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>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
52 #include <asm/irq_regs.h>
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())
74 * Now that we're on right CPU with IRQs disabled, we can test
75 * if we hit the right task without races.
78 tfc
->ret
= -ESRCH
; /* No such (running) process */
83 tfc
->ret
= tfc
->func(tfc
->info
);
87 * task_function_call - call a function on the cpu on which a task runs
88 * @p: the task to evaluate
89 * @func: the function to be called
90 * @info: the function call argument
92 * Calls the function @func when the task is currently running. This might
93 * be on the current CPU, which just calls the function directly
95 * returns: @func return value, or
96 * -ESRCH - when the process isn't running
97 * -EAGAIN - when the process moved away
100 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
102 struct remote_function_call data
= {
111 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
114 } while (ret
== -EAGAIN
);
120 * cpu_function_call - call a function on the cpu
121 * @func: the function to be called
122 * @info: the function call argument
124 * Calls the function @func on the remote cpu.
126 * returns: @func return value or -ENXIO when the cpu is offline
128 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
130 struct remote_function_call data
= {
134 .ret
= -ENXIO
, /* No such CPU */
137 smp_call_function_single(cpu
, remote_function
, &data
, 1);
142 static inline struct perf_cpu_context
*
143 __get_cpu_context(struct perf_event_context
*ctx
)
145 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
148 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
149 struct perf_event_context
*ctx
)
151 raw_spin_lock(&cpuctx
->ctx
.lock
);
153 raw_spin_lock(&ctx
->lock
);
156 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
157 struct perf_event_context
*ctx
)
160 raw_spin_unlock(&ctx
->lock
);
161 raw_spin_unlock(&cpuctx
->ctx
.lock
);
164 #define TASK_TOMBSTONE ((void *)-1L)
166 static bool is_kernel_event(struct perf_event
*event
)
168 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
172 * On task ctx scheduling...
174 * When !ctx->nr_events a task context will not be scheduled. This means
175 * we can disable the scheduler hooks (for performance) without leaving
176 * pending task ctx state.
178 * This however results in two special cases:
180 * - removing the last event from a task ctx; this is relatively straight
181 * forward and is done in __perf_remove_from_context.
183 * - adding the first event to a task ctx; this is tricky because we cannot
184 * rely on ctx->is_active and therefore cannot use event_function_call().
185 * See perf_install_in_context().
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
);
281 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 raw_spin_unlock_irq(&ctx
->lock
);
298 if (ctx
->is_active
) {
299 raw_spin_unlock_irq(&ctx
->lock
);
302 func(event
, NULL
, ctx
, data
);
303 raw_spin_unlock_irq(&ctx
->lock
);
306 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
307 PERF_FLAG_FD_OUTPUT |\
308 PERF_FLAG_PID_CGROUP |\
309 PERF_FLAG_FD_CLOEXEC)
312 * branch priv levels that need permission checks
314 #define PERF_SAMPLE_BRANCH_PERM_PLM \
315 (PERF_SAMPLE_BRANCH_KERNEL |\
316 PERF_SAMPLE_BRANCH_HV)
319 EVENT_FLEXIBLE
= 0x1,
322 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
326 * perf_sched_events : >0 events exist
327 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
330 static void perf_sched_delayed(struct work_struct
*work
);
331 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
332 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
333 static DEFINE_MUTEX(perf_sched_mutex
);
334 static atomic_t perf_sched_count
;
336 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
337 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
339 static atomic_t nr_mmap_events __read_mostly
;
340 static atomic_t nr_comm_events __read_mostly
;
341 static atomic_t nr_task_events __read_mostly
;
342 static atomic_t nr_freq_events __read_mostly
;
343 static atomic_t nr_switch_events __read_mostly
;
345 static LIST_HEAD(pmus
);
346 static DEFINE_MUTEX(pmus_lock
);
347 static struct srcu_struct pmus_srcu
;
350 * perf event paranoia level:
351 * -1 - not paranoid at all
352 * 0 - disallow raw tracepoint access for unpriv
353 * 1 - disallow cpu events for unpriv
354 * 2 - disallow kernel profiling for unpriv
356 int sysctl_perf_event_paranoid __read_mostly
= 2;
358 /* Minimum for 512 kiB + 1 user control page */
359 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
362 * max perf event sample rate
364 #define DEFAULT_MAX_SAMPLE_RATE 100000
365 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
366 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
368 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
370 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
371 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
373 static int perf_sample_allowed_ns __read_mostly
=
374 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
376 static void update_perf_cpu_limits(void)
378 u64 tmp
= perf_sample_period_ns
;
380 tmp
*= sysctl_perf_cpu_time_max_percent
;
381 tmp
= div_u64(tmp
, 100);
385 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
388 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
390 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
391 void __user
*buffer
, size_t *lenp
,
394 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
399 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
400 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
401 update_perf_cpu_limits();
406 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
408 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
409 void __user
*buffer
, size_t *lenp
,
412 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
417 if (sysctl_perf_cpu_time_max_percent
== 100 ||
418 sysctl_perf_cpu_time_max_percent
== 0) {
420 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
421 WRITE_ONCE(perf_sample_allowed_ns
, 0);
423 update_perf_cpu_limits();
430 * perf samples are done in some very critical code paths (NMIs).
431 * If they take too much CPU time, the system can lock up and not
432 * get any real work done. This will drop the sample rate when
433 * we detect that events are taking too long.
435 #define NR_ACCUMULATED_SAMPLES 128
436 static DEFINE_PER_CPU(u64
, running_sample_length
);
438 static u64 __report_avg
;
439 static u64 __report_allowed
;
441 static void perf_duration_warn(struct irq_work
*w
)
443 printk_ratelimited(KERN_WARNING
444 "perf: interrupt took too long (%lld > %lld), lowering "
445 "kernel.perf_event_max_sample_rate to %d\n",
446 __report_avg
, __report_allowed
,
447 sysctl_perf_event_sample_rate
);
450 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
452 void perf_sample_event_took(u64 sample_len_ns
)
454 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
462 /* Decay the counter by 1 average sample. */
463 running_len
= __this_cpu_read(running_sample_length
);
464 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
465 running_len
+= sample_len_ns
;
466 __this_cpu_write(running_sample_length
, running_len
);
469 * Note: this will be biased artifically low until we have
470 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
471 * from having to maintain a count.
473 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
474 if (avg_len
<= max_len
)
477 __report_avg
= avg_len
;
478 __report_allowed
= max_len
;
481 * Compute a throttle threshold 25% below the current duration.
483 avg_len
+= avg_len
/ 4;
484 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
490 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
491 WRITE_ONCE(max_samples_per_tick
, max
);
493 sysctl_perf_event_sample_rate
= max
* HZ
;
494 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
496 if (!irq_work_queue(&perf_duration_work
)) {
497 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
498 "kernel.perf_event_max_sample_rate to %d\n",
499 __report_avg
, __report_allowed
,
500 sysctl_perf_event_sample_rate
);
504 static atomic64_t perf_event_id
;
506 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
507 enum event_type_t event_type
);
509 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
510 enum event_type_t event_type
,
511 struct task_struct
*task
);
513 static void update_context_time(struct perf_event_context
*ctx
);
514 static u64
perf_event_time(struct perf_event
*event
);
516 void __weak
perf_event_print_debug(void) { }
518 extern __weak
const char *perf_pmu_name(void)
523 static inline u64
perf_clock(void)
525 return local_clock();
528 static inline u64
perf_event_clock(struct perf_event
*event
)
530 return event
->clock();
533 #ifdef CONFIG_CGROUP_PERF
536 perf_cgroup_match(struct perf_event
*event
)
538 struct perf_event_context
*ctx
= event
->ctx
;
539 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
541 /* @event doesn't care about cgroup */
545 /* wants specific cgroup scope but @cpuctx isn't associated with any */
550 * Cgroup scoping is recursive. An event enabled for a cgroup is
551 * also enabled for all its descendant cgroups. If @cpuctx's
552 * cgroup is a descendant of @event's (the test covers identity
553 * case), it's a match.
555 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
556 event
->cgrp
->css
.cgroup
);
559 static inline void perf_detach_cgroup(struct perf_event
*event
)
561 css_put(&event
->cgrp
->css
);
565 static inline int is_cgroup_event(struct perf_event
*event
)
567 return event
->cgrp
!= NULL
;
570 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
572 struct perf_cgroup_info
*t
;
574 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
578 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
580 struct perf_cgroup_info
*info
;
585 info
= this_cpu_ptr(cgrp
->info
);
587 info
->time
+= now
- info
->timestamp
;
588 info
->timestamp
= now
;
591 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
593 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
595 __update_cgrp_time(cgrp_out
);
598 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
600 struct perf_cgroup
*cgrp
;
603 * ensure we access cgroup data only when needed and
604 * when we know the cgroup is pinned (css_get)
606 if (!is_cgroup_event(event
))
609 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
611 * Do not update time when cgroup is not active
613 if (cgrp
== event
->cgrp
)
614 __update_cgrp_time(event
->cgrp
);
618 perf_cgroup_set_timestamp(struct task_struct
*task
,
619 struct perf_event_context
*ctx
)
621 struct perf_cgroup
*cgrp
;
622 struct perf_cgroup_info
*info
;
625 * ctx->lock held by caller
626 * ensure we do not access cgroup data
627 * unless we have the cgroup pinned (css_get)
629 if (!task
|| !ctx
->nr_cgroups
)
632 cgrp
= perf_cgroup_from_task(task
, ctx
);
633 info
= this_cpu_ptr(cgrp
->info
);
634 info
->timestamp
= ctx
->timestamp
;
637 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
638 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
641 * reschedule events based on the cgroup constraint of task.
643 * mode SWOUT : schedule out everything
644 * mode SWIN : schedule in based on cgroup for next
646 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
648 struct perf_cpu_context
*cpuctx
;
653 * disable interrupts to avoid geting nr_cgroup
654 * changes via __perf_event_disable(). Also
657 local_irq_save(flags
);
660 * we reschedule only in the presence of cgroup
661 * constrained events.
664 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
665 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
666 if (cpuctx
->unique_pmu
!= pmu
)
667 continue; /* ensure we process each cpuctx once */
670 * perf_cgroup_events says at least one
671 * context on this CPU has cgroup events.
673 * ctx->nr_cgroups reports the number of cgroup
674 * events for a context.
676 if (cpuctx
->ctx
.nr_cgroups
> 0) {
677 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
678 perf_pmu_disable(cpuctx
->ctx
.pmu
);
680 if (mode
& PERF_CGROUP_SWOUT
) {
681 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
683 * must not be done before ctxswout due
684 * to event_filter_match() in event_sched_out()
689 if (mode
& PERF_CGROUP_SWIN
) {
690 WARN_ON_ONCE(cpuctx
->cgrp
);
692 * set cgrp before ctxsw in to allow
693 * event_filter_match() to not have to pass
695 * we pass the cpuctx->ctx to perf_cgroup_from_task()
696 * because cgorup events are only per-cpu
698 cpuctx
->cgrp
= perf_cgroup_from_task(task
, &cpuctx
->ctx
);
699 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
701 perf_pmu_enable(cpuctx
->ctx
.pmu
);
702 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
706 local_irq_restore(flags
);
709 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
710 struct task_struct
*next
)
712 struct perf_cgroup
*cgrp1
;
713 struct perf_cgroup
*cgrp2
= NULL
;
717 * we come here when we know perf_cgroup_events > 0
718 * we do not need to pass the ctx here because we know
719 * we are holding the rcu lock
721 cgrp1
= perf_cgroup_from_task(task
, NULL
);
722 cgrp2
= perf_cgroup_from_task(next
, NULL
);
725 * only schedule out current cgroup events if we know
726 * that we are switching to a different cgroup. Otherwise,
727 * do no touch the cgroup events.
730 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
735 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
736 struct task_struct
*task
)
738 struct perf_cgroup
*cgrp1
;
739 struct perf_cgroup
*cgrp2
= NULL
;
743 * we come here when we know perf_cgroup_events > 0
744 * we do not need to pass the ctx here because we know
745 * we are holding the rcu lock
747 cgrp1
= perf_cgroup_from_task(task
, NULL
);
748 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
751 * only need to schedule in cgroup events if we are changing
752 * cgroup during ctxsw. Cgroup events were not scheduled
753 * out of ctxsw out if that was not the case.
756 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
761 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
762 struct perf_event_attr
*attr
,
763 struct perf_event
*group_leader
)
765 struct perf_cgroup
*cgrp
;
766 struct cgroup_subsys_state
*css
;
767 struct fd f
= fdget(fd
);
773 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
774 &perf_event_cgrp_subsys
);
780 cgrp
= container_of(css
, struct perf_cgroup
, css
);
784 * all events in a group must monitor
785 * the same cgroup because a task belongs
786 * to only one perf cgroup at a time
788 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
789 perf_detach_cgroup(event
);
798 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
800 struct perf_cgroup_info
*t
;
801 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
802 event
->shadow_ctx_time
= now
- t
->timestamp
;
806 perf_cgroup_defer_enabled(struct perf_event
*event
)
809 * when the current task's perf cgroup does not match
810 * the event's, we need to remember to call the
811 * perf_mark_enable() function the first time a task with
812 * a matching perf cgroup is scheduled in.
814 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
815 event
->cgrp_defer_enabled
= 1;
819 perf_cgroup_mark_enabled(struct perf_event
*event
,
820 struct perf_event_context
*ctx
)
822 struct perf_event
*sub
;
823 u64 tstamp
= perf_event_time(event
);
825 if (!event
->cgrp_defer_enabled
)
828 event
->cgrp_defer_enabled
= 0;
830 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
831 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
832 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
833 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
834 sub
->cgrp_defer_enabled
= 0;
838 #else /* !CONFIG_CGROUP_PERF */
841 perf_cgroup_match(struct perf_event
*event
)
846 static inline void perf_detach_cgroup(struct perf_event
*event
)
849 static inline int is_cgroup_event(struct perf_event
*event
)
854 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
859 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
863 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
867 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
868 struct task_struct
*next
)
872 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
873 struct task_struct
*task
)
877 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
878 struct perf_event_attr
*attr
,
879 struct perf_event
*group_leader
)
885 perf_cgroup_set_timestamp(struct task_struct
*task
,
886 struct perf_event_context
*ctx
)
891 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
896 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
900 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
906 perf_cgroup_defer_enabled(struct perf_event
*event
)
911 perf_cgroup_mark_enabled(struct perf_event
*event
,
912 struct perf_event_context
*ctx
)
918 * set default to be dependent on timer tick just
921 #define PERF_CPU_HRTIMER (1000 / HZ)
923 * function must be called with interrupts disbled
925 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
927 struct perf_cpu_context
*cpuctx
;
930 WARN_ON(!irqs_disabled());
932 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
933 rotations
= perf_rotate_context(cpuctx
);
935 raw_spin_lock(&cpuctx
->hrtimer_lock
);
937 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
939 cpuctx
->hrtimer_active
= 0;
940 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
942 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
945 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
947 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
948 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
951 /* no multiplexing needed for SW PMU */
952 if (pmu
->task_ctx_nr
== perf_sw_context
)
956 * check default is sane, if not set then force to
957 * default interval (1/tick)
959 interval
= pmu
->hrtimer_interval_ms
;
961 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
963 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
965 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
966 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
967 timer
->function
= perf_mux_hrtimer_handler
;
970 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
972 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
973 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
977 if (pmu
->task_ctx_nr
== perf_sw_context
)
980 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
981 if (!cpuctx
->hrtimer_active
) {
982 cpuctx
->hrtimer_active
= 1;
983 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
984 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
986 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
991 void perf_pmu_disable(struct pmu
*pmu
)
993 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
995 pmu
->pmu_disable(pmu
);
998 void perf_pmu_enable(struct pmu
*pmu
)
1000 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1002 pmu
->pmu_enable(pmu
);
1005 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1008 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1009 * perf_event_task_tick() are fully serialized because they're strictly cpu
1010 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1011 * disabled, while perf_event_task_tick is called from IRQ context.
1013 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1015 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1017 WARN_ON(!irqs_disabled());
1019 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1021 list_add(&ctx
->active_ctx_list
, head
);
1024 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1026 WARN_ON(!irqs_disabled());
1028 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1030 list_del_init(&ctx
->active_ctx_list
);
1033 static void get_ctx(struct perf_event_context
*ctx
)
1035 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1038 static void free_ctx(struct rcu_head
*head
)
1040 struct perf_event_context
*ctx
;
1042 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1043 kfree(ctx
->task_ctx_data
);
1047 static void put_ctx(struct perf_event_context
*ctx
)
1049 if (atomic_dec_and_test(&ctx
->refcount
)) {
1050 if (ctx
->parent_ctx
)
1051 put_ctx(ctx
->parent_ctx
);
1052 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1053 put_task_struct(ctx
->task
);
1054 call_rcu(&ctx
->rcu_head
, free_ctx
);
1059 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1060 * perf_pmu_migrate_context() we need some magic.
1062 * Those places that change perf_event::ctx will hold both
1063 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1065 * Lock ordering is by mutex address. There are two other sites where
1066 * perf_event_context::mutex nests and those are:
1068 * - perf_event_exit_task_context() [ child , 0 ]
1069 * perf_event_exit_event()
1070 * put_event() [ parent, 1 ]
1072 * - perf_event_init_context() [ parent, 0 ]
1073 * inherit_task_group()
1076 * perf_event_alloc()
1078 * perf_try_init_event() [ child , 1 ]
1080 * While it appears there is an obvious deadlock here -- the parent and child
1081 * nesting levels are inverted between the two. This is in fact safe because
1082 * life-time rules separate them. That is an exiting task cannot fork, and a
1083 * spawning task cannot (yet) exit.
1085 * But remember that that these are parent<->child context relations, and
1086 * migration does not affect children, therefore these two orderings should not
1089 * The change in perf_event::ctx does not affect children (as claimed above)
1090 * because the sys_perf_event_open() case will install a new event and break
1091 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1092 * concerned with cpuctx and that doesn't have children.
1094 * The places that change perf_event::ctx will issue:
1096 * perf_remove_from_context();
1097 * synchronize_rcu();
1098 * perf_install_in_context();
1100 * to affect the change. The remove_from_context() + synchronize_rcu() should
1101 * quiesce the event, after which we can install it in the new location. This
1102 * means that only external vectors (perf_fops, prctl) can perturb the event
1103 * while in transit. Therefore all such accessors should also acquire
1104 * perf_event_context::mutex to serialize against this.
1106 * However; because event->ctx can change while we're waiting to acquire
1107 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1112 * task_struct::perf_event_mutex
1113 * perf_event_context::mutex
1114 * perf_event::child_mutex;
1115 * perf_event_context::lock
1116 * perf_event::mmap_mutex
1119 static struct perf_event_context
*
1120 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1122 struct perf_event_context
*ctx
;
1126 ctx
= ACCESS_ONCE(event
->ctx
);
1127 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1133 mutex_lock_nested(&ctx
->mutex
, nesting
);
1134 if (event
->ctx
!= ctx
) {
1135 mutex_unlock(&ctx
->mutex
);
1143 static inline struct perf_event_context
*
1144 perf_event_ctx_lock(struct perf_event
*event
)
1146 return perf_event_ctx_lock_nested(event
, 0);
1149 static void perf_event_ctx_unlock(struct perf_event
*event
,
1150 struct perf_event_context
*ctx
)
1152 mutex_unlock(&ctx
->mutex
);
1157 * This must be done under the ctx->lock, such as to serialize against
1158 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1159 * calling scheduler related locks and ctx->lock nests inside those.
1161 static __must_check
struct perf_event_context
*
1162 unclone_ctx(struct perf_event_context
*ctx
)
1164 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1166 lockdep_assert_held(&ctx
->lock
);
1169 ctx
->parent_ctx
= NULL
;
1175 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1178 * only top level events have the pid namespace they were created in
1181 event
= event
->parent
;
1183 return task_tgid_nr_ns(p
, event
->ns
);
1186 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1189 * only top level events have the pid namespace they were created in
1192 event
= event
->parent
;
1194 return task_pid_nr_ns(p
, event
->ns
);
1198 * If we inherit events we want to return the parent event id
1201 static u64
primary_event_id(struct perf_event
*event
)
1206 id
= event
->parent
->id
;
1212 * Get the perf_event_context for a task and lock it.
1214 * This has to cope with with the fact that until it is locked,
1215 * the context could get moved to another task.
1217 static struct perf_event_context
*
1218 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1220 struct perf_event_context
*ctx
;
1224 * One of the few rules of preemptible RCU is that one cannot do
1225 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1226 * part of the read side critical section was irqs-enabled -- see
1227 * rcu_read_unlock_special().
1229 * Since ctx->lock nests under rq->lock we must ensure the entire read
1230 * side critical section has interrupts disabled.
1232 local_irq_save(*flags
);
1234 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1237 * If this context is a clone of another, it might
1238 * get swapped for another underneath us by
1239 * perf_event_task_sched_out, though the
1240 * rcu_read_lock() protects us from any context
1241 * getting freed. Lock the context and check if it
1242 * got swapped before we could get the lock, and retry
1243 * if so. If we locked the right context, then it
1244 * can't get swapped on us any more.
1246 raw_spin_lock(&ctx
->lock
);
1247 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1248 raw_spin_unlock(&ctx
->lock
);
1250 local_irq_restore(*flags
);
1254 if (ctx
->task
== TASK_TOMBSTONE
||
1255 !atomic_inc_not_zero(&ctx
->refcount
)) {
1256 raw_spin_unlock(&ctx
->lock
);
1259 WARN_ON_ONCE(ctx
->task
!= task
);
1264 local_irq_restore(*flags
);
1269 * Get the context for a task and increment its pin_count so it
1270 * can't get swapped to another task. This also increments its
1271 * reference count so that the context can't get freed.
1273 static struct perf_event_context
*
1274 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1276 struct perf_event_context
*ctx
;
1277 unsigned long flags
;
1279 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1282 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1287 static void perf_unpin_context(struct perf_event_context
*ctx
)
1289 unsigned long flags
;
1291 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1293 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1297 * Update the record of the current time in a context.
1299 static void update_context_time(struct perf_event_context
*ctx
)
1301 u64 now
= perf_clock();
1303 ctx
->time
+= now
- ctx
->timestamp
;
1304 ctx
->timestamp
= now
;
1307 static u64
perf_event_time(struct perf_event
*event
)
1309 struct perf_event_context
*ctx
= event
->ctx
;
1311 if (is_cgroup_event(event
))
1312 return perf_cgroup_event_time(event
);
1314 return ctx
? ctx
->time
: 0;
1318 * Update the total_time_enabled and total_time_running fields for a event.
1320 static void update_event_times(struct perf_event
*event
)
1322 struct perf_event_context
*ctx
= event
->ctx
;
1325 lockdep_assert_held(&ctx
->lock
);
1327 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1328 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1332 * in cgroup mode, time_enabled represents
1333 * the time the event was enabled AND active
1334 * tasks were in the monitored cgroup. This is
1335 * independent of the activity of the context as
1336 * there may be a mix of cgroup and non-cgroup events.
1338 * That is why we treat cgroup events differently
1341 if (is_cgroup_event(event
))
1342 run_end
= perf_cgroup_event_time(event
);
1343 else if (ctx
->is_active
)
1344 run_end
= ctx
->time
;
1346 run_end
= event
->tstamp_stopped
;
1348 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1350 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1351 run_end
= event
->tstamp_stopped
;
1353 run_end
= perf_event_time(event
);
1355 event
->total_time_running
= run_end
- event
->tstamp_running
;
1360 * Update total_time_enabled and total_time_running for all events in a group.
1362 static void update_group_times(struct perf_event
*leader
)
1364 struct perf_event
*event
;
1366 update_event_times(leader
);
1367 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1368 update_event_times(event
);
1371 static struct list_head
*
1372 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1374 if (event
->attr
.pinned
)
1375 return &ctx
->pinned_groups
;
1377 return &ctx
->flexible_groups
;
1381 * Add a event from the lists for its context.
1382 * Must be called with ctx->mutex and ctx->lock held.
1385 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1387 lockdep_assert_held(&ctx
->lock
);
1389 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1390 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1393 * If we're a stand alone event or group leader, we go to the context
1394 * list, group events are kept attached to the group so that
1395 * perf_group_detach can, at all times, locate all siblings.
1397 if (event
->group_leader
== event
) {
1398 struct list_head
*list
;
1400 if (is_software_event(event
))
1401 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1403 list
= ctx_group_list(event
, ctx
);
1404 list_add_tail(&event
->group_entry
, list
);
1407 if (is_cgroup_event(event
))
1410 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1412 if (event
->attr
.inherit_stat
)
1419 * Initialize event state based on the perf_event_attr::disabled.
1421 static inline void perf_event__state_init(struct perf_event
*event
)
1423 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1424 PERF_EVENT_STATE_INACTIVE
;
1427 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1429 int entry
= sizeof(u64
); /* value */
1433 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1434 size
+= sizeof(u64
);
1436 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1437 size
+= sizeof(u64
);
1439 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1440 entry
+= sizeof(u64
);
1442 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1444 size
+= sizeof(u64
);
1448 event
->read_size
= size
;
1451 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1453 struct perf_sample_data
*data
;
1456 if (sample_type
& PERF_SAMPLE_IP
)
1457 size
+= sizeof(data
->ip
);
1459 if (sample_type
& PERF_SAMPLE_ADDR
)
1460 size
+= sizeof(data
->addr
);
1462 if (sample_type
& PERF_SAMPLE_PERIOD
)
1463 size
+= sizeof(data
->period
);
1465 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1466 size
+= sizeof(data
->weight
);
1468 if (sample_type
& PERF_SAMPLE_READ
)
1469 size
+= event
->read_size
;
1471 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1472 size
+= sizeof(data
->data_src
.val
);
1474 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1475 size
+= sizeof(data
->txn
);
1477 event
->header_size
= size
;
1481 * Called at perf_event creation and when events are attached/detached from a
1484 static void perf_event__header_size(struct perf_event
*event
)
1486 __perf_event_read_size(event
,
1487 event
->group_leader
->nr_siblings
);
1488 __perf_event_header_size(event
, event
->attr
.sample_type
);
1491 static void perf_event__id_header_size(struct perf_event
*event
)
1493 struct perf_sample_data
*data
;
1494 u64 sample_type
= event
->attr
.sample_type
;
1497 if (sample_type
& PERF_SAMPLE_TID
)
1498 size
+= sizeof(data
->tid_entry
);
1500 if (sample_type
& PERF_SAMPLE_TIME
)
1501 size
+= sizeof(data
->time
);
1503 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1504 size
+= sizeof(data
->id
);
1506 if (sample_type
& PERF_SAMPLE_ID
)
1507 size
+= sizeof(data
->id
);
1509 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1510 size
+= sizeof(data
->stream_id
);
1512 if (sample_type
& PERF_SAMPLE_CPU
)
1513 size
+= sizeof(data
->cpu_entry
);
1515 event
->id_header_size
= size
;
1518 static bool perf_event_validate_size(struct perf_event
*event
)
1521 * The values computed here will be over-written when we actually
1524 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1525 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1526 perf_event__id_header_size(event
);
1529 * Sum the lot; should not exceed the 64k limit we have on records.
