2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
50 #include <asm/irq_regs.h>
52 static struct workqueue_struct
*perf_wq
;
54 typedef int (*remote_function_f
)(void *);
56 struct remote_function_call
{
57 struct task_struct
*p
;
58 remote_function_f func
;
63 static void remote_function(void *data
)
65 struct remote_function_call
*tfc
= data
;
66 struct task_struct
*p
= tfc
->p
;
70 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
74 tfc
->ret
= tfc
->func(tfc
->info
);
78 * task_function_call - call a function on the cpu on which a task runs
79 * @p: the task to evaluate
80 * @func: the function to be called
81 * @info: the function call argument
83 * Calls the function @func when the task is currently running. This might
84 * be on the current CPU, which just calls the function directly
86 * returns: @func return value, or
87 * -ESRCH - when the process isn't running
88 * -EAGAIN - when the process moved away
91 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
93 struct remote_function_call data
= {
97 .ret
= -ESRCH
, /* No such (running) process */
101 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
107 * cpu_function_call - call a function on the cpu
108 * @func: the function to be called
109 * @info: the function call argument
111 * Calls the function @func on the remote cpu.
113 * returns: @func return value or -ENXIO when the cpu is offline
115 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
117 struct remote_function_call data
= {
121 .ret
= -ENXIO
, /* No such CPU */
124 smp_call_function_single(cpu
, remote_function
, &data
, 1);
130 * On task ctx scheduling...
132 * When !ctx->nr_events a task context will not be scheduled. This means
133 * we can disable the scheduler hooks (for performance) without leaving
134 * pending task ctx state.
136 * This however results in two special cases:
138 * - removing the last event from a task ctx; this is relatively straight
139 * forward and is done in __perf_remove_from_context.
141 * - adding the first event to a task ctx; this is tricky because we cannot
142 * rely on ctx->is_active and therefore cannot use event_function_call().
143 * See perf_install_in_context().
145 * This is because we need a ctx->lock serialized variable (ctx->is_active)
146 * to reliably determine if a particular task/context is scheduled in. The
147 * task_curr() use in task_function_call() is racy in that a remote context
148 * switch is not a single atomic operation.
150 * As is, the situation is 'safe' because we set rq->curr before we do the
151 * actual context switch. This means that task_curr() will fail early, but
152 * we'll continue spinning on ctx->is_active until we've passed
153 * perf_event_task_sched_out().
155 * Without this ctx->lock serialized variable we could have race where we find
156 * the task (and hence the context) would not be active while in fact they are.
158 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
161 static void event_function_call(struct perf_event
*event
,
162 int (*active
)(void *),
163 void (*inactive
)(void *),
166 struct perf_event_context
*ctx
= event
->ctx
;
167 struct task_struct
*task
= ctx
->task
;
170 cpu_function_call(event
->cpu
, active
, data
);
175 if (!task_function_call(task
, active
, data
))
178 raw_spin_lock_irq(&ctx
->lock
);
179 if (ctx
->is_active
) {
181 * Reload the task pointer, it might have been changed by
182 * a concurrent perf_event_context_sched_out().
185 raw_spin_unlock_irq(&ctx
->lock
);
189 raw_spin_unlock_irq(&ctx
->lock
);
192 #define EVENT_OWNER_KERNEL ((void *) -1)
194 static bool is_kernel_event(struct perf_event
*event
)
196 return event
->owner
== EVENT_OWNER_KERNEL
;
199 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
200 PERF_FLAG_FD_OUTPUT |\
201 PERF_FLAG_PID_CGROUP |\
202 PERF_FLAG_FD_CLOEXEC)
205 * branch priv levels that need permission checks
207 #define PERF_SAMPLE_BRANCH_PERM_PLM \
208 (PERF_SAMPLE_BRANCH_KERNEL |\
209 PERF_SAMPLE_BRANCH_HV)
212 EVENT_FLEXIBLE
= 0x1,
214 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
218 * perf_sched_events : >0 events exist
219 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
221 struct static_key_deferred perf_sched_events __read_mostly
;
222 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
223 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
225 static atomic_t nr_mmap_events __read_mostly
;
226 static atomic_t nr_comm_events __read_mostly
;
227 static atomic_t nr_task_events __read_mostly
;
228 static atomic_t nr_freq_events __read_mostly
;
229 static atomic_t nr_switch_events __read_mostly
;
231 static LIST_HEAD(pmus
);
232 static DEFINE_MUTEX(pmus_lock
);
233 static struct srcu_struct pmus_srcu
;
236 * perf event paranoia level:
237 * -1 - not paranoid at all
238 * 0 - disallow raw tracepoint access for unpriv
239 * 1 - disallow cpu events for unpriv
240 * 2 - disallow kernel profiling for unpriv
242 int sysctl_perf_event_paranoid __read_mostly
= 1;
244 /* Minimum for 512 kiB + 1 user control page */
245 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
248 * max perf event sample rate
250 #define DEFAULT_MAX_SAMPLE_RATE 100000
251 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
252 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
254 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
256 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
257 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
259 static int perf_sample_allowed_ns __read_mostly
=
260 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
262 static void update_perf_cpu_limits(void)
264 u64 tmp
= perf_sample_period_ns
;
266 tmp
*= sysctl_perf_cpu_time_max_percent
;
268 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
271 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
273 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
274 void __user
*buffer
, size_t *lenp
,
277 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
282 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
283 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
284 update_perf_cpu_limits();
289 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
291 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
292 void __user
*buffer
, size_t *lenp
,
295 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
300 update_perf_cpu_limits();
306 * perf samples are done in some very critical code paths (NMIs).
307 * If they take too much CPU time, the system can lock up and not
308 * get any real work done. This will drop the sample rate when
309 * we detect that events are taking too long.
311 #define NR_ACCUMULATED_SAMPLES 128
312 static DEFINE_PER_CPU(u64
, running_sample_length
);
314 static void perf_duration_warn(struct irq_work
*w
)
316 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
317 u64 avg_local_sample_len
;
318 u64 local_samples_len
;
320 local_samples_len
= __this_cpu_read(running_sample_length
);
321 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
323 printk_ratelimited(KERN_WARNING
324 "perf interrupt took too long (%lld > %lld), lowering "
325 "kernel.perf_event_max_sample_rate to %d\n",
326 avg_local_sample_len
, allowed_ns
>> 1,
327 sysctl_perf_event_sample_rate
);
330 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
332 void perf_sample_event_took(u64 sample_len_ns
)
334 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
335 u64 avg_local_sample_len
;
336 u64 local_samples_len
;
341 /* decay the counter by 1 average sample */
342 local_samples_len
= __this_cpu_read(running_sample_length
);
343 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
344 local_samples_len
+= sample_len_ns
;
345 __this_cpu_write(running_sample_length
, local_samples_len
);
348 * note: this will be biased artifically low until we have
349 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
350 * from having to maintain a count.
352 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
354 if (avg_local_sample_len
<= allowed_ns
)
357 if (max_samples_per_tick
<= 1)
360 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
361 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
362 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
364 update_perf_cpu_limits();
366 if (!irq_work_queue(&perf_duration_work
)) {
367 early_printk("perf interrupt took too long (%lld > %lld), lowering "
368 "kernel.perf_event_max_sample_rate to %d\n",
369 avg_local_sample_len
, allowed_ns
>> 1,
370 sysctl_perf_event_sample_rate
);
374 static atomic64_t perf_event_id
;
376 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
377 enum event_type_t event_type
);
379 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
380 enum event_type_t event_type
,
381 struct task_struct
*task
);
383 static void update_context_time(struct perf_event_context
*ctx
);
384 static u64
perf_event_time(struct perf_event
*event
);
386 void __weak
perf_event_print_debug(void) { }
388 extern __weak
const char *perf_pmu_name(void)
393 static inline u64
perf_clock(void)
395 return local_clock();
398 static inline u64
perf_event_clock(struct perf_event
*event
)
400 return event
->clock();
403 static inline struct perf_cpu_context
*
404 __get_cpu_context(struct perf_event_context
*ctx
)
406 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
409 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
410 struct perf_event_context
*ctx
)
412 raw_spin_lock(&cpuctx
->ctx
.lock
);
414 raw_spin_lock(&ctx
->lock
);
417 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
418 struct perf_event_context
*ctx
)
421 raw_spin_unlock(&ctx
->lock
);
422 raw_spin_unlock(&cpuctx
->ctx
.lock
);
425 #ifdef CONFIG_CGROUP_PERF
428 perf_cgroup_match(struct perf_event
*event
)
430 struct perf_event_context
*ctx
= event
->ctx
;
431 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
433 /* @event doesn't care about cgroup */
437 /* wants specific cgroup scope but @cpuctx isn't associated with any */
442 * Cgroup scoping is recursive. An event enabled for a cgroup is
443 * also enabled for all its descendant cgroups. If @cpuctx's
444 * cgroup is a descendant of @event's (the test covers identity
445 * case), it's a match.
447 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
448 event
->cgrp
->css
.cgroup
);
451 static inline void perf_detach_cgroup(struct perf_event
*event
)
453 css_put(&event
->cgrp
->css
);
457 static inline int is_cgroup_event(struct perf_event
*event
)
459 return event
->cgrp
!= NULL
;
462 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
464 struct perf_cgroup_info
*t
;
466 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
470 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
472 struct perf_cgroup_info
*info
;
477 info
= this_cpu_ptr(cgrp
->info
);
479 info
->time
+= now
- info
->timestamp
;
480 info
->timestamp
= now
;
483 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
485 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
487 __update_cgrp_time(cgrp_out
);
490 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
492 struct perf_cgroup
*cgrp
;
495 * ensure we access cgroup data only when needed and
496 * when we know the cgroup is pinned (css_get)
498 if (!is_cgroup_event(event
))
501 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
503 * Do not update time when cgroup is not active
505 if (cgrp
== event
->cgrp
)
506 __update_cgrp_time(event
->cgrp
);
510 perf_cgroup_set_timestamp(struct task_struct
*task
,
511 struct perf_event_context
*ctx
)
513 struct perf_cgroup
*cgrp
;
514 struct perf_cgroup_info
*info
;
517 * ctx->lock held by caller
518 * ensure we do not access cgroup data
519 * unless we have the cgroup pinned (css_get)
521 if (!task
|| !ctx
->nr_cgroups
)
524 cgrp
= perf_cgroup_from_task(task
, ctx
);
525 info
= this_cpu_ptr(cgrp
->info
);
526 info
->timestamp
= ctx
->timestamp
;
529 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
530 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
533 * reschedule events based on the cgroup constraint of task.
535 * mode SWOUT : schedule out everything
536 * mode SWIN : schedule in based on cgroup for next
538 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
540 struct perf_cpu_context
*cpuctx
;
545 * disable interrupts to avoid geting nr_cgroup
546 * changes via __perf_event_disable(). Also
549 local_irq_save(flags
);
552 * we reschedule only in the presence of cgroup
553 * constrained events.
556 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
557 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
558 if (cpuctx
->unique_pmu
!= pmu
)
559 continue; /* ensure we process each cpuctx once */
562 * perf_cgroup_events says at least one
563 * context on this CPU has cgroup events.
565 * ctx->nr_cgroups reports the number of cgroup
566 * events for a context.
568 if (cpuctx
->ctx
.nr_cgroups
> 0) {
569 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
570 perf_pmu_disable(cpuctx
->ctx
.pmu
);
572 if (mode
& PERF_CGROUP_SWOUT
) {
573 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
575 * must not be done before ctxswout due
576 * to event_filter_match() in event_sched_out()
581 if (mode
& PERF_CGROUP_SWIN
) {
582 WARN_ON_ONCE(cpuctx
->cgrp
);
584 * set cgrp before ctxsw in to allow
585 * event_filter_match() to not have to pass
587 * we pass the cpuctx->ctx to perf_cgroup_from_task()
588 * because cgorup events are only per-cpu
590 cpuctx
->cgrp
= perf_cgroup_from_task(task
, &cpuctx
->ctx
);
591 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
593 perf_pmu_enable(cpuctx
->ctx
.pmu
);
594 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
598 local_irq_restore(flags
);
601 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
602 struct task_struct
*next
)
604 struct perf_cgroup
*cgrp1
;
605 struct perf_cgroup
*cgrp2
= NULL
;
609 * we come here when we know perf_cgroup_events > 0
610 * we do not need to pass the ctx here because we know
611 * we are holding the rcu lock
613 cgrp1
= perf_cgroup_from_task(task
, NULL
);
614 cgrp2
= perf_cgroup_from_task(next
, NULL
);
617 * only schedule out current cgroup events if we know
618 * that we are switching to a different cgroup. Otherwise,
619 * do no touch the cgroup events.
622 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
627 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
628 struct task_struct
*task
)
630 struct perf_cgroup
*cgrp1
;
631 struct perf_cgroup
*cgrp2
= NULL
;
635 * we come here when we know perf_cgroup_events > 0
636 * we do not need to pass the ctx here because we know
637 * we are holding the rcu lock
639 cgrp1
= perf_cgroup_from_task(task
, NULL
);
640 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
643 * only need to schedule in cgroup events if we are changing
644 * cgroup during ctxsw. Cgroup events were not scheduled
645 * out of ctxsw out if that was not the case.
648 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
653 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
654 struct perf_event_attr
*attr
,
655 struct perf_event
*group_leader
)
657 struct perf_cgroup
*cgrp
;
658 struct cgroup_subsys_state
*css
;
659 struct fd f
= fdget(fd
);
665 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
666 &perf_event_cgrp_subsys
);
672 cgrp
= container_of(css
, struct perf_cgroup
, css
);
676 * all events in a group must monitor
677 * the same cgroup because a task belongs
678 * to only one perf cgroup at a time
680 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
681 perf_detach_cgroup(event
);
690 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
692 struct perf_cgroup_info
*t
;
693 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
694 event
->shadow_ctx_time
= now
- t
->timestamp
;
698 perf_cgroup_defer_enabled(struct perf_event
*event
)
701 * when the current task's perf cgroup does not match
702 * the event's, we need to remember to call the
703 * perf_mark_enable() function the first time a task with
704 * a matching perf cgroup is scheduled in.
706 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
707 event
->cgrp_defer_enabled
= 1;
711 perf_cgroup_mark_enabled(struct perf_event
*event
,
712 struct perf_event_context
*ctx
)
714 struct perf_event
*sub
;
715 u64 tstamp
= perf_event_time(event
);
717 if (!event
->cgrp_defer_enabled
)
720 event
->cgrp_defer_enabled
= 0;
722 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
723 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
724 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
725 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
726 sub
->cgrp_defer_enabled
= 0;
730 #else /* !CONFIG_CGROUP_PERF */
733 perf_cgroup_match(struct perf_event
*event
)
738 static inline void perf_detach_cgroup(struct perf_event
*event
)
741 static inline int is_cgroup_event(struct perf_event
*event
)
746 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
751 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
755 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
759 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
760 struct task_struct
*next
)
764 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
765 struct task_struct
*task
)
769 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
770 struct perf_event_attr
*attr
,
771 struct perf_event
*group_leader
)
777 perf_cgroup_set_timestamp(struct task_struct
*task
,
778 struct perf_event_context
*ctx
)
783 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
788 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
792 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
798 perf_cgroup_defer_enabled(struct perf_event
*event
)
803 perf_cgroup_mark_enabled(struct perf_event
*event
,
804 struct perf_event_context
*ctx
)
810 * set default to be dependent on timer tick just
813 #define PERF_CPU_HRTIMER (1000 / HZ)
815 * function must be called with interrupts disbled
817 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
819 struct perf_cpu_context
*cpuctx
;
822 WARN_ON(!irqs_disabled());
824 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
825 rotations
= perf_rotate_context(cpuctx
);
827 raw_spin_lock(&cpuctx
->hrtimer_lock
);
829 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
831 cpuctx
->hrtimer_active
= 0;
832 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
834 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
837 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
839 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
840 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
843 /* no multiplexing needed for SW PMU */
844 if (pmu
->task_ctx_nr
== perf_sw_context
)
848 * check default is sane, if not set then force to
849 * default interval (1/tick)
851 interval
= pmu
->hrtimer_interval_ms
;
853 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
855 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
857 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
858 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
859 timer
->function
= perf_mux_hrtimer_handler
;
862 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
864 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
865 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
869 if (pmu
->task_ctx_nr
== perf_sw_context
)
872 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
873 if (!cpuctx
->hrtimer_active
) {
874 cpuctx
->hrtimer_active
= 1;
875 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
876 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
878 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
883 void perf_pmu_disable(struct pmu
*pmu
)
885 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
887 pmu
->pmu_disable(pmu
);
890 void perf_pmu_enable(struct pmu
*pmu
)
892 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
894 pmu
->pmu_enable(pmu
);
897 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
900 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
901 * perf_event_task_tick() are fully serialized because they're strictly cpu
902 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
903 * disabled, while perf_event_task_tick is called from IRQ context.
905 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
907 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
909 WARN_ON(!irqs_disabled());
911 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
913 list_add(&ctx
->active_ctx_list
, head
);
916 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
918 WARN_ON(!irqs_disabled());
920 WARN_ON(list_empty(&ctx
->active_ctx_list
));
922 list_del_init(&ctx
->active_ctx_list
);
925 static void get_ctx(struct perf_event_context
*ctx
)
927 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
930 static void free_ctx(struct rcu_head
*head
)
932 struct perf_event_context
*ctx
;
934 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
935 kfree(ctx
->task_ctx_data
);
939 static void put_ctx(struct perf_event_context
*ctx
)
941 if (atomic_dec_and_test(&ctx
->refcount
)) {
943 put_ctx(ctx
->parent_ctx
);
945 put_task_struct(ctx
->task
);
946 call_rcu(&ctx
->rcu_head
, free_ctx
);
951 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
952 * perf_pmu_migrate_context() we need some magic.
954 * Those places that change perf_event::ctx will hold both
955 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
957 * Lock ordering is by mutex address. There are two other sites where
958 * perf_event_context::mutex nests and those are:
960 * - perf_event_exit_task_context() [ child , 0 ]
961 * __perf_event_exit_task()
963 * put_event() [ parent, 1 ]
965 * - perf_event_init_context() [ parent, 0 ]
966 * inherit_task_group()
971 * perf_try_init_event() [ child , 1 ]
973 * While it appears there is an obvious deadlock here -- the parent and child
974 * nesting levels are inverted between the two. This is in fact safe because
975 * life-time rules separate them. That is an exiting task cannot fork, and a
976 * spawning task cannot (yet) exit.
978 * But remember that that these are parent<->child context relations, and
979 * migration does not affect children, therefore these two orderings should not
982 * The change in perf_event::ctx does not affect children (as claimed above)
983 * because the sys_perf_event_open() case will install a new event and break
984 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
985 * concerned with cpuctx and that doesn't have children.
987 * The places that change perf_event::ctx will issue:
989 * perf_remove_from_context();
991 * perf_install_in_context();
993 * to affect the change. The remove_from_context() + synchronize_rcu() should
994 * quiesce the event, after which we can install it in the new location. This
995 * means that only external vectors (perf_fops, prctl) can perturb the event
996 * while in transit. Therefore all such accessors should also acquire
997 * perf_event_context::mutex to serialize against this.
999 * However; because event->ctx can change while we're waiting to acquire
1000 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1004 * task_struct::perf_event_mutex
1005 * perf_event_context::mutex
1006 * perf_event_context::lock
1007 * perf_event::child_mutex;
1008 * perf_event::mmap_mutex
1011 static struct perf_event_context
*
1012 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1014 struct perf_event_context
*ctx
;
1018 ctx
= ACCESS_ONCE(event
->ctx
);
1019 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1025 mutex_lock_nested(&ctx
->mutex
, nesting
);
1026 if (event
->ctx
!= ctx
) {
1027 mutex_unlock(&ctx
->mutex
);
1035 static inline struct perf_event_context
*
1036 perf_event_ctx_lock(struct perf_event
*event
)
1038 return perf_event_ctx_lock_nested(event
, 0);
1041 static void perf_event_ctx_unlock(struct perf_event
*event
,
1042 struct perf_event_context
*ctx
)
1044 mutex_unlock(&ctx
->mutex
);
1049 * This must be done under the ctx->lock, such as to serialize against
1050 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1051 * calling scheduler related locks and ctx->lock nests inside those.
1053 static __must_check
struct perf_event_context
*
1054 unclone_ctx(struct perf_event_context
*ctx
)
1056 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1058 lockdep_assert_held(&ctx
->lock
);
1061 ctx
->parent_ctx
= NULL
;
1067 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1070 * only top level events have the pid namespace they were created in
1073 event
= event
->parent
;
1075 return task_tgid_nr_ns(p
, event
->ns
);
1078 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1081 * only top level events have the pid namespace they were created in
1084 event
= event
->parent
;
1086 return task_pid_nr_ns(p
, event
->ns
);
1090 * If we inherit events we want to return the parent event id
1093 static u64
primary_event_id(struct perf_event
*event
)
1098 id
= event
->parent
->id
;
1104 * Get the perf_event_context for a task and lock it.
1105 * This has to cope with with the fact that until it is locked,
1106 * the context could get moved to another task.
1108 static struct perf_event_context
*
1109 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1111 struct perf_event_context
*ctx
;
1115 * One of the few rules of preemptible RCU is that one cannot do
1116 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1117 * part of the read side critical section was irqs-enabled -- see
1118 * rcu_read_unlock_special().
1120 * Since ctx->lock nests under rq->lock we must ensure the entire read
1121 * side critical section has interrupts disabled.
1123 local_irq_save(*flags
);
1125 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1128 * If this context is a clone of another, it might
1129 * get swapped for another underneath us by
1130 * perf_event_task_sched_out, though the
1131 * rcu_read_lock() protects us from any context
1132 * getting freed. Lock the context and check if it
1133 * got swapped before we could get the lock, and retry
1134 * if so. If we locked the right context, then it
1135 * can't get swapped on us any more.
1137 raw_spin_lock(&ctx
->lock
);
1138 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1139 raw_spin_unlock(&ctx
->lock
);
1141 local_irq_restore(*flags
);
1145 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1146 raw_spin_unlock(&ctx
->lock
);
1152 local_irq_restore(*flags
);
1157 * Get the context for a task and increment its pin_count so it
1158 * can't get swapped to another task. This also increments its
1159 * reference count so that the context can't get freed.
1161 static struct perf_event_context
*
1162 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1164 struct perf_event_context
*ctx
;
1165 unsigned long flags
;
1167 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1170 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1175 static void perf_unpin_context(struct perf_event_context
*ctx
)
1177 unsigned long flags
;
1179 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1181 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1185 * Update the record of the current time in a context.
1187 static void update_context_time(struct perf_event_context
*ctx
)
1189 u64 now
= perf_clock();
1191 ctx
->time
+= now
- ctx
->timestamp
;
1192 ctx
->timestamp
= now
;
1195 static u64
perf_event_time(struct perf_event
*event
)
1197 struct perf_event_context
*ctx
= event
->ctx
;
1199 if (is_cgroup_event(event
))
1200 return perf_cgroup_event_time(event
);
1202 return ctx
? ctx
->time
: 0;
1206 * Update the total_time_enabled and total_time_running fields for a event.
1207 * The caller of this function needs to hold the ctx->lock.
1209 static void update_event_times(struct perf_event
*event
)
1211 struct perf_event_context
*ctx
= event
->ctx
;
1214 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1215 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1218 * in cgroup mode, time_enabled represents
1219 * the time the event was enabled AND active
1220 * tasks were in the monitored cgroup. This is
1221 * independent of the activity of the context as
1222 * there may be a mix of cgroup and non-cgroup events.
1224 * That is why we treat cgroup events differently
1227 if (is_cgroup_event(event
))
1228 run_end
= perf_cgroup_event_time(event
);
1229 else if (ctx
->is_active
)
1230 run_end
= ctx
->time
;
1232 run_end
= event
->tstamp_stopped
;
1234 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1236 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1237 run_end
= event
->tstamp_stopped
;
1239 run_end
= perf_event_time(event
);
1241 event
->total_time_running
= run_end
- event
->tstamp_running
;
1246 * Update total_time_enabled and total_time_running for all events in a group.
1248 static void update_group_times(struct perf_event
*leader
)
1250 struct perf_event
*event
;
1252 update_event_times(leader
);
1253 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1254 update_event_times(event
);
1257 static struct list_head
*
1258 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1260 if (event
->attr
.pinned
)
1261 return &ctx
->pinned_groups
;
1263 return &ctx
->flexible_groups
;
1267 * Add a event from the lists for its context.
