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 typedef int (*remote_function_f
)(void *);
54 struct remote_function_call
{
55 struct task_struct
*p
;
56 remote_function_f func
;
61 static void remote_function(void *data
)
63 struct remote_function_call
*tfc
= data
;
64 struct task_struct
*p
= tfc
->p
;
68 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
72 tfc
->ret
= tfc
->func(tfc
->info
);
76 * task_function_call - call a function on the cpu on which a task runs
77 * @p: the task to evaluate
78 * @func: the function to be called
79 * @info: the function call argument
81 * Calls the function @func when the task is currently running. This might
82 * be on the current CPU, which just calls the function directly
84 * returns: @func return value, or
85 * -ESRCH - when the process isn't running
86 * -EAGAIN - when the process moved away
89 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
91 struct remote_function_call data
= {
95 .ret
= -ESRCH
, /* No such (running) process */
99 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
105 * cpu_function_call - call a function on the cpu
106 * @func: the function to be called
107 * @info: the function call argument
109 * Calls the function @func on the remote cpu.
111 * returns: @func return value or -ENXIO when the cpu is offline
113 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
115 struct remote_function_call data
= {
119 .ret
= -ENXIO
, /* No such CPU */
122 smp_call_function_single(cpu
, remote_function
, &data
, 1);
127 static inline struct perf_cpu_context
*
128 __get_cpu_context(struct perf_event_context
*ctx
)
130 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
133 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
134 struct perf_event_context
*ctx
)
136 raw_spin_lock(&cpuctx
->ctx
.lock
);
138 raw_spin_lock(&ctx
->lock
);
141 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
142 struct perf_event_context
*ctx
)
145 raw_spin_unlock(&ctx
->lock
);
146 raw_spin_unlock(&cpuctx
->ctx
.lock
);
149 #define TASK_TOMBSTONE ((void *)-1L)
151 static bool is_kernel_event(struct perf_event
*event
)
153 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
157 * On task ctx scheduling...
159 * When !ctx->nr_events a task context will not be scheduled. This means
160 * we can disable the scheduler hooks (for performance) without leaving
161 * pending task ctx state.
163 * This however results in two special cases:
165 * - removing the last event from a task ctx; this is relatively straight
166 * forward and is done in __perf_remove_from_context.
168 * - adding the first event to a task ctx; this is tricky because we cannot
169 * rely on ctx->is_active and therefore cannot use event_function_call().
170 * See perf_install_in_context().
172 * This is because we need a ctx->lock serialized variable (ctx->is_active)
173 * to reliably determine if a particular task/context is scheduled in. The
174 * task_curr() use in task_function_call() is racy in that a remote context
175 * switch is not a single atomic operation.
177 * As is, the situation is 'safe' because we set rq->curr before we do the
178 * actual context switch. This means that task_curr() will fail early, but
179 * we'll continue spinning on ctx->is_active until we've passed
180 * perf_event_task_sched_out().
182 * Without this ctx->lock serialized variable we could have race where we find
183 * the task (and hence the context) would not be active while in fact they are.
185 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
188 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
189 struct perf_event_context
*, void *);
191 struct event_function_struct
{
192 struct perf_event
*event
;
197 static int event_function(void *info
)
199 struct event_function_struct
*efs
= info
;
200 struct perf_event
*event
= efs
->event
;
201 struct perf_event_context
*ctx
= event
->ctx
;
202 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
203 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
206 WARN_ON_ONCE(!irqs_disabled());
208 perf_ctx_lock(cpuctx
, task_ctx
);
210 * Since we do the IPI call without holding ctx->lock things can have
211 * changed, double check we hit the task we set out to hit.
214 if (ctx
->task
!= current
) {
220 * We only use event_function_call() on established contexts,
221 * and event_function() is only ever called when active (or
222 * rather, we'll have bailed in task_function_call() or the
223 * above ctx->task != current test), therefore we must have
224 * ctx->is_active here.
226 WARN_ON_ONCE(!ctx
->is_active
);
228 * And since we have ctx->is_active, cpuctx->task_ctx must
231 WARN_ON_ONCE(task_ctx
!= ctx
);
233 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
236 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
238 perf_ctx_unlock(cpuctx
, task_ctx
);
243 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
245 struct event_function_struct efs
= {
251 int ret
= event_function(&efs
);
255 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
257 struct perf_event_context
*ctx
= event
->ctx
;
258 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
259 struct event_function_struct efs
= {
265 if (!event
->parent
) {
267 * If this is a !child event, we must hold ctx::mutex to
268 * stabilize the the event->ctx relation. See
269 * perf_event_ctx_lock().
271 lockdep_assert_held(&ctx
->mutex
);
275 cpu_function_call(event
->cpu
, event_function
, &efs
);
280 if (task
== TASK_TOMBSTONE
)
283 if (!task_function_call(task
, event_function
, &efs
))
286 raw_spin_lock_irq(&ctx
->lock
);
288 * Reload the task pointer, it might have been changed by
289 * a concurrent perf_event_context_sched_out().
292 if (task
!= TASK_TOMBSTONE
) {
293 if (ctx
->is_active
) {
294 raw_spin_unlock_irq(&ctx
->lock
);
297 func(event
, NULL
, ctx
, data
);
299 raw_spin_unlock_irq(&ctx
->lock
);
302 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
303 PERF_FLAG_FD_OUTPUT |\
304 PERF_FLAG_PID_CGROUP |\
305 PERF_FLAG_FD_CLOEXEC)
308 * branch priv levels that need permission checks
310 #define PERF_SAMPLE_BRANCH_PERM_PLM \
311 (PERF_SAMPLE_BRANCH_KERNEL |\
312 PERF_SAMPLE_BRANCH_HV)
315 EVENT_FLEXIBLE
= 0x1,
317 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
321 * perf_sched_events : >0 events exist
322 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
324 struct static_key_deferred perf_sched_events __read_mostly
;
325 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
326 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
328 static atomic_t nr_mmap_events __read_mostly
;
329 static atomic_t nr_comm_events __read_mostly
;
330 static atomic_t nr_task_events __read_mostly
;
331 static atomic_t nr_freq_events __read_mostly
;
332 static atomic_t nr_switch_events __read_mostly
;
334 static LIST_HEAD(pmus
);
335 static DEFINE_MUTEX(pmus_lock
);
336 static struct srcu_struct pmus_srcu
;
339 * perf event paranoia level:
340 * -1 - not paranoid at all
341 * 0 - disallow raw tracepoint access for unpriv
342 * 1 - disallow cpu events for unpriv
343 * 2 - disallow kernel profiling for unpriv
345 int sysctl_perf_event_paranoid __read_mostly
= 1;
347 /* Minimum for 512 kiB + 1 user control page */
348 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
351 * max perf event sample rate
353 #define DEFAULT_MAX_SAMPLE_RATE 100000
354 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
355 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
357 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
359 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
360 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
362 static int perf_sample_allowed_ns __read_mostly
=
363 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
365 static void update_perf_cpu_limits(void)
367 u64 tmp
= perf_sample_period_ns
;
369 tmp
*= sysctl_perf_cpu_time_max_percent
;
371 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
374 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
376 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
377 void __user
*buffer
, size_t *lenp
,
380 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
385 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
386 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
387 update_perf_cpu_limits();
392 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
394 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
395 void __user
*buffer
, size_t *lenp
,
398 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
403 update_perf_cpu_limits();
409 * perf samples are done in some very critical code paths (NMIs).
410 * If they take too much CPU time, the system can lock up and not
411 * get any real work done. This will drop the sample rate when
412 * we detect that events are taking too long.
414 #define NR_ACCUMULATED_SAMPLES 128
415 static DEFINE_PER_CPU(u64
, running_sample_length
);
417 static void perf_duration_warn(struct irq_work
*w
)
419 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
420 u64 avg_local_sample_len
;
421 u64 local_samples_len
;
423 local_samples_len
= __this_cpu_read(running_sample_length
);
424 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
426 printk_ratelimited(KERN_WARNING
427 "perf interrupt took too long (%lld > %lld), lowering "
428 "kernel.perf_event_max_sample_rate to %d\n",
429 avg_local_sample_len
, allowed_ns
>> 1,
430 sysctl_perf_event_sample_rate
);
433 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
435 void perf_sample_event_took(u64 sample_len_ns
)
437 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
438 u64 avg_local_sample_len
;
439 u64 local_samples_len
;
444 /* decay the counter by 1 average sample */
445 local_samples_len
= __this_cpu_read(running_sample_length
);
446 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
447 local_samples_len
+= sample_len_ns
;
448 __this_cpu_write(running_sample_length
, local_samples_len
);
451 * note: this will be biased artifically low until we have
452 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
453 * from having to maintain a count.
455 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
457 if (avg_local_sample_len
<= allowed_ns
)
460 if (max_samples_per_tick
<= 1)
463 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
464 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
465 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
467 update_perf_cpu_limits();
469 if (!irq_work_queue(&perf_duration_work
)) {
470 early_printk("perf interrupt took too long (%lld > %lld), lowering "
471 "kernel.perf_event_max_sample_rate to %d\n",
472 avg_local_sample_len
, allowed_ns
>> 1,
473 sysctl_perf_event_sample_rate
);
477 static atomic64_t perf_event_id
;
479 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
480 enum event_type_t event_type
);
482 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
483 enum event_type_t event_type
,
484 struct task_struct
*task
);
486 static void update_context_time(struct perf_event_context
*ctx
);
487 static u64
perf_event_time(struct perf_event
*event
);
489 void __weak
perf_event_print_debug(void) { }
491 extern __weak
const char *perf_pmu_name(void)
496 static inline u64
perf_clock(void)
498 return local_clock();
501 static inline u64
perf_event_clock(struct perf_event
*event
)
503 return event
->clock();
506 #ifdef CONFIG_CGROUP_PERF
509 perf_cgroup_match(struct perf_event
*event
)
511 struct perf_event_context
*ctx
= event
->ctx
;
512 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
514 /* @event doesn't care about cgroup */
518 /* wants specific cgroup scope but @cpuctx isn't associated with any */
523 * Cgroup scoping is recursive. An event enabled for a cgroup is
524 * also enabled for all its descendant cgroups. If @cpuctx's
525 * cgroup is a descendant of @event's (the test covers identity
526 * case), it's a match.
528 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
529 event
->cgrp
->css
.cgroup
);
532 static inline void perf_detach_cgroup(struct perf_event
*event
)
534 css_put(&event
->cgrp
->css
);
538 static inline int is_cgroup_event(struct perf_event
*event
)
540 return event
->cgrp
!= NULL
;
543 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
545 struct perf_cgroup_info
*t
;
547 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
551 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
553 struct perf_cgroup_info
*info
;
558 info
= this_cpu_ptr(cgrp
->info
);
560 info
->time
+= now
- info
->timestamp
;
561 info
->timestamp
= now
;
564 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
566 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
568 __update_cgrp_time(cgrp_out
);
571 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
573 struct perf_cgroup
*cgrp
;
576 * ensure we access cgroup data only when needed and
577 * when we know the cgroup is pinned (css_get)
579 if (!is_cgroup_event(event
))
582 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
584 * Do not update time when cgroup is not active
586 if (cgrp
== event
->cgrp
)
587 __update_cgrp_time(event
->cgrp
);
591 perf_cgroup_set_timestamp(struct task_struct
*task
,
592 struct perf_event_context
*ctx
)
594 struct perf_cgroup
*cgrp
;
595 struct perf_cgroup_info
*info
;
598 * ctx->lock held by caller
599 * ensure we do not access cgroup data
600 * unless we have the cgroup pinned (css_get)
602 if (!task
|| !ctx
->nr_cgroups
)
605 cgrp
= perf_cgroup_from_task(task
, ctx
);
606 info
= this_cpu_ptr(cgrp
->info
);
607 info
->timestamp
= ctx
->timestamp
;
610 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
611 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
614 * reschedule events based on the cgroup constraint of task.
616 * mode SWOUT : schedule out everything
617 * mode SWIN : schedule in based on cgroup for next
619 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
621 struct perf_cpu_context
*cpuctx
;
626 * disable interrupts to avoid geting nr_cgroup
627 * changes via __perf_event_disable(). Also
630 local_irq_save(flags
);
633 * we reschedule only in the presence of cgroup
634 * constrained events.
637 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
638 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
639 if (cpuctx
->unique_pmu
!= pmu
)
640 continue; /* ensure we process each cpuctx once */
643 * perf_cgroup_events says at least one
644 * context on this CPU has cgroup events.
646 * ctx->nr_cgroups reports the number of cgroup
647 * events for a context.
649 if (cpuctx
->ctx
.nr_cgroups
> 0) {
650 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
651 perf_pmu_disable(cpuctx
->ctx
.pmu
);
653 if (mode
& PERF_CGROUP_SWOUT
) {
654 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
656 * must not be done before ctxswout due
657 * to event_filter_match() in event_sched_out()
662 if (mode
& PERF_CGROUP_SWIN
) {
663 WARN_ON_ONCE(cpuctx
->cgrp
);
665 * set cgrp before ctxsw in to allow
666 * event_filter_match() to not have to pass
668 * we pass the cpuctx->ctx to perf_cgroup_from_task()
669 * because cgorup events are only per-cpu
671 cpuctx
->cgrp
= perf_cgroup_from_task(task
, &cpuctx
->ctx
);
672 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
674 perf_pmu_enable(cpuctx
->ctx
.pmu
);
675 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
679 local_irq_restore(flags
);
682 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
683 struct task_struct
*next
)
685 struct perf_cgroup
*cgrp1
;
686 struct perf_cgroup
*cgrp2
= NULL
;
690 * we come here when we know perf_cgroup_events > 0
691 * we do not need to pass the ctx here because we know
692 * we are holding the rcu lock
694 cgrp1
= perf_cgroup_from_task(task
, NULL
);
695 cgrp2
= perf_cgroup_from_task(next
, NULL
);
698 * only schedule out current cgroup events if we know
699 * that we are switching to a different cgroup. Otherwise,
700 * do no touch the cgroup events.
703 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
708 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
709 struct task_struct
*task
)
711 struct perf_cgroup
*cgrp1
;
712 struct perf_cgroup
*cgrp2
= NULL
;
716 * we come here when we know perf_cgroup_events > 0
717 * we do not need to pass the ctx here because we know
718 * we are holding the rcu lock
720 cgrp1
= perf_cgroup_from_task(task
, NULL
);
721 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
724 * only need to schedule in cgroup events if we are changing
725 * cgroup during ctxsw. Cgroup events were not scheduled
726 * out of ctxsw out if that was not the case.
729 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
734 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
735 struct perf_event_attr
*attr
,
736 struct perf_event
*group_leader
)
738 struct perf_cgroup
*cgrp
;
739 struct cgroup_subsys_state
*css
;
740 struct fd f
= fdget(fd
);
746 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
747 &perf_event_cgrp_subsys
);
753 cgrp
= container_of(css
, struct perf_cgroup
, css
);
757 * all events in a group must monitor
758 * the same cgroup because a task belongs
759 * to only one perf cgroup at a time
761 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
762 perf_detach_cgroup(event
);
771 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
773 struct perf_cgroup_info
*t
;
774 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
775 event
->shadow_ctx_time
= now
- t
->timestamp
;
779 perf_cgroup_defer_enabled(struct perf_event
*event
)
782 * when the current task's perf cgroup does not match
783 * the event's, we need to remember to call the
784 * perf_mark_enable() function the first time a task with
785 * a matching perf cgroup is scheduled in.
787 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
788 event
->cgrp_defer_enabled
= 1;
792 perf_cgroup_mark_enabled(struct perf_event
*event
,
793 struct perf_event_context
*ctx
)
795 struct perf_event
*sub
;
796 u64 tstamp
= perf_event_time(event
);
798 if (!event
->cgrp_defer_enabled
)
801 event
->cgrp_defer_enabled
= 0;
803 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
804 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
805 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
806 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
807 sub
->cgrp_defer_enabled
= 0;
811 #else /* !CONFIG_CGROUP_PERF */
814 perf_cgroup_match(struct perf_event
*event
)
819 static inline void perf_detach_cgroup(struct perf_event
*event
)
822 static inline int is_cgroup_event(struct perf_event
*event
)
827 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
832 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
836 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
840 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
841 struct task_struct
*next
)
845 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
846 struct task_struct
*task
)
850 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
851 struct perf_event_attr
*attr
,
852 struct perf_event
*group_leader
)
858 perf_cgroup_set_timestamp(struct task_struct
*task
,
859 struct perf_event_context
*ctx
)
864 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
869 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
873 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
879 perf_cgroup_defer_enabled(struct perf_event
*event
)
884 perf_cgroup_mark_enabled(struct perf_event
*event
,
885 struct perf_event_context
*ctx
)
891 * set default to be dependent on timer tick just
894 #define PERF_CPU_HRTIMER (1000 / HZ)
896 * function must be called with interrupts disbled
898 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
900 struct perf_cpu_context
*cpuctx
;
903 WARN_ON(!irqs_disabled());
905 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
906 rotations
= perf_rotate_context(cpuctx
);
908 raw_spin_lock(&cpuctx
->hrtimer_lock
);
910 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
912 cpuctx
->hrtimer_active
= 0;
913 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
915 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
918 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
920 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
921 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
924 /* no multiplexing needed for SW PMU */
925 if (pmu
->task_ctx_nr
== perf_sw_context
)
929 * check default is sane, if not set then force to
930 * default interval (1/tick)
932 interval
= pmu
->hrtimer_interval_ms
;
934 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
936 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
938 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
939 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
940 timer
->function
= perf_mux_hrtimer_handler
;
943 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
945 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
946 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
950 if (pmu
->task_ctx_nr
== perf_sw_context
)
953 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
954 if (!cpuctx
->hrtimer_active
) {
955 cpuctx
->hrtimer_active
= 1;
956 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
957 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
959 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
964 void perf_pmu_disable(struct pmu
*pmu
)
966 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
968 pmu
->pmu_disable(pmu
);
971 void perf_pmu_enable(struct pmu
*pmu
)
973 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
975 pmu
->pmu_enable(pmu
);
978 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
981 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
982 * perf_event_task_tick() are fully serialized because they're strictly cpu
983 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
984 * disabled, while perf_event_task_tick is called from IRQ context.
986 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
988 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
990 WARN_ON(!irqs_disabled());
992 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
994 list_add(&ctx
->active_ctx_list
, head
);
997 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
999 WARN_ON(!irqs_disabled());
1001 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1003 list_del_init(&ctx
->active_ctx_list
);
1006 static void get_ctx(struct perf_event_context
*ctx
)
1008 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1011 static void free_ctx(struct rcu_head
*head
)
1013 struct perf_event_context
*ctx
;
1015 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1016 kfree(ctx
->task_ctx_data
);
1020 static void put_ctx(struct perf_event_context
*ctx
)
1022 if (atomic_dec_and_test(&ctx
->refcount
)) {
1023 if (ctx
->parent_ctx
)
1024 put_ctx(ctx
->parent_ctx
);
1025 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1026 put_task_struct(ctx
->task
);
1027 call_rcu(&ctx
->rcu_head
, free_ctx
);
1032 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1033 * perf_pmu_migrate_context() we need some magic.
1035 * Those places that change perf_event::ctx will hold both
1036 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1038 * Lock ordering is by mutex address. There are two other sites where
1039 * perf_event_context::mutex nests and those are:
1041 * - perf_event_exit_task_context() [ child , 0 ]
1042 * perf_event_exit_event()
1043 * put_event() [ parent, 1 ]
1045 * - perf_event_init_context() [ parent, 0 ]
1046 * inherit_task_group()
1049 * perf_event_alloc()
1051 * perf_try_init_event() [ child , 1 ]
1053 * While it appears there is an obvious deadlock here -- the parent and child
1054 * nesting levels are inverted between the two. This is in fact safe because
1055 * life-time rules separate them. That is an exiting task cannot fork, and a
1056 * spawning task cannot (yet) exit.
1058 * But remember that that these are parent<->child context relations, and
1059 * migration does not affect children, therefore these two orderings should not
1062 * The change in perf_event::ctx does not affect children (as claimed above)
1063 * because the sys_perf_event_open() case will install a new event and break
1064 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1065 * concerned with cpuctx and that doesn't have children.
1067 * The places that change perf_event::ctx will issue:
1069 * perf_remove_from_context();
1070 * synchronize_rcu();
1071 * perf_install_in_context();
1073 * to affect the change. The remove_from_context() + synchronize_rcu() should
1074 * quiesce the event, after which we can install it in the new location. This
1075 * means that only external vectors (perf_fops, prctl) can perturb the event
1076 * while in transit. Therefore all such accessors should also acquire
1077 * perf_event_context::mutex to serialize against this.
1079 * However; because event->ctx can change while we're waiting to acquire
1080 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1084 * task_struct::perf_event_mutex
1085 * perf_event_context::mutex
1086 * perf_event::child_mutex;
1087 * perf_event_context::lock
1088 * perf_event::mmap_mutex
1091 static struct perf_event_context
*
1092 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1094 struct perf_event_context
*ctx
;
1098 ctx
= ACCESS_ONCE(event
->ctx
);
1099 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1105 mutex_lock_nested(&ctx
->mutex
, nesting
);
1106 if (event
->ctx
!= ctx
) {
1107 mutex_unlock(&ctx
->mutex
);
1115 static inline struct perf_event_context
*
1116 perf_event_ctx_lock(struct perf_event
*event
)
1118 return perf_event_ctx_lock_nested(event
, 0);
1121 static void perf_event_ctx_unlock(struct perf_event
*event
,
1122 struct perf_event_context
*ctx
)
1124 mutex_unlock(&ctx
->mutex
);
1129 * This must be done under the ctx->lock, such as to serialize against
1130 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1131 * calling scheduler related locks and ctx->lock nests inside those.
1133 static __must_check
struct perf_event_context
*
1134 unclone_ctx(struct perf_event_context
*ctx
)
1136 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1138 lockdep_assert_held(&ctx
->lock
);
1141 ctx
->parent_ctx
= NULL
;
1147 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1150 * only top level events have the pid namespace they were created in
1153 event
= event
->parent
;
1155 return task_tgid_nr_ns(p
, event
->ns
);
1158 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1161 * only top level events have the pid namespace they were created in
1164 event
= event
->parent
;
1166 return task_pid_nr_ns(p
, event
->ns
);
1170 * If we inherit events we want to return the parent event id
1173 static u64
primary_event_id(struct perf_event
*event
)
1178 id
= event
->parent
->id
;
1184 * Get the perf_event_context for a task and lock it.
1186 * This has to cope with with the fact that until it is locked,
1187 * the context could get moved to another task.
1189 static struct perf_event_context
*
1190 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1192 struct perf_event_context
*ctx
;
1196 * One of the few rules of preemptible RCU is that one cannot do
1197 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1198 * part of the read side critical section was irqs-enabled -- see
1199 * rcu_read_unlock_special().
1201 * Since ctx->lock nests under rq->lock we must ensure the entire read
1202 * side critical section has interrupts disabled.
1204 local_irq_save(*flags
);
1206 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1209 * If this context is a clone of another, it might
1210 * get swapped for another underneath us by
1211 * perf_event_task_sched_out, though the
1212 * rcu_read_lock() protects us from any context
1213 * getting freed. Lock the context and check if it
1214 * got swapped before we could get the lock, and retry
1215 * if so. If we locked the right context, then it
1216 * can't get swapped on us any more.
1218 raw_spin_lock(&ctx
->lock
);
1219 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1220 raw_spin_unlock(&ctx
->lock
);
1222 local_irq_restore(*flags
);
1226 if (ctx
->task
== TASK_TOMBSTONE
||
1227 !atomic_inc_not_zero(&ctx
->refcount
)) {
1228 raw_spin_unlock(&ctx
->lock
);
1231 WARN_ON_ONCE(ctx
->task
!= task
);
1236 local_irq_restore(*flags
);
1241 * Get the context for a task and increment its pin_count so it
1242 * can't get swapped to another task. This also increments its
1243 * reference count so that the context can't get freed.
1245 static struct perf_event_context
*
1246 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1248 struct perf_event_context
*ctx
;
1249 unsigned long flags
;
1251 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1254 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1259 static void perf_unpin_context(struct perf_event_context
*ctx
)
1261 unsigned long flags
;
1263 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1265 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1269 * Update the record of the current time in a context.
