2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
50 #include <asm/irq_regs.h>
52 typedef int (*remote_function_f
)(void *);
54 struct remote_function_call
{
55 struct task_struct
*p
;
56 remote_function_f func
;
61 static void remote_function(void *data
)
63 struct remote_function_call
*tfc
= data
;
64 struct task_struct
*p
= tfc
->p
;
68 if (task_cpu(p
) != smp_processor_id())
72 * Now that we're on right CPU with IRQs disabled, we can test
73 * if we hit the right task without races.
76 tfc
->ret
= -ESRCH
; /* No such (running) process */
81 tfc
->ret
= tfc
->func(tfc
->info
);
85 * task_function_call - call a function on the cpu on which a task runs
86 * @p: the task to evaluate
87 * @func: the function to be called
88 * @info: the function call argument
90 * Calls the function @func when the task is currently running. This might
91 * be on the current CPU, which just calls the function directly
93 * returns: @func return value, or
94 * -ESRCH - when the process isn't running
95 * -EAGAIN - when the process moved away
98 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
100 struct remote_function_call data
= {
109 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
112 } while (ret
== -EAGAIN
);
118 * cpu_function_call - call a function on the cpu
119 * @func: the function to be called
120 * @info: the function call argument
122 * Calls the function @func on the remote cpu.
124 * returns: @func return value or -ENXIO when the cpu is offline
126 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
128 struct remote_function_call data
= {
132 .ret
= -ENXIO
, /* No such CPU */
135 smp_call_function_single(cpu
, remote_function
, &data
, 1);
140 static inline struct perf_cpu_context
*
141 __get_cpu_context(struct perf_event_context
*ctx
)
143 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
146 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
147 struct perf_event_context
*ctx
)
149 raw_spin_lock(&cpuctx
->ctx
.lock
);
151 raw_spin_lock(&ctx
->lock
);
154 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
155 struct perf_event_context
*ctx
)
158 raw_spin_unlock(&ctx
->lock
);
159 raw_spin_unlock(&cpuctx
->ctx
.lock
);
162 #define TASK_TOMBSTONE ((void *)-1L)
164 static bool is_kernel_event(struct perf_event
*event
)
166 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
170 * On task ctx scheduling...
172 * When !ctx->nr_events a task context will not be scheduled. This means
173 * we can disable the scheduler hooks (for performance) without leaving
174 * pending task ctx state.
176 * This however results in two special cases:
178 * - removing the last event from a task ctx; this is relatively straight
179 * forward and is done in __perf_remove_from_context.
181 * - adding the first event to a task ctx; this is tricky because we cannot
182 * rely on ctx->is_active and therefore cannot use event_function_call().
183 * See perf_install_in_context().
185 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
188 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
189 struct perf_event_context
*, void *);
191 struct event_function_struct
{
192 struct perf_event
*event
;
197 static int event_function(void *info
)
199 struct event_function_struct
*efs
= info
;
200 struct perf_event
*event
= efs
->event
;
201 struct perf_event_context
*ctx
= event
->ctx
;
202 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
203 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
206 WARN_ON_ONCE(!irqs_disabled());
208 perf_ctx_lock(cpuctx
, task_ctx
);
210 * Since we do the IPI call without holding ctx->lock things can have
211 * changed, double check we hit the task we set out to hit.
214 if (ctx
->task
!= current
) {
220 * We only use event_function_call() on established contexts,
221 * and event_function() is only ever called when active (or
222 * rather, we'll have bailed in task_function_call() or the
223 * above ctx->task != current test), therefore we must have
224 * ctx->is_active here.
226 WARN_ON_ONCE(!ctx
->is_active
);
228 * And since we have ctx->is_active, cpuctx->task_ctx must
231 WARN_ON_ONCE(task_ctx
!= ctx
);
233 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
236 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
238 perf_ctx_unlock(cpuctx
, task_ctx
);
243 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
245 struct event_function_struct efs
= {
251 int ret
= event_function(&efs
);
255 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
257 struct perf_event_context
*ctx
= event
->ctx
;
258 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
259 struct event_function_struct efs
= {
265 if (!event
->parent
) {
267 * If this is a !child event, we must hold ctx::mutex to
268 * stabilize the the event->ctx relation. See
269 * perf_event_ctx_lock().
271 lockdep_assert_held(&ctx
->mutex
);
275 cpu_function_call(event
->cpu
, event_function
, &efs
);
279 if (task
== TASK_TOMBSTONE
)
283 if (!task_function_call(task
, event_function
, &efs
))
286 raw_spin_lock_irq(&ctx
->lock
);
288 * Reload the task pointer, it might have been changed by
289 * a concurrent perf_event_context_sched_out().
292 if (task
== TASK_TOMBSTONE
) {
293 raw_spin_unlock_irq(&ctx
->lock
);
296 if (ctx
->is_active
) {
297 raw_spin_unlock_irq(&ctx
->lock
);
300 func(event
, NULL
, ctx
, data
);
301 raw_spin_unlock_irq(&ctx
->lock
);
304 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
305 PERF_FLAG_FD_OUTPUT |\
306 PERF_FLAG_PID_CGROUP |\
307 PERF_FLAG_FD_CLOEXEC)
310 * branch priv levels that need permission checks
312 #define PERF_SAMPLE_BRANCH_PERM_PLM \
313 (PERF_SAMPLE_BRANCH_KERNEL |\
314 PERF_SAMPLE_BRANCH_HV)
317 EVENT_FLEXIBLE
= 0x1,
320 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
324 * perf_sched_events : >0 events exist
325 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
328 static void perf_sched_delayed(struct work_struct
*work
);
329 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
330 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
331 static DEFINE_MUTEX(perf_sched_mutex
);
332 static atomic_t perf_sched_count
;
334 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
335 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
337 static atomic_t nr_mmap_events __read_mostly
;
338 static atomic_t nr_comm_events __read_mostly
;
339 static atomic_t nr_task_events __read_mostly
;
340 static atomic_t nr_freq_events __read_mostly
;
341 static atomic_t nr_switch_events __read_mostly
;
343 static LIST_HEAD(pmus
);
344 static DEFINE_MUTEX(pmus_lock
);
345 static struct srcu_struct pmus_srcu
;
348 * perf event paranoia level:
349 * -1 - not paranoid at all
350 * 0 - disallow raw tracepoint access for unpriv
351 * 1 - disallow cpu events for unpriv
352 * 2 - disallow kernel profiling for unpriv
354 int sysctl_perf_event_paranoid __read_mostly
= 1;
356 /* Minimum for 512 kiB + 1 user control page */
357 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
360 * max perf event sample rate
362 #define DEFAULT_MAX_SAMPLE_RATE 100000
363 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
364 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
366 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
368 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
369 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
371 static int perf_sample_allowed_ns __read_mostly
=
372 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
374 static void update_perf_cpu_limits(void)
376 u64 tmp
= perf_sample_period_ns
;
378 tmp
*= sysctl_perf_cpu_time_max_percent
;
379 tmp
= div_u64(tmp
, 100);
383 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
386 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
388 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
389 void __user
*buffer
, size_t *lenp
,
392 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
397 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
398 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
399 update_perf_cpu_limits();
404 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
406 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
407 void __user
*buffer
, size_t *lenp
,
410 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
415 if (sysctl_perf_cpu_time_max_percent
== 100) {
417 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
418 WRITE_ONCE(perf_sample_allowed_ns
, 0);
420 update_perf_cpu_limits();
427 * perf samples are done in some very critical code paths (NMIs).
428 * If they take too much CPU time, the system can lock up and not
429 * get any real work done. This will drop the sample rate when
430 * we detect that events are taking too long.
432 #define NR_ACCUMULATED_SAMPLES 128
433 static DEFINE_PER_CPU(u64
, running_sample_length
);
435 static u64 __report_avg
;
436 static u64 __report_allowed
;
438 static void perf_duration_warn(struct irq_work
*w
)
440 printk_ratelimited(KERN_WARNING
441 "perf: interrupt took too long (%lld > %lld), lowering "
442 "kernel.perf_event_max_sample_rate to %d\n",
443 __report_avg
, __report_allowed
,
444 sysctl_perf_event_sample_rate
);
447 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
449 void perf_sample_event_took(u64 sample_len_ns
)
451 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
459 /* Decay the counter by 1 average sample. */
460 running_len
= __this_cpu_read(running_sample_length
);
461 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
462 running_len
+= sample_len_ns
;
463 __this_cpu_write(running_sample_length
, running_len
);
466 * Note: this will be biased artifically low until we have
467 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
468 * from having to maintain a count.
470 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
471 if (avg_len
<= max_len
)
474 __report_avg
= avg_len
;
475 __report_allowed
= max_len
;
478 * Compute a throttle threshold 25% below the current duration.
480 avg_len
+= avg_len
/ 4;
481 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
487 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
488 WRITE_ONCE(max_samples_per_tick
, max
);
490 sysctl_perf_event_sample_rate
= max
* HZ
;
491 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
493 if (!irq_work_queue(&perf_duration_work
)) {
494 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
495 "kernel.perf_event_max_sample_rate to %d\n",
496 __report_avg
, __report_allowed
,
497 sysctl_perf_event_sample_rate
);
501 static atomic64_t perf_event_id
;
503 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
504 enum event_type_t event_type
);
506 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
507 enum event_type_t event_type
,
508 struct task_struct
*task
);
510 static void update_context_time(struct perf_event_context
*ctx
);
511 static u64
perf_event_time(struct perf_event
*event
);
513 void __weak
perf_event_print_debug(void) { }
515 extern __weak
const char *perf_pmu_name(void)
520 static inline u64
perf_clock(void)
522 return local_clock();
525 static inline u64
perf_event_clock(struct perf_event
*event
)
527 return event
->clock();
530 #ifdef CONFIG_CGROUP_PERF
533 perf_cgroup_match(struct perf_event
*event
)
535 struct perf_event_context
*ctx
= event
->ctx
;
536 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
538 /* @event doesn't care about cgroup */
542 /* wants specific cgroup scope but @cpuctx isn't associated with any */
547 * Cgroup scoping is recursive. An event enabled for a cgroup is
548 * also enabled for all its descendant cgroups. If @cpuctx's
549 * cgroup is a descendant of @event's (the test covers identity
550 * case), it's a match.
552 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
553 event
->cgrp
->css
.cgroup
);
556 static inline void perf_detach_cgroup(struct perf_event
*event
)
558 css_put(&event
->cgrp
->css
);
562 static inline int is_cgroup_event(struct perf_event
*event
)
564 return event
->cgrp
!= NULL
;
567 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
569 struct perf_cgroup_info
*t
;
571 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
575 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
577 struct perf_cgroup_info
*info
;
582 info
= this_cpu_ptr(cgrp
->info
);
584 info
->time
+= now
- info
->timestamp
;
585 info
->timestamp
= now
;
588 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
590 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
592 __update_cgrp_time(cgrp_out
);
595 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
597 struct perf_cgroup
*cgrp
;
600 * ensure we access cgroup data only when needed and
601 * when we know the cgroup is pinned (css_get)
603 if (!is_cgroup_event(event
))
606 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
608 * Do not update time when cgroup is not active
610 if (cgrp
== event
->cgrp
)
611 __update_cgrp_time(event
->cgrp
);
615 perf_cgroup_set_timestamp(struct task_struct
*task
,
616 struct perf_event_context
*ctx
)
618 struct perf_cgroup
*cgrp
;
619 struct perf_cgroup_info
*info
;
622 * ctx->lock held by caller
623 * ensure we do not access cgroup data
624 * unless we have the cgroup pinned (css_get)
626 if (!task
|| !ctx
->nr_cgroups
)
629 cgrp
= perf_cgroup_from_task(task
, ctx
);
630 info
= this_cpu_ptr(cgrp
->info
);
631 info
->timestamp
= ctx
->timestamp
;
634 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
635 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
638 * reschedule events based on the cgroup constraint of task.
640 * mode SWOUT : schedule out everything
641 * mode SWIN : schedule in based on cgroup for next
643 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
645 struct perf_cpu_context
*cpuctx
;
650 * disable interrupts to avoid geting nr_cgroup
651 * changes via __perf_event_disable(). Also
654 local_irq_save(flags
);
657 * we reschedule only in the presence of cgroup
658 * constrained events.
661 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
662 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
663 if (cpuctx
->unique_pmu
!= pmu
)
664 continue; /* ensure we process each cpuctx once */
667 * perf_cgroup_events says at least one
668 * context on this CPU has cgroup events.
670 * ctx->nr_cgroups reports the number of cgroup
671 * events for a context.
673 if (cpuctx
->ctx
.nr_cgroups
> 0) {
674 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
675 perf_pmu_disable(cpuctx
->ctx
.pmu
);
677 if (mode
& PERF_CGROUP_SWOUT
) {
678 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
680 * must not be done before ctxswout due
681 * to event_filter_match() in event_sched_out()
686 if (mode
& PERF_CGROUP_SWIN
) {
687 WARN_ON_ONCE(cpuctx
->cgrp
);
689 * set cgrp before ctxsw in to allow
690 * event_filter_match() to not have to pass
692 * we pass the cpuctx->ctx to perf_cgroup_from_task()
693 * because cgorup events are only per-cpu
695 cpuctx
->cgrp
= perf_cgroup_from_task(task
, &cpuctx
->ctx
);
696 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
698 perf_pmu_enable(cpuctx
->ctx
.pmu
);
699 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
703 local_irq_restore(flags
);
706 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
707 struct task_struct
*next
)
709 struct perf_cgroup
*cgrp1
;
710 struct perf_cgroup
*cgrp2
= NULL
;
714 * we come here when we know perf_cgroup_events > 0
715 * we do not need to pass the ctx here because we know
716 * we are holding the rcu lock
718 cgrp1
= perf_cgroup_from_task(task
, NULL
);
719 cgrp2
= perf_cgroup_from_task(next
, NULL
);
722 * only schedule out current cgroup events if we know
723 * that we are switching to a different cgroup. Otherwise,
724 * do no touch the cgroup events.
727 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
732 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
733 struct task_struct
*task
)
735 struct perf_cgroup
*cgrp1
;
736 struct perf_cgroup
*cgrp2
= NULL
;
740 * we come here when we know perf_cgroup_events > 0
741 * we do not need to pass the ctx here because we know
742 * we are holding the rcu lock
744 cgrp1
= perf_cgroup_from_task(task
, NULL
);
745 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
748 * only need to schedule in cgroup events if we are changing
749 * cgroup during ctxsw. Cgroup events were not scheduled
750 * out of ctxsw out if that was not the case.
753 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
758 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
759 struct perf_event_attr
*attr
,
760 struct perf_event
*group_leader
)
762 struct perf_cgroup
*cgrp
;
763 struct cgroup_subsys_state
*css
;
764 struct fd f
= fdget(fd
);
770 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
771 &perf_event_cgrp_subsys
);
777 cgrp
= container_of(css
, struct perf_cgroup
, css
);
781 * all events in a group must monitor
782 * the same cgroup because a task belongs
783 * to only one perf cgroup at a time
785 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
786 perf_detach_cgroup(event
);
795 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
797 struct perf_cgroup_info
*t
;
798 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
799 event
->shadow_ctx_time
= now
- t
->timestamp
;
803 perf_cgroup_defer_enabled(struct perf_event
*event
)
806 * when the current task's perf cgroup does not match
807 * the event's, we need to remember to call the
808 * perf_mark_enable() function the first time a task with
809 * a matching perf cgroup is scheduled in.
811 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
812 event
->cgrp_defer_enabled
= 1;
816 perf_cgroup_mark_enabled(struct perf_event
*event
,
817 struct perf_event_context
*ctx
)
819 struct perf_event
*sub
;
820 u64 tstamp
= perf_event_time(event
);
822 if (!event
->cgrp_defer_enabled
)
825 event
->cgrp_defer_enabled
= 0;
827 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
828 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
829 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
830 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
831 sub
->cgrp_defer_enabled
= 0;
835 #else /* !CONFIG_CGROUP_PERF */
838 perf_cgroup_match(struct perf_event
*event
)
843 static inline void perf_detach_cgroup(struct perf_event
*event
)
846 static inline int is_cgroup_event(struct perf_event
*event
)
851 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
856 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
860 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
864 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
865 struct task_struct
*next
)
869 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
870 struct task_struct
*task
)
874 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
875 struct perf_event_attr
*attr
,
876 struct perf_event
*group_leader
)
882 perf_cgroup_set_timestamp(struct task_struct
*task
,
883 struct perf_event_context
*ctx
)
888 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
893 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
897 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
903 perf_cgroup_defer_enabled(struct perf_event
*event
)
908 perf_cgroup_mark_enabled(struct perf_event
*event
,
909 struct perf_event_context
*ctx
)
915 * set default to be dependent on timer tick just
918 #define PERF_CPU_HRTIMER (1000 / HZ)
920 * function must be called with interrupts disbled
922 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
924 struct perf_cpu_context
*cpuctx
;
927 WARN_ON(!irqs_disabled());
929 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
930 rotations
= perf_rotate_context(cpuctx
);
932 raw_spin_lock(&cpuctx
->hrtimer_lock
);
934 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
936 cpuctx
->hrtimer_active
= 0;
937 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
939 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
942 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
944 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
945 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
948 /* no multiplexing needed for SW PMU */
949 if (pmu
->task_ctx_nr
== perf_sw_context
)
953 * check default is sane, if not set then force to
954 * default interval (1/tick)
956 interval
= pmu
->hrtimer_interval_ms
;
958 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
960 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
962 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
963 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
964 timer
->function
= perf_mux_hrtimer_handler
;
967 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
969 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
970 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
974 if (pmu
->task_ctx_nr
== perf_sw_context
)
977 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
978 if (!cpuctx
->hrtimer_active
) {
979 cpuctx
->hrtimer_active
= 1;
980 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
981 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
983 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
988 void perf_pmu_disable(struct pmu
*pmu
)
990 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
992 pmu
->pmu_disable(pmu
);
995 void perf_pmu_enable(struct pmu
*pmu
)
997 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
999 pmu
->pmu_enable(pmu
);
1002 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1005 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1006 * perf_event_task_tick() are fully serialized because they're strictly cpu
1007 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1008 * disabled, while perf_event_task_tick is called from IRQ context.
1010 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1012 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1014 WARN_ON(!irqs_disabled());
1016 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1018 list_add(&ctx
->active_ctx_list
, head
);
1021 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1023 WARN_ON(!irqs_disabled());
1025 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1027 list_del_init(&ctx
->active_ctx_list
);
1030 static void get_ctx(struct perf_event_context
*ctx
)
1032 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1035 static void free_ctx(struct rcu_head
*head
)
1037 struct perf_event_context
*ctx
;
1039 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1040 kfree(ctx
->task_ctx_data
);
1044 static void put_ctx(struct perf_event_context
*ctx
)
1046 if (atomic_dec_and_test(&ctx
->refcount
)) {
1047 if (ctx
->parent_ctx
)
1048 put_ctx(ctx
->parent_ctx
);
1049 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1050 put_task_struct(ctx
->task
);
1051 call_rcu(&ctx
->rcu_head
, free_ctx
);
1056 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1057 * perf_pmu_migrate_context() we need some magic.
1059 * Those places that change perf_event::ctx will hold both
1060 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1062 * Lock ordering is by mutex address. There are two other sites where
1063 * perf_event_context::mutex nests and those are:
1065 * - perf_event_exit_task_context() [ child , 0 ]
1066 * perf_event_exit_event()
1067 * put_event() [ parent, 1 ]
1069 * - perf_event_init_context() [ parent, 0 ]
1070 * inherit_task_group()
1073 * perf_event_alloc()
1075 * perf_try_init_event() [ child , 1 ]
1077 * While it appears there is an obvious deadlock here -- the parent and child
1078 * nesting levels are inverted between the two. This is in fact safe because
1079 * life-time rules separate them. That is an exiting task cannot fork, and a
1080 * spawning task cannot (yet) exit.
1082 * But remember that that these are parent<->child context relations, and
1083 * migration does not affect children, therefore these two orderings should not
1086 * The change in perf_event::ctx does not affect children (as claimed above)
1087 * because the sys_perf_event_open() case will install a new event and break
1088 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1089 * concerned with cpuctx and that doesn't have children.
1091 * The places that change perf_event::ctx will issue:
1093 * perf_remove_from_context();
1094 * synchronize_rcu();
1095 * perf_install_in_context();
1097 * to affect the change. The remove_from_context() + synchronize_rcu() should
1098 * quiesce the event, after which we can install it in the new location. This
1099 * means that only external vectors (perf_fops, prctl) can perturb the event
1100 * while in transit. Therefore all such accessors should also acquire
1101 * perf_event_context::mutex to serialize against this.
1103 * However; because event->ctx can change while we're waiting to acquire
1104 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1108 * task_struct::perf_event_mutex
1109 * perf_event_context::mutex
1110 * perf_event::child_mutex;
1111 * perf_event_context::lock
1112 * perf_event::mmap_mutex
1115 static struct perf_event_context
*
1116 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1118 struct perf_event_context
*ctx
;
1122 ctx
= ACCESS_ONCE(event
->ctx
);
1123 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1129 mutex_lock_nested(&ctx
->mutex
, nesting
);
1130 if (event
->ctx
!= ctx
) {
1131 mutex_unlock(&ctx
->mutex
);
1139 static inline struct perf_event_context
*
1140 perf_event_ctx_lock(struct perf_event
*event
)
1142 return perf_event_ctx_lock_nested(event
, 0);
1145 static void perf_event_ctx_unlock(struct perf_event
*event
,
1146 struct perf_event_context
*ctx
)
1148 mutex_unlock(&ctx
->mutex
);
1153 * This must be done under the ctx->lock, such as to serialize against
1154 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1155 * calling scheduler related locks and ctx->lock nests inside those.
1157 static __must_check
struct perf_event_context
*
1158 unclone_ctx(struct perf_event_context
*ctx
)
1160 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1162 lockdep_assert_held(&ctx
->lock
);
1165 ctx
->parent_ctx
= NULL
;
1171 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1174 * only top level events have the pid namespace they were created in
1177 event
= event
->parent
;
1179 return task_tgid_nr_ns(p
, event
->ns
);
1182 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1185 * only top level events have the pid namespace they were created in
1188 event
= event
->parent
;
1190 return task_pid_nr_ns(p
, event
->ns
);
1194 * If we inherit events we want to return the parent event id
1197 static u64
primary_event_id(struct perf_event
*event
)
1202 id
= event
->parent
->id
;
1208 * Get the perf_event_context for a task and lock it.
1210 * This has to cope with with the fact that until it is locked,
1211 * the context could get moved to another task.
1213 static struct perf_event_context
*
1214 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1216 struct perf_event_context
*ctx
;
1220 * One of the few rules of preemptible RCU is that one cannot do
1221 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1222 * part of the read side critical section was irqs-enabled -- see
1223 * rcu_read_unlock_special().
1225 * Since ctx->lock nests under rq->lock we must ensure the entire read
1226 * side critical section has interrupts disabled.
1228 local_irq_save(*flags
);
1230 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1233 * If this context is a clone of another, it might
1234 * get swapped for another underneath us by
1235 * perf_event_task_sched_out, though the
1236 * rcu_read_lock() protects us from any context
1237 * getting freed. Lock the context and check if it
1238 * got swapped before we could get the lock, and retry
1239 * if so. If we locked the right context, then it
1240 * can't get swapped on us any more.
1242 raw_spin_lock(&ctx
->lock
);
1243 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1244 raw_spin_unlock(&ctx
->lock
);
1246 local_irq_restore(*flags
);
1250 if (ctx
->task
== TASK_TOMBSTONE
||
1251 !atomic_inc_not_zero(&ctx
->refcount
)) {
1252 raw_spin_unlock(&ctx
->lock
);
1255 WARN_ON_ONCE(ctx
->task
!= task
);
1260 local_irq_restore(*flags
);
1265 * Get the context for a task and increment its pin_count so it
1266 * can't get swapped to another task. This also increments its
1267 * reference count so that the context can't get freed.
1269 static struct perf_event_context
*
1270 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1272 struct perf_event_context
*ctx
;
1273 unsigned long flags
;
1275 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1278 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1283 static void perf_unpin_context(struct perf_event_context
*ctx
)
1285 unsigned long flags
;
1287 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1289 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1293 * Update the record of the current time in a context.
1295 static void update_context_time(struct perf_event_context
*ctx
)
1297 u64 now
= perf_clock();
1299 ctx
->time
+= now
- ctx
->timestamp
;
1300 ctx
->timestamp
= now
;
1303 static u64
perf_event_time(struct perf_event
*event
)
1305 struct perf_event_context
*ctx
= event
->ctx
;
1307 if (is_cgroup_event(event
))
1308 return perf_cgroup_event_time(event
);
1310 return ctx
? ctx
->time
: 0;
1314 * Update the total_time_enabled and total_time_running fields for a event.
