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/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/sysfs.h>
22 #include <linux/dcache.h>
23 #include <linux/percpu.h>
24 #include <linux/ptrace.h>
25 #include <linux/reboot.h>
26 #include <linux/vmstat.h>
27 #include <linux/device.h>
28 #include <linux/vmalloc.h>
29 #include <linux/hardirq.h>
30 #include <linux/rculist.h>
31 #include <linux/uaccess.h>
32 #include <linux/syscalls.h>
33 #include <linux/anon_inodes.h>
34 #include <linux/kernel_stat.h>
35 #include <linux/perf_event.h>
36 #include <linux/ftrace_event.h>
37 #include <linux/hw_breakpoint.h>
39 #include <asm/irq_regs.h>
44 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
47 atomic_t perf_task_events __read_mostly
;
48 static atomic_t nr_mmap_events __read_mostly
;
49 static atomic_t nr_comm_events __read_mostly
;
50 static atomic_t nr_task_events __read_mostly
;
52 static LIST_HEAD(pmus
);
53 static DEFINE_MUTEX(pmus_lock
);
54 static struct srcu_struct pmus_srcu
;
57 * perf event paranoia level:
58 * -1 - not paranoid at all
59 * 0 - disallow raw tracepoint access for unpriv
60 * 1 - disallow cpu events for unpriv
61 * 2 - disallow kernel profiling for unpriv
63 int sysctl_perf_event_paranoid __read_mostly
= 1;
65 int sysctl_perf_event_mlock __read_mostly
= 512; /* 'free' kb per user */
68 * max perf event sample rate
70 int sysctl_perf_event_sample_rate __read_mostly
= 100000;
72 static atomic64_t perf_event_id
;
74 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
75 enum event_type_t event_type
);
77 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
78 enum event_type_t event_type
);
80 void __weak
perf_event_print_debug(void) { }
82 extern __weak
const char *perf_pmu_name(void)
87 static inline u64
perf_clock(void)
92 void perf_pmu_disable(struct pmu
*pmu
)
94 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
96 pmu
->pmu_disable(pmu
);
99 void perf_pmu_enable(struct pmu
*pmu
)
101 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
103 pmu
->pmu_enable(pmu
);
106 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
109 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
110 * because they're strictly cpu affine and rotate_start is called with IRQs
111 * disabled, while rotate_context is called from IRQ context.
113 static void perf_pmu_rotate_start(struct pmu
*pmu
)
115 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
116 struct list_head
*head
= &__get_cpu_var(rotation_list
);
118 WARN_ON(!irqs_disabled());
120 if (list_empty(&cpuctx
->rotation_list
))
121 list_add(&cpuctx
->rotation_list
, head
);
124 static void get_ctx(struct perf_event_context
*ctx
)
126 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
129 static void free_ctx(struct rcu_head
*head
)
131 struct perf_event_context
*ctx
;
133 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
137 static void put_ctx(struct perf_event_context
*ctx
)
139 if (atomic_dec_and_test(&ctx
->refcount
)) {
141 put_ctx(ctx
->parent_ctx
);
143 put_task_struct(ctx
->task
);
144 call_rcu(&ctx
->rcu_head
, free_ctx
);
148 static void unclone_ctx(struct perf_event_context
*ctx
)
150 if (ctx
->parent_ctx
) {
151 put_ctx(ctx
->parent_ctx
);
152 ctx
->parent_ctx
= NULL
;
156 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
159 * only top level events have the pid namespace they were created in
162 event
= event
->parent
;
164 return task_tgid_nr_ns(p
, event
->ns
);
167 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
170 * only top level events have the pid namespace they were created in
173 event
= event
->parent
;
175 return task_pid_nr_ns(p
, event
->ns
);
179 * If we inherit events we want to return the parent event id
182 static u64
primary_event_id(struct perf_event
*event
)
187 id
= event
->parent
->id
;
193 * Get the perf_event_context for a task and lock it.
194 * This has to cope with with the fact that until it is locked,
195 * the context could get moved to another task.
197 static struct perf_event_context
*
198 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
200 struct perf_event_context
*ctx
;
204 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
207 * If this context is a clone of another, it might
208 * get swapped for another underneath us by
209 * perf_event_task_sched_out, though the
210 * rcu_read_lock() protects us from any context
211 * getting freed. Lock the context and check if it
212 * got swapped before we could get the lock, and retry
213 * if so. If we locked the right context, then it
214 * can't get swapped on us any more.
216 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
217 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
218 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
222 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
223 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
232 * Get the context for a task and increment its pin_count so it
233 * can't get swapped to another task. This also increments its
234 * reference count so that the context can't get freed.
236 static struct perf_event_context
*
237 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
239 struct perf_event_context
*ctx
;
242 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
245 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
250 static void perf_unpin_context(struct perf_event_context
*ctx
)
254 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
256 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
261 * Update the record of the current time in a context.
263 static void update_context_time(struct perf_event_context
*ctx
)
265 u64 now
= perf_clock();
267 ctx
->time
+= now
- ctx
->timestamp
;
268 ctx
->timestamp
= now
;
271 static u64
perf_event_time(struct perf_event
*event
)
273 struct perf_event_context
*ctx
= event
->ctx
;
274 return ctx
? ctx
->time
: 0;
278 * Update the total_time_enabled and total_time_running fields for a event.
280 static void update_event_times(struct perf_event
*event
)
282 struct perf_event_context
*ctx
= event
->ctx
;
285 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
286 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
290 run_end
= perf_event_time(event
);
292 run_end
= event
->tstamp_stopped
;
294 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
296 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
297 run_end
= event
->tstamp_stopped
;
299 run_end
= perf_event_time(event
);
301 event
->total_time_running
= run_end
- event
->tstamp_running
;
305 * Update total_time_enabled and total_time_running for all events in a group.
307 static void update_group_times(struct perf_event
*leader
)
309 struct perf_event
*event
;
311 update_event_times(leader
);
312 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
313 update_event_times(event
);
316 static struct list_head
*
317 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
319 if (event
->attr
.pinned
)
320 return &ctx
->pinned_groups
;
322 return &ctx
->flexible_groups
;
326 * Add a event from the lists for its context.
327 * Must be called with ctx->mutex and ctx->lock held.
330 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
332 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
333 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
336 * If we're a stand alone event or group leader, we go to the context
337 * list, group events are kept attached to the group so that
338 * perf_group_detach can, at all times, locate all siblings.
340 if (event
->group_leader
== event
) {
341 struct list_head
*list
;
343 if (is_software_event(event
))
344 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
346 list
= ctx_group_list(event
, ctx
);
347 list_add_tail(&event
->group_entry
, list
);
350 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
352 perf_pmu_rotate_start(ctx
->pmu
);
354 if (event
->attr
.inherit_stat
)
359 * Called at perf_event creation and when events are attached/detached from a
362 static void perf_event__read_size(struct perf_event
*event
)
364 int entry
= sizeof(u64
); /* value */
368 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
371 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
374 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
375 entry
+= sizeof(u64
);
377 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
378 nr
+= event
->group_leader
->nr_siblings
;
383 event
->read_size
= size
;
386 static void perf_event__header_size(struct perf_event
*event
)
388 struct perf_sample_data
*data
;
389 u64 sample_type
= event
->attr
.sample_type
;
392 perf_event__read_size(event
);
394 if (sample_type
& PERF_SAMPLE_IP
)
395 size
+= sizeof(data
->ip
);
397 if (sample_type
& PERF_SAMPLE_ADDR
)
398 size
+= sizeof(data
->addr
);
400 if (sample_type
& PERF_SAMPLE_PERIOD
)
401 size
+= sizeof(data
->period
);
403 if (sample_type
& PERF_SAMPLE_READ
)
404 size
+= event
->read_size
;
406 event
->header_size
= size
;
409 static void perf_event__id_header_size(struct perf_event
*event
)
411 struct perf_sample_data
*data
;
412 u64 sample_type
= event
->attr
.sample_type
;
415 if (sample_type
& PERF_SAMPLE_TID
)
416 size
+= sizeof(data
->tid_entry
);
418 if (sample_type
& PERF_SAMPLE_TIME
)
419 size
+= sizeof(data
->time
);
421 if (sample_type
& PERF_SAMPLE_ID
)
422 size
+= sizeof(data
->id
);
424 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
425 size
+= sizeof(data
->stream_id
);
427 if (sample_type
& PERF_SAMPLE_CPU
)
428 size
+= sizeof(data
->cpu_entry
);
430 event
->id_header_size
= size
;
433 static void perf_group_attach(struct perf_event
*event
)
435 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
438 * We can have double attach due to group movement in perf_event_open.
440 if (event
->attach_state
& PERF_ATTACH_GROUP
)
443 event
->attach_state
|= PERF_ATTACH_GROUP
;
445 if (group_leader
== event
)
448 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
449 !is_software_event(event
))
450 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
452 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
453 group_leader
->nr_siblings
++;
455 perf_event__header_size(group_leader
);
457 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
458 perf_event__header_size(pos
);
462 * Remove a event from the lists for its context.
463 * Must be called with ctx->mutex and ctx->lock held.
466 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
469 * We can have double detach due to exit/hot-unplug + close.
471 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
474 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
477 if (event
->attr
.inherit_stat
)
480 list_del_rcu(&event
->event_entry
);
482 if (event
->group_leader
== event
)
483 list_del_init(&event
->group_entry
);
485 update_group_times(event
);
488 * If event was in error state, then keep it
489 * that way, otherwise bogus counts will be
490 * returned on read(). The only way to get out
491 * of error state is by explicit re-enabling
494 if (event
->state
> PERF_EVENT_STATE_OFF
)
495 event
->state
= PERF_EVENT_STATE_OFF
;
498 static void perf_group_detach(struct perf_event
*event
)
500 struct perf_event
*sibling
, *tmp
;
501 struct list_head
*list
= NULL
;
504 * We can have double detach due to exit/hot-unplug + close.
506 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
509 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
512 * If this is a sibling, remove it from its group.
514 if (event
->group_leader
!= event
) {
515 list_del_init(&event
->group_entry
);
516 event
->group_leader
->nr_siblings
--;
520 if (!list_empty(&event
->group_entry
))
521 list
= &event
->group_entry
;
524 * If this was a group event with sibling events then
525 * upgrade the siblings to singleton events by adding them
526 * to whatever list we are on.
528 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
530 list_move_tail(&sibling
->group_entry
, list
);
531 sibling
->group_leader
= sibling
;
533 /* Inherit group flags from the previous leader */
534 sibling
->group_flags
= event
->group_flags
;
538 perf_event__header_size(event
->group_leader
);
540 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
541 perf_event__header_size(tmp
);
545 event_filter_match(struct perf_event
*event
)
547 return event
->cpu
== -1 || event
->cpu
== smp_processor_id();
551 event_sched_out(struct perf_event
*event
,
552 struct perf_cpu_context
*cpuctx
,
553 struct perf_event_context
*ctx
)
555 u64 tstamp
= perf_event_time(event
);
558 * An event which could not be activated because of
559 * filter mismatch still needs to have its timings
560 * maintained, otherwise bogus information is return
561 * via read() for time_enabled, time_running:
563 if (event
->state
== PERF_EVENT_STATE_INACTIVE
564 && !event_filter_match(event
)) {
565 delta
= ctx
->time
- event
->tstamp_stopped
;
566 event
->tstamp_running
+= delta
;
567 event
->tstamp_stopped
= tstamp
;
570 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
573 event
->state
= PERF_EVENT_STATE_INACTIVE
;
574 if (event
->pending_disable
) {
575 event
->pending_disable
= 0;
576 event
->state
= PERF_EVENT_STATE_OFF
;
578 event
->tstamp_stopped
= tstamp
;
579 event
->pmu
->del(event
, 0);
582 if (!is_software_event(event
))
583 cpuctx
->active_oncpu
--;
585 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
586 cpuctx
->exclusive
= 0;
590 group_sched_out(struct perf_event
*group_event
,
591 struct perf_cpu_context
*cpuctx
,
592 struct perf_event_context
*ctx
)
594 struct perf_event
*event
;
595 int state
= group_event
->state
;
597 event_sched_out(group_event
, cpuctx
, ctx
);
600 * Schedule out siblings (if any):
602 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
603 event_sched_out(event
, cpuctx
, ctx
);
605 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
606 cpuctx
->exclusive
= 0;
609 static inline struct perf_cpu_context
*
610 __get_cpu_context(struct perf_event_context
*ctx
)
612 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
616 * Cross CPU call to remove a performance event
618 * We disable the event on the hardware level first. After that we
619 * remove it from the context list.
621 static void __perf_event_remove_from_context(void *info
)
623 struct perf_event
*event
= info
;
624 struct perf_event_context
*ctx
= event
->ctx
;
625 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
628 * If this is a task context, we need to check whether it is
629 * the current task context of this cpu. If not it has been
630 * scheduled out before the smp call arrived.
632 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
635 raw_spin_lock(&ctx
->lock
);
637 event_sched_out(event
, cpuctx
, ctx
);
639 list_del_event(event
, ctx
);
641 raw_spin_unlock(&ctx
->lock
);
646 * Remove the event from a task's (or a CPU's) list of events.
648 * Must be called with ctx->mutex held.
650 * CPU events are removed with a smp call. For task events we only
651 * call when the task is on a CPU.
653 * If event->ctx is a cloned context, callers must make sure that
654 * every task struct that event->ctx->task could possibly point to
655 * remains valid. This is OK when called from perf_release since
656 * that only calls us on the top-level context, which can't be a clone.
657 * When called from perf_event_exit_task, it's OK because the
658 * context has been detached from its task.
660 static void perf_event_remove_from_context(struct perf_event
*event
)
662 struct perf_event_context
*ctx
= event
->ctx
;
663 struct task_struct
*task
= ctx
->task
;
667 * Per cpu events are removed via an smp call and
668 * the removal is always successful.
670 smp_call_function_single(event
->cpu
,
671 __perf_event_remove_from_context
,
677 task_oncpu_function_call(task
, __perf_event_remove_from_context
,
680 raw_spin_lock_irq(&ctx
->lock
);
682 * If the context is active we need to retry the smp call.
684 if (ctx
->nr_active
&& !list_empty(&event
->group_entry
)) {
685 raw_spin_unlock_irq(&ctx
->lock
);
690 * The lock prevents that this context is scheduled in so we
691 * can remove the event safely, if the call above did not
694 if (!list_empty(&event
->group_entry
))
695 list_del_event(event
, ctx
);
696 raw_spin_unlock_irq(&ctx
->lock
);
700 * Cross CPU call to disable a performance event
702 static void __perf_event_disable(void *info
)
704 struct perf_event
*event
= info
;
705 struct perf_event_context
*ctx
= event
->ctx
;
706 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
709 * If this is a per-task event, need to check whether this
710 * event's task is the current task on this cpu.
712 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
715 raw_spin_lock(&ctx
->lock
);
718 * If the event is on, turn it off.
719 * If it is in error state, leave it in error state.
721 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
722 update_context_time(ctx
);
723 update_group_times(event
);
724 if (event
== event
->group_leader
)
725 group_sched_out(event
, cpuctx
, ctx
);
727 event_sched_out(event
, cpuctx
, ctx
);
728 event
->state
= PERF_EVENT_STATE_OFF
;
731 raw_spin_unlock(&ctx
->lock
);
737 * If event->ctx is a cloned context, callers must make sure that
738 * every task struct that event->ctx->task could possibly point to
739 * remains valid. This condition is satisifed when called through
740 * perf_event_for_each_child or perf_event_for_each because they
741 * hold the top-level event's child_mutex, so any descendant that
742 * goes to exit will block in sync_child_event.
743 * When called from perf_pending_event it's OK because event->ctx
744 * is the current context on this CPU and preemption is disabled,
745 * hence we can't get into perf_event_task_sched_out for this context.
747 void perf_event_disable(struct perf_event
*event
)
749 struct perf_event_context
*ctx
= event
->ctx
;
750 struct task_struct
*task
= ctx
->task
;
754 * Disable the event on the cpu that it's on
756 smp_call_function_single(event
->cpu
, __perf_event_disable
,
762 task_oncpu_function_call(task
, __perf_event_disable
, event
);
764 raw_spin_lock_irq(&ctx
->lock
);
766 * If the event is still active, we need to retry the cross-call.
768 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
769 raw_spin_unlock_irq(&ctx
->lock
);
774 * Since we have the lock this context can't be scheduled
775 * in, so we can change the state safely.
777 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
778 update_group_times(event
);
779 event
->state
= PERF_EVENT_STATE_OFF
;
782 raw_spin_unlock_irq(&ctx
->lock
);
786 event_sched_in(struct perf_event
*event
,
787 struct perf_cpu_context
*cpuctx
,
788 struct perf_event_context
*ctx
)
790 u64 tstamp
= perf_event_time(event
);
792 if (event
->state
<= PERF_EVENT_STATE_OFF
)
795 event
->state
= PERF_EVENT_STATE_ACTIVE
;
796 event
->oncpu
= smp_processor_id();
798 * The new state must be visible before we turn it on in the hardware:
802 if (event
->pmu
->add(event
, PERF_EF_START
)) {
803 event
->state
= PERF_EVENT_STATE_INACTIVE
;
808 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
810 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
812 if (!is_software_event(event
))
813 cpuctx
->active_oncpu
++;
816 if (event
->attr
.exclusive
)
817 cpuctx
->exclusive
= 1;
823 group_sched_in(struct perf_event
*group_event
,
824 struct perf_cpu_context
*cpuctx
,
825 struct perf_event_context
*ctx
)
827 struct perf_event
*event
, *partial_group
= NULL
;
828 struct pmu
*pmu
= group_event
->pmu
;
830 bool simulate
= false;
832 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
837 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
838 pmu
->cancel_txn(pmu
);
843 * Schedule in siblings as one group (if any):
845 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
846 if (event_sched_in(event
, cpuctx
, ctx
)) {
847 partial_group
= event
;
852 if (!pmu
->commit_txn(pmu
))
857 * Groups can be scheduled in as one unit only, so undo any
858 * partial group before returning:
859 * The events up to the failed event are scheduled out normally,
860 * tstamp_stopped will be updated.
