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>
52 #include <asm/irq_regs.h>
54 typedef int (*remote_function_f)(void *);
56 struct remote_function_call {
57 struct task_struct *p;
58 remote_function_f func;
63 static void remote_function(void *data)
65 struct remote_function_call *tfc = data;
66 struct task_struct *p = tfc->p;
70 if (task_cpu(p) != smp_processor_id())
74 * Now that we're on right CPU with IRQs disabled, we can test
75 * if we hit the right task without races.
78 tfc->ret = -ESRCH; /* No such (running) process */
83 tfc->ret = tfc->func(tfc->info);
87 * task_function_call - call a function on the cpu on which a task runs
88 * @p: the task to evaluate
89 * @func: the function to be called
90 * @info: the function call argument
92 * Calls the function @func when the task is currently running. This might
93 * be on the current CPU, which just calls the function directly
95 * returns: @func return value, or
96 * -ESRCH - when the process isn't running
97 * -EAGAIN - when the process moved away
100 task_function_call(struct task_struct *p, remote_function_f func, void *info)
102 struct remote_function_call data = {
111 ret = smp_call_function_single(task_cpu(p), remote_function, &data, 1);
114 } while (ret == -EAGAIN);
120 * cpu_function_call - call a function on the cpu
121 * @func: the function to be called
122 * @info: the function call argument
124 * Calls the function @func on the remote cpu.
126 * returns: @func return value or -ENXIO when the cpu is offline
128 static int cpu_function_call(int cpu, remote_function_f func, void *info)
130 struct remote_function_call data = {
134 .ret = -ENXIO, /* No such CPU */
137 smp_call_function_single(cpu, remote_function, &data, 1);
142 static inline struct perf_cpu_context *
143 __get_cpu_context(struct perf_event_context *ctx)
145 return this_cpu_ptr(ctx->pmu->pmu_cpu_context);
148 static void perf_ctx_lock(struct perf_cpu_context *cpuctx,
149 struct perf_event_context *ctx)
151 raw_spin_lock(&cpuctx->ctx.lock);
153 raw_spin_lock(&ctx->lock);
156 static void perf_ctx_unlock(struct perf_cpu_context *cpuctx,
157 struct perf_event_context *ctx)
160 raw_spin_unlock(&ctx->lock);
161 raw_spin_unlock(&cpuctx->ctx.lock);
164 #define TASK_TOMBSTONE ((void *)-1L)
166 static bool is_kernel_event(struct perf_event *event)
168 return READ_ONCE(event->owner) == TASK_TOMBSTONE;
172 * On task ctx scheduling...
174 * When !ctx->nr_events a task context will not be scheduled. This means
175 * we can disable the scheduler hooks (for performance) without leaving
176 * pending task ctx state.
178 * This however results in two special cases:
180 * - removing the last event from a task ctx; this is relatively straight
181 * forward and is done in __perf_remove_from_context.
183 * - adding the first event to a task ctx; this is tricky because we cannot
184 * rely on ctx->is_active and therefore cannot use event_function_call().
185 * See perf_install_in_context().
187 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
190 typedef void (*event_f)(struct perf_event *, struct perf_cpu_context *,
191 struct perf_event_context *, void *);
193 struct event_function_struct {
194 struct perf_event *event;
199 static int event_function(void *info)
201 struct event_function_struct *efs = info;
202 struct perf_event *event = efs->event;
203 struct perf_event_context *ctx = event->ctx;
204 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
205 struct perf_event_context *task_ctx = cpuctx->task_ctx;
208 WARN_ON_ONCE(!irqs_disabled());
210 perf_ctx_lock(cpuctx, task_ctx);
212 * Since we do the IPI call without holding ctx->lock things can have
213 * changed, double check we hit the task we set out to hit.
216 if (ctx->task != current) {
222 * We only use event_function_call() on established contexts,
223 * and event_function() is only ever called when active (or
224 * rather, we'll have bailed in task_function_call() or the
225 * above ctx->task != current test), therefore we must have
226 * ctx->is_active here.
228 WARN_ON_ONCE(!ctx->is_active);
230 * And since we have ctx->is_active, cpuctx->task_ctx must
233 WARN_ON_ONCE(task_ctx != ctx);
235 WARN_ON_ONCE(&cpuctx->ctx != ctx);
238 efs->func(event, cpuctx, ctx, efs->data);
240 perf_ctx_unlock(cpuctx, task_ctx);
245 static void event_function_call(struct perf_event *event, event_f func, void *data)
247 struct perf_event_context *ctx = event->ctx;
248 struct task_struct *task = READ_ONCE(ctx->task); /* verified in event_function */
249 struct event_function_struct efs = {
255 if (!event->parent) {
257 * If this is a !child event, we must hold ctx::mutex to
258 * stabilize the the event->ctx relation. See
259 * perf_event_ctx_lock().
261 lockdep_assert_held(&ctx->mutex);
265 cpu_function_call(event->cpu, event_function, &efs);
269 if (task == TASK_TOMBSTONE)
273 if (!task_function_call(task, event_function, &efs))
276 raw_spin_lock_irq(&ctx->lock);
278 * Reload the task pointer, it might have been changed by
279 * a concurrent perf_event_context_sched_out().
282 if (task == TASK_TOMBSTONE) {
283 raw_spin_unlock_irq(&ctx->lock);
286 if (ctx->is_active) {
287 raw_spin_unlock_irq(&ctx->lock);
290 func(event, NULL, ctx, data);
291 raw_spin_unlock_irq(&ctx->lock);
295 * Similar to event_function_call() + event_function(), but hard assumes IRQs
296 * are already disabled and we're on the right CPU.
298 static void event_function_local(struct perf_event *event, event_f func, void *data)
300 struct perf_event_context *ctx = event->ctx;
301 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
302 struct task_struct *task = READ_ONCE(ctx->task);
303 struct perf_event_context *task_ctx = NULL;
305 WARN_ON_ONCE(!irqs_disabled());
308 if (task == TASK_TOMBSTONE)
314 perf_ctx_lock(cpuctx, task_ctx);
317 if (task == TASK_TOMBSTONE)
322 * We must be either inactive or active and the right task,
323 * otherwise we're screwed, since we cannot IPI to somewhere
326 if (ctx->is_active) {
327 if (WARN_ON_ONCE(task != current))
330 if (WARN_ON_ONCE(cpuctx->task_ctx != ctx))
334 WARN_ON_ONCE(&cpuctx->ctx != ctx);
337 func(event, cpuctx, ctx, data);
339 perf_ctx_unlock(cpuctx, task_ctx);
342 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
343 PERF_FLAG_FD_OUTPUT |\
344 PERF_FLAG_PID_CGROUP |\
345 PERF_FLAG_FD_CLOEXEC)
348 * branch priv levels that need permission checks
350 #define PERF_SAMPLE_BRANCH_PERM_PLM \
351 (PERF_SAMPLE_BRANCH_KERNEL |\
352 PERF_SAMPLE_BRANCH_HV)
355 EVENT_FLEXIBLE = 0x1,
358 EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
362 * perf_sched_events : >0 events exist
363 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
366 static void perf_sched_delayed(struct work_struct *work);
367 DEFINE_STATIC_KEY_FALSE(perf_sched_events);
368 static DECLARE_DELAYED_WORK(perf_sched_work, perf_sched_delayed);
369 static DEFINE_MUTEX(perf_sched_mutex);
370 static atomic_t perf_sched_count;
372 static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
373 static DEFINE_PER_CPU(int, perf_sched_cb_usages);
374 static DEFINE_PER_CPU(struct pmu_event_list, pmu_sb_events);
376 static atomic_t nr_mmap_events __read_mostly;
377 static atomic_t nr_comm_events __read_mostly;
378 static atomic_t nr_task_events __read_mostly;
379 static atomic_t nr_freq_events __read_mostly;
380 static atomic_t nr_switch_events __read_mostly;
382 static LIST_HEAD(pmus);
383 static DEFINE_MUTEX(pmus_lock);
384 static struct srcu_struct pmus_srcu;
387 * perf event paranoia level:
388 * -1 - not paranoid at all
389 * 0 - disallow raw tracepoint access for unpriv
390 * 1 - disallow cpu events for unpriv
391 * 2 - disallow kernel profiling for unpriv
393 int sysctl_perf_event_paranoid __read_mostly = 2;
395 /* Minimum for 512 kiB + 1 user control page */
396 int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */
399 * max perf event sample rate
401 #define DEFAULT_MAX_SAMPLE_RATE 100000
402 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
403 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
405 int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE;
407 static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ);
408 static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS;
410 static int perf_sample_allowed_ns __read_mostly =
411 DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100;
413 static void update_perf_cpu_limits(void)
415 u64 tmp = perf_sample_period_ns;
417 tmp *= sysctl_perf_cpu_time_max_percent;
418 tmp = div_u64(tmp, 100);
422 WRITE_ONCE(perf_sample_allowed_ns, tmp);
425 static int perf_rotate_context(struct perf_cpu_context *cpuctx);
427 int perf_proc_update_handler(struct ctl_table *table, int write,
428 void __user *buffer, size_t *lenp,
431 int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
437 * If throttling is disabled don't allow the write:
439 if (sysctl_perf_cpu_time_max_percent == 100 ||
440 sysctl_perf_cpu_time_max_percent == 0)
443 max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ);
444 perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
445 update_perf_cpu_limits();
450 int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;
452 int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
453 void __user *buffer, size_t *lenp,
456 int ret = proc_dointvec(table, write, buffer, lenp, ppos);
461 if (sysctl_perf_cpu_time_max_percent == 100 ||
462 sysctl_perf_cpu_time_max_percent == 0) {
464 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
465 WRITE_ONCE(perf_sample_allowed_ns, 0);
467 update_perf_cpu_limits();
474 * perf samples are done in some very critical code paths (NMIs).
475 * If they take too much CPU time, the system can lock up and not
476 * get any real work done. This will drop the sample rate when
477 * we detect that events are taking too long.
479 #define NR_ACCUMULATED_SAMPLES 128
480 static DEFINE_PER_CPU(u64, running_sample_length);
482 static u64 __report_avg;
483 static u64 __report_allowed;
485 static void perf_duration_warn(struct irq_work *w)
487 printk_ratelimited(KERN_INFO
488 "perf: interrupt took too long (%lld > %lld), lowering "
489 "kernel.perf_event_max_sample_rate to %d\n",
490 __report_avg, __report_allowed,
491 sysctl_perf_event_sample_rate);
494 static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn);
496 void perf_sample_event_took(u64 sample_len_ns)
498 u64 max_len = READ_ONCE(perf_sample_allowed_ns);
506 /* Decay the counter by 1 average sample. */
507 running_len = __this_cpu_read(running_sample_length);
508 running_len -= running_len/NR_ACCUMULATED_SAMPLES;
509 running_len += sample_len_ns;
510 __this_cpu_write(running_sample_length, running_len);
513 * Note: this will be biased artifically low until we have
514 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
515 * from having to maintain a count.
517 avg_len = running_len/NR_ACCUMULATED_SAMPLES;
518 if (avg_len <= max_len)
521 __report_avg = avg_len;
522 __report_allowed = max_len;
525 * Compute a throttle threshold 25% below the current duration.
527 avg_len += avg_len / 4;
528 max = (TICK_NSEC / 100) * sysctl_perf_cpu_time_max_percent;
534 WRITE_ONCE(perf_sample_allowed_ns, avg_len);
535 WRITE_ONCE(max_samples_per_tick, max);
537 sysctl_perf_event_sample_rate = max * HZ;
538 perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
540 if (!irq_work_queue(&perf_duration_work)) {
541 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
542 "kernel.perf_event_max_sample_rate to %d\n",
543 __report_avg, __report_allowed,
544 sysctl_perf_event_sample_rate);
548 static atomic64_t perf_event_id;
550 static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
551 enum event_type_t event_type);
553 static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
554 enum event_type_t event_type,
555 struct task_struct *task);
557 static void update_context_time(struct perf_event_context *ctx);
558 static u64 perf_event_time(struct perf_event *event);
560 void __weak perf_event_print_debug(void) { }
562 extern __weak const char *perf_pmu_name(void)
567 static inline u64 perf_clock(void)
569 return local_clock();
572 static inline u64 perf_event_clock(struct perf_event *event)
574 return event->clock();
577 #ifdef CONFIG_CGROUP_PERF
580 perf_cgroup_match(struct perf_event *event)
582 struct perf_event_context *ctx = event->ctx;
583 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
585 /* @event doesn't care about cgroup */
589 /* wants specific cgroup scope but @cpuctx isn't associated with any */
594 * Cgroup scoping is recursive. An event enabled for a cgroup is
595 * also enabled for all its descendant cgroups. If @cpuctx's
596 * cgroup is a descendant of @event's (the test covers identity
597 * case), it's a match.
599 return cgroup_is_descendant(cpuctx->cgrp->css.cgroup,
600 event->cgrp->css.cgroup);
603 static inline void perf_detach_cgroup(struct perf_event *event)
605 css_put(&event->cgrp->css);
609 static inline int is_cgroup_event(struct perf_event *event)
611 return event->cgrp != NULL;
614 static inline u64 perf_cgroup_event_time(struct perf_event *event)
616 struct perf_cgroup_info *t;
618 t = per_cpu_ptr(event->cgrp->info, event->cpu);
622 static inline void __update_cgrp_time(struct perf_cgroup *cgrp)
624 struct perf_cgroup_info *info;
629 info = this_cpu_ptr(cgrp->info);
631 info->time += now - info->timestamp;
632 info->timestamp = now;
635 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
637 struct perf_cgroup *cgrp_out = cpuctx->cgrp;
639 __update_cgrp_time(cgrp_out);
642 static inline void update_cgrp_time_from_event(struct perf_event *event)
644 struct perf_cgroup *cgrp;
647 * ensure we access cgroup data only when needed and
648 * when we know the cgroup is pinned (css_get)
650 if (!is_cgroup_event(event))
653 cgrp = perf_cgroup_from_task(current, event->ctx);
655 * Do not update time when cgroup is not active
657 if (cgrp == event->cgrp)
658 __update_cgrp_time(event->cgrp);
662 perf_cgroup_set_timestamp(struct task_struct *task,
663 struct perf_event_context *ctx)
665 struct perf_cgroup *cgrp;
666 struct perf_cgroup_info *info;
669 * ctx->lock held by caller
670 * ensure we do not access cgroup data
671 * unless we have the cgroup pinned (css_get)
673 if (!task || !ctx->nr_cgroups)
676 cgrp = perf_cgroup_from_task(task, ctx);
677 info = this_cpu_ptr(cgrp->info);
678 info->timestamp = ctx->timestamp;
681 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
682 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
685 * reschedule events based on the cgroup constraint of task.
687 * mode SWOUT : schedule out everything
688 * mode SWIN : schedule in based on cgroup for next
690 static void perf_cgroup_switch(struct task_struct *task, int mode)
692 struct perf_cpu_context *cpuctx;
697 * disable interrupts to avoid geting nr_cgroup
698 * changes via __perf_event_disable(). Also
701 local_irq_save(flags);
704 * we reschedule only in the presence of cgroup
705 * constrained events.
708 list_for_each_entry_rcu(pmu, &pmus, entry) {
709 cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
710 if (cpuctx->unique_pmu != pmu)
711 continue; /* ensure we process each cpuctx once */
714 * perf_cgroup_events says at least one
715 * context on this CPU has cgroup events.
717 * ctx->nr_cgroups reports the number of cgroup
718 * events for a context.
720 if (cpuctx->ctx.nr_cgroups > 0) {
721 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
722 perf_pmu_disable(cpuctx->ctx.pmu);
724 if (mode & PERF_CGROUP_SWOUT) {
725 cpu_ctx_sched_out(cpuctx, EVENT_ALL);
727 * must not be done before ctxswout due
728 * to event_filter_match() in event_sched_out()
733 if (mode & PERF_CGROUP_SWIN) {
734 WARN_ON_ONCE(cpuctx->cgrp);
736 * set cgrp before ctxsw in to allow
737 * event_filter_match() to not have to pass
739 * we pass the cpuctx->ctx to perf_cgroup_from_task()
740 * because cgorup events are only per-cpu
742 cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx);
743 cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
745 perf_pmu_enable(cpuctx->ctx.pmu);
746 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
750 local_irq_restore(flags);
753 static inline void perf_cgroup_sched_out(struct task_struct *task,
754 struct task_struct *next)
756 struct perf_cgroup *cgrp1;
757 struct perf_cgroup *cgrp2 = NULL;
761 * we come here when we know perf_cgroup_events > 0
762 * we do not need to pass the ctx here because we know
763 * we are holding the rcu lock
765 cgrp1 = perf_cgroup_from_task(task, NULL);
766 cgrp2 = perf_cgroup_from_task(next, NULL);
769 * only schedule out current cgroup events if we know
770 * that we are switching to a different cgroup. Otherwise,
771 * do no touch the cgroup events.
774 perf_cgroup_switch(task, PERF_CGROUP_SWOUT);
779 static inline void perf_cgroup_sched_in(struct task_struct *prev,
780 struct task_struct *task)
782 struct perf_cgroup *cgrp1;
783 struct perf_cgroup *cgrp2 = NULL;
787 * we come here when we know perf_cgroup_events > 0
788 * we do not need to pass the ctx here because we know
789 * we are holding the rcu lock
791 cgrp1 = perf_cgroup_from_task(task, NULL);
792 cgrp2 = perf_cgroup_from_task(prev, NULL);
795 * only need to schedule in cgroup events if we are changing
796 * cgroup during ctxsw. Cgroup events were not scheduled
797 * out of ctxsw out if that was not the case.
800 perf_cgroup_switch(task, PERF_CGROUP_SWIN);
805 static inline int perf_cgroup_connect(int fd, struct perf_event *event,
806 struct perf_event_attr *attr,
807 struct perf_event *group_leader)
809 struct perf_cgroup *cgrp;
810 struct cgroup_subsys_state *css;
811 struct fd f = fdget(fd);
817 css = css_tryget_online_from_dir(f.file->f_path.dentry,
818 &perf_event_cgrp_subsys);
824 cgrp = container_of(css, struct perf_cgroup, css);
828 * all events in a group must monitor
829 * the same cgroup because a task belongs
830 * to only one perf cgroup at a time
832 if (group_leader && group_leader->cgrp != cgrp) {
833 perf_detach_cgroup(event);
842 perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
844 struct perf_cgroup_info *t;
845 t = per_cpu_ptr(event->cgrp->info, event->cpu);
846 event->shadow_ctx_time = now - t->timestamp;
850 perf_cgroup_defer_enabled(struct perf_event *event)
853 * when the current task's perf cgroup does not match
854 * the event's, we need to remember to call the
855 * perf_mark_enable() function the first time a task with
856 * a matching perf cgroup is scheduled in.
858 if (is_cgroup_event(event) && !perf_cgroup_match(event))
859 event->cgrp_defer_enabled = 1;
863 perf_cgroup_mark_enabled(struct perf_event *event,
864 struct perf_event_context *ctx)
866 struct perf_event *sub;
867 u64 tstamp = perf_event_time(event);
869 if (!event->cgrp_defer_enabled)
872 event->cgrp_defer_enabled = 0;
874 event->tstamp_enabled = tstamp - event->total_time_enabled;
875 list_for_each_entry(sub, &event->sibling_list, group_entry) {
876 if (sub->state >= PERF_EVENT_STATE_INACTIVE) {
877 sub->tstamp_enabled = tstamp - sub->total_time_enabled;
878 sub->cgrp_defer_enabled = 0;
884 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
885 * cleared when last cgroup event is removed.
888 list_update_cgroup_event(struct perf_event *event,
889 struct perf_event_context *ctx, bool add)
891 struct perf_cpu_context *cpuctx;
893 if (!is_cgroup_event(event))
896 if (add && ctx->nr_cgroups++)
898 else if (!add && --ctx->nr_cgroups)
901 * Because cgroup events are always per-cpu events,
902 * this will always be called from the right CPU.
904 cpuctx = __get_cpu_context(ctx);
905 cpuctx->cgrp = add ? event->cgrp : NULL;
908 #else /* !CONFIG_CGROUP_PERF */
911 perf_cgroup_match(struct perf_event *event)
916 static inline void perf_detach_cgroup(struct perf_event *event)
919 static inline int is_cgroup_event(struct perf_event *event)
924 static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event)
929 static inline void update_cgrp_time_from_event(struct perf_event *event)
933 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
937 static inline void perf_cgroup_sched_out(struct task_struct *task,
938 struct task_struct *next)
942 static inline void perf_cgroup_sched_in(struct task_struct *prev,
943 struct task_struct *task)
947 static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event,
948 struct perf_event_attr *attr,
949 struct perf_event *group_leader)
955 perf_cgroup_set_timestamp(struct task_struct *task,
956 struct perf_event_context *ctx)
961 perf_cgroup_switch(struct task_struct *task, struct task_struct *next)
966 perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
970 static inline u64 perf_cgroup_event_time(struct perf_event *event)
976 perf_cgroup_defer_enabled(struct perf_event *event)
981 perf_cgroup_mark_enabled(struct perf_event *event,
982 struct perf_event_context *ctx)
987 list_update_cgroup_event(struct perf_event *event,
988 struct perf_event_context *ctx, bool add)
995 * set default to be dependent on timer tick just
998 #define PERF_CPU_HRTIMER (1000 / HZ)
1000 * function must be called with interrupts disbled
1002 static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr)
1004 struct perf_cpu_context *cpuctx;
1007 WARN_ON(!irqs_disabled());
1009 cpuctx = container_of(hr, struct perf_cpu_context, hrtimer);
1010 rotations = perf_rotate_context(cpuctx);
1012 raw_spin_lock(&cpuctx->hrtimer_lock);
1014 hrtimer_forward_now(hr, cpuctx->hrtimer_interval);
1016 cpuctx->hrtimer_active = 0;
1017 raw_spin_unlock(&cpuctx->hrtimer_lock);
1019 return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART;
1022 static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu)
1024 struct hrtimer *timer = &cpuctx->hrtimer;
1025 struct pmu *pmu = cpuctx->ctx.pmu;
1028 /* no multiplexing needed for SW PMU */
1029 if (pmu->task_ctx_nr == perf_sw_context)
1033 * check default is sane, if not set then force to
1034 * default interval (1/tick)
1036 interval = pmu->hrtimer_interval_ms;
1038 interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER;
1040 cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
1042 raw_spin_lock_init(&cpuctx->hrtimer_lock);
1043 hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
1044 timer->function = perf_mux_hrtimer_handler;
1047 static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx)
1049 struct hrtimer *timer = &cpuctx->hrtimer;
1050 struct pmu *pmu = cpuctx->ctx.pmu;
1051 unsigned long flags;
1053 /* not for SW PMU */
1054 if (pmu->task_ctx_nr == perf_sw_context)
1057 raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags);
1058 if (!cpuctx->hrtimer_active) {
1059 cpuctx->hrtimer_active = 1;
1060 hrtimer_forward_now(timer, cpuctx->hrtimer_interval);
1061 hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
1063 raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags);
1068 void perf_pmu_disable(struct pmu *pmu)
1070 int *count = this_cpu_ptr(pmu->pmu_disable_count);
1072 pmu->pmu_disable(pmu);
1075 void perf_pmu_enable(struct pmu *pmu)
1077 int *count = this_cpu_ptr(pmu->pmu_disable_count);
1079 pmu->pmu_enable(pmu);
1082 static DEFINE_PER_CPU(struct list_head, active_ctx_list);
1085 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1086 * perf_event_task_tick() are fully serialized because they're strictly cpu
1087 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1088 * disabled, while perf_event_task_tick is called from IRQ context.
1090 static void perf_event_ctx_activate(struct perf_event_context *ctx)
1092 struct list_head *head = this_cpu_ptr(&active_ctx_list);
1094 WARN_ON(!irqs_disabled());
1096 WARN_ON(!list_empty(&ctx->active_ctx_list));
1098 list_add(&ctx->active_ctx_list, head);
1101 static void perf_event_ctx_deactivate(struct perf_event_context *ctx)
1103 WARN_ON(!irqs_disabled());
1105 WARN_ON(list_empty(&ctx->active_ctx_list));
1107 list_del_init(&ctx->active_ctx_list);
1110 static void get_ctx(struct perf_event_context *ctx)
1112 WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
1115 static void free_ctx(struct rcu_head *head)
1117 struct perf_event_context *ctx;
1119 ctx = container_of(head, struct perf_event_context, rcu_head);
1120 kfree(ctx->task_ctx_data);
1124 static void put_ctx(struct perf_event_context *ctx)
1126 if (atomic_dec_and_test(&ctx->refcount)) {
1127 if (ctx->parent_ctx)
1128 put_ctx(ctx->parent_ctx);
1129 if (ctx->task && ctx->task != TASK_TOMBSTONE)
1130 put_task_struct(ctx->task);
1131 call_rcu(&ctx->rcu_head, free_ctx);
1136 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1137 * perf_pmu_migrate_context() we need some magic.
1139 * Those places that change perf_event::ctx will hold both
1140 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1142 * Lock ordering is by mutex address. There are two other sites where
1143 * perf_event_context::mutex nests and those are:
1145 * - perf_event_exit_task_context() [ child , 0 ]
1146 * perf_event_exit_event()
1147 * put_event() [ parent, 1 ]
1149 * - perf_event_init_context() [ parent, 0 ]
1150 * inherit_task_group()
1153 * perf_event_alloc()
1155 * perf_try_init_event() [ child , 1 ]
1157 * While it appears there is an obvious deadlock here -- the parent and child
1158 * nesting levels are inverted between the two. This is in fact safe because
1159 * life-time rules separate them. That is an exiting task cannot fork, and a
1160 * spawning task cannot (yet) exit.
1162 * But remember that that these are parent<->child context relations, and
1163 * migration does not affect children, therefore these two orderings should not
1166 * The change in perf_event::ctx does not affect children (as claimed above)
1167 * because the sys_perf_event_open() case will install a new event and break
1168 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1169 * concerned with cpuctx and that doesn't have children.
1171 * The places that change perf_event::ctx will issue:
1173 * perf_remove_from_context();
1174 * synchronize_rcu();
1175 * perf_install_in_context();
1177 * to affect the change. The remove_from_context() + synchronize_rcu() should
1178 * quiesce the event, after which we can install it in the new location. This
1179 * means that only external vectors (perf_fops, prctl) can perturb the event
1180 * while in transit. Therefore all such accessors should also acquire
1181 * perf_event_context::mutex to serialize against this.
1183 * However; because event->ctx can change while we're waiting to acquire
1184 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1189 * task_struct::perf_event_mutex
1190 * perf_event_context::mutex
1191 * perf_event::child_mutex;
1192 * perf_event_context::lock
1193 * perf_event::mmap_mutex
1196 static struct perf_event_context *
1197 perf_event_ctx_lock_nested(struct perf_event *event, int nesting)
1199 struct perf_event_context *ctx;
1203 ctx = ACCESS_ONCE(event->ctx);
1204 if (!atomic_inc_not_zero(&ctx->refcount)) {
1210 mutex_lock_nested(&ctx->mutex, nesting);
1211 if (event->ctx != ctx) {
1212 mutex_unlock(&ctx->mutex);
1220 static inline struct perf_event_context *
1221 perf_event_ctx_lock(struct perf_event *event)
1223 return perf_event_ctx_lock_nested(event, 0);
1226 static void perf_event_ctx_unlock(struct perf_event *event,
1227 struct perf_event_context *ctx)
1229 mutex_unlock(&ctx->mutex);
1234 * This must be done under the ctx->lock, such as to serialize against
1235 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1236 * calling scheduler related locks and ctx->lock nests inside those.
1238 static __must_check struct perf_event_context *
1239 unclone_ctx(struct perf_event_context *ctx)
1241 struct perf_event_context *parent_ctx = ctx->parent_ctx;
1243 lockdep_assert_held(&ctx->lock);
1246 ctx->parent_ctx = NULL;
1252 static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
1255 * only top level events have the pid namespace they were created in
1258 event = event->parent;
1260 return task_tgid_nr_ns(p, event->ns);
1263 static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
1266 * only top level events have the pid namespace they were created in
1269 event = event->parent;
1271 return task_pid_nr_ns(p, event->ns);
1275 * If we inherit events we want to return the parent event id
1278 static u64 primary_event_id(struct perf_event *event)
1283 id = event->parent->id;
1289 * Get the perf_event_context for a task and lock it.
1291 * This has to cope with with the fact that until it is locked,
1292 * the context could get moved to another task.
1294 static struct perf_event_context *
1295 perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
1297 struct perf_event_context *ctx;
1301 * One of the few rules of preemptible RCU is that one cannot do
1302 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1303 * part of the read side critical section was irqs-enabled -- see
1304 * rcu_read_unlock_special().
1306 * Since ctx->lock nests under rq->lock we must ensure the entire read
1307 * side critical section has interrupts disabled.
1309 local_irq_save(*flags);
1311 ctx = rcu_dereference(task->perf_event_ctxp[ctxn]);
1314 * If this context is a clone of another, it might
1315 * get swapped for another underneath us by
1316 * perf_event_task_sched_out, though the
1317 * rcu_read_lock() protects us from any context
1318 * getting freed. Lock the context and check if it
1319 * got swapped before we could get the lock, and retry
1320 * if so. If we locked the right context, then it
1321 * can't get swapped on us any more.
1323 raw_spin_lock(&ctx->lock);
1324 if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) {
1325 raw_spin_unlock(&ctx->lock);
1327 local_irq_restore(*flags);
1331 if (ctx->task == TASK_TOMBSTONE ||
1332 !atomic_inc_not_zero(&ctx->refcount)) {
1333 raw_spin_unlock(&ctx->lock);
1336 WARN_ON_ONCE(ctx->task != task);
1341 local_irq_restore(*flags);
1346 * Get the context for a task and increment its pin_count so it
1347 * can't get swapped to another task. This also increments its
1348 * reference count so that the context can't get freed.
1350 static struct perf_event_context *
1351 perf_pin_task_context(struct task_struct *task, int ctxn)
1353 struct perf_event_context *ctx;
1354 unsigned long flags;
1356 ctx = perf_lock_task_context(task, ctxn, &flags);
1359 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1364 static void perf_unpin_context(struct perf_event_context *ctx)
1366 unsigned long flags;
1368 raw_spin_lock_irqsave(&ctx->lock, flags);
1370 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1374 * Update the record of the current time in a context.
1376 static void update_context_time(struct perf_event_context *ctx)
1378 u64 now = perf_clock();
1380 ctx->time += now - ctx->timestamp;
1381 ctx->timestamp = now;
1384 static u64 perf_event_time(struct perf_event *event)
1386 struct perf_event_context *ctx = event->ctx;
1388 if (is_cgroup_event(event))
1389 return perf_cgroup_event_time(event);
1391 return ctx ? ctx->time : 0;
1395 * Update the total_time_enabled and total_time_running fields for a event.
