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 static inline struct perf_cpu_context
*
130 __get_cpu_context(struct perf_event_context
*ctx
)
132 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
135 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
136 struct perf_event_context
*ctx
)
138 raw_spin_lock(&cpuctx
->ctx
.lock
);
140 raw_spin_lock(&ctx
->lock
);
143 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
144 struct perf_event_context
*ctx
)
147 raw_spin_unlock(&ctx
->lock
);
148 raw_spin_unlock(&cpuctx
->ctx
.lock
);
152 * On task ctx scheduling...
154 * When !ctx->nr_events a task context will not be scheduled. This means
155 * we can disable the scheduler hooks (for performance) without leaving
156 * pending task ctx state.
158 * This however results in two special cases:
160 * - removing the last event from a task ctx; this is relatively straight
161 * forward and is done in __perf_remove_from_context.
163 * - adding the first event to a task ctx; this is tricky because we cannot
164 * rely on ctx->is_active and therefore cannot use event_function_call().
165 * See perf_install_in_context().
167 * This is because we need a ctx->lock serialized variable (ctx->is_active)
168 * to reliably determine if a particular task/context is scheduled in. The
169 * task_curr() use in task_function_call() is racy in that a remote context
170 * switch is not a single atomic operation.
172 * As is, the situation is 'safe' because we set rq->curr before we do the
173 * actual context switch. This means that task_curr() will fail early, but
174 * we'll continue spinning on ctx->is_active until we've passed
175 * perf_event_task_sched_out().
177 * Without this ctx->lock serialized variable we could have race where we find
178 * the task (and hence the context) would not be active while in fact they are.
180 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
183 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
184 struct perf_event_context
*, void *);
186 struct event_function_struct
{
187 struct perf_event
*event
;
192 static int event_function(void *info
)
194 struct event_function_struct
*efs
= info
;
195 struct perf_event
*event
= efs
->event
;
196 struct perf_event_context
*ctx
= event
->ctx
;
197 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
198 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
200 WARN_ON_ONCE(!irqs_disabled());
203 * Since we do the IPI call without holding ctx->lock things can have
204 * changed, double check we hit the task we set out to hit.
206 * If ctx->task == current, we know things must remain valid because
207 * we have IRQs disabled so we cannot schedule.
210 if (ctx
->task
!= current
)
213 WARN_ON_ONCE(task_ctx
!= ctx
);
215 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
218 perf_ctx_lock(cpuctx
, task_ctx
);
220 * Now that we hold locks, double check state. Paranoia pays.
223 WARN_ON_ONCE(task_ctx
->task
!= current
);
225 * We only use event_function_call() on established contexts,
226 * and event_function() is only ever called when active (or
227 * rather, we'll have bailed in task_function_call() or the
228 * above ctx->task != current test), therefore we must have
229 * ctx->is_active here.
231 WARN_ON_ONCE(!ctx
->is_active
);
233 * And since we have ctx->is_active, cpuctx->task_ctx must
236 WARN_ON_ONCE(cpuctx
->task_ctx
!= task_ctx
);
238 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
239 perf_ctx_unlock(cpuctx
, task_ctx
);
244 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
246 struct event_function_struct efs
= {
252 int ret
= event_function(&efs
);
256 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
258 struct perf_event_context
*ctx
= event
->ctx
;
259 struct task_struct
*task
= ctx
->task
;
260 struct event_function_struct efs
= {
267 cpu_function_call(event
->cpu
, event_function
, &efs
);
272 if (!task_function_call(task
, event_function
, &efs
))
275 raw_spin_lock_irq(&ctx
->lock
);
276 if (ctx
->is_active
) {
278 * Reload the task pointer, it might have been changed by
279 * a concurrent perf_event_context_sched_out().
282 raw_spin_unlock_irq(&ctx
->lock
);
285 func(event
, NULL
, ctx
, data
);
286 raw_spin_unlock_irq(&ctx
->lock
);
289 #define EVENT_OWNER_KERNEL ((void *) -1)
291 static bool is_kernel_event(struct perf_event
*event
)
293 return event
->owner
== EVENT_OWNER_KERNEL
;
296 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
297 PERF_FLAG_FD_OUTPUT |\
298 PERF_FLAG_PID_CGROUP |\
299 PERF_FLAG_FD_CLOEXEC)
302 * branch priv levels that need permission checks
304 #define PERF_SAMPLE_BRANCH_PERM_PLM \
305 (PERF_SAMPLE_BRANCH_KERNEL |\
306 PERF_SAMPLE_BRANCH_HV)
309 EVENT_FLEXIBLE
= 0x1,
311 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
315 * perf_sched_events : >0 events exist
316 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
318 struct static_key_deferred perf_sched_events __read_mostly
;
319 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
320 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
322 static atomic_t nr_mmap_events __read_mostly
;
323 static atomic_t nr_comm_events __read_mostly
;
324 static atomic_t nr_task_events __read_mostly
;
325 static atomic_t nr_freq_events __read_mostly
;
326 static atomic_t nr_switch_events __read_mostly
;
328 static LIST_HEAD(pmus
);
329 static DEFINE_MUTEX(pmus_lock
);
330 static struct srcu_struct pmus_srcu
;
333 * perf event paranoia level:
334 * -1 - not paranoid at all
335 * 0 - disallow raw tracepoint access for unpriv
336 * 1 - disallow cpu events for unpriv
337 * 2 - disallow kernel profiling for unpriv
339 int sysctl_perf_event_paranoid __read_mostly
= 1;
341 /* Minimum for 512 kiB + 1 user control page */
342 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
345 * max perf event sample rate
347 #define DEFAULT_MAX_SAMPLE_RATE 100000
348 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
349 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
351 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
353 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
354 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
356 static int perf_sample_allowed_ns __read_mostly
=
357 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
359 static void update_perf_cpu_limits(void)
361 u64 tmp
= perf_sample_period_ns
;
363 tmp
*= sysctl_perf_cpu_time_max_percent
;
365 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
368 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
370 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
371 void __user
*buffer
, size_t *lenp
,
374 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
379 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
380 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
381 update_perf_cpu_limits();
386 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
388 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
389 void __user
*buffer
, size_t *lenp
,
392 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
397 update_perf_cpu_limits();
403 * perf samples are done in some very critical code paths (NMIs).
404 * If they take too much CPU time, the system can lock up and not
405 * get any real work done. This will drop the sample rate when
406 * we detect that events are taking too long.
408 #define NR_ACCUMULATED_SAMPLES 128
409 static DEFINE_PER_CPU(u64
, running_sample_length
);
411 static void perf_duration_warn(struct irq_work
*w
)
413 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
414 u64 avg_local_sample_len
;
415 u64 local_samples_len
;
417 local_samples_len
= __this_cpu_read(running_sample_length
);
418 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
420 printk_ratelimited(KERN_WARNING
421 "perf interrupt took too long (%lld > %lld), lowering "
422 "kernel.perf_event_max_sample_rate to %d\n",
423 avg_local_sample_len
, allowed_ns
>> 1,
424 sysctl_perf_event_sample_rate
);
427 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
429 void perf_sample_event_took(u64 sample_len_ns
)
431 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
432 u64 avg_local_sample_len
;
433 u64 local_samples_len
;
438 /* decay the counter by 1 average sample */
439 local_samples_len
= __this_cpu_read(running_sample_length
);
440 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
441 local_samples_len
+= sample_len_ns
;
442 __this_cpu_write(running_sample_length
, local_samples_len
);
445 * note: this will be biased artifically low until we have
446 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
447 * from having to maintain a count.
449 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
451 if (avg_local_sample_len
<= allowed_ns
)
454 if (max_samples_per_tick
<= 1)
457 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
458 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
459 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
461 update_perf_cpu_limits();
463 if (!irq_work_queue(&perf_duration_work
)) {
464 early_printk("perf interrupt took too long (%lld > %lld), lowering "
465 "kernel.perf_event_max_sample_rate to %d\n",
466 avg_local_sample_len
, allowed_ns
>> 1,
467 sysctl_perf_event_sample_rate
);
471 static atomic64_t perf_event_id
;
473 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
474 enum event_type_t event_type
);
476 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
477 enum event_type_t event_type
,
478 struct task_struct
*task
);
480 static void update_context_time(struct perf_event_context
*ctx
);
481 static u64
perf_event_time(struct perf_event
*event
);
483 void __weak
perf_event_print_debug(void) { }
485 extern __weak
const char *perf_pmu_name(void)
490 static inline u64
perf_clock(void)
492 return local_clock();
495 static inline u64
perf_event_clock(struct perf_event
*event
)
497 return event
->clock();
500 #ifdef CONFIG_CGROUP_PERF
503 perf_cgroup_match(struct perf_event
*event
)
505 struct perf_event_context
*ctx
= event
->ctx
;
506 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
508 /* @event doesn't care about cgroup */
512 /* wants specific cgroup scope but @cpuctx isn't associated with any */
517 * Cgroup scoping is recursive. An event enabled for a cgroup is
518 * also enabled for all its descendant cgroups. If @cpuctx's
519 * cgroup is a descendant of @event's (the test covers identity
520 * case), it's a match.
522 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
523 event
->cgrp
->css
.cgroup
);
526 static inline void perf_detach_cgroup(struct perf_event
*event
)
528 css_put(&event
->cgrp
->css
);
532 static inline int is_cgroup_event(struct perf_event
*event
)
534 return event
->cgrp
!= NULL
;
537 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
539 struct perf_cgroup_info
*t
;
541 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
545 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
547 struct perf_cgroup_info
*info
;
552 info
= this_cpu_ptr(cgrp
->info
);
554 info
->time
+= now
- info
->timestamp
;
555 info
->timestamp
= now
;
558 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
560 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
562 __update_cgrp_time(cgrp_out
);
565 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
567 struct perf_cgroup
*cgrp
;
570 * ensure we access cgroup data only when needed and
571 * when we know the cgroup is pinned (css_get)
573 if (!is_cgroup_event(event
))
576 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
578 * Do not update time when cgroup is not active
580 if (cgrp
== event
->cgrp
)
581 __update_cgrp_time(event
->cgrp
);
585 perf_cgroup_set_timestamp(struct task_struct
*task
,
586 struct perf_event_context
*ctx
)
588 struct perf_cgroup
*cgrp
;
589 struct perf_cgroup_info
*info
;
592 * ctx->lock held by caller
593 * ensure we do not access cgroup data
594 * unless we have the cgroup pinned (css_get)
596 if (!task
|| !ctx
->nr_cgroups
)
599 cgrp
= perf_cgroup_from_task(task
, ctx
);
600 info
= this_cpu_ptr(cgrp
->info
);
601 info
->timestamp
= ctx
->timestamp
;
604 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
605 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
608 * reschedule events based on the cgroup constraint of task.
610 * mode SWOUT : schedule out everything
611 * mode SWIN : schedule in based on cgroup for next
613 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
615 struct perf_cpu_context
*cpuctx
;
620 * disable interrupts to avoid geting nr_cgroup
621 * changes via __perf_event_disable(). Also
624 local_irq_save(flags
);
627 * we reschedule only in the presence of cgroup
628 * constrained events.
631 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
632 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
633 if (cpuctx
->unique_pmu
!= pmu
)
634 continue; /* ensure we process each cpuctx once */
637 * perf_cgroup_events says at least one
638 * context on this CPU has cgroup events.
640 * ctx->nr_cgroups reports the number of cgroup
641 * events for a context.
643 if (cpuctx
->ctx
.nr_cgroups
> 0) {
644 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
645 perf_pmu_disable(cpuctx
->ctx
.pmu
);
647 if (mode
& PERF_CGROUP_SWOUT
) {
648 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
650 * must not be done before ctxswout due
651 * to event_filter_match() in event_sched_out()
656 if (mode
& PERF_CGROUP_SWIN
) {
657 WARN_ON_ONCE(cpuctx
->cgrp
);
659 * set cgrp before ctxsw in to allow
660 * event_filter_match() to not have to pass
662 * we pass the cpuctx->ctx to perf_cgroup_from_task()
663 * because cgorup events are only per-cpu
665 cpuctx
->cgrp
= perf_cgroup_from_task(task
, &cpuctx
->ctx
);
666 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
668 perf_pmu_enable(cpuctx
->ctx
.pmu
);
669 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
673 local_irq_restore(flags
);
676 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
677 struct task_struct
*next
)
679 struct perf_cgroup
*cgrp1
;
680 struct perf_cgroup
*cgrp2
= NULL
;
684 * we come here when we know perf_cgroup_events > 0
685 * we do not need to pass the ctx here because we know
686 * we are holding the rcu lock
688 cgrp1
= perf_cgroup_from_task(task
, NULL
);
689 cgrp2
= perf_cgroup_from_task(next
, NULL
);
692 * only schedule out current cgroup events if we know
693 * that we are switching to a different cgroup. Otherwise,
694 * do no touch the cgroup events.
697 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
702 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
703 struct task_struct
*task
)
705 struct perf_cgroup
*cgrp1
;
706 struct perf_cgroup
*cgrp2
= NULL
;
710 * we come here when we know perf_cgroup_events > 0
711 * we do not need to pass the ctx here because we know
712 * we are holding the rcu lock
714 cgrp1
= perf_cgroup_from_task(task
, NULL
);
715 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
718 * only need to schedule in cgroup events if we are changing
719 * cgroup during ctxsw. Cgroup events were not scheduled
720 * out of ctxsw out if that was not the case.
723 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
728 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
729 struct perf_event_attr
*attr
,
730 struct perf_event
*group_leader
)
732 struct perf_cgroup
*cgrp
;
733 struct cgroup_subsys_state
*css
;
734 struct fd f
= fdget(fd
);
740 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
741 &perf_event_cgrp_subsys
);
747 cgrp
= container_of(css
, struct perf_cgroup
, css
);
751 * all events in a group must monitor
752 * the same cgroup because a task belongs
753 * to only one perf cgroup at a time
755 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
756 perf_detach_cgroup(event
);
765 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
767 struct perf_cgroup_info
*t
;
768 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
769 event
->shadow_ctx_time
= now
- t
->timestamp
;
773 perf_cgroup_defer_enabled(struct perf_event
*event
)
776 * when the current task's perf cgroup does not match
777 * the event's, we need to remember to call the
778 * perf_mark_enable() function the first time a task with
779 * a matching perf cgroup is scheduled in.
781 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
782 event
->cgrp_defer_enabled
= 1;
786 perf_cgroup_mark_enabled(struct perf_event
*event
,
787 struct perf_event_context
*ctx
)
789 struct perf_event
*sub
;
790 u64 tstamp
= perf_event_time(event
);
792 if (!event
->cgrp_defer_enabled
)
795 event
->cgrp_defer_enabled
= 0;
797 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
798 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
799 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
800 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
801 sub
->cgrp_defer_enabled
= 0;
805 #else /* !CONFIG_CGROUP_PERF */
808 perf_cgroup_match(struct perf_event
*event
)
813 static inline void perf_detach_cgroup(struct perf_event
*event
)
816 static inline int is_cgroup_event(struct perf_event
*event
)
821 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
826 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
830 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
834 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
835 struct task_struct
*next
)
839 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
840 struct task_struct
*task
)
844 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
845 struct perf_event_attr
*attr
,
846 struct perf_event
*group_leader
)
852 perf_cgroup_set_timestamp(struct task_struct
*task
,
853 struct perf_event_context
*ctx
)
858 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
863 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
867 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
873 perf_cgroup_defer_enabled(struct perf_event
*event
)
878 perf_cgroup_mark_enabled(struct perf_event
*event
,
879 struct perf_event_context
*ctx
)
885 * set default to be dependent on timer tick just
888 #define PERF_CPU_HRTIMER (1000 / HZ)
890 * function must be called with interrupts disbled
892 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
894 struct perf_cpu_context
*cpuctx
;
897 WARN_ON(!irqs_disabled());
899 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
900 rotations
= perf_rotate_context(cpuctx
);
902 raw_spin_lock(&cpuctx
->hrtimer_lock
);
904 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
906 cpuctx
->hrtimer_active
= 0;
907 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
909 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
912 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
914 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
915 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
918 /* no multiplexing needed for SW PMU */
919 if (pmu
->task_ctx_nr
== perf_sw_context
)
923 * check default is sane, if not set then force to
924 * default interval (1/tick)
926 interval
= pmu
->hrtimer_interval_ms
;
928 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
930 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
932 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
933 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
934 timer
->function
= perf_mux_hrtimer_handler
;
937 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
939 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
940 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
944 if (pmu
->task_ctx_nr
== perf_sw_context
)
947 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
948 if (!cpuctx
->hrtimer_active
) {
949 cpuctx
->hrtimer_active
= 1;
950 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
951 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
953 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
958 void perf_pmu_disable(struct pmu
*pmu
)
960 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
962 pmu
->pmu_disable(pmu
);
965 void perf_pmu_enable(struct pmu
*pmu
)
967 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
969 pmu
->pmu_enable(pmu
);
972 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
975 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
976 * perf_event_task_tick() are fully serialized because they're strictly cpu
977 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
978 * disabled, while perf_event_task_tick is called from IRQ context.
980 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
982 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
984 WARN_ON(!irqs_disabled());
986 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
988 list_add(&ctx
->active_ctx_list
, head
);
991 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
993 WARN_ON(!irqs_disabled());
995 WARN_ON(list_empty(&ctx
->active_ctx_list
));
997 list_del_init(&ctx
->active_ctx_list
);
1000 static void get_ctx(struct perf_event_context
*ctx
)
1002 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1005 static void free_ctx(struct rcu_head
*head
)
1007 struct perf_event_context
*ctx
;
1009 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1010 kfree(ctx
->task_ctx_data
);
1014 static void put_ctx(struct perf_event_context
*ctx
)
1016 if (atomic_dec_and_test(&ctx
->refcount
)) {
1017 if (ctx
->parent_ctx
)
1018 put_ctx(ctx
->parent_ctx
);
1020 put_task_struct(ctx
->task
);
1021 call_rcu(&ctx
->rcu_head
, free_ctx
);
1026 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1027 * perf_pmu_migrate_context() we need some magic.
1029 * Those places that change perf_event::ctx will hold both
1030 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1032 * Lock ordering is by mutex address. There are two other sites where
1033 * perf_event_context::mutex nests and those are:
1035 * - perf_event_exit_task_context() [ child , 0 ]
1036 * __perf_event_exit_task()
1037 * sync_child_event()
1038 * put_event() [ parent, 1 ]
1040 * - perf_event_init_context() [ parent, 0 ]
1041 * inherit_task_group()
1044 * perf_event_alloc()
1046 * perf_try_init_event() [ child , 1 ]
1048 * While it appears there is an obvious deadlock here -- the parent and child
1049 * nesting levels are inverted between the two. This is in fact safe because
1050 * life-time rules separate them. That is an exiting task cannot fork, and a
1051 * spawning task cannot (yet) exit.
1053 * But remember that that these are parent<->child context relations, and
1054 * migration does not affect children, therefore these two orderings should not
1057 * The change in perf_event::ctx does not affect children (as claimed above)
1058 * because the sys_perf_event_open() case will install a new event and break
1059 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1060 * concerned with cpuctx and that doesn't have children.
1062 * The places that change perf_event::ctx will issue:
1064 * perf_remove_from_context();
1065 * synchronize_rcu();
1066 * perf_install_in_context();
1068 * to affect the change. The remove_from_context() + synchronize_rcu() should
1069 * quiesce the event, after which we can install it in the new location. This
1070 * means that only external vectors (perf_fops, prctl) can perturb the event
1071 * while in transit. Therefore all such accessors should also acquire
1072 * perf_event_context::mutex to serialize against this.
1074 * However; because event->ctx can change while we're waiting to acquire
1075 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1079 * task_struct::perf_event_mutex
1080 * perf_event_context::mutex
1081 * perf_event_context::lock
1082 * perf_event::child_mutex;
1083 * perf_event::mmap_mutex
1086 static struct perf_event_context
*
1087 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1089 struct perf_event_context
*ctx
;
1093 ctx
= ACCESS_ONCE(event
->ctx
);
1094 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1100 mutex_lock_nested(&ctx
->mutex
, nesting
);
1101 if (event
->ctx
!= ctx
) {
1102 mutex_unlock(&ctx
->mutex
);
1110 static inline struct perf_event_context
*
1111 perf_event_ctx_lock(struct perf_event
*event
)
1113 return perf_event_ctx_lock_nested(event
, 0);
1116 static void perf_event_ctx_unlock(struct perf_event
*event
,
1117 struct perf_event_context
*ctx
)
1119 mutex_unlock(&ctx
->mutex
);
1124 * This must be done under the ctx->lock, such as to serialize against
1125 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1126 * calling scheduler related locks and ctx->lock nests inside those.
1128 static __must_check
struct perf_event_context
*
1129 unclone_ctx(struct perf_event_context
*ctx
)
1131 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1133 lockdep_assert_held(&ctx
->lock
);
1136 ctx
->parent_ctx
= NULL
;
1142 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1145 * only top level events have the pid namespace they were created in
1148 event
= event
->parent
;
1150 return task_tgid_nr_ns(p
, event
->ns
);
1153 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1156 * only top level events have the pid namespace they were created in
1159 event
= event
->parent
;
1161 return task_pid_nr_ns(p
, event
->ns
);
1165 * If we inherit events we want to return the parent event id
1168 static u64
primary_event_id(struct perf_event
*event
)
1173 id
= event
->parent
->id
;
1179 * Get the perf_event_context for a task and lock it.
1180 * This has to cope with with the fact that until it is locked,
1181 * the context could get moved to another task.
1183 static struct perf_event_context
*
1184 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1186 struct perf_event_context
*ctx
;
1190 * One of the few rules of preemptible RCU is that one cannot do
1191 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1192 * part of the read side critical section was irqs-enabled -- see
1193 * rcu_read_unlock_special().
1195 * Since ctx->lock nests under rq->lock we must ensure the entire read
1196 * side critical section has interrupts disabled.
1198 local_irq_save(*flags
);
1200 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1203 * If this context is a clone of another, it might
1204 * get swapped for another underneath us by
1205 * perf_event_task_sched_out, though the
1206 * rcu_read_lock() protects us from any context
1207 * getting freed. Lock the context and check if it
1208 * got swapped before we could get the lock, and retry
1209 * if so. If we locked the right context, then it
1210 * can't get swapped on us any more.
1212 raw_spin_lock(&ctx
->lock
);
1213 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1214 raw_spin_unlock(&ctx
->lock
);
1216 local_irq_restore(*flags
);
1220 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1221 raw_spin_unlock(&ctx
->lock
);
1227 local_irq_restore(*flags
);
1232 * Get the context for a task and increment its pin_count so it
1233 * can't get swapped to another task. This also increments its
1234 * reference count so that the context can't get freed.
1236 static struct perf_event_context
*
1237 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1239 struct perf_event_context
*ctx
;
1240 unsigned long flags
;
1242 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1245 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1250 static void perf_unpin_context(struct perf_event_context
*ctx
)
1252 unsigned long flags
;
1254 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1256 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1260 * Update the record of the current time in a context.
1262 static void update_context_time(struct perf_event_context
*ctx
)
1264 u64 now
= perf_clock();
1266 ctx
->time
+= now
- ctx
->timestamp
;
1267 ctx
->timestamp
= now
;
1270 static u64
perf_event_time(struct perf_event
*event
)
1272 struct perf_event_context
*ctx
= event
->ctx
;
1274 if (is_cgroup_event(event
))
1275 return perf_cgroup_event_time(event
);
1277 return ctx
? ctx
->time
: 0;
1281 * Update the total_time_enabled and total_time_running fields for a event.
1282 * The caller of this function needs to hold the ctx->lock.
1284 static void update_event_times(struct perf_event
*event
)
1286 struct perf_event_context
*ctx
= event
->ctx
;
1289 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1290 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1293 * in cgroup mode, time_enabled represents
1294 * the time the event was enabled AND active
1295 * tasks were in the monitored cgroup. This is
1296 * independent of the activity of the context as
1297 * there may be a mix of cgroup and non-cgroup events.