862 * The failed events and the remaining siblings need to have
863 * their timings updated as if they had gone thru event_sched_in()
864 * and event_sched_out(). This is required to get consistent timings
865 * across the group. This also takes care of the case where the group
866 * could never be scheduled by ensuring tstamp_stopped is set to mark
867 * the time the event was actually stopped, such that time delta
868 * calculation in update_event_times() is correct.
870 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
871 if (event
== partial_group
)
875 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
876 event
->tstamp_stopped
= now
;
878 event_sched_out(event
, cpuctx
, ctx
);
881 event_sched_out(group_event
, cpuctx
, ctx
);
883 pmu
->cancel_txn(pmu
);
889 * Work out whether we can put this event group on the CPU now.
891 static int group_can_go_on(struct perf_event
*event
,
892 struct perf_cpu_context
*cpuctx
,
896 * Groups consisting entirely of software events can always go on.
898 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
901 * If an exclusive group is already on, no other hardware
904 if (cpuctx
->exclusive
)
907 * If this group is exclusive and there are already
908 * events on the CPU, it can't go on.
910 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
913 * Otherwise, try to add it if all previous groups were able
919 static void add_event_to_ctx(struct perf_event
*event
,
920 struct perf_event_context
*ctx
)
922 u64 tstamp
= perf_event_time(event
);
924 list_add_event(event
, ctx
);
925 perf_group_attach(event
);
926 event
->tstamp_enabled
= tstamp
;
927 event
->tstamp_running
= tstamp
;
928 event
->tstamp_stopped
= tstamp
;
932 * Cross CPU call to install and enable a performance event
934 * Must be called with ctx->mutex held
936 static void __perf_install_in_context(void *info
)
938 struct perf_event
*event
= info
;
939 struct perf_event_context
*ctx
= event
->ctx
;
940 struct perf_event
*leader
= event
->group_leader
;
941 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
945 * If this is a task context, we need to check whether it is
946 * the current task context of this cpu. If not it has been
947 * scheduled out before the smp call arrived.
948 * Or possibly this is the right context but it isn't
949 * on this cpu because it had no events.
951 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
952 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
954 cpuctx
->task_ctx
= ctx
;
957 raw_spin_lock(&ctx
->lock
);
959 update_context_time(ctx
);
961 add_event_to_ctx(event
, ctx
);
963 if (!event_filter_match(event
))
967 * Don't put the event on if it is disabled or if
968 * it is in a group and the group isn't on.
970 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
971 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
975 * An exclusive event can't go on if there are already active
976 * hardware events, and no hardware event can go on if there
977 * is already an exclusive event on.
979 if (!group_can_go_on(event
, cpuctx
, 1))
982 err
= event_sched_in(event
, cpuctx
, ctx
);
986 * This event couldn't go on. If it is in a group
987 * then we have to pull the whole group off.
988 * If the event group is pinned then put it in error state.
991 group_sched_out(leader
, cpuctx
, ctx
);
992 if (leader
->attr
.pinned
) {
993 update_group_times(leader
);
994 leader
->state
= PERF_EVENT_STATE_ERROR
;
999 raw_spin_unlock(&ctx
->lock
);
1003 * Attach a performance event to a context
1005 * First we add the event to the list with the hardware enable bit
1006 * in event->hw_config cleared.
1008 * If the event is attached to a task which is on a CPU we use a smp
1009 * call to enable it in the task context. The task might have been
1010 * scheduled away, but we check this in the smp call again.
1012 * Must be called with ctx->mutex held.
1015 perf_install_in_context(struct perf_event_context
*ctx
,
1016 struct perf_event
*event
,
1019 struct task_struct
*task
= ctx
->task
;
1025 * Per cpu events are installed via an smp call and
1026 * the install is always successful.
1028 smp_call_function_single(cpu
, __perf_install_in_context
,
1034 task_oncpu_function_call(task
, __perf_install_in_context
,
1037 raw_spin_lock_irq(&ctx
->lock
);
1039 * we need to retry the smp call.
1041 if (ctx
->is_active
&& list_empty(&event
->group_entry
)) {
1042 raw_spin_unlock_irq(&ctx
->lock
);
1047 * The lock prevents that this context is scheduled in so we
1048 * can add the event safely, if it the call above did not
1051 if (list_empty(&event
->group_entry
))
1052 add_event_to_ctx(event
, ctx
);
1053 raw_spin_unlock_irq(&ctx
->lock
);
1057 * Put a event into inactive state and update time fields.
1058 * Enabling the leader of a group effectively enables all
1059 * the group members that aren't explicitly disabled, so we
1060 * have to update their ->tstamp_enabled also.
1061 * Note: this works for group members as well as group leaders
1062 * since the non-leader members' sibling_lists will be empty.
1064 static void __perf_event_mark_enabled(struct perf_event
*event
,
1065 struct perf_event_context
*ctx
)
1067 struct perf_event
*sub
;
1068 u64 tstamp
= perf_event_time(event
);
1070 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1071 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1072 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1073 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1074 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1079 * Cross CPU call to enable a performance event
1081 static void __perf_event_enable(void *info
)
1083 struct perf_event
*event
= info
;
1084 struct perf_event_context
*ctx
= event
->ctx
;
1085 struct perf_event
*leader
= event
->group_leader
;
1086 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1090 * If this is a per-task event, need to check whether this
1091 * event's task is the current task on this cpu.
1093 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
1094 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
1096 cpuctx
->task_ctx
= ctx
;
1099 raw_spin_lock(&ctx
->lock
);
1101 update_context_time(ctx
);
1103 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1105 __perf_event_mark_enabled(event
, ctx
);
1107 if (!event_filter_match(event
))
1111 * If the event is in a group and isn't the group leader,
1112 * then don't put it on unless the group is on.
1114 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1117 if (!group_can_go_on(event
, cpuctx
, 1)) {
1120 if (event
== leader
)
1121 err
= group_sched_in(event
, cpuctx
, ctx
);
1123 err
= event_sched_in(event
, cpuctx
, ctx
);
1128 * If this event can't go on and it's part of a
1129 * group, then the whole group has to come off.
1131 if (leader
!= event
)
1132 group_sched_out(leader
, cpuctx
, ctx
);
1133 if (leader
->attr
.pinned
) {
1134 update_group_times(leader
);
1135 leader
->state
= PERF_EVENT_STATE_ERROR
;
1140 raw_spin_unlock(&ctx
->lock
);
1146 * If event->ctx is a cloned context, callers must make sure that
1147 * every task struct that event->ctx->task could possibly point to
1148 * remains valid. This condition is satisfied when called through
1149 * perf_event_for_each_child or perf_event_for_each as described
1150 * for perf_event_disable.
1152 void perf_event_enable(struct perf_event
*event
)
1154 struct perf_event_context
*ctx
= event
->ctx
;
1155 struct task_struct
*task
= ctx
->task
;
1159 * Enable the event on the cpu that it's on
1161 smp_call_function_single(event
->cpu
, __perf_event_enable
,
1166 raw_spin_lock_irq(&ctx
->lock
);
1167 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1171 * If the event is in error state, clear that first.
1172 * That way, if we see the event in error state below, we
1173 * know that it has gone back into error state, as distinct
1174 * from the task having been scheduled away before the
1175 * cross-call arrived.
1177 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1178 event
->state
= PERF_EVENT_STATE_OFF
;
1181 raw_spin_unlock_irq(&ctx
->lock
);
1182 task_oncpu_function_call(task
, __perf_event_enable
, event
);
1184 raw_spin_lock_irq(&ctx
->lock
);
1187 * If the context is active and the event is still off,
1188 * we need to retry the cross-call.
1190 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
)
1194 * Since we have the lock this context can't be scheduled
1195 * in, so we can change the state safely.
1197 if (event
->state
== PERF_EVENT_STATE_OFF
)
1198 __perf_event_mark_enabled(event
, ctx
);
1201 raw_spin_unlock_irq(&ctx
->lock
);
1204 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1207 * not supported on inherited events
1209 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1212 atomic_add(refresh
, &event
->event_limit
);
1213 perf_event_enable(event
);
1218 static void ctx_sched_out(struct perf_event_context
*ctx
,
1219 struct perf_cpu_context
*cpuctx
,
1220 enum event_type_t event_type
)
1222 struct perf_event
*event
;
1224 raw_spin_lock(&ctx
->lock
);
1225 perf_pmu_disable(ctx
->pmu
);
1227 if (likely(!ctx
->nr_events
))
1229 update_context_time(ctx
);
1231 if (!ctx
->nr_active
)
1234 if (event_type
& EVENT_PINNED
) {
1235 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1236 group_sched_out(event
, cpuctx
, ctx
);
1239 if (event_type
& EVENT_FLEXIBLE
) {
1240 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1241 group_sched_out(event
, cpuctx
, ctx
);
1244 perf_pmu_enable(ctx
->pmu
);
1245 raw_spin_unlock(&ctx
->lock
);
1249 * Test whether two contexts are equivalent, i.e. whether they
1250 * have both been cloned from the same version of the same context
1251 * and they both have the same number of enabled events.
1252 * If the number of enabled events is the same, then the set
1253 * of enabled events should be the same, because these are both
1254 * inherited contexts, therefore we can't access individual events
1255 * in them directly with an fd; we can only enable/disable all
1256 * events via prctl, or enable/disable all events in a family
1257 * via ioctl, which will have the same effect on both contexts.
1259 static int context_equiv(struct perf_event_context
*ctx1
,
1260 struct perf_event_context
*ctx2
)
1262 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1263 && ctx1
->parent_gen
== ctx2
->parent_gen
1264 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1267 static void __perf_event_sync_stat(struct perf_event
*event
,
1268 struct perf_event
*next_event
)
1272 if (!event
->attr
.inherit_stat
)
1276 * Update the event value, we cannot use perf_event_read()
1277 * because we're in the middle of a context switch and have IRQs
1278 * disabled, which upsets smp_call_function_single(), however
1279 * we know the event must be on the current CPU, therefore we
1280 * don't need to use it.
1282 switch (event
->state
) {
1283 case PERF_EVENT_STATE_ACTIVE
:
1284 event
->pmu
->read(event
);
1287 case PERF_EVENT_STATE_INACTIVE
:
1288 update_event_times(event
);
1296 * In order to keep per-task stats reliable we need to flip the event
1297 * values when we flip the contexts.
1299 value
= local64_read(&next_event
->count
);
1300 value
= local64_xchg(&event
->count
, value
);
1301 local64_set(&next_event
->count
, value
);
1303 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1304 swap(event
->total_time_running
, next_event
->total_time_running
);
1307 * Since we swizzled the values, update the user visible data too.
1309 perf_event_update_userpage(event
);
1310 perf_event_update_userpage(next_event
);
1313 #define list_next_entry(pos, member) \
1314 list_entry(pos->member.next, typeof(*pos), member)
1316 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1317 struct perf_event_context
*next_ctx
)
1319 struct perf_event
*event
, *next_event
;
1324 update_context_time(ctx
);
1326 event
= list_first_entry(&ctx
->event_list
,
1327 struct perf_event
, event_entry
);
1329 next_event
= list_first_entry(&next_ctx
->event_list
,
1330 struct perf_event
, event_entry
);
1332 while (&event
->event_entry
!= &ctx
->event_list
&&
1333 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1335 __perf_event_sync_stat(event
, next_event
);
1337 event
= list_next_entry(event
, event_entry
);
1338 next_event
= list_next_entry(next_event
, event_entry
);
1342 void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
1343 struct task_struct
*next
)
1345 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
1346 struct perf_event_context
*next_ctx
;
1347 struct perf_event_context
*parent
;
1348 struct perf_cpu_context
*cpuctx
;
1354 cpuctx
= __get_cpu_context(ctx
);
1355 if (!cpuctx
->task_ctx
)
1359 parent
= rcu_dereference(ctx
->parent_ctx
);
1360 next_ctx
= next
->perf_event_ctxp
[ctxn
];
1361 if (parent
&& next_ctx
&&
1362 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1364 * Looks like the two contexts are clones, so we might be
1365 * able to optimize the context switch. We lock both
1366 * contexts and check that they are clones under the
1367 * lock (including re-checking that neither has been
1368 * uncloned in the meantime). It doesn't matter which
1369 * order we take the locks because no other cpu could
1370 * be trying to lock both of these tasks.
1372 raw_spin_lock(&ctx
->lock
);
1373 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1374 if (context_equiv(ctx
, next_ctx
)) {
1376 * XXX do we need a memory barrier of sorts
1377 * wrt to rcu_dereference() of perf_event_ctxp
1379 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
1380 next
->perf_event_ctxp
[ctxn
] = ctx
;
1382 next_ctx
->task
= task
;
1385 perf_event_sync_stat(ctx
, next_ctx
);
1387 raw_spin_unlock(&next_ctx
->lock
);
1388 raw_spin_unlock(&ctx
->lock
);
1393 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1394 cpuctx
->task_ctx
= NULL
;
1398 #define for_each_task_context_nr(ctxn) \
1399 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
1402 * Called from scheduler to remove the events of the current task,
1403 * with interrupts disabled.
1405 * We stop each event and update the event value in event->count.
1407 * This does not protect us against NMI, but disable()
1408 * sets the disabled bit in the control field of event _before_
1409 * accessing the event control register. If a NMI hits, then it will
1410 * not restart the event.
1412 void __perf_event_task_sched_out(struct task_struct
*task
,
1413 struct task_struct
*next
)
1417 for_each_task_context_nr(ctxn
)
1418 perf_event_context_sched_out(task
, ctxn
, next
);
1421 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1422 enum event_type_t event_type
)
1424 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1426 if (!cpuctx
->task_ctx
)
1429 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1432 ctx_sched_out(ctx
, cpuctx
, event_type
);
1433 cpuctx
->task_ctx
= NULL
;
1437 * Called with IRQs disabled
1439 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1440 enum event_type_t event_type
)
1442 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1446 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1447 struct perf_cpu_context
*cpuctx
)
1449 struct perf_event
*event
;
1451 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1452 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1454 if (!event_filter_match(event
))
1457 if (group_can_go_on(event
, cpuctx
, 1))
1458 group_sched_in(event
, cpuctx
, ctx
);
1461 * If this pinned group hasn't been scheduled,
1462 * put it in error state.
1464 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1465 update_group_times(event
);
1466 event
->state
= PERF_EVENT_STATE_ERROR
;
1472 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
1473 struct perf_cpu_context
*cpuctx
)
1475 struct perf_event
*event
;
1478 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1479 /* Ignore events in OFF or ERROR state */
1480 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1483 * Listen to the 'cpu' scheduling filter constraint
1486 if (!event_filter_match(event
))
1489 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
1490 if (group_sched_in(event
, cpuctx
, ctx
))
1497 ctx_sched_in(struct perf_event_context
*ctx
,
1498 struct perf_cpu_context
*cpuctx
,
1499 enum event_type_t event_type
)
1501 raw_spin_lock(&ctx
->lock
);
1503 if (likely(!ctx
->nr_events
))
1506 ctx
->timestamp
= perf_clock();
1509 * First go through the list and put on any pinned groups
1510 * in order to give them the best chance of going on.
1512 if (event_type
& EVENT_PINNED
)
1513 ctx_pinned_sched_in(ctx
, cpuctx
);
1515 /* Then walk through the lower prio flexible groups */
1516 if (event_type
& EVENT_FLEXIBLE
)
1517 ctx_flexible_sched_in(ctx
, cpuctx
);
1520 raw_spin_unlock(&ctx
->lock
);
1523 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
1524 enum event_type_t event_type
)
1526 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
1528 ctx_sched_in(ctx
, cpuctx
, event_type
);
1531 static void task_ctx_sched_in(struct perf_event_context
*ctx
,
1532 enum event_type_t event_type
)
1534 struct perf_cpu_context
*cpuctx
;
1536 cpuctx
= __get_cpu_context(ctx
);
1537 if (cpuctx
->task_ctx
== ctx
)
1540 ctx_sched_in(ctx
, cpuctx
, event_type
);
1541 cpuctx
->task_ctx
= ctx
;
1544 void perf_event_context_sched_in(struct perf_event_context
*ctx
)
1546 struct perf_cpu_context
*cpuctx
;
1548 cpuctx
= __get_cpu_context(ctx
);
1549 if (cpuctx
->task_ctx
== ctx
)
1552 perf_pmu_disable(ctx
->pmu
);
1554 * We want to keep the following priority order:
1555 * cpu pinned (that don't need to move), task pinned,
1556 * cpu flexible, task flexible.
1558 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1560 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
);
1561 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1562 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
);
1564 cpuctx
->task_ctx
= ctx
;
1567 * Since these rotations are per-cpu, we need to ensure the
1568 * cpu-context we got scheduled on is actually rotating.
1570 perf_pmu_rotate_start(ctx
->pmu
);
1571 perf_pmu_enable(ctx
->pmu
);
1575 * Called from scheduler to add the events of the current task
1576 * with interrupts disabled.
1578 * We restore the event value and then enable it.
1580 * This does not protect us against NMI, but enable()
1581 * sets the enabled bit in the control field of event _before_
1582 * accessing the event control register. If a NMI hits, then it will
1583 * keep the event running.
1585 void __perf_event_task_sched_in(struct task_struct
*task
)
1587 struct perf_event_context
*ctx
;
1590 for_each_task_context_nr(ctxn
) {
1591 ctx
= task
->perf_event_ctxp
[ctxn
];
1595 perf_event_context_sched_in(ctx
);
1599 #define MAX_INTERRUPTS (~0ULL)
1601 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1603 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1605 u64 frequency
= event
->attr
.sample_freq
;
1606 u64 sec
= NSEC_PER_SEC
;
1607 u64 divisor
, dividend
;
1609 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
1611 count_fls
= fls64(count
);
1612 nsec_fls
= fls64(nsec
);
1613 frequency_fls
= fls64(frequency
);
1617 * We got @count in @nsec, with a target of sample_freq HZ
1618 * the target period becomes:
1621 * period = -------------------
1622 * @nsec * sample_freq
1627 * Reduce accuracy by one bit such that @a and @b converge
1628 * to a similar magnitude.
