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>
50 #include <asm/irq_regs.h>
52 static struct workqueue_struct *perf_wq;
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() || !task_curr(p))
74 tfc->ret = tfc->func(tfc->info);
78 * task_function_call - call a function on the cpu on which a task runs
79 * @p: the task to evaluate
80 * @func: the function to be called
81 * @info: the function call argument
83 * Calls the function @func when the task is currently running. This might
84 * be on the current CPU, which just calls the function directly
86 * returns: @func return value, or
87 * -ESRCH - when the process isn't running
88 * -EAGAIN - when the process moved away
91 task_function_call(struct task_struct *p, remote_function_f func, void *info)
93 struct remote_function_call data = {
97 .ret = -ESRCH, /* No such (running) process */
101 smp_call_function_single(task_cpu(p), remote_function, &data, 1);
107 * cpu_function_call - call a function on the cpu
108 * @func: the function to be called
109 * @info: the function call argument
111 * Calls the function @func on the remote cpu.
113 * returns: @func return value or -ENXIO when the cpu is offline
115 static int cpu_function_call(int cpu, remote_function_f func, void *info)
117 struct remote_function_call data = {
121 .ret = -ENXIO, /* No such CPU */
124 smp_call_function_single(cpu, remote_function, &data, 1);
129 #define EVENT_OWNER_KERNEL ((void *) -1)
131 static bool is_kernel_event(struct perf_event *event)
133 return event->owner == EVENT_OWNER_KERNEL;
136 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
137 PERF_FLAG_FD_OUTPUT |\
138 PERF_FLAG_PID_CGROUP |\
139 PERF_FLAG_FD_CLOEXEC)
142 * branch priv levels that need permission checks
144 #define PERF_SAMPLE_BRANCH_PERM_PLM \
145 (PERF_SAMPLE_BRANCH_KERNEL |\
146 PERF_SAMPLE_BRANCH_HV)
149 EVENT_FLEXIBLE = 0x1,
151 EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
155 * perf_sched_events : >0 events exist
156 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
158 struct static_key_deferred perf_sched_events __read_mostly;
159 static DEFINE_PER_CPU(atomic_t, perf_cgroup_events);
160 static DEFINE_PER_CPU(int, perf_sched_cb_usages);
162 static atomic_t nr_mmap_events __read_mostly;
163 static atomic_t nr_comm_events __read_mostly;
164 static atomic_t nr_task_events __read_mostly;
165 static atomic_t nr_freq_events __read_mostly;
166 static atomic_t nr_switch_events __read_mostly;
168 static LIST_HEAD(pmus);
169 static DEFINE_MUTEX(pmus_lock);
170 static struct srcu_struct pmus_srcu;
173 * perf event paranoia level:
174 * -1 - not paranoid at all
175 * 0 - disallow raw tracepoint access for unpriv
176 * 1 - disallow cpu events for unpriv
177 * 2 - disallow kernel profiling for unpriv
178 * 3 - disallow all unpriv perf event use
180 #ifdef CONFIG_SECURITY_PERF_EVENTS_RESTRICT
181 int sysctl_perf_event_paranoid __read_mostly = 3;
183 int sysctl_perf_event_paranoid __read_mostly = 1;
186 /* Minimum for 512 kiB + 1 user control page */
187 int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */
190 * max perf event sample rate
192 #define DEFAULT_MAX_SAMPLE_RATE 100000
193 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
194 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
196 int sysctl_perf_event_sample_rate __read_mostly = DEFAULT_MAX_SAMPLE_RATE;
198 static int max_samples_per_tick __read_mostly = DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE, HZ);
199 static int perf_sample_period_ns __read_mostly = DEFAULT_SAMPLE_PERIOD_NS;
201 static int perf_sample_allowed_ns __read_mostly =
202 DEFAULT_SAMPLE_PERIOD_NS * DEFAULT_CPU_TIME_MAX_PERCENT / 100;
204 static void update_perf_cpu_limits(void)
206 u64 tmp = perf_sample_period_ns;
208 tmp *= sysctl_perf_cpu_time_max_percent;
210 ACCESS_ONCE(perf_sample_allowed_ns) = tmp;
213 static int perf_rotate_context(struct perf_cpu_context *cpuctx);
215 int perf_proc_update_handler(struct ctl_table *table, int write,
216 void __user *buffer, size_t *lenp,
219 int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
224 max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ);
225 perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
226 update_perf_cpu_limits();
231 int sysctl_perf_cpu_time_max_percent __read_mostly = DEFAULT_CPU_TIME_MAX_PERCENT;
233 int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
234 void __user *buffer, size_t *lenp,
237 int ret = proc_dointvec(table, write, buffer, lenp, ppos);
242 update_perf_cpu_limits();
248 * perf samples are done in some very critical code paths (NMIs).
249 * If they take too much CPU time, the system can lock up and not
250 * get any real work done. This will drop the sample rate when
251 * we detect that events are taking too long.
253 #define NR_ACCUMULATED_SAMPLES 128
254 static DEFINE_PER_CPU(u64, running_sample_length);
256 static void perf_duration_warn(struct irq_work *w)
258 u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns);
259 u64 avg_local_sample_len;
260 u64 local_samples_len;
262 local_samples_len = __this_cpu_read(running_sample_length);
263 avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES;
265 printk_ratelimited(KERN_WARNING
266 "perf interrupt took too long (%lld > %lld), lowering "
267 "kernel.perf_event_max_sample_rate to %d\n",
268 avg_local_sample_len, allowed_ns >> 1,
269 sysctl_perf_event_sample_rate);
272 static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn);
274 void perf_sample_event_took(u64 sample_len_ns)
276 u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns);
277 u64 avg_local_sample_len;
278 u64 local_samples_len;
283 /* decay the counter by 1 average sample */
284 local_samples_len = __this_cpu_read(running_sample_length);
285 local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES;
286 local_samples_len += sample_len_ns;
287 __this_cpu_write(running_sample_length, local_samples_len);
290 * note: this will be biased artifically low until we have
291 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
292 * from having to maintain a count.
294 avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES;
296 if (avg_local_sample_len <= allowed_ns)
299 if (max_samples_per_tick <= 1)
302 max_samples_per_tick = DIV_ROUND_UP(max_samples_per_tick, 2);
303 sysctl_perf_event_sample_rate = max_samples_per_tick * HZ;
304 perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
306 update_perf_cpu_limits();
308 if (!irq_work_queue(&perf_duration_work)) {
309 early_printk("perf interrupt took too long (%lld > %lld), lowering "
310 "kernel.perf_event_max_sample_rate to %d\n",
311 avg_local_sample_len, allowed_ns >> 1,
312 sysctl_perf_event_sample_rate);
316 static atomic64_t perf_event_id;
318 static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
319 enum event_type_t event_type);
321 static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
322 enum event_type_t event_type,
323 struct task_struct *task);
325 static void update_context_time(struct perf_event_context *ctx);
326 static u64 perf_event_time(struct perf_event *event);
328 void __weak perf_event_print_debug(void) { }
330 extern __weak const char *perf_pmu_name(void)
335 static inline u64 perf_clock(void)
337 return local_clock();
340 static inline u64 perf_event_clock(struct perf_event *event)
342 return event->clock();
345 static inline struct perf_cpu_context *
346 __get_cpu_context(struct perf_event_context *ctx)
348 return this_cpu_ptr(ctx->pmu->pmu_cpu_context);
351 static void perf_ctx_lock(struct perf_cpu_context *cpuctx,
352 struct perf_event_context *ctx)
354 raw_spin_lock(&cpuctx->ctx.lock);
356 raw_spin_lock(&ctx->lock);
359 static void perf_ctx_unlock(struct perf_cpu_context *cpuctx,
360 struct perf_event_context *ctx)
363 raw_spin_unlock(&ctx->lock);
364 raw_spin_unlock(&cpuctx->ctx.lock);
367 #ifdef CONFIG_CGROUP_PERF
370 perf_cgroup_match(struct perf_event *event)
372 struct perf_event_context *ctx = event->ctx;
373 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
375 /* @event doesn't care about cgroup */
379 /* wants specific cgroup scope but @cpuctx isn't associated with any */
384 * Cgroup scoping is recursive. An event enabled for a cgroup is
385 * also enabled for all its descendant cgroups. If @cpuctx's
386 * cgroup is a descendant of @event's (the test covers identity
387 * case), it's a match.
389 return cgroup_is_descendant(cpuctx->cgrp->css.cgroup,
390 event->cgrp->css.cgroup);
393 static inline void perf_detach_cgroup(struct perf_event *event)
395 css_put(&event->cgrp->css);
399 static inline int is_cgroup_event(struct perf_event *event)
401 return event->cgrp != NULL;
404 static inline u64 perf_cgroup_event_time(struct perf_event *event)
406 struct perf_cgroup_info *t;
408 t = per_cpu_ptr(event->cgrp->info, event->cpu);
412 static inline void __update_cgrp_time(struct perf_cgroup *cgrp)
414 struct perf_cgroup_info *info;
419 info = this_cpu_ptr(cgrp->info);
421 info->time += now - info->timestamp;
422 info->timestamp = now;
425 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
427 struct perf_cgroup *cgrp_out = cpuctx->cgrp;
429 __update_cgrp_time(cgrp_out);
432 static inline void update_cgrp_time_from_event(struct perf_event *event)
434 struct perf_cgroup *cgrp;
437 * ensure we access cgroup data only when needed and
438 * when we know the cgroup is pinned (css_get)
440 if (!is_cgroup_event(event))
443 cgrp = perf_cgroup_from_task(current, event->ctx);
445 * Do not update time when cgroup is not active
447 if (cgrp == event->cgrp)
448 __update_cgrp_time(event->cgrp);
452 perf_cgroup_set_timestamp(struct task_struct *task,
453 struct perf_event_context *ctx)
455 struct perf_cgroup *cgrp;
456 struct perf_cgroup_info *info;
459 * ctx->lock held by caller
460 * ensure we do not access cgroup data
461 * unless we have the cgroup pinned (css_get)
463 if (!task || !ctx->nr_cgroups)
466 cgrp = perf_cgroup_from_task(task, ctx);
467 info = this_cpu_ptr(cgrp->info);
468 info->timestamp = ctx->timestamp;
471 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
472 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
475 * reschedule events based on the cgroup constraint of task.
477 * mode SWOUT : schedule out everything
478 * mode SWIN : schedule in based on cgroup for next
480 static void perf_cgroup_switch(struct task_struct *task, int mode)
482 struct perf_cpu_context *cpuctx;
487 * disable interrupts to avoid geting nr_cgroup
488 * changes via __perf_event_disable(). Also
491 local_irq_save(flags);
494 * we reschedule only in the presence of cgroup
495 * constrained events.
498 list_for_each_entry_rcu(pmu, &pmus, entry) {
499 cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
500 if (cpuctx->unique_pmu != pmu)
501 continue; /* ensure we process each cpuctx once */
504 * perf_cgroup_events says at least one
505 * context on this CPU has cgroup events.
507 * ctx->nr_cgroups reports the number of cgroup
508 * events for a context.
510 if (cpuctx->ctx.nr_cgroups > 0) {
511 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
512 perf_pmu_disable(cpuctx->ctx.pmu);
514 if (mode & PERF_CGROUP_SWOUT) {
515 cpu_ctx_sched_out(cpuctx, EVENT_ALL);
517 * must not be done before ctxswout due
518 * to event_filter_match() in event_sched_out()
523 if (mode & PERF_CGROUP_SWIN) {
524 WARN_ON_ONCE(cpuctx->cgrp);
526 * set cgrp before ctxsw in to allow
527 * event_filter_match() to not have to pass
529 * we pass the cpuctx->ctx to perf_cgroup_from_task()
530 * because cgorup events are only per-cpu
532 cpuctx->cgrp = perf_cgroup_from_task(task, &cpuctx->ctx);
533 cpu_ctx_sched_in(cpuctx, EVENT_ALL, task);
535 perf_pmu_enable(cpuctx->ctx.pmu);
536 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
540 local_irq_restore(flags);
543 static inline void perf_cgroup_sched_out(struct task_struct *task,
544 struct task_struct *next)
546 struct perf_cgroup *cgrp1;
547 struct perf_cgroup *cgrp2 = NULL;
551 * we come here when we know perf_cgroup_events > 0
552 * we do not need to pass the ctx here because we know
553 * we are holding the rcu lock
555 cgrp1 = perf_cgroup_from_task(task, NULL);
558 * next is NULL when called from perf_event_enable_on_exec()
559 * that will systematically cause a cgroup_switch()
562 cgrp2 = perf_cgroup_from_task(next, NULL);
565 * only schedule out current cgroup events if we know
566 * that we are switching to a different cgroup. Otherwise,
567 * do no touch the cgroup events.
570 perf_cgroup_switch(task, PERF_CGROUP_SWOUT);
575 static inline void perf_cgroup_sched_in(struct task_struct *prev,
576 struct task_struct *task)
578 struct perf_cgroup *cgrp1;
579 struct perf_cgroup *cgrp2 = NULL;
583 * we come here when we know perf_cgroup_events > 0
584 * we do not need to pass the ctx here because we know
585 * we are holding the rcu lock
587 cgrp1 = perf_cgroup_from_task(task, NULL);
589 /* prev can never be NULL */
590 cgrp2 = perf_cgroup_from_task(prev, NULL);
593 * only need to schedule in cgroup events if we are changing
594 * cgroup during ctxsw. Cgroup events were not scheduled
595 * out of ctxsw out if that was not the case.
598 perf_cgroup_switch(task, PERF_CGROUP_SWIN);
603 static inline int perf_cgroup_connect(int fd, struct perf_event *event,
604 struct perf_event_attr *attr,
605 struct perf_event *group_leader)
607 struct perf_cgroup *cgrp;
608 struct cgroup_subsys_state *css;
609 struct fd f = fdget(fd);
615 css = css_tryget_online_from_dir(f.file->f_path.dentry,
616 &perf_event_cgrp_subsys);
622 cgrp = container_of(css, struct perf_cgroup, css);
626 * all events in a group must monitor
627 * the same cgroup because a task belongs
628 * to only one perf cgroup at a time
630 if (group_leader && group_leader->cgrp != cgrp) {
631 perf_detach_cgroup(event);
640 perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
642 struct perf_cgroup_info *t;
643 t = per_cpu_ptr(event->cgrp->info, event->cpu);
644 event->shadow_ctx_time = now - t->timestamp;
648 perf_cgroup_defer_enabled(struct perf_event *event)
651 * when the current task's perf cgroup does not match
652 * the event's, we need to remember to call the
653 * perf_mark_enable() function the first time a task with
654 * a matching perf cgroup is scheduled in.
656 if (is_cgroup_event(event) && !perf_cgroup_match(event))
657 event->cgrp_defer_enabled = 1;
661 perf_cgroup_mark_enabled(struct perf_event *event,
662 struct perf_event_context *ctx)
664 struct perf_event *sub;
665 u64 tstamp = perf_event_time(event);
667 if (!event->cgrp_defer_enabled)
670 event->cgrp_defer_enabled = 0;
672 event->tstamp_enabled = tstamp - event->total_time_enabled;
673 list_for_each_entry(sub, &event->sibling_list, group_entry) {
674 if (sub->state >= PERF_EVENT_STATE_INACTIVE) {
675 sub->tstamp_enabled = tstamp - sub->total_time_enabled;
676 sub->cgrp_defer_enabled = 0;
680 #else /* !CONFIG_CGROUP_PERF */
683 perf_cgroup_match(struct perf_event *event)
688 static inline void perf_detach_cgroup(struct perf_event *event)
691 static inline int is_cgroup_event(struct perf_event *event)
696 static inline u64 perf_cgroup_event_cgrp_time(struct perf_event *event)
701 static inline void update_cgrp_time_from_event(struct perf_event *event)
705 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx)
709 static inline void perf_cgroup_sched_out(struct task_struct *task,
710 struct task_struct *next)
714 static inline void perf_cgroup_sched_in(struct task_struct *prev,
715 struct task_struct *task)
719 static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event,
720 struct perf_event_attr *attr,
721 struct perf_event *group_leader)
727 perf_cgroup_set_timestamp(struct task_struct *task,
728 struct perf_event_context *ctx)
733 perf_cgroup_switch(struct task_struct *task, struct task_struct *next)
738 perf_cgroup_set_shadow_time(struct perf_event *event, u64 now)
742 static inline u64 perf_cgroup_event_time(struct perf_event *event)
748 perf_cgroup_defer_enabled(struct perf_event *event)
753 perf_cgroup_mark_enabled(struct perf_event *event,
754 struct perf_event_context *ctx)
760 * set default to be dependent on timer tick just
763 #define PERF_CPU_HRTIMER (1000 / HZ)
765 * function must be called with interrupts disbled
767 static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr)
769 struct perf_cpu_context *cpuctx;
772 WARN_ON(!irqs_disabled());
774 cpuctx = container_of(hr, struct perf_cpu_context, hrtimer);
775 rotations = perf_rotate_context(cpuctx);
777 raw_spin_lock(&cpuctx->hrtimer_lock);
779 hrtimer_forward_now(hr, cpuctx->hrtimer_interval);
781 cpuctx->hrtimer_active = 0;
782 raw_spin_unlock(&cpuctx->hrtimer_lock);
784 return rotations ? HRTIMER_RESTART : HRTIMER_NORESTART;
787 static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu)
789 struct hrtimer *timer = &cpuctx->hrtimer;
790 struct pmu *pmu = cpuctx->ctx.pmu;
793 /* no multiplexing needed for SW PMU */
794 if (pmu->task_ctx_nr == perf_sw_context)
798 * check default is sane, if not set then force to
799 * default interval (1/tick)
801 interval = pmu->hrtimer_interval_ms;
803 interval = pmu->hrtimer_interval_ms = PERF_CPU_HRTIMER;
805 cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * interval);
807 raw_spin_lock_init(&cpuctx->hrtimer_lock);
808 hrtimer_init(timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
809 timer->function = perf_mux_hrtimer_handler;
812 static int perf_mux_hrtimer_restart(struct perf_cpu_context *cpuctx)
814 struct hrtimer *timer = &cpuctx->hrtimer;
815 struct pmu *pmu = cpuctx->ctx.pmu;
819 if (pmu->task_ctx_nr == perf_sw_context)
822 raw_spin_lock_irqsave(&cpuctx->hrtimer_lock, flags);
823 if (!cpuctx->hrtimer_active) {
824 cpuctx->hrtimer_active = 1;
825 hrtimer_forward_now(timer, cpuctx->hrtimer_interval);
826 hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
828 raw_spin_unlock_irqrestore(&cpuctx->hrtimer_lock, flags);
833 void perf_pmu_disable(struct pmu *pmu)
835 int *count = this_cpu_ptr(pmu->pmu_disable_count);
837 pmu->pmu_disable(pmu);
840 void perf_pmu_enable(struct pmu *pmu)
842 int *count = this_cpu_ptr(pmu->pmu_disable_count);
844 pmu->pmu_enable(pmu);
847 static DEFINE_PER_CPU(struct list_head, active_ctx_list);
850 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
851 * perf_event_task_tick() are fully serialized because they're strictly cpu
852 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
853 * disabled, while perf_event_task_tick is called from IRQ context.
855 static void perf_event_ctx_activate(struct perf_event_context *ctx)
857 struct list_head *head = this_cpu_ptr(&active_ctx_list);
859 WARN_ON(!irqs_disabled());
861 WARN_ON(!list_empty(&ctx->active_ctx_list));
863 list_add(&ctx->active_ctx_list, head);
866 static void perf_event_ctx_deactivate(struct perf_event_context *ctx)
868 WARN_ON(!irqs_disabled());
870 WARN_ON(list_empty(&ctx->active_ctx_list));
872 list_del_init(&ctx->active_ctx_list);
875 static void get_ctx(struct perf_event_context *ctx)
877 WARN_ON(!atomic_inc_not_zero(&ctx->refcount));
880 static void free_ctx(struct rcu_head *head)
882 struct perf_event_context *ctx;
884 ctx = container_of(head, struct perf_event_context, rcu_head);
885 kfree(ctx->task_ctx_data);
889 static void put_ctx(struct perf_event_context *ctx)
891 if (atomic_dec_and_test(&ctx->refcount)) {
893 put_ctx(ctx->parent_ctx);
895 put_task_struct(ctx->task);
896 call_rcu(&ctx->rcu_head, free_ctx);
901 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
902 * perf_pmu_migrate_context() we need some magic.
904 * Those places that change perf_event::ctx will hold both
905 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
907 * Lock ordering is by mutex address. There are two other sites where
908 * perf_event_context::mutex nests and those are:
910 * - perf_event_exit_task_context() [ child , 0 ]
911 * __perf_event_exit_task()
913 * put_event() [ parent, 1 ]
915 * - perf_event_init_context() [ parent, 0 ]
916 * inherit_task_group()
921 * perf_try_init_event() [ child , 1 ]
923 * While it appears there is an obvious deadlock here -- the parent and child
924 * nesting levels are inverted between the two. This is in fact safe because
925 * life-time rules separate them. That is an exiting task cannot fork, and a
926 * spawning task cannot (yet) exit.
928 * But remember that that these are parent<->child context relations, and
929 * migration does not affect children, therefore these two orderings should not
932 * The change in perf_event::ctx does not affect children (as claimed above)
933 * because the sys_perf_event_open() case will install a new event and break
934 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
935 * concerned with cpuctx and that doesn't have children.
937 * The places that change perf_event::ctx will issue:
939 * perf_remove_from_context();
941 * perf_install_in_context();
943 * to affect the change. The remove_from_context() + synchronize_rcu() should
944 * quiesce the event, after which we can install it in the new location. This
945 * means that only external vectors (perf_fops, prctl) can perturb the event
946 * while in transit. Therefore all such accessors should also acquire
947 * perf_event_context::mutex to serialize against this.
949 * However; because event->ctx can change while we're waiting to acquire
950 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
955 * task_struct::perf_event_mutex
956 * perf_event_context::mutex
957 * perf_event_context::lock
958 * perf_event::child_mutex;
959 * perf_event::mmap_mutex
962 static struct perf_event_context *
963 perf_event_ctx_lock_nested(struct perf_event *event, int nesting)
965 struct perf_event_context *ctx;
969 ctx = ACCESS_ONCE(event->ctx);
970 if (!atomic_inc_not_zero(&ctx->refcount)) {
976 mutex_lock_nested(&ctx->mutex, nesting);
977 if (event->ctx != ctx) {
978 mutex_unlock(&ctx->mutex);
986 static inline struct perf_event_context *
987 perf_event_ctx_lock(struct perf_event *event)
989 return perf_event_ctx_lock_nested(event, 0);
992 static void perf_event_ctx_unlock(struct perf_event *event,
993 struct perf_event_context *ctx)
995 mutex_unlock(&ctx->mutex);
1000 * This must be done under the ctx->lock, such as to serialize against
1001 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1002 * calling scheduler related locks and ctx->lock nests inside those.
1004 static __must_check struct perf_event_context *
1005 unclone_ctx(struct perf_event_context *ctx)
1007 struct perf_event_context *parent_ctx = ctx->parent_ctx;
1009 lockdep_assert_held(&ctx->lock);
1012 ctx->parent_ctx = NULL;
1018 static u32 perf_event_pid(struct perf_event *event, struct task_struct *p)
1021 * only top level events have the pid namespace they were created in
1024 event = event->parent;
1026 return task_tgid_nr_ns(p, event->ns);
1029 static u32 perf_event_tid(struct perf_event *event, struct task_struct *p)
1032 * only top level events have the pid namespace they were created in
1035 event = event->parent;
1037 return task_pid_nr_ns(p, event->ns);
1041 * If we inherit events we want to return the parent event id
1044 static u64 primary_event_id(struct perf_event *event)
1049 id = event->parent->id;
1055 * Get the perf_event_context for a task and lock it.
1056 * This has to cope with with the fact that until it is locked,
1057 * the context could get moved to another task.
1059 static struct perf_event_context *
1060 perf_lock_task_context(struct task_struct *task, int ctxn, unsigned long *flags)
1062 struct perf_event_context *ctx;
1066 * One of the few rules of preemptible RCU is that one cannot do
1067 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1068 * part of the read side critical section was irqs-enabled -- see
1069 * rcu_read_unlock_special().
1071 * Since ctx->lock nests under rq->lock we must ensure the entire read
1072 * side critical section has interrupts disabled.
1074 local_irq_save(*flags);
1076 ctx = rcu_dereference(task->perf_event_ctxp[ctxn]);
1079 * If this context is a clone of another, it might
1080 * get swapped for another underneath us by
1081 * perf_event_task_sched_out, though the
1082 * rcu_read_lock() protects us from any context
1083 * getting freed. Lock the context and check if it
1084 * got swapped before we could get the lock, and retry
1085 * if so. If we locked the right context, then it
1086 * can't get swapped on us any more.
1088 raw_spin_lock(&ctx->lock);
1089 if (ctx != rcu_dereference(task->perf_event_ctxp[ctxn])) {
1090 raw_spin_unlock(&ctx->lock);
1092 local_irq_restore(*flags);
1096 if (!atomic_inc_not_zero(&ctx->refcount)) {
1097 raw_spin_unlock(&ctx->lock);
1103 local_irq_restore(*flags);
1108 * Get the context for a task and increment its pin_count so it
1109 * can't get swapped to another task. This also increments its
1110 * reference count so that the context can't get freed.
1112 static struct perf_event_context *
1113 perf_pin_task_context(struct task_struct *task, int ctxn)
1115 struct perf_event_context *ctx;
1116 unsigned long flags;
1118 ctx = perf_lock_task_context(task, ctxn, &flags);
1121 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1126 static void perf_unpin_context(struct perf_event_context *ctx)
1128 unsigned long flags;
1130 raw_spin_lock_irqsave(&ctx->lock, flags);
1132 raw_spin_unlock_irqrestore(&ctx->lock, flags);
1136 * Update the record of the current time in a context.
1138 static void update_context_time(struct perf_event_context *ctx)
1140 u64 now = perf_clock();
1142 ctx->time += now - ctx->timestamp;
1143 ctx->timestamp = now;
1146 static u64 perf_event_time(struct perf_event *event)
1148 struct perf_event_context *ctx = event->ctx;
1150 if (is_cgroup_event(event))
1151 return perf_cgroup_event_time(event);
1153 return ctx ? ctx->time : 0;
1157 * Update the total_time_enabled and total_time_running fields for a event.
1158 * The caller of this function needs to hold the ctx->lock.
1160 static void update_event_times(struct perf_event *event)
1162 struct perf_event_context *ctx = event->ctx;
1165 if (event->state < PERF_EVENT_STATE_INACTIVE ||
1166 event->group_leader->state < PERF_EVENT_STATE_INACTIVE)
1169 * in cgroup mode, time_enabled represents
1170 * the time the event was enabled AND active
1171 * tasks were in the monitored cgroup. This is
1172 * independent of the activity of the context as
1173 * there may be a mix of cgroup and non-cgroup events.
1175 * That is why we treat cgroup events differently
1178 if (is_cgroup_event(event))
1179 run_end = perf_cgroup_event_time(event);
1180 else if (ctx->is_active)
1181 run_end = ctx->time;
1183 run_end = event->tstamp_stopped;
1185 event->total_time_enabled = run_end - event->tstamp_enabled;
1187 if (event->state == PERF_EVENT_STATE_INACTIVE)
1188 run_end = event->tstamp_stopped;
1190 run_end = perf_event_time(event);
1192 event->total_time_running = run_end - event->tstamp_running;
1197 * Update total_time_enabled and total_time_running for all events in a group.
1199 static void update_group_times(struct perf_event *leader)
1201 struct perf_event *event;
1203 update_event_times(leader);
1204 list_for_each_entry(event, &leader->sibling_list, group_entry)
1205 update_event_times(event);
1208 static struct list_head *
1209 ctx_group_list(struct perf_event *event, struct perf_event_context *ctx)
1211 if (event->attr.pinned)
1212 return &ctx->pinned_groups;
1214 return &ctx->flexible_groups;
1218 * Add a event from the lists for its context.
1219 * Must be called with ctx->mutex and ctx->lock held.
1222 list_add_event(struct perf_event *event, struct perf_event_context *ctx)
1224 WARN_ON_ONCE(event->attach_state & PERF_ATTACH_CONTEXT);
1225 event->attach_state |= PERF_ATTACH_CONTEXT;
1228 * If we're a stand alone event or group leader, we go to the context
1229 * list, group events are kept attached to the group so that
1230 * perf_group_detach can, at all times, locate all siblings.