1316 static void update_event_times(struct perf_event
*event
)
1318 struct perf_event_context
*ctx
= event
->ctx
;
1321 lockdep_assert_held(&ctx
->lock
);
1323 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1324 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1328 * in cgroup mode, time_enabled represents
1329 * the time the event was enabled AND active
1330 * tasks were in the monitored cgroup. This is
1331 * independent of the activity of the context as
1332 * there may be a mix of cgroup and non-cgroup events.
1334 * That is why we treat cgroup events differently
1337 if (is_cgroup_event(event
))
1338 run_end
= perf_cgroup_event_time(event
);
1339 else if (ctx
->is_active
)
1340 run_end
= ctx
->time
;
1342 run_end
= event
->tstamp_stopped
;
1344 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1346 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1347 run_end
= event
->tstamp_stopped
;
1349 run_end
= perf_event_time(event
);
1351 event
->total_time_running
= run_end
- event
->tstamp_running
;
1356 * Update total_time_enabled and total_time_running for all events in a group.
1358 static void update_group_times(struct perf_event
*leader
)
1360 struct perf_event
*event
;
1362 update_event_times(leader
);
1363 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1364 update_event_times(event
);
1367 static struct list_head
*
1368 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1370 if (event
->attr
.pinned
)
1371 return &ctx
->pinned_groups
;
1373 return &ctx
->flexible_groups
;
1377 * Add a event from the lists for its context.
1378 * Must be called with ctx->mutex and ctx->lock held.
1381 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1383 lockdep_assert_held(&ctx
->lock
);
1385 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1386 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1389 * If we're a stand alone event or group leader, we go to the context
1390 * list, group events are kept attached to the group so that
1391 * perf_group_detach can, at all times, locate all siblings.
1393 if (event
->group_leader
== event
) {
1394 struct list_head
*list
;
1396 if (is_software_event(event
))
1397 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1399 list
= ctx_group_list(event
, ctx
);
1400 list_add_tail(&event
->group_entry
, list
);
1403 if (is_cgroup_event(event
))
1406 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1408 if (event
->attr
.inherit_stat
)
1415 * Initialize event state based on the perf_event_attr::disabled.
1417 static inline void perf_event__state_init(struct perf_event
*event
)
1419 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1420 PERF_EVENT_STATE_INACTIVE
;
1423 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1425 int entry
= sizeof(u64
); /* value */
1429 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1430 size
+= sizeof(u64
);
1432 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1433 size
+= sizeof(u64
);
1435 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1436 entry
+= sizeof(u64
);
1438 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1440 size
+= sizeof(u64
);
1444 event
->read_size
= size
;
1447 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1449 struct perf_sample_data
*data
;
1452 if (sample_type
& PERF_SAMPLE_IP
)
1453 size
+= sizeof(data
->ip
);
1455 if (sample_type
& PERF_SAMPLE_ADDR
)
1456 size
+= sizeof(data
->addr
);
1458 if (sample_type
& PERF_SAMPLE_PERIOD
)
1459 size
+= sizeof(data
->period
);
1461 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1462 size
+= sizeof(data
->weight
);
1464 if (sample_type
& PERF_SAMPLE_READ
)
1465 size
+= event
->read_size
;
1467 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1468 size
+= sizeof(data
->data_src
.val
);
1470 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1471 size
+= sizeof(data
->txn
);
1473 event
->header_size
= size
;
1477 * Called at perf_event creation and when events are attached/detached from a
1480 static void perf_event__header_size(struct perf_event
*event
)
1482 __perf_event_read_size(event
,
1483 event
->group_leader
->nr_siblings
);
1484 __perf_event_header_size(event
, event
->attr
.sample_type
);
1487 static void perf_event__id_header_size(struct perf_event
*event
)
1489 struct perf_sample_data
*data
;
1490 u64 sample_type
= event
->attr
.sample_type
;
1493 if (sample_type
& PERF_SAMPLE_TID
)
1494 size
+= sizeof(data
->tid_entry
);
1496 if (sample_type
& PERF_SAMPLE_TIME
)
1497 size
+= sizeof(data
->time
);
1499 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1500 size
+= sizeof(data
->id
);
1502 if (sample_type
& PERF_SAMPLE_ID
)
1503 size
+= sizeof(data
->id
);
1505 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1506 size
+= sizeof(data
->stream_id
);
1508 if (sample_type
& PERF_SAMPLE_CPU
)
1509 size
+= sizeof(data
->cpu_entry
);
1511 event
->id_header_size
= size
;
1514 static bool perf_event_validate_size(struct perf_event
*event
)
1517 * The values computed here will be over-written when we actually
1520 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1521 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1522 perf_event__id_header_size(event
);
1525 * Sum the lot; should not exceed the 64k limit we have on records.
1526 * Conservative limit to allow for callchains and other variable fields.
1528 if (event
->read_size
+ event
->header_size
+
1529 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1535 static void perf_group_attach(struct perf_event
*event
)
1537 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1540 * We can have double attach due to group movement in perf_event_open.
1542 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1545 event
->attach_state
|= PERF_ATTACH_GROUP
;
1547 if (group_leader
== event
)
1550 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1552 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1553 !is_software_event(event
))
1554 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1556 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1557 group_leader
->nr_siblings
++;
1559 perf_event__header_size(group_leader
);
1561 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1562 perf_event__header_size(pos
);
1566 * Remove a event from the lists for its context.
1567 * Must be called with ctx->mutex and ctx->lock held.
1570 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1572 struct perf_cpu_context
*cpuctx
;
1574 WARN_ON_ONCE(event
->ctx
!= ctx
);
1575 lockdep_assert_held(&ctx
->lock
);
1578 * We can have double detach due to exit/hot-unplug + close.
1580 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1583 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1585 if (is_cgroup_event(event
)) {
1588 * Because cgroup events are always per-cpu events, this will
1589 * always be called from the right CPU.
1591 cpuctx
= __get_cpu_context(ctx
);
1593 * If there are no more cgroup events then clear cgrp to avoid
1594 * stale pointer in update_cgrp_time_from_cpuctx().
1596 if (!ctx
->nr_cgroups
)
1597 cpuctx
->cgrp
= NULL
;
1601 if (event
->attr
.inherit_stat
)
1604 list_del_rcu(&event
->event_entry
);
1606 if (event
->group_leader
== event
)
1607 list_del_init(&event
->group_entry
);
1609 update_group_times(event
);
1612 * If event was in error state, then keep it
1613 * that way, otherwise bogus counts will be
1614 * returned on read(). The only way to get out
1615 * of error state is by explicit re-enabling
1618 if (event
->state
> PERF_EVENT_STATE_OFF
)
1619 event
->state
= PERF_EVENT_STATE_OFF
;
1624 static void perf_group_detach(struct perf_event
*event
)
1626 struct perf_event
*sibling
, *tmp
;
1627 struct list_head
*list
= NULL
;
1630 * We can have double detach due to exit/hot-unplug + close.
1632 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1635 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1638 * If this is a sibling, remove it from its group.
1640 if (event
->group_leader
!= event
) {
1641 list_del_init(&event
->group_entry
);
1642 event
->group_leader
->nr_siblings
--;
1646 if (!list_empty(&event
->group_entry
))
1647 list
= &event
->group_entry
;
1650 * If this was a group event with sibling events then
1651 * upgrade the siblings to singleton events by adding them
1652 * to whatever list we are on.
1654 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1656 list_move_tail(&sibling
->group_entry
, list
);
1657 sibling
->group_leader
= sibling
;
1659 /* Inherit group flags from the previous leader */
1660 sibling
->group_flags
= event
->group_flags
;
1662 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1666 perf_event__header_size(event
->group_leader
);
1668 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1669 perf_event__header_size(tmp
);
1672 static bool is_orphaned_event(struct perf_event
*event
)
1674 return event
->state
== PERF_EVENT_STATE_DEAD
;
1677 static inline int pmu_filter_match(struct perf_event
*event
)
1679 struct pmu
*pmu
= event
->pmu
;
1680 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1684 event_filter_match(struct perf_event
*event
)
1686 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1687 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1691 event_sched_out(struct perf_event
*event
,
1692 struct perf_cpu_context
*cpuctx
,
1693 struct perf_event_context
*ctx
)
1695 u64 tstamp
= perf_event_time(event
);
1698 WARN_ON_ONCE(event
->ctx
!= ctx
);
1699 lockdep_assert_held(&ctx
->lock
);
1702 * An event which could not be activated because of
1703 * filter mismatch still needs to have its timings
1704 * maintained, otherwise bogus information is return
1705 * via read() for time_enabled, time_running:
1707 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1708 && !event_filter_match(event
)) {
1709 delta
= tstamp
- event
->tstamp_stopped
;
1710 event
->tstamp_running
+= delta
;
1711 event
->tstamp_stopped
= tstamp
;
1714 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1717 perf_pmu_disable(event
->pmu
);
1719 event
->tstamp_stopped
= tstamp
;
1720 event
->pmu
->del(event
, 0);
1722 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1723 if (event
->pending_disable
) {
1724 event
->pending_disable
= 0;
1725 event
->state
= PERF_EVENT_STATE_OFF
;
1728 if (!is_software_event(event
))
1729 cpuctx
->active_oncpu
--;
1730 if (!--ctx
->nr_active
)
1731 perf_event_ctx_deactivate(ctx
);
1732 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1734 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1735 cpuctx
->exclusive
= 0;
1737 perf_pmu_enable(event
->pmu
);
1741 group_sched_out(struct perf_event
*group_event
,
1742 struct perf_cpu_context
*cpuctx
,
1743 struct perf_event_context
*ctx
)
1745 struct perf_event
*event
;
1746 int state
= group_event
->state
;
1748 event_sched_out(group_event
, cpuctx
, ctx
);
1751 * Schedule out siblings (if any):
1753 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1754 event_sched_out(event
, cpuctx
, ctx
);
1756 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1757 cpuctx
->exclusive
= 0;
1760 #define DETACH_GROUP 0x01UL
1763 * Cross CPU call to remove a performance event
1765 * We disable the event on the hardware level first. After that we
1766 * remove it from the context list.
1769 __perf_remove_from_context(struct perf_event
*event
,
1770 struct perf_cpu_context
*cpuctx
,
1771 struct perf_event_context
*ctx
,
1774 unsigned long flags
= (unsigned long)info
;
1776 event_sched_out(event
, cpuctx
, ctx
);
1777 if (flags
& DETACH_GROUP
)
1778 perf_group_detach(event
);
1779 list_del_event(event
, ctx
);
1781 if (!ctx
->nr_events
&& ctx
->is_active
) {
1784 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1785 cpuctx
->task_ctx
= NULL
;
1791 * Remove the event from a task's (or a CPU's) list of events.
1793 * If event->ctx is a cloned context, callers must make sure that
1794 * every task struct that event->ctx->task could possibly point to
1795 * remains valid. This is OK when called from perf_release since
1796 * that only calls us on the top-level context, which can't be a clone.
1797 * When called from perf_event_exit_task, it's OK because the
1798 * context has been detached from its task.
1800 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1802 lockdep_assert_held(&event
->ctx
->mutex
);
1804 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1808 * Cross CPU call to disable a performance event
1810 static void __perf_event_disable(struct perf_event
*event
,
1811 struct perf_cpu_context
*cpuctx
,
1812 struct perf_event_context
*ctx
,
1815 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1818 update_context_time(ctx
);
1819 update_cgrp_time_from_event(event
);
1820 update_group_times(event
);
1821 if (event
== event
->group_leader
)
1822 group_sched_out(event
, cpuctx
, ctx
);
1824 event_sched_out(event
, cpuctx
, ctx
);
1825 event
->state
= PERF_EVENT_STATE_OFF
;
1831 * If event->ctx is a cloned context, callers must make sure that
1832 * every task struct that event->ctx->task could possibly point to
1833 * remains valid. This condition is satisifed when called through
1834 * perf_event_for_each_child or perf_event_for_each because they
1835 * hold the top-level event's child_mutex, so any descendant that
1836 * goes to exit will block in perf_event_exit_event().
1838 * When called from perf_pending_event it's OK because event->ctx
1839 * is the current context on this CPU and preemption is disabled,
1840 * hence we can't get into perf_event_task_sched_out for this context.
1842 static void _perf_event_disable(struct perf_event
*event
)
1844 struct perf_event_context
*ctx
= event
->ctx
;
1846 raw_spin_lock_irq(&ctx
->lock
);
1847 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1848 raw_spin_unlock_irq(&ctx
->lock
);
1851 raw_spin_unlock_irq(&ctx
->lock
);
1853 event_function_call(event
, __perf_event_disable
, NULL
);
1856 void perf_event_disable_local(struct perf_event
*event
)
1858 event_function_local(event
, __perf_event_disable
, NULL
);
1862 * Strictly speaking kernel users cannot create groups and therefore this
1863 * interface does not need the perf_event_ctx_lock() magic.
1865 void perf_event_disable(struct perf_event
*event
)
1867 struct perf_event_context
*ctx
;
1869 ctx
= perf_event_ctx_lock(event
);
1870 _perf_event_disable(event
);
1871 perf_event_ctx_unlock(event
, ctx
);
1873 EXPORT_SYMBOL_GPL(perf_event_disable
);
1875 static void perf_set_shadow_time(struct perf_event
*event
,
1876 struct perf_event_context
*ctx
,
1880 * use the correct time source for the time snapshot
1882 * We could get by without this by leveraging the
1883 * fact that to get to this function, the caller
1884 * has most likely already called update_context_time()
1885 * and update_cgrp_time_xx() and thus both timestamp
1886 * are identical (or very close). Given that tstamp is,
1887 * already adjusted for cgroup, we could say that:
1888 * tstamp - ctx->timestamp
1890 * tstamp - cgrp->timestamp.
1892 * Then, in perf_output_read(), the calculation would
1893 * work with no changes because:
1894 * - event is guaranteed scheduled in
1895 * - no scheduled out in between
1896 * - thus the timestamp would be the same
1898 * But this is a bit hairy.
1900 * So instead, we have an explicit cgroup call to remain
1901 * within the time time source all along. We believe it
1902 * is cleaner and simpler to understand.
1904 if (is_cgroup_event(event
))
1905 perf_cgroup_set_shadow_time(event
, tstamp
);
1907 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1910 #define MAX_INTERRUPTS (~0ULL)
1912 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1913 static void perf_log_itrace_start(struct perf_event
*event
);
1916 event_sched_in(struct perf_event
*event
,
1917 struct perf_cpu_context
*cpuctx
,
1918 struct perf_event_context
*ctx
)
1920 u64 tstamp
= perf_event_time(event
);
1923 lockdep_assert_held(&ctx
->lock
);
1925 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1928 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1929 event
->oncpu
= smp_processor_id();
1932 * Unthrottle events, since we scheduled we might have missed several
1933 * ticks already, also for a heavily scheduling task there is little
1934 * guarantee it'll get a tick in a timely manner.
1936 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1937 perf_log_throttle(event
, 1);
1938 event
->hw
.interrupts
= 0;
1942 * The new state must be visible before we turn it on in the hardware:
1946 perf_pmu_disable(event
->pmu
);
1948 perf_set_shadow_time(event
, ctx
, tstamp
);
1950 perf_log_itrace_start(event
);
1952 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1953 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1959 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1961 if (!is_software_event(event
))
1962 cpuctx
->active_oncpu
++;
1963 if (!ctx
->nr_active
++)
1964 perf_event_ctx_activate(ctx
);
1965 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1968 if (event
->attr
.exclusive
)
1969 cpuctx
->exclusive
= 1;
1972 perf_pmu_enable(event
->pmu
);
1978 group_sched_in(struct perf_event
*group_event
,
1979 struct perf_cpu_context
*cpuctx
,
1980 struct perf_event_context
*ctx
)
1982 struct perf_event
*event
, *partial_group
= NULL
;
1983 struct pmu
*pmu
= ctx
->pmu
;
1984 u64 now
= ctx
->time
;
1985 bool simulate
= false;
1987 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1990 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
1992 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1993 pmu
->cancel_txn(pmu
);
1994 perf_mux_hrtimer_restart(cpuctx
);
1999 * Schedule in siblings as one group (if any):
2001 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2002 if (event_sched_in(event
, cpuctx
, ctx
)) {
2003 partial_group
= event
;
2008 if (!pmu
->commit_txn(pmu
))
2013 * Groups can be scheduled in as one unit only, so undo any
2014 * partial group before returning:
2015 * The events up to the failed event are scheduled out normally,
2016 * tstamp_stopped will be updated.
2018 * The failed events and the remaining siblings need to have
2019 * their timings updated as if they had gone thru event_sched_in()
2020 * and event_sched_out(). This is required to get consistent timings
2021 * across the group. This also takes care of the case where the group
2022 * could never be scheduled by ensuring tstamp_stopped is set to mark
2023 * the time the event was actually stopped, such that time delta
2024 * calculation in update_event_times() is correct.
2026 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2027 if (event
== partial_group
)
2031 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2032 event
->tstamp_stopped
= now
;
2034 event_sched_out(event
, cpuctx
, ctx
);
2037 event_sched_out(group_event
, cpuctx
, ctx
);
2039 pmu
->cancel_txn(pmu
);
2041 perf_mux_hrtimer_restart(cpuctx
);
2047 * Work out whether we can put this event group on the CPU now.
2049 static int group_can_go_on(struct perf_event
*event
,
2050 struct perf_cpu_context
*cpuctx
,
2054 * Groups consisting entirely of software events can always go on.
2056 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2059 * If an exclusive group is already on, no other hardware
2062 if (cpuctx
->exclusive
)
2065 * If this group is exclusive and there are already
2066 * events on the CPU, it can't go on.
2068 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2071 * Otherwise, try to add it if all previous groups were able
2077 static void add_event_to_ctx(struct perf_event
*event
,
2078 struct perf_event_context
*ctx
)
2080 u64 tstamp
= perf_event_time(event
);
2082 list_add_event(event
, ctx
);
2083 perf_group_attach(event
);
2084 event
->tstamp_enabled
= tstamp
;
2085 event
->tstamp_running
= tstamp
;
2086 event
->tstamp_stopped
= tstamp
;
2089 static void ctx_sched_out(struct perf_event_context
*ctx
,
2090 struct perf_cpu_context
*cpuctx
,
2091 enum event_type_t event_type
);
2093 ctx_sched_in(struct perf_event_context
*ctx
,
2094 struct perf_cpu_context
*cpuctx
,
2095 enum event_type_t event_type
,
2096 struct task_struct
*task
);
2098 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2099 struct perf_event_context
*ctx
)
2101 if (!cpuctx
->task_ctx
)
2104 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2107 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2110 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2111 struct perf_event_context
*ctx
,
2112 struct task_struct
*task
)
2114 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2116 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2117 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2119 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2122 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2123 struct perf_event_context
*task_ctx
)
2125 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2127 task_ctx_sched_out(cpuctx
, task_ctx
);
2128 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2129 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2130 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2134 * Cross CPU call to install and enable a performance event
2136 * Very similar to remote_function() + event_function() but cannot assume that
2137 * things like ctx->is_active and cpuctx->task_ctx are set.
2139 static int __perf_install_in_context(void *info
)
2141 struct perf_event
*event
= info
;
2142 struct perf_event_context
*ctx
= event
->ctx
;
2143 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2144 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2145 bool activate
= true;
2148 raw_spin_lock(&cpuctx
->ctx
.lock
);
2150 raw_spin_lock(&ctx
->lock
);
2153 /* If we're on the wrong CPU, try again */
2154 if (task_cpu(ctx
->task
) != smp_processor_id()) {
2160 * If we're on the right CPU, see if the task we target is
2161 * current, if not we don't have to activate the ctx, a future
2162 * context switch will do that for us.
2164 if (ctx
->task
!= current
)
2167 WARN_ON_ONCE(cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2169 } else if (task_ctx
) {
2170 raw_spin_lock(&task_ctx
->lock
);
2174 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2175 add_event_to_ctx(event
, ctx
);
2176 ctx_resched(cpuctx
, task_ctx
);
2178 add_event_to_ctx(event
, ctx
);
2182 perf_ctx_unlock(cpuctx
, task_ctx
);
2188 * Attach a performance event to a context.
2190 * Very similar to event_function_call, see comment there.
2193 perf_install_in_context(struct perf_event_context
*ctx
,
2194 struct perf_event
*event
,
2197 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2199 lockdep_assert_held(&ctx
->mutex
);
2202 if (event
->cpu
!= -1)
2206 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2211 * Should not happen, we validate the ctx is still alive before calling.
2213 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2217 * Installing events is tricky because we cannot rely on ctx->is_active
2218 * to be set in case this is the nr_events 0 -> 1 transition.
2222 * Cannot use task_function_call() because we need to run on the task's
2223 * CPU regardless of whether its current or not.
2225 if (!cpu_function_call(task_cpu(task
), __perf_install_in_context
, event
))
2228 raw_spin_lock_irq(&ctx
->lock
);
2230 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2232 * Cannot happen because we already checked above (which also
2233 * cannot happen), and we hold ctx->mutex, which serializes us
2234 * against perf_event_exit_task_context().
2236 raw_spin_unlock_irq(&ctx
->lock
);
2239 raw_spin_unlock_irq(&ctx
->lock
);
2241 * Since !ctx->is_active doesn't mean anything, we must IPI
2248 * Put a event into inactive state and update time fields.
2249 * Enabling the leader of a group effectively enables all
2250 * the group members that aren't explicitly disabled, so we
2251 * have to update their ->tstamp_enabled also.
2252 * Note: this works for group members as well as group leaders
2253 * since the non-leader members' sibling_lists will be empty.
2255 static void __perf_event_mark_enabled(struct perf_event
*event
)
2257 struct perf_event
*sub
;
2258 u64 tstamp
= perf_event_time(event
);
2260 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2261 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2262 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2263 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2264 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2269 * Cross CPU call to enable a performance event
2271 static void __perf_event_enable(struct perf_event
*event
,
2272 struct perf_cpu_context
*cpuctx
,
2273 struct perf_event_context
*ctx
,
2276 struct perf_event
*leader
= event
->group_leader
;
2277 struct perf_event_context
*task_ctx
;
2279 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2280 event
->state
<= PERF_EVENT_STATE_ERROR
)
2284 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2286 __perf_event_mark_enabled(event
);
2288 if (!ctx
->is_active
)
2291 if (!event_filter_match(event
)) {
2292 if (is_cgroup_event(event
))
2293 perf_cgroup_defer_enabled(event
);
2294 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2299 * If the event is in a group and isn't the group leader,
2300 * then don't put it on unless the group is on.
2302 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2303 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2307 task_ctx
= cpuctx
->task_ctx
;
2309 WARN_ON_ONCE(task_ctx
!= ctx
);
2311 ctx_resched(cpuctx
, task_ctx
);
2317 * If event->ctx is a cloned context, callers must make sure that
2318 * every task struct that event->ctx->task could possibly point to
2319 * remains valid. This condition is satisfied when called through
2320 * perf_event_for_each_child or perf_event_for_each as described
2321 * for perf_event_disable.
2323 static void _perf_event_enable(struct perf_event
*event
)
2325 struct perf_event_context
*ctx
= event
->ctx
;
2327 raw_spin_lock_irq(&ctx
->lock
);
2328 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2329 event
->state
< PERF_EVENT_STATE_ERROR
) {
2330 raw_spin_unlock_irq(&ctx
->lock
);
2335 * If the event is in error state, clear that first.
2337 * That way, if we see the event in error state below, we know that it
2338 * has gone back into error state, as distinct from the task having
2339 * been scheduled away before the cross-call arrived.
2341 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2342 event
->state
= PERF_EVENT_STATE_OFF
;
2343 raw_spin_unlock_irq(&ctx
->lock
);
2345 event_function_call(event
, __perf_event_enable
, NULL
);
2349 * See perf_event_disable();
2351 void perf_event_enable(struct perf_event
*event
)
2353 struct perf_event_context
*ctx
;
2355 ctx
= perf_event_ctx_lock(event
);
2356 _perf_event_enable(event
);
2357 perf_event_ctx_unlock(event
, ctx
);
2359 EXPORT_SYMBOL_GPL(perf_event_enable
);
2361 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2364 * not supported on inherited events
2366 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2369 atomic_add(refresh
, &event
->event_limit
);
2370 _perf_event_enable(event
);
2376 * See perf_event_disable()
2378 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2380 struct perf_event_context
*ctx
;
2383 ctx
= perf_event_ctx_lock(event
);
2384 ret
= _perf_event_refresh(event
, refresh
);
2385 perf_event_ctx_unlock(event
, ctx
);
2389 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2391 static void ctx_sched_out(struct perf_event_context
*ctx
,
2392 struct perf_cpu_context
*cpuctx
,
2393 enum event_type_t event_type
)
2395 int is_active
= ctx
->is_active
;
2396 struct perf_event
*event
;
2398 lockdep_assert_held(&ctx
->lock
);
2400 if (likely(!ctx
->nr_events
)) {
2402 * See __perf_remove_from_context().
