2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/file.h>
17 #include <linux/poll.h>
18 #include <linux/sysfs.h>
19 #include <linux/dcache.h>
20 #include <linux/percpu.h>
21 #include <linux/ptrace.h>
22 #include <linux/vmstat.h>
23 #include <linux/vmalloc.h>
24 #include <linux/hardirq.h>
25 #include <linux/rculist.h>
26 #include <linux/uaccess.h>
27 #include <linux/syscalls.h>
28 #include <linux/anon_inodes.h>
29 #include <linux/kernel_stat.h>
30 #include <linux/perf_event.h>
31 #include <linux/ftrace_event.h>
32 #include <linux/hw_breakpoint.h>
34 #include <asm/irq_regs.h>
37 * Each CPU has a list of per CPU events:
39 static DEFINE_PER_CPU(struct perf_cpu_context, perf_cpu_context);
41 int perf_max_events __read_mostly = 1;
42 static int perf_reserved_percpu __read_mostly;
43 static int perf_overcommit __read_mostly = 1;
45 static atomic_t nr_events __read_mostly;
46 static atomic_t nr_mmap_events __read_mostly;
47 static atomic_t nr_comm_events __read_mostly;
48 static atomic_t nr_task_events __read_mostly;
51 * perf event paranoia level:
52 * -1 - not paranoid at all
53 * 0 - disallow raw tracepoint access for unpriv
54 * 1 - disallow cpu events for unpriv
55 * 2 - disallow kernel profiling for unpriv
57 int sysctl_perf_event_paranoid __read_mostly = 1;
59 static inline bool perf_paranoid_tracepoint_raw(void)
61 return sysctl_perf_event_paranoid > -1;
64 static inline bool perf_paranoid_cpu(void)
66 return sysctl_perf_event_paranoid > 0;
69 static inline bool perf_paranoid_kernel(void)
71 return sysctl_perf_event_paranoid > 1;
74 int sysctl_perf_event_mlock __read_mostly = 512; /* 'free' kb per user */
77 * max perf event sample rate
79 int sysctl_perf_event_sample_rate __read_mostly = 100000;
81 static atomic64_t perf_event_id;
84 * Lock for (sysadmin-configurable) event reservations:
86 static DEFINE_SPINLOCK(perf_resource_lock);
89 * Architecture provided APIs - weak aliases:
91 extern __weak const struct pmu *hw_perf_event_init(struct perf_event *event)
96 void __weak hw_perf_disable(void) { barrier(); }
97 void __weak hw_perf_enable(void) { barrier(); }
99 void __weak hw_perf_event_setup(int cpu) { barrier(); }
100 void __weak hw_perf_event_setup_online(int cpu) { barrier(); }
103 hw_perf_group_sched_in(struct perf_event *group_leader,
104 struct perf_cpu_context *cpuctx,
105 struct perf_event_context *ctx, int cpu)
110 void __weak perf_event_print_debug(void) { }
112 static DEFINE_PER_CPU(int, perf_disable_count);
114 void __perf_disable(void)
116 __get_cpu_var(perf_disable_count)++;
119 bool __perf_enable(void)
121 return !--__get_cpu_var(perf_disable_count);
124 void perf_disable(void)
130 void perf_enable(void)
136 static void get_ctx(struct perf_event_context *ctx)
138 WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
141 static void free_ctx(struct rcu_head *head)
143 struct perf_event_context *ctx;
145 ctx = container_of(head, struct perf_event_context, rcu_head);
149 static void put_ctx(struct perf_event_context *ctx)
151 if (atomic_dec_and_test(&ctx->refcount)) {
153 put_ctx(ctx->parent_ctx);
155 put_task_struct(ctx->task);
156 call_rcu(&ctx->rcu_head, free_ctx);
160 static void unclone_ctx(struct perf_event_context *ctx)
162 if (ctx->parent_ctx) {
163 put_ctx(ctx->parent_ctx);
164 ctx->parent_ctx = NULL;
169 * If we inherit events we want to return the parent event id
172 static u64 primary_event_id(struct perf_event *event)
177 id = event->parent->id;
183 * Get the perf_event_context for a task and lock it.
184 * This has to cope with with the fact that until it is locked,
185 * the context could get moved to another task.
187 static struct perf_event_context *
188 perf_lock_task_context(struct task_struct *task, unsigned long *flags)
190 struct perf_event_context *ctx;
194 ctx = rcu_dereference(task->perf_event_ctxp);
197 * If this context is a clone of another, it might
198 * get swapped for another underneath us by
199 * perf_event_task_sched_out, though the
200 * rcu_read_lock() protects us from any context
201 * getting freed. Lock the context and check if it
202 * got swapped before we could get the lock, and retry
203 * if so. If we locked the right context, then it
204 * can't get swapped on us any more.
206 raw_spin_lock_irqsave(&ctx->lock, *flags);
207 if (ctx != rcu_dereference(task->perf_event_ctxp)) {
208 raw_spin_unlock_irqrestore(&ctx->lock, *flags);
212 if (!atomic_inc_not_zero(&ctx->refcount)) {
213 raw_spin_unlock_irqrestore(&ctx->lock, *flags);
222 * Get the context for a task and increment its pin_count so it
223 * can't get swapped to another task. This also increments its
224 * reference count so that the context can't get freed.
226 static struct perf_event_context *perf_pin_task_context(struct task_struct *task)
228 struct perf_event_context *ctx;
231 ctx = perf_lock_task_context(task, &flags);
234 raw_spin_unlock_irqrestore(&ctx->lock, flags);
239 static void perf_unpin_context(struct perf_event_context *ctx)
243 raw_spin_lock_irqsave(&ctx->lock, flags);
245 raw_spin_unlock_irqrestore(&ctx->lock, flags);
249 static inline u64 perf_clock(void)
251 return cpu_clock(smp_processor_id());
255 * Update the record of the current time in a context.
257 static void update_context_time(struct perf_event_context *ctx)
259 u64 now = perf_clock();
261 ctx->time += now - ctx->timestamp;
262 ctx->timestamp = now;
266 * Update the total_time_enabled and total_time_running fields for a event.
268 static void update_event_times(struct perf_event *event)
270 struct perf_event_context *ctx = event->ctx;
273 if (event->state < PERF_EVENT_STATE_INACTIVE ||
274 event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
280 run_end = event->tstamp_stopped;
282 event->total_time_enabled = run_end - event->tstamp_enabled;
284 if (event->state == PERF_EVENT_STATE_INACTIVE)
285 run_end = event->tstamp_stopped;
289 event->total_time_running = run_end - event->tstamp_running;
293 * Add a event from the lists for its context.
294 * Must be called with ctx->mutex and ctx->lock held.
297 list_add_event(struct perf_event *event, struct perf_event_context *ctx)
299 struct perf_event *group_leader = event->group_leader;
302 * Depending on whether it is a standalone or sibling event,
303 * add it straight to the context's event list, or to the group
304 * leader's sibling list:
306 if (group_leader == event)
307 list_add_tail(&event->group_entry, &ctx->group_list);
309 list_add_tail(&event->group_entry, &group_leader->sibling_list);
310 group_leader->nr_siblings++;
313 list_add_rcu(&event->event_entry, &ctx->event_list);
315 if (event->attr.inherit_stat)
320 * Remove a event from the lists for its context.
321 * Must be called with ctx->mutex and ctx->lock held.
324 list_del_event(struct perf_event *event, struct perf_event_context *ctx)
326 struct perf_event *sibling, *tmp;
328 if (list_empty(&event->group_entry))
331 if (event->attr.inherit_stat)
334 list_del_init(&event->group_entry);
335 list_del_rcu(&event->event_entry);
337 if (event->group_leader != event)
338 event->group_leader->nr_siblings--;
340 update_event_times(event);
343 * If event was in error state, then keep it
344 * that way, otherwise bogus counts will be
345 * returned on read(). The only way to get out
346 * of error state is by explicit re-enabling
349 if (event->state > PERF_EVENT_STATE_OFF)
350 event->state = PERF_EVENT_STATE_OFF;
353 * If this was a group event with sibling events then
354 * upgrade the siblings to singleton events by adding them
355 * to the context list directly:
357 list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
359 list_move_tail(&sibling->group_entry, &ctx->group_list);
360 sibling->group_leader = sibling;
365 event_sched_out(struct perf_event *event,
366 struct perf_cpu_context *cpuctx,
367 struct perf_event_context *ctx)
369 if (event->state != PERF_EVENT_STATE_ACTIVE)
372 event->state = PERF_EVENT_STATE_INACTIVE;
373 if (event->pending_disable) {
374 event->pending_disable = 0;
375 event->state = PERF_EVENT_STATE_OFF;
377 event->tstamp_stopped = ctx->time;
378 event->pmu->disable(event);
381 if (!is_software_event(event))
382 cpuctx->active_oncpu--;
384 if (event->attr.exclusive || !cpuctx->active_oncpu)
385 cpuctx->exclusive = 0;
389 group_sched_out(struct perf_event *group_event,
390 struct perf_cpu_context *cpuctx,
391 struct perf_event_context *ctx)
393 struct perf_event *event;
395 if (group_event->state != PERF_EVENT_STATE_ACTIVE)
398 event_sched_out(group_event, cpuctx, ctx);
401 * Schedule out siblings (if any):
403 list_for_each_entry(event, &group_event->sibling_list, group_entry)
404 event_sched_out(event, cpuctx, ctx);
406 if (group_event->attr.exclusive)
407 cpuctx->exclusive = 0;
411 * Cross CPU call to remove a performance event
413 * We disable the event on the hardware level first. After that we
414 * remove it from the context list.
416 static void __perf_event_remove_from_context(void *info)
418 struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
419 struct perf_event *event = info;
420 struct perf_event_context *ctx = event->ctx;
423 * If this is a task context, we need to check whether it is
424 * the current task context of this cpu. If not it has been
425 * scheduled out before the smp call arrived.
427 if (ctx->task && cpuctx->task_ctx != ctx)
430 raw_spin_lock(&ctx->lock);
432 * Protect the list operation against NMI by disabling the
433 * events on a global level.
