 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
353 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
354 entry
+= sizeof(u64
);
356 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
357 nr
+= event
->group_leader
->nr_siblings
;
362 event
->read_size
= size
;
365 static void perf_event__header_size(struct perf_event
*event
)
367 struct perf_sample_data
*data
;
368 u64 sample_type
= event
->attr
.sample_type
;
371 perf_event__read_size(event
);
373 if (sample_type
& PERF_SAMPLE_IP
)
374 size
+= sizeof(data
->ip
);
376 if (sample_type
& PERF_SAMPLE_ADDR
)
377 size
+= sizeof(data
->addr
);
379 if (sample_type
& PERF_SAMPLE_PERIOD
)
380 size
+= sizeof(data
->period
);
382 if (sample_type
& PERF_SAMPLE_READ
)
383 size
+= event
->read_size
;
385 event
->header_size
= size
;
388 static void perf_event__id_header_size(struct perf_event
*event
)
390 struct perf_sample_data
*data
;
391 u64 sample_type
= event
->attr
.sample_type
;
394 if (sample_type
& PERF_SAMPLE_TID
)
395 size
+= sizeof(data
->tid_entry
);
397 if (sample_type
& PERF_SAMPLE_TIME
)
398 size
+= sizeof(data
->time
);
400 if (sample_type
& PERF_SAMPLE_ID
)
401 size
+= sizeof(data
->id
);
403 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
404 size
+= sizeof(data
->stream_id
);
406 if (sample_type
& PERF_SAMPLE_CPU
)
407 size
+= sizeof(data
->cpu_entry
);
409 event
->id_header_size
= size
;
412 static void perf_group_attach(struct perf_event
*event
)
414 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
417 * We can have double attach due to group movement in perf_event_open.
419 if (event
->attach_state
& PERF_ATTACH_GROUP
)
422 event
->attach_state
|= PERF_ATTACH_GROUP
;
424 if (group_leader
== event
)
427 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
428 !is_software_event(event
))
429 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
431 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
432 group_leader
->nr_siblings
++;
434 perf_event__header_size(group_leader
);
436 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
437 perf_event__header_size(pos
);
441 * Remove a event from the lists for its context.
442 * Must be called with ctx->mutex and ctx->lock held.
445 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
448 * We can have double detach due to exit/hot-unplug + close.
450 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
453 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
456 if (event
->attr
.inherit_stat
)
459 list_del_rcu(&event
->event_entry
);
461 if (event
->group_leader
== event
)
462 list_del_init(&event
->group_entry
);
464 update_group_times(event
);
467 * If event was in error state, then keep it
468 * that way, otherwise bogus counts will be
469 * returned on read(). The only way to get out
470 * of error state is by explicit re-enabling
473 if (event
->state
> PERF_EVENT_STATE_OFF
)
474 event
->state
= PERF_EVENT_STATE_OFF
;
477 static void perf_group_detach(struct perf_event
*event
)
479 struct perf_event
*sibling
, *tmp
;
480 struct list_head
*list
= NULL
;
483 * We can have double detach due to exit/hot-unplug + close.
485 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
488 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
491 * If this is a sibling, remove it from its group.
493 if (event
->group_leader
!= event
) {
494 list_del_init(&event
->group_entry
);
495 event
->group_leader
->nr_siblings
--;
499 if (!list_empty(&event
->group_entry
))
500 list
= &event
->group_entry
;
503 * If this was a group event with sibling events then
504 * upgrade the siblings to singleton events by adding them
505 * to whatever list we are on.
507 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
509 list_move_tail(&sibling
->group_entry
, list
);
510 sibling
->group_leader
= sibling
;
512 /* Inherit group flags from the previous leader */
513 sibling
->group_flags
= event
->group_flags
;
517 perf_event__header_size(event
->group_leader
);
519 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
520 perf_event__header_size(tmp
);
524 event_filter_match(struct perf_event
*event
)
526 return event
->cpu
== -1 || event
->cpu
== smp_processor_id();
530 event_sched_out(struct perf_event
*event
,
531 struct perf_cpu_context
*cpuctx
,
532 struct perf_event_context
*ctx
)
536 * An event which could not be activated because of
537 * filter mismatch still needs to have its timings
538 * maintained, otherwise bogus information is return
539 * via read() for time_enabled, time_running:
541 if (event
->state
== PERF_EVENT_STATE_INACTIVE
542 && !event_filter_match(event
)) {
543 delta
= ctx
->time
- event
->tstamp_stopped
;
544 event
->tstamp_running
+= delta
;
545 event
->tstamp_stopped
= ctx
->time
;
548 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
551 event
->state
= PERF_EVENT_STATE_INACTIVE
;
552 if (event
->pending_disable
) {
553 event
->pending_disable
= 0;
554 event
->state
= PERF_EVENT_STATE_OFF
;
556 event
->tstamp_stopped
= ctx
->time
;
557 event
->pmu
->del(event
, 0);
560 if (!is_software_event(event
))
561 cpuctx
->active_oncpu
--;
563 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
564 cpuctx
->exclusive
= 0;
568 group_sched_out(struct perf_event
*group_event
,
569 struct perf_cpu_context
*cpuctx
,
570 struct perf_event_context
*ctx
)
572 struct perf_event
*event
;
573 int state
= group_event
->state
;
575 event_sched_out(group_event
, cpuctx
, ctx
);
578 * Schedule out siblings (if any):
580 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
581 event_sched_out(event
, cpuctx
, ctx
);
583 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
584 cpuctx
->exclusive
= 0;
587 static inline struct perf_cpu_context
*
588 __get_cpu_context(struct perf_event_context
*ctx
)
590 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
594 * Cross CPU call to remove a performance event
596 * We disable the event on the hardware level first. After that we
597 * remove it from the context list.
599 static void __perf_event_remove_from_context(void *info
)
601 struct perf_event
*event
= info
;
602 struct perf_event_context
*ctx
= event
->ctx
;
603 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
606 * If this is a task context, we need to check whether it is
607 * the current task context of this cpu. If not it has been
608 * scheduled out before the smp call arrived.
610 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
613 raw_spin_lock(&ctx
->lock
);
615 event_sched_out(event
, cpuctx
, ctx
);
617 list_del_event(event
, ctx
);
619 raw_spin_unlock(&ctx
->lock
);
624 * Remove the event from a task's (or a CPU's) list of events.
626 * Must be called with ctx->mutex held.
628 * CPU events are removed with a smp call. For task events we only
629 * call when the task is on a CPU.
631 * If event->ctx is a cloned context, callers must make sure that
632 * every task struct that event->ctx->task could possibly point to
633 * remains valid. This is OK when called from perf_release since
634 * that only calls us on the top-level context, which can't be a clone.
635 * When called from perf_event_exit_task, it's OK because the
636 * context has been detached from its task.
638 static void perf_event_remove_from_context(struct perf_event
*event
)
640 struct perf_event_context
*ctx
= event
->ctx
;
641 struct task_struct
*task
= ctx
->task
;
645 * Per cpu events are removed via an smp call and
646 * the removal is always successful.
648 smp_call_function_single(event
->cpu
,
649 __perf_event_remove_from_context
,
655 task_oncpu_function_call(task
, __perf_event_remove_from_context
,
658 raw_spin_lock_irq(&ctx
->lock
);
660 * If the context is active we need to retry the smp call.
662 if (ctx
->nr_active
&& !list_empty(&event
->group_entry
)) {
663 raw_spin_unlock_irq(&ctx
->lock
);
668 * The lock prevents that this context is scheduled in so we
669 * can remove the event safely, if the call above did not
672 if (!list_empty(&event
->group_entry
))
673 list_del_event(event
, ctx
);
674 raw_spin_unlock_irq(&ctx
->lock
);
678 * Cross CPU call to disable a performance event
680 static void __perf_event_disable(void *info
)
682 struct perf_event
*event
= info
;
683 struct perf_event_context
*ctx
= event
->ctx
;
684 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
687 * If this is a per-task event, need to check whether this
688 * event's task is the current task on this cpu.
690 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
693 raw_spin_lock(&ctx
->lock
);
696 * If the event is on, turn it off.
697 * If it is in error state, leave it in error state.
699 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
700 update_context_time(ctx
);
701 update_group_times(event
);
702 if (event
== event
->group_leader
)
703 group_sched_out(event
, cpuctx
, ctx
);
705 event_sched_out(event
, cpuctx
, ctx
);
706 event
->state
= PERF_EVENT_STATE_OFF
;
709 raw_spin_unlock(&ctx
->lock
);
715 * If event->ctx is a cloned context, callers must make sure that
716 * every task struct that event->ctx->task could possibly point to
717 * remains valid. This condition is satisifed when called through
718 * perf_event_for_each_child or perf_event_for_each because they
719 * hold the top-level event's child_mutex, so any descendant that
720 * goes to exit will block in sync_child_event.
721 * When called from perf_pending_event it's OK because event->ctx
722 * is the current context on this CPU and preemption is disabled,
723 * hence we can't get into perf_event_task_sched_out for this context.
725 void perf_event_disable(struct perf_event
*event
)
727 struct perf_event_context
*ctx
= event
->ctx
;
728 struct task_struct
*task
= ctx
->task
;
732 * Disable the event on the cpu that it's on
734 smp_call_function_single(event
->cpu
, __perf_event_disable
,
740 task_oncpu_function_call(task
, __perf_event_disable
, event
);
742 raw_spin_lock_irq(&ctx
->lock
);
744 * If the event is still active, we need to retry the cross-call.
746 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
747 raw_spin_unlock_irq(&ctx
->lock
);
752 * Since we have the lock this context can't be scheduled
753 * in, so we can change the state safely.
755 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
756 update_group_times(event
);
757 event
->state
= PERF_EVENT_STATE_OFF
;
760 raw_spin_unlock_irq(&ctx
->lock
);
764 event_sched_in(struct perf_event
*event
,
765 struct perf_cpu_context
*cpuctx
,
766 struct perf_event_context
*ctx
)
768 if (event
->state
<= PERF_EVENT_STATE_OFF
)
771 event
->state
= PERF_EVENT_STATE_ACTIVE
;
772 event
->oncpu
= smp_processor_id();
774 * The new state must be visible before we turn it on in the hardware:
778 if (event
->pmu
->add(event
, PERF_EF_START
)) {
779 event
->state
= PERF_EVENT_STATE_INACTIVE
;
784 event
->tstamp_running
+= ctx
->time
- event
->tstamp_stopped
;
786 event
->shadow_ctx_time
= ctx
->time
- ctx
->timestamp
;
788 if (!is_software_event(event
))
789 cpuctx
->active_oncpu
++;
792 if (event
->attr
.exclusive
)
793 cpuctx
->exclusive
= 1;
799 group_sched_in(struct perf_event
*group_event
,
800 struct perf_cpu_context
*cpuctx
,
801 struct perf_event_context
*ctx
)
803 struct perf_event
*event
, *partial_group
= NULL
;
804 struct pmu
*pmu
= group_event
->pmu
;
806 bool simulate
= false;
808 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
813 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
814 pmu
->cancel_txn(pmu
);
819 * Schedule in siblings as one group (if any):
821 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
822 if (event_sched_in(event
, cpuctx
, ctx
)) {
823 partial_group
= event
;
828 if (!pmu
->commit_txn(pmu
))
833 * Groups can be scheduled in as one unit only, so undo any
834 * partial group before returning:
835 * The events up to the failed event are scheduled out normally,
836 * tstamp_stopped will be updated.
838 * The failed events and the remaining siblings need to have
839 * their timings updated as if they had gone thru event_sched_in()
840 * and event_sched_out(). This is required to get consistent timings
841 * across the group. This also takes care of the case where the group
842 * could never be scheduled by ensuring tstamp_stopped is set to mark
843 * the time the event was actually stopped, such that time delta
844 * calculation in update_event_times() is correct.
846 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
847 if (event
== partial_group
)
851 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
852 event
->tstamp_stopped
= now
;
854 event_sched_out(event
, cpuctx
, ctx
);
857 event_sched_out(group_event
, cpuctx
, ctx
);
859 pmu
->cancel_txn(pmu
);
865 * Work out whether we can put this event group on the CPU now.
867 static int group_can_go_on(struct perf_event
*event
,
868 struct perf_cpu_context
*cpuctx
,
872 * Groups consisting entirely of software events can always go on.
874 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
877 * If an exclusive group is already on, no other hardware
880 if (cpuctx
->exclusive
)
883 * If this group is exclusive and there are already
884 * events on the CPU, it can't go on.
886 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
889 * Otherwise, try to add it if all previous groups were able
895 static void add_event_to_ctx(struct perf_event
*event
,
896 struct perf_event_context
*ctx
)
898 list_add_event(event
, ctx
);
899 perf_group_attach(event
);
900 event
->tstamp_enabled
= ctx
->time
;
901 event
->tstamp_running
= ctx
->time
;
902 event
->tstamp_stopped
= ctx
->time
;
906 * Cross CPU call to install and enable a performance event
908 * Must be called with ctx->mutex held
910 static void __perf_install_in_context(void *info
)
912 struct perf_event
*event
= info
;
913 struct perf_event_context
*ctx
= event
->ctx
;
914 struct perf_event
*leader
= event
->group_leader
;
915 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
919 * If this is a task context, we need to check whether it is
920 * the current task context of this cpu. If not it has been
921 * scheduled out before the smp call arrived.
922 * Or possibly this is the right context but it isn't
923 * on this cpu because it had no events.
925 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
926 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
928 cpuctx
->task_ctx
= ctx
;
931 raw_spin_lock(&ctx
->lock
);
933 update_context_time(ctx
);
935 add_event_to_ctx(event
, ctx
);
937 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
941 * Don't put the event on if it is disabled or if
942 * it is in a group and the group isn't on.
944 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
945 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
949 * An exclusive event can't go on if there are already active
950 * hardware events, and no hardware event can go on if there
951 * is already an exclusive event on.
953 if (!group_can_go_on(event
, cpuctx
, 1))
956 err
= event_sched_in(event
, cpuctx
, ctx
);
960 * This event couldn't go on. If it is in a group
961 * then we have to pull the whole group off.
962 * If the event group is pinned then put it in error state.
965 group_sched_out(leader
, cpuctx
, ctx
);
966 if (leader
->attr
.pinned
) {
967 update_group_times(leader
);
968 leader
->state
= PERF_EVENT_STATE_ERROR
;
973 raw_spin_unlock(&ctx
->lock
);
977 * Attach a performance event to a context
979 * First we add the event to the list with the hardware enable bit
980 * in event->hw_config cleared.
982 * If the event is attached to a task which is on a CPU we use a smp
983 * call to enable it in the task context. The task might have been
984 * scheduled away, but we check this in the smp call again.
986 * Must be called with ctx->mutex held.
989 perf_install_in_context(struct perf_event_context
*ctx
,
990 struct perf_event
*event
,
993 struct task_struct
*task
= ctx
->task
;
999 * Per cpu events are installed via an smp call and
1000 * the install is always successful.
1002 smp_call_function_single(cpu
, __perf_install_in_context
,
1008 task_oncpu_function_call(task
, __perf_install_in_context
,
1011 raw_spin_lock_irq(&ctx
->lock
);
1013 * we need to retry the smp call.
1015 if (ctx
->is_active
&& list_empty(&event
->group_entry
)) {
1016 raw_spin_unlock_irq(&ctx
->lock
);
1021 * The lock prevents that this context is scheduled in so we
1022 * can add the event safely, if it the call above did not
1025 if (list_empty(&event
->group_entry
))
1026 add_event_to_ctx(event
, ctx
);
1027 raw_spin_unlock_irq(&ctx
->lock
);
1031 * Put a event into inactive state and update time fields.
1032 * Enabling the leader of a group effectively enables all
1033 * the group members that aren't explicitly disabled, so we
1034 * have to update their ->tstamp_enabled also.
1035 * Note: this works for group members as well as group leaders
1036 * since the non-leader members' sibling_lists will be empty.
1038 static void __perf_event_mark_enabled(struct perf_event
*event
,
1039 struct perf_event_context
*ctx
)
1041 struct perf_event
*sub
;
1043 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1044 event
->tstamp_enabled
= ctx
->time
- event
->total_time_enabled
;
1045 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1046 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1047 sub
->tstamp_enabled
=
1048 ctx
->time
- sub
->total_time_enabled
;
1054 * Cross CPU call to enable a performance event
1056 static void __perf_event_enable(void *info
)
1058 struct perf_event
*event
= info
;
1059 struct perf_event_context
*ctx
= event
->ctx
;
1060 struct perf_event
*leader
= event
->group_leader
;
1061 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1065 * If this is a per-task event, need to check whether this
1066 * event's task is the current task on this cpu.