1397 static void update_event_times(struct perf_event *event)
1399 struct perf_event_context *ctx = event->ctx;
1402 lockdep_assert_held(&ctx->lock);
1404 if (event->state < PERF_EVENT_STATE_INACTIVE ||
1405 event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
1409 * in cgroup mode, time_enabled represents
1410 * the time the event was enabled AND active
1411 * tasks were in the monitored cgroup. This is
1412 * independent of the activity of the context as
1413 * there may be a mix of cgroup and non-cgroup events.
1415 * That is why we treat cgroup events differently
1418 if (is_cgroup_event(event))
1419 run_end = perf_cgroup_event_time(event);
1420 else if (ctx->is_active)
1421 run_end = ctx->time;
1423 run_end = event->tstamp_stopped;
1425 event->total_time_enabled = run_end - event->tstamp_enabled;
1427 if (event->state == PERF_EVENT_STATE_INACTIVE)
1428 run_end = event->tstamp_stopped;
1430 run_end = perf_event_time(event);
1432 event->total_time_running = run_end - event->tstamp_running;
1437 * Update total_time_enabled and total_time_running for all events in a group.
1439 static void update_group_times(struct perf_event *leader)
1441 struct perf_event *event;
1443 update_event_times(leader);
1444 list_for_each_entry(event, &leader->sibling_list, group_entry)
1445 update_event_times(event);
1448 static struct list_head *
1449 ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
1451 if (event->attr.pinned)
1452 return &ctx->pinned_groups;
1454 return &ctx->flexible_groups;
1458 * Add a event from the lists for its context.
1459 * Must be called with ctx->mutex and ctx->lock held.
1462 list_add_event(struct perf_event *event, struct perf_event_context *ctx)
1465 lockdep_assert_held(&ctx->lock);
1467 WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
1468 event->attach_state |= PERF_ATTACH_CONTEXT;
1471 * If we're a stand alone event or group leader, we go to the context
1472 * list, group events are kept attached to the group so that
1473 * perf_group_detach can, at all times, locate all siblings.
1475 if (event->group_leader == event) {
1476 struct list_head *list;
1478 if (is_software_event(event))
1479 event->group_flags |= PERF_GROUP_SOFTWARE;
1481 list = ctx_group_list(event, ctx);
1482 list_add_tail(&event->group_entry, list);
1485 list_update_cgroup_event(event, ctx, true);
1487 list_add_rcu(&event->event_entry, &ctx->event_list);
1489 if (event->attr.inherit_stat)
1496 * Initialize event state based on the perf_event_attr::disabled.
1498 static inline void perf_event__state_init(struct perf_event *event)
1500 event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF :
1501 PERF_EVENT_STATE_INACTIVE;
1504 static void __perf_event_read_size(struct perf_event *event, int nr_siblings)
1506 int entry = sizeof(u64); /* value */
1510 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
1511 size += sizeof(u64);
1513 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
1514 size += sizeof(u64);
1516 if (event->attr.read_format & PERF_FORMAT_ID)
1517 entry += sizeof(u64);
1519 if (event->attr.read_format & PERF_FORMAT_GROUP) {
1521 size += sizeof(u64);
1525 event->read_size = size;
1528 static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
1530 struct perf_sample_data *data;
1533 if (sample_type & PERF_SAMPLE_IP)
1534 size += sizeof(data->ip);
1536 if (sample_type & PERF_SAMPLE_ADDR)
1537 size += sizeof(data->addr);
1539 if (sample_type & PERF_SAMPLE_PERIOD)
1540 size += sizeof(data->period);
1542 if (sample_type & PERF_SAMPLE_WEIGHT)
1543 size += sizeof(data->weight);
1545 if (sample_type & PERF_SAMPLE_READ)
1546 size += event->read_size;
1548 if (sample_type & PERF_SAMPLE_DATA_SRC)
1549 size += sizeof(data->data_src.val);
1551 if (sample_type & PERF_SAMPLE_TRANSACTION)
1552 size += sizeof(data->txn);
1554 event->header_size = size;
1558 * Called at perf_event creation and when events are attached/detached from a
1561 static void perf_event__header_size(struct perf_event *event)
1563 __perf_event_read_size(event,
1564 event->group_leader->nr_siblings);
1565 __perf_event_header_size(event, event->attr.sample_type);
1568 static void perf_event__id_header_size(struct perf_event *event)
1570 struct perf_sample_data *data;
1571 u64 sample_type = event->attr.sample_type;
1574 if (sample_type & PERF_SAMPLE_TID)
1575 size += sizeof(data->tid_entry);
1577 if (sample_type & PERF_SAMPLE_TIME)
1578 size += sizeof(data->time);
1580 if (sample_type & PERF_SAMPLE_IDENTIFIER)
1581 size += sizeof(data->id);
1583 if (sample_type & PERF_SAMPLE_ID)
1584 size += sizeof(data->id);
1586 if (sample_type & PERF_SAMPLE_STREAM_ID)
1587 size += sizeof(data->stream_id);
1589 if (sample_type & PERF_SAMPLE_CPU)
1590 size += sizeof(data->cpu_entry);
1592 event->id_header_size = size;
1595 static bool perf_event_validate_size(struct perf_event *event)
1598 * The values computed here will be over-written when we actually
1601 __perf_event_read_size(event, event->group_leader->nr_siblings + 1);
1602 __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ);
1603 perf_event__id_header_size(event);
1606 * Sum the lot; should not exceed the 64k limit we have on records.
1607 * Conservative limit to allow for callchains and other variable fields.
1609 if (event->read_size + event->header_size +
1610 event->id_header_size + sizeof(struct perf_event_header) >= 16*1024)
1616 static void perf_group_attach(struct perf_event *event)
1618 struct perf_event *group_leader = event->group_leader, *pos;
1621 * We can have double attach due to group movement in perf_event_open.
1623 if (event->attach_state & PERF_ATTACH_GROUP)
1626 event->attach_state |= PERF_ATTACH_GROUP;
1628 if (group_leader == event)
1631 WARN_ON_ONCE(group_leader->ctx != event->ctx);
1633 if (group_leader->group_flags & PERF_GROUP_SOFTWARE &&
1634 !is_software_event(event))
1635 group_leader->group_flags &= ~PERF_GROUP_SOFTWARE;
1637 list_add_tail(&event->group_entry, &group_leader->sibling_list);
1638 group_leader->nr_siblings++;
1640 perf_event__header_size(group_leader);
1642 list_for_each_entry(pos, &group_leader->sibling_list, group_entry)
1643 perf_event__header_size(pos);
1647 * Remove a event from the lists for its context.
1648 * Must be called with ctx->mutex and ctx->lock held.
1651 list_del_event(struct perf_event *event, struct perf_event_context *ctx)
1653 WARN_ON_ONCE(event->ctx != ctx);
1654 lockdep_assert_held(&ctx->lock);
1657 * We can have double detach due to exit/hot-unplug + close.
1659 if (!(event->attach_state & PERF_ATTACH_CONTEXT))
1662 event->attach_state &= ~PERF_ATTACH_CONTEXT;
1664 list_update_cgroup_event(event, ctx, false);
1667 if (event->attr.inherit_stat)
1670 list_del_rcu(&event->event_entry);
1672 if (event->group_leader == event)
1673 list_del_init(&event->group_entry);
1675 update_group_times(event);
1678 * If event was in error state, then keep it
1679 * that way, otherwise bogus counts will be
1680 * returned on read(). The only way to get out
1681 * of error state is by explicit re-enabling
1684 if (event->state > PERF_EVENT_STATE_OFF)
1685 event->state = PERF_EVENT_STATE_OFF;
1690 static void perf_group_detach(struct perf_event *event)
1692 struct perf_event *sibling, *tmp;
1693 struct list_head *list = NULL;
1696 * We can have double detach due to exit/hot-unplug + close.
1698 if (!(event->attach_state & PERF_ATTACH_GROUP))
1701 event->attach_state &= ~PERF_ATTACH_GROUP;
1704 * If this is a sibling, remove it from its group.
1706 if (event->group_leader != event) {
1707 list_del_init(&event->group_entry);
1708 event->group_leader->nr_siblings--;
1712 if (!list_empty(&event->group_entry))
1713 list = &event->group_entry;
1716 * If this was a group event with sibling events then
1717 * upgrade the siblings to singleton events by adding them
1718 * to whatever list we are on.
1720 list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
1722 list_move_tail(&sibling->group_entry, list);
1723 sibling->group_leader = sibling;
1725 /* Inherit group flags from the previous leader */
1726 sibling->group_flags = event->group_flags;
1728 WARN_ON_ONCE(sibling->ctx != event->ctx);
1732 perf_event__header_size(event->group_leader);
1734 list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry)
1735 perf_event__header_size(tmp);
1738 static bool is_orphaned_event(struct perf_event *event)
1740 return event->state == PERF_EVENT_STATE_DEAD;
1743 static inline int __pmu_filter_match(struct perf_event *event)
1745 struct pmu *pmu = event->pmu;
1746 return pmu->filter_match ? pmu->filter_match(event) : 1;
1750 * Check whether we should attempt to schedule an event group based on
1751 * PMU-specific filtering. An event group can consist of HW and SW events,
1752 * potentially with a SW leader, so we must check all the filters, to
1753 * determine whether a group is schedulable:
1755 static inline int pmu_filter_match(struct perf_event *event)
1757 struct perf_event *child;
1759 if (!__pmu_filter_match(event))
1762 list_for_each_entry(child, &event->sibling_list, group_entry) {
1763 if (!__pmu_filter_match(child))
1771 event_filter_match(struct perf_event *event)
1773 return (event->cpu == -1 || event->cpu == smp_processor_id()) &&
1774 perf_cgroup_match(event) && pmu_filter_match(event);
1778 event_sched_out(struct perf_event *event,
1779 struct perf_cpu_context *cpuctx,
1780 struct perf_event_context *ctx)
1782 u64 tstamp = perf_event_time(event);
1785 WARN_ON_ONCE(event->ctx != ctx);
1786 lockdep_assert_held(&ctx->lock);
1789 * An event which could not be activated because of
1790 * filter mismatch still needs to have its timings
1791 * maintained, otherwise bogus information is return
1792 * via read() for time_enabled, time_running:
1794 if (event->state == PERF_EVENT_STATE_INACTIVE &&
1795 !event_filter_match(event)) {
1796 delta = tstamp - event->tstamp_stopped;
1797 event->tstamp_running += delta;
1798 event->tstamp_stopped = tstamp;
1801 if (event->state != PERF_EVENT_STATE_ACTIVE)
1804 perf_pmu_disable(event->pmu);
1806 event->tstamp_stopped = tstamp;
1807 event->pmu->del(event, 0);
1809 event->state = PERF_EVENT_STATE_INACTIVE;
1810 if (event->pending_disable) {
1811 event->pending_disable = 0;
1812 event->state = PERF_EVENT_STATE_OFF;
1815 if (!is_software_event(event))
1816 cpuctx->active_oncpu--;
1817 if (!--ctx->nr_active)
1818 perf_event_ctx_deactivate(ctx);
1819 if (event->attr.freq && event->attr.sample_freq)
1821 if (event->attr.exclusive || !cpuctx->active_oncpu)
1822 cpuctx->exclusive = 0;
1824 perf_pmu_enable(event->pmu);
1828 group_sched_out(struct perf_event *group_event,
1829 struct perf_cpu_context *cpuctx,
1830 struct perf_event_context *ctx)
1832 struct perf_event *event;
1833 int state = group_event->state;
1835 perf_pmu_disable(ctx->pmu);
1837 event_sched_out(group_event, cpuctx, ctx);
1840 * Schedule out siblings (if any):
1842 list_for_each_entry(event, &group_event->sibling_list, group_entry)
1843 event_sched_out(event, cpuctx, ctx);
1845 perf_pmu_enable(ctx->pmu);
1847 if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive)
1848 cpuctx->exclusive = 0;
1851 #define DETACH_GROUP 0x01UL
1854 * Cross CPU call to remove a performance event
1856 * We disable the event on the hardware level first. After that we
1857 * remove it from the context list.
1860 __perf_remove_from_context(struct perf_event *event,
1861 struct perf_cpu_context *cpuctx,
1862 struct perf_event_context *ctx,
1865 unsigned long flags = (unsigned long)info;
1867 event_sched_out(event, cpuctx, ctx);
1868 if (flags & DETACH_GROUP)
1869 perf_group_detach(event);
1870 list_del_event(event, ctx);
1872 if (!ctx->nr_events && ctx->is_active) {
1875 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
1876 cpuctx->task_ctx = NULL;
1882 * Remove the event from a task's (or a CPU's) list of events.
1884 * If event->ctx is a cloned context, callers must make sure that
1885 * every task struct that event->ctx->task could possibly point to
1886 * remains valid. This is OK when called from perf_release since
1887 * that only calls us on the top-level context, which can't be a clone.
1888 * When called from perf_event_exit_task, it's OK because the
1889 * context has been detached from its task.
1891 static void perf_remove_from_context(struct perf_event *event, unsigned long flags)
1893 lockdep_assert_held(&event->ctx->mutex);
1895 event_function_call(event, __perf_remove_from_context, (void *)flags);
1899 * Cross CPU call to disable a performance event
1901 static void __perf_event_disable(struct perf_event *event,
1902 struct perf_cpu_context *cpuctx,
1903 struct perf_event_context *ctx,
1906 if (event->state < PERF_EVENT_STATE_INACTIVE)
1909 update_context_time(ctx);
1910 update_cgrp_time_from_event(event);
1911 update_group_times(event);
1912 if (event == event->group_leader)
1913 group_sched_out(event, cpuctx, ctx);
1915 event_sched_out(event, cpuctx, ctx);
1916 event->state = PERF_EVENT_STATE_OFF;
1922 * If event->ctx is a cloned context, callers must make sure that
1923 * every task struct that event->ctx->task could possibly point to
1924 * remains valid. This condition is satisifed when called through
1925 * perf_event_for_each_child or perf_event_for_each because they
1926 * hold the top-level event's child_mutex, so any descendant that
1927 * goes to exit will block in perf_event_exit_event().
1929 * When called from perf_pending_event it's OK because event->ctx
1930 * is the current context on this CPU and preemption is disabled,
1931 * hence we can't get into perf_event_task_sched_out for this context.
1933 static void _perf_event_disable(struct perf_event *event)
1935 struct perf_event_context *ctx = event->ctx;
1937 raw_spin_lock_irq(&ctx->lock);
1938 if (event->state <= PERF_EVENT_STATE_OFF) {
1939 raw_spin_unlock_irq(&ctx->lock);
1942 raw_spin_unlock_irq(&ctx->lock);
1944 event_function_call(event, __perf_event_disable, NULL);
1947 void perf_event_disable_local(struct perf_event *event)
1949 event_function_local(event, __perf_event_disable, NULL);
1953 * Strictly speaking kernel users cannot create groups and therefore this
1954 * interface does not need the perf_event_ctx_lock() magic.
1956 void perf_event_disable(struct perf_event *event)
1958 struct perf_event_context *ctx;
1960 ctx = perf_event_ctx_lock(event);
1961 _perf_event_disable(event);
1962 perf_event_ctx_unlock(event, ctx);
1964 EXPORT_SYMBOL_GPL(perf_event_disable);
1966 static void perf_set_shadow_time(struct perf_event *event,
1967 struct perf_event_context *ctx,
1971 * use the correct time source for the time snapshot
1973 * We could get by without this by leveraging the
1974 * fact that to get to this function, the caller
1975 * has most likely already called update_context_time()
1976 * and update_cgrp_time_xx() and thus both timestamp
1977 * are identical (or very close). Given that tstamp is,
1978 * already adjusted for cgroup, we could say that:
1979 * tstamp - ctx->timestamp
1981 * tstamp - cgrp->timestamp.
1983 * Then, in perf_output_read(), the calculation would
1984 * work with no changes because:
1985 * - event is guaranteed scheduled in
1986 * - no scheduled out in between
1987 * - thus the timestamp would be the same
1989 * But this is a bit hairy.
1991 * So instead, we have an explicit cgroup call to remain
1992 * within the time time source all along. We believe it
1993 * is cleaner and simpler to understand.
1995 if (is_cgroup_event(event))
1996 perf_cgroup_set_shadow_time(event, tstamp);
1998 event->shadow_ctx_time = tstamp - ctx->timestamp;
2001 #define MAX_INTERRUPTS (~0ULL)
2003 static void perf_log_throttle(struct perf_event *event, int enable);
2004 static void perf_log_itrace_start(struct perf_event *event);
2007 event_sched_in(struct perf_event *event,
2008 struct perf_cpu_context *cpuctx,
2009 struct perf_event_context *ctx)
2011 u64 tstamp = perf_event_time(event);
2014 lockdep_assert_held(&ctx->lock);
2016 if (event->state <= PERF_EVENT_STATE_OFF)
2019 WRITE_ONCE(event->oncpu, smp_processor_id());
2021 * Order event::oncpu write to happen before the ACTIVE state
2025 WRITE_ONCE(event->state, PERF_EVENT_STATE_ACTIVE);
2028 * Unthrottle events, since we scheduled we might have missed several
2029 * ticks already, also for a heavily scheduling task there is little
2030 * guarantee it'll get a tick in a timely manner.
2032 if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
2033 perf_log_throttle(event, 1);
2034 event->hw.interrupts = 0;
2038 * The new state must be visible before we turn it on in the hardware:
2042 perf_pmu_disable(event->pmu);
2044 perf_set_shadow_time(event, ctx, tstamp);
2046 perf_log_itrace_start(event);
2048 if (event->pmu->add(event, PERF_EF_START)) {
2049 event->state = PERF_EVENT_STATE_INACTIVE;
2055 event->tstamp_running += tstamp - event->tstamp_stopped;
2057 if (!is_software_event(event))
2058 cpuctx->active_oncpu++;
2059 if (!ctx->nr_active++)
2060 perf_event_ctx_activate(ctx);
2061 if (event->attr.freq && event->attr.sample_freq)
2064 if (event->attr.exclusive)
2065 cpuctx->exclusive = 1;
2068 perf_pmu_enable(event->pmu);
2074 group_sched_in(struct perf_event *group_event,
2075 struct perf_cpu_context *cpuctx,
2076 struct perf_event_context *ctx)
2078 struct perf_event *event, *partial_group = NULL;
2079 struct pmu *pmu = ctx->pmu;
2080 u64 now = ctx->time;
2081 bool simulate = false;
2083 if (group_event->state == PERF_EVENT_STATE_OFF)
2086 pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
2088 if (event_sched_in(group_event, cpuctx, ctx)) {
2089 pmu->cancel_txn(pmu);
2090 perf_mux_hrtimer_restart(cpuctx);
2095 * Schedule in siblings as one group (if any):
2097 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
2098 if (event_sched_in(event, cpuctx, ctx)) {
2099 partial_group = event;
2104 if (!pmu->commit_txn(pmu))
2109 * Groups can be scheduled in as one unit only, so undo any
2110 * partial group before returning:
2111 * The events up to the failed event are scheduled out normally,
2112 * tstamp_stopped will be updated.
2114 * The failed events and the remaining siblings need to have
2115 * their timings updated as if they had gone thru event_sched_in()
2116 * and event_sched_out(). This is required to get consistent timings
2117 * across the group. This also takes care of the case where the group
2118 * could never be scheduled by ensuring tstamp_stopped is set to mark
2119 * the time the event was actually stopped, such that time delta
2120 * calculation in update_event_times() is correct.
2122 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
2123 if (event == partial_group)
2127 event->tstamp_running += now - event->tstamp_stopped;
2128 event->tstamp_stopped = now;
2130 event_sched_out(event, cpuctx, ctx);
2133 event_sched_out(group_event, cpuctx, ctx);
2135 pmu->cancel_txn(pmu);
2137 perf_mux_hrtimer_restart(cpuctx);
2143 * Work out whether we can put this event group on the CPU now.
2145 static int group_can_go_on(struct perf_event *event,
2146 struct perf_cpu_context *cpuctx,
2150 * Groups consisting entirely of software events can always go on.
2152 if (event->group_flags & PERF_GROUP_SOFTWARE)
2155 * If an exclusive group is already on, no other hardware
2158 if (cpuctx->exclusive)
2161 * If this group is exclusive and there are already
2162 * events on the CPU, it can't go on.
2164 if (event->attr.exclusive && cpuctx->active_oncpu)
2167 * Otherwise, try to add it if all previous groups were able
2173 static void add_event_to_ctx(struct perf_event *event,
2174 struct perf_event_context *ctx)
2176 u64 tstamp = perf_event_time(event);
2178 list_add_event(event, ctx);
2179 perf_group_attach(event);
2180 event->tstamp_enabled = tstamp;
2181 event->tstamp_running = tstamp;
2182 event->tstamp_stopped = tstamp;
2185 static void ctx_sched_out(struct perf_event_context *ctx,
2186 struct perf_cpu_context *cpuctx,
2187 enum event_type_t event_type);
2189 ctx_sched_in(struct perf_event_context *ctx,
2190 struct perf_cpu_context *cpuctx,
2191 enum event_type_t event_type,
2192 struct task_struct *task);
2194 static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
2195 struct perf_event_context *ctx)
2197 if (!cpuctx->task_ctx)
2200 if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
2203 ctx_sched_out(ctx, cpuctx, EVENT_ALL);
2206 static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
2207 struct perf_event_context *ctx,
2208 struct task_struct *task)
2210 cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task);
2212 ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task);
2213 cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task);
2215 ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
2218 static void ctx_resched(struct perf_cpu_context *cpuctx,
2219 struct perf_event_context *task_ctx)
2221 perf_pmu_disable(cpuctx->ctx.pmu);
2223 task_ctx_sched_out(cpuctx, task_ctx);
2224 cpu_ctx_sched_out(cpuctx, EVENT_ALL);
2225 perf_event_sched_in(cpuctx, task_ctx, current);
2226 perf_pmu_enable(cpuctx->ctx.pmu);
2230 * Cross CPU call to install and enable a performance event
2232 * Very similar to remote_function() + event_function() but cannot assume that
2233 * things like ctx->is_active and cpuctx->task_ctx are set.
2235 static int __perf_install_in_context(void *info)
2237 struct perf_event *event = info;
2238 struct perf_event_context *ctx = event->ctx;
2239 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
2240 struct perf_event_context *task_ctx = cpuctx->task_ctx;
2241 bool activate = true;
2244 raw_spin_lock(&cpuctx->ctx.lock);
2246 raw_spin_lock(&ctx->lock);
2249 /* If we're on the wrong CPU, try again */
2250 if (task_cpu(ctx->task) != smp_processor_id()) {
2256 * If we're on the right CPU, see if the task we target is
2257 * current, if not we don't have to activate the ctx, a future
2258 * context switch will do that for us.
2260 if (ctx->task != current)
2263 WARN_ON_ONCE(cpuctx->task_ctx && cpuctx->task_ctx != ctx);
2265 } else if (task_ctx) {
2266 raw_spin_lock(&task_ctx->lock);
2270 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
2271 add_event_to_ctx(event, ctx);
2272 ctx_resched(cpuctx, task_ctx);
2274 add_event_to_ctx(event, ctx);
2278 perf_ctx_unlock(cpuctx, task_ctx);
2284 * Attach a performance event to a context.
2286 * Very similar to event_function_call, see comment there.
2289 perf_install_in_context(struct perf_event_context *ctx,
2290 struct perf_event *event,
2293 struct task_struct *task = READ_ONCE(ctx->task);
2295 lockdep_assert_held(&ctx->mutex);
2297 if (event->cpu != -1)
2301 * Ensures that if we can observe event->ctx, both the event and ctx
2302 * will be 'complete'. See perf_iterate_sb_cpu().
2304 smp_store_release(&event->ctx, ctx);
2307 cpu_function_call(cpu, __perf_install_in_context, event);
2312 * Should not happen, we validate the ctx is still alive before calling.
2314 if (WARN_ON_ONCE(task == TASK_TOMBSTONE))
2318 * Installing events is tricky because we cannot rely on ctx->is_active
2319 * to be set in case this is the nr_events 0 -> 1 transition.
2323 * Cannot use task_function_call() because we need to run on the task's
2324 * CPU regardless of whether its current or not.
2326 if (!cpu_function_call(task_cpu(task), __perf_install_in_context, event))
2329 raw_spin_lock_irq(&ctx->lock);
2331 if (WARN_ON_ONCE(task == TASK_TOMBSTONE)) {
2333 * Cannot happen because we already checked above (which also
2334 * cannot happen), and we hold ctx->mutex, which serializes us
2335 * against perf_event_exit_task_context().
2337 raw_spin_unlock_irq(&ctx->lock);
2340 raw_spin_unlock_irq(&ctx->lock);
2342 * Since !ctx->is_active doesn't mean anything, we must IPI
2349 * Put a event into inactive state and update time fields.
2350 * Enabling the leader of a group effectively enables all
2351 * the group members that aren't explicitly disabled, so we
2352 * have to update their ->tstamp_enabled also.
2353 * Note: this works for group members as well as group leaders
2354 * since the non-leader members' sibling_lists will be empty.
2356 static void __perf_event_mark_enabled(struct perf_event *event)
2358 struct perf_event *sub;
2359 u64 tstamp = perf_event_time(event);
2361 event->state = PERF_EVENT_STATE_INACTIVE;
2362 event->tstamp_enabled = tstamp - event->total_time_enabled;
2363 list_for_each_entry(sub, &event->sibling_list, group_entry) {
2364 if (sub->state >= PERF_EVENT_STATE_INACTIVE)
2365 sub->tstamp_enabled = tstamp - sub->total_time_enabled;
2370 * Cross CPU call to enable a performance event
2372 static void __perf_event_enable(struct perf_event *event,
2373 struct perf_cpu_context *cpuctx,
2374 struct perf_event_context *ctx,
2377 struct perf_event *leader = event->group_leader;
2378 struct perf_event_context *task_ctx;
2380 if (event->state >= PERF_EVENT_STATE_INACTIVE ||
2381 event->state <= PERF_EVENT_STATE_ERROR)
2385 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
2387 __perf_event_mark_enabled(event);
2389 if (!ctx->is_active)
2392 if (!event_filter_match(event)) {
2393 if (is_cgroup_event(event))
2394 perf_cgroup_defer_enabled(event);
2395 ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
2400 * If the event is in a group and isn't the group leader,
2401 * then don't put it on unless the group is on.
2403 if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE) {
2404 ctx_sched_in(ctx, cpuctx, EVENT_TIME, current);
2408 task_ctx = cpuctx->task_ctx;
2410 WARN_ON_ONCE(task_ctx != ctx);
2412 ctx_resched(cpuctx, task_ctx);
2418 * If event->ctx is a cloned context, callers must make sure that
2419 * every task struct that event->ctx->task could possibly point to
2420 * remains valid. This condition is satisfied when called through
2421 * perf_event_for_each_child or perf_event_for_each as described
2422 * for perf_event_disable.
2424 static void _perf_event_enable(struct perf_event *event)
2426 struct perf_event_context *ctx = event->ctx;
2428 raw_spin_lock_irq(&ctx->lock);
2429 if (event->state >= PERF_EVENT_STATE_INACTIVE ||
2430 event->state < PERF_EVENT_STATE_ERROR) {
2431 raw_spin_unlock_irq(&ctx->lock);
2436 * If the event is in error state, clear that first.
2438 * That way, if we see the event in error state below, we know that it
2439 * has gone back into error state, as distinct from the task having
2440 * been scheduled away before the cross-call arrived.
2442 if (event->state == PERF_EVENT_STATE_ERROR)
2443 event->state = PERF_EVENT_STATE_OFF;
2444 raw_spin_unlock_irq(&ctx->lock);
2446 event_function_call(event, __perf_event_enable, NULL);
2450 * See perf_event_disable();
2452 void perf_event_enable(struct perf_event *event)
2454 struct perf_event_context *ctx;
2456 ctx = perf_event_ctx_lock(event);
2457 _perf_event_enable(event);
2458 perf_event_ctx_unlock(event, ctx);
2460 EXPORT_SYMBOL_GPL(perf_event_enable);
2462 struct stop_event_data {
2463 struct perf_event *event;
2464 unsigned int restart;
2467 static int __perf_event_stop(void *info)
2469 struct stop_event_data *sd = info;
2470 struct perf_event *event = sd->event;
2472 /* if it's already INACTIVE, do nothing */
2473 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
2476 /* matches smp_wmb() in event_sched_in() */
2480 * There is a window with interrupts enabled before we get here,
2481 * so we need to check again lest we try to stop another CPU's event.
2483 if (READ_ONCE(event->oncpu) != smp_processor_id())
2486 event->pmu->stop(event, PERF_EF_UPDATE);
2489 * May race with the actual stop (through perf_pmu_output_stop()),
2490 * but it is only used for events with AUX ring buffer, and such
2491 * events will refuse to restart because of rb::aux_mmap_count==0,
2492 * see comments in perf_aux_output_begin().
2494 * Since this is happening on a event-local CPU, no trace is lost
2498 event->pmu->start(event, PERF_EF_START);
2503 static int perf_event_restart(struct perf_event *event)
2505 struct stop_event_data sd = {
2512 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
2515 /* matches smp_wmb() in event_sched_in() */
2519 * We only want to restart ACTIVE events, so if the event goes
2520 * inactive here (event->oncpu==-1), there's nothing more to do;
2521 * fall through with ret==-ENXIO.
2523 ret = cpu_function_call(READ_ONCE(event->oncpu),
2524 __perf_event_stop, &sd);
2525 } while (ret == -EAGAIN);
2531 * In order to contain the amount of racy and tricky in the address filter
2532 * configuration management, it is a two part process:
2534 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2535 * we update the addresses of corresponding vmas in
2536 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2537 * (p2) when an event is scheduled in (pmu::add), it calls
2538 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2539 * if the generation has changed since the previous call.
2541 * If (p1) happens while the event is active, we restart it to force (p2).
