2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
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/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
49 #include <linux/sched/clock.h>
50 #include <linux/sched/mm.h>
51 #include <linux/proc_ns.h>
52 #include <linux/mount.h>
56 #include <asm/irq_regs.h>
58 typedef int (*remote_function_f)(void *);
60 struct remote_function_call {
61 struct task_struct *p;
62 remote_function_f func;
67 static void remote_function(void *data)
69 struct remote_function_call *tfc = data;
70 struct task_struct *p = tfc->p;
74 if (task_cpu(p) != smp_processor_id())
78 * Now that we're on right CPU with IRQs disabled, we can test
79 * if we hit the right task without races.
82 tfc->ret = -ESRCH; /* No such (running) process */
87 tfc->ret = tfc->func(tfc->info);
91 * task_function_call - call a function on the cpu on which a task runs
92 * @p: the task to evaluate
93 * @func: the function to be called
94 * @info: the function call argument
96 * Calls the function @func when the task is currently running. This might
97 * be on the current CPU, which just calls the function directly. This will
98 * retry due to any failures in smp_call_function_single(), such as if the
99 * task_cpu() goes offline concurrently.
101 * returns @func return value or -ESRCH or -ENXIO when the process isn't running
104 task_function_call(struct task_struct *p, remote_function_f func, void *info)
106 struct remote_function_call data = {
115 ret = smp_call_function_single(task_cpu(p), remote_function,
130 * cpu_function_call - call a function on the cpu
131 * @func: the function to be called
132 * @info: the function call argument
134 * Calls the function @func on the remote cpu.
136 * returns: @func return value or -ENXIO when the cpu is offline
138 static int cpu_function_call(int cpu, remote_function_f func, void *info)
140 struct remote_function_call data = {
144 .ret = -ENXIO, /* No such CPU */
147 smp_call_function_single(cpu, remote_function, &data, 1);
152 static inline struct perf_cpu_context *
153 __get_cpu_context(struct perf_event_context *ctx)
155 return this_cpu_ptr(ctx->pmu->pmu_cpu_context);
158 static void perf_ctx_lock(struct perf_cpu_context *cpuctx,
159 struct perf_event_context *ctx)
161 raw_spin_lock(&cpuctx->ctx.lock);
163 raw_spin_lock(&ctx->lock);
166 static void perf_ctx_unlock(struct perf_cpu_context *cpuctx,
167 struct perf_event_context *ctx)
170 raw_spin_unlock(&ctx->lock);
171 raw_spin_unlock(&cpuctx->ctx.lock);
174 #define TASK_TOMBSTONE ((void *)-1L)
176 static bool is_kernel_event(struct perf_event *event)
178 return READ_ONCE(event->owner) == TASK_TOMBSTONE;
182 * On task ctx scheduling...
184 * When !ctx->nr_events a task context will not be scheduled. This means
185 * we can disable the scheduler hooks (for performance) without leaving
186 * pending task ctx state.
188 * This however results in two special cases:
190 * - removing the last event from a task ctx; this is relatively straight
191 * forward and is done in __perf_remove_from_context.
193 * - adding the first event to a task ctx; this is tricky because we cannot
194 * rely on ctx->is_active and therefore cannot use event_function_call().
195 * See perf_install_in_context().
197 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
200 typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *,
201 struct perf_event_context *, void *);
203 struct event_function_struct {
204 struct perf_event *event;
209 static int event_function(void *info)
211 struct event_function_struct *efs = info;
212 struct perf_event *event = efs->event;
213 struct perf_event_context *ctx = event->ctx;
214 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
215 struct perf_event_context *task_ctx = cpuctx->task_ctx;
218 WARN_ON_ONCE(!irqs_disabled());
220 perf_ctx_lock(cpuctx, task_ctx);
222 * Since we do the IPI call without holding ctx->lock things can have
223 * changed, double check we hit the task we set out to hit.
226 if (ctx->task != current) {
232 * We only use event_function_call() on established contexts,
233 * and event_function() is only ever called when active (or
234 * rather, we'll have bailed in task_function_call() or the
235 * above ctx->task != current test), therefore we must have
236 * ctx->is_active here.
238 WARN_ON_ONCE(!ctx->is_active);
240 * And since we have ctx->is_active, cpuctx->task_ctx must
243 WARN_ON_ONCE(task_ctx != ctx);
245 WARN_ON_ONCE(&cpuctx->ctx != ctx);
248 efs->func(event, cpuctx, ctx, efs->data);
250 perf_ctx_unlock(cpuctx, task_ctx);
255 static void event_function_call(struct perf_event *event, event_f func, void *data)
257 struct perf_event_context *ctx = event->ctx;
258 struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */
259 struct event_function_struct efs = {
265 if (!event->parent) {
267 * If this is a !child event, we must hold ctx::mutex to
268 * stabilize the the event->ctx relation. See
269 * perf_event_ctx_lock().
271 lockdep_assert_held(&ctx->mutex);
275 cpu_function_call(event->cpu, event_function, &efs);
279 if (task == TASK_TOMBSTONE)
283 if (!task_function_call(task, event_function, &efs))
286 raw_spin_lock_irq(&ctx->lock);
288 * Reload the task pointer, it might have been changed by
289 * a concurrent perf_event_context_sched_out().
292 if (task == TASK_TOMBSTONE) {
293 raw_spin_unlock_irq(&ctx->lock);
296 if (ctx->is_active) {
297 raw_spin_unlock_irq(&ctx->lock);
300 func(event, NULL, ctx, data);
301 raw_spin_unlock_irq(&ctx->lock);
305 * Similar to event_function_call() + event_function(), but hard assumes IRQs
306 * are already disabled and we're on the right CPU.
308 static void event_function_local(struct perf_event *event, event_f func, void *data)
310 struct perf_event_context *ctx = event->ctx;
311 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
312 struct task_struct *task = READ_ONCE(ctx->task);
313 struct perf_event_context *task_ctx = NULL;
315 WARN_ON_ONCE(!irqs_disabled());
318 if (task == TASK_TOMBSTONE)
324 perf_ctx_lock(cpuctx, task_ctx);
327 if (task == TASK_TOMBSTONE)
332 * We must be either inactive or active and the right task,
333 * otherwise we're screwed, since we cannot IPI to somewhere
336 if (ctx->is_active) {
337 if (WARN_ON_ONCE(task != current))
340 if (WARN_ON_ONCE(cpuctx->task_ctx != ctx))
344 WARN_ON_ONCE(&cpuctx->ctx != ctx);
347 func(event, cpuctx, ctx, data);
349 perf_ctx_unlock(cpuctx, task_ctx);
352 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
353 PERF_FLAG_FD_OUTPUT |\
354 PERF_FLAG_PID_CGROUP |\
355 PERF_FLAG_FD_CLOEXEC)
358 * branch priv levels that need permission checks
360 #define PERF_SAMPLE_BRANCH_PERM_PLM \
361 (PERF_SAMPLE_BRANCH_KERNEL |\
362 PERF_SAMPLE_BRANCH_HV)
365 EVENT_FLEXIBLE = 0x1,
368 /* see ctx_resched() for details */
370 EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
374 * perf_sched_events : >0 events exist
375 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
378 static void perf_sched_delayed(struct work_struct *work);
379 DEFINE_STATIC_KEY_FALSE(perf_sched_events);
380 static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed);
381 static DEFINE_MUTEX(perf_sched_mutex);
382 static atomic_t perf_sched_count;
384 static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
385 static DEFINE_PER_CPU(int, perf_sched_cb_usages);
386 static DEFINE_PER_CPU(struct pmu_event_list, pmu_sb_events);
388 static atomic_t nr_mmap_events __read_mostly;
389 static atomic_t nr_comm_events __read_mostly;
390 static atomic_t nr_namespaces_events __read_mostly;
391 static atomic_t nr_task_events __read_mostly;
392 static atomic_t nr_freq_events __read_mostly;
393 static atomic_t nr_switch_events __read_mostly;
395 static LIST_HEAD(pmus);
396 static DEFINE_MUTEX(pmus_lock);
397 static struct srcu_struct pmus_srcu;
398 static cpumask_var_t perf_online_mask;
401 * perf event paranoia level:
402 * -1 - not paranoid at all
403 * 0 - disallow raw tracepoint access for unpriv
404 * 1 - disallow cpu events for unpriv
405 * 2 - disallow kernel profiling for unpriv
407 int sysctl_perf_event_paranoid __read_mostly = 2;
409 /* Minimum for 512 kiB + 1 user control page */
410 int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */
413 * max perf event sample rate
415 #define DEFAULT_MAX_SAMPLE_RATE 100000
416 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
417 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
419 int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE;
421 static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ);
422 static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS;
424 static int perf_sample_allowed_ns __read_mostly =
425 DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100;
427 static void update_perf_cpu_limits(void)
429 u64 tmp = perf_sample_period_ns;
431 tmp *= sysctl_perf_cpu_time_max_percent;
432 tmp = div_u64(tmp, 100);
436 WRITE_ONCE(perf_sample_allowed_ns, tmp);
439 static int perf_rotate_context(struct perf_cpu_context *cpuctx);
441 int perf_proc_update_handler(struct ctl_table *table, int write,
442 void __user *buffer, size_t *lenp,
446 int perf_cpu = sysctl_perf_cpu_time_max_percent;
448 * If throttling is disabled don't allow the write:
450 if (write && (perf_cpu == 100 || perf_cpu == 0))
453 ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
457 max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ);
458 perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
459 update_perf_cpu_limits();
464 int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;
466 int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
467 void __user *buffer, size_t *lenp,
470 int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
475 if (sysctl_perf_cpu_time_max_percent == 100 ||
476 sysctl_perf_cpu_time_max_percent == 0) {
478 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
479 WRITE_ONCE(perf_sample_allowed_ns, 0);
481 update_perf_cpu_limits();
488 * perf samples are done in some very critical code paths (NMIs).
489 * If they take too much CPU time, the system can lock up and not
490 * get any real work done. This will drop the sample rate when
491 * we detect that events are taking too long.
493 #define NR_ACCUMULATED_SAMPLES 128
494 static DEFINE_PER_CPU(u64, running_sample_length);
496 static u64 __report_avg;
497 static u64 __report_allowed;
499 static void perf_duration_warn(struct irq_work *w)
501 printk_ratelimited(KERN_INFO
502 "perf: interrupt took too long (%lld > %lld), lowering "
503 "kernel.perf_event_max_sample_rate to %d\n",
504 __report_avg, __report_allowed,
505 sysctl_perf_event_sample_rate);
508 static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn);
510 void perf_sample_event_took(u64 sample_len_ns)
512 u64 max_len = READ_ONCE(perf_sample_allowed_ns);
520 /* Decay the counter by 1 average sample. */
521 running_len = __this_cpu_read(running_sample_length);
522 running_len -= running_len/NR_ACCUMULATED_SAMPLES;
523 running_len += sample_len_ns;
524 __this_cpu_write(running_sample_length, running_len);
527 * Note: this will be biased artifically low until we have
528 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
529 * from having to maintain a count.
531 avg_len = running_len/NR_ACCUMULATED_SAMPLES;
532 if (avg_len <= max_len)
535 __report_avg = avg_len;
536 __report_allowed = max_len;
539 * Compute a throttle threshold 25% below the current duration.
541 avg_len += avg_len / 4;
542 max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent;
548 WRITE_ONCE(perf_sample_allowed_ns, avg_len);
549 WRITE_ONCE(max_samples_per_tick, max);
551 sysctl_perf_event_sample_rate = max * HZ;
552 perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
554 if (!irq_work_queue(&perf_duration_work)) {
555 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
556 "kernel.perf_event_max_sample_rate to %d\n",
557 __report_avg, __report_allowed,
558 sysctl_perf_event_sample_rate);
562 static atomic64_t perf_event_id;
564 static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
565 enum event_type_t event_type);
567 static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
568 enum event_type_t event_type,
569 struct task_struct *task);
571 static void update_context_time(struct perf_event_context *ctx);
572 static u64 perf_event_time(struct perf_event *event);
574 void __weak perf_event_print_debug(void) { }
576 extern __weak const char *perf_pmu_name(void)
581 static inline u64 perf_clock(void)
583 return local_clock();
586 static inline u64 perf_event_clock(struct perf_event *event)
588 return event->clock();
591 #ifdef CONFIG_CGROUP_PERF
594 perf_cgroup_match(struct perf_event *event)
596 struct perf_event_context *ctx = event->ctx;
597 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
599 /* @event doesn't care about cgroup */
603 /* wants specific cgroup scope but @cpuctx isn't associated with any */
608 * Cgroup scoping is recursive. An event enabled for a cgroup is
609 * also enabled for all its descendant cgroups. If @cpuctx's
610 * cgroup is a descendant of @event's (the test covers identity
611 * case), it's a match.
613 return cgroup_is_descendant(cpuctx->cgrp->css.cgroup,
614 event->cgrp->css.cgroup);
617 static inline void perf_detach_cgroup(struct perf_event *event)
619 css_put(&event->cgrp->css);
623 static inline int is_cgroup_event(struct perf_event *event)
625 return event->cgrp != NULL;
628 static inline u64 perf_cgroup_event_time(struct perf_event *event)
630 struct perf_cgroup_info *t;
632 t = per_cpu_ptr(event->cgrp->info, event->cpu);
636 static inline void __update_cgrp_time(struct perf_cgroup *cgrp)
638 struct perf_cgroup_info *info;
643 info = this_cpu_ptr(cgrp->info);
645 info->time += now - info->timestamp;
646 info->timestamp = now;
649 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
651 struct perf_cgroup *cgrp = cpuctx->cgrp;
652 struct cgroup_subsys_state *css;
655 for (css = &cgrp->css; css; css = css->parent) {
656 cgrp = container_of(css, struct perf_cgroup, css);
657 __update_cgrp_time(cgrp);
662 static inline void update_cgrp_time_from_event(struct perf_event *event)
664 struct perf_cgroup *cgrp;
667 * ensure we access cgroup data only when needed and
668 * when we know the cgroup is pinned (css_get)
670 if (!is_cgroup_event(event))
673 cgrp = perf_cgroup_from_task(current, event->ctx);
675 * Do not update time when cgroup is not active
677 if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup))
678 __update_cgrp_time(event->cgrp);
682 perf_cgroup_set_timestamp(struct task_struct *task,
683 struct perf_event_context *ctx)
685 struct perf_cgroup *cgrp;
686 struct perf_cgroup_info *info;
687 struct cgroup_subsys_state *css;
690 * ctx->lock held by caller
691 * ensure we do not access cgroup data
692 * unless we have the cgroup pinned (css_get)
694 if (!task || !ctx->nr_cgroups)
697 cgrp = perf_cgroup_from_task(task, ctx);
699 for (css = &cgrp->css; css; css = css->parent) {
700 cgrp = container_of(css, struct perf_cgroup, css);
701 info = this_cpu_ptr(cgrp->info);
702 info->timestamp = ctx->timestamp;
706 static DEFINE_PER_CPU(struct list_head, cgrp_cpuctx_list);
708 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
709 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
712 * reschedule events based on the cgroup constraint of task.
714 * mode SWOUT : schedule out everything
715 * mode SWIN : schedule in based on cgroup for next
717 static void perf_cgroup_switch(struct task_struct *task, int mode)
719 struct perf_cpu_context *cpuctx;
720 struct list_head *list;
724 * Disable interrupts and preemption to avoid this CPU's
725 * cgrp_cpuctx_entry to change under us.
727 local_irq_save(flags);
729 list = this_cpu_ptr(&cgrp_cpuctx_list);
730 list_for_each_entry(cpuctx, list, cgrp_cpuctx_entry) {
731 WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0);
733 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
734 perf_pmu_disable(cpuctx->ctx.pmu);
736 if (mode & PERF_CGROUP_SWOUT) {
737 cpu_ctx_sched_out(cpuctx, EVENT_ALL);
739 * must not be done before ctxswout due
740 * to event_filter_match() in event_sched_out()
745 if (mode & PERF_CGROUP_SWIN) {
746 WARN_ON_ONCE(cpuctx->cgrp);
748 * set cgrp before ctxsw in to allow
749 * event_filter_match() to not have to pass
751 * we pass the cpuctx->ctx to perf_cgroup_from_task()
752 * because cgorup events are only per-cpu
754 cpuctx->cgrp = perf_cgroup_from_task(task,
756 cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
758 perf_pmu_enable(cpuctx->ctx.pmu);
759 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
762 local_irq_restore(flags);
765 static inline void perf_cgroup_sched_out(struct task_struct *task,
766 struct task_struct *next)
768 struct perf_cgroup *cgrp1;
769 struct perf_cgroup *cgrp2 = NULL;
773 * we come here when we know perf_cgroup_events > 0
774 * we do not need to pass the ctx here because we know
775 * we are holding the rcu lock
777 cgrp1 = perf_cgroup_from_task(task, NULL);
778 cgrp2 = perf_cgroup_from_task(next, NULL);
781 * only schedule out current cgroup events if we know
782 * that we are switching to a different cgroup. Otherwise,
783 * do no touch the cgroup events.
786 perf_cgroup_switch(task, PERF_CGROUP_SWOUT);
791 static inline void perf_cgroup_sched_in(struct task_struct *prev,
792 struct task_struct *task)
794 struct perf_cgroup *cgrp1;
795 struct perf_cgroup *cgrp2 = NULL;
799 * we come here when we know perf_cgroup_events > 0
800 * we do not need to pass the ctx here because we know
801 * we are holding the rcu lock
803 cgrp1 = perf_cgroup_from_task(task, NULL);
804 cgrp2 = perf_cgroup_from_task(prev, NULL);
807 * only need to schedule in cgroup events if we are changing
808 * cgroup during ctxsw. Cgroup events were not scheduled
809 * out of ctxsw out if that was not the case.
812 perf_cgroup_switch(task, PERF_CGROUP_SWIN);
817 static inline int perf_cgroup_connect(int fd, struct perf_event *event,
818 struct perf_event_attr *attr,
819 struct perf_event *group_leader)
821 struct perf_cgroup *cgrp;
822 struct cgroup_subsys_state *css;
823 struct fd f = fdget(fd);
829 css = css_tryget_online_from_dir(f.file->f_path.dentry,
830 &perf_event_cgrp_subsys);
836 cgrp = container_of(css, struct perf_cgroup, css);
840 * all events in a group must monitor
841 * the same cgroup because a task belongs
842 * to only one perf cgroup at a time
844 if (group_leader && group_leader->cgrp != cgrp) {
845 perf_detach_cgroup(event);
854 perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
856 struct perf_cgroup_info *t;
857 t = per_cpu_ptr(event->cgrp->info, event->cpu);
858 event->shadow_ctx_time = now - t->timestamp;
862 perf_cgroup_defer_enabled(struct perf_event *event)
865 * when the current task's perf cgroup does not match
866 * the event's, we need to remember to call the
867 * perf_mark_enable() function the first time a task with
868 * a matching perf cgroup is scheduled in.
870 if (is_cgroup_event(event) && !perf_cgroup_match(event))
871 event->cgrp_defer_enabled = 1;
875 perf_cgroup_mark_enabled(struct perf_event *event,
876 struct perf_event_context *ctx)
878 struct perf_event *sub;
879 u64 tstamp = perf_event_time(event);
881 if (!event->cgrp_defer_enabled)
884 event->cgrp_defer_enabled = 0;
886 event->tstamp_enabled = tstamp - event->total_time_enabled;
887 list_for_each_entry(sub, &event->sibling_list, group_entry) {
888 if (sub->state >= PERF_EVENT_STATE_INACTIVE) {
889 sub->tstamp_enabled = tstamp - sub->total_time_enabled;
890 sub->cgrp_defer_enabled = 0;
896 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
897 * cleared when last cgroup event is removed.
900 list_update_cgroup_event(struct perf_event *event,
901 struct perf_event_context *ctx, bool add)
903 struct perf_cpu_context *cpuctx;
904 struct list_head *cpuctx_entry;
906 if (!is_cgroup_event(event))
910 * Because cgroup events are always per-cpu events,
911 * this will always be called from the right CPU.
913 cpuctx = __get_cpu_context(ctx);
916 * Since setting cpuctx->cgrp is conditional on the current @cgrp
917 * matching the event's cgroup, we must do this for every new event,
918 * because if the first would mismatch, the second would not try again
919 * and we would leave cpuctx->cgrp unset.
921 if (add && !cpuctx->cgrp) {
922 struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx);
924 if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup))
928 if (add && ctx->nr_cgroups++)
930 else if (!add && --ctx->nr_cgroups)
933 /* no cgroup running */
937 cpuctx_entry = &cpuctx->cgrp_cpuctx_entry;
939 list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list));
941 list_del(cpuctx_entry);
944 #else /* !CONFIG_CGROUP_PERF */
947 perf_cgroup_match(struct perf_event *event)
952 static inline void perf_detach_cgroup(struct perf_event *event)
955 static inline int is_cgroup_event(struct perf_event *event)
960 static inline void update_cgrp_time_from_event(struct perf_event *event)
964 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
968 static inline void perf_cgroup_sched_out(struct task_struct *task,
969 struct task_struct *next)
973 static inline void perf_cgroup_sched_in(struct task_struct *prev,
974 struct task_struct *task)
978 static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event,
979 struct perf_event_attr *attr,
980 struct perf_event *group_leader)
986 perf_cgroup_set_timestamp(struct task_struct *task,
987 struct perf_event_context *ctx)
992 perf_cgroup_switch(struct task_struct *task, struct task_struct *next)
997 perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
1001 static inline u64 perf_cgroup_event_time(struct perf_event *event)
1007 perf_cgroup_defer_enabled(struct perf_event *event)
1012 perf_cgroup_mark_enabled(struct perf_event *event,
1013 struct perf_event_context *ctx)
1018 list_update_cgroup_event(struct perf_event *event,
1019 struct perf_event_context *ctx, bool add)
1026 * set default to be dependent on timer tick just
1027 * like original code
1029 #define PERF_CPU_HRTIMER (1000 / HZ)
1031 * function must be called with interrupts disabled
1033 static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr)
1035 struct perf_cpu_context *cpuctx;
1038 WARN_ON(!irqs_disabled());
1040 cpuctx = container_of(hr, struct perf_cpu_context, hrtimer);
1041 rotations = perf_rotate_context(cpuctx);
1043 raw_spin_lock(&cpuctx->hrtimer_lock);
1045 hrtimer_forward_now(hr, cpuctx->hrtimer_interval);
1047 cpuctx->hrtimer_active = 0;
1048 raw_spin_unlock(&cpuctx->hrtimer_lock);
1050 return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART;
1053 static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu)
1055 struct hrtimer *timer = &cpuctx->hrtimer;
1056 struct pmu *pmu = cpuctx->ctx.pmu;
1059 /* no multiplexing needed for SW PMU */
1060 if (pmu->task_ctx_nr == perf_sw_context)
1064 * check default is sane, if not set then force to
1065 * default interval (1/tick)
1067 interval = pmu->hrtimer_interval_ms;
1069 interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER;
1071 cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
1073 raw_spin_lock_init(&cpuctx->hrtimer_lock);
1074 hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
1075 timer->function = perf_mux_hrtimer_handler;
1078 static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx)
1080 struct hrtimer *timer = &cpuctx->hrtimer;
1081 struct pmu *pmu = cpuctx->ctx.pmu;
1082 unsigned long flags;
1084 /* not for SW PMU */
1085 if (pmu->task_ctx_nr == perf_sw_context)
1088 raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags);
1089 if (!cpuctx->hrtimer_active) {
1090 cpuctx->hrtimer_active = 1;
1091 hrtimer_forward_now(timer, cpuctx->hrtimer_interval);
1092 hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
1094 raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags);
1099 void perf_pmu_disable(struct pmu *pmu)
1101 int *count = this_cpu_ptr(pmu->pmu_disable_count);
1103 pmu->pmu_disable(pmu);
1106 void perf_pmu_enable(struct pmu *pmu)
1108 int *count = this_cpu_ptr(pmu->pmu_disable_count);
1110 pmu->pmu_enable(pmu);
1113 static DEFINE_PER_CPU(struct list_head, active_ctx_list);
1116 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1117 * perf_event_task_tick() are fully serialized because they're strictly cpu
1118 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1119 * disabled, while perf_event_task_tick is called from IRQ context.
1121 static void perf_event_ctx_activate(struct perf_event_context *ctx)
1123 struct list_head *head = this_cpu_ptr(&active_ctx_list);
1125 WARN_ON(!irqs_disabled());
1127 WARN_ON(!list_empty(&ctx->active_ctx_list));
1129 list_add(&ctx->active_ctx_list, head);
1132 static void perf_event_ctx_deactivate(struct perf_event_context *ctx)
1134 WARN_ON(!irqs_disabled());
1136 WARN_ON(list_empty(&ctx->active_ctx_list));
1138 list_del_init(&ctx->active_ctx_list);
1141 static void get_ctx(struct perf_event_context *ctx)
1143 WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
1146 static void free_ctx(struct rcu_head *head)
1148 struct perf_event_context *ctx;
1150 ctx = container_of(head, struct perf_event_context, rcu_head);
1151 kfree(ctx->task_ctx_data);
1155 static void put_ctx(struct perf_event_context *ctx)
1157 if (atomic_dec_and_test(&ctx->refcount)) {
1158 if (ctx->parent_ctx)
1159 put_ctx(ctx->parent_ctx);
1160 if (ctx->task && ctx->task != TASK_TOMBSTONE)
1161 put_task_struct(ctx->task);
1162 call_rcu(&ctx->rcu_head, free_ctx);
1167 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1168 * perf_pmu_migrate_context() we need some magic.
1170 * Those places that change perf_event::ctx will hold both
1171 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1173 * Lock ordering is by mutex address. There are two other sites where
1174 * perf_event_context::mutex nests and those are:
1176 * - perf_event_exit_task_context() [ child , 0 ]
1177 * perf_event_exit_event()
1178 * put_event() [ parent, 1 ]
1180 * - perf_event_init_context() [ parent, 0 ]
1181 * inherit_task_group()
1184 * perf_event_alloc()
1186 * perf_try_init_event() [ child , 1 ]
1188 * While it appears there is an obvious deadlock here -- the parent and child
1189 * nesting levels are inverted between the two. This is in fact safe because
1190 * life-time rules separate them. That is an exiting task cannot fork, and a
1191 * spawning task cannot (yet) exit.
1193 * But remember that that these are parent<->child context relations, and
1194 * migration does not affect children, therefore these two orderings should not
1197 * The change in perf_event::ctx does not affect children (as claimed above)
1198 * because the sys_perf_event_open() case will install a new event and break
1199 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1200 * concerned with cpuctx and that doesn't have children.
1202 * The places that change perf_event::ctx will issue:
1204 * perf_remove_from_context();
1205 * synchronize_rcu();
1206 * perf_install_in_context();
1208 * to affect the change. The remove_from_context() + synchronize_rcu() should
1209 * quiesce the event, after which we can install it in the new location. This
1210 * means that only external vectors (perf_fops, prctl) can perturb the event
1211 * while in transit. Therefore all such accessors should also acquire
1212 * perf_event_context::mutex to serialize against this.
1214 * However; because event->ctx can change while we're waiting to acquire
1215 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1220 * task_struct::perf_event_mutex
1221 * perf_event_context::mutex
1222 * perf_event::child_mutex;
1223 * perf_event_context::lock
1224 * perf_event::mmap_mutex
1227 static struct perf_event_context *
1228 perf_event_ctx_lock_nested(struct perf_event *event, int nesting)
1230 struct perf_event_context *ctx;
1234 ctx = ACCESS_ONCE(event->ctx);
1235 if (!atomic_inc_not_zero(&ctx->refcount)) {
1241 mutex_lock_nested(&ctx->mutex, nesting);
1242 if (event->ctx != ctx) {
1243 mutex_unlock(&ctx->mutex);
1251 static inline struct perf_event_context *
1252 perf_event_ctx_lock(struct perf_event *event)
1254 return perf_event_ctx_lock_nested(event, 0);
1257 static void perf_event_ctx_unlock(struct perf_event *event,
1258 struct perf_event_context *ctx)
1260 mutex_unlock(&ctx->mutex);
1265 * This must be done under the ctx->lock, such as to serialize against
1266 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1267 * calling scheduler related locks and ctx->lock nests inside those.
1269 static __must_check struct perf_event_context *
1270 unclone_ctx(struct perf_event_context *ctx)
1272 struct perf_event_context *parent_ctx = ctx->parent_ctx;
1274 lockdep_assert_held(&ctx->lock);
1277 ctx->parent_ctx = NULL;
1283 static u32 perf_event_pid_type(struct perf_event *event, struct task_struct *p,
1288 * only top level events have the pid namespace they were created in
1291 event = event->parent;
1293 nr = __task_pid_nr_ns(p, type, event->ns);
1294 /* avoid -1 if it is idle thread or runs in another ns */
1295 if (!nr && !pid_alive(p))
1300 static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
1302 return perf_event_pid_type(event, p, __PIDTYPE_TGID);
1305 static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
1307 return perf_event_pid_type(event, p, PIDTYPE_PID);
1311 * If we inherit events we want to return the parent event id
1314 static u64 primary_event_id(struct perf_event *event)
1319 id = event->parent->id;
1325 * Get the perf_event_context for a task and lock it.
1327 * This has to cope with with the fact that until it is locked,
1328 * the context could get moved to another task.
1330 static struct perf_event_context *
1331 perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
1333 struct perf_event_context *ctx;
1337 * One of the few rules of preemptible RCU is that one cannot do
1338 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1339 * part of the read side critical section was irqs-enabled -- see
1340 * rcu_read_unlock_special().
1342 * Since ctx->lock nests under rq->lock we must ensure the entire read
1343 * side critical section has interrupts disabled.
1345 local_irq_save(*flags);
1347 ctx = rcu_dereference(task->perf_event_ctxp[ctxn]);
1350 * If this context is a clone of another, it might
1351 * get swapped for another underneath us by
1352 * perf_event_task_sched_out, though the
1353 * rcu_read_lock() protects us from any context
1354 * getting freed. Lock the context and check if it
1355 * got swapped before we could get the lock, and retry
1356 * if so. If we locked the right context, then it
1357 * can't get swapped on us any more.
1359 raw_spin_lock(&ctx->lock);
1360 if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) {
1361 raw_spin_unlock(&ctx->lock);
1363 local_irq_restore(*flags);
1367 if (ctx->task == TASK_TOMBSTONE ||
1368 !atomic_inc_not_zero(&ctx->refcount)) {
1369 raw_spin_unlock(&ctx->lock);
1372 WARN_ON_ONCE(ctx->task != task);
1377 local_irq_restore(*flags);
1382 * Get the context for a task and increment its pin_count so it
1383 * can't get swapped to another task. This also increments its
1384 * reference count so that the context can't get freed.
1386 static struct perf_event_context *
1387 perf_pin_task_context(struct task_struct *task, int ctxn)
1389 struct perf_event_context *ctx;
1390 unsigned long flags;
1392 ctx = perf_lock_task_context(task, ctxn, &flags);
1395 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1400 static void perf_unpin_context(struct perf_event_context *ctx)
1402 unsigned long flags;
1404 raw_spin_lock_irqsave(&ctx->lock, flags);
1406 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1410 * Update the record of the current time in a context.
1412 static void update_context_time(struct perf_event_context *ctx)
1414 u64 now = perf_clock();
1416 ctx->time += now - ctx->timestamp;
1417 ctx->timestamp = now;
1420 static u64 perf_event_time(struct perf_event *event)
1422 struct perf_event_context *ctx = event->ctx;
1424 if (is_cgroup_event(event))
1425 return perf_cgroup_event_time(event);
1427 return ctx ? ctx->time : 0;
1431 * Update the total_time_enabled and total_time_running fields for a event.
1433 static void update_event_times(struct perf_event *event)
1435 struct perf_event_context *ctx = event->ctx;
1438 lockdep_assert_held(&ctx->lock);
1440 if (event->state < PERF_EVENT_STATE_INACTIVE ||
1441 event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
1445 * in cgroup mode, time_enabled represents
1446 * the time the event was enabled AND active
1447 * tasks were in the monitored cgroup. This is
1448 * independent of the activity of the context as
1449 * there may be a mix of cgroup and non-cgroup events.
1451 * That is why we treat cgroup events differently
1454 if (is_cgroup_event(event))
1455 run_end = perf_cgroup_event_time(event);
1456 else if (ctx->is_active)
1457 run_end = ctx->time;
1459 run_end = event->tstamp_stopped;
1461 event->total_time_enabled = run_end - event->tstamp_enabled;
1463 if (event->state == PERF_EVENT_STATE_INACTIVE)
1464 run_end = event->tstamp_stopped;
1466 run_end = perf_event_time(event);
1468 event->total_time_running = run_end - event->tstamp_running;
1473 * Update total_time_enabled and total_time_running for all events in a group.
1475 static void update_group_times(struct perf_event *leader)
1477 struct perf_event *event;
1479 update_event_times(leader);
1480 list_for_each_entry(event, &leader->sibling_list, group_entry)
1481 update_event_times(event);
1484 static enum event_type_t get_event_type(struct perf_event *event)
1486 struct perf_event_context *ctx = event->ctx;
1487 enum event_type_t event_type;
1489 lockdep_assert_held(&ctx->lock);
1492 * It's 'group type', really, because if our group leader is
1493 * pinned, so are we.
