2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
52 #include <asm/irq_regs.h>
54 typedef int (*remote_function_f
)(void *);
56 struct remote_function_call
{
57 struct task_struct
*p
;
58 remote_function_f func
;
63 static void remote_function(void *data
)
65 struct remote_function_call
*tfc
= data
;
66 struct task_struct
*p
= tfc
->p
;
70 if (task_cpu(p
) != smp_processor_id())
74 * Now that we're on right CPU with IRQs disabled, we can test
75 * if we hit the right task without races.
78 tfc
->ret
= -ESRCH
; /* No such (running) process */
83 tfc
->ret
= tfc
->func(tfc
->info
);
87 * task_function_call - call a function on the cpu on which a task runs
88 * @p: the task to evaluate
89 * @func: the function to be called
90 * @info: the function call argument
92 * Calls the function @func when the task is currently running. This might
93 * be on the current CPU, which just calls the function directly
95 * returns: @func return value, or
96 * -ESRCH - when the process isn't running
97 * -EAGAIN - when the process moved away
100 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
102 struct remote_function_call data
= {
111 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
114 } while (ret
== -EAGAIN
);
120 * cpu_function_call - call a function on the cpu
121 * @func: the function to be called
122 * @info: the function call argument
124 * Calls the function @func on the remote cpu.
126 * returns: @func return value or -ENXIO when the cpu is offline
128 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
130 struct remote_function_call data
= {
134 .ret
= -ENXIO
, /* No such CPU */
137 smp_call_function_single(cpu
, remote_function
, &data
, 1);
142 static inline struct perf_cpu_context
*
143 __get_cpu_context(struct perf_event_context
*ctx
)
145 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
148 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
149 struct perf_event_context
*ctx
)
151 raw_spin_lock(&cpuctx
->ctx
.lock
);
153 raw_spin_lock(&ctx
->lock
);
156 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
157 struct perf_event_context
*ctx
)
160 raw_spin_unlock(&ctx
->lock
);
161 raw_spin_unlock(&cpuctx
->ctx
.lock
);
164 #define TASK_TOMBSTONE ((void *)-1L)
166 static bool is_kernel_event(struct perf_event
*event
)
168 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
172 * On task ctx scheduling...
174 * When !ctx->nr_events a task context will not be scheduled. This means
175 * we can disable the scheduler hooks (for performance) without leaving
176 * pending task ctx state.
178 * This however results in two special cases:
180 * - removing the last event from a task ctx; this is relatively straight
181 * forward and is done in __perf_remove_from_context.
183 * - adding the first event to a task ctx; this is tricky because we cannot
184 * rely on ctx->is_active and therefore cannot use event_function_call().
185 * See perf_install_in_context().
187 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
190 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
191 struct perf_event_context
*, void *);
193 struct event_function_struct
{
194 struct perf_event
*event
;
199 static int event_function(void *info
)
201 struct event_function_struct
*efs
= info
;
202 struct perf_event
*event
= efs
->event
;
203 struct perf_event_context
*ctx
= event
->ctx
;
204 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
205 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
208 WARN_ON_ONCE(!irqs_disabled());
210 perf_ctx_lock(cpuctx
, task_ctx
);
212 * Since we do the IPI call without holding ctx->lock things can have
213 * changed, double check we hit the task we set out to hit.
216 if (ctx
->task
!= current
) {
222 * We only use event_function_call() on established contexts,
223 * and event_function() is only ever called when active (or
224 * rather, we'll have bailed in task_function_call() or the
225 * above ctx->task != current test), therefore we must have
226 * ctx->is_active here.
228 WARN_ON_ONCE(!ctx
->is_active
);
230 * And since we have ctx->is_active, cpuctx->task_ctx must
233 WARN_ON_ONCE(task_ctx
!= ctx
);
235 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
238 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
240 perf_ctx_unlock(cpuctx
, task_ctx
);
245 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
247 struct perf_event_context
*ctx
= event
->ctx
;
248 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
249 struct event_function_struct efs
= {
255 if (!event
->parent
) {
257 * If this is a !child event, we must hold ctx::mutex to
258 * stabilize the the event->ctx relation. See
259 * perf_event_ctx_lock().
261 lockdep_assert_held(&ctx
->mutex
);
265 cpu_function_call(event
->cpu
, event_function
, &efs
);
269 if (task
== TASK_TOMBSTONE
)
273 if (!task_function_call(task
, event_function
, &efs
))
276 raw_spin_lock_irq(&ctx
->lock
);
278 * Reload the task pointer, it might have been changed by
279 * a concurrent perf_event_context_sched_out().
282 if (task
== TASK_TOMBSTONE
) {
283 raw_spin_unlock_irq(&ctx
->lock
);
286 if (ctx
->is_active
) {
287 raw_spin_unlock_irq(&ctx
->lock
);
290 func(event
, NULL
, ctx
, data
);
291 raw_spin_unlock_irq(&ctx
->lock
);
295 * Similar to event_function_call() + event_function(), but hard assumes IRQs
296 * are already disabled and we're on the right CPU.
298 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
300 struct perf_event_context
*ctx
= event
->ctx
;
301 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
302 struct task_struct
*task
= READ_ONCE(ctx
->task
);
303 struct perf_event_context
*task_ctx
= NULL
;
305 WARN_ON_ONCE(!irqs_disabled());
308 if (task
== TASK_TOMBSTONE
)
314 perf_ctx_lock(cpuctx
, task_ctx
);
317 if (task
== TASK_TOMBSTONE
)
322 * We must be either inactive or active and the right task,
323 * otherwise we're screwed, since we cannot IPI to somewhere
326 if (ctx
->is_active
) {
327 if (WARN_ON_ONCE(task
!= current
))
330 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
334 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
337 func(event
, cpuctx
, ctx
, data
);
339 perf_ctx_unlock(cpuctx
, task_ctx
);
342 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
343 PERF_FLAG_FD_OUTPUT |\
344 PERF_FLAG_PID_CGROUP |\
345 PERF_FLAG_FD_CLOEXEC)
348 * branch priv levels that need permission checks
350 #define PERF_SAMPLE_BRANCH_PERM_PLM \
351 (PERF_SAMPLE_BRANCH_KERNEL |\
352 PERF_SAMPLE_BRANCH_HV)
355 EVENT_FLEXIBLE
= 0x1,
358 /* see ctx_resched() for details */
360 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
364 * perf_sched_events : >0 events exist
365 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
368 static void perf_sched_delayed(struct work_struct
*work
);
369 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
370 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
371 static DEFINE_MUTEX(perf_sched_mutex
);
372 static atomic_t perf_sched_count
;
374 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
375 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
376 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
378 static atomic_t nr_mmap_events __read_mostly
;
379 static atomic_t nr_comm_events __read_mostly
;
380 static atomic_t nr_task_events __read_mostly
;
381 static atomic_t nr_freq_events __read_mostly
;
382 static atomic_t nr_switch_events __read_mostly
;
384 static LIST_HEAD(pmus
);
385 static DEFINE_MUTEX(pmus_lock
);
386 static struct srcu_struct pmus_srcu
;
389 * perf event paranoia level:
390 * -1 - not paranoid at all
391 * 0 - disallow raw tracepoint access for unpriv
392 * 1 - disallow cpu events for unpriv
393 * 2 - disallow kernel profiling for unpriv
395 int sysctl_perf_event_paranoid __read_mostly
= 2;
397 /* Minimum for 512 kiB + 1 user control page */
398 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
401 * max perf event sample rate
403 #define DEFAULT_MAX_SAMPLE_RATE 100000
404 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
405 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
407 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
409 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
410 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
412 static int perf_sample_allowed_ns __read_mostly
=
413 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
415 static void update_perf_cpu_limits(void)
417 u64 tmp
= perf_sample_period_ns
;
419 tmp
*= sysctl_perf_cpu_time_max_percent
;
420 tmp
= div_u64(tmp
, 100);
424 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
427 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
429 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
430 void __user
*buffer
, size_t *lenp
,
433 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
439 * If throttling is disabled don't allow the write:
441 if (sysctl_perf_cpu_time_max_percent
== 100 ||
442 sysctl_perf_cpu_time_max_percent
== 0)
445 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
446 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
447 update_perf_cpu_limits();
452 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
454 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
455 void __user
*buffer
, size_t *lenp
,
458 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
463 if (sysctl_perf_cpu_time_max_percent
== 100 ||
464 sysctl_perf_cpu_time_max_percent
== 0) {
466 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
467 WRITE_ONCE(perf_sample_allowed_ns
, 0);
469 update_perf_cpu_limits();
476 * perf samples are done in some very critical code paths (NMIs).
477 * If they take too much CPU time, the system can lock up and not
478 * get any real work done. This will drop the sample rate when
479 * we detect that events are taking too long.
481 #define NR_ACCUMULATED_SAMPLES 128
482 static DEFINE_PER_CPU(u64
, running_sample_length
);
484 static u64 __report_avg
;
485 static u64 __report_allowed
;
487 static void perf_duration_warn(struct irq_work
*w
)
489 printk_ratelimited(KERN_INFO
490 "perf: interrupt took too long (%lld > %lld), lowering "
491 "kernel.perf_event_max_sample_rate to %d\n",
492 __report_avg
, __report_allowed
,
493 sysctl_perf_event_sample_rate
);
496 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
498 void perf_sample_event_took(u64 sample_len_ns
)
500 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
508 /* Decay the counter by 1 average sample. */
509 running_len
= __this_cpu_read(running_sample_length
);
510 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
511 running_len
+= sample_len_ns
;
512 __this_cpu_write(running_sample_length
, running_len
);
515 * Note: this will be biased artifically low until we have
516 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
517 * from having to maintain a count.
519 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
520 if (avg_len
<= max_len
)
523 __report_avg
= avg_len
;
524 __report_allowed
= max_len
;
527 * Compute a throttle threshold 25% below the current duration.
529 avg_len
+= avg_len
/ 4;
530 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
536 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
537 WRITE_ONCE(max_samples_per_tick
, max
);
539 sysctl_perf_event_sample_rate
= max
* HZ
;
540 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
542 if (!irq_work_queue(&perf_duration_work
)) {
543 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
544 "kernel.perf_event_max_sample_rate to %d\n",
545 __report_avg
, __report_allowed
,
546 sysctl_perf_event_sample_rate
);
550 static atomic64_t perf_event_id
;
552 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
553 enum event_type_t event_type
);
555 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
556 enum event_type_t event_type
,
557 struct task_struct
*task
);
559 static void update_context_time(struct perf_event_context
*ctx
);
560 static u64
perf_event_time(struct perf_event
*event
);
562 void __weak
perf_event_print_debug(void) { }
564 extern __weak
const char *perf_pmu_name(void)
569 static inline u64
perf_clock(void)
571 return local_clock();
574 static inline u64
perf_event_clock(struct perf_event
*event
)
576 return event
->clock();
579 #ifdef CONFIG_CGROUP_PERF
582 perf_cgroup_match(struct perf_event
*event
)
584 struct perf_event_context
*ctx
= event
->ctx
;
585 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
587 /* @event doesn't care about cgroup */
591 /* wants specific cgroup scope but @cpuctx isn't associated with any */
596 * Cgroup scoping is recursive. An event enabled for a cgroup is
597 * also enabled for all its descendant cgroups. If @cpuctx's
598 * cgroup is a descendant of @event's (the test covers identity
599 * case), it's a match.
601 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
602 event
->cgrp
->css
.cgroup
);
605 static inline void perf_detach_cgroup(struct perf_event
*event
)
607 css_put(&event
->cgrp
->css
);
611 static inline int is_cgroup_event(struct perf_event
*event
)
613 return event
->cgrp
!= NULL
;
616 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
618 struct perf_cgroup_info
*t
;
620 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
624 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
626 struct perf_cgroup_info
*info
;
631 info
= this_cpu_ptr(cgrp
->info
);
633 info
->time
+= now
- info
->timestamp
;
634 info
->timestamp
= now
;
637 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
639 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
641 __update_cgrp_time(cgrp_out
);
644 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
646 struct perf_cgroup
*cgrp
;
649 * ensure we access cgroup data only when needed and
650 * when we know the cgroup is pinned (css_get)
652 if (!is_cgroup_event(event
))
655 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
657 * Do not update time when cgroup is not active
659 if (cgrp
== event
->cgrp
)
660 __update_cgrp_time(event
->cgrp
);
664 perf_cgroup_set_timestamp(struct task_struct
*task
,
665 struct perf_event_context
*ctx
)
667 struct perf_cgroup
*cgrp
;
668 struct perf_cgroup_info
*info
;
671 * ctx->lock held by caller
672 * ensure we do not access cgroup data
673 * unless we have the cgroup pinned (css_get)
675 if (!task
|| !ctx
->nr_cgroups
)
678 cgrp
= perf_cgroup_from_task(task
, ctx
);
679 info
= this_cpu_ptr(cgrp
->info
);
680 info
->timestamp
= ctx
->timestamp
;
683 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
685 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
686 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
689 * reschedule events based on the cgroup constraint of task.
691 * mode SWOUT : schedule out everything
692 * mode SWIN : schedule in based on cgroup for next
694 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
696 struct perf_cpu_context
*cpuctx
;
697 struct list_head
*list
;
701 * Disable interrupts and preemption to avoid this CPU's
702 * cgrp_cpuctx_entry to change under us.
704 local_irq_save(flags
);
706 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
707 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
708 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
710 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
711 perf_pmu_disable(cpuctx
->ctx
.pmu
);
713 if (mode
& PERF_CGROUP_SWOUT
) {
714 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
716 * must not be done before ctxswout due
717 * to event_filter_match() in event_sched_out()
722 if (mode
& PERF_CGROUP_SWIN
) {
723 WARN_ON_ONCE(cpuctx
->cgrp
);
725 * set cgrp before ctxsw in to allow
726 * event_filter_match() to not have to pass
728 * we pass the cpuctx->ctx to perf_cgroup_from_task()
729 * because cgorup events are only per-cpu
731 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
733 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
735 perf_pmu_enable(cpuctx
->ctx
.pmu
);
736 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
739 local_irq_restore(flags
);
742 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
743 struct task_struct
*next
)
745 struct perf_cgroup
*cgrp1
;
746 struct perf_cgroup
*cgrp2
= NULL
;
750 * we come here when we know perf_cgroup_events > 0
751 * we do not need to pass the ctx here because we know
752 * we are holding the rcu lock
754 cgrp1
= perf_cgroup_from_task(task
, NULL
);
755 cgrp2
= perf_cgroup_from_task(next
, NULL
);
758 * only schedule out current cgroup events if we know
759 * that we are switching to a different cgroup. Otherwise,
760 * do no touch the cgroup events.
763 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
768 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
769 struct task_struct
*task
)
771 struct perf_cgroup
*cgrp1
;
772 struct perf_cgroup
*cgrp2
= NULL
;
776 * we come here when we know perf_cgroup_events > 0
777 * we do not need to pass the ctx here because we know
778 * we are holding the rcu lock
780 cgrp1
= perf_cgroup_from_task(task
, NULL
);
781 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
784 * only need to schedule in cgroup events if we are changing
785 * cgroup during ctxsw. Cgroup events were not scheduled
786 * out of ctxsw out if that was not the case.
789 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
794 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
795 struct perf_event_attr
*attr
,
796 struct perf_event
*group_leader
)
798 struct perf_cgroup
*cgrp
;
799 struct cgroup_subsys_state
*css
;
800 struct fd f
= fdget(fd
);
806 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
807 &perf_event_cgrp_subsys
);
813 cgrp
= container_of(css
, struct perf_cgroup
, css
);
817 * all events in a group must monitor
818 * the same cgroup because a task belongs
819 * to only one perf cgroup at a time
821 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
822 perf_detach_cgroup(event
);
831 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
833 struct perf_cgroup_info
*t
;
834 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
835 event
->shadow_ctx_time
= now
- t
->timestamp
;
839 perf_cgroup_defer_enabled(struct perf_event
*event
)
842 * when the current task's perf cgroup does not match
843 * the event's, we need to remember to call the
844 * perf_mark_enable() function the first time a task with
845 * a matching perf cgroup is scheduled in.
847 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
848 event
->cgrp_defer_enabled
= 1;
852 perf_cgroup_mark_enabled(struct perf_event
*event
,
853 struct perf_event_context
*ctx
)
855 struct perf_event
*sub
;
856 u64 tstamp
= perf_event_time(event
);
858 if (!event
->cgrp_defer_enabled
)
861 event
->cgrp_defer_enabled
= 0;
863 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
864 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
865 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
866 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
867 sub
->cgrp_defer_enabled
= 0;
873 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
874 * cleared when last cgroup event is removed.
877 list_update_cgroup_event(struct perf_event
*event
,
878 struct perf_event_context
*ctx
, bool add
)
880 struct perf_cpu_context
*cpuctx
;
881 struct list_head
*cpuctx_entry
;
883 if (!is_cgroup_event(event
))
886 if (add
&& ctx
->nr_cgroups
++)
888 else if (!add
&& --ctx
->nr_cgroups
)
891 * Because cgroup events are always per-cpu events,
892 * this will always be called from the right CPU.
894 cpuctx
= __get_cpu_context(ctx
);
895 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
896 /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/
898 list_add(cpuctx_entry
, this_cpu_ptr(&cgrp_cpuctx_list
));
899 if (perf_cgroup_from_task(current
, ctx
) == event
->cgrp
)
900 cpuctx
->cgrp
= event
->cgrp
;
902 list_del(cpuctx_entry
);
907 #else /* !CONFIG_CGROUP_PERF */
910 perf_cgroup_match(struct perf_event
*event
)
915 static inline void perf_detach_cgroup(struct perf_event
*event
)
918 static inline int is_cgroup_event(struct perf_event
*event
)
923 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
928 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
932 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
936 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
937 struct task_struct
*next
)
941 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
942 struct task_struct
*task
)
946 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
947 struct perf_event_attr
*attr
,
948 struct perf_event
*group_leader
)
954 perf_cgroup_set_timestamp(struct task_struct
*task
,
955 struct perf_event_context
*ctx
)
960 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
965 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
969 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
975 perf_cgroup_defer_enabled(struct perf_event
*event
)
980 perf_cgroup_mark_enabled(struct perf_event
*event
,
981 struct perf_event_context
*ctx
)
986 list_update_cgroup_event(struct perf_event
*event
,
987 struct perf_event_context
*ctx
, bool add
)
994 * set default to be dependent on timer tick just
997 #define PERF_CPU_HRTIMER (1000 / HZ)
999 * function must be called with interrupts disbled
1001 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1003 struct perf_cpu_context
*cpuctx
;
1006 WARN_ON(!irqs_disabled());
1008 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1009 rotations
= perf_rotate_context(cpuctx
);
1011 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1013 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1015 cpuctx
->hrtimer_active
= 0;
1016 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1018 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1021 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1023 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1024 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1027 /* no multiplexing needed for SW PMU */
1028 if (pmu
->task_ctx_nr
== perf_sw_context
)
1032 * check default is sane, if not set then force to
1033 * default interval (1/tick)
1035 interval
= pmu
->hrtimer_interval_ms
;
1037 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1039 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1041 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1042 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1043 timer
->function
= perf_mux_hrtimer_handler
;
1046 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1048 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1049 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1050 unsigned long flags
;
1052 /* not for SW PMU */
1053 if (pmu
->task_ctx_nr
== perf_sw_context
)
1056 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1057 if (!cpuctx
->hrtimer_active
) {
1058 cpuctx
->hrtimer_active
= 1;
1059 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1060 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1062 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1067 void perf_pmu_disable(struct pmu
*pmu
)
1069 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1071 pmu
->pmu_disable(pmu
);
1074 void perf_pmu_enable(struct pmu
*pmu
)
1076 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1078 pmu
->pmu_enable(pmu
);
1081 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1084 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1085 * perf_event_task_tick() are fully serialized because they're strictly cpu
1086 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1087 * disabled, while perf_event_task_tick is called from IRQ context.
1089 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1091 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1093 WARN_ON(!irqs_disabled());
1095 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1097 list_add(&ctx
->active_ctx_list
, head
);
1100 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1102 WARN_ON(!irqs_disabled());
1104 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1106 list_del_init(&ctx
->active_ctx_list
);
1109 static void get_ctx(struct perf_event_context
*ctx
)
1111 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1114 static void free_ctx(struct rcu_head
*head
)
1116 struct perf_event_context
*ctx
;
1118 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1119 kfree(ctx
->task_ctx_data
);
1123 static void put_ctx(struct perf_event_context
*ctx
)
1125 if (atomic_dec_and_test(&ctx
->refcount
)) {
1126 if (ctx
->parent_ctx
)
1127 put_ctx(ctx
->parent_ctx
);
1128 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1129 put_task_struct(ctx
->task
);
1130 call_rcu(&ctx
->rcu_head
, free_ctx
);
1135 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1136 * perf_pmu_migrate_context() we need some magic.
1138 * Those places that change perf_event::ctx will hold both
1139 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1141 * Lock ordering is by mutex address. There are two other sites where
1142 * perf_event_context::mutex nests and those are:
1144 * - perf_event_exit_task_context() [ child , 0 ]
1145 * perf_event_exit_event()
1146 * put_event() [ parent, 1 ]
1148 * - perf_event_init_context() [ parent, 0 ]
1149 * inherit_task_group()
1152 * perf_event_alloc()
1154 * perf_try_init_event() [ child , 1 ]
1156 * While it appears there is an obvious deadlock here -- the parent and child
1157 * nesting levels are inverted between the two. This is in fact safe because
1158 * life-time rules separate them. That is an exiting task cannot fork, and a
1159 * spawning task cannot (yet) exit.
1161 * But remember that that these are parent<->child context relations, and
1162 * migration does not affect children, therefore these two orderings should not
1165 * The change in perf_event::ctx does not affect children (as claimed above)
1166 * because the sys_perf_event_open() case will install a new event and break
1167 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1168 * concerned with cpuctx and that doesn't have children.
1170 * The places that change perf_event::ctx will issue:
1172 * perf_remove_from_context();
1173 * synchronize_rcu();
1174 * perf_install_in_context();
1176 * to affect the change. The remove_from_context() + synchronize_rcu() should
1177 * quiesce the event, after which we can install it in the new location. This
1178 * means that only external vectors (perf_fops, prctl) can perturb the event
1179 * while in transit. Therefore all such accessors should also acquire
1180 * perf_event_context::mutex to serialize against this.
1182 * However; because event->ctx can change while we're waiting to acquire
1183 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1188 * task_struct::perf_event_mutex
1189 * perf_event_context::mutex
1190 * perf_event::child_mutex;
1191 * perf_event_context::lock
1192 * perf_event::mmap_mutex
1195 static struct perf_event_context
*
1196 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1198 struct perf_event_context
*ctx
;
1202 ctx
= ACCESS_ONCE(event
->ctx
);
1203 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1209 mutex_lock_nested(&ctx
->mutex
, nesting
);
1210 if (event
->ctx
!= ctx
) {
1211 mutex_unlock(&ctx
->mutex
);
1219 static inline struct perf_event_context
*
1220 perf_event_ctx_lock(struct perf_event
*event
)
1222 return perf_event_ctx_lock_nested(event
, 0);
1225 static void perf_event_ctx_unlock(struct perf_event
*event
,
1226 struct perf_event_context
*ctx
)
1228 mutex_unlock(&ctx
->mutex
);
1233 * This must be done under the ctx->lock, such as to serialize against
1234 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1235 * calling scheduler related locks and ctx->lock nests inside those.
1237 static __must_check
struct perf_event_context
*
1238 unclone_ctx(struct perf_event_context
*ctx
)
1240 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1242 lockdep_assert_held(&ctx
->lock
);
1245 ctx
->parent_ctx
= NULL
;
1251 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1254 * only top level events have the pid namespace they were created in
1257 event
= event
->parent
;
1259 return task_tgid_nr_ns(p
, event
->ns
);
1262 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1265 * only top level events have the pid namespace they were created in
1268 event
= event
->parent
;
1270 return task_pid_nr_ns(p
, event
->ns
);
1274 * If we inherit events we want to return the parent event id
1277 static u64
primary_event_id(struct perf_event
*event
)
1282 id
= event
->parent
->id
;
1288 * Get the perf_event_context for a task and lock it.
1290 * This has to cope with with the fact that until it is locked,
1291 * the context could get moved to another task.
1293 static struct perf_event_context
*
1294 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1296 struct perf_event_context
*ctx
;
1300 * One of the few rules of preemptible RCU is that one cannot do
1301 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1302 * part of the read side critical section was irqs-enabled -- see
1303 * rcu_read_unlock_special().
1305 * Since ctx->lock nests under rq->lock we must ensure the entire read
1306 * side critical section has interrupts disabled.
1308 local_irq_save(*flags
);
1310 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1313 * If this context is a clone of another, it might
1314 * get swapped for another underneath us by
1315 * perf_event_task_sched_out, though the
1316 * rcu_read_lock() protects us from any context
1317 * getting freed. Lock the context and check if it
1318 * got swapped before we could get the lock, and retry
1319 * if so. If we locked the right context, then it
1320 * can't get swapped on us any more.
1322 raw_spin_lock(&ctx
->lock
);
1323 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1324 raw_spin_unlock(&ctx
->lock
);
1326 local_irq_restore(*flags
);
1330 if (ctx
->task
== TASK_TOMBSTONE
||
1331 !atomic_inc_not_zero(&ctx
->refcount
)) {
1332 raw_spin_unlock(&ctx
->lock
);
1335 WARN_ON_ONCE(ctx
->task
!= task
);
1340 local_irq_restore(*flags
);
1345 * Get the context for a task and increment its pin_count so it
1346 * can't get swapped to another task. This also increments its
1347 * reference count so that the context can't get freed.
1349 static struct perf_event_context
*
1350 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1352 struct perf_event_context
*ctx
;
1353 unsigned long flags
;
1355 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1358 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1363 static void perf_unpin_context(struct perf_event_context
*ctx
)
1365 unsigned long flags
;
1367 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1369 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1373 * Update the record of the current time in a context.
1375 static void update_context_time(struct perf_event_context
*ctx
)
1377 u64 now
= perf_clock();
1379 ctx
->time
+= now
- ctx
->timestamp
;
1380 ctx
->timestamp
= now
;
1383 static u64
perf_event_time(struct perf_event
*event
)
1385 struct perf_event_context
*ctx
= event
->ctx
;
1387 if (is_cgroup_event(event
))
1388 return perf_cgroup_event_time(event
);
1390 return ctx
? ctx
->time
: 0;
1394 * Update the total_time_enabled and total_time_running fields for a event.
1396 static void update_event_times(struct perf_event
*event
)
1398 struct perf_event_context
*ctx
= event
->ctx
;
1401 lockdep_assert_held(&ctx
->lock
);
1403 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1404 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1408 * in cgroup mode, time_enabled represents
1409 * the time the event was enabled AND active
1410 * tasks were in the monitored cgroup. This is
1411 * independent of the activity of the context as
1412 * there may be a mix of cgroup and non-cgroup events.
1414 * That is why we treat cgroup events differently
1417 if (is_cgroup_event(event
))
1418 run_end
= perf_cgroup_event_time(event
);
1419 else if (ctx
->is_active
)
1420 run_end
= ctx
->time
;
1422 run_end
= event
->tstamp_stopped
;
1424 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1426 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1427 run_end
= event
->tstamp_stopped
;
1429 run_end
= perf_event_time(event
);
1431 event
->total_time_running
= run_end
- event
->tstamp_running
;
1436 * Update total_time_enabled and total_time_running for all events in a group.
1438 static void update_group_times(struct perf_event
*leader
)
1440 struct perf_event
*event
;
1442 update_event_times(leader
);
1443 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1444 update_event_times(event
);
1447 static enum event_type_t
get_event_type(struct perf_event
*event
)
1449 struct perf_event_context
*ctx
= event
->ctx
;
1450 enum event_type_t event_type
;
1452 lockdep_assert_held(&ctx
->lock
);
1454 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1456 event_type
|= EVENT_CPU
;
1461 static struct list_head
*
1462 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1464 if (event
->attr
.pinned
)
1465 return &ctx
->pinned_groups
;
1467 return &ctx
->flexible_groups
;
1471 * Add a event from the lists for its context.
1472 * Must be called with ctx->mutex and ctx->lock held.
