2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
49 #include <linux/sched/clock.h>
50 #include <linux/sched/mm.h>
51 #include <linux/proc_ns.h>
52 #include <linux/mount.h>
56 #include <asm/irq_regs.h>
58 typedef int (*remote_function_f
)(void *);
60 struct remote_function_call
{
61 struct task_struct
*p
;
62 remote_function_f func
;
67 static void remote_function(void *data
)
69 struct remote_function_call
*tfc
= data
;
70 struct task_struct
*p
= tfc
->p
;
74 if (task_cpu(p
) != smp_processor_id())
78 * Now that we're on right CPU with IRQs disabled, we can test
79 * if we hit the right task without races.
82 tfc
->ret
= -ESRCH
; /* No such (running) process */
87 tfc
->ret
= tfc
->func(tfc
->info
);
91 * task_function_call - call a function on the cpu on which a task runs
92 * @p: the task to evaluate
93 * @func: the function to be called
94 * @info: the function call argument
96 * Calls the function @func when the task is currently running. This might
97 * be on the current CPU, which just calls the function directly
99 * returns: @func return value, or
100 * -ESRCH - when the process isn't running
101 * -EAGAIN - when the process moved away
104 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
106 struct remote_function_call data
= {
115 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
118 } while (ret
== -EAGAIN
);
124 * cpu_function_call - call a function on the cpu
125 * @func: the function to be called
126 * @info: the function call argument
128 * Calls the function @func on the remote cpu.
130 * returns: @func return value or -ENXIO when the cpu is offline
132 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
134 struct remote_function_call data
= {
138 .ret
= -ENXIO
, /* No such CPU */
141 smp_call_function_single(cpu
, remote_function
, &data
, 1);
146 static inline struct perf_cpu_context
*
147 __get_cpu_context(struct perf_event_context
*ctx
)
149 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
152 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
153 struct perf_event_context
*ctx
)
155 raw_spin_lock(&cpuctx
->ctx
.lock
);
157 raw_spin_lock(&ctx
->lock
);
160 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
161 struct perf_event_context
*ctx
)
164 raw_spin_unlock(&ctx
->lock
);
165 raw_spin_unlock(&cpuctx
->ctx
.lock
);
168 #define TASK_TOMBSTONE ((void *)-1L)
170 static bool is_kernel_event(struct perf_event
*event
)
172 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
176 * On task ctx scheduling...
178 * When !ctx->nr_events a task context will not be scheduled. This means
179 * we can disable the scheduler hooks (for performance) without leaving
180 * pending task ctx state.
182 * This however results in two special cases:
184 * - removing the last event from a task ctx; this is relatively straight
185 * forward and is done in __perf_remove_from_context.
187 * - adding the first event to a task ctx; this is tricky because we cannot
188 * rely on ctx->is_active and therefore cannot use event_function_call().
189 * See perf_install_in_context().
191 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
194 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
195 struct perf_event_context
*, void *);
197 struct event_function_struct
{
198 struct perf_event
*event
;
203 static int event_function(void *info
)
205 struct event_function_struct
*efs
= info
;
206 struct perf_event
*event
= efs
->event
;
207 struct perf_event_context
*ctx
= event
->ctx
;
208 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
209 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
212 WARN_ON_ONCE(!irqs_disabled());
214 perf_ctx_lock(cpuctx
, task_ctx
);
216 * Since we do the IPI call without holding ctx->lock things can have
217 * changed, double check we hit the task we set out to hit.
220 if (ctx
->task
!= current
) {
226 * We only use event_function_call() on established contexts,
227 * and event_function() is only ever called when active (or
228 * rather, we'll have bailed in task_function_call() or the
229 * above ctx->task != current test), therefore we must have
230 * ctx->is_active here.
232 WARN_ON_ONCE(!ctx
->is_active
);
234 * And since we have ctx->is_active, cpuctx->task_ctx must
237 WARN_ON_ONCE(task_ctx
!= ctx
);
239 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
242 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
244 perf_ctx_unlock(cpuctx
, task_ctx
);
249 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
251 struct perf_event_context
*ctx
= event
->ctx
;
252 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
253 struct event_function_struct efs
= {
259 if (!event
->parent
) {
261 * If this is a !child event, we must hold ctx::mutex to
262 * stabilize the the event->ctx relation. See
263 * perf_event_ctx_lock().
265 lockdep_assert_held(&ctx
->mutex
);
269 cpu_function_call(event
->cpu
, event_function
, &efs
);
273 if (task
== TASK_TOMBSTONE
)
277 if (!task_function_call(task
, event_function
, &efs
))
280 raw_spin_lock_irq(&ctx
->lock
);
282 * Reload the task pointer, it might have been changed by
283 * a concurrent perf_event_context_sched_out().
286 if (task
== TASK_TOMBSTONE
) {
287 raw_spin_unlock_irq(&ctx
->lock
);
290 if (ctx
->is_active
) {
291 raw_spin_unlock_irq(&ctx
->lock
);
294 func(event
, NULL
, ctx
, data
);
295 raw_spin_unlock_irq(&ctx
->lock
);
299 * Similar to event_function_call() + event_function(), but hard assumes IRQs
300 * are already disabled and we're on the right CPU.
302 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
304 struct perf_event_context
*ctx
= event
->ctx
;
305 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
306 struct task_struct
*task
= READ_ONCE(ctx
->task
);
307 struct perf_event_context
*task_ctx
= NULL
;
309 WARN_ON_ONCE(!irqs_disabled());
312 if (task
== TASK_TOMBSTONE
)
318 perf_ctx_lock(cpuctx
, task_ctx
);
321 if (task
== TASK_TOMBSTONE
)
326 * We must be either inactive or active and the right task,
327 * otherwise we're screwed, since we cannot IPI to somewhere
330 if (ctx
->is_active
) {
331 if (WARN_ON_ONCE(task
!= current
))
334 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
338 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
341 func(event
, cpuctx
, ctx
, data
);
343 perf_ctx_unlock(cpuctx
, task_ctx
);
346 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
347 PERF_FLAG_FD_OUTPUT |\
348 PERF_FLAG_PID_CGROUP |\
349 PERF_FLAG_FD_CLOEXEC)
352 * branch priv levels that need permission checks
354 #define PERF_SAMPLE_BRANCH_PERM_PLM \
355 (PERF_SAMPLE_BRANCH_KERNEL |\
356 PERF_SAMPLE_BRANCH_HV)
359 EVENT_FLEXIBLE
= 0x1,
362 /* see ctx_resched() for details */
364 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
368 * perf_sched_events : >0 events exist
369 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
372 static void perf_sched_delayed(struct work_struct
*work
);
373 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
374 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
375 static DEFINE_MUTEX(perf_sched_mutex
);
376 static atomic_t perf_sched_count
;
378 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
379 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
380 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
382 static atomic_t nr_mmap_events __read_mostly
;
383 static atomic_t nr_comm_events __read_mostly
;
384 static atomic_t nr_namespaces_events __read_mostly
;
385 static atomic_t nr_task_events __read_mostly
;
386 static atomic_t nr_freq_events __read_mostly
;
387 static atomic_t nr_switch_events __read_mostly
;
389 static LIST_HEAD(pmus
);
390 static DEFINE_MUTEX(pmus_lock
);
391 static struct srcu_struct pmus_srcu
;
392 static cpumask_var_t perf_online_mask
;
395 * perf event paranoia level:
396 * -1 - not paranoid at all
397 * 0 - disallow raw tracepoint access for unpriv
398 * 1 - disallow cpu events for unpriv
399 * 2 - disallow kernel profiling for unpriv
400 * 3 - disallow all unpriv perf event use
402 #ifdef CONFIG_SECURITY_PERF_EVENTS_RESTRICT
403 int sysctl_perf_event_paranoid __read_mostly
= 3;
405 int sysctl_perf_event_paranoid __read_mostly
= 2;
408 /* Minimum for 512 kiB + 1 user control page */
409 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
412 * max perf event sample rate
414 #define DEFAULT_MAX_SAMPLE_RATE 100000
415 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
416 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
418 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
420 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
421 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
423 static int perf_sample_allowed_ns __read_mostly
=
424 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
426 static void update_perf_cpu_limits(void)
428 u64 tmp
= perf_sample_period_ns
;
430 tmp
*= sysctl_perf_cpu_time_max_percent
;
431 tmp
= div_u64(tmp
, 100);
435 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
438 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
440 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
441 void __user
*buffer
, size_t *lenp
,
444 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
450 * If throttling is disabled don't allow the write:
452 if (sysctl_perf_cpu_time_max_percent
== 100 ||
453 sysctl_perf_cpu_time_max_percent
== 0)
456 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
457 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
458 update_perf_cpu_limits();
463 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
465 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
466 void __user
*buffer
, size_t *lenp
,
469 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
474 if (sysctl_perf_cpu_time_max_percent
== 100 ||
475 sysctl_perf_cpu_time_max_percent
== 0) {
477 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
478 WRITE_ONCE(perf_sample_allowed_ns
, 0);
480 update_perf_cpu_limits();
487 * perf samples are done in some very critical code paths (NMIs).
488 * If they take too much CPU time, the system can lock up and not
489 * get any real work done. This will drop the sample rate when
490 * we detect that events are taking too long.
492 #define NR_ACCUMULATED_SAMPLES 128
493 static DEFINE_PER_CPU(u64
, running_sample_length
);
495 static u64 __report_avg
;
496 static u64 __report_allowed
;
498 static void perf_duration_warn(struct irq_work
*w
)
500 printk_ratelimited(KERN_INFO
501 "perf: interrupt took too long (%lld > %lld), lowering "
502 "kernel.perf_event_max_sample_rate to %d\n",
503 __report_avg
, __report_allowed
,
504 sysctl_perf_event_sample_rate
);
507 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
509 void perf_sample_event_took(u64 sample_len_ns
)
511 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
519 /* Decay the counter by 1 average sample. */
520 running_len
= __this_cpu_read(running_sample_length
);
521 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
522 running_len
+= sample_len_ns
;
523 __this_cpu_write(running_sample_length
, running_len
);
526 * Note: this will be biased artifically low until we have
527 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
528 * from having to maintain a count.
530 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
531 if (avg_len
<= max_len
)
534 __report_avg
= avg_len
;
535 __report_allowed
= max_len
;
538 * Compute a throttle threshold 25% below the current duration.
540 avg_len
+= avg_len
/ 4;
541 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
547 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
548 WRITE_ONCE(max_samples_per_tick
, max
);
550 sysctl_perf_event_sample_rate
= max
* HZ
;
551 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
553 if (!irq_work_queue(&perf_duration_work
)) {
554 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
555 "kernel.perf_event_max_sample_rate to %d\n",
556 __report_avg
, __report_allowed
,
557 sysctl_perf_event_sample_rate
);
561 static atomic64_t perf_event_id
;
563 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
564 enum event_type_t event_type
);
566 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
567 enum event_type_t event_type
,
568 struct task_struct
*task
);
570 static void update_context_time(struct perf_event_context
*ctx
);
571 static u64
perf_event_time(struct perf_event
*event
);
573 void __weak
perf_event_print_debug(void) { }
575 extern __weak
const char *perf_pmu_name(void)
580 static inline u64
perf_clock(void)
582 return local_clock();
585 static inline u64
perf_event_clock(struct perf_event
*event
)
587 return event
->clock();
590 #ifdef CONFIG_CGROUP_PERF
593 perf_cgroup_match(struct perf_event
*event
)
595 struct perf_event_context
*ctx
= event
->ctx
;
596 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
598 /* @event doesn't care about cgroup */
602 /* wants specific cgroup scope but @cpuctx isn't associated with any */
607 * Cgroup scoping is recursive. An event enabled for a cgroup is
608 * also enabled for all its descendant cgroups. If @cpuctx's
609 * cgroup is a descendant of @event's (the test covers identity
610 * case), it's a match.
612 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
613 event
->cgrp
->css
.cgroup
);
616 static inline void perf_detach_cgroup(struct perf_event
*event
)
618 css_put(&event
->cgrp
->css
);
622 static inline int is_cgroup_event(struct perf_event
*event
)
624 return event
->cgrp
!= NULL
;
627 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
629 struct perf_cgroup_info
*t
;
631 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
635 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
637 struct perf_cgroup_info
*info
;
642 info
= this_cpu_ptr(cgrp
->info
);
644 info
->time
+= now
- info
->timestamp
;
645 info
->timestamp
= now
;
648 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
650 struct perf_cgroup
*cgrp
= cpuctx
->cgrp
;
651 struct cgroup_subsys_state
*css
;
654 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
655 cgrp
= container_of(css
, struct perf_cgroup
, css
);
656 __update_cgrp_time(cgrp
);
661 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
663 struct perf_cgroup
*cgrp
;
666 * ensure we access cgroup data only when needed and
667 * when we know the cgroup is pinned (css_get)
669 if (!is_cgroup_event(event
))
672 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
674 * Do not update time when cgroup is not active
676 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
677 __update_cgrp_time(event
->cgrp
);
681 perf_cgroup_set_timestamp(struct task_struct
*task
,
682 struct perf_event_context
*ctx
)
684 struct perf_cgroup
*cgrp
;
685 struct perf_cgroup_info
*info
;
686 struct cgroup_subsys_state
*css
;
689 * ctx->lock held by caller
690 * ensure we do not access cgroup data
691 * unless we have the cgroup pinned (css_get)
693 if (!task
|| !ctx
->nr_cgroups
)
696 cgrp
= perf_cgroup_from_task(task
, ctx
);
698 for (css
= &cgrp
->css
; css
; css
= css
->parent
) {
699 cgrp
= container_of(css
, struct perf_cgroup
, css
);
700 info
= this_cpu_ptr(cgrp
->info
);
701 info
->timestamp
= ctx
->timestamp
;
705 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
707 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
708 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
711 * reschedule events based on the cgroup constraint of task.
713 * mode SWOUT : schedule out everything
714 * mode SWIN : schedule in based on cgroup for next
716 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
718 struct perf_cpu_context
*cpuctx
;
719 struct list_head
*list
;
723 * Disable interrupts and preemption to avoid this CPU's
724 * cgrp_cpuctx_entry to change under us.
726 local_irq_save(flags
);
728 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
729 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
730 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
732 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
733 perf_pmu_disable(cpuctx
->ctx
.pmu
);
735 if (mode
& PERF_CGROUP_SWOUT
) {
736 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
738 * must not be done before ctxswout due
739 * to event_filter_match() in event_sched_out()
744 if (mode
& PERF_CGROUP_SWIN
) {
745 WARN_ON_ONCE(cpuctx
->cgrp
);
747 * set cgrp before ctxsw in to allow
748 * event_filter_match() to not have to pass
750 * we pass the cpuctx->ctx to perf_cgroup_from_task()
751 * because cgorup events are only per-cpu
753 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
755 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
757 perf_pmu_enable(cpuctx
->ctx
.pmu
);
758 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
761 local_irq_restore(flags
);
764 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
765 struct task_struct
*next
)
767 struct perf_cgroup
*cgrp1
;
768 struct perf_cgroup
*cgrp2
= NULL
;
772 * we come here when we know perf_cgroup_events > 0
773 * we do not need to pass the ctx here because we know
774 * we are holding the rcu lock
776 cgrp1
= perf_cgroup_from_task(task
, NULL
);
777 cgrp2
= perf_cgroup_from_task(next
, NULL
);
780 * only schedule out current cgroup events if we know
781 * that we are switching to a different cgroup. Otherwise,
782 * do no touch the cgroup events.
785 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
790 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
791 struct task_struct
*task
)
793 struct perf_cgroup
*cgrp1
;
794 struct perf_cgroup
*cgrp2
= NULL
;
798 * we come here when we know perf_cgroup_events > 0
799 * we do not need to pass the ctx here because we know
800 * we are holding the rcu lock
802 cgrp1
= perf_cgroup_from_task(task
, NULL
);
803 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
806 * only need to schedule in cgroup events if we are changing
807 * cgroup during ctxsw. Cgroup events were not scheduled
808 * out of ctxsw out if that was not the case.
811 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
816 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
817 struct perf_event_attr
*attr
,
818 struct perf_event
*group_leader
)
820 struct perf_cgroup
*cgrp
;
821 struct cgroup_subsys_state
*css
;
822 struct fd f
= fdget(fd
);
828 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
829 &perf_event_cgrp_subsys
);
835 cgrp
= container_of(css
, struct perf_cgroup
, css
);
839 * all events in a group must monitor
840 * the same cgroup because a task belongs
841 * to only one perf cgroup at a time
843 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
844 perf_detach_cgroup(event
);
853 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
855 struct perf_cgroup_info
*t
;
856 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
857 event
->shadow_ctx_time
= now
- t
->timestamp
;
861 perf_cgroup_defer_enabled(struct perf_event
*event
)
864 * when the current task's perf cgroup does not match
865 * the event's, we need to remember to call the
866 * perf_mark_enable() function the first time a task with
867 * a matching perf cgroup is scheduled in.
869 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
870 event
->cgrp_defer_enabled
= 1;
874 perf_cgroup_mark_enabled(struct perf_event
*event
,
875 struct perf_event_context
*ctx
)
877 struct perf_event
*sub
;
878 u64 tstamp
= perf_event_time(event
);
880 if (!event
->cgrp_defer_enabled
)
883 event
->cgrp_defer_enabled
= 0;
885 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
886 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
887 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
888 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
889 sub
->cgrp_defer_enabled
= 0;
895 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
896 * cleared when last cgroup event is removed.
899 list_update_cgroup_event(struct perf_event
*event
,
900 struct perf_event_context
*ctx
, bool add
)
902 struct perf_cpu_context
*cpuctx
;
903 struct list_head
*cpuctx_entry
;
905 if (!is_cgroup_event(event
))
909 * Because cgroup events are always per-cpu events,
910 * this will always be called from the right CPU.
912 cpuctx
= __get_cpu_context(ctx
);
915 * Since setting cpuctx->cgrp is conditional on the current @cgrp
916 * matching the event's cgroup, we must do this for every new event,
917 * because if the first would mismatch, the second would not try again
918 * and we would leave cpuctx->cgrp unset.
920 if (add
&& !cpuctx
->cgrp
) {
921 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
923 if (cgroup_is_descendant(cgrp
->css
.cgroup
, event
->cgrp
->css
.cgroup
))
927 if (add
&& ctx
->nr_cgroups
++)
929 else if (!add
&& --ctx
->nr_cgroups
)
932 /* no cgroup running */
936 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
938 list_add(cpuctx_entry
, this_cpu_ptr(&cgrp_cpuctx_list
));
940 list_del(cpuctx_entry
);
943 #else /* !CONFIG_CGROUP_PERF */
946 perf_cgroup_match(struct perf_event
*event
)
951 static inline void perf_detach_cgroup(struct perf_event
*event
)
954 static inline int is_cgroup_event(struct perf_event
*event
)
959 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
963 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
967 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
968 struct task_struct
*next
)
972 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
973 struct task_struct
*task
)
977 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
978 struct perf_event_attr
*attr
,
979 struct perf_event
*group_leader
)
985 perf_cgroup_set_timestamp(struct task_struct
*task
,
986 struct perf_event_context
*ctx
)
991 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
996 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
1000 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
1006 perf_cgroup_defer_enabled(struct perf_event
*event
)
1011 perf_cgroup_mark_enabled(struct perf_event
*event
,
1012 struct perf_event_context
*ctx
)
1017 list_update_cgroup_event(struct perf_event
*event
,
1018 struct perf_event_context
*ctx
, bool add
)
1025 * set default to be dependent on timer tick just
1026 * like original code
1028 #define PERF_CPU_HRTIMER (1000 / HZ)
1030 * function must be called with interrupts disabled
1032 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1034 struct perf_cpu_context
*cpuctx
;
1037 WARN_ON(!irqs_disabled());
1039 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1040 rotations
= perf_rotate_context(cpuctx
);
1042 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1044 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1046 cpuctx
->hrtimer_active
= 0;
1047 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1049 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1052 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1054 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1055 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1058 /* no multiplexing needed for SW PMU */
1059 if (pmu
->task_ctx_nr
== perf_sw_context
)
1063 * check default is sane, if not set then force to
1064 * default interval (1/tick)
1066 interval
= pmu
->hrtimer_interval_ms
;
1068 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1070 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1072 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1073 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1074 timer
->function
= perf_mux_hrtimer_handler
;
1077 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1079 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1080 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1081 unsigned long flags
;
1083 /* not for SW PMU */
1084 if (pmu
->task_ctx_nr
== perf_sw_context
)
1087 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1088 if (!cpuctx
->hrtimer_active
) {
1089 cpuctx
->hrtimer_active
= 1;
1090 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1091 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1093 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1098 void perf_pmu_disable(struct pmu
*pmu
)
1100 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1102 pmu
->pmu_disable(pmu
);
1105 void perf_pmu_enable(struct pmu
*pmu
)
1107 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1109 pmu
->pmu_enable(pmu
);
1112 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1115 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1116 * perf_event_task_tick() are fully serialized because they're strictly cpu
1117 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1118 * disabled, while perf_event_task_tick is called from IRQ context.
1120 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1122 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1124 WARN_ON(!irqs_disabled());
1126 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1128 list_add(&ctx
->active_ctx_list
, head
);
1131 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1133 WARN_ON(!irqs_disabled());
1135 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1137 list_del_init(&ctx
->active_ctx_list
);
1140 static void get_ctx(struct perf_event_context
*ctx
)
1142 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1145 static void free_ctx(struct rcu_head
*head
)
1147 struct perf_event_context
*ctx
;
1149 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1150 kfree(ctx
->task_ctx_data
);
1154 static void put_ctx(struct perf_event_context
*ctx
)
1156 if (atomic_dec_and_test(&ctx
->refcount
)) {
1157 if (ctx
->parent_ctx
)
1158 put_ctx(ctx
->parent_ctx
);
1159 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1160 put_task_struct(ctx
->task
);
1161 call_rcu(&ctx
->rcu_head
, free_ctx
);
1166 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1167 * perf_pmu_migrate_context() we need some magic.
1169 * Those places that change perf_event::ctx will hold both
1170 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1172 * Lock ordering is by mutex address. There are two other sites where
1173 * perf_event_context::mutex nests and those are:
1175 * - perf_event_exit_task_context() [ child , 0 ]
1176 * perf_event_exit_event()
1177 * put_event() [ parent, 1 ]
1179 * - perf_event_init_context() [ parent, 0 ]
1180 * inherit_task_group()
1183 * perf_event_alloc()
1185 * perf_try_init_event() [ child , 1 ]
1187 * While it appears there is an obvious deadlock here -- the parent and child
1188 * nesting levels are inverted between the two. This is in fact safe because
1189 * life-time rules separate them. That is an exiting task cannot fork, and a
1190 * spawning task cannot (yet) exit.
1192 * But remember that that these are parent<->child context relations, and
1193 * migration does not affect children, therefore these two orderings should not
1196 * The change in perf_event::ctx does not affect children (as claimed above)
1197 * because the sys_perf_event_open() case will install a new event and break
1198 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1199 * concerned with cpuctx and that doesn't have children.
1201 * The places that change perf_event::ctx will issue:
1203 * perf_remove_from_context();
1204 * synchronize_rcu();
1205 * perf_install_in_context();
1207 * to affect the change. The remove_from_context() + synchronize_rcu() should
1208 * quiesce the event, after which we can install it in the new location. This
1209 * means that only external vectors (perf_fops, prctl) can perturb the event
1210 * while in transit. Therefore all such accessors should also acquire
1211 * perf_event_context::mutex to serialize against this.
1213 * However; because event->ctx can change while we're waiting to acquire
1214 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1219 * task_struct::perf_event_mutex
1220 * perf_event_context::mutex
1221 * perf_event::child_mutex;
1222 * perf_event_context::lock
1223 * perf_event::mmap_mutex
1226 static struct perf_event_context
*
1227 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1229 struct perf_event_context
*ctx
;
1233 ctx
= ACCESS_ONCE(event
->ctx
);
1234 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1240 mutex_lock_nested(&ctx
->mutex
, nesting
);
1241 if (event
->ctx
!= ctx
) {
1242 mutex_unlock(&ctx
->mutex
);
1250 static inline struct perf_event_context
*
1251 perf_event_ctx_lock(struct perf_event
*event
)
1253 return perf_event_ctx_lock_nested(event
, 0);
1256 static void perf_event_ctx_unlock(struct perf_event
*event
,
1257 struct perf_event_context
*ctx
)
1259 mutex_unlock(&ctx
->mutex
);
1264 * This must be done under the ctx->lock, such as to serialize against
1265 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1266 * calling scheduler related locks and ctx->lock nests inside those.
1268 static __must_check
struct perf_event_context
*
1269 unclone_ctx(struct perf_event_context
*ctx
)
1271 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1273 lockdep_assert_held(&ctx
->lock
);
1276 ctx
->parent_ctx
= NULL
;
1282 static u32
perf_event_pid_type(struct perf_event
*event
, struct task_struct
*p
,
1287 * only top level events have the pid namespace they were created in
1290 event
= event
->parent
;
1292 nr
= __task_pid_nr_ns(p
, type
, event
->ns
);
1293 /* avoid -1 if it is idle thread or runs in another ns */
1294 if (!nr
&& !pid_alive(p
))
1299 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1301 return perf_event_pid_type(event
, p
, __PIDTYPE_TGID
);
1304 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1306 return perf_event_pid_type(event
, p
, PIDTYPE_PID
);
1310 * If we inherit events we want to return the parent event id
1313 static u64
primary_event_id(struct perf_event
*event
)
1318 id
= event
->parent
->id
;
1324 * Get the perf_event_context for a task and lock it.
1326 * This has to cope with with the fact that until it is locked,
1327 * the context could get moved to another task.
1329 static struct perf_event_context
*
1330 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1332 struct perf_event_context
*ctx
;
1336 * One of the few rules of preemptible RCU is that one cannot do
1337 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1338 * part of the read side critical section was irqs-enabled -- see
1339 * rcu_read_unlock_special().
1341 * Since ctx->lock nests under rq->lock we must ensure the entire read
1342 * side critical section has interrupts disabled.
1344 local_irq_save(*flags
);
1346 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1349 * If this context is a clone of another, it might
1350 * get swapped for another underneath us by
1351 * perf_event_task_sched_out, though the
1352 * rcu_read_lock() protects us from any context
1353 * getting freed. Lock the context and check if it
1354 * got swapped before we could get the lock, and retry
1355 * if so. If we locked the right context, then it
1356 * can't get swapped on us any more.
1358 raw_spin_lock(&ctx
->lock
);
1359 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1360 raw_spin_unlock(&ctx
->lock
);
1362 local_irq_restore(*flags
);
1366 if (ctx
->task
== TASK_TOMBSTONE
||
1367 !atomic_inc_not_zero(&ctx
->refcount
)) {
1368 raw_spin_unlock(&ctx
->lock
);
1371 WARN_ON_ONCE(ctx
->task
!= task
);
1376 local_irq_restore(*flags
);
1381 * Get the context for a task and increment its pin_count so it
1382 * can't get swapped to another task. This also increments its
1383 * reference count so that the context can't get freed.
1385 static struct perf_event_context
*
1386 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1388 struct perf_event_context
*ctx
;
1389 unsigned long flags
;
1391 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1394 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1399 static void perf_unpin_context(struct perf_event_context
*ctx
)
1401 unsigned long flags
;
1403 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1405 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1409 * Update the record of the current time in a context.
1411 static void update_context_time(struct perf_event_context
*ctx
)
1413 u64 now
= perf_clock();
1415 ctx
->time
+= now
- ctx
->timestamp
;
1416 ctx
->timestamp
= now
;
1419 static u64
perf_event_time(struct perf_event
*event
)
1421 struct perf_event_context
*ctx
= event
->ctx
;
1423 if (is_cgroup_event(event
))
1424 return perf_cgroup_event_time(event
);
1426 return ctx
? ctx
->time
: 0;
1430 * Update the total_time_enabled and total_time_running fields for a event.
1432 static void update_event_times(struct perf_event
*event
)
1434 struct perf_event_context
*ctx
= event
->ctx
;
1437 lockdep_assert_held(&ctx
->lock
);
1439 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1440 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1444 * in cgroup mode, time_enabled represents
1445 * the time the event was enabled AND active
1446 * tasks were in the monitored cgroup. This is
1447 * independent of the activity of the context as
1448 * there may be a mix of cgroup and non-cgroup events.
1450 * That is why we treat cgroup events differently
1453 if (is_cgroup_event(event
))
1454 run_end
= perf_cgroup_event_time(event
);
1455 else if (ctx
->is_active
)
1456 run_end
= ctx
->time
;
1458 run_end
= event
->tstamp_stopped
;
1460 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1462 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1463 run_end
= event
->tstamp_stopped
;
1465 run_end
= perf_event_time(event
);
1467 event
->total_time_running
= run_end
- event
->tstamp_running
;
1472 * Update total_time_enabled and total_time_running for all events in a group.
1474 static void update_group_times(struct perf_event
*leader
)
1476 struct perf_event
*event
;
1478 update_event_times(leader
);
1479 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1480 update_event_times(event
);
1483 static enum event_type_t
get_event_type(struct perf_event
*event
)
1485 struct perf_event_context
*ctx
= event
->ctx
;
1486 enum event_type_t event_type
;
1488 lockdep_assert_held(&ctx
->lock
);
1491 * It's 'group type', really, because if our group leader is
1492 * pinned, so are we.
1494 if (event
->group_leader
!= event
)
1495 event
= event
->group_leader
;
1497 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1499 event_type
|= EVENT_CPU
;
1504 static struct list_head
*
1505 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1507 if (event
->attr
.pinned
)
1508 return &ctx
->pinned_groups
;
1510 return &ctx
->flexible_groups
;
1514 * Add a event from the lists for its context.
