2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
50 #include <asm/irq_regs.h>
52 static struct workqueue_struct
*perf_wq
;
54 typedef int (*remote_function_f
)(void *);
56 struct remote_function_call
{
57 struct task_struct
*p
;
58 remote_function_f func
;
63 static void remote_function(void *data
)
65 struct remote_function_call
*tfc
= data
;
66 struct task_struct
*p
= tfc
->p
;
70 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
74 tfc
->ret
= tfc
->func(tfc
->info
);
78 * task_function_call - call a function on the cpu on which a task runs
79 * @p: the task to evaluate
80 * @func: the function to be called
81 * @info: the function call argument
83 * Calls the function @func when the task is currently running. This might
84 * be on the current CPU, which just calls the function directly
86 * returns: @func return value, or
87 * -ESRCH - when the process isn't running
88 * -EAGAIN - when the process moved away
91 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
93 struct remote_function_call data
= {
97 .ret
= -ESRCH
, /* No such (running) process */
101 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
107 * cpu_function_call - call a function on the cpu
108 * @func: the function to be called
109 * @info: the function call argument
111 * Calls the function @func on the remote cpu.
113 * returns: @func return value or -ENXIO when the cpu is offline
115 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
117 struct remote_function_call data
= {
121 .ret
= -ENXIO
, /* No such CPU */
124 smp_call_function_single(cpu
, remote_function
, &data
, 1);
129 static inline struct perf_cpu_context
*
130 __get_cpu_context(struct perf_event_context
*ctx
)
132 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
135 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
136 struct perf_event_context
*ctx
)
138 raw_spin_lock(&cpuctx
->ctx
.lock
);
140 raw_spin_lock(&ctx
->lock
);
143 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
144 struct perf_event_context
*ctx
)
147 raw_spin_unlock(&ctx
->lock
);
148 raw_spin_unlock(&cpuctx
->ctx
.lock
);
151 #define TASK_TOMBSTONE ((void *)-1L)
153 static bool is_kernel_event(struct perf_event
*event
)
155 return event
->owner
== TASK_TOMBSTONE
;
159 * On task ctx scheduling...
161 * When !ctx->nr_events a task context will not be scheduled. This means
162 * we can disable the scheduler hooks (for performance) without leaving
163 * pending task ctx state.
165 * This however results in two special cases:
167 * - removing the last event from a task ctx; this is relatively straight
168 * forward and is done in __perf_remove_from_context.
170 * - adding the first event to a task ctx; this is tricky because we cannot
171 * rely on ctx->is_active and therefore cannot use event_function_call().
172 * See perf_install_in_context().
174 * This is because we need a ctx->lock serialized variable (ctx->is_active)
175 * to reliably determine if a particular task/context is scheduled in. The
176 * task_curr() use in task_function_call() is racy in that a remote context
177 * switch is not a single atomic operation.
179 * As is, the situation is 'safe' because we set rq->curr before we do the
180 * actual context switch. This means that task_curr() will fail early, but
181 * we'll continue spinning on ctx->is_active until we've passed
182 * perf_event_task_sched_out().
184 * Without this ctx->lock serialized variable we could have race where we find
185 * the task (and hence the context) would not be active while in fact they are.
187 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
190 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
191 struct perf_event_context
*, void *);
193 struct event_function_struct
{
194 struct perf_event
*event
;
199 static int event_function(void *info
)
201 struct event_function_struct
*efs
= info
;
202 struct perf_event
*event
= efs
->event
;
203 struct perf_event_context
*ctx
= event
->ctx
;
204 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
205 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
208 WARN_ON_ONCE(!irqs_disabled());
210 perf_ctx_lock(cpuctx
, task_ctx
);
212 * Since we do the IPI call without holding ctx->lock things can have
213 * changed, double check we hit the task we set out to hit.
216 if (ctx
->task
!= current
) {
222 * We only use event_function_call() on established contexts,
223 * and event_function() is only ever called when active (or
224 * rather, we'll have bailed in task_function_call() or the
225 * above ctx->task != current test), therefore we must have
226 * ctx->is_active here.
228 WARN_ON_ONCE(!ctx
->is_active
);
230 * And since we have ctx->is_active, cpuctx->task_ctx must
233 WARN_ON_ONCE(task_ctx
!= ctx
);
235 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
238 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
240 perf_ctx_unlock(cpuctx
, task_ctx
);
245 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
247 struct event_function_struct efs
= {
253 int ret
= event_function(&efs
);
257 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
259 struct perf_event_context
*ctx
= event
->ctx
;
260 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
261 struct event_function_struct efs
= {
267 if (!event
->parent
) {
269 * If this is a !child event, we must hold ctx::mutex to
270 * stabilize the the event->ctx relation. See
271 * perf_event_ctx_lock().
273 lockdep_assert_held(&ctx
->mutex
);
277 cpu_function_call(event
->cpu
, event_function
, &efs
);
282 if (task
== TASK_TOMBSTONE
)
285 if (!task_function_call(task
, event_function
, &efs
))
288 raw_spin_lock_irq(&ctx
->lock
);
290 * Reload the task pointer, it might have been changed by
291 * a concurrent perf_event_context_sched_out().
294 if (task
!= TASK_TOMBSTONE
) {
295 if (ctx
->is_active
) {
296 raw_spin_unlock_irq(&ctx
->lock
);
299 func(event
, NULL
, ctx
, data
);
301 raw_spin_unlock_irq(&ctx
->lock
);
304 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
305 PERF_FLAG_FD_OUTPUT |\
306 PERF_FLAG_PID_CGROUP |\
307 PERF_FLAG_FD_CLOEXEC)
310 * branch priv levels that need permission checks
312 #define PERF_SAMPLE_BRANCH_PERM_PLM \
313 (PERF_SAMPLE_BRANCH_KERNEL |\
314 PERF_SAMPLE_BRANCH_HV)
317 EVENT_FLEXIBLE
= 0x1,
319 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
323 * perf_sched_events : >0 events exist
324 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
326 struct static_key_deferred perf_sched_events __read_mostly
;
327 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
328 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
330 static atomic_t nr_mmap_events __read_mostly
;
331 static atomic_t nr_comm_events __read_mostly
;
332 static atomic_t nr_task_events __read_mostly
;
333 static atomic_t nr_freq_events __read_mostly
;
334 static atomic_t nr_switch_events __read_mostly
;
336 static LIST_HEAD(pmus
);
337 static DEFINE_MUTEX(pmus_lock
);
338 static struct srcu_struct pmus_srcu
;
341 * perf event paranoia level:
342 * -1 - not paranoid at all
343 * 0 - disallow raw tracepoint access for unpriv
344 * 1 - disallow cpu events for unpriv
345 * 2 - disallow kernel profiling for unpriv
347 int sysctl_perf_event_paranoid __read_mostly
= 1;
349 /* Minimum for 512 kiB + 1 user control page */
350 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
353 * max perf event sample rate
355 #define DEFAULT_MAX_SAMPLE_RATE 100000
356 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
357 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
359 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
361 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
362 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
364 static int perf_sample_allowed_ns __read_mostly
=
365 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
367 static void update_perf_cpu_limits(void)
369 u64 tmp
= perf_sample_period_ns
;
371 tmp
*= sysctl_perf_cpu_time_max_percent
;
373 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
376 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
378 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
379 void __user
*buffer
, size_t *lenp
,
382 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
387 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
388 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
389 update_perf_cpu_limits();
394 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
396 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
397 void __user
*buffer
, size_t *lenp
,
400 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
405 update_perf_cpu_limits();
411 * perf samples are done in some very critical code paths (NMIs).
412 * If they take too much CPU time, the system can lock up and not
413 * get any real work done. This will drop the sample rate when
414 * we detect that events are taking too long.
416 #define NR_ACCUMULATED_SAMPLES 128
417 static DEFINE_PER_CPU(u64
, running_sample_length
);
419 static void perf_duration_warn(struct irq_work
*w
)
421 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
422 u64 avg_local_sample_len
;
423 u64 local_samples_len
;
425 local_samples_len
= __this_cpu_read(running_sample_length
);
426 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
428 printk_ratelimited(KERN_WARNING
429 "perf interrupt took too long (%lld > %lld), lowering "
430 "kernel.perf_event_max_sample_rate to %d\n",
431 avg_local_sample_len
, allowed_ns
>> 1,
432 sysctl_perf_event_sample_rate
);
435 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
437 void perf_sample_event_took(u64 sample_len_ns
)
439 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
440 u64 avg_local_sample_len
;
441 u64 local_samples_len
;
446 /* decay the counter by 1 average sample */
447 local_samples_len
= __this_cpu_read(running_sample_length
);
448 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
449 local_samples_len
+= sample_len_ns
;
450 __this_cpu_write(running_sample_length
, local_samples_len
);
453 * note: this will be biased artifically low until we have
454 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
455 * from having to maintain a count.
457 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
459 if (avg_local_sample_len
<= allowed_ns
)
462 if (max_samples_per_tick
<= 1)
465 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
466 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
467 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
469 update_perf_cpu_limits();
471 if (!irq_work_queue(&perf_duration_work
)) {
472 early_printk("perf interrupt took too long (%lld > %lld), lowering "
473 "kernel.perf_event_max_sample_rate to %d\n",
474 avg_local_sample_len
, allowed_ns
>> 1,
475 sysctl_perf_event_sample_rate
);
479 static atomic64_t perf_event_id
;
481 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
482 enum event_type_t event_type
);
484 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
485 enum event_type_t event_type
,
486 struct task_struct
*task
);
488 static void update_context_time(struct perf_event_context
*ctx
);
489 static u64
perf_event_time(struct perf_event
*event
);
491 void __weak
perf_event_print_debug(void) { }
493 extern __weak
const char *perf_pmu_name(void)
498 static inline u64
perf_clock(void)
500 return local_clock();
503 static inline u64
perf_event_clock(struct perf_event
*event
)
505 return event
->clock();
508 #ifdef CONFIG_CGROUP_PERF
511 perf_cgroup_match(struct perf_event
*event
)
513 struct perf_event_context
*ctx
= event
->ctx
;
514 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
516 /* @event doesn't care about cgroup */
520 /* wants specific cgroup scope but @cpuctx isn't associated with any */
525 * Cgroup scoping is recursive. An event enabled for a cgroup is
526 * also enabled for all its descendant cgroups. If @cpuctx's
527 * cgroup is a descendant of @event's (the test covers identity
528 * case), it's a match.
530 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
531 event
->cgrp
->css
.cgroup
);
534 static inline void perf_detach_cgroup(struct perf_event
*event
)
536 css_put(&event
->cgrp
->css
);
540 static inline int is_cgroup_event(struct perf_event
*event
)
542 return event
->cgrp
!= NULL
;
545 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
547 struct perf_cgroup_info
*t
;
549 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
553 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
555 struct perf_cgroup_info
*info
;
560 info
= this_cpu_ptr(cgrp
->info
);
562 info
->time
+= now
- info
->timestamp
;
563 info
->timestamp
= now
;
566 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
568 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
570 __update_cgrp_time(cgrp_out
);
573 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
575 struct perf_cgroup
*cgrp
;
578 * ensure we access cgroup data only when needed and
579 * when we know the cgroup is pinned (css_get)
581 if (!is_cgroup_event(event
))
584 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
586 * Do not update time when cgroup is not active
588 if (cgrp
== event
->cgrp
)
589 __update_cgrp_time(event
->cgrp
);
593 perf_cgroup_set_timestamp(struct task_struct
*task
,
594 struct perf_event_context
*ctx
)
596 struct perf_cgroup
*cgrp
;
597 struct perf_cgroup_info
*info
;
600 * ctx->lock held by caller
601 * ensure we do not access cgroup data
602 * unless we have the cgroup pinned (css_get)
604 if (!task
|| !ctx
->nr_cgroups
)
607 cgrp
= perf_cgroup_from_task(task
, ctx
);
608 info
= this_cpu_ptr(cgrp
->info
);
609 info
->timestamp
= ctx
->timestamp
;
612 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
613 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
616 * reschedule events based on the cgroup constraint of task.
618 * mode SWOUT : schedule out everything
619 * mode SWIN : schedule in based on cgroup for next
621 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
623 struct perf_cpu_context
*cpuctx
;
628 * disable interrupts to avoid geting nr_cgroup
629 * changes via __perf_event_disable(). Also
632 local_irq_save(flags
);
635 * we reschedule only in the presence of cgroup
636 * constrained events.
639 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
640 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
641 if (cpuctx
->unique_pmu
!= pmu
)
642 continue; /* ensure we process each cpuctx once */
645 * perf_cgroup_events says at least one
646 * context on this CPU has cgroup events.
648 * ctx->nr_cgroups reports the number of cgroup
649 * events for a context.
651 if (cpuctx
->ctx
.nr_cgroups
> 0) {
652 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
653 perf_pmu_disable(cpuctx
->ctx
.pmu
);
655 if (mode
& PERF_CGROUP_SWOUT
) {
656 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
658 * must not be done before ctxswout due
659 * to event_filter_match() in event_sched_out()
664 if (mode
& PERF_CGROUP_SWIN
) {
665 WARN_ON_ONCE(cpuctx
->cgrp
);
667 * set cgrp before ctxsw in to allow
668 * event_filter_match() to not have to pass
670 * we pass the cpuctx->ctx to perf_cgroup_from_task()
671 * because cgorup events are only per-cpu
673 cpuctx
->cgrp
= perf_cgroup_from_task(task
, &cpuctx
->ctx
);
674 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
676 perf_pmu_enable(cpuctx
->ctx
.pmu
);
677 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
681 local_irq_restore(flags
);
684 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
685 struct task_struct
*next
)
687 struct perf_cgroup
*cgrp1
;
688 struct perf_cgroup
*cgrp2
= NULL
;
692 * we come here when we know perf_cgroup_events > 0
693 * we do not need to pass the ctx here because we know
694 * we are holding the rcu lock
696 cgrp1
= perf_cgroup_from_task(task
, NULL
);
697 cgrp2
= perf_cgroup_from_task(next
, NULL
);
700 * only schedule out current cgroup events if we know
701 * that we are switching to a different cgroup. Otherwise,
702 * do no touch the cgroup events.
705 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
710 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
711 struct task_struct
*task
)
713 struct perf_cgroup
*cgrp1
;
714 struct perf_cgroup
*cgrp2
= NULL
;
718 * we come here when we know perf_cgroup_events > 0
719 * we do not need to pass the ctx here because we know
720 * we are holding the rcu lock
722 cgrp1
= perf_cgroup_from_task(task
, NULL
);
723 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
726 * only need to schedule in cgroup events if we are changing
727 * cgroup during ctxsw. Cgroup events were not scheduled
728 * out of ctxsw out if that was not the case.
731 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
736 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
737 struct perf_event_attr
*attr
,
738 struct perf_event
*group_leader
)
740 struct perf_cgroup
*cgrp
;
741 struct cgroup_subsys_state
*css
;
742 struct fd f
= fdget(fd
);
748 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
749 &perf_event_cgrp_subsys
);
755 cgrp
= container_of(css
, struct perf_cgroup
, css
);
759 * all events in a group must monitor
760 * the same cgroup because a task belongs
761 * to only one perf cgroup at a time
763 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
764 perf_detach_cgroup(event
);
773 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
775 struct perf_cgroup_info
*t
;
776 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
777 event
->shadow_ctx_time
= now
- t
->timestamp
;
781 perf_cgroup_defer_enabled(struct perf_event
*event
)
784 * when the current task's perf cgroup does not match
785 * the event's, we need to remember to call the
786 * perf_mark_enable() function the first time a task with
787 * a matching perf cgroup is scheduled in.
789 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
790 event
->cgrp_defer_enabled
= 1;
794 perf_cgroup_mark_enabled(struct perf_event
*event
,
795 struct perf_event_context
*ctx
)
797 struct perf_event
*sub
;
798 u64 tstamp
= perf_event_time(event
);
800 if (!event
->cgrp_defer_enabled
)
803 event
->cgrp_defer_enabled
= 0;
805 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
806 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
807 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
808 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
809 sub
->cgrp_defer_enabled
= 0;
813 #else /* !CONFIG_CGROUP_PERF */
816 perf_cgroup_match(struct perf_event
*event
)
821 static inline void perf_detach_cgroup(struct perf_event
*event
)
824 static inline int is_cgroup_event(struct perf_event
*event
)
829 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
834 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
838 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
842 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
843 struct task_struct
*next
)
847 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
848 struct task_struct
*task
)
852 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
853 struct perf_event_attr
*attr
,
854 struct perf_event
*group_leader
)
860 perf_cgroup_set_timestamp(struct task_struct
*task
,
861 struct perf_event_context
*ctx
)
866 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
871 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
875 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
881 perf_cgroup_defer_enabled(struct perf_event
*event
)
886 perf_cgroup_mark_enabled(struct perf_event
*event
,
887 struct perf_event_context
*ctx
)
893 * set default to be dependent on timer tick just
896 #define PERF_CPU_HRTIMER (1000 / HZ)
898 * function must be called with interrupts disbled
900 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
902 struct perf_cpu_context
*cpuctx
;
905 WARN_ON(!irqs_disabled());
907 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
908 rotations
= perf_rotate_context(cpuctx
);
910 raw_spin_lock(&cpuctx
->hrtimer_lock
);
912 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
914 cpuctx
->hrtimer_active
= 0;
915 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
917 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
920 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
922 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
923 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
926 /* no multiplexing needed for SW PMU */
927 if (pmu
->task_ctx_nr
== perf_sw_context
)
931 * check default is sane, if not set then force to
932 * default interval (1/tick)
934 interval
= pmu
->hrtimer_interval_ms
;
936 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
938 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
940 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
941 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
942 timer
->function
= perf_mux_hrtimer_handler
;
945 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
947 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
948 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
952 if (pmu
->task_ctx_nr
== perf_sw_context
)
955 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
956 if (!cpuctx
->hrtimer_active
) {
957 cpuctx
->hrtimer_active
= 1;
958 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
959 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
961 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
966 void perf_pmu_disable(struct pmu
*pmu
)
968 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
970 pmu
->pmu_disable(pmu
);
973 void perf_pmu_enable(struct pmu
*pmu
)
975 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
977 pmu
->pmu_enable(pmu
);
980 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
983 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
984 * perf_event_task_tick() are fully serialized because they're strictly cpu
985 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
986 * disabled, while perf_event_task_tick is called from IRQ context.
988 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
990 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
992 WARN_ON(!irqs_disabled());
994 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
996 list_add(&ctx
->active_ctx_list
, head
);
999 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1001 WARN_ON(!irqs_disabled());
1003 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1005 list_del_init(&ctx
->active_ctx_list
);
1008 static void get_ctx(struct perf_event_context
*ctx
)
1010 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1013 static void free_ctx(struct rcu_head
*head
)
1015 struct perf_event_context
*ctx
;
1017 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1018 kfree(ctx
->task_ctx_data
);
1022 static void put_ctx(struct perf_event_context
*ctx
)
1024 if (atomic_dec_and_test(&ctx
->refcount
)) {
1025 if (ctx
->parent_ctx
)
1026 put_ctx(ctx
->parent_ctx
);
1027 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1028 put_task_struct(ctx
->task
);
1029 call_rcu(&ctx
->rcu_head
, free_ctx
);
1034 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1035 * perf_pmu_migrate_context() we need some magic.
1037 * Those places that change perf_event::ctx will hold both
1038 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1040 * Lock ordering is by mutex address. There are two other sites where
1041 * perf_event_context::mutex nests and those are:
1043 * - perf_event_exit_task_context() [ child , 0 ]
1044 * __perf_event_exit_task()
1045 * sync_child_event()
1046 * put_event() [ parent, 1 ]
1048 * - perf_event_init_context() [ parent, 0 ]
1049 * inherit_task_group()
1052 * perf_event_alloc()
1054 * perf_try_init_event() [ child , 1 ]
1056 * While it appears there is an obvious deadlock here -- the parent and child
1057 * nesting levels are inverted between the two. This is in fact safe because
1058 * life-time rules separate them. That is an exiting task cannot fork, and a
1059 * spawning task cannot (yet) exit.
1061 * But remember that that these are parent<->child context relations, and
1062 * migration does not affect children, therefore these two orderings should not
1065 * The change in perf_event::ctx does not affect children (as claimed above)
1066 * because the sys_perf_event_open() case will install a new event and break
1067 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1068 * concerned with cpuctx and that doesn't have children.
1070 * The places that change perf_event::ctx will issue:
1072 * perf_remove_from_context();
1073 * synchronize_rcu();
1074 * perf_install_in_context();
1076 * to affect the change. The remove_from_context() + synchronize_rcu() should
1077 * quiesce the event, after which we can install it in the new location. This
1078 * means that only external vectors (perf_fops, prctl) can perturb the event
1079 * while in transit. Therefore all such accessors should also acquire
1080 * perf_event_context::mutex to serialize against this.
1082 * However; because event->ctx can change while we're waiting to acquire
1083 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1087 * task_struct::perf_event_mutex
1088 * perf_event_context::mutex
1089 * perf_event_context::lock
1090 * perf_event::child_mutex;
1091 * perf_event::mmap_mutex
1094 static struct perf_event_context
*
1095 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1097 struct perf_event_context
*ctx
;
1101 ctx
= ACCESS_ONCE(event
->ctx
);
1102 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1108 mutex_lock_nested(&ctx
->mutex
, nesting
);
1109 if (event
->ctx
!= ctx
) {
1110 mutex_unlock(&ctx
->mutex
);
1118 static inline struct perf_event_context
*
1119 perf_event_ctx_lock(struct perf_event
*event
)
1121 return perf_event_ctx_lock_nested(event
, 0);
1124 static void perf_event_ctx_unlock(struct perf_event
*event
,
1125 struct perf_event_context
*ctx
)
1127 mutex_unlock(&ctx
->mutex
);
1132 * This must be done under the ctx->lock, such as to serialize against
1133 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1134 * calling scheduler related locks and ctx->lock nests inside those.
1136 static __must_check
struct perf_event_context
*
1137 unclone_ctx(struct perf_event_context
*ctx
)
1139 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1141 lockdep_assert_held(&ctx
->lock
);
1144 ctx
->parent_ctx
= NULL
;
1150 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1153 * only top level events have the pid namespace they were created in
1156 event
= event
->parent
;
1158 return task_tgid_nr_ns(p
, event
->ns
);
1161 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1164 * only top level events have the pid namespace they were created in
1167 event
= event
->parent
;
1169 return task_pid_nr_ns(p
, event
->ns
);
1173 * If we inherit events we want to return the parent event id
1176 static u64
primary_event_id(struct perf_event
*event
)
1181 id
= event
->parent
->id
;
1187 * Get the perf_event_context for a task and lock it.
1189 * This has to cope with with the fact that until it is locked,
1190 * the context could get moved to another task.
1192 static struct perf_event_context
*
1193 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1195 struct perf_event_context
*ctx
;
1199 * One of the few rules of preemptible RCU is that one cannot do
1200 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1201 * part of the read side critical section was irqs-enabled -- see
1202 * rcu_read_unlock_special().
1204 * Since ctx->lock nests under rq->lock we must ensure the entire read
1205 * side critical section has interrupts disabled.
1207 local_irq_save(*flags
);
1209 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1212 * If this context is a clone of another, it might
1213 * get swapped for another underneath us by
1214 * perf_event_task_sched_out, though the
1215 * rcu_read_lock() protects us from any context
1216 * getting freed. Lock the context and check if it
1217 * got swapped before we could get the lock, and retry
1218 * if so. If we locked the right context, then it
1219 * can't get swapped on us any more.
1221 raw_spin_lock(&ctx
->lock
);
1222 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1223 raw_spin_unlock(&ctx
->lock
);
1225 local_irq_restore(*flags
);
1229 if (ctx
->task
== TASK_TOMBSTONE
||
1230 !atomic_inc_not_zero(&ctx
->refcount
)) {
1231 raw_spin_unlock(&ctx
->lock
);
1235 WARN_ON_ONCE(ctx
->task
!= task
);
1239 local_irq_restore(*flags
);
1244 * Get the context for a task and increment its pin_count so it
1245 * can't get swapped to another task. This also increments its
1246 * reference count so that the context can't get freed.
1248 static struct perf_event_context
*
1249 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1251 struct perf_event_context
*ctx
;
1252 unsigned long flags
;
1254 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1257 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1262 static void perf_unpin_context(struct perf_event_context
*ctx
)
1264 unsigned long flags
;
1266 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1268 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1272 * Update the record of the current time in a context.
