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 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
362 * perf_sched_events : >0 events exist
363 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
366 static void perf_sched_delayed(struct work_struct
*work
);
367 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
368 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
369 static DEFINE_MUTEX(perf_sched_mutex
);
370 static atomic_t perf_sched_count
;
372 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
373 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
374 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
376 static atomic_t nr_mmap_events __read_mostly
;
377 static atomic_t nr_comm_events __read_mostly
;
378 static atomic_t nr_task_events __read_mostly
;
379 static atomic_t nr_freq_events __read_mostly
;
380 static atomic_t nr_switch_events __read_mostly
;
382 static LIST_HEAD(pmus
);
383 static DEFINE_MUTEX(pmus_lock
);
384 static struct srcu_struct pmus_srcu
;
387 * perf event paranoia level:
388 * -1 - not paranoid at all
389 * 0 - disallow raw tracepoint access for unpriv
390 * 1 - disallow cpu events for unpriv
391 * 2 - disallow kernel profiling for unpriv
393 int sysctl_perf_event_paranoid __read_mostly
= 2;
395 /* Minimum for 512 kiB + 1 user control page */
396 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
399 * max perf event sample rate
401 #define DEFAULT_MAX_SAMPLE_RATE 100000
402 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
403 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
405 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
407 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
408 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
410 static int perf_sample_allowed_ns __read_mostly
=
411 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
413 static void update_perf_cpu_limits(void)
415 u64 tmp
= perf_sample_period_ns
;
417 tmp
*= sysctl_perf_cpu_time_max_percent
;
418 tmp
= div_u64(tmp
, 100);
422 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
425 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
427 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
428 void __user
*buffer
, size_t *lenp
,
431 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
437 * If throttling is disabled don't allow the write:
439 if (sysctl_perf_cpu_time_max_percent
== 100 ||
440 sysctl_perf_cpu_time_max_percent
== 0)
443 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
444 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
445 update_perf_cpu_limits();
450 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
452 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
453 void __user
*buffer
, size_t *lenp
,
456 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
461 if (sysctl_perf_cpu_time_max_percent
== 100 ||
462 sysctl_perf_cpu_time_max_percent
== 0) {
464 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
465 WRITE_ONCE(perf_sample_allowed_ns
, 0);
467 update_perf_cpu_limits();
474 * perf samples are done in some very critical code paths (NMIs).
475 * If they take too much CPU time, the system can lock up and not
476 * get any real work done. This will drop the sample rate when
477 * we detect that events are taking too long.
479 #define NR_ACCUMULATED_SAMPLES 128
480 static DEFINE_PER_CPU(u64
, running_sample_length
);
482 static u64 __report_avg
;
483 static u64 __report_allowed
;
485 static void perf_duration_warn(struct irq_work
*w
)
487 printk_ratelimited(KERN_INFO
488 "perf: interrupt took too long (%lld > %lld), lowering "
489 "kernel.perf_event_max_sample_rate to %d\n",
490 __report_avg
, __report_allowed
,
491 sysctl_perf_event_sample_rate
);
494 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
496 void perf_sample_event_took(u64 sample_len_ns
)
498 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
506 /* Decay the counter by 1 average sample. */
507 running_len
= __this_cpu_read(running_sample_length
);
508 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
509 running_len
+= sample_len_ns
;
510 __this_cpu_write(running_sample_length
, running_len
);
513 * Note: this will be biased artifically low until we have
514 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
515 * from having to maintain a count.
517 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
518 if (avg_len
<= max_len
)
521 __report_avg
= avg_len
;
522 __report_allowed
= max_len
;
525 * Compute a throttle threshold 25% below the current duration.
527 avg_len
+= avg_len
/ 4;
528 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
534 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
535 WRITE_ONCE(max_samples_per_tick
, max
);
537 sysctl_perf_event_sample_rate
= max
* HZ
;
538 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
540 if (!irq_work_queue(&perf_duration_work
)) {
541 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
542 "kernel.perf_event_max_sample_rate to %d\n",
543 __report_avg
, __report_allowed
,
544 sysctl_perf_event_sample_rate
);
548 static atomic64_t perf_event_id
;
550 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
551 enum event_type_t event_type
);
553 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
554 enum event_type_t event_type
,
555 struct task_struct
*task
);
557 static void update_context_time(struct perf_event_context
*ctx
);
558 static u64
perf_event_time(struct perf_event
*event
);
560 void __weak
perf_event_print_debug(void) { }
562 extern __weak
const char *perf_pmu_name(void)
567 static inline u64
perf_clock(void)
569 return local_clock();
572 static inline u64
perf_event_clock(struct perf_event
*event
)
574 return event
->clock();
577 #ifdef CONFIG_CGROUP_PERF
580 perf_cgroup_match(struct perf_event
*event
)
582 struct perf_event_context
*ctx
= event
->ctx
;
583 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
585 /* @event doesn't care about cgroup */
589 /* wants specific cgroup scope but @cpuctx isn't associated with any */
594 * Cgroup scoping is recursive. An event enabled for a cgroup is
595 * also enabled for all its descendant cgroups. If @cpuctx's
596 * cgroup is a descendant of @event's (the test covers identity
597 * case), it's a match.
599 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
600 event
->cgrp
->css
.cgroup
);
603 static inline void perf_detach_cgroup(struct perf_event
*event
)
605 css_put(&event
->cgrp
->css
);
609 static inline int is_cgroup_event(struct perf_event
*event
)
611 return event
->cgrp
!= NULL
;
614 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
616 struct perf_cgroup_info
*t
;
618 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
622 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
624 struct perf_cgroup_info
*info
;
629 info
= this_cpu_ptr(cgrp
->info
);
631 info
->time
+= now
- info
->timestamp
;
632 info
->timestamp
= now
;
635 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
637 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
639 __update_cgrp_time(cgrp_out
);
642 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
644 struct perf_cgroup
*cgrp
;
647 * ensure we access cgroup data only when needed and
648 * when we know the cgroup is pinned (css_get)
650 if (!is_cgroup_event(event
))
653 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
655 * Do not update time when cgroup is not active
657 if (cgrp
== event
->cgrp
)
658 __update_cgrp_time(event
->cgrp
);
662 perf_cgroup_set_timestamp(struct task_struct
*task
,
663 struct perf_event_context
*ctx
)
665 struct perf_cgroup
*cgrp
;
666 struct perf_cgroup_info
*info
;
669 * ctx->lock held by caller
670 * ensure we do not access cgroup data
671 * unless we have the cgroup pinned (css_get)
673 if (!task
|| !ctx
->nr_cgroups
)
676 cgrp
= perf_cgroup_from_task(task
, ctx
);
677 info
= this_cpu_ptr(cgrp
->info
);
678 info
->timestamp
= ctx
->timestamp
;
681 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
682 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
685 * reschedule events based on the cgroup constraint of task.
687 * mode SWOUT : schedule out everything
688 * mode SWIN : schedule in based on cgroup for next
690 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
692 struct perf_cpu_context
*cpuctx
;
697 * disable interrupts to avoid geting nr_cgroup
698 * changes via __perf_event_disable(). Also
701 local_irq_save(flags
);
704 * we reschedule only in the presence of cgroup
705 * constrained events.
708 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
709 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
710 if (cpuctx
->unique_pmu
!= pmu
)
711 continue; /* ensure we process each cpuctx once */
714 * perf_cgroup_events says at least one
715 * context on this CPU has cgroup events.
717 * ctx->nr_cgroups reports the number of cgroup
718 * events for a context.
720 if (cpuctx
->ctx
.nr_cgroups
> 0) {
721 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
722 perf_pmu_disable(cpuctx
->ctx
.pmu
);
724 if (mode
& PERF_CGROUP_SWOUT
) {
725 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
727 * must not be done before ctxswout due
728 * to event_filter_match() in event_sched_out()
733 if (mode
& PERF_CGROUP_SWIN
) {
734 WARN_ON_ONCE(cpuctx
->cgrp
);
736 * set cgrp before ctxsw in to allow
737 * event_filter_match() to not have to pass
739 * we pass the cpuctx->ctx to perf_cgroup_from_task()
740 * because cgorup events are only per-cpu
742 cpuctx
->cgrp
= perf_cgroup_from_task(task
, &cpuctx
->ctx
);
743 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
745 perf_pmu_enable(cpuctx
->ctx
.pmu
);
746 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
750 local_irq_restore(flags
);
753 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
754 struct task_struct
*next
)
756 struct perf_cgroup
*cgrp1
;
757 struct perf_cgroup
*cgrp2
= NULL
;
761 * we come here when we know perf_cgroup_events > 0
762 * we do not need to pass the ctx here because we know
763 * we are holding the rcu lock
765 cgrp1
= perf_cgroup_from_task(task
, NULL
);
766 cgrp2
= perf_cgroup_from_task(next
, NULL
);
769 * only schedule out current cgroup events if we know
770 * that we are switching to a different cgroup. Otherwise,
771 * do no touch the cgroup events.
774 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
779 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
780 struct task_struct
*task
)
782 struct perf_cgroup
*cgrp1
;
783 struct perf_cgroup
*cgrp2
= NULL
;
787 * we come here when we know perf_cgroup_events > 0
788 * we do not need to pass the ctx here because we know
789 * we are holding the rcu lock
791 cgrp1
= perf_cgroup_from_task(task
, NULL
);
792 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
795 * only need to schedule in cgroup events if we are changing
796 * cgroup during ctxsw. Cgroup events were not scheduled
797 * out of ctxsw out if that was not the case.
800 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
805 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
806 struct perf_event_attr
*attr
,
807 struct perf_event
*group_leader
)
809 struct perf_cgroup
*cgrp
;
810 struct cgroup_subsys_state
*css
;
811 struct fd f
= fdget(fd
);
817 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
818 &perf_event_cgrp_subsys
);
824 cgrp
= container_of(css
, struct perf_cgroup
, css
);
828 * all events in a group must monitor
829 * the same cgroup because a task belongs
830 * to only one perf cgroup at a time
832 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
833 perf_detach_cgroup(event
);
842 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
844 struct perf_cgroup_info
*t
;
845 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
846 event
->shadow_ctx_time
= now
- t
->timestamp
;
850 perf_cgroup_defer_enabled(struct perf_event
*event
)
853 * when the current task's perf cgroup does not match
854 * the event's, we need to remember to call the
855 * perf_mark_enable() function the first time a task with
856 * a matching perf cgroup is scheduled in.
858 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
859 event
->cgrp_defer_enabled
= 1;
863 perf_cgroup_mark_enabled(struct perf_event
*event
,
864 struct perf_event_context
*ctx
)
866 struct perf_event
*sub
;
867 u64 tstamp
= perf_event_time(event
);
869 if (!event
->cgrp_defer_enabled
)
872 event
->cgrp_defer_enabled
= 0;
874 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
875 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
876 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
877 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
878 sub
->cgrp_defer_enabled
= 0;
884 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
885 * cleared when last cgroup event is removed.
888 list_update_cgroup_event(struct perf_event
*event
,
889 struct perf_event_context
*ctx
, bool add
)
891 struct perf_cpu_context
*cpuctx
;
893 if (!is_cgroup_event(event
))
896 if (add
&& ctx
->nr_cgroups
++)
898 else if (!add
&& --ctx
->nr_cgroups
)
901 * Because cgroup events are always per-cpu events,
902 * this will always be called from the right CPU.