1271 static void update_context_time(struct perf_event_context
*ctx
)
1273 u64 now
= perf_clock();
1275 ctx
->time
+= now
- ctx
->timestamp
;
1276 ctx
->timestamp
= now
;
1279 static u64
perf_event_time(struct perf_event
*event
)
1281 struct perf_event_context
*ctx
= event
->ctx
;
1283 if (is_cgroup_event(event
))
1284 return perf_cgroup_event_time(event
);
1286 return ctx
? ctx
->time
: 0;
1290 * Update the total_time_enabled and total_time_running fields for a event.
1291 * The caller of this function needs to hold the ctx->lock.
1293 static void update_event_times(struct perf_event
*event
)
1295 struct perf_event_context
*ctx
= event
->ctx
;
1298 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1299 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1302 * in cgroup mode, time_enabled represents
1303 * the time the event was enabled AND active
1304 * tasks were in the monitored cgroup. This is
1305 * independent of the activity of the context as
1306 * there may be a mix of cgroup and non-cgroup events.
1308 * That is why we treat cgroup events differently
1311 if (is_cgroup_event(event
))
1312 run_end
= perf_cgroup_event_time(event
);
1313 else if (ctx
->is_active
)
1314 run_end
= ctx
->time
;
1316 run_end
= event
->tstamp_stopped
;
1318 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1320 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1321 run_end
= event
->tstamp_stopped
;
1323 run_end
= perf_event_time(event
);
1325 event
->total_time_running
= run_end
- event
->tstamp_running
;
1330 * Update total_time_enabled and total_time_running for all events in a group.
1332 static void update_group_times(struct perf_event
*leader
)
1334 struct perf_event
*event
;
1336 update_event_times(leader
);
1337 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1338 update_event_times(event
);
1341 static struct list_head
*
1342 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1344 if (event
->attr
.pinned
)
1345 return &ctx
->pinned_groups
;
1347 return &ctx
->flexible_groups
;
1351 * Add a event from the lists for its context.
1352 * Must be called with ctx->mutex and ctx->lock held.
1355 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1357 lockdep_assert_held(&ctx
->lock
);
1359 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1360 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1363 * If we're a stand alone event or group leader, we go to the context
1364 * list, group events are kept attached to the group so that
1365 * perf_group_detach can, at all times, locate all siblings.
1367 if (event
->group_leader
== event
) {
1368 struct list_head
*list
;
1370 if (is_software_event(event
))
1371 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1373 list
= ctx_group_list(event
, ctx
);
1374 list_add_tail(&event
->group_entry
, list
);
1377 if (is_cgroup_event(event
))
1380 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1382 if (event
->attr
.inherit_stat
)
1389 * Initialize event state based on the perf_event_attr::disabled.
1391 static inline void perf_event__state_init(struct perf_event
*event
)
1393 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1394 PERF_EVENT_STATE_INACTIVE
;
1397 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1399 int entry
= sizeof(u64
); /* value */
1403 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1404 size
+= sizeof(u64
);
1406 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1407 size
+= sizeof(u64
);
1409 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1410 entry
+= sizeof(u64
);
1412 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1414 size
+= sizeof(u64
);
1418 event
->read_size
= size
;
1421 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1423 struct perf_sample_data
*data
;
1426 if (sample_type
& PERF_SAMPLE_IP
)
1427 size
+= sizeof(data
->ip
);
1429 if (sample_type
& PERF_SAMPLE_ADDR
)
1430 size
+= sizeof(data
->addr
);
1432 if (sample_type
& PERF_SAMPLE_PERIOD
)
1433 size
+= sizeof(data
->period
);
1435 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1436 size
+= sizeof(data
->weight
);
1438 if (sample_type
& PERF_SAMPLE_READ
)
1439 size
+= event
->read_size
;
1441 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1442 size
+= sizeof(data
->data_src
.val
);
1444 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1445 size
+= sizeof(data
->txn
);
1447 event
->header_size
= size
;
1451 * Called at perf_event creation and when events are attached/detached from a
1454 static void perf_event__header_size(struct perf_event
*event
)
1456 __perf_event_read_size(event
,
1457 event
->group_leader
->nr_siblings
);
1458 __perf_event_header_size(event
, event
->attr
.sample_type
);
1461 static void perf_event__id_header_size(struct perf_event
*event
)
1463 struct perf_sample_data
*data
;
1464 u64 sample_type
= event
->attr
.sample_type
;
1467 if (sample_type
& PERF_SAMPLE_TID
)
1468 size
+= sizeof(data
->tid_entry
);
1470 if (sample_type
& PERF_SAMPLE_TIME
)
1471 size
+= sizeof(data
->time
);
1473 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1474 size
+= sizeof(data
->id
);
1476 if (sample_type
& PERF_SAMPLE_ID
)
1477 size
+= sizeof(data
->id
);
1479 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1480 size
+= sizeof(data
->stream_id
);
1482 if (sample_type
& PERF_SAMPLE_CPU
)
1483 size
+= sizeof(data
->cpu_entry
);
1485 event
->id_header_size
= size
;
1488 static bool perf_event_validate_size(struct perf_event
*event
)
1491 * The values computed here will be over-written when we actually
1494 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1495 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1496 perf_event__id_header_size(event
);
1499 * Sum the lot; should not exceed the 64k limit we have on records.
1500 * Conservative limit to allow for callchains and other variable fields.
1502 if (event
->read_size
+ event
->header_size
+
1503 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1509 static void perf_group_attach(struct perf_event
*event
)
1511 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1514 * We can have double attach due to group movement in perf_event_open.
1516 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1519 event
->attach_state
|= PERF_ATTACH_GROUP
;
1521 if (group_leader
== event
)
1524 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1526 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1527 !is_software_event(event
))
1528 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1530 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1531 group_leader
->nr_siblings
++;
1533 perf_event__header_size(group_leader
);
1535 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1536 perf_event__header_size(pos
);
1540 * Remove a event from the lists for its context.
1541 * Must be called with ctx->mutex and ctx->lock held.
1544 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1546 struct perf_cpu_context
*cpuctx
;
1548 WARN_ON_ONCE(event
->ctx
!= ctx
);
1549 lockdep_assert_held(&ctx
->lock
);
1552 * We can have double detach due to exit/hot-unplug + close.
1554 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1557 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1559 if (is_cgroup_event(event
)) {
1562 * Because cgroup events are always per-cpu events, this will
1563 * always be called from the right CPU.
1565 cpuctx
= __get_cpu_context(ctx
);
1567 * If there are no more cgroup events then clear cgrp to avoid
1568 * stale pointer in update_cgrp_time_from_cpuctx().
1570 if (!ctx
->nr_cgroups
)
1571 cpuctx
->cgrp
= NULL
;
1575 if (event
->attr
.inherit_stat
)
1578 list_del_rcu(&event
->event_entry
);
1580 if (event
->group_leader
== event
)
1581 list_del_init(&event
->group_entry
);
1583 update_group_times(event
);
1586 * If event was in error state, then keep it
1587 * that way, otherwise bogus counts will be
1588 * returned on read(). The only way to get out
1589 * of error state is by explicit re-enabling
1592 if (event
->state
> PERF_EVENT_STATE_OFF
)
1593 event
->state
= PERF_EVENT_STATE_OFF
;
1598 static void perf_group_detach(struct perf_event
*event
)
1600 struct perf_event
*sibling
, *tmp
;
1601 struct list_head
*list
= NULL
;
1604 * We can have double detach due to exit/hot-unplug + close.
1606 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1609 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1612 * If this is a sibling, remove it from its group.
1614 if (event
->group_leader
!= event
) {
1615 list_del_init(&event
->group_entry
);
1616 event
->group_leader
->nr_siblings
--;
1620 if (!list_empty(&event
->group_entry
))
1621 list
= &event
->group_entry
;
1624 * If this was a group event with sibling events then
1625 * upgrade the siblings to singleton events by adding them
1626 * to whatever list we are on.
1628 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1630 list_move_tail(&sibling
->group_entry
, list
);
1631 sibling
->group_leader
= sibling
;
1633 /* Inherit group flags from the previous leader */
1634 sibling
->group_flags
= event
->group_flags
;
1636 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1640 perf_event__header_size(event
->group_leader
);
1642 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1643 perf_event__header_size(tmp
);
1646 static bool is_orphaned_event(struct perf_event
*event
)
1648 return event
->state
== PERF_EVENT_STATE_EXIT
;
1651 static inline int pmu_filter_match(struct perf_event
*event
)
1653 struct pmu
*pmu
= event
->pmu
;
1654 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1658 event_filter_match(struct perf_event
*event
)
1660 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1661 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1665 event_sched_out(struct perf_event
*event
,
1666 struct perf_cpu_context
*cpuctx
,
1667 struct perf_event_context
*ctx
)
1669 u64 tstamp
= perf_event_time(event
);
1672 WARN_ON_ONCE(event
->ctx
!= ctx
);
1673 lockdep_assert_held(&ctx
->lock
);
1676 * An event which could not be activated because of
1677 * filter mismatch still needs to have its timings
1678 * maintained, otherwise bogus information is return
1679 * via read() for time_enabled, time_running:
1681 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1682 && !event_filter_match(event
)) {
1683 delta
= tstamp
- event
->tstamp_stopped
;
1684 event
->tstamp_running
+= delta
;
1685 event
->tstamp_stopped
= tstamp
;
1688 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1691 perf_pmu_disable(event
->pmu
);
1693 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1694 if (event
->pending_disable
) {
1695 event
->pending_disable
= 0;
1696 event
->state
= PERF_EVENT_STATE_OFF
;
1698 event
->tstamp_stopped
= tstamp
;
1699 event
->pmu
->del(event
, 0);
1702 if (!is_software_event(event
))
1703 cpuctx
->active_oncpu
--;
1704 if (!--ctx
->nr_active
)
1705 perf_event_ctx_deactivate(ctx
);
1706 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1708 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1709 cpuctx
->exclusive
= 0;
1711 perf_pmu_enable(event
->pmu
);
1715 group_sched_out(struct perf_event
*group_event
,
1716 struct perf_cpu_context
*cpuctx
,
1717 struct perf_event_context
*ctx
)
1719 struct perf_event
*event
;
1720 int state
= group_event
->state
;
1722 event_sched_out(group_event
, cpuctx
, ctx
);
1725 * Schedule out siblings (if any):
1727 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1728 event_sched_out(event
, cpuctx
, ctx
);
1730 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1731 cpuctx
->exclusive
= 0;
1734 #define DETACH_GROUP 0x01UL
1735 #define DETACH_STATE 0x02UL
1738 * Cross CPU call to remove a performance event
1740 * We disable the event on the hardware level first. After that we
1741 * remove it from the context list.
1744 __perf_remove_from_context(struct perf_event
*event
,
1745 struct perf_cpu_context
*cpuctx
,
1746 struct perf_event_context
*ctx
,
1749 unsigned long flags
= (unsigned long)info
;
1751 event_sched_out(event
, cpuctx
, ctx
);
1752 if (flags
& DETACH_GROUP
)
1753 perf_group_detach(event
);
1754 list_del_event(event
, ctx
);
1755 if (flags
& DETACH_STATE
)
1756 event
->state
= PERF_EVENT_STATE_EXIT
;
1758 if (!ctx
->nr_events
&& ctx
->is_active
) {
1761 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1762 cpuctx
->task_ctx
= NULL
;
1768 * Remove the event from a task's (or a CPU's) list of events.
1770 * If event->ctx is a cloned context, callers must make sure that
1771 * every task struct that event->ctx->task could possibly point to
1772 * remains valid. This is OK when called from perf_release since
1773 * that only calls us on the top-level context, which can't be a clone.
1774 * When called from perf_event_exit_task, it's OK because the
1775 * context has been detached from its task.
1777 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1779 lockdep_assert_held(&event
->ctx
->mutex
);
1781 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1785 * Cross CPU call to disable a performance event
1787 static void __perf_event_disable(struct perf_event
*event
,
1788 struct perf_cpu_context
*cpuctx
,
1789 struct perf_event_context
*ctx
,
1792 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1795 update_context_time(ctx
);
1796 update_cgrp_time_from_event(event
);
1797 update_group_times(event
);
1798 if (event
== event
->group_leader
)
1799 group_sched_out(event
, cpuctx
, ctx
);
1801 event_sched_out(event
, cpuctx
, ctx
);
1802 event
->state
= PERF_EVENT_STATE_OFF
;
1808 * If event->ctx is a cloned context, callers must make sure that
1809 * every task struct that event->ctx->task could possibly point to
1810 * remains valid. This condition is satisifed when called through
1811 * perf_event_for_each_child or perf_event_for_each because they
1812 * hold the top-level event's child_mutex, so any descendant that
1813 * goes to exit will block in perf_event_exit_event().
1815 * When called from perf_pending_event it's OK because event->ctx
1816 * is the current context on this CPU and preemption is disabled,
1817 * hence we can't get into perf_event_task_sched_out for this context.
1819 static void _perf_event_disable(struct perf_event
*event
)
1821 struct perf_event_context
*ctx
= event
->ctx
;
1823 raw_spin_lock_irq(&ctx
->lock
);
1824 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1825 raw_spin_unlock_irq(&ctx
->lock
);
1828 raw_spin_unlock_irq(&ctx
->lock
);
1830 event_function_call(event
, __perf_event_disable
, NULL
);
1833 void perf_event_disable_local(struct perf_event
*event
)
1835 event_function_local(event
, __perf_event_disable
, NULL
);
1839 * Strictly speaking kernel users cannot create groups and therefore this
1840 * interface does not need the perf_event_ctx_lock() magic.
1842 void perf_event_disable(struct perf_event
*event
)
1844 struct perf_event_context
*ctx
;
1846 ctx
= perf_event_ctx_lock(event
);
1847 _perf_event_disable(event
);
1848 perf_event_ctx_unlock(event
, ctx
);
1850 EXPORT_SYMBOL_GPL(perf_event_disable
);
1852 static void perf_set_shadow_time(struct perf_event
*event
,
1853 struct perf_event_context
*ctx
,
1857 * use the correct time source for the time snapshot
1859 * We could get by without this by leveraging the
1860 * fact that to get to this function, the caller
1861 * has most likely already called update_context_time()
1862 * and update_cgrp_time_xx() and thus both timestamp
1863 * are identical (or very close). Given that tstamp is,
1864 * already adjusted for cgroup, we could say that:
1865 * tstamp - ctx->timestamp
1867 * tstamp - cgrp->timestamp.
1869 * Then, in perf_output_read(), the calculation would
1870 * work with no changes because:
1871 * - event is guaranteed scheduled in
1872 * - no scheduled out in between
1873 * - thus the timestamp would be the same
1875 * But this is a bit hairy.
1877 * So instead, we have an explicit cgroup call to remain
1878 * within the time time source all along. We believe it
1879 * is cleaner and simpler to understand.
1881 if (is_cgroup_event(event
))
1882 perf_cgroup_set_shadow_time(event
, tstamp
);
1884 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1887 #define MAX_INTERRUPTS (~0ULL)
1889 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1890 static void perf_log_itrace_start(struct perf_event
*event
);
1893 event_sched_in(struct perf_event
*event
,
1894 struct perf_cpu_context
*cpuctx
,
1895 struct perf_event_context
*ctx
)
1897 u64 tstamp
= perf_event_time(event
);
1900 lockdep_assert_held(&ctx
->lock
);
1902 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1905 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1906 event
->oncpu
= smp_processor_id();
1909 * Unthrottle events, since we scheduled we might have missed several
1910 * ticks already, also for a heavily scheduling task there is little
1911 * guarantee it'll get a tick in a timely manner.
1913 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1914 perf_log_throttle(event
, 1);
1915 event
->hw
.interrupts
= 0;
1919 * The new state must be visible before we turn it on in the hardware:
1923 perf_pmu_disable(event
->pmu
);
1925 perf_set_shadow_time(event
, ctx
, tstamp
);
1927 perf_log_itrace_start(event
);
1929 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1930 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1936 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1938 if (!is_software_event(event
))
1939 cpuctx
->active_oncpu
++;
1940 if (!ctx
->nr_active
++)
1941 perf_event_ctx_activate(ctx
);
1942 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1945 if (event
->attr
.exclusive
)
1946 cpuctx
->exclusive
= 1;
1949 perf_pmu_enable(event
->pmu
);
1955 group_sched_in(struct perf_event
*group_event
,
1956 struct perf_cpu_context
*cpuctx
,
1957 struct perf_event_context
*ctx
)
1959 struct perf_event
*event
, *partial_group
= NULL
;
1960 struct pmu
*pmu
= ctx
->pmu
;
1961 u64 now
= ctx
->time
;
1962 bool simulate
= false;
1964 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1967 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
1969 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1970 pmu
->cancel_txn(pmu
);
1971 perf_mux_hrtimer_restart(cpuctx
);
1976 * Schedule in siblings as one group (if any):
1978 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1979 if (event_sched_in(event
, cpuctx
, ctx
)) {
1980 partial_group
= event
;
1985 if (!pmu
->commit_txn(pmu
))
1990 * Groups can be scheduled in as one unit only, so undo any
1991 * partial group before returning:
1992 * The events up to the failed event are scheduled out normally,
1993 * tstamp_stopped will be updated.
1995 * The failed events and the remaining siblings need to have
1996 * their timings updated as if they had gone thru event_sched_in()
1997 * and event_sched_out(). This is required to get consistent timings
1998 * across the group. This also takes care of the case where the group
1999 * could never be scheduled by ensuring tstamp_stopped is set to mark
2000 * the time the event was actually stopped, such that time delta
2001 * calculation in update_event_times() is correct.
2003 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2004 if (event
== partial_group
)
2008 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2009 event
->tstamp_stopped
= now
;
2011 event_sched_out(event
, cpuctx
, ctx
);
2014 event_sched_out(group_event
, cpuctx
, ctx
);
2016 pmu
->cancel_txn(pmu
);
2018 perf_mux_hrtimer_restart(cpuctx
);
2024 * Work out whether we can put this event group on the CPU now.
2026 static int group_can_go_on(struct perf_event
*event
,
2027 struct perf_cpu_context
*cpuctx
,
2031 * Groups consisting entirely of software events can always go on.
2033 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2036 * If an exclusive group is already on, no other hardware
2039 if (cpuctx
->exclusive
)
2042 * If this group is exclusive and there are already
2043 * events on the CPU, it can't go on.
2045 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2048 * Otherwise, try to add it if all previous groups were able
2054 static void add_event_to_ctx(struct perf_event
*event
,
2055 struct perf_event_context
*ctx
)
2057 u64 tstamp
= perf_event_time(event
);
2059 list_add_event(event
, ctx
);
2060 perf_group_attach(event
);
2061 event
->tstamp_enabled
= tstamp
;
2062 event
->tstamp_running
= tstamp
;
2063 event
->tstamp_stopped
= tstamp
;
2066 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2067 struct perf_event_context
*ctx
);
2069 ctx_sched_in(struct perf_event_context
*ctx
,
2070 struct perf_cpu_context
*cpuctx
,
2071 enum event_type_t event_type
,
2072 struct task_struct
*task
);
2074 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2075 struct perf_event_context
*ctx
,
2076 struct task_struct
*task
)
2078 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2080 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2081 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2083 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2086 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2087 struct perf_event_context
*task_ctx
)
2089 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2091 task_ctx_sched_out(cpuctx
, task_ctx
);
2092 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2093 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2094 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2098 * Cross CPU call to install and enable a performance event
2100 * Must be called with ctx->mutex held
2102 static int __perf_install_in_context(void *info
)
2104 struct perf_event_context
*ctx
= info
;
2105 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2106 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2108 raw_spin_lock(&cpuctx
->ctx
.lock
);
2110 raw_spin_lock(&ctx
->lock
);
2112 * If we hit the 'wrong' task, we've since scheduled and
2113 * everything should be sorted, nothing to do!
2116 if (ctx
->task
!= current
)
2120 * If task_ctx is set, it had better be to us.
2122 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
&& cpuctx
->task_ctx
);
2123 } else if (task_ctx
) {
2124 raw_spin_lock(&task_ctx
->lock
);
2127 ctx_resched(cpuctx
, task_ctx
);
2129 perf_ctx_unlock(cpuctx
, task_ctx
);
2135 * Attach a performance event to a context
2138 perf_install_in_context(struct perf_event_context
*ctx
,
2139 struct perf_event
*event
,
2142 struct task_struct
*task
= NULL
;
2144 lockdep_assert_held(&ctx
->mutex
);
2147 if (event
->cpu
!= -1)
2151 * Installing events is tricky because we cannot rely on ctx->is_active
2152 * to be set in case this is the nr_events 0 -> 1 transition.
2154 * So what we do is we add the event to the list here, which will allow
2155 * a future context switch to DTRT and then send a racy IPI. If the IPI
2156 * fails to hit the right task, this means a context switch must have
2157 * happened and that will have taken care of business.
2159 raw_spin_lock_irq(&ctx
->lock
);
2162 * Worse, we cannot even rely on the ctx actually existing anymore. If
2163 * between find_get_context() and perf_install_in_context() the task
2164 * went through perf_event_exit_task() its dead and we should not be
2165 * adding new events.
2167 if (task
== TASK_TOMBSTONE
) {
2168 raw_spin_unlock_irq(&ctx
->lock
);
2171 update_context_time(ctx
);
2173 * Update cgrp time only if current cgrp matches event->cgrp.
2174 * Must be done before calling add_event_to_ctx().
2176 update_cgrp_time_from_event(event
);
2177 add_event_to_ctx(event
, ctx
);
2178 raw_spin_unlock_irq(&ctx
->lock
);
2181 task_function_call(task
, __perf_install_in_context
, ctx
);
2183 cpu_function_call(cpu
, __perf_install_in_context
, ctx
);
2187 * Put a event into inactive state and update time fields.
2188 * Enabling the leader of a group effectively enables all
2189 * the group members that aren't explicitly disabled, so we
2190 * have to update their ->tstamp_enabled also.
2191 * Note: this works for group members as well as group leaders
2192 * since the non-leader members' sibling_lists will be empty.
2194 static void __perf_event_mark_enabled(struct perf_event
*event
)
2196 struct perf_event
*sub
;
2197 u64 tstamp
= perf_event_time(event
);
2199 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2200 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2201 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2202 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2203 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2208 * Cross CPU call to enable a performance event
2210 static void __perf_event_enable(struct perf_event
*event
,
2211 struct perf_cpu_context
*cpuctx
,
2212 struct perf_event_context
*ctx
,
2215 struct perf_event
*leader
= event
->group_leader
;
2216 struct perf_event_context
*task_ctx
;
2218 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2219 event
->state
<= PERF_EVENT_STATE_ERROR
)
2222 update_context_time(ctx
);
2223 __perf_event_mark_enabled(event
);
2225 if (!ctx
->is_active
)
2228 if (!event_filter_match(event
)) {
2229 if (is_cgroup_event(event
)) {
2230 perf_cgroup_set_timestamp(current
, ctx
); // XXX ?
2231 perf_cgroup_defer_enabled(event
);
2237 * If the event is in a group and isn't the group leader,
2238 * then don't put it on unless the group is on.
2240 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2243 task_ctx
= cpuctx
->task_ctx
;
2245 WARN_ON_ONCE(task_ctx
!= ctx
);
2247 ctx_resched(cpuctx
, task_ctx
);
2253 * If event->ctx is a cloned context, callers must make sure that
2254 * every task struct that event->ctx->task could possibly point to
2255 * remains valid. This condition is satisfied when called through
2256 * perf_event_for_each_child or perf_event_for_each as described
2257 * for perf_event_disable.
2259 static void _perf_event_enable(struct perf_event
*event
)
2261 struct perf_event_context
*ctx
= event
->ctx
;
2263 raw_spin_lock_irq(&ctx
->lock
);
2264 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2265 event
->state
< PERF_EVENT_STATE_ERROR
) {
2266 raw_spin_unlock_irq(&ctx
->lock
);
2271 * If the event is in error state, clear that first.
2273 * That way, if we see the event in error state below, we know that it
2274 * has gone back into error state, as distinct from the task having
2275 * been scheduled away before the cross-call arrived.