1475 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1477 lockdep_assert_held(&ctx
->lock
);
1479 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1480 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1483 * If we're a stand alone event or group leader, we go to the context
1484 * list, group events are kept attached to the group so that
1485 * perf_group_detach can, at all times, locate all siblings.
1487 if (event
->group_leader
== event
) {
1488 struct list_head
*list
;
1490 event
->group_caps
= event
->event_caps
;
1492 list
= ctx_group_list(event
, ctx
);
1493 list_add_tail(&event
->group_entry
, list
);
1496 list_update_cgroup_event(event
, ctx
, true);
1498 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1500 if (event
->attr
.inherit_stat
)
1507 * Initialize event state based on the perf_event_attr::disabled.
1509 static inline void perf_event__state_init(struct perf_event
*event
)
1511 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1512 PERF_EVENT_STATE_INACTIVE
;
1515 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1517 int entry
= sizeof(u64
); /* value */
1521 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1522 size
+= sizeof(u64
);
1524 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1525 size
+= sizeof(u64
);
1527 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1528 entry
+= sizeof(u64
);
1530 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1532 size
+= sizeof(u64
);
1536 event
->read_size
= size
;
1539 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1541 struct perf_sample_data
*data
;
1544 if (sample_type
& PERF_SAMPLE_IP
)
1545 size
+= sizeof(data
->ip
);
1547 if (sample_type
& PERF_SAMPLE_ADDR
)
1548 size
+= sizeof(data
->addr
);
1550 if (sample_type
& PERF_SAMPLE_PERIOD
)
1551 size
+= sizeof(data
->period
);
1553 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1554 size
+= sizeof(data
->weight
);
1556 if (sample_type
& PERF_SAMPLE_READ
)
1557 size
+= event
->read_size
;
1559 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1560 size
+= sizeof(data
->data_src
.val
);
1562 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1563 size
+= sizeof(data
->txn
);
1565 event
->header_size
= size
;
1569 * Called at perf_event creation and when events are attached/detached from a
1572 static void perf_event__header_size(struct perf_event
*event
)
1574 __perf_event_read_size(event
,
1575 event
->group_leader
->nr_siblings
);
1576 __perf_event_header_size(event
, event
->attr
.sample_type
);
1579 static void perf_event__id_header_size(struct perf_event
*event
)
1581 struct perf_sample_data
*data
;
1582 u64 sample_type
= event
->attr
.sample_type
;
1585 if (sample_type
& PERF_SAMPLE_TID
)
1586 size
+= sizeof(data
->tid_entry
);
1588 if (sample_type
& PERF_SAMPLE_TIME
)
1589 size
+= sizeof(data
->time
);
1591 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1592 size
+= sizeof(data
->id
);
1594 if (sample_type
& PERF_SAMPLE_ID
)
1595 size
+= sizeof(data
->id
);
1597 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1598 size
+= sizeof(data
->stream_id
);
1600 if (sample_type
& PERF_SAMPLE_CPU
)
1601 size
+= sizeof(data
->cpu_entry
);
1603 event
->id_header_size
= size
;
1606 static bool perf_event_validate_size(struct perf_event
*event
)
1609 * The values computed here will be over-written when we actually
1612 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1613 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1614 perf_event__id_header_size(event
);
1617 * Sum the lot; should not exceed the 64k limit we have on records.
1618 * Conservative limit to allow for callchains and other variable fields.
1620 if (event
->read_size
+ event
->header_size
+
1621 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1627 static void perf_group_attach(struct perf_event
*event
)
1629 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1631 lockdep_assert_held(&event
->ctx
->lock
);
1634 * We can have double attach due to group movement in perf_event_open.
1636 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1639 event
->attach_state
|= PERF_ATTACH_GROUP
;
1641 if (group_leader
== event
)
1644 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1646 group_leader
->group_caps
&= event
->event_caps
;
1648 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1649 group_leader
->nr_siblings
++;
1651 perf_event__header_size(group_leader
);
1653 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1654 perf_event__header_size(pos
);
1658 * Remove a event from the lists for its context.
1659 * Must be called with ctx->mutex and ctx->lock held.
1662 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1664 WARN_ON_ONCE(event
->ctx
!= ctx
);
1665 lockdep_assert_held(&ctx
->lock
);
1668 * We can have double detach due to exit/hot-unplug + close.
1670 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1673 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1675 list_update_cgroup_event(event
, ctx
, false);
1678 if (event
->attr
.inherit_stat
)
1681 list_del_rcu(&event
->event_entry
);
1683 if (event
->group_leader
== event
)
1684 list_del_init(&event
->group_entry
);
1686 update_group_times(event
);
1689 * If event was in error state, then keep it
1690 * that way, otherwise bogus counts will be
1691 * returned on read(). The only way to get out
1692 * of error state is by explicit re-enabling
1695 if (event
->state
> PERF_EVENT_STATE_OFF
)
1696 event
->state
= PERF_EVENT_STATE_OFF
;
1701 static void perf_group_detach(struct perf_event
*event
)
1703 struct perf_event
*sibling
, *tmp
;
1704 struct list_head
*list
= NULL
;
1706 lockdep_assert_held(&event
->ctx
->lock
);
1709 * We can have double detach due to exit/hot-unplug + close.
1711 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1714 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1717 * If this is a sibling, remove it from its group.
1719 if (event
->group_leader
!= event
) {
1720 list_del_init(&event
->group_entry
);
1721 event
->group_leader
->nr_siblings
--;
1725 if (!list_empty(&event
->group_entry
))
1726 list
= &event
->group_entry
;
1729 * If this was a group event with sibling events then
1730 * upgrade the siblings to singleton events by adding them
1731 * to whatever list we are on.
1733 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1735 list_move_tail(&sibling
->group_entry
, list
);
1736 sibling
->group_leader
= sibling
;
1738 /* Inherit group flags from the previous leader */
1739 sibling
->group_caps
= event
->group_caps
;
1741 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1745 perf_event__header_size(event
->group_leader
);
1747 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1748 perf_event__header_size(tmp
);
1751 static bool is_orphaned_event(struct perf_event
*event
)
1753 return event
->state
== PERF_EVENT_STATE_DEAD
;
1756 static inline int __pmu_filter_match(struct perf_event
*event
)
1758 struct pmu
*pmu
= event
->pmu
;
1759 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1763 * Check whether we should attempt to schedule an event group based on
1764 * PMU-specific filtering. An event group can consist of HW and SW events,
1765 * potentially with a SW leader, so we must check all the filters, to
1766 * determine whether a group is schedulable:
1768 static inline int pmu_filter_match(struct perf_event
*event
)
1770 struct perf_event
*child
;
1772 if (!__pmu_filter_match(event
))
1775 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1776 if (!__pmu_filter_match(child
))
1784 event_filter_match(struct perf_event
*event
)
1786 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1787 perf_cgroup_match(event
) && pmu_filter_match(event
);
1791 event_sched_out(struct perf_event
*event
,
1792 struct perf_cpu_context
*cpuctx
,
1793 struct perf_event_context
*ctx
)
1795 u64 tstamp
= perf_event_time(event
);
1798 WARN_ON_ONCE(event
->ctx
!= ctx
);
1799 lockdep_assert_held(&ctx
->lock
);
1802 * An event which could not be activated because of
1803 * filter mismatch still needs to have its timings
1804 * maintained, otherwise bogus information is return
1805 * via read() for time_enabled, time_running:
1807 if (event
->state
== PERF_EVENT_STATE_INACTIVE
&&
1808 !event_filter_match(event
)) {
1809 delta
= tstamp
- event
->tstamp_stopped
;
1810 event
->tstamp_running
+= delta
;
1811 event
->tstamp_stopped
= tstamp
;
1814 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1817 perf_pmu_disable(event
->pmu
);
1819 event
->tstamp_stopped
= tstamp
;
1820 event
->pmu
->del(event
, 0);
1822 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1823 if (event
->pending_disable
) {
1824 event
->pending_disable
= 0;
1825 event
->state
= PERF_EVENT_STATE_OFF
;
1828 if (!is_software_event(event
))
1829 cpuctx
->active_oncpu
--;
1830 if (!--ctx
->nr_active
)
1831 perf_event_ctx_deactivate(ctx
);
1832 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1834 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1835 cpuctx
->exclusive
= 0;
1837 perf_pmu_enable(event
->pmu
);
1841 group_sched_out(struct perf_event
*group_event
,
1842 struct perf_cpu_context
*cpuctx
,
1843 struct perf_event_context
*ctx
)
1845 struct perf_event
*event
;
1846 int state
= group_event
->state
;
1848 perf_pmu_disable(ctx
->pmu
);
1850 event_sched_out(group_event
, cpuctx
, ctx
);
1853 * Schedule out siblings (if any):
1855 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1856 event_sched_out(event
, cpuctx
, ctx
);
1858 perf_pmu_enable(ctx
->pmu
);
1860 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1861 cpuctx
->exclusive
= 0;
1864 #define DETACH_GROUP 0x01UL
1867 * Cross CPU call to remove a performance event
1869 * We disable the event on the hardware level first. After that we
1870 * remove it from the context list.
1873 __perf_remove_from_context(struct perf_event
*event
,
1874 struct perf_cpu_context
*cpuctx
,
1875 struct perf_event_context
*ctx
,
1878 unsigned long flags
= (unsigned long)info
;
1880 event_sched_out(event
, cpuctx
, ctx
);
1881 if (flags
& DETACH_GROUP
)
1882 perf_group_detach(event
);
1883 list_del_event(event
, ctx
);
1885 if (!ctx
->nr_events
&& ctx
->is_active
) {
1888 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1889 cpuctx
->task_ctx
= NULL
;
1895 * Remove the event from a task's (or a CPU's) list of events.
1897 * If event->ctx is a cloned context, callers must make sure that
1898 * every task struct that event->ctx->task could possibly point to
1899 * remains valid. This is OK when called from perf_release since
1900 * that only calls us on the top-level context, which can't be a clone.
1901 * When called from perf_event_exit_task, it's OK because the
1902 * context has been detached from its task.
1904 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1906 struct perf_event_context
*ctx
= event
->ctx
;
1908 lockdep_assert_held(&ctx
->mutex
);
1910 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1913 * The above event_function_call() can NO-OP when it hits
1914 * TASK_TOMBSTONE. In that case we must already have been detached
1915 * from the context (by perf_event_exit_event()) but the grouping
1916 * might still be in-tact.
1918 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1919 if ((flags
& DETACH_GROUP
) &&
1920 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
1922 * Since in that case we cannot possibly be scheduled, simply
1925 raw_spin_lock_irq(&ctx
->lock
);
1926 perf_group_detach(event
);
1927 raw_spin_unlock_irq(&ctx
->lock
);
1932 * Cross CPU call to disable a performance event
1934 static void __perf_event_disable(struct perf_event
*event
,
1935 struct perf_cpu_context
*cpuctx
,
1936 struct perf_event_context
*ctx
,
1939 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1942 update_context_time(ctx
);
1943 update_cgrp_time_from_event(event
);
1944 update_group_times(event
);
1945 if (event
== event
->group_leader
)
1946 group_sched_out(event
, cpuctx
, ctx
);
1948 event_sched_out(event
, cpuctx
, ctx
);
1949 event
->state
= PERF_EVENT_STATE_OFF
;
1955 * If event->ctx is a cloned context, callers must make sure that
1956 * every task struct that event->ctx->task could possibly point to
1957 * remains valid. This condition is satisifed when called through
1958 * perf_event_for_each_child or perf_event_for_each because they
1959 * hold the top-level event's child_mutex, so any descendant that
1960 * goes to exit will block in perf_event_exit_event().
1962 * When called from perf_pending_event it's OK because event->ctx
1963 * is the current context on this CPU and preemption is disabled,
1964 * hence we can't get into perf_event_task_sched_out for this context.
1966 static void _perf_event_disable(struct perf_event
*event
)
1968 struct perf_event_context
*ctx
= event
->ctx
;
1970 raw_spin_lock_irq(&ctx
->lock
);
1971 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1972 raw_spin_unlock_irq(&ctx
->lock
);
1975 raw_spin_unlock_irq(&ctx
->lock
);
1977 event_function_call(event
, __perf_event_disable
, NULL
);
1980 void perf_event_disable_local(struct perf_event
*event
)
1982 event_function_local(event
, __perf_event_disable
, NULL
);
1986 * Strictly speaking kernel users cannot create groups and therefore this
1987 * interface does not need the perf_event_ctx_lock() magic.
1989 void perf_event_disable(struct perf_event
*event
)
1991 struct perf_event_context
*ctx
;
1993 ctx
= perf_event_ctx_lock(event
);
1994 _perf_event_disable(event
);
1995 perf_event_ctx_unlock(event
, ctx
);
1997 EXPORT_SYMBOL_GPL(perf_event_disable
);
1999 void perf_event_disable_inatomic(struct perf_event
*event
)
2001 event
->pending_disable
= 1;
2002 irq_work_queue(&event
->pending
);
2005 static void perf_set_shadow_time(struct perf_event
*event
,
2006 struct perf_event_context
*ctx
,
2010 * use the correct time source for the time snapshot
2012 * We could get by without this by leveraging the
2013 * fact that to get to this function, the caller
2014 * has most likely already called update_context_time()
2015 * and update_cgrp_time_xx() and thus both timestamp
2016 * are identical (or very close). Given that tstamp is,
2017 * already adjusted for cgroup, we could say that:
2018 * tstamp - ctx->timestamp
2020 * tstamp - cgrp->timestamp.
2022 * Then, in perf_output_read(), the calculation would
2023 * work with no changes because:
2024 * - event is guaranteed scheduled in
2025 * - no scheduled out in between
2026 * - thus the timestamp would be the same
2028 * But this is a bit hairy.
2030 * So instead, we have an explicit cgroup call to remain
2031 * within the time time source all along. We believe it
2032 * is cleaner and simpler to understand.
2034 if (is_cgroup_event(event
))
2035 perf_cgroup_set_shadow_time(event
, tstamp
);
2037 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
2040 #define MAX_INTERRUPTS (~0ULL)
2042 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2043 static void perf_log_itrace_start(struct perf_event
*event
);
2046 event_sched_in(struct perf_event
*event
,
2047 struct perf_cpu_context
*cpuctx
,
2048 struct perf_event_context
*ctx
)
2050 u64 tstamp
= perf_event_time(event
);
2053 lockdep_assert_held(&ctx
->lock
);
2055 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2058 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2060 * Order event::oncpu write to happen before the ACTIVE state
2064 WRITE_ONCE(event
->state
, PERF_EVENT_STATE_ACTIVE
);
2067 * Unthrottle events, since we scheduled we might have missed several
2068 * ticks already, also for a heavily scheduling task there is little
2069 * guarantee it'll get a tick in a timely manner.
2071 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2072 perf_log_throttle(event
, 1);
2073 event
->hw
.interrupts
= 0;
2077 * The new state must be visible before we turn it on in the hardware:
2081 perf_pmu_disable(event
->pmu
);
2083 perf_set_shadow_time(event
, ctx
, tstamp
);
2085 perf_log_itrace_start(event
);
2087 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2088 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2094 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
2096 if (!is_software_event(event
))
2097 cpuctx
->active_oncpu
++;
2098 if (!ctx
->nr_active
++)
2099 perf_event_ctx_activate(ctx
);
2100 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2103 if (event
->attr
.exclusive
)
2104 cpuctx
->exclusive
= 1;
2107 perf_pmu_enable(event
->pmu
);
2113 group_sched_in(struct perf_event
*group_event
,
2114 struct perf_cpu_context
*cpuctx
,
2115 struct perf_event_context
*ctx
)
2117 struct perf_event
*event
, *partial_group
= NULL
;
2118 struct pmu
*pmu
= ctx
->pmu
;
2119 u64 now
= ctx
->time
;
2120 bool simulate
= false;
2122 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2125 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2127 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2128 pmu
->cancel_txn(pmu
);
2129 perf_mux_hrtimer_restart(cpuctx
);
2134 * Schedule in siblings as one group (if any):
2136 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2137 if (event_sched_in(event
, cpuctx
, ctx
)) {
2138 partial_group
= event
;
2143 if (!pmu
->commit_txn(pmu
))
2148 * Groups can be scheduled in as one unit only, so undo any
2149 * partial group before returning:
2150 * The events up to the failed event are scheduled out normally,
2151 * tstamp_stopped will be updated.
2153 * The failed events and the remaining siblings need to have
2154 * their timings updated as if they had gone thru event_sched_in()
2155 * and event_sched_out(). This is required to get consistent timings
2156 * across the group. This also takes care of the case where the group
2157 * could never be scheduled by ensuring tstamp_stopped is set to mark
2158 * the time the event was actually stopped, such that time delta
2159 * calculation in update_event_times() is correct.
2161 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2162 if (event
== partial_group
)
2166 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2167 event
->tstamp_stopped
= now
;
2169 event_sched_out(event
, cpuctx
, ctx
);
2172 event_sched_out(group_event
, cpuctx
, ctx
);
2174 pmu
->cancel_txn(pmu
);
2176 perf_mux_hrtimer_restart(cpuctx
);
2182 * Work out whether we can put this event group on the CPU now.
2184 static int group_can_go_on(struct perf_event
*event
,
2185 struct perf_cpu_context
*cpuctx
,
2189 * Groups consisting entirely of software events can always go on.
2191 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2194 * If an exclusive group is already on, no other hardware
2197 if (cpuctx
->exclusive
)
2200 * If this group is exclusive and there are already
2201 * events on the CPU, it can't go on.
2203 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2206 * Otherwise, try to add it if all previous groups were able
2212 static void add_event_to_ctx(struct perf_event
*event
,
2213 struct perf_event_context
*ctx
)
2215 u64 tstamp
= perf_event_time(event
);
2217 list_add_event(event
, ctx
);
2218 perf_group_attach(event
);
2219 event
->tstamp_enabled
= tstamp
;
2220 event
->tstamp_running
= tstamp
;
2221 event
->tstamp_stopped
= tstamp
;
2224 static void ctx_sched_out(struct perf_event_context
*ctx
,
2225 struct perf_cpu_context
*cpuctx
,
2226 enum event_type_t event_type
);
2228 ctx_sched_in(struct perf_event_context
*ctx
,
2229 struct perf_cpu_context
*cpuctx
,
2230 enum event_type_t event_type
,
2231 struct task_struct
*task
);
2233 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2234 struct perf_event_context
*ctx
,
2235 enum event_type_t event_type
)
2237 if (!cpuctx
->task_ctx
)
2240 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2243 ctx_sched_out(ctx
, cpuctx
, event_type
);
2246 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2247 struct perf_event_context
*ctx
,
2248 struct task_struct
*task
)
2250 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2252 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2253 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2255 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2259 * We want to maintain the following priority of scheduling:
2260 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2261 * - task pinned (EVENT_PINNED)
2262 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2263 * - task flexible (EVENT_FLEXIBLE).
2265 * In order to avoid unscheduling and scheduling back in everything every
2266 * time an event is added, only do it for the groups of equal priority and
2269 * This can be called after a batch operation on task events, in which case
2270 * event_type is a bit mask of the types of events involved. For CPU events,
2271 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2273 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2274 struct perf_event_context
*task_ctx
,
2275 enum event_type_t event_type
)
2277 enum event_type_t ctx_event_type
= event_type
& EVENT_ALL
;
2278 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2281 * If pinned groups are involved, flexible groups also need to be
2284 if (event_type
& EVENT_PINNED
)
2285 event_type
|= EVENT_FLEXIBLE
;
2287 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2289 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2292 * Decide which cpu ctx groups to schedule out based on the types
2293 * of events that caused rescheduling:
2294 * - EVENT_CPU: schedule out corresponding groups;
2295 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2296 * - otherwise, do nothing more.
2299 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2300 else if (ctx_event_type
& EVENT_PINNED
)
2301 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2303 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2304 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2308 * Cross CPU call to install and enable a performance event
2310 * Very similar to remote_function() + event_function() but cannot assume that
2311 * things like ctx->is_active and cpuctx->task_ctx are set.
2313 static int __perf_install_in_context(void *info
)
2315 struct perf_event
*event
= info
;
2316 struct perf_event_context
*ctx
= event
->ctx
;
2317 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2318 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2319 bool reprogram
= true;
2322 raw_spin_lock(&cpuctx
->ctx
.lock
);
2324 raw_spin_lock(&ctx
->lock
);
2327 reprogram
= (ctx
->task
== current
);
2330 * If the task is running, it must be running on this CPU,
2331 * otherwise we cannot reprogram things.
2333 * If its not running, we don't care, ctx->lock will
2334 * serialize against it becoming runnable.
2336 if (task_curr(ctx
->task
) && !reprogram
) {
2341 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2342 } else if (task_ctx
) {
2343 raw_spin_lock(&task_ctx
->lock
);
2347 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2348 add_event_to_ctx(event
, ctx
);
2349 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2351 add_event_to_ctx(event
, ctx
);
2355 perf_ctx_unlock(cpuctx
, task_ctx
);
2361 * Attach a performance event to a context.
2363 * Very similar to event_function_call, see comment there.
2366 perf_install_in_context(struct perf_event_context
*ctx
,
2367 struct perf_event
*event
,
2370 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2372 lockdep_assert_held(&ctx
->mutex
);
2374 if (event
->cpu
!= -1)
2378 * Ensures that if we can observe event->ctx, both the event and ctx
2379 * will be 'complete'. See perf_iterate_sb_cpu().
2381 smp_store_release(&event
->ctx
, ctx
);
2384 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2389 * Should not happen, we validate the ctx is still alive before calling.
2391 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2395 * Installing events is tricky because we cannot rely on ctx->is_active
2396 * to be set in case this is the nr_events 0 -> 1 transition.
2398 * Instead we use task_curr(), which tells us if the task is running.
2399 * However, since we use task_curr() outside of rq::lock, we can race
2400 * against the actual state. This means the result can be wrong.
2402 * If we get a false positive, we retry, this is harmless.
2404 * If we get a false negative, things are complicated. If we are after
2405 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2406 * value must be correct. If we're before, it doesn't matter since
2407 * perf_event_context_sched_in() will program the counter.
2409 * However, this hinges on the remote context switch having observed
2410 * our task->perf_event_ctxp[] store, such that it will in fact take
2411 * ctx::lock in perf_event_context_sched_in().
2413 * We do this by task_function_call(), if the IPI fails to hit the task
2414 * we know any future context switch of task must see the
2415 * perf_event_ctpx[] store.
2419 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2420 * task_cpu() load, such that if the IPI then does not find the task
2421 * running, a future context switch of that task must observe the
2426 if (!task_function_call(task
, __perf_install_in_context
, event
))
2429 raw_spin_lock_irq(&ctx
->lock
);
2431 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2433 * Cannot happen because we already checked above (which also
2434 * cannot happen), and we hold ctx->mutex, which serializes us
2435 * against perf_event_exit_task_context().
2437 raw_spin_unlock_irq(&ctx
->lock
);
2441 * If the task is not running, ctx->lock will avoid it becoming so,
2442 * thus we can safely install the event.
2444 if (task_curr(task
)) {
2445 raw_spin_unlock_irq(&ctx
->lock
);
2448 add_event_to_ctx(event
, ctx
);
2449 raw_spin_unlock_irq(&ctx
->lock
);
2453 * Put a event into inactive state and update time fields.
2454 * Enabling the leader of a group effectively enables all
2455 * the group members that aren't explicitly disabled, so we
2456 * have to update their ->tstamp_enabled also.
2457 * Note: this works for group members as well as group leaders
2458 * since the non-leader members' sibling_lists will be empty.
2460 static void __perf_event_mark_enabled(struct perf_event
*event
)
2462 struct perf_event
*sub
;
2463 u64 tstamp
= perf_event_time(event
);
2465 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2466 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2467 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2468 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2469 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2474 * Cross CPU call to enable a performance event
2476 static void __perf_event_enable(struct perf_event
*event
,
2477 struct perf_cpu_context
*cpuctx
,
2478 struct perf_event_context
*ctx
,
2481 struct perf_event
*leader
= event
->group_leader
;
2482 struct perf_event_context
*task_ctx
;
2484 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2485 event
->state
<= PERF_EVENT_STATE_ERROR
)
2489 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2491 __perf_event_mark_enabled(event
);
2493 if (!ctx
->is_active
)
2496 if (!event_filter_match(event
)) {
2497 if (is_cgroup_event(event
))
2498 perf_cgroup_defer_enabled(event
);
2499 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2504 * If the event is in a group and isn't the group leader,
2505 * then don't put it on unless the group is on.
2507 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2508 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2512 task_ctx
= cpuctx
->task_ctx
;
2514 WARN_ON_ONCE(task_ctx
!= ctx
);
2516 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2522 * If event->ctx is a cloned context, callers must make sure that
2523 * every task struct that event->ctx->task could possibly point to
2524 * remains valid. This condition is satisfied when called through
2525 * perf_event_for_each_child or perf_event_for_each as described
2526 * for perf_event_disable.
2528 static void _perf_event_enable(struct perf_event
*event
)
2530 struct perf_event_context
*ctx
= event
->ctx
;
2532 raw_spin_lock_irq(&ctx
->lock
);
2533 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2534 event
->state
< PERF_EVENT_STATE_ERROR
) {
2535 raw_spin_unlock_irq(&ctx
->lock
);
2540 * If the event is in error state, clear that first.
2542 * That way, if we see the event in error state below, we know that it
2543 * has gone back into error state, as distinct from the task having
2544 * been scheduled away before the cross-call arrived.
2546 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2547 event
->state
= PERF_EVENT_STATE_OFF
;
2548 raw_spin_unlock_irq(&ctx
->lock
);
2550 event_function_call(event
, __perf_event_enable
, NULL
);
2554 * See perf_event_disable();
2556 void perf_event_enable(struct perf_event
*event
)
2558 struct perf_event_context
*ctx
;
2560 ctx
= perf_event_ctx_lock(event
);
2561 _perf_event_enable(event
);
2562 perf_event_ctx_unlock(event
, ctx
);
2564 EXPORT_SYMBOL_GPL(perf_event_enable
);
2566 struct stop_event_data
{
2567 struct perf_event
*event
;
2568 unsigned int restart
;
2571 static int __perf_event_stop(void *info
)
2573 struct stop_event_data
*sd
= info
;
2574 struct perf_event
*event
= sd
->event
;
2576 /* if it's already INACTIVE, do nothing */
2577 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2580 /* matches smp_wmb() in event_sched_in() */
2584 * There is a window with interrupts enabled before we get here,
2585 * so we need to check again lest we try to stop another CPU's event.
2587 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2590 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2593 * May race with the actual stop (through perf_pmu_output_stop()),
2594 * but it is only used for events with AUX ring buffer, and such
2595 * events will refuse to restart because of rb::aux_mmap_count==0,
2596 * see comments in perf_aux_output_begin().
2598 * Since this is happening on a event-local CPU, no trace is lost
2602 event
->pmu
->start(event
, 0);
2607 static int perf_event_stop(struct perf_event
*event
, int restart
)
2609 struct stop_event_data sd
= {
2616 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2619 /* matches smp_wmb() in event_sched_in() */
2623 * We only want to restart ACTIVE events, so if the event goes
2624 * inactive here (event->oncpu==-1), there's nothing more to do;
2625 * fall through with ret==-ENXIO.
2627 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2628 __perf_event_stop
, &sd
);
2629 } while (ret
== -EAGAIN
);
2635 * In order to contain the amount of racy and tricky in the address filter
2636 * configuration management, it is a two part process:
2638 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2639 * we update the addresses of corresponding vmas in
2640 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2641 * (p2) when an event is scheduled in (pmu::add), it calls
2642 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2643 * if the generation has changed since the previous call.
2645 * If (p1) happens while the event is active, we restart it to force (p2).