904 cpuctx
= __get_cpu_context(ctx
);
905 cpuctx
->cgrp
= add
? event
->cgrp
: NULL
;
908 #else /* !CONFIG_CGROUP_PERF */
911 perf_cgroup_match(struct perf_event
*event
)
916 static inline void perf_detach_cgroup(struct perf_event
*event
)
919 static inline int is_cgroup_event(struct perf_event
*event
)
924 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
929 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
933 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
937 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
938 struct task_struct
*next
)
942 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
943 struct task_struct
*task
)
947 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
948 struct perf_event_attr
*attr
,
949 struct perf_event
*group_leader
)
955 perf_cgroup_set_timestamp(struct task_struct
*task
,
956 struct perf_event_context
*ctx
)
961 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
966 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
970 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
976 perf_cgroup_defer_enabled(struct perf_event
*event
)
981 perf_cgroup_mark_enabled(struct perf_event
*event
,
982 struct perf_event_context
*ctx
)
987 list_update_cgroup_event(struct perf_event
*event
,
988 struct perf_event_context
*ctx
, bool add
)
995 * set default to be dependent on timer tick just
998 #define PERF_CPU_HRTIMER (1000 / HZ)
1000 * function must be called with interrupts disbled
1002 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1004 struct perf_cpu_context
*cpuctx
;
1007 WARN_ON(!irqs_disabled());
1009 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1010 rotations
= perf_rotate_context(cpuctx
);
1012 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1014 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1016 cpuctx
->hrtimer_active
= 0;
1017 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1019 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1022 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1024 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1025 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1028 /* no multiplexing needed for SW PMU */
1029 if (pmu
->task_ctx_nr
== perf_sw_context
)
1033 * check default is sane, if not set then force to
1034 * default interval (1/tick)
1036 interval
= pmu
->hrtimer_interval_ms
;
1038 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1040 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1042 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1043 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1044 timer
->function
= perf_mux_hrtimer_handler
;
1047 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1049 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1050 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1051 unsigned long flags
;
1053 /* not for SW PMU */
1054 if (pmu
->task_ctx_nr
== perf_sw_context
)
1057 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1058 if (!cpuctx
->hrtimer_active
) {
1059 cpuctx
->hrtimer_active
= 1;
1060 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1061 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1063 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1068 void perf_pmu_disable(struct pmu
*pmu
)
1070 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1072 pmu
->pmu_disable(pmu
);
1075 void perf_pmu_enable(struct pmu
*pmu
)
1077 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1079 pmu
->pmu_enable(pmu
);
1082 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1085 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1086 * perf_event_task_tick() are fully serialized because they're strictly cpu
1087 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1088 * disabled, while perf_event_task_tick is called from IRQ context.
1090 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1092 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1094 WARN_ON(!irqs_disabled());
1096 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1098 list_add(&ctx
->active_ctx_list
, head
);
1101 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1103 WARN_ON(!irqs_disabled());
1105 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1107 list_del_init(&ctx
->active_ctx_list
);
1110 static void get_ctx(struct perf_event_context
*ctx
)
1112 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1115 static void free_ctx(struct rcu_head
*head
)
1117 struct perf_event_context
*ctx
;
1119 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1120 kfree(ctx
->task_ctx_data
);
1124 static void put_ctx(struct perf_event_context
*ctx
)
1126 if (atomic_dec_and_test(&ctx
->refcount
)) {
1127 if (ctx
->parent_ctx
)
1128 put_ctx(ctx
->parent_ctx
);
1129 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1130 put_task_struct(ctx
->task
);
1131 call_rcu(&ctx
->rcu_head
, free_ctx
);
1136 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1137 * perf_pmu_migrate_context() we need some magic.
1139 * Those places that change perf_event::ctx will hold both
1140 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1142 * Lock ordering is by mutex address. There are two other sites where
1143 * perf_event_context::mutex nests and those are:
1145 * - perf_event_exit_task_context() [ child , 0 ]
1146 * perf_event_exit_event()
1147 * put_event() [ parent, 1 ]
1149 * - perf_event_init_context() [ parent, 0 ]
1150 * inherit_task_group()
1153 * perf_event_alloc()
1155 * perf_try_init_event() [ child , 1 ]
1157 * While it appears there is an obvious deadlock here -- the parent and child
1158 * nesting levels are inverted between the two. This is in fact safe because
1159 * life-time rules separate them. That is an exiting task cannot fork, and a
1160 * spawning task cannot (yet) exit.
1162 * But remember that that these are parent<->child context relations, and
1163 * migration does not affect children, therefore these two orderings should not
1166 * The change in perf_event::ctx does not affect children (as claimed above)
1167 * because the sys_perf_event_open() case will install a new event and break
1168 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1169 * concerned with cpuctx and that doesn't have children.
1171 * The places that change perf_event::ctx will issue:
1173 * perf_remove_from_context();
1174 * synchronize_rcu();
1175 * perf_install_in_context();
1177 * to affect the change. The remove_from_context() + synchronize_rcu() should
1178 * quiesce the event, after which we can install it in the new location. This
1179 * means that only external vectors (perf_fops, prctl) can perturb the event
1180 * while in transit. Therefore all such accessors should also acquire
1181 * perf_event_context::mutex to serialize against this.
1183 * However; because event->ctx can change while we're waiting to acquire
1184 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1189 * task_struct::perf_event_mutex
1190 * perf_event_context::mutex
1191 * perf_event::child_mutex;
1192 * perf_event_context::lock
1193 * perf_event::mmap_mutex
1196 static struct perf_event_context
*
1197 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1199 struct perf_event_context
*ctx
;
1203 ctx
= ACCESS_ONCE(event
->ctx
);
1204 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1210 mutex_lock_nested(&ctx
->mutex
, nesting
);
1211 if (event
->ctx
!= ctx
) {
1212 mutex_unlock(&ctx
->mutex
);
1220 static inline struct perf_event_context
*
1221 perf_event_ctx_lock(struct perf_event
*event
)
1223 return perf_event_ctx_lock_nested(event
, 0);
1226 static void perf_event_ctx_unlock(struct perf_event
*event
,
1227 struct perf_event_context
*ctx
)
1229 mutex_unlock(&ctx
->mutex
);
1234 * This must be done under the ctx->lock, such as to serialize against
1235 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1236 * calling scheduler related locks and ctx->lock nests inside those.
1238 static __must_check
struct perf_event_context
*
1239 unclone_ctx(struct perf_event_context
*ctx
)
1241 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1243 lockdep_assert_held(&ctx
->lock
);
1246 ctx
->parent_ctx
= NULL
;
1252 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1255 * only top level events have the pid namespace they were created in
1258 event
= event
->parent
;
1260 return task_tgid_nr_ns(p
, event
->ns
);
1263 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1266 * only top level events have the pid namespace they were created in
1269 event
= event
->parent
;
1271 return task_pid_nr_ns(p
, event
->ns
);
1275 * If we inherit events we want to return the parent event id
1278 static u64
primary_event_id(struct perf_event
*event
)
1283 id
= event
->parent
->id
;
1289 * Get the perf_event_context for a task and lock it.
1291 * This has to cope with with the fact that until it is locked,
1292 * the context could get moved to another task.
1294 static struct perf_event_context
*
1295 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1297 struct perf_event_context
*ctx
;
1301 * One of the few rules of preemptible RCU is that one cannot do
1302 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1303 * part of the read side critical section was irqs-enabled -- see
1304 * rcu_read_unlock_special().
1306 * Since ctx->lock nests under rq->lock we must ensure the entire read
1307 * side critical section has interrupts disabled.
1309 local_irq_save(*flags
);
1311 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1314 * If this context is a clone of another, it might
1315 * get swapped for another underneath us by
1316 * perf_event_task_sched_out, though the
1317 * rcu_read_lock() protects us from any context
1318 * getting freed. Lock the context and check if it
1319 * got swapped before we could get the lock, and retry
1320 * if so. If we locked the right context, then it
1321 * can't get swapped on us any more.
1323 raw_spin_lock(&ctx
->lock
);
1324 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1325 raw_spin_unlock(&ctx
->lock
);
1327 local_irq_restore(*flags
);
1331 if (ctx
->task
== TASK_TOMBSTONE
||
1332 !atomic_inc_not_zero(&ctx
->refcount
)) {
1333 raw_spin_unlock(&ctx
->lock
);
1336 WARN_ON_ONCE(ctx
->task
!= task
);
1341 local_irq_restore(*flags
);
1346 * Get the context for a task and increment its pin_count so it
1347 * can't get swapped to another task. This also increments its
1348 * reference count so that the context can't get freed.
1350 static struct perf_event_context
*
1351 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1353 struct perf_event_context
*ctx
;
1354 unsigned long flags
;
1356 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1359 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1364 static void perf_unpin_context(struct perf_event_context
*ctx
)
1366 unsigned long flags
;
1368 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1370 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1374 * Update the record of the current time in a context.
1376 static void update_context_time(struct perf_event_context
*ctx
)
1378 u64 now
= perf_clock();
1380 ctx
->time
+= now
- ctx
->timestamp
;
1381 ctx
->timestamp
= now
;
1384 static u64
perf_event_time(struct perf_event
*event
)
1386 struct perf_event_context
*ctx
= event
->ctx
;
1388 if (is_cgroup_event(event
))
1389 return perf_cgroup_event_time(event
);
1391 return ctx
? ctx
->time
: 0;
1395 * Update the total_time_enabled and total_time_running fields for a event.
1397 static void update_event_times(struct perf_event
*event
)
1399 struct perf_event_context
*ctx
= event
->ctx
;
1402 lockdep_assert_held(&ctx
->lock
);
1404 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1405 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1409 * in cgroup mode, time_enabled represents
1410 * the time the event was enabled AND active
1411 * tasks were in the monitored cgroup. This is
1412 * independent of the activity of the context as
1413 * there may be a mix of cgroup and non-cgroup events.
1415 * That is why we treat cgroup events differently
1418 if (is_cgroup_event(event
))
1419 run_end
= perf_cgroup_event_time(event
);
1420 else if (ctx
->is_active
)
1421 run_end
= ctx
->time
;
1423 run_end
= event
->tstamp_stopped
;
1425 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1427 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1428 run_end
= event
->tstamp_stopped
;
1430 run_end
= perf_event_time(event
);
1432 event
->total_time_running
= run_end
- event
->tstamp_running
;
1437 * Update total_time_enabled and total_time_running for all events in a group.
1439 static void update_group_times(struct perf_event
*leader
)
1441 struct perf_event
*event
;
1443 update_event_times(leader
);
1444 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1445 update_event_times(event
);
1448 static struct list_head
*
1449 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1451 if (event
->attr
.pinned
)
1452 return &ctx
->pinned_groups
;
1454 return &ctx
->flexible_groups
;
1458 * Add a event from the lists for its context.
1459 * Must be called with ctx->mutex and ctx->lock held.
1462 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1465 lockdep_assert_held(&ctx
->lock
);
1467 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1468 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1471 * If we're a stand alone event or group leader, we go to the context
1472 * list, group events are kept attached to the group so that
1473 * perf_group_detach can, at all times, locate all siblings.
1475 if (event
->group_leader
== event
) {
1476 struct list_head
*list
;
1478 if (is_software_event(event
))
1479 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1481 list
= ctx_group_list(event
, ctx
);
1482 list_add_tail(&event
->group_entry
, list
);
1485 list_update_cgroup_event(event
, ctx
, true);
1487 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1489 if (event
->attr
.inherit_stat
)
1496 * Initialize event state based on the perf_event_attr::disabled.
1498 static inline void perf_event__state_init(struct perf_event
*event
)
1500 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1501 PERF_EVENT_STATE_INACTIVE
;
1504 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1506 int entry
= sizeof(u64
); /* value */
1510 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1511 size
+= sizeof(u64
);
1513 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1514 size
+= sizeof(u64
);
1516 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1517 entry
+= sizeof(u64
);
1519 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1521 size
+= sizeof(u64
);
1525 event
->read_size
= size
;
1528 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1530 struct perf_sample_data
*data
;
1533 if (sample_type
& PERF_SAMPLE_IP
)
1534 size
+= sizeof(data
->ip
);
1536 if (sample_type
& PERF_SAMPLE_ADDR
)
1537 size
+= sizeof(data
->addr
);
1539 if (sample_type
& PERF_SAMPLE_PERIOD
)
1540 size
+= sizeof(data
->period
);
1542 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1543 size
+= sizeof(data
->weight
);
1545 if (sample_type
& PERF_SAMPLE_READ
)
1546 size
+= event
->read_size
;
1548 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1549 size
+= sizeof(data
->data_src
.val
);
1551 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1552 size
+= sizeof(data
->txn
);
1554 event
->header_size
= size
;
1558 * Called at perf_event creation and when events are attached/detached from a
1561 static void perf_event__header_size(struct perf_event
*event
)
1563 __perf_event_read_size(event
,
1564 event
->group_leader
->nr_siblings
);
1565 __perf_event_header_size(event
, event
->attr
.sample_type
);
1568 static void perf_event__id_header_size(struct perf_event
*event
)
1570 struct perf_sample_data
*data
;
1571 u64 sample_type
= event
->attr
.sample_type
;
1574 if (sample_type
& PERF_SAMPLE_TID
)
1575 size
+= sizeof(data
->tid_entry
);
1577 if (sample_type
& PERF_SAMPLE_TIME
)
1578 size
+= sizeof(data
->time
);
1580 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1581 size
+= sizeof(data
->id
);
1583 if (sample_type
& PERF_SAMPLE_ID
)
1584 size
+= sizeof(data
->id
);
1586 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1587 size
+= sizeof(data
->stream_id
);
1589 if (sample_type
& PERF_SAMPLE_CPU
)
1590 size
+= sizeof(data
->cpu_entry
);
1592 event
->id_header_size
= size
;
1595 static bool perf_event_validate_size(struct perf_event
*event
)
1598 * The values computed here will be over-written when we actually
1601 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1602 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1603 perf_event__id_header_size(event
);
1606 * Sum the lot; should not exceed the 64k limit we have on records.