1630 #define REDUCE_FLS(a, b) \
1632 if (a##_fls > b##_fls) { \
1642 * Reduce accuracy until either term fits in a u64, then proceed with
1643 * the other, so that finally we can do a u64/u64 division.
1645 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
1646 REDUCE_FLS(nsec
, frequency
);
1647 REDUCE_FLS(sec
, count
);
1650 if (count_fls
+ sec_fls
> 64) {
1651 divisor
= nsec
* frequency
;
1653 while (count_fls
+ sec_fls
> 64) {
1654 REDUCE_FLS(count
, sec
);
1658 dividend
= count
* sec
;
1660 dividend
= count
* sec
;
1662 while (nsec_fls
+ frequency_fls
> 64) {
1663 REDUCE_FLS(nsec
, frequency
);
1667 divisor
= nsec
* frequency
;
1673 return div64_u64(dividend
, divisor
);
1676 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1678 struct hw_perf_event
*hwc
= &event
->hw
;
1679 s64 period
, sample_period
;
1682 period
= perf_calculate_period(event
, nsec
, count
);
1684 delta
= (s64
)(period
- hwc
->sample_period
);
1685 delta
= (delta
+ 7) / 8; /* low pass filter */
1687 sample_period
= hwc
->sample_period
+ delta
;
1692 hwc
->sample_period
= sample_period
;
1694 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
1695 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
1696 local64_set(&hwc
->period_left
, 0);
1697 event
->pmu
->start(event
, PERF_EF_RELOAD
);
1701 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
, u64 period
)
1703 struct perf_event
*event
;
1704 struct hw_perf_event
*hwc
;
1705 u64 interrupts
, now
;
1708 raw_spin_lock(&ctx
->lock
);
1709 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
1710 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1713 if (!event_filter_match(event
))
1718 interrupts
= hwc
->interrupts
;
1719 hwc
->interrupts
= 0;
1722 * unthrottle events on the tick
1724 if (interrupts
== MAX_INTERRUPTS
) {
1725 perf_log_throttle(event
, 1);
1726 event
->pmu
->start(event
, 0);
1729 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
1732 event
->pmu
->read(event
);
1733 now
= local64_read(&event
->count
);
1734 delta
= now
- hwc
->freq_count_stamp
;
1735 hwc
->freq_count_stamp
= now
;
1738 perf_adjust_period(event
, period
, delta
);
1740 raw_spin_unlock(&ctx
->lock
);
1744 * Round-robin a context's events:
1746 static void rotate_ctx(struct perf_event_context
*ctx
)
1748 raw_spin_lock(&ctx
->lock
);
1751 * Rotate the first entry last of non-pinned groups. Rotation might be
1752 * disabled by the inheritance code.
1754 if (!ctx
->rotate_disable
)
1755 list_rotate_left(&ctx
->flexible_groups
);
1757 raw_spin_unlock(&ctx
->lock
);
1761 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
1762 * because they're strictly cpu affine and rotate_start is called with IRQs
1763 * disabled, while rotate_context is called from IRQ context.
1765 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
1767 u64 interval
= (u64
)cpuctx
->jiffies_interval
* TICK_NSEC
;
1768 struct perf_event_context
*ctx
= NULL
;
1769 int rotate
= 0, remove
= 1;
1771 if (cpuctx
->ctx
.nr_events
) {
1773 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
1777 ctx
= cpuctx
->task_ctx
;
1778 if (ctx
&& ctx
->nr_events
) {
1780 if (ctx
->nr_events
!= ctx
->nr_active
)
1784 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1785 perf_ctx_adjust_freq(&cpuctx
->ctx
, interval
);
1787 perf_ctx_adjust_freq(ctx
, interval
);
1792 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1794 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
1796 rotate_ctx(&cpuctx
->ctx
);
1800 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1802 task_ctx_sched_in(ctx
, EVENT_FLEXIBLE
);
1806 list_del_init(&cpuctx
->rotation_list
);
1808 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1811 void perf_event_task_tick(void)
1813 struct list_head
*head
= &__get_cpu_var(rotation_list
);
1814 struct perf_cpu_context
*cpuctx
, *tmp
;
1816 WARN_ON(!irqs_disabled());
1818 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
1819 if (cpuctx
->jiffies_interval
== 1 ||
1820 !(jiffies
% cpuctx
->jiffies_interval
))
1821 perf_rotate_context(cpuctx
);
1825 static int event_enable_on_exec(struct perf_event
*event
,
1826 struct perf_event_context
*ctx
)
1828 if (!event
->attr
.enable_on_exec
)
1831 event
->attr
.enable_on_exec
= 0;
1832 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1835 __perf_event_mark_enabled(event
, ctx
);
1841 * Enable all of a task's events that have been marked enable-on-exec.
1842 * This expects task == current.
1844 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
1846 struct perf_event
*event
;
1847 unsigned long flags
;
1851 local_irq_save(flags
);
1852 if (!ctx
|| !ctx
->nr_events
)
1855 task_ctx_sched_out(ctx
, EVENT_ALL
);
1857 raw_spin_lock(&ctx
->lock
);
1859 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1860 ret
= event_enable_on_exec(event
, ctx
);
1865 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1866 ret
= event_enable_on_exec(event
, ctx
);
1872 * Unclone this context if we enabled any event.
1877 raw_spin_unlock(&ctx
->lock
);
1879 perf_event_context_sched_in(ctx
);
1881 local_irq_restore(flags
);
1885 * Cross CPU call to read the hardware event
1887 static void __perf_event_read(void *info
)
1889 struct perf_event
*event
= info
;
1890 struct perf_event_context
*ctx
= event
->ctx
;
1891 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1894 * If this is a task context, we need to check whether it is
1895 * the current task context of this cpu. If not it has been
1896 * scheduled out before the smp call arrived. In that case
1897 * event->count would have been updated to a recent sample
1898 * when the event was scheduled out.
1900 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1903 raw_spin_lock(&ctx
->lock
);
1904 update_context_time(ctx
);
1905 update_event_times(event
);
1906 raw_spin_unlock(&ctx
->lock
);
1908 event
->pmu
->read(event
);
1911 static inline u64
perf_event_count(struct perf_event
*event
)
1913 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
1916 static u64
perf_event_read(struct perf_event
*event
)
1919 * If event is enabled and currently active on a CPU, update the
1920 * value in the event structure:
1922 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1923 smp_call_function_single(event
->oncpu
,
1924 __perf_event_read
, event
, 1);
1925 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1926 struct perf_event_context
*ctx
= event
->ctx
;
1927 unsigned long flags
;
1929 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1931 * may read while context is not active
1932 * (e.g., thread is blocked), in that case
1933 * we cannot update context time
1936 update_context_time(ctx
);
1937 update_event_times(event
);
1938 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1941 return perf_event_count(event
);
1948 struct callchain_cpus_entries
{
1949 struct rcu_head rcu_head
;
1950 struct perf_callchain_entry
*cpu_entries
[0];
1953 static DEFINE_PER_CPU(int, callchain_recursion
[PERF_NR_CONTEXTS
]);
1954 static atomic_t nr_callchain_events
;
1955 static DEFINE_MUTEX(callchain_mutex
);
1956 struct callchain_cpus_entries
*callchain_cpus_entries
;
1959 __weak
void perf_callchain_kernel(struct perf_callchain_entry
*entry
,
1960 struct pt_regs
*regs
)
1964 __weak
void perf_callchain_user(struct perf_callchain_entry
*entry
,
1965 struct pt_regs
*regs
)
1969 static void release_callchain_buffers_rcu(struct rcu_head
*head
)
1971 struct callchain_cpus_entries
*entries
;
1974 entries
= container_of(head
, struct callchain_cpus_entries
, rcu_head
);
1976 for_each_possible_cpu(cpu
)
1977 kfree(entries
->cpu_entries
[cpu
]);
1982 static void release_callchain_buffers(void)
1984 struct callchain_cpus_entries
*entries
;
1986 entries
= callchain_cpus_entries
;
1987 rcu_assign_pointer(callchain_cpus_entries
, NULL
);
1988 call_rcu(&entries
->rcu_head
, release_callchain_buffers_rcu
);
1991 static int alloc_callchain_buffers(void)
1995 struct callchain_cpus_entries
*entries
;
1998 * We can't use the percpu allocation API for data that can be
1999 * accessed from NMI. Use a temporary manual per cpu allocation
2000 * until that gets sorted out.
2002 size
= sizeof(*entries
) + sizeof(struct perf_callchain_entry
*) *
2003 num_possible_cpus();
2005 entries
= kzalloc(size
, GFP_KERNEL
);
2009 size
= sizeof(struct perf_callchain_entry
) * PERF_NR_CONTEXTS
;
2011 for_each_possible_cpu(cpu
) {
2012 entries
->cpu_entries
[cpu
] = kmalloc_node(size
, GFP_KERNEL
,
2014 if (!entries
->cpu_entries
[cpu
])
2018 rcu_assign_pointer(callchain_cpus_entries
, entries
);
2023 for_each_possible_cpu(cpu
)
2024 kfree(entries
->cpu_entries
[cpu
]);
2030 static int get_callchain_buffers(void)
2035 mutex_lock(&callchain_mutex
);
2037 count
= atomic_inc_return(&nr_callchain_events
);
2038 if (WARN_ON_ONCE(count
< 1)) {
2044 /* If the allocation failed, give up */
2045 if (!callchain_cpus_entries
)
2050 err
= alloc_callchain_buffers();
2052 release_callchain_buffers();
2054 mutex_unlock(&callchain_mutex
);
2059 static void put_callchain_buffers(void)
2061 if (atomic_dec_and_mutex_lock(&nr_callchain_events
, &callchain_mutex
)) {
2062 release_callchain_buffers();
2063 mutex_unlock(&callchain_mutex
);
2067 static int get_recursion_context(int *recursion
)
2075 else if (in_softirq())
2080 if (recursion
[rctx
])
2089 static inline void put_recursion_context(int *recursion
, int rctx
)
2095 static struct perf_callchain_entry
*get_callchain_entry(int *rctx
)
2098 struct callchain_cpus_entries
*entries
;
2100 *rctx
= get_recursion_context(__get_cpu_var(callchain_recursion
));
2104 entries
= rcu_dereference(callchain_cpus_entries
);
2108 cpu
= smp_processor_id();
2110 return &entries
->cpu_entries
[cpu
][*rctx
];
2114 put_callchain_entry(int rctx
)
2116 put_recursion_context(__get_cpu_var(callchain_recursion
), rctx
);
2119 static struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2122 struct perf_callchain_entry
*entry
;
2125 entry
= get_callchain_entry(&rctx
);
2134 if (!user_mode(regs
)) {
2135 perf_callchain_store(entry
, PERF_CONTEXT_KERNEL
);
2136 perf_callchain_kernel(entry
, regs
);
2138 regs
= task_pt_regs(current
);
2144 perf_callchain_store(entry
, PERF_CONTEXT_USER
);
2145 perf_callchain_user(entry
, regs
);
2149 put_callchain_entry(rctx
);
2155 * Initialize the perf_event context in a task_struct:
2157 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2159 raw_spin_lock_init(&ctx
->lock
);
2160 mutex_init(&ctx
->mutex
);
2161 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2162 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2163 INIT_LIST_HEAD(&ctx
->event_list
);
2164 atomic_set(&ctx
->refcount
, 1);
2167 static struct perf_event_context
*
2168 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2170 struct perf_event_context
*ctx
;
2172 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2176 __perf_event_init_context(ctx
);
2179 get_task_struct(task
);
2186 static struct task_struct
*
2187 find_lively_task_by_vpid(pid_t vpid
)
2189 struct task_struct
*task
;
2196 task
= find_task_by_vpid(vpid
);
2198 get_task_struct(task
);
2202 return ERR_PTR(-ESRCH
);
2205 * Can't attach events to a dying task.
2208 if (task
->flags
& PF_EXITING
)
2211 /* Reuse ptrace permission checks for now. */
2213 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2218 put_task_struct(task
);
2219 return ERR_PTR(err
);
2223 static struct perf_event_context
*
2224 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2226 struct perf_event_context
*ctx
;
2227 struct perf_cpu_context
*cpuctx
;
2228 unsigned long flags
;
2232 /* Must be root to operate on a CPU event: */
2233 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2234 return ERR_PTR(-EACCES
);
2237 * We could be clever and allow to attach a event to an
2238 * offline CPU and activate it when the CPU comes up, but
2241 if (!cpu_online(cpu
))
2242 return ERR_PTR(-ENODEV
);
2244 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2252 ctxn
= pmu
->task_ctx_nr
;
2257 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2260 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2264 ctx
= alloc_perf_context(pmu
, task
);
2271 if (cmpxchg(&task
->perf_event_ctxp
[ctxn
], NULL
, ctx
)) {
2273 * We raced with some other task; use
2274 * the context they set.
2276 put_task_struct(task
);
2285 return ERR_PTR(err
);
2288 static void perf_event_free_filter(struct perf_event
*event
);
2290 static void free_event_rcu(struct rcu_head
*head
)
2292 struct perf_event
*event
;
2294 event
= container_of(head
, struct perf_event
, rcu_head
);
2296 put_pid_ns(event
->ns
);
2297 perf_event_free_filter(event
);
2301 static void perf_buffer_put(struct perf_buffer
*buffer
);
2303 static void free_event(struct perf_event
*event
)
2305 irq_work_sync(&event
->pending
);
2307 if (!event
->parent
) {
2308 if (event
->attach_state
& PERF_ATTACH_TASK
)
2309 jump_label_dec(&perf_task_events
);
2310 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2311 atomic_dec(&nr_mmap_events
);
2312 if (event
->attr
.comm
)
2313 atomic_dec(&nr_comm_events
);
2314 if (event
->attr
.task
)
2315 atomic_dec(&nr_task_events
);
2316 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2317 put_callchain_buffers();
2320 if (event
->buffer
) {
2321 perf_buffer_put(event
->buffer
);
2322 event
->buffer
= NULL
;
2326 event
->destroy(event
);
2329 put_ctx(event
->ctx
);
2331 call_rcu(&event
->rcu_head
, free_event_rcu
);
2334 int perf_event_release_kernel(struct perf_event
*event
)
2336 struct perf_event_context
*ctx
= event
->ctx
;
2339 * Remove from the PMU, can't get re-enabled since we got
2340 * here because the last ref went.
2342 perf_event_disable(event
);
2344 WARN_ON_ONCE(ctx
->parent_ctx
);
2346 * There are two ways this annotation is useful:
2348 * 1) there is a lock recursion from perf_event_exit_task
2349 * see the comment there.
2351 * 2) there is a lock-inversion with mmap_sem through
2352 * perf_event_read_group(), which takes faults while
2353 * holding ctx->mutex, however this is called after
2354 * the last filedesc died, so there is no possibility
2355 * to trigger the AB-BA case.
2357 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2358 raw_spin_lock_irq(&ctx
->lock
);
2359 perf_group_detach(event
);
2360 list_del_event(event
, ctx
);
2361 raw_spin_unlock_irq(&ctx
->lock
);
2362 mutex_unlock(&ctx
->mutex
);
2368 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2371 * Called when the last reference to the file is gone.
2373 static int perf_release(struct inode
*inode
, struct file
*file
)
2375 struct perf_event
*event
= file
->private_data
;
2376 struct task_struct
*owner
;
2378 file
->private_data
= NULL
;
2381 owner
= ACCESS_ONCE(event
->owner
);
2383 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2384 * !owner it means the list deletion is complete and we can indeed
2385 * free this event, otherwise we need to serialize on
2386 * owner->perf_event_mutex.
2388 smp_read_barrier_depends();
2391 * Since delayed_put_task_struct() also drops the last
2392 * task reference we can safely take a new reference
2393 * while holding the rcu_read_lock().
2395 get_task_struct(owner
);
2400 mutex_lock(&owner
->perf_event_mutex
);
2402 * We have to re-check the event->owner field, if it is cleared
2403 * we raced with perf_event_exit_task(), acquiring the mutex
2404 * ensured they're done, and we can proceed with freeing the
2408 list_del_init(&event
->owner_entry
);
2409 mutex_unlock(&owner
->perf_event_mutex
);
2410 put_task_struct(owner
);
2413 return perf_event_release_kernel(event
);
2416 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
2418 struct perf_event
*child
;
2424 mutex_lock(&event
->child_mutex
);
2425 total
+= perf_event_read(event
);
2426 *enabled
+= event
->total_time_enabled
+
2427 atomic64_read(&event
->child_total_time_enabled
);
2428 *running
+= event
->total_time_running
+
2429 atomic64_read(&event
->child_total_time_running
);
2431 list_for_each_entry(child
, &event
->child_list
, child_list
) {
2432 total
+= perf_event_read(child
);
2433 *enabled
+= child
->total_time_enabled
;
2434 *running
+= child
->total_time_running
;
2436 mutex_unlock(&event
->child_mutex
);
2440 EXPORT_SYMBOL_GPL(perf_event_read_value
);
2442 static int perf_event_read_group(struct perf_event
*event
,
2443 u64 read_format
, char __user
*buf
)
2445 struct perf_event
*leader
= event
->group_leader
, *sub
;
2446 int n
= 0, size
= 0, ret
= -EFAULT
;
2447 struct perf_event_context
*ctx
= leader
->ctx
;
2449 u64 count
, enabled
, running
;
2451 mutex_lock(&ctx
->mutex
);
2452 count
= perf_event_read_value(leader
, &enabled
, &running
);
2454 values
[n
++] = 1 + leader
->nr_siblings
;
2455 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2456 values
[n
++] = enabled
;
2457 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2458 values
[n
++] = running
;
2459 values
[n
++] = count
;
2460 if (read_format
& PERF_FORMAT_ID
)
2461 values
[n
++] = primary_event_id(leader
);
2463 size
= n
* sizeof(u64
);
2465 if (copy_to_user(buf
, values
, size
))
2470 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
2473 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
2474 if (read_format
& PERF_FORMAT_ID
)
2475 values
[n
++] = primary_event_id(sub
);
2477 size
= n
* sizeof(u64
);
2479 if (copy_to_user(buf
+ ret
, values
, size
)) {
2487 mutex_unlock(&ctx
->mutex
);
2492 static int perf_event_read_one(struct perf_event
*event
,
2493 u64 read_format
, char __user
*buf
)
2495 u64 enabled
, running
;
2499 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
2500 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2501 values
[n
++] = enabled
;
2502 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2503 values
[n
++] = running
;
2504 if (read_format
& PERF_FORMAT_ID
)
2505 values
[n
++] = primary_event_id(event
);
2507 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2510 return n
* sizeof(u64
);
2514 * Read the performance event - simple non blocking version for now
2517 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2519 u64 read_format
= event
->attr
.read_format
;
2523 * Return end-of-file for a read on a event that is in
2524 * error state (i.e. because it was pinned but it couldn't be
2525 * scheduled on to the CPU at some point).