2647 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2648 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2650 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2651 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2653 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2656 void perf_event_addr_filters_sync(struct perf_event
*event
)
2658 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2660 if (!has_addr_filter(event
))
2663 raw_spin_lock(&ifh
->lock
);
2664 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2665 event
->pmu
->addr_filters_sync(event
);
2666 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2668 raw_spin_unlock(&ifh
->lock
);
2670 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2672 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2675 * not supported on inherited events
2677 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2680 atomic_add(refresh
, &event
->event_limit
);
2681 _perf_event_enable(event
);
2687 * See perf_event_disable()
2689 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2691 struct perf_event_context
*ctx
;
2694 ctx
= perf_event_ctx_lock(event
);
2695 ret
= _perf_event_refresh(event
, refresh
);
2696 perf_event_ctx_unlock(event
, ctx
);
2700 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2702 static void ctx_sched_out(struct perf_event_context
*ctx
,
2703 struct perf_cpu_context
*cpuctx
,
2704 enum event_type_t event_type
)
2706 int is_active
= ctx
->is_active
;
2707 struct perf_event
*event
;
2709 lockdep_assert_held(&ctx
->lock
);
2711 if (likely(!ctx
->nr_events
)) {
2713 * See __perf_remove_from_context().
2715 WARN_ON_ONCE(ctx
->is_active
);
2717 WARN_ON_ONCE(cpuctx
->task_ctx
);
2721 ctx
->is_active
&= ~event_type
;
2722 if (!(ctx
->is_active
& EVENT_ALL
))
2726 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2727 if (!ctx
->is_active
)
2728 cpuctx
->task_ctx
= NULL
;
2732 * Always update time if it was set; not only when it changes.
2733 * Otherwise we can 'forget' to update time for any but the last
2734 * context we sched out. For example:
2736 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2737 * ctx_sched_out(.event_type = EVENT_PINNED)
2739 * would only update time for the pinned events.
2741 if (is_active
& EVENT_TIME
) {
2742 /* update (and stop) ctx time */
2743 update_context_time(ctx
);
2744 update_cgrp_time_from_cpuctx(cpuctx
);
2747 is_active
^= ctx
->is_active
; /* changed bits */
2749 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2752 perf_pmu_disable(ctx
->pmu
);
2753 if (is_active
& EVENT_PINNED
) {
2754 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2755 group_sched_out(event
, cpuctx
, ctx
);
2758 if (is_active
& EVENT_FLEXIBLE
) {
2759 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2760 group_sched_out(event
, cpuctx
, ctx
);
2762 perf_pmu_enable(ctx
->pmu
);
2766 * Test whether two contexts are equivalent, i.e. whether they have both been
2767 * cloned from the same version of the same context.
2769 * Equivalence is measured using a generation number in the context that is
2770 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2771 * and list_del_event().
2773 static int context_equiv(struct perf_event_context
*ctx1
,
2774 struct perf_event_context
*ctx2
)
2776 lockdep_assert_held(&ctx1
->lock
);
2777 lockdep_assert_held(&ctx2
->lock
);
2779 /* Pinning disables the swap optimization */
2780 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2783 /* If ctx1 is the parent of ctx2 */
2784 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2787 /* If ctx2 is the parent of ctx1 */
2788 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2792 * If ctx1 and ctx2 have the same parent; we flatten the parent
2793 * hierarchy, see perf_event_init_context().
2795 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2796 ctx1
->parent_gen
== ctx2
->parent_gen
)
2803 static void __perf_event_sync_stat(struct perf_event
*event
,
2804 struct perf_event
*next_event
)
2808 if (!event
->attr
.inherit_stat
)
2812 * Update the event value, we cannot use perf_event_read()
2813 * because we're in the middle of a context switch and have IRQs
2814 * disabled, which upsets smp_call_function_single(), however
2815 * we know the event must be on the current CPU, therefore we
2816 * don't need to use it.
2818 switch (event
->state
) {
2819 case PERF_EVENT_STATE_ACTIVE
:
2820 event
->pmu
->read(event
);
2823 case PERF_EVENT_STATE_INACTIVE
:
2824 update_event_times(event
);
2832 * In order to keep per-task stats reliable we need to flip the event
2833 * values when we flip the contexts.
2835 value
= local64_read(&next_event
->count
);
2836 value
= local64_xchg(&event
->count
, value
);
2837 local64_set(&next_event
->count
, value
);
2839 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2840 swap(event
->total_time_running
, next_event
->total_time_running
);
2843 * Since we swizzled the values, update the user visible data too.
2845 perf_event_update_userpage(event
);
2846 perf_event_update_userpage(next_event
);
2849 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2850 struct perf_event_context
*next_ctx
)
2852 struct perf_event
*event
, *next_event
;
2857 update_context_time(ctx
);
2859 event
= list_first_entry(&ctx
->event_list
,
2860 struct perf_event
, event_entry
);
2862 next_event
= list_first_entry(&next_ctx
->event_list
,
2863 struct perf_event
, event_entry
);
2865 while (&event
->event_entry
!= &ctx
->event_list
&&
2866 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2868 __perf_event_sync_stat(event
, next_event
);
2870 event
= list_next_entry(event
, event_entry
);
2871 next_event
= list_next_entry(next_event
, event_entry
);
2875 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2876 struct task_struct
*next
)
2878 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2879 struct perf_event_context
*next_ctx
;
2880 struct perf_event_context
*parent
, *next_parent
;
2881 struct perf_cpu_context
*cpuctx
;
2887 cpuctx
= __get_cpu_context(ctx
);
2888 if (!cpuctx
->task_ctx
)
2892 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2896 parent
= rcu_dereference(ctx
->parent_ctx
);
2897 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2899 /* If neither context have a parent context; they cannot be clones. */
2900 if (!parent
&& !next_parent
)
2903 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2905 * Looks like the two contexts are clones, so we might be
2906 * able to optimize the context switch. We lock both
2907 * contexts and check that they are clones under the
2908 * lock (including re-checking that neither has been
2909 * uncloned in the meantime). It doesn't matter which
2910 * order we take the locks because no other cpu could
2911 * be trying to lock both of these tasks.
2913 raw_spin_lock(&ctx
->lock
);
2914 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2915 if (context_equiv(ctx
, next_ctx
)) {
2916 WRITE_ONCE(ctx
->task
, next
);
2917 WRITE_ONCE(next_ctx
->task
, task
);
2919 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2922 * RCU_INIT_POINTER here is safe because we've not
2923 * modified the ctx and the above modification of
2924 * ctx->task and ctx->task_ctx_data are immaterial
2925 * since those values are always verified under
2926 * ctx->lock which we're now holding.
2928 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2929 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2933 perf_event_sync_stat(ctx
, next_ctx
);
2935 raw_spin_unlock(&next_ctx
->lock
);
2936 raw_spin_unlock(&ctx
->lock
);
2942 raw_spin_lock(&ctx
->lock
);
2943 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
2944 raw_spin_unlock(&ctx
->lock
);
2948 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
2950 void perf_sched_cb_dec(struct pmu
*pmu
)
2952 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2954 this_cpu_dec(perf_sched_cb_usages
);
2956 if (!--cpuctx
->sched_cb_usage
)
2957 list_del(&cpuctx
->sched_cb_entry
);
2961 void perf_sched_cb_inc(struct pmu
*pmu
)
2963 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2965 if (!cpuctx
->sched_cb_usage
++)
2966 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
2968 this_cpu_inc(perf_sched_cb_usages
);
2972 * This function provides the context switch callback to the lower code
2973 * layer. It is invoked ONLY when the context switch callback is enabled.
2975 * This callback is relevant even to per-cpu events; for example multi event
2976 * PEBS requires this to provide PID/TID information. This requires we flush
2977 * all queued PEBS records before we context switch to a new task.
2979 static void perf_pmu_sched_task(struct task_struct
*prev
,
2980 struct task_struct
*next
,
2983 struct perf_cpu_context
*cpuctx
;
2989 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
2990 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
2992 if (WARN_ON_ONCE(!pmu
->sched_task
))
2995 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2996 perf_pmu_disable(pmu
);
2998 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3000 perf_pmu_enable(pmu
);
3001 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3005 static void perf_event_switch(struct task_struct
*task
,
3006 struct task_struct
*next_prev
, bool sched_in
);
3008 #define for_each_task_context_nr(ctxn) \
3009 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3012 * Called from scheduler to remove the events of the current task,
3013 * with interrupts disabled.
3015 * We stop each event and update the event value in event->count.
3017 * This does not protect us against NMI, but disable()
3018 * sets the disabled bit in the control field of event _before_
3019 * accessing the event control register. If a NMI hits, then it will
3020 * not restart the event.
3022 void __perf_event_task_sched_out(struct task_struct
*task
,
3023 struct task_struct
*next
)
3027 if (__this_cpu_read(perf_sched_cb_usages
))
3028 perf_pmu_sched_task(task
, next
, false);
3030 if (atomic_read(&nr_switch_events
))
3031 perf_event_switch(task
, next
, false);
3033 for_each_task_context_nr(ctxn
)
3034 perf_event_context_sched_out(task
, ctxn
, next
);
3037 * if cgroup events exist on this CPU, then we need
3038 * to check if we have to switch out PMU state.
3039 * cgroup event are system-wide mode only
3041 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3042 perf_cgroup_sched_out(task
, next
);
3046 * Called with IRQs disabled
3048 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3049 enum event_type_t event_type
)
3051 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3055 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3056 struct perf_cpu_context
*cpuctx
)
3058 struct perf_event
*event
;
3060 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
3061 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3063 if (!event_filter_match(event
))
3066 /* may need to reset tstamp_enabled */
3067 if (is_cgroup_event(event
))
3068 perf_cgroup_mark_enabled(event
, ctx
);
3070 if (group_can_go_on(event
, cpuctx
, 1))
3071 group_sched_in(event
, cpuctx
, ctx
);
3074 * If this pinned group hasn't been scheduled,
3075 * put it in error state.
3077 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3078 update_group_times(event
);
3079 event
->state
= PERF_EVENT_STATE_ERROR
;
3085 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3086 struct perf_cpu_context
*cpuctx
)
3088 struct perf_event
*event
;
3091 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3092 /* Ignore events in OFF or ERROR state */
3093 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3096 * Listen to the 'cpu' scheduling filter constraint
3099 if (!event_filter_match(event
))
3102 /* may need to reset tstamp_enabled */
3103 if (is_cgroup_event(event
))
3104 perf_cgroup_mark_enabled(event
, ctx
);
3106 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3107 if (group_sched_in(event
, cpuctx
, ctx
))
3114 ctx_sched_in(struct perf_event_context
*ctx
,
3115 struct perf_cpu_context
*cpuctx
,
3116 enum event_type_t event_type
,
3117 struct task_struct
*task
)
3119 int is_active
= ctx
->is_active
;
3122 lockdep_assert_held(&ctx
->lock
);
3124 if (likely(!ctx
->nr_events
))
3127 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3130 cpuctx
->task_ctx
= ctx
;
3132 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3135 is_active
^= ctx
->is_active
; /* changed bits */
3137 if (is_active
& EVENT_TIME
) {
3138 /* start ctx time */
3140 ctx
->timestamp
= now
;
3141 perf_cgroup_set_timestamp(task
, ctx
);
3145 * First go through the list and put on any pinned groups
3146 * in order to give them the best chance of going on.
3148 if (is_active
& EVENT_PINNED
)
3149 ctx_pinned_sched_in(ctx
, cpuctx
);
3151 /* Then walk through the lower prio flexible groups */
3152 if (is_active
& EVENT_FLEXIBLE
)
3153 ctx_flexible_sched_in(ctx
, cpuctx
);
3156 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3157 enum event_type_t event_type
,
3158 struct task_struct
*task
)
3160 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3162 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3165 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3166 struct task_struct
*task
)
3168 struct perf_cpu_context
*cpuctx
;
3170 cpuctx
= __get_cpu_context(ctx
);
3171 if (cpuctx
->task_ctx
== ctx
)
3174 perf_ctx_lock(cpuctx
, ctx
);
3175 perf_pmu_disable(ctx
->pmu
);
3177 * We want to keep the following priority order:
3178 * cpu pinned (that don't need to move), task pinned,
3179 * cpu flexible, task flexible.
3181 * However, if task's ctx is not carrying any pinned
3182 * events, no need to flip the cpuctx's events around.
3184 if (!list_empty(&ctx
->pinned_groups
))
3185 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3186 perf_event_sched_in(cpuctx
, ctx
, task
);
3187 perf_pmu_enable(ctx
->pmu
);
3188 perf_ctx_unlock(cpuctx
, ctx
);
3192 * Called from scheduler to add the events of the current task
3193 * with interrupts disabled.
3195 * We restore the event value and then enable it.
3197 * This does not protect us against NMI, but enable()
3198 * sets the enabled bit in the control field of event _before_
3199 * accessing the event control register. If a NMI hits, then it will
3200 * keep the event running.
3202 void __perf_event_task_sched_in(struct task_struct
*prev
,
3203 struct task_struct
*task
)
3205 struct perf_event_context
*ctx
;
3209 * If cgroup events exist on this CPU, then we need to check if we have
3210 * to switch in PMU state; cgroup event are system-wide mode only.
3212 * Since cgroup events are CPU events, we must schedule these in before
3213 * we schedule in the task events.
3215 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3216 perf_cgroup_sched_in(prev
, task
);
3218 for_each_task_context_nr(ctxn
) {
3219 ctx
= task
->perf_event_ctxp
[ctxn
];
3223 perf_event_context_sched_in(ctx
, task
);
3226 if (atomic_read(&nr_switch_events
))
3227 perf_event_switch(task
, prev
, true);
3229 if (__this_cpu_read(perf_sched_cb_usages
))
3230 perf_pmu_sched_task(prev
, task
, true);
3233 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3235 u64 frequency
= event
->attr
.sample_freq
;
3236 u64 sec
= NSEC_PER_SEC
;
3237 u64 divisor
, dividend
;
3239 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3241 count_fls
= fls64(count
);
3242 nsec_fls
= fls64(nsec
);
3243 frequency_fls
= fls64(frequency
);
3247 * We got @count in @nsec, with a target of sample_freq HZ
3248 * the target period becomes:
3251 * period = -------------------
3252 * @nsec * sample_freq
3257 * Reduce accuracy by one bit such that @a and @b converge
3258 * to a similar magnitude.
3260 #define REDUCE_FLS(a, b) \
3262 if (a##_fls > b##_fls) { \
3272 * Reduce accuracy until either term fits in a u64, then proceed with
3273 * the other, so that finally we can do a u64/u64 division.
3275 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3276 REDUCE_FLS(nsec
, frequency
);
3277 REDUCE_FLS(sec
, count
);
3280 if (count_fls
+ sec_fls
> 64) {
3281 divisor
= nsec
* frequency
;
3283 while (count_fls
+ sec_fls
> 64) {
3284 REDUCE_FLS(count
, sec
);
3288 dividend
= count
* sec
;
3290 dividend
= count
* sec
;
3292 while (nsec_fls
+ frequency_fls
> 64) {
3293 REDUCE_FLS(nsec
, frequency
);
3297 divisor
= nsec
* frequency
;
3303 return div64_u64(dividend
, divisor
);
3306 static DEFINE_PER_CPU(int, perf_throttled_count
);
3307 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3309 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3311 struct hw_perf_event
*hwc
= &event
->hw
;
3312 s64 period
, sample_period
;
3315 period
= perf_calculate_period(event
, nsec
, count
);
3317 delta
= (s64
)(period
- hwc
->sample_period
);
3318 delta
= (delta
+ 7) / 8; /* low pass filter */
3320 sample_period
= hwc
->sample_period
+ delta
;
3325 hwc
->sample_period
= sample_period
;
3327 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3329 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3331 local64_set(&hwc
->period_left
, 0);
3334 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3339 * combine freq adjustment with unthrottling to avoid two passes over the
3340 * events. At the same time, make sure, having freq events does not change
3341 * the rate of unthrottling as that would introduce bias.
3343 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3346 struct perf_event
*event
;
3347 struct hw_perf_event
*hwc
;
3348 u64 now
, period
= TICK_NSEC
;
3352 * only need to iterate over all events iff:
3353 * - context have events in frequency mode (needs freq adjust)
3354 * - there are events to unthrottle on this cpu
3356 if (!(ctx
->nr_freq
|| needs_unthr
))
3359 raw_spin_lock(&ctx
->lock
);
3360 perf_pmu_disable(ctx
->pmu
);
3362 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3363 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3366 if (!event_filter_match(event
))
3369 perf_pmu_disable(event
->pmu
);
3373 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3374 hwc
->interrupts
= 0;
3375 perf_log_throttle(event
, 1);
3376 event
->pmu
->start(event
, 0);
3379 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3383 * stop the event and update event->count
3385 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3387 now
= local64_read(&event
->count
);
3388 delta
= now
- hwc
->freq_count_stamp
;
3389 hwc
->freq_count_stamp
= now
;
3393 * reload only if value has changed
3394 * we have stopped the event so tell that
3395 * to perf_adjust_period() to avoid stopping it
3399 perf_adjust_period(event
, period
, delta
, false);
3401 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3403 perf_pmu_enable(event
->pmu
);
3406 perf_pmu_enable(ctx
->pmu
);
3407 raw_spin_unlock(&ctx
->lock
);
3411 * Round-robin a context's events:
3413 static void rotate_ctx(struct perf_event_context
*ctx
)
3416 * Rotate the first entry last of non-pinned groups. Rotation might be
3417 * disabled by the inheritance code.
3419 if (!ctx
->rotate_disable
)
3420 list_rotate_left(&ctx
->flexible_groups
);
3423 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3425 struct perf_event_context
*ctx
= NULL
;
3428 if (cpuctx
->ctx
.nr_events
) {
3429 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3433 ctx
= cpuctx
->task_ctx
;
3434 if (ctx
&& ctx
->nr_events
) {
3435 if (ctx
->nr_events
!= ctx
->nr_active
)
3442 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3443 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3445 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3447 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3449 rotate_ctx(&cpuctx
->ctx
);
3453 perf_event_sched_in(cpuctx
, ctx
, current
);
3455 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3456 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3462 void perf_event_task_tick(void)
3464 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3465 struct perf_event_context
*ctx
, *tmp
;
3468 WARN_ON(!irqs_disabled());
3470 __this_cpu_inc(perf_throttled_seq
);
3471 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3472 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3474 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3475 perf_adjust_freq_unthr_context(ctx
, throttled
);
3478 static int event_enable_on_exec(struct perf_event
*event
,
3479 struct perf_event_context
*ctx
)
3481 if (!event
->attr
.enable_on_exec
)
3484 event
->attr
.enable_on_exec
= 0;
3485 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3488 __perf_event_mark_enabled(event
);
3494 * Enable all of a task's events that have been marked enable-on-exec.
3495 * This expects task == current.
3497 static void perf_event_enable_on_exec(int ctxn
)
3499 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3500 enum event_type_t event_type
= 0;
3501 struct perf_cpu_context
*cpuctx
;
3502 struct perf_event
*event
;
3503 unsigned long flags
;
3506 local_irq_save(flags
);
3507 ctx
= current
->perf_event_ctxp
[ctxn
];
3508 if (!ctx
|| !ctx
->nr_events
)
3511 cpuctx
= __get_cpu_context(ctx
);
3512 perf_ctx_lock(cpuctx
, ctx
);
3513 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3514 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3515 enabled
|= event_enable_on_exec(event
, ctx
);
3516 event_type
|= get_event_type(event
);
3520 * Unclone and reschedule this context if we enabled any event.
3523 clone_ctx
= unclone_ctx(ctx
);
3524 ctx_resched(cpuctx
, ctx
, event_type
);
3526 perf_ctx_unlock(cpuctx
, ctx
);
3529 local_irq_restore(flags
);
3535 struct perf_read_data
{
3536 struct perf_event
*event
;
3541 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3543 u16 local_pkg
, event_pkg
;
3545 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3546 int local_cpu
= smp_processor_id();
3548 event_pkg
= topology_physical_package_id(event_cpu
);
3549 local_pkg
= topology_physical_package_id(local_cpu
);
3551 if (event_pkg
== local_pkg
)
3559 * Cross CPU call to read the hardware event
3561 static void __perf_event_read(void *info
)
3563 struct perf_read_data
*data
= info
;
3564 struct perf_event
*sub
, *event
= data
->event
;
3565 struct perf_event_context
*ctx
= event
->ctx
;
3566 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3567 struct pmu
*pmu
= event
->pmu
;
3570 * If this is a task context, we need to check whether it is
3571 * the current task context of this cpu. If not it has been
3572 * scheduled out before the smp call arrived. In that case
3573 * event->count would have been updated to a recent sample
3574 * when the event was scheduled out.
3576 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3579 raw_spin_lock(&ctx
->lock
);
3580 if (ctx
->is_active
) {
3581 update_context_time(ctx
);
3582 update_cgrp_time_from_event(event
);
3585 update_event_times(event
);
3586 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3595 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3599 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3600 update_event_times(sub
);
3601 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3603 * Use sibling's PMU rather than @event's since
3604 * sibling could be on different (eg: software) PMU.
3606 sub
->pmu
->read(sub
);
3610 data
->ret
= pmu
->commit_txn(pmu
);
3613 raw_spin_unlock(&ctx
->lock
);
3616 static inline u64
perf_event_count(struct perf_event
*event
)
3618 if (event
->pmu
->count
)
3619 return event
->pmu
->count(event
);
3621 return __perf_event_count(event
);
3625 * NMI-safe method to read a local event, that is an event that
3627 * - either for the current task, or for this CPU
3628 * - does not have inherit set, for inherited task events
3629 * will not be local and we cannot read them atomically
3630 * - must not have a pmu::count method
3632 u64
perf_event_read_local(struct perf_event
*event
)
3634 unsigned long flags
;
3638 * Disabling interrupts avoids all counter scheduling (context
3639 * switches, timer based rotation and IPIs).
3641 local_irq_save(flags
);
3643 /* If this is a per-task event, it must be for current */
3644 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3645 event
->hw
.target
!= current
);
3647 /* If this is a per-CPU event, it must be for this CPU */
3648 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3649 event
->cpu
!= smp_processor_id());
3652 * It must not be an event with inherit set, we cannot read
3653 * all child counters from atomic context.
3655 WARN_ON_ONCE(event
->attr
.inherit
);
3658 * It must not have a pmu::count method, those are not
3661 WARN_ON_ONCE(event
->pmu
->count
);
3664 * If the event is currently on this CPU, its either a per-task event,
3665 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3668 if (event
->oncpu
== smp_processor_id())
3669 event
->pmu
->read(event
);
3671 val
= local64_read(&event
->count
);
3672 local_irq_restore(flags
);
3677 static int perf_event_read(struct perf_event
*event
, bool group
)
3679 int event_cpu
, ret
= 0;
3682 * If event is enabled and currently active on a CPU, update the
3683 * value in the event structure:
3685 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3686 struct perf_read_data data
= {
3692 event_cpu
= READ_ONCE(event
->oncpu
);
3693 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3697 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
3700 * Purposely ignore the smp_call_function_single() return
3703 * If event_cpu isn't a valid CPU it means the event got
3704 * scheduled out and that will have updated the event count.
3706 * Therefore, either way, we'll have an up-to-date event count
3709 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
3712 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3713 struct perf_event_context
*ctx
= event
->ctx
;
3714 unsigned long flags
;
3716 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3718 * may read while context is not active
3719 * (e.g., thread is blocked), in that case
3720 * we cannot update context time
3722 if (ctx
->is_active
) {
3723 update_context_time(ctx
);
3724 update_cgrp_time_from_event(event
);
3727 update_group_times(event
);
3729 update_event_times(event
);
3730 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3737 * Initialize the perf_event context in a task_struct:
3739 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3741 raw_spin_lock_init(&ctx
->lock
);
3742 mutex_init(&ctx
->mutex
);
3743 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3744 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3745 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3746 INIT_LIST_HEAD(&ctx
->event_list
);
3747 atomic_set(&ctx
->refcount
, 1);
3750 static struct perf_event_context
*
3751 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3753 struct perf_event_context
*ctx
;
3755 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3759 __perf_event_init_context(ctx
);
3762 get_task_struct(task
);
3769 static struct task_struct
*
3770 find_lively_task_by_vpid(pid_t vpid
)
3772 struct task_struct
*task
;
3778 task
= find_task_by_vpid(vpid
);
3780 get_task_struct(task
);
3784 return ERR_PTR(-ESRCH
);
3790 * Returns a matching context with refcount and pincount.
3792 static struct perf_event_context
*
3793 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3794 struct perf_event
*event
)
3796 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3797 struct perf_cpu_context
*cpuctx
;
3798 void *task_ctx_data
= NULL
;
3799 unsigned long flags
;
3801 int cpu
= event
->cpu
;
3804 /* Must be root to operate on a CPU event: */
3805 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3806 return ERR_PTR(-EACCES
);
3809 * We could be clever and allow to attach a event to an
3810 * offline CPU and activate it when the CPU comes up, but
3813 if (!cpu_online(cpu
))
3814 return ERR_PTR(-ENODEV
);
3816 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3825 ctxn
= pmu
->task_ctx_nr
;
3829 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3830 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3831 if (!task_ctx_data
) {
3838 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3840 clone_ctx
= unclone_ctx(ctx
);
3843 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3844 ctx
->task_ctx_data
= task_ctx_data
;
3845 task_ctx_data
= NULL
;
3847 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3852 ctx
= alloc_perf_context(pmu
, task
);
3857 if (task_ctx_data
) {
3858 ctx
->task_ctx_data
= task_ctx_data
;
3859 task_ctx_data
= NULL
;
3863 mutex_lock(&task
->perf_event_mutex
);
3865 * If it has already passed perf_event_exit_task().
3866 * we must see PF_EXITING, it takes this mutex too.
3868 if (task
->flags
& PF_EXITING
)
3870 else if (task
->perf_event_ctxp
[ctxn
])
3875 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3877 mutex_unlock(&task
->perf_event_mutex
);
3879 if (unlikely(err
)) {
3888 kfree(task_ctx_data
);
3892 kfree(task_ctx_data
);
3893 return ERR_PTR(err
);
3896 static void perf_event_free_filter(struct perf_event
*event
);
3897 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3899 static void free_event_rcu(struct rcu_head
*head
)
3901 struct perf_event
*event
;
3903 event
= container_of(head
, struct perf_event
, rcu_head
);
3905 put_pid_ns(event
->ns
);
3906 perf_event_free_filter(event
);
3910 static void ring_buffer_attach(struct perf_event
*event
,
3911 struct ring_buffer
*rb
);
3913 static void detach_sb_event(struct perf_event
*event
)
3915 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3917 raw_spin_lock(&pel
->lock
);
3918 list_del_rcu(&event
->sb_list
);
3919 raw_spin_unlock(&pel
->lock
);
3922 static bool is_sb_event(struct perf_event
*event
)
3924 struct perf_event_attr
*attr
= &event
->attr
;
3929 if (event
->attach_state
& PERF_ATTACH_TASK
)
3932 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3933 attr
->comm
|| attr
->comm_exec
||
3935 attr
->context_switch
)
3940 static void unaccount_pmu_sb_event(struct perf_event
*event
)
3942 if (is_sb_event(event
))
3943 detach_sb_event(event
);
3946 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3951 if (is_cgroup_event(event
))
3952 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3955 #ifdef CONFIG_NO_HZ_FULL
3956 static DEFINE_SPINLOCK(nr_freq_lock
);
3959 static void unaccount_freq_event_nohz(void)
3961 #ifdef CONFIG_NO_HZ_FULL
3962 spin_lock(&nr_freq_lock
);
3963 if (atomic_dec_and_test(&nr_freq_events
))
3964 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3965 spin_unlock(&nr_freq_lock
);
3969 static void unaccount_freq_event(void)
3971 if (tick_nohz_full_enabled())
3972 unaccount_freq_event_nohz();
3974 atomic_dec(&nr_freq_events
);
3977 static void unaccount_event(struct perf_event
*event
)
3984 if (event
->attach_state
& PERF_ATTACH_TASK
)
3986 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3987 atomic_dec(&nr_mmap_events
);
3988 if (event
->attr
.comm
)
3989 atomic_dec(&nr_comm_events
);
3990 if (event
->attr
.task
)
3991 atomic_dec(&nr_task_events
);
3992 if (event
->attr
.freq
)
3993 unaccount_freq_event();
3994 if (event
->attr
.context_switch
) {
3996 atomic_dec(&nr_switch_events
);
3998 if (is_cgroup_event(event
))
4000 if (has_branch_stack(event
))
4004 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4005 schedule_delayed_work(&perf_sched_work
, HZ
);
4008 unaccount_event_cpu(event
, event
->cpu
);
4010 unaccount_pmu_sb_event(event
);
4013 static void perf_sched_delayed(struct work_struct
*work
)
4015 mutex_lock(&perf_sched_mutex
);
4016 if (atomic_dec_and_test(&perf_sched_count
))
4017 static_branch_disable(&perf_sched_events
);
4018 mutex_unlock(&perf_sched_mutex
);
4022 * The following implement mutual exclusion of events on "exclusive" pmus
4023 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4024 * at a time, so we disallow creating events that might conflict, namely:
4026 * 1) cpu-wide events in the presence of per-task events,
4027 * 2) per-task events in the presence of cpu-wide events,
4028 * 3) two matching events on the same context.