1068 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
1069 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
1071 cpuctx
->task_ctx
= ctx
;
1074 raw_spin_lock(&ctx
->lock
);
1076 update_context_time(ctx
);
1078 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1080 __perf_event_mark_enabled(event
, ctx
);
1082 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1086 * If the event is in a group and isn't the group leader,
1087 * then don't put it on unless the group is on.
1089 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1092 if (!group_can_go_on(event
, cpuctx
, 1)) {
1095 if (event
== leader
)
1096 err
= group_sched_in(event
, cpuctx
, ctx
);
1098 err
= event_sched_in(event
, cpuctx
, ctx
);
1103 * If this event can't go on and it's part of a
1104 * group, then the whole group has to come off.
1106 if (leader
!= event
)
1107 group_sched_out(leader
, cpuctx
, ctx
);
1108 if (leader
->attr
.pinned
) {
1109 update_group_times(leader
);
1110 leader
->state
= PERF_EVENT_STATE_ERROR
;
1115 raw_spin_unlock(&ctx
->lock
);
1121 * If event->ctx is a cloned context, callers must make sure that
1122 * every task struct that event->ctx->task could possibly point to
1123 * remains valid. This condition is satisfied when called through
1124 * perf_event_for_each_child or perf_event_for_each as described
1125 * for perf_event_disable.
1127 void perf_event_enable(struct perf_event
*event
)
1129 struct perf_event_context
*ctx
= event
->ctx
;
1130 struct task_struct
*task
= ctx
->task
;
1134 * Enable the event on the cpu that it's on
1136 smp_call_function_single(event
->cpu
, __perf_event_enable
,
1141 raw_spin_lock_irq(&ctx
->lock
);
1142 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1146 * If the event is in error state, clear that first.
1147 * That way, if we see the event in error state below, we
1148 * know that it has gone back into error state, as distinct
1149 * from the task having been scheduled away before the
1150 * cross-call arrived.
1152 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1153 event
->state
= PERF_EVENT_STATE_OFF
;
1156 raw_spin_unlock_irq(&ctx
->lock
);
1157 task_oncpu_function_call(task
, __perf_event_enable
, event
);
1159 raw_spin_lock_irq(&ctx
->lock
);
1162 * If the context is active and the event is still off,
1163 * we need to retry the cross-call.
1165 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
)
1169 * Since we have the lock this context can't be scheduled
1170 * in, so we can change the state safely.
1172 if (event
->state
== PERF_EVENT_STATE_OFF
)
1173 __perf_event_mark_enabled(event
, ctx
);
1176 raw_spin_unlock_irq(&ctx
->lock
);
1179 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1182 * not supported on inherited events
1184 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1187 atomic_add(refresh
, &event
->event_limit
);
1188 perf_event_enable(event
);
1194 EVENT_FLEXIBLE
= 0x1,
1196 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
1199 static void ctx_sched_out(struct perf_event_context
*ctx
,
1200 struct perf_cpu_context
*cpuctx
,
1201 enum event_type_t event_type
)
1203 struct perf_event
*event
;
1205 raw_spin_lock(&ctx
->lock
);
1206 perf_pmu_disable(ctx
->pmu
);
1208 if (likely(!ctx
->nr_events
))
1210 update_context_time(ctx
);
1212 if (!ctx
->nr_active
)
1215 if (event_type
& EVENT_PINNED
) {
1216 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1217 group_sched_out(event
, cpuctx
, ctx
);
1220 if (event_type
& EVENT_FLEXIBLE
) {
1221 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1222 group_sched_out(event
, cpuctx
, ctx
);
1225 perf_pmu_enable(ctx
->pmu
);
1226 raw_spin_unlock(&ctx
->lock
);
1230 * Test whether two contexts are equivalent, i.e. whether they
1231 * have both been cloned from the same version of the same context
1232 * and they both have the same number of enabled events.
1233 * If the number of enabled events is the same, then the set
1234 * of enabled events should be the same, because these are both
1235 * inherited contexts, therefore we can't access individual events
1236 * in them directly with an fd; we can only enable/disable all
1237 * events via prctl, or enable/disable all events in a family
1238 * via ioctl, which will have the same effect on both contexts.
1240 static int context_equiv(struct perf_event_context
*ctx1
,
1241 struct perf_event_context
*ctx2
)
1243 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1244 && ctx1
->parent_gen
== ctx2
->parent_gen
1245 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1248 static void __perf_event_sync_stat(struct perf_event
*event
,
1249 struct perf_event
*next_event
)
1253 if (!event
->attr
.inherit_stat
)
1257 * Update the event value, we cannot use perf_event_read()
1258 * because we're in the middle of a context switch and have IRQs
1259 * disabled, which upsets smp_call_function_single(), however
1260 * we know the event must be on the current CPU, therefore we
1261 * don't need to use it.
1263 switch (event
->state
) {
1264 case PERF_EVENT_STATE_ACTIVE
:
1265 event
->pmu
->read(event
);
1268 case PERF_EVENT_STATE_INACTIVE
:
1269 update_event_times(event
);
1277 * In order to keep per-task stats reliable we need to flip the event
1278 * values when we flip the contexts.
1280 value
= local64_read(&next_event
->count
);
1281 value
= local64_xchg(&event
->count
, value
);
1282 local64_set(&next_event
->count
, value
);
1284 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1285 swap(event
->total_time_running
, next_event
->total_time_running
);
1288 * Since we swizzled the values, update the user visible data too.
1290 perf_event_update_userpage(event
);
1291 perf_event_update_userpage(next_event
);
1294 #define list_next_entry(pos, member) \
1295 list_entry(pos->member.next, typeof(*pos), member)
1297 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1298 struct perf_event_context
*next_ctx
)
1300 struct perf_event
*event
, *next_event
;
1305 update_context_time(ctx
);
1307 event
= list_first_entry(&ctx
->event_list
,
1308 struct perf_event
, event_entry
);
1310 next_event
= list_first_entry(&next_ctx
->event_list
,
1311 struct perf_event
, event_entry
);
1313 while (&event
->event_entry
!= &ctx
->event_list
&&
1314 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1316 __perf_event_sync_stat(event
, next_event
);
1318 event
= list_next_entry(event
, event_entry
);
1319 next_event
= list_next_entry(next_event
, event_entry
);
1323 void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
1324 struct task_struct
*next
)
1326 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
1327 struct perf_event_context
*next_ctx
;
1328 struct perf_event_context
*parent
;
1329 struct perf_cpu_context
*cpuctx
;
1335 cpuctx
= __get_cpu_context(ctx
);
1336 if (!cpuctx
->task_ctx
)
1340 parent
= rcu_dereference(ctx
->parent_ctx
);
1341 next_ctx
= next
->perf_event_ctxp
[ctxn
];
1342 if (parent
&& next_ctx
&&
1343 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1345 * Looks like the two contexts are clones, so we might be
1346 * able to optimize the context switch. We lock both
1347 * contexts and check that they are clones under the
1348 * lock (including re-checking that neither has been
1349 * uncloned in the meantime). It doesn't matter which
1350 * order we take the locks because no other cpu could
1351 * be trying to lock both of these tasks.
1353 raw_spin_lock(&ctx
->lock
);
1354 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1355 if (context_equiv(ctx
, next_ctx
)) {
1357 * XXX do we need a memory barrier of sorts
1358 * wrt to rcu_dereference() of perf_event_ctxp
1360 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
1361 next
->perf_event_ctxp
[ctxn
] = ctx
;
1363 next_ctx
->task
= task
;
1366 perf_event_sync_stat(ctx
, next_ctx
);
1368 raw_spin_unlock(&next_ctx
->lock
);
1369 raw_spin_unlock(&ctx
->lock
);
1374 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1375 cpuctx
->task_ctx
= NULL
;
1379 #define for_each_task_context_nr(ctxn) \
1380 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
1383 * Called from scheduler to remove the events of the current task,
1384 * with interrupts disabled.
1386 * We stop each event and update the event value in event->count.
1388 * This does not protect us against NMI, but disable()
1389 * sets the disabled bit in the control field of event _before_
1390 * accessing the event control register. If a NMI hits, then it will
1391 * not restart the event.
1393 void __perf_event_task_sched_out(struct task_struct
*task
,
1394 struct task_struct
*next
)
1398 for_each_task_context_nr(ctxn
)
1399 perf_event_context_sched_out(task
, ctxn
, next
);
1402 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1403 enum event_type_t event_type
)
1405 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1407 if (!cpuctx
->task_ctx
)
1410 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1413 ctx_sched_out(ctx
, cpuctx
, event_type
);
1414 cpuctx
->task_ctx
= NULL
;
1418 * Called with IRQs disabled
1420 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1421 enum event_type_t event_type
)
1423 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1427 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1428 struct perf_cpu_context
*cpuctx
)
1430 struct perf_event
*event
;
1432 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1433 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1435 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1438 if (group_can_go_on(event
, cpuctx
, 1))
1439 group_sched_in(event
, cpuctx
, ctx
);
1442 * If this pinned group hasn't been scheduled,
1443 * put it in error state.
1445 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1446 update_group_times(event
);
1447 event
->state
= PERF_EVENT_STATE_ERROR
;
1453 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
1454 struct perf_cpu_context
*cpuctx
)
1456 struct perf_event
*event
;
1459 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1460 /* Ignore events in OFF or ERROR state */
1461 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1464 * Listen to the 'cpu' scheduling filter constraint
1467 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1470 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
1471 if (group_sched_in(event
, cpuctx
, ctx
))
1478 ctx_sched_in(struct perf_event_context
*ctx
,
1479 struct perf_cpu_context
*cpuctx
,
1480 enum event_type_t event_type
)
1482 raw_spin_lock(&ctx
->lock
);
1484 if (likely(!ctx
->nr_events
))
1487 ctx
->timestamp
= perf_clock();
1490 * First go through the list and put on any pinned groups
1491 * in order to give them the best chance of going on.
1493 if (event_type
& EVENT_PINNED
)
1494 ctx_pinned_sched_in(ctx
, cpuctx
);
1496 /* Then walk through the lower prio flexible groups */
1497 if (event_type
& EVENT_FLEXIBLE
)
1498 ctx_flexible_sched_in(ctx
, cpuctx
);
1501 raw_spin_unlock(&ctx
->lock
);
1504 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
1505 enum event_type_t event_type
)
1507 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
1509 ctx_sched_in(ctx
, cpuctx
, event_type
);
1512 static void task_ctx_sched_in(struct perf_event_context
*ctx
,
1513 enum event_type_t event_type
)
1515 struct perf_cpu_context
*cpuctx
;
1517 cpuctx
= __get_cpu_context(ctx
);
1518 if (cpuctx
->task_ctx
== ctx
)
1521 ctx_sched_in(ctx
, cpuctx
, event_type
);
1522 cpuctx
->task_ctx
= ctx
;
1525 void perf_event_context_sched_in(struct perf_event_context
*ctx
)
1527 struct perf_cpu_context
*cpuctx
;
1529 cpuctx
= __get_cpu_context(ctx
);
1530 if (cpuctx
->task_ctx
== ctx
)
1533 perf_pmu_disable(ctx
->pmu
);
1535 * We want to keep the following priority order:
1536 * cpu pinned (that don't need to move), task pinned,
1537 * cpu flexible, task flexible.
1539 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1541 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
);
1542 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1543 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
);
1545 cpuctx
->task_ctx
= ctx
;
1548 * Since these rotations are per-cpu, we need to ensure the
1549 * cpu-context we got scheduled on is actually rotating.
1551 perf_pmu_rotate_start(ctx
->pmu
);
1552 perf_pmu_enable(ctx
->pmu
);
1556 * Called from scheduler to add the events of the current task
1557 * with interrupts disabled.
1559 * We restore the event value and then enable it.
1561 * This does not protect us against NMI, but enable()
1562 * sets the enabled bit in the control field of event _before_
1563 * accessing the event control register. If a NMI hits, then it will
1564 * keep the event running.
1566 void __perf_event_task_sched_in(struct task_struct
*task
)
1568 struct perf_event_context
*ctx
;
1571 for_each_task_context_nr(ctxn
) {
1572 ctx
= task
->perf_event_ctxp
[ctxn
];
1576 perf_event_context_sched_in(ctx
);
1580 #define MAX_INTERRUPTS (~0ULL)
1582 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1584 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1586 u64 frequency
= event
->attr
.sample_freq
;
1587 u64 sec
= NSEC_PER_SEC
;
1588 u64 divisor
, dividend
;
1590 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
1592 count_fls
= fls64(count
);
1593 nsec_fls
= fls64(nsec
);
1594 frequency_fls
= fls64(frequency
);
1598 * We got @count in @nsec, with a target of sample_freq HZ
1599 * the target period becomes:
1602 * period = -------------------
1603 * @nsec * sample_freq
1608 * Reduce accuracy by one bit such that @a and @b converge
1609 * to a similar magnitude.
1611 #define REDUCE_FLS(a, b) \
1613 if (a##_fls > b##_fls) { \
1623 * Reduce accuracy until either term fits in a u64, then proceed with
1624 * the other, so that finally we can do a u64/u64 division.
1626 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
1627 REDUCE_FLS(nsec
, frequency
);
1628 REDUCE_FLS(sec
, count
);
1631 if (count_fls
+ sec_fls
> 64) {
1632 divisor
= nsec
* frequency
;
1634 while (count_fls
+ sec_fls
> 64) {
1635 REDUCE_FLS(count
, sec
);
1639 dividend
= count
* sec
;
1641 dividend
= count
* sec
;
1643 while (nsec_fls
+ frequency_fls
> 64) {
1644 REDUCE_FLS(nsec
, frequency
);
1648 divisor
= nsec
* frequency
;
1654 return div64_u64(dividend
, divisor
);
1657 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1659 struct hw_perf_event
*hwc
= &event
->hw
;
1660 s64 period
, sample_period
;
1663 period
= perf_calculate_period(event
, nsec
, count
);
1665 delta
= (s64
)(period
- hwc
->sample_period
);
1666 delta
= (delta
+ 7) / 8; /* low pass filter */
1668 sample_period
= hwc
->sample_period
+ delta
;
1673 hwc
->sample_period
= sample_period
;
1675 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
1676 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
1677 local64_set(&hwc
->period_left
, 0);
1678 event
->pmu
->start(event
, PERF_EF_RELOAD
);
1682 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
, u64 period
)
1684 struct perf_event
*event
;
1685 struct hw_perf_event
*hwc
;
1686 u64 interrupts
, now
;
1689 raw_spin_lock(&ctx
->lock
);
1690 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
1691 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1694 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
1699 interrupts
= hwc
->interrupts
;
1700 hwc
->interrupts
= 0;
1703 * unthrottle events on the tick
1705 if (interrupts
== MAX_INTERRUPTS
) {
1706 perf_log_throttle(event
, 1);
1707 event
->pmu
->start(event
, 0);
1710 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
1713 event
->pmu
->read(event
);
1714 now
= local64_read(&event
->count
);
1715 delta
= now
- hwc
->freq_count_stamp
;
1716 hwc
->freq_count_stamp
= now
;
1719 perf_adjust_period(event
, period
, delta
);
1721 raw_spin_unlock(&ctx
->lock
);
1725 * Round-robin a context's events:
1727 static void rotate_ctx(struct perf_event_context
*ctx
)
1729 raw_spin_lock(&ctx
->lock
);
1732 * Rotate the first entry last of non-pinned groups. Rotation might be
1733 * disabled by the inheritance code.
1735 if (!ctx
->rotate_disable
)
1736 list_rotate_left(&ctx
->flexible_groups
);
1738 raw_spin_unlock(&ctx
->lock
);
1742 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
1743 * because they're strictly cpu affine and rotate_start is called with IRQs
1744 * disabled, while rotate_context is called from IRQ context.