1268 * Must be called with ctx->mutex and ctx->lock held.
1271 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1273 lockdep_assert_held(&ctx
->lock
);
1275 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1276 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1279 * If we're a stand alone event or group leader, we go to the context
1280 * list, group events are kept attached to the group so that
1281 * perf_group_detach can, at all times, locate all siblings.
1283 if (event
->group_leader
== event
) {
1284 struct list_head
*list
;
1286 if (is_software_event(event
))
1287 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1289 list
= ctx_group_list(event
, ctx
);
1290 list_add_tail(&event
->group_entry
, list
);
1293 if (is_cgroup_event(event
))
1296 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1298 if (event
->attr
.inherit_stat
)
1305 * Initialize event state based on the perf_event_attr::disabled.
1307 static inline void perf_event__state_init(struct perf_event
*event
)
1309 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1310 PERF_EVENT_STATE_INACTIVE
;
1313 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1315 int entry
= sizeof(u64
); /* value */
1319 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1320 size
+= sizeof(u64
);
1322 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1323 size
+= sizeof(u64
);
1325 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1326 entry
+= sizeof(u64
);
1328 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1330 size
+= sizeof(u64
);
1334 event
->read_size
= size
;
1337 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1339 struct perf_sample_data
*data
;
1342 if (sample_type
& PERF_SAMPLE_IP
)
1343 size
+= sizeof(data
->ip
);
1345 if (sample_type
& PERF_SAMPLE_ADDR
)
1346 size
+= sizeof(data
->addr
);
1348 if (sample_type
& PERF_SAMPLE_PERIOD
)
1349 size
+= sizeof(data
->period
);
1351 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1352 size
+= sizeof(data
->weight
);
1354 if (sample_type
& PERF_SAMPLE_READ
)
1355 size
+= event
->read_size
;
1357 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1358 size
+= sizeof(data
->data_src
.val
);
1360 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1361 size
+= sizeof(data
->txn
);
1363 event
->header_size
= size
;
1367 * Called at perf_event creation and when events are attached/detached from a
1370 static void perf_event__header_size(struct perf_event
*event
)
1372 __perf_event_read_size(event
,
1373 event
->group_leader
->nr_siblings
);
1374 __perf_event_header_size(event
, event
->attr
.sample_type
);
1377 static void perf_event__id_header_size(struct perf_event
*event
)
1379 struct perf_sample_data
*data
;
1380 u64 sample_type
= event
->attr
.sample_type
;
1383 if (sample_type
& PERF_SAMPLE_TID
)
1384 size
+= sizeof(data
->tid_entry
);
1386 if (sample_type
& PERF_SAMPLE_TIME
)
1387 size
+= sizeof(data
->time
);
1389 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1390 size
+= sizeof(data
->id
);
1392 if (sample_type
& PERF_SAMPLE_ID
)
1393 size
+= sizeof(data
->id
);
1395 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1396 size
+= sizeof(data
->stream_id
);
1398 if (sample_type
& PERF_SAMPLE_CPU
)
1399 size
+= sizeof(data
->cpu_entry
);
1401 event
->id_header_size
= size
;
1404 static bool perf_event_validate_size(struct perf_event
*event
)
1407 * The values computed here will be over-written when we actually
1410 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1411 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1412 perf_event__id_header_size(event
);
1415 * Sum the lot; should not exceed the 64k limit we have on records.
1416 * Conservative limit to allow for callchains and other variable fields.
1418 if (event
->read_size
+ event
->header_size
+
1419 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1425 static void perf_group_attach(struct perf_event
*event
)
1427 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1430 * We can have double attach due to group movement in perf_event_open.
1432 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1435 event
->attach_state
|= PERF_ATTACH_GROUP
;
1437 if (group_leader
== event
)
1440 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1442 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1443 !is_software_event(event
))
1444 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1446 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1447 group_leader
->nr_siblings
++;
1449 perf_event__header_size(group_leader
);
1451 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1452 perf_event__header_size(pos
);
1456 * Remove a event from the lists for its context.
1457 * Must be called with ctx->mutex and ctx->lock held.
1460 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1462 struct perf_cpu_context
*cpuctx
;
1464 WARN_ON_ONCE(event
->ctx
!= ctx
);
1465 lockdep_assert_held(&ctx
->lock
);
1468 * We can have double detach due to exit/hot-unplug + close.
1470 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1473 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1475 if (is_cgroup_event(event
)) {
1478 * Because cgroup events are always per-cpu events, this will
1479 * always be called from the right CPU.
1481 cpuctx
= __get_cpu_context(ctx
);
1483 * If there are no more cgroup events then clear cgrp to avoid
1484 * stale pointer in update_cgrp_time_from_cpuctx().
1486 if (!ctx
->nr_cgroups
)
1487 cpuctx
->cgrp
= NULL
;
1491 if (event
->attr
.inherit_stat
)
1494 list_del_rcu(&event
->event_entry
);
1496 if (event
->group_leader
== event
)
1497 list_del_init(&event
->group_entry
);
1499 update_group_times(event
);
1502 * If event was in error state, then keep it
1503 * that way, otherwise bogus counts will be
1504 * returned on read(). The only way to get out
1505 * of error state is by explicit re-enabling
1508 if (event
->state
> PERF_EVENT_STATE_OFF
)
1509 event
->state
= PERF_EVENT_STATE_OFF
;
1514 static void perf_group_detach(struct perf_event
*event
)
1516 struct perf_event
*sibling
, *tmp
;
1517 struct list_head
*list
= NULL
;
1520 * We can have double detach due to exit/hot-unplug + close.
1522 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1525 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1528 * If this is a sibling, remove it from its group.
1530 if (event
->group_leader
!= event
) {
1531 list_del_init(&event
->group_entry
);
1532 event
->group_leader
->nr_siblings
--;
1536 if (!list_empty(&event
->group_entry
))
1537 list
= &event
->group_entry
;
1540 * If this was a group event with sibling events then
1541 * upgrade the siblings to singleton events by adding them
1542 * to whatever list we are on.
1544 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1546 list_move_tail(&sibling
->group_entry
, list
);
1547 sibling
->group_leader
= sibling
;
1549 /* Inherit group flags from the previous leader */
1550 sibling
->group_flags
= event
->group_flags
;
1552 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1556 perf_event__header_size(event
->group_leader
);
1558 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1559 perf_event__header_size(tmp
);
1563 * User event without the task.
1565 static bool is_orphaned_event(struct perf_event
*event
)
1567 return event
&& !is_kernel_event(event
) && !event
->owner
;
1571 * Event has a parent but parent's task finished and it's
1572 * alive only because of children holding refference.
1574 static bool is_orphaned_child(struct perf_event
*event
)
1576 return is_orphaned_event(event
->parent
);
1579 static void orphans_remove_work(struct work_struct
*work
);
1581 static void schedule_orphans_remove(struct perf_event_context
*ctx
)
1583 if (!ctx
->task
|| ctx
->orphans_remove_sched
|| !perf_wq
)
1586 if (queue_delayed_work(perf_wq
, &ctx
->orphans_remove
, 1)) {
1588 ctx
->orphans_remove_sched
= true;
1592 static int __init
perf_workqueue_init(void)
1594 perf_wq
= create_singlethread_workqueue("perf");
1595 WARN(!perf_wq
, "failed to create perf workqueue\n");
1596 return perf_wq
? 0 : -1;
1599 core_initcall(perf_workqueue_init
);
1601 static inline int pmu_filter_match(struct perf_event
*event
)
1603 struct pmu
*pmu
= event
->pmu
;
1604 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1608 event_filter_match(struct perf_event
*event
)
1610 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1611 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1615 event_sched_out(struct perf_event
*event
,
1616 struct perf_cpu_context
*cpuctx
,
1617 struct perf_event_context
*ctx
)
1619 u64 tstamp
= perf_event_time(event
);
1622 WARN_ON_ONCE(event
->ctx
!= ctx
);
1623 lockdep_assert_held(&ctx
->lock
);
1626 * An event which could not be activated because of
1627 * filter mismatch still needs to have its timings
1628 * maintained, otherwise bogus information is return
1629 * via read() for time_enabled, time_running:
1631 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1632 && !event_filter_match(event
)) {
1633 delta
= tstamp
- event
->tstamp_stopped
;
1634 event
->tstamp_running
+= delta
;
1635 event
->tstamp_stopped
= tstamp
;
1638 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1641 perf_pmu_disable(event
->pmu
);
1643 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1644 if (event
->pending_disable
) {
1645 event
->pending_disable
= 0;
1646 event
->state
= PERF_EVENT_STATE_OFF
;
1648 event
->tstamp_stopped
= tstamp
;
1649 event
->pmu
->del(event
, 0);
1652 if (!is_software_event(event
))
1653 cpuctx
->active_oncpu
--;
1654 if (!--ctx
->nr_active
)
1655 perf_event_ctx_deactivate(ctx
);
1656 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1658 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1659 cpuctx
->exclusive
= 0;
1661 if (is_orphaned_child(event
))
1662 schedule_orphans_remove(ctx
);
1664 perf_pmu_enable(event
->pmu
);
1668 group_sched_out(struct perf_event
*group_event
,
1669 struct perf_cpu_context
*cpuctx
,
1670 struct perf_event_context
*ctx
)
1672 struct perf_event
*event
;
1673 int state
= group_event
->state
;
1675 event_sched_out(group_event
, cpuctx
, ctx
);
1678 * Schedule out siblings (if any):
1680 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1681 event_sched_out(event
, cpuctx
, ctx
);
1683 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1684 cpuctx
->exclusive
= 0;
1687 struct remove_event
{
1688 struct perf_event
*event
;
1692 static void ___perf_remove_from_context(void *info
)
1694 struct remove_event
*re
= info
;
1695 struct perf_event
*event
= re
->event
;
1696 struct perf_event_context
*ctx
= event
->ctx
;
1698 if (re
->detach_group
)
1699 perf_group_detach(event
);
1700 list_del_event(event
, ctx
);
1704 * Cross CPU call to remove a performance event
1706 * We disable the event on the hardware level first. After that we
1707 * remove it from the context list.
1709 static int __perf_remove_from_context(void *info
)
1711 struct remove_event
*re
= info
;
1712 struct perf_event
*event
= re
->event
;
1713 struct perf_event_context
*ctx
= event
->ctx
;
1714 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1716 raw_spin_lock(&ctx
->lock
);
1717 event_sched_out(event
, cpuctx
, ctx
);
1718 if (re
->detach_group
)
1719 perf_group_detach(event
);
1720 list_del_event(event
, ctx
);
1722 if (!ctx
->nr_events
&& ctx
->is_active
) {
1725 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1726 cpuctx
->task_ctx
= NULL
;
1729 raw_spin_unlock(&ctx
->lock
);
1735 * Remove the event from a task's (or a CPU's) list of events.
1737 * CPU events are removed with a smp call. For task events we only
1738 * call when the task is on a CPU.
1740 * If event->ctx is a cloned context, callers must make sure that
1741 * every task struct that event->ctx->task could possibly point to
1742 * remains valid. This is OK when called from perf_release since
1743 * that only calls us on the top-level context, which can't be a clone.
1744 * When called from perf_event_exit_task, it's OK because the
1745 * context has been detached from its task.
1747 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1749 struct perf_event_context
*ctx
= event
->ctx
;
1750 struct remove_event re
= {
1752 .detach_group
= detach_group
,
1755 lockdep_assert_held(&ctx
->mutex
);
1757 event_function_call(event
, __perf_remove_from_context
,
1758 ___perf_remove_from_context
, &re
);
1762 * Cross CPU call to disable a performance event
1764 int __perf_event_disable(void *info
)
1766 struct perf_event
*event
= info
;
1767 struct perf_event_context
*ctx
= event
->ctx
;
1768 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1771 * If this is a per-task event, need to check whether this
1772 * event's task is the current task on this cpu.
1774 * Can trigger due to concurrent perf_event_context_sched_out()
1775 * flipping contexts around.
1777 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1780 raw_spin_lock(&ctx
->lock
);
1783 * If the event is on, turn it off.
1784 * If it is in error state, leave it in error state.
1786 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1787 update_context_time(ctx
);
1788 update_cgrp_time_from_event(event
);
1789 update_group_times(event
);
1790 if (event
== event
->group_leader
)
1791 group_sched_out(event
, cpuctx
, ctx
);
1793 event_sched_out(event
, cpuctx
, ctx
);
1794 event
->state
= PERF_EVENT_STATE_OFF
;
1797 raw_spin_unlock(&ctx
->lock
);
1802 void ___perf_event_disable(void *info
)
1804 struct perf_event
*event
= info
;
1807 * Since we have the lock this context can't be scheduled
1808 * in, so we can change the state safely.
1810 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1811 update_group_times(event
);
1812 event
->state
= PERF_EVENT_STATE_OFF
;
1819 * If event->ctx is a cloned context, callers must make sure that
1820 * every task struct that event->ctx->task could possibly point to
1821 * remains valid. This condition is satisifed when called through
1822 * perf_event_for_each_child or perf_event_for_each because they
1823 * hold the top-level event's child_mutex, so any descendant that
1824 * goes to exit will block in sync_child_event.
1825 * When called from perf_pending_event it's OK because event->ctx
1826 * is the current context on this CPU and preemption is disabled,
1827 * hence we can't get into perf_event_task_sched_out for this context.
1829 static void _perf_event_disable(struct perf_event
*event
)
1831 struct perf_event_context
*ctx
= event
->ctx
;
1833 raw_spin_lock_irq(&ctx
->lock
);
1834 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1835 raw_spin_unlock_irq(&ctx
->lock
);
1838 raw_spin_unlock_irq(&ctx
->lock
);
1840 event_function_call(event
, __perf_event_disable
,
1841 ___perf_event_disable
, event
);
1845 * Strictly speaking kernel users cannot create groups and therefore this
1846 * interface does not need the perf_event_ctx_lock() magic.
1848 void perf_event_disable(struct perf_event
*event
)
1850 struct perf_event_context
*ctx
;
1852 ctx
= perf_event_ctx_lock(event
);
1853 _perf_event_disable(event
);
1854 perf_event_ctx_unlock(event
, ctx
);
1856 EXPORT_SYMBOL_GPL(perf_event_disable
);
1858 static void perf_set_shadow_time(struct perf_event
*event
,
1859 struct perf_event_context
*ctx
,
1863 * use the correct time source for the time snapshot
1865 * We could get by without this by leveraging the
1866 * fact that to get to this function, the caller
1867 * has most likely already called update_context_time()
1868 * and update_cgrp_time_xx() and thus both timestamp
1869 * are identical (or very close). Given that tstamp is,
1870 * already adjusted for cgroup, we could say that:
1871 * tstamp - ctx->timestamp
1873 * tstamp - cgrp->timestamp.
1875 * Then, in perf_output_read(), the calculation would
1876 * work with no changes because:
1877 * - event is guaranteed scheduled in
1878 * - no scheduled out in between
1879 * - thus the timestamp would be the same
1881 * But this is a bit hairy.
1883 * So instead, we have an explicit cgroup call to remain
1884 * within the time time source all along. We believe it
1885 * is cleaner and simpler to understand.
1887 if (is_cgroup_event(event
))
1888 perf_cgroup_set_shadow_time(event
, tstamp
);
1890 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1893 #define MAX_INTERRUPTS (~0ULL)
1895 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1896 static void perf_log_itrace_start(struct perf_event
*event
);
1899 event_sched_in(struct perf_event
*event
,
1900 struct perf_cpu_context
*cpuctx
,
1901 struct perf_event_context
*ctx
)
1903 u64 tstamp
= perf_event_time(event
);
1906 lockdep_assert_held(&ctx
->lock
);
1908 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1911 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1912 event
->oncpu
= smp_processor_id();
1915 * Unthrottle events, since we scheduled we might have missed several
1916 * ticks already, also for a heavily scheduling task there is little
1917 * guarantee it'll get a tick in a timely manner.
1919 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1920 perf_log_throttle(event
, 1);
1921 event
->hw
.interrupts
= 0;
1925 * The new state must be visible before we turn it on in the hardware:
1929 perf_pmu_disable(event
->pmu
);
1931 perf_set_shadow_time(event
, ctx
, tstamp
);
1933 perf_log_itrace_start(event
);
1935 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1936 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1942 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1944 if (!is_software_event(event
))
1945 cpuctx
->active_oncpu
++;
1946 if (!ctx
->nr_active
++)
1947 perf_event_ctx_activate(ctx
);
1948 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1951 if (event
->attr
.exclusive
)
1952 cpuctx
->exclusive
= 1;
1954 if (is_orphaned_child(event
))
1955 schedule_orphans_remove(ctx
);
1958 perf_pmu_enable(event
->pmu
);
1964 group_sched_in(struct perf_event
*group_event
,
1965 struct perf_cpu_context
*cpuctx
,
1966 struct perf_event_context
*ctx
)
1968 struct perf_event
*event
, *partial_group
= NULL
;
1969 struct pmu
*pmu
= ctx
->pmu
;
1970 u64 now
= ctx
->time
;
1971 bool simulate
= false;
1973 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1976 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
1978 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1979 pmu
->cancel_txn(pmu
);
1980 perf_mux_hrtimer_restart(cpuctx
);
1985 * Schedule in siblings as one group (if any):
1987 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1988 if (event_sched_in(event
, cpuctx
, ctx
)) {
1989 partial_group
= event
;
1994 if (!pmu
->commit_txn(pmu
))
1999 * Groups can be scheduled in as one unit only, so undo any
2000 * partial group before returning:
2001 * The events up to the failed event are scheduled out normally,
2002 * tstamp_stopped will be updated.
2004 * The failed events and the remaining siblings need to have
2005 * their timings updated as if they had gone thru event_sched_in()
2006 * and event_sched_out(). This is required to get consistent timings
2007 * across the group. This also takes care of the case where the group
2008 * could never be scheduled by ensuring tstamp_stopped is set to mark
2009 * the time the event was actually stopped, such that time delta
2010 * calculation in update_event_times() is correct.
2012 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2013 if (event
== partial_group
)
2017 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2018 event
->tstamp_stopped
= now
;
2020 event_sched_out(event
, cpuctx
, ctx
);
2023 event_sched_out(group_event
, cpuctx
, ctx
);
2025 pmu
->cancel_txn(pmu
);
2027 perf_mux_hrtimer_restart(cpuctx
);
2033 * Work out whether we can put this event group on the CPU now.
2035 static int group_can_go_on(struct perf_event
*event
,
2036 struct perf_cpu_context
*cpuctx
,
2040 * Groups consisting entirely of software events can always go on.
2042 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2045 * If an exclusive group is already on, no other hardware
2048 if (cpuctx
->exclusive
)
2051 * If this group is exclusive and there are already
2052 * events on the CPU, it can't go on.
2054 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2057 * Otherwise, try to add it if all previous groups were able
2063 static void add_event_to_ctx(struct perf_event
*event
,
2064 struct perf_event_context
*ctx
)
2066 u64 tstamp
= perf_event_time(event
);
2068 list_add_event(event
, ctx
);
2069 perf_group_attach(event
);
2070 event
->tstamp_enabled
= tstamp
;
2071 event
->tstamp_running
= tstamp
;
2072 event
->tstamp_stopped
= tstamp
;
2075 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2076 struct perf_event_context
*ctx
);
2078 ctx_sched_in(struct perf_event_context
*ctx
,
2079 struct perf_cpu_context
*cpuctx
,
2080 enum event_type_t event_type
,
2081 struct task_struct
*task
);
2083 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2084 struct perf_event_context
*ctx
,
2085 struct task_struct
*task
)
2087 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2089 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2090 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2092 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2095 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2096 struct perf_event_context
*task_ctx
)
2098 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2100 task_ctx_sched_out(cpuctx
, task_ctx
);
2101 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2102 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2103 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2107 * Cross CPU call to install and enable a performance event
2109 * Must be called with ctx->mutex held
2111 static int __perf_install_in_context(void *info
)
2113 struct perf_event_context
*ctx
= info
;
2114 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2115 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2119 * If we hit the 'wrong' task, we've since scheduled and
2120 * everything should be sorted, nothing to do!
2122 if (ctx
->task
!= current
)
2126 * If task_ctx is set, it had better be to us.
2128 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
&& cpuctx
->task_ctx
);
2132 perf_ctx_lock(cpuctx
, task_ctx
);
2133 ctx_resched(cpuctx
, task_ctx
);
2134 perf_ctx_unlock(cpuctx
, task_ctx
);
2140 * Attach a performance event to a context
2143 perf_install_in_context(struct perf_event_context
*ctx
,
2144 struct perf_event
*event
,
2147 struct task_struct
*task
= NULL
;
2149 lockdep_assert_held(&ctx
->mutex
);
2152 if (event
->cpu
!= -1)
2156 * Installing events is tricky because we cannot rely on ctx->is_active
2157 * to be set in case this is the nr_events 0 -> 1 transition.
2159 * So what we do is we add the event to the list here, which will allow
2160 * a future context switch to DTRT and then send a racy IPI. If the IPI
2161 * fails to hit the right task, this means a context switch must have
2162 * happened and that will have taken care of business.
2164 raw_spin_lock_irq(&ctx
->lock
);
2165 update_context_time(ctx
);
2167 * Update cgrp time only if current cgrp matches event->cgrp.
2168 * Must be done before calling add_event_to_ctx().
2170 update_cgrp_time_from_event(event
);
2171 add_event_to_ctx(event
, ctx
);
2173 raw_spin_unlock_irq(&ctx
->lock
);
2176 task_function_call(task
, __perf_install_in_context
, ctx
);
2178 cpu_function_call(cpu
, __perf_install_in_context
, ctx
);
2182 * Put a event into inactive state and update time fields.
2183 * Enabling the leader of a group effectively enables all
2184 * the group members that aren't explicitly disabled, so we
2185 * have to update their ->tstamp_enabled also.
2186 * Note: this works for group members as well as group leaders
2187 * since the non-leader members' sibling_lists will be empty.
2189 static void __perf_event_mark_enabled(struct perf_event
*event
)
2191 struct perf_event
*sub
;
2192 u64 tstamp
= perf_event_time(event
);
2194 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2195 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2196 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2197 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2198 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2203 * Cross CPU call to enable a performance event
2205 static int __perf_event_enable(void *info
)
2207 struct perf_event
*event
= info
;
2208 struct perf_event_context
*ctx
= event
->ctx
;
2209 struct perf_event
*leader
= event
->group_leader
;
2210 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2211 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2214 * There's a time window between 'ctx->is_active' check
2215 * in perf_event_enable function and this place having:
2217 * - ctx->lock unlocked
2219 * where the task could be killed and 'ctx' deactivated
2220 * by perf_event_exit_task.
2222 if (!ctx
->is_active
)
2225 perf_ctx_lock(cpuctx
, task_ctx
);
2226 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
&& task_ctx
!= ctx
);
2227 update_context_time(ctx
);
2229 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2233 * set current task's cgroup time reference point
2235 perf_cgroup_set_timestamp(current
, ctx
);
2237 __perf_event_mark_enabled(event
);
2239 if (!event_filter_match(event
)) {
2240 if (is_cgroup_event(event
))
2241 perf_cgroup_defer_enabled(event
);
2246 * If the event is in a group and isn't the group leader,
2247 * then don't put it on unless the group is on.
2249 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2252 ctx_resched(cpuctx
, task_ctx
);
2255 perf_ctx_unlock(cpuctx
, task_ctx
);
2260 void ___perf_event_enable(void *info
)
2262 __perf_event_mark_enabled((struct perf_event
*)info
);
2268 * If event->ctx is a cloned context, callers must make sure that
2269 * every task struct that event->ctx->task could possibly point to
2270 * remains valid. This condition is satisfied when called through
2271 * perf_event_for_each_child or perf_event_for_each as described
2272 * for perf_event_disable.
2274 static void _perf_event_enable(struct perf_event
*event
)
2276 struct perf_event_context
*ctx
= event
->ctx
;
2278 raw_spin_lock_irq(&ctx
->lock
);
2279 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
2280 raw_spin_unlock_irq(&ctx
->lock
);
2285 * If the event is in error state, clear that first.
2287 * That way, if we see the event in error state below, we know that it
2288 * has gone back into error state, as distinct from the task having
2289 * been scheduled away before the cross-call arrived.
