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 /* Minimum for 512 kiB + 1 user control page */
66 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
69 * max perf event sample rate
71 int sysctl_perf_event_sample_rate __read_mostly
= 100000;
73 static atomic64_t perf_event_id
;
75 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
76 enum event_type_t event_type
);
78 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
79 enum event_type_t event_type
);
81 void __weak
perf_event_print_debug(void) { }
83 extern __weak
const char *perf_pmu_name(void)
88 static inline u64
perf_clock(void)
93 void perf_pmu_disable(struct pmu
*pmu
)
95 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
97 pmu
->pmu_disable(pmu
);
100 void perf_pmu_enable(struct pmu
*pmu
)
102 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
104 pmu
->pmu_enable(pmu
);
107 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
110 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
111 * because they're strictly cpu affine and rotate_start is called with IRQs
112 * disabled, while rotate_context is called from IRQ context.
114 static void perf_pmu_rotate_start(struct pmu
*pmu
)
116 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
117 struct list_head
*head
= &__get_cpu_var(rotation_list
);
119 WARN_ON(!irqs_disabled());
121 if (list_empty(&cpuctx
->rotation_list
))
122 list_add(&cpuctx
->rotation_list
, head
);
125 static void get_ctx(struct perf_event_context
*ctx
)
127 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
130 static void free_ctx(struct rcu_head
*head
)
132 struct perf_event_context
*ctx
;
134 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
138 static void put_ctx(struct perf_event_context
*ctx
)
140 if (atomic_dec_and_test(&ctx
->refcount
)) {
142 put_ctx(ctx
->parent_ctx
);
144 put_task_struct(ctx
->task
);
145 call_rcu(&ctx
->rcu_head
, free_ctx
);
149 static void unclone_ctx(struct perf_event_context
*ctx
)
151 if (ctx
->parent_ctx
) {
152 put_ctx(ctx
->parent_ctx
);
153 ctx
->parent_ctx
= NULL
;
157 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
160 * only top level events have the pid namespace they were created in
163 event
= event
->parent
;
165 return task_tgid_nr_ns(p
, event
->ns
);
168 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
171 * only top level events have the pid namespace they were created in
174 event
= event
->parent
;
176 return task_pid_nr_ns(p
, event
->ns
);
180 * If we inherit events we want to return the parent event id
183 static u64
primary_event_id(struct perf_event
*event
)
188 id
= event
->parent
->id
;
194 * Get the perf_event_context for a task and lock it.
195 * This has to cope with with the fact that until it is locked,
196 * the context could get moved to another task.
198 static struct perf_event_context
*
199 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
201 struct perf_event_context
*ctx
;
205 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
208 * If this context is a clone of another, it might
209 * get swapped for another underneath us by
210 * perf_event_task_sched_out, though the
211 * rcu_read_lock() protects us from any context
212 * getting freed. Lock the context and check if it
213 * got swapped before we could get the lock, and retry
214 * if so. If we locked the right context, then it
215 * can't get swapped on us any more.
217 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
218 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
219 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
223 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
224 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
233 * Get the context for a task and increment its pin_count so it
234 * can't get swapped to another task. This also increments its
235 * reference count so that the context can't get freed.
237 static struct perf_event_context
*
238 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
240 struct perf_event_context
*ctx
;
243 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
246 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
251 static void perf_unpin_context(struct perf_event_context
*ctx
)
255 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
257 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
262 * Update the record of the current time in a context.
264 static void update_context_time(struct perf_event_context
*ctx
)
266 u64 now
= perf_clock();
268 ctx
->time
+= now
- ctx
->timestamp
;
269 ctx
->timestamp
= now
;
272 static u64
perf_event_time(struct perf_event
*event
)
274 struct perf_event_context
*ctx
= event
->ctx
;
275 return ctx
? ctx
->time
: 0;
279 * Update the total_time_enabled and total_time_running fields for a event.
281 static void update_event_times(struct perf_event
*event
)
283 struct perf_event_context
*ctx
= event
->ctx
;
286 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
287 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
291 run_end
= perf_event_time(event
);
293 run_end
= event
->tstamp_stopped
;
295 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
297 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
298 run_end
= event
->tstamp_stopped
;
300 run_end
= perf_event_time(event
);
302 event
->total_time_running
= run_end
- event
->tstamp_running
;
306 * Update total_time_enabled and total_time_running for all events in a group.
308 static void update_group_times(struct perf_event
*leader
)
310 struct perf_event
*event
;
312 update_event_times(leader
);
313 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
314 update_event_times(event
);
317 static struct list_head
*
318 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
320 if (event
->attr
.pinned
)
321 return &ctx
->pinned_groups
;
323 return &ctx
->flexible_groups
;
327 * Add a event from the lists for its context.
328 * Must be called with ctx->mutex and ctx->lock held.
331 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
333 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
334 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
337 * If we're a stand alone event or group leader, we go to the context
338 * list, group events are kept attached to the group so that
339 * perf_group_detach can, at all times, locate all siblings.
341 if (event
->group_leader
== event
) {
342 struct list_head
*list
;
344 if (is_software_event(event
))
345 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
347 list
= ctx_group_list(event
, ctx
);
348 list_add_tail(&event
->group_entry
, list
);
351 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
353 perf_pmu_rotate_start(ctx
->pmu
);
355 if (event
->attr
.inherit_stat
)
360 * Called at perf_event creation and when events are attached/detached from a
363 static void perf_event__read_size(struct perf_event
*event
)
365 int entry
= sizeof(u64
); /* value */
369 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
372 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
375 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
376 entry
+= sizeof(u64
);
378 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
379 nr
+= event
->group_leader
->nr_siblings
;
384 event
->read_size
= size
;
387 static void perf_event__header_size(struct perf_event
*event
)
389 struct perf_sample_data
*data
;
390 u64 sample_type
= event
->attr
.sample_type
;
393 perf_event__read_size(event
);
395 if (sample_type
& PERF_SAMPLE_IP
)
396 size
+= sizeof(data
->ip
);
398 if (sample_type
& PERF_SAMPLE_ADDR
)
399 size
+= sizeof(data
->addr
);
401 if (sample_type
& PERF_SAMPLE_PERIOD
)
402 size
+= sizeof(data
->period
);
404 if (sample_type
& PERF_SAMPLE_READ
)
405 size
+= event
->read_size
;
407 event
->header_size
= size
;
410 static void perf_event__id_header_size(struct perf_event
*event
)
412 struct perf_sample_data
*data
;
413 u64 sample_type
= event
->attr
.sample_type
;
416 if (sample_type
& PERF_SAMPLE_TID
)
417 size
+= sizeof(data
->tid_entry
);
419 if (sample_type
& PERF_SAMPLE_TIME
)
420 size
+= sizeof(data
->time
);
422 if (sample_type
& PERF_SAMPLE_ID
)
423 size
+= sizeof(data
->id
);
425 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
426 size
+= sizeof(data
->stream_id
);
428 if (sample_type
& PERF_SAMPLE_CPU
)
429 size
+= sizeof(data
->cpu_entry
);
431 event
->id_header_size
= size
;
434 static void perf_group_attach(struct perf_event
*event
)
436 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
439 * We can have double attach due to group movement in perf_event_open.
441 if (event
->attach_state
& PERF_ATTACH_GROUP
)
444 event
->attach_state
|= PERF_ATTACH_GROUP
;
446 if (group_leader
== event
)
449 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
450 !is_software_event(event
))
451 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
453 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
454 group_leader
->nr_siblings
++;
456 perf_event__header_size(group_leader
);
458 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
459 perf_event__header_size(pos
);
463 * Remove a event from the lists for its context.
464 * Must be called with ctx->mutex and ctx->lock held.
467 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
470 * We can have double detach due to exit/hot-unplug + close.
472 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
475 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
478 if (event
->attr
.inherit_stat
)
481 list_del_rcu(&event
->event_entry
);
483 if (event
->group_leader
== event
)
484 list_del_init(&event
->group_entry
);
486 update_group_times(event
);
489 * If event was in error state, then keep it
490 * that way, otherwise bogus counts will be
491 * returned on read(). The only way to get out
492 * of error state is by explicit re-enabling
495 if (event
->state
> PERF_EVENT_STATE_OFF
)
496 event
->state
= PERF_EVENT_STATE_OFF
;
499 static void perf_group_detach(struct perf_event
*event
)
501 struct perf_event
*sibling
, *tmp
;
502 struct list_head
*list
= NULL
;
505 * We can have double detach due to exit/hot-unplug + close.
507 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
510 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
513 * If this is a sibling, remove it from its group.
515 if (event
->group_leader
!= event
) {
516 list_del_init(&event
->group_entry
);
517 event
->group_leader
->nr_siblings
--;
521 if (!list_empty(&event
->group_entry
))
522 list
= &event
->group_entry
;
525 * If this was a group event with sibling events then
526 * upgrade the siblings to singleton events by adding them
527 * to whatever list we are on.
529 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
531 list_move_tail(&sibling
->group_entry
, list
);
532 sibling
->group_leader
= sibling
;
534 /* Inherit group flags from the previous leader */
535 sibling
->group_flags
= event
->group_flags
;
539 perf_event__header_size(event
->group_leader
);
541 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
542 perf_event__header_size(tmp
);
546 event_filter_match(struct perf_event
*event
)
548 return event
->cpu
== -1 || event
->cpu
== smp_processor_id();
552 event_sched_out(struct perf_event
*event
,
553 struct perf_cpu_context
*cpuctx
,
554 struct perf_event_context
*ctx
)
556 u64 tstamp
= perf_event_time(event
);
559 * An event which could not be activated because of
560 * filter mismatch still needs to have its timings
561 * maintained, otherwise bogus information is return
562 * via read() for time_enabled, time_running:
564 if (event
->state
== PERF_EVENT_STATE_INACTIVE
565 && !event_filter_match(event
)) {
566 delta
= ctx
->time
- event
->tstamp_stopped
;
567 event
->tstamp_running
+= delta
;
568 event
->tstamp_stopped
= tstamp
;
571 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
574 event
->state
= PERF_EVENT_STATE_INACTIVE
;
575 if (event
->pending_disable
) {
576 event
->pending_disable
= 0;
577 event
->state
= PERF_EVENT_STATE_OFF
;
579 event
->tstamp_stopped
= tstamp
;
580 event
->pmu
->del(event
, 0);
583 if (!is_software_event(event
))
584 cpuctx
->active_oncpu
--;
586 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
587 cpuctx
->exclusive
= 0;
591 group_sched_out(struct perf_event
*group_event
,
592 struct perf_cpu_context
*cpuctx
,
593 struct perf_event_context
*ctx
)
595 struct perf_event
*event
;
596 int state
= group_event
->state
;
598 event_sched_out(group_event
, cpuctx
, ctx
);
601 * Schedule out siblings (if any):
603 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
604 event_sched_out(event
, cpuctx
, ctx
);
606 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
607 cpuctx
->exclusive
= 0;
610 static inline struct perf_cpu_context
*
611 __get_cpu_context(struct perf_event_context
*ctx
)
613 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
617 * Cross CPU call to remove a performance event
619 * We disable the event on the hardware level first. After that we
620 * remove it from the context list.
622 static void __perf_event_remove_from_context(void *info
)
624 struct perf_event
*event
= info
;
625 struct perf_event_context
*ctx
= event
->ctx
;
626 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
629 * If this is a task context, we need to check whether it is
630 * the current task context of this cpu. If not it has been
631 * scheduled out before the smp call arrived.
633 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
636 raw_spin_lock(&ctx
->lock
);
638 event_sched_out(event
, cpuctx
, ctx
);
640 list_del_event(event
, ctx
);
642 raw_spin_unlock(&ctx
->lock
);
647 * Remove the event from a task's (or a CPU's) list of events.
649 * Must be called with ctx->mutex held.
651 * CPU events are removed with a smp call. For task events we only
652 * call when the task is on a CPU.
654 * If event->ctx is a cloned context, callers must make sure that
655 * every task struct that event->ctx->task could possibly point to
656 * remains valid. This is OK when called from perf_release since
657 * that only calls us on the top-level context, which can't be a clone.
658 * When called from perf_event_exit_task, it's OK because the
659 * context has been detached from its task.
661 static void perf_event_remove_from_context(struct perf_event
*event
)
663 struct perf_event_context
*ctx
= event
->ctx
;
664 struct task_struct
*task
= ctx
->task
;
668 * Per cpu events are removed via an smp call and
669 * the removal is always successful.
671 smp_call_function_single(event
->cpu
,
672 __perf_event_remove_from_context
,
678 task_oncpu_function_call(task
, __perf_event_remove_from_context
,
681 raw_spin_lock_irq(&ctx
->lock
);
683 * If the context is active we need to retry the smp call.
685 if (ctx
->nr_active
&& !list_empty(&event
->group_entry
)) {
686 raw_spin_unlock_irq(&ctx
->lock
);
691 * The lock prevents that this context is scheduled in so we
692 * can remove the event safely, if the call above did not
695 if (!list_empty(&event
->group_entry
))
696 list_del_event(event
, ctx
);
697 raw_spin_unlock_irq(&ctx
->lock
);
701 * Cross CPU call to disable a performance event
703 static void __perf_event_disable(void *info
)
705 struct perf_event
*event
= info
;
706 struct perf_event_context
*ctx
= event
->ctx
;
707 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
710 * If this is a per-task event, need to check whether this
711 * event's task is the current task on this cpu.
713 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
716 raw_spin_lock(&ctx
->lock
);
719 * If the event is on, turn it off.
720 * If it is in error state, leave it in error state.
722 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
723 update_context_time(ctx
);
724 update_group_times(event
);
725 if (event
== event
->group_leader
)
726 group_sched_out(event
, cpuctx
, ctx
);
728 event_sched_out(event
, cpuctx
, ctx
);
729 event
->state
= PERF_EVENT_STATE_OFF
;
732 raw_spin_unlock(&ctx
->lock
);
738 * If event->ctx is a cloned context, callers must make sure that
739 * every task struct that event->ctx->task could possibly point to
740 * remains valid. This condition is satisifed when called through
741 * perf_event_for_each_child or perf_event_for_each because they
742 * hold the top-level event's child_mutex, so any descendant that
743 * goes to exit will block in sync_child_event.
744 * When called from perf_pending_event it's OK because event->ctx
745 * is the current context on this CPU and preemption is disabled,
746 * hence we can't get into perf_event_task_sched_out for this context.
748 void perf_event_disable(struct perf_event
*event
)
750 struct perf_event_context
*ctx
= event
->ctx
;
751 struct task_struct
*task
= ctx
->task
;
755 * Disable the event on the cpu that it's on
757 smp_call_function_single(event
->cpu
, __perf_event_disable
,
763 task_oncpu_function_call(task
, __perf_event_disable
, event
);
765 raw_spin_lock_irq(&ctx
->lock
);
767 * If the event is still active, we need to retry the cross-call.
769 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
770 raw_spin_unlock_irq(&ctx
->lock
);
775 * Since we have the lock this context can't be scheduled
776 * in, so we can change the state safely.
778 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
779 update_group_times(event
);
780 event
->state
= PERF_EVENT_STATE_OFF
;
783 raw_spin_unlock_irq(&ctx
->lock
);
786 #define MAX_INTERRUPTS (~0ULL)
788 static void perf_log_throttle(struct perf_event
*event
, int enable
);
791 event_sched_in(struct perf_event
*event
,
792 struct perf_cpu_context
*cpuctx
,
793 struct perf_event_context
*ctx
)
795 u64 tstamp
= perf_event_time(event
);
797 if (event
->state
<= PERF_EVENT_STATE_OFF
)
800 event
->state
= PERF_EVENT_STATE_ACTIVE
;
801 event
->oncpu
= smp_processor_id();
804 * Unthrottle events, since we scheduled we might have missed several
805 * ticks already, also for a heavily scheduling task there is little
806 * guarantee it'll get a tick in a timely manner.
808 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
809 perf_log_throttle(event
, 1);
810 event
->hw
.interrupts
= 0;
814 * The new state must be visible before we turn it on in the hardware:
818 if (event
->pmu
->add(event
, PERF_EF_START
)) {
819 event
->state
= PERF_EVENT_STATE_INACTIVE
;
824 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
826 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
828 if (!is_software_event(event
))
829 cpuctx
->active_oncpu
++;
832 if (event
->attr
.exclusive
)
833 cpuctx
->exclusive
= 1;
839 group_sched_in(struct perf_event
*group_event
,
840 struct perf_cpu_context
*cpuctx
,
841 struct perf_event_context
*ctx
)
843 struct perf_event
*event
, *partial_group
= NULL
;
844 struct pmu
*pmu
= group_event
->pmu
;
846 bool simulate
= false;
848 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
853 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
854 pmu
->cancel_txn(pmu
);
859 * Schedule in siblings as one group (if any):
861 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
862 if (event_sched_in(event
, cpuctx
, ctx
)) {
863 partial_group
= event
;
868 if (!pmu
->commit_txn(pmu
))
873 * Groups can be scheduled in as one unit only, so undo any
874 * partial group before returning:
875 * The events up to the failed event are scheduled out normally,
876 * tstamp_stopped will be updated.
878 * The failed events and the remaining siblings need to have
879 * their timings updated as if they had gone thru event_sched_in()
880 * and event_sched_out(). This is required to get consistent timings
881 * across the group. This also takes care of the case where the group
882 * could never be scheduled by ensuring tstamp_stopped is set to mark
883 * the time the event was actually stopped, such that time delta
884 * calculation in update_event_times() is correct.
886 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
887 if (event
== partial_group
)
891 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
892 event
->tstamp_stopped
= now
;
894 event_sched_out(event
, cpuctx
, ctx
);
897 event_sched_out(group_event
, cpuctx
, ctx
);
899 pmu
->cancel_txn(pmu
);
905 * Work out whether we can put this event group on the CPU now.
907 static int group_can_go_on(struct perf_event
*event
,
908 struct perf_cpu_context
*cpuctx
,
912 * Groups consisting entirely of software events can always go on.