1746 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
1748 u64 interval
= (u64
)cpuctx
->jiffies_interval
* TICK_NSEC
;
1749 struct perf_event_context
*ctx
= NULL
;
1750 int rotate
= 0, remove
= 1;
1752 if (cpuctx
->ctx
.nr_events
) {
1754 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
1758 ctx
= cpuctx
->task_ctx
;
1759 if (ctx
&& ctx
->nr_events
) {
1761 if (ctx
->nr_events
!= ctx
->nr_active
)
1765 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1766 perf_ctx_adjust_freq(&cpuctx
->ctx
, interval
);
1768 perf_ctx_adjust_freq(ctx
, interval
);
1773 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1775 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
1777 rotate_ctx(&cpuctx
->ctx
);
1781 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1783 task_ctx_sched_in(ctx
, EVENT_FLEXIBLE
);
1787 list_del_init(&cpuctx
->rotation_list
);
1789 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1792 void perf_event_task_tick(void)
1794 struct list_head
*head
= &__get_cpu_var(rotation_list
);
1795 struct perf_cpu_context
*cpuctx
, *tmp
;
1797 WARN_ON(!irqs_disabled());
1799 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
1800 if (cpuctx
->jiffies_interval
== 1 ||
1801 !(jiffies
% cpuctx
->jiffies_interval
))
1802 perf_rotate_context(cpuctx
);
1806 static int event_enable_on_exec(struct perf_event
*event
,
1807 struct perf_event_context
*ctx
)
1809 if (!event
->attr
.enable_on_exec
)
1812 event
->attr
.enable_on_exec
= 0;
1813 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1816 __perf_event_mark_enabled(event
, ctx
);
1822 * Enable all of a task's events that have been marked enable-on-exec.
1823 * This expects task == current.
1825 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
1827 struct perf_event
*event
;
1828 unsigned long flags
;
1832 local_irq_save(flags
);
1833 if (!ctx
|| !ctx
->nr_events
)
1836 task_ctx_sched_out(ctx
, EVENT_ALL
);
1838 raw_spin_lock(&ctx
->lock
);
1840 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1841 ret
= event_enable_on_exec(event
, ctx
);
1846 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1847 ret
= event_enable_on_exec(event
, ctx
);
1853 * Unclone this context if we enabled any event.
1858 raw_spin_unlock(&ctx
->lock
);
1860 perf_event_context_sched_in(ctx
);
1862 local_irq_restore(flags
);
1866 * Cross CPU call to read the hardware event
1868 static void __perf_event_read(void *info
)
1870 struct perf_event
*event
= info
;
1871 struct perf_event_context
*ctx
= event
->ctx
;
1872 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1875 * If this is a task context, we need to check whether it is
1876 * the current task context of this cpu. If not it has been
1877 * scheduled out before the smp call arrived. In that case
1878 * event->count would have been updated to a recent sample
1879 * when the event was scheduled out.
1881 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1884 raw_spin_lock(&ctx
->lock
);
1885 update_context_time(ctx
);
1886 update_event_times(event
);
1887 raw_spin_unlock(&ctx
->lock
);
1889 event
->pmu
->read(event
);
1892 static inline u64
perf_event_count(struct perf_event
*event
)
1894 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
1897 static u64
perf_event_read(struct perf_event
*event
)
1900 * If event is enabled and currently active on a CPU, update the
1901 * value in the event structure:
1903 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1904 smp_call_function_single(event
->oncpu
,
1905 __perf_event_read
, event
, 1);
1906 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1907 struct perf_event_context
*ctx
= event
->ctx
;
1908 unsigned long flags
;
1910 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1912 * may read while context is not active
1913 * (e.g., thread is blocked), in that case
1914 * we cannot update context time
1917 update_context_time(ctx
);
1918 update_event_times(event
);
1919 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1922 return perf_event_count(event
);
1929 struct callchain_cpus_entries
{
1930 struct rcu_head rcu_head
;
1931 struct perf_callchain_entry
*cpu_entries
[0];
1934 static DEFINE_PER_CPU(int, callchain_recursion
[PERF_NR_CONTEXTS
]);
1935 static atomic_t nr_callchain_events
;
1936 static DEFINE_MUTEX(callchain_mutex
);
1937 struct callchain_cpus_entries
*callchain_cpus_entries
;
1940 __weak
void perf_callchain_kernel(struct perf_callchain_entry
*entry
,
1941 struct pt_regs
*regs
)
1945 __weak
void perf_callchain_user(struct perf_callchain_entry
*entry
,
1946 struct pt_regs
*regs
)
1950 static void release_callchain_buffers_rcu(struct rcu_head
*head
)
1952 struct callchain_cpus_entries
*entries
;
1955 entries
= container_of(head
, struct callchain_cpus_entries
, rcu_head
);
1957 for_each_possible_cpu(cpu
)
1958 kfree(entries
->cpu_entries
[cpu
]);
1963 static void release_callchain_buffers(void)
1965 struct callchain_cpus_entries
*entries
;
1967 entries
= callchain_cpus_entries
;
1968 rcu_assign_pointer(callchain_cpus_entries
, NULL
);
1969 call_rcu(&entries
->rcu_head
, release_callchain_buffers_rcu
);
1972 static int alloc_callchain_buffers(void)
1976 struct callchain_cpus_entries
*entries
;
1979 * We can't use the percpu allocation API for data that can be
1980 * accessed from NMI. Use a temporary manual per cpu allocation
1981 * until that gets sorted out.
1983 size
= sizeof(*entries
) + sizeof(struct perf_callchain_entry
*) *
1984 num_possible_cpus();
1986 entries
= kzalloc(size
, GFP_KERNEL
);
1990 size
= sizeof(struct perf_callchain_entry
) * PERF_NR_CONTEXTS
;
1992 for_each_possible_cpu(cpu
) {
1993 entries
->cpu_entries
[cpu
] = kmalloc_node(size
, GFP_KERNEL
,
1995 if (!entries
->cpu_entries
[cpu
])
1999 rcu_assign_pointer(callchain_cpus_entries
, entries
);
2004 for_each_possible_cpu(cpu
)
2005 kfree(entries
->cpu_entries
[cpu
]);
2011 static int get_callchain_buffers(void)
2016 mutex_lock(&callchain_mutex
);
2018 count
= atomic_inc_return(&nr_callchain_events
);
2019 if (WARN_ON_ONCE(count
< 1)) {
2025 /* If the allocation failed, give up */
2026 if (!callchain_cpus_entries
)
2031 err
= alloc_callchain_buffers();
2033 release_callchain_buffers();
2035 mutex_unlock(&callchain_mutex
);
2040 static void put_callchain_buffers(void)
2042 if (atomic_dec_and_mutex_lock(&nr_callchain_events
, &callchain_mutex
)) {
2043 release_callchain_buffers();
2044 mutex_unlock(&callchain_mutex
);
2048 static int get_recursion_context(int *recursion
)
2056 else if (in_softirq())
2061 if (recursion
[rctx
])
2070 static inline void put_recursion_context(int *recursion
, int rctx
)
2076 static struct perf_callchain_entry
*get_callchain_entry(int *rctx
)
2079 struct callchain_cpus_entries
*entries
;
2081 *rctx
= get_recursion_context(__get_cpu_var(callchain_recursion
));
2085 entries
= rcu_dereference(callchain_cpus_entries
);
2089 cpu
= smp_processor_id();
2091 return &entries
->cpu_entries
[cpu
][*rctx
];
2095 put_callchain_entry(int rctx
)
2097 put_recursion_context(__get_cpu_var(callchain_recursion
), rctx
);
2100 static struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2103 struct perf_callchain_entry
*entry
;
2106 entry
= get_callchain_entry(&rctx
);
2115 if (!user_mode(regs
)) {
2116 perf_callchain_store(entry
, PERF_CONTEXT_KERNEL
);
2117 perf_callchain_kernel(entry
, regs
);
2119 regs
= task_pt_regs(current
);
2125 perf_callchain_store(entry
, PERF_CONTEXT_USER
);
2126 perf_callchain_user(entry
, regs
);
2130 put_callchain_entry(rctx
);
2136 * Initialize the perf_event context in a task_struct:
2138 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2140 raw_spin_lock_init(&ctx
->lock
);
2141 mutex_init(&ctx
->mutex
);
2142 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2143 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2144 INIT_LIST_HEAD(&ctx
->event_list
);
2145 atomic_set(&ctx
->refcount
, 1);
2148 static struct perf_event_context
*
2149 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2151 struct perf_event_context
*ctx
;
2153 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2157 __perf_event_init_context(ctx
);
2160 get_task_struct(task
);
2167 static struct task_struct
*
2168 find_lively_task_by_vpid(pid_t vpid
)
2170 struct task_struct
*task
;
2177 task
= find_task_by_vpid(vpid
);
2179 get_task_struct(task
);
2183 return ERR_PTR(-ESRCH
);
2186 * Can't attach events to a dying task.
2189 if (task
->flags
& PF_EXITING
)
2192 /* Reuse ptrace permission checks for now. */
2194 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2199 put_task_struct(task
);
2200 return ERR_PTR(err
);
2204 static struct perf_event_context
*
2205 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2207 struct perf_event_context
*ctx
;
2208 struct perf_cpu_context
*cpuctx
;
2209 unsigned long flags
;
2212 if (!task
&& cpu
!= -1) {
2213 /* Must be root to operate on a CPU event: */
2214 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2215 return ERR_PTR(-EACCES
);
2217 if (cpu
< 0 || cpu
>= nr_cpumask_bits
)
2218 return ERR_PTR(-EINVAL
);
2221 * We could be clever and allow to attach a event to an
2222 * offline CPU and activate it when the CPU comes up, but
2225 if (!cpu_online(cpu
))
2226 return ERR_PTR(-ENODEV
);
2228 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2236 ctxn
= pmu
->task_ctx_nr
;
2241 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2244 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2248 ctx
= alloc_perf_context(pmu
, task
);
2255 if (cmpxchg(&task
->perf_event_ctxp
[ctxn
], NULL
, ctx
)) {
2257 * We raced with some other task; use
2258 * the context they set.
2260 put_task_struct(task
);
2269 return ERR_PTR(err
);
2272 static void perf_event_free_filter(struct perf_event
*event
);
2274 static void free_event_rcu(struct rcu_head
*head
)
2276 struct perf_event
*event
;
2278 event
= container_of(head
, struct perf_event
, rcu_head
);
2280 put_pid_ns(event
->ns
);
2281 perf_event_free_filter(event
);
2285 static void perf_buffer_put(struct perf_buffer
*buffer
);
2287 static void free_event(struct perf_event
*event
)
2289 irq_work_sync(&event
->pending
);
2291 if (!event
->parent
) {
2292 if (event
->attach_state
& PERF_ATTACH_TASK
)
2293 jump_label_dec(&perf_task_events
);
2294 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2295 atomic_dec(&nr_mmap_events
);
2296 if (event
->attr
.comm
)
2297 atomic_dec(&nr_comm_events
);
2298 if (event
->attr
.task
)
2299 atomic_dec(&nr_task_events
);
2300 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2301 put_callchain_buffers();
2304 if (event
->buffer
) {
2305 perf_buffer_put(event
->buffer
);
2306 event
->buffer
= NULL
;
2310 event
->destroy(event
);
2313 put_ctx(event
->ctx
);
2315 call_rcu(&event
->rcu_head
, free_event_rcu
);
2318 int perf_event_release_kernel(struct perf_event
*event
)
2320 struct perf_event_context
*ctx
= event
->ctx
;
2323 * Remove from the PMU, can't get re-enabled since we got
2324 * here because the last ref went.
2326 perf_event_disable(event
);
2328 WARN_ON_ONCE(ctx
->parent_ctx
);
2330 * There are two ways this annotation is useful:
2332 * 1) there is a lock recursion from perf_event_exit_task
2333 * see the comment there.
2335 * 2) there is a lock-inversion with mmap_sem through
2336 * perf_event_read_group(), which takes faults while
2337 * holding ctx->mutex, however this is called after
2338 * the last filedesc died, so there is no possibility
2339 * to trigger the AB-BA case.
2341 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2342 raw_spin_lock_irq(&ctx
->lock
);
2343 perf_group_detach(event
);
2344 list_del_event(event
, ctx
);
2345 raw_spin_unlock_irq(&ctx
->lock
);
2346 mutex_unlock(&ctx
->mutex
);
2352 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2355 * Called when the last reference to the file is gone.
2357 static int perf_release(struct inode
*inode
, struct file
*file
)
2359 struct perf_event
*event
= file
->private_data
;
2360 struct task_struct
*owner
;
2362 file
->private_data
= NULL
;
2365 owner
= ACCESS_ONCE(event
->owner
);
2367 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2368 * !owner it means the list deletion is complete and we can indeed
2369 * free this event, otherwise we need to serialize on
2370 * owner->perf_event_mutex.
2372 smp_read_barrier_depends();
2375 * Since delayed_put_task_struct() also drops the last
2376 * task reference we can safely take a new reference
2377 * while holding the rcu_read_lock().
2379 get_task_struct(owner
);
2384 mutex_lock(&owner
->perf_event_mutex
);
2386 * We have to re-check the event->owner field, if it is cleared
2387 * we raced with perf_event_exit_task(), acquiring the mutex
2388 * ensured they're done, and we can proceed with freeing the
2392 list_del_init(&event
->owner_entry
);
2393 mutex_unlock(&owner
->perf_event_mutex
);
2394 put_task_struct(owner
);
2397 return perf_event_release_kernel(event
);
2400 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
2402 struct perf_event
*child
;
2408 mutex_lock(&event
->child_mutex
);
2409 total
+= perf_event_read(event
);
2410 *enabled
+= event
->total_time_enabled
+
2411 atomic64_read(&event
->child_total_time_enabled
);
2412 *running
+= event
->total_time_running
+
2413 atomic64_read(&event
->child_total_time_running
);
2415 list_for_each_entry(child
, &event
->child_list
, child_list
) {
2416 total
+= perf_event_read(child
);
2417 *enabled
+= child
->total_time_enabled
;
2418 *running
+= child
->total_time_running
;
2420 mutex_unlock(&event
->child_mutex
);
2424 EXPORT_SYMBOL_GPL(perf_event_read_value
);
2426 static int perf_event_read_group(struct perf_event
*event
,
2427 u64 read_format
, char __user
*buf
)
2429 struct perf_event
*leader
= event
->group_leader
, *sub
;
2430 int n
= 0, size
= 0, ret
= -EFAULT
;
2431 struct perf_event_context
*ctx
= leader
->ctx
;
2433 u64 count
, enabled
, running
;
2435 mutex_lock(&ctx
->mutex
);
2436 count
= perf_event_read_value(leader
, &enabled
, &running
);
2438 values
[n
++] = 1 + leader
->nr_siblings
;
2439 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2440 values
[n
++] = enabled
;
2441 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2442 values
[n
++] = running
;
2443 values
[n
++] = count
;
2444 if (read_format
& PERF_FORMAT_ID
)
2445 values
[n
++] = primary_event_id(leader
);
2447 size
= n
* sizeof(u64
);
2449 if (copy_to_user(buf
, values
, size
))
2454 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
2457 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
2458 if (read_format
& PERF_FORMAT_ID
)
2459 values
[n
++] = primary_event_id(sub
);
2461 size
= n
* sizeof(u64
);
2463 if (copy_to_user(buf
+ ret
, values
, size
)) {
2471 mutex_unlock(&ctx
->mutex
);
2476 static int perf_event_read_one(struct perf_event
*event
,
2477 u64 read_format
, char __user
*buf
)
2479 u64 enabled
, running
;
2483 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
2484 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2485 values
[n
++] = enabled
;
2486 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2487 values
[n
++] = running
;
2488 if (read_format
& PERF_FORMAT_ID
)
2489 values
[n
++] = primary_event_id(event
);
2491 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2494 return n
* sizeof(u64
);
2498 * Read the performance event - simple non blocking version for now
2501 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2503 u64 read_format
= event
->attr
.read_format
;
2507 * Return end-of-file for a read on a event that is in
2508 * error state (i.e. because it was pinned but it couldn't be
2509 * scheduled on to the CPU at some point).
2511 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2514 if (count
< event
->read_size
)
2517 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2518 if (read_format
& PERF_FORMAT_GROUP
)
2519 ret
= perf_event_read_group(event
, read_format
, buf
);
2521 ret
= perf_event_read_one(event
, read_format
, buf
);
2527 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2529 struct perf_event
*event
= file
->private_data
;
2531 return perf_read_hw(event
, buf
, count
);
2534 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2536 struct perf_event
*event
= file
->private_data
;
2537 struct perf_buffer
*buffer
;
2538 unsigned int events
= POLL_HUP
;
2541 buffer
= rcu_dereference(event
->buffer
);
2543 events
= atomic_xchg(&buffer
->poll
, 0);
2546 poll_wait(file
, &event
->waitq
, wait
);
2551 static void perf_event_reset(struct perf_event
*event
)
2553 (void)perf_event_read(event
);
2554 local64_set(&event
->count
, 0);
2555 perf_event_update_userpage(event
);
2559 * Holding the top-level event's child_mutex means that any
2560 * descendant process that has inherited this event will block
2561 * in sync_child_event if it goes to exit, thus satisfying the
2562 * task existence requirements of perf_event_enable/disable.