2291 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2292 event
->state
= PERF_EVENT_STATE_OFF
;
2293 raw_spin_unlock_irq(&ctx
->lock
);
2295 event_function_call(event
, __perf_event_enable
,
2296 ___perf_event_enable
, event
);
2300 * See perf_event_disable();
2302 void perf_event_enable(struct perf_event
*event
)
2304 struct perf_event_context
*ctx
;
2306 ctx
= perf_event_ctx_lock(event
);
2307 _perf_event_enable(event
);
2308 perf_event_ctx_unlock(event
, ctx
);
2310 EXPORT_SYMBOL_GPL(perf_event_enable
);
2312 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2315 * not supported on inherited events
2317 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2320 atomic_add(refresh
, &event
->event_limit
);
2321 _perf_event_enable(event
);
2327 * See perf_event_disable()
2329 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2331 struct perf_event_context
*ctx
;
2334 ctx
= perf_event_ctx_lock(event
);
2335 ret
= _perf_event_refresh(event
, refresh
);
2336 perf_event_ctx_unlock(event
, ctx
);
2340 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2342 static void ctx_sched_out(struct perf_event_context
*ctx
,
2343 struct perf_cpu_context
*cpuctx
,
2344 enum event_type_t event_type
)
2346 int is_active
= ctx
->is_active
;
2347 struct perf_event
*event
;
2349 lockdep_assert_held(&ctx
->lock
);
2351 if (likely(!ctx
->nr_events
)) {
2353 * See __perf_remove_from_context().
2355 WARN_ON_ONCE(ctx
->is_active
);
2357 WARN_ON_ONCE(cpuctx
->task_ctx
);
2361 ctx
->is_active
&= ~event_type
;
2363 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2364 if (!ctx
->is_active
)
2365 cpuctx
->task_ctx
= NULL
;
2368 update_context_time(ctx
);
2369 update_cgrp_time_from_cpuctx(cpuctx
);
2370 if (!ctx
->nr_active
)
2373 perf_pmu_disable(ctx
->pmu
);
2374 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2375 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2376 group_sched_out(event
, cpuctx
, ctx
);
2379 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2380 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2381 group_sched_out(event
, cpuctx
, ctx
);
2383 perf_pmu_enable(ctx
->pmu
);
2387 * Test whether two contexts are equivalent, i.e. whether they have both been
2388 * cloned from the same version of the same context.
2390 * Equivalence is measured using a generation number in the context that is
2391 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2392 * and list_del_event().
2394 static int context_equiv(struct perf_event_context
*ctx1
,
2395 struct perf_event_context
*ctx2
)
2397 lockdep_assert_held(&ctx1
->lock
);
2398 lockdep_assert_held(&ctx2
->lock
);
2400 /* Pinning disables the swap optimization */
2401 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2404 /* If ctx1 is the parent of ctx2 */
2405 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2408 /* If ctx2 is the parent of ctx1 */
2409 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2413 * If ctx1 and ctx2 have the same parent; we flatten the parent
2414 * hierarchy, see perf_event_init_context().
2416 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2417 ctx1
->parent_gen
== ctx2
->parent_gen
)
2424 static void __perf_event_sync_stat(struct perf_event
*event
,
2425 struct perf_event
*next_event
)
2429 if (!event
->attr
.inherit_stat
)
2433 * Update the event value, we cannot use perf_event_read()
2434 * because we're in the middle of a context switch and have IRQs
2435 * disabled, which upsets smp_call_function_single(), however
2436 * we know the event must be on the current CPU, therefore we
2437 * don't need to use it.
2439 switch (event
->state
) {
2440 case PERF_EVENT_STATE_ACTIVE
:
2441 event
->pmu
->read(event
);
2444 case PERF_EVENT_STATE_INACTIVE
:
2445 update_event_times(event
);
2453 * In order to keep per-task stats reliable we need to flip the event
2454 * values when we flip the contexts.
2456 value
= local64_read(&next_event
->count
);
2457 value
= local64_xchg(&event
->count
, value
);
2458 local64_set(&next_event
->count
, value
);
2460 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2461 swap(event
->total_time_running
, next_event
->total_time_running
);
2464 * Since we swizzled the values, update the user visible data too.
2466 perf_event_update_userpage(event
);
2467 perf_event_update_userpage(next_event
);
2470 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2471 struct perf_event_context
*next_ctx
)
2473 struct perf_event
*event
, *next_event
;
2478 update_context_time(ctx
);
2480 event
= list_first_entry(&ctx
->event_list
,
2481 struct perf_event
, event_entry
);
2483 next_event
= list_first_entry(&next_ctx
->event_list
,
2484 struct perf_event
, event_entry
);
2486 while (&event
->event_entry
!= &ctx
->event_list
&&
2487 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2489 __perf_event_sync_stat(event
, next_event
);
2491 event
= list_next_entry(event
, event_entry
);
2492 next_event
= list_next_entry(next_event
, event_entry
);
2496 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2497 struct task_struct
*next
)
2499 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2500 struct perf_event_context
*next_ctx
;
2501 struct perf_event_context
*parent
, *next_parent
;
2502 struct perf_cpu_context
*cpuctx
;
2508 cpuctx
= __get_cpu_context(ctx
);
2509 if (!cpuctx
->task_ctx
)
2513 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2517 parent
= rcu_dereference(ctx
->parent_ctx
);
2518 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2520 /* If neither context have a parent context; they cannot be clones. */
2521 if (!parent
&& !next_parent
)
2524 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2526 * Looks like the two contexts are clones, so we might be
2527 * able to optimize the context switch. We lock both
2528 * contexts and check that they are clones under the
2529 * lock (including re-checking that neither has been
2530 * uncloned in the meantime). It doesn't matter which
2531 * order we take the locks because no other cpu could
2532 * be trying to lock both of these tasks.
2534 raw_spin_lock(&ctx
->lock
);
2535 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2536 if (context_equiv(ctx
, next_ctx
)) {
2538 * XXX do we need a memory barrier of sorts
2539 * wrt to rcu_dereference() of perf_event_ctxp
2541 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2542 next
->perf_event_ctxp
[ctxn
] = ctx
;
2544 next_ctx
->task
= task
;
2546 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2550 perf_event_sync_stat(ctx
, next_ctx
);
2552 raw_spin_unlock(&next_ctx
->lock
);
2553 raw_spin_unlock(&ctx
->lock
);
2559 raw_spin_lock(&ctx
->lock
);
2560 task_ctx_sched_out(cpuctx
, ctx
);
2561 raw_spin_unlock(&ctx
->lock
);
2565 void perf_sched_cb_dec(struct pmu
*pmu
)
2567 this_cpu_dec(perf_sched_cb_usages
);
2570 void perf_sched_cb_inc(struct pmu
*pmu
)
2572 this_cpu_inc(perf_sched_cb_usages
);
2576 * This function provides the context switch callback to the lower code
2577 * layer. It is invoked ONLY when the context switch callback is enabled.
2579 static void perf_pmu_sched_task(struct task_struct
*prev
,
2580 struct task_struct
*next
,
2583 struct perf_cpu_context
*cpuctx
;
2585 unsigned long flags
;
2590 local_irq_save(flags
);
2594 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2595 if (pmu
->sched_task
) {
2596 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2598 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2600 perf_pmu_disable(pmu
);
2602 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2604 perf_pmu_enable(pmu
);
2606 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2612 local_irq_restore(flags
);
2615 static void perf_event_switch(struct task_struct
*task
,
2616 struct task_struct
*next_prev
, bool sched_in
);
2618 #define for_each_task_context_nr(ctxn) \
2619 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2622 * Called from scheduler to remove the events of the current task,
2623 * with interrupts disabled.
2625 * We stop each event and update the event value in event->count.
2627 * This does not protect us against NMI, but disable()
2628 * sets the disabled bit in the control field of event _before_
2629 * accessing the event control register. If a NMI hits, then it will
2630 * not restart the event.
2632 void __perf_event_task_sched_out(struct task_struct
*task
,
2633 struct task_struct
*next
)
2637 if (__this_cpu_read(perf_sched_cb_usages
))
2638 perf_pmu_sched_task(task
, next
, false);
2640 if (atomic_read(&nr_switch_events
))
2641 perf_event_switch(task
, next
, false);
2643 for_each_task_context_nr(ctxn
)
2644 perf_event_context_sched_out(task
, ctxn
, next
);
2647 * if cgroup events exist on this CPU, then we need
2648 * to check if we have to switch out PMU state.
2649 * cgroup event are system-wide mode only
2651 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2652 perf_cgroup_sched_out(task
, next
);
2655 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2656 struct perf_event_context
*ctx
)
2658 if (!cpuctx
->task_ctx
)
2661 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2664 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2668 * Called with IRQs disabled
2670 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2671 enum event_type_t event_type
)
2673 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2677 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2678 struct perf_cpu_context
*cpuctx
)
2680 struct perf_event
*event
;
2682 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2683 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2685 if (!event_filter_match(event
))
2688 /* may need to reset tstamp_enabled */
2689 if (is_cgroup_event(event
))
2690 perf_cgroup_mark_enabled(event
, ctx
);
2692 if (group_can_go_on(event
, cpuctx
, 1))
2693 group_sched_in(event
, cpuctx
, ctx
);
2696 * If this pinned group hasn't been scheduled,
2697 * put it in error state.
2699 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2700 update_group_times(event
);
2701 event
->state
= PERF_EVENT_STATE_ERROR
;
2707 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2708 struct perf_cpu_context
*cpuctx
)
2710 struct perf_event
*event
;
2713 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2714 /* Ignore events in OFF or ERROR state */
2715 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2718 * Listen to the 'cpu' scheduling filter constraint
2721 if (!event_filter_match(event
))
2724 /* may need to reset tstamp_enabled */
2725 if (is_cgroup_event(event
))
2726 perf_cgroup_mark_enabled(event
, ctx
);
2728 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2729 if (group_sched_in(event
, cpuctx
, ctx
))
2736 ctx_sched_in(struct perf_event_context
*ctx
,
2737 struct perf_cpu_context
*cpuctx
,
2738 enum event_type_t event_type
,
2739 struct task_struct
*task
)
2741 int is_active
= ctx
->is_active
;
2744 lockdep_assert_held(&ctx
->lock
);
2746 if (likely(!ctx
->nr_events
))
2749 ctx
->is_active
|= event_type
;
2752 cpuctx
->task_ctx
= ctx
;
2754 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2758 ctx
->timestamp
= now
;
2759 perf_cgroup_set_timestamp(task
, ctx
);
2761 * First go through the list and put on any pinned groups
2762 * in order to give them the best chance of going on.
2764 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2765 ctx_pinned_sched_in(ctx
, cpuctx
);
2767 /* Then walk through the lower prio flexible groups */
2768 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2769 ctx_flexible_sched_in(ctx
, cpuctx
);
2772 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2773 enum event_type_t event_type
,
2774 struct task_struct
*task
)
2776 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2778 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2781 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2782 struct task_struct
*task
)
2784 struct perf_cpu_context
*cpuctx
;
2786 cpuctx
= __get_cpu_context(ctx
);
2787 if (cpuctx
->task_ctx
== ctx
)
2790 perf_ctx_lock(cpuctx
, ctx
);
2791 perf_pmu_disable(ctx
->pmu
);
2793 * We want to keep the following priority order:
2794 * cpu pinned (that don't need to move), task pinned,
2795 * cpu flexible, task flexible.
2797 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2798 perf_event_sched_in(cpuctx
, ctx
, task
);
2799 perf_pmu_enable(ctx
->pmu
);
2800 perf_ctx_unlock(cpuctx
, ctx
);
2804 * Called from scheduler to add the events of the current task
2805 * with interrupts disabled.
2807 * We restore the event value and then enable it.
2809 * This does not protect us against NMI, but enable()
2810 * sets the enabled bit in the control field of event _before_
2811 * accessing the event control register. If a NMI hits, then it will
2812 * keep the event running.
2814 void __perf_event_task_sched_in(struct task_struct
*prev
,
2815 struct task_struct
*task
)
2817 struct perf_event_context
*ctx
;
2821 * If cgroup events exist on this CPU, then we need to check if we have
2822 * to switch in PMU state; cgroup event are system-wide mode only.
2824 * Since cgroup events are CPU events, we must schedule these in before
2825 * we schedule in the task events.
2827 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2828 perf_cgroup_sched_in(prev
, task
);
2830 for_each_task_context_nr(ctxn
) {
2831 ctx
= task
->perf_event_ctxp
[ctxn
];
2835 perf_event_context_sched_in(ctx
, task
);
2838 if (atomic_read(&nr_switch_events
))
2839 perf_event_switch(task
, prev
, true);
2841 if (__this_cpu_read(perf_sched_cb_usages
))
2842 perf_pmu_sched_task(prev
, task
, true);
2845 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2847 u64 frequency
= event
->attr
.sample_freq
;
2848 u64 sec
= NSEC_PER_SEC
;
2849 u64 divisor
, dividend
;
2851 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2853 count_fls
= fls64(count
);
2854 nsec_fls
= fls64(nsec
);
2855 frequency_fls
= fls64(frequency
);
2859 * We got @count in @nsec, with a target of sample_freq HZ
2860 * the target period becomes:
2863 * period = -------------------
2864 * @nsec * sample_freq
2869 * Reduce accuracy by one bit such that @a and @b converge
2870 * to a similar magnitude.
2872 #define REDUCE_FLS(a, b) \
2874 if (a##_fls > b##_fls) { \
2884 * Reduce accuracy until either term fits in a u64, then proceed with
2885 * the other, so that finally we can do a u64/u64 division.
2887 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2888 REDUCE_FLS(nsec
, frequency
);
2889 REDUCE_FLS(sec
, count
);
2892 if (count_fls
+ sec_fls
> 64) {
2893 divisor
= nsec
* frequency
;
2895 while (count_fls
+ sec_fls
> 64) {
2896 REDUCE_FLS(count
, sec
);
2900 dividend
= count
* sec
;
2902 dividend
= count
* sec
;
2904 while (nsec_fls
+ frequency_fls
> 64) {
2905 REDUCE_FLS(nsec
, frequency
);
2909 divisor
= nsec
* frequency
;
2915 return div64_u64(dividend
, divisor
);
2918 static DEFINE_PER_CPU(int, perf_throttled_count
);
2919 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2921 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2923 struct hw_perf_event
*hwc
= &event
->hw
;
2924 s64 period
, sample_period
;
2927 period
= perf_calculate_period(event
, nsec
, count
);
2929 delta
= (s64
)(period
- hwc
->sample_period
);
2930 delta
= (delta
+ 7) / 8; /* low pass filter */
2932 sample_period
= hwc
->sample_period
+ delta
;
2937 hwc
->sample_period
= sample_period
;
2939 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2941 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2943 local64_set(&hwc
->period_left
, 0);
2946 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2951 * combine freq adjustment with unthrottling to avoid two passes over the
2952 * events. At the same time, make sure, having freq events does not change
2953 * the rate of unthrottling as that would introduce bias.
2955 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2958 struct perf_event
*event
;
2959 struct hw_perf_event
*hwc
;
2960 u64 now
, period
= TICK_NSEC
;
2964 * only need to iterate over all events iff:
2965 * - context have events in frequency mode (needs freq adjust)
2966 * - there are events to unthrottle on this cpu
2968 if (!(ctx
->nr_freq
|| needs_unthr
))
2971 raw_spin_lock(&ctx
->lock
);
2972 perf_pmu_disable(ctx
->pmu
);
2974 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2975 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2978 if (!event_filter_match(event
))
2981 perf_pmu_disable(event
->pmu
);
2985 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
2986 hwc
->interrupts
= 0;
2987 perf_log_throttle(event
, 1);
2988 event
->pmu
->start(event
, 0);
2991 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2995 * stop the event and update event->count
2997 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2999 now
= local64_read(&event
->count
);
3000 delta
= now
- hwc
->freq_count_stamp
;
3001 hwc
->freq_count_stamp
= now
;
3005 * reload only if value has changed
3006 * we have stopped the event so tell that
3007 * to perf_adjust_period() to avoid stopping it
3011 perf_adjust_period(event
, period
, delta
, false);
3013 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3015 perf_pmu_enable(event
->pmu
);
3018 perf_pmu_enable(ctx
->pmu
);
3019 raw_spin_unlock(&ctx
->lock
);
3023 * Round-robin a context's events:
3025 static void rotate_ctx(struct perf_event_context
*ctx
)
3028 * Rotate the first entry last of non-pinned groups. Rotation might be
3029 * disabled by the inheritance code.
3031 if (!ctx
->rotate_disable
)
3032 list_rotate_left(&ctx
->flexible_groups
);
3035 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3037 struct perf_event_context
*ctx
= NULL
;
3040 if (cpuctx
->ctx
.nr_events
) {
3041 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3045 ctx
= cpuctx
->task_ctx
;
3046 if (ctx
&& ctx
->nr_events
) {
3047 if (ctx
->nr_events
!= ctx
->nr_active
)
3054 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3055 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3057 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3059 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3061 rotate_ctx(&cpuctx
->ctx
);
3065 perf_event_sched_in(cpuctx
, ctx
, current
);
3067 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3068 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3074 #ifdef CONFIG_NO_HZ_FULL
3075 bool perf_event_can_stop_tick(void)
3077 if (atomic_read(&nr_freq_events
) ||
3078 __this_cpu_read(perf_throttled_count
))
3085 void perf_event_task_tick(void)
3087 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3088 struct perf_event_context
*ctx
, *tmp
;
3091 WARN_ON(!irqs_disabled());
3093 __this_cpu_inc(perf_throttled_seq
);
3094 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3096 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3097 perf_adjust_freq_unthr_context(ctx
, throttled
);
3100 static int event_enable_on_exec(struct perf_event
*event
,
3101 struct perf_event_context
*ctx
)
3103 if (!event
->attr
.enable_on_exec
)
3106 event
->attr
.enable_on_exec
= 0;
3107 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3110 __perf_event_mark_enabled(event
);
3116 * Enable all of a task's events that have been marked enable-on-exec.
3117 * This expects task == current.
3119 static void perf_event_enable_on_exec(int ctxn
)
3121 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3122 struct perf_cpu_context
*cpuctx
;
3123 struct perf_event
*event
;
3124 unsigned long flags
;
3127 local_irq_save(flags
);
3128 ctx
= current
->perf_event_ctxp
[ctxn
];
3129 if (!ctx
|| !ctx
->nr_events
)
3132 cpuctx
= __get_cpu_context(ctx
);
3133 perf_ctx_lock(cpuctx
, ctx
);
3134 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
3135 enabled
|= event_enable_on_exec(event
, ctx
);
3138 * Unclone and reschedule this context if we enabled any event.
3141 clone_ctx
= unclone_ctx(ctx
);
3142 ctx_resched(cpuctx
, ctx
);
3144 perf_ctx_unlock(cpuctx
, ctx
);
3147 local_irq_restore(flags
);
3153 void perf_event_exec(void)
3158 for_each_task_context_nr(ctxn
)
3159 perf_event_enable_on_exec(ctxn
);
3163 struct perf_read_data
{
3164 struct perf_event
*event
;
3170 * Cross CPU call to read the hardware event
3172 static void __perf_event_read(void *info
)
3174 struct perf_read_data
*data
= info
;
3175 struct perf_event
*sub
, *event
= data
->event
;
3176 struct perf_event_context
*ctx
= event
->ctx
;
3177 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3178 struct pmu
*pmu
= event
->pmu
;
3181 * If this is a task context, we need to check whether it is
3182 * the current task context of this cpu. If not it has been
3183 * scheduled out before the smp call arrived. In that case
3184 * event->count would have been updated to a recent sample
3185 * when the event was scheduled out.
3187 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3190 raw_spin_lock(&ctx
->lock
);
3191 if (ctx
->is_active
) {
3192 update_context_time(ctx
);
3193 update_cgrp_time_from_event(event
);
3196 update_event_times(event
);
3197 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3206 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3210 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3211 update_event_times(sub
);
3212 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3214 * Use sibling's PMU rather than @event's since
3215 * sibling could be on different (eg: software) PMU.
3217 sub
->pmu
->read(sub
);
3221 data
->ret
= pmu
->commit_txn(pmu
);
3224 raw_spin_unlock(&ctx
->lock
);
3227 static inline u64
perf_event_count(struct perf_event
*event
)
3229 if (event
->pmu
->count
)
3230 return event
->pmu
->count(event
);
3232 return __perf_event_count(event
);
3236 * NMI-safe method to read a local event, that is an event that
3238 * - either for the current task, or for this CPU
3239 * - does not have inherit set, for inherited task events
3240 * will not be local and we cannot read them atomically
3241 * - must not have a pmu::count method
3243 u64
perf_event_read_local(struct perf_event
*event
)
3245 unsigned long flags
;
3249 * Disabling interrupts avoids all counter scheduling (context
3250 * switches, timer based rotation and IPIs).
3252 local_irq_save(flags
);
3254 /* If this is a per-task event, it must be for current */
3255 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3256 event
->hw
.target
!= current
);
3258 /* If this is a per-CPU event, it must be for this CPU */
3259 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3260 event
->cpu
!= smp_processor_id());
3263 * It must not be an event with inherit set, we cannot read
3264 * all child counters from atomic context.
3266 WARN_ON_ONCE(event
->attr
.inherit
);
3269 * It must not have a pmu::count method, those are not
3272 WARN_ON_ONCE(event
->pmu
->count
);
3275 * If the event is currently on this CPU, its either a per-task event,
3276 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3279 if (event
->oncpu
== smp_processor_id())
3280 event
->pmu
->read(event
);
3282 val
= local64_read(&event
->count
);
3283 local_irq_restore(flags
);
3288 static int perf_event_read(struct perf_event
*event
, bool group
)
3293 * If event is enabled and currently active on a CPU, update the
3294 * value in the event structure:
3296 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3297 struct perf_read_data data
= {
3302 smp_call_function_single(event
->oncpu
,
3303 __perf_event_read
, &data
, 1);
3305 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3306 struct perf_event_context
*ctx
= event
->ctx
;
3307 unsigned long flags
;
3309 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3311 * may read while context is not active
3312 * (e.g., thread is blocked), in that case
3313 * we cannot update context time
3315 if (ctx
->is_active
) {
3316 update_context_time(ctx
);
3317 update_cgrp_time_from_event(event
);
3320 update_group_times(event
);
3322 update_event_times(event
);
3323 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3330 * Initialize the perf_event context in a task_struct:
3332 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3334 raw_spin_lock_init(&ctx
->lock
);
3335 mutex_init(&ctx
->mutex
);
3336 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3337 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3338 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3339 INIT_LIST_HEAD(&ctx
->event_list
);
3340 atomic_set(&ctx
->refcount
, 1);
3341 INIT_DELAYED_WORK(&ctx
->orphans_remove
, orphans_remove_work
);
3344 static struct perf_event_context
*
3345 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3347 struct perf_event_context
*ctx
;
3349 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3353 __perf_event_init_context(ctx
);
3356 get_task_struct(task
);
3363 static struct task_struct
*
3364 find_lively_task_by_vpid(pid_t vpid
)
3366 struct task_struct
*task
;
3373 task
= find_task_by_vpid(vpid
);
3375 get_task_struct(task
);
3379 return ERR_PTR(-ESRCH
);
3381 /* Reuse ptrace permission checks for now. */
3383 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3388 put_task_struct(task
);
3389 return ERR_PTR(err
);
3394 * Returns a matching context with refcount and pincount.
3396 static struct perf_event_context
*
3397 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3398 struct perf_event
*event
)
3400 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3401 struct perf_cpu_context
*cpuctx
;
3402 void *task_ctx_data
= NULL
;
3403 unsigned long flags
;
3405 int cpu
= event
->cpu
;
3408 /* Must be root to operate on a CPU event: */
3409 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3410 return ERR_PTR(-EACCES
);
3413 * We could be clever and allow to attach a event to an
3414 * offline CPU and activate it when the CPU comes up, but
3417 if (!cpu_online(cpu
))
3418 return ERR_PTR(-ENODEV
);
3420 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3429 ctxn
= pmu
->task_ctx_nr
;
3433 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3434 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3435 if (!task_ctx_data
) {
3442 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3444 clone_ctx
= unclone_ctx(ctx
);
3447 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3448 ctx
->task_ctx_data
= task_ctx_data
;
3449 task_ctx_data
= NULL
;
3451 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3456 ctx
= alloc_perf_context(pmu
, task
);
3461 if (task_ctx_data
) {
3462 ctx
->task_ctx_data
= task_ctx_data
;
3463 task_ctx_data
= NULL
;
3467 mutex_lock(&task
->perf_event_mutex
);
3469 * If it has already passed perf_event_exit_task().