1515 * Must be called with ctx->mutex and ctx->lock held.
1518 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1520 lockdep_assert_held(&ctx
->lock
);
1522 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1523 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1526 * If we're a stand alone event or group leader, we go to the context
1527 * list, group events are kept attached to the group so that
1528 * perf_group_detach can, at all times, locate all siblings.
1530 if (event
->group_leader
== event
) {
1531 struct list_head
*list
;
1533 event
->group_caps
= event
->event_caps
;
1535 list
= ctx_group_list(event
, ctx
);
1536 list_add_tail(&event
->group_entry
, list
);
1539 list_update_cgroup_event(event
, ctx
, true);
1541 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1543 if (event
->attr
.inherit_stat
)
1550 * Initialize event state based on the perf_event_attr::disabled.
1552 static inline void perf_event__state_init(struct perf_event
*event
)
1554 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1555 PERF_EVENT_STATE_INACTIVE
;
1558 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1560 int entry
= sizeof(u64
); /* value */
1564 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1565 size
+= sizeof(u64
);
1567 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1568 size
+= sizeof(u64
);
1570 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1571 entry
+= sizeof(u64
);
1573 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1575 size
+= sizeof(u64
);
1579 event
->read_size
= size
;
1582 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1584 struct perf_sample_data
*data
;
1587 if (sample_type
& PERF_SAMPLE_IP
)
1588 size
+= sizeof(data
->ip
);
1590 if (sample_type
& PERF_SAMPLE_ADDR
)
1591 size
+= sizeof(data
->addr
);
1593 if (sample_type
& PERF_SAMPLE_PERIOD
)
1594 size
+= sizeof(data
->period
);
1596 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1597 size
+= sizeof(data
->weight
);
1599 if (sample_type
& PERF_SAMPLE_READ
)
1600 size
+= event
->read_size
;
1602 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1603 size
+= sizeof(data
->data_src
.val
);
1605 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1606 size
+= sizeof(data
->txn
);
1608 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
1609 size
+= sizeof(data
->phys_addr
);
1611 event
->header_size
= size
;
1615 * Called at perf_event creation and when events are attached/detached from a
1618 static void perf_event__header_size(struct perf_event
*event
)
1620 __perf_event_read_size(event
,
1621 event
->group_leader
->nr_siblings
);
1622 __perf_event_header_size(event
, event
->attr
.sample_type
);
1625 static void perf_event__id_header_size(struct perf_event
*event
)
1627 struct perf_sample_data
*data
;
1628 u64 sample_type
= event
->attr
.sample_type
;
1631 if (sample_type
& PERF_SAMPLE_TID
)
1632 size
+= sizeof(data
->tid_entry
);
1634 if (sample_type
& PERF_SAMPLE_TIME
)
1635 size
+= sizeof(data
->time
);
1637 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1638 size
+= sizeof(data
->id
);
1640 if (sample_type
& PERF_SAMPLE_ID
)
1641 size
+= sizeof(data
->id
);
1643 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1644 size
+= sizeof(data
->stream_id
);
1646 if (sample_type
& PERF_SAMPLE_CPU
)
1647 size
+= sizeof(data
->cpu_entry
);
1649 event
->id_header_size
= size
;
1652 static bool perf_event_validate_size(struct perf_event
*event
)
1655 * The values computed here will be over-written when we actually
1658 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1659 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1660 perf_event__id_header_size(event
);
1663 * Sum the lot; should not exceed the 64k limit we have on records.
1664 * Conservative limit to allow for callchains and other variable fields.
1666 if (event
->read_size
+ event
->header_size
+
1667 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1673 static void perf_group_attach(struct perf_event
*event
)
1675 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1677 lockdep_assert_held(&event
->ctx
->lock
);
1680 * We can have double attach due to group movement in perf_event_open.
1682 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1685 event
->attach_state
|= PERF_ATTACH_GROUP
;
1687 if (group_leader
== event
)
1690 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1692 group_leader
->group_caps
&= event
->event_caps
;
1694 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1695 group_leader
->nr_siblings
++;
1697 perf_event__header_size(group_leader
);
1699 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1700 perf_event__header_size(pos
);
1704 * Remove a event from the lists for its context.
1705 * Must be called with ctx->mutex and ctx->lock held.
1708 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1710 WARN_ON_ONCE(event
->ctx
!= ctx
);
1711 lockdep_assert_held(&ctx
->lock
);
1714 * We can have double detach due to exit/hot-unplug + close.
1716 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1719 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1721 list_update_cgroup_event(event
, ctx
, false);
1724 if (event
->attr
.inherit_stat
)
1727 list_del_rcu(&event
->event_entry
);
1729 if (event
->group_leader
== event
)
1730 list_del_init(&event
->group_entry
);
1732 update_group_times(event
);
1735 * If event was in error state, then keep it
1736 * that way, otherwise bogus counts will be
1737 * returned on read(). The only way to get out
1738 * of error state is by explicit re-enabling
1741 if (event
->state
> PERF_EVENT_STATE_OFF
)
1742 event
->state
= PERF_EVENT_STATE_OFF
;
1747 static void perf_group_detach(struct perf_event
*event
)
1749 struct perf_event
*sibling
, *tmp
;
1750 struct list_head
*list
= NULL
;
1752 lockdep_assert_held(&event
->ctx
->lock
);
1755 * We can have double detach due to exit/hot-unplug + close.
1757 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1760 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1763 * If this is a sibling, remove it from its group.
1765 if (event
->group_leader
!= event
) {
1766 list_del_init(&event
->group_entry
);
1767 event
->group_leader
->nr_siblings
--;
1771 if (!list_empty(&event
->group_entry
))
1772 list
= &event
->group_entry
;
1775 * If this was a group event with sibling events then
1776 * upgrade the siblings to singleton events by adding them
1777 * to whatever list we are on.
1779 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1781 list_move_tail(&sibling
->group_entry
, list
);
1782 sibling
->group_leader
= sibling
;
1784 /* Inherit group flags from the previous leader */
1785 sibling
->group_caps
= event
->group_caps
;
1787 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1791 perf_event__header_size(event
->group_leader
);
1793 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1794 perf_event__header_size(tmp
);
1797 static bool is_orphaned_event(struct perf_event
*event
)
1799 return event
->state
== PERF_EVENT_STATE_DEAD
;
1802 static inline int __pmu_filter_match(struct perf_event
*event
)
1804 struct pmu
*pmu
= event
->pmu
;
1805 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1809 * Check whether we should attempt to schedule an event group based on
1810 * PMU-specific filtering. An event group can consist of HW and SW events,
1811 * potentially with a SW leader, so we must check all the filters, to
1812 * determine whether a group is schedulable:
1814 static inline int pmu_filter_match(struct perf_event
*event
)
1816 struct perf_event
*child
;
1818 if (!__pmu_filter_match(event
))
1821 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1822 if (!__pmu_filter_match(child
))
1830 event_filter_match(struct perf_event
*event
)
1832 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1833 perf_cgroup_match(event
) && pmu_filter_match(event
);
1837 event_sched_out(struct perf_event
*event
,
1838 struct perf_cpu_context
*cpuctx
,
1839 struct perf_event_context
*ctx
)
1841 u64 tstamp
= perf_event_time(event
);
1844 WARN_ON_ONCE(event
->ctx
!= ctx
);
1845 lockdep_assert_held(&ctx
->lock
);
1848 * An event which could not be activated because of
1849 * filter mismatch still needs to have its timings
1850 * maintained, otherwise bogus information is return
1851 * via read() for time_enabled, time_running:
1853 if (event
->state
== PERF_EVENT_STATE_INACTIVE
&&
1854 !event_filter_match(event
)) {
1855 delta
= tstamp
- event
->tstamp_stopped
;
1856 event
->tstamp_running
+= delta
;
1857 event
->tstamp_stopped
= tstamp
;
1860 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1863 perf_pmu_disable(event
->pmu
);
1865 event
->tstamp_stopped
= tstamp
;
1866 event
->pmu
->del(event
, 0);
1868 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1869 if (event
->pending_disable
) {
1870 event
->pending_disable
= 0;
1871 event
->state
= PERF_EVENT_STATE_OFF
;
1874 if (!is_software_event(event
))
1875 cpuctx
->active_oncpu
--;
1876 if (!--ctx
->nr_active
)
1877 perf_event_ctx_deactivate(ctx
);
1878 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1880 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1881 cpuctx
->exclusive
= 0;
1883 perf_pmu_enable(event
->pmu
);
1887 group_sched_out(struct perf_event
*group_event
,
1888 struct perf_cpu_context
*cpuctx
,
1889 struct perf_event_context
*ctx
)
1891 struct perf_event
*event
;
1892 int state
= group_event
->state
;
1894 perf_pmu_disable(ctx
->pmu
);
1896 event_sched_out(group_event
, cpuctx
, ctx
);
1899 * Schedule out siblings (if any):
1901 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1902 event_sched_out(event
, cpuctx
, ctx
);
1904 perf_pmu_enable(ctx
->pmu
);
1906 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1907 cpuctx
->exclusive
= 0;
1910 #define DETACH_GROUP 0x01UL
1913 * Cross CPU call to remove a performance event
1915 * We disable the event on the hardware level first. After that we
1916 * remove it from the context list.
1919 __perf_remove_from_context(struct perf_event
*event
,
1920 struct perf_cpu_context
*cpuctx
,
1921 struct perf_event_context
*ctx
,
1924 unsigned long flags
= (unsigned long)info
;
1926 event_sched_out(event
, cpuctx
, ctx
);
1927 if (flags
& DETACH_GROUP
)
1928 perf_group_detach(event
);
1929 list_del_event(event
, ctx
);
1931 if (!ctx
->nr_events
&& ctx
->is_active
) {
1934 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1935 cpuctx
->task_ctx
= NULL
;
1941 * Remove the event from a task's (or a CPU's) list of events.
1943 * If event->ctx is a cloned context, callers must make sure that
1944 * every task struct that event->ctx->task could possibly point to
1945 * remains valid. This is OK when called from perf_release since
1946 * that only calls us on the top-level context, which can't be a clone.
1947 * When called from perf_event_exit_task, it's OK because the
1948 * context has been detached from its task.
1950 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1952 struct perf_event_context
*ctx
= event
->ctx
;
1954 lockdep_assert_held(&ctx
->mutex
);
1956 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1959 * The above event_function_call() can NO-OP when it hits
1960 * TASK_TOMBSTONE. In that case we must already have been detached
1961 * from the context (by perf_event_exit_event()) but the grouping
1962 * might still be in-tact.
1964 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1965 if ((flags
& DETACH_GROUP
) &&
1966 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
1968 * Since in that case we cannot possibly be scheduled, simply
1971 raw_spin_lock_irq(&ctx
->lock
);
1972 perf_group_detach(event
);
1973 raw_spin_unlock_irq(&ctx
->lock
);
1978 * Cross CPU call to disable a performance event
1980 static void __perf_event_disable(struct perf_event
*event
,
1981 struct perf_cpu_context
*cpuctx
,
1982 struct perf_event_context
*ctx
,
1985 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1988 update_context_time(ctx
);
1989 update_cgrp_time_from_event(event
);
1990 update_group_times(event
);
1991 if (event
== event
->group_leader
)
1992 group_sched_out(event
, cpuctx
, ctx
);
1994 event_sched_out(event
, cpuctx
, ctx
);
1995 event
->state
= PERF_EVENT_STATE_OFF
;
2001 * If event->ctx is a cloned context, callers must make sure that
2002 * every task struct that event->ctx->task could possibly point to
2003 * remains valid. This condition is satisifed when called through
2004 * perf_event_for_each_child or perf_event_for_each because they
2005 * hold the top-level event's child_mutex, so any descendant that
2006 * goes to exit will block in perf_event_exit_event().
2008 * When called from perf_pending_event it's OK because event->ctx
2009 * is the current context on this CPU and preemption is disabled,
2010 * hence we can't get into perf_event_task_sched_out for this context.
2012 static void _perf_event_disable(struct perf_event
*event
)
2014 struct perf_event_context
*ctx
= event
->ctx
;
2016 raw_spin_lock_irq(&ctx
->lock
);
2017 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
2018 raw_spin_unlock_irq(&ctx
->lock
);
2021 raw_spin_unlock_irq(&ctx
->lock
);
2023 event_function_call(event
, __perf_event_disable
, NULL
);
2026 void perf_event_disable_local(struct perf_event
*event
)
2028 event_function_local(event
, __perf_event_disable
, NULL
);
2032 * Strictly speaking kernel users cannot create groups and therefore this
2033 * interface does not need the perf_event_ctx_lock() magic.
2035 void perf_event_disable(struct perf_event
*event
)
2037 struct perf_event_context
*ctx
;
2039 ctx
= perf_event_ctx_lock(event
);
2040 _perf_event_disable(event
);
2041 perf_event_ctx_unlock(event
, ctx
);
2043 EXPORT_SYMBOL_GPL(perf_event_disable
);
2045 void perf_event_disable_inatomic(struct perf_event
*event
)
2047 event
->pending_disable
= 1;
2048 irq_work_queue(&event
->pending
);
2051 static void perf_set_shadow_time(struct perf_event
*event
,
2052 struct perf_event_context
*ctx
,
2056 * use the correct time source for the time snapshot
2058 * We could get by without this by leveraging the
2059 * fact that to get to this function, the caller
2060 * has most likely already called update_context_time()
2061 * and update_cgrp_time_xx() and thus both timestamp
2062 * are identical (or very close). Given that tstamp is,
2063 * already adjusted for cgroup, we could say that:
2064 * tstamp - ctx->timestamp
2066 * tstamp - cgrp->timestamp.
2068 * Then, in perf_output_read(), the calculation would
2069 * work with no changes because:
2070 * - event is guaranteed scheduled in
2071 * - no scheduled out in between
2072 * - thus the timestamp would be the same
2074 * But this is a bit hairy.
2076 * So instead, we have an explicit cgroup call to remain
2077 * within the time time source all along. We believe it
2078 * is cleaner and simpler to understand.
2080 if (is_cgroup_event(event
))
2081 perf_cgroup_set_shadow_time(event
, tstamp
);
2083 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
2086 #define MAX_INTERRUPTS (~0ULL)
2088 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2089 static void perf_log_itrace_start(struct perf_event
*event
);
2092 event_sched_in(struct perf_event
*event
,
2093 struct perf_cpu_context
*cpuctx
,
2094 struct perf_event_context
*ctx
)
2096 u64 tstamp
= perf_event_time(event
);
2099 lockdep_assert_held(&ctx
->lock
);
2101 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2104 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2106 * Order event::oncpu write to happen before the ACTIVE state
2110 WRITE_ONCE(event
->state
, PERF_EVENT_STATE_ACTIVE
);
2113 * Unthrottle events, since we scheduled we might have missed several
2114 * ticks already, also for a heavily scheduling task there is little
2115 * guarantee it'll get a tick in a timely manner.
2117 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2118 perf_log_throttle(event
, 1);
2119 event
->hw
.interrupts
= 0;
2123 * The new state must be visible before we turn it on in the hardware:
2127 perf_pmu_disable(event
->pmu
);
2129 perf_set_shadow_time(event
, ctx
, tstamp
);
2131 perf_log_itrace_start(event
);
2133 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2134 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2140 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
2142 if (!is_software_event(event
))
2143 cpuctx
->active_oncpu
++;
2144 if (!ctx
->nr_active
++)
2145 perf_event_ctx_activate(ctx
);
2146 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2149 if (event
->attr
.exclusive
)
2150 cpuctx
->exclusive
= 1;
2153 perf_pmu_enable(event
->pmu
);
2159 group_sched_in(struct perf_event
*group_event
,
2160 struct perf_cpu_context
*cpuctx
,
2161 struct perf_event_context
*ctx
)
2163 struct perf_event
*event
, *partial_group
= NULL
;
2164 struct pmu
*pmu
= ctx
->pmu
;
2165 u64 now
= ctx
->time
;
2166 bool simulate
= false;
2168 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2171 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2173 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2174 pmu
->cancel_txn(pmu
);
2175 perf_mux_hrtimer_restart(cpuctx
);
2180 * Schedule in siblings as one group (if any):
2182 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2183 if (event_sched_in(event
, cpuctx
, ctx
)) {
2184 partial_group
= event
;
2189 if (!pmu
->commit_txn(pmu
))
2194 * Groups can be scheduled in as one unit only, so undo any
2195 * partial group before returning:
2196 * The events up to the failed event are scheduled out normally,
2197 * tstamp_stopped will be updated.
2199 * The failed events and the remaining siblings need to have
2200 * their timings updated as if they had gone thru event_sched_in()
2201 * and event_sched_out(). This is required to get consistent timings
2202 * across the group. This also takes care of the case where the group
2203 * could never be scheduled by ensuring tstamp_stopped is set to mark
2204 * the time the event was actually stopped, such that time delta
2205 * calculation in update_event_times() is correct.
2207 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2208 if (event
== partial_group
)
2212 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2213 event
->tstamp_stopped
= now
;
2215 event_sched_out(event
, cpuctx
, ctx
);
2218 event_sched_out(group_event
, cpuctx
, ctx
);
2220 pmu
->cancel_txn(pmu
);
2222 perf_mux_hrtimer_restart(cpuctx
);
2228 * Work out whether we can put this event group on the CPU now.
2230 static int group_can_go_on(struct perf_event
*event
,
2231 struct perf_cpu_context
*cpuctx
,
2235 * Groups consisting entirely of software events can always go on.
2237 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2240 * If an exclusive group is already on, no other hardware
2243 if (cpuctx
->exclusive
)
2246 * If this group is exclusive and there are already
2247 * events on the CPU, it can't go on.
2249 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2252 * Otherwise, try to add it if all previous groups were able
2259 * Complement to update_event_times(). This computes the tstamp_* values to
2260 * continue 'enabled' state from @now, and effectively discards the time
2261 * between the prior tstamp_stopped and now (as we were in the OFF state, or
2262 * just switched (context) time base).
2264 * This further assumes '@event->state == INACTIVE' (we just came from OFF) and
2265 * cannot have been scheduled in yet. And going into INACTIVE state means
2266 * '@event->tstamp_stopped = @now'.
2268 * Thus given the rules of update_event_times():
2270 * total_time_enabled = tstamp_stopped - tstamp_enabled
2271 * total_time_running = tstamp_stopped - tstamp_running
2273 * We can insert 'tstamp_stopped == now' and reverse them to compute new
2276 static void __perf_event_enable_time(struct perf_event
*event
, u64 now
)
2278 WARN_ON_ONCE(event
->state
!= PERF_EVENT_STATE_INACTIVE
);
2280 event
->tstamp_stopped
= now
;
2281 event
->tstamp_enabled
= now
- event
->total_time_enabled
;
2282 event
->tstamp_running
= now
- event
->total_time_running
;
2285 static void add_event_to_ctx(struct perf_event
*event
,
2286 struct perf_event_context
*ctx
)
2288 u64 tstamp
= perf_event_time(event
);
2290 list_add_event(event
, ctx
);
2291 perf_group_attach(event
);
2293 * We can be called with event->state == STATE_OFF when we create with
2294 * .disabled = 1. In that case the IOC_ENABLE will call this function.
2296 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
2297 __perf_event_enable_time(event
, tstamp
);
2300 static void ctx_sched_out(struct perf_event_context
*ctx
,
2301 struct perf_cpu_context
*cpuctx
,
2302 enum event_type_t event_type
);
2304 ctx_sched_in(struct perf_event_context
*ctx
,
2305 struct perf_cpu_context
*cpuctx
,
2306 enum event_type_t event_type
,
2307 struct task_struct
*task
);
2309 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2310 struct perf_event_context
*ctx
,
2311 enum event_type_t event_type
)
2313 if (!cpuctx
->task_ctx
)
2316 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2319 ctx_sched_out(ctx
, cpuctx
, event_type
);
2322 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2323 struct perf_event_context
*ctx
,
2324 struct task_struct
*task
)
2326 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2328 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2329 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2331 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2335 * We want to maintain the following priority of scheduling:
2336 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2337 * - task pinned (EVENT_PINNED)
2338 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2339 * - task flexible (EVENT_FLEXIBLE).
2341 * In order to avoid unscheduling and scheduling back in everything every
2342 * time an event is added, only do it for the groups of equal priority and
2345 * This can be called after a batch operation on task events, in which case
2346 * event_type is a bit mask of the types of events involved. For CPU events,
2347 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2349 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2350 struct perf_event_context
*task_ctx
,
2351 enum event_type_t event_type
)
2353 enum event_type_t ctx_event_type
;
2354 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2357 * If pinned groups are involved, flexible groups also need to be
2360 if (event_type
& EVENT_PINNED
)
2361 event_type
|= EVENT_FLEXIBLE
;
2363 ctx_event_type
= event_type
& EVENT_ALL
;
2365 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2367 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2370 * Decide which cpu ctx groups to schedule out based on the types
2371 * of events that caused rescheduling:
2372 * - EVENT_CPU: schedule out corresponding groups;
2373 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2374 * - otherwise, do nothing more.
2377 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2378 else if (ctx_event_type
& EVENT_PINNED
)
2379 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2381 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2382 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2386 * Cross CPU call to install and enable a performance event
2388 * Very similar to remote_function() + event_function() but cannot assume that
2389 * things like ctx->is_active and cpuctx->task_ctx are set.
2391 static int __perf_install_in_context(void *info
)
2393 struct perf_event
*event
= info
;
2394 struct perf_event_context
*ctx
= event
->ctx
;
2395 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2396 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2397 bool reprogram
= true;
2400 raw_spin_lock(&cpuctx
->ctx
.lock
);
2402 raw_spin_lock(&ctx
->lock
);
2405 reprogram
= (ctx
->task
== current
);
2408 * If the task is running, it must be running on this CPU,
2409 * otherwise we cannot reprogram things.
2411 * If its not running, we don't care, ctx->lock will
2412 * serialize against it becoming runnable.
2414 if (task_curr(ctx
->task
) && !reprogram
) {
2419 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2420 } else if (task_ctx
) {
2421 raw_spin_lock(&task_ctx
->lock
);
2424 #ifdef CONFIG_CGROUP_PERF
2425 if (is_cgroup_event(event
)) {
2427 * If the current cgroup doesn't match the event's
2428 * cgroup, we should not try to schedule it.
2430 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
, ctx
);
2431 reprogram
= cgroup_is_descendant(cgrp
->css
.cgroup
,
2432 event
->cgrp
->css
.cgroup
);
2437 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2438 add_event_to_ctx(event
, ctx
);
2439 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2441 add_event_to_ctx(event
, ctx
);
2445 perf_ctx_unlock(cpuctx
, task_ctx
);
2451 * Attach a performance event to a context.
2453 * Very similar to event_function_call, see comment there.
2456 perf_install_in_context(struct perf_event_context
*ctx
,
2457 struct perf_event
*event
,
2460 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2462 lockdep_assert_held(&ctx
->mutex
);
2464 if (event
->cpu
!= -1)
2468 * Ensures that if we can observe event->ctx, both the event and ctx
2469 * will be 'complete'. See perf_iterate_sb_cpu().
2471 smp_store_release(&event
->ctx
, ctx
);
2474 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2479 * Should not happen, we validate the ctx is still alive before calling.
2481 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2485 * Installing events is tricky because we cannot rely on ctx->is_active
2486 * to be set in case this is the nr_events 0 -> 1 transition.
2488 * Instead we use task_curr(), which tells us if the task is running.
2489 * However, since we use task_curr() outside of rq::lock, we can race
2490 * against the actual state. This means the result can be wrong.
2492 * If we get a false positive, we retry, this is harmless.
2494 * If we get a false negative, things are complicated. If we are after
2495 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2496 * value must be correct. If we're before, it doesn't matter since
2497 * perf_event_context_sched_in() will program the counter.
2499 * However, this hinges on the remote context switch having observed
2500 * our task->perf_event_ctxp[] store, such that it will in fact take
2501 * ctx::lock in perf_event_context_sched_in().
2503 * We do this by task_function_call(), if the IPI fails to hit the task
2504 * we know any future context switch of task must see the
2505 * perf_event_ctpx[] store.
2509 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2510 * task_cpu() load, such that if the IPI then does not find the task
2511 * running, a future context switch of that task must observe the
2516 if (!task_function_call(task
, __perf_install_in_context
, event
))
2519 raw_spin_lock_irq(&ctx
->lock
);
2521 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2523 * Cannot happen because we already checked above (which also
2524 * cannot happen), and we hold ctx->mutex, which serializes us
2525 * against perf_event_exit_task_context().
2527 raw_spin_unlock_irq(&ctx
->lock
);
2531 * If the task is not running, ctx->lock will avoid it becoming so,
2532 * thus we can safely install the event.
2534 if (task_curr(task
)) {
2535 raw_spin_unlock_irq(&ctx
->lock
);
2538 add_event_to_ctx(event
, ctx
);
2539 raw_spin_unlock_irq(&ctx
->lock
);
2543 * Put a event into inactive state and update time fields.
2544 * Enabling the leader of a group effectively enables all
2545 * the group members that aren't explicitly disabled, so we
2546 * have to update their ->tstamp_enabled also.
2547 * Note: this works for group members as well as group leaders
2548 * since the non-leader members' sibling_lists will be empty.
2550 static void __perf_event_mark_enabled(struct perf_event
*event
)
2552 struct perf_event
*sub
;
2553 u64 tstamp
= perf_event_time(event
);
2555 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2556 __perf_event_enable_time(event
, tstamp
);
2557 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2558 /* XXX should not be > INACTIVE if event isn't */
2559 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2560 __perf_event_enable_time(sub
, tstamp
);
2565 * Cross CPU call to enable a performance event
2567 static void __perf_event_enable(struct perf_event
*event
,
2568 struct perf_cpu_context
*cpuctx
,
2569 struct perf_event_context
*ctx
,
2572 struct perf_event
*leader
= event
->group_leader
;
2573 struct perf_event_context
*task_ctx
;
2575 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2576 event
->state
<= PERF_EVENT_STATE_ERROR
)
2580 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2582 __perf_event_mark_enabled(event
);
2584 if (!ctx
->is_active
)
2587 if (!event_filter_match(event
)) {
2588 if (is_cgroup_event(event
))
2589 perf_cgroup_defer_enabled(event
);
2590 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2595 * If the event is in a group and isn't the group leader,
2596 * then don't put it on unless the group is on.
2598 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2599 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2603 task_ctx
= cpuctx
->task_ctx
;
2605 WARN_ON_ONCE(task_ctx
!= ctx
);
2607 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2613 * If event->ctx is a cloned context, callers must make sure that
2614 * every task struct that event->ctx->task could possibly point to
2615 * remains valid. This condition is satisfied when called through
2616 * perf_event_for_each_child or perf_event_for_each as described
2617 * for perf_event_disable.
2619 static void _perf_event_enable(struct perf_event
*event
)
2621 struct perf_event_context
*ctx
= event
->ctx
;
2623 raw_spin_lock_irq(&ctx
->lock
);
2624 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2625 event
->state
< PERF_EVENT_STATE_ERROR
) {
2626 raw_spin_unlock_irq(&ctx
->lock
);
2631 * If the event is in error state, clear that first.
2633 * That way, if we see the event in error state below, we know that it
2634 * has gone back into error state, as distinct from the task having
2635 * been scheduled away before the cross-call arrived.
2637 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2638 event
->state
= PERF_EVENT_STATE_OFF
;
2639 raw_spin_unlock_irq(&ctx
->lock
);
2641 event_function_call(event
, __perf_event_enable
, NULL
);
2645 * See perf_event_disable();
2647 void perf_event_enable(struct perf_event
*event
)
2649 struct perf_event_context
*ctx
;
2651 ctx
= perf_event_ctx_lock(event
);
2652 _perf_event_enable(event
);
2653 perf_event_ctx_unlock(event
, ctx
);
2655 EXPORT_SYMBOL_GPL(perf_event_enable
);
2657 struct stop_event_data
{
2658 struct perf_event
*event
;
2659 unsigned int restart
;
2662 static int __perf_event_stop(void *info
)
2664 struct stop_event_data
*sd
= info
;
2665 struct perf_event
*event
= sd
->event
;
2667 /* if it's already INACTIVE, do nothing */
2668 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2671 /* matches smp_wmb() in event_sched_in() */
2675 * There is a window with interrupts enabled before we get here,
2676 * so we need to check again lest we try to stop another CPU's event.
2678 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2681 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2684 * May race with the actual stop (through perf_pmu_output_stop()),
2685 * but it is only used for events with AUX ring buffer, and such
2686 * events will refuse to restart because of rb::aux_mmap_count==0,
2687 * see comments in perf_aux_output_begin().
2689 * Since this is happening on a event-local CPU, no trace is lost
2693 event
->pmu
->start(event
, 0);
2698 static int perf_event_stop(struct perf_event
*event
, int restart
)
2700 struct stop_event_data sd
= {
2707 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2710 /* matches smp_wmb() in event_sched_in() */
2714 * We only want to restart ACTIVE events, so if the event goes
2715 * inactive here (event->oncpu==-1), there's nothing more to do;
2716 * fall through with ret==-ENXIO.
2718 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2719 __perf_event_stop
, &sd
);
2720 } while (ret
== -EAGAIN
);
2726 * In order to contain the amount of racy and tricky in the address filter
2727 * configuration management, it is a two part process:
2729 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2730 * we update the addresses of corresponding vmas in
2731 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2732 * (p2) when an event is scheduled in (pmu::add), it calls
2733 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2734 * if the generation has changed since the previous call.
2736 * If (p1) happens while the event is active, we restart it to force (p2).