2543 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2544 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2546 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2547 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2549 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2552 void perf_event_addr_filters_sync(struct perf_event *event)
2554 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
2556 if (!has_addr_filter(event))
2559 raw_spin_lock(&ifh->lock);
2560 if (event->addr_filters_gen != event->hw.addr_filters_gen) {
2561 event->pmu->addr_filters_sync(event);
2562 event->hw.addr_filters_gen = event->addr_filters_gen;
2564 raw_spin_unlock(&ifh->lock);
2566 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync);
2568 static int _perf_event_refresh(struct perf_event *event, int refresh)
2571 * not supported on inherited events
2573 if (event->attr.inherit || !is_sampling_event(event))
2576 atomic_add(refresh, &event->event_limit);
2577 _perf_event_enable(event);
2583 * See perf_event_disable()
2585 int perf_event_refresh(struct perf_event *event, int refresh)
2587 struct perf_event_context *ctx;
2590 ctx = perf_event_ctx_lock(event);
2591 ret = _perf_event_refresh(event, refresh);
2592 perf_event_ctx_unlock(event, ctx);
2596 EXPORT_SYMBOL_GPL(perf_event_refresh);
2598 static void ctx_sched_out(struct perf_event_context *ctx,
2599 struct perf_cpu_context *cpuctx,
2600 enum event_type_t event_type)
2602 int is_active = ctx->is_active;
2603 struct perf_event *event;
2605 lockdep_assert_held(&ctx->lock);
2607 if (likely(!ctx->nr_events)) {
2609 * See __perf_remove_from_context().
2611 WARN_ON_ONCE(ctx->is_active);
2613 WARN_ON_ONCE(cpuctx->task_ctx);
2617 ctx->is_active &= ~event_type;
2618 if (!(ctx->is_active & EVENT_ALL))
2622 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
2623 if (!ctx->is_active)
2624 cpuctx->task_ctx = NULL;
2628 * Always update time if it was set; not only when it changes.
2629 * Otherwise we can 'forget' to update time for any but the last
2630 * context we sched out. For example:
2632 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2633 * ctx_sched_out(.event_type = EVENT_PINNED)
2635 * would only update time for the pinned events.
2637 if (is_active & EVENT_TIME) {
2638 /* update (and stop) ctx time */
2639 update_context_time(ctx);
2640 update_cgrp_time_from_cpuctx(cpuctx);
2643 is_active ^= ctx->is_active; /* changed bits */
2645 if (!ctx->nr_active || !(is_active & EVENT_ALL))
2648 perf_pmu_disable(ctx->pmu);
2649 if (is_active & EVENT_PINNED) {
2650 list_for_each_entry(event, &ctx->pinned_groups, group_entry)
2651 group_sched_out(event, cpuctx, ctx);
2654 if (is_active & EVENT_FLEXIBLE) {
2655 list_for_each_entry(event, &ctx->flexible_groups, group_entry)
2656 group_sched_out(event, cpuctx, ctx);
2658 perf_pmu_enable(ctx->pmu);
2662 * Test whether two contexts are equivalent, i.e. whether they have both been
2663 * cloned from the same version of the same context.
2665 * Equivalence is measured using a generation number in the context that is
2666 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2667 * and list_del_event().
2669 static int context_equiv(struct perf_event_context *ctx1,
2670 struct perf_event_context *ctx2)
2672 lockdep_assert_held(&ctx1->lock);
2673 lockdep_assert_held(&ctx2->lock);
2675 /* Pinning disables the swap optimization */
2676 if (ctx1->pin_count || ctx2->pin_count)
2679 /* If ctx1 is the parent of ctx2 */
2680 if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen)
2683 /* If ctx2 is the parent of ctx1 */
2684 if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation)
2688 * If ctx1 and ctx2 have the same parent; we flatten the parent
2689 * hierarchy, see perf_event_init_context().
2691 if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx &&
2692 ctx1->parent_gen == ctx2->parent_gen)
2699 static void __perf_event_sync_stat(struct perf_event *event,
2700 struct perf_event *next_event)
2704 if (!event->attr.inherit_stat)
2708 * Update the event value, we cannot use perf_event_read()
2709 * because we're in the middle of a context switch and have IRQs
2710 * disabled, which upsets smp_call_function_single(), however
2711 * we know the event must be on the current CPU, therefore we
2712 * don't need to use it.
2714 switch (event->state) {
2715 case PERF_EVENT_STATE_ACTIVE:
2716 event->pmu->read(event);
2719 case PERF_EVENT_STATE_INACTIVE:
2720 update_event_times(event);
2728 * In order to keep per-task stats reliable we need to flip the event
2729 * values when we flip the contexts.
2731 value = local64_read(&next_event->count);
2732 value = local64_xchg(&event->count, value);
2733 local64_set(&next_event->count, value);
2735 swap(event->total_time_enabled, next_event->total_time_enabled);
2736 swap(event->total_time_running, next_event->total_time_running);
2739 * Since we swizzled the values, update the user visible data too.
2741 perf_event_update_userpage(event);
2742 perf_event_update_userpage(next_event);
2745 static void perf_event_sync_stat(struct perf_event_context *ctx,
2746 struct perf_event_context *next_ctx)
2748 struct perf_event *event, *next_event;
2753 update_context_time(ctx);
2755 event = list_first_entry(&ctx->event_list,
2756 struct perf_event, event_entry);
2758 next_event = list_first_entry(&next_ctx->event_list,
2759 struct perf_event, event_entry);
2761 while (&event->event_entry != &ctx->event_list &&
2762 &next_event->event_entry != &next_ctx->event_list) {
2764 __perf_event_sync_stat(event, next_event);
2766 event = list_next_entry(event, event_entry);
2767 next_event = list_next_entry(next_event, event_entry);
2771 static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
2772 struct task_struct *next)
2774 struct perf_event_context *ctx = task->perf_event_ctxp[ctxn];
2775 struct perf_event_context *next_ctx;
2776 struct perf_event_context *parent, *next_parent;
2777 struct perf_cpu_context *cpuctx;
2783 cpuctx = __get_cpu_context(ctx);
2784 if (!cpuctx->task_ctx)
2788 next_ctx = next->perf_event_ctxp[ctxn];
2792 parent = rcu_dereference(ctx->parent_ctx);
2793 next_parent = rcu_dereference(next_ctx->parent_ctx);
2795 /* If neither context have a parent context; they cannot be clones. */
2796 if (!parent && !next_parent)
2799 if (next_parent == ctx || next_ctx == parent || next_parent == parent) {
2801 * Looks like the two contexts are clones, so we might be
2802 * able to optimize the context switch. We lock both
2803 * contexts and check that they are clones under the
2804 * lock (including re-checking that neither has been
2805 * uncloned in the meantime). It doesn't matter which
2806 * order we take the locks because no other cpu could
2807 * be trying to lock both of these tasks.
2809 raw_spin_lock(&ctx->lock);
2810 raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
2811 if (context_equiv(ctx, next_ctx)) {
2812 WRITE_ONCE(ctx->task, next);
2813 WRITE_ONCE(next_ctx->task, task);
2815 swap(ctx->task_ctx_data, next_ctx->task_ctx_data);
2818 * RCU_INIT_POINTER here is safe because we've not
2819 * modified the ctx and the above modification of
2820 * ctx->task and ctx->task_ctx_data are immaterial
2821 * since those values are always verified under
2822 * ctx->lock which we're now holding.
2824 RCU_INIT_POINTER(task->perf_event_ctxp[ctxn], next_ctx);
2825 RCU_INIT_POINTER(next->perf_event_ctxp[ctxn], ctx);
2829 perf_event_sync_stat(ctx, next_ctx);
2831 raw_spin_unlock(&next_ctx->lock);
2832 raw_spin_unlock(&ctx->lock);
2838 raw_spin_lock(&ctx->lock);
2839 task_ctx_sched_out(cpuctx, ctx);
2840 raw_spin_unlock(&ctx->lock);
2844 static DEFINE_PER_CPU(struct list_head, sched_cb_list);
2846 void perf_sched_cb_dec(struct pmu *pmu)
2848 struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
2850 this_cpu_dec(perf_sched_cb_usages);
2852 if (!--cpuctx->sched_cb_usage)
2853 list_del(&cpuctx->sched_cb_entry);
2857 void perf_sched_cb_inc(struct pmu *pmu)
2859 struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
2861 if (!cpuctx->sched_cb_usage++)
2862 list_add(&cpuctx->sched_cb_entry, this_cpu_ptr(&sched_cb_list));
2864 this_cpu_inc(perf_sched_cb_usages);
2868 * This function provides the context switch callback to the lower code
2869 * layer. It is invoked ONLY when the context switch callback is enabled.
2871 * This callback is relevant even to per-cpu events; for example multi event
2872 * PEBS requires this to provide PID/TID information. This requires we flush
2873 * all queued PEBS records before we context switch to a new task.
2875 static void perf_pmu_sched_task(struct task_struct *prev,
2876 struct task_struct *next,
2879 struct perf_cpu_context *cpuctx;
2885 list_for_each_entry(cpuctx, this_cpu_ptr(&sched_cb_list), sched_cb_entry) {
2886 pmu = cpuctx->unique_pmu; /* software PMUs will not have sched_task */
2888 if (WARN_ON_ONCE(!pmu->sched_task))
2891 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
2892 perf_pmu_disable(pmu);
2894 pmu->sched_task(cpuctx->task_ctx, sched_in);
2896 perf_pmu_enable(pmu);
2897 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
2901 static void perf_event_switch(struct task_struct *task,
2902 struct task_struct *next_prev, bool sched_in);
2904 #define for_each_task_context_nr(ctxn) \
2905 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2908 * Called from scheduler to remove the events of the current task,
2909 * with interrupts disabled.
2911 * We stop each event and update the event value in event->count.
2913 * This does not protect us against NMI, but disable()
2914 * sets the disabled bit in the control field of event _before_
2915 * accessing the event control register. If a NMI hits, then it will
2916 * not restart the event.
2918 void __perf_event_task_sched_out(struct task_struct *task,
2919 struct task_struct *next)
2923 if (__this_cpu_read(perf_sched_cb_usages))
2924 perf_pmu_sched_task(task, next, false);
2926 if (atomic_read(&nr_switch_events))
2927 perf_event_switch(task, next, false);
2929 for_each_task_context_nr(ctxn)
2930 perf_event_context_sched_out(task, ctxn, next);
2933 * if cgroup events exist on this CPU, then we need
2934 * to check if we have to switch out PMU state.
2935 * cgroup event are system-wide mode only
2937 if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
2938 perf_cgroup_sched_out(task, next);
2942 * Called with IRQs disabled
2944 static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
2945 enum event_type_t event_type)
2947 ctx_sched_out(&cpuctx->ctx, cpuctx, event_type);
2951 ctx_pinned_sched_in(struct perf_event_context *ctx,
2952 struct perf_cpu_context *cpuctx)
2954 struct perf_event *event;
2956 list_for_each_entry(event, &ctx->pinned_groups, group_entry) {
2957 if (event->state <= PERF_EVENT_STATE_OFF)
2959 if (!event_filter_match(event))
2962 /* may need to reset tstamp_enabled */
2963 if (is_cgroup_event(event))
2964 perf_cgroup_mark_enabled(event, ctx);
2966 if (group_can_go_on(event, cpuctx, 1))
2967 group_sched_in(event, cpuctx, ctx);
2970 * If this pinned group hasn't been scheduled,
2971 * put it in error state.
2973 if (event->state == PERF_EVENT_STATE_INACTIVE) {
2974 update_group_times(event);
2975 event->state = PERF_EVENT_STATE_ERROR;
2981 ctx_flexible_sched_in(struct perf_event_context *ctx,
2982 struct perf_cpu_context *cpuctx)
2984 struct perf_event *event;
2987 list_for_each_entry(event, &ctx->flexible_groups, group_entry) {
2988 /* Ignore events in OFF or ERROR state */
2989 if (event->state <= PERF_EVENT_STATE_OFF)
2992 * Listen to the 'cpu' scheduling filter constraint
2995 if (!event_filter_match(event))
2998 /* may need to reset tstamp_enabled */
2999 if (is_cgroup_event(event))
3000 perf_cgroup_mark_enabled(event, ctx);
3002 if (group_can_go_on(event, cpuctx, can_add_hw)) {
3003 if (group_sched_in(event, cpuctx, ctx))
3010 ctx_sched_in(struct perf_event_context *ctx,
3011 struct perf_cpu_context *cpuctx,
3012 enum event_type_t event_type,
3013 struct task_struct *task)
3015 int is_active = ctx->is_active;
3018 lockdep_assert_held(&ctx->lock);
3020 if (likely(!ctx->nr_events))
3023 ctx->is_active |= (event_type | EVENT_TIME);
3026 cpuctx->task_ctx = ctx;
3028 WARN_ON_ONCE(cpuctx->task_ctx != ctx);
3031 is_active ^= ctx->is_active; /* changed bits */
3033 if (is_active & EVENT_TIME) {
3034 /* start ctx time */
3036 ctx->timestamp = now;
3037 perf_cgroup_set_timestamp(task, ctx);
3041 * First go through the list and put on any pinned groups
3042 * in order to give them the best chance of going on.
3044 if (is_active & EVENT_PINNED)
3045 ctx_pinned_sched_in(ctx, cpuctx);
3047 /* Then walk through the lower prio flexible groups */
3048 if (is_active & EVENT_FLEXIBLE)
3049 ctx_flexible_sched_in(ctx, cpuctx);
3052 static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
3053 enum event_type_t event_type,
3054 struct task_struct *task)
3056 struct perf_event_context *ctx = &cpuctx->ctx;
3058 ctx_sched_in(ctx, cpuctx, event_type, task);
3061 static void perf_event_context_sched_in(struct perf_event_context *ctx,
3062 struct task_struct *task)
3064 struct perf_cpu_context *cpuctx;
3066 cpuctx = __get_cpu_context(ctx);
3067 if (cpuctx->task_ctx == ctx)
3070 perf_ctx_lock(cpuctx, ctx);
3071 perf_pmu_disable(ctx->pmu);
3073 * We want to keep the following priority order:
3074 * cpu pinned (that don't need to move), task pinned,
3075 * cpu flexible, task flexible.
3077 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
3078 perf_event_sched_in(cpuctx, ctx, task);
3079 perf_pmu_enable(ctx->pmu);
3080 perf_ctx_unlock(cpuctx, ctx);
3084 * Called from scheduler to add the events of the current task
3085 * with interrupts disabled.
3087 * We restore the event value and then enable it.
3089 * This does not protect us against NMI, but enable()
3090 * sets the enabled bit in the control field of event _before_
3091 * accessing the event control register. If a NMI hits, then it will
3092 * keep the event running.
3094 void __perf_event_task_sched_in(struct task_struct *prev,
3095 struct task_struct *task)
3097 struct perf_event_context *ctx;
3101 * If cgroup events exist on this CPU, then we need to check if we have
3102 * to switch in PMU state; cgroup event are system-wide mode only.
3104 * Since cgroup events are CPU events, we must schedule these in before
3105 * we schedule in the task events.
3107 if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
3108 perf_cgroup_sched_in(prev, task);
3110 for_each_task_context_nr(ctxn) {
3111 ctx = task->perf_event_ctxp[ctxn];
3115 perf_event_context_sched_in(ctx, task);
3118 if (atomic_read(&nr_switch_events))
3119 perf_event_switch(task, prev, true);
3121 if (__this_cpu_read(perf_sched_cb_usages))
3122 perf_pmu_sched_task(prev, task, true);
3125 static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
3127 u64 frequency = event->attr.sample_freq;
3128 u64 sec = NSEC_PER_SEC;
3129 u64 divisor, dividend;
3131 int count_fls, nsec_fls, frequency_fls, sec_fls;
3133 count_fls = fls64(count);
3134 nsec_fls = fls64(nsec);
3135 frequency_fls = fls64(frequency);
3139 * We got @count in @nsec, with a target of sample_freq HZ
3140 * the target period becomes:
3143 * period = -------------------
3144 * @nsec * sample_freq
3149 * Reduce accuracy by one bit such that @a and @b converge
3150 * to a similar magnitude.
3152 #define REDUCE_FLS(a, b) \
3154 if (a##_fls > b##_fls) { \
3164 * Reduce accuracy until either term fits in a u64, then proceed with
3165 * the other, so that finally we can do a u64/u64 division.
3167 while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) {
3168 REDUCE_FLS(nsec, frequency);
3169 REDUCE_FLS(sec, count);
3172 if (count_fls + sec_fls > 64) {
3173 divisor = nsec * frequency;
3175 while (count_fls + sec_fls > 64) {
3176 REDUCE_FLS(count, sec);
3180 dividend = count * sec;
3182 dividend = count * sec;
3184 while (nsec_fls + frequency_fls > 64) {
3185 REDUCE_FLS(nsec, frequency);
3189 divisor = nsec * frequency;
3195 return div64_u64(dividend, divisor);
3198 static DEFINE_PER_CPU(int, perf_throttled_count);
3199 static DEFINE_PER_CPU(u64, perf_throttled_seq);
3201 static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable)
3203 struct hw_perf_event *hwc = &event->hw;
3204 s64 period, sample_period;
3207 period = perf_calculate_period(event, nsec, count);
3209 delta = (s64)(period - hwc->sample_period);
3210 delta = (delta + 7) / 8; /* low pass filter */
3212 sample_period = hwc->sample_period + delta;
3217 hwc->sample_period = sample_period;
3219 if (local64_read(&hwc->period_left) > 8*sample_period) {
3221 event->pmu->stop(event, PERF_EF_UPDATE);
3223 local64_set(&hwc->period_left, 0);
3226 event->pmu->start(event, PERF_EF_RELOAD);
3231 * combine freq adjustment with unthrottling to avoid two passes over the
3232 * events. At the same time, make sure, having freq events does not change
3233 * the rate of unthrottling as that would introduce bias.
3235 static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx,
3238 struct perf_event *event;
3239 struct hw_perf_event *hwc;
3240 u64 now, period = TICK_NSEC;
3244 * only need to iterate over all events iff:
3245 * - context have events in frequency mode (needs freq adjust)
3246 * - there are events to unthrottle on this cpu
3248 if (!(ctx->nr_freq || needs_unthr))
3251 raw_spin_lock(&ctx->lock);
3252 perf_pmu_disable(ctx->pmu);
3254 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
3255 if (event->state != PERF_EVENT_STATE_ACTIVE)
3258 if (!event_filter_match(event))
3261 perf_pmu_disable(event->pmu);
3265 if (hwc->interrupts == MAX_INTERRUPTS) {
3266 hwc->interrupts = 0;
3267 perf_log_throttle(event, 1);
3268 event->pmu->start(event, 0);
3271 if (!event->attr.freq || !event->attr.sample_freq)
3275 * stop the event and update event->count
3277 event->pmu->stop(event, PERF_EF_UPDATE);
3279 now = local64_read(&event->count);
3280 delta = now - hwc->freq_count_stamp;
3281 hwc->freq_count_stamp = now;
3285 * reload only if value has changed
3286 * we have stopped the event so tell that
3287 * to perf_adjust_period() to avoid stopping it
3291 perf_adjust_period(event, period, delta, false);
3293 event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
3295 perf_pmu_enable(event->pmu);
3298 perf_pmu_enable(ctx->pmu);
3299 raw_spin_unlock(&ctx->lock);
3303 * Round-robin a context's events:
3305 static void rotate_ctx(struct perf_event_context *ctx)
3308 * Rotate the first entry last of non-pinned groups. Rotation might be
3309 * disabled by the inheritance code.
3311 if (!ctx->rotate_disable)
3312 list_rotate_left(&ctx->flexible_groups);
3315 static int perf_rotate_context(struct perf_cpu_context *cpuctx)
3317 struct perf_event_context *ctx = NULL;
3320 if (cpuctx->ctx.nr_events) {
3321 if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
3325 ctx = cpuctx->task_ctx;
3326 if (ctx && ctx->nr_events) {
3327 if (ctx->nr_events != ctx->nr_active)
3334 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
3335 perf_pmu_disable(cpuctx->ctx.pmu);
3337 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
3339 ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE);
3341 rotate_ctx(&cpuctx->ctx);
3345 perf_event_sched_in(cpuctx, ctx, current);
3347 perf_pmu_enable(cpuctx->ctx.pmu);
3348 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
3354 void perf_event_task_tick(void)
3356 struct list_head *head = this_cpu_ptr(&active_ctx_list);
3357 struct perf_event_context *ctx, *tmp;
3360 WARN_ON(!irqs_disabled());
3362 __this_cpu_inc(perf_throttled_seq);
3363 throttled = __this_cpu_xchg(perf_throttled_count, 0);
3364 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
3366 list_for_each_entry_safe(ctx, tmp, head, active_ctx_list)
3367 perf_adjust_freq_unthr_context(ctx, throttled);
3370 static int event_enable_on_exec(struct perf_event *event,
3371 struct perf_event_context *ctx)
3373 if (!event->attr.enable_on_exec)
3376 event->attr.enable_on_exec = 0;
3377 if (event->state >= PERF_EVENT_STATE_INACTIVE)
3380 __perf_event_mark_enabled(event);
3386 * Enable all of a task's events that have been marked enable-on-exec.
3387 * This expects task == current.
3389 static void perf_event_enable_on_exec(int ctxn)
3391 struct perf_event_context *ctx, *clone_ctx = NULL;
3392 struct perf_cpu_context *cpuctx;
3393 struct perf_event *event;
3394 unsigned long flags;
3397 local_irq_save(flags);
3398 ctx = current->perf_event_ctxp[ctxn];
3399 if (!ctx || !ctx->nr_events)
3402 cpuctx = __get_cpu_context(ctx);
3403 perf_ctx_lock(cpuctx, ctx);
3404 ctx_sched_out(ctx, cpuctx, EVENT_TIME);
3405 list_for_each_entry(event, &ctx->event_list, event_entry)
3406 enabled |= event_enable_on_exec(event, ctx);
3409 * Unclone and reschedule this context if we enabled any event.
3412 clone_ctx = unclone_ctx(ctx);
3413 ctx_resched(cpuctx, ctx);
3415 perf_ctx_unlock(cpuctx, ctx);
3418 local_irq_restore(flags);
3424 struct perf_read_data {
3425 struct perf_event *event;
3431 * Cross CPU call to read the hardware event
3433 static void __perf_event_read(void *info)
3435 struct perf_read_data *data = info;
3436 struct perf_event *sub, *event = data->event;
3437 struct perf_event_context *ctx = event->ctx;
3438 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
3439 struct pmu *pmu = event->pmu;
3442 * If this is a task context, we need to check whether it is
3443 * the current task context of this cpu. If not it has been
3444 * scheduled out before the smp call arrived. In that case
3445 * event->count would have been updated to a recent sample
3446 * when the event was scheduled out.
3448 if (ctx->task && cpuctx->task_ctx != ctx)
3451 raw_spin_lock(&ctx->lock);
3452 if (ctx->is_active) {
3453 update_context_time(ctx);
3454 update_cgrp_time_from_event(event);
3457 update_event_times(event);
3458 if (event->state != PERF_EVENT_STATE_ACTIVE)
3467 pmu->start_txn(pmu, PERF_PMU_TXN_READ);
3471 list_for_each_entry(sub, &event->sibling_list, group_entry) {
3472 update_event_times(sub);
3473 if (sub->state == PERF_EVENT_STATE_ACTIVE) {
3475 * Use sibling's PMU rather than @event's since
3476 * sibling could be on different (eg: software) PMU.
3478 sub->pmu->read(sub);
3482 data->ret = pmu->commit_txn(pmu);
3485 raw_spin_unlock(&ctx->lock);
3488 static inline u64 perf_event_count(struct perf_event *event)
3490 if (event->pmu->count)
3491 return event->pmu->count(event);
3493 return __perf_event_count(event);
3497 * NMI-safe method to read a local event, that is an event that
3499 * - either for the current task, or for this CPU
3500 * - does not have inherit set, for inherited task events
3501 * will not be local and we cannot read them atomically
3502 * - must not have a pmu::count method
3504 u64 perf_event_read_local(struct perf_event *event)
3506 unsigned long flags;
3510 * Disabling interrupts avoids all counter scheduling (context
3511 * switches, timer based rotation and IPIs).
3513 local_irq_save(flags);
3515 /* If this is a per-task event, it must be for current */
3516 WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) &&
3517 event->hw.target != current);
3519 /* If this is a per-CPU event, it must be for this CPU */
3520 WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) &&
3521 event->cpu != smp_processor_id());
3524 * It must not be an event with inherit set, we cannot read
3525 * all child counters from atomic context.
3527 WARN_ON_ONCE(event->attr.inherit);
3530 * It must not have a pmu::count method, those are not
3533 WARN_ON_ONCE(event->pmu->count);
3536 * If the event is currently on this CPU, its either a per-task event,
3537 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3540 if (event->oncpu == smp_processor_id())
3541 event->pmu->read(event);
3543 val = local64_read(&event->count);
3544 local_irq_restore(flags);
3549 static int perf_event_read(struct perf_event *event, bool group)
3554 * If event is enabled and currently active on a CPU, update the
3555 * value in the event structure:
3557 if (event->state == PERF_EVENT_STATE_ACTIVE) {
3558 struct perf_read_data data = {
3563 ret = smp_call_function_single(event->oncpu, __perf_event_read, &data, 1);
3564 /* The event must have been read from an online CPU: */
3566 ret = ret ? : data.ret;
3567 } else if (event->state == PERF_EVENT_STATE_INACTIVE) {
3568 struct perf_event_context *ctx = event->ctx;
3569 unsigned long flags;
3571 raw_spin_lock_irqsave(&ctx->lock, flags);
3573 * may read while context is not active
3574 * (e.g., thread is blocked), in that case
3575 * we cannot update context time
3577 if (ctx->is_active) {
3578 update_context_time(ctx);
3579 update_cgrp_time_from_event(event);
3582 update_group_times(event);
3584 update_event_times(event);
3585 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3592 * Initialize the perf_event context in a task_struct:
3594 static void __perf_event_init_context(struct perf_event_context *ctx)
3596 raw_spin_lock_init(&ctx->lock);
3597 mutex_init(&ctx->mutex);
3598 INIT_LIST_HEAD(&ctx->active_ctx_list);
3599 INIT_LIST_HEAD(&ctx->pinned_groups);
3600 INIT_LIST_HEAD(&ctx->flexible_groups);
3601 INIT_LIST_HEAD(&ctx->event_list);
3602 atomic_set(&ctx->refcount, 1);
3605 static struct perf_event_context *
3606 alloc_perf_context(struct pmu *pmu, struct task_struct *task)
3608 struct perf_event_context *ctx;
3610 ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
3614 __perf_event_init_context(ctx);
3617 get_task_struct(task);
3624 static struct task_struct *
3625 find_lively_task_by_vpid(pid_t vpid)
3627 struct task_struct *task;
3633 task = find_task_by_vpid(vpid);
3635 get_task_struct(task);
3639 return ERR_PTR(-ESRCH);
3645 * Returns a matching context with refcount and pincount.
3647 static struct perf_event_context *
3648 find_get_context(struct pmu *pmu, struct task_struct *task,
3649 struct perf_event *event)
3651 struct perf_event_context *ctx, *clone_ctx = NULL;
3652 struct perf_cpu_context *cpuctx;
3653 void *task_ctx_data = NULL;
3654 unsigned long flags;
3656 int cpu = event->cpu;
3659 /* Must be root to operate on a CPU event: */
3660 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
3661 return ERR_PTR(-EACCES);
3664 * We could be clever and allow to attach a event to an
3665 * offline CPU and activate it when the CPU comes up, but
3668 if (!cpu_online(cpu))
3669 return ERR_PTR(-ENODEV);
3671 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
3680 ctxn = pmu->task_ctx_nr;
3684 if (event->attach_state & PERF_ATTACH_TASK_DATA) {
3685 task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL);
3686 if (!task_ctx_data) {
3693 ctx = perf_lock_task_context(task, ctxn, &flags);
3695 clone_ctx = unclone_ctx(ctx);
3698 if (task_ctx_data && !ctx->task_ctx_data) {
3699 ctx->task_ctx_data = task_ctx_data;
3700 task_ctx_data = NULL;
3702 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3707 ctx = alloc_perf_context(pmu, task);
3712 if (task_ctx_data) {
3713 ctx->task_ctx_data = task_ctx_data;
3714 task_ctx_data = NULL;
3718 mutex_lock(&task->perf_event_mutex);
3720 * If it has already passed perf_event_exit_task().
3721 * we must see PF_EXITING, it takes this mutex too.
3723 if (task->flags & PF_EXITING)
3725 else if (task->perf_event_ctxp[ctxn])
3730 rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
3732 mutex_unlock(&task->perf_event_mutex);
3734 if (unlikely(err)) {
3743 kfree(task_ctx_data);
3747 kfree(task_ctx_data);
3748 return ERR_PTR(err);
3751 static void perf_event_free_filter(struct perf_event *event);
3752 static void perf_event_free_bpf_prog(struct perf_event *event);
3754 static void free_event_rcu(struct rcu_head *head)
3756 struct perf_event *event;
3758 event = container_of(head, struct perf_event, rcu_head);
3760 put_pid_ns(event->ns);
3761 perf_event_free_filter(event);
3765 static void ring_buffer_attach(struct perf_event *event,
3766 struct ring_buffer *rb);
3768 static void detach_sb_event(struct perf_event *event)
3770 struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
3772 raw_spin_lock(&pel->lock);
3773 list_del_rcu(&event->sb_list);
3774 raw_spin_unlock(&pel->lock);
3777 static bool is_sb_event(struct perf_event *event)
3779 struct perf_event_attr *attr = &event->attr;
3784 if (event->attach_state & PERF_ATTACH_TASK)
3787 if (attr->mmap || attr->mmap_data || attr->mmap2 ||
3788 attr->comm || attr->comm_exec ||
3790 attr->context_switch)
3795 static void unaccount_pmu_sb_event(struct perf_event *event)
3797 if (is_sb_event(event))
3798 detach_sb_event(event);
3801 static void unaccount_event_cpu(struct perf_event *event, int cpu)
3806 if (is_cgroup_event(event))
3807 atomic_dec(&per_cpu(perf_cgroup_events, cpu));
3810 #ifdef CONFIG_NO_HZ_FULL
3811 static DEFINE_SPINLOCK(nr_freq_lock);
3814 static void unaccount_freq_event_nohz(void)
3816 #ifdef CONFIG_NO_HZ_FULL
3817 spin_lock(&nr_freq_lock);
3818 if (atomic_dec_and_test(&nr_freq_events))
3819 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS);
3820 spin_unlock(&nr_freq_lock);
3824 static void unaccount_freq_event(void)
3826 if (tick_nohz_full_enabled())
3827 unaccount_freq_event_nohz();
3829 atomic_dec(&nr_freq_events);
3832 static void unaccount_event(struct perf_event *event)
3839 if (event->attach_state & PERF_ATTACH_TASK)
3841 if (event->attr.mmap || event->attr.mmap_data)
3842 atomic_dec(&nr_mmap_events);
3843 if (event->attr.comm)
3844 atomic_dec(&nr_comm_events);
3845 if (event->attr.task)
3846 atomic_dec(&nr_task_events);
3847 if (event->attr.freq)
3848 unaccount_freq_event();
3849 if (event->attr.context_switch) {
3851 atomic_dec(&nr_switch_events);
3853 if (is_cgroup_event(event))
3855 if (has_branch_stack(event))
3859 if (!atomic_add_unless(&perf_sched_count, -1, 1))
3860 schedule_delayed_work(&perf_sched_work, HZ);
3863 unaccount_event_cpu(event, event->cpu);
3865 unaccount_pmu_sb_event(event);
3868 static void perf_sched_delayed(struct work_struct *work)
3870 mutex_lock(&perf_sched_mutex);
3871 if (atomic_dec_and_test(&perf_sched_count))
3872 static_branch_disable(&perf_sched_events);
3873 mutex_unlock(&perf_sched_mutex);
3877 * The following implement mutual exclusion of events on "exclusive" pmus
3878 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3879 * at a time, so we disallow creating events that might conflict, namely:
3881 * 1) cpu-wide events in the presence of per-task events,
3882 * 2) per-task events in the presence of cpu-wide events,
3883 * 3) two matching events on the same context.