437 event_sched_out(event, cpuctx, ctx);
439 list_del_event(event, ctx);
443 * Allow more per task events with respect to the
446 cpuctx->max_pertask =
447 min(perf_max_events - ctx->nr_events,
448 perf_max_events - perf_reserved_percpu);
452 raw_spin_unlock(&ctx->lock);
457 * Remove the event from a task's (or a CPU's) list of events.
459 * Must be called with ctx->mutex held.
461 * CPU events are removed with a smp call. For task events we only
462 * call when the task is on a CPU.
464 * If event->ctx is a cloned context, callers must make sure that
465 * every task struct that event->ctx->task could possibly point to
466 * remains valid. This is OK when called from perf_release since
467 * that only calls us on the top-level context, which can't be a clone.
468 * When called from perf_event_exit_task, it's OK because the
469 * context has been detached from its task.
471 static void perf_event_remove_from_context(struct perf_event *event)
473 struct perf_event_context *ctx = event->ctx;
474 struct task_struct *task = ctx->task;
478 * Per cpu events are removed via an smp call and
479 * the removal is always successful.
481 smp_call_function_single(event->cpu,
482 __perf_event_remove_from_context,
488 task_oncpu_function_call(task, __perf_event_remove_from_context,
491 raw_spin_lock_irq(&ctx->lock);
493 * If the context is active we need to retry the smp call.
495 if (ctx->nr_active && !list_empty(&event->group_entry)) {
496 raw_spin_unlock_irq(&ctx->lock);
501 * The lock prevents that this context is scheduled in so we
502 * can remove the event safely, if the call above did not
505 if (!list_empty(&event->group_entry))
506 list_del_event(event, ctx);
507 raw_spin_unlock_irq(&ctx->lock);
511 * Update total_time_enabled and total_time_running for all events in a group.
513 static void update_group_times(struct perf_event *leader)
515 struct perf_event *event;
517 update_event_times(leader);
518 list_for_each_entry(event, &leader->sibling_list, group_entry)
519 update_event_times(event);
523 * Cross CPU call to disable a performance event
525 static void __perf_event_disable(void *info)
527 struct perf_event *event = info;
528 struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
529 struct perf_event_context *ctx = event->ctx;
532 * If this is a per-task event, need to check whether this
533 * event's task is the current task on this cpu.
535 if (ctx->task && cpuctx->task_ctx != ctx)
538 raw_spin_lock(&ctx->lock);
541 * If the event is on, turn it off.
542 * If it is in error state, leave it in error state.
544 if (event->state >= PERF_EVENT_STATE_INACTIVE) {
545 update_context_time(ctx);
546 update_group_times(event);
547 if (event == event->group_leader)
548 group_sched_out(event, cpuctx, ctx);
550 event_sched_out(event, cpuctx, ctx);
551 event->state = PERF_EVENT_STATE_OFF;
554 raw_spin_unlock(&ctx->lock);
560 * If event->ctx is a cloned context, callers must make sure that
561 * every task struct that event->ctx->task could possibly point to
562 * remains valid. This condition is satisifed when called through
563 * perf_event_for_each_child or perf_event_for_each because they
564 * hold the top-level event's child_mutex, so any descendant that
565 * goes to exit will block in sync_child_event.
566 * When called from perf_pending_event it's OK because event->ctx
567 * is the current context on this CPU and preemption is disabled,
568 * hence we can't get into perf_event_task_sched_out for this context.
570 void perf_event_disable(struct perf_event *event)
572 struct perf_event_context *ctx = event->ctx;
573 struct task_struct *task = ctx->task;
577 * Disable the event on the cpu that it's on
579 smp_call_function_single(event->cpu, __perf_event_disable,
585 task_oncpu_function_call(task, __perf_event_disable, event);
587 raw_spin_lock_irq(&ctx->lock);
589 * If the event is still active, we need to retry the cross-call.
591 if (event->state == PERF_EVENT_STATE_ACTIVE) {
592 raw_spin_unlock_irq(&ctx->lock);
597 * Since we have the lock this context can't be scheduled
598 * in, so we can change the state safely.
600 if (event->state == PERF_EVENT_STATE_INACTIVE) {
601 update_group_times(event);
602 event->state = PERF_EVENT_STATE_OFF;
605 raw_spin_unlock_irq(&ctx->lock);
609 event_sched_in(struct perf_event *event,
610 struct perf_cpu_context *cpuctx,
611 struct perf_event_context *ctx,
614 if (event->state <= PERF_EVENT_STATE_OFF)
617 event->state = PERF_EVENT_STATE_ACTIVE;
618 event->oncpu = cpu; /* TODO: put 'cpu' into cpuctx->cpu */
620 * The new state must be visible before we turn it on in the hardware:
624 if (event->pmu->enable(event)) {
625 event->state = PERF_EVENT_STATE_INACTIVE;
630 event->tstamp_running += ctx->time - event->tstamp_stopped;
632 if (!is_software_event(event))
633 cpuctx->active_oncpu++;
636 if (event->attr.exclusive)
637 cpuctx->exclusive = 1;
643 group_sched_in(struct perf_event *group_event,
644 struct perf_cpu_context *cpuctx,
645 struct perf_event_context *ctx,
648 struct perf_event *event, *partial_group;
651 if (group_event->state == PERF_EVENT_STATE_OFF)
654 ret = hw_perf_group_sched_in(group_event, cpuctx, ctx, cpu);
656 return ret < 0 ? ret : 0;
658 if (event_sched_in(group_event, cpuctx, ctx, cpu))
662 * Schedule in siblings as one group (if any):
664 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
665 if (event_sched_in(event, cpuctx, ctx, cpu)) {
666 partial_group = event;
675 * Groups can be scheduled in as one unit only, so undo any
676 * partial group before returning:
678 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
679 if (event == partial_group)
681 event_sched_out(event, cpuctx, ctx);
683 event_sched_out(group_event, cpuctx, ctx);
689 * Return 1 for a group consisting entirely of software events,
690 * 0 if the group contains any hardware events.
692 static int is_software_only_group(struct perf_event *leader)
694 struct perf_event *event;
696 if (!is_software_event(leader))
699 list_for_each_entry(event, &leader->sibling_list, group_entry)
700 if (!is_software_event(event))
707 * Work out whether we can put this event group on the CPU now.
709 static int group_can_go_on(struct perf_event *event,
710 struct perf_cpu_context *cpuctx,
714 * Groups consisting entirely of software events can always go on.
716 if (is_software_only_group(event))
719 * If an exclusive group is already on, no other hardware
722 if (cpuctx->exclusive)
725 * If this group is exclusive and there are already
726 * events on the CPU, it can't go on.
728 if (event->attr.exclusive && cpuctx->active_oncpu)
731 * Otherwise, try to add it if all previous groups were able
737 static void add_event_to_ctx(struct perf_event *event,
738 struct perf_event_context *ctx)
740 list_add_event(event, ctx);
741 event->tstamp_enabled = ctx->time;
742 event->tstamp_running = ctx->time;
743 event->tstamp_stopped = ctx->time;
747 * Cross CPU call to install and enable a performance event
749 * Must be called with ctx->mutex held
751 static void __perf_install_in_context(void *info)
753 struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
754 struct perf_event *event = info;
755 struct perf_event_context *ctx = event->ctx;
756 struct perf_event *leader = event->group_leader;
757 int cpu = smp_processor_id();
761 * If this is a task context, we need to check whether it is
762 * the current task context of this cpu. If not it has been
763 * scheduled out before the smp call arrived.
764 * Or possibly this is the right context but it isn't
765 * on this cpu because it had no events.
767 if (ctx->task && cpuctx->task_ctx != ctx) {
768 if (cpuctx->task_ctx || ctx->task != current)
770 cpuctx->task_ctx = ctx;
773 raw_spin_lock(&ctx->lock);
775 update_context_time(ctx);
778 * Protect the list operation against NMI by disabling the
779 * events on a global level. NOP for non NMI based events.
783 add_event_to_ctx(event, ctx);
785 if (event->cpu != -1 && event->cpu != smp_processor_id())
789 * Don't put the event on if it is disabled or if
790 * it is in a group and the group isn't on.
792 if (event->state != PERF_EVENT_STATE_INACTIVE ||
793 (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE))
797 * An exclusive event can't go on if there are already active
798 * hardware events, and no hardware event can go on if there
799 * is already an exclusive event on.
801 if (!group_can_go_on(event, cpuctx, 1))
804 err = event_sched_in(event, cpuctx, ctx, cpu);
808 * This event couldn't go on. If it is in a group
809 * then we have to pull the whole group off.
810 * If the event group is pinned then put it in error state.
813 group_sched_out(leader, cpuctx, ctx);
814 if (leader->attr.pinned) {
815 update_group_times(leader);
816 leader->state = PERF_EVENT_STATE_ERROR;
820 if (!err && !ctx->task && cpuctx->max_pertask)
821 cpuctx->max_pertask--;
826 raw_spin_unlock(&ctx->lock);
830 * Attach a performance event to a context
832 * First we add the event to the list with the hardware enable bit
833 * in event->hw_config cleared.
835 * If the event is attached to a task which is on a CPU we use a smp
836 * call to enable it in the task context. The task might have been
837 * scheduled away, but we check this in the smp call again.
839 * Must be called with ctx->mutex held.
842 perf_install_in_context(struct perf_event_context *ctx,
843 struct perf_event *event,
846 struct task_struct *task = ctx->task;
850 * Per cpu events are installed via an smp call and
851 * the install is always successful.
853 smp_call_function_single(cpu, __perf_install_in_context,
859 task_oncpu_function_call(task, __perf_install_in_context,
862 raw_spin_lock_irq(&ctx->lock);
864 * we need to retry the smp call.
866 if (ctx->is_active && list_empty(&event->group_entry)) {
867 raw_spin_unlock_irq(&ctx->lock);
872 * The lock prevents that this context is scheduled in so we
873 * can add the event safely, if it the call above did not
876 if (list_empty(&event->group_entry))
877 add_event_to_ctx(event, ctx);
878 raw_spin_unlock_irq(&ctx->lock);
882 * Put a event into inactive state and update time fields.