1232 if (event->group_leader == event) {
1233 struct list_head *list;
1235 if (is_software_event(event))
1236 event->group_flags |= PERF_GROUP_SOFTWARE;
1238 list = ctx_group_list(event, ctx);
1239 list_add_tail(&event->group_entry, list);
1242 if (is_cgroup_event(event))
1245 list_add_rcu(&event->event_entry, &ctx->event_list);
1247 if (event->attr.inherit_stat)
1254 * Initialize event state based on the perf_event_attr::disabled.
1256 static inline void perf_event__state_init(struct perf_event *event)
1258 event->state = event->attr.disabled ? PERF_EVENT_STATE_OFF :
1259 PERF_EVENT_STATE_INACTIVE;
1262 static void __perf_event_read_size(struct perf_event *event, int nr_siblings)
1264 int entry = sizeof(u64); /* value */
1268 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
1269 size += sizeof(u64);
1271 if (event->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
1272 size += sizeof(u64);
1274 if (event->attr.read_format & PERF_FORMAT_ID)
1275 entry += sizeof(u64);
1277 if (event->attr.read_format & PERF_FORMAT_GROUP) {
1279 size += sizeof(u64);
1283 event->read_size = size;
1286 static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
1288 struct perf_sample_data *data;
1291 if (sample_type & PERF_SAMPLE_IP)
1292 size += sizeof(data->ip);
1294 if (sample_type & PERF_SAMPLE_ADDR)
1295 size += sizeof(data->addr);
1297 if (sample_type & PERF_SAMPLE_PERIOD)
1298 size += sizeof(data->period);
1300 if (sample_type & PERF_SAMPLE_WEIGHT)
1301 size += sizeof(data->weight);
1303 if (sample_type & PERF_SAMPLE_READ)
1304 size += event->read_size;
1306 if (sample_type & PERF_SAMPLE_DATA_SRC)
1307 size += sizeof(data->data_src.val);
1309 if (sample_type & PERF_SAMPLE_TRANSACTION)
1310 size += sizeof(data->txn);
1312 event->header_size = size;
1316 * Called at perf_event creation and when events are attached/detached from a
1319 static void perf_event__header_size(struct perf_event *event)
1321 __perf_event_read_size(event,
1322 event->group_leader->nr_siblings);
1323 __perf_event_header_size(event, event->attr.sample_type);
1326 static void perf_event__id_header_size(struct perf_event *event)
1328 struct perf_sample_data *data;
1329 u64 sample_type = event->attr.sample_type;
1332 if (sample_type & PERF_SAMPLE_TID)
1333 size += sizeof(data->tid_entry);
1335 if (sample_type & PERF_SAMPLE_TIME)
1336 size += sizeof(data->time);
1338 if (sample_type & PERF_SAMPLE_IDENTIFIER)
1339 size += sizeof(data->id);
1341 if (sample_type & PERF_SAMPLE_ID)
1342 size += sizeof(data->id);
1344 if (sample_type & PERF_SAMPLE_STREAM_ID)
1345 size += sizeof(data->stream_id);
1347 if (sample_type & PERF_SAMPLE_CPU)
1348 size += sizeof(data->cpu_entry);
1350 event->id_header_size = size;
1353 static bool perf_event_validate_size(struct perf_event *event)
1356 * The values computed here will be over-written when we actually
1359 __perf_event_read_size(event, event->group_leader->nr_siblings + 1);
1360 __perf_event_header_size(event, event->attr.sample_type & ~PERF_SAMPLE_READ);
1361 perf_event__id_header_size(event);
1364 * Sum the lot; should not exceed the 64k limit we have on records.
1365 * Conservative limit to allow for callchains and other variable fields.
1367 if (event->read_size + event->header_size +
1368 event->id_header_size + sizeof(struct perf_event_header) >= 16*1024)
1374 static void perf_group_attach(struct perf_event *event)
1376 struct perf_event *group_leader = event->group_leader, *pos;
1379 * We can have double attach due to group movement in perf_event_open.
1381 if (event->attach_state & PERF_ATTACH_GROUP)
1384 event->attach_state |= PERF_ATTACH_GROUP;
1386 if (group_leader == event)
1389 WARN_ON_ONCE(group_leader->ctx != event->ctx);
1391 if (group_leader->group_flags & PERF_GROUP_SOFTWARE &&
1392 !is_software_event(event))
1393 group_leader->group_flags &= ~PERF_GROUP_SOFTWARE;
1395 list_add_tail(&event->group_entry, &group_leader->sibling_list);
1396 group_leader->nr_siblings++;
1398 perf_event__header_size(group_leader);
1400 list_for_each_entry(pos, &group_leader->sibling_list, group_entry)
1401 perf_event__header_size(pos);
1405 * Remove a event from the lists for its context.
1406 * Must be called with ctx->mutex and ctx->lock held.
1409 list_del_event(struct perf_event *event, struct perf_event_context *ctx)
1411 struct perf_cpu_context *cpuctx;
1413 WARN_ON_ONCE(event->ctx != ctx);
1414 lockdep_assert_held(&ctx->lock);
1417 * We can have double detach due to exit/hot-unplug + close.
1419 if (!(event->attach_state & PERF_ATTACH_CONTEXT))
1422 event->attach_state &= ~PERF_ATTACH_CONTEXT;
1424 if (is_cgroup_event(event)) {
1426 cpuctx = __get_cpu_context(ctx);
1428 * if there are no more cgroup events
1429 * then cler cgrp to avoid stale pointer
1430 * in update_cgrp_time_from_cpuctx()
1432 if (!ctx->nr_cgroups)
1433 cpuctx->cgrp = NULL;
1437 if (event->attr.inherit_stat)
1440 list_del_rcu(&event->event_entry);
1442 if (event->group_leader == event)
1443 list_del_init(&event->group_entry);
1445 update_group_times(event);
1448 * If event was in error state, then keep it
1449 * that way, otherwise bogus counts will be
1450 * returned on read(). The only way to get out
1451 * of error state is by explicit re-enabling
1454 if (event->state > PERF_EVENT_STATE_OFF)
1455 event->state = PERF_EVENT_STATE_OFF;
1460 static void perf_group_detach(struct perf_event *event)
1462 struct perf_event *sibling, *tmp;
1463 struct list_head *list = NULL;
1466 * We can have double detach due to exit/hot-unplug + close.
1468 if (!(event->attach_state & PERF_ATTACH_GROUP))
1471 event->attach_state &= ~PERF_ATTACH_GROUP;
1474 * If this is a sibling, remove it from its group.
1476 if (event->group_leader != event) {
1477 list_del_init(&event->group_entry);
1478 event->group_leader->nr_siblings--;
1482 if (!list_empty(&event->group_entry))
1483 list = &event->group_entry;
1486 * If this was a group event with sibling events then
1487 * upgrade the siblings to singleton events by adding them
1488 * to whatever list we are on.
1490 list_for_each_entry_safe(sibling, tmp, &event->sibling_list, group_entry) {
1492 list_move_tail(&sibling->group_entry, list);
1493 sibling->group_leader = sibling;
1495 /* Inherit group flags from the previous leader */
1496 sibling->group_flags = event->group_flags;
1498 WARN_ON_ONCE(sibling->ctx != event->ctx);
1502 perf_event__header_size(event->group_leader);
1504 list_for_each_entry(tmp, &event->group_leader->sibling_list, group_entry)
1505 perf_event__header_size(tmp);
1509 * User event without the task.
1511 static bool is_orphaned_event(struct perf_event *event)
1513 return event && !is_kernel_event(event) && !event->owner;
1517 * Event has a parent but parent's task finished and it's
1518 * alive only because of children holding refference.
1520 static bool is_orphaned_child(struct perf_event *event)
1522 return is_orphaned_event(event->parent);
1525 static void orphans_remove_work(struct work_struct *work);
1527 static void schedule_orphans_remove(struct perf_event_context *ctx)
1529 if (!ctx->task || ctx->orphans_remove_sched || !perf_wq)
1532 if (queue_delayed_work(perf_wq, &ctx->orphans_remove, 1)) {
1534 ctx->orphans_remove_sched = true;
1538 static int __init perf_workqueue_init(void)
1540 perf_wq = create_singlethread_workqueue("perf");
1541 WARN(!perf_wq, "failed to create perf workqueue\n");
1542 return perf_wq ? 0 : -1;
1545 core_initcall(perf_workqueue_init);
1547 static inline int __pmu_filter_match(struct perf_event *event)
1549 struct pmu *pmu = event->pmu;
1550 return pmu->filter_match ? pmu->filter_match(event) : 1;
1554 * Check whether we should attempt to schedule an event group based on
1555 * PMU-specific filtering. An event group can consist of HW and SW events,
1556 * potentially with a SW leader, so we must check all the filters, to
1557 * determine whether a group is schedulable:
1559 static inline int pmu_filter_match(struct perf_event *event)
1561 struct perf_event *child;
1563 if (!__pmu_filter_match(event))
1566 list_for_each_entry(child, &event->sibling_list, group_entry) {
1567 if (!__pmu_filter_match(child))
1575 event_filter_match(struct perf_event *event)
1577 return (event->cpu == -1 || event->cpu == smp_processor_id())
1578 && perf_cgroup_match(event) && pmu_filter_match(event);
1582 event_sched_out(struct perf_event *event,
1583 struct perf_cpu_context *cpuctx,
1584 struct perf_event_context *ctx)
1586 u64 tstamp = perf_event_time(event);
1589 WARN_ON_ONCE(event->ctx != ctx);
1590 lockdep_assert_held(&ctx->lock);
1593 * An event which could not be activated because of
1594 * filter mismatch still needs to have its timings
1595 * maintained, otherwise bogus information is return
1596 * via read() for time_enabled, time_running:
1598 if (event->state == PERF_EVENT_STATE_INACTIVE
1599 && !event_filter_match(event)) {
1600 delta = tstamp - event->tstamp_stopped;
1601 event->tstamp_running += delta;
1602 event->tstamp_stopped = tstamp;
1605 if (event->state != PERF_EVENT_STATE_ACTIVE)
1608 perf_pmu_disable(event->pmu);
1610 event->tstamp_stopped = tstamp;
1611 event->pmu->del(event, 0);
1613 event->state = PERF_EVENT_STATE_INACTIVE;
1614 if (event->pending_disable) {
1615 event->pending_disable = 0;
1616 event->state = PERF_EVENT_STATE_OFF;
1619 if (!is_software_event(event))
1620 cpuctx->active_oncpu--;
1621 if (!--ctx->nr_active)
1622 perf_event_ctx_deactivate(ctx);
1623 if (event->attr.freq && event->attr.sample_freq)
1625 if (event->attr.exclusive || !cpuctx->active_oncpu)
1626 cpuctx->exclusive = 0;
1628 if (is_orphaned_child(event))
1629 schedule_orphans_remove(ctx);
1631 perf_pmu_enable(event->pmu);
1635 group_sched_out(struct perf_event *group_event,
1636 struct perf_cpu_context *cpuctx,
1637 struct perf_event_context *ctx)
1639 struct perf_event *event;
1640 int state = group_event->state;
1642 event_sched_out(group_event, cpuctx, ctx);
1645 * Schedule out siblings (if any):
1647 list_for_each_entry(event, &group_event->sibling_list, group_entry)
1648 event_sched_out(event, cpuctx, ctx);
1650 if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive)
1651 cpuctx->exclusive = 0;
1654 struct remove_event {
1655 struct perf_event *event;
1660 * Cross CPU call to remove a performance event
1662 * We disable the event on the hardware level first. After that we
1663 * remove it from the context list.
1665 static int __perf_remove_from_context(void *info)
1667 struct remove_event *re = info;
1668 struct perf_event *event = re->event;
1669 struct perf_event_context *ctx = event->ctx;
1670 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
1672 raw_spin_lock(&ctx->lock);
1673 event_sched_out(event, cpuctx, ctx);
1674 if (re->detach_group)
1675 perf_group_detach(event);
1676 list_del_event(event, ctx);
1677 if (!ctx->nr_events && cpuctx->task_ctx == ctx) {
1679 cpuctx->task_ctx = NULL;
1681 raw_spin_unlock(&ctx->lock);
1688 * Remove the event from a task's (or a CPU's) list of events.
1690 * CPU events are removed with a smp call. For task events we only
1691 * call when the task is on a CPU.
1693 * If event->ctx is a cloned context, callers must make sure that
1694 * every task struct that event->ctx->task could possibly point to
1695 * remains valid. This is OK when called from perf_release since
1696 * that only calls us on the top-level context, which can't be a clone.
1697 * When called from perf_event_exit_task, it's OK because the
1698 * context has been detached from its task.
1700 static void perf_remove_from_context(struct perf_event *event, bool detach_group)
1702 struct perf_event_context *ctx = event->ctx;
1703 struct task_struct *task = ctx->task;
1704 struct remove_event re = {
1706 .detach_group = detach_group,
1709 lockdep_assert_held(&ctx->mutex);
1713 * Per cpu events are removed via an smp call. The removal can
1714 * fail if the CPU is currently offline, but in that case we
1715 * already called __perf_remove_from_context from
1716 * perf_event_exit_cpu.
1718 cpu_function_call(event->cpu, __perf_remove_from_context, &re);
1723 if (!task_function_call(task, __perf_remove_from_context, &re))
1726 raw_spin_lock_irq(&ctx->lock);
1728 * If we failed to find a running task, but find the context active now
1729 * that we've acquired the ctx->lock, retry.
1731 if (ctx->is_active) {
1732 raw_spin_unlock_irq(&ctx->lock);
1734 * Reload the task pointer, it might have been changed by
1735 * a concurrent perf_event_context_sched_out().
1742 * Since the task isn't running, its safe to remove the event, us
1743 * holding the ctx->lock ensures the task won't get scheduled in.
1746 perf_group_detach(event);
1747 list_del_event(event, ctx);
1748 raw_spin_unlock_irq(&ctx->lock);
1752 * Cross CPU call to disable a performance event
1754 int __perf_event_disable(void *info)
1756 struct perf_event *event = info;
1757 struct perf_event_context *ctx = event->ctx;
1758 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
1761 * If this is a per-task event, need to check whether this
1762 * event's task is the current task on this cpu.
1764 * Can trigger due to concurrent perf_event_context_sched_out()
1765 * flipping contexts around.
1767 if (ctx->task && cpuctx->task_ctx != ctx)
1770 raw_spin_lock(&ctx->lock);
1773 * If the event is on, turn it off.
1774 * If it is in error state, leave it in error state.
1776 if (event->state >= PERF_EVENT_STATE_INACTIVE) {
1777 update_context_time(ctx);
1778 update_cgrp_time_from_event(event);
1779 update_group_times(event);
1780 if (event == event->group_leader)
1781 group_sched_out(event, cpuctx, ctx);
1783 event_sched_out(event, cpuctx, ctx);
1784 event->state = PERF_EVENT_STATE_OFF;
1787 raw_spin_unlock(&ctx->lock);
1795 * If event->ctx is a cloned context, callers must make sure that
1796 * every task struct that event->ctx->task could possibly point to
1797 * remains valid. This condition is satisifed when called through
1798 * perf_event_for_each_child or perf_event_for_each because they
1799 * hold the top-level event's child_mutex, so any descendant that
1800 * goes to exit will block in sync_child_event.
1801 * When called from perf_pending_event it's OK because event->ctx
1802 * is the current context on this CPU and preemption is disabled,
1803 * hence we can't get into perf_event_task_sched_out for this context.
1805 static void _perf_event_disable(struct perf_event *event)
1807 struct perf_event_context *ctx = event->ctx;
1808 struct task_struct *task = ctx->task;
1812 * Disable the event on the cpu that it's on
1814 cpu_function_call(event->cpu, __perf_event_disable, event);
1819 if (!task_function_call(task, __perf_event_disable, event))
1822 raw_spin_lock_irq(&ctx->lock);
1824 * If the event is still active, we need to retry the cross-call.
1826 if (event->state == PERF_EVENT_STATE_ACTIVE) {
1827 raw_spin_unlock_irq(&ctx->lock);
1829 * Reload the task pointer, it might have been changed by
1830 * a concurrent perf_event_context_sched_out().
1837 * Since we have the lock this context can't be scheduled
1838 * in, so we can change the state safely.
1840 if (event->state == PERF_EVENT_STATE_INACTIVE) {
1841 update_group_times(event);
1842 event->state = PERF_EVENT_STATE_OFF;
1844 raw_spin_unlock_irq(&ctx->lock);
1848 * Strictly speaking kernel users cannot create groups and therefore this
1849 * interface does not need the perf_event_ctx_lock() magic.
1851 void perf_event_disable(struct perf_event *event)
1853 struct perf_event_context *ctx;
1855 ctx = perf_event_ctx_lock(event);
1856 _perf_event_disable(event);
1857 perf_event_ctx_unlock(event, ctx);
1859 EXPORT_SYMBOL_GPL(perf_event_disable);
1861 static void perf_set_shadow_time(struct perf_event *event,
1862 struct perf_event_context *ctx,
1866 * use the correct time source for the time snapshot
1868 * We could get by without this by leveraging the
1869 * fact that to get to this function, the caller
1870 * has most likely already called update_context_time()
1871 * and update_cgrp_time_xx() and thus both timestamp
1872 * are identical (or very close). Given that tstamp is,
1873 * already adjusted for cgroup, we could say that:
1874 * tstamp - ctx->timestamp
1876 * tstamp - cgrp->timestamp.
1878 * Then, in perf_output_read(), the calculation would
1879 * work with no changes because:
1880 * - event is guaranteed scheduled in
1881 * - no scheduled out in between
1882 * - thus the timestamp would be the same
1884 * But this is a bit hairy.
1886 * So instead, we have an explicit cgroup call to remain
1887 * within the time time source all along. We believe it
1888 * is cleaner and simpler to understand.
1890 if (is_cgroup_event(event))
1891 perf_cgroup_set_shadow_time(event, tstamp);
1893 event->shadow_ctx_time = tstamp - ctx->timestamp;
1896 #define MAX_INTERRUPTS (~0ULL)
1898 static void perf_log_throttle(struct perf_event *event, int enable);
1899 static void perf_log_itrace_start(struct perf_event *event);
1902 event_sched_in(struct perf_event *event,
1903 struct perf_cpu_context *cpuctx,
1904 struct perf_event_context *ctx)
1906 u64 tstamp = perf_event_time(event);
1909 lockdep_assert_held(&ctx->lock);
1911 if (event->state <= PERF_EVENT_STATE_OFF)
1914 WRITE_ONCE(event->oncpu, smp_processor_id());
1916 * Order event::oncpu write to happen before the ACTIVE state
1920 WRITE_ONCE(event->state, PERF_EVENT_STATE_ACTIVE);
1923 * Unthrottle events, since we scheduled we might have missed several
1924 * ticks already, also for a heavily scheduling task there is little
1925 * guarantee it'll get a tick in a timely manner.
1927 if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
1928 perf_log_throttle(event, 1);
1929 event->hw.interrupts = 0;
1933 * The new state must be visible before we turn it on in the hardware:
1937 perf_pmu_disable(event->pmu);
1939 perf_set_shadow_time(event, ctx, tstamp);
1941 perf_log_itrace_start(event);
1943 if (event->pmu->add(event, PERF_EF_START)) {
1944 event->state = PERF_EVENT_STATE_INACTIVE;
1950 event->tstamp_running += tstamp - event->tstamp_stopped;
1952 if (!is_software_event(event))
1953 cpuctx->active_oncpu++;
1954 if (!ctx->nr_active++)
1955 perf_event_ctx_activate(ctx);
1956 if (event->attr.freq && event->attr.sample_freq)
1959 if (event->attr.exclusive)
1960 cpuctx->exclusive = 1;
1962 if (is_orphaned_child(event))
1963 schedule_orphans_remove(ctx);
1966 perf_pmu_enable(event->pmu);
1972 group_sched_in(struct perf_event *group_event,
1973 struct perf_cpu_context *cpuctx,
1974 struct perf_event_context *ctx)
1976 struct perf_event *event, *partial_group = NULL;
1977 struct pmu *pmu = ctx->pmu;
1978 u64 now = ctx->time;
1979 bool simulate = false;
1981 if (group_event->state == PERF_EVENT_STATE_OFF)
1984 pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
1986 if (event_sched_in(group_event, cpuctx, ctx)) {
1987 pmu->cancel_txn(pmu);
1988 perf_mux_hrtimer_restart(cpuctx);
1993 * Schedule in siblings as one group (if any):
1995 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
1996 if (event_sched_in(event, cpuctx, ctx)) {
1997 partial_group = event;
2002 if (!pmu->commit_txn(pmu))
2007 * Groups can be scheduled in as one unit only, so undo any
2008 * partial group before returning:
2009 * The events up to the failed event are scheduled out normally,
2010 * tstamp_stopped will be updated.
2012 * The failed events and the remaining siblings need to have
2013 * their timings updated as if they had gone thru event_sched_in()
2014 * and event_sched_out(). This is required to get consistent timings
2015 * across the group. This also takes care of the case where the group
2016 * could never be scheduled by ensuring tstamp_stopped is set to mark
2017 * the time the event was actually stopped, such that time delta
2018 * calculation in update_event_times() is correct.
2020 list_for_each_entry(event, &group_event->sibling_list, group_entry) {
2021 if (event == partial_group)
2025 event->tstamp_running += now - event->tstamp_stopped;
2026 event->tstamp_stopped = now;
2028 event_sched_out(event, cpuctx, ctx);
2031 event_sched_out(group_event, cpuctx, ctx);
2033 pmu->cancel_txn(pmu);
2035 perf_mux_hrtimer_restart(cpuctx);
2041 * Work out whether we can put this event group on the CPU now.
2043 static int group_can_go_on(struct perf_event *event,
2044 struct perf_cpu_context *cpuctx,
2048 * Groups consisting entirely of software events can always go on.
2050 if (event->group_flags & PERF_GROUP_SOFTWARE)
2053 * If an exclusive group is already on, no other hardware
2056 if (cpuctx->exclusive)
2059 * If this group is exclusive and there are already
2060 * events on the CPU, it can't go on.
2062 if (event->attr.exclusive && cpuctx->active_oncpu)
2065 * Otherwise, try to add it if all previous groups were able
2071 static void add_event_to_ctx(struct perf_event *event,
2072 struct perf_event_context *ctx)
2074 u64 tstamp = perf_event_time(event);
2076 list_add_event(event, ctx);
2077 perf_group_attach(event);
2078 event->tstamp_enabled = tstamp;
2079 event->tstamp_running = tstamp;
2080 event->tstamp_stopped = tstamp;
2083 static void task_ctx_sched_out(struct perf_event_context *ctx);
2085 ctx_sched_in(struct perf_event_context *ctx,
2086 struct perf_cpu_context *cpuctx,
2087 enum event_type_t event_type,
2088 struct task_struct *task);
2090 static void perf_event_sched_in(struct perf_cpu_context *cpuctx,
2091 struct perf_event_context *ctx,
2092 struct task_struct *task)
2094 cpu_ctx_sched_in(cpuctx, EVENT_PINNED, task);
2096 ctx_sched_in(ctx, cpuctx, EVENT_PINNED, task);
2097 cpu_ctx_sched_in(cpuctx, EVENT_FLEXIBLE, task);
2099 ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE, task);
2103 * Cross CPU call to install and enable a performance event
2105 * Must be called with ctx->mutex held
2107 static int __perf_install_in_context(void *info)
2109 struct perf_event *event = info;
2110 struct perf_event_context *ctx = event->ctx;
2111 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
2112 struct perf_event_context *task_ctx = cpuctx->task_ctx;
2113 struct task_struct *task = current;
2115 perf_ctx_lock(cpuctx, task_ctx);
2116 perf_pmu_disable(cpuctx->ctx.pmu);
2119 * If there was an active task_ctx schedule it out.
2122 task_ctx_sched_out(task_ctx);
2125 * If the context we're installing events in is not the
2126 * active task_ctx, flip them.
2128 if (ctx->task && task_ctx != ctx) {
2130 raw_spin_unlock(&task_ctx->lock);
2131 raw_spin_lock(&ctx->lock);
2136 cpuctx->task_ctx = task_ctx;
2137 task = task_ctx->task;
2140 cpu_ctx_sched_out(cpuctx, EVENT_ALL);
2142 update_context_time(ctx);
2144 * update cgrp time only if current cgrp
2145 * matches event->cgrp. Must be done before
2146 * calling add_event_to_ctx()
2148 update_cgrp_time_from_event(event);
2150 add_event_to_ctx(event, ctx);
2153 * Schedule everything back in
2155 perf_event_sched_in(cpuctx, task_ctx, task);
2157 perf_pmu_enable(cpuctx->ctx.pmu);
2158 perf_ctx_unlock(cpuctx, task_ctx);
2164 * Attach a performance event to a context
2166 * First we add the event to the list with the hardware enable bit
2167 * in event->hw_config cleared.
2169 * If the event is attached to a task which is on a CPU we use a smp
2170 * call to enable it in the task context. The task might have been
2171 * scheduled away, but we check this in the smp call again.
2174 perf_install_in_context(struct perf_event_context *ctx,
2175 struct perf_event *event,
2178 struct task_struct *task = ctx->task;
2180 lockdep_assert_held(&ctx->mutex);
2183 if (event->cpu != -1)
2188 * Per cpu events are installed via an smp call and
2189 * the install is always successful.
2191 cpu_function_call(cpu, __perf_install_in_context, event);
2196 if (!task_function_call(task, __perf_install_in_context, event))
2199 raw_spin_lock_irq(&ctx->lock);
2201 * If we failed to find a running task, but find the context active now
2202 * that we've acquired the ctx->lock, retry.
2204 if (ctx->is_active) {
2205 raw_spin_unlock_irq(&ctx->lock);
2207 * Reload the task pointer, it might have been changed by
2208 * a concurrent perf_event_context_sched_out().
2215 * Since the task isn't running, its safe to add the event, us holding
2216 * the ctx->lock ensures the task won't get scheduled in.
2218 add_event_to_ctx(event, ctx);
2219 raw_spin_unlock_irq(&ctx->lock);
2223 * Put a event into inactive state and update time fields.
2224 * Enabling the leader of a group effectively enables all
2225 * the group members that aren't explicitly disabled, so we
2226 * have to update their ->tstamp_enabled also.
2227 * Note: this works for group members as well as group leaders
2228 * since the non-leader members' sibling_lists will be empty.
2230 static void __perf_event_mark_enabled(struct perf_event *event)
2232 struct perf_event *sub;
2233 u64 tstamp = perf_event_time(event);
2235 event->state = PERF_EVENT_STATE_INACTIVE;
2236 event->tstamp_enabled = tstamp - event->total_time_enabled;
2237 list_for_each_entry(sub, &event->sibling_list, group_entry) {
2238 if (sub->state >= PERF_EVENT_STATE_INACTIVE)
2239 sub->tstamp_enabled = tstamp - sub->total_time_enabled;
2244 * Cross CPU call to enable a performance event
2246 static int __perf_event_enable(void *info)
2248 struct perf_event *event = info;
2249 struct perf_event_context *ctx = event->ctx;
2250 struct perf_event *leader = event->group_leader;
2251 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
2255 * There's a time window between 'ctx->is_active' check
2256 * in perf_event_enable function and this place having:
2258 * - ctx->lock unlocked
2260 * where the task could be killed and 'ctx' deactivated
2261 * by perf_event_exit_task.
2263 if (!ctx->is_active)
2266 raw_spin_lock(&ctx->lock);
2267 update_context_time(ctx);
2269 if (event->state >= PERF_EVENT_STATE_INACTIVE)
2273 * set current task's cgroup time reference point
2275 perf_cgroup_set_timestamp(current, ctx);
2277 __perf_event_mark_enabled(event);
2279 if (!event_filter_match(event)) {
2280 if (is_cgroup_event(event))
2281 perf_cgroup_defer_enabled(event);
2286 * If the event is in a group and isn't the group leader,
2287 * then don't put it on unless the group is on.
2289 if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
2292 if (!group_can_go_on(event, cpuctx, 1)) {
2295 if (event == leader)
2296 err = group_sched_in(event, cpuctx, ctx);
2298 err = event_sched_in(event, cpuctx, ctx);
2303 * If this event can't go on and it's part of a
2304 * group, then the whole group has to come off.
2306 if (leader != event) {
2307 group_sched_out(leader, cpuctx, ctx);
2308 perf_mux_hrtimer_restart(cpuctx);
2310 if (leader->attr.pinned) {
2311 update_group_times(leader);
2312 leader->state = PERF_EVENT_STATE_ERROR;
2317 raw_spin_unlock(&ctx->lock);
2325 * If event->ctx is a cloned context, callers must make sure that
2326 * every task struct that event->ctx->task could possibly point to
2327 * remains valid. This condition is satisfied when called through
2328 * perf_event_for_each_child or perf_event_for_each as described
2329 * for perf_event_disable.