3470 * we must see PF_EXITING, it takes this mutex too.
3472 if (task
->flags
& PF_EXITING
)
3474 else if (task
->perf_event_ctxp
[ctxn
])
3479 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3481 mutex_unlock(&task
->perf_event_mutex
);
3483 if (unlikely(err
)) {
3492 kfree(task_ctx_data
);
3496 kfree(task_ctx_data
);
3497 return ERR_PTR(err
);
3500 static void perf_event_free_filter(struct perf_event
*event
);
3501 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3503 static void free_event_rcu(struct rcu_head
*head
)
3505 struct perf_event
*event
;
3507 event
= container_of(head
, struct perf_event
, rcu_head
);
3509 put_pid_ns(event
->ns
);
3510 perf_event_free_filter(event
);
3514 static void ring_buffer_attach(struct perf_event
*event
,
3515 struct ring_buffer
*rb
);
3517 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3522 if (is_cgroup_event(event
))
3523 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3526 static void unaccount_event(struct perf_event
*event
)
3533 if (event
->attach_state
& PERF_ATTACH_TASK
)
3535 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3536 atomic_dec(&nr_mmap_events
);
3537 if (event
->attr
.comm
)
3538 atomic_dec(&nr_comm_events
);
3539 if (event
->attr
.task
)
3540 atomic_dec(&nr_task_events
);
3541 if (event
->attr
.freq
)
3542 atomic_dec(&nr_freq_events
);
3543 if (event
->attr
.context_switch
) {
3545 atomic_dec(&nr_switch_events
);
3547 if (is_cgroup_event(event
))
3549 if (has_branch_stack(event
))
3553 static_key_slow_dec_deferred(&perf_sched_events
);
3555 unaccount_event_cpu(event
, event
->cpu
);
3559 * The following implement mutual exclusion of events on "exclusive" pmus
3560 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3561 * at a time, so we disallow creating events that might conflict, namely:
3563 * 1) cpu-wide events in the presence of per-task events,
3564 * 2) per-task events in the presence of cpu-wide events,
3565 * 3) two matching events on the same context.
3567 * The former two cases are handled in the allocation path (perf_event_alloc(),
3568 * __free_event()), the latter -- before the first perf_install_in_context().
3570 static int exclusive_event_init(struct perf_event
*event
)
3572 struct pmu
*pmu
= event
->pmu
;
3574 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3578 * Prevent co-existence of per-task and cpu-wide events on the
3579 * same exclusive pmu.
3581 * Negative pmu::exclusive_cnt means there are cpu-wide
3582 * events on this "exclusive" pmu, positive means there are
3585 * Since this is called in perf_event_alloc() path, event::ctx
3586 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3587 * to mean "per-task event", because unlike other attach states it
3588 * never gets cleared.
3590 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3591 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3594 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3601 static void exclusive_event_destroy(struct perf_event
*event
)
3603 struct pmu
*pmu
= event
->pmu
;
3605 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3608 /* see comment in exclusive_event_init() */
3609 if (event
->attach_state
& PERF_ATTACH_TASK
)
3610 atomic_dec(&pmu
->exclusive_cnt
);
3612 atomic_inc(&pmu
->exclusive_cnt
);
3615 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3617 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3618 (e1
->cpu
== e2
->cpu
||
3625 /* Called under the same ctx::mutex as perf_install_in_context() */
3626 static bool exclusive_event_installable(struct perf_event
*event
,
3627 struct perf_event_context
*ctx
)
3629 struct perf_event
*iter_event
;
3630 struct pmu
*pmu
= event
->pmu
;
3632 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3635 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3636 if (exclusive_event_match(iter_event
, event
))
3643 static void __free_event(struct perf_event
*event
)
3645 if (!event
->parent
) {
3646 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3647 put_callchain_buffers();
3650 perf_event_free_bpf_prog(event
);
3653 event
->destroy(event
);
3656 put_ctx(event
->ctx
);
3659 exclusive_event_destroy(event
);
3660 module_put(event
->pmu
->module
);
3663 call_rcu(&event
->rcu_head
, free_event_rcu
);
3666 static void _free_event(struct perf_event
*event
)
3668 irq_work_sync(&event
->pending
);
3670 unaccount_event(event
);
3674 * Can happen when we close an event with re-directed output.
3676 * Since we have a 0 refcount, perf_mmap_close() will skip
3677 * over us; possibly making our ring_buffer_put() the last.
3679 mutex_lock(&event
->mmap_mutex
);
3680 ring_buffer_attach(event
, NULL
);
3681 mutex_unlock(&event
->mmap_mutex
);
3684 if (is_cgroup_event(event
))
3685 perf_detach_cgroup(event
);
3687 __free_event(event
);
3691 * Used to free events which have a known refcount of 1, such as in error paths
3692 * where the event isn't exposed yet and inherited events.
3694 static void free_event(struct perf_event
*event
)
3696 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3697 "unexpected event refcount: %ld; ptr=%p\n",
3698 atomic_long_read(&event
->refcount
), event
)) {
3699 /* leak to avoid use-after-free */
3707 * Remove user event from the owner task.
3709 static void perf_remove_from_owner(struct perf_event
*event
)
3711 struct task_struct
*owner
;
3714 owner
= ACCESS_ONCE(event
->owner
);
3716 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3717 * !owner it means the list deletion is complete and we can indeed
3718 * free this event, otherwise we need to serialize on
3719 * owner->perf_event_mutex.
3721 smp_read_barrier_depends();
3724 * Since delayed_put_task_struct() also drops the last
3725 * task reference we can safely take a new reference
3726 * while holding the rcu_read_lock().
3728 get_task_struct(owner
);
3734 * If we're here through perf_event_exit_task() we're already
3735 * holding ctx->mutex which would be an inversion wrt. the
3736 * normal lock order.
3738 * However we can safely take this lock because its the child
3741 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3744 * We have to re-check the event->owner field, if it is cleared
3745 * we raced with perf_event_exit_task(), acquiring the mutex
3746 * ensured they're done, and we can proceed with freeing the
3750 list_del_init(&event
->owner_entry
);
3751 mutex_unlock(&owner
->perf_event_mutex
);
3752 put_task_struct(owner
);
3756 static void put_event(struct perf_event
*event
)
3758 struct perf_event_context
*ctx
;
3760 if (!atomic_long_dec_and_test(&event
->refcount
))
3763 if (!is_kernel_event(event
))
3764 perf_remove_from_owner(event
);
3767 * There are two ways this annotation is useful:
3769 * 1) there is a lock recursion from perf_event_exit_task
3770 * see the comment there.
3772 * 2) there is a lock-inversion with mmap_sem through
3773 * perf_read_group(), which takes faults while
3774 * holding ctx->mutex, however this is called after
3775 * the last filedesc died, so there is no possibility
3776 * to trigger the AB-BA case.
3778 ctx
= perf_event_ctx_lock_nested(event
, SINGLE_DEPTH_NESTING
);
3779 WARN_ON_ONCE(ctx
->parent_ctx
);
3780 perf_remove_from_context(event
, true);
3781 perf_event_ctx_unlock(event
, ctx
);
3786 int perf_event_release_kernel(struct perf_event
*event
)
3791 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3794 * Called when the last reference to the file is gone.
3796 static int perf_release(struct inode
*inode
, struct file
*file
)
3798 put_event(file
->private_data
);
3803 * Remove all orphanes events from the context.
3805 static void orphans_remove_work(struct work_struct
*work
)
3807 struct perf_event_context
*ctx
;
3808 struct perf_event
*event
, *tmp
;
3810 ctx
= container_of(work
, struct perf_event_context
,
3811 orphans_remove
.work
);
3813 mutex_lock(&ctx
->mutex
);
3814 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
) {
3815 struct perf_event
*parent_event
= event
->parent
;
3817 if (!is_orphaned_child(event
))
3820 perf_remove_from_context(event
, true);
3822 mutex_lock(&parent_event
->child_mutex
);
3823 list_del_init(&event
->child_list
);
3824 mutex_unlock(&parent_event
->child_mutex
);
3827 put_event(parent_event
);
3830 raw_spin_lock_irq(&ctx
->lock
);
3831 ctx
->orphans_remove_sched
= false;
3832 raw_spin_unlock_irq(&ctx
->lock
);
3833 mutex_unlock(&ctx
->mutex
);
3838 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3840 struct perf_event
*child
;
3846 mutex_lock(&event
->child_mutex
);
3848 (void)perf_event_read(event
, false);
3849 total
+= perf_event_count(event
);
3851 *enabled
+= event
->total_time_enabled
+
3852 atomic64_read(&event
->child_total_time_enabled
);
3853 *running
+= event
->total_time_running
+
3854 atomic64_read(&event
->child_total_time_running
);
3856 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3857 (void)perf_event_read(child
, false);
3858 total
+= perf_event_count(child
);
3859 *enabled
+= child
->total_time_enabled
;
3860 *running
+= child
->total_time_running
;
3862 mutex_unlock(&event
->child_mutex
);
3866 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3868 static int __perf_read_group_add(struct perf_event
*leader
,
3869 u64 read_format
, u64
*values
)
3871 struct perf_event
*sub
;
3872 int n
= 1; /* skip @nr */
3875 ret
= perf_event_read(leader
, true);
3880 * Since we co-schedule groups, {enabled,running} times of siblings
3881 * will be identical to those of the leader, so we only publish one
3884 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3885 values
[n
++] += leader
->total_time_enabled
+
3886 atomic64_read(&leader
->child_total_time_enabled
);
3889 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3890 values
[n
++] += leader
->total_time_running
+
3891 atomic64_read(&leader
->child_total_time_running
);
3895 * Write {count,id} tuples for every sibling.
3897 values
[n
++] += perf_event_count(leader
);
3898 if (read_format
& PERF_FORMAT_ID
)
3899 values
[n
++] = primary_event_id(leader
);
3901 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3902 values
[n
++] += perf_event_count(sub
);
3903 if (read_format
& PERF_FORMAT_ID
)
3904 values
[n
++] = primary_event_id(sub
);
3910 static int perf_read_group(struct perf_event
*event
,
3911 u64 read_format
, char __user
*buf
)
3913 struct perf_event
*leader
= event
->group_leader
, *child
;
3914 struct perf_event_context
*ctx
= leader
->ctx
;
3918 lockdep_assert_held(&ctx
->mutex
);
3920 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
3924 values
[0] = 1 + leader
->nr_siblings
;
3927 * By locking the child_mutex of the leader we effectively
3928 * lock the child list of all siblings.. XXX explain how.
3930 mutex_lock(&leader
->child_mutex
);
3932 ret
= __perf_read_group_add(leader
, read_format
, values
);
3936 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
3937 ret
= __perf_read_group_add(child
, read_format
, values
);
3942 mutex_unlock(&leader
->child_mutex
);
3944 ret
= event
->read_size
;
3945 if (copy_to_user(buf
, values
, event
->read_size
))
3950 mutex_unlock(&leader
->child_mutex
);
3956 static int perf_read_one(struct perf_event
*event
,
3957 u64 read_format
, char __user
*buf
)
3959 u64 enabled
, running
;
3963 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3964 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3965 values
[n
++] = enabled
;
3966 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3967 values
[n
++] = running
;
3968 if (read_format
& PERF_FORMAT_ID
)
3969 values
[n
++] = primary_event_id(event
);
3971 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3974 return n
* sizeof(u64
);
3977 static bool is_event_hup(struct perf_event
*event
)
3981 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
3984 mutex_lock(&event
->child_mutex
);
3985 no_children
= list_empty(&event
->child_list
);
3986 mutex_unlock(&event
->child_mutex
);
3991 * Read the performance event - simple non blocking version for now
3994 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
3996 u64 read_format
= event
->attr
.read_format
;
4000 * Return end-of-file for a read on a event that is in
4001 * error state (i.e. because it was pinned but it couldn't be
4002 * scheduled on to the CPU at some point).
4004 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4007 if (count
< event
->read_size
)
4010 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4011 if (read_format
& PERF_FORMAT_GROUP
)
4012 ret
= perf_read_group(event
, read_format
, buf
);
4014 ret
= perf_read_one(event
, read_format
, buf
);
4020 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4022 struct perf_event
*event
= file
->private_data
;
4023 struct perf_event_context
*ctx
;
4026 ctx
= perf_event_ctx_lock(event
);
4027 ret
= __perf_read(event
, buf
, count
);
4028 perf_event_ctx_unlock(event
, ctx
);
4033 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4035 struct perf_event
*event
= file
->private_data
;
4036 struct ring_buffer
*rb
;
4037 unsigned int events
= POLLHUP
;
4039 poll_wait(file
, &event
->waitq
, wait
);
4041 if (is_event_hup(event
))
4045 * Pin the event->rb by taking event->mmap_mutex; otherwise
4046 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4048 mutex_lock(&event
->mmap_mutex
);
4051 events
= atomic_xchg(&rb
->poll
, 0);
4052 mutex_unlock(&event
->mmap_mutex
);
4056 static void _perf_event_reset(struct perf_event
*event
)
4058 (void)perf_event_read(event
, false);
4059 local64_set(&event
->count
, 0);
4060 perf_event_update_userpage(event
);
4064 * Holding the top-level event's child_mutex means that any
4065 * descendant process that has inherited this event will block
4066 * in sync_child_event if it goes to exit, thus satisfying the
4067 * task existence requirements of perf_event_enable/disable.
4069 static void perf_event_for_each_child(struct perf_event
*event
,
4070 void (*func
)(struct perf_event
*))
4072 struct perf_event
*child
;
4074 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4076 mutex_lock(&event
->child_mutex
);
4078 list_for_each_entry(child
, &event
->child_list
, child_list
)
4080 mutex_unlock(&event
->child_mutex
);
4083 static void perf_event_for_each(struct perf_event
*event
,
4084 void (*func
)(struct perf_event
*))
4086 struct perf_event_context
*ctx
= event
->ctx
;
4087 struct perf_event
*sibling
;
4089 lockdep_assert_held(&ctx
->mutex
);
4091 event
= event
->group_leader
;
4093 perf_event_for_each_child(event
, func
);
4094 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4095 perf_event_for_each_child(sibling
, func
);
4098 struct period_event
{
4099 struct perf_event
*event
;
4103 static void ___perf_event_period(void *info
)
4105 struct period_event
*pe
= info
;
4106 struct perf_event
*event
= pe
->event
;
4107 u64 value
= pe
->value
;
4109 if (event
->attr
.freq
) {
4110 event
->attr
.sample_freq
= value
;
4112 event
->attr
.sample_period
= value
;
4113 event
->hw
.sample_period
= value
;
4116 local64_set(&event
->hw
.period_left
, 0);
4119 static int __perf_event_period(void *info
)
4121 struct period_event
*pe
= info
;
4122 struct perf_event
*event
= pe
->event
;
4123 struct perf_event_context
*ctx
= event
->ctx
;
4124 u64 value
= pe
->value
;
4127 raw_spin_lock(&ctx
->lock
);
4128 if (event
->attr
.freq
) {
4129 event
->attr
.sample_freq
= value
;
4131 event
->attr
.sample_period
= value
;
4132 event
->hw
.sample_period
= value
;
4135 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4137 perf_pmu_disable(ctx
->pmu
);
4138 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4141 local64_set(&event
->hw
.period_left
, 0);
4144 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4145 perf_pmu_enable(ctx
->pmu
);
4147 raw_spin_unlock(&ctx
->lock
);
4152 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4154 struct period_event pe
= { .event
= event
, };
4157 if (!is_sampling_event(event
))
4160 if (copy_from_user(&value
, arg
, sizeof(value
)))
4166 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4171 event_function_call(event
, __perf_event_period
,
4172 ___perf_event_period
, &pe
);
4177 static const struct file_operations perf_fops
;
4179 static inline int perf_fget_light(int fd
, struct fd
*p
)
4181 struct fd f
= fdget(fd
);
4185 if (f
.file
->f_op
!= &perf_fops
) {
4193 static int perf_event_set_output(struct perf_event
*event
,
4194 struct perf_event
*output_event
);
4195 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4196 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4198 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4200 void (*func
)(struct perf_event
*);
4204 case PERF_EVENT_IOC_ENABLE
:
4205 func
= _perf_event_enable
;
4207 case PERF_EVENT_IOC_DISABLE
:
4208 func
= _perf_event_disable
;
4210 case PERF_EVENT_IOC_RESET
:
4211 func
= _perf_event_reset
;
4214 case PERF_EVENT_IOC_REFRESH
:
4215 return _perf_event_refresh(event
, arg
);
4217 case PERF_EVENT_IOC_PERIOD
:
4218 return perf_event_period(event
, (u64 __user
*)arg
);
4220 case PERF_EVENT_IOC_ID
:
4222 u64 id
= primary_event_id(event
);
4224 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4229 case PERF_EVENT_IOC_SET_OUTPUT
:
4233 struct perf_event
*output_event
;
4235 ret
= perf_fget_light(arg
, &output
);
4238 output_event
= output
.file
->private_data
;
4239 ret
= perf_event_set_output(event
, output_event
);
4242 ret
= perf_event_set_output(event
, NULL
);
4247 case PERF_EVENT_IOC_SET_FILTER
:
4248 return perf_event_set_filter(event
, (void __user
*)arg
);
4250 case PERF_EVENT_IOC_SET_BPF
:
4251 return perf_event_set_bpf_prog(event
, arg
);
4257 if (flags
& PERF_IOC_FLAG_GROUP
)
4258 perf_event_for_each(event
, func
);
4260 perf_event_for_each_child(event
, func
);
4265 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4267 struct perf_event
*event
= file
->private_data
;
4268 struct perf_event_context
*ctx
;
4271 ctx
= perf_event_ctx_lock(event
);
4272 ret
= _perf_ioctl(event
, cmd
, arg
);
4273 perf_event_ctx_unlock(event
, ctx
);
4278 #ifdef CONFIG_COMPAT
4279 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4282 switch (_IOC_NR(cmd
)) {
4283 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4284 case _IOC_NR(PERF_EVENT_IOC_ID
):
4285 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4286 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4287 cmd
&= ~IOCSIZE_MASK
;
4288 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4292 return perf_ioctl(file
, cmd
, arg
);
4295 # define perf_compat_ioctl NULL
4298 int perf_event_task_enable(void)
4300 struct perf_event_context
*ctx
;
4301 struct perf_event
*event
;
4303 mutex_lock(¤t
->perf_event_mutex
);
4304 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4305 ctx
= perf_event_ctx_lock(event
);
4306 perf_event_for_each_child(event
, _perf_event_enable
);
4307 perf_event_ctx_unlock(event
, ctx
);
4309 mutex_unlock(¤t
->perf_event_mutex
);
4314 int perf_event_task_disable(void)
4316 struct perf_event_context
*ctx
;
4317 struct perf_event
*event
;
4319 mutex_lock(¤t
->perf_event_mutex
);
4320 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4321 ctx
= perf_event_ctx_lock(event
);
4322 perf_event_for_each_child(event
, _perf_event_disable
);
4323 perf_event_ctx_unlock(event
, ctx
);
4325 mutex_unlock(¤t
->perf_event_mutex
);
4330 static int perf_event_index(struct perf_event
*event
)
4332 if (event
->hw
.state
& PERF_HES_STOPPED
)
4335 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4338 return event
->pmu
->event_idx(event
);
4341 static void calc_timer_values(struct perf_event
*event
,
4348 *now
= perf_clock();
4349 ctx_time
= event
->shadow_ctx_time
+ *now
;
4350 *enabled
= ctx_time
- event
->tstamp_enabled
;
4351 *running
= ctx_time
- event
->tstamp_running
;
4354 static void perf_event_init_userpage(struct perf_event
*event
)
4356 struct perf_event_mmap_page
*userpg
;
4357 struct ring_buffer
*rb
;
4360 rb
= rcu_dereference(event
->rb
);
4364 userpg
= rb
->user_page
;
4366 /* Allow new userspace to detect that bit 0 is deprecated */
4367 userpg
->cap_bit0_is_deprecated
= 1;
4368 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4369 userpg
->data_offset
= PAGE_SIZE
;
4370 userpg
->data_size
= perf_data_size(rb
);
4376 void __weak
arch_perf_update_userpage(
4377 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4382 * Callers need to ensure there can be no nesting of this function, otherwise
4383 * the seqlock logic goes bad. We can not serialize this because the arch
4384 * code calls this from NMI context.
4386 void perf_event_update_userpage(struct perf_event
*event
)
4388 struct perf_event_mmap_page
*userpg
;
4389 struct ring_buffer
*rb
;
4390 u64 enabled
, running
, now
;
4393 rb
= rcu_dereference(event
->rb
);
4398 * compute total_time_enabled, total_time_running
4399 * based on snapshot values taken when the event
4400 * was last scheduled in.
4402 * we cannot simply called update_context_time()
4403 * because of locking issue as we can be called in
4406 calc_timer_values(event
, &now
, &enabled
, &running
);
4408 userpg
= rb
->user_page
;
4410 * Disable preemption so as to not let the corresponding user-space
4411 * spin too long if we get preempted.
4416 userpg
->index
= perf_event_index(event
);
4417 userpg
->offset
= perf_event_count(event
);
4419 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4421 userpg
->time_enabled
= enabled
+
4422 atomic64_read(&event
->child_total_time_enabled
);
4424 userpg
->time_running
= running
+
4425 atomic64_read(&event
->child_total_time_running
);
4427 arch_perf_update_userpage(event
, userpg
, now
);
4436 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4438 struct perf_event
*event
= vma
->vm_file
->private_data
;
4439 struct ring_buffer
*rb
;
4440 int ret
= VM_FAULT_SIGBUS
;
4442 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4443 if (vmf
->pgoff
== 0)
4449 rb
= rcu_dereference(event
->rb
);
4453 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4456 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4460 get_page(vmf
->page
);
4461 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4462 vmf
->page
->index
= vmf
->pgoff
;
4471 static void ring_buffer_attach(struct perf_event
*event
,
4472 struct ring_buffer
*rb
)
4474 struct ring_buffer
*old_rb
= NULL
;
4475 unsigned long flags
;
4479 * Should be impossible, we set this when removing
4480 * event->rb_entry and wait/clear when adding event->rb_entry.
4482 WARN_ON_ONCE(event
->rcu_pending
);
4485 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4486 list_del_rcu(&event
->rb_entry
);
4487 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4489 event
->rcu_batches
= get_state_synchronize_rcu();
4490 event
->rcu_pending
= 1;
4494 if (event
->rcu_pending
) {
4495 cond_synchronize_rcu(event
->rcu_batches
);
4496 event
->rcu_pending
= 0;
4499 spin_lock_irqsave(&rb
->event_lock
, flags
);
4500 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4501 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4504 rcu_assign_pointer(event
->rb
, rb
);
4507 ring_buffer_put(old_rb
);
4509 * Since we detached before setting the new rb, so that we
4510 * could attach the new rb, we could have missed a wakeup.
4513 wake_up_all(&event
->waitq
);
4517 static void ring_buffer_wakeup(struct perf_event
*event
)
4519 struct ring_buffer
*rb
;
4522 rb
= rcu_dereference(event
->rb
);
4524 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4525 wake_up_all(&event
->waitq
);
4530 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4532 struct ring_buffer
*rb
;
4535 rb
= rcu_dereference(event
->rb
);
4537 if (!atomic_inc_not_zero(&rb
->refcount
))
4545 void ring_buffer_put(struct ring_buffer
*rb
)
4547 if (!atomic_dec_and_test(&rb
->refcount
))
4550 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4552 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4555 static void perf_mmap_open(struct vm_area_struct
*vma
)
4557 struct perf_event
*event
= vma
->vm_file
->private_data
;
4559 atomic_inc(&event
->mmap_count
);
4560 atomic_inc(&event
->rb
->mmap_count
);
4563 atomic_inc(&event
->rb
->aux_mmap_count
);
4565 if (event
->pmu
->event_mapped
)
4566 event
->pmu
->event_mapped(event
);
4570 * A buffer can be mmap()ed multiple times; either directly through the same
4571 * event, or through other events by use of perf_event_set_output().
4573 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4574 * the buffer here, where we still have a VM context. This means we need
4575 * to detach all events redirecting to us.