1495 if (event->group_leader != event)
1496 event = event->group_leader;
1498 event_type = event->attr.pinned ? EVENT_PINNED : EVENT_FLEXIBLE;
1500 event_type |= EVENT_CPU;
1505 static struct list_head *
1506 ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
1508 if (event->attr.pinned)
1509 return &ctx->pinned_groups;
1511 return &ctx->flexible_groups;
1515 * Add a event from the lists for its context.
1516 * Must be called with ctx->mutex and ctx->lock held.
1519 list_add_event(struct perf_event *event, struct perf_event_context *ctx)
1521 lockdep_assert_held(&ctx->lock);
1523 WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
1524 event->attach_state |= PERF_ATTACH_CONTEXT;
1527 * If we're a stand alone event or group leader, we go to the context
1528 * list, group events are kept attached to the group so that
1529 * perf_group_detach can, at all times, locate all siblings.
1531 if (event->group_leader == event) {
1532 struct list_head *list;
1534 event->group_caps = event->event_caps;
1536 list = ctx_group_list(event, ctx);
1537 list_add_tail(&event->group_entry, list);
1540 list_update_cgroup_event(event, ctx, true);
1542 list_add_rcu(&event->event_entry, &ctx->event_list);
1544 if (event->attr.inherit_stat)
1551 * Initialize event state based on the perf_event_attr::disabled.
1553 static inline void perf_event__state_init(struct perf_event *event)
1555 event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF :
1556 PERF_EVENT_STATE_INACTIVE;
1559 static void __perf_event_read_size(struct perf_event *event, int nr_siblings)
1561 int entry = sizeof(u64); /* value */
1565 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
1566 size += sizeof(u64);
1568 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
1569 size += sizeof(u64);
1571 if (event->attr.read_format & PERF_FORMAT_ID)
1572 entry += sizeof(u64);
1574 if (event->attr.read_format & PERF_FORMAT_GROUP) {
1576 size += sizeof(u64);
1580 event->read_size = size;
1583 static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
1585 struct perf_sample_data *data;
1588 if (sample_type & PERF_SAMPLE_IP)
1589 size += sizeof(data->ip);
1591 if (sample_type & PERF_SAMPLE_ADDR)
1592 size += sizeof(data->addr);
1594 if (sample_type & PERF_SAMPLE_PERIOD)
1595 size += sizeof(data->period);
1597 if (sample_type & PERF_SAMPLE_WEIGHT)
1598 size += sizeof(data->weight);
1600 if (sample_type & PERF_SAMPLE_READ)
1601 size += event->read_size;
1603 if (sample_type & PERF_SAMPLE_DATA_SRC)
1604 size += sizeof(data->data_src.val);
1606 if (sample_type & PERF_SAMPLE_TRANSACTION)
1607 size += sizeof(data->txn);
1609 if (sample_type & PERF_SAMPLE_PHYS_ADDR)
1610 size += sizeof(data->phys_addr);
1612 event->header_size = size;
1616 * Called at perf_event creation and when events are attached/detached from a
1619 static void perf_event__header_size(struct perf_event *event)
1621 __perf_event_read_size(event,
1622 event->group_leader->nr_siblings);
1623 __perf_event_header_size(event, event->attr.sample_type);
1626 static void perf_event__id_header_size(struct perf_event *event)
1628 struct perf_sample_data *data;
1629 u64 sample_type = event->attr.sample_type;
1632 if (sample_type & PERF_SAMPLE_TID)
1633 size += sizeof(data->tid_entry);
1635 if (sample_type & PERF_SAMPLE_TIME)
1636 size += sizeof(data->time);
1638 if (sample_type & PERF_SAMPLE_IDENTIFIER)
1639 size += sizeof(data->id);
1641 if (sample_type & PERF_SAMPLE_ID)
1642 size += sizeof(data->id);
1644 if (sample_type & PERF_SAMPLE_STREAM_ID)
1645 size += sizeof(data->stream_id);
1647 if (sample_type & PERF_SAMPLE_CPU)
1648 size += sizeof(data->cpu_entry);
1650 event->id_header_size = size;
1653 static bool perf_event_validate_size(struct perf_event *event)
1656 * The values computed here will be over-written when we actually
1659 __perf_event_read_size(event, event->group_leader->nr_siblings + 1);
1660 __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ);
1661 perf_event__id_header_size(event);
1664 * Sum the lot; should not exceed the 64k limit we have on records.
1665 * Conservative limit to allow for callchains and other variable fields.
1667 if (event->read_size + event->header_size +
1668 event->id_header_size + sizeof(struct perf_event_header) >= 16*1024)
1674 static void perf_group_attach(struct perf_event *event)
1676 struct perf_event *group_leader = event->group_leader, *pos;
1678 lockdep_assert_held(&event->ctx->lock);
1681 * We can have double attach due to group movement in perf_event_open.
1683 if (event->attach_state & PERF_ATTACH_GROUP)
1686 event->attach_state |= PERF_ATTACH_GROUP;
1688 if (group_leader == event)
1691 WARN_ON_ONCE(group_leader->ctx != event->ctx);
1693 group_leader->group_caps &= event->event_caps;
1695 list_add_tail(&event->group_entry, &group_leader->sibling_list);
1696 group_leader->nr_siblings++;
1698 perf_event__header_size(group_leader);
1700 list_for_each_entry(pos, &group_leader->sibling_list, group_entry)
1701 perf_event__header_size(pos);
1705 * Remove a event from the lists for its context.
1706 * Must be called with ctx->mutex and ctx->lock held.
1709 list_del_event(struct perf_event *event, struct perf_event_context *ctx)
1711 WARN_ON_ONCE(event->ctx != ctx);
1712 lockdep_assert_held(&ctx->lock);
1715 * We can have double detach due to exit/hot-unplug + close.
1717 if (!(event->attach_state & PERF_ATTACH_CONTEXT))
1720 event->attach_state &= ~PERF_ATTACH_CONTEXT;
1722 list_update_cgroup_event(event, ctx, false);
1725 if (event->attr.inherit_stat)
1728 list_del_rcu(&event->event_entry);
1730 if (event->group_leader == event)
1731 list_del_init(&event->group_entry);
1733 update_group_times(event);
1736 * If event was in error state, then keep it
1737 * that way, otherwise bogus counts will be
1738 * returned on read(). The only way to get out
1739 * of error state is by explicit re-enabling
1742 if (event->state > PERF_EVENT_STATE_OFF)
1743 event->state = PERF_EVENT_STATE_OFF;
1748 static void perf_group_detach(struct perf_event *event)
1750 struct perf_event *sibling, *tmp;
1751 struct list_head *list = NULL;
1753 lockdep_assert_held(&event->ctx->lock);
1756 * We can have double detach due to exit/hot-unplug + close.
1758 if (!(event->attach_state & PERF_ATTACH_GROUP))
1761 event->attach_state &= ~PERF_ATTACH_GROUP;
1764 * If this is a sibling, remove it from its group.
1766 if (event->group_leader != event) {
1767 list_del_init(&event->group_entry);
1768 event->group_leader->nr_siblings--;
1772 if (!list_empty(&event->group_entry))
1773 list = &event->group_entry;
1776 * If this was a group event with sibling events then
1777 * upgrade the siblings to singleton events by adding them
1778 * to whatever list we are on.
1780 list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
1782 list_move_tail(&sibling->group_entry, list);
1783 sibling->group_leader = sibling;
1785 /* Inherit group flags from the previous leader */
1786 sibling->group_caps = event->group_caps;
1788 WARN_ON_ONCE(sibling->ctx != event->ctx);
1792 perf_event__header_size(event->group_leader);
1794 list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry)
1795 perf_event__header_size(tmp);
1798 static bool is_orphaned_event(struct perf_event *event)
1800 return event->state == PERF_EVENT_STATE_DEAD;
1803 static inline int __pmu_filter_match(struct perf_event *event)
1805 struct pmu *pmu = event->pmu;
1806 return pmu->filter_match ? pmu->filter_match(event) : 1;
1810 * Check whether we should attempt to schedule an event group based on
1811 * PMU-specific filtering. An event group can consist of HW and SW events,
1812 * potentially with a SW leader, so we must check all the filters, to
1813 * determine whether a group is schedulable:
1815 static inline int pmu_filter_match(struct perf_event *event)
1817 struct perf_event *child;
1819 if (!__pmu_filter_match(event))
1822 list_for_each_entry(child, &event->sibling_list, group_entry) {
1823 if (!__pmu_filter_match(child))
1831 event_filter_match(struct perf_event *event)
1833 return (event->cpu == -1 || event->cpu == smp_processor_id()) &&
1834 perf_cgroup_match(event) && pmu_filter_match(event);
1838 event_sched_out(struct perf_event *event,
1839 struct perf_cpu_context *cpuctx,
1840 struct perf_event_context *ctx)
1842 u64 tstamp = perf_event_time(event);
1845 WARN_ON_ONCE(event->ctx != ctx);
1846 lockdep_assert_held(&ctx->lock);
1849 * An event which could not be activated because of
1850 * filter mismatch still needs to have its timings
1851 * maintained, otherwise bogus information is return
1852 * via read() for time_enabled, time_running:
1854 if (event->state == PERF_EVENT_STATE_INACTIVE &&
1855 !event_filter_match(event)) {
1856 delta = tstamp - event->tstamp_stopped;
1857 event->tstamp_running += delta;
1858 event->tstamp_stopped = tstamp;
1861 if (event->state != PERF_EVENT_STATE_ACTIVE)
1864 perf_pmu_disable(event->pmu);
1866 event->tstamp_stopped = tstamp;
1867 event->pmu->del(event, 0);
1869 event->state = PERF_EVENT_STATE_INACTIVE;
1870 if (event->pending_disable) {
1871 event->pending_disable = 0;
1872 event->state = PERF_EVENT_STATE_OFF;
1875 if (!is_software_event(event))
1876 cpuctx->active_oncpu--;
1877 if (!--ctx->nr_active)
1878 perf_event_ctx_deactivate(ctx);
1879 if (event->attr.freq && event->attr.sample_freq)
1881 if (event->attr.exclusive || !cpuctx->active_oncpu)
1882 cpuctx->exclusive = 0;
1884 perf_pmu_enable(event->pmu);
1888 group_sched_out(struct perf_event *group_event,
1889 struct perf_cpu_context *cpuctx,
1890 struct perf_event_context *ctx)
1892 struct perf_event *event;
1893 int state = group_event->state;
1895 perf_pmu_disable(ctx->pmu);
1897 event_sched_out(group_event, cpuctx, ctx);
1900 * Schedule out siblings (if any):
1902 list_for_each_entry(event, &group_event->sibling_list, group_entry)
1903 event_sched_out(event, cpuctx, ctx);
1905 perf_pmu_enable(ctx->pmu);
1907 if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive)
1908 cpuctx->exclusive = 0;
1911 #define DETACH_GROUP 0x01UL
1914 * Cross CPU call to remove a performance event
1916 * We disable the event on the hardware level first. After that we
1917 * remove it from the context list.
1920 __perf_remove_from_context(struct perf_event *event,
1921 struct perf_cpu_context *cpuctx,
1922 struct perf_event_context *ctx,
1925 unsigned long flags = (unsigned long)info;
1927 event_sched_out(event, cpuctx, ctx);
1928 if (flags & DETACH_GROUP)
1929 perf_group_detach(event);
1930 list_del_event(event, ctx);
1932 if (!ctx->nr_events && ctx->is_active) {
1935 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
1936 cpuctx->task_ctx = NULL;
1942 * Remove the event from a task's (or a CPU's) list of events.
1944 * If event->ctx is a cloned context, callers must make sure that
1945 * every task struct that event->ctx->task could possibly point to
1946 * remains valid. This is OK when called from perf_release since
1947 * that only calls us on the top-level context, which can't be a clone.
1948 * When called from perf_event_exit_task, it's OK because the
1949 * context has been detached from its task.
1951 static void perf_remove_from_context(struct perf_event *event, unsigned long flags)
1953 struct perf_event_context *ctx = event->ctx;
1955 lockdep_assert_held(&ctx->mutex);
1957 event_function_call(event, __perf_remove_from_context, (void *)flags);
1960 * The above event_function_call() can NO-OP when it hits
1961 * TASK_TOMBSTONE. In that case we must already have been detached
1962 * from the context (by perf_event_exit_event()) but the grouping
1963 * might still be in-tact.
1965 WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
1966 if ((flags & DETACH_GROUP) &&
1967 (event->attach_state & PERF_ATTACH_GROUP)) {
1969 * Since in that case we cannot possibly be scheduled, simply
1972 raw_spin_lock_irq(&ctx->lock);
1973 perf_group_detach(event);
1974 raw_spin_unlock_irq(&ctx->lock);
1979 * Cross CPU call to disable a performance event
1981 static void __perf_event_disable(struct perf_event *event,
1982 struct perf_cpu_context *cpuctx,
1983 struct perf_event_context *ctx,
1986 if (event->state < PERF_EVENT_STATE_INACTIVE)
1989 update_context_time(ctx);
1990 update_cgrp_time_from_event(event);
1991 update_group_times(event);
1992 if (event == event->group_leader)
1993 group_sched_out(event, cpuctx, ctx);
1995 event_sched_out(event, cpuctx, ctx);
1996 event->state = PERF_EVENT_STATE_OFF;
2002 * If event->ctx is a cloned context, callers must make sure that
2003 * every task struct that event->ctx->task could possibly point to
2004 * remains valid. This condition is satisifed when called through
2005 * perf_event_for_each_child or perf_event_for_each because they
2006 * hold the top-level event's child_mutex, so any descendant that
2007 * goes to exit will block in perf_event_exit_event().
2009 * When called from perf_pending_event it's OK because event->ctx
2010 * is the current context on this CPU and preemption is disabled,
2011 * hence we can't get into perf_event_task_sched_out for this context.
2013 static void _perf_event_disable(struct perf_event *event)
2015 struct perf_event_context *ctx = event->ctx;
2017 raw_spin_lock_irq(&ctx->lock);
2018 if (event->state <= PERF_EVENT_STATE_OFF) {
2019 raw_spin_unlock_irq(&ctx->lock);
2022 raw_spin_unlock_irq(&ctx->lock);
2024 event_function_call(event, __perf_event_disable, NULL);
2027 void perf_event_disable_local(struct perf_event *event)
2029 event_function_local(event, __perf_event_disable, NULL);
2033 * Strictly speaking kernel users cannot create groups and therefore this
2034 * interface does not need the perf_event_ctx_lock() magic.
2036 void perf_event_disable(struct perf_event *event)
2038 struct perf_event_context *ctx;
2040 ctx = perf_event_ctx_lock(event);
2041 _perf_event_disable(event);
2042 perf_event_ctx_unlock(event, ctx);
2044 EXPORT_SYMBOL_GPL(perf_event_disable);
2046 void perf_event_disable_inatomic(struct perf_event *event)
2048 event->pending_disable = 1;
2049 irq_work_queue(&event->pending);
2052 static void perf_set_shadow_time(struct perf_event *event,
2053 struct perf_event_context *ctx,
2057 * use the correct time source for the time snapshot
2059 * We could get by without this by leveraging the
2060 * fact that to get to this function, the caller
2061 * has most likely already called update_context_time()
2062 * and update_cgrp_time_xx() and thus both timestamp
2063 * are identical (or very close). Given that tstamp is,
2064 * already adjusted for cgroup, we could say that:
2065 * tstamp - ctx->timestamp
2067 * tstamp - cgrp->timestamp.
2069 * Then, in perf_output_read(), the calculation would
2070 * work with no changes because:
2071 * - event is guaranteed scheduled in
2072 * - no scheduled out in between
2073 * - thus the timestamp would be the same
2075 * But this is a bit hairy.
2077 * So instead, we have an explicit cgroup call to remain
2078 * within the time time source all along. We believe it
2079 * is cleaner and simpler to understand.
2081 if (is_cgroup_event(event))
2082 perf_cgroup_set_shadow_time(event, tstamp);
2084 event->shadow_ctx_time = tstamp - ctx->timestamp;
2087 #define MAX_INTERRUPTS (~0ULL)
2089 static void perf_log_throttle(struct perf_event *event, int enable);
2090 static void perf_log_itrace_start(struct perf_event *event);
2093 event_sched_in(struct perf_event *event,
2094 struct perf_cpu_context *cpuctx,
2095 struct perf_event_context *ctx)
2097 u64 tstamp = perf_event_time(event);
2100 lockdep_assert_held(&ctx->lock);
2102 if (event->state <= PERF_EVENT_STATE_OFF)
2105 WRITE_ONCE(event->oncpu, smp_processor_id());
2107 * Order event::oncpu write to happen before the ACTIVE state
2111 WRITE_ONCE(event->state, PERF_EVENT_STATE_ACTIVE);
2114 * Unthrottle events, since we scheduled we might have missed several
2115 * ticks already, also for a heavily scheduling task there is little
2116 * guarantee it'll get a tick in a timely manner.
2118 if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
2119 perf_log_throttle(event, 1);
2120 event->hw.interrupts = 0;
2124 * The new state must be visible before we turn it on in the hardware:
2128 perf_pmu_disable(event->pmu);
2130 perf_set_shadow_time(event, ctx, tstamp);
2132 perf_log_itrace_start(event);
2134 if (event->pmu->add(event, PERF_EF_START)) {
2135 event->state = PERF_EVENT_STATE_INACTIVE;
2141 event->tstamp_running += tstamp - event->tstamp_stopped;
2143 if (!is_software_event(event))
2144 cpuctx->active_oncpu++;
2145 if (!ctx->nr_active++)
2146 perf_event_ctx_activate(ctx);
2147 if (event->attr.freq && event->attr.sample_freq)
2150 if (event->attr.exclusive)
2151 cpuctx->exclusive = 1;
2154 perf_pmu_enable(event->pmu);
2160 group_sched_in(struct perf_event *group_event,
2161 struct perf_cpu_context *cpuctx,
2162 struct perf_event_context *ctx)
2164 struct perf_event *event, *partial_group = NULL;
2165 struct pmu *pmu = ctx->pmu;
2166 u64 now = ctx->time;
2167 bool simulate = false;
2169 if (group_event->state == PERF_EVENT_STATE_OFF)
2172 pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
2174 if (event_sched_in(group_event, cpuctx, ctx)) {
2175 pmu->cancel_txn(pmu);
2176 perf_mux_hrtimer_restart(cpuctx);
2181 * Schedule in siblings as one group (if any):
2183 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
2184 if (event_sched_in(event, cpuctx, ctx)) {
2185 partial_group = event;
2190 if (!pmu->commit_txn(pmu))
2195 * Groups can be scheduled in as one unit only, so undo any
2196 * partial group before returning:
2197 * The events up to the failed event are scheduled out normally,
2198 * tstamp_stopped will be updated.
2200 * The failed events and the remaining siblings need to have
2201 * their timings updated as if they had gone thru event_sched_in()
2202 * and event_sched_out(). This is required to get consistent timings
2203 * across the group. This also takes care of the case where the group
2204 * could never be scheduled by ensuring tstamp_stopped is set to mark
2205 * the time the event was actually stopped, such that time delta
2206 * calculation in update_event_times() is correct.
2208 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
2209 if (event == partial_group)
2213 event->tstamp_running += now - event->tstamp_stopped;
2214 event->tstamp_stopped = now;
2216 event_sched_out(event, cpuctx, ctx);
2219 event_sched_out(group_event, cpuctx, ctx);
2221 pmu->cancel_txn(pmu);
2223 perf_mux_hrtimer_restart(cpuctx);
2229 * Work out whether we can put this event group on the CPU now.
2231 static int group_can_go_on(struct perf_event *event,
2232 struct perf_cpu_context *cpuctx,
2236 * Groups consisting entirely of software events can always go on.
2238 if (event->group_caps & PERF_EV_CAP_SOFTWARE)
2241 * If an exclusive group is already on, no other hardware
2244 if (cpuctx->exclusive)
2247 * If this group is exclusive and there are already
2248 * events on the CPU, it can't go on.
2250 if (event->attr.exclusive && cpuctx->active_oncpu)
2253 * Otherwise, try to add it if all previous groups were able
2260 * Complement to update_event_times(). This computes the tstamp_* values to
2261 * continue 'enabled' state from @now, and effectively discards the time
2262 * between the prior tstamp_stopped and now (as we were in the OFF state, or
2263 * just switched (context) time base).
2265 * This further assumes '@event->state == INACTIVE' (we just came from OFF) and
2266 * cannot have been scheduled in yet. And going into INACTIVE state means
2267 * '@event->tstamp_stopped = @now'.
2269 * Thus given the rules of update_event_times():
2271 * total_time_enabled = tstamp_stopped - tstamp_enabled
2272 * total_time_running = tstamp_stopped - tstamp_running
2274 * We can insert 'tstamp_stopped == now' and reverse them to compute new
2277 static void __perf_event_enable_time(struct perf_event *event, u64 now)
2279 WARN_ON_ONCE(event->state != PERF_EVENT_STATE_INACTIVE);
2281 event->tstamp_stopped = now;
2282 event->tstamp_enabled = now - event->total_time_enabled;
2283 event->tstamp_running = now - event->total_time_running;
2286 static void add_event_to_ctx(struct perf_event *event,
2287 struct perf_event_context *ctx)
2289 u64 tstamp = perf_event_time(event);
2291 list_add_event(event, ctx);
2292 perf_group_attach(event);
2294 * We can be called with event->state == STATE_OFF when we create with
2295 * .disabled = 1. In that case the IOC_ENABLE will call this function.
2297 if (event->state == PERF_EVENT_STATE_INACTIVE)
2298 __perf_event_enable_time(event, tstamp);
2301 static void ctx_sched_out(struct perf_event_context *ctx,
2302 struct perf_cpu_context *cpuctx,
2303 enum event_type_t event_type);
2305 ctx_sched_in(struct perf_event_context *ctx,
2306 struct perf_cpu_context *cpuctx,
2307 enum event_type_t event_type,
2308 struct task_struct *task);
2310 static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
2311 struct perf_event_context *ctx,
2312 enum event_type_t event_type)
2314 if (!cpuctx->task_ctx)
2317 if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
2320 ctx_sched_out(ctx, cpuctx, event_type);
2323 static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
2324 struct perf_event_context *ctx,
2325 struct task_struct *task)
2327 cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task);
2329 ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task);
2330 cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task);
2332 ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
2336 * We want to maintain the following priority of scheduling:
2337 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2338 * - task pinned (EVENT_PINNED)
2339 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2340 * - task flexible (EVENT_FLEXIBLE).
2342 * In order to avoid unscheduling and scheduling back in everything every
2343 * time an event is added, only do it for the groups of equal priority and
2346 * This can be called after a batch operation on task events, in which case
2347 * event_type is a bit mask of the types of events involved. For CPU events,
2348 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2350 static void ctx_resched(struct perf_cpu_context *cpuctx,
2351 struct perf_event_context *task_ctx,
2352 enum event_type_t event_type)
2354 enum event_type_t ctx_event_type;
2355 bool cpu_event = !!(event_type & EVENT_CPU);
2358 * If pinned groups are involved, flexible groups also need to be
2361 if (event_type & EVENT_PINNED)
2362 event_type |= EVENT_FLEXIBLE;
2364 ctx_event_type = event_type & EVENT_ALL;
2366 perf_pmu_disable(cpuctx->ctx.pmu);
2368 task_ctx_sched_out(cpuctx, task_ctx, event_type);
2371 * Decide which cpu ctx groups to schedule out based on the types
2372 * of events that caused rescheduling:
2373 * - EVENT_CPU: schedule out corresponding groups;
2374 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2375 * - otherwise, do nothing more.
2378 cpu_ctx_sched_out(cpuctx, ctx_event_type);
2379 else if (ctx_event_type & EVENT_PINNED)
2380 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
2382 perf_event_sched_in(cpuctx, task_ctx, current);
2383 perf_pmu_enable(cpuctx->ctx.pmu);
2387 * Cross CPU call to install and enable a performance event
2389 * Very similar to remote_function() + event_function() but cannot assume that
2390 * things like ctx->is_active and cpuctx->task_ctx are set.
2392 static int __perf_install_in_context(void *info)
2394 struct perf_event *event = info;
2395 struct perf_event_context *ctx = event->ctx;
2396 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
2397 struct perf_event_context *task_ctx = cpuctx->task_ctx;
2398 bool reprogram = true;
2401 raw_spin_lock(&cpuctx->ctx.lock);
2403 raw_spin_lock(&ctx->lock);
2406 reprogram = (ctx->task == current);
2409 * If the task is running, it must be running on this CPU,
2410 * otherwise we cannot reprogram things.
2412 * If its not running, we don't care, ctx->lock will
2413 * serialize against it becoming runnable.
2415 if (task_curr(ctx->task) && !reprogram) {
2420 WARN_ON_ONCE(reprogram && cpuctx->task_ctx && cpuctx->task_ctx != ctx);
2421 } else if (task_ctx) {
2422 raw_spin_lock(&task_ctx->lock);
2425 #ifdef CONFIG_CGROUP_PERF
2426 if (is_cgroup_event(event)) {
2428 * If the current cgroup doesn't match the event's
2429 * cgroup, we should not try to schedule it.
2431 struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx);
2432 reprogram = cgroup_is_descendant(cgrp->css.cgroup,
2433 event->cgrp->css.cgroup);
2438 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
2439 add_event_to_ctx(event, ctx);
2440 ctx_resched(cpuctx, task_ctx, get_event_type(event));
2442 add_event_to_ctx(event, ctx);
2446 perf_ctx_unlock(cpuctx, task_ctx);
2452 * Attach a performance event to a context.
2454 * Very similar to event_function_call, see comment there.
2457 perf_install_in_context(struct perf_event_context *ctx,
2458 struct perf_event *event,
2461 struct task_struct *task = READ_ONCE(ctx->task);
2463 lockdep_assert_held(&ctx->mutex);
2465 if (event->cpu != -1)
2469 * Ensures that if we can observe event->ctx, both the event and ctx
2470 * will be 'complete'. See perf_iterate_sb_cpu().
2472 smp_store_release(&event->ctx, ctx);
2475 cpu_function_call(cpu, __perf_install_in_context, event);
2480 * Should not happen, we validate the ctx is still alive before calling.
2482 if (WARN_ON_ONCE(task == TASK_TOMBSTONE))
2486 * Installing events is tricky because we cannot rely on ctx->is_active
2487 * to be set in case this is the nr_events 0 -> 1 transition.
2489 * Instead we use task_curr(), which tells us if the task is running.
2490 * However, since we use task_curr() outside of rq::lock, we can race
2491 * against the actual state. This means the result can be wrong.
2493 * If we get a false positive, we retry, this is harmless.
2495 * If we get a false negative, things are complicated. If we are after
2496 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2497 * value must be correct. If we're before, it doesn't matter since
2498 * perf_event_context_sched_in() will program the counter.
2500 * However, this hinges on the remote context switch having observed
2501 * our task->perf_event_ctxp[] store, such that it will in fact take
2502 * ctx::lock in perf_event_context_sched_in().
2504 * We do this by task_function_call(), if the IPI fails to hit the task
2505 * we know any future context switch of task must see the
2506 * perf_event_ctpx[] store.
2510 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2511 * task_cpu() load, such that if the IPI then does not find the task
2512 * running, a future context switch of that task must observe the
2517 if (!task_function_call(task, __perf_install_in_context, event))
2520 raw_spin_lock_irq(&ctx->lock);
2522 if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) {
2524 * Cannot happen because we already checked above (which also
2525 * cannot happen), and we hold ctx->mutex, which serializes us
2526 * against perf_event_exit_task_context().
2528 raw_spin_unlock_irq(&ctx->lock);
2532 * If the task is not running, ctx->lock will avoid it becoming so,
2533 * thus we can safely install the event.
2535 if (task_curr(task)) {
2536 raw_spin_unlock_irq(&ctx->lock);
2539 add_event_to_ctx(event, ctx);
2540 raw_spin_unlock_irq(&ctx->lock);
2544 * Put a event into inactive state and update time fields.
2545 * Enabling the leader of a group effectively enables all
2546 * the group members that aren't explicitly disabled, so we
2547 * have to update their ->tstamp_enabled also.
2548 * Note: this works for group members as well as group leaders
2549 * since the non-leader members' sibling_lists will be empty.
2551 static void __perf_event_mark_enabled(struct perf_event *event)
2553 struct perf_event *sub;
2554 u64 tstamp = perf_event_time(event);
2556 event->state = PERF_EVENT_STATE_INACTIVE;
2557 __perf_event_enable_time(event, tstamp);
2558 list_for_each_entry(sub, &event->sibling_list, group_entry) {
2559 /* XXX should not be > INACTIVE if event isn't */
2560 if (sub->state >= PERF_EVENT_STATE_INACTIVE)
2561 __perf_event_enable_time(sub, tstamp);
2566 * Cross CPU call to enable a performance event
2568 static void __perf_event_enable(struct perf_event *event,
2569 struct perf_cpu_context *cpuctx,
2570 struct perf_event_context *ctx,
2573 struct perf_event *leader = event->group_leader;
2574 struct perf_event_context *task_ctx;
2576 if (event->state >= PERF_EVENT_STATE_INACTIVE ||
2577 event->state <= PERF_EVENT_STATE_ERROR)
2581 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
2583 __perf_event_mark_enabled(event);
2585 if (!ctx->is_active)
2588 if (!event_filter_match(event)) {
2589 if (is_cgroup_event(event))
2590 perf_cgroup_defer_enabled(event);
2591 ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
2596 * If the event is in a group and isn't the group leader,
2597 * then don't put it on unless the group is on.
2599 if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) {
2600 ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
2604 task_ctx = cpuctx->task_ctx;
2606 WARN_ON_ONCE(task_ctx != ctx);
2608 ctx_resched(cpuctx, task_ctx, get_event_type(event));
2614 * If event->ctx is a cloned context, callers must make sure that
2615 * every task struct that event->ctx->task could possibly point to
2616 * remains valid. This condition is satisfied when called through
2617 * perf_event_for_each_child or perf_event_for_each as described
2618 * for perf_event_disable.
2620 static void _perf_event_enable(struct perf_event *event)
2622 struct perf_event_context *ctx = event->ctx;
2624 raw_spin_lock_irq(&ctx->lock);
2625 if (event->state >= PERF_EVENT_STATE_INACTIVE ||
2626 event->state < PERF_EVENT_STATE_ERROR) {
2627 raw_spin_unlock_irq(&ctx->lock);
2632 * If the event is in error state, clear that first.
2634 * That way, if we see the event in error state below, we know that it
2635 * has gone back into error state, as distinct from the task having
2636 * been scheduled away before the cross-call arrived.
2638 if (event->state == PERF_EVENT_STATE_ERROR)
2639 event->state = PERF_EVENT_STATE_OFF;
2640 raw_spin_unlock_irq(&ctx->lock);
2642 event_function_call(event, __perf_event_enable, NULL);
2646 * See perf_event_disable();
2648 void perf_event_enable(struct perf_event *event)
2650 struct perf_event_context *ctx;
2652 ctx = perf_event_ctx_lock(event);
2653 _perf_event_enable(event);
2654 perf_event_ctx_unlock(event, ctx);
2656 EXPORT_SYMBOL_GPL(perf_event_enable);
2658 struct stop_event_data {
2659 struct perf_event *event;
2660 unsigned int restart;
2663 static int __perf_event_stop(void *info)
2665 struct stop_event_data *sd = info;
2666 struct perf_event *event = sd->event;
2668 /* if it's already INACTIVE, do nothing */
2669 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
2672 /* matches smp_wmb() in event_sched_in() */
2676 * There is a window with interrupts enabled before we get here,
2677 * so we need to check again lest we try to stop another CPU's event.
2679 if (READ_ONCE(event->oncpu) != smp_processor_id())
2682 event->pmu->stop(event, PERF_EF_UPDATE);
2685 * May race with the actual stop (through perf_pmu_output_stop()),
2686 * but it is only used for events with AUX ring buffer, and such
2687 * events will refuse to restart because of rb::aux_mmap_count==0,
2688 * see comments in perf_aux_output_begin().
2690 * Since this is happening on a event-local CPU, no trace is lost
2694 event->pmu->start(event, 0);
2699 static int perf_event_stop(struct perf_event *event, int restart)
2701 struct stop_event_data sd = {
2708 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
2711 /* matches smp_wmb() in event_sched_in() */
2715 * We only want to restart ACTIVE events, so if the event goes
2716 * inactive here (event->oncpu==-1), there's nothing more to do;
2717 * fall through with ret==-ENXIO.
2719 ret = cpu_function_call(READ_ONCE(event->oncpu),
2720 __perf_event_stop, &sd);
2721 } while (ret == -EAGAIN);
2727 * In order to contain the amount of racy and tricky in the address filter
2728 * configuration management, it is a two part process:
2730 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2731 * we update the addresses of corresponding vmas in
2732 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2733 * (p2) when an event is scheduled in (pmu::add), it calls
2734 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2735 * if the generation has changed since the previous call.
2737 * If (p1) happens while the event is active, we restart it to force (p2).