2564 static void perf_event_for_each_child(struct perf_event
*event
,
2565 void (*func
)(struct perf_event
*))
2567 struct perf_event
*child
;
2569 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2570 mutex_lock(&event
->child_mutex
);
2572 list_for_each_entry(child
, &event
->child_list
, child_list
)
2574 mutex_unlock(&event
->child_mutex
);
2577 static void perf_event_for_each(struct perf_event
*event
,
2578 void (*func
)(struct perf_event
*))
2580 struct perf_event_context
*ctx
= event
->ctx
;
2581 struct perf_event
*sibling
;
2583 WARN_ON_ONCE(ctx
->parent_ctx
);
2584 mutex_lock(&ctx
->mutex
);
2585 event
= event
->group_leader
;
2587 perf_event_for_each_child(event
, func
);
2589 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
2590 perf_event_for_each_child(event
, func
);
2591 mutex_unlock(&ctx
->mutex
);
2594 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
2596 struct perf_event_context
*ctx
= event
->ctx
;
2600 if (!is_sampling_event(event
))
2603 if (copy_from_user(&value
, arg
, sizeof(value
)))
2609 raw_spin_lock_irq(&ctx
->lock
);
2610 if (event
->attr
.freq
) {
2611 if (value
> sysctl_perf_event_sample_rate
) {
2616 event
->attr
.sample_freq
= value
;
2618 event
->attr
.sample_period
= value
;
2619 event
->hw
.sample_period
= value
;
2622 raw_spin_unlock_irq(&ctx
->lock
);
2627 static const struct file_operations perf_fops
;
2629 static struct perf_event
*perf_fget_light(int fd
, int *fput_needed
)
2633 file
= fget_light(fd
, fput_needed
);
2635 return ERR_PTR(-EBADF
);
2637 if (file
->f_op
!= &perf_fops
) {
2638 fput_light(file
, *fput_needed
);
2640 return ERR_PTR(-EBADF
);
2643 return file
->private_data
;
2646 static int perf_event_set_output(struct perf_event
*event
,
2647 struct perf_event
*output_event
);
2648 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
2650 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2652 struct perf_event
*event
= file
->private_data
;
2653 void (*func
)(struct perf_event
*);
2657 case PERF_EVENT_IOC_ENABLE
:
2658 func
= perf_event_enable
;
2660 case PERF_EVENT_IOC_DISABLE
:
2661 func
= perf_event_disable
;
2663 case PERF_EVENT_IOC_RESET
:
2664 func
= perf_event_reset
;
2667 case PERF_EVENT_IOC_REFRESH
:
2668 return perf_event_refresh(event
, arg
);
2670 case PERF_EVENT_IOC_PERIOD
:
2671 return perf_event_period(event
, (u64 __user
*)arg
);
2673 case PERF_EVENT_IOC_SET_OUTPUT
:
2675 struct perf_event
*output_event
= NULL
;
2676 int fput_needed
= 0;
2680 output_event
= perf_fget_light(arg
, &fput_needed
);
2681 if (IS_ERR(output_event
))
2682 return PTR_ERR(output_event
);
2685 ret
= perf_event_set_output(event
, output_event
);
2687 fput_light(output_event
->filp
, fput_needed
);
2692 case PERF_EVENT_IOC_SET_FILTER
:
2693 return perf_event_set_filter(event
, (void __user
*)arg
);
2699 if (flags
& PERF_IOC_FLAG_GROUP
)
2700 perf_event_for_each(event
, func
);
2702 perf_event_for_each_child(event
, func
);
2707 int perf_event_task_enable(void)
2709 struct perf_event
*event
;
2711 mutex_lock(¤t
->perf_event_mutex
);
2712 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2713 perf_event_for_each_child(event
, perf_event_enable
);
2714 mutex_unlock(¤t
->perf_event_mutex
);
2719 int perf_event_task_disable(void)
2721 struct perf_event
*event
;
2723 mutex_lock(¤t
->perf_event_mutex
);
2724 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2725 perf_event_for_each_child(event
, perf_event_disable
);
2726 mutex_unlock(¤t
->perf_event_mutex
);
2731 #ifndef PERF_EVENT_INDEX_OFFSET
2732 # define PERF_EVENT_INDEX_OFFSET 0
2735 static int perf_event_index(struct perf_event
*event
)
2737 if (event
->hw
.state
& PERF_HES_STOPPED
)
2740 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2743 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
2747 * Callers need to ensure there can be no nesting of this function, otherwise
2748 * the seqlock logic goes bad. We can not serialize this because the arch
2749 * code calls this from NMI context.
2751 void perf_event_update_userpage(struct perf_event
*event
)
2753 struct perf_event_mmap_page
*userpg
;
2754 struct perf_buffer
*buffer
;
2757 buffer
= rcu_dereference(event
->buffer
);
2761 userpg
= buffer
->user_page
;
2764 * Disable preemption so as to not let the corresponding user-space
2765 * spin too long if we get preempted.
2770 userpg
->index
= perf_event_index(event
);
2771 userpg
->offset
= perf_event_count(event
);
2772 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2773 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
2775 userpg
->time_enabled
= event
->total_time_enabled
+
2776 atomic64_read(&event
->child_total_time_enabled
);
2778 userpg
->time_running
= event
->total_time_running
+
2779 atomic64_read(&event
->child_total_time_running
);
2788 static unsigned long perf_data_size(struct perf_buffer
*buffer
);
2791 perf_buffer_init(struct perf_buffer
*buffer
, long watermark
, int flags
)
2793 long max_size
= perf_data_size(buffer
);
2796 buffer
->watermark
= min(max_size
, watermark
);
2798 if (!buffer
->watermark
)
2799 buffer
->watermark
= max_size
/ 2;
2801 if (flags
& PERF_BUFFER_WRITABLE
)
2802 buffer
->writable
= 1;
2804 atomic_set(&buffer
->refcount
, 1);
2807 #ifndef CONFIG_PERF_USE_VMALLOC
2810 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
2813 static struct page
*
2814 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
2816 if (pgoff
> buffer
->nr_pages
)
2820 return virt_to_page(buffer
->user_page
);
2822 return virt_to_page(buffer
->data_pages
[pgoff
- 1]);
2825 static void *perf_mmap_alloc_page(int cpu
)
2830 node
= (cpu
== -1) ? cpu
: cpu_to_node(cpu
);
2831 page
= alloc_pages_node(node
, GFP_KERNEL
| __GFP_ZERO
, 0);
2835 return page_address(page
);
2838 static struct perf_buffer
*
2839 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
2841 struct perf_buffer
*buffer
;
2845 size
= sizeof(struct perf_buffer
);
2846 size
+= nr_pages
* sizeof(void *);
2848 buffer
= kzalloc(size
, GFP_KERNEL
);
2852 buffer
->user_page
= perf_mmap_alloc_page(cpu
);
2853 if (!buffer
->user_page
)
2854 goto fail_user_page
;
2856 for (i
= 0; i
< nr_pages
; i
++) {
2857 buffer
->data_pages
[i
] = perf_mmap_alloc_page(cpu
);
2858 if (!buffer
->data_pages
[i
])
2859 goto fail_data_pages
;
2862 buffer
->nr_pages
= nr_pages
;
2864 perf_buffer_init(buffer
, watermark
, flags
);
2869 for (i
--; i
>= 0; i
--)
2870 free_page((unsigned long)buffer
->data_pages
[i
]);
2872 free_page((unsigned long)buffer
->user_page
);
2881 static void perf_mmap_free_page(unsigned long addr
)
2883 struct page
*page
= virt_to_page((void *)addr
);
2885 page
->mapping
= NULL
;
2889 static void perf_buffer_free(struct perf_buffer
*buffer
)
2893 perf_mmap_free_page((unsigned long)buffer
->user_page
);
2894 for (i
= 0; i
< buffer
->nr_pages
; i
++)
2895 perf_mmap_free_page((unsigned long)buffer
->data_pages
[i
]);
2899 static inline int page_order(struct perf_buffer
*buffer
)
2907 * Back perf_mmap() with vmalloc memory.
2909 * Required for architectures that have d-cache aliasing issues.
2912 static inline int page_order(struct perf_buffer
*buffer
)
2914 return buffer
->page_order
;
2917 static struct page
*
2918 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
2920 if (pgoff
> (1UL << page_order(buffer
)))
2923 return vmalloc_to_page((void *)buffer
->user_page
+ pgoff
* PAGE_SIZE
);
2926 static void perf_mmap_unmark_page(void *addr
)
2928 struct page
*page
= vmalloc_to_page(addr
);
2930 page
->mapping
= NULL
;
2933 static void perf_buffer_free_work(struct work_struct
*work
)
2935 struct perf_buffer
*buffer
;
2939 buffer
= container_of(work
, struct perf_buffer
, work
);
2940 nr
= 1 << page_order(buffer
);
2942 base
= buffer
->user_page
;
2943 for (i
= 0; i
< nr
+ 1; i
++)
2944 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
2950 static void perf_buffer_free(struct perf_buffer
*buffer
)
2952 schedule_work(&buffer
->work
);
2955 static struct perf_buffer
*
2956 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
2958 struct perf_buffer
*buffer
;
2962 size
= sizeof(struct perf_buffer
);
2963 size
+= sizeof(void *);
2965 buffer
= kzalloc(size
, GFP_KERNEL
);
2969 INIT_WORK(&buffer
->work
, perf_buffer_free_work
);
2971 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
2975 buffer
->user_page
= all_buf
;
2976 buffer
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
2977 buffer
->page_order
= ilog2(nr_pages
);
2978 buffer
->nr_pages
= 1;
2980 perf_buffer_init(buffer
, watermark
, flags
);
2993 static unsigned long perf_data_size(struct perf_buffer
*buffer
)
2995 return buffer
->nr_pages
<< (PAGE_SHIFT
+ page_order(buffer
));
2998 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3000 struct perf_event
*event
= vma
->vm_file
->private_data
;
3001 struct perf_buffer
*buffer
;
3002 int ret
= VM_FAULT_SIGBUS
;
3004 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3005 if (vmf
->pgoff
== 0)
3011 buffer
= rcu_dereference(event
->buffer
);
3015 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3018 vmf
->page
= perf_mmap_to_page(buffer
, vmf
->pgoff
);
3022 get_page(vmf
->page
);
3023 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3024 vmf
->page
->index
= vmf
->pgoff
;
3033 static void perf_buffer_free_rcu(struct rcu_head
*rcu_head
)
3035 struct perf_buffer
*buffer
;
3037 buffer
= container_of(rcu_head
, struct perf_buffer
, rcu_head
);
3038 perf_buffer_free(buffer
);
3041 static struct perf_buffer
*perf_buffer_get(struct perf_event
*event
)
3043 struct perf_buffer
*buffer
;
3046 buffer
= rcu_dereference(event
->buffer
);
3048 if (!atomic_inc_not_zero(&buffer
->refcount
))
3056 static void perf_buffer_put(struct perf_buffer
*buffer
)
3058 if (!atomic_dec_and_test(&buffer
->refcount
))
3061 call_rcu(&buffer
->rcu_head
, perf_buffer_free_rcu
);
3064 static void perf_mmap_open(struct vm_area_struct
*vma
)
3066 struct perf_event
*event
= vma
->vm_file
->private_data
;
3068 atomic_inc(&event
->mmap_count
);
3071 static void perf_mmap_close(struct vm_area_struct
*vma
)
3073 struct perf_event
*event
= vma
->vm_file
->private_data
;
3075 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3076 unsigned long size
= perf_data_size(event
->buffer
);
3077 struct user_struct
*user
= event
->mmap_user
;
3078 struct perf_buffer
*buffer
= event
->buffer
;
3080 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3081 vma
->vm_mm
->locked_vm
-= event
->mmap_locked
;
3082 rcu_assign_pointer(event
->buffer
, NULL
);
3083 mutex_unlock(&event
->mmap_mutex
);
3085 perf_buffer_put(buffer
);
3090 static const struct vm_operations_struct perf_mmap_vmops
= {
3091 .open
= perf_mmap_open
,
3092 .close
= perf_mmap_close
,
3093 .fault
= perf_mmap_fault
,
3094 .page_mkwrite
= perf_mmap_fault
,
3097 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3099 struct perf_event
*event
= file
->private_data
;
3100 unsigned long user_locked
, user_lock_limit
;
3101 struct user_struct
*user
= current_user();
3102 unsigned long locked
, lock_limit
;
3103 struct perf_buffer
*buffer
;
3104 unsigned long vma_size
;
3105 unsigned long nr_pages
;
3106 long user_extra
, extra
;
3107 int ret
= 0, flags
= 0;
3110 * Don't allow mmap() of inherited per-task counters. This would
3111 * create a performance issue due to all children writing to the
3114 if (event
->cpu
== -1 && event
->attr
.inherit
)
3117 if (!(vma
->vm_flags
& VM_SHARED
))
3120 vma_size
= vma
->vm_end
- vma
->vm_start
;
3121 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3124 * If we have buffer pages ensure they're a power-of-two number, so we
3125 * can do bitmasks instead of modulo.
3127 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3130 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3133 if (vma
->vm_pgoff
!= 0)
3136 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3137 mutex_lock(&event
->mmap_mutex
);
3138 if (event
->buffer
) {
3139 if (event
->buffer
->nr_pages
== nr_pages
)
3140 atomic_inc(&event
->buffer
->refcount
);
3146 user_extra
= nr_pages
+ 1;
3147 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3150 * Increase the limit linearly with more CPUs:
3152 user_lock_limit
*= num_online_cpus();
3154 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3157 if (user_locked
> user_lock_limit
)
3158 extra
= user_locked
- user_lock_limit
;
3160 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3161 lock_limit
>>= PAGE_SHIFT
;
3162 locked
= vma
->vm_mm
->locked_vm
+ extra
;
3164 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3165 !capable(CAP_IPC_LOCK
)) {
3170 WARN_ON(event
->buffer
);
3172 if (vma
->vm_flags
& VM_WRITE
)
3173 flags
|= PERF_BUFFER_WRITABLE
;
3175 buffer
= perf_buffer_alloc(nr_pages
, event
->attr
.wakeup_watermark
,
3181 rcu_assign_pointer(event
->buffer
, buffer
);
3183 atomic_long_add(user_extra
, &user
->locked_vm
);
3184 event
->mmap_locked
= extra
;
3185 event
->mmap_user
= get_current_user();
3186 vma
->vm_mm
->locked_vm
+= event
->mmap_locked
;
3190 atomic_inc(&event
->mmap_count
);
3191 mutex_unlock(&event
->mmap_mutex
);
3193 vma
->vm_flags
|= VM_RESERVED
;
3194 vma
->vm_ops
= &perf_mmap_vmops
;
3199 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3201 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3202 struct perf_event
*event
= filp
->private_data
;
3205 mutex_lock(&inode
->i_mutex
);
3206 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3207 mutex_unlock(&inode
->i_mutex
);
3215 static const struct file_operations perf_fops
= {
3216 .llseek
= no_llseek
,
3217 .release
= perf_release
,
3220 .unlocked_ioctl
= perf_ioctl
,
3221 .compat_ioctl
= perf_ioctl
,
3223 .fasync
= perf_fasync
,
3229 * If there's data, ensure we set the poll() state and publish everything
3230 * to user-space before waking everybody up.
3233 void perf_event_wakeup(struct perf_event
*event
)
3235 wake_up_all(&event
->waitq
);
3237 if (event
->pending_kill
) {
3238 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3239 event
->pending_kill
= 0;
3243 static void perf_pending_event(struct irq_work
*entry
)
3245 struct perf_event
*event
= container_of(entry
,
3246 struct perf_event
, pending
);
3248 if (event
->pending_disable
) {
3249 event
->pending_disable
= 0;
3250 __perf_event_disable(event
);
3253 if (event
->pending_wakeup
) {
3254 event
->pending_wakeup
= 0;
3255 perf_event_wakeup(event
);
3260 * We assume there is only KVM supporting the callbacks.
3261 * Later on, we might change it to a list if there is
3262 * another virtualization implementation supporting the callbacks.
3264 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3266 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3268 perf_guest_cbs
= cbs
;
3271 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3273 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3275 perf_guest_cbs
= NULL
;
3278 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3283 static bool perf_output_space(struct perf_buffer
*buffer
, unsigned long tail
,
3284 unsigned long offset
, unsigned long head
)
3288 if (!buffer
->writable
)
3291 mask
= perf_data_size(buffer
) - 1;
3293 offset
= (offset
- tail
) & mask
;
3294 head
= (head
- tail
) & mask
;
3296 if ((int)(head
- offset
) < 0)
3302 static void perf_output_wakeup(struct perf_output_handle
*handle
)
3304 atomic_set(&handle
->buffer
->poll
, POLL_IN
);
3307 handle
->event
->pending_wakeup
= 1;
3308 irq_work_queue(&handle
->event
->pending
);
3310 perf_event_wakeup(handle
->event
);
3314 * We need to ensure a later event_id doesn't publish a head when a former
3315 * event isn't done writing. However since we need to deal with NMIs we
3316 * cannot fully serialize things.
