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::child_mutex;
1090 * perf_event_context::lock
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
);
1234 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
||
2257 event
->state
<= PERF_EVENT_STATE_ERROR
)
2260 update_context_time(ctx
);
2261 __perf_event_mark_enabled(event
);
2263 if (!ctx
->is_active
)
2266 if (!event_filter_match(event
)) {
2267 if (is_cgroup_event(event
)) {
2268 perf_cgroup_set_timestamp(current
, ctx
); // XXX ?
2269 perf_cgroup_defer_enabled(event
);
2275 * If the event is in a group and isn't the group leader,
2276 * then don't put it on unless the group is on.
2278 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2281 task_ctx
= cpuctx
->task_ctx
;
2283 WARN_ON_ONCE(task_ctx
!= ctx
);
2285 ctx_resched(cpuctx
, task_ctx
);
2291 * If event->ctx is a cloned context, callers must make sure that
2292 * every task struct that event->ctx->task could possibly point to
2293 * remains valid. This condition is satisfied when called through
2294 * perf_event_for_each_child or perf_event_for_each as described
2295 * for perf_event_disable.
2297 static void _perf_event_enable(struct perf_event
*event
)
2299 struct perf_event_context
*ctx
= event
->ctx
;
2301 raw_spin_lock_irq(&ctx
->lock
);
2302 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2303 event
->state
< PERF_EVENT_STATE_ERROR
) {
2304 raw_spin_unlock_irq(&ctx
->lock
);
2309 * If the event is in error state, clear that first.
2311 * That way, if we see the event in error state below, we know that it
2312 * has gone back into error state, as distinct from the task having
2313 * been scheduled away before the cross-call arrived.
2315 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2316 event
->state
= PERF_EVENT_STATE_OFF
;
2317 raw_spin_unlock_irq(&ctx
->lock
);
2319 event_function_call(event
, __perf_event_enable
, NULL
);
2323 * See perf_event_disable();
2325 void perf_event_enable(struct perf_event
*event
)
2327 struct perf_event_context
*ctx
;
2329 ctx
= perf_event_ctx_lock(event
);
2330 _perf_event_enable(event
);
2331 perf_event_ctx_unlock(event
, ctx
);
2333 EXPORT_SYMBOL_GPL(perf_event_enable
);
2335 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2338 * not supported on inherited events
2340 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2343 atomic_add(refresh
, &event
->event_limit
);
2344 _perf_event_enable(event
);
2350 * See perf_event_disable()
2352 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2354 struct perf_event_context
*ctx
;
2357 ctx
= perf_event_ctx_lock(event
);
2358 ret
= _perf_event_refresh(event
, refresh
);
2359 perf_event_ctx_unlock(event
, ctx
);
2363 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2365 static void ctx_sched_out(struct perf_event_context
*ctx
,
2366 struct perf_cpu_context
*cpuctx
,
2367 enum event_type_t event_type
)
2369 int is_active
= ctx
->is_active
;
2370 struct perf_event
*event
;
2372 lockdep_assert_held(&ctx
->lock
);
2374 if (likely(!ctx
->nr_events
)) {
2376 * See __perf_remove_from_context().
2378 WARN_ON_ONCE(ctx
->is_active
);
2380 WARN_ON_ONCE(cpuctx
->task_ctx
);
2384 ctx
->is_active
&= ~event_type
;
2386 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2387 if (!ctx
->is_active
)
2388 cpuctx
->task_ctx
= NULL
;
2391 update_context_time(ctx
);
2392 update_cgrp_time_from_cpuctx(cpuctx
);
2393 if (!ctx
->nr_active
)
2396 perf_pmu_disable(ctx
->pmu
);
2397 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2398 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2399 group_sched_out(event
, cpuctx
, ctx
);
2402 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2403 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2404 group_sched_out(event
, cpuctx
, ctx
);
2406 perf_pmu_enable(ctx
->pmu
);
2410 * Test whether two contexts are equivalent, i.e. whether they have both been
2411 * cloned from the same version of the same context.
2413 * Equivalence is measured using a generation number in the context that is
2414 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2415 * and list_del_event().
2417 static int context_equiv(struct perf_event_context
*ctx1
,
2418 struct perf_event_context
*ctx2
)
2420 lockdep_assert_held(&ctx1
->lock
);
2421 lockdep_assert_held(&ctx2
->lock
);
2423 /* Pinning disables the swap optimization */
2424 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2427 /* If ctx1 is the parent of ctx2 */
2428 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2431 /* If ctx2 is the parent of ctx1 */
2432 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2436 * If ctx1 and ctx2 have the same parent; we flatten the parent
2437 * hierarchy, see perf_event_init_context().
2439 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2440 ctx1
->parent_gen
== ctx2
->parent_gen
)
2447 static void __perf_event_sync_stat(struct perf_event
*event
,
2448 struct perf_event
*next_event
)
2452 if (!event
->attr
.inherit_stat
)
2456 * Update the event value, we cannot use perf_event_read()
2457 * because we're in the middle of a context switch and have IRQs
2458 * disabled, which upsets smp_call_function_single(), however
2459 * we know the event must be on the current CPU, therefore we
2460 * don't need to use it.
2462 switch (event
->state
) {
2463 case PERF_EVENT_STATE_ACTIVE
:
2464 event
->pmu
->read(event
);
2467 case PERF_EVENT_STATE_INACTIVE
:
2468 update_event_times(event
);
2476 * In order to keep per-task stats reliable we need to flip the event
2477 * values when we flip the contexts.
2479 value
= local64_read(&next_event
->count
);
2480 value
= local64_xchg(&event
->count
, value
);
2481 local64_set(&next_event
->count
, value
);
2483 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2484 swap(event
->total_time_running
, next_event
->total_time_running
);
2487 * Since we swizzled the values, update the user visible data too.
2489 perf_event_update_userpage(event
);
2490 perf_event_update_userpage(next_event
);
2493 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2494 struct perf_event_context
*next_ctx
)
2496 struct perf_event
*event
, *next_event
;
2501 update_context_time(ctx
);
2503 event
= list_first_entry(&ctx
->event_list
,
2504 struct perf_event
, event_entry
);
2506 next_event
= list_first_entry(&next_ctx
->event_list
,
2507 struct perf_event
, event_entry
);
2509 while (&event
->event_entry
!= &ctx
->event_list
&&
2510 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2512 __perf_event_sync_stat(event
, next_event
);
2514 event
= list_next_entry(event
, event_entry
);
2515 next_event
= list_next_entry(next_event
, event_entry
);
2519 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2520 struct task_struct
*next
)
2522 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2523 struct perf_event_context
*next_ctx
;
2524 struct perf_event_context
*parent
, *next_parent
;
2525 struct perf_cpu_context
*cpuctx
;
2531 cpuctx
= __get_cpu_context(ctx
);
2532 if (!cpuctx
->task_ctx
)
2536 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2540 parent
= rcu_dereference(ctx
->parent_ctx
);
2541 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2543 /* If neither context have a parent context; they cannot be clones. */
2544 if (!parent
&& !next_parent
)
2547 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2549 * Looks like the two contexts are clones, so we might be
2550 * able to optimize the context switch. We lock both
2551 * contexts and check that they are clones under the
2552 * lock (including re-checking that neither has been
2553 * uncloned in the meantime). It doesn't matter which
2554 * order we take the locks because no other cpu could
2555 * be trying to lock both of these tasks.
2557 raw_spin_lock(&ctx
->lock
);
2558 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2559 if (context_equiv(ctx
, next_ctx
)) {
2560 WRITE_ONCE(ctx
->task
, next
);
2561 WRITE_ONCE(next_ctx
->task
, task
);
2563 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2566 * RCU_INIT_POINTER here is safe because we've not
2567 * modified the ctx and the above modification of
2568 * ctx->task and ctx->task_ctx_data are immaterial
2569 * since those values are always verified under
2570 * ctx->lock which we're now holding.
2572 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2573 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2577 perf_event_sync_stat(ctx
, next_ctx
);
2579 raw_spin_unlock(&next_ctx
->lock
);
2580 raw_spin_unlock(&ctx
->lock
);
2586 raw_spin_lock(&ctx
->lock
);
2587 task_ctx_sched_out(cpuctx
, ctx
);
2588 raw_spin_unlock(&ctx
->lock
);
2592 void perf_sched_cb_dec(struct pmu
*pmu
)
2594 this_cpu_dec(perf_sched_cb_usages
);
2597 void perf_sched_cb_inc(struct pmu
*pmu
)
2599 this_cpu_inc(perf_sched_cb_usages
);
2603 * This function provides the context switch callback to the lower code
2604 * layer. It is invoked ONLY when the context switch callback is enabled.
2606 static void perf_pmu_sched_task(struct task_struct
*prev
,
2607 struct task_struct
*next
,
2610 struct perf_cpu_context
*cpuctx
;
2612 unsigned long flags
;
2617 local_irq_save(flags
);
2621 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2622 if (pmu
->sched_task
) {
2623 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2625 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2627 perf_pmu_disable(pmu
);
2629 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2631 perf_pmu_enable(pmu
);
2633 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2639 local_irq_restore(flags
);
2642 static void perf_event_switch(struct task_struct
*task
,
2643 struct task_struct
*next_prev
, bool sched_in
);
2645 #define for_each_task_context_nr(ctxn) \
2646 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2649 * Called from scheduler to remove the events of the current task,
2650 * with interrupts disabled.
2652 * We stop each event and update the event value in event->count.
2654 * This does not protect us against NMI, but disable()
2655 * sets the disabled bit in the control field of event _before_
2656 * accessing the event control register. If a NMI hits, then it will
2657 * not restart the event.
2659 void __perf_event_task_sched_out(struct task_struct
*task
,
2660 struct task_struct
*next
)
2664 if (__this_cpu_read(perf_sched_cb_usages
))
2665 perf_pmu_sched_task(task
, next
, false);
2667 if (atomic_read(&nr_switch_events
))
2668 perf_event_switch(task
, next
, false);
2670 for_each_task_context_nr(ctxn
)
2671 perf_event_context_sched_out(task
, ctxn
, next
);
2674 * if cgroup events exist on this CPU, then we need
2675 * to check if we have to switch out PMU state.
2676 * cgroup event are system-wide mode only
2678 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2679 perf_cgroup_sched_out(task
, next
);
2682 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2683 struct perf_event_context
*ctx
)
2685 if (!cpuctx
->task_ctx
)
2688 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2691 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2695 * Called with IRQs disabled
2697 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2698 enum event_type_t event_type
)
2700 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2704 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2705 struct perf_cpu_context
*cpuctx
)
2707 struct perf_event
*event
;
2709 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2710 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2712 if (!event_filter_match(event
))
2715 /* may need to reset tstamp_enabled */
2716 if (is_cgroup_event(event
))
2717 perf_cgroup_mark_enabled(event
, ctx
);
2719 if (group_can_go_on(event
, cpuctx
, 1))
2720 group_sched_in(event
, cpuctx
, ctx
);
2723 * If this pinned group hasn't been scheduled,
2724 * put it in error state.
2726 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2727 update_group_times(event
);
2728 event
->state
= PERF_EVENT_STATE_ERROR
;
2734 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2735 struct perf_cpu_context
*cpuctx
)
2737 struct perf_event
*event
;
2740 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2741 /* Ignore events in OFF or ERROR state */
2742 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2745 * Listen to the 'cpu' scheduling filter constraint
2748 if (!event_filter_match(event
))
2751 /* may need to reset tstamp_enabled */
2752 if (is_cgroup_event(event
))
2753 perf_cgroup_mark_enabled(event
, ctx
);
2755 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2756 if (group_sched_in(event
, cpuctx
, ctx
))
2763 ctx_sched_in(struct perf_event_context
*ctx
,
2764 struct perf_cpu_context
*cpuctx
,
2765 enum event_type_t event_type
,
2766 struct task_struct
*task
)
2768 int is_active
= ctx
->is_active
;
2771 lockdep_assert_held(&ctx
->lock
);
2773 if (likely(!ctx
->nr_events
))
2776 ctx
->is_active
|= event_type
;
2779 cpuctx
->task_ctx
= ctx
;
2781 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2785 ctx
->timestamp
= now
;
2786 perf_cgroup_set_timestamp(task
, ctx
);
2788 * First go through the list and put on any pinned groups
2789 * in order to give them the best chance of going on.
2791 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2792 ctx_pinned_sched_in(ctx
, cpuctx
);
2794 /* Then walk through the lower prio flexible groups */
2795 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2796 ctx_flexible_sched_in(ctx
, cpuctx
);
2799 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2800 enum event_type_t event_type
,
2801 struct task_struct
*task
)
2803 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2805 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2808 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2809 struct task_struct
*task
)
2811 struct perf_cpu_context
*cpuctx
;
2813 cpuctx
= __get_cpu_context(ctx
);
2814 if (cpuctx
->task_ctx
== ctx
)
2817 perf_ctx_lock(cpuctx
, ctx
);
2818 perf_pmu_disable(ctx
->pmu
);
2820 * We want to keep the following priority order:
2821 * cpu pinned (that don't need to move), task pinned,
2822 * cpu flexible, task flexible.
2824 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2825 perf_event_sched_in(cpuctx
, ctx
, task
);
2826 perf_pmu_enable(ctx
->pmu
);
2827 perf_ctx_unlock(cpuctx
, ctx
);
2831 * Called from scheduler to add the events of the current task
2832 * with interrupts disabled.
2834 * We restore the event value and then enable it.
2836 * This does not protect us against NMI, but enable()
2837 * sets the enabled bit in the control field of event _before_
2838 * accessing the event control register. If a NMI hits, then it will
2839 * keep the event running.
2841 void __perf_event_task_sched_in(struct task_struct
*prev
,
2842 struct task_struct
*task
)
2844 struct perf_event_context
*ctx
;
2848 * If cgroup events exist on this CPU, then we need to check if we have
2849 * to switch in PMU state; cgroup event are system-wide mode only.
2851 * Since cgroup events are CPU events, we must schedule these in before
2852 * we schedule in the task events.
2854 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2855 perf_cgroup_sched_in(prev
, task
);
2857 for_each_task_context_nr(ctxn
) {
2858 ctx
= task
->perf_event_ctxp
[ctxn
];
2862 perf_event_context_sched_in(ctx
, task
);
2865 if (atomic_read(&nr_switch_events
))
2866 perf_event_switch(task
, prev
, true);
2868 if (__this_cpu_read(perf_sched_cb_usages
))
2869 perf_pmu_sched_task(prev
, task
, true);
2872 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2874 u64 frequency
= event
->attr
.sample_freq
;
2875 u64 sec
= NSEC_PER_SEC
;
2876 u64 divisor
, dividend
;
2878 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2880 count_fls
= fls64(count
);
2881 nsec_fls
= fls64(nsec
);
2882 frequency_fls
= fls64(frequency
);
2886 * We got @count in @nsec, with a target of sample_freq HZ
2887 * the target period becomes:
2890 * period = -------------------
2891 * @nsec * sample_freq
2896 * Reduce accuracy by one bit such that @a and @b converge
2897 * to a similar magnitude.
2899 #define REDUCE_FLS(a, b) \
2901 if (a##_fls > b##_fls) { \
2911 * Reduce accuracy until either term fits in a u64, then proceed with
2912 * the other, so that finally we can do a u64/u64 division.
2914 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2915 REDUCE_FLS(nsec
, frequency
);
2916 REDUCE_FLS(sec
, count
);
2919 if (count_fls
+ sec_fls
> 64) {
2920 divisor
= nsec
* frequency
;
2922 while (count_fls
+ sec_fls
> 64) {
2923 REDUCE_FLS(count
, sec
);
2927 dividend
= count
* sec
;
2929 dividend
= count
* sec
;
2931 while (nsec_fls
+ frequency_fls
> 64) {
2932 REDUCE_FLS(nsec
, frequency
);
2936 divisor
= nsec
* frequency
;
2942 return div64_u64(dividend
, divisor
);
2945 static DEFINE_PER_CPU(int, perf_throttled_count
);
2946 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2948 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2950 struct hw_perf_event
*hwc
= &event
->hw
;
2951 s64 period
, sample_period
;
2954 period
= perf_calculate_period(event
, nsec
, count
);
2956 delta
= (s64
)(period
- hwc
->sample_period
);
2957 delta
= (delta
+ 7) / 8; /* low pass filter */
2959 sample_period
= hwc
->sample_period
+ delta
;
2964 hwc
->sample_period
= sample_period
;
2966 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2968 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2970 local64_set(&hwc
->period_left
, 0);
2973 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2978 * combine freq adjustment with unthrottling to avoid two passes over the
2979 * events. At the same time, make sure, having freq events does not change
2980 * the rate of unthrottling as that would introduce bias.
2982 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2985 struct perf_event
*event
;
2986 struct hw_perf_event
*hwc
;
2987 u64 now
, period
= TICK_NSEC
;
2991 * only need to iterate over all events iff:
2992 * - context have events in frequency mode (needs freq adjust)
2993 * - there are events to unthrottle on this cpu
2995 if (!(ctx
->nr_freq
|| needs_unthr
))
2998 raw_spin_lock(&ctx
->lock
);
2999 perf_pmu_disable(ctx
->pmu
);
3001 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3002 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3005 if (!event_filter_match(event
))
3008 perf_pmu_disable(event
->pmu
);
3012 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3013 hwc
->interrupts
= 0;
3014 perf_log_throttle(event
, 1);
3015 event
->pmu
->start(event
, 0);
3018 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3022 * stop the event and update event->count
3024 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3026 now
= local64_read(&event
->count
);
3027 delta
= now
- hwc
->freq_count_stamp
;
3028 hwc
->freq_count_stamp
= now
;
3032 * reload only if value has changed
3033 * we have stopped the event so tell that
3034 * to perf_adjust_period() to avoid stopping it
3038 perf_adjust_period(event
, period
, delta
, false);
3040 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3042 perf_pmu_enable(event
->pmu
);
3045 perf_pmu_enable(ctx
->pmu
);
3046 raw_spin_unlock(&ctx
->lock
);
3050 * Round-robin a context's events:
3052 static void rotate_ctx(struct perf_event_context
*ctx
)
3055 * Rotate the first entry last of non-pinned groups. Rotation might be
3056 * disabled by the inheritance code.