914 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
917 * If an exclusive group is already on, no other hardware
920 if (cpuctx
->exclusive
)
923 * If this group is exclusive and there are already
924 * events on the CPU, it can't go on.
926 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
929 * Otherwise, try to add it if all previous groups were able
935 static void add_event_to_ctx(struct perf_event
*event
,
936 struct perf_event_context
*ctx
)
938 u64 tstamp
= perf_event_time(event
);
940 list_add_event(event
, ctx
);
941 perf_group_attach(event
);
942 event
->tstamp_enabled
= tstamp
;
943 event
->tstamp_running
= tstamp
;
944 event
->tstamp_stopped
= tstamp
;
948 * Cross CPU call to install and enable a performance event
950 * Must be called with ctx->mutex held
952 static void __perf_install_in_context(void *info
)
954 struct perf_event
*event
= info
;
955 struct perf_event_context
*ctx
= event
->ctx
;
956 struct perf_event
*leader
= event
->group_leader
;
957 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
961 * If this is a task context, we need to check whether it is
962 * the current task context of this cpu. If not it has been
963 * scheduled out before the smp call arrived.
964 * Or possibly this is the right context but it isn't
965 * on this cpu because it had no events.
967 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
968 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
970 cpuctx
->task_ctx
= ctx
;
973 raw_spin_lock(&ctx
->lock
);
975 update_context_time(ctx
);
977 add_event_to_ctx(event
, ctx
);
979 if (!event_filter_match(event
))
983 * Don't put the event on if it is disabled or if
984 * it is in a group and the group isn't on.
986 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
987 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
991 * An exclusive event can't go on if there are already active
992 * hardware events, and no hardware event can go on if there
993 * is already an exclusive event on.
995 if (!group_can_go_on(event
, cpuctx
, 1))
998 err
= event_sched_in(event
, cpuctx
, ctx
);
1002 * This event couldn't go on. If it is in a group
1003 * then we have to pull the whole group off.
1004 * If the event group is pinned then put it in error state.
1006 if (leader
!= event
)
1007 group_sched_out(leader
, cpuctx
, ctx
);
1008 if (leader
->attr
.pinned
) {
1009 update_group_times(leader
);
1010 leader
->state
= PERF_EVENT_STATE_ERROR
;
1015 raw_spin_unlock(&ctx
->lock
);
1019 * Attach a performance event to a context
1021 * First we add the event to the list with the hardware enable bit
1022 * in event->hw_config cleared.
1024 * If the event is attached to a task which is on a CPU we use a smp
1025 * call to enable it in the task context. The task might have been
1026 * scheduled away, but we check this in the smp call again.
1028 * Must be called with ctx->mutex held.
1031 perf_install_in_context(struct perf_event_context
*ctx
,
1032 struct perf_event
*event
,
1035 struct task_struct
*task
= ctx
->task
;
1041 * Per cpu events are installed via an smp call and
1042 * the install is always successful.
1044 smp_call_function_single(cpu
, __perf_install_in_context
,
1050 task_oncpu_function_call(task
, __perf_install_in_context
,
1053 raw_spin_lock_irq(&ctx
->lock
);
1055 * we need to retry the smp call.
1057 if (ctx
->is_active
&& list_empty(&event
->group_entry
)) {
1058 raw_spin_unlock_irq(&ctx
->lock
);
1063 * The lock prevents that this context is scheduled in so we
1064 * can add the event safely, if it the call above did not
1067 if (list_empty(&event
->group_entry
))
1068 add_event_to_ctx(event
, ctx
);
1069 raw_spin_unlock_irq(&ctx
->lock
);
1073 * Put a event into inactive state and update time fields.
1074 * Enabling the leader of a group effectively enables all
1075 * the group members that aren't explicitly disabled, so we
1076 * have to update their ->tstamp_enabled also.
1077 * Note: this works for group members as well as group leaders
1078 * since the non-leader members' sibling_lists will be empty.
1080 static void __perf_event_mark_enabled(struct perf_event
*event
,
1081 struct perf_event_context
*ctx
)
1083 struct perf_event
*sub
;
1084 u64 tstamp
= perf_event_time(event
);
1086 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1087 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1088 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1089 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1090 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1095 * Cross CPU call to enable a performance event
1097 static void __perf_event_enable(void *info
)
1099 struct perf_event
*event
= info
;
1100 struct perf_event_context
*ctx
= event
->ctx
;
1101 struct perf_event
*leader
= event
->group_leader
;
1102 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1106 * If this is a per-task event, need to check whether this
1107 * event's task is the current task on this cpu.
1109 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
) {
1110 if (cpuctx
->task_ctx
|| ctx
->task
!= current
)
1112 cpuctx
->task_ctx
= ctx
;
1115 raw_spin_lock(&ctx
->lock
);
1117 update_context_time(ctx
);
1119 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1121 __perf_event_mark_enabled(event
, ctx
);
1123 if (!event_filter_match(event
))
1127 * If the event is in a group and isn't the group leader,
1128 * then don't put it on unless the group is on.
1130 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1133 if (!group_can_go_on(event
, cpuctx
, 1)) {
1136 if (event
== leader
)
1137 err
= group_sched_in(event
, cpuctx
, ctx
);
1139 err
= event_sched_in(event
, cpuctx
, ctx
);
1144 * If this event can't go on and it's part of a
1145 * group, then the whole group has to come off.
1147 if (leader
!= event
)
1148 group_sched_out(leader
, cpuctx
, ctx
);
1149 if (leader
->attr
.pinned
) {
1150 update_group_times(leader
);
1151 leader
->state
= PERF_EVENT_STATE_ERROR
;
1156 raw_spin_unlock(&ctx
->lock
);
1162 * If event->ctx is a cloned context, callers must make sure that
1163 * every task struct that event->ctx->task could possibly point to
1164 * remains valid. This condition is satisfied when called through
1165 * perf_event_for_each_child or perf_event_for_each as described
1166 * for perf_event_disable.
1168 void perf_event_enable(struct perf_event
*event
)
1170 struct perf_event_context
*ctx
= event
->ctx
;
1171 struct task_struct
*task
= ctx
->task
;
1175 * Enable the event on the cpu that it's on
1177 smp_call_function_single(event
->cpu
, __perf_event_enable
,
1182 raw_spin_lock_irq(&ctx
->lock
);
1183 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1187 * If the event is in error state, clear that first.
1188 * That way, if we see the event in error state below, we
1189 * know that it has gone back into error state, as distinct
1190 * from the task having been scheduled away before the
1191 * cross-call arrived.
1193 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1194 event
->state
= PERF_EVENT_STATE_OFF
;
1197 raw_spin_unlock_irq(&ctx
->lock
);
1198 task_oncpu_function_call(task
, __perf_event_enable
, event
);
1200 raw_spin_lock_irq(&ctx
->lock
);
1203 * If the context is active and the event is still off,
1204 * we need to retry the cross-call.
1206 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
)
1210 * Since we have the lock this context can't be scheduled
1211 * in, so we can change the state safely.
1213 if (event
->state
== PERF_EVENT_STATE_OFF
)
1214 __perf_event_mark_enabled(event
, ctx
);
1217 raw_spin_unlock_irq(&ctx
->lock
);
1220 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1223 * not supported on inherited events
1225 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1228 atomic_add(refresh
, &event
->event_limit
);
1229 perf_event_enable(event
);
1234 static void ctx_sched_out(struct perf_event_context
*ctx
,
1235 struct perf_cpu_context
*cpuctx
,
1236 enum event_type_t event_type
)
1238 struct perf_event
*event
;
1240 raw_spin_lock(&ctx
->lock
);
1241 perf_pmu_disable(ctx
->pmu
);
1243 if (likely(!ctx
->nr_events
))
1245 update_context_time(ctx
);
1247 if (!ctx
->nr_active
)
1250 if (event_type
& EVENT_PINNED
) {
1251 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1252 group_sched_out(event
, cpuctx
, ctx
);
1255 if (event_type
& EVENT_FLEXIBLE
) {
1256 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1257 group_sched_out(event
, cpuctx
, ctx
);
1260 perf_pmu_enable(ctx
->pmu
);
1261 raw_spin_unlock(&ctx
->lock
);
1265 * Test whether two contexts are equivalent, i.e. whether they
1266 * have both been cloned from the same version of the same context
1267 * and they both have the same number of enabled events.
1268 * If the number of enabled events is the same, then the set
1269 * of enabled events should be the same, because these are both
1270 * inherited contexts, therefore we can't access individual events
1271 * in them directly with an fd; we can only enable/disable all
1272 * events via prctl, or enable/disable all events in a family
1273 * via ioctl, which will have the same effect on both contexts.
1275 static int context_equiv(struct perf_event_context
*ctx1
,
1276 struct perf_event_context
*ctx2
)
1278 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1279 && ctx1
->parent_gen
== ctx2
->parent_gen
1280 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1283 static void __perf_event_sync_stat(struct perf_event
*event
,
1284 struct perf_event
*next_event
)
1288 if (!event
->attr
.inherit_stat
)
1292 * Update the event value, we cannot use perf_event_read()
1293 * because we're in the middle of a context switch and have IRQs
1294 * disabled, which upsets smp_call_function_single(), however
1295 * we know the event must be on the current CPU, therefore we
1296 * don't need to use it.
1298 switch (event
->state
) {
1299 case PERF_EVENT_STATE_ACTIVE
:
1300 event
->pmu
->read(event
);
1303 case PERF_EVENT_STATE_INACTIVE
:
1304 update_event_times(event
);
1312 * In order to keep per-task stats reliable we need to flip the event
1313 * values when we flip the contexts.
1315 value
= local64_read(&next_event
->count
);
1316 value
= local64_xchg(&event
->count
, value
);
1317 local64_set(&next_event
->count
, value
);
1319 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1320 swap(event
->total_time_running
, next_event
->total_time_running
);
1323 * Since we swizzled the values, update the user visible data too.
1325 perf_event_update_userpage(event
);
1326 perf_event_update_userpage(next_event
);
1329 #define list_next_entry(pos, member) \
1330 list_entry(pos->member.next, typeof(*pos), member)
1332 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1333 struct perf_event_context
*next_ctx
)
1335 struct perf_event
*event
, *next_event
;
1340 update_context_time(ctx
);
1342 event
= list_first_entry(&ctx
->event_list
,
1343 struct perf_event
, event_entry
);
1345 next_event
= list_first_entry(&next_ctx
->event_list
,
1346 struct perf_event
, event_entry
);
1348 while (&event
->event_entry
!= &ctx
->event_list
&&
1349 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1351 __perf_event_sync_stat(event
, next_event
);
1353 event
= list_next_entry(event
, event_entry
);
1354 next_event
= list_next_entry(next_event
, event_entry
);
1358 void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
1359 struct task_struct
*next
)
1361 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
1362 struct perf_event_context
*next_ctx
;
1363 struct perf_event_context
*parent
;
1364 struct perf_cpu_context
*cpuctx
;
1370 cpuctx
= __get_cpu_context(ctx
);
1371 if (!cpuctx
->task_ctx
)
1375 parent
= rcu_dereference(ctx
->parent_ctx
);
1376 next_ctx
= next
->perf_event_ctxp
[ctxn
];
1377 if (parent
&& next_ctx
&&
1378 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1380 * Looks like the two contexts are clones, so we might be
1381 * able to optimize the context switch. We lock both
1382 * contexts and check that they are clones under the
1383 * lock (including re-checking that neither has been
1384 * uncloned in the meantime). It doesn't matter which
1385 * order we take the locks because no other cpu could
1386 * be trying to lock both of these tasks.
1388 raw_spin_lock(&ctx
->lock
);
1389 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1390 if (context_equiv(ctx
, next_ctx
)) {
1392 * XXX do we need a memory barrier of sorts
1393 * wrt to rcu_dereference() of perf_event_ctxp
1395 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
1396 next
->perf_event_ctxp
[ctxn
] = ctx
;
1398 next_ctx
->task
= task
;
1401 perf_event_sync_stat(ctx
, next_ctx
);
1403 raw_spin_unlock(&next_ctx
->lock
);
1404 raw_spin_unlock(&ctx
->lock
);
1409 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1410 cpuctx
->task_ctx
= NULL
;
1414 #define for_each_task_context_nr(ctxn) \
1415 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
1418 * Called from scheduler to remove the events of the current task,
1419 * with interrupts disabled.
1421 * We stop each event and update the event value in event->count.
1423 * This does not protect us against NMI, but disable()
1424 * sets the disabled bit in the control field of event _before_
1425 * accessing the event control register. If a NMI hits, then it will
1426 * not restart the event.
1428 void __perf_event_task_sched_out(struct task_struct
*task
,
1429 struct task_struct
*next
)
1433 for_each_task_context_nr(ctxn
)
1434 perf_event_context_sched_out(task
, ctxn
, next
);
1437 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1438 enum event_type_t event_type
)
1440 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1442 if (!cpuctx
->task_ctx
)
1445 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1448 ctx_sched_out(ctx
, cpuctx
, event_type
);
1449 cpuctx
->task_ctx
= NULL
;
1453 * Called with IRQs disabled
1455 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1456 enum event_type_t event_type
)
1458 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1462 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1463 struct perf_cpu_context
*cpuctx
)
1465 struct perf_event
*event
;
1467 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1468 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1470 if (!event_filter_match(event
))
1473 if (group_can_go_on(event
, cpuctx
, 1))
1474 group_sched_in(event
, cpuctx
, ctx
);
1477 * If this pinned group hasn't been scheduled,
1478 * put it in error state.
1480 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1481 update_group_times(event
);
1482 event
->state
= PERF_EVENT_STATE_ERROR
;
1488 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
1489 struct perf_cpu_context
*cpuctx
)
1491 struct perf_event
*event
;
1494 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1495 /* Ignore events in OFF or ERROR state */
1496 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1499 * Listen to the 'cpu' scheduling filter constraint
1502 if (!event_filter_match(event
))
1505 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
1506 if (group_sched_in(event
, cpuctx
, ctx
))
1513 ctx_sched_in(struct perf_event_context
*ctx
,
1514 struct perf_cpu_context
*cpuctx
,
1515 enum event_type_t event_type
)
1517 raw_spin_lock(&ctx
->lock
);
1519 if (likely(!ctx
->nr_events
))
1522 ctx
->timestamp
= perf_clock();
1525 * First go through the list and put on any pinned groups
1526 * in order to give them the best chance of going on.
1528 if (event_type
& EVENT_PINNED
)
1529 ctx_pinned_sched_in(ctx
, cpuctx
);
1531 /* Then walk through the lower prio flexible groups */
1532 if (event_type
& EVENT_FLEXIBLE
)
1533 ctx_flexible_sched_in(ctx
, cpuctx
);
1536 raw_spin_unlock(&ctx
->lock
);
1539 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
1540 enum event_type_t event_type
)
1542 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
1544 ctx_sched_in(ctx
, cpuctx
, event_type
);
1547 static void task_ctx_sched_in(struct perf_event_context
*ctx
,
1548 enum event_type_t event_type
)
1550 struct perf_cpu_context
*cpuctx
;
1552 cpuctx
= __get_cpu_context(ctx
);
1553 if (cpuctx
->task_ctx
== ctx
)
1556 ctx_sched_in(ctx
, cpuctx
, event_type
);
1557 cpuctx
->task_ctx
= ctx
;
1560 void perf_event_context_sched_in(struct perf_event_context
*ctx
)
1562 struct perf_cpu_context
*cpuctx
;
1564 cpuctx
= __get_cpu_context(ctx
);
1565 if (cpuctx
->task_ctx
== ctx
)
1568 perf_pmu_disable(ctx
->pmu
);
1570 * We want to keep the following priority order:
1571 * cpu pinned (that don't need to move), task pinned,
1572 * cpu flexible, task flexible.
1574 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1576 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
);
1577 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1578 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
);
1580 cpuctx
->task_ctx
= ctx
;
1583 * Since these rotations are per-cpu, we need to ensure the
1584 * cpu-context we got scheduled on is actually rotating.
1586 perf_pmu_rotate_start(ctx
->pmu
);
1587 perf_pmu_enable(ctx
->pmu
);
1591 * Called from scheduler to add the events of the current task
1592 * with interrupts disabled.
1594 * We restore the event value and then enable it.
1596 * This does not protect us against NMI, but enable()
1597 * sets the enabled bit in the control field of event _before_
1598 * accessing the event control register. If a NMI hits, then it will
1599 * keep the event running.
1601 void __perf_event_task_sched_in(struct task_struct
*task
)
1603 struct perf_event_context
*ctx
;
1606 for_each_task_context_nr(ctxn
) {
1607 ctx
= task
->perf_event_ctxp
[ctxn
];
1611 perf_event_context_sched_in(ctx
);
1615 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1617 u64 frequency
= event
->attr
.sample_freq
;
1618 u64 sec
= NSEC_PER_SEC
;
1619 u64 divisor
, dividend
;
1621 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
1623 count_fls
= fls64(count
);
1624 nsec_fls
= fls64(nsec
);
1625 frequency_fls
= fls64(frequency
);
1629 * We got @count in @nsec, with a target of sample_freq HZ
1630 * the target period becomes:
1633 * period = -------------------
1634 * @nsec * sample_freq
1639 * Reduce accuracy by one bit such that @a and @b converge
1640 * to a similar magnitude.
1642 #define REDUCE_FLS(a, b) \
1644 if (a##_fls > b##_fls) { \
1654 * Reduce accuracy until either term fits in a u64, then proceed with
1655 * the other, so that finally we can do a u64/u64 division.