4030 * The former two cases are handled in the allocation path (perf_event_alloc(),
4031 * _free_event()), the latter -- before the first perf_install_in_context().
4033 static int exclusive_event_init(struct perf_event
*event
)
4035 struct pmu
*pmu
= event
->pmu
;
4037 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4041 * Prevent co-existence of per-task and cpu-wide events on the
4042 * same exclusive pmu.
4044 * Negative pmu::exclusive_cnt means there are cpu-wide
4045 * events on this "exclusive" pmu, positive means there are
4048 * Since this is called in perf_event_alloc() path, event::ctx
4049 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4050 * to mean "per-task event", because unlike other attach states it
4051 * never gets cleared.
4053 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4054 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4057 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4064 static void exclusive_event_destroy(struct perf_event
*event
)
4066 struct pmu
*pmu
= event
->pmu
;
4068 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4071 /* see comment in exclusive_event_init() */
4072 if (event
->attach_state
& PERF_ATTACH_TASK
)
4073 atomic_dec(&pmu
->exclusive_cnt
);
4075 atomic_inc(&pmu
->exclusive_cnt
);
4078 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4080 if ((e1
->pmu
== e2
->pmu
) &&
4081 (e1
->cpu
== e2
->cpu
||
4088 /* Called under the same ctx::mutex as perf_install_in_context() */
4089 static bool exclusive_event_installable(struct perf_event
*event
,
4090 struct perf_event_context
*ctx
)
4092 struct perf_event
*iter_event
;
4093 struct pmu
*pmu
= event
->pmu
;
4095 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4098 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4099 if (exclusive_event_match(iter_event
, event
))
4106 static void perf_addr_filters_splice(struct perf_event
*event
,
4107 struct list_head
*head
);
4109 static void _free_event(struct perf_event
*event
)
4111 irq_work_sync(&event
->pending
);
4113 unaccount_event(event
);
4117 * Can happen when we close an event with re-directed output.
4119 * Since we have a 0 refcount, perf_mmap_close() will skip
4120 * over us; possibly making our ring_buffer_put() the last.
4122 mutex_lock(&event
->mmap_mutex
);
4123 ring_buffer_attach(event
, NULL
);
4124 mutex_unlock(&event
->mmap_mutex
);
4127 if (is_cgroup_event(event
))
4128 perf_detach_cgroup(event
);
4130 if (!event
->parent
) {
4131 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4132 put_callchain_buffers();
4135 perf_event_free_bpf_prog(event
);
4136 perf_addr_filters_splice(event
, NULL
);
4137 kfree(event
->addr_filters_offs
);
4140 event
->destroy(event
);
4143 put_ctx(event
->ctx
);
4145 exclusive_event_destroy(event
);
4146 module_put(event
->pmu
->module
);
4148 call_rcu(&event
->rcu_head
, free_event_rcu
);
4152 * Used to free events which have a known refcount of 1, such as in error paths
4153 * where the event isn't exposed yet and inherited events.
4155 static void free_event(struct perf_event
*event
)
4157 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4158 "unexpected event refcount: %ld; ptr=%p\n",
4159 atomic_long_read(&event
->refcount
), event
)) {
4160 /* leak to avoid use-after-free */
4168 * Remove user event from the owner task.
4170 static void perf_remove_from_owner(struct perf_event
*event
)
4172 struct task_struct
*owner
;
4176 * Matches the smp_store_release() in perf_event_exit_task(). If we
4177 * observe !owner it means the list deletion is complete and we can
4178 * indeed free this event, otherwise we need to serialize on
4179 * owner->perf_event_mutex.
4181 owner
= lockless_dereference(event
->owner
);
4184 * Since delayed_put_task_struct() also drops the last
4185 * task reference we can safely take a new reference
4186 * while holding the rcu_read_lock().
4188 get_task_struct(owner
);
4194 * If we're here through perf_event_exit_task() we're already
4195 * holding ctx->mutex which would be an inversion wrt. the
4196 * normal lock order.
4198 * However we can safely take this lock because its the child
4201 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4204 * We have to re-check the event->owner field, if it is cleared
4205 * we raced with perf_event_exit_task(), acquiring the mutex
4206 * ensured they're done, and we can proceed with freeing the
4210 list_del_init(&event
->owner_entry
);
4211 smp_store_release(&event
->owner
, NULL
);
4213 mutex_unlock(&owner
->perf_event_mutex
);
4214 put_task_struct(owner
);
4218 static void put_event(struct perf_event
*event
)
4220 if (!atomic_long_dec_and_test(&event
->refcount
))
4227 * Kill an event dead; while event:refcount will preserve the event
4228 * object, it will not preserve its functionality. Once the last 'user'
4229 * gives up the object, we'll destroy the thing.
4231 int perf_event_release_kernel(struct perf_event
*event
)
4233 struct perf_event_context
*ctx
= event
->ctx
;
4234 struct perf_event
*child
, *tmp
;
4237 * If we got here through err_file: fput(event_file); we will not have
4238 * attached to a context yet.
4241 WARN_ON_ONCE(event
->attach_state
&
4242 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4246 if (!is_kernel_event(event
))
4247 perf_remove_from_owner(event
);
4249 ctx
= perf_event_ctx_lock(event
);
4250 WARN_ON_ONCE(ctx
->parent_ctx
);
4251 perf_remove_from_context(event
, DETACH_GROUP
);
4253 raw_spin_lock_irq(&ctx
->lock
);
4255 * Mark this even as STATE_DEAD, there is no external reference to it
4258 * Anybody acquiring event->child_mutex after the below loop _must_
4259 * also see this, most importantly inherit_event() which will avoid
4260 * placing more children on the list.
4262 * Thus this guarantees that we will in fact observe and kill _ALL_
4265 event
->state
= PERF_EVENT_STATE_DEAD
;
4266 raw_spin_unlock_irq(&ctx
->lock
);
4268 perf_event_ctx_unlock(event
, ctx
);
4271 mutex_lock(&event
->child_mutex
);
4272 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4275 * Cannot change, child events are not migrated, see the
4276 * comment with perf_event_ctx_lock_nested().
4278 ctx
= lockless_dereference(child
->ctx
);
4280 * Since child_mutex nests inside ctx::mutex, we must jump
4281 * through hoops. We start by grabbing a reference on the ctx.
4283 * Since the event cannot get freed while we hold the
4284 * child_mutex, the context must also exist and have a !0
4290 * Now that we have a ctx ref, we can drop child_mutex, and
4291 * acquire ctx::mutex without fear of it going away. Then we
4292 * can re-acquire child_mutex.
4294 mutex_unlock(&event
->child_mutex
);
4295 mutex_lock(&ctx
->mutex
);
4296 mutex_lock(&event
->child_mutex
);
4299 * Now that we hold ctx::mutex and child_mutex, revalidate our
4300 * state, if child is still the first entry, it didn't get freed
4301 * and we can continue doing so.
4303 tmp
= list_first_entry_or_null(&event
->child_list
,
4304 struct perf_event
, child_list
);
4306 perf_remove_from_context(child
, DETACH_GROUP
);
4307 list_del(&child
->child_list
);
4310 * This matches the refcount bump in inherit_event();
4311 * this can't be the last reference.
4316 mutex_unlock(&event
->child_mutex
);
4317 mutex_unlock(&ctx
->mutex
);
4321 mutex_unlock(&event
->child_mutex
);
4324 put_event(event
); /* Must be the 'last' reference */
4327 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4330 * Called when the last reference to the file is gone.
4332 static int perf_release(struct inode
*inode
, struct file
*file
)
4334 perf_event_release_kernel(file
->private_data
);
4338 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4340 struct perf_event
*child
;
4346 mutex_lock(&event
->child_mutex
);
4348 (void)perf_event_read(event
, false);
4349 total
+= perf_event_count(event
);
4351 *enabled
+= event
->total_time_enabled
+
4352 atomic64_read(&event
->child_total_time_enabled
);
4353 *running
+= event
->total_time_running
+
4354 atomic64_read(&event
->child_total_time_running
);
4356 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4357 (void)perf_event_read(child
, false);
4358 total
+= perf_event_count(child
);
4359 *enabled
+= child
->total_time_enabled
;
4360 *running
+= child
->total_time_running
;
4362 mutex_unlock(&event
->child_mutex
);
4366 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4368 static int __perf_read_group_add(struct perf_event
*leader
,
4369 u64 read_format
, u64
*values
)
4371 struct perf_event
*sub
;
4372 int n
= 1; /* skip @nr */
4375 ret
= perf_event_read(leader
, true);
4380 * Since we co-schedule groups, {enabled,running} times of siblings
4381 * will be identical to those of the leader, so we only publish one
4384 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4385 values
[n
++] += leader
->total_time_enabled
+
4386 atomic64_read(&leader
->child_total_time_enabled
);
4389 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4390 values
[n
++] += leader
->total_time_running
+
4391 atomic64_read(&leader
->child_total_time_running
);
4395 * Write {count,id} tuples for every sibling.
4397 values
[n
++] += perf_event_count(leader
);
4398 if (read_format
& PERF_FORMAT_ID
)
4399 values
[n
++] = primary_event_id(leader
);
4401 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4402 values
[n
++] += perf_event_count(sub
);
4403 if (read_format
& PERF_FORMAT_ID
)
4404 values
[n
++] = primary_event_id(sub
);
4410 static int perf_read_group(struct perf_event
*event
,
4411 u64 read_format
, char __user
*buf
)
4413 struct perf_event
*leader
= event
->group_leader
, *child
;
4414 struct perf_event_context
*ctx
= leader
->ctx
;
4418 lockdep_assert_held(&ctx
->mutex
);
4420 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4424 values
[0] = 1 + leader
->nr_siblings
;
4427 * By locking the child_mutex of the leader we effectively
4428 * lock the child list of all siblings.. XXX explain how.
4430 mutex_lock(&leader
->child_mutex
);
4432 ret
= __perf_read_group_add(leader
, read_format
, values
);
4436 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4437 ret
= __perf_read_group_add(child
, read_format
, values
);
4442 mutex_unlock(&leader
->child_mutex
);
4444 ret
= event
->read_size
;
4445 if (copy_to_user(buf
, values
, event
->read_size
))
4450 mutex_unlock(&leader
->child_mutex
);
4456 static int perf_read_one(struct perf_event
*event
,
4457 u64 read_format
, char __user
*buf
)
4459 u64 enabled
, running
;
4463 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4464 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4465 values
[n
++] = enabled
;
4466 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4467 values
[n
++] = running
;
4468 if (read_format
& PERF_FORMAT_ID
)
4469 values
[n
++] = primary_event_id(event
);
4471 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4474 return n
* sizeof(u64
);
4477 static bool is_event_hup(struct perf_event
*event
)
4481 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4484 mutex_lock(&event
->child_mutex
);
4485 no_children
= list_empty(&event
->child_list
);
4486 mutex_unlock(&event
->child_mutex
);
4491 * Read the performance event - simple non blocking version for now
4494 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4496 u64 read_format
= event
->attr
.read_format
;
4500 * Return end-of-file for a read on a event that is in
4501 * error state (i.e. because it was pinned but it couldn't be
4502 * scheduled on to the CPU at some point).
4504 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4507 if (count
< event
->read_size
)
4510 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4511 if (read_format
& PERF_FORMAT_GROUP
)
4512 ret
= perf_read_group(event
, read_format
, buf
);
4514 ret
= perf_read_one(event
, read_format
, buf
);
4520 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4522 struct perf_event
*event
= file
->private_data
;
4523 struct perf_event_context
*ctx
;
4526 ctx
= perf_event_ctx_lock(event
);
4527 ret
= __perf_read(event
, buf
, count
);
4528 perf_event_ctx_unlock(event
, ctx
);
4533 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4535 struct perf_event
*event
= file
->private_data
;
4536 struct ring_buffer
*rb
;
4537 unsigned int events
= POLLHUP
;
4539 poll_wait(file
, &event
->waitq
, wait
);
4541 if (is_event_hup(event
))
4545 * Pin the event->rb by taking event->mmap_mutex; otherwise
4546 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4548 mutex_lock(&event
->mmap_mutex
);
4551 events
= atomic_xchg(&rb
->poll
, 0);
4552 mutex_unlock(&event
->mmap_mutex
);
4556 static void _perf_event_reset(struct perf_event
*event
)
4558 (void)perf_event_read(event
, false);
4559 local64_set(&event
->count
, 0);
4560 perf_event_update_userpage(event
);
4564 * Holding the top-level event's child_mutex means that any
4565 * descendant process that has inherited this event will block
4566 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4567 * task existence requirements of perf_event_enable/disable.
4569 static void perf_event_for_each_child(struct perf_event
*event
,
4570 void (*func
)(struct perf_event
*))
4572 struct perf_event
*child
;
4574 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4576 mutex_lock(&event
->child_mutex
);
4578 list_for_each_entry(child
, &event
->child_list
, child_list
)
4580 mutex_unlock(&event
->child_mutex
);
4583 static void perf_event_for_each(struct perf_event
*event
,
4584 void (*func
)(struct perf_event
*))
4586 struct perf_event_context
*ctx
= event
->ctx
;
4587 struct perf_event
*sibling
;
4589 lockdep_assert_held(&ctx
->mutex
);
4591 event
= event
->group_leader
;
4593 perf_event_for_each_child(event
, func
);
4594 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4595 perf_event_for_each_child(sibling
, func
);
4598 static void __perf_event_period(struct perf_event
*event
,
4599 struct perf_cpu_context
*cpuctx
,
4600 struct perf_event_context
*ctx
,
4603 u64 value
= *((u64
*)info
);
4606 if (event
->attr
.freq
) {
4607 event
->attr
.sample_freq
= value
;
4609 event
->attr
.sample_period
= value
;
4610 event
->hw
.sample_period
= value
;
4613 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4615 perf_pmu_disable(ctx
->pmu
);
4617 * We could be throttled; unthrottle now to avoid the tick
4618 * trying to unthrottle while we already re-started the event.
4620 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4621 event
->hw
.interrupts
= 0;
4622 perf_log_throttle(event
, 1);
4624 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4627 local64_set(&event
->hw
.period_left
, 0);
4630 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4631 perf_pmu_enable(ctx
->pmu
);
4635 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4639 if (!is_sampling_event(event
))
4642 if (copy_from_user(&value
, arg
, sizeof(value
)))
4648 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4651 event_function_call(event
, __perf_event_period
, &value
);
4656 static const struct file_operations perf_fops
;
4658 static inline int perf_fget_light(int fd
, struct fd
*p
)
4660 struct fd f
= fdget(fd
);
4664 if (f
.file
->f_op
!= &perf_fops
) {
4672 static int perf_event_set_output(struct perf_event
*event
,
4673 struct perf_event
*output_event
);
4674 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4675 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4677 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4679 void (*func
)(struct perf_event
*);
4683 case PERF_EVENT_IOC_ENABLE
:
4684 func
= _perf_event_enable
;
4686 case PERF_EVENT_IOC_DISABLE
:
4687 func
= _perf_event_disable
;
4689 case PERF_EVENT_IOC_RESET
:
4690 func
= _perf_event_reset
;
4693 case PERF_EVENT_IOC_REFRESH
:
4694 return _perf_event_refresh(event
, arg
);
4696 case PERF_EVENT_IOC_PERIOD
:
4697 return perf_event_period(event
, (u64 __user
*)arg
);
4699 case PERF_EVENT_IOC_ID
:
4701 u64 id
= primary_event_id(event
);
4703 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4708 case PERF_EVENT_IOC_SET_OUTPUT
:
4712 struct perf_event
*output_event
;
4714 ret
= perf_fget_light(arg
, &output
);
4717 output_event
= output
.file
->private_data
;
4718 ret
= perf_event_set_output(event
, output_event
);
4721 ret
= perf_event_set_output(event
, NULL
);
4726 case PERF_EVENT_IOC_SET_FILTER
:
4727 return perf_event_set_filter(event
, (void __user
*)arg
);
4729 case PERF_EVENT_IOC_SET_BPF
:
4730 return perf_event_set_bpf_prog(event
, arg
);
4732 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4733 struct ring_buffer
*rb
;
4736 rb
= rcu_dereference(event
->rb
);
4737 if (!rb
|| !rb
->nr_pages
) {
4741 rb_toggle_paused(rb
, !!arg
);
4749 if (flags
& PERF_IOC_FLAG_GROUP
)
4750 perf_event_for_each(event
, func
);
4752 perf_event_for_each_child(event
, func
);
4757 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4759 struct perf_event
*event
= file
->private_data
;
4760 struct perf_event_context
*ctx
;
4763 ctx
= perf_event_ctx_lock(event
);
4764 ret
= _perf_ioctl(event
, cmd
, arg
);
4765 perf_event_ctx_unlock(event
, ctx
);
4770 #ifdef CONFIG_COMPAT
4771 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4774 switch (_IOC_NR(cmd
)) {
4775 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4776 case _IOC_NR(PERF_EVENT_IOC_ID
):
4777 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4778 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4779 cmd
&= ~IOCSIZE_MASK
;
4780 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4784 return perf_ioctl(file
, cmd
, arg
);
4787 # define perf_compat_ioctl NULL
4790 int perf_event_task_enable(void)
4792 struct perf_event_context
*ctx
;
4793 struct perf_event
*event
;
4795 mutex_lock(¤t
->perf_event_mutex
);
4796 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4797 ctx
= perf_event_ctx_lock(event
);
4798 perf_event_for_each_child(event
, _perf_event_enable
);
4799 perf_event_ctx_unlock(event
, ctx
);
4801 mutex_unlock(¤t
->perf_event_mutex
);
4806 int perf_event_task_disable(void)
4808 struct perf_event_context
*ctx
;
4809 struct perf_event
*event
;
4811 mutex_lock(¤t
->perf_event_mutex
);
4812 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4813 ctx
= perf_event_ctx_lock(event
);
4814 perf_event_for_each_child(event
, _perf_event_disable
);
4815 perf_event_ctx_unlock(event
, ctx
);
4817 mutex_unlock(¤t
->perf_event_mutex
);
4822 static int perf_event_index(struct perf_event
*event
)
4824 if (event
->hw
.state
& PERF_HES_STOPPED
)
4827 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4830 return event
->pmu
->event_idx(event
);
4833 static void calc_timer_values(struct perf_event
*event
,
4840 *now
= perf_clock();
4841 ctx_time
= event
->shadow_ctx_time
+ *now
;
4842 *enabled
= ctx_time
- event
->tstamp_enabled
;
4843 *running
= ctx_time
- event
->tstamp_running
;
4846 static void perf_event_init_userpage(struct perf_event
*event
)
4848 struct perf_event_mmap_page
*userpg
;
4849 struct ring_buffer
*rb
;
4852 rb
= rcu_dereference(event
->rb
);
4856 userpg
= rb
->user_page
;
4858 /* Allow new userspace to detect that bit 0 is deprecated */
4859 userpg
->cap_bit0_is_deprecated
= 1;
4860 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4861 userpg
->data_offset
= PAGE_SIZE
;
4862 userpg
->data_size
= perf_data_size(rb
);
4868 void __weak
arch_perf_update_userpage(
4869 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4874 * Callers need to ensure there can be no nesting of this function, otherwise
4875 * the seqlock logic goes bad. We can not serialize this because the arch
4876 * code calls this from NMI context.
4878 void perf_event_update_userpage(struct perf_event
*event
)
4880 struct perf_event_mmap_page
*userpg
;
4881 struct ring_buffer
*rb
;
4882 u64 enabled
, running
, now
;
4885 rb
= rcu_dereference(event
->rb
);
4890 * compute total_time_enabled, total_time_running
4891 * based on snapshot values taken when the event
4892 * was last scheduled in.
4894 * we cannot simply called update_context_time()
4895 * because of locking issue as we can be called in
4898 calc_timer_values(event
, &now
, &enabled
, &running
);
4900 userpg
= rb
->user_page
;
4902 * Disable preemption so as to not let the corresponding user-space
4903 * spin too long if we get preempted.
4908 userpg
->index
= perf_event_index(event
);
4909 userpg
->offset
= perf_event_count(event
);
4911 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4913 userpg
->time_enabled
= enabled
+
4914 atomic64_read(&event
->child_total_time_enabled
);
4916 userpg
->time_running
= running
+
4917 atomic64_read(&event
->child_total_time_running
);
4919 arch_perf_update_userpage(event
, userpg
, now
);
4928 static int perf_mmap_fault(struct vm_fault
*vmf
)
4930 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
4931 struct ring_buffer
*rb
;
4932 int ret
= VM_FAULT_SIGBUS
;
4934 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4935 if (vmf
->pgoff
== 0)
4941 rb
= rcu_dereference(event
->rb
);
4945 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4948 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4952 get_page(vmf
->page
);
4953 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
4954 vmf
->page
->index
= vmf
->pgoff
;
4963 static void ring_buffer_attach(struct perf_event
*event
,
4964 struct ring_buffer
*rb
)
4966 struct ring_buffer
*old_rb
= NULL
;
4967 unsigned long flags
;
4971 * Should be impossible, we set this when removing
4972 * event->rb_entry and wait/clear when adding event->rb_entry.
4974 WARN_ON_ONCE(event
->rcu_pending
);
4977 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4978 list_del_rcu(&event
->rb_entry
);
4979 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4981 event
->rcu_batches
= get_state_synchronize_rcu();
4982 event
->rcu_pending
= 1;
4986 if (event
->rcu_pending
) {
4987 cond_synchronize_rcu(event
->rcu_batches
);
4988 event
->rcu_pending
= 0;
4991 spin_lock_irqsave(&rb
->event_lock
, flags
);
4992 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4993 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4997 * Avoid racing with perf_mmap_close(AUX): stop the event
4998 * before swizzling the event::rb pointer; if it's getting
4999 * unmapped, its aux_mmap_count will be 0 and it won't
5000 * restart. See the comment in __perf_pmu_output_stop().
5002 * Data will inevitably be lost when set_output is done in
5003 * mid-air, but then again, whoever does it like this is
5004 * not in for the data anyway.
5007 perf_event_stop(event
, 0);
5009 rcu_assign_pointer(event
->rb
, rb
);
5012 ring_buffer_put(old_rb
);
5014 * Since we detached before setting the new rb, so that we
5015 * could attach the new rb, we could have missed a wakeup.
5018 wake_up_all(&event
->waitq
);
5022 static void ring_buffer_wakeup(struct perf_event
*event
)
5024 struct ring_buffer
*rb
;
5027 rb
= rcu_dereference(event
->rb
);
5029 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5030 wake_up_all(&event
->waitq
);
5035 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5037 struct ring_buffer
*rb
;
5040 rb
= rcu_dereference(event
->rb
);
5042 if (!atomic_inc_not_zero(&rb
->refcount
))
5050 void ring_buffer_put(struct ring_buffer
*rb
)
5052 if (!atomic_dec_and_test(&rb
->refcount
))
5055 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5057 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5060 static void perf_mmap_open(struct vm_area_struct
*vma
)
5062 struct perf_event
*event
= vma
->vm_file
->private_data
;
5064 atomic_inc(&event
->mmap_count
);
5065 atomic_inc(&event
->rb
->mmap_count
);
5068 atomic_inc(&event
->rb
->aux_mmap_count
);
5070 if (event
->pmu
->event_mapped
)
5071 event
->pmu
->event_mapped(event
);
5074 static void perf_pmu_output_stop(struct perf_event
*event
);
5077 * A buffer can be mmap()ed multiple times; either directly through the same
5078 * event, or through other events by use of perf_event_set_output().
5080 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5081 * the buffer here, where we still have a VM context. This means we need
5082 * to detach all events redirecting to us.
5084 static void perf_mmap_close(struct vm_area_struct
*vma
)
5086 struct perf_event
*event
= vma
->vm_file
->private_data
;
5088 struct ring_buffer
*rb
= ring_buffer_get(event
);
5089 struct user_struct
*mmap_user
= rb
->mmap_user
;
5090 int mmap_locked
= rb
->mmap_locked
;
5091 unsigned long size
= perf_data_size(rb
);
5093 if (event
->pmu
->event_unmapped
)
5094 event
->pmu
->event_unmapped(event
);
5097 * rb->aux_mmap_count will always drop before rb->mmap_count and
5098 * event->mmap_count, so it is ok to use event->mmap_mutex to
5099 * serialize with perf_mmap here.
5101 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5102 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5104 * Stop all AUX events that are writing to this buffer,
5105 * so that we can free its AUX pages and corresponding PMU
5106 * data. Note that after rb::aux_mmap_count dropped to zero,
5107 * they won't start any more (see perf_aux_output_begin()).
5109 perf_pmu_output_stop(event
);
5111 /* now it's safe to free the pages */
5112 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5113 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5115 /* this has to be the last one */
5117 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5119 mutex_unlock(&event
->mmap_mutex
);
5122 atomic_dec(&rb
->mmap_count
);
5124 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5127 ring_buffer_attach(event
, NULL
);
5128 mutex_unlock(&event
->mmap_mutex
);
5130 /* If there's still other mmap()s of this buffer, we're done. */
5131 if (atomic_read(&rb
->mmap_count
))
5135 * No other mmap()s, detach from all other events that might redirect
5136 * into the now unreachable buffer. Somewhat complicated by the
5137 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5141 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5142 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5144 * This event is en-route to free_event() which will
5145 * detach it and remove it from the list.
5151 mutex_lock(&event
->mmap_mutex
);
5153 * Check we didn't race with perf_event_set_output() which can
5154 * swizzle the rb from under us while we were waiting to
5155 * acquire mmap_mutex.
5157 * If we find a different rb; ignore this event, a next
5158 * iteration will no longer find it on the list. We have to
5159 * still restart the iteration to make sure we're not now
5160 * iterating the wrong list.
5162 if (event
->rb
== rb
)
5163 ring_buffer_attach(event
, NULL
);
5165 mutex_unlock(&event
->mmap_mutex
);
5169 * Restart the iteration; either we're on the wrong list or
5170 * destroyed its integrity by doing a deletion.
5177 * It could be there's still a few 0-ref events on the list; they'll
5178 * get cleaned up by free_event() -- they'll also still have their
5179 * ref on the rb and will free it whenever they are done with it.
5181 * Aside from that, this buffer is 'fully' detached and unmapped,
5182 * undo the VM accounting.
5185 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5186 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5187 free_uid(mmap_user
);
5190 ring_buffer_put(rb
); /* could be last */
5193 static const struct vm_operations_struct perf_mmap_vmops
= {
5194 .open
= perf_mmap_open
,
5195 .close
= perf_mmap_close
, /* non mergable */
5196 .fault
= perf_mmap_fault
,
5197 .page_mkwrite
= perf_mmap_fault
,
5200 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5202 struct perf_event
*event
= file
->private_data
;
5203 unsigned long user_locked
, user_lock_limit
;
5204 struct user_struct
*user
= current_user();
5205 unsigned long locked
, lock_limit
;
5206 struct ring_buffer
*rb
= NULL
;
5207 unsigned long vma_size
;
5208 unsigned long nr_pages
;
5209 long user_extra
= 0, extra
= 0;
5210 int ret
= 0, flags
= 0;
5213 * Don't allow mmap() of inherited per-task counters. This would
5214 * create a performance issue due to all children writing to the
5217 if (event
->cpu
== -1 && event
->attr
.inherit
)
5220 if (!(vma
->vm_flags
& VM_SHARED
))
5223 vma_size
= vma
->vm_end
- vma
->vm_start
;
5225 if (vma
->vm_pgoff
== 0) {
5226 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5229 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5230 * mapped, all subsequent mappings should have the same size
5231 * and offset. Must be above the normal perf buffer.