1274 static void update_context_time(struct perf_event_context
*ctx
)
1276 u64 now
= perf_clock();
1278 ctx
->time
+= now
- ctx
->timestamp
;
1279 ctx
->timestamp
= now
;
1282 static u64
perf_event_time(struct perf_event
*event
)
1284 struct perf_event_context
*ctx
= event
->ctx
;
1286 if (is_cgroup_event(event
))
1287 return perf_cgroup_event_time(event
);
1289 return ctx
? ctx
->time
: 0;
1293 * Update the total_time_enabled and total_time_running fields for a event.
1294 * The caller of this function needs to hold the ctx->lock.
1296 static void update_event_times(struct perf_event
*event
)
1298 struct perf_event_context
*ctx
= event
->ctx
;
1301 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1302 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1305 * in cgroup mode, time_enabled represents
1306 * the time the event was enabled AND active
1307 * tasks were in the monitored cgroup. This is
1308 * independent of the activity of the context as
1309 * there may be a mix of cgroup and non-cgroup events.
1311 * That is why we treat cgroup events differently
1314 if (is_cgroup_event(event
))
1315 run_end
= perf_cgroup_event_time(event
);
1316 else if (ctx
->is_active
)
1317 run_end
= ctx
->time
;
1319 run_end
= event
->tstamp_stopped
;
1321 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1323 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1324 run_end
= event
->tstamp_stopped
;
1326 run_end
= perf_event_time(event
);
1328 event
->total_time_running
= run_end
- event
->tstamp_running
;
1333 * Update total_time_enabled and total_time_running for all events in a group.
1335 static void update_group_times(struct perf_event
*leader
)
1337 struct perf_event
*event
;
1339 update_event_times(leader
);
1340 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1341 update_event_times(event
);
1344 static struct list_head
*
1345 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1347 if (event
->attr
.pinned
)
1348 return &ctx
->pinned_groups
;
1350 return &ctx
->flexible_groups
;
1354 * Add a event from the lists for its context.
1355 * Must be called with ctx->mutex and ctx->lock held.
1358 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1360 lockdep_assert_held(&ctx
->lock
);
1362 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1363 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1366 * If we're a stand alone event or group leader, we go to the context
1367 * list, group events are kept attached to the group so that
1368 * perf_group_detach can, at all times, locate all siblings.
1370 if (event
->group_leader
== event
) {
1371 struct list_head
*list
;
1373 if (is_software_event(event
))
1374 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1376 list
= ctx_group_list(event
, ctx
);
1377 list_add_tail(&event
->group_entry
, list
);
1380 if (is_cgroup_event(event
))
1383 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1385 if (event
->attr
.inherit_stat
)
1392 * Initialize event state based on the perf_event_attr::disabled.
1394 static inline void perf_event__state_init(struct perf_event
*event
)
1396 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1397 PERF_EVENT_STATE_INACTIVE
;
1400 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1402 int entry
= sizeof(u64
); /* value */
1406 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1407 size
+= sizeof(u64
);
1409 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1410 size
+= sizeof(u64
);
1412 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1413 entry
+= sizeof(u64
);
1415 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1417 size
+= sizeof(u64
);
1421 event
->read_size
= size
;
1424 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1426 struct perf_sample_data
*data
;
1429 if (sample_type
& PERF_SAMPLE_IP
)
1430 size
+= sizeof(data
->ip
);
1432 if (sample_type
& PERF_SAMPLE_ADDR
)
1433 size
+= sizeof(data
->addr
);
1435 if (sample_type
& PERF_SAMPLE_PERIOD
)
1436 size
+= sizeof(data
->period
);
1438 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1439 size
+= sizeof(data
->weight
);
1441 if (sample_type
& PERF_SAMPLE_READ
)
1442 size
+= event
->read_size
;
1444 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1445 size
+= sizeof(data
->data_src
.val
);
1447 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1448 size
+= sizeof(data
->txn
);
1450 event
->header_size
= size
;
1454 * Called at perf_event creation and when events are attached/detached from a
1457 static void perf_event__header_size(struct perf_event
*event
)
1459 __perf_event_read_size(event
,
1460 event
->group_leader
->nr_siblings
);
1461 __perf_event_header_size(event
, event
->attr
.sample_type
);
1464 static void perf_event__id_header_size(struct perf_event
*event
)
1466 struct perf_sample_data
*data
;
1467 u64 sample_type
= event
->attr
.sample_type
;
1470 if (sample_type
& PERF_SAMPLE_TID
)
1471 size
+= sizeof(data
->tid_entry
);
1473 if (sample_type
& PERF_SAMPLE_TIME
)
1474 size
+= sizeof(data
->time
);
1476 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1477 size
+= sizeof(data
->id
);
1479 if (sample_type
& PERF_SAMPLE_ID
)
1480 size
+= sizeof(data
->id
);
1482 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1483 size
+= sizeof(data
->stream_id
);
1485 if (sample_type
& PERF_SAMPLE_CPU
)
1486 size
+= sizeof(data
->cpu_entry
);
1488 event
->id_header_size
= size
;
1491 static bool perf_event_validate_size(struct perf_event
*event
)
1494 * The values computed here will be over-written when we actually
1497 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1498 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1499 perf_event__id_header_size(event
);
1502 * Sum the lot; should not exceed the 64k limit we have on records.
1503 * Conservative limit to allow for callchains and other variable fields.
1505 if (event
->read_size
+ event
->header_size
+
1506 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1512 static void perf_group_attach(struct perf_event
*event
)
1514 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1517 * We can have double attach due to group movement in perf_event_open.
1519 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1522 event
->attach_state
|= PERF_ATTACH_GROUP
;
1524 if (group_leader
== event
)
1527 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1529 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1530 !is_software_event(event
))
1531 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1533 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1534 group_leader
->nr_siblings
++;
1536 perf_event__header_size(group_leader
);
1538 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1539 perf_event__header_size(pos
);
1543 * Remove a event from the lists for its context.
1544 * Must be called with ctx->mutex and ctx->lock held.
1547 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1549 struct perf_cpu_context
*cpuctx
;
1551 WARN_ON_ONCE(event
->ctx
!= ctx
);
1552 lockdep_assert_held(&ctx
->lock
);
1555 * We can have double detach due to exit/hot-unplug + close.
1557 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1560 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1562 if (is_cgroup_event(event
)) {
1565 * Because cgroup events are always per-cpu events, this will
1566 * always be called from the right CPU.
1568 cpuctx
= __get_cpu_context(ctx
);
1570 * If there are no more cgroup events then clear cgrp to avoid
1571 * stale pointer in update_cgrp_time_from_cpuctx().
1573 if (!ctx
->nr_cgroups
)
1574 cpuctx
->cgrp
= NULL
;
1578 if (event
->attr
.inherit_stat
)
1581 list_del_rcu(&event
->event_entry
);
1583 if (event
->group_leader
== event
)
1584 list_del_init(&event
->group_entry
);
1586 update_group_times(event
);
1589 * If event was in error state, then keep it
1590 * that way, otherwise bogus counts will be
1591 * returned on read(). The only way to get out
1592 * of error state is by explicit re-enabling
1595 if (event
->state
> PERF_EVENT_STATE_OFF
)
1596 event
->state
= PERF_EVENT_STATE_OFF
;
1601 static void perf_group_detach(struct perf_event
*event
)
1603 struct perf_event
*sibling
, *tmp
;
1604 struct list_head
*list
= NULL
;
1607 * We can have double detach due to exit/hot-unplug + close.
1609 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1612 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1615 * If this is a sibling, remove it from its group.
1617 if (event
->group_leader
!= event
) {
1618 list_del_init(&event
->group_entry
);
1619 event
->group_leader
->nr_siblings
--;
1623 if (!list_empty(&event
->group_entry
))
1624 list
= &event
->group_entry
;
1627 * If this was a group event with sibling events then
1628 * upgrade the siblings to singleton events by adding them
1629 * to whatever list we are on.
1631 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1633 list_move_tail(&sibling
->group_entry
, list
);
1634 sibling
->group_leader
= sibling
;
1636 /* Inherit group flags from the previous leader */
1637 sibling
->group_flags
= event
->group_flags
;
1639 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1643 perf_event__header_size(event
->group_leader
);
1645 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1646 perf_event__header_size(tmp
);
1650 * User event without the task.
1652 static bool is_orphaned_event(struct perf_event
*event
)
1654 return event
&& !is_kernel_event(event
) && !event
->owner
;
1658 * Event has a parent but parent's task finished and it's
1659 * alive only because of children holding refference.
1661 static bool is_orphaned_child(struct perf_event
*event
)
1663 return is_orphaned_event(event
->parent
);
1666 static void orphans_remove_work(struct work_struct
*work
);
1668 static void schedule_orphans_remove(struct perf_event_context
*ctx
)
1670 if (!ctx
->task
|| ctx
->orphans_remove_sched
|| !perf_wq
)
1673 if (queue_delayed_work(perf_wq
, &ctx
->orphans_remove
, 1)) {
1675 ctx
->orphans_remove_sched
= true;
1679 static int __init
perf_workqueue_init(void)
1681 perf_wq
= create_singlethread_workqueue("perf");
1682 WARN(!perf_wq
, "failed to create perf workqueue\n");
1683 return perf_wq
? 0 : -1;
1686 core_initcall(perf_workqueue_init
);
1688 static inline int pmu_filter_match(struct perf_event
*event
)
1690 struct pmu
*pmu
= event
->pmu
;
1691 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1695 event_filter_match(struct perf_event
*event
)
1697 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1698 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1702 event_sched_out(struct perf_event
*event
,
1703 struct perf_cpu_context
*cpuctx
,
1704 struct perf_event_context
*ctx
)
1706 u64 tstamp
= perf_event_time(event
);
1709 WARN_ON_ONCE(event
->ctx
!= ctx
);
1710 lockdep_assert_held(&ctx
->lock
);
1713 * An event which could not be activated because of
1714 * filter mismatch still needs to have its timings
1715 * maintained, otherwise bogus information is return
1716 * via read() for time_enabled, time_running:
1718 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1719 && !event_filter_match(event
)) {
1720 delta
= tstamp
- event
->tstamp_stopped
;
1721 event
->tstamp_running
+= delta
;
1722 event
->tstamp_stopped
= tstamp
;
1725 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1728 perf_pmu_disable(event
->pmu
);
1730 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1731 if (event
->pending_disable
) {
1732 event
->pending_disable
= 0;
1733 event
->state
= PERF_EVENT_STATE_OFF
;
1735 event
->tstamp_stopped
= tstamp
;
1736 event
->pmu
->del(event
, 0);
1739 if (!is_software_event(event
))
1740 cpuctx
->active_oncpu
--;
1741 if (!--ctx
->nr_active
)
1742 perf_event_ctx_deactivate(ctx
);
1743 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1745 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1746 cpuctx
->exclusive
= 0;
1748 if (is_orphaned_child(event
))
1749 schedule_orphans_remove(ctx
);
1751 perf_pmu_enable(event
->pmu
);
1755 group_sched_out(struct perf_event
*group_event
,
1756 struct perf_cpu_context
*cpuctx
,
1757 struct perf_event_context
*ctx
)
1759 struct perf_event
*event
;
1760 int state
= group_event
->state
;
1762 event_sched_out(group_event
, cpuctx
, ctx
);
1765 * Schedule out siblings (if any):
1767 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1768 event_sched_out(event
, cpuctx
, ctx
);
1770 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1771 cpuctx
->exclusive
= 0;
1775 * Cross CPU call to remove a performance event
1777 * We disable the event on the hardware level first. After that we
1778 * remove it from the context list.
1781 __perf_remove_from_context(struct perf_event
*event
,
1782 struct perf_cpu_context
*cpuctx
,
1783 struct perf_event_context
*ctx
,
1786 bool detach_group
= (unsigned long)info
;
1788 event_sched_out(event
, cpuctx
, ctx
);
1790 perf_group_detach(event
);
1791 list_del_event(event
, ctx
);
1793 if (!ctx
->nr_events
&& ctx
->is_active
) {
1796 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1797 cpuctx
->task_ctx
= NULL
;
1803 * Remove the event from a task's (or a CPU's) list of events.
1805 * If event->ctx is a cloned context, callers must make sure that
1806 * every task struct that event->ctx->task could possibly point to
1807 * remains valid. This is OK when called from perf_release since
1808 * that only calls us on the top-level context, which can't be a clone.
1809 * When called from perf_event_exit_task, it's OK because the
1810 * context has been detached from its task.
1812 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1814 lockdep_assert_held(&event
->ctx
->mutex
);
1816 event_function_call(event
, __perf_remove_from_context
,
1817 (void *)(unsigned long)detach_group
);
1821 * Cross CPU call to disable a performance event
1823 static void __perf_event_disable(struct perf_event
*event
,
1824 struct perf_cpu_context
*cpuctx
,
1825 struct perf_event_context
*ctx
,
1828 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1831 update_context_time(ctx
);
1832 update_cgrp_time_from_event(event
);
1833 update_group_times(event
);
1834 if (event
== event
->group_leader
)
1835 group_sched_out(event
, cpuctx
, ctx
);
1837 event_sched_out(event
, cpuctx
, ctx
);
1838 event
->state
= PERF_EVENT_STATE_OFF
;
1844 * If event->ctx is a cloned context, callers must make sure that
1845 * every task struct that event->ctx->task could possibly point to
1846 * remains valid. This condition is satisifed when called through
1847 * perf_event_for_each_child or perf_event_for_each because they
1848 * hold the top-level event's child_mutex, so any descendant that
1849 * goes to exit will block in sync_child_event.
1850 * When called from perf_pending_event it's OK because event->ctx
1851 * is the current context on this CPU and preemption is disabled,
1852 * hence we can't get into perf_event_task_sched_out for this context.
1854 static void _perf_event_disable(struct perf_event
*event
)
1856 struct perf_event_context
*ctx
= event
->ctx
;
1858 raw_spin_lock_irq(&ctx
->lock
);
1859 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1860 raw_spin_unlock_irq(&ctx
->lock
);
1863 raw_spin_unlock_irq(&ctx
->lock
);
1865 event_function_call(event
, __perf_event_disable
, NULL
);
1868 void perf_event_disable_local(struct perf_event
*event
)
1870 event_function_local(event
, __perf_event_disable
, NULL
);
1874 * Strictly speaking kernel users cannot create groups and therefore this
1875 * interface does not need the perf_event_ctx_lock() magic.
1877 void perf_event_disable(struct perf_event
*event
)
1879 struct perf_event_context
*ctx
;
1881 ctx
= perf_event_ctx_lock(event
);
1882 _perf_event_disable(event
);
1883 perf_event_ctx_unlock(event
, ctx
);
1885 EXPORT_SYMBOL_GPL(perf_event_disable
);
1887 static void perf_set_shadow_time(struct perf_event
*event
,
1888 struct perf_event_context
*ctx
,
1892 * use the correct time source for the time snapshot
1894 * We could get by without this by leveraging the
1895 * fact that to get to this function, the caller
1896 * has most likely already called update_context_time()
1897 * and update_cgrp_time_xx() and thus both timestamp
1898 * are identical (or very close). Given that tstamp is,
1899 * already adjusted for cgroup, we could say that:
1900 * tstamp - ctx->timestamp
1902 * tstamp - cgrp->timestamp.
1904 * Then, in perf_output_read(), the calculation would
1905 * work with no changes because:
1906 * - event is guaranteed scheduled in
1907 * - no scheduled out in between
1908 * - thus the timestamp would be the same
1910 * But this is a bit hairy.
1912 * So instead, we have an explicit cgroup call to remain
1913 * within the time time source all along. We believe it
1914 * is cleaner and simpler to understand.
1916 if (is_cgroup_event(event
))
1917 perf_cgroup_set_shadow_time(event
, tstamp
);
1919 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1922 #define MAX_INTERRUPTS (~0ULL)
1924 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1925 static void perf_log_itrace_start(struct perf_event
*event
);
1928 event_sched_in(struct perf_event
*event
,
1929 struct perf_cpu_context
*cpuctx
,
1930 struct perf_event_context
*ctx
)
1932 u64 tstamp
= perf_event_time(event
);
1935 lockdep_assert_held(&ctx
->lock
);
1937 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1940 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1941 event
->oncpu
= smp_processor_id();
1944 * Unthrottle events, since we scheduled we might have missed several
1945 * ticks already, also for a heavily scheduling task there is little
1946 * guarantee it'll get a tick in a timely manner.
1948 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1949 perf_log_throttle(event
, 1);
1950 event
->hw
.interrupts
= 0;
1954 * The new state must be visible before we turn it on in the hardware:
1958 perf_pmu_disable(event
->pmu
);
1960 perf_set_shadow_time(event
, ctx
, tstamp
);
1962 perf_log_itrace_start(event
);
1964 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1965 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1971 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1973 if (!is_software_event(event
))
1974 cpuctx
->active_oncpu
++;
1975 if (!ctx
->nr_active
++)
1976 perf_event_ctx_activate(ctx
);
1977 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1980 if (event
->attr
.exclusive
)
1981 cpuctx
->exclusive
= 1;
1983 if (is_orphaned_child(event
))
1984 schedule_orphans_remove(ctx
);
1987 perf_pmu_enable(event
->pmu
);
1993 group_sched_in(struct perf_event
*group_event
,
1994 struct perf_cpu_context
*cpuctx
,
1995 struct perf_event_context
*ctx
)
1997 struct perf_event
*event
, *partial_group
= NULL
;
1998 struct pmu
*pmu
= ctx
->pmu
;
1999 u64 now
= ctx
->time
;
2000 bool simulate
= false;
2002 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2005 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2007 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2008 pmu
->cancel_txn(pmu
);
2009 perf_mux_hrtimer_restart(cpuctx
);
2014 * Schedule in siblings as one group (if any):
2016 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2017 if (event_sched_in(event
, cpuctx
, ctx
)) {
2018 partial_group
= event
;
2023 if (!pmu
->commit_txn(pmu
))
2028 * Groups can be scheduled in as one unit only, so undo any
2029 * partial group before returning:
2030 * The events up to the failed event are scheduled out normally,
2031 * tstamp_stopped will be updated.
2033 * The failed events and the remaining siblings need to have
2034 * their timings updated as if they had gone thru event_sched_in()
2035 * and event_sched_out(). This is required to get consistent timings
2036 * across the group. This also takes care of the case where the group
2037 * could never be scheduled by ensuring tstamp_stopped is set to mark
2038 * the time the event was actually stopped, such that time delta
2039 * calculation in update_event_times() is correct.
2041 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2042 if (event
== partial_group
)
2046 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2047 event
->tstamp_stopped
= now
;
2049 event_sched_out(event
, cpuctx
, ctx
);
2052 event_sched_out(group_event
, cpuctx
, ctx
);
2054 pmu
->cancel_txn(pmu
);
2056 perf_mux_hrtimer_restart(cpuctx
);
2062 * Work out whether we can put this event group on the CPU now.
2064 static int group_can_go_on(struct perf_event
*event
,
2065 struct perf_cpu_context
*cpuctx
,
2069 * Groups consisting entirely of software events can always go on.
2071 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2074 * If an exclusive group is already on, no other hardware
2077 if (cpuctx
->exclusive
)
2080 * If this group is exclusive and there are already
2081 * events on the CPU, it can't go on.
2083 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2086 * Otherwise, try to add it if all previous groups were able
2092 static void add_event_to_ctx(struct perf_event
*event
,
2093 struct perf_event_context
*ctx
)
2095 u64 tstamp
= perf_event_time(event
);
2097 list_add_event(event
, ctx
);
2098 perf_group_attach(event
);
2099 event
->tstamp_enabled
= tstamp
;
2100 event
->tstamp_running
= tstamp
;
2101 event
->tstamp_stopped
= tstamp
;
2104 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2105 struct perf_event_context
*ctx
);
2107 ctx_sched_in(struct perf_event_context
*ctx
,
2108 struct perf_cpu_context
*cpuctx
,
2109 enum event_type_t event_type
,
2110 struct task_struct
*task
);
2112 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2113 struct perf_event_context
*ctx
,
2114 struct task_struct
*task
)
2116 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2118 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2119 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2121 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2124 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2125 struct perf_event_context
*task_ctx
)
2127 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2129 task_ctx_sched_out(cpuctx
, task_ctx
);
2130 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2131 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2132 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2136 * Cross CPU call to install and enable a performance event
2138 * Must be called with ctx->mutex held
2140 static int __perf_install_in_context(void *info
)
2142 struct perf_event_context
*ctx
= info
;
2143 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2144 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2146 raw_spin_lock(&cpuctx
->ctx
.lock
);
2148 raw_spin_lock(&ctx
->lock
);
2150 * If we hit the 'wrong' task, we've since scheduled and
2151 * everything should be sorted, nothing to do!
2154 if (ctx
->task
!= current
)
2158 * If task_ctx is set, it had better be to us.
2160 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
&& cpuctx
->task_ctx
);
2161 } else if (task_ctx
) {
2162 raw_spin_lock(&task_ctx
->lock
);
2165 ctx_resched(cpuctx
, task_ctx
);
2167 perf_ctx_unlock(cpuctx
, task_ctx
);
2173 * Attach a performance event to a context
2176 perf_install_in_context(struct perf_event_context
*ctx
,
2177 struct perf_event
*event
,
2180 struct task_struct
*task
= NULL
;
2182 lockdep_assert_held(&ctx
->mutex
);
2185 if (event
->cpu
!= -1)
2189 * Installing events is tricky because we cannot rely on ctx->is_active
2190 * to be set in case this is the nr_events 0 -> 1 transition.
2192 * So what we do is we add the event to the list here, which will allow
2193 * a future context switch to DTRT and then send a racy IPI. If the IPI
2194 * fails to hit the right task, this means a context switch must have
2195 * happened and that will have taken care of business.
2197 raw_spin_lock_irq(&ctx
->lock
);
2200 * Worse, we cannot even rely on the ctx actually existing anymore. If
2201 * between find_get_context() and perf_install_in_context() the task
2202 * went through perf_event_exit_task() its dead and we should not be
2203 * adding new events.
2205 if (task
== TASK_TOMBSTONE
) {
2206 raw_spin_unlock_irq(&ctx
->lock
);
2209 update_context_time(ctx
);
2211 * Update cgrp time only if current cgrp matches event->cgrp.
2212 * Must be done before calling add_event_to_ctx().
2214 update_cgrp_time_from_event(event
);
2215 add_event_to_ctx(event
, ctx
);
2216 raw_spin_unlock_irq(&ctx
->lock
);
2219 task_function_call(task
, __perf_install_in_context
, ctx
);
2221 cpu_function_call(cpu
, __perf_install_in_context
, ctx
);
2225 * Put a event into inactive state and update time fields.
2226 * Enabling the leader of a group effectively enables all
2227 * the group members that aren't explicitly disabled, so we
2228 * have to update their ->tstamp_enabled also.
2229 * Note: this works for group members as well as group leaders
2230 * since the non-leader members' sibling_lists will be empty.
2232 static void __perf_event_mark_enabled(struct perf_event
*event
)
2234 struct perf_event
*sub
;
2235 u64 tstamp
= perf_event_time(event
);
2237 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2238 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2239 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2240 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2241 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2246 * Cross CPU call to enable a performance event
2248 static void __perf_event_enable(struct perf_event
*event
,
2249 struct perf_cpu_context
*cpuctx
,
2250 struct perf_event_context
*ctx
,
2253 struct perf_event
*leader
= event
->group_leader
;
2254 struct perf_event_context
*task_ctx
;
2256 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2259 update_context_time(ctx
);
2260 __perf_event_mark_enabled(event
);
2262 if (!ctx
->is_active
)
2265 if (!event_filter_match(event
)) {
2266 if (is_cgroup_event(event
)) {
2267 perf_cgroup_set_timestamp(current
, ctx
); // XXX ?
2268 perf_cgroup_defer_enabled(event
);
2274 * If the event is in a group and isn't the group leader,
2275 * then don't put it on unless the group is on.
2277 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2280 task_ctx
= cpuctx
->task_ctx
;
2282 WARN_ON_ONCE(task_ctx
!= ctx
);
2284 ctx_resched(cpuctx
, task_ctx
);
2290 * If event->ctx is a cloned context, callers must make sure that
2291 * every task struct that event->ctx->task could possibly point to
2292 * remains valid. This condition is satisfied when called through
2293 * perf_event_for_each_child or perf_event_for_each as described
2294 * for perf_event_disable.