883 * Enabling the leader of a group effectively enables all
884 * the group members that aren't explicitly disabled, so we
885 * have to update their ->tstamp_enabled also.
886 * Note: this works for group members as well as group leaders
887 * since the non-leader members' sibling_lists will be empty.
889 static void __perf_event_mark_enabled(struct perf_event *event,
890 struct perf_event_context *ctx)
892 struct perf_event *sub;
894 event->state = PERF_EVENT_STATE_INACTIVE;
895 event->tstamp_enabled = ctx->time - event->total_time_enabled;
896 list_for_each_entry(sub, &event->sibling_list, group_entry)
897 if (sub->state >= PERF_EVENT_STATE_INACTIVE)
898 sub->tstamp_enabled =
899 ctx->time - sub->total_time_enabled;
903 * Cross CPU call to enable a performance event
905 static void __perf_event_enable(void *info)
907 struct perf_event *event = info;
908 struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
909 struct perf_event_context *ctx = event->ctx;
910 struct perf_event *leader = event->group_leader;
914 * If this is a per-task event, need to check whether this
915 * event's task is the current task on this cpu.
917 if (ctx->task && cpuctx->task_ctx != ctx) {
918 if (cpuctx->task_ctx || ctx->task != current)
920 cpuctx->task_ctx = ctx;
923 raw_spin_lock(&ctx->lock);
925 update_context_time(ctx);
927 if (event->state >= PERF_EVENT_STATE_INACTIVE)
929 __perf_event_mark_enabled(event, ctx);
931 if (event->cpu != -1 && event->cpu != smp_processor_id())
935 * If the event is in a group and isn't the group leader,
936 * then don't put it on unless the group is on.
938 if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
941 if (!group_can_go_on(event, cpuctx, 1)) {
946 err = group_sched_in(event, cpuctx, ctx,
949 err = event_sched_in(event, cpuctx, ctx,
956 * If this event can't go on and it's part of a
957 * group, then the whole group has to come off.
960 group_sched_out(leader, cpuctx, ctx);
961 if (leader->attr.pinned) {
962 update_group_times(leader);
963 leader->state = PERF_EVENT_STATE_ERROR;
968 raw_spin_unlock(&ctx->lock);
974 * If event->ctx is a cloned context, callers must make sure that
975 * every task struct that event->ctx->task could possibly point to
976 * remains valid. This condition is satisfied when called through
977 * perf_event_for_each_child or perf_event_for_each as described
978 * for perf_event_disable.
980 void perf_event_enable(struct perf_event *event)
982 struct perf_event_context *ctx = event->ctx;
983 struct task_struct *task = ctx->task;
987 * Enable the event on the cpu that it's on
989 smp_call_function_single(event->cpu, __perf_event_enable,
994 raw_spin_lock_irq(&ctx->lock);
995 if (event->state >= PERF_EVENT_STATE_INACTIVE)
999 * If the event is in error state, clear that first.
1000 * That way, if we see the event in error state below, we
1001 * know that it has gone back into error state, as distinct
1002 * from the task having been scheduled away before the
1003 * cross-call arrived.
1005 if (event->state == PERF_EVENT_STATE_ERROR)
1006 event->state = PERF_EVENT_STATE_OFF;
1009 raw_spin_unlock_irq(&ctx->lock);
1010 task_oncpu_function_call(task, __perf_event_enable, event);
1012 raw_spin_lock_irq(&ctx->lock);
1015 * If the context is active and the event is still off,
1016 * we need to retry the cross-call.
1018 if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF)
1022 * Since we have the lock this context can't be scheduled
1023 * in, so we can change the state safely.
1025 if (event->state == PERF_EVENT_STATE_OFF)
1026 __perf_event_mark_enabled(event, ctx);
1029 raw_spin_unlock_irq(&ctx->lock);
1032 static int perf_event_refresh(struct perf_event *event, int refresh)
1035 * not supported on inherited events
1037 if (event->attr.inherit)
1040 atomic_add(refresh, &event->event_limit);
1041 perf_event_enable(event);
1046 void __perf_event_sched_out(struct perf_event_context *ctx,
1047 struct perf_cpu_context *cpuctx)
1049 struct perf_event *event;
1051 raw_spin_lock(&ctx->lock);
1053 if (likely(!ctx->nr_events))
1055 update_context_time(ctx);
1058 if (ctx->nr_active) {
1059 list_for_each_entry(event, &ctx->group_list, group_entry)
1060 group_sched_out(event, cpuctx, ctx);
1064 raw_spin_unlock(&ctx->lock);
1068 * Test whether two contexts are equivalent, i.e. whether they
1069 * have both been cloned from the same version of the same context
1070 * and they both have the same number of enabled events.
1071 * If the number of enabled events is the same, then the set
1072 * of enabled events should be the same, because these are both
1073 * inherited contexts, therefore we can't access individual events
1074 * in them directly with an fd; we can only enable/disable all
1075 * events via prctl, or enable/disable all events in a family
1076 * via ioctl, which will have the same effect on both contexts.
1078 static int context_equiv(struct perf_event_context *ctx1,
1079 struct perf_event_context *ctx2)
1081 return ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx
1082 && ctx1->parent_gen == ctx2->parent_gen
1083 && !ctx1->pin_count && !ctx2->pin_count;
1086 static void __perf_event_sync_stat(struct perf_event *event,
1087 struct perf_event *next_event)
1091 if (!event->attr.inherit_stat)
1095 * Update the event value, we cannot use perf_event_read()
1096 * because we're in the middle of a context switch and have IRQs
1097 * disabled, which upsets smp_call_function_single(), however
1098 * we know the event must be on the current CPU, therefore we
1099 * don't need to use it.
1101 switch (event->state) {
1102 case PERF_EVENT_STATE_ACTIVE:
1103 event->pmu->read(event);
1106 case PERF_EVENT_STATE_INACTIVE:
1107 update_event_times(event);
1115 * In order to keep per-task stats reliable we need to flip the event
1116 * values when we flip the contexts.
1118 value = atomic64_read(&next_event->count);
1119 value = atomic64_xchg(&event->count, value);
1120 atomic64_set(&next_event->count, value);
1122 swap(event->total_time_enabled, next_event->total_time_enabled);
1123 swap(event->total_time_running, next_event->total_time_running);
1126 * Since we swizzled the values, update the user visible data too.
1128 perf_event_update_userpage(event);
1129 perf_event_update_userpage(next_event);
1132 #define list_next_entry(pos, member) \
1133 list_entry(pos->member.next, typeof(*pos), member)
1135 static void perf_event_sync_stat(struct perf_event_context *ctx,
1136 struct perf_event_context *next_ctx)
1138 struct perf_event *event, *next_event;
1143 update_context_time(ctx);
1145 event = list_first_entry(&ctx->event_list,
1146 struct perf_event, event_entry);
1148 next_event = list_first_entry(&next_ctx->event_list,
1149 struct perf_event, event_entry);
1151 while (&event->event_entry != &ctx->event_list &&
1152 &next_event->event_entry != &next_ctx->event_list) {
1154 __perf_event_sync_stat(event, next_event);
1156 event = list_next_entry(event, event_entry);
1157 next_event = list_next_entry(next_event, event_entry);
1162 * Called from scheduler to remove the events of the current task,
1163 * with interrupts disabled.
1165 * We stop each event and update the event value in event->count.
1167 * This does not protect us against NMI, but disable()
1168 * sets the disabled bit in the control field of event _before_
1169 * accessing the event control register. If a NMI hits, then it will
1170 * not restart the event.
1172 void perf_event_task_sched_out(struct task_struct *task,
1173 struct task_struct *next, int cpu)
1175 struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
1176 struct perf_event_context *ctx = task->perf_event_ctxp;
1177 struct perf_event_context *next_ctx;
1178 struct perf_event_context *parent;
1179 struct pt_regs *regs;
1182 regs = task_pt_regs(task);
1183 perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0);
1185 if (likely(!ctx || !cpuctx->task_ctx))
1189 parent = rcu_dereference(ctx->parent_ctx);
1190 next_ctx = next->perf_event_ctxp;
1191 if (parent && next_ctx &&
1192 rcu_dereference(next_ctx->parent_ctx) == parent) {
1194 * Looks like the two contexts are clones, so we might be
1195 * able to optimize the context switch. We lock both
1196 * contexts and check that they are clones under the
1197 * lock (including re-checking that neither has been
1198 * uncloned in the meantime). It doesn't matter which
1199 * order we take the locks because no other cpu could
1200 * be trying to lock both of these tasks.
1202 raw_spin_lock(&ctx->lock);
1203 raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
1204 if (context_equiv(ctx, next_ctx)) {
1206 * XXX do we need a memory barrier of sorts
1207 * wrt to rcu_dereference() of perf_event_ctxp
1209 task->perf_event_ctxp = next_ctx;
1210 next->perf_event_ctxp = ctx;
1212 next_ctx->task = task;
1215 perf_event_sync_stat(ctx, next_ctx);
1217 raw_spin_unlock(&next_ctx->lock);
1218 raw_spin_unlock(&ctx->lock);
1223 __perf_event_sched_out(ctx, cpuctx);
1224 cpuctx->task_ctx = NULL;
1229 * Called with IRQs disabled
1231 static void __perf_event_task_sched_out(struct perf_event_context *ctx)
1233 struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
1235 if (!cpuctx->task_ctx)
1238 if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
1241 __perf_event_sched_out(ctx, cpuctx);
1242 cpuctx->task_ctx = NULL;
1246 * Called with IRQs disabled
1248 static void perf_event_cpu_sched_out(struct perf_cpu_context *cpuctx)
1250 __perf_event_sched_out(&cpuctx->ctx, cpuctx);
1254 __perf_event_sched_in(struct perf_event_context *ctx,
1255 struct perf_cpu_context *cpuctx, int cpu)
1257 struct perf_event *event;
1260 raw_spin_lock(&ctx->lock);
1262 if (likely(!ctx->nr_events))
1265 ctx->timestamp = perf_clock();
1270 * First go through the list and put on any pinned groups
1271 * in order to give them the best chance of going on.