5233 u64 aux_offset
, aux_size
;
5238 nr_pages
= vma_size
/ PAGE_SIZE
;
5240 mutex_lock(&event
->mmap_mutex
);
5247 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
5248 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
5250 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5253 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5256 /* already mapped with a different offset */
5257 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5260 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5263 /* already mapped with a different size */
5264 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5267 if (!is_power_of_2(nr_pages
))
5270 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5273 if (rb_has_aux(rb
)) {
5274 atomic_inc(&rb
->aux_mmap_count
);
5279 atomic_set(&rb
->aux_mmap_count
, 1);
5280 user_extra
= nr_pages
;
5286 * If we have rb pages ensure they're a power-of-two number, so we
5287 * can do bitmasks instead of modulo.
5289 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5292 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5295 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5297 mutex_lock(&event
->mmap_mutex
);
5299 if (event
->rb
->nr_pages
!= nr_pages
) {
5304 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5306 * Raced against perf_mmap_close() through
5307 * perf_event_set_output(). Try again, hope for better
5310 mutex_unlock(&event
->mmap_mutex
);
5317 user_extra
= nr_pages
+ 1;
5320 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5323 * Increase the limit linearly with more CPUs:
5325 user_lock_limit
*= num_online_cpus();
5327 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5329 if (user_locked
> user_lock_limit
)
5330 extra
= user_locked
- user_lock_limit
;
5332 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5333 lock_limit
>>= PAGE_SHIFT
;
5334 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5336 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5337 !capable(CAP_IPC_LOCK
)) {
5342 WARN_ON(!rb
&& event
->rb
);
5344 if (vma
->vm_flags
& VM_WRITE
)
5345 flags
|= RING_BUFFER_WRITABLE
;
5348 rb
= rb_alloc(nr_pages
,
5349 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5357 atomic_set(&rb
->mmap_count
, 1);
5358 rb
->mmap_user
= get_current_user();
5359 rb
->mmap_locked
= extra
;
5361 ring_buffer_attach(event
, rb
);
5363 perf_event_init_userpage(event
);
5364 perf_event_update_userpage(event
);
5366 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5367 event
->attr
.aux_watermark
, flags
);
5369 rb
->aux_mmap_locked
= extra
;
5374 atomic_long_add(user_extra
, &user
->locked_vm
);
5375 vma
->vm_mm
->pinned_vm
+= extra
;
5377 atomic_inc(&event
->mmap_count
);
5379 atomic_dec(&rb
->mmap_count
);
5382 mutex_unlock(&event
->mmap_mutex
);
5385 * Since pinned accounting is per vm we cannot allow fork() to copy our
5388 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5389 vma
->vm_ops
= &perf_mmap_vmops
;
5391 if (event
->pmu
->event_mapped
)
5392 event
->pmu
->event_mapped(event
);
5397 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5399 struct inode
*inode
= file_inode(filp
);
5400 struct perf_event
*event
= filp
->private_data
;
5404 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5405 inode_unlock(inode
);
5413 static const struct file_operations perf_fops
= {
5414 .llseek
= no_llseek
,
5415 .release
= perf_release
,
5418 .unlocked_ioctl
= perf_ioctl
,
5419 .compat_ioctl
= perf_compat_ioctl
,
5421 .fasync
= perf_fasync
,
5427 * If there's data, ensure we set the poll() state and publish everything
5428 * to user-space before waking everybody up.
5431 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5433 /* only the parent has fasync state */
5435 event
= event
->parent
;
5436 return &event
->fasync
;
5439 void perf_event_wakeup(struct perf_event
*event
)
5441 ring_buffer_wakeup(event
);
5443 if (event
->pending_kill
) {
5444 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5445 event
->pending_kill
= 0;
5449 static void perf_pending_event(struct irq_work
*entry
)
5451 struct perf_event
*event
= container_of(entry
,
5452 struct perf_event
, pending
);
5455 rctx
= perf_swevent_get_recursion_context();
5457 * If we 'fail' here, that's OK, it means recursion is already disabled
5458 * and we won't recurse 'further'.
5461 if (event
->pending_disable
) {
5462 event
->pending_disable
= 0;
5463 perf_event_disable_local(event
);
5466 if (event
->pending_wakeup
) {
5467 event
->pending_wakeup
= 0;
5468 perf_event_wakeup(event
);
5472 perf_swevent_put_recursion_context(rctx
);
5476 * We assume there is only KVM supporting the callbacks.
5477 * Later on, we might change it to a list if there is
5478 * another virtualization implementation supporting the callbacks.
5480 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5482 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5484 perf_guest_cbs
= cbs
;
5487 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5489 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5491 perf_guest_cbs
= NULL
;
5494 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5497 perf_output_sample_regs(struct perf_output_handle
*handle
,
5498 struct pt_regs
*regs
, u64 mask
)
5501 DECLARE_BITMAP(_mask
, 64);
5503 bitmap_from_u64(_mask
, mask
);
5504 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5507 val
= perf_reg_value(regs
, bit
);
5508 perf_output_put(handle
, val
);
5512 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5513 struct pt_regs
*regs
,
5514 struct pt_regs
*regs_user_copy
)
5516 if (user_mode(regs
)) {
5517 regs_user
->abi
= perf_reg_abi(current
);
5518 regs_user
->regs
= regs
;
5519 } else if (current
->mm
) {
5520 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5522 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5523 regs_user
->regs
= NULL
;
5527 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5528 struct pt_regs
*regs
)
5530 regs_intr
->regs
= regs
;
5531 regs_intr
->abi
= perf_reg_abi(current
);
5536 * Get remaining task size from user stack pointer.
5538 * It'd be better to take stack vma map and limit this more
5539 * precisly, but there's no way to get it safely under interrupt,
5540 * so using TASK_SIZE as limit.
5542 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5544 unsigned long addr
= perf_user_stack_pointer(regs
);
5546 if (!addr
|| addr
>= TASK_SIZE
)
5549 return TASK_SIZE
- addr
;
5553 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5554 struct pt_regs
*regs
)
5558 /* No regs, no stack pointer, no dump. */
5563 * Check if we fit in with the requested stack size into the:
5565 * If we don't, we limit the size to the TASK_SIZE.
5567 * - remaining sample size
5568 * If we don't, we customize the stack size to
5569 * fit in to the remaining sample size.
5572 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5573 stack_size
= min(stack_size
, (u16
) task_size
);
5575 /* Current header size plus static size and dynamic size. */
5576 header_size
+= 2 * sizeof(u64
);
5578 /* Do we fit in with the current stack dump size? */
5579 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5581 * If we overflow the maximum size for the sample,
5582 * we customize the stack dump size to fit in.
5584 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5585 stack_size
= round_up(stack_size
, sizeof(u64
));
5592 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5593 struct pt_regs
*regs
)
5595 /* Case of a kernel thread, nothing to dump */
5598 perf_output_put(handle
, size
);
5607 * - the size requested by user or the best one we can fit
5608 * in to the sample max size
5610 * - user stack dump data
5612 * - the actual dumped size
5616 perf_output_put(handle
, dump_size
);
5619 sp
= perf_user_stack_pointer(regs
);
5620 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5621 dyn_size
= dump_size
- rem
;
5623 perf_output_skip(handle
, rem
);
5626 perf_output_put(handle
, dyn_size
);
5630 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5631 struct perf_sample_data
*data
,
5632 struct perf_event
*event
)
5634 u64 sample_type
= event
->attr
.sample_type
;
5636 data
->type
= sample_type
;
5637 header
->size
+= event
->id_header_size
;
5639 if (sample_type
& PERF_SAMPLE_TID
) {
5640 /* namespace issues */
5641 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5642 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5645 if (sample_type
& PERF_SAMPLE_TIME
)
5646 data
->time
= perf_event_clock(event
);
5648 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5649 data
->id
= primary_event_id(event
);
5651 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5652 data
->stream_id
= event
->id
;
5654 if (sample_type
& PERF_SAMPLE_CPU
) {
5655 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5656 data
->cpu_entry
.reserved
= 0;
5660 void perf_event_header__init_id(struct perf_event_header
*header
,
5661 struct perf_sample_data
*data
,
5662 struct perf_event
*event
)
5664 if (event
->attr
.sample_id_all
)
5665 __perf_event_header__init_id(header
, data
, event
);
5668 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5669 struct perf_sample_data
*data
)
5671 u64 sample_type
= data
->type
;
5673 if (sample_type
& PERF_SAMPLE_TID
)
5674 perf_output_put(handle
, data
->tid_entry
);
5676 if (sample_type
& PERF_SAMPLE_TIME
)
5677 perf_output_put(handle
, data
->time
);
5679 if (sample_type
& PERF_SAMPLE_ID
)
5680 perf_output_put(handle
, data
->id
);
5682 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5683 perf_output_put(handle
, data
->stream_id
);
5685 if (sample_type
& PERF_SAMPLE_CPU
)
5686 perf_output_put(handle
, data
->cpu_entry
);
5688 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5689 perf_output_put(handle
, data
->id
);
5692 void perf_event__output_id_sample(struct perf_event
*event
,
5693 struct perf_output_handle
*handle
,
5694 struct perf_sample_data
*sample
)
5696 if (event
->attr
.sample_id_all
)
5697 __perf_event__output_id_sample(handle
, sample
);
5700 static void perf_output_read_one(struct perf_output_handle
*handle
,
5701 struct perf_event
*event
,
5702 u64 enabled
, u64 running
)
5704 u64 read_format
= event
->attr
.read_format
;
5708 values
[n
++] = perf_event_count(event
);
5709 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5710 values
[n
++] = enabled
+
5711 atomic64_read(&event
->child_total_time_enabled
);
5713 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5714 values
[n
++] = running
+
5715 atomic64_read(&event
->child_total_time_running
);
5717 if (read_format
& PERF_FORMAT_ID
)
5718 values
[n
++] = primary_event_id(event
);
5720 __output_copy(handle
, values
, n
* sizeof(u64
));
5724 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5726 static void perf_output_read_group(struct perf_output_handle
*handle
,
5727 struct perf_event
*event
,
5728 u64 enabled
, u64 running
)
5730 struct perf_event
*leader
= event
->group_leader
, *sub
;
5731 u64 read_format
= event
->attr
.read_format
;
5735 values
[n
++] = 1 + leader
->nr_siblings
;
5737 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5738 values
[n
++] = enabled
;
5740 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5741 values
[n
++] = running
;
5743 if (leader
!= event
)
5744 leader
->pmu
->read(leader
);
5746 values
[n
++] = perf_event_count(leader
);
5747 if (read_format
& PERF_FORMAT_ID
)
5748 values
[n
++] = primary_event_id(leader
);
5750 __output_copy(handle
, values
, n
* sizeof(u64
));
5752 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5755 if ((sub
!= event
) &&
5756 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5757 sub
->pmu
->read(sub
);
5759 values
[n
++] = perf_event_count(sub
);
5760 if (read_format
& PERF_FORMAT_ID
)
5761 values
[n
++] = primary_event_id(sub
);
5763 __output_copy(handle
, values
, n
* sizeof(u64
));
5767 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5768 PERF_FORMAT_TOTAL_TIME_RUNNING)
5770 static void perf_output_read(struct perf_output_handle
*handle
,
5771 struct perf_event
*event
)
5773 u64 enabled
= 0, running
= 0, now
;
5774 u64 read_format
= event
->attr
.read_format
;
5777 * compute total_time_enabled, total_time_running
5778 * based on snapshot values taken when the event
5779 * was last scheduled in.
5781 * we cannot simply called update_context_time()
5782 * because of locking issue as we are called in
5785 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5786 calc_timer_values(event
, &now
, &enabled
, &running
);
5788 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5789 perf_output_read_group(handle
, event
, enabled
, running
);
5791 perf_output_read_one(handle
, event
, enabled
, running
);
5794 void perf_output_sample(struct perf_output_handle
*handle
,
5795 struct perf_event_header
*header
,
5796 struct perf_sample_data
*data
,
5797 struct perf_event
*event
)
5799 u64 sample_type
= data
->type
;
5801 perf_output_put(handle
, *header
);
5803 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5804 perf_output_put(handle
, data
->id
);
5806 if (sample_type
& PERF_SAMPLE_IP
)
5807 perf_output_put(handle
, data
->ip
);
5809 if (sample_type
& PERF_SAMPLE_TID
)
5810 perf_output_put(handle
, data
->tid_entry
);
5812 if (sample_type
& PERF_SAMPLE_TIME
)
5813 perf_output_put(handle
, data
->time
);
5815 if (sample_type
& PERF_SAMPLE_ADDR
)
5816 perf_output_put(handle
, data
->addr
);
5818 if (sample_type
& PERF_SAMPLE_ID
)
5819 perf_output_put(handle
, data
->id
);
5821 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5822 perf_output_put(handle
, data
->stream_id
);
5824 if (sample_type
& PERF_SAMPLE_CPU
)
5825 perf_output_put(handle
, data
->cpu_entry
);
5827 if (sample_type
& PERF_SAMPLE_PERIOD
)
5828 perf_output_put(handle
, data
->period
);
5830 if (sample_type
& PERF_SAMPLE_READ
)
5831 perf_output_read(handle
, event
);
5833 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5834 if (data
->callchain
) {
5837 if (data
->callchain
)
5838 size
+= data
->callchain
->nr
;
5840 size
*= sizeof(u64
);
5842 __output_copy(handle
, data
->callchain
, size
);
5845 perf_output_put(handle
, nr
);
5849 if (sample_type
& PERF_SAMPLE_RAW
) {
5850 struct perf_raw_record
*raw
= data
->raw
;
5853 struct perf_raw_frag
*frag
= &raw
->frag
;
5855 perf_output_put(handle
, raw
->size
);
5858 __output_custom(handle
, frag
->copy
,
5859 frag
->data
, frag
->size
);
5861 __output_copy(handle
, frag
->data
,
5864 if (perf_raw_frag_last(frag
))
5869 __output_skip(handle
, NULL
, frag
->pad
);
5875 .size
= sizeof(u32
),
5878 perf_output_put(handle
, raw
);
5882 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5883 if (data
->br_stack
) {
5886 size
= data
->br_stack
->nr
5887 * sizeof(struct perf_branch_entry
);
5889 perf_output_put(handle
, data
->br_stack
->nr
);
5890 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5893 * we always store at least the value of nr
5896 perf_output_put(handle
, nr
);
5900 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5901 u64 abi
= data
->regs_user
.abi
;
5904 * If there are no regs to dump, notice it through
5905 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5907 perf_output_put(handle
, abi
);
5910 u64 mask
= event
->attr
.sample_regs_user
;
5911 perf_output_sample_regs(handle
,
5912 data
->regs_user
.regs
,
5917 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5918 perf_output_sample_ustack(handle
,
5919 data
->stack_user_size
,
5920 data
->regs_user
.regs
);
5923 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5924 perf_output_put(handle
, data
->weight
);
5926 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5927 perf_output_put(handle
, data
->data_src
.val
);
5929 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5930 perf_output_put(handle
, data
->txn
);
5932 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5933 u64 abi
= data
->regs_intr
.abi
;
5935 * If there are no regs to dump, notice it through
5936 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5938 perf_output_put(handle
, abi
);
5941 u64 mask
= event
->attr
.sample_regs_intr
;
5943 perf_output_sample_regs(handle
,
5944 data
->regs_intr
.regs
,
5949 if (!event
->attr
.watermark
) {
5950 int wakeup_events
= event
->attr
.wakeup_events
;
5952 if (wakeup_events
) {
5953 struct ring_buffer
*rb
= handle
->rb
;
5954 int events
= local_inc_return(&rb
->events
);
5956 if (events
>= wakeup_events
) {
5957 local_sub(wakeup_events
, &rb
->events
);
5958 local_inc(&rb
->wakeup
);
5964 void perf_prepare_sample(struct perf_event_header
*header
,
5965 struct perf_sample_data
*data
,
5966 struct perf_event
*event
,
5967 struct pt_regs
*regs
)
5969 u64 sample_type
= event
->attr
.sample_type
;
5971 header
->type
= PERF_RECORD_SAMPLE
;
5972 header
->size
= sizeof(*header
) + event
->header_size
;
5975 header
->misc
|= perf_misc_flags(regs
);
5977 __perf_event_header__init_id(header
, data
, event
);
5979 if (sample_type
& PERF_SAMPLE_IP
)
5980 data
->ip
= perf_instruction_pointer(regs
);
5982 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5985 data
->callchain
= perf_callchain(event
, regs
);
5987 if (data
->callchain
)
5988 size
+= data
->callchain
->nr
;
5990 header
->size
+= size
* sizeof(u64
);
5993 if (sample_type
& PERF_SAMPLE_RAW
) {
5994 struct perf_raw_record
*raw
= data
->raw
;
5998 struct perf_raw_frag
*frag
= &raw
->frag
;
6003 if (perf_raw_frag_last(frag
))
6008 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6009 raw
->size
= size
- sizeof(u32
);
6010 frag
->pad
= raw
->size
- sum
;
6015 header
->size
+= size
;
6018 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6019 int size
= sizeof(u64
); /* nr */
6020 if (data
->br_stack
) {
6021 size
+= data
->br_stack
->nr
6022 * sizeof(struct perf_branch_entry
);
6024 header
->size
+= size
;
6027 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6028 perf_sample_regs_user(&data
->regs_user
, regs
,
6029 &data
->regs_user_copy
);
6031 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6032 /* regs dump ABI info */
6033 int size
= sizeof(u64
);
6035 if (data
->regs_user
.regs
) {
6036 u64 mask
= event
->attr
.sample_regs_user
;
6037 size
+= hweight64(mask
) * sizeof(u64
);
6040 header
->size
+= size
;
6043 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6045 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6046 * processed as the last one or have additional check added
6047 * in case new sample type is added, because we could eat
6048 * up the rest of the sample size.
6050 u16 stack_size
= event
->attr
.sample_stack_user
;
6051 u16 size
= sizeof(u64
);
6053 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6054 data
->regs_user
.regs
);
6057 * If there is something to dump, add space for the dump
6058 * itself and for the field that tells the dynamic size,
6059 * which is how many have been actually dumped.
6062 size
+= sizeof(u64
) + stack_size
;
6064 data
->stack_user_size
= stack_size
;
6065 header
->size
+= size
;
6068 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6069 /* regs dump ABI info */
6070 int size
= sizeof(u64
);
6072 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6074 if (data
->regs_intr
.regs
) {
6075 u64 mask
= event
->attr
.sample_regs_intr
;
6077 size
+= hweight64(mask
) * sizeof(u64
);
6080 header
->size
+= size
;
6084 static void __always_inline
6085 __perf_event_output(struct perf_event
*event
,
6086 struct perf_sample_data
*data
,
6087 struct pt_regs
*regs
,
6088 int (*output_begin
)(struct perf_output_handle
*,
6089 struct perf_event
*,
6092 struct perf_output_handle handle
;
6093 struct perf_event_header header
;
6095 /* protect the callchain buffers */
6098 perf_prepare_sample(&header
, data
, event
, regs
);
6100 if (output_begin(&handle
, event
, header
.size
))
6103 perf_output_sample(&handle
, &header
, data
, event
);
6105 perf_output_end(&handle
);
6112 perf_event_output_forward(struct perf_event
*event
,
6113 struct perf_sample_data
*data
,
6114 struct pt_regs
*regs
)
6116 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6120 perf_event_output_backward(struct perf_event
*event
,
6121 struct perf_sample_data
*data
,
6122 struct pt_regs
*regs
)
6124 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6128 perf_event_output(struct perf_event
*event
,
6129 struct perf_sample_data
*data
,
6130 struct pt_regs
*regs
)
6132 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6139 struct perf_read_event
{
6140 struct perf_event_header header
;
6147 perf_event_read_event(struct perf_event
*event
,
6148 struct task_struct
*task
)
6150 struct perf_output_handle handle
;
6151 struct perf_sample_data sample
;
6152 struct perf_read_event read_event
= {
6154 .type
= PERF_RECORD_READ
,
6156 .size
= sizeof(read_event
) + event
->read_size
,
6158 .pid
= perf_event_pid(event
, task
),
6159 .tid
= perf_event_tid(event
, task
),
6163 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6164 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6168 perf_output_put(&handle
, read_event
);
6169 perf_output_read(&handle
, event
);
6170 perf_event__output_id_sample(event
, &handle
, &sample
);
6172 perf_output_end(&handle
);
6175 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6178 perf_iterate_ctx(struct perf_event_context
*ctx
,
6179 perf_iterate_f output
,
6180 void *data
, bool all
)
6182 struct perf_event
*event
;
6184 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6186 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6188 if (!event_filter_match(event
))
6192 output(event
, data
);
6196 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6198 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6199 struct perf_event
*event
;
6201 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6203 * Skip events that are not fully formed yet; ensure that
6204 * if we observe event->ctx, both event and ctx will be
6205 * complete enough. See perf_install_in_context().
6207 if (!smp_load_acquire(&event
->ctx
))
6210 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6212 if (!event_filter_match(event
))
6214 output(event
, data
);
6219 * Iterate all events that need to receive side-band events.
6221 * For new callers; ensure that account_pmu_sb_event() includes
6222 * your event, otherwise it might not get delivered.
6225 perf_iterate_sb(perf_iterate_f output
, void *data
,
6226 struct perf_event_context
*task_ctx
)
6228 struct perf_event_context
*ctx
;
6235 * If we have task_ctx != NULL we only notify the task context itself.
6236 * The task_ctx is set only for EXIT events before releasing task
6240 perf_iterate_ctx(task_ctx
, output
, data
, false);
6244 perf_iterate_sb_cpu(output
, data
);
6246 for_each_task_context_nr(ctxn
) {
6247 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6249 perf_iterate_ctx(ctx
, output
, data
, false);
6257 * Clear all file-based filters at exec, they'll have to be
6258 * re-instated when/if these objects are mmapped again.
6260 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6262 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6263 struct perf_addr_filter
*filter
;
6264 unsigned int restart
= 0, count
= 0;
6265 unsigned long flags
;
6267 if (!has_addr_filter(event
))
6270 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6271 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6272 if (filter
->inode
) {
6273 event
->addr_filters_offs
[count
] = 0;
6281 event
->addr_filters_gen
++;
6282 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6285 perf_event_stop(event
, 1);
6288 void perf_event_exec(void)
6290 struct perf_event_context
*ctx
;
6294 for_each_task_context_nr(ctxn
) {
6295 ctx
= current
->perf_event_ctxp
[ctxn
];
6299 perf_event_enable_on_exec(ctxn
);
6301 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6307 struct remote_output
{
6308 struct ring_buffer
*rb
;
6312 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6314 struct perf_event
*parent
= event
->parent
;
6315 struct remote_output
*ro
= data
;
6316 struct ring_buffer
*rb
= ro
->rb
;
6317 struct stop_event_data sd
= {
6321 if (!has_aux(event
))
6328 * In case of inheritance, it will be the parent that links to the
6329 * ring-buffer, but it will be the child that's actually using it.
6331 * We are using event::rb to determine if the event should be stopped,
6332 * however this may race with ring_buffer_attach() (through set_output),
6333 * which will make us skip the event that actually needs to be stopped.
6334 * So ring_buffer_attach() has to stop an aux event before re-assigning
6337 if (rcu_dereference(parent
->rb
) == rb
)
6338 ro
->err
= __perf_event_stop(&sd
);
6341 static int __perf_pmu_output_stop(void *info
)
6343 struct perf_event
*event
= info
;
6344 struct pmu
*pmu
= event
->pmu
;
6345 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6346 struct remote_output ro
= {
6351 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6352 if (cpuctx
->task_ctx
)
6353 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6360 static void perf_pmu_output_stop(struct perf_event
*event
)
6362 struct perf_event
*iter
;
6367 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6369 * For per-CPU events, we need to make sure that neither they
6370 * nor their children are running; for cpu==-1 events it's
6371 * sufficient to stop the event itself if it's active, since
6372 * it can't have children.
6376 cpu
= READ_ONCE(iter
->oncpu
);
6381 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6382 if (err
== -EAGAIN
) {
6391 * task tracking -- fork/exit
6393 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6396 struct perf_task_event
{
6397 struct task_struct
*task
;
6398 struct perf_event_context
*task_ctx
;
6401 struct perf_event_header header
;
6411 static int perf_event_task_match(struct perf_event
*event
)
6413 return event
->attr
.comm
|| event
->attr
.mmap
||
6414 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6418 static void perf_event_task_output(struct perf_event
*event
,
6421 struct perf_task_event
*task_event
= data
;
6422 struct perf_output_handle handle
;
6423 struct perf_sample_data sample
;
6424 struct task_struct
*task
= task_event
->task
;
6425 int ret
, size
= task_event
->event_id
.header
.size
;
6427 if (!perf_event_task_match(event
))
6430 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6432 ret
= perf_output_begin(&handle
, event
,
6433 task_event
->event_id
.header
.size
);
6437 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6438 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6440 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6441 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6443 task_event
->event_id
.time
= perf_event_clock(event
);
6445 perf_output_put(&handle
, task_event
->event_id
);
6447 perf_event__output_id_sample(event
, &handle
, &sample
);
6449 perf_output_end(&handle
);
6451 task_event
->event_id
.header
.size
= size
;
6454 static void perf_event_task(struct task_struct
*task
,
6455 struct perf_event_context
*task_ctx
,
6458 struct perf_task_event task_event
;
6460 if (!atomic_read(&nr_comm_events
) &&
6461 !atomic_read(&nr_mmap_events
) &&
6462 !atomic_read(&nr_task_events
))
6465 task_event
= (struct perf_task_event
){
6467 .task_ctx
= task_ctx
,
6470 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6472 .size
= sizeof(task_event
.event_id
),
6482 perf_iterate_sb(perf_event_task_output
,
6487 void perf_event_fork(struct task_struct
*task
)
6489 perf_event_task(task
, NULL
, 1);
6496 struct perf_comm_event
{
6497 struct task_struct
*task
;
6502 struct perf_event_header header
;
6509 static int perf_event_comm_match(struct perf_event
*event
)
6511 return event
->attr
.comm
;
6514 static void perf_event_comm_output(struct perf_event
*event
,
6517 struct perf_comm_event
*comm_event
= data
;
6518 struct perf_output_handle handle
;
6519 struct perf_sample_data sample
;
6520 int size
= comm_event
->event_id
.header
.size
;
6523 if (!perf_event_comm_match(event
))
6526 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6527 ret
= perf_output_begin(&handle
, event
,
6528 comm_event
->event_id
.header
.size
);
6533 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6534 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6536 perf_output_put(&handle
, comm_event
->event_id
);
6537 __output_copy(&handle
, comm_event
->comm
,
6538 comm_event
->comm_size
);
6540 perf_event__output_id_sample(event
, &handle
, &sample
);
6542 perf_output_end(&handle
);
6544 comm_event
->event_id
.header
.size
= size
;
6547 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6549 char comm
[TASK_COMM_LEN
];
6552 memset(comm
, 0, sizeof(comm
));
6553 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6554 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6556 comm_event
->comm
= comm
;
6557 comm_event
->comm_size
= size
;
6559 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6561 perf_iterate_sb(perf_event_comm_output
,
6566 void perf_event_comm(struct task_struct
*task
, bool exec
)
6568 struct perf_comm_event comm_event
;
6570 if (!atomic_read(&nr_comm_events
))
6573 comm_event
= (struct perf_comm_event
){
6579 .type
= PERF_RECORD_COMM
,
6580 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6588 perf_event_comm_event(&comm_event
);
6595 struct perf_mmap_event
{
6596 struct vm_area_struct
*vma
;
6598 const char *file_name
;
6606 struct perf_event_header header
;
6616 static int perf_event_mmap_match(struct perf_event
*event
,
6619 struct perf_mmap_event
*mmap_event
= data
;
6620 struct vm_area_struct
*vma
= mmap_event
->vma
;
6621 int executable
= vma
->vm_flags
& VM_EXEC
;
6623 return (!executable
&& event
->attr
.mmap_data
) ||
6624 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6627 static void perf_event_mmap_output(struct perf_event
*event
,
6630 struct perf_mmap_event
*mmap_event
= data
;
6631 struct perf_output_handle handle
;
6632 struct perf_sample_data sample
;
6633 int size
= mmap_event
->event_id
.header
.size
;
6636 if (!perf_event_mmap_match(event
, data
))
6639 if (event
->attr
.mmap2
) {
6640 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6641 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6642 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6643 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6644 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6645 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6646 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6649 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6650 ret
= perf_output_begin(&handle
, event
,
6651 mmap_event
->event_id
.header
.size
);
6655 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6656 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6658 perf_output_put(&handle
, mmap_event
->event_id
);
6660 if (event
->attr
.mmap2
) {
6661 perf_output_put(&handle
, mmap_event
->maj
);
6662 perf_output_put(&handle
, mmap_event
->min
);
6663 perf_output_put(&handle
, mmap_event
->ino
);
6664 perf_output_put(&handle
, mmap_event
->ino_generation
);
6665 perf_output_put(&handle
, mmap_event
->prot
);
6666 perf_output_put(&handle
, mmap_event
->flags
);
6669 __output_copy(&handle
, mmap_event
->file_name
,
6670 mmap_event
->file_size
);
6672 perf_event__output_id_sample(event
, &handle
, &sample
);
6674 perf_output_end(&handle
);
6676 mmap_event
->event_id
.header
.size
= size
;
6679 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6681 struct vm_area_struct
*vma
= mmap_event
->vma
;
6682 struct file
*file
= vma
->vm_file
;
6683 int maj
= 0, min
= 0;
6684 u64 ino
= 0, gen
= 0;
6685 u32 prot
= 0, flags
= 0;
6691 if (vma
->vm_flags
& VM_READ
)
6693 if (vma
->vm_flags
& VM_WRITE
)
6695 if (vma
->vm_flags
& VM_EXEC
)
6698 if (vma
->vm_flags
& VM_MAYSHARE
)
6701 flags
= MAP_PRIVATE
;
6703 if (vma
->vm_flags
& VM_DENYWRITE
)
6704 flags
|= MAP_DENYWRITE
;
6705 if (vma
->vm_flags
& VM_MAYEXEC
)
6706 flags
|= MAP_EXECUTABLE
;
6707 if (vma
->vm_flags
& VM_LOCKED
)
6708 flags
|= MAP_LOCKED
;
6709 if (vma
->vm_flags
& VM_HUGETLB
)
6710 flags
|= MAP_HUGETLB
;
6713 struct inode
*inode
;
6716 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6722 * d_path() works from the end of the rb backwards, so we
6723 * need to add enough zero bytes after the string to handle
6724 * the 64bit alignment we do later.