2331 static void _perf_event_enable(struct perf_event *event)
2333 struct perf_event_context *ctx = event->ctx;
2334 struct task_struct *task = ctx->task;
2338 * Enable the event on the cpu that it's on
2340 cpu_function_call(event->cpu, __perf_event_enable, event);
2344 raw_spin_lock_irq(&ctx->lock);
2345 if (event->state >= PERF_EVENT_STATE_INACTIVE)
2349 * If the event is in error state, clear that first.
2350 * That way, if we see the event in error state below, we
2351 * know that it has gone back into error state, as distinct
2352 * from the task having been scheduled away before the
2353 * cross-call arrived.
2355 if (event->state == PERF_EVENT_STATE_ERROR)
2356 event->state = PERF_EVENT_STATE_OFF;
2359 if (!ctx->is_active) {
2360 __perf_event_mark_enabled(event);
2364 raw_spin_unlock_irq(&ctx->lock);
2366 if (!task_function_call(task, __perf_event_enable, event))
2369 raw_spin_lock_irq(&ctx->lock);
2372 * If the context is active and the event is still off,
2373 * we need to retry the cross-call.
2375 if (ctx->is_active && event->state == PERF_EVENT_STATE_OFF) {
2377 * task could have been flipped by a concurrent
2378 * perf_event_context_sched_out()
2385 raw_spin_unlock_irq(&ctx->lock);
2389 * See perf_event_disable();
2391 void perf_event_enable(struct perf_event *event)
2393 struct perf_event_context *ctx;
2395 ctx = perf_event_ctx_lock(event);
2396 _perf_event_enable(event);
2397 perf_event_ctx_unlock(event, ctx);
2399 EXPORT_SYMBOL_GPL(perf_event_enable);
2401 static int __perf_event_stop(void *info)
2403 struct perf_event *event = info;
2405 /* for AUX events, our job is done if the event is already inactive */
2406 if (READ_ONCE(event->state) != PERF_EVENT_STATE_ACTIVE)
2409 /* matches smp_wmb() in event_sched_in() */
2413 * There is a window with interrupts enabled before we get here,
2414 * so we need to check again lest we try to stop another CPU's event.
2416 if (READ_ONCE(event->oncpu) != smp_processor_id())
2419 event->pmu->stop(event, PERF_EF_UPDATE);
2424 static int _perf_event_refresh(struct perf_event *event, int refresh)
2427 * not supported on inherited events
2429 if (event->attr.inherit || !is_sampling_event(event))
2432 atomic_add(refresh, &event->event_limit);
2433 _perf_event_enable(event);
2439 * See perf_event_disable()
2441 int perf_event_refresh(struct perf_event *event, int refresh)
2443 struct perf_event_context *ctx;
2446 ctx = perf_event_ctx_lock(event);
2447 ret = _perf_event_refresh(event, refresh);
2448 perf_event_ctx_unlock(event, ctx);
2452 EXPORT_SYMBOL_GPL(perf_event_refresh);
2454 static void ctx_sched_out(struct perf_event_context *ctx,
2455 struct perf_cpu_context *cpuctx,
2456 enum event_type_t event_type)
2458 struct perf_event *event;
2459 int is_active = ctx->is_active;
2461 ctx->is_active &= ~event_type;
2462 if (likely(!ctx->nr_events))
2465 update_context_time(ctx);
2466 update_cgrp_time_from_cpuctx(cpuctx);
2467 if (!ctx->nr_active)
2470 perf_pmu_disable(ctx->pmu);
2471 if ((is_active & EVENT_PINNED) && (event_type & EVENT_PINNED)) {
2472 list_for_each_entry(event, &ctx->pinned_groups, group_entry)
2473 group_sched_out(event, cpuctx, ctx);
2476 if ((is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE)) {
2477 list_for_each_entry(event, &ctx->flexible_groups, group_entry)
2478 group_sched_out(event, cpuctx, ctx);
2480 perf_pmu_enable(ctx->pmu);
2484 * Test whether two contexts are equivalent, i.e. whether they have both been
2485 * cloned from the same version of the same context.
2487 * Equivalence is measured using a generation number in the context that is
2488 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2489 * and list_del_event().
2491 static int context_equiv(struct perf_event_context *ctx1,
2492 struct perf_event_context *ctx2)
2494 lockdep_assert_held(&ctx1->lock);
2495 lockdep_assert_held(&ctx2->lock);
2497 /* Pinning disables the swap optimization */
2498 if (ctx1->pin_count || ctx2->pin_count)
2501 /* If ctx1 is the parent of ctx2 */
2502 if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen)
2505 /* If ctx2 is the parent of ctx1 */
2506 if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation)
2510 * If ctx1 and ctx2 have the same parent; we flatten the parent
2511 * hierarchy, see perf_event_init_context().
2513 if (ctx1->parent_ctx && ctx1->parent_ctx == ctx2->parent_ctx &&
2514 ctx1->parent_gen == ctx2->parent_gen)
2521 static void __perf_event_sync_stat(struct perf_event *event,
2522 struct perf_event *next_event)
2526 if (!event->attr.inherit_stat)
2530 * Update the event value, we cannot use perf_event_read()
2531 * because we're in the middle of a context switch and have IRQs
2532 * disabled, which upsets smp_call_function_single(), however
2533 * we know the event must be on the current CPU, therefore we
2534 * don't need to use it.
2536 switch (event->state) {
2537 case PERF_EVENT_STATE_ACTIVE:
2538 event->pmu->read(event);
2541 case PERF_EVENT_STATE_INACTIVE:
2542 update_event_times(event);
2550 * In order to keep per-task stats reliable we need to flip the event
2551 * values when we flip the contexts.
2553 value = local64_read(&next_event->count);
2554 value = local64_xchg(&event->count, value);
2555 local64_set(&next_event->count, value);
2557 swap(event->total_time_enabled, next_event->total_time_enabled);
2558 swap(event->total_time_running, next_event->total_time_running);
2561 * Since we swizzled the values, update the user visible data too.
2563 perf_event_update_userpage(event);
2564 perf_event_update_userpage(next_event);
2567 static void perf_event_sync_stat(struct perf_event_context *ctx,
2568 struct perf_event_context *next_ctx)
2570 struct perf_event *event, *next_event;
2575 update_context_time(ctx);
2577 event = list_first_entry(&ctx->event_list,
2578 struct perf_event, event_entry);
2580 next_event = list_first_entry(&next_ctx->event_list,
2581 struct perf_event, event_entry);
2583 while (&event->event_entry != &ctx->event_list &&
2584 &next_event->event_entry != &next_ctx->event_list) {
2586 __perf_event_sync_stat(event, next_event);
2588 event = list_next_entry(event, event_entry);
2589 next_event = list_next_entry(next_event, event_entry);
2593 static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
2594 struct task_struct *next)
2596 struct perf_event_context *ctx = task->perf_event_ctxp[ctxn];
2597 struct perf_event_context *next_ctx;
2598 struct perf_event_context *parent, *next_parent;
2599 struct perf_cpu_context *cpuctx;
2605 cpuctx = __get_cpu_context(ctx);
2606 if (!cpuctx->task_ctx)
2610 next_ctx = next->perf_event_ctxp[ctxn];
2614 parent = rcu_dereference(ctx->parent_ctx);
2615 next_parent = rcu_dereference(next_ctx->parent_ctx);
2617 /* If neither context have a parent context; they cannot be clones. */
2618 if (!parent && !next_parent)
2621 if (next_parent == ctx || next_ctx == parent || next_parent == parent) {
2623 * Looks like the two contexts are clones, so we might be
2624 * able to optimize the context switch. We lock both
2625 * contexts and check that they are clones under the
2626 * lock (including re-checking that neither has been
2627 * uncloned in the meantime). It doesn't matter which
2628 * order we take the locks because no other cpu could
2629 * be trying to lock both of these tasks.
2631 raw_spin_lock(&ctx->lock);
2632 raw_spin_lock_nested(&next_ctx->lock, SINGLE_DEPTH_NESTING);
2633 if (context_equiv(ctx, next_ctx)) {
2635 * XXX do we need a memory barrier of sorts
2636 * wrt to rcu_dereference() of perf_event_ctxp
2638 task->perf_event_ctxp[ctxn] = next_ctx;
2639 next->perf_event_ctxp[ctxn] = ctx;
2641 next_ctx->task = task;
2643 swap(ctx->task_ctx_data, next_ctx->task_ctx_data);
2647 perf_event_sync_stat(ctx, next_ctx);
2649 raw_spin_unlock(&next_ctx->lock);
2650 raw_spin_unlock(&ctx->lock);
2656 raw_spin_lock(&ctx->lock);
2657 ctx_sched_out(ctx, cpuctx, EVENT_ALL);
2658 cpuctx->task_ctx = NULL;
2659 raw_spin_unlock(&ctx->lock);
2663 void perf_sched_cb_dec(struct pmu *pmu)
2665 this_cpu_dec(perf_sched_cb_usages);
2668 void perf_sched_cb_inc(struct pmu *pmu)
2670 this_cpu_inc(perf_sched_cb_usages);
2674 * This function provides the context switch callback to the lower code
2675 * layer. It is invoked ONLY when the context switch callback is enabled.
2677 static void perf_pmu_sched_task(struct task_struct *prev,
2678 struct task_struct *next,
2681 struct perf_cpu_context *cpuctx;
2683 unsigned long flags;
2688 local_irq_save(flags);
2692 list_for_each_entry_rcu(pmu, &pmus, entry) {
2693 if (pmu->sched_task) {
2694 cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
2696 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
2698 perf_pmu_disable(pmu);
2700 pmu->sched_task(cpuctx->task_ctx, sched_in);
2702 perf_pmu_enable(pmu);
2704 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
2710 local_irq_restore(flags);
2713 static void perf_event_switch(struct task_struct *task,
2714 struct task_struct *next_prev, bool sched_in);
2716 #define for_each_task_context_nr(ctxn) \
2717 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2720 * Called from scheduler to remove the events of the current task,
2721 * with interrupts disabled.
2723 * We stop each event and update the event value in event->count.
2725 * This does not protect us against NMI, but disable()
2726 * sets the disabled bit in the control field of event _before_
2727 * accessing the event control register. If a NMI hits, then it will
2728 * not restart the event.
2730 void __perf_event_task_sched_out(struct task_struct *task,
2731 struct task_struct *next)
2735 if (__this_cpu_read(perf_sched_cb_usages))
2736 perf_pmu_sched_task(task, next, false);
2738 if (atomic_read(&nr_switch_events))
2739 perf_event_switch(task, next, false);
2741 for_each_task_context_nr(ctxn)
2742 perf_event_context_sched_out(task, ctxn, next);
2745 * if cgroup events exist on this CPU, then we need
2746 * to check if we have to switch out PMU state.
2747 * cgroup event are system-wide mode only
2749 if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
2750 perf_cgroup_sched_out(task, next);
2753 static void task_ctx_sched_out(struct perf_event_context *ctx)
2755 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
2757 if (!cpuctx->task_ctx)
2760 if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
2763 ctx_sched_out(ctx, cpuctx, EVENT_ALL);
2764 cpuctx->task_ctx = NULL;
2768 * Called with IRQs disabled
2770 static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
2771 enum event_type_t event_type)
2773 ctx_sched_out(&cpuctx->ctx, cpuctx, event_type);
2777 ctx_pinned_sched_in(struct perf_event_context *ctx,
2778 struct perf_cpu_context *cpuctx)
2780 struct perf_event *event;
2782 list_for_each_entry(event, &ctx->pinned_groups, group_entry) {
2783 if (event->state <= PERF_EVENT_STATE_OFF)
2785 if (!event_filter_match(event))
2788 /* may need to reset tstamp_enabled */
2789 if (is_cgroup_event(event))
2790 perf_cgroup_mark_enabled(event, ctx);
2792 if (group_can_go_on(event, cpuctx, 1))
2793 group_sched_in(event, cpuctx, ctx);
2796 * If this pinned group hasn't been scheduled,
2797 * put it in error state.
2799 if (event->state == PERF_EVENT_STATE_INACTIVE) {
2800 update_group_times(event);
2801 event->state = PERF_EVENT_STATE_ERROR;
2807 ctx_flexible_sched_in(struct perf_event_context *ctx,
2808 struct perf_cpu_context *cpuctx)
2810 struct perf_event *event;
2813 list_for_each_entry(event, &ctx->flexible_groups, group_entry) {
2814 /* Ignore events in OFF or ERROR state */
2815 if (event->state <= PERF_EVENT_STATE_OFF)
2818 * Listen to the 'cpu' scheduling filter constraint
2821 if (!event_filter_match(event))
2824 /* may need to reset tstamp_enabled */
2825 if (is_cgroup_event(event))
2826 perf_cgroup_mark_enabled(event, ctx);
2828 if (group_can_go_on(event, cpuctx, can_add_hw)) {
2829 if (group_sched_in(event, cpuctx, ctx))
2836 ctx_sched_in(struct perf_event_context *ctx,
2837 struct perf_cpu_context *cpuctx,
2838 enum event_type_t event_type,
2839 struct task_struct *task)
2842 int is_active = ctx->is_active;
2844 ctx->is_active |= event_type;
2845 if (likely(!ctx->nr_events))
2849 ctx->timestamp = now;
2850 perf_cgroup_set_timestamp(task, ctx);
2852 * First go through the list and put on any pinned groups
2853 * in order to give them the best chance of going on.
2855 if (!(is_active & EVENT_PINNED) && (event_type & EVENT_PINNED))
2856 ctx_pinned_sched_in(ctx, cpuctx);
2858 /* Then walk through the lower prio flexible groups */
2859 if (!(is_active & EVENT_FLEXIBLE) && (event_type & EVENT_FLEXIBLE))
2860 ctx_flexible_sched_in(ctx, cpuctx);
2863 static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
2864 enum event_type_t event_type,
2865 struct task_struct *task)
2867 struct perf_event_context *ctx = &cpuctx->ctx;
2869 ctx_sched_in(ctx, cpuctx, event_type, task);
2872 static void perf_event_context_sched_in(struct perf_event_context *ctx,
2873 struct task_struct *task)
2875 struct perf_cpu_context *cpuctx;
2877 cpuctx = __get_cpu_context(ctx);
2878 if (cpuctx->task_ctx == ctx)
2881 perf_ctx_lock(cpuctx, ctx);
2882 perf_pmu_disable(ctx->pmu);
2884 * We want to keep the following priority order:
2885 * cpu pinned (that don't need to move), task pinned,
2886 * cpu flexible, task flexible.
2888 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
2891 cpuctx->task_ctx = ctx;
2893 perf_event_sched_in(cpuctx, cpuctx->task_ctx, task);
2895 perf_pmu_enable(ctx->pmu);
2896 perf_ctx_unlock(cpuctx, ctx);
2900 * Called from scheduler to add the events of the current task
2901 * with interrupts disabled.
2903 * We restore the event value and then enable it.
2905 * This does not protect us against NMI, but enable()
2906 * sets the enabled bit in the control field of event _before_
2907 * accessing the event control register. If a NMI hits, then it will
2908 * keep the event running.
2910 void __perf_event_task_sched_in(struct task_struct *prev,
2911 struct task_struct *task)
2913 struct perf_event_context *ctx;
2916 for_each_task_context_nr(ctxn) {
2917 ctx = task->perf_event_ctxp[ctxn];
2921 perf_event_context_sched_in(ctx, task);
2924 * if cgroup events exist on this CPU, then we need
2925 * to check if we have to switch in PMU state.
2926 * cgroup event are system-wide mode only
2928 if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
2929 perf_cgroup_sched_in(prev, task);
2931 if (atomic_read(&nr_switch_events))
2932 perf_event_switch(task, prev, true);
2934 if (__this_cpu_read(perf_sched_cb_usages))
2935 perf_pmu_sched_task(prev, task, true);
2938 static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
2940 u64 frequency = event->attr.sample_freq;
2941 u64 sec = NSEC_PER_SEC;
2942 u64 divisor, dividend;
2944 int count_fls, nsec_fls, frequency_fls, sec_fls;
2946 count_fls = fls64(count);
2947 nsec_fls = fls64(nsec);
2948 frequency_fls = fls64(frequency);
2952 * We got @count in @nsec, with a target of sample_freq HZ
2953 * the target period becomes:
2956 * period = -------------------
2957 * @nsec * sample_freq
2962 * Reduce accuracy by one bit such that @a and @b converge
2963 * to a similar magnitude.
2965 #define REDUCE_FLS(a, b) \
2967 if (a##_fls > b##_fls) { \
2977 * Reduce accuracy until either term fits in a u64, then proceed with
2978 * the other, so that finally we can do a u64/u64 division.
2980 while (count_fls + sec_fls > 64 && nsec_fls + frequency_fls > 64) {
2981 REDUCE_FLS(nsec, frequency);
2982 REDUCE_FLS(sec, count);
2985 if (count_fls + sec_fls > 64) {
2986 divisor = nsec * frequency;
2988 while (count_fls + sec_fls > 64) {
2989 REDUCE_FLS(count, sec);
2993 dividend = count * sec;
2995 dividend = count * sec;
2997 while (nsec_fls + frequency_fls > 64) {
2998 REDUCE_FLS(nsec, frequency);
3002 divisor = nsec * frequency;
3008 return div64_u64(dividend, divisor);
3011 static DEFINE_PER_CPU(int, perf_throttled_count);
3012 static DEFINE_PER_CPU(u64, perf_throttled_seq);
3014 static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable)
3016 struct hw_perf_event *hwc = &event->hw;
3017 s64 period, sample_period;
3020 period = perf_calculate_period(event, nsec, count);
3022 delta = (s64)(period - hwc->sample_period);
3023 delta = (delta + 7) / 8; /* low pass filter */
3025 sample_period = hwc->sample_period + delta;
3030 hwc->sample_period = sample_period;
3032 if (local64_read(&hwc->period_left) > 8*sample_period) {
3034 event->pmu->stop(event, PERF_EF_UPDATE);
3036 local64_set(&hwc->period_left, 0);
3039 event->pmu->start(event, PERF_EF_RELOAD);
3044 * combine freq adjustment with unthrottling to avoid two passes over the
3045 * events. At the same time, make sure, having freq events does not change
3046 * the rate of unthrottling as that would introduce bias.
3048 static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx,
3051 struct perf_event *event;
3052 struct hw_perf_event *hwc;
3053 u64 now, period = TICK_NSEC;
3057 * only need to iterate over all events iff:
3058 * - context have events in frequency mode (needs freq adjust)
3059 * - there are events to unthrottle on this cpu
3061 if (!(ctx->nr_freq || needs_unthr))
3064 raw_spin_lock(&ctx->lock);
3065 perf_pmu_disable(ctx->pmu);
3067 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
3068 if (event->state != PERF_EVENT_STATE_ACTIVE)
3071 if (!event_filter_match(event))
3074 perf_pmu_disable(event->pmu);
3078 if (hwc->interrupts == MAX_INTERRUPTS) {
3079 hwc->interrupts = 0;
3080 perf_log_throttle(event, 1);
3081 event->pmu->start(event, 0);
3084 if (!event->attr.freq || !event->attr.sample_freq)
3088 * stop the event and update event->count
3090 event->pmu->stop(event, PERF_EF_UPDATE);
3092 now = local64_read(&event->count);
3093 delta = now - hwc->freq_count_stamp;
3094 hwc->freq_count_stamp = now;
3098 * reload only if value has changed
3099 * we have stopped the event so tell that
3100 * to perf_adjust_period() to avoid stopping it
3104 perf_adjust_period(event, period, delta, false);
3106 event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
3108 perf_pmu_enable(event->pmu);
3111 perf_pmu_enable(ctx->pmu);
3112 raw_spin_unlock(&ctx->lock);
3116 * Round-robin a context's events:
3118 static void rotate_ctx(struct perf_event_context *ctx)
3121 * Rotate the first entry last of non-pinned groups. Rotation might be
3122 * disabled by the inheritance code.
3124 if (!ctx->rotate_disable)
3125 list_rotate_left(&ctx->flexible_groups);
3128 static int perf_rotate_context(struct perf_cpu_context *cpuctx)
3130 struct perf_event_context *ctx = NULL;
3133 if (cpuctx->ctx.nr_events) {
3134 if (cpuctx->ctx.nr_events != cpuctx->ctx.nr_active)
3138 ctx = cpuctx->task_ctx;
3139 if (ctx && ctx->nr_events) {
3140 if (ctx->nr_events != ctx->nr_active)
3147 perf_ctx_lock(cpuctx, cpuctx->task_ctx);
3148 perf_pmu_disable(cpuctx->ctx.pmu);
3150 cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
3152 ctx_sched_out(ctx, cpuctx, EVENT_FLEXIBLE);
3154 rotate_ctx(&cpuctx->ctx);
3158 perf_event_sched_in(cpuctx, ctx, current);
3160 perf_pmu_enable(cpuctx->ctx.pmu);
3161 perf_ctx_unlock(cpuctx, cpuctx->task_ctx);
3167 #ifdef CONFIG_NO_HZ_FULL
3168 bool perf_event_can_stop_tick(void)
3170 if (atomic_read(&nr_freq_events) ||
3171 __this_cpu_read(perf_throttled_count))
3178 void perf_event_task_tick(void)
3180 struct list_head *head = this_cpu_ptr(&active_ctx_list);
3181 struct perf_event_context *ctx, *tmp;
3184 WARN_ON(!irqs_disabled());
3186 __this_cpu_inc(perf_throttled_seq);
3187 throttled = __this_cpu_xchg(perf_throttled_count, 0);
3189 list_for_each_entry_safe(ctx, tmp, head, active_ctx_list)
3190 perf_adjust_freq_unthr_context(ctx, throttled);
3193 static int event_enable_on_exec(struct perf_event *event,
3194 struct perf_event_context *ctx)
3196 if (!event->attr.enable_on_exec)
3199 event->attr.enable_on_exec = 0;
3200 if (event->state >= PERF_EVENT_STATE_INACTIVE)
3203 __perf_event_mark_enabled(event);
3209 * Enable all of a task's events that have been marked enable-on-exec.
3210 * This expects task == current.
3212 static void perf_event_enable_on_exec(int ctxn)
3214 struct perf_event_context *ctx, *clone_ctx = NULL;
3215 struct perf_event *event;
3216 unsigned long flags;
3220 local_irq_save(flags);
3221 ctx = current->perf_event_ctxp[ctxn];
3222 if (!ctx || !ctx->nr_events)
3226 * We must ctxsw out cgroup events to avoid conflict
3227 * when invoking perf_task_event_sched_in() later on
3228 * in this function. Otherwise we end up trying to
3229 * ctxswin cgroup events which are already scheduled
3232 perf_cgroup_sched_out(current, NULL);
3234 raw_spin_lock(&ctx->lock);
3235 task_ctx_sched_out(ctx);
3237 list_for_each_entry(event, &ctx->event_list, event_entry) {
3238 ret = event_enable_on_exec(event, ctx);
3244 * Unclone this context if we enabled any event.
3247 clone_ctx = unclone_ctx(ctx);
3249 raw_spin_unlock(&ctx->lock);
3252 * Also calls ctxswin for cgroup events, if any:
3254 perf_event_context_sched_in(ctx, ctx->task);
3256 local_irq_restore(flags);
3262 void perf_event_exec(void)
3267 for_each_task_context_nr(ctxn)
3268 perf_event_enable_on_exec(ctxn);
3272 struct perf_read_data {
3273 struct perf_event *event;
3279 * Cross CPU call to read the hardware event
3281 static void __perf_event_read(void *info)
3283 struct perf_read_data *data = info;
3284 struct perf_event *sub, *event = data->event;
3285 struct perf_event_context *ctx = event->ctx;
3286 struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
3287 struct pmu *pmu = event->pmu;
3290 * If this is a task context, we need to check whether it is
3291 * the current task context of this cpu. If not it has been
3292 * scheduled out before the smp call arrived. In that case
3293 * event->count would have been updated to a recent sample
3294 * when the event was scheduled out.
3296 if (ctx->task && cpuctx->task_ctx != ctx)
3299 raw_spin_lock(&ctx->lock);
3300 if (ctx->is_active) {
3301 update_context_time(ctx);
3302 update_cgrp_time_from_event(event);
3305 update_event_times(event);
3306 if (event->state != PERF_EVENT_STATE_ACTIVE)
3315 pmu->start_txn(pmu, PERF_PMU_TXN_READ);
3319 list_for_each_entry(sub, &event->sibling_list, group_entry) {
3320 update_event_times(sub);
3321 if (sub->state == PERF_EVENT_STATE_ACTIVE) {
3323 * Use sibling's PMU rather than @event's since
3324 * sibling could be on different (eg: software) PMU.
3326 sub->pmu->read(sub);
3330 data->ret = pmu->commit_txn(pmu);
3333 raw_spin_unlock(&ctx->lock);
3336 static inline u64 perf_event_count(struct perf_event *event)
3338 if (event->pmu->count)
3339 return event->pmu->count(event);
3341 return __perf_event_count(event);
3345 * NMI-safe method to read a local event, that is an event that
3347 * - either for the current task, or for this CPU
3348 * - does not have inherit set, for inherited task events
3349 * will not be local and we cannot read them atomically
3350 * - must not have a pmu::count method
3352 u64 perf_event_read_local(struct perf_event *event)
3354 unsigned long flags;
3358 * Disabling interrupts avoids all counter scheduling (context
3359 * switches, timer based rotation and IPIs).
3361 local_irq_save(flags);
3363 /* If this is a per-task event, it must be for current */
3364 WARN_ON_ONCE((event->attach_state & PERF_ATTACH_TASK) &&
3365 event->hw.target != current);
3367 /* If this is a per-CPU event, it must be for this CPU */
3368 WARN_ON_ONCE(!(event->attach_state & PERF_ATTACH_TASK) &&
3369 event->cpu != smp_processor_id());
3372 * It must not be an event with inherit set, we cannot read
3373 * all child counters from atomic context.
3375 WARN_ON_ONCE(event->attr.inherit);
3378 * It must not have a pmu::count method, those are not
3381 WARN_ON_ONCE(event->pmu->count);
3384 * If the event is currently on this CPU, its either a per-task event,
3385 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3388 if (event->oncpu == smp_processor_id())
3389 event->pmu->read(event);
3391 val = local64_read(&event->count);
3392 local_irq_restore(flags);
3397 static int perf_event_read(struct perf_event *event, bool group)
3402 * If event is enabled and currently active on a CPU, update the
3403 * value in the event structure:
3405 if (event->state == PERF_EVENT_STATE_ACTIVE) {
3406 struct perf_read_data data = {
3411 smp_call_function_single(event->oncpu,
3412 __perf_event_read, &data, 1);
3414 } else if (event->state == PERF_EVENT_STATE_INACTIVE) {
3415 struct perf_event_context *ctx = event->ctx;
3416 unsigned long flags;
3418 raw_spin_lock_irqsave(&ctx->lock, flags);
3420 * may read while context is not active
3421 * (e.g., thread is blocked), in that case
3422 * we cannot update context time
3424 if (ctx->is_active) {
3425 update_context_time(ctx);
3426 update_cgrp_time_from_event(event);
3429 update_group_times(event);
3431 update_event_times(event);
3432 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3439 * Initialize the perf_event context in a task_struct:
3441 static void __perf_event_init_context(struct perf_event_context *ctx)
3443 raw_spin_lock_init(&ctx->lock);
3444 mutex_init(&ctx->mutex);
3445 INIT_LIST_HEAD(&ctx->active_ctx_list);
3446 INIT_LIST_HEAD(&ctx->pinned_groups);
3447 INIT_LIST_HEAD(&ctx->flexible_groups);
3448 INIT_LIST_HEAD(&ctx->event_list);
3449 atomic_set(&ctx->refcount, 1);
3450 INIT_DELAYED_WORK(&ctx->orphans_remove, orphans_remove_work);
3453 static struct perf_event_context *
3454 alloc_perf_context(struct pmu *pmu, struct task_struct *task)
3456 struct perf_event_context *ctx;
3458 ctx = kzalloc(sizeof(struct perf_event_context), GFP_KERNEL);
3462 __perf_event_init_context(ctx);
3465 get_task_struct(task);
3472 static struct task_struct *
3473 find_lively_task_by_vpid(pid_t vpid)
3475 struct task_struct *task;
3481 task = find_task_by_vpid(vpid);
3483 get_task_struct(task);
3487 return ERR_PTR(-ESRCH);
3493 * Returns a matching context with refcount and pincount.