1299 * That is why we treat cgroup events differently
1302 if (is_cgroup_event(event
))
1303 run_end
= perf_cgroup_event_time(event
);
1304 else if (ctx
->is_active
)
1305 run_end
= ctx
->time
;
1307 run_end
= event
->tstamp_stopped
;
1309 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1311 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1312 run_end
= event
->tstamp_stopped
;
1314 run_end
= perf_event_time(event
);
1316 event
->total_time_running
= run_end
- event
->tstamp_running
;
1321 * Update total_time_enabled and total_time_running for all events in a group.
1323 static void update_group_times(struct perf_event
*leader
)
1325 struct perf_event
*event
;
1327 update_event_times(leader
);
1328 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1329 update_event_times(event
);
1332 static struct list_head
*
1333 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1335 if (event
->attr
.pinned
)
1336 return &ctx
->pinned_groups
;
1338 return &ctx
->flexible_groups
;
1342 * Add a event from the lists for its context.
1343 * Must be called with ctx->mutex and ctx->lock held.
1346 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1348 lockdep_assert_held(&ctx
->lock
);
1350 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1351 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1354 * If we're a stand alone event or group leader, we go to the context
1355 * list, group events are kept attached to the group so that
1356 * perf_group_detach can, at all times, locate all siblings.
1358 if (event
->group_leader
== event
) {
1359 struct list_head
*list
;
1361 if (is_software_event(event
))
1362 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1364 list
= ctx_group_list(event
, ctx
);
1365 list_add_tail(&event
->group_entry
, list
);
1368 if (is_cgroup_event(event
))
1371 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1373 if (event
->attr
.inherit_stat
)
1380 * Initialize event state based on the perf_event_attr::disabled.
1382 static inline void perf_event__state_init(struct perf_event
*event
)
1384 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1385 PERF_EVENT_STATE_INACTIVE
;
1388 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1390 int entry
= sizeof(u64
); /* value */
1394 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1395 size
+= sizeof(u64
);
1397 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1398 size
+= sizeof(u64
);
1400 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1401 entry
+= sizeof(u64
);
1403 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1405 size
+= sizeof(u64
);
1409 event
->read_size
= size
;
1412 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1414 struct perf_sample_data
*data
;
1417 if (sample_type
& PERF_SAMPLE_IP
)
1418 size
+= sizeof(data
->ip
);
1420 if (sample_type
& PERF_SAMPLE_ADDR
)
1421 size
+= sizeof(data
->addr
);
1423 if (sample_type
& PERF_SAMPLE_PERIOD
)
1424 size
+= sizeof(data
->period
);
1426 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1427 size
+= sizeof(data
->weight
);
1429 if (sample_type
& PERF_SAMPLE_READ
)
1430 size
+= event
->read_size
;
1432 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1433 size
+= sizeof(data
->data_src
.val
);
1435 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1436 size
+= sizeof(data
->txn
);
1438 event
->header_size
= size
;
1442 * Called at perf_event creation and when events are attached/detached from a
1445 static void perf_event__header_size(struct perf_event
*event
)
1447 __perf_event_read_size(event
,
1448 event
->group_leader
->nr_siblings
);
1449 __perf_event_header_size(event
, event
->attr
.sample_type
);
1452 static void perf_event__id_header_size(struct perf_event
*event
)
1454 struct perf_sample_data
*data
;
1455 u64 sample_type
= event
->attr
.sample_type
;
1458 if (sample_type
& PERF_SAMPLE_TID
)
1459 size
+= sizeof(data
->tid_entry
);
1461 if (sample_type
& PERF_SAMPLE_TIME
)
1462 size
+= sizeof(data
->time
);
1464 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1465 size
+= sizeof(data
->id
);
1467 if (sample_type
& PERF_SAMPLE_ID
)
1468 size
+= sizeof(data
->id
);
1470 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1471 size
+= sizeof(data
->stream_id
);
1473 if (sample_type
& PERF_SAMPLE_CPU
)
1474 size
+= sizeof(data
->cpu_entry
);
1476 event
->id_header_size
= size
;
1479 static bool perf_event_validate_size(struct perf_event
*event
)
1482 * The values computed here will be over-written when we actually
1485 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1486 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1487 perf_event__id_header_size(event
);
1490 * Sum the lot; should not exceed the 64k limit we have on records.
1491 * Conservative limit to allow for callchains and other variable fields.
1493 if (event
->read_size
+ event
->header_size
+
1494 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1500 static void perf_group_attach(struct perf_event
*event
)
1502 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1505 * We can have double attach due to group movement in perf_event_open.
1507 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1510 event
->attach_state
|= PERF_ATTACH_GROUP
;
1512 if (group_leader
== event
)
1515 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1517 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1518 !is_software_event(event
))
1519 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1521 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1522 group_leader
->nr_siblings
++;
1524 perf_event__header_size(group_leader
);
1526 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1527 perf_event__header_size(pos
);
1531 * Remove a event from the lists for its context.
1532 * Must be called with ctx->mutex and ctx->lock held.
1535 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1537 struct perf_cpu_context
*cpuctx
;
1539 WARN_ON_ONCE(event
->ctx
!= ctx
);
1540 lockdep_assert_held(&ctx
->lock
);
1543 * We can have double detach due to exit/hot-unplug + close.
1545 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1548 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1550 if (is_cgroup_event(event
)) {
1553 * Because cgroup events are always per-cpu events, this will
1554 * always be called from the right CPU.
1556 cpuctx
= __get_cpu_context(ctx
);
1558 * If there are no more cgroup events then clear cgrp to avoid
1559 * stale pointer in update_cgrp_time_from_cpuctx().
1561 if (!ctx
->nr_cgroups
)
1562 cpuctx
->cgrp
= NULL
;
1566 if (event
->attr
.inherit_stat
)
1569 list_del_rcu(&event
->event_entry
);
1571 if (event
->group_leader
== event
)
1572 list_del_init(&event
->group_entry
);
1574 update_group_times(event
);
1577 * If event was in error state, then keep it
1578 * that way, otherwise bogus counts will be
1579 * returned on read(). The only way to get out
1580 * of error state is by explicit re-enabling
1583 if (event
->state
> PERF_EVENT_STATE_OFF
)
1584 event
->state
= PERF_EVENT_STATE_OFF
;
1589 static void perf_group_detach(struct perf_event
*event
)
1591 struct perf_event
*sibling
, *tmp
;
1592 struct list_head
*list
= NULL
;
1595 * We can have double detach due to exit/hot-unplug + close.
1597 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1600 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1603 * If this is a sibling, remove it from its group.
1605 if (event
->group_leader
!= event
) {
1606 list_del_init(&event
->group_entry
);
1607 event
->group_leader
->nr_siblings
--;
1611 if (!list_empty(&event
->group_entry
))
1612 list
= &event
->group_entry
;
1615 * If this was a group event with sibling events then
1616 * upgrade the siblings to singleton events by adding them
1617 * to whatever list we are on.
1619 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1621 list_move_tail(&sibling
->group_entry
, list
);
1622 sibling
->group_leader
= sibling
;
1624 /* Inherit group flags from the previous leader */
1625 sibling
->group_flags
= event
->group_flags
;
1627 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1631 perf_event__header_size(event
->group_leader
);
1633 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1634 perf_event__header_size(tmp
);
1638 * User event without the task.
1640 static bool is_orphaned_event(struct perf_event
*event
)
1642 return event
&& !is_kernel_event(event
) && !event
->owner
;
1646 * Event has a parent but parent's task finished and it's
1647 * alive only because of children holding refference.
1649 static bool is_orphaned_child(struct perf_event
*event
)
1651 return is_orphaned_event(event
->parent
);
1654 static void orphans_remove_work(struct work_struct
*work
);
1656 static void schedule_orphans_remove(struct perf_event_context
*ctx
)
1658 if (!ctx
->task
|| ctx
->orphans_remove_sched
|| !perf_wq
)
1661 if (queue_delayed_work(perf_wq
, &ctx
->orphans_remove
, 1)) {
1663 ctx
->orphans_remove_sched
= true;
1667 static int __init
perf_workqueue_init(void)
1669 perf_wq
= create_singlethread_workqueue("perf");
1670 WARN(!perf_wq
, "failed to create perf workqueue\n");
1671 return perf_wq
? 0 : -1;
1674 core_initcall(perf_workqueue_init
);
1676 static inline int pmu_filter_match(struct perf_event
*event
)
1678 struct pmu
*pmu
= event
->pmu
;
1679 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1683 event_filter_match(struct perf_event
*event
)
1685 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1686 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1690 event_sched_out(struct perf_event
*event
,
1691 struct perf_cpu_context
*cpuctx
,
1692 struct perf_event_context
*ctx
)
1694 u64 tstamp
= perf_event_time(event
);
1697 WARN_ON_ONCE(event
->ctx
!= ctx
);
1698 lockdep_assert_held(&ctx
->lock
);
1701 * An event which could not be activated because of
1702 * filter mismatch still needs to have its timings
1703 * maintained, otherwise bogus information is return
1704 * via read() for time_enabled, time_running:
1706 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1707 && !event_filter_match(event
)) {
1708 delta
= tstamp
- event
->tstamp_stopped
;
1709 event
->tstamp_running
+= delta
;
1710 event
->tstamp_stopped
= tstamp
;
1713 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1716 perf_pmu_disable(event
->pmu
);
1718 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1719 if (event
->pending_disable
) {
1720 event
->pending_disable
= 0;
1721 event
->state
= PERF_EVENT_STATE_OFF
;
1723 event
->tstamp_stopped
= tstamp
;
1724 event
->pmu
->del(event
, 0);
1727 if (!is_software_event(event
))
1728 cpuctx
->active_oncpu
--;
1729 if (!--ctx
->nr_active
)
1730 perf_event_ctx_deactivate(ctx
);
1731 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1733 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1734 cpuctx
->exclusive
= 0;
1736 if (is_orphaned_child(event
))
1737 schedule_orphans_remove(ctx
);
1739 perf_pmu_enable(event
->pmu
);
1743 group_sched_out(struct perf_event
*group_event
,
1744 struct perf_cpu_context
*cpuctx
,
1745 struct perf_event_context
*ctx
)
1747 struct perf_event
*event
;
1748 int state
= group_event
->state
;
1750 event_sched_out(group_event
, cpuctx
, ctx
);
1753 * Schedule out siblings (if any):
1755 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1756 event_sched_out(event
, cpuctx
, ctx
);
1758 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1759 cpuctx
->exclusive
= 0;
1763 * Cross CPU call to remove a performance event
1765 * We disable the event on the hardware level first. After that we
1766 * remove it from the context list.
1769 __perf_remove_from_context(struct perf_event
*event
,
1770 struct perf_cpu_context
*cpuctx
,
1771 struct perf_event_context
*ctx
,
1774 bool detach_group
= (unsigned long)info
;
1776 event_sched_out(event
, cpuctx
, ctx
);
1778 perf_group_detach(event
);
1779 list_del_event(event
, ctx
);
1781 if (!ctx
->nr_events
&& ctx
->is_active
) {
1784 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1785 cpuctx
->task_ctx
= NULL
;
1791 * Remove the event from a task's (or a CPU's) list of events.
1793 * If event->ctx is a cloned context, callers must make sure that
1794 * every task struct that event->ctx->task could possibly point to
1795 * remains valid. This is OK when called from perf_release since
1796 * that only calls us on the top-level context, which can't be a clone.
1797 * When called from perf_event_exit_task, it's OK because the
1798 * context has been detached from its task.
1800 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1802 lockdep_assert_held(&event
->ctx
->mutex
);
1804 event_function_call(event
, __perf_remove_from_context
,
1805 (void *)(unsigned long)detach_group
);
1809 * Cross CPU call to disable a performance event
1811 static void __perf_event_disable(struct perf_event
*event
,
1812 struct perf_cpu_context
*cpuctx
,
1813 struct perf_event_context
*ctx
,
1816 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1819 update_context_time(ctx
);
1820 update_cgrp_time_from_event(event
);
1821 update_group_times(event
);
1822 if (event
== event
->group_leader
)
1823 group_sched_out(event
, cpuctx
, ctx
);
1825 event_sched_out(event
, cpuctx
, ctx
);
1826 event
->state
= PERF_EVENT_STATE_OFF
;
1832 * If event->ctx is a cloned context, callers must make sure that
1833 * every task struct that event->ctx->task could possibly point to
1834 * remains valid. This condition is satisifed when called through
1835 * perf_event_for_each_child or perf_event_for_each because they
1836 * hold the top-level event's child_mutex, so any descendant that
1837 * goes to exit will block in sync_child_event.
1838 * When called from perf_pending_event it's OK because event->ctx
1839 * is the current context on this CPU and preemption is disabled,
1840 * hence we can't get into perf_event_task_sched_out for this context.
1842 static void _perf_event_disable(struct perf_event
*event
)
1844 struct perf_event_context
*ctx
= event
->ctx
;
1846 raw_spin_lock_irq(&ctx
->lock
);
1847 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1848 raw_spin_unlock_irq(&ctx
->lock
);
1851 raw_spin_unlock_irq(&ctx
->lock
);
1853 event_function_call(event
, __perf_event_disable
, NULL
);
1856 void perf_event_disable_local(struct perf_event
*event
)
1858 event_function_local(event
, __perf_event_disable
, NULL
);
1862 * Strictly speaking kernel users cannot create groups and therefore this
1863 * interface does not need the perf_event_ctx_lock() magic.
1865 void perf_event_disable(struct perf_event
*event
)
1867 struct perf_event_context
*ctx
;
1869 ctx
= perf_event_ctx_lock(event
);
1870 _perf_event_disable(event
);
1871 perf_event_ctx_unlock(event
, ctx
);
1873 EXPORT_SYMBOL_GPL(perf_event_disable
);
1875 static void perf_set_shadow_time(struct perf_event
*event
,
1876 struct perf_event_context
*ctx
,
1880 * use the correct time source for the time snapshot
1882 * We could get by without this by leveraging the
1883 * fact that to get to this function, the caller
1884 * has most likely already called update_context_time()
1885 * and update_cgrp_time_xx() and thus both timestamp
1886 * are identical (or very close). Given that tstamp is,
1887 * already adjusted for cgroup, we could say that:
1888 * tstamp - ctx->timestamp
1890 * tstamp - cgrp->timestamp.
1892 * Then, in perf_output_read(), the calculation would
1893 * work with no changes because:
1894 * - event is guaranteed scheduled in
1895 * - no scheduled out in between
1896 * - thus the timestamp would be the same
1898 * But this is a bit hairy.
1900 * So instead, we have an explicit cgroup call to remain
1901 * within the time time source all along. We believe it
1902 * is cleaner and simpler to understand.
1904 if (is_cgroup_event(event
))
1905 perf_cgroup_set_shadow_time(event
, tstamp
);
1907 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1910 #define MAX_INTERRUPTS (~0ULL)
1912 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1913 static void perf_log_itrace_start(struct perf_event
*event
);
1916 event_sched_in(struct perf_event
*event
,
1917 struct perf_cpu_context
*cpuctx
,
1918 struct perf_event_context
*ctx
)
1920 u64 tstamp
= perf_event_time(event
);
1923 lockdep_assert_held(&ctx
->lock
);
1925 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1928 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1929 event
->oncpu
= smp_processor_id();
1932 * Unthrottle events, since we scheduled we might have missed several
1933 * ticks already, also for a heavily scheduling task there is little
1934 * guarantee it'll get a tick in a timely manner.
1936 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1937 perf_log_throttle(event
, 1);
1938 event
->hw
.interrupts
= 0;
1942 * The new state must be visible before we turn it on in the hardware:
1946 perf_pmu_disable(event
->pmu
);
1948 perf_set_shadow_time(event
, ctx
, tstamp
);
1950 perf_log_itrace_start(event
);
1952 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1953 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1959 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1961 if (!is_software_event(event
))
1962 cpuctx
->active_oncpu
++;
1963 if (!ctx
->nr_active
++)
1964 perf_event_ctx_activate(ctx
);
1965 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1968 if (event
->attr
.exclusive
)
1969 cpuctx
->exclusive
= 1;
1971 if (is_orphaned_child(event
))
1972 schedule_orphans_remove(ctx
);
1975 perf_pmu_enable(event
->pmu
);
1981 group_sched_in(struct perf_event
*group_event
,
1982 struct perf_cpu_context
*cpuctx
,
1983 struct perf_event_context
*ctx
)
1985 struct perf_event
*event
, *partial_group
= NULL
;
1986 struct pmu
*pmu
= ctx
->pmu
;
1987 u64 now
= ctx
->time
;
1988 bool simulate
= false;
1990 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1993 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
1995 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1996 pmu
->cancel_txn(pmu
);
1997 perf_mux_hrtimer_restart(cpuctx
);
2002 * Schedule in siblings as one group (if any):
2004 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2005 if (event_sched_in(event
, cpuctx
, ctx
)) {
2006 partial_group
= event
;
2011 if (!pmu
->commit_txn(pmu
))
2016 * Groups can be scheduled in as one unit only, so undo any
2017 * partial group before returning:
2018 * The events up to the failed event are scheduled out normally,
2019 * tstamp_stopped will be updated.
2021 * The failed events and the remaining siblings need to have
2022 * their timings updated as if they had gone thru event_sched_in()
2023 * and event_sched_out(). This is required to get consistent timings
2024 * across the group. This also takes care of the case where the group
2025 * could never be scheduled by ensuring tstamp_stopped is set to mark
2026 * the time the event was actually stopped, such that time delta
2027 * calculation in update_event_times() is correct.
2029 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2030 if (event
== partial_group
)
2034 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2035 event
->tstamp_stopped
= now
;
2037 event_sched_out(event
, cpuctx
, ctx
);
2040 event_sched_out(group_event
, cpuctx
, ctx
);
2042 pmu
->cancel_txn(pmu
);
2044 perf_mux_hrtimer_restart(cpuctx
);
2050 * Work out whether we can put this event group on the CPU now.
2052 static int group_can_go_on(struct perf_event
*event
,
2053 struct perf_cpu_context
*cpuctx
,
2057 * Groups consisting entirely of software events can always go on.
2059 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2062 * If an exclusive group is already on, no other hardware
2065 if (cpuctx
->exclusive
)
2068 * If this group is exclusive and there are already
2069 * events on the CPU, it can't go on.
2071 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2074 * Otherwise, try to add it if all previous groups were able
2080 static void add_event_to_ctx(struct perf_event
*event
,
2081 struct perf_event_context
*ctx
)
2083 u64 tstamp
= perf_event_time(event
);
2085 list_add_event(event
, ctx
);
2086 perf_group_attach(event
);
2087 event
->tstamp_enabled
= tstamp
;
2088 event
->tstamp_running
= tstamp
;
2089 event
->tstamp_stopped
= tstamp
;
2092 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2093 struct perf_event_context
*ctx
);
2095 ctx_sched_in(struct perf_event_context
*ctx
,
2096 struct perf_cpu_context
*cpuctx
,
2097 enum event_type_t event_type
,
2098 struct task_struct
*task
);
2100 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2101 struct perf_event_context
*ctx
,
2102 struct task_struct
*task
)
2104 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2106 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2107 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2109 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2112 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2113 struct perf_event_context
*task_ctx
)
2115 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2117 task_ctx_sched_out(cpuctx
, task_ctx
);
2118 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2119 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2120 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2124 * Cross CPU call to install and enable a performance event
2126 * Must be called with ctx->mutex held
2128 static int __perf_install_in_context(void *info
)
2130 struct perf_event_context
*ctx
= info
;
2131 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2132 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2136 * If we hit the 'wrong' task, we've since scheduled and
2137 * everything should be sorted, nothing to do!
2139 if (ctx
->task
!= current
)
2143 * If task_ctx is set, it had better be to us.
2145 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
&& cpuctx
->task_ctx
);
2149 perf_ctx_lock(cpuctx
, task_ctx
);
2150 ctx_resched(cpuctx
, task_ctx
);
2151 perf_ctx_unlock(cpuctx
, task_ctx
);
2157 * Attach a performance event to a context
2160 perf_install_in_context(struct perf_event_context
*ctx
,
2161 struct perf_event
*event
,
2164 struct task_struct
*task
= NULL
;
2166 lockdep_assert_held(&ctx
->mutex
);
2169 if (event
->cpu
!= -1)
2173 * Installing events is tricky because we cannot rely on ctx->is_active
2174 * to be set in case this is the nr_events 0 -> 1 transition.
2176 * So what we do is we add the event to the list here, which will allow
2177 * a future context switch to DTRT and then send a racy IPI. If the IPI
2178 * fails to hit the right task, this means a context switch must have
2179 * happened and that will have taken care of business.
2181 raw_spin_lock_irq(&ctx
->lock
);
2182 update_context_time(ctx
);
2184 * Update cgrp time only if current cgrp matches event->cgrp.
2185 * Must be done before calling add_event_to_ctx().
2187 update_cgrp_time_from_event(event
);
2188 add_event_to_ctx(event
, ctx
);
2190 raw_spin_unlock_irq(&ctx
->lock
);
2193 task_function_call(task
, __perf_install_in_context
, ctx
);
2195 cpu_function_call(cpu
, __perf_install_in_context
, ctx
);
2199 * Put a event into inactive state and update time fields.
2200 * Enabling the leader of a group effectively enables all
2201 * the group members that aren't explicitly disabled, so we
2202 * have to update their ->tstamp_enabled also.
2203 * Note: this works for group members as well as group leaders
2204 * since the non-leader members' sibling_lists will be empty.
2206 static void __perf_event_mark_enabled(struct perf_event
*event
)
2208 struct perf_event
*sub
;
2209 u64 tstamp
= perf_event_time(event
);
2211 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2212 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2213 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2214 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2215 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2220 * Cross CPU call to enable a performance event
2222 static void __perf_event_enable(struct perf_event
*event
,
2223 struct perf_cpu_context
*cpuctx
,
2224 struct perf_event_context
*ctx
,
2227 struct perf_event
*leader
= event
->group_leader
;
2228 struct perf_event_context
*task_ctx
;
2230 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2233 update_context_time(ctx
);
2234 __perf_event_mark_enabled(event
);
2236 if (!ctx
->is_active
)
2239 if (!event_filter_match(event
)) {
2240 if (is_cgroup_event(event
)) {
2241 perf_cgroup_set_timestamp(current
, ctx
); // XXX ?
2242 perf_cgroup_defer_enabled(event
);
2248 * If the event is in a group and isn't the group leader,
2249 * then don't put it on unless the group is on.
2251 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2254 task_ctx
= cpuctx
->task_ctx
;
2256 WARN_ON_ONCE(task_ctx
!= ctx
);
2258 ctx_resched(cpuctx
, task_ctx
);
2264 * If event->ctx is a cloned context, callers must make sure that
2265 * every task struct that event->ctx->task could possibly point to
2266 * remains valid. This condition is satisfied when called through
2267 * perf_event_for_each_child or perf_event_for_each as described
2268 * for perf_event_disable.
2270 static void _perf_event_enable(struct perf_event
*event
)
2272 struct perf_event_context
*ctx
= event
->ctx
;
2274 raw_spin_lock_irq(&ctx
->lock
);
2275 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
2276 raw_spin_unlock_irq(&ctx
->lock
);
2281 * If the event is in error state, clear that first.
2283 * That way, if we see the event in error state below, we know that it
2284 * has gone back into error state, as distinct from the task having
2285 * been scheduled away before the cross-call arrived.
2287 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2288 event
->state
= PERF_EVENT_STATE_OFF
;
2289 raw_spin_unlock_irq(&ctx
->lock
);
2291 event_function_call(event
, __perf_event_enable
, NULL
);
2295 * See perf_event_disable();
2297 void perf_event_enable(struct perf_event
*event
)
2299 struct perf_event_context
*ctx
;
2301 ctx
= perf_event_ctx_lock(event
);
2302 _perf_event_enable(event
);
2303 perf_event_ctx_unlock(event
, ctx
);
2305 EXPORT_SYMBOL_GPL(perf_event_enable
);
2307 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2310 * not supported on inherited events
2312 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2315 atomic_add(refresh
, &event
->event_limit
);
2316 _perf_event_enable(event
);
2322 * See perf_event_disable()
2324 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2326 struct perf_event_context
*ctx
;
2329 ctx
= perf_event_ctx_lock(event
);
2330 ret
= _perf_event_refresh(event
, refresh
);
2331 perf_event_ctx_unlock(event
, ctx
);
2335 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2337 static void ctx_sched_out(struct perf_event_context
*ctx
,
2338 struct perf_cpu_context
*cpuctx
,
2339 enum event_type_t event_type
)
2341 int is_active
= ctx
->is_active
;
2342 struct perf_event
*event
;
2344 lockdep_assert_held(&ctx
->lock
);
2346 if (likely(!ctx
->nr_events
)) {
2348 * See __perf_remove_from_context().