2296 static void _perf_event_enable(struct perf_event
*event
)
2298 struct perf_event_context
*ctx
= event
->ctx
;
2300 raw_spin_lock_irq(&ctx
->lock
);
2301 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
2302 raw_spin_unlock_irq(&ctx
->lock
);
2307 * If the event is in error state, clear that first.
2309 * That way, if we see the event in error state below, we know that it
2310 * has gone back into error state, as distinct from the task having
2311 * been scheduled away before the cross-call arrived.
2313 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2314 event
->state
= PERF_EVENT_STATE_OFF
;
2315 raw_spin_unlock_irq(&ctx
->lock
);
2317 event_function_call(event
, __perf_event_enable
, NULL
);
2321 * See perf_event_disable();
2323 void perf_event_enable(struct perf_event
*event
)
2325 struct perf_event_context
*ctx
;
2327 ctx
= perf_event_ctx_lock(event
);
2328 _perf_event_enable(event
);
2329 perf_event_ctx_unlock(event
, ctx
);
2331 EXPORT_SYMBOL_GPL(perf_event_enable
);
2333 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2336 * not supported on inherited events
2338 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2341 atomic_add(refresh
, &event
->event_limit
);
2342 _perf_event_enable(event
);
2348 * See perf_event_disable()
2350 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2352 struct perf_event_context
*ctx
;
2355 ctx
= perf_event_ctx_lock(event
);
2356 ret
= _perf_event_refresh(event
, refresh
);
2357 perf_event_ctx_unlock(event
, ctx
);
2361 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2363 static void ctx_sched_out(struct perf_event_context
*ctx
,
2364 struct perf_cpu_context
*cpuctx
,
2365 enum event_type_t event_type
)
2367 int is_active
= ctx
->is_active
;
2368 struct perf_event
*event
;
2370 lockdep_assert_held(&ctx
->lock
);
2372 if (likely(!ctx
->nr_events
)) {
2374 * See __perf_remove_from_context().
2376 WARN_ON_ONCE(ctx
->is_active
);
2378 WARN_ON_ONCE(cpuctx
->task_ctx
);
2382 ctx
->is_active
&= ~event_type
;
2384 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2385 if (!ctx
->is_active
)
2386 cpuctx
->task_ctx
= NULL
;
2389 update_context_time(ctx
);
2390 update_cgrp_time_from_cpuctx(cpuctx
);
2391 if (!ctx
->nr_active
)
2394 perf_pmu_disable(ctx
->pmu
);
2395 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2396 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2397 group_sched_out(event
, cpuctx
, ctx
);
2400 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2401 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2402 group_sched_out(event
, cpuctx
, ctx
);
2404 perf_pmu_enable(ctx
->pmu
);
2408 * Test whether two contexts are equivalent, i.e. whether they have both been
2409 * cloned from the same version of the same context.
2411 * Equivalence is measured using a generation number in the context that is
2412 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2413 * and list_del_event().
2415 static int context_equiv(struct perf_event_context
*ctx1
,
2416 struct perf_event_context
*ctx2
)
2418 lockdep_assert_held(&ctx1
->lock
);
2419 lockdep_assert_held(&ctx2
->lock
);
2421 /* Pinning disables the swap optimization */
2422 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2425 /* If ctx1 is the parent of ctx2 */
2426 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2429 /* If ctx2 is the parent of ctx1 */
2430 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2434 * If ctx1 and ctx2 have the same parent; we flatten the parent
2435 * hierarchy, see perf_event_init_context().
2437 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2438 ctx1
->parent_gen
== ctx2
->parent_gen
)
2445 static void __perf_event_sync_stat(struct perf_event
*event
,
2446 struct perf_event
*next_event
)
2450 if (!event
->attr
.inherit_stat
)
2454 * Update the event value, we cannot use perf_event_read()
2455 * because we're in the middle of a context switch and have IRQs
2456 * disabled, which upsets smp_call_function_single(), however
2457 * we know the event must be on the current CPU, therefore we
2458 * don't need to use it.
2460 switch (event
->state
) {
2461 case PERF_EVENT_STATE_ACTIVE
:
2462 event
->pmu
->read(event
);
2465 case PERF_EVENT_STATE_INACTIVE
:
2466 update_event_times(event
);
2474 * In order to keep per-task stats reliable we need to flip the event
2475 * values when we flip the contexts.
2477 value
= local64_read(&next_event
->count
);
2478 value
= local64_xchg(&event
->count
, value
);
2479 local64_set(&next_event
->count
, value
);
2481 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2482 swap(event
->total_time_running
, next_event
->total_time_running
);
2485 * Since we swizzled the values, update the user visible data too.
2487 perf_event_update_userpage(event
);
2488 perf_event_update_userpage(next_event
);
2491 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2492 struct perf_event_context
*next_ctx
)
2494 struct perf_event
*event
, *next_event
;
2499 update_context_time(ctx
);
2501 event
= list_first_entry(&ctx
->event_list
,
2502 struct perf_event
, event_entry
);
2504 next_event
= list_first_entry(&next_ctx
->event_list
,
2505 struct perf_event
, event_entry
);
2507 while (&event
->event_entry
!= &ctx
->event_list
&&
2508 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2510 __perf_event_sync_stat(event
, next_event
);
2512 event
= list_next_entry(event
, event_entry
);
2513 next_event
= list_next_entry(next_event
, event_entry
);
2517 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2518 struct task_struct
*next
)
2520 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2521 struct perf_event_context
*next_ctx
;
2522 struct perf_event_context
*parent
, *next_parent
;
2523 struct perf_cpu_context
*cpuctx
;
2529 cpuctx
= __get_cpu_context(ctx
);
2530 if (!cpuctx
->task_ctx
)
2534 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2538 parent
= rcu_dereference(ctx
->parent_ctx
);
2539 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2541 /* If neither context have a parent context; they cannot be clones. */
2542 if (!parent
&& !next_parent
)
2545 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2547 * Looks like the two contexts are clones, so we might be
2548 * able to optimize the context switch. We lock both
2549 * contexts and check that they are clones under the
2550 * lock (including re-checking that neither has been
2551 * uncloned in the meantime). It doesn't matter which
2552 * order we take the locks because no other cpu could
2553 * be trying to lock both of these tasks.
2555 raw_spin_lock(&ctx
->lock
);
2556 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2557 if (context_equiv(ctx
, next_ctx
)) {
2558 WRITE_ONCE(ctx
->task
, next
);
2559 WRITE_ONCE(next_ctx
->task
, task
);
2561 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2564 * RCU_INIT_POINTER here is safe because we've not
2565 * modified the ctx and the above modification of
2566 * ctx->task and ctx->task_ctx_data are immaterial
2567 * since those values are always verified under
2568 * ctx->lock which we're now holding.
2570 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2571 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2575 perf_event_sync_stat(ctx
, next_ctx
);
2577 raw_spin_unlock(&next_ctx
->lock
);
2578 raw_spin_unlock(&ctx
->lock
);
2584 raw_spin_lock(&ctx
->lock
);
2585 task_ctx_sched_out(cpuctx
, ctx
);
2586 raw_spin_unlock(&ctx
->lock
);
2590 void perf_sched_cb_dec(struct pmu
*pmu
)
2592 this_cpu_dec(perf_sched_cb_usages
);
2595 void perf_sched_cb_inc(struct pmu
*pmu
)
2597 this_cpu_inc(perf_sched_cb_usages
);
2601 * This function provides the context switch callback to the lower code
2602 * layer. It is invoked ONLY when the context switch callback is enabled.
2604 static void perf_pmu_sched_task(struct task_struct
*prev
,
2605 struct task_struct
*next
,
2608 struct perf_cpu_context
*cpuctx
;
2610 unsigned long flags
;
2615 local_irq_save(flags
);
2619 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2620 if (pmu
->sched_task
) {
2621 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2623 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2625 perf_pmu_disable(pmu
);
2627 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2629 perf_pmu_enable(pmu
);
2631 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2637 local_irq_restore(flags
);
2640 static void perf_event_switch(struct task_struct
*task
,
2641 struct task_struct
*next_prev
, bool sched_in
);
2643 #define for_each_task_context_nr(ctxn) \
2644 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2647 * Called from scheduler to remove the events of the current task,
2648 * with interrupts disabled.
2650 * We stop each event and update the event value in event->count.
2652 * This does not protect us against NMI, but disable()
2653 * sets the disabled bit in the control field of event _before_
2654 * accessing the event control register. If a NMI hits, then it will
2655 * not restart the event.
2657 void __perf_event_task_sched_out(struct task_struct
*task
,
2658 struct task_struct
*next
)
2662 if (__this_cpu_read(perf_sched_cb_usages
))
2663 perf_pmu_sched_task(task
, next
, false);
2665 if (atomic_read(&nr_switch_events
))
2666 perf_event_switch(task
, next
, false);
2668 for_each_task_context_nr(ctxn
)
2669 perf_event_context_sched_out(task
, ctxn
, next
);
2672 * if cgroup events exist on this CPU, then we need
2673 * to check if we have to switch out PMU state.
2674 * cgroup event are system-wide mode only
2676 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2677 perf_cgroup_sched_out(task
, next
);
2680 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2681 struct perf_event_context
*ctx
)
2683 if (!cpuctx
->task_ctx
)
2686 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2689 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2693 * Called with IRQs disabled
2695 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2696 enum event_type_t event_type
)
2698 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2702 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2703 struct perf_cpu_context
*cpuctx
)
2705 struct perf_event
*event
;
2707 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2708 if (event
->state
<= PERF_EVENT_STATE_OFF
)
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
, 1))
2718 group_sched_in(event
, cpuctx
, ctx
);
2721 * If this pinned group hasn't been scheduled,
2722 * put it in error state.
2724 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2725 update_group_times(event
);
2726 event
->state
= PERF_EVENT_STATE_ERROR
;
2732 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2733 struct perf_cpu_context
*cpuctx
)
2735 struct perf_event
*event
;
2738 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2739 /* Ignore events in OFF or ERROR state */
2740 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2743 * Listen to the 'cpu' scheduling filter constraint
2746 if (!event_filter_match(event
))
2749 /* may need to reset tstamp_enabled */
2750 if (is_cgroup_event(event
))
2751 perf_cgroup_mark_enabled(event
, ctx
);
2753 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2754 if (group_sched_in(event
, cpuctx
, ctx
))
2761 ctx_sched_in(struct perf_event_context
*ctx
,
2762 struct perf_cpu_context
*cpuctx
,
2763 enum event_type_t event_type
,
2764 struct task_struct
*task
)
2766 int is_active
= ctx
->is_active
;
2769 lockdep_assert_held(&ctx
->lock
);
2771 if (likely(!ctx
->nr_events
))
2774 ctx
->is_active
|= event_type
;
2777 cpuctx
->task_ctx
= ctx
;
2779 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2783 ctx
->timestamp
= now
;
2784 perf_cgroup_set_timestamp(task
, ctx
);
2786 * First go through the list and put on any pinned groups
2787 * in order to give them the best chance of going on.
2789 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2790 ctx_pinned_sched_in(ctx
, cpuctx
);
2792 /* Then walk through the lower prio flexible groups */
2793 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2794 ctx_flexible_sched_in(ctx
, cpuctx
);
2797 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2798 enum event_type_t event_type
,
2799 struct task_struct
*task
)
2801 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2803 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2806 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2807 struct task_struct
*task
)
2809 struct perf_cpu_context
*cpuctx
;
2811 cpuctx
= __get_cpu_context(ctx
);
2812 if (cpuctx
->task_ctx
== ctx
)
2815 perf_ctx_lock(cpuctx
, ctx
);
2816 perf_pmu_disable(ctx
->pmu
);
2818 * We want to keep the following priority order:
2819 * cpu pinned (that don't need to move), task pinned,
2820 * cpu flexible, task flexible.
2822 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2823 perf_event_sched_in(cpuctx
, ctx
, task
);
2824 perf_pmu_enable(ctx
->pmu
);
2825 perf_ctx_unlock(cpuctx
, ctx
);
2829 * Called from scheduler to add the events of the current task
2830 * with interrupts disabled.
2832 * We restore the event value and then enable it.
2834 * This does not protect us against NMI, but enable()
2835 * sets the enabled bit in the control field of event _before_
2836 * accessing the event control register. If a NMI hits, then it will
2837 * keep the event running.
2839 void __perf_event_task_sched_in(struct task_struct
*prev
,
2840 struct task_struct
*task
)
2842 struct perf_event_context
*ctx
;
2846 * If cgroup events exist on this CPU, then we need to check if we have
2847 * to switch in PMU state; cgroup event are system-wide mode only.
2849 * Since cgroup events are CPU events, we must schedule these in before
2850 * we schedule in the task events.
2852 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2853 perf_cgroup_sched_in(prev
, task
);
2855 for_each_task_context_nr(ctxn
) {
2856 ctx
= task
->perf_event_ctxp
[ctxn
];
2860 perf_event_context_sched_in(ctx
, task
);
2863 if (atomic_read(&nr_switch_events
))
2864 perf_event_switch(task
, prev
, true);
2866 if (__this_cpu_read(perf_sched_cb_usages
))
2867 perf_pmu_sched_task(prev
, task
, true);
2870 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2872 u64 frequency
= event
->attr
.sample_freq
;
2873 u64 sec
= NSEC_PER_SEC
;
2874 u64 divisor
, dividend
;
2876 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2878 count_fls
= fls64(count
);
2879 nsec_fls
= fls64(nsec
);
2880 frequency_fls
= fls64(frequency
);
2884 * We got @count in @nsec, with a target of sample_freq HZ
2885 * the target period becomes:
2888 * period = -------------------
2889 * @nsec * sample_freq
2894 * Reduce accuracy by one bit such that @a and @b converge
2895 * to a similar magnitude.
2897 #define REDUCE_FLS(a, b) \
2899 if (a##_fls > b##_fls) { \
2909 * Reduce accuracy until either term fits in a u64, then proceed with
2910 * the other, so that finally we can do a u64/u64 division.
2912 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2913 REDUCE_FLS(nsec
, frequency
);
2914 REDUCE_FLS(sec
, count
);
2917 if (count_fls
+ sec_fls
> 64) {
2918 divisor
= nsec
* frequency
;
2920 while (count_fls
+ sec_fls
> 64) {
2921 REDUCE_FLS(count
, sec
);
2925 dividend
= count
* sec
;
2927 dividend
= count
* sec
;
2929 while (nsec_fls
+ frequency_fls
> 64) {
2930 REDUCE_FLS(nsec
, frequency
);
2934 divisor
= nsec
* frequency
;
2940 return div64_u64(dividend
, divisor
);
2943 static DEFINE_PER_CPU(int, perf_throttled_count
);
2944 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2946 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2948 struct hw_perf_event
*hwc
= &event
->hw
;
2949 s64 period
, sample_period
;
2952 period
= perf_calculate_period(event
, nsec
, count
);
2954 delta
= (s64
)(period
- hwc
->sample_period
);
2955 delta
= (delta
+ 7) / 8; /* low pass filter */
2957 sample_period
= hwc
->sample_period
+ delta
;
2962 hwc
->sample_period
= sample_period
;
2964 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2966 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2968 local64_set(&hwc
->period_left
, 0);
2971 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2976 * combine freq adjustment with unthrottling to avoid two passes over the
2977 * events. At the same time, make sure, having freq events does not change
2978 * the rate of unthrottling as that would introduce bias.
2980 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2983 struct perf_event
*event
;
2984 struct hw_perf_event
*hwc
;
2985 u64 now
, period
= TICK_NSEC
;
2989 * only need to iterate over all events iff:
2990 * - context have events in frequency mode (needs freq adjust)
2991 * - there are events to unthrottle on this cpu
2993 if (!(ctx
->nr_freq
|| needs_unthr
))
2996 raw_spin_lock(&ctx
->lock
);
2997 perf_pmu_disable(ctx
->pmu
);
2999 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3000 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3003 if (!event_filter_match(event
))
3006 perf_pmu_disable(event
->pmu
);
3010 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3011 hwc
->interrupts
= 0;
3012 perf_log_throttle(event
, 1);
3013 event
->pmu
->start(event
, 0);
3016 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3020 * stop the event and update event->count
3022 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3024 now
= local64_read(&event
->count
);
3025 delta
= now
- hwc
->freq_count_stamp
;
3026 hwc
->freq_count_stamp
= now
;
3030 * reload only if value has changed
3031 * we have stopped the event so tell that
3032 * to perf_adjust_period() to avoid stopping it
3036 perf_adjust_period(event
, period
, delta
, false);
3038 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3040 perf_pmu_enable(event
->pmu
);
3043 perf_pmu_enable(ctx
->pmu
);
3044 raw_spin_unlock(&ctx
->lock
);
3048 * Round-robin a context's events:
3050 static void rotate_ctx(struct perf_event_context
*ctx
)
3053 * Rotate the first entry last of non-pinned groups. Rotation might be
3054 * disabled by the inheritance code.
3056 if (!ctx
->rotate_disable
)
3057 list_rotate_left(&ctx
->flexible_groups
);
3060 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3062 struct perf_event_context
*ctx
= NULL
;
3065 if (cpuctx
->ctx
.nr_events
) {
3066 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3070 ctx
= cpuctx
->task_ctx
;
3071 if (ctx
&& ctx
->nr_events
) {
3072 if (ctx
->nr_events
!= ctx
->nr_active
)
3079 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3080 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3082 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3084 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3086 rotate_ctx(&cpuctx
->ctx
);
3090 perf_event_sched_in(cpuctx
, ctx
, current
);
3092 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3093 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3099 #ifdef CONFIG_NO_HZ_FULL
3100 bool perf_event_can_stop_tick(void)
3102 if (atomic_read(&nr_freq_events
) ||
3103 __this_cpu_read(perf_throttled_count
))
3110 void perf_event_task_tick(void)
3112 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3113 struct perf_event_context
*ctx
, *tmp
;
3116 WARN_ON(!irqs_disabled());
3118 __this_cpu_inc(perf_throttled_seq
);
3119 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3121 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3122 perf_adjust_freq_unthr_context(ctx
, throttled
);
3125 static int event_enable_on_exec(struct perf_event
*event
,
3126 struct perf_event_context
*ctx
)
3128 if (!event
->attr
.enable_on_exec
)
3131 event
->attr
.enable_on_exec
= 0;
3132 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3135 __perf_event_mark_enabled(event
);
3141 * Enable all of a task's events that have been marked enable-on-exec.
3142 * This expects task == current.
3144 static void perf_event_enable_on_exec(int ctxn
)
3146 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3147 struct perf_cpu_context
*cpuctx
;
3148 struct perf_event
*event
;
3149 unsigned long flags
;
3152 local_irq_save(flags
);
3153 ctx
= current
->perf_event_ctxp
[ctxn
];
3154 if (!ctx
|| !ctx
->nr_events
)
3157 cpuctx
= __get_cpu_context(ctx
);
3158 perf_ctx_lock(cpuctx
, ctx
);
3159 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
3160 enabled
|= event_enable_on_exec(event
, ctx
);
3163 * Unclone and reschedule this context if we enabled any event.
3166 clone_ctx
= unclone_ctx(ctx
);
3167 ctx_resched(cpuctx
, ctx
);
3169 perf_ctx_unlock(cpuctx
, ctx
);
3172 local_irq_restore(flags
);
3178 void perf_event_exec(void)
3183 for_each_task_context_nr(ctxn
)
3184 perf_event_enable_on_exec(ctxn
);
3188 struct perf_read_data
{
3189 struct perf_event
*event
;
3195 * Cross CPU call to read the hardware event
3197 static void __perf_event_read(void *info
)
3199 struct perf_read_data
*data
= info
;
3200 struct perf_event
*sub
, *event
= data
->event
;
3201 struct perf_event_context
*ctx
= event
->ctx
;
3202 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3203 struct pmu
*pmu
= event
->pmu
;
3206 * If this is a task context, we need to check whether it is
3207 * the current task context of this cpu. If not it has been
3208 * scheduled out before the smp call arrived. In that case
3209 * event->count would have been updated to a recent sample
3210 * when the event was scheduled out.
3212 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3215 raw_spin_lock(&ctx
->lock
);
3216 if (ctx
->is_active
) {
3217 update_context_time(ctx
);
3218 update_cgrp_time_from_event(event
);
3221 update_event_times(event
);
3222 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3231 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3235 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3236 update_event_times(sub
);
3237 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3239 * Use sibling's PMU rather than @event's since
3240 * sibling could be on different (eg: software) PMU.
3242 sub
->pmu
->read(sub
);
3246 data
->ret
= pmu
->commit_txn(pmu
);
3249 raw_spin_unlock(&ctx
->lock
);
3252 static inline u64
perf_event_count(struct perf_event
*event
)
3254 if (event
->pmu
->count
)
3255 return event
->pmu
->count(event
);
3257 return __perf_event_count(event
);
3261 * NMI-safe method to read a local event, that is an event that
3263 * - either for the current task, or for this CPU
3264 * - does not have inherit set, for inherited task events
3265 * will not be local and we cannot read them atomically
3266 * - must not have a pmu::count method
3268 u64
perf_event_read_local(struct perf_event
*event
)
3270 unsigned long flags
;
3274 * Disabling interrupts avoids all counter scheduling (context
3275 * switches, timer based rotation and IPIs).
3277 local_irq_save(flags
);
3279 /* If this is a per-task event, it must be for current */
3280 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3281 event
->hw
.target
!= current
);
3283 /* If this is a per-CPU event, it must be for this CPU */
3284 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3285 event
->cpu
!= smp_processor_id());
3288 * It must not be an event with inherit set, we cannot read
3289 * all child counters from atomic context.
3291 WARN_ON_ONCE(event
->attr
.inherit
);
3294 * It must not have a pmu::count method, those are not
3297 WARN_ON_ONCE(event
->pmu
->count
);
3300 * If the event is currently on this CPU, its either a per-task event,
3301 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3304 if (event
->oncpu
== smp_processor_id())
3305 event
->pmu
->read(event
);
3307 val
= local64_read(&event
->count
);
3308 local_irq_restore(flags
);
3313 static int perf_event_read(struct perf_event
*event
, bool group
)
3318 * If event is enabled and currently active on a CPU, update the
3319 * value in the event structure:
3321 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3322 struct perf_read_data data
= {
3327 smp_call_function_single(event
->oncpu
,
3328 __perf_event_read
, &data
, 1);
3330 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3331 struct perf_event_context
*ctx
= event
->ctx
;
3332 unsigned long flags
;
3334 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3336 * may read while context is not active
3337 * (e.g., thread is blocked), in that case
3338 * we cannot update context time
3340 if (ctx
->is_active
) {
3341 update_context_time(ctx
);
3342 update_cgrp_time_from_event(event
);
3345 update_group_times(event
);
3347 update_event_times(event
);
3348 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3355 * Initialize the perf_event context in a task_struct:
3357 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3359 raw_spin_lock_init(&ctx
->lock
);
3360 mutex_init(&ctx
->mutex
);
3361 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3362 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3363 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3364 INIT_LIST_HEAD(&ctx
->event_list
);
3365 atomic_set(&ctx
->refcount
, 1);
3366 INIT_DELAYED_WORK(&ctx
->orphans_remove
, orphans_remove_work
);
3369 static struct perf_event_context
*
3370 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3372 struct perf_event_context
*ctx
;
3374 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3378 __perf_event_init_context(ctx
);
3381 get_task_struct(task
);
3388 static struct task_struct
*
3389 find_lively_task_by_vpid(pid_t vpid
)
3391 struct task_struct
*task
;
3398 task
= find_task_by_vpid(vpid
);
3400 get_task_struct(task
);
3404 return ERR_PTR(-ESRCH
);
3406 /* Reuse ptrace permission checks for now. */
3408 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3413 put_task_struct(task
);
3414 return ERR_PTR(err
);
3419 * Returns a matching context with refcount and pincount.