1607 * Conservative limit to allow for callchains and other variable fields.
1609 if (event
->read_size
+ event
->header_size
+
1610 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1616 static void perf_group_attach(struct perf_event
*event
)
1618 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1621 * We can have double attach due to group movement in perf_event_open.
1623 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1626 event
->attach_state
|= PERF_ATTACH_GROUP
;
1628 if (group_leader
== event
)
1631 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1633 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1634 !is_software_event(event
))
1635 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1637 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1638 group_leader
->nr_siblings
++;
1640 perf_event__header_size(group_leader
);
1642 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1643 perf_event__header_size(pos
);
1647 * Remove a event from the lists for its context.
1648 * Must be called with ctx->mutex and ctx->lock held.
1651 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1653 WARN_ON_ONCE(event
->ctx
!= ctx
);
1654 lockdep_assert_held(&ctx
->lock
);
1657 * We can have double detach due to exit/hot-unplug + close.
1659 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1662 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1664 list_update_cgroup_event(event
, ctx
, false);
1667 if (event
->attr
.inherit_stat
)
1670 list_del_rcu(&event
->event_entry
);
1672 if (event
->group_leader
== event
)
1673 list_del_init(&event
->group_entry
);
1675 update_group_times(event
);
1678 * If event was in error state, then keep it
1679 * that way, otherwise bogus counts will be
1680 * returned on read(). The only way to get out
1681 * of error state is by explicit re-enabling
1684 if (event
->state
> PERF_EVENT_STATE_OFF
)
1685 event
->state
= PERF_EVENT_STATE_OFF
;
1690 static void perf_group_detach(struct perf_event
*event
)
1692 struct perf_event
*sibling
, *tmp
;
1693 struct list_head
*list
= NULL
;
1696 * We can have double detach due to exit/hot-unplug + close.
1698 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1701 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1704 * If this is a sibling, remove it from its group.
1706 if (event
->group_leader
!= event
) {
1707 list_del_init(&event
->group_entry
);
1708 event
->group_leader
->nr_siblings
--;
1712 if (!list_empty(&event
->group_entry
))
1713 list
= &event
->group_entry
;
1716 * If this was a group event with sibling events then
1717 * upgrade the siblings to singleton events by adding them
1718 * to whatever list we are on.
1720 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1722 list_move_tail(&sibling
->group_entry
, list
);
1723 sibling
->group_leader
= sibling
;
1725 /* Inherit group flags from the previous leader */
1726 sibling
->group_flags
= event
->group_flags
;
1728 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1732 perf_event__header_size(event
->group_leader
);
1734 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1735 perf_event__header_size(tmp
);
1738 static bool is_orphaned_event(struct perf_event
*event
)
1740 return event
->state
== PERF_EVENT_STATE_DEAD
;
1743 static inline int __pmu_filter_match(struct perf_event
*event
)
1745 struct pmu
*pmu
= event
->pmu
;
1746 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1750 * Check whether we should attempt to schedule an event group based on
1751 * PMU-specific filtering. An event group can consist of HW and SW events,
1752 * potentially with a SW leader, so we must check all the filters, to
1753 * determine whether a group is schedulable:
1755 static inline int pmu_filter_match(struct perf_event
*event
)
1757 struct perf_event
*child
;
1759 if (!__pmu_filter_match(event
))
1762 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1763 if (!__pmu_filter_match(child
))
1771 event_filter_match(struct perf_event
*event
)
1773 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1774 perf_cgroup_match(event
) && pmu_filter_match(event
);
1778 event_sched_out(struct perf_event
*event
,
1779 struct perf_cpu_context
*cpuctx
,
1780 struct perf_event_context
*ctx
)
1782 u64 tstamp
= perf_event_time(event
);
1785 WARN_ON_ONCE(event
->ctx
!= ctx
);
1786 lockdep_assert_held(&ctx
->lock
);
1789 * An event which could not be activated because of
1790 * filter mismatch still needs to have its timings
1791 * maintained, otherwise bogus information is return
1792 * via read() for time_enabled, time_running:
1794 if (event
->state
== PERF_EVENT_STATE_INACTIVE
&&
1795 !event_filter_match(event
)) {
1796 delta
= tstamp
- event
->tstamp_stopped
;
1797 event
->tstamp_running
+= delta
;
1798 event
->tstamp_stopped
= tstamp
;
1801 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1804 perf_pmu_disable(event
->pmu
);
1806 event
->tstamp_stopped
= tstamp
;
1807 event
->pmu
->del(event
, 0);
1809 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1810 if (event
->pending_disable
) {
1811 event
->pending_disable
= 0;
1812 event
->state
= PERF_EVENT_STATE_OFF
;
1815 if (!is_software_event(event
))
1816 cpuctx
->active_oncpu
--;
1817 if (!--ctx
->nr_active
)
1818 perf_event_ctx_deactivate(ctx
);
1819 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1821 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1822 cpuctx
->exclusive
= 0;
1824 perf_pmu_enable(event
->pmu
);
1828 group_sched_out(struct perf_event
*group_event
,
1829 struct perf_cpu_context
*cpuctx
,
1830 struct perf_event_context
*ctx
)
1832 struct perf_event
*event
;
1833 int state
= group_event
->state
;
1835 event_sched_out(group_event
, cpuctx
, ctx
);
1838 * Schedule out siblings (if any):
1840 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1841 event_sched_out(event
, cpuctx
, ctx
);
1843 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1844 cpuctx
->exclusive
= 0;
1847 #define DETACH_GROUP 0x01UL
1850 * Cross CPU call to remove a performance event
1852 * We disable the event on the hardware level first. After that we
1853 * remove it from the context list.
1856 __perf_remove_from_context(struct perf_event
*event
,
1857 struct perf_cpu_context
*cpuctx
,
1858 struct perf_event_context
*ctx
,
1861 unsigned long flags
= (unsigned long)info
;
1863 event_sched_out(event
, cpuctx
, ctx
);
1864 if (flags
& DETACH_GROUP
)
1865 perf_group_detach(event
);
1866 list_del_event(event
, ctx
);
1868 if (!ctx
->nr_events
&& ctx
->is_active
) {
1871 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1872 cpuctx
->task_ctx
= NULL
;
1878 * Remove the event from a task's (or a CPU's) list of events.
1880 * If event->ctx is a cloned context, callers must make sure that
1881 * every task struct that event->ctx->task could possibly point to
1882 * remains valid. This is OK when called from perf_release since
1883 * that only calls us on the top-level context, which can't be a clone.
1884 * When called from perf_event_exit_task, it's OK because the
1885 * context has been detached from its task.
1887 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1889 lockdep_assert_held(&event
->ctx
->mutex
);
1891 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1895 * Cross CPU call to disable a performance event
1897 static void __perf_event_disable(struct perf_event
*event
,
1898 struct perf_cpu_context
*cpuctx
,
1899 struct perf_event_context
*ctx
,
1902 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1905 update_context_time(ctx
);
1906 update_cgrp_time_from_event(event
);
1907 update_group_times(event
);
1908 if (event
== event
->group_leader
)
1909 group_sched_out(event
, cpuctx
, ctx
);
1911 event_sched_out(event
, cpuctx
, ctx
);
1912 event
->state
= PERF_EVENT_STATE_OFF
;
1918 * If event->ctx is a cloned context, callers must make sure that
1919 * every task struct that event->ctx->task could possibly point to
1920 * remains valid. This condition is satisifed when called through
1921 * perf_event_for_each_child or perf_event_for_each because they
1922 * hold the top-level event's child_mutex, so any descendant that
1923 * goes to exit will block in perf_event_exit_event().
1925 * When called from perf_pending_event it's OK because event->ctx
1926 * is the current context on this CPU and preemption is disabled,
1927 * hence we can't get into perf_event_task_sched_out for this context.
1929 static void _perf_event_disable(struct perf_event
*event
)
1931 struct perf_event_context
*ctx
= event
->ctx
;
1933 raw_spin_lock_irq(&ctx
->lock
);
1934 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1935 raw_spin_unlock_irq(&ctx
->lock
);
1938 raw_spin_unlock_irq(&ctx
->lock
);
1940 event_function_call(event
, __perf_event_disable
, NULL
);
1943 void perf_event_disable_local(struct perf_event
*event
)
1945 event_function_local(event
, __perf_event_disable
, NULL
);
1949 * Strictly speaking kernel users cannot create groups and therefore this
1950 * interface does not need the perf_event_ctx_lock() magic.
1952 void perf_event_disable(struct perf_event
*event
)
1954 struct perf_event_context
*ctx
;
1956 ctx
= perf_event_ctx_lock(event
);
1957 _perf_event_disable(event
);
1958 perf_event_ctx_unlock(event
, ctx
);
1960 EXPORT_SYMBOL_GPL(perf_event_disable
);
1962 static void perf_set_shadow_time(struct perf_event
*event
,
1963 struct perf_event_context
*ctx
,
1967 * use the correct time source for the time snapshot
1969 * We could get by without this by leveraging the
1970 * fact that to get to this function, the caller
1971 * has most likely already called update_context_time()
1972 * and update_cgrp_time_xx() and thus both timestamp
1973 * are identical (or very close). Given that tstamp is,
1974 * already adjusted for cgroup, we could say that:
1975 * tstamp - ctx->timestamp
1977 * tstamp - cgrp->timestamp.
1979 * Then, in perf_output_read(), the calculation would
1980 * work with no changes because:
1981 * - event is guaranteed scheduled in
1982 * - no scheduled out in between
1983 * - thus the timestamp would be the same
1985 * But this is a bit hairy.
1987 * So instead, we have an explicit cgroup call to remain
1988 * within the time time source all along. We believe it
1989 * is cleaner and simpler to understand.
1991 if (is_cgroup_event(event
))
1992 perf_cgroup_set_shadow_time(event
, tstamp
);
1994 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1997 #define MAX_INTERRUPTS (~0ULL)
1999 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2000 static void perf_log_itrace_start(struct perf_event
*event
);
2003 event_sched_in(struct perf_event
*event
,
2004 struct perf_cpu_context
*cpuctx
,
2005 struct perf_event_context
*ctx
)
2007 u64 tstamp
= perf_event_time(event
);
2010 lockdep_assert_held(&ctx
->lock
);
2012 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2015 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2017 * Order event::oncpu write to happen before the ACTIVE state
2021 WRITE_ONCE(event
->state
, PERF_EVENT_STATE_ACTIVE
);
2024 * Unthrottle events, since we scheduled we might have missed several
2025 * ticks already, also for a heavily scheduling task there is little
2026 * guarantee it'll get a tick in a timely manner.
2028 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2029 perf_log_throttle(event
, 1);
2030 event
->hw
.interrupts
= 0;
2034 * The new state must be visible before we turn it on in the hardware:
2038 perf_pmu_disable(event
->pmu
);
2040 perf_set_shadow_time(event
, ctx
, tstamp
);
2042 perf_log_itrace_start(event
);
2044 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2045 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2051 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
2053 if (!is_software_event(event
))
2054 cpuctx
->active_oncpu
++;
2055 if (!ctx
->nr_active
++)
2056 perf_event_ctx_activate(ctx
);
2057 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2060 if (event
->attr
.exclusive
)
2061 cpuctx
->exclusive
= 1;
2064 perf_pmu_enable(event
->pmu
);
2070 group_sched_in(struct perf_event
*group_event
,
2071 struct perf_cpu_context
*cpuctx
,
2072 struct perf_event_context
*ctx
)
2074 struct perf_event
*event
, *partial_group
= NULL
;
2075 struct pmu
*pmu
= ctx
->pmu
;
2076 u64 now
= ctx
->time
;
2077 bool simulate
= false;
2079 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2082 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2084 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2085 pmu
->cancel_txn(pmu
);
2086 perf_mux_hrtimer_restart(cpuctx
);
2091 * Schedule in siblings as one group (if any):
2093 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2094 if (event_sched_in(event
, cpuctx
, ctx
)) {
2095 partial_group
= event
;
2100 if (!pmu
->commit_txn(pmu
))
2105 * Groups can be scheduled in as one unit only, so undo any
2106 * partial group before returning:
2107 * The events up to the failed event are scheduled out normally,
2108 * tstamp_stopped will be updated.
2110 * The failed events and the remaining siblings need to have
2111 * their timings updated as if they had gone thru event_sched_in()
2112 * and event_sched_out(). This is required to get consistent timings
2113 * across the group. This also takes care of the case where the group
2114 * could never be scheduled by ensuring tstamp_stopped is set to mark
2115 * the time the event was actually stopped, such that time delta
2116 * calculation in update_event_times() is correct.