2350 WARN_ON_ONCE(ctx
->is_active
);
2352 WARN_ON_ONCE(cpuctx
->task_ctx
);
2356 ctx
->is_active
&= ~event_type
;
2358 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2359 if (!ctx
->is_active
)
2360 cpuctx
->task_ctx
= NULL
;
2363 update_context_time(ctx
);
2364 update_cgrp_time_from_cpuctx(cpuctx
);
2365 if (!ctx
->nr_active
)
2368 perf_pmu_disable(ctx
->pmu
);
2369 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2370 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2371 group_sched_out(event
, cpuctx
, ctx
);
2374 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2375 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2376 group_sched_out(event
, cpuctx
, ctx
);
2378 perf_pmu_enable(ctx
->pmu
);
2382 * Test whether two contexts are equivalent, i.e. whether they have both been
2383 * cloned from the same version of the same context.
2385 * Equivalence is measured using a generation number in the context that is
2386 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2387 * and list_del_event().
2389 static int context_equiv(struct perf_event_context
*ctx1
,
2390 struct perf_event_context
*ctx2
)
2392 lockdep_assert_held(&ctx1
->lock
);
2393 lockdep_assert_held(&ctx2
->lock
);
2395 /* Pinning disables the swap optimization */
2396 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2399 /* If ctx1 is the parent of ctx2 */
2400 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2403 /* If ctx2 is the parent of ctx1 */
2404 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2408 * If ctx1 and ctx2 have the same parent; we flatten the parent
2409 * hierarchy, see perf_event_init_context().
2411 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2412 ctx1
->parent_gen
== ctx2
->parent_gen
)
2419 static void __perf_event_sync_stat(struct perf_event
*event
,
2420 struct perf_event
*next_event
)
2424 if (!event
->attr
.inherit_stat
)
2428 * Update the event value, we cannot use perf_event_read()
2429 * because we're in the middle of a context switch and have IRQs
2430 * disabled, which upsets smp_call_function_single(), however
2431 * we know the event must be on the current CPU, therefore we
2432 * don't need to use it.
2434 switch (event
->state
) {
2435 case PERF_EVENT_STATE_ACTIVE
:
2436 event
->pmu
->read(event
);
2439 case PERF_EVENT_STATE_INACTIVE
:
2440 update_event_times(event
);
2448 * In order to keep per-task stats reliable we need to flip the event
2449 * values when we flip the contexts.
2451 value
= local64_read(&next_event
->count
);
2452 value
= local64_xchg(&event
->count
, value
);
2453 local64_set(&next_event
->count
, value
);
2455 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2456 swap(event
->total_time_running
, next_event
->total_time_running
);
2459 * Since we swizzled the values, update the user visible data too.
2461 perf_event_update_userpage(event
);
2462 perf_event_update_userpage(next_event
);
2465 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2466 struct perf_event_context
*next_ctx
)
2468 struct perf_event
*event
, *next_event
;
2473 update_context_time(ctx
);
2475 event
= list_first_entry(&ctx
->event_list
,
2476 struct perf_event
, event_entry
);
2478 next_event
= list_first_entry(&next_ctx
->event_list
,
2479 struct perf_event
, event_entry
);
2481 while (&event
->event_entry
!= &ctx
->event_list
&&
2482 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2484 __perf_event_sync_stat(event
, next_event
);
2486 event
= list_next_entry(event
, event_entry
);
2487 next_event
= list_next_entry(next_event
, event_entry
);
2491 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2492 struct task_struct
*next
)
2494 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2495 struct perf_event_context
*next_ctx
;
2496 struct perf_event_context
*parent
, *next_parent
;
2497 struct perf_cpu_context
*cpuctx
;
2503 cpuctx
= __get_cpu_context(ctx
);
2504 if (!cpuctx
->task_ctx
)
2508 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2512 parent
= rcu_dereference(ctx
->parent_ctx
);
2513 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2515 /* If neither context have a parent context; they cannot be clones. */
2516 if (!parent
&& !next_parent
)
2519 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2521 * Looks like the two contexts are clones, so we might be
2522 * able to optimize the context switch. We lock both
2523 * contexts and check that they are clones under the
2524 * lock (including re-checking that neither has been
2525 * uncloned in the meantime). It doesn't matter which
2526 * order we take the locks because no other cpu could
2527 * be trying to lock both of these tasks.
2529 raw_spin_lock(&ctx
->lock
);
2530 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2531 if (context_equiv(ctx
, next_ctx
)) {
2533 * XXX do we need a memory barrier of sorts
2534 * wrt to rcu_dereference() of perf_event_ctxp
2536 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2537 next
->perf_event_ctxp
[ctxn
] = ctx
;
2539 next_ctx
->task
= task
;
2541 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2545 perf_event_sync_stat(ctx
, next_ctx
);
2547 raw_spin_unlock(&next_ctx
->lock
);
2548 raw_spin_unlock(&ctx
->lock
);
2554 raw_spin_lock(&ctx
->lock
);
2555 task_ctx_sched_out(cpuctx
, ctx
);
2556 raw_spin_unlock(&ctx
->lock
);
2560 void perf_sched_cb_dec(struct pmu
*pmu
)
2562 this_cpu_dec(perf_sched_cb_usages
);
2565 void perf_sched_cb_inc(struct pmu
*pmu
)
2567 this_cpu_inc(perf_sched_cb_usages
);
2571 * This function provides the context switch callback to the lower code
2572 * layer. It is invoked ONLY when the context switch callback is enabled.
2574 static void perf_pmu_sched_task(struct task_struct
*prev
,
2575 struct task_struct
*next
,
2578 struct perf_cpu_context
*cpuctx
;
2580 unsigned long flags
;
2585 local_irq_save(flags
);
2589 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2590 if (pmu
->sched_task
) {
2591 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2593 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2595 perf_pmu_disable(pmu
);
2597 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2599 perf_pmu_enable(pmu
);
2601 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2607 local_irq_restore(flags
);
2610 static void perf_event_switch(struct task_struct
*task
,
2611 struct task_struct
*next_prev
, bool sched_in
);
2613 #define for_each_task_context_nr(ctxn) \
2614 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2617 * Called from scheduler to remove the events of the current task,
2618 * with interrupts disabled.
2620 * We stop each event and update the event value in event->count.
2622 * This does not protect us against NMI, but disable()
2623 * sets the disabled bit in the control field of event _before_
2624 * accessing the event control register. If a NMI hits, then it will
2625 * not restart the event.
2627 void __perf_event_task_sched_out(struct task_struct
*task
,
2628 struct task_struct
*next
)
2632 if (__this_cpu_read(perf_sched_cb_usages
))
2633 perf_pmu_sched_task(task
, next
, false);
2635 if (atomic_read(&nr_switch_events
))
2636 perf_event_switch(task
, next
, false);
2638 for_each_task_context_nr(ctxn
)
2639 perf_event_context_sched_out(task
, ctxn
, next
);
2642 * if cgroup events exist on this CPU, then we need
2643 * to check if we have to switch out PMU state.
2644 * cgroup event are system-wide mode only
2646 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2647 perf_cgroup_sched_out(task
, next
);
2650 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2651 struct perf_event_context
*ctx
)
2653 if (!cpuctx
->task_ctx
)
2656 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2659 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2663 * Called with IRQs disabled
2665 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2666 enum event_type_t event_type
)
2668 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2672 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2673 struct perf_cpu_context
*cpuctx
)
2675 struct perf_event
*event
;
2677 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2678 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2680 if (!event_filter_match(event
))
2683 /* may need to reset tstamp_enabled */
2684 if (is_cgroup_event(event
))
2685 perf_cgroup_mark_enabled(event
, ctx
);
2687 if (group_can_go_on(event
, cpuctx
, 1))
2688 group_sched_in(event
, cpuctx
, ctx
);
2691 * If this pinned group hasn't been scheduled,
2692 * put it in error state.
2694 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2695 update_group_times(event
);
2696 event
->state
= PERF_EVENT_STATE_ERROR
;
2702 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2703 struct perf_cpu_context
*cpuctx
)
2705 struct perf_event
*event
;
2708 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2709 /* Ignore events in OFF or ERROR state */
2710 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2713 * Listen to the 'cpu' scheduling filter constraint
2716 if (!event_filter_match(event
))
2719 /* may need to reset tstamp_enabled */
2720 if (is_cgroup_event(event
))
2721 perf_cgroup_mark_enabled(event
, ctx
);
2723 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2724 if (group_sched_in(event
, cpuctx
, ctx
))
2731 ctx_sched_in(struct perf_event_context
*ctx
,
2732 struct perf_cpu_context
*cpuctx
,
2733 enum event_type_t event_type
,
2734 struct task_struct
*task
)
2736 int is_active
= ctx
->is_active
;
2739 lockdep_assert_held(&ctx
->lock
);
2741 if (likely(!ctx
->nr_events
))
2744 ctx
->is_active
|= event_type
;
2747 cpuctx
->task_ctx
= ctx
;
2749 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2753 ctx
->timestamp
= now
;
2754 perf_cgroup_set_timestamp(task
, ctx
);
2756 * First go through the list and put on any pinned groups
2757 * in order to give them the best chance of going on.
2759 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2760 ctx_pinned_sched_in(ctx
, cpuctx
);
2762 /* Then walk through the lower prio flexible groups */
2763 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2764 ctx_flexible_sched_in(ctx
, cpuctx
);
2767 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2768 enum event_type_t event_type
,
2769 struct task_struct
*task
)
2771 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2773 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2776 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2777 struct task_struct
*task
)
2779 struct perf_cpu_context
*cpuctx
;
2781 cpuctx
= __get_cpu_context(ctx
);
2782 if (cpuctx
->task_ctx
== ctx
)
2785 perf_ctx_lock(cpuctx
, ctx
);
2786 perf_pmu_disable(ctx
->pmu
);
2788 * We want to keep the following priority order:
2789 * cpu pinned (that don't need to move), task pinned,
2790 * cpu flexible, task flexible.
2792 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2793 perf_event_sched_in(cpuctx
, ctx
, task
);
2794 perf_pmu_enable(ctx
->pmu
);
2795 perf_ctx_unlock(cpuctx
, ctx
);
2799 * Called from scheduler to add the events of the current task
2800 * with interrupts disabled.
2802 * We restore the event value and then enable it.
2804 * This does not protect us against NMI, but enable()
2805 * sets the enabled bit in the control field of event _before_
2806 * accessing the event control register. If a NMI hits, then it will
2807 * keep the event running.
2809 void __perf_event_task_sched_in(struct task_struct
*prev
,
2810 struct task_struct
*task
)
2812 struct perf_event_context
*ctx
;
2816 * If cgroup events exist on this CPU, then we need to check if we have
2817 * to switch in PMU state; cgroup event are system-wide mode only.
2819 * Since cgroup events are CPU events, we must schedule these in before
2820 * we schedule in the task events.
2822 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2823 perf_cgroup_sched_in(prev
, task
);
2825 for_each_task_context_nr(ctxn
) {
2826 ctx
= task
->perf_event_ctxp
[ctxn
];
2830 perf_event_context_sched_in(ctx
, task
);
2833 if (atomic_read(&nr_switch_events
))
2834 perf_event_switch(task
, prev
, true);
2836 if (__this_cpu_read(perf_sched_cb_usages
))
2837 perf_pmu_sched_task(prev
, task
, true);
2840 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2842 u64 frequency
= event
->attr
.sample_freq
;
2843 u64 sec
= NSEC_PER_SEC
;
2844 u64 divisor
, dividend
;
2846 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2848 count_fls
= fls64(count
);
2849 nsec_fls
= fls64(nsec
);
2850 frequency_fls
= fls64(frequency
);
2854 * We got @count in @nsec, with a target of sample_freq HZ
2855 * the target period becomes:
2858 * period = -------------------
2859 * @nsec * sample_freq
2864 * Reduce accuracy by one bit such that @a and @b converge
2865 * to a similar magnitude.
2867 #define REDUCE_FLS(a, b) \
2869 if (a##_fls > b##_fls) { \
2879 * Reduce accuracy until either term fits in a u64, then proceed with
2880 * the other, so that finally we can do a u64/u64 division.
2882 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2883 REDUCE_FLS(nsec
, frequency
);
2884 REDUCE_FLS(sec
, count
);
2887 if (count_fls
+ sec_fls
> 64) {
2888 divisor
= nsec
* frequency
;
2890 while (count_fls
+ sec_fls
> 64) {
2891 REDUCE_FLS(count
, sec
);
2895 dividend
= count
* sec
;
2897 dividend
= count
* sec
;
2899 while (nsec_fls
+ frequency_fls
> 64) {
2900 REDUCE_FLS(nsec
, frequency
);
2904 divisor
= nsec
* frequency
;
2910 return div64_u64(dividend
, divisor
);
2913 static DEFINE_PER_CPU(int, perf_throttled_count
);
2914 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2916 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2918 struct hw_perf_event
*hwc
= &event
->hw
;
2919 s64 period
, sample_period
;
2922 period
= perf_calculate_period(event
, nsec
, count
);
2924 delta
= (s64
)(period
- hwc
->sample_period
);
2925 delta
= (delta
+ 7) / 8; /* low pass filter */
2927 sample_period
= hwc
->sample_period
+ delta
;
2932 hwc
->sample_period
= sample_period
;
2934 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2936 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2938 local64_set(&hwc
->period_left
, 0);
2941 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2946 * combine freq adjustment with unthrottling to avoid two passes over the
2947 * events. At the same time, make sure, having freq events does not change
2948 * the rate of unthrottling as that would introduce bias.
2950 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2953 struct perf_event
*event
;
2954 struct hw_perf_event
*hwc
;
2955 u64 now
, period
= TICK_NSEC
;
2959 * only need to iterate over all events iff:
2960 * - context have events in frequency mode (needs freq adjust)
2961 * - there are events to unthrottle on this cpu
2963 if (!(ctx
->nr_freq
|| needs_unthr
))
2966 raw_spin_lock(&ctx
->lock
);
2967 perf_pmu_disable(ctx
->pmu
);
2969 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2970 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2973 if (!event_filter_match(event
))
2976 perf_pmu_disable(event
->pmu
);
2980 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
2981 hwc
->interrupts
= 0;
2982 perf_log_throttle(event
, 1);
2983 event
->pmu
->start(event
, 0);
2986 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2990 * stop the event and update event->count
2992 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2994 now
= local64_read(&event
->count
);
2995 delta
= now
- hwc
->freq_count_stamp
;
2996 hwc
->freq_count_stamp
= now
;
3000 * reload only if value has changed
3001 * we have stopped the event so tell that
3002 * to perf_adjust_period() to avoid stopping it
3006 perf_adjust_period(event
, period
, delta
, false);
3008 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3010 perf_pmu_enable(event
->pmu
);
3013 perf_pmu_enable(ctx
->pmu
);
3014 raw_spin_unlock(&ctx
->lock
);
3018 * Round-robin a context's events:
3020 static void rotate_ctx(struct perf_event_context
*ctx
)
3023 * Rotate the first entry last of non-pinned groups. Rotation might be
3024 * disabled by the inheritance code.
3026 if (!ctx
->rotate_disable
)
3027 list_rotate_left(&ctx
->flexible_groups
);
3030 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3032 struct perf_event_context
*ctx
= NULL
;
3035 if (cpuctx
->ctx
.nr_events
) {
3036 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3040 ctx
= cpuctx
->task_ctx
;
3041 if (ctx
&& ctx
->nr_events
) {
3042 if (ctx
->nr_events
!= ctx
->nr_active
)
3049 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3050 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3052 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3054 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3056 rotate_ctx(&cpuctx
->ctx
);
3060 perf_event_sched_in(cpuctx
, ctx
, current
);
3062 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3063 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3069 #ifdef CONFIG_NO_HZ_FULL
3070 bool perf_event_can_stop_tick(void)
3072 if (atomic_read(&nr_freq_events
) ||
3073 __this_cpu_read(perf_throttled_count
))
3080 void perf_event_task_tick(void)
3082 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3083 struct perf_event_context
*ctx
, *tmp
;
3086 WARN_ON(!irqs_disabled());
3088 __this_cpu_inc(perf_throttled_seq
);
3089 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3091 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3092 perf_adjust_freq_unthr_context(ctx
, throttled
);
3095 static int event_enable_on_exec(struct perf_event
*event
,
3096 struct perf_event_context
*ctx
)
3098 if (!event
->attr
.enable_on_exec
)
3101 event
->attr
.enable_on_exec
= 0;
3102 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3105 __perf_event_mark_enabled(event
);
3111 * Enable all of a task's events that have been marked enable-on-exec.
3112 * This expects task == current.
3114 static void perf_event_enable_on_exec(int ctxn
)
3116 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3117 struct perf_cpu_context
*cpuctx
;
3118 struct perf_event
*event
;
3119 unsigned long flags
;
3122 local_irq_save(flags
);
3123 ctx
= current
->perf_event_ctxp
[ctxn
];
3124 if (!ctx
|| !ctx
->nr_events
)
3127 cpuctx
= __get_cpu_context(ctx
);
3128 perf_ctx_lock(cpuctx
, ctx
);
3129 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
3130 enabled
|= event_enable_on_exec(event
, ctx
);
3133 * Unclone and reschedule this context if we enabled any event.
3136 clone_ctx
= unclone_ctx(ctx
);
3137 ctx_resched(cpuctx
, ctx
);
3139 perf_ctx_unlock(cpuctx
, ctx
);
3142 local_irq_restore(flags
);
3148 void perf_event_exec(void)
3153 for_each_task_context_nr(ctxn
)
3154 perf_event_enable_on_exec(ctxn
);
3158 struct perf_read_data
{
3159 struct perf_event
*event
;
3165 * Cross CPU call to read the hardware event
3167 static void __perf_event_read(void *info
)
3169 struct perf_read_data
*data
= info
;
3170 struct perf_event
*sub
, *event
= data
->event
;
3171 struct perf_event_context
*ctx
= event
->ctx
;
3172 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3173 struct pmu
*pmu
= event
->pmu
;
3176 * If this is a task context, we need to check whether it is
3177 * the current task context of this cpu. If not it has been
3178 * scheduled out before the smp call arrived. In that case
3179 * event->count would have been updated to a recent sample
3180 * when the event was scheduled out.
3182 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3185 raw_spin_lock(&ctx
->lock
);
3186 if (ctx
->is_active
) {
3187 update_context_time(ctx
);
3188 update_cgrp_time_from_event(event
);
3191 update_event_times(event
);
3192 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3201 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3205 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3206 update_event_times(sub
);
3207 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3209 * Use sibling's PMU rather than @event's since
3210 * sibling could be on different (eg: software) PMU.
3212 sub
->pmu
->read(sub
);
3216 data
->ret
= pmu
->commit_txn(pmu
);
3219 raw_spin_unlock(&ctx
->lock
);
3222 static inline u64
perf_event_count(struct perf_event
*event
)
3224 if (event
->pmu
->count
)
3225 return event
->pmu
->count(event
);
3227 return __perf_event_count(event
);
3231 * NMI-safe method to read a local event, that is an event that
3233 * - either for the current task, or for this CPU
3234 * - does not have inherit set, for inherited task events
3235 * will not be local and we cannot read them atomically
3236 * - must not have a pmu::count method
3238 u64
perf_event_read_local(struct perf_event
*event
)
3240 unsigned long flags
;
3244 * Disabling interrupts avoids all counter scheduling (context
3245 * switches, timer based rotation and IPIs).
3247 local_irq_save(flags
);
3249 /* If this is a per-task event, it must be for current */
3250 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3251 event
->hw
.target
!= current
);
3253 /* If this is a per-CPU event, it must be for this CPU */
3254 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3255 event
->cpu
!= smp_processor_id());
3258 * It must not be an event with inherit set, we cannot read
3259 * all child counters from atomic context.
3261 WARN_ON_ONCE(event
->attr
.inherit
);
3264 * It must not have a pmu::count method, those are not
3267 WARN_ON_ONCE(event
->pmu
->count
);
3270 * If the event is currently on this CPU, its either a per-task event,
3271 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3274 if (event
->oncpu
== smp_processor_id())
3275 event
->pmu
->read(event
);
3277 val
= local64_read(&event
->count
);
3278 local_irq_restore(flags
);
3283 static int perf_event_read(struct perf_event
*event
, bool group
)
3288 * If event is enabled and currently active on a CPU, update the
3289 * value in the event structure:
3291 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3292 struct perf_read_data data
= {
3297 smp_call_function_single(event
->oncpu
,
3298 __perf_event_read
, &data
, 1);
3300 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3301 struct perf_event_context
*ctx
= event
->ctx
;
3302 unsigned long flags
;
3304 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3306 * may read while context is not active
3307 * (e.g., thread is blocked), in that case
3308 * we cannot update context time
3310 if (ctx
->is_active
) {
3311 update_context_time(ctx
);
3312 update_cgrp_time_from_event(event
);
3315 update_group_times(event
);
3317 update_event_times(event
);
3318 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3325 * Initialize the perf_event context in a task_struct:
3327 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3329 raw_spin_lock_init(&ctx
->lock
);
3330 mutex_init(&ctx
->mutex
);
3331 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3332 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3333 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3334 INIT_LIST_HEAD(&ctx
->event_list
);
3335 atomic_set(&ctx
->refcount
, 1);
3336 INIT_DELAYED_WORK(&ctx
->orphans_remove
, orphans_remove_work
);
3339 static struct perf_event_context
*
3340 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3342 struct perf_event_context
*ctx
;
3344 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3348 __perf_event_init_context(ctx
);
3351 get_task_struct(task
);
3358 static struct task_struct
*
3359 find_lively_task_by_vpid(pid_t vpid
)
3361 struct task_struct
*task
;
3368 task
= find_task_by_vpid(vpid
);
3370 get_task_struct(task
);
3374 return ERR_PTR(-ESRCH
);
3376 /* Reuse ptrace permission checks for now. */
3378 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3383 put_task_struct(task
);
3384 return ERR_PTR(err
);
3389 * Returns a matching context with refcount and pincount.
3391 static struct perf_event_context
*
3392 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3393 struct perf_event
*event
)
3395 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3396 struct perf_cpu_context
*cpuctx
;
3397 void *task_ctx_data
= NULL
;
3398 unsigned long flags
;
3400 int cpu
= event
->cpu
;
3403 /* Must be root to operate on a CPU event: */
3404 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3405 return ERR_PTR(-EACCES
);
3408 * We could be clever and allow to attach a event to an
3409 * offline CPU and activate it when the CPU comes up, but
3412 if (!cpu_online(cpu
))
3413 return ERR_PTR(-ENODEV
);
3415 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3424 ctxn
= pmu
->task_ctx_nr
;
3428 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3429 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3430 if (!task_ctx_data
) {
3437 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3439 clone_ctx
= unclone_ctx(ctx
);
3442 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3443 ctx
->task_ctx_data
= task_ctx_data
;
3444 task_ctx_data
= NULL
;
3446 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3451 ctx
= alloc_perf_context(pmu
, task
);
3456 if (task_ctx_data
) {
3457 ctx
->task_ctx_data
= task_ctx_data
;
3458 task_ctx_data
= NULL
;
3462 mutex_lock(&task
->perf_event_mutex
);
3464 * If it has already passed perf_event_exit_task().
3465 * we must see PF_EXITING, it takes this mutex too.