3421 static struct perf_event_context
*
3422 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3423 struct perf_event
*event
)
3425 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3426 struct perf_cpu_context
*cpuctx
;
3427 void *task_ctx_data
= NULL
;
3428 unsigned long flags
;
3430 int cpu
= event
->cpu
;
3433 /* Must be root to operate on a CPU event: */
3434 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3435 return ERR_PTR(-EACCES
);
3438 * We could be clever and allow to attach a event to an
3439 * offline CPU and activate it when the CPU comes up, but
3442 if (!cpu_online(cpu
))
3443 return ERR_PTR(-ENODEV
);
3445 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3454 ctxn
= pmu
->task_ctx_nr
;
3458 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3459 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3460 if (!task_ctx_data
) {
3467 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3469 clone_ctx
= unclone_ctx(ctx
);
3472 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3473 ctx
->task_ctx_data
= task_ctx_data
;
3474 task_ctx_data
= NULL
;
3476 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3481 ctx
= alloc_perf_context(pmu
, task
);
3486 if (task_ctx_data
) {
3487 ctx
->task_ctx_data
= task_ctx_data
;
3488 task_ctx_data
= NULL
;
3492 mutex_lock(&task
->perf_event_mutex
);
3494 * If it has already passed perf_event_exit_task().
3495 * we must see PF_EXITING, it takes this mutex too.
3497 if (task
->flags
& PF_EXITING
)
3499 else if (task
->perf_event_ctxp
[ctxn
])
3504 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3506 mutex_unlock(&task
->perf_event_mutex
);
3508 if (unlikely(err
)) {
3517 kfree(task_ctx_data
);
3521 kfree(task_ctx_data
);
3522 return ERR_PTR(err
);
3525 static void perf_event_free_filter(struct perf_event
*event
);
3526 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3528 static void free_event_rcu(struct rcu_head
*head
)
3530 struct perf_event
*event
;
3532 event
= container_of(head
, struct perf_event
, rcu_head
);
3534 put_pid_ns(event
->ns
);
3535 perf_event_free_filter(event
);
3539 static void ring_buffer_attach(struct perf_event
*event
,
3540 struct ring_buffer
*rb
);
3542 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3547 if (is_cgroup_event(event
))
3548 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3551 static void unaccount_event(struct perf_event
*event
)
3558 if (event
->attach_state
& PERF_ATTACH_TASK
)
3560 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3561 atomic_dec(&nr_mmap_events
);
3562 if (event
->attr
.comm
)
3563 atomic_dec(&nr_comm_events
);
3564 if (event
->attr
.task
)
3565 atomic_dec(&nr_task_events
);
3566 if (event
->attr
.freq
)
3567 atomic_dec(&nr_freq_events
);
3568 if (event
->attr
.context_switch
) {
3570 atomic_dec(&nr_switch_events
);
3572 if (is_cgroup_event(event
))
3574 if (has_branch_stack(event
))
3578 static_key_slow_dec_deferred(&perf_sched_events
);
3580 unaccount_event_cpu(event
, event
->cpu
);
3584 * The following implement mutual exclusion of events on "exclusive" pmus
3585 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3586 * at a time, so we disallow creating events that might conflict, namely:
3588 * 1) cpu-wide events in the presence of per-task events,
3589 * 2) per-task events in the presence of cpu-wide events,
3590 * 3) two matching events on the same context.
3592 * The former two cases are handled in the allocation path (perf_event_alloc(),
3593 * __free_event()), the latter -- before the first perf_install_in_context().
3595 static int exclusive_event_init(struct perf_event
*event
)
3597 struct pmu
*pmu
= event
->pmu
;
3599 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3603 * Prevent co-existence of per-task and cpu-wide events on the
3604 * same exclusive pmu.
3606 * Negative pmu::exclusive_cnt means there are cpu-wide
3607 * events on this "exclusive" pmu, positive means there are
3610 * Since this is called in perf_event_alloc() path, event::ctx
3611 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3612 * to mean "per-task event", because unlike other attach states it
3613 * never gets cleared.
3615 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3616 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3619 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3626 static void exclusive_event_destroy(struct perf_event
*event
)
3628 struct pmu
*pmu
= event
->pmu
;
3630 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3633 /* see comment in exclusive_event_init() */
3634 if (event
->attach_state
& PERF_ATTACH_TASK
)
3635 atomic_dec(&pmu
->exclusive_cnt
);
3637 atomic_inc(&pmu
->exclusive_cnt
);
3640 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3642 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3643 (e1
->cpu
== e2
->cpu
||
3650 /* Called under the same ctx::mutex as perf_install_in_context() */
3651 static bool exclusive_event_installable(struct perf_event
*event
,
3652 struct perf_event_context
*ctx
)
3654 struct perf_event
*iter_event
;
3655 struct pmu
*pmu
= event
->pmu
;
3657 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3660 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3661 if (exclusive_event_match(iter_event
, event
))
3668 static void __free_event(struct perf_event
*event
)
3670 if (!event
->parent
) {
3671 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3672 put_callchain_buffers();
3675 perf_event_free_bpf_prog(event
);
3678 event
->destroy(event
);
3681 put_ctx(event
->ctx
);
3684 exclusive_event_destroy(event
);
3685 module_put(event
->pmu
->module
);
3688 call_rcu(&event
->rcu_head
, free_event_rcu
);
3691 static void _free_event(struct perf_event
*event
)
3693 irq_work_sync(&event
->pending
);
3695 unaccount_event(event
);
3699 * Can happen when we close an event with re-directed output.
3701 * Since we have a 0 refcount, perf_mmap_close() will skip
3702 * over us; possibly making our ring_buffer_put() the last.
3704 mutex_lock(&event
->mmap_mutex
);
3705 ring_buffer_attach(event
, NULL
);
3706 mutex_unlock(&event
->mmap_mutex
);
3709 if (is_cgroup_event(event
))
3710 perf_detach_cgroup(event
);
3712 __free_event(event
);
3716 * Used to free events which have a known refcount of 1, such as in error paths
3717 * where the event isn't exposed yet and inherited events.
3719 static void free_event(struct perf_event
*event
)
3721 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3722 "unexpected event refcount: %ld; ptr=%p\n",
3723 atomic_long_read(&event
->refcount
), event
)) {
3724 /* leak to avoid use-after-free */
3732 * Remove user event from the owner task.
3734 static void perf_remove_from_owner(struct perf_event
*event
)
3736 struct task_struct
*owner
;
3739 owner
= ACCESS_ONCE(event
->owner
);
3741 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3742 * !owner it means the list deletion is complete and we can indeed
3743 * free this event, otherwise we need to serialize on
3744 * owner->perf_event_mutex.
3746 smp_read_barrier_depends();
3749 * Since delayed_put_task_struct() also drops the last
3750 * task reference we can safely take a new reference
3751 * while holding the rcu_read_lock().
3753 get_task_struct(owner
);
3759 * If we're here through perf_event_exit_task() we're already
3760 * holding ctx->mutex which would be an inversion wrt. the
3761 * normal lock order.
3763 * However we can safely take this lock because its the child
3766 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3769 * We have to re-check the event->owner field, if it is cleared
3770 * we raced with perf_event_exit_task(), acquiring the mutex
3771 * ensured they're done, and we can proceed with freeing the
3775 list_del_init(&event
->owner_entry
);
3776 mutex_unlock(&owner
->perf_event_mutex
);
3777 put_task_struct(owner
);
3781 static void put_event(struct perf_event
*event
)
3783 struct perf_event_context
*ctx
;
3785 if (!atomic_long_dec_and_test(&event
->refcount
))
3788 if (!is_kernel_event(event
))
3789 perf_remove_from_owner(event
);
3792 * There are two ways this annotation is useful:
3794 * 1) there is a lock recursion from perf_event_exit_task
3795 * see the comment there.
3797 * 2) there is a lock-inversion with mmap_sem through
3798 * perf_read_group(), which takes faults while
3799 * holding ctx->mutex, however this is called after
3800 * the last filedesc died, so there is no possibility
3801 * to trigger the AB-BA case.
3803 ctx
= perf_event_ctx_lock_nested(event
, SINGLE_DEPTH_NESTING
);
3804 WARN_ON_ONCE(ctx
->parent_ctx
);
3805 perf_remove_from_context(event
, true);
3806 perf_event_ctx_unlock(event
, ctx
);
3811 int perf_event_release_kernel(struct perf_event
*event
)
3816 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3819 * Called when the last reference to the file is gone.
3821 static int perf_release(struct inode
*inode
, struct file
*file
)
3823 put_event(file
->private_data
);
3828 * Remove all orphanes events from the context.
3830 static void orphans_remove_work(struct work_struct
*work
)
3832 struct perf_event_context
*ctx
;
3833 struct perf_event
*event
, *tmp
;
3835 ctx
= container_of(work
, struct perf_event_context
,
3836 orphans_remove
.work
);
3838 mutex_lock(&ctx
->mutex
);
3839 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
) {
3840 struct perf_event
*parent_event
= event
->parent
;
3842 if (!is_orphaned_child(event
))
3845 perf_remove_from_context(event
, true);
3847 mutex_lock(&parent_event
->child_mutex
);
3848 list_del_init(&event
->child_list
);
3849 mutex_unlock(&parent_event
->child_mutex
);
3852 put_event(parent_event
);
3855 raw_spin_lock_irq(&ctx
->lock
);
3856 ctx
->orphans_remove_sched
= false;
3857 raw_spin_unlock_irq(&ctx
->lock
);
3858 mutex_unlock(&ctx
->mutex
);
3863 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3865 struct perf_event
*child
;
3871 mutex_lock(&event
->child_mutex
);
3873 (void)perf_event_read(event
, false);
3874 total
+= perf_event_count(event
);
3876 *enabled
+= event
->total_time_enabled
+
3877 atomic64_read(&event
->child_total_time_enabled
);
3878 *running
+= event
->total_time_running
+
3879 atomic64_read(&event
->child_total_time_running
);
3881 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3882 (void)perf_event_read(child
, false);
3883 total
+= perf_event_count(child
);
3884 *enabled
+= child
->total_time_enabled
;
3885 *running
+= child
->total_time_running
;
3887 mutex_unlock(&event
->child_mutex
);
3891 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3893 static int __perf_read_group_add(struct perf_event
*leader
,
3894 u64 read_format
, u64
*values
)
3896 struct perf_event
*sub
;
3897 int n
= 1; /* skip @nr */
3900 ret
= perf_event_read(leader
, true);
3905 * Since we co-schedule groups, {enabled,running} times of siblings
3906 * will be identical to those of the leader, so we only publish one
3909 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3910 values
[n
++] += leader
->total_time_enabled
+
3911 atomic64_read(&leader
->child_total_time_enabled
);
3914 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3915 values
[n
++] += leader
->total_time_running
+
3916 atomic64_read(&leader
->child_total_time_running
);
3920 * Write {count,id} tuples for every sibling.
3922 values
[n
++] += perf_event_count(leader
);
3923 if (read_format
& PERF_FORMAT_ID
)
3924 values
[n
++] = primary_event_id(leader
);
3926 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3927 values
[n
++] += perf_event_count(sub
);
3928 if (read_format
& PERF_FORMAT_ID
)
3929 values
[n
++] = primary_event_id(sub
);
3935 static int perf_read_group(struct perf_event
*event
,
3936 u64 read_format
, char __user
*buf
)
3938 struct perf_event
*leader
= event
->group_leader
, *child
;
3939 struct perf_event_context
*ctx
= leader
->ctx
;
3943 lockdep_assert_held(&ctx
->mutex
);
3945 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
3949 values
[0] = 1 + leader
->nr_siblings
;
3952 * By locking the child_mutex of the leader we effectively
3953 * lock the child list of all siblings.. XXX explain how.
3955 mutex_lock(&leader
->child_mutex
);
3957 ret
= __perf_read_group_add(leader
, read_format
, values
);
3961 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
3962 ret
= __perf_read_group_add(child
, read_format
, values
);
3967 mutex_unlock(&leader
->child_mutex
);
3969 ret
= event
->read_size
;
3970 if (copy_to_user(buf
, values
, event
->read_size
))
3975 mutex_unlock(&leader
->child_mutex
);
3981 static int perf_read_one(struct perf_event
*event
,
3982 u64 read_format
, char __user
*buf
)
3984 u64 enabled
, running
;
3988 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3989 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3990 values
[n
++] = enabled
;
3991 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3992 values
[n
++] = running
;
3993 if (read_format
& PERF_FORMAT_ID
)
3994 values
[n
++] = primary_event_id(event
);
3996 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3999 return n
* sizeof(u64
);
4002 static bool is_event_hup(struct perf_event
*event
)
4006 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
4009 mutex_lock(&event
->child_mutex
);
4010 no_children
= list_empty(&event
->child_list
);
4011 mutex_unlock(&event
->child_mutex
);
4016 * Read the performance event - simple non blocking version for now
4019 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4021 u64 read_format
= event
->attr
.read_format
;
4025 * Return end-of-file for a read on a event that is in
4026 * error state (i.e. because it was pinned but it couldn't be
4027 * scheduled on to the CPU at some point).
4029 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4032 if (count
< event
->read_size
)
4035 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4036 if (read_format
& PERF_FORMAT_GROUP
)
4037 ret
= perf_read_group(event
, read_format
, buf
);
4039 ret
= perf_read_one(event
, read_format
, buf
);
4045 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4047 struct perf_event
*event
= file
->private_data
;
4048 struct perf_event_context
*ctx
;
4051 ctx
= perf_event_ctx_lock(event
);
4052 ret
= __perf_read(event
, buf
, count
);
4053 perf_event_ctx_unlock(event
, ctx
);
4058 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4060 struct perf_event
*event
= file
->private_data
;
4061 struct ring_buffer
*rb
;
4062 unsigned int events
= POLLHUP
;
4064 poll_wait(file
, &event
->waitq
, wait
);
4066 if (is_event_hup(event
))
4070 * Pin the event->rb by taking event->mmap_mutex; otherwise
4071 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4073 mutex_lock(&event
->mmap_mutex
);
4076 events
= atomic_xchg(&rb
->poll
, 0);
4077 mutex_unlock(&event
->mmap_mutex
);
4081 static void _perf_event_reset(struct perf_event
*event
)
4083 (void)perf_event_read(event
, false);
4084 local64_set(&event
->count
, 0);
4085 perf_event_update_userpage(event
);
4089 * Holding the top-level event's child_mutex means that any
4090 * descendant process that has inherited this event will block
4091 * in sync_child_event if it goes to exit, thus satisfying the
4092 * task existence requirements of perf_event_enable/disable.
4094 static void perf_event_for_each_child(struct perf_event
*event
,
4095 void (*func
)(struct perf_event
*))
4097 struct perf_event
*child
;
4099 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4101 mutex_lock(&event
->child_mutex
);
4103 list_for_each_entry(child
, &event
->child_list
, child_list
)
4105 mutex_unlock(&event
->child_mutex
);
4108 static void perf_event_for_each(struct perf_event
*event
,
4109 void (*func
)(struct perf_event
*))
4111 struct perf_event_context
*ctx
= event
->ctx
;
4112 struct perf_event
*sibling
;
4114 lockdep_assert_held(&ctx
->mutex
);
4116 event
= event
->group_leader
;
4118 perf_event_for_each_child(event
, func
);
4119 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4120 perf_event_for_each_child(sibling
, func
);
4123 static void __perf_event_period(struct perf_event
*event
,
4124 struct perf_cpu_context
*cpuctx
,
4125 struct perf_event_context
*ctx
,
4128 u64 value
= *((u64
*)info
);
4131 if (event
->attr
.freq
) {
4132 event
->attr
.sample_freq
= value
;
4134 event
->attr
.sample_period
= value
;
4135 event
->hw
.sample_period
= value
;
4138 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4140 perf_pmu_disable(ctx
->pmu
);
4141 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4144 local64_set(&event
->hw
.period_left
, 0);
4147 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4148 perf_pmu_enable(ctx
->pmu
);
4152 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4156 if (!is_sampling_event(event
))
4159 if (copy_from_user(&value
, arg
, sizeof(value
)))
4165 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4168 event_function_call(event
, __perf_event_period
, &value
);
4173 static const struct file_operations perf_fops
;
4175 static inline int perf_fget_light(int fd
, struct fd
*p
)
4177 struct fd f
= fdget(fd
);
4181 if (f
.file
->f_op
!= &perf_fops
) {
4189 static int perf_event_set_output(struct perf_event
*event
,
4190 struct perf_event
*output_event
);
4191 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4192 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4194 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4196 void (*func
)(struct perf_event
*);
4200 case PERF_EVENT_IOC_ENABLE
:
4201 func
= _perf_event_enable
;
4203 case PERF_EVENT_IOC_DISABLE
:
4204 func
= _perf_event_disable
;
4206 case PERF_EVENT_IOC_RESET
:
4207 func
= _perf_event_reset
;
4210 case PERF_EVENT_IOC_REFRESH
:
4211 return _perf_event_refresh(event
, arg
);
4213 case PERF_EVENT_IOC_PERIOD
:
4214 return perf_event_period(event
, (u64 __user
*)arg
);
4216 case PERF_EVENT_IOC_ID
:
4218 u64 id
= primary_event_id(event
);
4220 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4225 case PERF_EVENT_IOC_SET_OUTPUT
:
4229 struct perf_event
*output_event
;
4231 ret
= perf_fget_light(arg
, &output
);
4234 output_event
= output
.file
->private_data
;
4235 ret
= perf_event_set_output(event
, output_event
);
4238 ret
= perf_event_set_output(event
, NULL
);
4243 case PERF_EVENT_IOC_SET_FILTER
:
4244 return perf_event_set_filter(event
, (void __user
*)arg
);
4246 case PERF_EVENT_IOC_SET_BPF
:
4247 return perf_event_set_bpf_prog(event
, arg
);
4253 if (flags
& PERF_IOC_FLAG_GROUP
)
4254 perf_event_for_each(event
, func
);
4256 perf_event_for_each_child(event
, func
);
4261 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4263 struct perf_event
*event
= file
->private_data
;
4264 struct perf_event_context
*ctx
;
4267 ctx
= perf_event_ctx_lock(event
);
4268 ret
= _perf_ioctl(event
, cmd
, arg
);
4269 perf_event_ctx_unlock(event
, ctx
);
4274 #ifdef CONFIG_COMPAT
4275 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4278 switch (_IOC_NR(cmd
)) {
4279 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4280 case _IOC_NR(PERF_EVENT_IOC_ID
):
4281 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4282 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4283 cmd
&= ~IOCSIZE_MASK
;
4284 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4288 return perf_ioctl(file
, cmd
, arg
);
4291 # define perf_compat_ioctl NULL
4294 int perf_event_task_enable(void)
4296 struct perf_event_context
*ctx
;
4297 struct perf_event
*event
;
4299 mutex_lock(¤t
->perf_event_mutex
);
4300 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4301 ctx
= perf_event_ctx_lock(event
);
4302 perf_event_for_each_child(event
, _perf_event_enable
);
4303 perf_event_ctx_unlock(event
, ctx
);
4305 mutex_unlock(¤t
->perf_event_mutex
);
4310 int perf_event_task_disable(void)
4312 struct perf_event_context
*ctx
;
4313 struct perf_event
*event
;
4315 mutex_lock(¤t
->perf_event_mutex
);
4316 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4317 ctx
= perf_event_ctx_lock(event
);
4318 perf_event_for_each_child(event
, _perf_event_disable
);
4319 perf_event_ctx_unlock(event
, ctx
);
4321 mutex_unlock(¤t
->perf_event_mutex
);
4326 static int perf_event_index(struct perf_event
*event
)
4328 if (event
->hw
.state
& PERF_HES_STOPPED
)
4331 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4334 return event
->pmu
->event_idx(event
);
4337 static void calc_timer_values(struct perf_event
*event
,
4344 *now
= perf_clock();
4345 ctx_time
= event
->shadow_ctx_time
+ *now
;
4346 *enabled
= ctx_time
- event
->tstamp_enabled
;
4347 *running
= ctx_time
- event
->tstamp_running
;
4350 static void perf_event_init_userpage(struct perf_event
*event
)
4352 struct perf_event_mmap_page
*userpg
;
4353 struct ring_buffer
*rb
;
4356 rb
= rcu_dereference(event
->rb
);
4360 userpg
= rb
->user_page
;
4362 /* Allow new userspace to detect that bit 0 is deprecated */
4363 userpg
->cap_bit0_is_deprecated
= 1;
4364 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4365 userpg
->data_offset
= PAGE_SIZE
;
4366 userpg
->data_size
= perf_data_size(rb
);
4372 void __weak
arch_perf_update_userpage(
4373 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4378 * Callers need to ensure there can be no nesting of this function, otherwise
4379 * the seqlock logic goes bad. We can not serialize this because the arch
4380 * code calls this from NMI context.
4382 void perf_event_update_userpage(struct perf_event
*event
)
4384 struct perf_event_mmap_page
*userpg
;
4385 struct ring_buffer
*rb
;
4386 u64 enabled
, running
, now
;
4389 rb
= rcu_dereference(event
->rb
);
4394 * compute total_time_enabled, total_time_running
4395 * based on snapshot values taken when the event
4396 * was last scheduled in.
4398 * we cannot simply called update_context_time()
4399 * because of locking issue as we can be called in
4402 calc_timer_values(event
, &now
, &enabled
, &running
);
4404 userpg
= rb
->user_page
;
4406 * Disable preemption so as to not let the corresponding user-space
4407 * spin too long if we get preempted.
4412 userpg
->index
= perf_event_index(event
);
4413 userpg
->offset
= perf_event_count(event
);
4415 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4417 userpg
->time_enabled
= enabled
+
4418 atomic64_read(&event
->child_total_time_enabled
);
4420 userpg
->time_running
= running
+
4421 atomic64_read(&event
->child_total_time_running
);
4423 arch_perf_update_userpage(event
, userpg
, now
);
4432 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4434 struct perf_event
*event
= vma
->vm_file
->private_data
;
4435 struct ring_buffer
*rb
;
4436 int ret
= VM_FAULT_SIGBUS
;
4438 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4439 if (vmf
->pgoff
== 0)
4445 rb
= rcu_dereference(event
->rb
);
4449 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4452 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4456 get_page(vmf
->page
);
4457 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4458 vmf
->page
->index
= vmf
->pgoff
;
4467 static void ring_buffer_attach(struct perf_event
*event
,
4468 struct ring_buffer
*rb
)
4470 struct ring_buffer
*old_rb
= NULL
;
4471 unsigned long flags
;
4475 * Should be impossible, we set this when removing
4476 * event->rb_entry and wait/clear when adding event->rb_entry.
4478 WARN_ON_ONCE(event
->rcu_pending
);
4481 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4482 list_del_rcu(&event
->rb_entry
);
4483 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4485 event
->rcu_batches
= get_state_synchronize_rcu();
4486 event
->rcu_pending
= 1;
4490 if (event
->rcu_pending
) {
4491 cond_synchronize_rcu(event
->rcu_batches
);
4492 event
->rcu_pending
= 0;
4495 spin_lock_irqsave(&rb
->event_lock
, flags
);
4496 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4497 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4500 rcu_assign_pointer(event
->rb
, rb
);
4503 ring_buffer_put(old_rb
);
4505 * Since we detached before setting the new rb, so that we
4506 * could attach the new rb, we could have missed a wakeup.
4509 wake_up_all(&event
->waitq
);
4513 static void ring_buffer_wakeup(struct perf_event
*event
)
4515 struct ring_buffer
*rb
;
4518 rb
= rcu_dereference(event
->rb
);
4520 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4521 wake_up_all(&event
->waitq
);
4526 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4528 struct ring_buffer
*rb
;
4531 rb
= rcu_dereference(event
->rb
);
4533 if (!atomic_inc_not_zero(&rb
->refcount
))
4541 void ring_buffer_put(struct ring_buffer
*rb
)
4543 if (!atomic_dec_and_test(&rb
->refcount
))
4546 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4548 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4551 static void perf_mmap_open(struct vm_area_struct
*vma
)
4553 struct perf_event
*event
= vma
->vm_file
->private_data
;
4555 atomic_inc(&event
->mmap_count
);
4556 atomic_inc(&event
->rb
->mmap_count
);
4559 atomic_inc(&event
->rb
->aux_mmap_count
);
4561 if (event
->pmu
->event_mapped
)
4562 event
->pmu
->event_mapped(event
);
4566 * A buffer can be mmap()ed multiple times; either directly through the same
4567 * event, or through other events by use of perf_event_set_output().
4569 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4570 * the buffer here, where we still have a VM context. This means we need
4571 * to detach all events redirecting to us.