1657 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
1658 REDUCE_FLS(nsec
, frequency
);
1659 REDUCE_FLS(sec
, count
);
1662 if (count_fls
+ sec_fls
> 64) {
1663 divisor
= nsec
* frequency
;
1665 while (count_fls
+ sec_fls
> 64) {
1666 REDUCE_FLS(count
, sec
);
1670 dividend
= count
* sec
;
1672 dividend
= count
* sec
;
1674 while (nsec_fls
+ frequency_fls
> 64) {
1675 REDUCE_FLS(nsec
, frequency
);
1679 divisor
= nsec
* frequency
;
1685 return div64_u64(dividend
, divisor
);
1688 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
1690 struct hw_perf_event
*hwc
= &event
->hw
;
1691 s64 period
, sample_period
;
1694 period
= perf_calculate_period(event
, nsec
, count
);
1696 delta
= (s64
)(period
- hwc
->sample_period
);
1697 delta
= (delta
+ 7) / 8; /* low pass filter */
1699 sample_period
= hwc
->sample_period
+ delta
;
1704 hwc
->sample_period
= sample_period
;
1706 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
1707 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
1708 local64_set(&hwc
->period_left
, 0);
1709 event
->pmu
->start(event
, PERF_EF_RELOAD
);
1713 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
, u64 period
)
1715 struct perf_event
*event
;
1716 struct hw_perf_event
*hwc
;
1717 u64 interrupts
, now
;
1720 raw_spin_lock(&ctx
->lock
);
1721 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
1722 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1725 if (!event_filter_match(event
))
1730 interrupts
= hwc
->interrupts
;
1731 hwc
->interrupts
= 0;
1734 * unthrottle events on the tick
1736 if (interrupts
== MAX_INTERRUPTS
) {
1737 perf_log_throttle(event
, 1);
1738 event
->pmu
->start(event
, 0);
1741 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
1744 event
->pmu
->read(event
);
1745 now
= local64_read(&event
->count
);
1746 delta
= now
- hwc
->freq_count_stamp
;
1747 hwc
->freq_count_stamp
= now
;
1750 perf_adjust_period(event
, period
, delta
);
1752 raw_spin_unlock(&ctx
->lock
);
1756 * Round-robin a context's events:
1758 static void rotate_ctx(struct perf_event_context
*ctx
)
1760 raw_spin_lock(&ctx
->lock
);
1763 * Rotate the first entry last of non-pinned groups. Rotation might be
1764 * disabled by the inheritance code.
1766 if (!ctx
->rotate_disable
)
1767 list_rotate_left(&ctx
->flexible_groups
);
1769 raw_spin_unlock(&ctx
->lock
);
1773 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
1774 * because they're strictly cpu affine and rotate_start is called with IRQs
1775 * disabled, while rotate_context is called from IRQ context.
1777 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
1779 u64 interval
= (u64
)cpuctx
->jiffies_interval
* TICK_NSEC
;
1780 struct perf_event_context
*ctx
= NULL
;
1781 int rotate
= 0, remove
= 1;
1783 if (cpuctx
->ctx
.nr_events
) {
1785 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
1789 ctx
= cpuctx
->task_ctx
;
1790 if (ctx
&& ctx
->nr_events
) {
1792 if (ctx
->nr_events
!= ctx
->nr_active
)
1796 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1797 perf_ctx_adjust_freq(&cpuctx
->ctx
, interval
);
1799 perf_ctx_adjust_freq(ctx
, interval
);
1804 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
1806 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
1808 rotate_ctx(&cpuctx
->ctx
);
1812 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
);
1814 task_ctx_sched_in(ctx
, EVENT_FLEXIBLE
);
1818 list_del_init(&cpuctx
->rotation_list
);
1820 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1823 void perf_event_task_tick(void)
1825 struct list_head
*head
= &__get_cpu_var(rotation_list
);
1826 struct perf_cpu_context
*cpuctx
, *tmp
;
1828 WARN_ON(!irqs_disabled());
1830 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
1831 if (cpuctx
->jiffies_interval
== 1 ||
1832 !(jiffies
% cpuctx
->jiffies_interval
))
1833 perf_rotate_context(cpuctx
);
1837 static int event_enable_on_exec(struct perf_event
*event
,
1838 struct perf_event_context
*ctx
)
1840 if (!event
->attr
.enable_on_exec
)
1843 event
->attr
.enable_on_exec
= 0;
1844 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1847 __perf_event_mark_enabled(event
, ctx
);
1853 * Enable all of a task's events that have been marked enable-on-exec.
1854 * This expects task == current.
1856 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
1858 struct perf_event
*event
;
1859 unsigned long flags
;
1863 local_irq_save(flags
);
1864 if (!ctx
|| !ctx
->nr_events
)
1867 task_ctx_sched_out(ctx
, EVENT_ALL
);
1869 raw_spin_lock(&ctx
->lock
);
1871 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1872 ret
= event_enable_on_exec(event
, ctx
);
1877 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1878 ret
= event_enable_on_exec(event
, ctx
);
1884 * Unclone this context if we enabled any event.
1889 raw_spin_unlock(&ctx
->lock
);
1891 perf_event_context_sched_in(ctx
);
1893 local_irq_restore(flags
);
1897 * Cross CPU call to read the hardware event
1899 static void __perf_event_read(void *info
)
1901 struct perf_event
*event
= info
;
1902 struct perf_event_context
*ctx
= event
->ctx
;
1903 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1906 * If this is a task context, we need to check whether it is
1907 * the current task context of this cpu. If not it has been
1908 * scheduled out before the smp call arrived. In that case
1909 * event->count would have been updated to a recent sample
1910 * when the event was scheduled out.
1912 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1915 raw_spin_lock(&ctx
->lock
);
1917 update_context_time(ctx
);
1918 update_event_times(event
);
1919 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
1920 event
->pmu
->read(event
);
1921 raw_spin_unlock(&ctx
->lock
);
1924 static inline u64
perf_event_count(struct perf_event
*event
)
1926 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
1929 static u64
perf_event_read(struct perf_event
*event
)
1932 * If event is enabled and currently active on a CPU, update the
1933 * value in the event structure:
1935 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1936 smp_call_function_single(event
->oncpu
,
1937 __perf_event_read
, event
, 1);
1938 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1939 struct perf_event_context
*ctx
= event
->ctx
;
1940 unsigned long flags
;
1942 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1944 * may read while context is not active
1945 * (e.g., thread is blocked), in that case
1946 * we cannot update context time
1949 update_context_time(ctx
);
1950 update_event_times(event
);
1951 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1954 return perf_event_count(event
);
1961 struct callchain_cpus_entries
{
1962 struct rcu_head rcu_head
;
1963 struct perf_callchain_entry
*cpu_entries
[0];
1966 static DEFINE_PER_CPU(int, callchain_recursion
[PERF_NR_CONTEXTS
]);
1967 static atomic_t nr_callchain_events
;
1968 static DEFINE_MUTEX(callchain_mutex
);
1969 struct callchain_cpus_entries
*callchain_cpus_entries
;
1972 __weak
void perf_callchain_kernel(struct perf_callchain_entry
*entry
,
1973 struct pt_regs
*regs
)
1977 __weak
void perf_callchain_user(struct perf_callchain_entry
*entry
,
1978 struct pt_regs
*regs
)
1982 static void release_callchain_buffers_rcu(struct rcu_head
*head
)
1984 struct callchain_cpus_entries
*entries
;
1987 entries
= container_of(head
, struct callchain_cpus_entries
, rcu_head
);
1989 for_each_possible_cpu(cpu
)
1990 kfree(entries
->cpu_entries
[cpu
]);
1995 static void release_callchain_buffers(void)
1997 struct callchain_cpus_entries
*entries
;
1999 entries
= callchain_cpus_entries
;
2000 rcu_assign_pointer(callchain_cpus_entries
, NULL
);
2001 call_rcu(&entries
->rcu_head
, release_callchain_buffers_rcu
);
2004 static int alloc_callchain_buffers(void)
2008 struct callchain_cpus_entries
*entries
;
2011 * We can't use the percpu allocation API for data that can be
2012 * accessed from NMI. Use a temporary manual per cpu allocation
2013 * until that gets sorted out.
2015 size
= offsetof(struct callchain_cpus_entries
, cpu_entries
[nr_cpu_ids
]);
2017 entries
= kzalloc(size
, GFP_KERNEL
);
2021 size
= sizeof(struct perf_callchain_entry
) * PERF_NR_CONTEXTS
;
2023 for_each_possible_cpu(cpu
) {
2024 entries
->cpu_entries
[cpu
] = kmalloc_node(size
, GFP_KERNEL
,
2026 if (!entries
->cpu_entries
[cpu
])
2030 rcu_assign_pointer(callchain_cpus_entries
, entries
);
2035 for_each_possible_cpu(cpu
)
2036 kfree(entries
->cpu_entries
[cpu
]);
2042 static int get_callchain_buffers(void)
2047 mutex_lock(&callchain_mutex
);
2049 count
= atomic_inc_return(&nr_callchain_events
);
2050 if (WARN_ON_ONCE(count
< 1)) {
2056 /* If the allocation failed, give up */
2057 if (!callchain_cpus_entries
)
2062 err
= alloc_callchain_buffers();
2064 release_callchain_buffers();
2066 mutex_unlock(&callchain_mutex
);
2071 static void put_callchain_buffers(void)
2073 if (atomic_dec_and_mutex_lock(&nr_callchain_events
, &callchain_mutex
)) {
2074 release_callchain_buffers();
2075 mutex_unlock(&callchain_mutex
);
2079 static int get_recursion_context(int *recursion
)
2087 else if (in_softirq())
2092 if (recursion
[rctx
])
2101 static inline void put_recursion_context(int *recursion
, int rctx
)
2107 static struct perf_callchain_entry
*get_callchain_entry(int *rctx
)
2110 struct callchain_cpus_entries
*entries
;
2112 *rctx
= get_recursion_context(__get_cpu_var(callchain_recursion
));
2116 entries
= rcu_dereference(callchain_cpus_entries
);
2120 cpu
= smp_processor_id();
2122 return &entries
->cpu_entries
[cpu
][*rctx
];
2126 put_callchain_entry(int rctx
)
2128 put_recursion_context(__get_cpu_var(callchain_recursion
), rctx
);
2131 static struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2134 struct perf_callchain_entry
*entry
;
2137 entry
= get_callchain_entry(&rctx
);
2146 if (!user_mode(regs
)) {
2147 perf_callchain_store(entry
, PERF_CONTEXT_KERNEL
);
2148 perf_callchain_kernel(entry
, regs
);
2150 regs
= task_pt_regs(current
);
2156 perf_callchain_store(entry
, PERF_CONTEXT_USER
);
2157 perf_callchain_user(entry
, regs
);
2161 put_callchain_entry(rctx
);
2167 * Initialize the perf_event context in a task_struct:
2169 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2171 raw_spin_lock_init(&ctx
->lock
);
2172 mutex_init(&ctx
->mutex
);
2173 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2174 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2175 INIT_LIST_HEAD(&ctx
->event_list
);
2176 atomic_set(&ctx
->refcount
, 1);
2179 static struct perf_event_context
*
2180 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2182 struct perf_event_context
*ctx
;
2184 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2188 __perf_event_init_context(ctx
);
2191 get_task_struct(task
);
2198 static struct task_struct
*
2199 find_lively_task_by_vpid(pid_t vpid
)
2201 struct task_struct
*task
;
2208 task
= find_task_by_vpid(vpid
);
2210 get_task_struct(task
);
2214 return ERR_PTR(-ESRCH
);
2216 /* Reuse ptrace permission checks for now. */
2218 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2223 put_task_struct(task
);
2224 return ERR_PTR(err
);
2228 static struct perf_event_context
*
2229 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2231 struct perf_event_context
*ctx
;
2232 struct perf_cpu_context
*cpuctx
;
2233 unsigned long flags
;
2237 /* Must be root to operate on a CPU event: */
2238 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2239 return ERR_PTR(-EACCES
);
2242 * We could be clever and allow to attach a event to an
2243 * offline CPU and activate it when the CPU comes up, but
2246 if (!cpu_online(cpu
))
2247 return ERR_PTR(-ENODEV
);
2249 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2257 ctxn
= pmu
->task_ctx_nr
;
2262 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2265 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2269 ctx
= alloc_perf_context(pmu
, task
);
2277 mutex_lock(&task
->perf_event_mutex
);
2279 * If it has already passed perf_event_exit_task().
2280 * we must see PF_EXITING, it takes this mutex too.
2282 if (task
->flags
& PF_EXITING
)
2284 else if (task
->perf_event_ctxp
[ctxn
])
2287 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2288 mutex_unlock(&task
->perf_event_mutex
);
2290 if (unlikely(err
)) {
2291 put_task_struct(task
);
2303 return ERR_PTR(err
);
2306 static void perf_event_free_filter(struct perf_event
*event
);
2308 static void free_event_rcu(struct rcu_head
*head
)
2310 struct perf_event
*event
;
2312 event
= container_of(head
, struct perf_event
, rcu_head
);
2314 put_pid_ns(event
->ns
);
2315 perf_event_free_filter(event
);
2319 static void perf_buffer_put(struct perf_buffer
*buffer
);
2321 static void free_event(struct perf_event
*event
)
2323 irq_work_sync(&event
->pending
);
2325 if (!event
->parent
) {
2326 if (event
->attach_state
& PERF_ATTACH_TASK
)
2327 jump_label_dec(&perf_task_events
);
2328 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2329 atomic_dec(&nr_mmap_events
);
2330 if (event
->attr
.comm
)
2331 atomic_dec(&nr_comm_events
);
2332 if (event
->attr
.task
)
2333 atomic_dec(&nr_task_events
);
2334 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2335 put_callchain_buffers();
2338 if (event
->buffer
) {
2339 perf_buffer_put(event
->buffer
);
2340 event
->buffer
= NULL
;
2344 event
->destroy(event
);
2347 put_ctx(event
->ctx
);
2349 call_rcu(&event
->rcu_head
, free_event_rcu
);
2352 int perf_event_release_kernel(struct perf_event
*event
)
2354 struct perf_event_context
*ctx
= event
->ctx
;
2357 * Remove from the PMU, can't get re-enabled since we got
2358 * here because the last ref went.
2360 perf_event_disable(event
);
2362 WARN_ON_ONCE(ctx
->parent_ctx
);
2364 * There are two ways this annotation is useful:
2366 * 1) there is a lock recursion from perf_event_exit_task
2367 * see the comment there.
2369 * 2) there is a lock-inversion with mmap_sem through
2370 * perf_event_read_group(), which takes faults while
2371 * holding ctx->mutex, however this is called after
2372 * the last filedesc died, so there is no possibility
2373 * to trigger the AB-BA case.
2375 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2376 raw_spin_lock_irq(&ctx
->lock
);
2377 perf_group_detach(event
);
2378 list_del_event(event
, ctx
);
2379 raw_spin_unlock_irq(&ctx
->lock
);
2380 mutex_unlock(&ctx
->mutex
);
2386 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2389 * Called when the last reference to the file is gone.
2391 static int perf_release(struct inode
*inode
, struct file
*file
)
2393 struct perf_event
*event
= file
->private_data
;
2394 struct task_struct
*owner
;
2396 file
->private_data
= NULL
;
2399 owner
= ACCESS_ONCE(event
->owner
);
2401 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2402 * !owner it means the list deletion is complete and we can indeed
2403 * free this event, otherwise we need to serialize on
2404 * owner->perf_event_mutex.
2406 smp_read_barrier_depends();
2409 * Since delayed_put_task_struct() also drops the last
2410 * task reference we can safely take a new reference
2411 * while holding the rcu_read_lock().
2413 get_task_struct(owner
);
2418 mutex_lock(&owner
->perf_event_mutex
);
2420 * We have to re-check the event->owner field, if it is cleared
2421 * we raced with perf_event_exit_task(), acquiring the mutex
2422 * ensured they're done, and we can proceed with freeing the
2426 list_del_init(&event
->owner_entry
);
2427 mutex_unlock(&owner
->perf_event_mutex
);
2428 put_task_struct(owner
);
2431 return perf_event_release_kernel(event
);
2434 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
2436 struct perf_event
*child
;
2442 mutex_lock(&event
->child_mutex
);
2443 total
+= perf_event_read(event
);
2444 *enabled
+= event
->total_time_enabled
+
2445 atomic64_read(&event
->child_total_time_enabled
);
2446 *running
+= event
->total_time_running
+
2447 atomic64_read(&event
->child_total_time_running
);
2449 list_for_each_entry(child
, &event
->child_list
, child_list
) {
2450 total
+= perf_event_read(child
);
2451 *enabled
+= child
->total_time_enabled
;
2452 *running
+= child
->total_time_running
;
2454 mutex_unlock(&event
->child_mutex
);
2458 EXPORT_SYMBOL_GPL(perf_event_read_value
);
2460 static int perf_event_read_group(struct perf_event
*event
,
2461 u64 read_format
, char __user
*buf
)
2463 struct perf_event
*leader
= event
->group_leader
, *sub
;
2464 int n
= 0, size
= 0, ret
= -EFAULT
;
2465 struct perf_event_context
*ctx
= leader
->ctx
;
2467 u64 count
, enabled
, running
;
2469 mutex_lock(&ctx
->mutex
);
2470 count
= perf_event_read_value(leader
, &enabled
, &running
);
2472 values
[n
++] = 1 + leader
->nr_siblings
;
2473 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2474 values
[n
++] = enabled
;
2475 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2476 values
[n
++] = running
;
2477 values
[n
++] = count
;
2478 if (read_format
& PERF_FORMAT_ID
)
2479 values
[n
++] = primary_event_id(leader
);
2481 size
= n
* sizeof(u64
);
2483 if (copy_to_user(buf
, values
, size
))
2488 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
2491 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
2492 if (read_format
& PERF_FORMAT_ID
)
2493 values
[n
++] = primary_event_id(sub
);
2495 size
= n
* sizeof(u64
);
2497 if (copy_to_user(buf
+ ret
, values
, size
)) {
2505 mutex_unlock(&ctx
->mutex
);
2510 static int perf_event_read_one(struct perf_event
*event
,
2511 u64 read_format
, char __user
*buf
)
2513 u64 enabled
, running
;
2517 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
2518 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2519 values
[n
++] = enabled
;
2520 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2521 values
[n
++] = running
;
2522 if (read_format
& PERF_FORMAT_ID
)
2523 values
[n
++] = primary_event_id(event
);
2525 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2528 return n
* sizeof(u64
);
2532 * Read the performance event - simple non blocking version for now
2535 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2537 u64 read_format
= event
->attr
.read_format
;
2541 * Return end-of-file for a read on a event that is in
2542 * error state (i.e. because it was pinned but it couldn't be
2543 * scheduled on to the CPU at some point).