3495 static struct perf_event_context *
3496 find_get_context(struct pmu *pmu, struct task_struct *task,
3497 struct perf_event *event)
3499 struct perf_event_context *ctx, *clone_ctx = NULL;
3500 struct perf_cpu_context *cpuctx;
3501 void *task_ctx_data = NULL;
3502 unsigned long flags;
3504 int cpu = event->cpu;
3507 /* Must be root to operate on a CPU event: */
3508 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
3509 return ERR_PTR(-EACCES);
3512 * We could be clever and allow to attach a event to an
3513 * offline CPU and activate it when the CPU comes up, but
3516 if (!cpu_online(cpu))
3517 return ERR_PTR(-ENODEV);
3519 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
3528 ctxn = pmu->task_ctx_nr;
3532 if (event->attach_state & PERF_ATTACH_TASK_DATA) {
3533 task_ctx_data = kzalloc(pmu->task_ctx_size, GFP_KERNEL);
3534 if (!task_ctx_data) {
3541 ctx = perf_lock_task_context(task, ctxn, &flags);
3543 clone_ctx = unclone_ctx(ctx);
3546 if (task_ctx_data && !ctx->task_ctx_data) {
3547 ctx->task_ctx_data = task_ctx_data;
3548 task_ctx_data = NULL;
3550 raw_spin_unlock_irqrestore(&ctx->lock, flags);
3555 ctx = alloc_perf_context(pmu, task);
3560 if (task_ctx_data) {
3561 ctx->task_ctx_data = task_ctx_data;
3562 task_ctx_data = NULL;
3566 mutex_lock(&task->perf_event_mutex);
3568 * If it has already passed perf_event_exit_task().
3569 * we must see PF_EXITING, it takes this mutex too.
3571 if (task->flags & PF_EXITING)
3573 else if (task->perf_event_ctxp[ctxn])
3578 rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
3580 mutex_unlock(&task->perf_event_mutex);
3582 if (unlikely(err)) {
3591 kfree(task_ctx_data);
3595 kfree(task_ctx_data);
3596 return ERR_PTR(err);
3599 static void perf_event_free_filter(struct perf_event *event);
3600 static void perf_event_free_bpf_prog(struct perf_event *event);
3602 static void free_event_rcu(struct rcu_head *head)
3604 struct perf_event *event;
3606 event = container_of(head, struct perf_event, rcu_head);
3608 put_pid_ns(event->ns);
3609 perf_event_free_filter(event);
3613 static void ring_buffer_attach(struct perf_event *event,
3614 struct ring_buffer *rb);
3616 static void unaccount_event_cpu(struct perf_event *event, int cpu)
3621 if (is_cgroup_event(event))
3622 atomic_dec(&per_cpu(perf_cgroup_events, cpu));
3625 static void unaccount_event(struct perf_event *event)
3630 if (event->attach_state & PERF_ATTACH_TASK)
3631 static_key_slow_dec_deferred(&perf_sched_events);
3632 if (event->attr.mmap || event->attr.mmap_data)
3633 atomic_dec(&nr_mmap_events);
3634 if (event->attr.comm)
3635 atomic_dec(&nr_comm_events);
3636 if (event->attr.task)
3637 atomic_dec(&nr_task_events);
3638 if (event->attr.freq)
3639 atomic_dec(&nr_freq_events);
3640 if (event->attr.context_switch) {
3641 static_key_slow_dec_deferred(&perf_sched_events);
3642 atomic_dec(&nr_switch_events);
3644 if (is_cgroup_event(event))
3645 static_key_slow_dec_deferred(&perf_sched_events);
3646 if (has_branch_stack(event))
3647 static_key_slow_dec_deferred(&perf_sched_events);
3649 unaccount_event_cpu(event, event->cpu);
3653 * The following implement mutual exclusion of events on "exclusive" pmus
3654 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3655 * at a time, so we disallow creating events that might conflict, namely:
3657 * 1) cpu-wide events in the presence of per-task events,
3658 * 2) per-task events in the presence of cpu-wide events,
3659 * 3) two matching events on the same context.
3661 * The former two cases are handled in the allocation path (perf_event_alloc(),
3662 * __free_event()), the latter -- before the first perf_install_in_context().
3664 static int exclusive_event_init(struct perf_event *event)
3666 struct pmu *pmu = event->pmu;
3668 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3672 * Prevent co-existence of per-task and cpu-wide events on the
3673 * same exclusive pmu.
3675 * Negative pmu::exclusive_cnt means there are cpu-wide
3676 * events on this "exclusive" pmu, positive means there are
3679 * Since this is called in perf_event_alloc() path, event::ctx
3680 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3681 * to mean "per-task event", because unlike other attach states it
3682 * never gets cleared.
3684 if (event->attach_state & PERF_ATTACH_TASK) {
3685 if (!atomic_inc_unless_negative(&pmu->exclusive_cnt))
3688 if (!atomic_dec_unless_positive(&pmu->exclusive_cnt))
3695 static void exclusive_event_destroy(struct perf_event *event)
3697 struct pmu *pmu = event->pmu;
3699 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3702 /* see comment in exclusive_event_init() */
3703 if (event->attach_state & PERF_ATTACH_TASK)
3704 atomic_dec(&pmu->exclusive_cnt);
3706 atomic_inc(&pmu->exclusive_cnt);
3709 static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2)
3711 if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) &&
3712 (e1->cpu == e2->cpu ||
3719 /* Called under the same ctx::mutex as perf_install_in_context() */
3720 static bool exclusive_event_installable(struct perf_event *event,
3721 struct perf_event_context *ctx)
3723 struct perf_event *iter_event;
3724 struct pmu *pmu = event->pmu;
3726 if (!(pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE))
3729 list_for_each_entry(iter_event, &ctx->event_list, event_entry) {
3730 if (exclusive_event_match(iter_event, event))
3737 static void __free_event(struct perf_event *event)
3739 if (!event->parent) {
3740 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
3741 put_callchain_buffers();
3744 perf_event_free_bpf_prog(event);
3747 event->destroy(event);
3749 if (event->pmu->free_drv_configs)
3750 event->pmu->free_drv_configs(event);
3753 put_ctx(event->ctx);
3756 exclusive_event_destroy(event);
3757 module_put(event->pmu->module);
3760 call_rcu(&event->rcu_head, free_event_rcu);
3763 static void _free_event(struct perf_event *event)
3765 irq_work_sync(&event->pending);
3767 unaccount_event(event);
3771 * Can happen when we close an event with re-directed output.
3773 * Since we have a 0 refcount, perf_mmap_close() will skip
3774 * over us; possibly making our ring_buffer_put() the last.
3776 mutex_lock(&event->mmap_mutex);
3777 ring_buffer_attach(event, NULL);
3778 mutex_unlock(&event->mmap_mutex);
3781 if (is_cgroup_event(event))
3782 perf_detach_cgroup(event);
3784 __free_event(event);
3788 * Used to free events which have a known refcount of 1, such as in error paths
3789 * where the event isn't exposed yet and inherited events.
3791 static void free_event(struct perf_event *event)
3793 if (WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1,
3794 "unexpected event refcount: %ld; ptr=%p\n",
3795 atomic_long_read(&event->refcount), event)) {
3796 /* leak to avoid use-after-free */
3804 * Remove user event from the owner task.
3806 static void perf_remove_from_owner(struct perf_event *event)
3808 struct task_struct *owner;
3811 owner = ACCESS_ONCE(event->owner);
3813 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3814 * !owner it means the list deletion is complete and we can indeed
3815 * free this event, otherwise we need to serialize on
3816 * owner->perf_event_mutex.
3818 smp_read_barrier_depends();
3821 * Since delayed_put_task_struct() also drops the last
3822 * task reference we can safely take a new reference
3823 * while holding the rcu_read_lock().
3825 get_task_struct(owner);
3831 * If we're here through perf_event_exit_task() we're already
3832 * holding ctx->mutex which would be an inversion wrt. the
3833 * normal lock order.
3835 * However we can safely take this lock because its the child
3838 mutex_lock_nested(&owner->perf_event_mutex, SINGLE_DEPTH_NESTING);
3841 * We have to re-check the event->owner field, if it is cleared
3842 * we raced with perf_event_exit_task(), acquiring the mutex
3843 * ensured they're done, and we can proceed with freeing the
3847 list_del_init(&event->owner_entry);
3848 mutex_unlock(&owner->perf_event_mutex);
3849 put_task_struct(owner);
3853 static void put_event(struct perf_event *event)
3855 struct perf_event_context *ctx;
3857 if (!atomic_long_dec_and_test(&event->refcount))
3860 if (!is_kernel_event(event))
3861 perf_remove_from_owner(event);
3864 * There are two ways this annotation is useful:
3866 * 1) there is a lock recursion from perf_event_exit_task
3867 * see the comment there.
3869 * 2) there is a lock-inversion with mmap_sem through
3870 * perf_read_group(), which takes faults while
3871 * holding ctx->mutex, however this is called after
3872 * the last filedesc died, so there is no possibility
3873 * to trigger the AB-BA case.
3875 ctx = perf_event_ctx_lock_nested(event, SINGLE_DEPTH_NESTING);
3876 WARN_ON_ONCE(ctx->parent_ctx);
3877 perf_remove_from_context(event, true);
3878 perf_event_ctx_unlock(event, ctx);
3883 int perf_event_release_kernel(struct perf_event *event)
3888 EXPORT_SYMBOL_GPL(perf_event_release_kernel);
3891 * Called when the last reference to the file is gone.
3893 static int perf_release(struct inode *inode, struct file *file)
3895 put_event(file->private_data);
3900 * Remove all orphanes events from the context.
3902 static void orphans_remove_work(struct work_struct *work)
3904 struct perf_event_context *ctx;
3905 struct perf_event *event, *tmp;
3907 ctx = container_of(work, struct perf_event_context,
3908 orphans_remove.work);
3910 mutex_lock(&ctx->mutex);
3911 list_for_each_entry_safe(event, tmp, &ctx->event_list, event_entry) {
3912 struct perf_event *parent_event = event->parent;
3914 if (!is_orphaned_child(event))
3917 perf_remove_from_context(event, true);
3919 mutex_lock(&parent_event->child_mutex);
3920 list_del_init(&event->child_list);
3921 mutex_unlock(&parent_event->child_mutex);
3924 put_event(parent_event);
3927 raw_spin_lock_irq(&ctx->lock);
3928 ctx->orphans_remove_sched = false;
3929 raw_spin_unlock_irq(&ctx->lock);
3930 mutex_unlock(&ctx->mutex);
3935 u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
3937 struct perf_event *child;
3943 mutex_lock(&event->child_mutex);
3945 (void)perf_event_read(event, false);
3946 total += perf_event_count(event);
3948 *enabled += event->total_time_enabled +
3949 atomic64_read(&event->child_total_time_enabled);
3950 *running += event->total_time_running +
3951 atomic64_read(&event->child_total_time_running);
3953 list_for_each_entry(child, &event->child_list, child_list) {
3954 (void)perf_event_read(child, false);
3955 total += perf_event_count(child);
3956 *enabled += child->total_time_enabled;
3957 *running += child->total_time_running;
3959 mutex_unlock(&event->child_mutex);
3963 EXPORT_SYMBOL_GPL(perf_event_read_value);
3965 static int __perf_read_group_add(struct perf_event *leader,
3966 u64 read_format, u64 *values)
3968 struct perf_event *sub;
3969 int n = 1; /* skip @nr */
3972 ret = perf_event_read(leader, true);
3977 * Since we co-schedule groups, {enabled,running} times of siblings
3978 * will be identical to those of the leader, so we only publish one
3981 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
3982 values[n++] += leader->total_time_enabled +
3983 atomic64_read(&leader->child_total_time_enabled);
3986 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
3987 values[n++] += leader->total_time_running +
3988 atomic64_read(&leader->child_total_time_running);
3992 * Write {count,id} tuples for every sibling.
3994 values[n++] += perf_event_count(leader);
3995 if (read_format & PERF_FORMAT_ID)
3996 values[n++] = primary_event_id(leader);
3998 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
3999 values[n++] += perf_event_count(sub);
4000 if (read_format & PERF_FORMAT_ID)
4001 values[n++] = primary_event_id(sub);
4007 static int perf_read_group(struct perf_event *event,
4008 u64 read_format, char __user *buf)
4010 struct perf_event *leader = event->group_leader, *child;
4011 struct perf_event_context *ctx = leader->ctx;
4015 lockdep_assert_held(&ctx->mutex);
4017 values = kzalloc(event->read_size, GFP_KERNEL);
4021 values[0] = 1 + leader->nr_siblings;
4024 * By locking the child_mutex of the leader we effectively
4025 * lock the child list of all siblings.. XXX explain how.
4027 mutex_lock(&leader->child_mutex);
4029 ret = __perf_read_group_add(leader, read_format, values);
4033 list_for_each_entry(child, &leader->child_list, child_list) {
4034 ret = __perf_read_group_add(child, read_format, values);
4039 mutex_unlock(&leader->child_mutex);
4041 ret = event->read_size;
4042 if (copy_to_user(buf, values, event->read_size))
4047 mutex_unlock(&leader->child_mutex);
4053 static int perf_read_one(struct perf_event *event,
4054 u64 read_format, char __user *buf)
4056 u64 enabled, running;
4060 values[n++] = perf_event_read_value(event, &enabled, &running);
4061 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
4062 values[n++] = enabled;
4063 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
4064 values[n++] = running;
4065 if (read_format & PERF_FORMAT_ID)
4066 values[n++] = primary_event_id(event);
4068 if (copy_to_user(buf, values, n * sizeof(u64)))
4071 return n * sizeof(u64);
4074 static bool is_event_hup(struct perf_event *event)
4078 if (event->state != PERF_EVENT_STATE_EXIT)
4081 mutex_lock(&event->child_mutex);
4082 no_children = list_empty(&event->child_list);
4083 mutex_unlock(&event->child_mutex);
4088 * Read the performance event - simple non blocking version for now
4091 __perf_read(struct perf_event *event, char __user *buf, size_t count)
4093 u64 read_format = event->attr.read_format;
4097 * Return end-of-file for a read on a event that is in
4098 * error state (i.e. because it was pinned but it couldn't be
4099 * scheduled on to the CPU at some point).
4101 if (event->state == PERF_EVENT_STATE_ERROR)
4104 if (count < event->read_size)
4107 WARN_ON_ONCE(event->ctx->parent_ctx);
4108 if (read_format & PERF_FORMAT_GROUP)
4109 ret = perf_read_group(event, read_format, buf);
4111 ret = perf_read_one(event, read_format, buf);
4117 perf_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
4119 struct perf_event *event = file->private_data;
4120 struct perf_event_context *ctx;
4123 ctx = perf_event_ctx_lock(event);
4124 ret = __perf_read(event, buf, count);
4125 perf_event_ctx_unlock(event, ctx);
4130 static unsigned int perf_poll(struct file *file, poll_table *wait)
4132 struct perf_event *event = file->private_data;
4133 struct ring_buffer *rb;
4134 unsigned int events = POLLHUP;
4136 poll_wait(file, &event->waitq, wait);
4138 if (is_event_hup(event))
4142 * Pin the event->rb by taking event->mmap_mutex; otherwise
4143 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4145 mutex_lock(&event->mmap_mutex);
4148 events = atomic_xchg(&rb->poll, 0);
4149 mutex_unlock(&event->mmap_mutex);
4153 static void _perf_event_reset(struct perf_event *event)
4155 (void)perf_event_read(event, false);
4156 local64_set(&event->count, 0);
4157 perf_event_update_userpage(event);
4161 * Holding the top-level event's child_mutex means that any
4162 * descendant process that has inherited this event will block
4163 * in sync_child_event if it goes to exit, thus satisfying the
4164 * task existence requirements of perf_event_enable/disable.
4166 static void perf_event_for_each_child(struct perf_event *event,
4167 void (*func)(struct perf_event *))
4169 struct perf_event *child;
4171 WARN_ON_ONCE(event->ctx->parent_ctx);
4173 mutex_lock(&event->child_mutex);
4175 list_for_each_entry(child, &event->child_list, child_list)
4177 mutex_unlock(&event->child_mutex);
4180 static void perf_event_for_each(struct perf_event *event,
4181 void (*func)(struct perf_event *))
4183 struct perf_event_context *ctx = event->ctx;
4184 struct perf_event *sibling;
4186 lockdep_assert_held(&ctx->mutex);
4188 event = event->group_leader;
4190 perf_event_for_each_child(event, func);
4191 list_for_each_entry(sibling, &event->sibling_list, group_entry)
4192 perf_event_for_each_child(sibling, func);
4195 struct period_event {
4196 struct perf_event *event;
4200 static int __perf_event_period(void *info)
4202 struct period_event *pe = info;
4203 struct perf_event *event = pe->event;
4204 struct perf_event_context *ctx = event->ctx;
4205 u64 value = pe->value;
4208 raw_spin_lock(&ctx->lock);
4209 if (event->attr.freq) {
4210 event->attr.sample_freq = value;
4212 event->attr.sample_period = value;
4213 event->hw.sample_period = value;
4216 active = (event->state == PERF_EVENT_STATE_ACTIVE);
4218 perf_pmu_disable(ctx->pmu);
4219 event->pmu->stop(event, PERF_EF_UPDATE);
4222 local64_set(&event->hw.period_left, 0);
4225 event->pmu->start(event, PERF_EF_RELOAD);
4226 perf_pmu_enable(ctx->pmu);
4228 raw_spin_unlock(&ctx->lock);
4233 static int perf_event_period(struct perf_event *event, u64 __user *arg)
4235 struct period_event pe = { .event = event, };
4236 struct perf_event_context *ctx = event->ctx;
4237 struct task_struct *task;
4240 if (!is_sampling_event(event))
4243 if (copy_from_user(&value, arg, sizeof(value)))
4249 if (event->attr.freq && value > sysctl_perf_event_sample_rate)
4256 cpu_function_call(event->cpu, __perf_event_period, &pe);
4261 if (!task_function_call(task, __perf_event_period, &pe))
4264 raw_spin_lock_irq(&ctx->lock);
4265 if (ctx->is_active) {
4266 raw_spin_unlock_irq(&ctx->lock);
4271 if (event->attr.freq) {
4272 event->attr.sample_freq = value;
4274 event->attr.sample_period = value;
4275 event->hw.sample_period = value;
4278 local64_set(&event->hw.period_left, 0);
4279 raw_spin_unlock_irq(&ctx->lock);
4284 static const struct file_operations perf_fops;
4286 static inline int perf_fget_light(int fd, struct fd *p)
4288 struct fd f = fdget(fd);
4292 if (f.file->f_op != &perf_fops) {
4300 static int perf_event_set_output(struct perf_event *event,
4301 struct perf_event *output_event);
4302 static int perf_event_set_filter(struct perf_event *event, void __user *arg);
4303 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd);
4304 static int perf_event_drv_configs(struct perf_event *event,
4307 static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg)
4309 void (*func)(struct perf_event *);
4313 case PERF_EVENT_IOC_ENABLE:
4314 func = _perf_event_enable;
4316 case PERF_EVENT_IOC_DISABLE:
4317 func = _perf_event_disable;
4319 case PERF_EVENT_IOC_RESET:
4320 func = _perf_event_reset;
4323 case PERF_EVENT_IOC_REFRESH:
4324 return _perf_event_refresh(event, arg);
4326 case PERF_EVENT_IOC_PERIOD:
4327 return perf_event_period(event, (u64 __user *)arg);
4329 case PERF_EVENT_IOC_ID:
4331 u64 id = primary_event_id(event);
4333 if (copy_to_user((void __user *)arg, &id, sizeof(id)))
4338 case PERF_EVENT_IOC_SET_OUTPUT:
4342 struct perf_event *output_event;
4344 ret = perf_fget_light(arg, &output);
4347 output_event = output.file->private_data;
4348 ret = perf_event_set_output(event, output_event);
4351 ret = perf_event_set_output(event, NULL);
4356 case PERF_EVENT_IOC_SET_FILTER:
4357 return perf_event_set_filter(event, (void __user *)arg);
4359 case PERF_EVENT_IOC_SET_BPF:
4360 return perf_event_set_bpf_prog(event, arg);
4362 case PERF_EVENT_IOC_SET_DRV_CONFIGS:
4363 return perf_event_drv_configs(event, (void __user *)arg);
4369 if (flags & PERF_IOC_FLAG_GROUP)
4370 perf_event_for_each(event, func);
4372 perf_event_for_each_child(event, func);
4377 static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
4379 struct perf_event *event = file->private_data;
4380 struct perf_event_context *ctx;
4383 ctx = perf_event_ctx_lock(event);
4384 ret = _perf_ioctl(event, cmd, arg);
4385 perf_event_ctx_unlock(event, ctx);
4390 #ifdef CONFIG_COMPAT
4391 static long perf_compat_ioctl(struct file *file, unsigned int cmd,
4394 switch (_IOC_NR(cmd)) {
4395 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER):
4396 case _IOC_NR(PERF_EVENT_IOC_ID):
4397 case _IOC_NR(PERF_EVENT_IOC_SET_DRV_CONFIGS):
4398 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4399 if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
4400 cmd &= ~IOCSIZE_MASK;
4401 cmd |= sizeof(void *) << IOCSIZE_SHIFT;
4405 return perf_ioctl(file, cmd, arg);
4408 # define perf_compat_ioctl NULL
4411 int perf_event_task_enable(void)
4413 struct perf_event_context *ctx;
4414 struct perf_event *event;
4416 mutex_lock(¤t->perf_event_mutex);
4417 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
4418 ctx = perf_event_ctx_lock(event);
4419 perf_event_for_each_child(event, _perf_event_enable);
4420 perf_event_ctx_unlock(event, ctx);
4422 mutex_unlock(¤t->perf_event_mutex);
4427 int perf_event_task_disable(void)
4429 struct perf_event_context *ctx;
4430 struct perf_event *event;
4432 mutex_lock(¤t->perf_event_mutex);
4433 list_for_each_entry(event, ¤t->perf_event_list, owner_entry) {
4434 ctx = perf_event_ctx_lock(event);
4435 perf_event_for_each_child(event, _perf_event_disable);
4436 perf_event_ctx_unlock(event, ctx);
4438 mutex_unlock(¤t->perf_event_mutex);
4443 static int perf_event_index(struct perf_event *event)
4445 if (event->hw.state & PERF_HES_STOPPED)
4448 if (event->state != PERF_EVENT_STATE_ACTIVE)
4451 return event->pmu->event_idx(event);
4454 static void calc_timer_values(struct perf_event *event,
4461 *now = perf_clock();
4462 ctx_time = event->shadow_ctx_time + *now;
4463 *enabled = ctx_time - event->tstamp_enabled;
4464 *running = ctx_time - event->tstamp_running;
4467 static void perf_event_init_userpage(struct perf_event *event)
4469 struct perf_event_mmap_page *userpg;
4470 struct ring_buffer *rb;
4473 rb = rcu_dereference(event->rb);
4477 userpg = rb->user_page;
4479 /* Allow new userspace to detect that bit 0 is deprecated */
4480 userpg->cap_bit0_is_deprecated = 1;
4481 userpg->size = offsetof(struct perf_event_mmap_page, __reserved);
4482 userpg->data_offset = PAGE_SIZE;
4483 userpg->data_size = perf_data_size(rb);
4489 void __weak arch_perf_update_userpage(
4490 struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now)
4495 * Callers need to ensure there can be no nesting of this function, otherwise
4496 * the seqlock logic goes bad. We can not serialize this because the arch
4497 * code calls this from NMI context.
4499 void perf_event_update_userpage(struct perf_event *event)
4501 struct perf_event_mmap_page *userpg;
4502 struct ring_buffer *rb;
4503 u64 enabled, running, now;
4506 rb = rcu_dereference(event->rb);
4511 * compute total_time_enabled, total_time_running
4512 * based on snapshot values taken when the event
4513 * was last scheduled in.
4515 * we cannot simply called update_context_time()
4516 * because of locking issue as we can be called in
4519 calc_timer_values(event, &now, &enabled, &running);
4521 userpg = rb->user_page;
4523 * Disable preemption so as to not let the corresponding user-space
4524 * spin too long if we get preempted.
4529 userpg->index = perf_event_index(event);
4530 userpg->offset = perf_event_count(event);
4532 userpg->offset -= local64_read(&event->hw.prev_count);
4534 userpg->time_enabled = enabled +
4535 atomic64_read(&event->child_total_time_enabled);
4537 userpg->time_running = running +
4538 atomic64_read(&event->child_total_time_running);
4540 arch_perf_update_userpage(event, userpg, now);
4549 static int perf_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
4551 struct perf_event *event = vma->vm_file->private_data;
4552 struct ring_buffer *rb;
4553 int ret = VM_FAULT_SIGBUS;
4555 if (vmf->flags & FAULT_FLAG_MKWRITE) {
4556 if (vmf->pgoff == 0)
4562 rb = rcu_dereference(event->rb);
4566 if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
4569 vmf->page = perf_mmap_to_page(rb, vmf->pgoff);
4573 get_page(vmf->page);
4574 vmf->page->mapping = vma->vm_file->f_mapping;
4575 vmf->page->index = vmf->pgoff;
4584 static void ring_buffer_attach(struct perf_event *event,
4585 struct ring_buffer *rb)
4587 struct ring_buffer *old_rb = NULL;
4588 unsigned long flags;
4592 * Should be impossible, we set this when removing
4593 * event->rb_entry and wait/clear when adding event->rb_entry.
4595 WARN_ON_ONCE(event->rcu_pending);
4598 spin_lock_irqsave(&old_rb->event_lock, flags);
4599 list_del_rcu(&event->rb_entry);
4600 spin_unlock_irqrestore(&old_rb->event_lock, flags);
4602 event->rcu_batches = get_state_synchronize_rcu();
4603 event->rcu_pending = 1;
4607 if (event->rcu_pending) {
4608 cond_synchronize_rcu(event->rcu_batches);
4609 event->rcu_pending = 0;
4612 spin_lock_irqsave(&rb->event_lock, flags);
4613 list_add_rcu(&event->rb_entry, &rb->event_list);
4614 spin_unlock_irqrestore(&rb->event_lock, flags);
4617 rcu_assign_pointer(event->rb, rb);
4620 ring_buffer_put(old_rb);
4622 * Since we detached before setting the new rb, so that we
4623 * could attach the new rb, we could have missed a wakeup.
4626 wake_up_all(&event->waitq);
4630 static void ring_buffer_wakeup(struct perf_event *event)
4632 struct ring_buffer *rb;
4635 rb = rcu_dereference(event->rb);
4637 list_for_each_entry_rcu(event, &rb->event_list, rb_entry)
4638 wake_up_all(&event->waitq);
4643 struct ring_buffer *ring_buffer_get(struct perf_event *event)
4645 struct ring_buffer *rb;
4648 rb = rcu_dereference(event->rb);
4650 if (!atomic_inc_not_zero(&rb->refcount))
4658 void ring_buffer_put(struct ring_buffer *rb)
4660 if (!atomic_dec_and_test(&rb->refcount))
4663 WARN_ON_ONCE(!list_empty(&rb->event_list));
4665 call_rcu(&rb->rcu_head, rb_free_rcu);
4668 static void perf_mmap_open(struct vm_area_struct *vma)
4670 struct perf_event *event = vma->vm_file->private_data;
4672 atomic_inc(&event->mmap_count);
4673 atomic_inc(&event->rb->mmap_count);
4676 atomic_inc(&event->rb->aux_mmap_count);
4678 if (event->pmu->event_mapped)
4679 event->pmu->event_mapped(event);
4682 static void perf_pmu_output_stop(struct perf_event *event);
4685 * A buffer can be mmap()ed multiple times; either directly through the same
4686 * event, or through other events by use of perf_event_set_output().
4688 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4689 * the buffer here, where we still have a VM context. This means we need
4690 * to detach all events redirecting to us.
4692 static void perf_mmap_close(struct vm_area_struct *vma)
4694 struct perf_event *event = vma->vm_file->private_data;
4696 struct ring_buffer *rb = ring_buffer_get(event);
4697 struct user_struct *mmap_user = rb->mmap_user;
4698 int mmap_locked = rb->mmap_locked;
4699 unsigned long size = perf_data_size(rb);
4701 if (event->pmu->event_unmapped)
4702 event->pmu->event_unmapped(event);
4705 * rb->aux_mmap_count will always drop before rb->mmap_count and
4706 * event->mmap_count, so it is ok to use event->mmap_mutex to
4707 * serialize with perf_mmap here.
4709 if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff &&
4710 atomic_dec_and_mutex_lock(&rb->aux_mmap_count, &event->mmap_mutex)) {
4712 * Stop all AUX events that are writing to this buffer,
4713 * so that we can free its AUX pages and corresponding PMU
4714 * data. Note that after rb::aux_mmap_count dropped to zero,
4715 * they won't start any more (see perf_aux_output_begin()).