2118 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2119 if (event
== partial_group
)
2123 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2124 event
->tstamp_stopped
= now
;
2126 event_sched_out(event
, cpuctx
, ctx
);
2129 event_sched_out(group_event
, cpuctx
, ctx
);
2131 pmu
->cancel_txn(pmu
);
2133 perf_mux_hrtimer_restart(cpuctx
);
2139 * Work out whether we can put this event group on the CPU now.
2141 static int group_can_go_on(struct perf_event
*event
,
2142 struct perf_cpu_context
*cpuctx
,
2146 * Groups consisting entirely of software events can always go on.
2148 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2151 * If an exclusive group is already on, no other hardware
2154 if (cpuctx
->exclusive
)
2157 * If this group is exclusive and there are already
2158 * events on the CPU, it can't go on.
2160 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2163 * Otherwise, try to add it if all previous groups were able
2169 static void add_event_to_ctx(struct perf_event
*event
,
2170 struct perf_event_context
*ctx
)
2172 u64 tstamp
= perf_event_time(event
);
2174 list_add_event(event
, ctx
);
2175 perf_group_attach(event
);
2176 event
->tstamp_enabled
= tstamp
;
2177 event
->tstamp_running
= tstamp
;
2178 event
->tstamp_stopped
= tstamp
;
2181 static void ctx_sched_out(struct perf_event_context
*ctx
,
2182 struct perf_cpu_context
*cpuctx
,
2183 enum event_type_t event_type
);
2185 ctx_sched_in(struct perf_event_context
*ctx
,
2186 struct perf_cpu_context
*cpuctx
,
2187 enum event_type_t event_type
,
2188 struct task_struct
*task
);
2190 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2191 struct perf_event_context
*ctx
)
2193 if (!cpuctx
->task_ctx
)
2196 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2199 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2202 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2203 struct perf_event_context
*ctx
,
2204 struct task_struct
*task
)
2206 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2208 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2209 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2211 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2214 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2215 struct perf_event_context
*task_ctx
)
2217 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2219 task_ctx_sched_out(cpuctx
, task_ctx
);
2220 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2221 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2222 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2226 * Cross CPU call to install and enable a performance event
2228 * Very similar to remote_function() + event_function() but cannot assume that
2229 * things like ctx->is_active and cpuctx->task_ctx are set.
2231 static int __perf_install_in_context(void *info
)
2233 struct perf_event
*event
= info
;
2234 struct perf_event_context
*ctx
= event
->ctx
;
2235 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2236 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2237 bool activate
= true;
2240 raw_spin_lock(&cpuctx
->ctx
.lock
);
2242 raw_spin_lock(&ctx
->lock
);
2245 /* If we're on the wrong CPU, try again */
2246 if (task_cpu(ctx
->task
) != smp_processor_id()) {
2252 * If we're on the right CPU, see if the task we target is
2253 * current, if not we don't have to activate the ctx, a future
2254 * context switch will do that for us.
2256 if (ctx
->task
!= current
)
2259 WARN_ON_ONCE(cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2261 } else if (task_ctx
) {
2262 raw_spin_lock(&task_ctx
->lock
);
2266 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2267 add_event_to_ctx(event
, ctx
);
2268 ctx_resched(cpuctx
, task_ctx
);
2270 add_event_to_ctx(event
, ctx
);
2274 perf_ctx_unlock(cpuctx
, task_ctx
);
2280 * Attach a performance event to a context.
2282 * Very similar to event_function_call, see comment there.
2285 perf_install_in_context(struct perf_event_context
*ctx
,
2286 struct perf_event
*event
,
2289 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2291 lockdep_assert_held(&ctx
->mutex
);
2293 if (event
->cpu
!= -1)
2297 * Ensures that if we can observe event->ctx, both the event and ctx
2298 * will be 'complete'. See perf_iterate_sb_cpu().
2300 smp_store_release(&event
->ctx
, ctx
);
2303 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2308 * Should not happen, we validate the ctx is still alive before calling.
2310 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2314 * Installing events is tricky because we cannot rely on ctx->is_active
2315 * to be set in case this is the nr_events 0 -> 1 transition.
2319 * Cannot use task_function_call() because we need to run on the task's
2320 * CPU regardless of whether its current or not.
2322 if (!cpu_function_call(task_cpu(task
), __perf_install_in_context
, event
))
2325 raw_spin_lock_irq(&ctx
->lock
);
2327 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2329 * Cannot happen because we already checked above (which also
2330 * cannot happen), and we hold ctx->mutex, which serializes us
2331 * against perf_event_exit_task_context().
2333 raw_spin_unlock_irq(&ctx
->lock
);
2336 raw_spin_unlock_irq(&ctx
->lock
);
2338 * Since !ctx->is_active doesn't mean anything, we must IPI
2345 * Put a event into inactive state and update time fields.
2346 * Enabling the leader of a group effectively enables all
2347 * the group members that aren't explicitly disabled, so we
2348 * have to update their ->tstamp_enabled also.
2349 * Note: this works for group members as well as group leaders
2350 * since the non-leader members' sibling_lists will be empty.
2352 static void __perf_event_mark_enabled(struct perf_event
*event
)
2354 struct perf_event
*sub
;
2355 u64 tstamp
= perf_event_time(event
);
2357 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2358 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2359 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2360 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2361 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2366 * Cross CPU call to enable a performance event
2368 static void __perf_event_enable(struct perf_event
*event
,
2369 struct perf_cpu_context
*cpuctx
,
2370 struct perf_event_context
*ctx
,
2373 struct perf_event
*leader
= event
->group_leader
;
2374 struct perf_event_context
*task_ctx
;
2376 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2377 event
->state
<= PERF_EVENT_STATE_ERROR
)
2381 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2383 __perf_event_mark_enabled(event
);
2385 if (!ctx
->is_active
)
2388 if (!event_filter_match(event
)) {
2389 if (is_cgroup_event(event
))
2390 perf_cgroup_defer_enabled(event
);
2391 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2396 * If the event is in a group and isn't the group leader,
2397 * then don't put it on unless the group is on.
2399 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2400 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2404 task_ctx
= cpuctx
->task_ctx
;
2406 WARN_ON_ONCE(task_ctx
!= ctx
);
2408 ctx_resched(cpuctx
, task_ctx
);
2414 * If event->ctx is a cloned context, callers must make sure that
2415 * every task struct that event->ctx->task could possibly point to
2416 * remains valid. This condition is satisfied when called through
2417 * perf_event_for_each_child or perf_event_for_each as described
2418 * for perf_event_disable.
2420 static void _perf_event_enable(struct perf_event
*event
)
2422 struct perf_event_context
*ctx
= event
->ctx
;
2424 raw_spin_lock_irq(&ctx
->lock
);
2425 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2426 event
->state
< PERF_EVENT_STATE_ERROR
) {
2427 raw_spin_unlock_irq(&ctx
->lock
);
2432 * If the event is in error state, clear that first.
2434 * That way, if we see the event in error state below, we know that it
2435 * has gone back into error state, as distinct from the task having
2436 * been scheduled away before the cross-call arrived.
2438 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2439 event
->state
= PERF_EVENT_STATE_OFF
;
2440 raw_spin_unlock_irq(&ctx
->lock
);
2442 event_function_call(event
, __perf_event_enable
, NULL
);
2446 * See perf_event_disable();
2448 void perf_event_enable(struct perf_event
*event
)
2450 struct perf_event_context
*ctx
;
2452 ctx
= perf_event_ctx_lock(event
);
2453 _perf_event_enable(event
);
2454 perf_event_ctx_unlock(event
, ctx
);
2456 EXPORT_SYMBOL_GPL(perf_event_enable
);
2458 struct stop_event_data
{
2459 struct perf_event
*event
;
2460 unsigned int restart
;
2463 static int __perf_event_stop(void *info
)
2465 struct stop_event_data
*sd
= info
;
2466 struct perf_event
*event
= sd
->event
;
2468 /* if it's already INACTIVE, do nothing */
2469 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2472 /* matches smp_wmb() in event_sched_in() */
2476 * There is a window with interrupts enabled before we get here,
2477 * so we need to check again lest we try to stop another CPU's event.
2479 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2482 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2485 * May race with the actual stop (through perf_pmu_output_stop()),
2486 * but it is only used for events with AUX ring buffer, and such
2487 * events will refuse to restart because of rb::aux_mmap_count==0,
2488 * see comments in perf_aux_output_begin().
2490 * Since this is happening on a event-local CPU, no trace is lost
2494 event
->pmu
->start(event
, PERF_EF_START
);
2499 static int perf_event_restart(struct perf_event
*event
)
2501 struct stop_event_data sd
= {
2508 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2511 /* matches smp_wmb() in event_sched_in() */
2515 * We only want to restart ACTIVE events, so if the event goes
2516 * inactive here (event->oncpu==-1), there's nothing more to do;
2517 * fall through with ret==-ENXIO.
2519 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2520 __perf_event_stop
, &sd
);
2521 } while (ret
== -EAGAIN
);
2527 * In order to contain the amount of racy and tricky in the address filter
2528 * configuration management, it is a two part process:
2530 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2531 * we update the addresses of corresponding vmas in
2532 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2533 * (p2) when an event is scheduled in (pmu::add), it calls
2534 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2535 * if the generation has changed since the previous call.
2537 * If (p1) happens while the event is active, we restart it to force (p2).
2539 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2540 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2542 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2543 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2545 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2548 void perf_event_addr_filters_sync(struct perf_event
*event
)
2550 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2552 if (!has_addr_filter(event
))
2555 raw_spin_lock(&ifh
->lock
);
2556 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2557 event
->pmu
->addr_filters_sync(event
);
2558 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2560 raw_spin_unlock(&ifh
->lock
);
2562 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2564 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2567 * not supported on inherited events
2569 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2572 atomic_add(refresh
, &event
->event_limit
);
2573 _perf_event_enable(event
);
2579 * See perf_event_disable()
2581 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2583 struct perf_event_context
*ctx
;
2586 ctx
= perf_event_ctx_lock(event
);
2587 ret
= _perf_event_refresh(event
, refresh
);
2588 perf_event_ctx_unlock(event
, ctx
);
2592 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2594 static void ctx_sched_out(struct perf_event_context
*ctx
,
2595 struct perf_cpu_context
*cpuctx
,
2596 enum event_type_t event_type
)
2598 int is_active
= ctx
->is_active
;
2599 struct perf_event
*event
;
2601 lockdep_assert_held(&ctx
->lock
);
2603 if (likely(!ctx
->nr_events
)) {
2605 * See __perf_remove_from_context().
2607 WARN_ON_ONCE(ctx
->is_active
);
2609 WARN_ON_ONCE(cpuctx
->task_ctx
);
2613 ctx
->is_active
&= ~event_type
;
2614 if (!(ctx
->is_active
& EVENT_ALL
))
2618 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2619 if (!ctx
->is_active
)
2620 cpuctx
->task_ctx
= NULL
;
2624 * Always update time if it was set; not only when it changes.
2625 * Otherwise we can 'forget' to update time for any but the last
2626 * context we sched out. For example:
2628 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2629 * ctx_sched_out(.event_type = EVENT_PINNED)
2631 * would only update time for the pinned events.
2633 if (is_active
& EVENT_TIME
) {
2634 /* update (and stop) ctx time */
2635 update_context_time(ctx
);
2636 update_cgrp_time_from_cpuctx(cpuctx
);
2639 is_active
^= ctx
->is_active
; /* changed bits */
2641 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2644 perf_pmu_disable(ctx
->pmu
);
2645 if (is_active
& EVENT_PINNED
) {
2646 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2647 group_sched_out(event
, cpuctx
, ctx
);
2650 if (is_active
& EVENT_FLEXIBLE
) {
2651 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2652 group_sched_out(event
, cpuctx
, ctx
);
2654 perf_pmu_enable(ctx
->pmu
);
2658 * Test whether two contexts are equivalent, i.e. whether they have both been
2659 * cloned from the same version of the same context.
2661 * Equivalence is measured using a generation number in the context that is
2662 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2663 * and list_del_event().
2665 static int context_equiv(struct perf_event_context
*ctx1
,
2666 struct perf_event_context
*ctx2
)
2668 lockdep_assert_held(&ctx1
->lock
);
2669 lockdep_assert_held(&ctx2
->lock
);
2671 /* Pinning disables the swap optimization */
2672 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2675 /* If ctx1 is the parent of ctx2 */
2676 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2679 /* If ctx2 is the parent of ctx1 */
2680 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2684 * If ctx1 and ctx2 have the same parent; we flatten the parent
2685 * hierarchy, see perf_event_init_context().