4573 static void perf_mmap_close(struct vm_area_struct
*vma
)
4575 struct perf_event
*event
= vma
->vm_file
->private_data
;
4577 struct ring_buffer
*rb
= ring_buffer_get(event
);
4578 struct user_struct
*mmap_user
= rb
->mmap_user
;
4579 int mmap_locked
= rb
->mmap_locked
;
4580 unsigned long size
= perf_data_size(rb
);
4582 if (event
->pmu
->event_unmapped
)
4583 event
->pmu
->event_unmapped(event
);
4586 * rb->aux_mmap_count will always drop before rb->mmap_count and
4587 * event->mmap_count, so it is ok to use event->mmap_mutex to
4588 * serialize with perf_mmap here.
4590 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4591 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4592 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4593 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4596 mutex_unlock(&event
->mmap_mutex
);
4599 atomic_dec(&rb
->mmap_count
);
4601 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4604 ring_buffer_attach(event
, NULL
);
4605 mutex_unlock(&event
->mmap_mutex
);
4607 /* If there's still other mmap()s of this buffer, we're done. */
4608 if (atomic_read(&rb
->mmap_count
))
4612 * No other mmap()s, detach from all other events that might redirect
4613 * into the now unreachable buffer. Somewhat complicated by the
4614 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4618 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4619 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4621 * This event is en-route to free_event() which will
4622 * detach it and remove it from the list.
4628 mutex_lock(&event
->mmap_mutex
);
4630 * Check we didn't race with perf_event_set_output() which can
4631 * swizzle the rb from under us while we were waiting to
4632 * acquire mmap_mutex.
4634 * If we find a different rb; ignore this event, a next
4635 * iteration will no longer find it on the list. We have to
4636 * still restart the iteration to make sure we're not now
4637 * iterating the wrong list.
4639 if (event
->rb
== rb
)
4640 ring_buffer_attach(event
, NULL
);
4642 mutex_unlock(&event
->mmap_mutex
);
4646 * Restart the iteration; either we're on the wrong list or
4647 * destroyed its integrity by doing a deletion.
4654 * It could be there's still a few 0-ref events on the list; they'll
4655 * get cleaned up by free_event() -- they'll also still have their
4656 * ref on the rb and will free it whenever they are done with it.
4658 * Aside from that, this buffer is 'fully' detached and unmapped,
4659 * undo the VM accounting.
4662 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4663 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4664 free_uid(mmap_user
);
4667 ring_buffer_put(rb
); /* could be last */
4670 static const struct vm_operations_struct perf_mmap_vmops
= {
4671 .open
= perf_mmap_open
,
4672 .close
= perf_mmap_close
, /* non mergable */
4673 .fault
= perf_mmap_fault
,
4674 .page_mkwrite
= perf_mmap_fault
,
4677 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4679 struct perf_event
*event
= file
->private_data
;
4680 unsigned long user_locked
, user_lock_limit
;
4681 struct user_struct
*user
= current_user();
4682 unsigned long locked
, lock_limit
;
4683 struct ring_buffer
*rb
= NULL
;
4684 unsigned long vma_size
;
4685 unsigned long nr_pages
;
4686 long user_extra
= 0, extra
= 0;
4687 int ret
= 0, flags
= 0;
4690 * Don't allow mmap() of inherited per-task counters. This would
4691 * create a performance issue due to all children writing to the
4694 if (event
->cpu
== -1 && event
->attr
.inherit
)
4697 if (!(vma
->vm_flags
& VM_SHARED
))
4700 vma_size
= vma
->vm_end
- vma
->vm_start
;
4702 if (vma
->vm_pgoff
== 0) {
4703 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4706 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4707 * mapped, all subsequent mappings should have the same size
4708 * and offset. Must be above the normal perf buffer.
4710 u64 aux_offset
, aux_size
;
4715 nr_pages
= vma_size
/ PAGE_SIZE
;
4717 mutex_lock(&event
->mmap_mutex
);
4724 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4725 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4727 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4730 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4733 /* already mapped with a different offset */
4734 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4737 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4740 /* already mapped with a different size */
4741 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4744 if (!is_power_of_2(nr_pages
))
4747 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4750 if (rb_has_aux(rb
)) {
4751 atomic_inc(&rb
->aux_mmap_count
);
4756 atomic_set(&rb
->aux_mmap_count
, 1);
4757 user_extra
= nr_pages
;
4763 * If we have rb pages ensure they're a power-of-two number, so we
4764 * can do bitmasks instead of modulo.
4766 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4769 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4772 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4774 mutex_lock(&event
->mmap_mutex
);
4776 if (event
->rb
->nr_pages
!= nr_pages
) {
4781 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4783 * Raced against perf_mmap_close() through
4784 * perf_event_set_output(). Try again, hope for better
4787 mutex_unlock(&event
->mmap_mutex
);
4794 user_extra
= nr_pages
+ 1;
4797 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4800 * Increase the limit linearly with more CPUs:
4802 user_lock_limit
*= num_online_cpus();
4804 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4806 if (user_locked
> user_lock_limit
)
4807 extra
= user_locked
- user_lock_limit
;
4809 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4810 lock_limit
>>= PAGE_SHIFT
;
4811 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4813 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4814 !capable(CAP_IPC_LOCK
)) {
4819 WARN_ON(!rb
&& event
->rb
);
4821 if (vma
->vm_flags
& VM_WRITE
)
4822 flags
|= RING_BUFFER_WRITABLE
;
4825 rb
= rb_alloc(nr_pages
,
4826 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4834 atomic_set(&rb
->mmap_count
, 1);
4835 rb
->mmap_user
= get_current_user();
4836 rb
->mmap_locked
= extra
;
4838 ring_buffer_attach(event
, rb
);
4840 perf_event_init_userpage(event
);
4841 perf_event_update_userpage(event
);
4843 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4844 event
->attr
.aux_watermark
, flags
);
4846 rb
->aux_mmap_locked
= extra
;
4851 atomic_long_add(user_extra
, &user
->locked_vm
);
4852 vma
->vm_mm
->pinned_vm
+= extra
;
4854 atomic_inc(&event
->mmap_count
);
4856 atomic_dec(&rb
->mmap_count
);
4859 mutex_unlock(&event
->mmap_mutex
);
4862 * Since pinned accounting is per vm we cannot allow fork() to copy our
4865 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4866 vma
->vm_ops
= &perf_mmap_vmops
;
4868 if (event
->pmu
->event_mapped
)
4869 event
->pmu
->event_mapped(event
);
4874 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4876 struct inode
*inode
= file_inode(filp
);
4877 struct perf_event
*event
= filp
->private_data
;
4880 mutex_lock(&inode
->i_mutex
);
4881 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4882 mutex_unlock(&inode
->i_mutex
);
4890 static const struct file_operations perf_fops
= {
4891 .llseek
= no_llseek
,
4892 .release
= perf_release
,
4895 .unlocked_ioctl
= perf_ioctl
,
4896 .compat_ioctl
= perf_compat_ioctl
,
4898 .fasync
= perf_fasync
,
4904 * If there's data, ensure we set the poll() state and publish everything
4905 * to user-space before waking everybody up.
4908 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
4910 /* only the parent has fasync state */
4912 event
= event
->parent
;
4913 return &event
->fasync
;
4916 void perf_event_wakeup(struct perf_event
*event
)
4918 ring_buffer_wakeup(event
);
4920 if (event
->pending_kill
) {
4921 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
4922 event
->pending_kill
= 0;
4926 static void perf_pending_event(struct irq_work
*entry
)
4928 struct perf_event
*event
= container_of(entry
,
4929 struct perf_event
, pending
);
4932 rctx
= perf_swevent_get_recursion_context();
4934 * If we 'fail' here, that's OK, it means recursion is already disabled
4935 * and we won't recurse 'further'.
4938 if (event
->pending_disable
) {
4939 event
->pending_disable
= 0;
4940 perf_event_disable_local(event
);
4943 if (event
->pending_wakeup
) {
4944 event
->pending_wakeup
= 0;
4945 perf_event_wakeup(event
);
4949 perf_swevent_put_recursion_context(rctx
);
4953 * We assume there is only KVM supporting the callbacks.
4954 * Later on, we might change it to a list if there is
4955 * another virtualization implementation supporting the callbacks.
4957 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4959 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4961 perf_guest_cbs
= cbs
;
4964 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4966 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4968 perf_guest_cbs
= NULL
;
4971 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4974 perf_output_sample_regs(struct perf_output_handle
*handle
,
4975 struct pt_regs
*regs
, u64 mask
)
4979 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4980 sizeof(mask
) * BITS_PER_BYTE
) {
4983 val
= perf_reg_value(regs
, bit
);
4984 perf_output_put(handle
, val
);
4988 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
4989 struct pt_regs
*regs
,
4990 struct pt_regs
*regs_user_copy
)
4992 if (user_mode(regs
)) {
4993 regs_user
->abi
= perf_reg_abi(current
);
4994 regs_user
->regs
= regs
;
4995 } else if (current
->mm
) {
4996 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
4998 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
4999 regs_user
->regs
= NULL
;
5003 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5004 struct pt_regs
*regs
)
5006 regs_intr
->regs
= regs
;
5007 regs_intr
->abi
= perf_reg_abi(current
);
5012 * Get remaining task size from user stack pointer.
5014 * It'd be better to take stack vma map and limit this more
5015 * precisly, but there's no way to get it safely under interrupt,
5016 * so using TASK_SIZE as limit.
5018 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5020 unsigned long addr
= perf_user_stack_pointer(regs
);
5022 if (!addr
|| addr
>= TASK_SIZE
)
5025 return TASK_SIZE
- addr
;
5029 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5030 struct pt_regs
*regs
)
5034 /* No regs, no stack pointer, no dump. */
5039 * Check if we fit in with the requested stack size into the:
5041 * If we don't, we limit the size to the TASK_SIZE.
5043 * - remaining sample size
5044 * If we don't, we customize the stack size to
5045 * fit in to the remaining sample size.
5048 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5049 stack_size
= min(stack_size
, (u16
) task_size
);
5051 /* Current header size plus static size and dynamic size. */
5052 header_size
+= 2 * sizeof(u64
);
5054 /* Do we fit in with the current stack dump size? */
5055 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5057 * If we overflow the maximum size for the sample,
5058 * we customize the stack dump size to fit in.
5060 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5061 stack_size
= round_up(stack_size
, sizeof(u64
));
5068 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5069 struct pt_regs
*regs
)
5071 /* Case of a kernel thread, nothing to dump */
5074 perf_output_put(handle
, size
);
5083 * - the size requested by user or the best one we can fit
5084 * in to the sample max size
5086 * - user stack dump data
5088 * - the actual dumped size
5092 perf_output_put(handle
, dump_size
);
5095 sp
= perf_user_stack_pointer(regs
);
5096 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5097 dyn_size
= dump_size
- rem
;
5099 perf_output_skip(handle
, rem
);
5102 perf_output_put(handle
, dyn_size
);
5106 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5107 struct perf_sample_data
*data
,
5108 struct perf_event
*event
)
5110 u64 sample_type
= event
->attr
.sample_type
;
5112 data
->type
= sample_type
;
5113 header
->size
+= event
->id_header_size
;
5115 if (sample_type
& PERF_SAMPLE_TID
) {
5116 /* namespace issues */
5117 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5118 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5121 if (sample_type
& PERF_SAMPLE_TIME
)
5122 data
->time
= perf_event_clock(event
);
5124 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5125 data
->id
= primary_event_id(event
);
5127 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5128 data
->stream_id
= event
->id
;
5130 if (sample_type
& PERF_SAMPLE_CPU
) {
5131 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5132 data
->cpu_entry
.reserved
= 0;
5136 void perf_event_header__init_id(struct perf_event_header
*header
,
5137 struct perf_sample_data
*data
,
5138 struct perf_event
*event
)
5140 if (event
->attr
.sample_id_all
)
5141 __perf_event_header__init_id(header
, data
, event
);
5144 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5145 struct perf_sample_data
*data
)
5147 u64 sample_type
= data
->type
;
5149 if (sample_type
& PERF_SAMPLE_TID
)
5150 perf_output_put(handle
, data
->tid_entry
);
5152 if (sample_type
& PERF_SAMPLE_TIME
)
5153 perf_output_put(handle
, data
->time
);
5155 if (sample_type
& PERF_SAMPLE_ID
)
5156 perf_output_put(handle
, data
->id
);
5158 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5159 perf_output_put(handle
, data
->stream_id
);
5161 if (sample_type
& PERF_SAMPLE_CPU
)
5162 perf_output_put(handle
, data
->cpu_entry
);
5164 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5165 perf_output_put(handle
, data
->id
);
5168 void perf_event__output_id_sample(struct perf_event
*event
,
5169 struct perf_output_handle
*handle
,
5170 struct perf_sample_data
*sample
)
5172 if (event
->attr
.sample_id_all
)
5173 __perf_event__output_id_sample(handle
, sample
);
5176 static void perf_output_read_one(struct perf_output_handle
*handle
,
5177 struct perf_event
*event
,
5178 u64 enabled
, u64 running
)
5180 u64 read_format
= event
->attr
.read_format
;
5184 values
[n
++] = perf_event_count(event
);
5185 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5186 values
[n
++] = enabled
+
5187 atomic64_read(&event
->child_total_time_enabled
);
5189 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5190 values
[n
++] = running
+
5191 atomic64_read(&event
->child_total_time_running
);
5193 if (read_format
& PERF_FORMAT_ID
)
5194 values
[n
++] = primary_event_id(event
);
5196 __output_copy(handle
, values
, n
* sizeof(u64
));
5200 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5202 static void perf_output_read_group(struct perf_output_handle
*handle
,
5203 struct perf_event
*event
,
5204 u64 enabled
, u64 running
)
5206 struct perf_event
*leader
= event
->group_leader
, *sub
;
5207 u64 read_format
= event
->attr
.read_format
;
5211 values
[n
++] = 1 + leader
->nr_siblings
;
5213 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5214 values
[n
++] = enabled
;
5216 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5217 values
[n
++] = running
;
5219 if (leader
!= event
)
5220 leader
->pmu
->read(leader
);
5222 values
[n
++] = perf_event_count(leader
);
5223 if (read_format
& PERF_FORMAT_ID
)
5224 values
[n
++] = primary_event_id(leader
);
5226 __output_copy(handle
, values
, n
* sizeof(u64
));
5228 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5231 if ((sub
!= event
) &&
5232 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5233 sub
->pmu
->read(sub
);
5235 values
[n
++] = perf_event_count(sub
);
5236 if (read_format
& PERF_FORMAT_ID
)
5237 values
[n
++] = primary_event_id(sub
);
5239 __output_copy(handle
, values
, n
* sizeof(u64
));
5243 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5244 PERF_FORMAT_TOTAL_TIME_RUNNING)
5246 static void perf_output_read(struct perf_output_handle
*handle
,
5247 struct perf_event
*event
)
5249 u64 enabled
= 0, running
= 0, now
;
5250 u64 read_format
= event
->attr
.read_format
;
5253 * compute total_time_enabled, total_time_running
5254 * based on snapshot values taken when the event
5255 * was last scheduled in.
5257 * we cannot simply called update_context_time()
5258 * because of locking issue as we are called in
5261 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5262 calc_timer_values(event
, &now
, &enabled
, &running
);
5264 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5265 perf_output_read_group(handle
, event
, enabled
, running
);
5267 perf_output_read_one(handle
, event
, enabled
, running
);
5270 void perf_output_sample(struct perf_output_handle
*handle
,
5271 struct perf_event_header
*header
,
5272 struct perf_sample_data
*data
,
5273 struct perf_event
*event
)
5275 u64 sample_type
= data
->type
;
5277 perf_output_put(handle
, *header
);
5279 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5280 perf_output_put(handle
, data
->id
);
5282 if (sample_type
& PERF_SAMPLE_IP
)
5283 perf_output_put(handle
, data
->ip
);
5285 if (sample_type
& PERF_SAMPLE_TID
)
5286 perf_output_put(handle
, data
->tid_entry
);
5288 if (sample_type
& PERF_SAMPLE_TIME
)
5289 perf_output_put(handle
, data
->time
);
5291 if (sample_type
& PERF_SAMPLE_ADDR
)
5292 perf_output_put(handle
, data
->addr
);
5294 if (sample_type
& PERF_SAMPLE_ID
)
5295 perf_output_put(handle
, data
->id
);
5297 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5298 perf_output_put(handle
, data
->stream_id
);
5300 if (sample_type
& PERF_SAMPLE_CPU
)
5301 perf_output_put(handle
, data
->cpu_entry
);
5303 if (sample_type
& PERF_SAMPLE_PERIOD
)
5304 perf_output_put(handle
, data
->period
);
5306 if (sample_type
& PERF_SAMPLE_READ
)
5307 perf_output_read(handle
, event
);
5309 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5310 if (data
->callchain
) {
5313 if (data
->callchain
)
5314 size
+= data
->callchain
->nr
;
5316 size
*= sizeof(u64
);
5318 __output_copy(handle
, data
->callchain
, size
);
5321 perf_output_put(handle
, nr
);
5325 if (sample_type
& PERF_SAMPLE_RAW
) {
5327 u32 raw_size
= data
->raw
->size
;
5328 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5329 sizeof(u64
)) - sizeof(u32
);
5332 perf_output_put(handle
, real_size
);
5333 __output_copy(handle
, data
->raw
->data
, raw_size
);
5334 if (real_size
- raw_size
)
5335 __output_copy(handle
, &zero
, real_size
- raw_size
);
5341 .size
= sizeof(u32
),
5344 perf_output_put(handle
, raw
);
5348 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5349 if (data
->br_stack
) {
5352 size
= data
->br_stack
->nr
5353 * sizeof(struct perf_branch_entry
);
5355 perf_output_put(handle
, data
->br_stack
->nr
);
5356 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5359 * we always store at least the value of nr
5362 perf_output_put(handle
, nr
);
5366 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5367 u64 abi
= data
->regs_user
.abi
;
5370 * If there are no regs to dump, notice it through
5371 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5373 perf_output_put(handle
, abi
);
5376 u64 mask
= event
->attr
.sample_regs_user
;
5377 perf_output_sample_regs(handle
,
5378 data
->regs_user
.regs
,
5383 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5384 perf_output_sample_ustack(handle
,
5385 data
->stack_user_size
,
5386 data
->regs_user
.regs
);
5389 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5390 perf_output_put(handle
, data
->weight
);
5392 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5393 perf_output_put(handle
, data
->data_src
.val
);
5395 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5396 perf_output_put(handle
, data
->txn
);
5398 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5399 u64 abi
= data
->regs_intr
.abi
;
5401 * If there are no regs to dump, notice it through
5402 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5404 perf_output_put(handle
, abi
);
5407 u64 mask
= event
->attr
.sample_regs_intr
;
5409 perf_output_sample_regs(handle
,
5410 data
->regs_intr
.regs
,
5415 if (!event
->attr
.watermark
) {
5416 int wakeup_events
= event
->attr
.wakeup_events
;
5418 if (wakeup_events
) {
5419 struct ring_buffer
*rb
= handle
->rb
;
5420 int events
= local_inc_return(&rb
->events
);
5422 if (events
>= wakeup_events
) {
5423 local_sub(wakeup_events
, &rb
->events
);
5424 local_inc(&rb
->wakeup
);
5430 void perf_prepare_sample(struct perf_event_header
*header
,
5431 struct perf_sample_data
*data
,
5432 struct perf_event
*event
,
5433 struct pt_regs
*regs
)
5435 u64 sample_type
= event
->attr
.sample_type
;
5437 header
->type
= PERF_RECORD_SAMPLE
;
5438 header
->size
= sizeof(*header
) + event
->header_size
;
5441 header
->misc
|= perf_misc_flags(regs
);
5443 __perf_event_header__init_id(header
, data
, event
);
5445 if (sample_type
& PERF_SAMPLE_IP
)
5446 data
->ip
= perf_instruction_pointer(regs
);
5448 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5451 data
->callchain
= perf_callchain(event
, regs
);
5453 if (data
->callchain
)
5454 size
+= data
->callchain
->nr
;
5456 header
->size
+= size
* sizeof(u64
);
5459 if (sample_type
& PERF_SAMPLE_RAW
) {
5460 int size
= sizeof(u32
);
5463 size
+= data
->raw
->size
;
5465 size
+= sizeof(u32
);
5467 header
->size
+= round_up(size
, sizeof(u64
));
5470 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5471 int size
= sizeof(u64
); /* nr */
5472 if (data
->br_stack
) {
5473 size
+= data
->br_stack
->nr
5474 * sizeof(struct perf_branch_entry
);
5476 header
->size
+= size
;
5479 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5480 perf_sample_regs_user(&data
->regs_user
, regs
,
5481 &data
->regs_user_copy
);
5483 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5484 /* regs dump ABI info */
5485 int size
= sizeof(u64
);
5487 if (data
->regs_user
.regs
) {
5488 u64 mask
= event
->attr
.sample_regs_user
;
5489 size
+= hweight64(mask
) * sizeof(u64
);
5492 header
->size
+= size
;
5495 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5497 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5498 * processed as the last one or have additional check added
5499 * in case new sample type is added, because we could eat
5500 * up the rest of the sample size.
5502 u16 stack_size
= event
->attr
.sample_stack_user
;
5503 u16 size
= sizeof(u64
);
5505 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5506 data
->regs_user
.regs
);
5509 * If there is something to dump, add space for the dump
5510 * itself and for the field that tells the dynamic size,
5511 * which is how many have been actually dumped.