2738 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2739 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2741 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2742 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2744 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2747 void perf_event_addr_filters_sync(struct perf_event
*event
)
2749 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2751 if (!has_addr_filter(event
))
2754 raw_spin_lock(&ifh
->lock
);
2755 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2756 event
->pmu
->addr_filters_sync(event
);
2757 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2759 raw_spin_unlock(&ifh
->lock
);
2761 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2763 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2766 * not supported on inherited events
2768 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2771 atomic_add(refresh
, &event
->event_limit
);
2772 _perf_event_enable(event
);
2778 * See perf_event_disable()
2780 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2782 struct perf_event_context
*ctx
;
2785 ctx
= perf_event_ctx_lock(event
);
2786 ret
= _perf_event_refresh(event
, refresh
);
2787 perf_event_ctx_unlock(event
, ctx
);
2791 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2793 static void ctx_sched_out(struct perf_event_context
*ctx
,
2794 struct perf_cpu_context
*cpuctx
,
2795 enum event_type_t event_type
)
2797 int is_active
= ctx
->is_active
;
2798 struct perf_event
*event
;
2800 lockdep_assert_held(&ctx
->lock
);
2802 if (likely(!ctx
->nr_events
)) {
2804 * See __perf_remove_from_context().
2806 WARN_ON_ONCE(ctx
->is_active
);
2808 WARN_ON_ONCE(cpuctx
->task_ctx
);
2812 ctx
->is_active
&= ~event_type
;
2813 if (!(ctx
->is_active
& EVENT_ALL
))
2817 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2818 if (!ctx
->is_active
)
2819 cpuctx
->task_ctx
= NULL
;
2823 * Always update time if it was set; not only when it changes.
2824 * Otherwise we can 'forget' to update time for any but the last
2825 * context we sched out. For example:
2827 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2828 * ctx_sched_out(.event_type = EVENT_PINNED)
2830 * would only update time for the pinned events.
2832 if (is_active
& EVENT_TIME
) {
2833 /* update (and stop) ctx time */
2834 update_context_time(ctx
);
2835 update_cgrp_time_from_cpuctx(cpuctx
);
2838 is_active
^= ctx
->is_active
; /* changed bits */
2840 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2843 perf_pmu_disable(ctx
->pmu
);
2844 if (is_active
& EVENT_PINNED
) {
2845 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2846 group_sched_out(event
, cpuctx
, ctx
);
2849 if (is_active
& EVENT_FLEXIBLE
) {
2850 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2851 group_sched_out(event
, cpuctx
, ctx
);
2853 perf_pmu_enable(ctx
->pmu
);
2857 * Test whether two contexts are equivalent, i.e. whether they have both been
2858 * cloned from the same version of the same context.
2860 * Equivalence is measured using a generation number in the context that is
2861 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2862 * and list_del_event().
2864 static int context_equiv(struct perf_event_context
*ctx1
,
2865 struct perf_event_context
*ctx2
)
2867 lockdep_assert_held(&ctx1
->lock
);
2868 lockdep_assert_held(&ctx2
->lock
);
2870 /* Pinning disables the swap optimization */
2871 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2874 /* If ctx1 is the parent of ctx2 */
2875 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2878 /* If ctx2 is the parent of ctx1 */
2879 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2883 * If ctx1 and ctx2 have the same parent; we flatten the parent
2884 * hierarchy, see perf_event_init_context().
2886 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2887 ctx1
->parent_gen
== ctx2
->parent_gen
)
2894 static void __perf_event_sync_stat(struct perf_event
*event
,
2895 struct perf_event
*next_event
)
2899 if (!event
->attr
.inherit_stat
)
2903 * Update the event value, we cannot use perf_event_read()
2904 * because we're in the middle of a context switch and have IRQs
2905 * disabled, which upsets smp_call_function_single(), however
2906 * we know the event must be on the current CPU, therefore we
2907 * don't need to use it.
2909 switch (event
->state
) {
2910 case PERF_EVENT_STATE_ACTIVE
:
2911 event
->pmu
->read(event
);
2914 case PERF_EVENT_STATE_INACTIVE
:
2915 update_event_times(event
);
2923 * In order to keep per-task stats reliable we need to flip the event
2924 * values when we flip the contexts.
2926 value
= local64_read(&next_event
->count
);
2927 value
= local64_xchg(&event
->count
, value
);
2928 local64_set(&next_event
->count
, value
);
2930 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2931 swap(event
->total_time_running
, next_event
->total_time_running
);
2934 * Since we swizzled the values, update the user visible data too.
2936 perf_event_update_userpage(event
);
2937 perf_event_update_userpage(next_event
);
2940 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2941 struct perf_event_context
*next_ctx
)
2943 struct perf_event
*event
, *next_event
;
2948 update_context_time(ctx
);
2950 event
= list_first_entry(&ctx
->event_list
,
2951 struct perf_event
, event_entry
);
2953 next_event
= list_first_entry(&next_ctx
->event_list
,
2954 struct perf_event
, event_entry
);
2956 while (&event
->event_entry
!= &ctx
->event_list
&&
2957 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2959 __perf_event_sync_stat(event
, next_event
);
2961 event
= list_next_entry(event
, event_entry
);
2962 next_event
= list_next_entry(next_event
, event_entry
);
2966 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2967 struct task_struct
*next
)
2969 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2970 struct perf_event_context
*next_ctx
;
2971 struct perf_event_context
*parent
, *next_parent
;
2972 struct perf_cpu_context
*cpuctx
;
2978 cpuctx
= __get_cpu_context(ctx
);
2979 if (!cpuctx
->task_ctx
)
2983 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2987 parent
= rcu_dereference(ctx
->parent_ctx
);
2988 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2990 /* If neither context have a parent context; they cannot be clones. */
2991 if (!parent
&& !next_parent
)
2994 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2996 * Looks like the two contexts are clones, so we might be
2997 * able to optimize the context switch. We lock both
2998 * contexts and check that they are clones under the
2999 * lock (including re-checking that neither has been
3000 * uncloned in the meantime). It doesn't matter which
3001 * order we take the locks because no other cpu could
3002 * be trying to lock both of these tasks.
3004 raw_spin_lock(&ctx
->lock
);
3005 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
3006 if (context_equiv(ctx
, next_ctx
)) {
3007 WRITE_ONCE(ctx
->task
, next
);
3008 WRITE_ONCE(next_ctx
->task
, task
);
3010 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
3013 * RCU_INIT_POINTER here is safe because we've not
3014 * modified the ctx and the above modification of
3015 * ctx->task and ctx->task_ctx_data are immaterial
3016 * since those values are always verified under
3017 * ctx->lock which we're now holding.
3019 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
3020 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
3024 perf_event_sync_stat(ctx
, next_ctx
);
3026 raw_spin_unlock(&next_ctx
->lock
);
3027 raw_spin_unlock(&ctx
->lock
);
3033 raw_spin_lock(&ctx
->lock
);
3034 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
3035 raw_spin_unlock(&ctx
->lock
);
3039 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
3041 void perf_sched_cb_dec(struct pmu
*pmu
)
3043 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3045 this_cpu_dec(perf_sched_cb_usages
);
3047 if (!--cpuctx
->sched_cb_usage
)
3048 list_del(&cpuctx
->sched_cb_entry
);
3052 void perf_sched_cb_inc(struct pmu
*pmu
)
3054 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3056 if (!cpuctx
->sched_cb_usage
++)
3057 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
3059 this_cpu_inc(perf_sched_cb_usages
);
3063 * This function provides the context switch callback to the lower code
3064 * layer. It is invoked ONLY when the context switch callback is enabled.
3066 * This callback is relevant even to per-cpu events; for example multi event
3067 * PEBS requires this to provide PID/TID information. This requires we flush
3068 * all queued PEBS records before we context switch to a new task.
3070 static void perf_pmu_sched_task(struct task_struct
*prev
,
3071 struct task_struct
*next
,
3074 struct perf_cpu_context
*cpuctx
;
3080 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
3081 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
3083 if (WARN_ON_ONCE(!pmu
->sched_task
))
3086 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3087 perf_pmu_disable(pmu
);
3089 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3091 perf_pmu_enable(pmu
);
3092 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3096 static void perf_event_switch(struct task_struct
*task
,
3097 struct task_struct
*next_prev
, bool sched_in
);
3099 #define for_each_task_context_nr(ctxn) \
3100 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3103 * Called from scheduler to remove the events of the current task,
3104 * with interrupts disabled.
3106 * We stop each event and update the event value in event->count.
3108 * This does not protect us against NMI, but disable()
3109 * sets the disabled bit in the control field of event _before_
3110 * accessing the event control register. If a NMI hits, then it will
3111 * not restart the event.
3113 void __perf_event_task_sched_out(struct task_struct
*task
,
3114 struct task_struct
*next
)
3118 if (__this_cpu_read(perf_sched_cb_usages
))
3119 perf_pmu_sched_task(task
, next
, false);
3121 if (atomic_read(&nr_switch_events
))
3122 perf_event_switch(task
, next
, false);
3124 for_each_task_context_nr(ctxn
)
3125 perf_event_context_sched_out(task
, ctxn
, next
);
3128 * if cgroup events exist on this CPU, then we need
3129 * to check if we have to switch out PMU state.
3130 * cgroup event are system-wide mode only
3132 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3133 perf_cgroup_sched_out(task
, next
);
3137 * Called with IRQs disabled
3139 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3140 enum event_type_t event_type
)
3142 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3146 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3147 struct perf_cpu_context
*cpuctx
)
3149 struct perf_event
*event
;
3151 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
3152 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3154 if (!event_filter_match(event
))
3157 /* may need to reset tstamp_enabled */
3158 if (is_cgroup_event(event
))
3159 perf_cgroup_mark_enabled(event
, ctx
);
3161 if (group_can_go_on(event
, cpuctx
, 1))
3162 group_sched_in(event
, cpuctx
, ctx
);
3165 * If this pinned group hasn't been scheduled,
3166 * put it in error state.
3168 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3169 update_group_times(event
);
3170 event
->state
= PERF_EVENT_STATE_ERROR
;
3176 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3177 struct perf_cpu_context
*cpuctx
)
3179 struct perf_event
*event
;
3182 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3183 /* Ignore events in OFF or ERROR state */
3184 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3187 * Listen to the 'cpu' scheduling filter constraint
3190 if (!event_filter_match(event
))
3193 /* may need to reset tstamp_enabled */
3194 if (is_cgroup_event(event
))
3195 perf_cgroup_mark_enabled(event
, ctx
);
3197 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3198 if (group_sched_in(event
, cpuctx
, ctx
))
3205 ctx_sched_in(struct perf_event_context
*ctx
,
3206 struct perf_cpu_context
*cpuctx
,
3207 enum event_type_t event_type
,
3208 struct task_struct
*task
)
3210 int is_active
= ctx
->is_active
;
3213 lockdep_assert_held(&ctx
->lock
);
3215 if (likely(!ctx
->nr_events
))
3218 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3221 cpuctx
->task_ctx
= ctx
;
3223 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3226 is_active
^= ctx
->is_active
; /* changed bits */
3228 if (is_active
& EVENT_TIME
) {
3229 /* start ctx time */
3231 ctx
->timestamp
= now
;
3232 perf_cgroup_set_timestamp(task
, ctx
);
3236 * First go through the list and put on any pinned groups
3237 * in order to give them the best chance of going on.
3239 if (is_active
& EVENT_PINNED
)
3240 ctx_pinned_sched_in(ctx
, cpuctx
);
3242 /* Then walk through the lower prio flexible groups */
3243 if (is_active
& EVENT_FLEXIBLE
)
3244 ctx_flexible_sched_in(ctx
, cpuctx
);
3247 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3248 enum event_type_t event_type
,
3249 struct task_struct
*task
)
3251 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3253 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3256 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3257 struct task_struct
*task
)
3259 struct perf_cpu_context
*cpuctx
;
3261 cpuctx
= __get_cpu_context(ctx
);
3262 if (cpuctx
->task_ctx
== ctx
)
3265 perf_ctx_lock(cpuctx
, ctx
);
3267 * We must check ctx->nr_events while holding ctx->lock, such
3268 * that we serialize against perf_install_in_context().
3270 if (!ctx
->nr_events
)
3273 perf_pmu_disable(ctx
->pmu
);
3275 * We want to keep the following priority order:
3276 * cpu pinned (that don't need to move), task pinned,
3277 * cpu flexible, task flexible.
3279 * However, if task's ctx is not carrying any pinned
3280 * events, no need to flip the cpuctx's events around.
3282 if (!list_empty(&ctx
->pinned_groups
))
3283 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3284 perf_event_sched_in(cpuctx
, ctx
, task
);
3285 perf_pmu_enable(ctx
->pmu
);
3288 perf_ctx_unlock(cpuctx
, ctx
);
3292 * Called from scheduler to add the events of the current task
3293 * with interrupts disabled.
3295 * We restore the event value and then enable it.
3297 * This does not protect us against NMI, but enable()
3298 * sets the enabled bit in the control field of event _before_
3299 * accessing the event control register. If a NMI hits, then it will
3300 * keep the event running.
3302 void __perf_event_task_sched_in(struct task_struct
*prev
,
3303 struct task_struct
*task
)
3305 struct perf_event_context
*ctx
;
3309 * If cgroup events exist on this CPU, then we need to check if we have
3310 * to switch in PMU state; cgroup event are system-wide mode only.
3312 * Since cgroup events are CPU events, we must schedule these in before
3313 * we schedule in the task events.
3315 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3316 perf_cgroup_sched_in(prev
, task
);
3318 for_each_task_context_nr(ctxn
) {
3319 ctx
= task
->perf_event_ctxp
[ctxn
];
3323 perf_event_context_sched_in(ctx
, task
);
3326 if (atomic_read(&nr_switch_events
))
3327 perf_event_switch(task
, prev
, true);
3329 if (__this_cpu_read(perf_sched_cb_usages
))
3330 perf_pmu_sched_task(prev
, task
, true);
3333 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3335 u64 frequency
= event
->attr
.sample_freq
;
3336 u64 sec
= NSEC_PER_SEC
;
3337 u64 divisor
, dividend
;
3339 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3341 count_fls
= fls64(count
);
3342 nsec_fls
= fls64(nsec
);
3343 frequency_fls
= fls64(frequency
);
3347 * We got @count in @nsec, with a target of sample_freq HZ
3348 * the target period becomes:
3351 * period = -------------------
3352 * @nsec * sample_freq
3357 * Reduce accuracy by one bit such that @a and @b converge
3358 * to a similar magnitude.
3360 #define REDUCE_FLS(a, b) \
3362 if (a##_fls > b##_fls) { \
3372 * Reduce accuracy until either term fits in a u64, then proceed with
3373 * the other, so that finally we can do a u64/u64 division.
3375 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3376 REDUCE_FLS(nsec
, frequency
);
3377 REDUCE_FLS(sec
, count
);
3380 if (count_fls
+ sec_fls
> 64) {
3381 divisor
= nsec
* frequency
;
3383 while (count_fls
+ sec_fls
> 64) {
3384 REDUCE_FLS(count
, sec
);
3388 dividend
= count
* sec
;
3390 dividend
= count
* sec
;
3392 while (nsec_fls
+ frequency_fls
> 64) {
3393 REDUCE_FLS(nsec
, frequency
);
3397 divisor
= nsec
* frequency
;
3403 return div64_u64(dividend
, divisor
);
3406 static DEFINE_PER_CPU(int, perf_throttled_count
);
3407 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3409 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3411 struct hw_perf_event
*hwc
= &event
->hw
;
3412 s64 period
, sample_period
;
3415 period
= perf_calculate_period(event
, nsec
, count
);
3417 delta
= (s64
)(period
- hwc
->sample_period
);
3418 delta
= (delta
+ 7) / 8; /* low pass filter */
3420 sample_period
= hwc
->sample_period
+ delta
;
3425 hwc
->sample_period
= sample_period
;
3427 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3429 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3431 local64_set(&hwc
->period_left
, 0);
3434 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3439 * combine freq adjustment with unthrottling to avoid two passes over the
3440 * events. At the same time, make sure, having freq events does not change
3441 * the rate of unthrottling as that would introduce bias.
3443 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3446 struct perf_event
*event
;
3447 struct hw_perf_event
*hwc
;
3448 u64 now
, period
= TICK_NSEC
;
3452 * only need to iterate over all events iff:
3453 * - context have events in frequency mode (needs freq adjust)
3454 * - there are events to unthrottle on this cpu
3456 if (!(ctx
->nr_freq
|| needs_unthr
))
3459 raw_spin_lock(&ctx
->lock
);
3460 perf_pmu_disable(ctx
->pmu
);
3462 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3463 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3466 if (!event_filter_match(event
))
3469 perf_pmu_disable(event
->pmu
);
3473 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3474 hwc
->interrupts
= 0;
3475 perf_log_throttle(event
, 1);
3476 event
->pmu
->start(event
, 0);
3479 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3483 * stop the event and update event->count
3485 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3487 now
= local64_read(&event
->count
);
3488 delta
= now
- hwc
->freq_count_stamp
;
3489 hwc
->freq_count_stamp
= now
;
3493 * reload only if value has changed
3494 * we have stopped the event so tell that
3495 * to perf_adjust_period() to avoid stopping it
3499 perf_adjust_period(event
, period
, delta
, false);
3501 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3503 perf_pmu_enable(event
->pmu
);
3506 perf_pmu_enable(ctx
->pmu
);
3507 raw_spin_unlock(&ctx
->lock
);
3511 * Round-robin a context's events:
3513 static void rotate_ctx(struct perf_event_context
*ctx
)
3516 * Rotate the first entry last of non-pinned groups. Rotation might be
3517 * disabled by the inheritance code.
3519 if (!ctx
->rotate_disable
)
3520 list_rotate_left(&ctx
->flexible_groups
);
3523 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3525 struct perf_event_context
*ctx
= NULL
;
3528 if (cpuctx
->ctx
.nr_events
) {
3529 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3533 ctx
= cpuctx
->task_ctx
;
3534 if (ctx
&& ctx
->nr_events
) {
3535 if (ctx
->nr_events
!= ctx
->nr_active
)
3542 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3543 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3545 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3547 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3549 rotate_ctx(&cpuctx
->ctx
);
3553 perf_event_sched_in(cpuctx
, ctx
, current
);
3555 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3556 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3562 void perf_event_task_tick(void)
3564 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3565 struct perf_event_context
*ctx
, *tmp
;
3568 WARN_ON(!irqs_disabled());
3570 __this_cpu_inc(perf_throttled_seq
);
3571 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3572 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3574 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3575 perf_adjust_freq_unthr_context(ctx
, throttled
);
3578 static int event_enable_on_exec(struct perf_event
*event
,
3579 struct perf_event_context
*ctx
)
3581 if (!event
->attr
.enable_on_exec
)
3584 event
->attr
.enable_on_exec
= 0;
3585 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3588 __perf_event_mark_enabled(event
);
3594 * Enable all of a task's events that have been marked enable-on-exec.
3595 * This expects task == current.
3597 static void perf_event_enable_on_exec(int ctxn
)
3599 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3600 enum event_type_t event_type
= 0;
3601 struct perf_cpu_context
*cpuctx
;
3602 struct perf_event
*event
;
3603 unsigned long flags
;
3606 local_irq_save(flags
);
3607 ctx
= current
->perf_event_ctxp
[ctxn
];
3608 if (!ctx
|| !ctx
->nr_events
)
3611 cpuctx
= __get_cpu_context(ctx
);
3612 perf_ctx_lock(cpuctx
, ctx
);
3613 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3614 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3615 enabled
|= event_enable_on_exec(event
, ctx
);
3616 event_type
|= get_event_type(event
);
3620 * Unclone and reschedule this context if we enabled any event.
3623 clone_ctx
= unclone_ctx(ctx
);
3624 ctx_resched(cpuctx
, ctx
, event_type
);
3626 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3628 perf_ctx_unlock(cpuctx
, ctx
);
3631 local_irq_restore(flags
);
3637 struct perf_read_data
{
3638 struct perf_event
*event
;
3643 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3645 u16 local_pkg
, event_pkg
;
3647 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3648 int local_cpu
= smp_processor_id();
3650 event_pkg
= topology_physical_package_id(event_cpu
);
3651 local_pkg
= topology_physical_package_id(local_cpu
);
3653 if (event_pkg
== local_pkg
)
3661 * Cross CPU call to read the hardware event
3663 static void __perf_event_read(void *info
)
3665 struct perf_read_data
*data
= info
;
3666 struct perf_event
*sub
, *event
= data
->event
;
3667 struct perf_event_context
*ctx
= event
->ctx
;
3668 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3669 struct pmu
*pmu
= event
->pmu
;
3672 * If this is a task context, we need to check whether it is
3673 * the current task context of this cpu. If not it has been
3674 * scheduled out before the smp call arrived. In that case
3675 * event->count would have been updated to a recent sample
3676 * when the event was scheduled out.
3678 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3681 raw_spin_lock(&ctx
->lock
);
3682 if (ctx
->is_active
) {
3683 update_context_time(ctx
);
3684 update_cgrp_time_from_event(event
);
3687 update_event_times(event
);
3688 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3697 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3701 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3702 update_event_times(sub
);
3703 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3705 * Use sibling's PMU rather than @event's since
3706 * sibling could be on different (eg: software) PMU.
3708 sub
->pmu
->read(sub
);
3712 data
->ret
= pmu
->commit_txn(pmu
);
3715 raw_spin_unlock(&ctx
->lock
);
3718 static inline u64
perf_event_count(struct perf_event
*event
)
3720 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
3724 * NMI-safe method to read a local event, that is an event that
3726 * - either for the current task, or for this CPU
3727 * - does not have inherit set, for inherited task events
3728 * will not be local and we cannot read them atomically
3729 * - must not have a pmu::count method
3731 int perf_event_read_local(struct perf_event
*event
, u64
*value
)
3733 unsigned long flags
;
3737 * Disabling interrupts avoids all counter scheduling (context
3738 * switches, timer based rotation and IPIs).
3740 local_irq_save(flags
);
3743 * It must not be an event with inherit set, we cannot read
3744 * all child counters from atomic context.
3746 if (event
->attr
.inherit
) {
3751 /* If this is a per-task event, it must be for current */
3752 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
3753 event
->hw
.target
!= current
) {
3758 /* If this is a per-CPU event, it must be for this CPU */
3759 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3760 event
->cpu
!= smp_processor_id()) {
3766 * If the event is currently on this CPU, its either a per-task event,
3767 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3770 if (event
->oncpu
== smp_processor_id())
3771 event
->pmu
->read(event
);
3773 *value
= local64_read(&event
->count
);
3775 local_irq_restore(flags
);
3780 static int perf_event_read(struct perf_event
*event
, bool group
)
3782 int event_cpu
, ret
= 0;
3785 * If event is enabled and currently active on a CPU, update the
3786 * value in the event structure:
3788 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3789 struct perf_read_data data
= {
3795 event_cpu
= READ_ONCE(event
->oncpu
);
3796 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3800 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
3803 * Purposely ignore the smp_call_function_single() return
3806 * If event_cpu isn't a valid CPU it means the event got
3807 * scheduled out and that will have updated the event count.
3809 * Therefore, either way, we'll have an up-to-date event count
3812 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
3815 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3816 struct perf_event_context
*ctx
= event
->ctx
;
3817 unsigned long flags
;
3819 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3821 * may read while context is not active
3822 * (e.g., thread is blocked), in that case
3823 * we cannot update context time
3825 if (ctx
->is_active
) {
3826 update_context_time(ctx
);
3827 update_cgrp_time_from_event(event
);
3830 update_group_times(event
);
3832 update_event_times(event
);
3833 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3840 * Initialize the perf_event context in a task_struct:
3842 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3844 raw_spin_lock_init(&ctx
->lock
);
3845 mutex_init(&ctx
->mutex
);
3846 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3847 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3848 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3849 INIT_LIST_HEAD(&ctx
->event_list
);
3850 atomic_set(&ctx
->refcount
, 1);
3853 static struct perf_event_context
*
3854 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3856 struct perf_event_context
*ctx
;
3858 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3862 __perf_event_init_context(ctx
);
3865 get_task_struct(task
);
3872 static struct task_struct
*
3873 find_lively_task_by_vpid(pid_t vpid
)
3875 struct task_struct
*task
;
3881 task
= find_task_by_vpid(vpid
);
3883 get_task_struct(task
);
3887 return ERR_PTR(-ESRCH
);
3893 * Returns a matching context with refcount and pincount.
3895 static struct perf_event_context
*
3896 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3897 struct perf_event
*event
)
3899 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3900 struct perf_cpu_context
*cpuctx
;
3901 void *task_ctx_data
= NULL
;
3902 unsigned long flags
;
3904 int cpu
= event
->cpu
;
3907 /* Must be root to operate on a CPU event: */
3908 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3909 return ERR_PTR(-EACCES
);
3911 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3920 ctxn
= pmu
->task_ctx_nr
;
3924 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3925 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3926 if (!task_ctx_data
) {
3933 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3935 clone_ctx
= unclone_ctx(ctx
);
3938 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3939 ctx
->task_ctx_data
= task_ctx_data
;
3940 task_ctx_data
= NULL
;
3942 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3947 ctx
= alloc_perf_context(pmu
, task
);
3952 if (task_ctx_data
) {
3953 ctx
->task_ctx_data
= task_ctx_data
;
3954 task_ctx_data
= NULL
;
3958 mutex_lock(&task
->perf_event_mutex
);
3960 * If it has already passed perf_event_exit_task().
3961 * we must see PF_EXITING, it takes this mutex too.
3963 if (task
->flags
& PF_EXITING
)
3965 else if (task
->perf_event_ctxp
[ctxn
])
3970 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3972 mutex_unlock(&task
->perf_event_mutex
);
3974 if (unlikely(err
)) {
3983 kfree(task_ctx_data
);
3987 kfree(task_ctx_data
);
3988 return ERR_PTR(err
);
3991 static void perf_event_free_filter(struct perf_event
*event
);
3992 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3994 static void free_event_rcu(struct rcu_head
*head
)
3996 struct perf_event
*event
;
3998 event
= container_of(head
, struct perf_event
, rcu_head
);
4000 put_pid_ns(event
->ns
);
4001 perf_event_free_filter(event
);
4005 static void ring_buffer_attach(struct perf_event
*event
,
4006 struct ring_buffer
*rb
);
4008 static void detach_sb_event(struct perf_event
*event
)
4010 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
4012 raw_spin_lock(&pel
->lock
);
4013 list_del_rcu(&event
->sb_list
);
4014 raw_spin_unlock(&pel
->lock
);
4017 static bool is_sb_event(struct perf_event
*event
)
4019 struct perf_event_attr
*attr
= &event
->attr
;
4024 if (event
->attach_state
& PERF_ATTACH_TASK
)
4027 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
4028 attr
->comm
|| attr
->comm_exec
||
4030 attr
->context_switch
)
4035 static void unaccount_pmu_sb_event(struct perf_event
*event
)
4037 if (is_sb_event(event
))
4038 detach_sb_event(event
);
4041 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
4046 if (is_cgroup_event(event
))
4047 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
4050 #ifdef CONFIG_NO_HZ_FULL
4051 static DEFINE_SPINLOCK(nr_freq_lock
);
4054 static void unaccount_freq_event_nohz(void)
4056 #ifdef CONFIG_NO_HZ_FULL
4057 spin_lock(&nr_freq_lock
);
4058 if (atomic_dec_and_test(&nr_freq_events
))
4059 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
4060 spin_unlock(&nr_freq_lock
);
4064 static void unaccount_freq_event(void)
4066 if (tick_nohz_full_enabled())
4067 unaccount_freq_event_nohz();
4069 atomic_dec(&nr_freq_events
);
4072 static void unaccount_event(struct perf_event
*event
)
4079 if (event
->attach_state
& PERF_ATTACH_TASK
)
4081 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
4082 atomic_dec(&nr_mmap_events
);
4083 if (event
->attr
.comm
)
4084 atomic_dec(&nr_comm_events
);
4085 if (event
->attr
.namespaces
)
4086 atomic_dec(&nr_namespaces_events
);
4087 if (event
->attr
.task
)
4088 atomic_dec(&nr_task_events
);
4089 if (event
->attr
.freq
)
4090 unaccount_freq_event();
4091 if (event
->attr
.context_switch
) {
4093 atomic_dec(&nr_switch_events
);
4095 if (is_cgroup_event(event
))
4097 if (has_branch_stack(event
))
4101 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4102 schedule_delayed_work(&perf_sched_work
, HZ
);
4105 unaccount_event_cpu(event
, event
->cpu
);
4107 unaccount_pmu_sb_event(event
);
4110 static void perf_sched_delayed(struct work_struct
*work
)
4112 mutex_lock(&perf_sched_mutex
);
4113 if (atomic_dec_and_test(&perf_sched_count
))
4114 static_branch_disable(&perf_sched_events
);
4115 mutex_unlock(&perf_sched_mutex
);
4119 * The following implement mutual exclusion of events on "exclusive" pmus
4120 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4121 * at a time, so we disallow creating events that might conflict, namely:
4123 * 1) cpu-wide events in the presence of per-task events,
4124 * 2) per-task events in the presence of cpu-wide events,
4125 * 3) two matching events on the same context.
4127 * The former two cases are handled in the allocation path (perf_event_alloc(),
4128 * _free_event()), the latter -- before the first perf_install_in_context().
4130 static int exclusive_event_init(struct perf_event
*event
)
4132 struct pmu
*pmu
= event
->pmu
;
4134 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4138 * Prevent co-existence of per-task and cpu-wide events on the
4139 * same exclusive pmu.
4141 * Negative pmu::exclusive_cnt means there are cpu-wide
4142 * events on this "exclusive" pmu, positive means there are
4145 * Since this is called in perf_event_alloc() path, event::ctx
4146 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4147 * to mean "per-task event", because unlike other attach states it
4148 * never gets cleared.