3058 if (!ctx
->rotate_disable
)
3059 list_rotate_left(&ctx
->flexible_groups
);
3062 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3064 struct perf_event_context
*ctx
= NULL
;
3067 if (cpuctx
->ctx
.nr_events
) {
3068 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3072 ctx
= cpuctx
->task_ctx
;
3073 if (ctx
&& ctx
->nr_events
) {
3074 if (ctx
->nr_events
!= ctx
->nr_active
)
3081 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3082 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3084 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3086 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3088 rotate_ctx(&cpuctx
->ctx
);
3092 perf_event_sched_in(cpuctx
, ctx
, current
);
3094 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3095 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3101 #ifdef CONFIG_NO_HZ_FULL
3102 bool perf_event_can_stop_tick(void)
3104 if (atomic_read(&nr_freq_events
) ||
3105 __this_cpu_read(perf_throttled_count
))
3112 void perf_event_task_tick(void)
3114 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3115 struct perf_event_context
*ctx
, *tmp
;
3118 WARN_ON(!irqs_disabled());
3120 __this_cpu_inc(perf_throttled_seq
);
3121 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3123 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3124 perf_adjust_freq_unthr_context(ctx
, throttled
);
3127 static int event_enable_on_exec(struct perf_event
*event
,
3128 struct perf_event_context
*ctx
)
3130 if (!event
->attr
.enable_on_exec
)
3133 event
->attr
.enable_on_exec
= 0;
3134 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3137 __perf_event_mark_enabled(event
);
3143 * Enable all of a task's events that have been marked enable-on-exec.
3144 * This expects task == current.
3146 static void perf_event_enable_on_exec(int ctxn
)
3148 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3149 struct perf_cpu_context
*cpuctx
;
3150 struct perf_event
*event
;
3151 unsigned long flags
;
3154 local_irq_save(flags
);
3155 ctx
= current
->perf_event_ctxp
[ctxn
];
3156 if (!ctx
|| !ctx
->nr_events
)
3159 cpuctx
= __get_cpu_context(ctx
);
3160 perf_ctx_lock(cpuctx
, ctx
);
3161 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
3162 enabled
|= event_enable_on_exec(event
, ctx
);
3165 * Unclone and reschedule this context if we enabled any event.
3168 clone_ctx
= unclone_ctx(ctx
);
3169 ctx_resched(cpuctx
, ctx
);
3171 perf_ctx_unlock(cpuctx
, ctx
);
3174 local_irq_restore(flags
);
3180 void perf_event_exec(void)
3185 for_each_task_context_nr(ctxn
)
3186 perf_event_enable_on_exec(ctxn
);
3190 struct perf_read_data
{
3191 struct perf_event
*event
;
3197 * Cross CPU call to read the hardware event
3199 static void __perf_event_read(void *info
)
3201 struct perf_read_data
*data
= info
;
3202 struct perf_event
*sub
, *event
= data
->event
;
3203 struct perf_event_context
*ctx
= event
->ctx
;
3204 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3205 struct pmu
*pmu
= event
->pmu
;
3208 * If this is a task context, we need to check whether it is
3209 * the current task context of this cpu. If not it has been
3210 * scheduled out before the smp call arrived. In that case
3211 * event->count would have been updated to a recent sample
3212 * when the event was scheduled out.
3214 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3217 raw_spin_lock(&ctx
->lock
);
3218 if (ctx
->is_active
) {
3219 update_context_time(ctx
);
3220 update_cgrp_time_from_event(event
);
3223 update_event_times(event
);
3224 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3233 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3237 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3238 update_event_times(sub
);
3239 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3241 * Use sibling's PMU rather than @event's since
3242 * sibling could be on different (eg: software) PMU.
3244 sub
->pmu
->read(sub
);
3248 data
->ret
= pmu
->commit_txn(pmu
);
3251 raw_spin_unlock(&ctx
->lock
);
3254 static inline u64
perf_event_count(struct perf_event
*event
)
3256 if (event
->pmu
->count
)
3257 return event
->pmu
->count(event
);
3259 return __perf_event_count(event
);
3263 * NMI-safe method to read a local event, that is an event that
3265 * - either for the current task, or for this CPU
3266 * - does not have inherit set, for inherited task events
3267 * will not be local and we cannot read them atomically
3268 * - must not have a pmu::count method
3270 u64
perf_event_read_local(struct perf_event
*event
)
3272 unsigned long flags
;
3276 * Disabling interrupts avoids all counter scheduling (context
3277 * switches, timer based rotation and IPIs).
3279 local_irq_save(flags
);
3281 /* If this is a per-task event, it must be for current */
3282 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3283 event
->hw
.target
!= current
);
3285 /* If this is a per-CPU event, it must be for this CPU */
3286 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3287 event
->cpu
!= smp_processor_id());
3290 * It must not be an event with inherit set, we cannot read
3291 * all child counters from atomic context.
3293 WARN_ON_ONCE(event
->attr
.inherit
);
3296 * It must not have a pmu::count method, those are not
3299 WARN_ON_ONCE(event
->pmu
->count
);
3302 * If the event is currently on this CPU, its either a per-task event,
3303 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3306 if (event
->oncpu
== smp_processor_id())
3307 event
->pmu
->read(event
);
3309 val
= local64_read(&event
->count
);
3310 local_irq_restore(flags
);
3315 static int perf_event_read(struct perf_event
*event
, bool group
)
3320 * If event is enabled and currently active on a CPU, update the
3321 * value in the event structure:
3323 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3324 struct perf_read_data data
= {
3329 smp_call_function_single(event
->oncpu
,
3330 __perf_event_read
, &data
, 1);
3332 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3333 struct perf_event_context
*ctx
= event
->ctx
;
3334 unsigned long flags
;
3336 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3338 * may read while context is not active
3339 * (e.g., thread is blocked), in that case
3340 * we cannot update context time
3342 if (ctx
->is_active
) {
3343 update_context_time(ctx
);
3344 update_cgrp_time_from_event(event
);
3347 update_group_times(event
);
3349 update_event_times(event
);
3350 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3357 * Initialize the perf_event context in a task_struct:
3359 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3361 raw_spin_lock_init(&ctx
->lock
);
3362 mutex_init(&ctx
->mutex
);
3363 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3364 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3365 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3366 INIT_LIST_HEAD(&ctx
->event_list
);
3367 atomic_set(&ctx
->refcount
, 1);
3368 INIT_DELAYED_WORK(&ctx
->orphans_remove
, orphans_remove_work
);
3371 static struct perf_event_context
*
3372 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3374 struct perf_event_context
*ctx
;
3376 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3380 __perf_event_init_context(ctx
);
3383 get_task_struct(task
);
3390 static struct task_struct
*
3391 find_lively_task_by_vpid(pid_t vpid
)
3393 struct task_struct
*task
;
3400 task
= find_task_by_vpid(vpid
);
3402 get_task_struct(task
);
3406 return ERR_PTR(-ESRCH
);
3408 /* Reuse ptrace permission checks for now. */
3410 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3415 put_task_struct(task
);
3416 return ERR_PTR(err
);
3421 * Returns a matching context with refcount and pincount.
3423 static struct perf_event_context
*
3424 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3425 struct perf_event
*event
)
3427 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3428 struct perf_cpu_context
*cpuctx
;
3429 void *task_ctx_data
= NULL
;
3430 unsigned long flags
;
3432 int cpu
= event
->cpu
;
3435 /* Must be root to operate on a CPU event: */
3436 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3437 return ERR_PTR(-EACCES
);
3440 * We could be clever and allow to attach a event to an
3441 * offline CPU and activate it when the CPU comes up, but
3444 if (!cpu_online(cpu
))
3445 return ERR_PTR(-ENODEV
);
3447 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3456 ctxn
= pmu
->task_ctx_nr
;
3460 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3461 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3462 if (!task_ctx_data
) {
3469 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3471 clone_ctx
= unclone_ctx(ctx
);
3474 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3475 ctx
->task_ctx_data
= task_ctx_data
;
3476 task_ctx_data
= NULL
;
3478 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3483 ctx
= alloc_perf_context(pmu
, task
);
3488 if (task_ctx_data
) {
3489 ctx
->task_ctx_data
= task_ctx_data
;
3490 task_ctx_data
= NULL
;
3494 mutex_lock(&task
->perf_event_mutex
);
3496 * If it has already passed perf_event_exit_task().
3497 * we must see PF_EXITING, it takes this mutex too.
3499 if (task
->flags
& PF_EXITING
)
3501 else if (task
->perf_event_ctxp
[ctxn
])
3506 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3508 mutex_unlock(&task
->perf_event_mutex
);
3510 if (unlikely(err
)) {
3519 kfree(task_ctx_data
);
3523 kfree(task_ctx_data
);
3524 return ERR_PTR(err
);
3527 static void perf_event_free_filter(struct perf_event
*event
);
3528 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3530 static void free_event_rcu(struct rcu_head
*head
)
3532 struct perf_event
*event
;
3534 event
= container_of(head
, struct perf_event
, rcu_head
);
3536 put_pid_ns(event
->ns
);
3537 perf_event_free_filter(event
);
3541 static void ring_buffer_attach(struct perf_event
*event
,
3542 struct ring_buffer
*rb
);
3544 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3549 if (is_cgroup_event(event
))
3550 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3553 static void unaccount_event(struct perf_event
*event
)
3560 if (event
->attach_state
& PERF_ATTACH_TASK
)
3562 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3563 atomic_dec(&nr_mmap_events
);
3564 if (event
->attr
.comm
)
3565 atomic_dec(&nr_comm_events
);
3566 if (event
->attr
.task
)
3567 atomic_dec(&nr_task_events
);
3568 if (event
->attr
.freq
)
3569 atomic_dec(&nr_freq_events
);
3570 if (event
->attr
.context_switch
) {
3572 atomic_dec(&nr_switch_events
);
3574 if (is_cgroup_event(event
))
3576 if (has_branch_stack(event
))
3580 static_key_slow_dec_deferred(&perf_sched_events
);
3582 unaccount_event_cpu(event
, event
->cpu
);
3586 * The following implement mutual exclusion of events on "exclusive" pmus
3587 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3588 * at a time, so we disallow creating events that might conflict, namely:
3590 * 1) cpu-wide events in the presence of per-task events,
3591 * 2) per-task events in the presence of cpu-wide events,
3592 * 3) two matching events on the same context.
3594 * The former two cases are handled in the allocation path (perf_event_alloc(),
3595 * _free_event()), the latter -- before the first perf_install_in_context().
3597 static int exclusive_event_init(struct perf_event
*event
)
3599 struct pmu
*pmu
= event
->pmu
;
3601 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3605 * Prevent co-existence of per-task and cpu-wide events on the
3606 * same exclusive pmu.
3608 * Negative pmu::exclusive_cnt means there are cpu-wide
3609 * events on this "exclusive" pmu, positive means there are
3612 * Since this is called in perf_event_alloc() path, event::ctx
3613 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3614 * to mean "per-task event", because unlike other attach states it
3615 * never gets cleared.
3617 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3618 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3621 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3628 static void exclusive_event_destroy(struct perf_event
*event
)
3630 struct pmu
*pmu
= event
->pmu
;
3632 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3635 /* see comment in exclusive_event_init() */
3636 if (event
->attach_state
& PERF_ATTACH_TASK
)
3637 atomic_dec(&pmu
->exclusive_cnt
);
3639 atomic_inc(&pmu
->exclusive_cnt
);
3642 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3644 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3645 (e1
->cpu
== e2
->cpu
||
3652 /* Called under the same ctx::mutex as perf_install_in_context() */
3653 static bool exclusive_event_installable(struct perf_event
*event
,
3654 struct perf_event_context
*ctx
)
3656 struct perf_event
*iter_event
;
3657 struct pmu
*pmu
= event
->pmu
;
3659 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3662 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3663 if (exclusive_event_match(iter_event
, event
))
3670 static void _free_event(struct perf_event
*event
)
3672 irq_work_sync(&event
->pending
);
3674 unaccount_event(event
);
3678 * Can happen when we close an event with re-directed output.
3680 * Since we have a 0 refcount, perf_mmap_close() will skip
3681 * over us; possibly making our ring_buffer_put() the last.
3683 mutex_lock(&event
->mmap_mutex
);
3684 ring_buffer_attach(event
, NULL
);
3685 mutex_unlock(&event
->mmap_mutex
);
3688 if (is_cgroup_event(event
))
3689 perf_detach_cgroup(event
);
3691 if (!event
->parent
) {
3692 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3693 put_callchain_buffers();
3696 perf_event_free_bpf_prog(event
);
3699 event
->destroy(event
);
3702 put_ctx(event
->ctx
);
3705 exclusive_event_destroy(event
);
3706 module_put(event
->pmu
->module
);
3709 call_rcu(&event
->rcu_head
, free_event_rcu
);
3713 * Used to free events which have a known refcount of 1, such as in error paths
3714 * where the event isn't exposed yet and inherited events.
3716 static void free_event(struct perf_event
*event
)
3718 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3719 "unexpected event refcount: %ld; ptr=%p\n",
3720 atomic_long_read(&event
->refcount
), event
)) {
3721 /* leak to avoid use-after-free */
3729 * Remove user event from the owner task.
3731 static void perf_remove_from_owner(struct perf_event
*event
)
3733 struct task_struct
*owner
;
3736 owner
= ACCESS_ONCE(event
->owner
);
3738 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3739 * !owner it means the list deletion is complete and we can indeed
3740 * free this event, otherwise we need to serialize on
3741 * owner->perf_event_mutex.
3743 smp_read_barrier_depends();
3746 * Since delayed_put_task_struct() also drops the last
3747 * task reference we can safely take a new reference
3748 * while holding the rcu_read_lock().
3750 get_task_struct(owner
);
3756 * If we're here through perf_event_exit_task() we're already
3757 * holding ctx->mutex which would be an inversion wrt. the
3758 * normal lock order.
3760 * However we can safely take this lock because its the child
3763 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3766 * We have to re-check the event->owner field, if it is cleared
3767 * we raced with perf_event_exit_task(), acquiring the mutex
3768 * ensured they're done, and we can proceed with freeing the
3772 list_del_init(&event
->owner_entry
);
3773 mutex_unlock(&owner
->perf_event_mutex
);
3774 put_task_struct(owner
);
3778 static void put_event(struct perf_event
*event
)
3780 struct perf_event_context
*ctx
;
3782 if (!atomic_long_dec_and_test(&event
->refcount
))
3785 if (!is_kernel_event(event
))
3786 perf_remove_from_owner(event
);
3789 * There are two ways this annotation is useful:
3791 * 1) there is a lock recursion from perf_event_exit_task
3792 * see the comment there.
3794 * 2) there is a lock-inversion with mmap_sem through
3795 * perf_read_group(), which takes faults while
3796 * holding ctx->mutex, however this is called after
3797 * the last filedesc died, so there is no possibility
3798 * to trigger the AB-BA case.
3800 ctx
= perf_event_ctx_lock_nested(event
, SINGLE_DEPTH_NESTING
);
3801 WARN_ON_ONCE(ctx
->parent_ctx
);
3802 perf_remove_from_context(event
, true);
3803 perf_event_ctx_unlock(event
, ctx
);
3808 int perf_event_release_kernel(struct perf_event
*event
)
3813 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3816 * Called when the last reference to the file is gone.
3818 static int perf_release(struct inode
*inode
, struct file
*file
)
3820 put_event(file
->private_data
);
3825 * Remove all orphanes events from the context.
3827 static void orphans_remove_work(struct work_struct
*work
)
3829 struct perf_event_context
*ctx
;
3830 struct perf_event
*event
, *tmp
;
3832 ctx
= container_of(work
, struct perf_event_context
,
3833 orphans_remove
.work
);
3835 mutex_lock(&ctx
->mutex
);
3836 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
) {
3837 struct perf_event
*parent_event
= event
->parent
;
3839 if (!is_orphaned_child(event
))
3842 perf_remove_from_context(event
, true);
3844 mutex_lock(&parent_event
->child_mutex
);
3845 list_del_init(&event
->child_list
);
3846 mutex_unlock(&parent_event
->child_mutex
);
3849 put_event(parent_event
);
3852 raw_spin_lock_irq(&ctx
->lock
);
3853 ctx
->orphans_remove_sched
= false;
3854 raw_spin_unlock_irq(&ctx
->lock
);
3855 mutex_unlock(&ctx
->mutex
);
3860 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3862 struct perf_event
*child
;
3868 mutex_lock(&event
->child_mutex
);
3870 (void)perf_event_read(event
, false);
3871 total
+= perf_event_count(event
);
3873 *enabled
+= event
->total_time_enabled
+
3874 atomic64_read(&event
->child_total_time_enabled
);
3875 *running
+= event
->total_time_running
+
3876 atomic64_read(&event
->child_total_time_running
);
3878 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3879 (void)perf_event_read(child
, false);
3880 total
+= perf_event_count(child
);
3881 *enabled
+= child
->total_time_enabled
;
3882 *running
+= child
->total_time_running
;
3884 mutex_unlock(&event
->child_mutex
);
3888 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3890 static int __perf_read_group_add(struct perf_event
*leader
,
3891 u64 read_format
, u64
*values
)
3893 struct perf_event
*sub
;
3894 int n
= 1; /* skip @nr */
3897 ret
= perf_event_read(leader
, true);
3902 * Since we co-schedule groups, {enabled,running} times of siblings
3903 * will be identical to those of the leader, so we only publish one
3906 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3907 values
[n
++] += leader
->total_time_enabled
+
3908 atomic64_read(&leader
->child_total_time_enabled
);
3911 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3912 values
[n
++] += leader
->total_time_running
+
3913 atomic64_read(&leader
->child_total_time_running
);
3917 * Write {count,id} tuples for every sibling.
3919 values
[n
++] += perf_event_count(leader
);
3920 if (read_format
& PERF_FORMAT_ID
)
3921 values
[n
++] = primary_event_id(leader
);
3923 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3924 values
[n
++] += perf_event_count(sub
);
3925 if (read_format
& PERF_FORMAT_ID
)
3926 values
[n
++] = primary_event_id(sub
);
3932 static int perf_read_group(struct perf_event
*event
,
3933 u64 read_format
, char __user
*buf
)
3935 struct perf_event
*leader
= event
->group_leader
, *child
;
3936 struct perf_event_context
*ctx
= leader
->ctx
;
3940 lockdep_assert_held(&ctx
->mutex
);
3942 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
3946 values
[0] = 1 + leader
->nr_siblings
;
3949 * By locking the child_mutex of the leader we effectively
3950 * lock the child list of all siblings.. XXX explain how.