3467 if (task
->flags
& PF_EXITING
)
3469 else if (task
->perf_event_ctxp
[ctxn
])
3474 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3476 mutex_unlock(&task
->perf_event_mutex
);
3478 if (unlikely(err
)) {
3487 kfree(task_ctx_data
);
3491 kfree(task_ctx_data
);
3492 return ERR_PTR(err
);
3495 static void perf_event_free_filter(struct perf_event
*event
);
3496 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3498 static void free_event_rcu(struct rcu_head
*head
)
3500 struct perf_event
*event
;
3502 event
= container_of(head
, struct perf_event
, rcu_head
);
3504 put_pid_ns(event
->ns
);
3505 perf_event_free_filter(event
);
3509 static void ring_buffer_attach(struct perf_event
*event
,
3510 struct ring_buffer
*rb
);
3512 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3517 if (is_cgroup_event(event
))
3518 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3521 static void unaccount_event(struct perf_event
*event
)
3528 if (event
->attach_state
& PERF_ATTACH_TASK
)
3530 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3531 atomic_dec(&nr_mmap_events
);
3532 if (event
->attr
.comm
)
3533 atomic_dec(&nr_comm_events
);
3534 if (event
->attr
.task
)
3535 atomic_dec(&nr_task_events
);
3536 if (event
->attr
.freq
)
3537 atomic_dec(&nr_freq_events
);
3538 if (event
->attr
.context_switch
) {
3540 atomic_dec(&nr_switch_events
);
3542 if (is_cgroup_event(event
))
3544 if (has_branch_stack(event
))
3548 static_key_slow_dec_deferred(&perf_sched_events
);
3550 unaccount_event_cpu(event
, event
->cpu
);
3554 * The following implement mutual exclusion of events on "exclusive" pmus
3555 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3556 * at a time, so we disallow creating events that might conflict, namely:
3558 * 1) cpu-wide events in the presence of per-task events,
3559 * 2) per-task events in the presence of cpu-wide events,
3560 * 3) two matching events on the same context.
3562 * The former two cases are handled in the allocation path (perf_event_alloc(),
3563 * __free_event()), the latter -- before the first perf_install_in_context().
3565 static int exclusive_event_init(struct perf_event
*event
)
3567 struct pmu
*pmu
= event
->pmu
;
3569 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3573 * Prevent co-existence of per-task and cpu-wide events on the
3574 * same exclusive pmu.
3576 * Negative pmu::exclusive_cnt means there are cpu-wide
3577 * events on this "exclusive" pmu, positive means there are
3580 * Since this is called in perf_event_alloc() path, event::ctx
3581 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3582 * to mean "per-task event", because unlike other attach states it
3583 * never gets cleared.
3585 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3586 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3589 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3596 static void exclusive_event_destroy(struct perf_event
*event
)
3598 struct pmu
*pmu
= event
->pmu
;
3600 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3603 /* see comment in exclusive_event_init() */
3604 if (event
->attach_state
& PERF_ATTACH_TASK
)
3605 atomic_dec(&pmu
->exclusive_cnt
);
3607 atomic_inc(&pmu
->exclusive_cnt
);
3610 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3612 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3613 (e1
->cpu
== e2
->cpu
||
3620 /* Called under the same ctx::mutex as perf_install_in_context() */
3621 static bool exclusive_event_installable(struct perf_event
*event
,
3622 struct perf_event_context
*ctx
)
3624 struct perf_event
*iter_event
;
3625 struct pmu
*pmu
= event
->pmu
;
3627 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3630 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3631 if (exclusive_event_match(iter_event
, event
))
3638 static void __free_event(struct perf_event
*event
)
3640 if (!event
->parent
) {
3641 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3642 put_callchain_buffers();
3645 perf_event_free_bpf_prog(event
);
3648 event
->destroy(event
);
3651 put_ctx(event
->ctx
);
3654 exclusive_event_destroy(event
);
3655 module_put(event
->pmu
->module
);
3658 call_rcu(&event
->rcu_head
, free_event_rcu
);
3661 static void _free_event(struct perf_event
*event
)
3663 irq_work_sync(&event
->pending
);
3665 unaccount_event(event
);
3669 * Can happen when we close an event with re-directed output.
3671 * Since we have a 0 refcount, perf_mmap_close() will skip
3672 * over us; possibly making our ring_buffer_put() the last.
3674 mutex_lock(&event
->mmap_mutex
);
3675 ring_buffer_attach(event
, NULL
);
3676 mutex_unlock(&event
->mmap_mutex
);
3679 if (is_cgroup_event(event
))
3680 perf_detach_cgroup(event
);
3682 __free_event(event
);
3686 * Used to free events which have a known refcount of 1, such as in error paths
3687 * where the event isn't exposed yet and inherited events.
3689 static void free_event(struct perf_event
*event
)
3691 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3692 "unexpected event refcount: %ld; ptr=%p\n",
3693 atomic_long_read(&event
->refcount
), event
)) {
3694 /* leak to avoid use-after-free */
3702 * Remove user event from the owner task.
3704 static void perf_remove_from_owner(struct perf_event
*event
)
3706 struct task_struct
*owner
;
3709 owner
= ACCESS_ONCE(event
->owner
);
3711 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3712 * !owner it means the list deletion is complete and we can indeed
3713 * free this event, otherwise we need to serialize on
3714 * owner->perf_event_mutex.
3716 smp_read_barrier_depends();
3719 * Since delayed_put_task_struct() also drops the last
3720 * task reference we can safely take a new reference
3721 * while holding the rcu_read_lock().
3723 get_task_struct(owner
);
3729 * If we're here through perf_event_exit_task() we're already
3730 * holding ctx->mutex which would be an inversion wrt. the
3731 * normal lock order.
3733 * However we can safely take this lock because its the child
3736 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3739 * We have to re-check the event->owner field, if it is cleared
3740 * we raced with perf_event_exit_task(), acquiring the mutex
3741 * ensured they're done, and we can proceed with freeing the
3745 list_del_init(&event
->owner_entry
);
3746 mutex_unlock(&owner
->perf_event_mutex
);
3747 put_task_struct(owner
);
3751 static void put_event(struct perf_event
*event
)
3753 struct perf_event_context
*ctx
;
3755 if (!atomic_long_dec_and_test(&event
->refcount
))
3758 if (!is_kernel_event(event
))
3759 perf_remove_from_owner(event
);
3762 * There are two ways this annotation is useful:
3764 * 1) there is a lock recursion from perf_event_exit_task
3765 * see the comment there.
3767 * 2) there is a lock-inversion with mmap_sem through
3768 * perf_read_group(), which takes faults while
3769 * holding ctx->mutex, however this is called after
3770 * the last filedesc died, so there is no possibility
3771 * to trigger the AB-BA case.
3773 ctx
= perf_event_ctx_lock_nested(event
, SINGLE_DEPTH_NESTING
);
3774 WARN_ON_ONCE(ctx
->parent_ctx
);
3775 perf_remove_from_context(event
, true);
3776 perf_event_ctx_unlock(event
, ctx
);
3781 int perf_event_release_kernel(struct perf_event
*event
)
3786 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3789 * Called when the last reference to the file is gone.
3791 static int perf_release(struct inode
*inode
, struct file
*file
)
3793 put_event(file
->private_data
);
3798 * Remove all orphanes events from the context.
3800 static void orphans_remove_work(struct work_struct
*work
)
3802 struct perf_event_context
*ctx
;
3803 struct perf_event
*event
, *tmp
;
3805 ctx
= container_of(work
, struct perf_event_context
,
3806 orphans_remove
.work
);
3808 mutex_lock(&ctx
->mutex
);
3809 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
) {
3810 struct perf_event
*parent_event
= event
->parent
;
3812 if (!is_orphaned_child(event
))
3815 perf_remove_from_context(event
, true);
3817 mutex_lock(&parent_event
->child_mutex
);
3818 list_del_init(&event
->child_list
);
3819 mutex_unlock(&parent_event
->child_mutex
);
3822 put_event(parent_event
);
3825 raw_spin_lock_irq(&ctx
->lock
);
3826 ctx
->orphans_remove_sched
= false;
3827 raw_spin_unlock_irq(&ctx
->lock
);
3828 mutex_unlock(&ctx
->mutex
);
3833 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3835 struct perf_event
*child
;
3841 mutex_lock(&event
->child_mutex
);
3843 (void)perf_event_read(event
, false);
3844 total
+= perf_event_count(event
);
3846 *enabled
+= event
->total_time_enabled
+
3847 atomic64_read(&event
->child_total_time_enabled
);
3848 *running
+= event
->total_time_running
+
3849 atomic64_read(&event
->child_total_time_running
);
3851 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3852 (void)perf_event_read(child
, false);
3853 total
+= perf_event_count(child
);
3854 *enabled
+= child
->total_time_enabled
;
3855 *running
+= child
->total_time_running
;
3857 mutex_unlock(&event
->child_mutex
);
3861 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3863 static int __perf_read_group_add(struct perf_event
*leader
,
3864 u64 read_format
, u64
*values
)
3866 struct perf_event
*sub
;
3867 int n
= 1; /* skip @nr */
3870 ret
= perf_event_read(leader
, true);
3875 * Since we co-schedule groups, {enabled,running} times of siblings
3876 * will be identical to those of the leader, so we only publish one
3879 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3880 values
[n
++] += leader
->total_time_enabled
+
3881 atomic64_read(&leader
->child_total_time_enabled
);
3884 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3885 values
[n
++] += leader
->total_time_running
+
3886 atomic64_read(&leader
->child_total_time_running
);
3890 * Write {count,id} tuples for every sibling.
3892 values
[n
++] += perf_event_count(leader
);
3893 if (read_format
& PERF_FORMAT_ID
)
3894 values
[n
++] = primary_event_id(leader
);
3896 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3897 values
[n
++] += perf_event_count(sub
);
3898 if (read_format
& PERF_FORMAT_ID
)
3899 values
[n
++] = primary_event_id(sub
);
3905 static int perf_read_group(struct perf_event
*event
,
3906 u64 read_format
, char __user
*buf
)
3908 struct perf_event
*leader
= event
->group_leader
, *child
;
3909 struct perf_event_context
*ctx
= leader
->ctx
;
3913 lockdep_assert_held(&ctx
->mutex
);
3915 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
3919 values
[0] = 1 + leader
->nr_siblings
;
3922 * By locking the child_mutex of the leader we effectively
3923 * lock the child list of all siblings.. XXX explain how.
3925 mutex_lock(&leader
->child_mutex
);
3927 ret
= __perf_read_group_add(leader
, read_format
, values
);
3931 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
3932 ret
= __perf_read_group_add(child
, read_format
, values
);
3937 mutex_unlock(&leader
->child_mutex
);
3939 ret
= event
->read_size
;
3940 if (copy_to_user(buf
, values
, event
->read_size
))
3945 mutex_unlock(&leader
->child_mutex
);
3951 static int perf_read_one(struct perf_event
*event
,
3952 u64 read_format
, char __user
*buf
)
3954 u64 enabled
, running
;
3958 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3959 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3960 values
[n
++] = enabled
;
3961 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3962 values
[n
++] = running
;
3963 if (read_format
& PERF_FORMAT_ID
)
3964 values
[n
++] = primary_event_id(event
);
3966 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3969 return n
* sizeof(u64
);
3972 static bool is_event_hup(struct perf_event
*event
)
3976 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
3979 mutex_lock(&event
->child_mutex
);
3980 no_children
= list_empty(&event
->child_list
);
3981 mutex_unlock(&event
->child_mutex
);
3986 * Read the performance event - simple non blocking version for now
3989 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
3991 u64 read_format
= event
->attr
.read_format
;
3995 * Return end-of-file for a read on a event that is in
3996 * error state (i.e. because it was pinned but it couldn't be
3997 * scheduled on to the CPU at some point).
3999 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4002 if (count
< event
->read_size
)
4005 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4006 if (read_format
& PERF_FORMAT_GROUP
)
4007 ret
= perf_read_group(event
, read_format
, buf
);
4009 ret
= perf_read_one(event
, read_format
, buf
);
4015 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4017 struct perf_event
*event
= file
->private_data
;
4018 struct perf_event_context
*ctx
;
4021 ctx
= perf_event_ctx_lock(event
);
4022 ret
= __perf_read(event
, buf
, count
);
4023 perf_event_ctx_unlock(event
, ctx
);
4028 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4030 struct perf_event
*event
= file
->private_data
;
4031 struct ring_buffer
*rb
;
4032 unsigned int events
= POLLHUP
;
4034 poll_wait(file
, &event
->waitq
, wait
);
4036 if (is_event_hup(event
))
4040 * Pin the event->rb by taking event->mmap_mutex; otherwise
4041 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4043 mutex_lock(&event
->mmap_mutex
);
4046 events
= atomic_xchg(&rb
->poll
, 0);
4047 mutex_unlock(&event
->mmap_mutex
);
4051 static void _perf_event_reset(struct perf_event
*event
)
4053 (void)perf_event_read(event
, false);
4054 local64_set(&event
->count
, 0);
4055 perf_event_update_userpage(event
);
4059 * Holding the top-level event's child_mutex means that any
4060 * descendant process that has inherited this event will block
4061 * in sync_child_event if it goes to exit, thus satisfying the
4062 * task existence requirements of perf_event_enable/disable.
4064 static void perf_event_for_each_child(struct perf_event
*event
,
4065 void (*func
)(struct perf_event
*))
4067 struct perf_event
*child
;
4069 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4071 mutex_lock(&event
->child_mutex
);
4073 list_for_each_entry(child
, &event
->child_list
, child_list
)
4075 mutex_unlock(&event
->child_mutex
);
4078 static void perf_event_for_each(struct perf_event
*event
,
4079 void (*func
)(struct perf_event
*))
4081 struct perf_event_context
*ctx
= event
->ctx
;
4082 struct perf_event
*sibling
;
4084 lockdep_assert_held(&ctx
->mutex
);
4086 event
= event
->group_leader
;
4088 perf_event_for_each_child(event
, func
);
4089 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4090 perf_event_for_each_child(sibling
, func
);
4093 static void __perf_event_period(struct perf_event
*event
,
4094 struct perf_cpu_context
*cpuctx
,
4095 struct perf_event_context
*ctx
,
4098 u64 value
= *((u64
*)info
);
4101 if (event
->attr
.freq
) {
4102 event
->attr
.sample_freq
= value
;
4104 event
->attr
.sample_period
= value
;
4105 event
->hw
.sample_period
= value
;
4108 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4110 perf_pmu_disable(ctx
->pmu
);
4111 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4114 local64_set(&event
->hw
.period_left
, 0);
4117 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4118 perf_pmu_enable(ctx
->pmu
);
4122 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4126 if (!is_sampling_event(event
))
4129 if (copy_from_user(&value
, arg
, sizeof(value
)))
4135 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4138 event_function_call(event
, __perf_event_period
, &value
);
4143 static const struct file_operations perf_fops
;
4145 static inline int perf_fget_light(int fd
, struct fd
*p
)
4147 struct fd f
= fdget(fd
);
4151 if (f
.file
->f_op
!= &perf_fops
) {
4159 static int perf_event_set_output(struct perf_event
*event
,
4160 struct perf_event
*output_event
);
4161 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4162 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4164 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4166 void (*func
)(struct perf_event
*);
4170 case PERF_EVENT_IOC_ENABLE
:
4171 func
= _perf_event_enable
;
4173 case PERF_EVENT_IOC_DISABLE
:
4174 func
= _perf_event_disable
;
4176 case PERF_EVENT_IOC_RESET
:
4177 func
= _perf_event_reset
;
4180 case PERF_EVENT_IOC_REFRESH
:
4181 return _perf_event_refresh(event
, arg
);
4183 case PERF_EVENT_IOC_PERIOD
:
4184 return perf_event_period(event
, (u64 __user
*)arg
);
4186 case PERF_EVENT_IOC_ID
:
4188 u64 id
= primary_event_id(event
);
4190 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4195 case PERF_EVENT_IOC_SET_OUTPUT
:
4199 struct perf_event
*output_event
;
4201 ret
= perf_fget_light(arg
, &output
);
4204 output_event
= output
.file
->private_data
;
4205 ret
= perf_event_set_output(event
, output_event
);
4208 ret
= perf_event_set_output(event
, NULL
);
4213 case PERF_EVENT_IOC_SET_FILTER
:
4214 return perf_event_set_filter(event
, (void __user
*)arg
);
4216 case PERF_EVENT_IOC_SET_BPF
:
4217 return perf_event_set_bpf_prog(event
, arg
);
4223 if (flags
& PERF_IOC_FLAG_GROUP
)
4224 perf_event_for_each(event
, func
);
4226 perf_event_for_each_child(event
, func
);
4231 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4233 struct perf_event
*event
= file
->private_data
;
4234 struct perf_event_context
*ctx
;
4237 ctx
= perf_event_ctx_lock(event
);
4238 ret
= _perf_ioctl(event
, cmd
, arg
);
4239 perf_event_ctx_unlock(event
, ctx
);
4244 #ifdef CONFIG_COMPAT
4245 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4248 switch (_IOC_NR(cmd
)) {
4249 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4250 case _IOC_NR(PERF_EVENT_IOC_ID
):
4251 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4252 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4253 cmd
&= ~IOCSIZE_MASK
;
4254 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4258 return perf_ioctl(file
, cmd
, arg
);
4261 # define perf_compat_ioctl NULL
4264 int perf_event_task_enable(void)
4266 struct perf_event_context
*ctx
;
4267 struct perf_event
*event
;
4269 mutex_lock(¤t
->perf_event_mutex
);
4270 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4271 ctx
= perf_event_ctx_lock(event
);
4272 perf_event_for_each_child(event
, _perf_event_enable
);
4273 perf_event_ctx_unlock(event
, ctx
);
4275 mutex_unlock(¤t
->perf_event_mutex
);
4280 int perf_event_task_disable(void)
4282 struct perf_event_context
*ctx
;
4283 struct perf_event
*event
;
4285 mutex_lock(¤t
->perf_event_mutex
);
4286 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4287 ctx
= perf_event_ctx_lock(event
);
4288 perf_event_for_each_child(event
, _perf_event_disable
);
4289 perf_event_ctx_unlock(event
, ctx
);
4291 mutex_unlock(¤t
->perf_event_mutex
);
4296 static int perf_event_index(struct perf_event
*event
)
4298 if (event
->hw
.state
& PERF_HES_STOPPED
)
4301 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4304 return event
->pmu
->event_idx(event
);
4307 static void calc_timer_values(struct perf_event
*event
,
4314 *now
= perf_clock();
4315 ctx_time
= event
->shadow_ctx_time
+ *now
;
4316 *enabled
= ctx_time
- event
->tstamp_enabled
;
4317 *running
= ctx_time
- event
->tstamp_running
;
4320 static void perf_event_init_userpage(struct perf_event
*event
)
4322 struct perf_event_mmap_page
*userpg
;
4323 struct ring_buffer
*rb
;
4326 rb
= rcu_dereference(event
->rb
);
4330 userpg
= rb
->user_page
;
4332 /* Allow new userspace to detect that bit 0 is deprecated */
4333 userpg
->cap_bit0_is_deprecated
= 1;
4334 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4335 userpg
->data_offset
= PAGE_SIZE
;
4336 userpg
->data_size
= perf_data_size(rb
);
4342 void __weak
arch_perf_update_userpage(
4343 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4348 * Callers need to ensure there can be no nesting of this function, otherwise
4349 * the seqlock logic goes bad. We can not serialize this because the arch
4350 * code calls this from NMI context.
4352 void perf_event_update_userpage(struct perf_event
*event
)
4354 struct perf_event_mmap_page
*userpg
;
4355 struct ring_buffer
*rb
;
4356 u64 enabled
, running
, now
;
4359 rb
= rcu_dereference(event
->rb
);
4364 * compute total_time_enabled, total_time_running
4365 * based on snapshot values taken when the event
4366 * was last scheduled in.
4368 * we cannot simply called update_context_time()
4369 * because of locking issue as we can be called in
4372 calc_timer_values(event
, &now
, &enabled
, &running
);
4374 userpg
= rb
->user_page
;
4376 * Disable preemption so as to not let the corresponding user-space
4377 * spin too long if we get preempted.
4382 userpg
->index
= perf_event_index(event
);
4383 userpg
->offset
= perf_event_count(event
);
4385 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4387 userpg
->time_enabled
= enabled
+
4388 atomic64_read(&event
->child_total_time_enabled
);
4390 userpg
->time_running
= running
+
4391 atomic64_read(&event
->child_total_time_running
);
4393 arch_perf_update_userpage(event
, userpg
, now
);
4402 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4404 struct perf_event
*event
= vma
->vm_file
->private_data
;
4405 struct ring_buffer
*rb
;
4406 int ret
= VM_FAULT_SIGBUS
;
4408 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4409 if (vmf
->pgoff
== 0)
4415 rb
= rcu_dereference(event
->rb
);
4419 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4422 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4426 get_page(vmf
->page
);
4427 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4428 vmf
->page
->index
= vmf
->pgoff
;
4437 static void ring_buffer_attach(struct perf_event
*event
,
4438 struct ring_buffer
*rb
)
4440 struct ring_buffer
*old_rb
= NULL
;
4441 unsigned long flags
;
4445 * Should be impossible, we set this when removing
4446 * event->rb_entry and wait/clear when adding event->rb_entry.
4448 WARN_ON_ONCE(event
->rcu_pending
);
4451 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4452 list_del_rcu(&event
->rb_entry
);
4453 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4455 event
->rcu_batches
= get_state_synchronize_rcu();
4456 event
->rcu_pending
= 1;
4460 if (event
->rcu_pending
) {
4461 cond_synchronize_rcu(event
->rcu_batches
);
4462 event
->rcu_pending
= 0;
4465 spin_lock_irqsave(&rb
->event_lock
, flags
);
4466 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4467 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4470 rcu_assign_pointer(event
->rb
, rb
);
4473 ring_buffer_put(old_rb
);
4475 * Since we detached before setting the new rb, so that we
4476 * could attach the new rb, we could have missed a wakeup.
4479 wake_up_all(&event
->waitq
);
4483 static void ring_buffer_wakeup(struct perf_event
*event
)
4485 struct ring_buffer
*rb
;
4488 rb
= rcu_dereference(event
->rb
);
4490 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4491 wake_up_all(&event
->waitq
);
4496 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4498 struct ring_buffer
*rb
;
4501 rb
= rcu_dereference(event
->rb
);
4503 if (!atomic_inc_not_zero(&rb
->refcount
))
4511 void ring_buffer_put(struct ring_buffer
*rb
)
4513 if (!atomic_dec_and_test(&rb
->refcount
))
4516 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4518 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4521 static void perf_mmap_open(struct vm_area_struct
*vma
)
4523 struct perf_event
*event
= vma
->vm_file
->private_data
;
4525 atomic_inc(&event
->mmap_count
);
4526 atomic_inc(&event
->rb
->mmap_count
);
4529 atomic_inc(&event
->rb
->aux_mmap_count
);
4531 if (event
->pmu
->event_mapped
)
4532 event
->pmu
->event_mapped(event
);
4536 * A buffer can be mmap()ed multiple times; either directly through the same
4537 * event, or through other events by use of perf_event_set_output().
4539 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4540 * the buffer here, where we still have a VM context. This means we need
4541 * to detach all events redirecting to us.
4543 static void perf_mmap_close(struct vm_area_struct
*vma
)
4545 struct perf_event
*event
= vma
->vm_file
->private_data
;
4547 struct ring_buffer
*rb
= ring_buffer_get(event
);
4548 struct user_struct
*mmap_user
= rb
->mmap_user
;
4549 int mmap_locked
= rb
->mmap_locked
;
4550 unsigned long size
= perf_data_size(rb
);
4552 if (event
->pmu
->event_unmapped
)
4553 event
->pmu
->event_unmapped(event
);
4556 * rb->aux_mmap_count will always drop before rb->mmap_count and
4557 * event->mmap_count, so it is ok to use event->mmap_mutex to
4558 * serialize with perf_mmap here.
4560 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4561 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4562 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4563 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4566 mutex_unlock(&event
->mmap_mutex
);
4569 atomic_dec(&rb
->mmap_count
);
4571 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4574 ring_buffer_attach(event
, NULL
);
4575 mutex_unlock(&event
->mmap_mutex
);
4577 /* If there's still other mmap()s of this buffer, we're done. */
4578 if (atomic_read(&rb
->mmap_count
))
4582 * No other mmap()s, detach from all other events that might redirect
4583 * into the now unreachable buffer. Somewhat complicated by the
4584 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4588 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4589 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4591 * This event is en-route to free_event() which will
4592 * detach it and remove it from the list.