2545 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2548 if (count
< event
->read_size
)
2551 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2552 if (read_format
& PERF_FORMAT_GROUP
)
2553 ret
= perf_event_read_group(event
, read_format
, buf
);
2555 ret
= perf_event_read_one(event
, read_format
, buf
);
2561 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2563 struct perf_event
*event
= file
->private_data
;
2565 return perf_read_hw(event
, buf
, count
);
2568 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2570 struct perf_event
*event
= file
->private_data
;
2571 struct perf_buffer
*buffer
;
2572 unsigned int events
= POLL_HUP
;
2575 buffer
= rcu_dereference(event
->buffer
);
2577 events
= atomic_xchg(&buffer
->poll
, 0);
2580 poll_wait(file
, &event
->waitq
, wait
);
2585 static void perf_event_reset(struct perf_event
*event
)
2587 (void)perf_event_read(event
);
2588 local64_set(&event
->count
, 0);
2589 perf_event_update_userpage(event
);
2593 * Holding the top-level event's child_mutex means that any
2594 * descendant process that has inherited this event will block
2595 * in sync_child_event if it goes to exit, thus satisfying the
2596 * task existence requirements of perf_event_enable/disable.
2598 static void perf_event_for_each_child(struct perf_event
*event
,
2599 void (*func
)(struct perf_event
*))
2601 struct perf_event
*child
;
2603 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2604 mutex_lock(&event
->child_mutex
);
2606 list_for_each_entry(child
, &event
->child_list
, child_list
)
2608 mutex_unlock(&event
->child_mutex
);
2611 static void perf_event_for_each(struct perf_event
*event
,
2612 void (*func
)(struct perf_event
*))
2614 struct perf_event_context
*ctx
= event
->ctx
;
2615 struct perf_event
*sibling
;
2617 WARN_ON_ONCE(ctx
->parent_ctx
);
2618 mutex_lock(&ctx
->mutex
);
2619 event
= event
->group_leader
;
2621 perf_event_for_each_child(event
, func
);
2623 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
2624 perf_event_for_each_child(event
, func
);
2625 mutex_unlock(&ctx
->mutex
);
2628 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
2630 struct perf_event_context
*ctx
= event
->ctx
;
2634 if (!is_sampling_event(event
))
2637 if (copy_from_user(&value
, arg
, sizeof(value
)))
2643 raw_spin_lock_irq(&ctx
->lock
);
2644 if (event
->attr
.freq
) {
2645 if (value
> sysctl_perf_event_sample_rate
) {
2650 event
->attr
.sample_freq
= value
;
2652 event
->attr
.sample_period
= value
;
2653 event
->hw
.sample_period
= value
;
2656 raw_spin_unlock_irq(&ctx
->lock
);
2661 static const struct file_operations perf_fops
;
2663 static struct perf_event
*perf_fget_light(int fd
, int *fput_needed
)
2667 file
= fget_light(fd
, fput_needed
);
2669 return ERR_PTR(-EBADF
);
2671 if (file
->f_op
!= &perf_fops
) {
2672 fput_light(file
, *fput_needed
);
2674 return ERR_PTR(-EBADF
);
2677 return file
->private_data
;
2680 static int perf_event_set_output(struct perf_event
*event
,
2681 struct perf_event
*output_event
);
2682 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
2684 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
2686 struct perf_event
*event
= file
->private_data
;
2687 void (*func
)(struct perf_event
*);
2691 case PERF_EVENT_IOC_ENABLE
:
2692 func
= perf_event_enable
;
2694 case PERF_EVENT_IOC_DISABLE
:
2695 func
= perf_event_disable
;
2697 case PERF_EVENT_IOC_RESET
:
2698 func
= perf_event_reset
;
2701 case PERF_EVENT_IOC_REFRESH
:
2702 return perf_event_refresh(event
, arg
);
2704 case PERF_EVENT_IOC_PERIOD
:
2705 return perf_event_period(event
, (u64 __user
*)arg
);
2707 case PERF_EVENT_IOC_SET_OUTPUT
:
2709 struct perf_event
*output_event
= NULL
;
2710 int fput_needed
= 0;
2714 output_event
= perf_fget_light(arg
, &fput_needed
);
2715 if (IS_ERR(output_event
))
2716 return PTR_ERR(output_event
);
2719 ret
= perf_event_set_output(event
, output_event
);
2721 fput_light(output_event
->filp
, fput_needed
);
2726 case PERF_EVENT_IOC_SET_FILTER
:
2727 return perf_event_set_filter(event
, (void __user
*)arg
);
2733 if (flags
& PERF_IOC_FLAG_GROUP
)
2734 perf_event_for_each(event
, func
);
2736 perf_event_for_each_child(event
, func
);
2741 int perf_event_task_enable(void)
2743 struct perf_event
*event
;
2745 mutex_lock(¤t
->perf_event_mutex
);
2746 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2747 perf_event_for_each_child(event
, perf_event_enable
);
2748 mutex_unlock(¤t
->perf_event_mutex
);
2753 int perf_event_task_disable(void)
2755 struct perf_event
*event
;
2757 mutex_lock(¤t
->perf_event_mutex
);
2758 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
2759 perf_event_for_each_child(event
, perf_event_disable
);
2760 mutex_unlock(¤t
->perf_event_mutex
);
2765 #ifndef PERF_EVENT_INDEX_OFFSET
2766 # define PERF_EVENT_INDEX_OFFSET 0
2769 static int perf_event_index(struct perf_event
*event
)
2771 if (event
->hw
.state
& PERF_HES_STOPPED
)
2774 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2777 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
2781 * Callers need to ensure there can be no nesting of this function, otherwise
2782 * the seqlock logic goes bad. We can not serialize this because the arch
2783 * code calls this from NMI context.
2785 void perf_event_update_userpage(struct perf_event
*event
)
2787 struct perf_event_mmap_page
*userpg
;
2788 struct perf_buffer
*buffer
;
2791 buffer
= rcu_dereference(event
->buffer
);
2795 userpg
= buffer
->user_page
;
2798 * Disable preemption so as to not let the corresponding user-space
2799 * spin too long if we get preempted.
2804 userpg
->index
= perf_event_index(event
);
2805 userpg
->offset
= perf_event_count(event
);
2806 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2807 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
2809 userpg
->time_enabled
= event
->total_time_enabled
+
2810 atomic64_read(&event
->child_total_time_enabled
);
2812 userpg
->time_running
= event
->total_time_running
+
2813 atomic64_read(&event
->child_total_time_running
);
2822 static unsigned long perf_data_size(struct perf_buffer
*buffer
);
2825 perf_buffer_init(struct perf_buffer
*buffer
, long watermark
, int flags
)
2827 long max_size
= perf_data_size(buffer
);
2830 buffer
->watermark
= min(max_size
, watermark
);
2832 if (!buffer
->watermark
)
2833 buffer
->watermark
= max_size
/ 2;
2835 if (flags
& PERF_BUFFER_WRITABLE
)
2836 buffer
->writable
= 1;
2838 atomic_set(&buffer
->refcount
, 1);
2841 #ifndef CONFIG_PERF_USE_VMALLOC
2844 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
2847 static struct page
*
2848 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
2850 if (pgoff
> buffer
->nr_pages
)
2854 return virt_to_page(buffer
->user_page
);
2856 return virt_to_page(buffer
->data_pages
[pgoff
- 1]);
2859 static void *perf_mmap_alloc_page(int cpu
)
2864 node
= (cpu
== -1) ? cpu
: cpu_to_node(cpu
);
2865 page
= alloc_pages_node(node
, GFP_KERNEL
| __GFP_ZERO
, 0);
2869 return page_address(page
);
2872 static struct perf_buffer
*
2873 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
2875 struct perf_buffer
*buffer
;
2879 size
= sizeof(struct perf_buffer
);
2880 size
+= nr_pages
* sizeof(void *);
2882 buffer
= kzalloc(size
, GFP_KERNEL
);
2886 buffer
->user_page
= perf_mmap_alloc_page(cpu
);
2887 if (!buffer
->user_page
)
2888 goto fail_user_page
;
2890 for (i
= 0; i
< nr_pages
; i
++) {
2891 buffer
->data_pages
[i
] = perf_mmap_alloc_page(cpu
);
2892 if (!buffer
->data_pages
[i
])
2893 goto fail_data_pages
;
2896 buffer
->nr_pages
= nr_pages
;
2898 perf_buffer_init(buffer
, watermark
, flags
);
2903 for (i
--; i
>= 0; i
--)
2904 free_page((unsigned long)buffer
->data_pages
[i
]);
2906 free_page((unsigned long)buffer
->user_page
);
2915 static void perf_mmap_free_page(unsigned long addr
)
2917 struct page
*page
= virt_to_page((void *)addr
);
2919 page
->mapping
= NULL
;
2923 static void perf_buffer_free(struct perf_buffer
*buffer
)
2927 perf_mmap_free_page((unsigned long)buffer
->user_page
);
2928 for (i
= 0; i
< buffer
->nr_pages
; i
++)
2929 perf_mmap_free_page((unsigned long)buffer
->data_pages
[i
]);
2933 static inline int page_order(struct perf_buffer
*buffer
)
2941 * Back perf_mmap() with vmalloc memory.
2943 * Required for architectures that have d-cache aliasing issues.
2946 static inline int page_order(struct perf_buffer
*buffer
)
2948 return buffer
->page_order
;
2951 static struct page
*
2952 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
2954 if (pgoff
> (1UL << page_order(buffer
)))
2957 return vmalloc_to_page((void *)buffer
->user_page
+ pgoff
* PAGE_SIZE
);
2960 static void perf_mmap_unmark_page(void *addr
)
2962 struct page
*page
= vmalloc_to_page(addr
);
2964 page
->mapping
= NULL
;
2967 static void perf_buffer_free_work(struct work_struct
*work
)
2969 struct perf_buffer
*buffer
;
2973 buffer
= container_of(work
, struct perf_buffer
, work
);
2974 nr
= 1 << page_order(buffer
);
2976 base
= buffer
->user_page
;
2977 for (i
= 0; i
< nr
+ 1; i
++)
2978 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
2984 static void perf_buffer_free(struct perf_buffer
*buffer
)
2986 schedule_work(&buffer
->work
);
2989 static struct perf_buffer
*
2990 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
2992 struct perf_buffer
*buffer
;
2996 size
= sizeof(struct perf_buffer
);
2997 size
+= sizeof(void *);
2999 buffer
= kzalloc(size
, GFP_KERNEL
);
3003 INIT_WORK(&buffer
->work
, perf_buffer_free_work
);
3005 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
3009 buffer
->user_page
= all_buf
;
3010 buffer
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
3011 buffer
->page_order
= ilog2(nr_pages
);
3012 buffer
->nr_pages
= 1;
3014 perf_buffer_init(buffer
, watermark
, flags
);
3027 static unsigned long perf_data_size(struct perf_buffer
*buffer
)
3029 return buffer
->nr_pages
<< (PAGE_SHIFT
+ page_order(buffer
));
3032 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3034 struct perf_event
*event
= vma
->vm_file
->private_data
;
3035 struct perf_buffer
*buffer
;
3036 int ret
= VM_FAULT_SIGBUS
;
3038 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3039 if (vmf
->pgoff
== 0)
3045 buffer
= rcu_dereference(event
->buffer
);
3049 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3052 vmf
->page
= perf_mmap_to_page(buffer
, vmf
->pgoff
);
3056 get_page(vmf
->page
);
3057 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3058 vmf
->page
->index
= vmf
->pgoff
;
3067 static void perf_buffer_free_rcu(struct rcu_head
*rcu_head
)
3069 struct perf_buffer
*buffer
;
3071 buffer
= container_of(rcu_head
, struct perf_buffer
, rcu_head
);
3072 perf_buffer_free(buffer
);
3075 static struct perf_buffer
*perf_buffer_get(struct perf_event
*event
)
3077 struct perf_buffer
*buffer
;
3080 buffer
= rcu_dereference(event
->buffer
);
3082 if (!atomic_inc_not_zero(&buffer
->refcount
))
3090 static void perf_buffer_put(struct perf_buffer
*buffer
)
3092 if (!atomic_dec_and_test(&buffer
->refcount
))
3095 call_rcu(&buffer
->rcu_head
, perf_buffer_free_rcu
);
3098 static void perf_mmap_open(struct vm_area_struct
*vma
)
3100 struct perf_event
*event
= vma
->vm_file
->private_data
;
3102 atomic_inc(&event
->mmap_count
);
3105 static void perf_mmap_close(struct vm_area_struct
*vma
)
3107 struct perf_event
*event
= vma
->vm_file
->private_data
;
3109 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3110 unsigned long size
= perf_data_size(event
->buffer
);
3111 struct user_struct
*user
= event
->mmap_user
;
3112 struct perf_buffer
*buffer
= event
->buffer
;
3114 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3115 vma
->vm_mm
->locked_vm
-= event
->mmap_locked
;
3116 rcu_assign_pointer(event
->buffer
, NULL
);
3117 mutex_unlock(&event
->mmap_mutex
);
3119 perf_buffer_put(buffer
);
3124 static const struct vm_operations_struct perf_mmap_vmops
= {
3125 .open
= perf_mmap_open
,
3126 .close
= perf_mmap_close
,
3127 .fault
= perf_mmap_fault
,
3128 .page_mkwrite
= perf_mmap_fault
,
3131 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3133 struct perf_event
*event
= file
->private_data
;
3134 unsigned long user_locked
, user_lock_limit
;
3135 struct user_struct
*user
= current_user();
3136 unsigned long locked
, lock_limit
;
3137 struct perf_buffer
*buffer
;
3138 unsigned long vma_size
;
3139 unsigned long nr_pages
;
3140 long user_extra
, extra
;
3141 int ret
= 0, flags
= 0;
3144 * Don't allow mmap() of inherited per-task counters. This would
3145 * create a performance issue due to all children writing to the
3148 if (event
->cpu
== -1 && event
->attr
.inherit
)
3151 if (!(vma
->vm_flags
& VM_SHARED
))
3154 vma_size
= vma
->vm_end
- vma
->vm_start
;
3155 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3158 * If we have buffer pages ensure they're a power-of-two number, so we
3159 * can do bitmasks instead of modulo.
3161 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3164 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3167 if (vma
->vm_pgoff
!= 0)
3170 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3171 mutex_lock(&event
->mmap_mutex
);
3172 if (event
->buffer
) {
3173 if (event
->buffer
->nr_pages
== nr_pages
)
3174 atomic_inc(&event
->buffer
->refcount
);
3180 user_extra
= nr_pages
+ 1;
3181 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3184 * Increase the limit linearly with more CPUs:
3186 user_lock_limit
*= num_online_cpus();
3188 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3191 if (user_locked
> user_lock_limit
)
3192 extra
= user_locked
- user_lock_limit
;
3194 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3195 lock_limit
>>= PAGE_SHIFT
;
3196 locked
= vma
->vm_mm
->locked_vm
+ extra
;
3198 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3199 !capable(CAP_IPC_LOCK
)) {
3204 WARN_ON(event
->buffer
);
3206 if (vma
->vm_flags
& VM_WRITE
)
3207 flags
|= PERF_BUFFER_WRITABLE
;
3209 buffer
= perf_buffer_alloc(nr_pages
, event
->attr
.wakeup_watermark
,
3215 rcu_assign_pointer(event
->buffer
, buffer
);
3217 atomic_long_add(user_extra
, &user
->locked_vm
);
3218 event
->mmap_locked
= extra
;
3219 event
->mmap_user
= get_current_user();
3220 vma
->vm_mm
->locked_vm
+= event
->mmap_locked
;
3224 atomic_inc(&event
->mmap_count
);
3225 mutex_unlock(&event
->mmap_mutex
);
3227 vma
->vm_flags
|= VM_RESERVED
;
3228 vma
->vm_ops
= &perf_mmap_vmops
;
3233 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3235 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3236 struct perf_event
*event
= filp
->private_data
;
3239 mutex_lock(&inode
->i_mutex
);
3240 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3241 mutex_unlock(&inode
->i_mutex
);
3249 static const struct file_operations perf_fops
= {
3250 .llseek
= no_llseek
,
3251 .release
= perf_release
,
3254 .unlocked_ioctl
= perf_ioctl
,
3255 .compat_ioctl
= perf_ioctl
,
3257 .fasync
= perf_fasync
,
3263 * If there's data, ensure we set the poll() state and publish everything
3264 * to user-space before waking everybody up.
3267 void perf_event_wakeup(struct perf_event
*event
)
3269 wake_up_all(&event
->waitq
);
3271 if (event
->pending_kill
) {
3272 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3273 event
->pending_kill
= 0;
3277 static void perf_pending_event(struct irq_work
*entry
)
3279 struct perf_event
*event
= container_of(entry
,
3280 struct perf_event
, pending
);
3282 if (event
->pending_disable
) {
3283 event
->pending_disable
= 0;
3284 __perf_event_disable(event
);
3287 if (event
->pending_wakeup
) {
3288 event
->pending_wakeup
= 0;
3289 perf_event_wakeup(event
);
3294 * We assume there is only KVM supporting the callbacks.
3295 * Later on, we might change it to a list if there is
3296 * another virtualization implementation supporting the callbacks.