4717 perf_pmu_output_stop(event);
4719 /* now it's safe to free the pages */
4720 atomic_long_sub(rb->aux_nr_pages, &mmap_user->locked_vm);
4721 vma->vm_mm->pinned_vm -= rb->aux_mmap_locked;
4723 /* this has to be the last one */
4725 WARN_ON_ONCE(atomic_read(&rb->aux_refcount));
4727 mutex_unlock(&event->mmap_mutex);
4730 atomic_dec(&rb->mmap_count);
4732 if (!atomic_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
4735 ring_buffer_attach(event, NULL);
4736 mutex_unlock(&event->mmap_mutex);
4738 /* If there's still other mmap()s of this buffer, we're done. */
4739 if (atomic_read(&rb->mmap_count))
4743 * No other mmap()s, detach from all other events that might redirect
4744 * into the now unreachable buffer. Somewhat complicated by the
4745 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4749 list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
4750 if (!atomic_long_inc_not_zero(&event->refcount)) {
4752 * This event is en-route to free_event() which will
4753 * detach it and remove it from the list.
4759 mutex_lock(&event->mmap_mutex);
4761 * Check we didn't race with perf_event_set_output() which can
4762 * swizzle the rb from under us while we were waiting to
4763 * acquire mmap_mutex.
4765 * If we find a different rb; ignore this event, a next
4766 * iteration will no longer find it on the list. We have to
4767 * still restart the iteration to make sure we're not now
4768 * iterating the wrong list.
4770 if (event->rb == rb)
4771 ring_buffer_attach(event, NULL);
4773 mutex_unlock(&event->mmap_mutex);
4777 * Restart the iteration; either we're on the wrong list or
4778 * destroyed its integrity by doing a deletion.
4785 * It could be there's still a few 0-ref events on the list; they'll
4786 * get cleaned up by free_event() -- they'll also still have their
4787 * ref on the rb and will free it whenever they are done with it.
4789 * Aside from that, this buffer is 'fully' detached and unmapped,
4790 * undo the VM accounting.
4793 atomic_long_sub((size >> PAGE_SHIFT) + 1, &mmap_user->locked_vm);
4794 vma->vm_mm->pinned_vm -= mmap_locked;
4795 free_uid(mmap_user);
4798 ring_buffer_put(rb); /* could be last */
4801 static const struct vm_operations_struct perf_mmap_vmops = {
4802 .open = perf_mmap_open,
4803 .close = perf_mmap_close, /* non mergable */
4804 .fault = perf_mmap_fault,
4805 .page_mkwrite = perf_mmap_fault,
4808 static int perf_mmap(struct file *file, struct vm_area_struct *vma)
4810 struct perf_event *event = file->private_data;
4811 unsigned long user_locked, user_lock_limit;
4812 struct user_struct *user = current_user();
4813 unsigned long locked, lock_limit;
4814 struct ring_buffer *rb = NULL;
4815 unsigned long vma_size;
4816 unsigned long nr_pages;
4817 long user_extra = 0, extra = 0;
4818 int ret = 0, flags = 0;
4821 * Don't allow mmap() of inherited per-task counters. This would
4822 * create a performance issue due to all children writing to the
4825 if (event->cpu == -1 && event->attr.inherit)
4828 if (!(vma->vm_flags & VM_SHARED))
4831 vma_size = vma->vm_end - vma->vm_start;
4833 if (vma->vm_pgoff == 0) {
4834 nr_pages = (vma_size / PAGE_SIZE) - 1;
4837 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4838 * mapped, all subsequent mappings should have the same size
4839 * and offset. Must be above the normal perf buffer.
4841 u64 aux_offset, aux_size;
4846 nr_pages = vma_size / PAGE_SIZE;
4848 mutex_lock(&event->mmap_mutex);
4855 aux_offset = ACCESS_ONCE(rb->user_page->aux_offset);
4856 aux_size = ACCESS_ONCE(rb->user_page->aux_size);
4858 if (aux_offset < perf_data_size(rb) + PAGE_SIZE)
4861 if (aux_offset != vma->vm_pgoff << PAGE_SHIFT)
4864 /* already mapped with a different offset */
4865 if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff)
4868 if (aux_size != vma_size || aux_size != nr_pages * PAGE_SIZE)
4871 /* already mapped with a different size */
4872 if (rb_has_aux(rb) && rb->aux_nr_pages != nr_pages)
4875 if (!is_power_of_2(nr_pages))
4878 if (!atomic_inc_not_zero(&rb->mmap_count))
4881 if (rb_has_aux(rb)) {
4882 atomic_inc(&rb->aux_mmap_count);
4887 atomic_set(&rb->aux_mmap_count, 1);
4888 user_extra = nr_pages;
4894 * If we have rb pages ensure they're a power-of-two number, so we
4895 * can do bitmasks instead of modulo.
4897 if (nr_pages != 0 && !is_power_of_2(nr_pages))
4900 if (vma_size != PAGE_SIZE * (1 + nr_pages))
4903 WARN_ON_ONCE(event->ctx->parent_ctx);
4905 mutex_lock(&event->mmap_mutex);
4907 if (event->rb->nr_pages != nr_pages) {
4912 if (!atomic_inc_not_zero(&event->rb->mmap_count)) {
4914 * Raced against perf_mmap_close() through
4915 * perf_event_set_output(). Try again, hope for better
4918 mutex_unlock(&event->mmap_mutex);
4925 user_extra = nr_pages + 1;
4928 user_lock_limit = sysctl_perf_event_mlock >> (PAGE_SHIFT - 10);
4931 * Increase the limit linearly with more CPUs:
4933 user_lock_limit *= num_online_cpus();
4935 user_locked = atomic_long_read(&user->locked_vm) + user_extra;
4937 if (user_locked > user_lock_limit)
4938 extra = user_locked - user_lock_limit;
4940 lock_limit = rlimit(RLIMIT_MEMLOCK);
4941 lock_limit >>= PAGE_SHIFT;
4942 locked = vma->vm_mm->pinned_vm + extra;
4944 if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
4945 !capable(CAP_IPC_LOCK)) {
4950 WARN_ON(!rb && event->rb);
4952 if (vma->vm_flags & VM_WRITE)
4953 flags |= RING_BUFFER_WRITABLE;
4956 rb = rb_alloc(nr_pages,
4957 event->attr.watermark ? event->attr.wakeup_watermark : 0,
4965 atomic_set(&rb->mmap_count, 1);
4966 rb->mmap_user = get_current_user();
4967 rb->mmap_locked = extra;
4969 ring_buffer_attach(event, rb);
4971 perf_event_init_userpage(event);
4972 perf_event_update_userpage(event);
4974 ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages,
4975 event->attr.aux_watermark, flags);
4977 rb->aux_mmap_locked = extra;
4982 atomic_long_add(user_extra, &user->locked_vm);
4983 vma->vm_mm->pinned_vm += extra;
4985 atomic_inc(&event->mmap_count);
4987 atomic_dec(&rb->mmap_count);
4990 mutex_unlock(&event->mmap_mutex);
4993 * Since pinned accounting is per vm we cannot allow fork() to copy our
4996 vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP;
4997 vma->vm_ops = &perf_mmap_vmops;
4999 if (event->pmu->event_mapped)
5000 event->pmu->event_mapped(event);
5005 static int perf_fasync(int fd, struct file *filp, int on)
5007 struct inode *inode = file_inode(filp);
5008 struct perf_event *event = filp->private_data;
5011 mutex_lock(&inode->i_mutex);
5012 retval = fasync_helper(fd, filp, on, &event->fasync);
5013 mutex_unlock(&inode->i_mutex);
5021 static const struct file_operations perf_fops = {
5022 .llseek = no_llseek,
5023 .release = perf_release,
5026 .unlocked_ioctl = perf_ioctl,
5027 .compat_ioctl = perf_compat_ioctl,
5029 .fasync = perf_fasync,
5035 * If there's data, ensure we set the poll() state and publish everything
5036 * to user-space before waking everybody up.
5039 static inline struct fasync_struct **perf_event_fasync(struct perf_event *event)
5041 /* only the parent has fasync state */
5043 event = event->parent;
5044 return &event->fasync;
5047 void perf_event_wakeup(struct perf_event *event)
5049 ring_buffer_wakeup(event);
5051 if (event->pending_kill) {
5052 kill_fasync(perf_event_fasync(event), SIGIO, event->pending_kill);
5053 event->pending_kill = 0;
5057 static void perf_pending_event(struct irq_work *entry)
5059 struct perf_event *event = container_of(entry,
5060 struct perf_event, pending);
5063 rctx = perf_swevent_get_recursion_context();
5065 * If we 'fail' here, that's OK, it means recursion is already disabled
5066 * and we won't recurse 'further'.
5069 if (event->pending_disable) {
5070 event->pending_disable = 0;
5071 __perf_event_disable(event);
5074 if (event->pending_wakeup) {
5075 event->pending_wakeup = 0;
5076 perf_event_wakeup(event);
5080 perf_swevent_put_recursion_context(rctx);
5084 * We assume there is only KVM supporting the callbacks.
5085 * Later on, we might change it to a list if there is
5086 * another virtualization implementation supporting the callbacks.
5088 struct perf_guest_info_callbacks *perf_guest_cbs;
5090 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
5092 perf_guest_cbs = cbs;
5095 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks);
5097 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs)
5099 perf_guest_cbs = NULL;
5102 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks);
5105 perf_output_sample_regs(struct perf_output_handle *handle,
5106 struct pt_regs *regs, u64 mask)
5110 for_each_set_bit(bit, (const unsigned long *) &mask,
5111 sizeof(mask) * BITS_PER_BYTE) {
5114 val = perf_reg_value(regs, bit);
5115 perf_output_put(handle, val);
5119 static void perf_sample_regs_user(struct perf_regs *regs_user,
5120 struct pt_regs *regs,
5121 struct pt_regs *regs_user_copy)
5123 if (user_mode(regs)) {
5124 regs_user->abi = perf_reg_abi(current);
5125 regs_user->regs = regs;
5126 } else if (current->mm) {
5127 perf_get_regs_user(regs_user, regs, regs_user_copy);
5129 regs_user->abi = PERF_SAMPLE_REGS_ABI_NONE;
5130 regs_user->regs = NULL;
5134 static void perf_sample_regs_intr(struct perf_regs *regs_intr,
5135 struct pt_regs *regs)
5137 regs_intr->regs = regs;
5138 regs_intr->abi = perf_reg_abi(current);
5143 * Get remaining task size from user stack pointer.
5145 * It'd be better to take stack vma map and limit this more
5146 * precisly, but there's no way to get it safely under interrupt,
5147 * so using TASK_SIZE as limit.
5149 static u64 perf_ustack_task_size(struct pt_regs *regs)
5151 unsigned long addr = perf_user_stack_pointer(regs);
5153 if (!addr || addr >= TASK_SIZE)
5156 return TASK_SIZE - addr;
5160 perf_sample_ustack_size(u16 stack_size, u16 header_size,
5161 struct pt_regs *regs)
5165 /* No regs, no stack pointer, no dump. */
5170 * Check if we fit in with the requested stack size into the:
5172 * If we don't, we limit the size to the TASK_SIZE.
5174 * - remaining sample size
5175 * If we don't, we customize the stack size to
5176 * fit in to the remaining sample size.
5179 task_size = min((u64) USHRT_MAX, perf_ustack_task_size(regs));
5180 stack_size = min(stack_size, (u16) task_size);
5182 /* Current header size plus static size and dynamic size. */
5183 header_size += 2 * sizeof(u64);
5185 /* Do we fit in with the current stack dump size? */
5186 if ((u16) (header_size + stack_size) < header_size) {
5188 * If we overflow the maximum size for the sample,
5189 * we customize the stack dump size to fit in.
5191 stack_size = USHRT_MAX - header_size - sizeof(u64);
5192 stack_size = round_up(stack_size, sizeof(u64));
5199 perf_output_sample_ustack(struct perf_output_handle *handle, u64 dump_size,
5200 struct pt_regs *regs)
5202 /* Case of a kernel thread, nothing to dump */
5205 perf_output_put(handle, size);
5214 * - the size requested by user or the best one we can fit
5215 * in to the sample max size
5217 * - user stack dump data
5219 * - the actual dumped size
5223 perf_output_put(handle, dump_size);
5226 sp = perf_user_stack_pointer(regs);
5227 rem = __output_copy_user(handle, (void *) sp, dump_size);
5228 dyn_size = dump_size - rem;
5230 perf_output_skip(handle, rem);
5233 perf_output_put(handle, dyn_size);
5237 static void __perf_event_header__init_id(struct perf_event_header *header,
5238 struct perf_sample_data *data,
5239 struct perf_event *event)
5241 u64 sample_type = event->attr.sample_type;
5243 data->type = sample_type;
5244 header->size += event->id_header_size;
5246 if (sample_type & PERF_SAMPLE_TID) {
5247 /* namespace issues */
5248 data->tid_entry.pid = perf_event_pid(event, current);
5249 data->tid_entry.tid = perf_event_tid(event, current);
5252 if (sample_type & PERF_SAMPLE_TIME)
5253 data->time = perf_event_clock(event);
5255 if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER))
5256 data->id = primary_event_id(event);
5258 if (sample_type & PERF_SAMPLE_STREAM_ID)
5259 data->stream_id = event->id;
5261 if (sample_type & PERF_SAMPLE_CPU) {
5262 data->cpu_entry.cpu = raw_smp_processor_id();
5263 data->cpu_entry.reserved = 0;
5267 void perf_event_header__init_id(struct perf_event_header *header,
5268 struct perf_sample_data *data,
5269 struct perf_event *event)
5271 if (event->attr.sample_id_all)
5272 __perf_event_header__init_id(header, data, event);
5275 static void __perf_event__output_id_sample(struct perf_output_handle *handle,
5276 struct perf_sample_data *data)
5278 u64 sample_type = data->type;
5280 if (sample_type & PERF_SAMPLE_TID)
5281 perf_output_put(handle, data->tid_entry);
5283 if (sample_type & PERF_SAMPLE_TIME)
5284 perf_output_put(handle, data->time);
5286 if (sample_type & PERF_SAMPLE_ID)
5287 perf_output_put(handle, data->id);
5289 if (sample_type & PERF_SAMPLE_STREAM_ID)
5290 perf_output_put(handle, data->stream_id);
5292 if (sample_type & PERF_SAMPLE_CPU)
5293 perf_output_put(handle, data->cpu_entry);
5295 if (sample_type & PERF_SAMPLE_IDENTIFIER)
5296 perf_output_put(handle, data->id);
5299 void perf_event__output_id_sample(struct perf_event *event,
5300 struct perf_output_handle *handle,
5301 struct perf_sample_data *sample)
5303 if (event->attr.sample_id_all)
5304 __perf_event__output_id_sample(handle, sample);
5307 static void perf_output_read_one(struct perf_output_handle *handle,
5308 struct perf_event *event,
5309 u64 enabled, u64 running)
5311 u64 read_format = event->attr.read_format;
5315 values[n++] = perf_event_count(event);
5316 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
5317 values[n++] = enabled +
5318 atomic64_read(&event->child_total_time_enabled);
5320 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
5321 values[n++] = running +
5322 atomic64_read(&event->child_total_time_running);
5324 if (read_format & PERF_FORMAT_ID)
5325 values[n++] = primary_event_id(event);
5327 __output_copy(handle, values, n * sizeof(u64));
5331 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5333 static void perf_output_read_group(struct perf_output_handle *handle,
5334 struct perf_event *event,
5335 u64 enabled, u64 running)
5337 struct perf_event *leader = event->group_leader, *sub;
5338 u64 read_format = event->attr.read_format;
5342 values[n++] = 1 + leader->nr_siblings;
5344 if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
5345 values[n++] = enabled;
5347 if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
5348 values[n++] = running;
5350 if (leader != event)
5351 leader->pmu->read(leader);
5353 values[n++] = perf_event_count(leader);
5354 if (read_format & PERF_FORMAT_ID)
5355 values[n++] = primary_event_id(leader);
5357 __output_copy(handle, values, n * sizeof(u64));
5359 list_for_each_entry(sub, &leader->sibling_list, group_entry) {
5362 if ((sub != event) &&
5363 (sub->state == PERF_EVENT_STATE_ACTIVE))
5364 sub->pmu->read(sub);
5366 values[n++] = perf_event_count(sub);
5367 if (read_format & PERF_FORMAT_ID)
5368 values[n++] = primary_event_id(sub);
5370 __output_copy(handle, values, n * sizeof(u64));
5374 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5375 PERF_FORMAT_TOTAL_TIME_RUNNING)
5377 static void perf_output_read(struct perf_output_handle *handle,
5378 struct perf_event *event)
5380 u64 enabled = 0, running = 0, now;
5381 u64 read_format = event->attr.read_format;
5384 * compute total_time_enabled, total_time_running
5385 * based on snapshot values taken when the event
5386 * was last scheduled in.
5388 * we cannot simply called update_context_time()
5389 * because of locking issue as we are called in
5392 if (read_format & PERF_FORMAT_TOTAL_TIMES)
5393 calc_timer_values(event, &now, &enabled, &running);
5395 if (event->attr.read_format & PERF_FORMAT_GROUP)
5396 perf_output_read_group(handle, event, enabled, running);
5398 perf_output_read_one(handle, event, enabled, running);
5401 void perf_output_sample(struct perf_output_handle *handle,
5402 struct perf_event_header *header,
5403 struct perf_sample_data *data,
5404 struct perf_event *event)
5406 u64 sample_type = data->type;
5408 perf_output_put(handle, *header);
5410 if (sample_type & PERF_SAMPLE_IDENTIFIER)
5411 perf_output_put(handle, data->id);
5413 if (sample_type & PERF_SAMPLE_IP)
5414 perf_output_put(handle, data->ip);
5416 if (sample_type & PERF_SAMPLE_TID)
5417 perf_output_put(handle, data->tid_entry);
5419 if (sample_type & PERF_SAMPLE_TIME)
5420 perf_output_put(handle, data->time);
5422 if (sample_type & PERF_SAMPLE_ADDR)
5423 perf_output_put(handle, data->addr);
5425 if (sample_type & PERF_SAMPLE_ID)
5426 perf_output_put(handle, data->id);
5428 if (sample_type & PERF_SAMPLE_STREAM_ID)
5429 perf_output_put(handle, data->stream_id);
5431 if (sample_type & PERF_SAMPLE_CPU)
5432 perf_output_put(handle, data->cpu_entry);
5434 if (sample_type & PERF_SAMPLE_PERIOD)
5435 perf_output_put(handle, data->period);
5437 if (sample_type & PERF_SAMPLE_READ)
5438 perf_output_read(handle, event);
5440 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
5441 if (data->callchain) {
5444 if (data->callchain)
5445 size += data->callchain->nr;
5447 size *= sizeof(u64);
5449 __output_copy(handle, data->callchain, size);
5452 perf_output_put(handle, nr);
5456 if (sample_type & PERF_SAMPLE_RAW) {
5458 u32 raw_size = data->raw->size;
5459 u32 real_size = round_up(raw_size + sizeof(u32),
5460 sizeof(u64)) - sizeof(u32);
5463 perf_output_put(handle, real_size);
5464 __output_copy(handle, data->raw->data, raw_size);
5465 if (real_size - raw_size)
5466 __output_copy(handle, &zero, real_size - raw_size);
5472 .size = sizeof(u32),
5475 perf_output_put(handle, raw);
5479 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
5480 if (data->br_stack) {
5483 size = data->br_stack->nr
5484 * sizeof(struct perf_branch_entry);
5486 perf_output_put(handle, data->br_stack->nr);
5487 perf_output_copy(handle, data->br_stack->entries, size);
5490 * we always store at least the value of nr
5493 perf_output_put(handle, nr);
5497 if (sample_type & PERF_SAMPLE_REGS_USER) {
5498 u64 abi = data->regs_user.abi;
5501 * If there are no regs to dump, notice it through
5502 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5504 perf_output_put(handle, abi);
5507 u64 mask = event->attr.sample_regs_user;
5508 perf_output_sample_regs(handle,
5509 data->regs_user.regs,
5514 if (sample_type & PERF_SAMPLE_STACK_USER) {
5515 perf_output_sample_ustack(handle,
5516 data->stack_user_size,
5517 data->regs_user.regs);
5520 if (sample_type & PERF_SAMPLE_WEIGHT)
5521 perf_output_put(handle, data->weight);
5523 if (sample_type & PERF_SAMPLE_DATA_SRC)
5524 perf_output_put(handle, data->data_src.val);
5526 if (sample_type & PERF_SAMPLE_TRANSACTION)
5527 perf_output_put(handle, data->txn);
5529 if (sample_type & PERF_SAMPLE_REGS_INTR) {
5530 u64 abi = data->regs_intr.abi;
5532 * If there are no regs to dump, notice it through
5533 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5535 perf_output_put(handle, abi);
5538 u64 mask = event->attr.sample_regs_intr;
5540 perf_output_sample_regs(handle,
5541 data->regs_intr.regs,
5546 if (!event->attr.watermark) {
5547 int wakeup_events = event->attr.wakeup_events;
5549 if (wakeup_events) {
5550 struct ring_buffer *rb = handle->rb;
5551 int events = local_inc_return(&rb->events);
5553 if (events >= wakeup_events) {
5554 local_sub(wakeup_events, &rb->events);
5555 local_inc(&rb->wakeup);
5561 void perf_prepare_sample(struct perf_event_header *header,
5562 struct perf_sample_data *data,
5563 struct perf_event *event,
5564 struct pt_regs *regs)
5566 u64 sample_type = event->attr.sample_type;
5568 header->type = PERF_RECORD_SAMPLE;
5569 header->size = sizeof(*header) + event->header_size;
5572 header->misc |= perf_misc_flags(regs);
5574 __perf_event_header__init_id(header, data, event);
5576 if (sample_type & PERF_SAMPLE_IP)
5577 data->ip = perf_instruction_pointer(regs);
5579 if (sample_type & PERF_SAMPLE_CALLCHAIN) {
5582 data->callchain = perf_callchain(event, regs);
5584 if (data->callchain)
5585 size += data->callchain->nr;
5587 header->size += size * sizeof(u64);
5590 if (sample_type & PERF_SAMPLE_RAW) {
5591 int size = sizeof(u32);
5594 size += data->raw->size;
5596 size += sizeof(u32);
5598 header->size += round_up(size, sizeof(u64));
5601 if (sample_type & PERF_SAMPLE_BRANCH_STACK) {
5602 int size = sizeof(u64); /* nr */
5603 if (data->br_stack) {
5604 size += data->br_stack->nr
5605 * sizeof(struct perf_branch_entry);
5607 header->size += size;
5610 if (sample_type & (PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER))
5611 perf_sample_regs_user(&data->regs_user, regs,
5612 &data->regs_user_copy);
5614 if (sample_type & PERF_SAMPLE_REGS_USER) {
5615 /* regs dump ABI info */
5616 int size = sizeof(u64);
5618 if (data->regs_user.regs) {
5619 u64 mask = event->attr.sample_regs_user;
5620 size += hweight64(mask) * sizeof(u64);
5623 header->size += size;
5626 if (sample_type & PERF_SAMPLE_STACK_USER) {
5628 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5629 * processed as the last one or have additional check added
5630 * in case new sample type is added, because we could eat
5631 * up the rest of the sample size.
5633 u16 stack_size = event->attr.sample_stack_user;
5634 u16 size = sizeof(u64);
5636 stack_size = perf_sample_ustack_size(stack_size, header->size,
5637 data->regs_user.regs);
5640 * If there is something to dump, add space for the dump
5641 * itself and for the field that tells the dynamic size,
5642 * which is how many have been actually dumped.
5645 size += sizeof(u64) + stack_size;
5647 data->stack_user_size = stack_size;
5648 header->size += size;
5651 if (sample_type & PERF_SAMPLE_REGS_INTR) {
5652 /* regs dump ABI info */
5653 int size = sizeof(u64);
5655 perf_sample_regs_intr(&data->regs_intr, regs);
5657 if (data->regs_intr.regs) {
5658 u64 mask = event->attr.sample_regs_intr;
5660 size += hweight64(mask) * sizeof(u64);
5663 header->size += size;
5667 void perf_event_output(struct perf_event *event,
5668 struct perf_sample_data *data,
5669 struct pt_regs *regs)
5671 struct perf_output_handle handle;
5672 struct perf_event_header header;
5674 /* protect the callchain buffers */
5677 perf_prepare_sample(&header, data, event, regs);
5679 if (perf_output_begin(&handle, event, header.size))
5682 perf_output_sample(&handle, &header, data, event);
5684 perf_output_end(&handle);
5694 struct perf_read_event {
5695 struct perf_event_header header;
5702 perf_event_read_event(struct perf_event *event,
5703 struct task_struct *task)
5705 struct perf_output_handle handle;
5706 struct perf_sample_data sample;
5707 struct perf_read_event read_event = {
5709 .type = PERF_RECORD_READ,
5711 .size = sizeof(read_event) + event->read_size,
5713 .pid = perf_event_pid(event, task),
5714 .tid = perf_event_tid(event, task),
5718 perf_event_header__init_id(&read_event.header, &sample, event);
5719 ret = perf_output_begin(&handle, event, read_event.header.size);
5723 perf_output_put(&handle, read_event);
5724 perf_output_read(&handle, event);
5725 perf_event__output_id_sample(event, &handle, &sample);
5727 perf_output_end(&handle);
5730 typedef void (perf_event_aux_output_cb)(struct perf_event *event, void *data);
5733 perf_event_aux_ctx(struct perf_event_context *ctx,
5734 perf_event_aux_output_cb output,
5737 struct perf_event *event;
5739 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
5740 if (event->state < PERF_EVENT_STATE_INACTIVE)
5742 if (!event_filter_match(event))
5744 output(event, data);
5749 perf_event_aux_task_ctx(perf_event_aux_output_cb output, void *data,
5750 struct perf_event_context *task_ctx)
5754 perf_event_aux_ctx(task_ctx, output, data);
5760 perf_event_aux(perf_event_aux_output_cb output, void *data,
5761 struct perf_event_context *task_ctx)
5763 struct perf_cpu_context *cpuctx;
5764 struct perf_event_context *ctx;
5769 * If we have task_ctx != NULL we only notify
5770 * the task context itself. The task_ctx is set
5771 * only for EXIT events before releasing task
5775 perf_event_aux_task_ctx(output, data, task_ctx);
5780 list_for_each_entry_rcu(pmu, &pmus, entry) {
5781 cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
5782 if (cpuctx->unique_pmu != pmu)
5784 perf_event_aux_ctx(&cpuctx->ctx, output, data);
5785 ctxn = pmu->task_ctx_nr;
5788 ctx = rcu_dereference(current->perf_event_ctxp[ctxn]);
5790 perf_event_aux_ctx(ctx, output, data);
5792 put_cpu_ptr(pmu->pmu_cpu_context);
5797 struct remote_output {
5798 struct ring_buffer *rb;
5802 static void __perf_event_output_stop(struct perf_event *event, void *data)
5804 struct perf_event *parent = event->parent;
5805 struct remote_output *ro = data;
5806 struct ring_buffer *rb = ro->rb;
5808 if (!has_aux(event))
5815 * In case of inheritance, it will be the parent that links to the
5816 * ring-buffer, but it will be the child that's actually using it:
5818 if (rcu_dereference(parent->rb) == rb)
5819 ro->err = __perf_event_stop(event);
5822 static int __perf_pmu_output_stop(void *info)
5824 struct perf_event *event = info;
5825 struct pmu *pmu = event->pmu;
5826 struct perf_cpu_context *cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
5827 struct remote_output ro = {
5832 perf_event_aux_ctx(&cpuctx->ctx, __perf_event_output_stop, &ro);
5833 if (cpuctx->task_ctx)
5834 perf_event_aux_ctx(cpuctx->task_ctx, __perf_event_output_stop,
5841 static void perf_pmu_output_stop(struct perf_event *event)
5843 struct perf_event *iter;
5848 list_for_each_entry_rcu(iter, &event->rb->event_list, rb_entry) {
5850 * For per-CPU events, we need to make sure that neither they
5851 * nor their children are running; for cpu==-1 events it's
5852 * sufficient to stop the event itself if it's active, since
5853 * it can't have children.