3318 * We only publish the head (and generate a wakeup) when the outer-most
3321 static void perf_output_get_handle(struct perf_output_handle
*handle
)
3323 struct perf_buffer
*buffer
= handle
->buffer
;
3326 local_inc(&buffer
->nest
);
3327 handle
->wakeup
= local_read(&buffer
->wakeup
);
3330 static void perf_output_put_handle(struct perf_output_handle
*handle
)
3332 struct perf_buffer
*buffer
= handle
->buffer
;
3336 head
= local_read(&buffer
->head
);
3339 * IRQ/NMI can happen here, which means we can miss a head update.
3342 if (!local_dec_and_test(&buffer
->nest
))
3346 * Publish the known good head. Rely on the full barrier implied
3347 * by atomic_dec_and_test() order the buffer->head read and this
3350 buffer
->user_page
->data_head
= head
;
3353 * Now check if we missed an update, rely on the (compiler)
3354 * barrier in atomic_dec_and_test() to re-read buffer->head.
3356 if (unlikely(head
!= local_read(&buffer
->head
))) {
3357 local_inc(&buffer
->nest
);
3361 if (handle
->wakeup
!= local_read(&buffer
->wakeup
))
3362 perf_output_wakeup(handle
);
3368 __always_inline
void perf_output_copy(struct perf_output_handle
*handle
,
3369 const void *buf
, unsigned int len
)
3372 unsigned long size
= min_t(unsigned long, handle
->size
, len
);
3374 memcpy(handle
->addr
, buf
, size
);
3377 handle
->addr
+= size
;
3379 handle
->size
-= size
;
3380 if (!handle
->size
) {
3381 struct perf_buffer
*buffer
= handle
->buffer
;
3384 handle
->page
&= buffer
->nr_pages
- 1;
3385 handle
->addr
= buffer
->data_pages
[handle
->page
];
3386 handle
->size
= PAGE_SIZE
<< page_order(buffer
);
3391 static void perf_event_header__init_id(struct perf_event_header
*header
,
3392 struct perf_sample_data
*data
,
3393 struct perf_event
*event
)
3395 u64 sample_type
= event
->attr
.sample_type
;
3397 data
->type
= sample_type
;
3398 header
->size
+= event
->id_header_size
;
3400 if (sample_type
& PERF_SAMPLE_TID
) {
3401 /* namespace issues */
3402 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3403 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3406 if (sample_type
& PERF_SAMPLE_TIME
)
3407 data
->time
= perf_clock();
3409 if (sample_type
& PERF_SAMPLE_ID
)
3410 data
->id
= primary_event_id(event
);
3412 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3413 data
->stream_id
= event
->id
;
3415 if (sample_type
& PERF_SAMPLE_CPU
) {
3416 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3417 data
->cpu_entry
.reserved
= 0;
3421 int perf_output_begin(struct perf_output_handle
*handle
,
3422 struct perf_event
*event
, unsigned int size
,
3423 int nmi
, int sample
)
3425 struct perf_buffer
*buffer
;
3426 unsigned long tail
, offset
, head
;
3429 struct perf_event_header header
;
3436 * For inherited events we send all the output towards the parent.
3439 event
= event
->parent
;
3441 buffer
= rcu_dereference(event
->buffer
);
3445 handle
->buffer
= buffer
;
3446 handle
->event
= event
;
3448 handle
->sample
= sample
;
3450 if (!buffer
->nr_pages
)
3453 have_lost
= local_read(&buffer
->lost
);
3455 size
+= sizeof(lost_event
);
3457 perf_output_get_handle(handle
);
3461 * Userspace could choose to issue a mb() before updating the
3462 * tail pointer. So that all reads will be completed before the
3465 tail
= ACCESS_ONCE(buffer
->user_page
->data_tail
);
3467 offset
= head
= local_read(&buffer
->head
);
3469 if (unlikely(!perf_output_space(buffer
, tail
, offset
, head
)))
3471 } while (local_cmpxchg(&buffer
->head
, offset
, head
) != offset
);
3473 if (head
- local_read(&buffer
->wakeup
) > buffer
->watermark
)
3474 local_add(buffer
->watermark
, &buffer
->wakeup
);
3476 handle
->page
= offset
>> (PAGE_SHIFT
+ page_order(buffer
));
3477 handle
->page
&= buffer
->nr_pages
- 1;
3478 handle
->size
= offset
& ((PAGE_SIZE
<< page_order(buffer
)) - 1);
3479 handle
->addr
= buffer
->data_pages
[handle
->page
];
3480 handle
->addr
+= handle
->size
;
3481 handle
->size
= (PAGE_SIZE
<< page_order(buffer
)) - handle
->size
;
3484 lost_event
.header
.type
= PERF_RECORD_LOST
;
3485 lost_event
.header
.misc
= 0;
3486 lost_event
.header
.size
= sizeof(lost_event
);
3487 lost_event
.id
= event
->id
;
3488 lost_event
.lost
= local_xchg(&buffer
->lost
, 0);
3490 perf_output_put(handle
, lost_event
);
3496 local_inc(&buffer
->lost
);
3497 perf_output_put_handle(handle
);
3504 void perf_output_end(struct perf_output_handle
*handle
)
3506 struct perf_event
*event
= handle
->event
;
3507 struct perf_buffer
*buffer
= handle
->buffer
;
3509 int wakeup_events
= event
->attr
.wakeup_events
;
3511 if (handle
->sample
&& wakeup_events
) {
3512 int events
= local_inc_return(&buffer
->events
);
3513 if (events
>= wakeup_events
) {
3514 local_sub(wakeup_events
, &buffer
->events
);
3515 local_inc(&buffer
->wakeup
);
3519 perf_output_put_handle(handle
);
3523 static void perf_output_read_one(struct perf_output_handle
*handle
,
3524 struct perf_event
*event
,
3525 u64 enabled
, u64 running
)
3527 u64 read_format
= event
->attr
.read_format
;
3531 values
[n
++] = perf_event_count(event
);
3532 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3533 values
[n
++] = enabled
+
3534 atomic64_read(&event
->child_total_time_enabled
);
3536 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3537 values
[n
++] = running
+
3538 atomic64_read(&event
->child_total_time_running
);
3540 if (read_format
& PERF_FORMAT_ID
)
3541 values
[n
++] = primary_event_id(event
);
3543 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3547 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3549 static void perf_output_read_group(struct perf_output_handle
*handle
,
3550 struct perf_event
*event
,
3551 u64 enabled
, u64 running
)
3553 struct perf_event
*leader
= event
->group_leader
, *sub
;
3554 u64 read_format
= event
->attr
.read_format
;
3558 values
[n
++] = 1 + leader
->nr_siblings
;
3560 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3561 values
[n
++] = enabled
;
3563 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3564 values
[n
++] = running
;
3566 if (leader
!= event
)
3567 leader
->pmu
->read(leader
);
3569 values
[n
++] = perf_event_count(leader
);
3570 if (read_format
& PERF_FORMAT_ID
)
3571 values
[n
++] = primary_event_id(leader
);
3573 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3575 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3579 sub
->pmu
->read(sub
);
3581 values
[n
++] = perf_event_count(sub
);
3582 if (read_format
& PERF_FORMAT_ID
)
3583 values
[n
++] = primary_event_id(sub
);
3585 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3589 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
3590 PERF_FORMAT_TOTAL_TIME_RUNNING)
3592 static void perf_output_read(struct perf_output_handle
*handle
,
3593 struct perf_event
*event
)
3595 u64 enabled
= 0, running
= 0, now
, ctx_time
;
3596 u64 read_format
= event
->attr
.read_format
;
3599 * compute total_time_enabled, total_time_running
3600 * based on snapshot values taken when the event
3601 * was last scheduled in.
3603 * we cannot simply called update_context_time()
3604 * because of locking issue as we are called in
3607 if (read_format
& PERF_FORMAT_TOTAL_TIMES
) {
3609 ctx_time
= event
->shadow_ctx_time
+ now
;
3610 enabled
= ctx_time
- event
->tstamp_enabled
;
3611 running
= ctx_time
- event
->tstamp_running
;
3614 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3615 perf_output_read_group(handle
, event
, enabled
, running
);
3617 perf_output_read_one(handle
, event
, enabled
, running
);
3620 void perf_output_sample(struct perf_output_handle
*handle
,
3621 struct perf_event_header
*header
,
3622 struct perf_sample_data
*data
,
3623 struct perf_event
*event
)
3625 u64 sample_type
= data
->type
;
3627 perf_output_put(handle
, *header
);
3629 if (sample_type
& PERF_SAMPLE_IP
)
3630 perf_output_put(handle
, data
->ip
);
3632 if (sample_type
& PERF_SAMPLE_TID
)
3633 perf_output_put(handle
, data
->tid_entry
);
3635 if (sample_type
& PERF_SAMPLE_TIME
)
3636 perf_output_put(handle
, data
->time
);
3638 if (sample_type
& PERF_SAMPLE_ADDR
)
3639 perf_output_put(handle
, data
->addr
);
3641 if (sample_type
& PERF_SAMPLE_ID
)
3642 perf_output_put(handle
, data
->id
);
3644 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3645 perf_output_put(handle
, data
->stream_id
);
3647 if (sample_type
& PERF_SAMPLE_CPU
)
3648 perf_output_put(handle
, data
->cpu_entry
);
3650 if (sample_type
& PERF_SAMPLE_PERIOD
)
3651 perf_output_put(handle
, data
->period
);
3653 if (sample_type
& PERF_SAMPLE_READ
)
3654 perf_output_read(handle
, event
);
3656 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3657 if (data
->callchain
) {
3660 if (data
->callchain
)
3661 size
+= data
->callchain
->nr
;
3663 size
*= sizeof(u64
);
3665 perf_output_copy(handle
, data
->callchain
, size
);
3668 perf_output_put(handle
, nr
);
3672 if (sample_type
& PERF_SAMPLE_RAW
) {
3674 perf_output_put(handle
, data
->raw
->size
);
3675 perf_output_copy(handle
, data
->raw
->data
,
3682 .size
= sizeof(u32
),
3685 perf_output_put(handle
, raw
);
3690 void perf_prepare_sample(struct perf_event_header
*header
,
3691 struct perf_sample_data
*data
,
3692 struct perf_event
*event
,
3693 struct pt_regs
*regs
)
3695 u64 sample_type
= event
->attr
.sample_type
;
3697 header
->type
= PERF_RECORD_SAMPLE
;
3698 header
->size
= sizeof(*header
) + event
->header_size
;
3701 header
->misc
|= perf_misc_flags(regs
);
3703 perf_event_header__init_id(header
, data
, event
);
3705 if (sample_type
& PERF_SAMPLE_IP
)
3706 data
->ip
= perf_instruction_pointer(regs
);
3708 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3711 data
->callchain
= perf_callchain(regs
);
3713 if (data
->callchain
)
3714 size
+= data
->callchain
->nr
;
3716 header
->size
+= size
* sizeof(u64
);
3719 if (sample_type
& PERF_SAMPLE_RAW
) {
3720 int size
= sizeof(u32
);
3723 size
+= data
->raw
->size
;
3725 size
+= sizeof(u32
);
3727 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3728 header
->size
+= size
;
3732 static void perf_event_output(struct perf_event
*event
, int nmi
,
3733 struct perf_sample_data
*data
,
3734 struct pt_regs
*regs
)
3736 struct perf_output_handle handle
;
3737 struct perf_event_header header
;
3739 /* protect the callchain buffers */
3742 perf_prepare_sample(&header
, data
, event
, regs
);
3744 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
3747 perf_output_sample(&handle
, &header
, data
, event
);
3749 perf_output_end(&handle
);
3759 struct perf_read_event
{
3760 struct perf_event_header header
;
3767 perf_event_read_event(struct perf_event
*event
,
3768 struct task_struct
*task
)
3770 struct perf_output_handle handle
;
3771 struct perf_read_event read_event
= {
3773 .type
= PERF_RECORD_READ
,
3775 .size
= sizeof(read_event
) + event
->read_size
,
3777 .pid
= perf_event_pid(event
, task
),
3778 .tid
= perf_event_tid(event
, task
),
3782 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
3786 perf_output_put(&handle
, read_event
);
3787 perf_output_read(&handle
, event
);
3789 perf_output_end(&handle
);
3793 * task tracking -- fork/exit
3795 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
3798 struct perf_task_event
{
3799 struct task_struct
*task
;
3800 struct perf_event_context
*task_ctx
;
3803 struct perf_event_header header
;
3813 static void perf_event_task_output(struct perf_event
*event
,
3814 struct perf_task_event
*task_event
)
3816 struct perf_output_handle handle
;
3817 struct task_struct
*task
= task_event
->task
;
3820 size
= task_event
->event_id
.header
.size
;
3821 ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3826 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
3827 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
3829 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
3830 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
3832 perf_output_put(&handle
, task_event
->event_id
);
3834 perf_output_end(&handle
);
3837 static int perf_event_task_match(struct perf_event
*event
)
3839 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3842 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3845 if (event
->attr
.comm
|| event
->attr
.mmap
||
3846 event
->attr
.mmap_data
|| event
->attr
.task
)
3852 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
3853 struct perf_task_event
*task_event
)
3855 struct perf_event
*event
;
3857 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3858 if (perf_event_task_match(event
))
3859 perf_event_task_output(event
, task_event
);
3863 static void perf_event_task_event(struct perf_task_event
*task_event
)
3865 struct perf_cpu_context
*cpuctx
;
3866 struct perf_event_context
*ctx
;
3871 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
3872 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
3873 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
3875 ctx
= task_event
->task_ctx
;
3877 ctxn
= pmu
->task_ctx_nr
;
3880 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
3883 perf_event_task_ctx(ctx
, task_event
);
3885 put_cpu_ptr(pmu
->pmu_cpu_context
);
3890 static void perf_event_task(struct task_struct
*task
,
3891 struct perf_event_context
*task_ctx
,
3894 struct perf_task_event task_event
;
3896 if (!atomic_read(&nr_comm_events
) &&
3897 !atomic_read(&nr_mmap_events
) &&
3898 !atomic_read(&nr_task_events
))
3901 task_event
= (struct perf_task_event
){
3903 .task_ctx
= task_ctx
,
3906 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
3908 .size
= sizeof(task_event
.event_id
),
3914 .time
= perf_clock(),
3918 perf_event_task_event(&task_event
);
3921 void perf_event_fork(struct task_struct
*task
)
3923 perf_event_task(task
, NULL
, 1);
3930 struct perf_comm_event
{
3931 struct task_struct
*task
;
3936 struct perf_event_header header
;
3943 static void perf_event_comm_output(struct perf_event
*event
,
3944 struct perf_comm_event
*comm_event
)
3946 struct perf_output_handle handle
;
3947 int size
= comm_event
->event_id
.header
.size
;
3948 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
3953 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
3954 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
3956 perf_output_put(&handle
, comm_event
->event_id
);
3957 perf_output_copy(&handle
, comm_event
->comm
,
3958 comm_event
->comm_size
);
3959 perf_output_end(&handle
);
3962 static int perf_event_comm_match(struct perf_event
*event
)
3964 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3967 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
3970 if (event
->attr
.comm
)
3976 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
3977 struct perf_comm_event
*comm_event
)
3979 struct perf_event
*event
;
3981 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3982 if (perf_event_comm_match(event
))
3983 perf_event_comm_output(event
, comm_event
);
3987 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
3989 struct perf_cpu_context
*cpuctx
;
3990 struct perf_event_context
*ctx
;
3991 char comm
[TASK_COMM_LEN
];
3996 memset(comm
, 0, sizeof(comm
));
3997 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
3998 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4000 comm_event
->comm
= comm
;
4001 comm_event
->comm_size
= size
;
4003 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4006 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4007 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4008 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4010 ctxn
= pmu
->task_ctx_nr
;
4014 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4016 perf_event_comm_ctx(ctx
, comm_event
);
4018 put_cpu_ptr(pmu
->pmu_cpu_context
);
4023 void perf_event_comm(struct task_struct
*task
)
4025 struct perf_comm_event comm_event
;
4026 struct perf_event_context
*ctx
;
4029 for_each_task_context_nr(ctxn
) {
4030 ctx
= task
->perf_event_ctxp
[ctxn
];
4034 perf_event_enable_on_exec(ctx
);
4037 if (!atomic_read(&nr_comm_events
))
4040 comm_event
= (struct perf_comm_event
){
4046 .type
= PERF_RECORD_COMM
,
4055 perf_event_comm_event(&comm_event
);
4062 struct perf_mmap_event
{
4063 struct vm_area_struct
*vma
;
4065 const char *file_name
;
4069 struct perf_event_header header
;
4079 static void perf_event_mmap_output(struct perf_event
*event
,
4080 struct perf_mmap_event
*mmap_event
)
4082 struct perf_output_handle handle
;
4083 int size
= mmap_event
->event_id
.header
.size
;
4084 int ret
= perf_output_begin(&handle
, event
, size
, 0, 0);
4089 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4090 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4092 perf_output_put(&handle
, mmap_event
->event_id
);
4093 perf_output_copy(&handle
, mmap_event
->file_name
,
4094 mmap_event
->file_size
);
4095 perf_output_end(&handle
);
4098 static int perf_event_mmap_match(struct perf_event
*event
,
4099 struct perf_mmap_event
*mmap_event
,
4102 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4105 if (event
->cpu
!= -1 && event
->cpu
!= smp_processor_id())
4108 if ((!executable
&& event
->attr
.mmap_data
) ||
4109 (executable
&& event
->attr
.mmap
))
4115 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4116 struct perf_mmap_event
*mmap_event
,
4119 struct perf_event
*event
;
4121 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4122 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4123 perf_event_mmap_output(event
, mmap_event
);
4127 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4129 struct perf_cpu_context
*cpuctx
;
4130 struct perf_event_context
*ctx
;
4131 struct vm_area_struct
*vma
= mmap_event
->vma
;
4132 struct file
*file
= vma
->vm_file
;
4140 memset(tmp
, 0, sizeof(tmp
));
4144 * d_path works from the end of the buffer backwards, so we
4145 * need to add enough zero bytes after the string to handle
4146 * the 64bit alignment we do later.