3298 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3300 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3302 perf_guest_cbs
= cbs
;
3305 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3307 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3309 perf_guest_cbs
= NULL
;
3312 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3317 static bool perf_output_space(struct perf_buffer
*buffer
, unsigned long tail
,
3318 unsigned long offset
, unsigned long head
)
3322 if (!buffer
->writable
)
3325 mask
= perf_data_size(buffer
) - 1;
3327 offset
= (offset
- tail
) & mask
;
3328 head
= (head
- tail
) & mask
;
3330 if ((int)(head
- offset
) < 0)
3336 static void perf_output_wakeup(struct perf_output_handle
*handle
)
3338 atomic_set(&handle
->buffer
->poll
, POLL_IN
);
3341 handle
->event
->pending_wakeup
= 1;
3342 irq_work_queue(&handle
->event
->pending
);
3344 perf_event_wakeup(handle
->event
);
3348 * We need to ensure a later event_id doesn't publish a head when a former
3349 * event isn't done writing. However since we need to deal with NMIs we
3350 * cannot fully serialize things.
3352 * We only publish the head (and generate a wakeup) when the outer-most
3355 static void perf_output_get_handle(struct perf_output_handle
*handle
)
3357 struct perf_buffer
*buffer
= handle
->buffer
;
3360 local_inc(&buffer
->nest
);
3361 handle
->wakeup
= local_read(&buffer
->wakeup
);
3364 static void perf_output_put_handle(struct perf_output_handle
*handle
)
3366 struct perf_buffer
*buffer
= handle
->buffer
;
3370 head
= local_read(&buffer
->head
);
3373 * IRQ/NMI can happen here, which means we can miss a head update.
3376 if (!local_dec_and_test(&buffer
->nest
))
3380 * Publish the known good head. Rely on the full barrier implied
3381 * by atomic_dec_and_test() order the buffer->head read and this
3384 buffer
->user_page
->data_head
= head
;
3387 * Now check if we missed an update, rely on the (compiler)
3388 * barrier in atomic_dec_and_test() to re-read buffer->head.
3390 if (unlikely(head
!= local_read(&buffer
->head
))) {
3391 local_inc(&buffer
->nest
);
3395 if (handle
->wakeup
!= local_read(&buffer
->wakeup
))
3396 perf_output_wakeup(handle
);
3402 __always_inline
void perf_output_copy(struct perf_output_handle
*handle
,
3403 const void *buf
, unsigned int len
)
3406 unsigned long size
= min_t(unsigned long, handle
->size
, len
);
3408 memcpy(handle
->addr
, buf
, size
);
3411 handle
->addr
+= size
;
3413 handle
->size
-= size
;
3414 if (!handle
->size
) {
3415 struct perf_buffer
*buffer
= handle
->buffer
;
3418 handle
->page
&= buffer
->nr_pages
- 1;
3419 handle
->addr
= buffer
->data_pages
[handle
->page
];
3420 handle
->size
= PAGE_SIZE
<< page_order(buffer
);
3425 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3426 struct perf_sample_data
*data
,
3427 struct perf_event
*event
)
3429 u64 sample_type
= event
->attr
.sample_type
;
3431 data
->type
= sample_type
;
3432 header
->size
+= event
->id_header_size
;
3434 if (sample_type
& PERF_SAMPLE_TID
) {
3435 /* namespace issues */
3436 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3437 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3440 if (sample_type
& PERF_SAMPLE_TIME
)
3441 data
->time
= perf_clock();
3443 if (sample_type
& PERF_SAMPLE_ID
)
3444 data
->id
= primary_event_id(event
);
3446 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3447 data
->stream_id
= event
->id
;
3449 if (sample_type
& PERF_SAMPLE_CPU
) {
3450 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3451 data
->cpu_entry
.reserved
= 0;
3455 static void perf_event_header__init_id(struct perf_event_header
*header
,
3456 struct perf_sample_data
*data
,
3457 struct perf_event
*event
)
3459 if (event
->attr
.sample_id_all
)
3460 __perf_event_header__init_id(header
, data
, event
);
3463 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
3464 struct perf_sample_data
*data
)
3466 u64 sample_type
= data
->type
;
3468 if (sample_type
& PERF_SAMPLE_TID
)
3469 perf_output_put(handle
, data
->tid_entry
);
3471 if (sample_type
& PERF_SAMPLE_TIME
)
3472 perf_output_put(handle
, data
->time
);
3474 if (sample_type
& PERF_SAMPLE_ID
)
3475 perf_output_put(handle
, data
->id
);
3477 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3478 perf_output_put(handle
, data
->stream_id
);
3480 if (sample_type
& PERF_SAMPLE_CPU
)
3481 perf_output_put(handle
, data
->cpu_entry
);
3484 static void perf_event__output_id_sample(struct perf_event
*event
,
3485 struct perf_output_handle
*handle
,
3486 struct perf_sample_data
*sample
)
3488 if (event
->attr
.sample_id_all
)
3489 __perf_event__output_id_sample(handle
, sample
);
3492 int perf_output_begin(struct perf_output_handle
*handle
,
3493 struct perf_event
*event
, unsigned int size
,
3494 int nmi
, int sample
)
3496 struct perf_buffer
*buffer
;
3497 unsigned long tail
, offset
, head
;
3499 struct perf_sample_data sample_data
;
3501 struct perf_event_header header
;
3508 * For inherited events we send all the output towards the parent.
3511 event
= event
->parent
;
3513 buffer
= rcu_dereference(event
->buffer
);
3517 handle
->buffer
= buffer
;
3518 handle
->event
= event
;
3520 handle
->sample
= sample
;
3522 if (!buffer
->nr_pages
)
3525 have_lost
= local_read(&buffer
->lost
);
3527 lost_event
.header
.size
= sizeof(lost_event
);
3528 perf_event_header__init_id(&lost_event
.header
, &sample_data
,
3530 size
+= lost_event
.header
.size
;
3533 perf_output_get_handle(handle
);
3537 * Userspace could choose to issue a mb() before updating the
3538 * tail pointer. So that all reads will be completed before the
3541 tail
= ACCESS_ONCE(buffer
->user_page
->data_tail
);
3543 offset
= head
= local_read(&buffer
->head
);
3545 if (unlikely(!perf_output_space(buffer
, tail
, offset
, head
)))
3547 } while (local_cmpxchg(&buffer
->head
, offset
, head
) != offset
);
3549 if (head
- local_read(&buffer
->wakeup
) > buffer
->watermark
)
3550 local_add(buffer
->watermark
, &buffer
->wakeup
);
3552 handle
->page
= offset
>> (PAGE_SHIFT
+ page_order(buffer
));
3553 handle
->page
&= buffer
->nr_pages
- 1;
3554 handle
->size
= offset
& ((PAGE_SIZE
<< page_order(buffer
)) - 1);
3555 handle
->addr
= buffer
->data_pages
[handle
->page
];
3556 handle
->addr
+= handle
->size
;
3557 handle
->size
= (PAGE_SIZE
<< page_order(buffer
)) - handle
->size
;
3560 lost_event
.header
.type
= PERF_RECORD_LOST
;
3561 lost_event
.header
.misc
= 0;
3562 lost_event
.id
= event
->id
;
3563 lost_event
.lost
= local_xchg(&buffer
->lost
, 0);
3565 perf_output_put(handle
, lost_event
);
3566 perf_event__output_id_sample(event
, handle
, &sample_data
);
3572 local_inc(&buffer
->lost
);
3573 perf_output_put_handle(handle
);
3580 void perf_output_end(struct perf_output_handle
*handle
)
3582 struct perf_event
*event
= handle
->event
;
3583 struct perf_buffer
*buffer
= handle
->buffer
;
3585 int wakeup_events
= event
->attr
.wakeup_events
;
3587 if (handle
->sample
&& wakeup_events
) {
3588 int events
= local_inc_return(&buffer
->events
);
3589 if (events
>= wakeup_events
) {
3590 local_sub(wakeup_events
, &buffer
->events
);
3591 local_inc(&buffer
->wakeup
);
3595 perf_output_put_handle(handle
);
3599 static void perf_output_read_one(struct perf_output_handle
*handle
,
3600 struct perf_event
*event
,
3601 u64 enabled
, u64 running
)
3603 u64 read_format
= event
->attr
.read_format
;
3607 values
[n
++] = perf_event_count(event
);
3608 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3609 values
[n
++] = enabled
+
3610 atomic64_read(&event
->child_total_time_enabled
);
3612 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3613 values
[n
++] = running
+
3614 atomic64_read(&event
->child_total_time_running
);
3616 if (read_format
& PERF_FORMAT_ID
)
3617 values
[n
++] = primary_event_id(event
);
3619 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3623 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3625 static void perf_output_read_group(struct perf_output_handle
*handle
,
3626 struct perf_event
*event
,
3627 u64 enabled
, u64 running
)
3629 struct perf_event
*leader
= event
->group_leader
, *sub
;
3630 u64 read_format
= event
->attr
.read_format
;
3634 values
[n
++] = 1 + leader
->nr_siblings
;
3636 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3637 values
[n
++] = enabled
;
3639 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3640 values
[n
++] = running
;
3642 if (leader
!= event
)
3643 leader
->pmu
->read(leader
);
3645 values
[n
++] = perf_event_count(leader
);
3646 if (read_format
& PERF_FORMAT_ID
)
3647 values
[n
++] = primary_event_id(leader
);
3649 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3651 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3655 sub
->pmu
->read(sub
);
3657 values
[n
++] = perf_event_count(sub
);
3658 if (read_format
& PERF_FORMAT_ID
)
3659 values
[n
++] = primary_event_id(sub
);
3661 perf_output_copy(handle
, values
, n
* sizeof(u64
));
3665 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
3666 PERF_FORMAT_TOTAL_TIME_RUNNING)
3668 static void perf_output_read(struct perf_output_handle
*handle
,
3669 struct perf_event
*event
)
3671 u64 enabled
= 0, running
= 0, now
, ctx_time
;
3672 u64 read_format
= event
->attr
.read_format
;
3675 * compute total_time_enabled, total_time_running
3676 * based on snapshot values taken when the event
3677 * was last scheduled in.
3679 * we cannot simply called update_context_time()
3680 * because of locking issue as we are called in
3683 if (read_format
& PERF_FORMAT_TOTAL_TIMES
) {
3685 ctx_time
= event
->shadow_ctx_time
+ now
;
3686 enabled
= ctx_time
- event
->tstamp_enabled
;
3687 running
= ctx_time
- event
->tstamp_running
;
3690 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3691 perf_output_read_group(handle
, event
, enabled
, running
);
3693 perf_output_read_one(handle
, event
, enabled
, running
);
3696 void perf_output_sample(struct perf_output_handle
*handle
,
3697 struct perf_event_header
*header
,
3698 struct perf_sample_data
*data
,
3699 struct perf_event
*event
)
3701 u64 sample_type
= data
->type
;
3703 perf_output_put(handle
, *header
);
3705 if (sample_type
& PERF_SAMPLE_IP
)
3706 perf_output_put(handle
, data
->ip
);
3708 if (sample_type
& PERF_SAMPLE_TID
)
3709 perf_output_put(handle
, data
->tid_entry
);
3711 if (sample_type
& PERF_SAMPLE_TIME
)
3712 perf_output_put(handle
, data
->time
);
3714 if (sample_type
& PERF_SAMPLE_ADDR
)
3715 perf_output_put(handle
, data
->addr
);
3717 if (sample_type
& PERF_SAMPLE_ID
)
3718 perf_output_put(handle
, data
->id
);
3720 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3721 perf_output_put(handle
, data
->stream_id
);
3723 if (sample_type
& PERF_SAMPLE_CPU
)
3724 perf_output_put(handle
, data
->cpu_entry
);
3726 if (sample_type
& PERF_SAMPLE_PERIOD
)
3727 perf_output_put(handle
, data
->period
);
3729 if (sample_type
& PERF_SAMPLE_READ
)
3730 perf_output_read(handle
, event
);
3732 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3733 if (data
->callchain
) {
3736 if (data
->callchain
)
3737 size
+= data
->callchain
->nr
;
3739 size
*= sizeof(u64
);
3741 perf_output_copy(handle
, data
->callchain
, size
);
3744 perf_output_put(handle
, nr
);
3748 if (sample_type
& PERF_SAMPLE_RAW
) {
3750 perf_output_put(handle
, data
->raw
->size
);
3751 perf_output_copy(handle
, data
->raw
->data
,
3758 .size
= sizeof(u32
),
3761 perf_output_put(handle
, raw
);
3766 void perf_prepare_sample(struct perf_event_header
*header
,
3767 struct perf_sample_data
*data
,
3768 struct perf_event
*event
,
3769 struct pt_regs
*regs
)
3771 u64 sample_type
= event
->attr
.sample_type
;
3773 header
->type
= PERF_RECORD_SAMPLE
;
3774 header
->size
= sizeof(*header
) + event
->header_size
;
3777 header
->misc
|= perf_misc_flags(regs
);
3779 __perf_event_header__init_id(header
, data
, event
);
3781 if (sample_type
& PERF_SAMPLE_IP
)
3782 data
->ip
= perf_instruction_pointer(regs
);
3784 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3787 data
->callchain
= perf_callchain(regs
);
3789 if (data
->callchain
)
3790 size
+= data
->callchain
->nr
;
3792 header
->size
+= size
* sizeof(u64
);
3795 if (sample_type
& PERF_SAMPLE_RAW
) {
3796 int size
= sizeof(u32
);
3799 size
+= data
->raw
->size
;
3801 size
+= sizeof(u32
);
3803 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3804 header
->size
+= size
;
3808 static void perf_event_output(struct perf_event
*event
, int nmi
,
3809 struct perf_sample_data
*data
,
3810 struct pt_regs
*regs
)
3812 struct perf_output_handle handle
;
3813 struct perf_event_header header
;
3815 /* protect the callchain buffers */
3818 perf_prepare_sample(&header
, data
, event
, regs
);
3820 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
3823 perf_output_sample(&handle
, &header
, data
, event
);
3825 perf_output_end(&handle
);
3835 struct perf_read_event
{
3836 struct perf_event_header header
;
3843 perf_event_read_event(struct perf_event
*event
,
3844 struct task_struct
*task
)
3846 struct perf_output_handle handle
;
3847 struct perf_sample_data sample
;
3848 struct perf_read_event read_event
= {
3850 .type
= PERF_RECORD_READ
,
3852 .size
= sizeof(read_event
) + event
->read_size
,
3854 .pid
= perf_event_pid(event
, task
),
3855 .tid
= perf_event_tid(event
, task
),
3859 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
3860 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
3864 perf_output_put(&handle
, read_event
);
3865 perf_output_read(&handle
, event
);
3866 perf_event__output_id_sample(event
, &handle
, &sample
);
3868 perf_output_end(&handle
);
3872 * task tracking -- fork/exit
3874 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
3877 struct perf_task_event
{
3878 struct task_struct
*task
;
3879 struct perf_event_context
*task_ctx
;
3882 struct perf_event_header header
;
3892 static void perf_event_task_output(struct perf_event
*event
,
3893 struct perf_task_event
*task_event
)
3895 struct perf_output_handle handle
;
3896 struct perf_sample_data sample
;
3897 struct task_struct
*task
= task_event
->task
;
3898 int ret
, size
= task_event
->event_id
.header
.size
;
3900 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
3902 ret
= perf_output_begin(&handle
, event
,
3903 task_event
->event_id
.header
.size
, 0, 0);
3907 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
3908 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
3910 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
3911 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
3913 perf_output_put(&handle
, task_event
->event_id
);
3915 perf_event__output_id_sample(event
, &handle
, &sample
);
3917 perf_output_end(&handle
);
3919 task_event
->event_id
.header
.size
= size
;
3922 static int perf_event_task_match(struct perf_event
*event
)
3924 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
3927 if (!event_filter_match(event
))
3930 if (event
->attr
.comm
|| event
->attr
.mmap
||
3931 event
->attr
.mmap_data
|| event
->attr
.task
)
3937 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
3938 struct perf_task_event
*task_event
)
3940 struct perf_event
*event
;
3942 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3943 if (perf_event_task_match(event
))
3944 perf_event_task_output(event
, task_event
);
3948 static void perf_event_task_event(struct perf_task_event
*task_event
)
3950 struct perf_cpu_context
*cpuctx
;
3951 struct perf_event_context
*ctx
;
3956 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
3957 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
3958 if (cpuctx
->active_pmu
!= pmu
)
3960 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
3962 ctx
= task_event
->task_ctx
;
3964 ctxn
= pmu
->task_ctx_nr
;
3967 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
3970 perf_event_task_ctx(ctx
, task_event
);
3972 put_cpu_ptr(pmu
->pmu_cpu_context
);
3977 static void perf_event_task(struct task_struct
*task
,
3978 struct perf_event_context
*task_ctx
,
3981 struct perf_task_event task_event
;
3983 if (!atomic_read(&nr_comm_events
) &&
3984 !atomic_read(&nr_mmap_events
) &&
3985 !atomic_read(&nr_task_events
))
3988 task_event
= (struct perf_task_event
){
3990 .task_ctx
= task_ctx
,
3993 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
3995 .size
= sizeof(task_event
.event_id
),
4001 .time
= perf_clock(),
4005 perf_event_task_event(&task_event
);
4008 void perf_event_fork(struct task_struct
*task
)
4010 perf_event_task(task
, NULL
, 1);
4017 struct perf_comm_event
{
4018 struct task_struct
*task
;
4023 struct perf_event_header header
;
4030 static void perf_event_comm_output(struct perf_event
*event
,
4031 struct perf_comm_event
*comm_event
)
4033 struct perf_output_handle handle
;
4034 struct perf_sample_data sample
;
4035 int size
= comm_event
->event_id
.header
.size
;
4038 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4039 ret
= perf_output_begin(&handle
, event
,
4040 comm_event
->event_id
.header
.size
, 0, 0);
4045 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4046 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4048 perf_output_put(&handle
, comm_event
->event_id
);
4049 perf_output_copy(&handle
, comm_event
->comm
,
4050 comm_event
->comm_size
);
4052 perf_event__output_id_sample(event
, &handle
, &sample
);
4054 perf_output_end(&handle
);
4056 comm_event
->event_id
.header
.size
= size
;
4059 static int perf_event_comm_match(struct perf_event
*event
)
4061 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4064 if (!event_filter_match(event
))
4067 if (event
->attr
.comm
)
4073 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4074 struct perf_comm_event
*comm_event
)
4076 struct perf_event
*event
;
4078 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4079 if (perf_event_comm_match(event
))
4080 perf_event_comm_output(event
, comm_event
);
4084 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4086 struct perf_cpu_context
*cpuctx
;
4087 struct perf_event_context
*ctx
;
4088 char comm
[TASK_COMM_LEN
];
4093 memset(comm
, 0, sizeof(comm
));
4094 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4095 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4097 comm_event
->comm
= comm
;
4098 comm_event
->comm_size
= size
;
4100 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4102 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4103 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4104 if (cpuctx
->active_pmu
!= pmu
)
4106 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4108 ctxn
= pmu
->task_ctx_nr
;
4112 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4114 perf_event_comm_ctx(ctx
, comm_event
);
4116 put_cpu_ptr(pmu
->pmu_cpu_context
);
4121 void perf_event_comm(struct task_struct
*task
)
4123 struct perf_comm_event comm_event
;
4124 struct perf_event_context
*ctx
;
4127 for_each_task_context_nr(ctxn
) {
4128 ctx
= task
->perf_event_ctxp
[ctxn
];
4132 perf_event_enable_on_exec(ctx
);
4135 if (!atomic_read(&nr_comm_events
))
4138 comm_event
= (struct perf_comm_event
){
4144 .type
= PERF_RECORD_COMM
,
4153 perf_event_comm_event(&comm_event
);
4160 struct perf_mmap_event
{
4161 struct vm_area_struct
*vma
;
4163 const char *file_name
;
4167 struct perf_event_header header
;
4177 static void perf_event_mmap_output(struct perf_event
*event
,
4178 struct perf_mmap_event
*mmap_event
)
4180 struct perf_output_handle handle
;
4181 struct perf_sample_data sample
;
4182 int size
= mmap_event
->event_id
.header
.size
;
4185 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4186 ret
= perf_output_begin(&handle
, event
,
4187 mmap_event
->event_id
.header
.size
, 0, 0);
4191 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4192 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4194 perf_output_put(&handle
, mmap_event
->event_id
);
4195 perf_output_copy(&handle
, mmap_event
->file_name
,
4196 mmap_event
->file_size
);
4198 perf_event__output_id_sample(event
, &handle
, &sample
);
4200 perf_output_end(&handle
);
4202 mmap_event
->event_id
.header
.size
= size
;
4205 static int perf_event_mmap_match(struct perf_event
*event
,
4206 struct perf_mmap_event
*mmap_event
,
4209 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4212 if (!event_filter_match(event
))
4215 if ((!executable
&& event
->attr
.mmap_data
) ||
4216 (executable
&& event
->attr
.mmap
))
4222 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4223 struct perf_mmap_event
*mmap_event
,
4226 struct perf_event
*event
;
4228 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4229 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4230 perf_event_mmap_output(event
, mmap_event
);
4234 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4236 struct perf_cpu_context
*cpuctx
;
4237 struct perf_event_context
*ctx
;
4238 struct vm_area_struct
*vma
= mmap_event
->vma
;
4239 struct file
*file
= vma
->vm_file
;
4247 memset(tmp
, 0, sizeof(tmp
));
4251 * d_path works from the end of the buffer backwards, so we
4252 * need to add enough zero bytes after the string to handle
4253 * the 64bit alignment we do later.