2277 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2278 event
->state
= PERF_EVENT_STATE_OFF
;
2279 raw_spin_unlock_irq(&ctx
->lock
);
2281 event_function_call(event
, __perf_event_enable
, NULL
);
2285 * See perf_event_disable();
2287 void perf_event_enable(struct perf_event
*event
)
2289 struct perf_event_context
*ctx
;
2291 ctx
= perf_event_ctx_lock(event
);
2292 _perf_event_enable(event
);
2293 perf_event_ctx_unlock(event
, ctx
);
2295 EXPORT_SYMBOL_GPL(perf_event_enable
);
2297 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2300 * not supported on inherited events
2302 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2305 atomic_add(refresh
, &event
->event_limit
);
2306 _perf_event_enable(event
);
2312 * See perf_event_disable()
2314 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2316 struct perf_event_context
*ctx
;
2319 ctx
= perf_event_ctx_lock(event
);
2320 ret
= _perf_event_refresh(event
, refresh
);
2321 perf_event_ctx_unlock(event
, ctx
);
2325 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2327 static void ctx_sched_out(struct perf_event_context
*ctx
,
2328 struct perf_cpu_context
*cpuctx
,
2329 enum event_type_t event_type
)
2331 int is_active
= ctx
->is_active
;
2332 struct perf_event
*event
;
2334 lockdep_assert_held(&ctx
->lock
);
2336 if (likely(!ctx
->nr_events
)) {
2338 * See __perf_remove_from_context().
2340 WARN_ON_ONCE(ctx
->is_active
);
2342 WARN_ON_ONCE(cpuctx
->task_ctx
);
2346 ctx
->is_active
&= ~event_type
;
2348 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2349 if (!ctx
->is_active
)
2350 cpuctx
->task_ctx
= NULL
;
2353 update_context_time(ctx
);
2354 update_cgrp_time_from_cpuctx(cpuctx
);
2355 if (!ctx
->nr_active
)
2358 perf_pmu_disable(ctx
->pmu
);
2359 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2360 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2361 group_sched_out(event
, cpuctx
, ctx
);
2364 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2365 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2366 group_sched_out(event
, cpuctx
, ctx
);
2368 perf_pmu_enable(ctx
->pmu
);
2372 * Test whether two contexts are equivalent, i.e. whether they have both been
2373 * cloned from the same version of the same context.
2375 * Equivalence is measured using a generation number in the context that is
2376 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2377 * and list_del_event().
2379 static int context_equiv(struct perf_event_context
*ctx1
,
2380 struct perf_event_context
*ctx2
)
2382 lockdep_assert_held(&ctx1
->lock
);
2383 lockdep_assert_held(&ctx2
->lock
);
2385 /* Pinning disables the swap optimization */
2386 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2389 /* If ctx1 is the parent of ctx2 */
2390 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2393 /* If ctx2 is the parent of ctx1 */
2394 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2398 * If ctx1 and ctx2 have the same parent; we flatten the parent
2399 * hierarchy, see perf_event_init_context().
2401 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2402 ctx1
->parent_gen
== ctx2
->parent_gen
)
2409 static void __perf_event_sync_stat(struct perf_event
*event
,
2410 struct perf_event
*next_event
)
2414 if (!event
->attr
.inherit_stat
)
2418 * Update the event value, we cannot use perf_event_read()
2419 * because we're in the middle of a context switch and have IRQs
2420 * disabled, which upsets smp_call_function_single(), however
2421 * we know the event must be on the current CPU, therefore we
2422 * don't need to use it.
2424 switch (event
->state
) {
2425 case PERF_EVENT_STATE_ACTIVE
:
2426 event
->pmu
->read(event
);
2429 case PERF_EVENT_STATE_INACTIVE
:
2430 update_event_times(event
);
2438 * In order to keep per-task stats reliable we need to flip the event
2439 * values when we flip the contexts.
2441 value
= local64_read(&next_event
->count
);
2442 value
= local64_xchg(&event
->count
, value
);
2443 local64_set(&next_event
->count
, value
);
2445 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2446 swap(event
->total_time_running
, next_event
->total_time_running
);
2449 * Since we swizzled the values, update the user visible data too.
2451 perf_event_update_userpage(event
);
2452 perf_event_update_userpage(next_event
);
2455 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2456 struct perf_event_context
*next_ctx
)
2458 struct perf_event
*event
, *next_event
;
2463 update_context_time(ctx
);
2465 event
= list_first_entry(&ctx
->event_list
,
2466 struct perf_event
, event_entry
);
2468 next_event
= list_first_entry(&next_ctx
->event_list
,
2469 struct perf_event
, event_entry
);
2471 while (&event
->event_entry
!= &ctx
->event_list
&&
2472 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2474 __perf_event_sync_stat(event
, next_event
);
2476 event
= list_next_entry(event
, event_entry
);
2477 next_event
= list_next_entry(next_event
, event_entry
);
2481 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2482 struct task_struct
*next
)
2484 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2485 struct perf_event_context
*next_ctx
;
2486 struct perf_event_context
*parent
, *next_parent
;
2487 struct perf_cpu_context
*cpuctx
;
2493 cpuctx
= __get_cpu_context(ctx
);
2494 if (!cpuctx
->task_ctx
)
2498 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2502 parent
= rcu_dereference(ctx
->parent_ctx
);
2503 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2505 /* If neither context have a parent context; they cannot be clones. */
2506 if (!parent
&& !next_parent
)
2509 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2511 * Looks like the two contexts are clones, so we might be
2512 * able to optimize the context switch. We lock both
2513 * contexts and check that they are clones under the
2514 * lock (including re-checking that neither has been
2515 * uncloned in the meantime). It doesn't matter which
2516 * order we take the locks because no other cpu could
2517 * be trying to lock both of these tasks.
2519 raw_spin_lock(&ctx
->lock
);
2520 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2521 if (context_equiv(ctx
, next_ctx
)) {
2522 WRITE_ONCE(ctx
->task
, next
);
2523 WRITE_ONCE(next_ctx
->task
, task
);
2525 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2528 * RCU_INIT_POINTER here is safe because we've not
2529 * modified the ctx and the above modification of
2530 * ctx->task and ctx->task_ctx_data are immaterial
2531 * since those values are always verified under
2532 * ctx->lock which we're now holding.
2534 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2535 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2539 perf_event_sync_stat(ctx
, next_ctx
);
2541 raw_spin_unlock(&next_ctx
->lock
);
2542 raw_spin_unlock(&ctx
->lock
);
2548 raw_spin_lock(&ctx
->lock
);
2549 task_ctx_sched_out(cpuctx
, ctx
);
2550 raw_spin_unlock(&ctx
->lock
);
2554 void perf_sched_cb_dec(struct pmu
*pmu
)
2556 this_cpu_dec(perf_sched_cb_usages
);
2559 void perf_sched_cb_inc(struct pmu
*pmu
)
2561 this_cpu_inc(perf_sched_cb_usages
);
2565 * This function provides the context switch callback to the lower code
2566 * layer. It is invoked ONLY when the context switch callback is enabled.
2568 static void perf_pmu_sched_task(struct task_struct
*prev
,
2569 struct task_struct
*next
,
2572 struct perf_cpu_context
*cpuctx
;
2574 unsigned long flags
;
2579 local_irq_save(flags
);
2583 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2584 if (pmu
->sched_task
) {
2585 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2587 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2589 perf_pmu_disable(pmu
);
2591 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2593 perf_pmu_enable(pmu
);
2595 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2601 local_irq_restore(flags
);
2604 static void perf_event_switch(struct task_struct
*task
,
2605 struct task_struct
*next_prev
, bool sched_in
);
2607 #define for_each_task_context_nr(ctxn) \
2608 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2611 * Called from scheduler to remove the events of the current task,
2612 * with interrupts disabled.
2614 * We stop each event and update the event value in event->count.
2616 * This does not protect us against NMI, but disable()
2617 * sets the disabled bit in the control field of event _before_
2618 * accessing the event control register. If a NMI hits, then it will
2619 * not restart the event.
2621 void __perf_event_task_sched_out(struct task_struct
*task
,
2622 struct task_struct
*next
)
2626 if (__this_cpu_read(perf_sched_cb_usages
))
2627 perf_pmu_sched_task(task
, next
, false);
2629 if (atomic_read(&nr_switch_events
))
2630 perf_event_switch(task
, next
, false);
2632 for_each_task_context_nr(ctxn
)
2633 perf_event_context_sched_out(task
, ctxn
, next
);
2636 * if cgroup events exist on this CPU, then we need
2637 * to check if we have to switch out PMU state.
2638 * cgroup event are system-wide mode only
2640 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2641 perf_cgroup_sched_out(task
, next
);
2644 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2645 struct perf_event_context
*ctx
)
2647 if (!cpuctx
->task_ctx
)
2650 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2653 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2657 * Called with IRQs disabled
2659 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2660 enum event_type_t event_type
)
2662 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2666 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2667 struct perf_cpu_context
*cpuctx
)
2669 struct perf_event
*event
;
2671 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2672 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2674 if (!event_filter_match(event
))
2677 /* may need to reset tstamp_enabled */
2678 if (is_cgroup_event(event
))
2679 perf_cgroup_mark_enabled(event
, ctx
);
2681 if (group_can_go_on(event
, cpuctx
, 1))
2682 group_sched_in(event
, cpuctx
, ctx
);
2685 * If this pinned group hasn't been scheduled,
2686 * put it in error state.
2688 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2689 update_group_times(event
);
2690 event
->state
= PERF_EVENT_STATE_ERROR
;
2696 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2697 struct perf_cpu_context
*cpuctx
)
2699 struct perf_event
*event
;
2702 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2703 /* Ignore events in OFF or ERROR state */
2704 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2707 * Listen to the 'cpu' scheduling filter constraint
2710 if (!event_filter_match(event
))
2713 /* may need to reset tstamp_enabled */
2714 if (is_cgroup_event(event
))
2715 perf_cgroup_mark_enabled(event
, ctx
);
2717 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2718 if (group_sched_in(event
, cpuctx
, ctx
))
2725 ctx_sched_in(struct perf_event_context
*ctx
,
2726 struct perf_cpu_context
*cpuctx
,
2727 enum event_type_t event_type
,
2728 struct task_struct
*task
)
2730 int is_active
= ctx
->is_active
;
2733 lockdep_assert_held(&ctx
->lock
);
2735 if (likely(!ctx
->nr_events
))
2738 ctx
->is_active
|= event_type
;
2741 cpuctx
->task_ctx
= ctx
;
2743 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2747 ctx
->timestamp
= now
;
2748 perf_cgroup_set_timestamp(task
, ctx
);
2750 * First go through the list and put on any pinned groups
2751 * in order to give them the best chance of going on.
2753 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2754 ctx_pinned_sched_in(ctx
, cpuctx
);
2756 /* Then walk through the lower prio flexible groups */
2757 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2758 ctx_flexible_sched_in(ctx
, cpuctx
);
2761 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2762 enum event_type_t event_type
,
2763 struct task_struct
*task
)
2765 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2767 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2770 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2771 struct task_struct
*task
)
2773 struct perf_cpu_context
*cpuctx
;
2775 cpuctx
= __get_cpu_context(ctx
);
2776 if (cpuctx
->task_ctx
== ctx
)
2779 perf_ctx_lock(cpuctx
, ctx
);
2780 perf_pmu_disable(ctx
->pmu
);
2782 * We want to keep the following priority order:
2783 * cpu pinned (that don't need to move), task pinned,
2784 * cpu flexible, task flexible.
2786 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2787 perf_event_sched_in(cpuctx
, ctx
, task
);
2788 perf_pmu_enable(ctx
->pmu
);
2789 perf_ctx_unlock(cpuctx
, ctx
);
2793 * Called from scheduler to add the events of the current task
2794 * with interrupts disabled.
2796 * We restore the event value and then enable it.
2798 * This does not protect us against NMI, but enable()
2799 * sets the enabled bit in the control field of event _before_
2800 * accessing the event control register. If a NMI hits, then it will
2801 * keep the event running.
2803 void __perf_event_task_sched_in(struct task_struct
*prev
,
2804 struct task_struct
*task
)
2806 struct perf_event_context
*ctx
;
2810 * If cgroup events exist on this CPU, then we need to check if we have
2811 * to switch in PMU state; cgroup event are system-wide mode only.
2813 * Since cgroup events are CPU events, we must schedule these in before
2814 * we schedule in the task events.
2816 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2817 perf_cgroup_sched_in(prev
, task
);
2819 for_each_task_context_nr(ctxn
) {
2820 ctx
= task
->perf_event_ctxp
[ctxn
];
2824 perf_event_context_sched_in(ctx
, task
);
2827 if (atomic_read(&nr_switch_events
))
2828 perf_event_switch(task
, prev
, true);
2830 if (__this_cpu_read(perf_sched_cb_usages
))
2831 perf_pmu_sched_task(prev
, task
, true);
2834 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2836 u64 frequency
= event
->attr
.sample_freq
;
2837 u64 sec
= NSEC_PER_SEC
;
2838 u64 divisor
, dividend
;
2840 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2842 count_fls
= fls64(count
);
2843 nsec_fls
= fls64(nsec
);
2844 frequency_fls
= fls64(frequency
);
2848 * We got @count in @nsec, with a target of sample_freq HZ
2849 * the target period becomes:
2852 * period = -------------------
2853 * @nsec * sample_freq
2858 * Reduce accuracy by one bit such that @a and @b converge
2859 * to a similar magnitude.
2861 #define REDUCE_FLS(a, b) \
2863 if (a##_fls > b##_fls) { \
2873 * Reduce accuracy until either term fits in a u64, then proceed with
2874 * the other, so that finally we can do a u64/u64 division.
2876 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2877 REDUCE_FLS(nsec
, frequency
);
2878 REDUCE_FLS(sec
, count
);
2881 if (count_fls
+ sec_fls
> 64) {
2882 divisor
= nsec
* frequency
;
2884 while (count_fls
+ sec_fls
> 64) {
2885 REDUCE_FLS(count
, sec
);
2889 dividend
= count
* sec
;
2891 dividend
= count
* sec
;
2893 while (nsec_fls
+ frequency_fls
> 64) {
2894 REDUCE_FLS(nsec
, frequency
);
2898 divisor
= nsec
* frequency
;
2904 return div64_u64(dividend
, divisor
);
2907 static DEFINE_PER_CPU(int, perf_throttled_count
);
2908 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2910 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2912 struct hw_perf_event
*hwc
= &event
->hw
;
2913 s64 period
, sample_period
;
2916 period
= perf_calculate_period(event
, nsec
, count
);
2918 delta
= (s64
)(period
- hwc
->sample_period
);
2919 delta
= (delta
+ 7) / 8; /* low pass filter */
2921 sample_period
= hwc
->sample_period
+ delta
;
2926 hwc
->sample_period
= sample_period
;
2928 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2930 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2932 local64_set(&hwc
->period_left
, 0);
2935 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2940 * combine freq adjustment with unthrottling to avoid two passes over the
2941 * events. At the same time, make sure, having freq events does not change
2942 * the rate of unthrottling as that would introduce bias.
2944 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2947 struct perf_event
*event
;
2948 struct hw_perf_event
*hwc
;
2949 u64 now
, period
= TICK_NSEC
;
2953 * only need to iterate over all events iff:
2954 * - context have events in frequency mode (needs freq adjust)
2955 * - there are events to unthrottle on this cpu
2957 if (!(ctx
->nr_freq
|| needs_unthr
))
2960 raw_spin_lock(&ctx
->lock
);
2961 perf_pmu_disable(ctx
->pmu
);
2963 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2964 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2967 if (!event_filter_match(event
))
2970 perf_pmu_disable(event
->pmu
);
2974 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
2975 hwc
->interrupts
= 0;
2976 perf_log_throttle(event
, 1);
2977 event
->pmu
->start(event
, 0);
2980 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2984 * stop the event and update event->count
2986 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2988 now
= local64_read(&event
->count
);
2989 delta
= now
- hwc
->freq_count_stamp
;
2990 hwc
->freq_count_stamp
= now
;
2994 * reload only if value has changed
2995 * we have stopped the event so tell that
2996 * to perf_adjust_period() to avoid stopping it
3000 perf_adjust_period(event
, period
, delta
, false);
3002 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3004 perf_pmu_enable(event
->pmu
);
3007 perf_pmu_enable(ctx
->pmu
);
3008 raw_spin_unlock(&ctx
->lock
);
3012 * Round-robin a context's events:
3014 static void rotate_ctx(struct perf_event_context
*ctx
)
3017 * Rotate the first entry last of non-pinned groups. Rotation might be
3018 * disabled by the inheritance code.
3020 if (!ctx
->rotate_disable
)
3021 list_rotate_left(&ctx
->flexible_groups
);
3024 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3026 struct perf_event_context
*ctx
= NULL
;
3029 if (cpuctx
->ctx
.nr_events
) {
3030 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3034 ctx
= cpuctx
->task_ctx
;
3035 if (ctx
&& ctx
->nr_events
) {
3036 if (ctx
->nr_events
!= ctx
->nr_active
)
3043 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3044 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3046 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3048 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3050 rotate_ctx(&cpuctx
->ctx
);
3054 perf_event_sched_in(cpuctx
, ctx
, current
);
3056 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3057 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3063 #ifdef CONFIG_NO_HZ_FULL
3064 bool perf_event_can_stop_tick(void)
3066 if (atomic_read(&nr_freq_events
) ||
3067 __this_cpu_read(perf_throttled_count
))
3074 void perf_event_task_tick(void)
3076 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3077 struct perf_event_context
*ctx
, *tmp
;
3080 WARN_ON(!irqs_disabled());
3082 __this_cpu_inc(perf_throttled_seq
);
3083 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3085 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3086 perf_adjust_freq_unthr_context(ctx
, throttled
);
3089 static int event_enable_on_exec(struct perf_event
*event
,
3090 struct perf_event_context
*ctx
)
3092 if (!event
->attr
.enable_on_exec
)
3095 event
->attr
.enable_on_exec
= 0;
3096 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3099 __perf_event_mark_enabled(event
);
3105 * Enable all of a task's events that have been marked enable-on-exec.
3106 * This expects task == current.
3108 static void perf_event_enable_on_exec(int ctxn
)
3110 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3111 struct perf_cpu_context
*cpuctx
;
3112 struct perf_event
*event
;
3113 unsigned long flags
;
3116 local_irq_save(flags
);
3117 ctx
= current
->perf_event_ctxp
[ctxn
];
3118 if (!ctx
|| !ctx
->nr_events
)
3121 cpuctx
= __get_cpu_context(ctx
);
3122 perf_ctx_lock(cpuctx
, ctx
);
3123 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
3124 enabled
|= event_enable_on_exec(event
, ctx
);
3127 * Unclone and reschedule this context if we enabled any event.
3130 clone_ctx
= unclone_ctx(ctx
);
3131 ctx_resched(cpuctx
, ctx
);
3133 perf_ctx_unlock(cpuctx
, ctx
);
3136 local_irq_restore(flags
);
3142 void perf_event_exec(void)
3147 for_each_task_context_nr(ctxn
)
3148 perf_event_enable_on_exec(ctxn
);
3152 struct perf_read_data
{
3153 struct perf_event
*event
;
3159 * Cross CPU call to read the hardware event
3161 static void __perf_event_read(void *info
)
3163 struct perf_read_data
*data
= info
;
3164 struct perf_event
*sub
, *event
= data
->event
;
3165 struct perf_event_context
*ctx
= event
->ctx
;
3166 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3167 struct pmu
*pmu
= event
->pmu
;
3170 * If this is a task context, we need to check whether it is
3171 * the current task context of this cpu. If not it has been
3172 * scheduled out before the smp call arrived. In that case
3173 * event->count would have been updated to a recent sample
3174 * when the event was scheduled out.
3176 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3179 raw_spin_lock(&ctx
->lock
);
3180 if (ctx
->is_active
) {
3181 update_context_time(ctx
);
3182 update_cgrp_time_from_event(event
);
3185 update_event_times(event
);
3186 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3195 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3199 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3200 update_event_times(sub
);
3201 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3203 * Use sibling's PMU rather than @event's since
3204 * sibling could be on different (eg: software) PMU.
3206 sub
->pmu
->read(sub
);
3210 data
->ret
= pmu
->commit_txn(pmu
);
3213 raw_spin_unlock(&ctx
->lock
);
3216 static inline u64
perf_event_count(struct perf_event
*event
)
3218 if (event
->pmu
->count
)
3219 return event
->pmu
->count(event
);
3221 return __perf_event_count(event
);
3225 * NMI-safe method to read a local event, that is an event that
3227 * - either for the current task, or for this CPU
3228 * - does not have inherit set, for inherited task events
3229 * will not be local and we cannot read them atomically
3230 * - must not have a pmu::count method
3232 u64
perf_event_read_local(struct perf_event
*event
)
3234 unsigned long flags
;
3238 * Disabling interrupts avoids all counter scheduling (context
3239 * switches, timer based rotation and IPIs).
3241 local_irq_save(flags
);
3243 /* If this is a per-task event, it must be for current */
3244 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3245 event
->hw
.target
!= current
);
3247 /* If this is a per-CPU event, it must be for this CPU */
3248 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3249 event
->cpu
!= smp_processor_id());
3252 * It must not be an event with inherit set, we cannot read
3253 * all child counters from atomic context.
3255 WARN_ON_ONCE(event
->attr
.inherit
);
3258 * It must not have a pmu::count method, those are not
3261 WARN_ON_ONCE(event
->pmu
->count
);
3264 * If the event is currently on this CPU, its either a per-task event,
3265 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3268 if (event
->oncpu
== smp_processor_id())
3269 event
->pmu
->read(event
);
3271 val
= local64_read(&event
->count
);
3272 local_irq_restore(flags
);
3277 static int perf_event_read(struct perf_event
*event
, bool group
)
3282 * If event is enabled and currently active on a CPU, update the
3283 * value in the event structure:
3285 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3286 struct perf_read_data data
= {
3291 smp_call_function_single(event
->oncpu
,
3292 __perf_event_read
, &data
, 1);
3294 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3295 struct perf_event_context
*ctx
= event
->ctx
;
3296 unsigned long flags
;
3298 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3300 * may read while context is not active
3301 * (e.g., thread is blocked), in that case
3302 * we cannot update context time
3304 if (ctx
->is_active
) {
3305 update_context_time(ctx
);
3306 update_cgrp_time_from_event(event
);
3309 update_group_times(event
);
3311 update_event_times(event
);
3312 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3319 * Initialize the perf_event context in a task_struct:
3321 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3323 raw_spin_lock_init(&ctx
->lock
);
3324 mutex_init(&ctx
->mutex
);
3325 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3326 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3327 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3328 INIT_LIST_HEAD(&ctx
->event_list
);
3329 atomic_set(&ctx
->refcount
, 1);
3332 static struct perf_event_context
*
3333 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3335 struct perf_event_context
*ctx
;
3337 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3341 __perf_event_init_context(ctx
);
3344 get_task_struct(task
);
3351 static struct task_struct
*
3352 find_lively_task_by_vpid(pid_t vpid
)
3354 struct task_struct
*task
;
3361 task
= find_task_by_vpid(vpid
);
3363 get_task_struct(task
);
3367 return ERR_PTR(-ESRCH
);
3369 /* Reuse ptrace permission checks for now. */
3371 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
3376 put_task_struct(task
);
3377 return ERR_PTR(err
);
3382 * Returns a matching context with refcount and pincount.
3384 static struct perf_event_context
*
3385 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3386 struct perf_event
*event
)
3388 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3389 struct perf_cpu_context
*cpuctx
;
3390 void *task_ctx_data
= NULL
;
3391 unsigned long flags
;
3393 int cpu
= event
->cpu
;
3396 /* Must be root to operate on a CPU event: */
3397 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3398 return ERR_PTR(-EACCES
);
3401 * We could be clever and allow to attach a event to an
3402 * offline CPU and activate it when the CPU comes up, but
3405 if (!cpu_online(cpu
))
3406 return ERR_PTR(-ENODEV
);
3408 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3417 ctxn
= pmu
->task_ctx_nr
;
3421 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3422 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3423 if (!task_ctx_data
) {
3430 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3432 clone_ctx
= unclone_ctx(ctx
);
3435 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3436 ctx
->task_ctx_data
= task_ctx_data
;
3437 task_ctx_data
= NULL
;
3439 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3444 ctx
= alloc_perf_context(pmu
, task
);
3449 if (task_ctx_data
) {
3450 ctx
->task_ctx_data
= task_ctx_data
;
3451 task_ctx_data
= NULL
;
3455 mutex_lock(&task
->perf_event_mutex
);
3457 * If it has already passed perf_event_exit_task().
3458 * we must see PF_EXITING, it takes this mutex too.