1273 list_for_each_entry(event, &ctx->group_list, group_entry) {
1274 if (event->state <= PERF_EVENT_STATE_OFF ||
1275 !event->attr.pinned)
1277 if (event->cpu != -1 && event->cpu != cpu)
1280 if (group_can_go_on(event, cpuctx, 1))
1281 group_sched_in(event, cpuctx, ctx, cpu);
1284 * If this pinned group hasn't been scheduled,
1285 * put it in error state.
1287 if (event->state == PERF_EVENT_STATE_INACTIVE) {
1288 update_group_times(event);
1289 event->state = PERF_EVENT_STATE_ERROR;
1293 list_for_each_entry(event, &ctx->group_list, group_entry) {
1295 * Ignore events in OFF or ERROR state, and
1296 * ignore pinned events since we did them already.
1298 if (event->state <= PERF_EVENT_STATE_OFF ||
1303 * Listen to the 'cpu' scheduling filter constraint
1306 if (event->cpu != -1 && event->cpu != cpu)
1309 if (group_can_go_on(event, cpuctx, can_add_hw))
1310 if (group_sched_in(event, cpuctx, ctx, cpu))
1315 raw_spin_unlock(&ctx->lock);
1319 * Called from scheduler to add the events of the current task
1320 * with interrupts disabled.
1322 * We restore the event value and then enable it.
1324 * This does not protect us against NMI, but enable()
1325 * sets the enabled bit in the control field of event _before_
1326 * accessing the event control register. If a NMI hits, then it will
1327 * keep the event running.
1329 void perf_event_task_sched_in(struct task_struct *task, int cpu)
1331 struct perf_cpu_context *cpuctx = &per_cpu(perf_cpu_context, cpu);
1332 struct perf_event_context *ctx = task->perf_event_ctxp;
1336 if (cpuctx->task_ctx == ctx)
1338 __perf_event_sched_in(ctx, cpuctx, cpu);
1339 cpuctx->task_ctx = ctx;
1342 static void perf_event_cpu_sched_in(struct perf_cpu_context *cpuctx, int cpu)
1344 struct perf_event_context *ctx = &cpuctx->ctx;
1346 __perf_event_sched_in(ctx, cpuctx, cpu);
1349 #define MAX_INTERRUPTS (~0ULL)
1351 static void perf_log_throttle(struct perf_event *event, int enable);
1353 static void perf_adjust_period(struct perf_event *event, u64 events)
1355 struct hw_perf_event *hwc = &event->hw;
1356 u64 period, sample_period;
1359 events *= hwc->sample_period;
1360 period = div64_u64(events, event->attr.sample_freq);
1362 delta = (s64)(period - hwc->sample_period);
1363 delta = (delta + 7) / 8; /* low pass filter */
1365 sample_period = hwc->sample_period + delta;
1370 hwc->sample_period = sample_period;
1373 static void perf_ctx_adjust_freq(struct perf_event_context *ctx)
1375 struct perf_event *event;
1376 struct hw_perf_event *hwc;
1377 u64 interrupts, freq;
1379 raw_spin_lock(&ctx->lock);
1380 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
1381 if (event->state != PERF_EVENT_STATE_ACTIVE)
1384 if (event->cpu != -1 && event->cpu != smp_processor_id())
1389 interrupts = hwc->interrupts;
1390 hwc->interrupts = 0;
1393 * unthrottle events on the tick
1395 if (interrupts == MAX_INTERRUPTS) {
1396 perf_log_throttle(event, 1);
1397 event->pmu->unthrottle(event);
1398 interrupts = 2*sysctl_perf_event_sample_rate/HZ;
1401 if (!event->attr.freq || !event->attr.sample_freq)
1405 * if the specified freq < HZ then we need to skip ticks
1407 if (event->attr.sample_freq < HZ) {
1408 freq = event->attr.sample_freq;
1410 hwc->freq_count += freq;
1411 hwc->freq_interrupts += interrupts;
1413 if (hwc->freq_count < HZ)
1416 interrupts = hwc->freq_interrupts;
1417 hwc->freq_interrupts = 0;
1418 hwc->freq_count -= HZ;
1422 perf_adjust_period(event, freq * interrupts);
1425 * In order to avoid being stalled by an (accidental) huge
1426 * sample period, force reset the sample period if we didn't
1427 * get any events in this freq period.
1431 event->pmu->disable(event);
1432 atomic64_set(&hwc->period_left, 0);
1433 event->pmu->enable(event);
1437 raw_spin_unlock(&ctx->lock);
1441 * Round-robin a context's events:
1443 static void rotate_ctx(struct perf_event_context *ctx)
1445 struct perf_event *event;
1447 if (!ctx->nr_events)
1450 raw_spin_lock(&ctx->lock);
1452 * Rotate the first entry last (works just fine for group events too):
1455 list_for_each_entry(event, &ctx->group_list, group_entry) {
1456 list_move_tail(&event->group_entry, &ctx->group_list);
1461 raw_spin_unlock(&ctx->lock);
1464 void perf_event_task_tick(struct task_struct *curr, int cpu)
1466 struct perf_cpu_context *cpuctx;
1467 struct perf_event_context *ctx;
1469 if (!atomic_read(&nr_events))
1472 cpuctx = &per_cpu(perf_cpu_context, cpu);
1473 ctx = curr->perf_event_ctxp;
1475 perf_ctx_adjust_freq(&cpuctx->ctx);
1477 perf_ctx_adjust_freq(ctx);
1479 perf_event_cpu_sched_out(cpuctx);
1481 __perf_event_task_sched_out(ctx);
1483 rotate_ctx(&cpuctx->ctx);
1487 perf_event_cpu_sched_in(cpuctx, cpu);
1489 perf_event_task_sched_in(curr, cpu);
1493 * Enable all of a task's events that have been marked enable-on-exec.
1494 * This expects task == current.
1496 static void perf_event_enable_on_exec(struct task_struct *task)
1498 struct perf_event_context *ctx;
1499 struct perf_event *event;
1500 unsigned long flags;
1503 local_irq_save(flags);
1504 ctx = task->perf_event_ctxp;
1505 if (!ctx || !ctx->nr_events)
1508 __perf_event_task_sched_out(ctx);
1510 raw_spin_lock(&ctx->lock);
1512 list_for_each_entry(event, &ctx->group_list, group_entry) {
1513 if (!event->attr.enable_on_exec)
1515 event->attr.enable_on_exec = 0;
1516 if (event->state >= PERF_EVENT_STATE_INACTIVE)
1518 __perf_event_mark_enabled(event, ctx);
1523 * Unclone this context if we enabled any event.
1528 raw_spin_unlock(&ctx->lock);
1530 perf_event_task_sched_in(task, smp_processor_id());
1532 local_irq_restore(flags);
1536 * Cross CPU call to read the hardware event
1538 static void __perf_event_read(void *info)
1540 struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
1541 struct perf_event *event = info;
1542 struct perf_event_context *ctx = event->ctx;
1545 * If this is a task context, we need to check whether it is
1546 * the current task context of this cpu. If not it has been
1547 * scheduled out before the smp call arrived. In that case
1548 * event->count would have been updated to a recent sample
1549 * when the event was scheduled out.
1551 if (ctx->task && cpuctx->task_ctx != ctx)
1554 raw_spin_lock(&ctx->lock);
1555 update_context_time(ctx);
1556 update_event_times(event);
1557 raw_spin_unlock(&ctx->lock);
1559 event->pmu->read(event);
1562 static u64 perf_event_read(struct perf_event *event)
1565 * If event is enabled and currently active on a CPU, update the
1566 * value in the event structure:
1568 if (event->state == PERF_EVENT_STATE_ACTIVE) {
1569 smp_call_function_single(event->oncpu,
1570 __perf_event_read, event, 1);
1571 } else if (event->state == PERF_EVENT_STATE_INACTIVE) {
1572 struct perf_event_context *ctx = event->ctx;
1573 unsigned long flags;
1575 raw_spin_lock_irqsave(&ctx->lock, flags);
1576 update_context_time(ctx);
1577 update_event_times(event);
1578 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1581 return atomic64_read(&event->count);
1585 * Initialize the perf_event context in a task_struct:
1588 __perf_event_init_context(struct perf_event_context *ctx,
1589 struct task_struct *task)
1591 raw_spin_lock_init(&ctx->lock);
1592 mutex_init(&ctx->mutex);
1593 INIT_LIST_HEAD(&ctx->group_list);
1594 INIT_LIST_HEAD(&ctx->event_list);
1595 atomic_set(&ctx->refcount, 1);
1599 static struct perf_event_context *find_get_context(pid_t pid, int cpu)
1601 struct perf_event_context *ctx;
1602 struct perf_cpu_context *cpuctx;
1603 struct task_struct *task;
1604 unsigned long flags;
1607 if (pid == -1 && cpu != -1) {
1608 /* Must be root to operate on a CPU event: */
1609 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
1610 return ERR_PTR(-EACCES);
1612 if (cpu < 0 || cpu >= nr_cpumask_bits)
1613 return ERR_PTR(-EINVAL);
1616 * We could be clever and allow to attach a event to an
1617 * offline CPU and activate it when the CPU comes up, but
1620 if (!cpu_online(cpu))
1621 return ERR_PTR(-ENODEV);
1623 cpuctx = &per_cpu(perf_cpu_context, cpu);
1634 task = find_task_by_vpid(pid);
1636 get_task_struct(task);
1640 return ERR_PTR(-ESRCH);
1643 * Can't attach events to a dying task.
1646 if (task->flags & PF_EXITING)
1649 /* Reuse ptrace permission checks for now. */
1651 if (!ptrace_may_access(task, PTRACE_MODE_READ))
1655 ctx = perf_lock_task_context(task, &flags);
1658 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1662 ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
1666 __perf_event_init_context(ctx, task);
1668 if (cmpxchg(&task->perf_event_ctxp, NULL, ctx)) {
1670 * We raced with some other task; use
1671 * the context they set.