2527 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2530 if (count
< event
->read_size
)
2533 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2534 if (read_format
& PERF_FORMAT_GROUP
)
2535 ret
= perf_event_read_group(event
, read_format
, buf
);
2537 ret
= perf_event_read_one(event
, read_format
, buf
);
2543 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2545 struct perf_event
*event
= file
->private_data
;
2547 return perf_read_hw(event
, buf
, count
);
2550 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2552 struct perf_event
*event
= file
->private_data
;
2553 struct perf_buffer
*buffer
;
2554 unsigned int events
= POLL_HUP
;
2557 buffer
= rcu_dereference(event
->buffer
);
2559 events
= atomic_xchg(&buffer
->poll
, 0);
2562 poll_wait(file
, &event
->waitq
, wait
);
2567 static void perf_event_reset(struct perf_event
*event
)
2569 (void)perf_event_read(event
);
2570 local64_set(&event
->count
, 0);
2571 perf_event_update_userpage(event
);
2575 * Holding the top-level event's child_mutex means that any
2576 * descendant process that has inherited this event will block
2577 * in sync_child_event if it goes to exit, thus satisfying the
2578 * task existence requirements of perf_event_enable/disable.
2580 static void perf_event_for_each_child(struct perf_event
*event
,
2581 void (*func
)(struct perf_event
*))
2583 struct perf_event
*child
;
2585 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2586 mutex_lock(&event
->child_mutex
);
2588 list_for_each_entry(child
, &event
->child_list
, child_list
)
2590 mutex_unlock(&event
->child_mutex
);
2593 static void perf_event_for_each(struct perf_event
*event
,
2594 void (*func
)(struct perf_event
*))
2596 struct perf_event_context
*ctx
= event
->ctx
;
2597 struct perf_event
*sibling
;
2599 WARN_ON_ONCE(ctx
->parent_ctx
);
2600 mutex_lock(&ctx
->mutex
);
2601 event
= event
->group_leader
;
2603 perf_event_for_each_child(event
, func
);
2605 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
2606 perf_event_for_each_child(event
, func
);
2607 mutex_unlock(&ctx
->mutex
);
2610 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
2612 struct perf_event_context
*ctx
= event
->ctx
;
2616 if (!is_sampling_event(event
))
2619 if (copy_from_user(&value
, arg
, sizeof(value
)))
2625 raw_spin_lock_irq(&ctx
->lock
);
2626 if (event
->attr
.freq
) {
2627 if (value
> sysctl_perf_event_sample_rate
) {
2632 event
->attr
.sample_freq
= value
;
2634 event
->attr
.sample_period
= value
;
2635 event
->hw
.sample_period
= value
;
2638 raw_spin_unlock_irq(&ctx
->lock
);
2643 static const struct file_operations perf_fops
;
2645 static struct perf_event
*perf_fget_light(int fd
, int *fput_needed
)
2649 file
= fget_light(fd
, fput_needed
);
2651 return ERR_PTR(-EBADF
);
2653 if (file
->f_op
!= &perf_fops
) {
2654 fput_light(file
, *fput_needed
);
2656 return ERR_PTR(-EBADF
);
2659 return file
->private_data
;
2662 static int perf_event_set_output(struct perf_event
*event
,
2663 struct perf_event
*output_event
);
2664 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
2666 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2668 struct perf_event
*event
= file
->private_data
;
2669 void (*func
)(struct perf_event
*);
2673 case PERF_EVENT_IOC_ENABLE
:
2674 func
= perf_event_enable
;
2676 case PERF_EVENT_IOC_DISABLE
:
2677 func
= perf_event_disable
;
2679 case PERF_EVENT_IOC_RESET
:
2680 func
= perf_event_reset
;
2683 case PERF_EVENT_IOC_REFRESH
:
2684 return perf_event_refresh(event
, arg
);
2686 case PERF_EVENT_IOC_PERIOD
:
2687 return perf_event_period(event
, (u64 __user
*)arg
);
2689 case PERF_EVENT_IOC_SET_OUTPUT
:
2691 struct perf_event
*output_event
= NULL
;
2692 int fput_needed
= 0;
2696 output_event
= perf_fget_light(arg
, &fput_needed
);
2697 if (IS_ERR(output_event
))
2698 return PTR_ERR(output_event
);
2701 ret
= perf_event_set_output(event
, output_event
);
2703 fput_light(output_event
->filp
, fput_needed
);
2708 case PERF_EVENT_IOC_SET_FILTER
:
2709 return perf_event_set_filter(event
, (void __user
*)arg
);
2715 if (flags
& PERF_IOC_FLAG_GROUP
)
2716 perf_event_for_each(event
, func
);
2718 perf_event_for_each_child(event
, func
);
2723 int perf_event_task_enable(void)
2725 struct perf_event
*event
;
2727 mutex_lock(¤t
->perf_event_mutex
);
2728 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2729 perf_event_for_each_child(event
, perf_event_enable
);
2730 mutex_unlock(¤t
->perf_event_mutex
);
2735 int perf_event_task_disable(void)
2737 struct perf_event
*event
;
2739 mutex_lock(¤t
->perf_event_mutex
);
2740 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2741 perf_event_for_each_child(event
, perf_event_disable
);
2742 mutex_unlock(¤t
->perf_event_mutex
);
2747 #ifndef PERF_EVENT_INDEX_OFFSET
2748 # define PERF_EVENT_INDEX_OFFSET 0
2751 static int perf_event_index(struct perf_event
*event
)
2753 if (event
->hw
.state
& PERF_HES_STOPPED
)
2756 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2759 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
2763 * Callers need to ensure there can be no nesting of this function, otherwise
2764 * the seqlock logic goes bad. We can not serialize this because the arch
2765 * code calls this from NMI context.
2767 void perf_event_update_userpage(struct perf_event
*event
)
2769 struct perf_event_mmap_page
*userpg
;
2770 struct perf_buffer
*buffer
;
2773 buffer
= rcu_dereference(event
->buffer
);
2777 userpg
= buffer
->user_page
;
2780 * Disable preemption so as to not let the corresponding user-space
2781 * spin too long if we get preempted.
2786 userpg
->index
= perf_event_index(event
);
2787 userpg
->offset
= perf_event_count(event
);
2788 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2789 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
2791 userpg
->time_enabled
= event
->total_time_enabled
+
2792 atomic64_read(&event
->child_total_time_enabled
);
2794 userpg
->time_running
= event
->total_time_running
+
2795 atomic64_read(&event
->child_total_time_running
);
2804 static unsigned long perf_data_size(struct perf_buffer
*buffer
);
2807 perf_buffer_init(struct perf_buffer
*buffer
, long watermark
, int flags
)
2809 long max_size
= perf_data_size(buffer
);
2812 buffer
->watermark
= min(max_size
, watermark
);
2814 if (!buffer
->watermark
)
2815 buffer
->watermark
= max_size
/ 2;
2817 if (flags
& PERF_BUFFER_WRITABLE
)
2818 buffer
->writable
= 1;
2820 atomic_set(&buffer
->refcount
, 1);
2823 #ifndef CONFIG_PERF_USE_VMALLOC
2826 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
2829 static struct page
*
2830 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
2832 if (pgoff
> buffer
->nr_pages
)
2836 return virt_to_page(buffer
->user_page
);
2838 return virt_to_page(buffer
->data_pages
[pgoff
- 1]);
2841 static void *perf_mmap_alloc_page(int cpu
)
2846 node
= (cpu
== -1) ? cpu
: cpu_to_node(cpu
);
2847 page
= alloc_pages_node(node
, GFP_KERNEL
| __GFP_ZERO
, 0);
2851 return page_address(page
);
2854 static struct perf_buffer
*
2855 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
2857 struct perf_buffer
*buffer
;
2861 size
= sizeof(struct perf_buffer
);
2862 size
+= nr_pages
* sizeof(void *);
2864 buffer
= kzalloc(size
, GFP_KERNEL
);
2868 buffer
->user_page
= perf_mmap_alloc_page(cpu
);
2869 if (!buffer
->user_page
)
2870 goto fail_user_page
;
2872 for (i
= 0; i
< nr_pages
; i
++) {
2873 buffer
->data_pages
[i
] = perf_mmap_alloc_page(cpu
);
2874 if (!buffer
->data_pages
[i
])
2875 goto fail_data_pages
;
2878 buffer
->nr_pages
= nr_pages
;
2880 perf_buffer_init(buffer
, watermark
, flags
);
2885 for (i
--; i
>= 0; i
--)
2886 free_page((unsigned long)buffer
->data_pages
[i
]);
2888 free_page((unsigned long)buffer
->user_page
);
2897 static void perf_mmap_free_page(unsigned long addr
)
2899 struct page
*page
= virt_to_page((void *)addr
);
2901 page
->mapping
= NULL
;
2905 static void perf_buffer_free(struct perf_buffer
*buffer
)
2909 perf_mmap_free_page((unsigned long)buffer
->user_page
);
2910 for (i
= 0; i
< buffer
->nr_pages
; i
++)
2911 perf_mmap_free_page((unsigned long)buffer
->data_pages
[i
]);
2915 static inline int page_order(struct perf_buffer
*buffer
)
2923 * Back perf_mmap() with vmalloc memory.
2925 * Required for architectures that have d-cache aliasing issues.
2928 static inline int page_order(struct perf_buffer
*buffer
)
2930 return buffer
->page_order
;
2933 static struct page
*
2934 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
2936 if (pgoff
> (1UL << page_order(buffer
)))
2939 return vmalloc_to_page((void *)buffer
->user_page
+ pgoff
* PAGE_SIZE
);
2942 static void perf_mmap_unmark_page(void *addr
)
2944 struct page
*page
= vmalloc_to_page(addr
);
2946 page
->mapping
= NULL
;
2949 static void perf_buffer_free_work(struct work_struct
*work
)
2951 struct perf_buffer
*buffer
;
2955 buffer
= container_of(work
, struct perf_buffer
, work
);
2956 nr
= 1 << page_order(buffer
);
2958 base
= buffer
->user_page
;
2959 for (i
= 0; i
< nr
+ 1; i
++)
2960 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
2966 static void perf_buffer_free(struct perf_buffer
*buffer
)
2968 schedule_work(&buffer
->work
);
2971 static struct perf_buffer
*
2972 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
2974 struct perf_buffer
*buffer
;
2978 size
= sizeof(struct perf_buffer
);
2979 size
+= sizeof(void *);
2981 buffer
= kzalloc(size
, GFP_KERNEL
);
2985 INIT_WORK(&buffer
->work
, perf_buffer_free_work
);
2987 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
2991 buffer
->user_page
= all_buf
;
2992 buffer
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
2993 buffer
->page_order
= ilog2(nr_pages
);
2994 buffer
->nr_pages
= 1;
2996 perf_buffer_init(buffer
, watermark
, flags
);
3009 static unsigned long perf_data_size(struct perf_buffer
*buffer
)
3011 return buffer
->nr_pages
<< (PAGE_SHIFT
+ page_order(buffer
));
3014 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3016 struct perf_event
*event
= vma
->vm_file
->private_data
;
3017 struct perf_buffer
*buffer
;
3018 int ret
= VM_FAULT_SIGBUS
;
3020 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3021 if (vmf
->pgoff
== 0)
3027 buffer
= rcu_dereference(event
->buffer
);
3031 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3034 vmf
->page
= perf_mmap_to_page(buffer
, vmf
->pgoff
);
3038 get_page(vmf
->page
);
3039 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3040 vmf
->page
->index
= vmf
->pgoff
;
3049 static void perf_buffer_free_rcu(struct rcu_head
*rcu_head
)
3051 struct perf_buffer
*buffer
;
3053 buffer
= container_of(rcu_head
, struct perf_buffer
, rcu_head
);
3054 perf_buffer_free(buffer
);
3057 static struct perf_buffer
*perf_buffer_get(struct perf_event
*event
)
3059 struct perf_buffer
*buffer
;
3062 buffer
= rcu_dereference(event
->buffer
);
3064 if (!atomic_inc_not_zero(&buffer
->refcount
))
3072 static void perf_buffer_put(struct perf_buffer
*buffer
)
3074 if (!atomic_dec_and_test(&buffer
->refcount
))
3077 call_rcu(&buffer
->rcu_head
, perf_buffer_free_rcu
);
3080 static void perf_mmap_open(struct vm_area_struct
*vma
)
3082 struct perf_event
*event
= vma
->vm_file
->private_data
;
3084 atomic_inc(&event
->mmap_count
);
3087 static void perf_mmap_close(struct vm_area_struct
*vma
)
3089 struct perf_event
*event
= vma
->vm_file
->private_data
;
3091 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3092 unsigned long size
= perf_data_size(event
->buffer
);
3093 struct user_struct
*user
= event
->mmap_user
;
3094 struct perf_buffer
*buffer
= event
->buffer
;
3096 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3097 vma
->vm_mm
->locked_vm
-= event
->mmap_locked
;
3098 rcu_assign_pointer(event
->buffer
, NULL
);
3099 mutex_unlock(&event
->mmap_mutex
);
3101 perf_buffer_put(buffer
);
3106 static const struct vm_operations_struct perf_mmap_vmops
= {
3107 .open
= perf_mmap_open
,
3108 .close
= perf_mmap_close
,
3109 .fault
= perf_mmap_fault
,
3110 .page_mkwrite
= perf_mmap_fault
,
3113 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3115 struct perf_event
*event
= file
->private_data
;
3116 unsigned long user_locked
, user_lock_limit
;
3117 struct user_struct
*user
= current_user();
3118 unsigned long locked
, lock_limit
;
3119 struct perf_buffer
*buffer
;
3120 unsigned long vma_size
;
3121 unsigned long nr_pages
;
3122 long user_extra
, extra
;
3123 int ret
= 0, flags
= 0;
3126 * Don't allow mmap() of inherited per-task counters. This would
3127 * create a performance issue due to all children writing to the
3130 if (event
->cpu
== -1 && event
->attr
.inherit
)
3133 if (!(vma
->vm_flags
& VM_SHARED
))
3136 vma_size
= vma
->vm_end
- vma
->vm_start
;
3137 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3140 * If we have buffer pages ensure they're a power-of-two number, so we
3141 * can do bitmasks instead of modulo.
3143 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3146 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3149 if (vma
->vm_pgoff
!= 0)
3152 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3153 mutex_lock(&event
->mmap_mutex
);
3154 if (event
->buffer
) {
3155 if (event
->buffer
->nr_pages
== nr_pages
)
3156 atomic_inc(&event
->buffer
->refcount
);
3162 user_extra
= nr_pages
+ 1;
3163 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3166 * Increase the limit linearly with more CPUs:
3168 user_lock_limit
*= num_online_cpus();
3170 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3173 if (user_locked
> user_lock_limit
)
3174 extra
= user_locked
- user_lock_limit
;
3176 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3177 lock_limit
>>= PAGE_SHIFT
;
3178 locked
= vma
->vm_mm
->locked_vm
+ extra
;
3180 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3181 !capable(CAP_IPC_LOCK
)) {
3186 WARN_ON(event
->buffer
);
3188 if (vma
->vm_flags
& VM_WRITE
)
3189 flags
|= PERF_BUFFER_WRITABLE
;
3191 buffer
= perf_buffer_alloc(nr_pages
, event
->attr
.wakeup_watermark
,
3197 rcu_assign_pointer(event
->buffer
, buffer
);
3199 atomic_long_add(user_extra
, &user
->locked_vm
);
3200 event
->mmap_locked
= extra
;
3201 event
->mmap_user
= get_current_user();
3202 vma
->vm_mm
->locked_vm
+= event
->mmap_locked
;
3206 atomic_inc(&event
->mmap_count
);
3207 mutex_unlock(&event
->mmap_mutex
);
3209 vma
->vm_flags
|= VM_RESERVED
;
3210 vma
->vm_ops
= &perf_mmap_vmops
;
3215 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3217 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3218 struct perf_event
*event
= filp
->private_data
;
3221 mutex_lock(&inode
->i_mutex
);
3222 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3223 mutex_unlock(&inode
->i_mutex
);
3231 static const struct file_operations perf_fops
= {
3232 .llseek
= no_llseek
,
3233 .release
= perf_release
,
3236 .unlocked_ioctl
= perf_ioctl
,
3237 .compat_ioctl
= perf_ioctl
,
3239 .fasync
= perf_fasync
,
3245 * If there's data, ensure we set the poll() state and publish everything
3246 * to user-space before waking everybody up.
3249 void perf_event_wakeup(struct perf_event
*event
)
3251 wake_up_all(&event
->waitq
);
3253 if (event
->pending_kill
) {
3254 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3255 event
->pending_kill
= 0;
3259 static void perf_pending_event(struct irq_work
*entry
)
3261 struct perf_event
*event
= container_of(entry
,
3262 struct perf_event
, pending
);
3264 if (event
->pending_disable
) {
3265 event
->pending_disable
= 0;
3266 __perf_event_disable(event
);
3269 if (event
->pending_wakeup
) {
3270 event
->pending_wakeup
= 0;
3271 perf_event_wakeup(event
);
3276 * We assume there is only KVM supporting the callbacks.