1530 * Conservative limit to allow for callchains and other variable fields.
1532 if (event
->read_size
+ event
->header_size
+
1533 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1539 static void perf_group_attach(struct perf_event
*event
)
1541 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1544 * We can have double attach due to group movement in perf_event_open.
1546 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1549 event
->attach_state
|= PERF_ATTACH_GROUP
;
1551 if (group_leader
== event
)
1554 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1556 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1557 !is_software_event(event
))
1558 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1560 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1561 group_leader
->nr_siblings
++;
1563 perf_event__header_size(group_leader
);
1565 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1566 perf_event__header_size(pos
);
1570 * Remove a event from the lists for its context.
1571 * Must be called with ctx->mutex and ctx->lock held.
1574 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1576 struct perf_cpu_context
*cpuctx
;
1578 WARN_ON_ONCE(event
->ctx
!= ctx
);
1579 lockdep_assert_held(&ctx
->lock
);
1582 * We can have double detach due to exit/hot-unplug + close.
1584 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1587 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1589 if (is_cgroup_event(event
)) {
1592 * Because cgroup events are always per-cpu events, this will
1593 * always be called from the right CPU.
1595 cpuctx
= __get_cpu_context(ctx
);
1597 * If there are no more cgroup events then clear cgrp to avoid
1598 * stale pointer in update_cgrp_time_from_cpuctx().
1600 if (!ctx
->nr_cgroups
)
1601 cpuctx
->cgrp
= NULL
;
1605 if (event
->attr
.inherit_stat
)
1608 list_del_rcu(&event
->event_entry
);
1610 if (event
->group_leader
== event
)
1611 list_del_init(&event
->group_entry
);
1613 update_group_times(event
);
1616 * If event was in error state, then keep it
1617 * that way, otherwise bogus counts will be
1618 * returned on read(). The only way to get out
1619 * of error state is by explicit re-enabling
1622 if (event
->state
> PERF_EVENT_STATE_OFF
)
1623 event
->state
= PERF_EVENT_STATE_OFF
;
1628 static void perf_group_detach(struct perf_event
*event
)
1630 struct perf_event
*sibling
, *tmp
;
1631 struct list_head
*list
= NULL
;
1634 * We can have double detach due to exit/hot-unplug + close.
1636 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1639 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1642 * If this is a sibling, remove it from its group.
1644 if (event
->group_leader
!= event
) {
1645 list_del_init(&event
->group_entry
);
1646 event
->group_leader
->nr_siblings
--;
1650 if (!list_empty(&event
->group_entry
))
1651 list
= &event
->group_entry
;
1654 * If this was a group event with sibling events then
1655 * upgrade the siblings to singleton events by adding them
1656 * to whatever list we are on.
1658 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1660 list_move_tail(&sibling
->group_entry
, list
);
1661 sibling
->group_leader
= sibling
;
1663 /* Inherit group flags from the previous leader */
1664 sibling
->group_flags
= event
->group_flags
;
1666 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1670 perf_event__header_size(event
->group_leader
);
1672 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1673 perf_event__header_size(tmp
);
1676 static bool is_orphaned_event(struct perf_event
*event
)
1678 return event
->state
== PERF_EVENT_STATE_DEAD
;
1681 static inline int pmu_filter_match(struct perf_event
*event
)
1683 struct pmu
*pmu
= event
->pmu
;
1684 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1688 event_filter_match(struct perf_event
*event
)
1690 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1691 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1695 event_sched_out(struct perf_event
*event
,
1696 struct perf_cpu_context
*cpuctx
,
1697 struct perf_event_context
*ctx
)
1699 u64 tstamp
= perf_event_time(event
);
1702 WARN_ON_ONCE(event
->ctx
!= ctx
);
1703 lockdep_assert_held(&ctx
->lock
);
1706 * An event which could not be activated because of
1707 * filter mismatch still needs to have its timings
1708 * maintained, otherwise bogus information is return
1709 * via read() for time_enabled, time_running:
1711 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1712 && !event_filter_match(event
)) {
1713 delta
= tstamp
- event
->tstamp_stopped
;
1714 event
->tstamp_running
+= delta
;
1715 event
->tstamp_stopped
= tstamp
;
1718 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1721 perf_pmu_disable(event
->pmu
);
1723 event
->tstamp_stopped
= tstamp
;
1724 event
->pmu
->del(event
, 0);
1726 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1727 if (event
->pending_disable
) {
1728 event
->pending_disable
= 0;
1729 event
->state
= PERF_EVENT_STATE_OFF
;
1732 if (!is_software_event(event
))
1733 cpuctx
->active_oncpu
--;
1734 if (!--ctx
->nr_active
)
1735 perf_event_ctx_deactivate(ctx
);
1736 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1738 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1739 cpuctx
->exclusive
= 0;
1741 perf_pmu_enable(event
->pmu
);
1745 group_sched_out(struct perf_event
*group_event
,
1746 struct perf_cpu_context
*cpuctx
,
1747 struct perf_event_context
*ctx
)
1749 struct perf_event
*event
;
1750 int state
= group_event
->state
;
1752 event_sched_out(group_event
, cpuctx
, ctx
);
1755 * Schedule out siblings (if any):
1757 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1758 event_sched_out(event
, cpuctx
, ctx
);
1760 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1761 cpuctx
->exclusive
= 0;
1764 #define DETACH_GROUP 0x01UL
1767 * Cross CPU call to remove a performance event
1769 * We disable the event on the hardware level first. After that we
1770 * remove it from the context list.
1773 __perf_remove_from_context(struct perf_event
*event
,
1774 struct perf_cpu_context
*cpuctx
,
1775 struct perf_event_context
*ctx
,
1778 unsigned long flags
= (unsigned long)info
;
1780 event_sched_out(event
, cpuctx
, ctx
);
1781 if (flags
& DETACH_GROUP
)
1782 perf_group_detach(event
);
1783 list_del_event(event
, ctx
);
1785 if (!ctx
->nr_events
&& ctx
->is_active
) {
1788 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1789 cpuctx
->task_ctx
= NULL
;
1795 * Remove the event from a task's (or a CPU's) list of events.
1797 * If event->ctx is a cloned context, callers must make sure that
1798 * every task struct that event->ctx->task could possibly point to
1799 * remains valid. This is OK when called from perf_release since
1800 * that only calls us on the top-level context, which can't be a clone.
1801 * When called from perf_event_exit_task, it's OK because the
1802 * context has been detached from its task.
1804 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1806 lockdep_assert_held(&event
->ctx
->mutex
);
1808 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1812 * Cross CPU call to disable a performance event
1814 static void __perf_event_disable(struct perf_event
*event
,
1815 struct perf_cpu_context
*cpuctx
,
1816 struct perf_event_context
*ctx
,
1819 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1822 update_context_time(ctx
);
1823 update_cgrp_time_from_event(event
);
1824 update_group_times(event
);
1825 if (event
== event
->group_leader
)
1826 group_sched_out(event
, cpuctx
, ctx
);
1828 event_sched_out(event
, cpuctx
, ctx
);
1829 event
->state
= PERF_EVENT_STATE_OFF
;
1835 * If event->ctx is a cloned context, callers must make sure that
1836 * every task struct that event->ctx->task could possibly point to
1837 * remains valid. This condition is satisifed when called through
1838 * perf_event_for_each_child or perf_event_for_each because they
1839 * hold the top-level event's child_mutex, so any descendant that
1840 * goes to exit will block in perf_event_exit_event().
1842 * When called from perf_pending_event it's OK because event->ctx
1843 * is the current context on this CPU and preemption is disabled,
1844 * hence we can't get into perf_event_task_sched_out for this context.
1846 static void _perf_event_disable(struct perf_event
*event
)
1848 struct perf_event_context
*ctx
= event
->ctx
;
1850 raw_spin_lock_irq(&ctx
->lock
);
1851 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1852 raw_spin_unlock_irq(&ctx
->lock
);
1855 raw_spin_unlock_irq(&ctx
->lock
);
1857 event_function_call(event
, __perf_event_disable
, NULL
);
1860 void perf_event_disable_local(struct perf_event
*event
)
1862 event_function_local(event
, __perf_event_disable
, NULL
);
1866 * Strictly speaking kernel users cannot create groups and therefore this
1867 * interface does not need the perf_event_ctx_lock() magic.
1869 void perf_event_disable(struct perf_event
*event
)
1871 struct perf_event_context
*ctx
;
1873 ctx
= perf_event_ctx_lock(event
);
1874 _perf_event_disable(event
);
1875 perf_event_ctx_unlock(event
, ctx
);
1877 EXPORT_SYMBOL_GPL(perf_event_disable
);
1879 static void perf_set_shadow_time(struct perf_event
*event
,
1880 struct perf_event_context
*ctx
,
1884 * use the correct time source for the time snapshot
1886 * We could get by without this by leveraging the
1887 * fact that to get to this function, the caller
1888 * has most likely already called update_context_time()
1889 * and update_cgrp_time_xx() and thus both timestamp
1890 * are identical (or very close). Given that tstamp is,
1891 * already adjusted for cgroup, we could say that:
1892 * tstamp - ctx->timestamp
1894 * tstamp - cgrp->timestamp.
1896 * Then, in perf_output_read(), the calculation would
1897 * work with no changes because:
1898 * - event is guaranteed scheduled in
1899 * - no scheduled out in between
1900 * - thus the timestamp would be the same
1902 * But this is a bit hairy.
1904 * So instead, we have an explicit cgroup call to remain
1905 * within the time time source all along. We believe it
1906 * is cleaner and simpler to understand.
1908 if (is_cgroup_event(event
))
1909 perf_cgroup_set_shadow_time(event
, tstamp
);
1911 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1914 #define MAX_INTERRUPTS (~0ULL)
1916 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1917 static void perf_log_itrace_start(struct perf_event
*event
);
1920 event_sched_in(struct perf_event
*event
,
1921 struct perf_cpu_context
*cpuctx
,
1922 struct perf_event_context
*ctx
)
1924 u64 tstamp
= perf_event_time(event
);
1927 lockdep_assert_held(&ctx
->lock
);
1929 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1932 WRITE_ONCE(event
->oncpu
, smp_processor_id());
1934 * Order event::oncpu write to happen before the ACTIVE state
1938 WRITE_ONCE(event
->state
, PERF_EVENT_STATE_ACTIVE
);
1941 * Unthrottle events, since we scheduled we might have missed several
1942 * ticks already, also for a heavily scheduling task there is little
1943 * guarantee it'll get a tick in a timely manner.
1945 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1946 perf_log_throttle(event
, 1);
1947 event
->hw
.interrupts
= 0;
1951 * The new state must be visible before we turn it on in the hardware:
1955 perf_pmu_disable(event
->pmu
);
1957 perf_set_shadow_time(event
, ctx
, tstamp
);
1959 perf_log_itrace_start(event
);
1961 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1962 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1968 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1970 if (!is_software_event(event
))
1971 cpuctx
->active_oncpu
++;
1972 if (!ctx
->nr_active
++)
1973 perf_event_ctx_activate(ctx
);
1974 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1977 if (event
->attr
.exclusive
)
1978 cpuctx
->exclusive
= 1;
1981 perf_pmu_enable(event
->pmu
);
1987 group_sched_in(struct perf_event
*group_event
,
1988 struct perf_cpu_context
*cpuctx
,
1989 struct perf_event_context
*ctx
)
1991 struct perf_event
*event
, *partial_group
= NULL
;
1992 struct pmu
*pmu
= ctx
->pmu
;
1993 u64 now
= ctx
->time
;
1994 bool simulate
= false;
1996 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1999 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2001 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2002 pmu
->cancel_txn(pmu
);
2003 perf_mux_hrtimer_restart(cpuctx
);
2008 * Schedule in siblings as one group (if any):
2010 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2011 if (event_sched_in(event
, cpuctx
, ctx
)) {
2012 partial_group
= event
;
2017 if (!pmu
->commit_txn(pmu
))
2022 * Groups can be scheduled in as one unit only, so undo any
2023 * partial group before returning:
2024 * The events up to the failed event are scheduled out normally,
2025 * tstamp_stopped will be updated.
2027 * The failed events and the remaining siblings need to have
2028 * their timings updated as if they had gone thru event_sched_in()
2029 * and event_sched_out(). This is required to get consistent timings
2030 * across the group. This also takes care of the case where the group
2031 * could never be scheduled by ensuring tstamp_stopped is set to mark
2032 * the time the event was actually stopped, such that time delta
2033 * calculation in update_event_times() is correct.
2035 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2036 if (event
== partial_group
)
2040 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2041 event
->tstamp_stopped
= now
;
2043 event_sched_out(event
, cpuctx
, ctx
);
2046 event_sched_out(group_event
, cpuctx
, ctx
);
2048 pmu
->cancel_txn(pmu
);
2050 perf_mux_hrtimer_restart(cpuctx
);
2056 * Work out whether we can put this event group on the CPU now.
2058 static int group_can_go_on(struct perf_event
*event
,
2059 struct perf_cpu_context
*cpuctx
,
2063 * Groups consisting entirely of software events can always go on.
2065 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2068 * If an exclusive group is already on, no other hardware
2071 if (cpuctx
->exclusive
)
2074 * If this group is exclusive and there are already
2075 * events on the CPU, it can't go on.
2077 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2080 * Otherwise, try to add it if all previous groups were able
2086 static void add_event_to_ctx(struct perf_event
*event
,
2087 struct perf_event_context
*ctx
)
2089 u64 tstamp
= perf_event_time(event
);
2091 list_add_event(event
, ctx
);
2092 perf_group_attach(event
);
2093 event
->tstamp_enabled
= tstamp
;
2094 event
->tstamp_running
= tstamp
;
2095 event
->tstamp_stopped
= tstamp
;
2098 static void ctx_sched_out(struct perf_event_context
*ctx
,
2099 struct perf_cpu_context
*cpuctx
,
2100 enum event_type_t event_type
);
2102 ctx_sched_in(struct perf_event_context
*ctx
,
2103 struct perf_cpu_context
*cpuctx
,
2104 enum event_type_t event_type
,
2105 struct task_struct
*task
);
2107 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2108 struct perf_event_context
*ctx
)
2110 if (!cpuctx
->task_ctx
)
2113 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2116 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2119 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2120 struct perf_event_context
*ctx
,
2121 struct task_struct
*task
)
2123 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2125 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2126 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2128 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2131 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2132 struct perf_event_context
*task_ctx
)
2134 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2136 task_ctx_sched_out(cpuctx
, task_ctx
);
2137 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2138 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2139 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2143 * Cross CPU call to install and enable a performance event
2145 * Very similar to remote_function() + event_function() but cannot assume that
2146 * things like ctx->is_active and cpuctx->task_ctx are set.
2148 static int __perf_install_in_context(void *info
)
2150 struct perf_event
*event
= info
;
2151 struct perf_event_context
*ctx
= event
->ctx
;
2152 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2153 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2154 bool activate
= true;
2157 raw_spin_lock(&cpuctx
->ctx
.lock
);
2159 raw_spin_lock(&ctx
->lock
);
2162 /* If we're on the wrong CPU, try again */
2163 if (task_cpu(ctx
->task
) != smp_processor_id()) {
2169 * If we're on the right CPU, see if the task we target is
2170 * current, if not we don't have to activate the ctx, a future
2171 * context switch will do that for us.
2173 if (ctx
->task
!= current
)
2176 WARN_ON_ONCE(cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2178 } else if (task_ctx
) {
2179 raw_spin_lock(&task_ctx
->lock
);
2183 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2184 add_event_to_ctx(event
, ctx
);
2185 ctx_resched(cpuctx
, task_ctx
);
2187 add_event_to_ctx(event
, ctx
);
2191 perf_ctx_unlock(cpuctx
, task_ctx
);
2197 * Attach a performance event to a context.
2199 * Very similar to event_function_call, see comment there.
2202 perf_install_in_context(struct perf_event_context
*ctx
,
2203 struct perf_event
*event
,
2206 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2208 lockdep_assert_held(&ctx
->mutex
);
2211 if (event
->cpu
!= -1)
2215 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2220 * Should not happen, we validate the ctx is still alive before calling.
2222 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2226 * Installing events is tricky because we cannot rely on ctx->is_active
2227 * to be set in case this is the nr_events 0 -> 1 transition.
2231 * Cannot use task_function_call() because we need to run on the task's
2232 * CPU regardless of whether its current or not.
2234 if (!cpu_function_call(task_cpu(task
), __perf_install_in_context
, event
))
2237 raw_spin_lock_irq(&ctx
->lock
);
2239 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2241 * Cannot happen because we already checked above (which also
2242 * cannot happen), and we hold ctx->mutex, which serializes us
2243 * against perf_event_exit_task_context().
2245 raw_spin_unlock_irq(&ctx
->lock
);
2248 raw_spin_unlock_irq(&ctx
->lock
);
2250 * Since !ctx->is_active doesn't mean anything, we must IPI
2257 * Put a event into inactive state and update time fields.
2258 * Enabling the leader of a group effectively enables all
2259 * the group members that aren't explicitly disabled, so we
2260 * have to update their ->tstamp_enabled also.
2261 * Note: this works for group members as well as group leaders
2262 * since the non-leader members' sibling_lists will be empty.
2264 static void __perf_event_mark_enabled(struct perf_event
*event
)
2266 struct perf_event
*sub
;
2267 u64 tstamp
= perf_event_time(event
);
2269 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2270 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2271 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2272 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2273 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2278 * Cross CPU call to enable a performance event
2280 static void __perf_event_enable(struct perf_event
*event
,
2281 struct perf_cpu_context
*cpuctx
,
2282 struct perf_event_context
*ctx
,
2285 struct perf_event
*leader
= event
->group_leader
;
2286 struct perf_event_context
*task_ctx
;
2288 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2289 event
->state
<= PERF_EVENT_STATE_ERROR
)
2293 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2295 __perf_event_mark_enabled(event
);
2297 if (!ctx
->is_active
)
2300 if (!event_filter_match(event
)) {
2301 if (is_cgroup_event(event
))
2302 perf_cgroup_defer_enabled(event
);
2303 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2308 * If the event is in a group and isn't the group leader,
2309 * then don't put it on unless the group is on.
2311 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2312 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2316 task_ctx
= cpuctx
->task_ctx
;
2318 WARN_ON_ONCE(task_ctx
!= ctx
);
2320 ctx_resched(cpuctx
, task_ctx
);
2326 * If event->ctx is a cloned context, callers must make sure that
2327 * every task struct that event->ctx->task could possibly point to
2328 * remains valid. This condition is satisfied when called through
2329 * perf_event_for_each_child or perf_event_for_each as described
2330 * for perf_event_disable.
2332 static void _perf_event_enable(struct perf_event
*event
)
2334 struct perf_event_context
*ctx
= event
->ctx
;
2336 raw_spin_lock_irq(&ctx
->lock
);
2337 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2338 event
->state
< PERF_EVENT_STATE_ERROR
) {
2339 raw_spin_unlock_irq(&ctx
->lock
);
2344 * If the event is in error state, clear that first.
2346 * That way, if we see the event in error state below, we know that it
2347 * has gone back into error state, as distinct from the task having
2348 * been scheduled away before the cross-call arrived.
2350 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2351 event
->state
= PERF_EVENT_STATE_OFF
;
2352 raw_spin_unlock_irq(&ctx
->lock
);
2354 event_function_call(event
, __perf_event_enable
, NULL
);
2358 * See perf_event_disable();
2360 void perf_event_enable(struct perf_event
*event
)
2362 struct perf_event_context
*ctx
;
2364 ctx
= perf_event_ctx_lock(event
);
2365 _perf_event_enable(event
);
2366 perf_event_ctx_unlock(event
, ctx
);
2368 EXPORT_SYMBOL_GPL(perf_event_enable
);
2370 struct stop_event_data
{
2371 struct perf_event
*event
;
2372 unsigned int restart
;
2375 static int __perf_event_stop(void *info
)
2377 struct stop_event_data
*sd
= info
;
2378 struct perf_event
*event
= sd
->event
;
2380 /* if it's already INACTIVE, do nothing */
2381 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2384 /* matches smp_wmb() in event_sched_in() */
2388 * There is a window with interrupts enabled before we get here,
2389 * so we need to check again lest we try to stop another CPU's event.
2391 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2394 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2397 * May race with the actual stop (through perf_pmu_output_stop()),
2398 * but it is only used for events with AUX ring buffer, and such
2399 * events will refuse to restart because of rb::aux_mmap_count==0,
2400 * see comments in perf_aux_output_begin().
2402 * Since this is happening on a event-local CPU, no trace is lost
2406 event
->pmu
->start(event
, PERF_EF_START
);
2411 static int perf_event_restart(struct perf_event
*event
)
2413 struct stop_event_data sd
= {
2420 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2423 /* matches smp_wmb() in event_sched_in() */
2427 * We only want to restart ACTIVE events, so if the event goes
2428 * inactive here (event->oncpu==-1), there's nothing more to do;
2429 * fall through with ret==-ENXIO.
2431 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2432 __perf_event_stop
, &sd
);
2433 } while (ret
== -EAGAIN
);
2439 * In order to contain the amount of racy and tricky in the address filter
2440 * configuration management, it is a two part process:
2442 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2443 * we update the addresses of corresponding vmas in
2444 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2445 * (p2) when an event is scheduled in (pmu::add), it calls
2446 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2447 * if the generation has changed since the previous call.
2449 * If (p1) happens while the event is active, we restart it to force (p2).
2451 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2452 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2454 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2455 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2457 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2460 void perf_event_addr_filters_sync(struct perf_event
*event
)
2462 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2464 if (!has_addr_filter(event
))
2467 raw_spin_lock(&ifh
->lock
);
2468 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2469 event
->pmu
->addr_filters_sync(event
);
2470 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2472 raw_spin_unlock(&ifh
->lock
);
2474 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2476 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2479 * not supported on inherited events
2481 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2484 atomic_add(refresh
, &event
->event_limit
);
2485 _perf_event_enable(event
);
2491 * See perf_event_disable()
2493 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2495 struct perf_event_context
*ctx
;
2498 ctx
= perf_event_ctx_lock(event
);
2499 ret
= _perf_event_refresh(event
, refresh
);
2500 perf_event_ctx_unlock(event
, ctx
);
2504 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2506 static void ctx_sched_out(struct perf_event_context
*ctx
,
2507 struct perf_cpu_context
*cpuctx
,
2508 enum event_type_t event_type
)
2510 int is_active
= ctx
->is_active
;
2511 struct perf_event
*event
;
2513 lockdep_assert_held(&ctx
->lock
);
2515 if (likely(!ctx
->nr_events
)) {
2517 * See __perf_remove_from_context().
2519 WARN_ON_ONCE(ctx
->is_active
);
2521 WARN_ON_ONCE(cpuctx
->task_ctx
);
2525 ctx
->is_active
&= ~event_type
;
2526 if (!(ctx
->is_active
& EVENT_ALL
))
2530 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2531 if (!ctx
->is_active
)
2532 cpuctx
->task_ctx
= NULL
;
2536 * Always update time if it was set; not only when it changes.
2537 * Otherwise we can 'forget' to update time for any but the last
2538 * context we sched out. For example:
2540 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2541 * ctx_sched_out(.event_type = EVENT_PINNED)
2543 * would only update time for the pinned events.
2545 if (is_active
& EVENT_TIME
) {
2546 /* update (and stop) ctx time */
2547 update_context_time(ctx
);
2548 update_cgrp_time_from_cpuctx(cpuctx
);
2551 is_active
^= ctx
->is_active
; /* changed bits */
2553 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2556 perf_pmu_disable(ctx
->pmu
);
2557 if (is_active
& EVENT_PINNED
) {
2558 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2559 group_sched_out(event
, cpuctx
, ctx
);
2562 if (is_active
& EVENT_FLEXIBLE
) {
2563 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2564 group_sched_out(event
, cpuctx
, ctx
);
2566 perf_pmu_enable(ctx
->pmu
);
2570 * Test whether two contexts are equivalent, i.e. whether they have both been
2571 * cloned from the same version of the same context.
2573 * Equivalence is measured using a generation number in the context that is
2574 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2575 * and list_del_event().
2577 static int context_equiv(struct perf_event_context
*ctx1
,
2578 struct perf_event_context
*ctx2
)
2580 lockdep_assert_held(&ctx1
->lock
);
2581 lockdep_assert_held(&ctx2
->lock
);
2583 /* Pinning disables the swap optimization */
2584 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2587 /* If ctx1 is the parent of ctx2 */
2588 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2591 /* If ctx2 is the parent of ctx1 */
2592 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2596 * If ctx1 and ctx2 have the same parent; we flatten the parent
2597 * hierarchy, see perf_event_init_context().
2599 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2600 ctx1
->parent_gen
== ctx2
->parent_gen
)
2607 static void __perf_event_sync_stat(struct perf_event
*event
,
2608 struct perf_event
*next_event
)
2612 if (!event
->attr
.inherit_stat
)
2616 * Update the event value, we cannot use perf_event_read()
2617 * because we're in the middle of a context switch and have IRQs
2618 * disabled, which upsets smp_call_function_single(), however
2619 * we know the event must be on the current CPU, therefore we
2620 * don't need to use it.
2622 switch (event
->state
) {
2623 case PERF_EVENT_STATE_ACTIVE
:
2624 event
->pmu
->read(event
);
2627 case PERF_EVENT_STATE_INACTIVE
:
2628 update_event_times(event
);
2636 * In order to keep per-task stats reliable we need to flip the event
2637 * values when we flip the contexts.
2639 value
= local64_read(&next_event
->count
);
2640 value
= local64_xchg(&event
->count
, value
);
2641 local64_set(&next_event
->count
, value
);
2643 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2644 swap(event
->total_time_running
, next_event
->total_time_running
);
2647 * Since we swizzled the values, update the user visible data too.