3952 mutex_lock(&leader
->child_mutex
);
3954 ret
= __perf_read_group_add(leader
, read_format
, values
);
3958 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
3959 ret
= __perf_read_group_add(child
, read_format
, values
);
3964 mutex_unlock(&leader
->child_mutex
);
3966 ret
= event
->read_size
;
3967 if (copy_to_user(buf
, values
, event
->read_size
))
3972 mutex_unlock(&leader
->child_mutex
);
3978 static int perf_read_one(struct perf_event
*event
,
3979 u64 read_format
, char __user
*buf
)
3981 u64 enabled
, running
;
3985 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3986 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3987 values
[n
++] = enabled
;
3988 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3989 values
[n
++] = running
;
3990 if (read_format
& PERF_FORMAT_ID
)
3991 values
[n
++] = primary_event_id(event
);
3993 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3996 return n
* sizeof(u64
);
3999 static bool is_event_hup(struct perf_event
*event
)
4003 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
4006 mutex_lock(&event
->child_mutex
);
4007 no_children
= list_empty(&event
->child_list
);
4008 mutex_unlock(&event
->child_mutex
);
4013 * Read the performance event - simple non blocking version for now
4016 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4018 u64 read_format
= event
->attr
.read_format
;
4022 * Return end-of-file for a read on a event that is in
4023 * error state (i.e. because it was pinned but it couldn't be
4024 * scheduled on to the CPU at some point).
4026 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4029 if (count
< event
->read_size
)
4032 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4033 if (read_format
& PERF_FORMAT_GROUP
)
4034 ret
= perf_read_group(event
, read_format
, buf
);
4036 ret
= perf_read_one(event
, read_format
, buf
);
4042 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4044 struct perf_event
*event
= file
->private_data
;
4045 struct perf_event_context
*ctx
;
4048 ctx
= perf_event_ctx_lock(event
);
4049 ret
= __perf_read(event
, buf
, count
);
4050 perf_event_ctx_unlock(event
, ctx
);
4055 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4057 struct perf_event
*event
= file
->private_data
;
4058 struct ring_buffer
*rb
;
4059 unsigned int events
= POLLHUP
;
4061 poll_wait(file
, &event
->waitq
, wait
);
4063 if (is_event_hup(event
))
4067 * Pin the event->rb by taking event->mmap_mutex; otherwise
4068 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4070 mutex_lock(&event
->mmap_mutex
);
4073 events
= atomic_xchg(&rb
->poll
, 0);
4074 mutex_unlock(&event
->mmap_mutex
);
4078 static void _perf_event_reset(struct perf_event
*event
)
4080 (void)perf_event_read(event
, false);
4081 local64_set(&event
->count
, 0);
4082 perf_event_update_userpage(event
);
4086 * Holding the top-level event's child_mutex means that any
4087 * descendant process that has inherited this event will block
4088 * in sync_child_event if it goes to exit, thus satisfying the
4089 * task existence requirements of perf_event_enable/disable.
4091 static void perf_event_for_each_child(struct perf_event
*event
,
4092 void (*func
)(struct perf_event
*))
4094 struct perf_event
*child
;
4096 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4098 mutex_lock(&event
->child_mutex
);
4100 list_for_each_entry(child
, &event
->child_list
, child_list
)
4102 mutex_unlock(&event
->child_mutex
);
4105 static void perf_event_for_each(struct perf_event
*event
,
4106 void (*func
)(struct perf_event
*))
4108 struct perf_event_context
*ctx
= event
->ctx
;
4109 struct perf_event
*sibling
;
4111 lockdep_assert_held(&ctx
->mutex
);
4113 event
= event
->group_leader
;
4115 perf_event_for_each_child(event
, func
);
4116 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4117 perf_event_for_each_child(sibling
, func
);
4120 static void __perf_event_period(struct perf_event
*event
,
4121 struct perf_cpu_context
*cpuctx
,
4122 struct perf_event_context
*ctx
,
4125 u64 value
= *((u64
*)info
);
4128 if (event
->attr
.freq
) {
4129 event
->attr
.sample_freq
= value
;
4131 event
->attr
.sample_period
= value
;
4132 event
->hw
.sample_period
= value
;
4135 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4137 perf_pmu_disable(ctx
->pmu
);
4138 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4141 local64_set(&event
->hw
.period_left
, 0);
4144 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4145 perf_pmu_enable(ctx
->pmu
);
4149 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4153 if (!is_sampling_event(event
))
4156 if (copy_from_user(&value
, arg
, sizeof(value
)))
4162 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4165 event_function_call(event
, __perf_event_period
, &value
);
4170 static const struct file_operations perf_fops
;
4172 static inline int perf_fget_light(int fd
, struct fd
*p
)
4174 struct fd f
= fdget(fd
);
4178 if (f
.file
->f_op
!= &perf_fops
) {
4186 static int perf_event_set_output(struct perf_event
*event
,
4187 struct perf_event
*output_event
);
4188 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4189 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4191 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4193 void (*func
)(struct perf_event
*);
4197 case PERF_EVENT_IOC_ENABLE
:
4198 func
= _perf_event_enable
;
4200 case PERF_EVENT_IOC_DISABLE
:
4201 func
= _perf_event_disable
;
4203 case PERF_EVENT_IOC_RESET
:
4204 func
= _perf_event_reset
;
4207 case PERF_EVENT_IOC_REFRESH
:
4208 return _perf_event_refresh(event
, arg
);
4210 case PERF_EVENT_IOC_PERIOD
:
4211 return perf_event_period(event
, (u64 __user
*)arg
);
4213 case PERF_EVENT_IOC_ID
:
4215 u64 id
= primary_event_id(event
);
4217 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4222 case PERF_EVENT_IOC_SET_OUTPUT
:
4226 struct perf_event
*output_event
;
4228 ret
= perf_fget_light(arg
, &output
);
4231 output_event
= output
.file
->private_data
;
4232 ret
= perf_event_set_output(event
, output_event
);
4235 ret
= perf_event_set_output(event
, NULL
);
4240 case PERF_EVENT_IOC_SET_FILTER
:
4241 return perf_event_set_filter(event
, (void __user
*)arg
);
4243 case PERF_EVENT_IOC_SET_BPF
:
4244 return perf_event_set_bpf_prog(event
, arg
);
4250 if (flags
& PERF_IOC_FLAG_GROUP
)
4251 perf_event_for_each(event
, func
);
4253 perf_event_for_each_child(event
, func
);
4258 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4260 struct perf_event
*event
= file
->private_data
;
4261 struct perf_event_context
*ctx
;
4264 ctx
= perf_event_ctx_lock(event
);
4265 ret
= _perf_ioctl(event
, cmd
, arg
);
4266 perf_event_ctx_unlock(event
, ctx
);
4271 #ifdef CONFIG_COMPAT
4272 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4275 switch (_IOC_NR(cmd
)) {
4276 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4277 case _IOC_NR(PERF_EVENT_IOC_ID
):
4278 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4279 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4280 cmd
&= ~IOCSIZE_MASK
;
4281 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4285 return perf_ioctl(file
, cmd
, arg
);
4288 # define perf_compat_ioctl NULL
4291 int perf_event_task_enable(void)
4293 struct perf_event_context
*ctx
;
4294 struct perf_event
*event
;
4296 mutex_lock(¤t
->perf_event_mutex
);
4297 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4298 ctx
= perf_event_ctx_lock(event
);
4299 perf_event_for_each_child(event
, _perf_event_enable
);
4300 perf_event_ctx_unlock(event
, ctx
);
4302 mutex_unlock(¤t
->perf_event_mutex
);
4307 int perf_event_task_disable(void)
4309 struct perf_event_context
*ctx
;
4310 struct perf_event
*event
;
4312 mutex_lock(¤t
->perf_event_mutex
);
4313 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4314 ctx
= perf_event_ctx_lock(event
);
4315 perf_event_for_each_child(event
, _perf_event_disable
);
4316 perf_event_ctx_unlock(event
, ctx
);
4318 mutex_unlock(¤t
->perf_event_mutex
);
4323 static int perf_event_index(struct perf_event
*event
)
4325 if (event
->hw
.state
& PERF_HES_STOPPED
)
4328 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4331 return event
->pmu
->event_idx(event
);
4334 static void calc_timer_values(struct perf_event
*event
,
4341 *now
= perf_clock();
4342 ctx_time
= event
->shadow_ctx_time
+ *now
;
4343 *enabled
= ctx_time
- event
->tstamp_enabled
;
4344 *running
= ctx_time
- event
->tstamp_running
;
4347 static void perf_event_init_userpage(struct perf_event
*event
)
4349 struct perf_event_mmap_page
*userpg
;
4350 struct ring_buffer
*rb
;
4353 rb
= rcu_dereference(event
->rb
);
4357 userpg
= rb
->user_page
;
4359 /* Allow new userspace to detect that bit 0 is deprecated */
4360 userpg
->cap_bit0_is_deprecated
= 1;
4361 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4362 userpg
->data_offset
= PAGE_SIZE
;
4363 userpg
->data_size
= perf_data_size(rb
);
4369 void __weak
arch_perf_update_userpage(
4370 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4375 * Callers need to ensure there can be no nesting of this function, otherwise
4376 * the seqlock logic goes bad. We can not serialize this because the arch
4377 * code calls this from NMI context.
4379 void perf_event_update_userpage(struct perf_event
*event
)
4381 struct perf_event_mmap_page
*userpg
;
4382 struct ring_buffer
*rb
;
4383 u64 enabled
, running
, now
;
4386 rb
= rcu_dereference(event
->rb
);
4391 * compute total_time_enabled, total_time_running
4392 * based on snapshot values taken when the event
4393 * was last scheduled in.
4395 * we cannot simply called update_context_time()
4396 * because of locking issue as we can be called in
4399 calc_timer_values(event
, &now
, &enabled
, &running
);
4401 userpg
= rb
->user_page
;
4403 * Disable preemption so as to not let the corresponding user-space
4404 * spin too long if we get preempted.
4409 userpg
->index
= perf_event_index(event
);
4410 userpg
->offset
= perf_event_count(event
);
4412 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4414 userpg
->time_enabled
= enabled
+
4415 atomic64_read(&event
->child_total_time_enabled
);
4417 userpg
->time_running
= running
+
4418 atomic64_read(&event
->child_total_time_running
);
4420 arch_perf_update_userpage(event
, userpg
, now
);
4429 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4431 struct perf_event
*event
= vma
->vm_file
->private_data
;
4432 struct ring_buffer
*rb
;
4433 int ret
= VM_FAULT_SIGBUS
;
4435 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4436 if (vmf
->pgoff
== 0)
4442 rb
= rcu_dereference(event
->rb
);
4446 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4449 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4453 get_page(vmf
->page
);
4454 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4455 vmf
->page
->index
= vmf
->pgoff
;
4464 static void ring_buffer_attach(struct perf_event
*event
,
4465 struct ring_buffer
*rb
)
4467 struct ring_buffer
*old_rb
= NULL
;
4468 unsigned long flags
;
4472 * Should be impossible, we set this when removing
4473 * event->rb_entry and wait/clear when adding event->rb_entry.
4475 WARN_ON_ONCE(event
->rcu_pending
);
4478 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4479 list_del_rcu(&event
->rb_entry
);
4480 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4482 event
->rcu_batches
= get_state_synchronize_rcu();
4483 event
->rcu_pending
= 1;
4487 if (event
->rcu_pending
) {
4488 cond_synchronize_rcu(event
->rcu_batches
);
4489 event
->rcu_pending
= 0;
4492 spin_lock_irqsave(&rb
->event_lock
, flags
);
4493 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4494 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4497 rcu_assign_pointer(event
->rb
, rb
);
4500 ring_buffer_put(old_rb
);
4502 * Since we detached before setting the new rb, so that we
4503 * could attach the new rb, we could have missed a wakeup.
4506 wake_up_all(&event
->waitq
);
4510 static void ring_buffer_wakeup(struct perf_event
*event
)
4512 struct ring_buffer
*rb
;
4515 rb
= rcu_dereference(event
->rb
);
4517 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4518 wake_up_all(&event
->waitq
);
4523 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4525 struct ring_buffer
*rb
;
4528 rb
= rcu_dereference(event
->rb
);
4530 if (!atomic_inc_not_zero(&rb
->refcount
))
4538 void ring_buffer_put(struct ring_buffer
*rb
)
4540 if (!atomic_dec_and_test(&rb
->refcount
))
4543 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4545 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4548 static void perf_mmap_open(struct vm_area_struct
*vma
)
4550 struct perf_event
*event
= vma
->vm_file
->private_data
;
4552 atomic_inc(&event
->mmap_count
);
4553 atomic_inc(&event
->rb
->mmap_count
);
4556 atomic_inc(&event
->rb
->aux_mmap_count
);
4558 if (event
->pmu
->event_mapped
)
4559 event
->pmu
->event_mapped(event
);
4563 * A buffer can be mmap()ed multiple times; either directly through the same
4564 * event, or through other events by use of perf_event_set_output().
4566 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4567 * the buffer here, where we still have a VM context. This means we need
4568 * to detach all events redirecting to us.
4570 static void perf_mmap_close(struct vm_area_struct
*vma
)
4572 struct perf_event
*event
= vma
->vm_file
->private_data
;
4574 struct ring_buffer
*rb
= ring_buffer_get(event
);
4575 struct user_struct
*mmap_user
= rb
->mmap_user
;
4576 int mmap_locked
= rb
->mmap_locked
;
4577 unsigned long size
= perf_data_size(rb
);
4579 if (event
->pmu
->event_unmapped
)
4580 event
->pmu
->event_unmapped(event
);
4583 * rb->aux_mmap_count will always drop before rb->mmap_count and
4584 * event->mmap_count, so it is ok to use event->mmap_mutex to
4585 * serialize with perf_mmap here.
4587 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4588 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4589 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4590 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4593 mutex_unlock(&event
->mmap_mutex
);
4596 atomic_dec(&rb
->mmap_count
);
4598 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4601 ring_buffer_attach(event
, NULL
);
4602 mutex_unlock(&event
->mmap_mutex
);
4604 /* If there's still other mmap()s of this buffer, we're done. */
4605 if (atomic_read(&rb
->mmap_count
))
4609 * No other mmap()s, detach from all other events that might redirect
4610 * into the now unreachable buffer. Somewhat complicated by the
4611 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4615 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4616 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4618 * This event is en-route to free_event() which will
4619 * detach it and remove it from the list.
4625 mutex_lock(&event
->mmap_mutex
);
4627 * Check we didn't race with perf_event_set_output() which can
4628 * swizzle the rb from under us while we were waiting to
4629 * acquire mmap_mutex.
4631 * If we find a different rb; ignore this event, a next
4632 * iteration will no longer find it on the list. We have to
4633 * still restart the iteration to make sure we're not now
4634 * iterating the wrong list.
4636 if (event
->rb
== rb
)
4637 ring_buffer_attach(event
, NULL
);
4639 mutex_unlock(&event
->mmap_mutex
);
4643 * Restart the iteration; either we're on the wrong list or
4644 * destroyed its integrity by doing a deletion.
4651 * It could be there's still a few 0-ref events on the list; they'll
4652 * get cleaned up by free_event() -- they'll also still have their
4653 * ref on the rb and will free it whenever they are done with it.
4655 * Aside from that, this buffer is 'fully' detached and unmapped,
4656 * undo the VM accounting.
4659 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4660 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4661 free_uid(mmap_user
);
4664 ring_buffer_put(rb
); /* could be last */
4667 static const struct vm_operations_struct perf_mmap_vmops
= {
4668 .open
= perf_mmap_open
,
4669 .close
= perf_mmap_close
, /* non mergable */
4670 .fault
= perf_mmap_fault
,
4671 .page_mkwrite
= perf_mmap_fault
,
4674 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4676 struct perf_event
*event
= file
->private_data
;
4677 unsigned long user_locked
, user_lock_limit
;
4678 struct user_struct
*user
= current_user();
4679 unsigned long locked
, lock_limit
;
4680 struct ring_buffer
*rb
= NULL
;
4681 unsigned long vma_size
;
4682 unsigned long nr_pages
;
4683 long user_extra
= 0, extra
= 0;
4684 int ret
= 0, flags
= 0;
4687 * Don't allow mmap() of inherited per-task counters. This would
4688 * create a performance issue due to all children writing to the
4691 if (event
->cpu
== -1 && event
->attr
.inherit
)
4694 if (!(vma
->vm_flags
& VM_SHARED
))
4697 vma_size
= vma
->vm_end
- vma
->vm_start
;
4699 if (vma
->vm_pgoff
== 0) {
4700 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4703 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4704 * mapped, all subsequent mappings should have the same size
4705 * and offset. Must be above the normal perf buffer.
4707 u64 aux_offset
, aux_size
;
4712 nr_pages
= vma_size
/ PAGE_SIZE
;
4714 mutex_lock(&event
->mmap_mutex
);
4721 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4722 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4724 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4727 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4730 /* already mapped with a different offset */
4731 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4734 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4737 /* already mapped with a different size */
4738 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4741 if (!is_power_of_2(nr_pages
))
4744 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4747 if (rb_has_aux(rb
)) {
4748 atomic_inc(&rb
->aux_mmap_count
);
4753 atomic_set(&rb
->aux_mmap_count
, 1);
4754 user_extra
= nr_pages
;
4760 * If we have rb pages ensure they're a power-of-two number, so we
4761 * can do bitmasks instead of modulo.
4763 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4766 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4769 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4771 mutex_lock(&event
->mmap_mutex
);
4773 if (event
->rb
->nr_pages
!= nr_pages
) {
4778 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4780 * Raced against perf_mmap_close() through
4781 * perf_event_set_output(). Try again, hope for better
4784 mutex_unlock(&event
->mmap_mutex
);
4791 user_extra
= nr_pages
+ 1;
4794 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4797 * Increase the limit linearly with more CPUs:
4799 user_lock_limit
*= num_online_cpus();
4801 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4803 if (user_locked
> user_lock_limit
)
4804 extra
= user_locked
- user_lock_limit
;
4806 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4807 lock_limit
>>= PAGE_SHIFT
;
4808 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4810 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4811 !capable(CAP_IPC_LOCK
)) {
4816 WARN_ON(!rb
&& event
->rb
);
4818 if (vma
->vm_flags
& VM_WRITE
)
4819 flags
|= RING_BUFFER_WRITABLE
;
4822 rb
= rb_alloc(nr_pages
,
4823 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4831 atomic_set(&rb
->mmap_count
, 1);
4832 rb
->mmap_user
= get_current_user();
4833 rb
->mmap_locked
= extra
;
4835 ring_buffer_attach(event
, rb
);
4837 perf_event_init_userpage(event
);
4838 perf_event_update_userpage(event
);
4840 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4841 event
->attr
.aux_watermark
, flags
);
4843 rb
->aux_mmap_locked
= extra
;
4848 atomic_long_add(user_extra
, &user
->locked_vm
);
4849 vma
->vm_mm
->pinned_vm
+= extra
;
4851 atomic_inc(&event
->mmap_count
);
4853 atomic_dec(&rb
->mmap_count
);
4856 mutex_unlock(&event
->mmap_mutex
);
4859 * Since pinned accounting is per vm we cannot allow fork() to copy our
4862 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4863 vma
->vm_ops
= &perf_mmap_vmops
;
4865 if (event
->pmu
->event_mapped
)
4866 event
->pmu
->event_mapped(event
);
4871 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4873 struct inode
*inode
= file_inode(filp
);
4874 struct perf_event
*event
= filp
->private_data
;
4877 mutex_lock(&inode
->i_mutex
);
4878 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4879 mutex_unlock(&inode
->i_mutex
);
4887 static const struct file_operations perf_fops
= {
4888 .llseek
= no_llseek
,
4889 .release
= perf_release
,
4892 .unlocked_ioctl
= perf_ioctl
,
4893 .compat_ioctl
= perf_compat_ioctl
,
4895 .fasync
= perf_fasync
,
4901 * If there's data, ensure we set the poll() state and publish everything
4902 * to user-space before waking everybody up.