3277 * Later on, we might change it to a list if there is
3278 * another virtualization implementation supporting the callbacks.
3280 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3282 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3284 perf_guest_cbs
= cbs
;
3287 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3289 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3291 perf_guest_cbs
= NULL
;
3294 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3299 static bool perf_output_space(struct perf_buffer
*buffer
, unsigned long tail
,
3300 unsigned long offset
, unsigned long head
)
3304 if (!buffer
->writable
)
3307 mask
= perf_data_size(buffer
) - 1;
3309 offset
= (offset
- tail
) & mask
;
3310 head
= (head
- tail
) & mask
;
3312 if ((int)(head
- offset
) < 0)
3318 static void perf_output_wakeup(struct perf_output_handle
*handle
)
3320 atomic_set(&handle
->buffer
->poll
, POLL_IN
);
3323 handle
->event
->pending_wakeup
= 1;
3324 irq_work_queue(&handle
->event
->pending
);
3326 perf_event_wakeup(handle
->event
);
3330 * We need to ensure a later event_id doesn't publish a head when a former
3331 * event isn't done writing. However since we need to deal with NMIs we
3332 * cannot fully serialize things.
3334 * We only publish the head (and generate a wakeup) when the outer-most
3337 static void perf_output_get_handle(struct perf_output_handle
*handle
)
3339 struct perf_buffer
*buffer
= handle
->buffer
;
3342 local_inc(&buffer
->nest
);
3343 handle
->wakeup
= local_read(&buffer
->wakeup
);
3346 static void perf_output_put_handle(struct perf_output_handle
*handle
)
3348 struct perf_buffer
*buffer
= handle
->buffer
;
3352 head
= local_read(&buffer
->head
);
3355 * IRQ/NMI can happen here, which means we can miss a head update.
3358 if (!local_dec_and_test(&buffer
->nest
))
3362 * Publish the known good head. Rely on the full barrier implied
3363 * by atomic_dec_and_test() order the buffer->head read and this
3366 buffer
->user_page
->data_head
= head
;
3369 * Now check if we missed an update, rely on the (compiler)
3370 * barrier in atomic_dec_and_test() to re-read buffer->head.
3372 if (unlikely(head
!= local_read(&buffer
->head
))) {
3373 local_inc(&buffer
->nest
);
3377 if (handle
->wakeup
!= local_read(&buffer
->wakeup
))
3378 perf_output_wakeup(handle
);
3384 __always_inline
void perf_output_copy(struct perf_output_handle
*handle
,
3385 const void *buf
, unsigned int len
)
3388 unsigned long size
= min_t(unsigned long, handle
->size
, len
);
3390 memcpy(handle
->addr
, buf
, size
);
3393 handle
->addr
+= size
;
3395 handle
->size
-= size
;
3396 if (!handle
->size
) {
3397 struct perf_buffer
*buffer
= handle
->buffer
;
3400 handle
->page
&= buffer
->nr_pages
- 1;
3401 handle
->addr
= buffer
->data_pages
[handle
->page
];
3402 handle
->size
= PAGE_SIZE
<< page_order(buffer
);
3407 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3408 struct perf_sample_data
*data
,
3409 struct perf_event
*event
)
3411 u64 sample_type
= event
->attr
.sample_type
;
3413 data
->type
= sample_type
;
3414 header
->size
+= event
->id_header_size
;
3416 if (sample_type
& PERF_SAMPLE_TID
) {
3417 /* namespace issues */
3418 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3419 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3422 if (sample_type
& PERF_SAMPLE_TIME
)
3423 data
->time
= perf_clock();
3425 if (sample_type
& PERF_SAMPLE_ID
)
3426 data
->id
= primary_event_id(event
);
3428 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3429 data
->stream_id
= event
->id
;
3431 if (sample_type
& PERF_SAMPLE_CPU
) {
3432 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3433 data
->cpu_entry
.reserved
= 0;
3437 static void perf_event_header__init_id(struct perf_event_header
*header
,
3438 struct perf_sample_data
*data
,
3439 struct perf_event
*event
)
3441 if (event
->attr
.sample_id_all
)
3442 __perf_event_header__init_id(header
, data
, event
);
3445 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
3446 struct perf_sample_data
*data
)
3448 u64 sample_type
= data
->type
;
3450 if (sample_type
& PERF_SAMPLE_TID
)
3451 perf_output_put(handle
, data
->tid_entry
);
3453 if (sample_type
& PERF_SAMPLE_TIME
)
3454 perf_output_put(handle
, data
->time
);
3456 if (sample_type
& PERF_SAMPLE_ID
)
3457 perf_output_put(handle
, data
->id
);
3459 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3460 perf_output_put(handle
, data
->stream_id
);
3462 if (sample_type
& PERF_SAMPLE_CPU
)
3463 perf_output_put(handle
, data
->cpu_entry
);
3466 static void perf_event__output_id_sample(struct perf_event
*event
,
3467 struct perf_output_handle
*handle
,
3468 struct perf_sample_data
*sample
)
3470 if (event
->attr
.sample_id_all
)
3471 __perf_event__output_id_sample(handle
, sample
);
3474 int perf_output_begin(struct perf_output_handle
*handle
,
3475 struct perf_event
*event
, unsigned int size
,
3476 int nmi
, int sample
)
3478 struct perf_buffer
*buffer
;
3479 unsigned long tail
, offset
, head
;
3481 struct perf_sample_data sample_data
;
3483 struct perf_event_header header
;
3490 * For inherited events we send all the output towards the parent.
3493 event
= event
->parent
;
3495 buffer
= rcu_dereference(event
->buffer
);
3499 handle
->buffer
= buffer
;
3500 handle
->event
= event
;
3502 handle
->sample
= sample
;
3504 if (!buffer
->nr_pages
)
3507 have_lost
= local_read(&buffer
->lost
);
3509 lost_event
.header
.size
= sizeof(lost_event
);
3510 perf_event_header__init_id(&lost_event
.header
, &sample_data
,
3512 size
+= lost_event
.header
.size
;
3515 perf_output_get_handle(handle
);
3519 * Userspace could choose to issue a mb() before updating the
3520 * tail pointer. So that all reads will be completed before the
3523 tail
= ACCESS_ONCE(buffer
->user_page
->data_tail
);
3525 offset
= head
= local_read(&buffer
->head
);
3527 if (unlikely(!perf_output_space(buffer
, tail
, offset
, head
)))
3529 } while (local_cmpxchg(&buffer
->head
, offset
, head
) != offset
);
3531 if (head
- local_read(&buffer
->wakeup
) > buffer
->watermark
)
3532 local_add(buffer
->watermark
, &buffer
->wakeup
);
3534 handle
->page
= offset
>> (PAGE_SHIFT
+ page_order(buffer
));
3535 handle
->page
&= buffer
->nr_pages
- 1;
3536 handle
->size
= offset
& ((PAGE_SIZE
<< page_order(buffer
)) - 1);
3537 handle
->addr
= buffer
->data_pages
[handle
->page
];
3538 handle
->addr
+= handle
->size
;
3539 handle
->size
= (PAGE_SIZE
<< page_order(buffer
)) - handle
->size
;
3542 lost_event
.header
.type
= PERF_RECORD_LOST
;
3543 lost_event
.header
.misc
= 0;
3544 lost_event
.id
= event
->id
;
3545 lost_event
.lost
= local_xchg(&buffer
->lost
, 0);
3547 perf_output_put(handle
, lost_event
);
3548 perf_event__output_id_sample(event
, handle
, &sample_data
);
3554 local_inc(&buffer
->lost
);
3555 perf_output_put_handle(handle
);
3562 void perf_output_end(struct perf_output_handle
*handle
)
3564 struct perf_event
*event
= handle
->event
;
3565 struct perf_buffer
*buffer
= handle
->buffer
;
3567 int wakeup_events
= event
->attr
.wakeup_events
;
3569 if (handle
->sample
&& wakeup_events
) {
3570 int events
= local_inc_return(&buffer
->events
);
3571 if (events
>= wakeup_events
) {
3572 local_sub(wakeup_events
, &buffer
->events
);
3573 local_inc(&buffer
->wakeup
);
3577 perf_output_put_handle(handle
);
3581 static void perf_output_read_one(struct perf_output_handle
*handle
,
3582 struct perf_event
*event
,
3583 u64 enabled
, u64 running
)
3585 u64 read_format
= event
->attr
.read_format
;
3589 values
[n
++] = perf_event_count(event
);
3590 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3591 values
[n
++] = enabled
+
3592 atomic64_read(&event
->child_total_time_enabled
);
3594 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3595 values
[n
++] = running
+
3596 atomic64_read(&event
->child_total_time_running
);
3598 if (read_format
& PERF_FORMAT_ID
)
3599 values
[n
++] = primary_event_id(event
);
3601 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3605 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3607 static void perf_output_read_group(struct perf_output_handle
*handle
,
3608 struct perf_event
*event
,
3609 u64 enabled
, u64 running
)
3611 struct perf_event
*leader
= event
->group_leader
, *sub
;
3612 u64 read_format
= event
->attr
.read_format
;
3616 values
[n
++] = 1 + leader
->nr_siblings
;
3618 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3619 values
[n
++] = enabled
;
3621 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3622 values
[n
++] = running
;
3624 if (leader
!= event
)
3625 leader
->pmu
->read(leader
);
3627 values
[n
++] = perf_event_count(leader
);
3628 if (read_format
& PERF_FORMAT_ID
)
3629 values
[n
++] = primary_event_id(leader
);
3631 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3633 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3637 sub
->pmu
->read(sub
);
3639 values
[n
++] = perf_event_count(sub
);
3640 if (read_format
& PERF_FORMAT_ID
)
3641 values
[n
++] = primary_event_id(sub
);
3643 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3647 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
3648 PERF_FORMAT_TOTAL_TIME_RUNNING)
3650 static void perf_output_read(struct perf_output_handle
*handle
,
3651 struct perf_event
*event
)
3653 u64 enabled
= 0, running
= 0, now
, ctx_time
;
3654 u64 read_format
= event
->attr
.read_format
;
3657 * compute total_time_enabled, total_time_running
3658 * based on snapshot values taken when the event
3659 * was last scheduled in.
3661 * we cannot simply called update_context_time()
3662 * because of locking issue as we are called in
3665 if (read_format
& PERF_FORMAT_TOTAL_TIMES
) {
3667 ctx_time
= event
->shadow_ctx_time
+ now
;
3668 enabled
= ctx_time
- event
->tstamp_enabled
;
3669 running
= ctx_time
- event
->tstamp_running
;
3672 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3673 perf_output_read_group(handle
, event
, enabled
, running
);
3675 perf_output_read_one(handle
, event
, enabled
, running
);
3678 void perf_output_sample(struct perf_output_handle
*handle
,
3679 struct perf_event_header
*header
,
3680 struct perf_sample_data
*data
,
3681 struct perf_event
*event
)
3683 u64 sample_type
= data
->type
;
3685 perf_output_put(handle
, *header
);
3687 if (sample_type
& PERF_SAMPLE_IP
)
3688 perf_output_put(handle
, data
->ip
);
3690 if (sample_type
& PERF_SAMPLE_TID
)
3691 perf_output_put(handle
, data
->tid_entry
);
3693 if (sample_type
& PERF_SAMPLE_TIME
)
3694 perf_output_put(handle
, data
->time
);
3696 if (sample_type
& PERF_SAMPLE_ADDR
)
3697 perf_output_put(handle
, data
->addr
);
3699 if (sample_type
& PERF_SAMPLE_ID
)
3700 perf_output_put(handle
, data
->id
);
3702 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3703 perf_output_put(handle
, data
->stream_id
);
3705 if (sample_type
& PERF_SAMPLE_CPU
)
3706 perf_output_put(handle
, data
->cpu_entry
);
3708 if (sample_type
& PERF_SAMPLE_PERIOD
)
3709 perf_output_put(handle
, data
->period
);
3711 if (sample_type
& PERF_SAMPLE_READ
)
3712 perf_output_read(handle
, event
);
3714 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3715 if (data
->callchain
) {
3718 if (data
->callchain
)
3719 size
+= data
->callchain
->nr
;
3721 size
*= sizeof(u64
);
3723 perf_output_copy(handle
, data
->callchain
, size
);
3726 perf_output_put(handle
, nr
);
3730 if (sample_type
& PERF_SAMPLE_RAW
) {
3732 perf_output_put(handle
, data
->raw
->size
);
3733 perf_output_copy(handle
, data
->raw
->data
,
3740 .size
= sizeof(u32
),
3743 perf_output_put(handle
, raw
);
3748 void perf_prepare_sample(struct perf_event_header
*header
,
3749 struct perf_sample_data
*data
,
3750 struct perf_event
*event
,
3751 struct pt_regs
*regs
)
3753 u64 sample_type
= event
->attr
.sample_type
;
3755 header
->type
= PERF_RECORD_SAMPLE
;
3756 header
->size
= sizeof(*header
) + event
->header_size
;
3759 header
->misc
|= perf_misc_flags(regs
);
3761 __perf_event_header__init_id(header
, data
, event
);
3763 if (sample_type
& PERF_SAMPLE_IP
)
3764 data
->ip
= perf_instruction_pointer(regs
);
3766 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3769 data
->callchain
= perf_callchain(regs
);
3771 if (data
->callchain
)
3772 size
+= data
->callchain
->nr
;
3774 header
->size
+= size
* sizeof(u64
);
3777 if (sample_type
& PERF_SAMPLE_RAW
) {
3778 int size
= sizeof(u32
);
3781 size
+= data
->raw
->size
;
3783 size
+= sizeof(u32
);
3785 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3786 header
->size
+= size
;
3790 static void perf_event_output(struct perf_event
*event
, int nmi
,
3791 struct perf_sample_data
*data
,
3792 struct pt_regs
*regs
)
3794 struct perf_output_handle handle
;
3795 struct perf_event_header header
;
3797 /* protect the callchain buffers */
3800 perf_prepare_sample(&header
, data
, event
, regs
);
3802 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
3805 perf_output_sample(&handle
, &header
, data
, event
);
3807 perf_output_end(&handle
);
3817 struct perf_read_event
{
3818 struct perf_event_header header
;
3825 perf_event_read_event(struct perf_event
*event
,
3826 struct task_struct
*task
)
3828 struct perf_output_handle handle
;
3829 struct perf_sample_data sample
;
3830 struct perf_read_event read_event
= {
3832 .type
= PERF_RECORD_READ
,
3834 .size
= sizeof(read_event
) + event
->read_size
,
3836 .pid
= perf_event_pid(event
, task
),
3837 .tid
= perf_event_tid(event
, task
),
3841 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
3842 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
3846 perf_output_put(&handle
, read_event
);
3847 perf_output_read(&handle
, event
);
3848 perf_event__output_id_sample(event
, &handle
, &sample
);
3850 perf_output_end(&handle
);
3854 * task tracking -- fork/exit
3856 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
3859 struct perf_task_event
{
3860 struct task_struct
*task
;
3861 struct perf_event_context
*task_ctx
;
3864 struct perf_event_header header
;
3874 static void perf_event_task_output(struct perf_event
*event
,
3875 struct perf_task_event
*task_event
)
3877 struct perf_output_handle handle
;
3878 struct perf_sample_data sample
;
3879 struct task_struct
*task
= task_event
->task
;
3880 int ret
, size
= task_event
->event_id
.header
.size
;
3882 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
3884 ret
= perf_output_begin(&handle
, event
,
3885 task_event
->event_id
.header
.size
, 0, 0);
3889 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
3890 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
3892 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
3893 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
3895 perf_output_put(&handle
, task_event
->event_id
);
3897 perf_event__output_id_sample(event
, &handle
, &sample
);
3899 perf_output_end(&handle
);
3901 task_event
->event_id
.header
.size
= size
;
3904 static int perf_event_task_match(struct perf_event
*event
)
3906 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3909 if (!event_filter_match(event
))
3912 if (event
->attr
.comm
|| event
->attr
.mmap
||
3913 event
->attr
.mmap_data
|| event
->attr
.task
)
3919 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
3920 struct perf_task_event
*task_event
)
3922 struct perf_event
*event
;
3924 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3925 if (perf_event_task_match(event
))
3926 perf_event_task_output(event
, task_event
);
3930 static void perf_event_task_event(struct perf_task_event
*task_event
)
3932 struct perf_cpu_context
*cpuctx
;
3933 struct perf_event_context
*ctx
;
3938 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
3939 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
3940 if (cpuctx
->active_pmu
!= pmu
)
3942 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
3944 ctx
= task_event
->task_ctx
;
3946 ctxn
= pmu
->task_ctx_nr
;
3949 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
3952 perf_event_task_ctx(ctx
, task_event
);
3954 put_cpu_ptr(pmu
->pmu_cpu_context
);
3959 static void perf_event_task(struct task_struct
*task
,
3960 struct perf_event_context
*task_ctx
,
3963 struct perf_task_event task_event
;
3965 if (!atomic_read(&nr_comm_events
) &&
3966 !atomic_read(&nr_mmap_events
) &&
3967 !atomic_read(&nr_task_events
))
3970 task_event
= (struct perf_task_event
){
3972 .task_ctx
= task_ctx
,
3975 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
3977 .size
= sizeof(task_event
.event_id
),
3983 .time
= perf_clock(),
3987 perf_event_task_event(&task_event
);
3990 void perf_event_fork(struct task_struct
*task
)
3992 perf_event_task(task
, NULL
, 1);
3999 struct perf_comm_event
{
4000 struct task_struct
*task
;
4005 struct perf_event_header header
;
4012 static void perf_event_comm_output(struct perf_event
*event
,
4013 struct perf_comm_event
*comm_event
)
4015 struct perf_output_handle handle
;
4016 struct perf_sample_data sample
;
4017 int size
= comm_event
->event_id
.header
.size
;
4020 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4021 ret
= perf_output_begin(&handle
, event
,
4022 comm_event
->event_id
.header
.size
, 0, 0);
4027 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4028 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4030 perf_output_put(&handle
, comm_event
->event_id
);
4031 perf_output_copy(&handle
, comm_event
->comm
,
4032 comm_event
->comm_size
);
4034 perf_event__output_id_sample(event
, &handle
, &sample
);
4036 perf_output_end(&handle
);
4038 comm_event
->event_id
.header
.size
= size
;
4041 static int perf_event_comm_match(struct perf_event
*event
)
4043 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4046 if (!event_filter_match(event
))
4049 if (event
->attr
.comm
)
4055 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4056 struct perf_comm_event
*comm_event
)
4058 struct perf_event
*event
;
4060 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4061 if (perf_event_comm_match(event
))
4062 perf_event_comm_output(event
, comm_event
);
4066 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4068 struct perf_cpu_context
*cpuctx
;
4069 struct perf_event_context
*ctx
;
4070 char comm
[TASK_COMM_LEN
];
4075 memset(comm
, 0, sizeof(comm
));
4076 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4077 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4079 comm_event
->comm
= comm
;
4080 comm_event
->comm_size
= size
;
4082 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4084 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4085 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4086 if (cpuctx
->active_pmu
!= pmu
)
4088 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4090 ctxn
= pmu
->task_ctx_nr
;
4094 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4096 perf_event_comm_ctx(ctx
, comm_event
);
4098 put_cpu_ptr(pmu
->pmu_cpu_context
);
4103 void perf_event_comm(struct task_struct
*task
)
4105 struct perf_comm_event comm_event
;
4106 struct perf_event_context
*ctx
;
4109 for_each_task_context_nr(ctxn
) {
4110 ctx
= task
->perf_event_ctxp
[ctxn
];
4114 perf_event_enable_on_exec(ctx
);
4117 if (!atomic_read(&nr_comm_events
))
4120 comm_event
= (struct perf_comm_event
){
4126 .type
= PERF_RECORD_COMM
,
4135 perf_event_comm_event(&comm_event
);
4142 struct perf_mmap_event
{
4143 struct vm_area_struct
*vma
;
4145 const char *file_name
;
4149 struct perf_event_header header
;
4159 static void perf_event_mmap_output(struct perf_event
*event
,
4160 struct perf_mmap_event
*mmap_event
)
4162 struct perf_output_handle handle
;
4163 struct perf_sample_data sample
;
4164 int size
= mmap_event
->event_id
.header
.size
;
4167 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4168 ret
= perf_output_begin(&handle
, event
,
4169 mmap_event
->event_id
.header
.size
, 0, 0);
4173 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4174 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4176 perf_output_put(&handle
, mmap_event
->event_id
);
4177 perf_output_copy(&handle
, mmap_event
->file_name
,
4178 mmap_event
->file_size
);
4180 perf_event__output_id_sample(event
, &handle
, &sample
);
4182 perf_output_end(&handle
);
4184 mmap_event
->event_id
.header
.size
= size
;
4187 static int perf_event_mmap_match(struct perf_event
*event
,
4188 struct perf_mmap_event
*mmap_event
,
4191 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4194 if (!event_filter_match(event
))
4197 if ((!executable
&& event
->attr
.mmap_data
) ||
4198 (executable
&& event
->attr
.mmap
))
4204 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4205 struct perf_mmap_event
*mmap_event
,
4208 struct perf_event
*event
;
4210 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4211 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4212 perf_event_mmap_output(event
, mmap_event
);
4216 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4218 struct perf_cpu_context
*cpuctx
;
4219 struct perf_event_context
*ctx
;
4220 struct vm_area_struct
*vma
= mmap_event
->vma
;
4221 struct file
*file
= vma
->vm_file
;
4229 memset(tmp
, 0, sizeof(tmp
));
4233 * d_path works from the end of the buffer backwards, so we
4234 * need to add enough zero bytes after the string to handle
4235 * the 64bit alignment we do later.