4598 mutex_lock(&event
->mmap_mutex
);
4600 * Check we didn't race with perf_event_set_output() which can
4601 * swizzle the rb from under us while we were waiting to
4602 * acquire mmap_mutex.
4604 * If we find a different rb; ignore this event, a next
4605 * iteration will no longer find it on the list. We have to
4606 * still restart the iteration to make sure we're not now
4607 * iterating the wrong list.
4609 if (event
->rb
== rb
)
4610 ring_buffer_attach(event
, NULL
);
4612 mutex_unlock(&event
->mmap_mutex
);
4616 * Restart the iteration; either we're on the wrong list or
4617 * destroyed its integrity by doing a deletion.
4624 * It could be there's still a few 0-ref events on the list; they'll
4625 * get cleaned up by free_event() -- they'll also still have their
4626 * ref on the rb and will free it whenever they are done with it.
4628 * Aside from that, this buffer is 'fully' detached and unmapped,
4629 * undo the VM accounting.
4632 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4633 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4634 free_uid(mmap_user
);
4637 ring_buffer_put(rb
); /* could be last */
4640 static const struct vm_operations_struct perf_mmap_vmops
= {
4641 .open
= perf_mmap_open
,
4642 .close
= perf_mmap_close
, /* non mergable */
4643 .fault
= perf_mmap_fault
,
4644 .page_mkwrite
= perf_mmap_fault
,
4647 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4649 struct perf_event
*event
= file
->private_data
;
4650 unsigned long user_locked
, user_lock_limit
;
4651 struct user_struct
*user
= current_user();
4652 unsigned long locked
, lock_limit
;
4653 struct ring_buffer
*rb
= NULL
;
4654 unsigned long vma_size
;
4655 unsigned long nr_pages
;
4656 long user_extra
= 0, extra
= 0;
4657 int ret
= 0, flags
= 0;
4660 * Don't allow mmap() of inherited per-task counters. This would
4661 * create a performance issue due to all children writing to the
4664 if (event
->cpu
== -1 && event
->attr
.inherit
)
4667 if (!(vma
->vm_flags
& VM_SHARED
))
4670 vma_size
= vma
->vm_end
- vma
->vm_start
;
4672 if (vma
->vm_pgoff
== 0) {
4673 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4676 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4677 * mapped, all subsequent mappings should have the same size
4678 * and offset. Must be above the normal perf buffer.
4680 u64 aux_offset
, aux_size
;
4685 nr_pages
= vma_size
/ PAGE_SIZE
;
4687 mutex_lock(&event
->mmap_mutex
);
4694 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4695 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4697 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4700 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4703 /* already mapped with a different offset */
4704 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4707 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4710 /* already mapped with a different size */
4711 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4714 if (!is_power_of_2(nr_pages
))
4717 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4720 if (rb_has_aux(rb
)) {
4721 atomic_inc(&rb
->aux_mmap_count
);
4726 atomic_set(&rb
->aux_mmap_count
, 1);
4727 user_extra
= nr_pages
;
4733 * If we have rb pages ensure they're a power-of-two number, so we
4734 * can do bitmasks instead of modulo.
4736 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4739 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4742 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4744 mutex_lock(&event
->mmap_mutex
);
4746 if (event
->rb
->nr_pages
!= nr_pages
) {
4751 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4753 * Raced against perf_mmap_close() through
4754 * perf_event_set_output(). Try again, hope for better
4757 mutex_unlock(&event
->mmap_mutex
);
4764 user_extra
= nr_pages
+ 1;
4767 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4770 * Increase the limit linearly with more CPUs:
4772 user_lock_limit
*= num_online_cpus();
4774 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4776 if (user_locked
> user_lock_limit
)
4777 extra
= user_locked
- user_lock_limit
;
4779 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4780 lock_limit
>>= PAGE_SHIFT
;
4781 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4783 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4784 !capable(CAP_IPC_LOCK
)) {
4789 WARN_ON(!rb
&& event
->rb
);
4791 if (vma
->vm_flags
& VM_WRITE
)
4792 flags
|= RING_BUFFER_WRITABLE
;
4795 rb
= rb_alloc(nr_pages
,
4796 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4804 atomic_set(&rb
->mmap_count
, 1);
4805 rb
->mmap_user
= get_current_user();
4806 rb
->mmap_locked
= extra
;
4808 ring_buffer_attach(event
, rb
);
4810 perf_event_init_userpage(event
);
4811 perf_event_update_userpage(event
);
4813 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4814 event
->attr
.aux_watermark
, flags
);
4816 rb
->aux_mmap_locked
= extra
;
4821 atomic_long_add(user_extra
, &user
->locked_vm
);
4822 vma
->vm_mm
->pinned_vm
+= extra
;
4824 atomic_inc(&event
->mmap_count
);
4826 atomic_dec(&rb
->mmap_count
);
4829 mutex_unlock(&event
->mmap_mutex
);
4832 * Since pinned accounting is per vm we cannot allow fork() to copy our
4835 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4836 vma
->vm_ops
= &perf_mmap_vmops
;
4838 if (event
->pmu
->event_mapped
)
4839 event
->pmu
->event_mapped(event
);
4844 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4846 struct inode
*inode
= file_inode(filp
);
4847 struct perf_event
*event
= filp
->private_data
;
4850 mutex_lock(&inode
->i_mutex
);
4851 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4852 mutex_unlock(&inode
->i_mutex
);
4860 static const struct file_operations perf_fops
= {
4861 .llseek
= no_llseek
,
4862 .release
= perf_release
,
4865 .unlocked_ioctl
= perf_ioctl
,
4866 .compat_ioctl
= perf_compat_ioctl
,
4868 .fasync
= perf_fasync
,
4874 * If there's data, ensure we set the poll() state and publish everything
4875 * to user-space before waking everybody up.
4878 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
4880 /* only the parent has fasync state */
4882 event
= event
->parent
;
4883 return &event
->fasync
;
4886 void perf_event_wakeup(struct perf_event
*event
)
4888 ring_buffer_wakeup(event
);
4890 if (event
->pending_kill
) {
4891 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
4892 event
->pending_kill
= 0;
4896 static void perf_pending_event(struct irq_work
*entry
)
4898 struct perf_event
*event
= container_of(entry
,
4899 struct perf_event
, pending
);
4902 rctx
= perf_swevent_get_recursion_context();
4904 * If we 'fail' here, that's OK, it means recursion is already disabled
4905 * and we won't recurse 'further'.
4908 if (event
->pending_disable
) {
4909 event
->pending_disable
= 0;
4910 perf_event_disable_local(event
);
4913 if (event
->pending_wakeup
) {
4914 event
->pending_wakeup
= 0;
4915 perf_event_wakeup(event
);
4919 perf_swevent_put_recursion_context(rctx
);
4923 * We assume there is only KVM supporting the callbacks.
4924 * Later on, we might change it to a list if there is
4925 * another virtualization implementation supporting the callbacks.
4927 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4929 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4931 perf_guest_cbs
= cbs
;
4934 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4936 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4938 perf_guest_cbs
= NULL
;
4941 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4944 perf_output_sample_regs(struct perf_output_handle
*handle
,
4945 struct pt_regs
*regs
, u64 mask
)
4949 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4950 sizeof(mask
) * BITS_PER_BYTE
) {
4953 val
= perf_reg_value(regs
, bit
);
4954 perf_output_put(handle
, val
);
4958 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
4959 struct pt_regs
*regs
,
4960 struct pt_regs
*regs_user_copy
)
4962 if (user_mode(regs
)) {
4963 regs_user
->abi
= perf_reg_abi(current
);
4964 regs_user
->regs
= regs
;
4965 } else if (current
->mm
) {
4966 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
4968 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
4969 regs_user
->regs
= NULL
;
4973 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
4974 struct pt_regs
*regs
)
4976 regs_intr
->regs
= regs
;
4977 regs_intr
->abi
= perf_reg_abi(current
);
4982 * Get remaining task size from user stack pointer.
4984 * It'd be better to take stack vma map and limit this more
4985 * precisly, but there's no way to get it safely under interrupt,
4986 * so using TASK_SIZE as limit.
4988 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
4990 unsigned long addr
= perf_user_stack_pointer(regs
);
4992 if (!addr
|| addr
>= TASK_SIZE
)
4995 return TASK_SIZE
- addr
;
4999 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5000 struct pt_regs
*regs
)
5004 /* No regs, no stack pointer, no dump. */
5009 * Check if we fit in with the requested stack size into the:
5011 * If we don't, we limit the size to the TASK_SIZE.
5013 * - remaining sample size
5014 * If we don't, we customize the stack size to
5015 * fit in to the remaining sample size.
5018 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5019 stack_size
= min(stack_size
, (u16
) task_size
);
5021 /* Current header size plus static size and dynamic size. */
5022 header_size
+= 2 * sizeof(u64
);
5024 /* Do we fit in with the current stack dump size? */
5025 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5027 * If we overflow the maximum size for the sample,
5028 * we customize the stack dump size to fit in.
5030 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5031 stack_size
= round_up(stack_size
, sizeof(u64
));
5038 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5039 struct pt_regs
*regs
)
5041 /* Case of a kernel thread, nothing to dump */
5044 perf_output_put(handle
, size
);
5053 * - the size requested by user or the best one we can fit
5054 * in to the sample max size
5056 * - user stack dump data
5058 * - the actual dumped size
5062 perf_output_put(handle
, dump_size
);
5065 sp
= perf_user_stack_pointer(regs
);
5066 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5067 dyn_size
= dump_size
- rem
;
5069 perf_output_skip(handle
, rem
);
5072 perf_output_put(handle
, dyn_size
);
5076 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5077 struct perf_sample_data
*data
,
5078 struct perf_event
*event
)
5080 u64 sample_type
= event
->attr
.sample_type
;
5082 data
->type
= sample_type
;
5083 header
->size
+= event
->id_header_size
;
5085 if (sample_type
& PERF_SAMPLE_TID
) {
5086 /* namespace issues */
5087 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5088 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5091 if (sample_type
& PERF_SAMPLE_TIME
)
5092 data
->time
= perf_event_clock(event
);
5094 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5095 data
->id
= primary_event_id(event
);
5097 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5098 data
->stream_id
= event
->id
;
5100 if (sample_type
& PERF_SAMPLE_CPU
) {
5101 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5102 data
->cpu_entry
.reserved
= 0;
5106 void perf_event_header__init_id(struct perf_event_header
*header
,
5107 struct perf_sample_data
*data
,
5108 struct perf_event
*event
)
5110 if (event
->attr
.sample_id_all
)
5111 __perf_event_header__init_id(header
, data
, event
);
5114 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5115 struct perf_sample_data
*data
)
5117 u64 sample_type
= data
->type
;
5119 if (sample_type
& PERF_SAMPLE_TID
)
5120 perf_output_put(handle
, data
->tid_entry
);
5122 if (sample_type
& PERF_SAMPLE_TIME
)
5123 perf_output_put(handle
, data
->time
);
5125 if (sample_type
& PERF_SAMPLE_ID
)
5126 perf_output_put(handle
, data
->id
);
5128 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5129 perf_output_put(handle
, data
->stream_id
);
5131 if (sample_type
& PERF_SAMPLE_CPU
)
5132 perf_output_put(handle
, data
->cpu_entry
);
5134 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5135 perf_output_put(handle
, data
->id
);
5138 void perf_event__output_id_sample(struct perf_event
*event
,
5139 struct perf_output_handle
*handle
,
5140 struct perf_sample_data
*sample
)
5142 if (event
->attr
.sample_id_all
)
5143 __perf_event__output_id_sample(handle
, sample
);
5146 static void perf_output_read_one(struct perf_output_handle
*handle
,
5147 struct perf_event
*event
,
5148 u64 enabled
, u64 running
)
5150 u64 read_format
= event
->attr
.read_format
;
5154 values
[n
++] = perf_event_count(event
);
5155 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5156 values
[n
++] = enabled
+
5157 atomic64_read(&event
->child_total_time_enabled
);
5159 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5160 values
[n
++] = running
+
5161 atomic64_read(&event
->child_total_time_running
);
5163 if (read_format
& PERF_FORMAT_ID
)
5164 values
[n
++] = primary_event_id(event
);
5166 __output_copy(handle
, values
, n
* sizeof(u64
));
5170 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5172 static void perf_output_read_group(struct perf_output_handle
*handle
,
5173 struct perf_event
*event
,
5174 u64 enabled
, u64 running
)
5176 struct perf_event
*leader
= event
->group_leader
, *sub
;
5177 u64 read_format
= event
->attr
.read_format
;
5181 values
[n
++] = 1 + leader
->nr_siblings
;
5183 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5184 values
[n
++] = enabled
;
5186 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5187 values
[n
++] = running
;
5189 if (leader
!= event
)
5190 leader
->pmu
->read(leader
);
5192 values
[n
++] = perf_event_count(leader
);
5193 if (read_format
& PERF_FORMAT_ID
)
5194 values
[n
++] = primary_event_id(leader
);
5196 __output_copy(handle
, values
, n
* sizeof(u64
));
5198 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5201 if ((sub
!= event
) &&
5202 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5203 sub
->pmu
->read(sub
);
5205 values
[n
++] = perf_event_count(sub
);
5206 if (read_format
& PERF_FORMAT_ID
)
5207 values
[n
++] = primary_event_id(sub
);
5209 __output_copy(handle
, values
, n
* sizeof(u64
));
5213 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5214 PERF_FORMAT_TOTAL_TIME_RUNNING)
5216 static void perf_output_read(struct perf_output_handle
*handle
,
5217 struct perf_event
*event
)
5219 u64 enabled
= 0, running
= 0, now
;
5220 u64 read_format
= event
->attr
.read_format
;
5223 * compute total_time_enabled, total_time_running
5224 * based on snapshot values taken when the event
5225 * was last scheduled in.
5227 * we cannot simply called update_context_time()
5228 * because of locking issue as we are called in
5231 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5232 calc_timer_values(event
, &now
, &enabled
, &running
);
5234 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5235 perf_output_read_group(handle
, event
, enabled
, running
);
5237 perf_output_read_one(handle
, event
, enabled
, running
);
5240 void perf_output_sample(struct perf_output_handle
*handle
,
5241 struct perf_event_header
*header
,
5242 struct perf_sample_data
*data
,
5243 struct perf_event
*event
)
5245 u64 sample_type
= data
->type
;
5247 perf_output_put(handle
, *header
);
5249 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5250 perf_output_put(handle
, data
->id
);
5252 if (sample_type
& PERF_SAMPLE_IP
)
5253 perf_output_put(handle
, data
->ip
);
5255 if (sample_type
& PERF_SAMPLE_TID
)
5256 perf_output_put(handle
, data
->tid_entry
);
5258 if (sample_type
& PERF_SAMPLE_TIME
)
5259 perf_output_put(handle
, data
->time
);
5261 if (sample_type
& PERF_SAMPLE_ADDR
)
5262 perf_output_put(handle
, data
->addr
);
5264 if (sample_type
& PERF_SAMPLE_ID
)
5265 perf_output_put(handle
, data
->id
);
5267 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5268 perf_output_put(handle
, data
->stream_id
);
5270 if (sample_type
& PERF_SAMPLE_CPU
)
5271 perf_output_put(handle
, data
->cpu_entry
);
5273 if (sample_type
& PERF_SAMPLE_PERIOD
)
5274 perf_output_put(handle
, data
->period
);
5276 if (sample_type
& PERF_SAMPLE_READ
)
5277 perf_output_read(handle
, event
);
5279 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5280 if (data
->callchain
) {
5283 if (data
->callchain
)
5284 size
+= data
->callchain
->nr
;
5286 size
*= sizeof(u64
);
5288 __output_copy(handle
, data
->callchain
, size
);
5291 perf_output_put(handle
, nr
);
5295 if (sample_type
& PERF_SAMPLE_RAW
) {
5297 u32 raw_size
= data
->raw
->size
;
5298 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5299 sizeof(u64
)) - sizeof(u32
);
5302 perf_output_put(handle
, real_size
);
5303 __output_copy(handle
, data
->raw
->data
, raw_size
);
5304 if (real_size
- raw_size
)
5305 __output_copy(handle
, &zero
, real_size
- raw_size
);
5311 .size
= sizeof(u32
),
5314 perf_output_put(handle
, raw
);
5318 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5319 if (data
->br_stack
) {
5322 size
= data
->br_stack
->nr
5323 * sizeof(struct perf_branch_entry
);
5325 perf_output_put(handle
, data
->br_stack
->nr
);
5326 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5329 * we always store at least the value of nr
5332 perf_output_put(handle
, nr
);
5336 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5337 u64 abi
= data
->regs_user
.abi
;
5340 * If there are no regs to dump, notice it through
5341 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5343 perf_output_put(handle
, abi
);
5346 u64 mask
= event
->attr
.sample_regs_user
;
5347 perf_output_sample_regs(handle
,
5348 data
->regs_user
.regs
,
5353 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5354 perf_output_sample_ustack(handle
,
5355 data
->stack_user_size
,
5356 data
->regs_user
.regs
);
5359 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5360 perf_output_put(handle
, data
->weight
);
5362 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5363 perf_output_put(handle
, data
->data_src
.val
);
5365 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5366 perf_output_put(handle
, data
->txn
);
5368 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5369 u64 abi
= data
->regs_intr
.abi
;
5371 * If there are no regs to dump, notice it through
5372 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5374 perf_output_put(handle
, abi
);
5377 u64 mask
= event
->attr
.sample_regs_intr
;
5379 perf_output_sample_regs(handle
,
5380 data
->regs_intr
.regs
,
5385 if (!event
->attr
.watermark
) {
5386 int wakeup_events
= event
->attr
.wakeup_events
;
5388 if (wakeup_events
) {
5389 struct ring_buffer
*rb
= handle
->rb
;
5390 int events
= local_inc_return(&rb
->events
);
5392 if (events
>= wakeup_events
) {
5393 local_sub(wakeup_events
, &rb
->events
);
5394 local_inc(&rb
->wakeup
);
5400 void perf_prepare_sample(struct perf_event_header
*header
,
5401 struct perf_sample_data
*data
,
5402 struct perf_event
*event
,
5403 struct pt_regs
*regs
)
5405 u64 sample_type
= event
->attr
.sample_type
;
5407 header
->type
= PERF_RECORD_SAMPLE
;
5408 header
->size
= sizeof(*header
) + event
->header_size
;
5411 header
->misc
|= perf_misc_flags(regs
);
5413 __perf_event_header__init_id(header
, data
, event
);
5415 if (sample_type
& PERF_SAMPLE_IP
)
5416 data
->ip
= perf_instruction_pointer(regs
);
5418 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5421 data
->callchain
= perf_callchain(event
, regs
);
5423 if (data
->callchain
)
5424 size
+= data
->callchain
->nr
;
5426 header
->size
+= size
* sizeof(u64
);
5429 if (sample_type
& PERF_SAMPLE_RAW
) {
5430 int size
= sizeof(u32
);
5433 size
+= data
->raw
->size
;
5435 size
+= sizeof(u32
);
5437 header
->size
+= round_up(size
, sizeof(u64
));
5440 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5441 int size
= sizeof(u64
); /* nr */
5442 if (data
->br_stack
) {
5443 size
+= data
->br_stack
->nr
5444 * sizeof(struct perf_branch_entry
);
5446 header
->size
+= size
;
5449 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5450 perf_sample_regs_user(&data
->regs_user
, regs
,
5451 &data
->regs_user_copy
);
5453 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5454 /* regs dump ABI info */
5455 int size
= sizeof(u64
);
5457 if (data
->regs_user
.regs
) {
5458 u64 mask
= event
->attr
.sample_regs_user
;
5459 size
+= hweight64(mask
) * sizeof(u64
);
5462 header
->size
+= size
;
5465 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5467 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5468 * processed as the last one or have additional check added
5469 * in case new sample type is added, because we could eat
5470 * up the rest of the sample size.
5472 u16 stack_size
= event
->attr
.sample_stack_user
;
5473 u16 size
= sizeof(u64
);
5475 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5476 data
->regs_user
.regs
);
5479 * If there is something to dump, add space for the dump
5480 * itself and for the field that tells the dynamic size,
5481 * which is how many have been actually dumped.