3885 * The former two cases are handled in the allocation path (perf_event_alloc(),
3886 * _free_event()), the latter -- before the first perf_install_in_context().
3888 static int exclusive_event_init(struct perf_event *event)
3890 struct pmu *pmu = event->pmu;
3892 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3896 * Prevent co-existence of per-task and cpu-wide events on the
3897 * same exclusive pmu.
3899 * Negative pmu::exclusive_cnt means there are cpu-wide
3900 * events on this "exclusive" pmu, positive means there are
3903 * Since this is called in perf_event_alloc() path, event::ctx
3904 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3905 * to mean "per-task event", because unlike other attach states it
3906 * never gets cleared.
3908 if (event->attach_state & PERF_ATTACH_TASK) {
3909 if (!atomic_inc_unless_negative(&pmu->exclusive_cnt))
3912 if (!atomic_dec_unless_positive(&pmu->exclusive_cnt))
3919 static void exclusive_event_destroy(struct perf_event *event)
3921 struct pmu *pmu = event->pmu;
3923 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3926 /* see comment in exclusive_event_init() */
3927 if (event->attach_state & PERF_ATTACH_TASK)
3928 atomic_dec(&pmu->exclusive_cnt);
3930 atomic_inc(&pmu->exclusive_cnt);
3933 static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2)
3935 if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) &&
3936 (e1->cpu == e2->cpu ||
3943 /* Called under the same ctx::mutex as perf_install_in_context() */
3944 static bool exclusive_event_installable(struct perf_event *event,
3945 struct perf_event_context *ctx)
3947 struct perf_event *iter_event;
3948 struct pmu *pmu = event->pmu;
3950 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3953 list_for_each_entry(iter_event, &ctx->event_list, event_entry) {
3954 if (exclusive_event_match(iter_event, event))
3961 static void perf_addr_filters_splice(struct perf_event *event,
3962 struct list_head *head);
3964 static void _free_event(struct perf_event *event)
3966 irq_work_sync(&event->pending);
3968 unaccount_event(event);
3972 * Can happen when we close an event with re-directed output.
3974 * Since we have a 0 refcount, perf_mmap_close() will skip
3975 * over us; possibly making our ring_buffer_put() the last.
3977 mutex_lock(&event->mmap_mutex);
3978 ring_buffer_attach(event, NULL);
3979 mutex_unlock(&event->mmap_mutex);
3982 if (is_cgroup_event(event))
3983 perf_detach_cgroup(event);
3985 if (!event->parent) {
3986 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
3987 put_callchain_buffers();
3990 perf_event_free_bpf_prog(event);
3991 perf_addr_filters_splice(event, NULL);
3992 kfree(event->addr_filters_offs);
3995 event->destroy(event);
3998 put_ctx(event->ctx);
4000 exclusive_event_destroy(event);
4001 module_put(event->pmu->module);
4003 call_rcu(&event->rcu_head, free_event_rcu);
4007 * Used to free events which have a known refcount of 1, such as in error paths
4008 * where the event isn't exposed yet and inherited events.
4010 static void free_event(struct perf_event *event)
4012 if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1,
4013 "unexpected event refcount: %ld; ptr=%p\n",
4014 atomic_long_read(&event->refcount), event)) {
4015 /* leak to avoid use-after-free */
4023 * Remove user event from the owner task.
4025 static void perf_remove_from_owner(struct perf_event *event)
4027 struct task_struct *owner;
4031 * Matches the smp_store_release() in perf_event_exit_task(). If we
4032 * observe !owner it means the list deletion is complete and we can
4033 * indeed free this event, otherwise we need to serialize on
4034 * owner->perf_event_mutex.
4036 owner = lockless_dereference(event->owner);
4039 * Since delayed_put_task_struct() also drops the last
4040 * task reference we can safely take a new reference
4041 * while holding the rcu_read_lock().
4043 get_task_struct(owner);
4049 * If we're here through perf_event_exit_task() we're already
4050 * holding ctx->mutex which would be an inversion wrt. the
4051 * normal lock order.
4053 * However we can safely take this lock because its the child
4056 mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING);
4059 * We have to re-check the event->owner field, if it is cleared
4060 * we raced with perf_event_exit_task(), acquiring the mutex
4061 * ensured they're done, and we can proceed with freeing the
4065 list_del_init(&event->owner_entry);
4066 smp_store_release(&event->owner, NULL);
4068 mutex_unlock(&owner->perf_event_mutex);
4069 put_task_struct(owner);
4073 static void put_event(struct perf_event *event)
4075 if (!atomic_long_dec_and_test(&event->refcount))
4082 * Kill an event dead; while event:refcount will preserve the event
4083 * object, it will not preserve its functionality. Once the last 'user'
4084 * gives up the object, we'll destroy the thing.
4086 int perf_event_release_kernel(struct perf_event *event)
4088 struct perf_event_context *ctx = event->ctx;
4089 struct perf_event *child, *tmp;
4092 * If we got here through err_file: fput(event_file); we will not have
4093 * attached to a context yet.
4096 WARN_ON_ONCE(event->attach_state &
4097 (PERF_ATTACH_CONTEXT|PERF_ATTACH_GROUP));
4101 if (!is_kernel_event(event))
4102 perf_remove_from_owner(event);
4104 ctx = perf_event_ctx_lock(event);
4105 WARN_ON_ONCE(ctx->parent_ctx);
4106 perf_remove_from_context(event, DETACH_GROUP);
4108 raw_spin_lock_irq(&ctx->lock);
4110 * Mark this even as STATE_DEAD, there is no external reference to it
4113 * Anybody acquiring event->child_mutex after the below loop _must_
4114 * also see this, most importantly inherit_event() which will avoid
4115 * placing more children on the list.
4117 * Thus this guarantees that we will in fact observe and kill _ALL_
4120 event->state = PERF_EVENT_STATE_DEAD;
4121 raw_spin_unlock_irq(&ctx->lock);
4123 perf_event_ctx_unlock(event, ctx);
4126 mutex_lock(&event->child_mutex);
4127 list_for_each_entry(child, &event->child_list, child_list) {
4130 * Cannot change, child events are not migrated, see the
4131 * comment with perf_event_ctx_lock_nested().
4133 ctx = lockless_dereference(child->ctx);
4135 * Since child_mutex nests inside ctx::mutex, we must jump
4136 * through hoops. We start by grabbing a reference on the ctx.
4138 * Since the event cannot get freed while we hold the
4139 * child_mutex, the context must also exist and have a !0
4145 * Now that we have a ctx ref, we can drop child_mutex, and
4146 * acquire ctx::mutex without fear of it going away. Then we
4147 * can re-acquire child_mutex.
4149 mutex_unlock(&event->child_mutex);
4150 mutex_lock(&ctx->mutex);
4151 mutex_lock(&event->child_mutex);
4154 * Now that we hold ctx::mutex and child_mutex, revalidate our
4155 * state, if child is still the first entry, it didn't get freed
4156 * and we can continue doing so.
4158 tmp = list_first_entry_or_null(&event->child_list,
4159 struct perf_event, child_list);
4161 perf_remove_from_context(child, DETACH_GROUP);
4162 list_del(&child->child_list);
4165 * This matches the refcount bump in inherit_event();
4166 * this can't be the last reference.
4171 mutex_unlock(&event->child_mutex);
4172 mutex_unlock(&ctx->mutex);
4176 mutex_unlock(&event->child_mutex);
4179 put_event(event); /* Must be the 'last' reference */
4182 EXPORT_SYMBOL_GPL(perf_event_release_kernel);
4185 * Called when the last reference to the file is gone.
4187 static int perf_release(struct inode *inode, struct file *file)
4189 perf_event_release_kernel(file->private_data);
4193 u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
4195 struct perf_event *child;
4201 mutex_lock(&event->child_mutex);
4203 (void)perf_event_read(event, false);
4204 total += perf_event_count(event);
4206 *enabled += event->total_time_enabled +
4207 atomic64_read(&event->child_total_time_enabled);
4208 *running += event->total_time_running +
4209 atomic64_read(&event->child_total_time_running);
4211 list_for_each_entry(child, &event->child_list, child_list) {
4212 (void)perf_event_read(child, false);
4213 total += perf_event_count(child);
4214 *enabled += child->total_time_enabled;
4215 *running += child->total_time_running;
4217 mutex_unlock(&event->child_mutex);
4221 EXPORT_SYMBOL_GPL(perf_event_read_value);
4223 static int __perf_read_group_add(struct perf_event *leader,
4224 u64 read_format, u64 *values)
4226 struct perf_event *sub;
4227 int n = 1; /* skip @nr */
4230 ret = perf_event_read(leader, true);
4235 * Since we co-schedule groups, {enabled,running} times of siblings
4236 * will be identical to those of the leader, so we only publish one
4239 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
4240 values[n++] += leader->total_time_enabled +
4241 atomic64_read(&leader->child_total_time_enabled);
4244 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
4245 values[n++] += leader->total_time_running +
4246 atomic64_read(&leader->child_total_time_running);
4250 * Write {count,id} tuples for every sibling.
4252 values[n++] += perf_event_count(leader);
4253 if (read_format & PERF_FORMAT_ID)
4254 values[n++] = primary_event_id(leader);
4256 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
4257 values[n++] += perf_event_count(sub);
4258 if (read_format & PERF_FORMAT_ID)
4259 values[n++] = primary_event_id(sub);
4265 static int perf_read_group(struct perf_event *event,
4266 u64 read_format, char __user *buf)
4268 struct perf_event *leader = event->group_leader, *child;
4269 struct perf_event_context *ctx = leader->ctx;
4273 lockdep_assert_held(&ctx->mutex);
4275 values = kzalloc(event->read_size, GFP_KERNEL);
4279 values[0] = 1 + leader->nr_siblings;
4282 * By locking the child_mutex of the leader we effectively
4283 * lock the child list of all siblings.. XXX explain how.
4285 mutex_lock(&leader->child_mutex);
4287 ret = __perf_read_group_add(leader, read_format, values);
4291 list_for_each_entry(child, &leader->child_list, child_list) {
4292 ret = __perf_read_group_add(child, read_format, values);
4297 mutex_unlock(&leader->child_mutex);
4299 ret = event->read_size;
4300 if (copy_to_user(buf, values, event->read_size))
4305 mutex_unlock(&leader->child_mutex);
4311 static int perf_read_one(struct perf_event *event,
4312 u64 read_format, char __user *buf)
4314 u64 enabled, running;
4318 values[n++] = perf_event_read_value(event, &enabled, &running);
4319 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
4320 values[n++] = enabled;
4321 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
4322 values[n++] = running;
4323 if (read_format & PERF_FORMAT_ID)
4324 values[n++] = primary_event_id(event);
4326 if (copy_to_user(buf, values, n * sizeof(u64)))
4329 return n * sizeof(u64);
4332 static bool is_event_hup(struct perf_event *event)
4336 if (event->state > PERF_EVENT_STATE_EXIT)
4339 mutex_lock(&event->child_mutex);
4340 no_children = list_empty(&event->child_list);
4341 mutex_unlock(&event->child_mutex);
4346 * Read the performance event - simple non blocking version for now
4349 __perf_read(struct perf_event *event, char __user *buf, size_t count)
4351 u64 read_format = event->attr.read_format;
4355 * Return end-of-file for a read on a event that is in
4356 * error state (i.e. because it was pinned but it couldn't be
4357 * scheduled on to the CPU at some point).
4359 if (event->state == PERF_EVENT_STATE_ERROR)
4362 if (count < event->read_size)
4365 WARN_ON_ONCE(event->ctx->parent_ctx);
4366 if (read_format & PERF_FORMAT_GROUP)
4367 ret = perf_read_group(event, read_format, buf);
4369 ret = perf_read_one(event, read_format, buf);
4375 perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
4377 struct perf_event *event = file->private_data;
4378 struct perf_event_context *ctx;
4381 ctx = perf_event_ctx_lock(event);
4382 ret = __perf_read(event, buf, count);
4383 perf_event_ctx_unlock(event, ctx);
4388 static unsigned int perf_poll(struct file *file, poll_table *wait)
4390 struct perf_event *event = file->private_data;
4391 struct ring_buffer *rb;
4392 unsigned int events = POLLHUP;
4394 poll_wait(file, &event->waitq, wait);
4396 if (is_event_hup(event))
4400 * Pin the event->rb by taking event->mmap_mutex; otherwise
4401 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4403 mutex_lock(&event->mmap_mutex);
4406 events = atomic_xchg(&rb->poll, 0);
4407 mutex_unlock(&event->mmap_mutex);
4411 static void _perf_event_reset(struct perf_event *event)
4413 (void)perf_event_read(event, false);
4414 local64_set(&event->count, 0);
4415 perf_event_update_userpage(event);
4419 * Holding the top-level event's child_mutex means that any
4420 * descendant process that has inherited this event will block
4421 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4422 * task existence requirements of perf_event_enable/disable.
4424 static void perf_event_for_each_child(struct perf_event *event,
4425 void (*func)(struct perf_event *))
4427 struct perf_event *child;
4429 WARN_ON_ONCE(event->ctx->parent_ctx);
4431 mutex_lock(&event->child_mutex);
4433 list_for_each_entry(child, &event->child_list, child_list)
4435 mutex_unlock(&event->child_mutex);
4438 static void perf_event_for_each(struct perf_event *event,
4439 void (*func)(struct perf_event *))
4441 struct perf_event_context *ctx = event->ctx;
4442 struct perf_event *sibling;
4444 lockdep_assert_held(&ctx->mutex);
4446 event = event->group_leader;
4448 perf_event_for_each_child(event, func);
4449 list_for_each_entry(sibling, &event->sibling_list, group_entry)
4450 perf_event_for_each_child(sibling, func);
4453 static void __perf_event_period(struct perf_event *event,
4454 struct perf_cpu_context *cpuctx,
4455 struct perf_event_context *ctx,
4458 u64 value = *((u64 *)info);
4461 if (event->attr.freq) {
4462 event->attr.sample_freq = value;
4464 event->attr.sample_period = value;
4465 event->hw.sample_period = value;
4468 active = (event->state == PERF_EVENT_STATE_ACTIVE);
4470 perf_pmu_disable(ctx->pmu);
4472 * We could be throttled; unthrottle now to avoid the tick
4473 * trying to unthrottle while we already re-started the event.
4475 if (event->hw.interrupts == MAX_INTERRUPTS) {
4476 event->hw.interrupts = 0;
4477 perf_log_throttle(event, 1);
4479 event->pmu->stop(event, PERF_EF_UPDATE);
4482 local64_set(&event->hw.period_left, 0);
4485 event->pmu->start(event, PERF_EF_RELOAD);
4486 perf_pmu_enable(ctx->pmu);
4490 static int perf_event_period(struct perf_event *event, u64 __user *arg)
4494 if (!is_sampling_event(event))
4497 if (copy_from_user(&value, arg, sizeof(value)))
4503 if (event->attr.freq && value > sysctl_perf_event_sample_rate)
4506 event_function_call(event, __perf_event_period, &value);
4511 static const struct file_operations perf_fops;
4513 static inline int perf_fget_light(int fd, struct fd *p)
4515 struct fd f = fdget(fd);
4519 if (f.file->f_op != &perf_fops) {
4527 static int perf_event_set_output(struct perf_event *event,
4528 struct perf_event *output_event);
4529 static int perf_event_set_filter(struct perf_event *event, void __user *arg);
4530 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd);
4532 static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg)
4534 void (*func)(struct perf_event *);
4538 case PERF_EVENT_IOC_ENABLE:
4539 func = _perf_event_enable;
4541 case PERF_EVENT_IOC_DISABLE:
4542 func = _perf_event_disable;
4544 case PERF_EVENT_IOC_RESET:
4545 func = _perf_event_reset;
4548 case PERF_EVENT_IOC_REFRESH:
4549 return _perf_event_refresh(event, arg);
4551 case PERF_EVENT_IOC_PERIOD:
4552 return perf_event_period(event, (u64 __user *)arg);
4554 case PERF_EVENT_IOC_ID:
4556 u64 id = primary_event_id(event);
4558 if (copy_to_user((void __user *)arg, &id, sizeof(id)))
4563 case PERF_EVENT_IOC_SET_OUTPUT:
4567 struct perf_event *output_event;
4569 ret = perf_fget_light(arg, &output);
4572 output_event = output.file->private_data;
4573 ret = perf_event_set_output(event, output_event);
4576 ret = perf_event_set_output(event, NULL);
4581 case PERF_EVENT_IOC_SET_FILTER:
4582 return perf_event_set_filter(event, (void __user *)arg);
4584 case PERF_EVENT_IOC_SET_BPF:
4585 return perf_event_set_bpf_prog(event, arg);
4587 case PERF_EVENT_IOC_PAUSE_OUTPUT: {
4588 struct ring_buffer *rb;
4591 rb = rcu_dereference(event->rb);
4592 if (!rb || !rb->nr_pages) {
4596 rb_toggle_paused(rb, !!arg);
4604 if (flags & PERF_IOC_FLAG_GROUP)
4605 perf_event_for_each(event, func);
4607 perf_event_for_each_child(event, func);
4612 static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
4614 struct perf_event *event = file->private_data;
4615 struct perf_event_context *ctx;
4618 ctx = perf_event_ctx_lock(event);
4619 ret = _perf_ioctl(event, cmd, arg);
4620 perf_event_ctx_unlock(event, ctx);
4625 #ifdef CONFIG_COMPAT
4626 static long perf_compat_ioctl(struct file *file, unsigned int cmd,
4629 switch (_IOC_NR(cmd)) {
4630 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER):
4631 case _IOC_NR(PERF_EVENT_IOC_ID):
4632 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4633 if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
4634 cmd &= ~IOCSIZE_MASK;
4635 cmd |= sizeof(void *) << IOCSIZE_SHIFT;
4639 return perf_ioctl(file, cmd, arg);
4642 # define perf_compat_ioctl NULL
4645 int perf_event_task_enable(void)
4647 struct perf_event_context *ctx;
4648 struct perf_event *event;
4650 mutex_lock(¤t->perf_event_mutex);
4651 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
4652 ctx = perf_event_ctx_lock(event);
4653 perf_event_for_each_child(event, _perf_event_enable);
4654 perf_event_ctx_unlock(event, ctx);
4656 mutex_unlock(¤t->perf_event_mutex);
4661 int perf_event_task_disable(void)
4663 struct perf_event_context *ctx;
4664 struct perf_event *event;
4666 mutex_lock(¤t->perf_event_mutex);
4667 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
4668 ctx = perf_event_ctx_lock(event);
4669 perf_event_for_each_child(event, _perf_event_disable);
4670 perf_event_ctx_unlock(event, ctx);
4672 mutex_unlock(¤t->perf_event_mutex);
4677 static int perf_event_index(struct perf_event *event)
4679 if (event->hw.state & PERF_HES_STOPPED)
4682 if (event->state != PERF_EVENT_STATE_ACTIVE)
4685 return event->pmu->event_idx(event);
4688 static void calc_timer_values(struct perf_event *event,
4695 *now = perf_clock();
4696 ctx_time = event->shadow_ctx_time + *now;
4697 *enabled = ctx_time - event->tstamp_enabled;
4698 *running = ctx_time - event->tstamp_running;
4701 static void perf_event_init_userpage(struct perf_event *event)
4703 struct perf_event_mmap_page *userpg;
4704 struct ring_buffer *rb;
4707 rb = rcu_dereference(event->rb);
4711 userpg = rb->user_page;
4713 /* Allow new userspace to detect that bit 0 is deprecated */
4714 userpg->cap_bit0_is_deprecated = 1;
4715 userpg->size = offsetof(struct perf_event_mmap_page, __reserved);
4716 userpg->data_offset = PAGE_SIZE;
4717 userpg->data_size = perf_data_size(rb);
4723 void __weak arch_perf_update_userpage(
4724 struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now)
4729 * Callers need to ensure there can be no nesting of this function, otherwise
4730 * the seqlock logic goes bad. We can not serialize this because the arch
4731 * code calls this from NMI context.
4733 void perf_event_update_userpage(struct perf_event *event)
4735 struct perf_event_mmap_page *userpg;
4736 struct ring_buffer *rb;
4737 u64 enabled, running, now;
4740 rb = rcu_dereference(event->rb);
4745 * compute total_time_enabled, total_time_running
4746 * based on snapshot values taken when the event
4747 * was last scheduled in.
4749 * we cannot simply called update_context_time()
4750 * because of locking issue as we can be called in
4753 calc_timer_values(event, &now, &enabled, &running);
4755 userpg = rb->user_page;
4757 * Disable preemption so as to not let the corresponding user-space
4758 * spin too long if we get preempted.
4763 userpg->index = perf_event_index(event);
4764 userpg->offset = perf_event_count(event);
4766 userpg->offset -= local64_read(&event->hw.prev_count);
4768 userpg->time_enabled = enabled +
4769 atomic64_read(&event->child_total_time_enabled);
4771 userpg->time_running = running +
4772 atomic64_read(&event->child_total_time_running);
4774 arch_perf_update_userpage(event, userpg, now);
4783 static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
4785 struct perf_event *event = vma->vm_file->private_data;
4786 struct ring_buffer *rb;
4787 int ret = VM_FAULT_SIGBUS;
4789 if (vmf->flags & FAULT_FLAG_MKWRITE) {
4790 if (vmf->pgoff == 0)
4796 rb = rcu_dereference(event->rb);
4800 if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
4803 vmf->page = perf_mmap_to_page(rb, vmf->pgoff);
4807 get_page(vmf->page);
4808 vmf->page->mapping = vma->vm_file->f_mapping;
4809 vmf->page->index = vmf->pgoff;
4818 static void ring_buffer_attach(struct perf_event *event,
4819 struct ring_buffer *rb)
4821 struct ring_buffer *old_rb = NULL;
4822 unsigned long flags;
4826 * Should be impossible, we set this when removing
4827 * event->rb_entry and wait/clear when adding event->rb_entry.
4829 WARN_ON_ONCE(event->rcu_pending);
4832 spin_lock_irqsave(&old_rb->event_lock, flags);
4833 list_del_rcu(&event->rb_entry);
4834 spin_unlock_irqrestore(&old_rb->event_lock, flags);
4836 event->rcu_batches = get_state_synchronize_rcu();
4837 event->rcu_pending = 1;
4841 if (event->rcu_pending) {
4842 cond_synchronize_rcu(event->rcu_batches);
4843 event->rcu_pending = 0;
4846 spin_lock_irqsave(&rb->event_lock, flags);
4847 list_add_rcu(&event->rb_entry, &rb->event_list);
4848 spin_unlock_irqrestore(&rb->event_lock, flags);
4851 rcu_assign_pointer(event->rb, rb);
4854 ring_buffer_put(old_rb);
4856 * Since we detached before setting the new rb, so that we
4857 * could attach the new rb, we could have missed a wakeup.
4860 wake_up_all(&event->waitq);
4864 static void ring_buffer_wakeup(struct perf_event *event)
4866 struct ring_buffer *rb;
4869 rb = rcu_dereference(event->rb);
4871 list_for_each_entry_rcu(event, &rb->event_list, rb_entry)
4872 wake_up_all(&event->waitq);
4877 struct ring_buffer *ring_buffer_get(struct perf_event *event)
4879 struct ring_buffer *rb;
4882 rb = rcu_dereference(event->rb);
4884 if (!atomic_inc_not_zero(&rb->refcount))
4892 void ring_buffer_put(struct ring_buffer *rb)
4894 if (!atomic_dec_and_test(&rb->refcount))
4897 WARN_ON_ONCE(!list_empty(&rb->event_list));
4899 call_rcu(&rb->rcu_head, rb_free_rcu);
4902 static void perf_mmap_open(struct vm_area_struct *vma)
4904 struct perf_event *event = vma->vm_file->private_data;
4906 atomic_inc(&event->mmap_count);
4907 atomic_inc(&event->rb->mmap_count);
4910 atomic_inc(&event->rb->aux_mmap_count);
4912 if (event->pmu->event_mapped)
4913 event->pmu->event_mapped(event);
4916 static void perf_pmu_output_stop(struct perf_event *event);
4919 * A buffer can be mmap()ed multiple times; either directly through the same
4920 * event, or through other events by use of perf_event_set_output().
4922 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4923 * the buffer here, where we still have a VM context. This means we need
4924 * to detach all events redirecting to us.
4926 static void perf_mmap_close(struct vm_area_struct *vma)
4928 struct perf_event *event = vma->vm_file->private_data;
4930 struct ring_buffer *rb = ring_buffer_get(event);
4931 struct user_struct *mmap_user = rb->mmap_user;
4932 int mmap_locked = rb->mmap_locked;
4933 unsigned long size = perf_data_size(rb);
4935 if (event->pmu->event_unmapped)
4936 event->pmu->event_unmapped(event);
4939 * rb->aux_mmap_count will always drop before rb->mmap_count and
4940 * event->mmap_count, so it is ok to use event->mmap_mutex to
4941 * serialize with perf_mmap here.
4943 if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff &&
4944 atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) {
4946 * Stop all AUX events that are writing to this buffer,
4947 * so that we can free its AUX pages and corresponding PMU
4948 * data. Note that after rb::aux_mmap_count dropped to zero,
4949 * they won't start any more (see perf_aux_output_begin()).
4951 perf_pmu_output_stop(event);
4953 /* now it's safe to free the pages */
4954 atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm);
4955 vma->vm_mm->pinned_vm -= rb->aux_mmap_locked;
4957 /* this has to be the last one */
4959 WARN_ON_ONCE(atomic_read(&rb->aux_refcount));
4961 mutex_unlock(&event->mmap_mutex);
4964 atomic_dec(&rb->mmap_count);
4966 if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
4969 ring_buffer_attach(event, NULL);
4970 mutex_unlock(&event->mmap_mutex);
4972 /* If there's still other mmap()s of this buffer, we're done. */
4973 if (atomic_read(&rb->mmap_count))
4977 * No other mmap()s, detach from all other events that might redirect
4978 * into the now unreachable buffer. Somewhat complicated by the
4979 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4983 list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
4984 if (!atomic_long_inc_not_zero(&event->refcount)) {
4986 * This event is en-route to free_event() which will
4987 * detach it and remove it from the list.
4993 mutex_lock(&event->mmap_mutex);
4995 * Check we didn't race with perf_event_set_output() which can
4996 * swizzle the rb from under us while we were waiting to
4997 * acquire mmap_mutex.
4999 * If we find a different rb; ignore this event, a next
5000 * iteration will no longer find it on the list. We have to
5001 * still restart the iteration to make sure we're not now
5002 * iterating the wrong list.
5004 if (event->rb == rb)
5005 ring_buffer_attach(event, NULL);
5007 mutex_unlock(&event->mmap_mutex);
5011 * Restart the iteration; either we're on the wrong list or
5012 * destroyed its integrity by doing a deletion.
5019 * It could be there's still a few 0-ref events on the list; they'll
5020 * get cleaned up by free_event() -- they'll also still have their
5021 * ref on the rb and will free it whenever they are done with it.
5023 * Aside from that, this buffer is 'fully' detached and unmapped,
5024 * undo the VM accounting.
5027 atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm);
5028 vma->vm_mm->pinned_vm -= mmap_locked;
5029 free_uid(mmap_user);
5032 ring_buffer_put(rb); /* could be last */
5035 static const struct vm_operations_struct perf_mmap_vmops = {
5036 .open = perf_mmap_open,
5037 .close = perf_mmap_close, /* non mergable */
5038 .fault = perf_mmap_fault,
5039 .page_mkwrite = perf_mmap_fault,
5042 static int perf_mmap(struct file *file, struct vm_area_struct *vma)
5044 struct perf_event *event = file->private_data;
5045 unsigned long user_locked, user_lock_limit;
5046 struct user_struct *user = current_user();
5047 unsigned long locked, lock_limit;
5048 struct ring_buffer *rb = NULL;
5049 unsigned long vma_size;
5050 unsigned long nr_pages;
5051 long user_extra = 0, extra = 0;
5052 int ret = 0, flags = 0;
5055 * Don't allow mmap() of inherited per-task counters. This would
5056 * create a performance issue due to all children writing to the
5059 if (event->cpu == -1 && event->attr.inherit)
5062 if (!(vma->vm_flags & VM_SHARED))
5065 vma_size = vma->vm_end - vma->vm_start;
5067 if (vma->vm_pgoff == 0) {
5068 nr_pages = (vma_size / PAGE_SIZE) - 1;
5071 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5072 * mapped, all subsequent mappings should have the same size
5073 * and offset. Must be above the normal perf buffer.
5075 u64 aux_offset, aux_size;
5080 nr_pages = vma_size / PAGE_SIZE;
5082 mutex_lock(&event->mmap_mutex);
5089 aux_offset = ACCESS_ONCE(rb->user_page->aux_offset);
5090 aux_size = ACCESS_ONCE(rb->user_page->aux_size);
5092 if (aux_offset < perf_data_size(rb) + PAGE_SIZE)
5095 if (aux_offset != vma->vm_pgoff << PAGE_SHIFT)
5098 /* already mapped with a different offset */
5099 if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff)
5102 if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE)
5105 /* already mapped with a different size */
5106 if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages)
5109 if (!is_power_of_2(nr_pages))
5112 if (!atomic_inc_not_zero(&rb->mmap_count))
5115 if (rb_has_aux(rb)) {
5116 atomic_inc(&rb->aux_mmap_count);
5121 atomic_set(&rb->aux_mmap_count, 1);
5122 user_extra = nr_pages;
5128 * If we have rb pages ensure they're a power-of-two number, so we
5129 * can do bitmasks instead of modulo.