2739 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2740 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2742 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2743 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2745 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2748 void perf_event_addr_filters_sync(struct perf_event *event)
2750 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
2752 if (!has_addr_filter(event))
2755 raw_spin_lock(&ifh->lock);
2756 if (event->addr_filters_gen != event->hw.addr_filters_gen) {
2757 event->pmu->addr_filters_sync(event);
2758 event->hw.addr_filters_gen = event->addr_filters_gen;
2760 raw_spin_unlock(&ifh->lock);
2762 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync);
2764 static int _perf_event_refresh(struct perf_event *event, int refresh)
2767 * not supported on inherited events
2769 if (event->attr.inherit || !is_sampling_event(event))
2772 atomic_add(refresh, &event->event_limit);
2773 _perf_event_enable(event);
2779 * See perf_event_disable()
2781 int perf_event_refresh(struct perf_event *event, int refresh)
2783 struct perf_event_context *ctx;
2786 ctx = perf_event_ctx_lock(event);
2787 ret = _perf_event_refresh(event, refresh);
2788 perf_event_ctx_unlock(event, ctx);
2792 EXPORT_SYMBOL_GPL(perf_event_refresh);
2794 static void ctx_sched_out(struct perf_event_context *ctx,
2795 struct perf_cpu_context *cpuctx,
2796 enum event_type_t event_type)
2798 int is_active = ctx->is_active;
2799 struct perf_event *event;
2801 lockdep_assert_held(&ctx->lock);
2803 if (likely(!ctx->nr_events)) {
2805 * See __perf_remove_from_context().
2807 WARN_ON_ONCE(ctx->is_active);
2809 WARN_ON_ONCE(cpuctx->task_ctx);
2813 ctx->is_active &= ~event_type;
2814 if (!(ctx->is_active & EVENT_ALL))
2818 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
2819 if (!ctx->is_active)
2820 cpuctx->task_ctx = NULL;
2824 * Always update time if it was set; not only when it changes.
2825 * Otherwise we can 'forget' to update time for any but the last
2826 * context we sched out. For example:
2828 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2829 * ctx_sched_out(.event_type = EVENT_PINNED)
2831 * would only update time for the pinned events.
2833 if (is_active & EVENT_TIME) {
2834 /* update (and stop) ctx time */
2835 update_context_time(ctx);
2836 update_cgrp_time_from_cpuctx(cpuctx);
2839 is_active ^= ctx->is_active; /* changed bits */
2841 if (!ctx->nr_active || !(is_active & EVENT_ALL))
2844 perf_pmu_disable(ctx->pmu);
2845 if (is_active & EVENT_PINNED) {
2846 list_for_each_entry(event, &ctx->pinned_groups, group_entry)
2847 group_sched_out(event, cpuctx, ctx);
2850 if (is_active & EVENT_FLEXIBLE) {
2851 list_for_each_entry(event, &ctx->flexible_groups, group_entry)
2852 group_sched_out(event, cpuctx, ctx);
2854 perf_pmu_enable(ctx->pmu);
2858 * Test whether two contexts are equivalent, i.e. whether they have both been
2859 * cloned from the same version of the same context.
2861 * Equivalence is measured using a generation number in the context that is
2862 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2863 * and list_del_event().
2865 static int context_equiv(struct perf_event_context *ctx1,
2866 struct perf_event_context *ctx2)
2868 lockdep_assert_held(&ctx1->lock);
2869 lockdep_assert_held(&ctx2->lock);
2871 /* Pinning disables the swap optimization */
2872 if (ctx1->pin_count || ctx2->pin_count)
2875 /* If ctx1 is the parent of ctx2 */
2876 if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen)
2879 /* If ctx2 is the parent of ctx1 */
2880 if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation)
2884 * If ctx1 and ctx2 have the same parent; we flatten the parent
2885 * hierarchy, see perf_event_init_context().
2887 if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx &&
2888 ctx1->parent_gen == ctx2->parent_gen)
2895 static void __perf_event_sync_stat(struct perf_event *event,
2896 struct perf_event *next_event)
2900 if (!event->attr.inherit_stat)
2904 * Update the event value, we cannot use perf_event_read()
2905 * because we're in the middle of a context switch and have IRQs
2906 * disabled, which upsets smp_call_function_single(), however
2907 * we know the event must be on the current CPU, therefore we
2908 * don't need to use it.
2910 switch (event->state) {
2911 case PERF_EVENT_STATE_ACTIVE:
2912 event->pmu->read(event);
2915 case PERF_EVENT_STATE_INACTIVE:
2916 update_event_times(event);
2924 * In order to keep per-task stats reliable we need to flip the event
2925 * values when we flip the contexts.
2927 value = local64_read(&next_event->count);
2928 value = local64_xchg(&event->count, value);
2929 local64_set(&next_event->count, value);
2931 swap(event->total_time_enabled, next_event->total_time_enabled);
2932 swap(event->total_time_running, next_event->total_time_running);
2935 * Since we swizzled the values, update the user visible data too.
2937 perf_event_update_userpage(event);
2938 perf_event_update_userpage(next_event);
2941 static void perf_event_sync_stat(struct perf_event_context *ctx,
2942 struct perf_event_context *next_ctx)
2944 struct perf_event *event, *next_event;
2949 update_context_time(ctx);
2951 event = list_first_entry(&ctx->event_list,
2952 struct perf_event, event_entry);
2954 next_event = list_first_entry(&next_ctx->event_list,
2955 struct perf_event, event_entry);
2957 while (&event->event_entry != &ctx->event_list &&
2958 &next_event->event_entry != &next_ctx->event_list) {
2960 __perf_event_sync_stat(event, next_event);
2962 event = list_next_entry(event, event_entry);
2963 next_event = list_next_entry(next_event, event_entry);
2967 static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
2968 struct task_struct *next)
2970 struct perf_event_context *ctx = task->perf_event_ctxp[ctxn];
2971 struct perf_event_context *next_ctx;
2972 struct perf_event_context *parent, *next_parent;
2973 struct perf_cpu_context *cpuctx;
2979 cpuctx = __get_cpu_context(ctx);
2980 if (!cpuctx->task_ctx)
2984 next_ctx = next->perf_event_ctxp[ctxn];
2988 parent = rcu_dereference(ctx->parent_ctx);
2989 next_parent = rcu_dereference(next_ctx->parent_ctx);
2991 /* If neither context have a parent context; they cannot be clones. */
2992 if (!parent && !next_parent)
2995 if (next_parent == ctx || next_ctx == parent || next_parent == parent) {
2997 * Looks like the two contexts are clones, so we might be
2998 * able to optimize the context switch. We lock both
2999 * contexts and check that they are clones under the
3000 * lock (including re-checking that neither has been
3001 * uncloned in the meantime). It doesn't matter which
3002 * order we take the locks because no other cpu could
3003 * be trying to lock both of these tasks.
3005 raw_spin_lock(&ctx->lock);
3006 raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
3007 if (context_equiv(ctx, next_ctx)) {
3008 WRITE_ONCE(ctx->task, next);
3009 WRITE_ONCE(next_ctx->task, task);
3011 swap(ctx->task_ctx_data, next_ctx->task_ctx_data);
3014 * RCU_INIT_POINTER here is safe because we've not
3015 * modified the ctx and the above modification of
3016 * ctx->task and ctx->task_ctx_data are immaterial
3017 * since those values are always verified under
3018 * ctx->lock which we're now holding.
3020 RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx);
3021 RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx);
3025 perf_event_sync_stat(ctx, next_ctx);
3027 raw_spin_unlock(&next_ctx->lock);
3028 raw_spin_unlock(&ctx->lock);
3034 raw_spin_lock(&ctx->lock);
3035 task_ctx_sched_out(cpuctx, ctx, EVENT_ALL);
3036 raw_spin_unlock(&ctx->lock);
3040 static DEFINE_PER_CPU(struct list_head, sched_cb_list);
3042 void perf_sched_cb_dec(struct pmu *pmu)
3044 struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
3046 this_cpu_dec(perf_sched_cb_usages);
3048 if (!--cpuctx->sched_cb_usage)
3049 list_del(&cpuctx->sched_cb_entry);
3053 void perf_sched_cb_inc(struct pmu *pmu)
3055 struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
3057 if (!cpuctx->sched_cb_usage++)
3058 list_add(&cpuctx->sched_cb_entry, this_cpu_ptr(&sched_cb_list));
3060 this_cpu_inc(perf_sched_cb_usages);
3064 * This function provides the context switch callback to the lower code
3065 * layer. It is invoked ONLY when the context switch callback is enabled.
3067 * This callback is relevant even to per-cpu events; for example multi event
3068 * PEBS requires this to provide PID/TID information. This requires we flush
3069 * all queued PEBS records before we context switch to a new task.
3071 static void perf_pmu_sched_task(struct task_struct *prev,
3072 struct task_struct *next,
3075 struct perf_cpu_context *cpuctx;
3081 list_for_each_entry(cpuctx, this_cpu_ptr(&sched_cb_list), sched_cb_entry) {
3082 pmu = cpuctx->ctx.pmu; /* software PMUs will not have sched_task */
3084 if (WARN_ON_ONCE(!pmu->sched_task))
3087 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
3088 perf_pmu_disable(pmu);
3090 pmu->sched_task(cpuctx->task_ctx, sched_in);
3092 perf_pmu_enable(pmu);
3093 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
3097 static void perf_event_switch(struct task_struct *task,
3098 struct task_struct *next_prev, bool sched_in);
3100 #define for_each_task_context_nr(ctxn) \
3101 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3104 * Called from scheduler to remove the events of the current task,
3105 * with interrupts disabled.
3107 * We stop each event and update the event value in event->count.
3109 * This does not protect us against NMI, but disable()
3110 * sets the disabled bit in the control field of event _before_
3111 * accessing the event control register. If a NMI hits, then it will
3112 * not restart the event.
3114 void __perf_event_task_sched_out(struct task_struct *task,
3115 struct task_struct *next)
3119 if (__this_cpu_read(perf_sched_cb_usages))
3120 perf_pmu_sched_task(task, next, false);
3122 if (atomic_read(&nr_switch_events))
3123 perf_event_switch(task, next, false);
3125 for_each_task_context_nr(ctxn)
3126 perf_event_context_sched_out(task, ctxn, next);
3129 * if cgroup events exist on this CPU, then we need
3130 * to check if we have to switch out PMU state.
3131 * cgroup event are system-wide mode only
3133 if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
3134 perf_cgroup_sched_out(task, next);
3138 * Called with IRQs disabled
3140 static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
3141 enum event_type_t event_type)
3143 ctx_sched_out(&cpuctx->ctx, cpuctx, event_type);
3147 ctx_pinned_sched_in(struct perf_event_context *ctx,
3148 struct perf_cpu_context *cpuctx)
3150 struct perf_event *event;
3152 list_for_each_entry(event, &ctx->pinned_groups, group_entry) {
3153 if (event->state <= PERF_EVENT_STATE_OFF)
3155 if (!event_filter_match(event))
3158 /* may need to reset tstamp_enabled */
3159 if (is_cgroup_event(event))
3160 perf_cgroup_mark_enabled(event, ctx);
3162 if (group_can_go_on(event, cpuctx, 1))
3163 group_sched_in(event, cpuctx, ctx);
3166 * If this pinned group hasn't been scheduled,
3167 * put it in error state.
3169 if (event->state == PERF_EVENT_STATE_INACTIVE) {
3170 update_group_times(event);
3171 event->state = PERF_EVENT_STATE_ERROR;
3177 ctx_flexible_sched_in(struct perf_event_context *ctx,
3178 struct perf_cpu_context *cpuctx)
3180 struct perf_event *event;
3183 list_for_each_entry(event, &ctx->flexible_groups, group_entry) {
3184 /* Ignore events in OFF or ERROR state */
3185 if (event->state <= PERF_EVENT_STATE_OFF)
3188 * Listen to the 'cpu' scheduling filter constraint
3191 if (!event_filter_match(event))
3194 /* may need to reset tstamp_enabled */
3195 if (is_cgroup_event(event))
3196 perf_cgroup_mark_enabled(event, ctx);
3198 if (group_can_go_on(event, cpuctx, can_add_hw)) {
3199 if (group_sched_in(event, cpuctx, ctx))
3206 ctx_sched_in(struct perf_event_context *ctx,
3207 struct perf_cpu_context *cpuctx,
3208 enum event_type_t event_type,
3209 struct task_struct *task)
3211 int is_active = ctx->is_active;
3214 lockdep_assert_held(&ctx->lock);
3216 if (likely(!ctx->nr_events))
3219 ctx->is_active |= (event_type | EVENT_TIME);
3222 cpuctx->task_ctx = ctx;
3224 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
3227 is_active ^= ctx->is_active; /* changed bits */
3229 if (is_active & EVENT_TIME) {
3230 /* start ctx time */
3232 ctx->timestamp = now;
3233 perf_cgroup_set_timestamp(task, ctx);
3237 * First go through the list and put on any pinned groups
3238 * in order to give them the best chance of going on.
3240 if (is_active & EVENT_PINNED)
3241 ctx_pinned_sched_in(ctx, cpuctx);
3243 /* Then walk through the lower prio flexible groups */
3244 if (is_active & EVENT_FLEXIBLE)
3245 ctx_flexible_sched_in(ctx, cpuctx);
3248 static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
3249 enum event_type_t event_type,
3250 struct task_struct *task)
3252 struct perf_event_context *ctx = &cpuctx->ctx;
3254 ctx_sched_in(ctx, cpuctx, event_type, task);
3257 static void perf_event_context_sched_in(struct perf_event_context *ctx,
3258 struct task_struct *task)
3260 struct perf_cpu_context *cpuctx;
3262 cpuctx = __get_cpu_context(ctx);
3263 if (cpuctx->task_ctx == ctx)
3266 perf_ctx_lock(cpuctx, ctx);
3268 * We must check ctx->nr_events while holding ctx->lock, such
3269 * that we serialize against perf_install_in_context().
3271 if (!ctx->nr_events)
3274 perf_pmu_disable(ctx->pmu);
3276 * We want to keep the following priority order:
3277 * cpu pinned (that don't need to move), task pinned,
3278 * cpu flexible, task flexible.
3280 * However, if task's ctx is not carrying any pinned
3281 * events, no need to flip the cpuctx's events around.
3283 if (!list_empty(&ctx->pinned_groups))
3284 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
3285 perf_event_sched_in(cpuctx, ctx, task);
3286 perf_pmu_enable(ctx->pmu);
3289 perf_ctx_unlock(cpuctx, ctx);
3293 * Called from scheduler to add the events of the current task
3294 * with interrupts disabled.
3296 * We restore the event value and then enable it.
3298 * This does not protect us against NMI, but enable()
3299 * sets the enabled bit in the control field of event _before_
3300 * accessing the event control register. If a NMI hits, then it will
3301 * keep the event running.
3303 void __perf_event_task_sched_in(struct task_struct *prev,
3304 struct task_struct *task)
3306 struct perf_event_context *ctx;
3310 * If cgroup events exist on this CPU, then we need to check if we have
3311 * to switch in PMU state; cgroup event are system-wide mode only.
3313 * Since cgroup events are CPU events, we must schedule these in before
3314 * we schedule in the task events.
3316 if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
3317 perf_cgroup_sched_in(prev, task);
3319 for_each_task_context_nr(ctxn) {
3320 ctx = task->perf_event_ctxp[ctxn];
3324 perf_event_context_sched_in(ctx, task);
3327 if (atomic_read(&nr_switch_events))
3328 perf_event_switch(task, prev, true);
3330 if (__this_cpu_read(perf_sched_cb_usages))
3331 perf_pmu_sched_task(prev, task, true);
3334 static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
3336 u64 frequency = event->attr.sample_freq;
3337 u64 sec = NSEC_PER_SEC;
3338 u64 divisor, dividend;
3340 int count_fls, nsec_fls, frequency_fls, sec_fls;
3342 count_fls = fls64(count);
3343 nsec_fls = fls64(nsec);
3344 frequency_fls = fls64(frequency);
3348 * We got @count in @nsec, with a target of sample_freq HZ
3349 * the target period becomes:
3352 * period = -------------------
3353 * @nsec * sample_freq
3358 * Reduce accuracy by one bit such that @a and @b converge
3359 * to a similar magnitude.
3361 #define REDUCE_FLS(a, b) \
3363 if (a##_fls > b##_fls) { \
3373 * Reduce accuracy until either term fits in a u64, then proceed with
3374 * the other, so that finally we can do a u64/u64 division.
3376 while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) {
3377 REDUCE_FLS(nsec, frequency);
3378 REDUCE_FLS(sec, count);
3381 if (count_fls + sec_fls > 64) {
3382 divisor = nsec * frequency;
3384 while (count_fls + sec_fls > 64) {
3385 REDUCE_FLS(count, sec);
3389 dividend = count * sec;
3391 dividend = count * sec;
3393 while (nsec_fls + frequency_fls > 64) {
3394 REDUCE_FLS(nsec, frequency);
3398 divisor = nsec * frequency;
3404 return div64_u64(dividend, divisor);
3407 static DEFINE_PER_CPU(int, perf_throttled_count);
3408 static DEFINE_PER_CPU(u64, perf_throttled_seq);
3410 static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable)
3412 struct hw_perf_event *hwc = &event->hw;
3413 s64 period, sample_period;
3416 period = perf_calculate_period(event, nsec, count);
3418 delta = (s64)(period - hwc->sample_period);
3419 delta = (delta + 7) / 8; /* low pass filter */
3421 sample_period = hwc->sample_period + delta;
3426 hwc->sample_period = sample_period;
3428 if (local64_read(&hwc->period_left) > 8*sample_period) {
3430 event->pmu->stop(event, PERF_EF_UPDATE);
3432 local64_set(&hwc->period_left, 0);
3435 event->pmu->start(event, PERF_EF_RELOAD);
3440 * combine freq adjustment with unthrottling to avoid two passes over the
3441 * events. At the same time, make sure, having freq events does not change
3442 * the rate of unthrottling as that would introduce bias.
3444 static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx,
3447 struct perf_event *event;
3448 struct hw_perf_event *hwc;
3449 u64 now, period = TICK_NSEC;
3453 * only need to iterate over all events iff:
3454 * - context have events in frequency mode (needs freq adjust)
3455 * - there are events to unthrottle on this cpu
3457 if (!(ctx->nr_freq || needs_unthr))
3460 raw_spin_lock(&ctx->lock);
3461 perf_pmu_disable(ctx->pmu);
3463 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
3464 if (event->state != PERF_EVENT_STATE_ACTIVE)
3467 if (!event_filter_match(event))
3470 perf_pmu_disable(event->pmu);
3474 if (hwc->interrupts == MAX_INTERRUPTS) {
3475 hwc->interrupts = 0;
3476 perf_log_throttle(event, 1);
3477 event->pmu->start(event, 0);
3480 if (!event->attr.freq || !event->attr.sample_freq)
3484 * stop the event and update event->count
3486 event->pmu->stop(event, PERF_EF_UPDATE);
3488 now = local64_read(&event->count);
3489 delta = now - hwc->freq_count_stamp;
3490 hwc->freq_count_stamp = now;
3494 * reload only if value has changed
3495 * we have stopped the event so tell that
3496 * to perf_adjust_period() to avoid stopping it
3500 perf_adjust_period(event, period, delta, false);
3502 event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
3504 perf_pmu_enable(event->pmu);
3507 perf_pmu_enable(ctx->pmu);
3508 raw_spin_unlock(&ctx->lock);
3512 * Round-robin a context's events:
3514 static void rotate_ctx(struct perf_event_context *ctx)
3517 * Rotate the first entry last of non-pinned groups. Rotation might be
3518 * disabled by the inheritance code.
3520 if (!ctx->rotate_disable)
3521 list_rotate_left(&ctx->flexible_groups);
3524 static int perf_rotate_context(struct perf_cpu_context *cpuctx)
3526 struct perf_event_context *ctx = NULL;
3529 if (cpuctx->ctx.nr_events) {
3530 if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
3534 ctx = cpuctx->task_ctx;
3535 if (ctx && ctx->nr_events) {
3536 if (ctx->nr_events != ctx->nr_active)
3543 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
3544 perf_pmu_disable(cpuctx->ctx.pmu);
3546 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
3548 ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE);
3550 rotate_ctx(&cpuctx->ctx);
3554 perf_event_sched_in(cpuctx, ctx, current);
3556 perf_pmu_enable(cpuctx->ctx.pmu);
3557 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
3563 void perf_event_task_tick(void)
3565 struct list_head *head = this_cpu_ptr(&active_ctx_list);
3566 struct perf_event_context *ctx, *tmp;
3569 WARN_ON(!irqs_disabled());
3571 __this_cpu_inc(perf_throttled_seq);
3572 throttled = __this_cpu_xchg(perf_throttled_count, 0);
3573 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
3575 list_for_each_entry_safe(ctx, tmp, head, active_ctx_list)
3576 perf_adjust_freq_unthr_context(ctx, throttled);
3579 static int event_enable_on_exec(struct perf_event *event,
3580 struct perf_event_context *ctx)
3582 if (!event->attr.enable_on_exec)
3585 event->attr.enable_on_exec = 0;
3586 if (event->state >= PERF_EVENT_STATE_INACTIVE)
3589 __perf_event_mark_enabled(event);
3595 * Enable all of a task's events that have been marked enable-on-exec.
3596 * This expects task == current.
3598 static void perf_event_enable_on_exec(int ctxn)
3600 struct perf_event_context *ctx, *clone_ctx = NULL;
3601 enum event_type_t event_type = 0;
3602 struct perf_cpu_context *cpuctx;
3603 struct perf_event *event;
3604 unsigned long flags;
3607 local_irq_save(flags);
3608 ctx = current->perf_event_ctxp[ctxn];
3609 if (!ctx || !ctx->nr_events)
3612 cpuctx = __get_cpu_context(ctx);
3613 perf_ctx_lock(cpuctx, ctx);
3614 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
3615 list_for_each_entry(event, &ctx->event_list, event_entry) {
3616 enabled |= event_enable_on_exec(event, ctx);
3617 event_type |= get_event_type(event);
3621 * Unclone and reschedule this context if we enabled any event.
3624 clone_ctx = unclone_ctx(ctx);
3625 ctx_resched(cpuctx, ctx, event_type);
3627 ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
3629 perf_ctx_unlock(cpuctx, ctx);
3632 local_irq_restore(flags);
3638 struct perf_read_data {
3639 struct perf_event *event;
3644 static int __perf_event_read_cpu(struct perf_event *event, int event_cpu)
3646 u16 local_pkg, event_pkg;
3648 if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) {
3649 int local_cpu = smp_processor_id();
3651 event_pkg = topology_physical_package_id(event_cpu);
3652 local_pkg = topology_physical_package_id(local_cpu);
3654 if (event_pkg == local_pkg)
3662 * Cross CPU call to read the hardware event
3664 static void __perf_event_read(void *info)
3666 struct perf_read_data *data = info;
3667 struct perf_event *sub, *event = data->event;
3668 struct perf_event_context *ctx = event->ctx;
3669 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
3670 struct pmu *pmu = event->pmu;
3673 * If this is a task context, we need to check whether it is
3674 * the current task context of this cpu. If not it has been
3675 * scheduled out before the smp call arrived. In that case
3676 * event->count would have been updated to a recent sample
3677 * when the event was scheduled out.
3679 if (ctx->task && cpuctx->task_ctx != ctx)
3682 raw_spin_lock(&ctx->lock);
3683 if (ctx->is_active) {
3684 update_context_time(ctx);
3685 update_cgrp_time_from_event(event);
3688 update_event_times(event);
3689 if (event->state != PERF_EVENT_STATE_ACTIVE)
3698 pmu->start_txn(pmu, PERF_PMU_TXN_READ);
3702 list_for_each_entry(sub, &event->sibling_list, group_entry) {
3703 update_event_times(sub);
3704 if (sub->state == PERF_EVENT_STATE_ACTIVE) {
3706 * Use sibling's PMU rather than @event's since
3707 * sibling could be on different (eg: software) PMU.
3709 sub->pmu->read(sub);
3713 data->ret = pmu->commit_txn(pmu);
3716 raw_spin_unlock(&ctx->lock);
3719 static inline u64 perf_event_count(struct perf_event *event)
3721 return local64_read(&event->count) + atomic64_read(&event->child_count);
3725 * NMI-safe method to read a local event, that is an event that
3727 * - either for the current task, or for this CPU
3728 * - does not have inherit set, for inherited task events
3729 * will not be local and we cannot read them atomically
3730 * - must not have a pmu::count method
3732 int perf_event_read_local(struct perf_event *event, u64 *value)
3734 unsigned long flags;
3738 * Disabling interrupts avoids all counter scheduling (context
3739 * switches, timer based rotation and IPIs).
3741 local_irq_save(flags);
3744 * It must not be an event with inherit set, we cannot read
3745 * all child counters from atomic context.
3747 if (event->attr.inherit) {
3752 /* If this is a per-task event, it must be for current */
3753 if ((event->attach_state & PERF_ATTACH_TASK) &&
3754 event->hw.target != current) {
3759 /* If this is a per-CPU event, it must be for this CPU */
3760 if (!(event->attach_state & PERF_ATTACH_TASK) &&
3761 event->cpu != smp_processor_id()) {
3766 /* If this is a pinned event it must be running on this CPU */
3767 if (event->attr.pinned && event->oncpu != smp_processor_id()) {
3773 * If the event is currently on this CPU, its either a per-task event,
3774 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3777 if (event->oncpu == smp_processor_id())
3778 event->pmu->read(event);
3780 *value = local64_read(&event->count);
3782 local_irq_restore(flags);
3787 static int perf_event_read(struct perf_event *event, bool group)
3789 int event_cpu, ret = 0;
3792 * If event is enabled and currently active on a CPU, update the
3793 * value in the event structure:
3795 if (event->state == PERF_EVENT_STATE_ACTIVE) {
3796 struct perf_read_data data = {
3802 event_cpu = READ_ONCE(event->oncpu);
3803 if ((unsigned)event_cpu >= nr_cpu_ids)
3807 event_cpu = __perf_event_read_cpu(event, event_cpu);
3810 * Purposely ignore the smp_call_function_single() return
3813 * If event_cpu isn't a valid CPU it means the event got
3814 * scheduled out and that will have updated the event count.
3816 * Therefore, either way, we'll have an up-to-date event count
3819 (void)smp_call_function_single(event_cpu, __perf_event_read, &data, 1);
3822 } else if (event->state == PERF_EVENT_STATE_INACTIVE) {
3823 struct perf_event_context *ctx = event->ctx;
3824 unsigned long flags;
3826 raw_spin_lock_irqsave(&ctx->lock, flags);
3828 * may read while context is not active
3829 * (e.g., thread is blocked), in that case
3830 * we cannot update context time
3832 if (ctx->is_active) {
3833 update_context_time(ctx);
3834 update_cgrp_time_from_event(event);
3837 update_group_times(event);
3839 update_event_times(event);
3840 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3847 * Initialize the perf_event context in a task_struct:
3849 static void __perf_event_init_context(struct perf_event_context *ctx)
3851 raw_spin_lock_init(&ctx->lock);
3852 mutex_init(&ctx->mutex);
3853 INIT_LIST_HEAD(&ctx->active_ctx_list);
3854 INIT_LIST_HEAD(&ctx->pinned_groups);
3855 INIT_LIST_HEAD(&ctx->flexible_groups);
3856 INIT_LIST_HEAD(&ctx->event_list);
3857 atomic_set(&ctx->refcount, 1);
3860 static struct perf_event_context *
3861 alloc_perf_context(struct pmu *pmu, struct task_struct *task)
3863 struct perf_event_context *ctx;
3865 ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
3869 __perf_event_init_context(ctx);
3872 get_task_struct(task);
3879 static struct task_struct *
3880 find_lively_task_by_vpid(pid_t vpid)
3882 struct task_struct *task;
3888 task = find_task_by_vpid(vpid);
3890 get_task_struct(task);
3894 return ERR_PTR(-ESRCH);
3900 * Returns a matching context with refcount and pincount.
3902 static struct perf_event_context *
3903 find_get_context(struct pmu *pmu, struct task_struct *task,
3904 struct perf_event *event)
3906 struct perf_event_context *ctx, *clone_ctx = NULL;
3907 struct perf_cpu_context *cpuctx;
3908 void *task_ctx_data = NULL;
3909 unsigned long flags;
3911 int cpu = event->cpu;
3914 /* Must be root to operate on a CPU event: */
3915 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
3916 return ERR_PTR(-EACCES);
3918 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
3921 raw_spin_lock_irqsave(&ctx->lock, flags);
3923 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3929 ctxn = pmu->task_ctx_nr;
3933 if (event->attach_state & PERF_ATTACH_TASK_DATA) {
3934 task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL);
3935 if (!task_ctx_data) {
3942 ctx = perf_lock_task_context(task, ctxn, &flags);
3944 clone_ctx = unclone_ctx(ctx);
3947 if (task_ctx_data && !ctx->task_ctx_data) {
3948 ctx->task_ctx_data = task_ctx_data;
3949 task_ctx_data = NULL;
3951 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3956 ctx = alloc_perf_context(pmu, task);
3961 if (task_ctx_data) {
3962 ctx->task_ctx_data = task_ctx_data;
3963 task_ctx_data = NULL;
3967 mutex_lock(&task->perf_event_mutex);
3969 * If it has already passed perf_event_exit_task().
3970 * we must see PF_EXITING, it takes this mutex too.
3972 if (task->flags & PF_EXITING)
3974 else if (task->perf_event_ctxp[ctxn])
3979 rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
3981 mutex_unlock(&task->perf_event_mutex);
3983 if (unlikely(err)) {
3992 kfree(task_ctx_data);
3996 kfree(task_ctx_data);
3997 return ERR_PTR(err);
4000 static void perf_event_free_filter(struct perf_event *event);
4001 static void perf_event_free_bpf_prog(struct perf_event *event);
4003 static void free_event_rcu(struct rcu_head *head)
4005 struct perf_event *event;
4007 event = container_of(head, struct perf_event, rcu_head);
4009 put_pid_ns(event->ns);
4010 perf_event_free_filter(event);
4014 static void ring_buffer_attach(struct perf_event *event,
4015 struct ring_buffer *rb);
4017 static void detach_sb_event(struct perf_event *event)
4019 struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
4021 raw_spin_lock(&pel->lock);
4022 list_del_rcu(&event->sb_list);
4023 raw_spin_unlock(&pel->lock);
4026 static bool is_sb_event(struct perf_event *event)
4028 struct perf_event_attr *attr = &event->attr;
4033 if (event->attach_state & PERF_ATTACH_TASK)
4036 if (attr->mmap || attr->mmap_data || attr->mmap2 ||
4037 attr->comm || attr->comm_exec ||
4039 attr->context_switch)
4044 static void unaccount_pmu_sb_event(struct perf_event *event)
4046 if (is_sb_event(event))
4047 detach_sb_event(event);
4050 static void unaccount_event_cpu(struct perf_event *event, int cpu)
4055 if (is_cgroup_event(event))
4056 atomic_dec(&per_cpu(perf_cgroup_events, cpu));
4059 #ifdef CONFIG_NO_HZ_FULL
4060 static DEFINE_SPINLOCK(nr_freq_lock);
4063 static void unaccount_freq_event_nohz(void)
4065 #ifdef CONFIG_NO_HZ_FULL
4066 spin_lock(&nr_freq_lock);
4067 if (atomic_dec_and_test(&nr_freq_events))
4068 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS);
4069 spin_unlock(&nr_freq_lock);
4073 static void unaccount_freq_event(void)
4075 if (tick_nohz_full_enabled())
4076 unaccount_freq_event_nohz();
4078 atomic_dec(&nr_freq_events);
4081 static void unaccount_event(struct perf_event *event)
4088 if (event->attach_state & PERF_ATTACH_TASK)
4090 if (event->attr.mmap || event->attr.mmap_data)
4091 atomic_dec(&nr_mmap_events);
4092 if (event->attr.comm)
4093 atomic_dec(&nr_comm_events);
4094 if (event->attr.namespaces)
4095 atomic_dec(&nr_namespaces_events);
4096 if (event->attr.task)
4097 atomic_dec(&nr_task_events);
4098 if (event->attr.freq)
4099 unaccount_freq_event();
4100 if (event->attr.context_switch) {
4102 atomic_dec(&nr_switch_events);
4104 if (is_cgroup_event(event))
4106 if (has_branch_stack(event))
4110 if (!atomic_add_unless(&perf_sched_count, -1, 1))
4111 schedule_delayed_work(&perf_sched_work, HZ);
4114 unaccount_event_cpu(event, event->cpu);
4116 unaccount_pmu_sb_event(event);
4119 static void perf_sched_delayed(struct work_struct *work)
4121 mutex_lock(&perf_sched_mutex);
4122 if (atomic_dec_and_test(&perf_sched_count))
4123 static_branch_disable(&perf_sched_events);
4124 mutex_unlock(&perf_sched_mutex);
4128 * The following implement mutual exclusion of events on "exclusive" pmus
4129 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4130 * at a time, so we disallow creating events that might conflict, namely:
4132 * 1) cpu-wide events in the presence of per-task events,
4133 * 2) per-task events in the presence of cpu-wide events,
4134 * 3) two matching events on the same context.