4255 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4257 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4260 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4262 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4266 if (arch_vma_name(mmap_event
->vma
)) {
4267 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4273 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4275 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4276 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4277 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4279 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4280 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4281 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4285 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4290 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4292 mmap_event
->file_name
= name
;
4293 mmap_event
->file_size
= size
;
4295 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4298 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4299 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4300 if (cpuctx
->active_pmu
!= pmu
)
4302 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4303 vma
->vm_flags
& VM_EXEC
);
4305 ctxn
= pmu
->task_ctx_nr
;
4309 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4311 perf_event_mmap_ctx(ctx
, mmap_event
,
4312 vma
->vm_flags
& VM_EXEC
);
4315 put_cpu_ptr(pmu
->pmu_cpu_context
);
4322 void perf_event_mmap(struct vm_area_struct
*vma
)
4324 struct perf_mmap_event mmap_event
;
4326 if (!atomic_read(&nr_mmap_events
))
4329 mmap_event
= (struct perf_mmap_event
){
4335 .type
= PERF_RECORD_MMAP
,
4336 .misc
= PERF_RECORD_MISC_USER
,
4341 .start
= vma
->vm_start
,
4342 .len
= vma
->vm_end
- vma
->vm_start
,
4343 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4347 perf_event_mmap_event(&mmap_event
);
4351 * IRQ throttle logging
4354 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4356 struct perf_output_handle handle
;
4357 struct perf_sample_data sample
;
4361 struct perf_event_header header
;
4365 } throttle_event
= {
4367 .type
= PERF_RECORD_THROTTLE
,
4369 .size
= sizeof(throttle_event
),
4371 .time
= perf_clock(),
4372 .id
= primary_event_id(event
),
4373 .stream_id
= event
->id
,
4377 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4379 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4381 ret
= perf_output_begin(&handle
, event
,
4382 throttle_event
.header
.size
, 1, 0);
4386 perf_output_put(&handle
, throttle_event
);
4387 perf_event__output_id_sample(event
, &handle
, &sample
);
4388 perf_output_end(&handle
);
4392 * Generic event overflow handling, sampling.
4395 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
4396 int throttle
, struct perf_sample_data
*data
,
4397 struct pt_regs
*regs
)
4399 int events
= atomic_read(&event
->event_limit
);
4400 struct hw_perf_event
*hwc
= &event
->hw
;
4404 * Non-sampling counters might still use the PMI to fold short
4405 * hardware counters, ignore those.
4407 if (unlikely(!is_sampling_event(event
)))
4413 if (hwc
->interrupts
!= MAX_INTERRUPTS
) {
4415 if (HZ
* hwc
->interrupts
>
4416 (u64
)sysctl_perf_event_sample_rate
) {
4417 hwc
->interrupts
= MAX_INTERRUPTS
;
4418 perf_log_throttle(event
, 0);
4423 * Keep re-disabling events even though on the previous
4424 * pass we disabled it - just in case we raced with a
4425 * sched-in and the event got enabled again:
4431 if (event
->attr
.freq
) {
4432 u64 now
= perf_clock();
4433 s64 delta
= now
- hwc
->freq_time_stamp
;
4435 hwc
->freq_time_stamp
= now
;
4437 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4438 perf_adjust_period(event
, delta
, hwc
->last_period
);
4442 * XXX event_limit might not quite work as expected on inherited
4446 event
->pending_kill
= POLL_IN
;
4447 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4449 event
->pending_kill
= POLL_HUP
;
4451 event
->pending_disable
= 1;
4452 irq_work_queue(&event
->pending
);
4454 perf_event_disable(event
);
4457 if (event
->overflow_handler
)
4458 event
->overflow_handler(event
, nmi
, data
, regs
);
4460 perf_event_output(event
, nmi
, data
, regs
);
4465 int perf_event_overflow(struct perf_event
*event
, int nmi
,
4466 struct perf_sample_data
*data
,
4467 struct pt_regs
*regs
)
4469 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
4473 * Generic software event infrastructure
4476 struct swevent_htable
{
4477 struct swevent_hlist
*swevent_hlist
;
4478 struct mutex hlist_mutex
;
4481 /* Recursion avoidance in each contexts */
4482 int recursion
[PERF_NR_CONTEXTS
];
4485 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
4488 * We directly increment event->count and keep a second value in
4489 * event->hw.period_left to count intervals. This period event
4490 * is kept in the range [-sample_period, 0] so that we can use the
4494 static u64
perf_swevent_set_period(struct perf_event
*event
)
4496 struct hw_perf_event
*hwc
= &event
->hw
;
4497 u64 period
= hwc
->last_period
;
4501 hwc
->last_period
= hwc
->sample_period
;
4504 old
= val
= local64_read(&hwc
->period_left
);
4508 nr
= div64_u64(period
+ val
, period
);
4509 offset
= nr
* period
;
4511 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
4517 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
4518 int nmi
, struct perf_sample_data
*data
,
4519 struct pt_regs
*regs
)
4521 struct hw_perf_event
*hwc
= &event
->hw
;
4524 data
->period
= event
->hw
.last_period
;
4526 overflow
= perf_swevent_set_period(event
);
4528 if (hwc
->interrupts
== MAX_INTERRUPTS
)
4531 for (; overflow
; overflow
--) {
4532 if (__perf_event_overflow(event
, nmi
, throttle
,
4535 * We inhibit the overflow from happening when
4536 * hwc->interrupts == MAX_INTERRUPTS.
4544 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
4545 int nmi
, struct perf_sample_data
*data
,
4546 struct pt_regs
*regs
)
4548 struct hw_perf_event
*hwc
= &event
->hw
;
4550 local64_add(nr
, &event
->count
);
4555 if (!is_sampling_event(event
))
4558 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
4559 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
4561 if (local64_add_negative(nr
, &hwc
->period_left
))
4564 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
4567 static int perf_exclude_event(struct perf_event
*event
,
4568 struct pt_regs
*regs
)
4570 if (event
->hw
.state
& PERF_HES_STOPPED
)
4574 if (event
->attr
.exclude_user
&& user_mode(regs
))
4577 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4584 static int perf_swevent_match(struct perf_event
*event
,
4585 enum perf_type_id type
,
4587 struct perf_sample_data
*data
,
4588 struct pt_regs
*regs
)
4590 if (event
->attr
.type
!= type
)
4593 if (event
->attr
.config
!= event_id
)
4596 if (perf_exclude_event(event
, regs
))
4602 static inline u64
swevent_hash(u64 type
, u32 event_id
)
4604 u64 val
= event_id
| (type
<< 32);
4606 return hash_64(val
, SWEVENT_HLIST_BITS
);
4609 static inline struct hlist_head
*
4610 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
4612 u64 hash
= swevent_hash(type
, event_id
);
4614 return &hlist
->heads
[hash
];
4617 /* For the read side: events when they trigger */
4618 static inline struct hlist_head
*
4619 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
4621 struct swevent_hlist
*hlist
;
4623 hlist
= rcu_dereference(swhash
->swevent_hlist
);
4627 return __find_swevent_head(hlist
, type
, event_id
);
4630 /* For the event head insertion and removal in the hlist */
4631 static inline struct hlist_head
*
4632 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
4634 struct swevent_hlist
*hlist
;
4635 u32 event_id
= event
->attr
.config
;
4636 u64 type
= event
->attr
.type
;
4639 * Event scheduling is always serialized against hlist allocation
4640 * and release. Which makes the protected version suitable here.
4641 * The context lock guarantees that.
4643 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
4644 lockdep_is_held(&event
->ctx
->lock
));
4648 return __find_swevent_head(hlist
, type
, event_id
);
4651 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4653 struct perf_sample_data
*data
,
4654 struct pt_regs
*regs
)
4656 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4657 struct perf_event
*event
;
4658 struct hlist_node
*node
;
4659 struct hlist_head
*head
;
4662 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
4666 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4667 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4668 perf_swevent_event(event
, nr
, nmi
, data
, regs
);
4674 int perf_swevent_get_recursion_context(void)
4676 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4678 return get_recursion_context(swhash
->recursion
);
4680 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4682 inline void perf_swevent_put_recursion_context(int rctx
)
4684 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4686 put_recursion_context(swhash
->recursion
, rctx
);
4689 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
4690 struct pt_regs
*regs
, u64 addr
)
4692 struct perf_sample_data data
;
4695 preempt_disable_notrace();
4696 rctx
= perf_swevent_get_recursion_context();
4700 perf_sample_data_init(&data
, addr
);
4702 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
4704 perf_swevent_put_recursion_context(rctx
);
4705 preempt_enable_notrace();
4708 static void perf_swevent_read(struct perf_event
*event
)
4712 static int perf_swevent_add(struct perf_event
*event
, int flags
)
4714 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4715 struct hw_perf_event
*hwc
= &event
->hw
;
4716 struct hlist_head
*head
;
4718 if (is_sampling_event(event
)) {
4719 hwc
->last_period
= hwc
->sample_period
;
4720 perf_swevent_set_period(event
);
4723 hwc
->state
= !(flags
& PERF_EF_START
);
4725 head
= find_swevent_head(swhash
, event
);
4726 if (WARN_ON_ONCE(!head
))
4729 hlist_add_head_rcu(&event
->hlist_entry
, head
);
4734 static void perf_swevent_del(struct perf_event
*event
, int flags
)
4736 hlist_del_rcu(&event
->hlist_entry
);
4739 static void perf_swevent_start(struct perf_event
*event
, int flags
)
4741 event
->hw
.state
= 0;
4744 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
4746 event
->hw
.state
= PERF_HES_STOPPED
;
4749 /* Deref the hlist from the update side */
4750 static inline struct swevent_hlist
*
4751 swevent_hlist_deref(struct swevent_htable
*swhash
)
4753 return rcu_dereference_protected(swhash
->swevent_hlist
,
4754 lockdep_is_held(&swhash
->hlist_mutex
));
4757 static void swevent_hlist_release_rcu(struct rcu_head
*rcu_head
)
4759 struct swevent_hlist
*hlist
;
4761 hlist
= container_of(rcu_head
, struct swevent_hlist
, rcu_head
);
4765 static void swevent_hlist_release(struct swevent_htable
*swhash
)
4767 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
4772 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
4773 call_rcu(&hlist
->rcu_head
, swevent_hlist_release_rcu
);
4776 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
4778 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4780 mutex_lock(&swhash
->hlist_mutex
);
4782 if (!--swhash
->hlist_refcount
)
4783 swevent_hlist_release(swhash
);
4785 mutex_unlock(&swhash
->hlist_mutex
);
4788 static void swevent_hlist_put(struct perf_event
*event
)
4792 if (event
->cpu
!= -1) {
4793 swevent_hlist_put_cpu(event
, event
->cpu
);
4797 for_each_possible_cpu(cpu
)
4798 swevent_hlist_put_cpu(event
, cpu
);
4801 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
4803 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4806 mutex_lock(&swhash
->hlist_mutex
);
4808 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
4809 struct swevent_hlist
*hlist
;
4811 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
4816 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
4818 swhash
->hlist_refcount
++;
4820 mutex_unlock(&swhash
->hlist_mutex
);
4825 static int swevent_hlist_get(struct perf_event
*event
)
4828 int cpu
, failed_cpu
;
4830 if (event
->cpu
!= -1)
4831 return swevent_hlist_get_cpu(event
, event
->cpu
);
4834 for_each_possible_cpu(cpu
) {
4835 err
= swevent_hlist_get_cpu(event
, cpu
);
4845 for_each_possible_cpu(cpu
) {
4846 if (cpu
== failed_cpu
)
4848 swevent_hlist_put_cpu(event
, cpu
);
4855 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4857 static void sw_perf_event_destroy(struct perf_event
*event
)
4859 u64 event_id
= event
->attr
.config
;
4861 WARN_ON(event
->parent
);
4863 jump_label_dec(&perf_swevent_enabled
[event_id
]);
4864 swevent_hlist_put(event
);
4867 static int perf_swevent_init(struct perf_event
*event
)
4869 int event_id
= event
->attr
.config
;
4871 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
4875 case PERF_COUNT_SW_CPU_CLOCK
:
4876 case PERF_COUNT_SW_TASK_CLOCK
:
4883 if (event_id
>= PERF_COUNT_SW_MAX
)
4886 if (!event
->parent
) {
4889 err
= swevent_hlist_get(event
);
4893 jump_label_inc(&perf_swevent_enabled
[event_id
]);
4894 event
->destroy
= sw_perf_event_destroy
;
4900 static struct pmu perf_swevent
= {
4901 .task_ctx_nr
= perf_sw_context
,
4903 .event_init
= perf_swevent_init
,
4904 .add
= perf_swevent_add
,
4905 .del
= perf_swevent_del
,
4906 .start
= perf_swevent_start
,
4907 .stop
= perf_swevent_stop
,
4908 .read
= perf_swevent_read
,
4911 #ifdef CONFIG_EVENT_TRACING
4913 static int perf_tp_filter_match(struct perf_event
*event
,
4914 struct perf_sample_data
*data
)
4916 void *record
= data
->raw
->data
;
4918 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
4923 static int perf_tp_event_match(struct perf_event
*event
,
4924 struct perf_sample_data
*data
,
4925 struct pt_regs
*regs
)
4927 if (event
->hw
.state
& PERF_HES_STOPPED
)
4930 * All tracepoints are from kernel-space.