4148 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4150 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4153 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4155 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4159 if (arch_vma_name(mmap_event
->vma
)) {
4160 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4166 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4168 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4169 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4170 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4172 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4173 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4174 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4178 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4183 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4185 mmap_event
->file_name
= name
;
4186 mmap_event
->file_size
= size
;
4188 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4191 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4192 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4193 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4194 vma
->vm_flags
& VM_EXEC
);
4196 ctxn
= pmu
->task_ctx_nr
;
4200 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4202 perf_event_mmap_ctx(ctx
, mmap_event
,
4203 vma
->vm_flags
& VM_EXEC
);
4206 put_cpu_ptr(pmu
->pmu_cpu_context
);
4213 void perf_event_mmap(struct vm_area_struct
*vma
)
4215 struct perf_mmap_event mmap_event
;
4217 if (!atomic_read(&nr_mmap_events
))
4220 mmap_event
= (struct perf_mmap_event
){
4226 .type
= PERF_RECORD_MMAP
,
4227 .misc
= PERF_RECORD_MISC_USER
,
4232 .start
= vma
->vm_start
,
4233 .len
= vma
->vm_end
- vma
->vm_start
,
4234 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4238 perf_event_mmap_event(&mmap_event
);
4242 * IRQ throttle logging
4245 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4247 struct perf_output_handle handle
;
4251 struct perf_event_header header
;
4255 } throttle_event
= {
4257 .type
= PERF_RECORD_THROTTLE
,
4259 .size
= sizeof(throttle_event
),
4261 .time
= perf_clock(),
4262 .id
= primary_event_id(event
),
4263 .stream_id
= event
->id
,
4267 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4269 ret
= perf_output_begin(&handle
, event
, sizeof(throttle_event
), 1, 0);
4273 perf_output_put(&handle
, throttle_event
);
4274 perf_output_end(&handle
);
4278 * Generic event overflow handling, sampling.
4281 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
4282 int throttle
, struct perf_sample_data
*data
,
4283 struct pt_regs
*regs
)
4285 int events
= atomic_read(&event
->event_limit
);
4286 struct hw_perf_event
*hwc
= &event
->hw
;
4290 * Non-sampling counters might still use the PMI to fold short
4291 * hardware counters, ignore those.
4293 if (unlikely(!is_sampling_event(event
)))
4299 if (hwc
->interrupts
!= MAX_INTERRUPTS
) {
4301 if (HZ
* hwc
->interrupts
>
4302 (u64
)sysctl_perf_event_sample_rate
) {
4303 hwc
->interrupts
= MAX_INTERRUPTS
;
4304 perf_log_throttle(event
, 0);
4309 * Keep re-disabling events even though on the previous
4310 * pass we disabled it - just in case we raced with a
4311 * sched-in and the event got enabled again:
4317 if (event
->attr
.freq
) {
4318 u64 now
= perf_clock();
4319 s64 delta
= now
- hwc
->freq_time_stamp
;
4321 hwc
->freq_time_stamp
= now
;
4323 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4324 perf_adjust_period(event
, delta
, hwc
->last_period
);
4328 * XXX event_limit might not quite work as expected on inherited
4332 event
->pending_kill
= POLL_IN
;
4333 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4335 event
->pending_kill
= POLL_HUP
;
4337 event
->pending_disable
= 1;
4338 irq_work_queue(&event
->pending
);
4340 perf_event_disable(event
);
4343 if (event
->overflow_handler
)
4344 event
->overflow_handler(event
, nmi
, data
, regs
);
4346 perf_event_output(event
, nmi
, data
, regs
);
4351 int perf_event_overflow(struct perf_event
*event
, int nmi
,
4352 struct perf_sample_data
*data
,
4353 struct pt_regs
*regs
)
4355 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
4359 * Generic software event infrastructure
4362 struct swevent_htable
{
4363 struct swevent_hlist
*swevent_hlist
;
4364 struct mutex hlist_mutex
;
4367 /* Recursion avoidance in each contexts */
4368 int recursion
[PERF_NR_CONTEXTS
];
4371 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
4374 * We directly increment event->count and keep a second value in
4375 * event->hw.period_left to count intervals. This period event
4376 * is kept in the range [-sample_period, 0] so that we can use the
4380 static u64
perf_swevent_set_period(struct perf_event
*event
)
4382 struct hw_perf_event
*hwc
= &event
->hw
;
4383 u64 period
= hwc
->last_period
;
4387 hwc
->last_period
= hwc
->sample_period
;
4390 old
= val
= local64_read(&hwc
->period_left
);
4394 nr
= div64_u64(period
+ val
, period
);
4395 offset
= nr
* period
;
4397 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
4403 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
4404 int nmi
, struct perf_sample_data
*data
,
4405 struct pt_regs
*regs
)
4407 struct hw_perf_event
*hwc
= &event
->hw
;
4410 data
->period
= event
->hw
.last_period
;
4412 overflow
= perf_swevent_set_period(event
);
4414 if (hwc
->interrupts
== MAX_INTERRUPTS
)
4417 for (; overflow
; overflow
--) {
4418 if (__perf_event_overflow(event
, nmi
, throttle
,
4421 * We inhibit the overflow from happening when
4422 * hwc->interrupts == MAX_INTERRUPTS.
4430 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
4431 int nmi
, struct perf_sample_data
*data
,
4432 struct pt_regs
*regs
)
4434 struct hw_perf_event
*hwc
= &event
->hw
;
4436 local64_add(nr
, &event
->count
);
4441 if (!is_sampling_event(event
))
4444 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
4445 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
4447 if (local64_add_negative(nr
, &hwc
->period_left
))
4450 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
4453 static int perf_exclude_event(struct perf_event
*event
,
4454 struct pt_regs
*regs
)
4456 if (event
->hw
.state
& PERF_HES_STOPPED
)
4460 if (event
->attr
.exclude_user
&& user_mode(regs
))
4463 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4470 static int perf_swevent_match(struct perf_event
*event
,
4471 enum perf_type_id type
,
4473 struct perf_sample_data
*data
,
4474 struct pt_regs
*regs
)
4476 if (event
->attr
.type
!= type
)
4479 if (event
->attr
.config
!= event_id
)
4482 if (perf_exclude_event(event
, regs
))
4488 static inline u64
swevent_hash(u64 type
, u32 event_id
)
4490 u64 val
= event_id
| (type
<< 32);
4492 return hash_64(val
, SWEVENT_HLIST_BITS
);
4495 static inline struct hlist_head
*
4496 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
4498 u64 hash
= swevent_hash(type
, event_id
);
4500 return &hlist
->heads
[hash
];
4503 /* For the read side: events when they trigger */
4504 static inline struct hlist_head
*
4505 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
4507 struct swevent_hlist
*hlist
;
4509 hlist
= rcu_dereference(swhash
->swevent_hlist
);
4513 return __find_swevent_head(hlist
, type
, event_id
);
4516 /* For the event head insertion and removal in the hlist */
4517 static inline struct hlist_head
*
4518 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
4520 struct swevent_hlist
*hlist
;
4521 u32 event_id
= event
->attr
.config
;
4522 u64 type
= event
->attr
.type
;
4525 * Event scheduling is always serialized against hlist allocation
4526 * and release. Which makes the protected version suitable here.
4527 * The context lock guarantees that.
4529 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
4530 lockdep_is_held(&event
->ctx
->lock
));
4534 return __find_swevent_head(hlist
, type
, event_id
);
4537 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4539 struct perf_sample_data
*data
,
4540 struct pt_regs
*regs
)
4542 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4543 struct perf_event
*event
;
4544 struct hlist_node
*node
;
4545 struct hlist_head
*head
;
4548 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
4552 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4553 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4554 perf_swevent_event(event
, nr
, nmi
, data
, regs
);
4560 int perf_swevent_get_recursion_context(void)
4562 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4564 return get_recursion_context(swhash
->recursion
);
4566 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4568 void inline perf_swevent_put_recursion_context(int rctx
)
4570 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4572 put_recursion_context(swhash
->recursion
, rctx
);
4575 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
4576 struct pt_regs
*regs
, u64 addr
)
4578 struct perf_sample_data data
;
4581 preempt_disable_notrace();
4582 rctx
= perf_swevent_get_recursion_context();
4586 perf_sample_data_init(&data
, addr
);
4588 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
4590 perf_swevent_put_recursion_context(rctx
);
4591 preempt_enable_notrace();
4594 static void perf_swevent_read(struct perf_event
*event
)
4598 static int perf_swevent_add(struct perf_event
*event
, int flags
)
4600 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4601 struct hw_perf_event
*hwc
= &event
->hw
;
4602 struct hlist_head
*head
;
4604 if (is_sampling_event(event
)) {
4605 hwc
->last_period
= hwc
->sample_period
;
4606 perf_swevent_set_period(event
);
4609 hwc
->state
= !(flags
& PERF_EF_START
);
4611 head
= find_swevent_head(swhash
, event
);
4612 if (WARN_ON_ONCE(!head
))
4615 hlist_add_head_rcu(&event
->hlist_entry
, head
);
4620 static void perf_swevent_del(struct perf_event
*event
, int flags
)
4622 hlist_del_rcu(&event
->hlist_entry
);
4625 static void perf_swevent_start(struct perf_event
*event
, int flags
)
4627 event
->hw
.state
= 0;
4630 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
4632 event
->hw
.state
= PERF_HES_STOPPED
;
4635 /* Deref the hlist from the update side */
4636 static inline struct swevent_hlist
*
4637 swevent_hlist_deref(struct swevent_htable
*swhash
)
4639 return rcu_dereference_protected(swhash
->swevent_hlist
,
4640 lockdep_is_held(&swhash
->hlist_mutex
));
4643 static void swevent_hlist_release_rcu(struct rcu_head
*rcu_head
)
4645 struct swevent_hlist
*hlist
;
4647 hlist
= container_of(rcu_head
, struct swevent_hlist
, rcu_head
);
4651 static void swevent_hlist_release(struct swevent_htable
*swhash
)
4653 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
4658 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
4659 call_rcu(&hlist
->rcu_head
, swevent_hlist_release_rcu
);
4662 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
4664 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4666 mutex_lock(&swhash
->hlist_mutex
);
4668 if (!--swhash
->hlist_refcount
)
4669 swevent_hlist_release(swhash
);
4671 mutex_unlock(&swhash
->hlist_mutex
);
4674 static void swevent_hlist_put(struct perf_event
*event
)
4678 if (event
->cpu
!= -1) {
4679 swevent_hlist_put_cpu(event
, event
->cpu
);
4683 for_each_possible_cpu(cpu
)
4684 swevent_hlist_put_cpu(event
, cpu
);
4687 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
4689 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4692 mutex_lock(&swhash
->hlist_mutex
);
4694 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
4695 struct swevent_hlist
*hlist
;
4697 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
4702 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
4704 swhash
->hlist_refcount
++;
4706 mutex_unlock(&swhash
->hlist_mutex
);
4711 static int swevent_hlist_get(struct perf_event
*event
)
4714 int cpu
, failed_cpu
;
4716 if (event
->cpu
!= -1)
4717 return swevent_hlist_get_cpu(event
, event
->cpu
);
4720 for_each_possible_cpu(cpu
) {
4721 err
= swevent_hlist_get_cpu(event
, cpu
);
4731 for_each_possible_cpu(cpu
) {
4732 if (cpu
== failed_cpu
)
4734 swevent_hlist_put_cpu(event
, cpu
);
4741 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4743 static void sw_perf_event_destroy(struct perf_event
*event
)
4745 u64 event_id
= event
->attr
.config
;
4747 WARN_ON(event
->parent
);
4749 jump_label_dec(&perf_swevent_enabled
[event_id
]);
4750 swevent_hlist_put(event
);
4753 static int perf_swevent_init(struct perf_event
*event
)
4755 int event_id
= event
->attr
.config
;
4757 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
4761 case PERF_COUNT_SW_CPU_CLOCK
:
4762 case PERF_COUNT_SW_TASK_CLOCK
:
4769 if (event_id
> PERF_COUNT_SW_MAX
)
4772 if (!event
->parent
) {
4775 err
= swevent_hlist_get(event
);
4779 jump_label_inc(&perf_swevent_enabled
[event_id
]);
4780 event
->destroy
= sw_perf_event_destroy
;
4786 static struct pmu perf_swevent
= {
4787 .task_ctx_nr
= perf_sw_context
,
4789 .event_init
= perf_swevent_init
,
4790 .add
= perf_swevent_add
,
4791 .del
= perf_swevent_del
,
4792 .start
= perf_swevent_start
,
4793 .stop
= perf_swevent_stop
,
4794 .read
= perf_swevent_read
,
4797 #ifdef CONFIG_EVENT_TRACING
4799 static int perf_tp_filter_match(struct perf_event
*event
,
4800 struct perf_sample_data
*data
)
4802 void *record
= data
->raw
->data
;
4804 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
4809 static int perf_tp_event_match(struct perf_event
*event
,
4810 struct perf_sample_data
*data
,
4811 struct pt_regs
*regs
)
4814 * All tracepoints are from kernel-space.