4577 static void perf_mmap_close(struct vm_area_struct
*vma
)
4579 struct perf_event
*event
= vma
->vm_file
->private_data
;
4581 struct ring_buffer
*rb
= ring_buffer_get(event
);
4582 struct user_struct
*mmap_user
= rb
->mmap_user
;
4583 int mmap_locked
= rb
->mmap_locked
;
4584 unsigned long size
= perf_data_size(rb
);
4586 if (event
->pmu
->event_unmapped
)
4587 event
->pmu
->event_unmapped(event
);
4590 * rb->aux_mmap_count will always drop before rb->mmap_count and
4591 * event->mmap_count, so it is ok to use event->mmap_mutex to
4592 * serialize with perf_mmap here.
4594 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4595 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4596 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4597 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4600 mutex_unlock(&event
->mmap_mutex
);
4603 atomic_dec(&rb
->mmap_count
);
4605 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4608 ring_buffer_attach(event
, NULL
);
4609 mutex_unlock(&event
->mmap_mutex
);
4611 /* If there's still other mmap()s of this buffer, we're done. */
4612 if (atomic_read(&rb
->mmap_count
))
4616 * No other mmap()s, detach from all other events that might redirect
4617 * into the now unreachable buffer. Somewhat complicated by the
4618 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4622 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4623 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4625 * This event is en-route to free_event() which will
4626 * detach it and remove it from the list.
4632 mutex_lock(&event
->mmap_mutex
);
4634 * Check we didn't race with perf_event_set_output() which can
4635 * swizzle the rb from under us while we were waiting to
4636 * acquire mmap_mutex.
4638 * If we find a different rb; ignore this event, a next
4639 * iteration will no longer find it on the list. We have to
4640 * still restart the iteration to make sure we're not now
4641 * iterating the wrong list.
4643 if (event
->rb
== rb
)
4644 ring_buffer_attach(event
, NULL
);
4646 mutex_unlock(&event
->mmap_mutex
);
4650 * Restart the iteration; either we're on the wrong list or
4651 * destroyed its integrity by doing a deletion.
4658 * It could be there's still a few 0-ref events on the list; they'll
4659 * get cleaned up by free_event() -- they'll also still have their
4660 * ref on the rb and will free it whenever they are done with it.
4662 * Aside from that, this buffer is 'fully' detached and unmapped,
4663 * undo the VM accounting.
4666 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4667 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4668 free_uid(mmap_user
);
4671 ring_buffer_put(rb
); /* could be last */
4674 static const struct vm_operations_struct perf_mmap_vmops
= {
4675 .open
= perf_mmap_open
,
4676 .close
= perf_mmap_close
, /* non mergable */
4677 .fault
= perf_mmap_fault
,
4678 .page_mkwrite
= perf_mmap_fault
,
4681 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4683 struct perf_event
*event
= file
->private_data
;
4684 unsigned long user_locked
, user_lock_limit
;
4685 struct user_struct
*user
= current_user();
4686 unsigned long locked
, lock_limit
;
4687 struct ring_buffer
*rb
= NULL
;
4688 unsigned long vma_size
;
4689 unsigned long nr_pages
;
4690 long user_extra
= 0, extra
= 0;
4691 int ret
= 0, flags
= 0;
4694 * Don't allow mmap() of inherited per-task counters. This would
4695 * create a performance issue due to all children writing to the
4698 if (event
->cpu
== -1 && event
->attr
.inherit
)
4701 if (!(vma
->vm_flags
& VM_SHARED
))
4704 vma_size
= vma
->vm_end
- vma
->vm_start
;
4706 if (vma
->vm_pgoff
== 0) {
4707 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4710 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4711 * mapped, all subsequent mappings should have the same size
4712 * and offset. Must be above the normal perf buffer.
4714 u64 aux_offset
, aux_size
;
4719 nr_pages
= vma_size
/ PAGE_SIZE
;
4721 mutex_lock(&event
->mmap_mutex
);
4728 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4729 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4731 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4734 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4737 /* already mapped with a different offset */
4738 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4741 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4744 /* already mapped with a different size */
4745 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4748 if (!is_power_of_2(nr_pages
))
4751 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4754 if (rb_has_aux(rb
)) {
4755 atomic_inc(&rb
->aux_mmap_count
);
4760 atomic_set(&rb
->aux_mmap_count
, 1);
4761 user_extra
= nr_pages
;
4767 * If we have rb pages ensure they're a power-of-two number, so we
4768 * can do bitmasks instead of modulo.
4770 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4773 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4776 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4778 mutex_lock(&event
->mmap_mutex
);
4780 if (event
->rb
->nr_pages
!= nr_pages
) {
4785 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4787 * Raced against perf_mmap_close() through
4788 * perf_event_set_output(). Try again, hope for better
4791 mutex_unlock(&event
->mmap_mutex
);
4798 user_extra
= nr_pages
+ 1;
4801 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4804 * Increase the limit linearly with more CPUs:
4806 user_lock_limit
*= num_online_cpus();
4808 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4810 if (user_locked
> user_lock_limit
)
4811 extra
= user_locked
- user_lock_limit
;
4813 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4814 lock_limit
>>= PAGE_SHIFT
;
4815 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4817 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4818 !capable(CAP_IPC_LOCK
)) {
4823 WARN_ON(!rb
&& event
->rb
);
4825 if (vma
->vm_flags
& VM_WRITE
)
4826 flags
|= RING_BUFFER_WRITABLE
;
4829 rb
= rb_alloc(nr_pages
,
4830 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4838 atomic_set(&rb
->mmap_count
, 1);
4839 rb
->mmap_user
= get_current_user();
4840 rb
->mmap_locked
= extra
;
4842 ring_buffer_attach(event
, rb
);
4844 perf_event_init_userpage(event
);
4845 perf_event_update_userpage(event
);
4847 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4848 event
->attr
.aux_watermark
, flags
);
4850 rb
->aux_mmap_locked
= extra
;
4855 atomic_long_add(user_extra
, &user
->locked_vm
);
4856 vma
->vm_mm
->pinned_vm
+= extra
;
4858 atomic_inc(&event
->mmap_count
);
4860 atomic_dec(&rb
->mmap_count
);
4863 mutex_unlock(&event
->mmap_mutex
);
4866 * Since pinned accounting is per vm we cannot allow fork() to copy our
4869 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4870 vma
->vm_ops
= &perf_mmap_vmops
;
4872 if (event
->pmu
->event_mapped
)
4873 event
->pmu
->event_mapped(event
);
4878 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4880 struct inode
*inode
= file_inode(filp
);
4881 struct perf_event
*event
= filp
->private_data
;
4884 mutex_lock(&inode
->i_mutex
);
4885 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4886 mutex_unlock(&inode
->i_mutex
);
4894 static const struct file_operations perf_fops
= {
4895 .llseek
= no_llseek
,
4896 .release
= perf_release
,
4899 .unlocked_ioctl
= perf_ioctl
,
4900 .compat_ioctl
= perf_compat_ioctl
,
4902 .fasync
= perf_fasync
,
4908 * If there's data, ensure we set the poll() state and publish everything
4909 * to user-space before waking everybody up.
4912 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
4914 /* only the parent has fasync state */
4916 event
= event
->parent
;
4917 return &event
->fasync
;
4920 void perf_event_wakeup(struct perf_event
*event
)
4922 ring_buffer_wakeup(event
);
4924 if (event
->pending_kill
) {
4925 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
4926 event
->pending_kill
= 0;
4930 static void perf_pending_event(struct irq_work
*entry
)
4932 struct perf_event
*event
= container_of(entry
,
4933 struct perf_event
, pending
);
4936 rctx
= perf_swevent_get_recursion_context();
4938 * If we 'fail' here, that's OK, it means recursion is already disabled
4939 * and we won't recurse 'further'.
4942 if (event
->pending_disable
) {
4943 event
->pending_disable
= 0;
4944 __perf_event_disable(event
);
4947 if (event
->pending_wakeup
) {
4948 event
->pending_wakeup
= 0;
4949 perf_event_wakeup(event
);
4953 perf_swevent_put_recursion_context(rctx
);
4957 * We assume there is only KVM supporting the callbacks.
4958 * Later on, we might change it to a list if there is
4959 * another virtualization implementation supporting the callbacks.
4961 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4963 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4965 perf_guest_cbs
= cbs
;
4968 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4970 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4972 perf_guest_cbs
= NULL
;
4975 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4978 perf_output_sample_regs(struct perf_output_handle
*handle
,
4979 struct pt_regs
*regs
, u64 mask
)
4983 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4984 sizeof(mask
) * BITS_PER_BYTE
) {
4987 val
= perf_reg_value(regs
, bit
);
4988 perf_output_put(handle
, val
);
4992 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
4993 struct pt_regs
*regs
,
4994 struct pt_regs
*regs_user_copy
)
4996 if (user_mode(regs
)) {
4997 regs_user
->abi
= perf_reg_abi(current
);
4998 regs_user
->regs
= regs
;
4999 } else if (current
->mm
) {
5000 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5002 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5003 regs_user
->regs
= NULL
;
5007 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5008 struct pt_regs
*regs
)
5010 regs_intr
->regs
= regs
;
5011 regs_intr
->abi
= perf_reg_abi(current
);
5016 * Get remaining task size from user stack pointer.
5018 * It'd be better to take stack vma map and limit this more
5019 * precisly, but there's no way to get it safely under interrupt,
5020 * so using TASK_SIZE as limit.
5022 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5024 unsigned long addr
= perf_user_stack_pointer(regs
);
5026 if (!addr
|| addr
>= TASK_SIZE
)
5029 return TASK_SIZE
- addr
;
5033 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5034 struct pt_regs
*regs
)
5038 /* No regs, no stack pointer, no dump. */
5043 * Check if we fit in with the requested stack size into the:
5045 * If we don't, we limit the size to the TASK_SIZE.
5047 * - remaining sample size
5048 * If we don't, we customize the stack size to
5049 * fit in to the remaining sample size.
5052 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5053 stack_size
= min(stack_size
, (u16
) task_size
);
5055 /* Current header size plus static size and dynamic size. */
5056 header_size
+= 2 * sizeof(u64
);
5058 /* Do we fit in with the current stack dump size? */
5059 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5061 * If we overflow the maximum size for the sample,
5062 * we customize the stack dump size to fit in.
5064 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5065 stack_size
= round_up(stack_size
, sizeof(u64
));
5072 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5073 struct pt_regs
*regs
)
5075 /* Case of a kernel thread, nothing to dump */
5078 perf_output_put(handle
, size
);
5087 * - the size requested by user or the best one we can fit
5088 * in to the sample max size
5090 * - user stack dump data
5092 * - the actual dumped size
5096 perf_output_put(handle
, dump_size
);
5099 sp
= perf_user_stack_pointer(regs
);
5100 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5101 dyn_size
= dump_size
- rem
;
5103 perf_output_skip(handle
, rem
);
5106 perf_output_put(handle
, dyn_size
);
5110 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5111 struct perf_sample_data
*data
,
5112 struct perf_event
*event
)
5114 u64 sample_type
= event
->attr
.sample_type
;
5116 data
->type
= sample_type
;
5117 header
->size
+= event
->id_header_size
;
5119 if (sample_type
& PERF_SAMPLE_TID
) {
5120 /* namespace issues */
5121 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5122 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5125 if (sample_type
& PERF_SAMPLE_TIME
)
5126 data
->time
= perf_event_clock(event
);
5128 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5129 data
->id
= primary_event_id(event
);
5131 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5132 data
->stream_id
= event
->id
;
5134 if (sample_type
& PERF_SAMPLE_CPU
) {
5135 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5136 data
->cpu_entry
.reserved
= 0;
5140 void perf_event_header__init_id(struct perf_event_header
*header
,
5141 struct perf_sample_data
*data
,
5142 struct perf_event
*event
)
5144 if (event
->attr
.sample_id_all
)
5145 __perf_event_header__init_id(header
, data
, event
);
5148 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5149 struct perf_sample_data
*data
)
5151 u64 sample_type
= data
->type
;
5153 if (sample_type
& PERF_SAMPLE_TID
)
5154 perf_output_put(handle
, data
->tid_entry
);
5156 if (sample_type
& PERF_SAMPLE_TIME
)
5157 perf_output_put(handle
, data
->time
);
5159 if (sample_type
& PERF_SAMPLE_ID
)
5160 perf_output_put(handle
, data
->id
);
5162 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5163 perf_output_put(handle
, data
->stream_id
);
5165 if (sample_type
& PERF_SAMPLE_CPU
)
5166 perf_output_put(handle
, data
->cpu_entry
);
5168 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5169 perf_output_put(handle
, data
->id
);
5172 void perf_event__output_id_sample(struct perf_event
*event
,
5173 struct perf_output_handle
*handle
,
5174 struct perf_sample_data
*sample
)
5176 if (event
->attr
.sample_id_all
)
5177 __perf_event__output_id_sample(handle
, sample
);
5180 static void perf_output_read_one(struct perf_output_handle
*handle
,
5181 struct perf_event
*event
,
5182 u64 enabled
, u64 running
)
5184 u64 read_format
= event
->attr
.read_format
;
5188 values
[n
++] = perf_event_count(event
);
5189 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5190 values
[n
++] = enabled
+
5191 atomic64_read(&event
->child_total_time_enabled
);
5193 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5194 values
[n
++] = running
+
5195 atomic64_read(&event
->child_total_time_running
);
5197 if (read_format
& PERF_FORMAT_ID
)
5198 values
[n
++] = primary_event_id(event
);
5200 __output_copy(handle
, values
, n
* sizeof(u64
));
5204 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5206 static void perf_output_read_group(struct perf_output_handle
*handle
,
5207 struct perf_event
*event
,
5208 u64 enabled
, u64 running
)
5210 struct perf_event
*leader
= event
->group_leader
, *sub
;
5211 u64 read_format
= event
->attr
.read_format
;
5215 values
[n
++] = 1 + leader
->nr_siblings
;
5217 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5218 values
[n
++] = enabled
;
5220 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5221 values
[n
++] = running
;
5223 if (leader
!= event
)
5224 leader
->pmu
->read(leader
);
5226 values
[n
++] = perf_event_count(leader
);
5227 if (read_format
& PERF_FORMAT_ID
)
5228 values
[n
++] = primary_event_id(leader
);
5230 __output_copy(handle
, values
, n
* sizeof(u64
));
5232 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5235 if ((sub
!= event
) &&
5236 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5237 sub
->pmu
->read(sub
);
5239 values
[n
++] = perf_event_count(sub
);
5240 if (read_format
& PERF_FORMAT_ID
)
5241 values
[n
++] = primary_event_id(sub
);
5243 __output_copy(handle
, values
, n
* sizeof(u64
));
5247 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5248 PERF_FORMAT_TOTAL_TIME_RUNNING)
5250 static void perf_output_read(struct perf_output_handle
*handle
,
5251 struct perf_event
*event
)
5253 u64 enabled
= 0, running
= 0, now
;
5254 u64 read_format
= event
->attr
.read_format
;
5257 * compute total_time_enabled, total_time_running
5258 * based on snapshot values taken when the event
5259 * was last scheduled in.
5261 * we cannot simply called update_context_time()
5262 * because of locking issue as we are called in
5265 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5266 calc_timer_values(event
, &now
, &enabled
, &running
);
5268 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5269 perf_output_read_group(handle
, event
, enabled
, running
);
5271 perf_output_read_one(handle
, event
, enabled
, running
);
5274 void perf_output_sample(struct perf_output_handle
*handle
,
5275 struct perf_event_header
*header
,
5276 struct perf_sample_data
*data
,
5277 struct perf_event
*event
)
5279 u64 sample_type
= data
->type
;
5281 perf_output_put(handle
, *header
);
5283 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5284 perf_output_put(handle
, data
->id
);
5286 if (sample_type
& PERF_SAMPLE_IP
)
5287 perf_output_put(handle
, data
->ip
);
5289 if (sample_type
& PERF_SAMPLE_TID
)
5290 perf_output_put(handle
, data
->tid_entry
);
5292 if (sample_type
& PERF_SAMPLE_TIME
)
5293 perf_output_put(handle
, data
->time
);
5295 if (sample_type
& PERF_SAMPLE_ADDR
)
5296 perf_output_put(handle
, data
->addr
);
5298 if (sample_type
& PERF_SAMPLE_ID
)
5299 perf_output_put(handle
, data
->id
);
5301 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5302 perf_output_put(handle
, data
->stream_id
);
5304 if (sample_type
& PERF_SAMPLE_CPU
)
5305 perf_output_put(handle
, data
->cpu_entry
);
5307 if (sample_type
& PERF_SAMPLE_PERIOD
)
5308 perf_output_put(handle
, data
->period
);
5310 if (sample_type
& PERF_SAMPLE_READ
)
5311 perf_output_read(handle
, event
);
5313 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5314 if (data
->callchain
) {
5317 if (data
->callchain
)
5318 size
+= data
->callchain
->nr
;
5320 size
*= sizeof(u64
);
5322 __output_copy(handle
, data
->callchain
, size
);
5325 perf_output_put(handle
, nr
);
5329 if (sample_type
& PERF_SAMPLE_RAW
) {
5331 u32 raw_size
= data
->raw
->size
;
5332 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5333 sizeof(u64
)) - sizeof(u32
);
5336 perf_output_put(handle
, real_size
);
5337 __output_copy(handle
, data
->raw
->data
, raw_size
);
5338 if (real_size
- raw_size
)
5339 __output_copy(handle
, &zero
, real_size
- raw_size
);
5345 .size
= sizeof(u32
),
5348 perf_output_put(handle
, raw
);
5352 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5353 if (data
->br_stack
) {
5356 size
= data
->br_stack
->nr
5357 * sizeof(struct perf_branch_entry
);
5359 perf_output_put(handle
, data
->br_stack
->nr
);
5360 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5363 * we always store at least the value of nr
5366 perf_output_put(handle
, nr
);
5370 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5371 u64 abi
= data
->regs_user
.abi
;
5374 * If there are no regs to dump, notice it through
5375 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5377 perf_output_put(handle
, abi
);
5380 u64 mask
= event
->attr
.sample_regs_user
;
5381 perf_output_sample_regs(handle
,
5382 data
->regs_user
.regs
,
5387 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5388 perf_output_sample_ustack(handle
,
5389 data
->stack_user_size
,
5390 data
->regs_user
.regs
);
5393 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5394 perf_output_put(handle
, data
->weight
);
5396 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5397 perf_output_put(handle
, data
->data_src
.val
);
5399 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5400 perf_output_put(handle
, data
->txn
);
5402 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5403 u64 abi
= data
->regs_intr
.abi
;
5405 * If there are no regs to dump, notice it through
5406 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5408 perf_output_put(handle
, abi
);
5411 u64 mask
= event
->attr
.sample_regs_intr
;
5413 perf_output_sample_regs(handle
,
5414 data
->regs_intr
.regs
,
5419 if (!event
->attr
.watermark
) {
5420 int wakeup_events
= event
->attr
.wakeup_events
;
5422 if (wakeup_events
) {
5423 struct ring_buffer
*rb
= handle
->rb
;
5424 int events
= local_inc_return(&rb
->events
);
5426 if (events
>= wakeup_events
) {
5427 local_sub(wakeup_events
, &rb
->events
);
5428 local_inc(&rb
->wakeup
);
5434 void perf_prepare_sample(struct perf_event_header
*header
,
5435 struct perf_sample_data
*data
,
5436 struct perf_event
*event
,
5437 struct pt_regs
*regs
)
5439 u64 sample_type
= event
->attr
.sample_type
;
5441 header
->type
= PERF_RECORD_SAMPLE
;
5442 header
->size
= sizeof(*header
) + event
->header_size
;
5445 header
->misc
|= perf_misc_flags(regs
);
5447 __perf_event_header__init_id(header
, data
, event
);
5449 if (sample_type
& PERF_SAMPLE_IP
)
5450 data
->ip
= perf_instruction_pointer(regs
);
5452 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5455 data
->callchain
= perf_callchain(event
, regs
);
5457 if (data
->callchain
)
5458 size
+= data
->callchain
->nr
;
5460 header
->size
+= size
* sizeof(u64
);
5463 if (sample_type
& PERF_SAMPLE_RAW
) {
5464 int size
= sizeof(u32
);
5467 size
+= data
->raw
->size
;
5469 size
+= sizeof(u32
);
5471 header
->size
+= round_up(size
, sizeof(u64
));
5474 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5475 int size
= sizeof(u64
); /* nr */
5476 if (data
->br_stack
) {
5477 size
+= data
->br_stack
->nr
5478 * sizeof(struct perf_branch_entry
);
5480 header
->size
+= size
;
5483 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5484 perf_sample_regs_user(&data
->regs_user
, regs
,
5485 &data
->regs_user_copy
);
5487 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5488 /* regs dump ABI info */
5489 int size
= sizeof(u64
);
5491 if (data
->regs_user
.regs
) {
5492 u64 mask
= event
->attr
.sample_regs_user
;
5493 size
+= hweight64(mask
) * sizeof(u64
);
5496 header
->size
+= size
;
5499 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5501 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5502 * processed as the last one or have additional check added
5503 * in case new sample type is added, because we could eat
5504 * up the rest of the sample size.
5506 u16 stack_size
= event
->attr
.sample_stack_user
;
5507 u16 size
= sizeof(u64
);
5509 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5510 data
->regs_user
.regs
);
5513 * If there is something to dump, add space for the dump
5514 * itself and for the field that tells the dynamic size,
5515 * which is how many have been actually dumped.