6726 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6731 inode
= file_inode(vma
->vm_file
);
6732 dev
= inode
->i_sb
->s_dev
;
6734 gen
= inode
->i_generation
;
6740 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6741 name
= (char *) vma
->vm_ops
->name(vma
);
6746 name
= (char *)arch_vma_name(vma
);
6750 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6751 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6755 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6756 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6766 strlcpy(tmp
, name
, sizeof(tmp
));
6770 * Since our buffer works in 8 byte units we need to align our string
6771 * size to a multiple of 8. However, we must guarantee the tail end is
6772 * zero'd out to avoid leaking random bits to userspace.
6774 size
= strlen(name
)+1;
6775 while (!IS_ALIGNED(size
, sizeof(u64
)))
6776 name
[size
++] = '\0';
6778 mmap_event
->file_name
= name
;
6779 mmap_event
->file_size
= size
;
6780 mmap_event
->maj
= maj
;
6781 mmap_event
->min
= min
;
6782 mmap_event
->ino
= ino
;
6783 mmap_event
->ino_generation
= gen
;
6784 mmap_event
->prot
= prot
;
6785 mmap_event
->flags
= flags
;
6787 if (!(vma
->vm_flags
& VM_EXEC
))
6788 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6790 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6792 perf_iterate_sb(perf_event_mmap_output
,
6800 * Check whether inode and address range match filter criteria.
6802 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
6803 struct file
*file
, unsigned long offset
,
6806 if (filter
->inode
!= file_inode(file
))
6809 if (filter
->offset
> offset
+ size
)
6812 if (filter
->offset
+ filter
->size
< offset
)
6818 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
6820 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6821 struct vm_area_struct
*vma
= data
;
6822 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
6823 struct file
*file
= vma
->vm_file
;
6824 struct perf_addr_filter
*filter
;
6825 unsigned int restart
= 0, count
= 0;
6827 if (!has_addr_filter(event
))
6833 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6834 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6835 if (perf_addr_filter_match(filter
, file
, off
,
6836 vma
->vm_end
- vma
->vm_start
)) {
6837 event
->addr_filters_offs
[count
] = vma
->vm_start
;
6845 event
->addr_filters_gen
++;
6846 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6849 perf_event_stop(event
, 1);
6853 * Adjust all task's events' filters to the new vma
6855 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
6857 struct perf_event_context
*ctx
;
6861 * Data tracing isn't supported yet and as such there is no need
6862 * to keep track of anything that isn't related to executable code:
6864 if (!(vma
->vm_flags
& VM_EXEC
))
6868 for_each_task_context_nr(ctxn
) {
6869 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6873 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
6878 void perf_event_mmap(struct vm_area_struct
*vma
)
6880 struct perf_mmap_event mmap_event
;
6882 if (!atomic_read(&nr_mmap_events
))
6885 mmap_event
= (struct perf_mmap_event
){
6891 .type
= PERF_RECORD_MMAP
,
6892 .misc
= PERF_RECORD_MISC_USER
,
6897 .start
= vma
->vm_start
,
6898 .len
= vma
->vm_end
- vma
->vm_start
,
6899 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6901 /* .maj (attr_mmap2 only) */
6902 /* .min (attr_mmap2 only) */
6903 /* .ino (attr_mmap2 only) */
6904 /* .ino_generation (attr_mmap2 only) */
6905 /* .prot (attr_mmap2 only) */
6906 /* .flags (attr_mmap2 only) */
6909 perf_addr_filters_adjust(vma
);
6910 perf_event_mmap_event(&mmap_event
);
6913 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6914 unsigned long size
, u64 flags
)
6916 struct perf_output_handle handle
;
6917 struct perf_sample_data sample
;
6918 struct perf_aux_event
{
6919 struct perf_event_header header
;
6925 .type
= PERF_RECORD_AUX
,
6927 .size
= sizeof(rec
),
6935 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6936 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6941 perf_output_put(&handle
, rec
);
6942 perf_event__output_id_sample(event
, &handle
, &sample
);
6944 perf_output_end(&handle
);
6948 * Lost/dropped samples logging
6950 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6952 struct perf_output_handle handle
;
6953 struct perf_sample_data sample
;
6957 struct perf_event_header header
;
6959 } lost_samples_event
= {
6961 .type
= PERF_RECORD_LOST_SAMPLES
,
6963 .size
= sizeof(lost_samples_event
),
6968 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6970 ret
= perf_output_begin(&handle
, event
,
6971 lost_samples_event
.header
.size
);
6975 perf_output_put(&handle
, lost_samples_event
);
6976 perf_event__output_id_sample(event
, &handle
, &sample
);
6977 perf_output_end(&handle
);
6981 * context_switch tracking
6984 struct perf_switch_event
{
6985 struct task_struct
*task
;
6986 struct task_struct
*next_prev
;
6989 struct perf_event_header header
;
6995 static int perf_event_switch_match(struct perf_event
*event
)
6997 return event
->attr
.context_switch
;
7000 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7002 struct perf_switch_event
*se
= data
;
7003 struct perf_output_handle handle
;
7004 struct perf_sample_data sample
;
7007 if (!perf_event_switch_match(event
))
7010 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7011 if (event
->ctx
->task
) {
7012 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7013 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7015 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7016 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7017 se
->event_id
.next_prev_pid
=
7018 perf_event_pid(event
, se
->next_prev
);
7019 se
->event_id
.next_prev_tid
=
7020 perf_event_tid(event
, se
->next_prev
);
7023 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7025 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7029 if (event
->ctx
->task
)
7030 perf_output_put(&handle
, se
->event_id
.header
);
7032 perf_output_put(&handle
, se
->event_id
);
7034 perf_event__output_id_sample(event
, &handle
, &sample
);
7036 perf_output_end(&handle
);
7039 static void perf_event_switch(struct task_struct
*task
,
7040 struct task_struct
*next_prev
, bool sched_in
)
7042 struct perf_switch_event switch_event
;
7044 /* N.B. caller checks nr_switch_events != 0 */
7046 switch_event
= (struct perf_switch_event
){
7048 .next_prev
= next_prev
,
7052 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7055 /* .next_prev_pid */
7056 /* .next_prev_tid */
7060 perf_iterate_sb(perf_event_switch_output
,
7066 * IRQ throttle logging
7069 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7071 struct perf_output_handle handle
;
7072 struct perf_sample_data sample
;
7076 struct perf_event_header header
;
7080 } throttle_event
= {
7082 .type
= PERF_RECORD_THROTTLE
,
7084 .size
= sizeof(throttle_event
),
7086 .time
= perf_event_clock(event
),
7087 .id
= primary_event_id(event
),
7088 .stream_id
= event
->id
,
7092 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7094 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7096 ret
= perf_output_begin(&handle
, event
,
7097 throttle_event
.header
.size
);
7101 perf_output_put(&handle
, throttle_event
);
7102 perf_event__output_id_sample(event
, &handle
, &sample
);
7103 perf_output_end(&handle
);
7106 static void perf_log_itrace_start(struct perf_event
*event
)
7108 struct perf_output_handle handle
;
7109 struct perf_sample_data sample
;
7110 struct perf_aux_event
{
7111 struct perf_event_header header
;
7118 event
= event
->parent
;
7120 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7121 event
->hw
.itrace_started
)
7124 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7125 rec
.header
.misc
= 0;
7126 rec
.header
.size
= sizeof(rec
);
7127 rec
.pid
= perf_event_pid(event
, current
);
7128 rec
.tid
= perf_event_tid(event
, current
);
7130 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7131 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7136 perf_output_put(&handle
, rec
);
7137 perf_event__output_id_sample(event
, &handle
, &sample
);
7139 perf_output_end(&handle
);
7143 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7145 struct hw_perf_event
*hwc
= &event
->hw
;
7149 seq
= __this_cpu_read(perf_throttled_seq
);
7150 if (seq
!= hwc
->interrupts_seq
) {
7151 hwc
->interrupts_seq
= seq
;
7152 hwc
->interrupts
= 1;
7155 if (unlikely(throttle
7156 && hwc
->interrupts
>= max_samples_per_tick
)) {
7157 __this_cpu_inc(perf_throttled_count
);
7158 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7159 hwc
->interrupts
= MAX_INTERRUPTS
;
7160 perf_log_throttle(event
, 0);
7165 if (event
->attr
.freq
) {
7166 u64 now
= perf_clock();
7167 s64 delta
= now
- hwc
->freq_time_stamp
;
7169 hwc
->freq_time_stamp
= now
;
7171 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7172 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7178 int perf_event_account_interrupt(struct perf_event
*event
)
7180 return __perf_event_account_interrupt(event
, 1);
7184 * Generic event overflow handling, sampling.
7187 static int __perf_event_overflow(struct perf_event
*event
,
7188 int throttle
, struct perf_sample_data
*data
,
7189 struct pt_regs
*regs
)
7191 int events
= atomic_read(&event
->event_limit
);
7195 * Non-sampling counters might still use the PMI to fold short
7196 * hardware counters, ignore those.
7198 if (unlikely(!is_sampling_event(event
)))
7201 ret
= __perf_event_account_interrupt(event
, throttle
);
7204 * XXX event_limit might not quite work as expected on inherited
7208 event
->pending_kill
= POLL_IN
;
7209 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7211 event
->pending_kill
= POLL_HUP
;
7213 perf_event_disable_inatomic(event
);
7216 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7218 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7219 event
->pending_wakeup
= 1;
7220 irq_work_queue(&event
->pending
);
7226 int perf_event_overflow(struct perf_event
*event
,
7227 struct perf_sample_data
*data
,
7228 struct pt_regs
*regs
)
7230 return __perf_event_overflow(event
, 1, data
, regs
);
7234 * Generic software event infrastructure
7237 struct swevent_htable
{
7238 struct swevent_hlist
*swevent_hlist
;
7239 struct mutex hlist_mutex
;
7242 /* Recursion avoidance in each contexts */
7243 int recursion
[PERF_NR_CONTEXTS
];
7246 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7249 * We directly increment event->count and keep a second value in
7250 * event->hw.period_left to count intervals. This period event
7251 * is kept in the range [-sample_period, 0] so that we can use the
7255 u64
perf_swevent_set_period(struct perf_event
*event
)
7257 struct hw_perf_event
*hwc
= &event
->hw
;
7258 u64 period
= hwc
->last_period
;
7262 hwc
->last_period
= hwc
->sample_period
;
7265 old
= val
= local64_read(&hwc
->period_left
);
7269 nr
= div64_u64(period
+ val
, period
);
7270 offset
= nr
* period
;
7272 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7278 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7279 struct perf_sample_data
*data
,
7280 struct pt_regs
*regs
)
7282 struct hw_perf_event
*hwc
= &event
->hw
;
7286 overflow
= perf_swevent_set_period(event
);
7288 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7291 for (; overflow
; overflow
--) {
7292 if (__perf_event_overflow(event
, throttle
,
7295 * We inhibit the overflow from happening when
7296 * hwc->interrupts == MAX_INTERRUPTS.
7304 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7305 struct perf_sample_data
*data
,
7306 struct pt_regs
*regs
)
7308 struct hw_perf_event
*hwc
= &event
->hw
;
7310 local64_add(nr
, &event
->count
);
7315 if (!is_sampling_event(event
))
7318 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7320 return perf_swevent_overflow(event
, 1, data
, regs
);
7322 data
->period
= event
->hw
.last_period
;
7324 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7325 return perf_swevent_overflow(event
, 1, data
, regs
);
7327 if (local64_add_negative(nr
, &hwc
->period_left
))
7330 perf_swevent_overflow(event
, 0, data
, regs
);
7333 static int perf_exclude_event(struct perf_event
*event
,
7334 struct pt_regs
*regs
)
7336 if (event
->hw
.state
& PERF_HES_STOPPED
)
7340 if (event
->attr
.exclude_user
&& user_mode(regs
))
7343 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7350 static int perf_swevent_match(struct perf_event
*event
,
7351 enum perf_type_id type
,
7353 struct perf_sample_data
*data
,
7354 struct pt_regs
*regs
)
7356 if (event
->attr
.type
!= type
)
7359 if (event
->attr
.config
!= event_id
)
7362 if (perf_exclude_event(event
, regs
))
7368 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7370 u64 val
= event_id
| (type
<< 32);
7372 return hash_64(val
, SWEVENT_HLIST_BITS
);
7375 static inline struct hlist_head
*
7376 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7378 u64 hash
= swevent_hash(type
, event_id
);
7380 return &hlist
->heads
[hash
];
7383 /* For the read side: events when they trigger */
7384 static inline struct hlist_head
*
7385 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7387 struct swevent_hlist
*hlist
;
7389 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7393 return __find_swevent_head(hlist
, type
, event_id
);
7396 /* For the event head insertion and removal in the hlist */
7397 static inline struct hlist_head
*
7398 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7400 struct swevent_hlist
*hlist
;
7401 u32 event_id
= event
->attr
.config
;
7402 u64 type
= event
->attr
.type
;
7405 * Event scheduling is always serialized against hlist allocation
7406 * and release. Which makes the protected version suitable here.
7407 * The context lock guarantees that.
7409 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7410 lockdep_is_held(&event
->ctx
->lock
));
7414 return __find_swevent_head(hlist
, type
, event_id
);
7417 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7419 struct perf_sample_data
*data
,
7420 struct pt_regs
*regs
)
7422 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7423 struct perf_event
*event
;
7424 struct hlist_head
*head
;
7427 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7431 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7432 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7433 perf_swevent_event(event
, nr
, data
, regs
);
7439 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7441 int perf_swevent_get_recursion_context(void)
7443 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7445 return get_recursion_context(swhash
->recursion
);
7447 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7449 void perf_swevent_put_recursion_context(int rctx
)
7451 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7453 put_recursion_context(swhash
->recursion
, rctx
);
7456 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7458 struct perf_sample_data data
;
7460 if (WARN_ON_ONCE(!regs
))
7463 perf_sample_data_init(&data
, addr
, 0);
7464 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7467 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7471 preempt_disable_notrace();
7472 rctx
= perf_swevent_get_recursion_context();
7473 if (unlikely(rctx
< 0))
7476 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7478 perf_swevent_put_recursion_context(rctx
);
7480 preempt_enable_notrace();
7483 static void perf_swevent_read(struct perf_event
*event
)
7487 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7489 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7490 struct hw_perf_event
*hwc
= &event
->hw
;
7491 struct hlist_head
*head
;
7493 if (is_sampling_event(event
)) {
7494 hwc
->last_period
= hwc
->sample_period
;
7495 perf_swevent_set_period(event
);
7498 hwc
->state
= !(flags
& PERF_EF_START
);
7500 head
= find_swevent_head(swhash
, event
);
7501 if (WARN_ON_ONCE(!head
))
7504 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7505 perf_event_update_userpage(event
);
7510 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7512 hlist_del_rcu(&event
->hlist_entry
);
7515 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7517 event
->hw
.state
= 0;
7520 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7522 event
->hw
.state
= PERF_HES_STOPPED
;
7525 /* Deref the hlist from the update side */
7526 static inline struct swevent_hlist
*
7527 swevent_hlist_deref(struct swevent_htable
*swhash
)
7529 return rcu_dereference_protected(swhash
->swevent_hlist
,
7530 lockdep_is_held(&swhash
->hlist_mutex
));
7533 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7535 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7540 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7541 kfree_rcu(hlist
, rcu_head
);
7544 static void swevent_hlist_put_cpu(int cpu
)
7546 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7548 mutex_lock(&swhash
->hlist_mutex
);
7550 if (!--swhash
->hlist_refcount
)
7551 swevent_hlist_release(swhash
);
7553 mutex_unlock(&swhash
->hlist_mutex
);
7556 static void swevent_hlist_put(void)
7560 for_each_possible_cpu(cpu
)
7561 swevent_hlist_put_cpu(cpu
);
7564 static int swevent_hlist_get_cpu(int cpu
)
7566 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7569 mutex_lock(&swhash
->hlist_mutex
);
7570 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
7571 struct swevent_hlist
*hlist
;
7573 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7578 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7580 swhash
->hlist_refcount
++;
7582 mutex_unlock(&swhash
->hlist_mutex
);
7587 static int swevent_hlist_get(void)
7589 int err
, cpu
, failed_cpu
;
7592 for_each_possible_cpu(cpu
) {
7593 err
= swevent_hlist_get_cpu(cpu
);
7603 for_each_possible_cpu(cpu
) {
7604 if (cpu
== failed_cpu
)
7606 swevent_hlist_put_cpu(cpu
);
7613 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7615 static void sw_perf_event_destroy(struct perf_event
*event
)
7617 u64 event_id
= event
->attr
.config
;
7619 WARN_ON(event
->parent
);
7621 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7622 swevent_hlist_put();
7625 static int perf_swevent_init(struct perf_event
*event
)
7627 u64 event_id
= event
->attr
.config
;
7629 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7633 * no branch sampling for software events
7635 if (has_branch_stack(event
))
7639 case PERF_COUNT_SW_CPU_CLOCK
:
7640 case PERF_COUNT_SW_TASK_CLOCK
:
7647 if (event_id
>= PERF_COUNT_SW_MAX
)
7650 if (!event
->parent
) {
7653 err
= swevent_hlist_get();
7657 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7658 event
->destroy
= sw_perf_event_destroy
;
7664 static struct pmu perf_swevent
= {
7665 .task_ctx_nr
= perf_sw_context
,
7667 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7669 .event_init
= perf_swevent_init
,
7670 .add
= perf_swevent_add
,
7671 .del
= perf_swevent_del
,
7672 .start
= perf_swevent_start
,
7673 .stop
= perf_swevent_stop
,
7674 .read
= perf_swevent_read
,
7677 #ifdef CONFIG_EVENT_TRACING
7679 static int perf_tp_filter_match(struct perf_event
*event
,
7680 struct perf_sample_data
*data
)
7682 void *record
= data
->raw
->frag
.data
;
7684 /* only top level events have filters set */
7686 event
= event
->parent
;
7688 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7693 static int perf_tp_event_match(struct perf_event
*event
,
7694 struct perf_sample_data
*data
,
7695 struct pt_regs
*regs
)
7697 if (event
->hw
.state
& PERF_HES_STOPPED
)
7700 * All tracepoints are from kernel-space.
7702 if (event
->attr
.exclude_kernel
)
7705 if (!perf_tp_filter_match(event
, data
))
7711 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7712 struct trace_event_call
*call
, u64 count
,
7713 struct pt_regs
*regs
, struct hlist_head
*head
,
7714 struct task_struct
*task
)
7716 struct bpf_prog
*prog
= call
->prog
;
7719 *(struct pt_regs
**)raw_data
= regs
;
7720 if (!trace_call_bpf(prog
, raw_data
) || hlist_empty(head
)) {
7721 perf_swevent_put_recursion_context(rctx
);
7725 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7728 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7730 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7731 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7732 struct task_struct
*task
)
7734 struct perf_sample_data data
;
7735 struct perf_event
*event
;
7737 struct perf_raw_record raw
= {
7744 perf_sample_data_init(&data
, 0, 0);
7747 perf_trace_buf_update(record
, event_type
);
7749 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7750 if (perf_tp_event_match(event
, &data
, regs
))
7751 perf_swevent_event(event
, count
, &data
, regs
);
7755 * If we got specified a target task, also iterate its context and
7756 * deliver this event there too.
7758 if (task
&& task
!= current
) {
7759 struct perf_event_context
*ctx
;
7760 struct trace_entry
*entry
= record
;
7763 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7767 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7768 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7770 if (event
->attr
.config
!= entry
->type
)
7772 if (perf_tp_event_match(event
, &data
, regs
))
7773 perf_swevent_event(event
, count
, &data
, regs
);
7779 perf_swevent_put_recursion_context(rctx
);
7781 EXPORT_SYMBOL_GPL(perf_tp_event
);
7783 static void tp_perf_event_destroy(struct perf_event
*event
)
7785 perf_trace_destroy(event
);
7788 static int perf_tp_event_init(struct perf_event
*event
)
7792 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7796 * no branch sampling for tracepoint events
7798 if (has_branch_stack(event
))
7801 err
= perf_trace_init(event
);
7805 event
->destroy
= tp_perf_event_destroy
;
7810 static struct pmu perf_tracepoint
= {
7811 .task_ctx_nr
= perf_sw_context
,
7813 .event_init
= perf_tp_event_init
,
7814 .add
= perf_trace_add
,
7815 .del
= perf_trace_del
,
7816 .start
= perf_swevent_start
,
7817 .stop
= perf_swevent_stop
,
7818 .read
= perf_swevent_read
,
7821 static inline void perf_tp_register(void)
7823 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7826 static void perf_event_free_filter(struct perf_event
*event
)
7828 ftrace_profile_free_filter(event
);
7831 #ifdef CONFIG_BPF_SYSCALL
7832 static void bpf_overflow_handler(struct perf_event
*event
,
7833 struct perf_sample_data
*data
,
7834 struct pt_regs
*regs
)
7836 struct bpf_perf_event_data_kern ctx
= {
7843 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
7846 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
7849 __this_cpu_dec(bpf_prog_active
);
7854 event
->orig_overflow_handler(event
, data
, regs
);
7857 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
7859 struct bpf_prog
*prog
;
7861 if (event
->overflow_handler_context
)
7862 /* hw breakpoint or kernel counter */
7868 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
7870 return PTR_ERR(prog
);
7873 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
7874 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
7878 static void perf_event_free_bpf_handler(struct perf_event
*event
)
7880 struct bpf_prog
*prog
= event
->prog
;
7885 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
7890 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
7894 static void perf_event_free_bpf_handler(struct perf_event
*event
)
7899 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7901 bool is_kprobe
, is_tracepoint
;
7902 struct bpf_prog
*prog
;
7904 if (event
->attr
.type
== PERF_TYPE_HARDWARE
||
7905 event
->attr
.type
== PERF_TYPE_SOFTWARE
)
7906 return perf_event_set_bpf_handler(event
, prog_fd
);
7908 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7911 if (event
->tp_event
->prog
)
7914 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
7915 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
7916 if (!is_kprobe
&& !is_tracepoint
)
7917 /* bpf programs can only be attached to u/kprobe or tracepoint */
7920 prog
= bpf_prog_get(prog_fd
);
7922 return PTR_ERR(prog
);
7924 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
7925 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
7926 /* valid fd, but invalid bpf program type */
7931 if (is_tracepoint
) {
7932 int off
= trace_event_get_offsets(event
->tp_event
);
7934 if (prog
->aux
->max_ctx_offset
> off
) {
7939 event
->tp_event
->prog
= prog
;
7944 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7946 struct bpf_prog
*prog
;
7948 perf_event_free_bpf_handler(event
);
7950 if (!event
->tp_event
)
7953 prog
= event
->tp_event
->prog
;
7955 event
->tp_event
->prog
= NULL
;
7962 static inline void perf_tp_register(void)
7966 static void perf_event_free_filter(struct perf_event
*event
)
7970 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7975 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7978 #endif /* CONFIG_EVENT_TRACING */
7980 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7981 void perf_bp_event(struct perf_event
*bp
, void *data
)
7983 struct perf_sample_data sample
;
7984 struct pt_regs
*regs
= data
;
7986 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7988 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7989 perf_swevent_event(bp
, 1, &sample
, regs
);
7994 * Allocate a new address filter
7996 static struct perf_addr_filter
*
7997 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
7999 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8000 struct perf_addr_filter
*filter
;
8002 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8006 INIT_LIST_HEAD(&filter
->entry
);
8007 list_add_tail(&filter
->entry
, filters
);
8012 static void free_filters_list(struct list_head
*filters
)
8014 struct perf_addr_filter
*filter
, *iter
;
8016 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8018 iput(filter
->inode
);
8019 list_del(&filter
->entry
);
8025 * Free existing address filters and optionally install new ones
8027 static void perf_addr_filters_splice(struct perf_event
*event
,
8028 struct list_head
*head
)
8030 unsigned long flags
;
8033 if (!has_addr_filter(event
))
8036 /* don't bother with children, they don't have their own filters */
8040 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8042 list_splice_init(&event
->addr_filters
.list
, &list
);
8044 list_splice(head
, &event
->addr_filters
.list
);
8046 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8048 free_filters_list(&list
);
8052 * Scan through mm's vmas and see if one of them matches the
8053 * @filter; if so, adjust filter's address range.
8054 * Called with mm::mmap_sem down for reading.
8056 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8057 struct mm_struct
*mm
)
8059 struct vm_area_struct
*vma
;
8061 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8062 struct file
*file
= vma
->vm_file
;
8063 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8064 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8069 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8072 return vma
->vm_start
;
8079 * Update event's address range filters based on the
8080 * task's existing mappings, if any.
8082 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8084 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8085 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8086 struct perf_addr_filter
*filter
;
8087 struct mm_struct
*mm
= NULL
;
8088 unsigned int count
= 0;
8089 unsigned long flags
;
8092 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8093 * will stop on the parent's child_mutex that our caller is also holding
8095 if (task
== TASK_TOMBSTONE
)
8098 if (!ifh
->nr_file_filters
)
8101 mm
= get_task_mm(event
->ctx
->task
);
8105 down_read(&mm
->mmap_sem
);
8107 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8108 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8109 event
->addr_filters_offs
[count
] = 0;
8112 * Adjust base offset if the filter is associated to a binary
8113 * that needs to be mapped:
8116 event
->addr_filters_offs
[count
] =
8117 perf_addr_filter_apply(filter
, mm
);
8122 event
->addr_filters_gen
++;
8123 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8125 up_read(&mm
->mmap_sem
);
8130 perf_event_stop(event
, 1);
8134 * Address range filtering: limiting the data to certain
8135 * instruction address ranges. Filters are ioctl()ed to us from
8136 * userspace as ascii strings.
8138 * Filter string format:
8141 * where ACTION is one of the
8142 * * "filter": limit the trace to this region
8143 * * "start": start tracing from this address
8144 * * "stop": stop tracing at this address/region;
8146 * * for kernel addresses: <start address>[/<size>]
8147 * * for object files: <start address>[/<size>]@</path/to/object/file>
8149 * if <size> is not specified, the range is treated as a single address.