4136 * The former two cases are handled in the allocation path (perf_event_alloc(),
4137 * _free_event()), the latter -- before the first perf_install_in_context().
4139 static int exclusive_event_init(struct perf_event *event)
4141 struct pmu *pmu = event->pmu;
4143 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
4147 * Prevent co-existence of per-task and cpu-wide events on the
4148 * same exclusive pmu.
4150 * Negative pmu::exclusive_cnt means there are cpu-wide
4151 * events on this "exclusive" pmu, positive means there are
4154 * Since this is called in perf_event_alloc() path, event::ctx
4155 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4156 * to mean "per-task event", because unlike other attach states it
4157 * never gets cleared.
4159 if (event->attach_state & PERF_ATTACH_TASK) {
4160 if (!atomic_inc_unless_negative(&pmu->exclusive_cnt))
4163 if (!atomic_dec_unless_positive(&pmu->exclusive_cnt))
4170 static void exclusive_event_destroy(struct perf_event *event)
4172 struct pmu *pmu = event->pmu;
4174 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
4177 /* see comment in exclusive_event_init() */
4178 if (event->attach_state & PERF_ATTACH_TASK)
4179 atomic_dec(&pmu->exclusive_cnt);
4181 atomic_inc(&pmu->exclusive_cnt);
4184 static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2)
4186 if ((e1->pmu == e2->pmu) &&
4187 (e1->cpu == e2->cpu ||
4194 /* Called under the same ctx::mutex as perf_install_in_context() */
4195 static bool exclusive_event_installable(struct perf_event *event,
4196 struct perf_event_context *ctx)
4198 struct perf_event *iter_event;
4199 struct pmu *pmu = event->pmu;
4201 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
4204 list_for_each_entry(iter_event, &ctx->event_list, event_entry) {
4205 if (exclusive_event_match(iter_event, event))
4212 static void perf_addr_filters_splice(struct perf_event *event,
4213 struct list_head *head);
4215 static void _free_event(struct perf_event *event)
4217 irq_work_sync(&event->pending);
4219 unaccount_event(event);
4223 * Can happen when we close an event with re-directed output.
4225 * Since we have a 0 refcount, perf_mmap_close() will skip
4226 * over us; possibly making our ring_buffer_put() the last.
4228 mutex_lock(&event->mmap_mutex);
4229 ring_buffer_attach(event, NULL);
4230 mutex_unlock(&event->mmap_mutex);
4233 if (is_cgroup_event(event))
4234 perf_detach_cgroup(event);
4236 if (!event->parent) {
4237 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
4238 put_callchain_buffers();
4241 perf_event_free_bpf_prog(event);
4242 perf_addr_filters_splice(event, NULL);
4243 kfree(event->addr_filters_offs);
4246 event->destroy(event);
4249 put_ctx(event->ctx);
4251 if (event->hw.target)
4252 put_task_struct(event->hw.target);
4254 exclusive_event_destroy(event);
4255 module_put(event->pmu->module);
4257 call_rcu(&event->rcu_head, free_event_rcu);
4261 * Used to free events which have a known refcount of 1, such as in error paths
4262 * where the event isn't exposed yet and inherited events.
4264 static void free_event(struct perf_event *event)
4266 if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1,
4267 "unexpected event refcount: %ld; ptr=%p\n",
4268 atomic_long_read(&event->refcount), event)) {
4269 /* leak to avoid use-after-free */
4277 * Remove user event from the owner task.
4279 static void perf_remove_from_owner(struct perf_event *event)
4281 struct task_struct *owner;
4285 * Matches the smp_store_release() in perf_event_exit_task(). If we
4286 * observe !owner it means the list deletion is complete and we can
4287 * indeed free this event, otherwise we need to serialize on
4288 * owner->perf_event_mutex.
4290 owner = READ_ONCE(event->owner);
4293 * Since delayed_put_task_struct() also drops the last
4294 * task reference we can safely take a new reference
4295 * while holding the rcu_read_lock().
4297 get_task_struct(owner);
4303 * If we're here through perf_event_exit_task() we're already
4304 * holding ctx->mutex which would be an inversion wrt. the
4305 * normal lock order.
4307 * However we can safely take this lock because its the child
4310 mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING);
4313 * We have to re-check the event->owner field, if it is cleared
4314 * we raced with perf_event_exit_task(), acquiring the mutex
4315 * ensured they're done, and we can proceed with freeing the
4319 list_del_init(&event->owner_entry);
4320 smp_store_release(&event->owner, NULL);
4322 mutex_unlock(&owner->perf_event_mutex);
4323 put_task_struct(owner);
4327 static void put_event(struct perf_event *event)
4329 if (!atomic_long_dec_and_test(&event->refcount))
4336 * Kill an event dead; while event:refcount will preserve the event
4337 * object, it will not preserve its functionality. Once the last 'user'
4338 * gives up the object, we'll destroy the thing.
4340 int perf_event_release_kernel(struct perf_event *event)
4342 struct perf_event_context *ctx = event->ctx;
4343 struct perf_event *child, *tmp;
4346 * If we got here through err_file: fput(event_file); we will not have
4347 * attached to a context yet.
4350 WARN_ON_ONCE(event->attach_state &
4351 (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP));
4355 if (!is_kernel_event(event))
4356 perf_remove_from_owner(event);
4358 ctx = perf_event_ctx_lock(event);
4359 WARN_ON_ONCE(ctx->parent_ctx);
4360 perf_remove_from_context(event, DETACH_GROUP);
4362 raw_spin_lock_irq(&ctx->lock);
4364 * Mark this event as STATE_DEAD, there is no external reference to it
4367 * Anybody acquiring event->child_mutex after the below loop _must_
4368 * also see this, most importantly inherit_event() which will avoid
4369 * placing more children on the list.
4371 * Thus this guarantees that we will in fact observe and kill _ALL_
4374 event->state = PERF_EVENT_STATE_DEAD;
4375 raw_spin_unlock_irq(&ctx->lock);
4377 perf_event_ctx_unlock(event, ctx);
4380 mutex_lock(&event->child_mutex);
4381 list_for_each_entry(child, &event->child_list, child_list) {
4384 * Cannot change, child events are not migrated, see the
4385 * comment with perf_event_ctx_lock_nested().
4387 ctx = READ_ONCE(child->ctx);
4389 * Since child_mutex nests inside ctx::mutex, we must jump
4390 * through hoops. We start by grabbing a reference on the ctx.
4392 * Since the event cannot get freed while we hold the
4393 * child_mutex, the context must also exist and have a !0
4399 * Now that we have a ctx ref, we can drop child_mutex, and
4400 * acquire ctx::mutex without fear of it going away. Then we
4401 * can re-acquire child_mutex.
4403 mutex_unlock(&event->child_mutex);
4404 mutex_lock(&ctx->mutex);
4405 mutex_lock(&event->child_mutex);
4408 * Now that we hold ctx::mutex and child_mutex, revalidate our
4409 * state, if child is still the first entry, it didn't get freed
4410 * and we can continue doing so.
4412 tmp = list_first_entry_or_null(&event->child_list,
4413 struct perf_event, child_list);
4415 perf_remove_from_context(child, DETACH_GROUP);
4416 list_del(&child->child_list);
4419 * This matches the refcount bump in inherit_event();
4420 * this can't be the last reference.
4425 mutex_unlock(&event->child_mutex);
4426 mutex_unlock(&ctx->mutex);
4430 mutex_unlock(&event->child_mutex);
4433 put_event(event); /* Must be the 'last' reference */
4436 EXPORT_SYMBOL_GPL(perf_event_release_kernel);
4439 * Called when the last reference to the file is gone.
4441 static int perf_release(struct inode *inode, struct file *file)
4443 perf_event_release_kernel(file->private_data);
4447 u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
4449 struct perf_event *child;
4455 mutex_lock(&event->child_mutex);
4457 (void)perf_event_read(event, false);
4458 total += perf_event_count(event);
4460 *enabled += event->total_time_enabled +
4461 atomic64_read(&event->child_total_time_enabled);
4462 *running += event->total_time_running +
4463 atomic64_read(&event->child_total_time_running);
4465 list_for_each_entry(child, &event->child_list, child_list) {
4466 (void)perf_event_read(child, false);
4467 total += perf_event_count(child);
4468 *enabled += child->total_time_enabled;
4469 *running += child->total_time_running;
4471 mutex_unlock(&event->child_mutex);
4475 EXPORT_SYMBOL_GPL(perf_event_read_value);
4477 static int __perf_read_group_add(struct perf_event *leader,
4478 u64 read_format, u64 *values)
4480 struct perf_event_context *ctx = leader->ctx;
4481 struct perf_event *sub;
4482 unsigned long flags;
4483 int n = 1; /* skip @nr */
4486 ret = perf_event_read(leader, true);
4490 raw_spin_lock_irqsave(&ctx->lock, flags);
4493 * Since we co-schedule groups, {enabled,running} times of siblings
4494 * will be identical to those of the leader, so we only publish one
4497 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
4498 values[n++] += leader->total_time_enabled +
4499 atomic64_read(&leader->child_total_time_enabled);
4502 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
4503 values[n++] += leader->total_time_running +
4504 atomic64_read(&leader->child_total_time_running);
4508 * Write {count,id} tuples for every sibling.
4510 values[n++] += perf_event_count(leader);
4511 if (read_format & PERF_FORMAT_ID)
4512 values[n++] = primary_event_id(leader);
4514 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
4515 values[n++] += perf_event_count(sub);
4516 if (read_format & PERF_FORMAT_ID)
4517 values[n++] = primary_event_id(sub);
4520 raw_spin_unlock_irqrestore(&ctx->lock, flags);
4524 static int perf_read_group(struct perf_event *event,
4525 u64 read_format, char __user *buf)
4527 struct perf_event *leader = event->group_leader, *child;
4528 struct perf_event_context *ctx = leader->ctx;
4532 lockdep_assert_held(&ctx->mutex);
4534 values = kzalloc(event->read_size, GFP_KERNEL);
4538 values[0] = 1 + leader->nr_siblings;
4541 * By locking the child_mutex of the leader we effectively
4542 * lock the child list of all siblings.. XXX explain how.
4544 mutex_lock(&leader->child_mutex);
4546 ret = __perf_read_group_add(leader, read_format, values);
4550 list_for_each_entry(child, &leader->child_list, child_list) {
4551 ret = __perf_read_group_add(child, read_format, values);
4556 mutex_unlock(&leader->child_mutex);
4558 ret = event->read_size;
4559 if (copy_to_user(buf, values, event->read_size))
4564 mutex_unlock(&leader->child_mutex);
4570 static int perf_read_one(struct perf_event *event,
4571 u64 read_format, char __user *buf)
4573 u64 enabled, running;
4577 values[n++] = perf_event_read_value(event, &enabled, &running);
4578 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
4579 values[n++] = enabled;
4580 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
4581 values[n++] = running;
4582 if (read_format & PERF_FORMAT_ID)
4583 values[n++] = primary_event_id(event);
4585 if (copy_to_user(buf, values, n * sizeof(u64)))
4588 return n * sizeof(u64);
4591 static bool is_event_hup(struct perf_event *event)
4595 if (event->state > PERF_EVENT_STATE_EXIT)
4598 mutex_lock(&event->child_mutex);
4599 no_children = list_empty(&event->child_list);
4600 mutex_unlock(&event->child_mutex);
4605 * Read the performance event - simple non blocking version for now
4608 __perf_read(struct perf_event *event, char __user *buf, size_t count)
4610 u64 read_format = event->attr.read_format;
4614 * Return end-of-file for a read on a event that is in
4615 * error state (i.e. because it was pinned but it couldn't be
4616 * scheduled on to the CPU at some point).
4618 if (event->state == PERF_EVENT_STATE_ERROR)
4621 if (count < event->read_size)
4624 WARN_ON_ONCE(event->ctx->parent_ctx);
4625 if (read_format & PERF_FORMAT_GROUP)
4626 ret = perf_read_group(event, read_format, buf);
4628 ret = perf_read_one(event, read_format, buf);
4634 perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
4636 struct perf_event *event = file->private_data;
4637 struct perf_event_context *ctx;
4640 ctx = perf_event_ctx_lock(event);
4641 ret = __perf_read(event, buf, count);
4642 perf_event_ctx_unlock(event, ctx);
4647 static unsigned int perf_poll(struct file *file, poll_table *wait)
4649 struct perf_event *event = file->private_data;
4650 struct ring_buffer *rb;
4651 unsigned int events = POLLHUP;
4653 poll_wait(file, &event->waitq, wait);
4655 if (is_event_hup(event))
4659 * Pin the event->rb by taking event->mmap_mutex; otherwise
4660 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4662 mutex_lock(&event->mmap_mutex);
4665 events = atomic_xchg(&rb->poll, 0);
4666 mutex_unlock(&event->mmap_mutex);
4670 static void _perf_event_reset(struct perf_event *event)
4672 (void)perf_event_read(event, false);
4673 local64_set(&event->count, 0);
4674 perf_event_update_userpage(event);
4678 * Holding the top-level event's child_mutex means that any
4679 * descendant process that has inherited this event will block
4680 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4681 * task existence requirements of perf_event_enable/disable.
4683 static void perf_event_for_each_child(struct perf_event *event,
4684 void (*func)(struct perf_event *))
4686 struct perf_event *child;
4688 WARN_ON_ONCE(event->ctx->parent_ctx);
4690 mutex_lock(&event->child_mutex);
4692 list_for_each_entry(child, &event->child_list, child_list)
4694 mutex_unlock(&event->child_mutex);
4697 static void perf_event_for_each(struct perf_event *event,
4698 void (*func)(struct perf_event *))
4700 struct perf_event_context *ctx = event->ctx;
4701 struct perf_event *sibling;
4703 lockdep_assert_held(&ctx->mutex);
4705 event = event->group_leader;
4707 perf_event_for_each_child(event, func);
4708 list_for_each_entry(sibling, &event->sibling_list, group_entry)
4709 perf_event_for_each_child(sibling, func);
4712 static void __perf_event_period(struct perf_event *event,
4713 struct perf_cpu_context *cpuctx,
4714 struct perf_event_context *ctx,
4717 u64 value = *((u64 *)info);
4720 if (event->attr.freq) {
4721 event->attr.sample_freq = value;
4723 event->attr.sample_period = value;
4724 event->hw.sample_period = value;
4727 active = (event->state == PERF_EVENT_STATE_ACTIVE);
4729 perf_pmu_disable(ctx->pmu);
4731 * We could be throttled; unthrottle now to avoid the tick
4732 * trying to unthrottle while we already re-started the event.
4734 if (event->hw.interrupts == MAX_INTERRUPTS) {
4735 event->hw.interrupts = 0;
4736 perf_log_throttle(event, 1);
4738 event->pmu->stop(event, PERF_EF_UPDATE);
4741 local64_set(&event->hw.period_left, 0);
4744 event->pmu->start(event, PERF_EF_RELOAD);
4745 perf_pmu_enable(ctx->pmu);
4749 static int perf_event_check_period(struct perf_event *event, u64 value)
4751 return event->pmu->check_period(event, value);
4754 static int perf_event_period(struct perf_event *event, u64 __user *arg)
4758 if (!is_sampling_event(event))
4761 if (copy_from_user(&value, arg, sizeof(value)))
4767 if (event->attr.freq && value > sysctl_perf_event_sample_rate)
4770 if (perf_event_check_period(event, value))
4773 if (!event->attr.freq && (value & (1ULL << 63)))
4776 event_function_call(event, __perf_event_period, &value);
4781 static const struct file_operations perf_fops;
4783 static inline int perf_fget_light(int fd, struct fd *p)
4785 struct fd f = fdget(fd);
4789 if (f.file->f_op != &perf_fops) {
4797 static int perf_event_set_output(struct perf_event *event,
4798 struct perf_event *output_event);
4799 static int perf_event_set_filter(struct perf_event *event, void __user *arg);
4800 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd);
4802 static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg)
4804 void (*func)(struct perf_event *);
4808 case PERF_EVENT_IOC_ENABLE:
4809 func = _perf_event_enable;
4811 case PERF_EVENT_IOC_DISABLE:
4812 func = _perf_event_disable;
4814 case PERF_EVENT_IOC_RESET:
4815 func = _perf_event_reset;
4818 case PERF_EVENT_IOC_REFRESH:
4819 return _perf_event_refresh(event, arg);
4821 case PERF_EVENT_IOC_PERIOD:
4822 return perf_event_period(event, (u64 __user *)arg);
4824 case PERF_EVENT_IOC_ID:
4826 u64 id = primary_event_id(event);
4828 if (copy_to_user((void __user *)arg, &id, sizeof(id)))
4833 case PERF_EVENT_IOC_SET_OUTPUT:
4837 struct perf_event *output_event;
4839 ret = perf_fget_light(arg, &output);
4842 output_event = output.file->private_data;
4843 ret = perf_event_set_output(event, output_event);
4846 ret = perf_event_set_output(event, NULL);
4851 case PERF_EVENT_IOC_SET_FILTER:
4852 return perf_event_set_filter(event, (void __user *)arg);
4854 case PERF_EVENT_IOC_SET_BPF:
4855 return perf_event_set_bpf_prog(event, arg);
4857 case PERF_EVENT_IOC_PAUSE_OUTPUT: {
4858 struct ring_buffer *rb;
4861 rb = rcu_dereference(event->rb);
4862 if (!rb || !rb->nr_pages) {
4866 rb_toggle_paused(rb, !!arg);
4874 if (flags & PERF_IOC_FLAG_GROUP)
4875 perf_event_for_each(event, func);
4877 perf_event_for_each_child(event, func);
4882 static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
4884 struct perf_event *event = file->private_data;
4885 struct perf_event_context *ctx;
4888 ctx = perf_event_ctx_lock(event);
4889 ret = _perf_ioctl(event, cmd, arg);
4890 perf_event_ctx_unlock(event, ctx);
4895 #ifdef CONFIG_COMPAT
4896 static long perf_compat_ioctl(struct file *file, unsigned int cmd,
4899 switch (_IOC_NR(cmd)) {
4900 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER):
4901 case _IOC_NR(PERF_EVENT_IOC_ID):
4902 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4903 if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
4904 cmd &= ~IOCSIZE_MASK;
4905 cmd |= sizeof(void *) << IOCSIZE_SHIFT;
4909 return perf_ioctl(file, cmd, arg);
4912 # define perf_compat_ioctl NULL
4915 int perf_event_task_enable(void)
4917 struct perf_event_context *ctx;
4918 struct perf_event *event;
4920 mutex_lock(¤t->perf_event_mutex);
4921 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
4922 ctx = perf_event_ctx_lock(event);
4923 perf_event_for_each_child(event, _perf_event_enable);
4924 perf_event_ctx_unlock(event, ctx);
4926 mutex_unlock(¤t->perf_event_mutex);
4931 int perf_event_task_disable(void)
4933 struct perf_event_context *ctx;
4934 struct perf_event *event;
4936 mutex_lock(¤t->perf_event_mutex);
4937 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
4938 ctx = perf_event_ctx_lock(event);
4939 perf_event_for_each_child(event, _perf_event_disable);
4940 perf_event_ctx_unlock(event, ctx);
4942 mutex_unlock(¤t->perf_event_mutex);
4947 static int perf_event_index(struct perf_event *event)
4949 if (event->hw.state & PERF_HES_STOPPED)
4952 if (event->state != PERF_EVENT_STATE_ACTIVE)
4955 return event->pmu->event_idx(event);
4958 static void calc_timer_values(struct perf_event *event,
4965 *now = perf_clock();
4966 ctx_time = event->shadow_ctx_time + *now;
4967 *enabled = ctx_time - event->tstamp_enabled;
4968 *running = ctx_time - event->tstamp_running;
4971 static void perf_event_init_userpage(struct perf_event *event)
4973 struct perf_event_mmap_page *userpg;
4974 struct ring_buffer *rb;
4977 rb = rcu_dereference(event->rb);
4981 userpg = rb->user_page;
4983 /* Allow new userspace to detect that bit 0 is deprecated */
4984 userpg->cap_bit0_is_deprecated = 1;
4985 userpg->size = offsetof(struct perf_event_mmap_page, __reserved);
4986 userpg->data_offset = PAGE_SIZE;
4987 userpg->data_size = perf_data_size(rb);
4993 void __weak arch_perf_update_userpage(
4994 struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now)
4999 * Callers need to ensure there can be no nesting of this function, otherwise
5000 * the seqlock logic goes bad. We can not serialize this because the arch
5001 * code calls this from NMI context.
5003 void perf_event_update_userpage(struct perf_event *event)
5005 struct perf_event_mmap_page *userpg;
5006 struct ring_buffer *rb;
5007 u64 enabled, running, now;
5010 rb = rcu_dereference(event->rb);
5015 * compute total_time_enabled, total_time_running
5016 * based on snapshot values taken when the event
5017 * was last scheduled in.
5019 * we cannot simply called update_context_time()
5020 * because of locking issue as we can be called in
5023 calc_timer_values(event, &now, &enabled, &running);
5025 userpg = rb->user_page;
5027 * Disable preemption so as to not let the corresponding user-space
5028 * spin too long if we get preempted.
5033 userpg->index = perf_event_index(event);
5034 userpg->offset = perf_event_count(event);
5036 userpg->offset -= local64_read(&event->hw.prev_count);
5038 userpg->time_enabled = enabled +
5039 atomic64_read(&event->child_total_time_enabled);
5041 userpg->time_running = running +
5042 atomic64_read(&event->child_total_time_running);
5044 arch_perf_update_userpage(event, userpg, now);
5053 static int perf_mmap_fault(struct vm_fault *vmf)
5055 struct perf_event *event = vmf->vma->vm_file->private_data;
5056 struct ring_buffer *rb;
5057 int ret = VM_FAULT_SIGBUS;
5059 if (vmf->flags & FAULT_FLAG_MKWRITE) {
5060 if (vmf->pgoff == 0)
5066 rb = rcu_dereference(event->rb);
5070 if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
5073 vmf->page = perf_mmap_to_page(rb, vmf->pgoff);
5077 get_page(vmf->page);
5078 vmf->page->mapping = vmf->vma->vm_file->f_mapping;
5079 vmf->page->index = vmf->pgoff;
5088 static void ring_buffer_attach(struct perf_event *event,
5089 struct ring_buffer *rb)
5091 struct ring_buffer *old_rb = NULL;
5092 unsigned long flags;
5096 * Should be impossible, we set this when removing
5097 * event->rb_entry and wait/clear when adding event->rb_entry.
5099 WARN_ON_ONCE(event->rcu_pending);
5102 spin_lock_irqsave(&old_rb->event_lock, flags);
5103 list_del_rcu(&event->rb_entry);
5104 spin_unlock_irqrestore(&old_rb->event_lock, flags);
5106 event->rcu_batches = get_state_synchronize_rcu();
5107 event->rcu_pending = 1;
5111 if (event->rcu_pending) {
5112 cond_synchronize_rcu(event->rcu_batches);
5113 event->rcu_pending = 0;
5116 spin_lock_irqsave(&rb->event_lock, flags);
5117 list_add_rcu(&event->rb_entry, &rb->event_list);
5118 spin_unlock_irqrestore(&rb->event_lock, flags);
5122 * Avoid racing with perf_mmap_close(AUX): stop the event
5123 * before swizzling the event::rb pointer; if it's getting
5124 * unmapped, its aux_mmap_count will be 0 and it won't
5125 * restart. See the comment in __perf_pmu_output_stop().
5127 * Data will inevitably be lost when set_output is done in
5128 * mid-air, but then again, whoever does it like this is
5129 * not in for the data anyway.
5132 perf_event_stop(event, 0);
5134 rcu_assign_pointer(event->rb, rb);
5137 ring_buffer_put(old_rb);
5139 * Since we detached before setting the new rb, so that we
5140 * could attach the new rb, we could have missed a wakeup.
5143 wake_up_all(&event->waitq);
5147 static void ring_buffer_wakeup(struct perf_event *event)
5149 struct ring_buffer *rb;
5152 rb = rcu_dereference(event->rb);
5154 list_for_each_entry_rcu(event, &rb->event_list, rb_entry)
5155 wake_up_all(&event->waitq);
5160 struct ring_buffer *ring_buffer_get(struct perf_event *event)
5162 struct ring_buffer *rb;
5165 rb = rcu_dereference(event->rb);
5167 if (!atomic_inc_not_zero(&rb->refcount))
5175 void ring_buffer_put(struct ring_buffer *rb)
5177 if (!atomic_dec_and_test(&rb->refcount))
5180 WARN_ON_ONCE(!list_empty(&rb->event_list));
5182 call_rcu(&rb->rcu_head, rb_free_rcu);
5185 static void perf_mmap_open(struct vm_area_struct *vma)
5187 struct perf_event *event = vma->vm_file->private_data;
5189 atomic_inc(&event->mmap_count);
5190 atomic_inc(&event->rb->mmap_count);
5193 atomic_inc(&event->rb->aux_mmap_count);
5195 if (event->pmu->event_mapped)
5196 event->pmu->event_mapped(event, vma->vm_mm);
5199 static void perf_pmu_output_stop(struct perf_event *event);
5202 * A buffer can be mmap()ed multiple times; either directly through the same
5203 * event, or through other events by use of perf_event_set_output().
5205 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5206 * the buffer here, where we still have a VM context. This means we need
5207 * to detach all events redirecting to us.
5209 static void perf_mmap_close(struct vm_area_struct *vma)
5211 struct perf_event *event = vma->vm_file->private_data;
5212 struct ring_buffer *rb = ring_buffer_get(event);
5213 struct user_struct *mmap_user = rb->mmap_user;
5214 int mmap_locked = rb->mmap_locked;
5215 unsigned long size = perf_data_size(rb);
5216 bool detach_rest = false;
5218 if (event->pmu->event_unmapped)
5219 event->pmu->event_unmapped(event, vma->vm_mm);
5222 * rb->aux_mmap_count will always drop before rb->mmap_count and
5223 * event->mmap_count, so it is ok to use event->mmap_mutex to
5224 * serialize with perf_mmap here.
5226 if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff &&
5227 atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) {
5229 * Stop all AUX events that are writing to this buffer,
5230 * so that we can free its AUX pages and corresponding PMU
5231 * data. Note that after rb::aux_mmap_count dropped to zero,
5232 * they won't start any more (see perf_aux_output_begin()).
5234 perf_pmu_output_stop(event);
5236 /* now it's safe to free the pages */
5237 atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm);
5238 vma->vm_mm->pinned_vm -= rb->aux_mmap_locked;
5240 /* this has to be the last one */
5242 WARN_ON_ONCE(atomic_read(&rb->aux_refcount));
5244 mutex_unlock(&event->mmap_mutex);
5247 if (atomic_dec_and_test(&rb->mmap_count))
5250 if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
5253 ring_buffer_attach(event, NULL);
5254 mutex_unlock(&event->mmap_mutex);
5256 /* If there's still other mmap()s of this buffer, we're done. */
5261 * No other mmap()s, detach from all other events that might redirect
5262 * into the now unreachable buffer. Somewhat complicated by the
5263 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5267 list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
5268 if (!atomic_long_inc_not_zero(&event->refcount)) {
5270 * This event is en-route to free_event() which will
5271 * detach it and remove it from the list.
5277 mutex_lock(&event->mmap_mutex);
5279 * Check we didn't race with perf_event_set_output() which can
5280 * swizzle the rb from under us while we were waiting to
5281 * acquire mmap_mutex.
5283 * If we find a different rb; ignore this event, a next
5284 * iteration will no longer find it on the list. We have to
5285 * still restart the iteration to make sure we're not now
5286 * iterating the wrong list.
5288 if (event->rb == rb)
5289 ring_buffer_attach(event, NULL);
5291 mutex_unlock(&event->mmap_mutex);
5295 * Restart the iteration; either we're on the wrong list or
5296 * destroyed its integrity by doing a deletion.
5303 * It could be there's still a few 0-ref events on the list; they'll
5304 * get cleaned up by free_event() -- they'll also still have their
5305 * ref on the rb and will free it whenever they are done with it.
5307 * Aside from that, this buffer is 'fully' detached and unmapped,
5308 * undo the VM accounting.
5311 atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm);
5312 vma->vm_mm->pinned_vm -= mmap_locked;
5313 free_uid(mmap_user);
5316 ring_buffer_put(rb); /* could be last */
5319 static const struct vm_operations_struct perf_mmap_vmops = {
5320 .open = perf_mmap_open,
5321 .close = perf_mmap_close, /* non mergable */
5322 .fault = perf_mmap_fault,
5323 .page_mkwrite = perf_mmap_fault,
5326 static int perf_mmap(struct file *file, struct vm_area_struct *vma)
5328 struct perf_event *event = file->private_data;
5329 unsigned long user_locked, user_lock_limit;
5330 struct user_struct *user = current_user();
5331 unsigned long locked, lock_limit;
5332 struct ring_buffer *rb = NULL;
5333 unsigned long vma_size;
5334 unsigned long nr_pages;
5335 long user_extra = 0, extra = 0;
5336 int ret = 0, flags = 0;
5339 * Don't allow mmap() of inherited per-task counters. This would
5340 * create a performance issue due to all children writing to the
5343 if (event->cpu == -1 && event->attr.inherit)
5346 if (!(vma->vm_flags & VM_SHARED))
5349 vma_size = vma->vm_end - vma->vm_start;
5351 if (vma->vm_pgoff == 0) {
5352 nr_pages = (vma_size / PAGE_SIZE) - 1;
5355 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5356 * mapped, all subsequent mappings should have the same size
5357 * and offset. Must be above the normal perf buffer.
5359 u64 aux_offset, aux_size;
5364 nr_pages = vma_size / PAGE_SIZE;
5366 mutex_lock(&event->mmap_mutex);
5373 aux_offset = ACCESS_ONCE(rb->user_page->aux_offset);
5374 aux_size = ACCESS_ONCE(rb->user_page->aux_size);
5376 if (aux_offset < perf_data_size(rb) + PAGE_SIZE)
5379 if (aux_offset != vma->vm_pgoff << PAGE_SHIFT)
5382 /* already mapped with a different offset */
5383 if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff)
5386 if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE)
5389 /* already mapped with a different size */
5390 if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages)
5393 if (!is_power_of_2(nr_pages))
5396 if (!atomic_inc_not_zero(&rb->mmap_count))
5399 if (rb_has_aux(rb)) {
5400 atomic_inc(&rb->aux_mmap_count);
5405 atomic_set(&rb->aux_mmap_count, 1);
5406 user_extra = nr_pages;
5412 * If we have rb pages ensure they're a power-of-two number, so we
5413 * can do bitmasks instead of modulo.
5415 if (nr_pages != 0 && !is_power_of_2(nr_pages))
5418 if (vma_size != PAGE_SIZE * (1 + nr_pages))
5421 WARN_ON_ONCE(event->ctx->parent_ctx);
5423 mutex_lock(&event->mmap_mutex);
5425 if (event->rb->nr_pages != nr_pages) {
5430 if (!atomic_inc_not_zero(&event->rb->mmap_count)) {
5432 * Raced against perf_mmap_close() through
5433 * perf_event_set_output(). Try again, hope for better
5436 mutex_unlock(&event->mmap_mutex);
5443 user_extra = nr_pages + 1;
5446 user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
5449 * Increase the limit linearly with more CPUs:
5451 user_lock_limit *= num_online_cpus();
5453 user_locked = atomic_long_read(&user->locked_vm);
5456 * sysctl_perf_event_mlock may have changed, so that
5457 * user->locked_vm > user_lock_limit
5459 if (user_locked > user_lock_limit)
5460 user_locked = user_lock_limit;
5461 user_locked += user_extra;
5463 if (user_locked > user_lock_limit)
5464 extra = user_locked - user_lock_limit;
5466 lock_limit = rlimit(RLIMIT_MEMLOCK);
5467 lock_limit >>= PAGE_SHIFT;
5468 locked = vma->vm_mm->pinned_vm + extra;
5470 if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
5471 !capable(CAP_IPC_LOCK)) {
5476 WARN_ON(!rb && event->rb);
5478 if (vma->vm_flags & VM_WRITE)
5479 flags |= RING_BUFFER_WRITABLE;
5482 rb = rb_alloc(nr_pages,
5483 event->attr.watermark ? event->attr.wakeup_watermark : 0,
5491 atomic_set(&rb->mmap_count, 1);
5492 rb->mmap_user = get_current_user();
5493 rb->mmap_locked = extra;
5495 ring_buffer_attach(event, rb);
5497 perf_event_init_userpage(event);
5498 perf_event_update_userpage(event);
5500 ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages,
5501 event->attr.aux_watermark, flags);
5503 rb->aux_mmap_locked = extra;
5508 atomic_long_add(user_extra, &user->locked_vm);
5509 vma->vm_mm->pinned_vm += extra;
5511 atomic_inc(&event->mmap_count);
5513 atomic_dec(&rb->mmap_count);
5516 mutex_unlock(&event->mmap_mutex);
5519 * Since pinned accounting is per vm we cannot allow fork() to copy our
5522 vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP;
5523 vma->vm_ops = &perf_mmap_vmops;
5525 if (event->pmu->event_mapped)
5526 event->pmu->event_mapped(event, vma->vm_mm);
5531 static int perf_fasync(int fd, struct file *filp, int on)
5533 struct inode *inode = file_inode(filp);
5534 struct perf_event *event = filp->private_data;
5538 retval = fasync_helper(fd, filp, on, &event->fasync);
5539 inode_unlock(inode);
5547 static const struct file_operations perf_fops = {
5548 .llseek = no_llseek,
5549 .release = perf_release,
5552 .unlocked_ioctl = perf_ioctl,
5553 .compat_ioctl = perf_compat_ioctl,
5555 .fasync = perf_fasync,
5561 * If there's data, ensure we set the poll() state and publish everything
5562 * to user-space before waking everybody up.