3460 if (task
->flags
& PF_EXITING
)
3462 else if (task
->perf_event_ctxp
[ctxn
])
3467 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3469 mutex_unlock(&task
->perf_event_mutex
);
3471 if (unlikely(err
)) {
3480 kfree(task_ctx_data
);
3484 kfree(task_ctx_data
);
3485 return ERR_PTR(err
);
3488 static void perf_event_free_filter(struct perf_event
*event
);
3489 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3491 static void free_event_rcu(struct rcu_head
*head
)
3493 struct perf_event
*event
;
3495 event
= container_of(head
, struct perf_event
, rcu_head
);
3497 put_pid_ns(event
->ns
);
3498 perf_event_free_filter(event
);
3502 static void ring_buffer_attach(struct perf_event
*event
,
3503 struct ring_buffer
*rb
);
3505 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3510 if (is_cgroup_event(event
))
3511 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3514 static void unaccount_event(struct perf_event
*event
)
3521 if (event
->attach_state
& PERF_ATTACH_TASK
)
3523 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3524 atomic_dec(&nr_mmap_events
);
3525 if (event
->attr
.comm
)
3526 atomic_dec(&nr_comm_events
);
3527 if (event
->attr
.task
)
3528 atomic_dec(&nr_task_events
);
3529 if (event
->attr
.freq
)
3530 atomic_dec(&nr_freq_events
);
3531 if (event
->attr
.context_switch
) {
3533 atomic_dec(&nr_switch_events
);
3535 if (is_cgroup_event(event
))
3537 if (has_branch_stack(event
))
3541 static_key_slow_dec_deferred(&perf_sched_events
);
3543 unaccount_event_cpu(event
, event
->cpu
);
3547 * The following implement mutual exclusion of events on "exclusive" pmus
3548 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3549 * at a time, so we disallow creating events that might conflict, namely:
3551 * 1) cpu-wide events in the presence of per-task events,
3552 * 2) per-task events in the presence of cpu-wide events,
3553 * 3) two matching events on the same context.
3555 * The former two cases are handled in the allocation path (perf_event_alloc(),
3556 * _free_event()), the latter -- before the first perf_install_in_context().
3558 static int exclusive_event_init(struct perf_event
*event
)
3560 struct pmu
*pmu
= event
->pmu
;
3562 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3566 * Prevent co-existence of per-task and cpu-wide events on the
3567 * same exclusive pmu.
3569 * Negative pmu::exclusive_cnt means there are cpu-wide
3570 * events on this "exclusive" pmu, positive means there are
3573 * Since this is called in perf_event_alloc() path, event::ctx
3574 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3575 * to mean "per-task event", because unlike other attach states it
3576 * never gets cleared.
3578 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3579 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3582 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3589 static void exclusive_event_destroy(struct perf_event
*event
)
3591 struct pmu
*pmu
= event
->pmu
;
3593 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3596 /* see comment in exclusive_event_init() */
3597 if (event
->attach_state
& PERF_ATTACH_TASK
)
3598 atomic_dec(&pmu
->exclusive_cnt
);
3600 atomic_inc(&pmu
->exclusive_cnt
);
3603 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3605 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3606 (e1
->cpu
== e2
->cpu
||
3613 /* Called under the same ctx::mutex as perf_install_in_context() */
3614 static bool exclusive_event_installable(struct perf_event
*event
,
3615 struct perf_event_context
*ctx
)
3617 struct perf_event
*iter_event
;
3618 struct pmu
*pmu
= event
->pmu
;
3620 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3623 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3624 if (exclusive_event_match(iter_event
, event
))
3631 static void _free_event(struct perf_event
*event
)
3633 irq_work_sync(&event
->pending
);
3635 unaccount_event(event
);
3639 * Can happen when we close an event with re-directed output.
3641 * Since we have a 0 refcount, perf_mmap_close() will skip
3642 * over us; possibly making our ring_buffer_put() the last.
3644 mutex_lock(&event
->mmap_mutex
);
3645 ring_buffer_attach(event
, NULL
);
3646 mutex_unlock(&event
->mmap_mutex
);
3649 if (is_cgroup_event(event
))
3650 perf_detach_cgroup(event
);
3652 if (!event
->parent
) {
3653 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3654 put_callchain_buffers();
3657 perf_event_free_bpf_prog(event
);
3660 event
->destroy(event
);
3663 put_ctx(event
->ctx
);
3666 exclusive_event_destroy(event
);
3667 module_put(event
->pmu
->module
);
3670 call_rcu(&event
->rcu_head
, free_event_rcu
);
3674 * Used to free events which have a known refcount of 1, such as in error paths
3675 * where the event isn't exposed yet and inherited events.
3677 static void free_event(struct perf_event
*event
)
3679 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3680 "unexpected event refcount: %ld; ptr=%p\n",
3681 atomic_long_read(&event
->refcount
), event
)) {
3682 /* leak to avoid use-after-free */
3690 * Remove user event from the owner task.
3692 static void perf_remove_from_owner(struct perf_event
*event
)
3694 struct task_struct
*owner
;
3698 * Matches the smp_store_release() in perf_event_exit_task(). If we
3699 * observe !owner it means the list deletion is complete and we can
3700 * indeed free this event, otherwise we need to serialize on
3701 * owner->perf_event_mutex.
3703 owner
= lockless_dereference(event
->owner
);
3706 * Since delayed_put_task_struct() also drops the last
3707 * task reference we can safely take a new reference
3708 * while holding the rcu_read_lock().
3710 get_task_struct(owner
);
3716 * If we're here through perf_event_exit_task() we're already
3717 * holding ctx->mutex which would be an inversion wrt. the
3718 * normal lock order.
3720 * However we can safely take this lock because its the child
3723 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3726 * We have to re-check the event->owner field, if it is cleared
3727 * we raced with perf_event_exit_task(), acquiring the mutex
3728 * ensured they're done, and we can proceed with freeing the
3732 list_del_init(&event
->owner_entry
);
3733 smp_store_release(&event
->owner
, NULL
);
3735 mutex_unlock(&owner
->perf_event_mutex
);
3736 put_task_struct(owner
);
3740 static void put_event(struct perf_event
*event
)
3742 if (!atomic_long_dec_and_test(&event
->refcount
))
3749 * Kill an event dead; while event:refcount will preserve the event
3750 * object, it will not preserve its functionality. Once the last 'user'
3751 * gives up the object, we'll destroy the thing.
3753 int perf_event_release_kernel(struct perf_event
*event
)
3755 struct perf_event_context
*ctx
;
3756 struct perf_event
*child
, *tmp
;
3758 if (!is_kernel_event(event
))
3759 perf_remove_from_owner(event
);
3761 ctx
= perf_event_ctx_lock(event
);
3762 WARN_ON_ONCE(ctx
->parent_ctx
);
3763 perf_remove_from_context(event
, DETACH_GROUP
| DETACH_STATE
);
3764 perf_event_ctx_unlock(event
, ctx
);
3767 * At this point we must have event->state == PERF_EVENT_STATE_EXIT,
3768 * either from the above perf_remove_from_context() or through
3769 * perf_event_exit_event().
3771 * Therefore, anybody acquiring event->child_mutex after the below
3772 * loop _must_ also see this, most importantly inherit_event() which
3773 * will avoid placing more children on the list.
3775 * Thus this guarantees that we will in fact observe and kill _ALL_
3778 WARN_ON_ONCE(event
->state
!= PERF_EVENT_STATE_EXIT
);
3781 mutex_lock(&event
->child_mutex
);
3782 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3785 * Cannot change, child events are not migrated, see the
3786 * comment with perf_event_ctx_lock_nested().
3788 ctx
= lockless_dereference(child
->ctx
);
3790 * Since child_mutex nests inside ctx::mutex, we must jump
3791 * through hoops. We start by grabbing a reference on the ctx.
3793 * Since the event cannot get freed while we hold the
3794 * child_mutex, the context must also exist and have a !0
3800 * Now that we have a ctx ref, we can drop child_mutex, and
3801 * acquire ctx::mutex without fear of it going away. Then we
3802 * can re-acquire child_mutex.
3804 mutex_unlock(&event
->child_mutex
);
3805 mutex_lock(&ctx
->mutex
);
3806 mutex_lock(&event
->child_mutex
);
3809 * Now that we hold ctx::mutex and child_mutex, revalidate our
3810 * state, if child is still the first entry, it didn't get freed
3811 * and we can continue doing so.
3813 tmp
= list_first_entry_or_null(&event
->child_list
,
3814 struct perf_event
, child_list
);
3816 perf_remove_from_context(child
, DETACH_GROUP
);
3817 list_del(&child
->child_list
);
3820 * This matches the refcount bump in inherit_event();
3821 * this can't be the last reference.
3826 mutex_unlock(&event
->child_mutex
);
3827 mutex_unlock(&ctx
->mutex
);
3831 mutex_unlock(&event
->child_mutex
);
3833 /* Must be the last reference */
3837 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3840 * Called when the last reference to the file is gone.
3842 static int perf_release(struct inode
*inode
, struct file
*file
)
3844 perf_event_release_kernel(file
->private_data
);
3848 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3850 struct perf_event
*child
;
3856 mutex_lock(&event
->child_mutex
);
3858 (void)perf_event_read(event
, false);
3859 total
+= perf_event_count(event
);
3861 *enabled
+= event
->total_time_enabled
+
3862 atomic64_read(&event
->child_total_time_enabled
);
3863 *running
+= event
->total_time_running
+
3864 atomic64_read(&event
->child_total_time_running
);
3866 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3867 (void)perf_event_read(child
, false);
3868 total
+= perf_event_count(child
);
3869 *enabled
+= child
->total_time_enabled
;
3870 *running
+= child
->total_time_running
;
3872 mutex_unlock(&event
->child_mutex
);
3876 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3878 static int __perf_read_group_add(struct perf_event
*leader
,
3879 u64 read_format
, u64
*values
)
3881 struct perf_event
*sub
;
3882 int n
= 1; /* skip @nr */
3885 ret
= perf_event_read(leader
, true);
3890 * Since we co-schedule groups, {enabled,running} times of siblings
3891 * will be identical to those of the leader, so we only publish one
3894 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3895 values
[n
++] += leader
->total_time_enabled
+
3896 atomic64_read(&leader
->child_total_time_enabled
);
3899 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3900 values
[n
++] += leader
->total_time_running
+
3901 atomic64_read(&leader
->child_total_time_running
);
3905 * Write {count,id} tuples for every sibling.
3907 values
[n
++] += perf_event_count(leader
);
3908 if (read_format
& PERF_FORMAT_ID
)
3909 values
[n
++] = primary_event_id(leader
);
3911 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3912 values
[n
++] += perf_event_count(sub
);
3913 if (read_format
& PERF_FORMAT_ID
)
3914 values
[n
++] = primary_event_id(sub
);
3920 static int perf_read_group(struct perf_event
*event
,
3921 u64 read_format
, char __user
*buf
)
3923 struct perf_event
*leader
= event
->group_leader
, *child
;
3924 struct perf_event_context
*ctx
= leader
->ctx
;
3928 lockdep_assert_held(&ctx
->mutex
);
3930 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
3934 values
[0] = 1 + leader
->nr_siblings
;
3937 * By locking the child_mutex of the leader we effectively
3938 * lock the child list of all siblings.. XXX explain how.
3940 mutex_lock(&leader
->child_mutex
);
3942 ret
= __perf_read_group_add(leader
, read_format
, values
);
3946 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
3947 ret
= __perf_read_group_add(child
, read_format
, values
);
3952 mutex_unlock(&leader
->child_mutex
);
3954 ret
= event
->read_size
;
3955 if (copy_to_user(buf
, values
, event
->read_size
))
3960 mutex_unlock(&leader
->child_mutex
);
3966 static int perf_read_one(struct perf_event
*event
,
3967 u64 read_format
, char __user
*buf
)
3969 u64 enabled
, running
;
3973 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3974 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3975 values
[n
++] = enabled
;
3976 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3977 values
[n
++] = running
;
3978 if (read_format
& PERF_FORMAT_ID
)
3979 values
[n
++] = primary_event_id(event
);
3981 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3984 return n
* sizeof(u64
);
3987 static bool is_event_hup(struct perf_event
*event
)
3991 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
3994 mutex_lock(&event
->child_mutex
);
3995 no_children
= list_empty(&event
->child_list
);
3996 mutex_unlock(&event
->child_mutex
);
4001 * Read the performance event - simple non blocking version for now
4004 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4006 u64 read_format
= event
->attr
.read_format
;
4010 * Return end-of-file for a read on a event that is in
4011 * error state (i.e. because it was pinned but it couldn't be
4012 * scheduled on to the CPU at some point).
4014 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4017 if (count
< event
->read_size
)
4020 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4021 if (read_format
& PERF_FORMAT_GROUP
)
4022 ret
= perf_read_group(event
, read_format
, buf
);
4024 ret
= perf_read_one(event
, read_format
, buf
);
4030 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4032 struct perf_event
*event
= file
->private_data
;
4033 struct perf_event_context
*ctx
;
4036 ctx
= perf_event_ctx_lock(event
);
4037 ret
= __perf_read(event
, buf
, count
);
4038 perf_event_ctx_unlock(event
, ctx
);
4043 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4045 struct perf_event
*event
= file
->private_data
;
4046 struct ring_buffer
*rb
;
4047 unsigned int events
= POLLHUP
;
4049 poll_wait(file
, &event
->waitq
, wait
);
4051 if (is_event_hup(event
))
4055 * Pin the event->rb by taking event->mmap_mutex; otherwise
4056 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4058 mutex_lock(&event
->mmap_mutex
);
4061 events
= atomic_xchg(&rb
->poll
, 0);
4062 mutex_unlock(&event
->mmap_mutex
);
4066 static void _perf_event_reset(struct perf_event
*event
)
4068 (void)perf_event_read(event
, false);
4069 local64_set(&event
->count
, 0);
4070 perf_event_update_userpage(event
);
4074 * Holding the top-level event's child_mutex means that any
4075 * descendant process that has inherited this event will block
4076 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4077 * task existence requirements of perf_event_enable/disable.
4079 static void perf_event_for_each_child(struct perf_event
*event
,
4080 void (*func
)(struct perf_event
*))
4082 struct perf_event
*child
;
4084 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4086 mutex_lock(&event
->child_mutex
);
4088 list_for_each_entry(child
, &event
->child_list
, child_list
)
4090 mutex_unlock(&event
->child_mutex
);
4093 static void perf_event_for_each(struct perf_event
*event
,
4094 void (*func
)(struct perf_event
*))
4096 struct perf_event_context
*ctx
= event
->ctx
;
4097 struct perf_event
*sibling
;
4099 lockdep_assert_held(&ctx
->mutex
);
4101 event
= event
->group_leader
;
4103 perf_event_for_each_child(event
, func
);
4104 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4105 perf_event_for_each_child(sibling
, func
);
4108 static void __perf_event_period(struct perf_event
*event
,
4109 struct perf_cpu_context
*cpuctx
,
4110 struct perf_event_context
*ctx
,
4113 u64 value
= *((u64
*)info
);
4116 if (event
->attr
.freq
) {
4117 event
->attr
.sample_freq
= value
;
4119 event
->attr
.sample_period
= value
;
4120 event
->hw
.sample_period
= value
;
4123 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4125 perf_pmu_disable(ctx
->pmu
);
4126 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4129 local64_set(&event
->hw
.period_left
, 0);
4132 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4133 perf_pmu_enable(ctx
->pmu
);
4137 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4141 if (!is_sampling_event(event
))
4144 if (copy_from_user(&value
, arg
, sizeof(value
)))
4150 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4153 event_function_call(event
, __perf_event_period
, &value
);
4158 static const struct file_operations perf_fops
;
4160 static inline int perf_fget_light(int fd
, struct fd
*p
)
4162 struct fd f
= fdget(fd
);
4166 if (f
.file
->f_op
!= &perf_fops
) {
4174 static int perf_event_set_output(struct perf_event
*event
,
4175 struct perf_event
*output_event
);
4176 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4177 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4179 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4181 void (*func
)(struct perf_event
*);
4185 case PERF_EVENT_IOC_ENABLE
:
4186 func
= _perf_event_enable
;
4188 case PERF_EVENT_IOC_DISABLE
:
4189 func
= _perf_event_disable
;
4191 case PERF_EVENT_IOC_RESET
:
4192 func
= _perf_event_reset
;
4195 case PERF_EVENT_IOC_REFRESH
:
4196 return _perf_event_refresh(event
, arg
);
4198 case PERF_EVENT_IOC_PERIOD
:
4199 return perf_event_period(event
, (u64 __user
*)arg
);
4201 case PERF_EVENT_IOC_ID
:
4203 u64 id
= primary_event_id(event
);
4205 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4210 case PERF_EVENT_IOC_SET_OUTPUT
:
4214 struct perf_event
*output_event
;
4216 ret
= perf_fget_light(arg
, &output
);
4219 output_event
= output
.file
->private_data
;
4220 ret
= perf_event_set_output(event
, output_event
);
4223 ret
= perf_event_set_output(event
, NULL
);
4228 case PERF_EVENT_IOC_SET_FILTER
:
4229 return perf_event_set_filter(event
, (void __user
*)arg
);
4231 case PERF_EVENT_IOC_SET_BPF
:
4232 return perf_event_set_bpf_prog(event
, arg
);
4238 if (flags
& PERF_IOC_FLAG_GROUP
)
4239 perf_event_for_each(event
, func
);
4241 perf_event_for_each_child(event
, func
);
4246 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4248 struct perf_event
*event
= file
->private_data
;
4249 struct perf_event_context
*ctx
;
4252 ctx
= perf_event_ctx_lock(event
);
4253 ret
= _perf_ioctl(event
, cmd
, arg
);
4254 perf_event_ctx_unlock(event
, ctx
);
4259 #ifdef CONFIG_COMPAT
4260 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4263 switch (_IOC_NR(cmd
)) {
4264 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4265 case _IOC_NR(PERF_EVENT_IOC_ID
):
4266 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4267 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4268 cmd
&= ~IOCSIZE_MASK
;
4269 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4273 return perf_ioctl(file
, cmd
, arg
);
4276 # define perf_compat_ioctl NULL
4279 int perf_event_task_enable(void)
4281 struct perf_event_context
*ctx
;
4282 struct perf_event
*event
;
4284 mutex_lock(¤t
->perf_event_mutex
);
4285 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4286 ctx
= perf_event_ctx_lock(event
);
4287 perf_event_for_each_child(event
, _perf_event_enable
);
4288 perf_event_ctx_unlock(event
, ctx
);
4290 mutex_unlock(¤t
->perf_event_mutex
);
4295 int perf_event_task_disable(void)
4297 struct perf_event_context
*ctx
;
4298 struct perf_event
*event
;
4300 mutex_lock(¤t
->perf_event_mutex
);
4301 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4302 ctx
= perf_event_ctx_lock(event
);
4303 perf_event_for_each_child(event
, _perf_event_disable
);
4304 perf_event_ctx_unlock(event
, ctx
);
4306 mutex_unlock(¤t
->perf_event_mutex
);
4311 static int perf_event_index(struct perf_event
*event
)
4313 if (event
->hw
.state
& PERF_HES_STOPPED
)
4316 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4319 return event
->pmu
->event_idx(event
);
4322 static void calc_timer_values(struct perf_event
*event
,
4329 *now
= perf_clock();
4330 ctx_time
= event
->shadow_ctx_time
+ *now
;
4331 *enabled
= ctx_time
- event
->tstamp_enabled
;
4332 *running
= ctx_time
- event
->tstamp_running
;
4335 static void perf_event_init_userpage(struct perf_event
*event
)
4337 struct perf_event_mmap_page
*userpg
;
4338 struct ring_buffer
*rb
;
4341 rb
= rcu_dereference(event
->rb
);
4345 userpg
= rb
->user_page
;
4347 /* Allow new userspace to detect that bit 0 is deprecated */
4348 userpg
->cap_bit0_is_deprecated
= 1;
4349 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4350 userpg
->data_offset
= PAGE_SIZE
;
4351 userpg
->data_size
= perf_data_size(rb
);
4357 void __weak
arch_perf_update_userpage(
4358 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4363 * Callers need to ensure there can be no nesting of this function, otherwise
4364 * the seqlock logic goes bad. We can not serialize this because the arch
4365 * code calls this from NMI context.
4367 void perf_event_update_userpage(struct perf_event
*event
)
4369 struct perf_event_mmap_page
*userpg
;
4370 struct ring_buffer
*rb
;
4371 u64 enabled
, running
, now
;
4374 rb
= rcu_dereference(event
->rb
);
4379 * compute total_time_enabled, total_time_running
4380 * based on snapshot values taken when the event
4381 * was last scheduled in.
4383 * we cannot simply called update_context_time()
4384 * because of locking issue as we can be called in
4387 calc_timer_values(event
, &now
, &enabled
, &running
);
4389 userpg
= rb
->user_page
;
4391 * Disable preemption so as to not let the corresponding user-space
4392 * spin too long if we get preempted.
4397 userpg
->index
= perf_event_index(event
);
4398 userpg
->offset
= perf_event_count(event
);
4400 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4402 userpg
->time_enabled
= enabled
+
4403 atomic64_read(&event
->child_total_time_enabled
);
4405 userpg
->time_running
= running
+
4406 atomic64_read(&event
->child_total_time_running
);
4408 arch_perf_update_userpage(event
, userpg
, now
);
4417 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4419 struct perf_event
*event
= vma
->vm_file
->private_data
;
4420 struct ring_buffer
*rb
;
4421 int ret
= VM_FAULT_SIGBUS
;
4423 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4424 if (vmf
->pgoff
== 0)
4430 rb
= rcu_dereference(event
->rb
);
4434 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4437 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4441 get_page(vmf
->page
);
4442 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4443 vmf
->page
->index
= vmf
->pgoff
;
4452 static void ring_buffer_attach(struct perf_event
*event
,
4453 struct ring_buffer
*rb
)
4455 struct ring_buffer
*old_rb
= NULL
;
4456 unsigned long flags
;
4460 * Should be impossible, we set this when removing
4461 * event->rb_entry and wait/clear when adding event->rb_entry.
4463 WARN_ON_ONCE(event
->rcu_pending
);
4466 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4467 list_del_rcu(&event
->rb_entry
);
4468 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4470 event
->rcu_batches
= get_state_synchronize_rcu();
4471 event
->rcu_pending
= 1;
4475 if (event
->rcu_pending
) {
4476 cond_synchronize_rcu(event
->rcu_batches
);
4477 event
->rcu_pending
= 0;
4480 spin_lock_irqsave(&rb
->event_lock
, flags
);
4481 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4482 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4485 rcu_assign_pointer(event
->rb
, rb
);
4488 ring_buffer_put(old_rb
);
4490 * Since we detached before setting the new rb, so that we
4491 * could attach the new rb, we could have missed a wakeup.
4494 wake_up_all(&event
->waitq
);
4498 static void ring_buffer_wakeup(struct perf_event
*event
)
4500 struct ring_buffer
*rb
;
4503 rb
= rcu_dereference(event
->rb
);
4505 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4506 wake_up_all(&event
->waitq
);
4511 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4513 struct ring_buffer
*rb
;
4516 rb
= rcu_dereference(event
->rb
);
4518 if (!atomic_inc_not_zero(&rb
->refcount
))
4526 void ring_buffer_put(struct ring_buffer
*rb
)
4528 if (!atomic_dec_and_test(&rb
->refcount
))
4531 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4533 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4536 static void perf_mmap_open(struct vm_area_struct
*vma
)
4538 struct perf_event
*event
= vma
->vm_file
->private_data
;
4540 atomic_inc(&event
->mmap_count
);
4541 atomic_inc(&event
->rb
->mmap_count
);
4544 atomic_inc(&event
->rb
->aux_mmap_count
);
4546 if (event
->pmu
->event_mapped
)
4547 event
->pmu
->event_mapped(event
);
4551 * A buffer can be mmap()ed multiple times; either directly through the same
4552 * event, or through other events by use of perf_event_set_output().
4554 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4555 * the buffer here, where we still have a VM context. This means we need
4556 * to detach all events redirecting to us.
4558 static void perf_mmap_close(struct vm_area_struct
*vma
)
4560 struct perf_event
*event
= vma
->vm_file
->private_data
;
4562 struct ring_buffer
*rb
= ring_buffer_get(event
);
4563 struct user_struct
*mmap_user
= rb
->mmap_user
;
4564 int mmap_locked
= rb
->mmap_locked
;
4565 unsigned long size
= perf_data_size(rb
);
4567 if (event
->pmu
->event_unmapped
)
4568 event
->pmu
->event_unmapped(event
);
4571 * rb->aux_mmap_count will always drop before rb->mmap_count and
4572 * event->mmap_count, so it is ok to use event->mmap_mutex to
4573 * serialize with perf_mmap here.