1676 get_task_struct(task);
1679 put_task_struct(task);
1683 put_task_struct(task);
1684 return ERR_PTR(err);
1687 static void perf_event_free_filter(struct perf_event *event);
1689 static void free_event_rcu(struct rcu_head *head)
1691 struct perf_event *event;
1693 event = container_of(head, struct perf_event, rcu_head);
1695 put_pid_ns(event->ns);
1696 perf_event_free_filter(event);
1700 static void perf_pending_sync(struct perf_event *event);
1702 static void free_event(struct perf_event *event)
1704 perf_pending_sync(event);
1706 if (!event->parent) {
1707 atomic_dec(&nr_events);
1708 if (event->attr.mmap)
1709 atomic_dec(&nr_mmap_events);
1710 if (event->attr.comm)
1711 atomic_dec(&nr_comm_events);
1712 if (event->attr.task)
1713 atomic_dec(&nr_task_events);
1716 if (event->output) {
1717 fput(event->output->filp);
1718 event->output = NULL;
1722 event->destroy(event);
1724 put_ctx(event->ctx);
1725 call_rcu(&event->rcu_head, free_event_rcu);
1728 int perf_event_release_kernel(struct perf_event *event)
1730 struct perf_event_context *ctx = event->ctx;
1732 WARN_ON_ONCE(ctx->parent_ctx);
1733 mutex_lock(&ctx->mutex);
1734 perf_event_remove_from_context(event);
1735 mutex_unlock(&ctx->mutex);
1737 mutex_lock(&event->owner->perf_event_mutex);
1738 list_del_init(&event->owner_entry);
1739 mutex_unlock(&event->owner->perf_event_mutex);
1740 put_task_struct(event->owner);
1746 EXPORT_SYMBOL_GPL(perf_event_release_kernel);
1749 * Called when the last reference to the file is gone.
1751 static int perf_release(struct inode *inode, struct file *file)
1753 struct perf_event *event = file->private_data;
1755 file->private_data = NULL;
1757 return perf_event_release_kernel(event);
1760 static int perf_event_read_size(struct perf_event *event)
1762 int entry = sizeof(u64); /* value */
1766 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
1767 size += sizeof(u64);
1769 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
1770 size += sizeof(u64);
1772 if (event->attr.read_format & PERF_FORMAT_ID)
1773 entry += sizeof(u64);
1775 if (event->attr.read_format & PERF_FORMAT_GROUP) {
1776 nr += event->group_leader->nr_siblings;
1777 size += sizeof(u64);
1785 u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
1787 struct perf_event *child;
1793 mutex_lock(&event->child_mutex);
1794 total += perf_event_read(event);
1795 *enabled += event->total_time_enabled +
1796 atomic64_read(&event->child_total_time_enabled);
1797 *running += event->total_time_running +
1798 atomic64_read(&event->child_total_time_running);
1800 list_for_each_entry(child, &event->child_list, child_list) {
1801 total += perf_event_read(child);
1802 *enabled += child->total_time_enabled;
1803 *running += child->total_time_running;
1805 mutex_unlock(&event->child_mutex);
1809 EXPORT_SYMBOL_GPL(perf_event_read_value);
1811 static int perf_event_read_group(struct perf_event *event,
1812 u64 read_format, char __user *buf)
1814 struct perf_event *leader = event->group_leader, *sub;
1815 int n = 0, size = 0, ret = -EFAULT;
1816 struct perf_event_context *ctx = leader->ctx;
1818 u64 count, enabled, running;
1820 mutex_lock(&ctx->mutex);
1821 count = perf_event_read_value(leader, &enabled, &running);
1823 values[n++] = 1 + leader->nr_siblings;
1824 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
1825 values[n++] = enabled;
1826 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
1827 values[n++] = running;
1828 values[n++] = count;
1829 if (read_format & PERF_FORMAT_ID)
1830 values[n++] = primary_event_id(leader);
1832 size = n * sizeof(u64);
1834 if (copy_to_user(buf, values, size))
1839 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
1842 values[n++] = perf_event_read_value(sub, &enabled, &running);
1843 if (read_format & PERF_FORMAT_ID)
1844 values[n++] = primary_event_id(sub);
1846 size = n * sizeof(u64);
1848 if (copy_to_user(buf + ret, values, size)) {
1856 mutex_unlock(&ctx->mutex);
1861 static int perf_event_read_one(struct perf_event *event,
1862 u64 read_format, char __user *buf)
1864 u64 enabled, running;
1868 values[n++] = perf_event_read_value(event, &enabled, &running);
1869 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
1870 values[n++] = enabled;
1871 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
1872 values[n++] = running;
1873 if (read_format & PERF_FORMAT_ID)
1874 values[n++] = primary_event_id(event);
1876 if (copy_to_user(buf, values, n * sizeof(u64)))
1879 return n * sizeof(u64);
1883 * Read the performance event - simple non blocking version for now
1886 perf_read_hw(struct perf_event *event, char __user *buf, size_t count)
1888 u64 read_format = event->attr.read_format;
1892 * Return end-of-file for a read on a event that is in
1893 * error state (i.e. because it was pinned but it couldn't be
1894 * scheduled on to the CPU at some point).
1896 if (event->state == PERF_EVENT_STATE_ERROR)
1899 if (count < perf_event_read_size(event))
1902 WARN_ON_ONCE(event->ctx->parent_ctx);
1903 if (read_format & PERF_FORMAT_GROUP)
1904 ret = perf_event_read_group(event, read_format, buf);
1906 ret = perf_event_read_one(event, read_format, buf);
1912 perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
1914 struct perf_event *event = file->private_data;
1916 return perf_read_hw(event, buf, count);
1919 static unsigned int perf_poll(struct file *file, poll_table *wait)
1921 struct perf_event *event = file->private_data;
1922 struct perf_mmap_data *data;
1923 unsigned int events = POLL_HUP;
1926 data = rcu_dereference(event->data);
1928 events = atomic_xchg(&data->poll, 0);
1931 poll_wait(file, &event->waitq, wait);
1936 static void perf_event_reset(struct perf_event *event)
1938 (void)perf_event_read(event);
1939 atomic64_set(&event->count, 0);
1940 perf_event_update_userpage(event);
1944 * Holding the top-level event's child_mutex means that any
1945 * descendant process that has inherited this event will block
1946 * in sync_child_event if it goes to exit, thus satisfying the
1947 * task existence requirements of perf_event_enable/disable.
1949 static void perf_event_for_each_child(struct perf_event *event,
1950 void (*func)(struct perf_event *))
1952 struct perf_event *child;
1954 WARN_ON_ONCE(event->ctx->parent_ctx);
1955 mutex_lock(&event->child_mutex);
1957 list_for_each_entry(child, &event->child_list, child_list)
1959 mutex_unlock(&event->child_mutex);
1962 static void perf_event_for_each(struct perf_event *event,
1963 void (*func)(struct perf_event *))
1965 struct perf_event_context *ctx = event->ctx;
1966 struct perf_event *sibling;
1968 WARN_ON_ONCE(ctx->parent_ctx);
1969 mutex_lock(&ctx->mutex);
1970 event = event->group_leader;
1972 perf_event_for_each_child(event, func);
1974 list_for_each_entry(sibling, &event->sibling_list, group_entry)
1975 perf_event_for_each_child(event, func);
1976 mutex_unlock(&ctx->mutex);
1979 static int perf_event_period(struct perf_event *event, u64 __user *arg)
1981 struct perf_event_context *ctx = event->ctx;
1986 if (!event->attr.sample_period)
1989 size = copy_from_user(&value, arg, sizeof(value));
1990 if (size != sizeof(value))
1996 raw_spin_lock_irq(&ctx->lock);
1997 if (event->attr.freq) {
1998 if (value > sysctl_perf_event_sample_rate) {
2003 event->attr.sample_freq = value;
2005 event->attr.sample_period = value;
2006 event->hw.sample_period = value;
2009 raw_spin_unlock_irq(&ctx->lock);
2014 static int perf_event_set_output(struct perf_event *event, int output_fd);
2015 static int perf_event_set_filter(struct perf_event *event, void __user *arg);
2017 static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2019 struct perf_event *event = file->private_data;
2020 void (*func)(struct perf_event *);
2024 case PERF_EVENT_IOC_ENABLE:
2025 func = perf_event_enable;
2027 case PERF_EVENT_IOC_DISABLE:
2028 func = perf_event_disable;
2030 case PERF_EVENT_IOC_RESET:
2031 func = perf_event_reset;
2034 case PERF_EVENT_IOC_REFRESH:
2035 return perf_event_refresh(event, arg);
2037 case PERF_EVENT_IOC_PERIOD:
2038 return perf_event_period(event, (u64 __user *)arg);
2040 case PERF_EVENT_IOC_SET_OUTPUT:
2041 return perf_event_set_output(event, arg);
2043 case PERF_EVENT_IOC_SET_FILTER:
2044 return perf_event_set_filter(event, (void __user *)arg);
2050 if (flags & PERF_IOC_FLAG_GROUP)
2051 perf_event_for_each(event, func);
2053 perf_event_for_each_child(event, func);
2058 int perf_event_task_enable(void)
2060 struct perf_event *event;
2062 mutex_lock(¤t->perf_event_mutex);
2063 list_for_each_entry(event, ¤t->perf_event_list, owner_entry)
2064 perf_event_for_each_child(event, perf_event_enable);
2065 mutex_unlock(¤t->perf_event_mutex);
2070 int perf_event_task_disable(void)
2072 struct perf_event *event;
2074 mutex_lock(¤t->perf_event_mutex);
2075 list_for_each_entry(event, ¤t->perf_event_list, owner_entry)
2076 perf_event_for_each_child(event, perf_event_disable);
2077 mutex_unlock(¤t->perf_event_mutex);
2082 #ifndef PERF_EVENT_INDEX_OFFSET
2083 # define PERF_EVENT_INDEX_OFFSET 0
2086 static int perf_event_index(struct perf_event *event)
2088 if (event->state != PERF_EVENT_STATE_ACTIVE)
2091 return event->hw.idx + 1 - PERF_EVENT_INDEX_OFFSET;
2095 * Callers need to ensure there can be no nesting of this function, otherwise
2096 * the seqlock logic goes bad. We can not serialize this because the arch
2097 * code calls this from NMI context.