2649 perf_event_update_userpage(event
);
2650 perf_event_update_userpage(next_event
);
2653 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2654 struct perf_event_context
*next_ctx
)
2656 struct perf_event
*event
, *next_event
;
2661 update_context_time(ctx
);
2663 event
= list_first_entry(&ctx
->event_list
,
2664 struct perf_event
, event_entry
);
2666 next_event
= list_first_entry(&next_ctx
->event_list
,
2667 struct perf_event
, event_entry
);
2669 while (&event
->event_entry
!= &ctx
->event_list
&&
2670 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2672 __perf_event_sync_stat(event
, next_event
);
2674 event
= list_next_entry(event
, event_entry
);
2675 next_event
= list_next_entry(next_event
, event_entry
);
2679 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2680 struct task_struct
*next
)
2682 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2683 struct perf_event_context
*next_ctx
;
2684 struct perf_event_context
*parent
, *next_parent
;
2685 struct perf_cpu_context
*cpuctx
;
2691 cpuctx
= __get_cpu_context(ctx
);
2692 if (!cpuctx
->task_ctx
)
2696 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2700 parent
= rcu_dereference(ctx
->parent_ctx
);
2701 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2703 /* If neither context have a parent context; they cannot be clones. */
2704 if (!parent
&& !next_parent
)
2707 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2709 * Looks like the two contexts are clones, so we might be
2710 * able to optimize the context switch. We lock both
2711 * contexts and check that they are clones under the
2712 * lock (including re-checking that neither has been
2713 * uncloned in the meantime). It doesn't matter which
2714 * order we take the locks because no other cpu could
2715 * be trying to lock both of these tasks.
2717 raw_spin_lock(&ctx
->lock
);
2718 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2719 if (context_equiv(ctx
, next_ctx
)) {
2720 WRITE_ONCE(ctx
->task
, next
);
2721 WRITE_ONCE(next_ctx
->task
, task
);
2723 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2726 * RCU_INIT_POINTER here is safe because we've not
2727 * modified the ctx and the above modification of
2728 * ctx->task and ctx->task_ctx_data are immaterial
2729 * since those values are always verified under
2730 * ctx->lock which we're now holding.
2732 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2733 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2737 perf_event_sync_stat(ctx
, next_ctx
);
2739 raw_spin_unlock(&next_ctx
->lock
);
2740 raw_spin_unlock(&ctx
->lock
);
2746 raw_spin_lock(&ctx
->lock
);
2747 task_ctx_sched_out(cpuctx
, ctx
);
2748 raw_spin_unlock(&ctx
->lock
);
2752 void perf_sched_cb_dec(struct pmu
*pmu
)
2754 this_cpu_dec(perf_sched_cb_usages
);
2757 void perf_sched_cb_inc(struct pmu
*pmu
)
2759 this_cpu_inc(perf_sched_cb_usages
);
2763 * This function provides the context switch callback to the lower code
2764 * layer. It is invoked ONLY when the context switch callback is enabled.
2766 static void perf_pmu_sched_task(struct task_struct
*prev
,
2767 struct task_struct
*next
,
2770 struct perf_cpu_context
*cpuctx
;
2772 unsigned long flags
;
2777 local_irq_save(flags
);
2781 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2782 if (pmu
->sched_task
) {
2783 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2785 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2787 perf_pmu_disable(pmu
);
2789 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2791 perf_pmu_enable(pmu
);
2793 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2799 local_irq_restore(flags
);
2802 static void perf_event_switch(struct task_struct
*task
,
2803 struct task_struct
*next_prev
, bool sched_in
);
2805 #define for_each_task_context_nr(ctxn) \
2806 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2809 * Called from scheduler to remove the events of the current task,
2810 * with interrupts disabled.
2812 * We stop each event and update the event value in event->count.
2814 * This does not protect us against NMI, but disable()
2815 * sets the disabled bit in the control field of event _before_
2816 * accessing the event control register. If a NMI hits, then it will
2817 * not restart the event.
2819 void __perf_event_task_sched_out(struct task_struct
*task
,
2820 struct task_struct
*next
)
2824 if (__this_cpu_read(perf_sched_cb_usages
))
2825 perf_pmu_sched_task(task
, next
, false);
2827 if (atomic_read(&nr_switch_events
))
2828 perf_event_switch(task
, next
, false);
2830 for_each_task_context_nr(ctxn
)
2831 perf_event_context_sched_out(task
, ctxn
, next
);
2834 * if cgroup events exist on this CPU, then we need
2835 * to check if we have to switch out PMU state.
2836 * cgroup event are system-wide mode only
2838 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2839 perf_cgroup_sched_out(task
, next
);
2843 * Called with IRQs disabled
2845 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2846 enum event_type_t event_type
)
2848 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2852 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2853 struct perf_cpu_context
*cpuctx
)
2855 struct perf_event
*event
;
2857 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2858 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2860 if (!event_filter_match(event
))
2863 /* may need to reset tstamp_enabled */
2864 if (is_cgroup_event(event
))
2865 perf_cgroup_mark_enabled(event
, ctx
);
2867 if (group_can_go_on(event
, cpuctx
, 1))
2868 group_sched_in(event
, cpuctx
, ctx
);
2871 * If this pinned group hasn't been scheduled,
2872 * put it in error state.
2874 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2875 update_group_times(event
);
2876 event
->state
= PERF_EVENT_STATE_ERROR
;
2882 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2883 struct perf_cpu_context
*cpuctx
)
2885 struct perf_event
*event
;
2888 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2889 /* Ignore events in OFF or ERROR state */
2890 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2893 * Listen to the 'cpu' scheduling filter constraint
2896 if (!event_filter_match(event
))
2899 /* may need to reset tstamp_enabled */
2900 if (is_cgroup_event(event
))
2901 perf_cgroup_mark_enabled(event
, ctx
);
2903 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2904 if (group_sched_in(event
, cpuctx
, ctx
))
2911 ctx_sched_in(struct perf_event_context
*ctx
,
2912 struct perf_cpu_context
*cpuctx
,
2913 enum event_type_t event_type
,
2914 struct task_struct
*task
)
2916 int is_active
= ctx
->is_active
;
2919 lockdep_assert_held(&ctx
->lock
);
2921 if (likely(!ctx
->nr_events
))
2924 ctx
->is_active
|= (event_type
| EVENT_TIME
);
2927 cpuctx
->task_ctx
= ctx
;
2929 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2932 is_active
^= ctx
->is_active
; /* changed bits */
2934 if (is_active
& EVENT_TIME
) {
2935 /* start ctx time */
2937 ctx
->timestamp
= now
;
2938 perf_cgroup_set_timestamp(task
, ctx
);
2942 * First go through the list and put on any pinned groups
2943 * in order to give them the best chance of going on.
2945 if (is_active
& EVENT_PINNED
)
2946 ctx_pinned_sched_in(ctx
, cpuctx
);
2948 /* Then walk through the lower prio flexible groups */
2949 if (is_active
& EVENT_FLEXIBLE
)
2950 ctx_flexible_sched_in(ctx
, cpuctx
);
2953 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2954 enum event_type_t event_type
,
2955 struct task_struct
*task
)
2957 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2959 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2962 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2963 struct task_struct
*task
)
2965 struct perf_cpu_context
*cpuctx
;
2967 cpuctx
= __get_cpu_context(ctx
);
2968 if (cpuctx
->task_ctx
== ctx
)
2971 perf_ctx_lock(cpuctx
, ctx
);
2972 perf_pmu_disable(ctx
->pmu
);
2974 * We want to keep the following priority order:
2975 * cpu pinned (that don't need to move), task pinned,
2976 * cpu flexible, task flexible.
2978 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2979 perf_event_sched_in(cpuctx
, ctx
, task
);
2980 perf_pmu_enable(ctx
->pmu
);
2981 perf_ctx_unlock(cpuctx
, ctx
);
2985 * Called from scheduler to add the events of the current task
2986 * with interrupts disabled.
2988 * We restore the event value and then enable it.
2990 * This does not protect us against NMI, but enable()
2991 * sets the enabled bit in the control field of event _before_
2992 * accessing the event control register. If a NMI hits, then it will
2993 * keep the event running.
2995 void __perf_event_task_sched_in(struct task_struct
*prev
,
2996 struct task_struct
*task
)
2998 struct perf_event_context
*ctx
;
3002 * If cgroup events exist on this CPU, then we need to check if we have
3003 * to switch in PMU state; cgroup event are system-wide mode only.
3005 * Since cgroup events are CPU events, we must schedule these in before
3006 * we schedule in the task events.
3008 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3009 perf_cgroup_sched_in(prev
, task
);
3011 for_each_task_context_nr(ctxn
) {
3012 ctx
= task
->perf_event_ctxp
[ctxn
];
3016 perf_event_context_sched_in(ctx
, task
);
3019 if (atomic_read(&nr_switch_events
))
3020 perf_event_switch(task
, prev
, true);
3022 if (__this_cpu_read(perf_sched_cb_usages
))
3023 perf_pmu_sched_task(prev
, task
, true);
3026 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3028 u64 frequency
= event
->attr
.sample_freq
;
3029 u64 sec
= NSEC_PER_SEC
;
3030 u64 divisor
, dividend
;
3032 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3034 count_fls
= fls64(count
);
3035 nsec_fls
= fls64(nsec
);
3036 frequency_fls
= fls64(frequency
);
3040 * We got @count in @nsec, with a target of sample_freq HZ
3041 * the target period becomes:
3044 * period = -------------------
3045 * @nsec * sample_freq
3050 * Reduce accuracy by one bit such that @a and @b converge
3051 * to a similar magnitude.
3053 #define REDUCE_FLS(a, b) \
3055 if (a##_fls > b##_fls) { \
3065 * Reduce accuracy until either term fits in a u64, then proceed with
3066 * the other, so that finally we can do a u64/u64 division.
3068 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3069 REDUCE_FLS(nsec
, frequency
);
3070 REDUCE_FLS(sec
, count
);
3073 if (count_fls
+ sec_fls
> 64) {
3074 divisor
= nsec
* frequency
;
3076 while (count_fls
+ sec_fls
> 64) {
3077 REDUCE_FLS(count
, sec
);
3081 dividend
= count
* sec
;
3083 dividend
= count
* sec
;
3085 while (nsec_fls
+ frequency_fls
> 64) {
3086 REDUCE_FLS(nsec
, frequency
);
3090 divisor
= nsec
* frequency
;
3096 return div64_u64(dividend
, divisor
);
3099 static DEFINE_PER_CPU(int, perf_throttled_count
);
3100 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3102 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3104 struct hw_perf_event
*hwc
= &event
->hw
;
3105 s64 period
, sample_period
;
3108 period
= perf_calculate_period(event
, nsec
, count
);
3110 delta
= (s64
)(period
- hwc
->sample_period
);
3111 delta
= (delta
+ 7) / 8; /* low pass filter */
3113 sample_period
= hwc
->sample_period
+ delta
;
3118 hwc
->sample_period
= sample_period
;
3120 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3122 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3124 local64_set(&hwc
->period_left
, 0);
3127 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3132 * combine freq adjustment with unthrottling to avoid two passes over the
3133 * events. At the same time, make sure, having freq events does not change
3134 * the rate of unthrottling as that would introduce bias.
3136 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3139 struct perf_event
*event
;
3140 struct hw_perf_event
*hwc
;
3141 u64 now
, period
= TICK_NSEC
;
3145 * only need to iterate over all events iff:
3146 * - context have events in frequency mode (needs freq adjust)
3147 * - there are events to unthrottle on this cpu
3149 if (!(ctx
->nr_freq
|| needs_unthr
))
3152 raw_spin_lock(&ctx
->lock
);
3153 perf_pmu_disable(ctx
->pmu
);
3155 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3156 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3159 if (!event_filter_match(event
))
3162 perf_pmu_disable(event
->pmu
);
3166 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3167 hwc
->interrupts
= 0;
3168 perf_log_throttle(event
, 1);
3169 event
->pmu
->start(event
, 0);
3172 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3176 * stop the event and update event->count
3178 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3180 now
= local64_read(&event
->count
);
3181 delta
= now
- hwc
->freq_count_stamp
;
3182 hwc
->freq_count_stamp
= now
;
3186 * reload only if value has changed
3187 * we have stopped the event so tell that
3188 * to perf_adjust_period() to avoid stopping it
3192 perf_adjust_period(event
, period
, delta
, false);
3194 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3196 perf_pmu_enable(event
->pmu
);
3199 perf_pmu_enable(ctx
->pmu
);
3200 raw_spin_unlock(&ctx
->lock
);
3204 * Round-robin a context's events:
3206 static void rotate_ctx(struct perf_event_context
*ctx
)
3209 * Rotate the first entry last of non-pinned groups. Rotation might be
3210 * disabled by the inheritance code.
3212 if (!ctx
->rotate_disable
)
3213 list_rotate_left(&ctx
->flexible_groups
);
3216 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3218 struct perf_event_context
*ctx
= NULL
;
3221 if (cpuctx
->ctx
.nr_events
) {
3222 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3226 ctx
= cpuctx
->task_ctx
;
3227 if (ctx
&& ctx
->nr_events
) {
3228 if (ctx
->nr_events
!= ctx
->nr_active
)
3235 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3236 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3238 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3240 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3242 rotate_ctx(&cpuctx
->ctx
);
3246 perf_event_sched_in(cpuctx
, ctx
, current
);
3248 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3249 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3255 void perf_event_task_tick(void)
3257 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3258 struct perf_event_context
*ctx
, *tmp
;
3261 WARN_ON(!irqs_disabled());
3263 __this_cpu_inc(perf_throttled_seq
);
3264 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3265 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3267 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3268 perf_adjust_freq_unthr_context(ctx
, throttled
);
3271 static int event_enable_on_exec(struct perf_event
*event
,
3272 struct perf_event_context
*ctx
)
3274 if (!event
->attr
.enable_on_exec
)
3277 event
->attr
.enable_on_exec
= 0;
3278 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3281 __perf_event_mark_enabled(event
);
3287 * Enable all of a task's events that have been marked enable-on-exec.
3288 * This expects task == current.
3290 static void perf_event_enable_on_exec(int ctxn
)
3292 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3293 struct perf_cpu_context
*cpuctx
;
3294 struct perf_event
*event
;
3295 unsigned long flags
;
3298 local_irq_save(flags
);
3299 ctx
= current
->perf_event_ctxp
[ctxn
];
3300 if (!ctx
|| !ctx
->nr_events
)
3303 cpuctx
= __get_cpu_context(ctx
);
3304 perf_ctx_lock(cpuctx
, ctx
);
3305 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3306 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
3307 enabled
|= event_enable_on_exec(event
, ctx
);
3310 * Unclone and reschedule this context if we enabled any event.
3313 clone_ctx
= unclone_ctx(ctx
);
3314 ctx_resched(cpuctx
, ctx
);
3316 perf_ctx_unlock(cpuctx
, ctx
);
3319 local_irq_restore(flags
);
3325 struct perf_read_data
{
3326 struct perf_event
*event
;
3332 * Cross CPU call to read the hardware event
3334 static void __perf_event_read(void *info
)
3336 struct perf_read_data
*data
= info
;
3337 struct perf_event
*sub
, *event
= data
->event
;
3338 struct perf_event_context
*ctx
= event
->ctx
;
3339 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3340 struct pmu
*pmu
= event
->pmu
;
3343 * If this is a task context, we need to check whether it is
3344 * the current task context of this cpu. If not it has been
3345 * scheduled out before the smp call arrived. In that case
3346 * event->count would have been updated to a recent sample
3347 * when the event was scheduled out.
3349 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3352 raw_spin_lock(&ctx
->lock
);
3353 if (ctx
->is_active
) {
3354 update_context_time(ctx
);
3355 update_cgrp_time_from_event(event
);
3358 update_event_times(event
);
3359 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3368 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3372 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3373 update_event_times(sub
);
3374 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3376 * Use sibling's PMU rather than @event's since
3377 * sibling could be on different (eg: software) PMU.
3379 sub
->pmu
->read(sub
);
3383 data
->ret
= pmu
->commit_txn(pmu
);
3386 raw_spin_unlock(&ctx
->lock
);
3389 static inline u64
perf_event_count(struct perf_event
*event
)
3391 if (event
->pmu
->count
)
3392 return event
->pmu
->count(event
);
3394 return __perf_event_count(event
);
3398 * NMI-safe method to read a local event, that is an event that
3400 * - either for the current task, or for this CPU
3401 * - does not have inherit set, for inherited task events
3402 * will not be local and we cannot read them atomically
3403 * - must not have a pmu::count method
3405 u64
perf_event_read_local(struct perf_event
*event
)
3407 unsigned long flags
;
3411 * Disabling interrupts avoids all counter scheduling (context
3412 * switches, timer based rotation and IPIs).
3414 local_irq_save(flags
);
3416 /* If this is a per-task event, it must be for current */
3417 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3418 event
->hw
.target
!= current
);
3420 /* If this is a per-CPU event, it must be for this CPU */
3421 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3422 event
->cpu
!= smp_processor_id());
3425 * It must not be an event with inherit set, we cannot read
3426 * all child counters from atomic context.
3428 WARN_ON_ONCE(event
->attr
.inherit
);
3431 * It must not have a pmu::count method, those are not
3434 WARN_ON_ONCE(event
->pmu
->count
);
3437 * If the event is currently on this CPU, its either a per-task event,
3438 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3441 if (event
->oncpu
== smp_processor_id())
3442 event
->pmu
->read(event
);
3444 val
= local64_read(&event
->count
);
3445 local_irq_restore(flags
);
3450 static int perf_event_read(struct perf_event
*event
, bool group
)
3455 * If event is enabled and currently active on a CPU, update the
3456 * value in the event structure:
3458 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3459 struct perf_read_data data
= {
3464 smp_call_function_single(event
->oncpu
,
3465 __perf_event_read
, &data
, 1);
3467 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3468 struct perf_event_context
*ctx
= event
->ctx
;
3469 unsigned long flags
;
3471 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3473 * may read while context is not active
3474 * (e.g., thread is blocked), in that case
3475 * we cannot update context time
3477 if (ctx
->is_active
) {
3478 update_context_time(ctx
);
3479 update_cgrp_time_from_event(event
);
3482 update_group_times(event
);
3484 update_event_times(event
);
3485 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3492 * Initialize the perf_event context in a task_struct:
3494 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3496 raw_spin_lock_init(&ctx
->lock
);
3497 mutex_init(&ctx
->mutex
);
3498 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3499 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3500 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3501 INIT_LIST_HEAD(&ctx
->event_list
);
3502 atomic_set(&ctx
->refcount
, 1);
3505 static struct perf_event_context
*
3506 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3508 struct perf_event_context
*ctx
;
3510 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3514 __perf_event_init_context(ctx
);
3517 get_task_struct(task
);
3524 static struct task_struct
*
3525 find_lively_task_by_vpid(pid_t vpid
)
3527 struct task_struct
*task
;
3533 task
= find_task_by_vpid(vpid
);
3535 get_task_struct(task
);
3539 return ERR_PTR(-ESRCH
);
3545 * Returns a matching context with refcount and pincount.
3547 static struct perf_event_context
*
3548 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3549 struct perf_event
*event
)
3551 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3552 struct perf_cpu_context
*cpuctx
;
3553 void *task_ctx_data
= NULL
;
3554 unsigned long flags
;
3556 int cpu
= event
->cpu
;
3559 /* Must be root to operate on a CPU event: */
3560 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3561 return ERR_PTR(-EACCES
);
3564 * We could be clever and allow to attach a event to an
3565 * offline CPU and activate it when the CPU comes up, but
3568 if (!cpu_online(cpu
))
3569 return ERR_PTR(-ENODEV
);
3571 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3580 ctxn
= pmu
->task_ctx_nr
;
3584 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3585 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3586 if (!task_ctx_data
) {
3593 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3595 clone_ctx
= unclone_ctx(ctx
);
3598 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3599 ctx
->task_ctx_data
= task_ctx_data
;
3600 task_ctx_data
= NULL
;
3602 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3607 ctx
= alloc_perf_context(pmu
, task
);
3612 if (task_ctx_data
) {
3613 ctx
->task_ctx_data
= task_ctx_data
;
3614 task_ctx_data
= NULL
;
3618 mutex_lock(&task
->perf_event_mutex
);
3620 * If it has already passed perf_event_exit_task().
3621 * we must see PF_EXITING, it takes this mutex too.
3623 if (task
->flags
& PF_EXITING
)
3625 else if (task
->perf_event_ctxp
[ctxn
])
3630 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3632 mutex_unlock(&task
->perf_event_mutex
);
3634 if (unlikely(err
)) {
3643 kfree(task_ctx_data
);
3647 kfree(task_ctx_data
);
3648 return ERR_PTR(err
);
3651 static void perf_event_free_filter(struct perf_event
*event
);
3652 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3654 static void free_event_rcu(struct rcu_head
*head
)
3656 struct perf_event
*event
;
3658 event
= container_of(head
, struct perf_event
, rcu_head
);
3660 put_pid_ns(event
->ns
);
3661 perf_event_free_filter(event
);
3665 static void ring_buffer_attach(struct perf_event
*event
,
3666 struct ring_buffer
*rb
);
3668 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3673 if (is_cgroup_event(event
))
3674 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3677 #ifdef CONFIG_NO_HZ_FULL
3678 static DEFINE_SPINLOCK(nr_freq_lock
);
3681 static void unaccount_freq_event_nohz(void)
3683 #ifdef CONFIG_NO_HZ_FULL
3684 spin_lock(&nr_freq_lock
);
3685 if (atomic_dec_and_test(&nr_freq_events
))
3686 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3687 spin_unlock(&nr_freq_lock
);
3691 static void unaccount_freq_event(void)
3693 if (tick_nohz_full_enabled())
3694 unaccount_freq_event_nohz();
3696 atomic_dec(&nr_freq_events
);
3699 static void unaccount_event(struct perf_event
*event
)
3706 if (event
->attach_state
& PERF_ATTACH_TASK
)
3708 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3709 atomic_dec(&nr_mmap_events
);
3710 if (event
->attr
.comm
)
3711 atomic_dec(&nr_comm_events
);
3712 if (event
->attr
.task
)
3713 atomic_dec(&nr_task_events
);
3714 if (event
->attr
.freq
)
3715 unaccount_freq_event();
3716 if (event
->attr
.context_switch
) {
3718 atomic_dec(&nr_switch_events
);
3720 if (is_cgroup_event(event
))
3722 if (has_branch_stack(event
))
3726 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
3727 schedule_delayed_work(&perf_sched_work
, HZ
);
3730 unaccount_event_cpu(event
, event
->cpu
);
3733 static void perf_sched_delayed(struct work_struct
*work
)
3735 mutex_lock(&perf_sched_mutex
);
3736 if (atomic_dec_and_test(&perf_sched_count
))
3737 static_branch_disable(&perf_sched_events
);
3738 mutex_unlock(&perf_sched_mutex
);
3742 * The following implement mutual exclusion of events on "exclusive" pmus
3743 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3744 * at a time, so we disallow creating events that might conflict, namely:
3746 * 1) cpu-wide events in the presence of per-task events,
3747 * 2) per-task events in the presence of cpu-wide events,
3748 * 3) two matching events on the same context.
3750 * The former two cases are handled in the allocation path (perf_event_alloc(),
3751 * _free_event()), the latter -- before the first perf_install_in_context().
3753 static int exclusive_event_init(struct perf_event
*event
)
3755 struct pmu
*pmu
= event
->pmu
;
3757 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3761 * Prevent co-existence of per-task and cpu-wide events on the
3762 * same exclusive pmu.
3764 * Negative pmu::exclusive_cnt means there are cpu-wide
3765 * events on this "exclusive" pmu, positive means there are
3768 * Since this is called in perf_event_alloc() path, event::ctx
3769 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3770 * to mean "per-task event", because unlike other attach states it
3771 * never gets cleared.
3773 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3774 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3777 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3784 static void exclusive_event_destroy(struct perf_event
*event
)
3786 struct pmu
*pmu
= event
->pmu
;
3788 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3791 /* see comment in exclusive_event_init() */
3792 if (event
->attach_state
& PERF_ATTACH_TASK
)
3793 atomic_dec(&pmu
->exclusive_cnt
);
3795 atomic_inc(&pmu
->exclusive_cnt
);
3798 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3800 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3801 (e1
->cpu
== e2
->cpu
||
3808 /* Called under the same ctx::mutex as perf_install_in_context() */
3809 static bool exclusive_event_installable(struct perf_event
*event
,
3810 struct perf_event_context
*ctx
)
3812 struct perf_event
*iter_event
;
3813 struct pmu
*pmu
= event
->pmu
;
3815 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3818 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3819 if (exclusive_event_match(iter_event
, event
))
3826 static void perf_addr_filters_splice(struct perf_event
*event
,
3827 struct list_head
*head
);
3829 static void _free_event(struct perf_event
*event
)
3831 irq_work_sync(&event
->pending
);
3833 unaccount_event(event
);
3837 * Can happen when we close an event with re-directed output.
3839 * Since we have a 0 refcount, perf_mmap_close() will skip
3840 * over us; possibly making our ring_buffer_put() the last.
3842 mutex_lock(&event
->mmap_mutex
);
3843 ring_buffer_attach(event
, NULL
);
3844 mutex_unlock(&event
->mmap_mutex
);
3847 if (is_cgroup_event(event
))
3848 perf_detach_cgroup(event
);
3850 if (!event
->parent
) {
3851 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3852 put_callchain_buffers();
3855 perf_event_free_bpf_prog(event
);
3856 perf_addr_filters_splice(event
, NULL
);
3857 kfree(event
->addr_filters_offs
);
3860 event
->destroy(event
);
3863 put_ctx(event
->ctx
);
3865 exclusive_event_destroy(event
);
3866 module_put(event
->pmu
->module
);
3868 call_rcu(&event
->rcu_head
, free_event_rcu
);
3872 * Used to free events which have a known refcount of 1, such as in error paths
3873 * where the event isn't exposed yet and inherited events.
3875 static void free_event(struct perf_event
*event
)
3877 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3878 "unexpected event refcount: %ld; ptr=%p\n",
3879 atomic_long_read(&event
->refcount
), event
)) {
3880 /* leak to avoid use-after-free */
3888 * Remove user event from the owner task.
3890 static void perf_remove_from_owner(struct perf_event
*event
)
3892 struct task_struct
*owner
;
3896 * Matches the smp_store_release() in perf_event_exit_task(). If we
3897 * observe !owner it means the list deletion is complete and we can
3898 * indeed free this event, otherwise we need to serialize on
3899 * owner->perf_event_mutex.
3901 owner
= lockless_dereference(event
->owner
);
3904 * Since delayed_put_task_struct() also drops the last
3905 * task reference we can safely take a new reference
3906 * while holding the rcu_read_lock().
3908 get_task_struct(owner
);
3914 * If we're here through perf_event_exit_task() we're already
3915 * holding ctx->mutex which would be an inversion wrt. the
3916 * normal lock order.