4905 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
4907 /* only the parent has fasync state */
4909 event
= event
->parent
;
4910 return &event
->fasync
;
4913 void perf_event_wakeup(struct perf_event
*event
)
4915 ring_buffer_wakeup(event
);
4917 if (event
->pending_kill
) {
4918 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
4919 event
->pending_kill
= 0;
4923 static void perf_pending_event(struct irq_work
*entry
)
4925 struct perf_event
*event
= container_of(entry
,
4926 struct perf_event
, pending
);
4929 rctx
= perf_swevent_get_recursion_context();
4931 * If we 'fail' here, that's OK, it means recursion is already disabled
4932 * and we won't recurse 'further'.
4935 if (event
->pending_disable
) {
4936 event
->pending_disable
= 0;
4937 perf_event_disable_local(event
);
4940 if (event
->pending_wakeup
) {
4941 event
->pending_wakeup
= 0;
4942 perf_event_wakeup(event
);
4946 perf_swevent_put_recursion_context(rctx
);
4950 * We assume there is only KVM supporting the callbacks.
4951 * Later on, we might change it to a list if there is
4952 * another virtualization implementation supporting the callbacks.
4954 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4956 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4958 perf_guest_cbs
= cbs
;
4961 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4963 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4965 perf_guest_cbs
= NULL
;
4968 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4971 perf_output_sample_regs(struct perf_output_handle
*handle
,
4972 struct pt_regs
*regs
, u64 mask
)
4976 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4977 sizeof(mask
) * BITS_PER_BYTE
) {
4980 val
= perf_reg_value(regs
, bit
);
4981 perf_output_put(handle
, val
);
4985 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
4986 struct pt_regs
*regs
,
4987 struct pt_regs
*regs_user_copy
)
4989 if (user_mode(regs
)) {
4990 regs_user
->abi
= perf_reg_abi(current
);
4991 regs_user
->regs
= regs
;
4992 } else if (current
->mm
) {
4993 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
4995 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
4996 regs_user
->regs
= NULL
;
5000 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5001 struct pt_regs
*regs
)
5003 regs_intr
->regs
= regs
;
5004 regs_intr
->abi
= perf_reg_abi(current
);
5009 * Get remaining task size from user stack pointer.
5011 * It'd be better to take stack vma map and limit this more
5012 * precisly, but there's no way to get it safely under interrupt,
5013 * so using TASK_SIZE as limit.
5015 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5017 unsigned long addr
= perf_user_stack_pointer(regs
);
5019 if (!addr
|| addr
>= TASK_SIZE
)
5022 return TASK_SIZE
- addr
;
5026 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5027 struct pt_regs
*regs
)
5031 /* No regs, no stack pointer, no dump. */
5036 * Check if we fit in with the requested stack size into the:
5038 * If we don't, we limit the size to the TASK_SIZE.
5040 * - remaining sample size
5041 * If we don't, we customize the stack size to
5042 * fit in to the remaining sample size.
5045 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5046 stack_size
= min(stack_size
, (u16
) task_size
);
5048 /* Current header size plus static size and dynamic size. */
5049 header_size
+= 2 * sizeof(u64
);
5051 /* Do we fit in with the current stack dump size? */
5052 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5054 * If we overflow the maximum size for the sample,
5055 * we customize the stack dump size to fit in.
5057 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5058 stack_size
= round_up(stack_size
, sizeof(u64
));
5065 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5066 struct pt_regs
*regs
)
5068 /* Case of a kernel thread, nothing to dump */
5071 perf_output_put(handle
, size
);
5080 * - the size requested by user or the best one we can fit
5081 * in to the sample max size
5083 * - user stack dump data
5085 * - the actual dumped size
5089 perf_output_put(handle
, dump_size
);
5092 sp
= perf_user_stack_pointer(regs
);
5093 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5094 dyn_size
= dump_size
- rem
;
5096 perf_output_skip(handle
, rem
);
5099 perf_output_put(handle
, dyn_size
);
5103 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5104 struct perf_sample_data
*data
,
5105 struct perf_event
*event
)
5107 u64 sample_type
= event
->attr
.sample_type
;
5109 data
->type
= sample_type
;
5110 header
->size
+= event
->id_header_size
;
5112 if (sample_type
& PERF_SAMPLE_TID
) {
5113 /* namespace issues */
5114 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5115 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5118 if (sample_type
& PERF_SAMPLE_TIME
)
5119 data
->time
= perf_event_clock(event
);
5121 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5122 data
->id
= primary_event_id(event
);
5124 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5125 data
->stream_id
= event
->id
;
5127 if (sample_type
& PERF_SAMPLE_CPU
) {
5128 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5129 data
->cpu_entry
.reserved
= 0;
5133 void perf_event_header__init_id(struct perf_event_header
*header
,
5134 struct perf_sample_data
*data
,
5135 struct perf_event
*event
)
5137 if (event
->attr
.sample_id_all
)
5138 __perf_event_header__init_id(header
, data
, event
);
5141 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5142 struct perf_sample_data
*data
)
5144 u64 sample_type
= data
->type
;
5146 if (sample_type
& PERF_SAMPLE_TID
)
5147 perf_output_put(handle
, data
->tid_entry
);
5149 if (sample_type
& PERF_SAMPLE_TIME
)
5150 perf_output_put(handle
, data
->time
);
5152 if (sample_type
& PERF_SAMPLE_ID
)
5153 perf_output_put(handle
, data
->id
);
5155 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5156 perf_output_put(handle
, data
->stream_id
);
5158 if (sample_type
& PERF_SAMPLE_CPU
)
5159 perf_output_put(handle
, data
->cpu_entry
);
5161 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5162 perf_output_put(handle
, data
->id
);
5165 void perf_event__output_id_sample(struct perf_event
*event
,
5166 struct perf_output_handle
*handle
,
5167 struct perf_sample_data
*sample
)
5169 if (event
->attr
.sample_id_all
)
5170 __perf_event__output_id_sample(handle
, sample
);
5173 static void perf_output_read_one(struct perf_output_handle
*handle
,
5174 struct perf_event
*event
,
5175 u64 enabled
, u64 running
)
5177 u64 read_format
= event
->attr
.read_format
;
5181 values
[n
++] = perf_event_count(event
);
5182 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5183 values
[n
++] = enabled
+
5184 atomic64_read(&event
->child_total_time_enabled
);
5186 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5187 values
[n
++] = running
+
5188 atomic64_read(&event
->child_total_time_running
);
5190 if (read_format
& PERF_FORMAT_ID
)
5191 values
[n
++] = primary_event_id(event
);
5193 __output_copy(handle
, values
, n
* sizeof(u64
));
5197 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5199 static void perf_output_read_group(struct perf_output_handle
*handle
,
5200 struct perf_event
*event
,
5201 u64 enabled
, u64 running
)
5203 struct perf_event
*leader
= event
->group_leader
, *sub
;
5204 u64 read_format
= event
->attr
.read_format
;
5208 values
[n
++] = 1 + leader
->nr_siblings
;
5210 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5211 values
[n
++] = enabled
;
5213 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5214 values
[n
++] = running
;
5216 if (leader
!= event
)
5217 leader
->pmu
->read(leader
);
5219 values
[n
++] = perf_event_count(leader
);
5220 if (read_format
& PERF_FORMAT_ID
)
5221 values
[n
++] = primary_event_id(leader
);
5223 __output_copy(handle
, values
, n
* sizeof(u64
));
5225 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5228 if ((sub
!= event
) &&
5229 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5230 sub
->pmu
->read(sub
);
5232 values
[n
++] = perf_event_count(sub
);
5233 if (read_format
& PERF_FORMAT_ID
)
5234 values
[n
++] = primary_event_id(sub
);
5236 __output_copy(handle
, values
, n
* sizeof(u64
));
5240 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5241 PERF_FORMAT_TOTAL_TIME_RUNNING)
5243 static void perf_output_read(struct perf_output_handle
*handle
,
5244 struct perf_event
*event
)
5246 u64 enabled
= 0, running
= 0, now
;
5247 u64 read_format
= event
->attr
.read_format
;
5250 * compute total_time_enabled, total_time_running
5251 * based on snapshot values taken when the event
5252 * was last scheduled in.
5254 * we cannot simply called update_context_time()
5255 * because of locking issue as we are called in
5258 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5259 calc_timer_values(event
, &now
, &enabled
, &running
);
5261 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5262 perf_output_read_group(handle
, event
, enabled
, running
);
5264 perf_output_read_one(handle
, event
, enabled
, running
);
5267 void perf_output_sample(struct perf_output_handle
*handle
,
5268 struct perf_event_header
*header
,
5269 struct perf_sample_data
*data
,
5270 struct perf_event
*event
)
5272 u64 sample_type
= data
->type
;
5274 perf_output_put(handle
, *header
);
5276 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5277 perf_output_put(handle
, data
->id
);
5279 if (sample_type
& PERF_SAMPLE_IP
)
5280 perf_output_put(handle
, data
->ip
);
5282 if (sample_type
& PERF_SAMPLE_TID
)
5283 perf_output_put(handle
, data
->tid_entry
);
5285 if (sample_type
& PERF_SAMPLE_TIME
)
5286 perf_output_put(handle
, data
->time
);
5288 if (sample_type
& PERF_SAMPLE_ADDR
)
5289 perf_output_put(handle
, data
->addr
);
5291 if (sample_type
& PERF_SAMPLE_ID
)
5292 perf_output_put(handle
, data
->id
);
5294 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5295 perf_output_put(handle
, data
->stream_id
);
5297 if (sample_type
& PERF_SAMPLE_CPU
)
5298 perf_output_put(handle
, data
->cpu_entry
);
5300 if (sample_type
& PERF_SAMPLE_PERIOD
)
5301 perf_output_put(handle
, data
->period
);
5303 if (sample_type
& PERF_SAMPLE_READ
)
5304 perf_output_read(handle
, event
);
5306 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5307 if (data
->callchain
) {
5310 if (data
->callchain
)
5311 size
+= data
->callchain
->nr
;
5313 size
*= sizeof(u64
);
5315 __output_copy(handle
, data
->callchain
, size
);
5318 perf_output_put(handle
, nr
);
5322 if (sample_type
& PERF_SAMPLE_RAW
) {
5324 u32 raw_size
= data
->raw
->size
;
5325 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5326 sizeof(u64
)) - sizeof(u32
);
5329 perf_output_put(handle
, real_size
);
5330 __output_copy(handle
, data
->raw
->data
, raw_size
);
5331 if (real_size
- raw_size
)
5332 __output_copy(handle
, &zero
, real_size
- raw_size
);
5338 .size
= sizeof(u32
),
5341 perf_output_put(handle
, raw
);
5345 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5346 if (data
->br_stack
) {
5349 size
= data
->br_stack
->nr
5350 * sizeof(struct perf_branch_entry
);
5352 perf_output_put(handle
, data
->br_stack
->nr
);
5353 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5356 * we always store at least the value of nr
5359 perf_output_put(handle
, nr
);
5363 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5364 u64 abi
= data
->regs_user
.abi
;
5367 * If there are no regs to dump, notice it through
5368 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5370 perf_output_put(handle
, abi
);
5373 u64 mask
= event
->attr
.sample_regs_user
;
5374 perf_output_sample_regs(handle
,
5375 data
->regs_user
.regs
,
5380 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5381 perf_output_sample_ustack(handle
,
5382 data
->stack_user_size
,
5383 data
->regs_user
.regs
);
5386 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5387 perf_output_put(handle
, data
->weight
);
5389 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5390 perf_output_put(handle
, data
->data_src
.val
);
5392 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5393 perf_output_put(handle
, data
->txn
);
5395 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5396 u64 abi
= data
->regs_intr
.abi
;
5398 * If there are no regs to dump, notice it through
5399 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5401 perf_output_put(handle
, abi
);
5404 u64 mask
= event
->attr
.sample_regs_intr
;
5406 perf_output_sample_regs(handle
,
5407 data
->regs_intr
.regs
,
5412 if (!event
->attr
.watermark
) {
5413 int wakeup_events
= event
->attr
.wakeup_events
;
5415 if (wakeup_events
) {
5416 struct ring_buffer
*rb
= handle
->rb
;
5417 int events
= local_inc_return(&rb
->events
);
5419 if (events
>= wakeup_events
) {
5420 local_sub(wakeup_events
, &rb
->events
);
5421 local_inc(&rb
->wakeup
);
5427 void perf_prepare_sample(struct perf_event_header
*header
,
5428 struct perf_sample_data
*data
,
5429 struct perf_event
*event
,
5430 struct pt_regs
*regs
)
5432 u64 sample_type
= event
->attr
.sample_type
;
5434 header
->type
= PERF_RECORD_SAMPLE
;
5435 header
->size
= sizeof(*header
) + event
->header_size
;
5438 header
->misc
|= perf_misc_flags(regs
);
5440 __perf_event_header__init_id(header
, data
, event
);
5442 if (sample_type
& PERF_SAMPLE_IP
)
5443 data
->ip
= perf_instruction_pointer(regs
);
5445 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5448 data
->callchain
= perf_callchain(event
, regs
);
5450 if (data
->callchain
)
5451 size
+= data
->callchain
->nr
;
5453 header
->size
+= size
* sizeof(u64
);
5456 if (sample_type
& PERF_SAMPLE_RAW
) {
5457 int size
= sizeof(u32
);
5460 size
+= data
->raw
->size
;
5462 size
+= sizeof(u32
);
5464 header
->size
+= round_up(size
, sizeof(u64
));
5467 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5468 int size
= sizeof(u64
); /* nr */
5469 if (data
->br_stack
) {
5470 size
+= data
->br_stack
->nr
5471 * sizeof(struct perf_branch_entry
);
5473 header
->size
+= size
;
5476 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5477 perf_sample_regs_user(&data
->regs_user
, regs
,
5478 &data
->regs_user_copy
);
5480 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5481 /* regs dump ABI info */
5482 int size
= sizeof(u64
);
5484 if (data
->regs_user
.regs
) {
5485 u64 mask
= event
->attr
.sample_regs_user
;
5486 size
+= hweight64(mask
) * sizeof(u64
);
5489 header
->size
+= size
;
5492 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5494 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5495 * processed as the last one or have additional check added
5496 * in case new sample type is added, because we could eat
5497 * up the rest of the sample size.
5499 u16 stack_size
= event
->attr
.sample_stack_user
;
5500 u16 size
= sizeof(u64
);
5502 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5503 data
->regs_user
.regs
);
5506 * If there is something to dump, add space for the dump
5507 * itself and for the field that tells the dynamic size,
5508 * which is how many have been actually dumped.