2099 void perf_event_update_userpage(struct perf_event *event)
2101 struct perf_event_mmap_page *userpg;
2102 struct perf_mmap_data *data;
2105 data = rcu_dereference(event->data);
2109 userpg = data->user_page;
2112 * Disable preemption so as to not let the corresponding user-space
2113 * spin too long if we get preempted.
2118 userpg->index = perf_event_index(event);
2119 userpg->offset = atomic64_read(&event->count);
2120 if (event->state == PERF_EVENT_STATE_ACTIVE)
2121 userpg->offset -= atomic64_read(&event->hw.prev_count);
2123 userpg->time_enabled = event->total_time_enabled +
2124 atomic64_read(&event->child_total_time_enabled);
2126 userpg->time_running = event->total_time_running +
2127 atomic64_read(&event->child_total_time_running);
2136 static unsigned long perf_data_size(struct perf_mmap_data *data)
2138 return data->nr_pages << (PAGE_SHIFT + data->data_order);
2141 #ifndef CONFIG_PERF_USE_VMALLOC
2144 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
2147 static struct page *
2148 perf_mmap_to_page(struct perf_mmap_data *data, unsigned long pgoff)
2150 if (pgoff > data->nr_pages)
2154 return virt_to_page(data->user_page);
2156 return virt_to_page(data->data_pages[pgoff - 1]);
2159 static struct perf_mmap_data *
2160 perf_mmap_data_alloc(struct perf_event *event, int nr_pages)
2162 struct perf_mmap_data *data;
2166 WARN_ON(atomic_read(&event->mmap_count));
2168 size = sizeof(struct perf_mmap_data);
2169 size += nr_pages * sizeof(void *);
2171 data = kzalloc(size, GFP_KERNEL);
2175 data->user_page = (void *)get_zeroed_page(GFP_KERNEL);
2176 if (!data->user_page)
2177 goto fail_user_page;
2179 for (i = 0; i < nr_pages; i++) {
2180 data->data_pages[i] = (void *)get_zeroed_page(GFP_KERNEL);
2181 if (!data->data_pages[i])
2182 goto fail_data_pages;
2185 data->data_order = 0;
2186 data->nr_pages = nr_pages;
2191 for (i--; i >= 0; i--)
2192 free_page((unsigned long)data->data_pages[i]);
2194 free_page((unsigned long)data->user_page);
2203 static void perf_mmap_free_page(unsigned long addr)
2205 struct page *page = virt_to_page((void *)addr);
2207 page->mapping = NULL;
2211 static void perf_mmap_data_free(struct perf_mmap_data *data)
2215 perf_mmap_free_page((unsigned long)data->user_page);
2216 for (i = 0; i < data->nr_pages; i++)
2217 perf_mmap_free_page((unsigned long)data->data_pages[i]);
2224 * Back perf_mmap() with vmalloc memory.
2226 * Required for architectures that have d-cache aliasing issues.
2229 static struct page *
2230 perf_mmap_to_page(struct perf_mmap_data *data, unsigned long pgoff)
2232 if (pgoff > (1UL << data->data_order))
2235 return vmalloc_to_page((void *)data->user_page + pgoff * PAGE_SIZE);
2238 static void perf_mmap_unmark_page(void *addr)
2240 struct page *page = vmalloc_to_page(addr);
2242 page->mapping = NULL;
2245 static void perf_mmap_data_free_work(struct work_struct *work)
2247 struct perf_mmap_data *data;
2251 data = container_of(work, struct perf_mmap_data, work);
2252 nr = 1 << data->data_order;
2254 base = data->user_page;
2255 for (i = 0; i < nr + 1; i++)
2256 perf_mmap_unmark_page(base + (i * PAGE_SIZE));
2262 static void perf_mmap_data_free(struct perf_mmap_data *data)
2264 schedule_work(&data->work);
2267 static struct perf_mmap_data *
2268 perf_mmap_data_alloc(struct perf_event *event, int nr_pages)
2270 struct perf_mmap_data *data;
2274 WARN_ON(atomic_read(&event->mmap_count));
2276 size = sizeof(struct perf_mmap_data);
2277 size += sizeof(void *);
2279 data = kzalloc(size, GFP_KERNEL);
2283 INIT_WORK(&data->work, perf_mmap_data_free_work);
2285 all_buf = vmalloc_user((nr_pages + 1) * PAGE_SIZE);
2289 data->user_page = all_buf;
2290 data->data_pages[0] = all_buf + PAGE_SIZE;
2291 data->data_order = ilog2(nr_pages);
2305 static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
2307 struct perf_event *event = vma->vm_file->private_data;
2308 struct perf_mmap_data *data;
2309 int ret = VM_FAULT_SIGBUS;
2311 if (vmf->flags & FAULT_FLAG_MKWRITE) {
2312 if (vmf->pgoff == 0)
2318 data = rcu_dereference(event->data);
2322 if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
2325 vmf->page = perf_mmap_to_page(data, vmf->pgoff);
2329 get_page(vmf->page);
2330 vmf->page->mapping = vma->vm_file->f_mapping;
2331 vmf->page->index = vmf->pgoff;
2341 perf_mmap_data_init(struct perf_event *event, struct perf_mmap_data *data)
2343 long max_size = perf_data_size(data);
2345 atomic_set(&data->lock, -1);
2347 if (event->attr.watermark) {
2348 data->watermark = min_t(long, max_size,
2349 event->attr.wakeup_watermark);
2352 if (!data->watermark)
2353 data->watermark = max_size / 2;
2356 rcu_assign_pointer(event->data, data);
2359 static void perf_mmap_data_free_rcu(struct rcu_head *rcu_head)
2361 struct perf_mmap_data *data;
2363 data = container_of(rcu_head, struct perf_mmap_data, rcu_head);
2364 perf_mmap_data_free(data);
2367 static void perf_mmap_data_release(struct perf_event *event)
2369 struct perf_mmap_data *data = event->data;
2371 WARN_ON(atomic_read(&event->mmap_count));
2373 rcu_assign_pointer(event->data, NULL);
2374 call_rcu(&data->rcu_head, perf_mmap_data_free_rcu);
2377 static void perf_mmap_open(struct vm_area_struct *vma)
2379 struct perf_event *event = vma->vm_file->private_data;
2381 atomic_inc(&event->mmap_count);
2384 static void perf_mmap_close(struct vm_area_struct *vma)
2386 struct perf_event *event = vma->vm_file->private_data;
2388 WARN_ON_ONCE(event->ctx->parent_ctx);
2389 if (atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex)) {
2390 unsigned long size = perf_data_size(event->data);
2391 struct user_struct *user = current_user();
2393 atomic_long_sub((size >> PAGE_SHIFT) + 1, &user->locked_vm);
2394 vma->vm_mm->locked_vm -= event->data->nr_locked;
2395 perf_mmap_data_release(event);
2396 mutex_unlock(&event->mmap_mutex);
2400 static const struct vm_operations_struct perf_mmap_vmops = {
2401 .open = perf_mmap_open,
2402 .close = perf_mmap_close,
2403 .fault = perf_mmap_fault,
2404 .page_mkwrite = perf_mmap_fault,
2407 static int perf_mmap(struct file *file, struct vm_area_struct *vma)
2409 struct perf_event *event = file->private_data;
2410 unsigned long user_locked, user_lock_limit;
2411 struct user_struct *user = current_user();
2412 unsigned long locked, lock_limit;
2413 struct perf_mmap_data *data;
2414 unsigned long vma_size;
2415 unsigned long nr_pages;
2416 long user_extra, extra;
2419 if (!(vma->vm_flags & VM_SHARED))
2422 vma_size = vma->vm_end - vma->vm_start;
2423 nr_pages = (vma_size / PAGE_SIZE) - 1;
2426 * If we have data pages ensure they're a power-of-two number, so we
2427 * can do bitmasks instead of modulo.
2429 if (nr_pages != 0 && !is_power_of_2(nr_pages))
2432 if (vma_size != PAGE_SIZE * (1 + nr_pages))
2435 if (vma->vm_pgoff != 0)
2438 WARN_ON_ONCE(event->ctx->parent_ctx);
2439 mutex_lock(&event->mmap_mutex);
2440 if (event->output) {
2445 if (atomic_inc_not_zero(&event->mmap_count)) {
2446 if (nr_pages != event->data->nr_pages)
2451 user_extra = nr_pages + 1;
2452 user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
2455 * Increase the limit linearly with more CPUs:
2457 user_lock_limit *= num_online_cpus();
2459 user_locked = atomic_long_read(&user->locked_vm) + user_extra;
2462 if (user_locked > user_lock_limit)
2463 extra = user_locked - user_lock_limit;
2465 lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
2466 lock_limit >>= PAGE_SHIFT;
2467 locked = vma->vm_mm->locked_vm + extra;
2469 if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
2470 !capable(CAP_IPC_LOCK)) {
2475 WARN_ON(event->data);
2477 data = perf_mmap_data_alloc(event, nr_pages);
2483 perf_mmap_data_init(event, data);
2485 atomic_set(&event->mmap_count, 1);
2486 atomic_long_add(user_extra, &user->locked_vm);
2487 vma->vm_mm->locked_vm += extra;
2488 event->data->nr_locked = extra;
2489 if (vma->vm_flags & VM_WRITE)
2490 event->data->writable = 1;
2493 mutex_unlock(&event->mmap_mutex);
2495 vma->vm_flags |= VM_RESERVED;
2496 vma->vm_ops = &perf_mmap_vmops;
2501 static int perf_fasync(int fd, struct file *filp, int on)
2503 struct inode *inode = filp->f_path.dentry->d_inode;
2504 struct perf_event *event = filp->private_data;
2507 mutex_lock(&inode->i_mutex);
2508 retval = fasync_helper(fd, filp, on, &event->fasync);
2509 mutex_unlock(&inode->i_mutex);
2517 static const struct file_operations perf_fops = {
2518 .release = perf_release,
2521 .unlocked_ioctl = perf_ioctl,
2522 .compat_ioctl = perf_ioctl,
2524 .fasync = perf_fasync,
2530 * If there's data, ensure we set the poll() state and publish everything
2531 * to user-space before waking everybody up.