5514 size
+= sizeof(u64
) + stack_size
;
5516 data
->stack_user_size
= stack_size
;
5517 header
->size
+= size
;
5520 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5521 /* regs dump ABI info */
5522 int size
= sizeof(u64
);
5524 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5526 if (data
->regs_intr
.regs
) {
5527 u64 mask
= event
->attr
.sample_regs_intr
;
5529 size
+= hweight64(mask
) * sizeof(u64
);
5532 header
->size
+= size
;
5536 void perf_event_output(struct perf_event
*event
,
5537 struct perf_sample_data
*data
,
5538 struct pt_regs
*regs
)
5540 struct perf_output_handle handle
;
5541 struct perf_event_header header
;
5543 /* protect the callchain buffers */
5546 perf_prepare_sample(&header
, data
, event
, regs
);
5548 if (perf_output_begin(&handle
, event
, header
.size
))
5551 perf_output_sample(&handle
, &header
, data
, event
);
5553 perf_output_end(&handle
);
5563 struct perf_read_event
{
5564 struct perf_event_header header
;
5571 perf_event_read_event(struct perf_event
*event
,
5572 struct task_struct
*task
)
5574 struct perf_output_handle handle
;
5575 struct perf_sample_data sample
;
5576 struct perf_read_event read_event
= {
5578 .type
= PERF_RECORD_READ
,
5580 .size
= sizeof(read_event
) + event
->read_size
,
5582 .pid
= perf_event_pid(event
, task
),
5583 .tid
= perf_event_tid(event
, task
),
5587 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5588 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5592 perf_output_put(&handle
, read_event
);
5593 perf_output_read(&handle
, event
);
5594 perf_event__output_id_sample(event
, &handle
, &sample
);
5596 perf_output_end(&handle
);
5599 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5602 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5603 perf_event_aux_output_cb output
,
5606 struct perf_event
*event
;
5608 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5609 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5611 if (!event_filter_match(event
))
5613 output(event
, data
);
5618 perf_event_aux_task_ctx(perf_event_aux_output_cb output
, void *data
,
5619 struct perf_event_context
*task_ctx
)
5623 perf_event_aux_ctx(task_ctx
, output
, data
);
5629 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5630 struct perf_event_context
*task_ctx
)
5632 struct perf_cpu_context
*cpuctx
;
5633 struct perf_event_context
*ctx
;
5638 * If we have task_ctx != NULL we only notify
5639 * the task context itself. The task_ctx is set
5640 * only for EXIT events before releasing task
5644 perf_event_aux_task_ctx(output
, data
, task_ctx
);
5649 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5650 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5651 if (cpuctx
->unique_pmu
!= pmu
)
5653 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5654 ctxn
= pmu
->task_ctx_nr
;
5657 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5659 perf_event_aux_ctx(ctx
, output
, data
);
5661 put_cpu_ptr(pmu
->pmu_cpu_context
);
5667 * task tracking -- fork/exit
5669 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5672 struct perf_task_event
{
5673 struct task_struct
*task
;
5674 struct perf_event_context
*task_ctx
;
5677 struct perf_event_header header
;
5687 static int perf_event_task_match(struct perf_event
*event
)
5689 return event
->attr
.comm
|| event
->attr
.mmap
||
5690 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5694 static void perf_event_task_output(struct perf_event
*event
,
5697 struct perf_task_event
*task_event
= data
;
5698 struct perf_output_handle handle
;
5699 struct perf_sample_data sample
;
5700 struct task_struct
*task
= task_event
->task
;
5701 int ret
, size
= task_event
->event_id
.header
.size
;
5703 if (!perf_event_task_match(event
))
5706 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5708 ret
= perf_output_begin(&handle
, event
,
5709 task_event
->event_id
.header
.size
);
5713 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5714 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5716 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5717 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5719 task_event
->event_id
.time
= perf_event_clock(event
);
5721 perf_output_put(&handle
, task_event
->event_id
);
5723 perf_event__output_id_sample(event
, &handle
, &sample
);
5725 perf_output_end(&handle
);
5727 task_event
->event_id
.header
.size
= size
;
5730 static void perf_event_task(struct task_struct
*task
,
5731 struct perf_event_context
*task_ctx
,
5734 struct perf_task_event task_event
;
5736 if (!atomic_read(&nr_comm_events
) &&
5737 !atomic_read(&nr_mmap_events
) &&
5738 !atomic_read(&nr_task_events
))
5741 task_event
= (struct perf_task_event
){
5743 .task_ctx
= task_ctx
,
5746 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5748 .size
= sizeof(task_event
.event_id
),
5758 perf_event_aux(perf_event_task_output
,
5763 void perf_event_fork(struct task_struct
*task
)
5765 perf_event_task(task
, NULL
, 1);
5772 struct perf_comm_event
{
5773 struct task_struct
*task
;
5778 struct perf_event_header header
;
5785 static int perf_event_comm_match(struct perf_event
*event
)
5787 return event
->attr
.comm
;
5790 static void perf_event_comm_output(struct perf_event
*event
,
5793 struct perf_comm_event
*comm_event
= data
;
5794 struct perf_output_handle handle
;
5795 struct perf_sample_data sample
;
5796 int size
= comm_event
->event_id
.header
.size
;
5799 if (!perf_event_comm_match(event
))
5802 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5803 ret
= perf_output_begin(&handle
, event
,
5804 comm_event
->event_id
.header
.size
);
5809 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5810 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5812 perf_output_put(&handle
, comm_event
->event_id
);
5813 __output_copy(&handle
, comm_event
->comm
,
5814 comm_event
->comm_size
);
5816 perf_event__output_id_sample(event
, &handle
, &sample
);
5818 perf_output_end(&handle
);
5820 comm_event
->event_id
.header
.size
= size
;
5823 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5825 char comm
[TASK_COMM_LEN
];
5828 memset(comm
, 0, sizeof(comm
));
5829 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5830 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5832 comm_event
->comm
= comm
;
5833 comm_event
->comm_size
= size
;
5835 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5837 perf_event_aux(perf_event_comm_output
,
5842 void perf_event_comm(struct task_struct
*task
, bool exec
)
5844 struct perf_comm_event comm_event
;
5846 if (!atomic_read(&nr_comm_events
))
5849 comm_event
= (struct perf_comm_event
){
5855 .type
= PERF_RECORD_COMM
,
5856 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5864 perf_event_comm_event(&comm_event
);
5871 struct perf_mmap_event
{
5872 struct vm_area_struct
*vma
;
5874 const char *file_name
;
5882 struct perf_event_header header
;
5892 static int perf_event_mmap_match(struct perf_event
*event
,
5895 struct perf_mmap_event
*mmap_event
= data
;
5896 struct vm_area_struct
*vma
= mmap_event
->vma
;
5897 int executable
= vma
->vm_flags
& VM_EXEC
;
5899 return (!executable
&& event
->attr
.mmap_data
) ||
5900 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5903 static void perf_event_mmap_output(struct perf_event
*event
,
5906 struct perf_mmap_event
*mmap_event
= data
;
5907 struct perf_output_handle handle
;
5908 struct perf_sample_data sample
;
5909 int size
= mmap_event
->event_id
.header
.size
;
5912 if (!perf_event_mmap_match(event
, data
))
5915 if (event
->attr
.mmap2
) {
5916 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5917 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5918 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5919 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5920 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5921 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5922 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5925 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5926 ret
= perf_output_begin(&handle
, event
,
5927 mmap_event
->event_id
.header
.size
);
5931 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5932 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5934 perf_output_put(&handle
, mmap_event
->event_id
);
5936 if (event
->attr
.mmap2
) {
5937 perf_output_put(&handle
, mmap_event
->maj
);
5938 perf_output_put(&handle
, mmap_event
->min
);
5939 perf_output_put(&handle
, mmap_event
->ino
);
5940 perf_output_put(&handle
, mmap_event
->ino_generation
);
5941 perf_output_put(&handle
, mmap_event
->prot
);
5942 perf_output_put(&handle
, mmap_event
->flags
);
5945 __output_copy(&handle
, mmap_event
->file_name
,
5946 mmap_event
->file_size
);
5948 perf_event__output_id_sample(event
, &handle
, &sample
);
5950 perf_output_end(&handle
);
5952 mmap_event
->event_id
.header
.size
= size
;
5955 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5957 struct vm_area_struct
*vma
= mmap_event
->vma
;
5958 struct file
*file
= vma
->vm_file
;
5959 int maj
= 0, min
= 0;
5960 u64 ino
= 0, gen
= 0;
5961 u32 prot
= 0, flags
= 0;
5968 struct inode
*inode
;
5971 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5977 * d_path() works from the end of the rb backwards, so we
5978 * need to add enough zero bytes after the string to handle
5979 * the 64bit alignment we do later.
5981 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
5986 inode
= file_inode(vma
->vm_file
);
5987 dev
= inode
->i_sb
->s_dev
;
5989 gen
= inode
->i_generation
;
5993 if (vma
->vm_flags
& VM_READ
)
5995 if (vma
->vm_flags
& VM_WRITE
)
5997 if (vma
->vm_flags
& VM_EXEC
)
6000 if (vma
->vm_flags
& VM_MAYSHARE
)
6003 flags
= MAP_PRIVATE
;
6005 if (vma
->vm_flags
& VM_DENYWRITE
)
6006 flags
|= MAP_DENYWRITE
;
6007 if (vma
->vm_flags
& VM_MAYEXEC
)
6008 flags
|= MAP_EXECUTABLE
;
6009 if (vma
->vm_flags
& VM_LOCKED
)
6010 flags
|= MAP_LOCKED
;
6011 if (vma
->vm_flags
& VM_HUGETLB
)
6012 flags
|= MAP_HUGETLB
;
6016 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6017 name
= (char *) vma
->vm_ops
->name(vma
);
6022 name
= (char *)arch_vma_name(vma
);
6026 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6027 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6031 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6032 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6042 strlcpy(tmp
, name
, sizeof(tmp
));
6046 * Since our buffer works in 8 byte units we need to align our string
6047 * size to a multiple of 8. However, we must guarantee the tail end is
6048 * zero'd out to avoid leaking random bits to userspace.
6050 size
= strlen(name
)+1;
6051 while (!IS_ALIGNED(size
, sizeof(u64
)))
6052 name
[size
++] = '\0';
6054 mmap_event
->file_name
= name
;
6055 mmap_event
->file_size
= size
;
6056 mmap_event
->maj
= maj
;
6057 mmap_event
->min
= min
;
6058 mmap_event
->ino
= ino
;
6059 mmap_event
->ino_generation
= gen
;
6060 mmap_event
->prot
= prot
;
6061 mmap_event
->flags
= flags
;
6063 if (!(vma
->vm_flags
& VM_EXEC
))
6064 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6066 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6068 perf_event_aux(perf_event_mmap_output
,
6075 void perf_event_mmap(struct vm_area_struct
*vma
)
6077 struct perf_mmap_event mmap_event
;
6079 if (!atomic_read(&nr_mmap_events
))
6082 mmap_event
= (struct perf_mmap_event
){
6088 .type
= PERF_RECORD_MMAP
,
6089 .misc
= PERF_RECORD_MISC_USER
,
6094 .start
= vma
->vm_start
,
6095 .len
= vma
->vm_end
- vma
->vm_start
,
6096 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6098 /* .maj (attr_mmap2 only) */
6099 /* .min (attr_mmap2 only) */
6100 /* .ino (attr_mmap2 only) */
6101 /* .ino_generation (attr_mmap2 only) */
6102 /* .prot (attr_mmap2 only) */
6103 /* .flags (attr_mmap2 only) */
6106 perf_event_mmap_event(&mmap_event
);
6109 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6110 unsigned long size
, u64 flags
)
6112 struct perf_output_handle handle
;
6113 struct perf_sample_data sample
;
6114 struct perf_aux_event
{
6115 struct perf_event_header header
;
6121 .type
= PERF_RECORD_AUX
,
6123 .size
= sizeof(rec
),
6131 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6132 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6137 perf_output_put(&handle
, rec
);
6138 perf_event__output_id_sample(event
, &handle
, &sample
);
6140 perf_output_end(&handle
);
6144 * Lost/dropped samples logging
6146 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6148 struct perf_output_handle handle
;
6149 struct perf_sample_data sample
;
6153 struct perf_event_header header
;
6155 } lost_samples_event
= {
6157 .type
= PERF_RECORD_LOST_SAMPLES
,
6159 .size
= sizeof(lost_samples_event
),
6164 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6166 ret
= perf_output_begin(&handle
, event
,
6167 lost_samples_event
.header
.size
);
6171 perf_output_put(&handle
, lost_samples_event
);
6172 perf_event__output_id_sample(event
, &handle
, &sample
);
6173 perf_output_end(&handle
);
6177 * context_switch tracking
6180 struct perf_switch_event
{
6181 struct task_struct
*task
;
6182 struct task_struct
*next_prev
;
6185 struct perf_event_header header
;
6191 static int perf_event_switch_match(struct perf_event
*event
)
6193 return event
->attr
.context_switch
;
6196 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6198 struct perf_switch_event
*se
= data
;
6199 struct perf_output_handle handle
;
6200 struct perf_sample_data sample
;
6203 if (!perf_event_switch_match(event
))
6206 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6207 if (event
->ctx
->task
) {
6208 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6209 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6211 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6212 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6213 se
->event_id
.next_prev_pid
=
6214 perf_event_pid(event
, se
->next_prev
);
6215 se
->event_id
.next_prev_tid
=
6216 perf_event_tid(event
, se
->next_prev
);
6219 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6221 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6225 if (event
->ctx
->task
)
6226 perf_output_put(&handle
, se
->event_id
.header
);
6228 perf_output_put(&handle
, se
->event_id
);
6230 perf_event__output_id_sample(event
, &handle
, &sample
);
6232 perf_output_end(&handle
);
6235 static void perf_event_switch(struct task_struct
*task
,
6236 struct task_struct
*next_prev
, bool sched_in
)
6238 struct perf_switch_event switch_event
;
6240 /* N.B. caller checks nr_switch_events != 0 */
6242 switch_event
= (struct perf_switch_event
){
6244 .next_prev
= next_prev
,
6248 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6251 /* .next_prev_pid */
6252 /* .next_prev_tid */
6256 perf_event_aux(perf_event_switch_output
,
6262 * IRQ throttle logging
6265 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6267 struct perf_output_handle handle
;
6268 struct perf_sample_data sample
;
6272 struct perf_event_header header
;
6276 } throttle_event
= {
6278 .type
= PERF_RECORD_THROTTLE
,
6280 .size
= sizeof(throttle_event
),
6282 .time
= perf_event_clock(event
),
6283 .id
= primary_event_id(event
),
6284 .stream_id
= event
->id
,
6288 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6290 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6292 ret
= perf_output_begin(&handle
, event
,
6293 throttle_event
.header
.size
);
6297 perf_output_put(&handle
, throttle_event
);
6298 perf_event__output_id_sample(event
, &handle
, &sample
);
6299 perf_output_end(&handle
);
6302 static void perf_log_itrace_start(struct perf_event
*event
)
6304 struct perf_output_handle handle
;
6305 struct perf_sample_data sample
;
6306 struct perf_aux_event
{
6307 struct perf_event_header header
;
6314 event
= event
->parent
;
6316 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6317 event
->hw
.itrace_started
)
6320 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6321 rec
.header
.misc
= 0;
6322 rec
.header
.size
= sizeof(rec
);
6323 rec
.pid
= perf_event_pid(event
, current
);
6324 rec
.tid
= perf_event_tid(event
, current
);
6326 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6327 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6332 perf_output_put(&handle
, rec
);
6333 perf_event__output_id_sample(event
, &handle
, &sample
);
6335 perf_output_end(&handle
);
6339 * Generic event overflow handling, sampling.
6342 static int __perf_event_overflow(struct perf_event
*event
,
6343 int throttle
, struct perf_sample_data
*data
,
6344 struct pt_regs
*regs
)
6346 int events
= atomic_read(&event
->event_limit
);
6347 struct hw_perf_event
*hwc
= &event
->hw
;
6352 * Non-sampling counters might still use the PMI to fold short
6353 * hardware counters, ignore those.
6355 if (unlikely(!is_sampling_event(event
)))
6358 seq
= __this_cpu_read(perf_throttled_seq
);
6359 if (seq
!= hwc
->interrupts_seq
) {
6360 hwc
->interrupts_seq
= seq
;
6361 hwc
->interrupts
= 1;
6364 if (unlikely(throttle
6365 && hwc
->interrupts
>= max_samples_per_tick
)) {
6366 __this_cpu_inc(perf_throttled_count
);
6367 hwc
->interrupts
= MAX_INTERRUPTS
;
6368 perf_log_throttle(event
, 0);
6369 tick_nohz_full_kick();
6374 if (event
->attr
.freq
) {
6375 u64 now
= perf_clock();
6376 s64 delta
= now
- hwc
->freq_time_stamp
;
6378 hwc
->freq_time_stamp
= now
;
6380 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6381 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6385 * XXX event_limit might not quite work as expected on inherited
6389 event
->pending_kill
= POLL_IN
;
6390 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6392 event
->pending_kill
= POLL_HUP
;
6393 event
->pending_disable
= 1;
6394 irq_work_queue(&event
->pending
);
6397 if (event
->overflow_handler
)
6398 event
->overflow_handler(event
, data
, regs
);
6400 perf_event_output(event
, data
, regs
);
6402 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6403 event
->pending_wakeup
= 1;
6404 irq_work_queue(&event
->pending
);
6410 int perf_event_overflow(struct perf_event
*event
,
6411 struct perf_sample_data
*data
,
6412 struct pt_regs
*regs
)
6414 return __perf_event_overflow(event
, 1, data
, regs
);
6418 * Generic software event infrastructure
6421 struct swevent_htable
{
6422 struct swevent_hlist
*swevent_hlist
;
6423 struct mutex hlist_mutex
;
6426 /* Recursion avoidance in each contexts */
6427 int recursion
[PERF_NR_CONTEXTS
];
6430 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6433 * We directly increment event->count and keep a second value in
6434 * event->hw.period_left to count intervals. This period event
6435 * is kept in the range [-sample_period, 0] so that we can use the
6439 u64
perf_swevent_set_period(struct perf_event
*event
)
6441 struct hw_perf_event
*hwc
= &event
->hw
;
6442 u64 period
= hwc
->last_period
;
6446 hwc
->last_period
= hwc
->sample_period
;
6449 old
= val
= local64_read(&hwc
->period_left
);
6453 nr
= div64_u64(period
+ val
, period
);
6454 offset
= nr
* period
;
6456 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6462 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6463 struct perf_sample_data
*data
,
6464 struct pt_regs
*regs
)
6466 struct hw_perf_event
*hwc
= &event
->hw
;
6470 overflow
= perf_swevent_set_period(event
);
6472 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6475 for (; overflow
; overflow
--) {
6476 if (__perf_event_overflow(event
, throttle
,
6479 * We inhibit the overflow from happening when
6480 * hwc->interrupts == MAX_INTERRUPTS.
6488 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6489 struct perf_sample_data
*data
,
6490 struct pt_regs
*regs
)
6492 struct hw_perf_event
*hwc
= &event
->hw
;
6494 local64_add(nr
, &event
->count
);
6499 if (!is_sampling_event(event
))
6502 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6504 return perf_swevent_overflow(event
, 1, data
, regs
);
6506 data
->period
= event
->hw
.last_period
;
6508 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6509 return perf_swevent_overflow(event
, 1, data
, regs
);
6511 if (local64_add_negative(nr
, &hwc
->period_left
))
6514 perf_swevent_overflow(event
, 0, data
, regs
);
6517 static int perf_exclude_event(struct perf_event
*event
,
6518 struct pt_regs
*regs
)
6520 if (event
->hw
.state
& PERF_HES_STOPPED
)
6524 if (event
->attr
.exclude_user
&& user_mode(regs
))
6527 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6534 static int perf_swevent_match(struct perf_event
*event
,
6535 enum perf_type_id type
,
6537 struct perf_sample_data
*data
,
6538 struct pt_regs
*regs
)
6540 if (event
->attr
.type
!= type
)
6543 if (event
->attr
.config
!= event_id
)
6546 if (perf_exclude_event(event
, regs
))
6552 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6554 u64 val
= event_id
| (type
<< 32);
6556 return hash_64(val
, SWEVENT_HLIST_BITS
);
6559 static inline struct hlist_head
*
6560 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6562 u64 hash
= swevent_hash(type
, event_id
);
6564 return &hlist
->heads
[hash
];
6567 /* For the read side: events when they trigger */
6568 static inline struct hlist_head
*
6569 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6571 struct swevent_hlist
*hlist
;
6573 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6577 return __find_swevent_head(hlist
, type
, event_id
);
6580 /* For the event head insertion and removal in the hlist */
6581 static inline struct hlist_head
*
6582 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6584 struct swevent_hlist
*hlist
;
6585 u32 event_id
= event
->attr
.config
;
6586 u64 type
= event
->attr
.type
;
6589 * Event scheduling is always serialized against hlist allocation
6590 * and release. Which makes the protected version suitable here.
6591 * The context lock guarantees that.
6593 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6594 lockdep_is_held(&event
->ctx
->lock
));
6598 return __find_swevent_head(hlist
, type
, event_id
);
6601 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6603 struct perf_sample_data
*data
,
6604 struct pt_regs
*regs
)
6606 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6607 struct perf_event
*event
;
6608 struct hlist_head
*head
;
6611 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6615 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6616 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6617 perf_swevent_event(event
, nr
, data
, regs
);
6623 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6625 int perf_swevent_get_recursion_context(void)
6627 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6629 return get_recursion_context(swhash
->recursion
);
6631 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6633 inline void perf_swevent_put_recursion_context(int rctx
)
6635 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6637 put_recursion_context(swhash
->recursion
, rctx
);
6640 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6642 struct perf_sample_data data
;
6644 if (WARN_ON_ONCE(!regs
))
6647 perf_sample_data_init(&data
, addr
, 0);
6648 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6651 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6655 preempt_disable_notrace();
6656 rctx
= perf_swevent_get_recursion_context();
6657 if (unlikely(rctx
< 0))
6660 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6662 perf_swevent_put_recursion_context(rctx
);
6664 preempt_enable_notrace();
6667 static void perf_swevent_read(struct perf_event
*event
)
6671 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6673 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6674 struct hw_perf_event
*hwc
= &event
->hw
;
6675 struct hlist_head
*head
;
6677 if (is_sampling_event(event
)) {
6678 hwc
->last_period
= hwc
->sample_period
;
6679 perf_swevent_set_period(event
);
6682 hwc
->state
= !(flags
& PERF_EF_START
);
6684 head
= find_swevent_head(swhash
, event
);
6685 if (WARN_ON_ONCE(!head
))
6688 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6689 perf_event_update_userpage(event
);
6694 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6696 hlist_del_rcu(&event
->hlist_entry
);
6699 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6701 event
->hw
.state
= 0;
6704 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6706 event
->hw
.state
= PERF_HES_STOPPED
;
6709 /* Deref the hlist from the update side */
6710 static inline struct swevent_hlist
*
6711 swevent_hlist_deref(struct swevent_htable
*swhash
)
6713 return rcu_dereference_protected(swhash
->swevent_hlist
,
6714 lockdep_is_held(&swhash
->hlist_mutex
));
6717 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6719 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6724 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6725 kfree_rcu(hlist
, rcu_head
);
6728 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6730 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6732 mutex_lock(&swhash
->hlist_mutex
);
6734 if (!--swhash
->hlist_refcount
)
6735 swevent_hlist_release(swhash
);
6737 mutex_unlock(&swhash
->hlist_mutex
);
6740 static void swevent_hlist_put(struct perf_event
*event
)
6744 for_each_possible_cpu(cpu
)
6745 swevent_hlist_put_cpu(event
, cpu
);
6748 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6750 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6753 mutex_lock(&swhash
->hlist_mutex
);
6754 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6755 struct swevent_hlist
*hlist
;
6757 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6762 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6764 swhash
->hlist_refcount
++;
6766 mutex_unlock(&swhash
->hlist_mutex
);
6771 static int swevent_hlist_get(struct perf_event
*event
)
6774 int cpu
, failed_cpu
;
6777 for_each_possible_cpu(cpu
) {
6778 err
= swevent_hlist_get_cpu(event
, cpu
);
6788 for_each_possible_cpu(cpu
) {
6789 if (cpu
== failed_cpu
)
6791 swevent_hlist_put_cpu(event
, cpu
);
6798 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6800 static void sw_perf_event_destroy(struct perf_event
*event
)
6802 u64 event_id
= event
->attr
.config
;
6804 WARN_ON(event
->parent
);
6806 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6807 swevent_hlist_put(event
);
6810 static int perf_swevent_init(struct perf_event
*event
)
6812 u64 event_id
= event
->attr
.config
;
6814 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6818 * no branch sampling for software events
6820 if (has_branch_stack(event
))
6824 case PERF_COUNT_SW_CPU_CLOCK
:
6825 case PERF_COUNT_SW_TASK_CLOCK
:
6832 if (event_id
>= PERF_COUNT_SW_MAX
)
6835 if (!event
->parent
) {
6838 err
= swevent_hlist_get(event
);
6842 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6843 event
->destroy
= sw_perf_event_destroy
;
6849 static struct pmu perf_swevent
= {
6850 .task_ctx_nr
= perf_sw_context
,
6852 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6854 .event_init
= perf_swevent_init
,
6855 .add
= perf_swevent_add
,
6856 .del
= perf_swevent_del
,
6857 .start
= perf_swevent_start
,
6858 .stop
= perf_swevent_stop
,
6859 .read
= perf_swevent_read
,
6862 #ifdef CONFIG_EVENT_TRACING
6864 static int perf_tp_filter_match(struct perf_event
*event
,
6865 struct perf_sample_data
*data
)
6867 void *record
= data
->raw
->data
;
6869 /* only top level events have filters set */
6871 event
= event
->parent
;
6873 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6878 static int perf_tp_event_match(struct perf_event
*event
,
6879 struct perf_sample_data
*data
,
6880 struct pt_regs
*regs
)
6882 if (event
->hw
.state
& PERF_HES_STOPPED
)
6885 * All tracepoints are from kernel-space.
6887 if (event
->attr
.exclude_kernel
)
6890 if (!perf_tp_filter_match(event
, data
))
6896 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6897 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6898 struct task_struct
*task
)
6900 struct perf_sample_data data
;
6901 struct perf_event
*event
;
6903 struct perf_raw_record raw
= {
6908 perf_sample_data_init(&data
, addr
, 0);
6911 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6912 if (perf_tp_event_match(event
, &data
, regs
))
6913 perf_swevent_event(event
, count
, &data
, regs
);
6917 * If we got specified a target task, also iterate its context and
6918 * deliver this event there too.