5511 size
+= sizeof(u64
) + stack_size
;
5513 data
->stack_user_size
= stack_size
;
5514 header
->size
+= size
;
5517 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5518 /* regs dump ABI info */
5519 int size
= sizeof(u64
);
5521 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5523 if (data
->regs_intr
.regs
) {
5524 u64 mask
= event
->attr
.sample_regs_intr
;
5526 size
+= hweight64(mask
) * sizeof(u64
);
5529 header
->size
+= size
;
5533 void perf_event_output(struct perf_event
*event
,
5534 struct perf_sample_data
*data
,
5535 struct pt_regs
*regs
)
5537 struct perf_output_handle handle
;
5538 struct perf_event_header header
;
5540 /* protect the callchain buffers */
5543 perf_prepare_sample(&header
, data
, event
, regs
);
5545 if (perf_output_begin(&handle
, event
, header
.size
))
5548 perf_output_sample(&handle
, &header
, data
, event
);
5550 perf_output_end(&handle
);
5560 struct perf_read_event
{
5561 struct perf_event_header header
;
5568 perf_event_read_event(struct perf_event
*event
,
5569 struct task_struct
*task
)
5571 struct perf_output_handle handle
;
5572 struct perf_sample_data sample
;
5573 struct perf_read_event read_event
= {
5575 .type
= PERF_RECORD_READ
,
5577 .size
= sizeof(read_event
) + event
->read_size
,
5579 .pid
= perf_event_pid(event
, task
),
5580 .tid
= perf_event_tid(event
, task
),
5584 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5585 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5589 perf_output_put(&handle
, read_event
);
5590 perf_output_read(&handle
, event
);
5591 perf_event__output_id_sample(event
, &handle
, &sample
);
5593 perf_output_end(&handle
);
5596 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5599 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5600 perf_event_aux_output_cb output
,
5603 struct perf_event
*event
;
5605 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5606 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5608 if (!event_filter_match(event
))
5610 output(event
, data
);
5615 perf_event_aux_task_ctx(perf_event_aux_output_cb output
, void *data
,
5616 struct perf_event_context
*task_ctx
)
5620 perf_event_aux_ctx(task_ctx
, output
, data
);
5626 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5627 struct perf_event_context
*task_ctx
)
5629 struct perf_cpu_context
*cpuctx
;
5630 struct perf_event_context
*ctx
;
5635 * If we have task_ctx != NULL we only notify
5636 * the task context itself. The task_ctx is set
5637 * only for EXIT events before releasing task
5641 perf_event_aux_task_ctx(output
, data
, task_ctx
);
5646 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5647 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5648 if (cpuctx
->unique_pmu
!= pmu
)
5650 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5651 ctxn
= pmu
->task_ctx_nr
;
5654 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5656 perf_event_aux_ctx(ctx
, output
, data
);
5658 put_cpu_ptr(pmu
->pmu_cpu_context
);
5664 * task tracking -- fork/exit
5666 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5669 struct perf_task_event
{
5670 struct task_struct
*task
;
5671 struct perf_event_context
*task_ctx
;
5674 struct perf_event_header header
;
5684 static int perf_event_task_match(struct perf_event
*event
)
5686 return event
->attr
.comm
|| event
->attr
.mmap
||
5687 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5691 static void perf_event_task_output(struct perf_event
*event
,
5694 struct perf_task_event
*task_event
= data
;
5695 struct perf_output_handle handle
;
5696 struct perf_sample_data sample
;
5697 struct task_struct
*task
= task_event
->task
;
5698 int ret
, size
= task_event
->event_id
.header
.size
;
5700 if (!perf_event_task_match(event
))
5703 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5705 ret
= perf_output_begin(&handle
, event
,
5706 task_event
->event_id
.header
.size
);
5710 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5711 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5713 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5714 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5716 task_event
->event_id
.time
= perf_event_clock(event
);
5718 perf_output_put(&handle
, task_event
->event_id
);
5720 perf_event__output_id_sample(event
, &handle
, &sample
);
5722 perf_output_end(&handle
);
5724 task_event
->event_id
.header
.size
= size
;
5727 static void perf_event_task(struct task_struct
*task
,
5728 struct perf_event_context
*task_ctx
,
5731 struct perf_task_event task_event
;
5733 if (!atomic_read(&nr_comm_events
) &&
5734 !atomic_read(&nr_mmap_events
) &&
5735 !atomic_read(&nr_task_events
))
5738 task_event
= (struct perf_task_event
){
5740 .task_ctx
= task_ctx
,
5743 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5745 .size
= sizeof(task_event
.event_id
),
5755 perf_event_aux(perf_event_task_output
,
5760 void perf_event_fork(struct task_struct
*task
)
5762 perf_event_task(task
, NULL
, 1);
5769 struct perf_comm_event
{
5770 struct task_struct
*task
;
5775 struct perf_event_header header
;
5782 static int perf_event_comm_match(struct perf_event
*event
)
5784 return event
->attr
.comm
;
5787 static void perf_event_comm_output(struct perf_event
*event
,
5790 struct perf_comm_event
*comm_event
= data
;
5791 struct perf_output_handle handle
;
5792 struct perf_sample_data sample
;
5793 int size
= comm_event
->event_id
.header
.size
;
5796 if (!perf_event_comm_match(event
))
5799 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5800 ret
= perf_output_begin(&handle
, event
,
5801 comm_event
->event_id
.header
.size
);
5806 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5807 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5809 perf_output_put(&handle
, comm_event
->event_id
);
5810 __output_copy(&handle
, comm_event
->comm
,
5811 comm_event
->comm_size
);
5813 perf_event__output_id_sample(event
, &handle
, &sample
);
5815 perf_output_end(&handle
);
5817 comm_event
->event_id
.header
.size
= size
;
5820 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5822 char comm
[TASK_COMM_LEN
];
5825 memset(comm
, 0, sizeof(comm
));
5826 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5827 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5829 comm_event
->comm
= comm
;
5830 comm_event
->comm_size
= size
;
5832 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5834 perf_event_aux(perf_event_comm_output
,
5839 void perf_event_comm(struct task_struct
*task
, bool exec
)
5841 struct perf_comm_event comm_event
;
5843 if (!atomic_read(&nr_comm_events
))
5846 comm_event
= (struct perf_comm_event
){
5852 .type
= PERF_RECORD_COMM
,
5853 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5861 perf_event_comm_event(&comm_event
);
5868 struct perf_mmap_event
{
5869 struct vm_area_struct
*vma
;
5871 const char *file_name
;
5879 struct perf_event_header header
;
5889 static int perf_event_mmap_match(struct perf_event
*event
,
5892 struct perf_mmap_event
*mmap_event
= data
;
5893 struct vm_area_struct
*vma
= mmap_event
->vma
;
5894 int executable
= vma
->vm_flags
& VM_EXEC
;
5896 return (!executable
&& event
->attr
.mmap_data
) ||
5897 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5900 static void perf_event_mmap_output(struct perf_event
*event
,
5903 struct perf_mmap_event
*mmap_event
= data
;
5904 struct perf_output_handle handle
;
5905 struct perf_sample_data sample
;
5906 int size
= mmap_event
->event_id
.header
.size
;
5909 if (!perf_event_mmap_match(event
, data
))
5912 if (event
->attr
.mmap2
) {
5913 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5914 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5915 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5916 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5917 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5918 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5919 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5922 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5923 ret
= perf_output_begin(&handle
, event
,
5924 mmap_event
->event_id
.header
.size
);
5928 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5929 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5931 perf_output_put(&handle
, mmap_event
->event_id
);
5933 if (event
->attr
.mmap2
) {
5934 perf_output_put(&handle
, mmap_event
->maj
);
5935 perf_output_put(&handle
, mmap_event
->min
);
5936 perf_output_put(&handle
, mmap_event
->ino
);
5937 perf_output_put(&handle
, mmap_event
->ino_generation
);
5938 perf_output_put(&handle
, mmap_event
->prot
);
5939 perf_output_put(&handle
, mmap_event
->flags
);
5942 __output_copy(&handle
, mmap_event
->file_name
,
5943 mmap_event
->file_size
);
5945 perf_event__output_id_sample(event
, &handle
, &sample
);
5947 perf_output_end(&handle
);
5949 mmap_event
->event_id
.header
.size
= size
;
5952 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5954 struct vm_area_struct
*vma
= mmap_event
->vma
;
5955 struct file
*file
= vma
->vm_file
;
5956 int maj
= 0, min
= 0;
5957 u64 ino
= 0, gen
= 0;
5958 u32 prot
= 0, flags
= 0;
5965 struct inode
*inode
;
5968 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5974 * d_path() works from the end of the rb backwards, so we
5975 * need to add enough zero bytes after the string to handle
5976 * the 64bit alignment we do later.
5978 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
5983 inode
= file_inode(vma
->vm_file
);
5984 dev
= inode
->i_sb
->s_dev
;
5986 gen
= inode
->i_generation
;
5990 if (vma
->vm_flags
& VM_READ
)
5992 if (vma
->vm_flags
& VM_WRITE
)
5994 if (vma
->vm_flags
& VM_EXEC
)
5997 if (vma
->vm_flags
& VM_MAYSHARE
)
6000 flags
= MAP_PRIVATE
;
6002 if (vma
->vm_flags
& VM_DENYWRITE
)
6003 flags
|= MAP_DENYWRITE
;
6004 if (vma
->vm_flags
& VM_MAYEXEC
)
6005 flags
|= MAP_EXECUTABLE
;
6006 if (vma
->vm_flags
& VM_LOCKED
)
6007 flags
|= MAP_LOCKED
;
6008 if (vma
->vm_flags
& VM_HUGETLB
)
6009 flags
|= MAP_HUGETLB
;
6013 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6014 name
= (char *) vma
->vm_ops
->name(vma
);
6019 name
= (char *)arch_vma_name(vma
);
6023 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6024 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6028 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6029 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6039 strlcpy(tmp
, name
, sizeof(tmp
));
6043 * Since our buffer works in 8 byte units we need to align our string
6044 * size to a multiple of 8. However, we must guarantee the tail end is
6045 * zero'd out to avoid leaking random bits to userspace.
6047 size
= strlen(name
)+1;
6048 while (!IS_ALIGNED(size
, sizeof(u64
)))
6049 name
[size
++] = '\0';
6051 mmap_event
->file_name
= name
;
6052 mmap_event
->file_size
= size
;
6053 mmap_event
->maj
= maj
;
6054 mmap_event
->min
= min
;
6055 mmap_event
->ino
= ino
;
6056 mmap_event
->ino_generation
= gen
;
6057 mmap_event
->prot
= prot
;
6058 mmap_event
->flags
= flags
;
6060 if (!(vma
->vm_flags
& VM_EXEC
))
6061 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6063 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6065 perf_event_aux(perf_event_mmap_output
,
6072 void perf_event_mmap(struct vm_area_struct
*vma
)
6074 struct perf_mmap_event mmap_event
;
6076 if (!atomic_read(&nr_mmap_events
))
6079 mmap_event
= (struct perf_mmap_event
){
6085 .type
= PERF_RECORD_MMAP
,
6086 .misc
= PERF_RECORD_MISC_USER
,
6091 .start
= vma
->vm_start
,
6092 .len
= vma
->vm_end
- vma
->vm_start
,
6093 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6095 /* .maj (attr_mmap2 only) */
6096 /* .min (attr_mmap2 only) */
6097 /* .ino (attr_mmap2 only) */
6098 /* .ino_generation (attr_mmap2 only) */
6099 /* .prot (attr_mmap2 only) */
6100 /* .flags (attr_mmap2 only) */
6103 perf_event_mmap_event(&mmap_event
);
6106 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6107 unsigned long size
, u64 flags
)
6109 struct perf_output_handle handle
;
6110 struct perf_sample_data sample
;
6111 struct perf_aux_event
{
6112 struct perf_event_header header
;
6118 .type
= PERF_RECORD_AUX
,
6120 .size
= sizeof(rec
),
6128 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6129 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6134 perf_output_put(&handle
, rec
);
6135 perf_event__output_id_sample(event
, &handle
, &sample
);
6137 perf_output_end(&handle
);
6141 * Lost/dropped samples logging
6143 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6145 struct perf_output_handle handle
;
6146 struct perf_sample_data sample
;
6150 struct perf_event_header header
;
6152 } lost_samples_event
= {
6154 .type
= PERF_RECORD_LOST_SAMPLES
,
6156 .size
= sizeof(lost_samples_event
),
6161 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6163 ret
= perf_output_begin(&handle
, event
,
6164 lost_samples_event
.header
.size
);
6168 perf_output_put(&handle
, lost_samples_event
);
6169 perf_event__output_id_sample(event
, &handle
, &sample
);
6170 perf_output_end(&handle
);
6174 * context_switch tracking
6177 struct perf_switch_event
{
6178 struct task_struct
*task
;
6179 struct task_struct
*next_prev
;
6182 struct perf_event_header header
;
6188 static int perf_event_switch_match(struct perf_event
*event
)
6190 return event
->attr
.context_switch
;
6193 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6195 struct perf_switch_event
*se
= data
;
6196 struct perf_output_handle handle
;
6197 struct perf_sample_data sample
;
6200 if (!perf_event_switch_match(event
))
6203 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6204 if (event
->ctx
->task
) {
6205 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6206 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6208 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6209 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6210 se
->event_id
.next_prev_pid
=
6211 perf_event_pid(event
, se
->next_prev
);
6212 se
->event_id
.next_prev_tid
=
6213 perf_event_tid(event
, se
->next_prev
);
6216 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6218 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6222 if (event
->ctx
->task
)
6223 perf_output_put(&handle
, se
->event_id
.header
);
6225 perf_output_put(&handle
, se
->event_id
);
6227 perf_event__output_id_sample(event
, &handle
, &sample
);
6229 perf_output_end(&handle
);
6232 static void perf_event_switch(struct task_struct
*task
,
6233 struct task_struct
*next_prev
, bool sched_in
)
6235 struct perf_switch_event switch_event
;
6237 /* N.B. caller checks nr_switch_events != 0 */
6239 switch_event
= (struct perf_switch_event
){
6241 .next_prev
= next_prev
,
6245 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6248 /* .next_prev_pid */
6249 /* .next_prev_tid */
6253 perf_event_aux(perf_event_switch_output
,
6259 * IRQ throttle logging
6262 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6264 struct perf_output_handle handle
;
6265 struct perf_sample_data sample
;
6269 struct perf_event_header header
;
6273 } throttle_event
= {
6275 .type
= PERF_RECORD_THROTTLE
,
6277 .size
= sizeof(throttle_event
),
6279 .time
= perf_event_clock(event
),
6280 .id
= primary_event_id(event
),
6281 .stream_id
= event
->id
,
6285 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6287 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6289 ret
= perf_output_begin(&handle
, event
,
6290 throttle_event
.header
.size
);
6294 perf_output_put(&handle
, throttle_event
);
6295 perf_event__output_id_sample(event
, &handle
, &sample
);
6296 perf_output_end(&handle
);
6299 static void perf_log_itrace_start(struct perf_event
*event
)
6301 struct perf_output_handle handle
;
6302 struct perf_sample_data sample
;
6303 struct perf_aux_event
{
6304 struct perf_event_header header
;
6311 event
= event
->parent
;
6313 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6314 event
->hw
.itrace_started
)
6317 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6318 rec
.header
.misc
= 0;
6319 rec
.header
.size
= sizeof(rec
);
6320 rec
.pid
= perf_event_pid(event
, current
);
6321 rec
.tid
= perf_event_tid(event
, current
);
6323 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6324 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6329 perf_output_put(&handle
, rec
);
6330 perf_event__output_id_sample(event
, &handle
, &sample
);
6332 perf_output_end(&handle
);
6336 * Generic event overflow handling, sampling.
6339 static int __perf_event_overflow(struct perf_event
*event
,
6340 int throttle
, struct perf_sample_data
*data
,
6341 struct pt_regs
*regs
)
6343 int events
= atomic_read(&event
->event_limit
);
6344 struct hw_perf_event
*hwc
= &event
->hw
;
6349 * Non-sampling counters might still use the PMI to fold short
6350 * hardware counters, ignore those.
6352 if (unlikely(!is_sampling_event(event
)))
6355 seq
= __this_cpu_read(perf_throttled_seq
);
6356 if (seq
!= hwc
->interrupts_seq
) {
6357 hwc
->interrupts_seq
= seq
;
6358 hwc
->interrupts
= 1;
6361 if (unlikely(throttle
6362 && hwc
->interrupts
>= max_samples_per_tick
)) {
6363 __this_cpu_inc(perf_throttled_count
);
6364 hwc
->interrupts
= MAX_INTERRUPTS
;
6365 perf_log_throttle(event
, 0);
6366 tick_nohz_full_kick();
6371 if (event
->attr
.freq
) {
6372 u64 now
= perf_clock();
6373 s64 delta
= now
- hwc
->freq_time_stamp
;
6375 hwc
->freq_time_stamp
= now
;
6377 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6378 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6382 * XXX event_limit might not quite work as expected on inherited
6386 event
->pending_kill
= POLL_IN
;
6387 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6389 event
->pending_kill
= POLL_HUP
;
6390 event
->pending_disable
= 1;
6391 irq_work_queue(&event
->pending
);
6394 if (event
->overflow_handler
)
6395 event
->overflow_handler(event
, data
, regs
);
6397 perf_event_output(event
, data
, regs
);
6399 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6400 event
->pending_wakeup
= 1;
6401 irq_work_queue(&event
->pending
);
6407 int perf_event_overflow(struct perf_event
*event
,
6408 struct perf_sample_data
*data
,
6409 struct pt_regs
*regs
)
6411 return __perf_event_overflow(event
, 1, data
, regs
);
6415 * Generic software event infrastructure
6418 struct swevent_htable
{
6419 struct swevent_hlist
*swevent_hlist
;
6420 struct mutex hlist_mutex
;
6423 /* Recursion avoidance in each contexts */
6424 int recursion
[PERF_NR_CONTEXTS
];
6427 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6430 * We directly increment event->count and keep a second value in
6431 * event->hw.period_left to count intervals. This period event
6432 * is kept in the range [-sample_period, 0] so that we can use the
6436 u64
perf_swevent_set_period(struct perf_event
*event
)
6438 struct hw_perf_event
*hwc
= &event
->hw
;
6439 u64 period
= hwc
->last_period
;
6443 hwc
->last_period
= hwc
->sample_period
;
6446 old
= val
= local64_read(&hwc
->period_left
);
6450 nr
= div64_u64(period
+ val
, period
);
6451 offset
= nr
* period
;
6453 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6459 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6460 struct perf_sample_data
*data
,
6461 struct pt_regs
*regs
)
6463 struct hw_perf_event
*hwc
= &event
->hw
;
6467 overflow
= perf_swevent_set_period(event
);
6469 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6472 for (; overflow
; overflow
--) {
6473 if (__perf_event_overflow(event
, throttle
,
6476 * We inhibit the overflow from happening when
6477 * hwc->interrupts == MAX_INTERRUPTS.
6485 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6486 struct perf_sample_data
*data
,
6487 struct pt_regs
*regs
)
6489 struct hw_perf_event
*hwc
= &event
->hw
;
6491 local64_add(nr
, &event
->count
);
6496 if (!is_sampling_event(event
))
6499 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6501 return perf_swevent_overflow(event
, 1, data
, regs
);
6503 data
->period
= event
->hw
.last_period
;
6505 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6506 return perf_swevent_overflow(event
, 1, data
, regs
);
6508 if (local64_add_negative(nr
, &hwc
->period_left
))
6511 perf_swevent_overflow(event
, 0, data
, regs
);
6514 static int perf_exclude_event(struct perf_event
*event
,
6515 struct pt_regs
*regs
)
6517 if (event
->hw
.state
& PERF_HES_STOPPED
)
6521 if (event
->attr
.exclude_user
&& user_mode(regs
))
6524 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6531 static int perf_swevent_match(struct perf_event
*event
,
6532 enum perf_type_id type
,
6534 struct perf_sample_data
*data
,
6535 struct pt_regs
*regs
)
6537 if (event
->attr
.type
!= type
)
6540 if (event
->attr
.config
!= event_id
)
6543 if (perf_exclude_event(event
, regs
))
6549 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6551 u64 val
= event_id
| (type
<< 32);
6553 return hash_64(val
, SWEVENT_HLIST_BITS
);
6556 static inline struct hlist_head
*
6557 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6559 u64 hash
= swevent_hash(type
, event_id
);
6561 return &hlist
->heads
[hash
];
6564 /* For the read side: events when they trigger */
6565 static inline struct hlist_head
*
6566 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6568 struct swevent_hlist
*hlist
;
6570 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6574 return __find_swevent_head(hlist
, type
, event_id
);
6577 /* For the event head insertion and removal in the hlist */
6578 static inline struct hlist_head
*
6579 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6581 struct swevent_hlist
*hlist
;
6582 u32 event_id
= event
->attr
.config
;
6583 u64 type
= event
->attr
.type
;
6586 * Event scheduling is always serialized against hlist allocation
6587 * and release. Which makes the protected version suitable here.
6588 * The context lock guarantees that.