4237 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4239 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4242 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4244 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4248 if (arch_vma_name(mmap_event
->vma
)) {
4249 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4255 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4257 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4258 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4259 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4261 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4262 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4263 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4267 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4272 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4274 mmap_event
->file_name
= name
;
4275 mmap_event
->file_size
= size
;
4277 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4280 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4281 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4282 if (cpuctx
->active_pmu
!= pmu
)
4284 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4285 vma
->vm_flags
& VM_EXEC
);
4287 ctxn
= pmu
->task_ctx_nr
;
4291 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4293 perf_event_mmap_ctx(ctx
, mmap_event
,
4294 vma
->vm_flags
& VM_EXEC
);
4297 put_cpu_ptr(pmu
->pmu_cpu_context
);
4304 void perf_event_mmap(struct vm_area_struct
*vma
)
4306 struct perf_mmap_event mmap_event
;
4308 if (!atomic_read(&nr_mmap_events
))
4311 mmap_event
= (struct perf_mmap_event
){
4317 .type
= PERF_RECORD_MMAP
,
4318 .misc
= PERF_RECORD_MISC_USER
,
4323 .start
= vma
->vm_start
,
4324 .len
= vma
->vm_end
- vma
->vm_start
,
4325 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4329 perf_event_mmap_event(&mmap_event
);
4333 * IRQ throttle logging
4336 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4338 struct perf_output_handle handle
;
4339 struct perf_sample_data sample
;
4343 struct perf_event_header header
;
4347 } throttle_event
= {
4349 .type
= PERF_RECORD_THROTTLE
,
4351 .size
= sizeof(throttle_event
),
4353 .time
= perf_clock(),
4354 .id
= primary_event_id(event
),
4355 .stream_id
= event
->id
,
4359 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4361 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4363 ret
= perf_output_begin(&handle
, event
,
4364 throttle_event
.header
.size
, 1, 0);
4368 perf_output_put(&handle
, throttle_event
);
4369 perf_event__output_id_sample(event
, &handle
, &sample
);
4370 perf_output_end(&handle
);
4374 * Generic event overflow handling, sampling.
4377 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
4378 int throttle
, struct perf_sample_data
*data
,
4379 struct pt_regs
*regs
)
4381 int events
= atomic_read(&event
->event_limit
);
4382 struct hw_perf_event
*hwc
= &event
->hw
;
4386 * Non-sampling counters might still use the PMI to fold short
4387 * hardware counters, ignore those.
4389 if (unlikely(!is_sampling_event(event
)))
4395 if (hwc
->interrupts
!= MAX_INTERRUPTS
) {
4397 if (HZ
* hwc
->interrupts
>
4398 (u64
)sysctl_perf_event_sample_rate
) {
4399 hwc
->interrupts
= MAX_INTERRUPTS
;
4400 perf_log_throttle(event
, 0);
4405 * Keep re-disabling events even though on the previous
4406 * pass we disabled it - just in case we raced with a
4407 * sched-in and the event got enabled again:
4413 if (event
->attr
.freq
) {
4414 u64 now
= perf_clock();
4415 s64 delta
= now
- hwc
->freq_time_stamp
;
4417 hwc
->freq_time_stamp
= now
;
4419 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4420 perf_adjust_period(event
, delta
, hwc
->last_period
);
4424 * XXX event_limit might not quite work as expected on inherited
4428 event
->pending_kill
= POLL_IN
;
4429 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4431 event
->pending_kill
= POLL_HUP
;
4433 event
->pending_disable
= 1;
4434 irq_work_queue(&event
->pending
);
4436 perf_event_disable(event
);
4439 if (event
->overflow_handler
)
4440 event
->overflow_handler(event
, nmi
, data
, regs
);
4442 perf_event_output(event
, nmi
, data
, regs
);
4447 int perf_event_overflow(struct perf_event
*event
, int nmi
,
4448 struct perf_sample_data
*data
,
4449 struct pt_regs
*regs
)
4451 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
4455 * Generic software event infrastructure
4458 struct swevent_htable
{
4459 struct swevent_hlist
*swevent_hlist
;
4460 struct mutex hlist_mutex
;
4463 /* Recursion avoidance in each contexts */
4464 int recursion
[PERF_NR_CONTEXTS
];
4467 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
4470 * We directly increment event->count and keep a second value in
4471 * event->hw.period_left to count intervals. This period event
4472 * is kept in the range [-sample_period, 0] so that we can use the
4476 static u64
perf_swevent_set_period(struct perf_event
*event
)
4478 struct hw_perf_event
*hwc
= &event
->hw
;
4479 u64 period
= hwc
->last_period
;
4483 hwc
->last_period
= hwc
->sample_period
;
4486 old
= val
= local64_read(&hwc
->period_left
);
4490 nr
= div64_u64(period
+ val
, period
);
4491 offset
= nr
* period
;
4493 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
4499 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
4500 int nmi
, struct perf_sample_data
*data
,
4501 struct pt_regs
*regs
)
4503 struct hw_perf_event
*hwc
= &event
->hw
;
4506 data
->period
= event
->hw
.last_period
;
4508 overflow
= perf_swevent_set_period(event
);
4510 if (hwc
->interrupts
== MAX_INTERRUPTS
)
4513 for (; overflow
; overflow
--) {
4514 if (__perf_event_overflow(event
, nmi
, throttle
,
4517 * We inhibit the overflow from happening when
4518 * hwc->interrupts == MAX_INTERRUPTS.
4526 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
4527 int nmi
, struct perf_sample_data
*data
,
4528 struct pt_regs
*regs
)
4530 struct hw_perf_event
*hwc
= &event
->hw
;
4532 local64_add(nr
, &event
->count
);
4537 if (!is_sampling_event(event
))
4540 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
4541 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
4543 if (local64_add_negative(nr
, &hwc
->period_left
))
4546 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
4549 static int perf_exclude_event(struct perf_event
*event
,
4550 struct pt_regs
*regs
)
4552 if (event
->hw
.state
& PERF_HES_STOPPED
)
4556 if (event
->attr
.exclude_user
&& user_mode(regs
))
4559 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4566 static int perf_swevent_match(struct perf_event
*event
,
4567 enum perf_type_id type
,
4569 struct perf_sample_data
*data
,
4570 struct pt_regs
*regs
)
4572 if (event
->attr
.type
!= type
)
4575 if (event
->attr
.config
!= event_id
)
4578 if (perf_exclude_event(event
, regs
))
4584 static inline u64
swevent_hash(u64 type
, u32 event_id
)
4586 u64 val
= event_id
| (type
<< 32);
4588 return hash_64(val
, SWEVENT_HLIST_BITS
);
4591 static inline struct hlist_head
*
4592 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
4594 u64 hash
= swevent_hash(type
, event_id
);
4596 return &hlist
->heads
[hash
];
4599 /* For the read side: events when they trigger */
4600 static inline struct hlist_head
*
4601 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
4603 struct swevent_hlist
*hlist
;
4605 hlist
= rcu_dereference(swhash
->swevent_hlist
);
4609 return __find_swevent_head(hlist
, type
, event_id
);
4612 /* For the event head insertion and removal in the hlist */
4613 static inline struct hlist_head
*
4614 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
4616 struct swevent_hlist
*hlist
;
4617 u32 event_id
= event
->attr
.config
;
4618 u64 type
= event
->attr
.type
;
4621 * Event scheduling is always serialized against hlist allocation
4622 * and release. Which makes the protected version suitable here.
4623 * The context lock guarantees that.
4625 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
4626 lockdep_is_held(&event
->ctx
->lock
));
4630 return __find_swevent_head(hlist
, type
, event_id
);
4633 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4635 struct perf_sample_data
*data
,
4636 struct pt_regs
*regs
)
4638 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4639 struct perf_event
*event
;
4640 struct hlist_node
*node
;
4641 struct hlist_head
*head
;
4644 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
4648 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4649 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4650 perf_swevent_event(event
, nr
, nmi
, data
, regs
);
4656 int perf_swevent_get_recursion_context(void)
4658 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4660 return get_recursion_context(swhash
->recursion
);
4662 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4664 inline void perf_swevent_put_recursion_context(int rctx
)
4666 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4668 put_recursion_context(swhash
->recursion
, rctx
);
4671 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
4672 struct pt_regs
*regs
, u64 addr
)
4674 struct perf_sample_data data
;
4677 preempt_disable_notrace();
4678 rctx
= perf_swevent_get_recursion_context();
4682 perf_sample_data_init(&data
, addr
);
4684 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
4686 perf_swevent_put_recursion_context(rctx
);
4687 preempt_enable_notrace();
4690 static void perf_swevent_read(struct perf_event
*event
)
4694 static int perf_swevent_add(struct perf_event
*event
, int flags
)
4696 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4697 struct hw_perf_event
*hwc
= &event
->hw
;
4698 struct hlist_head
*head
;
4700 if (is_sampling_event(event
)) {
4701 hwc
->last_period
= hwc
->sample_period
;
4702 perf_swevent_set_period(event
);
4705 hwc
->state
= !(flags
& PERF_EF_START
);
4707 head
= find_swevent_head(swhash
, event
);
4708 if (WARN_ON_ONCE(!head
))
4711 hlist_add_head_rcu(&event
->hlist_entry
, head
);
4716 static void perf_swevent_del(struct perf_event
*event
, int flags
)
4718 hlist_del_rcu(&event
->hlist_entry
);
4721 static void perf_swevent_start(struct perf_event
*event
, int flags
)
4723 event
->hw
.state
= 0;
4726 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
4728 event
->hw
.state
= PERF_HES_STOPPED
;
4731 /* Deref the hlist from the update side */
4732 static inline struct swevent_hlist
*
4733 swevent_hlist_deref(struct swevent_htable
*swhash
)
4735 return rcu_dereference_protected(swhash
->swevent_hlist
,
4736 lockdep_is_held(&swhash
->hlist_mutex
));
4739 static void swevent_hlist_release_rcu(struct rcu_head
*rcu_head
)
4741 struct swevent_hlist
*hlist
;
4743 hlist
= container_of(rcu_head
, struct swevent_hlist
, rcu_head
);
4747 static void swevent_hlist_release(struct swevent_htable
*swhash
)
4749 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
4754 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
4755 call_rcu(&hlist
->rcu_head
, swevent_hlist_release_rcu
);
4758 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
4760 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4762 mutex_lock(&swhash
->hlist_mutex
);
4764 if (!--swhash
->hlist_refcount
)
4765 swevent_hlist_release(swhash
);
4767 mutex_unlock(&swhash
->hlist_mutex
);
4770 static void swevent_hlist_put(struct perf_event
*event
)
4774 if (event
->cpu
!= -1) {
4775 swevent_hlist_put_cpu(event
, event
->cpu
);
4779 for_each_possible_cpu(cpu
)
4780 swevent_hlist_put_cpu(event
, cpu
);
4783 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
4785 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4788 mutex_lock(&swhash
->hlist_mutex
);
4790 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
4791 struct swevent_hlist
*hlist
;
4793 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
4798 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
4800 swhash
->hlist_refcount
++;
4802 mutex_unlock(&swhash
->hlist_mutex
);
4807 static int swevent_hlist_get(struct perf_event
*event
)
4810 int cpu
, failed_cpu
;
4812 if (event
->cpu
!= -1)
4813 return swevent_hlist_get_cpu(event
, event
->cpu
);
4816 for_each_possible_cpu(cpu
) {
4817 err
= swevent_hlist_get_cpu(event
, cpu
);
4827 for_each_possible_cpu(cpu
) {
4828 if (cpu
== failed_cpu
)
4830 swevent_hlist_put_cpu(event
, cpu
);
4837 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4839 static void sw_perf_event_destroy(struct perf_event
*event
)
4841 u64 event_id
= event
->attr
.config
;
4843 WARN_ON(event
->parent
);
4845 jump_label_dec(&perf_swevent_enabled
[event_id
]);
4846 swevent_hlist_put(event
);
4849 static int perf_swevent_init(struct perf_event
*event
)
4851 int event_id
= event
->attr
.config
;
4853 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
4857 case PERF_COUNT_SW_CPU_CLOCK
:
4858 case PERF_COUNT_SW_TASK_CLOCK
:
4865 if (event_id
>= PERF_COUNT_SW_MAX
)
4868 if (!event
->parent
) {
4871 err
= swevent_hlist_get(event
);
4875 jump_label_inc(&perf_swevent_enabled
[event_id
]);
4876 event
->destroy
= sw_perf_event_destroy
;
4882 static struct pmu perf_swevent
= {
4883 .task_ctx_nr
= perf_sw_context
,
4885 .event_init
= perf_swevent_init
,
4886 .add
= perf_swevent_add
,
4887 .del
= perf_swevent_del
,
4888 .start
= perf_swevent_start
,
4889 .stop
= perf_swevent_stop
,
4890 .read
= perf_swevent_read
,
4893 #ifdef CONFIG_EVENT_TRACING
4895 static int perf_tp_filter_match(struct perf_event
*event
,
4896 struct perf_sample_data
*data
)
4898 void *record
= data
->raw
->data
;
4900 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
4905 static int perf_tp_event_match(struct perf_event
*event
,
4906 struct perf_sample_data
*data
,
4907 struct pt_regs
*regs
)
4910 * All tracepoints are from kernel-space.