4150 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4151 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4154 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4161 static void exclusive_event_destroy(struct perf_event
*event
)
4163 struct pmu
*pmu
= event
->pmu
;
4165 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4168 /* see comment in exclusive_event_init() */
4169 if (event
->attach_state
& PERF_ATTACH_TASK
)
4170 atomic_dec(&pmu
->exclusive_cnt
);
4172 atomic_inc(&pmu
->exclusive_cnt
);
4175 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4177 if ((e1
->pmu
== e2
->pmu
) &&
4178 (e1
->cpu
== e2
->cpu
||
4185 /* Called under the same ctx::mutex as perf_install_in_context() */
4186 static bool exclusive_event_installable(struct perf_event
*event
,
4187 struct perf_event_context
*ctx
)
4189 struct perf_event
*iter_event
;
4190 struct pmu
*pmu
= event
->pmu
;
4192 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4195 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4196 if (exclusive_event_match(iter_event
, event
))
4203 static void perf_addr_filters_splice(struct perf_event
*event
,
4204 struct list_head
*head
);
4206 static void _free_event(struct perf_event
*event
)
4208 irq_work_sync(&event
->pending
);
4210 unaccount_event(event
);
4214 * Can happen when we close an event with re-directed output.
4216 * Since we have a 0 refcount, perf_mmap_close() will skip
4217 * over us; possibly making our ring_buffer_put() the last.
4219 mutex_lock(&event
->mmap_mutex
);
4220 ring_buffer_attach(event
, NULL
);
4221 mutex_unlock(&event
->mmap_mutex
);
4224 if (is_cgroup_event(event
))
4225 perf_detach_cgroup(event
);
4227 if (!event
->parent
) {
4228 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4229 put_callchain_buffers();
4232 perf_event_free_bpf_prog(event
);
4233 perf_addr_filters_splice(event
, NULL
);
4234 kfree(event
->addr_filters_offs
);
4237 event
->destroy(event
);
4240 put_ctx(event
->ctx
);
4242 if (event
->hw
.target
)
4243 put_task_struct(event
->hw
.target
);
4245 exclusive_event_destroy(event
);
4246 module_put(event
->pmu
->module
);
4248 call_rcu(&event
->rcu_head
, free_event_rcu
);
4252 * Used to free events which have a known refcount of 1, such as in error paths
4253 * where the event isn't exposed yet and inherited events.
4255 static void free_event(struct perf_event
*event
)
4257 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4258 "unexpected event refcount: %ld; ptr=%p\n",
4259 atomic_long_read(&event
->refcount
), event
)) {
4260 /* leak to avoid use-after-free */
4268 * Remove user event from the owner task.
4270 static void perf_remove_from_owner(struct perf_event
*event
)
4272 struct task_struct
*owner
;
4276 * Matches the smp_store_release() in perf_event_exit_task(). If we
4277 * observe !owner it means the list deletion is complete and we can
4278 * indeed free this event, otherwise we need to serialize on
4279 * owner->perf_event_mutex.
4281 owner
= READ_ONCE(event
->owner
);
4284 * Since delayed_put_task_struct() also drops the last
4285 * task reference we can safely take a new reference
4286 * while holding the rcu_read_lock().
4288 get_task_struct(owner
);
4294 * If we're here through perf_event_exit_task() we're already
4295 * holding ctx->mutex which would be an inversion wrt. the
4296 * normal lock order.
4298 * However we can safely take this lock because its the child
4301 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4304 * We have to re-check the event->owner field, if it is cleared
4305 * we raced with perf_event_exit_task(), acquiring the mutex
4306 * ensured they're done, and we can proceed with freeing the
4310 list_del_init(&event
->owner_entry
);
4311 smp_store_release(&event
->owner
, NULL
);
4313 mutex_unlock(&owner
->perf_event_mutex
);
4314 put_task_struct(owner
);
4318 static void put_event(struct perf_event
*event
)
4320 if (!atomic_long_dec_and_test(&event
->refcount
))
4327 * Kill an event dead; while event:refcount will preserve the event
4328 * object, it will not preserve its functionality. Once the last 'user'
4329 * gives up the object, we'll destroy the thing.
4331 int perf_event_release_kernel(struct perf_event
*event
)
4333 struct perf_event_context
*ctx
= event
->ctx
;
4334 struct perf_event
*child
, *tmp
;
4337 * If we got here through err_file: fput(event_file); we will not have
4338 * attached to a context yet.
4341 WARN_ON_ONCE(event
->attach_state
&
4342 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4346 if (!is_kernel_event(event
))
4347 perf_remove_from_owner(event
);
4349 ctx
= perf_event_ctx_lock(event
);
4350 WARN_ON_ONCE(ctx
->parent_ctx
);
4351 perf_remove_from_context(event
, DETACH_GROUP
);
4353 raw_spin_lock_irq(&ctx
->lock
);
4355 * Mark this event as STATE_DEAD, there is no external reference to it
4358 * Anybody acquiring event->child_mutex after the below loop _must_
4359 * also see this, most importantly inherit_event() which will avoid
4360 * placing more children on the list.
4362 * Thus this guarantees that we will in fact observe and kill _ALL_
4365 event
->state
= PERF_EVENT_STATE_DEAD
;
4366 raw_spin_unlock_irq(&ctx
->lock
);
4368 perf_event_ctx_unlock(event
, ctx
);
4371 mutex_lock(&event
->child_mutex
);
4372 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4375 * Cannot change, child events are not migrated, see the
4376 * comment with perf_event_ctx_lock_nested().
4378 ctx
= READ_ONCE(child
->ctx
);
4380 * Since child_mutex nests inside ctx::mutex, we must jump
4381 * through hoops. We start by grabbing a reference on the ctx.
4383 * Since the event cannot get freed while we hold the
4384 * child_mutex, the context must also exist and have a !0
4390 * Now that we have a ctx ref, we can drop child_mutex, and
4391 * acquire ctx::mutex without fear of it going away. Then we
4392 * can re-acquire child_mutex.
4394 mutex_unlock(&event
->child_mutex
);
4395 mutex_lock(&ctx
->mutex
);
4396 mutex_lock(&event
->child_mutex
);
4399 * Now that we hold ctx::mutex and child_mutex, revalidate our
4400 * state, if child is still the first entry, it didn't get freed
4401 * and we can continue doing so.
4403 tmp
= list_first_entry_or_null(&event
->child_list
,
4404 struct perf_event
, child_list
);
4406 perf_remove_from_context(child
, DETACH_GROUP
);
4407 list_del(&child
->child_list
);
4410 * This matches the refcount bump in inherit_event();
4411 * this can't be the last reference.
4416 mutex_unlock(&event
->child_mutex
);
4417 mutex_unlock(&ctx
->mutex
);
4421 mutex_unlock(&event
->child_mutex
);
4424 put_event(event
); /* Must be the 'last' reference */
4427 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4430 * Called when the last reference to the file is gone.
4432 static int perf_release(struct inode
*inode
, struct file
*file
)
4434 perf_event_release_kernel(file
->private_data
);
4438 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4440 struct perf_event
*child
;
4446 mutex_lock(&event
->child_mutex
);
4448 (void)perf_event_read(event
, false);
4449 total
+= perf_event_count(event
);
4451 *enabled
+= event
->total_time_enabled
+
4452 atomic64_read(&event
->child_total_time_enabled
);
4453 *running
+= event
->total_time_running
+
4454 atomic64_read(&event
->child_total_time_running
);
4456 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4457 (void)perf_event_read(child
, false);
4458 total
+= perf_event_count(child
);
4459 *enabled
+= child
->total_time_enabled
;
4460 *running
+= child
->total_time_running
;
4462 mutex_unlock(&event
->child_mutex
);
4466 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4468 static int __perf_read_group_add(struct perf_event
*leader
,
4469 u64 read_format
, u64
*values
)
4471 struct perf_event_context
*ctx
= leader
->ctx
;
4472 struct perf_event
*sub
;
4473 unsigned long flags
;
4474 int n
= 1; /* skip @nr */
4477 ret
= perf_event_read(leader
, true);
4481 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4484 * Since we co-schedule groups, {enabled,running} times of siblings
4485 * will be identical to those of the leader, so we only publish one
4488 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4489 values
[n
++] += leader
->total_time_enabled
+
4490 atomic64_read(&leader
->child_total_time_enabled
);
4493 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4494 values
[n
++] += leader
->total_time_running
+
4495 atomic64_read(&leader
->child_total_time_running
);
4499 * Write {count,id} tuples for every sibling.
4501 values
[n
++] += perf_event_count(leader
);
4502 if (read_format
& PERF_FORMAT_ID
)
4503 values
[n
++] = primary_event_id(leader
);
4505 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4506 values
[n
++] += perf_event_count(sub
);
4507 if (read_format
& PERF_FORMAT_ID
)
4508 values
[n
++] = primary_event_id(sub
);
4511 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4515 static int perf_read_group(struct perf_event
*event
,
4516 u64 read_format
, char __user
*buf
)
4518 struct perf_event
*leader
= event
->group_leader
, *child
;
4519 struct perf_event_context
*ctx
= leader
->ctx
;
4523 lockdep_assert_held(&ctx
->mutex
);
4525 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4529 values
[0] = 1 + leader
->nr_siblings
;
4532 * By locking the child_mutex of the leader we effectively
4533 * lock the child list of all siblings.. XXX explain how.
4535 mutex_lock(&leader
->child_mutex
);
4537 ret
= __perf_read_group_add(leader
, read_format
, values
);
4541 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4542 ret
= __perf_read_group_add(child
, read_format
, values
);
4547 mutex_unlock(&leader
->child_mutex
);
4549 ret
= event
->read_size
;
4550 if (copy_to_user(buf
, values
, event
->read_size
))
4555 mutex_unlock(&leader
->child_mutex
);
4561 static int perf_read_one(struct perf_event
*event
,
4562 u64 read_format
, char __user
*buf
)
4564 u64 enabled
, running
;
4568 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4569 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4570 values
[n
++] = enabled
;
4571 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4572 values
[n
++] = running
;
4573 if (read_format
& PERF_FORMAT_ID
)
4574 values
[n
++] = primary_event_id(event
);
4576 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4579 return n
* sizeof(u64
);
4582 static bool is_event_hup(struct perf_event
*event
)
4586 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4589 mutex_lock(&event
->child_mutex
);
4590 no_children
= list_empty(&event
->child_list
);
4591 mutex_unlock(&event
->child_mutex
);
4596 * Read the performance event - simple non blocking version for now
4599 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4601 u64 read_format
= event
->attr
.read_format
;
4605 * Return end-of-file for a read on a event that is in
4606 * error state (i.e. because it was pinned but it couldn't be
4607 * scheduled on to the CPU at some point).
4609 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4612 if (count
< event
->read_size
)
4615 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4616 if (read_format
& PERF_FORMAT_GROUP
)
4617 ret
= perf_read_group(event
, read_format
, buf
);
4619 ret
= perf_read_one(event
, read_format
, buf
);
4625 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4627 struct perf_event
*event
= file
->private_data
;
4628 struct perf_event_context
*ctx
;
4631 ctx
= perf_event_ctx_lock(event
);
4632 ret
= __perf_read(event
, buf
, count
);
4633 perf_event_ctx_unlock(event
, ctx
);
4638 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4640 struct perf_event
*event
= file
->private_data
;
4641 struct ring_buffer
*rb
;
4642 unsigned int events
= POLLHUP
;
4644 poll_wait(file
, &event
->waitq
, wait
);
4646 if (is_event_hup(event
))
4650 * Pin the event->rb by taking event->mmap_mutex; otherwise
4651 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4653 mutex_lock(&event
->mmap_mutex
);
4656 events
= atomic_xchg(&rb
->poll
, 0);
4657 mutex_unlock(&event
->mmap_mutex
);
4661 static void _perf_event_reset(struct perf_event
*event
)
4663 (void)perf_event_read(event
, false);
4664 local64_set(&event
->count
, 0);
4665 perf_event_update_userpage(event
);
4669 * Holding the top-level event's child_mutex means that any
4670 * descendant process that has inherited this event will block
4671 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4672 * task existence requirements of perf_event_enable/disable.
4674 static void perf_event_for_each_child(struct perf_event
*event
,
4675 void (*func
)(struct perf_event
*))
4677 struct perf_event
*child
;
4679 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4681 mutex_lock(&event
->child_mutex
);
4683 list_for_each_entry(child
, &event
->child_list
, child_list
)
4685 mutex_unlock(&event
->child_mutex
);
4688 static void perf_event_for_each(struct perf_event
*event
,
4689 void (*func
)(struct perf_event
*))
4691 struct perf_event_context
*ctx
= event
->ctx
;
4692 struct perf_event
*sibling
;
4694 lockdep_assert_held(&ctx
->mutex
);
4696 event
= event
->group_leader
;
4698 perf_event_for_each_child(event
, func
);
4699 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4700 perf_event_for_each_child(sibling
, func
);
4703 static void __perf_event_period(struct perf_event
*event
,
4704 struct perf_cpu_context
*cpuctx
,
4705 struct perf_event_context
*ctx
,
4708 u64 value
= *((u64
*)info
);
4711 if (event
->attr
.freq
) {
4712 event
->attr
.sample_freq
= value
;
4714 event
->attr
.sample_period
= value
;
4715 event
->hw
.sample_period
= value
;
4718 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4720 perf_pmu_disable(ctx
->pmu
);
4722 * We could be throttled; unthrottle now to avoid the tick
4723 * trying to unthrottle while we already re-started the event.
4725 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4726 event
->hw
.interrupts
= 0;
4727 perf_log_throttle(event
, 1);
4729 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4732 local64_set(&event
->hw
.period_left
, 0);
4735 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4736 perf_pmu_enable(ctx
->pmu
);
4740 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4744 if (!is_sampling_event(event
))
4747 if (copy_from_user(&value
, arg
, sizeof(value
)))
4753 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4756 event_function_call(event
, __perf_event_period
, &value
);
4761 static const struct file_operations perf_fops
;
4763 static inline int perf_fget_light(int fd
, struct fd
*p
)
4765 struct fd f
= fdget(fd
);
4769 if (f
.file
->f_op
!= &perf_fops
) {
4777 static int perf_event_set_output(struct perf_event
*event
,
4778 struct perf_event
*output_event
);
4779 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4780 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4782 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4784 void (*func
)(struct perf_event
*);
4788 case PERF_EVENT_IOC_ENABLE
:
4789 func
= _perf_event_enable
;
4791 case PERF_EVENT_IOC_DISABLE
:
4792 func
= _perf_event_disable
;
4794 case PERF_EVENT_IOC_RESET
:
4795 func
= _perf_event_reset
;
4798 case PERF_EVENT_IOC_REFRESH
:
4799 return _perf_event_refresh(event
, arg
);
4801 case PERF_EVENT_IOC_PERIOD
:
4802 return perf_event_period(event
, (u64 __user
*)arg
);
4804 case PERF_EVENT_IOC_ID
:
4806 u64 id
= primary_event_id(event
);
4808 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4813 case PERF_EVENT_IOC_SET_OUTPUT
:
4817 struct perf_event
*output_event
;
4819 ret
= perf_fget_light(arg
, &output
);
4822 output_event
= output
.file
->private_data
;
4823 ret
= perf_event_set_output(event
, output_event
);
4826 ret
= perf_event_set_output(event
, NULL
);
4831 case PERF_EVENT_IOC_SET_FILTER
:
4832 return perf_event_set_filter(event
, (void __user
*)arg
);
4834 case PERF_EVENT_IOC_SET_BPF
:
4835 return perf_event_set_bpf_prog(event
, arg
);
4837 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4838 struct ring_buffer
*rb
;
4841 rb
= rcu_dereference(event
->rb
);
4842 if (!rb
|| !rb
->nr_pages
) {
4846 rb_toggle_paused(rb
, !!arg
);
4854 if (flags
& PERF_IOC_FLAG_GROUP
)
4855 perf_event_for_each(event
, func
);
4857 perf_event_for_each_child(event
, func
);
4862 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4864 struct perf_event
*event
= file
->private_data
;
4865 struct perf_event_context
*ctx
;
4868 ctx
= perf_event_ctx_lock(event
);
4869 ret
= _perf_ioctl(event
, cmd
, arg
);
4870 perf_event_ctx_unlock(event
, ctx
);
4875 #ifdef CONFIG_COMPAT
4876 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4879 switch (_IOC_NR(cmd
)) {
4880 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4881 case _IOC_NR(PERF_EVENT_IOC_ID
):
4882 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4883 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4884 cmd
&= ~IOCSIZE_MASK
;
4885 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4889 return perf_ioctl(file
, cmd
, arg
);
4892 # define perf_compat_ioctl NULL
4895 int perf_event_task_enable(void)
4897 struct perf_event_context
*ctx
;
4898 struct perf_event
*event
;
4900 mutex_lock(¤t
->perf_event_mutex
);
4901 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4902 ctx
= perf_event_ctx_lock(event
);
4903 perf_event_for_each_child(event
, _perf_event_enable
);
4904 perf_event_ctx_unlock(event
, ctx
);
4906 mutex_unlock(¤t
->perf_event_mutex
);
4911 int perf_event_task_disable(void)
4913 struct perf_event_context
*ctx
;
4914 struct perf_event
*event
;
4916 mutex_lock(¤t
->perf_event_mutex
);
4917 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4918 ctx
= perf_event_ctx_lock(event
);
4919 perf_event_for_each_child(event
, _perf_event_disable
);
4920 perf_event_ctx_unlock(event
, ctx
);
4922 mutex_unlock(¤t
->perf_event_mutex
);
4927 static int perf_event_index(struct perf_event
*event
)
4929 if (event
->hw
.state
& PERF_HES_STOPPED
)
4932 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4935 return event
->pmu
->event_idx(event
);
4938 static void calc_timer_values(struct perf_event
*event
,
4945 *now
= perf_clock();
4946 ctx_time
= event
->shadow_ctx_time
+ *now
;
4947 *enabled
= ctx_time
- event
->tstamp_enabled
;
4948 *running
= ctx_time
- event
->tstamp_running
;
4951 static void perf_event_init_userpage(struct perf_event
*event
)
4953 struct perf_event_mmap_page
*userpg
;
4954 struct ring_buffer
*rb
;
4957 rb
= rcu_dereference(event
->rb
);
4961 userpg
= rb
->user_page
;
4963 /* Allow new userspace to detect that bit 0 is deprecated */
4964 userpg
->cap_bit0_is_deprecated
= 1;
4965 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4966 userpg
->data_offset
= PAGE_SIZE
;
4967 userpg
->data_size
= perf_data_size(rb
);
4973 void __weak
arch_perf_update_userpage(
4974 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4979 * Callers need to ensure there can be no nesting of this function, otherwise
4980 * the seqlock logic goes bad. We can not serialize this because the arch
4981 * code calls this from NMI context.
4983 void perf_event_update_userpage(struct perf_event
*event
)
4985 struct perf_event_mmap_page
*userpg
;
4986 struct ring_buffer
*rb
;
4987 u64 enabled
, running
, now
;
4990 rb
= rcu_dereference(event
->rb
);
4995 * compute total_time_enabled, total_time_running
4996 * based on snapshot values taken when the event
4997 * was last scheduled in.
4999 * we cannot simply called update_context_time()
5000 * because of locking issue as we can be called in
5003 calc_timer_values(event
, &now
, &enabled
, &running
);
5005 userpg
= rb
->user_page
;
5007 * Disable preemption so as to not let the corresponding user-space
5008 * spin too long if we get preempted.
5013 userpg
->index
= perf_event_index(event
);
5014 userpg
->offset
= perf_event_count(event
);
5016 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
5018 userpg
->time_enabled
= enabled
+
5019 atomic64_read(&event
->child_total_time_enabled
);
5021 userpg
->time_running
= running
+
5022 atomic64_read(&event
->child_total_time_running
);
5024 arch_perf_update_userpage(event
, userpg
, now
);
5033 static int perf_mmap_fault(struct vm_fault
*vmf
)
5035 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
5036 struct ring_buffer
*rb
;
5037 int ret
= VM_FAULT_SIGBUS
;
5039 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
5040 if (vmf
->pgoff
== 0)
5046 rb
= rcu_dereference(event
->rb
);
5050 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
5053 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
5057 get_page(vmf
->page
);
5058 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
5059 vmf
->page
->index
= vmf
->pgoff
;
5068 static void ring_buffer_attach(struct perf_event
*event
,
5069 struct ring_buffer
*rb
)
5071 struct ring_buffer
*old_rb
= NULL
;
5072 unsigned long flags
;
5076 * Should be impossible, we set this when removing
5077 * event->rb_entry and wait/clear when adding event->rb_entry.
5079 WARN_ON_ONCE(event
->rcu_pending
);
5082 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
5083 list_del_rcu(&event
->rb_entry
);
5084 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
5086 event
->rcu_batches
= get_state_synchronize_rcu();
5087 event
->rcu_pending
= 1;
5091 if (event
->rcu_pending
) {
5092 cond_synchronize_rcu(event
->rcu_batches
);
5093 event
->rcu_pending
= 0;
5096 spin_lock_irqsave(&rb
->event_lock
, flags
);
5097 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5098 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5102 * Avoid racing with perf_mmap_close(AUX): stop the event
5103 * before swizzling the event::rb pointer; if it's getting
5104 * unmapped, its aux_mmap_count will be 0 and it won't
5105 * restart. See the comment in __perf_pmu_output_stop().
5107 * Data will inevitably be lost when set_output is done in
5108 * mid-air, but then again, whoever does it like this is
5109 * not in for the data anyway.
5112 perf_event_stop(event
, 0);
5114 rcu_assign_pointer(event
->rb
, rb
);
5117 ring_buffer_put(old_rb
);
5119 * Since we detached before setting the new rb, so that we
5120 * could attach the new rb, we could have missed a wakeup.
5123 wake_up_all(&event
->waitq
);
5127 static void ring_buffer_wakeup(struct perf_event
*event
)
5129 struct ring_buffer
*rb
;
5132 rb
= rcu_dereference(event
->rb
);
5134 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5135 wake_up_all(&event
->waitq
);
5140 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5142 struct ring_buffer
*rb
;
5145 rb
= rcu_dereference(event
->rb
);
5147 if (!atomic_inc_not_zero(&rb
->refcount
))
5155 void ring_buffer_put(struct ring_buffer
*rb
)
5157 if (!atomic_dec_and_test(&rb
->refcount
))
5160 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5162 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5165 static void perf_mmap_open(struct vm_area_struct
*vma
)
5167 struct perf_event
*event
= vma
->vm_file
->private_data
;
5169 atomic_inc(&event
->mmap_count
);
5170 atomic_inc(&event
->rb
->mmap_count
);
5173 atomic_inc(&event
->rb
->aux_mmap_count
);
5175 if (event
->pmu
->event_mapped
)
5176 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5179 static void perf_pmu_output_stop(struct perf_event
*event
);
5182 * A buffer can be mmap()ed multiple times; either directly through the same
5183 * event, or through other events by use of perf_event_set_output().
5185 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5186 * the buffer here, where we still have a VM context. This means we need
5187 * to detach all events redirecting to us.
5189 static void perf_mmap_close(struct vm_area_struct
*vma
)
5191 struct perf_event
*event
= vma
->vm_file
->private_data
;
5193 struct ring_buffer
*rb
= ring_buffer_get(event
);
5194 struct user_struct
*mmap_user
= rb
->mmap_user
;
5195 int mmap_locked
= rb
->mmap_locked
;
5196 unsigned long size
= perf_data_size(rb
);
5198 if (event
->pmu
->event_unmapped
)
5199 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
5202 * rb->aux_mmap_count will always drop before rb->mmap_count and
5203 * event->mmap_count, so it is ok to use event->mmap_mutex to
5204 * serialize with perf_mmap here.
5206 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5207 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5209 * Stop all AUX events that are writing to this buffer,
5210 * so that we can free its AUX pages and corresponding PMU
5211 * data. Note that after rb::aux_mmap_count dropped to zero,
5212 * they won't start any more (see perf_aux_output_begin()).
5214 perf_pmu_output_stop(event
);
5216 /* now it's safe to free the pages */
5217 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5218 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5220 /* this has to be the last one */
5222 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5224 mutex_unlock(&event
->mmap_mutex
);
5227 atomic_dec(&rb
->mmap_count
);
5229 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5232 ring_buffer_attach(event
, NULL
);
5233 mutex_unlock(&event
->mmap_mutex
);
5235 /* If there's still other mmap()s of this buffer, we're done. */
5236 if (atomic_read(&rb
->mmap_count
))
5240 * No other mmap()s, detach from all other events that might redirect
5241 * into the now unreachable buffer. Somewhat complicated by the
5242 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5246 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5247 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5249 * This event is en-route to free_event() which will
5250 * detach it and remove it from the list.
5256 mutex_lock(&event
->mmap_mutex
);
5258 * Check we didn't race with perf_event_set_output() which can
5259 * swizzle the rb from under us while we were waiting to
5260 * acquire mmap_mutex.
5262 * If we find a different rb; ignore this event, a next
5263 * iteration will no longer find it on the list. We have to
5264 * still restart the iteration to make sure we're not now
5265 * iterating the wrong list.
5267 if (event
->rb
== rb
)
5268 ring_buffer_attach(event
, NULL
);
5270 mutex_unlock(&event
->mmap_mutex
);
5274 * Restart the iteration; either we're on the wrong list or
5275 * destroyed its integrity by doing a deletion.
5282 * It could be there's still a few 0-ref events on the list; they'll
5283 * get cleaned up by free_event() -- they'll also still have their
5284 * ref on the rb and will free it whenever they are done with it.
5286 * Aside from that, this buffer is 'fully' detached and unmapped,
5287 * undo the VM accounting.
5290 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5291 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5292 free_uid(mmap_user
);
5295 ring_buffer_put(rb
); /* could be last */
5298 static const struct vm_operations_struct perf_mmap_vmops
= {
5299 .open
= perf_mmap_open
,
5300 .close
= perf_mmap_close
, /* non mergable */
5301 .fault
= perf_mmap_fault
,
5302 .page_mkwrite
= perf_mmap_fault
,
5305 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5307 struct perf_event
*event
= file
->private_data
;
5308 unsigned long user_locked
, user_lock_limit
;
5309 struct user_struct
*user
= current_user();
5310 unsigned long locked
, lock_limit
;
5311 struct ring_buffer
*rb
= NULL
;
5312 unsigned long vma_size
;
5313 unsigned long nr_pages
;
5314 long user_extra
= 0, extra
= 0;
5315 int ret
= 0, flags
= 0;
5318 * Don't allow mmap() of inherited per-task counters. This would
5319 * create a performance issue due to all children writing to the
5322 if (event
->cpu
== -1 && event
->attr
.inherit
)
5325 if (!(vma
->vm_flags
& VM_SHARED
))
5328 vma_size
= vma
->vm_end
- vma
->vm_start
;
5330 if (vma
->vm_pgoff
== 0) {
5331 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5334 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5335 * mapped, all subsequent mappings should have the same size
5336 * and offset. Must be above the normal perf buffer.
5338 u64 aux_offset
, aux_size
;
5343 nr_pages
= vma_size
/ PAGE_SIZE
;
5345 mutex_lock(&event
->mmap_mutex
);
5352 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
5353 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
5355 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5358 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5361 /* already mapped with a different offset */
5362 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5365 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5368 /* already mapped with a different size */
5369 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5372 if (!is_power_of_2(nr_pages
))
5375 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5378 if (rb_has_aux(rb
)) {
5379 atomic_inc(&rb
->aux_mmap_count
);
5384 atomic_set(&rb
->aux_mmap_count
, 1);
5385 user_extra
= nr_pages
;
5391 * If we have rb pages ensure they're a power-of-two number, so we
5392 * can do bitmasks instead of modulo.
5394 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5397 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5400 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5402 mutex_lock(&event
->mmap_mutex
);
5404 if (event
->rb
->nr_pages
!= nr_pages
) {
5409 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5411 * Raced against perf_mmap_close() through
5412 * perf_event_set_output(). Try again, hope for better
5415 mutex_unlock(&event
->mmap_mutex
);
5422 user_extra
= nr_pages
+ 1;
5425 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5428 * Increase the limit linearly with more CPUs:
5430 user_lock_limit
*= num_online_cpus();
5432 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5434 if (user_locked
> user_lock_limit
)
5435 extra
= user_locked
- user_lock_limit
;
5437 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5438 lock_limit
>>= PAGE_SHIFT
;
5439 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5441 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5442 !capable(CAP_IPC_LOCK
)) {
5447 WARN_ON(!rb
&& event
->rb
);
5449 if (vma
->vm_flags
& VM_WRITE
)
5450 flags
|= RING_BUFFER_WRITABLE
;
5453 rb
= rb_alloc(nr_pages
,
5454 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5462 atomic_set(&rb
->mmap_count
, 1);
5463 rb
->mmap_user
= get_current_user();
5464 rb
->mmap_locked
= extra
;
5466 ring_buffer_attach(event
, rb
);
5468 perf_event_init_userpage(event
);
5469 perf_event_update_userpage(event
);
5471 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5472 event
->attr
.aux_watermark
, flags
);
5474 rb
->aux_mmap_locked
= extra
;
5479 atomic_long_add(user_extra
, &user
->locked_vm
);
5480 vma
->vm_mm
->pinned_vm
+= extra
;
5482 atomic_inc(&event
->mmap_count
);
5484 atomic_dec(&rb
->mmap_count
);
5487 mutex_unlock(&event
->mmap_mutex
);
5490 * Since pinned accounting is per vm we cannot allow fork() to copy our
5493 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5494 vma
->vm_ops
= &perf_mmap_vmops
;
5496 if (event
->pmu
->event_mapped
)
5497 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5502 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5504 struct inode
*inode
= file_inode(filp
);
5505 struct perf_event
*event
= filp
->private_data
;
5509 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5510 inode_unlock(inode
);
5518 static const struct file_operations perf_fops
= {
5519 .llseek
= no_llseek
,
5520 .release
= perf_release
,
5523 .unlocked_ioctl
= perf_ioctl
,
5524 .compat_ioctl
= perf_compat_ioctl
,
5526 .fasync
= perf_fasync
,
5532 * If there's data, ensure we set the poll() state and publish everything
5533 * to user-space before waking everybody up.