5565 static inline struct fasync_struct **perf_event_fasync(struct perf_event *event)
5567 /* only the parent has fasync state */
5569 event = event->parent;
5570 return &event->fasync;
5573 void perf_event_wakeup(struct perf_event *event)
5575 ring_buffer_wakeup(event);
5577 if (event->pending_kill) {
5578 kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill);
5579 event->pending_kill = 0;
5583 static void perf_pending_event(struct irq_work *entry)
5585 struct perf_event *event = container_of(entry,
5586 struct perf_event, pending);
5589 rctx = perf_swevent_get_recursion_context();
5591 * If we 'fail' here, that's OK, it means recursion is already disabled
5592 * and we won't recurse 'further'.
5595 if (event->pending_disable) {
5596 event->pending_disable = 0;
5597 perf_event_disable_local(event);
5600 if (event->pending_wakeup) {
5601 event->pending_wakeup = 0;
5602 perf_event_wakeup(event);
5606 perf_swevent_put_recursion_context(rctx);
5610 * We assume there is only KVM supporting the callbacks.
5611 * Later on, we might change it to a list if there is
5612 * another virtualization implementation supporting the callbacks.
5614 struct perf_guest_info_callbacks *perf_guest_cbs;
5616 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
5618 perf_guest_cbs = cbs;
5621 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
5623 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
5625 perf_guest_cbs = NULL;
5628 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
5631 perf_output_sample_regs(struct perf_output_handle *handle,
5632 struct pt_regs *regs, u64 mask)
5635 DECLARE_BITMAP(_mask, 64);
5637 bitmap_from_u64(_mask, mask);
5638 for_each_set_bit(bit, _mask, sizeof(mask) * BITS_PER_BYTE) {
5641 val = perf_reg_value(regs, bit);
5642 perf_output_put(handle, val);
5646 static void perf_sample_regs_user(struct perf_regs *regs_user,
5647 struct pt_regs *regs,
5648 struct pt_regs *regs_user_copy)
5650 if (user_mode(regs)) {
5651 regs_user->abi = perf_reg_abi(current);
5652 regs_user->regs = regs;
5653 } else if (!(current->flags & PF_KTHREAD)) {
5654 perf_get_regs_user(regs_user, regs, regs_user_copy);
5656 regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
5657 regs_user->regs = NULL;
5661 static void perf_sample_regs_intr(struct perf_regs *regs_intr,
5662 struct pt_regs *regs)
5664 regs_intr->regs = regs;
5665 regs_intr->abi = perf_reg_abi(current);
5670 * Get remaining task size from user stack pointer.
5672 * It'd be better to take stack vma map and limit this more
5673 * precisly, but there's no way to get it safely under interrupt,
5674 * so using TASK_SIZE as limit.
5676 static u64 perf_ustack_task_size(struct pt_regs *regs)
5678 unsigned long addr = perf_user_stack_pointer(regs);
5680 if (!addr || addr >= TASK_SIZE)
5683 return TASK_SIZE - addr;
5687 perf_sample_ustack_size(u16 stack_size, u16 header_size,
5688 struct pt_regs *regs)
5692 /* No regs, no stack pointer, no dump. */
5697 * Check if we fit in with the requested stack size into the:
5699 * If we don't, we limit the size to the TASK_SIZE.
5701 * - remaining sample size
5702 * If we don't, we customize the stack size to
5703 * fit in to the remaining sample size.
5706 task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs));
5707 stack_size = min(stack_size, (u16) task_size);
5709 /* Current header size plus static size and dynamic size. */
5710 header_size += 2 * sizeof(u64);
5712 /* Do we fit in with the current stack dump size? */
5713 if ((u16) (header_size + stack_size) < header_size) {
5715 * If we overflow the maximum size for the sample,
5716 * we customize the stack dump size to fit in.
5718 stack_size = USHRT_MAX - header_size - sizeof(u64);
5719 stack_size = round_up(stack_size, sizeof(u64));
5726 perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size,
5727 struct pt_regs *regs)
5729 /* Case of a kernel thread, nothing to dump */
5732 perf_output_put(handle, size);
5742 * - the size requested by user or the best one we can fit
5743 * in to the sample max size
5745 * - user stack dump data
5747 * - the actual dumped size
5751 perf_output_put(handle, dump_size);
5754 sp = perf_user_stack_pointer(regs);
5757 rem = __output_copy_user(handle, (void *) sp, dump_size);
5759 dyn_size = dump_size - rem;
5761 perf_output_skip(handle, rem);
5764 perf_output_put(handle, dyn_size);
5768 static void __perf_event_header__init_id(struct perf_event_header *header,
5769 struct perf_sample_data *data,
5770 struct perf_event *event)
5772 u64 sample_type = event->attr.sample_type;
5774 data->type = sample_type;
5775 header->size += event->id_header_size;
5777 if (sample_type & PERF_SAMPLE_TID) {
5778 /* namespace issues */
5779 data->tid_entry.pid = perf_event_pid(event, current);
5780 data->tid_entry.tid = perf_event_tid(event, current);
5783 if (sample_type & PERF_SAMPLE_TIME)
5784 data->time = perf_event_clock(event);
5786 if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER))
5787 data->id = primary_event_id(event);
5789 if (sample_type & PERF_SAMPLE_STREAM_ID)
5790 data->stream_id = event->id;
5792 if (sample_type & PERF_SAMPLE_CPU) {
5793 data->cpu_entry.cpu = raw_smp_processor_id();
5794 data->cpu_entry.reserved = 0;
5798 void perf_event_header__init_id(struct perf_event_header *header,
5799 struct perf_sample_data *data,
5800 struct perf_event *event)
5802 if (event->attr.sample_id_all)
5803 __perf_event_header__init_id(header, data, event);
5806 static void __perf_event__output_id_sample(struct perf_output_handle *handle,
5807 struct perf_sample_data *data)
5809 u64 sample_type = data->type;
5811 if (sample_type & PERF_SAMPLE_TID)
5812 perf_output_put(handle, data->tid_entry);
5814 if (sample_type & PERF_SAMPLE_TIME)
5815 perf_output_put(handle, data->time);
5817 if (sample_type & PERF_SAMPLE_ID)
5818 perf_output_put(handle, data->id);
5820 if (sample_type & PERF_SAMPLE_STREAM_ID)
5821 perf_output_put(handle, data->stream_id);
5823 if (sample_type & PERF_SAMPLE_CPU)
5824 perf_output_put(handle, data->cpu_entry);
5826 if (sample_type & PERF_SAMPLE_IDENTIFIER)
5827 perf_output_put(handle, data->id);
5830 void perf_event__output_id_sample(struct perf_event *event,
5831 struct perf_output_handle *handle,
5832 struct perf_sample_data *sample)
5834 if (event->attr.sample_id_all)
5835 __perf_event__output_id_sample(handle, sample);
5838 static void perf_output_read_one(struct perf_output_handle *handle,
5839 struct perf_event *event,
5840 u64 enabled, u64 running)
5842 u64 read_format = event->attr.read_format;
5846 values[n++] = perf_event_count(event);
5847 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
5848 values[n++] = enabled +
5849 atomic64_read(&event->child_total_time_enabled);
5851 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
5852 values[n++] = running +
5853 atomic64_read(&event->child_total_time_running);
5855 if (read_format & PERF_FORMAT_ID)
5856 values[n++] = primary_event_id(event);
5858 __output_copy(handle, values, n * sizeof(u64));
5861 static void perf_output_read_group(struct perf_output_handle *handle,
5862 struct perf_event *event,
5863 u64 enabled, u64 running)
5865 struct perf_event *leader = event->group_leader, *sub;
5866 u64 read_format = event->attr.read_format;
5870 values[n++] = 1 + leader->nr_siblings;
5872 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
5873 values[n++] = enabled;
5875 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
5876 values[n++] = running;
5878 if ((leader != event) &&
5879 (leader->state == PERF_EVENT_STATE_ACTIVE))
5880 leader->pmu->read(leader);
5882 values[n++] = perf_event_count(leader);
5883 if (read_format & PERF_FORMAT_ID)
5884 values[n++] = primary_event_id(leader);
5886 __output_copy(handle, values, n * sizeof(u64));
5888 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
5891 if ((sub != event) &&
5892 (sub->state == PERF_EVENT_STATE_ACTIVE))
5893 sub->pmu->read(sub);
5895 values[n++] = perf_event_count(sub);
5896 if (read_format & PERF_FORMAT_ID)
5897 values[n++] = primary_event_id(sub);
5899 __output_copy(handle, values, n * sizeof(u64));
5903 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5904 PERF_FORMAT_TOTAL_TIME_RUNNING)
5907 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
5909 * The problem is that its both hard and excessively expensive to iterate the
5910 * child list, not to mention that its impossible to IPI the children running
5911 * on another CPU, from interrupt/NMI context.
5913 static void perf_output_read(struct perf_output_handle *handle,
5914 struct perf_event *event)
5916 u64 enabled = 0, running = 0, now;
5917 u64 read_format = event->attr.read_format;
5920 * compute total_time_enabled, total_time_running
5921 * based on snapshot values taken when the event
5922 * was last scheduled in.
5924 * we cannot simply called update_context_time()
5925 * because of locking issue as we are called in
5928 if (read_format & PERF_FORMAT_TOTAL_TIMES)
5929 calc_timer_values(event, &now, &enabled, &running);
5931 if (event->attr.read_format & PERF_FORMAT_GROUP)
5932 perf_output_read_group(handle, event, enabled, running);
5934 perf_output_read_one(handle, event, enabled, running);
5937 void perf_output_sample(struct perf_output_handle *handle,
5938 struct perf_event_header *header,
5939 struct perf_sample_data *data,
5940 struct perf_event *event)
5942 u64 sample_type = data->type;
5944 perf_output_put(handle, *header);
5946 if (sample_type & PERF_SAMPLE_IDENTIFIER)
5947 perf_output_put(handle, data->id);
5949 if (sample_type & PERF_SAMPLE_IP)
5950 perf_output_put(handle, data->ip);
5952 if (sample_type & PERF_SAMPLE_TID)
5953 perf_output_put(handle, data->tid_entry);
5955 if (sample_type & PERF_SAMPLE_TIME)
5956 perf_output_put(handle, data->time);
5958 if (sample_type & PERF_SAMPLE_ADDR)
5959 perf_output_put(handle, data->addr);
5961 if (sample_type & PERF_SAMPLE_ID)
5962 perf_output_put(handle, data->id);
5964 if (sample_type & PERF_SAMPLE_STREAM_ID)
5965 perf_output_put(handle, data->stream_id);
5967 if (sample_type & PERF_SAMPLE_CPU)
5968 perf_output_put(handle, data->cpu_entry);
5970 if (sample_type & PERF_SAMPLE_PERIOD)
5971 perf_output_put(handle, data->period);
5973 if (sample_type & PERF_SAMPLE_READ)
5974 perf_output_read(handle, event);
5976 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
5977 if (data->callchain) {
5980 if (data->callchain)
5981 size += data->callchain->nr;
5983 size *= sizeof(u64);
5985 __output_copy(handle, data->callchain, size);
5988 perf_output_put(handle, nr);
5992 if (sample_type & PERF_SAMPLE_RAW) {
5993 struct perf_raw_record *raw = data->raw;
5996 struct perf_raw_frag *frag = &raw->frag;
5998 perf_output_put(handle, raw->size);
6001 __output_custom(handle, frag->copy,
6002 frag->data, frag->size);
6004 __output_copy(handle, frag->data,
6007 if (perf_raw_frag_last(frag))
6012 __output_skip(handle, NULL, frag->pad);
6018 .size = sizeof(u32),
6021 perf_output_put(handle, raw);
6025 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
6026 if (data->br_stack) {
6029 size = data->br_stack->nr
6030 * sizeof(struct perf_branch_entry);
6032 perf_output_put(handle, data->br_stack->nr);
6033 perf_output_copy(handle, data->br_stack->entries, size);
6036 * we always store at least the value of nr
6039 perf_output_put(handle, nr);
6043 if (sample_type & PERF_SAMPLE_REGS_USER) {
6044 u64 abi = data->regs_user.abi;
6047 * If there are no regs to dump, notice it through
6048 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6050 perf_output_put(handle, abi);
6053 u64 mask = event->attr.sample_regs_user;
6054 perf_output_sample_regs(handle,
6055 data->regs_user.regs,
6060 if (sample_type & PERF_SAMPLE_STACK_USER) {
6061 perf_output_sample_ustack(handle,
6062 data->stack_user_size,
6063 data->regs_user.regs);
6066 if (sample_type & PERF_SAMPLE_WEIGHT)
6067 perf_output_put(handle, data->weight);
6069 if (sample_type & PERF_SAMPLE_DATA_SRC)
6070 perf_output_put(handle, data->data_src.val);
6072 if (sample_type & PERF_SAMPLE_TRANSACTION)
6073 perf_output_put(handle, data->txn);
6075 if (sample_type & PERF_SAMPLE_REGS_INTR) {
6076 u64 abi = data->regs_intr.abi;
6078 * If there are no regs to dump, notice it through
6079 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6081 perf_output_put(handle, abi);
6084 u64 mask = event->attr.sample_regs_intr;
6086 perf_output_sample_regs(handle,
6087 data->regs_intr.regs,
6092 if (sample_type & PERF_SAMPLE_PHYS_ADDR)
6093 perf_output_put(handle, data->phys_addr);
6095 if (!event->attr.watermark) {
6096 int wakeup_events = event->attr.wakeup_events;
6098 if (wakeup_events) {
6099 struct ring_buffer *rb = handle->rb;
6100 int events = local_inc_return(&rb->events);
6102 if (events >= wakeup_events) {
6103 local_sub(wakeup_events, &rb->events);
6104 local_inc(&rb->wakeup);
6110 static u64 perf_virt_to_phys(u64 virt)
6113 struct page *p = NULL;
6118 if (virt >= TASK_SIZE) {
6119 /* If it's vmalloc()d memory, leave phys_addr as 0 */
6120 if (virt_addr_valid((void *)(uintptr_t)virt) &&
6121 !(virt >= VMALLOC_START && virt < VMALLOC_END))
6122 phys_addr = (u64)virt_to_phys((void *)(uintptr_t)virt);
6125 * Walking the pages tables for user address.
6126 * Interrupts are disabled, so it prevents any tear down
6127 * of the page tables.
6128 * Try IRQ-safe __get_user_pages_fast first.
6129 * If failed, leave phys_addr as 0.
6131 if (current->mm != NULL) {
6132 pagefault_disable();
6133 if (__get_user_pages_fast(virt, 1, 0, &p) == 1)
6134 phys_addr = page_to_phys(p) + virt % PAGE_SIZE;
6145 void perf_prepare_sample(struct perf_event_header *header,
6146 struct perf_sample_data *data,
6147 struct perf_event *event,
6148 struct pt_regs *regs)
6150 u64 sample_type = event->attr.sample_type;
6152 header->type = PERF_RECORD_SAMPLE;
6153 header->size = sizeof(*header) + event->header_size;
6156 header->misc |= perf_misc_flags(regs);
6158 __perf_event_header__init_id(header, data, event);
6160 if (sample_type & PERF_SAMPLE_IP)
6161 data->ip = perf_instruction_pointer(regs);
6163 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
6166 data->callchain = perf_callchain(event, regs);
6168 if (data->callchain)
6169 size += data->callchain->nr;
6171 header->size += size * sizeof(u64);
6174 if (sample_type & PERF_SAMPLE_RAW) {
6175 struct perf_raw_record *raw = data->raw;
6179 struct perf_raw_frag *frag = &raw->frag;
6184 if (perf_raw_frag_last(frag))
6189 size = round_up(sum + sizeof(u32), sizeof(u64));
6190 raw->size = size - sizeof(u32);
6191 frag->pad = raw->size - sum;
6196 header->size += size;
6199 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
6200 int size = sizeof(u64); /* nr */
6201 if (data->br_stack) {
6202 size += data->br_stack->nr
6203 * sizeof(struct perf_branch_entry);
6205 header->size += size;
6208 if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER))
6209 perf_sample_regs_user(&data->regs_user, regs,
6210 &data->regs_user_copy);
6212 if (sample_type & PERF_SAMPLE_REGS_USER) {
6213 /* regs dump ABI info */
6214 int size = sizeof(u64);
6216 if (data->regs_user.regs) {
6217 u64 mask = event->attr.sample_regs_user;
6218 size += hweight64(mask) * sizeof(u64);
6221 header->size += size;
6224 if (sample_type & PERF_SAMPLE_STACK_USER) {
6226 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6227 * processed as the last one or have additional check added
6228 * in case new sample type is added, because we could eat
6229 * up the rest of the sample size.
6231 u16 stack_size = event->attr.sample_stack_user;
6232 u16 size = sizeof(u64);
6234 stack_size = perf_sample_ustack_size(stack_size, header->size,
6235 data->regs_user.regs);
6238 * If there is something to dump, add space for the dump
6239 * itself and for the field that tells the dynamic size,
6240 * which is how many have been actually dumped.
6243 size += sizeof(u64) + stack_size;
6245 data->stack_user_size = stack_size;
6246 header->size += size;
6249 if (sample_type & PERF_SAMPLE_REGS_INTR) {
6250 /* regs dump ABI info */
6251 int size = sizeof(u64);
6253 perf_sample_regs_intr(&data->regs_intr, regs);
6255 if (data->regs_intr.regs) {
6256 u64 mask = event->attr.sample_regs_intr;
6258 size += hweight64(mask) * sizeof(u64);
6261 header->size += size;
6264 if (sample_type & PERF_SAMPLE_PHYS_ADDR)
6265 data->phys_addr = perf_virt_to_phys(data->addr);
6268 static void __always_inline
6269 __perf_event_output(struct perf_event *event,
6270 struct perf_sample_data *data,
6271 struct pt_regs *regs,
6272 int (*output_begin)(struct perf_output_handle *,
6273 struct perf_event *,
6276 struct perf_output_handle handle;
6277 struct perf_event_header header;
6279 /* protect the callchain buffers */
6282 perf_prepare_sample(&header, data, event, regs);
6284 if (output_begin(&handle, event, header.size))
6287 perf_output_sample(&handle, &header, data, event);
6289 perf_output_end(&handle);
6296 perf_event_output_forward(struct perf_event *event,
6297 struct perf_sample_data *data,
6298 struct pt_regs *regs)
6300 __perf_event_output(event, data, regs, perf_output_begin_forward);
6304 perf_event_output_backward(struct perf_event *event,
6305 struct perf_sample_data *data,
6306 struct pt_regs *regs)
6308 __perf_event_output(event, data, regs, perf_output_begin_backward);
6312 perf_event_output(struct perf_event *event,
6313 struct perf_sample_data *data,
6314 struct pt_regs *regs)
6316 __perf_event_output(event, data, regs, perf_output_begin);
6323 struct perf_read_event {
6324 struct perf_event_header header;
6331 perf_event_read_event(struct perf_event *event,
6332 struct task_struct *task)
6334 struct perf_output_handle handle;
6335 struct perf_sample_data sample;
6336 struct perf_read_event read_event = {
6338 .type = PERF_RECORD_READ,
6340 .size = sizeof(read_event) + event->read_size,
6342 .pid = perf_event_pid(event, task),
6343 .tid = perf_event_tid(event, task),
6347 perf_event_header__init_id(&read_event.header, &sample, event);
6348 ret = perf_output_begin(&handle, event, read_event.header.size);
6352 perf_output_put(&handle, read_event);
6353 perf_output_read(&handle, event);
6354 perf_event__output_id_sample(event, &handle, &sample);
6356 perf_output_end(&handle);
6359 typedef void (perf_iterate_f)(struct perf_event *event, void *data);
6362 perf_iterate_ctx(struct perf_event_context *ctx,
6363 perf_iterate_f output,
6364 void *data, bool all)
6366 struct perf_event *event;
6368 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
6370 if (event->state < PERF_EVENT_STATE_INACTIVE)
6372 if (!event_filter_match(event))
6376 output(event, data);
6380 static void perf_iterate_sb_cpu(perf_iterate_f output, void *data)
6382 struct pmu_event_list *pel = this_cpu_ptr(&pmu_sb_events);
6383 struct perf_event *event;
6385 list_for_each_entry_rcu(event, &pel->list, sb_list) {
6387 * Skip events that are not fully formed yet; ensure that
6388 * if we observe event->ctx, both event and ctx will be
6389 * complete enough. See perf_install_in_context().
6391 if (!smp_load_acquire(&event->ctx))
6394 if (event->state < PERF_EVENT_STATE_INACTIVE)
6396 if (!event_filter_match(event))
6398 output(event, data);
6403 * Iterate all events that need to receive side-band events.
6405 * For new callers; ensure that account_pmu_sb_event() includes
6406 * your event, otherwise it might not get delivered.
6409 perf_iterate_sb(perf_iterate_f output, void *data,
6410 struct perf_event_context *task_ctx)
6412 struct perf_event_context *ctx;
6419 * If we have task_ctx != NULL we only notify the task context itself.
6420 * The task_ctx is set only for EXIT events before releasing task
6424 perf_iterate_ctx(task_ctx, output, data, false);
6428 perf_iterate_sb_cpu(output, data);
6430 for_each_task_context_nr(ctxn) {
6431 ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
6433 perf_iterate_ctx(ctx, output, data, false);
6441 * Clear all file-based filters at exec, they'll have to be
6442 * re-instated when/if these objects are mmapped again.
6444 static void perf_event_addr_filters_exec(struct perf_event *event, void *data)
6446 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
6447 struct perf_addr_filter *filter;
6448 unsigned int restart = 0, count = 0;
6449 unsigned long flags;
6451 if (!has_addr_filter(event))
6454 raw_spin_lock_irqsave(&ifh->lock, flags);
6455 list_for_each_entry(filter, &ifh->list, entry) {
6456 if (filter->path.dentry) {
6457 event->addr_filters_offs[count] = 0;
6465 event->addr_filters_gen++;
6466 raw_spin_unlock_irqrestore(&ifh->lock, flags);
6469 perf_event_stop(event, 1);
6472 void perf_event_exec(void)
6474 struct perf_event_context *ctx;
6478 for_each_task_context_nr(ctxn) {
6479 ctx = current->perf_event_ctxp[ctxn];
6483 perf_event_enable_on_exec(ctxn);
6485 perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL,
6491 struct remote_output {
6492 struct ring_buffer *rb;
6496 static void __perf_event_output_stop(struct perf_event *event, void *data)
6498 struct perf_event *parent = event->parent;
6499 struct remote_output *ro = data;
6500 struct ring_buffer *rb = ro->rb;
6501 struct stop_event_data sd = {
6505 if (!has_aux(event))
6512 * In case of inheritance, it will be the parent that links to the
6513 * ring-buffer, but it will be the child that's actually using it.
6515 * We are using event::rb to determine if the event should be stopped,
6516 * however this may race with ring_buffer_attach() (through set_output),
6517 * which will make us skip the event that actually needs to be stopped.
6518 * So ring_buffer_attach() has to stop an aux event before re-assigning
6521 if (rcu_dereference(parent->rb) == rb)
6522 ro->err = __perf_event_stop(&sd);
6525 static int __perf_pmu_output_stop(void *info)
6527 struct perf_event *event = info;
6528 struct pmu *pmu = event->pmu;
6529 struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
6530 struct remote_output ro = {
6535 perf_iterate_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false);
6536 if (cpuctx->task_ctx)
6537 perf_iterate_ctx(cpuctx->task_ctx, __perf_event_output_stop,
6544 static void perf_pmu_output_stop(struct perf_event *event)
6546 struct perf_event *iter;
6551 list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) {
6553 * For per-CPU events, we need to make sure that neither they
6554 * nor their children are running; for cpu==-1 events it's
6555 * sufficient to stop the event itself if it's active, since
6556 * it can't have children.
6560 cpu = READ_ONCE(iter->oncpu);
6565 err = cpu_function_call(cpu, __perf_pmu_output_stop, event);
6566 if (err == -EAGAIN) {
6575 * task tracking -- fork/exit
6577 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6580 struct perf_task_event {
6581 struct task_struct *task;
6582 struct perf_event_context *task_ctx;
6585 struct perf_event_header header;
6595 static int perf_event_task_match(struct perf_event *event)
6597 return event->attr.comm || event->attr.mmap ||
6598 event->attr.mmap2 || event->attr.mmap_data ||
6602 static void perf_event_task_output(struct perf_event *event,
6605 struct perf_task_event *task_event = data;
6606 struct perf_output_handle handle;
6607 struct perf_sample_data sample;
6608 struct task_struct *task = task_event->task;
6609 int ret, size = task_event->event_id.header.size;
6611 if (!perf_event_task_match(event))
6614 perf_event_header__init_id(&task_event->event_id.header, &sample, event);
6616 ret = perf_output_begin(&handle, event,
6617 task_event->event_id.header.size);
6621 task_event->event_id.pid = perf_event_pid(event, task);
6622 task_event->event_id.tid = perf_event_tid(event, task);
6624 if (task_event->event_id.header.type == PERF_RECORD_EXIT) {
6625 task_event->event_id.ppid = perf_event_pid(event,
6627 task_event->event_id.ptid = perf_event_pid(event,
6629 } else { /* PERF_RECORD_FORK */
6630 task_event->event_id.ppid = perf_event_pid(event, current);
6631 task_event->event_id.ptid = perf_event_tid(event, current);
6634 task_event->event_id.time = perf_event_clock(event);
6636 perf_output_put(&handle, task_event->event_id);
6638 perf_event__output_id_sample(event, &handle, &sample);
6640 perf_output_end(&handle);
6642 task_event->event_id.header.size = size;
6645 static void perf_event_task(struct task_struct *task,
6646 struct perf_event_context *task_ctx,
6649 struct perf_task_event task_event;
6651 if (!atomic_read(&nr_comm_events) &&
6652 !atomic_read(&nr_mmap_events) &&
6653 !atomic_read(&nr_task_events))
6656 task_event = (struct perf_task_event){
6658 .task_ctx = task_ctx,
6661 .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
6663 .size = sizeof(task_event.event_id),
6673 perf_iterate_sb(perf_event_task_output,
6678 void perf_event_fork(struct task_struct *task)
6680 perf_event_task(task, NULL, 1);
6681 perf_event_namespaces(task);
6688 struct perf_comm_event {
6689 struct task_struct *task;
6694 struct perf_event_header header;
6701 static int perf_event_comm_match(struct perf_event *event)
6703 return event->attr.comm;
6706 static void perf_event_comm_output(struct perf_event *event,
6709 struct perf_comm_event *comm_event = data;
6710 struct perf_output_handle handle;
6711 struct perf_sample_data sample;
6712 int size = comm_event->event_id.header.size;
6715 if (!perf_event_comm_match(event))
6718 perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
6719 ret = perf_output_begin(&handle, event,
6720 comm_event->event_id.header.size);
6725 comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
6726 comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
6728 perf_output_put(&handle, comm_event->event_id);
6729 __output_copy(&handle, comm_event->comm,
6730 comm_event->comm_size);
6732 perf_event__output_id_sample(event, &handle, &sample);
6734 perf_output_end(&handle);
6736 comm_event->event_id.header.size = size;
6739 static void perf_event_comm_event(struct perf_comm_event *comm_event)
6741 char comm[TASK_COMM_LEN];
6744 memset(comm, 0, sizeof(comm));
6745 strlcpy(comm, comm_event->task->comm, sizeof(comm));
6746 size = ALIGN(strlen(comm)+1, sizeof(u64));
6748 comm_event->comm = comm;
6749 comm_event->comm_size = size;
6751 comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
6753 perf_iterate_sb(perf_event_comm_output,
6758 void perf_event_comm(struct task_struct *task, bool exec)
6760 struct perf_comm_event comm_event;
6762 if (!atomic_read(&nr_comm_events))
6765 comm_event = (struct perf_comm_event){
6771 .type = PERF_RECORD_COMM,
6772 .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0,
6780 perf_event_comm_event(&comm_event);
6784 * namespaces tracking
6787 struct perf_namespaces_event {
6788 struct task_struct *task;
6791 struct perf_event_header header;
6796 struct perf_ns_link_info link_info[NR_NAMESPACES];
6800 static int perf_event_namespaces_match(struct perf_event *event)
6802 return event->attr.namespaces;
6805 static void perf_event_namespaces_output(struct perf_event *event,
6808 struct perf_namespaces_event *namespaces_event = data;
6809 struct perf_output_handle handle;
6810 struct perf_sample_data sample;
6811 u16 header_size = namespaces_event->event_id.header.size;
6814 if (!perf_event_namespaces_match(event))
6817 perf_event_header__init_id(&namespaces_event->event_id.header,
6819 ret = perf_output_begin(&handle, event,
6820 namespaces_event->event_id.header.size);
6824 namespaces_event->event_id.pid = perf_event_pid(event,
6825 namespaces_event->task);
6826 namespaces_event->event_id.tid = perf_event_tid(event,
6827 namespaces_event->task);
6829 perf_output_put(&handle, namespaces_event->event_id);
6831 perf_event__output_id_sample(event, &handle, &sample);
6833 perf_output_end(&handle);
6835 namespaces_event->event_id.header.size = header_size;
6838 static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info,
6839 struct task_struct *task,
6840 const struct proc_ns_operations *ns_ops)
6842 struct path ns_path;
6843 struct inode *ns_inode;
6846 error = ns_get_path(&ns_path, task, ns_ops);
6848 ns_inode = ns_path.dentry->d_inode;
6849 ns_link_info->dev = new_encode_dev(ns_inode->i_sb->s_dev);
6850 ns_link_info->ino = ns_inode->i_ino;
6855 void perf_event_namespaces(struct task_struct *task)
6857 struct perf_namespaces_event namespaces_event;
6858 struct perf_ns_link_info *ns_link_info;
6860 if (!atomic_read(&nr_namespaces_events))
6863 namespaces_event = (struct perf_namespaces_event){
6867 .type = PERF_RECORD_NAMESPACES,
6869 .size = sizeof(namespaces_event.event_id),
6873 .nr_namespaces = NR_NAMESPACES,
6874 /* .link_info[NR_NAMESPACES] */
6878 ns_link_info = namespaces_event.event_id.link_info;
6880 perf_fill_ns_link_info(&ns_link_info[MNT_NS_INDEX],
6881 task, &mntns_operations);
6883 #ifdef CONFIG_USER_NS
6884 perf_fill_ns_link_info(&ns_link_info[USER_NS_INDEX],
6885 task, &userns_operations);
6887 #ifdef CONFIG_NET_NS
6888 perf_fill_ns_link_info(&ns_link_info[NET_NS_INDEX],
6889 task, &netns_operations);
6891 #ifdef CONFIG_UTS_NS
6892 perf_fill_ns_link_info(&ns_link_info[UTS_NS_INDEX],
6893 task, &utsns_operations);
6895 #ifdef CONFIG_IPC_NS
6896 perf_fill_ns_link_info(&ns_link_info[IPC_NS_INDEX],
6897 task, &ipcns_operations);
6899 #ifdef CONFIG_PID_NS
6900 perf_fill_ns_link_info(&ns_link_info[PID_NS_INDEX],
6901 task, &pidns_operations);
6903 #ifdef CONFIG_CGROUPS
6904 perf_fill_ns_link_info(&ns_link_info[CGROUP_NS_INDEX],
6905 task, &cgroupns_operations);
6908 perf_iterate_sb(perf_event_namespaces_output,
6917 struct perf_mmap_event {
6918 struct vm_area_struct *vma;
6920 const char *file_name;
6928 struct perf_event_header header;
6938 static int perf_event_mmap_match(struct perf_event *event,
6941 struct perf_mmap_event *mmap_event = data;
6942 struct vm_area_struct *vma = mmap_event->vma;
6943 int executable = vma->vm_flags & VM_EXEC;
6945 return (!executable && event->attr.mmap_data) ||
6946 (executable && (event->attr.mmap || event->attr.mmap2));
6949 static void perf_event_mmap_output(struct perf_event *event,
6952 struct perf_mmap_event *mmap_event = data;
6953 struct perf_output_handle handle;
6954 struct perf_sample_data sample;
6955 int size = mmap_event->event_id.header.size;
6956 u32 type = mmap_event->event_id.header.type;
6959 if (!perf_event_mmap_match(event, data))
6962 if (event->attr.mmap2) {
6963 mmap_event->event_id.header.type = PERF_RECORD_MMAP2;
6964 mmap_event->event_id.header.size += sizeof(mmap_event->maj);
6965 mmap_event->event_id.header.size += sizeof(mmap_event->min);
6966 mmap_event->event_id.header.size += sizeof(mmap_event->ino);
6967 mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation);
6968 mmap_event->event_id.header.size += sizeof(mmap_event->prot);
6969 mmap_event->event_id.header.size += sizeof(mmap_event->flags);
6972 perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
6973 ret = perf_output_begin(&handle, event,
6974 mmap_event->event_id.header.size);
6978 mmap_event->event_id.pid = perf_event_pid(event, current);
6979 mmap_event->event_id.tid = perf_event_tid(event, current);
6981 perf_output_put(&handle, mmap_event->event_id);
6983 if (event->attr.mmap2) {
6984 perf_output_put(&handle, mmap_event->maj);
6985 perf_output_put(&handle, mmap_event->min);
6986 perf_output_put(&handle, mmap_event->ino);
6987 perf_output_put(&handle, mmap_event->ino_generation);
6988 perf_output_put(&handle, mmap_event->prot);
6989 perf_output_put(&handle, mmap_event->flags);
6992 __output_copy(&handle, mmap_event->file_name,
6993 mmap_event->file_size);
6995 perf_event__output_id_sample(event, &handle, &sample);
6997 perf_output_end(&handle);
6999 mmap_event->event_id.header.size = size;
7000 mmap_event->event_id.header.type = type;
7003 static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
7005 struct vm_area_struct *vma = mmap_event->vma;
7006 struct file *file = vma->vm_file;
7007 int maj = 0, min = 0;
7008 u64 ino = 0, gen = 0;
7009 u32 prot = 0, flags = 0;
7015 if (vma->vm_flags & VM_READ)
7017 if (vma->vm_flags & VM_WRITE)
7019 if (vma->vm_flags & VM_EXEC)
7022 if (vma->vm_flags & VM_MAYSHARE)
7025 flags = MAP_PRIVATE;
7027 if (vma->vm_flags & VM_DENYWRITE)
7028 flags |= MAP_DENYWRITE;
7029 if (vma->vm_flags & VM_MAYEXEC)
7030 flags |= MAP_EXECUTABLE;
7031 if (vma->vm_flags & VM_LOCKED)
7032 flags |= MAP_LOCKED;
7033 if (vma->vm_flags & VM_HUGETLB)
7034 flags |= MAP_HUGETLB;
7037 struct inode *inode;
7040 buf = kmalloc(PATH_MAX, GFP_KERNEL);
7046 * d_path() works from the end of the rb backwards, so we
7047 * need to add enough zero bytes after the string to handle
7048 * the 64bit alignment we do later.