5131 if (nr_pages != 0 && !is_power_of_2(nr_pages))
5134 if (vma_size != PAGE_SIZE * (1 + nr_pages))
5137 WARN_ON_ONCE(event->ctx->parent_ctx);
5139 mutex_lock(&event->mmap_mutex);
5141 if (event->rb->nr_pages != nr_pages) {
5146 if (!atomic_inc_not_zero(&event->rb->mmap_count)) {
5148 * Raced against perf_mmap_close() through
5149 * perf_event_set_output(). Try again, hope for better
5152 mutex_unlock(&event->mmap_mutex);
5159 user_extra = nr_pages + 1;
5162 user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
5165 * Increase the limit linearly with more CPUs:
5167 user_lock_limit *= num_online_cpus();
5169 user_locked = atomic_long_read(&user->locked_vm) + user_extra;
5171 if (user_locked > user_lock_limit)
5172 extra = user_locked - user_lock_limit;
5174 lock_limit = rlimit(RLIMIT_MEMLOCK);
5175 lock_limit >>= PAGE_SHIFT;
5176 locked = vma->vm_mm->pinned_vm + extra;
5178 if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
5179 !capable(CAP_IPC_LOCK)) {
5184 WARN_ON(!rb && event->rb);
5186 if (vma->vm_flags & VM_WRITE)
5187 flags |= RING_BUFFER_WRITABLE;
5190 rb = rb_alloc(nr_pages,
5191 event->attr.watermark ? event->attr.wakeup_watermark : 0,
5199 atomic_set(&rb->mmap_count, 1);
5200 rb->mmap_user = get_current_user();
5201 rb->mmap_locked = extra;
5203 ring_buffer_attach(event, rb);
5205 perf_event_init_userpage(event);
5206 perf_event_update_userpage(event);
5208 ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages,
5209 event->attr.aux_watermark, flags);
5211 rb->aux_mmap_locked = extra;
5216 atomic_long_add(user_extra, &user->locked_vm);
5217 vma->vm_mm->pinned_vm += extra;
5219 atomic_inc(&event->mmap_count);
5221 atomic_dec(&rb->mmap_count);
5224 mutex_unlock(&event->mmap_mutex);
5227 * Since pinned accounting is per vm we cannot allow fork() to copy our
5230 vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP;
5231 vma->vm_ops = &perf_mmap_vmops;
5233 if (event->pmu->event_mapped)
5234 event->pmu->event_mapped(event);
5239 static int perf_fasync(int fd, struct file *filp, int on)
5241 struct inode *inode = file_inode(filp);
5242 struct perf_event *event = filp->private_data;
5246 retval = fasync_helper(fd, filp, on, &event->fasync);
5247 inode_unlock(inode);
5255 static const struct file_operations perf_fops = {
5256 .llseek = no_llseek,
5257 .release = perf_release,
5260 .unlocked_ioctl = perf_ioctl,
5261 .compat_ioctl = perf_compat_ioctl,
5263 .fasync = perf_fasync,
5269 * If there's data, ensure we set the poll() state and publish everything
5270 * to user-space before waking everybody up.
5273 static inline struct fasync_struct **perf_event_fasync(struct perf_event *event)
5275 /* only the parent has fasync state */
5277 event = event->parent;
5278 return &event->fasync;
5281 void perf_event_wakeup(struct perf_event *event)
5283 ring_buffer_wakeup(event);
5285 if (event->pending_kill) {
5286 kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill);
5287 event->pending_kill = 0;
5291 static void perf_pending_event(struct irq_work *entry)
5293 struct perf_event *event = container_of(entry,
5294 struct perf_event, pending);
5297 rctx = perf_swevent_get_recursion_context();
5299 * If we 'fail' here, that's OK, it means recursion is already disabled
5300 * and we won't recurse 'further'.
5303 if (event->pending_disable) {
5304 event->pending_disable = 0;
5305 perf_event_disable_local(event);
5308 if (event->pending_wakeup) {
5309 event->pending_wakeup = 0;
5310 perf_event_wakeup(event);
5314 perf_swevent_put_recursion_context(rctx);
5318 * We assume there is only KVM supporting the callbacks.
5319 * Later on, we might change it to a list if there is
5320 * another virtualization implementation supporting the callbacks.
5322 struct perf_guest_info_callbacks *perf_guest_cbs;
5324 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
5326 perf_guest_cbs = cbs;
5329 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
5331 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
5333 perf_guest_cbs = NULL;
5336 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
5339 perf_output_sample_regs(struct perf_output_handle *handle,
5340 struct pt_regs *regs, u64 mask)
5344 for_each_set_bit(bit, (const unsigned long *) &mask,
5345 sizeof(mask) * BITS_PER_BYTE) {
5348 val = perf_reg_value(regs, bit);
5349 perf_output_put(handle, val);
5353 static void perf_sample_regs_user(struct perf_regs *regs_user,
5354 struct pt_regs *regs,
5355 struct pt_regs *regs_user_copy)
5357 if (user_mode(regs)) {
5358 regs_user->abi = perf_reg_abi(current);
5359 regs_user->regs = regs;
5360 } else if (current->mm) {
5361 perf_get_regs_user(regs_user, regs, regs_user_copy);
5363 regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
5364 regs_user->regs = NULL;
5368 static void perf_sample_regs_intr(struct perf_regs *regs_intr,
5369 struct pt_regs *regs)
5371 regs_intr->regs = regs;
5372 regs_intr->abi = perf_reg_abi(current);
5377 * Get remaining task size from user stack pointer.
5379 * It'd be better to take stack vma map and limit this more
5380 * precisly, but there's no way to get it safely under interrupt,
5381 * so using TASK_SIZE as limit.
5383 static u64 perf_ustack_task_size(struct pt_regs *regs)
5385 unsigned long addr = perf_user_stack_pointer(regs);
5387 if (!addr || addr >= TASK_SIZE)
5390 return TASK_SIZE - addr;
5394 perf_sample_ustack_size(u16 stack_size, u16 header_size,
5395 struct pt_regs *regs)
5399 /* No regs, no stack pointer, no dump. */
5404 * Check if we fit in with the requested stack size into the:
5406 * If we don't, we limit the size to the TASK_SIZE.
5408 * - remaining sample size
5409 * If we don't, we customize the stack size to
5410 * fit in to the remaining sample size.
5413 task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs));
5414 stack_size = min(stack_size, (u16) task_size);
5416 /* Current header size plus static size and dynamic size. */
5417 header_size += 2 * sizeof(u64);
5419 /* Do we fit in with the current stack dump size? */
5420 if ((u16) (header_size + stack_size) < header_size) {
5422 * If we overflow the maximum size for the sample,
5423 * we customize the stack dump size to fit in.
5425 stack_size = USHRT_MAX - header_size - sizeof(u64);
5426 stack_size = round_up(stack_size, sizeof(u64));
5433 perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size,
5434 struct pt_regs *regs)
5436 /* Case of a kernel thread, nothing to dump */
5439 perf_output_put(handle, size);
5448 * - the size requested by user or the best one we can fit
5449 * in to the sample max size
5451 * - user stack dump data
5453 * - the actual dumped size
5457 perf_output_put(handle, dump_size);
5460 sp = perf_user_stack_pointer(regs);
5461 rem = __output_copy_user(handle, (void *) sp, dump_size);
5462 dyn_size = dump_size - rem;
5464 perf_output_skip(handle, rem);
5467 perf_output_put(handle, dyn_size);
5471 static void __perf_event_header__init_id(struct perf_event_header *header,
5472 struct perf_sample_data *data,
5473 struct perf_event *event)
5475 u64 sample_type = event->attr.sample_type;
5477 data->type = sample_type;
5478 header->size += event->id_header_size;
5480 if (sample_type & PERF_SAMPLE_TID) {
5481 /* namespace issues */
5482 data->tid_entry.pid = perf_event_pid(event, current);
5483 data->tid_entry.tid = perf_event_tid(event, current);
5486 if (sample_type & PERF_SAMPLE_TIME)
5487 data->time = perf_event_clock(event);
5489 if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER))
5490 data->id = primary_event_id(event);
5492 if (sample_type & PERF_SAMPLE_STREAM_ID)
5493 data->stream_id = event->id;
5495 if (sample_type & PERF_SAMPLE_CPU) {
5496 data->cpu_entry.cpu = raw_smp_processor_id();
5497 data->cpu_entry.reserved = 0;
5501 void perf_event_header__init_id(struct perf_event_header *header,
5502 struct perf_sample_data *data,
5503 struct perf_event *event)
5505 if (event->attr.sample_id_all)
5506 __perf_event_header__init_id(header, data, event);
5509 static void __perf_event__output_id_sample(struct perf_output_handle *handle,
5510 struct perf_sample_data *data)
5512 u64 sample_type = data->type;
5514 if (sample_type & PERF_SAMPLE_TID)
5515 perf_output_put(handle, data->tid_entry);
5517 if (sample_type & PERF_SAMPLE_TIME)
5518 perf_output_put(handle, data->time);
5520 if (sample_type & PERF_SAMPLE_ID)
5521 perf_output_put(handle, data->id);
5523 if (sample_type & PERF_SAMPLE_STREAM_ID)
5524 perf_output_put(handle, data->stream_id);
5526 if (sample_type & PERF_SAMPLE_CPU)
5527 perf_output_put(handle, data->cpu_entry);
5529 if (sample_type & PERF_SAMPLE_IDENTIFIER)
5530 perf_output_put(handle, data->id);
5533 void perf_event__output_id_sample(struct perf_event *event,
5534 struct perf_output_handle *handle,
5535 struct perf_sample_data *sample)
5537 if (event->attr.sample_id_all)
5538 __perf_event__output_id_sample(handle, sample);
5541 static void perf_output_read_one(struct perf_output_handle *handle,
5542 struct perf_event *event,
5543 u64 enabled, u64 running)
5545 u64 read_format = event->attr.read_format;
5549 values[n++] = perf_event_count(event);
5550 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
5551 values[n++] = enabled +
5552 atomic64_read(&event->child_total_time_enabled);
5554 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
5555 values[n++] = running +
5556 atomic64_read(&event->child_total_time_running);
5558 if (read_format & PERF_FORMAT_ID)
5559 values[n++] = primary_event_id(event);
5561 __output_copy(handle, values, n * sizeof(u64));
5565 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5567 static void perf_output_read_group(struct perf_output_handle *handle,
5568 struct perf_event *event,
5569 u64 enabled, u64 running)
5571 struct perf_event *leader = event->group_leader, *sub;
5572 u64 read_format = event->attr.read_format;
5576 values[n++] = 1 + leader->nr_siblings;
5578 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
5579 values[n++] = enabled;
5581 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
5582 values[n++] = running;
5584 if (leader != event)
5585 leader->pmu->read(leader);
5587 values[n++] = perf_event_count(leader);
5588 if (read_format & PERF_FORMAT_ID)
5589 values[n++] = primary_event_id(leader);
5591 __output_copy(handle, values, n * sizeof(u64));
5593 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
5596 if ((sub != event) &&
5597 (sub->state == PERF_EVENT_STATE_ACTIVE))
5598 sub->pmu->read(sub);
5600 values[n++] = perf_event_count(sub);
5601 if (read_format & PERF_FORMAT_ID)
5602 values[n++] = primary_event_id(sub);
5604 __output_copy(handle, values, n * sizeof(u64));
5608 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5609 PERF_FORMAT_TOTAL_TIME_RUNNING)
5611 static void perf_output_read(struct perf_output_handle *handle,
5612 struct perf_event *event)
5614 u64 enabled = 0, running = 0, now;
5615 u64 read_format = event->attr.read_format;
5618 * compute total_time_enabled, total_time_running
5619 * based on snapshot values taken when the event
5620 * was last scheduled in.
5622 * we cannot simply called update_context_time()
5623 * because of locking issue as we are called in
5626 if (read_format & PERF_FORMAT_TOTAL_TIMES)
5627 calc_timer_values(event, &now, &enabled, &running);
5629 if (event->attr.read_format & PERF_FORMAT_GROUP)
5630 perf_output_read_group(handle, event, enabled, running);
5632 perf_output_read_one(handle, event, enabled, running);
5635 void perf_output_sample(struct perf_output_handle *handle,
5636 struct perf_event_header *header,
5637 struct perf_sample_data *data,
5638 struct perf_event *event)
5640 u64 sample_type = data->type;
5642 perf_output_put(handle, *header);
5644 if (sample_type & PERF_SAMPLE_IDENTIFIER)
5645 perf_output_put(handle, data->id);
5647 if (sample_type & PERF_SAMPLE_IP)
5648 perf_output_put(handle, data->ip);
5650 if (sample_type & PERF_SAMPLE_TID)
5651 perf_output_put(handle, data->tid_entry);
5653 if (sample_type & PERF_SAMPLE_TIME)
5654 perf_output_put(handle, data->time);
5656 if (sample_type & PERF_SAMPLE_ADDR)
5657 perf_output_put(handle, data->addr);
5659 if (sample_type & PERF_SAMPLE_ID)
5660 perf_output_put(handle, data->id);
5662 if (sample_type & PERF_SAMPLE_STREAM_ID)
5663 perf_output_put(handle, data->stream_id);
5665 if (sample_type & PERF_SAMPLE_CPU)
5666 perf_output_put(handle, data->cpu_entry);
5668 if (sample_type & PERF_SAMPLE_PERIOD)
5669 perf_output_put(handle, data->period);
5671 if (sample_type & PERF_SAMPLE_READ)
5672 perf_output_read(handle, event);
5674 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
5675 if (data->callchain) {
5678 if (data->callchain)
5679 size += data->callchain->nr;
5681 size *= sizeof(u64);
5683 __output_copy(handle, data->callchain, size);
5686 perf_output_put(handle, nr);
5690 if (sample_type & PERF_SAMPLE_RAW) {
5691 struct perf_raw_record *raw = data->raw;
5694 struct perf_raw_frag *frag = &raw->frag;
5696 perf_output_put(handle, raw->size);
5699 __output_custom(handle, frag->copy,
5700 frag->data, frag->size);
5702 __output_copy(handle, frag->data,
5705 if (perf_raw_frag_last(frag))
5710 __output_skip(handle, NULL, frag->pad);
5716 .size = sizeof(u32),
5719 perf_output_put(handle, raw);
5723 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
5724 if (data->br_stack) {
5727 size = data->br_stack->nr
5728 * sizeof(struct perf_branch_entry);
5730 perf_output_put(handle, data->br_stack->nr);
5731 perf_output_copy(handle, data->br_stack->entries, size);
5734 * we always store at least the value of nr
5737 perf_output_put(handle, nr);
5741 if (sample_type & PERF_SAMPLE_REGS_USER) {
5742 u64 abi = data->regs_user.abi;
5745 * If there are no regs to dump, notice it through
5746 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5748 perf_output_put(handle, abi);
5751 u64 mask = event->attr.sample_regs_user;
5752 perf_output_sample_regs(handle,
5753 data->regs_user.regs,
5758 if (sample_type & PERF_SAMPLE_STACK_USER) {
5759 perf_output_sample_ustack(handle,
5760 data->stack_user_size,
5761 data->regs_user.regs);
5764 if (sample_type & PERF_SAMPLE_WEIGHT)
5765 perf_output_put(handle, data->weight);
5767 if (sample_type & PERF_SAMPLE_DATA_SRC)
5768 perf_output_put(handle, data->data_src.val);
5770 if (sample_type & PERF_SAMPLE_TRANSACTION)
5771 perf_output_put(handle, data->txn);
5773 if (sample_type & PERF_SAMPLE_REGS_INTR) {
5774 u64 abi = data->regs_intr.abi;
5776 * If there are no regs to dump, notice it through
5777 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5779 perf_output_put(handle, abi);
5782 u64 mask = event->attr.sample_regs_intr;
5784 perf_output_sample_regs(handle,
5785 data->regs_intr.regs,
5790 if (!event->attr.watermark) {
5791 int wakeup_events = event->attr.wakeup_events;
5793 if (wakeup_events) {
5794 struct ring_buffer *rb = handle->rb;
5795 int events = local_inc_return(&rb->events);
5797 if (events >= wakeup_events) {
5798 local_sub(wakeup_events, &rb->events);
5799 local_inc(&rb->wakeup);
5805 void perf_prepare_sample(struct perf_event_header *header,
5806 struct perf_sample_data *data,
5807 struct perf_event *event,
5808 struct pt_regs *regs)
5810 u64 sample_type = event->attr.sample_type;
5812 header->type = PERF_RECORD_SAMPLE;
5813 header->size = sizeof(*header) + event->header_size;
5816 header->misc |= perf_misc_flags(regs);
5818 __perf_event_header__init_id(header, data, event);
5820 if (sample_type & PERF_SAMPLE_IP)
5821 data->ip = perf_instruction_pointer(regs);
5823 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
5826 data->callchain = perf_callchain(event, regs);
5828 if (data->callchain)
5829 size += data->callchain->nr;
5831 header->size += size * sizeof(u64);
5834 if (sample_type & PERF_SAMPLE_RAW) {
5835 struct perf_raw_record *raw = data->raw;
5839 struct perf_raw_frag *frag = &raw->frag;
5844 if (perf_raw_frag_last(frag))
5849 size = round_up(sum + sizeof(u32), sizeof(u64));
5850 raw->size = size - sizeof(u32);
5851 frag->pad = raw->size - sum;
5856 header->size += size;
5859 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
5860 int size = sizeof(u64); /* nr */
5861 if (data->br_stack) {
5862 size += data->br_stack->nr
5863 * sizeof(struct perf_branch_entry);
5865 header->size += size;
5868 if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER))
5869 perf_sample_regs_user(&data->regs_user, regs,
5870 &data->regs_user_copy);
5872 if (sample_type & PERF_SAMPLE_REGS_USER) {
5873 /* regs dump ABI info */
5874 int size = sizeof(u64);
5876 if (data->regs_user.regs) {
5877 u64 mask = event->attr.sample_regs_user;
5878 size += hweight64(mask) * sizeof(u64);
5881 header->size += size;
5884 if (sample_type & PERF_SAMPLE_STACK_USER) {
5886 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5887 * processed as the last one or have additional check added
5888 * in case new sample type is added, because we could eat
5889 * up the rest of the sample size.
5891 u16 stack_size = event->attr.sample_stack_user;
5892 u16 size = sizeof(u64);
5894 stack_size = perf_sample_ustack_size(stack_size, header->size,
5895 data->regs_user.regs);
5898 * If there is something to dump, add space for the dump
5899 * itself and for the field that tells the dynamic size,
5900 * which is how many have been actually dumped.
5903 size += sizeof(u64) + stack_size;
5905 data->stack_user_size = stack_size;
5906 header->size += size;
5909 if (sample_type & PERF_SAMPLE_REGS_INTR) {
5910 /* regs dump ABI info */
5911 int size = sizeof(u64);
5913 perf_sample_regs_intr(&data->regs_intr, regs);
5915 if (data->regs_intr.regs) {
5916 u64 mask = event->attr.sample_regs_intr;
5918 size += hweight64(mask) * sizeof(u64);
5921 header->size += size;
5925 static void __always_inline
5926 __perf_event_output(struct perf_event *event,
5927 struct perf_sample_data *data,
5928 struct pt_regs *regs,
5929 int (*output_begin)(struct perf_output_handle *,
5930 struct perf_event *,
5933 struct perf_output_handle handle;
5934 struct perf_event_header header;
5936 /* protect the callchain buffers */
5939 perf_prepare_sample(&header, data, event, regs);
5941 if (output_begin(&handle, event, header.size))
5944 perf_output_sample(&handle, &header, data, event);
5946 perf_output_end(&handle);
5953 perf_event_output_forward(struct perf_event *event,
5954 struct perf_sample_data *data,
5955 struct pt_regs *regs)
5957 __perf_event_output(event, data, regs, perf_output_begin_forward);
5961 perf_event_output_backward(struct perf_event *event,
5962 struct perf_sample_data *data,
5963 struct pt_regs *regs)
5965 __perf_event_output(event, data, regs, perf_output_begin_backward);
5969 perf_event_output(struct perf_event *event,
5970 struct perf_sample_data *data,
5971 struct pt_regs *regs)
5973 __perf_event_output(event, data, regs, perf_output_begin);
5980 struct perf_read_event {
5981 struct perf_event_header header;
5988 perf_event_read_event(struct perf_event *event,
5989 struct task_struct *task)
5991 struct perf_output_handle handle;
5992 struct perf_sample_data sample;
5993 struct perf_read_event read_event = {
5995 .type = PERF_RECORD_READ,
5997 .size = sizeof(read_event) + event->read_size,
5999 .pid = perf_event_pid(event, task),
6000 .tid = perf_event_tid(event, task),
6004 perf_event_header__init_id(&read_event.header, &sample, event);
6005 ret = perf_output_begin(&handle, event, read_event.header.size);
6009 perf_output_put(&handle, read_event);
6010 perf_output_read(&handle, event);
6011 perf_event__output_id_sample(event, &handle, &sample);
6013 perf_output_end(&handle);
6016 typedef void (perf_iterate_f)(struct perf_event *event, void *data);
6019 perf_iterate_ctx(struct perf_event_context *ctx,
6020 perf_iterate_f output,
6021 void *data, bool all)
6023 struct perf_event *event;
6025 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
6027 if (event->state < PERF_EVENT_STATE_INACTIVE)
6029 if (!event_filter_match(event))
6033 output(event, data);
6037 static void perf_iterate_sb_cpu(perf_iterate_f output, void *data)
6039 struct pmu_event_list *pel = this_cpu_ptr(&pmu_sb_events);
6040 struct perf_event *event;
6042 list_for_each_entry_rcu(event, &pel->list, sb_list) {
6044 * Skip events that are not fully formed yet; ensure that
6045 * if we observe event->ctx, both event and ctx will be
6046 * complete enough. See perf_install_in_context().
6048 if (!smp_load_acquire(&event->ctx))
6051 if (event->state < PERF_EVENT_STATE_INACTIVE)
6053 if (!event_filter_match(event))
6055 output(event, data);
6060 * Iterate all events that need to receive side-band events.
6062 * For new callers; ensure that account_pmu_sb_event() includes
6063 * your event, otherwise it might not get delivered.
6066 perf_iterate_sb(perf_iterate_f output, void *data,
6067 struct perf_event_context *task_ctx)
6069 struct perf_event_context *ctx;
6076 * If we have task_ctx != NULL we only notify the task context itself.
6077 * The task_ctx is set only for EXIT events before releasing task
6081 perf_iterate_ctx(task_ctx, output, data, false);
6085 perf_iterate_sb_cpu(output, data);
6087 for_each_task_context_nr(ctxn) {
6088 ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
6090 perf_iterate_ctx(ctx, output, data, false);
6098 * Clear all file-based filters at exec, they'll have to be
6099 * re-instated when/if these objects are mmapped again.
6101 static void perf_event_addr_filters_exec(struct perf_event *event, void *data)
6103 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
6104 struct perf_addr_filter *filter;
6105 unsigned int restart = 0, count = 0;
6106 unsigned long flags;
6108 if (!has_addr_filter(event))
6111 raw_spin_lock_irqsave(&ifh->lock, flags);
6112 list_for_each_entry(filter, &ifh->list, entry) {
6113 if (filter->inode) {
6114 event->addr_filters_offs[count] = 0;
6122 event->addr_filters_gen++;
6123 raw_spin_unlock_irqrestore(&ifh->lock, flags);
6126 perf_event_restart(event);
6129 void perf_event_exec(void)
6131 struct perf_event_context *ctx;
6135 for_each_task_context_nr(ctxn) {
6136 ctx = current->perf_event_ctxp[ctxn];
6140 perf_event_enable_on_exec(ctxn);
6142 perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL,
6148 struct remote_output {
6149 struct ring_buffer *rb;
6153 static void __perf_event_output_stop(struct perf_event *event, void *data)
6155 struct perf_event *parent = event->parent;
6156 struct remote_output *ro = data;
6157 struct ring_buffer *rb = ro->rb;
6158 struct stop_event_data sd = {
6162 if (!has_aux(event))
6169 * In case of inheritance, it will be the parent that links to the
6170 * ring-buffer, but it will be the child that's actually using it:
6172 if (rcu_dereference(parent->rb) == rb)
6173 ro->err = __perf_event_stop(&sd);
6176 static int __perf_pmu_output_stop(void *info)
6178 struct perf_event *event = info;
6179 struct pmu *pmu = event->pmu;
6180 struct perf_cpu_context *cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
6181 struct remote_output ro = {
6186 perf_iterate_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro, false);
6187 if (cpuctx->task_ctx)
6188 perf_iterate_ctx(cpuctx->task_ctx, __perf_event_output_stop,
6195 static void perf_pmu_output_stop(struct perf_event *event)
6197 struct perf_event *iter;
6202 list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) {
6204 * For per-CPU events, we need to make sure that neither they
6205 * nor their children are running; for cpu==-1 events it's
6206 * sufficient to stop the event itself if it's active, since
6207 * it can't have children.
6211 cpu = READ_ONCE(iter->oncpu);
6216 err = cpu_function_call(cpu, __perf_pmu_output_stop, event);
6217 if (err == -EAGAIN) {
6226 * task tracking -- fork/exit
6228 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6231 struct perf_task_event {
6232 struct task_struct *task;
6233 struct perf_event_context *task_ctx;
6236 struct perf_event_header header;
6246 static int perf_event_task_match(struct perf_event *event)
6248 return event->attr.comm || event->attr.mmap ||
6249 event->attr.mmap2 || event->attr.mmap_data ||
6253 static void perf_event_task_output(struct perf_event *event,
6256 struct perf_task_event *task_event = data;
6257 struct perf_output_handle handle;
6258 struct perf_sample_data sample;
6259 struct task_struct *task = task_event->task;
6260 int ret, size = task_event->event_id.header.size;
6262 if (!perf_event_task_match(event))
6265 perf_event_header__init_id(&task_event->event_id.header, &sample, event);
6267 ret = perf_output_begin(&handle, event,
6268 task_event->event_id.header.size);
6272 task_event->event_id.pid = perf_event_pid(event, task);
6273 task_event->event_id.ppid = perf_event_pid(event, current);
6275 task_event->event_id.tid = perf_event_tid(event, task);
6276 task_event->event_id.ptid = perf_event_tid(event, current);
6278 task_event->event_id.time = perf_event_clock(event);
6280 perf_output_put(&handle, task_event->event_id);
6282 perf_event__output_id_sample(event, &handle, &sample);
6284 perf_output_end(&handle);
6286 task_event->event_id.header.size = size;
6289 static void perf_event_task(struct task_struct *task,
6290 struct perf_event_context *task_ctx,
6293 struct perf_task_event task_event;
6295 if (!atomic_read(&nr_comm_events) &&
6296 !atomic_read(&nr_mmap_events) &&
6297 !atomic_read(&nr_task_events))
6300 task_event = (struct perf_task_event){
6302 .task_ctx = task_ctx,
6305 .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
6307 .size = sizeof(task_event.event_id),
6317 perf_iterate_sb(perf_event_task_output,
6322 void perf_event_fork(struct task_struct *task)
6324 perf_event_task(task, NULL, 1);
6331 struct perf_comm_event {
6332 struct task_struct *task;
6337 struct perf_event_header header;
6344 static int perf_event_comm_match(struct perf_event *event)
6346 return event->attr.comm;
6349 static void perf_event_comm_output(struct perf_event *event,
6352 struct perf_comm_event *comm_event = data;
6353 struct perf_output_handle handle;
6354 struct perf_sample_data sample;
6355 int size = comm_event->event_id.header.size;
6358 if (!perf_event_comm_match(event))
6361 perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
6362 ret = perf_output_begin(&handle, event,
6363 comm_event->event_id.header.size);
6368 comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
6369 comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
6371 perf_output_put(&handle, comm_event->event_id);
6372 __output_copy(&handle, comm_event->comm,
6373 comm_event->comm_size);
6375 perf_event__output_id_sample(event, &handle, &sample);
6377 perf_output_end(&handle);
6379 comm_event->event_id.header.size = size;
6382 static void perf_event_comm_event(struct perf_comm_event *comm_event)
6384 char comm[TASK_COMM_LEN];
6387 memset(comm, 0, sizeof(comm));
6388 strlcpy(comm, comm_event->task->comm, sizeof(comm));
6389 size = ALIGN(strlen(comm)+1, sizeof(u64));
6391 comm_event->comm = comm;
6392 comm_event->comm_size = size;
6394 comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
6396 perf_iterate_sb(perf_event_comm_output,
6401 void perf_event_comm(struct task_struct *task, bool exec)
6403 struct perf_comm_event comm_event;
6405 if (!atomic_read(&nr_comm_events))
6408 comm_event = (struct perf_comm_event){
6414 .type = PERF_RECORD_COMM,
6415 .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0,
6423 perf_event_comm_event(&comm_event);
6430 struct perf_mmap_event {
6431 struct vm_area_struct *vma;
6433 const char *file_name;
6441 struct perf_event_header header;
6451 static int perf_event_mmap_match(struct perf_event *event,
6454 struct perf_mmap_event *mmap_event = data;
6455 struct vm_area_struct *vma = mmap_event->vma;
6456 int executable = vma->vm_flags & VM_EXEC;
6458 return (!executable && event->attr.mmap_data) ||
6459 (executable && (event->attr.mmap || event->attr.mmap2));
6462 static void perf_event_mmap_output(struct perf_event *event,
6465 struct perf_mmap_event *mmap_event = data;
6466 struct perf_output_handle handle;
6467 struct perf_sample_data sample;
6468 int size = mmap_event->event_id.header.size;
6471 if (!perf_event_mmap_match(event, data))
6474 if (event->attr.mmap2) {
6475 mmap_event->event_id.header.type = PERF_RECORD_MMAP2;
6476 mmap_event->event_id.header.size += sizeof(mmap_event->maj);
6477 mmap_event->event_id.header.size += sizeof(mmap_event->min);
6478 mmap_event->event_id.header.size += sizeof(mmap_event->ino);
6479 mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation);
6480 mmap_event->event_id.header.size += sizeof(mmap_event->prot);
6481 mmap_event->event_id.header.size += sizeof(mmap_event->flags);
6484 perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
6485 ret = perf_output_begin(&handle, event,
6486 mmap_event->event_id.header.size);
6490 mmap_event->event_id.pid = perf_event_pid(event, current);
6491 mmap_event->event_id.tid = perf_event_tid(event, current);
6493 perf_output_put(&handle, mmap_event->event_id);
6495 if (event->attr.mmap2) {
6496 perf_output_put(&handle, mmap_event->maj);
6497 perf_output_put(&handle, mmap_event->min);
6498 perf_output_put(&handle, mmap_event->ino);
6499 perf_output_put(&handle, mmap_event->ino_generation);
6500 perf_output_put(&handle, mmap_event->prot);
6501 perf_output_put(&handle, mmap_event->flags);
6504 __output_copy(&handle, mmap_event->file_name,
6505 mmap_event->file_size);
6507 perf_event__output_id_sample(event, &handle, &sample);
6509 perf_output_end(&handle);
6511 mmap_event->event_id.header.size = size;
6514 static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
6516 struct vm_area_struct *vma = mmap_event->vma;
6517 struct file *file = vma->vm_file;
6518 int maj = 0, min = 0;
6519 u64 ino = 0, gen = 0;
6520 u32 prot = 0, flags = 0;
6527 struct inode *inode;
6530 buf = kmalloc(PATH_MAX, GFP_KERNEL);
6536 * d_path() works from the end of the rb backwards, so we
6537 * need to add enough zero bytes after the string to handle
6538 * the 64bit alignment we do later.