5536 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5538 /* only the parent has fasync state */
5540 event
= event
->parent
;
5541 return &event
->fasync
;
5544 void perf_event_wakeup(struct perf_event
*event
)
5546 ring_buffer_wakeup(event
);
5548 if (event
->pending_kill
) {
5549 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5550 event
->pending_kill
= 0;
5554 static void perf_pending_event(struct irq_work
*entry
)
5556 struct perf_event
*event
= container_of(entry
,
5557 struct perf_event
, pending
);
5560 rctx
= perf_swevent_get_recursion_context();
5562 * If we 'fail' here, that's OK, it means recursion is already disabled
5563 * and we won't recurse 'further'.
5566 if (event
->pending_disable
) {
5567 event
->pending_disable
= 0;
5568 perf_event_disable_local(event
);
5571 if (event
->pending_wakeup
) {
5572 event
->pending_wakeup
= 0;
5573 perf_event_wakeup(event
);
5577 perf_swevent_put_recursion_context(rctx
);
5581 * We assume there is only KVM supporting the callbacks.
5582 * Later on, we might change it to a list if there is
5583 * another virtualization implementation supporting the callbacks.
5585 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5587 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5589 perf_guest_cbs
= cbs
;
5592 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5594 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5596 perf_guest_cbs
= NULL
;
5599 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5602 perf_output_sample_regs(struct perf_output_handle
*handle
,
5603 struct pt_regs
*regs
, u64 mask
)
5606 DECLARE_BITMAP(_mask
, 64);
5608 bitmap_from_u64(_mask
, mask
);
5609 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5612 val
= perf_reg_value(regs
, bit
);
5613 perf_output_put(handle
, val
);
5617 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5618 struct pt_regs
*regs
,
5619 struct pt_regs
*regs_user_copy
)
5621 if (user_mode(regs
)) {
5622 regs_user
->abi
= perf_reg_abi(current
);
5623 regs_user
->regs
= regs
;
5624 } else if (current
->mm
) {
5625 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5627 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5628 regs_user
->regs
= NULL
;
5632 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5633 struct pt_regs
*regs
)
5635 regs_intr
->regs
= regs
;
5636 regs_intr
->abi
= perf_reg_abi(current
);
5641 * Get remaining task size from user stack pointer.
5643 * It'd be better to take stack vma map and limit this more
5644 * precisly, but there's no way to get it safely under interrupt,
5645 * so using TASK_SIZE as limit.
5647 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5649 unsigned long addr
= perf_user_stack_pointer(regs
);
5651 if (!addr
|| addr
>= TASK_SIZE
)
5654 return TASK_SIZE
- addr
;
5658 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5659 struct pt_regs
*regs
)
5663 /* No regs, no stack pointer, no dump. */
5668 * Check if we fit in with the requested stack size into the:
5670 * If we don't, we limit the size to the TASK_SIZE.
5672 * - remaining sample size
5673 * If we don't, we customize the stack size to
5674 * fit in to the remaining sample size.
5677 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5678 stack_size
= min(stack_size
, (u16
) task_size
);
5680 /* Current header size plus static size and dynamic size. */
5681 header_size
+= 2 * sizeof(u64
);
5683 /* Do we fit in with the current stack dump size? */
5684 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5686 * If we overflow the maximum size for the sample,
5687 * we customize the stack dump size to fit in.
5689 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5690 stack_size
= round_up(stack_size
, sizeof(u64
));
5697 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5698 struct pt_regs
*regs
)
5700 /* Case of a kernel thread, nothing to dump */
5703 perf_output_put(handle
, size
);
5713 * - the size requested by user or the best one we can fit
5714 * in to the sample max size
5716 * - user stack dump data
5718 * - the actual dumped size
5722 perf_output_put(handle
, dump_size
);
5725 sp
= perf_user_stack_pointer(regs
);
5728 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5730 dyn_size
= dump_size
- rem
;
5732 perf_output_skip(handle
, rem
);
5735 perf_output_put(handle
, dyn_size
);
5739 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5740 struct perf_sample_data
*data
,
5741 struct perf_event
*event
)
5743 u64 sample_type
= event
->attr
.sample_type
;
5745 data
->type
= sample_type
;
5746 header
->size
+= event
->id_header_size
;
5748 if (sample_type
& PERF_SAMPLE_TID
) {
5749 /* namespace issues */
5750 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5751 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5754 if (sample_type
& PERF_SAMPLE_TIME
)
5755 data
->time
= perf_event_clock(event
);
5757 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5758 data
->id
= primary_event_id(event
);
5760 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5761 data
->stream_id
= event
->id
;
5763 if (sample_type
& PERF_SAMPLE_CPU
) {
5764 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5765 data
->cpu_entry
.reserved
= 0;
5769 void perf_event_header__init_id(struct perf_event_header
*header
,
5770 struct perf_sample_data
*data
,
5771 struct perf_event
*event
)
5773 if (event
->attr
.sample_id_all
)
5774 __perf_event_header__init_id(header
, data
, event
);
5777 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5778 struct perf_sample_data
*data
)
5780 u64 sample_type
= data
->type
;
5782 if (sample_type
& PERF_SAMPLE_TID
)
5783 perf_output_put(handle
, data
->tid_entry
);
5785 if (sample_type
& PERF_SAMPLE_TIME
)
5786 perf_output_put(handle
, data
->time
);
5788 if (sample_type
& PERF_SAMPLE_ID
)
5789 perf_output_put(handle
, data
->id
);
5791 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5792 perf_output_put(handle
, data
->stream_id
);
5794 if (sample_type
& PERF_SAMPLE_CPU
)
5795 perf_output_put(handle
, data
->cpu_entry
);
5797 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5798 perf_output_put(handle
, data
->id
);
5801 void perf_event__output_id_sample(struct perf_event
*event
,
5802 struct perf_output_handle
*handle
,
5803 struct perf_sample_data
*sample
)
5805 if (event
->attr
.sample_id_all
)
5806 __perf_event__output_id_sample(handle
, sample
);
5809 static void perf_output_read_one(struct perf_output_handle
*handle
,
5810 struct perf_event
*event
,
5811 u64 enabled
, u64 running
)
5813 u64 read_format
= event
->attr
.read_format
;
5817 values
[n
++] = perf_event_count(event
);
5818 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5819 values
[n
++] = enabled
+
5820 atomic64_read(&event
->child_total_time_enabled
);
5822 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5823 values
[n
++] = running
+
5824 atomic64_read(&event
->child_total_time_running
);
5826 if (read_format
& PERF_FORMAT_ID
)
5827 values
[n
++] = primary_event_id(event
);
5829 __output_copy(handle
, values
, n
* sizeof(u64
));
5832 static void perf_output_read_group(struct perf_output_handle
*handle
,
5833 struct perf_event
*event
,
5834 u64 enabled
, u64 running
)
5836 struct perf_event
*leader
= event
->group_leader
, *sub
;
5837 u64 read_format
= event
->attr
.read_format
;
5841 values
[n
++] = 1 + leader
->nr_siblings
;
5843 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5844 values
[n
++] = enabled
;
5846 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5847 values
[n
++] = running
;
5849 if ((leader
!= event
) &&
5850 (leader
->state
== PERF_EVENT_STATE_ACTIVE
))
5851 leader
->pmu
->read(leader
);
5853 values
[n
++] = perf_event_count(leader
);
5854 if (read_format
& PERF_FORMAT_ID
)
5855 values
[n
++] = primary_event_id(leader
);
5857 __output_copy(handle
, values
, n
* sizeof(u64
));
5859 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5862 if ((sub
!= event
) &&
5863 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5864 sub
->pmu
->read(sub
);
5866 values
[n
++] = perf_event_count(sub
);
5867 if (read_format
& PERF_FORMAT_ID
)
5868 values
[n
++] = primary_event_id(sub
);
5870 __output_copy(handle
, values
, n
* sizeof(u64
));
5874 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5875 PERF_FORMAT_TOTAL_TIME_RUNNING)
5878 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
5880 * The problem is that its both hard and excessively expensive to iterate the
5881 * child list, not to mention that its impossible to IPI the children running
5882 * on another CPU, from interrupt/NMI context.
5884 static void perf_output_read(struct perf_output_handle
*handle
,
5885 struct perf_event
*event
)
5887 u64 enabled
= 0, running
= 0, now
;
5888 u64 read_format
= event
->attr
.read_format
;
5891 * compute total_time_enabled, total_time_running
5892 * based on snapshot values taken when the event
5893 * was last scheduled in.
5895 * we cannot simply called update_context_time()
5896 * because of locking issue as we are called in
5899 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5900 calc_timer_values(event
, &now
, &enabled
, &running
);
5902 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5903 perf_output_read_group(handle
, event
, enabled
, running
);
5905 perf_output_read_one(handle
, event
, enabled
, running
);
5908 void perf_output_sample(struct perf_output_handle
*handle
,
5909 struct perf_event_header
*header
,
5910 struct perf_sample_data
*data
,
5911 struct perf_event
*event
)
5913 u64 sample_type
= data
->type
;
5915 perf_output_put(handle
, *header
);
5917 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5918 perf_output_put(handle
, data
->id
);
5920 if (sample_type
& PERF_SAMPLE_IP
)
5921 perf_output_put(handle
, data
->ip
);
5923 if (sample_type
& PERF_SAMPLE_TID
)
5924 perf_output_put(handle
, data
->tid_entry
);
5926 if (sample_type
& PERF_SAMPLE_TIME
)
5927 perf_output_put(handle
, data
->time
);
5929 if (sample_type
& PERF_SAMPLE_ADDR
)
5930 perf_output_put(handle
, data
->addr
);
5932 if (sample_type
& PERF_SAMPLE_ID
)
5933 perf_output_put(handle
, data
->id
);
5935 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5936 perf_output_put(handle
, data
->stream_id
);
5938 if (sample_type
& PERF_SAMPLE_CPU
)
5939 perf_output_put(handle
, data
->cpu_entry
);
5941 if (sample_type
& PERF_SAMPLE_PERIOD
)
5942 perf_output_put(handle
, data
->period
);
5944 if (sample_type
& PERF_SAMPLE_READ
)
5945 perf_output_read(handle
, event
);
5947 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5948 if (data
->callchain
) {
5951 if (data
->callchain
)
5952 size
+= data
->callchain
->nr
;
5954 size
*= sizeof(u64
);
5956 __output_copy(handle
, data
->callchain
, size
);
5959 perf_output_put(handle
, nr
);
5963 if (sample_type
& PERF_SAMPLE_RAW
) {
5964 struct perf_raw_record
*raw
= data
->raw
;
5967 struct perf_raw_frag
*frag
= &raw
->frag
;
5969 perf_output_put(handle
, raw
->size
);
5972 __output_custom(handle
, frag
->copy
,
5973 frag
->data
, frag
->size
);
5975 __output_copy(handle
, frag
->data
,
5978 if (perf_raw_frag_last(frag
))
5983 __output_skip(handle
, NULL
, frag
->pad
);
5989 .size
= sizeof(u32
),
5992 perf_output_put(handle
, raw
);
5996 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5997 if (data
->br_stack
) {
6000 size
= data
->br_stack
->nr
6001 * sizeof(struct perf_branch_entry
);
6003 perf_output_put(handle
, data
->br_stack
->nr
);
6004 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
6007 * we always store at least the value of nr
6010 perf_output_put(handle
, nr
);
6014 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6015 u64 abi
= data
->regs_user
.abi
;
6018 * If there are no regs to dump, notice it through
6019 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6021 perf_output_put(handle
, abi
);
6024 u64 mask
= event
->attr
.sample_regs_user
;
6025 perf_output_sample_regs(handle
,
6026 data
->regs_user
.regs
,
6031 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6032 perf_output_sample_ustack(handle
,
6033 data
->stack_user_size
,
6034 data
->regs_user
.regs
);
6037 if (sample_type
& PERF_SAMPLE_WEIGHT
)
6038 perf_output_put(handle
, data
->weight
);
6040 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
6041 perf_output_put(handle
, data
->data_src
.val
);
6043 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
6044 perf_output_put(handle
, data
->txn
);
6046 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6047 u64 abi
= data
->regs_intr
.abi
;
6049 * If there are no regs to dump, notice it through
6050 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
6052 perf_output_put(handle
, abi
);
6055 u64 mask
= event
->attr
.sample_regs_intr
;
6057 perf_output_sample_regs(handle
,
6058 data
->regs_intr
.regs
,
6063 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6064 perf_output_put(handle
, data
->phys_addr
);
6066 if (!event
->attr
.watermark
) {
6067 int wakeup_events
= event
->attr
.wakeup_events
;
6069 if (wakeup_events
) {
6070 struct ring_buffer
*rb
= handle
->rb
;
6071 int events
= local_inc_return(&rb
->events
);
6073 if (events
>= wakeup_events
) {
6074 local_sub(wakeup_events
, &rb
->events
);
6075 local_inc(&rb
->wakeup
);
6081 static u64
perf_virt_to_phys(u64 virt
)
6084 struct page
*p
= NULL
;
6089 if (virt
>= TASK_SIZE
) {
6090 /* If it's vmalloc()d memory, leave phys_addr as 0 */
6091 if (virt_addr_valid((void *)(uintptr_t)virt
) &&
6092 !(virt
>= VMALLOC_START
&& virt
< VMALLOC_END
))
6093 phys_addr
= (u64
)virt_to_phys((void *)(uintptr_t)virt
);
6096 * Walking the pages tables for user address.
6097 * Interrupts are disabled, so it prevents any tear down
6098 * of the page tables.
6099 * Try IRQ-safe __get_user_pages_fast first.
6100 * If failed, leave phys_addr as 0.
6102 if ((current
->mm
!= NULL
) &&
6103 (__get_user_pages_fast(virt
, 1, 0, &p
) == 1))
6104 phys_addr
= page_to_phys(p
) + virt
% PAGE_SIZE
;
6113 void perf_prepare_sample(struct perf_event_header
*header
,
6114 struct perf_sample_data
*data
,
6115 struct perf_event
*event
,
6116 struct pt_regs
*regs
)
6118 u64 sample_type
= event
->attr
.sample_type
;
6120 header
->type
= PERF_RECORD_SAMPLE
;
6121 header
->size
= sizeof(*header
) + event
->header_size
;
6124 header
->misc
|= perf_misc_flags(regs
);
6126 __perf_event_header__init_id(header
, data
, event
);
6128 if (sample_type
& PERF_SAMPLE_IP
)
6129 data
->ip
= perf_instruction_pointer(regs
);
6131 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6134 data
->callchain
= perf_callchain(event
, regs
);
6136 if (data
->callchain
)
6137 size
+= data
->callchain
->nr
;
6139 header
->size
+= size
* sizeof(u64
);
6142 if (sample_type
& PERF_SAMPLE_RAW
) {
6143 struct perf_raw_record
*raw
= data
->raw
;
6147 struct perf_raw_frag
*frag
= &raw
->frag
;
6152 if (perf_raw_frag_last(frag
))
6157 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6158 raw
->size
= size
- sizeof(u32
);
6159 frag
->pad
= raw
->size
- sum
;
6164 header
->size
+= size
;
6167 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6168 int size
= sizeof(u64
); /* nr */
6169 if (data
->br_stack
) {
6170 size
+= data
->br_stack
->nr
6171 * sizeof(struct perf_branch_entry
);
6173 header
->size
+= size
;
6176 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6177 perf_sample_regs_user(&data
->regs_user
, regs
,
6178 &data
->regs_user_copy
);
6180 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6181 /* regs dump ABI info */
6182 int size
= sizeof(u64
);
6184 if (data
->regs_user
.regs
) {
6185 u64 mask
= event
->attr
.sample_regs_user
;
6186 size
+= hweight64(mask
) * sizeof(u64
);
6189 header
->size
+= size
;
6192 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6194 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6195 * processed as the last one or have additional check added
6196 * in case new sample type is added, because we could eat
6197 * up the rest of the sample size.
6199 u16 stack_size
= event
->attr
.sample_stack_user
;
6200 u16 size
= sizeof(u64
);
6202 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6203 data
->regs_user
.regs
);
6206 * If there is something to dump, add space for the dump
6207 * itself and for the field that tells the dynamic size,
6208 * which is how many have been actually dumped.
6211 size
+= sizeof(u64
) + stack_size
;
6213 data
->stack_user_size
= stack_size
;
6214 header
->size
+= size
;
6217 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6218 /* regs dump ABI info */
6219 int size
= sizeof(u64
);
6221 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6223 if (data
->regs_intr
.regs
) {
6224 u64 mask
= event
->attr
.sample_regs_intr
;
6226 size
+= hweight64(mask
) * sizeof(u64
);
6229 header
->size
+= size
;
6232 if (sample_type
& PERF_SAMPLE_PHYS_ADDR
)
6233 data
->phys_addr
= perf_virt_to_phys(data
->addr
);
6236 static void __always_inline
6237 __perf_event_output(struct perf_event
*event
,
6238 struct perf_sample_data
*data
,
6239 struct pt_regs
*regs
,
6240 int (*output_begin
)(struct perf_output_handle
*,
6241 struct perf_event
*,
6244 struct perf_output_handle handle
;
6245 struct perf_event_header header
;
6247 /* protect the callchain buffers */
6250 perf_prepare_sample(&header
, data
, event
, regs
);
6252 if (output_begin(&handle
, event
, header
.size
))
6255 perf_output_sample(&handle
, &header
, data
, event
);
6257 perf_output_end(&handle
);
6264 perf_event_output_forward(struct perf_event
*event
,
6265 struct perf_sample_data
*data
,
6266 struct pt_regs
*regs
)
6268 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6272 perf_event_output_backward(struct perf_event
*event
,
6273 struct perf_sample_data
*data
,
6274 struct pt_regs
*regs
)
6276 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6280 perf_event_output(struct perf_event
*event
,
6281 struct perf_sample_data
*data
,
6282 struct pt_regs
*regs
)
6284 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6291 struct perf_read_event
{
6292 struct perf_event_header header
;
6299 perf_event_read_event(struct perf_event
*event
,
6300 struct task_struct
*task
)
6302 struct perf_output_handle handle
;
6303 struct perf_sample_data sample
;
6304 struct perf_read_event read_event
= {
6306 .type
= PERF_RECORD_READ
,
6308 .size
= sizeof(read_event
) + event
->read_size
,
6310 .pid
= perf_event_pid(event
, task
),
6311 .tid
= perf_event_tid(event
, task
),
6315 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6316 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6320 perf_output_put(&handle
, read_event
);
6321 perf_output_read(&handle
, event
);
6322 perf_event__output_id_sample(event
, &handle
, &sample
);
6324 perf_output_end(&handle
);
6327 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6330 perf_iterate_ctx(struct perf_event_context
*ctx
,
6331 perf_iterate_f output
,
6332 void *data
, bool all
)
6334 struct perf_event
*event
;
6336 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6338 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6340 if (!event_filter_match(event
))
6344 output(event
, data
);
6348 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6350 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6351 struct perf_event
*event
;
6353 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6355 * Skip events that are not fully formed yet; ensure that
6356 * if we observe event->ctx, both event and ctx will be
6357 * complete enough. See perf_install_in_context().
6359 if (!smp_load_acquire(&event
->ctx
))
6362 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6364 if (!event_filter_match(event
))
6366 output(event
, data
);
6371 * Iterate all events that need to receive side-band events.
6373 * For new callers; ensure that account_pmu_sb_event() includes
6374 * your event, otherwise it might not get delivered.
6377 perf_iterate_sb(perf_iterate_f output
, void *data
,
6378 struct perf_event_context
*task_ctx
)
6380 struct perf_event_context
*ctx
;
6387 * If we have task_ctx != NULL we only notify the task context itself.
6388 * The task_ctx is set only for EXIT events before releasing task
6392 perf_iterate_ctx(task_ctx
, output
, data
, false);
6396 perf_iterate_sb_cpu(output
, data
);
6398 for_each_task_context_nr(ctxn
) {
6399 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6401 perf_iterate_ctx(ctx
, output
, data
, false);
6409 * Clear all file-based filters at exec, they'll have to be
6410 * re-instated when/if these objects are mmapped again.
6412 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6414 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6415 struct perf_addr_filter
*filter
;
6416 unsigned int restart
= 0, count
= 0;
6417 unsigned long flags
;
6419 if (!has_addr_filter(event
))
6422 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6423 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6424 if (filter
->inode
) {
6425 event
->addr_filters_offs
[count
] = 0;
6433 event
->addr_filters_gen
++;
6434 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6437 perf_event_stop(event
, 1);
6440 void perf_event_exec(void)
6442 struct perf_event_context
*ctx
;
6446 for_each_task_context_nr(ctxn
) {
6447 ctx
= current
->perf_event_ctxp
[ctxn
];
6451 perf_event_enable_on_exec(ctxn
);
6453 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6459 struct remote_output
{
6460 struct ring_buffer
*rb
;
6464 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6466 struct perf_event
*parent
= event
->parent
;
6467 struct remote_output
*ro
= data
;
6468 struct ring_buffer
*rb
= ro
->rb
;
6469 struct stop_event_data sd
= {
6473 if (!has_aux(event
))
6480 * In case of inheritance, it will be the parent that links to the
6481 * ring-buffer, but it will be the child that's actually using it.
6483 * We are using event::rb to determine if the event should be stopped,
6484 * however this may race with ring_buffer_attach() (through set_output),
6485 * which will make us skip the event that actually needs to be stopped.
6486 * So ring_buffer_attach() has to stop an aux event before re-assigning
6489 if (rcu_dereference(parent
->rb
) == rb
)
6490 ro
->err
= __perf_event_stop(&sd
);
6493 static int __perf_pmu_output_stop(void *info
)
6495 struct perf_event
*event
= info
;
6496 struct pmu
*pmu
= event
->pmu
;
6497 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6498 struct remote_output ro
= {
6503 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6504 if (cpuctx
->task_ctx
)
6505 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6512 static void perf_pmu_output_stop(struct perf_event
*event
)
6514 struct perf_event
*iter
;
6519 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6521 * For per-CPU events, we need to make sure that neither they
6522 * nor their children are running; for cpu==-1 events it's
6523 * sufficient to stop the event itself if it's active, since
6524 * it can't have children.
6528 cpu
= READ_ONCE(iter
->oncpu
);
6533 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6534 if (err
== -EAGAIN
) {
6543 * task tracking -- fork/exit
6545 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6548 struct perf_task_event
{
6549 struct task_struct
*task
;
6550 struct perf_event_context
*task_ctx
;
6553 struct perf_event_header header
;
6563 static int perf_event_task_match(struct perf_event
*event
)
6565 return event
->attr
.comm
|| event
->attr
.mmap
||
6566 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6570 static void perf_event_task_output(struct perf_event
*event
,
6573 struct perf_task_event
*task_event
= data
;
6574 struct perf_output_handle handle
;
6575 struct perf_sample_data sample
;
6576 struct task_struct
*task
= task_event
->task
;
6577 int ret
, size
= task_event
->event_id
.header
.size
;
6579 if (!perf_event_task_match(event
))
6582 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6584 ret
= perf_output_begin(&handle
, event
,
6585 task_event
->event_id
.header
.size
);
6589 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6590 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6592 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6593 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6595 task_event
->event_id
.time
= perf_event_clock(event
);
6597 perf_output_put(&handle
, task_event
->event_id
);
6599 perf_event__output_id_sample(event
, &handle
, &sample
);
6601 perf_output_end(&handle
);
6603 task_event
->event_id
.header
.size
= size
;
6606 static void perf_event_task(struct task_struct
*task
,
6607 struct perf_event_context
*task_ctx
,
6610 struct perf_task_event task_event
;
6612 if (!atomic_read(&nr_comm_events
) &&
6613 !atomic_read(&nr_mmap_events
) &&
6614 !atomic_read(&nr_task_events
))
6617 task_event
= (struct perf_task_event
){
6619 .task_ctx
= task_ctx
,
6622 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6624 .size
= sizeof(task_event
.event_id
),
6634 perf_iterate_sb(perf_event_task_output
,
6639 void perf_event_fork(struct task_struct
*task
)
6641 perf_event_task(task
, NULL
, 1);
6642 perf_event_namespaces(task
);
6649 struct perf_comm_event
{
6650 struct task_struct
*task
;
6655 struct perf_event_header header
;
6662 static int perf_event_comm_match(struct perf_event
*event
)
6664 return event
->attr
.comm
;
6667 static void perf_event_comm_output(struct perf_event
*event
,
6670 struct perf_comm_event
*comm_event
= data
;
6671 struct perf_output_handle handle
;
6672 struct perf_sample_data sample
;
6673 int size
= comm_event
->event_id
.header
.size
;
6676 if (!perf_event_comm_match(event
))
6679 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6680 ret
= perf_output_begin(&handle
, event
,
6681 comm_event
->event_id
.header
.size
);
6686 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6687 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6689 perf_output_put(&handle
, comm_event
->event_id
);
6690 __output_copy(&handle
, comm_event
->comm
,
6691 comm_event
->comm_size
);
6693 perf_event__output_id_sample(event
, &handle
, &sample
);
6695 perf_output_end(&handle
);
6697 comm_event
->event_id
.header
.size
= size
;
6700 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6702 char comm
[TASK_COMM_LEN
];
6705 memset(comm
, 0, sizeof(comm
));
6706 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6707 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6709 comm_event
->comm
= comm
;
6710 comm_event
->comm_size
= size
;
6712 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6714 perf_iterate_sb(perf_event_comm_output
,
6719 void perf_event_comm(struct task_struct
*task
, bool exec
)
6721 struct perf_comm_event comm_event
;
6723 if (!atomic_read(&nr_comm_events
))
6726 comm_event
= (struct perf_comm_event
){
6732 .type
= PERF_RECORD_COMM
,
6733 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6741 perf_event_comm_event(&comm_event
);
6745 * namespaces tracking
6748 struct perf_namespaces_event
{
6749 struct task_struct
*task
;
6752 struct perf_event_header header
;
6757 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
6761 static int perf_event_namespaces_match(struct perf_event
*event
)
6763 return event
->attr
.namespaces
;
6766 static void perf_event_namespaces_output(struct perf_event
*event
,
6769 struct perf_namespaces_event
*namespaces_event
= data
;
6770 struct perf_output_handle handle
;
6771 struct perf_sample_data sample
;
6772 u16 header_size
= namespaces_event
->event_id
.header
.size
;
6775 if (!perf_event_namespaces_match(event
))
6778 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
6780 ret
= perf_output_begin(&handle
, event
,
6781 namespaces_event
->event_id
.header
.size
);
6785 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
6786 namespaces_event
->task
);
6787 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
6788 namespaces_event
->task
);
6790 perf_output_put(&handle
, namespaces_event
->event_id
);
6792 perf_event__output_id_sample(event
, &handle
, &sample
);
6794 perf_output_end(&handle
);
6796 namespaces_event
->event_id
.header
.size
= header_size
;
6799 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
6800 struct task_struct
*task
,
6801 const struct proc_ns_operations
*ns_ops
)
6803 struct path ns_path
;
6804 struct inode
*ns_inode
;
6807 error
= ns_get_path(&ns_path
, task
, ns_ops
);
6809 ns_inode
= ns_path
.dentry
->d_inode
;
6810 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
6811 ns_link_info
->ino
= ns_inode
->i_ino
;
6816 void perf_event_namespaces(struct task_struct
*task
)
6818 struct perf_namespaces_event namespaces_event
;
6819 struct perf_ns_link_info
*ns_link_info
;
6821 if (!atomic_read(&nr_namespaces_events
))
6824 namespaces_event
= (struct perf_namespaces_event
){
6828 .type
= PERF_RECORD_NAMESPACES
,
6830 .size
= sizeof(namespaces_event
.event_id
),
6834 .nr_namespaces
= NR_NAMESPACES
,
6835 /* .link_info[NR_NAMESPACES] */
6839 ns_link_info
= namespaces_event
.event_id
.link_info
;
6841 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
6842 task
, &mntns_operations
);
6844 #ifdef CONFIG_USER_NS
6845 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
6846 task
, &userns_operations
);
6848 #ifdef CONFIG_NET_NS
6849 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
6850 task
, &netns_operations
);
6852 #ifdef CONFIG_UTS_NS
6853 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
6854 task
, &utsns_operations
);
6856 #ifdef CONFIG_IPC_NS
6857 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
6858 task
, &ipcns_operations
);
6860 #ifdef CONFIG_PID_NS
6861 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
6862 task
, &pidns_operations
);
6864 #ifdef CONFIG_CGROUPS
6865 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
6866 task
, &cgroupns_operations
);
6869 perf_iterate_sb(perf_event_namespaces_output
,
6878 struct perf_mmap_event
{
6879 struct vm_area_struct
*vma
;
6881 const char *file_name
;
6889 struct perf_event_header header
;
6899 static int perf_event_mmap_match(struct perf_event
*event
,
6902 struct perf_mmap_event
*mmap_event
= data
;
6903 struct vm_area_struct
*vma
= mmap_event
->vma
;
6904 int executable
= vma
->vm_flags
& VM_EXEC
;
6906 return (!executable
&& event
->attr
.mmap_data
) ||
6907 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6910 static void perf_event_mmap_output(struct perf_event
*event
,
6913 struct perf_mmap_event
*mmap_event
= data
;
6914 struct perf_output_handle handle
;
6915 struct perf_sample_data sample
;
6916 int size
= mmap_event
->event_id
.header
.size
;
6919 if (!perf_event_mmap_match(event
, data
))
6922 if (event
->attr
.mmap2
) {
6923 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6924 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6925 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6926 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6927 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6928 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6929 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6932 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6933 ret
= perf_output_begin(&handle
, event
,
6934 mmap_event
->event_id
.header
.size
);
6938 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6939 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6941 perf_output_put(&handle
, mmap_event
->event_id
);
6943 if (event
->attr
.mmap2
) {
6944 perf_output_put(&handle
, mmap_event
->maj
);
6945 perf_output_put(&handle
, mmap_event
->min
);
6946 perf_output_put(&handle
, mmap_event
->ino
);
6947 perf_output_put(&handle
, mmap_event
->ino_generation
);
6948 perf_output_put(&handle
, mmap_event
->prot
);
6949 perf_output_put(&handle
, mmap_event
->flags
);
6952 __output_copy(&handle
, mmap_event
->file_name
,
6953 mmap_event
->file_size
);
6955 perf_event__output_id_sample(event
, &handle
, &sample
);
6957 perf_output_end(&handle
);
6959 mmap_event
->event_id
.header
.size
= size
;
6962 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6964 struct vm_area_struct
*vma
= mmap_event
->vma
;
6965 struct file
*file
= vma
->vm_file
;
6966 int maj
= 0, min
= 0;
6967 u64 ino
= 0, gen
= 0;
6968 u32 prot
= 0, flags
= 0;
6974 if (vma
->vm_flags
& VM_READ
)
6976 if (vma
->vm_flags
& VM_WRITE
)
6978 if (vma
->vm_flags
& VM_EXEC
)
6981 if (vma
->vm_flags
& VM_MAYSHARE
)
6984 flags
= MAP_PRIVATE
;
6986 if (vma
->vm_flags
& VM_DENYWRITE
)
6987 flags
|= MAP_DENYWRITE
;
6988 if (vma
->vm_flags
& VM_MAYEXEC
)
6989 flags
|= MAP_EXECUTABLE
;
6990 if (vma
->vm_flags
& VM_LOCKED
)
6991 flags
|= MAP_LOCKED
;
6992 if (vma
->vm_flags
& VM_HUGETLB
)
6993 flags
|= MAP_HUGETLB
;
6996 struct inode
*inode
;
6999 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
7005 * d_path() works from the end of the rb backwards, so we
7006 * need to add enough zero bytes after the string to handle
7007 * the 64bit alignment we do later.