4816 if (event
->attr
.exclude_kernel
)
4819 if (!perf_tp_filter_match(event
, data
))
4825 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
4826 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
4828 struct perf_sample_data data
;
4829 struct perf_event
*event
;
4830 struct hlist_node
*node
;
4832 struct perf_raw_record raw
= {
4837 perf_sample_data_init(&data
, addr
);
4840 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4841 if (perf_tp_event_match(event
, &data
, regs
))
4842 perf_swevent_event(event
, count
, 1, &data
, regs
);
4845 perf_swevent_put_recursion_context(rctx
);
4847 EXPORT_SYMBOL_GPL(perf_tp_event
);
4849 static void tp_perf_event_destroy(struct perf_event
*event
)
4851 perf_trace_destroy(event
);
4854 static int perf_tp_event_init(struct perf_event
*event
)
4858 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4861 err
= perf_trace_init(event
);
4865 event
->destroy
= tp_perf_event_destroy
;
4870 static struct pmu perf_tracepoint
= {
4871 .task_ctx_nr
= perf_sw_context
,
4873 .event_init
= perf_tp_event_init
,
4874 .add
= perf_trace_add
,
4875 .del
= perf_trace_del
,
4876 .start
= perf_swevent_start
,
4877 .stop
= perf_swevent_stop
,
4878 .read
= perf_swevent_read
,
4881 static inline void perf_tp_register(void)
4883 perf_pmu_register(&perf_tracepoint
);
4886 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4891 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4894 filter_str
= strndup_user(arg
, PAGE_SIZE
);
4895 if (IS_ERR(filter_str
))
4896 return PTR_ERR(filter_str
);
4898 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
4904 static void perf_event_free_filter(struct perf_event
*event
)
4906 ftrace_profile_free_filter(event
);
4911 static inline void perf_tp_register(void)
4915 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4920 static void perf_event_free_filter(struct perf_event
*event
)
4924 #endif /* CONFIG_EVENT_TRACING */
4926 #ifdef CONFIG_HAVE_HW_BREAKPOINT
4927 void perf_bp_event(struct perf_event
*bp
, void *data
)
4929 struct perf_sample_data sample
;
4930 struct pt_regs
*regs
= data
;
4932 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
4934 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
4935 perf_swevent_event(bp
, 1, 1, &sample
, regs
);
4940 * hrtimer based swevent callback
4943 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
4945 enum hrtimer_restart ret
= HRTIMER_RESTART
;
4946 struct perf_sample_data data
;
4947 struct pt_regs
*regs
;
4948 struct perf_event
*event
;
4951 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
4952 event
->pmu
->read(event
);
4954 perf_sample_data_init(&data
, 0);
4955 data
.period
= event
->hw
.last_period
;
4956 regs
= get_irq_regs();
4958 if (regs
&& !perf_exclude_event(event
, regs
)) {
4959 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
4960 if (perf_event_overflow(event
, 0, &data
, regs
))
4961 ret
= HRTIMER_NORESTART
;
4964 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
4965 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
4970 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
4972 struct hw_perf_event
*hwc
= &event
->hw
;
4975 if (!is_sampling_event(event
))
4978 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
4979 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
4981 period
= local64_read(&hwc
->period_left
);
4986 local64_set(&hwc
->period_left
, 0);
4988 period
= max_t(u64
, 10000, hwc
->sample_period
);
4990 __hrtimer_start_range_ns(&hwc
->hrtimer
,
4991 ns_to_ktime(period
), 0,
4992 HRTIMER_MODE_REL_PINNED
, 0);
4995 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
4997 struct hw_perf_event
*hwc
= &event
->hw
;
4999 if (is_sampling_event(event
)) {
5000 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5001 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5003 hrtimer_cancel(&hwc
->hrtimer
);
5008 * Software event: cpu wall time clock
5011 static void cpu_clock_event_update(struct perf_event
*event
)
5016 now
= local_clock();
5017 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5018 local64_add(now
- prev
, &event
->count
);
5021 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5023 local64_set(&event
->hw
.prev_count
, local_clock());
5024 perf_swevent_start_hrtimer(event
);
5027 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5029 perf_swevent_cancel_hrtimer(event
);
5030 cpu_clock_event_update(event
);
5033 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5035 if (flags
& PERF_EF_START
)
5036 cpu_clock_event_start(event
, flags
);
5041 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5043 cpu_clock_event_stop(event
, flags
);
5046 static void cpu_clock_event_read(struct perf_event
*event
)
5048 cpu_clock_event_update(event
);
5051 static int cpu_clock_event_init(struct perf_event
*event
)
5053 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5056 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5062 static struct pmu perf_cpu_clock
= {
5063 .task_ctx_nr
= perf_sw_context
,
5065 .event_init
= cpu_clock_event_init
,
5066 .add
= cpu_clock_event_add
,
5067 .del
= cpu_clock_event_del
,
5068 .start
= cpu_clock_event_start
,
5069 .stop
= cpu_clock_event_stop
,
5070 .read
= cpu_clock_event_read
,
5074 * Software event: task time clock
5077 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5082 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5084 local64_add(delta
, &event
->count
);
5087 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5089 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5090 perf_swevent_start_hrtimer(event
);
5093 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5095 perf_swevent_cancel_hrtimer(event
);
5096 task_clock_event_update(event
, event
->ctx
->time
);
5099 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5101 if (flags
& PERF_EF_START
)
5102 task_clock_event_start(event
, flags
);
5107 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5109 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5112 static void task_clock_event_read(struct perf_event
*event
)
5117 update_context_time(event
->ctx
);
5118 time
= event
->ctx
->time
;
5120 u64 now
= perf_clock();
5121 u64 delta
= now
- event
->ctx
->timestamp
;
5122 time
= event
->ctx
->time
+ delta
;
5125 task_clock_event_update(event
, time
);
5128 static int task_clock_event_init(struct perf_event
*event
)
5130 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5133 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5139 static struct pmu perf_task_clock
= {
5140 .task_ctx_nr
= perf_sw_context
,
5142 .event_init
= task_clock_event_init
,
5143 .add
= task_clock_event_add
,
5144 .del
= task_clock_event_del
,
5145 .start
= task_clock_event_start
,
5146 .stop
= task_clock_event_stop
,
5147 .read
= task_clock_event_read
,
5150 static void perf_pmu_nop_void(struct pmu
*pmu
)
5154 static int perf_pmu_nop_int(struct pmu
*pmu
)
5159 static void perf_pmu_start_txn(struct pmu
*pmu
)
5161 perf_pmu_disable(pmu
);
5164 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5166 perf_pmu_enable(pmu
);
5170 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5172 perf_pmu_enable(pmu
);
5176 * Ensures all contexts with the same task_ctx_nr have the same
5177 * pmu_cpu_context too.
5179 static void *find_pmu_context(int ctxn
)
5186 list_for_each_entry(pmu
, &pmus
, entry
) {
5187 if (pmu
->task_ctx_nr
== ctxn
)
5188 return pmu
->pmu_cpu_context
;
5194 static void free_pmu_context(void * __percpu cpu_context
)
5198 mutex_lock(&pmus_lock
);
5200 * Like a real lame refcount.
5202 list_for_each_entry(pmu
, &pmus
, entry
) {
5203 if (pmu
->pmu_cpu_context
== cpu_context
)
5207 free_percpu(cpu_context
);
5209 mutex_unlock(&pmus_lock
);
5212 int perf_pmu_register(struct pmu
*pmu
)
5216 mutex_lock(&pmus_lock
);
5218 pmu
->pmu_disable_count
= alloc_percpu(int);
5219 if (!pmu
->pmu_disable_count
)
5222 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
5223 if (pmu
->pmu_cpu_context
)
5224 goto got_cpu_context
;
5226 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
5227 if (!pmu
->pmu_cpu_context
)
5230 for_each_possible_cpu(cpu
) {
5231 struct perf_cpu_context
*cpuctx
;
5233 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5234 __perf_event_init_context(&cpuctx
->ctx
);
5235 cpuctx
->ctx
.type
= cpu_context
;
5236 cpuctx
->ctx
.pmu
= pmu
;
5237 cpuctx
->jiffies_interval
= 1;
5238 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
5242 if (!pmu
->start_txn
) {
5243 if (pmu
->pmu_enable
) {
5245 * If we have pmu_enable/pmu_disable calls, install
5246 * transaction stubs that use that to try and batch
5247 * hardware accesses.
5249 pmu
->start_txn
= perf_pmu_start_txn
;
5250 pmu
->commit_txn
= perf_pmu_commit_txn
;
5251 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
5253 pmu
->start_txn
= perf_pmu_nop_void
;
5254 pmu
->commit_txn
= perf_pmu_nop_int
;
5255 pmu
->cancel_txn
= perf_pmu_nop_void
;
5259 if (!pmu
->pmu_enable
) {
5260 pmu
->pmu_enable
= perf_pmu_nop_void
;
5261 pmu
->pmu_disable
= perf_pmu_nop_void
;
5264 list_add_rcu(&pmu
->entry
, &pmus
);
5267 mutex_unlock(&pmus_lock
);
5272 free_percpu(pmu
->pmu_disable_count
);
5276 void perf_pmu_unregister(struct pmu
*pmu
)
5278 mutex_lock(&pmus_lock
);
5279 list_del_rcu(&pmu
->entry
);
5280 mutex_unlock(&pmus_lock
);
5283 * We dereference the pmu list under both SRCU and regular RCU, so
5284 * synchronize against both of those.
5286 synchronize_srcu(&pmus_srcu
);
5289 free_percpu(pmu
->pmu_disable_count
);
5290 free_pmu_context(pmu
->pmu_cpu_context
);
5293 struct pmu
*perf_init_event(struct perf_event
*event
)
5295 struct pmu
*pmu
= NULL
;
5298 idx
= srcu_read_lock(&pmus_srcu
);
5299 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5300 int ret
= pmu
->event_init(event
);
5304 if (ret
!= -ENOENT
) {
5309 pmu
= ERR_PTR(-ENOENT
);
5311 srcu_read_unlock(&pmus_srcu
, idx
);
5317 * Allocate and initialize a event structure
5319 static struct perf_event
*
5320 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
5321 struct task_struct
*task
,
5322 struct perf_event
*group_leader
,
5323 struct perf_event
*parent_event
,
5324 perf_overflow_handler_t overflow_handler
)
5327 struct perf_event
*event
;
5328 struct hw_perf_event
*hwc
;
5331 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
5333 return ERR_PTR(-ENOMEM
);
5336 * Single events are their own group leaders, with an
5337 * empty sibling list:
5340 group_leader
= event
;
5342 mutex_init(&event
->child_mutex
);
5343 INIT_LIST_HEAD(&event
->child_list
);
5345 INIT_LIST_HEAD(&event
->group_entry
);
5346 INIT_LIST_HEAD(&event
->event_entry
);
5347 INIT_LIST_HEAD(&event
->sibling_list
);
5348 init_waitqueue_head(&event
->waitq
);
5349 init_irq_work(&event
->pending
, perf_pending_event
);
5351 mutex_init(&event
->mmap_mutex
);
5354 event
->attr
= *attr
;
5355 event
->group_leader
= group_leader
;
5359 event
->parent
= parent_event
;
5361 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
5362 event
->id
= atomic64_inc_return(&perf_event_id
);
5364 event
->state
= PERF_EVENT_STATE_INACTIVE
;
5367 event
->attach_state
= PERF_ATTACH_TASK
;
5368 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5370 * hw_breakpoint is a bit difficult here..
5372 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
5373 event
->hw
.bp_target
= task
;
5377 if (!overflow_handler
&& parent_event
)
5378 overflow_handler
= parent_event
->overflow_handler
;
5380 event
->overflow_handler
= overflow_handler
;
5383 event
->state
= PERF_EVENT_STATE_OFF
;
5388 hwc
->sample_period
= attr
->sample_period
;
5389 if (attr
->freq
&& attr
->sample_freq
)
5390 hwc
->sample_period
= 1;
5391 hwc
->last_period
= hwc
->sample_period
;
5393 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5396 * we currently do not support PERF_FORMAT_GROUP on inherited events
5398 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
5401 pmu
= perf_init_event(event
);
5407 else if (IS_ERR(pmu
))
5412 put_pid_ns(event
->ns
);
5414 return ERR_PTR(err
);
5419 if (!event
->parent
) {
5420 if (event
->attach_state
& PERF_ATTACH_TASK
)
5421 jump_label_inc(&perf_task_events
);
5422 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
5423 atomic_inc(&nr_mmap_events
);
5424 if (event
->attr
.comm
)
5425 atomic_inc(&nr_comm_events
);
5426 if (event
->attr
.task
)
5427 atomic_inc(&nr_task_events
);
5428 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5429 err
= get_callchain_buffers();
5432 return ERR_PTR(err
);
5440 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5441 struct perf_event_attr
*attr
)
5446 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
5450 * zero the full structure, so that a short copy will be nice.
5452 memset(attr
, 0, sizeof(*attr
));
5454 ret
= get_user(size
, &uattr
->size
);
5458 if (size
> PAGE_SIZE
) /* silly large */
5461 if (!size
) /* abi compat */
5462 size
= PERF_ATTR_SIZE_VER0
;
5464 if (size
< PERF_ATTR_SIZE_VER0
)
5468 * If we're handed a bigger struct than we know of,
5469 * ensure all the unknown bits are 0 - i.e. new
5470 * user-space does not rely on any kernel feature
5471 * extensions we dont know about yet.
5473 if (size
> sizeof(*attr
)) {
5474 unsigned char __user
*addr
;
5475 unsigned char __user
*end
;
5478 addr
= (void __user
*)uattr
+ sizeof(*attr
);
5479 end
= (void __user
*)uattr
+ size
;
5481 for (; addr
< end
; addr
++) {
5482 ret
= get_user(val
, addr
);
5488 size
= sizeof(*attr
);
5491 ret
= copy_from_user(attr
, uattr
, size
);
5496 * If the type exists, the corresponding creation will verify
5499 if (attr
->type
>= PERF_TYPE_MAX
)
5502 if (attr
->__reserved_1
)
5505 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
5508 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
5515 put_user(sizeof(*attr
), &uattr
->size
);
5521 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
5523 struct perf_buffer
*buffer
= NULL
, *old_buffer
= NULL
;
5529 /* don't allow circular references */
5530 if (event
== output_event
)
5534 * Don't allow cross-cpu buffers
5536 if (output_event
->cpu
!= event
->cpu
)
5540 * If its not a per-cpu buffer, it must be the same task.
5542 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
5546 mutex_lock(&event
->mmap_mutex
);
5547 /* Can't redirect output if we've got an active mmap() */
5548 if (atomic_read(&event
->mmap_count
))
5552 /* get the buffer we want to redirect to */
5553 buffer
= perf_buffer_get(output_event
);
5558 old_buffer
= event
->buffer
;
5559 rcu_assign_pointer(event
->buffer
, buffer
);
5562 mutex_unlock(&event
->mmap_mutex
);
5565 perf_buffer_put(old_buffer
);
5571 * sys_perf_event_open - open a performance event, associate it to a task/cpu
5573 * @attr_uptr: event_id type attributes for monitoring/sampling
5576 * @group_fd: group leader event fd
5578 SYSCALL_DEFINE5(perf_event_open
,
5579 struct perf_event_attr __user
*, attr_uptr
,
5580 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
5582 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
5583 struct perf_event
*event
, *sibling
;
5584 struct perf_event_attr attr
;
5585 struct perf_event_context
*ctx
;
5586 struct file
*event_file
= NULL
;
5587 struct file
*group_file
= NULL
;
5588 struct task_struct
*task
= NULL
;
5592 int fput_needed
= 0;
5595 /* for future expandability... */
5596 if (flags
& ~(PERF_FLAG_FD_NO_GROUP
| PERF_FLAG_FD_OUTPUT
))
5599 err
= perf_copy_attr(attr_uptr
, &attr
);
5603 if (!attr
.exclude_kernel
) {
5604 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
5609 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
5613 event_fd
= get_unused_fd_flags(O_RDWR
);
5617 if (group_fd
!= -1) {
5618 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
5619 if (IS_ERR(group_leader
)) {
5620 err
= PTR_ERR(group_leader
);
5623 group_file
= group_leader
->filp
;
5624 if (flags
& PERF_FLAG_FD_OUTPUT
)
5625 output_event
= group_leader
;
5626 if (flags
& PERF_FLAG_FD_NO_GROUP
)
5627 group_leader
= NULL
;
5631 task
= find_lively_task_by_vpid(pid
);
5633 err
= PTR_ERR(task
);
5638 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
, NULL
);
5639 if (IS_ERR(event
)) {
5640 err
= PTR_ERR(event
);
5645 * Special case software events and allow them to be part of
5646 * any hardware group.
5651 (is_software_event(event
) != is_software_event(group_leader
))) {
5652 if (is_software_event(event
)) {
5654 * If event and group_leader are not both a software
5655 * event, and event is, then group leader is not.
5657 * Allow the addition of software events to !software
5658 * groups, this is safe because software events never
5661 pmu
= group_leader
->pmu
;
5662 } else if (is_software_event(group_leader
) &&
5663 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
5665 * In case the group is a pure software group, and we
5666 * try to add a hardware event, move the whole group to
5667 * the hardware context.
5674 * Get the target context (task or percpu):
5676 ctx
= find_get_context(pmu
, task
, cpu
);
5683 * Look up the group leader (we will attach this event to it):
5689 * Do not allow a recursive hierarchy (this new sibling
5690 * becoming part of another group-sibling):
5692 if (group_leader
->group_leader
!= group_leader
)
5695 * Do not allow to attach to a group in a different
5696 * task or CPU context:
5699 if (group_leader
->ctx
->type
!= ctx
->type
)
5702 if (group_leader
->ctx
!= ctx
)
5707 * Only a group leader can be exclusive or pinned
5709 if (attr
.exclusive
|| attr
.pinned
)
5714 err
= perf_event_set_output(event
, output_event
);
5719 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
5720 if (IS_ERR(event_file
)) {
5721 err
= PTR_ERR(event_file
);
5726 struct perf_event_context
*gctx
= group_leader
->ctx
;
5728 mutex_lock(&gctx
->mutex
);
5729 perf_event_remove_from_context(group_leader
);
5730 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
5732 perf_event_remove_from_context(sibling
);
5735 mutex_unlock(&gctx
->mutex
);
5739 event
->filp
= event_file
;
5740 WARN_ON_ONCE(ctx
->parent_ctx
);
5741 mutex_lock(&ctx
->mutex
);
5744 perf_install_in_context(ctx
, group_leader
, cpu
);
5746 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
5748 perf_install_in_context(ctx
, sibling
, cpu
);
5753 perf_install_in_context(ctx
, event
, cpu
);
5755 mutex_unlock(&ctx
->mutex
);
5757 event
->owner
= current
;
5759 mutex_lock(¤t
->perf_event_mutex
);
5760 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
5761 mutex_unlock(¤t
->perf_event_mutex
);
5764 * Precalculate sample_data sizes
5766 perf_event__header_size(event
);
5767 perf_event__id_header_size(event
);
5770 * Drop the reference on the group_event after placing the
5771 * new event on the sibling_list. This ensures destruction
5772 * of the group leader will find the pointer to itself in
5773 * perf_group_detach().