4575 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4576 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4577 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4578 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4581 mutex_unlock(&event
->mmap_mutex
);
4584 atomic_dec(&rb
->mmap_count
);
4586 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4589 ring_buffer_attach(event
, NULL
);
4590 mutex_unlock(&event
->mmap_mutex
);
4592 /* If there's still other mmap()s of this buffer, we're done. */
4593 if (atomic_read(&rb
->mmap_count
))
4597 * No other mmap()s, detach from all other events that might redirect
4598 * into the now unreachable buffer. Somewhat complicated by the
4599 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4603 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4604 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4606 * This event is en-route to free_event() which will
4607 * detach it and remove it from the list.
4613 mutex_lock(&event
->mmap_mutex
);
4615 * Check we didn't race with perf_event_set_output() which can
4616 * swizzle the rb from under us while we were waiting to
4617 * acquire mmap_mutex.
4619 * If we find a different rb; ignore this event, a next
4620 * iteration will no longer find it on the list. We have to
4621 * still restart the iteration to make sure we're not now
4622 * iterating the wrong list.
4624 if (event
->rb
== rb
)
4625 ring_buffer_attach(event
, NULL
);
4627 mutex_unlock(&event
->mmap_mutex
);
4631 * Restart the iteration; either we're on the wrong list or
4632 * destroyed its integrity by doing a deletion.
4639 * It could be there's still a few 0-ref events on the list; they'll
4640 * get cleaned up by free_event() -- they'll also still have their
4641 * ref on the rb and will free it whenever they are done with it.
4643 * Aside from that, this buffer is 'fully' detached and unmapped,
4644 * undo the VM accounting.
4647 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4648 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4649 free_uid(mmap_user
);
4652 ring_buffer_put(rb
); /* could be last */
4655 static const struct vm_operations_struct perf_mmap_vmops
= {
4656 .open
= perf_mmap_open
,
4657 .close
= perf_mmap_close
, /* non mergable */
4658 .fault
= perf_mmap_fault
,
4659 .page_mkwrite
= perf_mmap_fault
,
4662 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4664 struct perf_event
*event
= file
->private_data
;
4665 unsigned long user_locked
, user_lock_limit
;
4666 struct user_struct
*user
= current_user();
4667 unsigned long locked
, lock_limit
;
4668 struct ring_buffer
*rb
= NULL
;
4669 unsigned long vma_size
;
4670 unsigned long nr_pages
;
4671 long user_extra
= 0, extra
= 0;
4672 int ret
= 0, flags
= 0;
4675 * Don't allow mmap() of inherited per-task counters. This would
4676 * create a performance issue due to all children writing to the
4679 if (event
->cpu
== -1 && event
->attr
.inherit
)
4682 if (!(vma
->vm_flags
& VM_SHARED
))
4685 vma_size
= vma
->vm_end
- vma
->vm_start
;
4687 if (vma
->vm_pgoff
== 0) {
4688 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4691 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4692 * mapped, all subsequent mappings should have the same size
4693 * and offset. Must be above the normal perf buffer.
4695 u64 aux_offset
, aux_size
;
4700 nr_pages
= vma_size
/ PAGE_SIZE
;
4702 mutex_lock(&event
->mmap_mutex
);
4709 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4710 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4712 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4715 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4718 /* already mapped with a different offset */
4719 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4722 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4725 /* already mapped with a different size */
4726 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4729 if (!is_power_of_2(nr_pages
))
4732 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4735 if (rb_has_aux(rb
)) {
4736 atomic_inc(&rb
->aux_mmap_count
);
4741 atomic_set(&rb
->aux_mmap_count
, 1);
4742 user_extra
= nr_pages
;
4748 * If we have rb pages ensure they're a power-of-two number, so we
4749 * can do bitmasks instead of modulo.
4751 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4754 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4757 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4759 mutex_lock(&event
->mmap_mutex
);
4761 if (event
->rb
->nr_pages
!= nr_pages
) {
4766 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4768 * Raced against perf_mmap_close() through
4769 * perf_event_set_output(). Try again, hope for better
4772 mutex_unlock(&event
->mmap_mutex
);
4779 user_extra
= nr_pages
+ 1;
4782 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4785 * Increase the limit linearly with more CPUs:
4787 user_lock_limit
*= num_online_cpus();
4789 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4791 if (user_locked
> user_lock_limit
)
4792 extra
= user_locked
- user_lock_limit
;
4794 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4795 lock_limit
>>= PAGE_SHIFT
;
4796 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4798 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4799 !capable(CAP_IPC_LOCK
)) {
4804 WARN_ON(!rb
&& event
->rb
);
4806 if (vma
->vm_flags
& VM_WRITE
)
4807 flags
|= RING_BUFFER_WRITABLE
;
4810 rb
= rb_alloc(nr_pages
,
4811 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4819 atomic_set(&rb
->mmap_count
, 1);
4820 rb
->mmap_user
= get_current_user();
4821 rb
->mmap_locked
= extra
;
4823 ring_buffer_attach(event
, rb
);
4825 perf_event_init_userpage(event
);
4826 perf_event_update_userpage(event
);
4828 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4829 event
->attr
.aux_watermark
, flags
);
4831 rb
->aux_mmap_locked
= extra
;
4836 atomic_long_add(user_extra
, &user
->locked_vm
);
4837 vma
->vm_mm
->pinned_vm
+= extra
;
4839 atomic_inc(&event
->mmap_count
);
4841 atomic_dec(&rb
->mmap_count
);
4844 mutex_unlock(&event
->mmap_mutex
);
4847 * Since pinned accounting is per vm we cannot allow fork() to copy our
4850 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4851 vma
->vm_ops
= &perf_mmap_vmops
;
4853 if (event
->pmu
->event_mapped
)
4854 event
->pmu
->event_mapped(event
);
4859 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4861 struct inode
*inode
= file_inode(filp
);
4862 struct perf_event
*event
= filp
->private_data
;
4866 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4867 inode_unlock(inode
);
4875 static const struct file_operations perf_fops
= {
4876 .llseek
= no_llseek
,
4877 .release
= perf_release
,
4880 .unlocked_ioctl
= perf_ioctl
,
4881 .compat_ioctl
= perf_compat_ioctl
,
4883 .fasync
= perf_fasync
,
4889 * If there's data, ensure we set the poll() state and publish everything
4890 * to user-space before waking everybody up.
4893 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
4895 /* only the parent has fasync state */
4897 event
= event
->parent
;
4898 return &event
->fasync
;
4901 void perf_event_wakeup(struct perf_event
*event
)
4903 ring_buffer_wakeup(event
);
4905 if (event
->pending_kill
) {
4906 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
4907 event
->pending_kill
= 0;
4911 static void perf_pending_event(struct irq_work
*entry
)
4913 struct perf_event
*event
= container_of(entry
,
4914 struct perf_event
, pending
);
4917 rctx
= perf_swevent_get_recursion_context();
4919 * If we 'fail' here, that's OK, it means recursion is already disabled
4920 * and we won't recurse 'further'.
4923 if (event
->pending_disable
) {
4924 event
->pending_disable
= 0;
4925 perf_event_disable_local(event
);
4928 if (event
->pending_wakeup
) {
4929 event
->pending_wakeup
= 0;
4930 perf_event_wakeup(event
);
4934 perf_swevent_put_recursion_context(rctx
);
4938 * We assume there is only KVM supporting the callbacks.
4939 * Later on, we might change it to a list if there is
4940 * another virtualization implementation supporting the callbacks.
4942 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4944 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4946 perf_guest_cbs
= cbs
;
4949 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4951 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4953 perf_guest_cbs
= NULL
;
4956 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4959 perf_output_sample_regs(struct perf_output_handle
*handle
,
4960 struct pt_regs
*regs
, u64 mask
)
4964 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4965 sizeof(mask
) * BITS_PER_BYTE
) {
4968 val
= perf_reg_value(regs
, bit
);
4969 perf_output_put(handle
, val
);
4973 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
4974 struct pt_regs
*regs
,
4975 struct pt_regs
*regs_user_copy
)
4977 if (user_mode(regs
)) {
4978 regs_user
->abi
= perf_reg_abi(current
);
4979 regs_user
->regs
= regs
;
4980 } else if (current
->mm
) {
4981 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
4983 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
4984 regs_user
->regs
= NULL
;
4988 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
4989 struct pt_regs
*regs
)
4991 regs_intr
->regs
= regs
;
4992 regs_intr
->abi
= perf_reg_abi(current
);
4997 * Get remaining task size from user stack pointer.
4999 * It'd be better to take stack vma map and limit this more
5000 * precisly, but there's no way to get it safely under interrupt,
5001 * so using TASK_SIZE as limit.
5003 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5005 unsigned long addr
= perf_user_stack_pointer(regs
);
5007 if (!addr
|| addr
>= TASK_SIZE
)
5010 return TASK_SIZE
- addr
;
5014 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5015 struct pt_regs
*regs
)
5019 /* No regs, no stack pointer, no dump. */
5024 * Check if we fit in with the requested stack size into the:
5026 * If we don't, we limit the size to the TASK_SIZE.
5028 * - remaining sample size
5029 * If we don't, we customize the stack size to
5030 * fit in to the remaining sample size.
5033 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5034 stack_size
= min(stack_size
, (u16
) task_size
);
5036 /* Current header size plus static size and dynamic size. */
5037 header_size
+= 2 * sizeof(u64
);
5039 /* Do we fit in with the current stack dump size? */
5040 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5042 * If we overflow the maximum size for the sample,
5043 * we customize the stack dump size to fit in.
5045 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5046 stack_size
= round_up(stack_size
, sizeof(u64
));
5053 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5054 struct pt_regs
*regs
)
5056 /* Case of a kernel thread, nothing to dump */
5059 perf_output_put(handle
, size
);
5068 * - the size requested by user or the best one we can fit
5069 * in to the sample max size
5071 * - user stack dump data
5073 * - the actual dumped size
5077 perf_output_put(handle
, dump_size
);
5080 sp
= perf_user_stack_pointer(regs
);
5081 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5082 dyn_size
= dump_size
- rem
;
5084 perf_output_skip(handle
, rem
);
5087 perf_output_put(handle
, dyn_size
);
5091 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5092 struct perf_sample_data
*data
,
5093 struct perf_event
*event
)
5095 u64 sample_type
= event
->attr
.sample_type
;
5097 data
->type
= sample_type
;
5098 header
->size
+= event
->id_header_size
;
5100 if (sample_type
& PERF_SAMPLE_TID
) {
5101 /* namespace issues */
5102 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5103 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5106 if (sample_type
& PERF_SAMPLE_TIME
)
5107 data
->time
= perf_event_clock(event
);
5109 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5110 data
->id
= primary_event_id(event
);
5112 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5113 data
->stream_id
= event
->id
;
5115 if (sample_type
& PERF_SAMPLE_CPU
) {
5116 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5117 data
->cpu_entry
.reserved
= 0;
5121 void perf_event_header__init_id(struct perf_event_header
*header
,
5122 struct perf_sample_data
*data
,
5123 struct perf_event
*event
)
5125 if (event
->attr
.sample_id_all
)
5126 __perf_event_header__init_id(header
, data
, event
);
5129 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5130 struct perf_sample_data
*data
)
5132 u64 sample_type
= data
->type
;
5134 if (sample_type
& PERF_SAMPLE_TID
)
5135 perf_output_put(handle
, data
->tid_entry
);
5137 if (sample_type
& PERF_SAMPLE_TIME
)
5138 perf_output_put(handle
, data
->time
);
5140 if (sample_type
& PERF_SAMPLE_ID
)
5141 perf_output_put(handle
, data
->id
);
5143 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5144 perf_output_put(handle
, data
->stream_id
);
5146 if (sample_type
& PERF_SAMPLE_CPU
)
5147 perf_output_put(handle
, data
->cpu_entry
);
5149 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5150 perf_output_put(handle
, data
->id
);
5153 void perf_event__output_id_sample(struct perf_event
*event
,
5154 struct perf_output_handle
*handle
,
5155 struct perf_sample_data
*sample
)
5157 if (event
->attr
.sample_id_all
)
5158 __perf_event__output_id_sample(handle
, sample
);
5161 static void perf_output_read_one(struct perf_output_handle
*handle
,
5162 struct perf_event
*event
,
5163 u64 enabled
, u64 running
)
5165 u64 read_format
= event
->attr
.read_format
;
5169 values
[n
++] = perf_event_count(event
);
5170 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5171 values
[n
++] = enabled
+
5172 atomic64_read(&event
->child_total_time_enabled
);
5174 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5175 values
[n
++] = running
+
5176 atomic64_read(&event
->child_total_time_running
);
5178 if (read_format
& PERF_FORMAT_ID
)
5179 values
[n
++] = primary_event_id(event
);
5181 __output_copy(handle
, values
, n
* sizeof(u64
));
5185 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5187 static void perf_output_read_group(struct perf_output_handle
*handle
,
5188 struct perf_event
*event
,
5189 u64 enabled
, u64 running
)
5191 struct perf_event
*leader
= event
->group_leader
, *sub
;
5192 u64 read_format
= event
->attr
.read_format
;
5196 values
[n
++] = 1 + leader
->nr_siblings
;
5198 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5199 values
[n
++] = enabled
;
5201 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5202 values
[n
++] = running
;
5204 if (leader
!= event
)
5205 leader
->pmu
->read(leader
);
5207 values
[n
++] = perf_event_count(leader
);
5208 if (read_format
& PERF_FORMAT_ID
)
5209 values
[n
++] = primary_event_id(leader
);
5211 __output_copy(handle
, values
, n
* sizeof(u64
));
5213 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5216 if ((sub
!= event
) &&
5217 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5218 sub
->pmu
->read(sub
);
5220 values
[n
++] = perf_event_count(sub
);
5221 if (read_format
& PERF_FORMAT_ID
)
5222 values
[n
++] = primary_event_id(sub
);
5224 __output_copy(handle
, values
, n
* sizeof(u64
));
5228 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5229 PERF_FORMAT_TOTAL_TIME_RUNNING)
5231 static void perf_output_read(struct perf_output_handle
*handle
,
5232 struct perf_event
*event
)
5234 u64 enabled
= 0, running
= 0, now
;
5235 u64 read_format
= event
->attr
.read_format
;
5238 * compute total_time_enabled, total_time_running
5239 * based on snapshot values taken when the event
5240 * was last scheduled in.
5242 * we cannot simply called update_context_time()
5243 * because of locking issue as we are called in
5246 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5247 calc_timer_values(event
, &now
, &enabled
, &running
);
5249 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5250 perf_output_read_group(handle
, event
, enabled
, running
);
5252 perf_output_read_one(handle
, event
, enabled
, running
);
5255 void perf_output_sample(struct perf_output_handle
*handle
,
5256 struct perf_event_header
*header
,
5257 struct perf_sample_data
*data
,
5258 struct perf_event
*event
)
5260 u64 sample_type
= data
->type
;
5262 perf_output_put(handle
, *header
);
5264 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5265 perf_output_put(handle
, data
->id
);
5267 if (sample_type
& PERF_SAMPLE_IP
)
5268 perf_output_put(handle
, data
->ip
);
5270 if (sample_type
& PERF_SAMPLE_TID
)
5271 perf_output_put(handle
, data
->tid_entry
);
5273 if (sample_type
& PERF_SAMPLE_TIME
)
5274 perf_output_put(handle
, data
->time
);
5276 if (sample_type
& PERF_SAMPLE_ADDR
)
5277 perf_output_put(handle
, data
->addr
);
5279 if (sample_type
& PERF_SAMPLE_ID
)
5280 perf_output_put(handle
, data
->id
);
5282 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5283 perf_output_put(handle
, data
->stream_id
);
5285 if (sample_type
& PERF_SAMPLE_CPU
)
5286 perf_output_put(handle
, data
->cpu_entry
);
5288 if (sample_type
& PERF_SAMPLE_PERIOD
)
5289 perf_output_put(handle
, data
->period
);
5291 if (sample_type
& PERF_SAMPLE_READ
)
5292 perf_output_read(handle
, event
);
5294 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5295 if (data
->callchain
) {
5298 if (data
->callchain
)
5299 size
+= data
->callchain
->nr
;
5301 size
*= sizeof(u64
);
5303 __output_copy(handle
, data
->callchain
, size
);
5306 perf_output_put(handle
, nr
);
5310 if (sample_type
& PERF_SAMPLE_RAW
) {
5312 u32 raw_size
= data
->raw
->size
;
5313 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5314 sizeof(u64
)) - sizeof(u32
);
5317 perf_output_put(handle
, real_size
);
5318 __output_copy(handle
, data
->raw
->data
, raw_size
);
5319 if (real_size
- raw_size
)
5320 __output_copy(handle
, &zero
, real_size
- raw_size
);
5326 .size
= sizeof(u32
),
5329 perf_output_put(handle
, raw
);
5333 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5334 if (data
->br_stack
) {
5337 size
= data
->br_stack
->nr
5338 * sizeof(struct perf_branch_entry
);
5340 perf_output_put(handle
, data
->br_stack
->nr
);
5341 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5344 * we always store at least the value of nr
5347 perf_output_put(handle
, nr
);
5351 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5352 u64 abi
= data
->regs_user
.abi
;
5355 * If there are no regs to dump, notice it through
5356 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5358 perf_output_put(handle
, abi
);
5361 u64 mask
= event
->attr
.sample_regs_user
;
5362 perf_output_sample_regs(handle
,
5363 data
->regs_user
.regs
,
5368 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5369 perf_output_sample_ustack(handle
,
5370 data
->stack_user_size
,
5371 data
->regs_user
.regs
);
5374 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5375 perf_output_put(handle
, data
->weight
);
5377 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5378 perf_output_put(handle
, data
->data_src
.val
);
5380 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5381 perf_output_put(handle
, data
->txn
);
5383 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5384 u64 abi
= data
->regs_intr
.abi
;
5386 * If there are no regs to dump, notice it through
5387 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5389 perf_output_put(handle
, abi
);
5392 u64 mask
= event
->attr
.sample_regs_intr
;
5394 perf_output_sample_regs(handle
,
5395 data
->regs_intr
.regs
,
5400 if (!event
->attr
.watermark
) {
5401 int wakeup_events
= event
->attr
.wakeup_events
;
5403 if (wakeup_events
) {
5404 struct ring_buffer
*rb
= handle
->rb
;
5405 int events
= local_inc_return(&rb
->events
);
5407 if (events
>= wakeup_events
) {
5408 local_sub(wakeup_events
, &rb
->events
);
5409 local_inc(&rb
->wakeup
);
5415 void perf_prepare_sample(struct perf_event_header
*header
,
5416 struct perf_sample_data
*data
,
5417 struct perf_event
*event
,
5418 struct pt_regs
*regs
)
5420 u64 sample_type
= event
->attr
.sample_type
;
5422 header
->type
= PERF_RECORD_SAMPLE
;
5423 header
->size
= sizeof(*header
) + event
->header_size
;
5426 header
->misc
|= perf_misc_flags(regs
);
5428 __perf_event_header__init_id(header
, data
, event
);
5430 if (sample_type
& PERF_SAMPLE_IP
)
5431 data
->ip
= perf_instruction_pointer(regs
);
5433 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5436 data
->callchain
= perf_callchain(event
, regs
);
5438 if (data
->callchain
)
5439 size
+= data
->callchain
->nr
;
5441 header
->size
+= size
* sizeof(u64
);
5444 if (sample_type
& PERF_SAMPLE_RAW
) {
5445 int size
= sizeof(u32
);
5448 size
+= data
->raw
->size
;
5450 size
+= sizeof(u32
);
5452 header
->size
+= round_up(size
, sizeof(u64
));
5455 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5456 int size
= sizeof(u64
); /* nr */
5457 if (data
->br_stack
) {
5458 size
+= data
->br_stack
->nr
5459 * sizeof(struct perf_branch_entry
);
5461 header
->size
+= size
;
5464 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5465 perf_sample_regs_user(&data
->regs_user
, regs
,
5466 &data
->regs_user_copy
);
5468 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5469 /* regs dump ABI info */
5470 int size
= sizeof(u64
);
5472 if (data
->regs_user
.regs
) {
5473 u64 mask
= event
->attr
.sample_regs_user
;
5474 size
+= hweight64(mask
) * sizeof(u64
);
5477 header
->size
+= size
;
5480 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5482 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5483 * processed as the last one or have additional check added
5484 * in case new sample type is added, because we could eat
5485 * up the rest of the sample size.
5487 u16 stack_size
= event
->attr
.sample_stack_user
;
5488 u16 size
= sizeof(u64
);
5490 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5491 data
->regs_user
.regs
);
5494 * If there is something to dump, add space for the dump
5495 * itself and for the field that tells the dynamic size,
5496 * which is how many have been actually dumped.