7009 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
7014 inode
= file_inode(vma
->vm_file
);
7015 dev
= inode
->i_sb
->s_dev
;
7017 gen
= inode
->i_generation
;
7023 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
7024 name
= (char *) vma
->vm_ops
->name(vma
);
7029 name
= (char *)arch_vma_name(vma
);
7033 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
7034 vma
->vm_end
>= vma
->vm_mm
->brk
) {
7038 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
7039 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
7049 strlcpy(tmp
, name
, sizeof(tmp
));
7053 * Since our buffer works in 8 byte units we need to align our string
7054 * size to a multiple of 8. However, we must guarantee the tail end is
7055 * zero'd out to avoid leaking random bits to userspace.
7057 size
= strlen(name
)+1;
7058 while (!IS_ALIGNED(size
, sizeof(u64
)))
7059 name
[size
++] = '\0';
7061 mmap_event
->file_name
= name
;
7062 mmap_event
->file_size
= size
;
7063 mmap_event
->maj
= maj
;
7064 mmap_event
->min
= min
;
7065 mmap_event
->ino
= ino
;
7066 mmap_event
->ino_generation
= gen
;
7067 mmap_event
->prot
= prot
;
7068 mmap_event
->flags
= flags
;
7070 if (!(vma
->vm_flags
& VM_EXEC
))
7071 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
7073 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
7075 perf_iterate_sb(perf_event_mmap_output
,
7083 * Check whether inode and address range match filter criteria.
7085 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
7086 struct file
*file
, unsigned long offset
,
7089 if (filter
->inode
!= file_inode(file
))
7092 if (filter
->offset
> offset
+ size
)
7095 if (filter
->offset
+ filter
->size
< offset
)
7101 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
7103 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7104 struct vm_area_struct
*vma
= data
;
7105 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
7106 struct file
*file
= vma
->vm_file
;
7107 struct perf_addr_filter
*filter
;
7108 unsigned int restart
= 0, count
= 0;
7110 if (!has_addr_filter(event
))
7116 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7117 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7118 if (perf_addr_filter_match(filter
, file
, off
,
7119 vma
->vm_end
- vma
->vm_start
)) {
7120 event
->addr_filters_offs
[count
] = vma
->vm_start
;
7128 event
->addr_filters_gen
++;
7129 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7132 perf_event_stop(event
, 1);
7136 * Adjust all task's events' filters to the new vma
7138 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
7140 struct perf_event_context
*ctx
;
7144 * Data tracing isn't supported yet and as such there is no need
7145 * to keep track of anything that isn't related to executable code:
7147 if (!(vma
->vm_flags
& VM_EXEC
))
7151 for_each_task_context_nr(ctxn
) {
7152 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7156 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7161 void perf_event_mmap(struct vm_area_struct
*vma
)
7163 struct perf_mmap_event mmap_event
;
7165 if (!atomic_read(&nr_mmap_events
))
7168 mmap_event
= (struct perf_mmap_event
){
7174 .type
= PERF_RECORD_MMAP
,
7175 .misc
= PERF_RECORD_MISC_USER
,
7180 .start
= vma
->vm_start
,
7181 .len
= vma
->vm_end
- vma
->vm_start
,
7182 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7184 /* .maj (attr_mmap2 only) */
7185 /* .min (attr_mmap2 only) */
7186 /* .ino (attr_mmap2 only) */
7187 /* .ino_generation (attr_mmap2 only) */
7188 /* .prot (attr_mmap2 only) */
7189 /* .flags (attr_mmap2 only) */
7192 perf_addr_filters_adjust(vma
);
7193 perf_event_mmap_event(&mmap_event
);
7196 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7197 unsigned long size
, u64 flags
)
7199 struct perf_output_handle handle
;
7200 struct perf_sample_data sample
;
7201 struct perf_aux_event
{
7202 struct perf_event_header header
;
7208 .type
= PERF_RECORD_AUX
,
7210 .size
= sizeof(rec
),
7218 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7219 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7224 perf_output_put(&handle
, rec
);
7225 perf_event__output_id_sample(event
, &handle
, &sample
);
7227 perf_output_end(&handle
);
7231 * Lost/dropped samples logging
7233 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7235 struct perf_output_handle handle
;
7236 struct perf_sample_data sample
;
7240 struct perf_event_header header
;
7242 } lost_samples_event
= {
7244 .type
= PERF_RECORD_LOST_SAMPLES
,
7246 .size
= sizeof(lost_samples_event
),
7251 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7253 ret
= perf_output_begin(&handle
, event
,
7254 lost_samples_event
.header
.size
);
7258 perf_output_put(&handle
, lost_samples_event
);
7259 perf_event__output_id_sample(event
, &handle
, &sample
);
7260 perf_output_end(&handle
);
7264 * context_switch tracking
7267 struct perf_switch_event
{
7268 struct task_struct
*task
;
7269 struct task_struct
*next_prev
;
7272 struct perf_event_header header
;
7278 static int perf_event_switch_match(struct perf_event
*event
)
7280 return event
->attr
.context_switch
;
7283 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7285 struct perf_switch_event
*se
= data
;
7286 struct perf_output_handle handle
;
7287 struct perf_sample_data sample
;
7290 if (!perf_event_switch_match(event
))
7293 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7294 if (event
->ctx
->task
) {
7295 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7296 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7298 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7299 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7300 se
->event_id
.next_prev_pid
=
7301 perf_event_pid(event
, se
->next_prev
);
7302 se
->event_id
.next_prev_tid
=
7303 perf_event_tid(event
, se
->next_prev
);
7306 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7308 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7312 if (event
->ctx
->task
)
7313 perf_output_put(&handle
, se
->event_id
.header
);
7315 perf_output_put(&handle
, se
->event_id
);
7317 perf_event__output_id_sample(event
, &handle
, &sample
);
7319 perf_output_end(&handle
);
7322 static void perf_event_switch(struct task_struct
*task
,
7323 struct task_struct
*next_prev
, bool sched_in
)
7325 struct perf_switch_event switch_event
;
7327 /* N.B. caller checks nr_switch_events != 0 */
7329 switch_event
= (struct perf_switch_event
){
7331 .next_prev
= next_prev
,
7335 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7338 /* .next_prev_pid */
7339 /* .next_prev_tid */
7343 perf_iterate_sb(perf_event_switch_output
,
7349 * IRQ throttle logging
7352 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7354 struct perf_output_handle handle
;
7355 struct perf_sample_data sample
;
7359 struct perf_event_header header
;
7363 } throttle_event
= {
7365 .type
= PERF_RECORD_THROTTLE
,
7367 .size
= sizeof(throttle_event
),
7369 .time
= perf_event_clock(event
),
7370 .id
= primary_event_id(event
),
7371 .stream_id
= event
->id
,
7375 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7377 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7379 ret
= perf_output_begin(&handle
, event
,
7380 throttle_event
.header
.size
);
7384 perf_output_put(&handle
, throttle_event
);
7385 perf_event__output_id_sample(event
, &handle
, &sample
);
7386 perf_output_end(&handle
);
7389 void perf_event_itrace_started(struct perf_event
*event
)
7391 event
->attach_state
|= PERF_ATTACH_ITRACE
;
7394 static void perf_log_itrace_start(struct perf_event
*event
)
7396 struct perf_output_handle handle
;
7397 struct perf_sample_data sample
;
7398 struct perf_aux_event
{
7399 struct perf_event_header header
;
7406 event
= event
->parent
;
7408 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7409 event
->attach_state
& PERF_ATTACH_ITRACE
)
7412 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7413 rec
.header
.misc
= 0;
7414 rec
.header
.size
= sizeof(rec
);
7415 rec
.pid
= perf_event_pid(event
, current
);
7416 rec
.tid
= perf_event_tid(event
, current
);
7418 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7419 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7424 perf_output_put(&handle
, rec
);
7425 perf_event__output_id_sample(event
, &handle
, &sample
);
7427 perf_output_end(&handle
);
7431 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7433 struct hw_perf_event
*hwc
= &event
->hw
;
7437 seq
= __this_cpu_read(perf_throttled_seq
);
7438 if (seq
!= hwc
->interrupts_seq
) {
7439 hwc
->interrupts_seq
= seq
;
7440 hwc
->interrupts
= 1;
7443 if (unlikely(throttle
7444 && hwc
->interrupts
>= max_samples_per_tick
)) {
7445 __this_cpu_inc(perf_throttled_count
);
7446 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7447 hwc
->interrupts
= MAX_INTERRUPTS
;
7448 perf_log_throttle(event
, 0);
7453 if (event
->attr
.freq
) {
7454 u64 now
= perf_clock();
7455 s64 delta
= now
- hwc
->freq_time_stamp
;
7457 hwc
->freq_time_stamp
= now
;
7459 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7460 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7466 int perf_event_account_interrupt(struct perf_event
*event
)
7468 return __perf_event_account_interrupt(event
, 1);
7472 * Generic event overflow handling, sampling.
7475 static int __perf_event_overflow(struct perf_event
*event
,
7476 int throttle
, struct perf_sample_data
*data
,
7477 struct pt_regs
*regs
)
7479 int events
= atomic_read(&event
->event_limit
);
7483 * Non-sampling counters might still use the PMI to fold short
7484 * hardware counters, ignore those.
7486 if (unlikely(!is_sampling_event(event
)))
7489 ret
= __perf_event_account_interrupt(event
, throttle
);
7492 * XXX event_limit might not quite work as expected on inherited
7496 event
->pending_kill
= POLL_IN
;
7497 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7499 event
->pending_kill
= POLL_HUP
;
7501 perf_event_disable_inatomic(event
);
7504 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7506 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7507 event
->pending_wakeup
= 1;
7508 irq_work_queue(&event
->pending
);
7514 int perf_event_overflow(struct perf_event
*event
,
7515 struct perf_sample_data
*data
,
7516 struct pt_regs
*regs
)
7518 return __perf_event_overflow(event
, 1, data
, regs
);
7522 * Generic software event infrastructure
7525 struct swevent_htable
{
7526 struct swevent_hlist
*swevent_hlist
;
7527 struct mutex hlist_mutex
;
7530 /* Recursion avoidance in each contexts */
7531 int recursion
[PERF_NR_CONTEXTS
];
7534 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7537 * We directly increment event->count and keep a second value in
7538 * event->hw.period_left to count intervals. This period event
7539 * is kept in the range [-sample_period, 0] so that we can use the
7543 u64
perf_swevent_set_period(struct perf_event
*event
)
7545 struct hw_perf_event
*hwc
= &event
->hw
;
7546 u64 period
= hwc
->last_period
;
7550 hwc
->last_period
= hwc
->sample_period
;
7553 old
= val
= local64_read(&hwc
->period_left
);
7557 nr
= div64_u64(period
+ val
, period
);
7558 offset
= nr
* period
;
7560 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7566 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7567 struct perf_sample_data
*data
,
7568 struct pt_regs
*regs
)
7570 struct hw_perf_event
*hwc
= &event
->hw
;
7574 overflow
= perf_swevent_set_period(event
);
7576 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7579 for (; overflow
; overflow
--) {
7580 if (__perf_event_overflow(event
, throttle
,
7583 * We inhibit the overflow from happening when
7584 * hwc->interrupts == MAX_INTERRUPTS.
7592 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7593 struct perf_sample_data
*data
,
7594 struct pt_regs
*regs
)
7596 struct hw_perf_event
*hwc
= &event
->hw
;
7598 local64_add(nr
, &event
->count
);
7603 if (!is_sampling_event(event
))
7606 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7608 return perf_swevent_overflow(event
, 1, data
, regs
);
7610 data
->period
= event
->hw
.last_period
;
7612 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7613 return perf_swevent_overflow(event
, 1, data
, regs
);
7615 if (local64_add_negative(nr
, &hwc
->period_left
))
7618 perf_swevent_overflow(event
, 0, data
, regs
);
7621 static int perf_exclude_event(struct perf_event
*event
,
7622 struct pt_regs
*regs
)
7624 if (event
->hw
.state
& PERF_HES_STOPPED
)
7628 if (event
->attr
.exclude_user
&& user_mode(regs
))
7631 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7638 static int perf_swevent_match(struct perf_event
*event
,
7639 enum perf_type_id type
,
7641 struct perf_sample_data
*data
,
7642 struct pt_regs
*regs
)
7644 if (event
->attr
.type
!= type
)
7647 if (event
->attr
.config
!= event_id
)
7650 if (perf_exclude_event(event
, regs
))
7656 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7658 u64 val
= event_id
| (type
<< 32);
7660 return hash_64(val
, SWEVENT_HLIST_BITS
);
7663 static inline struct hlist_head
*
7664 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7666 u64 hash
= swevent_hash(type
, event_id
);
7668 return &hlist
->heads
[hash
];
7671 /* For the read side: events when they trigger */
7672 static inline struct hlist_head
*
7673 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7675 struct swevent_hlist
*hlist
;
7677 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7681 return __find_swevent_head(hlist
, type
, event_id
);
7684 /* For the event head insertion and removal in the hlist */
7685 static inline struct hlist_head
*
7686 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7688 struct swevent_hlist
*hlist
;
7689 u32 event_id
= event
->attr
.config
;
7690 u64 type
= event
->attr
.type
;
7693 * Event scheduling is always serialized against hlist allocation
7694 * and release. Which makes the protected version suitable here.
7695 * The context lock guarantees that.
7697 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7698 lockdep_is_held(&event
->ctx
->lock
));
7702 return __find_swevent_head(hlist
, type
, event_id
);
7705 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7707 struct perf_sample_data
*data
,
7708 struct pt_regs
*regs
)
7710 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7711 struct perf_event
*event
;
7712 struct hlist_head
*head
;
7715 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7719 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7720 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7721 perf_swevent_event(event
, nr
, data
, regs
);
7727 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7729 int perf_swevent_get_recursion_context(void)
7731 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7733 return get_recursion_context(swhash
->recursion
);
7735 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7737 void perf_swevent_put_recursion_context(int rctx
)
7739 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7741 put_recursion_context(swhash
->recursion
, rctx
);
7744 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7746 struct perf_sample_data data
;
7748 if (WARN_ON_ONCE(!regs
))
7751 perf_sample_data_init(&data
, addr
, 0);
7752 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7755 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7759 preempt_disable_notrace();
7760 rctx
= perf_swevent_get_recursion_context();
7761 if (unlikely(rctx
< 0))
7764 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7766 perf_swevent_put_recursion_context(rctx
);
7768 preempt_enable_notrace();
7771 static void perf_swevent_read(struct perf_event
*event
)
7775 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7777 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7778 struct hw_perf_event
*hwc
= &event
->hw
;
7779 struct hlist_head
*head
;
7781 if (is_sampling_event(event
)) {
7782 hwc
->last_period
= hwc
->sample_period
;
7783 perf_swevent_set_period(event
);
7786 hwc
->state
= !(flags
& PERF_EF_START
);
7788 head
= find_swevent_head(swhash
, event
);
7789 if (WARN_ON_ONCE(!head
))
7792 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7793 perf_event_update_userpage(event
);
7798 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7800 hlist_del_rcu(&event
->hlist_entry
);
7803 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7805 event
->hw
.state
= 0;
7808 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7810 event
->hw
.state
= PERF_HES_STOPPED
;
7813 /* Deref the hlist from the update side */
7814 static inline struct swevent_hlist
*
7815 swevent_hlist_deref(struct swevent_htable
*swhash
)
7817 return rcu_dereference_protected(swhash
->swevent_hlist
,
7818 lockdep_is_held(&swhash
->hlist_mutex
));
7821 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7823 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7828 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7829 kfree_rcu(hlist
, rcu_head
);
7832 static void swevent_hlist_put_cpu(int cpu
)
7834 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7836 mutex_lock(&swhash
->hlist_mutex
);
7838 if (!--swhash
->hlist_refcount
)
7839 swevent_hlist_release(swhash
);
7841 mutex_unlock(&swhash
->hlist_mutex
);
7844 static void swevent_hlist_put(void)
7848 for_each_possible_cpu(cpu
)
7849 swevent_hlist_put_cpu(cpu
);
7852 static int swevent_hlist_get_cpu(int cpu
)
7854 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7857 mutex_lock(&swhash
->hlist_mutex
);
7858 if (!swevent_hlist_deref(swhash
) &&
7859 cpumask_test_cpu(cpu
, perf_online_mask
)) {
7860 struct swevent_hlist
*hlist
;
7862 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7867 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7869 swhash
->hlist_refcount
++;
7871 mutex_unlock(&swhash
->hlist_mutex
);
7876 static int swevent_hlist_get(void)
7878 int err
, cpu
, failed_cpu
;
7880 mutex_lock(&pmus_lock
);
7881 for_each_possible_cpu(cpu
) {
7882 err
= swevent_hlist_get_cpu(cpu
);
7888 mutex_unlock(&pmus_lock
);
7891 for_each_possible_cpu(cpu
) {
7892 if (cpu
== failed_cpu
)
7894 swevent_hlist_put_cpu(cpu
);
7896 mutex_unlock(&pmus_lock
);
7900 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7902 static void sw_perf_event_destroy(struct perf_event
*event
)
7904 u64 event_id
= event
->attr
.config
;
7906 WARN_ON(event
->parent
);
7908 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7909 swevent_hlist_put();
7912 static int perf_swevent_init(struct perf_event
*event
)
7914 u64 event_id
= event
->attr
.config
;
7916 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7920 * no branch sampling for software events
7922 if (has_branch_stack(event
))
7926 case PERF_COUNT_SW_CPU_CLOCK
:
7927 case PERF_COUNT_SW_TASK_CLOCK
:
7934 if (event_id
>= PERF_COUNT_SW_MAX
)
7937 if (!event
->parent
) {
7940 err
= swevent_hlist_get();
7944 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7945 event
->destroy
= sw_perf_event_destroy
;
7951 static struct pmu perf_swevent
= {
7952 .task_ctx_nr
= perf_sw_context
,
7954 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7956 .event_init
= perf_swevent_init
,
7957 .add
= perf_swevent_add
,
7958 .del
= perf_swevent_del
,
7959 .start
= perf_swevent_start
,
7960 .stop
= perf_swevent_stop
,
7961 .read
= perf_swevent_read
,
7964 #ifdef CONFIG_EVENT_TRACING
7966 static int perf_tp_filter_match(struct perf_event
*event
,
7967 struct perf_sample_data
*data
)
7969 void *record
= data
->raw
->frag
.data
;
7971 /* only top level events have filters set */
7973 event
= event
->parent
;
7975 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7980 static int perf_tp_event_match(struct perf_event
*event
,
7981 struct perf_sample_data
*data
,
7982 struct pt_regs
*regs
)
7984 if (event
->hw
.state
& PERF_HES_STOPPED
)
7987 * All tracepoints are from kernel-space.
7989 if (event
->attr
.exclude_kernel
)
7992 if (!perf_tp_filter_match(event
, data
))
7998 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7999 struct trace_event_call
*call
, u64 count
,
8000 struct pt_regs
*regs
, struct hlist_head
*head
,
8001 struct task_struct
*task
)
8003 struct bpf_prog
*prog
= call
->prog
;
8006 *(struct pt_regs
**)raw_data
= regs
;
8007 if (!trace_call_bpf(prog
, raw_data
) || hlist_empty(head
)) {
8008 perf_swevent_put_recursion_context(rctx
);
8012 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
8015 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
8017 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
8018 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
8019 struct task_struct
*task
, struct perf_event
*event
)
8021 struct perf_sample_data data
;
8023 struct perf_raw_record raw
= {
8030 perf_sample_data_init(&data
, 0, 0);
8033 perf_trace_buf_update(record
, event_type
);
8035 /* Use the given event instead of the hlist */
8037 if (perf_tp_event_match(event
, &data
, regs
))
8038 perf_swevent_event(event
, count
, &data
, regs
);
8040 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
8041 if (perf_tp_event_match(event
, &data
, regs
))
8042 perf_swevent_event(event
, count
, &data
, regs
);
8047 * If we got specified a target task, also iterate its context and
8048 * deliver this event there too.
8050 if (task
&& task
!= current
) {
8051 struct perf_event_context
*ctx
;
8052 struct trace_entry
*entry
= record
;
8055 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
8059 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
8060 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8062 if (event
->attr
.config
!= entry
->type
)
8064 if (perf_tp_event_match(event
, &data
, regs
))
8065 perf_swevent_event(event
, count
, &data
, regs
);
8071 perf_swevent_put_recursion_context(rctx
);
8073 EXPORT_SYMBOL_GPL(perf_tp_event
);
8075 static void tp_perf_event_destroy(struct perf_event
*event
)
8077 perf_trace_destroy(event
);
8080 static int perf_tp_event_init(struct perf_event
*event
)
8084 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8088 * no branch sampling for tracepoint events
8090 if (has_branch_stack(event
))
8093 err
= perf_trace_init(event
);
8097 event
->destroy
= tp_perf_event_destroy
;
8102 static struct pmu perf_tracepoint
= {
8103 .task_ctx_nr
= perf_sw_context
,
8105 .event_init
= perf_tp_event_init
,
8106 .add
= perf_trace_add
,
8107 .del
= perf_trace_del
,
8108 .start
= perf_swevent_start
,
8109 .stop
= perf_swevent_stop
,
8110 .read
= perf_swevent_read
,
8113 static inline void perf_tp_register(void)
8115 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
8118 static void perf_event_free_filter(struct perf_event
*event
)
8120 ftrace_profile_free_filter(event
);
8123 #ifdef CONFIG_BPF_SYSCALL
8124 static void bpf_overflow_handler(struct perf_event
*event
,
8125 struct perf_sample_data
*data
,
8126 struct pt_regs
*regs
)
8128 struct bpf_perf_event_data_kern ctx
= {
8135 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
8138 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
8141 __this_cpu_dec(bpf_prog_active
);
8146 event
->orig_overflow_handler(event
, data
, regs
);
8149 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8151 struct bpf_prog
*prog
;
8153 if (event
->overflow_handler_context
)
8154 /* hw breakpoint or kernel counter */
8160 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8162 return PTR_ERR(prog
);
8165 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8166 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8170 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8172 struct bpf_prog
*prog
= event
->prog
;
8177 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
8182 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8186 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8191 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8193 bool is_kprobe
, is_tracepoint
, is_syscall_tp
;
8194 struct bpf_prog
*prog
;
8196 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8197 return perf_event_set_bpf_handler(event
, prog_fd
);
8199 if (event
->tp_event
->prog
)
8202 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
8203 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
8204 is_syscall_tp
= is_syscall_trace_event(event
->tp_event
);
8205 if (!is_kprobe
&& !is_tracepoint
&& !is_syscall_tp
)
8206 /* bpf programs can only be attached to u/kprobe or tracepoint */
8209 prog
= bpf_prog_get(prog_fd
);
8211 return PTR_ERR(prog
);
8213 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
8214 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
) ||
8215 (is_syscall_tp
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
8216 /* valid fd, but invalid bpf program type */
8221 if (is_tracepoint
|| is_syscall_tp
) {
8222 int off
= trace_event_get_offsets(event
->tp_event
);
8224 if (prog
->aux
->max_ctx_offset
> off
) {
8229 event
->tp_event
->prog
= prog
;
8230 event
->tp_event
->bpf_prog_owner
= event
;
8235 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8237 struct bpf_prog
*prog
;
8239 perf_event_free_bpf_handler(event
);
8241 if (!event
->tp_event
)
8244 prog
= event
->tp_event
->prog
;
8245 if (prog
&& event
->tp_event
->bpf_prog_owner
== event
) {
8246 event
->tp_event
->prog
= NULL
;
8253 static inline void perf_tp_register(void)
8257 static void perf_event_free_filter(struct perf_event
*event
)
8261 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8266 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8269 #endif /* CONFIG_EVENT_TRACING */
8271 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8272 void perf_bp_event(struct perf_event
*bp
, void *data
)
8274 struct perf_sample_data sample
;
8275 struct pt_regs
*regs
= data
;
8277 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
8279 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
8280 perf_swevent_event(bp
, 1, &sample
, regs
);
8285 * Allocate a new address filter
8287 static struct perf_addr_filter
*
8288 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
8290 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8291 struct perf_addr_filter
*filter
;
8293 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8297 INIT_LIST_HEAD(&filter
->entry
);
8298 list_add_tail(&filter
->entry
, filters
);
8303 static void free_filters_list(struct list_head
*filters
)
8305 struct perf_addr_filter
*filter
, *iter
;
8307 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8309 iput(filter
->inode
);
8310 list_del(&filter
->entry
);
8316 * Free existing address filters and optionally install new ones
8318 static void perf_addr_filters_splice(struct perf_event
*event
,
8319 struct list_head
*head
)
8321 unsigned long flags
;
8324 if (!has_addr_filter(event
))
8327 /* don't bother with children, they don't have their own filters */
8331 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8333 list_splice_init(&event
->addr_filters
.list
, &list
);
8335 list_splice(head
, &event
->addr_filters
.list
);
8337 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8339 free_filters_list(&list
);
8343 * Scan through mm's vmas and see if one of them matches the
8344 * @filter; if so, adjust filter's address range.
8345 * Called with mm::mmap_sem down for reading.
8347 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8348 struct mm_struct
*mm
)
8350 struct vm_area_struct
*vma
;
8352 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8353 struct file
*file
= vma
->vm_file
;
8354 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8355 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8360 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8363 return vma
->vm_start
;
8370 * Update event's address range filters based on the
8371 * task's existing mappings, if any.
8373 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8375 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8376 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8377 struct perf_addr_filter
*filter
;
8378 struct mm_struct
*mm
= NULL
;
8379 unsigned int count
= 0;
8380 unsigned long flags
;
8383 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8384 * will stop on the parent's child_mutex that our caller is also holding
8386 if (task
== TASK_TOMBSTONE
)
8389 if (!ifh
->nr_file_filters
)
8392 mm
= get_task_mm(event
->ctx
->task
);
8396 down_read(&mm
->mmap_sem
);
8398 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8399 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8400 event
->addr_filters_offs
[count
] = 0;
8403 * Adjust base offset if the filter is associated to a binary
8404 * that needs to be mapped:
8407 event
->addr_filters_offs
[count
] =
8408 perf_addr_filter_apply(filter
, mm
);
8413 event
->addr_filters_gen
++;
8414 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8416 up_read(&mm
->mmap_sem
);
8421 perf_event_stop(event
, 1);
8425 * Address range filtering: limiting the data to certain
8426 * instruction address ranges. Filters are ioctl()ed to us from
8427 * userspace as ascii strings.
8429 * Filter string format:
8432 * where ACTION is one of the
8433 * * "filter": limit the trace to this region
8434 * * "start": start tracing from this address
8435 * * "stop": stop tracing at this address/region;
8437 * * for kernel addresses: <start address>[/<size>]
8438 * * for object files: <start address>[/<size>]@</path/to/object/file>
8440 * if <size> is not specified, the range is treated as a single address.