8163 IF_STATE_ACTION
= 0,
8168 static const match_table_t if_tokens
= {
8169 { IF_ACT_FILTER
, "filter" },
8170 { IF_ACT_START
, "start" },
8171 { IF_ACT_STOP
, "stop" },
8172 { IF_SRC_FILE
, "%u/%u@%s" },
8173 { IF_SRC_KERNEL
, "%u/%u" },
8174 { IF_SRC_FILEADDR
, "%u@%s" },
8175 { IF_SRC_KERNELADDR
, "%u" },
8176 { IF_ACT_NONE
, NULL
},
8180 * Address filter string parser
8183 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8184 struct list_head
*filters
)
8186 struct perf_addr_filter
*filter
= NULL
;
8187 char *start
, *orig
, *filename
= NULL
;
8189 substring_t args
[MAX_OPT_ARGS
];
8190 int state
= IF_STATE_ACTION
, token
;
8191 unsigned int kernel
= 0;
8194 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8198 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8204 /* filter definition begins */
8205 if (state
== IF_STATE_ACTION
) {
8206 filter
= perf_addr_filter_new(event
, filters
);
8211 token
= match_token(start
, if_tokens
, args
);
8218 if (state
!= IF_STATE_ACTION
)
8221 state
= IF_STATE_SOURCE
;
8224 case IF_SRC_KERNELADDR
:
8228 case IF_SRC_FILEADDR
:
8230 if (state
!= IF_STATE_SOURCE
)
8233 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8237 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8241 if (filter
->range
) {
8243 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8248 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8249 int fpos
= filter
->range
? 2 : 1;
8251 filename
= match_strdup(&args
[fpos
]);
8258 state
= IF_STATE_END
;
8266 * Filter definition is fully parsed, validate and install it.
8267 * Make sure that it doesn't contradict itself or the event's
8270 if (state
== IF_STATE_END
) {
8272 if (kernel
&& event
->attr
.exclude_kernel
)
8280 * For now, we only support file-based filters
8281 * in per-task events; doing so for CPU-wide
8282 * events requires additional context switching
8283 * trickery, since same object code will be
8284 * mapped at different virtual addresses in
8285 * different processes.
8288 if (!event
->ctx
->task
)
8289 goto fail_free_name
;
8291 /* look up the path and grab its inode */
8292 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8294 goto fail_free_name
;
8296 filter
->inode
= igrab(d_inode(path
.dentry
));
8302 if (!filter
->inode
||
8303 !S_ISREG(filter
->inode
->i_mode
))
8304 /* free_filters_list() will iput() */
8307 event
->addr_filters
.nr_file_filters
++;
8310 /* ready to consume more filters */
8311 state
= IF_STATE_ACTION
;
8316 if (state
!= IF_STATE_ACTION
)
8326 free_filters_list(filters
);
8333 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8339 * Since this is called in perf_ioctl() path, we're already holding
8342 lockdep_assert_held(&event
->ctx
->mutex
);
8344 if (WARN_ON_ONCE(event
->parent
))
8347 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8349 goto fail_clear_files
;
8351 ret
= event
->pmu
->addr_filters_validate(&filters
);
8353 goto fail_free_filters
;
8355 /* remove existing filters, if any */
8356 perf_addr_filters_splice(event
, &filters
);
8358 /* install new filters */
8359 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8364 free_filters_list(&filters
);
8367 event
->addr_filters
.nr_file_filters
= 0;
8372 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8377 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8378 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8379 !has_addr_filter(event
))
8382 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8383 if (IS_ERR(filter_str
))
8384 return PTR_ERR(filter_str
);
8386 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8387 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8388 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
8390 else if (has_addr_filter(event
))
8391 ret
= perf_event_set_addr_filter(event
, filter_str
);
8398 * hrtimer based swevent callback
8401 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8403 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8404 struct perf_sample_data data
;
8405 struct pt_regs
*regs
;
8406 struct perf_event
*event
;
8409 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8411 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8412 return HRTIMER_NORESTART
;
8414 event
->pmu
->read(event
);
8416 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8417 regs
= get_irq_regs();
8419 if (regs
&& !perf_exclude_event(event
, regs
)) {
8420 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8421 if (__perf_event_overflow(event
, 1, &data
, regs
))
8422 ret
= HRTIMER_NORESTART
;
8425 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8426 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8431 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8433 struct hw_perf_event
*hwc
= &event
->hw
;
8436 if (!is_sampling_event(event
))
8439 period
= local64_read(&hwc
->period_left
);
8444 local64_set(&hwc
->period_left
, 0);
8446 period
= max_t(u64
, 10000, hwc
->sample_period
);
8448 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8449 HRTIMER_MODE_REL_PINNED
);
8452 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8454 struct hw_perf_event
*hwc
= &event
->hw
;
8456 if (is_sampling_event(event
)) {
8457 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8458 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8460 hrtimer_cancel(&hwc
->hrtimer
);
8464 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8466 struct hw_perf_event
*hwc
= &event
->hw
;
8468 if (!is_sampling_event(event
))
8471 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8472 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8475 * Since hrtimers have a fixed rate, we can do a static freq->period
8476 * mapping and avoid the whole period adjust feedback stuff.
8478 if (event
->attr
.freq
) {
8479 long freq
= event
->attr
.sample_freq
;
8481 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8482 hwc
->sample_period
= event
->attr
.sample_period
;
8483 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8484 hwc
->last_period
= hwc
->sample_period
;
8485 event
->attr
.freq
= 0;
8490 * Software event: cpu wall time clock
8493 static void cpu_clock_event_update(struct perf_event
*event
)
8498 now
= local_clock();
8499 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8500 local64_add(now
- prev
, &event
->count
);
8503 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8505 local64_set(&event
->hw
.prev_count
, local_clock());
8506 perf_swevent_start_hrtimer(event
);
8509 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8511 perf_swevent_cancel_hrtimer(event
);
8512 cpu_clock_event_update(event
);
8515 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8517 if (flags
& PERF_EF_START
)
8518 cpu_clock_event_start(event
, flags
);
8519 perf_event_update_userpage(event
);
8524 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8526 cpu_clock_event_stop(event
, flags
);
8529 static void cpu_clock_event_read(struct perf_event
*event
)
8531 cpu_clock_event_update(event
);
8534 static int cpu_clock_event_init(struct perf_event
*event
)
8536 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8539 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8543 * no branch sampling for software events
8545 if (has_branch_stack(event
))
8548 perf_swevent_init_hrtimer(event
);
8553 static struct pmu perf_cpu_clock
= {
8554 .task_ctx_nr
= perf_sw_context
,
8556 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8558 .event_init
= cpu_clock_event_init
,
8559 .add
= cpu_clock_event_add
,
8560 .del
= cpu_clock_event_del
,
8561 .start
= cpu_clock_event_start
,
8562 .stop
= cpu_clock_event_stop
,
8563 .read
= cpu_clock_event_read
,
8567 * Software event: task time clock
8570 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8575 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8577 local64_add(delta
, &event
->count
);
8580 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8582 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8583 perf_swevent_start_hrtimer(event
);
8586 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8588 perf_swevent_cancel_hrtimer(event
);
8589 task_clock_event_update(event
, event
->ctx
->time
);
8592 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8594 if (flags
& PERF_EF_START
)
8595 task_clock_event_start(event
, flags
);
8596 perf_event_update_userpage(event
);
8601 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8603 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8606 static void task_clock_event_read(struct perf_event
*event
)
8608 u64 now
= perf_clock();
8609 u64 delta
= now
- event
->ctx
->timestamp
;
8610 u64 time
= event
->ctx
->time
+ delta
;
8612 task_clock_event_update(event
, time
);
8615 static int task_clock_event_init(struct perf_event
*event
)
8617 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8620 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8624 * no branch sampling for software events
8626 if (has_branch_stack(event
))
8629 perf_swevent_init_hrtimer(event
);
8634 static struct pmu perf_task_clock
= {
8635 .task_ctx_nr
= perf_sw_context
,
8637 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8639 .event_init
= task_clock_event_init
,
8640 .add
= task_clock_event_add
,
8641 .del
= task_clock_event_del
,
8642 .start
= task_clock_event_start
,
8643 .stop
= task_clock_event_stop
,
8644 .read
= task_clock_event_read
,
8647 static void perf_pmu_nop_void(struct pmu
*pmu
)
8651 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8655 static int perf_pmu_nop_int(struct pmu
*pmu
)
8660 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8662 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8664 __this_cpu_write(nop_txn_flags
, flags
);
8666 if (flags
& ~PERF_PMU_TXN_ADD
)
8669 perf_pmu_disable(pmu
);
8672 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8674 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8676 __this_cpu_write(nop_txn_flags
, 0);
8678 if (flags
& ~PERF_PMU_TXN_ADD
)
8681 perf_pmu_enable(pmu
);
8685 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8687 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8689 __this_cpu_write(nop_txn_flags
, 0);
8691 if (flags
& ~PERF_PMU_TXN_ADD
)
8694 perf_pmu_enable(pmu
);
8697 static int perf_event_idx_default(struct perf_event
*event
)
8703 * Ensures all contexts with the same task_ctx_nr have the same
8704 * pmu_cpu_context too.
8706 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8713 list_for_each_entry(pmu
, &pmus
, entry
) {
8714 if (pmu
->task_ctx_nr
== ctxn
)
8715 return pmu
->pmu_cpu_context
;
8721 static void free_pmu_context(struct pmu
*pmu
)
8723 mutex_lock(&pmus_lock
);
8724 free_percpu(pmu
->pmu_cpu_context
);
8725 mutex_unlock(&pmus_lock
);
8729 * Let userspace know that this PMU supports address range filtering:
8731 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8732 struct device_attribute
*attr
,
8735 struct pmu
*pmu
= dev_get_drvdata(dev
);
8737 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8739 DEVICE_ATTR_RO(nr_addr_filters
);
8741 static struct idr pmu_idr
;
8744 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8746 struct pmu
*pmu
= dev_get_drvdata(dev
);
8748 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8750 static DEVICE_ATTR_RO(type
);
8753 perf_event_mux_interval_ms_show(struct device
*dev
,
8754 struct device_attribute
*attr
,
8757 struct pmu
*pmu
= dev_get_drvdata(dev
);
8759 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8762 static DEFINE_MUTEX(mux_interval_mutex
);
8765 perf_event_mux_interval_ms_store(struct device
*dev
,
8766 struct device_attribute
*attr
,
8767 const char *buf
, size_t count
)
8769 struct pmu
*pmu
= dev_get_drvdata(dev
);
8770 int timer
, cpu
, ret
;
8772 ret
= kstrtoint(buf
, 0, &timer
);
8779 /* same value, noting to do */
8780 if (timer
== pmu
->hrtimer_interval_ms
)
8783 mutex_lock(&mux_interval_mutex
);
8784 pmu
->hrtimer_interval_ms
= timer
;
8786 /* update all cpuctx for this PMU */
8788 for_each_online_cpu(cpu
) {
8789 struct perf_cpu_context
*cpuctx
;
8790 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8791 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
8793 cpu_function_call(cpu
,
8794 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
8797 mutex_unlock(&mux_interval_mutex
);
8801 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
8803 static struct attribute
*pmu_dev_attrs
[] = {
8804 &dev_attr_type
.attr
,
8805 &dev_attr_perf_event_mux_interval_ms
.attr
,
8808 ATTRIBUTE_GROUPS(pmu_dev
);
8810 static int pmu_bus_running
;
8811 static struct bus_type pmu_bus
= {
8812 .name
= "event_source",
8813 .dev_groups
= pmu_dev_groups
,
8816 static void pmu_dev_release(struct device
*dev
)
8821 static int pmu_dev_alloc(struct pmu
*pmu
)
8825 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
8829 pmu
->dev
->groups
= pmu
->attr_groups
;
8830 device_initialize(pmu
->dev
);
8831 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
8835 dev_set_drvdata(pmu
->dev
, pmu
);
8836 pmu
->dev
->bus
= &pmu_bus
;
8837 pmu
->dev
->release
= pmu_dev_release
;
8838 ret
= device_add(pmu
->dev
);
8842 /* For PMUs with address filters, throw in an extra attribute: */
8843 if (pmu
->nr_addr_filters
)
8844 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
8853 device_del(pmu
->dev
);
8856 put_device(pmu
->dev
);
8860 static struct lock_class_key cpuctx_mutex
;
8861 static struct lock_class_key cpuctx_lock
;
8863 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
8867 mutex_lock(&pmus_lock
);
8869 pmu
->pmu_disable_count
= alloc_percpu(int);
8870 if (!pmu
->pmu_disable_count
)
8879 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
8887 if (pmu_bus_running
) {
8888 ret
= pmu_dev_alloc(pmu
);
8894 if (pmu
->task_ctx_nr
== perf_hw_context
) {
8895 static int hw_context_taken
= 0;
8898 * Other than systems with heterogeneous CPUs, it never makes
8899 * sense for two PMUs to share perf_hw_context. PMUs which are
8900 * uncore must use perf_invalid_context.
8902 if (WARN_ON_ONCE(hw_context_taken
&&
8903 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
8904 pmu
->task_ctx_nr
= perf_invalid_context
;
8906 hw_context_taken
= 1;
8909 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
8910 if (pmu
->pmu_cpu_context
)
8911 goto got_cpu_context
;
8914 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
8915 if (!pmu
->pmu_cpu_context
)
8918 for_each_possible_cpu(cpu
) {
8919 struct perf_cpu_context
*cpuctx
;
8921 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8922 __perf_event_init_context(&cpuctx
->ctx
);
8923 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
8924 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
8925 cpuctx
->ctx
.pmu
= pmu
;
8927 __perf_mux_hrtimer_init(cpuctx
, cpu
);
8931 if (!pmu
->start_txn
) {
8932 if (pmu
->pmu_enable
) {
8934 * If we have pmu_enable/pmu_disable calls, install
8935 * transaction stubs that use that to try and batch
8936 * hardware accesses.
8938 pmu
->start_txn
= perf_pmu_start_txn
;
8939 pmu
->commit_txn
= perf_pmu_commit_txn
;
8940 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
8942 pmu
->start_txn
= perf_pmu_nop_txn
;
8943 pmu
->commit_txn
= perf_pmu_nop_int
;
8944 pmu
->cancel_txn
= perf_pmu_nop_void
;
8948 if (!pmu
->pmu_enable
) {
8949 pmu
->pmu_enable
= perf_pmu_nop_void
;
8950 pmu
->pmu_disable
= perf_pmu_nop_void
;
8953 if (!pmu
->event_idx
)
8954 pmu
->event_idx
= perf_event_idx_default
;
8956 list_add_rcu(&pmu
->entry
, &pmus
);
8957 atomic_set(&pmu
->exclusive_cnt
, 0);
8960 mutex_unlock(&pmus_lock
);
8965 device_del(pmu
->dev
);
8966 put_device(pmu
->dev
);
8969 if (pmu
->type
>= PERF_TYPE_MAX
)
8970 idr_remove(&pmu_idr
, pmu
->type
);
8973 free_percpu(pmu
->pmu_disable_count
);
8976 EXPORT_SYMBOL_GPL(perf_pmu_register
);
8978 void perf_pmu_unregister(struct pmu
*pmu
)
8982 mutex_lock(&pmus_lock
);
8983 remove_device
= pmu_bus_running
;
8984 list_del_rcu(&pmu
->entry
);
8985 mutex_unlock(&pmus_lock
);
8988 * We dereference the pmu list under both SRCU and regular RCU, so
8989 * synchronize against both of those.
8991 synchronize_srcu(&pmus_srcu
);
8994 free_percpu(pmu
->pmu_disable_count
);
8995 if (pmu
->type
>= PERF_TYPE_MAX
)
8996 idr_remove(&pmu_idr
, pmu
->type
);
8997 if (remove_device
) {
8998 if (pmu
->nr_addr_filters
)
8999 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9000 device_del(pmu
->dev
);
9001 put_device(pmu
->dev
);
9003 free_pmu_context(pmu
);
9005 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9007 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9009 struct perf_event_context
*ctx
= NULL
;
9012 if (!try_module_get(pmu
->module
))
9015 if (event
->group_leader
!= event
) {
9017 * This ctx->mutex can nest when we're called through
9018 * inheritance. See the perf_event_ctx_lock_nested() comment.
9020 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9021 SINGLE_DEPTH_NESTING
);
9026 ret
= pmu
->event_init(event
);
9029 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9032 module_put(pmu
->module
);
9037 static struct pmu
*perf_init_event(struct perf_event
*event
)
9039 struct pmu
*pmu
= NULL
;
9043 idx
= srcu_read_lock(&pmus_srcu
);
9045 /* Try parent's PMU first: */
9046 if (event
->parent
&& event
->parent
->pmu
) {
9047 pmu
= event
->parent
->pmu
;
9048 ret
= perf_try_init_event(pmu
, event
);
9054 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9057 ret
= perf_try_init_event(pmu
, event
);
9063 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9064 ret
= perf_try_init_event(pmu
, event
);
9068 if (ret
!= -ENOENT
) {
9073 pmu
= ERR_PTR(-ENOENT
);
9075 srcu_read_unlock(&pmus_srcu
, idx
);
9080 static void attach_sb_event(struct perf_event
*event
)
9082 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9084 raw_spin_lock(&pel
->lock
);
9085 list_add_rcu(&event
->sb_list
, &pel
->list
);
9086 raw_spin_unlock(&pel
->lock
);
9090 * We keep a list of all !task (and therefore per-cpu) events
9091 * that need to receive side-band records.
9093 * This avoids having to scan all the various PMU per-cpu contexts
9096 static void account_pmu_sb_event(struct perf_event
*event
)
9098 if (is_sb_event(event
))
9099 attach_sb_event(event
);
9102 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9107 if (is_cgroup_event(event
))
9108 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9111 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9112 static void account_freq_event_nohz(void)
9114 #ifdef CONFIG_NO_HZ_FULL
9115 /* Lock so we don't race with concurrent unaccount */
9116 spin_lock(&nr_freq_lock
);
9117 if (atomic_inc_return(&nr_freq_events
) == 1)
9118 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9119 spin_unlock(&nr_freq_lock
);
9123 static void account_freq_event(void)
9125 if (tick_nohz_full_enabled())
9126 account_freq_event_nohz();
9128 atomic_inc(&nr_freq_events
);
9132 static void account_event(struct perf_event
*event
)
9139 if (event
->attach_state
& PERF_ATTACH_TASK
)
9141 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9142 atomic_inc(&nr_mmap_events
);
9143 if (event
->attr
.comm
)
9144 atomic_inc(&nr_comm_events
);
9145 if (event
->attr
.task
)
9146 atomic_inc(&nr_task_events
);
9147 if (event
->attr
.freq
)
9148 account_freq_event();
9149 if (event
->attr
.context_switch
) {
9150 atomic_inc(&nr_switch_events
);
9153 if (has_branch_stack(event
))
9155 if (is_cgroup_event(event
))
9159 if (atomic_inc_not_zero(&perf_sched_count
))
9162 mutex_lock(&perf_sched_mutex
);
9163 if (!atomic_read(&perf_sched_count
)) {
9164 static_branch_enable(&perf_sched_events
);
9166 * Guarantee that all CPUs observe they key change and
9167 * call the perf scheduling hooks before proceeding to
9168 * install events that need them.
9170 synchronize_sched();
9173 * Now that we have waited for the sync_sched(), allow further
9174 * increments to by-pass the mutex.
9176 atomic_inc(&perf_sched_count
);
9177 mutex_unlock(&perf_sched_mutex
);
9181 account_event_cpu(event
, event
->cpu
);
9183 account_pmu_sb_event(event
);
9187 * Allocate and initialize a event structure
9189 static struct perf_event
*
9190 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9191 struct task_struct
*task
,
9192 struct perf_event
*group_leader
,
9193 struct perf_event
*parent_event
,
9194 perf_overflow_handler_t overflow_handler
,
9195 void *context
, int cgroup_fd
)
9198 struct perf_event
*event
;
9199 struct hw_perf_event
*hwc
;
9202 if ((unsigned)cpu
>= nr_cpu_ids
) {
9203 if (!task
|| cpu
!= -1)
9204 return ERR_PTR(-EINVAL
);
9207 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9209 return ERR_PTR(-ENOMEM
);
9212 * Single events are their own group leaders, with an
9213 * empty sibling list:
9216 group_leader
= event
;
9218 mutex_init(&event
->child_mutex
);
9219 INIT_LIST_HEAD(&event
->child_list
);
9221 INIT_LIST_HEAD(&event
->group_entry
);
9222 INIT_LIST_HEAD(&event
->event_entry
);
9223 INIT_LIST_HEAD(&event
->sibling_list
);
9224 INIT_LIST_HEAD(&event
->rb_entry
);
9225 INIT_LIST_HEAD(&event
->active_entry
);
9226 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9227 INIT_HLIST_NODE(&event
->hlist_entry
);
9230 init_waitqueue_head(&event
->waitq
);
9231 init_irq_work(&event
->pending
, perf_pending_event
);
9233 mutex_init(&event
->mmap_mutex
);
9234 raw_spin_lock_init(&event
->addr_filters
.lock
);
9236 atomic_long_set(&event
->refcount
, 1);
9238 event
->attr
= *attr
;
9239 event
->group_leader
= group_leader
;
9243 event
->parent
= parent_event
;
9245 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9246 event
->id
= atomic64_inc_return(&perf_event_id
);
9248 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9251 event
->attach_state
= PERF_ATTACH_TASK
;
9253 * XXX pmu::event_init needs to know what task to account to
9254 * and we cannot use the ctx information because we need the
9255 * pmu before we get a ctx.
9257 event
->hw
.target
= task
;
9260 event
->clock
= &local_clock
;
9262 event
->clock
= parent_event
->clock
;
9264 if (!overflow_handler
&& parent_event
) {
9265 overflow_handler
= parent_event
->overflow_handler
;
9266 context
= parent_event
->overflow_handler_context
;
9267 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9268 if (overflow_handler
== bpf_overflow_handler
) {
9269 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9272 err
= PTR_ERR(prog
);
9276 event
->orig_overflow_handler
=
9277 parent_event
->orig_overflow_handler
;
9282 if (overflow_handler
) {
9283 event
->overflow_handler
= overflow_handler
;
9284 event
->overflow_handler_context
= context
;
9285 } else if (is_write_backward(event
)){
9286 event
->overflow_handler
= perf_event_output_backward
;
9287 event
->overflow_handler_context
= NULL
;
9289 event
->overflow_handler
= perf_event_output_forward
;
9290 event
->overflow_handler_context
= NULL
;
9293 perf_event__state_init(event
);
9298 hwc
->sample_period
= attr
->sample_period
;
9299 if (attr
->freq
&& attr
->sample_freq
)
9300 hwc
->sample_period
= 1;
9301 hwc
->last_period
= hwc
->sample_period
;
9303 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9306 * we currently do not support PERF_FORMAT_GROUP on inherited events
9308 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
9311 if (!has_branch_stack(event
))
9312 event
->attr
.branch_sample_type
= 0;
9314 if (cgroup_fd
!= -1) {
9315 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9320 pmu
= perf_init_event(event
);
9323 else if (IS_ERR(pmu
)) {
9328 err
= exclusive_event_init(event
);
9332 if (has_addr_filter(event
)) {
9333 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9334 sizeof(unsigned long),
9336 if (!event
->addr_filters_offs
)
9339 /* force hw sync on the address filters */
9340 event
->addr_filters_gen
= 1;
9343 if (!event
->parent
) {
9344 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9345 err
= get_callchain_buffers(attr
->sample_max_stack
);
9347 goto err_addr_filters
;
9351 /* symmetric to unaccount_event() in _free_event() */
9352 account_event(event
);
9357 kfree(event
->addr_filters_offs
);
9360 exclusive_event_destroy(event
);
9364 event
->destroy(event
);
9365 module_put(pmu
->module
);
9367 if (is_cgroup_event(event
))
9368 perf_detach_cgroup(event
);
9370 put_pid_ns(event
->ns
);
9373 return ERR_PTR(err
);
9376 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9377 struct perf_event_attr
*attr
)
9382 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9386 * zero the full structure, so that a short copy will be nice.
9388 memset(attr
, 0, sizeof(*attr
));
9390 ret
= get_user(size
, &uattr
->size
);
9394 if (size
> PAGE_SIZE
) /* silly large */
9397 if (!size
) /* abi compat */
9398 size
= PERF_ATTR_SIZE_VER0
;
9400 if (size
< PERF_ATTR_SIZE_VER0
)
9404 * If we're handed a bigger struct than we know of,
9405 * ensure all the unknown bits are 0 - i.e. new
9406 * user-space does not rely on any kernel feature
9407 * extensions we dont know about yet.
9409 if (size
> sizeof(*attr
)) {
9410 unsigned char __user
*addr
;
9411 unsigned char __user
*end
;
9414 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9415 end
= (void __user
*)uattr
+ size
;
9417 for (; addr
< end
; addr
++) {
9418 ret
= get_user(val
, addr
);
9424 size
= sizeof(*attr
);
9427 ret
= copy_from_user(attr
, uattr
, size
);
9431 if (attr
->__reserved_1
)
9434 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9437 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9440 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9441 u64 mask
= attr
->branch_sample_type
;
9443 /* only using defined bits */
9444 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9447 /* at least one branch bit must be set */
9448 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9451 /* propagate priv level, when not set for branch */
9452 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9454 /* exclude_kernel checked on syscall entry */
9455 if (!attr
->exclude_kernel
)
9456 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9458 if (!attr
->exclude_user
)
9459 mask
|= PERF_SAMPLE_BRANCH_USER
;
9461 if (!attr
->exclude_hv
)
9462 mask
|= PERF_SAMPLE_BRANCH_HV
;
9464 * adjust user setting (for HW filter setup)
9466 attr
->branch_sample_type
= mask
;
9468 /* privileged levels capture (kernel, hv): check permissions */
9469 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9470 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9474 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9475 ret
= perf_reg_validate(attr
->sample_regs_user
);
9480 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9481 if (!arch_perf_have_user_stack_dump())
9485 * We have __u32 type for the size, but so far
9486 * we can only use __u16 as maximum due to the
9487 * __u16 sample size limit.
9489 if (attr
->sample_stack_user
>= USHRT_MAX
)
9491 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9495 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9496 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9501 put_user(sizeof(*attr
), &uattr
->size
);
9507 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9509 struct ring_buffer
*rb
= NULL
;
9515 /* don't allow circular references */
9516 if (event
== output_event
)
9520 * Don't allow cross-cpu buffers
9522 if (output_event
->cpu
!= event
->cpu
)
9526 * If its not a per-cpu rb, it must be the same task.
9528 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9532 * Mixing clocks in the same buffer is trouble you don't need.
9534 if (output_event
->clock
!= event
->clock
)
9538 * Either writing ring buffer from beginning or from end.
9539 * Mixing is not allowed.