5484 size
+= sizeof(u64
) + stack_size
;
5486 data
->stack_user_size
= stack_size
;
5487 header
->size
+= size
;
5490 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5491 /* regs dump ABI info */
5492 int size
= sizeof(u64
);
5494 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5496 if (data
->regs_intr
.regs
) {
5497 u64 mask
= event
->attr
.sample_regs_intr
;
5499 size
+= hweight64(mask
) * sizeof(u64
);
5502 header
->size
+= size
;
5506 void perf_event_output(struct perf_event
*event
,
5507 struct perf_sample_data
*data
,
5508 struct pt_regs
*regs
)
5510 struct perf_output_handle handle
;
5511 struct perf_event_header header
;
5513 /* protect the callchain buffers */
5516 perf_prepare_sample(&header
, data
, event
, regs
);
5518 if (perf_output_begin(&handle
, event
, header
.size
))
5521 perf_output_sample(&handle
, &header
, data
, event
);
5523 perf_output_end(&handle
);
5533 struct perf_read_event
{
5534 struct perf_event_header header
;
5541 perf_event_read_event(struct perf_event
*event
,
5542 struct task_struct
*task
)
5544 struct perf_output_handle handle
;
5545 struct perf_sample_data sample
;
5546 struct perf_read_event read_event
= {
5548 .type
= PERF_RECORD_READ
,
5550 .size
= sizeof(read_event
) + event
->read_size
,
5552 .pid
= perf_event_pid(event
, task
),
5553 .tid
= perf_event_tid(event
, task
),
5557 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5558 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5562 perf_output_put(&handle
, read_event
);
5563 perf_output_read(&handle
, event
);
5564 perf_event__output_id_sample(event
, &handle
, &sample
);
5566 perf_output_end(&handle
);
5569 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5572 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5573 perf_event_aux_output_cb output
,
5576 struct perf_event
*event
;
5578 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5579 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5581 if (!event_filter_match(event
))
5583 output(event
, data
);
5588 perf_event_aux_task_ctx(perf_event_aux_output_cb output
, void *data
,
5589 struct perf_event_context
*task_ctx
)
5593 perf_event_aux_ctx(task_ctx
, output
, data
);
5599 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5600 struct perf_event_context
*task_ctx
)
5602 struct perf_cpu_context
*cpuctx
;
5603 struct perf_event_context
*ctx
;
5608 * If we have task_ctx != NULL we only notify
5609 * the task context itself. The task_ctx is set
5610 * only for EXIT events before releasing task
5614 perf_event_aux_task_ctx(output
, data
, task_ctx
);
5619 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5620 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5621 if (cpuctx
->unique_pmu
!= pmu
)
5623 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5624 ctxn
= pmu
->task_ctx_nr
;
5627 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5629 perf_event_aux_ctx(ctx
, output
, data
);
5631 put_cpu_ptr(pmu
->pmu_cpu_context
);
5637 * task tracking -- fork/exit
5639 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5642 struct perf_task_event
{
5643 struct task_struct
*task
;
5644 struct perf_event_context
*task_ctx
;
5647 struct perf_event_header header
;
5657 static int perf_event_task_match(struct perf_event
*event
)
5659 return event
->attr
.comm
|| event
->attr
.mmap
||
5660 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5664 static void perf_event_task_output(struct perf_event
*event
,
5667 struct perf_task_event
*task_event
= data
;
5668 struct perf_output_handle handle
;
5669 struct perf_sample_data sample
;
5670 struct task_struct
*task
= task_event
->task
;
5671 int ret
, size
= task_event
->event_id
.header
.size
;
5673 if (!perf_event_task_match(event
))
5676 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5678 ret
= perf_output_begin(&handle
, event
,
5679 task_event
->event_id
.header
.size
);
5683 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5684 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5686 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5687 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5689 task_event
->event_id
.time
= perf_event_clock(event
);
5691 perf_output_put(&handle
, task_event
->event_id
);
5693 perf_event__output_id_sample(event
, &handle
, &sample
);
5695 perf_output_end(&handle
);
5697 task_event
->event_id
.header
.size
= size
;
5700 static void perf_event_task(struct task_struct
*task
,
5701 struct perf_event_context
*task_ctx
,
5704 struct perf_task_event task_event
;
5706 if (!atomic_read(&nr_comm_events
) &&
5707 !atomic_read(&nr_mmap_events
) &&
5708 !atomic_read(&nr_task_events
))
5711 task_event
= (struct perf_task_event
){
5713 .task_ctx
= task_ctx
,
5716 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5718 .size
= sizeof(task_event
.event_id
),
5728 perf_event_aux(perf_event_task_output
,
5733 void perf_event_fork(struct task_struct
*task
)
5735 perf_event_task(task
, NULL
, 1);
5742 struct perf_comm_event
{
5743 struct task_struct
*task
;
5748 struct perf_event_header header
;
5755 static int perf_event_comm_match(struct perf_event
*event
)
5757 return event
->attr
.comm
;
5760 static void perf_event_comm_output(struct perf_event
*event
,
5763 struct perf_comm_event
*comm_event
= data
;
5764 struct perf_output_handle handle
;
5765 struct perf_sample_data sample
;
5766 int size
= comm_event
->event_id
.header
.size
;
5769 if (!perf_event_comm_match(event
))
5772 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5773 ret
= perf_output_begin(&handle
, event
,
5774 comm_event
->event_id
.header
.size
);
5779 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5780 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5782 perf_output_put(&handle
, comm_event
->event_id
);
5783 __output_copy(&handle
, comm_event
->comm
,
5784 comm_event
->comm_size
);
5786 perf_event__output_id_sample(event
, &handle
, &sample
);
5788 perf_output_end(&handle
);
5790 comm_event
->event_id
.header
.size
= size
;
5793 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5795 char comm
[TASK_COMM_LEN
];
5798 memset(comm
, 0, sizeof(comm
));
5799 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5800 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5802 comm_event
->comm
= comm
;
5803 comm_event
->comm_size
= size
;
5805 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5807 perf_event_aux(perf_event_comm_output
,
5812 void perf_event_comm(struct task_struct
*task
, bool exec
)
5814 struct perf_comm_event comm_event
;
5816 if (!atomic_read(&nr_comm_events
))
5819 comm_event
= (struct perf_comm_event
){
5825 .type
= PERF_RECORD_COMM
,
5826 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5834 perf_event_comm_event(&comm_event
);
5841 struct perf_mmap_event
{
5842 struct vm_area_struct
*vma
;
5844 const char *file_name
;
5852 struct perf_event_header header
;
5862 static int perf_event_mmap_match(struct perf_event
*event
,
5865 struct perf_mmap_event
*mmap_event
= data
;
5866 struct vm_area_struct
*vma
= mmap_event
->vma
;
5867 int executable
= vma
->vm_flags
& VM_EXEC
;
5869 return (!executable
&& event
->attr
.mmap_data
) ||
5870 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5873 static void perf_event_mmap_output(struct perf_event
*event
,
5876 struct perf_mmap_event
*mmap_event
= data
;
5877 struct perf_output_handle handle
;
5878 struct perf_sample_data sample
;
5879 int size
= mmap_event
->event_id
.header
.size
;
5882 if (!perf_event_mmap_match(event
, data
))
5885 if (event
->attr
.mmap2
) {
5886 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5887 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5888 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5889 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5890 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5891 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5892 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5895 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5896 ret
= perf_output_begin(&handle
, event
,
5897 mmap_event
->event_id
.header
.size
);
5901 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5902 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5904 perf_output_put(&handle
, mmap_event
->event_id
);
5906 if (event
->attr
.mmap2
) {
5907 perf_output_put(&handle
, mmap_event
->maj
);
5908 perf_output_put(&handle
, mmap_event
->min
);
5909 perf_output_put(&handle
, mmap_event
->ino
);
5910 perf_output_put(&handle
, mmap_event
->ino_generation
);
5911 perf_output_put(&handle
, mmap_event
->prot
);
5912 perf_output_put(&handle
, mmap_event
->flags
);
5915 __output_copy(&handle
, mmap_event
->file_name
,
5916 mmap_event
->file_size
);
5918 perf_event__output_id_sample(event
, &handle
, &sample
);
5920 perf_output_end(&handle
);
5922 mmap_event
->event_id
.header
.size
= size
;
5925 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5927 struct vm_area_struct
*vma
= mmap_event
->vma
;
5928 struct file
*file
= vma
->vm_file
;
5929 int maj
= 0, min
= 0;
5930 u64 ino
= 0, gen
= 0;
5931 u32 prot
= 0, flags
= 0;
5938 struct inode
*inode
;
5941 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5947 * d_path() works from the end of the rb backwards, so we
5948 * need to add enough zero bytes after the string to handle
5949 * the 64bit alignment we do later.
5951 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
5956 inode
= file_inode(vma
->vm_file
);
5957 dev
= inode
->i_sb
->s_dev
;
5959 gen
= inode
->i_generation
;
5963 if (vma
->vm_flags
& VM_READ
)
5965 if (vma
->vm_flags
& VM_WRITE
)
5967 if (vma
->vm_flags
& VM_EXEC
)
5970 if (vma
->vm_flags
& VM_MAYSHARE
)
5973 flags
= MAP_PRIVATE
;
5975 if (vma
->vm_flags
& VM_DENYWRITE
)
5976 flags
|= MAP_DENYWRITE
;
5977 if (vma
->vm_flags
& VM_MAYEXEC
)
5978 flags
|= MAP_EXECUTABLE
;
5979 if (vma
->vm_flags
& VM_LOCKED
)
5980 flags
|= MAP_LOCKED
;
5981 if (vma
->vm_flags
& VM_HUGETLB
)
5982 flags
|= MAP_HUGETLB
;
5986 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
5987 name
= (char *) vma
->vm_ops
->name(vma
);
5992 name
= (char *)arch_vma_name(vma
);
5996 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
5997 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6001 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6002 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6012 strlcpy(tmp
, name
, sizeof(tmp
));
6016 * Since our buffer works in 8 byte units we need to align our string
6017 * size to a multiple of 8. However, we must guarantee the tail end is
6018 * zero'd out to avoid leaking random bits to userspace.
6020 size
= strlen(name
)+1;
6021 while (!IS_ALIGNED(size
, sizeof(u64
)))
6022 name
[size
++] = '\0';
6024 mmap_event
->file_name
= name
;
6025 mmap_event
->file_size
= size
;
6026 mmap_event
->maj
= maj
;
6027 mmap_event
->min
= min
;
6028 mmap_event
->ino
= ino
;
6029 mmap_event
->ino_generation
= gen
;
6030 mmap_event
->prot
= prot
;
6031 mmap_event
->flags
= flags
;
6033 if (!(vma
->vm_flags
& VM_EXEC
))
6034 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6036 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6038 perf_event_aux(perf_event_mmap_output
,
6045 void perf_event_mmap(struct vm_area_struct
*vma
)
6047 struct perf_mmap_event mmap_event
;
6049 if (!atomic_read(&nr_mmap_events
))
6052 mmap_event
= (struct perf_mmap_event
){
6058 .type
= PERF_RECORD_MMAP
,
6059 .misc
= PERF_RECORD_MISC_USER
,
6064 .start
= vma
->vm_start
,
6065 .len
= vma
->vm_end
- vma
->vm_start
,
6066 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6068 /* .maj (attr_mmap2 only) */
6069 /* .min (attr_mmap2 only) */
6070 /* .ino (attr_mmap2 only) */
6071 /* .ino_generation (attr_mmap2 only) */
6072 /* .prot (attr_mmap2 only) */
6073 /* .flags (attr_mmap2 only) */
6076 perf_event_mmap_event(&mmap_event
);
6079 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6080 unsigned long size
, u64 flags
)
6082 struct perf_output_handle handle
;
6083 struct perf_sample_data sample
;
6084 struct perf_aux_event
{
6085 struct perf_event_header header
;
6091 .type
= PERF_RECORD_AUX
,
6093 .size
= sizeof(rec
),
6101 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6102 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6107 perf_output_put(&handle
, rec
);
6108 perf_event__output_id_sample(event
, &handle
, &sample
);
6110 perf_output_end(&handle
);
6114 * Lost/dropped samples logging
6116 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6118 struct perf_output_handle handle
;
6119 struct perf_sample_data sample
;
6123 struct perf_event_header header
;
6125 } lost_samples_event
= {
6127 .type
= PERF_RECORD_LOST_SAMPLES
,
6129 .size
= sizeof(lost_samples_event
),
6134 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6136 ret
= perf_output_begin(&handle
, event
,
6137 lost_samples_event
.header
.size
);
6141 perf_output_put(&handle
, lost_samples_event
);
6142 perf_event__output_id_sample(event
, &handle
, &sample
);
6143 perf_output_end(&handle
);
6147 * context_switch tracking
6150 struct perf_switch_event
{
6151 struct task_struct
*task
;
6152 struct task_struct
*next_prev
;
6155 struct perf_event_header header
;
6161 static int perf_event_switch_match(struct perf_event
*event
)
6163 return event
->attr
.context_switch
;
6166 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6168 struct perf_switch_event
*se
= data
;
6169 struct perf_output_handle handle
;
6170 struct perf_sample_data sample
;
6173 if (!perf_event_switch_match(event
))
6176 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6177 if (event
->ctx
->task
) {
6178 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6179 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6181 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6182 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6183 se
->event_id
.next_prev_pid
=
6184 perf_event_pid(event
, se
->next_prev
);
6185 se
->event_id
.next_prev_tid
=
6186 perf_event_tid(event
, se
->next_prev
);
6189 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6191 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6195 if (event
->ctx
->task
)
6196 perf_output_put(&handle
, se
->event_id
.header
);
6198 perf_output_put(&handle
, se
->event_id
);
6200 perf_event__output_id_sample(event
, &handle
, &sample
);
6202 perf_output_end(&handle
);
6205 static void perf_event_switch(struct task_struct
*task
,
6206 struct task_struct
*next_prev
, bool sched_in
)
6208 struct perf_switch_event switch_event
;
6210 /* N.B. caller checks nr_switch_events != 0 */
6212 switch_event
= (struct perf_switch_event
){
6214 .next_prev
= next_prev
,
6218 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6221 /* .next_prev_pid */
6222 /* .next_prev_tid */
6226 perf_event_aux(perf_event_switch_output
,
6232 * IRQ throttle logging
6235 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6237 struct perf_output_handle handle
;
6238 struct perf_sample_data sample
;
6242 struct perf_event_header header
;
6246 } throttle_event
= {
6248 .type
= PERF_RECORD_THROTTLE
,
6250 .size
= sizeof(throttle_event
),
6252 .time
= perf_event_clock(event
),
6253 .id
= primary_event_id(event
),
6254 .stream_id
= event
->id
,
6258 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6260 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6262 ret
= perf_output_begin(&handle
, event
,
6263 throttle_event
.header
.size
);
6267 perf_output_put(&handle
, throttle_event
);
6268 perf_event__output_id_sample(event
, &handle
, &sample
);
6269 perf_output_end(&handle
);
6272 static void perf_log_itrace_start(struct perf_event
*event
)
6274 struct perf_output_handle handle
;
6275 struct perf_sample_data sample
;
6276 struct perf_aux_event
{
6277 struct perf_event_header header
;
6284 event
= event
->parent
;
6286 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6287 event
->hw
.itrace_started
)
6290 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6291 rec
.header
.misc
= 0;
6292 rec
.header
.size
= sizeof(rec
);
6293 rec
.pid
= perf_event_pid(event
, current
);
6294 rec
.tid
= perf_event_tid(event
, current
);
6296 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6297 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6302 perf_output_put(&handle
, rec
);
6303 perf_event__output_id_sample(event
, &handle
, &sample
);
6305 perf_output_end(&handle
);
6309 * Generic event overflow handling, sampling.
6312 static int __perf_event_overflow(struct perf_event
*event
,
6313 int throttle
, struct perf_sample_data
*data
,
6314 struct pt_regs
*regs
)
6316 int events
= atomic_read(&event
->event_limit
);
6317 struct hw_perf_event
*hwc
= &event
->hw
;
6322 * Non-sampling counters might still use the PMI to fold short
6323 * hardware counters, ignore those.
6325 if (unlikely(!is_sampling_event(event
)))
6328 seq
= __this_cpu_read(perf_throttled_seq
);
6329 if (seq
!= hwc
->interrupts_seq
) {
6330 hwc
->interrupts_seq
= seq
;
6331 hwc
->interrupts
= 1;
6334 if (unlikely(throttle
6335 && hwc
->interrupts
>= max_samples_per_tick
)) {
6336 __this_cpu_inc(perf_throttled_count
);
6337 hwc
->interrupts
= MAX_INTERRUPTS
;
6338 perf_log_throttle(event
, 0);
6339 tick_nohz_full_kick();
6344 if (event
->attr
.freq
) {
6345 u64 now
= perf_clock();
6346 s64 delta
= now
- hwc
->freq_time_stamp
;
6348 hwc
->freq_time_stamp
= now
;
6350 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6351 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6355 * XXX event_limit might not quite work as expected on inherited
6359 event
->pending_kill
= POLL_IN
;
6360 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6362 event
->pending_kill
= POLL_HUP
;
6363 event
->pending_disable
= 1;
6364 irq_work_queue(&event
->pending
);
6367 if (event
->overflow_handler
)
6368 event
->overflow_handler(event
, data
, regs
);
6370 perf_event_output(event
, data
, regs
);
6372 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6373 event
->pending_wakeup
= 1;
6374 irq_work_queue(&event
->pending
);
6380 int perf_event_overflow(struct perf_event
*event
,
6381 struct perf_sample_data
*data
,
6382 struct pt_regs
*regs
)
6384 return __perf_event_overflow(event
, 1, data
, regs
);
6388 * Generic software event infrastructure
6391 struct swevent_htable
{
6392 struct swevent_hlist
*swevent_hlist
;
6393 struct mutex hlist_mutex
;
6396 /* Recursion avoidance in each contexts */
6397 int recursion
[PERF_NR_CONTEXTS
];
6400 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6403 * We directly increment event->count and keep a second value in
6404 * event->hw.period_left to count intervals. This period event
6405 * is kept in the range [-sample_period, 0] so that we can use the
6409 u64
perf_swevent_set_period(struct perf_event
*event
)
6411 struct hw_perf_event
*hwc
= &event
->hw
;
6412 u64 period
= hwc
->last_period
;
6416 hwc
->last_period
= hwc
->sample_period
;
6419 old
= val
= local64_read(&hwc
->period_left
);
6423 nr
= div64_u64(period
+ val
, period
);
6424 offset
= nr
* period
;
6426 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6432 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6433 struct perf_sample_data
*data
,
6434 struct pt_regs
*regs
)
6436 struct hw_perf_event
*hwc
= &event
->hw
;
6440 overflow
= perf_swevent_set_period(event
);
6442 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6445 for (; overflow
; overflow
--) {
6446 if (__perf_event_overflow(event
, throttle
,
6449 * We inhibit the overflow from happening when
6450 * hwc->interrupts == MAX_INTERRUPTS.
6458 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6459 struct perf_sample_data
*data
,
6460 struct pt_regs
*regs
)
6462 struct hw_perf_event
*hwc
= &event
->hw
;
6464 local64_add(nr
, &event
->count
);
6469 if (!is_sampling_event(event
))
6472 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6474 return perf_swevent_overflow(event
, 1, data
, regs
);
6476 data
->period
= event
->hw
.last_period
;
6478 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6479 return perf_swevent_overflow(event
, 1, data
, regs
);
6481 if (local64_add_negative(nr
, &hwc
->period_left
))
6484 perf_swevent_overflow(event
, 0, data
, regs
);
6487 static int perf_exclude_event(struct perf_event
*event
,
6488 struct pt_regs
*regs
)
6490 if (event
->hw
.state
& PERF_HES_STOPPED
)
6494 if (event
->attr
.exclude_user
&& user_mode(regs
))
6497 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6504 static int perf_swevent_match(struct perf_event
*event
,
6505 enum perf_type_id type
,
6507 struct perf_sample_data
*data
,
6508 struct pt_regs
*regs
)
6510 if (event
->attr
.type
!= type
)
6513 if (event
->attr
.config
!= event_id
)
6516 if (perf_exclude_event(event
, regs
))
6522 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6524 u64 val
= event_id
| (type
<< 32);
6526 return hash_64(val
, SWEVENT_HLIST_BITS
);
6529 static inline struct hlist_head
*
6530 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6532 u64 hash
= swevent_hash(type
, event_id
);
6534 return &hlist
->heads
[hash
];
6537 /* For the read side: events when they trigger */
6538 static inline struct hlist_head
*
6539 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6541 struct swevent_hlist
*hlist
;
6543 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6547 return __find_swevent_head(hlist
, type
, event_id
);
6550 /* For the event head insertion and removal in the hlist */
6551 static inline struct hlist_head
*
6552 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6554 struct swevent_hlist
*hlist
;
6555 u32 event_id
= event
->attr
.config
;
6556 u64 type
= event
->attr
.type
;
6559 * Event scheduling is always serialized against hlist allocation
6560 * and release. Which makes the protected version suitable here.
6561 * The context lock guarantees that.
6563 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6564 lockdep_is_held(&event
->ctx
->lock
));
6568 return __find_swevent_head(hlist
, type
, event_id
);
6571 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6573 struct perf_sample_data
*data
,
6574 struct pt_regs
*regs
)
6576 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6577 struct perf_event
*event
;
6578 struct hlist_head
*head
;
6581 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6585 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6586 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6587 perf_swevent_event(event
, nr
, data
, regs
);
6593 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6595 int perf_swevent_get_recursion_context(void)
6597 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6599 return get_recursion_context(swhash
->recursion
);
6601 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6603 inline void perf_swevent_put_recursion_context(int rctx
)
6605 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6607 put_recursion_context(swhash
->recursion
, rctx
);
6610 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6612 struct perf_sample_data data
;
6614 if (WARN_ON_ONCE(!regs
))
6617 perf_sample_data_init(&data
, addr
, 0);
6618 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6621 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6625 preempt_disable_notrace();
6626 rctx
= perf_swevent_get_recursion_context();
6627 if (unlikely(rctx
< 0))
6630 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6632 perf_swevent_put_recursion_context(rctx
);
6634 preempt_enable_notrace();
6637 static void perf_swevent_read(struct perf_event
*event
)
6641 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6643 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6644 struct hw_perf_event
*hwc
= &event
->hw
;
6645 struct hlist_head
*head
;
6647 if (is_sampling_event(event
)) {
6648 hwc
->last_period
= hwc
->sample_period
;
6649 perf_swevent_set_period(event
);
6652 hwc
->state
= !(flags
& PERF_EF_START
);
6654 head
= find_swevent_head(swhash
, event
);
6655 if (WARN_ON_ONCE(!head
))
6658 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6659 perf_event_update_userpage(event
);
6664 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6666 hlist_del_rcu(&event
->hlist_entry
);
6669 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6671 event
->hw
.state
= 0;
6674 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6676 event
->hw
.state
= PERF_HES_STOPPED
;
6679 /* Deref the hlist from the update side */
6680 static inline struct swevent_hlist
*
6681 swevent_hlist_deref(struct swevent_htable
*swhash
)
6683 return rcu_dereference_protected(swhash
->swevent_hlist
,
6684 lockdep_is_held(&swhash
->hlist_mutex
));
6687 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6689 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6694 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6695 kfree_rcu(hlist
, rcu_head
);
6698 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6700 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6702 mutex_lock(&swhash
->hlist_mutex
);
6704 if (!--swhash
->hlist_refcount
)
6705 swevent_hlist_release(swhash
);
6707 mutex_unlock(&swhash
->hlist_mutex
);
6710 static void swevent_hlist_put(struct perf_event
*event
)
6714 for_each_possible_cpu(cpu
)
6715 swevent_hlist_put_cpu(event
, cpu
);
6718 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6720 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6723 mutex_lock(&swhash
->hlist_mutex
);
6724 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6725 struct swevent_hlist
*hlist
;
6727 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6732 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6734 swhash
->hlist_refcount
++;
6736 mutex_unlock(&swhash
->hlist_mutex
);
6741 static int swevent_hlist_get(struct perf_event
*event
)
6744 int cpu
, failed_cpu
;
6747 for_each_possible_cpu(cpu
) {
6748 err
= swevent_hlist_get_cpu(event
, cpu
);
6758 for_each_possible_cpu(cpu
) {
6759 if (cpu
== failed_cpu
)
6761 swevent_hlist_put_cpu(event
, cpu
);
6768 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6770 static void sw_perf_event_destroy(struct perf_event
*event
)
6772 u64 event_id
= event
->attr
.config
;
6774 WARN_ON(event
->parent
);
6776 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6777 swevent_hlist_put(event
);
6780 static int perf_swevent_init(struct perf_event
*event
)
6782 u64 event_id
= event
->attr
.config
;
6784 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6788 * no branch sampling for software events
6790 if (has_branch_stack(event
))
6794 case PERF_COUNT_SW_CPU_CLOCK
:
6795 case PERF_COUNT_SW_TASK_CLOCK
:
6802 if (event_id
>= PERF_COUNT_SW_MAX
)
6805 if (!event
->parent
) {
6808 err
= swevent_hlist_get(event
);
6812 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6813 event
->destroy
= sw_perf_event_destroy
;
6819 static struct pmu perf_swevent
= {
6820 .task_ctx_nr
= perf_sw_context
,
6822 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6824 .event_init
= perf_swevent_init
,
6825 .add
= perf_swevent_add
,
6826 .del
= perf_swevent_del
,
6827 .start
= perf_swevent_start
,
6828 .stop
= perf_swevent_stop
,
6829 .read
= perf_swevent_read
,
6832 #ifdef CONFIG_EVENT_TRACING
6834 static int perf_tp_filter_match(struct perf_event
*event
,
6835 struct perf_sample_data
*data
)
6837 void *record
= data
->raw
->data
;
6839 /* only top level events have filters set */
6841 event
= event
->parent
;
6843 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6848 static int perf_tp_event_match(struct perf_event
*event
,
6849 struct perf_sample_data
*data
,
6850 struct pt_regs
*regs
)
6852 if (event
->hw
.state
& PERF_HES_STOPPED
)
6855 * All tracepoints are from kernel-space.
6857 if (event
->attr
.exclude_kernel
)
6860 if (!perf_tp_filter_match(event
, data
))
6866 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6867 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6868 struct task_struct
*task
)
6870 struct perf_sample_data data
;
6871 struct perf_event
*event
;
6873 struct perf_raw_record raw
= {
6878 perf_sample_data_init(&data
, addr
, 0);
6881 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6882 if (perf_tp_event_match(event
, &data
, regs
))
6883 perf_swevent_event(event
, count
, &data
, regs
);
6887 * If we got specified a target task, also iterate its context and
6888 * deliver this event there too.