8454 IF_STATE_ACTION
= 0,
8459 static const match_table_t if_tokens
= {
8460 { IF_ACT_FILTER
, "filter" },
8461 { IF_ACT_START
, "start" },
8462 { IF_ACT_STOP
, "stop" },
8463 { IF_SRC_FILE
, "%u/%u@%s" },
8464 { IF_SRC_KERNEL
, "%u/%u" },
8465 { IF_SRC_FILEADDR
, "%u@%s" },
8466 { IF_SRC_KERNELADDR
, "%u" },
8467 { IF_ACT_NONE
, NULL
},
8471 * Address filter string parser
8474 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8475 struct list_head
*filters
)
8477 struct perf_addr_filter
*filter
= NULL
;
8478 char *start
, *orig
, *filename
= NULL
;
8480 substring_t args
[MAX_OPT_ARGS
];
8481 int state
= IF_STATE_ACTION
, token
;
8482 unsigned int kernel
= 0;
8485 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8489 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8495 /* filter definition begins */
8496 if (state
== IF_STATE_ACTION
) {
8497 filter
= perf_addr_filter_new(event
, filters
);
8502 token
= match_token(start
, if_tokens
, args
);
8509 if (state
!= IF_STATE_ACTION
)
8512 state
= IF_STATE_SOURCE
;
8515 case IF_SRC_KERNELADDR
:
8519 case IF_SRC_FILEADDR
:
8521 if (state
!= IF_STATE_SOURCE
)
8524 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8528 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8532 if (filter
->range
) {
8534 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8539 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8540 int fpos
= filter
->range
? 2 : 1;
8542 filename
= match_strdup(&args
[fpos
]);
8549 state
= IF_STATE_END
;
8557 * Filter definition is fully parsed, validate and install it.
8558 * Make sure that it doesn't contradict itself or the event's
8561 if (state
== IF_STATE_END
) {
8563 if (kernel
&& event
->attr
.exclude_kernel
)
8571 * For now, we only support file-based filters
8572 * in per-task events; doing so for CPU-wide
8573 * events requires additional context switching
8574 * trickery, since same object code will be
8575 * mapped at different virtual addresses in
8576 * different processes.
8579 if (!event
->ctx
->task
)
8580 goto fail_free_name
;
8582 /* look up the path and grab its inode */
8583 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8585 goto fail_free_name
;
8587 filter
->inode
= igrab(d_inode(path
.dentry
));
8593 if (!filter
->inode
||
8594 !S_ISREG(filter
->inode
->i_mode
))
8595 /* free_filters_list() will iput() */
8598 event
->addr_filters
.nr_file_filters
++;
8601 /* ready to consume more filters */
8602 state
= IF_STATE_ACTION
;
8607 if (state
!= IF_STATE_ACTION
)
8617 free_filters_list(filters
);
8624 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8630 * Since this is called in perf_ioctl() path, we're already holding
8633 lockdep_assert_held(&event
->ctx
->mutex
);
8635 if (WARN_ON_ONCE(event
->parent
))
8638 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8640 goto fail_clear_files
;
8642 ret
= event
->pmu
->addr_filters_validate(&filters
);
8644 goto fail_free_filters
;
8646 /* remove existing filters, if any */
8647 perf_addr_filters_splice(event
, &filters
);
8649 /* install new filters */
8650 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8655 free_filters_list(&filters
);
8658 event
->addr_filters
.nr_file_filters
= 0;
8663 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8668 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8669 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8670 !has_addr_filter(event
))
8673 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8674 if (IS_ERR(filter_str
))
8675 return PTR_ERR(filter_str
);
8677 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8678 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8679 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
8681 else if (has_addr_filter(event
))
8682 ret
= perf_event_set_addr_filter(event
, filter_str
);
8689 * hrtimer based swevent callback
8692 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8694 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8695 struct perf_sample_data data
;
8696 struct pt_regs
*regs
;
8697 struct perf_event
*event
;
8700 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8702 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8703 return HRTIMER_NORESTART
;
8705 event
->pmu
->read(event
);
8707 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8708 regs
= get_irq_regs();
8710 if (regs
&& !perf_exclude_event(event
, regs
)) {
8711 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8712 if (__perf_event_overflow(event
, 1, &data
, regs
))
8713 ret
= HRTIMER_NORESTART
;
8716 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8717 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8722 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8724 struct hw_perf_event
*hwc
= &event
->hw
;
8727 if (!is_sampling_event(event
))
8730 period
= local64_read(&hwc
->period_left
);
8735 local64_set(&hwc
->period_left
, 0);
8737 period
= max_t(u64
, 10000, hwc
->sample_period
);
8739 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8740 HRTIMER_MODE_REL_PINNED
);
8743 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8745 struct hw_perf_event
*hwc
= &event
->hw
;
8747 if (is_sampling_event(event
)) {
8748 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8749 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8751 hrtimer_cancel(&hwc
->hrtimer
);
8755 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8757 struct hw_perf_event
*hwc
= &event
->hw
;
8759 if (!is_sampling_event(event
))
8762 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8763 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8766 * Since hrtimers have a fixed rate, we can do a static freq->period
8767 * mapping and avoid the whole period adjust feedback stuff.
8769 if (event
->attr
.freq
) {
8770 long freq
= event
->attr
.sample_freq
;
8772 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8773 hwc
->sample_period
= event
->attr
.sample_period
;
8774 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8775 hwc
->last_period
= hwc
->sample_period
;
8776 event
->attr
.freq
= 0;
8781 * Software event: cpu wall time clock
8784 static void cpu_clock_event_update(struct perf_event
*event
)
8789 now
= local_clock();
8790 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8791 local64_add(now
- prev
, &event
->count
);
8794 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8796 local64_set(&event
->hw
.prev_count
, local_clock());
8797 perf_swevent_start_hrtimer(event
);
8800 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8802 perf_swevent_cancel_hrtimer(event
);
8803 cpu_clock_event_update(event
);
8806 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8808 if (flags
& PERF_EF_START
)
8809 cpu_clock_event_start(event
, flags
);
8810 perf_event_update_userpage(event
);
8815 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8817 cpu_clock_event_stop(event
, flags
);
8820 static void cpu_clock_event_read(struct perf_event
*event
)
8822 cpu_clock_event_update(event
);
8825 static int cpu_clock_event_init(struct perf_event
*event
)
8827 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8830 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8834 * no branch sampling for software events
8836 if (has_branch_stack(event
))
8839 perf_swevent_init_hrtimer(event
);
8844 static struct pmu perf_cpu_clock
= {
8845 .task_ctx_nr
= perf_sw_context
,
8847 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8849 .event_init
= cpu_clock_event_init
,
8850 .add
= cpu_clock_event_add
,
8851 .del
= cpu_clock_event_del
,
8852 .start
= cpu_clock_event_start
,
8853 .stop
= cpu_clock_event_stop
,
8854 .read
= cpu_clock_event_read
,
8858 * Software event: task time clock
8861 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8866 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8868 local64_add(delta
, &event
->count
);
8871 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8873 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8874 perf_swevent_start_hrtimer(event
);
8877 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8879 perf_swevent_cancel_hrtimer(event
);
8880 task_clock_event_update(event
, event
->ctx
->time
);
8883 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8885 if (flags
& PERF_EF_START
)
8886 task_clock_event_start(event
, flags
);
8887 perf_event_update_userpage(event
);
8892 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8894 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8897 static void task_clock_event_read(struct perf_event
*event
)
8899 u64 now
= perf_clock();
8900 u64 delta
= now
- event
->ctx
->timestamp
;
8901 u64 time
= event
->ctx
->time
+ delta
;
8903 task_clock_event_update(event
, time
);
8906 static int task_clock_event_init(struct perf_event
*event
)
8908 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8911 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8915 * no branch sampling for software events
8917 if (has_branch_stack(event
))
8920 perf_swevent_init_hrtimer(event
);
8925 static struct pmu perf_task_clock
= {
8926 .task_ctx_nr
= perf_sw_context
,
8928 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8930 .event_init
= task_clock_event_init
,
8931 .add
= task_clock_event_add
,
8932 .del
= task_clock_event_del
,
8933 .start
= task_clock_event_start
,
8934 .stop
= task_clock_event_stop
,
8935 .read
= task_clock_event_read
,
8938 static void perf_pmu_nop_void(struct pmu
*pmu
)
8942 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8946 static int perf_pmu_nop_int(struct pmu
*pmu
)
8951 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8953 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8955 __this_cpu_write(nop_txn_flags
, flags
);
8957 if (flags
& ~PERF_PMU_TXN_ADD
)
8960 perf_pmu_disable(pmu
);
8963 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8965 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8967 __this_cpu_write(nop_txn_flags
, 0);
8969 if (flags
& ~PERF_PMU_TXN_ADD
)
8972 perf_pmu_enable(pmu
);
8976 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8978 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8980 __this_cpu_write(nop_txn_flags
, 0);
8982 if (flags
& ~PERF_PMU_TXN_ADD
)
8985 perf_pmu_enable(pmu
);
8988 static int perf_event_idx_default(struct perf_event
*event
)
8994 * Ensures all contexts with the same task_ctx_nr have the same
8995 * pmu_cpu_context too.
8997 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
9004 list_for_each_entry(pmu
, &pmus
, entry
) {
9005 if (pmu
->task_ctx_nr
== ctxn
)
9006 return pmu
->pmu_cpu_context
;
9012 static void free_pmu_context(struct pmu
*pmu
)
9015 * Static contexts such as perf_sw_context have a global lifetime
9016 * and may be shared between different PMUs. Avoid freeing them
9017 * when a single PMU is going away.
9019 if (pmu
->task_ctx_nr
> perf_invalid_context
)
9022 mutex_lock(&pmus_lock
);
9023 free_percpu(pmu
->pmu_cpu_context
);
9024 mutex_unlock(&pmus_lock
);
9028 * Let userspace know that this PMU supports address range filtering:
9030 static ssize_t
nr_addr_filters_show(struct device
*dev
,
9031 struct device_attribute
*attr
,
9034 struct pmu
*pmu
= dev_get_drvdata(dev
);
9036 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
9038 DEVICE_ATTR_RO(nr_addr_filters
);
9040 static struct idr pmu_idr
;
9043 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
9045 struct pmu
*pmu
= dev_get_drvdata(dev
);
9047 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
9049 static DEVICE_ATTR_RO(type
);
9052 perf_event_mux_interval_ms_show(struct device
*dev
,
9053 struct device_attribute
*attr
,
9056 struct pmu
*pmu
= dev_get_drvdata(dev
);
9058 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
9061 static DEFINE_MUTEX(mux_interval_mutex
);
9064 perf_event_mux_interval_ms_store(struct device
*dev
,
9065 struct device_attribute
*attr
,
9066 const char *buf
, size_t count
)
9068 struct pmu
*pmu
= dev_get_drvdata(dev
);
9069 int timer
, cpu
, ret
;
9071 ret
= kstrtoint(buf
, 0, &timer
);
9078 /* same value, noting to do */
9079 if (timer
== pmu
->hrtimer_interval_ms
)
9082 mutex_lock(&mux_interval_mutex
);
9083 pmu
->hrtimer_interval_ms
= timer
;
9085 /* update all cpuctx for this PMU */
9087 for_each_online_cpu(cpu
) {
9088 struct perf_cpu_context
*cpuctx
;
9089 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9090 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
9092 cpu_function_call(cpu
,
9093 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
9096 mutex_unlock(&mux_interval_mutex
);
9100 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
9102 static struct attribute
*pmu_dev_attrs
[] = {
9103 &dev_attr_type
.attr
,
9104 &dev_attr_perf_event_mux_interval_ms
.attr
,
9107 ATTRIBUTE_GROUPS(pmu_dev
);
9109 static int pmu_bus_running
;
9110 static struct bus_type pmu_bus
= {
9111 .name
= "event_source",
9112 .dev_groups
= pmu_dev_groups
,
9115 static void pmu_dev_release(struct device
*dev
)
9120 static int pmu_dev_alloc(struct pmu
*pmu
)
9124 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
9128 pmu
->dev
->groups
= pmu
->attr_groups
;
9129 device_initialize(pmu
->dev
);
9130 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
9134 dev_set_drvdata(pmu
->dev
, pmu
);
9135 pmu
->dev
->bus
= &pmu_bus
;
9136 pmu
->dev
->release
= pmu_dev_release
;
9137 ret
= device_add(pmu
->dev
);
9141 /* For PMUs with address filters, throw in an extra attribute: */
9142 if (pmu
->nr_addr_filters
)
9143 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9152 device_del(pmu
->dev
);
9155 put_device(pmu
->dev
);
9159 static struct lock_class_key cpuctx_mutex
;
9160 static struct lock_class_key cpuctx_lock
;
9162 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
9166 mutex_lock(&pmus_lock
);
9168 pmu
->pmu_disable_count
= alloc_percpu(int);
9169 if (!pmu
->pmu_disable_count
)
9178 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
9186 if (pmu_bus_running
) {
9187 ret
= pmu_dev_alloc(pmu
);
9193 if (pmu
->task_ctx_nr
== perf_hw_context
) {
9194 static int hw_context_taken
= 0;
9197 * Other than systems with heterogeneous CPUs, it never makes
9198 * sense for two PMUs to share perf_hw_context. PMUs which are
9199 * uncore must use perf_invalid_context.
9201 if (WARN_ON_ONCE(hw_context_taken
&&
9202 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
9203 pmu
->task_ctx_nr
= perf_invalid_context
;
9205 hw_context_taken
= 1;
9208 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
9209 if (pmu
->pmu_cpu_context
)
9210 goto got_cpu_context
;
9213 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
9214 if (!pmu
->pmu_cpu_context
)
9217 for_each_possible_cpu(cpu
) {
9218 struct perf_cpu_context
*cpuctx
;
9220 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9221 __perf_event_init_context(&cpuctx
->ctx
);
9222 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
9223 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
9224 cpuctx
->ctx
.pmu
= pmu
;
9225 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
9227 __perf_mux_hrtimer_init(cpuctx
, cpu
);
9231 if (!pmu
->start_txn
) {
9232 if (pmu
->pmu_enable
) {
9234 * If we have pmu_enable/pmu_disable calls, install
9235 * transaction stubs that use that to try and batch
9236 * hardware accesses.
9238 pmu
->start_txn
= perf_pmu_start_txn
;
9239 pmu
->commit_txn
= perf_pmu_commit_txn
;
9240 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
9242 pmu
->start_txn
= perf_pmu_nop_txn
;
9243 pmu
->commit_txn
= perf_pmu_nop_int
;
9244 pmu
->cancel_txn
= perf_pmu_nop_void
;
9248 if (!pmu
->pmu_enable
) {
9249 pmu
->pmu_enable
= perf_pmu_nop_void
;
9250 pmu
->pmu_disable
= perf_pmu_nop_void
;
9253 if (!pmu
->event_idx
)
9254 pmu
->event_idx
= perf_event_idx_default
;
9256 list_add_rcu(&pmu
->entry
, &pmus
);
9257 atomic_set(&pmu
->exclusive_cnt
, 0);
9260 mutex_unlock(&pmus_lock
);
9265 device_del(pmu
->dev
);
9266 put_device(pmu
->dev
);
9269 if (pmu
->type
>= PERF_TYPE_MAX
)
9270 idr_remove(&pmu_idr
, pmu
->type
);
9273 free_percpu(pmu
->pmu_disable_count
);
9276 EXPORT_SYMBOL_GPL(perf_pmu_register
);
9278 void perf_pmu_unregister(struct pmu
*pmu
)
9282 mutex_lock(&pmus_lock
);
9283 remove_device
= pmu_bus_running
;
9284 list_del_rcu(&pmu
->entry
);
9285 mutex_unlock(&pmus_lock
);
9288 * We dereference the pmu list under both SRCU and regular RCU, so
9289 * synchronize against both of those.
9291 synchronize_srcu(&pmus_srcu
);
9294 free_percpu(pmu
->pmu_disable_count
);
9295 if (pmu
->type
>= PERF_TYPE_MAX
)
9296 idr_remove(&pmu_idr
, pmu
->type
);
9297 if (remove_device
) {
9298 if (pmu
->nr_addr_filters
)
9299 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9300 device_del(pmu
->dev
);
9301 put_device(pmu
->dev
);
9303 free_pmu_context(pmu
);
9305 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9307 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9309 struct perf_event_context
*ctx
= NULL
;
9312 if (!try_module_get(pmu
->module
))
9315 if (event
->group_leader
!= event
) {
9317 * This ctx->mutex can nest when we're called through
9318 * inheritance. See the perf_event_ctx_lock_nested() comment.
9320 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9321 SINGLE_DEPTH_NESTING
);
9326 ret
= pmu
->event_init(event
);
9329 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9332 module_put(pmu
->module
);
9337 static struct pmu
*perf_init_event(struct perf_event
*event
)
9343 idx
= srcu_read_lock(&pmus_srcu
);
9345 /* Try parent's PMU first: */
9346 if (event
->parent
&& event
->parent
->pmu
) {
9347 pmu
= event
->parent
->pmu
;
9348 ret
= perf_try_init_event(pmu
, event
);
9354 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9357 ret
= perf_try_init_event(pmu
, event
);
9363 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9364 ret
= perf_try_init_event(pmu
, event
);
9368 if (ret
!= -ENOENT
) {
9373 pmu
= ERR_PTR(-ENOENT
);
9375 srcu_read_unlock(&pmus_srcu
, idx
);
9380 static void attach_sb_event(struct perf_event
*event
)
9382 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9384 raw_spin_lock(&pel
->lock
);
9385 list_add_rcu(&event
->sb_list
, &pel
->list
);
9386 raw_spin_unlock(&pel
->lock
);
9390 * We keep a list of all !task (and therefore per-cpu) events
9391 * that need to receive side-band records.
9393 * This avoids having to scan all the various PMU per-cpu contexts
9396 static void account_pmu_sb_event(struct perf_event
*event
)
9398 if (is_sb_event(event
))
9399 attach_sb_event(event
);
9402 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9407 if (is_cgroup_event(event
))
9408 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9411 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9412 static void account_freq_event_nohz(void)
9414 #ifdef CONFIG_NO_HZ_FULL
9415 /* Lock so we don't race with concurrent unaccount */
9416 spin_lock(&nr_freq_lock
);
9417 if (atomic_inc_return(&nr_freq_events
) == 1)
9418 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9419 spin_unlock(&nr_freq_lock
);
9423 static void account_freq_event(void)
9425 if (tick_nohz_full_enabled())
9426 account_freq_event_nohz();
9428 atomic_inc(&nr_freq_events
);
9432 static void account_event(struct perf_event
*event
)
9439 if (event
->attach_state
& PERF_ATTACH_TASK
)
9441 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9442 atomic_inc(&nr_mmap_events
);
9443 if (event
->attr
.comm
)
9444 atomic_inc(&nr_comm_events
);
9445 if (event
->attr
.namespaces
)
9446 atomic_inc(&nr_namespaces_events
);
9447 if (event
->attr
.task
)
9448 atomic_inc(&nr_task_events
);
9449 if (event
->attr
.freq
)
9450 account_freq_event();
9451 if (event
->attr
.context_switch
) {
9452 atomic_inc(&nr_switch_events
);
9455 if (has_branch_stack(event
))
9457 if (is_cgroup_event(event
))
9461 if (atomic_inc_not_zero(&perf_sched_count
))
9464 mutex_lock(&perf_sched_mutex
);
9465 if (!atomic_read(&perf_sched_count
)) {
9466 static_branch_enable(&perf_sched_events
);
9468 * Guarantee that all CPUs observe they key change and
9469 * call the perf scheduling hooks before proceeding to
9470 * install events that need them.
9472 synchronize_sched();
9475 * Now that we have waited for the sync_sched(), allow further
9476 * increments to by-pass the mutex.
9478 atomic_inc(&perf_sched_count
);
9479 mutex_unlock(&perf_sched_mutex
);
9483 account_event_cpu(event
, event
->cpu
);
9485 account_pmu_sb_event(event
);
9489 * Allocate and initialize a event structure
9491 static struct perf_event
*
9492 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9493 struct task_struct
*task
,
9494 struct perf_event
*group_leader
,
9495 struct perf_event
*parent_event
,
9496 perf_overflow_handler_t overflow_handler
,
9497 void *context
, int cgroup_fd
)
9500 struct perf_event
*event
;
9501 struct hw_perf_event
*hwc
;
9504 if ((unsigned)cpu
>= nr_cpu_ids
) {
9505 if (!task
|| cpu
!= -1)
9506 return ERR_PTR(-EINVAL
);
9509 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9511 return ERR_PTR(-ENOMEM
);
9514 * Single events are their own group leaders, with an
9515 * empty sibling list:
9518 group_leader
= event
;
9520 mutex_init(&event
->child_mutex
);
9521 INIT_LIST_HEAD(&event
->child_list
);
9523 INIT_LIST_HEAD(&event
->group_entry
);
9524 INIT_LIST_HEAD(&event
->event_entry
);
9525 INIT_LIST_HEAD(&event
->sibling_list
);
9526 INIT_LIST_HEAD(&event
->rb_entry
);
9527 INIT_LIST_HEAD(&event
->active_entry
);
9528 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9529 INIT_HLIST_NODE(&event
->hlist_entry
);
9532 init_waitqueue_head(&event
->waitq
);
9533 init_irq_work(&event
->pending
, perf_pending_event
);
9535 mutex_init(&event
->mmap_mutex
);
9536 raw_spin_lock_init(&event
->addr_filters
.lock
);
9538 atomic_long_set(&event
->refcount
, 1);
9540 event
->attr
= *attr
;
9541 event
->group_leader
= group_leader
;
9545 event
->parent
= parent_event
;
9547 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9548 event
->id
= atomic64_inc_return(&perf_event_id
);
9550 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9553 event
->attach_state
= PERF_ATTACH_TASK
;
9555 * XXX pmu::event_init needs to know what task to account to
9556 * and we cannot use the ctx information because we need the
9557 * pmu before we get a ctx.
9559 get_task_struct(task
);
9560 event
->hw
.target
= task
;
9563 event
->clock
= &local_clock
;
9565 event
->clock
= parent_event
->clock
;
9567 if (!overflow_handler
&& parent_event
) {
9568 overflow_handler
= parent_event
->overflow_handler
;
9569 context
= parent_event
->overflow_handler_context
;
9570 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9571 if (overflow_handler
== bpf_overflow_handler
) {
9572 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9575 err
= PTR_ERR(prog
);
9579 event
->orig_overflow_handler
=
9580 parent_event
->orig_overflow_handler
;
9585 if (overflow_handler
) {
9586 event
->overflow_handler
= overflow_handler
;
9587 event
->overflow_handler_context
= context
;
9588 } else if (is_write_backward(event
)){
9589 event
->overflow_handler
= perf_event_output_backward
;
9590 event
->overflow_handler_context
= NULL
;
9592 event
->overflow_handler
= perf_event_output_forward
;
9593 event
->overflow_handler_context
= NULL
;
9596 perf_event__state_init(event
);
9601 hwc
->sample_period
= attr
->sample_period
;
9602 if (attr
->freq
&& attr
->sample_freq
)
9603 hwc
->sample_period
= 1;
9604 hwc
->last_period
= hwc
->sample_period
;
9606 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9609 * We currently do not support PERF_SAMPLE_READ on inherited events.
9610 * See perf_output_read().
9612 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
9615 if (!has_branch_stack(event
))
9616 event
->attr
.branch_sample_type
= 0;
9618 if (cgroup_fd
!= -1) {
9619 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9624 pmu
= perf_init_event(event
);
9630 err
= exclusive_event_init(event
);
9634 if (has_addr_filter(event
)) {
9635 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9636 sizeof(unsigned long),
9638 if (!event
->addr_filters_offs
) {
9643 /* force hw sync on the address filters */
9644 event
->addr_filters_gen
= 1;
9647 if (!event
->parent
) {
9648 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9649 err
= get_callchain_buffers(attr
->sample_max_stack
);
9651 goto err_addr_filters
;
9655 /* symmetric to unaccount_event() in _free_event() */
9656 account_event(event
);
9661 kfree(event
->addr_filters_offs
);
9664 exclusive_event_destroy(event
);
9668 event
->destroy(event
);
9669 module_put(pmu
->module
);
9671 if (is_cgroup_event(event
))
9672 perf_detach_cgroup(event
);
9674 put_pid_ns(event
->ns
);
9675 if (event
->hw
.target
)
9676 put_task_struct(event
->hw
.target
);
9679 return ERR_PTR(err
);
9682 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9683 struct perf_event_attr
*attr
)
9688 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9692 * zero the full structure, so that a short copy will be nice.
9694 memset(attr
, 0, sizeof(*attr
));
9696 ret
= get_user(size
, &uattr
->size
);
9700 if (size
> PAGE_SIZE
) /* silly large */
9703 if (!size
) /* abi compat */
9704 size
= PERF_ATTR_SIZE_VER0
;
9706 if (size
< PERF_ATTR_SIZE_VER0
)
9710 * If we're handed a bigger struct than we know of,
9711 * ensure all the unknown bits are 0 - i.e. new
9712 * user-space does not rely on any kernel feature
9713 * extensions we dont know about yet.
9715 if (size
> sizeof(*attr
)) {
9716 unsigned char __user
*addr
;
9717 unsigned char __user
*end
;
9720 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9721 end
= (void __user
*)uattr
+ size
;
9723 for (; addr
< end
; addr
++) {
9724 ret
= get_user(val
, addr
);
9730 size
= sizeof(*attr
);
9733 ret
= copy_from_user(attr
, uattr
, size
);
9739 if (attr
->__reserved_1
)
9742 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9745 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9748 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9749 u64 mask
= attr
->branch_sample_type
;
9751 /* only using defined bits */
9752 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9755 /* at least one branch bit must be set */
9756 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9759 /* propagate priv level, when not set for branch */
9760 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9762 /* exclude_kernel checked on syscall entry */
9763 if (!attr
->exclude_kernel
)
9764 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9766 if (!attr
->exclude_user
)
9767 mask
|= PERF_SAMPLE_BRANCH_USER
;
9769 if (!attr
->exclude_hv
)
9770 mask
|= PERF_SAMPLE_BRANCH_HV
;
9772 * adjust user setting (for HW filter setup)
9774 attr
->branch_sample_type
= mask
;
9776 /* privileged levels capture (kernel, hv): check permissions */
9777 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9778 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9782 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9783 ret
= perf_reg_validate(attr
->sample_regs_user
);
9788 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9789 if (!arch_perf_have_user_stack_dump())
9793 * We have __u32 type for the size, but so far
9794 * we can only use __u16 as maximum due to the
9795 * __u16 sample size limit.
9797 if (attr
->sample_stack_user
>= USHRT_MAX
)
9799 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9803 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9804 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9809 put_user(sizeof(*attr
), &uattr
->size
);
9815 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9817 struct ring_buffer
*rb
= NULL
;
9823 /* don't allow circular references */
9824 if (event
== output_event
)
9828 * Don't allow cross-cpu buffers
9830 if (output_event
->cpu
!= event
->cpu
)
9834 * If its not a per-cpu rb, it must be the same task.
9836 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9840 * Mixing clocks in the same buffer is trouble you don't need.
9842 if (output_event
->clock
!= event
->clock
)
9846 * Either writing ring buffer from beginning or from end.
9847 * Mixing is not allowed.
9849 if (is_write_backward(output_event
) != is_write_backward(event
))
9853 * If both events generate aux data, they must be on the same PMU
9855 if (has_aux(event
) && has_aux(output_event
) &&
9856 event
->pmu
!= output_event
->pmu
)
9860 mutex_lock(&event
->mmap_mutex
);
9861 /* Can't redirect output if we've got an active mmap() */
9862 if (atomic_read(&event
->mmap_count
))
9866 /* get the rb we want to redirect to */
9867 rb
= ring_buffer_get(output_event
);
9872 ring_buffer_attach(event
, rb
);
9876 mutex_unlock(&event
->mmap_mutex
);
9882 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9888 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9891 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9893 bool nmi_safe
= false;
9896 case CLOCK_MONOTONIC
:
9897 event
->clock
= &ktime_get_mono_fast_ns
;
9901 case CLOCK_MONOTONIC_RAW
:
9902 event
->clock
= &ktime_get_raw_fast_ns
;
9906 case CLOCK_REALTIME
:
9907 event
->clock
= &ktime_get_real_ns
;
9910 case CLOCK_BOOTTIME
:
9911 event
->clock
= &ktime_get_boot_ns
;
9915 event
->clock
= &ktime_get_tai_ns
;
9922 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9929 * Variation on perf_event_ctx_lock_nested(), except we take two context
9932 static struct perf_event_context
*
9933 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9934 struct perf_event_context
*ctx
)
9936 struct perf_event_context
*gctx
;
9940 gctx
= READ_ONCE(group_leader
->ctx
);
9941 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9947 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9949 if (group_leader
->ctx
!= gctx
) {
9950 mutex_unlock(&ctx
->mutex
);
9951 mutex_unlock(&gctx
->mutex
);
9960 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9962 * @attr_uptr: event_id type attributes for monitoring/sampling
9965 * @group_fd: group leader event fd
9967 SYSCALL_DEFINE5(perf_event_open
,
9968 struct perf_event_attr __user
*, attr_uptr
,
9969 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9971 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9972 struct perf_event
*event
, *sibling
;
9973 struct perf_event_attr attr
;
9974 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9975 struct file
*event_file
= NULL
;
9976 struct fd group
= {NULL
, 0};
9977 struct task_struct
*task
= NULL
;
9982 int f_flags
= O_RDWR
;
9985 /* for future expandability... */
9986 if (flags
& ~PERF_FLAG_ALL
)
9989 if (perf_paranoid_any() && !capable(CAP_SYS_ADMIN
))
9992 err
= perf_copy_attr(attr_uptr
, &attr
);
9996 if (!attr
.exclude_kernel
) {
9997 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
10001 if (attr
.namespaces
) {
10002 if (!capable(CAP_SYS_ADMIN
))
10007 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
10010 if (attr
.sample_period
& (1ULL << 63))
10014 /* Only privileged users can get physical addresses */
10015 if ((attr
.sample_type
& PERF_SAMPLE_PHYS_ADDR
) &&
10016 perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
10019 if (!attr
.sample_max_stack
)
10020 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
10023 * In cgroup mode, the pid argument is used to pass the fd
10024 * opened to the cgroup directory in cgroupfs. The cpu argument
10025 * designates the cpu on which to monitor threads from that
10028 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
10031 if (flags
& PERF_FLAG_FD_CLOEXEC
)
10032 f_flags
|= O_CLOEXEC
;
10034 event_fd
= get_unused_fd_flags(f_flags
);
10038 if (group_fd
!= -1) {
10039 err
= perf_fget_light(group_fd
, &group
);
10042 group_leader
= group
.file
->private_data
;
10043 if (flags
& PERF_FLAG_FD_OUTPUT
)
10044 output_event
= group_leader
;
10045 if (flags
& PERF_FLAG_FD_NO_GROUP
)
10046 group_leader
= NULL
;
10049 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
10050 task
= find_lively_task_by_vpid(pid
);
10051 if (IS_ERR(task
)) {
10052 err
= PTR_ERR(task
);
10057 if (task
&& group_leader
&&
10058 group_leader
->attr
.inherit
!= attr
.inherit
) {
10064 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
10069 * Reuse ptrace permission checks for now.