3918 * However we can safely take this lock because its the child
3921 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3924 * We have to re-check the event->owner field, if it is cleared
3925 * we raced with perf_event_exit_task(), acquiring the mutex
3926 * ensured they're done, and we can proceed with freeing the
3930 list_del_init(&event
->owner_entry
);
3931 smp_store_release(&event
->owner
, NULL
);
3933 mutex_unlock(&owner
->perf_event_mutex
);
3934 put_task_struct(owner
);
3938 static void put_event(struct perf_event
*event
)
3940 if (!atomic_long_dec_and_test(&event
->refcount
))
3947 * Kill an event dead; while event:refcount will preserve the event
3948 * object, it will not preserve its functionality. Once the last 'user'
3949 * gives up the object, we'll destroy the thing.
3951 int perf_event_release_kernel(struct perf_event
*event
)
3953 struct perf_event_context
*ctx
= event
->ctx
;
3954 struct perf_event
*child
, *tmp
;
3957 * If we got here through err_file: fput(event_file); we will not have
3958 * attached to a context yet.
3961 WARN_ON_ONCE(event
->attach_state
&
3962 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
3966 if (!is_kernel_event(event
))
3967 perf_remove_from_owner(event
);
3969 ctx
= perf_event_ctx_lock(event
);
3970 WARN_ON_ONCE(ctx
->parent_ctx
);
3971 perf_remove_from_context(event
, DETACH_GROUP
);
3973 raw_spin_lock_irq(&ctx
->lock
);
3975 * Mark this even as STATE_DEAD, there is no external reference to it
3978 * Anybody acquiring event->child_mutex after the below loop _must_
3979 * also see this, most importantly inherit_event() which will avoid
3980 * placing more children on the list.
3982 * Thus this guarantees that we will in fact observe and kill _ALL_
3985 event
->state
= PERF_EVENT_STATE_DEAD
;
3986 raw_spin_unlock_irq(&ctx
->lock
);
3988 perf_event_ctx_unlock(event
, ctx
);
3991 mutex_lock(&event
->child_mutex
);
3992 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3995 * Cannot change, child events are not migrated, see the
3996 * comment with perf_event_ctx_lock_nested().
3998 ctx
= lockless_dereference(child
->ctx
);
4000 * Since child_mutex nests inside ctx::mutex, we must jump
4001 * through hoops. We start by grabbing a reference on the ctx.
4003 * Since the event cannot get freed while we hold the
4004 * child_mutex, the context must also exist and have a !0
4010 * Now that we have a ctx ref, we can drop child_mutex, and
4011 * acquire ctx::mutex without fear of it going away. Then we
4012 * can re-acquire child_mutex.
4014 mutex_unlock(&event
->child_mutex
);
4015 mutex_lock(&ctx
->mutex
);
4016 mutex_lock(&event
->child_mutex
);
4019 * Now that we hold ctx::mutex and child_mutex, revalidate our
4020 * state, if child is still the first entry, it didn't get freed
4021 * and we can continue doing so.
4023 tmp
= list_first_entry_or_null(&event
->child_list
,
4024 struct perf_event
, child_list
);
4026 perf_remove_from_context(child
, DETACH_GROUP
);
4027 list_del(&child
->child_list
);
4030 * This matches the refcount bump in inherit_event();
4031 * this can't be the last reference.
4036 mutex_unlock(&event
->child_mutex
);
4037 mutex_unlock(&ctx
->mutex
);
4041 mutex_unlock(&event
->child_mutex
);
4044 put_event(event
); /* Must be the 'last' reference */
4047 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4050 * Called when the last reference to the file is gone.
4052 static int perf_release(struct inode
*inode
, struct file
*file
)
4054 perf_event_release_kernel(file
->private_data
);
4058 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4060 struct perf_event
*child
;
4066 mutex_lock(&event
->child_mutex
);
4068 (void)perf_event_read(event
, false);
4069 total
+= perf_event_count(event
);
4071 *enabled
+= event
->total_time_enabled
+
4072 atomic64_read(&event
->child_total_time_enabled
);
4073 *running
+= event
->total_time_running
+
4074 atomic64_read(&event
->child_total_time_running
);
4076 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4077 (void)perf_event_read(child
, false);
4078 total
+= perf_event_count(child
);
4079 *enabled
+= child
->total_time_enabled
;
4080 *running
+= child
->total_time_running
;
4082 mutex_unlock(&event
->child_mutex
);
4086 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4088 static int __perf_read_group_add(struct perf_event
*leader
,
4089 u64 read_format
, u64
*values
)
4091 struct perf_event
*sub
;
4092 int n
= 1; /* skip @nr */
4095 ret
= perf_event_read(leader
, true);
4100 * Since we co-schedule groups, {enabled,running} times of siblings
4101 * will be identical to those of the leader, so we only publish one
4104 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4105 values
[n
++] += leader
->total_time_enabled
+
4106 atomic64_read(&leader
->child_total_time_enabled
);
4109 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4110 values
[n
++] += leader
->total_time_running
+
4111 atomic64_read(&leader
->child_total_time_running
);
4115 * Write {count,id} tuples for every sibling.
4117 values
[n
++] += perf_event_count(leader
);
4118 if (read_format
& PERF_FORMAT_ID
)
4119 values
[n
++] = primary_event_id(leader
);
4121 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4122 values
[n
++] += perf_event_count(sub
);
4123 if (read_format
& PERF_FORMAT_ID
)
4124 values
[n
++] = primary_event_id(sub
);
4130 static int perf_read_group(struct perf_event
*event
,
4131 u64 read_format
, char __user
*buf
)
4133 struct perf_event
*leader
= event
->group_leader
, *child
;
4134 struct perf_event_context
*ctx
= leader
->ctx
;
4138 lockdep_assert_held(&ctx
->mutex
);
4140 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4144 values
[0] = 1 + leader
->nr_siblings
;
4147 * By locking the child_mutex of the leader we effectively
4148 * lock the child list of all siblings.. XXX explain how.
4150 mutex_lock(&leader
->child_mutex
);
4152 ret
= __perf_read_group_add(leader
, read_format
, values
);
4156 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4157 ret
= __perf_read_group_add(child
, read_format
, values
);
4162 mutex_unlock(&leader
->child_mutex
);
4164 ret
= event
->read_size
;
4165 if (copy_to_user(buf
, values
, event
->read_size
))
4170 mutex_unlock(&leader
->child_mutex
);
4176 static int perf_read_one(struct perf_event
*event
,
4177 u64 read_format
, char __user
*buf
)
4179 u64 enabled
, running
;
4183 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4184 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4185 values
[n
++] = enabled
;
4186 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4187 values
[n
++] = running
;
4188 if (read_format
& PERF_FORMAT_ID
)
4189 values
[n
++] = primary_event_id(event
);
4191 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4194 return n
* sizeof(u64
);
4197 static bool is_event_hup(struct perf_event
*event
)
4201 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4204 mutex_lock(&event
->child_mutex
);
4205 no_children
= list_empty(&event
->child_list
);
4206 mutex_unlock(&event
->child_mutex
);
4211 * Read the performance event - simple non blocking version for now
4214 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4216 u64 read_format
= event
->attr
.read_format
;
4220 * Return end-of-file for a read on a event that is in
4221 * error state (i.e. because it was pinned but it couldn't be
4222 * scheduled on to the CPU at some point).
4224 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4227 if (count
< event
->read_size
)
4230 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4231 if (read_format
& PERF_FORMAT_GROUP
)
4232 ret
= perf_read_group(event
, read_format
, buf
);
4234 ret
= perf_read_one(event
, read_format
, buf
);
4240 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4242 struct perf_event
*event
= file
->private_data
;
4243 struct perf_event_context
*ctx
;
4246 ctx
= perf_event_ctx_lock(event
);
4247 ret
= __perf_read(event
, buf
, count
);
4248 perf_event_ctx_unlock(event
, ctx
);
4253 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4255 struct perf_event
*event
= file
->private_data
;
4256 struct ring_buffer
*rb
;
4257 unsigned int events
= POLLHUP
;
4259 poll_wait(file
, &event
->waitq
, wait
);
4261 if (is_event_hup(event
))
4265 * Pin the event->rb by taking event->mmap_mutex; otherwise
4266 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4268 mutex_lock(&event
->mmap_mutex
);
4271 events
= atomic_xchg(&rb
->poll
, 0);
4272 mutex_unlock(&event
->mmap_mutex
);
4276 static void _perf_event_reset(struct perf_event
*event
)
4278 (void)perf_event_read(event
, false);
4279 local64_set(&event
->count
, 0);
4280 perf_event_update_userpage(event
);
4284 * Holding the top-level event's child_mutex means that any
4285 * descendant process that has inherited this event will block
4286 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4287 * task existence requirements of perf_event_enable/disable.
4289 static void perf_event_for_each_child(struct perf_event
*event
,
4290 void (*func
)(struct perf_event
*))
4292 struct perf_event
*child
;
4294 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4296 mutex_lock(&event
->child_mutex
);
4298 list_for_each_entry(child
, &event
->child_list
, child_list
)
4300 mutex_unlock(&event
->child_mutex
);
4303 static void perf_event_for_each(struct perf_event
*event
,
4304 void (*func
)(struct perf_event
*))
4306 struct perf_event_context
*ctx
= event
->ctx
;
4307 struct perf_event
*sibling
;
4309 lockdep_assert_held(&ctx
->mutex
);
4311 event
= event
->group_leader
;
4313 perf_event_for_each_child(event
, func
);
4314 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4315 perf_event_for_each_child(sibling
, func
);
4318 static void __perf_event_period(struct perf_event
*event
,
4319 struct perf_cpu_context
*cpuctx
,
4320 struct perf_event_context
*ctx
,
4323 u64 value
= *((u64
*)info
);
4326 if (event
->attr
.freq
) {
4327 event
->attr
.sample_freq
= value
;
4329 event
->attr
.sample_period
= value
;
4330 event
->hw
.sample_period
= value
;
4333 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4335 perf_pmu_disable(ctx
->pmu
);
4337 * We could be throttled; unthrottle now to avoid the tick
4338 * trying to unthrottle while we already re-started the event.
4340 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4341 event
->hw
.interrupts
= 0;
4342 perf_log_throttle(event
, 1);
4344 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4347 local64_set(&event
->hw
.period_left
, 0);
4350 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4351 perf_pmu_enable(ctx
->pmu
);
4355 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4359 if (!is_sampling_event(event
))
4362 if (copy_from_user(&value
, arg
, sizeof(value
)))
4368 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4371 event_function_call(event
, __perf_event_period
, &value
);
4376 static const struct file_operations perf_fops
;
4378 static inline int perf_fget_light(int fd
, struct fd
*p
)
4380 struct fd f
= fdget(fd
);
4384 if (f
.file
->f_op
!= &perf_fops
) {
4392 static int perf_event_set_output(struct perf_event
*event
,
4393 struct perf_event
*output_event
);
4394 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4395 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4397 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4399 void (*func
)(struct perf_event
*);
4403 case PERF_EVENT_IOC_ENABLE
:
4404 func
= _perf_event_enable
;
4406 case PERF_EVENT_IOC_DISABLE
:
4407 func
= _perf_event_disable
;
4409 case PERF_EVENT_IOC_RESET
:
4410 func
= _perf_event_reset
;
4413 case PERF_EVENT_IOC_REFRESH
:
4414 return _perf_event_refresh(event
, arg
);
4416 case PERF_EVENT_IOC_PERIOD
:
4417 return perf_event_period(event
, (u64 __user
*)arg
);
4419 case PERF_EVENT_IOC_ID
:
4421 u64 id
= primary_event_id(event
);
4423 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4428 case PERF_EVENT_IOC_SET_OUTPUT
:
4432 struct perf_event
*output_event
;
4434 ret
= perf_fget_light(arg
, &output
);
4437 output_event
= output
.file
->private_data
;
4438 ret
= perf_event_set_output(event
, output_event
);
4441 ret
= perf_event_set_output(event
, NULL
);
4446 case PERF_EVENT_IOC_SET_FILTER
:
4447 return perf_event_set_filter(event
, (void __user
*)arg
);
4449 case PERF_EVENT_IOC_SET_BPF
:
4450 return perf_event_set_bpf_prog(event
, arg
);
4452 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4453 struct ring_buffer
*rb
;
4456 rb
= rcu_dereference(event
->rb
);
4457 if (!rb
|| !rb
->nr_pages
) {
4461 rb_toggle_paused(rb
, !!arg
);
4469 if (flags
& PERF_IOC_FLAG_GROUP
)
4470 perf_event_for_each(event
, func
);
4472 perf_event_for_each_child(event
, func
);
4477 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4479 struct perf_event
*event
= file
->private_data
;
4480 struct perf_event_context
*ctx
;
4483 ctx
= perf_event_ctx_lock(event
);
4484 ret
= _perf_ioctl(event
, cmd
, arg
);
4485 perf_event_ctx_unlock(event
, ctx
);
4490 #ifdef CONFIG_COMPAT
4491 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4494 switch (_IOC_NR(cmd
)) {
4495 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4496 case _IOC_NR(PERF_EVENT_IOC_ID
):
4497 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4498 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4499 cmd
&= ~IOCSIZE_MASK
;
4500 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4504 return perf_ioctl(file
, cmd
, arg
);
4507 # define perf_compat_ioctl NULL
4510 int perf_event_task_enable(void)
4512 struct perf_event_context
*ctx
;
4513 struct perf_event
*event
;
4515 mutex_lock(¤t
->perf_event_mutex
);
4516 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4517 ctx
= perf_event_ctx_lock(event
);
4518 perf_event_for_each_child(event
, _perf_event_enable
);
4519 perf_event_ctx_unlock(event
, ctx
);
4521 mutex_unlock(¤t
->perf_event_mutex
);
4526 int perf_event_task_disable(void)
4528 struct perf_event_context
*ctx
;
4529 struct perf_event
*event
;
4531 mutex_lock(¤t
->perf_event_mutex
);
4532 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4533 ctx
= perf_event_ctx_lock(event
);
4534 perf_event_for_each_child(event
, _perf_event_disable
);
4535 perf_event_ctx_unlock(event
, ctx
);
4537 mutex_unlock(¤t
->perf_event_mutex
);
4542 static int perf_event_index(struct perf_event
*event
)
4544 if (event
->hw
.state
& PERF_HES_STOPPED
)
4547 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4550 return event
->pmu
->event_idx(event
);
4553 static void calc_timer_values(struct perf_event
*event
,
4560 *now
= perf_clock();
4561 ctx_time
= event
->shadow_ctx_time
+ *now
;
4562 *enabled
= ctx_time
- event
->tstamp_enabled
;
4563 *running
= ctx_time
- event
->tstamp_running
;
4566 static void perf_event_init_userpage(struct perf_event
*event
)
4568 struct perf_event_mmap_page
*userpg
;
4569 struct ring_buffer
*rb
;
4572 rb
= rcu_dereference(event
->rb
);
4576 userpg
= rb
->user_page
;
4578 /* Allow new userspace to detect that bit 0 is deprecated */
4579 userpg
->cap_bit0_is_deprecated
= 1;
4580 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4581 userpg
->data_offset
= PAGE_SIZE
;
4582 userpg
->data_size
= perf_data_size(rb
);
4588 void __weak
arch_perf_update_userpage(
4589 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4594 * Callers need to ensure there can be no nesting of this function, otherwise
4595 * the seqlock logic goes bad. We can not serialize this because the arch
4596 * code calls this from NMI context.
4598 void perf_event_update_userpage(struct perf_event
*event
)
4600 struct perf_event_mmap_page
*userpg
;
4601 struct ring_buffer
*rb
;
4602 u64 enabled
, running
, now
;
4605 rb
= rcu_dereference(event
->rb
);
4610 * compute total_time_enabled, total_time_running
4611 * based on snapshot values taken when the event
4612 * was last scheduled in.
4614 * we cannot simply called update_context_time()
4615 * because of locking issue as we can be called in
4618 calc_timer_values(event
, &now
, &enabled
, &running
);
4620 userpg
= rb
->user_page
;
4622 * Disable preemption so as to not let the corresponding user-space
4623 * spin too long if we get preempted.
4628 userpg
->index
= perf_event_index(event
);
4629 userpg
->offset
= perf_event_count(event
);
4631 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4633 userpg
->time_enabled
= enabled
+
4634 atomic64_read(&event
->child_total_time_enabled
);
4636 userpg
->time_running
= running
+
4637 atomic64_read(&event
->child_total_time_running
);
4639 arch_perf_update_userpage(event
, userpg
, now
);
4648 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4650 struct perf_event
*event
= vma
->vm_file
->private_data
;
4651 struct ring_buffer
*rb
;
4652 int ret
= VM_FAULT_SIGBUS
;
4654 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4655 if (vmf
->pgoff
== 0)
4661 rb
= rcu_dereference(event
->rb
);
4665 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4668 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4672 get_page(vmf
->page
);
4673 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4674 vmf
->page
->index
= vmf
->pgoff
;
4683 static void ring_buffer_attach(struct perf_event
*event
,
4684 struct ring_buffer
*rb
)
4686 struct ring_buffer
*old_rb
= NULL
;
4687 unsigned long flags
;
4691 * Should be impossible, we set this when removing
4692 * event->rb_entry and wait/clear when adding event->rb_entry.
4694 WARN_ON_ONCE(event
->rcu_pending
);
4697 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4698 list_del_rcu(&event
->rb_entry
);
4699 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4701 event
->rcu_batches
= get_state_synchronize_rcu();
4702 event
->rcu_pending
= 1;
4706 if (event
->rcu_pending
) {
4707 cond_synchronize_rcu(event
->rcu_batches
);
4708 event
->rcu_pending
= 0;
4711 spin_lock_irqsave(&rb
->event_lock
, flags
);
4712 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4713 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4716 rcu_assign_pointer(event
->rb
, rb
);
4719 ring_buffer_put(old_rb
);
4721 * Since we detached before setting the new rb, so that we
4722 * could attach the new rb, we could have missed a wakeup.
4725 wake_up_all(&event
->waitq
);
4729 static void ring_buffer_wakeup(struct perf_event
*event
)
4731 struct ring_buffer
*rb
;
4734 rb
= rcu_dereference(event
->rb
);
4736 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4737 wake_up_all(&event
->waitq
);
4742 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4744 struct ring_buffer
*rb
;
4747 rb
= rcu_dereference(event
->rb
);
4749 if (!atomic_inc_not_zero(&rb
->refcount
))
4757 void ring_buffer_put(struct ring_buffer
*rb
)
4759 if (!atomic_dec_and_test(&rb
->refcount
))
4762 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4764 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4767 static void perf_mmap_open(struct vm_area_struct
*vma
)
4769 struct perf_event
*event
= vma
->vm_file
->private_data
;
4771 atomic_inc(&event
->mmap_count
);
4772 atomic_inc(&event
->rb
->mmap_count
);
4775 atomic_inc(&event
->rb
->aux_mmap_count
);
4777 if (event
->pmu
->event_mapped
)
4778 event
->pmu
->event_mapped(event
);
4781 static void perf_pmu_output_stop(struct perf_event
*event
);
4784 * A buffer can be mmap()ed multiple times; either directly through the same
4785 * event, or through other events by use of perf_event_set_output().
4787 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4788 * the buffer here, where we still have a VM context. This means we need
4789 * to detach all events redirecting to us.
4791 static void perf_mmap_close(struct vm_area_struct
*vma
)
4793 struct perf_event
*event
= vma
->vm_file
->private_data
;
4795 struct ring_buffer
*rb
= ring_buffer_get(event
);
4796 struct user_struct
*mmap_user
= rb
->mmap_user
;
4797 int mmap_locked
= rb
->mmap_locked
;
4798 unsigned long size
= perf_data_size(rb
);
4800 if (event
->pmu
->event_unmapped
)
4801 event
->pmu
->event_unmapped(event
);
4804 * rb->aux_mmap_count will always drop before rb->mmap_count and
4805 * event->mmap_count, so it is ok to use event->mmap_mutex to
4806 * serialize with perf_mmap here.
4808 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4809 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4811 * Stop all AUX events that are writing to this buffer,
4812 * so that we can free its AUX pages and corresponding PMU
4813 * data. Note that after rb::aux_mmap_count dropped to zero,
4814 * they won't start any more (see perf_aux_output_begin()).
4816 perf_pmu_output_stop(event
);
4818 /* now it's safe to free the pages */
4819 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4820 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4822 /* this has to be the last one */
4824 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
4826 mutex_unlock(&event
->mmap_mutex
);
4829 atomic_dec(&rb
->mmap_count
);
4831 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4834 ring_buffer_attach(event
, NULL
);
4835 mutex_unlock(&event
->mmap_mutex
);
4837 /* If there's still other mmap()s of this buffer, we're done. */
4838 if (atomic_read(&rb
->mmap_count
))
4842 * No other mmap()s, detach from all other events that might redirect
4843 * into the now unreachable buffer. Somewhat complicated by the
4844 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4848 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4849 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4851 * This event is en-route to free_event() which will
4852 * detach it and remove it from the list.
4858 mutex_lock(&event
->mmap_mutex
);
4860 * Check we didn't race with perf_event_set_output() which can
4861 * swizzle the rb from under us while we were waiting to
4862 * acquire mmap_mutex.
4864 * If we find a different rb; ignore this event, a next
4865 * iteration will no longer find it on the list. We have to
4866 * still restart the iteration to make sure we're not now
4867 * iterating the wrong list.
4869 if (event
->rb
== rb
)
4870 ring_buffer_attach(event
, NULL
);
4872 mutex_unlock(&event
->mmap_mutex
);
4876 * Restart the iteration; either we're on the wrong list or
4877 * destroyed its integrity by doing a deletion.
4884 * It could be there's still a few 0-ref events on the list; they'll
4885 * get cleaned up by free_event() -- they'll also still have their
4886 * ref on the rb and will free it whenever they are done with it.
4888 * Aside from that, this buffer is 'fully' detached and unmapped,
4889 * undo the VM accounting.
4892 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4893 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4894 free_uid(mmap_user
);
4897 ring_buffer_put(rb
); /* could be last */
4900 static const struct vm_operations_struct perf_mmap_vmops
= {
4901 .open
= perf_mmap_open
,
4902 .close
= perf_mmap_close
, /* non mergable */
4903 .fault
= perf_mmap_fault
,
4904 .page_mkwrite
= perf_mmap_fault
,
4907 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4909 struct perf_event
*event
= file
->private_data
;
4910 unsigned long user_locked
, user_lock_limit
;
4911 struct user_struct
*user
= current_user();
4912 unsigned long locked
, lock_limit
;
4913 struct ring_buffer
*rb
= NULL
;
4914 unsigned long vma_size
;
4915 unsigned long nr_pages
;
4916 long user_extra
= 0, extra
= 0;
4917 int ret
= 0, flags
= 0;
4920 * Don't allow mmap() of inherited per-task counters. This would
4921 * create a performance issue due to all children writing to the
4924 if (event
->cpu
== -1 && event
->attr
.inherit
)
4927 if (!(vma
->vm_flags
& VM_SHARED
))
4930 vma_size
= vma
->vm_end
- vma
->vm_start
;
4932 if (vma
->vm_pgoff
== 0) {
4933 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4936 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4937 * mapped, all subsequent mappings should have the same size
4938 * and offset. Must be above the normal perf buffer.
4940 u64 aux_offset
, aux_size
;
4945 nr_pages
= vma_size
/ PAGE_SIZE
;
4947 mutex_lock(&event
->mmap_mutex
);
4954 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4955 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4957 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4960 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4963 /* already mapped with a different offset */
4964 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4967 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4970 /* already mapped with a different size */
4971 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4974 if (!is_power_of_2(nr_pages
))
4977 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4980 if (rb_has_aux(rb
)) {
4981 atomic_inc(&rb
->aux_mmap_count
);
4986 atomic_set(&rb
->aux_mmap_count
, 1);
4987 user_extra
= nr_pages
;
4993 * If we have rb pages ensure they're a power-of-two number, so we
4994 * can do bitmasks instead of modulo.
4996 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4999 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5002 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5004 mutex_lock(&event
->mmap_mutex
);
5006 if (event
->rb
->nr_pages
!= nr_pages
) {
5011 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5013 * Raced against perf_mmap_close() through
5014 * perf_event_set_output(). Try again, hope for better
5017 mutex_unlock(&event
->mmap_mutex
);
5024 user_extra
= nr_pages
+ 1;
5027 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5030 * Increase the limit linearly with more CPUs:
5032 user_lock_limit
*= num_online_cpus();
5034 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5036 if (user_locked
> user_lock_limit
)
5037 extra
= user_locked
- user_lock_limit
;
5039 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5040 lock_limit
>>= PAGE_SHIFT
;
5041 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5043 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5044 !capable(CAP_IPC_LOCK
)) {
5049 WARN_ON(!rb
&& event
->rb
);
5051 if (vma
->vm_flags
& VM_WRITE
)
5052 flags
|= RING_BUFFER_WRITABLE
;
5055 rb
= rb_alloc(nr_pages
,
5056 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5064 atomic_set(&rb
->mmap_count
, 1);
5065 rb
->mmap_user
= get_current_user();
5066 rb
->mmap_locked
= extra
;
5068 ring_buffer_attach(event
, rb
);
5070 perf_event_init_userpage(event
);
5071 perf_event_update_userpage(event
);
5073 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5074 event
->attr
.aux_watermark
, flags
);
5076 rb
->aux_mmap_locked
= extra
;
5081 atomic_long_add(user_extra
, &user
->locked_vm
);
5082 vma
->vm_mm
->pinned_vm
+= extra
;
5084 atomic_inc(&event
->mmap_count
);
5086 atomic_dec(&rb
->mmap_count
);
5089 mutex_unlock(&event
->mmap_mutex
);
5092 * Since pinned accounting is per vm we cannot allow fork() to copy our
5095 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5096 vma
->vm_ops
= &perf_mmap_vmops
;
5098 if (event
->pmu
->event_mapped
)
5099 event
->pmu
->event_mapped(event
);
5104 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5106 struct inode
*inode
= file_inode(filp
);
5107 struct perf_event
*event
= filp
->private_data
;
5111 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5112 inode_unlock(inode
);
5120 static const struct file_operations perf_fops
= {
5121 .llseek
= no_llseek
,
5122 .release
= perf_release
,
5125 .unlocked_ioctl
= perf_ioctl
,
5126 .compat_ioctl
= perf_compat_ioctl
,
5128 .fasync
= perf_fasync
,
5134 * If there's data, ensure we set the poll() state and publish everything
5135 * to user-space before waking everybody up.
5138 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5140 /* only the parent has fasync state */
5142 event
= event
->parent
;
5143 return &event
->fasync
;
5146 void perf_event_wakeup(struct perf_event
*event
)
5148 ring_buffer_wakeup(event
);
5150 if (event
->pending_kill
) {
5151 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5152 event
->pending_kill
= 0;
5156 static void perf_pending_event(struct irq_work
*entry
)
5158 struct perf_event
*event
= container_of(entry
,
5159 struct perf_event
, pending
);
5162 rctx
= perf_swevent_get_recursion_context();
5164 * If we 'fail' here, that's OK, it means recursion is already disabled
5165 * and we won't recurse 'further'.