6890 if (task
&& task
!= current
) {
6891 struct perf_event_context
*ctx
;
6892 struct trace_entry
*entry
= record
;
6895 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6899 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6900 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6902 if (event
->attr
.config
!= entry
->type
)
6904 if (perf_tp_event_match(event
, &data
, regs
))
6905 perf_swevent_event(event
, count
, &data
, regs
);
6911 perf_swevent_put_recursion_context(rctx
);
6913 EXPORT_SYMBOL_GPL(perf_tp_event
);
6915 static void tp_perf_event_destroy(struct perf_event
*event
)
6917 perf_trace_destroy(event
);
6920 static int perf_tp_event_init(struct perf_event
*event
)
6924 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6928 * no branch sampling for tracepoint events
6930 if (has_branch_stack(event
))
6933 err
= perf_trace_init(event
);
6937 event
->destroy
= tp_perf_event_destroy
;
6942 static struct pmu perf_tracepoint
= {
6943 .task_ctx_nr
= perf_sw_context
,
6945 .event_init
= perf_tp_event_init
,
6946 .add
= perf_trace_add
,
6947 .del
= perf_trace_del
,
6948 .start
= perf_swevent_start
,
6949 .stop
= perf_swevent_stop
,
6950 .read
= perf_swevent_read
,
6953 static inline void perf_tp_register(void)
6955 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
6958 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6963 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6966 filter_str
= strndup_user(arg
, PAGE_SIZE
);
6967 if (IS_ERR(filter_str
))
6968 return PTR_ERR(filter_str
);
6970 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
6976 static void perf_event_free_filter(struct perf_event
*event
)
6978 ftrace_profile_free_filter(event
);
6981 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
6983 struct bpf_prog
*prog
;
6985 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6988 if (event
->tp_event
->prog
)
6991 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
6992 /* bpf programs can only be attached to u/kprobes */
6995 prog
= bpf_prog_get(prog_fd
);
6997 return PTR_ERR(prog
);
6999 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7000 /* valid fd, but invalid bpf program type */
7005 event
->tp_event
->prog
= prog
;
7010 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7012 struct bpf_prog
*prog
;
7014 if (!event
->tp_event
)
7017 prog
= event
->tp_event
->prog
;
7019 event
->tp_event
->prog
= NULL
;
7026 static inline void perf_tp_register(void)
7030 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7035 static void perf_event_free_filter(struct perf_event
*event
)
7039 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7044 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7047 #endif /* CONFIG_EVENT_TRACING */
7049 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7050 void perf_bp_event(struct perf_event
*bp
, void *data
)
7052 struct perf_sample_data sample
;
7053 struct pt_regs
*regs
= data
;
7055 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7057 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7058 perf_swevent_event(bp
, 1, &sample
, regs
);
7063 * hrtimer based swevent callback
7066 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7068 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7069 struct perf_sample_data data
;
7070 struct pt_regs
*regs
;
7071 struct perf_event
*event
;
7074 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7076 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7077 return HRTIMER_NORESTART
;
7079 event
->pmu
->read(event
);
7081 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7082 regs
= get_irq_regs();
7084 if (regs
&& !perf_exclude_event(event
, regs
)) {
7085 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7086 if (__perf_event_overflow(event
, 1, &data
, regs
))
7087 ret
= HRTIMER_NORESTART
;
7090 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7091 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7096 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7098 struct hw_perf_event
*hwc
= &event
->hw
;
7101 if (!is_sampling_event(event
))
7104 period
= local64_read(&hwc
->period_left
);
7109 local64_set(&hwc
->period_left
, 0);
7111 period
= max_t(u64
, 10000, hwc
->sample_period
);
7113 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7114 HRTIMER_MODE_REL_PINNED
);
7117 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7119 struct hw_perf_event
*hwc
= &event
->hw
;
7121 if (is_sampling_event(event
)) {
7122 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7123 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7125 hrtimer_cancel(&hwc
->hrtimer
);
7129 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7131 struct hw_perf_event
*hwc
= &event
->hw
;
7133 if (!is_sampling_event(event
))
7136 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7137 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7140 * Since hrtimers have a fixed rate, we can do a static freq->period
7141 * mapping and avoid the whole period adjust feedback stuff.
7143 if (event
->attr
.freq
) {
7144 long freq
= event
->attr
.sample_freq
;
7146 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7147 hwc
->sample_period
= event
->attr
.sample_period
;
7148 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7149 hwc
->last_period
= hwc
->sample_period
;
7150 event
->attr
.freq
= 0;
7155 * Software event: cpu wall time clock
7158 static void cpu_clock_event_update(struct perf_event
*event
)
7163 now
= local_clock();
7164 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7165 local64_add(now
- prev
, &event
->count
);
7168 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7170 local64_set(&event
->hw
.prev_count
, local_clock());
7171 perf_swevent_start_hrtimer(event
);
7174 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7176 perf_swevent_cancel_hrtimer(event
);
7177 cpu_clock_event_update(event
);
7180 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7182 if (flags
& PERF_EF_START
)
7183 cpu_clock_event_start(event
, flags
);
7184 perf_event_update_userpage(event
);
7189 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7191 cpu_clock_event_stop(event
, flags
);
7194 static void cpu_clock_event_read(struct perf_event
*event
)
7196 cpu_clock_event_update(event
);
7199 static int cpu_clock_event_init(struct perf_event
*event
)
7201 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7204 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7208 * no branch sampling for software events
7210 if (has_branch_stack(event
))
7213 perf_swevent_init_hrtimer(event
);
7218 static struct pmu perf_cpu_clock
= {
7219 .task_ctx_nr
= perf_sw_context
,
7221 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7223 .event_init
= cpu_clock_event_init
,
7224 .add
= cpu_clock_event_add
,
7225 .del
= cpu_clock_event_del
,
7226 .start
= cpu_clock_event_start
,
7227 .stop
= cpu_clock_event_stop
,
7228 .read
= cpu_clock_event_read
,
7232 * Software event: task time clock
7235 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7240 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7242 local64_add(delta
, &event
->count
);
7245 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7247 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7248 perf_swevent_start_hrtimer(event
);
7251 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7253 perf_swevent_cancel_hrtimer(event
);
7254 task_clock_event_update(event
, event
->ctx
->time
);
7257 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7259 if (flags
& PERF_EF_START
)
7260 task_clock_event_start(event
, flags
);
7261 perf_event_update_userpage(event
);
7266 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7268 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7271 static void task_clock_event_read(struct perf_event
*event
)
7273 u64 now
= perf_clock();
7274 u64 delta
= now
- event
->ctx
->timestamp
;
7275 u64 time
= event
->ctx
->time
+ delta
;
7277 task_clock_event_update(event
, time
);
7280 static int task_clock_event_init(struct perf_event
*event
)
7282 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7285 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7289 * no branch sampling for software events
7291 if (has_branch_stack(event
))
7294 perf_swevent_init_hrtimer(event
);
7299 static struct pmu perf_task_clock
= {
7300 .task_ctx_nr
= perf_sw_context
,
7302 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7304 .event_init
= task_clock_event_init
,
7305 .add
= task_clock_event_add
,
7306 .del
= task_clock_event_del
,
7307 .start
= task_clock_event_start
,
7308 .stop
= task_clock_event_stop
,
7309 .read
= task_clock_event_read
,
7312 static void perf_pmu_nop_void(struct pmu
*pmu
)
7316 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7320 static int perf_pmu_nop_int(struct pmu
*pmu
)
7325 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7327 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7329 __this_cpu_write(nop_txn_flags
, flags
);
7331 if (flags
& ~PERF_PMU_TXN_ADD
)
7334 perf_pmu_disable(pmu
);
7337 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7339 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7341 __this_cpu_write(nop_txn_flags
, 0);
7343 if (flags
& ~PERF_PMU_TXN_ADD
)
7346 perf_pmu_enable(pmu
);
7350 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7352 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7354 __this_cpu_write(nop_txn_flags
, 0);
7356 if (flags
& ~PERF_PMU_TXN_ADD
)
7359 perf_pmu_enable(pmu
);
7362 static int perf_event_idx_default(struct perf_event
*event
)
7368 * Ensures all contexts with the same task_ctx_nr have the same
7369 * pmu_cpu_context too.
7371 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7378 list_for_each_entry(pmu
, &pmus
, entry
) {
7379 if (pmu
->task_ctx_nr
== ctxn
)
7380 return pmu
->pmu_cpu_context
;
7386 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7390 for_each_possible_cpu(cpu
) {
7391 struct perf_cpu_context
*cpuctx
;
7393 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7395 if (cpuctx
->unique_pmu
== old_pmu
)
7396 cpuctx
->unique_pmu
= pmu
;
7400 static void free_pmu_context(struct pmu
*pmu
)
7404 mutex_lock(&pmus_lock
);
7406 * Like a real lame refcount.
7408 list_for_each_entry(i
, &pmus
, entry
) {
7409 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7410 update_pmu_context(i
, pmu
);
7415 free_percpu(pmu
->pmu_cpu_context
);
7417 mutex_unlock(&pmus_lock
);
7419 static struct idr pmu_idr
;
7422 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7424 struct pmu
*pmu
= dev_get_drvdata(dev
);
7426 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7428 static DEVICE_ATTR_RO(type
);
7431 perf_event_mux_interval_ms_show(struct device
*dev
,
7432 struct device_attribute
*attr
,
7435 struct pmu
*pmu
= dev_get_drvdata(dev
);
7437 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7440 static DEFINE_MUTEX(mux_interval_mutex
);
7443 perf_event_mux_interval_ms_store(struct device
*dev
,
7444 struct device_attribute
*attr
,
7445 const char *buf
, size_t count
)
7447 struct pmu
*pmu
= dev_get_drvdata(dev
);
7448 int timer
, cpu
, ret
;
7450 ret
= kstrtoint(buf
, 0, &timer
);
7457 /* same value, noting to do */
7458 if (timer
== pmu
->hrtimer_interval_ms
)
7461 mutex_lock(&mux_interval_mutex
);
7462 pmu
->hrtimer_interval_ms
= timer
;
7464 /* update all cpuctx for this PMU */
7466 for_each_online_cpu(cpu
) {
7467 struct perf_cpu_context
*cpuctx
;
7468 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7469 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7471 cpu_function_call(cpu
,
7472 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7475 mutex_unlock(&mux_interval_mutex
);
7479 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7481 static struct attribute
*pmu_dev_attrs
[] = {
7482 &dev_attr_type
.attr
,
7483 &dev_attr_perf_event_mux_interval_ms
.attr
,
7486 ATTRIBUTE_GROUPS(pmu_dev
);
7488 static int pmu_bus_running
;
7489 static struct bus_type pmu_bus
= {
7490 .name
= "event_source",
7491 .dev_groups
= pmu_dev_groups
,
7494 static void pmu_dev_release(struct device
*dev
)
7499 static int pmu_dev_alloc(struct pmu
*pmu
)
7503 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7507 pmu
->dev
->groups
= pmu
->attr_groups
;
7508 device_initialize(pmu
->dev
);
7509 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7513 dev_set_drvdata(pmu
->dev
, pmu
);
7514 pmu
->dev
->bus
= &pmu_bus
;
7515 pmu
->dev
->release
= pmu_dev_release
;
7516 ret
= device_add(pmu
->dev
);
7524 put_device(pmu
->dev
);
7528 static struct lock_class_key cpuctx_mutex
;
7529 static struct lock_class_key cpuctx_lock
;
7531 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7535 mutex_lock(&pmus_lock
);
7537 pmu
->pmu_disable_count
= alloc_percpu(int);
7538 if (!pmu
->pmu_disable_count
)
7547 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7555 if (pmu_bus_running
) {
7556 ret
= pmu_dev_alloc(pmu
);
7562 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7563 if (pmu
->pmu_cpu_context
)
7564 goto got_cpu_context
;
7567 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7568 if (!pmu
->pmu_cpu_context
)
7571 for_each_possible_cpu(cpu
) {
7572 struct perf_cpu_context
*cpuctx
;
7574 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7575 __perf_event_init_context(&cpuctx
->ctx
);
7576 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7577 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7578 cpuctx
->ctx
.pmu
= pmu
;
7580 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7582 cpuctx
->unique_pmu
= pmu
;
7586 if (!pmu
->start_txn
) {
7587 if (pmu
->pmu_enable
) {
7589 * If we have pmu_enable/pmu_disable calls, install
7590 * transaction stubs that use that to try and batch
7591 * hardware accesses.
7593 pmu
->start_txn
= perf_pmu_start_txn
;
7594 pmu
->commit_txn
= perf_pmu_commit_txn
;
7595 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7597 pmu
->start_txn
= perf_pmu_nop_txn
;
7598 pmu
->commit_txn
= perf_pmu_nop_int
;
7599 pmu
->cancel_txn
= perf_pmu_nop_void
;
7603 if (!pmu
->pmu_enable
) {
7604 pmu
->pmu_enable
= perf_pmu_nop_void
;
7605 pmu
->pmu_disable
= perf_pmu_nop_void
;
7608 if (!pmu
->event_idx
)
7609 pmu
->event_idx
= perf_event_idx_default
;
7611 list_add_rcu(&pmu
->entry
, &pmus
);
7612 atomic_set(&pmu
->exclusive_cnt
, 0);
7615 mutex_unlock(&pmus_lock
);
7620 device_del(pmu
->dev
);
7621 put_device(pmu
->dev
);
7624 if (pmu
->type
>= PERF_TYPE_MAX
)
7625 idr_remove(&pmu_idr
, pmu
->type
);
7628 free_percpu(pmu
->pmu_disable_count
);
7631 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7633 void perf_pmu_unregister(struct pmu
*pmu
)
7635 mutex_lock(&pmus_lock
);
7636 list_del_rcu(&pmu
->entry
);
7637 mutex_unlock(&pmus_lock
);
7640 * We dereference the pmu list under both SRCU and regular RCU, so
7641 * synchronize against both of those.
7643 synchronize_srcu(&pmus_srcu
);
7646 free_percpu(pmu
->pmu_disable_count
);
7647 if (pmu
->type
>= PERF_TYPE_MAX
)
7648 idr_remove(&pmu_idr
, pmu
->type
);
7649 device_del(pmu
->dev
);
7650 put_device(pmu
->dev
);
7651 free_pmu_context(pmu
);
7653 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7655 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7657 struct perf_event_context
*ctx
= NULL
;
7660 if (!try_module_get(pmu
->module
))
7663 if (event
->group_leader
!= event
) {
7665 * This ctx->mutex can nest when we're called through
7666 * inheritance. See the perf_event_ctx_lock_nested() comment.
7668 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7669 SINGLE_DEPTH_NESTING
);
7674 ret
= pmu
->event_init(event
);
7677 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7680 module_put(pmu
->module
);
7685 static struct pmu
*perf_init_event(struct perf_event
*event
)
7687 struct pmu
*pmu
= NULL
;
7691 idx
= srcu_read_lock(&pmus_srcu
);
7694 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7697 ret
= perf_try_init_event(pmu
, event
);
7703 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7704 ret
= perf_try_init_event(pmu
, event
);
7708 if (ret
!= -ENOENT
) {
7713 pmu
= ERR_PTR(-ENOENT
);
7715 srcu_read_unlock(&pmus_srcu
, idx
);
7720 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7725 if (is_cgroup_event(event
))
7726 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7729 static void account_event(struct perf_event
*event
)
7736 if (event
->attach_state
& PERF_ATTACH_TASK
)
7738 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7739 atomic_inc(&nr_mmap_events
);
7740 if (event
->attr
.comm
)
7741 atomic_inc(&nr_comm_events
);
7742 if (event
->attr
.task
)
7743 atomic_inc(&nr_task_events
);
7744 if (event
->attr
.freq
) {
7745 if (atomic_inc_return(&nr_freq_events
) == 1)
7746 tick_nohz_full_kick_all();
7748 if (event
->attr
.context_switch
) {
7749 atomic_inc(&nr_switch_events
);
7752 if (has_branch_stack(event
))
7754 if (is_cgroup_event(event
))
7758 static_key_slow_inc(&perf_sched_events
.key
);
7760 account_event_cpu(event
, event
->cpu
);
7764 * Allocate and initialize a event structure
7766 static struct perf_event
*
7767 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7768 struct task_struct
*task
,
7769 struct perf_event
*group_leader
,
7770 struct perf_event
*parent_event
,
7771 perf_overflow_handler_t overflow_handler
,
7772 void *context
, int cgroup_fd
)
7775 struct perf_event
*event
;
7776 struct hw_perf_event
*hwc
;
7779 if ((unsigned)cpu
>= nr_cpu_ids
) {
7780 if (!task
|| cpu
!= -1)
7781 return ERR_PTR(-EINVAL
);
7784 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7786 return ERR_PTR(-ENOMEM
);
7789 * Single events are their own group leaders, with an
7790 * empty sibling list:
7793 group_leader
= event
;
7795 mutex_init(&event
->child_mutex
);
7796 INIT_LIST_HEAD(&event
->child_list
);
7798 INIT_LIST_HEAD(&event
->group_entry
);
7799 INIT_LIST_HEAD(&event
->event_entry
);
7800 INIT_LIST_HEAD(&event
->sibling_list
);
7801 INIT_LIST_HEAD(&event
->rb_entry
);
7802 INIT_LIST_HEAD(&event
->active_entry
);
7803 INIT_HLIST_NODE(&event
->hlist_entry
);
7806 init_waitqueue_head(&event
->waitq
);
7807 init_irq_work(&event
->pending
, perf_pending_event
);
7809 mutex_init(&event
->mmap_mutex
);
7811 atomic_long_set(&event
->refcount
, 1);
7813 event
->attr
= *attr
;
7814 event
->group_leader
= group_leader
;
7818 event
->parent
= parent_event
;
7820 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7821 event
->id
= atomic64_inc_return(&perf_event_id
);
7823 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7826 event
->attach_state
= PERF_ATTACH_TASK
;
7828 * XXX pmu::event_init needs to know what task to account to
7829 * and we cannot use the ctx information because we need the
7830 * pmu before we get a ctx.
7832 event
->hw
.target
= task
;
7835 event
->clock
= &local_clock
;
7837 event
->clock
= parent_event
->clock
;
7839 if (!overflow_handler
&& parent_event
) {
7840 overflow_handler
= parent_event
->overflow_handler
;
7841 context
= parent_event
->overflow_handler_context
;
7844 event
->overflow_handler
= overflow_handler
;
7845 event
->overflow_handler_context
= context
;
7847 perf_event__state_init(event
);
7852 hwc
->sample_period
= attr
->sample_period
;
7853 if (attr
->freq
&& attr
->sample_freq
)
7854 hwc
->sample_period
= 1;
7855 hwc
->last_period
= hwc
->sample_period
;
7857 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7860 * we currently do not support PERF_FORMAT_GROUP on inherited events
7862 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7865 if (!has_branch_stack(event
))
7866 event
->attr
.branch_sample_type
= 0;
7868 if (cgroup_fd
!= -1) {
7869 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7874 pmu
= perf_init_event(event
);
7877 else if (IS_ERR(pmu
)) {
7882 err
= exclusive_event_init(event
);
7886 if (!event
->parent
) {
7887 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7888 err
= get_callchain_buffers();
7897 exclusive_event_destroy(event
);
7901 event
->destroy(event
);
7902 module_put(pmu
->module
);
7904 if (is_cgroup_event(event
))
7905 perf_detach_cgroup(event
);
7907 put_pid_ns(event
->ns
);
7910 return ERR_PTR(err
);
7913 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
7914 struct perf_event_attr
*attr
)
7919 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
7923 * zero the full structure, so that a short copy will be nice.
7925 memset(attr
, 0, sizeof(*attr
));
7927 ret
= get_user(size
, &uattr
->size
);
7931 if (size
> PAGE_SIZE
) /* silly large */
7934 if (!size
) /* abi compat */
7935 size
= PERF_ATTR_SIZE_VER0
;
7937 if (size
< PERF_ATTR_SIZE_VER0
)
7941 * If we're handed a bigger struct than we know of,
7942 * ensure all the unknown bits are 0 - i.e. new
7943 * user-space does not rely on any kernel feature
7944 * extensions we dont know about yet.
7946 if (size
> sizeof(*attr
)) {
7947 unsigned char __user
*addr
;
7948 unsigned char __user
*end
;
7951 addr
= (void __user
*)uattr
+ sizeof(*attr
);
7952 end
= (void __user
*)uattr
+ size
;
7954 for (; addr
< end
; addr
++) {
7955 ret
= get_user(val
, addr
);
7961 size
= sizeof(*attr
);
7964 ret
= copy_from_user(attr
, uattr
, size
);
7968 if (attr
->__reserved_1
)
7971 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
7974 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
7977 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
7978 u64 mask
= attr
->branch_sample_type
;
7980 /* only using defined bits */
7981 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
7984 /* at least one branch bit must be set */
7985 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
7988 /* propagate priv level, when not set for branch */
7989 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
7991 /* exclude_kernel checked on syscall entry */
7992 if (!attr
->exclude_kernel
)
7993 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
7995 if (!attr
->exclude_user
)
7996 mask
|= PERF_SAMPLE_BRANCH_USER
;
7998 if (!attr
->exclude_hv
)
7999 mask
|= PERF_SAMPLE_BRANCH_HV
;
8001 * adjust user setting (for HW filter setup)
8003 attr
->branch_sample_type
= mask
;
8005 /* privileged levels capture (kernel, hv): check permissions */
8006 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8007 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8011 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8012 ret
= perf_reg_validate(attr
->sample_regs_user
);
8017 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8018 if (!arch_perf_have_user_stack_dump())
8022 * We have __u32 type for the size, but so far
8023 * we can only use __u16 as maximum due to the
8024 * __u16 sample size limit.
8026 if (attr
->sample_stack_user
>= USHRT_MAX
)
8028 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8032 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8033 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8038 put_user(sizeof(*attr
), &uattr
->size
);
8044 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8046 struct ring_buffer
*rb
= NULL
;
8052 /* don't allow circular references */
8053 if (event
== output_event
)
8057 * Don't allow cross-cpu buffers
8059 if (output_event
->cpu
!= event
->cpu
)
8063 * If its not a per-cpu rb, it must be the same task.
8065 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8069 * Mixing clocks in the same buffer is trouble you don't need.
8071 if (output_event
->clock
!= event
->clock
)
8075 * If both events generate aux data, they must be on the same PMU
8077 if (has_aux(event
) && has_aux(output_event
) &&
8078 event
->pmu
!= output_event
->pmu
)
8082 mutex_lock(&event
->mmap_mutex
);
8083 /* Can't redirect output if we've got an active mmap() */
8084 if (atomic_read(&event
->mmap_count
))
8088 /* get the rb we want to redirect to */
8089 rb
= ring_buffer_get(output_event
);
8094 ring_buffer_attach(event
, rb
);
8098 mutex_unlock(&event
->mmap_mutex
);
8104 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8110 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8113 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8115 bool nmi_safe
= false;
8118 case CLOCK_MONOTONIC
:
8119 event
->clock
= &ktime_get_mono_fast_ns
;
8123 case CLOCK_MONOTONIC_RAW
:
8124 event
->clock
= &ktime_get_raw_fast_ns
;
8128 case CLOCK_REALTIME
:
8129 event
->clock
= &ktime_get_real_ns
;
8132 case CLOCK_BOOTTIME
:
8133 event
->clock
= &ktime_get_boot_ns
;
8137 event
->clock
= &ktime_get_tai_ns
;
8144 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8151 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8153 * @attr_uptr: event_id type attributes for monitoring/sampling
8156 * @group_fd: group leader event fd
8158 SYSCALL_DEFINE5(perf_event_open
,
8159 struct perf_event_attr __user
*, attr_uptr
,
8160 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8162 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8163 struct perf_event
*event
, *sibling
;
8164 struct perf_event_attr attr
;
8165 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8166 struct file
*event_file
= NULL
;
8167 struct fd group
= {NULL
, 0};
8168 struct task_struct
*task
= NULL
;
8173 int f_flags
= O_RDWR
;
8176 /* for future expandability... */
8177 if (flags
& ~PERF_FLAG_ALL
)
8180 err
= perf_copy_attr(attr_uptr
, &attr
);
8184 if (!attr
.exclude_kernel
) {
8185 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8190 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8193 if (attr
.sample_period
& (1ULL << 63))
8198 * In cgroup mode, the pid argument is used to pass the fd
8199 * opened to the cgroup directory in cgroupfs. The cpu argument
8200 * designates the cpu on which to monitor threads from that
8203 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8206 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8207 f_flags
|= O_CLOEXEC
;
8209 event_fd
= get_unused_fd_flags(f_flags
);
8213 if (group_fd
!= -1) {
8214 err
= perf_fget_light(group_fd
, &group
);
8217 group_leader
= group
.file
->private_data
;
8218 if (flags
& PERF_FLAG_FD_OUTPUT
)
8219 output_event
= group_leader
;
8220 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8221 group_leader
= NULL
;
8224 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8225 task
= find_lively_task_by_vpid(pid
);
8227 err
= PTR_ERR(task
);
8232 if (task
&& group_leader
&&
8233 group_leader
->attr
.inherit
!= attr
.inherit
) {
8240 if (flags
& PERF_FLAG_PID_CGROUP
)
8243 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8244 NULL
, NULL
, cgroup_fd
);
8245 if (IS_ERR(event
)) {
8246 err
= PTR_ERR(event
);
8250 if (is_sampling_event(event
)) {
8251 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8257 account_event(event
);
8260 * Special case software events and allow them to be part of
8261 * any hardware group.