6540 name = file_path(file, buf, PATH_MAX - sizeof(u64));
6545 inode = file_inode(vma->vm_file);
6546 dev = inode->i_sb->s_dev;
6548 gen = inode->i_generation;
6552 if (vma->vm_flags & VM_READ)
6554 if (vma->vm_flags & VM_WRITE)
6556 if (vma->vm_flags & VM_EXEC)
6559 if (vma->vm_flags & VM_MAYSHARE)
6562 flags = MAP_PRIVATE;
6564 if (vma->vm_flags & VM_DENYWRITE)
6565 flags |= MAP_DENYWRITE;
6566 if (vma->vm_flags & VM_MAYEXEC)
6567 flags |= MAP_EXECUTABLE;
6568 if (vma->vm_flags & VM_LOCKED)
6569 flags |= MAP_LOCKED;
6570 if (vma->vm_flags & VM_HUGETLB)
6571 flags |= MAP_HUGETLB;
6575 if (vma->vm_ops && vma->vm_ops->name) {
6576 name = (char *) vma->vm_ops->name(vma);
6581 name = (char *)arch_vma_name(vma);
6585 if (vma->vm_start <= vma->vm_mm->start_brk &&
6586 vma->vm_end >= vma->vm_mm->brk) {
6590 if (vma->vm_start <= vma->vm_mm->start_stack &&
6591 vma->vm_end >= vma->vm_mm->start_stack) {
6601 strlcpy(tmp, name, sizeof(tmp));
6605 * Since our buffer works in 8 byte units we need to align our string
6606 * size to a multiple of 8. However, we must guarantee the tail end is
6607 * zero'd out to avoid leaking random bits to userspace.
6609 size = strlen(name)+1;
6610 while (!IS_ALIGNED(size, sizeof(u64)))
6611 name[size++] = '\0';
6613 mmap_event->file_name = name;
6614 mmap_event->file_size = size;
6615 mmap_event->maj = maj;
6616 mmap_event->min = min;
6617 mmap_event->ino = ino;
6618 mmap_event->ino_generation = gen;
6619 mmap_event->prot = prot;
6620 mmap_event->flags = flags;
6622 if (!(vma->vm_flags & VM_EXEC))
6623 mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;
6625 mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
6627 perf_iterate_sb(perf_event_mmap_output,
6635 * Check whether inode and address range match filter criteria.
6637 static bool perf_addr_filter_match(struct perf_addr_filter *filter,
6638 struct file *file, unsigned long offset,
6641 if (filter->inode != file->f_inode)
6644 if (filter->offset > offset + size)
6647 if (filter->offset + filter->size < offset)
6653 static void __perf_addr_filters_adjust(struct perf_event *event, void *data)
6655 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
6656 struct vm_area_struct *vma = data;
6657 unsigned long off = vma->vm_pgoff << PAGE_SHIFT, flags;
6658 struct file *file = vma->vm_file;
6659 struct perf_addr_filter *filter;
6660 unsigned int restart = 0, count = 0;
6662 if (!has_addr_filter(event))
6668 raw_spin_lock_irqsave(&ifh->lock, flags);
6669 list_for_each_entry(filter, &ifh->list, entry) {
6670 if (perf_addr_filter_match(filter, file, off,
6671 vma->vm_end - vma->vm_start)) {
6672 event->addr_filters_offs[count] = vma->vm_start;
6680 event->addr_filters_gen++;
6681 raw_spin_unlock_irqrestore(&ifh->lock, flags);
6684 perf_event_restart(event);
6688 * Adjust all task's events' filters to the new vma
6690 static void perf_addr_filters_adjust(struct vm_area_struct *vma)
6692 struct perf_event_context *ctx;
6696 * Data tracing isn't supported yet and as such there is no need
6697 * to keep track of anything that isn't related to executable code:
6699 if (!(vma->vm_flags & VM_EXEC))
6703 for_each_task_context_nr(ctxn) {
6704 ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
6708 perf_iterate_ctx(ctx, __perf_addr_filters_adjust, vma, true);
6713 void perf_event_mmap(struct vm_area_struct *vma)
6715 struct perf_mmap_event mmap_event;
6717 if (!atomic_read(&nr_mmap_events))
6720 mmap_event = (struct perf_mmap_event){
6726 .type = PERF_RECORD_MMAP,
6727 .misc = PERF_RECORD_MISC_USER,
6732 .start = vma->vm_start,
6733 .len = vma->vm_end - vma->vm_start,
6734 .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT,
6736 /* .maj (attr_mmap2 only) */
6737 /* .min (attr_mmap2 only) */
6738 /* .ino (attr_mmap2 only) */
6739 /* .ino_generation (attr_mmap2 only) */
6740 /* .prot (attr_mmap2 only) */
6741 /* .flags (attr_mmap2 only) */
6744 perf_addr_filters_adjust(vma);
6745 perf_event_mmap_event(&mmap_event);
6748 void perf_event_aux_event(struct perf_event *event, unsigned long head,
6749 unsigned long size, u64 flags)
6751 struct perf_output_handle handle;
6752 struct perf_sample_data sample;
6753 struct perf_aux_event {
6754 struct perf_event_header header;
6760 .type = PERF_RECORD_AUX,
6762 .size = sizeof(rec),
6770 perf_event_header__init_id(&rec.header, &sample, event);
6771 ret = perf_output_begin(&handle, event, rec.header.size);
6776 perf_output_put(&handle, rec);
6777 perf_event__output_id_sample(event, &handle, &sample);
6779 perf_output_end(&handle);
6783 * Lost/dropped samples logging
6785 void perf_log_lost_samples(struct perf_event *event, u64 lost)
6787 struct perf_output_handle handle;
6788 struct perf_sample_data sample;
6792 struct perf_event_header header;
6794 } lost_samples_event = {
6796 .type = PERF_RECORD_LOST_SAMPLES,
6798 .size = sizeof(lost_samples_event),
6803 perf_event_header__init_id(&lost_samples_event.header, &sample, event);
6805 ret = perf_output_begin(&handle, event,
6806 lost_samples_event.header.size);
6810 perf_output_put(&handle, lost_samples_event);
6811 perf_event__output_id_sample(event, &handle, &sample);
6812 perf_output_end(&handle);
6816 * context_switch tracking
6819 struct perf_switch_event {
6820 struct task_struct *task;
6821 struct task_struct *next_prev;
6824 struct perf_event_header header;
6830 static int perf_event_switch_match(struct perf_event *event)
6832 return event->attr.context_switch;
6835 static void perf_event_switch_output(struct perf_event *event, void *data)
6837 struct perf_switch_event *se = data;
6838 struct perf_output_handle handle;
6839 struct perf_sample_data sample;
6842 if (!perf_event_switch_match(event))
6845 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6846 if (event->ctx->task) {
6847 se->event_id.header.type = PERF_RECORD_SWITCH;
6848 se->event_id.header.size = sizeof(se->event_id.header);
6850 se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE;
6851 se->event_id.header.size = sizeof(se->event_id);
6852 se->event_id.next_prev_pid =
6853 perf_event_pid(event, se->next_prev);
6854 se->event_id.next_prev_tid =
6855 perf_event_tid(event, se->next_prev);
6858 perf_event_header__init_id(&se->event_id.header, &sample, event);
6860 ret = perf_output_begin(&handle, event, se->event_id.header.size);
6864 if (event->ctx->task)
6865 perf_output_put(&handle, se->event_id.header);
6867 perf_output_put(&handle, se->event_id);
6869 perf_event__output_id_sample(event, &handle, &sample);
6871 perf_output_end(&handle);
6874 static void perf_event_switch(struct task_struct *task,
6875 struct task_struct *next_prev, bool sched_in)
6877 struct perf_switch_event switch_event;
6879 /* N.B. caller checks nr_switch_events != 0 */
6881 switch_event = (struct perf_switch_event){
6883 .next_prev = next_prev,
6887 .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT,
6890 /* .next_prev_pid */
6891 /* .next_prev_tid */
6895 perf_iterate_sb(perf_event_switch_output,
6901 * IRQ throttle logging
6904 static void perf_log_throttle(struct perf_event *event, int enable)
6906 struct perf_output_handle handle;
6907 struct perf_sample_data sample;
6911 struct perf_event_header header;
6915 } throttle_event = {
6917 .type = PERF_RECORD_THROTTLE,
6919 .size = sizeof(throttle_event),
6921 .time = perf_event_clock(event),
6922 .id = primary_event_id(event),
6923 .stream_id = event->id,
6927 throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
6929 perf_event_header__init_id(&throttle_event.header, &sample, event);
6931 ret = perf_output_begin(&handle, event,
6932 throttle_event.header.size);
6936 perf_output_put(&handle, throttle_event);
6937 perf_event__output_id_sample(event, &handle, &sample);
6938 perf_output_end(&handle);
6941 static void perf_log_itrace_start(struct perf_event *event)
6943 struct perf_output_handle handle;
6944 struct perf_sample_data sample;
6945 struct perf_aux_event {
6946 struct perf_event_header header;
6953 event = event->parent;
6955 if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) ||
6956 event->hw.itrace_started)
6959 rec.header.type = PERF_RECORD_ITRACE_START;
6960 rec.header.misc = 0;
6961 rec.header.size = sizeof(rec);
6962 rec.pid = perf_event_pid(event, current);
6963 rec.tid = perf_event_tid(event, current);
6965 perf_event_header__init_id(&rec.header, &sample, event);
6966 ret = perf_output_begin(&handle, event, rec.header.size);
6971 perf_output_put(&handle, rec);
6972 perf_event__output_id_sample(event, &handle, &sample);
6974 perf_output_end(&handle);
6978 * Generic event overflow handling, sampling.
6981 static int __perf_event_overflow(struct perf_event *event,
6982 int throttle, struct perf_sample_data *data,
6983 struct pt_regs *regs)
6985 int events = atomic_read(&event->event_limit);
6986 struct hw_perf_event *hwc = &event->hw;
6991 * Non-sampling counters might still use the PMI to fold short
6992 * hardware counters, ignore those.
6994 if (unlikely(!is_sampling_event(event)))
6997 seq = __this_cpu_read(perf_throttled_seq);
6998 if (seq != hwc->interrupts_seq) {
6999 hwc->interrupts_seq = seq;
7000 hwc->interrupts = 1;
7003 if (unlikely(throttle
7004 && hwc->interrupts >= max_samples_per_tick)) {
7005 __this_cpu_inc(perf_throttled_count);
7006 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS);
7007 hwc->interrupts = MAX_INTERRUPTS;
7008 perf_log_throttle(event, 0);
7013 if (event->attr.freq) {
7014 u64 now = perf_clock();
7015 s64 delta = now - hwc->freq_time_stamp;
7017 hwc->freq_time_stamp = now;
7019 if (delta > 0 && delta < 2*TICK_NSEC)
7020 perf_adjust_period(event, delta, hwc->last_period, true);
7024 * XXX event_limit might not quite work as expected on inherited
7028 event->pending_kill = POLL_IN;
7029 if (events && atomic_dec_and_test(&event->event_limit)) {
7031 event->pending_kill = POLL_HUP;
7032 event->pending_disable = 1;
7033 irq_work_queue(&event->pending);
7036 event->overflow_handler(event, data, regs);
7038 if (*perf_event_fasync(event) && event->pending_kill) {
7039 event->pending_wakeup = 1;
7040 irq_work_queue(&event->pending);
7046 int perf_event_overflow(struct perf_event *event,
7047 struct perf_sample_data *data,
7048 struct pt_regs *regs)
7050 return __perf_event_overflow(event, 1, data, regs);
7054 * Generic software event infrastructure
7057 struct swevent_htable {
7058 struct swevent_hlist *swevent_hlist;
7059 struct mutex hlist_mutex;
7062 /* Recursion avoidance in each contexts */
7063 int recursion[PERF_NR_CONTEXTS];
7066 static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
7069 * We directly increment event->count and keep a second value in
7070 * event->hw.period_left to count intervals. This period event
7071 * is kept in the range [-sample_period, 0] so that we can use the
7075 u64 perf_swevent_set_period(struct perf_event *event)
7077 struct hw_perf_event *hwc = &event->hw;
7078 u64 period = hwc->last_period;
7082 hwc->last_period = hwc->sample_period;
7085 old = val = local64_read(&hwc->period_left);
7089 nr = div64_u64(period + val, period);
7090 offset = nr * period;
7092 if (local64_cmpxchg(&hwc->period_left, old, val) != old)
7098 static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
7099 struct perf_sample_data *data,
7100 struct pt_regs *regs)
7102 struct hw_perf_event *hwc = &event->hw;
7106 overflow = perf_swevent_set_period(event);
7108 if (hwc->interrupts == MAX_INTERRUPTS)
7111 for (; overflow; overflow--) {
7112 if (__perf_event_overflow(event, throttle,
7115 * We inhibit the overflow from happening when
7116 * hwc->interrupts == MAX_INTERRUPTS.
7124 static void perf_swevent_event(struct perf_event *event, u64 nr,
7125 struct perf_sample_data *data,
7126 struct pt_regs *regs)
7128 struct hw_perf_event *hwc = &event->hw;
7130 local64_add(nr, &event->count);
7135 if (!is_sampling_event(event))
7138 if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) {
7140 return perf_swevent_overflow(event, 1, data, regs);
7142 data->period = event->hw.last_period;
7144 if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
7145 return perf_swevent_overflow(event, 1, data, regs);
7147 if (local64_add_negative(nr, &hwc->period_left))
7150 perf_swevent_overflow(event, 0, data, regs);
7153 static int perf_exclude_event(struct perf_event *event,
7154 struct pt_regs *regs)
7156 if (event->hw.state & PERF_HES_STOPPED)
7160 if (event->attr.exclude_user && user_mode(regs))
7163 if (event->attr.exclude_kernel && !user_mode(regs))
7170 static int perf_swevent_match(struct perf_event *event,
7171 enum perf_type_id type,
7173 struct perf_sample_data *data,
7174 struct pt_regs *regs)
7176 if (event->attr.type != type)
7179 if (event->attr.config != event_id)
7182 if (perf_exclude_event(event, regs))
7188 static inline u64 swevent_hash(u64 type, u32 event_id)
7190 u64 val = event_id | (type << 32);
7192 return hash_64(val, SWEVENT_HLIST_BITS);
7195 static inline struct hlist_head *
7196 __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id)
7198 u64 hash = swevent_hash(type, event_id);
7200 return &hlist->heads[hash];
7203 /* For the read side: events when they trigger */
7204 static inline struct hlist_head *
7205 find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id)
7207 struct swevent_hlist *hlist;
7209 hlist = rcu_dereference(swhash->swevent_hlist);
7213 return __find_swevent_head(hlist, type, event_id);
7216 /* For the event head insertion and removal in the hlist */
7217 static inline struct hlist_head *
7218 find_swevent_head(struct swevent_htable *swhash, struct perf_event *event)
7220 struct swevent_hlist *hlist;
7221 u32 event_id = event->attr.config;
7222 u64 type = event->attr.type;
7225 * Event scheduling is always serialized against hlist allocation
7226 * and release. Which makes the protected version suitable here.
7227 * The context lock guarantees that.
7229 hlist = rcu_dereference_protected(swhash->swevent_hlist,
7230 lockdep_is_held(&event->ctx->lock));
7234 return __find_swevent_head(hlist, type, event_id);
7237 static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
7239 struct perf_sample_data *data,
7240 struct pt_regs *regs)
7242 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7243 struct perf_event *event;
7244 struct hlist_head *head;
7247 head = find_swevent_head_rcu(swhash, type, event_id);
7251 hlist_for_each_entry_rcu(event, head, hlist_entry) {
7252 if (perf_swevent_match(event, type, event_id, data, regs))
7253 perf_swevent_event(event, nr, data, regs);
7259 DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]);
7261 int perf_swevent_get_recursion_context(void)
7263 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7265 return get_recursion_context(swhash->recursion);
7267 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
7269 void perf_swevent_put_recursion_context(int rctx)
7271 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7273 put_recursion_context(swhash->recursion, rctx);
7276 void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
7278 struct perf_sample_data data;
7280 if (WARN_ON_ONCE(!regs))
7283 perf_sample_data_init(&data, addr, 0);
7284 do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);
7287 void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
7291 preempt_disable_notrace();
7292 rctx = perf_swevent_get_recursion_context();
7293 if (unlikely(rctx < 0))
7296 ___perf_sw_event(event_id, nr, regs, addr);
7298 perf_swevent_put_recursion_context(rctx);
7300 preempt_enable_notrace();
7303 static void perf_swevent_read(struct perf_event *event)
7307 static int perf_swevent_add(struct perf_event *event, int flags)
7309 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
7310 struct hw_perf_event *hwc = &event->hw;
7311 struct hlist_head *head;
7313 if (is_sampling_event(event)) {
7314 hwc->last_period = hwc->sample_period;
7315 perf_swevent_set_period(event);
7318 hwc->state = !(flags & PERF_EF_START);
7320 head = find_swevent_head(swhash, event);
7321 if (WARN_ON_ONCE(!head))
7324 hlist_add_head_rcu(&event->hlist_entry, head);
7325 perf_event_update_userpage(event);
7330 static void perf_swevent_del(struct perf_event *event, int flags)
7332 hlist_del_rcu(&event->hlist_entry);
7335 static void perf_swevent_start(struct perf_event *event, int flags)
7337 event->hw.state = 0;
7340 static void perf_swevent_stop(struct perf_event *event, int flags)
7342 event->hw.state = PERF_HES_STOPPED;
7345 /* Deref the hlist from the update side */
7346 static inline struct swevent_hlist *
7347 swevent_hlist_deref(struct swevent_htable *swhash)
7349 return rcu_dereference_protected(swhash->swevent_hlist,
7350 lockdep_is_held(&swhash->hlist_mutex));
7353 static void swevent_hlist_release(struct swevent_htable *swhash)
7355 struct swevent_hlist *hlist = swevent_hlist_deref(swhash);
7360 RCU_INIT_POINTER(swhash->swevent_hlist, NULL);
7361 kfree_rcu(hlist, rcu_head);
7364 static void swevent_hlist_put_cpu(int cpu)
7366 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
7368 mutex_lock(&swhash->hlist_mutex);
7370 if (!--swhash->hlist_refcount)
7371 swevent_hlist_release(swhash);
7373 mutex_unlock(&swhash->hlist_mutex);
7376 static void swevent_hlist_put(void)
7380 for_each_possible_cpu(cpu)
7381 swevent_hlist_put_cpu(cpu);
7384 static int swevent_hlist_get_cpu(int cpu)
7386 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
7389 mutex_lock(&swhash->hlist_mutex);
7390 if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) {
7391 struct swevent_hlist *hlist;
7393 hlist = kzalloc(sizeof(*hlist), GFP_KERNEL);
7398 rcu_assign_pointer(swhash->swevent_hlist, hlist);
7400 swhash->hlist_refcount++;
7402 mutex_unlock(&swhash->hlist_mutex);
7407 static int swevent_hlist_get(void)
7409 int err, cpu, failed_cpu;
7412 for_each_possible_cpu(cpu) {
7413 err = swevent_hlist_get_cpu(cpu);
7423 for_each_possible_cpu(cpu) {
7424 if (cpu == failed_cpu)
7426 swevent_hlist_put_cpu(cpu);
7433 struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
7435 static void sw_perf_event_destroy(struct perf_event *event)
7437 u64 event_id = event->attr.config;
7439 WARN_ON(event->parent);
7441 static_key_slow_dec(&perf_swevent_enabled[event_id]);
7442 swevent_hlist_put();
7445 static int perf_swevent_init(struct perf_event *event)
7447 u64 event_id = event->attr.config;
7449 if (event->attr.type != PERF_TYPE_SOFTWARE)
7453 * no branch sampling for software events
7455 if (has_branch_stack(event))
7459 case PERF_COUNT_SW_CPU_CLOCK:
7460 case PERF_COUNT_SW_TASK_CLOCK:
7467 if (event_id >= PERF_COUNT_SW_MAX)
7470 if (!event->parent) {
7473 err = swevent_hlist_get();
7477 static_key_slow_inc(&perf_swevent_enabled[event_id]);
7478 event->destroy = sw_perf_event_destroy;
7484 static struct pmu perf_swevent = {
7485 .task_ctx_nr = perf_sw_context,
7487 .capabilities = PERF_PMU_CAP_NO_NMI,
7489 .event_init = perf_swevent_init,
7490 .add = perf_swevent_add,
7491 .del = perf_swevent_del,
7492 .start = perf_swevent_start,
7493 .stop = perf_swevent_stop,
7494 .read = perf_swevent_read,
7497 #ifdef CONFIG_EVENT_TRACING
7499 static int perf_tp_filter_match(struct perf_event *event,
7500 struct perf_sample_data *data)
7502 void *record = data->raw->frag.data;
7504 /* only top level events have filters set */
7506 event = event->parent;
7508 if (likely(!event->filter) || filter_match_preds(event->filter, record))
7513 static int perf_tp_event_match(struct perf_event *event,
7514 struct perf_sample_data *data,
7515 struct pt_regs *regs)
7517 if (event->hw.state & PERF_HES_STOPPED)
7520 * All tracepoints are from kernel-space.
7522 if (event->attr.exclude_kernel)
7525 if (!perf_tp_filter_match(event, data))
7531 void perf_trace_run_bpf_submit(void *raw_data, int size, int rctx,
7532 struct trace_event_call *call, u64 count,
7533 struct pt_regs *regs, struct hlist_head *head,
7534 struct task_struct *task)
7536 struct bpf_prog *prog = call->prog;
7539 *(struct pt_regs **)raw_data = regs;
7540 if (!trace_call_bpf(prog, raw_data) || hlist_empty(head)) {
7541 perf_swevent_put_recursion_context(rctx);
7545 perf_tp_event(call->event.type, count, raw_data, size, regs, head,
7548 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit);
7550 void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,
7551 struct pt_regs *regs, struct hlist_head *head, int rctx,
7552 struct task_struct *task)
7554 struct perf_sample_data data;
7555 struct perf_event *event;
7557 struct perf_raw_record raw = {
7564 perf_sample_data_init(&data, 0, 0);
7567 perf_trace_buf_update(record, event_type);
7569 hlist_for_each_entry_rcu(event, head, hlist_entry) {
7570 if (perf_tp_event_match(event, &data, regs))
7571 perf_swevent_event(event, count, &data, regs);
7575 * If we got specified a target task, also iterate its context and
7576 * deliver this event there too.
7578 if (task && task != current) {
7579 struct perf_event_context *ctx;
7580 struct trace_entry *entry = record;
7583 ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]);
7587 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
7588 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7590 if (event->attr.config != entry->type)
7592 if (perf_tp_event_match(event, &data, regs))
7593 perf_swevent_event(event, count, &data, regs);
7599 perf_swevent_put_recursion_context(rctx);
7601 EXPORT_SYMBOL_GPL(perf_tp_event);
7603 static void tp_perf_event_destroy(struct perf_event *event)
7605 perf_trace_destroy(event);
7608 static int perf_tp_event_init(struct perf_event *event)
7612 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7616 * no branch sampling for tracepoint events
7618 if (has_branch_stack(event))
7621 err = perf_trace_init(event);
7625 event->destroy = tp_perf_event_destroy;
7630 static struct pmu perf_tracepoint = {
7631 .task_ctx_nr = perf_sw_context,
7633 .event_init = perf_tp_event_init,
7634 .add = perf_trace_add,
7635 .del = perf_trace_del,
7636 .start = perf_swevent_start,
7637 .stop = perf_swevent_stop,
7638 .read = perf_swevent_read,
7641 static inline void perf_tp_register(void)
7643 perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
7646 static void perf_event_free_filter(struct perf_event *event)
7648 ftrace_profile_free_filter(event);
7651 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
7653 bool is_kprobe, is_tracepoint;
7654 struct bpf_prog *prog;
7656 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7659 if (event->tp_event->prog)
7662 is_kprobe = event->tp_event->flags & TRACE_EVENT_FL_UKPROBE;
7663 is_tracepoint = event->tp_event->flags & TRACE_EVENT_FL_TRACEPOINT;
7664 if (!is_kprobe && !is_tracepoint)
7665 /* bpf programs can only be attached to u/kprobe or tracepoint */
7668 prog = bpf_prog_get(prog_fd);
7670 return PTR_ERR(prog);
7672 if ((is_kprobe && prog->type != BPF_PROG_TYPE_KPROBE) ||
7673 (is_tracepoint && prog->type != BPF_PROG_TYPE_TRACEPOINT)) {
7674 /* valid fd, but invalid bpf program type */
7679 if (is_tracepoint) {
7680 int off = trace_event_get_offsets(event->tp_event);
7682 if (prog->aux->max_ctx_offset > off) {
7687 event->tp_event->prog = prog;
7692 static void perf_event_free_bpf_prog(struct perf_event *event)
7694 struct bpf_prog *prog;
7696 if (!event->tp_event)
7699 prog = event->tp_event->prog;
7701 event->tp_event->prog = NULL;
7708 static inline void perf_tp_register(void)
7712 static void perf_event_free_filter(struct perf_event *event)
7716 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
7721 static void perf_event_free_bpf_prog(struct perf_event *event)
7724 #endif /* CONFIG_EVENT_TRACING */
7726 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7727 void perf_bp_event(struct perf_event *bp, void *data)
7729 struct perf_sample_data sample;
7730 struct pt_regs *regs = data;
7732 perf_sample_data_init(&sample, bp->attr.bp_addr, 0);
7734 if (!bp->hw.state && !perf_exclude_event(bp, regs))
7735 perf_swevent_event(bp, 1, &sample, regs);
7740 * Allocate a new address filter
7742 static struct perf_addr_filter *
7743 perf_addr_filter_new(struct perf_event *event, struct list_head *filters)
7745 int node = cpu_to_node(event->cpu == -1 ? 0 : event->cpu);
7746 struct perf_addr_filter *filter;
7748 filter = kzalloc_node(sizeof(*filter), GFP_KERNEL, node);
7752 INIT_LIST_HEAD(&filter->entry);
7753 list_add_tail(&filter->entry, filters);
7758 static void free_filters_list(struct list_head *filters)
7760 struct perf_addr_filter *filter, *iter;
7762 list_for_each_entry_safe(filter, iter, filters, entry) {
7764 iput(filter->inode);
7765 list_del(&filter->entry);
7771 * Free existing address filters and optionally install new ones
7773 static void perf_addr_filters_splice(struct perf_event *event,
7774 struct list_head *head)
7776 unsigned long flags;
7779 if (!has_addr_filter(event))
7782 /* don't bother with children, they don't have their own filters */
7786 raw_spin_lock_irqsave(&event->addr_filters.lock, flags);
7788 list_splice_init(&event->addr_filters.list, &list);
7790 list_splice(head, &event->addr_filters.list);
7792 raw_spin_unlock_irqrestore(&event->addr_filters.lock, flags);
7794 free_filters_list(&list);
7798 * Scan through mm's vmas and see if one of them matches the
7799 * @filter; if so, adjust filter's address range.
7800 * Called with mm::mmap_sem down for reading.
7802 static unsigned long perf_addr_filter_apply(struct perf_addr_filter *filter,
7803 struct mm_struct *mm)
7805 struct vm_area_struct *vma;
7807 for (vma = mm->mmap; vma; vma = vma->vm_next) {
7808 struct file *file = vma->vm_file;
7809 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
7810 unsigned long vma_size = vma->vm_end - vma->vm_start;
7815 if (!perf_addr_filter_match(filter, file, off, vma_size))
7818 return vma->vm_start;
7825 * Update event's address range filters based on the
7826 * task's existing mappings, if any.
7828 static void perf_event_addr_filters_apply(struct perf_event *event)
7830 struct perf_addr_filters_head *ifh = perf_event_addr_filters(event);
7831 struct task_struct *task = READ_ONCE(event->ctx->task);
7832 struct perf_addr_filter *filter;
7833 struct mm_struct *mm = NULL;
7834 unsigned int count = 0;
7835 unsigned long flags;
7838 * We may observe TASK_TOMBSTONE, which means that the event tear-down
7839 * will stop on the parent's child_mutex that our caller is also holding
7841 if (task == TASK_TOMBSTONE)
7844 mm = get_task_mm(event->ctx->task);
7848 down_read(&mm->mmap_sem);
7850 raw_spin_lock_irqsave(&ifh->lock, flags);
7851 list_for_each_entry(filter, &ifh->list, entry) {
7852 event->addr_filters_offs[count] = 0;
7855 * Adjust base offset if the filter is associated to a binary
7856 * that needs to be mapped:
7859 event->addr_filters_offs[count] =
7860 perf_addr_filter_apply(filter, mm);
7865 event->addr_filters_gen++;
7866 raw_spin_unlock_irqrestore(&ifh->lock, flags);
7868 up_read(&mm->mmap_sem);
7873 perf_event_restart(event);
7877 * Address range filtering: limiting the data to certain
7878 * instruction address ranges. Filters are ioctl()ed to us from
7879 * userspace as ascii strings.
7881 * Filter string format:
7884 * where ACTION is one of the
7885 * * "filter": limit the trace to this region
7886 * * "start": start tracing from this address
7887 * * "stop": stop tracing at this address/region;
7889 * * for kernel addresses: <start address>[/<size>]
7890 * * for object files: <start address>[/<size>]@</path/to/object/file>
7892 * if <size> is not specified, the range is treated as a single address.