5168 if (event
->pending_disable
) {
5169 event
->pending_disable
= 0;
5170 perf_event_disable_local(event
);
5173 if (event
->pending_wakeup
) {
5174 event
->pending_wakeup
= 0;
5175 perf_event_wakeup(event
);
5179 perf_swevent_put_recursion_context(rctx
);
5183 * We assume there is only KVM supporting the callbacks.
5184 * Later on, we might change it to a list if there is
5185 * another virtualization implementation supporting the callbacks.
5187 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5189 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5191 perf_guest_cbs
= cbs
;
5194 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5196 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5198 perf_guest_cbs
= NULL
;
5201 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5204 perf_output_sample_regs(struct perf_output_handle
*handle
,
5205 struct pt_regs
*regs
, u64 mask
)
5209 for_each_set_bit(bit
, (const unsigned long *) &mask
,
5210 sizeof(mask
) * BITS_PER_BYTE
) {
5213 val
= perf_reg_value(regs
, bit
);
5214 perf_output_put(handle
, val
);
5218 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5219 struct pt_regs
*regs
,
5220 struct pt_regs
*regs_user_copy
)
5222 if (user_mode(regs
)) {
5223 regs_user
->abi
= perf_reg_abi(current
);
5224 regs_user
->regs
= regs
;
5225 } else if (current
->mm
) {
5226 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5228 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5229 regs_user
->regs
= NULL
;
5233 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5234 struct pt_regs
*regs
)
5236 regs_intr
->regs
= regs
;
5237 regs_intr
->abi
= perf_reg_abi(current
);
5242 * Get remaining task size from user stack pointer.
5244 * It'd be better to take stack vma map and limit this more
5245 * precisly, but there's no way to get it safely under interrupt,
5246 * so using TASK_SIZE as limit.
5248 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5250 unsigned long addr
= perf_user_stack_pointer(regs
);
5252 if (!addr
|| addr
>= TASK_SIZE
)
5255 return TASK_SIZE
- addr
;
5259 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5260 struct pt_regs
*regs
)
5264 /* No regs, no stack pointer, no dump. */
5269 * Check if we fit in with the requested stack size into the:
5271 * If we don't, we limit the size to the TASK_SIZE.
5273 * - remaining sample size
5274 * If we don't, we customize the stack size to
5275 * fit in to the remaining sample size.
5278 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5279 stack_size
= min(stack_size
, (u16
) task_size
);
5281 /* Current header size plus static size and dynamic size. */
5282 header_size
+= 2 * sizeof(u64
);
5284 /* Do we fit in with the current stack dump size? */
5285 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5287 * If we overflow the maximum size for the sample,
5288 * we customize the stack dump size to fit in.
5290 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5291 stack_size
= round_up(stack_size
, sizeof(u64
));
5298 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5299 struct pt_regs
*regs
)
5301 /* Case of a kernel thread, nothing to dump */
5304 perf_output_put(handle
, size
);
5313 * - the size requested by user or the best one we can fit
5314 * in to the sample max size
5316 * - user stack dump data
5318 * - the actual dumped size
5322 perf_output_put(handle
, dump_size
);
5325 sp
= perf_user_stack_pointer(regs
);
5326 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5327 dyn_size
= dump_size
- rem
;
5329 perf_output_skip(handle
, rem
);
5332 perf_output_put(handle
, dyn_size
);
5336 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5337 struct perf_sample_data
*data
,
5338 struct perf_event
*event
)
5340 u64 sample_type
= event
->attr
.sample_type
;
5342 data
->type
= sample_type
;
5343 header
->size
+= event
->id_header_size
;
5345 if (sample_type
& PERF_SAMPLE_TID
) {
5346 /* namespace issues */
5347 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5348 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5351 if (sample_type
& PERF_SAMPLE_TIME
)
5352 data
->time
= perf_event_clock(event
);
5354 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5355 data
->id
= primary_event_id(event
);
5357 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5358 data
->stream_id
= event
->id
;
5360 if (sample_type
& PERF_SAMPLE_CPU
) {
5361 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5362 data
->cpu_entry
.reserved
= 0;
5366 void perf_event_header__init_id(struct perf_event_header
*header
,
5367 struct perf_sample_data
*data
,
5368 struct perf_event
*event
)
5370 if (event
->attr
.sample_id_all
)
5371 __perf_event_header__init_id(header
, data
, event
);
5374 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5375 struct perf_sample_data
*data
)
5377 u64 sample_type
= data
->type
;
5379 if (sample_type
& PERF_SAMPLE_TID
)
5380 perf_output_put(handle
, data
->tid_entry
);
5382 if (sample_type
& PERF_SAMPLE_TIME
)
5383 perf_output_put(handle
, data
->time
);
5385 if (sample_type
& PERF_SAMPLE_ID
)
5386 perf_output_put(handle
, data
->id
);
5388 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5389 perf_output_put(handle
, data
->stream_id
);
5391 if (sample_type
& PERF_SAMPLE_CPU
)
5392 perf_output_put(handle
, data
->cpu_entry
);
5394 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5395 perf_output_put(handle
, data
->id
);
5398 void perf_event__output_id_sample(struct perf_event
*event
,
5399 struct perf_output_handle
*handle
,
5400 struct perf_sample_data
*sample
)
5402 if (event
->attr
.sample_id_all
)
5403 __perf_event__output_id_sample(handle
, sample
);
5406 static void perf_output_read_one(struct perf_output_handle
*handle
,
5407 struct perf_event
*event
,
5408 u64 enabled
, u64 running
)
5410 u64 read_format
= event
->attr
.read_format
;
5414 values
[n
++] = perf_event_count(event
);
5415 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5416 values
[n
++] = enabled
+
5417 atomic64_read(&event
->child_total_time_enabled
);
5419 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5420 values
[n
++] = running
+
5421 atomic64_read(&event
->child_total_time_running
);
5423 if (read_format
& PERF_FORMAT_ID
)
5424 values
[n
++] = primary_event_id(event
);
5426 __output_copy(handle
, values
, n
* sizeof(u64
));
5430 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5432 static void perf_output_read_group(struct perf_output_handle
*handle
,
5433 struct perf_event
*event
,
5434 u64 enabled
, u64 running
)
5436 struct perf_event
*leader
= event
->group_leader
, *sub
;
5437 u64 read_format
= event
->attr
.read_format
;
5441 values
[n
++] = 1 + leader
->nr_siblings
;
5443 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5444 values
[n
++] = enabled
;
5446 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5447 values
[n
++] = running
;
5449 if (leader
!= event
)
5450 leader
->pmu
->read(leader
);
5452 values
[n
++] = perf_event_count(leader
);
5453 if (read_format
& PERF_FORMAT_ID
)
5454 values
[n
++] = primary_event_id(leader
);
5456 __output_copy(handle
, values
, n
* sizeof(u64
));
5458 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5461 if ((sub
!= event
) &&
5462 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5463 sub
->pmu
->read(sub
);
5465 values
[n
++] = perf_event_count(sub
);
5466 if (read_format
& PERF_FORMAT_ID
)
5467 values
[n
++] = primary_event_id(sub
);
5469 __output_copy(handle
, values
, n
* sizeof(u64
));
5473 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5474 PERF_FORMAT_TOTAL_TIME_RUNNING)
5476 static void perf_output_read(struct perf_output_handle
*handle
,
5477 struct perf_event
*event
)
5479 u64 enabled
= 0, running
= 0, now
;
5480 u64 read_format
= event
->attr
.read_format
;
5483 * compute total_time_enabled, total_time_running
5484 * based on snapshot values taken when the event
5485 * was last scheduled in.
5487 * we cannot simply called update_context_time()
5488 * because of locking issue as we are called in
5491 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5492 calc_timer_values(event
, &now
, &enabled
, &running
);
5494 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5495 perf_output_read_group(handle
, event
, enabled
, running
);
5497 perf_output_read_one(handle
, event
, enabled
, running
);
5500 void perf_output_sample(struct perf_output_handle
*handle
,
5501 struct perf_event_header
*header
,
5502 struct perf_sample_data
*data
,
5503 struct perf_event
*event
)
5505 u64 sample_type
= data
->type
;
5507 perf_output_put(handle
, *header
);
5509 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5510 perf_output_put(handle
, data
->id
);
5512 if (sample_type
& PERF_SAMPLE_IP
)
5513 perf_output_put(handle
, data
->ip
);
5515 if (sample_type
& PERF_SAMPLE_TID
)
5516 perf_output_put(handle
, data
->tid_entry
);
5518 if (sample_type
& PERF_SAMPLE_TIME
)
5519 perf_output_put(handle
, data
->time
);
5521 if (sample_type
& PERF_SAMPLE_ADDR
)
5522 perf_output_put(handle
, data
->addr
);
5524 if (sample_type
& PERF_SAMPLE_ID
)
5525 perf_output_put(handle
, data
->id
);
5527 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5528 perf_output_put(handle
, data
->stream_id
);
5530 if (sample_type
& PERF_SAMPLE_CPU
)
5531 perf_output_put(handle
, data
->cpu_entry
);
5533 if (sample_type
& PERF_SAMPLE_PERIOD
)
5534 perf_output_put(handle
, data
->period
);
5536 if (sample_type
& PERF_SAMPLE_READ
)
5537 perf_output_read(handle
, event
);
5539 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5540 if (data
->callchain
) {
5543 if (data
->callchain
)
5544 size
+= data
->callchain
->nr
;
5546 size
*= sizeof(u64
);
5548 __output_copy(handle
, data
->callchain
, size
);
5551 perf_output_put(handle
, nr
);
5555 if (sample_type
& PERF_SAMPLE_RAW
) {
5557 u32 raw_size
= data
->raw
->size
;
5558 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5559 sizeof(u64
)) - sizeof(u32
);
5562 perf_output_put(handle
, real_size
);
5563 __output_copy(handle
, data
->raw
->data
, raw_size
);
5564 if (real_size
- raw_size
)
5565 __output_copy(handle
, &zero
, real_size
- raw_size
);
5571 .size
= sizeof(u32
),
5574 perf_output_put(handle
, raw
);
5578 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5579 if (data
->br_stack
) {
5582 size
= data
->br_stack
->nr
5583 * sizeof(struct perf_branch_entry
);
5585 perf_output_put(handle
, data
->br_stack
->nr
);
5586 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5589 * we always store at least the value of nr
5592 perf_output_put(handle
, nr
);
5596 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5597 u64 abi
= data
->regs_user
.abi
;
5600 * If there are no regs to dump, notice it through
5601 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5603 perf_output_put(handle
, abi
);
5606 u64 mask
= event
->attr
.sample_regs_user
;
5607 perf_output_sample_regs(handle
,
5608 data
->regs_user
.regs
,
5613 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5614 perf_output_sample_ustack(handle
,
5615 data
->stack_user_size
,
5616 data
->regs_user
.regs
);
5619 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5620 perf_output_put(handle
, data
->weight
);
5622 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5623 perf_output_put(handle
, data
->data_src
.val
);
5625 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5626 perf_output_put(handle
, data
->txn
);
5628 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5629 u64 abi
= data
->regs_intr
.abi
;
5631 * If there are no regs to dump, notice it through
5632 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5634 perf_output_put(handle
, abi
);
5637 u64 mask
= event
->attr
.sample_regs_intr
;
5639 perf_output_sample_regs(handle
,
5640 data
->regs_intr
.regs
,
5645 if (!event
->attr
.watermark
) {
5646 int wakeup_events
= event
->attr
.wakeup_events
;
5648 if (wakeup_events
) {
5649 struct ring_buffer
*rb
= handle
->rb
;
5650 int events
= local_inc_return(&rb
->events
);
5652 if (events
>= wakeup_events
) {
5653 local_sub(wakeup_events
, &rb
->events
);
5654 local_inc(&rb
->wakeup
);
5660 void perf_prepare_sample(struct perf_event_header
*header
,
5661 struct perf_sample_data
*data
,
5662 struct perf_event
*event
,
5663 struct pt_regs
*regs
)
5665 u64 sample_type
= event
->attr
.sample_type
;
5667 header
->type
= PERF_RECORD_SAMPLE
;
5668 header
->size
= sizeof(*header
) + event
->header_size
;
5671 header
->misc
|= perf_misc_flags(regs
);
5673 __perf_event_header__init_id(header
, data
, event
);
5675 if (sample_type
& PERF_SAMPLE_IP
)
5676 data
->ip
= perf_instruction_pointer(regs
);
5678 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5681 data
->callchain
= perf_callchain(event
, regs
);
5683 if (data
->callchain
)
5684 size
+= data
->callchain
->nr
;
5686 header
->size
+= size
* sizeof(u64
);
5689 if (sample_type
& PERF_SAMPLE_RAW
) {
5690 int size
= sizeof(u32
);
5693 size
+= data
->raw
->size
;
5695 size
+= sizeof(u32
);
5697 header
->size
+= round_up(size
, sizeof(u64
));
5700 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5701 int size
= sizeof(u64
); /* nr */
5702 if (data
->br_stack
) {
5703 size
+= data
->br_stack
->nr
5704 * sizeof(struct perf_branch_entry
);
5706 header
->size
+= size
;
5709 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5710 perf_sample_regs_user(&data
->regs_user
, regs
,
5711 &data
->regs_user_copy
);
5713 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5714 /* regs dump ABI info */
5715 int size
= sizeof(u64
);
5717 if (data
->regs_user
.regs
) {
5718 u64 mask
= event
->attr
.sample_regs_user
;
5719 size
+= hweight64(mask
) * sizeof(u64
);
5722 header
->size
+= size
;
5725 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5727 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5728 * processed as the last one or have additional check added
5729 * in case new sample type is added, because we could eat
5730 * up the rest of the sample size.
5732 u16 stack_size
= event
->attr
.sample_stack_user
;
5733 u16 size
= sizeof(u64
);
5735 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5736 data
->regs_user
.regs
);
5739 * If there is something to dump, add space for the dump
5740 * itself and for the field that tells the dynamic size,
5741 * which is how many have been actually dumped.
5744 size
+= sizeof(u64
) + stack_size
;
5746 data
->stack_user_size
= stack_size
;
5747 header
->size
+= size
;
5750 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5751 /* regs dump ABI info */
5752 int size
= sizeof(u64
);
5754 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5756 if (data
->regs_intr
.regs
) {
5757 u64 mask
= event
->attr
.sample_regs_intr
;
5759 size
+= hweight64(mask
) * sizeof(u64
);
5762 header
->size
+= size
;
5766 static void __always_inline
5767 __perf_event_output(struct perf_event
*event
,
5768 struct perf_sample_data
*data
,
5769 struct pt_regs
*regs
,
5770 int (*output_begin
)(struct perf_output_handle
*,
5771 struct perf_event
*,
5774 struct perf_output_handle handle
;
5775 struct perf_event_header header
;
5777 /* protect the callchain buffers */
5780 perf_prepare_sample(&header
, data
, event
, regs
);
5782 if (output_begin(&handle
, event
, header
.size
))
5785 perf_output_sample(&handle
, &header
, data
, event
);
5787 perf_output_end(&handle
);
5794 perf_event_output_forward(struct perf_event
*event
,
5795 struct perf_sample_data
*data
,
5796 struct pt_regs
*regs
)
5798 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
5802 perf_event_output_backward(struct perf_event
*event
,
5803 struct perf_sample_data
*data
,
5804 struct pt_regs
*regs
)
5806 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
5810 perf_event_output(struct perf_event
*event
,
5811 struct perf_sample_data
*data
,
5812 struct pt_regs
*regs
)
5814 __perf_event_output(event
, data
, regs
, perf_output_begin
);
5821 struct perf_read_event
{
5822 struct perf_event_header header
;
5829 perf_event_read_event(struct perf_event
*event
,
5830 struct task_struct
*task
)
5832 struct perf_output_handle handle
;
5833 struct perf_sample_data sample
;
5834 struct perf_read_event read_event
= {
5836 .type
= PERF_RECORD_READ
,
5838 .size
= sizeof(read_event
) + event
->read_size
,
5840 .pid
= perf_event_pid(event
, task
),
5841 .tid
= perf_event_tid(event
, task
),
5845 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5846 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5850 perf_output_put(&handle
, read_event
);
5851 perf_output_read(&handle
, event
);
5852 perf_event__output_id_sample(event
, &handle
, &sample
);
5854 perf_output_end(&handle
);
5857 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5860 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5861 perf_event_aux_output_cb output
,
5862 void *data
, bool all
)
5864 struct perf_event
*event
;
5866 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5868 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5870 if (!event_filter_match(event
))
5874 output(event
, data
);
5879 perf_event_aux_task_ctx(perf_event_aux_output_cb output
, void *data
,
5880 struct perf_event_context
*task_ctx
)
5884 perf_event_aux_ctx(task_ctx
, output
, data
, false);
5890 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5891 struct perf_event_context
*task_ctx
)
5893 struct perf_cpu_context
*cpuctx
;
5894 struct perf_event_context
*ctx
;
5899 * If we have task_ctx != NULL we only notify
5900 * the task context itself. The task_ctx is set
5901 * only for EXIT events before releasing task
5905 perf_event_aux_task_ctx(output
, data
, task_ctx
);
5910 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5911 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5912 if (cpuctx
->unique_pmu
!= pmu
)
5914 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
, false);
5915 ctxn
= pmu
->task_ctx_nr
;
5918 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5920 perf_event_aux_ctx(ctx
, output
, data
, false);
5922 put_cpu_ptr(pmu
->pmu_cpu_context
);
5928 * Clear all file-based filters at exec, they'll have to be
5929 * re-instated when/if these objects are mmapped again.
5931 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
5933 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
5934 struct perf_addr_filter
*filter
;
5935 unsigned int restart
= 0, count
= 0;
5936 unsigned long flags
;
5938 if (!has_addr_filter(event
))
5941 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
5942 list_for_each_entry(filter
, &ifh
->list
, entry
) {
5943 if (filter
->inode
) {
5944 event
->addr_filters_offs
[count
] = 0;
5952 event
->addr_filters_gen
++;
5953 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
5956 perf_event_restart(event
);
5959 void perf_event_exec(void)
5961 struct perf_event_context
*ctx
;
5965 for_each_task_context_nr(ctxn
) {
5966 ctx
= current
->perf_event_ctxp
[ctxn
];
5970 perf_event_enable_on_exec(ctxn
);
5972 perf_event_aux_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
5978 struct remote_output
{
5979 struct ring_buffer
*rb
;
5983 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
5985 struct perf_event
*parent
= event
->parent
;
5986 struct remote_output
*ro
= data
;
5987 struct ring_buffer
*rb
= ro
->rb
;
5988 struct stop_event_data sd
= {
5992 if (!has_aux(event
))
5999 * In case of inheritance, it will be the parent that links to the
6000 * ring-buffer, but it will be the child that's actually using it:
6002 if (rcu_dereference(parent
->rb
) == rb
)
6003 ro
->err
= __perf_event_stop(&sd
);
6006 static int __perf_pmu_output_stop(void *info
)
6008 struct perf_event
*event
= info
;
6009 struct pmu
*pmu
= event
->pmu
;
6010 struct perf_cpu_context
*cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
6011 struct remote_output ro
= {
6016 perf_event_aux_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6017 if (cpuctx
->task_ctx
)
6018 perf_event_aux_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6025 static void perf_pmu_output_stop(struct perf_event
*event
)
6027 struct perf_event
*iter
;
6032 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6034 * For per-CPU events, we need to make sure that neither they
6035 * nor their children are running; for cpu==-1 events it's
6036 * sufficient to stop the event itself if it's active, since
6037 * it can't have children.
6041 cpu
= READ_ONCE(iter
->oncpu
);
6046 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6047 if (err
== -EAGAIN
) {
6056 * task tracking -- fork/exit
6058 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6061 struct perf_task_event
{
6062 struct task_struct
*task
;
6063 struct perf_event_context
*task_ctx
;
6066 struct perf_event_header header
;
6076 static int perf_event_task_match(struct perf_event
*event
)
6078 return event
->attr
.comm
|| event
->attr
.mmap
||
6079 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6083 static void perf_event_task_output(struct perf_event
*event
,
6086 struct perf_task_event
*task_event
= data
;
6087 struct perf_output_handle handle
;
6088 struct perf_sample_data sample
;
6089 struct task_struct
*task
= task_event
->task
;
6090 int ret
, size
= task_event
->event_id
.header
.size
;
6092 if (!perf_event_task_match(event
))
6095 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6097 ret
= perf_output_begin(&handle
, event
,
6098 task_event
->event_id
.header
.size
);
6102 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6103 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6105 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6106 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6108 task_event
->event_id
.time
= perf_event_clock(event
);
6110 perf_output_put(&handle
, task_event
->event_id
);
6112 perf_event__output_id_sample(event
, &handle
, &sample
);
6114 perf_output_end(&handle
);
6116 task_event
->event_id
.header
.size
= size
;
6119 static void perf_event_task(struct task_struct
*task
,
6120 struct perf_event_context
*task_ctx
,
6123 struct perf_task_event task_event
;
6125 if (!atomic_read(&nr_comm_events
) &&
6126 !atomic_read(&nr_mmap_events
) &&
6127 !atomic_read(&nr_task_events
))
6130 task_event
= (struct perf_task_event
){
6132 .task_ctx
= task_ctx
,
6135 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6137 .size
= sizeof(task_event
.event_id
),
6147 perf_event_aux(perf_event_task_output
,
6152 void perf_event_fork(struct task_struct
*task
)
6154 perf_event_task(task
, NULL
, 1);
6161 struct perf_comm_event
{
6162 struct task_struct
*task
;
6167 struct perf_event_header header
;
6174 static int perf_event_comm_match(struct perf_event
*event
)
6176 return event
->attr
.comm
;
6179 static void perf_event_comm_output(struct perf_event
*event
,
6182 struct perf_comm_event
*comm_event
= data
;
6183 struct perf_output_handle handle
;
6184 struct perf_sample_data sample
;
6185 int size
= comm_event
->event_id
.header
.size
;
6188 if (!perf_event_comm_match(event
))
6191 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6192 ret
= perf_output_begin(&handle
, event
,
6193 comm_event
->event_id
.header
.size
);
6198 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6199 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6201 perf_output_put(&handle
, comm_event
->event_id
);
6202 __output_copy(&handle
, comm_event
->comm
,
6203 comm_event
->comm_size
);
6205 perf_event__output_id_sample(event
, &handle
, &sample
);
6207 perf_output_end(&handle
);
6209 comm_event
->event_id
.header
.size
= size
;
6212 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6214 char comm
[TASK_COMM_LEN
];
6217 memset(comm
, 0, sizeof(comm
));
6218 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6219 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6221 comm_event
->comm
= comm
;
6222 comm_event
->comm_size
= size
;
6224 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6226 perf_event_aux(perf_event_comm_output
,
6231 void perf_event_comm(struct task_struct
*task
, bool exec
)
6233 struct perf_comm_event comm_event
;
6235 if (!atomic_read(&nr_comm_events
))
6238 comm_event
= (struct perf_comm_event
){
6244 .type
= PERF_RECORD_COMM
,
6245 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6253 perf_event_comm_event(&comm_event
);
6260 struct perf_mmap_event
{
6261 struct vm_area_struct
*vma
;
6263 const char *file_name
;
6271 struct perf_event_header header
;
6281 static int perf_event_mmap_match(struct perf_event
*event
,
6284 struct perf_mmap_event
*mmap_event
= data
;
6285 struct vm_area_struct
*vma
= mmap_event
->vma
;
6286 int executable
= vma
->vm_flags
& VM_EXEC
;
6288 return (!executable
&& event
->attr
.mmap_data
) ||
6289 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6292 static void perf_event_mmap_output(struct perf_event
*event
,
6295 struct perf_mmap_event
*mmap_event
= data
;
6296 struct perf_output_handle handle
;
6297 struct perf_sample_data sample
;
6298 int size
= mmap_event
->event_id
.header
.size
;
6301 if (!perf_event_mmap_match(event
, data
))
6304 if (event
->attr
.mmap2
) {
6305 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6306 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6307 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6308 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6309 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6310 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6311 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6314 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6315 ret
= perf_output_begin(&handle
, event
,
6316 mmap_event
->event_id
.header
.size
);
6320 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6321 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6323 perf_output_put(&handle
, mmap_event
->event_id
);
6325 if (event
->attr
.mmap2
) {
6326 perf_output_put(&handle
, mmap_event
->maj
);
6327 perf_output_put(&handle
, mmap_event
->min
);
6328 perf_output_put(&handle
, mmap_event
->ino
);
6329 perf_output_put(&handle
, mmap_event
->ino_generation
);
6330 perf_output_put(&handle
, mmap_event
->prot
);
6331 perf_output_put(&handle
, mmap_event
->flags
);
6334 __output_copy(&handle
, mmap_event
->file_name
,
6335 mmap_event
->file_size
);
6337 perf_event__output_id_sample(event
, &handle
, &sample
);
6339 perf_output_end(&handle
);
6341 mmap_event
->event_id
.header
.size
= size
;
6344 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6346 struct vm_area_struct
*vma
= mmap_event
->vma
;
6347 struct file
*file
= vma
->vm_file
;
6348 int maj
= 0, min
= 0;
6349 u64 ino
= 0, gen
= 0;
6350 u32 prot
= 0, flags
= 0;
6357 struct inode
*inode
;
6360 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6366 * d_path() works from the end of the rb backwards, so we
6367 * need to add enough zero bytes after the string to handle
6368 * the 64bit alignment we do later.
6370 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6375 inode
= file_inode(vma
->vm_file
);
6376 dev
= inode
->i_sb
->s_dev
;
6378 gen
= inode
->i_generation
;
6382 if (vma
->vm_flags
& VM_READ
)
6384 if (vma
->vm_flags
& VM_WRITE
)
6386 if (vma
->vm_flags
& VM_EXEC
)
6389 if (vma
->vm_flags
& VM_MAYSHARE
)
6392 flags
= MAP_PRIVATE
;
6394 if (vma
->vm_flags
& VM_DENYWRITE
)
6395 flags
|= MAP_DENYWRITE
;
6396 if (vma
->vm_flags
& VM_MAYEXEC
)
6397 flags
|= MAP_EXECUTABLE
;
6398 if (vma
->vm_flags
& VM_LOCKED
)
6399 flags
|= MAP_LOCKED
;
6400 if (vma
->vm_flags
& VM_HUGETLB
)
6401 flags
|= MAP_HUGETLB
;
6405 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6406 name
= (char *) vma
->vm_ops
->name(vma
);
6411 name
= (char *)arch_vma_name(vma
);
6415 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6416 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6420 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6421 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6431 strlcpy(tmp
, name
, sizeof(tmp
));
6435 * Since our buffer works in 8 byte units we need to align our string
6436 * size to a multiple of 8. However, we must guarantee the tail end is
6437 * zero'd out to avoid leaking random bits to userspace.