2404 WARN_ON_ONCE(ctx
->is_active
);
2406 WARN_ON_ONCE(cpuctx
->task_ctx
);
2410 ctx
->is_active
&= ~event_type
;
2411 if (!(ctx
->is_active
& EVENT_ALL
))
2415 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2416 if (!ctx
->is_active
)
2417 cpuctx
->task_ctx
= NULL
;
2420 is_active
^= ctx
->is_active
; /* changed bits */
2422 if (is_active
& EVENT_TIME
) {
2423 /* update (and stop) ctx time */
2424 update_context_time(ctx
);
2425 update_cgrp_time_from_cpuctx(cpuctx
);
2428 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2431 perf_pmu_disable(ctx
->pmu
);
2432 if (is_active
& EVENT_PINNED
) {
2433 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2434 group_sched_out(event
, cpuctx
, ctx
);
2437 if (is_active
& EVENT_FLEXIBLE
) {
2438 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2439 group_sched_out(event
, cpuctx
, ctx
);
2441 perf_pmu_enable(ctx
->pmu
);
2445 * Test whether two contexts are equivalent, i.e. whether they have both been
2446 * cloned from the same version of the same context.
2448 * Equivalence is measured using a generation number in the context that is
2449 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2450 * and list_del_event().
2452 static int context_equiv(struct perf_event_context
*ctx1
,
2453 struct perf_event_context
*ctx2
)
2455 lockdep_assert_held(&ctx1
->lock
);
2456 lockdep_assert_held(&ctx2
->lock
);
2458 /* Pinning disables the swap optimization */
2459 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2462 /* If ctx1 is the parent of ctx2 */
2463 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2466 /* If ctx2 is the parent of ctx1 */
2467 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2471 * If ctx1 and ctx2 have the same parent; we flatten the parent
2472 * hierarchy, see perf_event_init_context().
2474 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2475 ctx1
->parent_gen
== ctx2
->parent_gen
)
2482 static void __perf_event_sync_stat(struct perf_event
*event
,
2483 struct perf_event
*next_event
)
2487 if (!event
->attr
.inherit_stat
)
2491 * Update the event value, we cannot use perf_event_read()
2492 * because we're in the middle of a context switch and have IRQs
2493 * disabled, which upsets smp_call_function_single(), however
2494 * we know the event must be on the current CPU, therefore we
2495 * don't need to use it.
2497 switch (event
->state
) {
2498 case PERF_EVENT_STATE_ACTIVE
:
2499 event
->pmu
->read(event
);
2502 case PERF_EVENT_STATE_INACTIVE
:
2503 update_event_times(event
);
2511 * In order to keep per-task stats reliable we need to flip the event
2512 * values when we flip the contexts.
2514 value
= local64_read(&next_event
->count
);
2515 value
= local64_xchg(&event
->count
, value
);
2516 local64_set(&next_event
->count
, value
);
2518 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2519 swap(event
->total_time_running
, next_event
->total_time_running
);
2522 * Since we swizzled the values, update the user visible data too.
2524 perf_event_update_userpage(event
);
2525 perf_event_update_userpage(next_event
);
2528 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2529 struct perf_event_context
*next_ctx
)
2531 struct perf_event
*event
, *next_event
;
2536 update_context_time(ctx
);
2538 event
= list_first_entry(&ctx
->event_list
,
2539 struct perf_event
, event_entry
);
2541 next_event
= list_first_entry(&next_ctx
->event_list
,
2542 struct perf_event
, event_entry
);
2544 while (&event
->event_entry
!= &ctx
->event_list
&&
2545 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2547 __perf_event_sync_stat(event
, next_event
);
2549 event
= list_next_entry(event
, event_entry
);
2550 next_event
= list_next_entry(next_event
, event_entry
);
2554 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2555 struct task_struct
*next
)
2557 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2558 struct perf_event_context
*next_ctx
;
2559 struct perf_event_context
*parent
, *next_parent
;
2560 struct perf_cpu_context
*cpuctx
;
2566 cpuctx
= __get_cpu_context(ctx
);
2567 if (!cpuctx
->task_ctx
)
2571 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2575 parent
= rcu_dereference(ctx
->parent_ctx
);
2576 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2578 /* If neither context have a parent context; they cannot be clones. */
2579 if (!parent
&& !next_parent
)
2582 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2584 * Looks like the two contexts are clones, so we might be
2585 * able to optimize the context switch. We lock both
2586 * contexts and check that they are clones under the
2587 * lock (including re-checking that neither has been
2588 * uncloned in the meantime). It doesn't matter which
2589 * order we take the locks because no other cpu could
2590 * be trying to lock both of these tasks.
2592 raw_spin_lock(&ctx
->lock
);
2593 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2594 if (context_equiv(ctx
, next_ctx
)) {
2595 WRITE_ONCE(ctx
->task
, next
);
2596 WRITE_ONCE(next_ctx
->task
, task
);
2598 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2601 * RCU_INIT_POINTER here is safe because we've not
2602 * modified the ctx and the above modification of
2603 * ctx->task and ctx->task_ctx_data are immaterial
2604 * since those values are always verified under
2605 * ctx->lock which we're now holding.
2607 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2608 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2612 perf_event_sync_stat(ctx
, next_ctx
);
2614 raw_spin_unlock(&next_ctx
->lock
);
2615 raw_spin_unlock(&ctx
->lock
);
2621 raw_spin_lock(&ctx
->lock
);
2622 task_ctx_sched_out(cpuctx
, ctx
);
2623 raw_spin_unlock(&ctx
->lock
);
2627 void perf_sched_cb_dec(struct pmu
*pmu
)
2629 this_cpu_dec(perf_sched_cb_usages
);
2632 void perf_sched_cb_inc(struct pmu
*pmu
)
2634 this_cpu_inc(perf_sched_cb_usages
);
2638 * This function provides the context switch callback to the lower code
2639 * layer. It is invoked ONLY when the context switch callback is enabled.
2641 static void perf_pmu_sched_task(struct task_struct
*prev
,
2642 struct task_struct
*next
,
2645 struct perf_cpu_context
*cpuctx
;
2647 unsigned long flags
;
2652 local_irq_save(flags
);
2656 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2657 if (pmu
->sched_task
) {
2658 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2660 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2662 perf_pmu_disable(pmu
);
2664 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2666 perf_pmu_enable(pmu
);
2668 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2674 local_irq_restore(flags
);
2677 static void perf_event_switch(struct task_struct
*task
,
2678 struct task_struct
*next_prev
, bool sched_in
);
2680 #define for_each_task_context_nr(ctxn) \
2681 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2684 * Called from scheduler to remove the events of the current task,
2685 * with interrupts disabled.
2687 * We stop each event and update the event value in event->count.
2689 * This does not protect us against NMI, but disable()
2690 * sets the disabled bit in the control field of event _before_
2691 * accessing the event control register. If a NMI hits, then it will
2692 * not restart the event.
2694 void __perf_event_task_sched_out(struct task_struct
*task
,
2695 struct task_struct
*next
)
2699 if (__this_cpu_read(perf_sched_cb_usages
))
2700 perf_pmu_sched_task(task
, next
, false);
2702 if (atomic_read(&nr_switch_events
))
2703 perf_event_switch(task
, next
, false);
2705 for_each_task_context_nr(ctxn
)
2706 perf_event_context_sched_out(task
, ctxn
, next
);
2709 * if cgroup events exist on this CPU, then we need
2710 * to check if we have to switch out PMU state.
2711 * cgroup event are system-wide mode only
2713 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2714 perf_cgroup_sched_out(task
, next
);
2718 * Called with IRQs disabled
2720 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2721 enum event_type_t event_type
)
2723 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2727 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2728 struct perf_cpu_context
*cpuctx
)
2730 struct perf_event
*event
;
2732 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2733 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2735 if (!event_filter_match(event
))
2738 /* may need to reset tstamp_enabled */
2739 if (is_cgroup_event(event
))
2740 perf_cgroup_mark_enabled(event
, ctx
);
2742 if (group_can_go_on(event
, cpuctx
, 1))
2743 group_sched_in(event
, cpuctx
, ctx
);
2746 * If this pinned group hasn't been scheduled,
2747 * put it in error state.
2749 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2750 update_group_times(event
);
2751 event
->state
= PERF_EVENT_STATE_ERROR
;
2757 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2758 struct perf_cpu_context
*cpuctx
)
2760 struct perf_event
*event
;
2763 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2764 /* Ignore events in OFF or ERROR state */
2765 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2768 * Listen to the 'cpu' scheduling filter constraint
2771 if (!event_filter_match(event
))
2774 /* may need to reset tstamp_enabled */
2775 if (is_cgroup_event(event
))
2776 perf_cgroup_mark_enabled(event
, ctx
);
2778 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2779 if (group_sched_in(event
, cpuctx
, ctx
))
2786 ctx_sched_in(struct perf_event_context
*ctx
,
2787 struct perf_cpu_context
*cpuctx
,
2788 enum event_type_t event_type
,
2789 struct task_struct
*task
)
2791 int is_active
= ctx
->is_active
;
2794 lockdep_assert_held(&ctx
->lock
);
2796 if (likely(!ctx
->nr_events
))
2799 ctx
->is_active
|= (event_type
| EVENT_TIME
);
2802 cpuctx
->task_ctx
= ctx
;
2804 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2807 is_active
^= ctx
->is_active
; /* changed bits */
2809 if (is_active
& EVENT_TIME
) {
2810 /* start ctx time */
2812 ctx
->timestamp
= now
;
2813 perf_cgroup_set_timestamp(task
, ctx
);
2817 * First go through the list and put on any pinned groups
2818 * in order to give them the best chance of going on.
2820 if (is_active
& EVENT_PINNED
)
2821 ctx_pinned_sched_in(ctx
, cpuctx
);
2823 /* Then walk through the lower prio flexible groups */
2824 if (is_active
& EVENT_FLEXIBLE
)
2825 ctx_flexible_sched_in(ctx
, cpuctx
);
2828 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2829 enum event_type_t event_type
,
2830 struct task_struct
*task
)
2832 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2834 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2837 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2838 struct task_struct
*task
)
2840 struct perf_cpu_context
*cpuctx
;
2842 cpuctx
= __get_cpu_context(ctx
);
2843 if (cpuctx
->task_ctx
== ctx
)
2846 perf_ctx_lock(cpuctx
, ctx
);
2847 perf_pmu_disable(ctx
->pmu
);
2849 * We want to keep the following priority order:
2850 * cpu pinned (that don't need to move), task pinned,
2851 * cpu flexible, task flexible.
2853 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2854 perf_event_sched_in(cpuctx
, ctx
, task
);
2855 perf_pmu_enable(ctx
->pmu
);
2856 perf_ctx_unlock(cpuctx
, ctx
);
2860 * Called from scheduler to add the events of the current task
2861 * with interrupts disabled.
2863 * We restore the event value and then enable it.
2865 * This does not protect us against NMI, but enable()
2866 * sets the enabled bit in the control field of event _before_
2867 * accessing the event control register. If a NMI hits, then it will
2868 * keep the event running.
2870 void __perf_event_task_sched_in(struct task_struct
*prev
,
2871 struct task_struct
*task
)
2873 struct perf_event_context
*ctx
;
2877 * If cgroup events exist on this CPU, then we need to check if we have
2878 * to switch in PMU state; cgroup event are system-wide mode only.
2880 * Since cgroup events are CPU events, we must schedule these in before
2881 * we schedule in the task events.
2883 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2884 perf_cgroup_sched_in(prev
, task
);
2886 for_each_task_context_nr(ctxn
) {
2887 ctx
= task
->perf_event_ctxp
[ctxn
];
2891 perf_event_context_sched_in(ctx
, task
);
2894 if (atomic_read(&nr_switch_events
))
2895 perf_event_switch(task
, prev
, true);
2897 if (__this_cpu_read(perf_sched_cb_usages
))
2898 perf_pmu_sched_task(prev
, task
, true);
2901 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2903 u64 frequency
= event
->attr
.sample_freq
;
2904 u64 sec
= NSEC_PER_SEC
;
2905 u64 divisor
, dividend
;
2907 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2909 count_fls
= fls64(count
);
2910 nsec_fls
= fls64(nsec
);
2911 frequency_fls
= fls64(frequency
);
2915 * We got @count in @nsec, with a target of sample_freq HZ
2916 * the target period becomes:
2919 * period = -------------------
2920 * @nsec * sample_freq
2925 * Reduce accuracy by one bit such that @a and @b converge
2926 * to a similar magnitude.
2928 #define REDUCE_FLS(a, b) \
2930 if (a##_fls > b##_fls) { \
2940 * Reduce accuracy until either term fits in a u64, then proceed with
2941 * the other, so that finally we can do a u64/u64 division.
2943 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2944 REDUCE_FLS(nsec
, frequency
);
2945 REDUCE_FLS(sec
, count
);
2948 if (count_fls
+ sec_fls
> 64) {
2949 divisor
= nsec
* frequency
;
2951 while (count_fls
+ sec_fls
> 64) {
2952 REDUCE_FLS(count
, sec
);
2956 dividend
= count
* sec
;
2958 dividend
= count
* sec
;
2960 while (nsec_fls
+ frequency_fls
> 64) {
2961 REDUCE_FLS(nsec
, frequency
);
2965 divisor
= nsec
* frequency
;
2971 return div64_u64(dividend
, divisor
);
2974 static DEFINE_PER_CPU(int, perf_throttled_count
);
2975 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2977 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2979 struct hw_perf_event
*hwc
= &event
->hw
;
2980 s64 period
, sample_period
;
2983 period
= perf_calculate_period(event
, nsec
, count
);
2985 delta
= (s64
)(period
- hwc
->sample_period
);
2986 delta
= (delta
+ 7) / 8; /* low pass filter */
2988 sample_period
= hwc
->sample_period
+ delta
;
2993 hwc
->sample_period
= sample_period
;
2995 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2997 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2999 local64_set(&hwc
->period_left
, 0);
3002 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3007 * combine freq adjustment with unthrottling to avoid two passes over the
3008 * events. At the same time, make sure, having freq events does not change
3009 * the rate of unthrottling as that would introduce bias.
3011 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3014 struct perf_event
*event
;
3015 struct hw_perf_event
*hwc
;
3016 u64 now
, period
= TICK_NSEC
;
3020 * only need to iterate over all events iff:
3021 * - context have events in frequency mode (needs freq adjust)
3022 * - there are events to unthrottle on this cpu
3024 if (!(ctx
->nr_freq
|| needs_unthr
))
3027 raw_spin_lock(&ctx
->lock
);
3028 perf_pmu_disable(ctx
->pmu
);
3030 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3031 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3034 if (!event_filter_match(event
))
3037 perf_pmu_disable(event
->pmu
);
3041 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3042 hwc
->interrupts
= 0;
3043 perf_log_throttle(event
, 1);
3044 event
->pmu
->start(event
, 0);
3047 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3051 * stop the event and update event->count
3053 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3055 now
= local64_read(&event
->count
);
3056 delta
= now
- hwc
->freq_count_stamp
;
3057 hwc
->freq_count_stamp
= now
;
3061 * reload only if value has changed
3062 * we have stopped the event so tell that
3063 * to perf_adjust_period() to avoid stopping it
3067 perf_adjust_period(event
, period
, delta
, false);
3069 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3071 perf_pmu_enable(event
->pmu
);
3074 perf_pmu_enable(ctx
->pmu
);
3075 raw_spin_unlock(&ctx
->lock
);
3079 * Round-robin a context's events:
3081 static void rotate_ctx(struct perf_event_context
*ctx
)
3084 * Rotate the first entry last of non-pinned groups. Rotation might be
3085 * disabled by the inheritance code.
3087 if (!ctx
->rotate_disable
)
3088 list_rotate_left(&ctx
->flexible_groups
);
3091 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3093 struct perf_event_context
*ctx
= NULL
;
3096 if (cpuctx
->ctx
.nr_events
) {
3097 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3101 ctx
= cpuctx
->task_ctx
;
3102 if (ctx
&& ctx
->nr_events
) {
3103 if (ctx
->nr_events
!= ctx
->nr_active
)
3110 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3111 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3113 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3115 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3117 rotate_ctx(&cpuctx
->ctx
);
3121 perf_event_sched_in(cpuctx
, ctx
, current
);
3123 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3124 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3130 void perf_event_task_tick(void)
3132 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3133 struct perf_event_context
*ctx
, *tmp
;
3136 WARN_ON(!irqs_disabled());
3138 __this_cpu_inc(perf_throttled_seq
);
3139 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3140 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3142 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3143 perf_adjust_freq_unthr_context(ctx
, throttled
);
3146 static int event_enable_on_exec(struct perf_event
*event
,
3147 struct perf_event_context
*ctx
)
3149 if (!event
->attr
.enable_on_exec
)
3152 event
->attr
.enable_on_exec
= 0;
3153 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3156 __perf_event_mark_enabled(event
);
3162 * Enable all of a task's events that have been marked enable-on-exec.
3163 * This expects task == current.
3165 static void perf_event_enable_on_exec(int ctxn
)
3167 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3168 struct perf_cpu_context
*cpuctx
;
3169 struct perf_event
*event
;
3170 unsigned long flags
;
3173 local_irq_save(flags
);
3174 ctx
= current
->perf_event_ctxp
[ctxn
];
3175 if (!ctx
|| !ctx
->nr_events
)
3178 cpuctx
= __get_cpu_context(ctx
);
3179 perf_ctx_lock(cpuctx
, ctx
);
3180 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3181 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
3182 enabled
|= event_enable_on_exec(event
, ctx
);
3185 * Unclone and reschedule this context if we enabled any event.
3188 clone_ctx
= unclone_ctx(ctx
);
3189 ctx_resched(cpuctx
, ctx
);
3191 perf_ctx_unlock(cpuctx
, ctx
);
3194 local_irq_restore(flags
);
3200 void perf_event_exec(void)
3205 for_each_task_context_nr(ctxn
)
3206 perf_event_enable_on_exec(ctxn
);
3210 struct perf_read_data
{
3211 struct perf_event
*event
;
3217 * Cross CPU call to read the hardware event
3219 static void __perf_event_read(void *info
)
3221 struct perf_read_data
*data
= info
;
3222 struct perf_event
*sub
, *event
= data
->event
;
3223 struct perf_event_context
*ctx
= event
->ctx
;
3224 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3225 struct pmu
*pmu
= event
->pmu
;
3228 * If this is a task context, we need to check whether it is
3229 * the current task context of this cpu. If not it has been
3230 * scheduled out before the smp call arrived. In that case
3231 * event->count would have been updated to a recent sample
3232 * when the event was scheduled out.
3234 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3237 raw_spin_lock(&ctx
->lock
);
3238 if (ctx
->is_active
) {
3239 update_context_time(ctx
);
3240 update_cgrp_time_from_event(event
);
3243 update_event_times(event
);
3244 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3253 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3257 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3258 update_event_times(sub
);
3259 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3261 * Use sibling's PMU rather than @event's since
3262 * sibling could be on different (eg: software) PMU.
3264 sub
->pmu
->read(sub
);
3268 data
->ret
= pmu
->commit_txn(pmu
);
3271 raw_spin_unlock(&ctx
->lock
);
3274 static inline u64
perf_event_count(struct perf_event
*event
)
3276 if (event
->pmu
->count
)
3277 return event
->pmu
->count(event
);
3279 return __perf_event_count(event
);
3283 * NMI-safe method to read a local event, that is an event that
3285 * - either for the current task, or for this CPU
3286 * - does not have inherit set, for inherited task events
3287 * will not be local and we cannot read them atomically
3288 * - must not have a pmu::count method
3290 u64
perf_event_read_local(struct perf_event
*event
)
3292 unsigned long flags
;
3296 * Disabling interrupts avoids all counter scheduling (context
3297 * switches, timer based rotation and IPIs).
3299 local_irq_save(flags
);
3301 /* If this is a per-task event, it must be for current */
3302 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3303 event
->hw
.target
!= current
);
3305 /* If this is a per-CPU event, it must be for this CPU */
3306 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3307 event
->cpu
!= smp_processor_id());
3310 * It must not be an event with inherit set, we cannot read
3311 * all child counters from atomic context.
3313 WARN_ON_ONCE(event
->attr
.inherit
);
3316 * It must not have a pmu::count method, those are not
3319 WARN_ON_ONCE(event
->pmu
->count
);
3322 * If the event is currently on this CPU, its either a per-task event,
3323 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3326 if (event
->oncpu
== smp_processor_id())
3327 event
->pmu
->read(event
);
3329 val
= local64_read(&event
->count
);
3330 local_irq_restore(flags
);
3335 static int perf_event_read(struct perf_event
*event
, bool group
)
3340 * If event is enabled and currently active on a CPU, update the
3341 * value in the event structure:
3343 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3344 struct perf_read_data data
= {
3349 smp_call_function_single(event
->oncpu
,
3350 __perf_event_read
, &data
, 1);
3352 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3353 struct perf_event_context
*ctx
= event
->ctx
;
3354 unsigned long flags
;
3356 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3358 * may read while context is not active
3359 * (e.g., thread is blocked), in that case
3360 * we cannot update context time
3362 if (ctx
->is_active
) {
3363 update_context_time(ctx
);
3364 update_cgrp_time_from_event(event
);
3367 update_group_times(event
);
3369 update_event_times(event
);
3370 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3377 * Initialize the perf_event context in a task_struct:
3379 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3381 raw_spin_lock_init(&ctx
->lock
);
3382 mutex_init(&ctx
->mutex
);
3383 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3384 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3385 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3386 INIT_LIST_HEAD(&ctx
->event_list
);
3387 atomic_set(&ctx
->refcount
, 1);
3390 static struct perf_event_context
*
3391 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3393 struct perf_event_context
*ctx
;
3395 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3399 __perf_event_init_context(ctx
);
3402 get_task_struct(task
);
3409 static struct task_struct
*
3410 find_lively_task_by_vpid(pid_t vpid
)
3412 struct task_struct
*task
;
3419 task
= find_task_by_vpid(vpid
);
3421 get_task_struct(task
);
3425 return ERR_PTR(-ESRCH
);
3427 /* Reuse ptrace permission checks for now. */
3429 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
3434 put_task_struct(task
);
3435 return ERR_PTR(err
);
3440 * Returns a matching context with refcount and pincount.
3442 static struct perf_event_context
*
3443 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3444 struct perf_event
*event
)
3446 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3447 struct perf_cpu_context
*cpuctx
;
3448 void *task_ctx_data
= NULL
;
3449 unsigned long flags
;
3451 int cpu
= event
->cpu
;
3454 /* Must be root to operate on a CPU event: */
3455 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3456 return ERR_PTR(-EACCES
);
3459 * We could be clever and allow to attach a event to an
3460 * offline CPU and activate it when the CPU comes up, but
3463 if (!cpu_online(cpu
))
3464 return ERR_PTR(-ENODEV
);
3466 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3475 ctxn
= pmu
->task_ctx_nr
;
3479 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3480 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3481 if (!task_ctx_data
) {
3488 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3490 clone_ctx
= unclone_ctx(ctx
);
3493 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3494 ctx
->task_ctx_data
= task_ctx_data
;
3495 task_ctx_data
= NULL
;
3497 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3502 ctx
= alloc_perf_context(pmu
, task
);
3507 if (task_ctx_data
) {
3508 ctx
->task_ctx_data
= task_ctx_data
;
3509 task_ctx_data
= NULL
;
3513 mutex_lock(&task
->perf_event_mutex
);
3515 * If it has already passed perf_event_exit_task().
3516 * we must see PF_EXITING, it takes this mutex too.