2687 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2688 ctx1
->parent_gen
== ctx2
->parent_gen
)
2695 static void __perf_event_sync_stat(struct perf_event
*event
,
2696 struct perf_event
*next_event
)
2700 if (!event
->attr
.inherit_stat
)
2704 * Update the event value, we cannot use perf_event_read()
2705 * because we're in the middle of a context switch and have IRQs
2706 * disabled, which upsets smp_call_function_single(), however
2707 * we know the event must be on the current CPU, therefore we
2708 * don't need to use it.
2710 switch (event
->state
) {
2711 case PERF_EVENT_STATE_ACTIVE
:
2712 event
->pmu
->read(event
);
2715 case PERF_EVENT_STATE_INACTIVE
:
2716 update_event_times(event
);
2724 * In order to keep per-task stats reliable we need to flip the event
2725 * values when we flip the contexts.
2727 value
= local64_read(&next_event
->count
);
2728 value
= local64_xchg(&event
->count
, value
);
2729 local64_set(&next_event
->count
, value
);
2731 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2732 swap(event
->total_time_running
, next_event
->total_time_running
);
2735 * Since we swizzled the values, update the user visible data too.
2737 perf_event_update_userpage(event
);
2738 perf_event_update_userpage(next_event
);
2741 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2742 struct perf_event_context
*next_ctx
)
2744 struct perf_event
*event
, *next_event
;
2749 update_context_time(ctx
);
2751 event
= list_first_entry(&ctx
->event_list
,
2752 struct perf_event
, event_entry
);
2754 next_event
= list_first_entry(&next_ctx
->event_list
,
2755 struct perf_event
, event_entry
);
2757 while (&event
->event_entry
!= &ctx
->event_list
&&
2758 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2760 __perf_event_sync_stat(event
, next_event
);
2762 event
= list_next_entry(event
, event_entry
);
2763 next_event
= list_next_entry(next_event
, event_entry
);
2767 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2768 struct task_struct
*next
)
2770 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2771 struct perf_event_context
*next_ctx
;
2772 struct perf_event_context
*parent
, *next_parent
;
2773 struct perf_cpu_context
*cpuctx
;
2779 cpuctx
= __get_cpu_context(ctx
);
2780 if (!cpuctx
->task_ctx
)
2784 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2788 parent
= rcu_dereference(ctx
->parent_ctx
);
2789 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2791 /* If neither context have a parent context; they cannot be clones. */
2792 if (!parent
&& !next_parent
)
2795 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2797 * Looks like the two contexts are clones, so we might be
2798 * able to optimize the context switch. We lock both
2799 * contexts and check that they are clones under the
2800 * lock (including re-checking that neither has been
2801 * uncloned in the meantime). It doesn't matter which
2802 * order we take the locks because no other cpu could
2803 * be trying to lock both of these tasks.
2805 raw_spin_lock(&ctx
->lock
);
2806 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2807 if (context_equiv(ctx
, next_ctx
)) {
2808 WRITE_ONCE(ctx
->task
, next
);
2809 WRITE_ONCE(next_ctx
->task
, task
);
2811 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2814 * RCU_INIT_POINTER here is safe because we've not
2815 * modified the ctx and the above modification of
2816 * ctx->task and ctx->task_ctx_data are immaterial
2817 * since those values are always verified under
2818 * ctx->lock which we're now holding.
2820 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2821 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2825 perf_event_sync_stat(ctx
, next_ctx
);
2827 raw_spin_unlock(&next_ctx
->lock
);
2828 raw_spin_unlock(&ctx
->lock
);
2834 raw_spin_lock(&ctx
->lock
);
2835 task_ctx_sched_out(cpuctx
, ctx
);
2836 raw_spin_unlock(&ctx
->lock
);
2840 void perf_sched_cb_dec(struct pmu
*pmu
)
2842 this_cpu_dec(perf_sched_cb_usages
);
2845 void perf_sched_cb_inc(struct pmu
*pmu
)
2847 this_cpu_inc(perf_sched_cb_usages
);
2851 * This function provides the context switch callback to the lower code
2852 * layer. It is invoked ONLY when the context switch callback is enabled.
2854 static void perf_pmu_sched_task(struct task_struct
*prev
,
2855 struct task_struct
*next
,
2858 struct perf_cpu_context
*cpuctx
;
2860 unsigned long flags
;
2865 local_irq_save(flags
);
2869 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2870 if (pmu
->sched_task
) {
2871 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2873 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2875 perf_pmu_disable(pmu
);
2877 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2879 perf_pmu_enable(pmu
);
2881 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2887 local_irq_restore(flags
);
2890 static void perf_event_switch(struct task_struct
*task
,
2891 struct task_struct
*next_prev
, bool sched_in
);
2893 #define for_each_task_context_nr(ctxn) \
2894 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2897 * Called from scheduler to remove the events of the current task,
2898 * with interrupts disabled.
2900 * We stop each event and update the event value in event->count.
2902 * This does not protect us against NMI, but disable()
2903 * sets the disabled bit in the control field of event _before_
2904 * accessing the event control register. If a NMI hits, then it will
2905 * not restart the event.
2907 void __perf_event_task_sched_out(struct task_struct
*task
,
2908 struct task_struct
*next
)
2912 if (__this_cpu_read(perf_sched_cb_usages
))
2913 perf_pmu_sched_task(task
, next
, false);
2915 if (atomic_read(&nr_switch_events
))
2916 perf_event_switch(task
, next
, false);
2918 for_each_task_context_nr(ctxn
)
2919 perf_event_context_sched_out(task
, ctxn
, next
);
2922 * if cgroup events exist on this CPU, then we need
2923 * to check if we have to switch out PMU state.
2924 * cgroup event are system-wide mode only
2926 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2927 perf_cgroup_sched_out(task
, next
);
2931 * Called with IRQs disabled
2933 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2934 enum event_type_t event_type
)
2936 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2940 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2941 struct perf_cpu_context
*cpuctx
)
2943 struct perf_event
*event
;
2945 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2946 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2948 if (!event_filter_match(event
))
2951 /* may need to reset tstamp_enabled */
2952 if (is_cgroup_event(event
))
2953 perf_cgroup_mark_enabled(event
, ctx
);
2955 if (group_can_go_on(event
, cpuctx
, 1))
2956 group_sched_in(event
, cpuctx
, ctx
);
2959 * If this pinned group hasn't been scheduled,
2960 * put it in error state.
2962 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2963 update_group_times(event
);
2964 event
->state
= PERF_EVENT_STATE_ERROR
;
2970 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2971 struct perf_cpu_context
*cpuctx
)
2973 struct perf_event
*event
;
2976 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2977 /* Ignore events in OFF or ERROR state */
2978 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2981 * Listen to the 'cpu' scheduling filter constraint
2984 if (!event_filter_match(event
))
2987 /* may need to reset tstamp_enabled */
2988 if (is_cgroup_event(event
))
2989 perf_cgroup_mark_enabled(event
, ctx
);
2991 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2992 if (group_sched_in(event
, cpuctx
, ctx
))
2999 ctx_sched_in(struct perf_event_context
*ctx
,
3000 struct perf_cpu_context
*cpuctx
,
3001 enum event_type_t event_type
,
3002 struct task_struct
*task
)
3004 int is_active
= ctx
->is_active
;
3007 lockdep_assert_held(&ctx
->lock
);
3009 if (likely(!ctx
->nr_events
))
3012 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3015 cpuctx
->task_ctx
= ctx
;
3017 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3020 is_active
^= ctx
->is_active
; /* changed bits */
3022 if (is_active
& EVENT_TIME
) {
3023 /* start ctx time */
3025 ctx
->timestamp
= now
;
3026 perf_cgroup_set_timestamp(task
, ctx
);
3030 * First go through the list and put on any pinned groups
3031 * in order to give them the best chance of going on.
3033 if (is_active
& EVENT_PINNED
)
3034 ctx_pinned_sched_in(ctx
, cpuctx
);
3036 /* Then walk through the lower prio flexible groups */
3037 if (is_active
& EVENT_FLEXIBLE
)
3038 ctx_flexible_sched_in(ctx
, cpuctx
);
3041 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3042 enum event_type_t event_type
,
3043 struct task_struct
*task
)
3045 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3047 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3050 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3051 struct task_struct
*task
)
3053 struct perf_cpu_context
*cpuctx
;
3055 cpuctx
= __get_cpu_context(ctx
);
3056 if (cpuctx
->task_ctx
== ctx
)
3059 perf_ctx_lock(cpuctx
, ctx
);
3060 perf_pmu_disable(ctx
->pmu
);
3062 * We want to keep the following priority order:
3063 * cpu pinned (that don't need to move), task pinned,
3064 * cpu flexible, task flexible.
3066 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3067 perf_event_sched_in(cpuctx
, ctx
, task
);
3068 perf_pmu_enable(ctx
->pmu
);
3069 perf_ctx_unlock(cpuctx
, ctx
);
3073 * Called from scheduler to add the events of the current task
3074 * with interrupts disabled.
3076 * We restore the event value and then enable it.
3078 * This does not protect us against NMI, but enable()
3079 * sets the enabled bit in the control field of event _before_
3080 * accessing the event control register. If a NMI hits, then it will
3081 * keep the event running.
3083 void __perf_event_task_sched_in(struct task_struct
*prev
,
3084 struct task_struct
*task
)
3086 struct perf_event_context
*ctx
;
3090 * If cgroup events exist on this CPU, then we need to check if we have
3091 * to switch in PMU state; cgroup event are system-wide mode only.
3093 * Since cgroup events are CPU events, we must schedule these in before
3094 * we schedule in the task events.
3096 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3097 perf_cgroup_sched_in(prev
, task
);
3099 for_each_task_context_nr(ctxn
) {
3100 ctx
= task
->perf_event_ctxp
[ctxn
];
3104 perf_event_context_sched_in(ctx
, task
);
3107 if (atomic_read(&nr_switch_events
))
3108 perf_event_switch(task
, prev
, true);
3110 if (__this_cpu_read(perf_sched_cb_usages
))
3111 perf_pmu_sched_task(prev
, task
, true);
3114 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3116 u64 frequency
= event
->attr
.sample_freq
;
3117 u64 sec
= NSEC_PER_SEC
;
3118 u64 divisor
, dividend
;
3120 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3122 count_fls
= fls64(count
);
3123 nsec_fls
= fls64(nsec
);
3124 frequency_fls
= fls64(frequency
);
3128 * We got @count in @nsec, with a target of sample_freq HZ
3129 * the target period becomes:
3132 * period = -------------------
3133 * @nsec * sample_freq
3138 * Reduce accuracy by one bit such that @a and @b converge
3139 * to a similar magnitude.
3141 #define REDUCE_FLS(a, b) \
3143 if (a##_fls > b##_fls) { \
3153 * Reduce accuracy until either term fits in a u64, then proceed with
3154 * the other, so that finally we can do a u64/u64 division.
3156 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3157 REDUCE_FLS(nsec
, frequency
);
3158 REDUCE_FLS(sec
, count
);
3161 if (count_fls
+ sec_fls
> 64) {
3162 divisor
= nsec
* frequency
;
3164 while (count_fls
+ sec_fls
> 64) {
3165 REDUCE_FLS(count
, sec
);
3169 dividend
= count
* sec
;
3171 dividend
= count
* sec
;
3173 while (nsec_fls
+ frequency_fls
> 64) {
3174 REDUCE_FLS(nsec
, frequency
);
3178 divisor
= nsec
* frequency
;
3184 return div64_u64(dividend
, divisor
);
3187 static DEFINE_PER_CPU(int, perf_throttled_count
);
3188 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3190 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3192 struct hw_perf_event
*hwc
= &event
->hw
;
3193 s64 period
, sample_period
;
3196 period
= perf_calculate_period(event
, nsec
, count
);
3198 delta
= (s64
)(period
- hwc
->sample_period
);
3199 delta
= (delta
+ 7) / 8; /* low pass filter */
3201 sample_period
= hwc
->sample_period
+ delta
;
3206 hwc
->sample_period
= sample_period
;
3208 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3210 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3212 local64_set(&hwc
->period_left
, 0);
3215 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3220 * combine freq adjustment with unthrottling to avoid two passes over the
3221 * events. At the same time, make sure, having freq events does not change
3222 * the rate of unthrottling as that would introduce bias.