6920 if (task
&& task
!= current
) {
6921 struct perf_event_context
*ctx
;
6922 struct trace_entry
*entry
= record
;
6925 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6929 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6930 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6932 if (event
->attr
.config
!= entry
->type
)
6934 if (perf_tp_event_match(event
, &data
, regs
))
6935 perf_swevent_event(event
, count
, &data
, regs
);
6941 perf_swevent_put_recursion_context(rctx
);
6943 EXPORT_SYMBOL_GPL(perf_tp_event
);
6945 static void tp_perf_event_destroy(struct perf_event
*event
)
6947 perf_trace_destroy(event
);
6950 static int perf_tp_event_init(struct perf_event
*event
)
6954 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6958 * no branch sampling for tracepoint events
6960 if (has_branch_stack(event
))
6963 err
= perf_trace_init(event
);
6967 event
->destroy
= tp_perf_event_destroy
;
6972 static struct pmu perf_tracepoint
= {
6973 .task_ctx_nr
= perf_sw_context
,
6975 .event_init
= perf_tp_event_init
,
6976 .add
= perf_trace_add
,
6977 .del
= perf_trace_del
,
6978 .start
= perf_swevent_start
,
6979 .stop
= perf_swevent_stop
,
6980 .read
= perf_swevent_read
,
6983 static inline void perf_tp_register(void)
6985 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
6988 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6993 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6996 filter_str
= strndup_user(arg
, PAGE_SIZE
);
6997 if (IS_ERR(filter_str
))
6998 return PTR_ERR(filter_str
);
7000 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
7006 static void perf_event_free_filter(struct perf_event
*event
)
7008 ftrace_profile_free_filter(event
);
7011 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7013 struct bpf_prog
*prog
;
7015 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7018 if (event
->tp_event
->prog
)
7021 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
7022 /* bpf programs can only be attached to u/kprobes */
7025 prog
= bpf_prog_get(prog_fd
);
7027 return PTR_ERR(prog
);
7029 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7030 /* valid fd, but invalid bpf program type */
7035 event
->tp_event
->prog
= prog
;
7040 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7042 struct bpf_prog
*prog
;
7044 if (!event
->tp_event
)
7047 prog
= event
->tp_event
->prog
;
7049 event
->tp_event
->prog
= NULL
;
7056 static inline void perf_tp_register(void)
7060 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7065 static void perf_event_free_filter(struct perf_event
*event
)
7069 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7074 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7077 #endif /* CONFIG_EVENT_TRACING */
7079 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7080 void perf_bp_event(struct perf_event
*bp
, void *data
)
7082 struct perf_sample_data sample
;
7083 struct pt_regs
*regs
= data
;
7085 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7087 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7088 perf_swevent_event(bp
, 1, &sample
, regs
);
7093 * hrtimer based swevent callback
7096 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7098 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7099 struct perf_sample_data data
;
7100 struct pt_regs
*regs
;
7101 struct perf_event
*event
;
7104 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7106 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7107 return HRTIMER_NORESTART
;
7109 event
->pmu
->read(event
);
7111 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7112 regs
= get_irq_regs();
7114 if (regs
&& !perf_exclude_event(event
, regs
)) {
7115 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7116 if (__perf_event_overflow(event
, 1, &data
, regs
))
7117 ret
= HRTIMER_NORESTART
;
7120 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7121 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7126 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7128 struct hw_perf_event
*hwc
= &event
->hw
;
7131 if (!is_sampling_event(event
))
7134 period
= local64_read(&hwc
->period_left
);
7139 local64_set(&hwc
->period_left
, 0);
7141 period
= max_t(u64
, 10000, hwc
->sample_period
);
7143 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7144 HRTIMER_MODE_REL_PINNED
);
7147 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7149 struct hw_perf_event
*hwc
= &event
->hw
;
7151 if (is_sampling_event(event
)) {
7152 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7153 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7155 hrtimer_cancel(&hwc
->hrtimer
);
7159 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7161 struct hw_perf_event
*hwc
= &event
->hw
;
7163 if (!is_sampling_event(event
))
7166 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7167 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7170 * Since hrtimers have a fixed rate, we can do a static freq->period
7171 * mapping and avoid the whole period adjust feedback stuff.
7173 if (event
->attr
.freq
) {
7174 long freq
= event
->attr
.sample_freq
;
7176 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7177 hwc
->sample_period
= event
->attr
.sample_period
;
7178 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7179 hwc
->last_period
= hwc
->sample_period
;
7180 event
->attr
.freq
= 0;
7185 * Software event: cpu wall time clock
7188 static void cpu_clock_event_update(struct perf_event
*event
)
7193 now
= local_clock();
7194 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7195 local64_add(now
- prev
, &event
->count
);
7198 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7200 local64_set(&event
->hw
.prev_count
, local_clock());
7201 perf_swevent_start_hrtimer(event
);
7204 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7206 perf_swevent_cancel_hrtimer(event
);
7207 cpu_clock_event_update(event
);
7210 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7212 if (flags
& PERF_EF_START
)
7213 cpu_clock_event_start(event
, flags
);
7214 perf_event_update_userpage(event
);
7219 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7221 cpu_clock_event_stop(event
, flags
);
7224 static void cpu_clock_event_read(struct perf_event
*event
)
7226 cpu_clock_event_update(event
);
7229 static int cpu_clock_event_init(struct perf_event
*event
)
7231 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7234 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7238 * no branch sampling for software events
7240 if (has_branch_stack(event
))
7243 perf_swevent_init_hrtimer(event
);
7248 static struct pmu perf_cpu_clock
= {
7249 .task_ctx_nr
= perf_sw_context
,
7251 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7253 .event_init
= cpu_clock_event_init
,
7254 .add
= cpu_clock_event_add
,
7255 .del
= cpu_clock_event_del
,
7256 .start
= cpu_clock_event_start
,
7257 .stop
= cpu_clock_event_stop
,
7258 .read
= cpu_clock_event_read
,
7262 * Software event: task time clock
7265 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7270 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7272 local64_add(delta
, &event
->count
);
7275 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7277 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7278 perf_swevent_start_hrtimer(event
);
7281 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7283 perf_swevent_cancel_hrtimer(event
);
7284 task_clock_event_update(event
, event
->ctx
->time
);
7287 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7289 if (flags
& PERF_EF_START
)
7290 task_clock_event_start(event
, flags
);
7291 perf_event_update_userpage(event
);
7296 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7298 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7301 static void task_clock_event_read(struct perf_event
*event
)
7303 u64 now
= perf_clock();
7304 u64 delta
= now
- event
->ctx
->timestamp
;
7305 u64 time
= event
->ctx
->time
+ delta
;
7307 task_clock_event_update(event
, time
);
7310 static int task_clock_event_init(struct perf_event
*event
)
7312 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7315 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7319 * no branch sampling for software events
7321 if (has_branch_stack(event
))
7324 perf_swevent_init_hrtimer(event
);
7329 static struct pmu perf_task_clock
= {
7330 .task_ctx_nr
= perf_sw_context
,
7332 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7334 .event_init
= task_clock_event_init
,
7335 .add
= task_clock_event_add
,
7336 .del
= task_clock_event_del
,
7337 .start
= task_clock_event_start
,
7338 .stop
= task_clock_event_stop
,
7339 .read
= task_clock_event_read
,
7342 static void perf_pmu_nop_void(struct pmu
*pmu
)
7346 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7350 static int perf_pmu_nop_int(struct pmu
*pmu
)
7355 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7357 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7359 __this_cpu_write(nop_txn_flags
, flags
);
7361 if (flags
& ~PERF_PMU_TXN_ADD
)
7364 perf_pmu_disable(pmu
);
7367 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7369 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7371 __this_cpu_write(nop_txn_flags
, 0);
7373 if (flags
& ~PERF_PMU_TXN_ADD
)
7376 perf_pmu_enable(pmu
);
7380 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7382 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7384 __this_cpu_write(nop_txn_flags
, 0);
7386 if (flags
& ~PERF_PMU_TXN_ADD
)
7389 perf_pmu_enable(pmu
);
7392 static int perf_event_idx_default(struct perf_event
*event
)
7398 * Ensures all contexts with the same task_ctx_nr have the same
7399 * pmu_cpu_context too.
7401 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7408 list_for_each_entry(pmu
, &pmus
, entry
) {
7409 if (pmu
->task_ctx_nr
== ctxn
)
7410 return pmu
->pmu_cpu_context
;
7416 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7420 for_each_possible_cpu(cpu
) {
7421 struct perf_cpu_context
*cpuctx
;
7423 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7425 if (cpuctx
->unique_pmu
== old_pmu
)
7426 cpuctx
->unique_pmu
= pmu
;
7430 static void free_pmu_context(struct pmu
*pmu
)
7434 mutex_lock(&pmus_lock
);
7436 * Like a real lame refcount.
7438 list_for_each_entry(i
, &pmus
, entry
) {
7439 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7440 update_pmu_context(i
, pmu
);
7445 free_percpu(pmu
->pmu_cpu_context
);
7447 mutex_unlock(&pmus_lock
);
7449 static struct idr pmu_idr
;
7452 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7454 struct pmu
*pmu
= dev_get_drvdata(dev
);
7456 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7458 static DEVICE_ATTR_RO(type
);
7461 perf_event_mux_interval_ms_show(struct device
*dev
,
7462 struct device_attribute
*attr
,
7465 struct pmu
*pmu
= dev_get_drvdata(dev
);
7467 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7470 static DEFINE_MUTEX(mux_interval_mutex
);
7473 perf_event_mux_interval_ms_store(struct device
*dev
,
7474 struct device_attribute
*attr
,
7475 const char *buf
, size_t count
)
7477 struct pmu
*pmu
= dev_get_drvdata(dev
);
7478 int timer
, cpu
, ret
;
7480 ret
= kstrtoint(buf
, 0, &timer
);
7487 /* same value, noting to do */
7488 if (timer
== pmu
->hrtimer_interval_ms
)
7491 mutex_lock(&mux_interval_mutex
);
7492 pmu
->hrtimer_interval_ms
= timer
;
7494 /* update all cpuctx for this PMU */
7496 for_each_online_cpu(cpu
) {
7497 struct perf_cpu_context
*cpuctx
;
7498 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7499 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7501 cpu_function_call(cpu
,
7502 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7505 mutex_unlock(&mux_interval_mutex
);
7509 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7511 static struct attribute
*pmu_dev_attrs
[] = {
7512 &dev_attr_type
.attr
,
7513 &dev_attr_perf_event_mux_interval_ms
.attr
,
7516 ATTRIBUTE_GROUPS(pmu_dev
);
7518 static int pmu_bus_running
;
7519 static struct bus_type pmu_bus
= {
7520 .name
= "event_source",
7521 .dev_groups
= pmu_dev_groups
,
7524 static void pmu_dev_release(struct device
*dev
)
7529 static int pmu_dev_alloc(struct pmu
*pmu
)
7533 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7537 pmu
->dev
->groups
= pmu
->attr_groups
;
7538 device_initialize(pmu
->dev
);
7539 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7543 dev_set_drvdata(pmu
->dev
, pmu
);
7544 pmu
->dev
->bus
= &pmu_bus
;
7545 pmu
->dev
->release
= pmu_dev_release
;
7546 ret
= device_add(pmu
->dev
);
7554 put_device(pmu
->dev
);
7558 static struct lock_class_key cpuctx_mutex
;
7559 static struct lock_class_key cpuctx_lock
;
7561 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7565 mutex_lock(&pmus_lock
);
7567 pmu
->pmu_disable_count
= alloc_percpu(int);
7568 if (!pmu
->pmu_disable_count
)
7577 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7585 if (pmu_bus_running
) {
7586 ret
= pmu_dev_alloc(pmu
);
7592 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7593 if (pmu
->pmu_cpu_context
)
7594 goto got_cpu_context
;
7597 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7598 if (!pmu
->pmu_cpu_context
)
7601 for_each_possible_cpu(cpu
) {
7602 struct perf_cpu_context
*cpuctx
;
7604 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7605 __perf_event_init_context(&cpuctx
->ctx
);
7606 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7607 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7608 cpuctx
->ctx
.pmu
= pmu
;
7610 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7612 cpuctx
->unique_pmu
= pmu
;
7616 if (!pmu
->start_txn
) {
7617 if (pmu
->pmu_enable
) {
7619 * If we have pmu_enable/pmu_disable calls, install
7620 * transaction stubs that use that to try and batch
7621 * hardware accesses.
7623 pmu
->start_txn
= perf_pmu_start_txn
;
7624 pmu
->commit_txn
= perf_pmu_commit_txn
;
7625 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7627 pmu
->start_txn
= perf_pmu_nop_txn
;
7628 pmu
->commit_txn
= perf_pmu_nop_int
;
7629 pmu
->cancel_txn
= perf_pmu_nop_void
;
7633 if (!pmu
->pmu_enable
) {
7634 pmu
->pmu_enable
= perf_pmu_nop_void
;
7635 pmu
->pmu_disable
= perf_pmu_nop_void
;
7638 if (!pmu
->event_idx
)
7639 pmu
->event_idx
= perf_event_idx_default
;
7641 list_add_rcu(&pmu
->entry
, &pmus
);
7642 atomic_set(&pmu
->exclusive_cnt
, 0);
7645 mutex_unlock(&pmus_lock
);
7650 device_del(pmu
->dev
);
7651 put_device(pmu
->dev
);
7654 if (pmu
->type
>= PERF_TYPE_MAX
)
7655 idr_remove(&pmu_idr
, pmu
->type
);
7658 free_percpu(pmu
->pmu_disable_count
);
7661 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7663 void perf_pmu_unregister(struct pmu
*pmu
)
7665 mutex_lock(&pmus_lock
);
7666 list_del_rcu(&pmu
->entry
);
7667 mutex_unlock(&pmus_lock
);
7670 * We dereference the pmu list under both SRCU and regular RCU, so
7671 * synchronize against both of those.
7673 synchronize_srcu(&pmus_srcu
);
7676 free_percpu(pmu
->pmu_disable_count
);
7677 if (pmu
->type
>= PERF_TYPE_MAX
)
7678 idr_remove(&pmu_idr
, pmu
->type
);
7679 device_del(pmu
->dev
);
7680 put_device(pmu
->dev
);
7681 free_pmu_context(pmu
);
7683 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7685 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7687 struct perf_event_context
*ctx
= NULL
;
7690 if (!try_module_get(pmu
->module
))
7693 if (event
->group_leader
!= event
) {
7695 * This ctx->mutex can nest when we're called through
7696 * inheritance. See the perf_event_ctx_lock_nested() comment.
7698 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7699 SINGLE_DEPTH_NESTING
);
7704 ret
= pmu
->event_init(event
);
7707 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7710 module_put(pmu
->module
);
7715 static struct pmu
*perf_init_event(struct perf_event
*event
)
7717 struct pmu
*pmu
= NULL
;
7721 idx
= srcu_read_lock(&pmus_srcu
);
7724 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7727 ret
= perf_try_init_event(pmu
, event
);
7733 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7734 ret
= perf_try_init_event(pmu
, event
);
7738 if (ret
!= -ENOENT
) {
7743 pmu
= ERR_PTR(-ENOENT
);
7745 srcu_read_unlock(&pmus_srcu
, idx
);
7750 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7755 if (is_cgroup_event(event
))
7756 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7759 static void account_event(struct perf_event
*event
)
7766 if (event
->attach_state
& PERF_ATTACH_TASK
)
7768 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7769 atomic_inc(&nr_mmap_events
);
7770 if (event
->attr
.comm
)
7771 atomic_inc(&nr_comm_events
);
7772 if (event
->attr
.task
)
7773 atomic_inc(&nr_task_events
);
7774 if (event
->attr
.freq
) {
7775 if (atomic_inc_return(&nr_freq_events
) == 1)
7776 tick_nohz_full_kick_all();
7778 if (event
->attr
.context_switch
) {
7779 atomic_inc(&nr_switch_events
);
7782 if (has_branch_stack(event
))
7784 if (is_cgroup_event(event
))
7788 static_key_slow_inc(&perf_sched_events
.key
);
7790 account_event_cpu(event
, event
->cpu
);
7794 * Allocate and initialize a event structure
7796 static struct perf_event
*
7797 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7798 struct task_struct
*task
,
7799 struct perf_event
*group_leader
,
7800 struct perf_event
*parent_event
,
7801 perf_overflow_handler_t overflow_handler
,
7802 void *context
, int cgroup_fd
)
7805 struct perf_event
*event
;
7806 struct hw_perf_event
*hwc
;
7809 if ((unsigned)cpu
>= nr_cpu_ids
) {
7810 if (!task
|| cpu
!= -1)
7811 return ERR_PTR(-EINVAL
);
7814 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7816 return ERR_PTR(-ENOMEM
);
7819 * Single events are their own group leaders, with an
7820 * empty sibling list:
7823 group_leader
= event
;
7825 mutex_init(&event
->child_mutex
);
7826 INIT_LIST_HEAD(&event
->child_list
);
7828 INIT_LIST_HEAD(&event
->group_entry
);
7829 INIT_LIST_HEAD(&event
->event_entry
);
7830 INIT_LIST_HEAD(&event
->sibling_list
);
7831 INIT_LIST_HEAD(&event
->rb_entry
);
7832 INIT_LIST_HEAD(&event
->active_entry
);
7833 INIT_HLIST_NODE(&event
->hlist_entry
);
7836 init_waitqueue_head(&event
->waitq
);
7837 init_irq_work(&event
->pending
, perf_pending_event
);
7839 mutex_init(&event
->mmap_mutex
);
7841 atomic_long_set(&event
->refcount
, 1);
7843 event
->attr
= *attr
;
7844 event
->group_leader
= group_leader
;
7848 event
->parent
= parent_event
;
7850 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7851 event
->id
= atomic64_inc_return(&perf_event_id
);
7853 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7856 event
->attach_state
= PERF_ATTACH_TASK
;
7858 * XXX pmu::event_init needs to know what task to account to
7859 * and we cannot use the ctx information because we need the
7860 * pmu before we get a ctx.
7862 event
->hw
.target
= task
;
7865 event
->clock
= &local_clock
;
7867 event
->clock
= parent_event
->clock
;
7869 if (!overflow_handler
&& parent_event
) {
7870 overflow_handler
= parent_event
->overflow_handler
;
7871 context
= parent_event
->overflow_handler_context
;
7874 event
->overflow_handler
= overflow_handler
;
7875 event
->overflow_handler_context
= context
;
7877 perf_event__state_init(event
);
7882 hwc
->sample_period
= attr
->sample_period
;
7883 if (attr
->freq
&& attr
->sample_freq
)
7884 hwc
->sample_period
= 1;
7885 hwc
->last_period
= hwc
->sample_period
;
7887 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7890 * we currently do not support PERF_FORMAT_GROUP on inherited events
7892 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7895 if (!has_branch_stack(event
))
7896 event
->attr
.branch_sample_type
= 0;
7898 if (cgroup_fd
!= -1) {
7899 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7904 pmu
= perf_init_event(event
);
7907 else if (IS_ERR(pmu
)) {
7912 err
= exclusive_event_init(event
);
7916 if (!event
->parent
) {
7917 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7918 err
= get_callchain_buffers();
7927 exclusive_event_destroy(event
);
7931 event
->destroy(event
);
7932 module_put(pmu
->module
);
7934 if (is_cgroup_event(event
))
7935 perf_detach_cgroup(event
);
7937 put_pid_ns(event
->ns
);
7940 return ERR_PTR(err
);
7943 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
7944 struct perf_event_attr
*attr
)
7949 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
7953 * zero the full structure, so that a short copy will be nice.
7955 memset(attr
, 0, sizeof(*attr
));
7957 ret
= get_user(size
, &uattr
->size
);
7961 if (size
> PAGE_SIZE
) /* silly large */
7964 if (!size
) /* abi compat */
7965 size
= PERF_ATTR_SIZE_VER0
;
7967 if (size
< PERF_ATTR_SIZE_VER0
)
7971 * If we're handed a bigger struct than we know of,
7972 * ensure all the unknown bits are 0 - i.e. new
7973 * user-space does not rely on any kernel feature
7974 * extensions we dont know about yet.
7976 if (size
> sizeof(*attr
)) {
7977 unsigned char __user
*addr
;
7978 unsigned char __user
*end
;
7981 addr
= (void __user
*)uattr
+ sizeof(*attr
);
7982 end
= (void __user
*)uattr
+ size
;
7984 for (; addr
< end
; addr
++) {
7985 ret
= get_user(val
, addr
);
7991 size
= sizeof(*attr
);
7994 ret
= copy_from_user(attr
, uattr
, size
);
7998 if (attr
->__reserved_1
)
8001 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
8004 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
8007 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
8008 u64 mask
= attr
->branch_sample_type
;
8010 /* only using defined bits */
8011 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
8014 /* at least one branch bit must be set */
8015 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
8018 /* propagate priv level, when not set for branch */
8019 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
8021 /* exclude_kernel checked on syscall entry */
8022 if (!attr
->exclude_kernel
)
8023 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8025 if (!attr
->exclude_user
)
8026 mask
|= PERF_SAMPLE_BRANCH_USER
;
8028 if (!attr
->exclude_hv
)
8029 mask
|= PERF_SAMPLE_BRANCH_HV
;
8031 * adjust user setting (for HW filter setup)
8033 attr
->branch_sample_type
= mask
;
8035 /* privileged levels capture (kernel, hv): check permissions */
8036 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8037 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8041 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8042 ret
= perf_reg_validate(attr
->sample_regs_user
);
8047 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8048 if (!arch_perf_have_user_stack_dump())
8052 * We have __u32 type for the size, but so far
8053 * we can only use __u16 as maximum due to the
8054 * __u16 sample size limit.
8056 if (attr
->sample_stack_user
>= USHRT_MAX
)
8058 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8062 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8063 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8068 put_user(sizeof(*attr
), &uattr
->size
);
8074 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8076 struct ring_buffer
*rb
= NULL
;
8082 /* don't allow circular references */
8083 if (event
== output_event
)
8087 * Don't allow cross-cpu buffers
8089 if (output_event
->cpu
!= event
->cpu
)
8093 * If its not a per-cpu rb, it must be the same task.
8095 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8099 * Mixing clocks in the same buffer is trouble you don't need.
8101 if (output_event
->clock
!= event
->clock
)
8105 * If both events generate aux data, they must be on the same PMU
8107 if (has_aux(event
) && has_aux(output_event
) &&
8108 event
->pmu
!= output_event
->pmu
)
8112 mutex_lock(&event
->mmap_mutex
);
8113 /* Can't redirect output if we've got an active mmap() */
8114 if (atomic_read(&event
->mmap_count
))
8118 /* get the rb we want to redirect to */
8119 rb
= ring_buffer_get(output_event
);
8124 ring_buffer_attach(event
, rb
);
8128 mutex_unlock(&event
->mmap_mutex
);
8134 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8140 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8143 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8145 bool nmi_safe
= false;
8148 case CLOCK_MONOTONIC
:
8149 event
->clock
= &ktime_get_mono_fast_ns
;
8153 case CLOCK_MONOTONIC_RAW
:
8154 event
->clock
= &ktime_get_raw_fast_ns
;
8158 case CLOCK_REALTIME
:
8159 event
->clock
= &ktime_get_real_ns
;
8162 case CLOCK_BOOTTIME
:
8163 event
->clock
= &ktime_get_boot_ns
;
8167 event
->clock
= &ktime_get_tai_ns
;
8174 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8181 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8183 * @attr_uptr: event_id type attributes for monitoring/sampling
8186 * @group_fd: group leader event fd
8188 SYSCALL_DEFINE5(perf_event_open
,
8189 struct perf_event_attr __user
*, attr_uptr
,
8190 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8192 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8193 struct perf_event
*event
, *sibling
;
8194 struct perf_event_attr attr
;
8195 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8196 struct file
*event_file
= NULL
;
8197 struct fd group
= {NULL
, 0};
8198 struct task_struct
*task
= NULL
;
8203 int f_flags
= O_RDWR
;
8206 /* for future expandability... */
8207 if (flags
& ~PERF_FLAG_ALL
)
8210 err
= perf_copy_attr(attr_uptr
, &attr
);
8214 if (!attr
.exclude_kernel
) {
8215 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8220 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8223 if (attr
.sample_period
& (1ULL << 63))
8228 * In cgroup mode, the pid argument is used to pass the fd
8229 * opened to the cgroup directory in cgroupfs. The cpu argument
8230 * designates the cpu on which to monitor threads from that
8233 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8236 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8237 f_flags
|= O_CLOEXEC
;
8239 event_fd
= get_unused_fd_flags(f_flags
);
8243 if (group_fd
!= -1) {
8244 err
= perf_fget_light(group_fd
, &group
);
8247 group_leader
= group
.file
->private_data
;
8248 if (flags
& PERF_FLAG_FD_OUTPUT
)
8249 output_event
= group_leader
;
8250 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8251 group_leader
= NULL
;
8254 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8255 task
= find_lively_task_by_vpid(pid
);
8257 err
= PTR_ERR(task
);
8262 if (task
&& group_leader
&&
8263 group_leader
->attr
.inherit
!= attr
.inherit
) {
8270 if (flags
& PERF_FLAG_PID_CGROUP
)
8273 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8274 NULL
, NULL
, cgroup_fd
);
8275 if (IS_ERR(event
)) {
8276 err
= PTR_ERR(event
);
8280 if (is_sampling_event(event
)) {
8281 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8287 account_event(event
);
8290 * Special case software events and allow them to be part of
8291 * any hardware group.