5499 size
+= sizeof(u64
) + stack_size
;
5501 data
->stack_user_size
= stack_size
;
5502 header
->size
+= size
;
5505 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5506 /* regs dump ABI info */
5507 int size
= sizeof(u64
);
5509 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5511 if (data
->regs_intr
.regs
) {
5512 u64 mask
= event
->attr
.sample_regs_intr
;
5514 size
+= hweight64(mask
) * sizeof(u64
);
5517 header
->size
+= size
;
5521 void perf_event_output(struct perf_event
*event
,
5522 struct perf_sample_data
*data
,
5523 struct pt_regs
*regs
)
5525 struct perf_output_handle handle
;
5526 struct perf_event_header header
;
5528 /* protect the callchain buffers */
5531 perf_prepare_sample(&header
, data
, event
, regs
);
5533 if (perf_output_begin(&handle
, event
, header
.size
))
5536 perf_output_sample(&handle
, &header
, data
, event
);
5538 perf_output_end(&handle
);
5548 struct perf_read_event
{
5549 struct perf_event_header header
;
5556 perf_event_read_event(struct perf_event
*event
,
5557 struct task_struct
*task
)
5559 struct perf_output_handle handle
;
5560 struct perf_sample_data sample
;
5561 struct perf_read_event read_event
= {
5563 .type
= PERF_RECORD_READ
,
5565 .size
= sizeof(read_event
) + event
->read_size
,
5567 .pid
= perf_event_pid(event
, task
),
5568 .tid
= perf_event_tid(event
, task
),
5572 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5573 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5577 perf_output_put(&handle
, read_event
);
5578 perf_output_read(&handle
, event
);
5579 perf_event__output_id_sample(event
, &handle
, &sample
);
5581 perf_output_end(&handle
);
5584 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5587 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5588 perf_event_aux_output_cb output
,
5591 struct perf_event
*event
;
5593 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5594 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5596 if (!event_filter_match(event
))
5598 output(event
, data
);
5603 perf_event_aux_task_ctx(perf_event_aux_output_cb output
, void *data
,
5604 struct perf_event_context
*task_ctx
)
5608 perf_event_aux_ctx(task_ctx
, output
, data
);
5614 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5615 struct perf_event_context
*task_ctx
)
5617 struct perf_cpu_context
*cpuctx
;
5618 struct perf_event_context
*ctx
;
5623 * If we have task_ctx != NULL we only notify
5624 * the task context itself. The task_ctx is set
5625 * only for EXIT events before releasing task
5629 perf_event_aux_task_ctx(output
, data
, task_ctx
);
5634 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5635 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5636 if (cpuctx
->unique_pmu
!= pmu
)
5638 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5639 ctxn
= pmu
->task_ctx_nr
;
5642 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5644 perf_event_aux_ctx(ctx
, output
, data
);
5646 put_cpu_ptr(pmu
->pmu_cpu_context
);
5652 * task tracking -- fork/exit
5654 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5657 struct perf_task_event
{
5658 struct task_struct
*task
;
5659 struct perf_event_context
*task_ctx
;
5662 struct perf_event_header header
;
5672 static int perf_event_task_match(struct perf_event
*event
)
5674 return event
->attr
.comm
|| event
->attr
.mmap
||
5675 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5679 static void perf_event_task_output(struct perf_event
*event
,
5682 struct perf_task_event
*task_event
= data
;
5683 struct perf_output_handle handle
;
5684 struct perf_sample_data sample
;
5685 struct task_struct
*task
= task_event
->task
;
5686 int ret
, size
= task_event
->event_id
.header
.size
;
5688 if (!perf_event_task_match(event
))
5691 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5693 ret
= perf_output_begin(&handle
, event
,
5694 task_event
->event_id
.header
.size
);
5698 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5699 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5701 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5702 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5704 task_event
->event_id
.time
= perf_event_clock(event
);
5706 perf_output_put(&handle
, task_event
->event_id
);
5708 perf_event__output_id_sample(event
, &handle
, &sample
);
5710 perf_output_end(&handle
);
5712 task_event
->event_id
.header
.size
= size
;
5715 static void perf_event_task(struct task_struct
*task
,
5716 struct perf_event_context
*task_ctx
,
5719 struct perf_task_event task_event
;
5721 if (!atomic_read(&nr_comm_events
) &&
5722 !atomic_read(&nr_mmap_events
) &&
5723 !atomic_read(&nr_task_events
))
5726 task_event
= (struct perf_task_event
){
5728 .task_ctx
= task_ctx
,
5731 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5733 .size
= sizeof(task_event
.event_id
),
5743 perf_event_aux(perf_event_task_output
,
5748 void perf_event_fork(struct task_struct
*task
)
5750 perf_event_task(task
, NULL
, 1);
5757 struct perf_comm_event
{
5758 struct task_struct
*task
;
5763 struct perf_event_header header
;
5770 static int perf_event_comm_match(struct perf_event
*event
)
5772 return event
->attr
.comm
;
5775 static void perf_event_comm_output(struct perf_event
*event
,
5778 struct perf_comm_event
*comm_event
= data
;
5779 struct perf_output_handle handle
;
5780 struct perf_sample_data sample
;
5781 int size
= comm_event
->event_id
.header
.size
;
5784 if (!perf_event_comm_match(event
))
5787 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5788 ret
= perf_output_begin(&handle
, event
,
5789 comm_event
->event_id
.header
.size
);
5794 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5795 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5797 perf_output_put(&handle
, comm_event
->event_id
);
5798 __output_copy(&handle
, comm_event
->comm
,
5799 comm_event
->comm_size
);
5801 perf_event__output_id_sample(event
, &handle
, &sample
);
5803 perf_output_end(&handle
);
5805 comm_event
->event_id
.header
.size
= size
;
5808 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5810 char comm
[TASK_COMM_LEN
];
5813 memset(comm
, 0, sizeof(comm
));
5814 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5815 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5817 comm_event
->comm
= comm
;
5818 comm_event
->comm_size
= size
;
5820 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5822 perf_event_aux(perf_event_comm_output
,
5827 void perf_event_comm(struct task_struct
*task
, bool exec
)
5829 struct perf_comm_event comm_event
;
5831 if (!atomic_read(&nr_comm_events
))
5834 comm_event
= (struct perf_comm_event
){
5840 .type
= PERF_RECORD_COMM
,
5841 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5849 perf_event_comm_event(&comm_event
);
5856 struct perf_mmap_event
{
5857 struct vm_area_struct
*vma
;
5859 const char *file_name
;
5867 struct perf_event_header header
;
5877 static int perf_event_mmap_match(struct perf_event
*event
,
5880 struct perf_mmap_event
*mmap_event
= data
;
5881 struct vm_area_struct
*vma
= mmap_event
->vma
;
5882 int executable
= vma
->vm_flags
& VM_EXEC
;
5884 return (!executable
&& event
->attr
.mmap_data
) ||
5885 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5888 static void perf_event_mmap_output(struct perf_event
*event
,
5891 struct perf_mmap_event
*mmap_event
= data
;
5892 struct perf_output_handle handle
;
5893 struct perf_sample_data sample
;
5894 int size
= mmap_event
->event_id
.header
.size
;
5897 if (!perf_event_mmap_match(event
, data
))
5900 if (event
->attr
.mmap2
) {
5901 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5902 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5903 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5904 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5905 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5906 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5907 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5910 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5911 ret
= perf_output_begin(&handle
, event
,
5912 mmap_event
->event_id
.header
.size
);
5916 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5917 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5919 perf_output_put(&handle
, mmap_event
->event_id
);
5921 if (event
->attr
.mmap2
) {
5922 perf_output_put(&handle
, mmap_event
->maj
);
5923 perf_output_put(&handle
, mmap_event
->min
);
5924 perf_output_put(&handle
, mmap_event
->ino
);
5925 perf_output_put(&handle
, mmap_event
->ino_generation
);
5926 perf_output_put(&handle
, mmap_event
->prot
);
5927 perf_output_put(&handle
, mmap_event
->flags
);
5930 __output_copy(&handle
, mmap_event
->file_name
,
5931 mmap_event
->file_size
);
5933 perf_event__output_id_sample(event
, &handle
, &sample
);
5935 perf_output_end(&handle
);
5937 mmap_event
->event_id
.header
.size
= size
;
5940 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5942 struct vm_area_struct
*vma
= mmap_event
->vma
;
5943 struct file
*file
= vma
->vm_file
;
5944 int maj
= 0, min
= 0;
5945 u64 ino
= 0, gen
= 0;
5946 u32 prot
= 0, flags
= 0;
5953 struct inode
*inode
;
5956 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5962 * d_path() works from the end of the rb backwards, so we
5963 * need to add enough zero bytes after the string to handle
5964 * the 64bit alignment we do later.
5966 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
5971 inode
= file_inode(vma
->vm_file
);
5972 dev
= inode
->i_sb
->s_dev
;
5974 gen
= inode
->i_generation
;
5978 if (vma
->vm_flags
& VM_READ
)
5980 if (vma
->vm_flags
& VM_WRITE
)
5982 if (vma
->vm_flags
& VM_EXEC
)
5985 if (vma
->vm_flags
& VM_MAYSHARE
)
5988 flags
= MAP_PRIVATE
;
5990 if (vma
->vm_flags
& VM_DENYWRITE
)
5991 flags
|= MAP_DENYWRITE
;
5992 if (vma
->vm_flags
& VM_MAYEXEC
)
5993 flags
|= MAP_EXECUTABLE
;
5994 if (vma
->vm_flags
& VM_LOCKED
)
5995 flags
|= MAP_LOCKED
;
5996 if (vma
->vm_flags
& VM_HUGETLB
)
5997 flags
|= MAP_HUGETLB
;
6001 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6002 name
= (char *) vma
->vm_ops
->name(vma
);
6007 name
= (char *)arch_vma_name(vma
);
6011 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6012 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6016 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6017 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6027 strlcpy(tmp
, name
, sizeof(tmp
));
6031 * Since our buffer works in 8 byte units we need to align our string
6032 * size to a multiple of 8. However, we must guarantee the tail end is
6033 * zero'd out to avoid leaking random bits to userspace.
6035 size
= strlen(name
)+1;
6036 while (!IS_ALIGNED(size
, sizeof(u64
)))
6037 name
[size
++] = '\0';
6039 mmap_event
->file_name
= name
;
6040 mmap_event
->file_size
= size
;
6041 mmap_event
->maj
= maj
;
6042 mmap_event
->min
= min
;
6043 mmap_event
->ino
= ino
;
6044 mmap_event
->ino_generation
= gen
;
6045 mmap_event
->prot
= prot
;
6046 mmap_event
->flags
= flags
;
6048 if (!(vma
->vm_flags
& VM_EXEC
))
6049 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6051 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6053 perf_event_aux(perf_event_mmap_output
,
6060 void perf_event_mmap(struct vm_area_struct
*vma
)
6062 struct perf_mmap_event mmap_event
;
6064 if (!atomic_read(&nr_mmap_events
))
6067 mmap_event
= (struct perf_mmap_event
){
6073 .type
= PERF_RECORD_MMAP
,
6074 .misc
= PERF_RECORD_MISC_USER
,
6079 .start
= vma
->vm_start
,
6080 .len
= vma
->vm_end
- vma
->vm_start
,
6081 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6083 /* .maj (attr_mmap2 only) */
6084 /* .min (attr_mmap2 only) */
6085 /* .ino (attr_mmap2 only) */
6086 /* .ino_generation (attr_mmap2 only) */
6087 /* .prot (attr_mmap2 only) */
6088 /* .flags (attr_mmap2 only) */
6091 perf_event_mmap_event(&mmap_event
);
6094 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6095 unsigned long size
, u64 flags
)
6097 struct perf_output_handle handle
;
6098 struct perf_sample_data sample
;
6099 struct perf_aux_event
{
6100 struct perf_event_header header
;
6106 .type
= PERF_RECORD_AUX
,
6108 .size
= sizeof(rec
),
6116 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6117 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6122 perf_output_put(&handle
, rec
);
6123 perf_event__output_id_sample(event
, &handle
, &sample
);
6125 perf_output_end(&handle
);
6129 * Lost/dropped samples logging
6131 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6133 struct perf_output_handle handle
;
6134 struct perf_sample_data sample
;
6138 struct perf_event_header header
;
6140 } lost_samples_event
= {
6142 .type
= PERF_RECORD_LOST_SAMPLES
,
6144 .size
= sizeof(lost_samples_event
),
6149 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6151 ret
= perf_output_begin(&handle
, event
,
6152 lost_samples_event
.header
.size
);
6156 perf_output_put(&handle
, lost_samples_event
);
6157 perf_event__output_id_sample(event
, &handle
, &sample
);
6158 perf_output_end(&handle
);
6162 * context_switch tracking
6165 struct perf_switch_event
{
6166 struct task_struct
*task
;
6167 struct task_struct
*next_prev
;
6170 struct perf_event_header header
;
6176 static int perf_event_switch_match(struct perf_event
*event
)
6178 return event
->attr
.context_switch
;
6181 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6183 struct perf_switch_event
*se
= data
;
6184 struct perf_output_handle handle
;
6185 struct perf_sample_data sample
;
6188 if (!perf_event_switch_match(event
))
6191 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6192 if (event
->ctx
->task
) {
6193 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6194 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6196 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6197 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6198 se
->event_id
.next_prev_pid
=
6199 perf_event_pid(event
, se
->next_prev
);
6200 se
->event_id
.next_prev_tid
=
6201 perf_event_tid(event
, se
->next_prev
);
6204 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6206 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6210 if (event
->ctx
->task
)
6211 perf_output_put(&handle
, se
->event_id
.header
);
6213 perf_output_put(&handle
, se
->event_id
);
6215 perf_event__output_id_sample(event
, &handle
, &sample
);
6217 perf_output_end(&handle
);
6220 static void perf_event_switch(struct task_struct
*task
,
6221 struct task_struct
*next_prev
, bool sched_in
)
6223 struct perf_switch_event switch_event
;
6225 /* N.B. caller checks nr_switch_events != 0 */
6227 switch_event
= (struct perf_switch_event
){
6229 .next_prev
= next_prev
,
6233 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6236 /* .next_prev_pid */
6237 /* .next_prev_tid */
6241 perf_event_aux(perf_event_switch_output
,
6247 * IRQ throttle logging
6250 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6252 struct perf_output_handle handle
;
6253 struct perf_sample_data sample
;
6257 struct perf_event_header header
;
6261 } throttle_event
= {
6263 .type
= PERF_RECORD_THROTTLE
,
6265 .size
= sizeof(throttle_event
),
6267 .time
= perf_event_clock(event
),
6268 .id
= primary_event_id(event
),
6269 .stream_id
= event
->id
,
6273 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6275 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6277 ret
= perf_output_begin(&handle
, event
,
6278 throttle_event
.header
.size
);
6282 perf_output_put(&handle
, throttle_event
);
6283 perf_event__output_id_sample(event
, &handle
, &sample
);
6284 perf_output_end(&handle
);
6287 static void perf_log_itrace_start(struct perf_event
*event
)
6289 struct perf_output_handle handle
;
6290 struct perf_sample_data sample
;
6291 struct perf_aux_event
{
6292 struct perf_event_header header
;
6299 event
= event
->parent
;
6301 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6302 event
->hw
.itrace_started
)
6305 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6306 rec
.header
.misc
= 0;
6307 rec
.header
.size
= sizeof(rec
);
6308 rec
.pid
= perf_event_pid(event
, current
);
6309 rec
.tid
= perf_event_tid(event
, current
);
6311 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6312 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6317 perf_output_put(&handle
, rec
);
6318 perf_event__output_id_sample(event
, &handle
, &sample
);
6320 perf_output_end(&handle
);
6324 * Generic event overflow handling, sampling.
6327 static int __perf_event_overflow(struct perf_event
*event
,
6328 int throttle
, struct perf_sample_data
*data
,
6329 struct pt_regs
*regs
)
6331 int events
= atomic_read(&event
->event_limit
);
6332 struct hw_perf_event
*hwc
= &event
->hw
;
6337 * Non-sampling counters might still use the PMI to fold short
6338 * hardware counters, ignore those.
6340 if (unlikely(!is_sampling_event(event
)))
6343 seq
= __this_cpu_read(perf_throttled_seq
);
6344 if (seq
!= hwc
->interrupts_seq
) {
6345 hwc
->interrupts_seq
= seq
;
6346 hwc
->interrupts
= 1;
6349 if (unlikely(throttle
6350 && hwc
->interrupts
>= max_samples_per_tick
)) {
6351 __this_cpu_inc(perf_throttled_count
);
6352 hwc
->interrupts
= MAX_INTERRUPTS
;
6353 perf_log_throttle(event
, 0);
6354 tick_nohz_full_kick();
6359 if (event
->attr
.freq
) {
6360 u64 now
= perf_clock();
6361 s64 delta
= now
- hwc
->freq_time_stamp
;
6363 hwc
->freq_time_stamp
= now
;
6365 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6366 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6370 * XXX event_limit might not quite work as expected on inherited
6374 event
->pending_kill
= POLL_IN
;
6375 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6377 event
->pending_kill
= POLL_HUP
;
6378 event
->pending_disable
= 1;
6379 irq_work_queue(&event
->pending
);
6382 if (event
->overflow_handler
)
6383 event
->overflow_handler(event
, data
, regs
);
6385 perf_event_output(event
, data
, regs
);
6387 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6388 event
->pending_wakeup
= 1;
6389 irq_work_queue(&event
->pending
);
6395 int perf_event_overflow(struct perf_event
*event
,
6396 struct perf_sample_data
*data
,
6397 struct pt_regs
*regs
)
6399 return __perf_event_overflow(event
, 1, data
, regs
);
6403 * Generic software event infrastructure
6406 struct swevent_htable
{
6407 struct swevent_hlist
*swevent_hlist
;
6408 struct mutex hlist_mutex
;
6411 /* Recursion avoidance in each contexts */
6412 int recursion
[PERF_NR_CONTEXTS
];
6415 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6418 * We directly increment event->count and keep a second value in
6419 * event->hw.period_left to count intervals. This period event
6420 * is kept in the range [-sample_period, 0] so that we can use the
6424 u64
perf_swevent_set_period(struct perf_event
*event
)
6426 struct hw_perf_event
*hwc
= &event
->hw
;
6427 u64 period
= hwc
->last_period
;
6431 hwc
->last_period
= hwc
->sample_period
;
6434 old
= val
= local64_read(&hwc
->period_left
);
6438 nr
= div64_u64(period
+ val
, period
);
6439 offset
= nr
* period
;
6441 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6447 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6448 struct perf_sample_data
*data
,
6449 struct pt_regs
*regs
)
6451 struct hw_perf_event
*hwc
= &event
->hw
;
6455 overflow
= perf_swevent_set_period(event
);
6457 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6460 for (; overflow
; overflow
--) {
6461 if (__perf_event_overflow(event
, throttle
,
6464 * We inhibit the overflow from happening when
6465 * hwc->interrupts == MAX_INTERRUPTS.
6473 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6474 struct perf_sample_data
*data
,
6475 struct pt_regs
*regs
)
6477 struct hw_perf_event
*hwc
= &event
->hw
;
6479 local64_add(nr
, &event
->count
);
6484 if (!is_sampling_event(event
))
6487 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6489 return perf_swevent_overflow(event
, 1, data
, regs
);
6491 data
->period
= event
->hw
.last_period
;
6493 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6494 return perf_swevent_overflow(event
, 1, data
, regs
);
6496 if (local64_add_negative(nr
, &hwc
->period_left
))
6499 perf_swevent_overflow(event
, 0, data
, regs
);
6502 static int perf_exclude_event(struct perf_event
*event
,
6503 struct pt_regs
*regs
)
6505 if (event
->hw
.state
& PERF_HES_STOPPED
)
6509 if (event
->attr
.exclude_user
&& user_mode(regs
))
6512 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6519 static int perf_swevent_match(struct perf_event
*event
,
6520 enum perf_type_id type
,
6522 struct perf_sample_data
*data
,
6523 struct pt_regs
*regs
)
6525 if (event
->attr
.type
!= type
)
6528 if (event
->attr
.config
!= event_id
)
6531 if (perf_exclude_event(event
, regs
))
6537 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6539 u64 val
= event_id
| (type
<< 32);
6541 return hash_64(val
, SWEVENT_HLIST_BITS
);
6544 static inline struct hlist_head
*
6545 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6547 u64 hash
= swevent_hash(type
, event_id
);
6549 return &hlist
->heads
[hash
];
6552 /* For the read side: events when they trigger */
6553 static inline struct hlist_head
*
6554 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6556 struct swevent_hlist
*hlist
;
6558 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6562 return __find_swevent_head(hlist
, type
, event_id
);
6565 /* For the event head insertion and removal in the hlist */
6566 static inline struct hlist_head
*
6567 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6569 struct swevent_hlist
*hlist
;
6570 u32 event_id
= event
->attr
.config
;
6571 u64 type
= event
->attr
.type
;
6574 * Event scheduling is always serialized against hlist allocation
6575 * and release. Which makes the protected version suitable here.
6576 * The context lock guarantees that.
6578 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6579 lockdep_is_held(&event
->ctx
->lock
));
6583 return __find_swevent_head(hlist
, type
, event_id
);
6586 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6588 struct perf_sample_data
*data
,
6589 struct pt_regs
*regs
)
6591 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6592 struct perf_event
*event
;
6593 struct hlist_head
*head
;
6596 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6600 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6601 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6602 perf_swevent_event(event
, nr
, data
, regs
);
6608 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6610 int perf_swevent_get_recursion_context(void)
6612 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6614 return get_recursion_context(swhash
->recursion
);
6616 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6618 inline void perf_swevent_put_recursion_context(int rctx
)
6620 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6622 put_recursion_context(swhash
->recursion
, rctx
);
6625 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6627 struct perf_sample_data data
;
6629 if (WARN_ON_ONCE(!regs
))
6632 perf_sample_data_init(&data
, addr
, 0);
6633 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6636 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6640 preempt_disable_notrace();
6641 rctx
= perf_swevent_get_recursion_context();
6642 if (unlikely(rctx
< 0))
6645 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6647 perf_swevent_put_recursion_context(rctx
);
6649 preempt_enable_notrace();
6652 static void perf_swevent_read(struct perf_event
*event
)
6656 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6658 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6659 struct hw_perf_event
*hwc
= &event
->hw
;
6660 struct hlist_head
*head
;
6662 if (is_sampling_event(event
)) {
6663 hwc
->last_period
= hwc
->sample_period
;
6664 perf_swevent_set_period(event
);
6667 hwc
->state
= !(flags
& PERF_EF_START
);
6669 head
= find_swevent_head(swhash
, event
);
6670 if (WARN_ON_ONCE(!head
))
6673 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6674 perf_event_update_userpage(event
);
6679 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6681 hlist_del_rcu(&event
->hlist_entry
);
6684 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6686 event
->hw
.state
= 0;
6689 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6691 event
->hw
.state
= PERF_HES_STOPPED
;
6694 /* Deref the hlist from the update side */
6695 static inline struct swevent_hlist
*
6696 swevent_hlist_deref(struct swevent_htable
*swhash
)
6698 return rcu_dereference_protected(swhash
->swevent_hlist
,
6699 lockdep_is_held(&swhash
->hlist_mutex
));
6702 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6704 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6709 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6710 kfree_rcu(hlist
, rcu_head
);
6713 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6715 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6717 mutex_lock(&swhash
->hlist_mutex
);
6719 if (!--swhash
->hlist_refcount
)
6720 swevent_hlist_release(swhash
);
6722 mutex_unlock(&swhash
->hlist_mutex
);
6725 static void swevent_hlist_put(struct perf_event
*event
)
6729 for_each_possible_cpu(cpu
)
6730 swevent_hlist_put_cpu(event
, cpu
);
6733 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6735 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6738 mutex_lock(&swhash
->hlist_mutex
);
6739 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6740 struct swevent_hlist
*hlist
;
6742 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6747 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6749 swhash
->hlist_refcount
++;
6751 mutex_unlock(&swhash
->hlist_mutex
);
6756 static int swevent_hlist_get(struct perf_event
*event
)
6759 int cpu
, failed_cpu
;
6762 for_each_possible_cpu(cpu
) {
6763 err
= swevent_hlist_get_cpu(event
, cpu
);
6773 for_each_possible_cpu(cpu
) {
6774 if (cpu
== failed_cpu
)
6776 swevent_hlist_put_cpu(event
, cpu
);
6783 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6785 static void sw_perf_event_destroy(struct perf_event
*event
)
6787 u64 event_id
= event
->attr
.config
;
6789 WARN_ON(event
->parent
);
6791 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6792 swevent_hlist_put(event
);
6795 static int perf_swevent_init(struct perf_event
*event
)
6797 u64 event_id
= event
->attr
.config
;
6799 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6803 * no branch sampling for software events
6805 if (has_branch_stack(event
))
6809 case PERF_COUNT_SW_CPU_CLOCK
:
6810 case PERF_COUNT_SW_TASK_CLOCK
:
6817 if (event_id
>= PERF_COUNT_SW_MAX
)
6820 if (!event
->parent
) {
6823 err
= swevent_hlist_get(event
);
6827 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6828 event
->destroy
= sw_perf_event_destroy
;
6834 static struct pmu perf_swevent
= {
6835 .task_ctx_nr
= perf_sw_context
,
6837 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6839 .event_init
= perf_swevent_init
,
6840 .add
= perf_swevent_add
,
6841 .del
= perf_swevent_del
,
6842 .start
= perf_swevent_start
,
6843 .stop
= perf_swevent_stop
,
6844 .read
= perf_swevent_read
,
6847 #ifdef CONFIG_EVENT_TRACING
6849 static int perf_tp_filter_match(struct perf_event
*event
,
6850 struct perf_sample_data
*data
)
6852 void *record
= data
->raw
->data
;
6854 /* only top level events have filters set */
6856 event
= event
->parent
;
6858 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6863 static int perf_tp_event_match(struct perf_event
*event
,
6864 struct perf_sample_data
*data
,
6865 struct pt_regs
*regs
)
6867 if (event
->hw
.state
& PERF_HES_STOPPED
)
6870 * All tracepoints are from kernel-space.
6872 if (event
->attr
.exclude_kernel
)
6875 if (!perf_tp_filter_match(event
, data
))
6881 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6882 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6883 struct task_struct
*task
)
6885 struct perf_sample_data data
;
6886 struct perf_event
*event
;
6888 struct perf_raw_record raw
= {
6893 perf_sample_data_init(&data
, addr
, 0);
6896 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6897 if (perf_tp_event_match(event
, &data
, regs
))
6898 perf_swevent_event(event
, count
, &data
, regs
);
6902 * If we got specified a target task, also iterate its context and
6903 * deliver this event there too.