7905 IF_STATE_ACTION = 0,
7910 static const match_table_t if_tokens = {
7911 { IF_ACT_FILTER, "filter" },
7912 { IF_ACT_START, "start" },
7913 { IF_ACT_STOP, "stop" },
7914 { IF_SRC_FILE, "%u/%u@%s" },
7915 { IF_SRC_KERNEL, "%u/%u" },
7916 { IF_SRC_FILEADDR, "%u@%s" },
7917 { IF_SRC_KERNELADDR, "%u" },
7921 * Address filter string parser
7924 perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
7925 struct list_head *filters)
7927 struct perf_addr_filter *filter = NULL;
7928 char *start, *orig, *filename = NULL;
7930 substring_t args[MAX_OPT_ARGS];
7931 int state = IF_STATE_ACTION, token;
7932 unsigned int kernel = 0;
7935 orig = fstr = kstrdup(fstr, GFP_KERNEL);
7939 while ((start = strsep(&fstr, " ,\n")) != NULL) {
7945 /* filter definition begins */
7946 if (state == IF_STATE_ACTION) {
7947 filter = perf_addr_filter_new(event, filters);
7952 token = match_token(start, if_tokens, args);
7959 if (state != IF_STATE_ACTION)
7962 state = IF_STATE_SOURCE;
7965 case IF_SRC_KERNELADDR:
7969 case IF_SRC_FILEADDR:
7971 if (state != IF_STATE_SOURCE)
7974 if (token == IF_SRC_FILE || token == IF_SRC_KERNEL)
7978 ret = kstrtoul(args[0].from, 0, &filter->offset);
7982 if (filter->range) {
7984 ret = kstrtoul(args[1].from, 0, &filter->size);
7989 if (token == IF_SRC_FILE || token == IF_SRC_FILEADDR) {
7990 int fpos = filter->range ? 2 : 1;
7992 filename = match_strdup(&args[fpos]);
7999 state = IF_STATE_END;
8007 * Filter definition is fully parsed, validate and install it.
8008 * Make sure that it doesn't contradict itself or the event's
8011 if (state == IF_STATE_END) {
8012 if (kernel && event->attr.exclude_kernel)
8019 /* look up the path and grab its inode */
8020 ret = kern_path(filename, LOOKUP_FOLLOW, &path);
8022 goto fail_free_name;
8024 filter->inode = igrab(d_inode(path.dentry));
8030 if (!filter->inode ||
8031 !S_ISREG(filter->inode->i_mode))
8032 /* free_filters_list() will iput() */
8036 /* ready to consume more filters */
8037 state = IF_STATE_ACTION;
8042 if (state != IF_STATE_ACTION)
8052 free_filters_list(filters);
8059 perf_event_set_addr_filter(struct perf_event *event, char *filter_str)
8065 * Since this is called in perf_ioctl() path, we're already holding
8068 lockdep_assert_held(&event->ctx->mutex);
8070 if (WARN_ON_ONCE(event->parent))
8074 * For now, we only support filtering in per-task events; doing so
8075 * for CPU-wide events requires additional context switching trickery,
8076 * since same object code will be mapped at different virtual
8077 * addresses in different processes.
8079 if (!event->ctx->task)
8082 ret = perf_event_parse_addr_filter(event, filter_str, &filters);
8086 ret = event->pmu->addr_filters_validate(&filters);
8088 free_filters_list(&filters);
8092 /* remove existing filters, if any */
8093 perf_addr_filters_splice(event, &filters);
8095 /* install new filters */
8096 perf_event_for_each_child(event, perf_event_addr_filters_apply);
8101 static int perf_event_set_filter(struct perf_event *event, void __user *arg)
8106 if ((event->attr.type != PERF_TYPE_TRACEPOINT ||
8107 !IS_ENABLED(CONFIG_EVENT_TRACING)) &&
8108 !has_addr_filter(event))
8111 filter_str = strndup_user(arg, PAGE_SIZE);
8112 if (IS_ERR(filter_str))
8113 return PTR_ERR(filter_str);
8115 if (IS_ENABLED(CONFIG_EVENT_TRACING) &&
8116 event->attr.type == PERF_TYPE_TRACEPOINT)
8117 ret = ftrace_profile_set_filter(event, event->attr.config,
8119 else if (has_addr_filter(event))
8120 ret = perf_event_set_addr_filter(event, filter_str);
8127 * hrtimer based swevent callback
8130 static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
8132 enum hrtimer_restart ret = HRTIMER_RESTART;
8133 struct perf_sample_data data;
8134 struct pt_regs *regs;
8135 struct perf_event *event;
8138 event = container_of(hrtimer, struct perf_event, hw.hrtimer);
8140 if (event->state != PERF_EVENT_STATE_ACTIVE)
8141 return HRTIMER_NORESTART;
8143 event->pmu->read(event);
8145 perf_sample_data_init(&data, 0, event->hw.last_period);
8146 regs = get_irq_regs();
8148 if (regs && !perf_exclude_event(event, regs)) {
8149 if (!(event->attr.exclude_idle && is_idle_task(current)))
8150 if (__perf_event_overflow(event, 1, &data, regs))
8151 ret = HRTIMER_NORESTART;
8154 period = max_t(u64, 10000, event->hw.sample_period);
8155 hrtimer_forward_now(hrtimer, ns_to_ktime(period));
8160 static void perf_swevent_start_hrtimer(struct perf_event *event)
8162 struct hw_perf_event *hwc = &event->hw;
8165 if (!is_sampling_event(event))
8168 period = local64_read(&hwc->period_left);
8173 local64_set(&hwc->period_left, 0);
8175 period = max_t(u64, 10000, hwc->sample_period);
8177 hrtimer_start(&hwc->hrtimer, ns_to_ktime(period),
8178 HRTIMER_MODE_REL_PINNED);
8181 static void perf_swevent_cancel_hrtimer(struct perf_event *event)
8183 struct hw_perf_event *hwc = &event->hw;
8185 if (is_sampling_event(event)) {
8186 ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
8187 local64_set(&hwc->period_left, ktime_to_ns(remaining));
8189 hrtimer_cancel(&hwc->hrtimer);
8193 static void perf_swevent_init_hrtimer(struct perf_event *event)
8195 struct hw_perf_event *hwc = &event->hw;
8197 if (!is_sampling_event(event))
8200 hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
8201 hwc->hrtimer.function = perf_swevent_hrtimer;
8204 * Since hrtimers have a fixed rate, we can do a static freq->period
8205 * mapping and avoid the whole period adjust feedback stuff.
8207 if (event->attr.freq) {
8208 long freq = event->attr.sample_freq;
8210 event->attr.sample_period = NSEC_PER_SEC / freq;
8211 hwc->sample_period = event->attr.sample_period;
8212 local64_set(&hwc->period_left, hwc->sample_period);
8213 hwc->last_period = hwc->sample_period;
8214 event->attr.freq = 0;
8219 * Software event: cpu wall time clock
8222 static void cpu_clock_event_update(struct perf_event *event)
8227 now = local_clock();
8228 prev = local64_xchg(&event->hw.prev_count, now);
8229 local64_add(now - prev, &event->count);
8232 static void cpu_clock_event_start(struct perf_event *event, int flags)
8234 local64_set(&event->hw.prev_count, local_clock());
8235 perf_swevent_start_hrtimer(event);
8238 static void cpu_clock_event_stop(struct perf_event *event, int flags)
8240 perf_swevent_cancel_hrtimer(event);
8241 cpu_clock_event_update(event);
8244 static int cpu_clock_event_add(struct perf_event *event, int flags)
8246 if (flags & PERF_EF_START)
8247 cpu_clock_event_start(event, flags);
8248 perf_event_update_userpage(event);
8253 static void cpu_clock_event_del(struct perf_event *event, int flags)
8255 cpu_clock_event_stop(event, flags);
8258 static void cpu_clock_event_read(struct perf_event *event)
8260 cpu_clock_event_update(event);
8263 static int cpu_clock_event_init(struct perf_event *event)
8265 if (event->attr.type != PERF_TYPE_SOFTWARE)
8268 if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
8272 * no branch sampling for software events
8274 if (has_branch_stack(event))
8277 perf_swevent_init_hrtimer(event);
8282 static struct pmu perf_cpu_clock = {
8283 .task_ctx_nr = perf_sw_context,
8285 .capabilities = PERF_PMU_CAP_NO_NMI,
8287 .event_init = cpu_clock_event_init,
8288 .add = cpu_clock_event_add,
8289 .del = cpu_clock_event_del,
8290 .start = cpu_clock_event_start,
8291 .stop = cpu_clock_event_stop,
8292 .read = cpu_clock_event_read,
8296 * Software event: task time clock
8299 static void task_clock_event_update(struct perf_event *event, u64 now)
8304 prev = local64_xchg(&event->hw.prev_count, now);
8306 local64_add(delta, &event->count);
8309 static void task_clock_event_start(struct perf_event *event, int flags)
8311 local64_set(&event->hw.prev_count, event->ctx->time);
8312 perf_swevent_start_hrtimer(event);
8315 static void task_clock_event_stop(struct perf_event *event, int flags)
8317 perf_swevent_cancel_hrtimer(event);
8318 task_clock_event_update(event, event->ctx->time);
8321 static int task_clock_event_add(struct perf_event *event, int flags)
8323 if (flags & PERF_EF_START)
8324 task_clock_event_start(event, flags);
8325 perf_event_update_userpage(event);
8330 static void task_clock_event_del(struct perf_event *event, int flags)
8332 task_clock_event_stop(event, PERF_EF_UPDATE);
8335 static void task_clock_event_read(struct perf_event *event)
8337 u64 now = perf_clock();
8338 u64 delta = now - event->ctx->timestamp;
8339 u64 time = event->ctx->time + delta;
8341 task_clock_event_update(event, time);
8344 static int task_clock_event_init(struct perf_event *event)
8346 if (event->attr.type != PERF_TYPE_SOFTWARE)
8349 if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
8353 * no branch sampling for software events
8355 if (has_branch_stack(event))
8358 perf_swevent_init_hrtimer(event);
8363 static struct pmu perf_task_clock = {
8364 .task_ctx_nr = perf_sw_context,
8366 .capabilities = PERF_PMU_CAP_NO_NMI,
8368 .event_init = task_clock_event_init,
8369 .add = task_clock_event_add,
8370 .del = task_clock_event_del,
8371 .start = task_clock_event_start,
8372 .stop = task_clock_event_stop,
8373 .read = task_clock_event_read,
8376 static void perf_pmu_nop_void(struct pmu *pmu)
8380 static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags)
8384 static int perf_pmu_nop_int(struct pmu *pmu)
8389 static DEFINE_PER_CPU(unsigned int, nop_txn_flags);
8391 static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags)
8393 __this_cpu_write(nop_txn_flags, flags);
8395 if (flags & ~PERF_PMU_TXN_ADD)
8398 perf_pmu_disable(pmu);
8401 static int perf_pmu_commit_txn(struct pmu *pmu)
8403 unsigned int flags = __this_cpu_read(nop_txn_flags);
8405 __this_cpu_write(nop_txn_flags, 0);
8407 if (flags & ~PERF_PMU_TXN_ADD)
8410 perf_pmu_enable(pmu);
8414 static void perf_pmu_cancel_txn(struct pmu *pmu)
8416 unsigned int flags = __this_cpu_read(nop_txn_flags);
8418 __this_cpu_write(nop_txn_flags, 0);
8420 if (flags & ~PERF_PMU_TXN_ADD)
8423 perf_pmu_enable(pmu);
8426 static int perf_event_idx_default(struct perf_event *event)
8432 * Ensures all contexts with the same task_ctx_nr have the same
8433 * pmu_cpu_context too.
8435 static struct perf_cpu_context __percpu *find_pmu_context(int ctxn)
8442 list_for_each_entry(pmu, &pmus, entry) {
8443 if (pmu->task_ctx_nr == ctxn)
8444 return pmu->pmu_cpu_context;
8450 static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu)
8454 for_each_possible_cpu(cpu) {
8455 struct perf_cpu_context *cpuctx;
8457 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
8459 if (cpuctx->unique_pmu == old_pmu)
8460 cpuctx->unique_pmu = pmu;
8464 static void free_pmu_context(struct pmu *pmu)
8468 mutex_lock(&pmus_lock);
8470 * Like a real lame refcount.
8472 list_for_each_entry(i, &pmus, entry) {
8473 if (i->pmu_cpu_context == pmu->pmu_cpu_context) {
8474 update_pmu_context(i, pmu);
8479 free_percpu(pmu->pmu_cpu_context);
8481 mutex_unlock(&pmus_lock);
8485 * Let userspace know that this PMU supports address range filtering:
8487 static ssize_t nr_addr_filters_show(struct device *dev,
8488 struct device_attribute *attr,
8491 struct pmu *pmu = dev_get_drvdata(dev);
8493 return snprintf(page, PAGE_SIZE - 1, "%d\n", pmu->nr_addr_filters);
8495 DEVICE_ATTR_RO(nr_addr_filters);
8497 static struct idr pmu_idr;
8500 type_show(struct device *dev, struct device_attribute *attr, char *page)
8502 struct pmu *pmu = dev_get_drvdata(dev);
8504 return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type);
8506 static DEVICE_ATTR_RO(type);
8509 perf_event_mux_interval_ms_show(struct device *dev,
8510 struct device_attribute *attr,
8513 struct pmu *pmu = dev_get_drvdata(dev);
8515 return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms);
8518 static DEFINE_MUTEX(mux_interval_mutex);
8521 perf_event_mux_interval_ms_store(struct device *dev,
8522 struct device_attribute *attr,
8523 const char *buf, size_t count)
8525 struct pmu *pmu = dev_get_drvdata(dev);
8526 int timer, cpu, ret;
8528 ret = kstrtoint(buf, 0, &timer);
8535 /* same value, noting to do */
8536 if (timer == pmu->hrtimer_interval_ms)
8539 mutex_lock(&mux_interval_mutex);
8540 pmu->hrtimer_interval_ms = timer;
8542 /* update all cpuctx for this PMU */
8544 for_each_online_cpu(cpu) {
8545 struct perf_cpu_context *cpuctx;
8546 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
8547 cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
8549 cpu_function_call(cpu,
8550 (remote_function_f)perf_mux_hrtimer_restart, cpuctx);
8553 mutex_unlock(&mux_interval_mutex);
8557 static DEVICE_ATTR_RW(perf_event_mux_interval_ms);
8559 static struct attribute *pmu_dev_attrs[] = {
8560 &dev_attr_type.attr,
8561 &dev_attr_perf_event_mux_interval_ms.attr,
8564 ATTRIBUTE_GROUPS(pmu_dev);
8566 static int pmu_bus_running;
8567 static struct bus_type pmu_bus = {
8568 .name = "event_source",
8569 .dev_groups = pmu_dev_groups,
8572 static void pmu_dev_release(struct device *dev)
8577 static int pmu_dev_alloc(struct pmu *pmu)
8581 pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
8585 pmu->dev->groups = pmu->attr_groups;
8586 device_initialize(pmu->dev);
8587 ret = dev_set_name(pmu->dev, "%s", pmu->name);
8591 dev_set_drvdata(pmu->dev, pmu);
8592 pmu->dev->bus = &pmu_bus;
8593 pmu->dev->release = pmu_dev_release;
8594 ret = device_add(pmu->dev);
8598 /* For PMUs with address filters, throw in an extra attribute: */
8599 if (pmu->nr_addr_filters)
8600 ret = device_create_file(pmu->dev, &dev_attr_nr_addr_filters);
8609 device_del(pmu->dev);
8612 put_device(pmu->dev);
8616 static struct lock_class_key cpuctx_mutex;
8617 static struct lock_class_key cpuctx_lock;
8619 int perf_pmu_register(struct pmu *pmu, const char *name, int type)
8623 mutex_lock(&pmus_lock);
8625 pmu->pmu_disable_count = alloc_percpu(int);
8626 if (!pmu->pmu_disable_count)
8635 type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL);
8643 if (pmu_bus_running) {
8644 ret = pmu_dev_alloc(pmu);
8650 if (pmu->task_ctx_nr == perf_hw_context) {
8651 static int hw_context_taken = 0;
8654 * Other than systems with heterogeneous CPUs, it never makes
8655 * sense for two PMUs to share perf_hw_context. PMUs which are
8656 * uncore must use perf_invalid_context.
8658 if (WARN_ON_ONCE(hw_context_taken &&
8659 !(pmu->capabilities & PERF_PMU_CAP_HETEROGENEOUS_CPUS)))
8660 pmu->task_ctx_nr = perf_invalid_context;
8662 hw_context_taken = 1;
8665 pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr);
8666 if (pmu->pmu_cpu_context)
8667 goto got_cpu_context;
8670 pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context);
8671 if (!pmu->pmu_cpu_context)
8674 for_each_possible_cpu(cpu) {
8675 struct perf_cpu_context *cpuctx;
8677 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
8678 __perf_event_init_context(&cpuctx->ctx);
8679 lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
8680 lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
8681 cpuctx->ctx.pmu = pmu;
8683 __perf_mux_hrtimer_init(cpuctx, cpu);
8685 cpuctx->unique_pmu = pmu;
8689 if (!pmu->start_txn) {
8690 if (pmu->pmu_enable) {
8692 * If we have pmu_enable/pmu_disable calls, install
8693 * transaction stubs that use that to try and batch
8694 * hardware accesses.
8696 pmu->start_txn = perf_pmu_start_txn;
8697 pmu->commit_txn = perf_pmu_commit_txn;
8698 pmu->cancel_txn = perf_pmu_cancel_txn;
8700 pmu->start_txn = perf_pmu_nop_txn;
8701 pmu->commit_txn = perf_pmu_nop_int;
8702 pmu->cancel_txn = perf_pmu_nop_void;
8706 if (!pmu->pmu_enable) {
8707 pmu->pmu_enable = perf_pmu_nop_void;
8708 pmu->pmu_disable = perf_pmu_nop_void;
8711 if (!pmu->event_idx)
8712 pmu->event_idx = perf_event_idx_default;
8714 list_add_rcu(&pmu->entry, &pmus);
8715 atomic_set(&pmu->exclusive_cnt, 0);
8718 mutex_unlock(&pmus_lock);
8723 device_del(pmu->dev);
8724 put_device(pmu->dev);
8727 if (pmu->type >= PERF_TYPE_MAX)
8728 idr_remove(&pmu_idr, pmu->type);
8731 free_percpu(pmu->pmu_disable_count);
8734 EXPORT_SYMBOL_GPL(perf_pmu_register);
8736 void perf_pmu_unregister(struct pmu *pmu)
8738 mutex_lock(&pmus_lock);
8739 list_del_rcu(&pmu->entry);
8740 mutex_unlock(&pmus_lock);
8743 * We dereference the pmu list under both SRCU and regular RCU, so
8744 * synchronize against both of those.
8746 synchronize_srcu(&pmus_srcu);
8749 free_percpu(pmu->pmu_disable_count);
8750 if (pmu->type >= PERF_TYPE_MAX)
8751 idr_remove(&pmu_idr, pmu->type);
8752 if (pmu->nr_addr_filters)
8753 device_remove_file(pmu->dev, &dev_attr_nr_addr_filters);
8754 device_del(pmu->dev);
8755 put_device(pmu->dev);
8756 free_pmu_context(pmu);
8758 EXPORT_SYMBOL_GPL(perf_pmu_unregister);
8760 static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
8762 struct perf_event_context *ctx = NULL;
8765 if (!try_module_get(pmu->module))
8768 if (event->group_leader != event) {
8770 * This ctx->mutex can nest when we're called through
8771 * inheritance. See the perf_event_ctx_lock_nested() comment.
8773 ctx = perf_event_ctx_lock_nested(event->group_leader,
8774 SINGLE_DEPTH_NESTING);
8779 ret = pmu->event_init(event);
8782 perf_event_ctx_unlock(event->group_leader, ctx);
8785 module_put(pmu->module);
8790 static struct pmu *perf_init_event(struct perf_event *event)
8792 struct pmu *pmu = NULL;
8796 idx = srcu_read_lock(&pmus_srcu);
8799 pmu = idr_find(&pmu_idr, event->attr.type);
8802 ret = perf_try_init_event(pmu, event);
8808 list_for_each_entry_rcu(pmu, &pmus, entry) {
8809 ret = perf_try_init_event(pmu, event);
8813 if (ret != -ENOENT) {
8818 pmu = ERR_PTR(-ENOENT);
8820 srcu_read_unlock(&pmus_srcu, idx);
8825 static void attach_sb_event(struct perf_event *event)
8827 struct pmu_event_list *pel = per_cpu_ptr(&pmu_sb_events, event->cpu);
8829 raw_spin_lock(&pel->lock);
8830 list_add_rcu(&event->sb_list, &pel->list);
8831 raw_spin_unlock(&pel->lock);
8835 * We keep a list of all !task (and therefore per-cpu) events
8836 * that need to receive side-band records.
8838 * This avoids having to scan all the various PMU per-cpu contexts
8841 static void account_pmu_sb_event(struct perf_event *event)
8843 if (is_sb_event(event))
8844 attach_sb_event(event);
8847 static void account_event_cpu(struct perf_event *event, int cpu)
8852 if (is_cgroup_event(event))
8853 atomic_inc(&per_cpu(perf_cgroup_events, cpu));
8856 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
8857 static void account_freq_event_nohz(void)
8859 #ifdef CONFIG_NO_HZ_FULL
8860 /* Lock so we don't race with concurrent unaccount */
8861 spin_lock(&nr_freq_lock);
8862 if (atomic_inc_return(&nr_freq_events) == 1)
8863 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS);
8864 spin_unlock(&nr_freq_lock);
8868 static void account_freq_event(void)
8870 if (tick_nohz_full_enabled())
8871 account_freq_event_nohz();
8873 atomic_inc(&nr_freq_events);
8877 static void account_event(struct perf_event *event)
8884 if (event->attach_state & PERF_ATTACH_TASK)
8886 if (event->attr.mmap || event->attr.mmap_data)
8887 atomic_inc(&nr_mmap_events);
8888 if (event->attr.comm)
8889 atomic_inc(&nr_comm_events);
8890 if (event->attr.task)
8891 atomic_inc(&nr_task_events);
8892 if (event->attr.freq)
8893 account_freq_event();
8894 if (event->attr.context_switch) {
8895 atomic_inc(&nr_switch_events);
8898 if (has_branch_stack(event))
8900 if (is_cgroup_event(event))
8904 if (atomic_inc_not_zero(&perf_sched_count))
8907 mutex_lock(&perf_sched_mutex);
8908 if (!atomic_read(&perf_sched_count)) {
8909 static_branch_enable(&perf_sched_events);
8911 * Guarantee that all CPUs observe they key change and
8912 * call the perf scheduling hooks before proceeding to
8913 * install events that need them.
8915 synchronize_sched();
8918 * Now that we have waited for the sync_sched(), allow further
8919 * increments to by-pass the mutex.
8921 atomic_inc(&perf_sched_count);
8922 mutex_unlock(&perf_sched_mutex);
8926 account_event_cpu(event, event->cpu);
8928 account_pmu_sb_event(event);
8932 * Allocate and initialize a event structure
8934 static struct perf_event *
8935 perf_event_alloc(struct perf_event_attr *attr, int cpu,
8936 struct task_struct *task,
8937 struct perf_event *group_leader,
8938 struct perf_event *parent_event,
8939 perf_overflow_handler_t overflow_handler,
8940 void *context, int cgroup_fd)
8943 struct perf_event *event;
8944 struct hw_perf_event *hwc;
8947 if ((unsigned)cpu >= nr_cpu_ids) {
8948 if (!task || cpu != -1)
8949 return ERR_PTR(-EINVAL);
8952 event = kzalloc(sizeof(*event), GFP_KERNEL);
8954 return ERR_PTR(-ENOMEM);
8957 * Single events are their own group leaders, with an
8958 * empty sibling list:
8961 group_leader = event;
8963 mutex_init(&event->child_mutex);
8964 INIT_LIST_HEAD(&event->child_list);
8966 INIT_LIST_HEAD(&event->group_entry);
8967 INIT_LIST_HEAD(&event->event_entry);
8968 INIT_LIST_HEAD(&event->sibling_list);
8969 INIT_LIST_HEAD(&event->rb_entry);
8970 INIT_LIST_HEAD(&event->active_entry);
8971 INIT_LIST_HEAD(&event->addr_filters.list);
8972 INIT_HLIST_NODE(&event->hlist_entry);
8975 init_waitqueue_head(&event->waitq);
8976 init_irq_work(&event->pending, perf_pending_event);
8978 mutex_init(&event->mmap_mutex);
8979 raw_spin_lock_init(&event->addr_filters.lock);
8981 atomic_long_set(&event->refcount, 1);
8983 event->attr = *attr;
8984 event->group_leader = group_leader;
8988 event->parent = parent_event;
8990 event->ns = get_pid_ns(task_active_pid_ns(current));
8991 event->id = atomic64_inc_return(&perf_event_id);
8993 event->state = PERF_EVENT_STATE_INACTIVE;
8996 event->attach_state = PERF_ATTACH_TASK;
8998 * XXX pmu::event_init needs to know what task to account to
8999 * and we cannot use the ctx information because we need the
9000 * pmu before we get a ctx.
9002 event->hw.target = task;
9005 event->clock = &local_clock;
9007 event->clock = parent_event->clock;
9009 if (!overflow_handler && parent_event) {
9010 overflow_handler = parent_event->overflow_handler;
9011 context = parent_event->overflow_handler_context;
9014 if (overflow_handler) {
9015 event->overflow_handler = overflow_handler;
9016 event->overflow_handler_context = context;
9017 } else if (is_write_backward(event)){
9018 event->overflow_handler = perf_event_output_backward;
9019 event->overflow_handler_context = NULL;
9021 event->overflow_handler = perf_event_output_forward;
9022 event->overflow_handler_context = NULL;
9025 perf_event__state_init(event);
9030 hwc->sample_period = attr->sample_period;
9031 if (attr->freq && attr->sample_freq)
9032 hwc->sample_period = 1;
9033 hwc->last_period = hwc->sample_period;
9035 local64_set(&hwc->period_left, hwc->sample_period);
9038 * we currently do not support PERF_FORMAT_GROUP on inherited events
9040 if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
9043 if (!has_branch_stack(event))
9044 event->attr.branch_sample_type = 0;
9046 if (cgroup_fd != -1) {
9047 err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
9052 pmu = perf_init_event(event);
9055 else if (IS_ERR(pmu)) {
9060 err = exclusive_event_init(event);
9064 if (has_addr_filter(event)) {
9065 event->addr_filters_offs = kcalloc(pmu->nr_addr_filters,
9066 sizeof(unsigned long),
9068 if (!event->addr_filters_offs)
9071 /* force hw sync on the address filters */
9072 event->addr_filters_gen = 1;
9075 if (!event->parent) {
9076 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
9077 err = get_callchain_buffers(attr->sample_max_stack);
9079 goto err_addr_filters;
9083 /* symmetric to unaccount_event() in _free_event() */
9084 account_event(event);
9089 kfree(event->addr_filters_offs);
9092 exclusive_event_destroy(event);
9096 event->destroy(event);
9097 module_put(pmu->module);
9099 if (is_cgroup_event(event))
9100 perf_detach_cgroup(event);
9102 put_pid_ns(event->ns);
9105 return ERR_PTR(err);
9108 static int perf_copy_attr(struct perf_event_attr __user *uattr,
9109 struct perf_event_attr *attr)
9114 if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
9118 * zero the full structure, so that a short copy will be nice.
9120 memset(attr, 0, sizeof(*attr));
9122 ret = get_user(size, &uattr->size);
9126 if (size > PAGE_SIZE) /* silly large */
9129 if (!size) /* abi compat */
9130 size = PERF_ATTR_SIZE_VER0;
9132 if (size < PERF_ATTR_SIZE_VER0)
9136 * If we're handed a bigger struct than we know of,
9137 * ensure all the unknown bits are 0 - i.e. new
9138 * user-space does not rely on any kernel feature
9139 * extensions we dont know about yet.
9141 if (size > sizeof(*attr)) {
9142 unsigned char __user *addr;
9143 unsigned char __user *end;
9146 addr = (void __user *)uattr + sizeof(*attr);
9147 end = (void __user *)uattr + size;
9149 for (; addr < end; addr++) {
9150 ret = get_user(val, addr);
9156 size = sizeof(*attr);
9159 ret = copy_from_user(attr, uattr, size);
9163 if (attr->__reserved_1)
9166 if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
9169 if (attr->read_format & ~(PERF_FORMAT_MAX-1))
9172 if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
9173 u64 mask = attr->branch_sample_type;
9175 /* only using defined bits */
9176 if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1))
9179 /* at least one branch bit must be set */
9180 if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL))
9183 /* propagate priv level, when not set for branch */
9184 if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) {
9186 /* exclude_kernel checked on syscall entry */
9187 if (!attr->exclude_kernel)
9188 mask |= PERF_SAMPLE_BRANCH_KERNEL;
9190 if (!attr->exclude_user)
9191 mask |= PERF_SAMPLE_BRANCH_USER;
9193 if (!attr->exclude_hv)
9194 mask |= PERF_SAMPLE_BRANCH_HV;
9196 * adjust user setting (for HW filter setup)
9198 attr->branch_sample_type = mask;
9200 /* privileged levels capture (kernel, hv): check permissions */
9201 if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM)
9202 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
9206 if (attr->sample_type & PERF_SAMPLE_REGS_USER) {
9207 ret = perf_reg_validate(attr->sample_regs_user);
9212 if (attr->sample_type & PERF_SAMPLE_STACK_USER) {
9213 if (!arch_perf_have_user_stack_dump())
9217 * We have __u32 type for the size, but so far
9218 * we can only use __u16 as maximum due to the
9219 * __u16 sample size limit.
9221 if (attr->sample_stack_user >= USHRT_MAX)
9223 else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
9227 if (attr->sample_type & PERF_SAMPLE_REGS_INTR)
9228 ret = perf_reg_validate(attr->sample_regs_intr);
9233 put_user(sizeof(*attr), &uattr->size);
9239 perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
9241 struct ring_buffer *rb = NULL;
9247 /* don't allow circular references */
9248 if (event == output_event)
9252 * Don't allow cross-cpu buffers
9254 if (output_event->cpu != event->cpu)
9258 * If its not a per-cpu rb, it must be the same task.
9260 if (output_event->cpu == -1 && output_event->ctx != event->ctx)
9264 * Mixing clocks in the same buffer is trouble you don't need.
9266 if (output_event->clock != event->clock)
9270 * Either writing ring buffer from beginning or from end.
9271 * Mixing is not allowed.