2534 void perf_event_wakeup(struct perf_event *event)
2536 wake_up_all(&event->waitq);
2538 if (event->pending_kill) {
2539 kill_fasync(&event->fasync, SIGIO, event->pending_kill);
2540 event->pending_kill = 0;
2547 * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
2549 * The NMI bit means we cannot possibly take locks. Therefore, maintain a
2550 * single linked list and use cmpxchg() to add entries lockless.
2553 static void perf_pending_event(struct perf_pending_entry *entry)
2555 struct perf_event *event = container_of(entry,
2556 struct perf_event, pending);
2558 if (event->pending_disable) {
2559 event->pending_disable = 0;
2560 __perf_event_disable(event);
2563 if (event->pending_wakeup) {
2564 event->pending_wakeup = 0;
2565 perf_event_wakeup(event);
2569 #define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
2571 static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = {
2575 static void perf_pending_queue(struct perf_pending_entry *entry,
2576 void (*func)(struct perf_pending_entry *))
2578 struct perf_pending_entry **head;
2580 if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL)
2585 head = &get_cpu_var(perf_pending_head);
2588 entry->next = *head;
2589 } while (cmpxchg(head, entry->next, entry) != entry->next);
2591 set_perf_event_pending();
2593 put_cpu_var(perf_pending_head);
2596 static int __perf_pending_run(void)
2598 struct perf_pending_entry *list;
2601 list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL);
2602 while (list != PENDING_TAIL) {
2603 void (*func)(struct perf_pending_entry *);
2604 struct perf_pending_entry *entry = list;
2611 * Ensure we observe the unqueue before we issue the wakeup,
2612 * so that we won't be waiting forever.
2613 * -- see perf_not_pending().
2624 static inline int perf_not_pending(struct perf_event *event)
2627 * If we flush on whatever cpu we run, there is a chance we don't
2631 __perf_pending_run();
2635 * Ensure we see the proper queue state before going to sleep
2636 * so that we do not miss the wakeup. -- see perf_pending_handle()
2639 return event->pending.next == NULL;
2642 static void perf_pending_sync(struct perf_event *event)
2644 wait_event(event->waitq, perf_not_pending(event));
2647 void perf_event_do_pending(void)
2649 __perf_pending_run();
2653 * Callchain support -- arch specific
2656 __weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
2664 static bool perf_output_space(struct perf_mmap_data *data, unsigned long tail,
2665 unsigned long offset, unsigned long head)
2669 if (!data->writable)
2672 mask = perf_data_size(data) - 1;
2674 offset = (offset - tail) & mask;
2675 head = (head - tail) & mask;
2677 if ((int)(head - offset) < 0)
2683 static void perf_output_wakeup(struct perf_output_handle *handle)
2685 atomic_set(&handle->data->poll, POLL_IN);
2688 handle->event->pending_wakeup = 1;
2689 perf_pending_queue(&handle->event->pending,
2690 perf_pending_event);
2692 perf_event_wakeup(handle->event);
2696 * Curious locking construct.
2698 * We need to ensure a later event_id doesn't publish a head when a former
2699 * event_id isn't done writing. However since we need to deal with NMIs we
2700 * cannot fully serialize things.
2702 * What we do is serialize between CPUs so we only have to deal with NMI
2703 * nesting on a single CPU.
2705 * We only publish the head (and generate a wakeup) when the outer-most
2706 * event_id completes.
2708 static void perf_output_lock(struct perf_output_handle *handle)
2710 struct perf_mmap_data *data = handle->data;
2711 int cur, cpu = get_cpu();
2716 cur = atomic_cmpxchg(&data->lock, -1, cpu);
2728 static void perf_output_unlock(struct perf_output_handle *handle)
2730 struct perf_mmap_data *data = handle->data;
2734 data->done_head = data->head;
2736 if (!handle->locked)
2741 * The xchg implies a full barrier that ensures all writes are done
2742 * before we publish the new head, matched by a rmb() in userspace when
2743 * reading this position.
2745 while ((head = atomic_long_xchg(&data->done_head, 0)))
2746 data->user_page->data_head = head;
2749 * NMI can happen here, which means we can miss a done_head update.
2752 cpu = atomic_xchg(&data->lock, -1);
2753 WARN_ON_ONCE(cpu != smp_processor_id());
2756 * Therefore we have to validate we did not indeed do so.
2758 if (unlikely(atomic_long_read(&data->done_head))) {
2760 * Since we had it locked, we can lock it again.
2762 while (atomic_cmpxchg(&data->lock, -1, cpu) != -1)
2768 if (atomic_xchg(&data->wakeup, 0))
2769 perf_output_wakeup(handle);
2774 void perf_output_copy(struct perf_output_handle *handle,
2775 const void *buf, unsigned int len)
2777 unsigned int pages_mask;
2778 unsigned long offset;
2782 offset = handle->offset;
2783 pages_mask = handle->data->nr_pages - 1;
2784 pages = handle->data->data_pages;
2787 unsigned long page_offset;
2788 unsigned long page_size;
2791 nr = (offset >> PAGE_SHIFT) & pages_mask;
2792 page_size = 1UL << (handle->data->data_order + PAGE_SHIFT);
2793 page_offset = offset & (page_size - 1);
2794 size = min_t(unsigned int, page_size - page_offset, len);
2796 memcpy(pages[nr] + page_offset, buf, size);
2803 handle->offset = offset;
2806 * Check we didn't copy past our reservation window, taking the
2807 * possible unsigned int wrap into account.
2809 WARN_ON_ONCE(((long)(handle->head - handle->offset)) < 0);
2812 int perf_output_begin(struct perf_output_handle *handle,
2813 struct perf_event *event, unsigned int size,
2814 int nmi, int sample)
2816 struct perf_event *output_event;
2817 struct perf_mmap_data *data;
2818 unsigned long tail, offset, head;
2821 struct perf_event_header header;
2828 * For inherited events we send all the output towards the parent.
2831 event = event->parent;
2833 output_event = rcu_dereference(event->output);
2835 event = output_event;
2837 data = rcu_dereference(event->data);
2841 handle->data = data;
2842 handle->event = event;
2844 handle->sample = sample;
2846 if (!data->nr_pages)
2849 have_lost = atomic_read(&data->lost);
2851 size += sizeof(lost_event);
2853 perf_output_lock(handle);
2857 * Userspace could choose to issue a mb() before updating the
2858 * tail pointer. So that all reads will be completed before the
2861 tail = ACCESS_ONCE(data->user_page->data_tail);
2863 offset = head = atomic_long_read(&data->head);
2865 if (unlikely(!perf_output_space(data, tail, offset, head)))
2867 } while (atomic_long_cmpxchg(&data->head, offset, head) != offset);
2869 handle->offset = offset;
2870 handle->head = head;
2872 if (head - tail > data->watermark)
2873 atomic_set(&data->wakeup, 1);
2876 lost_event.header.type = PERF_RECORD_LOST;
2877 lost_event.header.misc = 0;
2878 lost_event.header.size = sizeof(lost_event);
2879 lost_event.id = event->id;
2880 lost_event.lost = atomic_xchg(&data->lost, 0);
2882 perf_output_put(handle, lost_event);
2888 atomic_inc(&data->lost);
2889 perf_output_unlock(handle);
2896 void perf_output_end(struct perf_output_handle *handle)
2898 struct perf_event *event = handle->event;
2899 struct perf_mmap_data *data = handle->data;
2901 int wakeup_events = event->attr.wakeup_events;
2903 if (handle->sample && wakeup_events) {
2904 int events = atomic_inc_return(&data->events);
2905 if (events >= wakeup_events) {
2906 atomic_sub(wakeup_events, &data->events);
2907 atomic_set(&data->wakeup, 1);
2911 perf_output_unlock(handle);
2915 static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
2918 * only top level events have the pid namespace they were created in
2921 event = event->parent;
2923 return task_tgid_nr_ns(p, event->ns);
2926 static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
2929 * only top level events have the pid namespace they were created in
2932 event = event->parent;
2934 return task_pid_nr_ns(p, event->ns);
2937 static void perf_output_read_one(struct perf_output_handle *handle,
2938 struct perf_event *event)
2940 u64 read_format = event->attr.read_format;
2944 values[n++] = atomic64_read(&event->count);
2945 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
2946 values[n++] = event->total_time_enabled +
2947 atomic64_read(&event->child_total_time_enabled);
2949 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
2950 values[n++] = event->total_time_running +
2951 atomic64_read(&event->child_total_time_running);
2953 if (read_format & PERF_FORMAT_ID)
2954 values[n++] = primary_event_id(event);
2956 perf_output_copy(handle, values, n * sizeof(u64));
2960 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
2962 static void perf_output_read_group(struct perf_output_handle *handle,
2963 struct perf_event *event)
2965 struct perf_event *leader = event->group_leader, *sub;
2966 u64 read_format = event->attr.read_format;
2970 values[n++] = 1 + leader->nr_siblings;
2972 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
2973 values[n++] = leader->total_time_enabled;
2975 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
2976 values[n++] = leader->total_time_running;
2978 if (leader != event)
2979 leader->pmu->read(leader);
2981 values[n++] = atomic64_read(&leader->count);
2982 if (read_format & PERF_FORMAT_ID)
2983 values[n++] = primary_event_id(leader);
2985 perf_output_copy(handle, values, n * sizeof(u64));
2987 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
2991 sub->pmu->read(sub);