5857 cpu = READ_ONCE(iter->oncpu);
5862 err = cpu_function_call(cpu, __perf_pmu_output_stop, event);
5863 if (err == -EAGAIN) {
5872 * task tracking -- fork/exit
5874 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5877 struct perf_task_event {
5878 struct task_struct *task;
5879 struct perf_event_context *task_ctx;
5882 struct perf_event_header header;
5892 static int perf_event_task_match(struct perf_event *event)
5894 return event->attr.comm || event->attr.mmap ||
5895 event->attr.mmap2 || event->attr.mmap_data ||
5899 static void perf_event_task_output(struct perf_event *event,
5902 struct perf_task_event *task_event = data;
5903 struct perf_output_handle handle;
5904 struct perf_sample_data sample;
5905 struct task_struct *task = task_event->task;
5906 int ret, size = task_event->event_id.header.size;
5908 if (!perf_event_task_match(event))
5911 perf_event_header__init_id(&task_event->event_id.header, &sample, event);
5913 ret = perf_output_begin(&handle, event,
5914 task_event->event_id.header.size);
5918 task_event->event_id.pid = perf_event_pid(event, task);
5919 task_event->event_id.ppid = perf_event_pid(event, current);
5921 task_event->event_id.tid = perf_event_tid(event, task);
5922 task_event->event_id.ptid = perf_event_tid(event, current);
5924 task_event->event_id.time = perf_event_clock(event);
5926 perf_output_put(&handle, task_event->event_id);
5928 perf_event__output_id_sample(event, &handle, &sample);
5930 perf_output_end(&handle);
5932 task_event->event_id.header.size = size;
5935 static void perf_event_task(struct task_struct *task,
5936 struct perf_event_context *task_ctx,
5939 struct perf_task_event task_event;
5941 if (!atomic_read(&nr_comm_events) &&
5942 !atomic_read(&nr_mmap_events) &&
5943 !atomic_read(&nr_task_events))
5946 task_event = (struct perf_task_event){
5948 .task_ctx = task_ctx,
5951 .type = new ? PERF_RECORD_FORK : PERF_RECORD_EXIT,
5953 .size = sizeof(task_event.event_id),
5963 perf_event_aux(perf_event_task_output,
5968 void perf_event_fork(struct task_struct *task)
5970 perf_event_task(task, NULL, 1);
5977 struct perf_comm_event {
5978 struct task_struct *task;
5983 struct perf_event_header header;
5990 static int perf_event_comm_match(struct perf_event *event)
5992 return event->attr.comm;
5995 static void perf_event_comm_output(struct perf_event *event,
5998 struct perf_comm_event *comm_event = data;
5999 struct perf_output_handle handle;
6000 struct perf_sample_data sample;
6001 int size = comm_event->event_id.header.size;
6004 if (!perf_event_comm_match(event))
6007 perf_event_header__init_id(&comm_event->event_id.header, &sample, event);
6008 ret = perf_output_begin(&handle, event,
6009 comm_event->event_id.header.size);
6014 comm_event->event_id.pid = perf_event_pid(event, comm_event->task);
6015 comm_event->event_id.tid = perf_event_tid(event, comm_event->task);
6017 perf_output_put(&handle, comm_event->event_id);
6018 __output_copy(&handle, comm_event->comm,
6019 comm_event->comm_size);
6021 perf_event__output_id_sample(event, &handle, &sample);
6023 perf_output_end(&handle);
6025 comm_event->event_id.header.size = size;
6028 static void perf_event_comm_event(struct perf_comm_event *comm_event)
6030 char comm[TASK_COMM_LEN];
6033 memset(comm, 0, sizeof(comm));
6034 strlcpy(comm, comm_event->task->comm, sizeof(comm));
6035 size = ALIGN(strlen(comm)+1, sizeof(u64));
6037 comm_event->comm = comm;
6038 comm_event->comm_size = size;
6040 comm_event->event_id.header.size = sizeof(comm_event->event_id) + size;
6042 perf_event_aux(perf_event_comm_output,
6047 void perf_event_comm(struct task_struct *task, bool exec)
6049 struct perf_comm_event comm_event;
6051 if (!atomic_read(&nr_comm_events))
6054 comm_event = (struct perf_comm_event){
6060 .type = PERF_RECORD_COMM,
6061 .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0,
6069 perf_event_comm_event(&comm_event);
6076 struct perf_mmap_event {
6077 struct vm_area_struct *vma;
6079 const char *file_name;
6087 struct perf_event_header header;
6097 static int perf_event_mmap_match(struct perf_event *event,
6100 struct perf_mmap_event *mmap_event = data;
6101 struct vm_area_struct *vma = mmap_event->vma;
6102 int executable = vma->vm_flags & VM_EXEC;
6104 return (!executable && event->attr.mmap_data) ||
6105 (executable && (event->attr.mmap || event->attr.mmap2));
6108 static void perf_event_mmap_output(struct perf_event *event,
6111 struct perf_mmap_event *mmap_event = data;
6112 struct perf_output_handle handle;
6113 struct perf_sample_data sample;
6114 int size = mmap_event->event_id.header.size;
6117 if (!perf_event_mmap_match(event, data))
6120 if (event->attr.mmap2) {
6121 mmap_event->event_id.header.type = PERF_RECORD_MMAP2;
6122 mmap_event->event_id.header.size += sizeof(mmap_event->maj);
6123 mmap_event->event_id.header.size += sizeof(mmap_event->min);
6124 mmap_event->event_id.header.size += sizeof(mmap_event->ino);
6125 mmap_event->event_id.header.size += sizeof(mmap_event->ino_generation);
6126 mmap_event->event_id.header.size += sizeof(mmap_event->prot);
6127 mmap_event->event_id.header.size += sizeof(mmap_event->flags);
6130 perf_event_header__init_id(&mmap_event->event_id.header, &sample, event);
6131 ret = perf_output_begin(&handle, event,
6132 mmap_event->event_id.header.size);
6136 mmap_event->event_id.pid = perf_event_pid(event, current);
6137 mmap_event->event_id.tid = perf_event_tid(event, current);
6139 perf_output_put(&handle, mmap_event->event_id);
6141 if (event->attr.mmap2) {
6142 perf_output_put(&handle, mmap_event->maj);
6143 perf_output_put(&handle, mmap_event->min);
6144 perf_output_put(&handle, mmap_event->ino);
6145 perf_output_put(&handle, mmap_event->ino_generation);
6146 perf_output_put(&handle, mmap_event->prot);
6147 perf_output_put(&handle, mmap_event->flags);
6150 __output_copy(&handle, mmap_event->file_name,
6151 mmap_event->file_size);
6153 perf_event__output_id_sample(event, &handle, &sample);
6155 perf_output_end(&handle);
6157 mmap_event->event_id.header.size = size;
6160 static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
6162 struct vm_area_struct *vma = mmap_event->vma;
6163 struct file *file = vma->vm_file;
6164 int maj = 0, min = 0;
6165 u64 ino = 0, gen = 0;
6166 u32 prot = 0, flags = 0;
6172 if (vma->vm_flags & VM_READ)
6174 if (vma->vm_flags & VM_WRITE)
6176 if (vma->vm_flags & VM_EXEC)
6179 if (vma->vm_flags & VM_MAYSHARE)
6182 flags = MAP_PRIVATE;
6184 if (vma->vm_flags & VM_DENYWRITE)
6185 flags |= MAP_DENYWRITE;
6186 if (vma->vm_flags & VM_MAYEXEC)
6187 flags |= MAP_EXECUTABLE;
6188 if (vma->vm_flags & VM_LOCKED)
6189 flags |= MAP_LOCKED;
6190 if (vma->vm_flags & VM_HUGETLB)
6191 flags |= MAP_HUGETLB;
6194 struct inode *inode;
6197 buf = kmalloc(PATH_MAX, GFP_KERNEL);
6203 * d_path() works from the end of the rb backwards, so we
6204 * need to add enough zero bytes after the string to handle
6205 * the 64bit alignment we do later.
6207 name = file_path(file, buf, PATH_MAX - sizeof(u64));
6212 inode = file_inode(vma->vm_file);
6213 dev = inode->i_sb->s_dev;
6215 gen = inode->i_generation;
6221 if (vma->vm_ops && vma->vm_ops->name) {
6222 name = (char *) vma->vm_ops->name(vma);
6227 name = (char *)arch_vma_name(vma);
6231 if (vma->vm_start <= vma->vm_mm->start_brk &&
6232 vma->vm_end >= vma->vm_mm->brk) {
6236 if (vma->vm_start <= vma->vm_mm->start_stack &&
6237 vma->vm_end >= vma->vm_mm->start_stack) {
6247 strlcpy(tmp, name, sizeof(tmp));
6251 * Since our buffer works in 8 byte units we need to align our string
6252 * size to a multiple of 8. However, we must guarantee the tail end is
6253 * zero'd out to avoid leaking random bits to userspace.
6255 size = strlen(name)+1;
6256 while (!IS_ALIGNED(size, sizeof(u64)))
6257 name[size++] = '\0';
6259 mmap_event->file_name = name;
6260 mmap_event->file_size = size;
6261 mmap_event->maj = maj;
6262 mmap_event->min = min;
6263 mmap_event->ino = ino;
6264 mmap_event->ino_generation = gen;
6265 mmap_event->prot = prot;
6266 mmap_event->flags = flags;
6268 if (!(vma->vm_flags & VM_EXEC))
6269 mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;
6271 mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;
6273 perf_event_aux(perf_event_mmap_output,
6280 void perf_event_mmap(struct vm_area_struct *vma)
6282 struct perf_mmap_event mmap_event;
6284 if (!atomic_read(&nr_mmap_events))
6287 mmap_event = (struct perf_mmap_event){
6293 .type = PERF_RECORD_MMAP,
6294 .misc = PERF_RECORD_MISC_USER,
6299 .start = vma->vm_start,
6300 .len = vma->vm_end - vma->vm_start,
6301 .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT,
6303 /* .maj (attr_mmap2 only) */
6304 /* .min (attr_mmap2 only) */
6305 /* .ino (attr_mmap2 only) */
6306 /* .ino_generation (attr_mmap2 only) */
6307 /* .prot (attr_mmap2 only) */
6308 /* .flags (attr_mmap2 only) */
6311 perf_event_mmap_event(&mmap_event);
6314 void perf_event_aux_event(struct perf_event *event, unsigned long head,
6315 unsigned long size, u64 flags)
6317 struct perf_output_handle handle;
6318 struct perf_sample_data sample;
6319 struct perf_aux_event {
6320 struct perf_event_header header;
6326 .type = PERF_RECORD_AUX,
6328 .size = sizeof(rec),
6336 perf_event_header__init_id(&rec.header, &sample, event);
6337 ret = perf_output_begin(&handle, event, rec.header.size);
6342 perf_output_put(&handle, rec);
6343 perf_event__output_id_sample(event, &handle, &sample);
6345 perf_output_end(&handle);
6349 * Lost/dropped samples logging
6351 void perf_log_lost_samples(struct perf_event *event, u64 lost)
6353 struct perf_output_handle handle;
6354 struct perf_sample_data sample;
6358 struct perf_event_header header;
6360 } lost_samples_event = {
6362 .type = PERF_RECORD_LOST_SAMPLES,
6364 .size = sizeof(lost_samples_event),
6369 perf_event_header__init_id(&lost_samples_event.header, &sample, event);
6371 ret = perf_output_begin(&handle, event,
6372 lost_samples_event.header.size);
6376 perf_output_put(&handle, lost_samples_event);
6377 perf_event__output_id_sample(event, &handle, &sample);
6378 perf_output_end(&handle);
6382 * context_switch tracking
6385 struct perf_switch_event {
6386 struct task_struct *task;
6387 struct task_struct *next_prev;
6390 struct perf_event_header header;
6396 static int perf_event_switch_match(struct perf_event *event)
6398 return event->attr.context_switch;
6401 static void perf_event_switch_output(struct perf_event *event, void *data)
6403 struct perf_switch_event *se = data;
6404 struct perf_output_handle handle;
6405 struct perf_sample_data sample;
6408 if (!perf_event_switch_match(event))
6411 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6412 if (event->ctx->task) {
6413 se->event_id.header.type = PERF_RECORD_SWITCH;
6414 se->event_id.header.size = sizeof(se->event_id.header);
6416 se->event_id.header.type = PERF_RECORD_SWITCH_CPU_WIDE;
6417 se->event_id.header.size = sizeof(se->event_id);
6418 se->event_id.next_prev_pid =
6419 perf_event_pid(event, se->next_prev);
6420 se->event_id.next_prev_tid =
6421 perf_event_tid(event, se->next_prev);
6424 perf_event_header__init_id(&se->event_id.header, &sample, event);
6426 ret = perf_output_begin(&handle, event, se->event_id.header.size);
6430 if (event->ctx->task)
6431 perf_output_put(&handle, se->event_id.header);
6433 perf_output_put(&handle, se->event_id);
6435 perf_event__output_id_sample(event, &handle, &sample);
6437 perf_output_end(&handle);
6440 static void perf_event_switch(struct task_struct *task,
6441 struct task_struct *next_prev, bool sched_in)
6443 struct perf_switch_event switch_event;
6445 /* N.B. caller checks nr_switch_events != 0 */
6447 switch_event = (struct perf_switch_event){
6449 .next_prev = next_prev,
6453 .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT,
6456 /* .next_prev_pid */
6457 /* .next_prev_tid */
6461 perf_event_aux(perf_event_switch_output,
6467 * IRQ throttle logging
6470 static void perf_log_throttle(struct perf_event *event, int enable)
6472 struct perf_output_handle handle;
6473 struct perf_sample_data sample;
6477 struct perf_event_header header;
6481 } throttle_event = {
6483 .type = PERF_RECORD_THROTTLE,
6485 .size = sizeof(throttle_event),
6487 .time = perf_event_clock(event),
6488 .id = primary_event_id(event),
6489 .stream_id = event->id,
6493 throttle_event.header.type = PERF_RECORD_UNTHROTTLE;
6495 perf_event_header__init_id(&throttle_event.header, &sample, event);
6497 ret = perf_output_begin(&handle, event,
6498 throttle_event.header.size);
6502 perf_output_put(&handle, throttle_event);
6503 perf_event__output_id_sample(event, &handle, &sample);
6504 perf_output_end(&handle);
6507 static void perf_log_itrace_start(struct perf_event *event)
6509 struct perf_output_handle handle;
6510 struct perf_sample_data sample;
6511 struct perf_aux_event {
6512 struct perf_event_header header;
6519 event = event->parent;
6521 if (!(event->pmu->capabilities & PERF_PMU_CAP_ITRACE) ||
6522 event->hw.itrace_started)
6525 rec.header.type = PERF_RECORD_ITRACE_START;
6526 rec.header.misc = 0;
6527 rec.header.size = sizeof(rec);
6528 rec.pid = perf_event_pid(event, current);
6529 rec.tid = perf_event_tid(event, current);
6531 perf_event_header__init_id(&rec.header, &sample, event);
6532 ret = perf_output_begin(&handle, event, rec.header.size);
6537 perf_output_put(&handle, rec);
6538 perf_event__output_id_sample(event, &handle, &sample);
6540 perf_output_end(&handle);
6544 * Generic event overflow handling, sampling.
6547 static int __perf_event_overflow(struct perf_event *event,
6548 int throttle, struct perf_sample_data *data,
6549 struct pt_regs *regs)
6551 int events = atomic_read(&event->event_limit);
6552 struct hw_perf_event *hwc = &event->hw;
6557 * Non-sampling counters might still use the PMI to fold short
6558 * hardware counters, ignore those.
6560 if (unlikely(!is_sampling_event(event)))
6563 seq = __this_cpu_read(perf_throttled_seq);
6564 if (seq != hwc->interrupts_seq) {
6565 hwc->interrupts_seq = seq;
6566 hwc->interrupts = 1;
6569 if (unlikely(throttle
6570 && hwc->interrupts >= max_samples_per_tick)) {
6571 __this_cpu_inc(perf_throttled_count);
6572 hwc->interrupts = MAX_INTERRUPTS;
6573 perf_log_throttle(event, 0);
6574 tick_nohz_full_kick();
6579 if (event->attr.freq) {
6580 u64 now = perf_clock();
6581 s64 delta = now - hwc->freq_time_stamp;
6583 hwc->freq_time_stamp = now;
6585 if (delta > 0 && delta < 2*TICK_NSEC)
6586 perf_adjust_period(event, delta, hwc->last_period, true);
6590 * XXX event_limit might not quite work as expected on inherited
6594 event->pending_kill = POLL_IN;
6595 if (events && atomic_dec_and_test(&event->event_limit)) {
6597 event->pending_kill = POLL_HUP;
6598 event->pending_disable = 1;
6599 irq_work_queue(&event->pending);
6602 if (event->overflow_handler)
6603 event->overflow_handler(event, data, regs);
6605 perf_event_output(event, data, regs);
6607 if (*perf_event_fasync(event) && event->pending_kill) {
6608 event->pending_wakeup = 1;
6609 irq_work_queue(&event->pending);
6615 int perf_event_overflow(struct perf_event *event,
6616 struct perf_sample_data *data,
6617 struct pt_regs *regs)
6619 return __perf_event_overflow(event, 1, data, regs);
6623 * Generic software event infrastructure
6626 struct swevent_htable {
6627 struct swevent_hlist *swevent_hlist;
6628 struct mutex hlist_mutex;
6631 /* Recursion avoidance in each contexts */
6632 int recursion[PERF_NR_CONTEXTS];
6635 static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
6638 * We directly increment event->count and keep a second value in
6639 * event->hw.period_left to count intervals. This period event
6640 * is kept in the range [-sample_period, 0] so that we can use the
6644 u64 perf_swevent_set_period(struct perf_event *event)
6646 struct hw_perf_event *hwc = &event->hw;
6647 u64 period = hwc->last_period;
6651 hwc->last_period = hwc->sample_period;
6654 old = val = local64_read(&hwc->period_left);
6658 nr = div64_u64(period + val, period);
6659 offset = nr * period;
6661 if (local64_cmpxchg(&hwc->period_left, old, val) != old)
6667 static void perf_swevent_overflow(struct perf_event *event, u64 overflow,
6668 struct perf_sample_data *data,
6669 struct pt_regs *regs)
6671 struct hw_perf_event *hwc = &event->hw;
6675 overflow = perf_swevent_set_period(event);
6677 if (hwc->interrupts == MAX_INTERRUPTS)
6680 for (; overflow; overflow--) {
6681 if (__perf_event_overflow(event, throttle,
6684 * We inhibit the overflow from happening when
6685 * hwc->interrupts == MAX_INTERRUPTS.
6693 static void perf_swevent_event(struct perf_event *event, u64 nr,
6694 struct perf_sample_data *data,
6695 struct pt_regs *regs)
6697 struct hw_perf_event *hwc = &event->hw;
6699 local64_add(nr, &event->count);
6704 if (!is_sampling_event(event))
6707 if ((event->attr.sample_type & PERF_SAMPLE_PERIOD) && !event->attr.freq) {
6709 return perf_swevent_overflow(event, 1, data, regs);
6711 data->period = event->hw.last_period;
6713 if (nr == 1 && hwc->sample_period == 1 && !event->attr.freq)
6714 return perf_swevent_overflow(event, 1, data, regs);
6716 if (local64_add_negative(nr, &hwc->period_left))
6719 perf_swevent_overflow(event, 0, data, regs);
6722 static int perf_exclude_event(struct perf_event *event,
6723 struct pt_regs *regs)
6725 if (event->hw.state & PERF_HES_STOPPED)
6729 if (event->attr.exclude_user && user_mode(regs))
6732 if (event->attr.exclude_kernel && !user_mode(regs))
6739 static int perf_swevent_match(struct perf_event *event,
6740 enum perf_type_id type,
6742 struct perf_sample_data *data,
6743 struct pt_regs *regs)
6745 if (event->attr.type != type)
6748 if (event->attr.config != event_id)
6751 if (perf_exclude_event(event, regs))
6757 static inline u64 swevent_hash(u64 type, u32 event_id)
6759 u64 val = event_id | (type << 32);
6761 return hash_64(val, SWEVENT_HLIST_BITS);
6764 static inline struct hlist_head *
6765 __find_swevent_head(struct swevent_hlist *hlist, u64 type, u32 event_id)
6767 u64 hash = swevent_hash(type, event_id);
6769 return &hlist->heads[hash];
6772 /* For the read side: events when they trigger */
6773 static inline struct hlist_head *
6774 find_swevent_head_rcu(struct swevent_htable *swhash, u64 type, u32 event_id)
6776 struct swevent_hlist *hlist;
6778 hlist = rcu_dereference(swhash->swevent_hlist);
6782 return __find_swevent_head(hlist, type, event_id);
6785 /* For the event head insertion and removal in the hlist */
6786 static inline struct hlist_head *
6787 find_swevent_head(struct swevent_htable *swhash, struct perf_event *event)
6789 struct swevent_hlist *hlist;
6790 u32 event_id = event->attr.config;
6791 u64 type = event->attr.type;
6794 * Event scheduling is always serialized against hlist allocation
6795 * and release. Which makes the protected version suitable here.
6796 * The context lock guarantees that.
6798 hlist = rcu_dereference_protected(swhash->swevent_hlist,
6799 lockdep_is_held(&event->ctx->lock));
6803 return __find_swevent_head(hlist, type, event_id);
6806 static void do_perf_sw_event(enum perf_type_id type, u32 event_id,
6808 struct perf_sample_data *data,
6809 struct pt_regs *regs)
6811 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
6812 struct perf_event *event;
6813 struct hlist_head *head;
6816 head = find_swevent_head_rcu(swhash, type, event_id);
6820 hlist_for_each_entry_rcu(event, head, hlist_entry) {
6821 if (perf_swevent_match(event, type, event_id, data, regs))
6822 perf_swevent_event(event, nr, data, regs);
6828 DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]);
6830 int perf_swevent_get_recursion_context(void)
6832 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
6834 return get_recursion_context(swhash->recursion);
6836 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
6838 inline void perf_swevent_put_recursion_context(int rctx)
6840 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
6842 put_recursion_context(swhash->recursion, rctx);
6845 void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
6847 struct perf_sample_data data;
6849 if (WARN_ON_ONCE(!regs))
6852 perf_sample_data_init(&data, addr, 0);
6853 do_perf_sw_event(PERF_TYPE_SOFTWARE, event_id, nr, &data, regs);
6856 void __perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
6860 preempt_disable_notrace();
6861 rctx = perf_swevent_get_recursion_context();
6862 if (unlikely(rctx < 0))
6865 ___perf_sw_event(event_id, nr, regs, addr);
6867 perf_swevent_put_recursion_context(rctx);
6869 preempt_enable_notrace();
6872 static void perf_swevent_read(struct perf_event *event)
6876 static int perf_swevent_add(struct perf_event *event, int flags)
6878 struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
6879 struct hw_perf_event *hwc = &event->hw;
6880 struct hlist_head *head;
6882 if (is_sampling_event(event)) {
6883 hwc->last_period = hwc->sample_period;
6884 perf_swevent_set_period(event);
6887 hwc->state = !(flags & PERF_EF_START);
6889 head = find_swevent_head(swhash, event);
6890 if (WARN_ON_ONCE(!head))
6893 hlist_add_head_rcu(&event->hlist_entry, head);
6894 perf_event_update_userpage(event);
6899 static void perf_swevent_del(struct perf_event *event, int flags)
6901 hlist_del_rcu(&event->hlist_entry);
6904 static void perf_swevent_start(struct perf_event *event, int flags)
6906 event->hw.state = 0;
6909 static void perf_swevent_stop(struct perf_event *event, int flags)
6911 event->hw.state = PERF_HES_STOPPED;
6914 /* Deref the hlist from the update side */
6915 static inline struct swevent_hlist *
6916 swevent_hlist_deref(struct swevent_htable *swhash)
6918 return rcu_dereference_protected(swhash->swevent_hlist,
6919 lockdep_is_held(&swhash->hlist_mutex));
6922 static void swevent_hlist_release(struct swevent_htable *swhash)
6924 struct swevent_hlist *hlist = swevent_hlist_deref(swhash);
6929 RCU_INIT_POINTER(swhash->swevent_hlist, NULL);
6930 kfree_rcu(hlist, rcu_head);
6933 static void swevent_hlist_put_cpu(struct perf_event *event, int cpu)
6935 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
6937 mutex_lock(&swhash->hlist_mutex);
6939 if (!--swhash->hlist_refcount)
6940 swevent_hlist_release(swhash);
6942 mutex_unlock(&swhash->hlist_mutex);
6945 static void swevent_hlist_put(struct perf_event *event)
6949 for_each_possible_cpu(cpu)
6950 swevent_hlist_put_cpu(event, cpu);
6953 static int swevent_hlist_get_cpu(struct perf_event *event, int cpu)
6955 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
6958 mutex_lock(&swhash->hlist_mutex);
6959 if (!swevent_hlist_deref(swhash) && cpu_online(cpu)) {
6960 struct swevent_hlist *hlist;
6962 hlist = kzalloc(sizeof(*hlist), GFP_KERNEL);
6967 rcu_assign_pointer(swhash->swevent_hlist, hlist);
6969 swhash->hlist_refcount++;
6971 mutex_unlock(&swhash->hlist_mutex);
6976 static int swevent_hlist_get(struct perf_event *event)
6979 int cpu, failed_cpu;
6982 for_each_possible_cpu(cpu) {
6983 err = swevent_hlist_get_cpu(event, cpu);
6993 for_each_possible_cpu(cpu) {
6994 if (cpu == failed_cpu)
6996 swevent_hlist_put_cpu(event, cpu);
7003 struct static_key perf_swevent_enabled[PERF_COUNT_SW_MAX];
7005 static void sw_perf_event_destroy(struct perf_event *event)
7007 u64 event_id = event->attr.config;
7009 WARN_ON(event->parent);
7011 static_key_slow_dec(&perf_swevent_enabled[event_id]);
7012 swevent_hlist_put(event);
7015 static int perf_swevent_init(struct perf_event *event)
7017 u64 event_id = event->attr.config;
7019 if (event->attr.type != PERF_TYPE_SOFTWARE)
7023 * no branch sampling for software events
7025 if (has_branch_stack(event))
7029 case PERF_COUNT_SW_CPU_CLOCK:
7030 case PERF_COUNT_SW_TASK_CLOCK:
7037 if (event_id >= PERF_COUNT_SW_MAX)
7040 if (!event->parent) {
7043 err = swevent_hlist_get(event);
7047 static_key_slow_inc(&perf_swevent_enabled[event_id]);
7048 event->destroy = sw_perf_event_destroy;
7054 static struct pmu perf_swevent = {
7055 .task_ctx_nr = perf_sw_context,
7057 .capabilities = PERF_PMU_CAP_NO_NMI,
7059 .event_init = perf_swevent_init,
7060 .add = perf_swevent_add,
7061 .del = perf_swevent_del,
7062 .start = perf_swevent_start,
7063 .stop = perf_swevent_stop,
7064 .read = perf_swevent_read,
7067 #ifdef CONFIG_EVENT_TRACING
7069 static int perf_tp_filter_match(struct perf_event *event,
7070 struct perf_sample_data *data)
7072 void *record = data->raw->data;
7074 /* only top level events have filters set */
7076 event = event->parent;
7078 if (likely(!event->filter) || filter_match_preds(event->filter, record))
7083 static int perf_tp_event_match(struct perf_event *event,
7084 struct perf_sample_data *data,
7085 struct pt_regs *regs)
7087 if (event->hw.state & PERF_HES_STOPPED)
7090 * All tracepoints are from kernel-space.
7092 if (event->attr.exclude_kernel)
7095 if (!perf_tp_filter_match(event, data))
7101 void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
7102 struct pt_regs *regs, struct hlist_head *head, int rctx,
7103 struct task_struct *task)
7105 struct perf_sample_data data;
7106 struct perf_event *event;
7108 struct perf_raw_record raw = {
7113 perf_sample_data_init(&data, addr, 0);
7116 hlist_for_each_entry_rcu(event, head, hlist_entry) {
7117 if (perf_tp_event_match(event, &data, regs))
7118 perf_swevent_event(event, count, &data, regs);
7122 * If we got specified a target task, also iterate its context and
7123 * deliver this event there too.