3518 if (task
->flags
& PF_EXITING
)
3520 else if (task
->perf_event_ctxp
[ctxn
])
3525 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3527 mutex_unlock(&task
->perf_event_mutex
);
3529 if (unlikely(err
)) {
3538 kfree(task_ctx_data
);
3542 kfree(task_ctx_data
);
3543 return ERR_PTR(err
);
3546 static void perf_event_free_filter(struct perf_event
*event
);
3547 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3549 static void free_event_rcu(struct rcu_head
*head
)
3551 struct perf_event
*event
;
3553 event
= container_of(head
, struct perf_event
, rcu_head
);
3555 put_pid_ns(event
->ns
);
3556 perf_event_free_filter(event
);
3560 static void ring_buffer_attach(struct perf_event
*event
,
3561 struct ring_buffer
*rb
);
3563 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3568 if (is_cgroup_event(event
))
3569 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3572 #ifdef CONFIG_NO_HZ_FULL
3573 static DEFINE_SPINLOCK(nr_freq_lock
);
3576 static void unaccount_freq_event_nohz(void)
3578 #ifdef CONFIG_NO_HZ_FULL
3579 spin_lock(&nr_freq_lock
);
3580 if (atomic_dec_and_test(&nr_freq_events
))
3581 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3582 spin_unlock(&nr_freq_lock
);
3586 static void unaccount_freq_event(void)
3588 if (tick_nohz_full_enabled())
3589 unaccount_freq_event_nohz();
3591 atomic_dec(&nr_freq_events
);
3594 static void unaccount_event(struct perf_event
*event
)
3601 if (event
->attach_state
& PERF_ATTACH_TASK
)
3603 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3604 atomic_dec(&nr_mmap_events
);
3605 if (event
->attr
.comm
)
3606 atomic_dec(&nr_comm_events
);
3607 if (event
->attr
.task
)
3608 atomic_dec(&nr_task_events
);
3609 if (event
->attr
.freq
)
3610 unaccount_freq_event();
3611 if (event
->attr
.context_switch
) {
3613 atomic_dec(&nr_switch_events
);
3615 if (is_cgroup_event(event
))
3617 if (has_branch_stack(event
))
3621 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
3622 schedule_delayed_work(&perf_sched_work
, HZ
);
3625 unaccount_event_cpu(event
, event
->cpu
);
3628 static void perf_sched_delayed(struct work_struct
*work
)
3630 mutex_lock(&perf_sched_mutex
);
3631 if (atomic_dec_and_test(&perf_sched_count
))
3632 static_branch_disable(&perf_sched_events
);
3633 mutex_unlock(&perf_sched_mutex
);
3637 * The following implement mutual exclusion of events on "exclusive" pmus
3638 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3639 * at a time, so we disallow creating events that might conflict, namely:
3641 * 1) cpu-wide events in the presence of per-task events,
3642 * 2) per-task events in the presence of cpu-wide events,
3643 * 3) two matching events on the same context.
3645 * The former two cases are handled in the allocation path (perf_event_alloc(),
3646 * _free_event()), the latter -- before the first perf_install_in_context().
3648 static int exclusive_event_init(struct perf_event
*event
)
3650 struct pmu
*pmu
= event
->pmu
;
3652 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3656 * Prevent co-existence of per-task and cpu-wide events on the
3657 * same exclusive pmu.
3659 * Negative pmu::exclusive_cnt means there are cpu-wide
3660 * events on this "exclusive" pmu, positive means there are
3663 * Since this is called in perf_event_alloc() path, event::ctx
3664 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3665 * to mean "per-task event", because unlike other attach states it
3666 * never gets cleared.
3668 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3669 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3672 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3679 static void exclusive_event_destroy(struct perf_event
*event
)
3681 struct pmu
*pmu
= event
->pmu
;
3683 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3686 /* see comment in exclusive_event_init() */
3687 if (event
->attach_state
& PERF_ATTACH_TASK
)
3688 atomic_dec(&pmu
->exclusive_cnt
);
3690 atomic_inc(&pmu
->exclusive_cnt
);
3693 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3695 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3696 (e1
->cpu
== e2
->cpu
||
3703 /* Called under the same ctx::mutex as perf_install_in_context() */
3704 static bool exclusive_event_installable(struct perf_event
*event
,
3705 struct perf_event_context
*ctx
)
3707 struct perf_event
*iter_event
;
3708 struct pmu
*pmu
= event
->pmu
;
3710 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3713 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3714 if (exclusive_event_match(iter_event
, event
))
3721 static void _free_event(struct perf_event
*event
)
3723 irq_work_sync(&event
->pending
);
3725 unaccount_event(event
);
3729 * Can happen when we close an event with re-directed output.
3731 * Since we have a 0 refcount, perf_mmap_close() will skip
3732 * over us; possibly making our ring_buffer_put() the last.
3734 mutex_lock(&event
->mmap_mutex
);
3735 ring_buffer_attach(event
, NULL
);
3736 mutex_unlock(&event
->mmap_mutex
);
3739 if (is_cgroup_event(event
))
3740 perf_detach_cgroup(event
);
3742 if (!event
->parent
) {
3743 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3744 put_callchain_buffers();
3747 perf_event_free_bpf_prog(event
);
3750 event
->destroy(event
);
3753 put_ctx(event
->ctx
);
3756 exclusive_event_destroy(event
);
3757 module_put(event
->pmu
->module
);
3760 call_rcu(&event
->rcu_head
, free_event_rcu
);
3764 * Used to free events which have a known refcount of 1, such as in error paths
3765 * where the event isn't exposed yet and inherited events.
3767 static void free_event(struct perf_event
*event
)
3769 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3770 "unexpected event refcount: %ld; ptr=%p\n",
3771 atomic_long_read(&event
->refcount
), event
)) {
3772 /* leak to avoid use-after-free */
3780 * Remove user event from the owner task.
3782 static void perf_remove_from_owner(struct perf_event
*event
)
3784 struct task_struct
*owner
;
3788 * Matches the smp_store_release() in perf_event_exit_task(). If we
3789 * observe !owner it means the list deletion is complete and we can
3790 * indeed free this event, otherwise we need to serialize on
3791 * owner->perf_event_mutex.
3793 owner
= lockless_dereference(event
->owner
);
3796 * Since delayed_put_task_struct() also drops the last
3797 * task reference we can safely take a new reference
3798 * while holding the rcu_read_lock().
3800 get_task_struct(owner
);
3806 * If we're here through perf_event_exit_task() we're already
3807 * holding ctx->mutex which would be an inversion wrt. the
3808 * normal lock order.
3810 * However we can safely take this lock because its the child
3813 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3816 * We have to re-check the event->owner field, if it is cleared
3817 * we raced with perf_event_exit_task(), acquiring the mutex
3818 * ensured they're done, and we can proceed with freeing the
3822 list_del_init(&event
->owner_entry
);
3823 smp_store_release(&event
->owner
, NULL
);
3825 mutex_unlock(&owner
->perf_event_mutex
);
3826 put_task_struct(owner
);
3830 static void put_event(struct perf_event
*event
)
3832 if (!atomic_long_dec_and_test(&event
->refcount
))
3839 * Kill an event dead; while event:refcount will preserve the event
3840 * object, it will not preserve its functionality. Once the last 'user'
3841 * gives up the object, we'll destroy the thing.
3843 int perf_event_release_kernel(struct perf_event
*event
)
3845 struct perf_event_context
*ctx
= event
->ctx
;
3846 struct perf_event
*child
, *tmp
;
3849 * If we got here through err_file: fput(event_file); we will not have
3850 * attached to a context yet.
3853 WARN_ON_ONCE(event
->attach_state
&
3854 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
3858 if (!is_kernel_event(event
))
3859 perf_remove_from_owner(event
);
3861 ctx
= perf_event_ctx_lock(event
);
3862 WARN_ON_ONCE(ctx
->parent_ctx
);
3863 perf_remove_from_context(event
, DETACH_GROUP
);
3865 raw_spin_lock_irq(&ctx
->lock
);
3867 * Mark this even as STATE_DEAD, there is no external reference to it
3870 * Anybody acquiring event->child_mutex after the below loop _must_
3871 * also see this, most importantly inherit_event() which will avoid
3872 * placing more children on the list.
3874 * Thus this guarantees that we will in fact observe and kill _ALL_
3877 event
->state
= PERF_EVENT_STATE_DEAD
;
3878 raw_spin_unlock_irq(&ctx
->lock
);
3880 perf_event_ctx_unlock(event
, ctx
);
3883 mutex_lock(&event
->child_mutex
);
3884 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3887 * Cannot change, child events are not migrated, see the
3888 * comment with perf_event_ctx_lock_nested().
3890 ctx
= lockless_dereference(child
->ctx
);
3892 * Since child_mutex nests inside ctx::mutex, we must jump
3893 * through hoops. We start by grabbing a reference on the ctx.
3895 * Since the event cannot get freed while we hold the
3896 * child_mutex, the context must also exist and have a !0
3902 * Now that we have a ctx ref, we can drop child_mutex, and
3903 * acquire ctx::mutex without fear of it going away. Then we
3904 * can re-acquire child_mutex.
3906 mutex_unlock(&event
->child_mutex
);
3907 mutex_lock(&ctx
->mutex
);
3908 mutex_lock(&event
->child_mutex
);
3911 * Now that we hold ctx::mutex and child_mutex, revalidate our
3912 * state, if child is still the first entry, it didn't get freed
3913 * and we can continue doing so.
3915 tmp
= list_first_entry_or_null(&event
->child_list
,
3916 struct perf_event
, child_list
);
3918 perf_remove_from_context(child
, DETACH_GROUP
);
3919 list_del(&child
->child_list
);
3922 * This matches the refcount bump in inherit_event();
3923 * this can't be the last reference.
3928 mutex_unlock(&event
->child_mutex
);
3929 mutex_unlock(&ctx
->mutex
);
3933 mutex_unlock(&event
->child_mutex
);
3936 put_event(event
); /* Must be the 'last' reference */
3939 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3942 * Called when the last reference to the file is gone.
3944 static int perf_release(struct inode
*inode
, struct file
*file
)
3946 perf_event_release_kernel(file
->private_data
);
3950 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3952 struct perf_event
*child
;
3958 mutex_lock(&event
->child_mutex
);
3960 (void)perf_event_read(event
, false);
3961 total
+= perf_event_count(event
);
3963 *enabled
+= event
->total_time_enabled
+
3964 atomic64_read(&event
->child_total_time_enabled
);
3965 *running
+= event
->total_time_running
+
3966 atomic64_read(&event
->child_total_time_running
);
3968 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3969 (void)perf_event_read(child
, false);
3970 total
+= perf_event_count(child
);
3971 *enabled
+= child
->total_time_enabled
;
3972 *running
+= child
->total_time_running
;
3974 mutex_unlock(&event
->child_mutex
);
3978 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3980 static int __perf_read_group_add(struct perf_event
*leader
,
3981 u64 read_format
, u64
*values
)
3983 struct perf_event
*sub
;
3984 int n
= 1; /* skip @nr */
3987 ret
= perf_event_read(leader
, true);
3992 * Since we co-schedule groups, {enabled,running} times of siblings
3993 * will be identical to those of the leader, so we only publish one
3996 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3997 values
[n
++] += leader
->total_time_enabled
+
3998 atomic64_read(&leader
->child_total_time_enabled
);
4001 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4002 values
[n
++] += leader
->total_time_running
+
4003 atomic64_read(&leader
->child_total_time_running
);
4007 * Write {count,id} tuples for every sibling.
4009 values
[n
++] += perf_event_count(leader
);
4010 if (read_format
& PERF_FORMAT_ID
)
4011 values
[n
++] = primary_event_id(leader
);
4013 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4014 values
[n
++] += perf_event_count(sub
);
4015 if (read_format
& PERF_FORMAT_ID
)
4016 values
[n
++] = primary_event_id(sub
);
4022 static int perf_read_group(struct perf_event
*event
,
4023 u64 read_format
, char __user
*buf
)
4025 struct perf_event
*leader
= event
->group_leader
, *child
;
4026 struct perf_event_context
*ctx
= leader
->ctx
;
4030 lockdep_assert_held(&ctx
->mutex
);
4032 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4036 values
[0] = 1 + leader
->nr_siblings
;
4039 * By locking the child_mutex of the leader we effectively
4040 * lock the child list of all siblings.. XXX explain how.
4042 mutex_lock(&leader
->child_mutex
);
4044 ret
= __perf_read_group_add(leader
, read_format
, values
);
4048 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4049 ret
= __perf_read_group_add(child
, read_format
, values
);
4054 mutex_unlock(&leader
->child_mutex
);
4056 ret
= event
->read_size
;
4057 if (copy_to_user(buf
, values
, event
->read_size
))
4062 mutex_unlock(&leader
->child_mutex
);
4068 static int perf_read_one(struct perf_event
*event
,
4069 u64 read_format
, char __user
*buf
)
4071 u64 enabled
, running
;
4075 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4076 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4077 values
[n
++] = enabled
;
4078 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4079 values
[n
++] = running
;
4080 if (read_format
& PERF_FORMAT_ID
)
4081 values
[n
++] = primary_event_id(event
);
4083 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4086 return n
* sizeof(u64
);
4089 static bool is_event_hup(struct perf_event
*event
)
4093 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4096 mutex_lock(&event
->child_mutex
);
4097 no_children
= list_empty(&event
->child_list
);
4098 mutex_unlock(&event
->child_mutex
);
4103 * Read the performance event - simple non blocking version for now
4106 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4108 u64 read_format
= event
->attr
.read_format
;
4112 * Return end-of-file for a read on a event that is in
4113 * error state (i.e. because it was pinned but it couldn't be
4114 * scheduled on to the CPU at some point).
4116 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4119 if (count
< event
->read_size
)
4122 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4123 if (read_format
& PERF_FORMAT_GROUP
)
4124 ret
= perf_read_group(event
, read_format
, buf
);
4126 ret
= perf_read_one(event
, read_format
, buf
);
4132 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4134 struct perf_event
*event
= file
->private_data
;
4135 struct perf_event_context
*ctx
;
4138 ctx
= perf_event_ctx_lock(event
);
4139 ret
= __perf_read(event
, buf
, count
);
4140 perf_event_ctx_unlock(event
, ctx
);
4145 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4147 struct perf_event
*event
= file
->private_data
;
4148 struct ring_buffer
*rb
;
4149 unsigned int events
= POLLHUP
;
4151 poll_wait(file
, &event
->waitq
, wait
);
4153 if (is_event_hup(event
))
4157 * Pin the event->rb by taking event->mmap_mutex; otherwise
4158 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4160 mutex_lock(&event
->mmap_mutex
);
4163 events
= atomic_xchg(&rb
->poll
, 0);
4164 mutex_unlock(&event
->mmap_mutex
);
4168 static void _perf_event_reset(struct perf_event
*event
)
4170 (void)perf_event_read(event
, false);
4171 local64_set(&event
->count
, 0);
4172 perf_event_update_userpage(event
);
4176 * Holding the top-level event's child_mutex means that any
4177 * descendant process that has inherited this event will block
4178 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4179 * task existence requirements of perf_event_enable/disable.
4181 static void perf_event_for_each_child(struct perf_event
*event
,
4182 void (*func
)(struct perf_event
*))
4184 struct perf_event
*child
;
4186 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4188 mutex_lock(&event
->child_mutex
);
4190 list_for_each_entry(child
, &event
->child_list
, child_list
)
4192 mutex_unlock(&event
->child_mutex
);
4195 static void perf_event_for_each(struct perf_event
*event
,
4196 void (*func
)(struct perf_event
*))
4198 struct perf_event_context
*ctx
= event
->ctx
;
4199 struct perf_event
*sibling
;
4201 lockdep_assert_held(&ctx
->mutex
);
4203 event
= event
->group_leader
;
4205 perf_event_for_each_child(event
, func
);
4206 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4207 perf_event_for_each_child(sibling
, func
);
4210 static void __perf_event_period(struct perf_event
*event
,
4211 struct perf_cpu_context
*cpuctx
,
4212 struct perf_event_context
*ctx
,
4215 u64 value
= *((u64
*)info
);
4218 if (event
->attr
.freq
) {
4219 event
->attr
.sample_freq
= value
;
4221 event
->attr
.sample_period
= value
;
4222 event
->hw
.sample_period
= value
;
4225 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4227 perf_pmu_disable(ctx
->pmu
);
4229 * We could be throttled; unthrottle now to avoid the tick
4230 * trying to unthrottle while we already re-started the event.
4232 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4233 event
->hw
.interrupts
= 0;
4234 perf_log_throttle(event
, 1);
4236 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4239 local64_set(&event
->hw
.period_left
, 0);
4242 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4243 perf_pmu_enable(ctx
->pmu
);
4247 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4251 if (!is_sampling_event(event
))
4254 if (copy_from_user(&value
, arg
, sizeof(value
)))
4260 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4263 event_function_call(event
, __perf_event_period
, &value
);
4268 static const struct file_operations perf_fops
;
4270 static inline int perf_fget_light(int fd
, struct fd
*p
)
4272 struct fd f
= fdget(fd
);
4276 if (f
.file
->f_op
!= &perf_fops
) {
4284 static int perf_event_set_output(struct perf_event
*event
,
4285 struct perf_event
*output_event
);
4286 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4287 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4289 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4291 void (*func
)(struct perf_event
*);
4295 case PERF_EVENT_IOC_ENABLE
:
4296 func
= _perf_event_enable
;
4298 case PERF_EVENT_IOC_DISABLE
:
4299 func
= _perf_event_disable
;
4301 case PERF_EVENT_IOC_RESET
:
4302 func
= _perf_event_reset
;
4305 case PERF_EVENT_IOC_REFRESH
:
4306 return _perf_event_refresh(event
, arg
);
4308 case PERF_EVENT_IOC_PERIOD
:
4309 return perf_event_period(event
, (u64 __user
*)arg
);
4311 case PERF_EVENT_IOC_ID
:
4313 u64 id
= primary_event_id(event
);
4315 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4320 case PERF_EVENT_IOC_SET_OUTPUT
:
4324 struct perf_event
*output_event
;
4326 ret
= perf_fget_light(arg
, &output
);
4329 output_event
= output
.file
->private_data
;
4330 ret
= perf_event_set_output(event
, output_event
);
4333 ret
= perf_event_set_output(event
, NULL
);
4338 case PERF_EVENT_IOC_SET_FILTER
:
4339 return perf_event_set_filter(event
, (void __user
*)arg
);
4341 case PERF_EVENT_IOC_SET_BPF
:
4342 return perf_event_set_bpf_prog(event
, arg
);
4348 if (flags
& PERF_IOC_FLAG_GROUP
)
4349 perf_event_for_each(event
, func
);
4351 perf_event_for_each_child(event
, func
);
4356 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4358 struct perf_event
*event
= file
->private_data
;
4359 struct perf_event_context
*ctx
;
4362 ctx
= perf_event_ctx_lock(event
);
4363 ret
= _perf_ioctl(event
, cmd
, arg
);
4364 perf_event_ctx_unlock(event
, ctx
);
4369 #ifdef CONFIG_COMPAT
4370 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4373 switch (_IOC_NR(cmd
)) {
4374 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4375 case _IOC_NR(PERF_EVENT_IOC_ID
):
4376 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4377 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4378 cmd
&= ~IOCSIZE_MASK
;
4379 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4383 return perf_ioctl(file
, cmd
, arg
);
4386 # define perf_compat_ioctl NULL
4389 int perf_event_task_enable(void)
4391 struct perf_event_context
*ctx
;
4392 struct perf_event
*event
;
4394 mutex_lock(¤t
->perf_event_mutex
);
4395 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4396 ctx
= perf_event_ctx_lock(event
);
4397 perf_event_for_each_child(event
, _perf_event_enable
);
4398 perf_event_ctx_unlock(event
, ctx
);
4400 mutex_unlock(¤t
->perf_event_mutex
);
4405 int perf_event_task_disable(void)
4407 struct perf_event_context
*ctx
;
4408 struct perf_event
*event
;
4410 mutex_lock(¤t
->perf_event_mutex
);
4411 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4412 ctx
= perf_event_ctx_lock(event
);
4413 perf_event_for_each_child(event
, _perf_event_disable
);
4414 perf_event_ctx_unlock(event
, ctx
);
4416 mutex_unlock(¤t
->perf_event_mutex
);
4421 static int perf_event_index(struct perf_event
*event
)
4423 if (event
->hw
.state
& PERF_HES_STOPPED
)
4426 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4429 return event
->pmu
->event_idx(event
);
4432 static void calc_timer_values(struct perf_event
*event
,
4439 *now
= perf_clock();
4440 ctx_time
= event
->shadow_ctx_time
+ *now
;
4441 *enabled
= ctx_time
- event
->tstamp_enabled
;
4442 *running
= ctx_time
- event
->tstamp_running
;
4445 static void perf_event_init_userpage(struct perf_event
*event
)
4447 struct perf_event_mmap_page
*userpg
;
4448 struct ring_buffer
*rb
;
4451 rb
= rcu_dereference(event
->rb
);
4455 userpg
= rb
->user_page
;
4457 /* Allow new userspace to detect that bit 0 is deprecated */
4458 userpg
->cap_bit0_is_deprecated
= 1;
4459 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4460 userpg
->data_offset
= PAGE_SIZE
;
4461 userpg
->data_size
= perf_data_size(rb
);
4467 void __weak
arch_perf_update_userpage(
4468 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4473 * Callers need to ensure there can be no nesting of this function, otherwise
4474 * the seqlock logic goes bad. We can not serialize this because the arch
4475 * code calls this from NMI context.
4477 void perf_event_update_userpage(struct perf_event
*event
)
4479 struct perf_event_mmap_page
*userpg
;
4480 struct ring_buffer
*rb
;
4481 u64 enabled
, running
, now
;
4484 rb
= rcu_dereference(event
->rb
);
4489 * compute total_time_enabled, total_time_running
4490 * based on snapshot values taken when the event
4491 * was last scheduled in.
4493 * we cannot simply called update_context_time()
4494 * because of locking issue as we can be called in
4497 calc_timer_values(event
, &now
, &enabled
, &running
);
4499 userpg
= rb
->user_page
;
4501 * Disable preemption so as to not let the corresponding user-space
4502 * spin too long if we get preempted.
4507 userpg
->index
= perf_event_index(event
);
4508 userpg
->offset
= perf_event_count(event
);
4510 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4512 userpg
->time_enabled
= enabled
+
4513 atomic64_read(&event
->child_total_time_enabled
);
4515 userpg
->time_running
= running
+
4516 atomic64_read(&event
->child_total_time_running
);
4518 arch_perf_update_userpage(event
, userpg
, now
);
4527 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4529 struct perf_event
*event
= vma
->vm_file
->private_data
;
4530 struct ring_buffer
*rb
;
4531 int ret
= VM_FAULT_SIGBUS
;
4533 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4534 if (vmf
->pgoff
== 0)
4540 rb
= rcu_dereference(event
->rb
);
4544 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4547 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4551 get_page(vmf
->page
);
4552 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4553 vmf
->page
->index
= vmf
->pgoff
;
4562 static void ring_buffer_attach(struct perf_event
*event
,
4563 struct ring_buffer
*rb
)
4565 struct ring_buffer
*old_rb
= NULL
;
4566 unsigned long flags
;
4570 * Should be impossible, we set this when removing
4571 * event->rb_entry and wait/clear when adding event->rb_entry.
4573 WARN_ON_ONCE(event
->rcu_pending
);
4576 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4577 list_del_rcu(&event
->rb_entry
);
4578 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4580 event
->rcu_batches
= get_state_synchronize_rcu();
4581 event
->rcu_pending
= 1;
4585 if (event
->rcu_pending
) {
4586 cond_synchronize_rcu(event
->rcu_batches
);
4587 event
->rcu_pending
= 0;
4590 spin_lock_irqsave(&rb
->event_lock
, flags
);
4591 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4592 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4595 rcu_assign_pointer(event
->rb
, rb
);
4598 ring_buffer_put(old_rb
);
4600 * Since we detached before setting the new rb, so that we
4601 * could attach the new rb, we could have missed a wakeup.
4604 wake_up_all(&event
->waitq
);
4608 static void ring_buffer_wakeup(struct perf_event
*event
)
4610 struct ring_buffer
*rb
;
4613 rb
= rcu_dereference(event
->rb
);
4615 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4616 wake_up_all(&event
->waitq
);
4621 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4623 struct ring_buffer
*rb
;
4626 rb
= rcu_dereference(event
->rb
);
4628 if (!atomic_inc_not_zero(&rb
->refcount
))
4636 void ring_buffer_put(struct ring_buffer
*rb
)
4638 if (!atomic_dec_and_test(&rb
->refcount
))
4641 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4643 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4646 static void perf_mmap_open(struct vm_area_struct
*vma
)
4648 struct perf_event
*event
= vma
->vm_file
->private_data
;
4650 atomic_inc(&event
->mmap_count
);
4651 atomic_inc(&event
->rb
->mmap_count
);
4654 atomic_inc(&event
->rb
->aux_mmap_count
);
4656 if (event
->pmu
->event_mapped
)
4657 event
->pmu
->event_mapped(event
);
4661 * A buffer can be mmap()ed multiple times; either directly through the same
4662 * event, or through other events by use of perf_event_set_output().
4664 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4665 * the buffer here, where we still have a VM context. This means we need
4666 * to detach all events redirecting to us.
4668 static void perf_mmap_close(struct vm_area_struct
*vma
)
4670 struct perf_event
*event
= vma
->vm_file
->private_data
;
4672 struct ring_buffer
*rb
= ring_buffer_get(event
);
4673 struct user_struct
*mmap_user
= rb
->mmap_user
;
4674 int mmap_locked
= rb
->mmap_locked
;
4675 unsigned long size
= perf_data_size(rb
);
4677 if (event
->pmu
->event_unmapped
)
4678 event
->pmu
->event_unmapped(event
);
4681 * rb->aux_mmap_count will always drop before rb->mmap_count and
4682 * event->mmap_count, so it is ok to use event->mmap_mutex to
4683 * serialize with perf_mmap here.