10071 * We must hold cred_guard_mutex across this and any potential
10072 * perf_install_in_context() call for this new event to
10073 * serialize against exec() altering our credentials (and the
10074 * perf_event_exit_task() that could imply).
10077 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
10081 if (flags
& PERF_FLAG_PID_CGROUP
)
10084 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
10085 NULL
, NULL
, cgroup_fd
);
10086 if (IS_ERR(event
)) {
10087 err
= PTR_ERR(event
);
10091 if (is_sampling_event(event
)) {
10092 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
10099 * Special case software events and allow them to be part of
10100 * any hardware group.
10104 if (attr
.use_clockid
) {
10105 err
= perf_event_set_clock(event
, attr
.clockid
);
10110 if (pmu
->task_ctx_nr
== perf_sw_context
)
10111 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
10113 if (group_leader
&&
10114 (is_software_event(event
) != is_software_event(group_leader
))) {
10115 if (is_software_event(event
)) {
10117 * If event and group_leader are not both a software
10118 * event, and event is, then group leader is not.
10120 * Allow the addition of software events to !software
10121 * groups, this is safe because software events never
10122 * fail to schedule.
10124 pmu
= group_leader
->pmu
;
10125 } else if (is_software_event(group_leader
) &&
10126 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10128 * In case the group is a pure software group, and we
10129 * try to add a hardware event, move the whole group to
10130 * the hardware context.
10137 * Get the target context (task or percpu):
10139 ctx
= find_get_context(pmu
, task
, event
);
10141 err
= PTR_ERR(ctx
);
10145 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
10151 * Look up the group leader (we will attach this event to it):
10153 if (group_leader
) {
10157 * Do not allow a recursive hierarchy (this new sibling
10158 * becoming part of another group-sibling):
10160 if (group_leader
->group_leader
!= group_leader
)
10163 /* All events in a group should have the same clock */
10164 if (group_leader
->clock
!= event
->clock
)
10168 * Make sure we're both events for the same CPU;
10169 * grouping events for different CPUs is broken; since
10170 * you can never concurrently schedule them anyhow.
10172 if (group_leader
->cpu
!= event
->cpu
)
10176 * Make sure we're both on the same task, or both
10179 if (group_leader
->ctx
->task
!= ctx
->task
)
10183 * Do not allow to attach to a group in a different task
10184 * or CPU context. If we're moving SW events, we'll fix
10185 * this up later, so allow that.
10187 if (!move_group
&& group_leader
->ctx
!= ctx
)
10191 * Only a group leader can be exclusive or pinned
10193 if (attr
.exclusive
|| attr
.pinned
)
10197 if (output_event
) {
10198 err
= perf_event_set_output(event
, output_event
);
10203 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
10205 if (IS_ERR(event_file
)) {
10206 err
= PTR_ERR(event_file
);
10212 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
10214 if (gctx
->task
== TASK_TOMBSTONE
) {
10220 * Check if we raced against another sys_perf_event_open() call
10221 * moving the software group underneath us.
10223 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10225 * If someone moved the group out from under us, check
10226 * if this new event wound up on the same ctx, if so
10227 * its the regular !move_group case, otherwise fail.
10233 perf_event_ctx_unlock(group_leader
, gctx
);
10238 mutex_lock(&ctx
->mutex
);
10241 if (ctx
->task
== TASK_TOMBSTONE
) {
10246 if (!perf_event_validate_size(event
)) {
10253 * Check if the @cpu we're creating an event for is online.
10255 * We use the perf_cpu_context::ctx::mutex to serialize against
10256 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10258 struct perf_cpu_context
*cpuctx
=
10259 container_of(ctx
, struct perf_cpu_context
, ctx
);
10261 if (!cpuctx
->online
) {
10269 * Must be under the same ctx::mutex as perf_install_in_context(),
10270 * because we need to serialize with concurrent event creation.
10272 if (!exclusive_event_installable(event
, ctx
)) {
10273 /* exclusive and group stuff are assumed mutually exclusive */
10274 WARN_ON_ONCE(move_group
);
10280 WARN_ON_ONCE(ctx
->parent_ctx
);
10283 * This is the point on no return; we cannot fail hereafter. This is
10284 * where we start modifying current state.
10289 * See perf_event_ctx_lock() for comments on the details
10290 * of swizzling perf_event::ctx.
10292 perf_remove_from_context(group_leader
, 0);
10295 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10297 perf_remove_from_context(sibling
, 0);
10302 * Wait for everybody to stop referencing the events through
10303 * the old lists, before installing it on new lists.
10308 * Install the group siblings before the group leader.
10310 * Because a group leader will try and install the entire group
10311 * (through the sibling list, which is still in-tact), we can
10312 * end up with siblings installed in the wrong context.
10314 * By installing siblings first we NO-OP because they're not
10315 * reachable through the group lists.
10317 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10319 perf_event__state_init(sibling
);
10320 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
10325 * Removing from the context ends up with disabled
10326 * event. What we want here is event in the initial
10327 * startup state, ready to be add into new context.
10329 perf_event__state_init(group_leader
);
10330 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
10335 * Precalculate sample_data sizes; do while holding ctx::mutex such
10336 * that we're serialized against further additions and before
10337 * perf_install_in_context() which is the point the event is active and
10338 * can use these values.
10340 perf_event__header_size(event
);
10341 perf_event__id_header_size(event
);
10343 event
->owner
= current
;
10345 perf_install_in_context(ctx
, event
, event
->cpu
);
10346 perf_unpin_context(ctx
);
10349 perf_event_ctx_unlock(group_leader
, gctx
);
10350 mutex_unlock(&ctx
->mutex
);
10353 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10354 put_task_struct(task
);
10357 mutex_lock(¤t
->perf_event_mutex
);
10358 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10359 mutex_unlock(¤t
->perf_event_mutex
);
10362 * Drop the reference on the group_event after placing the
10363 * new event on the sibling_list. This ensures destruction
10364 * of the group leader will find the pointer to itself in
10365 * perf_group_detach().
10368 fd_install(event_fd
, event_file
);
10373 perf_event_ctx_unlock(group_leader
, gctx
);
10374 mutex_unlock(&ctx
->mutex
);
10378 perf_unpin_context(ctx
);
10382 * If event_file is set, the fput() above will have called ->release()
10383 * and that will take care of freeing the event.
10389 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10392 put_task_struct(task
);
10396 put_unused_fd(event_fd
);
10401 * perf_event_create_kernel_counter
10403 * @attr: attributes of the counter to create
10404 * @cpu: cpu in which the counter is bound
10405 * @task: task to profile (NULL for percpu)
10407 struct perf_event
*
10408 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10409 struct task_struct
*task
,
10410 perf_overflow_handler_t overflow_handler
,
10413 struct perf_event_context
*ctx
;
10414 struct perf_event
*event
;
10418 * Get the target context (task or percpu):
10421 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10422 overflow_handler
, context
, -1);
10423 if (IS_ERR(event
)) {
10424 err
= PTR_ERR(event
);
10428 /* Mark owner so we could distinguish it from user events. */
10429 event
->owner
= TASK_TOMBSTONE
;
10431 ctx
= find_get_context(event
->pmu
, task
, event
);
10433 err
= PTR_ERR(ctx
);
10437 WARN_ON_ONCE(ctx
->parent_ctx
);
10438 mutex_lock(&ctx
->mutex
);
10439 if (ctx
->task
== TASK_TOMBSTONE
) {
10446 * Check if the @cpu we're creating an event for is online.
10448 * We use the perf_cpu_context::ctx::mutex to serialize against
10449 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10451 struct perf_cpu_context
*cpuctx
=
10452 container_of(ctx
, struct perf_cpu_context
, ctx
);
10453 if (!cpuctx
->online
) {
10459 if (!exclusive_event_installable(event
, ctx
)) {
10464 perf_install_in_context(ctx
, event
, cpu
);
10465 perf_unpin_context(ctx
);
10466 mutex_unlock(&ctx
->mutex
);
10471 mutex_unlock(&ctx
->mutex
);
10472 perf_unpin_context(ctx
);
10477 return ERR_PTR(err
);
10479 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10481 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10483 struct perf_event_context
*src_ctx
;
10484 struct perf_event_context
*dst_ctx
;
10485 struct perf_event
*event
, *tmp
;
10488 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10489 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10492 * See perf_event_ctx_lock() for comments on the details
10493 * of swizzling perf_event::ctx.
10495 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10496 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10498 perf_remove_from_context(event
, 0);
10499 unaccount_event_cpu(event
, src_cpu
);
10501 list_add(&event
->migrate_entry
, &events
);
10505 * Wait for the events to quiesce before re-instating them.
10510 * Re-instate events in 2 passes.
10512 * Skip over group leaders and only install siblings on this first
10513 * pass, siblings will not get enabled without a leader, however a
10514 * leader will enable its siblings, even if those are still on the old
10517 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10518 if (event
->group_leader
== event
)
10521 list_del(&event
->migrate_entry
);
10522 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10523 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10524 account_event_cpu(event
, dst_cpu
);
10525 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10530 * Once all the siblings are setup properly, install the group leaders
10533 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10534 list_del(&event
->migrate_entry
);
10535 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10536 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10537 account_event_cpu(event
, dst_cpu
);
10538 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10541 mutex_unlock(&dst_ctx
->mutex
);
10542 mutex_unlock(&src_ctx
->mutex
);
10544 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10546 static void sync_child_event(struct perf_event
*child_event
,
10547 struct task_struct
*child
)
10549 struct perf_event
*parent_event
= child_event
->parent
;
10552 if (child_event
->attr
.inherit_stat
)
10553 perf_event_read_event(child_event
, child
);
10555 child_val
= perf_event_count(child_event
);
10558 * Add back the child's count to the parent's count:
10560 atomic64_add(child_val
, &parent_event
->child_count
);
10561 atomic64_add(child_event
->total_time_enabled
,
10562 &parent_event
->child_total_time_enabled
);
10563 atomic64_add(child_event
->total_time_running
,
10564 &parent_event
->child_total_time_running
);
10568 perf_event_exit_event(struct perf_event
*child_event
,
10569 struct perf_event_context
*child_ctx
,
10570 struct task_struct
*child
)
10572 struct perf_event
*parent_event
= child_event
->parent
;
10575 * Do not destroy the 'original' grouping; because of the context
10576 * switch optimization the original events could've ended up in a
10577 * random child task.
10579 * If we were to destroy the original group, all group related
10580 * operations would cease to function properly after this random
10583 * Do destroy all inherited groups, we don't care about those
10584 * and being thorough is better.
10586 raw_spin_lock_irq(&child_ctx
->lock
);
10587 WARN_ON_ONCE(child_ctx
->is_active
);
10590 perf_group_detach(child_event
);
10591 list_del_event(child_event
, child_ctx
);
10592 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
10593 raw_spin_unlock_irq(&child_ctx
->lock
);
10596 * Parent events are governed by their filedesc, retain them.
10598 if (!parent_event
) {
10599 perf_event_wakeup(child_event
);
10603 * Child events can be cleaned up.
10606 sync_child_event(child_event
, child
);
10609 * Remove this event from the parent's list
10611 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10612 mutex_lock(&parent_event
->child_mutex
);
10613 list_del_init(&child_event
->child_list
);
10614 mutex_unlock(&parent_event
->child_mutex
);
10617 * Kick perf_poll() for is_event_hup().
10619 perf_event_wakeup(parent_event
);
10620 free_event(child_event
);
10621 put_event(parent_event
);
10624 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10626 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10627 struct perf_event
*child_event
, *next
;
10629 WARN_ON_ONCE(child
!= current
);
10631 child_ctx
= perf_pin_task_context(child
, ctxn
);
10636 * In order to reduce the amount of tricky in ctx tear-down, we hold
10637 * ctx::mutex over the entire thing. This serializes against almost
10638 * everything that wants to access the ctx.
10640 * The exception is sys_perf_event_open() /
10641 * perf_event_create_kernel_count() which does find_get_context()
10642 * without ctx::mutex (it cannot because of the move_group double mutex
10643 * lock thing). See the comments in perf_install_in_context().
10645 mutex_lock(&child_ctx
->mutex
);
10648 * In a single ctx::lock section, de-schedule the events and detach the
10649 * context from the task such that we cannot ever get it scheduled back
10652 raw_spin_lock_irq(&child_ctx
->lock
);
10653 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
10656 * Now that the context is inactive, destroy the task <-> ctx relation
10657 * and mark the context dead.
10659 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10660 put_ctx(child_ctx
); /* cannot be last */
10661 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10662 put_task_struct(current
); /* cannot be last */
10664 clone_ctx
= unclone_ctx(child_ctx
);
10665 raw_spin_unlock_irq(&child_ctx
->lock
);
10668 put_ctx(clone_ctx
);
10671 * Report the task dead after unscheduling the events so that we
10672 * won't get any samples after PERF_RECORD_EXIT. We can however still
10673 * get a few PERF_RECORD_READ events.
10675 perf_event_task(child
, child_ctx
, 0);
10677 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10678 perf_event_exit_event(child_event
, child_ctx
, child
);
10680 mutex_unlock(&child_ctx
->mutex
);
10682 put_ctx(child_ctx
);
10686 * When a child task exits, feed back event values to parent events.
10688 * Can be called with cred_guard_mutex held when called from
10689 * install_exec_creds().
10691 void perf_event_exit_task(struct task_struct
*child
)
10693 struct perf_event
*event
, *tmp
;
10696 mutex_lock(&child
->perf_event_mutex
);
10697 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10699 list_del_init(&event
->owner_entry
);
10702 * Ensure the list deletion is visible before we clear
10703 * the owner, closes a race against perf_release() where
10704 * we need to serialize on the owner->perf_event_mutex.
10706 smp_store_release(&event
->owner
, NULL
);
10708 mutex_unlock(&child
->perf_event_mutex
);
10710 for_each_task_context_nr(ctxn
)
10711 perf_event_exit_task_context(child
, ctxn
);
10714 * The perf_event_exit_task_context calls perf_event_task
10715 * with child's task_ctx, which generates EXIT events for
10716 * child contexts and sets child->perf_event_ctxp[] to NULL.
10717 * At this point we need to send EXIT events to cpu contexts.
10719 perf_event_task(child
, NULL
, 0);
10722 static void perf_free_event(struct perf_event
*event
,
10723 struct perf_event_context
*ctx
)
10725 struct perf_event
*parent
= event
->parent
;
10727 if (WARN_ON_ONCE(!parent
))
10730 mutex_lock(&parent
->child_mutex
);
10731 list_del_init(&event
->child_list
);
10732 mutex_unlock(&parent
->child_mutex
);
10736 raw_spin_lock_irq(&ctx
->lock
);
10737 perf_group_detach(event
);
10738 list_del_event(event
, ctx
);
10739 raw_spin_unlock_irq(&ctx
->lock
);
10744 * Free an unexposed, unused context as created by inheritance by
10745 * perf_event_init_task below, used by fork() in case of fail.
10747 * Not all locks are strictly required, but take them anyway to be nice and
10748 * help out with the lockdep assertions.
10750 void perf_event_free_task(struct task_struct
*task
)
10752 struct perf_event_context
*ctx
;
10753 struct perf_event
*event
, *tmp
;
10756 for_each_task_context_nr(ctxn
) {
10757 ctx
= task
->perf_event_ctxp
[ctxn
];
10761 mutex_lock(&ctx
->mutex
);
10762 raw_spin_lock_irq(&ctx
->lock
);
10764 * Destroy the task <-> ctx relation and mark the context dead.
10766 * This is important because even though the task hasn't been
10767 * exposed yet the context has been (through child_list).
10769 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
10770 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
10771 put_task_struct(task
); /* cannot be last */
10772 raw_spin_unlock_irq(&ctx
->lock
);
10774 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
10775 perf_free_event(event
, ctx
);
10777 mutex_unlock(&ctx
->mutex
);
10782 void perf_event_delayed_put(struct task_struct
*task
)
10786 for_each_task_context_nr(ctxn
)
10787 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10790 struct file
*perf_event_get(unsigned int fd
)
10794 file
= fget_raw(fd
);
10796 return ERR_PTR(-EBADF
);
10798 if (file
->f_op
!= &perf_fops
) {
10800 return ERR_PTR(-EBADF
);
10806 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10809 return ERR_PTR(-EINVAL
);
10811 return &event
->attr
;
10815 * Inherit a event from parent task to child task.
10818 * - valid pointer on success
10819 * - NULL for orphaned events
10820 * - IS_ERR() on error
10822 static struct perf_event
*
10823 inherit_event(struct perf_event
*parent_event
,
10824 struct task_struct
*parent
,
10825 struct perf_event_context
*parent_ctx
,
10826 struct task_struct
*child
,
10827 struct perf_event
*group_leader
,
10828 struct perf_event_context
*child_ctx
)
10830 enum perf_event_active_state parent_state
= parent_event
->state
;
10831 struct perf_event
*child_event
;
10832 unsigned long flags
;
10835 * Instead of creating recursive hierarchies of events,
10836 * we link inherited events back to the original parent,
10837 * which has a filp for sure, which we use as the reference
10840 if (parent_event
->parent
)
10841 parent_event
= parent_event
->parent
;
10843 child_event
= perf_event_alloc(&parent_event
->attr
,
10846 group_leader
, parent_event
,
10848 if (IS_ERR(child_event
))
10849 return child_event
;
10852 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10853 * must be under the same lock in order to serialize against
10854 * perf_event_release_kernel(), such that either we must observe
10855 * is_orphaned_event() or they will observe us on the child_list.
10857 mutex_lock(&parent_event
->child_mutex
);
10858 if (is_orphaned_event(parent_event
) ||
10859 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10860 mutex_unlock(&parent_event
->child_mutex
);
10861 free_event(child_event
);
10865 get_ctx(child_ctx
);
10868 * Make the child state follow the state of the parent event,
10869 * not its attr.disabled bit. We hold the parent's mutex,
10870 * so we won't race with perf_event_{en, dis}able_family.
10872 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10873 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10875 child_event
->state
= PERF_EVENT_STATE_OFF
;
10877 if (parent_event
->attr
.freq
) {
10878 u64 sample_period
= parent_event
->hw
.sample_period
;
10879 struct hw_perf_event
*hwc
= &child_event
->hw
;
10881 hwc
->sample_period
= sample_period
;
10882 hwc
->last_period
= sample_period
;
10884 local64_set(&hwc
->period_left
, sample_period
);
10887 child_event
->ctx
= child_ctx
;
10888 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10889 child_event
->overflow_handler_context
10890 = parent_event
->overflow_handler_context
;
10893 * Precalculate sample_data sizes
10895 perf_event__header_size(child_event
);
10896 perf_event__id_header_size(child_event
);
10899 * Link it up in the child's context:
10901 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10902 add_event_to_ctx(child_event
, child_ctx
);
10903 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10906 * Link this into the parent event's child list
10908 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10909 mutex_unlock(&parent_event
->child_mutex
);
10911 return child_event
;
10915 * Inherits an event group.
10917 * This will quietly suppress orphaned events; !inherit_event() is not an error.
10918 * This matches with perf_event_release_kernel() removing all child events.
10924 static int inherit_group(struct perf_event
*parent_event
,
10925 struct task_struct
*parent
,
10926 struct perf_event_context
*parent_ctx
,
10927 struct task_struct
*child
,
10928 struct perf_event_context
*child_ctx
)
10930 struct perf_event
*leader
;
10931 struct perf_event
*sub
;
10932 struct perf_event
*child_ctr
;
10934 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10935 child
, NULL
, child_ctx
);
10936 if (IS_ERR(leader
))
10937 return PTR_ERR(leader
);
10939 * @leader can be NULL here because of is_orphaned_event(). In this
10940 * case inherit_event() will create individual events, similar to what
10941 * perf_group_detach() would do anyway.
10943 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10944 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10945 child
, leader
, child_ctx
);
10946 if (IS_ERR(child_ctr
))
10947 return PTR_ERR(child_ctr
);
10953 * Creates the child task context and tries to inherit the event-group.
10955 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
10956 * inherited_all set when we 'fail' to inherit an orphaned event; this is
10957 * consistent with perf_event_release_kernel() removing all child events.
10964 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10965 struct perf_event_context
*parent_ctx
,
10966 struct task_struct
*child
, int ctxn
,
10967 int *inherited_all
)
10970 struct perf_event_context
*child_ctx
;
10972 if (!event
->attr
.inherit
) {
10973 *inherited_all
= 0;
10977 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10980 * This is executed from the parent task context, so
10981 * inherit events that have been marked for cloning.
10982 * First allocate and initialize a context for the
10985 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10989 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10992 ret
= inherit_group(event
, parent
, parent_ctx
,
10996 *inherited_all
= 0;
11002 * Initialize the perf_event context in task_struct
11004 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
11006 struct perf_event_context
*child_ctx
, *parent_ctx
;
11007 struct perf_event_context
*cloned_ctx
;
11008 struct perf_event
*event
;
11009 struct task_struct
*parent
= current
;
11010 int inherited_all
= 1;
11011 unsigned long flags
;
11014 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
11018 * If the parent's context is a clone, pin it so it won't get
11019 * swapped under us.
11021 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
11026 * No need to check if parent_ctx != NULL here; since we saw
11027 * it non-NULL earlier, the only reason for it to become NULL
11028 * is if we exit, and since we're currently in the middle of
11029 * a fork we can't be exiting at the same time.
11033 * Lock the parent list. No need to lock the child - not PID
11034 * hashed yet and not running, so nobody can access it.
11036 mutex_lock(&parent_ctx
->mutex
);
11039 * We dont have to disable NMIs - we are only looking at
11040 * the list, not manipulating it:
11042 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
11043 ret
= inherit_task_group(event
, parent
, parent_ctx
,
11044 child
, ctxn
, &inherited_all
);
11050 * We can't hold ctx->lock when iterating the ->flexible_group list due
11051 * to allocations, but we need to prevent rotation because
11052 * rotate_ctx() will change the list from interrupt context.
11054 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
11055 parent_ctx
->rotate_disable
= 1;
11056 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
11058 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
11059 ret
= inherit_task_group(event
, parent
, parent_ctx
,
11060 child
, ctxn
, &inherited_all
);
11065 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
11066 parent_ctx
->rotate_disable
= 0;
11068 child_ctx
= child
->perf_event_ctxp
[ctxn
];
11070 if (child_ctx
&& inherited_all
) {
11072 * Mark the child context as a clone of the parent
11073 * context, or of whatever the parent is a clone of.
11075 * Note that if the parent is a clone, the holding of
11076 * parent_ctx->lock avoids it from being uncloned.
11078 cloned_ctx
= parent_ctx
->parent_ctx
;
11080 child_ctx
->parent_ctx
= cloned_ctx
;
11081 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
11083 child_ctx
->parent_ctx
= parent_ctx
;
11084 child_ctx
->parent_gen
= parent_ctx
->generation
;
11086 get_ctx(child_ctx
->parent_ctx
);
11089 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
11091 mutex_unlock(&parent_ctx
->mutex
);
11093 perf_unpin_context(parent_ctx
);
11094 put_ctx(parent_ctx
);
11100 * Initialize the perf_event context in task_struct
11102 int perf_event_init_task(struct task_struct
*child
)
11106 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
11107 mutex_init(&child
->perf_event_mutex
);
11108 INIT_LIST_HEAD(&child
->perf_event_list
);
11110 for_each_task_context_nr(ctxn
) {
11111 ret
= perf_event_init_context(child
, ctxn
);
11113 perf_event_free_task(child
);
11121 static void __init
perf_event_init_all_cpus(void)
11123 struct swevent_htable
*swhash
;
11126 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
11128 for_each_possible_cpu(cpu
) {
11129 swhash
= &per_cpu(swevent_htable
, cpu
);
11130 mutex_init(&swhash
->hlist_mutex
);
11131 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
11133 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
11134 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
11136 #ifdef CONFIG_CGROUP_PERF
11137 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
11139 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
11143 void perf_swevent_init_cpu(unsigned int cpu
)
11145 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
11147 mutex_lock(&swhash
->hlist_mutex
);
11148 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
11149 struct swevent_hlist
*hlist
;
11151 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
11153 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
11155 mutex_unlock(&swhash
->hlist_mutex
);
11158 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
11159 static void __perf_event_exit_context(void *__info
)
11161 struct perf_event_context
*ctx
= __info
;
11162 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
11163 struct perf_event
*event
;
11165 raw_spin_lock(&ctx
->lock
);
11166 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
11167 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
11168 raw_spin_unlock(&ctx
->lock
);
11171 static void perf_event_exit_cpu_context(int cpu
)
11173 struct perf_cpu_context
*cpuctx
;
11174 struct perf_event_context
*ctx
;
11177 mutex_lock(&pmus_lock
);
11178 list_for_each_entry(pmu
, &pmus
, entry
) {
11179 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11180 ctx
= &cpuctx
->ctx
;
11182 mutex_lock(&ctx
->mutex
);
11183 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
11184 cpuctx
->online
= 0;
11185 mutex_unlock(&ctx
->mutex
);
11187 cpumask_clear_cpu(cpu
, perf_online_mask
);
11188 mutex_unlock(&pmus_lock
);
11192 static void perf_event_exit_cpu_context(int cpu
) { }
11196 int perf_event_init_cpu(unsigned int cpu
)
11198 struct perf_cpu_context
*cpuctx
;
11199 struct perf_event_context
*ctx
;
11202 perf_swevent_init_cpu(cpu
);
11204 mutex_lock(&pmus_lock
);
11205 cpumask_set_cpu(cpu
, perf_online_mask
);
11206 list_for_each_entry(pmu
, &pmus
, entry
) {
11207 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11208 ctx
= &cpuctx
->ctx
;
11210 mutex_lock(&ctx
->mutex
);
11211 cpuctx
->online
= 1;
11212 mutex_unlock(&ctx
->mutex
);
11214 mutex_unlock(&pmus_lock
);
11219 int perf_event_exit_cpu(unsigned int cpu
)
11221 perf_event_exit_cpu_context(cpu
);
11226 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
11230 for_each_online_cpu(cpu
)
11231 perf_event_exit_cpu(cpu
);
11237 * Run the perf reboot notifier at the very last possible moment so that
11238 * the generic watchdog code runs as long as possible.
11240 static struct notifier_block perf_reboot_notifier
= {
11241 .notifier_call
= perf_reboot
,
11242 .priority
= INT_MIN
,
11245 void __init
perf_event_init(void)
11249 idr_init(&pmu_idr
);
11251 perf_event_init_all_cpus();
11252 init_srcu_struct(&pmus_srcu
);
11253 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
11254 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
11255 perf_pmu_register(&perf_task_clock
, NULL
, -1);
11256 perf_tp_register();
11257 perf_event_init_cpu(smp_processor_id());
11258 register_reboot_notifier(&perf_reboot_notifier
);
11260 ret
= init_hw_breakpoint();
11261 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
11264 * Build time assertion that we keep the data_head at the intended
11265 * location. IOW, validation we got the __reserved[] size right.
11267 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
11271 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
11274 struct perf_pmu_events_attr
*pmu_attr
=
11275 container_of(attr
, struct perf_pmu_events_attr
, attr
);
11277 if (pmu_attr
->event_str
)
11278 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
11282 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
11284 static int __init
perf_event_sysfs_init(void)
11289 mutex_lock(&pmus_lock
);
11291 ret
= bus_register(&pmu_bus
);
11295 list_for_each_entry(pmu
, &pmus
, entry
) {
11296 if (!pmu
->name
|| pmu
->type
< 0)
11299 ret
= pmu_dev_alloc(pmu
);
11300 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
11302 pmu_bus_running
= 1;
11306 mutex_unlock(&pmus_lock
);
11310 device_initcall(perf_event_sysfs_init
);
11312 #ifdef CONFIG_CGROUP_PERF
11313 static struct cgroup_subsys_state
*
11314 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
11316 struct perf_cgroup
*jc
;
11318 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
11320 return ERR_PTR(-ENOMEM
);
11322 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
11325 return ERR_PTR(-ENOMEM
);
11331 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
11333 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
11335 free_percpu(jc
->info
);
11339 static int __perf_cgroup_move(void *info
)
11341 struct task_struct
*task
= info
;
11343 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
11348 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
11350 struct task_struct
*task
;
11351 struct cgroup_subsys_state
*css
;
11353 cgroup_taskset_for_each(task
, css
, tset
)
11354 task_function_call(task
, __perf_cgroup_move
, task
);
11357 struct cgroup_subsys perf_event_cgrp_subsys
= {
11358 .css_alloc
= perf_cgroup_css_alloc
,
11359 .css_free
= perf_cgroup_css_free
,
11360 .attach
= perf_cgroup_attach
,
11362 * Implicitly enable on dfl hierarchy so that perf events can
11363 * always be filtered by cgroup2 path as long as perf_event
11364 * controller is not mounted on a legacy hierarchy.
11366 .implicit_on_dfl
= true,
11369 #endif /* CONFIG_CGROUP_PERF */