7125 if (task && task != current) {
7126 struct perf_event_context *ctx;
7127 struct trace_entry *entry = record;
7130 ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]);
7134 list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
7135 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7137 if (event->attr.config != entry->type)
7139 if (perf_tp_event_match(event, &data, regs))
7140 perf_swevent_event(event, count, &data, regs);
7146 perf_swevent_put_recursion_context(rctx);
7148 EXPORT_SYMBOL_GPL(perf_tp_event);
7150 static void tp_perf_event_destroy(struct perf_event *event)
7152 perf_trace_destroy(event);
7155 static int perf_tp_event_init(struct perf_event *event)
7159 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7163 * no branch sampling for tracepoint events
7165 if (has_branch_stack(event))
7168 err = perf_trace_init(event);
7172 event->destroy = tp_perf_event_destroy;
7177 static struct pmu perf_tracepoint = {
7178 .task_ctx_nr = perf_sw_context,
7180 .event_init = perf_tp_event_init,
7181 .add = perf_trace_add,
7182 .del = perf_trace_del,
7183 .start = perf_swevent_start,
7184 .stop = perf_swevent_stop,
7185 .read = perf_swevent_read,
7188 static inline void perf_tp_register(void)
7190 perf_pmu_register(&perf_tracepoint, "tracepoint", PERF_TYPE_TRACEPOINT);
7193 static int perf_event_set_filter(struct perf_event *event, void __user *arg)
7198 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7201 filter_str = strndup_user(arg, PAGE_SIZE);
7202 if (IS_ERR(filter_str))
7203 return PTR_ERR(filter_str);
7205 ret = ftrace_profile_set_filter(event, event->attr.config, filter_str);
7211 static void perf_event_free_filter(struct perf_event *event)
7213 ftrace_profile_free_filter(event);
7216 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
7218 struct bpf_prog *prog;
7220 if (event->attr.type != PERF_TYPE_TRACEPOINT)
7223 if (event->tp_event->prog)
7226 if (!(event->tp_event->flags & TRACE_EVENT_FL_UKPROBE))
7227 /* bpf programs can only be attached to u/kprobes */
7230 prog = bpf_prog_get(prog_fd);
7232 return PTR_ERR(prog);
7234 if (prog->type != BPF_PROG_TYPE_KPROBE) {
7235 /* valid fd, but invalid bpf program type */
7240 event->tp_event->prog = prog;
7245 static void perf_event_free_bpf_prog(struct perf_event *event)
7247 struct bpf_prog *prog;
7249 if (!event->tp_event)
7252 prog = event->tp_event->prog;
7254 event->tp_event->prog = NULL;
7255 bpf_prog_put_rcu(prog);
7261 static inline void perf_tp_register(void)
7265 static int perf_event_set_filter(struct perf_event *event, void __user *arg)
7270 static void perf_event_free_filter(struct perf_event *event)
7274 static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
7279 static void perf_event_free_bpf_prog(struct perf_event *event)
7282 #endif /* CONFIG_EVENT_TRACING */
7284 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7285 void perf_bp_event(struct perf_event *bp, void *data)
7287 struct perf_sample_data sample;
7288 struct pt_regs *regs = data;
7290 perf_sample_data_init(&sample, bp->attr.bp_addr, 0);
7292 if (!bp->hw.state && !perf_exclude_event(bp, regs))
7293 perf_swevent_event(bp, 1, &sample, regs);
7297 static int perf_event_drv_configs(struct perf_event *event,
7300 if (!event->pmu->get_drv_configs)
7303 return event->pmu->get_drv_configs(event, arg);
7307 * hrtimer based swevent callback
7310 static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
7312 enum hrtimer_restart ret = HRTIMER_RESTART;
7313 struct perf_sample_data data;
7314 struct pt_regs *regs;
7315 struct perf_event *event;
7318 event = container_of(hrtimer, struct perf_event, hw.hrtimer);
7320 if (event->state != PERF_EVENT_STATE_ACTIVE)
7321 return HRTIMER_NORESTART;
7323 event->pmu->read(event);
7325 perf_sample_data_init(&data, 0, event->hw.last_period);
7326 regs = get_irq_regs();
7328 if (regs && !perf_exclude_event(event, regs)) {
7329 if (!(event->attr.exclude_idle && is_idle_task(current)))
7330 if (__perf_event_overflow(event, 1, &data, regs))
7331 ret = HRTIMER_NORESTART;
7334 period = max_t(u64, 10000, event->hw.sample_period);
7335 hrtimer_forward_now(hrtimer, ns_to_ktime(period));
7340 static void perf_swevent_start_hrtimer(struct perf_event *event)
7342 struct hw_perf_event *hwc = &event->hw;
7345 if (!is_sampling_event(event))
7348 period = local64_read(&hwc->period_left);
7353 local64_set(&hwc->period_left, 0);
7355 period = max_t(u64, 10000, hwc->sample_period);
7357 hrtimer_start(&hwc->hrtimer, ns_to_ktime(period),
7358 HRTIMER_MODE_REL_PINNED);
7361 static void perf_swevent_cancel_hrtimer(struct perf_event *event)
7363 struct hw_perf_event *hwc = &event->hw;
7365 if (is_sampling_event(event)) {
7366 ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
7367 local64_set(&hwc->period_left, ktime_to_ns(remaining));
7369 hrtimer_cancel(&hwc->hrtimer);
7373 static void perf_swevent_init_hrtimer(struct perf_event *event)
7375 struct hw_perf_event *hwc = &event->hw;
7377 if (!is_sampling_event(event))
7380 hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
7381 hwc->hrtimer.function = perf_swevent_hrtimer;
7384 * Since hrtimers have a fixed rate, we can do a static freq->period
7385 * mapping and avoid the whole period adjust feedback stuff.
7387 if (event->attr.freq) {
7388 long freq = event->attr.sample_freq;
7390 event->attr.sample_period = NSEC_PER_SEC / freq;
7391 hwc->sample_period = event->attr.sample_period;
7392 local64_set(&hwc->period_left, hwc->sample_period);
7393 hwc->last_period = hwc->sample_period;
7394 event->attr.freq = 0;
7399 * Software event: cpu wall time clock
7402 static void cpu_clock_event_update(struct perf_event *event)
7407 now = local_clock();
7408 prev = local64_xchg(&event->hw.prev_count, now);
7409 local64_add(now - prev, &event->count);
7412 static void cpu_clock_event_start(struct perf_event *event, int flags)
7414 local64_set(&event->hw.prev_count, local_clock());
7415 perf_swevent_start_hrtimer(event);
7418 static void cpu_clock_event_stop(struct perf_event *event, int flags)
7420 perf_swevent_cancel_hrtimer(event);
7421 cpu_clock_event_update(event);
7424 static int cpu_clock_event_add(struct perf_event *event, int flags)
7426 if (flags & PERF_EF_START)
7427 cpu_clock_event_start(event, flags);
7428 perf_event_update_userpage(event);
7433 static void cpu_clock_event_del(struct perf_event *event, int flags)
7435 cpu_clock_event_stop(event, flags);
7438 static void cpu_clock_event_read(struct perf_event *event)
7440 cpu_clock_event_update(event);
7443 static int cpu_clock_event_init(struct perf_event *event)
7445 if (event->attr.type != PERF_TYPE_SOFTWARE)
7448 if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
7452 * no branch sampling for software events
7454 if (has_branch_stack(event))
7457 perf_swevent_init_hrtimer(event);
7462 static struct pmu perf_cpu_clock = {
7463 .task_ctx_nr = perf_sw_context,
7465 .capabilities = PERF_PMU_CAP_NO_NMI,
7467 .event_init = cpu_clock_event_init,
7468 .add = cpu_clock_event_add,
7469 .del = cpu_clock_event_del,
7470 .start = cpu_clock_event_start,
7471 .stop = cpu_clock_event_stop,
7472 .read = cpu_clock_event_read,
7476 * Software event: task time clock
7479 static void task_clock_event_update(struct perf_event *event, u64 now)
7484 prev = local64_xchg(&event->hw.prev_count, now);
7486 local64_add(delta, &event->count);
7489 static void task_clock_event_start(struct perf_event *event, int flags)
7491 local64_set(&event->hw.prev_count, event->ctx->time);
7492 perf_swevent_start_hrtimer(event);
7495 static void task_clock_event_stop(struct perf_event *event, int flags)
7497 perf_swevent_cancel_hrtimer(event);
7498 task_clock_event_update(event, event->ctx->time);
7501 static int task_clock_event_add(struct perf_event *event, int flags)
7503 if (flags & PERF_EF_START)
7504 task_clock_event_start(event, flags);
7505 perf_event_update_userpage(event);
7510 static void task_clock_event_del(struct perf_event *event, int flags)
7512 task_clock_event_stop(event, PERF_EF_UPDATE);
7515 static void task_clock_event_read(struct perf_event *event)
7517 u64 now = perf_clock();
7518 u64 delta = now - event->ctx->timestamp;
7519 u64 time = event->ctx->time + delta;
7521 task_clock_event_update(event, time);
7524 static int task_clock_event_init(struct perf_event *event)
7526 if (event->attr.type != PERF_TYPE_SOFTWARE)
7529 if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
7533 * no branch sampling for software events
7535 if (has_branch_stack(event))
7538 perf_swevent_init_hrtimer(event);
7543 static struct pmu perf_task_clock = {
7544 .task_ctx_nr = perf_sw_context,
7546 .capabilities = PERF_PMU_CAP_NO_NMI,
7548 .event_init = task_clock_event_init,
7549 .add = task_clock_event_add,
7550 .del = task_clock_event_del,
7551 .start = task_clock_event_start,
7552 .stop = task_clock_event_stop,
7553 .read = task_clock_event_read,
7556 static void perf_pmu_nop_void(struct pmu *pmu)
7560 static void perf_pmu_nop_txn(struct pmu *pmu, unsigned int flags)
7564 static int perf_pmu_nop_int(struct pmu *pmu)
7569 static DEFINE_PER_CPU(unsigned int, nop_txn_flags);
7571 static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags)
7573 __this_cpu_write(nop_txn_flags, flags);
7575 if (flags & ~PERF_PMU_TXN_ADD)
7578 perf_pmu_disable(pmu);
7581 static int perf_pmu_commit_txn(struct pmu *pmu)
7583 unsigned int flags = __this_cpu_read(nop_txn_flags);
7585 __this_cpu_write(nop_txn_flags, 0);
7587 if (flags & ~PERF_PMU_TXN_ADD)
7590 perf_pmu_enable(pmu);
7594 static void perf_pmu_cancel_txn(struct pmu *pmu)
7596 unsigned int flags = __this_cpu_read(nop_txn_flags);
7598 __this_cpu_write(nop_txn_flags, 0);
7600 if (flags & ~PERF_PMU_TXN_ADD)
7603 perf_pmu_enable(pmu);
7606 static int perf_event_idx_default(struct perf_event *event)
7612 * Ensures all contexts with the same task_ctx_nr have the same
7613 * pmu_cpu_context too.
7615 static struct perf_cpu_context __percpu *find_pmu_context(int ctxn)
7622 list_for_each_entry(pmu, &pmus, entry) {
7623 if (pmu->task_ctx_nr == ctxn)
7624 return pmu->pmu_cpu_context;
7630 static void update_pmu_context(struct pmu *pmu, struct pmu *old_pmu)
7634 for_each_possible_cpu(cpu) {
7635 struct perf_cpu_context *cpuctx;
7637 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
7639 if (cpuctx->unique_pmu == old_pmu)
7640 cpuctx->unique_pmu = pmu;
7644 static void free_pmu_context(struct pmu *pmu)
7648 mutex_lock(&pmus_lock);
7650 * Like a real lame refcount.
7652 list_for_each_entry(i, &pmus, entry) {
7653 if (i->pmu_cpu_context == pmu->pmu_cpu_context) {
7654 update_pmu_context(i, pmu);
7659 free_percpu(pmu->pmu_cpu_context);
7661 mutex_unlock(&pmus_lock);
7663 static struct idr pmu_idr;
7666 type_show(struct device *dev, struct device_attribute *attr, char *page)
7668 struct pmu *pmu = dev_get_drvdata(dev);
7670 return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->type);
7672 static DEVICE_ATTR_RO(type);
7675 perf_event_mux_interval_ms_show(struct device *dev,
7676 struct device_attribute *attr,
7679 struct pmu *pmu = dev_get_drvdata(dev);
7681 return snprintf(page, PAGE_SIZE-1, "%d\n", pmu->hrtimer_interval_ms);
7684 static DEFINE_MUTEX(mux_interval_mutex);
7687 perf_event_mux_interval_ms_store(struct device *dev,
7688 struct device_attribute *attr,
7689 const char *buf, size_t count)
7691 struct pmu *pmu = dev_get_drvdata(dev);
7692 int timer, cpu, ret;
7694 ret = kstrtoint(buf, 0, &timer);
7701 /* same value, noting to do */
7702 if (timer == pmu->hrtimer_interval_ms)
7705 mutex_lock(&mux_interval_mutex);
7706 pmu->hrtimer_interval_ms = timer;
7708 /* update all cpuctx for this PMU */
7710 for_each_online_cpu(cpu) {
7711 struct perf_cpu_context *cpuctx;
7712 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
7713 cpuctx->hrtimer_interval = ns_to_ktime(NSEC_PER_MSEC * timer);
7715 cpu_function_call(cpu,
7716 (remote_function_f)perf_mux_hrtimer_restart, cpuctx);
7719 mutex_unlock(&mux_interval_mutex);
7723 static DEVICE_ATTR_RW(perf_event_mux_interval_ms);
7725 static struct attribute *pmu_dev_attrs[] = {
7726 &dev_attr_type.attr,
7727 &dev_attr_perf_event_mux_interval_ms.attr,
7730 ATTRIBUTE_GROUPS(pmu_dev);
7732 static int pmu_bus_running;
7733 static struct bus_type pmu_bus = {
7734 .name = "event_source",
7735 .dev_groups = pmu_dev_groups,
7738 static void pmu_dev_release(struct device *dev)
7743 static int pmu_dev_alloc(struct pmu *pmu)
7747 pmu->dev = kzalloc(sizeof(struct device), GFP_KERNEL);
7751 pmu->dev->groups = pmu->attr_groups;
7752 device_initialize(pmu->dev);
7753 ret = dev_set_name(pmu->dev, "%s", pmu->name);
7757 dev_set_drvdata(pmu->dev, pmu);
7758 pmu->dev->bus = &pmu_bus;
7759 pmu->dev->release = pmu_dev_release;
7760 ret = device_add(pmu->dev);
7768 put_device(pmu->dev);
7772 static struct lock_class_key cpuctx_mutex;
7773 static struct lock_class_key cpuctx_lock;
7775 int perf_pmu_register(struct pmu *pmu, const char *name, int type)
7779 mutex_lock(&pmus_lock);
7781 pmu->pmu_disable_count = alloc_percpu(int);
7782 if (!pmu->pmu_disable_count)
7791 type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL);
7799 if (pmu_bus_running) {
7800 ret = pmu_dev_alloc(pmu);
7806 pmu->pmu_cpu_context = find_pmu_context(pmu->task_ctx_nr);
7807 if (pmu->pmu_cpu_context)
7808 goto got_cpu_context;
7811 pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context);
7812 if (!pmu->pmu_cpu_context)
7815 for_each_possible_cpu(cpu) {
7816 struct perf_cpu_context *cpuctx;
7818 cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
7819 __perf_event_init_context(&cpuctx->ctx);
7820 lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
7821 lockdep_set_class(&cpuctx->ctx.lock, &cpuctx_lock);
7822 cpuctx->ctx.pmu = pmu;
7824 __perf_mux_hrtimer_init(cpuctx, cpu);
7826 cpuctx->unique_pmu = pmu;
7830 if (!pmu->start_txn) {
7831 if (pmu->pmu_enable) {
7833 * If we have pmu_enable/pmu_disable calls, install
7834 * transaction stubs that use that to try and batch
7835 * hardware accesses.
7837 pmu->start_txn = perf_pmu_start_txn;
7838 pmu->commit_txn = perf_pmu_commit_txn;
7839 pmu->cancel_txn = perf_pmu_cancel_txn;
7841 pmu->start_txn = perf_pmu_nop_txn;
7842 pmu->commit_txn = perf_pmu_nop_int;
7843 pmu->cancel_txn = perf_pmu_nop_void;
7847 if (!pmu->pmu_enable) {
7848 pmu->pmu_enable = perf_pmu_nop_void;
7849 pmu->pmu_disable = perf_pmu_nop_void;
7852 if (!pmu->event_idx)
7853 pmu->event_idx = perf_event_idx_default;
7855 list_add_rcu(&pmu->entry, &pmus);
7856 atomic_set(&pmu->exclusive_cnt, 0);
7859 mutex_unlock(&pmus_lock);
7864 device_del(pmu->dev);
7865 put_device(pmu->dev);
7868 if (pmu->type >= PERF_TYPE_MAX)
7869 idr_remove(&pmu_idr, pmu->type);
7872 free_percpu(pmu->pmu_disable_count);
7875 EXPORT_SYMBOL_GPL(perf_pmu_register);
7877 void perf_pmu_unregister(struct pmu *pmu)
7879 mutex_lock(&pmus_lock);
7880 list_del_rcu(&pmu->entry);
7881 mutex_unlock(&pmus_lock);
7884 * We dereference the pmu list under both SRCU and regular RCU, so
7885 * synchronize against both of those.
7887 synchronize_srcu(&pmus_srcu);
7890 free_percpu(pmu->pmu_disable_count);
7891 if (pmu->type >= PERF_TYPE_MAX)
7892 idr_remove(&pmu_idr, pmu->type);
7893 device_del(pmu->dev);
7894 put_device(pmu->dev);
7895 free_pmu_context(pmu);
7897 EXPORT_SYMBOL_GPL(perf_pmu_unregister);
7899 static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)
7901 struct perf_event_context *ctx = NULL;
7904 if (!try_module_get(pmu->module))
7907 if (event->group_leader != event) {
7909 * This ctx->mutex can nest when we're called through
7910 * inheritance. See the perf_event_ctx_lock_nested() comment.
7912 ctx = perf_event_ctx_lock_nested(event->group_leader,
7913 SINGLE_DEPTH_NESTING);
7918 ret = pmu->event_init(event);
7921 perf_event_ctx_unlock(event->group_leader, ctx);
7924 module_put(pmu->module);
7929 static struct pmu *perf_init_event(struct perf_event *event)
7931 struct pmu *pmu = NULL;
7935 idx = srcu_read_lock(&pmus_srcu);
7938 pmu = idr_find(&pmu_idr, event->attr.type);
7941 ret = perf_try_init_event(pmu, event);
7947 list_for_each_entry_rcu(pmu, &pmus, entry) {
7948 ret = perf_try_init_event(pmu, event);
7952 if (ret != -ENOENT) {
7957 pmu = ERR_PTR(-ENOENT);
7959 srcu_read_unlock(&pmus_srcu, idx);
7964 static void account_event_cpu(struct perf_event *event, int cpu)
7969 if (is_cgroup_event(event))
7970 atomic_inc(&per_cpu(perf_cgroup_events, cpu));
7973 static void account_event(struct perf_event *event)
7978 if (event->attach_state & PERF_ATTACH_TASK)
7979 static_key_slow_inc(&perf_sched_events.key);
7980 if (event->attr.mmap || event->attr.mmap_data)
7981 atomic_inc(&nr_mmap_events);
7982 if (event->attr.comm)
7983 atomic_inc(&nr_comm_events);
7984 if (event->attr.task)
7985 atomic_inc(&nr_task_events);
7986 if (event->attr.freq) {
7987 if (atomic_inc_return(&nr_freq_events) == 1)
7988 tick_nohz_full_kick_all();
7990 if (event->attr.context_switch) {
7991 atomic_inc(&nr_switch_events);
7992 static_key_slow_inc(&perf_sched_events.key);
7994 if (has_branch_stack(event))
7995 static_key_slow_inc(&perf_sched_events.key);
7996 if (is_cgroup_event(event))
7997 static_key_slow_inc(&perf_sched_events.key);
7999 account_event_cpu(event, event->cpu);
8003 * Allocate and initialize a event structure
8005 static struct perf_event *
8006 perf_event_alloc(struct perf_event_attr *attr, int cpu,
8007 struct task_struct *task,
8008 struct perf_event *group_leader,
8009 struct perf_event *parent_event,
8010 perf_overflow_handler_t overflow_handler,
8011 void *context, int cgroup_fd)
8014 struct perf_event *event;
8015 struct hw_perf_event *hwc;
8018 if ((unsigned)cpu >= nr_cpu_ids) {
8019 if (!task || cpu != -1)
8020 return ERR_PTR(-EINVAL);
8023 event = kzalloc(sizeof(*event), GFP_KERNEL);
8025 return ERR_PTR(-ENOMEM);
8028 * Single events are their own group leaders, with an
8029 * empty sibling list:
8032 group_leader = event;
8034 mutex_init(&event->child_mutex);
8035 INIT_LIST_HEAD(&event->child_list);
8037 INIT_LIST_HEAD(&event->group_entry);
8038 INIT_LIST_HEAD(&event->event_entry);
8039 INIT_LIST_HEAD(&event->sibling_list);
8040 INIT_LIST_HEAD(&event->rb_entry);
8041 INIT_LIST_HEAD(&event->active_entry);
8042 INIT_LIST_HEAD(&event->drv_configs);
8043 INIT_HLIST_NODE(&event->hlist_entry);
8046 init_waitqueue_head(&event->waitq);
8047 init_irq_work(&event->pending, perf_pending_event);
8049 mutex_init(&event->mmap_mutex);
8051 atomic_long_set(&event->refcount, 1);
8053 event->attr = *attr;
8054 event->group_leader = group_leader;
8058 event->parent = parent_event;
8060 event->ns = get_pid_ns(task_active_pid_ns(current));
8061 event->id = atomic64_inc_return(&perf_event_id);
8063 event->state = PERF_EVENT_STATE_INACTIVE;
8066 event->attach_state = PERF_ATTACH_TASK;
8068 * XXX pmu::event_init needs to know what task to account to
8069 * and we cannot use the ctx information because we need the
8070 * pmu before we get a ctx.
8072 event->hw.target = task;
8075 event->clock = &local_clock;
8077 event->clock = parent_event->clock;
8079 if (!overflow_handler && parent_event) {
8080 overflow_handler = parent_event->overflow_handler;
8081 context = parent_event->overflow_handler_context;
8084 event->overflow_handler = overflow_handler;
8085 event->overflow_handler_context = context;
8087 perf_event__state_init(event);
8092 hwc->sample_period = attr->sample_period;
8093 if (attr->freq && attr->sample_freq)
8094 hwc->sample_period = 1;
8095 hwc->last_period = hwc->sample_period;
8097 local64_set(&hwc->period_left, hwc->sample_period);
8100 * we currently do not support PERF_FORMAT_GROUP on inherited events
8102 if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
8105 if (!has_branch_stack(event))
8106 event->attr.branch_sample_type = 0;
8108 if (cgroup_fd != -1) {
8109 err = perf_cgroup_connect(cgroup_fd, event, attr, group_leader);
8114 pmu = perf_init_event(event);
8117 else if (IS_ERR(pmu)) {
8122 err = exclusive_event_init(event);
8126 if (!event->parent) {
8127 if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
8128 err = get_callchain_buffers();
8134 /* symmetric to unaccount_event() in _free_event() */
8135 account_event(event);
8140 exclusive_event_destroy(event);
8144 event->destroy(event);
8145 module_put(pmu->module);
8147 if (is_cgroup_event(event))
8148 perf_detach_cgroup(event);
8150 put_pid_ns(event->ns);
8153 return ERR_PTR(err);
8156 static int perf_copy_attr(struct perf_event_attr __user *uattr,
8157 struct perf_event_attr *attr)
8162 if (!access_ok(VERIFY_WRITE, uattr, PERF_ATTR_SIZE_VER0))
8166 * zero the full structure, so that a short copy will be nice.
8168 memset(attr, 0, sizeof(*attr));
8170 ret = get_user(size, &uattr->size);
8174 if (size > PAGE_SIZE) /* silly large */
8177 if (!size) /* abi compat */
8178 size = PERF_ATTR_SIZE_VER0;
8180 if (size < PERF_ATTR_SIZE_VER0)
8184 * If we're handed a bigger struct than we know of,
8185 * ensure all the unknown bits are 0 - i.e. new
8186 * user-space does not rely on any kernel feature
8187 * extensions we dont know about yet.
8189 if (size > sizeof(*attr)) {
8190 unsigned char __user *addr;
8191 unsigned char __user *end;
8194 addr = (void __user *)uattr + sizeof(*attr);
8195 end = (void __user *)uattr + size;
8197 for (; addr < end; addr++) {
8198 ret = get_user(val, addr);
8204 size = sizeof(*attr);
8207 ret = copy_from_user(attr, uattr, size);
8211 if (attr->__reserved_1)
8214 if (attr->sample_type & ~(PERF_SAMPLE_MAX-1))
8217 if (attr->read_format & ~(PERF_FORMAT_MAX-1))
8220 if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
8221 u64 mask = attr->branch_sample_type;
8223 /* only using defined bits */
8224 if (mask & ~(PERF_SAMPLE_BRANCH_MAX-1))
8227 /* at least one branch bit must be set */
8228 if (!(mask & ~PERF_SAMPLE_BRANCH_PLM_ALL))
8231 /* propagate priv level, when not set for branch */
8232 if (!(mask & PERF_SAMPLE_BRANCH_PLM_ALL)) {
8234 /* exclude_kernel checked on syscall entry */
8235 if (!attr->exclude_kernel)
8236 mask |= PERF_SAMPLE_BRANCH_KERNEL;
8238 if (!attr->exclude_user)
8239 mask |= PERF_SAMPLE_BRANCH_USER;
8241 if (!attr->exclude_hv)
8242 mask |= PERF_SAMPLE_BRANCH_HV;
8244 * adjust user setting (for HW filter setup)
8246 attr->branch_sample_type = mask;
8248 /* privileged levels capture (kernel, hv): check permissions */
8249 if ((mask & PERF_SAMPLE_BRANCH_PERM_PLM)
8250 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
8254 if (attr->sample_type & PERF_SAMPLE_REGS_USER) {
8255 ret = perf_reg_validate(attr->sample_regs_user);
8260 if (attr->sample_type & PERF_SAMPLE_STACK_USER) {
8261 if (!arch_perf_have_user_stack_dump())
8265 * We have __u32 type for the size, but so far
8266 * we can only use __u16 as maximum due to the
8267 * __u16 sample size limit.
8269 if (attr->sample_stack_user >= USHRT_MAX)
8271 else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
8275 if (attr->sample_type & PERF_SAMPLE_REGS_INTR)
8276 ret = perf_reg_validate(attr->sample_regs_intr);
8281 put_user(sizeof(*attr), &uattr->size);
8287 perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
8289 struct ring_buffer *rb = NULL;
8295 /* don't allow circular references */
8296 if (event == output_event)
8300 * Don't allow cross-cpu buffers
8302 if (output_event->cpu != event->cpu)
8306 * If its not a per-cpu rb, it must be the same task.
8308 if (output_event->cpu == -1 && output_event->ctx != event->ctx)
8312 * Mixing clocks in the same buffer is trouble you don't need.
8314 if (output_event->clock != event->clock)
8318 * If both events generate aux data, they must be on the same PMU
8320 if (has_aux(event) && has_aux(output_event) &&
8321 event->pmu != output_event->pmu)
8325 mutex_lock(&event->mmap_mutex);
8326 /* Can't redirect output if we've got an active mmap() */
8327 if (atomic_read(&event->mmap_count))
8331 /* get the rb we want to redirect to */
8332 rb = ring_buffer_get(output_event);
8337 ring_buffer_attach(event, rb);
8341 mutex_unlock(&event->mmap_mutex);
8347 static void mutex_lock_double(struct mutex *a, struct mutex *b)
8353 mutex_lock_nested(b, SINGLE_DEPTH_NESTING);
8356 static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
8358 bool nmi_safe = false;
8361 case CLOCK_MONOTONIC:
8362 event->clock = &ktime_get_mono_fast_ns;
8366 case CLOCK_MONOTONIC_RAW:
8367 event->clock = &ktime_get_raw_fast_ns;
8371 case CLOCK_REALTIME:
8372 event->clock = &ktime_get_real_ns;
8375 case CLOCK_BOOTTIME:
8376 event->clock = &ktime_get_boot_ns;
8380 event->clock = &ktime_get_tai_ns;
8387 if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI))
8394 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8396 * @attr_uptr: event_id type attributes for monitoring/sampling
8399 * @group_fd: group leader event fd
8401 SYSCALL_DEFINE5(perf_event_open,
8402 struct perf_event_attr __user *, attr_uptr,
8403 pid_t, pid, int, cpu, int, group_fd, unsigned long, flags)
8405 struct perf_event *group_leader = NULL, *output_event = NULL;
8406 struct perf_event *event, *sibling;
8407 struct perf_event_attr attr;
8408 struct perf_event_context *ctx, *uninitialized_var(gctx);
8409 struct file *event_file = NULL;
8410 struct fd group = {NULL, 0};
8411 struct task_struct *task = NULL;
8416 int f_flags = O_RDWR;
8419 /* for future expandability... */
8420 if (flags & ~PERF_FLAG_ALL)
8423 if (perf_paranoid_any() && !capable(CAP_SYS_ADMIN))
8426 err = perf_copy_attr(attr_uptr, &attr);
8430 if (!attr.exclude_kernel) {
8431 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
8436 if (attr.sample_freq > sysctl_perf_event_sample_rate)
8439 if (attr.sample_period & (1ULL << 63))
8444 * In cgroup mode, the pid argument is used to pass the fd
8445 * opened to the cgroup directory in cgroupfs. The cpu argument
8446 * designates the cpu on which to monitor threads from that
8449 if ((flags & PERF_FLAG_PID_CGROUP) && (pid == -1 || cpu == -1))
8452 if (flags & PERF_FLAG_FD_CLOEXEC)
8453 f_flags |= O_CLOEXEC;
8455 event_fd = get_unused_fd_flags(f_flags);
8459 if (group_fd != -1) {
8460 err = perf_fget_light(group_fd, &group);
8463 group_leader = group.file->private_data;
8464 if (flags & PERF_FLAG_FD_OUTPUT)
8465 output_event = group_leader;
8466 if (flags & PERF_FLAG_FD_NO_GROUP)
8467 group_leader = NULL;
8470 if (pid != -1 && !(flags & PERF_FLAG_PID_CGROUP)) {
8471 task = find_lively_task_by_vpid(pid);
8473 err = PTR_ERR(task);
8478 if (task && group_leader &&
8479 group_leader->attr.inherit != attr.inherit) {
8487 err = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
8492 * Reuse ptrace permission checks for now.