4685 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4686 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4687 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4688 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4691 mutex_unlock(&event
->mmap_mutex
);
4694 atomic_dec(&rb
->mmap_count
);
4696 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4699 ring_buffer_attach(event
, NULL
);
4700 mutex_unlock(&event
->mmap_mutex
);
4702 /* If there's still other mmap()s of this buffer, we're done. */
4703 if (atomic_read(&rb
->mmap_count
))
4707 * No other mmap()s, detach from all other events that might redirect
4708 * into the now unreachable buffer. Somewhat complicated by the
4709 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4713 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4714 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4716 * This event is en-route to free_event() which will
4717 * detach it and remove it from the list.
4723 mutex_lock(&event
->mmap_mutex
);
4725 * Check we didn't race with perf_event_set_output() which can
4726 * swizzle the rb from under us while we were waiting to
4727 * acquire mmap_mutex.
4729 * If we find a different rb; ignore this event, a next
4730 * iteration will no longer find it on the list. We have to
4731 * still restart the iteration to make sure we're not now
4732 * iterating the wrong list.
4734 if (event
->rb
== rb
)
4735 ring_buffer_attach(event
, NULL
);
4737 mutex_unlock(&event
->mmap_mutex
);
4741 * Restart the iteration; either we're on the wrong list or
4742 * destroyed its integrity by doing a deletion.
4749 * It could be there's still a few 0-ref events on the list; they'll
4750 * get cleaned up by free_event() -- they'll also still have their
4751 * ref on the rb and will free it whenever they are done with it.
4753 * Aside from that, this buffer is 'fully' detached and unmapped,
4754 * undo the VM accounting.
4757 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4758 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4759 free_uid(mmap_user
);
4762 ring_buffer_put(rb
); /* could be last */
4765 static const struct vm_operations_struct perf_mmap_vmops
= {
4766 .open
= perf_mmap_open
,
4767 .close
= perf_mmap_close
, /* non mergable */
4768 .fault
= perf_mmap_fault
,
4769 .page_mkwrite
= perf_mmap_fault
,
4772 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4774 struct perf_event
*event
= file
->private_data
;
4775 unsigned long user_locked
, user_lock_limit
;
4776 struct user_struct
*user
= current_user();
4777 unsigned long locked
, lock_limit
;
4778 struct ring_buffer
*rb
= NULL
;
4779 unsigned long vma_size
;
4780 unsigned long nr_pages
;
4781 long user_extra
= 0, extra
= 0;
4782 int ret
= 0, flags
= 0;
4785 * Don't allow mmap() of inherited per-task counters. This would
4786 * create a performance issue due to all children writing to the
4789 if (event
->cpu
== -1 && event
->attr
.inherit
)
4792 if (!(vma
->vm_flags
& VM_SHARED
))
4795 vma_size
= vma
->vm_end
- vma
->vm_start
;
4797 if (vma
->vm_pgoff
== 0) {
4798 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4801 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4802 * mapped, all subsequent mappings should have the same size
4803 * and offset. Must be above the normal perf buffer.
4805 u64 aux_offset
, aux_size
;
4810 nr_pages
= vma_size
/ PAGE_SIZE
;
4812 mutex_lock(&event
->mmap_mutex
);
4819 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4820 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4822 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4825 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4828 /* already mapped with a different offset */
4829 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4832 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4835 /* already mapped with a different size */
4836 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4839 if (!is_power_of_2(nr_pages
))
4842 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4845 if (rb_has_aux(rb
)) {
4846 atomic_inc(&rb
->aux_mmap_count
);
4851 atomic_set(&rb
->aux_mmap_count
, 1);
4852 user_extra
= nr_pages
;
4858 * If we have rb pages ensure they're a power-of-two number, so we
4859 * can do bitmasks instead of modulo.
4861 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4864 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4867 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4869 mutex_lock(&event
->mmap_mutex
);
4871 if (event
->rb
->nr_pages
!= nr_pages
) {
4876 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4878 * Raced against perf_mmap_close() through
4879 * perf_event_set_output(). Try again, hope for better
4882 mutex_unlock(&event
->mmap_mutex
);
4889 user_extra
= nr_pages
+ 1;
4892 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4895 * Increase the limit linearly with more CPUs:
4897 user_lock_limit
*= num_online_cpus();
4899 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4901 if (user_locked
> user_lock_limit
)
4902 extra
= user_locked
- user_lock_limit
;
4904 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4905 lock_limit
>>= PAGE_SHIFT
;
4906 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4908 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4909 !capable(CAP_IPC_LOCK
)) {
4914 WARN_ON(!rb
&& event
->rb
);
4916 if (vma
->vm_flags
& VM_WRITE
)
4917 flags
|= RING_BUFFER_WRITABLE
;
4920 rb
= rb_alloc(nr_pages
,
4921 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4929 atomic_set(&rb
->mmap_count
, 1);
4930 rb
->mmap_user
= get_current_user();
4931 rb
->mmap_locked
= extra
;
4933 ring_buffer_attach(event
, rb
);
4935 perf_event_init_userpage(event
);
4936 perf_event_update_userpage(event
);
4938 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4939 event
->attr
.aux_watermark
, flags
);
4941 rb
->aux_mmap_locked
= extra
;
4946 atomic_long_add(user_extra
, &user
->locked_vm
);
4947 vma
->vm_mm
->pinned_vm
+= extra
;
4949 atomic_inc(&event
->mmap_count
);
4951 atomic_dec(&rb
->mmap_count
);
4954 mutex_unlock(&event
->mmap_mutex
);
4957 * Since pinned accounting is per vm we cannot allow fork() to copy our
4960 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4961 vma
->vm_ops
= &perf_mmap_vmops
;
4963 if (event
->pmu
->event_mapped
)
4964 event
->pmu
->event_mapped(event
);
4969 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4971 struct inode
*inode
= file_inode(filp
);
4972 struct perf_event
*event
= filp
->private_data
;
4976 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4977 inode_unlock(inode
);
4985 static const struct file_operations perf_fops
= {
4986 .llseek
= no_llseek
,
4987 .release
= perf_release
,
4990 .unlocked_ioctl
= perf_ioctl
,
4991 .compat_ioctl
= perf_compat_ioctl
,
4993 .fasync
= perf_fasync
,
4999 * If there's data, ensure we set the poll() state and publish everything
5000 * to user-space before waking everybody up.
5003 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5005 /* only the parent has fasync state */
5007 event
= event
->parent
;
5008 return &event
->fasync
;
5011 void perf_event_wakeup(struct perf_event
*event
)
5013 ring_buffer_wakeup(event
);
5015 if (event
->pending_kill
) {
5016 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5017 event
->pending_kill
= 0;
5021 static void perf_pending_event(struct irq_work
*entry
)
5023 struct perf_event
*event
= container_of(entry
,
5024 struct perf_event
, pending
);
5027 rctx
= perf_swevent_get_recursion_context();
5029 * If we 'fail' here, that's OK, it means recursion is already disabled
5030 * and we won't recurse 'further'.
5033 if (event
->pending_disable
) {
5034 event
->pending_disable
= 0;
5035 perf_event_disable_local(event
);
5038 if (event
->pending_wakeup
) {
5039 event
->pending_wakeup
= 0;
5040 perf_event_wakeup(event
);
5044 perf_swevent_put_recursion_context(rctx
);
5048 * We assume there is only KVM supporting the callbacks.
5049 * Later on, we might change it to a list if there is
5050 * another virtualization implementation supporting the callbacks.
5052 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5054 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5056 perf_guest_cbs
= cbs
;
5059 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5061 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5063 perf_guest_cbs
= NULL
;
5066 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5069 perf_output_sample_regs(struct perf_output_handle
*handle
,
5070 struct pt_regs
*regs
, u64 mask
)
5074 for_each_set_bit(bit
, (const unsigned long *) &mask
,
5075 sizeof(mask
) * BITS_PER_BYTE
) {
5078 val
= perf_reg_value(regs
, bit
);
5079 perf_output_put(handle
, val
);
5083 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5084 struct pt_regs
*regs
,
5085 struct pt_regs
*regs_user_copy
)
5087 if (user_mode(regs
)) {
5088 regs_user
->abi
= perf_reg_abi(current
);
5089 regs_user
->regs
= regs
;
5090 } else if (current
->mm
) {
5091 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5093 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5094 regs_user
->regs
= NULL
;
5098 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5099 struct pt_regs
*regs
)
5101 regs_intr
->regs
= regs
;
5102 regs_intr
->abi
= perf_reg_abi(current
);
5107 * Get remaining task size from user stack pointer.
5109 * It'd be better to take stack vma map and limit this more
5110 * precisly, but there's no way to get it safely under interrupt,
5111 * so using TASK_SIZE as limit.
5113 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5115 unsigned long addr
= perf_user_stack_pointer(regs
);
5117 if (!addr
|| addr
>= TASK_SIZE
)
5120 return TASK_SIZE
- addr
;
5124 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5125 struct pt_regs
*regs
)
5129 /* No regs, no stack pointer, no dump. */
5134 * Check if we fit in with the requested stack size into the:
5136 * If we don't, we limit the size to the TASK_SIZE.
5138 * - remaining sample size
5139 * If we don't, we customize the stack size to
5140 * fit in to the remaining sample size.
5143 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5144 stack_size
= min(stack_size
, (u16
) task_size
);
5146 /* Current header size plus static size and dynamic size. */
5147 header_size
+= 2 * sizeof(u64
);
5149 /* Do we fit in with the current stack dump size? */
5150 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5152 * If we overflow the maximum size for the sample,
5153 * we customize the stack dump size to fit in.
5155 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5156 stack_size
= round_up(stack_size
, sizeof(u64
));
5163 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5164 struct pt_regs
*regs
)
5166 /* Case of a kernel thread, nothing to dump */
5169 perf_output_put(handle
, size
);
5178 * - the size requested by user or the best one we can fit
5179 * in to the sample max size
5181 * - user stack dump data
5183 * - the actual dumped size
5187 perf_output_put(handle
, dump_size
);
5190 sp
= perf_user_stack_pointer(regs
);
5191 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5192 dyn_size
= dump_size
- rem
;
5194 perf_output_skip(handle
, rem
);
5197 perf_output_put(handle
, dyn_size
);
5201 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5202 struct perf_sample_data
*data
,
5203 struct perf_event
*event
)
5205 u64 sample_type
= event
->attr
.sample_type
;
5207 data
->type
= sample_type
;
5208 header
->size
+= event
->id_header_size
;
5210 if (sample_type
& PERF_SAMPLE_TID
) {
5211 /* namespace issues */
5212 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5213 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5216 if (sample_type
& PERF_SAMPLE_TIME
)
5217 data
->time
= perf_event_clock(event
);
5219 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5220 data
->id
= primary_event_id(event
);
5222 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5223 data
->stream_id
= event
->id
;
5225 if (sample_type
& PERF_SAMPLE_CPU
) {
5226 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5227 data
->cpu_entry
.reserved
= 0;
5231 void perf_event_header__init_id(struct perf_event_header
*header
,
5232 struct perf_sample_data
*data
,
5233 struct perf_event
*event
)
5235 if (event
->attr
.sample_id_all
)
5236 __perf_event_header__init_id(header
, data
, event
);
5239 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5240 struct perf_sample_data
*data
)
5242 u64 sample_type
= data
->type
;
5244 if (sample_type
& PERF_SAMPLE_TID
)
5245 perf_output_put(handle
, data
->tid_entry
);
5247 if (sample_type
& PERF_SAMPLE_TIME
)
5248 perf_output_put(handle
, data
->time
);
5250 if (sample_type
& PERF_SAMPLE_ID
)
5251 perf_output_put(handle
, data
->id
);
5253 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5254 perf_output_put(handle
, data
->stream_id
);
5256 if (sample_type
& PERF_SAMPLE_CPU
)
5257 perf_output_put(handle
, data
->cpu_entry
);
5259 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5260 perf_output_put(handle
, data
->id
);
5263 void perf_event__output_id_sample(struct perf_event
*event
,
5264 struct perf_output_handle
*handle
,
5265 struct perf_sample_data
*sample
)
5267 if (event
->attr
.sample_id_all
)
5268 __perf_event__output_id_sample(handle
, sample
);
5271 static void perf_output_read_one(struct perf_output_handle
*handle
,
5272 struct perf_event
*event
,
5273 u64 enabled
, u64 running
)
5275 u64 read_format
= event
->attr
.read_format
;
5279 values
[n
++] = perf_event_count(event
);
5280 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5281 values
[n
++] = enabled
+
5282 atomic64_read(&event
->child_total_time_enabled
);
5284 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5285 values
[n
++] = running
+
5286 atomic64_read(&event
->child_total_time_running
);
5288 if (read_format
& PERF_FORMAT_ID
)
5289 values
[n
++] = primary_event_id(event
);
5291 __output_copy(handle
, values
, n
* sizeof(u64
));
5295 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5297 static void perf_output_read_group(struct perf_output_handle
*handle
,
5298 struct perf_event
*event
,
5299 u64 enabled
, u64 running
)
5301 struct perf_event
*leader
= event
->group_leader
, *sub
;
5302 u64 read_format
= event
->attr
.read_format
;
5306 values
[n
++] = 1 + leader
->nr_siblings
;
5308 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5309 values
[n
++] = enabled
;
5311 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5312 values
[n
++] = running
;
5314 if (leader
!= event
)
5315 leader
->pmu
->read(leader
);
5317 values
[n
++] = perf_event_count(leader
);
5318 if (read_format
& PERF_FORMAT_ID
)
5319 values
[n
++] = primary_event_id(leader
);
5321 __output_copy(handle
, values
, n
* sizeof(u64
));
5323 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5326 if ((sub
!= event
) &&
5327 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5328 sub
->pmu
->read(sub
);
5330 values
[n
++] = perf_event_count(sub
);
5331 if (read_format
& PERF_FORMAT_ID
)
5332 values
[n
++] = primary_event_id(sub
);
5334 __output_copy(handle
, values
, n
* sizeof(u64
));
5338 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5339 PERF_FORMAT_TOTAL_TIME_RUNNING)
5341 static void perf_output_read(struct perf_output_handle
*handle
,
5342 struct perf_event
*event
)
5344 u64 enabled
= 0, running
= 0, now
;
5345 u64 read_format
= event
->attr
.read_format
;
5348 * compute total_time_enabled, total_time_running
5349 * based on snapshot values taken when the event
5350 * was last scheduled in.
5352 * we cannot simply called update_context_time()
5353 * because of locking issue as we are called in
5356 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5357 calc_timer_values(event
, &now
, &enabled
, &running
);
5359 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5360 perf_output_read_group(handle
, event
, enabled
, running
);
5362 perf_output_read_one(handle
, event
, enabled
, running
);
5365 void perf_output_sample(struct perf_output_handle
*handle
,
5366 struct perf_event_header
*header
,
5367 struct perf_sample_data
*data
,
5368 struct perf_event
*event
)
5370 u64 sample_type
= data
->type
;
5372 perf_output_put(handle
, *header
);
5374 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5375 perf_output_put(handle
, data
->id
);
5377 if (sample_type
& PERF_SAMPLE_IP
)
5378 perf_output_put(handle
, data
->ip
);
5380 if (sample_type
& PERF_SAMPLE_TID
)
5381 perf_output_put(handle
, data
->tid_entry
);
5383 if (sample_type
& PERF_SAMPLE_TIME
)
5384 perf_output_put(handle
, data
->time
);
5386 if (sample_type
& PERF_SAMPLE_ADDR
)
5387 perf_output_put(handle
, data
->addr
);
5389 if (sample_type
& PERF_SAMPLE_ID
)
5390 perf_output_put(handle
, data
->id
);
5392 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5393 perf_output_put(handle
, data
->stream_id
);
5395 if (sample_type
& PERF_SAMPLE_CPU
)
5396 perf_output_put(handle
, data
->cpu_entry
);
5398 if (sample_type
& PERF_SAMPLE_PERIOD
)
5399 perf_output_put(handle
, data
->period
);
5401 if (sample_type
& PERF_SAMPLE_READ
)
5402 perf_output_read(handle
, event
);
5404 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5405 if (data
->callchain
) {
5408 if (data
->callchain
)
5409 size
+= data
->callchain
->nr
;
5411 size
*= sizeof(u64
);
5413 __output_copy(handle
, data
->callchain
, size
);
5416 perf_output_put(handle
, nr
);
5420 if (sample_type
& PERF_SAMPLE_RAW
) {
5422 u32 raw_size
= data
->raw
->size
;
5423 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5424 sizeof(u64
)) - sizeof(u32
);
5427 perf_output_put(handle
, real_size
);
5428 __output_copy(handle
, data
->raw
->data
, raw_size
);
5429 if (real_size
- raw_size
)
5430 __output_copy(handle
, &zero
, real_size
- raw_size
);
5436 .size
= sizeof(u32
),
5439 perf_output_put(handle
, raw
);
5443 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5444 if (data
->br_stack
) {
5447 size
= data
->br_stack
->nr
5448 * sizeof(struct perf_branch_entry
);
5450 perf_output_put(handle
, data
->br_stack
->nr
);
5451 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5454 * we always store at least the value of nr
5457 perf_output_put(handle
, nr
);
5461 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5462 u64 abi
= data
->regs_user
.abi
;
5465 * If there are no regs to dump, notice it through
5466 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5468 perf_output_put(handle
, abi
);
5471 u64 mask
= event
->attr
.sample_regs_user
;
5472 perf_output_sample_regs(handle
,
5473 data
->regs_user
.regs
,
5478 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5479 perf_output_sample_ustack(handle
,
5480 data
->stack_user_size
,
5481 data
->regs_user
.regs
);
5484 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5485 perf_output_put(handle
, data
->weight
);
5487 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5488 perf_output_put(handle
, data
->data_src
.val
);
5490 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5491 perf_output_put(handle
, data
->txn
);
5493 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5494 u64 abi
= data
->regs_intr
.abi
;
5496 * If there are no regs to dump, notice it through
5497 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5499 perf_output_put(handle
, abi
);
5502 u64 mask
= event
->attr
.sample_regs_intr
;
5504 perf_output_sample_regs(handle
,
5505 data
->regs_intr
.regs
,
5510 if (!event
->attr
.watermark
) {
5511 int wakeup_events
= event
->attr
.wakeup_events
;
5513 if (wakeup_events
) {
5514 struct ring_buffer
*rb
= handle
->rb
;
5515 int events
= local_inc_return(&rb
->events
);
5517 if (events
>= wakeup_events
) {
5518 local_sub(wakeup_events
, &rb
->events
);
5519 local_inc(&rb
->wakeup
);
5525 void perf_prepare_sample(struct perf_event_header
*header
,
5526 struct perf_sample_data
*data
,
5527 struct perf_event
*event
,
5528 struct pt_regs
*regs
)
5530 u64 sample_type
= event
->attr
.sample_type
;
5532 header
->type
= PERF_RECORD_SAMPLE
;
5533 header
->size
= sizeof(*header
) + event
->header_size
;
5536 header
->misc
|= perf_misc_flags(regs
);
5538 __perf_event_header__init_id(header
, data
, event
);
5540 if (sample_type
& PERF_SAMPLE_IP
)
5541 data
->ip
= perf_instruction_pointer(regs
);
5543 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5546 data
->callchain
= perf_callchain(event
, regs
);
5548 if (data
->callchain
)
5549 size
+= data
->callchain
->nr
;
5551 header
->size
+= size
* sizeof(u64
);
5554 if (sample_type
& PERF_SAMPLE_RAW
) {
5555 int size
= sizeof(u32
);
5558 size
+= data
->raw
->size
;
5560 size
+= sizeof(u32
);
5562 header
->size
+= round_up(size
, sizeof(u64
));
5565 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5566 int size
= sizeof(u64
); /* nr */
5567 if (data
->br_stack
) {
5568 size
+= data
->br_stack
->nr
5569 * sizeof(struct perf_branch_entry
);
5571 header
->size
+= size
;
5574 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5575 perf_sample_regs_user(&data
->regs_user
, regs
,
5576 &data
->regs_user_copy
);
5578 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5579 /* regs dump ABI info */
5580 int size
= sizeof(u64
);
5582 if (data
->regs_user
.regs
) {
5583 u64 mask
= event
->attr
.sample_regs_user
;
5584 size
+= hweight64(mask
) * sizeof(u64
);
5587 header
->size
+= size
;
5590 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5592 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5593 * processed as the last one or have additional check added
5594 * in case new sample type is added, because we could eat
5595 * up the rest of the sample size.
5597 u16 stack_size
= event
->attr
.sample_stack_user
;
5598 u16 size
= sizeof(u64
);
5600 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5601 data
->regs_user
.regs
);
5604 * If there is something to dump, add space for the dump
5605 * itself and for the field that tells the dynamic size,
5606 * which is how many have been actually dumped.