9541 if (is_write_backward(output_event
) != is_write_backward(event
))
9545 * If both events generate aux data, they must be on the same PMU
9547 if (has_aux(event
) && has_aux(output_event
) &&
9548 event
->pmu
!= output_event
->pmu
)
9552 mutex_lock(&event
->mmap_mutex
);
9553 /* Can't redirect output if we've got an active mmap() */
9554 if (atomic_read(&event
->mmap_count
))
9558 /* get the rb we want to redirect to */
9559 rb
= ring_buffer_get(output_event
);
9564 ring_buffer_attach(event
, rb
);
9568 mutex_unlock(&event
->mmap_mutex
);
9574 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9580 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9583 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9585 bool nmi_safe
= false;
9588 case CLOCK_MONOTONIC
:
9589 event
->clock
= &ktime_get_mono_fast_ns
;
9593 case CLOCK_MONOTONIC_RAW
:
9594 event
->clock
= &ktime_get_raw_fast_ns
;
9598 case CLOCK_REALTIME
:
9599 event
->clock
= &ktime_get_real_ns
;
9602 case CLOCK_BOOTTIME
:
9603 event
->clock
= &ktime_get_boot_ns
;
9607 event
->clock
= &ktime_get_tai_ns
;
9614 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9621 * Variation on perf_event_ctx_lock_nested(), except we take two context
9624 static struct perf_event_context
*
9625 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9626 struct perf_event_context
*ctx
)
9628 struct perf_event_context
*gctx
;
9632 gctx
= READ_ONCE(group_leader
->ctx
);
9633 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9639 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9641 if (group_leader
->ctx
!= gctx
) {
9642 mutex_unlock(&ctx
->mutex
);
9643 mutex_unlock(&gctx
->mutex
);
9652 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9654 * @attr_uptr: event_id type attributes for monitoring/sampling
9657 * @group_fd: group leader event fd
9659 SYSCALL_DEFINE5(perf_event_open
,
9660 struct perf_event_attr __user
*, attr_uptr
,
9661 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9663 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9664 struct perf_event
*event
, *sibling
;
9665 struct perf_event_attr attr
;
9666 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9667 struct file
*event_file
= NULL
;
9668 struct fd group
= {NULL
, 0};
9669 struct task_struct
*task
= NULL
;
9674 int f_flags
= O_RDWR
;
9677 /* for future expandability... */
9678 if (flags
& ~PERF_FLAG_ALL
)
9681 err
= perf_copy_attr(attr_uptr
, &attr
);
9685 if (!attr
.exclude_kernel
) {
9686 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9691 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9694 if (attr
.sample_period
& (1ULL << 63))
9698 if (!attr
.sample_max_stack
)
9699 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9702 * In cgroup mode, the pid argument is used to pass the fd
9703 * opened to the cgroup directory in cgroupfs. The cpu argument
9704 * designates the cpu on which to monitor threads from that
9707 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9710 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9711 f_flags
|= O_CLOEXEC
;
9713 event_fd
= get_unused_fd_flags(f_flags
);
9717 if (group_fd
!= -1) {
9718 err
= perf_fget_light(group_fd
, &group
);
9721 group_leader
= group
.file
->private_data
;
9722 if (flags
& PERF_FLAG_FD_OUTPUT
)
9723 output_event
= group_leader
;
9724 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9725 group_leader
= NULL
;
9728 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9729 task
= find_lively_task_by_vpid(pid
);
9731 err
= PTR_ERR(task
);
9736 if (task
&& group_leader
&&
9737 group_leader
->attr
.inherit
!= attr
.inherit
) {
9745 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
9750 * Reuse ptrace permission checks for now.
9752 * We must hold cred_guard_mutex across this and any potential
9753 * perf_install_in_context() call for this new event to
9754 * serialize against exec() altering our credentials (and the
9755 * perf_event_exit_task() that could imply).
9758 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
9762 if (flags
& PERF_FLAG_PID_CGROUP
)
9765 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
9766 NULL
, NULL
, cgroup_fd
);
9767 if (IS_ERR(event
)) {
9768 err
= PTR_ERR(event
);
9772 if (is_sampling_event(event
)) {
9773 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
9780 * Special case software events and allow them to be part of
9781 * any hardware group.
9785 if (attr
.use_clockid
) {
9786 err
= perf_event_set_clock(event
, attr
.clockid
);
9791 if (pmu
->task_ctx_nr
== perf_sw_context
)
9792 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
9795 (is_software_event(event
) != is_software_event(group_leader
))) {
9796 if (is_software_event(event
)) {
9798 * If event and group_leader are not both a software
9799 * event, and event is, then group leader is not.
9801 * Allow the addition of software events to !software
9802 * groups, this is safe because software events never
9805 pmu
= group_leader
->pmu
;
9806 } else if (is_software_event(group_leader
) &&
9807 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
9809 * In case the group is a pure software group, and we
9810 * try to add a hardware event, move the whole group to
9811 * the hardware context.
9818 * Get the target context (task or percpu):
9820 ctx
= find_get_context(pmu
, task
, event
);
9826 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
9832 * Look up the group leader (we will attach this event to it):
9838 * Do not allow a recursive hierarchy (this new sibling
9839 * becoming part of another group-sibling):
9841 if (group_leader
->group_leader
!= group_leader
)
9844 /* All events in a group should have the same clock */
9845 if (group_leader
->clock
!= event
->clock
)
9849 * Do not allow to attach to a group in a different
9850 * task or CPU context:
9854 * Make sure we're both on the same task, or both
9857 if (group_leader
->ctx
->task
!= ctx
->task
)
9861 * Make sure we're both events for the same CPU;
9862 * grouping events for different CPUs is broken; since
9863 * you can never concurrently schedule them anyhow.
9865 if (group_leader
->cpu
!= event
->cpu
)
9868 if (group_leader
->ctx
!= ctx
)
9873 * Only a group leader can be exclusive or pinned
9875 if (attr
.exclusive
|| attr
.pinned
)
9880 err
= perf_event_set_output(event
, output_event
);
9885 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
9887 if (IS_ERR(event_file
)) {
9888 err
= PTR_ERR(event_file
);
9894 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
9896 if (gctx
->task
== TASK_TOMBSTONE
) {
9902 * Check if we raced against another sys_perf_event_open() call
9903 * moving the software group underneath us.
9905 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
9907 * If someone moved the group out from under us, check
9908 * if this new event wound up on the same ctx, if so
9909 * its the regular !move_group case, otherwise fail.
9915 perf_event_ctx_unlock(group_leader
, gctx
);
9920 mutex_lock(&ctx
->mutex
);
9923 if (ctx
->task
== TASK_TOMBSTONE
) {
9928 if (!perf_event_validate_size(event
)) {
9934 * Must be under the same ctx::mutex as perf_install_in_context(),
9935 * because we need to serialize with concurrent event creation.
9937 if (!exclusive_event_installable(event
, ctx
)) {
9938 /* exclusive and group stuff are assumed mutually exclusive */
9939 WARN_ON_ONCE(move_group
);
9945 WARN_ON_ONCE(ctx
->parent_ctx
);
9948 * This is the point on no return; we cannot fail hereafter. This is
9949 * where we start modifying current state.
9954 * See perf_event_ctx_lock() for comments on the details
9955 * of swizzling perf_event::ctx.
9957 perf_remove_from_context(group_leader
, 0);
9959 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
9961 perf_remove_from_context(sibling
, 0);
9966 * Wait for everybody to stop referencing the events through
9967 * the old lists, before installing it on new lists.
9972 * Install the group siblings before the group leader.
9974 * Because a group leader will try and install the entire group
9975 * (through the sibling list, which is still in-tact), we can
9976 * end up with siblings installed in the wrong context.
9978 * By installing siblings first we NO-OP because they're not
9979 * reachable through the group lists.
9981 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
9983 perf_event__state_init(sibling
);
9984 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
9989 * Removing from the context ends up with disabled
9990 * event. What we want here is event in the initial
9991 * startup state, ready to be add into new context.
9993 perf_event__state_init(group_leader
);
9994 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
9998 * Now that all events are installed in @ctx, nothing
9999 * references @gctx anymore, so drop the last reference we have
10006 * Precalculate sample_data sizes; do while holding ctx::mutex such
10007 * that we're serialized against further additions and before
10008 * perf_install_in_context() which is the point the event is active and
10009 * can use these values.
10011 perf_event__header_size(event
);
10012 perf_event__id_header_size(event
);
10014 event
->owner
= current
;
10016 perf_install_in_context(ctx
, event
, event
->cpu
);
10017 perf_unpin_context(ctx
);
10020 perf_event_ctx_unlock(group_leader
, gctx
);
10021 mutex_unlock(&ctx
->mutex
);
10024 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10025 put_task_struct(task
);
10030 mutex_lock(¤t
->perf_event_mutex
);
10031 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10032 mutex_unlock(¤t
->perf_event_mutex
);
10035 * Drop the reference on the group_event after placing the
10036 * new event on the sibling_list. This ensures destruction
10037 * of the group leader will find the pointer to itself in
10038 * perf_group_detach().
10041 fd_install(event_fd
, event_file
);
10046 perf_event_ctx_unlock(group_leader
, gctx
);
10047 mutex_unlock(&ctx
->mutex
);
10051 perf_unpin_context(ctx
);
10055 * If event_file is set, the fput() above will have called ->release()
10056 * and that will take care of freeing the event.
10062 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10067 put_task_struct(task
);
10071 put_unused_fd(event_fd
);
10076 * perf_event_create_kernel_counter
10078 * @attr: attributes of the counter to create
10079 * @cpu: cpu in which the counter is bound
10080 * @task: task to profile (NULL for percpu)
10082 struct perf_event
*
10083 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10084 struct task_struct
*task
,
10085 perf_overflow_handler_t overflow_handler
,
10088 struct perf_event_context
*ctx
;
10089 struct perf_event
*event
;
10093 * Get the target context (task or percpu):
10096 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10097 overflow_handler
, context
, -1);
10098 if (IS_ERR(event
)) {
10099 err
= PTR_ERR(event
);
10103 /* Mark owner so we could distinguish it from user events. */
10104 event
->owner
= TASK_TOMBSTONE
;
10106 ctx
= find_get_context(event
->pmu
, task
, event
);
10108 err
= PTR_ERR(ctx
);
10112 WARN_ON_ONCE(ctx
->parent_ctx
);
10113 mutex_lock(&ctx
->mutex
);
10114 if (ctx
->task
== TASK_TOMBSTONE
) {
10119 if (!exclusive_event_installable(event
, ctx
)) {
10124 perf_install_in_context(ctx
, event
, cpu
);
10125 perf_unpin_context(ctx
);
10126 mutex_unlock(&ctx
->mutex
);
10131 mutex_unlock(&ctx
->mutex
);
10132 perf_unpin_context(ctx
);
10137 return ERR_PTR(err
);
10139 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10141 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10143 struct perf_event_context
*src_ctx
;
10144 struct perf_event_context
*dst_ctx
;
10145 struct perf_event
*event
, *tmp
;
10148 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10149 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10152 * See perf_event_ctx_lock() for comments on the details
10153 * of swizzling perf_event::ctx.
10155 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10156 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10158 perf_remove_from_context(event
, 0);
10159 unaccount_event_cpu(event
, src_cpu
);
10161 list_add(&event
->migrate_entry
, &events
);
10165 * Wait for the events to quiesce before re-instating them.
10170 * Re-instate events in 2 passes.
10172 * Skip over group leaders and only install siblings on this first
10173 * pass, siblings will not get enabled without a leader, however a
10174 * leader will enable its siblings, even if those are still on the old
10177 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10178 if (event
->group_leader
== event
)
10181 list_del(&event
->migrate_entry
);
10182 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10183 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10184 account_event_cpu(event
, dst_cpu
);
10185 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10190 * Once all the siblings are setup properly, install the group leaders
10193 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10194 list_del(&event
->migrate_entry
);
10195 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10196 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10197 account_event_cpu(event
, dst_cpu
);
10198 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10201 mutex_unlock(&dst_ctx
->mutex
);
10202 mutex_unlock(&src_ctx
->mutex
);
10204 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10206 static void sync_child_event(struct perf_event
*child_event
,
10207 struct task_struct
*child
)
10209 struct perf_event
*parent_event
= child_event
->parent
;
10212 if (child_event
->attr
.inherit_stat
)
10213 perf_event_read_event(child_event
, child
);
10215 child_val
= perf_event_count(child_event
);
10218 * Add back the child's count to the parent's count:
10220 atomic64_add(child_val
, &parent_event
->child_count
);
10221 atomic64_add(child_event
->total_time_enabled
,
10222 &parent_event
->child_total_time_enabled
);
10223 atomic64_add(child_event
->total_time_running
,
10224 &parent_event
->child_total_time_running
);
10228 perf_event_exit_event(struct perf_event
*child_event
,
10229 struct perf_event_context
*child_ctx
,
10230 struct task_struct
*child
)
10232 struct perf_event
*parent_event
= child_event
->parent
;
10235 * Do not destroy the 'original' grouping; because of the context
10236 * switch optimization the original events could've ended up in a
10237 * random child task.
10239 * If we were to destroy the original group, all group related
10240 * operations would cease to function properly after this random
10243 * Do destroy all inherited groups, we don't care about those
10244 * and being thorough is better.
10246 raw_spin_lock_irq(&child_ctx
->lock
);
10247 WARN_ON_ONCE(child_ctx
->is_active
);
10250 perf_group_detach(child_event
);
10251 list_del_event(child_event
, child_ctx
);
10252 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
10253 raw_spin_unlock_irq(&child_ctx
->lock
);
10256 * Parent events are governed by their filedesc, retain them.
10258 if (!parent_event
) {
10259 perf_event_wakeup(child_event
);
10263 * Child events can be cleaned up.
10266 sync_child_event(child_event
, child
);
10269 * Remove this event from the parent's list
10271 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10272 mutex_lock(&parent_event
->child_mutex
);
10273 list_del_init(&child_event
->child_list
);
10274 mutex_unlock(&parent_event
->child_mutex
);
10277 * Kick perf_poll() for is_event_hup().
10279 perf_event_wakeup(parent_event
);
10280 free_event(child_event
);
10281 put_event(parent_event
);
10284 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10286 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10287 struct perf_event
*child_event
, *next
;
10289 WARN_ON_ONCE(child
!= current
);
10291 child_ctx
= perf_pin_task_context(child
, ctxn
);
10296 * In order to reduce the amount of tricky in ctx tear-down, we hold
10297 * ctx::mutex over the entire thing. This serializes against almost
10298 * everything that wants to access the ctx.
10300 * The exception is sys_perf_event_open() /
10301 * perf_event_create_kernel_count() which does find_get_context()
10302 * without ctx::mutex (it cannot because of the move_group double mutex
10303 * lock thing). See the comments in perf_install_in_context().
10305 mutex_lock(&child_ctx
->mutex
);
10308 * In a single ctx::lock section, de-schedule the events and detach the
10309 * context from the task such that we cannot ever get it scheduled back
10312 raw_spin_lock_irq(&child_ctx
->lock
);
10313 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
10316 * Now that the context is inactive, destroy the task <-> ctx relation
10317 * and mark the context dead.
10319 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10320 put_ctx(child_ctx
); /* cannot be last */
10321 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10322 put_task_struct(current
); /* cannot be last */
10324 clone_ctx
= unclone_ctx(child_ctx
);
10325 raw_spin_unlock_irq(&child_ctx
->lock
);
10328 put_ctx(clone_ctx
);
10331 * Report the task dead after unscheduling the events so that we
10332 * won't get any samples after PERF_RECORD_EXIT. We can however still
10333 * get a few PERF_RECORD_READ events.
10335 perf_event_task(child
, child_ctx
, 0);
10337 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10338 perf_event_exit_event(child_event
, child_ctx
, child
);
10340 mutex_unlock(&child_ctx
->mutex
);
10342 put_ctx(child_ctx
);
10346 * When a child task exits, feed back event values to parent events.
10348 * Can be called with cred_guard_mutex held when called from
10349 * install_exec_creds().
10351 void perf_event_exit_task(struct task_struct
*child
)
10353 struct perf_event
*event
, *tmp
;
10356 mutex_lock(&child
->perf_event_mutex
);
10357 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10359 list_del_init(&event
->owner_entry
);
10362 * Ensure the list deletion is visible before we clear
10363 * the owner, closes a race against perf_release() where
10364 * we need to serialize on the owner->perf_event_mutex.
10366 smp_store_release(&event
->owner
, NULL
);
10368 mutex_unlock(&child
->perf_event_mutex
);
10370 for_each_task_context_nr(ctxn
)
10371 perf_event_exit_task_context(child
, ctxn
);
10374 * The perf_event_exit_task_context calls perf_event_task
10375 * with child's task_ctx, which generates EXIT events for
10376 * child contexts and sets child->perf_event_ctxp[] to NULL.
10377 * At this point we need to send EXIT events to cpu contexts.
10379 perf_event_task(child
, NULL
, 0);
10382 static void perf_free_event(struct perf_event
*event
,
10383 struct perf_event_context
*ctx
)
10385 struct perf_event
*parent
= event
->parent
;
10387 if (WARN_ON_ONCE(!parent
))
10390 mutex_lock(&parent
->child_mutex
);
10391 list_del_init(&event
->child_list
);
10392 mutex_unlock(&parent
->child_mutex
);
10396 raw_spin_lock_irq(&ctx
->lock
);
10397 perf_group_detach(event
);
10398 list_del_event(event
, ctx
);
10399 raw_spin_unlock_irq(&ctx
->lock
);
10404 * Free an unexposed, unused context as created by inheritance by
10405 * perf_event_init_task below, used by fork() in case of fail.
10407 * Not all locks are strictly required, but take them anyway to be nice and
10408 * help out with the lockdep assertions.
10410 void perf_event_free_task(struct task_struct
*task
)
10412 struct perf_event_context
*ctx
;
10413 struct perf_event
*event
, *tmp
;
10416 for_each_task_context_nr(ctxn
) {
10417 ctx
= task
->perf_event_ctxp
[ctxn
];
10421 mutex_lock(&ctx
->mutex
);
10423 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
10425 perf_free_event(event
, ctx
);
10427 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
10429 perf_free_event(event
, ctx
);
10431 if (!list_empty(&ctx
->pinned_groups
) ||
10432 !list_empty(&ctx
->flexible_groups
))
10435 mutex_unlock(&ctx
->mutex
);
10441 void perf_event_delayed_put(struct task_struct
*task
)
10445 for_each_task_context_nr(ctxn
)
10446 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10449 struct file
*perf_event_get(unsigned int fd
)
10453 file
= fget_raw(fd
);
10455 return ERR_PTR(-EBADF
);
10457 if (file
->f_op
!= &perf_fops
) {
10459 return ERR_PTR(-EBADF
);
10465 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10468 return ERR_PTR(-EINVAL
);
10470 return &event
->attr
;
10474 * inherit a event from parent task to child task:
10476 static struct perf_event
*
10477 inherit_event(struct perf_event
*parent_event
,
10478 struct task_struct
*parent
,
10479 struct perf_event_context
*parent_ctx
,
10480 struct task_struct
*child
,
10481 struct perf_event
*group_leader
,
10482 struct perf_event_context
*child_ctx
)
10484 enum perf_event_active_state parent_state
= parent_event
->state
;
10485 struct perf_event
*child_event
;
10486 unsigned long flags
;
10489 * Instead of creating recursive hierarchies of events,
10490 * we link inherited events back to the original parent,
10491 * which has a filp for sure, which we use as the reference
10494 if (parent_event
->parent
)
10495 parent_event
= parent_event
->parent
;
10497 child_event
= perf_event_alloc(&parent_event
->attr
,
10500 group_leader
, parent_event
,
10502 if (IS_ERR(child_event
))
10503 return child_event
;
10506 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10507 * must be under the same lock in order to serialize against
10508 * perf_event_release_kernel(), such that either we must observe
10509 * is_orphaned_event() or they will observe us on the child_list.
10511 mutex_lock(&parent_event
->child_mutex
);
10512 if (is_orphaned_event(parent_event
) ||
10513 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10514 mutex_unlock(&parent_event
->child_mutex
);
10515 free_event(child_event
);
10519 get_ctx(child_ctx
);
10522 * Make the child state follow the state of the parent event,
10523 * not its attr.disabled bit. We hold the parent's mutex,
10524 * so we won't race with perf_event_{en, dis}able_family.
10526 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10527 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10529 child_event
->state
= PERF_EVENT_STATE_OFF
;
10531 if (parent_event
->attr
.freq
) {
10532 u64 sample_period
= parent_event
->hw
.sample_period
;
10533 struct hw_perf_event
*hwc
= &child_event
->hw
;
10535 hwc
->sample_period
= sample_period
;
10536 hwc
->last_period
= sample_period
;
10538 local64_set(&hwc
->period_left
, sample_period
);
10541 child_event
->ctx
= child_ctx
;
10542 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10543 child_event
->overflow_handler_context
10544 = parent_event
->overflow_handler_context
;
10547 * Precalculate sample_data sizes
10549 perf_event__header_size(child_event
);
10550 perf_event__id_header_size(child_event
);
10553 * Link it up in the child's context:
10555 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10556 add_event_to_ctx(child_event
, child_ctx
);
10557 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10560 * Link this into the parent event's child list
10562 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10563 mutex_unlock(&parent_event
->child_mutex
);
10565 return child_event
;
10568 static int inherit_group(struct perf_event
*parent_event
,
10569 struct task_struct
*parent
,
10570 struct perf_event_context
*parent_ctx
,
10571 struct task_struct
*child
,
10572 struct perf_event_context
*child_ctx
)
10574 struct perf_event
*leader
;
10575 struct perf_event
*sub
;
10576 struct perf_event
*child_ctr
;
10578 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10579 child
, NULL
, child_ctx
);
10580 if (IS_ERR(leader
))
10581 return PTR_ERR(leader
);
10582 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10583 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10584 child
, leader
, child_ctx
);
10585 if (IS_ERR(child_ctr
))
10586 return PTR_ERR(child_ctr
);
10592 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10593 struct perf_event_context
*parent_ctx
,
10594 struct task_struct
*child
, int ctxn
,
10595 int *inherited_all
)
10598 struct perf_event_context
*child_ctx
;
10600 if (!event
->attr
.inherit
) {
10601 *inherited_all
= 0;
10605 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10608 * This is executed from the parent task context, so
10609 * inherit events that have been marked for cloning.
10610 * First allocate and initialize a context for the
10614 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10618 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10621 ret
= inherit_group(event
, parent
, parent_ctx
,
10625 *inherited_all
= 0;
10631 * Initialize the perf_event context in task_struct
10633 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10635 struct perf_event_context
*child_ctx
, *parent_ctx
;
10636 struct perf_event_context
*cloned_ctx
;
10637 struct perf_event
*event
;
10638 struct task_struct
*parent
= current
;
10639 int inherited_all
= 1;
10640 unsigned long flags
;
10643 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10647 * If the parent's context is a clone, pin it so it won't get
10648 * swapped under us.
10650 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10655 * No need to check if parent_ctx != NULL here; since we saw
10656 * it non-NULL earlier, the only reason for it to become NULL
10657 * is if we exit, and since we're currently in the middle of
10658 * a fork we can't be exiting at the same time.
10662 * Lock the parent list. No need to lock the child - not PID
10663 * hashed yet and not running, so nobody can access it.
10665 mutex_lock(&parent_ctx
->mutex
);
10668 * We dont have to disable NMIs - we are only looking at
10669 * the list, not manipulating it:
10671 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10672 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10673 child
, ctxn
, &inherited_all
);
10679 * We can't hold ctx->lock when iterating the ->flexible_group list due
10680 * to allocations, but we need to prevent rotation because
10681 * rotate_ctx() will change the list from interrupt context.
10683 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10684 parent_ctx
->rotate_disable
= 1;
10685 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10687 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10688 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10689 child
, ctxn
, &inherited_all
);
10694 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10695 parent_ctx
->rotate_disable
= 0;
10697 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10699 if (child_ctx
&& inherited_all
) {
10701 * Mark the child context as a clone of the parent
10702 * context, or of whatever the parent is a clone of.
10704 * Note that if the parent is a clone, the holding of
10705 * parent_ctx->lock avoids it from being uncloned.
10707 cloned_ctx
= parent_ctx
->parent_ctx
;
10709 child_ctx
->parent_ctx
= cloned_ctx
;
10710 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
10712 child_ctx
->parent_ctx
= parent_ctx
;
10713 child_ctx
->parent_gen
= parent_ctx
->generation
;
10715 get_ctx(child_ctx
->parent_ctx
);
10718 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10719 mutex_unlock(&parent_ctx
->mutex
);
10721 perf_unpin_context(parent_ctx
);
10722 put_ctx(parent_ctx
);
10728 * Initialize the perf_event context in task_struct
10730 int perf_event_init_task(struct task_struct
*child
)
10734 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
10735 mutex_init(&child
->perf_event_mutex
);
10736 INIT_LIST_HEAD(&child
->perf_event_list
);
10738 for_each_task_context_nr(ctxn
) {
10739 ret
= perf_event_init_context(child
, ctxn
);
10741 perf_event_free_task(child
);
10749 static void __init
perf_event_init_all_cpus(void)
10751 struct swevent_htable
*swhash
;
10754 for_each_possible_cpu(cpu
) {
10755 swhash
= &per_cpu(swevent_htable
, cpu
);
10756 mutex_init(&swhash
->hlist_mutex
);
10757 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
10759 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
10760 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
10762 #ifdef CONFIG_CGROUP_PERF
10763 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
10765 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
10769 int perf_event_init_cpu(unsigned int cpu
)
10771 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
10773 mutex_lock(&swhash
->hlist_mutex
);
10774 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
10775 struct swevent_hlist
*hlist
;
10777 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
10779 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
10781 mutex_unlock(&swhash
->hlist_mutex
);
10785 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
10786 static void __perf_event_exit_context(void *__info
)
10788 struct perf_event_context
*ctx
= __info
;
10789 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
10790 struct perf_event
*event
;
10792 raw_spin_lock(&ctx
->lock
);
10793 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
10794 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
10795 raw_spin_unlock(&ctx
->lock
);
10798 static void perf_event_exit_cpu_context(int cpu
)
10800 struct perf_event_context
*ctx
;
10804 idx
= srcu_read_lock(&pmus_srcu
);
10805 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
10806 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
10808 mutex_lock(&ctx
->mutex
);
10809 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
10810 mutex_unlock(&ctx
->mutex
);
10812 srcu_read_unlock(&pmus_srcu
, idx
);
10816 static void perf_event_exit_cpu_context(int cpu
) { }
10820 int perf_event_exit_cpu(unsigned int cpu
)
10822 perf_event_exit_cpu_context(cpu
);
10827 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
10831 for_each_online_cpu(cpu
)
10832 perf_event_exit_cpu(cpu
);
10838 * Run the perf reboot notifier at the very last possible moment so that
10839 * the generic watchdog code runs as long as possible.
10841 static struct notifier_block perf_reboot_notifier
= {
10842 .notifier_call
= perf_reboot
,
10843 .priority
= INT_MIN
,
10846 void __init
perf_event_init(void)
10850 idr_init(&pmu_idr
);
10852 perf_event_init_all_cpus();
10853 init_srcu_struct(&pmus_srcu
);
10854 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
10855 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
10856 perf_pmu_register(&perf_task_clock
, NULL
, -1);
10857 perf_tp_register();
10858 perf_event_init_cpu(smp_processor_id());
10859 register_reboot_notifier(&perf_reboot_notifier
);
10861 ret
= init_hw_breakpoint();
10862 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
10865 * Build time assertion that we keep the data_head at the intended
10866 * location. IOW, validation we got the __reserved[] size right.
10868 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
10872 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
10875 struct perf_pmu_events_attr
*pmu_attr
=
10876 container_of(attr
, struct perf_pmu_events_attr
, attr
);
10878 if (pmu_attr
->event_str
)
10879 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
10883 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
10885 static int __init
perf_event_sysfs_init(void)
10890 mutex_lock(&pmus_lock
);
10892 ret
= bus_register(&pmu_bus
);
10896 list_for_each_entry(pmu
, &pmus
, entry
) {
10897 if (!pmu
->name
|| pmu
->type
< 0)
10900 ret
= pmu_dev_alloc(pmu
);
10901 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
10903 pmu_bus_running
= 1;
10907 mutex_unlock(&pmus_lock
);
10911 device_initcall(perf_event_sysfs_init
);
10913 #ifdef CONFIG_CGROUP_PERF
10914 static struct cgroup_subsys_state
*
10915 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
10917 struct perf_cgroup
*jc
;
10919 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
10921 return ERR_PTR(-ENOMEM
);
10923 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
10926 return ERR_PTR(-ENOMEM
);
10932 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
10934 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
10936 free_percpu(jc
->info
);
10940 static int __perf_cgroup_move(void *info
)
10942 struct task_struct
*task
= info
;
10944 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
10949 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
10951 struct task_struct
*task
;
10952 struct cgroup_subsys_state
*css
;
10954 cgroup_taskset_for_each(task
, css
, tset
)
10955 task_function_call(task
, __perf_cgroup_move
, task
);
10958 struct cgroup_subsys perf_event_cgrp_subsys
= {
10959 .css_alloc
= perf_cgroup_css_alloc
,
10960 .css_free
= perf_cgroup_css_free
,
10961 .attach
= perf_cgroup_attach
,
10963 * Implicitly enable on dfl hierarchy so that perf events can
10964 * always be filtered by cgroup2 path as long as perf_event
10965 * controller is not mounted on a legacy hierarchy.
10967 .implicit_on_dfl
= true,
10969 #endif /* CONFIG_CGROUP_PERF */