6439 size
= strlen(name
)+1;
6440 while (!IS_ALIGNED(size
, sizeof(u64
)))
6441 name
[size
++] = '\0';
6443 mmap_event
->file_name
= name
;
6444 mmap_event
->file_size
= size
;
6445 mmap_event
->maj
= maj
;
6446 mmap_event
->min
= min
;
6447 mmap_event
->ino
= ino
;
6448 mmap_event
->ino_generation
= gen
;
6449 mmap_event
->prot
= prot
;
6450 mmap_event
->flags
= flags
;
6452 if (!(vma
->vm_flags
& VM_EXEC
))
6453 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6455 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6457 perf_event_aux(perf_event_mmap_output
,
6465 * Whether this @filter depends on a dynamic object which is not loaded
6466 * yet or its load addresses are not known.
6468 static bool perf_addr_filter_needs_mmap(struct perf_addr_filter
*filter
)
6470 return filter
->filter
&& filter
->inode
;
6474 * Check whether inode and address range match filter criteria.
6476 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
6477 struct file
*file
, unsigned long offset
,
6480 if (filter
->inode
!= file
->f_inode
)
6483 if (filter
->offset
> offset
+ size
)
6486 if (filter
->offset
+ filter
->size
< offset
)
6492 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
6494 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6495 struct vm_area_struct
*vma
= data
;
6496 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
6497 struct file
*file
= vma
->vm_file
;
6498 struct perf_addr_filter
*filter
;
6499 unsigned int restart
= 0, count
= 0;
6501 if (!has_addr_filter(event
))
6507 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6508 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6509 if (perf_addr_filter_match(filter
, file
, off
,
6510 vma
->vm_end
- vma
->vm_start
)) {
6511 event
->addr_filters_offs
[count
] = vma
->vm_start
;
6519 event
->addr_filters_gen
++;
6520 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6523 perf_event_restart(event
);
6527 * Adjust all task's events' filters to the new vma
6529 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
6531 struct perf_event_context
*ctx
;
6535 for_each_task_context_nr(ctxn
) {
6536 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6540 perf_event_aux_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
6545 void perf_event_mmap(struct vm_area_struct
*vma
)
6547 struct perf_mmap_event mmap_event
;
6549 if (!atomic_read(&nr_mmap_events
))
6552 mmap_event
= (struct perf_mmap_event
){
6558 .type
= PERF_RECORD_MMAP
,
6559 .misc
= PERF_RECORD_MISC_USER
,
6564 .start
= vma
->vm_start
,
6565 .len
= vma
->vm_end
- vma
->vm_start
,
6566 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6568 /* .maj (attr_mmap2 only) */
6569 /* .min (attr_mmap2 only) */
6570 /* .ino (attr_mmap2 only) */
6571 /* .ino_generation (attr_mmap2 only) */
6572 /* .prot (attr_mmap2 only) */
6573 /* .flags (attr_mmap2 only) */
6576 perf_addr_filters_adjust(vma
);
6577 perf_event_mmap_event(&mmap_event
);
6580 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6581 unsigned long size
, u64 flags
)
6583 struct perf_output_handle handle
;
6584 struct perf_sample_data sample
;
6585 struct perf_aux_event
{
6586 struct perf_event_header header
;
6592 .type
= PERF_RECORD_AUX
,
6594 .size
= sizeof(rec
),
6602 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6603 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6608 perf_output_put(&handle
, rec
);
6609 perf_event__output_id_sample(event
, &handle
, &sample
);
6611 perf_output_end(&handle
);
6615 * Lost/dropped samples logging
6617 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6619 struct perf_output_handle handle
;
6620 struct perf_sample_data sample
;
6624 struct perf_event_header header
;
6626 } lost_samples_event
= {
6628 .type
= PERF_RECORD_LOST_SAMPLES
,
6630 .size
= sizeof(lost_samples_event
),
6635 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6637 ret
= perf_output_begin(&handle
, event
,
6638 lost_samples_event
.header
.size
);
6642 perf_output_put(&handle
, lost_samples_event
);
6643 perf_event__output_id_sample(event
, &handle
, &sample
);
6644 perf_output_end(&handle
);
6648 * context_switch tracking
6651 struct perf_switch_event
{
6652 struct task_struct
*task
;
6653 struct task_struct
*next_prev
;
6656 struct perf_event_header header
;
6662 static int perf_event_switch_match(struct perf_event
*event
)
6664 return event
->attr
.context_switch
;
6667 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6669 struct perf_switch_event
*se
= data
;
6670 struct perf_output_handle handle
;
6671 struct perf_sample_data sample
;
6674 if (!perf_event_switch_match(event
))
6677 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6678 if (event
->ctx
->task
) {
6679 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6680 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6682 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6683 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6684 se
->event_id
.next_prev_pid
=
6685 perf_event_pid(event
, se
->next_prev
);
6686 se
->event_id
.next_prev_tid
=
6687 perf_event_tid(event
, se
->next_prev
);
6690 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6692 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6696 if (event
->ctx
->task
)
6697 perf_output_put(&handle
, se
->event_id
.header
);
6699 perf_output_put(&handle
, se
->event_id
);
6701 perf_event__output_id_sample(event
, &handle
, &sample
);
6703 perf_output_end(&handle
);
6706 static void perf_event_switch(struct task_struct
*task
,
6707 struct task_struct
*next_prev
, bool sched_in
)
6709 struct perf_switch_event switch_event
;
6711 /* N.B. caller checks nr_switch_events != 0 */
6713 switch_event
= (struct perf_switch_event
){
6715 .next_prev
= next_prev
,
6719 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6722 /* .next_prev_pid */
6723 /* .next_prev_tid */
6727 perf_event_aux(perf_event_switch_output
,
6733 * IRQ throttle logging
6736 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6738 struct perf_output_handle handle
;
6739 struct perf_sample_data sample
;
6743 struct perf_event_header header
;
6747 } throttle_event
= {
6749 .type
= PERF_RECORD_THROTTLE
,
6751 .size
= sizeof(throttle_event
),
6753 .time
= perf_event_clock(event
),
6754 .id
= primary_event_id(event
),
6755 .stream_id
= event
->id
,
6759 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6761 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6763 ret
= perf_output_begin(&handle
, event
,
6764 throttle_event
.header
.size
);
6768 perf_output_put(&handle
, throttle_event
);
6769 perf_event__output_id_sample(event
, &handle
, &sample
);
6770 perf_output_end(&handle
);
6773 static void perf_log_itrace_start(struct perf_event
*event
)
6775 struct perf_output_handle handle
;
6776 struct perf_sample_data sample
;
6777 struct perf_aux_event
{
6778 struct perf_event_header header
;
6785 event
= event
->parent
;
6787 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6788 event
->hw
.itrace_started
)
6791 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6792 rec
.header
.misc
= 0;
6793 rec
.header
.size
= sizeof(rec
);
6794 rec
.pid
= perf_event_pid(event
, current
);
6795 rec
.tid
= perf_event_tid(event
, current
);
6797 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6798 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6803 perf_output_put(&handle
, rec
);
6804 perf_event__output_id_sample(event
, &handle
, &sample
);
6806 perf_output_end(&handle
);
6810 * Generic event overflow handling, sampling.
6813 static int __perf_event_overflow(struct perf_event
*event
,
6814 int throttle
, struct perf_sample_data
*data
,
6815 struct pt_regs
*regs
)
6817 int events
= atomic_read(&event
->event_limit
);
6818 struct hw_perf_event
*hwc
= &event
->hw
;
6823 * Non-sampling counters might still use the PMI to fold short
6824 * hardware counters, ignore those.
6826 if (unlikely(!is_sampling_event(event
)))
6829 seq
= __this_cpu_read(perf_throttled_seq
);
6830 if (seq
!= hwc
->interrupts_seq
) {
6831 hwc
->interrupts_seq
= seq
;
6832 hwc
->interrupts
= 1;
6835 if (unlikely(throttle
6836 && hwc
->interrupts
>= max_samples_per_tick
)) {
6837 __this_cpu_inc(perf_throttled_count
);
6838 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
6839 hwc
->interrupts
= MAX_INTERRUPTS
;
6840 perf_log_throttle(event
, 0);
6845 if (event
->attr
.freq
) {
6846 u64 now
= perf_clock();
6847 s64 delta
= now
- hwc
->freq_time_stamp
;
6849 hwc
->freq_time_stamp
= now
;
6851 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6852 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6856 * XXX event_limit might not quite work as expected on inherited
6860 event
->pending_kill
= POLL_IN
;
6861 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6863 event
->pending_kill
= POLL_HUP
;
6864 event
->pending_disable
= 1;
6865 irq_work_queue(&event
->pending
);
6868 event
->overflow_handler(event
, data
, regs
);
6870 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6871 event
->pending_wakeup
= 1;
6872 irq_work_queue(&event
->pending
);
6878 int perf_event_overflow(struct perf_event
*event
,
6879 struct perf_sample_data
*data
,
6880 struct pt_regs
*regs
)
6882 return __perf_event_overflow(event
, 1, data
, regs
);
6886 * Generic software event infrastructure
6889 struct swevent_htable
{
6890 struct swevent_hlist
*swevent_hlist
;
6891 struct mutex hlist_mutex
;
6894 /* Recursion avoidance in each contexts */
6895 int recursion
[PERF_NR_CONTEXTS
];
6898 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6901 * We directly increment event->count and keep a second value in
6902 * event->hw.period_left to count intervals. This period event
6903 * is kept in the range [-sample_period, 0] so that we can use the
6907 u64
perf_swevent_set_period(struct perf_event
*event
)
6909 struct hw_perf_event
*hwc
= &event
->hw
;
6910 u64 period
= hwc
->last_period
;
6914 hwc
->last_period
= hwc
->sample_period
;
6917 old
= val
= local64_read(&hwc
->period_left
);
6921 nr
= div64_u64(period
+ val
, period
);
6922 offset
= nr
* period
;
6924 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6930 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6931 struct perf_sample_data
*data
,
6932 struct pt_regs
*regs
)
6934 struct hw_perf_event
*hwc
= &event
->hw
;
6938 overflow
= perf_swevent_set_period(event
);
6940 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6943 for (; overflow
; overflow
--) {
6944 if (__perf_event_overflow(event
, throttle
,
6947 * We inhibit the overflow from happening when
6948 * hwc->interrupts == MAX_INTERRUPTS.
6956 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6957 struct perf_sample_data
*data
,
6958 struct pt_regs
*regs
)
6960 struct hw_perf_event
*hwc
= &event
->hw
;
6962 local64_add(nr
, &event
->count
);
6967 if (!is_sampling_event(event
))
6970 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6972 return perf_swevent_overflow(event
, 1, data
, regs
);
6974 data
->period
= event
->hw
.last_period
;
6976 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6977 return perf_swevent_overflow(event
, 1, data
, regs
);
6979 if (local64_add_negative(nr
, &hwc
->period_left
))
6982 perf_swevent_overflow(event
, 0, data
, regs
);
6985 static int perf_exclude_event(struct perf_event
*event
,
6986 struct pt_regs
*regs
)
6988 if (event
->hw
.state
& PERF_HES_STOPPED
)
6992 if (event
->attr
.exclude_user
&& user_mode(regs
))
6995 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7002 static int perf_swevent_match(struct perf_event
*event
,
7003 enum perf_type_id type
,
7005 struct perf_sample_data
*data
,
7006 struct pt_regs
*regs
)
7008 if (event
->attr
.type
!= type
)
7011 if (event
->attr
.config
!= event_id
)
7014 if (perf_exclude_event(event
, regs
))
7020 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7022 u64 val
= event_id
| (type
<< 32);
7024 return hash_64(val
, SWEVENT_HLIST_BITS
);
7027 static inline struct hlist_head
*
7028 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7030 u64 hash
= swevent_hash(type
, event_id
);
7032 return &hlist
->heads
[hash
];
7035 /* For the read side: events when they trigger */
7036 static inline struct hlist_head
*
7037 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7039 struct swevent_hlist
*hlist
;
7041 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7045 return __find_swevent_head(hlist
, type
, event_id
);
7048 /* For the event head insertion and removal in the hlist */
7049 static inline struct hlist_head
*
7050 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7052 struct swevent_hlist
*hlist
;
7053 u32 event_id
= event
->attr
.config
;
7054 u64 type
= event
->attr
.type
;
7057 * Event scheduling is always serialized against hlist allocation
7058 * and release. Which makes the protected version suitable here.
7059 * The context lock guarantees that.
7061 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7062 lockdep_is_held(&event
->ctx
->lock
));
7066 return __find_swevent_head(hlist
, type
, event_id
);
7069 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7071 struct perf_sample_data
*data
,
7072 struct pt_regs
*regs
)
7074 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7075 struct perf_event
*event
;
7076 struct hlist_head
*head
;
7079 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7083 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7084 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7085 perf_swevent_event(event
, nr
, data
, regs
);
7091 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7093 int perf_swevent_get_recursion_context(void)
7095 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7097 return get_recursion_context(swhash
->recursion
);
7099 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7101 void perf_swevent_put_recursion_context(int rctx
)
7103 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7105 put_recursion_context(swhash
->recursion
, rctx
);
7108 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7110 struct perf_sample_data data
;
7112 if (WARN_ON_ONCE(!regs
))
7115 perf_sample_data_init(&data
, addr
, 0);
7116 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7119 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7123 preempt_disable_notrace();
7124 rctx
= perf_swevent_get_recursion_context();
7125 if (unlikely(rctx
< 0))
7128 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7130 perf_swevent_put_recursion_context(rctx
);
7132 preempt_enable_notrace();
7135 static void perf_swevent_read(struct perf_event
*event
)
7139 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7141 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7142 struct hw_perf_event
*hwc
= &event
->hw
;
7143 struct hlist_head
*head
;
7145 if (is_sampling_event(event
)) {
7146 hwc
->last_period
= hwc
->sample_period
;
7147 perf_swevent_set_period(event
);
7150 hwc
->state
= !(flags
& PERF_EF_START
);
7152 head
= find_swevent_head(swhash
, event
);
7153 if (WARN_ON_ONCE(!head
))
7156 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7157 perf_event_update_userpage(event
);
7162 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7164 hlist_del_rcu(&event
->hlist_entry
);
7167 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7169 event
->hw
.state
= 0;
7172 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7174 event
->hw
.state
= PERF_HES_STOPPED
;
7177 /* Deref the hlist from the update side */
7178 static inline struct swevent_hlist
*
7179 swevent_hlist_deref(struct swevent_htable
*swhash
)
7181 return rcu_dereference_protected(swhash
->swevent_hlist
,
7182 lockdep_is_held(&swhash
->hlist_mutex
));
7185 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7187 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7192 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7193 kfree_rcu(hlist
, rcu_head
);
7196 static void swevent_hlist_put_cpu(int cpu
)
7198 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7200 mutex_lock(&swhash
->hlist_mutex
);
7202 if (!--swhash
->hlist_refcount
)
7203 swevent_hlist_release(swhash
);
7205 mutex_unlock(&swhash
->hlist_mutex
);
7208 static void swevent_hlist_put(void)
7212 for_each_possible_cpu(cpu
)
7213 swevent_hlist_put_cpu(cpu
);
7216 static int swevent_hlist_get_cpu(int cpu
)
7218 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7221 mutex_lock(&swhash
->hlist_mutex
);
7222 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
7223 struct swevent_hlist
*hlist
;
7225 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7230 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7232 swhash
->hlist_refcount
++;
7234 mutex_unlock(&swhash
->hlist_mutex
);
7239 static int swevent_hlist_get(void)
7241 int err
, cpu
, failed_cpu
;
7244 for_each_possible_cpu(cpu
) {
7245 err
= swevent_hlist_get_cpu(cpu
);
7255 for_each_possible_cpu(cpu
) {
7256 if (cpu
== failed_cpu
)
7258 swevent_hlist_put_cpu(cpu
);
7265 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7267 static void sw_perf_event_destroy(struct perf_event
*event
)
7269 u64 event_id
= event
->attr
.config
;
7271 WARN_ON(event
->parent
);
7273 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7274 swevent_hlist_put();
7277 static int perf_swevent_init(struct perf_event
*event
)
7279 u64 event_id
= event
->attr
.config
;
7281 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7285 * no branch sampling for software events
7287 if (has_branch_stack(event
))
7291 case PERF_COUNT_SW_CPU_CLOCK
:
7292 case PERF_COUNT_SW_TASK_CLOCK
:
7299 if (event_id
>= PERF_COUNT_SW_MAX
)
7302 if (!event
->parent
) {
7305 err
= swevent_hlist_get();
7309 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7310 event
->destroy
= sw_perf_event_destroy
;
7316 static struct pmu perf_swevent
= {
7317 .task_ctx_nr
= perf_sw_context
,
7319 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7321 .event_init
= perf_swevent_init
,
7322 .add
= perf_swevent_add
,
7323 .del
= perf_swevent_del
,
7324 .start
= perf_swevent_start
,
7325 .stop
= perf_swevent_stop
,
7326 .read
= perf_swevent_read
,
7329 #ifdef CONFIG_EVENT_TRACING
7331 static int perf_tp_filter_match(struct perf_event
*event
,
7332 struct perf_sample_data
*data
)
7334 void *record
= data
->raw
->data
;
7336 /* only top level events have filters set */
7338 event
= event
->parent
;
7340 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7345 static int perf_tp_event_match(struct perf_event
*event
,
7346 struct perf_sample_data
*data
,
7347 struct pt_regs
*regs
)
7349 if (event
->hw
.state
& PERF_HES_STOPPED
)
7352 * All tracepoints are from kernel-space.
7354 if (event
->attr
.exclude_kernel
)
7357 if (!perf_tp_filter_match(event
, data
))
7363 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7364 struct trace_event_call
*call
, u64 count
,
7365 struct pt_regs
*regs
, struct hlist_head
*head
,
7366 struct task_struct
*task
)
7368 struct bpf_prog
*prog
= call
->prog
;
7371 *(struct pt_regs
**)raw_data
= regs
;
7372 if (!trace_call_bpf(prog
, raw_data
) || hlist_empty(head
)) {
7373 perf_swevent_put_recursion_context(rctx
);
7377 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7380 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7382 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7383 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7384 struct task_struct
*task
)
7386 struct perf_sample_data data
;
7387 struct perf_event
*event
;
7389 struct perf_raw_record raw
= {
7394 perf_sample_data_init(&data
, 0, 0);
7397 perf_trace_buf_update(record
, event_type
);
7399 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7400 if (perf_tp_event_match(event
, &data
, regs
))
7401 perf_swevent_event(event
, count
, &data
, regs
);
7405 * If we got specified a target task, also iterate its context and
7406 * deliver this event there too.
7408 if (task
&& task
!= current
) {
7409 struct perf_event_context
*ctx
;
7410 struct trace_entry
*entry
= record
;
7413 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7417 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7418 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7420 if (event
->attr
.config
!= entry
->type
)
7422 if (perf_tp_event_match(event
, &data
, regs
))
7423 perf_swevent_event(event
, count
, &data
, regs
);
7429 perf_swevent_put_recursion_context(rctx
);
7431 EXPORT_SYMBOL_GPL(perf_tp_event
);
7433 static void tp_perf_event_destroy(struct perf_event
*event
)
7435 perf_trace_destroy(event
);
7438 static int perf_tp_event_init(struct perf_event
*event
)
7442 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7446 * no branch sampling for tracepoint events
7448 if (has_branch_stack(event
))
7451 err
= perf_trace_init(event
);
7455 event
->destroy
= tp_perf_event_destroy
;
7460 static struct pmu perf_tracepoint
= {
7461 .task_ctx_nr
= perf_sw_context
,
7463 .event_init
= perf_tp_event_init
,
7464 .add
= perf_trace_add
,
7465 .del
= perf_trace_del
,
7466 .start
= perf_swevent_start
,
7467 .stop
= perf_swevent_stop
,
7468 .read
= perf_swevent_read
,
7471 static inline void perf_tp_register(void)
7473 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7476 static void perf_event_free_filter(struct perf_event
*event
)
7478 ftrace_profile_free_filter(event
);
7481 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7483 bool is_kprobe
, is_tracepoint
;
7484 struct bpf_prog
*prog
;
7486 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7489 if (event
->tp_event
->prog
)
7492 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
7493 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
7494 if (!is_kprobe
&& !is_tracepoint
)
7495 /* bpf programs can only be attached to u/kprobe or tracepoint */
7498 prog
= bpf_prog_get(prog_fd
);
7500 return PTR_ERR(prog
);
7502 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
7503 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
7504 /* valid fd, but invalid bpf program type */
7509 if (is_tracepoint
) {
7510 int off
= trace_event_get_offsets(event
->tp_event
);
7512 if (prog
->aux
->max_ctx_offset
> off
) {
7517 event
->tp_event
->prog
= prog
;
7522 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7524 struct bpf_prog
*prog
;
7526 if (!event
->tp_event
)
7529 prog
= event
->tp_event
->prog
;
7531 event
->tp_event
->prog
= NULL
;
7538 static inline void perf_tp_register(void)
7542 static void perf_event_free_filter(struct perf_event
*event
)
7546 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7551 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7554 #endif /* CONFIG_EVENT_TRACING */
7556 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7557 void perf_bp_event(struct perf_event
*bp
, void *data
)
7559 struct perf_sample_data sample
;
7560 struct pt_regs
*regs
= data
;
7562 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7564 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7565 perf_swevent_event(bp
, 1, &sample
, regs
);
7570 * Allocate a new address filter
7572 static struct perf_addr_filter
*
7573 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
7575 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
7576 struct perf_addr_filter
*filter
;
7578 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
7582 INIT_LIST_HEAD(&filter
->entry
);
7583 list_add_tail(&filter
->entry
, filters
);
7588 static void free_filters_list(struct list_head
*filters
)
7590 struct perf_addr_filter
*filter
, *iter
;
7592 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
7594 iput(filter
->inode
);
7595 list_del(&filter
->entry
);
7601 * Free existing address filters and optionally install new ones
7603 static void perf_addr_filters_splice(struct perf_event
*event
,
7604 struct list_head
*head
)
7606 unsigned long flags
;
7609 if (!has_addr_filter(event
))
7612 /* don't bother with children, they don't have their own filters */
7616 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
7618 list_splice_init(&event
->addr_filters
.list
, &list
);
7620 list_splice(head
, &event
->addr_filters
.list
);
7622 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
7624 free_filters_list(&list
);
7628 * Scan through mm's vmas and see if one of them matches the
7629 * @filter; if so, adjust filter's address range.
7630 * Called with mm::mmap_sem down for reading.
7632 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
7633 struct mm_struct
*mm
)
7635 struct vm_area_struct
*vma
;
7637 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
7638 struct file
*file
= vma
->vm_file
;
7639 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
7640 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
7645 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
7648 return vma
->vm_start
;
7655 * Update event's address range filters based on the
7656 * task's existing mappings, if any.
7658 static void perf_event_addr_filters_apply(struct perf_event
*event
)
7660 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7661 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
7662 struct perf_addr_filter
*filter
;
7663 struct mm_struct
*mm
= NULL
;
7664 unsigned int count
= 0;
7665 unsigned long flags
;
7668 * We may observe TASK_TOMBSTONE, which means that the event tear-down
7669 * will stop on the parent's child_mutex that our caller is also holding
7671 if (task
== TASK_TOMBSTONE
)
7674 mm
= get_task_mm(event
->ctx
->task
);
7678 down_read(&mm
->mmap_sem
);
7680 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7681 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7682 event
->addr_filters_offs
[count
] = 0;
7684 if (perf_addr_filter_needs_mmap(filter
))
7685 event
->addr_filters_offs
[count
] =
7686 perf_addr_filter_apply(filter
, mm
);
7691 event
->addr_filters_gen
++;
7692 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7694 up_read(&mm
->mmap_sem
);
7699 perf_event_restart(event
);
7703 * Address range filtering: limiting the data to certain
7704 * instruction address ranges. Filters are ioctl()ed to us from
7705 * userspace as ascii strings.
7707 * Filter string format:
7710 * where ACTION is one of the
7711 * * "filter": limit the trace to this region
7712 * * "start": start tracing from this address
7713 * * "stop": stop tracing at this address/region;
7715 * * for kernel addresses: <start address>[/<size>]
7716 * * for object files: <start address>[/<size>]@</path/to/object/file>
7718 * if <size> is not specified, the range is treated as a single address.
7731 IF_STATE_ACTION
= 0,
7736 static const match_table_t if_tokens
= {
7737 { IF_ACT_FILTER
, "filter" },
7738 { IF_ACT_START
, "start" },
7739 { IF_ACT_STOP
, "stop" },
7740 { IF_SRC_FILE
, "%u/%u@%s" },
7741 { IF_SRC_KERNEL
, "%u/%u" },
7742 { IF_SRC_FILEADDR
, "%u@%s" },
7743 { IF_SRC_KERNELADDR
, "%u" },
7747 * Address filter string parser
7750 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
7751 struct list_head
*filters
)
7753 struct perf_addr_filter
*filter
= NULL
;
7754 char *start
, *orig
, *filename
= NULL
;
7756 substring_t args
[MAX_OPT_ARGS
];
7757 int state
= IF_STATE_ACTION
, token
;
7758 unsigned int kernel
= 0;
7761 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
7765 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
7771 /* filter definition begins */
7772 if (state
== IF_STATE_ACTION
) {
7773 filter
= perf_addr_filter_new(event
, filters
);
7778 token
= match_token(start
, if_tokens
, args
);
7785 if (state
!= IF_STATE_ACTION
)
7788 state
= IF_STATE_SOURCE
;
7791 case IF_SRC_KERNELADDR
:
7795 case IF_SRC_FILEADDR
:
7797 if (state
!= IF_STATE_SOURCE
)
7800 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
7804 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
7808 if (filter
->range
) {
7810 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
7815 if (token
== IF_SRC_FILE
) {
7816 filename
= match_strdup(&args
[2]);
7823 state
= IF_STATE_END
;
7831 * Filter definition is fully parsed, validate and install it.
7832 * Make sure that it doesn't contradict itself or the event's
7835 if (state
== IF_STATE_END
) {
7836 if (kernel
&& event
->attr
.exclude_kernel
)
7843 /* look up the path and grab its inode */
7844 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
7846 goto fail_free_name
;
7848 filter
->inode
= igrab(d_inode(path
.dentry
));
7854 if (!filter
->inode
||
7855 !S_ISREG(filter
->inode
->i_mode
))
7856 /* free_filters_list() will iput() */
7860 /* ready to consume more filters */
7861 state
= IF_STATE_ACTION
;
7866 if (state
!= IF_STATE_ACTION
)
7876 free_filters_list(filters
);
7883 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
7889 * Since this is called in perf_ioctl() path, we're already holding
7892 lockdep_assert_held(&event
->ctx
->mutex
);
7894 if (WARN_ON_ONCE(event
->parent
))
7898 * For now, we only support filtering in per-task events; doing so
7899 * for CPU-wide events requires additional context switching trickery,
7900 * since same object code will be mapped at different virtual
7901 * addresses in different processes.