8295 if (attr
.use_clockid
) {
8296 err
= perf_event_set_clock(event
, attr
.clockid
);
8302 (is_software_event(event
) != is_software_event(group_leader
))) {
8303 if (is_software_event(event
)) {
8305 * If event and group_leader are not both a software
8306 * event, and event is, then group leader is not.
8308 * Allow the addition of software events to !software
8309 * groups, this is safe because software events never
8312 pmu
= group_leader
->pmu
;
8313 } else if (is_software_event(group_leader
) &&
8314 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8316 * In case the group is a pure software group, and we
8317 * try to add a hardware event, move the whole group to
8318 * the hardware context.
8325 * Get the target context (task or percpu):
8327 ctx
= find_get_context(pmu
, task
, event
);
8333 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8339 put_task_struct(task
);
8344 * Look up the group leader (we will attach this event to it):
8350 * Do not allow a recursive hierarchy (this new sibling
8351 * becoming part of another group-sibling):
8353 if (group_leader
->group_leader
!= group_leader
)
8356 /* All events in a group should have the same clock */
8357 if (group_leader
->clock
!= event
->clock
)
8361 * Do not allow to attach to a group in a different
8362 * task or CPU context:
8366 * Make sure we're both on the same task, or both
8369 if (group_leader
->ctx
->task
!= ctx
->task
)
8373 * Make sure we're both events for the same CPU;
8374 * grouping events for different CPUs is broken; since
8375 * you can never concurrently schedule them anyhow.
8377 if (group_leader
->cpu
!= event
->cpu
)
8380 if (group_leader
->ctx
!= ctx
)
8385 * Only a group leader can be exclusive or pinned
8387 if (attr
.exclusive
|| attr
.pinned
)
8392 err
= perf_event_set_output(event
, output_event
);
8397 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8399 if (IS_ERR(event_file
)) {
8400 err
= PTR_ERR(event_file
);
8405 gctx
= group_leader
->ctx
;
8406 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8408 mutex_lock(&ctx
->mutex
);
8411 if (!perf_event_validate_size(event
)) {
8417 * Must be under the same ctx::mutex as perf_install_in_context(),
8418 * because we need to serialize with concurrent event creation.
8420 if (!exclusive_event_installable(event
, ctx
)) {
8421 /* exclusive and group stuff are assumed mutually exclusive */
8422 WARN_ON_ONCE(move_group
);
8428 WARN_ON_ONCE(ctx
->parent_ctx
);
8432 * See perf_event_ctx_lock() for comments on the details
8433 * of swizzling perf_event::ctx.
8435 perf_remove_from_context(group_leader
, false);
8437 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8439 perf_remove_from_context(sibling
, false);
8444 * Wait for everybody to stop referencing the events through
8445 * the old lists, before installing it on new lists.
8450 * Install the group siblings before the group leader.
8452 * Because a group leader will try and install the entire group
8453 * (through the sibling list, which is still in-tact), we can
8454 * end up with siblings installed in the wrong context.
8456 * By installing siblings first we NO-OP because they're not
8457 * reachable through the group lists.
8459 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8461 perf_event__state_init(sibling
);
8462 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8467 * Removing from the context ends up with disabled
8468 * event. What we want here is event in the initial
8469 * startup state, ready to be add into new context.
8471 perf_event__state_init(group_leader
);
8472 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8476 * Now that all events are installed in @ctx, nothing
8477 * references @gctx anymore, so drop the last reference we have
8484 * Precalculate sample_data sizes; do while holding ctx::mutex such
8485 * that we're serialized against further additions and before
8486 * perf_install_in_context() which is the point the event is active and
8487 * can use these values.
8489 perf_event__header_size(event
);
8490 perf_event__id_header_size(event
);
8492 event
->owner
= current
;
8494 perf_install_in_context(ctx
, event
, event
->cpu
);
8495 perf_unpin_context(ctx
);
8498 mutex_unlock(&gctx
->mutex
);
8499 mutex_unlock(&ctx
->mutex
);
8503 mutex_lock(¤t
->perf_event_mutex
);
8504 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8505 mutex_unlock(¤t
->perf_event_mutex
);
8508 * Drop the reference on the group_event after placing the
8509 * new event on the sibling_list. This ensures destruction
8510 * of the group leader will find the pointer to itself in
8511 * perf_group_detach().
8514 fd_install(event_fd
, event_file
);
8519 mutex_unlock(&gctx
->mutex
);
8520 mutex_unlock(&ctx
->mutex
);
8524 perf_unpin_context(ctx
);
8532 put_task_struct(task
);
8536 put_unused_fd(event_fd
);
8541 * perf_event_create_kernel_counter
8543 * @attr: attributes of the counter to create
8544 * @cpu: cpu in which the counter is bound
8545 * @task: task to profile (NULL for percpu)
8548 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8549 struct task_struct
*task
,
8550 perf_overflow_handler_t overflow_handler
,
8553 struct perf_event_context
*ctx
;
8554 struct perf_event
*event
;
8558 * Get the target context (task or percpu):
8561 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8562 overflow_handler
, context
, -1);
8563 if (IS_ERR(event
)) {
8564 err
= PTR_ERR(event
);
8568 /* Mark owner so we could distinguish it from user events. */
8569 event
->owner
= TASK_TOMBSTONE
;
8571 account_event(event
);
8573 ctx
= find_get_context(event
->pmu
, task
, event
);
8579 WARN_ON_ONCE(ctx
->parent_ctx
);
8580 mutex_lock(&ctx
->mutex
);
8581 if (!exclusive_event_installable(event
, ctx
)) {
8582 mutex_unlock(&ctx
->mutex
);
8583 perf_unpin_context(ctx
);
8589 perf_install_in_context(ctx
, event
, cpu
);
8590 perf_unpin_context(ctx
);
8591 mutex_unlock(&ctx
->mutex
);
8598 return ERR_PTR(err
);
8600 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8602 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8604 struct perf_event_context
*src_ctx
;
8605 struct perf_event_context
*dst_ctx
;
8606 struct perf_event
*event
, *tmp
;
8609 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8610 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8613 * See perf_event_ctx_lock() for comments on the details
8614 * of swizzling perf_event::ctx.
8616 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8617 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8619 perf_remove_from_context(event
, false);
8620 unaccount_event_cpu(event
, src_cpu
);
8622 list_add(&event
->migrate_entry
, &events
);
8626 * Wait for the events to quiesce before re-instating them.
8631 * Re-instate events in 2 passes.
8633 * Skip over group leaders and only install siblings on this first
8634 * pass, siblings will not get enabled without a leader, however a
8635 * leader will enable its siblings, even if those are still on the old
8638 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8639 if (event
->group_leader
== event
)
8642 list_del(&event
->migrate_entry
);
8643 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8644 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8645 account_event_cpu(event
, dst_cpu
);
8646 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8651 * Once all the siblings are setup properly, install the group leaders
8654 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8655 list_del(&event
->migrate_entry
);
8656 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8657 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8658 account_event_cpu(event
, dst_cpu
);
8659 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8662 mutex_unlock(&dst_ctx
->mutex
);
8663 mutex_unlock(&src_ctx
->mutex
);
8665 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8667 static void sync_child_event(struct perf_event
*child_event
,
8668 struct task_struct
*child
)
8670 struct perf_event
*parent_event
= child_event
->parent
;
8673 if (child_event
->attr
.inherit_stat
)
8674 perf_event_read_event(child_event
, child
);
8676 child_val
= perf_event_count(child_event
);
8679 * Add back the child's count to the parent's count:
8681 atomic64_add(child_val
, &parent_event
->child_count
);
8682 atomic64_add(child_event
->total_time_enabled
,
8683 &parent_event
->child_total_time_enabled
);
8684 atomic64_add(child_event
->total_time_running
,
8685 &parent_event
->child_total_time_running
);
8688 * Remove this event from the parent's list
8690 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8691 mutex_lock(&parent_event
->child_mutex
);
8692 list_del_init(&child_event
->child_list
);
8693 mutex_unlock(&parent_event
->child_mutex
);
8696 * Make sure user/parent get notified, that we just
8699 perf_event_wakeup(parent_event
);
8702 * Release the parent event, if this was the last
8705 put_event(parent_event
);
8709 __perf_event_exit_task(struct perf_event
*child_event
,
8710 struct perf_event_context
*child_ctx
,
8711 struct task_struct
*child
)
8714 * Do not destroy the 'original' grouping; because of the context
8715 * switch optimization the original events could've ended up in a
8716 * random child task.
8718 * If we were to destroy the original group, all group related
8719 * operations would cease to function properly after this random
8722 * Do destroy all inherited groups, we don't care about those
8723 * and being thorough is better.
8725 raw_spin_lock_irq(&child_ctx
->lock
);
8726 WARN_ON_ONCE(child_ctx
->is_active
);
8728 if (!!child_event
->parent
)
8729 perf_group_detach(child_event
);
8730 list_del_event(child_event
, child_ctx
);
8731 raw_spin_unlock_irq(&child_ctx
->lock
);
8734 * It can happen that the parent exits first, and has events
8735 * that are still around due to the child reference. These
8736 * events need to be zapped.
8738 if (child_event
->parent
) {
8739 sync_child_event(child_event
, child
);
8740 free_event(child_event
);
8742 child_event
->state
= PERF_EVENT_STATE_EXIT
;
8743 perf_event_wakeup(child_event
);
8747 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8749 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8750 struct perf_event
*child_event
, *next
;
8751 unsigned long flags
;
8753 WARN_ON_ONCE(child
!= current
);
8755 child_ctx
= perf_lock_task_context(child
, ctxn
, &flags
);
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 */
8771 * If this context is a clone; unclone it so it can't get
8772 * swapped to another process while we're removing all
8773 * the events from it.
8775 clone_ctx
= unclone_ctx(child_ctx
);
8776 update_context_time(child_ctx
);
8777 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8783 * Report the task dead after unscheduling the events so that we
8784 * won't get any samples after PERF_RECORD_EXIT. We can however still
8785 * get a few PERF_RECORD_READ events.
8787 perf_event_task(child
, child_ctx
, 0);
8790 * We can recurse on the same lock type through:
8792 * __perf_event_exit_task()
8793 * sync_child_event()
8795 * mutex_lock(&ctx->mutex)
8797 * But since its the parent context it won't be the same instance.
8799 mutex_lock(&child_ctx
->mutex
);
8801 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8802 __perf_event_exit_task(child_event
, child_ctx
, child
);
8804 mutex_unlock(&child_ctx
->mutex
);
8810 * When a child task exits, feed back event values to parent events.
8812 void perf_event_exit_task(struct task_struct
*child
)
8814 struct perf_event
*event
, *tmp
;
8817 mutex_lock(&child
->perf_event_mutex
);
8818 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8820 list_del_init(&event
->owner_entry
);
8823 * Ensure the list deletion is visible before we clear
8824 * the owner, closes a race against perf_release() where
8825 * we need to serialize on the owner->perf_event_mutex.
8828 event
->owner
= NULL
;
8830 mutex_unlock(&child
->perf_event_mutex
);
8832 for_each_task_context_nr(ctxn
)
8833 perf_event_exit_task_context(child
, ctxn
);
8836 * The perf_event_exit_task_context calls perf_event_task
8837 * with child's task_ctx, which generates EXIT events for
8838 * child contexts and sets child->perf_event_ctxp[] to NULL.
8839 * At this point we need to send EXIT events to cpu contexts.
8841 perf_event_task(child
, NULL
, 0);
8844 static void perf_free_event(struct perf_event
*event
,
8845 struct perf_event_context
*ctx
)
8847 struct perf_event
*parent
= event
->parent
;
8849 if (WARN_ON_ONCE(!parent
))
8852 mutex_lock(&parent
->child_mutex
);
8853 list_del_init(&event
->child_list
);
8854 mutex_unlock(&parent
->child_mutex
);
8858 raw_spin_lock_irq(&ctx
->lock
);
8859 perf_group_detach(event
);
8860 list_del_event(event
, ctx
);
8861 raw_spin_unlock_irq(&ctx
->lock
);
8866 * Free an unexposed, unused context as created by inheritance by
8867 * perf_event_init_task below, used by fork() in case of fail.
8869 * Not all locks are strictly required, but take them anyway to be nice and
8870 * help out with the lockdep assertions.
8872 void perf_event_free_task(struct task_struct
*task
)
8874 struct perf_event_context
*ctx
;
8875 struct perf_event
*event
, *tmp
;
8878 for_each_task_context_nr(ctxn
) {
8879 ctx
= task
->perf_event_ctxp
[ctxn
];
8883 mutex_lock(&ctx
->mutex
);
8885 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8887 perf_free_event(event
, ctx
);
8889 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8891 perf_free_event(event
, ctx
);
8893 if (!list_empty(&ctx
->pinned_groups
) ||
8894 !list_empty(&ctx
->flexible_groups
))
8897 mutex_unlock(&ctx
->mutex
);
8903 void perf_event_delayed_put(struct task_struct
*task
)
8907 for_each_task_context_nr(ctxn
)
8908 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8911 struct perf_event
*perf_event_get(unsigned int fd
)
8915 struct perf_event
*event
;
8917 err
= perf_fget_light(fd
, &f
);
8919 return ERR_PTR(err
);
8921 event
= f
.file
->private_data
;
8922 atomic_long_inc(&event
->refcount
);
8928 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
8931 return ERR_PTR(-EINVAL
);
8933 return &event
->attr
;
8937 * inherit a event from parent task to child task:
8939 static struct perf_event
*
8940 inherit_event(struct perf_event
*parent_event
,
8941 struct task_struct
*parent
,
8942 struct perf_event_context
*parent_ctx
,
8943 struct task_struct
*child
,
8944 struct perf_event
*group_leader
,
8945 struct perf_event_context
*child_ctx
)
8947 enum perf_event_active_state parent_state
= parent_event
->state
;
8948 struct perf_event
*child_event
;
8949 unsigned long flags
;
8952 * Instead of creating recursive hierarchies of events,
8953 * we link inherited events back to the original parent,
8954 * which has a filp for sure, which we use as the reference
8957 if (parent_event
->parent
)
8958 parent_event
= parent_event
->parent
;
8960 child_event
= perf_event_alloc(&parent_event
->attr
,
8963 group_leader
, parent_event
,
8965 if (IS_ERR(child_event
))
8968 if (is_orphaned_event(parent_event
) ||
8969 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
8970 free_event(child_event
);
8977 * Make the child state follow the state of the parent event,
8978 * not its attr.disabled bit. We hold the parent's mutex,
8979 * so we won't race with perf_event_{en, dis}able_family.
8981 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
8982 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
8984 child_event
->state
= PERF_EVENT_STATE_OFF
;
8986 if (parent_event
->attr
.freq
) {
8987 u64 sample_period
= parent_event
->hw
.sample_period
;
8988 struct hw_perf_event
*hwc
= &child_event
->hw
;
8990 hwc
->sample_period
= sample_period
;
8991 hwc
->last_period
= sample_period
;
8993 local64_set(&hwc
->period_left
, sample_period
);
8996 child_event
->ctx
= child_ctx
;
8997 child_event
->overflow_handler
= parent_event
->overflow_handler
;
8998 child_event
->overflow_handler_context
8999 = parent_event
->overflow_handler_context
;
9002 * Precalculate sample_data sizes
9004 perf_event__header_size(child_event
);
9005 perf_event__id_header_size(child_event
);
9008 * Link it up in the child's context:
9010 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
9011 add_event_to_ctx(child_event
, child_ctx
);
9012 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
9015 * Link this into the parent event's child list
9017 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
9018 mutex_lock(&parent_event
->child_mutex
);
9019 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
9020 mutex_unlock(&parent_event
->child_mutex
);
9025 static int inherit_group(struct perf_event
*parent_event
,
9026 struct task_struct
*parent
,
9027 struct perf_event_context
*parent_ctx
,
9028 struct task_struct
*child
,
9029 struct perf_event_context
*child_ctx
)
9031 struct perf_event
*leader
;
9032 struct perf_event
*sub
;
9033 struct perf_event
*child_ctr
;
9035 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9036 child
, NULL
, child_ctx
);
9038 return PTR_ERR(leader
);
9039 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9040 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9041 child
, leader
, child_ctx
);
9042 if (IS_ERR(child_ctr
))
9043 return PTR_ERR(child_ctr
);
9049 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9050 struct perf_event_context
*parent_ctx
,
9051 struct task_struct
*child
, int ctxn
,
9055 struct perf_event_context
*child_ctx
;
9057 if (!event
->attr
.inherit
) {
9062 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9065 * This is executed from the parent task context, so
9066 * inherit events that have been marked for cloning.
9067 * First allocate and initialize a context for the
9071 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9075 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9078 ret
= inherit_group(event
, parent
, parent_ctx
,
9088 * Initialize the perf_event context in task_struct
9090 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9092 struct perf_event_context
*child_ctx
, *parent_ctx
;
9093 struct perf_event_context
*cloned_ctx
;
9094 struct perf_event
*event
;
9095 struct task_struct
*parent
= current
;
9096 int inherited_all
= 1;
9097 unsigned long flags
;
9100 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9104 * If the parent's context is a clone, pin it so it won't get
9107 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9112 * No need to check if parent_ctx != NULL here; since we saw
9113 * it non-NULL earlier, the only reason for it to become NULL
9114 * is if we exit, and since we're currently in the middle of
9115 * a fork we can't be exiting at the same time.
9119 * Lock the parent list. No need to lock the child - not PID
9120 * hashed yet and not running, so nobody can access it.
9122 mutex_lock(&parent_ctx
->mutex
);
9125 * We dont have to disable NMIs - we are only looking at
9126 * the list, not manipulating it:
9128 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9129 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9130 child
, ctxn
, &inherited_all
);
9136 * We can't hold ctx->lock when iterating the ->flexible_group list due
9137 * to allocations, but we need to prevent rotation because
9138 * rotate_ctx() will change the list from interrupt context.
9140 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9141 parent_ctx
->rotate_disable
= 1;
9142 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9144 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9145 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9146 child
, ctxn
, &inherited_all
);
9151 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9152 parent_ctx
->rotate_disable
= 0;
9154 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9156 if (child_ctx
&& inherited_all
) {
9158 * Mark the child context as a clone of the parent
9159 * context, or of whatever the parent is a clone of.
9161 * Note that if the parent is a clone, the holding of
9162 * parent_ctx->lock avoids it from being uncloned.
9164 cloned_ctx
= parent_ctx
->parent_ctx
;
9166 child_ctx
->parent_ctx
= cloned_ctx
;
9167 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9169 child_ctx
->parent_ctx
= parent_ctx
;
9170 child_ctx
->parent_gen
= parent_ctx
->generation
;
9172 get_ctx(child_ctx
->parent_ctx
);
9175 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9176 mutex_unlock(&parent_ctx
->mutex
);
9178 perf_unpin_context(parent_ctx
);
9179 put_ctx(parent_ctx
);
9185 * Initialize the perf_event context in task_struct
9187 int perf_event_init_task(struct task_struct
*child
)
9191 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9192 mutex_init(&child
->perf_event_mutex
);
9193 INIT_LIST_HEAD(&child
->perf_event_list
);
9195 for_each_task_context_nr(ctxn
) {
9196 ret
= perf_event_init_context(child
, ctxn
);
9198 perf_event_free_task(child
);
9206 static void __init
perf_event_init_all_cpus(void)
9208 struct swevent_htable
*swhash
;
9211 for_each_possible_cpu(cpu
) {
9212 swhash
= &per_cpu(swevent_htable
, cpu
);
9213 mutex_init(&swhash
->hlist_mutex
);
9214 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9218 static void perf_event_init_cpu(int cpu
)
9220 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9222 mutex_lock(&swhash
->hlist_mutex
);
9223 if (swhash
->hlist_refcount
> 0) {
9224 struct swevent_hlist
*hlist
;
9226 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9228 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9230 mutex_unlock(&swhash
->hlist_mutex
);
9233 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9234 static void __perf_event_exit_context(void *__info
)
9236 struct perf_event_context
*ctx
= __info
;
9237 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
9238 struct perf_event
*event
;
9240 raw_spin_lock(&ctx
->lock
);
9241 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
9242 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)(unsigned long)true);
9243 raw_spin_unlock(&ctx
->lock
);
9246 static void perf_event_exit_cpu_context(int cpu
)
9248 struct perf_event_context
*ctx
;
9252 idx
= srcu_read_lock(&pmus_srcu
);
9253 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9254 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9256 mutex_lock(&ctx
->mutex
);
9257 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9258 mutex_unlock(&ctx
->mutex
);
9260 srcu_read_unlock(&pmus_srcu
, idx
);
9263 static void perf_event_exit_cpu(int cpu
)
9265 perf_event_exit_cpu_context(cpu
);
9268 static inline void perf_event_exit_cpu(int cpu
) { }
9272 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9276 for_each_online_cpu(cpu
)
9277 perf_event_exit_cpu(cpu
);
9283 * Run the perf reboot notifier at the very last possible moment so that
9284 * the generic watchdog code runs as long as possible.
9286 static struct notifier_block perf_reboot_notifier
= {
9287 .notifier_call
= perf_reboot
,
9288 .priority
= INT_MIN
,
9292 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9294 unsigned int cpu
= (long)hcpu
;
9296 switch (action
& ~CPU_TASKS_FROZEN
) {
9298 case CPU_UP_PREPARE
:
9299 case CPU_DOWN_FAILED
:
9300 perf_event_init_cpu(cpu
);
9303 case CPU_UP_CANCELED
:
9304 case CPU_DOWN_PREPARE
:
9305 perf_event_exit_cpu(cpu
);
9314 void __init
perf_event_init(void)
9320 perf_event_init_all_cpus();
9321 init_srcu_struct(&pmus_srcu
);
9322 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9323 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9324 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9326 perf_cpu_notifier(perf_cpu_notify
);
9327 register_reboot_notifier(&perf_reboot_notifier
);
9329 ret
= init_hw_breakpoint();
9330 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9332 /* do not patch jump label more than once per second */
9333 jump_label_rate_limit(&perf_sched_events
, HZ
);
9336 * Build time assertion that we keep the data_head at the intended
9337 * location. IOW, validation we got the __reserved[] size right.
9339 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9343 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9346 struct perf_pmu_events_attr
*pmu_attr
=
9347 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9349 if (pmu_attr
->event_str
)
9350 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9355 static int __init
perf_event_sysfs_init(void)
9360 mutex_lock(&pmus_lock
);
9362 ret
= bus_register(&pmu_bus
);
9366 list_for_each_entry(pmu
, &pmus
, entry
) {
9367 if (!pmu
->name
|| pmu
->type
< 0)
9370 ret
= pmu_dev_alloc(pmu
);
9371 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9373 pmu_bus_running
= 1;
9377 mutex_unlock(&pmus_lock
);
9381 device_initcall(perf_event_sysfs_init
);
9383 #ifdef CONFIG_CGROUP_PERF
9384 static struct cgroup_subsys_state
*
9385 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9387 struct perf_cgroup
*jc
;
9389 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9391 return ERR_PTR(-ENOMEM
);
9393 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9396 return ERR_PTR(-ENOMEM
);
9402 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9404 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9406 free_percpu(jc
->info
);
9410 static int __perf_cgroup_move(void *info
)
9412 struct task_struct
*task
= info
;
9414 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9419 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
9421 struct task_struct
*task
;
9422 struct cgroup_subsys_state
*css
;
9424 cgroup_taskset_for_each(task
, css
, tset
)
9425 task_function_call(task
, __perf_cgroup_move
, task
);
9428 struct cgroup_subsys perf_event_cgrp_subsys
= {
9429 .css_alloc
= perf_cgroup_css_alloc
,
9430 .css_free
= perf_cgroup_css_free
,
9431 .attach
= perf_cgroup_attach
,
9433 #endif /* CONFIG_CGROUP_PERF */