6590 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6591 lockdep_is_held(&event
->ctx
->lock
));
6595 return __find_swevent_head(hlist
, type
, event_id
);
6598 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6600 struct perf_sample_data
*data
,
6601 struct pt_regs
*regs
)
6603 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6604 struct perf_event
*event
;
6605 struct hlist_head
*head
;
6608 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6612 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6613 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6614 perf_swevent_event(event
, nr
, data
, regs
);
6620 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6622 int perf_swevent_get_recursion_context(void)
6624 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6626 return get_recursion_context(swhash
->recursion
);
6628 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6630 inline void perf_swevent_put_recursion_context(int rctx
)
6632 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6634 put_recursion_context(swhash
->recursion
, rctx
);
6637 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6639 struct perf_sample_data data
;
6641 if (WARN_ON_ONCE(!regs
))
6644 perf_sample_data_init(&data
, addr
, 0);
6645 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6648 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6652 preempt_disable_notrace();
6653 rctx
= perf_swevent_get_recursion_context();
6654 if (unlikely(rctx
< 0))
6657 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6659 perf_swevent_put_recursion_context(rctx
);
6661 preempt_enable_notrace();
6664 static void perf_swevent_read(struct perf_event
*event
)
6668 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6670 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6671 struct hw_perf_event
*hwc
= &event
->hw
;
6672 struct hlist_head
*head
;
6674 if (is_sampling_event(event
)) {
6675 hwc
->last_period
= hwc
->sample_period
;
6676 perf_swevent_set_period(event
);
6679 hwc
->state
= !(flags
& PERF_EF_START
);
6681 head
= find_swevent_head(swhash
, event
);
6682 if (WARN_ON_ONCE(!head
))
6685 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6686 perf_event_update_userpage(event
);
6691 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6693 hlist_del_rcu(&event
->hlist_entry
);
6696 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6698 event
->hw
.state
= 0;
6701 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6703 event
->hw
.state
= PERF_HES_STOPPED
;
6706 /* Deref the hlist from the update side */
6707 static inline struct swevent_hlist
*
6708 swevent_hlist_deref(struct swevent_htable
*swhash
)
6710 return rcu_dereference_protected(swhash
->swevent_hlist
,
6711 lockdep_is_held(&swhash
->hlist_mutex
));
6714 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6716 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6721 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6722 kfree_rcu(hlist
, rcu_head
);
6725 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6727 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6729 mutex_lock(&swhash
->hlist_mutex
);
6731 if (!--swhash
->hlist_refcount
)
6732 swevent_hlist_release(swhash
);
6734 mutex_unlock(&swhash
->hlist_mutex
);
6737 static void swevent_hlist_put(struct perf_event
*event
)
6741 for_each_possible_cpu(cpu
)
6742 swevent_hlist_put_cpu(event
, cpu
);
6745 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6747 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6750 mutex_lock(&swhash
->hlist_mutex
);
6751 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6752 struct swevent_hlist
*hlist
;
6754 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6759 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6761 swhash
->hlist_refcount
++;
6763 mutex_unlock(&swhash
->hlist_mutex
);
6768 static int swevent_hlist_get(struct perf_event
*event
)
6771 int cpu
, failed_cpu
;
6774 for_each_possible_cpu(cpu
) {
6775 err
= swevent_hlist_get_cpu(event
, cpu
);
6785 for_each_possible_cpu(cpu
) {
6786 if (cpu
== failed_cpu
)
6788 swevent_hlist_put_cpu(event
, cpu
);
6795 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6797 static void sw_perf_event_destroy(struct perf_event
*event
)
6799 u64 event_id
= event
->attr
.config
;
6801 WARN_ON(event
->parent
);
6803 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6804 swevent_hlist_put(event
);
6807 static int perf_swevent_init(struct perf_event
*event
)
6809 u64 event_id
= event
->attr
.config
;
6811 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6815 * no branch sampling for software events
6817 if (has_branch_stack(event
))
6821 case PERF_COUNT_SW_CPU_CLOCK
:
6822 case PERF_COUNT_SW_TASK_CLOCK
:
6829 if (event_id
>= PERF_COUNT_SW_MAX
)
6832 if (!event
->parent
) {
6835 err
= swevent_hlist_get(event
);
6839 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6840 event
->destroy
= sw_perf_event_destroy
;
6846 static struct pmu perf_swevent
= {
6847 .task_ctx_nr
= perf_sw_context
,
6849 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6851 .event_init
= perf_swevent_init
,
6852 .add
= perf_swevent_add
,
6853 .del
= perf_swevent_del
,
6854 .start
= perf_swevent_start
,
6855 .stop
= perf_swevent_stop
,
6856 .read
= perf_swevent_read
,
6859 #ifdef CONFIG_EVENT_TRACING
6861 static int perf_tp_filter_match(struct perf_event
*event
,
6862 struct perf_sample_data
*data
)
6864 void *record
= data
->raw
->data
;
6866 /* only top level events have filters set */
6868 event
= event
->parent
;
6870 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6875 static int perf_tp_event_match(struct perf_event
*event
,
6876 struct perf_sample_data
*data
,
6877 struct pt_regs
*regs
)
6879 if (event
->hw
.state
& PERF_HES_STOPPED
)
6882 * All tracepoints are from kernel-space.
6884 if (event
->attr
.exclude_kernel
)
6887 if (!perf_tp_filter_match(event
, data
))
6893 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6894 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6895 struct task_struct
*task
)
6897 struct perf_sample_data data
;
6898 struct perf_event
*event
;
6900 struct perf_raw_record raw
= {
6905 perf_sample_data_init(&data
, addr
, 0);
6908 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6909 if (perf_tp_event_match(event
, &data
, regs
))
6910 perf_swevent_event(event
, count
, &data
, regs
);
6914 * If we got specified a target task, also iterate its context and
6915 * deliver this event there too.
6917 if (task
&& task
!= current
) {
6918 struct perf_event_context
*ctx
;
6919 struct trace_entry
*entry
= record
;
6922 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6926 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6927 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6929 if (event
->attr
.config
!= entry
->type
)
6931 if (perf_tp_event_match(event
, &data
, regs
))
6932 perf_swevent_event(event
, count
, &data
, regs
);
6938 perf_swevent_put_recursion_context(rctx
);
6940 EXPORT_SYMBOL_GPL(perf_tp_event
);
6942 static void tp_perf_event_destroy(struct perf_event
*event
)
6944 perf_trace_destroy(event
);
6947 static int perf_tp_event_init(struct perf_event
*event
)
6951 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6955 * no branch sampling for tracepoint events
6957 if (has_branch_stack(event
))
6960 err
= perf_trace_init(event
);
6964 event
->destroy
= tp_perf_event_destroy
;
6969 static struct pmu perf_tracepoint
= {
6970 .task_ctx_nr
= perf_sw_context
,
6972 .event_init
= perf_tp_event_init
,
6973 .add
= perf_trace_add
,
6974 .del
= perf_trace_del
,
6975 .start
= perf_swevent_start
,
6976 .stop
= perf_swevent_stop
,
6977 .read
= perf_swevent_read
,
6980 static inline void perf_tp_register(void)
6982 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
6985 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6990 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6993 filter_str
= strndup_user(arg
, PAGE_SIZE
);
6994 if (IS_ERR(filter_str
))
6995 return PTR_ERR(filter_str
);
6997 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
7003 static void perf_event_free_filter(struct perf_event
*event
)
7005 ftrace_profile_free_filter(event
);
7008 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7010 struct bpf_prog
*prog
;
7012 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7015 if (event
->tp_event
->prog
)
7018 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
7019 /* bpf programs can only be attached to u/kprobes */
7022 prog
= bpf_prog_get(prog_fd
);
7024 return PTR_ERR(prog
);
7026 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7027 /* valid fd, but invalid bpf program type */
7032 event
->tp_event
->prog
= prog
;
7037 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7039 struct bpf_prog
*prog
;
7041 if (!event
->tp_event
)
7044 prog
= event
->tp_event
->prog
;
7046 event
->tp_event
->prog
= NULL
;
7053 static inline void perf_tp_register(void)
7057 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7062 static void perf_event_free_filter(struct perf_event
*event
)
7066 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7071 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7074 #endif /* CONFIG_EVENT_TRACING */
7076 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7077 void perf_bp_event(struct perf_event
*bp
, void *data
)
7079 struct perf_sample_data sample
;
7080 struct pt_regs
*regs
= data
;
7082 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7084 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7085 perf_swevent_event(bp
, 1, &sample
, regs
);
7090 * hrtimer based swevent callback
7093 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7095 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7096 struct perf_sample_data data
;
7097 struct pt_regs
*regs
;
7098 struct perf_event
*event
;
7101 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7103 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7104 return HRTIMER_NORESTART
;
7106 event
->pmu
->read(event
);
7108 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7109 regs
= get_irq_regs();
7111 if (regs
&& !perf_exclude_event(event
, regs
)) {
7112 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7113 if (__perf_event_overflow(event
, 1, &data
, regs
))
7114 ret
= HRTIMER_NORESTART
;
7117 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7118 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7123 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7125 struct hw_perf_event
*hwc
= &event
->hw
;
7128 if (!is_sampling_event(event
))
7131 period
= local64_read(&hwc
->period_left
);
7136 local64_set(&hwc
->period_left
, 0);
7138 period
= max_t(u64
, 10000, hwc
->sample_period
);
7140 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7141 HRTIMER_MODE_REL_PINNED
);
7144 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7146 struct hw_perf_event
*hwc
= &event
->hw
;
7148 if (is_sampling_event(event
)) {
7149 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7150 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7152 hrtimer_cancel(&hwc
->hrtimer
);
7156 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7158 struct hw_perf_event
*hwc
= &event
->hw
;
7160 if (!is_sampling_event(event
))
7163 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7164 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7167 * Since hrtimers have a fixed rate, we can do a static freq->period
7168 * mapping and avoid the whole period adjust feedback stuff.
7170 if (event
->attr
.freq
) {
7171 long freq
= event
->attr
.sample_freq
;
7173 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7174 hwc
->sample_period
= event
->attr
.sample_period
;
7175 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7176 hwc
->last_period
= hwc
->sample_period
;
7177 event
->attr
.freq
= 0;
7182 * Software event: cpu wall time clock
7185 static void cpu_clock_event_update(struct perf_event
*event
)
7190 now
= local_clock();
7191 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7192 local64_add(now
- prev
, &event
->count
);
7195 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7197 local64_set(&event
->hw
.prev_count
, local_clock());
7198 perf_swevent_start_hrtimer(event
);
7201 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7203 perf_swevent_cancel_hrtimer(event
);
7204 cpu_clock_event_update(event
);
7207 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7209 if (flags
& PERF_EF_START
)
7210 cpu_clock_event_start(event
, flags
);
7211 perf_event_update_userpage(event
);
7216 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7218 cpu_clock_event_stop(event
, flags
);
7221 static void cpu_clock_event_read(struct perf_event
*event
)
7223 cpu_clock_event_update(event
);
7226 static int cpu_clock_event_init(struct perf_event
*event
)
7228 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7231 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7235 * no branch sampling for software events
7237 if (has_branch_stack(event
))
7240 perf_swevent_init_hrtimer(event
);
7245 static struct pmu perf_cpu_clock
= {
7246 .task_ctx_nr
= perf_sw_context
,
7248 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7250 .event_init
= cpu_clock_event_init
,
7251 .add
= cpu_clock_event_add
,
7252 .del
= cpu_clock_event_del
,
7253 .start
= cpu_clock_event_start
,
7254 .stop
= cpu_clock_event_stop
,
7255 .read
= cpu_clock_event_read
,
7259 * Software event: task time clock
7262 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7267 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7269 local64_add(delta
, &event
->count
);
7272 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7274 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7275 perf_swevent_start_hrtimer(event
);
7278 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7280 perf_swevent_cancel_hrtimer(event
);
7281 task_clock_event_update(event
, event
->ctx
->time
);
7284 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7286 if (flags
& PERF_EF_START
)
7287 task_clock_event_start(event
, flags
);
7288 perf_event_update_userpage(event
);
7293 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7295 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7298 static void task_clock_event_read(struct perf_event
*event
)
7300 u64 now
= perf_clock();
7301 u64 delta
= now
- event
->ctx
->timestamp
;
7302 u64 time
= event
->ctx
->time
+ delta
;
7304 task_clock_event_update(event
, time
);
7307 static int task_clock_event_init(struct perf_event
*event
)
7309 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7312 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7316 * no branch sampling for software events
7318 if (has_branch_stack(event
))
7321 perf_swevent_init_hrtimer(event
);
7326 static struct pmu perf_task_clock
= {
7327 .task_ctx_nr
= perf_sw_context
,
7329 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7331 .event_init
= task_clock_event_init
,
7332 .add
= task_clock_event_add
,
7333 .del
= task_clock_event_del
,
7334 .start
= task_clock_event_start
,
7335 .stop
= task_clock_event_stop
,
7336 .read
= task_clock_event_read
,
7339 static void perf_pmu_nop_void(struct pmu
*pmu
)
7343 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7347 static int perf_pmu_nop_int(struct pmu
*pmu
)
7352 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7354 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7356 __this_cpu_write(nop_txn_flags
, flags
);
7358 if (flags
& ~PERF_PMU_TXN_ADD
)
7361 perf_pmu_disable(pmu
);
7364 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7366 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7368 __this_cpu_write(nop_txn_flags
, 0);
7370 if (flags
& ~PERF_PMU_TXN_ADD
)
7373 perf_pmu_enable(pmu
);
7377 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7379 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7381 __this_cpu_write(nop_txn_flags
, 0);
7383 if (flags
& ~PERF_PMU_TXN_ADD
)
7386 perf_pmu_enable(pmu
);
7389 static int perf_event_idx_default(struct perf_event
*event
)
7395 * Ensures all contexts with the same task_ctx_nr have the same
7396 * pmu_cpu_context too.
7398 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7405 list_for_each_entry(pmu
, &pmus
, entry
) {
7406 if (pmu
->task_ctx_nr
== ctxn
)
7407 return pmu
->pmu_cpu_context
;
7413 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7417 for_each_possible_cpu(cpu
) {
7418 struct perf_cpu_context
*cpuctx
;
7420 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7422 if (cpuctx
->unique_pmu
== old_pmu
)
7423 cpuctx
->unique_pmu
= pmu
;
7427 static void free_pmu_context(struct pmu
*pmu
)
7431 mutex_lock(&pmus_lock
);
7433 * Like a real lame refcount.
7435 list_for_each_entry(i
, &pmus
, entry
) {
7436 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7437 update_pmu_context(i
, pmu
);
7442 free_percpu(pmu
->pmu_cpu_context
);
7444 mutex_unlock(&pmus_lock
);
7446 static struct idr pmu_idr
;
7449 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7451 struct pmu
*pmu
= dev_get_drvdata(dev
);
7453 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7455 static DEVICE_ATTR_RO(type
);
7458 perf_event_mux_interval_ms_show(struct device
*dev
,
7459 struct device_attribute
*attr
,
7462 struct pmu
*pmu
= dev_get_drvdata(dev
);
7464 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7467 static DEFINE_MUTEX(mux_interval_mutex
);
7470 perf_event_mux_interval_ms_store(struct device
*dev
,
7471 struct device_attribute
*attr
,
7472 const char *buf
, size_t count
)
7474 struct pmu
*pmu
= dev_get_drvdata(dev
);
7475 int timer
, cpu
, ret
;
7477 ret
= kstrtoint(buf
, 0, &timer
);
7484 /* same value, noting to do */
7485 if (timer
== pmu
->hrtimer_interval_ms
)
7488 mutex_lock(&mux_interval_mutex
);
7489 pmu
->hrtimer_interval_ms
= timer
;
7491 /* update all cpuctx for this PMU */
7493 for_each_online_cpu(cpu
) {
7494 struct perf_cpu_context
*cpuctx
;
7495 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7496 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7498 cpu_function_call(cpu
,
7499 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7502 mutex_unlock(&mux_interval_mutex
);
7506 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7508 static struct attribute
*pmu_dev_attrs
[] = {
7509 &dev_attr_type
.attr
,
7510 &dev_attr_perf_event_mux_interval_ms
.attr
,
7513 ATTRIBUTE_GROUPS(pmu_dev
);
7515 static int pmu_bus_running
;
7516 static struct bus_type pmu_bus
= {
7517 .name
= "event_source",
7518 .dev_groups
= pmu_dev_groups
,
7521 static void pmu_dev_release(struct device
*dev
)
7526 static int pmu_dev_alloc(struct pmu
*pmu
)
7530 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7534 pmu
->dev
->groups
= pmu
->attr_groups
;
7535 device_initialize(pmu
->dev
);
7536 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7540 dev_set_drvdata(pmu
->dev
, pmu
);
7541 pmu
->dev
->bus
= &pmu_bus
;
7542 pmu
->dev
->release
= pmu_dev_release
;
7543 ret
= device_add(pmu
->dev
);
7551 put_device(pmu
->dev
);
7555 static struct lock_class_key cpuctx_mutex
;
7556 static struct lock_class_key cpuctx_lock
;
7558 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7562 mutex_lock(&pmus_lock
);
7564 pmu
->pmu_disable_count
= alloc_percpu(int);
7565 if (!pmu
->pmu_disable_count
)
7574 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7582 if (pmu_bus_running
) {
7583 ret
= pmu_dev_alloc(pmu
);
7589 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7590 if (pmu
->pmu_cpu_context
)
7591 goto got_cpu_context
;
7594 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7595 if (!pmu
->pmu_cpu_context
)
7598 for_each_possible_cpu(cpu
) {
7599 struct perf_cpu_context
*cpuctx
;
7601 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7602 __perf_event_init_context(&cpuctx
->ctx
);
7603 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7604 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7605 cpuctx
->ctx
.pmu
= pmu
;
7607 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7609 cpuctx
->unique_pmu
= pmu
;
7613 if (!pmu
->start_txn
) {
7614 if (pmu
->pmu_enable
) {
7616 * If we have pmu_enable/pmu_disable calls, install
7617 * transaction stubs that use that to try and batch
7618 * hardware accesses.