2993 values[n++] = atomic64_read(&sub->count);
2994 if (read_format & PERF_FORMAT_ID)
2995 values[n++] = primary_event_id(sub);
2997 perf_output_copy(handle, values, n * sizeof(u64));
3001 static void perf_output_read(struct perf_output_handle *handle,
3002 struct perf_event *event)
3004 if (event->attr.read_format & PERF_FORMAT_GROUP)
3005 perf_output_read_group(handle, event);
3007 perf_output_read_one(handle, event);
3010 void perf_output_sample(struct perf_output_handle *handle,
3011 struct perf_event_header *header,
3012 struct perf_sample_data *data,
3013 struct perf_event *event)
3015 u64 sample_type = data->type;
3017 perf_output_put(handle, *header);
3019 if (sample_type & PERF_SAMPLE_IP)
3020 perf_output_put(handle, data->ip);
3022 if (sample_type & PERF_SAMPLE_TID)
3023 perf_output_put(handle, data->tid_entry);
3025 if (sample_type & PERF_SAMPLE_TIME)
3026 perf_output_put(handle, data->time);
3028 if (sample_type & PERF_SAMPLE_ADDR)
3029 perf_output_put(handle, data->addr);
3031 if (sample_type & PERF_SAMPLE_ID)
3032 perf_output_put(handle, data->id);
3034 if (sample_type & PERF_SAMPLE_STREAM_ID)
3035 perf_output_put(handle, data->stream_id);
3037 if (sample_type & PERF_SAMPLE_CPU)
3038 perf_output_put(handle, data->cpu_entry);
3040 if (sample_type & PERF_SAMPLE_PERIOD)
3041 perf_output_put(handle, data->period);
3043 if (sample_type & PERF_SAMPLE_READ)
3044 perf_output_read(handle, event);
3046 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
3047 if (data->callchain) {
3050 if (data->callchain)
3051 size += data->callchain->nr;
3053 size *= sizeof(u64);
3055 perf_output_copy(handle, data->callchain, size);
3058 perf_output_put(handle, nr);
3062 if (sample_type & PERF_SAMPLE_RAW) {
3064 perf_output_put(handle, data->raw->size);
3065 perf_output_copy(handle, data->raw->data,
3072 .size = sizeof(u32),
3075 perf_output_put(handle, raw);
3080 void perf_prepare_sample(struct perf_event_header *header,
3081 struct perf_sample_data *data,
3082 struct perf_event *event,
3083 struct pt_regs *regs)
3085 u64 sample_type = event->attr.sample_type;
3087 data->type = sample_type;
3089 header->type = PERF_RECORD_SAMPLE;
3090 header->size = sizeof(*header);
3093 header->misc |= perf_misc_flags(regs);
3095 if (sample_type & PERF_SAMPLE_IP) {
3096 data->ip = perf_instruction_pointer(regs);
3098 header->size += sizeof(data->ip);
3101 if (sample_type & PERF_SAMPLE_TID) {
3102 /* namespace issues */
3103 data->tid_entry.pid = perf_event_pid(event, current);
3104 data->tid_entry.tid = perf_event_tid(event, current);
3106 header->size += sizeof(data->tid_entry);
3109 if (sample_type & PERF_SAMPLE_TIME) {
3110 data->time = perf_clock();
3112 header->size += sizeof(data->time);
3115 if (sample_type & PERF_SAMPLE_ADDR)
3116 header->size += sizeof(data->addr);
3118 if (sample_type & PERF_SAMPLE_ID) {
3119 data->id = primary_event_id(event);
3121 header->size += sizeof(data->id);
3124 if (sample_type & PERF_SAMPLE_STREAM_ID) {
3125 data->stream_id = event->id;
3127 header->size += sizeof(data->stream_id);
3130 if (sample_type & PERF_SAMPLE_CPU) {
3131 data->cpu_entry.cpu = raw_smp_processor_id();
3132 data->cpu_entry.reserved = 0;
3134 header->size += sizeof(data->cpu_entry);
3137 if (sample_type & PERF_SAMPLE_PERIOD)
3138 header->size += sizeof(data->period);
3140 if (sample_type & PERF_SAMPLE_READ)
3141 header->size += perf_event_read_size(event);
3143 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
3146 data->callchain = perf_callchain(regs);
3148 if (data->callchain)
3149 size += data->callchain->nr;
3151 header->size += size * sizeof(u64);
3154 if (sample_type & PERF_SAMPLE_RAW) {
3155 int size = sizeof(u32);
3158 size += data->raw->size;
3160 size += sizeof(u32);
3162 WARN_ON_ONCE(size & (sizeof(u64)-1));
3163 header->size += size;
3167 static void perf_event_output(struct perf_event *event, int nmi,
3168 struct perf_sample_data *data,
3169 struct pt_regs *regs)
3171 struct perf_output_handle handle;
3172 struct perf_event_header header;
3174 perf_prepare_sample(&header, data, event, regs);
3176 if (perf_output_begin(&handle, event, header.size, nmi, 1))
3179 perf_output_sample(&handle, &header, data, event);
3181 perf_output_end(&handle);
3188 struct perf_read_event {
3189 struct perf_event_header header;
3196 perf_event_read_event(struct perf_event *event,
3197 struct task_struct *task)
3199 struct perf_output_handle handle;
3200 struct perf_read_event read_event = {
3202 .type = PERF_RECORD_READ,
3204 .size = sizeof(read_event) + perf_event_read_size(event),
3206 .pid = perf_event_pid(event, task),
3207 .tid = perf_event_tid(event, task),
3211 ret = perf_output_begin(&handle, event, read_event.header.size, 0, 0);
3215 perf_output_put(&handle, read_event);
3216 perf_output_read(&handle, event);
3218 perf_output_end(&handle);
3222 * task tracking -- fork/exit
3224 * enabled by: attr.comm | attr.mmap | attr.task
3227 struct perf_task_event {
3228 struct task_struct *task;
3229 struct perf_event_context *task_ctx;
3232 struct perf_event_header header;
3242 static void perf_event_task_output(struct perf_event *event,
3243 struct perf_task_event *task_event)
3245 struct perf_output_handle handle;
3247 struct task_struct *task = task_event->task;
3250 size = task_event->event_id.header.size;
3251 ret = perf_output_begin(&handle, event, size, 0, 0);
3256 task_event->event_id.pid = perf_event_pid(event, task);
3257 task_event->event_id.ppid = perf_event_pid(event, current);
3259 task_event->event_id.tid = perf_event_tid(event, task);
3260 task_event->event_id.ptid = perf_event_tid(event, current);
3262 task_event->event_id.time = perf_clock();
3264 perf_output_put(&handle, task_event->event_id);
3266 perf_output_end(&handle);
3269 static int perf_event_task_match(struct perf_event *event)
3271 if (event->cpu != -1 && event->cpu != smp_processor_id())
3274 if (event->attr.comm || event->attr.mmap || event->attr.task)
3280 static void perf_event_task_ctx(struct perf_event_context *ctx,
3281 struct perf_task_event *task_event)
3283 struct perf_event *event;
3285 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
3286 if (perf_event_task_match(event))
3287 perf_event_task_output(event, task_event);
3291 static void perf_event_task_event(struct perf_task_event *task_event)
3293 struct perf_cpu_context *cpuctx;
3294 struct perf_event_context *ctx = task_event->task_ctx;
3297 cpuctx = &get_cpu_var(perf_cpu_context);
3298 perf_event_task_ctx(&cpuctx->ctx, task_event);
3300 ctx = rcu_dereference(task_event->task->perf_event_ctxp);
3302 perf_event_task_ctx(ctx, task_event);
3303 put_cpu_var(perf_cpu_context);
3307 static void perf_event_task(struct task_struct *task,
3308 struct perf_event_context *task_ctx,
3311 struct perf_task_event task_event;
3313 if (!atomic_read(&nr_comm_events) &&
3314 !atomic_read(&nr_mmap_events) &&
3315 !atomic_read(&nr_task_events))
3318 task_event = (struct perf_task_event){
3320 .task_ctx = task_ctx,
3323 .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
3325 .size = sizeof(task_event.event_id),
3334 perf_event_task_event(&task_event);
3337 void perf_event_fork(struct task_struct *task)
3339 perf_event_task(task, NULL, 1);
3346 struct perf_comm_event {
3347 struct task_struct *task;
3352 struct perf_event_header header;
3359 static void perf_event_comm_output(struct perf_event *event,
3360 struct perf_comm_event *comm_event)
3362 struct perf_output_handle handle;
3363 int size = comm_event->event_id.header.size;
3364 int ret = perf_output_begin(&handle, event, size, 0, 0);
3369 comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
3370 comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
3372 perf_output_put(&handle, comm_event->event_id);
3373 perf_output_copy(&handle, comm_event->comm,
3374 comm_event->comm_size);
3375 perf_output_end(&handle);
3378 static int perf_event_comm_match(struct perf_event *event)
3380 if (event->cpu != -1 && event->cpu != smp_processor_id())
3383 if (event->attr.comm)
3389 static void perf_event_comm_ctx(struct perf_event_context *ctx,
3390 struct perf_comm_event *comm_event)
3392 struct perf_event *event;
3394 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
3395 if (perf_event_comm_match(event))
3396 perf_event_comm_output(event, comm_event);
3400 static void perf_event_comm_event(struct perf_comm_event *comm_event)
3402 struct perf_cpu_context *cpuctx;
3403 struct perf_event_context *ctx;
3405 char comm[TASK_COMM_LEN];
3407 memset(comm, 0, sizeof(comm));
3408 strlcpy(comm, comm_event->task->comm, sizeof(comm));
3409 size = ALIGN(strlen(comm)+1, sizeof(u64));
3411 comm_event->comm = comm;
3412 comm_event->comm_size = size;
3414 comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
3417 cpuctx = &get_cpu_var(perf_cpu_context);
3418 perf_event_comm_ctx(&cpuctx->ctx, comm_event);
3419 ctx = rcu_dereference(current->perf_event_ctxp);
3421 perf_event_comm_ctx(ctx, comm_event);
3422 put_cpu_var(perf_cpu_context);
3426 void perf_event_comm(struct task_struct *task)
3428 struct perf_comm_event comm_event;
3430 if (task->perf_event_ctxp)
3431 perf_event_enable_on_exec(task);
3433 if (!atomic_read(&nr_comm_events))
3436 comm_event = (struct perf_comm_event){
3442 .type = PERF_RECORD_COMM,
3451 perf_event_comm_event(&comm_event);