5518 size
+= sizeof(u64
) + stack_size
;
5520 data
->stack_user_size
= stack_size
;
5521 header
->size
+= size
;
5524 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5525 /* regs dump ABI info */
5526 int size
= sizeof(u64
);
5528 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5530 if (data
->regs_intr
.regs
) {
5531 u64 mask
= event
->attr
.sample_regs_intr
;
5533 size
+= hweight64(mask
) * sizeof(u64
);
5536 header
->size
+= size
;
5540 void perf_event_output(struct perf_event
*event
,
5541 struct perf_sample_data
*data
,
5542 struct pt_regs
*regs
)
5544 struct perf_output_handle handle
;
5545 struct perf_event_header header
;
5547 /* protect the callchain buffers */
5550 perf_prepare_sample(&header
, data
, event
, regs
);
5552 if (perf_output_begin(&handle
, event
, header
.size
))
5555 perf_output_sample(&handle
, &header
, data
, event
);
5557 perf_output_end(&handle
);
5567 struct perf_read_event
{
5568 struct perf_event_header header
;
5575 perf_event_read_event(struct perf_event
*event
,
5576 struct task_struct
*task
)
5578 struct perf_output_handle handle
;
5579 struct perf_sample_data sample
;
5580 struct perf_read_event read_event
= {
5582 .type
= PERF_RECORD_READ
,
5584 .size
= sizeof(read_event
) + event
->read_size
,
5586 .pid
= perf_event_pid(event
, task
),
5587 .tid
= perf_event_tid(event
, task
),
5591 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5592 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5596 perf_output_put(&handle
, read_event
);
5597 perf_output_read(&handle
, event
);
5598 perf_event__output_id_sample(event
, &handle
, &sample
);
5600 perf_output_end(&handle
);
5603 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5606 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5607 perf_event_aux_output_cb output
,
5610 struct perf_event
*event
;
5612 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5613 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5615 if (!event_filter_match(event
))
5617 output(event
, data
);
5622 perf_event_aux_task_ctx(perf_event_aux_output_cb output
, void *data
,
5623 struct perf_event_context
*task_ctx
)
5627 perf_event_aux_ctx(task_ctx
, output
, data
);
5633 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5634 struct perf_event_context
*task_ctx
)
5636 struct perf_cpu_context
*cpuctx
;
5637 struct perf_event_context
*ctx
;
5642 * If we have task_ctx != NULL we only notify
5643 * the task context itself. The task_ctx is set
5644 * only for EXIT events before releasing task
5648 perf_event_aux_task_ctx(output
, data
, task_ctx
);
5653 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5654 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5655 if (cpuctx
->unique_pmu
!= pmu
)
5657 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5658 ctxn
= pmu
->task_ctx_nr
;
5661 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5663 perf_event_aux_ctx(ctx
, output
, data
);
5665 put_cpu_ptr(pmu
->pmu_cpu_context
);
5671 * task tracking -- fork/exit
5673 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5676 struct perf_task_event
{
5677 struct task_struct
*task
;
5678 struct perf_event_context
*task_ctx
;
5681 struct perf_event_header header
;
5691 static int perf_event_task_match(struct perf_event
*event
)
5693 return event
->attr
.comm
|| event
->attr
.mmap
||
5694 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5698 static void perf_event_task_output(struct perf_event
*event
,
5701 struct perf_task_event
*task_event
= data
;
5702 struct perf_output_handle handle
;
5703 struct perf_sample_data sample
;
5704 struct task_struct
*task
= task_event
->task
;
5705 int ret
, size
= task_event
->event_id
.header
.size
;
5707 if (!perf_event_task_match(event
))
5710 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5712 ret
= perf_output_begin(&handle
, event
,
5713 task_event
->event_id
.header
.size
);
5717 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5718 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5720 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5721 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5723 task_event
->event_id
.time
= perf_event_clock(event
);
5725 perf_output_put(&handle
, task_event
->event_id
);
5727 perf_event__output_id_sample(event
, &handle
, &sample
);
5729 perf_output_end(&handle
);
5731 task_event
->event_id
.header
.size
= size
;
5734 static void perf_event_task(struct task_struct
*task
,
5735 struct perf_event_context
*task_ctx
,
5738 struct perf_task_event task_event
;
5740 if (!atomic_read(&nr_comm_events
) &&
5741 !atomic_read(&nr_mmap_events
) &&
5742 !atomic_read(&nr_task_events
))
5745 task_event
= (struct perf_task_event
){
5747 .task_ctx
= task_ctx
,
5750 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5752 .size
= sizeof(task_event
.event_id
),
5762 perf_event_aux(perf_event_task_output
,
5767 void perf_event_fork(struct task_struct
*task
)
5769 perf_event_task(task
, NULL
, 1);
5776 struct perf_comm_event
{
5777 struct task_struct
*task
;
5782 struct perf_event_header header
;
5789 static int perf_event_comm_match(struct perf_event
*event
)
5791 return event
->attr
.comm
;
5794 static void perf_event_comm_output(struct perf_event
*event
,
5797 struct perf_comm_event
*comm_event
= data
;
5798 struct perf_output_handle handle
;
5799 struct perf_sample_data sample
;
5800 int size
= comm_event
->event_id
.header
.size
;
5803 if (!perf_event_comm_match(event
))
5806 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5807 ret
= perf_output_begin(&handle
, event
,
5808 comm_event
->event_id
.header
.size
);
5813 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5814 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5816 perf_output_put(&handle
, comm_event
->event_id
);
5817 __output_copy(&handle
, comm_event
->comm
,
5818 comm_event
->comm_size
);
5820 perf_event__output_id_sample(event
, &handle
, &sample
);
5822 perf_output_end(&handle
);
5824 comm_event
->event_id
.header
.size
= size
;
5827 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5829 char comm
[TASK_COMM_LEN
];
5832 memset(comm
, 0, sizeof(comm
));
5833 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5834 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5836 comm_event
->comm
= comm
;
5837 comm_event
->comm_size
= size
;
5839 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5841 perf_event_aux(perf_event_comm_output
,
5846 void perf_event_comm(struct task_struct
*task
, bool exec
)
5848 struct perf_comm_event comm_event
;
5850 if (!atomic_read(&nr_comm_events
))
5853 comm_event
= (struct perf_comm_event
){
5859 .type
= PERF_RECORD_COMM
,
5860 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5868 perf_event_comm_event(&comm_event
);
5875 struct perf_mmap_event
{
5876 struct vm_area_struct
*vma
;
5878 const char *file_name
;
5886 struct perf_event_header header
;
5896 static int perf_event_mmap_match(struct perf_event
*event
,
5899 struct perf_mmap_event
*mmap_event
= data
;
5900 struct vm_area_struct
*vma
= mmap_event
->vma
;
5901 int executable
= vma
->vm_flags
& VM_EXEC
;
5903 return (!executable
&& event
->attr
.mmap_data
) ||
5904 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5907 static void perf_event_mmap_output(struct perf_event
*event
,
5910 struct perf_mmap_event
*mmap_event
= data
;
5911 struct perf_output_handle handle
;
5912 struct perf_sample_data sample
;
5913 int size
= mmap_event
->event_id
.header
.size
;
5916 if (!perf_event_mmap_match(event
, data
))
5919 if (event
->attr
.mmap2
) {
5920 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5921 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5922 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5923 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5924 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5925 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5926 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5929 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5930 ret
= perf_output_begin(&handle
, event
,
5931 mmap_event
->event_id
.header
.size
);
5935 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5936 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5938 perf_output_put(&handle
, mmap_event
->event_id
);
5940 if (event
->attr
.mmap2
) {
5941 perf_output_put(&handle
, mmap_event
->maj
);
5942 perf_output_put(&handle
, mmap_event
->min
);
5943 perf_output_put(&handle
, mmap_event
->ino
);
5944 perf_output_put(&handle
, mmap_event
->ino_generation
);
5945 perf_output_put(&handle
, mmap_event
->prot
);
5946 perf_output_put(&handle
, mmap_event
->flags
);
5949 __output_copy(&handle
, mmap_event
->file_name
,
5950 mmap_event
->file_size
);
5952 perf_event__output_id_sample(event
, &handle
, &sample
);
5954 perf_output_end(&handle
);
5956 mmap_event
->event_id
.header
.size
= size
;
5959 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5961 struct vm_area_struct
*vma
= mmap_event
->vma
;
5962 struct file
*file
= vma
->vm_file
;
5963 int maj
= 0, min
= 0;
5964 u64 ino
= 0, gen
= 0;
5965 u32 prot
= 0, flags
= 0;
5972 struct inode
*inode
;
5975 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5981 * d_path() works from the end of the rb backwards, so we
5982 * need to add enough zero bytes after the string to handle
5983 * the 64bit alignment we do later.
5985 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
5990 inode
= file_inode(vma
->vm_file
);
5991 dev
= inode
->i_sb
->s_dev
;
5993 gen
= inode
->i_generation
;
5997 if (vma
->vm_flags
& VM_READ
)
5999 if (vma
->vm_flags
& VM_WRITE
)
6001 if (vma
->vm_flags
& VM_EXEC
)
6004 if (vma
->vm_flags
& VM_MAYSHARE
)
6007 flags
= MAP_PRIVATE
;
6009 if (vma
->vm_flags
& VM_DENYWRITE
)
6010 flags
|= MAP_DENYWRITE
;
6011 if (vma
->vm_flags
& VM_MAYEXEC
)
6012 flags
|= MAP_EXECUTABLE
;
6013 if (vma
->vm_flags
& VM_LOCKED
)
6014 flags
|= MAP_LOCKED
;
6015 if (vma
->vm_flags
& VM_HUGETLB
)
6016 flags
|= MAP_HUGETLB
;
6020 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6021 name
= (char *) vma
->vm_ops
->name(vma
);
6026 name
= (char *)arch_vma_name(vma
);
6030 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6031 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6035 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6036 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6046 strlcpy(tmp
, name
, sizeof(tmp
));
6050 * Since our buffer works in 8 byte units we need to align our string
6051 * size to a multiple of 8. However, we must guarantee the tail end is
6052 * zero'd out to avoid leaking random bits to userspace.
6054 size
= strlen(name
)+1;
6055 while (!IS_ALIGNED(size
, sizeof(u64
)))
6056 name
[size
++] = '\0';
6058 mmap_event
->file_name
= name
;
6059 mmap_event
->file_size
= size
;
6060 mmap_event
->maj
= maj
;
6061 mmap_event
->min
= min
;
6062 mmap_event
->ino
= ino
;
6063 mmap_event
->ino_generation
= gen
;
6064 mmap_event
->prot
= prot
;
6065 mmap_event
->flags
= flags
;
6067 if (!(vma
->vm_flags
& VM_EXEC
))
6068 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6070 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6072 perf_event_aux(perf_event_mmap_output
,
6079 void perf_event_mmap(struct vm_area_struct
*vma
)
6081 struct perf_mmap_event mmap_event
;
6083 if (!atomic_read(&nr_mmap_events
))
6086 mmap_event
= (struct perf_mmap_event
){
6092 .type
= PERF_RECORD_MMAP
,
6093 .misc
= PERF_RECORD_MISC_USER
,
6098 .start
= vma
->vm_start
,
6099 .len
= vma
->vm_end
- vma
->vm_start
,
6100 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6102 /* .maj (attr_mmap2 only) */
6103 /* .min (attr_mmap2 only) */
6104 /* .ino (attr_mmap2 only) */
6105 /* .ino_generation (attr_mmap2 only) */
6106 /* .prot (attr_mmap2 only) */
6107 /* .flags (attr_mmap2 only) */
6110 perf_event_mmap_event(&mmap_event
);
6113 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6114 unsigned long size
, u64 flags
)
6116 struct perf_output_handle handle
;
6117 struct perf_sample_data sample
;
6118 struct perf_aux_event
{
6119 struct perf_event_header header
;
6125 .type
= PERF_RECORD_AUX
,
6127 .size
= sizeof(rec
),
6135 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6136 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6141 perf_output_put(&handle
, rec
);
6142 perf_event__output_id_sample(event
, &handle
, &sample
);
6144 perf_output_end(&handle
);
6148 * Lost/dropped samples logging
6150 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6152 struct perf_output_handle handle
;
6153 struct perf_sample_data sample
;
6157 struct perf_event_header header
;
6159 } lost_samples_event
= {
6161 .type
= PERF_RECORD_LOST_SAMPLES
,
6163 .size
= sizeof(lost_samples_event
),
6168 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6170 ret
= perf_output_begin(&handle
, event
,
6171 lost_samples_event
.header
.size
);
6175 perf_output_put(&handle
, lost_samples_event
);
6176 perf_event__output_id_sample(event
, &handle
, &sample
);
6177 perf_output_end(&handle
);
6181 * context_switch tracking
6184 struct perf_switch_event
{
6185 struct task_struct
*task
;
6186 struct task_struct
*next_prev
;
6189 struct perf_event_header header
;
6195 static int perf_event_switch_match(struct perf_event
*event
)
6197 return event
->attr
.context_switch
;
6200 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6202 struct perf_switch_event
*se
= data
;
6203 struct perf_output_handle handle
;
6204 struct perf_sample_data sample
;
6207 if (!perf_event_switch_match(event
))
6210 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6211 if (event
->ctx
->task
) {
6212 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6213 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6215 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6216 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6217 se
->event_id
.next_prev_pid
=
6218 perf_event_pid(event
, se
->next_prev
);
6219 se
->event_id
.next_prev_tid
=
6220 perf_event_tid(event
, se
->next_prev
);
6223 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6225 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6229 if (event
->ctx
->task
)
6230 perf_output_put(&handle
, se
->event_id
.header
);
6232 perf_output_put(&handle
, se
->event_id
);
6234 perf_event__output_id_sample(event
, &handle
, &sample
);
6236 perf_output_end(&handle
);
6239 static void perf_event_switch(struct task_struct
*task
,
6240 struct task_struct
*next_prev
, bool sched_in
)
6242 struct perf_switch_event switch_event
;
6244 /* N.B. caller checks nr_switch_events != 0 */
6246 switch_event
= (struct perf_switch_event
){
6248 .next_prev
= next_prev
,
6252 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6255 /* .next_prev_pid */
6256 /* .next_prev_tid */
6260 perf_event_aux(perf_event_switch_output
,
6266 * IRQ throttle logging
6269 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6271 struct perf_output_handle handle
;
6272 struct perf_sample_data sample
;
6276 struct perf_event_header header
;
6280 } throttle_event
= {
6282 .type
= PERF_RECORD_THROTTLE
,
6284 .size
= sizeof(throttle_event
),
6286 .time
= perf_event_clock(event
),
6287 .id
= primary_event_id(event
),
6288 .stream_id
= event
->id
,
6292 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6294 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6296 ret
= perf_output_begin(&handle
, event
,
6297 throttle_event
.header
.size
);
6301 perf_output_put(&handle
, throttle_event
);
6302 perf_event__output_id_sample(event
, &handle
, &sample
);
6303 perf_output_end(&handle
);
6306 static void perf_log_itrace_start(struct perf_event
*event
)
6308 struct perf_output_handle handle
;
6309 struct perf_sample_data sample
;
6310 struct perf_aux_event
{
6311 struct perf_event_header header
;
6318 event
= event
->parent
;
6320 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6321 event
->hw
.itrace_started
)
6324 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6325 rec
.header
.misc
= 0;
6326 rec
.header
.size
= sizeof(rec
);
6327 rec
.pid
= perf_event_pid(event
, current
);
6328 rec
.tid
= perf_event_tid(event
, current
);
6330 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6331 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6336 perf_output_put(&handle
, rec
);
6337 perf_event__output_id_sample(event
, &handle
, &sample
);
6339 perf_output_end(&handle
);
6343 * Generic event overflow handling, sampling.
6346 static int __perf_event_overflow(struct perf_event
*event
,
6347 int throttle
, struct perf_sample_data
*data
,
6348 struct pt_regs
*regs
)
6350 int events
= atomic_read(&event
->event_limit
);
6351 struct hw_perf_event
*hwc
= &event
->hw
;
6356 * Non-sampling counters might still use the PMI to fold short
6357 * hardware counters, ignore those.
6359 if (unlikely(!is_sampling_event(event
)))
6362 seq
= __this_cpu_read(perf_throttled_seq
);
6363 if (seq
!= hwc
->interrupts_seq
) {
6364 hwc
->interrupts_seq
= seq
;
6365 hwc
->interrupts
= 1;
6368 if (unlikely(throttle
6369 && hwc
->interrupts
>= max_samples_per_tick
)) {
6370 __this_cpu_inc(perf_throttled_count
);
6371 hwc
->interrupts
= MAX_INTERRUPTS
;
6372 perf_log_throttle(event
, 0);
6373 tick_nohz_full_kick();
6378 if (event
->attr
.freq
) {
6379 u64 now
= perf_clock();
6380 s64 delta
= now
- hwc
->freq_time_stamp
;
6382 hwc
->freq_time_stamp
= now
;
6384 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6385 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6389 * XXX event_limit might not quite work as expected on inherited
6393 event
->pending_kill
= POLL_IN
;
6394 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6396 event
->pending_kill
= POLL_HUP
;
6397 event
->pending_disable
= 1;
6398 irq_work_queue(&event
->pending
);
6401 if (event
->overflow_handler
)
6402 event
->overflow_handler(event
, data
, regs
);
6404 perf_event_output(event
, data
, regs
);
6406 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6407 event
->pending_wakeup
= 1;
6408 irq_work_queue(&event
->pending
);
6414 int perf_event_overflow(struct perf_event
*event
,
6415 struct perf_sample_data
*data
,
6416 struct pt_regs
*regs
)
6418 return __perf_event_overflow(event
, 1, data
, regs
);
6422 * Generic software event infrastructure
6425 struct swevent_htable
{
6426 struct swevent_hlist
*swevent_hlist
;
6427 struct mutex hlist_mutex
;
6430 /* Recursion avoidance in each contexts */
6431 int recursion
[PERF_NR_CONTEXTS
];
6434 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6437 * We directly increment event->count and keep a second value in
6438 * event->hw.period_left to count intervals. This period event
6439 * is kept in the range [-sample_period, 0] so that we can use the
6443 u64
perf_swevent_set_period(struct perf_event
*event
)
6445 struct hw_perf_event
*hwc
= &event
->hw
;
6446 u64 period
= hwc
->last_period
;
6450 hwc
->last_period
= hwc
->sample_period
;
6453 old
= val
= local64_read(&hwc
->period_left
);
6457 nr
= div64_u64(period
+ val
, period
);
6458 offset
= nr
* period
;
6460 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6466 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6467 struct perf_sample_data
*data
,
6468 struct pt_regs
*regs
)
6470 struct hw_perf_event
*hwc
= &event
->hw
;
6474 overflow
= perf_swevent_set_period(event
);
6476 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6479 for (; overflow
; overflow
--) {
6480 if (__perf_event_overflow(event
, throttle
,
6483 * We inhibit the overflow from happening when
6484 * hwc->interrupts == MAX_INTERRUPTS.
6492 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6493 struct perf_sample_data
*data
,
6494 struct pt_regs
*regs
)
6496 struct hw_perf_event
*hwc
= &event
->hw
;
6498 local64_add(nr
, &event
->count
);
6503 if (!is_sampling_event(event
))
6506 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6508 return perf_swevent_overflow(event
, 1, data
, regs
);
6510 data
->period
= event
->hw
.last_period
;
6512 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6513 return perf_swevent_overflow(event
, 1, data
, regs
);
6515 if (local64_add_negative(nr
, &hwc
->period_left
))
6518 perf_swevent_overflow(event
, 0, data
, regs
);
6521 static int perf_exclude_event(struct perf_event
*event
,
6522 struct pt_regs
*regs
)
6524 if (event
->hw
.state
& PERF_HES_STOPPED
)
6528 if (event
->attr
.exclude_user
&& user_mode(regs
))
6531 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6538 static int perf_swevent_match(struct perf_event
*event
,
6539 enum perf_type_id type
,
6541 struct perf_sample_data
*data
,
6542 struct pt_regs
*regs
)
6544 if (event
->attr
.type
!= type
)
6547 if (event
->attr
.config
!= event_id
)
6550 if (perf_exclude_event(event
, regs
))
6556 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6558 u64 val
= event_id
| (type
<< 32);
6560 return hash_64(val
, SWEVENT_HLIST_BITS
);
6563 static inline struct hlist_head
*
6564 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6566 u64 hash
= swevent_hash(type
, event_id
);
6568 return &hlist
->heads
[hash
];
6571 /* For the read side: events when they trigger */
6572 static inline struct hlist_head
*
6573 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6575 struct swevent_hlist
*hlist
;
6577 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6581 return __find_swevent_head(hlist
, type
, event_id
);
6584 /* For the event head insertion and removal in the hlist */
6585 static inline struct hlist_head
*
6586 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6588 struct swevent_hlist
*hlist
;
6589 u32 event_id
= event
->attr
.config
;
6590 u64 type
= event
->attr
.type
;
6593 * Event scheduling is always serialized against hlist allocation
6594 * and release. Which makes the protected version suitable here.
6595 * The context lock guarantees that.
6597 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6598 lockdep_is_held(&event
->ctx
->lock
));
6602 return __find_swevent_head(hlist
, type
, event_id
);
6605 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6607 struct perf_sample_data
*data
,
6608 struct pt_regs
*regs
)
6610 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6611 struct perf_event
*event
;
6612 struct hlist_head
*head
;
6615 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6619 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6620 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6621 perf_swevent_event(event
, nr
, data
, regs
);
6627 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6629 int perf_swevent_get_recursion_context(void)
6631 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6633 return get_recursion_context(swhash
->recursion
);
6635 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6637 inline void perf_swevent_put_recursion_context(int rctx
)
6639 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6641 put_recursion_context(swhash
->recursion
, rctx
);
6644 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6646 struct perf_sample_data data
;
6648 if (WARN_ON_ONCE(!regs
))
6651 perf_sample_data_init(&data
, addr
, 0);
6652 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6655 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6659 preempt_disable_notrace();
6660 rctx
= perf_swevent_get_recursion_context();
6661 if (unlikely(rctx
< 0))
6664 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6666 perf_swevent_put_recursion_context(rctx
);
6668 preempt_enable_notrace();
6671 static void perf_swevent_read(struct perf_event
*event
)
6675 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6677 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6678 struct hw_perf_event
*hwc
= &event
->hw
;
6679 struct hlist_head
*head
;
6681 if (is_sampling_event(event
)) {
6682 hwc
->last_period
= hwc
->sample_period
;
6683 perf_swevent_set_period(event
);
6686 hwc
->state
= !(flags
& PERF_EF_START
);
6688 head
= find_swevent_head(swhash
, event
);
6689 if (WARN_ON_ONCE(!head
))
6692 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6693 perf_event_update_userpage(event
);
6698 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6700 hlist_del_rcu(&event
->hlist_entry
);
6703 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6705 event
->hw
.state
= 0;
6708 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6710 event
->hw
.state
= PERF_HES_STOPPED
;
6713 /* Deref the hlist from the update side */
6714 static inline struct swevent_hlist
*
6715 swevent_hlist_deref(struct swevent_htable
*swhash
)
6717 return rcu_dereference_protected(swhash
->swevent_hlist
,
6718 lockdep_is_held(&swhash
->hlist_mutex
));
6721 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6723 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6728 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6729 kfree_rcu(hlist
, rcu_head
);
6732 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6734 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6736 mutex_lock(&swhash
->hlist_mutex
);
6738 if (!--swhash
->hlist_refcount
)
6739 swevent_hlist_release(swhash
);
6741 mutex_unlock(&swhash
->hlist_mutex
);
6744 static void swevent_hlist_put(struct perf_event
*event
)
6748 for_each_possible_cpu(cpu
)
6749 swevent_hlist_put_cpu(event
, cpu
);
6752 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6754 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6757 mutex_lock(&swhash
->hlist_mutex
);
6758 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6759 struct swevent_hlist
*hlist
;
6761 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6766 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6768 swhash
->hlist_refcount
++;
6770 mutex_unlock(&swhash
->hlist_mutex
);
6775 static int swevent_hlist_get(struct perf_event
*event
)
6778 int cpu
, failed_cpu
;
6781 for_each_possible_cpu(cpu
) {
6782 err
= swevent_hlist_get_cpu(event
, cpu
);
6792 for_each_possible_cpu(cpu
) {
6793 if (cpu
== failed_cpu
)
6795 swevent_hlist_put_cpu(event
, cpu
);
6802 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6804 static void sw_perf_event_destroy(struct perf_event
*event
)
6806 u64 event_id
= event
->attr
.config
;
6808 WARN_ON(event
->parent
);
6810 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6811 swevent_hlist_put(event
);
6814 static int perf_swevent_init(struct perf_event
*event
)
6816 u64 event_id
= event
->attr
.config
;
6818 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6822 * no branch sampling for software events
6824 if (has_branch_stack(event
))
6828 case PERF_COUNT_SW_CPU_CLOCK
:
6829 case PERF_COUNT_SW_TASK_CLOCK
:
6836 if (event_id
>= PERF_COUNT_SW_MAX
)
6839 if (!event
->parent
) {
6842 err
= swevent_hlist_get(event
);
6846 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6847 event
->destroy
= sw_perf_event_destroy
;
6853 static struct pmu perf_swevent
= {
6854 .task_ctx_nr
= perf_sw_context
,
6856 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6858 .event_init
= perf_swevent_init
,
6859 .add
= perf_swevent_add
,
6860 .del
= perf_swevent_del
,
6861 .start
= perf_swevent_start
,
6862 .stop
= perf_swevent_stop
,
6863 .read
= perf_swevent_read
,
6866 #ifdef CONFIG_EVENT_TRACING
6868 static int perf_tp_filter_match(struct perf_event
*event
,
6869 struct perf_sample_data
*data
)
6871 void *record
= data
->raw
->data
;
6873 /* only top level events have filters set */
6875 event
= event
->parent
;
6877 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6882 static int perf_tp_event_match(struct perf_event
*event
,
6883 struct perf_sample_data
*data
,
6884 struct pt_regs
*regs
)
6886 if (event
->hw
.state
& PERF_HES_STOPPED
)
6889 * All tracepoints are from kernel-space.
6891 if (event
->attr
.exclude_kernel
)
6894 if (!perf_tp_filter_match(event
, data
))
6900 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6901 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6902 struct task_struct
*task
)
6904 struct perf_sample_data data
;
6905 struct perf_event
*event
;
6907 struct perf_raw_record raw
= {
6912 perf_sample_data_init(&data
, addr
, 0);
6915 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6916 if (perf_tp_event_match(event
, &data
, regs
))
6917 perf_swevent_event(event
, count
, &data
, regs
);
6921 * If we got specified a target task, also iterate its context and
6922 * deliver this event there too.