7620 pmu
->start_txn
= perf_pmu_start_txn
;
7621 pmu
->commit_txn
= perf_pmu_commit_txn
;
7622 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7624 pmu
->start_txn
= perf_pmu_nop_txn
;
7625 pmu
->commit_txn
= perf_pmu_nop_int
;
7626 pmu
->cancel_txn
= perf_pmu_nop_void
;
7630 if (!pmu
->pmu_enable
) {
7631 pmu
->pmu_enable
= perf_pmu_nop_void
;
7632 pmu
->pmu_disable
= perf_pmu_nop_void
;
7635 if (!pmu
->event_idx
)
7636 pmu
->event_idx
= perf_event_idx_default
;
7638 list_add_rcu(&pmu
->entry
, &pmus
);
7639 atomic_set(&pmu
->exclusive_cnt
, 0);
7642 mutex_unlock(&pmus_lock
);
7647 device_del(pmu
->dev
);
7648 put_device(pmu
->dev
);
7651 if (pmu
->type
>= PERF_TYPE_MAX
)
7652 idr_remove(&pmu_idr
, pmu
->type
);
7655 free_percpu(pmu
->pmu_disable_count
);
7658 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7660 void perf_pmu_unregister(struct pmu
*pmu
)
7662 mutex_lock(&pmus_lock
);
7663 list_del_rcu(&pmu
->entry
);
7664 mutex_unlock(&pmus_lock
);
7667 * We dereference the pmu list under both SRCU and regular RCU, so
7668 * synchronize against both of those.
7670 synchronize_srcu(&pmus_srcu
);
7673 free_percpu(pmu
->pmu_disable_count
);
7674 if (pmu
->type
>= PERF_TYPE_MAX
)
7675 idr_remove(&pmu_idr
, pmu
->type
);
7676 device_del(pmu
->dev
);
7677 put_device(pmu
->dev
);
7678 free_pmu_context(pmu
);
7680 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7682 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7684 struct perf_event_context
*ctx
= NULL
;
7687 if (!try_module_get(pmu
->module
))
7690 if (event
->group_leader
!= event
) {
7692 * This ctx->mutex can nest when we're called through
7693 * inheritance. See the perf_event_ctx_lock_nested() comment.
7695 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7696 SINGLE_DEPTH_NESTING
);
7701 ret
= pmu
->event_init(event
);
7704 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7707 module_put(pmu
->module
);
7712 static struct pmu
*perf_init_event(struct perf_event
*event
)
7714 struct pmu
*pmu
= NULL
;
7718 idx
= srcu_read_lock(&pmus_srcu
);
7721 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7724 ret
= perf_try_init_event(pmu
, event
);
7730 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7731 ret
= perf_try_init_event(pmu
, event
);
7735 if (ret
!= -ENOENT
) {
7740 pmu
= ERR_PTR(-ENOENT
);
7742 srcu_read_unlock(&pmus_srcu
, idx
);
7747 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7752 if (is_cgroup_event(event
))
7753 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7756 static void account_event(struct perf_event
*event
)
7763 if (event
->attach_state
& PERF_ATTACH_TASK
)
7765 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7766 atomic_inc(&nr_mmap_events
);
7767 if (event
->attr
.comm
)
7768 atomic_inc(&nr_comm_events
);
7769 if (event
->attr
.task
)
7770 atomic_inc(&nr_task_events
);
7771 if (event
->attr
.freq
) {
7772 if (atomic_inc_return(&nr_freq_events
) == 1)
7773 tick_nohz_full_kick_all();
7775 if (event
->attr
.context_switch
) {
7776 atomic_inc(&nr_switch_events
);
7779 if (has_branch_stack(event
))
7781 if (is_cgroup_event(event
))
7785 static_key_slow_inc(&perf_sched_events
.key
);
7787 account_event_cpu(event
, event
->cpu
);
7791 * Allocate and initialize a event structure
7793 static struct perf_event
*
7794 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7795 struct task_struct
*task
,
7796 struct perf_event
*group_leader
,
7797 struct perf_event
*parent_event
,
7798 perf_overflow_handler_t overflow_handler
,
7799 void *context
, int cgroup_fd
)
7802 struct perf_event
*event
;
7803 struct hw_perf_event
*hwc
;
7806 if ((unsigned)cpu
>= nr_cpu_ids
) {
7807 if (!task
|| cpu
!= -1)
7808 return ERR_PTR(-EINVAL
);
7811 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7813 return ERR_PTR(-ENOMEM
);
7816 * Single events are their own group leaders, with an
7817 * empty sibling list:
7820 group_leader
= event
;
7822 mutex_init(&event
->child_mutex
);
7823 INIT_LIST_HEAD(&event
->child_list
);
7825 INIT_LIST_HEAD(&event
->group_entry
);
7826 INIT_LIST_HEAD(&event
->event_entry
);
7827 INIT_LIST_HEAD(&event
->sibling_list
);
7828 INIT_LIST_HEAD(&event
->rb_entry
);
7829 INIT_LIST_HEAD(&event
->active_entry
);
7830 INIT_HLIST_NODE(&event
->hlist_entry
);
7833 init_waitqueue_head(&event
->waitq
);
7834 init_irq_work(&event
->pending
, perf_pending_event
);
7836 mutex_init(&event
->mmap_mutex
);
7838 atomic_long_set(&event
->refcount
, 1);
7840 event
->attr
= *attr
;
7841 event
->group_leader
= group_leader
;
7845 event
->parent
= parent_event
;
7847 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7848 event
->id
= atomic64_inc_return(&perf_event_id
);
7850 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7853 event
->attach_state
= PERF_ATTACH_TASK
;
7855 * XXX pmu::event_init needs to know what task to account to
7856 * and we cannot use the ctx information because we need the
7857 * pmu before we get a ctx.
7859 event
->hw
.target
= task
;
7862 event
->clock
= &local_clock
;
7864 event
->clock
= parent_event
->clock
;
7866 if (!overflow_handler
&& parent_event
) {
7867 overflow_handler
= parent_event
->overflow_handler
;
7868 context
= parent_event
->overflow_handler_context
;
7871 event
->overflow_handler
= overflow_handler
;
7872 event
->overflow_handler_context
= context
;
7874 perf_event__state_init(event
);
7879 hwc
->sample_period
= attr
->sample_period
;
7880 if (attr
->freq
&& attr
->sample_freq
)
7881 hwc
->sample_period
= 1;
7882 hwc
->last_period
= hwc
->sample_period
;
7884 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7887 * we currently do not support PERF_FORMAT_GROUP on inherited events
7889 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7892 if (!has_branch_stack(event
))
7893 event
->attr
.branch_sample_type
= 0;
7895 if (cgroup_fd
!= -1) {
7896 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7901 pmu
= perf_init_event(event
);
7904 else if (IS_ERR(pmu
)) {
7909 err
= exclusive_event_init(event
);
7913 if (!event
->parent
) {
7914 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7915 err
= get_callchain_buffers();
7924 exclusive_event_destroy(event
);
7928 event
->destroy(event
);
7929 module_put(pmu
->module
);
7931 if (is_cgroup_event(event
))
7932 perf_detach_cgroup(event
);
7934 put_pid_ns(event
->ns
);
7937 return ERR_PTR(err
);
7940 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
7941 struct perf_event_attr
*attr
)
7946 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
7950 * zero the full structure, so that a short copy will be nice.
7952 memset(attr
, 0, sizeof(*attr
));
7954 ret
= get_user(size
, &uattr
->size
);
7958 if (size
> PAGE_SIZE
) /* silly large */
7961 if (!size
) /* abi compat */
7962 size
= PERF_ATTR_SIZE_VER0
;
7964 if (size
< PERF_ATTR_SIZE_VER0
)
7968 * If we're handed a bigger struct than we know of,
7969 * ensure all the unknown bits are 0 - i.e. new
7970 * user-space does not rely on any kernel feature
7971 * extensions we dont know about yet.
7973 if (size
> sizeof(*attr
)) {
7974 unsigned char __user
*addr
;
7975 unsigned char __user
*end
;
7978 addr
= (void __user
*)uattr
+ sizeof(*attr
);
7979 end
= (void __user
*)uattr
+ size
;
7981 for (; addr
< end
; addr
++) {
7982 ret
= get_user(val
, addr
);
7988 size
= sizeof(*attr
);
7991 ret
= copy_from_user(attr
, uattr
, size
);
7995 if (attr
->__reserved_1
)
7998 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
8001 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
8004 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
8005 u64 mask
= attr
->branch_sample_type
;
8007 /* only using defined bits */
8008 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
8011 /* at least one branch bit must be set */
8012 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
8015 /* propagate priv level, when not set for branch */
8016 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
8018 /* exclude_kernel checked on syscall entry */
8019 if (!attr
->exclude_kernel
)
8020 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8022 if (!attr
->exclude_user
)
8023 mask
|= PERF_SAMPLE_BRANCH_USER
;
8025 if (!attr
->exclude_hv
)
8026 mask
|= PERF_SAMPLE_BRANCH_HV
;
8028 * adjust user setting (for HW filter setup)
8030 attr
->branch_sample_type
= mask
;
8032 /* privileged levels capture (kernel, hv): check permissions */
8033 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8034 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8038 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8039 ret
= perf_reg_validate(attr
->sample_regs_user
);
8044 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8045 if (!arch_perf_have_user_stack_dump())
8049 * We have __u32 type for the size, but so far
8050 * we can only use __u16 as maximum due to the
8051 * __u16 sample size limit.
8053 if (attr
->sample_stack_user
>= USHRT_MAX
)
8055 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8059 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8060 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8065 put_user(sizeof(*attr
), &uattr
->size
);
8071 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8073 struct ring_buffer
*rb
= NULL
;
8079 /* don't allow circular references */
8080 if (event
== output_event
)
8084 * Don't allow cross-cpu buffers
8086 if (output_event
->cpu
!= event
->cpu
)
8090 * If its not a per-cpu rb, it must be the same task.
8092 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8096 * Mixing clocks in the same buffer is trouble you don't need.
8098 if (output_event
->clock
!= event
->clock
)
8102 * If both events generate aux data, they must be on the same PMU
8104 if (has_aux(event
) && has_aux(output_event
) &&
8105 event
->pmu
!= output_event
->pmu
)
8109 mutex_lock(&event
->mmap_mutex
);
8110 /* Can't redirect output if we've got an active mmap() */
8111 if (atomic_read(&event
->mmap_count
))
8115 /* get the rb we want to redirect to */
8116 rb
= ring_buffer_get(output_event
);
8121 ring_buffer_attach(event
, rb
);
8125 mutex_unlock(&event
->mmap_mutex
);
8131 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8137 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8140 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8142 bool nmi_safe
= false;
8145 case CLOCK_MONOTONIC
:
8146 event
->clock
= &ktime_get_mono_fast_ns
;
8150 case CLOCK_MONOTONIC_RAW
:
8151 event
->clock
= &ktime_get_raw_fast_ns
;
8155 case CLOCK_REALTIME
:
8156 event
->clock
= &ktime_get_real_ns
;
8159 case CLOCK_BOOTTIME
:
8160 event
->clock
= &ktime_get_boot_ns
;
8164 event
->clock
= &ktime_get_tai_ns
;
8171 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8178 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8180 * @attr_uptr: event_id type attributes for monitoring/sampling
8183 * @group_fd: group leader event fd
8185 SYSCALL_DEFINE5(perf_event_open
,
8186 struct perf_event_attr __user
*, attr_uptr
,
8187 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8189 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8190 struct perf_event
*event
, *sibling
;
8191 struct perf_event_attr attr
;
8192 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8193 struct file
*event_file
= NULL
;
8194 struct fd group
= {NULL
, 0};
8195 struct task_struct
*task
= NULL
;
8200 int f_flags
= O_RDWR
;
8203 /* for future expandability... */
8204 if (flags
& ~PERF_FLAG_ALL
)
8207 err
= perf_copy_attr(attr_uptr
, &attr
);
8211 if (!attr
.exclude_kernel
) {
8212 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8217 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8220 if (attr
.sample_period
& (1ULL << 63))
8225 * In cgroup mode, the pid argument is used to pass the fd
8226 * opened to the cgroup directory in cgroupfs. The cpu argument
8227 * designates the cpu on which to monitor threads from that
8230 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8233 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8234 f_flags
|= O_CLOEXEC
;
8236 event_fd
= get_unused_fd_flags(f_flags
);
8240 if (group_fd
!= -1) {
8241 err
= perf_fget_light(group_fd
, &group
);
8244 group_leader
= group
.file
->private_data
;
8245 if (flags
& PERF_FLAG_FD_OUTPUT
)
8246 output_event
= group_leader
;
8247 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8248 group_leader
= NULL
;
8251 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8252 task
= find_lively_task_by_vpid(pid
);
8254 err
= PTR_ERR(task
);
8259 if (task
&& group_leader
&&
8260 group_leader
->attr
.inherit
!= attr
.inherit
) {
8267 if (flags
& PERF_FLAG_PID_CGROUP
)
8270 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8271 NULL
, NULL
, cgroup_fd
);
8272 if (IS_ERR(event
)) {
8273 err
= PTR_ERR(event
);
8277 if (is_sampling_event(event
)) {
8278 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8284 account_event(event
);
8287 * Special case software events and allow them to be part of
8288 * any hardware group.
8292 if (attr
.use_clockid
) {
8293 err
= perf_event_set_clock(event
, attr
.clockid
);
8299 (is_software_event(event
) != is_software_event(group_leader
))) {
8300 if (is_software_event(event
)) {
8302 * If event and group_leader are not both a software
8303 * event, and event is, then group leader is not.
8305 * Allow the addition of software events to !software
8306 * groups, this is safe because software events never
8309 pmu
= group_leader
->pmu
;
8310 } else if (is_software_event(group_leader
) &&
8311 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8313 * In case the group is a pure software group, and we
8314 * try to add a hardware event, move the whole group to
8315 * the hardware context.
8322 * Get the target context (task or percpu):
8324 ctx
= find_get_context(pmu
, task
, event
);
8330 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8336 put_task_struct(task
);
8341 * Look up the group leader (we will attach this event to it):
8347 * Do not allow a recursive hierarchy (this new sibling
8348 * becoming part of another group-sibling):
8350 if (group_leader
->group_leader
!= group_leader
)
8353 /* All events in a group should have the same clock */
8354 if (group_leader
->clock
!= event
->clock
)
8358 * Do not allow to attach to a group in a different
8359 * task or CPU context:
8363 * Make sure we're both on the same task, or both
8366 if (group_leader
->ctx
->task
!= ctx
->task
)
8370 * Make sure we're both events for the same CPU;
8371 * grouping events for different CPUs is broken; since
8372 * you can never concurrently schedule them anyhow.
8374 if (group_leader
->cpu
!= event
->cpu
)
8377 if (group_leader
->ctx
!= ctx
)
8382 * Only a group leader can be exclusive or pinned
8384 if (attr
.exclusive
|| attr
.pinned
)
8389 err
= perf_event_set_output(event
, output_event
);
8394 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8396 if (IS_ERR(event_file
)) {
8397 err
= PTR_ERR(event_file
);
8402 gctx
= group_leader
->ctx
;
8403 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8405 mutex_lock(&ctx
->mutex
);
8408 if (!perf_event_validate_size(event
)) {
8414 * Must be under the same ctx::mutex as perf_install_in_context(),
8415 * because we need to serialize with concurrent event creation.
8417 if (!exclusive_event_installable(event
, ctx
)) {
8418 /* exclusive and group stuff are assumed mutually exclusive */
8419 WARN_ON_ONCE(move_group
);
8425 WARN_ON_ONCE(ctx
->parent_ctx
);
8429 * See perf_event_ctx_lock() for comments on the details
8430 * of swizzling perf_event::ctx.
8432 perf_remove_from_context(group_leader
, false);
8434 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8436 perf_remove_from_context(sibling
, false);
8441 * Wait for everybody to stop referencing the events through
8442 * the old lists, before installing it on new lists.
8447 * Install the group siblings before the group leader.
8449 * Because a group leader will try and install the entire group
8450 * (through the sibling list, which is still in-tact), we can
8451 * end up with siblings installed in the wrong context.
8453 * By installing siblings first we NO-OP because they're not
8454 * reachable through the group lists.
8456 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8458 perf_event__state_init(sibling
);
8459 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8464 * Removing from the context ends up with disabled
8465 * event. What we want here is event in the initial
8466 * startup state, ready to be add into new context.
8468 perf_event__state_init(group_leader
);
8469 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8473 * Now that all events are installed in @ctx, nothing
8474 * references @gctx anymore, so drop the last reference we have
8481 * Precalculate sample_data sizes; do while holding ctx::mutex such
8482 * that we're serialized against further additions and before
8483 * perf_install_in_context() which is the point the event is active and
8484 * can use these values.
8486 perf_event__header_size(event
);
8487 perf_event__id_header_size(event
);
8489 event
->owner
= current
;
8491 perf_install_in_context(ctx
, event
, event
->cpu
);
8492 perf_unpin_context(ctx
);
8495 mutex_unlock(&gctx
->mutex
);
8496 mutex_unlock(&ctx
->mutex
);
8500 mutex_lock(¤t
->perf_event_mutex
);
8501 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8502 mutex_unlock(¤t
->perf_event_mutex
);
8505 * Drop the reference on the group_event after placing the
8506 * new event on the sibling_list. This ensures destruction
8507 * of the group leader will find the pointer to itself in
8508 * perf_group_detach().
8511 fd_install(event_fd
, event_file
);
8516 mutex_unlock(&gctx
->mutex
);
8517 mutex_unlock(&ctx
->mutex
);
8521 perf_unpin_context(ctx
);
8529 put_task_struct(task
);
8533 put_unused_fd(event_fd
);
8538 * perf_event_create_kernel_counter
8540 * @attr: attributes of the counter to create
8541 * @cpu: cpu in which the counter is bound
8542 * @task: task to profile (NULL for percpu)
8545 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8546 struct task_struct
*task
,
8547 perf_overflow_handler_t overflow_handler
,
8550 struct perf_event_context
*ctx
;
8551 struct perf_event
*event
;
8555 * Get the target context (task or percpu):
8558 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8559 overflow_handler
, context
, -1);
8560 if (IS_ERR(event
)) {
8561 err
= PTR_ERR(event
);
8565 /* Mark owner so we could distinguish it from user events. */
8566 event
->owner
= TASK_TOMBSTONE
;
8568 account_event(event
);
8570 ctx
= find_get_context(event
->pmu
, task
, event
);
8576 WARN_ON_ONCE(ctx
->parent_ctx
);
8577 mutex_lock(&ctx
->mutex
);
8578 if (!exclusive_event_installable(event
, ctx
)) {
8579 mutex_unlock(&ctx
->mutex
);
8580 perf_unpin_context(ctx
);
8586 perf_install_in_context(ctx
, event
, cpu
);
8587 perf_unpin_context(ctx
);
8588 mutex_unlock(&ctx
->mutex
);
8595 return ERR_PTR(err
);
8597 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8599 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8601 struct perf_event_context
*src_ctx
;
8602 struct perf_event_context
*dst_ctx
;
8603 struct perf_event
*event
, *tmp
;
8606 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8607 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8610 * See perf_event_ctx_lock() for comments on the details
8611 * of swizzling perf_event::ctx.