3224 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3227 struct perf_event
*event
;
3228 struct hw_perf_event
*hwc
;
3229 u64 now
, period
= TICK_NSEC
;
3233 * only need to iterate over all events iff:
3234 * - context have events in frequency mode (needs freq adjust)
3235 * - there are events to unthrottle on this cpu
3237 if (!(ctx
->nr_freq
|| needs_unthr
))
3240 raw_spin_lock(&ctx
->lock
);
3241 perf_pmu_disable(ctx
->pmu
);
3243 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3244 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3247 if (!event_filter_match(event
))
3250 perf_pmu_disable(event
->pmu
);
3254 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3255 hwc
->interrupts
= 0;
3256 perf_log_throttle(event
, 1);
3257 event
->pmu
->start(event
, 0);
3260 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3264 * stop the event and update event->count
3266 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3268 now
= local64_read(&event
->count
);
3269 delta
= now
- hwc
->freq_count_stamp
;
3270 hwc
->freq_count_stamp
= now
;
3274 * reload only if value has changed
3275 * we have stopped the event so tell that
3276 * to perf_adjust_period() to avoid stopping it
3280 perf_adjust_period(event
, period
, delta
, false);
3282 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3284 perf_pmu_enable(event
->pmu
);
3287 perf_pmu_enable(ctx
->pmu
);
3288 raw_spin_unlock(&ctx
->lock
);
3292 * Round-robin a context's events:
3294 static void rotate_ctx(struct perf_event_context
*ctx
)
3297 * Rotate the first entry last of non-pinned groups. Rotation might be
3298 * disabled by the inheritance code.
3300 if (!ctx
->rotate_disable
)
3301 list_rotate_left(&ctx
->flexible_groups
);
3304 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3306 struct perf_event_context
*ctx
= NULL
;
3309 if (cpuctx
->ctx
.nr_events
) {
3310 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3314 ctx
= cpuctx
->task_ctx
;
3315 if (ctx
&& ctx
->nr_events
) {
3316 if (ctx
->nr_events
!= ctx
->nr_active
)
3323 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3324 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3326 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3328 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3330 rotate_ctx(&cpuctx
->ctx
);
3334 perf_event_sched_in(cpuctx
, ctx
, current
);
3336 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3337 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3343 void perf_event_task_tick(void)
3345 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3346 struct perf_event_context
*ctx
, *tmp
;
3349 WARN_ON(!irqs_disabled());
3351 __this_cpu_inc(perf_throttled_seq
);
3352 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3353 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3355 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3356 perf_adjust_freq_unthr_context(ctx
, throttled
);
3359 static int event_enable_on_exec(struct perf_event
*event
,
3360 struct perf_event_context
*ctx
)
3362 if (!event
->attr
.enable_on_exec
)
3365 event
->attr
.enable_on_exec
= 0;
3366 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3369 __perf_event_mark_enabled(event
);
3375 * Enable all of a task's events that have been marked enable-on-exec.
3376 * This expects task == current.
3378 static void perf_event_enable_on_exec(int ctxn
)
3380 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3381 struct perf_cpu_context
*cpuctx
;
3382 struct perf_event
*event
;
3383 unsigned long flags
;
3386 local_irq_save(flags
);
3387 ctx
= current
->perf_event_ctxp
[ctxn
];
3388 if (!ctx
|| !ctx
->nr_events
)
3391 cpuctx
= __get_cpu_context(ctx
);
3392 perf_ctx_lock(cpuctx
, ctx
);
3393 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3394 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
3395 enabled
|= event_enable_on_exec(event
, ctx
);
3398 * Unclone and reschedule this context if we enabled any event.
3401 clone_ctx
= unclone_ctx(ctx
);
3402 ctx_resched(cpuctx
, ctx
);
3404 perf_ctx_unlock(cpuctx
, ctx
);
3407 local_irq_restore(flags
);
3413 struct perf_read_data
{
3414 struct perf_event
*event
;
3420 * Cross CPU call to read the hardware event
3422 static void __perf_event_read(void *info
)
3424 struct perf_read_data
*data
= info
;
3425 struct perf_event
*sub
, *event
= data
->event
;
3426 struct perf_event_context
*ctx
= event
->ctx
;
3427 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3428 struct pmu
*pmu
= event
->pmu
;
3431 * If this is a task context, we need to check whether it is
3432 * the current task context of this cpu. If not it has been
3433 * scheduled out before the smp call arrived. In that case
3434 * event->count would have been updated to a recent sample
3435 * when the event was scheduled out.
3437 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3440 raw_spin_lock(&ctx
->lock
);
3441 if (ctx
->is_active
) {
3442 update_context_time(ctx
);
3443 update_cgrp_time_from_event(event
);
3446 update_event_times(event
);
3447 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3456 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3460 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3461 update_event_times(sub
);
3462 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3464 * Use sibling's PMU rather than @event's since
3465 * sibling could be on different (eg: software) PMU.
3467 sub
->pmu
->read(sub
);
3471 data
->ret
= pmu
->commit_txn(pmu
);
3474 raw_spin_unlock(&ctx
->lock
);
3477 static inline u64
perf_event_count(struct perf_event
*event
)
3479 if (event
->pmu
->count
)
3480 return event
->pmu
->count(event
);
3482 return __perf_event_count(event
);
3486 * NMI-safe method to read a local event, that is an event that
3488 * - either for the current task, or for this CPU
3489 * - does not have inherit set, for inherited task events
3490 * will not be local and we cannot read them atomically
3491 * - must not have a pmu::count method
3493 u64
perf_event_read_local(struct perf_event
*event
)
3495 unsigned long flags
;
3499 * Disabling interrupts avoids all counter scheduling (context
3500 * switches, timer based rotation and IPIs).
3502 local_irq_save(flags
);
3504 /* If this is a per-task event, it must be for current */
3505 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3506 event
->hw
.target
!= current
);
3508 /* If this is a per-CPU event, it must be for this CPU */
3509 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3510 event
->cpu
!= smp_processor_id());
3513 * It must not be an event with inherit set, we cannot read
3514 * all child counters from atomic context.
3516 WARN_ON_ONCE(event
->attr
.inherit
);
3519 * It must not have a pmu::count method, those are not
3522 WARN_ON_ONCE(event
->pmu
->count
);
3525 * If the event is currently on this CPU, its either a per-task event,
3526 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3529 if (event
->oncpu
== smp_processor_id())
3530 event
->pmu
->read(event
);
3532 val
= local64_read(&event
->count
);
3533 local_irq_restore(flags
);
3538 static int perf_event_read(struct perf_event
*event
, bool group
)
3543 * If event is enabled and currently active on a CPU, update the
3544 * value in the event structure:
3546 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3547 struct perf_read_data data
= {
3552 ret
= smp_call_function_single(event
->oncpu
, __perf_event_read
, &data
, 1);
3553 /* The event must have been read from an online CPU: */
3555 ret
= ret
? : data
.ret
;
3556 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3557 struct perf_event_context
*ctx
= event
->ctx
;
3558 unsigned long flags
;
3560 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3562 * may read while context is not active
3563 * (e.g., thread is blocked), in that case
3564 * we cannot update context time
3566 if (ctx
->is_active
) {
3567 update_context_time(ctx
);
3568 update_cgrp_time_from_event(event
);
3571 update_group_times(event
);
3573 update_event_times(event
);
3574 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3581 * Initialize the perf_event context in a task_struct:
3583 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3585 raw_spin_lock_init(&ctx
->lock
);
3586 mutex_init(&ctx
->mutex
);
3587 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3588 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3589 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3590 INIT_LIST_HEAD(&ctx
->event_list
);
3591 atomic_set(&ctx
->refcount
, 1);
3594 static struct perf_event_context
*
3595 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3597 struct perf_event_context
*ctx
;
3599 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3603 __perf_event_init_context(ctx
);
3606 get_task_struct(task
);
3613 static struct task_struct
*
3614 find_lively_task_by_vpid(pid_t vpid
)
3616 struct task_struct
*task
;
3622 task
= find_task_by_vpid(vpid
);
3624 get_task_struct(task
);
3628 return ERR_PTR(-ESRCH
);
3634 * Returns a matching context with refcount and pincount.
3636 static struct perf_event_context
*
3637 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3638 struct perf_event
*event
)
3640 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3641 struct perf_cpu_context
*cpuctx
;
3642 void *task_ctx_data
= NULL
;
3643 unsigned long flags
;
3645 int cpu
= event
->cpu
;
3648 /* Must be root to operate on a CPU event: */
3649 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3650 return ERR_PTR(-EACCES
);
3653 * We could be clever and allow to attach a event to an
3654 * offline CPU and activate it when the CPU comes up, but
3657 if (!cpu_online(cpu
))
3658 return ERR_PTR(-ENODEV
);
3660 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3669 ctxn
= pmu
->task_ctx_nr
;
3673 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3674 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3675 if (!task_ctx_data
) {
3682 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3684 clone_ctx
= unclone_ctx(ctx
);
3687 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3688 ctx
->task_ctx_data
= task_ctx_data
;
3689 task_ctx_data
= NULL
;
3691 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3696 ctx
= alloc_perf_context(pmu
, task
);
3701 if (task_ctx_data
) {
3702 ctx
->task_ctx_data
= task_ctx_data
;
3703 task_ctx_data
= NULL
;
3707 mutex_lock(&task
->perf_event_mutex
);
3709 * If it has already passed perf_event_exit_task().
3710 * we must see PF_EXITING, it takes this mutex too.
3712 if (task
->flags
& PF_EXITING
)
3714 else if (task
->perf_event_ctxp
[ctxn
])
3719 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3721 mutex_unlock(&task
->perf_event_mutex
);
3723 if (unlikely(err
)) {
3732 kfree(task_ctx_data
);
3736 kfree(task_ctx_data
);
3737 return ERR_PTR(err
);
3740 static void perf_event_free_filter(struct perf_event
*event
);
3741 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3743 static void free_event_rcu(struct rcu_head
*head
)
3745 struct perf_event
*event
;
3747 event
= container_of(head
, struct perf_event
, rcu_head
);
3749 put_pid_ns(event
->ns
);
3750 perf_event_free_filter(event
);
3754 static void ring_buffer_attach(struct perf_event
*event
,
3755 struct ring_buffer
*rb
);
3757 static void detach_sb_event(struct perf_event
*event
)
3759 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3761 raw_spin_lock(&pel
->lock
);
3762 list_del_rcu(&event
->sb_list
);
3763 raw_spin_unlock(&pel
->lock
);
3766 static bool is_sb_event(struct perf_event
*event
)
3768 struct perf_event_attr
*attr
= &event
->attr
;
3773 if (event
->attach_state
& PERF_ATTACH_TASK
)
3776 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3777 attr
->comm
|| attr
->comm_exec
||
3779 attr
->context_switch
)
3784 static void unaccount_pmu_sb_event(struct perf_event
*event
)
3786 if (is_sb_event(event
))
3787 detach_sb_event(event
);
3790 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3795 if (is_cgroup_event(event
))
3796 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3799 #ifdef CONFIG_NO_HZ_FULL
3800 static DEFINE_SPINLOCK(nr_freq_lock
);
3803 static void unaccount_freq_event_nohz(void)
3805 #ifdef CONFIG_NO_HZ_FULL
3806 spin_lock(&nr_freq_lock
);
3807 if (atomic_dec_and_test(&nr_freq_events
))
3808 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3809 spin_unlock(&nr_freq_lock
);
3813 static void unaccount_freq_event(void)
3815 if (tick_nohz_full_enabled())
3816 unaccount_freq_event_nohz();
3818 atomic_dec(&nr_freq_events
);
3821 static void unaccount_event(struct perf_event
*event
)
3828 if (event
->attach_state
& PERF_ATTACH_TASK
)
3830 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3831 atomic_dec(&nr_mmap_events
);
3832 if (event
->attr
.comm
)
3833 atomic_dec(&nr_comm_events
);
3834 if (event
->attr
.task
)
3835 atomic_dec(&nr_task_events
);
3836 if (event
->attr
.freq
)
3837 unaccount_freq_event();
3838 if (event
->attr
.context_switch
) {
3840 atomic_dec(&nr_switch_events
);
3842 if (is_cgroup_event(event
))
3844 if (has_branch_stack(event
))
3848 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
3849 schedule_delayed_work(&perf_sched_work
, HZ
);
3852 unaccount_event_cpu(event
, event
->cpu
);
3854 unaccount_pmu_sb_event(event
);
3857 static void perf_sched_delayed(struct work_struct
*work
)
3859 mutex_lock(&perf_sched_mutex
);
3860 if (atomic_dec_and_test(&perf_sched_count
))
3861 static_branch_disable(&perf_sched_events
);
3862 mutex_unlock(&perf_sched_mutex
);
3866 * The following implement mutual exclusion of events on "exclusive" pmus
3867 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3868 * at a time, so we disallow creating events that might conflict, namely:
3870 * 1) cpu-wide events in the presence of per-task events,
3871 * 2) per-task events in the presence of cpu-wide events,
3872 * 3) two matching events on the same context.