6924 if (task
&& task
!= current
) {
6925 struct perf_event_context
*ctx
;
6926 struct trace_entry
*entry
= record
;
6929 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6933 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6934 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6936 if (event
->attr
.config
!= entry
->type
)
6938 if (perf_tp_event_match(event
, &data
, regs
))
6939 perf_swevent_event(event
, count
, &data
, regs
);
6945 perf_swevent_put_recursion_context(rctx
);
6947 EXPORT_SYMBOL_GPL(perf_tp_event
);
6949 static void tp_perf_event_destroy(struct perf_event
*event
)
6951 perf_trace_destroy(event
);
6954 static int perf_tp_event_init(struct perf_event
*event
)
6958 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6962 * no branch sampling for tracepoint events
6964 if (has_branch_stack(event
))
6967 err
= perf_trace_init(event
);
6971 event
->destroy
= tp_perf_event_destroy
;
6976 static struct pmu perf_tracepoint
= {
6977 .task_ctx_nr
= perf_sw_context
,
6979 .event_init
= perf_tp_event_init
,
6980 .add
= perf_trace_add
,
6981 .del
= perf_trace_del
,
6982 .start
= perf_swevent_start
,
6983 .stop
= perf_swevent_stop
,
6984 .read
= perf_swevent_read
,
6987 static inline void perf_tp_register(void)
6989 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
6992 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6997 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7000 filter_str
= strndup_user(arg
, PAGE_SIZE
);
7001 if (IS_ERR(filter_str
))
7002 return PTR_ERR(filter_str
);
7004 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
7010 static void perf_event_free_filter(struct perf_event
*event
)
7012 ftrace_profile_free_filter(event
);
7015 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7017 struct bpf_prog
*prog
;
7019 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7022 if (event
->tp_event
->prog
)
7025 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
7026 /* bpf programs can only be attached to u/kprobes */
7029 prog
= bpf_prog_get(prog_fd
);
7031 return PTR_ERR(prog
);
7033 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7034 /* valid fd, but invalid bpf program type */
7039 event
->tp_event
->prog
= prog
;
7044 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7046 struct bpf_prog
*prog
;
7048 if (!event
->tp_event
)
7051 prog
= event
->tp_event
->prog
;
7053 event
->tp_event
->prog
= NULL
;
7060 static inline void perf_tp_register(void)
7064 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7069 static void perf_event_free_filter(struct perf_event
*event
)
7073 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7078 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7081 #endif /* CONFIG_EVENT_TRACING */
7083 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7084 void perf_bp_event(struct perf_event
*bp
, void *data
)
7086 struct perf_sample_data sample
;
7087 struct pt_regs
*regs
= data
;
7089 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7091 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7092 perf_swevent_event(bp
, 1, &sample
, regs
);
7097 * hrtimer based swevent callback
7100 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7102 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7103 struct perf_sample_data data
;
7104 struct pt_regs
*regs
;
7105 struct perf_event
*event
;
7108 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7110 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7111 return HRTIMER_NORESTART
;
7113 event
->pmu
->read(event
);
7115 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7116 regs
= get_irq_regs();
7118 if (regs
&& !perf_exclude_event(event
, regs
)) {
7119 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7120 if (__perf_event_overflow(event
, 1, &data
, regs
))
7121 ret
= HRTIMER_NORESTART
;
7124 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7125 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7130 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7132 struct hw_perf_event
*hwc
= &event
->hw
;
7135 if (!is_sampling_event(event
))
7138 period
= local64_read(&hwc
->period_left
);
7143 local64_set(&hwc
->period_left
, 0);
7145 period
= max_t(u64
, 10000, hwc
->sample_period
);
7147 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7148 HRTIMER_MODE_REL_PINNED
);
7151 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7153 struct hw_perf_event
*hwc
= &event
->hw
;
7155 if (is_sampling_event(event
)) {
7156 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7157 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7159 hrtimer_cancel(&hwc
->hrtimer
);
7163 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7165 struct hw_perf_event
*hwc
= &event
->hw
;
7167 if (!is_sampling_event(event
))
7170 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7171 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7174 * Since hrtimers have a fixed rate, we can do a static freq->period
7175 * mapping and avoid the whole period adjust feedback stuff.
7177 if (event
->attr
.freq
) {
7178 long freq
= event
->attr
.sample_freq
;
7180 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7181 hwc
->sample_period
= event
->attr
.sample_period
;
7182 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7183 hwc
->last_period
= hwc
->sample_period
;
7184 event
->attr
.freq
= 0;
7189 * Software event: cpu wall time clock
7192 static void cpu_clock_event_update(struct perf_event
*event
)
7197 now
= local_clock();
7198 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7199 local64_add(now
- prev
, &event
->count
);
7202 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7204 local64_set(&event
->hw
.prev_count
, local_clock());
7205 perf_swevent_start_hrtimer(event
);
7208 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7210 perf_swevent_cancel_hrtimer(event
);
7211 cpu_clock_event_update(event
);
7214 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7216 if (flags
& PERF_EF_START
)
7217 cpu_clock_event_start(event
, flags
);
7218 perf_event_update_userpage(event
);
7223 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7225 cpu_clock_event_stop(event
, flags
);
7228 static void cpu_clock_event_read(struct perf_event
*event
)
7230 cpu_clock_event_update(event
);
7233 static int cpu_clock_event_init(struct perf_event
*event
)
7235 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7238 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7242 * no branch sampling for software events
7244 if (has_branch_stack(event
))
7247 perf_swevent_init_hrtimer(event
);
7252 static struct pmu perf_cpu_clock
= {
7253 .task_ctx_nr
= perf_sw_context
,
7255 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7257 .event_init
= cpu_clock_event_init
,
7258 .add
= cpu_clock_event_add
,
7259 .del
= cpu_clock_event_del
,
7260 .start
= cpu_clock_event_start
,
7261 .stop
= cpu_clock_event_stop
,
7262 .read
= cpu_clock_event_read
,
7266 * Software event: task time clock
7269 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7274 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7276 local64_add(delta
, &event
->count
);
7279 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7281 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7282 perf_swevent_start_hrtimer(event
);
7285 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7287 perf_swevent_cancel_hrtimer(event
);
7288 task_clock_event_update(event
, event
->ctx
->time
);
7291 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7293 if (flags
& PERF_EF_START
)
7294 task_clock_event_start(event
, flags
);
7295 perf_event_update_userpage(event
);
7300 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7302 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7305 static void task_clock_event_read(struct perf_event
*event
)
7307 u64 now
= perf_clock();
7308 u64 delta
= now
- event
->ctx
->timestamp
;
7309 u64 time
= event
->ctx
->time
+ delta
;
7311 task_clock_event_update(event
, time
);
7314 static int task_clock_event_init(struct perf_event
*event
)
7316 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7319 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7323 * no branch sampling for software events
7325 if (has_branch_stack(event
))
7328 perf_swevent_init_hrtimer(event
);
7333 static struct pmu perf_task_clock
= {
7334 .task_ctx_nr
= perf_sw_context
,
7336 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7338 .event_init
= task_clock_event_init
,
7339 .add
= task_clock_event_add
,
7340 .del
= task_clock_event_del
,
7341 .start
= task_clock_event_start
,
7342 .stop
= task_clock_event_stop
,
7343 .read
= task_clock_event_read
,
7346 static void perf_pmu_nop_void(struct pmu
*pmu
)
7350 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7354 static int perf_pmu_nop_int(struct pmu
*pmu
)
7359 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7361 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7363 __this_cpu_write(nop_txn_flags
, flags
);
7365 if (flags
& ~PERF_PMU_TXN_ADD
)
7368 perf_pmu_disable(pmu
);
7371 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7373 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7375 __this_cpu_write(nop_txn_flags
, 0);
7377 if (flags
& ~PERF_PMU_TXN_ADD
)
7380 perf_pmu_enable(pmu
);
7384 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7386 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7388 __this_cpu_write(nop_txn_flags
, 0);
7390 if (flags
& ~PERF_PMU_TXN_ADD
)
7393 perf_pmu_enable(pmu
);
7396 static int perf_event_idx_default(struct perf_event
*event
)
7402 * Ensures all contexts with the same task_ctx_nr have the same
7403 * pmu_cpu_context too.
7405 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7412 list_for_each_entry(pmu
, &pmus
, entry
) {
7413 if (pmu
->task_ctx_nr
== ctxn
)
7414 return pmu
->pmu_cpu_context
;
7420 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7424 for_each_possible_cpu(cpu
) {
7425 struct perf_cpu_context
*cpuctx
;
7427 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7429 if (cpuctx
->unique_pmu
== old_pmu
)
7430 cpuctx
->unique_pmu
= pmu
;
7434 static void free_pmu_context(struct pmu
*pmu
)
7438 mutex_lock(&pmus_lock
);
7440 * Like a real lame refcount.
7442 list_for_each_entry(i
, &pmus
, entry
) {
7443 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7444 update_pmu_context(i
, pmu
);
7449 free_percpu(pmu
->pmu_cpu_context
);
7451 mutex_unlock(&pmus_lock
);
7453 static struct idr pmu_idr
;
7456 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7458 struct pmu
*pmu
= dev_get_drvdata(dev
);
7460 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7462 static DEVICE_ATTR_RO(type
);
7465 perf_event_mux_interval_ms_show(struct device
*dev
,
7466 struct device_attribute
*attr
,
7469 struct pmu
*pmu
= dev_get_drvdata(dev
);
7471 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7474 static DEFINE_MUTEX(mux_interval_mutex
);
7477 perf_event_mux_interval_ms_store(struct device
*dev
,
7478 struct device_attribute
*attr
,
7479 const char *buf
, size_t count
)
7481 struct pmu
*pmu
= dev_get_drvdata(dev
);
7482 int timer
, cpu
, ret
;
7484 ret
= kstrtoint(buf
, 0, &timer
);
7491 /* same value, noting to do */
7492 if (timer
== pmu
->hrtimer_interval_ms
)
7495 mutex_lock(&mux_interval_mutex
);
7496 pmu
->hrtimer_interval_ms
= timer
;
7498 /* update all cpuctx for this PMU */
7500 for_each_online_cpu(cpu
) {
7501 struct perf_cpu_context
*cpuctx
;
7502 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7503 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7505 cpu_function_call(cpu
,
7506 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7509 mutex_unlock(&mux_interval_mutex
);
7513 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7515 static struct attribute
*pmu_dev_attrs
[] = {
7516 &dev_attr_type
.attr
,
7517 &dev_attr_perf_event_mux_interval_ms
.attr
,
7520 ATTRIBUTE_GROUPS(pmu_dev
);
7522 static int pmu_bus_running
;
7523 static struct bus_type pmu_bus
= {
7524 .name
= "event_source",
7525 .dev_groups
= pmu_dev_groups
,
7528 static void pmu_dev_release(struct device
*dev
)
7533 static int pmu_dev_alloc(struct pmu
*pmu
)
7537 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7541 pmu
->dev
->groups
= pmu
->attr_groups
;
7542 device_initialize(pmu
->dev
);
7543 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7547 dev_set_drvdata(pmu
->dev
, pmu
);
7548 pmu
->dev
->bus
= &pmu_bus
;
7549 pmu
->dev
->release
= pmu_dev_release
;
7550 ret
= device_add(pmu
->dev
);
7558 put_device(pmu
->dev
);
7562 static struct lock_class_key cpuctx_mutex
;
7563 static struct lock_class_key cpuctx_lock
;
7565 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7569 mutex_lock(&pmus_lock
);
7571 pmu
->pmu_disable_count
= alloc_percpu(int);
7572 if (!pmu
->pmu_disable_count
)
7581 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7589 if (pmu_bus_running
) {
7590 ret
= pmu_dev_alloc(pmu
);
7596 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7597 if (pmu
->pmu_cpu_context
)
7598 goto got_cpu_context
;
7601 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7602 if (!pmu
->pmu_cpu_context
)
7605 for_each_possible_cpu(cpu
) {
7606 struct perf_cpu_context
*cpuctx
;
7608 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7609 __perf_event_init_context(&cpuctx
->ctx
);
7610 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7611 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7612 cpuctx
->ctx
.pmu
= pmu
;
7614 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7616 cpuctx
->unique_pmu
= pmu
;
7620 if (!pmu
->start_txn
) {
7621 if (pmu
->pmu_enable
) {
7623 * If we have pmu_enable/pmu_disable calls, install
7624 * transaction stubs that use that to try and batch
7625 * hardware accesses.
7627 pmu
->start_txn
= perf_pmu_start_txn
;
7628 pmu
->commit_txn
= perf_pmu_commit_txn
;
7629 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7631 pmu
->start_txn
= perf_pmu_nop_txn
;
7632 pmu
->commit_txn
= perf_pmu_nop_int
;
7633 pmu
->cancel_txn
= perf_pmu_nop_void
;
7637 if (!pmu
->pmu_enable
) {
7638 pmu
->pmu_enable
= perf_pmu_nop_void
;
7639 pmu
->pmu_disable
= perf_pmu_nop_void
;
7642 if (!pmu
->event_idx
)
7643 pmu
->event_idx
= perf_event_idx_default
;
7645 list_add_rcu(&pmu
->entry
, &pmus
);
7646 atomic_set(&pmu
->exclusive_cnt
, 0);
7649 mutex_unlock(&pmus_lock
);
7654 device_del(pmu
->dev
);
7655 put_device(pmu
->dev
);
7658 if (pmu
->type
>= PERF_TYPE_MAX
)
7659 idr_remove(&pmu_idr
, pmu
->type
);
7662 free_percpu(pmu
->pmu_disable_count
);
7665 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7667 void perf_pmu_unregister(struct pmu
*pmu
)
7669 mutex_lock(&pmus_lock
);
7670 list_del_rcu(&pmu
->entry
);
7671 mutex_unlock(&pmus_lock
);
7674 * We dereference the pmu list under both SRCU and regular RCU, so
7675 * synchronize against both of those.
7677 synchronize_srcu(&pmus_srcu
);
7680 free_percpu(pmu
->pmu_disable_count
);
7681 if (pmu
->type
>= PERF_TYPE_MAX
)
7682 idr_remove(&pmu_idr
, pmu
->type
);
7683 device_del(pmu
->dev
);
7684 put_device(pmu
->dev
);
7685 free_pmu_context(pmu
);
7687 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7689 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7691 struct perf_event_context
*ctx
= NULL
;
7694 if (!try_module_get(pmu
->module
))
7697 if (event
->group_leader
!= event
) {
7699 * This ctx->mutex can nest when we're called through
7700 * inheritance. See the perf_event_ctx_lock_nested() comment.
7702 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7703 SINGLE_DEPTH_NESTING
);
7708 ret
= pmu
->event_init(event
);
7711 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7714 module_put(pmu
->module
);
7719 static struct pmu
*perf_init_event(struct perf_event
*event
)
7721 struct pmu
*pmu
= NULL
;
7725 idx
= srcu_read_lock(&pmus_srcu
);
7728 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7731 ret
= perf_try_init_event(pmu
, event
);
7737 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7738 ret
= perf_try_init_event(pmu
, event
);
7742 if (ret
!= -ENOENT
) {
7747 pmu
= ERR_PTR(-ENOENT
);
7749 srcu_read_unlock(&pmus_srcu
, idx
);
7754 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7759 if (is_cgroup_event(event
))
7760 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7763 static void account_event(struct perf_event
*event
)
7770 if (event
->attach_state
& PERF_ATTACH_TASK
)
7772 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7773 atomic_inc(&nr_mmap_events
);
7774 if (event
->attr
.comm
)
7775 atomic_inc(&nr_comm_events
);
7776 if (event
->attr
.task
)
7777 atomic_inc(&nr_task_events
);
7778 if (event
->attr
.freq
) {
7779 if (atomic_inc_return(&nr_freq_events
) == 1)
7780 tick_nohz_full_kick_all();
7782 if (event
->attr
.context_switch
) {
7783 atomic_inc(&nr_switch_events
);
7786 if (has_branch_stack(event
))
7788 if (is_cgroup_event(event
))
7792 static_key_slow_inc(&perf_sched_events
.key
);
7794 account_event_cpu(event
, event
->cpu
);
7798 * Allocate and initialize a event structure
7800 static struct perf_event
*
7801 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7802 struct task_struct
*task
,
7803 struct perf_event
*group_leader
,
7804 struct perf_event
*parent_event
,
7805 perf_overflow_handler_t overflow_handler
,
7806 void *context
, int cgroup_fd
)
7809 struct perf_event
*event
;
7810 struct hw_perf_event
*hwc
;
7813 if ((unsigned)cpu
>= nr_cpu_ids
) {
7814 if (!task
|| cpu
!= -1)
7815 return ERR_PTR(-EINVAL
);
7818 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7820 return ERR_PTR(-ENOMEM
);
7823 * Single events are their own group leaders, with an
7824 * empty sibling list:
7827 group_leader
= event
;
7829 mutex_init(&event
->child_mutex
);
7830 INIT_LIST_HEAD(&event
->child_list
);
7832 INIT_LIST_HEAD(&event
->group_entry
);
7833 INIT_LIST_HEAD(&event
->event_entry
);
7834 INIT_LIST_HEAD(&event
->sibling_list
);
7835 INIT_LIST_HEAD(&event
->rb_entry
);
7836 INIT_LIST_HEAD(&event
->active_entry
);
7837 INIT_HLIST_NODE(&event
->hlist_entry
);
7840 init_waitqueue_head(&event
->waitq
);
7841 init_irq_work(&event
->pending
, perf_pending_event
);
7843 mutex_init(&event
->mmap_mutex
);
7845 atomic_long_set(&event
->refcount
, 1);
7847 event
->attr
= *attr
;
7848 event
->group_leader
= group_leader
;
7852 event
->parent
= parent_event
;
7854 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7855 event
->id
= atomic64_inc_return(&perf_event_id
);
7857 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7860 event
->attach_state
= PERF_ATTACH_TASK
;
7862 * XXX pmu::event_init needs to know what task to account to
7863 * and we cannot use the ctx information because we need the
7864 * pmu before we get a ctx.
7866 event
->hw
.target
= task
;
7869 event
->clock
= &local_clock
;
7871 event
->clock
= parent_event
->clock
;
7873 if (!overflow_handler
&& parent_event
) {
7874 overflow_handler
= parent_event
->overflow_handler
;
7875 context
= parent_event
->overflow_handler_context
;
7878 event
->overflow_handler
= overflow_handler
;
7879 event
->overflow_handler_context
= context
;
7881 perf_event__state_init(event
);
7886 hwc
->sample_period
= attr
->sample_period
;
7887 if (attr
->freq
&& attr
->sample_freq
)
7888 hwc
->sample_period
= 1;
7889 hwc
->last_period
= hwc
->sample_period
;
7891 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7894 * we currently do not support PERF_FORMAT_GROUP on inherited events
7896 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7899 if (!has_branch_stack(event
))
7900 event
->attr
.branch_sample_type
= 0;
7902 if (cgroup_fd
!= -1) {
7903 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7908 pmu
= perf_init_event(event
);
7911 else if (IS_ERR(pmu
)) {
7916 err
= exclusive_event_init(event
);
7920 if (!event
->parent
) {
7921 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7922 err
= get_callchain_buffers();
7931 exclusive_event_destroy(event
);
7935 event
->destroy(event
);
7936 module_put(pmu
->module
);
7938 if (is_cgroup_event(event
))
7939 perf_detach_cgroup(event
);
7941 put_pid_ns(event
->ns
);
7944 return ERR_PTR(err
);
7947 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
7948 struct perf_event_attr
*attr
)
7953 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
7957 * zero the full structure, so that a short copy will be nice.
7959 memset(attr
, 0, sizeof(*attr
));
7961 ret
= get_user(size
, &uattr
->size
);
7965 if (size
> PAGE_SIZE
) /* silly large */
7968 if (!size
) /* abi compat */
7969 size
= PERF_ATTR_SIZE_VER0
;
7971 if (size
< PERF_ATTR_SIZE_VER0
)
7975 * If we're handed a bigger struct than we know of,
7976 * ensure all the unknown bits are 0 - i.e. new
7977 * user-space does not rely on any kernel feature
7978 * extensions we dont know about yet.
7980 if (size
> sizeof(*attr
)) {
7981 unsigned char __user
*addr
;
7982 unsigned char __user
*end
;
7985 addr
= (void __user
*)uattr
+ sizeof(*attr
);
7986 end
= (void __user
*)uattr
+ size
;
7988 for (; addr
< end
; addr
++) {
7989 ret
= get_user(val
, addr
);
7995 size
= sizeof(*attr
);
7998 ret
= copy_from_user(attr
, uattr
, size
);
8002 if (attr
->__reserved_1
)
8005 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
8008 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
8011 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
8012 u64 mask
= attr
->branch_sample_type
;
8014 /* only using defined bits */
8015 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
8018 /* at least one branch bit must be set */
8019 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
8022 /* propagate priv level, when not set for branch */
8023 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
8025 /* exclude_kernel checked on syscall entry */
8026 if (!attr
->exclude_kernel
)
8027 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8029 if (!attr
->exclude_user
)
8030 mask
|= PERF_SAMPLE_BRANCH_USER
;
8032 if (!attr
->exclude_hv
)
8033 mask
|= PERF_SAMPLE_BRANCH_HV
;
8035 * adjust user setting (for HW filter setup)
8037 attr
->branch_sample_type
= mask
;
8039 /* privileged levels capture (kernel, hv): check permissions */
8040 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8041 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8045 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8046 ret
= perf_reg_validate(attr
->sample_regs_user
);
8051 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8052 if (!arch_perf_have_user_stack_dump())
8056 * We have __u32 type for the size, but so far
8057 * we can only use __u16 as maximum due to the
8058 * __u16 sample size limit.
8060 if (attr
->sample_stack_user
>= USHRT_MAX
)
8062 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8066 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8067 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8072 put_user(sizeof(*attr
), &uattr
->size
);
8078 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8080 struct ring_buffer
*rb
= NULL
;
8086 /* don't allow circular references */
8087 if (event
== output_event
)
8091 * Don't allow cross-cpu buffers
8093 if (output_event
->cpu
!= event
->cpu
)
8097 * If its not a per-cpu rb, it must be the same task.
8099 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8103 * Mixing clocks in the same buffer is trouble you don't need.
8105 if (output_event
->clock
!= event
->clock
)
8109 * If both events generate aux data, they must be on the same PMU
8111 if (has_aux(event
) && has_aux(output_event
) &&
8112 event
->pmu
!= output_event
->pmu
)
8116 mutex_lock(&event
->mmap_mutex
);
8117 /* Can't redirect output if we've got an active mmap() */
8118 if (atomic_read(&event
->mmap_count
))
8122 /* get the rb we want to redirect to */
8123 rb
= ring_buffer_get(output_event
);
8128 ring_buffer_attach(event
, rb
);
8132 mutex_unlock(&event
->mmap_mutex
);
8138 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8144 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8147 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8149 bool nmi_safe
= false;
8152 case CLOCK_MONOTONIC
:
8153 event
->clock
= &ktime_get_mono_fast_ns
;
8157 case CLOCK_MONOTONIC_RAW
:
8158 event
->clock
= &ktime_get_raw_fast_ns
;
8162 case CLOCK_REALTIME
:
8163 event
->clock
= &ktime_get_real_ns
;
8166 case CLOCK_BOOTTIME
:
8167 event
->clock
= &ktime_get_boot_ns
;
8171 event
->clock
= &ktime_get_tai_ns
;
8178 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8185 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8187 * @attr_uptr: event_id type attributes for monitoring/sampling
8190 * @group_fd: group leader event fd
8192 SYSCALL_DEFINE5(perf_event_open
,
8193 struct perf_event_attr __user
*, attr_uptr
,
8194 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8196 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8197 struct perf_event
*event
, *sibling
;
8198 struct perf_event_attr attr
;
8199 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8200 struct file
*event_file
= NULL
;
8201 struct fd group
= {NULL
, 0};
8202 struct task_struct
*task
= NULL
;
8207 int f_flags
= O_RDWR
;
8210 /* for future expandability... */
8211 if (flags
& ~PERF_FLAG_ALL
)
8214 err
= perf_copy_attr(attr_uptr
, &attr
);
8218 if (!attr
.exclude_kernel
) {
8219 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8224 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8227 if (attr
.sample_period
& (1ULL << 63))
8232 * In cgroup mode, the pid argument is used to pass the fd
8233 * opened to the cgroup directory in cgroupfs. The cpu argument
8234 * designates the cpu on which to monitor threads from that
8237 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8240 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8241 f_flags
|= O_CLOEXEC
;
8243 event_fd
= get_unused_fd_flags(f_flags
);
8247 if (group_fd
!= -1) {
8248 err
= perf_fget_light(group_fd
, &group
);
8251 group_leader
= group
.file
->private_data
;
8252 if (flags
& PERF_FLAG_FD_OUTPUT
)
8253 output_event
= group_leader
;
8254 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8255 group_leader
= NULL
;
8258 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8259 task
= find_lively_task_by_vpid(pid
);
8261 err
= PTR_ERR(task
);
8266 if (task
&& group_leader
&&
8267 group_leader
->attr
.inherit
!= attr
.inherit
) {
8274 if (flags
& PERF_FLAG_PID_CGROUP
)
8277 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8278 NULL
, NULL
, cgroup_fd
);
8279 if (IS_ERR(event
)) {
8280 err
= PTR_ERR(event
);
8284 if (is_sampling_event(event
)) {
8285 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8291 account_event(event
);
8294 * Special case software events and allow them to be part of
8295 * any hardware group.