5609 size
+= sizeof(u64
) + stack_size
;
5611 data
->stack_user_size
= stack_size
;
5612 header
->size
+= size
;
5615 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5616 /* regs dump ABI info */
5617 int size
= sizeof(u64
);
5619 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5621 if (data
->regs_intr
.regs
) {
5622 u64 mask
= event
->attr
.sample_regs_intr
;
5624 size
+= hweight64(mask
) * sizeof(u64
);
5627 header
->size
+= size
;
5631 void perf_event_output(struct perf_event
*event
,
5632 struct perf_sample_data
*data
,
5633 struct pt_regs
*regs
)
5635 struct perf_output_handle handle
;
5636 struct perf_event_header header
;
5638 /* protect the callchain buffers */
5641 perf_prepare_sample(&header
, data
, event
, regs
);
5643 if (perf_output_begin(&handle
, event
, header
.size
))
5646 perf_output_sample(&handle
, &header
, data
, event
);
5648 perf_output_end(&handle
);
5658 struct perf_read_event
{
5659 struct perf_event_header header
;
5666 perf_event_read_event(struct perf_event
*event
,
5667 struct task_struct
*task
)
5669 struct perf_output_handle handle
;
5670 struct perf_sample_data sample
;
5671 struct perf_read_event read_event
= {
5673 .type
= PERF_RECORD_READ
,
5675 .size
= sizeof(read_event
) + event
->read_size
,
5677 .pid
= perf_event_pid(event
, task
),
5678 .tid
= perf_event_tid(event
, task
),
5682 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5683 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5687 perf_output_put(&handle
, read_event
);
5688 perf_output_read(&handle
, event
);
5689 perf_event__output_id_sample(event
, &handle
, &sample
);
5691 perf_output_end(&handle
);
5694 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5697 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5698 perf_event_aux_output_cb output
,
5701 struct perf_event
*event
;
5703 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5704 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5706 if (!event_filter_match(event
))
5708 output(event
, data
);
5713 perf_event_aux_task_ctx(perf_event_aux_output_cb output
, void *data
,
5714 struct perf_event_context
*task_ctx
)
5718 perf_event_aux_ctx(task_ctx
, output
, data
);
5724 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5725 struct perf_event_context
*task_ctx
)
5727 struct perf_cpu_context
*cpuctx
;
5728 struct perf_event_context
*ctx
;
5733 * If we have task_ctx != NULL we only notify
5734 * the task context itself. The task_ctx is set
5735 * only for EXIT events before releasing task
5739 perf_event_aux_task_ctx(output
, data
, task_ctx
);
5744 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5745 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5746 if (cpuctx
->unique_pmu
!= pmu
)
5748 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5749 ctxn
= pmu
->task_ctx_nr
;
5752 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5754 perf_event_aux_ctx(ctx
, output
, data
);
5756 put_cpu_ptr(pmu
->pmu_cpu_context
);
5762 * task tracking -- fork/exit
5764 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5767 struct perf_task_event
{
5768 struct task_struct
*task
;
5769 struct perf_event_context
*task_ctx
;
5772 struct perf_event_header header
;
5782 static int perf_event_task_match(struct perf_event
*event
)
5784 return event
->attr
.comm
|| event
->attr
.mmap
||
5785 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5789 static void perf_event_task_output(struct perf_event
*event
,
5792 struct perf_task_event
*task_event
= data
;
5793 struct perf_output_handle handle
;
5794 struct perf_sample_data sample
;
5795 struct task_struct
*task
= task_event
->task
;
5796 int ret
, size
= task_event
->event_id
.header
.size
;
5798 if (!perf_event_task_match(event
))
5801 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5803 ret
= perf_output_begin(&handle
, event
,
5804 task_event
->event_id
.header
.size
);
5808 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5809 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5811 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5812 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5814 task_event
->event_id
.time
= perf_event_clock(event
);
5816 perf_output_put(&handle
, task_event
->event_id
);
5818 perf_event__output_id_sample(event
, &handle
, &sample
);
5820 perf_output_end(&handle
);
5822 task_event
->event_id
.header
.size
= size
;
5825 static void perf_event_task(struct task_struct
*task
,
5826 struct perf_event_context
*task_ctx
,
5829 struct perf_task_event task_event
;
5831 if (!atomic_read(&nr_comm_events
) &&
5832 !atomic_read(&nr_mmap_events
) &&
5833 !atomic_read(&nr_task_events
))
5836 task_event
= (struct perf_task_event
){
5838 .task_ctx
= task_ctx
,
5841 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5843 .size
= sizeof(task_event
.event_id
),
5853 perf_event_aux(perf_event_task_output
,
5858 void perf_event_fork(struct task_struct
*task
)
5860 perf_event_task(task
, NULL
, 1);
5867 struct perf_comm_event
{
5868 struct task_struct
*task
;
5873 struct perf_event_header header
;
5880 static int perf_event_comm_match(struct perf_event
*event
)
5882 return event
->attr
.comm
;
5885 static void perf_event_comm_output(struct perf_event
*event
,
5888 struct perf_comm_event
*comm_event
= data
;
5889 struct perf_output_handle handle
;
5890 struct perf_sample_data sample
;
5891 int size
= comm_event
->event_id
.header
.size
;
5894 if (!perf_event_comm_match(event
))
5897 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5898 ret
= perf_output_begin(&handle
, event
,
5899 comm_event
->event_id
.header
.size
);
5904 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5905 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5907 perf_output_put(&handle
, comm_event
->event_id
);
5908 __output_copy(&handle
, comm_event
->comm
,
5909 comm_event
->comm_size
);
5911 perf_event__output_id_sample(event
, &handle
, &sample
);
5913 perf_output_end(&handle
);
5915 comm_event
->event_id
.header
.size
= size
;
5918 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5920 char comm
[TASK_COMM_LEN
];
5923 memset(comm
, 0, sizeof(comm
));
5924 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5925 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5927 comm_event
->comm
= comm
;
5928 comm_event
->comm_size
= size
;
5930 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5932 perf_event_aux(perf_event_comm_output
,
5937 void perf_event_comm(struct task_struct
*task
, bool exec
)
5939 struct perf_comm_event comm_event
;
5941 if (!atomic_read(&nr_comm_events
))
5944 comm_event
= (struct perf_comm_event
){
5950 .type
= PERF_RECORD_COMM
,
5951 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5959 perf_event_comm_event(&comm_event
);
5966 struct perf_mmap_event
{
5967 struct vm_area_struct
*vma
;
5969 const char *file_name
;
5977 struct perf_event_header header
;
5987 static int perf_event_mmap_match(struct perf_event
*event
,
5990 struct perf_mmap_event
*mmap_event
= data
;
5991 struct vm_area_struct
*vma
= mmap_event
->vma
;
5992 int executable
= vma
->vm_flags
& VM_EXEC
;
5994 return (!executable
&& event
->attr
.mmap_data
) ||
5995 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5998 static void perf_event_mmap_output(struct perf_event
*event
,
6001 struct perf_mmap_event
*mmap_event
= data
;
6002 struct perf_output_handle handle
;
6003 struct perf_sample_data sample
;
6004 int size
= mmap_event
->event_id
.header
.size
;
6007 if (!perf_event_mmap_match(event
, data
))
6010 if (event
->attr
.mmap2
) {
6011 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6012 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6013 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6014 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6015 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6016 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6017 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6020 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6021 ret
= perf_output_begin(&handle
, event
,
6022 mmap_event
->event_id
.header
.size
);
6026 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6027 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6029 perf_output_put(&handle
, mmap_event
->event_id
);
6031 if (event
->attr
.mmap2
) {
6032 perf_output_put(&handle
, mmap_event
->maj
);
6033 perf_output_put(&handle
, mmap_event
->min
);
6034 perf_output_put(&handle
, mmap_event
->ino
);
6035 perf_output_put(&handle
, mmap_event
->ino_generation
);
6036 perf_output_put(&handle
, mmap_event
->prot
);
6037 perf_output_put(&handle
, mmap_event
->flags
);
6040 __output_copy(&handle
, mmap_event
->file_name
,
6041 mmap_event
->file_size
);
6043 perf_event__output_id_sample(event
, &handle
, &sample
);
6045 perf_output_end(&handle
);
6047 mmap_event
->event_id
.header
.size
= size
;
6050 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6052 struct vm_area_struct
*vma
= mmap_event
->vma
;
6053 struct file
*file
= vma
->vm_file
;
6054 int maj
= 0, min
= 0;
6055 u64 ino
= 0, gen
= 0;
6056 u32 prot
= 0, flags
= 0;
6063 struct inode
*inode
;
6066 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6072 * d_path() works from the end of the rb backwards, so we
6073 * need to add enough zero bytes after the string to handle
6074 * the 64bit alignment we do later.
6076 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6081 inode
= file_inode(vma
->vm_file
);
6082 dev
= inode
->i_sb
->s_dev
;
6084 gen
= inode
->i_generation
;
6088 if (vma
->vm_flags
& VM_READ
)
6090 if (vma
->vm_flags
& VM_WRITE
)
6092 if (vma
->vm_flags
& VM_EXEC
)
6095 if (vma
->vm_flags
& VM_MAYSHARE
)
6098 flags
= MAP_PRIVATE
;
6100 if (vma
->vm_flags
& VM_DENYWRITE
)
6101 flags
|= MAP_DENYWRITE
;
6102 if (vma
->vm_flags
& VM_MAYEXEC
)
6103 flags
|= MAP_EXECUTABLE
;
6104 if (vma
->vm_flags
& VM_LOCKED
)
6105 flags
|= MAP_LOCKED
;
6106 if (vma
->vm_flags
& VM_HUGETLB
)
6107 flags
|= MAP_HUGETLB
;
6111 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6112 name
= (char *) vma
->vm_ops
->name(vma
);
6117 name
= (char *)arch_vma_name(vma
);
6121 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6122 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6126 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6127 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6137 strlcpy(tmp
, name
, sizeof(tmp
));
6141 * Since our buffer works in 8 byte units we need to align our string
6142 * size to a multiple of 8. However, we must guarantee the tail end is
6143 * zero'd out to avoid leaking random bits to userspace.
6145 size
= strlen(name
)+1;
6146 while (!IS_ALIGNED(size
, sizeof(u64
)))
6147 name
[size
++] = '\0';
6149 mmap_event
->file_name
= name
;
6150 mmap_event
->file_size
= size
;
6151 mmap_event
->maj
= maj
;
6152 mmap_event
->min
= min
;
6153 mmap_event
->ino
= ino
;
6154 mmap_event
->ino_generation
= gen
;
6155 mmap_event
->prot
= prot
;
6156 mmap_event
->flags
= flags
;
6158 if (!(vma
->vm_flags
& VM_EXEC
))
6159 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6161 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6163 perf_event_aux(perf_event_mmap_output
,
6170 void perf_event_mmap(struct vm_area_struct
*vma
)
6172 struct perf_mmap_event mmap_event
;
6174 if (!atomic_read(&nr_mmap_events
))
6177 mmap_event
= (struct perf_mmap_event
){
6183 .type
= PERF_RECORD_MMAP
,
6184 .misc
= PERF_RECORD_MISC_USER
,
6189 .start
= vma
->vm_start
,
6190 .len
= vma
->vm_end
- vma
->vm_start
,
6191 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6193 /* .maj (attr_mmap2 only) */
6194 /* .min (attr_mmap2 only) */
6195 /* .ino (attr_mmap2 only) */
6196 /* .ino_generation (attr_mmap2 only) */
6197 /* .prot (attr_mmap2 only) */
6198 /* .flags (attr_mmap2 only) */
6201 perf_event_mmap_event(&mmap_event
);
6204 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6205 unsigned long size
, u64 flags
)
6207 struct perf_output_handle handle
;
6208 struct perf_sample_data sample
;
6209 struct perf_aux_event
{
6210 struct perf_event_header header
;
6216 .type
= PERF_RECORD_AUX
,
6218 .size
= sizeof(rec
),
6226 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6227 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6232 perf_output_put(&handle
, rec
);
6233 perf_event__output_id_sample(event
, &handle
, &sample
);
6235 perf_output_end(&handle
);
6239 * Lost/dropped samples logging
6241 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6243 struct perf_output_handle handle
;
6244 struct perf_sample_data sample
;
6248 struct perf_event_header header
;
6250 } lost_samples_event
= {
6252 .type
= PERF_RECORD_LOST_SAMPLES
,
6254 .size
= sizeof(lost_samples_event
),
6259 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6261 ret
= perf_output_begin(&handle
, event
,
6262 lost_samples_event
.header
.size
);
6266 perf_output_put(&handle
, lost_samples_event
);
6267 perf_event__output_id_sample(event
, &handle
, &sample
);
6268 perf_output_end(&handle
);
6272 * context_switch tracking
6275 struct perf_switch_event
{
6276 struct task_struct
*task
;
6277 struct task_struct
*next_prev
;
6280 struct perf_event_header header
;
6286 static int perf_event_switch_match(struct perf_event
*event
)
6288 return event
->attr
.context_switch
;
6291 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6293 struct perf_switch_event
*se
= data
;
6294 struct perf_output_handle handle
;
6295 struct perf_sample_data sample
;
6298 if (!perf_event_switch_match(event
))
6301 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6302 if (event
->ctx
->task
) {
6303 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6304 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6306 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6307 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6308 se
->event_id
.next_prev_pid
=
6309 perf_event_pid(event
, se
->next_prev
);
6310 se
->event_id
.next_prev_tid
=
6311 perf_event_tid(event
, se
->next_prev
);
6314 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6316 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6320 if (event
->ctx
->task
)
6321 perf_output_put(&handle
, se
->event_id
.header
);
6323 perf_output_put(&handle
, se
->event_id
);
6325 perf_event__output_id_sample(event
, &handle
, &sample
);
6327 perf_output_end(&handle
);
6330 static void perf_event_switch(struct task_struct
*task
,
6331 struct task_struct
*next_prev
, bool sched_in
)
6333 struct perf_switch_event switch_event
;
6335 /* N.B. caller checks nr_switch_events != 0 */
6337 switch_event
= (struct perf_switch_event
){
6339 .next_prev
= next_prev
,
6343 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6346 /* .next_prev_pid */
6347 /* .next_prev_tid */
6351 perf_event_aux(perf_event_switch_output
,
6357 * IRQ throttle logging
6360 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6362 struct perf_output_handle handle
;
6363 struct perf_sample_data sample
;
6367 struct perf_event_header header
;
6371 } throttle_event
= {
6373 .type
= PERF_RECORD_THROTTLE
,
6375 .size
= sizeof(throttle_event
),
6377 .time
= perf_event_clock(event
),
6378 .id
= primary_event_id(event
),
6379 .stream_id
= event
->id
,
6383 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6385 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6387 ret
= perf_output_begin(&handle
, event
,
6388 throttle_event
.header
.size
);
6392 perf_output_put(&handle
, throttle_event
);
6393 perf_event__output_id_sample(event
, &handle
, &sample
);
6394 perf_output_end(&handle
);
6397 static void perf_log_itrace_start(struct perf_event
*event
)
6399 struct perf_output_handle handle
;
6400 struct perf_sample_data sample
;
6401 struct perf_aux_event
{
6402 struct perf_event_header header
;
6409 event
= event
->parent
;
6411 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6412 event
->hw
.itrace_started
)
6415 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6416 rec
.header
.misc
= 0;
6417 rec
.header
.size
= sizeof(rec
);
6418 rec
.pid
= perf_event_pid(event
, current
);
6419 rec
.tid
= perf_event_tid(event
, current
);
6421 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6422 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6427 perf_output_put(&handle
, rec
);
6428 perf_event__output_id_sample(event
, &handle
, &sample
);
6430 perf_output_end(&handle
);
6434 * Generic event overflow handling, sampling.
6437 static int __perf_event_overflow(struct perf_event
*event
,
6438 int throttle
, struct perf_sample_data
*data
,
6439 struct pt_regs
*regs
)
6441 int events
= atomic_read(&event
->event_limit
);
6442 struct hw_perf_event
*hwc
= &event
->hw
;
6447 * Non-sampling counters might still use the PMI to fold short
6448 * hardware counters, ignore those.
6450 if (unlikely(!is_sampling_event(event
)))
6453 seq
= __this_cpu_read(perf_throttled_seq
);
6454 if (seq
!= hwc
->interrupts_seq
) {
6455 hwc
->interrupts_seq
= seq
;
6456 hwc
->interrupts
= 1;
6459 if (unlikely(throttle
6460 && hwc
->interrupts
>= max_samples_per_tick
)) {
6461 __this_cpu_inc(perf_throttled_count
);
6462 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
6463 hwc
->interrupts
= MAX_INTERRUPTS
;
6464 perf_log_throttle(event
, 0);
6469 if (event
->attr
.freq
) {
6470 u64 now
= perf_clock();
6471 s64 delta
= now
- hwc
->freq_time_stamp
;
6473 hwc
->freq_time_stamp
= now
;
6475 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6476 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6480 * XXX event_limit might not quite work as expected on inherited
6484 event
->pending_kill
= POLL_IN
;
6485 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6487 event
->pending_kill
= POLL_HUP
;
6488 event
->pending_disable
= 1;
6489 irq_work_queue(&event
->pending
);
6492 if (event
->overflow_handler
)
6493 event
->overflow_handler(event
, data
, regs
);
6495 perf_event_output(event
, data
, regs
);
6497 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6498 event
->pending_wakeup
= 1;
6499 irq_work_queue(&event
->pending
);
6505 int perf_event_overflow(struct perf_event
*event
,
6506 struct perf_sample_data
*data
,
6507 struct pt_regs
*regs
)
6509 return __perf_event_overflow(event
, 1, data
, regs
);
6513 * Generic software event infrastructure
6516 struct swevent_htable
{
6517 struct swevent_hlist
*swevent_hlist
;
6518 struct mutex hlist_mutex
;
6521 /* Recursion avoidance in each contexts */
6522 int recursion
[PERF_NR_CONTEXTS
];
6525 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6528 * We directly increment event->count and keep a second value in
6529 * event->hw.period_left to count intervals. This period event
6530 * is kept in the range [-sample_period, 0] so that we can use the
6534 u64
perf_swevent_set_period(struct perf_event
*event
)
6536 struct hw_perf_event
*hwc
= &event
->hw
;
6537 u64 period
= hwc
->last_period
;
6541 hwc
->last_period
= hwc
->sample_period
;
6544 old
= val
= local64_read(&hwc
->period_left
);
6548 nr
= div64_u64(period
+ val
, period
);
6549 offset
= nr
* period
;
6551 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6557 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6558 struct perf_sample_data
*data
,
6559 struct pt_regs
*regs
)
6561 struct hw_perf_event
*hwc
= &event
->hw
;
6565 overflow
= perf_swevent_set_period(event
);
6567 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6570 for (; overflow
; overflow
--) {
6571 if (__perf_event_overflow(event
, throttle
,
6574 * We inhibit the overflow from happening when
6575 * hwc->interrupts == MAX_INTERRUPTS.
6583 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6584 struct perf_sample_data
*data
,
6585 struct pt_regs
*regs
)
6587 struct hw_perf_event
*hwc
= &event
->hw
;
6589 local64_add(nr
, &event
->count
);
6594 if (!is_sampling_event(event
))
6597 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6599 return perf_swevent_overflow(event
, 1, data
, regs
);
6601 data
->period
= event
->hw
.last_period
;
6603 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6604 return perf_swevent_overflow(event
, 1, data
, regs
);
6606 if (local64_add_negative(nr
, &hwc
->period_left
))
6609 perf_swevent_overflow(event
, 0, data
, regs
);
6612 static int perf_exclude_event(struct perf_event
*event
,
6613 struct pt_regs
*regs
)
6615 if (event
->hw
.state
& PERF_HES_STOPPED
)
6619 if (event
->attr
.exclude_user
&& user_mode(regs
))
6622 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6629 static int perf_swevent_match(struct perf_event
*event
,
6630 enum perf_type_id type
,
6632 struct perf_sample_data
*data
,
6633 struct pt_regs
*regs
)
6635 if (event
->attr
.type
!= type
)
6638 if (event
->attr
.config
!= event_id
)
6641 if (perf_exclude_event(event
, regs
))
6647 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6649 u64 val
= event_id
| (type
<< 32);
6651 return hash_64(val
, SWEVENT_HLIST_BITS
);
6654 static inline struct hlist_head
*
6655 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6657 u64 hash
= swevent_hash(type
, event_id
);
6659 return &hlist
->heads
[hash
];
6662 /* For the read side: events when they trigger */
6663 static inline struct hlist_head
*
6664 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6666 struct swevent_hlist
*hlist
;
6668 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6672 return __find_swevent_head(hlist
, type
, event_id
);
6675 /* For the event head insertion and removal in the hlist */
6676 static inline struct hlist_head
*
6677 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6679 struct swevent_hlist
*hlist
;
6680 u32 event_id
= event
->attr
.config
;
6681 u64 type
= event
->attr
.type
;
6684 * Event scheduling is always serialized against hlist allocation
6685 * and release. Which makes the protected version suitable here.
6686 * The context lock guarantees that.
6688 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6689 lockdep_is_held(&event
->ctx
->lock
));
6693 return __find_swevent_head(hlist
, type
, event_id
);
6696 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6698 struct perf_sample_data
*data
,
6699 struct pt_regs
*regs
)
6701 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6702 struct perf_event
*event
;
6703 struct hlist_head
*head
;
6706 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6710 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6711 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6712 perf_swevent_event(event
, nr
, data
, regs
);
6718 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6720 int perf_swevent_get_recursion_context(void)
6722 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6724 return get_recursion_context(swhash
->recursion
);
6726 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6728 inline void perf_swevent_put_recursion_context(int rctx
)
6730 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6732 put_recursion_context(swhash
->recursion
, rctx
);
6735 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6737 struct perf_sample_data data
;
6739 if (WARN_ON_ONCE(!regs
))
6742 perf_sample_data_init(&data
, addr
, 0);
6743 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6746 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6750 preempt_disable_notrace();
6751 rctx
= perf_swevent_get_recursion_context();
6752 if (unlikely(rctx
< 0))
6755 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6757 perf_swevent_put_recursion_context(rctx
);
6759 preempt_enable_notrace();
6762 static void perf_swevent_read(struct perf_event
*event
)
6766 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6768 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6769 struct hw_perf_event
*hwc
= &event
->hw
;
6770 struct hlist_head
*head
;
6772 if (is_sampling_event(event
)) {
6773 hwc
->last_period
= hwc
->sample_period
;
6774 perf_swevent_set_period(event
);
6777 hwc
->state
= !(flags
& PERF_EF_START
);
6779 head
= find_swevent_head(swhash
, event
);
6780 if (WARN_ON_ONCE(!head
))
6783 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6784 perf_event_update_userpage(event
);
6789 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6791 hlist_del_rcu(&event
->hlist_entry
);
6794 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6796 event
->hw
.state
= 0;
6799 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6801 event
->hw
.state
= PERF_HES_STOPPED
;
6804 /* Deref the hlist from the update side */
6805 static inline struct swevent_hlist
*
6806 swevent_hlist_deref(struct swevent_htable
*swhash
)
6808 return rcu_dereference_protected(swhash
->swevent_hlist
,
6809 lockdep_is_held(&swhash
->hlist_mutex
));
6812 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6814 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6819 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6820 kfree_rcu(hlist
, rcu_head
);
6823 static void swevent_hlist_put_cpu(int cpu
)
6825 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6827 mutex_lock(&swhash
->hlist_mutex
);
6829 if (!--swhash
->hlist_refcount
)
6830 swevent_hlist_release(swhash
);
6832 mutex_unlock(&swhash
->hlist_mutex
);
6835 static void swevent_hlist_put(void)
6839 for_each_possible_cpu(cpu
)
6840 swevent_hlist_put_cpu(cpu
);
6843 static int swevent_hlist_get_cpu(int cpu
)
6845 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6848 mutex_lock(&swhash
->hlist_mutex
);
6849 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6850 struct swevent_hlist
*hlist
;
6852 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6857 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6859 swhash
->hlist_refcount
++;
6861 mutex_unlock(&swhash
->hlist_mutex
);
6866 static int swevent_hlist_get(void)
6868 int err
, cpu
, failed_cpu
;
6871 for_each_possible_cpu(cpu
) {
6872 err
= swevent_hlist_get_cpu(cpu
);
6882 for_each_possible_cpu(cpu
) {
6883 if (cpu
== failed_cpu
)
6885 swevent_hlist_put_cpu(cpu
);
6892 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6894 static void sw_perf_event_destroy(struct perf_event
*event
)
6896 u64 event_id
= event
->attr
.config
;
6898 WARN_ON(event
->parent
);
6900 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6901 swevent_hlist_put();
6904 static int perf_swevent_init(struct perf_event
*event
)
6906 u64 event_id
= event
->attr
.config
;
6908 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6912 * no branch sampling for software events
6914 if (has_branch_stack(event
))
6918 case PERF_COUNT_SW_CPU_CLOCK
:
6919 case PERF_COUNT_SW_TASK_CLOCK
:
6926 if (event_id
>= PERF_COUNT_SW_MAX
)
6929 if (!event
->parent
) {
6932 err
= swevent_hlist_get();
6936 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6937 event
->destroy
= sw_perf_event_destroy
;
6943 static struct pmu perf_swevent
= {
6944 .task_ctx_nr
= perf_sw_context
,
6946 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6948 .event_init
= perf_swevent_init
,
6949 .add
= perf_swevent_add
,
6950 .del
= perf_swevent_del
,
6951 .start
= perf_swevent_start
,
6952 .stop
= perf_swevent_stop
,
6953 .read
= perf_swevent_read
,
6956 #ifdef CONFIG_EVENT_TRACING
6958 static int perf_tp_filter_match(struct perf_event
*event
,
6959 struct perf_sample_data
*data
)
6961 void *record
= data
->raw
->data
;
6963 /* only top level events have filters set */
6965 event
= event
->parent
;
6967 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6972 static int perf_tp_event_match(struct perf_event
*event
,
6973 struct perf_sample_data
*data
,
6974 struct pt_regs
*regs
)
6976 if (event
->hw
.state
& PERF_HES_STOPPED
)
6979 * All tracepoints are from kernel-space.
6981 if (event
->attr
.exclude_kernel
)
6984 if (!perf_tp_filter_match(event
, data
))
6990 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6991 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6992 struct task_struct
*task
)
6994 struct perf_sample_data data
;
6995 struct perf_event
*event
;
6997 struct perf_raw_record raw
= {
7002 perf_sample_data_init(&data
, addr
, 0);
7005 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7006 if (perf_tp_event_match(event
, &data
, regs
))
7007 perf_swevent_event(event
, count
, &data
, regs
);
7011 * If we got specified a target task, also iterate its context and
7012 * deliver this event there too.