4912 if (event
->attr
.exclude_kernel
)
4915 if (!perf_tp_filter_match(event
, data
))
4921 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
4922 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
4924 struct perf_sample_data data
;
4925 struct perf_event
*event
;
4926 struct hlist_node
*node
;
4928 struct perf_raw_record raw
= {
4933 perf_sample_data_init(&data
, addr
);
4936 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4937 if (perf_tp_event_match(event
, &data
, regs
))
4938 perf_swevent_event(event
, count
, 1, &data
, regs
);
4941 perf_swevent_put_recursion_context(rctx
);
4943 EXPORT_SYMBOL_GPL(perf_tp_event
);
4945 static void tp_perf_event_destroy(struct perf_event
*event
)
4947 perf_trace_destroy(event
);
4950 static int perf_tp_event_init(struct perf_event
*event
)
4954 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4957 err
= perf_trace_init(event
);
4961 event
->destroy
= tp_perf_event_destroy
;
4966 static struct pmu perf_tracepoint
= {
4967 .task_ctx_nr
= perf_sw_context
,
4969 .event_init
= perf_tp_event_init
,
4970 .add
= perf_trace_add
,
4971 .del
= perf_trace_del
,
4972 .start
= perf_swevent_start
,
4973 .stop
= perf_swevent_stop
,
4974 .read
= perf_swevent_read
,
4977 static inline void perf_tp_register(void)
4979 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
4982 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
4987 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4990 filter_str
= strndup_user(arg
, PAGE_SIZE
);
4991 if (IS_ERR(filter_str
))
4992 return PTR_ERR(filter_str
);
4994 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5000 static void perf_event_free_filter(struct perf_event
*event
)
5002 ftrace_profile_free_filter(event
);
5007 static inline void perf_tp_register(void)
5011 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5016 static void perf_event_free_filter(struct perf_event
*event
)
5020 #endif /* CONFIG_EVENT_TRACING */
5022 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5023 void perf_bp_event(struct perf_event
*bp
, void *data
)
5025 struct perf_sample_data sample
;
5026 struct pt_regs
*regs
= data
;
5028 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
5030 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5031 perf_swevent_event(bp
, 1, 1, &sample
, regs
);
5036 * hrtimer based swevent callback
5039 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5041 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5042 struct perf_sample_data data
;
5043 struct pt_regs
*regs
;
5044 struct perf_event
*event
;
5047 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5048 event
->pmu
->read(event
);
5050 perf_sample_data_init(&data
, 0);
5051 data
.period
= event
->hw
.last_period
;
5052 regs
= get_irq_regs();
5054 if (regs
&& !perf_exclude_event(event
, regs
)) {
5055 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
5056 if (perf_event_overflow(event
, 0, &data
, regs
))
5057 ret
= HRTIMER_NORESTART
;
5060 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5061 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5066 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5068 struct hw_perf_event
*hwc
= &event
->hw
;
5071 if (!is_sampling_event(event
))
5074 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5075 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5077 period
= local64_read(&hwc
->period_left
);
5082 local64_set(&hwc
->period_left
, 0);
5084 period
= max_t(u64
, 10000, hwc
->sample_period
);
5086 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5087 ns_to_ktime(period
), 0,
5088 HRTIMER_MODE_REL_PINNED
, 0);
5091 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5093 struct hw_perf_event
*hwc
= &event
->hw
;
5095 if (is_sampling_event(event
)) {
5096 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5097 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5099 hrtimer_cancel(&hwc
->hrtimer
);
5104 * Software event: cpu wall time clock
5107 static void cpu_clock_event_update(struct perf_event
*event
)
5112 now
= local_clock();
5113 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5114 local64_add(now
- prev
, &event
->count
);
5117 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5119 local64_set(&event
->hw
.prev_count
, local_clock());
5120 perf_swevent_start_hrtimer(event
);
5123 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5125 perf_swevent_cancel_hrtimer(event
);
5126 cpu_clock_event_update(event
);
5129 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5131 if (flags
& PERF_EF_START
)
5132 cpu_clock_event_start(event
, flags
);
5137 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5139 cpu_clock_event_stop(event
, flags
);
5142 static void cpu_clock_event_read(struct perf_event
*event
)
5144 cpu_clock_event_update(event
);
5147 static int cpu_clock_event_init(struct perf_event
*event
)
5149 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5152 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5158 static struct pmu perf_cpu_clock
= {
5159 .task_ctx_nr
= perf_sw_context
,
5161 .event_init
= cpu_clock_event_init
,
5162 .add
= cpu_clock_event_add
,
5163 .del
= cpu_clock_event_del
,
5164 .start
= cpu_clock_event_start
,
5165 .stop
= cpu_clock_event_stop
,
5166 .read
= cpu_clock_event_read
,
5170 * Software event: task time clock
5173 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5178 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5180 local64_add(delta
, &event
->count
);
5183 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5185 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5186 perf_swevent_start_hrtimer(event
);
5189 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5191 perf_swevent_cancel_hrtimer(event
);
5192 task_clock_event_update(event
, event
->ctx
->time
);
5195 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5197 if (flags
& PERF_EF_START
)
5198 task_clock_event_start(event
, flags
);
5203 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5205 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5208 static void task_clock_event_read(struct perf_event
*event
)
5213 update_context_time(event
->ctx
);
5214 time
= event
->ctx
->time
;
5216 u64 now
= perf_clock();
5217 u64 delta
= now
- event
->ctx
->timestamp
;
5218 time
= event
->ctx
->time
+ delta
;
5221 task_clock_event_update(event
, time
);
5224 static int task_clock_event_init(struct perf_event
*event
)
5226 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5229 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5235 static struct pmu perf_task_clock
= {
5236 .task_ctx_nr
= perf_sw_context
,
5238 .event_init
= task_clock_event_init
,
5239 .add
= task_clock_event_add
,
5240 .del
= task_clock_event_del
,
5241 .start
= task_clock_event_start
,
5242 .stop
= task_clock_event_stop
,
5243 .read
= task_clock_event_read
,
5246 static void perf_pmu_nop_void(struct pmu
*pmu
)
5250 static int perf_pmu_nop_int(struct pmu
*pmu
)
5255 static void perf_pmu_start_txn(struct pmu
*pmu
)
5257 perf_pmu_disable(pmu
);
5260 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5262 perf_pmu_enable(pmu
);
5266 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5268 perf_pmu_enable(pmu
);
5272 * Ensures all contexts with the same task_ctx_nr have the same
5273 * pmu_cpu_context too.
5275 static void *find_pmu_context(int ctxn
)
5282 list_for_each_entry(pmu
, &pmus
, entry
) {
5283 if (pmu
->task_ctx_nr
== ctxn
)
5284 return pmu
->pmu_cpu_context
;
5290 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5294 for_each_possible_cpu(cpu
) {
5295 struct perf_cpu_context
*cpuctx
;
5297 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5299 if (cpuctx
->active_pmu
== old_pmu
)
5300 cpuctx
->active_pmu
= pmu
;
5304 static void free_pmu_context(struct pmu
*pmu
)
5308 mutex_lock(&pmus_lock
);
5310 * Like a real lame refcount.
5312 list_for_each_entry(i
, &pmus
, entry
) {
5313 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5314 update_pmu_context(i
, pmu
);
5319 free_percpu(pmu
->pmu_cpu_context
);
5321 mutex_unlock(&pmus_lock
);
5323 static struct idr pmu_idr
;
5326 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5328 struct pmu
*pmu
= dev_get_drvdata(dev
);
5330 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5333 static struct device_attribute pmu_dev_attrs
[] = {
5338 static int pmu_bus_running
;
5339 static struct bus_type pmu_bus
= {
5340 .name
= "event_source",
5341 .dev_attrs
= pmu_dev_attrs
,
5344 static void pmu_dev_release(struct device
*dev
)
5349 static int pmu_dev_alloc(struct pmu
*pmu
)
5353 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5357 device_initialize(pmu
->dev
);
5358 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5362 dev_set_drvdata(pmu
->dev
, pmu
);
5363 pmu
->dev
->bus
= &pmu_bus
;
5364 pmu
->dev
->release
= pmu_dev_release
;
5365 ret
= device_add(pmu
->dev
);
5373 put_device(pmu
->dev
);
5377 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5381 mutex_lock(&pmus_lock
);
5383 pmu
->pmu_disable_count
= alloc_percpu(int);
5384 if (!pmu
->pmu_disable_count
)
5393 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
5397 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
5405 if (pmu_bus_running
) {
5406 ret
= pmu_dev_alloc(pmu
);
5412 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
5413 if (pmu
->pmu_cpu_context
)
5414 goto got_cpu_context
;
5416 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
5417 if (!pmu
->pmu_cpu_context
)
5420 for_each_possible_cpu(cpu
) {
5421 struct perf_cpu_context
*cpuctx
;
5423 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5424 __perf_event_init_context(&cpuctx
->ctx
);
5425 cpuctx
->ctx
.type
= cpu_context
;
5426 cpuctx
->ctx
.pmu
= pmu
;
5427 cpuctx
->jiffies_interval
= 1;
5428 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
5429 cpuctx
->active_pmu
= pmu
;
5433 if (!pmu
->start_txn
) {
5434 if (pmu
->pmu_enable
) {
5436 * If we have pmu_enable/pmu_disable calls, install
5437 * transaction stubs that use that to try and batch
5438 * hardware accesses.
5440 pmu
->start_txn
= perf_pmu_start_txn
;
5441 pmu
->commit_txn
= perf_pmu_commit_txn
;
5442 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
5444 pmu
->start_txn
= perf_pmu_nop_void
;
5445 pmu
->commit_txn
= perf_pmu_nop_int
;
5446 pmu
->cancel_txn
= perf_pmu_nop_void
;
5450 if (!pmu
->pmu_enable
) {
5451 pmu
->pmu_enable
= perf_pmu_nop_void
;
5452 pmu
->pmu_disable
= perf_pmu_nop_void
;
5455 list_add_rcu(&pmu
->entry
, &pmus
);
5458 mutex_unlock(&pmus_lock
);
5463 device_del(pmu
->dev
);
5464 put_device(pmu
->dev
);
5467 if (pmu
->type
>= PERF_TYPE_MAX
)
5468 idr_remove(&pmu_idr
, pmu
->type
);
5471 free_percpu(pmu
->pmu_disable_count
);
5475 void perf_pmu_unregister(struct pmu
*pmu
)
5477 mutex_lock(&pmus_lock
);
5478 list_del_rcu(&pmu
->entry
);
5479 mutex_unlock(&pmus_lock
);
5482 * We dereference the pmu list under both SRCU and regular RCU, so
5483 * synchronize against both of those.
5485 synchronize_srcu(&pmus_srcu
);
5488 free_percpu(pmu
->pmu_disable_count
);
5489 if (pmu
->type
>= PERF_TYPE_MAX
)
5490 idr_remove(&pmu_idr
, pmu
->type
);
5491 device_del(pmu
->dev
);
5492 put_device(pmu
->dev
);
5493 free_pmu_context(pmu
);
5496 struct pmu
*perf_init_event(struct perf_event
*event
)
5498 struct pmu
*pmu
= NULL
;
5501 idx
= srcu_read_lock(&pmus_srcu
);
5504 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
5509 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5510 int ret
= pmu
->event_init(event
);
5514 if (ret
!= -ENOENT
) {
5519 pmu
= ERR_PTR(-ENOENT
);
5521 srcu_read_unlock(&pmus_srcu
, idx
);
5527 * Allocate and initialize a event structure
5529 static struct perf_event
*
5530 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
5531 struct task_struct
*task
,
5532 struct perf_event
*group_leader
,
5533 struct perf_event
*parent_event
,
5534 perf_overflow_handler_t overflow_handler
)
5537 struct perf_event
*event
;
5538 struct hw_perf_event
*hwc
;
5541 if ((unsigned)cpu
>= nr_cpu_ids
) {
5542 if (!task
|| cpu
!= -1)
5543 return ERR_PTR(-EINVAL
);
5546 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
5548 return ERR_PTR(-ENOMEM
);
5551 * Single events are their own group leaders, with an
5552 * empty sibling list:
5555 group_leader
= event
;
5557 mutex_init(&event
->child_mutex
);
5558 INIT_LIST_HEAD(&event
->child_list
);
5560 INIT_LIST_HEAD(&event
->group_entry
);
5561 INIT_LIST_HEAD(&event
->event_entry
);
5562 INIT_LIST_HEAD(&event
->sibling_list
);
5563 init_waitqueue_head(&event
->waitq
);
5564 init_irq_work(&event
->pending
, perf_pending_event
);
5566 mutex_init(&event
->mmap_mutex
);
5569 event
->attr
= *attr
;
5570 event
->group_leader
= group_leader
;
5574 event
->parent
= parent_event
;
5576 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
5577 event
->id
= atomic64_inc_return(&perf_event_id
);
5579 event
->state
= PERF_EVENT_STATE_INACTIVE
;
5582 event
->attach_state
= PERF_ATTACH_TASK
;
5583 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5585 * hw_breakpoint is a bit difficult here..
5587 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
5588 event
->hw
.bp_target
= task
;
5592 if (!overflow_handler
&& parent_event
)
5593 overflow_handler
= parent_event
->overflow_handler
;
5595 event
->overflow_handler
= overflow_handler
;
5598 event
->state
= PERF_EVENT_STATE_OFF
;
5603 hwc
->sample_period
= attr
->sample_period
;
5604 if (attr
->freq
&& attr
->sample_freq
)
5605 hwc
->sample_period
= 1;
5606 hwc
->last_period
= hwc
->sample_period
;
5608 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5611 * we currently do not support PERF_FORMAT_GROUP on inherited events
5613 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
5616 pmu
= perf_init_event(event
);
5622 else if (IS_ERR(pmu
))
5627 put_pid_ns(event
->ns
);
5629 return ERR_PTR(err
);
5634 if (!event
->parent
) {
5635 if (event
->attach_state
& PERF_ATTACH_TASK
)
5636 jump_label_inc(&perf_task_events
);
5637 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
5638 atomic_inc(&nr_mmap_events
);
5639 if (event
->attr
.comm
)
5640 atomic_inc(&nr_comm_events
);
5641 if (event
->attr
.task
)
5642 atomic_inc(&nr_task_events
);
5643 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5644 err
= get_callchain_buffers();
5647 return ERR_PTR(err
);
5655 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5656 struct perf_event_attr
*attr
)
5661 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
5665 * zero the full structure, so that a short copy will be nice.
5667 memset(attr
, 0, sizeof(*attr
));
5669 ret
= get_user(size
, &uattr
->size
);
5673 if (size
> PAGE_SIZE
) /* silly large */
5676 if (!size
) /* abi compat */
5677 size
= PERF_ATTR_SIZE_VER0
;
5679 if (size
< PERF_ATTR_SIZE_VER0
)
5683 * If we're handed a bigger struct than we know of,
5684 * ensure all the unknown bits are 0 - i.e. new
5685 * user-space does not rely on any kernel feature
5686 * extensions we dont know about yet.
5688 if (size
> sizeof(*attr
)) {
5689 unsigned char __user
*addr
;
5690 unsigned char __user
*end
;
5693 addr
= (void __user
*)uattr
+ sizeof(*attr
);
5694 end
= (void __user
*)uattr
+ size
;
5696 for (; addr
< end
; addr
++) {
5697 ret
= get_user(val
, addr
);
5703 size
= sizeof(*attr
);
5706 ret
= copy_from_user(attr
, uattr
, size
);
5711 * If the type exists, the corresponding creation will verify
5714 if (attr
->type
>= PERF_TYPE_MAX
)
5717 if (attr
->__reserved_1
)
5720 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
5723 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
5730 put_user(sizeof(*attr
), &uattr
->size
);
5736 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
5738 struct perf_buffer
*buffer
= NULL
, *old_buffer
= NULL
;
5744 /* don't allow circular references */
5745 if (event
== output_event
)
5749 * Don't allow cross-cpu buffers
5751 if (output_event
->cpu
!= event
->cpu
)
5755 * If its not a per-cpu buffer, it must be the same task.
5757 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
5761 mutex_lock(&event
->mmap_mutex
);
5762 /* Can't redirect output if we've got an active mmap() */
5763 if (atomic_read(&event
->mmap_count
))
5767 /* get the buffer we want to redirect to */
5768 buffer
= perf_buffer_get(output_event
);
5773 old_buffer
= event
->buffer
;
5774 rcu_assign_pointer(event
->buffer
, buffer
);
5777 mutex_unlock(&event
->mmap_mutex
);
5780 perf_buffer_put(old_buffer
);
5786 * sys_perf_event_open - open a performance event, associate it to a task/cpu
5788 * @attr_uptr: event_id type attributes for monitoring/sampling
5791 * @group_fd: group leader event fd
5793 SYSCALL_DEFINE5(perf_event_open
,
5794 struct perf_event_attr __user
*, attr_uptr
,
5795 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
5797 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
5798 struct perf_event
*event
, *sibling
;
5799 struct perf_event_attr attr
;
5800 struct perf_event_context
*ctx
;
5801 struct file
*event_file
= NULL
;
5802 struct file
*group_file
= NULL
;
5803 struct task_struct
*task
= NULL
;
5807 int fput_needed
= 0;
5810 /* for future expandability... */
5811 if (flags
& ~(PERF_FLAG_FD_NO_GROUP
| PERF_FLAG_FD_OUTPUT
))
5814 err
= perf_copy_attr(attr_uptr
, &attr
);
5818 if (!attr
.exclude_kernel
) {
5819 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
5824 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
5828 event_fd
= get_unused_fd_flags(O_RDWR
);
5832 if (group_fd
!= -1) {
5833 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
5834 if (IS_ERR(group_leader
)) {
5835 err
= PTR_ERR(group_leader
);
5838 group_file
= group_leader
->filp
;
5839 if (flags
& PERF_FLAG_FD_OUTPUT
)
5840 output_event
= group_leader
;
5841 if (flags
& PERF_FLAG_FD_NO_GROUP
)
5842 group_leader
= NULL
;
5846 task
= find_lively_task_by_vpid(pid
);
5848 err
= PTR_ERR(task
);
5853 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
, NULL
);
5854 if (IS_ERR(event
)) {
5855 err
= PTR_ERR(event
);
5860 * Special case software events and allow them to be part of
5861 * any hardware group.
5866 (is_software_event(event
) != is_software_event(group_leader
))) {
5867 if (is_software_event(event
)) {
5869 * If event and group_leader are not both a software
5870 * event, and event is, then group leader is not.
5872 * Allow the addition of software events to !software
5873 * groups, this is safe because software events never
5876 pmu
= group_leader
->pmu
;
5877 } else if (is_software_event(group_leader
) &&
5878 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
5880 * In case the group is a pure software group, and we
5881 * try to add a hardware event, move the whole group to
5882 * the hardware context.