6905 if (task
&& task
!= current
) {
6906 struct perf_event_context
*ctx
;
6907 struct trace_entry
*entry
= record
;
6910 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6914 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6915 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6917 if (event
->attr
.config
!= entry
->type
)
6919 if (perf_tp_event_match(event
, &data
, regs
))
6920 perf_swevent_event(event
, count
, &data
, regs
);
6926 perf_swevent_put_recursion_context(rctx
);
6928 EXPORT_SYMBOL_GPL(perf_tp_event
);
6930 static void tp_perf_event_destroy(struct perf_event
*event
)
6932 perf_trace_destroy(event
);
6935 static int perf_tp_event_init(struct perf_event
*event
)
6939 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6943 * no branch sampling for tracepoint events
6945 if (has_branch_stack(event
))
6948 err
= perf_trace_init(event
);
6952 event
->destroy
= tp_perf_event_destroy
;
6957 static struct pmu perf_tracepoint
= {
6958 .task_ctx_nr
= perf_sw_context
,
6960 .event_init
= perf_tp_event_init
,
6961 .add
= perf_trace_add
,
6962 .del
= perf_trace_del
,
6963 .start
= perf_swevent_start
,
6964 .stop
= perf_swevent_stop
,
6965 .read
= perf_swevent_read
,
6968 static inline void perf_tp_register(void)
6970 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
6973 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6978 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6981 filter_str
= strndup_user(arg
, PAGE_SIZE
);
6982 if (IS_ERR(filter_str
))
6983 return PTR_ERR(filter_str
);
6985 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
6991 static void perf_event_free_filter(struct perf_event
*event
)
6993 ftrace_profile_free_filter(event
);
6996 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
6998 struct bpf_prog
*prog
;
7000 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7003 if (event
->tp_event
->prog
)
7006 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
7007 /* bpf programs can only be attached to u/kprobes */
7010 prog
= bpf_prog_get(prog_fd
);
7012 return PTR_ERR(prog
);
7014 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7015 /* valid fd, but invalid bpf program type */
7020 event
->tp_event
->prog
= prog
;
7025 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7027 struct bpf_prog
*prog
;
7029 if (!event
->tp_event
)
7032 prog
= event
->tp_event
->prog
;
7034 event
->tp_event
->prog
= NULL
;
7041 static inline void perf_tp_register(void)
7045 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7050 static void perf_event_free_filter(struct perf_event
*event
)
7054 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7059 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7062 #endif /* CONFIG_EVENT_TRACING */
7064 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7065 void perf_bp_event(struct perf_event
*bp
, void *data
)
7067 struct perf_sample_data sample
;
7068 struct pt_regs
*regs
= data
;
7070 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7072 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7073 perf_swevent_event(bp
, 1, &sample
, regs
);
7078 * hrtimer based swevent callback
7081 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7083 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7084 struct perf_sample_data data
;
7085 struct pt_regs
*regs
;
7086 struct perf_event
*event
;
7089 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7091 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7092 return HRTIMER_NORESTART
;
7094 event
->pmu
->read(event
);
7096 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7097 regs
= get_irq_regs();
7099 if (regs
&& !perf_exclude_event(event
, regs
)) {
7100 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7101 if (__perf_event_overflow(event
, 1, &data
, regs
))
7102 ret
= HRTIMER_NORESTART
;
7105 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7106 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7111 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7113 struct hw_perf_event
*hwc
= &event
->hw
;
7116 if (!is_sampling_event(event
))
7119 period
= local64_read(&hwc
->period_left
);
7124 local64_set(&hwc
->period_left
, 0);
7126 period
= max_t(u64
, 10000, hwc
->sample_period
);
7128 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7129 HRTIMER_MODE_REL_PINNED
);
7132 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7134 struct hw_perf_event
*hwc
= &event
->hw
;
7136 if (is_sampling_event(event
)) {
7137 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7138 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7140 hrtimer_cancel(&hwc
->hrtimer
);
7144 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7146 struct hw_perf_event
*hwc
= &event
->hw
;
7148 if (!is_sampling_event(event
))
7151 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7152 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7155 * Since hrtimers have a fixed rate, we can do a static freq->period
7156 * mapping and avoid the whole period adjust feedback stuff.
7158 if (event
->attr
.freq
) {
7159 long freq
= event
->attr
.sample_freq
;
7161 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7162 hwc
->sample_period
= event
->attr
.sample_period
;
7163 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7164 hwc
->last_period
= hwc
->sample_period
;
7165 event
->attr
.freq
= 0;
7170 * Software event: cpu wall time clock
7173 static void cpu_clock_event_update(struct perf_event
*event
)
7178 now
= local_clock();
7179 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7180 local64_add(now
- prev
, &event
->count
);
7183 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7185 local64_set(&event
->hw
.prev_count
, local_clock());
7186 perf_swevent_start_hrtimer(event
);
7189 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7191 perf_swevent_cancel_hrtimer(event
);
7192 cpu_clock_event_update(event
);
7195 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7197 if (flags
& PERF_EF_START
)
7198 cpu_clock_event_start(event
, flags
);
7199 perf_event_update_userpage(event
);
7204 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7206 cpu_clock_event_stop(event
, flags
);
7209 static void cpu_clock_event_read(struct perf_event
*event
)
7211 cpu_clock_event_update(event
);
7214 static int cpu_clock_event_init(struct perf_event
*event
)
7216 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7219 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7223 * no branch sampling for software events
7225 if (has_branch_stack(event
))
7228 perf_swevent_init_hrtimer(event
);
7233 static struct pmu perf_cpu_clock
= {
7234 .task_ctx_nr
= perf_sw_context
,
7236 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7238 .event_init
= cpu_clock_event_init
,
7239 .add
= cpu_clock_event_add
,
7240 .del
= cpu_clock_event_del
,
7241 .start
= cpu_clock_event_start
,
7242 .stop
= cpu_clock_event_stop
,
7243 .read
= cpu_clock_event_read
,
7247 * Software event: task time clock
7250 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7255 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7257 local64_add(delta
, &event
->count
);
7260 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7262 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7263 perf_swevent_start_hrtimer(event
);
7266 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7268 perf_swevent_cancel_hrtimer(event
);
7269 task_clock_event_update(event
, event
->ctx
->time
);
7272 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7274 if (flags
& PERF_EF_START
)
7275 task_clock_event_start(event
, flags
);
7276 perf_event_update_userpage(event
);
7281 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7283 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7286 static void task_clock_event_read(struct perf_event
*event
)
7288 u64 now
= perf_clock();
7289 u64 delta
= now
- event
->ctx
->timestamp
;
7290 u64 time
= event
->ctx
->time
+ delta
;
7292 task_clock_event_update(event
, time
);
7295 static int task_clock_event_init(struct perf_event
*event
)
7297 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7300 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7304 * no branch sampling for software events
7306 if (has_branch_stack(event
))
7309 perf_swevent_init_hrtimer(event
);
7314 static struct pmu perf_task_clock
= {
7315 .task_ctx_nr
= perf_sw_context
,
7317 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7319 .event_init
= task_clock_event_init
,
7320 .add
= task_clock_event_add
,
7321 .del
= task_clock_event_del
,
7322 .start
= task_clock_event_start
,
7323 .stop
= task_clock_event_stop
,
7324 .read
= task_clock_event_read
,
7327 static void perf_pmu_nop_void(struct pmu
*pmu
)
7331 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7335 static int perf_pmu_nop_int(struct pmu
*pmu
)
7340 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7342 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7344 __this_cpu_write(nop_txn_flags
, flags
);
7346 if (flags
& ~PERF_PMU_TXN_ADD
)
7349 perf_pmu_disable(pmu
);
7352 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7354 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7356 __this_cpu_write(nop_txn_flags
, 0);
7358 if (flags
& ~PERF_PMU_TXN_ADD
)
7361 perf_pmu_enable(pmu
);
7365 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7367 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7369 __this_cpu_write(nop_txn_flags
, 0);
7371 if (flags
& ~PERF_PMU_TXN_ADD
)
7374 perf_pmu_enable(pmu
);
7377 static int perf_event_idx_default(struct perf_event
*event
)
7383 * Ensures all contexts with the same task_ctx_nr have the same
7384 * pmu_cpu_context too.
7386 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7393 list_for_each_entry(pmu
, &pmus
, entry
) {
7394 if (pmu
->task_ctx_nr
== ctxn
)
7395 return pmu
->pmu_cpu_context
;
7401 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7405 for_each_possible_cpu(cpu
) {
7406 struct perf_cpu_context
*cpuctx
;
7408 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7410 if (cpuctx
->unique_pmu
== old_pmu
)
7411 cpuctx
->unique_pmu
= pmu
;
7415 static void free_pmu_context(struct pmu
*pmu
)
7419 mutex_lock(&pmus_lock
);
7421 * Like a real lame refcount.
7423 list_for_each_entry(i
, &pmus
, entry
) {
7424 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7425 update_pmu_context(i
, pmu
);
7430 free_percpu(pmu
->pmu_cpu_context
);
7432 mutex_unlock(&pmus_lock
);
7434 static struct idr pmu_idr
;
7437 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7439 struct pmu
*pmu
= dev_get_drvdata(dev
);
7441 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7443 static DEVICE_ATTR_RO(type
);
7446 perf_event_mux_interval_ms_show(struct device
*dev
,
7447 struct device_attribute
*attr
,
7450 struct pmu
*pmu
= dev_get_drvdata(dev
);
7452 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7455 static DEFINE_MUTEX(mux_interval_mutex
);
7458 perf_event_mux_interval_ms_store(struct device
*dev
,
7459 struct device_attribute
*attr
,
7460 const char *buf
, size_t count
)
7462 struct pmu
*pmu
= dev_get_drvdata(dev
);
7463 int timer
, cpu
, ret
;
7465 ret
= kstrtoint(buf
, 0, &timer
);
7472 /* same value, noting to do */
7473 if (timer
== pmu
->hrtimer_interval_ms
)
7476 mutex_lock(&mux_interval_mutex
);
7477 pmu
->hrtimer_interval_ms
= timer
;
7479 /* update all cpuctx for this PMU */
7481 for_each_online_cpu(cpu
) {
7482 struct perf_cpu_context
*cpuctx
;
7483 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7484 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7486 cpu_function_call(cpu
,
7487 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7490 mutex_unlock(&mux_interval_mutex
);
7494 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7496 static struct attribute
*pmu_dev_attrs
[] = {
7497 &dev_attr_type
.attr
,
7498 &dev_attr_perf_event_mux_interval_ms
.attr
,
7501 ATTRIBUTE_GROUPS(pmu_dev
);
7503 static int pmu_bus_running
;
7504 static struct bus_type pmu_bus
= {
7505 .name
= "event_source",
7506 .dev_groups
= pmu_dev_groups
,
7509 static void pmu_dev_release(struct device
*dev
)
7514 static int pmu_dev_alloc(struct pmu
*pmu
)
7518 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7522 pmu
->dev
->groups
= pmu
->attr_groups
;
7523 device_initialize(pmu
->dev
);
7524 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7528 dev_set_drvdata(pmu
->dev
, pmu
);
7529 pmu
->dev
->bus
= &pmu_bus
;
7530 pmu
->dev
->release
= pmu_dev_release
;
7531 ret
= device_add(pmu
->dev
);
7539 put_device(pmu
->dev
);
7543 static struct lock_class_key cpuctx_mutex
;
7544 static struct lock_class_key cpuctx_lock
;
7546 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7550 mutex_lock(&pmus_lock
);
7552 pmu
->pmu_disable_count
= alloc_percpu(int);
7553 if (!pmu
->pmu_disable_count
)
7562 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7570 if (pmu_bus_running
) {
7571 ret
= pmu_dev_alloc(pmu
);
7577 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7578 if (pmu
->pmu_cpu_context
)
7579 goto got_cpu_context
;
7582 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7583 if (!pmu
->pmu_cpu_context
)
7586 for_each_possible_cpu(cpu
) {
7587 struct perf_cpu_context
*cpuctx
;
7589 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7590 __perf_event_init_context(&cpuctx
->ctx
);
7591 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7592 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7593 cpuctx
->ctx
.pmu
= pmu
;
7595 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7597 cpuctx
->unique_pmu
= pmu
;
7601 if (!pmu
->start_txn
) {
7602 if (pmu
->pmu_enable
) {
7604 * If we have pmu_enable/pmu_disable calls, install
7605 * transaction stubs that use that to try and batch
7606 * hardware accesses.
7608 pmu
->start_txn
= perf_pmu_start_txn
;
7609 pmu
->commit_txn
= perf_pmu_commit_txn
;
7610 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7612 pmu
->start_txn
= perf_pmu_nop_txn
;
7613 pmu
->commit_txn
= perf_pmu_nop_int
;
7614 pmu
->cancel_txn
= perf_pmu_nop_void
;
7618 if (!pmu
->pmu_enable
) {
7619 pmu
->pmu_enable
= perf_pmu_nop_void
;
7620 pmu
->pmu_disable
= perf_pmu_nop_void
;
7623 if (!pmu
->event_idx
)
7624 pmu
->event_idx
= perf_event_idx_default
;
7626 list_add_rcu(&pmu
->entry
, &pmus
);
7627 atomic_set(&pmu
->exclusive_cnt
, 0);
7630 mutex_unlock(&pmus_lock
);
7635 device_del(pmu
->dev
);
7636 put_device(pmu
->dev
);
7639 if (pmu
->type
>= PERF_TYPE_MAX
)
7640 idr_remove(&pmu_idr
, pmu
->type
);
7643 free_percpu(pmu
->pmu_disable_count
);
7646 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7648 void perf_pmu_unregister(struct pmu
*pmu
)
7650 mutex_lock(&pmus_lock
);
7651 list_del_rcu(&pmu
->entry
);
7652 mutex_unlock(&pmus_lock
);
7655 * We dereference the pmu list under both SRCU and regular RCU, so
7656 * synchronize against both of those.
7658 synchronize_srcu(&pmus_srcu
);
7661 free_percpu(pmu
->pmu_disable_count
);
7662 if (pmu
->type
>= PERF_TYPE_MAX
)
7663 idr_remove(&pmu_idr
, pmu
->type
);
7664 device_del(pmu
->dev
);
7665 put_device(pmu
->dev
);
7666 free_pmu_context(pmu
);
7668 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7670 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7672 struct perf_event_context
*ctx
= NULL
;
7675 if (!try_module_get(pmu
->module
))
7678 if (event
->group_leader
!= event
) {
7680 * This ctx->mutex can nest when we're called through
7681 * inheritance. See the perf_event_ctx_lock_nested() comment.
7683 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7684 SINGLE_DEPTH_NESTING
);
7689 ret
= pmu
->event_init(event
);
7692 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7695 module_put(pmu
->module
);
7700 static struct pmu
*perf_init_event(struct perf_event
*event
)
7702 struct pmu
*pmu
= NULL
;
7706 idx
= srcu_read_lock(&pmus_srcu
);
7709 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7712 ret
= perf_try_init_event(pmu
, event
);
7718 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7719 ret
= perf_try_init_event(pmu
, event
);
7723 if (ret
!= -ENOENT
) {
7728 pmu
= ERR_PTR(-ENOENT
);
7730 srcu_read_unlock(&pmus_srcu
, idx
);
7735 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7740 if (is_cgroup_event(event
))
7741 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7744 static void account_event(struct perf_event
*event
)
7751 if (event
->attach_state
& PERF_ATTACH_TASK
)
7753 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7754 atomic_inc(&nr_mmap_events
);
7755 if (event
->attr
.comm
)
7756 atomic_inc(&nr_comm_events
);
7757 if (event
->attr
.task
)
7758 atomic_inc(&nr_task_events
);
7759 if (event
->attr
.freq
) {
7760 if (atomic_inc_return(&nr_freq_events
) == 1)
7761 tick_nohz_full_kick_all();
7763 if (event
->attr
.context_switch
) {
7764 atomic_inc(&nr_switch_events
);
7767 if (has_branch_stack(event
))
7769 if (is_cgroup_event(event
))
7773 static_key_slow_inc(&perf_sched_events
.key
);
7775 account_event_cpu(event
, event
->cpu
);
7779 * Allocate and initialize a event structure
7781 static struct perf_event
*
7782 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7783 struct task_struct
*task
,
7784 struct perf_event
*group_leader
,
7785 struct perf_event
*parent_event
,
7786 perf_overflow_handler_t overflow_handler
,
7787 void *context
, int cgroup_fd
)
7790 struct perf_event
*event
;
7791 struct hw_perf_event
*hwc
;
7794 if ((unsigned)cpu
>= nr_cpu_ids
) {
7795 if (!task
|| cpu
!= -1)
7796 return ERR_PTR(-EINVAL
);
7799 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7801 return ERR_PTR(-ENOMEM
);
7804 * Single events are their own group leaders, with an
7805 * empty sibling list:
7808 group_leader
= event
;
7810 mutex_init(&event
->child_mutex
);
7811 INIT_LIST_HEAD(&event
->child_list
);
7813 INIT_LIST_HEAD(&event
->group_entry
);
7814 INIT_LIST_HEAD(&event
->event_entry
);
7815 INIT_LIST_HEAD(&event
->sibling_list
);
7816 INIT_LIST_HEAD(&event
->rb_entry
);
7817 INIT_LIST_HEAD(&event
->active_entry
);
7818 INIT_HLIST_NODE(&event
->hlist_entry
);
7821 init_waitqueue_head(&event
->waitq
);
7822 init_irq_work(&event
->pending
, perf_pending_event
);
7824 mutex_init(&event
->mmap_mutex
);
7826 atomic_long_set(&event
->refcount
, 1);
7828 event
->attr
= *attr
;
7829 event
->group_leader
= group_leader
;
7833 event
->parent
= parent_event
;
7835 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7836 event
->id
= atomic64_inc_return(&perf_event_id
);
7838 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7841 event
->attach_state
= PERF_ATTACH_TASK
;
7843 * XXX pmu::event_init needs to know what task to account to
7844 * and we cannot use the ctx information because we need the
7845 * pmu before we get a ctx.
7847 event
->hw
.target
= task
;
7850 event
->clock
= &local_clock
;
7852 event
->clock
= parent_event
->clock
;
7854 if (!overflow_handler
&& parent_event
) {
7855 overflow_handler
= parent_event
->overflow_handler
;
7856 context
= parent_event
->overflow_handler_context
;
7859 event
->overflow_handler
= overflow_handler
;
7860 event
->overflow_handler_context
= context
;
7862 perf_event__state_init(event
);
7867 hwc
->sample_period
= attr
->sample_period
;
7868 if (attr
->freq
&& attr
->sample_freq
)
7869 hwc
->sample_period
= 1;
7870 hwc
->last_period
= hwc
->sample_period
;
7872 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7875 * we currently do not support PERF_FORMAT_GROUP on inherited events
7877 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7880 if (!has_branch_stack(event
))
7881 event
->attr
.branch_sample_type
= 0;
7883 if (cgroup_fd
!= -1) {
7884 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7889 pmu
= perf_init_event(event
);
7892 else if (IS_ERR(pmu
)) {
7897 err
= exclusive_event_init(event
);
7901 if (!event
->parent
) {
7902 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7903 err
= get_callchain_buffers();
7912 exclusive_event_destroy(event
);
7916 event
->destroy(event
);
7917 module_put(pmu
->module
);
7919 if (is_cgroup_event(event
))
7920 perf_detach_cgroup(event
);
7922 put_pid_ns(event
->ns
);
7925 return ERR_PTR(err
);
7928 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
7929 struct perf_event_attr
*attr
)
7934 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
7938 * zero the full structure, so that a short copy will be nice.
7940 memset(attr
, 0, sizeof(*attr
));
7942 ret
= get_user(size
, &uattr
->size
);
7946 if (size
> PAGE_SIZE
) /* silly large */
7949 if (!size
) /* abi compat */
7950 size
= PERF_ATTR_SIZE_VER0
;
7952 if (size
< PERF_ATTR_SIZE_VER0
)
7956 * If we're handed a bigger struct than we know of,
7957 * ensure all the unknown bits are 0 - i.e. new
7958 * user-space does not rely on any kernel feature
7959 * extensions we dont know about yet.
7961 if (size
> sizeof(*attr
)) {
7962 unsigned char __user
*addr
;
7963 unsigned char __user
*end
;
7966 addr
= (void __user
*)uattr
+ sizeof(*attr
);
7967 end
= (void __user
*)uattr
+ size
;
7969 for (; addr
< end
; addr
++) {
7970 ret
= get_user(val
, addr
);
7976 size
= sizeof(*attr
);
7979 ret
= copy_from_user(attr
, uattr
, size
);
7983 if (attr
->__reserved_1
)
7986 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
7989 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
7992 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
7993 u64 mask
= attr
->branch_sample_type
;
7995 /* only using defined bits */
7996 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
7999 /* at least one branch bit must be set */
8000 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
8003 /* propagate priv level, when not set for branch */
8004 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
8006 /* exclude_kernel checked on syscall entry */
8007 if (!attr
->exclude_kernel
)
8008 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8010 if (!attr
->exclude_user
)
8011 mask
|= PERF_SAMPLE_BRANCH_USER
;
8013 if (!attr
->exclude_hv
)
8014 mask
|= PERF_SAMPLE_BRANCH_HV
;
8016 * adjust user setting (for HW filter setup)
8018 attr
->branch_sample_type
= mask
;
8020 /* privileged levels capture (kernel, hv): check permissions */
8021 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8022 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8026 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8027 ret
= perf_reg_validate(attr
->sample_regs_user
);
8032 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8033 if (!arch_perf_have_user_stack_dump())
8037 * We have __u32 type for the size, but so far
8038 * we can only use __u16 as maximum due to the
8039 * __u16 sample size limit.
8041 if (attr
->sample_stack_user
>= USHRT_MAX
)
8043 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8047 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8048 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8053 put_user(sizeof(*attr
), &uattr
->size
);
8059 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8061 struct ring_buffer
*rb
= NULL
;
8067 /* don't allow circular references */
8068 if (event
== output_event
)
8072 * Don't allow cross-cpu buffers
8074 if (output_event
->cpu
!= event
->cpu
)
8078 * If its not a per-cpu rb, it must be the same task.
8080 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8084 * Mixing clocks in the same buffer is trouble you don't need.
8086 if (output_event
->clock
!= event
->clock
)
8090 * If both events generate aux data, they must be on the same PMU
8092 if (has_aux(event
) && has_aux(output_event
) &&
8093 event
->pmu
!= output_event
->pmu
)
8097 mutex_lock(&event
->mmap_mutex
);
8098 /* Can't redirect output if we've got an active mmap() */
8099 if (atomic_read(&event
->mmap_count
))
8103 /* get the rb we want to redirect to */
8104 rb
= ring_buffer_get(output_event
);
8109 ring_buffer_attach(event
, rb
);
8113 mutex_unlock(&event
->mmap_mutex
);
8119 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8125 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8128 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8130 bool nmi_safe
= false;
8133 case CLOCK_MONOTONIC
:
8134 event
->clock
= &ktime_get_mono_fast_ns
;
8138 case CLOCK_MONOTONIC_RAW
:
8139 event
->clock
= &ktime_get_raw_fast_ns
;
8143 case CLOCK_REALTIME
:
8144 event
->clock
= &ktime_get_real_ns
;
8147 case CLOCK_BOOTTIME
:
8148 event
->clock
= &ktime_get_boot_ns
;
8152 event
->clock
= &ktime_get_tai_ns
;
8159 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8166 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8168 * @attr_uptr: event_id type attributes for monitoring/sampling
8171 * @group_fd: group leader event fd
8173 SYSCALL_DEFINE5(perf_event_open
,
8174 struct perf_event_attr __user
*, attr_uptr
,
8175 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8177 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8178 struct perf_event
*event
, *sibling
;
8179 struct perf_event_attr attr
;
8180 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8181 struct file
*event_file
= NULL
;
8182 struct fd group
= {NULL
, 0};
8183 struct task_struct
*task
= NULL
;
8188 int f_flags
= O_RDWR
;
8191 /* for future expandability... */
8192 if (flags
& ~PERF_FLAG_ALL
)
8195 err
= perf_copy_attr(attr_uptr
, &attr
);
8199 if (!attr
.exclude_kernel
) {
8200 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8205 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8208 if (attr
.sample_period
& (1ULL << 63))
8213 * In cgroup mode, the pid argument is used to pass the fd
8214 * opened to the cgroup directory in cgroupfs. The cpu argument
8215 * designates the cpu on which to monitor threads from that
8218 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8221 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8222 f_flags
|= O_CLOEXEC
;
8224 event_fd
= get_unused_fd_flags(f_flags
);
8228 if (group_fd
!= -1) {
8229 err
= perf_fget_light(group_fd
, &group
);
8232 group_leader
= group
.file
->private_data
;
8233 if (flags
& PERF_FLAG_FD_OUTPUT
)
8234 output_event
= group_leader
;
8235 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8236 group_leader
= NULL
;
8239 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8240 task
= find_lively_task_by_vpid(pid
);
8242 err
= PTR_ERR(task
);
8247 if (task
&& group_leader
&&
8248 group_leader
->attr
.inherit
!= attr
.inherit
) {
8255 if (flags
& PERF_FLAG_PID_CGROUP
)
8258 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8259 NULL
, NULL
, cgroup_fd
);
8260 if (IS_ERR(event
)) {
8261 err
= PTR_ERR(event
);
8265 if (is_sampling_event(event
)) {
8266 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8272 account_event(event
);
8275 * Special case software events and allow them to be part of
8276 * any hardware group.