3874 * The former two cases are handled in the allocation path (perf_event_alloc(),
3875 * _free_event()), the latter -- before the first perf_install_in_context().
3877 static int exclusive_event_init(struct perf_event
*event
)
3879 struct pmu
*pmu
= event
->pmu
;
3881 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3885 * Prevent co-existence of per-task and cpu-wide events on the
3886 * same exclusive pmu.
3888 * Negative pmu::exclusive_cnt means there are cpu-wide
3889 * events on this "exclusive" pmu, positive means there are
3892 * Since this is called in perf_event_alloc() path, event::ctx
3893 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3894 * to mean "per-task event", because unlike other attach states it
3895 * never gets cleared.
3897 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3898 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3901 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3908 static void exclusive_event_destroy(struct perf_event
*event
)
3910 struct pmu
*pmu
= event
->pmu
;
3912 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3915 /* see comment in exclusive_event_init() */
3916 if (event
->attach_state
& PERF_ATTACH_TASK
)
3917 atomic_dec(&pmu
->exclusive_cnt
);
3919 atomic_inc(&pmu
->exclusive_cnt
);
3922 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3924 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3925 (e1
->cpu
== e2
->cpu
||
3932 /* Called under the same ctx::mutex as perf_install_in_context() */
3933 static bool exclusive_event_installable(struct perf_event
*event
,
3934 struct perf_event_context
*ctx
)
3936 struct perf_event
*iter_event
;
3937 struct pmu
*pmu
= event
->pmu
;
3939 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3942 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3943 if (exclusive_event_match(iter_event
, event
))
3950 static void perf_addr_filters_splice(struct perf_event
*event
,
3951 struct list_head
*head
);
3953 static void _free_event(struct perf_event
*event
)
3955 irq_work_sync(&event
->pending
);
3957 unaccount_event(event
);
3961 * Can happen when we close an event with re-directed output.
3963 * Since we have a 0 refcount, perf_mmap_close() will skip
3964 * over us; possibly making our ring_buffer_put() the last.
3966 mutex_lock(&event
->mmap_mutex
);
3967 ring_buffer_attach(event
, NULL
);
3968 mutex_unlock(&event
->mmap_mutex
);
3971 if (is_cgroup_event(event
))
3972 perf_detach_cgroup(event
);
3974 if (!event
->parent
) {
3975 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3976 put_callchain_buffers();
3979 perf_event_free_bpf_prog(event
);
3980 perf_addr_filters_splice(event
, NULL
);
3981 kfree(event
->addr_filters_offs
);
3984 event
->destroy(event
);
3987 put_ctx(event
->ctx
);
3989 exclusive_event_destroy(event
);
3990 module_put(event
->pmu
->module
);
3992 call_rcu(&event
->rcu_head
, free_event_rcu
);
3996 * Used to free events which have a known refcount of 1, such as in error paths
3997 * where the event isn't exposed yet and inherited events.
3999 static void free_event(struct perf_event
*event
)
4001 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4002 "unexpected event refcount: %ld; ptr=%p\n",
4003 atomic_long_read(&event
->refcount
), event
)) {
4004 /* leak to avoid use-after-free */
4012 * Remove user event from the owner task.
4014 static void perf_remove_from_owner(struct perf_event
*event
)
4016 struct task_struct
*owner
;
4020 * Matches the smp_store_release() in perf_event_exit_task(). If we
4021 * observe !owner it means the list deletion is complete and we can
4022 * indeed free this event, otherwise we need to serialize on
4023 * owner->perf_event_mutex.
4025 owner
= lockless_dereference(event
->owner
);
4028 * Since delayed_put_task_struct() also drops the last
4029 * task reference we can safely take a new reference
4030 * while holding the rcu_read_lock().
4032 get_task_struct(owner
);
4038 * If we're here through perf_event_exit_task() we're already
4039 * holding ctx->mutex which would be an inversion wrt. the
4040 * normal lock order.
4042 * However we can safely take this lock because its the child
4045 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4048 * We have to re-check the event->owner field, if it is cleared
4049 * we raced with perf_event_exit_task(), acquiring the mutex
4050 * ensured they're done, and we can proceed with freeing the
4054 list_del_init(&event
->owner_entry
);
4055 smp_store_release(&event
->owner
, NULL
);
4057 mutex_unlock(&owner
->perf_event_mutex
);
4058 put_task_struct(owner
);
4062 static void put_event(struct perf_event
*event
)
4064 if (!atomic_long_dec_and_test(&event
->refcount
))
4071 * Kill an event dead; while event:refcount will preserve the event
4072 * object, it will not preserve its functionality. Once the last 'user'
4073 * gives up the object, we'll destroy the thing.
4075 int perf_event_release_kernel(struct perf_event
*event
)
4077 struct perf_event_context
*ctx
= event
->ctx
;
4078 struct perf_event
*child
, *tmp
;
4081 * If we got here through err_file: fput(event_file); we will not have
4082 * attached to a context yet.
4085 WARN_ON_ONCE(event
->attach_state
&
4086 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4090 if (!is_kernel_event(event
))
4091 perf_remove_from_owner(event
);
4093 ctx
= perf_event_ctx_lock(event
);
4094 WARN_ON_ONCE(ctx
->parent_ctx
);
4095 perf_remove_from_context(event
, DETACH_GROUP
);
4097 raw_spin_lock_irq(&ctx
->lock
);
4099 * Mark this even as STATE_DEAD, there is no external reference to it
4102 * Anybody acquiring event->child_mutex after the below loop _must_
4103 * also see this, most importantly inherit_event() which will avoid
4104 * placing more children on the list.
4106 * Thus this guarantees that we will in fact observe and kill _ALL_
4109 event
->state
= PERF_EVENT_STATE_DEAD
;
4110 raw_spin_unlock_irq(&ctx
->lock
);
4112 perf_event_ctx_unlock(event
, ctx
);
4115 mutex_lock(&event
->child_mutex
);
4116 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4119 * Cannot change, child events are not migrated, see the
4120 * comment with perf_event_ctx_lock_nested().
4122 ctx
= lockless_dereference(child
->ctx
);
4124 * Since child_mutex nests inside ctx::mutex, we must jump
4125 * through hoops. We start by grabbing a reference on the ctx.
4127 * Since the event cannot get freed while we hold the
4128 * child_mutex, the context must also exist and have a !0
4134 * Now that we have a ctx ref, we can drop child_mutex, and
4135 * acquire ctx::mutex without fear of it going away. Then we
4136 * can re-acquire child_mutex.
4138 mutex_unlock(&event
->child_mutex
);
4139 mutex_lock(&ctx
->mutex
);
4140 mutex_lock(&event
->child_mutex
);
4143 * Now that we hold ctx::mutex and child_mutex, revalidate our
4144 * state, if child is still the first entry, it didn't get freed
4145 * and we can continue doing so.
4147 tmp
= list_first_entry_or_null(&event
->child_list
,
4148 struct perf_event
, child_list
);
4150 perf_remove_from_context(child
, DETACH_GROUP
);
4151 list_del(&child
->child_list
);
4154 * This matches the refcount bump in inherit_event();
4155 * this can't be the last reference.
4160 mutex_unlock(&event
->child_mutex
);
4161 mutex_unlock(&ctx
->mutex
);
4165 mutex_unlock(&event
->child_mutex
);
4168 put_event(event
); /* Must be the 'last' reference */
4171 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4174 * Called when the last reference to the file is gone.
4176 static int perf_release(struct inode
*inode
, struct file
*file
)
4178 perf_event_release_kernel(file
->private_data
);
4182 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4184 struct perf_event
*child
;
4190 mutex_lock(&event
->child_mutex
);
4192 (void)perf_event_read(event
, false);
4193 total
+= perf_event_count(event
);
4195 *enabled
+= event
->total_time_enabled
+
4196 atomic64_read(&event
->child_total_time_enabled
);
4197 *running
+= event
->total_time_running
+
4198 atomic64_read(&event
->child_total_time_running
);
4200 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4201 (void)perf_event_read(child
, false);
4202 total
+= perf_event_count(child
);
4203 *enabled
+= child
->total_time_enabled
;
4204 *running
+= child
->total_time_running
;
4206 mutex_unlock(&event
->child_mutex
);
4210 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4212 static int __perf_read_group_add(struct perf_event
*leader
,
4213 u64 read_format
, u64
*values
)
4215 struct perf_event
*sub
;
4216 int n
= 1; /* skip @nr */
4219 ret
= perf_event_read(leader
, true);
4224 * Since we co-schedule groups, {enabled,running} times of siblings
4225 * will be identical to those of the leader, so we only publish one
4228 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4229 values
[n
++] += leader
->total_time_enabled
+
4230 atomic64_read(&leader
->child_total_time_enabled
);
4233 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4234 values
[n
++] += leader
->total_time_running
+
4235 atomic64_read(&leader
->child_total_time_running
);
4239 * Write {count,id} tuples for every sibling.
4241 values
[n
++] += perf_event_count(leader
);
4242 if (read_format
& PERF_FORMAT_ID
)
4243 values
[n
++] = primary_event_id(leader
);
4245 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4246 values
[n
++] += perf_event_count(sub
);
4247 if (read_format
& PERF_FORMAT_ID
)
4248 values
[n
++] = primary_event_id(sub
);
4254 static int perf_read_group(struct perf_event
*event
,
4255 u64 read_format
, char __user
*buf
)
4257 struct perf_event
*leader
= event
->group_leader
, *child
;
4258 struct perf_event_context
*ctx
= leader
->ctx
;
4262 lockdep_assert_held(&ctx
->mutex
);
4264 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4268 values
[0] = 1 + leader
->nr_siblings
;
4271 * By locking the child_mutex of the leader we effectively
4272 * lock the child list of all siblings.. XXX explain how.
4274 mutex_lock(&leader
->child_mutex
);
4276 ret
= __perf_read_group_add(leader
, read_format
, values
);
4280 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4281 ret
= __perf_read_group_add(child
, read_format
, values
);
4286 mutex_unlock(&leader
->child_mutex
);
4288 ret
= event
->read_size
;
4289 if (copy_to_user(buf
, values
, event
->read_size
))
4294 mutex_unlock(&leader
->child_mutex
);
4300 static int perf_read_one(struct perf_event
*event
,
4301 u64 read_format
, char __user
*buf
)
4303 u64 enabled
, running
;
4307 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4308 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4309 values
[n
++] = enabled
;
4310 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4311 values
[n
++] = running
;
4312 if (read_format
& PERF_FORMAT_ID
)
4313 values
[n
++] = primary_event_id(event
);
4315 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4318 return n
* sizeof(u64
);
4321 static bool is_event_hup(struct perf_event
*event
)
4325 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4328 mutex_lock(&event
->child_mutex
);
4329 no_children
= list_empty(&event
->child_list
);
4330 mutex_unlock(&event
->child_mutex
);
4335 * Read the performance event - simple non blocking version for now
4338 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4340 u64 read_format
= event
->attr
.read_format
;
4344 * Return end-of-file for a read on a event that is in
4345 * error state (i.e. because it was pinned but it couldn't be
4346 * scheduled on to the CPU at some point).
4348 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4351 if (count
< event
->read_size
)
4354 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4355 if (read_format
& PERF_FORMAT_GROUP
)
4356 ret
= perf_read_group(event
, read_format
, buf
);
4358 ret
= perf_read_one(event
, read_format
, buf
);
4364 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4366 struct perf_event
*event
= file
->private_data
;
4367 struct perf_event_context
*ctx
;
4370 ctx
= perf_event_ctx_lock(event
);
4371 ret
= __perf_read(event
, buf
, count
);
4372 perf_event_ctx_unlock(event
, ctx
);
4377 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4379 struct perf_event
*event
= file
->private_data
;
4380 struct ring_buffer
*rb
;
4381 unsigned int events
= POLLHUP
;
4383 poll_wait(file
, &event
->waitq
, wait
);
4385 if (is_event_hup(event
))
4389 * Pin the event->rb by taking event->mmap_mutex; otherwise
4390 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4392 mutex_lock(&event
->mmap_mutex
);
4395 events
= atomic_xchg(&rb
->poll
, 0);
4396 mutex_unlock(&event
->mmap_mutex
);
4400 static void _perf_event_reset(struct perf_event
*event
)
4402 (void)perf_event_read(event
, false);
4403 local64_set(&event
->count
, 0);
4404 perf_event_update_userpage(event
);
4408 * Holding the top-level event's child_mutex means that any
4409 * descendant process that has inherited this event will block
4410 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4411 * task existence requirements of perf_event_enable/disable.