7903 if (!event
->ctx
->task
)
7906 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
7910 ret
= event
->pmu
->addr_filters_validate(&filters
);
7912 free_filters_list(&filters
);
7916 /* remove existing filters, if any */
7917 perf_addr_filters_splice(event
, &filters
);
7919 /* install new filters */
7920 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
7925 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7930 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
7931 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
7932 !has_addr_filter(event
))
7935 filter_str
= strndup_user(arg
, PAGE_SIZE
);
7936 if (IS_ERR(filter_str
))
7937 return PTR_ERR(filter_str
);
7939 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
7940 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
7941 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
7943 else if (has_addr_filter(event
))
7944 ret
= perf_event_set_addr_filter(event
, filter_str
);
7951 * hrtimer based swevent callback
7954 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7956 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7957 struct perf_sample_data data
;
7958 struct pt_regs
*regs
;
7959 struct perf_event
*event
;
7962 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7964 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7965 return HRTIMER_NORESTART
;
7967 event
->pmu
->read(event
);
7969 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7970 regs
= get_irq_regs();
7972 if (regs
&& !perf_exclude_event(event
, regs
)) {
7973 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7974 if (__perf_event_overflow(event
, 1, &data
, regs
))
7975 ret
= HRTIMER_NORESTART
;
7978 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7979 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7984 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7986 struct hw_perf_event
*hwc
= &event
->hw
;
7989 if (!is_sampling_event(event
))
7992 period
= local64_read(&hwc
->period_left
);
7997 local64_set(&hwc
->period_left
, 0);
7999 period
= max_t(u64
, 10000, hwc
->sample_period
);
8001 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8002 HRTIMER_MODE_REL_PINNED
);
8005 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8007 struct hw_perf_event
*hwc
= &event
->hw
;
8009 if (is_sampling_event(event
)) {
8010 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8011 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8013 hrtimer_cancel(&hwc
->hrtimer
);
8017 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8019 struct hw_perf_event
*hwc
= &event
->hw
;
8021 if (!is_sampling_event(event
))
8024 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8025 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8028 * Since hrtimers have a fixed rate, we can do a static freq->period
8029 * mapping and avoid the whole period adjust feedback stuff.
8031 if (event
->attr
.freq
) {
8032 long freq
= event
->attr
.sample_freq
;
8034 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8035 hwc
->sample_period
= event
->attr
.sample_period
;
8036 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8037 hwc
->last_period
= hwc
->sample_period
;
8038 event
->attr
.freq
= 0;
8043 * Software event: cpu wall time clock
8046 static void cpu_clock_event_update(struct perf_event
*event
)
8051 now
= local_clock();
8052 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8053 local64_add(now
- prev
, &event
->count
);
8056 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8058 local64_set(&event
->hw
.prev_count
, local_clock());
8059 perf_swevent_start_hrtimer(event
);
8062 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8064 perf_swevent_cancel_hrtimer(event
);
8065 cpu_clock_event_update(event
);
8068 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8070 if (flags
& PERF_EF_START
)
8071 cpu_clock_event_start(event
, flags
);
8072 perf_event_update_userpage(event
);
8077 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8079 cpu_clock_event_stop(event
, flags
);
8082 static void cpu_clock_event_read(struct perf_event
*event
)
8084 cpu_clock_event_update(event
);
8087 static int cpu_clock_event_init(struct perf_event
*event
)
8089 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8092 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8096 * no branch sampling for software events
8098 if (has_branch_stack(event
))
8101 perf_swevent_init_hrtimer(event
);
8106 static struct pmu perf_cpu_clock
= {
8107 .task_ctx_nr
= perf_sw_context
,
8109 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8111 .event_init
= cpu_clock_event_init
,
8112 .add
= cpu_clock_event_add
,
8113 .del
= cpu_clock_event_del
,
8114 .start
= cpu_clock_event_start
,
8115 .stop
= cpu_clock_event_stop
,
8116 .read
= cpu_clock_event_read
,
8120 * Software event: task time clock
8123 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8128 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8130 local64_add(delta
, &event
->count
);
8133 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8135 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8136 perf_swevent_start_hrtimer(event
);
8139 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8141 perf_swevent_cancel_hrtimer(event
);
8142 task_clock_event_update(event
, event
->ctx
->time
);
8145 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8147 if (flags
& PERF_EF_START
)
8148 task_clock_event_start(event
, flags
);
8149 perf_event_update_userpage(event
);
8154 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8156 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8159 static void task_clock_event_read(struct perf_event
*event
)
8161 u64 now
= perf_clock();
8162 u64 delta
= now
- event
->ctx
->timestamp
;
8163 u64 time
= event
->ctx
->time
+ delta
;
8165 task_clock_event_update(event
, time
);
8168 static int task_clock_event_init(struct perf_event
*event
)
8170 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8173 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8177 * no branch sampling for software events
8179 if (has_branch_stack(event
))
8182 perf_swevent_init_hrtimer(event
);
8187 static struct pmu perf_task_clock
= {
8188 .task_ctx_nr
= perf_sw_context
,
8190 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8192 .event_init
= task_clock_event_init
,
8193 .add
= task_clock_event_add
,
8194 .del
= task_clock_event_del
,
8195 .start
= task_clock_event_start
,
8196 .stop
= task_clock_event_stop
,
8197 .read
= task_clock_event_read
,
8200 static void perf_pmu_nop_void(struct pmu
*pmu
)
8204 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8208 static int perf_pmu_nop_int(struct pmu
*pmu
)
8213 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8215 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8217 __this_cpu_write(nop_txn_flags
, flags
);
8219 if (flags
& ~PERF_PMU_TXN_ADD
)
8222 perf_pmu_disable(pmu
);
8225 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8227 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8229 __this_cpu_write(nop_txn_flags
, 0);
8231 if (flags
& ~PERF_PMU_TXN_ADD
)
8234 perf_pmu_enable(pmu
);
8238 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8240 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8242 __this_cpu_write(nop_txn_flags
, 0);
8244 if (flags
& ~PERF_PMU_TXN_ADD
)
8247 perf_pmu_enable(pmu
);
8250 static int perf_event_idx_default(struct perf_event
*event
)
8256 * Ensures all contexts with the same task_ctx_nr have the same
8257 * pmu_cpu_context too.
8259 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8266 list_for_each_entry(pmu
, &pmus
, entry
) {
8267 if (pmu
->task_ctx_nr
== ctxn
)
8268 return pmu
->pmu_cpu_context
;
8274 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
8278 for_each_possible_cpu(cpu
) {
8279 struct perf_cpu_context
*cpuctx
;
8281 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8283 if (cpuctx
->unique_pmu
== old_pmu
)
8284 cpuctx
->unique_pmu
= pmu
;
8288 static void free_pmu_context(struct pmu
*pmu
)
8292 mutex_lock(&pmus_lock
);
8294 * Like a real lame refcount.
8296 list_for_each_entry(i
, &pmus
, entry
) {
8297 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
8298 update_pmu_context(i
, pmu
);
8303 free_percpu(pmu
->pmu_cpu_context
);
8305 mutex_unlock(&pmus_lock
);
8309 * Let userspace know that this PMU supports address range filtering:
8311 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8312 struct device_attribute
*attr
,
8315 struct pmu
*pmu
= dev_get_drvdata(dev
);
8317 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8319 DEVICE_ATTR_RO(nr_addr_filters
);
8321 static struct idr pmu_idr
;
8324 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8326 struct pmu
*pmu
= dev_get_drvdata(dev
);
8328 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8330 static DEVICE_ATTR_RO(type
);
8333 perf_event_mux_interval_ms_show(struct device
*dev
,
8334 struct device_attribute
*attr
,
8337 struct pmu
*pmu
= dev_get_drvdata(dev
);
8339 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8342 static DEFINE_MUTEX(mux_interval_mutex
);
8345 perf_event_mux_interval_ms_store(struct device
*dev
,
8346 struct device_attribute
*attr
,
8347 const char *buf
, size_t count
)
8349 struct pmu
*pmu
= dev_get_drvdata(dev
);
8350 int timer
, cpu
, ret
;
8352 ret
= kstrtoint(buf
, 0, &timer
);
8359 /* same value, noting to do */
8360 if (timer
== pmu
->hrtimer_interval_ms
)
8363 mutex_lock(&mux_interval_mutex
);
8364 pmu
->hrtimer_interval_ms
= timer
;
8366 /* update all cpuctx for this PMU */
8368 for_each_online_cpu(cpu
) {
8369 struct perf_cpu_context
*cpuctx
;
8370 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8371 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
8373 cpu_function_call(cpu
,
8374 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
8377 mutex_unlock(&mux_interval_mutex
);
8381 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
8383 static struct attribute
*pmu_dev_attrs
[] = {
8384 &dev_attr_type
.attr
,
8385 &dev_attr_perf_event_mux_interval_ms
.attr
,
8388 ATTRIBUTE_GROUPS(pmu_dev
);
8390 static int pmu_bus_running
;
8391 static struct bus_type pmu_bus
= {
8392 .name
= "event_source",
8393 .dev_groups
= pmu_dev_groups
,
8396 static void pmu_dev_release(struct device
*dev
)
8401 static int pmu_dev_alloc(struct pmu
*pmu
)
8405 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
8409 pmu
->dev
->groups
= pmu
->attr_groups
;
8410 device_initialize(pmu
->dev
);
8411 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
8415 dev_set_drvdata(pmu
->dev
, pmu
);
8416 pmu
->dev
->bus
= &pmu_bus
;
8417 pmu
->dev
->release
= pmu_dev_release
;
8418 ret
= device_add(pmu
->dev
);
8422 /* For PMUs with address filters, throw in an extra attribute: */
8423 if (pmu
->nr_addr_filters
)
8424 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
8433 device_del(pmu
->dev
);
8436 put_device(pmu
->dev
);
8440 static struct lock_class_key cpuctx_mutex
;
8441 static struct lock_class_key cpuctx_lock
;
8443 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
8447 mutex_lock(&pmus_lock
);
8449 pmu
->pmu_disable_count
= alloc_percpu(int);
8450 if (!pmu
->pmu_disable_count
)
8459 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
8467 if (pmu_bus_running
) {
8468 ret
= pmu_dev_alloc(pmu
);
8474 if (pmu
->task_ctx_nr
== perf_hw_context
) {
8475 static int hw_context_taken
= 0;
8478 * Other than systems with heterogeneous CPUs, it never makes
8479 * sense for two PMUs to share perf_hw_context. PMUs which are
8480 * uncore must use perf_invalid_context.
8482 if (WARN_ON_ONCE(hw_context_taken
&&
8483 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
8484 pmu
->task_ctx_nr
= perf_invalid_context
;
8486 hw_context_taken
= 1;
8489 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
8490 if (pmu
->pmu_cpu_context
)
8491 goto got_cpu_context
;
8494 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
8495 if (!pmu
->pmu_cpu_context
)
8498 for_each_possible_cpu(cpu
) {
8499 struct perf_cpu_context
*cpuctx
;
8501 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8502 __perf_event_init_context(&cpuctx
->ctx
);
8503 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
8504 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
8505 cpuctx
->ctx
.pmu
= pmu
;
8507 __perf_mux_hrtimer_init(cpuctx
, cpu
);
8509 cpuctx
->unique_pmu
= pmu
;
8513 if (!pmu
->start_txn
) {
8514 if (pmu
->pmu_enable
) {
8516 * If we have pmu_enable/pmu_disable calls, install
8517 * transaction stubs that use that to try and batch
8518 * hardware accesses.
8520 pmu
->start_txn
= perf_pmu_start_txn
;
8521 pmu
->commit_txn
= perf_pmu_commit_txn
;
8522 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
8524 pmu
->start_txn
= perf_pmu_nop_txn
;
8525 pmu
->commit_txn
= perf_pmu_nop_int
;
8526 pmu
->cancel_txn
= perf_pmu_nop_void
;
8530 if (!pmu
->pmu_enable
) {
8531 pmu
->pmu_enable
= perf_pmu_nop_void
;
8532 pmu
->pmu_disable
= perf_pmu_nop_void
;
8535 if (!pmu
->event_idx
)
8536 pmu
->event_idx
= perf_event_idx_default
;
8538 list_add_rcu(&pmu
->entry
, &pmus
);
8539 atomic_set(&pmu
->exclusive_cnt
, 0);
8542 mutex_unlock(&pmus_lock
);
8547 device_del(pmu
->dev
);
8548 put_device(pmu
->dev
);
8551 if (pmu
->type
>= PERF_TYPE_MAX
)
8552 idr_remove(&pmu_idr
, pmu
->type
);
8555 free_percpu(pmu
->pmu_disable_count
);
8558 EXPORT_SYMBOL_GPL(perf_pmu_register
);
8560 void perf_pmu_unregister(struct pmu
*pmu
)
8562 mutex_lock(&pmus_lock
);
8563 list_del_rcu(&pmu
->entry
);
8564 mutex_unlock(&pmus_lock
);
8567 * We dereference the pmu list under both SRCU and regular RCU, so
8568 * synchronize against both of those.
8570 synchronize_srcu(&pmus_srcu
);
8573 free_percpu(pmu
->pmu_disable_count
);
8574 if (pmu
->type
>= PERF_TYPE_MAX
)
8575 idr_remove(&pmu_idr
, pmu
->type
);
8576 if (pmu
->nr_addr_filters
)
8577 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
8578 device_del(pmu
->dev
);
8579 put_device(pmu
->dev
);
8580 free_pmu_context(pmu
);
8582 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
8584 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
8586 struct perf_event_context
*ctx
= NULL
;
8589 if (!try_module_get(pmu
->module
))
8592 if (event
->group_leader
!= event
) {
8594 * This ctx->mutex can nest when we're called through
8595 * inheritance. See the perf_event_ctx_lock_nested() comment.
8597 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
8598 SINGLE_DEPTH_NESTING
);
8603 ret
= pmu
->event_init(event
);
8606 perf_event_ctx_unlock(event
->group_leader
, ctx
);
8609 module_put(pmu
->module
);
8614 static struct pmu
*perf_init_event(struct perf_event
*event
)
8616 struct pmu
*pmu
= NULL
;
8620 idx
= srcu_read_lock(&pmus_srcu
);
8623 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
8626 ret
= perf_try_init_event(pmu
, event
);
8632 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
8633 ret
= perf_try_init_event(pmu
, event
);
8637 if (ret
!= -ENOENT
) {
8642 pmu
= ERR_PTR(-ENOENT
);
8644 srcu_read_unlock(&pmus_srcu
, idx
);
8649 static void account_event_cpu(struct perf_event
*event
, int cpu
)
8654 if (is_cgroup_event(event
))
8655 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
8658 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
8659 static void account_freq_event_nohz(void)
8661 #ifdef CONFIG_NO_HZ_FULL
8662 /* Lock so we don't race with concurrent unaccount */
8663 spin_lock(&nr_freq_lock
);
8664 if (atomic_inc_return(&nr_freq_events
) == 1)
8665 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
8666 spin_unlock(&nr_freq_lock
);
8670 static void account_freq_event(void)
8672 if (tick_nohz_full_enabled())
8673 account_freq_event_nohz();
8675 atomic_inc(&nr_freq_events
);
8679 static void account_event(struct perf_event
*event
)
8686 if (event
->attach_state
& PERF_ATTACH_TASK
)
8688 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
8689 atomic_inc(&nr_mmap_events
);
8690 if (event
->attr
.comm
)
8691 atomic_inc(&nr_comm_events
);
8692 if (event
->attr
.task
)
8693 atomic_inc(&nr_task_events
);
8694 if (event
->attr
.freq
)
8695 account_freq_event();
8696 if (event
->attr
.context_switch
) {
8697 atomic_inc(&nr_switch_events
);
8700 if (has_branch_stack(event
))
8702 if (is_cgroup_event(event
))
8706 if (atomic_inc_not_zero(&perf_sched_count
))
8709 mutex_lock(&perf_sched_mutex
);
8710 if (!atomic_read(&perf_sched_count
)) {
8711 static_branch_enable(&perf_sched_events
);
8713 * Guarantee that all CPUs observe they key change and
8714 * call the perf scheduling hooks before proceeding to
8715 * install events that need them.
8717 synchronize_sched();
8720 * Now that we have waited for the sync_sched(), allow further
8721 * increments to by-pass the mutex.
8723 atomic_inc(&perf_sched_count
);
8724 mutex_unlock(&perf_sched_mutex
);
8728 account_event_cpu(event
, event
->cpu
);
8732 * Allocate and initialize a event structure
8734 static struct perf_event
*
8735 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
8736 struct task_struct
*task
,
8737 struct perf_event
*group_leader
,
8738 struct perf_event
*parent_event
,
8739 perf_overflow_handler_t overflow_handler
,
8740 void *context
, int cgroup_fd
)
8743 struct perf_event
*event
;
8744 struct hw_perf_event
*hwc
;
8747 if ((unsigned)cpu
>= nr_cpu_ids
) {
8748 if (!task
|| cpu
!= -1)
8749 return ERR_PTR(-EINVAL
);
8752 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
8754 return ERR_PTR(-ENOMEM
);
8757 * Single events are their own group leaders, with an
8758 * empty sibling list:
8761 group_leader
= event
;
8763 mutex_init(&event
->child_mutex
);
8764 INIT_LIST_HEAD(&event
->child_list
);
8766 INIT_LIST_HEAD(&event
->group_entry
);
8767 INIT_LIST_HEAD(&event
->event_entry
);
8768 INIT_LIST_HEAD(&event
->sibling_list
);
8769 INIT_LIST_HEAD(&event
->rb_entry
);
8770 INIT_LIST_HEAD(&event
->active_entry
);
8771 INIT_LIST_HEAD(&event
->addr_filters
.list
);
8772 INIT_HLIST_NODE(&event
->hlist_entry
);
8775 init_waitqueue_head(&event
->waitq
);
8776 init_irq_work(&event
->pending
, perf_pending_event
);
8778 mutex_init(&event
->mmap_mutex
);
8779 raw_spin_lock_init(&event
->addr_filters
.lock
);
8781 atomic_long_set(&event
->refcount
, 1);
8783 event
->attr
= *attr
;
8784 event
->group_leader
= group_leader
;
8788 event
->parent
= parent_event
;
8790 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
8791 event
->id
= atomic64_inc_return(&perf_event_id
);
8793 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8796 event
->attach_state
= PERF_ATTACH_TASK
;
8798 * XXX pmu::event_init needs to know what task to account to
8799 * and we cannot use the ctx information because we need the
8800 * pmu before we get a ctx.
8802 event
->hw
.target
= task
;
8805 event
->clock
= &local_clock
;
8807 event
->clock
= parent_event
->clock
;
8809 if (!overflow_handler
&& parent_event
) {
8810 overflow_handler
= parent_event
->overflow_handler
;
8811 context
= parent_event
->overflow_handler_context
;
8814 if (overflow_handler
) {
8815 event
->overflow_handler
= overflow_handler
;
8816 event
->overflow_handler_context
= context
;
8817 } else if (is_write_backward(event
)){
8818 event
->overflow_handler
= perf_event_output_backward
;
8819 event
->overflow_handler_context
= NULL
;
8821 event
->overflow_handler
= perf_event_output_forward
;
8822 event
->overflow_handler_context
= NULL
;
8825 perf_event__state_init(event
);
8830 hwc
->sample_period
= attr
->sample_period
;
8831 if (attr
->freq
&& attr
->sample_freq
)
8832 hwc
->sample_period
= 1;
8833 hwc
->last_period
= hwc
->sample_period
;
8835 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8838 * we currently do not support PERF_FORMAT_GROUP on inherited events
8840 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
8843 if (!has_branch_stack(event
))
8844 event
->attr
.branch_sample_type
= 0;
8846 if (cgroup_fd
!= -1) {
8847 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
8852 pmu
= perf_init_event(event
);
8855 else if (IS_ERR(pmu
)) {
8860 err
= exclusive_event_init(event
);
8864 if (has_addr_filter(event
)) {
8865 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
8866 sizeof(unsigned long),
8868 if (!event
->addr_filters_offs
)
8871 /* force hw sync on the address filters */
8872 event
->addr_filters_gen
= 1;
8875 if (!event
->parent
) {
8876 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
8877 err
= get_callchain_buffers();
8879 goto err_addr_filters
;
8883 /* symmetric to unaccount_event() in _free_event() */
8884 account_event(event
);
8889 kfree(event
->addr_filters_offs
);
8892 exclusive_event_destroy(event
);
8896 event
->destroy(event
);
8897 module_put(pmu
->module
);
8899 if (is_cgroup_event(event
))
8900 perf_detach_cgroup(event
);
8902 put_pid_ns(event
->ns
);
8905 return ERR_PTR(err
);
8908 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
8909 struct perf_event_attr
*attr
)
8914 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
8918 * zero the full structure, so that a short copy will be nice.
8920 memset(attr
, 0, sizeof(*attr
));
8922 ret
= get_user(size
, &uattr
->size
);
8926 if (size
> PAGE_SIZE
) /* silly large */
8929 if (!size
) /* abi compat */
8930 size
= PERF_ATTR_SIZE_VER0
;
8932 if (size
< PERF_ATTR_SIZE_VER0
)
8936 * If we're handed a bigger struct than we know of,
8937 * ensure all the unknown bits are 0 - i.e. new
8938 * user-space does not rely on any kernel feature
8939 * extensions we dont know about yet.
8941 if (size
> sizeof(*attr
)) {
8942 unsigned char __user
*addr
;
8943 unsigned char __user
*end
;
8946 addr
= (void __user
*)uattr
+ sizeof(*attr
);
8947 end
= (void __user
*)uattr
+ size
;
8949 for (; addr
< end
; addr
++) {
8950 ret
= get_user(val
, addr
);
8956 size
= sizeof(*attr
);
8959 ret
= copy_from_user(attr
, uattr
, size
);
8963 if (attr
->__reserved_1
)
8966 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
8969 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
8972 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
8973 u64 mask
= attr
->branch_sample_type
;
8975 /* only using defined bits */
8976 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
8979 /* at least one branch bit must be set */
8980 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
8983 /* propagate priv level, when not set for branch */
8984 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
8986 /* exclude_kernel checked on syscall entry */
8987 if (!attr
->exclude_kernel
)
8988 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8990 if (!attr
->exclude_user
)
8991 mask
|= PERF_SAMPLE_BRANCH_USER
;
8993 if (!attr
->exclude_hv
)
8994 mask
|= PERF_SAMPLE_BRANCH_HV
;
8996 * adjust user setting (for HW filter setup)
8998 attr
->branch_sample_type
= mask
;
9000 /* privileged levels capture (kernel, hv): check permissions */
9001 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9002 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9006 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9007 ret
= perf_reg_validate(attr
->sample_regs_user
);
9012 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9013 if (!arch_perf_have_user_stack_dump())
9017 * We have __u32 type for the size, but so far
9018 * we can only use __u16 as maximum due to the
9019 * __u16 sample size limit.
9021 if (attr
->sample_stack_user
>= USHRT_MAX
)
9023 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9027 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9028 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9033 put_user(sizeof(*attr
), &uattr
->size
);
9039 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9041 struct ring_buffer
*rb
= NULL
;
9047 /* don't allow circular references */
9048 if (event
== output_event
)
9052 * Don't allow cross-cpu buffers
9054 if (output_event
->cpu
!= event
->cpu
)
9058 * If its not a per-cpu rb, it must be the same task.
9060 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9064 * Mixing clocks in the same buffer is trouble you don't need.
9066 if (output_event
->clock
!= event
->clock
)
9070 * Either writing ring buffer from beginning or from end.
9071 * Mixing is not allowed.
9073 if (is_write_backward(output_event
) != is_write_backward(event
))
9077 * If both events generate aux data, they must be on the same PMU
9079 if (has_aux(event
) && has_aux(output_event
) &&
9080 event
->pmu
!= output_event
->pmu
)
9084 mutex_lock(&event
->mmap_mutex
);
9085 /* Can't redirect output if we've got an active mmap() */
9086 if (atomic_read(&event
->mmap_count
))
9090 /* get the rb we want to redirect to */
9091 rb
= ring_buffer_get(output_event
);
9096 ring_buffer_attach(event
, rb
);
9100 mutex_unlock(&event
->mmap_mutex
);
9106 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9112 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9115 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9117 bool nmi_safe
= false;
9120 case CLOCK_MONOTONIC
:
9121 event
->clock
= &ktime_get_mono_fast_ns
;
9125 case CLOCK_MONOTONIC_RAW
:
9126 event
->clock
= &ktime_get_raw_fast_ns
;
9130 case CLOCK_REALTIME
:
9131 event
->clock
= &ktime_get_real_ns
;
9134 case CLOCK_BOOTTIME
:
9135 event
->clock
= &ktime_get_boot_ns
;
9139 event
->clock
= &ktime_get_tai_ns
;
9146 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9153 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9155 * @attr_uptr: event_id type attributes for monitoring/sampling
9158 * @group_fd: group leader event fd
9160 SYSCALL_DEFINE5(perf_event_open
,
9161 struct perf_event_attr __user
*, attr_uptr
,
9162 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9164 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9165 struct perf_event
*event
, *sibling
;
9166 struct perf_event_attr attr
;
9167 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9168 struct file
*event_file
= NULL
;
9169 struct fd group
= {NULL
, 0};
9170 struct task_struct
*task
= NULL
;
9175 int f_flags
= O_RDWR
;
9178 /* for future expandability... */
9179 if (flags
& ~PERF_FLAG_ALL
)
9182 err
= perf_copy_attr(attr_uptr
, &attr
);
9186 if (!attr
.exclude_kernel
) {
9187 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9192 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9195 if (attr
.sample_period
& (1ULL << 63))
9200 * In cgroup mode, the pid argument is used to pass the fd
9201 * opened to the cgroup directory in cgroupfs. The cpu argument
9202 * designates the cpu on which to monitor threads from that
9205 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9208 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9209 f_flags
|= O_CLOEXEC
;
9211 event_fd
= get_unused_fd_flags(f_flags
);
9215 if (group_fd
!= -1) {
9216 err
= perf_fget_light(group_fd
, &group
);
9219 group_leader
= group
.file
->private_data
;
9220 if (flags
& PERF_FLAG_FD_OUTPUT
)
9221 output_event
= group_leader
;
9222 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9223 group_leader
= NULL
;
9226 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9227 task
= find_lively_task_by_vpid(pid
);
9229 err
= PTR_ERR(task
);
9234 if (task
&& group_leader
&&
9235 group_leader
->attr
.inherit
!= attr
.inherit
) {
9243 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
9248 * Reuse ptrace permission checks for now.