7050 name = file_path(file, buf, PATH_MAX - sizeof(u64));
7055 inode = file_inode(vma->vm_file);
7056 dev = inode->i_sb->s_dev;
7058 gen = inode->i_generation;
7064 if (vma->vm_ops && vma->vm_ops->name) {
7065 name = (char *) vma->vm_ops->name(vma);
7070 name = (char *)arch_vma_name(vma);
7074 if (vma->vm_start <= vma->vm_mm->start_brk &&
7075 vma->vm_end >= vma->vm_mm->brk) {
7079 if (vma->vm_start <= vma->vm_mm->start_stack &&
7080 vma->vm_end >= vma->vm_mm->start_stack) {
7090 strlcpy(tmp, name, sizeof(tmp));
7094 * Since our buffer works in 8 byte units we need to align our string
7095 * size to a multiple of 8. However, we must guarantee the tail end is
7096 * zero'd out to avoid leaking random bits to userspace.
7098 size = strlen(name)+1;
7099 while (!IS_ALIGNED(size, sizeof(u64)))
7100 name[size++] = '\0';
7102 mmap_event->file_name = name;
7103 mmap_event->file_size = size;
7104 mmap_event->maj = maj;
7105 mmap_event->min = min;
7106 mmap_event->ino = ino;
7107 mmap_event->ino_generation = gen;
7108 mmap_event->prot = prot;
7109 mmap_event->flags = flags;
7111 if (!(vma->vm_flags & VM_EXEC))
7112 mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;
7114 mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
7116 perf_iterate_sb(perf_event_mmap_output,
7124 * Check whether inode and address range match filter criteria.
7126 static bool perf_addr_filter_match(struct perf_addr_filter *filter,
7127 struct file *file, unsigned long offset,
7130 /* d_inode(NULL) won't be equal to any mapped user-space file */
7131 if (!filter->path.dentry)
7134 if (d_inode(filter->path.dentry) != file_inode(file))
7137 if (filter->offset > offset + size)
7140 if (filter->offset + filter->size < offset)
7146 static void __perf_addr_filters_adjust(struct perf_event *event, void *data)
7148 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
7149 struct vm_area_struct *vma = data;
7150 unsigned long off = vma->vm_pgoff << PAGE_SHIFT, flags;
7151 struct file *file = vma->vm_file;
7152 struct perf_addr_filter *filter;
7153 unsigned int restart = 0, count = 0;
7155 if (!has_addr_filter(event))
7161 raw_spin_lock_irqsave(&ifh->lock, flags);
7162 list_for_each_entry(filter, &ifh->list, entry) {
7163 if (perf_addr_filter_match(filter, file, off,
7164 vma->vm_end - vma->vm_start)) {
7165 event->addr_filters_offs[count] = vma->vm_start;
7173 event->addr_filters_gen++;
7174 raw_spin_unlock_irqrestore(&ifh->lock, flags);
7177 perf_event_stop(event, 1);
7181 * Adjust all task's events' filters to the new vma
7183 static void perf_addr_filters_adjust(struct vm_area_struct *vma)
7185 struct perf_event_context *ctx;
7189 * Data tracing isn't supported yet and as such there is no need
7190 * to keep track of anything that isn't related to executable code:
7192 if (!(vma->vm_flags & VM_EXEC))
7196 for_each_task_context_nr(ctxn) {
7197 ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
7201 perf_iterate_ctx(ctx, __perf_addr_filters_adjust, vma, true);
7206 void perf_event_mmap(struct vm_area_struct *vma)
7208 struct perf_mmap_event mmap_event;
7210 if (!atomic_read(&nr_mmap_events))
7213 mmap_event = (struct perf_mmap_event){
7219 .type = PERF_RECORD_MMAP,
7220 .misc = PERF_RECORD_MISC_USER,
7225 .start = vma->vm_start,
7226 .len = vma->vm_end - vma->vm_start,
7227 .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT,
7229 /* .maj (attr_mmap2 only) */
7230 /* .min (attr_mmap2 only) */
7231 /* .ino (attr_mmap2 only) */
7232 /* .ino_generation (attr_mmap2 only) */
7233 /* .prot (attr_mmap2 only) */
7234 /* .flags (attr_mmap2 only) */
7237 perf_addr_filters_adjust(vma);
7238 perf_event_mmap_event(&mmap_event);
7241 void perf_event_aux_event(struct perf_event *event, unsigned long head,
7242 unsigned long size, u64 flags)
7244 struct perf_output_handle handle;
7245 struct perf_sample_data sample;
7246 struct perf_aux_event {
7247 struct perf_event_header header;
7253 .type = PERF_RECORD_AUX,
7255 .size = sizeof(rec),
7263 perf_event_header__init_id(&rec.header, &sample, event);
7264 ret = perf_output_begin(&handle, event, rec.header.size);
7269 perf_output_put(&handle, rec);
7270 perf_event__output_id_sample(event, &handle, &sample);
7272 perf_output_end(&handle);
7276 * Lost/dropped samples logging
7278 void perf_log_lost_samples(struct perf_event *event, u64 lost)
7280 struct perf_output_handle handle;
7281 struct perf_sample_data sample;
7285 struct perf_event_header header;
7287 } lost_samples_event = {
7289 .type = PERF_RECORD_LOST_SAMPLES,
7291 .size = sizeof(lost_samples_event),
7296 perf_event_header__init_id(&lost_samples_event.header, &sample, event);
7298 ret = perf_output_begin(&handle, event,
7299 lost_samples_event.header.size);
7303 perf_output_put(&handle, lost_samples_event);
7304 perf_event__output_id_sample(event, &handle, &sample);
7305 perf_output_end(&handle);
7309 * context_switch tracking
7312 struct perf_switch_event {
7313 struct task_struct *task;
7314 struct task_struct *next_prev;
7317 struct perf_event_header header;
7323 static int perf_event_switch_match(struct perf_event *event)
7325 return event->attr.context_switch;
7328 static void perf_event_switch_output(struct perf_event *event, void *data)
7330 struct perf_switch_event *se = data;
7331 struct perf_output_handle handle;
7332 struct perf_sample_data sample;
7335 if (!perf_event_switch_match(event))
7338 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7339 if (event->ctx->task) {
7340 se->event_id.header.type = PERF_RECORD_SWITCH;
7341 se->event_id.header.size = sizeof(se->event_id.header);
7343 se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE;
7344 se->event_id.header.size = sizeof(se->event_id);
7345 se->event_id.next_prev_pid =
7346 perf_event_pid(event, se->next_prev);
7347 se->event_id.next_prev_tid =
7348 perf_event_tid(event, se->next_prev);
7351 perf_event_header__init_id(&se->event_id.header, &sample, event);
7353 ret = perf_output_begin(&handle, event, se->event_id.header.size);
7357 if (event->ctx->task)
7358 perf_output_put(&handle, se->event_id.header);
7360 perf_output_put(&handle, se->event_id);
7362 perf_event__output_id_sample(event, &handle, &sample);
7364 perf_output_end(&handle);
7367 static void perf_event_switch(struct task_struct *task,
7368 struct task_struct *next_prev, bool sched_in)
7370 struct perf_switch_event switch_event;
7372 /* N.B. caller checks nr_switch_events != 0 */
7374 switch_event = (struct perf_switch_event){
7376 .next_prev = next_prev,
7380 .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT,
7383 /* .next_prev_pid */
7384 /* .next_prev_tid */
7388 perf_iterate_sb(perf_event_switch_output,
7394 * IRQ throttle logging
7397 static void perf_log_throttle(struct perf_event *event, int enable)
7399 struct perf_output_handle handle;
7400 struct perf_sample_data sample;
7404 struct perf_event_header header;
7408 } throttle_event = {
7410 .type = PERF_RECORD_THROTTLE,
7412 .size = sizeof(throttle_event),
7414 .time = perf_event_clock(event),
7415 .id = primary_event_id(event),
7416 .stream_id = event->id,
7420 throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
7422 perf_event_header__init_id(&throttle_event.header, &sample, event);
7424 ret = perf_output_begin(&handle, event,
7425 throttle_event.header.size);
7429 perf_output_put(&handle, throttle_event);
7430 perf_event__output_id_sample(event, &handle, &sample);
7431 perf_output_end(&handle);
7434 void perf_event_itrace_started(struct perf_event *event)
7436 event->attach_state |= PERF_ATTACH_ITRACE;
7439 static void perf_log_itrace_start(struct perf_event *event)
7441 struct perf_output_handle handle;
7442 struct perf_sample_data sample;
7443 struct perf_aux_event {
7444 struct perf_event_header header;
7451 event = event->parent;
7453 if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) ||
7454 event->attach_state & PERF_ATTACH_ITRACE)
7457 rec.header.type = PERF_RECORD_ITRACE_START;
7458 rec.header.misc = 0;
7459 rec.header.size = sizeof(rec);
7460 rec.pid = perf_event_pid(event, current);
7461 rec.tid = perf_event_tid(event, current);
7463 perf_event_header__init_id(&rec.header, &sample, event);
7464 ret = perf_output_begin(&handle, event, rec.header.size);
7469 perf_output_put(&handle, rec);
7470 perf_event__output_id_sample(event, &handle, &sample);
7472 perf_output_end(&handle);
7476 __perf_event_account_interrupt(struct perf_event *event, int throttle)
7478 struct hw_perf_event *hwc = &event->hw;
7482 seq = __this_cpu_read(perf_throttled_seq);
7483 if (seq != hwc->interrupts_seq) {
7484 hwc->interrupts_seq = seq;
7485 hwc->interrupts = 1;
7488 if (unlikely(throttle
7489 && hwc->interrupts >= max_samples_per_tick)) {
7490 __this_cpu_inc(perf_throttled_count);
7491 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
7492 hwc->interrupts = MAX_INTERRUPTS;
7493 perf_log_throttle(event, 0);
7498 if (event->attr.freq) {
7499 u64 now = perf_clock();
7500 s64 delta = now - hwc->freq_time_stamp;
7502 hwc->freq_time_stamp = now;
7504 if (delta > 0 && delta < 2*TICK_NSEC)
7505 perf_adjust_period(event, delta, hwc->last_period, true);
7511 int perf_event_account_interrupt(struct perf_event *event)
7513 return __perf_event_account_interrupt(event, 1);
7517 * Generic event overflow handling, sampling.
7520 static int __perf_event_overflow(struct perf_event *event,
7521 int throttle, struct perf_sample_data *data,
7522 struct pt_regs *regs)
7524 int events = atomic_read(&event->event_limit);
7528 * Non-sampling counters might still use the PMI to fold short
7529 * hardware counters, ignore those.
7531 if (unlikely(!is_sampling_event(event)))
7534 ret = __perf_event_account_interrupt(event, throttle);
7537 * XXX event_limit might not quite work as expected on inherited
7541 event->pending_kill = POLL_IN;
7542 if (events && atomic_dec_and_test(&event->event_limit)) {
7544 event->pending_kill = POLL_HUP;
7546 perf_event_disable_inatomic(event);
7549 READ_ONCE(event->overflow_handler)(event, data, regs);
7551 if (*perf_event_fasync(event) && event->pending_kill) {
7552 event->pending_wakeup = 1;
7553 irq_work_queue(&event->pending);
7559 int perf_event_overflow(struct perf_event *event,
7560 struct perf_sample_data *data,
7561 struct pt_regs *regs)
7563 return __perf_event_overflow(event, 1, data, regs);
7567 * Generic software event infrastructure
7570 struct swevent_htable {
7571 struct swevent_hlist *swevent_hlist;
7572 struct mutex hlist_mutex;
7575 /* Recursion avoidance in each contexts */
7576 int recursion[PERF_NR_CONTEXTS];
7579 static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
7582 * We directly increment event->count and keep a second value in
7583 * event->hw.period_left to count intervals. This period event
7584 * is kept in the range [-sample_period, 0] so that we can use the
7588 u64 perf_swevent_set_period(struct perf_event *event)
7590 struct hw_perf_event *hwc = &event->hw;
7591 u64 period = hwc->last_period;
7595 hwc->last_period = hwc->sample_period;
7598 old = val = local64_read(&hwc->period_left);
7602 nr = div64_u64(period + val, period);
7603 offset = nr * period;
7605 if (local64_cmpxchg(&hwc->period_left, old, val) != old)
7611 static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
7612 struct perf_sample_data *data,
7613 struct pt_regs *regs)
7615 struct hw_perf_event *hwc = &event->hw;
7619 overflow = perf_swevent_set_period(event);
7621 if (hwc->interrupts == MAX_INTERRUPTS)
7624 for (; overflow; overflow--) {
7625 if (__perf_event_overflow(event, throttle,
7628 * We inhibit the overflow from happening when
7629 * hwc->interrupts == MAX_INTERRUPTS.
7637 static void perf_swevent_event(struct perf_event *event, u64 nr,
7638 struct perf_sample_data *data,
7639 struct pt_regs *regs)
7641 struct hw_perf_event *hwc = &event->hw;
7643 local64_add(nr, &event->count);
7648 if (!is_sampling_event(event))
7651 if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) {
7653 return perf_swevent_overflow(event, 1, data, regs);
7655 data->period = event->hw.last_period;
7657 if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
7658 return perf_swevent_overflow(event, 1, data, regs);
7660 if (local64_add_negative(nr, &hwc->period_left))
7663 perf_swevent_overflow(event, 0, data, regs);
7666 static int perf_exclude_event(struct perf_event *event,
7667 struct pt_regs *regs)
7669 if (event->hw.state & PERF_HES_STOPPED)
7673 if (event->attr.exclude_user && user_mode(regs))
7676 if (event->attr.exclude_kernel && !user_mode(regs))
7683 static int perf_swevent_match(struct perf_event *event,
7684 enum perf_type_id type,
7686 struct perf_sample_data *data,
7687 struct pt_regs *regs)
7689 if (event->attr.type != type)
7692 if (event->attr.config != event_id)
7695 if (perf_exclude_event(event, regs))
7701 static inline u64 swevent_hash(u64 type, u32 event_id)
7703 u64 val = event_id | (type << 32);
7705 return hash_64(val, SWEVENT_HLIST_BITS);
7708 static inline struct hlist_head *
7709 __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id)
7711 u64 hash = swevent_hash(type, event_id);
7713 return &hlist->heads[hash];
7716 /* For the read side: events when they trigger */
7717 static inline struct hlist_head *
7718 find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id)
7720 struct swevent_hlist *hlist;
7722 hlist = rcu_dereference(swhash->swevent_hlist);
7726 return __find_swevent_head(hlist, type, event_id);
7729 /* For the event head insertion and removal in the hlist */
7730 static inline struct hlist_head *
7731 find_swevent_head(struct swevent_htable *swhash, struct perf_event *event)
7733 struct swevent_hlist *hlist;
7734 u32 event_id = event->attr.config;
7735 u64 type = event->attr.type;
7738 * Event scheduling is always serialized against hlist allocation
7739 * and release. Which makes the protected version suitable here.
7740 * The context lock guarantees that.
7742 hlist = rcu_dereference_protected(swhash->swevent_hlist,
7743 lockdep_is_held(&event->ctx->lock));
7747 return __find_swevent_head(hlist, type, event_id);
7750 static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
7752 struct perf_sample_data *data,
7753 struct pt_regs *regs)
7755 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7756 struct perf_event *event;
7757 struct hlist_head *head;
7760 head = find_swevent_head_rcu(swhash, type, event_id);
7764 hlist_for_each_entry_rcu(event, head, hlist_entry) {
7765 if (perf_swevent_match(event, type, event_id, data, regs))
7766 perf_swevent_event(event, nr, data, regs);
7772 DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]);
7774 int perf_swevent_get_recursion_context(void)
7776 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7778 return get_recursion_context(swhash->recursion);
7780 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
7782 void perf_swevent_put_recursion_context(int rctx)
7784 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7786 put_recursion_context(swhash->recursion, rctx);
7789 void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
7791 struct perf_sample_data data;
7793 if (WARN_ON_ONCE(!regs))
7796 perf_sample_data_init(&data, addr, 0);
7797 do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);
7800 void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
7804 preempt_disable_notrace();
7805 rctx = perf_swevent_get_recursion_context();
7806 if (unlikely(rctx < 0))
7809 ___perf_sw_event(event_id, nr, regs, addr);
7811 perf_swevent_put_recursion_context(rctx);
7813 preempt_enable_notrace();
7816 static void perf_swevent_read(struct perf_event *event)
7820 static int perf_swevent_add(struct perf_event *event, int flags)
7822 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7823 struct hw_perf_event *hwc = &event->hw;
7824 struct hlist_head *head;
7826 if (is_sampling_event(event)) {
7827 hwc->last_period = hwc->sample_period;
7828 perf_swevent_set_period(event);
7831 hwc->state = !(flags & PERF_EF_START);
7833 head = find_swevent_head(swhash, event);
7834 if (WARN_ON_ONCE(!head))
7837 hlist_add_head_rcu(&event->hlist_entry, head);
7838 perf_event_update_userpage(event);
7843 static void perf_swevent_del(struct perf_event *event, int flags)
7845 hlist_del_rcu(&event->hlist_entry);
7848 static void perf_swevent_start(struct perf_event *event, int flags)
7850 event->hw.state = 0;
7853 static void perf_swevent_stop(struct perf_event *event, int flags)
7855 event->hw.state = PERF_HES_STOPPED;
7858 /* Deref the hlist from the update side */
7859 static inline struct swevent_hlist *
7860 swevent_hlist_deref(struct swevent_htable *swhash)
7862 return rcu_dereference_protected(swhash->swevent_hlist,
7863 lockdep_is_held(&swhash->hlist_mutex));
7866 static void swevent_hlist_release(struct swevent_htable *swhash)
7868 struct swevent_hlist *hlist = swevent_hlist_deref(swhash);
7873 RCU_INIT_POINTER(swhash->swevent_hlist, NULL);
7874 kfree_rcu(hlist, rcu_head);
7877 static void swevent_hlist_put_cpu(int cpu)
7879 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
7881 mutex_lock(&swhash->hlist_mutex);
7883 if (!--swhash->hlist_refcount)
7884 swevent_hlist_release(swhash);
7886 mutex_unlock(&swhash->hlist_mutex);
7889 static void swevent_hlist_put(void)
7893 for_each_possible_cpu(cpu)
7894 swevent_hlist_put_cpu(cpu);
7897 static int swevent_hlist_get_cpu(int cpu)
7899 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
7902 mutex_lock(&swhash->hlist_mutex);
7903 if (!swevent_hlist_deref(swhash) &&
7904 cpumask_test_cpu(cpu, perf_online_mask)) {
7905 struct swevent_hlist *hlist;
7907 hlist = kzalloc(sizeof(*hlist), GFP_KERNEL);
7912 rcu_assign_pointer(swhash->swevent_hlist, hlist);
7914 swhash->hlist_refcount++;
7916 mutex_unlock(&swhash->hlist_mutex);
7921 static int swevent_hlist_get(void)
7923 int err, cpu, failed_cpu;
7925 mutex_lock(&pmus_lock);
7926 for_each_possible_cpu(cpu) {
7927 err = swevent_hlist_get_cpu(cpu);
7933 mutex_unlock(&pmus_lock);
7936 for_each_possible_cpu(cpu) {
7937 if (cpu == failed_cpu)
7939 swevent_hlist_put_cpu(cpu);
7941 mutex_unlock(&pmus_lock);
7945 struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
7947 static void sw_perf_event_destroy(struct perf_event *event)
7949 u64 event_id = event->attr.config;
7951 WARN_ON(event->parent);
7953 static_key_slow_dec(&perf_swevent_enabled[event_id]);
7954 swevent_hlist_put();
7957 static int perf_swevent_init(struct perf_event *event)
7959 u64 event_id = event->attr.config;
7961 if (event->attr.type != PERF_TYPE_SOFTWARE)
7965 * no branch sampling for software events
7967 if (has_branch_stack(event))
7971 case PERF_COUNT_SW_CPU_CLOCK:
7972 case PERF_COUNT_SW_TASK_CLOCK:
7979 if (event_id >= PERF_COUNT_SW_MAX)
7982 if (!event->parent) {
7985 err = swevent_hlist_get();
7989 static_key_slow_inc(&perf_swevent_enabled[event_id]);
7990 event->destroy = sw_perf_event_destroy;
7996 static struct pmu perf_swevent = {
7997 .task_ctx_nr = perf_sw_context,
7999 .capabilities = PERF_PMU_CAP_NO_NMI,
8001 .event_init = perf_swevent_init,
8002 .add = perf_swevent_add,
8003 .del = perf_swevent_del,
8004 .start = perf_swevent_start,
8005 .stop = perf_swevent_stop,
8006 .read = perf_swevent_read,
8009 #ifdef CONFIG_EVENT_TRACING
8011 static int perf_tp_filter_match(struct perf_event *event,
8012 struct perf_sample_data *data)
8014 void *record = data->raw->frag.data;
8016 /* only top level events have filters set */
8018 event = event->parent;
8020 if (likely(!event->filter) || filter_match_preds(event->filter, record))
8025 static int perf_tp_event_match(struct perf_event *event,
8026 struct perf_sample_data *data,
8027 struct pt_regs *regs)
8029 if (event->hw.state & PERF_HES_STOPPED)
8032 * All tracepoints are from kernel-space.
8034 if (event->attr.exclude_kernel)
8037 if (!perf_tp_filter_match(event, data))
8043 void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx,
8044 struct trace_event_call *call, u64 count,
8045 struct pt_regs *regs, struct hlist_head *head,
8046 struct task_struct *task)
8048 struct bpf_prog *prog = call->prog;
8051 *(struct pt_regs **)raw_data = regs;
8052 if (!trace_call_bpf(prog, raw_data) || hlist_empty(head)) {
8053 perf_swevent_put_recursion_context(rctx);
8057 perf_tp_event(call->event.type, count, raw_data, size, regs, head,
8060 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit);
8062 void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,
8063 struct pt_regs *regs, struct hlist_head *head, int rctx,
8064 struct task_struct *task, struct perf_event *event)
8066 struct perf_sample_data data;
8068 struct perf_raw_record raw = {
8075 perf_sample_data_init(&data, 0, 0);
8078 perf_trace_buf_update(record, event_type);
8080 /* Use the given event instead of the hlist */
8082 if (perf_tp_event_match(event, &data, regs))
8083 perf_swevent_event(event, count, &data, regs);
8085 hlist_for_each_entry_rcu(event, head, hlist_entry) {
8086 if (perf_tp_event_match(event, &data, regs))
8087 perf_swevent_event(event, count, &data, regs);
8092 * If we got specified a target task, also iterate its context and
8093 * deliver this event there too.
8095 if (task && task != current) {
8096 struct perf_event_context *ctx;
8097 struct trace_entry *entry = record;
8100 ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]);
8104 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
8105 if (event->cpu != smp_processor_id())
8107 if (event->attr.type != PERF_TYPE_TRACEPOINT)
8109 if (event->attr.config != entry->type)
8111 if (perf_tp_event_match(event, &data, regs))
8112 perf_swevent_event(event, count, &data, regs);
8118 perf_swevent_put_recursion_context(rctx);
8120 EXPORT_SYMBOL_GPL(perf_tp_event);
8122 static void tp_perf_event_destroy(struct perf_event *event)
8124 perf_trace_destroy(event);
8127 static int perf_tp_event_init(struct perf_event *event)
8131 if (event->attr.type != PERF_TYPE_TRACEPOINT)
8135 * no branch sampling for tracepoint events
8137 if (has_branch_stack(event))
8140 err = perf_trace_init(event);
8144 event->destroy = tp_perf_event_destroy;
8149 static struct pmu perf_tracepoint = {
8150 .task_ctx_nr = perf_sw_context,
8152 .event_init = perf_tp_event_init,
8153 .add = perf_trace_add,
8154 .del = perf_trace_del,
8155 .start = perf_swevent_start,
8156 .stop = perf_swevent_stop,
8157 .read = perf_swevent_read,
8160 static inline void perf_tp_register(void)
8162 perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
8165 static void perf_event_free_filter(struct perf_event *event)
8167 ftrace_profile_free_filter(event);
8170 #ifdef CONFIG_BPF_SYSCALL
8171 static void bpf_overflow_handler(struct perf_event *event,
8172 struct perf_sample_data *data,
8173 struct pt_regs *regs)
8175 struct bpf_perf_event_data_kern ctx = {
8182 if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
8185 ret = BPF_PROG_RUN(event->prog, &ctx);
8188 __this_cpu_dec(bpf_prog_active);
8193 event->orig_overflow_handler(event, data, regs);
8196 static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd)
8198 struct bpf_prog *prog;
8200 if (event->overflow_handler_context)
8201 /* hw breakpoint or kernel counter */
8207 prog = bpf_prog_get_type(prog_fd, BPF_PROG_TYPE_PERF_EVENT);
8209 return PTR_ERR(prog);
8212 event->orig_overflow_handler = READ_ONCE(event->overflow_handler);
8213 WRITE_ONCE(event->overflow_handler, bpf_overflow_handler);
8217 static void perf_event_free_bpf_handler(struct perf_event *event)
8219 struct bpf_prog *prog = event->prog;
8224 WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler);
8229 static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd)
8233 static void perf_event_free_bpf_handler(struct perf_event *event)
8238 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
8240 bool is_kprobe, is_tracepoint, is_syscall_tp;
8241 struct bpf_prog *prog;
8243 if (event->attr.type != PERF_TYPE_TRACEPOINT)
8244 return perf_event_set_bpf_handler(event, prog_fd);
8246 if (event->tp_event->prog)
8249 is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE;
8250 is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT;
8251 is_syscall_tp = is_syscall_trace_event(event->tp_event);
8252 if (!is_kprobe && !is_tracepoint && !is_syscall_tp)
8253 /* bpf programs can only be attached to u/kprobe or tracepoint */
8256 prog = bpf_prog_get(prog_fd);
8258 return PTR_ERR(prog);
8260 if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) ||
8261 (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT) ||
8262 (is_syscall_tp && prog->type != BPF_PROG_TYPE_TRACEPOINT)) {
8263 /* valid fd, but invalid bpf program type */
8268 if (is_tracepoint || is_syscall_tp) {
8269 int off = trace_event_get_offsets(event->tp_event);
8271 if (prog->aux->max_ctx_offset > off) {
8276 event->tp_event->prog = prog;
8277 event->tp_event->bpf_prog_owner = event;
8282 static void perf_event_free_bpf_prog(struct perf_event *event)
8284 struct bpf_prog *prog;
8286 perf_event_free_bpf_handler(event);
8288 if (!event->tp_event)
8291 prog = event->tp_event->prog;
8292 if (prog && event->tp_event->bpf_prog_owner == event) {
8293 event->tp_event->prog = NULL;
8300 static inline void perf_tp_register(void)
8304 static void perf_event_free_filter(struct perf_event *event)
8308 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
8313 static void perf_event_free_bpf_prog(struct perf_event *event)
8316 #endif /* CONFIG_EVENT_TRACING */
8318 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8319 void perf_bp_event(struct perf_event *bp, void *data)
8321 struct perf_sample_data sample;
8322 struct pt_regs *regs = data;
8324 perf_sample_data_init(&sample, bp->attr.bp_addr, 0);
8326 if (!bp->hw.state && !perf_exclude_event(bp, regs))
8327 perf_swevent_event(bp, 1, &sample, regs);
8332 * Allocate a new address filter
8334 static struct perf_addr_filter *
8335 perf_addr_filter_new(struct perf_event *event, struct list_head *filters)
8337 int node = cpu_to_node(event->cpu == -1 ? 0 : event->cpu);
8338 struct perf_addr_filter *filter;
8340 filter = kzalloc_node(sizeof(*filter), GFP_KERNEL, node);
8344 INIT_LIST_HEAD(&filter->entry);
8345 list_add_tail(&filter->entry, filters);
8350 static void free_filters_list(struct list_head *filters)
8352 struct perf_addr_filter *filter, *iter;
8354 list_for_each_entry_safe(filter, iter, filters, entry) {
8355 path_put(&filter->path);
8356 list_del(&filter->entry);
8362 * Free existing address filters and optionally install new ones
8364 static void perf_addr_filters_splice(struct perf_event *event,
8365 struct list_head *head)
8367 unsigned long flags;
8370 if (!has_addr_filter(event))
8373 /* don't bother with children, they don't have their own filters */
8377 raw_spin_lock_irqsave(&event->addr_filters.lock, flags);
8379 list_splice_init(&event->addr_filters.list, &list);
8381 list_splice(head, &event->addr_filters.list);
8383 raw_spin_unlock_irqrestore(&event->addr_filters.lock, flags);
8385 free_filters_list(&list);
8389 * Scan through mm's vmas and see if one of them matches the
8390 * @filter; if so, adjust filter's address range.
8391 * Called with mm::mmap_sem down for reading.
8393 static unsigned long perf_addr_filter_apply(struct perf_addr_filter *filter,
8394 struct mm_struct *mm)
8396 struct vm_area_struct *vma;
8398 for (vma = mm->mmap; vma; vma = vma->vm_next) {
8399 struct file *file = vma->vm_file;
8400 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
8401 unsigned long vma_size = vma->vm_end - vma->vm_start;
8406 if (!perf_addr_filter_match(filter, file, off, vma_size))
8409 return vma->vm_start;
8416 * Update event's address range filters based on the
8417 * task's existing mappings, if any.
8419 static void perf_event_addr_filters_apply(struct perf_event *event)
8421 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
8422 struct task_struct *task = READ_ONCE(event->ctx->task);
8423 struct perf_addr_filter *filter;
8424 struct mm_struct *mm = NULL;
8425 unsigned int count = 0;
8426 unsigned long flags;
8429 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8430 * will stop on the parent's child_mutex that our caller is also holding
8432 if (task == TASK_TOMBSTONE)
8435 if (!ifh->nr_file_filters)
8438 mm = get_task_mm(task);
8442 down_read(&mm->mmap_sem);
8444 raw_spin_lock_irqsave(&ifh->lock, flags);
8445 list_for_each_entry(filter, &ifh->list, entry) {
8446 event->addr_filters_offs[count] = 0;
8449 * Adjust base offset if the filter is associated to a binary
8450 * that needs to be mapped:
8452 if (filter->path.dentry)
8453 event->addr_filters_offs[count] =
8454 perf_addr_filter_apply(filter, mm);
8459 event->addr_filters_gen++;
8460 raw_spin_unlock_irqrestore(&ifh->lock, flags);
8462 up_read(&mm->mmap_sem);
8467 perf_event_stop(event, 1);
8471 * Address range filtering: limiting the data to certain
8472 * instruction address ranges. Filters are ioctl()ed to us from
8473 * userspace as ascii strings.
8475 * Filter string format:
8478 * where ACTION is one of the
8479 * * "filter": limit the trace to this region
8480 * * "start": start tracing from this address
8481 * * "stop": stop tracing at this address/region;
8483 * * for kernel addresses: <start address>[/<size>]
8484 * * for object files: <start address>[/<size>]@</path/to/object/file>
8486 * if <size> is not specified, the range is treated as a single address.