8494 * We must hold cred_guard_mutex across this and any potential
8495 * perf_install_in_context() call for this new event to
8496 * serialize against exec() altering our credentials (and the
8497 * perf_event_exit_task() that could imply).
8500 if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
8504 if (flags & PERF_FLAG_PID_CGROUP)
8507 event = perf_event_alloc(&attr, cpu, task, group_leader, NULL,
8508 NULL, NULL, cgroup_fd);
8509 if (IS_ERR(event)) {
8510 err = PTR_ERR(event);
8514 if (is_sampling_event(event)) {
8515 if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
8522 * Special case software events and allow them to be part of
8523 * any hardware group.
8527 if (attr.use_clockid) {
8528 err = perf_event_set_clock(event, attr.clockid);
8534 (is_software_event(event) != is_software_event(group_leader))) {
8535 if (is_software_event(event)) {
8537 * If event and group_leader are not both a software
8538 * event, and event is, then group leader is not.
8540 * Allow the addition of software events to !software
8541 * groups, this is safe because software events never
8544 pmu = group_leader->pmu;
8545 } else if (is_software_event(group_leader) &&
8546 (group_leader->group_flags & PERF_GROUP_SOFTWARE)) {
8548 * In case the group is a pure software group, and we
8549 * try to add a hardware event, move the whole group to
8550 * the hardware context.
8557 * Get the target context (task or percpu):
8559 ctx = find_get_context(pmu, task, event);
8565 if ((pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) && group_leader) {
8571 * Look up the group leader (we will attach this event to it):
8577 * Do not allow a recursive hierarchy (this new sibling
8578 * becoming part of another group-sibling):
8580 if (group_leader->group_leader != group_leader)
8583 /* All events in a group should have the same clock */
8584 if (group_leader->clock != event->clock)
8588 * Do not allow to attach to a group in a different
8589 * task or CPU context:
8593 * Make sure we're both on the same task, or both
8596 if (group_leader->ctx->task != ctx->task)
8600 * Make sure we're both events for the same CPU;
8601 * grouping events for different CPUs is broken; since
8602 * you can never concurrently schedule them anyhow.
8604 if (group_leader->cpu != event->cpu)
8607 if (group_leader->ctx != ctx)
8612 * Only a group leader can be exclusive or pinned
8614 if (attr.exclusive || attr.pinned)
8619 err = perf_event_set_output(event, output_event);
8624 event_file = anon_inode_getfile("[perf_event]", &perf_fops, event,
8626 if (IS_ERR(event_file)) {
8627 err = PTR_ERR(event_file);
8633 gctx = group_leader->ctx;
8634 mutex_lock_double(&gctx->mutex, &ctx->mutex);
8636 mutex_lock(&ctx->mutex);
8639 if (!perf_event_validate_size(event)) {
8645 * Must be under the same ctx::mutex as perf_install_in_context(),
8646 * because we need to serialize with concurrent event creation.
8648 if (!exclusive_event_installable(event, ctx)) {
8649 /* exclusive and group stuff are assumed mutually exclusive */
8650 WARN_ON_ONCE(move_group);
8656 WARN_ON_ONCE(ctx->parent_ctx);
8659 * This is the point on no return; we cannot fail hereafter. This is
8660 * where we start modifying current state.
8665 * See perf_event_ctx_lock() for comments on the details
8666 * of swizzling perf_event::ctx.
8668 perf_remove_from_context(group_leader, false);
8670 list_for_each_entry(sibling, &group_leader->sibling_list,
8672 perf_remove_from_context(sibling, false);
8677 * Wait for everybody to stop referencing the events through
8678 * the old lists, before installing it on new lists.
8683 * Install the group siblings before the group leader.
8685 * Because a group leader will try and install the entire group
8686 * (through the sibling list, which is still in-tact), we can
8687 * end up with siblings installed in the wrong context.
8689 * By installing siblings first we NO-OP because they're not
8690 * reachable through the group lists.
8692 list_for_each_entry(sibling, &group_leader->sibling_list,
8694 perf_event__state_init(sibling);
8695 perf_install_in_context(ctx, sibling, sibling->cpu);
8700 * Removing from the context ends up with disabled
8701 * event. What we want here is event in the initial
8702 * startup state, ready to be add into new context.
8704 perf_event__state_init(group_leader);
8705 perf_install_in_context(ctx, group_leader, group_leader->cpu);
8709 * Now that all events are installed in @ctx, nothing
8710 * references @gctx anymore, so drop the last reference we have
8717 * Precalculate sample_data sizes; do while holding ctx::mutex such
8718 * that we're serialized against further additions and before
8719 * perf_install_in_context() which is the point the event is active and
8720 * can use these values.
8722 perf_event__header_size(event);
8723 perf_event__id_header_size(event);
8725 perf_install_in_context(ctx, event, event->cpu);
8726 perf_unpin_context(ctx);
8729 mutex_unlock(&gctx->mutex);
8730 mutex_unlock(&ctx->mutex);
8733 mutex_unlock(&task->signal->cred_guard_mutex);
8734 put_task_struct(task);
8739 event->owner = current;
8741 mutex_lock(¤t->perf_event_mutex);
8742 list_add_tail(&event->owner_entry, ¤t->perf_event_list);
8743 mutex_unlock(¤t->perf_event_mutex);
8746 * Drop the reference on the group_event after placing the
8747 * new event on the sibling_list. This ensures destruction
8748 * of the group leader will find the pointer to itself in
8749 * perf_group_detach().
8752 fd_install(event_fd, event_file);
8757 mutex_unlock(&gctx->mutex);
8758 mutex_unlock(&ctx->mutex);
8762 perf_unpin_context(ctx);
8766 * If event_file is set, the fput() above will have called ->release()
8767 * and that will take care of freeing the event.
8773 mutex_unlock(&task->signal->cred_guard_mutex);
8778 put_task_struct(task);
8782 put_unused_fd(event_fd);
8787 * perf_event_create_kernel_counter
8789 * @attr: attributes of the counter to create
8790 * @cpu: cpu in which the counter is bound
8791 * @task: task to profile (NULL for percpu)
8794 perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
8795 struct task_struct *task,
8796 perf_overflow_handler_t overflow_handler,
8799 struct perf_event_context *ctx;
8800 struct perf_event *event;
8804 * Get the target context (task or percpu):
8807 event = perf_event_alloc(attr, cpu, task, NULL, NULL,
8808 overflow_handler, context, -1);
8809 if (IS_ERR(event)) {
8810 err = PTR_ERR(event);
8814 /* Mark owner so we could distinguish it from user events. */
8815 event->owner = EVENT_OWNER_KERNEL;
8817 ctx = find_get_context(event->pmu, task, event);
8823 WARN_ON_ONCE(ctx->parent_ctx);
8824 mutex_lock(&ctx->mutex);
8825 if (!exclusive_event_installable(event, ctx)) {
8826 mutex_unlock(&ctx->mutex);
8827 perf_unpin_context(ctx);
8833 perf_install_in_context(ctx, event, cpu);
8834 perf_unpin_context(ctx);
8835 mutex_unlock(&ctx->mutex);
8842 return ERR_PTR(err);
8844 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter);
8846 void perf_pmu_migrate_context(struct pmu *pmu, int src_cpu, int dst_cpu)
8848 struct perf_event_context *src_ctx;
8849 struct perf_event_context *dst_ctx;
8850 struct perf_event *event, *tmp;
8853 src_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, src_cpu)->ctx;
8854 dst_ctx = &per_cpu_ptr(pmu->pmu_cpu_context, dst_cpu)->ctx;
8857 * See perf_event_ctx_lock() for comments on the details
8858 * of swizzling perf_event::ctx.
8860 mutex_lock_double(&src_ctx->mutex, &dst_ctx->mutex);
8861 list_for_each_entry_safe(event, tmp, &src_ctx->event_list,
8863 perf_remove_from_context(event, false);
8864 unaccount_event_cpu(event, src_cpu);
8866 list_add(&event->migrate_entry, &events);
8870 * Wait for the events to quiesce before re-instating them.
8875 * Re-instate events in 2 passes.
8877 * Skip over group leaders and only install siblings on this first
8878 * pass, siblings will not get enabled without a leader, however a
8879 * leader will enable its siblings, even if those are still on the old
8882 list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
8883 if (event->group_leader == event)
8886 list_del(&event->migrate_entry);
8887 if (event->state >= PERF_EVENT_STATE_OFF)
8888 event->state = PERF_EVENT_STATE_INACTIVE;
8889 account_event_cpu(event, dst_cpu);
8890 perf_install_in_context(dst_ctx, event, dst_cpu);
8895 * Once all the siblings are setup properly, install the group leaders
8898 list_for_each_entry_safe(event, tmp, &events, migrate_entry) {
8899 list_del(&event->migrate_entry);
8900 if (event->state >= PERF_EVENT_STATE_OFF)
8901 event->state = PERF_EVENT_STATE_INACTIVE;
8902 account_event_cpu(event, dst_cpu);
8903 perf_install_in_context(dst_ctx, event, dst_cpu);
8906 mutex_unlock(&dst_ctx->mutex);
8907 mutex_unlock(&src_ctx->mutex);
8909 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context);
8911 static void sync_child_event(struct perf_event *child_event,
8912 struct task_struct *child)
8914 struct perf_event *parent_event = child_event->parent;
8917 if (child_event->attr.inherit_stat)
8918 perf_event_read_event(child_event, child);
8920 child_val = perf_event_count(child_event);
8923 * Add back the child's count to the parent's count:
8925 atomic64_add(child_val, &parent_event->child_count);
8926 atomic64_add(child_event->total_time_enabled,
8927 &parent_event->child_total_time_enabled);
8928 atomic64_add(child_event->total_time_running,
8929 &parent_event->child_total_time_running);
8932 * Remove this event from the parent's list
8934 WARN_ON_ONCE(parent_event->ctx->parent_ctx);
8935 mutex_lock(&parent_event->child_mutex);
8936 list_del_init(&child_event->child_list);
8937 mutex_unlock(&parent_event->child_mutex);
8940 * Make sure user/parent get notified, that we just
8943 perf_event_wakeup(parent_event);
8946 * Release the parent event, if this was the last
8949 put_event(parent_event);
8953 __perf_event_exit_task(struct perf_event *child_event,
8954 struct perf_event_context *child_ctx,
8955 struct task_struct *child)
8958 * Do not destroy the 'original' grouping; because of the context
8959 * switch optimization the original events could've ended up in a
8960 * random child task.
8962 * If we were to destroy the original group, all group related
8963 * operations would cease to function properly after this random
8966 * Do destroy all inherited groups, we don't care about those
8967 * and being thorough is better.
8969 perf_remove_from_context(child_event, !!child_event->parent);
8972 * It can happen that the parent exits first, and has events
8973 * that are still around due to the child reference. These
8974 * events need to be zapped.
8976 if (child_event->parent) {
8977 sync_child_event(child_event, child);
8978 free_event(child_event);
8980 child_event->state = PERF_EVENT_STATE_EXIT;
8981 perf_event_wakeup(child_event);
8985 static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
8987 struct perf_event *child_event, *next;
8988 struct perf_event_context *child_ctx, *clone_ctx = NULL;
8989 unsigned long flags;
8991 if (likely(!child->perf_event_ctxp[ctxn]))
8994 local_irq_save(flags);
8996 * We can't reschedule here because interrupts are disabled,
8997 * and either child is current or it is a task that can't be
8998 * scheduled, so we are now safe from rescheduling changing
9001 child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]);
9004 * Take the context lock here so that if find_get_context is
9005 * reading child->perf_event_ctxp, we wait until it has
9006 * incremented the context's refcount before we do put_ctx below.
9008 raw_spin_lock(&child_ctx->lock);
9009 task_ctx_sched_out(child_ctx);
9010 child->perf_event_ctxp[ctxn] = NULL;
9013 * If this context is a clone; unclone it so it can't get
9014 * swapped to another process while we're removing all
9015 * the events from it.
9017 clone_ctx = unclone_ctx(child_ctx);
9018 update_context_time(child_ctx);
9019 raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
9025 * Report the task dead after unscheduling the events so that we
9026 * won't get any samples after PERF_RECORD_EXIT. We can however still
9027 * get a few PERF_RECORD_READ events.
9029 perf_event_task(child, child_ctx, 0);
9032 * We can recurse on the same lock type through:
9034 * __perf_event_exit_task()
9035 * sync_child_event()
9037 * mutex_lock(&ctx->mutex)
9039 * But since its the parent context it won't be the same instance.
9041 mutex_lock(&child_ctx->mutex);
9043 list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry)
9044 __perf_event_exit_task(child_event, child_ctx, child);
9046 mutex_unlock(&child_ctx->mutex);
9052 * When a child task exits, feed back event values to parent events.
9054 * Can be called with cred_guard_mutex held when called from
9055 * install_exec_creds().
9057 void perf_event_exit_task(struct task_struct *child)
9059 struct perf_event *event, *tmp;
9062 mutex_lock(&child->perf_event_mutex);
9063 list_for_each_entry_safe(event, tmp, &child->perf_event_list,
9065 list_del_init(&event->owner_entry);
9068 * Ensure the list deletion is visible before we clear
9069 * the owner, closes a race against perf_release() where
9070 * we need to serialize on the owner->perf_event_mutex.
9073 event->owner = NULL;
9075 mutex_unlock(&child->perf_event_mutex);
9077 for_each_task_context_nr(ctxn)
9078 perf_event_exit_task_context(child, ctxn);
9081 * The perf_event_exit_task_context calls perf_event_task
9082 * with child's task_ctx, which generates EXIT events for
9083 * child contexts and sets child->perf_event_ctxp[] to NULL.
9084 * At this point we need to send EXIT events to cpu contexts.
9086 perf_event_task(child, NULL, 0);
9089 static void perf_free_event(struct perf_event *event,
9090 struct perf_event_context *ctx)
9092 struct perf_event *parent = event->parent;
9094 if (WARN_ON_ONCE(!parent))
9097 mutex_lock(&parent->child_mutex);
9098 list_del_init(&event->child_list);
9099 mutex_unlock(&parent->child_mutex);
9103 raw_spin_lock_irq(&ctx->lock);
9104 perf_group_detach(event);
9105 list_del_event(event, ctx);
9106 raw_spin_unlock_irq(&ctx->lock);
9111 * Free an unexposed, unused context as created by inheritance by
9112 * perf_event_init_task below, used by fork() in case of fail.
9114 * Not all locks are strictly required, but take them anyway to be nice and
9115 * help out with the lockdep assertions.
9117 void perf_event_free_task(struct task_struct *task)
9119 struct perf_event_context *ctx;
9120 struct perf_event *event, *tmp;
9123 for_each_task_context_nr(ctxn) {
9124 ctx = task->perf_event_ctxp[ctxn];
9128 mutex_lock(&ctx->mutex);
9130 list_for_each_entry_safe(event, tmp, &ctx->pinned_groups,
9132 perf_free_event(event, ctx);
9134 list_for_each_entry_safe(event, tmp, &ctx->flexible_groups,
9136 perf_free_event(event, ctx);
9138 if (!list_empty(&ctx->pinned_groups) ||
9139 !list_empty(&ctx->flexible_groups))
9142 mutex_unlock(&ctx->mutex);
9148 void perf_event_delayed_put(struct task_struct *task)
9152 for_each_task_context_nr(ctxn)
9153 WARN_ON_ONCE(task->perf_event_ctxp[ctxn]);
9156 struct perf_event *perf_event_get(unsigned int fd)
9160 struct perf_event *event;
9162 err = perf_fget_light(fd, &f);
9164 return ERR_PTR(err);
9166 event = f.file->private_data;
9167 atomic_long_inc(&event->refcount);
9173 const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
9176 return ERR_PTR(-EINVAL);
9178 return &event->attr;
9182 * inherit a event from parent task to child task:
9184 static struct perf_event *
9185 inherit_event(struct perf_event *parent_event,
9186 struct task_struct *parent,
9187 struct perf_event_context *parent_ctx,
9188 struct task_struct *child,
9189 struct perf_event *group_leader,
9190 struct perf_event_context *child_ctx)
9192 enum perf_event_active_state parent_state = parent_event->state;
9193 struct perf_event *child_event;
9194 unsigned long flags;
9197 * Instead of creating recursive hierarchies of events,
9198 * we link inherited events back to the original parent,
9199 * which has a filp for sure, which we use as the reference
9202 if (parent_event->parent)
9203 parent_event = parent_event->parent;
9205 child_event = perf_event_alloc(&parent_event->attr,
9208 group_leader, parent_event,
9210 if (IS_ERR(child_event))
9213 if (is_orphaned_event(parent_event) ||
9214 !atomic_long_inc_not_zero(&parent_event->refcount)) {
9215 free_event(child_event);
9222 * Make the child state follow the state of the parent event,
9223 * not its attr.disabled bit. We hold the parent's mutex,
9224 * so we won't race with perf_event_{en, dis}able_family.
9226 if (parent_state >= PERF_EVENT_STATE_INACTIVE)
9227 child_event->state = PERF_EVENT_STATE_INACTIVE;
9229 child_event->state = PERF_EVENT_STATE_OFF;
9231 if (parent_event->attr.freq) {
9232 u64 sample_period = parent_event->hw.sample_period;
9233 struct hw_perf_event *hwc = &child_event->hw;
9235 hwc->sample_period = sample_period;
9236 hwc->last_period = sample_period;
9238 local64_set(&hwc->period_left, sample_period);
9241 child_event->ctx = child_ctx;
9242 child_event->overflow_handler = parent_event->overflow_handler;
9243 child_event->overflow_handler_context
9244 = parent_event->overflow_handler_context;
9247 * Precalculate sample_data sizes
9249 perf_event__header_size(child_event);
9250 perf_event__id_header_size(child_event);
9253 * Link it up in the child's context:
9255 raw_spin_lock_irqsave(&child_ctx->lock, flags);
9256 add_event_to_ctx(child_event, child_ctx);
9257 raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
9260 * Link this into the parent event's child list
9262 WARN_ON_ONCE(parent_event->ctx->parent_ctx);
9263 mutex_lock(&parent_event->child_mutex);
9264 list_add_tail(&child_event->child_list, &parent_event->child_list);
9265 mutex_unlock(&parent_event->child_mutex);
9270 static int inherit_group(struct perf_event *parent_event,
9271 struct task_struct *parent,
9272 struct perf_event_context *parent_ctx,
9273 struct task_struct *child,
9274 struct perf_event_context *child_ctx)
9276 struct perf_event *leader;
9277 struct perf_event *sub;
9278 struct perf_event *child_ctr;
9280 leader = inherit_event(parent_event, parent, parent_ctx,
9281 child, NULL, child_ctx);
9283 return PTR_ERR(leader);
9284 list_for_each_entry(sub, &parent_event->sibling_list, group_entry) {
9285 child_ctr = inherit_event(sub, parent, parent_ctx,
9286 child, leader, child_ctx);
9287 if (IS_ERR(child_ctr))
9288 return PTR_ERR(child_ctr);
9294 inherit_task_group(struct perf_event *event, struct task_struct *parent,
9295 struct perf_event_context *parent_ctx,
9296 struct task_struct *child, int ctxn,
9300 struct perf_event_context *child_ctx;
9302 if (!event->attr.inherit) {
9307 child_ctx = child->perf_event_ctxp[ctxn];
9310 * This is executed from the parent task context, so
9311 * inherit events that have been marked for cloning.
9312 * First allocate and initialize a context for the
9316 child_ctx = alloc_perf_context(parent_ctx->pmu, child);
9320 child->perf_event_ctxp[ctxn] = child_ctx;
9323 ret = inherit_group(event, parent, parent_ctx,
9333 * Initialize the perf_event context in task_struct
9335 static int perf_event_init_context(struct task_struct *child, int ctxn)
9337 struct perf_event_context *child_ctx, *parent_ctx;
9338 struct perf_event_context *cloned_ctx;
9339 struct perf_event *event;
9340 struct task_struct *parent = current;
9341 int inherited_all = 1;
9342 unsigned long flags;
9345 if (likely(!parent->perf_event_ctxp[ctxn]))
9349 * If the parent's context is a clone, pin it so it won't get
9352 parent_ctx = perf_pin_task_context(parent, ctxn);
9357 * No need to check if parent_ctx != NULL here; since we saw
9358 * it non-NULL earlier, the only reason for it to become NULL
9359 * is if we exit, and since we're currently in the middle of
9360 * a fork we can't be exiting at the same time.
9364 * Lock the parent list. No need to lock the child - not PID
9365 * hashed yet and not running, so nobody can access it.
9367 mutex_lock(&parent_ctx->mutex);
9370 * We dont have to disable NMIs - we are only looking at
9371 * the list, not manipulating it:
9373 list_for_each_entry(event, &parent_ctx->pinned_groups, group_entry) {
9374 ret = inherit_task_group(event, parent, parent_ctx,
9375 child, ctxn, &inherited_all);
9381 * We can't hold ctx->lock when iterating the ->flexible_group list due
9382 * to allocations, but we need to prevent rotation because
9383 * rotate_ctx() will change the list from interrupt context.
9385 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
9386 parent_ctx->rotate_disable = 1;
9387 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
9389 list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) {
9390 ret = inherit_task_group(event, parent, parent_ctx,
9391 child, ctxn, &inherited_all);
9396 raw_spin_lock_irqsave(&parent_ctx->lock, flags);
9397 parent_ctx->rotate_disable = 0;
9399 child_ctx = child->perf_event_ctxp[ctxn];
9401 if (child_ctx && inherited_all) {
9403 * Mark the child context as a clone of the parent
9404 * context, or of whatever the parent is a clone of.
9406 * Note that if the parent is a clone, the holding of
9407 * parent_ctx->lock avoids it from being uncloned.
9409 cloned_ctx = parent_ctx->parent_ctx;
9411 child_ctx->parent_ctx = cloned_ctx;
9412 child_ctx->parent_gen = parent_ctx->parent_gen;
9414 child_ctx->parent_ctx = parent_ctx;
9415 child_ctx->parent_gen = parent_ctx->generation;
9417 get_ctx(child_ctx->parent_ctx);
9420 raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
9421 mutex_unlock(&parent_ctx->mutex);
9423 perf_unpin_context(parent_ctx);
9424 put_ctx(parent_ctx);
9430 * Initialize the perf_event context in task_struct
9432 int perf_event_init_task(struct task_struct *child)
9436 memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
9437 mutex_init(&child->perf_event_mutex);
9438 INIT_LIST_HEAD(&child->perf_event_list);
9440 for_each_task_context_nr(ctxn) {
9441 ret = perf_event_init_context(child, ctxn);
9443 perf_event_free_task(child);
9451 static void __init perf_event_init_all_cpus(void)
9453 struct swevent_htable *swhash;
9456 for_each_possible_cpu(cpu) {
9457 swhash = &per_cpu(swevent_htable, cpu);
9458 mutex_init(&swhash->hlist_mutex);
9459 INIT_LIST_HEAD(&per_cpu(active_ctx_list, cpu));
9463 static void perf_event_init_cpu(int cpu)
9465 struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
9467 mutex_lock(&swhash->hlist_mutex);
9468 if (swhash->hlist_refcount > 0) {
9469 struct swevent_hlist *hlist;
9471 hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));
9473 rcu_assign_pointer(swhash->swevent_hlist, hlist);
9475 mutex_unlock(&swhash->hlist_mutex);
9478 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9479 static void __perf_event_exit_context(void *__info)
9481 struct remove_event re = { .detach_group = true };
9482 struct perf_event_context *ctx = __info;
9485 list_for_each_entry_rcu(re.event, &ctx->event_list, event_entry)
9486 __perf_remove_from_context(&re);
9490 static void perf_event_exit_cpu_context(int cpu)
9492 struct perf_event_context *ctx;
9496 idx = srcu_read_lock(&pmus_srcu);
9497 list_for_each_entry_rcu(pmu, &pmus, entry) {
9498 ctx = &per_cpu_ptr(pmu->pmu_cpu_context, cpu)->ctx;
9500 mutex_lock(&ctx->mutex);
9501 smp_call_function_single(cpu, __perf_event_exit_context, ctx, 1);
9502 mutex_unlock(&ctx->mutex);
9504 srcu_read_unlock(&pmus_srcu, idx);
9507 static void perf_event_exit_cpu(int cpu)
9509 perf_event_exit_cpu_context(cpu);
9512 static inline void perf_event_exit_cpu(int cpu) { }
9516 perf_reboot(struct notifier_block *notifier, unsigned long val, void *v)
9520 for_each_online_cpu(cpu)
9521 perf_event_exit_cpu(cpu);
9527 * Run the perf reboot notifier at the very last possible moment so that
9528 * the generic watchdog code runs as long as possible.
9530 static struct notifier_block perf_reboot_notifier = {
9531 .notifier_call = perf_reboot,
9532 .priority = INT_MIN,
9536 perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
9538 unsigned int cpu = (long)hcpu;
9540 switch (action & ~CPU_TASKS_FROZEN) {
9542 case CPU_UP_PREPARE:
9543 case CPU_DOWN_FAILED:
9544 perf_event_init_cpu(cpu);
9547 case CPU_UP_CANCELED:
9548 case CPU_DOWN_PREPARE:
9549 perf_event_exit_cpu(cpu);
9558 void __init perf_event_init(void)
9564 perf_event_init_all_cpus();
9565 init_srcu_struct(&pmus_srcu);
9566 perf_pmu_register(&perf_swevent, "software", PERF_TYPE_SOFTWARE);
9567 perf_pmu_register(&perf_cpu_clock, NULL, -1);
9568 perf_pmu_register(&perf_task_clock, NULL, -1);
9570 perf_cpu_notifier(perf_cpu_notify);
9571 register_reboot_notifier(&perf_reboot_notifier);
9573 ret = init_hw_breakpoint();
9574 WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
9576 /* do not patch jump label more than once per second */
9577 jump_label_rate_limit(&perf_sched_events, HZ);
9580 * Build time assertion that we keep the data_head at the intended
9581 * location. IOW, validation we got the __reserved[] size right.
9583 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page, data_head))
9587 ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr,
9590 struct perf_pmu_events_attr *pmu_attr =
9591 container_of(attr, struct perf_pmu_events_attr, attr);
9593 if (pmu_attr->event_str)
9594 return sprintf(page, "%s\n", pmu_attr->event_str);
9599 static int __init perf_event_sysfs_init(void)
9604 mutex_lock(&pmus_lock);
9606 ret = bus_register(&pmu_bus);
9610 list_for_each_entry(pmu, &pmus, entry) {
9611 if (!pmu->name || pmu->type < 0)
9614 ret = pmu_dev_alloc(pmu);
9615 WARN(ret, "Failed to register pmu: %s, reason %d\n", pmu->name, ret);
9617 pmu_bus_running = 1;
9621 mutex_unlock(&pmus_lock);
9625 device_initcall(perf_event_sysfs_init);
9627 #ifdef CONFIG_CGROUP_PERF
9628 static struct cgroup_subsys_state *
9629 perf_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
9631 struct perf_cgroup *jc;
9633 jc = kzalloc(sizeof(*jc), GFP_KERNEL);
9635 return ERR_PTR(-ENOMEM);
9637 jc->info = alloc_percpu(struct perf_cgroup_info);
9640 return ERR_PTR(-ENOMEM);
9646 static void perf_cgroup_css_free(struct cgroup_subsys_state *css)
9648 struct perf_cgroup *jc = container_of(css, struct perf_cgroup, css);
9650 free_percpu(jc->info);
9654 static int __perf_cgroup_move(void *info)
9656 struct task_struct *task = info;
9658 perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN);
9663 static void perf_cgroup_attach(struct cgroup_taskset *tset)
9665 struct task_struct *task;
9666 struct cgroup_subsys_state *css;
9668 cgroup_taskset_for_each(task, css, tset)
9669 task_function_call(task, __perf_cgroup_move, task);
9672 struct cgroup_subsys perf_event_cgrp_subsys = {
9673 .css_alloc = perf_cgroup_css_alloc,
9674 .css_free = perf_cgroup_css_free,
9675 .attach = perf_cgroup_attach,
9677 #endif /* CONFIG_CGROUP_PERF */