8265 if (attr
.use_clockid
) {
8266 err
= perf_event_set_clock(event
, attr
.clockid
);
8272 (is_software_event(event
) != is_software_event(group_leader
))) {
8273 if (is_software_event(event
)) {
8275 * If event and group_leader are not both a software
8276 * event, and event is, then group leader is not.
8278 * Allow the addition of software events to !software
8279 * groups, this is safe because software events never
8282 pmu
= group_leader
->pmu
;
8283 } else if (is_software_event(group_leader
) &&
8284 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8286 * In case the group is a pure software group, and we
8287 * try to add a hardware event, move the whole group to
8288 * the hardware context.
8295 * Get the target context (task or percpu):
8297 ctx
= find_get_context(pmu
, task
, event
);
8303 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8309 put_task_struct(task
);
8314 * Look up the group leader (we will attach this event to it):
8320 * Do not allow a recursive hierarchy (this new sibling
8321 * becoming part of another group-sibling):
8323 if (group_leader
->group_leader
!= group_leader
)
8326 /* All events in a group should have the same clock */
8327 if (group_leader
->clock
!= event
->clock
)
8331 * Do not allow to attach to a group in a different
8332 * task or CPU context:
8336 * Make sure we're both on the same task, or both
8339 if (group_leader
->ctx
->task
!= ctx
->task
)
8343 * Make sure we're both events for the same CPU;
8344 * grouping events for different CPUs is broken; since
8345 * you can never concurrently schedule them anyhow.
8347 if (group_leader
->cpu
!= event
->cpu
)
8350 if (group_leader
->ctx
!= ctx
)
8355 * Only a group leader can be exclusive or pinned
8357 if (attr
.exclusive
|| attr
.pinned
)
8362 err
= perf_event_set_output(event
, output_event
);
8367 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8369 if (IS_ERR(event_file
)) {
8370 err
= PTR_ERR(event_file
);
8375 gctx
= group_leader
->ctx
;
8376 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8378 mutex_lock(&ctx
->mutex
);
8381 if (!perf_event_validate_size(event
)) {
8387 * Must be under the same ctx::mutex as perf_install_in_context(),
8388 * because we need to serialize with concurrent event creation.
8390 if (!exclusive_event_installable(event
, ctx
)) {
8391 /* exclusive and group stuff are assumed mutually exclusive */
8392 WARN_ON_ONCE(move_group
);
8398 WARN_ON_ONCE(ctx
->parent_ctx
);
8402 * See perf_event_ctx_lock() for comments on the details
8403 * of swizzling perf_event::ctx.
8405 perf_remove_from_context(group_leader
, false);
8407 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8409 perf_remove_from_context(sibling
, false);
8414 * Wait for everybody to stop referencing the events through
8415 * the old lists, before installing it on new lists.
8420 * Install the group siblings before the group leader.
8422 * Because a group leader will try and install the entire group
8423 * (through the sibling list, which is still in-tact), we can
8424 * end up with siblings installed in the wrong context.
8426 * By installing siblings first we NO-OP because they're not
8427 * reachable through the group lists.
8429 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8431 perf_event__state_init(sibling
);
8432 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8437 * Removing from the context ends up with disabled
8438 * event. What we want here is event in the initial
8439 * startup state, ready to be add into new context.
8441 perf_event__state_init(group_leader
);
8442 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8446 * Now that all events are installed in @ctx, nothing
8447 * references @gctx anymore, so drop the last reference we have
8454 * Precalculate sample_data sizes; do while holding ctx::mutex such
8455 * that we're serialized against further additions and before
8456 * perf_install_in_context() which is the point the event is active and
8457 * can use these values.
8459 perf_event__header_size(event
);
8460 perf_event__id_header_size(event
);
8462 perf_install_in_context(ctx
, event
, event
->cpu
);
8463 perf_unpin_context(ctx
);
8466 mutex_unlock(&gctx
->mutex
);
8467 mutex_unlock(&ctx
->mutex
);
8471 event
->owner
= current
;
8473 mutex_lock(¤t
->perf_event_mutex
);
8474 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8475 mutex_unlock(¤t
->perf_event_mutex
);
8478 * Drop the reference on the group_event after placing the
8479 * new event on the sibling_list. This ensures destruction
8480 * of the group leader will find the pointer to itself in
8481 * perf_group_detach().
8484 fd_install(event_fd
, event_file
);
8489 mutex_unlock(&gctx
->mutex
);
8490 mutex_unlock(&ctx
->mutex
);
8494 perf_unpin_context(ctx
);
8502 put_task_struct(task
);
8506 put_unused_fd(event_fd
);
8511 * perf_event_create_kernel_counter
8513 * @attr: attributes of the counter to create
8514 * @cpu: cpu in which the counter is bound
8515 * @task: task to profile (NULL for percpu)
8518 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8519 struct task_struct
*task
,
8520 perf_overflow_handler_t overflow_handler
,
8523 struct perf_event_context
*ctx
;
8524 struct perf_event
*event
;
8528 * Get the target context (task or percpu):
8531 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8532 overflow_handler
, context
, -1);
8533 if (IS_ERR(event
)) {
8534 err
= PTR_ERR(event
);
8538 /* Mark owner so we could distinguish it from user events. */
8539 event
->owner
= EVENT_OWNER_KERNEL
;
8541 account_event(event
);
8543 ctx
= find_get_context(event
->pmu
, task
, event
);
8549 WARN_ON_ONCE(ctx
->parent_ctx
);
8550 mutex_lock(&ctx
->mutex
);
8551 if (!exclusive_event_installable(event
, ctx
)) {
8552 mutex_unlock(&ctx
->mutex
);
8553 perf_unpin_context(ctx
);
8559 perf_install_in_context(ctx
, event
, cpu
);
8560 perf_unpin_context(ctx
);
8561 mutex_unlock(&ctx
->mutex
);
8568 return ERR_PTR(err
);
8570 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8572 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8574 struct perf_event_context
*src_ctx
;
8575 struct perf_event_context
*dst_ctx
;
8576 struct perf_event
*event
, *tmp
;
8579 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8580 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8583 * See perf_event_ctx_lock() for comments on the details
8584 * of swizzling perf_event::ctx.
8586 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8587 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8589 perf_remove_from_context(event
, false);
8590 unaccount_event_cpu(event
, src_cpu
);
8592 list_add(&event
->migrate_entry
, &events
);
8596 * Wait for the events to quiesce before re-instating them.
8601 * Re-instate events in 2 passes.
8603 * Skip over group leaders and only install siblings on this first
8604 * pass, siblings will not get enabled without a leader, however a
8605 * leader will enable its siblings, even if those are still on the old
8608 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8609 if (event
->group_leader
== event
)
8612 list_del(&event
->migrate_entry
);
8613 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8614 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8615 account_event_cpu(event
, dst_cpu
);
8616 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8621 * Once all the siblings are setup properly, install the group leaders
8624 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8625 list_del(&event
->migrate_entry
);
8626 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8627 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8628 account_event_cpu(event
, dst_cpu
);
8629 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8632 mutex_unlock(&dst_ctx
->mutex
);
8633 mutex_unlock(&src_ctx
->mutex
);
8635 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8637 static void sync_child_event(struct perf_event
*child_event
,
8638 struct task_struct
*child
)
8640 struct perf_event
*parent_event
= child_event
->parent
;
8643 if (child_event
->attr
.inherit_stat
)
8644 perf_event_read_event(child_event
, child
);
8646 child_val
= perf_event_count(child_event
);
8649 * Add back the child's count to the parent's count:
8651 atomic64_add(child_val
, &parent_event
->child_count
);
8652 atomic64_add(child_event
->total_time_enabled
,
8653 &parent_event
->child_total_time_enabled
);
8654 atomic64_add(child_event
->total_time_running
,
8655 &parent_event
->child_total_time_running
);
8658 * Remove this event from the parent's list
8660 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8661 mutex_lock(&parent_event
->child_mutex
);
8662 list_del_init(&child_event
->child_list
);
8663 mutex_unlock(&parent_event
->child_mutex
);
8666 * Make sure user/parent get notified, that we just
8669 perf_event_wakeup(parent_event
);
8672 * Release the parent event, if this was the last
8675 put_event(parent_event
);
8679 __perf_event_exit_task(struct perf_event
*child_event
,
8680 struct perf_event_context
*child_ctx
,
8681 struct task_struct
*child
)
8684 * Do not destroy the 'original' grouping; because of the context
8685 * switch optimization the original events could've ended up in a
8686 * random child task.
8688 * If we were to destroy the original group, all group related
8689 * operations would cease to function properly after this random
8692 * Do destroy all inherited groups, we don't care about those
8693 * and being thorough is better.
8695 raw_spin_lock_irq(&child_ctx
->lock
);
8696 WARN_ON_ONCE(child_ctx
->is_active
);
8698 if (!!child_event
->parent
)
8699 perf_group_detach(child_event
);
8700 list_del_event(child_event
, child_ctx
);
8701 raw_spin_unlock_irq(&child_ctx
->lock
);
8704 * It can happen that the parent exits first, and has events
8705 * that are still around due to the child reference. These
8706 * events need to be zapped.
8708 if (child_event
->parent
) {
8709 sync_child_event(child_event
, child
);
8710 free_event(child_event
);
8712 child_event
->state
= PERF_EVENT_STATE_EXIT
;
8713 perf_event_wakeup(child_event
);
8717 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8719 struct perf_event
*child_event
, *next
;
8720 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8722 if (likely(!child
->perf_event_ctxp
[ctxn
]))
8725 local_irq_disable();
8726 WARN_ON_ONCE(child
!= current
);
8728 * We can't reschedule here because interrupts are disabled,
8729 * and child must be current.
8731 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
8734 * Take the context lock here so that if find_get_context is
8735 * reading child->perf_event_ctxp, we wait until it has
8736 * incremented the context's refcount before we do put_ctx below.
8738 raw_spin_lock(&child_ctx
->lock
);
8739 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
);
8740 child
->perf_event_ctxp
[ctxn
] = NULL
;
8743 * If this context is a clone; unclone it so it can't get
8744 * swapped to another process while we're removing all
8745 * the events from it.
8747 clone_ctx
= unclone_ctx(child_ctx
);
8748 update_context_time(child_ctx
);
8749 raw_spin_unlock_irq(&child_ctx
->lock
);
8755 * Report the task dead after unscheduling the events so that we
8756 * won't get any samples after PERF_RECORD_EXIT. We can however still
8757 * get a few PERF_RECORD_READ events.
8759 perf_event_task(child
, child_ctx
, 0);
8762 * We can recurse on the same lock type through:
8764 * __perf_event_exit_task()
8765 * sync_child_event()
8767 * mutex_lock(&ctx->mutex)
8769 * But since its the parent context it won't be the same instance.
8771 mutex_lock(&child_ctx
->mutex
);
8773 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8774 __perf_event_exit_task(child_event
, child_ctx
, child
);
8776 mutex_unlock(&child_ctx
->mutex
);
8782 * When a child task exits, feed back event values to parent events.
8784 void perf_event_exit_task(struct task_struct
*child
)
8786 struct perf_event
*event
, *tmp
;
8789 mutex_lock(&child
->perf_event_mutex
);
8790 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8792 list_del_init(&event
->owner_entry
);
8795 * Ensure the list deletion is visible before we clear
8796 * the owner, closes a race against perf_release() where
8797 * we need to serialize on the owner->perf_event_mutex.
8800 event
->owner
= NULL
;
8802 mutex_unlock(&child
->perf_event_mutex
);
8804 for_each_task_context_nr(ctxn
)
8805 perf_event_exit_task_context(child
, ctxn
);
8808 * The perf_event_exit_task_context calls perf_event_task
8809 * with child's task_ctx, which generates EXIT events for
8810 * child contexts and sets child->perf_event_ctxp[] to NULL.
8811 * At this point we need to send EXIT events to cpu contexts.
8813 perf_event_task(child
, NULL
, 0);
8816 static void perf_free_event(struct perf_event
*event
,
8817 struct perf_event_context
*ctx
)
8819 struct perf_event
*parent
= event
->parent
;
8821 if (WARN_ON_ONCE(!parent
))
8824 mutex_lock(&parent
->child_mutex
);
8825 list_del_init(&event
->child_list
);
8826 mutex_unlock(&parent
->child_mutex
);
8830 raw_spin_lock_irq(&ctx
->lock
);
8831 perf_group_detach(event
);
8832 list_del_event(event
, ctx
);
8833 raw_spin_unlock_irq(&ctx
->lock
);
8838 * Free an unexposed, unused context as created by inheritance by
8839 * perf_event_init_task below, used by fork() in case of fail.
8841 * Not all locks are strictly required, but take them anyway to be nice and
8842 * help out with the lockdep assertions.
8844 void perf_event_free_task(struct task_struct
*task
)
8846 struct perf_event_context
*ctx
;
8847 struct perf_event
*event
, *tmp
;
8850 for_each_task_context_nr(ctxn
) {
8851 ctx
= task
->perf_event_ctxp
[ctxn
];
8855 mutex_lock(&ctx
->mutex
);
8857 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8859 perf_free_event(event
, ctx
);
8861 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8863 perf_free_event(event
, ctx
);
8865 if (!list_empty(&ctx
->pinned_groups
) ||
8866 !list_empty(&ctx
->flexible_groups
))
8869 mutex_unlock(&ctx
->mutex
);
8875 void perf_event_delayed_put(struct task_struct
*task
)
8879 for_each_task_context_nr(ctxn
)
8880 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8883 struct perf_event
*perf_event_get(unsigned int fd
)
8887 struct perf_event
*event
;
8889 err
= perf_fget_light(fd
, &f
);
8891 return ERR_PTR(err
);
8893 event
= f
.file
->private_data
;
8894 atomic_long_inc(&event
->refcount
);
8900 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
8903 return ERR_PTR(-EINVAL
);
8905 return &event
->attr
;
8909 * inherit a event from parent task to child task:
8911 static struct perf_event
*
8912 inherit_event(struct perf_event
*parent_event
,
8913 struct task_struct
*parent
,
8914 struct perf_event_context
*parent_ctx
,
8915 struct task_struct
*child
,
8916 struct perf_event
*group_leader
,
8917 struct perf_event_context
*child_ctx
)
8919 enum perf_event_active_state parent_state
= parent_event
->state
;
8920 struct perf_event
*child_event
;
8921 unsigned long flags
;
8924 * Instead of creating recursive hierarchies of events,
8925 * we link inherited events back to the original parent,
8926 * which has a filp for sure, which we use as the reference
8929 if (parent_event
->parent
)
8930 parent_event
= parent_event
->parent
;
8932 child_event
= perf_event_alloc(&parent_event
->attr
,
8935 group_leader
, parent_event
,
8937 if (IS_ERR(child_event
))
8940 if (is_orphaned_event(parent_event
) ||
8941 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
8942 free_event(child_event
);
8949 * Make the child state follow the state of the parent event,
8950 * not its attr.disabled bit. We hold the parent's mutex,
8951 * so we won't race with perf_event_{en, dis}able_family.
8953 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
8954 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
8956 child_event
->state
= PERF_EVENT_STATE_OFF
;
8958 if (parent_event
->attr
.freq
) {
8959 u64 sample_period
= parent_event
->hw
.sample_period
;
8960 struct hw_perf_event
*hwc
= &child_event
->hw
;
8962 hwc
->sample_period
= sample_period
;
8963 hwc
->last_period
= sample_period
;
8965 local64_set(&hwc
->period_left
, sample_period
);
8968 child_event
->ctx
= child_ctx
;
8969 child_event
->overflow_handler
= parent_event
->overflow_handler
;
8970 child_event
->overflow_handler_context
8971 = parent_event
->overflow_handler_context
;
8974 * Precalculate sample_data sizes
8976 perf_event__header_size(child_event
);
8977 perf_event__id_header_size(child_event
);
8980 * Link it up in the child's context:
8982 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
8983 add_event_to_ctx(child_event
, child_ctx
);
8984 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8987 * Link this into the parent event's child list
8989 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8990 mutex_lock(&parent_event
->child_mutex
);
8991 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
8992 mutex_unlock(&parent_event
->child_mutex
);
8997 static int inherit_group(struct perf_event
*parent_event
,
8998 struct task_struct
*parent
,
8999 struct perf_event_context
*parent_ctx
,
9000 struct task_struct
*child
,
9001 struct perf_event_context
*child_ctx
)
9003 struct perf_event
*leader
;
9004 struct perf_event
*sub
;
9005 struct perf_event
*child_ctr
;
9007 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9008 child
, NULL
, child_ctx
);
9010 return PTR_ERR(leader
);
9011 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9012 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9013 child
, leader
, child_ctx
);
9014 if (IS_ERR(child_ctr
))
9015 return PTR_ERR(child_ctr
);
9021 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9022 struct perf_event_context
*parent_ctx
,
9023 struct task_struct
*child
, int ctxn
,
9027 struct perf_event_context
*child_ctx
;
9029 if (!event
->attr
.inherit
) {
9034 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9037 * This is executed from the parent task context, so
9038 * inherit events that have been marked for cloning.
9039 * First allocate and initialize a context for the
9043 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9047 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9050 ret
= inherit_group(event
, parent
, parent_ctx
,
9060 * Initialize the perf_event context in task_struct
9062 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9064 struct perf_event_context
*child_ctx
, *parent_ctx
;
9065 struct perf_event_context
*cloned_ctx
;
9066 struct perf_event
*event
;
9067 struct task_struct
*parent
= current
;
9068 int inherited_all
= 1;
9069 unsigned long flags
;
9072 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9076 * If the parent's context is a clone, pin it so it won't get
9079 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9084 * No need to check if parent_ctx != NULL here; since we saw
9085 * it non-NULL earlier, the only reason for it to become NULL
9086 * is if we exit, and since we're currently in the middle of
9087 * a fork we can't be exiting at the same time.
9091 * Lock the parent list. No need to lock the child - not PID
9092 * hashed yet and not running, so nobody can access it.
9094 mutex_lock(&parent_ctx
->mutex
);
9097 * We dont have to disable NMIs - we are only looking at
9098 * the list, not manipulating it:
9100 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9101 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9102 child
, ctxn
, &inherited_all
);
9108 * We can't hold ctx->lock when iterating the ->flexible_group list due
9109 * to allocations, but we need to prevent rotation because
9110 * rotate_ctx() will change the list from interrupt context.
9112 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9113 parent_ctx
->rotate_disable
= 1;
9114 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9116 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9117 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9118 child
, ctxn
, &inherited_all
);
9123 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9124 parent_ctx
->rotate_disable
= 0;
9126 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9128 if (child_ctx
&& inherited_all
) {
9130 * Mark the child context as a clone of the parent
9131 * context, or of whatever the parent is a clone of.
9133 * Note that if the parent is a clone, the holding of
9134 * parent_ctx->lock avoids it from being uncloned.
9136 cloned_ctx
= parent_ctx
->parent_ctx
;
9138 child_ctx
->parent_ctx
= cloned_ctx
;
9139 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9141 child_ctx
->parent_ctx
= parent_ctx
;
9142 child_ctx
->parent_gen
= parent_ctx
->generation
;
9144 get_ctx(child_ctx
->parent_ctx
);
9147 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9148 mutex_unlock(&parent_ctx
->mutex
);
9150 perf_unpin_context(parent_ctx
);
9151 put_ctx(parent_ctx
);
9157 * Initialize the perf_event context in task_struct
9159 int perf_event_init_task(struct task_struct
*child
)
9163 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9164 mutex_init(&child
->perf_event_mutex
);
9165 INIT_LIST_HEAD(&child
->perf_event_list
);
9167 for_each_task_context_nr(ctxn
) {
9168 ret
= perf_event_init_context(child
, ctxn
);
9170 perf_event_free_task(child
);
9178 static void __init
perf_event_init_all_cpus(void)
9180 struct swevent_htable
*swhash
;
9183 for_each_possible_cpu(cpu
) {
9184 swhash
= &per_cpu(swevent_htable
, cpu
);
9185 mutex_init(&swhash
->hlist_mutex
);
9186 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9190 static void perf_event_init_cpu(int cpu
)
9192 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9194 mutex_lock(&swhash
->hlist_mutex
);
9195 if (swhash
->hlist_refcount
> 0) {
9196 struct swevent_hlist
*hlist
;
9198 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9200 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9202 mutex_unlock(&swhash
->hlist_mutex
);
9205 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9206 static void __perf_event_exit_context(void *__info
)
9208 struct perf_event_context
*ctx
= __info
;
9209 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
9210 struct perf_event
*event
;
9212 raw_spin_lock(&ctx
->lock
);
9213 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
9214 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)(unsigned long)true);
9215 raw_spin_unlock(&ctx
->lock
);
9218 static void perf_event_exit_cpu_context(int cpu
)
9220 struct perf_event_context
*ctx
;
9224 idx
= srcu_read_lock(&pmus_srcu
);
9225 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9226 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9228 mutex_lock(&ctx
->mutex
);
9229 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9230 mutex_unlock(&ctx
->mutex
);
9232 srcu_read_unlock(&pmus_srcu
, idx
);
9235 static void perf_event_exit_cpu(int cpu
)
9237 perf_event_exit_cpu_context(cpu
);
9240 static inline void perf_event_exit_cpu(int cpu
) { }
9244 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9248 for_each_online_cpu(cpu
)
9249 perf_event_exit_cpu(cpu
);
9255 * Run the perf reboot notifier at the very last possible moment so that
9256 * the generic watchdog code runs as long as possible.
9258 static struct notifier_block perf_reboot_notifier
= {
9259 .notifier_call
= perf_reboot
,
9260 .priority
= INT_MIN
,
9264 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9266 unsigned int cpu
= (long)hcpu
;
9268 switch (action
& ~CPU_TASKS_FROZEN
) {
9270 case CPU_UP_PREPARE
:
9271 case CPU_DOWN_FAILED
:
9272 perf_event_init_cpu(cpu
);
9275 case CPU_UP_CANCELED
:
9276 case CPU_DOWN_PREPARE
:
9277 perf_event_exit_cpu(cpu
);
9286 void __init
perf_event_init(void)
9292 perf_event_init_all_cpus();
9293 init_srcu_struct(&pmus_srcu
);
9294 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9295 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9296 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9298 perf_cpu_notifier(perf_cpu_notify
);
9299 register_reboot_notifier(&perf_reboot_notifier
);
9301 ret
= init_hw_breakpoint();
9302 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9304 /* do not patch jump label more than once per second */
9305 jump_label_rate_limit(&perf_sched_events
, HZ
);
9308 * Build time assertion that we keep the data_head at the intended
9309 * location. IOW, validation we got the __reserved[] size right.
9311 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9315 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9318 struct perf_pmu_events_attr
*pmu_attr
=
9319 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9321 if (pmu_attr
->event_str
)
9322 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9327 static int __init
perf_event_sysfs_init(void)
9332 mutex_lock(&pmus_lock
);
9334 ret
= bus_register(&pmu_bus
);
9338 list_for_each_entry(pmu
, &pmus
, entry
) {
9339 if (!pmu
->name
|| pmu
->type
< 0)
9342 ret
= pmu_dev_alloc(pmu
);
9343 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9345 pmu_bus_running
= 1;
9349 mutex_unlock(&pmus_lock
);
9353 device_initcall(perf_event_sysfs_init
);
9355 #ifdef CONFIG_CGROUP_PERF
9356 static struct cgroup_subsys_state
*
9357 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9359 struct perf_cgroup
*jc
;
9361 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9363 return ERR_PTR(-ENOMEM
);
9365 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9368 return ERR_PTR(-ENOMEM
);
9374 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9376 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9378 free_percpu(jc
->info
);
9382 static int __perf_cgroup_move(void *info
)
9384 struct task_struct
*task
= info
;
9386 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9391 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
9393 struct task_struct
*task
;
9394 struct cgroup_subsys_state
*css
;
9396 cgroup_taskset_for_each(task
, css
, tset
)
9397 task_function_call(task
, __perf_cgroup_move
, task
);
9400 struct cgroup_subsys perf_event_cgrp_subsys
= {
9401 .css_alloc
= perf_cgroup_css_alloc
,
9402 .css_free
= perf_cgroup_css_free
,
9403 .attach
= perf_cgroup_attach
,
9405 #endif /* CONFIG_CGROUP_PERF */