8500 IF_STATE_ACTION = 0,
8505 static const match_table_t if_tokens = {
8506 { IF_ACT_FILTER, "filter" },
8507 { IF_ACT_START, "start" },
8508 { IF_ACT_STOP, "stop" },
8509 { IF_SRC_FILE, "%u/%u@%s" },
8510 { IF_SRC_KERNEL, "%u/%u" },
8511 { IF_SRC_FILEADDR, "%u@%s" },
8512 { IF_SRC_KERNELADDR, "%u" },
8513 { IF_ACT_NONE, NULL },
8517 * Address filter string parser
8520 perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
8521 struct list_head *filters)
8523 struct perf_addr_filter *filter = NULL;
8524 char *start, *orig, *filename = NULL;
8525 substring_t args[MAX_OPT_ARGS];
8526 int state = IF_STATE_ACTION, token;
8527 unsigned int kernel = 0;
8530 orig = fstr = kstrdup(fstr, GFP_KERNEL);
8534 while ((start = strsep(&fstr, " ,\n")) != NULL) {
8540 /* filter definition begins */
8541 if (state == IF_STATE_ACTION) {
8542 filter = perf_addr_filter_new(event, filters);
8547 token = match_token(start, if_tokens, args);
8554 if (state != IF_STATE_ACTION)
8557 state = IF_STATE_SOURCE;
8560 case IF_SRC_KERNELADDR:
8564 case IF_SRC_FILEADDR:
8566 if (state != IF_STATE_SOURCE)
8569 if (token == IF_SRC_FILE || token == IF_SRC_KERNEL)
8573 ret = kstrtoul(args[0].from, 0, &filter->offset);
8577 if (filter->range) {
8579 ret = kstrtoul(args[1].from, 0, &filter->size);
8584 if (token == IF_SRC_FILE || token == IF_SRC_FILEADDR) {
8585 int fpos = filter->range ? 2 : 1;
8588 filename = match_strdup(&args[fpos]);
8595 state = IF_STATE_END;
8603 * Filter definition is fully parsed, validate and install it.
8604 * Make sure that it doesn't contradict itself or the event's
8607 if (state == IF_STATE_END) {
8609 if (kernel && event->attr.exclude_kernel)
8617 * For now, we only support file-based filters
8618 * in per-task events; doing so for CPU-wide
8619 * events requires additional context switching
8620 * trickery, since same object code will be
8621 * mapped at different virtual addresses in
8622 * different processes.
8625 if (!event->ctx->task)
8628 /* look up the path and grab its inode */
8629 ret = kern_path(filename, LOOKUP_FOLLOW,
8635 if (!filter->path.dentry ||
8636 !S_ISREG(d_inode(filter->path.dentry)
8640 event->addr_filters.nr_file_filters++;
8643 /* ready to consume more filters */
8644 state = IF_STATE_ACTION;
8649 if (state != IF_STATE_ACTION)
8659 free_filters_list(filters);
8666 perf_event_set_addr_filter(struct perf_event *event, char *filter_str)
8672 * Since this is called in perf_ioctl() path, we're already holding
8675 lockdep_assert_held(&event->ctx->mutex);
8677 if (WARN_ON_ONCE(event->parent))
8680 ret = perf_event_parse_addr_filter(event, filter_str, &filters);
8682 goto fail_clear_files;
8684 ret = event->pmu->addr_filters_validate(&filters);
8686 goto fail_free_filters;
8688 /* remove existing filters, if any */
8689 perf_addr_filters_splice(event, &filters);
8691 /* install new filters */
8692 perf_event_for_each_child(event, perf_event_addr_filters_apply);
8697 free_filters_list(&filters);
8700 event->addr_filters.nr_file_filters = 0;
8705 static int perf_event_set_filter(struct perf_event *event, void __user *arg)
8710 if ((event->attr.type != PERF_TYPE_TRACEPOINT ||
8711 !IS_ENABLED(CONFIG_EVENT_TRACING)) &&
8712 !has_addr_filter(event))
8715 filter_str = strndup_user(arg, PAGE_SIZE);
8716 if (IS_ERR(filter_str))
8717 return PTR_ERR(filter_str);
8719 if (IS_ENABLED(CONFIG_EVENT_TRACING) &&
8720 event->attr.type == PERF_TYPE_TRACEPOINT)
8721 ret = ftrace_profile_set_filter(event, event->attr.config,
8723 else if (has_addr_filter(event))
8724 ret = perf_event_set_addr_filter(event, filter_str);
8731 * hrtimer based swevent callback
8734 static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
8736 enum hrtimer_restart ret = HRTIMER_RESTART;
8737 struct perf_sample_data data;
8738 struct pt_regs *regs;
8739 struct perf_event *event;
8742 event = container_of(hrtimer, struct perf_event, hw.hrtimer);
8744 if (event->state != PERF_EVENT_STATE_ACTIVE)
8745 return HRTIMER_NORESTART;
8747 event->pmu->read(event);
8749 perf_sample_data_init(&data, 0, event->hw.last_period);
8750 regs = get_irq_regs();
8752 if (regs && !perf_exclude_event(event, regs)) {
8753 if (!(event->attr.exclude_idle && is_idle_task(current)))
8754 if (__perf_event_overflow(event, 1, &data, regs))
8755 ret = HRTIMER_NORESTART;
8758 period = max_t(u64, 10000, event->hw.sample_period);
8759 hrtimer_forward_now(hrtimer, ns_to_ktime(period));
8764 static void perf_swevent_start_hrtimer(struct perf_event *event)
8766 struct hw_perf_event *hwc = &event->hw;
8769 if (!is_sampling_event(event))
8772 period = local64_read(&hwc->period_left);
8777 local64_set(&hwc->period_left, 0);
8779 period = max_t(u64, 10000, hwc->sample_period);
8781 hrtimer_start(&hwc->hrtimer, ns_to_ktime(period),
8782 HRTIMER_MODE_REL_PINNED);
8785 static void perf_swevent_cancel_hrtimer(struct perf_event *event)
8787 struct hw_perf_event *hwc = &event->hw;
8789 if (is_sampling_event(event)) {
8790 ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
8791 local64_set(&hwc->period_left, ktime_to_ns(remaining));
8793 hrtimer_cancel(&hwc->hrtimer);
8797 static void perf_swevent_init_hrtimer(struct perf_event *event)
8799 struct hw_perf_event *hwc = &event->hw;
8801 if (!is_sampling_event(event))
8804 hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
8805 hwc->hrtimer.function = perf_swevent_hrtimer;
8808 * Since hrtimers have a fixed rate, we can do a static freq->period
8809 * mapping and avoid the whole period adjust feedback stuff.
8811 if (event->attr.freq) {
8812 long freq = event->attr.sample_freq;
8814 event->attr.sample_period = NSEC_PER_SEC / freq;
8815 hwc->sample_period = event->attr.sample_period;
8816 local64_set(&hwc->period_left, hwc->sample_period);
8817 hwc->last_period = hwc->sample_period;
8818 event->attr.freq = 0;
8823 * Software event: cpu wall time clock
8826 static void cpu_clock_event_update(struct perf_event *event)
8831 now = local_clock();
8832 prev = local64_xchg(&event->hw.prev_count, now);
8833 local64_add(now - prev, &event->count);
8836 static void cpu_clock_event_start(struct perf_event *event, int flags)
8838 local64_set(&event->hw.prev_count, local_clock());
8839 perf_swevent_start_hrtimer(event);
8842 static void cpu_clock_event_stop(struct perf_event *event, int flags)
8844 perf_swevent_cancel_hrtimer(event);
8845 cpu_clock_event_update(event);
8848 static int cpu_clock_event_add(struct perf_event *event, int flags)
8850 if (flags & PERF_EF_START)
8851 cpu_clock_event_start(event, flags);
8852 perf_event_update_userpage(event);
8857 static void cpu_clock_event_del(struct perf_event *event, int flags)
8859 cpu_clock_event_stop(event, flags);
8862 static void cpu_clock_event_read(struct perf_event *event)
8864 cpu_clock_event_update(event);
8867 static int cpu_clock_event_init(struct perf_event *event)
8869 if (event->attr.type != PERF_TYPE_SOFTWARE)
8872 if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
8876 * no branch sampling for software events
8878 if (has_branch_stack(event))
8881 perf_swevent_init_hrtimer(event);
8886 static struct pmu perf_cpu_clock = {
8887 .task_ctx_nr = perf_sw_context,
8889 .capabilities = PERF_PMU_CAP_NO_NMI,
8891 .event_init = cpu_clock_event_init,
8892 .add = cpu_clock_event_add,
8893 .del = cpu_clock_event_del,
8894 .start = cpu_clock_event_start,
8895 .stop = cpu_clock_event_stop,
8896 .read = cpu_clock_event_read,
8900 * Software event: task time clock
8903 static void task_clock_event_update(struct perf_event *event, u64 now)
8908 prev = local64_xchg(&event->hw.prev_count, now);
8910 local64_add(delta, &event->count);
8913 static void task_clock_event_start(struct perf_event *event, int flags)
8915 local64_set(&event->hw.prev_count, event->ctx->time);
8916 perf_swevent_start_hrtimer(event);
8919 static void task_clock_event_stop(struct perf_event *event, int flags)
8921 perf_swevent_cancel_hrtimer(event);
8922 task_clock_event_update(event, event->ctx->time);
8925 static int task_clock_event_add(struct perf_event *event, int flags)
8927 if (flags & PERF_EF_START)
8928 task_clock_event_start(event, flags);
8929 perf_event_update_userpage(event);
8934 static void task_clock_event_del(struct perf_event *event, int flags)
8936 task_clock_event_stop(event, PERF_EF_UPDATE);
8939 static void task_clock_event_read(struct perf_event *event)
8941 u64 now = perf_clock();
8942 u64 delta = now - event->ctx->timestamp;
8943 u64 time = event->ctx->time + delta;
8945 task_clock_event_update(event, time);
8948 static int task_clock_event_init(struct perf_event *event)
8950 if (event->attr.type != PERF_TYPE_SOFTWARE)
8953 if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
8957 * no branch sampling for software events
8959 if (has_branch_stack(event))
8962 perf_swevent_init_hrtimer(event);
8967 static struct pmu perf_task_clock = {
8968 .task_ctx_nr = perf_sw_context,
8970 .capabilities = PERF_PMU_CAP_NO_NMI,
8972 .event_init = task_clock_event_init,
8973 .add = task_clock_event_add,
8974 .del = task_clock_event_del,
8975 .start = task_clock_event_start,
8976 .stop = task_clock_event_stop,
8977 .read = task_clock_event_read,
8980 static void perf_pmu_nop_void(struct pmu *pmu)
8984 static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags)
8988 static int perf_pmu_nop_int(struct pmu *pmu)
8993 static int perf_event_nop_int(struct perf_event *event, u64 value)
8998 static DEFINE_PER_CPU(unsigned int, nop_txn_flags);
9000 static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags)
9002 __this_cpu_write(nop_txn_flags, flags);
9004 if (flags & ~PERF_PMU_TXN_ADD)
9007 perf_pmu_disable(pmu);
9010 static int perf_pmu_commit_txn(struct pmu *pmu)
9012 unsigned int flags = __this_cpu_read(nop_txn_flags);
9014 __this_cpu_write(nop_txn_flags, 0);
9016 if (flags & ~PERF_PMU_TXN_ADD)
9019 perf_pmu_enable(pmu);
9023 static void perf_pmu_cancel_txn(struct pmu *pmu)
9025 unsigned int flags = __this_cpu_read(nop_txn_flags);
9027 __this_cpu_write(nop_txn_flags, 0);
9029 if (flags & ~PERF_PMU_TXN_ADD)
9032 perf_pmu_enable(pmu);
9035 static int perf_event_idx_default(struct perf_event *event)
9041 * Ensures all contexts with the same task_ctx_nr have the same
9042 * pmu_cpu_context too.
9044 static struct perf_cpu_context __percpu *find_pmu_context(int ctxn)
9051 list_for_each_entry(pmu, &pmus, entry) {
9052 if (pmu->task_ctx_nr == ctxn)
9053 return pmu->pmu_cpu_context;
9059 static void free_pmu_context(struct pmu *pmu)
9062 * Static contexts such as perf_sw_context have a global lifetime
9063 * and may be shared between different PMUs. Avoid freeing them
9064 * when a single PMU is going away.
9066 if (pmu->task_ctx_nr > perf_invalid_context)
9069 free_percpu(pmu->pmu_cpu_context);
9073 * Let userspace know that this PMU supports address range filtering:
9075 static ssize_t nr_addr_filters_show(struct device *dev,
9076 struct device_attribute *attr,
9079 struct pmu *pmu = dev_get_drvdata(dev);
9081 return snprintf(page, PAGE_SIZE - 1, "%d\n", pmu->nr_addr_filters);
9083 DEVICE_ATTR_RO(nr_addr_filters);
9085 static struct idr pmu_idr;
9088 type_show(struct device *dev, struct device_attribute *attr, char *page)
9090 struct pmu *pmu = dev_get_drvdata(dev);
9092 return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type);
9094 static DEVICE_ATTR_RO(type);
9097 perf_event_mux_interval_ms_show(struct device *dev,
9098 struct device_attribute *attr,
9101 struct pmu *pmu = dev_get_drvdata(dev);
9103 return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms);
9106 static DEFINE_MUTEX(mux_interval_mutex);
9109 perf_event_mux_interval_ms_store(struct device *dev,
9110 struct device_attribute *attr,
9111 const char *buf, size_t count)
9113 struct pmu *pmu = dev_get_drvdata(dev);
9114 int timer, cpu, ret;
9116 ret = kstrtoint(buf, 0, &timer);
9123 /* same value, noting to do */
9124 if (timer == pmu->hrtimer_interval_ms)
9127 mutex_lock(&mux_interval_mutex);
9128 pmu->hrtimer_interval_ms = timer;
9130 /* update all cpuctx for this PMU */
9132 for_each_online_cpu(cpu) {
9133 struct perf_cpu_context *cpuctx;
9134 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
9135 cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
9137 cpu_function_call(cpu,
9138 (remote_function_f)perf_mux_hrtimer_restart, cpuctx);
9141 mutex_unlock(&mux_interval_mutex);
9145 static DEVICE_ATTR_RW(perf_event_mux_interval_ms);
9147 static struct attribute *pmu_dev_attrs[] = {
9148 &dev_attr_type.attr,
9149 &dev_attr_perf_event_mux_interval_ms.attr,
9152 ATTRIBUTE_GROUPS(pmu_dev);
9154 static int pmu_bus_running;
9155 static struct bus_type pmu_bus = {
9156 .name = "event_source",
9157 .dev_groups = pmu_dev_groups,
9160 static void pmu_dev_release(struct device *dev)
9165 static int pmu_dev_alloc(struct pmu *pmu)
9169 pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
9173 pmu->dev->groups = pmu->attr_groups;
9174 device_initialize(pmu->dev);
9175 ret = dev_set_name(pmu->dev, "%s", pmu->name);
9179 dev_set_drvdata(pmu->dev, pmu);
9180 pmu->dev->bus = &pmu_bus;
9181 pmu->dev->release = pmu_dev_release;
9182 ret = device_add(pmu->dev);
9186 /* For PMUs with address filters, throw in an extra attribute: */
9187 if (pmu->nr_addr_filters)
9188 ret = device_create_file(pmu->dev, &dev_attr_nr_addr_filters);
9197 device_del(pmu->dev);
9200 put_device(pmu->dev);
9204 static struct lock_class_key cpuctx_mutex;
9205 static struct lock_class_key cpuctx_lock;
9207 int perf_pmu_register(struct pmu *pmu, const char *name, int type)
9211 mutex_lock(&pmus_lock);
9213 pmu->pmu_disable_count = alloc_percpu(int);
9214 if (!pmu->pmu_disable_count)
9223 type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL);
9231 if (pmu_bus_running) {
9232 ret = pmu_dev_alloc(pmu);
9238 if (pmu->task_ctx_nr == perf_hw_context) {
9239 static int hw_context_taken = 0;
9242 * Other than systems with heterogeneous CPUs, it never makes
9243 * sense for two PMUs to share perf_hw_context. PMUs which are
9244 * uncore must use perf_invalid_context.
9246 if (WARN_ON_ONCE(hw_context_taken &&
9247 !(pmu->capabilities & PERF_PMU_CAP_HETEROGENEOUS_CPUS)))
9248 pmu->task_ctx_nr = perf_invalid_context;
9250 hw_context_taken = 1;
9253 pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr);
9254 if (pmu->pmu_cpu_context)
9255 goto got_cpu_context;
9258 pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context);
9259 if (!pmu->pmu_cpu_context)
9262 for_each_possible_cpu(cpu) {
9263 struct perf_cpu_context *cpuctx;
9265 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
9266 __perf_event_init_context(&cpuctx->ctx);
9267 lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
9268 lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
9269 cpuctx->ctx.pmu = pmu;
9270 cpuctx->online = cpumask_test_cpu(cpu, perf_online_mask);
9272 __perf_mux_hrtimer_init(cpuctx, cpu);
9276 if (!pmu->start_txn) {
9277 if (pmu->pmu_enable) {
9279 * If we have pmu_enable/pmu_disable calls, install
9280 * transaction stubs that use that to try and batch
9281 * hardware accesses.
9283 pmu->start_txn = perf_pmu_start_txn;
9284 pmu->commit_txn = perf_pmu_commit_txn;
9285 pmu->cancel_txn = perf_pmu_cancel_txn;
9287 pmu->start_txn = perf_pmu_nop_txn;
9288 pmu->commit_txn = perf_pmu_nop_int;
9289 pmu->cancel_txn = perf_pmu_nop_void;
9293 if (!pmu->pmu_enable) {
9294 pmu->pmu_enable = perf_pmu_nop_void;
9295 pmu->pmu_disable = perf_pmu_nop_void;
9298 if (!pmu->check_period)
9299 pmu->check_period = perf_event_nop_int;
9301 if (!pmu->event_idx)
9302 pmu->event_idx = perf_event_idx_default;
9304 list_add_rcu(&pmu->entry, &pmus);
9305 atomic_set(&pmu->exclusive_cnt, 0);
9308 mutex_unlock(&pmus_lock);
9313 device_del(pmu->dev);
9314 put_device(pmu->dev);
9317 if (pmu->type >= PERF_TYPE_MAX)
9318 idr_remove(&pmu_idr, pmu->type);
9321 free_percpu(pmu->pmu_disable_count);
9324 EXPORT_SYMBOL_GPL(perf_pmu_register);
9326 void perf_pmu_unregister(struct pmu *pmu)
9328 mutex_lock(&pmus_lock);
9329 list_del_rcu(&pmu->entry);
9332 * We dereference the pmu list under both SRCU and regular RCU, so
9333 * synchronize against both of those.
9335 synchronize_srcu(&pmus_srcu);
9338 free_percpu(pmu->pmu_disable_count);
9339 if (pmu->type >= PERF_TYPE_MAX)
9340 idr_remove(&pmu_idr, pmu->type);
9341 if (pmu_bus_running) {
9342 if (pmu->nr_addr_filters)
9343 device_remove_file(pmu->dev, &dev_attr_nr_addr_filters);
9344 device_del(pmu->dev);
9345 put_device(pmu->dev);
9347 free_pmu_context(pmu);
9348 mutex_unlock(&pmus_lock);
9350 EXPORT_SYMBOL_GPL(perf_pmu_unregister);
9352 static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
9354 struct perf_event_context *ctx = NULL;
9357 if (!try_module_get(pmu->module))
9360 if (event->group_leader != event) {
9362 * This ctx->mutex can nest when we're called through
9363 * inheritance. See the perf_event_ctx_lock_nested() comment.
9365 ctx = perf_event_ctx_lock_nested(event->group_leader,
9366 SINGLE_DEPTH_NESTING);
9371 ret = pmu->event_init(event);
9374 perf_event_ctx_unlock(event->group_leader, ctx);
9377 module_put(pmu->module);
9382 static struct pmu *perf_init_event(struct perf_event *event)
9388 idx = srcu_read_lock(&pmus_srcu);
9390 /* Try parent's PMU first: */
9391 if (event->parent && event->parent->pmu) {
9392 pmu = event->parent->pmu;
9393 ret = perf_try_init_event(pmu, event);
9399 pmu = idr_find(&pmu_idr, event->attr.type);
9402 ret = perf_try_init_event(pmu, event);
9408 list_for_each_entry_rcu(pmu, &pmus, entry) {
9409 ret = perf_try_init_event(pmu, event);
9413 if (ret != -ENOENT) {
9418 pmu = ERR_PTR(-ENOENT);
9420 srcu_read_unlock(&pmus_srcu, idx);
9425 static void attach_sb_event(struct perf_event *event)
9427 struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
9429 raw_spin_lock(&pel->lock);
9430 list_add_rcu(&event->sb_list, &pel->list);
9431 raw_spin_unlock(&pel->lock);
9435 * We keep a list of all !task (and therefore per-cpu) events
9436 * that need to receive side-band records.
9438 * This avoids having to scan all the various PMU per-cpu contexts
9441 static void account_pmu_sb_event(struct perf_event *event)
9443 if (is_sb_event(event))
9444 attach_sb_event(event);
9447 static void account_event_cpu(struct perf_event *event, int cpu)
9452 if (is_cgroup_event(event))
9453 atomic_inc(&per_cpu(perf_cgroup_events, cpu));
9456 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9457 static void account_freq_event_nohz(void)
9459 #ifdef CONFIG_NO_HZ_FULL
9460 /* Lock so we don't race with concurrent unaccount */
9461 spin_lock(&nr_freq_lock);
9462 if (atomic_inc_return(&nr_freq_events) == 1)
9463 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS);
9464 spin_unlock(&nr_freq_lock);
9468 static void account_freq_event(void)
9470 if (tick_nohz_full_enabled())
9471 account_freq_event_nohz();
9473 atomic_inc(&nr_freq_events);
9477 static void account_event(struct perf_event *event)
9484 if (event->attach_state & PERF_ATTACH_TASK)
9486 if (event->attr.mmap || event->attr.mmap_data)
9487 atomic_inc(&nr_mmap_events);
9488 if (event->attr.comm)
9489 atomic_inc(&nr_comm_events);
9490 if (event->attr.namespaces)
9491 atomic_inc(&nr_namespaces_events);
9492 if (event->attr.task)
9493 atomic_inc(&nr_task_events);
9494 if (event->attr.freq)
9495 account_freq_event();
9496 if (event->attr.context_switch) {
9497 atomic_inc(&nr_switch_events);
9500 if (has_branch_stack(event))
9502 if (is_cgroup_event(event))
9506 if (atomic_inc_not_zero(&perf_sched_count))
9509 mutex_lock(&perf_sched_mutex);
9510 if (!atomic_read(&perf_sched_count)) {
9511 static_branch_enable(&perf_sched_events);
9513 * Guarantee that all CPUs observe they key change and
9514 * call the perf scheduling hooks before proceeding to
9515 * install events that need them.
9517 synchronize_sched();
9520 * Now that we have waited for the sync_sched(), allow further
9521 * increments to by-pass the mutex.
9523 atomic_inc(&perf_sched_count);
9524 mutex_unlock(&perf_sched_mutex);
9528 account_event_cpu(event, event->cpu);
9530 account_pmu_sb_event(event);
9534 * Allocate and initialize a event structure
9536 static struct perf_event *
9537 perf_event_alloc(struct perf_event_attr *attr, int cpu,
9538 struct task_struct *task,
9539 struct perf_event *group_leader,
9540 struct perf_event *parent_event,
9541 perf_overflow_handler_t overflow_handler,
9542 void *context, int cgroup_fd)
9545 struct perf_event *event;
9546 struct hw_perf_event *hwc;
9549 if ((unsigned)cpu >= nr_cpu_ids) {
9550 if (!task || cpu != -1)
9551 return ERR_PTR(-EINVAL);
9554 event = kzalloc(sizeof(*event), GFP_KERNEL);
9556 return ERR_PTR(-ENOMEM);
9559 * Single events are their own group leaders, with an
9560 * empty sibling list:
9563 group_leader = event;
9565 mutex_init(&event->child_mutex);
9566 INIT_LIST_HEAD(&event->child_list);
9568 INIT_LIST_HEAD(&event->group_entry);
9569 INIT_LIST_HEAD(&event->event_entry);
9570 INIT_LIST_HEAD(&event->sibling_list);
9571 INIT_LIST_HEAD(&event->rb_entry);
9572 INIT_LIST_HEAD(&event->active_entry);
9573 INIT_LIST_HEAD(&event->addr_filters.list);
9574 INIT_HLIST_NODE(&event->hlist_entry);
9577 init_waitqueue_head(&event->waitq);
9578 init_irq_work(&event->pending, perf_pending_event);
9580 mutex_init(&event->mmap_mutex);
9581 raw_spin_lock_init(&event->addr_filters.lock);
9583 atomic_long_set(&event->refcount, 1);
9585 event->attr = *attr;
9586 event->group_leader = group_leader;
9590 event->parent = parent_event;
9592 event->ns = get_pid_ns(task_active_pid_ns(current));
9593 event->id = atomic64_inc_return(&perf_event_id);
9595 event->state = PERF_EVENT_STATE_INACTIVE;
9598 event->attach_state = PERF_ATTACH_TASK;
9600 * XXX pmu::event_init needs to know what task to account to
9601 * and we cannot use the ctx information because we need the
9602 * pmu before we get a ctx.
9604 get_task_struct(task);
9605 event->hw.target = task;
9608 event->clock = &local_clock;
9610 event->clock = parent_event->clock;
9612 if (!overflow_handler && parent_event) {
9613 overflow_handler = parent_event->overflow_handler;
9614 context = parent_event->overflow_handler_context;
9615 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9616 if (overflow_handler == bpf_overflow_handler) {
9617 struct bpf_prog *prog = bpf_prog_inc(parent_event->prog);
9620 err = PTR_ERR(prog);
9624 event->orig_overflow_handler =
9625 parent_event->orig_overflow_handler;
9630 if (overflow_handler) {
9631 event->overflow_handler = overflow_handler;
9632 event->overflow_handler_context = context;
9633 } else if (is_write_backward(event)){
9634 event->overflow_handler = perf_event_output_backward;
9635 event->overflow_handler_context = NULL;
9637 event->overflow_handler = perf_event_output_forward;
9638 event->overflow_handler_context = NULL;
9641 perf_event__state_init(event);
9646 hwc->sample_period = attr->sample_period;
9647 if (attr->freq && attr->sample_freq)
9648 hwc->sample_period = 1;
9649 hwc->last_period = hwc->sample_period;
9651 local64_set(&hwc->period_left, hwc->sample_period);
9654 * We currently do not support PERF_SAMPLE_READ on inherited events.
9655 * See perf_output_read().
9657 if (attr->inherit && (attr->sample_type & PERF_SAMPLE_READ))
9660 if (!has_branch_stack(event))
9661 event->attr.branch_sample_type = 0;
9663 if (cgroup_fd != -1) {
9664 err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
9669 pmu = perf_init_event(event);
9675 err = exclusive_event_init(event);
9679 if (has_addr_filter(event)) {
9680 event->addr_filters_offs = kcalloc(pmu->nr_addr_filters,
9681 sizeof(unsigned long),
9683 if (!event->addr_filters_offs) {
9688 /* force hw sync on the address filters */
9689 event->addr_filters_gen = 1;
9692 if (!event->parent) {
9693 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
9694 err = get_callchain_buffers(attr->sample_max_stack);
9696 goto err_addr_filters;
9700 /* symmetric to unaccount_event() in _free_event() */
9701 account_event(event);
9706 kfree(event->addr_filters_offs);
9709 exclusive_event_destroy(event);
9713 event->destroy(event);
9714 module_put(pmu->module);
9716 if (is_cgroup_event(event))
9717 perf_detach_cgroup(event);
9719 put_pid_ns(event->ns);
9720 if (event->hw.target)
9721 put_task_struct(event->hw.target);
9724 return ERR_PTR(err);
9727 static int perf_copy_attr(struct perf_event_attr __user *uattr,
9728 struct perf_event_attr *attr)
9733 if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
9737 * zero the full structure, so that a short copy will be nice.
9739 memset(attr, 0, sizeof(*attr));
9741 ret = get_user(size, &uattr->size);
9745 if (size > PAGE_SIZE) /* silly large */
9748 if (!size) /* abi compat */
9749 size = PERF_ATTR_SIZE_VER0;
9751 if (size < PERF_ATTR_SIZE_VER0)
9755 * If we're handed a bigger struct than we know of,
9756 * ensure all the unknown bits are 0 - i.e. new
9757 * user-space does not rely on any kernel feature
9758 * extensions we dont know about yet.
9760 if (size > sizeof(*attr)) {
9761 unsigned char __user *addr;
9762 unsigned char __user *end;
9765 addr = (void __user *)uattr + sizeof(*attr);
9766 end = (void __user *)uattr + size;
9768 for (; addr < end; addr++) {
9769 ret = get_user(val, addr);
9775 size = sizeof(*attr);
9778 ret = copy_from_user(attr, uattr, size);
9784 if (attr->__reserved_1)
9787 if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
9790 if (attr->read_format & ~(PERF_FORMAT_MAX-1))
9793 if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
9794 u64 mask = attr->branch_sample_type;
9796 /* only using defined bits */
9797 if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1))
9800 /* at least one branch bit must be set */
9801 if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL))
9804 /* propagate priv level, when not set for branch */
9805 if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) {
9807 /* exclude_kernel checked on syscall entry */
9808 if (!attr->exclude_kernel)
9809 mask |= PERF_SAMPLE_BRANCH_KERNEL;
9811 if (!attr->exclude_user)
9812 mask |= PERF_SAMPLE_BRANCH_USER;
9814 if (!attr->exclude_hv)
9815 mask |= PERF_SAMPLE_BRANCH_HV;
9817 * adjust user setting (for HW filter setup)
9819 attr->branch_sample_type = mask;
9821 /* privileged levels capture (kernel, hv): check permissions */
9822 if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM)
9823 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
9827 if (attr->sample_type & PERF_SAMPLE_REGS_USER) {
9828 ret = perf_reg_validate(attr->sample_regs_user);
9833 if (attr->sample_type & PERF_SAMPLE_STACK_USER) {
9834 if (!arch_perf_have_user_stack_dump())
9838 * We have __u32 type for the size, but so far
9839 * we can only use __u16 as maximum due to the
9840 * __u16 sample size limit.
9842 if (attr->sample_stack_user >= USHRT_MAX)
9844 else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
9848 if (attr->sample_type & PERF_SAMPLE_REGS_INTR)
9849 ret = perf_reg_validate(attr->sample_regs_intr);
9854 put_user(sizeof(*attr), &uattr->size);
9860 perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
9862 struct ring_buffer *rb = NULL;
9868 /* don't allow circular references */
9869 if (event == output_event)
9873 * Don't allow cross-cpu buffers
9875 if (output_event->cpu != event->cpu)
9879 * If its not a per-cpu rb, it must be the same task.
9881 if (output_event->cpu == -1 && output_event->ctx != event->ctx)
9885 * Mixing clocks in the same buffer is trouble you don't need.
9887 if (output_event->clock != event->clock)
9891 * Either writing ring buffer from beginning or from end.
9892 * Mixing is not allowed.