7014 if (task
&& task
!= current
) {
7015 struct perf_event_context
*ctx
;
7016 struct trace_entry
*entry
= record
;
7019 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7023 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7024 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7026 if (event
->attr
.config
!= entry
->type
)
7028 if (perf_tp_event_match(event
, &data
, regs
))
7029 perf_swevent_event(event
, count
, &data
, regs
);
7035 perf_swevent_put_recursion_context(rctx
);
7037 EXPORT_SYMBOL_GPL(perf_tp_event
);
7039 static void tp_perf_event_destroy(struct perf_event
*event
)
7041 perf_trace_destroy(event
);
7044 static int perf_tp_event_init(struct perf_event
*event
)
7048 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7052 * no branch sampling for tracepoint events
7054 if (has_branch_stack(event
))
7057 err
= perf_trace_init(event
);
7061 event
->destroy
= tp_perf_event_destroy
;
7066 static struct pmu perf_tracepoint
= {
7067 .task_ctx_nr
= perf_sw_context
,
7069 .event_init
= perf_tp_event_init
,
7070 .add
= perf_trace_add
,
7071 .del
= perf_trace_del
,
7072 .start
= perf_swevent_start
,
7073 .stop
= perf_swevent_stop
,
7074 .read
= perf_swevent_read
,
7077 static inline void perf_tp_register(void)
7079 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7082 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7087 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7090 filter_str
= strndup_user(arg
, PAGE_SIZE
);
7091 if (IS_ERR(filter_str
))
7092 return PTR_ERR(filter_str
);
7094 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
7100 static void perf_event_free_filter(struct perf_event
*event
)
7102 ftrace_profile_free_filter(event
);
7105 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7107 struct bpf_prog
*prog
;
7109 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7112 if (event
->tp_event
->prog
)
7115 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
7116 /* bpf programs can only be attached to u/kprobes */
7119 prog
= bpf_prog_get(prog_fd
);
7121 return PTR_ERR(prog
);
7123 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7124 /* valid fd, but invalid bpf program type */
7129 event
->tp_event
->prog
= prog
;
7134 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7136 struct bpf_prog
*prog
;
7138 if (!event
->tp_event
)
7141 prog
= event
->tp_event
->prog
;
7143 event
->tp_event
->prog
= NULL
;
7150 static inline void perf_tp_register(void)
7154 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7159 static void perf_event_free_filter(struct perf_event
*event
)
7163 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7168 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7171 #endif /* CONFIG_EVENT_TRACING */
7173 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7174 void perf_bp_event(struct perf_event
*bp
, void *data
)
7176 struct perf_sample_data sample
;
7177 struct pt_regs
*regs
= data
;
7179 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7181 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7182 perf_swevent_event(bp
, 1, &sample
, regs
);
7187 * hrtimer based swevent callback
7190 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7192 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7193 struct perf_sample_data data
;
7194 struct pt_regs
*regs
;
7195 struct perf_event
*event
;
7198 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7200 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7201 return HRTIMER_NORESTART
;
7203 event
->pmu
->read(event
);
7205 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7206 regs
= get_irq_regs();
7208 if (regs
&& !perf_exclude_event(event
, regs
)) {
7209 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7210 if (__perf_event_overflow(event
, 1, &data
, regs
))
7211 ret
= HRTIMER_NORESTART
;
7214 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7215 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7220 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7222 struct hw_perf_event
*hwc
= &event
->hw
;
7225 if (!is_sampling_event(event
))
7228 period
= local64_read(&hwc
->period_left
);
7233 local64_set(&hwc
->period_left
, 0);
7235 period
= max_t(u64
, 10000, hwc
->sample_period
);
7237 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7238 HRTIMER_MODE_REL_PINNED
);
7241 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7243 struct hw_perf_event
*hwc
= &event
->hw
;
7245 if (is_sampling_event(event
)) {
7246 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7247 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7249 hrtimer_cancel(&hwc
->hrtimer
);
7253 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7255 struct hw_perf_event
*hwc
= &event
->hw
;
7257 if (!is_sampling_event(event
))
7260 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7261 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7264 * Since hrtimers have a fixed rate, we can do a static freq->period
7265 * mapping and avoid the whole period adjust feedback stuff.
7267 if (event
->attr
.freq
) {
7268 long freq
= event
->attr
.sample_freq
;
7270 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7271 hwc
->sample_period
= event
->attr
.sample_period
;
7272 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7273 hwc
->last_period
= hwc
->sample_period
;
7274 event
->attr
.freq
= 0;
7279 * Software event: cpu wall time clock
7282 static void cpu_clock_event_update(struct perf_event
*event
)
7287 now
= local_clock();
7288 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7289 local64_add(now
- prev
, &event
->count
);
7292 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7294 local64_set(&event
->hw
.prev_count
, local_clock());
7295 perf_swevent_start_hrtimer(event
);
7298 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7300 perf_swevent_cancel_hrtimer(event
);
7301 cpu_clock_event_update(event
);
7304 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7306 if (flags
& PERF_EF_START
)
7307 cpu_clock_event_start(event
, flags
);
7308 perf_event_update_userpage(event
);
7313 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7315 cpu_clock_event_stop(event
, flags
);
7318 static void cpu_clock_event_read(struct perf_event
*event
)
7320 cpu_clock_event_update(event
);
7323 static int cpu_clock_event_init(struct perf_event
*event
)
7325 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7328 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7332 * no branch sampling for software events
7334 if (has_branch_stack(event
))
7337 perf_swevent_init_hrtimer(event
);
7342 static struct pmu perf_cpu_clock
= {
7343 .task_ctx_nr
= perf_sw_context
,
7345 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7347 .event_init
= cpu_clock_event_init
,
7348 .add
= cpu_clock_event_add
,
7349 .del
= cpu_clock_event_del
,
7350 .start
= cpu_clock_event_start
,
7351 .stop
= cpu_clock_event_stop
,
7352 .read
= cpu_clock_event_read
,
7356 * Software event: task time clock
7359 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7364 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7366 local64_add(delta
, &event
->count
);
7369 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7371 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7372 perf_swevent_start_hrtimer(event
);
7375 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7377 perf_swevent_cancel_hrtimer(event
);
7378 task_clock_event_update(event
, event
->ctx
->time
);
7381 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7383 if (flags
& PERF_EF_START
)
7384 task_clock_event_start(event
, flags
);
7385 perf_event_update_userpage(event
);
7390 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7392 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7395 static void task_clock_event_read(struct perf_event
*event
)
7397 u64 now
= perf_clock();
7398 u64 delta
= now
- event
->ctx
->timestamp
;
7399 u64 time
= event
->ctx
->time
+ delta
;
7401 task_clock_event_update(event
, time
);
7404 static int task_clock_event_init(struct perf_event
*event
)
7406 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7409 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7413 * no branch sampling for software events
7415 if (has_branch_stack(event
))
7418 perf_swevent_init_hrtimer(event
);
7423 static struct pmu perf_task_clock
= {
7424 .task_ctx_nr
= perf_sw_context
,
7426 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7428 .event_init
= task_clock_event_init
,
7429 .add
= task_clock_event_add
,
7430 .del
= task_clock_event_del
,
7431 .start
= task_clock_event_start
,
7432 .stop
= task_clock_event_stop
,
7433 .read
= task_clock_event_read
,
7436 static void perf_pmu_nop_void(struct pmu
*pmu
)
7440 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7444 static int perf_pmu_nop_int(struct pmu
*pmu
)
7449 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7451 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7453 __this_cpu_write(nop_txn_flags
, flags
);
7455 if (flags
& ~PERF_PMU_TXN_ADD
)
7458 perf_pmu_disable(pmu
);
7461 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7463 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7465 __this_cpu_write(nop_txn_flags
, 0);
7467 if (flags
& ~PERF_PMU_TXN_ADD
)
7470 perf_pmu_enable(pmu
);
7474 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7476 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7478 __this_cpu_write(nop_txn_flags
, 0);
7480 if (flags
& ~PERF_PMU_TXN_ADD
)
7483 perf_pmu_enable(pmu
);
7486 static int perf_event_idx_default(struct perf_event
*event
)
7492 * Ensures all contexts with the same task_ctx_nr have the same
7493 * pmu_cpu_context too.
7495 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7502 list_for_each_entry(pmu
, &pmus
, entry
) {
7503 if (pmu
->task_ctx_nr
== ctxn
)
7504 return pmu
->pmu_cpu_context
;
7510 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7514 for_each_possible_cpu(cpu
) {
7515 struct perf_cpu_context
*cpuctx
;
7517 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7519 if (cpuctx
->unique_pmu
== old_pmu
)
7520 cpuctx
->unique_pmu
= pmu
;
7524 static void free_pmu_context(struct pmu
*pmu
)
7528 mutex_lock(&pmus_lock
);
7530 * Like a real lame refcount.
7532 list_for_each_entry(i
, &pmus
, entry
) {
7533 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7534 update_pmu_context(i
, pmu
);
7539 free_percpu(pmu
->pmu_cpu_context
);
7541 mutex_unlock(&pmus_lock
);
7543 static struct idr pmu_idr
;
7546 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7548 struct pmu
*pmu
= dev_get_drvdata(dev
);
7550 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7552 static DEVICE_ATTR_RO(type
);
7555 perf_event_mux_interval_ms_show(struct device
*dev
,
7556 struct device_attribute
*attr
,
7559 struct pmu
*pmu
= dev_get_drvdata(dev
);
7561 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7564 static DEFINE_MUTEX(mux_interval_mutex
);
7567 perf_event_mux_interval_ms_store(struct device
*dev
,
7568 struct device_attribute
*attr
,
7569 const char *buf
, size_t count
)
7571 struct pmu
*pmu
= dev_get_drvdata(dev
);
7572 int timer
, cpu
, ret
;
7574 ret
= kstrtoint(buf
, 0, &timer
);
7581 /* same value, noting to do */
7582 if (timer
== pmu
->hrtimer_interval_ms
)
7585 mutex_lock(&mux_interval_mutex
);
7586 pmu
->hrtimer_interval_ms
= timer
;
7588 /* update all cpuctx for this PMU */
7590 for_each_online_cpu(cpu
) {
7591 struct perf_cpu_context
*cpuctx
;
7592 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7593 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7595 cpu_function_call(cpu
,
7596 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7599 mutex_unlock(&mux_interval_mutex
);
7603 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7605 static struct attribute
*pmu_dev_attrs
[] = {
7606 &dev_attr_type
.attr
,
7607 &dev_attr_perf_event_mux_interval_ms
.attr
,
7610 ATTRIBUTE_GROUPS(pmu_dev
);
7612 static int pmu_bus_running
;
7613 static struct bus_type pmu_bus
= {
7614 .name
= "event_source",
7615 .dev_groups
= pmu_dev_groups
,
7618 static void pmu_dev_release(struct device
*dev
)
7623 static int pmu_dev_alloc(struct pmu
*pmu
)
7627 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7631 pmu
->dev
->groups
= pmu
->attr_groups
;
7632 device_initialize(pmu
->dev
);
7633 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7637 dev_set_drvdata(pmu
->dev
, pmu
);
7638 pmu
->dev
->bus
= &pmu_bus
;
7639 pmu
->dev
->release
= pmu_dev_release
;
7640 ret
= device_add(pmu
->dev
);
7648 put_device(pmu
->dev
);
7652 static struct lock_class_key cpuctx_mutex
;
7653 static struct lock_class_key cpuctx_lock
;
7655 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7659 mutex_lock(&pmus_lock
);
7661 pmu
->pmu_disable_count
= alloc_percpu(int);
7662 if (!pmu
->pmu_disable_count
)
7671 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7679 if (pmu_bus_running
) {
7680 ret
= pmu_dev_alloc(pmu
);
7686 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7687 if (pmu
->pmu_cpu_context
)
7688 goto got_cpu_context
;
7691 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7692 if (!pmu
->pmu_cpu_context
)
7695 for_each_possible_cpu(cpu
) {
7696 struct perf_cpu_context
*cpuctx
;
7698 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7699 __perf_event_init_context(&cpuctx
->ctx
);
7700 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7701 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7702 cpuctx
->ctx
.pmu
= pmu
;
7704 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7706 cpuctx
->unique_pmu
= pmu
;
7710 if (!pmu
->start_txn
) {
7711 if (pmu
->pmu_enable
) {
7713 * If we have pmu_enable/pmu_disable calls, install
7714 * transaction stubs that use that to try and batch
7715 * hardware accesses.
7717 pmu
->start_txn
= perf_pmu_start_txn
;
7718 pmu
->commit_txn
= perf_pmu_commit_txn
;
7719 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7721 pmu
->start_txn
= perf_pmu_nop_txn
;
7722 pmu
->commit_txn
= perf_pmu_nop_int
;
7723 pmu
->cancel_txn
= perf_pmu_nop_void
;
7727 if (!pmu
->pmu_enable
) {
7728 pmu
->pmu_enable
= perf_pmu_nop_void
;
7729 pmu
->pmu_disable
= perf_pmu_nop_void
;
7732 if (!pmu
->event_idx
)
7733 pmu
->event_idx
= perf_event_idx_default
;
7735 list_add_rcu(&pmu
->entry
, &pmus
);
7736 atomic_set(&pmu
->exclusive_cnt
, 0);
7739 mutex_unlock(&pmus_lock
);
7744 device_del(pmu
->dev
);
7745 put_device(pmu
->dev
);
7748 if (pmu
->type
>= PERF_TYPE_MAX
)
7749 idr_remove(&pmu_idr
, pmu
->type
);
7752 free_percpu(pmu
->pmu_disable_count
);
7755 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7757 void perf_pmu_unregister(struct pmu
*pmu
)
7759 mutex_lock(&pmus_lock
);
7760 list_del_rcu(&pmu
->entry
);
7761 mutex_unlock(&pmus_lock
);
7764 * We dereference the pmu list under both SRCU and regular RCU, so
7765 * synchronize against both of those.
7767 synchronize_srcu(&pmus_srcu
);
7770 free_percpu(pmu
->pmu_disable_count
);
7771 if (pmu
->type
>= PERF_TYPE_MAX
)
7772 idr_remove(&pmu_idr
, pmu
->type
);
7773 device_del(pmu
->dev
);
7774 put_device(pmu
->dev
);
7775 free_pmu_context(pmu
);
7777 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7779 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7781 struct perf_event_context
*ctx
= NULL
;
7784 if (!try_module_get(pmu
->module
))
7787 if (event
->group_leader
!= event
) {
7789 * This ctx->mutex can nest when we're called through
7790 * inheritance. See the perf_event_ctx_lock_nested() comment.
7792 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7793 SINGLE_DEPTH_NESTING
);
7798 ret
= pmu
->event_init(event
);
7801 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7804 module_put(pmu
->module
);
7809 static struct pmu
*perf_init_event(struct perf_event
*event
)
7811 struct pmu
*pmu
= NULL
;
7815 idx
= srcu_read_lock(&pmus_srcu
);
7818 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7821 ret
= perf_try_init_event(pmu
, event
);
7827 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7828 ret
= perf_try_init_event(pmu
, event
);
7832 if (ret
!= -ENOENT
) {
7837 pmu
= ERR_PTR(-ENOENT
);
7839 srcu_read_unlock(&pmus_srcu
, idx
);
7844 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7849 if (is_cgroup_event(event
))
7850 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7853 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
7854 static void account_freq_event_nohz(void)
7856 #ifdef CONFIG_NO_HZ_FULL
7857 /* Lock so we don't race with concurrent unaccount */
7858 spin_lock(&nr_freq_lock
);
7859 if (atomic_inc_return(&nr_freq_events
) == 1)
7860 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
7861 spin_unlock(&nr_freq_lock
);
7865 static void account_freq_event(void)
7867 if (tick_nohz_full_enabled())
7868 account_freq_event_nohz();
7870 atomic_inc(&nr_freq_events
);
7874 static void account_event(struct perf_event
*event
)
7881 if (event
->attach_state
& PERF_ATTACH_TASK
)
7883 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7884 atomic_inc(&nr_mmap_events
);
7885 if (event
->attr
.comm
)
7886 atomic_inc(&nr_comm_events
);
7887 if (event
->attr
.task
)
7888 atomic_inc(&nr_task_events
);
7889 if (event
->attr
.freq
)
7890 account_freq_event();
7891 if (event
->attr
.context_switch
) {
7892 atomic_inc(&nr_switch_events
);
7895 if (has_branch_stack(event
))
7897 if (is_cgroup_event(event
))
7901 if (atomic_inc_not_zero(&perf_sched_count
))
7904 mutex_lock(&perf_sched_mutex
);
7905 if (!atomic_read(&perf_sched_count
)) {
7906 static_branch_enable(&perf_sched_events
);
7908 * Guarantee that all CPUs observe they key change and
7909 * call the perf scheduling hooks before proceeding to
7910 * install events that need them.
7912 synchronize_sched();
7915 * Now that we have waited for the sync_sched(), allow further
7916 * increments to by-pass the mutex.
7918 atomic_inc(&perf_sched_count
);
7919 mutex_unlock(&perf_sched_mutex
);
7923 account_event_cpu(event
, event
->cpu
);
7927 * Allocate and initialize a event structure
7929 static struct perf_event
*
7930 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7931 struct task_struct
*task
,
7932 struct perf_event
*group_leader
,
7933 struct perf_event
*parent_event
,
7934 perf_overflow_handler_t overflow_handler
,
7935 void *context
, int cgroup_fd
)
7938 struct perf_event
*event
;
7939 struct hw_perf_event
*hwc
;
7942 if ((unsigned)cpu
>= nr_cpu_ids
) {
7943 if (!task
|| cpu
!= -1)
7944 return ERR_PTR(-EINVAL
);
7947 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7949 return ERR_PTR(-ENOMEM
);
7952 * Single events are their own group leaders, with an
7953 * empty sibling list:
7956 group_leader
= event
;
7958 mutex_init(&event
->child_mutex
);
7959 INIT_LIST_HEAD(&event
->child_list
);
7961 INIT_LIST_HEAD(&event
->group_entry
);
7962 INIT_LIST_HEAD(&event
->event_entry
);
7963 INIT_LIST_HEAD(&event
->sibling_list
);
7964 INIT_LIST_HEAD(&event
->rb_entry
);
7965 INIT_LIST_HEAD(&event
->active_entry
);
7966 INIT_HLIST_NODE(&event
->hlist_entry
);
7969 init_waitqueue_head(&event
->waitq
);
7970 init_irq_work(&event
->pending
, perf_pending_event
);
7972 mutex_init(&event
->mmap_mutex
);
7974 atomic_long_set(&event
->refcount
, 1);
7976 event
->attr
= *attr
;
7977 event
->group_leader
= group_leader
;
7981 event
->parent
= parent_event
;
7983 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7984 event
->id
= atomic64_inc_return(&perf_event_id
);
7986 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7989 event
->attach_state
= PERF_ATTACH_TASK
;
7991 * XXX pmu::event_init needs to know what task to account to
7992 * and we cannot use the ctx information because we need the
7993 * pmu before we get a ctx.
7995 event
->hw
.target
= task
;
7998 event
->clock
= &local_clock
;
8000 event
->clock
= parent_event
->clock
;
8002 if (!overflow_handler
&& parent_event
) {
8003 overflow_handler
= parent_event
->overflow_handler
;
8004 context
= parent_event
->overflow_handler_context
;
8007 event
->overflow_handler
= overflow_handler
;
8008 event
->overflow_handler_context
= context
;
8010 perf_event__state_init(event
);
8015 hwc
->sample_period
= attr
->sample_period
;
8016 if (attr
->freq
&& attr
->sample_freq
)
8017 hwc
->sample_period
= 1;
8018 hwc
->last_period
= hwc
->sample_period
;
8020 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8023 * we currently do not support PERF_FORMAT_GROUP on inherited events
8025 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
8028 if (!has_branch_stack(event
))
8029 event
->attr
.branch_sample_type
= 0;
8031 if (cgroup_fd
!= -1) {
8032 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
8037 pmu
= perf_init_event(event
);
8040 else if (IS_ERR(pmu
)) {
8045 err
= exclusive_event_init(event
);
8049 if (!event
->parent
) {
8050 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
8051 err
= get_callchain_buffers();
8057 /* symmetric to unaccount_event() in _free_event() */
8058 account_event(event
);
8063 exclusive_event_destroy(event
);
8067 event
->destroy(event
);
8068 module_put(pmu
->module
);
8070 if (is_cgroup_event(event
))
8071 perf_detach_cgroup(event
);
8073 put_pid_ns(event
->ns
);
8076 return ERR_PTR(err
);
8079 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
8080 struct perf_event_attr
*attr
)
8085 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
8089 * zero the full structure, so that a short copy will be nice.
8091 memset(attr
, 0, sizeof(*attr
));
8093 ret
= get_user(size
, &uattr
->size
);
8097 if (size
> PAGE_SIZE
) /* silly large */
8100 if (!size
) /* abi compat */
8101 size
= PERF_ATTR_SIZE_VER0
;
8103 if (size
< PERF_ATTR_SIZE_VER0
)
8107 * If we're handed a bigger struct than we know of,
8108 * ensure all the unknown bits are 0 - i.e. new
8109 * user-space does not rely on any kernel feature
8110 * extensions we dont know about yet.
8112 if (size
> sizeof(*attr
)) {
8113 unsigned char __user
*addr
;
8114 unsigned char __user
*end
;
8117 addr
= (void __user
*)uattr
+ sizeof(*attr
);
8118 end
= (void __user
*)uattr
+ size
;
8120 for (; addr
< end
; addr
++) {
8121 ret
= get_user(val
, addr
);
8127 size
= sizeof(*attr
);
8130 ret
= copy_from_user(attr
, uattr
, size
);
8134 if (attr
->__reserved_1
)
8137 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
8140 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
8143 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
8144 u64 mask
= attr
->branch_sample_type
;
8146 /* only using defined bits */
8147 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
8150 /* at least one branch bit must be set */
8151 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
8154 /* propagate priv level, when not set for branch */
8155 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
8157 /* exclude_kernel checked on syscall entry */
8158 if (!attr
->exclude_kernel
)
8159 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8161 if (!attr
->exclude_user
)
8162 mask
|= PERF_SAMPLE_BRANCH_USER
;
8164 if (!attr
->exclude_hv
)
8165 mask
|= PERF_SAMPLE_BRANCH_HV
;
8167 * adjust user setting (for HW filter setup)
8169 attr
->branch_sample_type
= mask
;
8171 /* privileged levels capture (kernel, hv): check permissions */
8172 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8173 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8177 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8178 ret
= perf_reg_validate(attr
->sample_regs_user
);
8183 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8184 if (!arch_perf_have_user_stack_dump())
8188 * We have __u32 type for the size, but so far
8189 * we can only use __u16 as maximum due to the
8190 * __u16 sample size limit.
8192 if (attr
->sample_stack_user
>= USHRT_MAX
)
8194 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8198 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8199 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8204 put_user(sizeof(*attr
), &uattr
->size
);
8210 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8212 struct ring_buffer
*rb
= NULL
;
8218 /* don't allow circular references */
8219 if (event
== output_event
)
8223 * Don't allow cross-cpu buffers
8225 if (output_event
->cpu
!= event
->cpu
)
8229 * If its not a per-cpu rb, it must be the same task.
8231 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8235 * Mixing clocks in the same buffer is trouble you don't need.
8237 if (output_event
->clock
!= event
->clock
)
8241 * If both events generate aux data, they must be on the same PMU
8243 if (has_aux(event
) && has_aux(output_event
) &&
8244 event
->pmu
!= output_event
->pmu
)
8248 mutex_lock(&event
->mmap_mutex
);
8249 /* Can't redirect output if we've got an active mmap() */
8250 if (atomic_read(&event
->mmap_count
))
8254 /* get the rb we want to redirect to */
8255 rb
= ring_buffer_get(output_event
);
8260 ring_buffer_attach(event
, rb
);
8264 mutex_unlock(&event
->mmap_mutex
);
8270 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8276 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8279 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8281 bool nmi_safe
= false;
8284 case CLOCK_MONOTONIC
:
8285 event
->clock
= &ktime_get_mono_fast_ns
;
8289 case CLOCK_MONOTONIC_RAW
:
8290 event
->clock
= &ktime_get_raw_fast_ns
;
8294 case CLOCK_REALTIME
:
8295 event
->clock
= &ktime_get_real_ns
;
8298 case CLOCK_BOOTTIME
:
8299 event
->clock
= &ktime_get_boot_ns
;
8303 event
->clock
= &ktime_get_tai_ns
;
8310 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8317 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8319 * @attr_uptr: event_id type attributes for monitoring/sampling
8322 * @group_fd: group leader event fd
8324 SYSCALL_DEFINE5(perf_event_open
,
8325 struct perf_event_attr __user
*, attr_uptr
,
8326 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8328 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8329 struct perf_event
*event
, *sibling
;
8330 struct perf_event_attr attr
;
8331 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8332 struct file
*event_file
= NULL
;
8333 struct fd group
= {NULL
, 0};
8334 struct task_struct
*task
= NULL
;
8339 int f_flags
= O_RDWR
;
8342 /* for future expandability... */
8343 if (flags
& ~PERF_FLAG_ALL
)
8346 err
= perf_copy_attr(attr_uptr
, &attr
);
8350 if (!attr
.exclude_kernel
) {
8351 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8356 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8359 if (attr
.sample_period
& (1ULL << 63))
8364 * In cgroup mode, the pid argument is used to pass the fd
8365 * opened to the cgroup directory in cgroupfs. The cpu argument
8366 * designates the cpu on which to monitor threads from that
8369 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8372 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8373 f_flags
|= O_CLOEXEC
;
8375 event_fd
= get_unused_fd_flags(f_flags
);
8379 if (group_fd
!= -1) {
8380 err
= perf_fget_light(group_fd
, &group
);
8383 group_leader
= group
.file
->private_data
;
8384 if (flags
& PERF_FLAG_FD_OUTPUT
)
8385 output_event
= group_leader
;
8386 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8387 group_leader
= NULL
;
8390 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8391 task
= find_lively_task_by_vpid(pid
);
8393 err
= PTR_ERR(task
);
8398 if (task
&& group_leader
&&
8399 group_leader
->attr
.inherit
!= attr
.inherit
) {
8406 if (flags
& PERF_FLAG_PID_CGROUP
)
8409 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8410 NULL
, NULL
, cgroup_fd
);
8411 if (IS_ERR(event
)) {
8412 err
= PTR_ERR(event
);
8416 if (is_sampling_event(event
)) {
8417 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8424 * Special case software events and allow them to be part of
8425 * any hardware group.
8429 if (attr
.use_clockid
) {
8430 err
= perf_event_set_clock(event
, attr
.clockid
);
8436 (is_software_event(event
) != is_software_event(group_leader
))) {
8437 if (is_software_event(event
)) {
8439 * If event and group_leader are not both a software
8440 * event, and event is, then group leader is not.