8280 if (attr
.use_clockid
) {
8281 err
= perf_event_set_clock(event
, attr
.clockid
);
8287 (is_software_event(event
) != is_software_event(group_leader
))) {
8288 if (is_software_event(event
)) {
8290 * If event and group_leader are not both a software
8291 * event, and event is, then group leader is not.
8293 * Allow the addition of software events to !software
8294 * groups, this is safe because software events never
8297 pmu
= group_leader
->pmu
;
8298 } else if (is_software_event(group_leader
) &&
8299 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8301 * In case the group is a pure software group, and we
8302 * try to add a hardware event, move the whole group to
8303 * the hardware context.
8310 * Get the target context (task or percpu):
8312 ctx
= find_get_context(pmu
, task
, event
);
8318 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8324 put_task_struct(task
);
8329 * Look up the group leader (we will attach this event to it):
8335 * Do not allow a recursive hierarchy (this new sibling
8336 * becoming part of another group-sibling):
8338 if (group_leader
->group_leader
!= group_leader
)
8341 /* All events in a group should have the same clock */
8342 if (group_leader
->clock
!= event
->clock
)
8346 * Do not allow to attach to a group in a different
8347 * task or CPU context:
8351 * Make sure we're both on the same task, or both
8354 if (group_leader
->ctx
->task
!= ctx
->task
)
8358 * Make sure we're both events for the same CPU;
8359 * grouping events for different CPUs is broken; since
8360 * you can never concurrently schedule them anyhow.
8362 if (group_leader
->cpu
!= event
->cpu
)
8365 if (group_leader
->ctx
!= ctx
)
8370 * Only a group leader can be exclusive or pinned
8372 if (attr
.exclusive
|| attr
.pinned
)
8377 err
= perf_event_set_output(event
, output_event
);
8382 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8384 if (IS_ERR(event_file
)) {
8385 err
= PTR_ERR(event_file
);
8390 gctx
= group_leader
->ctx
;
8391 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8393 mutex_lock(&ctx
->mutex
);
8396 if (!perf_event_validate_size(event
)) {
8402 * Must be under the same ctx::mutex as perf_install_in_context(),
8403 * because we need to serialize with concurrent event creation.
8405 if (!exclusive_event_installable(event
, ctx
)) {
8406 /* exclusive and group stuff are assumed mutually exclusive */
8407 WARN_ON_ONCE(move_group
);
8413 WARN_ON_ONCE(ctx
->parent_ctx
);
8417 * See perf_event_ctx_lock() for comments on the details
8418 * of swizzling perf_event::ctx.
8420 perf_remove_from_context(group_leader
, 0);
8422 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8424 perf_remove_from_context(sibling
, 0);
8429 * Wait for everybody to stop referencing the events through
8430 * the old lists, before installing it on new lists.
8435 * Install the group siblings before the group leader.
8437 * Because a group leader will try and install the entire group
8438 * (through the sibling list, which is still in-tact), we can
8439 * end up with siblings installed in the wrong context.
8441 * By installing siblings first we NO-OP because they're not
8442 * reachable through the group lists.
8444 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8446 perf_event__state_init(sibling
);
8447 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8452 * Removing from the context ends up with disabled
8453 * event. What we want here is event in the initial
8454 * startup state, ready to be add into new context.
8456 perf_event__state_init(group_leader
);
8457 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8461 * Now that all events are installed in @ctx, nothing
8462 * references @gctx anymore, so drop the last reference we have
8469 * Precalculate sample_data sizes; do while holding ctx::mutex such
8470 * that we're serialized against further additions and before
8471 * perf_install_in_context() which is the point the event is active and
8472 * can use these values.
8474 perf_event__header_size(event
);
8475 perf_event__id_header_size(event
);
8477 event
->owner
= current
;
8479 perf_install_in_context(ctx
, event
, event
->cpu
);
8480 perf_unpin_context(ctx
);
8483 mutex_unlock(&gctx
->mutex
);
8484 mutex_unlock(&ctx
->mutex
);
8488 mutex_lock(¤t
->perf_event_mutex
);
8489 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8490 mutex_unlock(¤t
->perf_event_mutex
);
8493 * Drop the reference on the group_event after placing the
8494 * new event on the sibling_list. This ensures destruction
8495 * of the group leader will find the pointer to itself in
8496 * perf_group_detach().
8499 fd_install(event_fd
, event_file
);
8504 mutex_unlock(&gctx
->mutex
);
8505 mutex_unlock(&ctx
->mutex
);
8509 perf_unpin_context(ctx
);
8517 put_task_struct(task
);
8521 put_unused_fd(event_fd
);
8526 * perf_event_create_kernel_counter
8528 * @attr: attributes of the counter to create
8529 * @cpu: cpu in which the counter is bound
8530 * @task: task to profile (NULL for percpu)
8533 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8534 struct task_struct
*task
,
8535 perf_overflow_handler_t overflow_handler
,
8538 struct perf_event_context
*ctx
;
8539 struct perf_event
*event
;
8543 * Get the target context (task or percpu):
8546 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8547 overflow_handler
, context
, -1);
8548 if (IS_ERR(event
)) {
8549 err
= PTR_ERR(event
);
8553 /* Mark owner so we could distinguish it from user events. */
8554 event
->owner
= TASK_TOMBSTONE
;
8556 account_event(event
);
8558 ctx
= find_get_context(event
->pmu
, task
, event
);
8564 WARN_ON_ONCE(ctx
->parent_ctx
);
8565 mutex_lock(&ctx
->mutex
);
8566 if (!exclusive_event_installable(event
, ctx
)) {
8567 mutex_unlock(&ctx
->mutex
);
8568 perf_unpin_context(ctx
);
8574 perf_install_in_context(ctx
, event
, cpu
);
8575 perf_unpin_context(ctx
);
8576 mutex_unlock(&ctx
->mutex
);
8583 return ERR_PTR(err
);
8585 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8587 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8589 struct perf_event_context
*src_ctx
;
8590 struct perf_event_context
*dst_ctx
;
8591 struct perf_event
*event
, *tmp
;
8594 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8595 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8598 * See perf_event_ctx_lock() for comments on the details
8599 * of swizzling perf_event::ctx.
8601 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8602 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8604 perf_remove_from_context(event
, 0);
8605 unaccount_event_cpu(event
, src_cpu
);
8607 list_add(&event
->migrate_entry
, &events
);
8611 * Wait for the events to quiesce before re-instating them.
8616 * Re-instate events in 2 passes.
8618 * Skip over group leaders and only install siblings on this first
8619 * pass, siblings will not get enabled without a leader, however a
8620 * leader will enable its siblings, even if those are still on the old
8623 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8624 if (event
->group_leader
== event
)
8627 list_del(&event
->migrate_entry
);
8628 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8629 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8630 account_event_cpu(event
, dst_cpu
);
8631 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8636 * Once all the siblings are setup properly, install the group leaders
8639 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8640 list_del(&event
->migrate_entry
);
8641 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8642 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8643 account_event_cpu(event
, dst_cpu
);
8644 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8647 mutex_unlock(&dst_ctx
->mutex
);
8648 mutex_unlock(&src_ctx
->mutex
);
8650 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8652 static void sync_child_event(struct perf_event
*child_event
,
8653 struct task_struct
*child
)
8655 struct perf_event
*parent_event
= child_event
->parent
;
8658 if (child_event
->attr
.inherit_stat
)
8659 perf_event_read_event(child_event
, child
);
8661 child_val
= perf_event_count(child_event
);
8664 * Add back the child's count to the parent's count:
8666 atomic64_add(child_val
, &parent_event
->child_count
);
8667 atomic64_add(child_event
->total_time_enabled
,
8668 &parent_event
->child_total_time_enabled
);
8669 atomic64_add(child_event
->total_time_running
,
8670 &parent_event
->child_total_time_running
);
8674 perf_event_exit_event(struct perf_event
*child_event
,
8675 struct perf_event_context
*child_ctx
,
8676 struct task_struct
*child
)
8678 struct perf_event
*parent_event
= child_event
->parent
;
8681 * Do not destroy the 'original' grouping; because of the context
8682 * switch optimization the original events could've ended up in a
8683 * random child task.
8685 * If we were to destroy the original group, all group related
8686 * operations would cease to function properly after this random
8689 * Do destroy all inherited groups, we don't care about those
8690 * and being thorough is better.
8692 raw_spin_lock_irq(&child_ctx
->lock
);
8693 WARN_ON_ONCE(child_ctx
->is_active
);
8696 perf_group_detach(child_event
);
8697 list_del_event(child_event
, child_ctx
);
8698 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* see perf_event_release_kernel() */
8699 raw_spin_unlock_irq(&child_ctx
->lock
);
8702 * Parent events are governed by their filedesc, retain them.
8704 if (!parent_event
) {
8705 perf_event_wakeup(child_event
);
8709 * Child events can be cleaned up.
8712 sync_child_event(child_event
, child
);
8715 * Remove this event from the parent's list
8717 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8718 mutex_lock(&parent_event
->child_mutex
);
8719 list_del_init(&child_event
->child_list
);
8720 mutex_unlock(&parent_event
->child_mutex
);
8723 * Kick perf_poll() for is_event_hup().
8725 perf_event_wakeup(parent_event
);
8726 free_event(child_event
);
8727 put_event(parent_event
);
8730 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8732 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8733 struct perf_event
*child_event
, *next
;
8735 WARN_ON_ONCE(child
!= current
);
8737 child_ctx
= perf_pin_task_context(child
, ctxn
);
8742 * In order to reduce the amount of tricky in ctx tear-down, we hold
8743 * ctx::mutex over the entire thing. This serializes against almost
8744 * everything that wants to access the ctx.
8746 * The exception is sys_perf_event_open() /
8747 * perf_event_create_kernel_count() which does find_get_context()
8748 * without ctx::mutex (it cannot because of the move_group double mutex
8749 * lock thing). See the comments in perf_install_in_context().
8751 mutex_lock(&child_ctx
->mutex
);
8754 * In a single ctx::lock section, de-schedule the events and detach the
8755 * context from the task such that we cannot ever get it scheduled back
8758 raw_spin_lock_irq(&child_ctx
->lock
);
8759 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
);
8762 * Now that the context is inactive, destroy the task <-> ctx relation
8763 * and mark the context dead.
8765 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
8766 put_ctx(child_ctx
); /* cannot be last */
8767 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
8768 put_task_struct(current
); /* cannot be last */
8770 clone_ctx
= unclone_ctx(child_ctx
);
8771 raw_spin_unlock_irq(&child_ctx
->lock
);
8777 * Report the task dead after unscheduling the events so that we
8778 * won't get any samples after PERF_RECORD_EXIT. We can however still
8779 * get a few PERF_RECORD_READ events.
8781 perf_event_task(child
, child_ctx
, 0);
8783 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8784 perf_event_exit_event(child_event
, child_ctx
, child
);
8786 mutex_unlock(&child_ctx
->mutex
);
8792 * When a child task exits, feed back event values to parent events.
8794 void perf_event_exit_task(struct task_struct
*child
)
8796 struct perf_event
*event
, *tmp
;
8799 mutex_lock(&child
->perf_event_mutex
);
8800 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8802 list_del_init(&event
->owner_entry
);
8805 * Ensure the list deletion is visible before we clear
8806 * the owner, closes a race against perf_release() where
8807 * we need to serialize on the owner->perf_event_mutex.
8809 smp_store_release(&event
->owner
, NULL
);
8811 mutex_unlock(&child
->perf_event_mutex
);
8813 for_each_task_context_nr(ctxn
)
8814 perf_event_exit_task_context(child
, ctxn
);
8817 * The perf_event_exit_task_context calls perf_event_task
8818 * with child's task_ctx, which generates EXIT events for
8819 * child contexts and sets child->perf_event_ctxp[] to NULL.
8820 * At this point we need to send EXIT events to cpu contexts.
8822 perf_event_task(child
, NULL
, 0);
8825 static void perf_free_event(struct perf_event
*event
,
8826 struct perf_event_context
*ctx
)
8828 struct perf_event
*parent
= event
->parent
;
8830 if (WARN_ON_ONCE(!parent
))
8833 mutex_lock(&parent
->child_mutex
);
8834 list_del_init(&event
->child_list
);
8835 mutex_unlock(&parent
->child_mutex
);
8839 raw_spin_lock_irq(&ctx
->lock
);
8840 perf_group_detach(event
);
8841 list_del_event(event
, ctx
);
8842 raw_spin_unlock_irq(&ctx
->lock
);
8847 * Free an unexposed, unused context as created by inheritance by
8848 * perf_event_init_task below, used by fork() in case of fail.
8850 * Not all locks are strictly required, but take them anyway to be nice and
8851 * help out with the lockdep assertions.
8853 void perf_event_free_task(struct task_struct
*task
)
8855 struct perf_event_context
*ctx
;
8856 struct perf_event
*event
, *tmp
;
8859 for_each_task_context_nr(ctxn
) {
8860 ctx
= task
->perf_event_ctxp
[ctxn
];
8864 mutex_lock(&ctx
->mutex
);
8866 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8868 perf_free_event(event
, ctx
);
8870 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8872 perf_free_event(event
, ctx
);
8874 if (!list_empty(&ctx
->pinned_groups
) ||
8875 !list_empty(&ctx
->flexible_groups
))
8878 mutex_unlock(&ctx
->mutex
);
8884 void perf_event_delayed_put(struct task_struct
*task
)
8888 for_each_task_context_nr(ctxn
)
8889 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8892 struct file
*perf_event_get(unsigned int fd
)
8896 file
= fget_raw(fd
);
8898 return ERR_PTR(-EBADF
);
8900 if (file
->f_op
!= &perf_fops
) {
8902 return ERR_PTR(-EBADF
);
8908 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
8911 return ERR_PTR(-EINVAL
);
8913 return &event
->attr
;
8917 * inherit a event from parent task to child task:
8919 static struct perf_event
*
8920 inherit_event(struct perf_event
*parent_event
,
8921 struct task_struct
*parent
,
8922 struct perf_event_context
*parent_ctx
,
8923 struct task_struct
*child
,
8924 struct perf_event
*group_leader
,
8925 struct perf_event_context
*child_ctx
)
8927 enum perf_event_active_state parent_state
= parent_event
->state
;
8928 struct perf_event
*child_event
;
8929 unsigned long flags
;
8932 * Instead of creating recursive hierarchies of events,
8933 * we link inherited events back to the original parent,
8934 * which has a filp for sure, which we use as the reference
8937 if (parent_event
->parent
)
8938 parent_event
= parent_event
->parent
;
8940 child_event
= perf_event_alloc(&parent_event
->attr
,
8943 group_leader
, parent_event
,
8945 if (IS_ERR(child_event
))
8949 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
8950 * must be under the same lock in order to serialize against
8951 * perf_event_release_kernel(), such that either we must observe
8952 * is_orphaned_event() or they will observe us on the child_list.
8954 mutex_lock(&parent_event
->child_mutex
);
8955 if (is_orphaned_event(parent_event
) ||
8956 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
8957 mutex_unlock(&parent_event
->child_mutex
);
8958 free_event(child_event
);
8965 * Make the child state follow the state of the parent event,
8966 * not its attr.disabled bit. We hold the parent's mutex,
8967 * so we won't race with perf_event_{en, dis}able_family.
8969 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
8970 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
8972 child_event
->state
= PERF_EVENT_STATE_OFF
;
8974 if (parent_event
->attr
.freq
) {
8975 u64 sample_period
= parent_event
->hw
.sample_period
;
8976 struct hw_perf_event
*hwc
= &child_event
->hw
;
8978 hwc
->sample_period
= sample_period
;
8979 hwc
->last_period
= sample_period
;
8981 local64_set(&hwc
->period_left
, sample_period
);
8984 child_event
->ctx
= child_ctx
;
8985 child_event
->overflow_handler
= parent_event
->overflow_handler
;
8986 child_event
->overflow_handler_context
8987 = parent_event
->overflow_handler_context
;
8990 * Precalculate sample_data sizes
8992 perf_event__header_size(child_event
);
8993 perf_event__id_header_size(child_event
);
8996 * Link it up in the child's context:
8998 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
8999 add_event_to_ctx(child_event
, child_ctx
);
9000 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
9003 * Link this into the parent event's child list
9005 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
9006 mutex_unlock(&parent_event
->child_mutex
);
9011 static int inherit_group(struct perf_event
*parent_event
,
9012 struct task_struct
*parent
,
9013 struct perf_event_context
*parent_ctx
,
9014 struct task_struct
*child
,
9015 struct perf_event_context
*child_ctx
)
9017 struct perf_event
*leader
;
9018 struct perf_event
*sub
;
9019 struct perf_event
*child_ctr
;
9021 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9022 child
, NULL
, child_ctx
);
9024 return PTR_ERR(leader
);
9025 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9026 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9027 child
, leader
, child_ctx
);
9028 if (IS_ERR(child_ctr
))
9029 return PTR_ERR(child_ctr
);
9035 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9036 struct perf_event_context
*parent_ctx
,
9037 struct task_struct
*child
, int ctxn
,
9041 struct perf_event_context
*child_ctx
;
9043 if (!event
->attr
.inherit
) {
9048 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9051 * This is executed from the parent task context, so
9052 * inherit events that have been marked for cloning.
9053 * First allocate and initialize a context for the
9057 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9061 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9064 ret
= inherit_group(event
, parent
, parent_ctx
,
9074 * Initialize the perf_event context in task_struct
9076 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9078 struct perf_event_context
*child_ctx
, *parent_ctx
;
9079 struct perf_event_context
*cloned_ctx
;
9080 struct perf_event
*event
;
9081 struct task_struct
*parent
= current
;
9082 int inherited_all
= 1;
9083 unsigned long flags
;
9086 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9090 * If the parent's context is a clone, pin it so it won't get
9093 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9098 * No need to check if parent_ctx != NULL here; since we saw
9099 * it non-NULL earlier, the only reason for it to become NULL
9100 * is if we exit, and since we're currently in the middle of
9101 * a fork we can't be exiting at the same time.
9105 * Lock the parent list. No need to lock the child - not PID
9106 * hashed yet and not running, so nobody can access it.
9108 mutex_lock(&parent_ctx
->mutex
);
9111 * We dont have to disable NMIs - we are only looking at
9112 * the list, not manipulating it:
9114 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9115 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9116 child
, ctxn
, &inherited_all
);
9122 * We can't hold ctx->lock when iterating the ->flexible_group list due
9123 * to allocations, but we need to prevent rotation because
9124 * rotate_ctx() will change the list from interrupt context.
9126 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9127 parent_ctx
->rotate_disable
= 1;
9128 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9130 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9131 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9132 child
, ctxn
, &inherited_all
);
9137 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9138 parent_ctx
->rotate_disable
= 0;
9140 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9142 if (child_ctx
&& inherited_all
) {
9144 * Mark the child context as a clone of the parent
9145 * context, or of whatever the parent is a clone of.
9147 * Note that if the parent is a clone, the holding of
9148 * parent_ctx->lock avoids it from being uncloned.
9150 cloned_ctx
= parent_ctx
->parent_ctx
;
9152 child_ctx
->parent_ctx
= cloned_ctx
;
9153 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9155 child_ctx
->parent_ctx
= parent_ctx
;
9156 child_ctx
->parent_gen
= parent_ctx
->generation
;
9158 get_ctx(child_ctx
->parent_ctx
);
9161 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9162 mutex_unlock(&parent_ctx
->mutex
);
9164 perf_unpin_context(parent_ctx
);
9165 put_ctx(parent_ctx
);
9171 * Initialize the perf_event context in task_struct
9173 int perf_event_init_task(struct task_struct
*child
)
9177 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9178 mutex_init(&child
->perf_event_mutex
);
9179 INIT_LIST_HEAD(&child
->perf_event_list
);
9181 for_each_task_context_nr(ctxn
) {
9182 ret
= perf_event_init_context(child
, ctxn
);
9184 perf_event_free_task(child
);
9192 static void __init
perf_event_init_all_cpus(void)
9194 struct swevent_htable
*swhash
;
9197 for_each_possible_cpu(cpu
) {
9198 swhash
= &per_cpu(swevent_htable
, cpu
);
9199 mutex_init(&swhash
->hlist_mutex
);
9200 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9204 static void perf_event_init_cpu(int cpu
)
9206 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9208 mutex_lock(&swhash
->hlist_mutex
);
9209 if (swhash
->hlist_refcount
> 0) {
9210 struct swevent_hlist
*hlist
;
9212 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9214 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9216 mutex_unlock(&swhash
->hlist_mutex
);
9219 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9220 static void __perf_event_exit_context(void *__info
)
9222 struct perf_event_context
*ctx
= __info
;
9223 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
9224 struct perf_event
*event
;
9226 raw_spin_lock(&ctx
->lock
);
9227 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
9228 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
9229 raw_spin_unlock(&ctx
->lock
);
9232 static void perf_event_exit_cpu_context(int cpu
)
9234 struct perf_event_context
*ctx
;
9238 idx
= srcu_read_lock(&pmus_srcu
);
9239 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9240 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9242 mutex_lock(&ctx
->mutex
);
9243 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9244 mutex_unlock(&ctx
->mutex
);
9246 srcu_read_unlock(&pmus_srcu
, idx
);
9249 static void perf_event_exit_cpu(int cpu
)
9251 perf_event_exit_cpu_context(cpu
);
9254 static inline void perf_event_exit_cpu(int cpu
) { }
9258 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9262 for_each_online_cpu(cpu
)
9263 perf_event_exit_cpu(cpu
);
9269 * Run the perf reboot notifier at the very last possible moment so that
9270 * the generic watchdog code runs as long as possible.
9272 static struct notifier_block perf_reboot_notifier
= {
9273 .notifier_call
= perf_reboot
,
9274 .priority
= INT_MIN
,
9278 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9280 unsigned int cpu
= (long)hcpu
;
9282 switch (action
& ~CPU_TASKS_FROZEN
) {
9284 case CPU_UP_PREPARE
:
9285 case CPU_DOWN_FAILED
:
9286 perf_event_init_cpu(cpu
);
9289 case CPU_UP_CANCELED
:
9290 case CPU_DOWN_PREPARE
:
9291 perf_event_exit_cpu(cpu
);
9300 void __init
perf_event_init(void)
9306 perf_event_init_all_cpus();
9307 init_srcu_struct(&pmus_srcu
);
9308 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9309 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9310 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9312 perf_cpu_notifier(perf_cpu_notify
);
9313 register_reboot_notifier(&perf_reboot_notifier
);
9315 ret
= init_hw_breakpoint();
9316 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9318 /* do not patch jump label more than once per second */
9319 jump_label_rate_limit(&perf_sched_events
, HZ
);
9322 * Build time assertion that we keep the data_head at the intended
9323 * location. IOW, validation we got the __reserved[] size right.
9325 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9329 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9332 struct perf_pmu_events_attr
*pmu_attr
=
9333 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9335 if (pmu_attr
->event_str
)
9336 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9341 static int __init
perf_event_sysfs_init(void)
9346 mutex_lock(&pmus_lock
);
9348 ret
= bus_register(&pmu_bus
);
9352 list_for_each_entry(pmu
, &pmus
, entry
) {
9353 if (!pmu
->name
|| pmu
->type
< 0)
9356 ret
= pmu_dev_alloc(pmu
);
9357 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9359 pmu_bus_running
= 1;
9363 mutex_unlock(&pmus_lock
);
9367 device_initcall(perf_event_sysfs_init
);
9369 #ifdef CONFIG_CGROUP_PERF
9370 static struct cgroup_subsys_state
*
9371 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9373 struct perf_cgroup
*jc
;
9375 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9377 return ERR_PTR(-ENOMEM
);
9379 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9382 return ERR_PTR(-ENOMEM
);
9388 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9390 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9392 free_percpu(jc
->info
);
9396 static int __perf_cgroup_move(void *info
)
9398 struct task_struct
*task
= info
;
9400 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9405 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
9407 struct task_struct
*task
;
9408 struct cgroup_subsys_state
*css
;
9410 cgroup_taskset_for_each(task
, css
, tset
)
9411 task_function_call(task
, __perf_cgroup_move
, task
);
9414 struct cgroup_subsys perf_event_cgrp_subsys
= {
9415 .css_alloc
= perf_cgroup_css_alloc
,
9416 .css_free
= perf_cgroup_css_free
,
9417 .attach
= perf_cgroup_attach
,
9419 #endif /* CONFIG_CGROUP_PERF */