9894 if (is_write_backward(output_event) != is_write_backward(event))
9898 * If both events generate aux data, they must be on the same PMU
9900 if (has_aux(event) && has_aux(output_event) &&
9901 event->pmu != output_event->pmu)
9905 mutex_lock(&event->mmap_mutex);
9906 /* Can't redirect output if we've got an active mmap() */
9907 if (atomic_read(&event->mmap_count))
9911 /* get the rb we want to redirect to */
9912 rb = ring_buffer_get(output_event);
9917 ring_buffer_attach(event, rb);
9921 mutex_unlock(&event->mmap_mutex);
9927 static void mutex_lock_double(struct mutex *a, struct mutex *b)
9933 mutex_lock_nested(b, SINGLE_DEPTH_NESTING);
9936 static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
9938 bool nmi_safe = false;
9941 case CLOCK_MONOTONIC:
9942 event->clock = &ktime_get_mono_fast_ns;
9946 case CLOCK_MONOTONIC_RAW:
9947 event->clock = &ktime_get_raw_fast_ns;
9951 case CLOCK_REALTIME:
9952 event->clock = &ktime_get_real_ns;
9955 case CLOCK_BOOTTIME:
9956 event->clock = &ktime_get_boot_ns;
9960 event->clock = &ktime_get_tai_ns;
9967 if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI))
9974 * Variation on perf_event_ctx_lock_nested(), except we take two context
9977 static struct perf_event_context *
9978 __perf_event_ctx_lock_double(struct perf_event *group_leader,
9979 struct perf_event_context *ctx)
9981 struct perf_event_context *gctx;
9985 gctx = READ_ONCE(group_leader->ctx);
9986 if (!atomic_inc_not_zero(&gctx->refcount)) {
9992 mutex_lock_double(&gctx->mutex, &ctx->mutex);
9994 if (group_leader->ctx != gctx) {
9995 mutex_unlock(&ctx->mutex);
9996 mutex_unlock(&gctx->mutex);
10005 * sys_perf_event_open - open a performance event, associate it to a task/cpu
10007 * @attr_uptr: event_id type attributes for monitoring/sampling
10010 * @group_fd: group leader event fd
10012 SYSCALL_DEFINE5(perf_event_open,
10013 struct perf_event_attr __user *, attr_uptr,
10014 pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
10016 struct perf_event *group_leader = NULL, *output_event = NULL;
10017 struct perf_event *event, *sibling;
10018 struct perf_event_attr attr;
10019 struct perf_event_context *ctx, *uninitialized_var(gctx);
10020 struct file *event_file = NULL;
10021 struct fd group = {NULL, 0};
10022 struct task_struct *task = NULL;
10025 int move_group = 0;
10027 int f_flags = O_RDWR;
10028 int cgroup_fd = -1;
10030 /* for future expandability... */
10031 if (flags & ~PERF_FLAG_ALL)
10034 err = perf_copy_attr(attr_uptr, &attr);
10038 if (!attr.exclude_kernel) {
10039 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
10043 if (attr.namespaces) {
10044 if (!capable(CAP_SYS_ADMIN))
10049 if (attr.sample_freq > sysctl_perf_event_sample_rate)
10052 if (attr.sample_period & (1ULL << 63))
10056 /* Only privileged users can get physical addresses */
10057 if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) &&
10058 perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
10061 if (!attr.sample_max_stack)
10062 attr.sample_max_stack = sysctl_perf_event_max_stack;
10065 * In cgroup mode, the pid argument is used to pass the fd
10066 * opened to the cgroup directory in cgroupfs. The cpu argument
10067 * designates the cpu on which to monitor threads from that
10070 if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
10073 if (flags & PERF_FLAG_FD_CLOEXEC)
10074 f_flags |= O_CLOEXEC;
10076 event_fd = get_unused_fd_flags(f_flags);
10080 if (group_fd != -1) {
10081 err = perf_fget_light(group_fd, &group);
10084 group_leader = group.file->private_data;
10085 if (flags & PERF_FLAG_FD_OUTPUT)
10086 output_event = group_leader;
10087 if (flags & PERF_FLAG_FD_NO_GROUP)
10088 group_leader = NULL;
10091 if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) {
10092 task = find_lively_task_by_vpid(pid);
10093 if (IS_ERR(task)) {
10094 err = PTR_ERR(task);
10099 if (task && group_leader &&
10100 group_leader->attr.inherit != attr.inherit) {
10106 err = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
10111 * Reuse ptrace permission checks for now.
10113 * We must hold cred_guard_mutex across this and any potential
10114 * perf_install_in_context() call for this new event to
10115 * serialize against exec() altering our credentials (and the
10116 * perf_event_exit_task() that could imply).
10119 if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
10123 if (flags & PERF_FLAG_PID_CGROUP)
10126 event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
10127 NULL, NULL, cgroup_fd);
10128 if (IS_ERR(event)) {
10129 err = PTR_ERR(event);
10133 if (is_sampling_event(event)) {
10134 if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
10141 * Special case software events and allow them to be part of
10142 * any hardware group.
10146 if (attr.use_clockid) {
10147 err = perf_event_set_clock(event, attr.clockid);
10152 if (pmu->task_ctx_nr == perf_sw_context)
10153 event->event_caps |= PERF_EV_CAP_SOFTWARE;
10155 if (group_leader &&
10156 (is_software_event(event) != is_software_event(group_leader))) {
10157 if (is_software_event(event)) {
10159 * If event and group_leader are not both a software
10160 * event, and event is, then group leader is not.
10162 * Allow the addition of software events to !software
10163 * groups, this is safe because software events never
10164 * fail to schedule.
10166 pmu = group_leader->pmu;
10167 } else if (is_software_event(group_leader) &&
10168 (group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) {
10170 * In case the group is a pure software group, and we
10171 * try to add a hardware event, move the whole group to
10172 * the hardware context.
10179 * Get the target context (task or percpu):
10181 ctx = find_get_context(pmu, task, event);
10183 err = PTR_ERR(ctx);
10187 if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) {
10193 * Look up the group leader (we will attach this event to it):
10195 if (group_leader) {
10199 * Do not allow a recursive hierarchy (this new sibling
10200 * becoming part of another group-sibling):
10202 if (group_leader->group_leader != group_leader)
10205 /* All events in a group should have the same clock */
10206 if (group_leader->clock != event->clock)
10210 * Make sure we're both events for the same CPU;
10211 * grouping events for different CPUs is broken; since
10212 * you can never concurrently schedule them anyhow.
10214 if (group_leader->cpu != event->cpu)
10218 * Make sure we're both on the same task, or both
10221 if (group_leader->ctx->task != ctx->task)
10225 * Do not allow to attach to a group in a different task
10226 * or CPU context. If we're moving SW events, we'll fix
10227 * this up later, so allow that.
10229 if (!move_group && group_leader->ctx != ctx)
10233 * Only a group leader can be exclusive or pinned
10235 if (attr.exclusive || attr.pinned)
10239 if (output_event) {
10240 err = perf_event_set_output(event, output_event);
10245 event_file = anon_inode_getfile("[perf_event]", &perf_fops, event,
10247 if (IS_ERR(event_file)) {
10248 err = PTR_ERR(event_file);
10254 gctx = __perf_event_ctx_lock_double(group_leader, ctx);
10256 if (gctx->task == TASK_TOMBSTONE) {
10262 * Check if we raced against another sys_perf_event_open() call
10263 * moving the software group underneath us.
10265 if (!(group_leader->group_caps & PERF_EV_CAP_SOFTWARE)) {
10267 * If someone moved the group out from under us, check
10268 * if this new event wound up on the same ctx, if so
10269 * its the regular !move_group case, otherwise fail.
10275 perf_event_ctx_unlock(group_leader, gctx);
10280 mutex_lock(&ctx->mutex);
10283 if (ctx->task == TASK_TOMBSTONE) {
10288 if (!perf_event_validate_size(event)) {
10295 * Check if the @cpu we're creating an event for is online.
10297 * We use the perf_cpu_context::ctx::mutex to serialize against
10298 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10300 struct perf_cpu_context *cpuctx =
10301 container_of(ctx, struct perf_cpu_context, ctx);
10303 if (!cpuctx->online) {
10311 * Must be under the same ctx::mutex as perf_install_in_context(),
10312 * because we need to serialize with concurrent event creation.
10314 if (!exclusive_event_installable(event, ctx)) {
10315 /* exclusive and group stuff are assumed mutually exclusive */
10316 WARN_ON_ONCE(move_group);
10322 WARN_ON_ONCE(ctx->parent_ctx);
10325 * This is the point on no return; we cannot fail hereafter. This is
10326 * where we start modifying current state.
10331 * See perf_event_ctx_lock() for comments on the details
10332 * of swizzling perf_event::ctx.
10334 perf_remove_from_context(group_leader, 0);
10337 list_for_each_entry(sibling, &group_leader->sibling_list,
10339 perf_remove_from_context(sibling, 0);
10344 * Wait for everybody to stop referencing the events through
10345 * the old lists, before installing it on new lists.
10350 * Install the group siblings before the group leader.
10352 * Because a group leader will try and install the entire group
10353 * (through the sibling list, which is still in-tact), we can
10354 * end up with siblings installed in the wrong context.
10356 * By installing siblings first we NO-OP because they're not
10357 * reachable through the group lists.
10359 list_for_each_entry(sibling, &group_leader->sibling_list,
10361 perf_event__state_init(sibling);
10362 perf_install_in_context(ctx, sibling, sibling->cpu);
10367 * Removing from the context ends up with disabled
10368 * event. What we want here is event in the initial
10369 * startup state, ready to be add into new context.
10371 perf_event__state_init(group_leader);
10372 perf_install_in_context(ctx, group_leader, group_leader->cpu);
10377 * Precalculate sample_data sizes; do while holding ctx::mutex such
10378 * that we're serialized against further additions and before
10379 * perf_install_in_context() which is the point the event is active and
10380 * can use these values.
10382 perf_event__header_size(event);
10383 perf_event__id_header_size(event);
10385 event->owner = current;
10387 perf_install_in_context(ctx, event, event->cpu);
10388 perf_unpin_context(ctx);
10391 perf_event_ctx_unlock(group_leader, gctx);
10392 mutex_unlock(&ctx->mutex);
10395 mutex_unlock(&task->signal->cred_guard_mutex);
10396 put_task_struct(task);
10399 mutex_lock(¤t->perf_event_mutex);
10400 list_add_tail(&event->owner_entry, ¤t->perf_event_list);
10401 mutex_unlock(¤t->perf_event_mutex);
10404 * Drop the reference on the group_event after placing the
10405 * new event on the sibling_list. This ensures destruction
10406 * of the group leader will find the pointer to itself in
10407 * perf_group_detach().
10410 fd_install(event_fd, event_file);
10415 perf_event_ctx_unlock(group_leader, gctx);
10416 mutex_unlock(&ctx->mutex);
10420 perf_unpin_context(ctx);
10424 * If event_file is set, the fput() above will have called ->release()
10425 * and that will take care of freeing the event.
10431 mutex_unlock(&task->signal->cred_guard_mutex);
10434 put_task_struct(task);
10438 put_unused_fd(event_fd);
10443 * perf_event_create_kernel_counter
10445 * @attr: attributes of the counter to create
10446 * @cpu: cpu in which the counter is bound
10447 * @task: task to profile (NULL for percpu)
10449 struct perf_event *
10450 perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
10451 struct task_struct *task,
10452 perf_overflow_handler_t overflow_handler,
10455 struct perf_event_context *ctx;
10456 struct perf_event *event;
10460 * Get the target context (task or percpu):
10463 event = perf_event_alloc(attr, cpu, task, NULL, NULL,
10464 overflow_handler, context, -1);
10465 if (IS_ERR(event)) {
10466 err = PTR_ERR(event);
10470 /* Mark owner so we could distinguish it from user events. */
10471 event->owner = TASK_TOMBSTONE;
10473 ctx = find_get_context(event->pmu, task, event);
10475 err = PTR_ERR(ctx);
10479 WARN_ON_ONCE(ctx->parent_ctx);
10480 mutex_lock(&ctx->mutex);
10481 if (ctx->task == TASK_TOMBSTONE) {
10488 * Check if the @cpu we're creating an event for is online.
10490 * We use the perf_cpu_context::ctx::mutex to serialize against
10491 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10493 struct perf_cpu_context *cpuctx =
10494 container_of(ctx, struct perf_cpu_context, ctx);
10495 if (!cpuctx->online) {
10501 if (!exclusive_event_installable(event, ctx)) {
10506 perf_install_in_context(ctx, event, event->cpu);
10507 perf_unpin_context(ctx);
10508 mutex_unlock(&ctx->mutex);
10513 mutex_unlock(&ctx->mutex);
10514 perf_unpin_context(ctx);
10519 return ERR_PTR(err);
10521 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
10523 void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
10525 struct perf_event_context *src_ctx;
10526 struct perf_event_context *dst_ctx;
10527 struct perf_event *event, *tmp;
10530 src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx;
10531 dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx;
10534 * See perf_event_ctx_lock() for comments on the details
10535 * of swizzling perf_event::ctx.
10537 mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex);
10538 list_for_each_entry_safe(event, tmp, &src_ctx->event_list,
10540 perf_remove_from_context(event, 0);
10541 unaccount_event_cpu(event, src_cpu);
10543 list_add(&event->migrate_entry, &events);
10547 * Wait for the events to quiesce before re-instating them.
10552 * Re-instate events in 2 passes.
10554 * Skip over group leaders and only install siblings on this first
10555 * pass, siblings will not get enabled without a leader, however a
10556 * leader will enable its siblings, even if those are still on the old
10559 list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
10560 if (event->group_leader == event)
10563 list_del(&event->migrate_entry);
10564 if (event->state >= PERF_EVENT_STATE_OFF)
10565 event->state = PERF_EVENT_STATE_INACTIVE;
10566 account_event_cpu(event, dst_cpu);
10567 perf_install_in_context(dst_ctx, event, dst_cpu);
10572 * Once all the siblings are setup properly, install the group leaders
10575 list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
10576 list_del(&event->migrate_entry);
10577 if (event->state >= PERF_EVENT_STATE_OFF)
10578 event->state = PERF_EVENT_STATE_INACTIVE;
10579 account_event_cpu(event, dst_cpu);
10580 perf_install_in_context(dst_ctx, event, dst_cpu);
10583 mutex_unlock(&dst_ctx->mutex);
10584 mutex_unlock(&src_ctx->mutex);
10586 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
10588 static void sync_child_event(struct perf_event *child_event,
10589 struct task_struct *child)
10591 struct perf_event *parent_event = child_event->parent;
10594 if (child_event->attr.inherit_stat)
10595 perf_event_read_event(child_event, child);
10597 child_val = perf_event_count(child_event);
10600 * Add back the child's count to the parent's count:
10602 atomic64_add(child_val, &parent_event->child_count);
10603 atomic64_add(child_event->total_time_enabled,
10604 &parent_event->child_total_time_enabled);
10605 atomic64_add(child_event->total_time_running,
10606 &parent_event->child_total_time_running);
10610 perf_event_exit_event(struct perf_event *child_event,
10611 struct perf_event_context *child_ctx,
10612 struct task_struct *child)
10614 struct perf_event *parent_event = child_event->parent;
10617 * Do not destroy the 'original' grouping; because of the context
10618 * switch optimization the original events could've ended up in a
10619 * random child task.
10621 * If we were to destroy the original group, all group related
10622 * operations would cease to function properly after this random
10625 * Do destroy all inherited groups, we don't care about those
10626 * and being thorough is better.
10628 raw_spin_lock_irq(&child_ctx->lock);
10629 WARN_ON_ONCE(child_ctx->is_active);
10632 perf_group_detach(child_event);
10633 list_del_event(child_event, child_ctx);
10634 child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */
10635 raw_spin_unlock_irq(&child_ctx->lock);
10638 * Parent events are governed by their filedesc, retain them.
10640 if (!parent_event) {
10641 perf_event_wakeup(child_event);
10645 * Child events can be cleaned up.
10648 sync_child_event(child_event, child);
10651 * Remove this event from the parent's list
10653 WARN_ON_ONCE(parent_event->ctx->parent_ctx);
10654 mutex_lock(&parent_event->child_mutex);
10655 list_del_init(&child_event->child_list);
10656 mutex_unlock(&parent_event->child_mutex);
10659 * Kick perf_poll() for is_event_hup().
10661 perf_event_wakeup(parent_event);
10662 free_event(child_event);
10663 put_event(parent_event);
10666 static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
10668 struct perf_event_context *child_ctx, *clone_ctx = NULL;
10669 struct perf_event *child_event, *next;
10671 WARN_ON_ONCE(child != current);
10673 child_ctx = perf_pin_task_context(child, ctxn);
10678 * In order to reduce the amount of tricky in ctx tear-down, we hold
10679 * ctx::mutex over the entire thing. This serializes against almost
10680 * everything that wants to access the ctx.
10682 * The exception is sys_perf_event_open() /
10683 * perf_event_create_kernel_count() which does find_get_context()
10684 * without ctx::mutex (it cannot because of the move_group double mutex
10685 * lock thing). See the comments in perf_install_in_context().
10687 mutex_lock(&child_ctx->mutex);
10690 * In a single ctx::lock section, de-schedule the events and detach the
10691 * context from the task such that we cannot ever get it scheduled back
10694 raw_spin_lock_irq(&child_ctx->lock);
10695 task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx, EVENT_ALL);
10698 * Now that the context is inactive, destroy the task <-> ctx relation
10699 * and mark the context dead.
10701 RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL);
10702 put_ctx(child_ctx); /* cannot be last */
10703 WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE);
10704 put_task_struct(current); /* cannot be last */
10706 clone_ctx = unclone_ctx(child_ctx);
10707 raw_spin_unlock_irq(&child_ctx->lock);
10710 put_ctx(clone_ctx);
10713 * Report the task dead after unscheduling the events so that we
10714 * won't get any samples after PERF_RECORD_EXIT. We can however still
10715 * get a few PERF_RECORD_READ events.
10717 perf_event_task(child, child_ctx, 0);
10719 list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry)
10720 perf_event_exit_event(child_event, child_ctx, child);
10722 mutex_unlock(&child_ctx->mutex);
10724 put_ctx(child_ctx);
10728 * When a child task exits, feed back event values to parent events.
10730 * Can be called with cred_guard_mutex held when called from
10731 * install_exec_creds().
10733 void perf_event_exit_task(struct task_struct *child)
10735 struct perf_event *event, *tmp;
10738 mutex_lock(&child->perf_event_mutex);
10739 list_for_each_entry_safe(event, tmp, &child->perf_event_list,
10741 list_del_init(&event->owner_entry);
10744 * Ensure the list deletion is visible before we clear
10745 * the owner, closes a race against perf_release() where
10746 * we need to serialize on the owner->perf_event_mutex.
10748 smp_store_release(&event->owner, NULL);
10750 mutex_unlock(&child->perf_event_mutex);
10752 for_each_task_context_nr(ctxn)
10753 perf_event_exit_task_context(child, ctxn);
10756 * The perf_event_exit_task_context calls perf_event_task
10757 * with child's task_ctx, which generates EXIT events for
10758 * child contexts and sets child->perf_event_ctxp[] to NULL.
10759 * At this point we need to send EXIT events to cpu contexts.
10761 perf_event_task(child, NULL, 0);
10764 static void perf_free_event(struct perf_event *event,
10765 struct perf_event_context *ctx)
10767 struct perf_event *parent = event->parent;
10769 if (WARN_ON_ONCE(!parent))
10772 mutex_lock(&parent->child_mutex);
10773 list_del_init(&event->child_list);
10774 mutex_unlock(&parent->child_mutex);
10778 raw_spin_lock_irq(&ctx->lock);
10779 perf_group_detach(event);
10780 list_del_event(event, ctx);
10781 raw_spin_unlock_irq(&ctx->lock);
10786 * Free an unexposed, unused context as created by inheritance by
10787 * perf_event_init_task below, used by fork() in case of fail.
10789 * Not all locks are strictly required, but take them anyway to be nice and
10790 * help out with the lockdep assertions.
10792 void perf_event_free_task(struct task_struct *task)
10794 struct perf_event_context *ctx;
10795 struct perf_event *event, *tmp;
10798 for_each_task_context_nr(ctxn) {
10799 ctx = task->perf_event_ctxp[ctxn];
10803 mutex_lock(&ctx->mutex);
10804 raw_spin_lock_irq(&ctx->lock);
10806 * Destroy the task <-> ctx relation and mark the context dead.
10808 * This is important because even though the task hasn't been
10809 * exposed yet the context has been (through child_list).
10811 RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], NULL);
10812 WRITE_ONCE(ctx->task, TASK_TOMBSTONE);
10813 put_task_struct(task); /* cannot be last */
10814 raw_spin_unlock_irq(&ctx->lock);
10816 list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry)
10817 perf_free_event(event, ctx);
10819 mutex_unlock(&ctx->mutex);
10824 void perf_event_delayed_put(struct task_struct *task)
10828 for_each_task_context_nr(ctxn)
10829 WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
10832 struct file *perf_event_get(unsigned int fd)
10836 file = fget_raw(fd);
10838 return ERR_PTR(-EBADF);
10840 if (file->f_op != &perf_fops) {
10842 return ERR_PTR(-EBADF);
10848 const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
10851 return ERR_PTR(-EINVAL);
10853 return &event->attr;
10857 * Inherit a event from parent task to child task.
10860 * - valid pointer on success
10861 * - NULL for orphaned events
10862 * - IS_ERR() on error
10864 static struct perf_event *
10865 inherit_event(struct perf_event *parent_event,
10866 struct task_struct *parent,
10867 struct perf_event_context *parent_ctx,
10868 struct task_struct *child,
10869 struct perf_event *group_leader,
10870 struct perf_event_context *child_ctx)
10872 enum perf_event_active_state parent_state = parent_event->state;
10873 struct perf_event *child_event;
10874 unsigned long flags;
10877 * Instead of creating recursive hierarchies of events,
10878 * we link inherited events back to the original parent,
10879 * which has a filp for sure, which we use as the reference
10882 if (parent_event->parent)
10883 parent_event = parent_event->parent;
10885 child_event = perf_event_alloc(&parent_event->attr,
10888 group_leader, parent_event,
10890 if (IS_ERR(child_event))
10891 return child_event;
10894 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10895 * must be under the same lock in order to serialize against
10896 * perf_event_release_kernel(), such that either we must observe
10897 * is_orphaned_event() or they will observe us on the child_list.
10899 mutex_lock(&parent_event->child_mutex);
10900 if (is_orphaned_event(parent_event) ||
10901 !atomic_long_inc_not_zero(&parent_event->refcount)) {
10902 mutex_unlock(&parent_event->child_mutex);
10903 free_event(child_event);
10907 get_ctx(child_ctx);
10910 * Make the child state follow the state of the parent event,
10911 * not its attr.disabled bit. We hold the parent's mutex,
10912 * so we won't race with perf_event_{en, dis}able_family.
10914 if (parent_state >= PERF_EVENT_STATE_INACTIVE)
10915 child_event->state = PERF_EVENT_STATE_INACTIVE;
10917 child_event->state = PERF_EVENT_STATE_OFF;
10919 if (parent_event->attr.freq) {
10920 u64 sample_period = parent_event->hw.sample_period;
10921 struct hw_perf_event *hwc = &child_event->hw;
10923 hwc->sample_period = sample_period;
10924 hwc->last_period = sample_period;
10926 local64_set(&hwc->period_left, sample_period);
10929 child_event->ctx = child_ctx;
10930 child_event->overflow_handler = parent_event->overflow_handler;
10931 child_event->overflow_handler_context
10932 = parent_event->overflow_handler_context;
10935 * Precalculate sample_data sizes
10937 perf_event__header_size(child_event);
10938 perf_event__id_header_size(child_event);
10941 * Link it up in the child's context:
10943 raw_spin_lock_irqsave(&child_ctx->lock, flags);
10944 add_event_to_ctx(child_event, child_ctx);
10945 raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
10948 * Link this into the parent event's child list
10950 list_add_tail(&child_event->child_list, &parent_event->child_list);
10951 mutex_unlock(&parent_event->child_mutex);
10953 return child_event;
10957 * Inherits an event group.
10959 * This will quietly suppress orphaned events; !inherit_event() is not an error.
10960 * This matches with perf_event_release_kernel() removing all child events.
10966 static int inherit_group(struct perf_event *parent_event,
10967 struct task_struct *parent,
10968 struct perf_event_context *parent_ctx,
10969 struct task_struct *child,
10970 struct perf_event_context *child_ctx)
10972 struct perf_event *leader;
10973 struct perf_event *sub;
10974 struct perf_event *child_ctr;
10976 leader = inherit_event(parent_event, parent, parent_ctx,
10977 child, NULL, child_ctx);
10978 if (IS_ERR(leader))
10979 return PTR_ERR(leader);
10981 * @leader can be NULL here because of is_orphaned_event(). In this
10982 * case inherit_event() will create individual events, similar to what
10983 * perf_group_detach() would do anyway.
10985 list_for_each_entry(sub, &parent_event->sibling_list, group_entry) {
10986 child_ctr = inherit_event(sub, parent, parent_ctx,
10987 child, leader, child_ctx);
10988 if (IS_ERR(child_ctr))
10989 return PTR_ERR(child_ctr);
10995 * Creates the child task context and tries to inherit the event-group.
10997 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
10998 * inherited_all set when we 'fail' to inherit an orphaned event; this is
10999 * consistent with perf_event_release_kernel() removing all child events.
11006 inherit_task_group(struct perf_event *event, struct task_struct *parent,
11007 struct perf_event_context *parent_ctx,
11008 struct task_struct *child, int ctxn,
11009 int *inherited_all)
11012 struct perf_event_context *child_ctx;
11014 if (!event->attr.inherit) {
11015 *inherited_all = 0;
11019 child_ctx = child->perf_event_ctxp[ctxn];
11022 * This is executed from the parent task context, so
11023 * inherit events that have been marked for cloning.
11024 * First allocate and initialize a context for the
11027 child_ctx = alloc_perf_context(parent_ctx->pmu, child);
11031 child->perf_event_ctxp[ctxn] = child_ctx;
11034 ret = inherit_group(event, parent, parent_ctx,
11038 *inherited_all = 0;
11044 * Initialize the perf_event context in task_struct
11046 static int perf_event_init_context(struct task_struct *child, int ctxn)
11048 struct perf_event_context *child_ctx, *parent_ctx;
11049 struct perf_event_context *cloned_ctx;
11050 struct perf_event *event;
11051 struct task_struct *parent = current;
11052 int inherited_all = 1;
11053 unsigned long flags;
11056 if (likely(!parent->perf_event_ctxp[ctxn]))
11060 * If the parent's context is a clone, pin it so it won't get
11061 * swapped under us.
11063 parent_ctx = perf_pin_task_context(parent, ctxn);
11068 * No need to check if parent_ctx != NULL here; since we saw
11069 * it non-NULL earlier, the only reason for it to become NULL
11070 * is if we exit, and since we're currently in the middle of
11071 * a fork we can't be exiting at the same time.
11075 * Lock the parent list. No need to lock the child - not PID
11076 * hashed yet and not running, so nobody can access it.
11078 mutex_lock(&parent_ctx->mutex);
11081 * We dont have to disable NMIs - we are only looking at
11082 * the list, not manipulating it:
11084 list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) {
11085 ret = inherit_task_group(event, parent, parent_ctx,
11086 child, ctxn, &inherited_all);
11092 * We can't hold ctx->lock when iterating the ->flexible_group list due
11093 * to allocations, but we need to prevent rotation because
11094 * rotate_ctx() will change the list from interrupt context.
11096 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
11097 parent_ctx->rotate_disable = 1;
11098 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
11100 list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) {
11101 ret = inherit_task_group(event, parent, parent_ctx,
11102 child, ctxn, &inherited_all);
11107 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
11108 parent_ctx->rotate_disable = 0;
11110 child_ctx = child->perf_event_ctxp[ctxn];
11112 if (child_ctx && inherited_all) {
11114 * Mark the child context as a clone of the parent
11115 * context, or of whatever the parent is a clone of.
11117 * Note that if the parent is a clone, the holding of
11118 * parent_ctx->lock avoids it from being uncloned.
11120 cloned_ctx = parent_ctx->parent_ctx;
11122 child_ctx->parent_ctx = cloned_ctx;
11123 child_ctx->parent_gen = parent_ctx->parent_gen;
11125 child_ctx->parent_ctx = parent_ctx;
11126 child_ctx->parent_gen = parent_ctx->generation;
11128 get_ctx(child_ctx->parent_ctx);
11131 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
11133 mutex_unlock(&parent_ctx->mutex);
11135 perf_unpin_context(parent_ctx);
11136 put_ctx(parent_ctx);
11142 * Initialize the perf_event context in task_struct
11144 int perf_event_init_task(struct task_struct *child)
11148 memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
11149 mutex_init(&child->perf_event_mutex);
11150 INIT_LIST_HEAD(&child->perf_event_list);
11152 for_each_task_context_nr(ctxn) {
11153 ret = perf_event_init_context(child, ctxn);
11155 perf_event_free_task(child);
11163 static void __init perf_event_init_all_cpus(void)
11165 struct swevent_htable *swhash;
11168 zalloc_cpumask_var(&perf_online_mask, GFP_KERNEL);
11170 for_each_possible_cpu(cpu) {
11171 swhash = &per_cpu(swevent_htable, cpu);
11172 mutex_init(&swhash->hlist_mutex);
11173 INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu));
11175 INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu));
11176 raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu));
11178 #ifdef CONFIG_CGROUP_PERF
11179 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list, cpu));
11181 INIT_LIST_HEAD(&per_cpu(sched_cb_list, cpu));
11185 void perf_swevent_init_cpu(unsigned int cpu)
11187 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
11189 mutex_lock(&swhash->hlist_mutex);
11190 if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) {
11191 struct swevent_hlist *hlist;
11193 hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
11195 rcu_assign_pointer(swhash->swevent_hlist, hlist);
11197 mutex_unlock(&swhash->hlist_mutex);
11200 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
11201 static void __perf_event_exit_context(void *__info)
11203 struct perf_event_context *ctx = __info;
11204 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
11205 struct perf_event *event;
11207 raw_spin_lock(&ctx->lock);
11208 list_for_each_entry(event, &ctx->event_list, event_entry)
11209 __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP);
11210 raw_spin_unlock(&ctx->lock);
11213 static void perf_event_exit_cpu_context(int cpu)
11215 struct perf_cpu_context *cpuctx;
11216 struct perf_event_context *ctx;
11219 mutex_lock(&pmus_lock);
11220 list_for_each_entry(pmu, &pmus, entry) {
11221 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
11222 ctx = &cpuctx->ctx;
11224 mutex_lock(&ctx->mutex);
11225 smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
11226 cpuctx->online = 0;
11227 mutex_unlock(&ctx->mutex);
11229 cpumask_clear_cpu(cpu, perf_online_mask);
11230 mutex_unlock(&pmus_lock);
11234 static void perf_event_exit_cpu_context(int cpu) { }
11238 int perf_event_init_cpu(unsigned int cpu)
11240 struct perf_cpu_context *cpuctx;
11241 struct perf_event_context *ctx;
11244 perf_swevent_init_cpu(cpu);
11246 mutex_lock(&pmus_lock);
11247 cpumask_set_cpu(cpu, perf_online_mask);
11248 list_for_each_entry(pmu, &pmus, entry) {
11249 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
11250 ctx = &cpuctx->ctx;
11252 mutex_lock(&ctx->mutex);
11253 cpuctx->online = 1;
11254 mutex_unlock(&ctx->mutex);
11256 mutex_unlock(&pmus_lock);
11261 int perf_event_exit_cpu(unsigned int cpu)
11263 perf_event_exit_cpu_context(cpu);
11268 perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
11272 for_each_online_cpu(cpu)
11273 perf_event_exit_cpu(cpu);
11279 * Run the perf reboot notifier at the very last possible moment so that
11280 * the generic watchdog code runs as long as possible.
11282 static struct notifier_block perf_reboot_notifier = {
11283 .notifier_call = perf_reboot,
11284 .priority = INT_MIN,
11287 void __init perf_event_init(void)
11291 idr_init(&pmu_idr);
11293 perf_event_init_all_cpus();
11294 init_srcu_struct(&pmus_srcu);
11295 perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
11296 perf_pmu_register(&perf_cpu_clock, NULL, -1);
11297 perf_pmu_register(&perf_task_clock, NULL, -1);
11298 perf_tp_register();
11299 perf_event_init_cpu(smp_processor_id());
11300 register_reboot_notifier(&perf_reboot_notifier);
11302 ret = init_hw_breakpoint();
11303 WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
11306 * Build time assertion that we keep the data_head at the intended
11307 * location. IOW, validation we got the __reserved[] size right.
11309 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head))
11313 ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
11316 struct perf_pmu_events_attr *pmu_attr =
11317 container_of(attr, struct perf_pmu_events_attr, attr);
11319 if (pmu_attr->event_str)
11320 return sprintf(page, "%s\n", pmu_attr->event_str);
11324 EXPORT_SYMBOL_GPL(perf_event_sysfs_show);
11326 static int __init perf_event_sysfs_init(void)
11331 mutex_lock(&pmus_lock);
11333 ret = bus_register(&pmu_bus);
11337 list_for_each_entry(pmu, &pmus, entry) {
11338 if (!pmu->name || pmu->type < 0)
11341 ret = pmu_dev_alloc(pmu);
11342 WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret);
11344 pmu_bus_running = 1;
11348 mutex_unlock(&pmus_lock);
11352 device_initcall(perf_event_sysfs_init);
11354 #ifdef CONFIG_CGROUP_PERF
11355 static struct cgroup_subsys_state *
11356 perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
11358 struct perf_cgroup *jc;
11360 jc = kzalloc(sizeof(*jc), GFP_KERNEL);
11362 return ERR_PTR(-ENOMEM);
11364 jc->info = alloc_percpu(struct perf_cgroup_info);
11367 return ERR_PTR(-ENOMEM);
11373 static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
11375 struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css);
11377 free_percpu(jc->info);
11381 static int __perf_cgroup_move(void *info)
11383 struct task_struct *task = info;
11385 perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN);
11390 static void perf_cgroup_attach(struct cgroup_taskset *tset)
11392 struct task_struct *task;
11393 struct cgroup_subsys_state *css;
11395 cgroup_taskset_for_each(task, css, tset)
11396 task_function_call(task, __perf_cgroup_move, task);
11399 struct cgroup_subsys perf_event_cgrp_subsys = {
11400 .css_alloc = perf_cgroup_css_alloc,
11401 .css_free = perf_cgroup_css_free,
11402 .attach = perf_cgroup_attach,
11404 * Implicitly enable on dfl hierarchy so that perf events can
11405 * always be filtered by cgroup2 path as long as perf_event
11406 * controller is not mounted on a legacy hierarchy.
11408 .implicit_on_dfl = true,
11411 #endif /* CONFIG_CGROUP_PERF */