4932 if (event
->attr
.exclude_kernel
)
4935 if (!perf_tp_filter_match(event
, data
))
4941 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
4942 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
4944 struct perf_sample_data data
;
4945 struct perf_event
*event
;
4946 struct hlist_node
*node
;
4948 struct perf_raw_record raw
= {
4953 perf_sample_data_init(&data
, addr
);
4956 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4957 if (perf_tp_event_match(event
, &data
, regs
))
4958 perf_swevent_event(event
, count
, 1, &data
, regs
);
4961 perf_swevent_put_recursion_context(rctx
);
4963 EXPORT_SYMBOL_GPL(perf_tp_event
);
4965 static void tp_perf_event_destroy(struct perf_event
*event
)
4967 perf_trace_destroy(event
);
4970 static int perf_tp_event_init(struct perf_event
*event
)
4974 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
4977 err
= perf_trace_init(event
);
4981 event
->destroy
= tp_perf_event_destroy
;
4986 static struct pmu perf_tracepoint
= {
4987 .task_ctx_nr
= perf_sw_context
,
4989 .event_init
= perf_tp_event_init
,
4990 .add
= perf_trace_add
,
4991 .del
= perf_trace_del
,
4992 .start
= perf_swevent_start
,
4993 .stop
= perf_swevent_stop
,
4994 .read
= perf_swevent_read
,
4997 static inline void perf_tp_register(void)
4999 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5002 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5007 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5010 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5011 if (IS_ERR(filter_str
))
5012 return PTR_ERR(filter_str
);
5014 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5020 static void perf_event_free_filter(struct perf_event
*event
)
5022 ftrace_profile_free_filter(event
);
5027 static inline void perf_tp_register(void)
5031 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5036 static void perf_event_free_filter(struct perf_event
*event
)
5040 #endif /* CONFIG_EVENT_TRACING */
5042 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5043 void perf_bp_event(struct perf_event
*bp
, void *data
)
5045 struct perf_sample_data sample
;
5046 struct pt_regs
*regs
= data
;
5048 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
5050 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5051 perf_swevent_event(bp
, 1, 1, &sample
, regs
);
5056 * hrtimer based swevent callback
5059 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5061 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5062 struct perf_sample_data data
;
5063 struct pt_regs
*regs
;
5064 struct perf_event
*event
;
5067 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5068 event
->pmu
->read(event
);
5070 perf_sample_data_init(&data
, 0);
5071 data
.period
= event
->hw
.last_period
;
5072 regs
= get_irq_regs();
5074 if (regs
&& !perf_exclude_event(event
, regs
)) {
5075 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
5076 if (perf_event_overflow(event
, 0, &data
, regs
))
5077 ret
= HRTIMER_NORESTART
;
5080 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5081 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5086 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5088 struct hw_perf_event
*hwc
= &event
->hw
;
5091 if (!is_sampling_event(event
))
5094 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5095 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5097 period
= local64_read(&hwc
->period_left
);
5102 local64_set(&hwc
->period_left
, 0);
5104 period
= max_t(u64
, 10000, hwc
->sample_period
);
5106 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5107 ns_to_ktime(period
), 0,
5108 HRTIMER_MODE_REL_PINNED
, 0);
5111 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5113 struct hw_perf_event
*hwc
= &event
->hw
;
5115 if (is_sampling_event(event
)) {
5116 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5117 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5119 hrtimer_cancel(&hwc
->hrtimer
);
5124 * Software event: cpu wall time clock
5127 static void cpu_clock_event_update(struct perf_event
*event
)
5132 now
= local_clock();
5133 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5134 local64_add(now
- prev
, &event
->count
);
5137 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5139 local64_set(&event
->hw
.prev_count
, local_clock());
5140 perf_swevent_start_hrtimer(event
);
5143 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5145 perf_swevent_cancel_hrtimer(event
);
5146 cpu_clock_event_update(event
);
5149 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5151 if (flags
& PERF_EF_START
)
5152 cpu_clock_event_start(event
, flags
);
5157 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5159 cpu_clock_event_stop(event
, flags
);
5162 static void cpu_clock_event_read(struct perf_event
*event
)
5164 cpu_clock_event_update(event
);
5167 static int cpu_clock_event_init(struct perf_event
*event
)
5169 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5172 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5178 static struct pmu perf_cpu_clock
= {
5179 .task_ctx_nr
= perf_sw_context
,
5181 .event_init
= cpu_clock_event_init
,
5182 .add
= cpu_clock_event_add
,
5183 .del
= cpu_clock_event_del
,
5184 .start
= cpu_clock_event_start
,
5185 .stop
= cpu_clock_event_stop
,
5186 .read
= cpu_clock_event_read
,
5190 * Software event: task time clock
5193 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5198 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5200 local64_add(delta
, &event
->count
);
5203 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5205 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5206 perf_swevent_start_hrtimer(event
);
5209 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5211 perf_swevent_cancel_hrtimer(event
);
5212 task_clock_event_update(event
, event
->ctx
->time
);
5215 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5217 if (flags
& PERF_EF_START
)
5218 task_clock_event_start(event
, flags
);
5223 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5225 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5228 static void task_clock_event_read(struct perf_event
*event
)
5233 update_context_time(event
->ctx
);
5234 time
= event
->ctx
->time
;
5236 u64 now
= perf_clock();
5237 u64 delta
= now
- event
->ctx
->timestamp
;
5238 time
= event
->ctx
->time
+ delta
;
5241 task_clock_event_update(event
, time
);
5244 static int task_clock_event_init(struct perf_event
*event
)
5246 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5249 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5255 static struct pmu perf_task_clock
= {
5256 .task_ctx_nr
= perf_sw_context
,
5258 .event_init
= task_clock_event_init
,
5259 .add
= task_clock_event_add
,
5260 .del
= task_clock_event_del
,
5261 .start
= task_clock_event_start
,
5262 .stop
= task_clock_event_stop
,
5263 .read
= task_clock_event_read
,
5266 static void perf_pmu_nop_void(struct pmu
*pmu
)
5270 static int perf_pmu_nop_int(struct pmu
*pmu
)
5275 static void perf_pmu_start_txn(struct pmu
*pmu
)
5277 perf_pmu_disable(pmu
);
5280 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5282 perf_pmu_enable(pmu
);
5286 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5288 perf_pmu_enable(pmu
);
5292 * Ensures all contexts with the same task_ctx_nr have the same
5293 * pmu_cpu_context too.
5295 static void *find_pmu_context(int ctxn
)
5302 list_for_each_entry(pmu
, &pmus
, entry
) {
5303 if (pmu
->task_ctx_nr
== ctxn
)
5304 return pmu
->pmu_cpu_context
;
5310 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5314 for_each_possible_cpu(cpu
) {
5315 struct perf_cpu_context
*cpuctx
;
5317 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5319 if (cpuctx
->active_pmu
== old_pmu
)
5320 cpuctx
->active_pmu
= pmu
;
5324 static void free_pmu_context(struct pmu
*pmu
)
5328 mutex_lock(&pmus_lock
);
5330 * Like a real lame refcount.
5332 list_for_each_entry(i
, &pmus
, entry
) {
5333 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5334 update_pmu_context(i
, pmu
);
5339 free_percpu(pmu
->pmu_cpu_context
);
5341 mutex_unlock(&pmus_lock
);
5343 static struct idr pmu_idr
;
5346 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5348 struct pmu
*pmu
= dev_get_drvdata(dev
);
5350 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5353 static struct device_attribute pmu_dev_attrs
[] = {
5358 static int pmu_bus_running
;
5359 static struct bus_type pmu_bus
= {
5360 .name
= "event_source",
5361 .dev_attrs
= pmu_dev_attrs
,
5364 static void pmu_dev_release(struct device
*dev
)
5369 static int pmu_dev_alloc(struct pmu
*pmu
)
5373 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5377 device_initialize(pmu
->dev
);
5378 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5382 dev_set_drvdata(pmu
->dev
, pmu
);
5383 pmu
->dev
->bus
= &pmu_bus
;
5384 pmu
->dev
->release
= pmu_dev_release
;
5385 ret
= device_add(pmu
->dev
);
5393 put_device(pmu
->dev
);
5397 static struct lock_class_key cpuctx_mutex
;
5399 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5403 mutex_lock(&pmus_lock
);
5405 pmu
->pmu_disable_count
= alloc_percpu(int);
5406 if (!pmu
->pmu_disable_count
)
5415 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
5419 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
5427 if (pmu_bus_running
) {
5428 ret
= pmu_dev_alloc(pmu
);
5434 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
5435 if (pmu
->pmu_cpu_context
)
5436 goto got_cpu_context
;
5438 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
5439 if (!pmu
->pmu_cpu_context
)
5442 for_each_possible_cpu(cpu
) {
5443 struct perf_cpu_context
*cpuctx
;
5445 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5446 __perf_event_init_context(&cpuctx
->ctx
);
5447 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
5448 cpuctx
->ctx
.type
= cpu_context
;
5449 cpuctx
->ctx
.pmu
= pmu
;
5450 cpuctx
->jiffies_interval
= 1;
5451 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
5452 cpuctx
->active_pmu
= pmu
;
5456 if (!pmu
->start_txn
) {
5457 if (pmu
->pmu_enable
) {
5459 * If we have pmu_enable/pmu_disable calls, install
5460 * transaction stubs that use that to try and batch
5461 * hardware accesses.
5463 pmu
->start_txn
= perf_pmu_start_txn
;
5464 pmu
->commit_txn
= perf_pmu_commit_txn
;
5465 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
5467 pmu
->start_txn
= perf_pmu_nop_void
;
5468 pmu
->commit_txn
= perf_pmu_nop_int
;
5469 pmu
->cancel_txn
= perf_pmu_nop_void
;
5473 if (!pmu
->pmu_enable
) {
5474 pmu
->pmu_enable
= perf_pmu_nop_void
;
5475 pmu
->pmu_disable
= perf_pmu_nop_void
;
5478 list_add_rcu(&pmu
->entry
, &pmus
);
5481 mutex_unlock(&pmus_lock
);
5486 device_del(pmu
->dev
);
5487 put_device(pmu
->dev
);
5490 if (pmu
->type
>= PERF_TYPE_MAX
)
5491 idr_remove(&pmu_idr
, pmu
->type
);
5494 free_percpu(pmu
->pmu_disable_count
);
5498 void perf_pmu_unregister(struct pmu
*pmu
)
5500 mutex_lock(&pmus_lock
);
5501 list_del_rcu(&pmu
->entry
);
5502 mutex_unlock(&pmus_lock
);
5505 * We dereference the pmu list under both SRCU and regular RCU, so
5506 * synchronize against both of those.
5508 synchronize_srcu(&pmus_srcu
);
5511 free_percpu(pmu
->pmu_disable_count
);
5512 if (pmu
->type
>= PERF_TYPE_MAX
)
5513 idr_remove(&pmu_idr
, pmu
->type
);
5514 device_del(pmu
->dev
);
5515 put_device(pmu
->dev
);
5516 free_pmu_context(pmu
);
5519 struct pmu
*perf_init_event(struct perf_event
*event
)
5521 struct pmu
*pmu
= NULL
;
5524 idx
= srcu_read_lock(&pmus_srcu
);
5527 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
5532 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5533 int ret
= pmu
->event_init(event
);
5537 if (ret
!= -ENOENT
) {
5542 pmu
= ERR_PTR(-ENOENT
);
5544 srcu_read_unlock(&pmus_srcu
, idx
);
5550 * Allocate and initialize a event structure
5552 static struct perf_event
*
5553 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
5554 struct task_struct
*task
,
5555 struct perf_event
*group_leader
,
5556 struct perf_event
*parent_event
,
5557 perf_overflow_handler_t overflow_handler
)
5560 struct perf_event
*event
;
5561 struct hw_perf_event
*hwc
;
5564 if ((unsigned)cpu
>= nr_cpu_ids
) {
5565 if (!task
|| cpu
!= -1)
5566 return ERR_PTR(-EINVAL
);
5569 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
5571 return ERR_PTR(-ENOMEM
);
5574 * Single events are their own group leaders, with an
5575 * empty sibling list:
5578 group_leader
= event
;
5580 mutex_init(&event
->child_mutex
);
5581 INIT_LIST_HEAD(&event
->child_list
);
5583 INIT_LIST_HEAD(&event
->group_entry
);
5584 INIT_LIST_HEAD(&event
->event_entry
);
5585 INIT_LIST_HEAD(&event
->sibling_list
);
5586 init_waitqueue_head(&event
->waitq
);
5587 init_irq_work(&event
->pending
, perf_pending_event
);
5589 mutex_init(&event
->mmap_mutex
);
5592 event
->attr
= *attr
;
5593 event
->group_leader
= group_leader
;
5597 event
->parent
= parent_event
;
5599 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
5600 event
->id
= atomic64_inc_return(&perf_event_id
);
5602 event
->state
= PERF_EVENT_STATE_INACTIVE
;
5605 event
->attach_state
= PERF_ATTACH_TASK
;
5606 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5608 * hw_breakpoint is a bit difficult here..
5610 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
5611 event
->hw
.bp_target
= task
;
5615 if (!overflow_handler
&& parent_event
)
5616 overflow_handler
= parent_event
->overflow_handler
;
5618 event
->overflow_handler
= overflow_handler
;
5621 event
->state
= PERF_EVENT_STATE_OFF
;
5626 hwc
->sample_period
= attr
->sample_period
;
5627 if (attr
->freq
&& attr
->sample_freq
)
5628 hwc
->sample_period
= 1;
5629 hwc
->last_period
= hwc
->sample_period
;
5631 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5634 * we currently do not support PERF_FORMAT_GROUP on inherited events
5636 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
5639 pmu
= perf_init_event(event
);
5645 else if (IS_ERR(pmu
))
5650 put_pid_ns(event
->ns
);
5652 return ERR_PTR(err
);
5657 if (!event
->parent
) {
5658 if (event
->attach_state
& PERF_ATTACH_TASK
)
5659 jump_label_inc(&perf_task_events
);
5660 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
5661 atomic_inc(&nr_mmap_events
);
5662 if (event
->attr
.comm
)
5663 atomic_inc(&nr_comm_events
);
5664 if (event
->attr
.task
)
5665 atomic_inc(&nr_task_events
);
5666 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5667 err
= get_callchain_buffers();
5670 return ERR_PTR(err
);
5678 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5679 struct perf_event_attr
*attr
)
5684 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
5688 * zero the full structure, so that a short copy will be nice.
5690 memset(attr
, 0, sizeof(*attr
));
5692 ret
= get_user(size
, &uattr
->size
);
5696 if (size
> PAGE_SIZE
) /* silly large */
5699 if (!size
) /* abi compat */
5700 size
= PERF_ATTR_SIZE_VER0
;
5702 if (size
< PERF_ATTR_SIZE_VER0
)
5706 * If we're handed a bigger struct than we know of,
5707 * ensure all the unknown bits are 0 - i.e. new
5708 * user-space does not rely on any kernel feature
5709 * extensions we dont know about yet.
5711 if (size
> sizeof(*attr
)) {
5712 unsigned char __user
*addr
;
5713 unsigned char __user
*end
;
5716 addr
= (void __user
*)uattr
+ sizeof(*attr
);
5717 end
= (void __user
*)uattr
+ size
;
5719 for (; addr
< end
; addr
++) {
5720 ret
= get_user(val
, addr
);
5726 size
= sizeof(*attr
);
5729 ret
= copy_from_user(attr
, uattr
, size
);
5734 * If the type exists, the corresponding creation will verify
5737 if (attr
->type
>= PERF_TYPE_MAX
)
5740 if (attr
->__reserved_1
)
5743 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
5746 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
5753 put_user(sizeof(*attr
), &uattr
->size
);
5759 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
5761 struct perf_buffer
*buffer
= NULL
, *old_buffer
= NULL
;
5767 /* don't allow circular references */
5768 if (event
== output_event
)
5772 * Don't allow cross-cpu buffers
5774 if (output_event
->cpu
!= event
->cpu
)
5778 * If its not a per-cpu buffer, it must be the same task.
5780 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
5784 mutex_lock(&event
->mmap_mutex
);
5785 /* Can't redirect output if we've got an active mmap() */
5786 if (atomic_read(&event
->mmap_count
))
5790 /* get the buffer we want to redirect to */
5791 buffer
= perf_buffer_get(output_event
);
5796 old_buffer
= event
->buffer
;
5797 rcu_assign_pointer(event
->buffer
, buffer
);
5800 mutex_unlock(&event
->mmap_mutex
);
5803 perf_buffer_put(old_buffer
);
5809 * sys_perf_event_open - open a performance event, associate it to a task/cpu
5811 * @attr_uptr: event_id type attributes for monitoring/sampling
5814 * @group_fd: group leader event fd
5816 SYSCALL_DEFINE5(perf_event_open
,
5817 struct perf_event_attr __user
*, attr_uptr
,
5818 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
5820 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
5821 struct perf_event
*event
, *sibling
;
5822 struct perf_event_attr attr
;
5823 struct perf_event_context
*ctx
;
5824 struct file
*event_file
= NULL
;
5825 struct file
*group_file
= NULL
;
5826 struct task_struct
*task
= NULL
;
5830 int fput_needed
= 0;
5833 /* for future expandability... */
5834 if (flags
& ~(PERF_FLAG_FD_NO_GROUP
| PERF_FLAG_FD_OUTPUT
))
5837 err
= perf_copy_attr(attr_uptr
, &attr
);
5841 if (!attr
.exclude_kernel
) {
5842 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
5847 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
5851 event_fd
= get_unused_fd_flags(O_RDWR
);
5855 if (group_fd
!= -1) {
5856 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
5857 if (IS_ERR(group_leader
)) {
5858 err
= PTR_ERR(group_leader
);
5861 group_file
= group_leader
->filp
;
5862 if (flags
& PERF_FLAG_FD_OUTPUT
)
5863 output_event
= group_leader
;
5864 if (flags
& PERF_FLAG_FD_NO_GROUP
)
5865 group_leader
= NULL
;
5869 task
= find_lively_task_by_vpid(pid
);
5871 err
= PTR_ERR(task
);
5876 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
, NULL
);
5877 if (IS_ERR(event
)) {
5878 err
= PTR_ERR(event
);
5883 * Special case software events and allow them to be part of
5884 * any hardware group.
5889 (is_software_event(event
) != is_software_event(group_leader
))) {
5890 if (is_software_event(event
)) {
5892 * If event and group_leader are not both a software
5893 * event, and event is, then group leader is not.
5895 * Allow the addition of software events to !software
5896 * groups, this is safe because software events never
5899 pmu
= group_leader
->pmu
;
5900 } else if (is_software_event(group_leader
) &&
5901 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
5903 * In case the group is a pure software group, and we
5904 * try to add a hardware event, move the whole group to
5905 * the hardware context.