9273 if (is_write_backward(output_event) != is_write_backward(event))
9277 * If both events generate aux data, they must be on the same PMU
9279 if (has_aux(event) && has_aux(output_event) &&
9280 event->pmu != output_event->pmu)
9284 mutex_lock(&event->mmap_mutex);
9285 /* Can't redirect output if we've got an active mmap() */
9286 if (atomic_read(&event->mmap_count))
9290 /* get the rb we want to redirect to */
9291 rb = ring_buffer_get(output_event);
9296 ring_buffer_attach(event, rb);
9300 mutex_unlock(&event->mmap_mutex);
9306 static void mutex_lock_double(struct mutex *a, struct mutex *b)
9312 mutex_lock_nested(b, SINGLE_DEPTH_NESTING);
9315 static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
9317 bool nmi_safe = false;
9320 case CLOCK_MONOTONIC:
9321 event->clock = &ktime_get_mono_fast_ns;
9325 case CLOCK_MONOTONIC_RAW:
9326 event->clock = &ktime_get_raw_fast_ns;
9330 case CLOCK_REALTIME:
9331 event->clock = &ktime_get_real_ns;
9334 case CLOCK_BOOTTIME:
9335 event->clock = &ktime_get_boot_ns;
9339 event->clock = &ktime_get_tai_ns;
9346 if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI))
9353 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9355 * @attr_uptr: event_id type attributes for monitoring/sampling
9358 * @group_fd: group leader event fd
9360 SYSCALL_DEFINE5(perf_event_open,
9361 struct perf_event_attr __user *, attr_uptr,
9362 pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
9364 struct perf_event *group_leader = NULL, *output_event = NULL;
9365 struct perf_event *event, *sibling;
9366 struct perf_event_attr attr;
9367 struct perf_event_context *ctx, *uninitialized_var(gctx);
9368 struct file *event_file = NULL;
9369 struct fd group = {NULL, 0};
9370 struct task_struct *task = NULL;
9375 int f_flags = O_RDWR;
9378 /* for future expandability... */
9379 if (flags & ~PERF_FLAG_ALL)
9382 err = perf_copy_attr(attr_uptr, &attr);
9386 if (!attr.exclude_kernel) {
9387 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
9392 if (attr.sample_freq > sysctl_perf_event_sample_rate)
9395 if (attr.sample_period & (1ULL << 63))
9399 if (!attr.sample_max_stack)
9400 attr.sample_max_stack = sysctl_perf_event_max_stack;
9403 * In cgroup mode, the pid argument is used to pass the fd
9404 * opened to the cgroup directory in cgroupfs. The cpu argument
9405 * designates the cpu on which to monitor threads from that
9408 if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
9411 if (flags & PERF_FLAG_FD_CLOEXEC)
9412 f_flags |= O_CLOEXEC;
9414 event_fd = get_unused_fd_flags(f_flags);
9418 if (group_fd != -1) {
9419 err = perf_fget_light(group_fd, &group);
9422 group_leader = group.file->private_data;
9423 if (flags & PERF_FLAG_FD_OUTPUT)
9424 output_event = group_leader;
9425 if (flags & PERF_FLAG_FD_NO_GROUP)
9426 group_leader = NULL;
9429 if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) {
9430 task = find_lively_task_by_vpid(pid);
9432 err = PTR_ERR(task);
9437 if (task && group_leader &&
9438 group_leader->attr.inherit != attr.inherit) {
9446 err = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
9451 * Reuse ptrace permission checks for now.
9453 * We must hold cred_guard_mutex across this and any potential
9454 * perf_install_in_context() call for this new event to
9455 * serialize against exec() altering our credentials (and the
9456 * perf_event_exit_task() that could imply).
9459 if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
9463 if (flags & PERF_FLAG_PID_CGROUP)
9466 event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
9467 NULL, NULL, cgroup_fd);
9468 if (IS_ERR(event)) {
9469 err = PTR_ERR(event);
9473 if (is_sampling_event(event)) {
9474 if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
9481 * Special case software events and allow them to be part of
9482 * any hardware group.
9486 if (attr.use_clockid) {
9487 err = perf_event_set_clock(event, attr.clockid);
9493 (is_software_event(event) != is_software_event(group_leader))) {
9494 if (is_software_event(event)) {
9496 * If event and group_leader are not both a software
9497 * event, and event is, then group leader is not.
9499 * Allow the addition of software events to !software
9500 * groups, this is safe because software events never
9503 pmu = group_leader->pmu;
9504 } else if (is_software_event(group_leader) &&
9505 (group_leader->group_flags & PERF_GROUP_SOFTWARE)) {
9507 * In case the group is a pure software group, and we
9508 * try to add a hardware event, move the whole group to
9509 * the hardware context.
9516 * Get the target context (task or percpu):
9518 ctx = find_get_context(pmu, task, event);
9524 if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) {
9530 * Look up the group leader (we will attach this event to it):
9536 * Do not allow a recursive hierarchy (this new sibling
9537 * becoming part of another group-sibling):
9539 if (group_leader->group_leader != group_leader)
9542 /* All events in a group should have the same clock */
9543 if (group_leader->clock != event->clock)
9547 * Do not allow to attach to a group in a different
9548 * task or CPU context:
9552 * Make sure we're both on the same task, or both
9555 if (group_leader->ctx->task != ctx->task)
9559 * Make sure we're both events for the same CPU;
9560 * grouping events for different CPUs is broken; since
9561 * you can never concurrently schedule them anyhow.
9563 if (group_leader->cpu != event->cpu)
9566 if (group_leader->ctx != ctx)
9571 * Only a group leader can be exclusive or pinned
9573 if (attr.exclusive || attr.pinned)
9578 err = perf_event_set_output(event, output_event);
9583 event_file = anon_inode_getfile("[perf_event]", &perf_fops, event,
9585 if (IS_ERR(event_file)) {
9586 err = PTR_ERR(event_file);
9592 gctx = group_leader->ctx;
9593 mutex_lock_double(&gctx->mutex, &ctx->mutex);
9594 if (gctx->task == TASK_TOMBSTONE) {
9599 mutex_lock(&ctx->mutex);
9602 if (ctx->task == TASK_TOMBSTONE) {
9607 if (!perf_event_validate_size(event)) {
9613 * Must be under the same ctx::mutex as perf_install_in_context(),
9614 * because we need to serialize with concurrent event creation.
9616 if (!exclusive_event_installable(event, ctx)) {
9617 /* exclusive and group stuff are assumed mutually exclusive */
9618 WARN_ON_ONCE(move_group);
9624 WARN_ON_ONCE(ctx->parent_ctx);
9627 * This is the point on no return; we cannot fail hereafter. This is
9628 * where we start modifying current state.
9633 * See perf_event_ctx_lock() for comments on the details
9634 * of swizzling perf_event::ctx.
9636 perf_remove_from_context(group_leader, 0);
9638 list_for_each_entry(sibling, &group_leader->sibling_list,
9640 perf_remove_from_context(sibling, 0);
9645 * Wait for everybody to stop referencing the events through
9646 * the old lists, before installing it on new lists.
9651 * Install the group siblings before the group leader.
9653 * Because a group leader will try and install the entire group
9654 * (through the sibling list, which is still in-tact), we can
9655 * end up with siblings installed in the wrong context.
9657 * By installing siblings first we NO-OP because they're not
9658 * reachable through the group lists.
9660 list_for_each_entry(sibling, &group_leader->sibling_list,
9662 perf_event__state_init(sibling);
9663 perf_install_in_context(ctx, sibling, sibling->cpu);
9668 * Removing from the context ends up with disabled
9669 * event. What we want here is event in the initial
9670 * startup state, ready to be add into new context.
9672 perf_event__state_init(group_leader);
9673 perf_install_in_context(ctx, group_leader, group_leader->cpu);
9677 * Now that all events are installed in @ctx, nothing
9678 * references @gctx anymore, so drop the last reference we have
9685 * Precalculate sample_data sizes; do while holding ctx::mutex such
9686 * that we're serialized against further additions and before
9687 * perf_install_in_context() which is the point the event is active and
9688 * can use these values.
9690 perf_event__header_size(event);
9691 perf_event__id_header_size(event);
9693 event->owner = current;
9695 perf_install_in_context(ctx, event, event->cpu);
9696 perf_unpin_context(ctx);
9699 mutex_unlock(&gctx->mutex);
9700 mutex_unlock(&ctx->mutex);
9703 mutex_unlock(&task->signal->cred_guard_mutex);
9704 put_task_struct(task);
9709 mutex_lock(¤t->perf_event_mutex);
9710 list_add_tail(&event->owner_entry, ¤t->perf_event_list);
9711 mutex_unlock(¤t->perf_event_mutex);
9714 * Drop the reference on the group_event after placing the
9715 * new event on the sibling_list. This ensures destruction
9716 * of the group leader will find the pointer to itself in
9717 * perf_group_detach().
9720 fd_install(event_fd, event_file);
9725 mutex_unlock(&gctx->mutex);
9726 mutex_unlock(&ctx->mutex);
9730 perf_unpin_context(ctx);
9734 * If event_file is set, the fput() above will have called ->release()
9735 * and that will take care of freeing the event.
9741 mutex_unlock(&task->signal->cred_guard_mutex);
9746 put_task_struct(task);
9750 put_unused_fd(event_fd);
9755 * perf_event_create_kernel_counter
9757 * @attr: attributes of the counter to create
9758 * @cpu: cpu in which the counter is bound
9759 * @task: task to profile (NULL for percpu)
9762 perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
9763 struct task_struct *task,
9764 perf_overflow_handler_t overflow_handler,
9767 struct perf_event_context *ctx;
9768 struct perf_event *event;
9772 * Get the target context (task or percpu):
9775 event = perf_event_alloc(attr, cpu, task, NULL, NULL,
9776 overflow_handler, context, -1);
9777 if (IS_ERR(event)) {
9778 err = PTR_ERR(event);
9782 /* Mark owner so we could distinguish it from user events. */
9783 event->owner = TASK_TOMBSTONE;
9785 ctx = find_get_context(event->pmu, task, event);
9791 WARN_ON_ONCE(ctx->parent_ctx);
9792 mutex_lock(&ctx->mutex);
9793 if (ctx->task == TASK_TOMBSTONE) {
9798 if (!exclusive_event_installable(event, ctx)) {
9803 perf_install_in_context(ctx, event, cpu);
9804 perf_unpin_context(ctx);
9805 mutex_unlock(&ctx->mutex);
9810 mutex_unlock(&ctx->mutex);
9811 perf_unpin_context(ctx);
9816 return ERR_PTR(err);
9818 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
9820 void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
9822 struct perf_event_context *src_ctx;
9823 struct perf_event_context *dst_ctx;
9824 struct perf_event *event, *tmp;
9827 src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx;
9828 dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx;
9831 * See perf_event_ctx_lock() for comments on the details
9832 * of swizzling perf_event::ctx.
9834 mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex);
9835 list_for_each_entry_safe(event, tmp, &src_ctx->event_list,
9837 perf_remove_from_context(event, 0);
9838 unaccount_event_cpu(event, src_cpu);
9840 list_add(&event->migrate_entry, &events);
9844 * Wait for the events to quiesce before re-instating them.
9849 * Re-instate events in 2 passes.
9851 * Skip over group leaders and only install siblings on this first
9852 * pass, siblings will not get enabled without a leader, however a
9853 * leader will enable its siblings, even if those are still on the old
9856 list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
9857 if (event->group_leader == event)
9860 list_del(&event->migrate_entry);
9861 if (event->state >= PERF_EVENT_STATE_OFF)
9862 event->state = PERF_EVENT_STATE_INACTIVE;
9863 account_event_cpu(event, dst_cpu);
9864 perf_install_in_context(dst_ctx, event, dst_cpu);
9869 * Once all the siblings are setup properly, install the group leaders
9872 list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
9873 list_del(&event->migrate_entry);
9874 if (event->state >= PERF_EVENT_STATE_OFF)
9875 event->state = PERF_EVENT_STATE_INACTIVE;
9876 account_event_cpu(event, dst_cpu);
9877 perf_install_in_context(dst_ctx, event, dst_cpu);
9880 mutex_unlock(&dst_ctx->mutex);
9881 mutex_unlock(&src_ctx->mutex);
9883 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
9885 static void sync_child_event(struct perf_event *child_event,
9886 struct task_struct *child)
9888 struct perf_event *parent_event = child_event->parent;
9891 if (child_event->attr.inherit_stat)
9892 perf_event_read_event(child_event, child);
9894 child_val = perf_event_count(child_event);
9897 * Add back the child's count to the parent's count:
9899 atomic64_add(child_val, &parent_event->child_count);
9900 atomic64_add(child_event->total_time_enabled,
9901 &parent_event->child_total_time_enabled);
9902 atomic64_add(child_event->total_time_running,
9903 &parent_event->child_total_time_running);
9907 perf_event_exit_event(struct perf_event *child_event,
9908 struct perf_event_context *child_ctx,
9909 struct task_struct *child)
9911 struct perf_event *parent_event = child_event->parent;
9914 * Do not destroy the 'original' grouping; because of the context
9915 * switch optimization the original events could've ended up in a
9916 * random child task.
9918 * If we were to destroy the original group, all group related
9919 * operations would cease to function properly after this random
9922 * Do destroy all inherited groups, we don't care about those
9923 * and being thorough is better.
9925 raw_spin_lock_irq(&child_ctx->lock);
9926 WARN_ON_ONCE(child_ctx->is_active);
9929 perf_group_detach(child_event);
9930 list_del_event(child_event, child_ctx);
9931 child_event->state = PERF_EVENT_STATE_EXIT; /* is_event_hup() */
9932 raw_spin_unlock_irq(&child_ctx->lock);
9935 * Parent events are governed by their filedesc, retain them.
9937 if (!parent_event) {
9938 perf_event_wakeup(child_event);
9942 * Child events can be cleaned up.
9945 sync_child_event(child_event, child);
9948 * Remove this event from the parent's list
9950 WARN_ON_ONCE(parent_event->ctx->parent_ctx);
9951 mutex_lock(&parent_event->child_mutex);
9952 list_del_init(&child_event->child_list);
9953 mutex_unlock(&parent_event->child_mutex);
9956 * Kick perf_poll() for is_event_hup().
9958 perf_event_wakeup(parent_event);
9959 free_event(child_event);
9960 put_event(parent_event);
9963 static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
9965 struct perf_event_context *child_ctx, *clone_ctx = NULL;
9966 struct perf_event *child_event, *next;
9968 WARN_ON_ONCE(child != current);
9970 child_ctx = perf_pin_task_context(child, ctxn);
9975 * In order to reduce the amount of tricky in ctx tear-down, we hold
9976 * ctx::mutex over the entire thing. This serializes against almost
9977 * everything that wants to access the ctx.
9979 * The exception is sys_perf_event_open() /
9980 * perf_event_create_kernel_count() which does find_get_context()
9981 * without ctx::mutex (it cannot because of the move_group double mutex
9982 * lock thing). See the comments in perf_install_in_context().
9984 mutex_lock(&child_ctx->mutex);
9987 * In a single ctx::lock section, de-schedule the events and detach the
9988 * context from the task such that we cannot ever get it scheduled back
9991 raw_spin_lock_irq(&child_ctx->lock);
9992 task_ctx_sched_out(__get_cpu_context(child_ctx), child_ctx);
9995 * Now that the context is inactive, destroy the task <-> ctx relation
9996 * and mark the context dead.
9998 RCU_INIT_POINTER(child->perf_event_ctxp[ctxn], NULL);
9999 put_ctx(child_ctx); /* cannot be last */
10000 WRITE_ONCE(child_ctx->task, TASK_TOMBSTONE);
10001 put_task_struct(current); /* cannot be last */
10003 clone_ctx = unclone_ctx(child_ctx);
10004 raw_spin_unlock_irq(&child_ctx->lock);
10007 put_ctx(clone_ctx);
10010 * Report the task dead after unscheduling the events so that we
10011 * won't get any samples after PERF_RECORD_EXIT. We can however still
10012 * get a few PERF_RECORD_READ events.
10014 perf_event_task(child, child_ctx, 0);
10016 list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry)
10017 perf_event_exit_event(child_event, child_ctx, child);
10019 mutex_unlock(&child_ctx->mutex);
10021 put_ctx(child_ctx);
10025 * When a child task exits, feed back event values to parent events.
10027 * Can be called with cred_guard_mutex held when called from
10028 * install_exec_creds().
10030 void perf_event_exit_task(struct task_struct *child)
10032 struct perf_event *event, *tmp;
10035 mutex_lock(&child->perf_event_mutex);
10036 list_for_each_entry_safe(event, tmp, &child->perf_event_list,
10038 list_del_init(&event->owner_entry);
10041 * Ensure the list deletion is visible before we clear
10042 * the owner, closes a race against perf_release() where
10043 * we need to serialize on the owner->perf_event_mutex.
10045 smp_store_release(&event->owner, NULL);
10047 mutex_unlock(&child->perf_event_mutex);
10049 for_each_task_context_nr(ctxn)
10050 perf_event_exit_task_context(child, ctxn);
10053 * The perf_event_exit_task_context calls perf_event_task
10054 * with child's task_ctx, which generates EXIT events for
10055 * child contexts and sets child->perf_event_ctxp[] to NULL.
10056 * At this point we need to send EXIT events to cpu contexts.
10058 perf_event_task(child, NULL, 0);
10061 static void perf_free_event(struct perf_event *event,
10062 struct perf_event_context *ctx)
10064 struct perf_event *parent = event->parent;
10066 if (WARN_ON_ONCE(!parent))
10069 mutex_lock(&parent->child_mutex);
10070 list_del_init(&event->child_list);
10071 mutex_unlock(&parent->child_mutex);
10075 raw_spin_lock_irq(&ctx->lock);
10076 perf_group_detach(event);
10077 list_del_event(event, ctx);
10078 raw_spin_unlock_irq(&ctx->lock);
10083 * Free an unexposed, unused context as created by inheritance by
10084 * perf_event_init_task below, used by fork() in case of fail.
10086 * Not all locks are strictly required, but take them anyway to be nice and
10087 * help out with the lockdep assertions.
10089 void perf_event_free_task(struct task_struct *task)
10091 struct perf_event_context *ctx;
10092 struct perf_event *event, *tmp;
10095 for_each_task_context_nr(ctxn) {
10096 ctx = task->perf_event_ctxp[ctxn];
10100 mutex_lock(&ctx->mutex);
10102 list_for_each_entry_safe(event, tmp, &ctx->pinned_groups,
10104 perf_free_event(event, ctx);
10106 list_for_each_entry_safe(event, tmp, &ctx->flexible_groups,
10108 perf_free_event(event, ctx);
10110 if (!list_empty(&ctx->pinned_groups) ||
10111 !list_empty(&ctx->flexible_groups))
10114 mutex_unlock(&ctx->mutex);
10120 void perf_event_delayed_put(struct task_struct *task)
10124 for_each_task_context_nr(ctxn)
10125 WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
10128 struct file *perf_event_get(unsigned int fd)
10132 file = fget_raw(fd);
10134 return ERR_PTR(-EBADF);
10136 if (file->f_op != &perf_fops) {
10138 return ERR_PTR(-EBADF);
10144 const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
10147 return ERR_PTR(-EINVAL);
10149 return &event->attr;
10153 * inherit a event from parent task to child task:
10155 static struct perf_event *
10156 inherit_event(struct perf_event *parent_event,
10157 struct task_struct *parent,
10158 struct perf_event_context *parent_ctx,
10159 struct task_struct *child,
10160 struct perf_event *group_leader,
10161 struct perf_event_context *child_ctx)
10163 enum perf_event_active_state parent_state = parent_event->state;
10164 struct perf_event *child_event;
10165 unsigned long flags;
10168 * Instead of creating recursive hierarchies of events,
10169 * we link inherited events back to the original parent,
10170 * which has a filp for sure, which we use as the reference
10173 if (parent_event->parent)
10174 parent_event = parent_event->parent;
10176 child_event = perf_event_alloc(&parent_event->attr,
10179 group_leader, parent_event,
10181 if (IS_ERR(child_event))
10182 return child_event;
10185 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10186 * must be under the same lock in order to serialize against
10187 * perf_event_release_kernel(), such that either we must observe
10188 * is_orphaned_event() or they will observe us on the child_list.
10190 mutex_lock(&parent_event->child_mutex);
10191 if (is_orphaned_event(parent_event) ||
10192 !atomic_long_inc_not_zero(&parent_event->refcount)) {
10193 mutex_unlock(&parent_event->child_mutex);
10194 free_event(child_event);
10198 get_ctx(child_ctx);
10201 * Make the child state follow the state of the parent event,
10202 * not its attr.disabled bit. We hold the parent's mutex,
10203 * so we won't race with perf_event_{en, dis}able_family.
10205 if (parent_state >= PERF_EVENT_STATE_INACTIVE)
10206 child_event->state = PERF_EVENT_STATE_INACTIVE;
10208 child_event->state = PERF_EVENT_STATE_OFF;
10210 if (parent_event->attr.freq) {
10211 u64 sample_period = parent_event->hw.sample_period;
10212 struct hw_perf_event *hwc = &child_event->hw;
10214 hwc->sample_period = sample_period;
10215 hwc->last_period = sample_period;
10217 local64_set(&hwc->period_left, sample_period);
10220 child_event->ctx = child_ctx;
10221 child_event->overflow_handler = parent_event->overflow_handler;
10222 child_event->overflow_handler_context
10223 = parent_event->overflow_handler_context;
10226 * Precalculate sample_data sizes
10228 perf_event__header_size(child_event);
10229 perf_event__id_header_size(child_event);
10232 * Link it up in the child's context:
10234 raw_spin_lock_irqsave(&child_ctx->lock, flags);
10235 add_event_to_ctx(child_event, child_ctx);
10236 raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
10239 * Link this into the parent event's child list
10241 list_add_tail(&child_event->child_list, &parent_event->child_list);
10242 mutex_unlock(&parent_event->child_mutex);
10244 return child_event;
10247 static int inherit_group(struct perf_event *parent_event,
10248 struct task_struct *parent,
10249 struct perf_event_context *parent_ctx,
10250 struct task_struct *child,
10251 struct perf_event_context *child_ctx)
10253 struct perf_event *leader;
10254 struct perf_event *sub;
10255 struct perf_event *child_ctr;
10257 leader = inherit_event(parent_event, parent, parent_ctx,
10258 child, NULL, child_ctx);
10259 if (IS_ERR(leader))
10260 return PTR_ERR(leader);
10261 list_for_each_entry(sub, &parent_event->sibling_list, group_entry) {
10262 child_ctr = inherit_event(sub, parent, parent_ctx,
10263 child, leader, child_ctx);
10264 if (IS_ERR(child_ctr))
10265 return PTR_ERR(child_ctr);
10271 inherit_task_group(struct perf_event *event, struct task_struct *parent,
10272 struct perf_event_context *parent_ctx,
10273 struct task_struct *child, int ctxn,
10274 int *inherited_all)
10277 struct perf_event_context *child_ctx;
10279 if (!event->attr.inherit) {
10280 *inherited_all = 0;
10284 child_ctx = child->perf_event_ctxp[ctxn];
10287 * This is executed from the parent task context, so
10288 * inherit events that have been marked for cloning.
10289 * First allocate and initialize a context for the
10293 child_ctx = alloc_perf_context(parent_ctx->pmu, child);
10297 child->perf_event_ctxp[ctxn] = child_ctx;
10300 ret = inherit_group(event, parent, parent_ctx,
10304 *inherited_all = 0;
10310 * Initialize the perf_event context in task_struct
10312 static int perf_event_init_context(struct task_struct *child, int ctxn)
10314 struct perf_event_context *child_ctx, *parent_ctx;
10315 struct perf_event_context *cloned_ctx;
10316 struct perf_event *event;
10317 struct task_struct *parent = current;
10318 int inherited_all = 1;
10319 unsigned long flags;
10322 if (likely(!parent->perf_event_ctxp[ctxn]))
10326 * If the parent's context is a clone, pin it so it won't get
10327 * swapped under us.
10329 parent_ctx = perf_pin_task_context(parent, ctxn);
10334 * No need to check if parent_ctx != NULL here; since we saw
10335 * it non-NULL earlier, the only reason for it to become NULL
10336 * is if we exit, and since we're currently in the middle of
10337 * a fork we can't be exiting at the same time.
10341 * Lock the parent list. No need to lock the child - not PID
10342 * hashed yet and not running, so nobody can access it.
10344 mutex_lock(&parent_ctx->mutex);
10347 * We dont have to disable NMIs - we are only looking at
10348 * the list, not manipulating it:
10350 list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) {
10351 ret = inherit_task_group(event, parent, parent_ctx,
10352 child, ctxn, &inherited_all);
10358 * We can't hold ctx->lock when iterating the ->flexible_group list due
10359 * to allocations, but we need to prevent rotation because
10360 * rotate_ctx() will change the list from interrupt context.
10362 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
10363 parent_ctx->rotate_disable = 1;
10364 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
10366 list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) {
10367 ret = inherit_task_group(event, parent, parent_ctx,
10368 child, ctxn, &inherited_all);
10373 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
10374 parent_ctx->rotate_disable = 0;
10376 child_ctx = child->perf_event_ctxp[ctxn];
10378 if (child_ctx && inherited_all) {
10380 * Mark the child context as a clone of the parent
10381 * context, or of whatever the parent is a clone of.
10383 * Note that if the parent is a clone, the holding of
10384 * parent_ctx->lock avoids it from being uncloned.
10386 cloned_ctx = parent_ctx->parent_ctx;
10388 child_ctx->parent_ctx = cloned_ctx;
10389 child_ctx->parent_gen = parent_ctx->parent_gen;
10391 child_ctx->parent_ctx = parent_ctx;
10392 child_ctx->parent_gen = parent_ctx->generation;
10394 get_ctx(child_ctx->parent_ctx);
10397 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
10398 mutex_unlock(&parent_ctx->mutex);
10400 perf_unpin_context(parent_ctx);
10401 put_ctx(parent_ctx);
10407 * Initialize the perf_event context in task_struct
10409 int perf_event_init_task(struct task_struct *child)
10413 memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
10414 mutex_init(&child->perf_event_mutex);
10415 INIT_LIST_HEAD(&child->perf_event_list);
10417 for_each_task_context_nr(ctxn) {
10418 ret = perf_event_init_context(child, ctxn);
10420 perf_event_free_task(child);
10428 static void __init perf_event_init_all_cpus(void)
10430 struct swevent_htable *swhash;
10433 for_each_possible_cpu(cpu) {
10434 swhash = &per_cpu(swevent_htable, cpu);
10435 mutex_init(&swhash->hlist_mutex);
10436 INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu));
10438 INIT_LIST_HEAD(&per_cpu(pmu_sb_events.list, cpu));
10439 raw_spin_lock_init(&per_cpu(pmu_sb_events.lock, cpu));
10441 INIT_LIST_HEAD(&per_cpu(sched_cb_list, cpu));
10445 int perf_event_init_cpu(unsigned int cpu)
10447 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
10449 mutex_lock(&swhash->hlist_mutex);
10450 if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) {
10451 struct swevent_hlist *hlist;
10453 hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
10455 rcu_assign_pointer(swhash->swevent_hlist, hlist);
10457 mutex_unlock(&swhash->hlist_mutex);
10461 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
10462 static void __perf_event_exit_context(void *__info)
10464 struct perf_event_context *ctx = __info;
10465 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
10466 struct perf_event *event;
10468 raw_spin_lock(&ctx->lock);
10469 list_for_each_entry(event, &ctx->event_list, event_entry)
10470 __perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP);
10471 raw_spin_unlock(&ctx->lock);
10474 static void perf_event_exit_cpu_context(int cpu)
10476 struct perf_event_context *ctx;
10480 idx = srcu_read_lock(&pmus_srcu);
10481 list_for_each_entry_rcu(pmu, &pmus, entry) {
10482 ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx;
10484 mutex_lock(&ctx->mutex);
10485 smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
10486 mutex_unlock(&ctx->mutex);
10488 srcu_read_unlock(&pmus_srcu, idx);
10492 static void perf_event_exit_cpu_context(int cpu) { }
10496 int perf_event_exit_cpu(unsigned int cpu)
10498 perf_event_exit_cpu_context(cpu);
10503 perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
10507 for_each_online_cpu(cpu)
10508 perf_event_exit_cpu(cpu);
10514 * Run the perf reboot notifier at the very last possible moment so that
10515 * the generic watchdog code runs as long as possible.
10517 static struct notifier_block perf_reboot_notifier = {
10518 .notifier_call = perf_reboot,
10519 .priority = INT_MIN,
10522 void __init perf_event_init(void)
10526 idr_init(&pmu_idr);
10528 perf_event_init_all_cpus();
10529 init_srcu_struct(&pmus_srcu);
10530 perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
10531 perf_pmu_register(&perf_cpu_clock, NULL, -1);
10532 perf_pmu_register(&perf_task_clock, NULL, -1);
10533 perf_tp_register();
10534 perf_event_init_cpu(smp_processor_id());
10535 register_reboot_notifier(&perf_reboot_notifier);
10537 ret = init_hw_breakpoint();
10538 WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
10541 * Build time assertion that we keep the data_head at the intended
10542 * location. IOW, validation we got the __reserved[] size right.
10544 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head))
10548 ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
10551 struct perf_pmu_events_attr *pmu_attr =
10552 container_of(attr, struct perf_pmu_events_attr, attr);
10554 if (pmu_attr->event_str)
10555 return sprintf(page, "%s\n", pmu_attr->event_str);
10559 EXPORT_SYMBOL_GPL(perf_event_sysfs_show);
10561 static int __init perf_event_sysfs_init(void)
10566 mutex_lock(&pmus_lock);
10568 ret = bus_register(&pmu_bus);
10572 list_for_each_entry(pmu, &pmus, entry) {
10573 if (!pmu->name || pmu->type < 0)
10576 ret = pmu_dev_alloc(pmu);
10577 WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret);
10579 pmu_bus_running = 1;
10583 mutex_unlock(&pmus_lock);
10587 device_initcall(perf_event_sysfs_init);
10589 #ifdef CONFIG_CGROUP_PERF
10590 static struct cgroup_subsys_state *
10591 perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
10593 struct perf_cgroup *jc;
10595 jc = kzalloc(sizeof(*jc), GFP_KERNEL);
10597 return ERR_PTR(-ENOMEM);
10599 jc->info = alloc_percpu(struct perf_cgroup_info);
10602 return ERR_PTR(-ENOMEM);
10608 static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
10610 struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css);
10612 free_percpu(jc->info);
10616 static int __perf_cgroup_move(void *info)
10618 struct task_struct *task = info;
10620 perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN);
10625 static void perf_cgroup_attach(struct cgroup_taskset *tset)
10627 struct task_struct *task;
10628 struct cgroup_subsys_state *css;
10630 cgroup_taskset_for_each(task, css, tset)
10631 task_function_call(task, __perf_cgroup_move, task);
10634 struct cgroup_subsys perf_event_cgrp_subsys = {
10635 .css_alloc = perf_cgroup_css_alloc,
10636 .css_free = perf_cgroup_css_free,
10637 .attach = perf_cgroup_attach,
10639 #endif /* CONFIG_CGROUP_PERF */