5889 * Get the target context (task or percpu):
5891 ctx
= find_get_context(pmu
, task
, cpu
);
5898 * Look up the group leader (we will attach this event to it):
5904 * Do not allow a recursive hierarchy (this new sibling
5905 * becoming part of another group-sibling):
5907 if (group_leader
->group_leader
!= group_leader
)
5910 * Do not allow to attach to a group in a different
5911 * task or CPU context:
5914 if (group_leader
->ctx
->type
!= ctx
->type
)
5917 if (group_leader
->ctx
!= ctx
)
5922 * Only a group leader can be exclusive or pinned
5924 if (attr
.exclusive
|| attr
.pinned
)
5929 err
= perf_event_set_output(event
, output_event
);
5934 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
5935 if (IS_ERR(event_file
)) {
5936 err
= PTR_ERR(event_file
);
5941 struct perf_event_context
*gctx
= group_leader
->ctx
;
5943 mutex_lock(&gctx
->mutex
);
5944 perf_event_remove_from_context(group_leader
);
5945 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
5947 perf_event_remove_from_context(sibling
);
5950 mutex_unlock(&gctx
->mutex
);
5954 event
->filp
= event_file
;
5955 WARN_ON_ONCE(ctx
->parent_ctx
);
5956 mutex_lock(&ctx
->mutex
);
5959 perf_install_in_context(ctx
, group_leader
, cpu
);
5961 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
5963 perf_install_in_context(ctx
, sibling
, cpu
);
5968 perf_install_in_context(ctx
, event
, cpu
);
5970 mutex_unlock(&ctx
->mutex
);
5972 event
->owner
= current
;
5974 mutex_lock(¤t
->perf_event_mutex
);
5975 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
5976 mutex_unlock(¤t
->perf_event_mutex
);
5979 * Precalculate sample_data sizes
5981 perf_event__header_size(event
);
5982 perf_event__id_header_size(event
);
5985 * Drop the reference on the group_event after placing the
5986 * new event on the sibling_list. This ensures destruction
5987 * of the group leader will find the pointer to itself in
5988 * perf_group_detach().
5990 fput_light(group_file
, fput_needed
);
5991 fd_install(event_fd
, event_file
);
6000 put_task_struct(task
);
6002 fput_light(group_file
, fput_needed
);
6004 put_unused_fd(event_fd
);
6009 * perf_event_create_kernel_counter
6011 * @attr: attributes of the counter to create
6012 * @cpu: cpu in which the counter is bound
6013 * @task: task to profile (NULL for percpu)
6016 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6017 struct task_struct
*task
,
6018 perf_overflow_handler_t overflow_handler
)
6020 struct perf_event_context
*ctx
;
6021 struct perf_event
*event
;
6025 * Get the target context (task or percpu):
6028 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
, overflow_handler
);
6029 if (IS_ERR(event
)) {
6030 err
= PTR_ERR(event
);
6034 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6041 WARN_ON_ONCE(ctx
->parent_ctx
);
6042 mutex_lock(&ctx
->mutex
);
6043 perf_install_in_context(ctx
, event
, cpu
);
6045 mutex_unlock(&ctx
->mutex
);
6052 return ERR_PTR(err
);
6054 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6056 static void sync_child_event(struct perf_event
*child_event
,
6057 struct task_struct
*child
)
6059 struct perf_event
*parent_event
= child_event
->parent
;
6062 if (child_event
->attr
.inherit_stat
)
6063 perf_event_read_event(child_event
, child
);
6065 child_val
= perf_event_count(child_event
);
6068 * Add back the child's count to the parent's count:
6070 atomic64_add(child_val
, &parent_event
->child_count
);
6071 atomic64_add(child_event
->total_time_enabled
,
6072 &parent_event
->child_total_time_enabled
);
6073 atomic64_add(child_event
->total_time_running
,
6074 &parent_event
->child_total_time_running
);
6077 * Remove this event from the parent's list
6079 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6080 mutex_lock(&parent_event
->child_mutex
);
6081 list_del_init(&child_event
->child_list
);
6082 mutex_unlock(&parent_event
->child_mutex
);
6085 * Release the parent event, if this was the last
6088 fput(parent_event
->filp
);
6092 __perf_event_exit_task(struct perf_event
*child_event
,
6093 struct perf_event_context
*child_ctx
,
6094 struct task_struct
*child
)
6096 struct perf_event
*parent_event
;
6098 perf_event_remove_from_context(child_event
);
6100 parent_event
= child_event
->parent
;
6102 * It can happen that parent exits first, and has events
6103 * that are still around due to the child reference. These
6104 * events need to be zapped - but otherwise linger.
6107 sync_child_event(child_event
, child
);
6108 free_event(child_event
);
6112 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6114 struct perf_event
*child_event
, *tmp
;
6115 struct perf_event_context
*child_ctx
;
6116 unsigned long flags
;
6118 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6119 perf_event_task(child
, NULL
, 0);
6123 local_irq_save(flags
);
6125 * We can't reschedule here because interrupts are disabled,
6126 * and either child is current or it is a task that can't be
6127 * scheduled, so we are now safe from rescheduling changing
6130 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6131 task_ctx_sched_out(child_ctx
, EVENT_ALL
);
6134 * Take the context lock here so that if find_get_context is
6135 * reading child->perf_event_ctxp, we wait until it has
6136 * incremented the context's refcount before we do put_ctx below.
6138 raw_spin_lock(&child_ctx
->lock
);
6139 child
->perf_event_ctxp
[ctxn
] = NULL
;
6141 * If this context is a clone; unclone it so it can't get
6142 * swapped to another process while we're removing all
6143 * the events from it.
6145 unclone_ctx(child_ctx
);
6146 update_context_time(child_ctx
);
6147 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6150 * Report the task dead after unscheduling the events so that we
6151 * won't get any samples after PERF_RECORD_EXIT. We can however still
6152 * get a few PERF_RECORD_READ events.
6154 perf_event_task(child
, child_ctx
, 0);
6157 * We can recurse on the same lock type through:
6159 * __perf_event_exit_task()
6160 * sync_child_event()
6161 * fput(parent_event->filp)
6163 * mutex_lock(&ctx->mutex)
6165 * But since its the parent context it won't be the same instance.
6167 mutex_lock(&child_ctx
->mutex
);
6170 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6172 __perf_event_exit_task(child_event
, child_ctx
, child
);
6174 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6176 __perf_event_exit_task(child_event
, child_ctx
, child
);
6179 * If the last event was a group event, it will have appended all
6180 * its siblings to the list, but we obtained 'tmp' before that which
6181 * will still point to the list head terminating the iteration.
6183 if (!list_empty(&child_ctx
->pinned_groups
) ||
6184 !list_empty(&child_ctx
->flexible_groups
))
6187 mutex_unlock(&child_ctx
->mutex
);
6193 * When a child task exits, feed back event values to parent events.
6195 void perf_event_exit_task(struct task_struct
*child
)
6197 struct perf_event
*event
, *tmp
;
6200 mutex_lock(&child
->perf_event_mutex
);
6201 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6203 list_del_init(&event
->owner_entry
);
6206 * Ensure the list deletion is visible before we clear
6207 * the owner, closes a race against perf_release() where
6208 * we need to serialize on the owner->perf_event_mutex.
6211 event
->owner
= NULL
;
6213 mutex_unlock(&child
->perf_event_mutex
);
6215 for_each_task_context_nr(ctxn
)
6216 perf_event_exit_task_context(child
, ctxn
);
6219 static void perf_free_event(struct perf_event
*event
,
6220 struct perf_event_context
*ctx
)
6222 struct perf_event
*parent
= event
->parent
;
6224 if (WARN_ON_ONCE(!parent
))
6227 mutex_lock(&parent
->child_mutex
);
6228 list_del_init(&event
->child_list
);
6229 mutex_unlock(&parent
->child_mutex
);
6233 perf_group_detach(event
);
6234 list_del_event(event
, ctx
);
6239 * free an unexposed, unused context as created by inheritance by
6240 * perf_event_init_task below, used by fork() in case of fail.
6242 void perf_event_free_task(struct task_struct
*task
)
6244 struct perf_event_context
*ctx
;
6245 struct perf_event
*event
, *tmp
;
6248 for_each_task_context_nr(ctxn
) {
6249 ctx
= task
->perf_event_ctxp
[ctxn
];
6253 mutex_lock(&ctx
->mutex
);
6255 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6257 perf_free_event(event
, ctx
);
6259 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6261 perf_free_event(event
, ctx
);
6263 if (!list_empty(&ctx
->pinned_groups
) ||
6264 !list_empty(&ctx
->flexible_groups
))
6267 mutex_unlock(&ctx
->mutex
);
6273 void perf_event_delayed_put(struct task_struct
*task
)
6277 for_each_task_context_nr(ctxn
)
6278 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6282 * inherit a event from parent task to child task:
6284 static struct perf_event
*
6285 inherit_event(struct perf_event
*parent_event
,
6286 struct task_struct
*parent
,
6287 struct perf_event_context
*parent_ctx
,
6288 struct task_struct
*child
,
6289 struct perf_event
*group_leader
,
6290 struct perf_event_context
*child_ctx
)
6292 struct perf_event
*child_event
;
6293 unsigned long flags
;
6296 * Instead of creating recursive hierarchies of events,
6297 * we link inherited events back to the original parent,
6298 * which has a filp for sure, which we use as the reference
6301 if (parent_event
->parent
)
6302 parent_event
= parent_event
->parent
;
6304 child_event
= perf_event_alloc(&parent_event
->attr
,
6307 group_leader
, parent_event
,
6309 if (IS_ERR(child_event
))
6314 * Make the child state follow the state of the parent event,
6315 * not its attr.disabled bit. We hold the parent's mutex,
6316 * so we won't race with perf_event_{en, dis}able_family.
6318 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6319 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6321 child_event
->state
= PERF_EVENT_STATE_OFF
;
6323 if (parent_event
->attr
.freq
) {
6324 u64 sample_period
= parent_event
->hw
.sample_period
;
6325 struct hw_perf_event
*hwc
= &child_event
->hw
;
6327 hwc
->sample_period
= sample_period
;
6328 hwc
->last_period
= sample_period
;
6330 local64_set(&hwc
->period_left
, sample_period
);
6333 child_event
->ctx
= child_ctx
;
6334 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6337 * Precalculate sample_data sizes
6339 perf_event__header_size(child_event
);
6340 perf_event__id_header_size(child_event
);
6343 * Link it up in the child's context:
6345 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6346 add_event_to_ctx(child_event
, child_ctx
);
6347 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6350 * Get a reference to the parent filp - we will fput it
6351 * when the child event exits. This is safe to do because
6352 * we are in the parent and we know that the filp still
6353 * exists and has a nonzero count:
6355 atomic_long_inc(&parent_event
->filp
->f_count
);
6358 * Link this into the parent event's child list
6360 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6361 mutex_lock(&parent_event
->child_mutex
);
6362 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
6363 mutex_unlock(&parent_event
->child_mutex
);
6368 static int inherit_group(struct perf_event
*parent_event
,
6369 struct task_struct
*parent
,
6370 struct perf_event_context
*parent_ctx
,
6371 struct task_struct
*child
,
6372 struct perf_event_context
*child_ctx
)
6374 struct perf_event
*leader
;
6375 struct perf_event
*sub
;
6376 struct perf_event
*child_ctr
;
6378 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
6379 child
, NULL
, child_ctx
);
6381 return PTR_ERR(leader
);
6382 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
6383 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
6384 child
, leader
, child_ctx
);
6385 if (IS_ERR(child_ctr
))
6386 return PTR_ERR(child_ctr
);
6392 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
6393 struct perf_event_context
*parent_ctx
,
6394 struct task_struct
*child
, int ctxn
,
6398 struct perf_event_context
*child_ctx
;
6400 if (!event
->attr
.inherit
) {
6405 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6408 * This is executed from the parent task context, so
6409 * inherit events that have been marked for cloning.
6410 * First allocate and initialize a context for the
6414 child_ctx
= alloc_perf_context(event
->pmu
, child
);
6418 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
6421 ret
= inherit_group(event
, parent
, parent_ctx
,
6431 * Initialize the perf_event context in task_struct
6433 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
6435 struct perf_event_context
*child_ctx
, *parent_ctx
;
6436 struct perf_event_context
*cloned_ctx
;
6437 struct perf_event
*event
;
6438 struct task_struct
*parent
= current
;
6439 int inherited_all
= 1;
6440 unsigned long flags
;
6443 child
->perf_event_ctxp
[ctxn
] = NULL
;
6445 mutex_init(&child
->perf_event_mutex
);
6446 INIT_LIST_HEAD(&child
->perf_event_list
);
6448 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
6452 * If the parent's context is a clone, pin it so it won't get
6455 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
6458 * No need to check if parent_ctx != NULL here; since we saw
6459 * it non-NULL earlier, the only reason for it to become NULL
6460 * is if we exit, and since we're currently in the middle of
6461 * a fork we can't be exiting at the same time.
6465 * Lock the parent list. No need to lock the child - not PID
6466 * hashed yet and not running, so nobody can access it.
6468 mutex_lock(&parent_ctx
->mutex
);
6471 * We dont have to disable NMIs - we are only looking at
6472 * the list, not manipulating it:
6474 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
6475 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6476 child
, ctxn
, &inherited_all
);
6482 * We can't hold ctx->lock when iterating the ->flexible_group list due
6483 * to allocations, but we need to prevent rotation because
6484 * rotate_ctx() will change the list from interrupt context.
6486 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6487 parent_ctx
->rotate_disable
= 1;
6488 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6490 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
6491 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6492 child
, ctxn
, &inherited_all
);
6497 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6498 parent_ctx
->rotate_disable
= 0;
6500 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6502 if (child_ctx
&& inherited_all
) {
6504 * Mark the child context as a clone of the parent
6505 * context, or of whatever the parent is a clone of.
6507 * Note that if the parent is a clone, the holding of
6508 * parent_ctx->lock avoids it from being uncloned.
6510 cloned_ctx
= parent_ctx
->parent_ctx
;
6512 child_ctx
->parent_ctx
= cloned_ctx
;
6513 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
6515 child_ctx
->parent_ctx
= parent_ctx
;
6516 child_ctx
->parent_gen
= parent_ctx
->generation
;
6518 get_ctx(child_ctx
->parent_ctx
);
6521 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6522 mutex_unlock(&parent_ctx
->mutex
);
6524 perf_unpin_context(parent_ctx
);
6530 * Initialize the perf_event context in task_struct
6532 int perf_event_init_task(struct task_struct
*child
)
6536 for_each_task_context_nr(ctxn
) {
6537 ret
= perf_event_init_context(child
, ctxn
);
6545 static void __init
perf_event_init_all_cpus(void)
6547 struct swevent_htable
*swhash
;
6550 for_each_possible_cpu(cpu
) {
6551 swhash
= &per_cpu(swevent_htable
, cpu
);
6552 mutex_init(&swhash
->hlist_mutex
);
6553 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
6557 static void __cpuinit
perf_event_init_cpu(int cpu
)
6559 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6561 mutex_lock(&swhash
->hlist_mutex
);
6562 if (swhash
->hlist_refcount
> 0) {
6563 struct swevent_hlist
*hlist
;
6565 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
6567 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6569 mutex_unlock(&swhash
->hlist_mutex
);
6572 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
6573 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
6575 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6577 WARN_ON(!irqs_disabled());
6579 list_del_init(&cpuctx
->rotation_list
);
6582 static void __perf_event_exit_context(void *__info
)
6584 struct perf_event_context
*ctx
= __info
;
6585 struct perf_event
*event
, *tmp
;
6587 perf_pmu_rotate_stop(ctx
->pmu
);
6589 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
6590 __perf_event_remove_from_context(event
);
6591 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
6592 __perf_event_remove_from_context(event
);
6595 static void perf_event_exit_cpu_context(int cpu
)
6597 struct perf_event_context
*ctx
;
6601 idx
= srcu_read_lock(&pmus_srcu
);
6602 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6603 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
6605 mutex_lock(&ctx
->mutex
);
6606 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
6607 mutex_unlock(&ctx
->mutex
);
6609 srcu_read_unlock(&pmus_srcu
, idx
);
6612 static void perf_event_exit_cpu(int cpu
)
6614 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6616 mutex_lock(&swhash
->hlist_mutex
);
6617 swevent_hlist_release(swhash
);
6618 mutex_unlock(&swhash
->hlist_mutex
);
6620 perf_event_exit_cpu_context(cpu
);
6623 static inline void perf_event_exit_cpu(int cpu
) { }
6627 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
6631 for_each_online_cpu(cpu
)
6632 perf_event_exit_cpu(cpu
);
6638 * Run the perf reboot notifier at the very last possible moment so that
6639 * the generic watchdog code runs as long as possible.
6641 static struct notifier_block perf_reboot_notifier
= {
6642 .notifier_call
= perf_reboot
,
6643 .priority
= INT_MIN
,
6646 static int __cpuinit
6647 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
6649 unsigned int cpu
= (long)hcpu
;
6651 switch (action
& ~CPU_TASKS_FROZEN
) {
6653 case CPU_UP_PREPARE
:
6654 case CPU_DOWN_FAILED
:
6655 perf_event_init_cpu(cpu
);
6658 case CPU_UP_CANCELED
:
6659 case CPU_DOWN_PREPARE
:
6660 perf_event_exit_cpu(cpu
);
6670 void __init
perf_event_init(void)
6676 perf_event_init_all_cpus();
6677 init_srcu_struct(&pmus_srcu
);
6678 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
6679 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
6680 perf_pmu_register(&perf_task_clock
, NULL
, -1);
6682 perf_cpu_notifier(perf_cpu_notify
);
6683 register_reboot_notifier(&perf_reboot_notifier
);
6685 ret
= init_hw_breakpoint();
6686 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
6689 static int __init
perf_event_sysfs_init(void)
6694 mutex_lock(&pmus_lock
);
6696 ret
= bus_register(&pmu_bus
);
6700 list_for_each_entry(pmu
, &pmus
, entry
) {
6701 if (!pmu
->name
|| pmu
->type
< 0)
6704 ret
= pmu_dev_alloc(pmu
);
6705 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
6707 pmu_bus_running
= 1;
6711 mutex_unlock(&pmus_lock
);
6715 device_initcall(perf_event_sysfs_init
);