5912 * Get the target context (task or percpu):
5914 ctx
= find_get_context(pmu
, task
, cpu
);
5921 put_task_struct(task
);
5926 * Look up the group leader (we will attach this event to it):
5932 * Do not allow a recursive hierarchy (this new sibling
5933 * becoming part of another group-sibling):
5935 if (group_leader
->group_leader
!= group_leader
)
5938 * Do not allow to attach to a group in a different
5939 * task or CPU context:
5942 if (group_leader
->ctx
->type
!= ctx
->type
)
5945 if (group_leader
->ctx
!= ctx
)
5950 * Only a group leader can be exclusive or pinned
5952 if (attr
.exclusive
|| attr
.pinned
)
5957 err
= perf_event_set_output(event
, output_event
);
5962 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
5963 if (IS_ERR(event_file
)) {
5964 err
= PTR_ERR(event_file
);
5969 struct perf_event_context
*gctx
= group_leader
->ctx
;
5971 mutex_lock(&gctx
->mutex
);
5972 perf_event_remove_from_context(group_leader
);
5973 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
5975 perf_event_remove_from_context(sibling
);
5978 mutex_unlock(&gctx
->mutex
);
5982 event
->filp
= event_file
;
5983 WARN_ON_ONCE(ctx
->parent_ctx
);
5984 mutex_lock(&ctx
->mutex
);
5987 perf_install_in_context(ctx
, group_leader
, cpu
);
5989 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
5991 perf_install_in_context(ctx
, sibling
, cpu
);
5996 perf_install_in_context(ctx
, event
, cpu
);
5998 mutex_unlock(&ctx
->mutex
);
6000 event
->owner
= current
;
6002 mutex_lock(¤t
->perf_event_mutex
);
6003 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6004 mutex_unlock(¤t
->perf_event_mutex
);
6007 * Precalculate sample_data sizes
6009 perf_event__header_size(event
);
6010 perf_event__id_header_size(event
);
6013 * Drop the reference on the group_event after placing the
6014 * new event on the sibling_list. This ensures destruction
6015 * of the group leader will find the pointer to itself in
6016 * perf_group_detach().
6018 fput_light(group_file
, fput_needed
);
6019 fd_install(event_fd
, event_file
);
6028 put_task_struct(task
);
6030 fput_light(group_file
, fput_needed
);
6032 put_unused_fd(event_fd
);
6037 * perf_event_create_kernel_counter
6039 * @attr: attributes of the counter to create
6040 * @cpu: cpu in which the counter is bound
6041 * @task: task to profile (NULL for percpu)
6044 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6045 struct task_struct
*task
,
6046 perf_overflow_handler_t overflow_handler
)
6048 struct perf_event_context
*ctx
;
6049 struct perf_event
*event
;
6053 * Get the target context (task or percpu):
6056 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
, overflow_handler
);
6057 if (IS_ERR(event
)) {
6058 err
= PTR_ERR(event
);
6062 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6069 WARN_ON_ONCE(ctx
->parent_ctx
);
6070 mutex_lock(&ctx
->mutex
);
6071 perf_install_in_context(ctx
, event
, cpu
);
6073 mutex_unlock(&ctx
->mutex
);
6080 return ERR_PTR(err
);
6082 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6084 static void sync_child_event(struct perf_event
*child_event
,
6085 struct task_struct
*child
)
6087 struct perf_event
*parent_event
= child_event
->parent
;
6090 if (child_event
->attr
.inherit_stat
)
6091 perf_event_read_event(child_event
, child
);
6093 child_val
= perf_event_count(child_event
);
6096 * Add back the child's count to the parent's count:
6098 atomic64_add(child_val
, &parent_event
->child_count
);
6099 atomic64_add(child_event
->total_time_enabled
,
6100 &parent_event
->child_total_time_enabled
);
6101 atomic64_add(child_event
->total_time_running
,
6102 &parent_event
->child_total_time_running
);
6105 * Remove this event from the parent's list
6107 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6108 mutex_lock(&parent_event
->child_mutex
);
6109 list_del_init(&child_event
->child_list
);
6110 mutex_unlock(&parent_event
->child_mutex
);
6113 * Release the parent event, if this was the last
6116 fput(parent_event
->filp
);
6120 __perf_event_exit_task(struct perf_event
*child_event
,
6121 struct perf_event_context
*child_ctx
,
6122 struct task_struct
*child
)
6124 if (child_event
->parent
) {
6125 raw_spin_lock_irq(&child_ctx
->lock
);
6126 perf_group_detach(child_event
);
6127 raw_spin_unlock_irq(&child_ctx
->lock
);
6130 perf_event_remove_from_context(child_event
);
6133 * It can happen that the parent exits first, and has events
6134 * that are still around due to the child reference. These
6135 * events need to be zapped.
6137 if (child_event
->parent
) {
6138 sync_child_event(child_event
, child
);
6139 free_event(child_event
);
6143 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6145 struct perf_event
*child_event
, *tmp
;
6146 struct perf_event_context
*child_ctx
;
6147 unsigned long flags
;
6149 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6150 perf_event_task(child
, NULL
, 0);
6154 local_irq_save(flags
);
6156 * We can't reschedule here because interrupts are disabled,
6157 * and either child is current or it is a task that can't be
6158 * scheduled, so we are now safe from rescheduling changing
6161 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6162 task_ctx_sched_out(child_ctx
, EVENT_ALL
);
6165 * Take the context lock here so that if find_get_context is
6166 * reading child->perf_event_ctxp, we wait until it has
6167 * incremented the context's refcount before we do put_ctx below.
6169 raw_spin_lock(&child_ctx
->lock
);
6170 child
->perf_event_ctxp
[ctxn
] = NULL
;
6172 * If this context is a clone; unclone it so it can't get
6173 * swapped to another process while we're removing all
6174 * the events from it.
6176 unclone_ctx(child_ctx
);
6177 update_context_time(child_ctx
);
6178 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6181 * Report the task dead after unscheduling the events so that we
6182 * won't get any samples after PERF_RECORD_EXIT. We can however still
6183 * get a few PERF_RECORD_READ events.
6185 perf_event_task(child
, child_ctx
, 0);
6188 * We can recurse on the same lock type through:
6190 * __perf_event_exit_task()
6191 * sync_child_event()
6192 * fput(parent_event->filp)
6194 * mutex_lock(&ctx->mutex)
6196 * But since its the parent context it won't be the same instance.
6198 mutex_lock(&child_ctx
->mutex
);
6201 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6203 __perf_event_exit_task(child_event
, child_ctx
, child
);
6205 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6207 __perf_event_exit_task(child_event
, child_ctx
, child
);
6210 * If the last event was a group event, it will have appended all
6211 * its siblings to the list, but we obtained 'tmp' before that which
6212 * will still point to the list head terminating the iteration.
6214 if (!list_empty(&child_ctx
->pinned_groups
) ||
6215 !list_empty(&child_ctx
->flexible_groups
))
6218 mutex_unlock(&child_ctx
->mutex
);
6224 * When a child task exits, feed back event values to parent events.
6226 void perf_event_exit_task(struct task_struct
*child
)
6228 struct perf_event
*event
, *tmp
;
6231 mutex_lock(&child
->perf_event_mutex
);
6232 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6234 list_del_init(&event
->owner_entry
);
6237 * Ensure the list deletion is visible before we clear
6238 * the owner, closes a race against perf_release() where
6239 * we need to serialize on the owner->perf_event_mutex.
6242 event
->owner
= NULL
;
6244 mutex_unlock(&child
->perf_event_mutex
);
6246 for_each_task_context_nr(ctxn
)
6247 perf_event_exit_task_context(child
, ctxn
);
6250 static void perf_free_event(struct perf_event
*event
,
6251 struct perf_event_context
*ctx
)
6253 struct perf_event
*parent
= event
->parent
;
6255 if (WARN_ON_ONCE(!parent
))
6258 mutex_lock(&parent
->child_mutex
);
6259 list_del_init(&event
->child_list
);
6260 mutex_unlock(&parent
->child_mutex
);
6264 perf_group_detach(event
);
6265 list_del_event(event
, ctx
);
6270 * free an unexposed, unused context as created by inheritance by
6271 * perf_event_init_task below, used by fork() in case of fail.
6273 void perf_event_free_task(struct task_struct
*task
)
6275 struct perf_event_context
*ctx
;
6276 struct perf_event
*event
, *tmp
;
6279 for_each_task_context_nr(ctxn
) {
6280 ctx
= task
->perf_event_ctxp
[ctxn
];
6284 mutex_lock(&ctx
->mutex
);
6286 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6288 perf_free_event(event
, ctx
);
6290 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6292 perf_free_event(event
, ctx
);
6294 if (!list_empty(&ctx
->pinned_groups
) ||
6295 !list_empty(&ctx
->flexible_groups
))
6298 mutex_unlock(&ctx
->mutex
);
6304 void perf_event_delayed_put(struct task_struct
*task
)
6308 for_each_task_context_nr(ctxn
)
6309 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6313 * inherit a event from parent task to child task:
6315 static struct perf_event
*
6316 inherit_event(struct perf_event
*parent_event
,
6317 struct task_struct
*parent
,
6318 struct perf_event_context
*parent_ctx
,
6319 struct task_struct
*child
,
6320 struct perf_event
*group_leader
,
6321 struct perf_event_context
*child_ctx
)
6323 struct perf_event
*child_event
;
6324 unsigned long flags
;
6327 * Instead of creating recursive hierarchies of events,
6328 * we link inherited events back to the original parent,
6329 * which has a filp for sure, which we use as the reference
6332 if (parent_event
->parent
)
6333 parent_event
= parent_event
->parent
;
6335 child_event
= perf_event_alloc(&parent_event
->attr
,
6338 group_leader
, parent_event
,
6340 if (IS_ERR(child_event
))
6345 * Make the child state follow the state of the parent event,
6346 * not its attr.disabled bit. We hold the parent's mutex,
6347 * so we won't race with perf_event_{en, dis}able_family.
6349 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6350 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6352 child_event
->state
= PERF_EVENT_STATE_OFF
;
6354 if (parent_event
->attr
.freq
) {
6355 u64 sample_period
= parent_event
->hw
.sample_period
;
6356 struct hw_perf_event
*hwc
= &child_event
->hw
;
6358 hwc
->sample_period
= sample_period
;
6359 hwc
->last_period
= sample_period
;
6361 local64_set(&hwc
->period_left
, sample_period
);
6364 child_event
->ctx
= child_ctx
;
6365 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6368 * Precalculate sample_data sizes
6370 perf_event__header_size(child_event
);
6371 perf_event__id_header_size(child_event
);
6374 * Link it up in the child's context:
6376 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6377 add_event_to_ctx(child_event
, child_ctx
);
6378 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6381 * Get a reference to the parent filp - we will fput it
6382 * when the child event exits. This is safe to do because
6383 * we are in the parent and we know that the filp still
6384 * exists and has a nonzero count:
6386 atomic_long_inc(&parent_event
->filp
->f_count
);
6389 * Link this into the parent event's child list
6391 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6392 mutex_lock(&parent_event
->child_mutex
);
6393 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
6394 mutex_unlock(&parent_event
->child_mutex
);
6399 static int inherit_group(struct perf_event
*parent_event
,
6400 struct task_struct
*parent
,
6401 struct perf_event_context
*parent_ctx
,
6402 struct task_struct
*child
,
6403 struct perf_event_context
*child_ctx
)
6405 struct perf_event
*leader
;
6406 struct perf_event
*sub
;
6407 struct perf_event
*child_ctr
;
6409 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
6410 child
, NULL
, child_ctx
);
6412 return PTR_ERR(leader
);
6413 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
6414 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
6415 child
, leader
, child_ctx
);
6416 if (IS_ERR(child_ctr
))
6417 return PTR_ERR(child_ctr
);
6423 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
6424 struct perf_event_context
*parent_ctx
,
6425 struct task_struct
*child
, int ctxn
,
6429 struct perf_event_context
*child_ctx
;
6431 if (!event
->attr
.inherit
) {
6436 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6439 * This is executed from the parent task context, so
6440 * inherit events that have been marked for cloning.
6441 * First allocate and initialize a context for the
6445 child_ctx
= alloc_perf_context(event
->pmu
, child
);
6449 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
6452 ret
= inherit_group(event
, parent
, parent_ctx
,
6462 * Initialize the perf_event context in task_struct
6464 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
6466 struct perf_event_context
*child_ctx
, *parent_ctx
;
6467 struct perf_event_context
*cloned_ctx
;
6468 struct perf_event
*event
;
6469 struct task_struct
*parent
= current
;
6470 int inherited_all
= 1;
6471 unsigned long flags
;
6474 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
6478 * If the parent's context is a clone, pin it so it won't get
6481 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
6484 * No need to check if parent_ctx != NULL here; since we saw
6485 * it non-NULL earlier, the only reason for it to become NULL
6486 * is if we exit, and since we're currently in the middle of
6487 * a fork we can't be exiting at the same time.
6491 * Lock the parent list. No need to lock the child - not PID
6492 * hashed yet and not running, so nobody can access it.
6494 mutex_lock(&parent_ctx
->mutex
);
6497 * We dont have to disable NMIs - we are only looking at
6498 * the list, not manipulating it:
6500 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
6501 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6502 child
, ctxn
, &inherited_all
);
6508 * We can't hold ctx->lock when iterating the ->flexible_group list due
6509 * to allocations, but we need to prevent rotation because
6510 * rotate_ctx() will change the list from interrupt context.
6512 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6513 parent_ctx
->rotate_disable
= 1;
6514 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6516 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
6517 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6518 child
, ctxn
, &inherited_all
);
6523 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6524 parent_ctx
->rotate_disable
= 0;
6526 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6528 if (child_ctx
&& inherited_all
) {
6530 * Mark the child context as a clone of the parent
6531 * context, or of whatever the parent is a clone of.
6533 * Note that if the parent is a clone, the holding of
6534 * parent_ctx->lock avoids it from being uncloned.
6536 cloned_ctx
= parent_ctx
->parent_ctx
;
6538 child_ctx
->parent_ctx
= cloned_ctx
;
6539 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
6541 child_ctx
->parent_ctx
= parent_ctx
;
6542 child_ctx
->parent_gen
= parent_ctx
->generation
;
6544 get_ctx(child_ctx
->parent_ctx
);
6547 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6548 mutex_unlock(&parent_ctx
->mutex
);
6550 perf_unpin_context(parent_ctx
);
6556 * Initialize the perf_event context in task_struct
6558 int perf_event_init_task(struct task_struct
*child
)
6562 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
6563 mutex_init(&child
->perf_event_mutex
);
6564 INIT_LIST_HEAD(&child
->perf_event_list
);
6566 for_each_task_context_nr(ctxn
) {
6567 ret
= perf_event_init_context(child
, ctxn
);
6575 static void __init
perf_event_init_all_cpus(void)
6577 struct swevent_htable
*swhash
;
6580 for_each_possible_cpu(cpu
) {
6581 swhash
= &per_cpu(swevent_htable
, cpu
);
6582 mutex_init(&swhash
->hlist_mutex
);
6583 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
6587 static void __cpuinit
perf_event_init_cpu(int cpu
)
6589 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6591 mutex_lock(&swhash
->hlist_mutex
);
6592 if (swhash
->hlist_refcount
> 0) {
6593 struct swevent_hlist
*hlist
;
6595 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
6597 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6599 mutex_unlock(&swhash
->hlist_mutex
);
6602 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
6603 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
6605 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6607 WARN_ON(!irqs_disabled());
6609 list_del_init(&cpuctx
->rotation_list
);
6612 static void __perf_event_exit_context(void *__info
)
6614 struct perf_event_context
*ctx
= __info
;
6615 struct perf_event
*event
, *tmp
;
6617 perf_pmu_rotate_stop(ctx
->pmu
);
6619 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
6620 __perf_event_remove_from_context(event
);
6621 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
6622 __perf_event_remove_from_context(event
);
6625 static void perf_event_exit_cpu_context(int cpu
)
6627 struct perf_event_context
*ctx
;
6631 idx
= srcu_read_lock(&pmus_srcu
);
6632 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6633 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
6635 mutex_lock(&ctx
->mutex
);
6636 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
6637 mutex_unlock(&ctx
->mutex
);
6639 srcu_read_unlock(&pmus_srcu
, idx
);
6642 static void perf_event_exit_cpu(int cpu
)
6644 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6646 mutex_lock(&swhash
->hlist_mutex
);
6647 swevent_hlist_release(swhash
);
6648 mutex_unlock(&swhash
->hlist_mutex
);
6650 perf_event_exit_cpu_context(cpu
);
6653 static inline void perf_event_exit_cpu(int cpu
) { }
6657 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
6661 for_each_online_cpu(cpu
)
6662 perf_event_exit_cpu(cpu
);
6668 * Run the perf reboot notifier at the very last possible moment so that
6669 * the generic watchdog code runs as long as possible.
6671 static struct notifier_block perf_reboot_notifier
= {
6672 .notifier_call
= perf_reboot
,
6673 .priority
= INT_MIN
,
6676 static int __cpuinit
6677 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
6679 unsigned int cpu
= (long)hcpu
;
6681 switch (action
& ~CPU_TASKS_FROZEN
) {
6683 case CPU_UP_PREPARE
:
6684 case CPU_DOWN_FAILED
:
6685 perf_event_init_cpu(cpu
);
6688 case CPU_UP_CANCELED
:
6689 case CPU_DOWN_PREPARE
:
6690 perf_event_exit_cpu(cpu
);
6700 void __init
perf_event_init(void)
6706 perf_event_init_all_cpus();
6707 init_srcu_struct(&pmus_srcu
);
6708 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
6709 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
6710 perf_pmu_register(&perf_task_clock
, NULL
, -1);
6712 perf_cpu_notifier(perf_cpu_notify
);
6713 register_reboot_notifier(&perf_reboot_notifier
);
6715 ret
= init_hw_breakpoint();
6716 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
6719 static int __init
perf_event_sysfs_init(void)
6724 mutex_lock(&pmus_lock
);
6726 ret
= bus_register(&pmu_bus
);
6730 list_for_each_entry(pmu
, &pmus
, entry
) {
6731 if (!pmu
->name
|| pmu
->type
< 0)
6734 ret
= pmu_dev_alloc(pmu
);
6735 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
6737 pmu_bus_running
= 1;
6741 mutex_unlock(&pmus_lock
);
6745 device_initcall(perf_event_sysfs_init
);