5775 fput_light(group_file
, fput_needed
);
5776 fd_install(event_fd
, event_file
);
5785 put_task_struct(task
);
5787 fput_light(group_file
, fput_needed
);
5789 put_unused_fd(event_fd
);
5794 * perf_event_create_kernel_counter
5796 * @attr: attributes of the counter to create
5797 * @cpu: cpu in which the counter is bound
5798 * @task: task to profile (NULL for percpu)
5801 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
5802 struct task_struct
*task
,
5803 perf_overflow_handler_t overflow_handler
)
5805 struct perf_event_context
*ctx
;
5806 struct perf_event
*event
;
5810 * Get the target context (task or percpu):
5813 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
, overflow_handler
);
5814 if (IS_ERR(event
)) {
5815 err
= PTR_ERR(event
);
5819 ctx
= find_get_context(event
->pmu
, task
, cpu
);
5826 WARN_ON_ONCE(ctx
->parent_ctx
);
5827 mutex_lock(&ctx
->mutex
);
5828 perf_install_in_context(ctx
, event
, cpu
);
5830 mutex_unlock(&ctx
->mutex
);
5837 return ERR_PTR(err
);
5839 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
5841 static void sync_child_event(struct perf_event
*child_event
,
5842 struct task_struct
*child
)
5844 struct perf_event
*parent_event
= child_event
->parent
;
5847 if (child_event
->attr
.inherit_stat
)
5848 perf_event_read_event(child_event
, child
);
5850 child_val
= perf_event_count(child_event
);
5853 * Add back the child's count to the parent's count:
5855 atomic64_add(child_val
, &parent_event
->child_count
);
5856 atomic64_add(child_event
->total_time_enabled
,
5857 &parent_event
->child_total_time_enabled
);
5858 atomic64_add(child_event
->total_time_running
,
5859 &parent_event
->child_total_time_running
);
5862 * Remove this event from the parent's list
5864 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
5865 mutex_lock(&parent_event
->child_mutex
);
5866 list_del_init(&child_event
->child_list
);
5867 mutex_unlock(&parent_event
->child_mutex
);
5870 * Release the parent event, if this was the last
5873 fput(parent_event
->filp
);
5877 __perf_event_exit_task(struct perf_event
*child_event
,
5878 struct perf_event_context
*child_ctx
,
5879 struct task_struct
*child
)
5881 struct perf_event
*parent_event
;
5883 perf_event_remove_from_context(child_event
);
5885 parent_event
= child_event
->parent
;
5887 * It can happen that parent exits first, and has events
5888 * that are still around due to the child reference. These
5889 * events need to be zapped - but otherwise linger.
5892 sync_child_event(child_event
, child
);
5893 free_event(child_event
);
5897 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
5899 struct perf_event
*child_event
, *tmp
;
5900 struct perf_event_context
*child_ctx
;
5901 unsigned long flags
;
5903 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
5904 perf_event_task(child
, NULL
, 0);
5908 local_irq_save(flags
);
5910 * We can't reschedule here because interrupts are disabled,
5911 * and either child is current or it is a task that can't be
5912 * scheduled, so we are now safe from rescheduling changing
5915 child_ctx
= child
->perf_event_ctxp
[ctxn
];
5916 task_ctx_sched_out(child_ctx
, EVENT_ALL
);
5919 * Take the context lock here so that if find_get_context is
5920 * reading child->perf_event_ctxp, we wait until it has
5921 * incremented the context's refcount before we do put_ctx below.
5923 raw_spin_lock(&child_ctx
->lock
);
5924 child
->perf_event_ctxp
[ctxn
] = NULL
;
5926 * If this context is a clone; unclone it so it can't get
5927 * swapped to another process while we're removing all
5928 * the events from it.
5930 unclone_ctx(child_ctx
);
5931 update_context_time(child_ctx
);
5932 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
5935 * Report the task dead after unscheduling the events so that we
5936 * won't get any samples after PERF_RECORD_EXIT. We can however still
5937 * get a few PERF_RECORD_READ events.
5939 perf_event_task(child
, child_ctx
, 0);
5942 * We can recurse on the same lock type through:
5944 * __perf_event_exit_task()
5945 * sync_child_event()
5946 * fput(parent_event->filp)
5948 * mutex_lock(&ctx->mutex)
5950 * But since its the parent context it won't be the same instance.
5952 mutex_lock(&child_ctx
->mutex
);
5955 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
5957 __perf_event_exit_task(child_event
, child_ctx
, child
);
5959 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
5961 __perf_event_exit_task(child_event
, child_ctx
, child
);
5964 * If the last event was a group event, it will have appended all
5965 * its siblings to the list, but we obtained 'tmp' before that which
5966 * will still point to the list head terminating the iteration.
5968 if (!list_empty(&child_ctx
->pinned_groups
) ||
5969 !list_empty(&child_ctx
->flexible_groups
))
5972 mutex_unlock(&child_ctx
->mutex
);
5978 * When a child task exits, feed back event values to parent events.
5980 void perf_event_exit_task(struct task_struct
*child
)
5982 struct perf_event
*event
, *tmp
;
5985 mutex_lock(&child
->perf_event_mutex
);
5986 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
5988 list_del_init(&event
->owner_entry
);
5991 * Ensure the list deletion is visible before we clear
5992 * the owner, closes a race against perf_release() where
5993 * we need to serialize on the owner->perf_event_mutex.
5996 event
->owner
= NULL
;
5998 mutex_unlock(&child
->perf_event_mutex
);
6000 for_each_task_context_nr(ctxn
)
6001 perf_event_exit_task_context(child
, ctxn
);
6004 static void perf_free_event(struct perf_event
*event
,
6005 struct perf_event_context
*ctx
)
6007 struct perf_event
*parent
= event
->parent
;
6009 if (WARN_ON_ONCE(!parent
))
6012 mutex_lock(&parent
->child_mutex
);
6013 list_del_init(&event
->child_list
);
6014 mutex_unlock(&parent
->child_mutex
);
6018 perf_group_detach(event
);
6019 list_del_event(event
, ctx
);
6024 * free an unexposed, unused context as created by inheritance by
6025 * perf_event_init_task below, used by fork() in case of fail.
6027 void perf_event_free_task(struct task_struct
*task
)
6029 struct perf_event_context
*ctx
;
6030 struct perf_event
*event
, *tmp
;
6033 for_each_task_context_nr(ctxn
) {
6034 ctx
= task
->perf_event_ctxp
[ctxn
];
6038 mutex_lock(&ctx
->mutex
);
6040 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6042 perf_free_event(event
, ctx
);
6044 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6046 perf_free_event(event
, ctx
);
6048 if (!list_empty(&ctx
->pinned_groups
) ||
6049 !list_empty(&ctx
->flexible_groups
))
6052 mutex_unlock(&ctx
->mutex
);
6058 void perf_event_delayed_put(struct task_struct
*task
)
6062 for_each_task_context_nr(ctxn
)
6063 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6067 * inherit a event from parent task to child task:
6069 static struct perf_event
*
6070 inherit_event(struct perf_event
*parent_event
,
6071 struct task_struct
*parent
,
6072 struct perf_event_context
*parent_ctx
,
6073 struct task_struct
*child
,
6074 struct perf_event
*group_leader
,
6075 struct perf_event_context
*child_ctx
)
6077 struct perf_event
*child_event
;
6078 unsigned long flags
;
6081 * Instead of creating recursive hierarchies of events,
6082 * we link inherited events back to the original parent,
6083 * which has a filp for sure, which we use as the reference
6086 if (parent_event
->parent
)
6087 parent_event
= parent_event
->parent
;
6089 child_event
= perf_event_alloc(&parent_event
->attr
,
6092 group_leader
, parent_event
,
6094 if (IS_ERR(child_event
))
6099 * Make the child state follow the state of the parent event,
6100 * not its attr.disabled bit. We hold the parent's mutex,
6101 * so we won't race with perf_event_{en, dis}able_family.
6103 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6104 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6106 child_event
->state
= PERF_EVENT_STATE_OFF
;
6108 if (parent_event
->attr
.freq
) {
6109 u64 sample_period
= parent_event
->hw
.sample_period
;
6110 struct hw_perf_event
*hwc
= &child_event
->hw
;
6112 hwc
->sample_period
= sample_period
;
6113 hwc
->last_period
= sample_period
;
6115 local64_set(&hwc
->period_left
, sample_period
);
6118 child_event
->ctx
= child_ctx
;
6119 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6122 * Precalculate sample_data sizes
6124 perf_event__header_size(child_event
);
6125 perf_event__id_header_size(child_event
);
6128 * Link it up in the child's context:
6130 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6131 add_event_to_ctx(child_event
, child_ctx
);
6132 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6135 * Get a reference to the parent filp - we will fput it
6136 * when the child event exits. This is safe to do because
6137 * we are in the parent and we know that the filp still
6138 * exists and has a nonzero count:
6140 atomic_long_inc(&parent_event
->filp
->f_count
);
6143 * Link this into the parent event's child list
6145 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6146 mutex_lock(&parent_event
->child_mutex
);
6147 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
6148 mutex_unlock(&parent_event
->child_mutex
);
6153 static int inherit_group(struct perf_event
*parent_event
,
6154 struct task_struct
*parent
,
6155 struct perf_event_context
*parent_ctx
,
6156 struct task_struct
*child
,
6157 struct perf_event_context
*child_ctx
)
6159 struct perf_event
*leader
;
6160 struct perf_event
*sub
;
6161 struct perf_event
*child_ctr
;
6163 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
6164 child
, NULL
, child_ctx
);
6166 return PTR_ERR(leader
);
6167 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
6168 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
6169 child
, leader
, child_ctx
);
6170 if (IS_ERR(child_ctr
))
6171 return PTR_ERR(child_ctr
);
6177 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
6178 struct perf_event_context
*parent_ctx
,
6179 struct task_struct
*child
, int ctxn
,
6183 struct perf_event_context
*child_ctx
;
6185 if (!event
->attr
.inherit
) {
6190 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6193 * This is executed from the parent task context, so
6194 * inherit events that have been marked for cloning.
6195 * First allocate and initialize a context for the
6199 child_ctx
= alloc_perf_context(event
->pmu
, child
);
6203 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
6206 ret
= inherit_group(event
, parent
, parent_ctx
,
6216 * Initialize the perf_event context in task_struct
6218 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
6220 struct perf_event_context
*child_ctx
, *parent_ctx
;
6221 struct perf_event_context
*cloned_ctx
;
6222 struct perf_event
*event
;
6223 struct task_struct
*parent
= current
;
6224 int inherited_all
= 1;
6225 unsigned long flags
;
6228 child
->perf_event_ctxp
[ctxn
] = NULL
;
6230 mutex_init(&child
->perf_event_mutex
);
6231 INIT_LIST_HEAD(&child
->perf_event_list
);
6233 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
6237 * If the parent's context is a clone, pin it so it won't get
6240 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
6243 * No need to check if parent_ctx != NULL here; since we saw
6244 * it non-NULL earlier, the only reason for it to become NULL
6245 * is if we exit, and since we're currently in the middle of
6246 * a fork we can't be exiting at the same time.
6250 * Lock the parent list. No need to lock the child - not PID
6251 * hashed yet and not running, so nobody can access it.
6253 mutex_lock(&parent_ctx
->mutex
);
6256 * We dont have to disable NMIs - we are only looking at
6257 * the list, not manipulating it:
6259 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
6260 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6261 child
, ctxn
, &inherited_all
);
6267 * We can't hold ctx->lock when iterating the ->flexible_group list due
6268 * to allocations, but we need to prevent rotation because
6269 * rotate_ctx() will change the list from interrupt context.
6271 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6272 parent_ctx
->rotate_disable
= 1;
6273 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6275 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
6276 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6277 child
, ctxn
, &inherited_all
);
6282 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6283 parent_ctx
->rotate_disable
= 0;
6284 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6286 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6288 if (child_ctx
&& inherited_all
) {
6290 * Mark the child context as a clone of the parent
6291 * context, or of whatever the parent is a clone of.
6292 * Note that if the parent is a clone, it could get
6293 * uncloned at any point, but that doesn't matter
6294 * because the list of events and the generation
6295 * count can't have changed since we took the mutex.
6297 cloned_ctx
= rcu_dereference(parent_ctx
->parent_ctx
);
6299 child_ctx
->parent_ctx
= cloned_ctx
;
6300 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
6302 child_ctx
->parent_ctx
= parent_ctx
;
6303 child_ctx
->parent_gen
= parent_ctx
->generation
;
6305 get_ctx(child_ctx
->parent_ctx
);
6308 mutex_unlock(&parent_ctx
->mutex
);
6310 perf_unpin_context(parent_ctx
);
6316 * Initialize the perf_event context in task_struct
6318 int perf_event_init_task(struct task_struct
*child
)
6322 for_each_task_context_nr(ctxn
) {
6323 ret
= perf_event_init_context(child
, ctxn
);
6331 static void __init
perf_event_init_all_cpus(void)
6333 struct swevent_htable
*swhash
;
6336 for_each_possible_cpu(cpu
) {
6337 swhash
= &per_cpu(swevent_htable
, cpu
);
6338 mutex_init(&swhash
->hlist_mutex
);
6339 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
6343 static void __cpuinit
perf_event_init_cpu(int cpu
)
6345 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6347 mutex_lock(&swhash
->hlist_mutex
);
6348 if (swhash
->hlist_refcount
> 0) {
6349 struct swevent_hlist
*hlist
;
6351 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
6353 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6355 mutex_unlock(&swhash
->hlist_mutex
);
6358 #ifdef CONFIG_HOTPLUG_CPU
6359 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
6361 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6363 WARN_ON(!irqs_disabled());
6365 list_del_init(&cpuctx
->rotation_list
);
6368 static void __perf_event_exit_context(void *__info
)
6370 struct perf_event_context
*ctx
= __info
;
6371 struct perf_event
*event
, *tmp
;
6373 perf_pmu_rotate_stop(ctx
->pmu
);
6375 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
6376 __perf_event_remove_from_context(event
);
6377 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
6378 __perf_event_remove_from_context(event
);
6381 static void perf_event_exit_cpu_context(int cpu
)
6383 struct perf_event_context
*ctx
;
6387 idx
= srcu_read_lock(&pmus_srcu
);
6388 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6389 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
6391 mutex_lock(&ctx
->mutex
);
6392 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
6393 mutex_unlock(&ctx
->mutex
);
6395 srcu_read_unlock(&pmus_srcu
, idx
);
6398 static void perf_event_exit_cpu(int cpu
)
6400 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6402 mutex_lock(&swhash
->hlist_mutex
);
6403 swevent_hlist_release(swhash
);
6404 mutex_unlock(&swhash
->hlist_mutex
);
6406 perf_event_exit_cpu_context(cpu
);
6409 static inline void perf_event_exit_cpu(int cpu
) { }
6412 static int __cpuinit
6413 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
6415 unsigned int cpu
= (long)hcpu
;
6417 switch (action
& ~CPU_TASKS_FROZEN
) {
6419 case CPU_UP_PREPARE
:
6420 case CPU_DOWN_FAILED
:
6421 perf_event_init_cpu(cpu
);
6424 case CPU_UP_CANCELED
:
6425 case CPU_DOWN_PREPARE
:
6426 perf_event_exit_cpu(cpu
);
6436 void __init
perf_event_init(void)
6440 perf_event_init_all_cpus();
6441 init_srcu_struct(&pmus_srcu
);
6442 perf_pmu_register(&perf_swevent
);
6443 perf_pmu_register(&perf_cpu_clock
);
6444 perf_pmu_register(&perf_task_clock
);
6446 perf_cpu_notifier(perf_cpu_notify
);
6448 ret
= init_hw_breakpoint();
6449 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);