8613 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8614 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8616 perf_remove_from_context(event
, false);
8617 unaccount_event_cpu(event
, src_cpu
);
8619 list_add(&event
->migrate_entry
, &events
);
8623 * Wait for the events to quiesce before re-instating them.
8628 * Re-instate events in 2 passes.
8630 * Skip over group leaders and only install siblings on this first
8631 * pass, siblings will not get enabled without a leader, however a
8632 * leader will enable its siblings, even if those are still on the old
8635 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8636 if (event
->group_leader
== event
)
8639 list_del(&event
->migrate_entry
);
8640 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8641 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8642 account_event_cpu(event
, dst_cpu
);
8643 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8648 * Once all the siblings are setup properly, install the group leaders
8651 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8652 list_del(&event
->migrate_entry
);
8653 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8654 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8655 account_event_cpu(event
, dst_cpu
);
8656 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8659 mutex_unlock(&dst_ctx
->mutex
);
8660 mutex_unlock(&src_ctx
->mutex
);
8662 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8664 static void sync_child_event(struct perf_event
*child_event
,
8665 struct task_struct
*child
)
8667 struct perf_event
*parent_event
= child_event
->parent
;
8670 if (child_event
->attr
.inherit_stat
)
8671 perf_event_read_event(child_event
, child
);
8673 child_val
= perf_event_count(child_event
);
8676 * Add back the child's count to the parent's count:
8678 atomic64_add(child_val
, &parent_event
->child_count
);
8679 atomic64_add(child_event
->total_time_enabled
,
8680 &parent_event
->child_total_time_enabled
);
8681 atomic64_add(child_event
->total_time_running
,
8682 &parent_event
->child_total_time_running
);
8685 * Remove this event from the parent's list
8687 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8688 mutex_lock(&parent_event
->child_mutex
);
8689 list_del_init(&child_event
->child_list
);
8690 mutex_unlock(&parent_event
->child_mutex
);
8693 * Make sure user/parent get notified, that we just
8696 perf_event_wakeup(parent_event
);
8699 * Release the parent event, if this was the last
8702 put_event(parent_event
);
8706 __perf_event_exit_task(struct perf_event
*child_event
,
8707 struct perf_event_context
*child_ctx
,
8708 struct task_struct
*child
)
8711 * Do not destroy the 'original' grouping; because of the context
8712 * switch optimization the original events could've ended up in a
8713 * random child task.
8715 * If we were to destroy the original group, all group related
8716 * operations would cease to function properly after this random
8719 * Do destroy all inherited groups, we don't care about those
8720 * and being thorough is better.
8722 raw_spin_lock_irq(&child_ctx
->lock
);
8723 WARN_ON_ONCE(child_ctx
->is_active
);
8725 if (!!child_event
->parent
)
8726 perf_group_detach(child_event
);
8727 list_del_event(child_event
, child_ctx
);
8728 raw_spin_unlock_irq(&child_ctx
->lock
);
8731 * It can happen that the parent exits first, and has events
8732 * that are still around due to the child reference. These
8733 * events need to be zapped.
8735 if (child_event
->parent
) {
8736 sync_child_event(child_event
, child
);
8737 free_event(child_event
);
8739 child_event
->state
= PERF_EVENT_STATE_EXIT
;
8740 perf_event_wakeup(child_event
);
8744 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8746 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8747 struct perf_event
*child_event
, *next
;
8749 WARN_ON_ONCE(child
!= current
);
8751 child_ctx
= perf_pin_task_context(child
, ctxn
);
8756 * In order to reduce the amount of tricky in ctx tear-down, we hold
8757 * ctx::mutex over the entire thing. This serializes against almost
8758 * everything that wants to access the ctx.
8760 * The exception is sys_perf_event_open() /
8761 * perf_event_create_kernel_count() which does find_get_context()
8762 * without ctx::mutex (it cannot because of the move_group double mutex
8763 * lock thing). See the comments in perf_install_in_context().
8765 * We can recurse on the same lock type through:
8767 * __perf_event_exit_task()
8768 * sync_child_event()
8770 * mutex_lock(&ctx->mutex)
8772 * But since its the parent context it won't be the same instance.
8774 mutex_lock(&child_ctx
->mutex
);
8777 * In a single ctx::lock section, de-schedule the events and detach the
8778 * context from the task such that we cannot ever get it scheduled back
8781 raw_spin_lock_irq(&child_ctx
->lock
);
8782 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
);
8785 * Now that the context is inactive, destroy the task <-> ctx relation
8786 * and mark the context dead.
8788 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
8789 put_ctx(child_ctx
); /* cannot be last */
8790 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
8791 put_task_struct(current
); /* cannot be last */
8793 clone_ctx
= unclone_ctx(child_ctx
);
8794 raw_spin_unlock_irq(&child_ctx
->lock
);
8800 * Report the task dead after unscheduling the events so that we
8801 * won't get any samples after PERF_RECORD_EXIT. We can however still
8802 * get a few PERF_RECORD_READ events.
8804 perf_event_task(child
, child_ctx
, 0);
8806 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8807 __perf_event_exit_task(child_event
, child_ctx
, child
);
8809 mutex_unlock(&child_ctx
->mutex
);
8815 * When a child task exits, feed back event values to parent events.
8817 void perf_event_exit_task(struct task_struct
*child
)
8819 struct perf_event
*event
, *tmp
;
8822 mutex_lock(&child
->perf_event_mutex
);
8823 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8825 list_del_init(&event
->owner_entry
);
8828 * Ensure the list deletion is visible before we clear
8829 * the owner, closes a race against perf_release() where
8830 * we need to serialize on the owner->perf_event_mutex.
8833 event
->owner
= NULL
;
8835 mutex_unlock(&child
->perf_event_mutex
);
8837 for_each_task_context_nr(ctxn
)
8838 perf_event_exit_task_context(child
, ctxn
);
8841 * The perf_event_exit_task_context calls perf_event_task
8842 * with child's task_ctx, which generates EXIT events for
8843 * child contexts and sets child->perf_event_ctxp[] to NULL.
8844 * At this point we need to send EXIT events to cpu contexts.
8846 perf_event_task(child
, NULL
, 0);
8849 static void perf_free_event(struct perf_event
*event
,
8850 struct perf_event_context
*ctx
)
8852 struct perf_event
*parent
= event
->parent
;
8854 if (WARN_ON_ONCE(!parent
))
8857 mutex_lock(&parent
->child_mutex
);
8858 list_del_init(&event
->child_list
);
8859 mutex_unlock(&parent
->child_mutex
);
8863 raw_spin_lock_irq(&ctx
->lock
);
8864 perf_group_detach(event
);
8865 list_del_event(event
, ctx
);
8866 raw_spin_unlock_irq(&ctx
->lock
);
8871 * Free an unexposed, unused context as created by inheritance by
8872 * perf_event_init_task below, used by fork() in case of fail.
8874 * Not all locks are strictly required, but take them anyway to be nice and
8875 * help out with the lockdep assertions.
8877 void perf_event_free_task(struct task_struct
*task
)
8879 struct perf_event_context
*ctx
;
8880 struct perf_event
*event
, *tmp
;
8883 for_each_task_context_nr(ctxn
) {
8884 ctx
= task
->perf_event_ctxp
[ctxn
];
8888 mutex_lock(&ctx
->mutex
);
8890 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8892 perf_free_event(event
, ctx
);
8894 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8896 perf_free_event(event
, ctx
);
8898 if (!list_empty(&ctx
->pinned_groups
) ||
8899 !list_empty(&ctx
->flexible_groups
))
8902 mutex_unlock(&ctx
->mutex
);
8908 void perf_event_delayed_put(struct task_struct
*task
)
8912 for_each_task_context_nr(ctxn
)
8913 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8916 struct file
*perf_event_get(unsigned int fd
)
8920 file
= fget_raw(fd
);
8922 return ERR_PTR(-EBADF
);
8924 if (file
->f_op
!= &perf_fops
) {
8926 return ERR_PTR(-EBADF
);
8932 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
8935 return ERR_PTR(-EINVAL
);
8937 return &event
->attr
;
8941 * inherit a event from parent task to child task:
8943 static struct perf_event
*
8944 inherit_event(struct perf_event
*parent_event
,
8945 struct task_struct
*parent
,
8946 struct perf_event_context
*parent_ctx
,
8947 struct task_struct
*child
,
8948 struct perf_event
*group_leader
,
8949 struct perf_event_context
*child_ctx
)
8951 enum perf_event_active_state parent_state
= parent_event
->state
;
8952 struct perf_event
*child_event
;
8953 unsigned long flags
;
8956 * Instead of creating recursive hierarchies of events,
8957 * we link inherited events back to the original parent,
8958 * which has a filp for sure, which we use as the reference
8961 if (parent_event
->parent
)
8962 parent_event
= parent_event
->parent
;
8964 child_event
= perf_event_alloc(&parent_event
->attr
,
8967 group_leader
, parent_event
,
8969 if (IS_ERR(child_event
))
8972 if (is_orphaned_event(parent_event
) ||
8973 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
8974 free_event(child_event
);
8981 * Make the child state follow the state of the parent event,
8982 * not its attr.disabled bit. We hold the parent's mutex,
8983 * so we won't race with perf_event_{en, dis}able_family.
8985 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
8986 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
8988 child_event
->state
= PERF_EVENT_STATE_OFF
;
8990 if (parent_event
->attr
.freq
) {
8991 u64 sample_period
= parent_event
->hw
.sample_period
;
8992 struct hw_perf_event
*hwc
= &child_event
->hw
;
8994 hwc
->sample_period
= sample_period
;
8995 hwc
->last_period
= sample_period
;
8997 local64_set(&hwc
->period_left
, sample_period
);
9000 child_event
->ctx
= child_ctx
;
9001 child_event
->overflow_handler
= parent_event
->overflow_handler
;
9002 child_event
->overflow_handler_context
9003 = parent_event
->overflow_handler_context
;
9006 * Precalculate sample_data sizes
9008 perf_event__header_size(child_event
);
9009 perf_event__id_header_size(child_event
);
9012 * Link it up in the child's context:
9014 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
9015 add_event_to_ctx(child_event
, child_ctx
);
9016 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
9019 * Link this into the parent event's child list
9021 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
9022 mutex_lock(&parent_event
->child_mutex
);
9023 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
9024 mutex_unlock(&parent_event
->child_mutex
);
9029 static int inherit_group(struct perf_event
*parent_event
,
9030 struct task_struct
*parent
,
9031 struct perf_event_context
*parent_ctx
,
9032 struct task_struct
*child
,
9033 struct perf_event_context
*child_ctx
)
9035 struct perf_event
*leader
;
9036 struct perf_event
*sub
;
9037 struct perf_event
*child_ctr
;
9039 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9040 child
, NULL
, child_ctx
);
9042 return PTR_ERR(leader
);
9043 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9044 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9045 child
, leader
, child_ctx
);
9046 if (IS_ERR(child_ctr
))
9047 return PTR_ERR(child_ctr
);
9053 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9054 struct perf_event_context
*parent_ctx
,
9055 struct task_struct
*child
, int ctxn
,
9059 struct perf_event_context
*child_ctx
;
9061 if (!event
->attr
.inherit
) {
9066 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9069 * This is executed from the parent task context, so
9070 * inherit events that have been marked for cloning.
9071 * First allocate and initialize a context for the
9075 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9079 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9082 ret
= inherit_group(event
, parent
, parent_ctx
,
9092 * Initialize the perf_event context in task_struct
9094 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9096 struct perf_event_context
*child_ctx
, *parent_ctx
;
9097 struct perf_event_context
*cloned_ctx
;
9098 struct perf_event
*event
;
9099 struct task_struct
*parent
= current
;
9100 int inherited_all
= 1;
9101 unsigned long flags
;
9104 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9108 * If the parent's context is a clone, pin it so it won't get
9111 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9116 * No need to check if parent_ctx != NULL here; since we saw
9117 * it non-NULL earlier, the only reason for it to become NULL
9118 * is if we exit, and since we're currently in the middle of
9119 * a fork we can't be exiting at the same time.
9123 * Lock the parent list. No need to lock the child - not PID
9124 * hashed yet and not running, so nobody can access it.
9126 mutex_lock(&parent_ctx
->mutex
);
9129 * We dont have to disable NMIs - we are only looking at
9130 * the list, not manipulating it:
9132 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9133 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9134 child
, ctxn
, &inherited_all
);
9140 * We can't hold ctx->lock when iterating the ->flexible_group list due
9141 * to allocations, but we need to prevent rotation because
9142 * rotate_ctx() will change the list from interrupt context.
9144 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9145 parent_ctx
->rotate_disable
= 1;
9146 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9148 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9149 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9150 child
, ctxn
, &inherited_all
);
9155 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9156 parent_ctx
->rotate_disable
= 0;
9158 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9160 if (child_ctx
&& inherited_all
) {
9162 * Mark the child context as a clone of the parent
9163 * context, or of whatever the parent is a clone of.
9165 * Note that if the parent is a clone, the holding of
9166 * parent_ctx->lock avoids it from being uncloned.
9168 cloned_ctx
= parent_ctx
->parent_ctx
;
9170 child_ctx
->parent_ctx
= cloned_ctx
;
9171 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9173 child_ctx
->parent_ctx
= parent_ctx
;
9174 child_ctx
->parent_gen
= parent_ctx
->generation
;
9176 get_ctx(child_ctx
->parent_ctx
);
9179 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9180 mutex_unlock(&parent_ctx
->mutex
);
9182 perf_unpin_context(parent_ctx
);
9183 put_ctx(parent_ctx
);
9189 * Initialize the perf_event context in task_struct
9191 int perf_event_init_task(struct task_struct
*child
)
9195 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9196 mutex_init(&child
->perf_event_mutex
);
9197 INIT_LIST_HEAD(&child
->perf_event_list
);
9199 for_each_task_context_nr(ctxn
) {
9200 ret
= perf_event_init_context(child
, ctxn
);
9202 perf_event_free_task(child
);
9210 static void __init
perf_event_init_all_cpus(void)
9212 struct swevent_htable
*swhash
;
9215 for_each_possible_cpu(cpu
) {
9216 swhash
= &per_cpu(swevent_htable
, cpu
);
9217 mutex_init(&swhash
->hlist_mutex
);
9218 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9222 static void perf_event_init_cpu(int cpu
)
9224 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9226 mutex_lock(&swhash
->hlist_mutex
);
9227 if (swhash
->hlist_refcount
> 0) {
9228 struct swevent_hlist
*hlist
;
9230 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9232 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9234 mutex_unlock(&swhash
->hlist_mutex
);
9237 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9238 static void __perf_event_exit_context(void *__info
)
9240 struct perf_event_context
*ctx
= __info
;
9241 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
9242 struct perf_event
*event
;
9244 raw_spin_lock(&ctx
->lock
);
9245 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
9246 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)(unsigned long)true);
9247 raw_spin_unlock(&ctx
->lock
);
9250 static void perf_event_exit_cpu_context(int cpu
)
9252 struct perf_event_context
*ctx
;
9256 idx
= srcu_read_lock(&pmus_srcu
);
9257 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9258 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9260 mutex_lock(&ctx
->mutex
);
9261 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9262 mutex_unlock(&ctx
->mutex
);
9264 srcu_read_unlock(&pmus_srcu
, idx
);
9267 static void perf_event_exit_cpu(int cpu
)
9269 perf_event_exit_cpu_context(cpu
);
9272 static inline void perf_event_exit_cpu(int cpu
) { }
9276 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9280 for_each_online_cpu(cpu
)
9281 perf_event_exit_cpu(cpu
);
9287 * Run the perf reboot notifier at the very last possible moment so that
9288 * the generic watchdog code runs as long as possible.
9290 static struct notifier_block perf_reboot_notifier
= {
9291 .notifier_call
= perf_reboot
,
9292 .priority
= INT_MIN
,
9296 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9298 unsigned int cpu
= (long)hcpu
;
9300 switch (action
& ~CPU_TASKS_FROZEN
) {
9302 case CPU_UP_PREPARE
:
9303 case CPU_DOWN_FAILED
:
9304 perf_event_init_cpu(cpu
);
9307 case CPU_UP_CANCELED
:
9308 case CPU_DOWN_PREPARE
:
9309 perf_event_exit_cpu(cpu
);
9318 void __init
perf_event_init(void)
9324 perf_event_init_all_cpus();
9325 init_srcu_struct(&pmus_srcu
);
9326 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9327 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9328 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9330 perf_cpu_notifier(perf_cpu_notify
);
9331 register_reboot_notifier(&perf_reboot_notifier
);
9333 ret
= init_hw_breakpoint();
9334 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9336 /* do not patch jump label more than once per second */
9337 jump_label_rate_limit(&perf_sched_events
, HZ
);
9340 * Build time assertion that we keep the data_head at the intended
9341 * location. IOW, validation we got the __reserved[] size right.
9343 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9347 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9350 struct perf_pmu_events_attr
*pmu_attr
=
9351 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9353 if (pmu_attr
->event_str
)
9354 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9359 static int __init
perf_event_sysfs_init(void)
9364 mutex_lock(&pmus_lock
);
9366 ret
= bus_register(&pmu_bus
);
9370 list_for_each_entry(pmu
, &pmus
, entry
) {
9371 if (!pmu
->name
|| pmu
->type
< 0)
9374 ret
= pmu_dev_alloc(pmu
);
9375 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9377 pmu_bus_running
= 1;
9381 mutex_unlock(&pmus_lock
);
9385 device_initcall(perf_event_sysfs_init
);
9387 #ifdef CONFIG_CGROUP_PERF
9388 static struct cgroup_subsys_state
*
9389 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9391 struct perf_cgroup
*jc
;
9393 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9395 return ERR_PTR(-ENOMEM
);
9397 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9400 return ERR_PTR(-ENOMEM
);
9406 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9408 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9410 free_percpu(jc
->info
);
9414 static int __perf_cgroup_move(void *info
)
9416 struct task_struct
*task
= info
;
9418 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9423 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
9425 struct task_struct
*task
;
9426 struct cgroup_subsys_state
*css
;
9428 cgroup_taskset_for_each(task
, css
, tset
)
9429 task_function_call(task
, __perf_cgroup_move
, task
);
9432 struct cgroup_subsys perf_event_cgrp_subsys
= {
9433 .css_alloc
= perf_cgroup_css_alloc
,
9434 .css_free
= perf_cgroup_css_free
,
9435 .attach
= perf_cgroup_attach
,
9437 #endif /* CONFIG_CGROUP_PERF */