8299 if (attr
.use_clockid
) {
8300 err
= perf_event_set_clock(event
, attr
.clockid
);
8306 (is_software_event(event
) != is_software_event(group_leader
))) {
8307 if (is_software_event(event
)) {
8309 * If event and group_leader are not both a software
8310 * event, and event is, then group leader is not.
8312 * Allow the addition of software events to !software
8313 * groups, this is safe because software events never
8316 pmu
= group_leader
->pmu
;
8317 } else if (is_software_event(group_leader
) &&
8318 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8320 * In case the group is a pure software group, and we
8321 * try to add a hardware event, move the whole group to
8322 * the hardware context.
8329 * Get the target context (task or percpu):
8331 ctx
= find_get_context(pmu
, task
, event
);
8337 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8343 put_task_struct(task
);
8348 * Look up the group leader (we will attach this event to it):
8354 * Do not allow a recursive hierarchy (this new sibling
8355 * becoming part of another group-sibling):
8357 if (group_leader
->group_leader
!= group_leader
)
8360 /* All events in a group should have the same clock */
8361 if (group_leader
->clock
!= event
->clock
)
8365 * Do not allow to attach to a group in a different
8366 * task or CPU context:
8370 * Make sure we're both on the same task, or both
8373 if (group_leader
->ctx
->task
!= ctx
->task
)
8377 * Make sure we're both events for the same CPU;
8378 * grouping events for different CPUs is broken; since
8379 * you can never concurrently schedule them anyhow.
8381 if (group_leader
->cpu
!= event
->cpu
)
8384 if (group_leader
->ctx
!= ctx
)
8389 * Only a group leader can be exclusive or pinned
8391 if (attr
.exclusive
|| attr
.pinned
)
8396 err
= perf_event_set_output(event
, output_event
);
8401 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8403 if (IS_ERR(event_file
)) {
8404 err
= PTR_ERR(event_file
);
8409 gctx
= group_leader
->ctx
;
8410 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8412 mutex_lock(&ctx
->mutex
);
8415 if (!perf_event_validate_size(event
)) {
8421 * Must be under the same ctx::mutex as perf_install_in_context(),
8422 * because we need to serialize with concurrent event creation.
8424 if (!exclusive_event_installable(event
, ctx
)) {
8425 /* exclusive and group stuff are assumed mutually exclusive */
8426 WARN_ON_ONCE(move_group
);
8432 WARN_ON_ONCE(ctx
->parent_ctx
);
8436 * See perf_event_ctx_lock() for comments on the details
8437 * of swizzling perf_event::ctx.
8439 perf_remove_from_context(group_leader
, false);
8441 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8443 perf_remove_from_context(sibling
, false);
8448 * Wait for everybody to stop referencing the events through
8449 * the old lists, before installing it on new lists.
8454 * Install the group siblings before the group leader.
8456 * Because a group leader will try and install the entire group
8457 * (through the sibling list, which is still in-tact), we can
8458 * end up with siblings installed in the wrong context.
8460 * By installing siblings first we NO-OP because they're not
8461 * reachable through the group lists.
8463 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8465 perf_event__state_init(sibling
);
8466 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8471 * Removing from the context ends up with disabled
8472 * event. What we want here is event in the initial
8473 * startup state, ready to be add into new context.
8475 perf_event__state_init(group_leader
);
8476 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8480 * Now that all events are installed in @ctx, nothing
8481 * references @gctx anymore, so drop the last reference we have
8488 * Precalculate sample_data sizes; do while holding ctx::mutex such
8489 * that we're serialized against further additions and before
8490 * perf_install_in_context() which is the point the event is active and
8491 * can use these values.
8493 perf_event__header_size(event
);
8494 perf_event__id_header_size(event
);
8496 perf_install_in_context(ctx
, event
, event
->cpu
);
8497 perf_unpin_context(ctx
);
8500 mutex_unlock(&gctx
->mutex
);
8501 mutex_unlock(&ctx
->mutex
);
8505 event
->owner
= current
;
8507 mutex_lock(¤t
->perf_event_mutex
);
8508 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8509 mutex_unlock(¤t
->perf_event_mutex
);
8512 * Drop the reference on the group_event after placing the
8513 * new event on the sibling_list. This ensures destruction
8514 * of the group leader will find the pointer to itself in
8515 * perf_group_detach().
8518 fd_install(event_fd
, event_file
);
8523 mutex_unlock(&gctx
->mutex
);
8524 mutex_unlock(&ctx
->mutex
);
8528 perf_unpin_context(ctx
);
8536 put_task_struct(task
);
8540 put_unused_fd(event_fd
);
8545 * perf_event_create_kernel_counter
8547 * @attr: attributes of the counter to create
8548 * @cpu: cpu in which the counter is bound
8549 * @task: task to profile (NULL for percpu)
8552 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8553 struct task_struct
*task
,
8554 perf_overflow_handler_t overflow_handler
,
8557 struct perf_event_context
*ctx
;
8558 struct perf_event
*event
;
8562 * Get the target context (task or percpu):
8565 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8566 overflow_handler
, context
, -1);
8567 if (IS_ERR(event
)) {
8568 err
= PTR_ERR(event
);
8572 /* Mark owner so we could distinguish it from user events. */
8573 event
->owner
= EVENT_OWNER_KERNEL
;
8575 account_event(event
);
8577 ctx
= find_get_context(event
->pmu
, task
, event
);
8583 WARN_ON_ONCE(ctx
->parent_ctx
);
8584 mutex_lock(&ctx
->mutex
);
8585 if (!exclusive_event_installable(event
, ctx
)) {
8586 mutex_unlock(&ctx
->mutex
);
8587 perf_unpin_context(ctx
);
8593 perf_install_in_context(ctx
, event
, cpu
);
8594 perf_unpin_context(ctx
);
8595 mutex_unlock(&ctx
->mutex
);
8602 return ERR_PTR(err
);
8604 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8606 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8608 struct perf_event_context
*src_ctx
;
8609 struct perf_event_context
*dst_ctx
;
8610 struct perf_event
*event
, *tmp
;
8613 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8614 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8617 * See perf_event_ctx_lock() for comments on the details
8618 * of swizzling perf_event::ctx.
8620 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8621 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8623 perf_remove_from_context(event
, false);
8624 unaccount_event_cpu(event
, src_cpu
);
8626 list_add(&event
->migrate_entry
, &events
);
8630 * Wait for the events to quiesce before re-instating them.
8635 * Re-instate events in 2 passes.
8637 * Skip over group leaders and only install siblings on this first
8638 * pass, siblings will not get enabled without a leader, however a
8639 * leader will enable its siblings, even if those are still on the old
8642 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8643 if (event
->group_leader
== event
)
8646 list_del(&event
->migrate_entry
);
8647 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8648 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8649 account_event_cpu(event
, dst_cpu
);
8650 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8655 * Once all the siblings are setup properly, install the group leaders
8658 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8659 list_del(&event
->migrate_entry
);
8660 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8661 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8662 account_event_cpu(event
, dst_cpu
);
8663 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8666 mutex_unlock(&dst_ctx
->mutex
);
8667 mutex_unlock(&src_ctx
->mutex
);
8669 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8671 static void sync_child_event(struct perf_event
*child_event
,
8672 struct task_struct
*child
)
8674 struct perf_event
*parent_event
= child_event
->parent
;
8677 if (child_event
->attr
.inherit_stat
)
8678 perf_event_read_event(child_event
, child
);
8680 child_val
= perf_event_count(child_event
);
8683 * Add back the child's count to the parent's count:
8685 atomic64_add(child_val
, &parent_event
->child_count
);
8686 atomic64_add(child_event
->total_time_enabled
,
8687 &parent_event
->child_total_time_enabled
);
8688 atomic64_add(child_event
->total_time_running
,
8689 &parent_event
->child_total_time_running
);
8692 * Remove this event from the parent's list
8694 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8695 mutex_lock(&parent_event
->child_mutex
);
8696 list_del_init(&child_event
->child_list
);
8697 mutex_unlock(&parent_event
->child_mutex
);
8700 * Make sure user/parent get notified, that we just
8703 perf_event_wakeup(parent_event
);
8706 * Release the parent event, if this was the last
8709 put_event(parent_event
);
8713 __perf_event_exit_task(struct perf_event
*child_event
,
8714 struct perf_event_context
*child_ctx
,
8715 struct task_struct
*child
)
8718 * Do not destroy the 'original' grouping; because of the context
8719 * switch optimization the original events could've ended up in a
8720 * random child task.
8722 * If we were to destroy the original group, all group related
8723 * operations would cease to function properly after this random
8726 * Do destroy all inherited groups, we don't care about those
8727 * and being thorough is better.
8729 perf_remove_from_context(child_event
, !!child_event
->parent
);
8732 * It can happen that the parent exits first, and has events
8733 * that are still around due to the child reference. These
8734 * events need to be zapped.
8736 if (child_event
->parent
) {
8737 sync_child_event(child_event
, child
);
8738 free_event(child_event
);
8740 child_event
->state
= PERF_EVENT_STATE_EXIT
;
8741 perf_event_wakeup(child_event
);
8745 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8747 struct perf_event
*child_event
, *next
;
8748 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8749 unsigned long flags
;
8751 if (likely(!child
->perf_event_ctxp
[ctxn
]))
8754 local_irq_save(flags
);
8756 * We can't reschedule here because interrupts are disabled,
8757 * and either child is current or it is a task that can't be
8758 * scheduled, so we are now safe from rescheduling changing
8761 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
8764 * Take the context lock here so that if find_get_context is
8765 * reading child->perf_event_ctxp, we wait until it has
8766 * incremented the context's refcount before we do put_ctx below.
8768 raw_spin_lock(&child_ctx
->lock
);
8769 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
);
8770 child
->perf_event_ctxp
[ctxn
] = NULL
;
8773 * If this context is a clone; unclone it so it can't get
8774 * swapped to another process while we're removing all
8775 * the events from it.
8777 clone_ctx
= unclone_ctx(child_ctx
);
8778 update_context_time(child_ctx
);
8779 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8785 * Report the task dead after unscheduling the events so that we
8786 * won't get any samples after PERF_RECORD_EXIT. We can however still
8787 * get a few PERF_RECORD_READ events.
8789 perf_event_task(child
, child_ctx
, 0);
8792 * We can recurse on the same lock type through:
8794 * __perf_event_exit_task()
8795 * sync_child_event()
8797 * mutex_lock(&ctx->mutex)
8799 * But since its the parent context it won't be the same instance.
8801 mutex_lock(&child_ctx
->mutex
);
8803 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8804 __perf_event_exit_task(child_event
, child_ctx
, child
);
8806 mutex_unlock(&child_ctx
->mutex
);
8812 * When a child task exits, feed back event values to parent events.
8814 void perf_event_exit_task(struct task_struct
*child
)
8816 struct perf_event
*event
, *tmp
;
8819 mutex_lock(&child
->perf_event_mutex
);
8820 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8822 list_del_init(&event
->owner_entry
);
8825 * Ensure the list deletion is visible before we clear
8826 * the owner, closes a race against perf_release() where
8827 * we need to serialize on the owner->perf_event_mutex.
8830 event
->owner
= NULL
;
8832 mutex_unlock(&child
->perf_event_mutex
);
8834 for_each_task_context_nr(ctxn
)
8835 perf_event_exit_task_context(child
, ctxn
);
8838 * The perf_event_exit_task_context calls perf_event_task
8839 * with child's task_ctx, which generates EXIT events for
8840 * child contexts and sets child->perf_event_ctxp[] to NULL.
8841 * At this point we need to send EXIT events to cpu contexts.
8843 perf_event_task(child
, NULL
, 0);
8846 static void perf_free_event(struct perf_event
*event
,
8847 struct perf_event_context
*ctx
)
8849 struct perf_event
*parent
= event
->parent
;
8851 if (WARN_ON_ONCE(!parent
))
8854 mutex_lock(&parent
->child_mutex
);
8855 list_del_init(&event
->child_list
);
8856 mutex_unlock(&parent
->child_mutex
);
8860 raw_spin_lock_irq(&ctx
->lock
);
8861 perf_group_detach(event
);
8862 list_del_event(event
, ctx
);
8863 raw_spin_unlock_irq(&ctx
->lock
);
8868 * Free an unexposed, unused context as created by inheritance by
8869 * perf_event_init_task below, used by fork() in case of fail.
8871 * Not all locks are strictly required, but take them anyway to be nice and
8872 * help out with the lockdep assertions.
8874 void perf_event_free_task(struct task_struct
*task
)
8876 struct perf_event_context
*ctx
;
8877 struct perf_event
*event
, *tmp
;
8880 for_each_task_context_nr(ctxn
) {
8881 ctx
= task
->perf_event_ctxp
[ctxn
];
8885 mutex_lock(&ctx
->mutex
);
8887 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8889 perf_free_event(event
, ctx
);
8891 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8893 perf_free_event(event
, ctx
);
8895 if (!list_empty(&ctx
->pinned_groups
) ||
8896 !list_empty(&ctx
->flexible_groups
))
8899 mutex_unlock(&ctx
->mutex
);
8905 void perf_event_delayed_put(struct task_struct
*task
)
8909 for_each_task_context_nr(ctxn
)
8910 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8913 struct perf_event
*perf_event_get(unsigned int fd
)
8917 struct perf_event
*event
;
8919 err
= perf_fget_light(fd
, &f
);
8921 return ERR_PTR(err
);
8923 event
= f
.file
->private_data
;
8924 atomic_long_inc(&event
->refcount
);
8930 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
8933 return ERR_PTR(-EINVAL
);
8935 return &event
->attr
;
8939 * inherit a event from parent task to child task:
8941 static struct perf_event
*
8942 inherit_event(struct perf_event
*parent_event
,
8943 struct task_struct
*parent
,
8944 struct perf_event_context
*parent_ctx
,
8945 struct task_struct
*child
,
8946 struct perf_event
*group_leader
,
8947 struct perf_event_context
*child_ctx
)
8949 enum perf_event_active_state parent_state
= parent_event
->state
;
8950 struct perf_event
*child_event
;
8951 unsigned long flags
;
8954 * Instead of creating recursive hierarchies of events,
8955 * we link inherited events back to the original parent,
8956 * which has a filp for sure, which we use as the reference
8959 if (parent_event
->parent
)
8960 parent_event
= parent_event
->parent
;
8962 child_event
= perf_event_alloc(&parent_event
->attr
,
8965 group_leader
, parent_event
,
8967 if (IS_ERR(child_event
))
8970 if (is_orphaned_event(parent_event
) ||
8971 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
8972 free_event(child_event
);
8979 * Make the child state follow the state of the parent event,
8980 * not its attr.disabled bit. We hold the parent's mutex,
8981 * so we won't race with perf_event_{en, dis}able_family.
8983 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
8984 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
8986 child_event
->state
= PERF_EVENT_STATE_OFF
;
8988 if (parent_event
->attr
.freq
) {
8989 u64 sample_period
= parent_event
->hw
.sample_period
;
8990 struct hw_perf_event
*hwc
= &child_event
->hw
;
8992 hwc
->sample_period
= sample_period
;
8993 hwc
->last_period
= sample_period
;
8995 local64_set(&hwc
->period_left
, sample_period
);
8998 child_event
->ctx
= child_ctx
;
8999 child_event
->overflow_handler
= parent_event
->overflow_handler
;
9000 child_event
->overflow_handler_context
9001 = parent_event
->overflow_handler_context
;
9004 * Precalculate sample_data sizes
9006 perf_event__header_size(child_event
);
9007 perf_event__id_header_size(child_event
);
9010 * Link it up in the child's context:
9012 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
9013 add_event_to_ctx(child_event
, child_ctx
);
9014 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
9017 * Link this into the parent event's child list
9019 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
9020 mutex_lock(&parent_event
->child_mutex
);
9021 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
9022 mutex_unlock(&parent_event
->child_mutex
);
9027 static int inherit_group(struct perf_event
*parent_event
,
9028 struct task_struct
*parent
,
9029 struct perf_event_context
*parent_ctx
,
9030 struct task_struct
*child
,
9031 struct perf_event_context
*child_ctx
)
9033 struct perf_event
*leader
;
9034 struct perf_event
*sub
;
9035 struct perf_event
*child_ctr
;
9037 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9038 child
, NULL
, child_ctx
);
9040 return PTR_ERR(leader
);
9041 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9042 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9043 child
, leader
, child_ctx
);
9044 if (IS_ERR(child_ctr
))
9045 return PTR_ERR(child_ctr
);
9051 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9052 struct perf_event_context
*parent_ctx
,
9053 struct task_struct
*child
, int ctxn
,
9057 struct perf_event_context
*child_ctx
;
9059 if (!event
->attr
.inherit
) {
9064 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9067 * This is executed from the parent task context, so
9068 * inherit events that have been marked for cloning.
9069 * First allocate and initialize a context for the
9073 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9077 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9080 ret
= inherit_group(event
, parent
, parent_ctx
,
9090 * Initialize the perf_event context in task_struct
9092 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9094 struct perf_event_context
*child_ctx
, *parent_ctx
;
9095 struct perf_event_context
*cloned_ctx
;
9096 struct perf_event
*event
;
9097 struct task_struct
*parent
= current
;
9098 int inherited_all
= 1;
9099 unsigned long flags
;
9102 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9106 * If the parent's context is a clone, pin it so it won't get
9109 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9114 * No need to check if parent_ctx != NULL here; since we saw
9115 * it non-NULL earlier, the only reason for it to become NULL
9116 * is if we exit, and since we're currently in the middle of
9117 * a fork we can't be exiting at the same time.
9121 * Lock the parent list. No need to lock the child - not PID
9122 * hashed yet and not running, so nobody can access it.
9124 mutex_lock(&parent_ctx
->mutex
);
9127 * We dont have to disable NMIs - we are only looking at
9128 * the list, not manipulating it:
9130 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9131 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9132 child
, ctxn
, &inherited_all
);
9138 * We can't hold ctx->lock when iterating the ->flexible_group list due
9139 * to allocations, but we need to prevent rotation because
9140 * rotate_ctx() will change the list from interrupt context.
9142 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9143 parent_ctx
->rotate_disable
= 1;
9144 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9146 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9147 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9148 child
, ctxn
, &inherited_all
);
9153 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9154 parent_ctx
->rotate_disable
= 0;
9156 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9158 if (child_ctx
&& inherited_all
) {
9160 * Mark the child context as a clone of the parent
9161 * context, or of whatever the parent is a clone of.
9163 * Note that if the parent is a clone, the holding of
9164 * parent_ctx->lock avoids it from being uncloned.
9166 cloned_ctx
= parent_ctx
->parent_ctx
;
9168 child_ctx
->parent_ctx
= cloned_ctx
;
9169 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9171 child_ctx
->parent_ctx
= parent_ctx
;
9172 child_ctx
->parent_gen
= parent_ctx
->generation
;
9174 get_ctx(child_ctx
->parent_ctx
);
9177 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9178 mutex_unlock(&parent_ctx
->mutex
);
9180 perf_unpin_context(parent_ctx
);
9181 put_ctx(parent_ctx
);
9187 * Initialize the perf_event context in task_struct
9189 int perf_event_init_task(struct task_struct
*child
)
9193 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9194 mutex_init(&child
->perf_event_mutex
);
9195 INIT_LIST_HEAD(&child
->perf_event_list
);
9197 for_each_task_context_nr(ctxn
) {
9198 ret
= perf_event_init_context(child
, ctxn
);
9200 perf_event_free_task(child
);
9208 static void __init
perf_event_init_all_cpus(void)
9210 struct swevent_htable
*swhash
;
9213 for_each_possible_cpu(cpu
) {
9214 swhash
= &per_cpu(swevent_htable
, cpu
);
9215 mutex_init(&swhash
->hlist_mutex
);
9216 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9220 static void perf_event_init_cpu(int cpu
)
9222 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9224 mutex_lock(&swhash
->hlist_mutex
);
9225 if (swhash
->hlist_refcount
> 0) {
9226 struct swevent_hlist
*hlist
;
9228 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9230 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9232 mutex_unlock(&swhash
->hlist_mutex
);
9235 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9236 static void __perf_event_exit_context(void *__info
)
9238 struct remove_event re
= { .detach_group
= true };
9239 struct perf_event_context
*ctx
= __info
;
9242 list_for_each_entry_rcu(re
.event
, &ctx
->event_list
, event_entry
)
9243 __perf_remove_from_context(&re
);
9247 static void perf_event_exit_cpu_context(int cpu
)
9249 struct perf_event_context
*ctx
;
9253 idx
= srcu_read_lock(&pmus_srcu
);
9254 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9255 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9257 mutex_lock(&ctx
->mutex
);
9258 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9259 mutex_unlock(&ctx
->mutex
);
9261 srcu_read_unlock(&pmus_srcu
, idx
);
9264 static void perf_event_exit_cpu(int cpu
)
9266 perf_event_exit_cpu_context(cpu
);
9269 static inline void perf_event_exit_cpu(int cpu
) { }
9273 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9277 for_each_online_cpu(cpu
)
9278 perf_event_exit_cpu(cpu
);
9284 * Run the perf reboot notifier at the very last possible moment so that
9285 * the generic watchdog code runs as long as possible.
9287 static struct notifier_block perf_reboot_notifier
= {
9288 .notifier_call
= perf_reboot
,
9289 .priority
= INT_MIN
,
9293 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9295 unsigned int cpu
= (long)hcpu
;
9297 switch (action
& ~CPU_TASKS_FROZEN
) {
9299 case CPU_UP_PREPARE
:
9300 case CPU_DOWN_FAILED
:
9301 perf_event_init_cpu(cpu
);
9304 case CPU_UP_CANCELED
:
9305 case CPU_DOWN_PREPARE
:
9306 perf_event_exit_cpu(cpu
);
9315 void __init
perf_event_init(void)
9321 perf_event_init_all_cpus();
9322 init_srcu_struct(&pmus_srcu
);
9323 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9324 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9325 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9327 perf_cpu_notifier(perf_cpu_notify
);
9328 register_reboot_notifier(&perf_reboot_notifier
);
9330 ret
= init_hw_breakpoint();
9331 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9333 /* do not patch jump label more than once per second */
9334 jump_label_rate_limit(&perf_sched_events
, HZ
);
9337 * Build time assertion that we keep the data_head at the intended
9338 * location. IOW, validation we got the __reserved[] size right.
9340 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9344 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9347 struct perf_pmu_events_attr
*pmu_attr
=
9348 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9350 if (pmu_attr
->event_str
)
9351 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9356 static int __init
perf_event_sysfs_init(void)
9361 mutex_lock(&pmus_lock
);
9363 ret
= bus_register(&pmu_bus
);
9367 list_for_each_entry(pmu
, &pmus
, entry
) {
9368 if (!pmu
->name
|| pmu
->type
< 0)
9371 ret
= pmu_dev_alloc(pmu
);
9372 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9374 pmu_bus_running
= 1;
9378 mutex_unlock(&pmus_lock
);
9382 device_initcall(perf_event_sysfs_init
);
9384 #ifdef CONFIG_CGROUP_PERF
9385 static struct cgroup_subsys_state
*
9386 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9388 struct perf_cgroup
*jc
;
9390 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9392 return ERR_PTR(-ENOMEM
);
9394 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9397 return ERR_PTR(-ENOMEM
);
9403 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9405 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9407 free_percpu(jc
->info
);
9411 static int __perf_cgroup_move(void *info
)
9413 struct task_struct
*task
= info
;
9415 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9420 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
9422 struct task_struct
*task
;
9423 struct cgroup_subsys_state
*css
;
9425 cgroup_taskset_for_each(task
, css
, tset
)
9426 task_function_call(task
, __perf_cgroup_move
, task
);
9429 struct cgroup_subsys perf_event_cgrp_subsys
= {
9430 .css_alloc
= perf_cgroup_css_alloc
,
9431 .css_free
= perf_cgroup_css_free
,
9432 .attach
= perf_cgroup_attach
,
9434 #endif /* CONFIG_CGROUP_PERF */