8442 * Allow the addition of software events to !software
8443 * groups, this is safe because software events never
8446 pmu
= group_leader
->pmu
;
8447 } else if (is_software_event(group_leader
) &&
8448 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8450 * In case the group is a pure software group, and we
8451 * try to add a hardware event, move the whole group to
8452 * the hardware context.
8459 * Get the target context (task or percpu):
8461 ctx
= find_get_context(pmu
, task
, event
);
8467 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8473 put_task_struct(task
);
8478 * Look up the group leader (we will attach this event to it):
8484 * Do not allow a recursive hierarchy (this new sibling
8485 * becoming part of another group-sibling):
8487 if (group_leader
->group_leader
!= group_leader
)
8490 /* All events in a group should have the same clock */
8491 if (group_leader
->clock
!= event
->clock
)
8495 * Do not allow to attach to a group in a different
8496 * task or CPU context:
8500 * Make sure we're both on the same task, or both
8503 if (group_leader
->ctx
->task
!= ctx
->task
)
8507 * Make sure we're both events for the same CPU;
8508 * grouping events for different CPUs is broken; since
8509 * you can never concurrently schedule them anyhow.
8511 if (group_leader
->cpu
!= event
->cpu
)
8514 if (group_leader
->ctx
!= ctx
)
8519 * Only a group leader can be exclusive or pinned
8521 if (attr
.exclusive
|| attr
.pinned
)
8526 err
= perf_event_set_output(event
, output_event
);
8531 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8533 if (IS_ERR(event_file
)) {
8534 err
= PTR_ERR(event_file
);
8539 gctx
= group_leader
->ctx
;
8540 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8541 if (gctx
->task
== TASK_TOMBSTONE
) {
8546 mutex_lock(&ctx
->mutex
);
8549 if (ctx
->task
== TASK_TOMBSTONE
) {
8554 if (!perf_event_validate_size(event
)) {
8560 * Must be under the same ctx::mutex as perf_install_in_context(),
8561 * because we need to serialize with concurrent event creation.
8563 if (!exclusive_event_installable(event
, ctx
)) {
8564 /* exclusive and group stuff are assumed mutually exclusive */
8565 WARN_ON_ONCE(move_group
);
8571 WARN_ON_ONCE(ctx
->parent_ctx
);
8575 * See perf_event_ctx_lock() for comments on the details
8576 * of swizzling perf_event::ctx.
8578 perf_remove_from_context(group_leader
, 0);
8580 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8582 perf_remove_from_context(sibling
, 0);
8587 * Wait for everybody to stop referencing the events through
8588 * the old lists, before installing it on new lists.
8593 * Install the group siblings before the group leader.
8595 * Because a group leader will try and install the entire group
8596 * (through the sibling list, which is still in-tact), we can
8597 * end up with siblings installed in the wrong context.
8599 * By installing siblings first we NO-OP because they're not
8600 * reachable through the group lists.
8602 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8604 perf_event__state_init(sibling
);
8605 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8610 * Removing from the context ends up with disabled
8611 * event. What we want here is event in the initial
8612 * startup state, ready to be add into new context.
8614 perf_event__state_init(group_leader
);
8615 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8619 * Now that all events are installed in @ctx, nothing
8620 * references @gctx anymore, so drop the last reference we have
8627 * Precalculate sample_data sizes; do while holding ctx::mutex such
8628 * that we're serialized against further additions and before
8629 * perf_install_in_context() which is the point the event is active and
8630 * can use these values.
8632 perf_event__header_size(event
);
8633 perf_event__id_header_size(event
);
8635 event
->owner
= current
;
8637 perf_install_in_context(ctx
, event
, event
->cpu
);
8638 perf_unpin_context(ctx
);
8641 mutex_unlock(&gctx
->mutex
);
8642 mutex_unlock(&ctx
->mutex
);
8646 mutex_lock(¤t
->perf_event_mutex
);
8647 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8648 mutex_unlock(¤t
->perf_event_mutex
);
8651 * Drop the reference on the group_event after placing the
8652 * new event on the sibling_list. This ensures destruction
8653 * of the group leader will find the pointer to itself in
8654 * perf_group_detach().
8657 fd_install(event_fd
, event_file
);
8662 mutex_unlock(&gctx
->mutex
);
8663 mutex_unlock(&ctx
->mutex
);
8667 perf_unpin_context(ctx
);
8671 * If event_file is set, the fput() above will have called ->release()
8672 * and that will take care of freeing the event.
8680 put_task_struct(task
);
8684 put_unused_fd(event_fd
);
8689 * perf_event_create_kernel_counter
8691 * @attr: attributes of the counter to create
8692 * @cpu: cpu in which the counter is bound
8693 * @task: task to profile (NULL for percpu)
8696 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8697 struct task_struct
*task
,
8698 perf_overflow_handler_t overflow_handler
,
8701 struct perf_event_context
*ctx
;
8702 struct perf_event
*event
;
8706 * Get the target context (task or percpu):
8709 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8710 overflow_handler
, context
, -1);
8711 if (IS_ERR(event
)) {
8712 err
= PTR_ERR(event
);
8716 /* Mark owner so we could distinguish it from user events. */
8717 event
->owner
= TASK_TOMBSTONE
;
8719 ctx
= find_get_context(event
->pmu
, task
, event
);
8725 WARN_ON_ONCE(ctx
->parent_ctx
);
8726 mutex_lock(&ctx
->mutex
);
8727 if (ctx
->task
== TASK_TOMBSTONE
) {
8732 if (!exclusive_event_installable(event
, ctx
)) {
8737 perf_install_in_context(ctx
, event
, cpu
);
8738 perf_unpin_context(ctx
);
8739 mutex_unlock(&ctx
->mutex
);
8744 mutex_unlock(&ctx
->mutex
);
8745 perf_unpin_context(ctx
);
8750 return ERR_PTR(err
);
8752 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8754 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8756 struct perf_event_context
*src_ctx
;
8757 struct perf_event_context
*dst_ctx
;
8758 struct perf_event
*event
, *tmp
;
8761 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8762 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8765 * See perf_event_ctx_lock() for comments on the details
8766 * of swizzling perf_event::ctx.
8768 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8769 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8771 perf_remove_from_context(event
, 0);
8772 unaccount_event_cpu(event
, src_cpu
);
8774 list_add(&event
->migrate_entry
, &events
);
8778 * Wait for the events to quiesce before re-instating them.
8783 * Re-instate events in 2 passes.
8785 * Skip over group leaders and only install siblings on this first
8786 * pass, siblings will not get enabled without a leader, however a
8787 * leader will enable its siblings, even if those are still on the old
8790 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8791 if (event
->group_leader
== event
)
8794 list_del(&event
->migrate_entry
);
8795 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8796 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8797 account_event_cpu(event
, dst_cpu
);
8798 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8803 * Once all the siblings are setup properly, install the group leaders
8806 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8807 list_del(&event
->migrate_entry
);
8808 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8809 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8810 account_event_cpu(event
, dst_cpu
);
8811 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8814 mutex_unlock(&dst_ctx
->mutex
);
8815 mutex_unlock(&src_ctx
->mutex
);
8817 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8819 static void sync_child_event(struct perf_event
*child_event
,
8820 struct task_struct
*child
)
8822 struct perf_event
*parent_event
= child_event
->parent
;
8825 if (child_event
->attr
.inherit_stat
)
8826 perf_event_read_event(child_event
, child
);
8828 child_val
= perf_event_count(child_event
);
8831 * Add back the child's count to the parent's count:
8833 atomic64_add(child_val
, &parent_event
->child_count
);
8834 atomic64_add(child_event
->total_time_enabled
,
8835 &parent_event
->child_total_time_enabled
);
8836 atomic64_add(child_event
->total_time_running
,
8837 &parent_event
->child_total_time_running
);
8841 perf_event_exit_event(struct perf_event
*child_event
,
8842 struct perf_event_context
*child_ctx
,
8843 struct task_struct
*child
)
8845 struct perf_event
*parent_event
= child_event
->parent
;
8848 * Do not destroy the 'original' grouping; because of the context
8849 * switch optimization the original events could've ended up in a
8850 * random child task.
8852 * If we were to destroy the original group, all group related
8853 * operations would cease to function properly after this random
8856 * Do destroy all inherited groups, we don't care about those
8857 * and being thorough is better.
8859 raw_spin_lock_irq(&child_ctx
->lock
);
8860 WARN_ON_ONCE(child_ctx
->is_active
);
8863 perf_group_detach(child_event
);
8864 list_del_event(child_event
, child_ctx
);
8865 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
8866 raw_spin_unlock_irq(&child_ctx
->lock
);
8869 * Parent events are governed by their filedesc, retain them.
8871 if (!parent_event
) {
8872 perf_event_wakeup(child_event
);
8876 * Child events can be cleaned up.
8879 sync_child_event(child_event
, child
);
8882 * Remove this event from the parent's list
8884 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8885 mutex_lock(&parent_event
->child_mutex
);
8886 list_del_init(&child_event
->child_list
);
8887 mutex_unlock(&parent_event
->child_mutex
);
8890 * Kick perf_poll() for is_event_hup().
8892 perf_event_wakeup(parent_event
);
8893 free_event(child_event
);
8894 put_event(parent_event
);
8897 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8899 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8900 struct perf_event
*child_event
, *next
;
8902 WARN_ON_ONCE(child
!= current
);
8904 child_ctx
= perf_pin_task_context(child
, ctxn
);
8909 * In order to reduce the amount of tricky in ctx tear-down, we hold
8910 * ctx::mutex over the entire thing. This serializes against almost
8911 * everything that wants to access the ctx.
8913 * The exception is sys_perf_event_open() /
8914 * perf_event_create_kernel_count() which does find_get_context()
8915 * without ctx::mutex (it cannot because of the move_group double mutex
8916 * lock thing). See the comments in perf_install_in_context().
8918 mutex_lock(&child_ctx
->mutex
);
8921 * In a single ctx::lock section, de-schedule the events and detach the
8922 * context from the task such that we cannot ever get it scheduled back
8925 raw_spin_lock_irq(&child_ctx
->lock
);
8926 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
);
8929 * Now that the context is inactive, destroy the task <-> ctx relation
8930 * and mark the context dead.
8932 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
8933 put_ctx(child_ctx
); /* cannot be last */
8934 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
8935 put_task_struct(current
); /* cannot be last */
8937 clone_ctx
= unclone_ctx(child_ctx
);
8938 raw_spin_unlock_irq(&child_ctx
->lock
);
8944 * Report the task dead after unscheduling the events so that we
8945 * won't get any samples after PERF_RECORD_EXIT. We can however still
8946 * get a few PERF_RECORD_READ events.
8948 perf_event_task(child
, child_ctx
, 0);
8950 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8951 perf_event_exit_event(child_event
, child_ctx
, child
);
8953 mutex_unlock(&child_ctx
->mutex
);
8959 * When a child task exits, feed back event values to parent events.
8961 void perf_event_exit_task(struct task_struct
*child
)
8963 struct perf_event
*event
, *tmp
;
8966 mutex_lock(&child
->perf_event_mutex
);
8967 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8969 list_del_init(&event
->owner_entry
);
8972 * Ensure the list deletion is visible before we clear
8973 * the owner, closes a race against perf_release() where
8974 * we need to serialize on the owner->perf_event_mutex.
8976 smp_store_release(&event
->owner
, NULL
);
8978 mutex_unlock(&child
->perf_event_mutex
);
8980 for_each_task_context_nr(ctxn
)
8981 perf_event_exit_task_context(child
, ctxn
);
8984 * The perf_event_exit_task_context calls perf_event_task
8985 * with child's task_ctx, which generates EXIT events for
8986 * child contexts and sets child->perf_event_ctxp[] to NULL.
8987 * At this point we need to send EXIT events to cpu contexts.
8989 perf_event_task(child
, NULL
, 0);
8992 static void perf_free_event(struct perf_event
*event
,
8993 struct perf_event_context
*ctx
)
8995 struct perf_event
*parent
= event
->parent
;
8997 if (WARN_ON_ONCE(!parent
))
9000 mutex_lock(&parent
->child_mutex
);
9001 list_del_init(&event
->child_list
);
9002 mutex_unlock(&parent
->child_mutex
);
9006 raw_spin_lock_irq(&ctx
->lock
);
9007 perf_group_detach(event
);
9008 list_del_event(event
, ctx
);
9009 raw_spin_unlock_irq(&ctx
->lock
);
9014 * Free an unexposed, unused context as created by inheritance by
9015 * perf_event_init_task below, used by fork() in case of fail.
9017 * Not all locks are strictly required, but take them anyway to be nice and
9018 * help out with the lockdep assertions.
9020 void perf_event_free_task(struct task_struct
*task
)
9022 struct perf_event_context
*ctx
;
9023 struct perf_event
*event
, *tmp
;
9026 for_each_task_context_nr(ctxn
) {
9027 ctx
= task
->perf_event_ctxp
[ctxn
];
9031 mutex_lock(&ctx
->mutex
);
9033 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
9035 perf_free_event(event
, ctx
);
9037 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
9039 perf_free_event(event
, ctx
);
9041 if (!list_empty(&ctx
->pinned_groups
) ||
9042 !list_empty(&ctx
->flexible_groups
))
9045 mutex_unlock(&ctx
->mutex
);
9051 void perf_event_delayed_put(struct task_struct
*task
)
9055 for_each_task_context_nr(ctxn
)
9056 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
9059 struct file
*perf_event_get(unsigned int fd
)
9063 file
= fget_raw(fd
);
9065 return ERR_PTR(-EBADF
);
9067 if (file
->f_op
!= &perf_fops
) {
9069 return ERR_PTR(-EBADF
);
9075 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
9078 return ERR_PTR(-EINVAL
);
9080 return &event
->attr
;
9084 * inherit a event from parent task to child task:
9086 static struct perf_event
*
9087 inherit_event(struct perf_event
*parent_event
,
9088 struct task_struct
*parent
,
9089 struct perf_event_context
*parent_ctx
,
9090 struct task_struct
*child
,
9091 struct perf_event
*group_leader
,
9092 struct perf_event_context
*child_ctx
)
9094 enum perf_event_active_state parent_state
= parent_event
->state
;
9095 struct perf_event
*child_event
;
9096 unsigned long flags
;
9099 * Instead of creating recursive hierarchies of events,
9100 * we link inherited events back to the original parent,
9101 * which has a filp for sure, which we use as the reference
9104 if (parent_event
->parent
)
9105 parent_event
= parent_event
->parent
;
9107 child_event
= perf_event_alloc(&parent_event
->attr
,
9110 group_leader
, parent_event
,
9112 if (IS_ERR(child_event
))
9116 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
9117 * must be under the same lock in order to serialize against
9118 * perf_event_release_kernel(), such that either we must observe
9119 * is_orphaned_event() or they will observe us on the child_list.
9121 mutex_lock(&parent_event
->child_mutex
);
9122 if (is_orphaned_event(parent_event
) ||
9123 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
9124 mutex_unlock(&parent_event
->child_mutex
);
9125 free_event(child_event
);
9132 * Make the child state follow the state of the parent event,
9133 * not its attr.disabled bit. We hold the parent's mutex,
9134 * so we won't race with perf_event_{en, dis}able_family.
9136 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
9137 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
9139 child_event
->state
= PERF_EVENT_STATE_OFF
;
9141 if (parent_event
->attr
.freq
) {
9142 u64 sample_period
= parent_event
->hw
.sample_period
;
9143 struct hw_perf_event
*hwc
= &child_event
->hw
;
9145 hwc
->sample_period
= sample_period
;
9146 hwc
->last_period
= sample_period
;
9148 local64_set(&hwc
->period_left
, sample_period
);
9151 child_event
->ctx
= child_ctx
;
9152 child_event
->overflow_handler
= parent_event
->overflow_handler
;
9153 child_event
->overflow_handler_context
9154 = parent_event
->overflow_handler_context
;
9157 * Precalculate sample_data sizes
9159 perf_event__header_size(child_event
);
9160 perf_event__id_header_size(child_event
);
9163 * Link it up in the child's context:
9165 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
9166 add_event_to_ctx(child_event
, child_ctx
);
9167 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
9170 * Link this into the parent event's child list
9172 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
9173 mutex_unlock(&parent_event
->child_mutex
);
9178 static int inherit_group(struct perf_event
*parent_event
,
9179 struct task_struct
*parent
,
9180 struct perf_event_context
*parent_ctx
,
9181 struct task_struct
*child
,
9182 struct perf_event_context
*child_ctx
)
9184 struct perf_event
*leader
;
9185 struct perf_event
*sub
;
9186 struct perf_event
*child_ctr
;
9188 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9189 child
, NULL
, child_ctx
);
9191 return PTR_ERR(leader
);
9192 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9193 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9194 child
, leader
, child_ctx
);
9195 if (IS_ERR(child_ctr
))
9196 return PTR_ERR(child_ctr
);
9202 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9203 struct perf_event_context
*parent_ctx
,
9204 struct task_struct
*child
, int ctxn
,
9208 struct perf_event_context
*child_ctx
;
9210 if (!event
->attr
.inherit
) {
9215 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9218 * This is executed from the parent task context, so
9219 * inherit events that have been marked for cloning.
9220 * First allocate and initialize a context for the
9224 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9228 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9231 ret
= inherit_group(event
, parent
, parent_ctx
,
9241 * Initialize the perf_event context in task_struct
9243 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9245 struct perf_event_context
*child_ctx
, *parent_ctx
;
9246 struct perf_event_context
*cloned_ctx
;
9247 struct perf_event
*event
;
9248 struct task_struct
*parent
= current
;
9249 int inherited_all
= 1;
9250 unsigned long flags
;
9253 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9257 * If the parent's context is a clone, pin it so it won't get
9260 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9265 * No need to check if parent_ctx != NULL here; since we saw
9266 * it non-NULL earlier, the only reason for it to become NULL
9267 * is if we exit, and since we're currently in the middle of
9268 * a fork we can't be exiting at the same time.
9272 * Lock the parent list. No need to lock the child - not PID
9273 * hashed yet and not running, so nobody can access it.
9275 mutex_lock(&parent_ctx
->mutex
);
9278 * We dont have to disable NMIs - we are only looking at
9279 * the list, not manipulating it:
9281 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9282 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9283 child
, ctxn
, &inherited_all
);
9289 * We can't hold ctx->lock when iterating the ->flexible_group list due
9290 * to allocations, but we need to prevent rotation because
9291 * rotate_ctx() will change the list from interrupt context.
9293 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9294 parent_ctx
->rotate_disable
= 1;
9295 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9297 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9298 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9299 child
, ctxn
, &inherited_all
);
9304 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9305 parent_ctx
->rotate_disable
= 0;
9307 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9309 if (child_ctx
&& inherited_all
) {
9311 * Mark the child context as a clone of the parent
9312 * context, or of whatever the parent is a clone of.
9314 * Note that if the parent is a clone, the holding of
9315 * parent_ctx->lock avoids it from being uncloned.
9317 cloned_ctx
= parent_ctx
->parent_ctx
;
9319 child_ctx
->parent_ctx
= cloned_ctx
;
9320 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9322 child_ctx
->parent_ctx
= parent_ctx
;
9323 child_ctx
->parent_gen
= parent_ctx
->generation
;
9325 get_ctx(child_ctx
->parent_ctx
);
9328 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9329 mutex_unlock(&parent_ctx
->mutex
);
9331 perf_unpin_context(parent_ctx
);
9332 put_ctx(parent_ctx
);
9338 * Initialize the perf_event context in task_struct
9340 int perf_event_init_task(struct task_struct
*child
)
9344 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9345 mutex_init(&child
->perf_event_mutex
);
9346 INIT_LIST_HEAD(&child
->perf_event_list
);
9348 for_each_task_context_nr(ctxn
) {
9349 ret
= perf_event_init_context(child
, ctxn
);
9351 perf_event_free_task(child
);
9359 static void __init
perf_event_init_all_cpus(void)
9361 struct swevent_htable
*swhash
;
9364 for_each_possible_cpu(cpu
) {
9365 swhash
= &per_cpu(swevent_htable
, cpu
);
9366 mutex_init(&swhash
->hlist_mutex
);
9367 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9371 static void perf_event_init_cpu(int cpu
)
9373 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9375 mutex_lock(&swhash
->hlist_mutex
);
9376 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
9377 struct swevent_hlist
*hlist
;
9379 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9381 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9383 mutex_unlock(&swhash
->hlist_mutex
);
9386 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9387 static void __perf_event_exit_context(void *__info
)
9389 struct perf_event_context
*ctx
= __info
;
9390 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
9391 struct perf_event
*event
;
9393 raw_spin_lock(&ctx
->lock
);
9394 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
9395 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
9396 raw_spin_unlock(&ctx
->lock
);
9399 static void perf_event_exit_cpu_context(int cpu
)
9401 struct perf_event_context
*ctx
;
9405 idx
= srcu_read_lock(&pmus_srcu
);
9406 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9407 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9409 mutex_lock(&ctx
->mutex
);
9410 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9411 mutex_unlock(&ctx
->mutex
);
9413 srcu_read_unlock(&pmus_srcu
, idx
);
9416 static void perf_event_exit_cpu(int cpu
)
9418 perf_event_exit_cpu_context(cpu
);
9421 static inline void perf_event_exit_cpu(int cpu
) { }
9425 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9429 for_each_online_cpu(cpu
)
9430 perf_event_exit_cpu(cpu
);
9436 * Run the perf reboot notifier at the very last possible moment so that
9437 * the generic watchdog code runs as long as possible.
9439 static struct notifier_block perf_reboot_notifier
= {
9440 .notifier_call
= perf_reboot
,
9441 .priority
= INT_MIN
,
9445 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9447 unsigned int cpu
= (long)hcpu
;
9449 switch (action
& ~CPU_TASKS_FROZEN
) {
9451 case CPU_UP_PREPARE
:
9453 * This must be done before the CPU comes alive, because the
9454 * moment we can run tasks we can encounter (software) events.
9456 * Specifically, someone can have inherited events on kthreadd
9457 * or a pre-existing worker thread that gets re-bound.
9459 perf_event_init_cpu(cpu
);
9462 case CPU_DOWN_PREPARE
:
9464 * This must be done before the CPU dies because after that an
9465 * active event might want to IPI the CPU and that'll not work
9466 * so great for dead CPUs.
9468 * XXX smp_call_function_single() return -ENXIO without a warn
9469 * so we could possibly deal with this.
9471 * This is safe against new events arriving because
9472 * sys_perf_event_open() serializes against hotplug using
9473 * get_online_cpus().
9475 perf_event_exit_cpu(cpu
);
9484 void __init
perf_event_init(void)
9490 perf_event_init_all_cpus();
9491 init_srcu_struct(&pmus_srcu
);
9492 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9493 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9494 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9496 perf_cpu_notifier(perf_cpu_notify
);
9497 register_reboot_notifier(&perf_reboot_notifier
);
9499 ret
= init_hw_breakpoint();
9500 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9503 * Build time assertion that we keep the data_head at the intended
9504 * location. IOW, validation we got the __reserved[] size right.
9506 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9510 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9513 struct perf_pmu_events_attr
*pmu_attr
=
9514 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9516 if (pmu_attr
->event_str
)
9517 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9521 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
9523 static int __init
perf_event_sysfs_init(void)
9528 mutex_lock(&pmus_lock
);
9530 ret
= bus_register(&pmu_bus
);
9534 list_for_each_entry(pmu
, &pmus
, entry
) {
9535 if (!pmu
->name
|| pmu
->type
< 0)
9538 ret
= pmu_dev_alloc(pmu
);
9539 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9541 pmu_bus_running
= 1;
9545 mutex_unlock(&pmus_lock
);
9549 device_initcall(perf_event_sysfs_init
);
9551 #ifdef CONFIG_CGROUP_PERF
9552 static struct cgroup_subsys_state
*
9553 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9555 struct perf_cgroup
*jc
;
9557 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9559 return ERR_PTR(-ENOMEM
);
9561 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9564 return ERR_PTR(-ENOMEM
);
9570 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9572 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9574 free_percpu(jc
->info
);
9578 static int __perf_cgroup_move(void *info
)
9580 struct task_struct
*task
= info
;
9582 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9587 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
9589 struct task_struct
*task
;
9590 struct cgroup_subsys_state
*css
;
9592 cgroup_taskset_for_each(task
, css
, tset
)
9593 task_function_call(task
, __perf_cgroup_move
, task
);
9596 struct cgroup_subsys perf_event_cgrp_subsys
= {
9597 .css_alloc
= perf_cgroup_css_alloc
,
9598 .css_free
= perf_cgroup_css_free
,
9599 .attach
= perf_cgroup_attach
,
9601 #endif /* CONFIG_CGROUP_PERF */