9250 * We must hold cred_guard_mutex across this and any potential
9251 * perf_install_in_context() call for this new event to
9252 * serialize against exec() altering our credentials (and the
9253 * perf_event_exit_task() that could imply).
9256 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
9260 if (flags
& PERF_FLAG_PID_CGROUP
)
9263 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
9264 NULL
, NULL
, cgroup_fd
);
9265 if (IS_ERR(event
)) {
9266 err
= PTR_ERR(event
);
9270 if (is_sampling_event(event
)) {
9271 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
9278 * Special case software events and allow them to be part of
9279 * any hardware group.
9283 if (attr
.use_clockid
) {
9284 err
= perf_event_set_clock(event
, attr
.clockid
);
9290 (is_software_event(event
) != is_software_event(group_leader
))) {
9291 if (is_software_event(event
)) {
9293 * If event and group_leader are not both a software
9294 * event, and event is, then group leader is not.
9296 * Allow the addition of software events to !software
9297 * groups, this is safe because software events never
9300 pmu
= group_leader
->pmu
;
9301 } else if (is_software_event(group_leader
) &&
9302 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
9304 * In case the group is a pure software group, and we
9305 * try to add a hardware event, move the whole group to
9306 * the hardware context.
9313 * Get the target context (task or percpu):
9315 ctx
= find_get_context(pmu
, task
, event
);
9321 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
9327 * Look up the group leader (we will attach this event to it):
9333 * Do not allow a recursive hierarchy (this new sibling
9334 * becoming part of another group-sibling):
9336 if (group_leader
->group_leader
!= group_leader
)
9339 /* All events in a group should have the same clock */
9340 if (group_leader
->clock
!= event
->clock
)
9344 * Do not allow to attach to a group in a different
9345 * task or CPU context:
9349 * Make sure we're both on the same task, or both
9352 if (group_leader
->ctx
->task
!= ctx
->task
)
9356 * Make sure we're both events for the same CPU;
9357 * grouping events for different CPUs is broken; since
9358 * you can never concurrently schedule them anyhow.
9360 if (group_leader
->cpu
!= event
->cpu
)
9363 if (group_leader
->ctx
!= ctx
)
9368 * Only a group leader can be exclusive or pinned
9370 if (attr
.exclusive
|| attr
.pinned
)
9375 err
= perf_event_set_output(event
, output_event
);
9380 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
9382 if (IS_ERR(event_file
)) {
9383 err
= PTR_ERR(event_file
);
9389 gctx
= group_leader
->ctx
;
9390 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9391 if (gctx
->task
== TASK_TOMBSTONE
) {
9396 mutex_lock(&ctx
->mutex
);
9399 if (ctx
->task
== TASK_TOMBSTONE
) {
9404 if (!perf_event_validate_size(event
)) {
9410 * Must be under the same ctx::mutex as perf_install_in_context(),
9411 * because we need to serialize with concurrent event creation.
9413 if (!exclusive_event_installable(event
, ctx
)) {
9414 /* exclusive and group stuff are assumed mutually exclusive */
9415 WARN_ON_ONCE(move_group
);
9421 WARN_ON_ONCE(ctx
->parent_ctx
);
9424 * This is the point on no return; we cannot fail hereafter. This is
9425 * where we start modifying current state.
9430 * See perf_event_ctx_lock() for comments on the details
9431 * of swizzling perf_event::ctx.
9433 perf_remove_from_context(group_leader
, 0);
9435 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
9437 perf_remove_from_context(sibling
, 0);
9442 * Wait for everybody to stop referencing the events through
9443 * the old lists, before installing it on new lists.
9448 * Install the group siblings before the group leader.
9450 * Because a group leader will try and install the entire group
9451 * (through the sibling list, which is still in-tact), we can
9452 * end up with siblings installed in the wrong context.
9454 * By installing siblings first we NO-OP because they're not
9455 * reachable through the group lists.
9457 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
9459 perf_event__state_init(sibling
);
9460 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
9465 * Removing from the context ends up with disabled
9466 * event. What we want here is event in the initial
9467 * startup state, ready to be add into new context.
9469 perf_event__state_init(group_leader
);
9470 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
9474 * Now that all events are installed in @ctx, nothing
9475 * references @gctx anymore, so drop the last reference we have
9482 * Precalculate sample_data sizes; do while holding ctx::mutex such
9483 * that we're serialized against further additions and before
9484 * perf_install_in_context() which is the point the event is active and
9485 * can use these values.
9487 perf_event__header_size(event
);
9488 perf_event__id_header_size(event
);
9490 event
->owner
= current
;
9492 perf_install_in_context(ctx
, event
, event
->cpu
);
9493 perf_unpin_context(ctx
);
9496 mutex_unlock(&gctx
->mutex
);
9497 mutex_unlock(&ctx
->mutex
);
9500 mutex_unlock(&task
->signal
->cred_guard_mutex
);
9501 put_task_struct(task
);
9506 mutex_lock(¤t
->perf_event_mutex
);
9507 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
9508 mutex_unlock(¤t
->perf_event_mutex
);
9511 * Drop the reference on the group_event after placing the
9512 * new event on the sibling_list. This ensures destruction
9513 * of the group leader will find the pointer to itself in
9514 * perf_group_detach().
9517 fd_install(event_fd
, event_file
);
9522 mutex_unlock(&gctx
->mutex
);
9523 mutex_unlock(&ctx
->mutex
);
9527 perf_unpin_context(ctx
);
9531 * If event_file is set, the fput() above will have called ->release()
9532 * and that will take care of freeing the event.
9538 mutex_unlock(&task
->signal
->cred_guard_mutex
);
9543 put_task_struct(task
);
9547 put_unused_fd(event_fd
);
9552 * perf_event_create_kernel_counter
9554 * @attr: attributes of the counter to create
9555 * @cpu: cpu in which the counter is bound
9556 * @task: task to profile (NULL for percpu)
9559 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
9560 struct task_struct
*task
,
9561 perf_overflow_handler_t overflow_handler
,
9564 struct perf_event_context
*ctx
;
9565 struct perf_event
*event
;
9569 * Get the target context (task or percpu):
9572 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
9573 overflow_handler
, context
, -1);
9574 if (IS_ERR(event
)) {
9575 err
= PTR_ERR(event
);
9579 /* Mark owner so we could distinguish it from user events. */
9580 event
->owner
= TASK_TOMBSTONE
;
9582 ctx
= find_get_context(event
->pmu
, task
, event
);
9588 WARN_ON_ONCE(ctx
->parent_ctx
);
9589 mutex_lock(&ctx
->mutex
);
9590 if (ctx
->task
== TASK_TOMBSTONE
) {
9595 if (!exclusive_event_installable(event
, ctx
)) {
9600 perf_install_in_context(ctx
, event
, cpu
);
9601 perf_unpin_context(ctx
);
9602 mutex_unlock(&ctx
->mutex
);
9607 mutex_unlock(&ctx
->mutex
);
9608 perf_unpin_context(ctx
);
9613 return ERR_PTR(err
);
9615 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
9617 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
9619 struct perf_event_context
*src_ctx
;
9620 struct perf_event_context
*dst_ctx
;
9621 struct perf_event
*event
, *tmp
;
9624 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
9625 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
9628 * See perf_event_ctx_lock() for comments on the details
9629 * of swizzling perf_event::ctx.
9631 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
9632 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
9634 perf_remove_from_context(event
, 0);
9635 unaccount_event_cpu(event
, src_cpu
);
9637 list_add(&event
->migrate_entry
, &events
);
9641 * Wait for the events to quiesce before re-instating them.
9646 * Re-instate events in 2 passes.
9648 * Skip over group leaders and only install siblings on this first
9649 * pass, siblings will not get enabled without a leader, however a
9650 * leader will enable its siblings, even if those are still on the old
9653 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
9654 if (event
->group_leader
== event
)
9657 list_del(&event
->migrate_entry
);
9658 if (event
->state
>= PERF_EVENT_STATE_OFF
)
9659 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9660 account_event_cpu(event
, dst_cpu
);
9661 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
9666 * Once all the siblings are setup properly, install the group leaders
9669 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
9670 list_del(&event
->migrate_entry
);
9671 if (event
->state
>= PERF_EVENT_STATE_OFF
)
9672 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9673 account_event_cpu(event
, dst_cpu
);
9674 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
9677 mutex_unlock(&dst_ctx
->mutex
);
9678 mutex_unlock(&src_ctx
->mutex
);
9680 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
9682 static void sync_child_event(struct perf_event
*child_event
,
9683 struct task_struct
*child
)
9685 struct perf_event
*parent_event
= child_event
->parent
;
9688 if (child_event
->attr
.inherit_stat
)
9689 perf_event_read_event(child_event
, child
);
9691 child_val
= perf_event_count(child_event
);
9694 * Add back the child's count to the parent's count:
9696 atomic64_add(child_val
, &parent_event
->child_count
);
9697 atomic64_add(child_event
->total_time_enabled
,
9698 &parent_event
->child_total_time_enabled
);
9699 atomic64_add(child_event
->total_time_running
,
9700 &parent_event
->child_total_time_running
);
9704 perf_event_exit_event(struct perf_event
*child_event
,
9705 struct perf_event_context
*child_ctx
,
9706 struct task_struct
*child
)
9708 struct perf_event
*parent_event
= child_event
->parent
;
9711 * Do not destroy the 'original' grouping; because of the context
9712 * switch optimization the original events could've ended up in a
9713 * random child task.
9715 * If we were to destroy the original group, all group related
9716 * operations would cease to function properly after this random
9719 * Do destroy all inherited groups, we don't care about those
9720 * and being thorough is better.
9722 raw_spin_lock_irq(&child_ctx
->lock
);
9723 WARN_ON_ONCE(child_ctx
->is_active
);
9726 perf_group_detach(child_event
);
9727 list_del_event(child_event
, child_ctx
);
9728 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
9729 raw_spin_unlock_irq(&child_ctx
->lock
);
9732 * Parent events are governed by their filedesc, retain them.
9734 if (!parent_event
) {
9735 perf_event_wakeup(child_event
);
9739 * Child events can be cleaned up.
9742 sync_child_event(child_event
, child
);
9745 * Remove this event from the parent's list
9747 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
9748 mutex_lock(&parent_event
->child_mutex
);
9749 list_del_init(&child_event
->child_list
);
9750 mutex_unlock(&parent_event
->child_mutex
);
9753 * Kick perf_poll() for is_event_hup().
9755 perf_event_wakeup(parent_event
);
9756 free_event(child_event
);
9757 put_event(parent_event
);
9760 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
9762 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
9763 struct perf_event
*child_event
, *next
;
9765 WARN_ON_ONCE(child
!= current
);
9767 child_ctx
= perf_pin_task_context(child
, ctxn
);
9772 * In order to reduce the amount of tricky in ctx tear-down, we hold
9773 * ctx::mutex over the entire thing. This serializes against almost
9774 * everything that wants to access the ctx.
9776 * The exception is sys_perf_event_open() /
9777 * perf_event_create_kernel_count() which does find_get_context()
9778 * without ctx::mutex (it cannot because of the move_group double mutex
9779 * lock thing). See the comments in perf_install_in_context().
9781 mutex_lock(&child_ctx
->mutex
);
9784 * In a single ctx::lock section, de-schedule the events and detach the
9785 * context from the task such that we cannot ever get it scheduled back
9788 raw_spin_lock_irq(&child_ctx
->lock
);
9789 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
);
9792 * Now that the context is inactive, destroy the task <-> ctx relation
9793 * and mark the context dead.
9795 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
9796 put_ctx(child_ctx
); /* cannot be last */
9797 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
9798 put_task_struct(current
); /* cannot be last */
9800 clone_ctx
= unclone_ctx(child_ctx
);
9801 raw_spin_unlock_irq(&child_ctx
->lock
);
9807 * Report the task dead after unscheduling the events so that we
9808 * won't get any samples after PERF_RECORD_EXIT. We can however still
9809 * get a few PERF_RECORD_READ events.
9811 perf_event_task(child
, child_ctx
, 0);
9813 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
9814 perf_event_exit_event(child_event
, child_ctx
, child
);
9816 mutex_unlock(&child_ctx
->mutex
);
9822 * When a child task exits, feed back event values to parent events.
9824 * Can be called with cred_guard_mutex held when called from
9825 * install_exec_creds().
9827 void perf_event_exit_task(struct task_struct
*child
)
9829 struct perf_event
*event
, *tmp
;
9832 mutex_lock(&child
->perf_event_mutex
);
9833 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
9835 list_del_init(&event
->owner_entry
);
9838 * Ensure the list deletion is visible before we clear
9839 * the owner, closes a race against perf_release() where
9840 * we need to serialize on the owner->perf_event_mutex.
9842 smp_store_release(&event
->owner
, NULL
);
9844 mutex_unlock(&child
->perf_event_mutex
);
9846 for_each_task_context_nr(ctxn
)
9847 perf_event_exit_task_context(child
, ctxn
);
9850 * The perf_event_exit_task_context calls perf_event_task
9851 * with child's task_ctx, which generates EXIT events for
9852 * child contexts and sets child->perf_event_ctxp[] to NULL.
9853 * At this point we need to send EXIT events to cpu contexts.
9855 perf_event_task(child
, NULL
, 0);
9858 static void perf_free_event(struct perf_event
*event
,
9859 struct perf_event_context
*ctx
)
9861 struct perf_event
*parent
= event
->parent
;
9863 if (WARN_ON_ONCE(!parent
))
9866 mutex_lock(&parent
->child_mutex
);
9867 list_del_init(&event
->child_list
);
9868 mutex_unlock(&parent
->child_mutex
);
9872 raw_spin_lock_irq(&ctx
->lock
);
9873 perf_group_detach(event
);
9874 list_del_event(event
, ctx
);
9875 raw_spin_unlock_irq(&ctx
->lock
);
9880 * Free an unexposed, unused context as created by inheritance by
9881 * perf_event_init_task below, used by fork() in case of fail.
9883 * Not all locks are strictly required, but take them anyway to be nice and
9884 * help out with the lockdep assertions.
9886 void perf_event_free_task(struct task_struct
*task
)
9888 struct perf_event_context
*ctx
;
9889 struct perf_event
*event
, *tmp
;
9892 for_each_task_context_nr(ctxn
) {
9893 ctx
= task
->perf_event_ctxp
[ctxn
];
9897 mutex_lock(&ctx
->mutex
);
9899 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
9901 perf_free_event(event
, ctx
);
9903 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
9905 perf_free_event(event
, ctx
);
9907 if (!list_empty(&ctx
->pinned_groups
) ||
9908 !list_empty(&ctx
->flexible_groups
))
9911 mutex_unlock(&ctx
->mutex
);
9917 void perf_event_delayed_put(struct task_struct
*task
)
9921 for_each_task_context_nr(ctxn
)
9922 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
9925 struct file
*perf_event_get(unsigned int fd
)
9929 file
= fget_raw(fd
);
9931 return ERR_PTR(-EBADF
);
9933 if (file
->f_op
!= &perf_fops
) {
9935 return ERR_PTR(-EBADF
);
9941 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
9944 return ERR_PTR(-EINVAL
);
9946 return &event
->attr
;
9950 * inherit a event from parent task to child task:
9952 static struct perf_event
*
9953 inherit_event(struct perf_event
*parent_event
,
9954 struct task_struct
*parent
,
9955 struct perf_event_context
*parent_ctx
,
9956 struct task_struct
*child
,
9957 struct perf_event
*group_leader
,
9958 struct perf_event_context
*child_ctx
)
9960 enum perf_event_active_state parent_state
= parent_event
->state
;
9961 struct perf_event
*child_event
;
9962 unsigned long flags
;
9965 * Instead of creating recursive hierarchies of events,
9966 * we link inherited events back to the original parent,
9967 * which has a filp for sure, which we use as the reference
9970 if (parent_event
->parent
)
9971 parent_event
= parent_event
->parent
;
9973 child_event
= perf_event_alloc(&parent_event
->attr
,
9976 group_leader
, parent_event
,
9978 if (IS_ERR(child_event
))
9982 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
9983 * must be under the same lock in order to serialize against
9984 * perf_event_release_kernel(), such that either we must observe
9985 * is_orphaned_event() or they will observe us on the child_list.
9987 mutex_lock(&parent_event
->child_mutex
);
9988 if (is_orphaned_event(parent_event
) ||
9989 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
9990 mutex_unlock(&parent_event
->child_mutex
);
9991 free_event(child_event
);
9998 * Make the child state follow the state of the parent event,
9999 * not its attr.disabled bit. We hold the parent's mutex,
10000 * so we won't race with perf_event_{en, dis}able_family.
10002 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10003 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10005 child_event
->state
= PERF_EVENT_STATE_OFF
;
10007 if (parent_event
->attr
.freq
) {
10008 u64 sample_period
= parent_event
->hw
.sample_period
;
10009 struct hw_perf_event
*hwc
= &child_event
->hw
;
10011 hwc
->sample_period
= sample_period
;
10012 hwc
->last_period
= sample_period
;
10014 local64_set(&hwc
->period_left
, sample_period
);
10017 child_event
->ctx
= child_ctx
;
10018 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10019 child_event
->overflow_handler_context
10020 = parent_event
->overflow_handler_context
;
10023 * Precalculate sample_data sizes
10025 perf_event__header_size(child_event
);
10026 perf_event__id_header_size(child_event
);
10029 * Link it up in the child's context:
10031 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10032 add_event_to_ctx(child_event
, child_ctx
);
10033 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10036 * Link this into the parent event's child list
10038 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10039 mutex_unlock(&parent_event
->child_mutex
);
10041 return child_event
;
10044 static int inherit_group(struct perf_event
*parent_event
,
10045 struct task_struct
*parent
,
10046 struct perf_event_context
*parent_ctx
,
10047 struct task_struct
*child
,
10048 struct perf_event_context
*child_ctx
)
10050 struct perf_event
*leader
;
10051 struct perf_event
*sub
;
10052 struct perf_event
*child_ctr
;
10054 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10055 child
, NULL
, child_ctx
);
10056 if (IS_ERR(leader
))
10057 return PTR_ERR(leader
);
10058 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10059 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10060 child
, leader
, child_ctx
);
10061 if (IS_ERR(child_ctr
))
10062 return PTR_ERR(child_ctr
);
10068 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10069 struct perf_event_context
*parent_ctx
,
10070 struct task_struct
*child
, int ctxn
,
10071 int *inherited_all
)
10074 struct perf_event_context
*child_ctx
;
10076 if (!event
->attr
.inherit
) {
10077 *inherited_all
= 0;
10081 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10084 * This is executed from the parent task context, so
10085 * inherit events that have been marked for cloning.
10086 * First allocate and initialize a context for the
10090 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10094 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10097 ret
= inherit_group(event
, parent
, parent_ctx
,
10101 *inherited_all
= 0;
10107 * Initialize the perf_event context in task_struct
10109 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10111 struct perf_event_context
*child_ctx
, *parent_ctx
;
10112 struct perf_event_context
*cloned_ctx
;
10113 struct perf_event
*event
;
10114 struct task_struct
*parent
= current
;
10115 int inherited_all
= 1;
10116 unsigned long flags
;
10119 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10123 * If the parent's context is a clone, pin it so it won't get
10124 * swapped under us.
10126 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10131 * No need to check if parent_ctx != NULL here; since we saw
10132 * it non-NULL earlier, the only reason for it to become NULL
10133 * is if we exit, and since we're currently in the middle of
10134 * a fork we can't be exiting at the same time.
10138 * Lock the parent list. No need to lock the child - not PID
10139 * hashed yet and not running, so nobody can access it.
10141 mutex_lock(&parent_ctx
->mutex
);
10144 * We dont have to disable NMIs - we are only looking at
10145 * the list, not manipulating it:
10147 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10148 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10149 child
, ctxn
, &inherited_all
);
10155 * We can't hold ctx->lock when iterating the ->flexible_group list due
10156 * to allocations, but we need to prevent rotation because
10157 * rotate_ctx() will change the list from interrupt context.
10159 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10160 parent_ctx
->rotate_disable
= 1;
10161 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10163 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10164 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10165 child
, ctxn
, &inherited_all
);
10170 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10171 parent_ctx
->rotate_disable
= 0;
10173 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10175 if (child_ctx
&& inherited_all
) {
10177 * Mark the child context as a clone of the parent
10178 * context, or of whatever the parent is a clone of.
10180 * Note that if the parent is a clone, the holding of
10181 * parent_ctx->lock avoids it from being uncloned.
10183 cloned_ctx
= parent_ctx
->parent_ctx
;
10185 child_ctx
->parent_ctx
= cloned_ctx
;
10186 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
10188 child_ctx
->parent_ctx
= parent_ctx
;
10189 child_ctx
->parent_gen
= parent_ctx
->generation
;
10191 get_ctx(child_ctx
->parent_ctx
);
10194 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10195 mutex_unlock(&parent_ctx
->mutex
);
10197 perf_unpin_context(parent_ctx
);
10198 put_ctx(parent_ctx
);
10204 * Initialize the perf_event context in task_struct
10206 int perf_event_init_task(struct task_struct
*child
)
10210 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
10211 mutex_init(&child
->perf_event_mutex
);
10212 INIT_LIST_HEAD(&child
->perf_event_list
);
10214 for_each_task_context_nr(ctxn
) {
10215 ret
= perf_event_init_context(child
, ctxn
);
10217 perf_event_free_task(child
);
10225 static void __init
perf_event_init_all_cpus(void)
10227 struct swevent_htable
*swhash
;
10230 for_each_possible_cpu(cpu
) {
10231 swhash
= &per_cpu(swevent_htable
, cpu
);
10232 mutex_init(&swhash
->hlist_mutex
);
10233 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
10237 static void perf_event_init_cpu(int cpu
)
10239 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
10241 mutex_lock(&swhash
->hlist_mutex
);
10242 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
10243 struct swevent_hlist
*hlist
;
10245 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
10247 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
10249 mutex_unlock(&swhash
->hlist_mutex
);
10252 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
10253 static void __perf_event_exit_context(void *__info
)
10255 struct perf_event_context
*ctx
= __info
;
10256 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
10257 struct perf_event
*event
;
10259 raw_spin_lock(&ctx
->lock
);
10260 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
10261 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
10262 raw_spin_unlock(&ctx
->lock
);
10265 static void perf_event_exit_cpu_context(int cpu
)
10267 struct perf_event_context
*ctx
;
10271 idx
= srcu_read_lock(&pmus_srcu
);
10272 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
10273 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
10275 mutex_lock(&ctx
->mutex
);
10276 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
10277 mutex_unlock(&ctx
->mutex
);
10279 srcu_read_unlock(&pmus_srcu
, idx
);
10282 static void perf_event_exit_cpu(int cpu
)
10284 perf_event_exit_cpu_context(cpu
);
10287 static inline void perf_event_exit_cpu(int cpu
) { }
10291 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
10295 for_each_online_cpu(cpu
)
10296 perf_event_exit_cpu(cpu
);
10302 * Run the perf reboot notifier at the very last possible moment so that
10303 * the generic watchdog code runs as long as possible.
10305 static struct notifier_block perf_reboot_notifier
= {
10306 .notifier_call
= perf_reboot
,
10307 .priority
= INT_MIN
,
10311 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
10313 unsigned int cpu
= (long)hcpu
;
10315 switch (action
& ~CPU_TASKS_FROZEN
) {
10317 case CPU_UP_PREPARE
:
10319 * This must be done before the CPU comes alive, because the
10320 * moment we can run tasks we can encounter (software) events.
10322 * Specifically, someone can have inherited events on kthreadd
10323 * or a pre-existing worker thread that gets re-bound.
10325 perf_event_init_cpu(cpu
);
10328 case CPU_DOWN_PREPARE
:
10330 * This must be done before the CPU dies because after that an
10331 * active event might want to IPI the CPU and that'll not work
10332 * so great for dead CPUs.
10334 * XXX smp_call_function_single() return -ENXIO without a warn
10335 * so we could possibly deal with this.
10337 * This is safe against new events arriving because
10338 * sys_perf_event_open() serializes against hotplug using
10339 * get_online_cpus().
10341 perf_event_exit_cpu(cpu
);
10350 void __init
perf_event_init(void)
10354 idr_init(&pmu_idr
);
10356 perf_event_init_all_cpus();
10357 init_srcu_struct(&pmus_srcu
);
10358 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
10359 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
10360 perf_pmu_register(&perf_task_clock
, NULL
, -1);
10361 perf_tp_register();
10362 perf_cpu_notifier(perf_cpu_notify
);
10363 register_reboot_notifier(&perf_reboot_notifier
);
10365 ret
= init_hw_breakpoint();
10366 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
10369 * Build time assertion that we keep the data_head at the intended
10370 * location. IOW, validation we got the __reserved[] size right.
10372 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
10376 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
10379 struct perf_pmu_events_attr
*pmu_attr
=
10380 container_of(attr
, struct perf_pmu_events_attr
, attr
);
10382 if (pmu_attr
->event_str
)
10383 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
10387 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
10389 static int __init
perf_event_sysfs_init(void)
10394 mutex_lock(&pmus_lock
);
10396 ret
= bus_register(&pmu_bus
);
10400 list_for_each_entry(pmu
, &pmus
, entry
) {
10401 if (!pmu
->name
|| pmu
->type
< 0)
10404 ret
= pmu_dev_alloc(pmu
);
10405 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
10407 pmu_bus_running
= 1;
10411 mutex_unlock(&pmus_lock
);
10415 device_initcall(perf_event_sysfs_init
);
10417 #ifdef CONFIG_CGROUP_PERF
10418 static struct cgroup_subsys_state
*
10419 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
10421 struct perf_cgroup
*jc
;
10423 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
10425 return ERR_PTR(-ENOMEM
);
10427 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
10430 return ERR_PTR(-ENOMEM
);
10436 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
10438 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
10440 free_percpu(jc
->info
);
10444 static int __perf_cgroup_move(void *info
)
10446 struct task_struct
*task
= info
;
10448 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
10453 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
10455 struct task_struct
*task
;
10456 struct cgroup_subsys_state
*css
;
10458 cgroup_taskset_for_each(task
, css
, tset
)
10459 task_function_call(task
, __perf_cgroup_move
, task
);
10462 struct cgroup_subsys perf_event_cgrp_subsys
= {
10463 .css_alloc
= perf_cgroup_css_alloc
,
10464 .css_free
= perf_cgroup_css_free
,
10465 .attach
= perf_cgroup_attach
,
10467 #endif /* CONFIG_CGROUP_PERF */