4413 static void perf_event_for_each_child(struct perf_event
*event
,
4414 void (*func
)(struct perf_event
*))
4416 struct perf_event
*child
;
4418 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4420 mutex_lock(&event
->child_mutex
);
4422 list_for_each_entry(child
, &event
->child_list
, child_list
)
4424 mutex_unlock(&event
->child_mutex
);
4427 static void perf_event_for_each(struct perf_event
*event
,
4428 void (*func
)(struct perf_event
*))
4430 struct perf_event_context
*ctx
= event
->ctx
;
4431 struct perf_event
*sibling
;
4433 lockdep_assert_held(&ctx
->mutex
);
4435 event
= event
->group_leader
;
4437 perf_event_for_each_child(event
, func
);
4438 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4439 perf_event_for_each_child(sibling
, func
);
4442 static void __perf_event_period(struct perf_event
*event
,
4443 struct perf_cpu_context
*cpuctx
,
4444 struct perf_event_context
*ctx
,
4447 u64 value
= *((u64
*)info
);
4450 if (event
->attr
.freq
) {
4451 event
->attr
.sample_freq
= value
;
4453 event
->attr
.sample_period
= value
;
4454 event
->hw
.sample_period
= value
;
4457 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4459 perf_pmu_disable(ctx
->pmu
);
4461 * We could be throttled; unthrottle now to avoid the tick
4462 * trying to unthrottle while we already re-started the event.
4464 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4465 event
->hw
.interrupts
= 0;
4466 perf_log_throttle(event
, 1);
4468 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4471 local64_set(&event
->hw
.period_left
, 0);
4474 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4475 perf_pmu_enable(ctx
->pmu
);
4479 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4483 if (!is_sampling_event(event
))
4486 if (copy_from_user(&value
, arg
, sizeof(value
)))
4492 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4495 event_function_call(event
, __perf_event_period
, &value
);
4500 static const struct file_operations perf_fops
;
4502 static inline int perf_fget_light(int fd
, struct fd
*p
)
4504 struct fd f
= fdget(fd
);
4508 if (f
.file
->f_op
!= &perf_fops
) {
4516 static int perf_event_set_output(struct perf_event
*event
,
4517 struct perf_event
*output_event
);
4518 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4519 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4521 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4523 void (*func
)(struct perf_event
*);
4527 case PERF_EVENT_IOC_ENABLE
:
4528 func
= _perf_event_enable
;
4530 case PERF_EVENT_IOC_DISABLE
:
4531 func
= _perf_event_disable
;
4533 case PERF_EVENT_IOC_RESET
:
4534 func
= _perf_event_reset
;
4537 case PERF_EVENT_IOC_REFRESH
:
4538 return _perf_event_refresh(event
, arg
);
4540 case PERF_EVENT_IOC_PERIOD
:
4541 return perf_event_period(event
, (u64 __user
*)arg
);
4543 case PERF_EVENT_IOC_ID
:
4545 u64 id
= primary_event_id(event
);
4547 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4552 case PERF_EVENT_IOC_SET_OUTPUT
:
4556 struct perf_event
*output_event
;
4558 ret
= perf_fget_light(arg
, &output
);
4561 output_event
= output
.file
->private_data
;
4562 ret
= perf_event_set_output(event
, output_event
);
4565 ret
= perf_event_set_output(event
, NULL
);
4570 case PERF_EVENT_IOC_SET_FILTER
:
4571 return perf_event_set_filter(event
, (void __user
*)arg
);
4573 case PERF_EVENT_IOC_SET_BPF
:
4574 return perf_event_set_bpf_prog(event
, arg
);
4576 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4577 struct ring_buffer
*rb
;
4580 rb
= rcu_dereference(event
->rb
);
4581 if (!rb
|| !rb
->nr_pages
) {
4585 rb_toggle_paused(rb
, !!arg
);
4593 if (flags
& PERF_IOC_FLAG_GROUP
)
4594 perf_event_for_each(event
, func
);
4596 perf_event_for_each_child(event
, func
);
4601 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4603 struct perf_event
*event
= file
->private_data
;
4604 struct perf_event_context
*ctx
;
4607 ctx
= perf_event_ctx_lock(event
);
4608 ret
= _perf_ioctl(event
, cmd
, arg
);
4609 perf_event_ctx_unlock(event
, ctx
);
4614 #ifdef CONFIG_COMPAT
4615 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4618 switch (_IOC_NR(cmd
)) {
4619 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4620 case _IOC_NR(PERF_EVENT_IOC_ID
):
4621 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4622 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4623 cmd
&= ~IOCSIZE_MASK
;
4624 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4628 return perf_ioctl(file
, cmd
, arg
);
4631 # define perf_compat_ioctl NULL
4634 int perf_event_task_enable(void)
4636 struct perf_event_context
*ctx
;
4637 struct perf_event
*event
;
4639 mutex_lock(¤t
->perf_event_mutex
);
4640 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4641 ctx
= perf_event_ctx_lock(event
);
4642 perf_event_for_each_child(event
, _perf_event_enable
);
4643 perf_event_ctx_unlock(event
, ctx
);
4645 mutex_unlock(¤t
->perf_event_mutex
);
4650 int perf_event_task_disable(void)
4652 struct perf_event_context
*ctx
;
4653 struct perf_event
*event
;
4655 mutex_lock(¤t
->perf_event_mutex
);
4656 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4657 ctx
= perf_event_ctx_lock(event
);
4658 perf_event_for_each_child(event
, _perf_event_disable
);
4659 perf_event_ctx_unlock(event
, ctx
);
4661 mutex_unlock(¤t
->perf_event_mutex
);
4666 static int perf_event_index(struct perf_event
*event
)
4668 if (event
->hw
.state
& PERF_HES_STOPPED
)
4671 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4674 return event
->pmu
->event_idx(event
);
4677 static void calc_timer_values(struct perf_event
*event
,
4684 *now
= perf_clock();
4685 ctx_time
= event
->shadow_ctx_time
+ *now
;
4686 *enabled
= ctx_time
- event
->tstamp_enabled
;
4687 *running
= ctx_time
- event
->tstamp_running
;
4690 static void perf_event_init_userpage(struct perf_event
*event
)
4692 struct perf_event_mmap_page
*userpg
;
4693 struct ring_buffer
*rb
;
4696 rb
= rcu_dereference(event
->rb
);
4700 userpg
= rb
->user_page
;
4702 /* Allow new userspace to detect that bit 0 is deprecated */
4703 userpg
->cap_bit0_is_deprecated
= 1;
4704 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4705 userpg
->data_offset
= PAGE_SIZE
;
4706 userpg
->data_size
= perf_data_size(rb
);
4712 void __weak
arch_perf_update_userpage(
4713 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4718 * Callers need to ensure there can be no nesting of this function, otherwise
4719 * the seqlock logic goes bad. We can not serialize this because the arch
4720 * code calls this from NMI context.
4722 void perf_event_update_userpage(struct perf_event
*event
)
4724 struct perf_event_mmap_page
*userpg
;
4725 struct ring_buffer
*rb
;
4726 u64 enabled
, running
, now
;
4729 rb
= rcu_dereference(event
->rb
);
4734 * compute total_time_enabled, total_time_running
4735 * based on snapshot values taken when the event
4736 * was last scheduled in.
4738 * we cannot simply called update_context_time()
4739 * because of locking issue as we can be called in
4742 calc_timer_values(event
, &now
, &enabled
, &running
);
4744 userpg
= rb
->user_page
;
4746 * Disable preemption so as to not let the corresponding user-space
4747 * spin too long if we get preempted.
4752 userpg
->index
= perf_event_index(event
);
4753 userpg
->offset
= perf_event_count(event
);
4755 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4757 userpg
->time_enabled
= enabled
+
4758 atomic64_read(&event
->child_total_time_enabled
);
4760 userpg
->time_running
= running
+
4761 atomic64_read(&event
->child_total_time_running
);
4763 arch_perf_update_userpage(event
, userpg
, now
);
4772 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4774 struct perf_event
*event
= vma
->vm_file
->private_data
;
4775 struct ring_buffer
*rb
;
4776 int ret
= VM_FAULT_SIGBUS
;
4778 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4779 if (vmf
->pgoff
== 0)
4785 rb
= rcu_dereference(event
->rb
);
4789 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4792 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4796 get_page(vmf
->page
);
4797 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4798 vmf
->page
->index
= vmf
->pgoff
;
4807 static void ring_buffer_attach(struct perf_event
*event
,
4808 struct ring_buffer
*rb
)
4810 struct ring_buffer
*old_rb
= NULL
;
4811 unsigned long flags
;
4815 * Should be impossible, we set this when removing
4816 * event->rb_entry and wait/clear when adding event->rb_entry.
4818 WARN_ON_ONCE(event
->rcu_pending
);
4821 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4822 list_del_rcu(&event
->rb_entry
);
4823 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4825 event
->rcu_batches
= get_state_synchronize_rcu();
4826 event
->rcu_pending
= 1;
4830 if (event
->rcu_pending
) {
4831 cond_synchronize_rcu(event
->rcu_batches
);
4832 event
->rcu_pending
= 0;
4835 spin_lock_irqsave(&rb
->event_lock
, flags
);
4836 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4837 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4840 rcu_assign_pointer(event
->rb
, rb
);
4843 ring_buffer_put(old_rb
);
4845 * Since we detached before setting the new rb, so that we
4846 * could attach the new rb, we could have missed a wakeup.
4849 wake_up_all(&event
->waitq
);
4853 static void ring_buffer_wakeup(struct perf_event
*event
)
4855 struct ring_buffer
*rb
;
4858 rb
= rcu_dereference(event
->rb
);
4860 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4861 wake_up_all(&event
->waitq
);
4866 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4868 struct ring_buffer
*rb
;
4871 rb
= rcu_dereference(event
->rb
);
4873 if (!atomic_inc_not_zero(&rb
->refcount
))
4881 void ring_buffer_put(struct ring_buffer
*rb
)
4883 if (!atomic_dec_and_test(&rb
->refcount
))
4886 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4888 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4891 static void perf_mmap_open(struct vm_area_struct
*vma
)
4893 struct perf_event
*event
= vma
->vm_file
->private_data
;
4895 atomic_inc(&event
->mmap_count
);
4896 atomic_inc(&event
->rb
->mmap_count
);
4899 atomic_inc(&event
->rb
->aux_mmap_count
);
4901 if (event
->pmu
->event_mapped
)
4902 event
->pmu
->event_mapped(event
);
4905 static void perf_pmu_output_stop(struct perf_event
*event
);
4908 * A buffer can be mmap()ed multiple times; either directly through the same
4909 * event, or through other events by use of perf_event_set_output().
4911 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4912 * the buffer here, where we still have a VM context. This means we need
4913 * to detach all events redirecting to us.
4915 static void perf_mmap_close(struct vm_area_struct
*vma
)
4917 struct perf_event
*event
= vma
->vm_file
->private_data
;
4919 struct ring_buffer
*rb
= ring_buffer_get(event
);
4920 struct user_struct
*mmap_user
= rb
->mmap_user
;
4921 int mmap_locked
= rb
->mmap_locked
;
4922 unsigned long size
= perf_data_size(rb
);
4924 if (event
->pmu
->event_unmapped
)
4925 event
->pmu
->event_unmapped(event
);
4928 * rb->aux_mmap_count will always drop before rb->mmap_count and
4929 * event->mmap_count, so it is ok to use event->mmap_mutex to
4930 * serialize with perf_mmap here.
4932 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4933 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4935 * Stop all AUX events that are writing to this buffer,
4936 * so that we can free its AUX pages and corresponding PMU
4937 * data. Note that after rb::aux_mmap_count dropped to zero,
4938 * they won't start any more (see perf_aux_output_begin()).
4940 perf_pmu_output_stop(event
);
4942 /* now it's safe to free the pages */
4943 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4944 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4946 /* this has to be the last one */
4948 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
4950 mutex_unlock(&event
->mmap_mutex
);
4953 atomic_dec(&rb
->mmap_count
);
4955 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4958 ring_buffer_attach(event
, NULL
);
4959 mutex_unlock(&event
->mmap_mutex
);
4961 /* If there's still other mmap()s of this buffer, we're done. */
4962 if (atomic_read(&rb
->mmap_count
))
4966 * No other mmap()s, detach from all other events that might redirect
4967 * into the now unreachable buffer. Somewhat complicated by the
4968 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4972 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4973 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4975 * This event is en-route to free_event() which will
4976 * detach it and remove it from the list.
4982 mutex_lock(&event
->mmap_mutex
);
4984 * Check we didn't race with perf_event_set_output() which can
4985 * swizzle the rb from under us while we were waiting to
4986 * acquire mmap_mutex.
4988 * If we find a different rb; ignore this event, a next
4989 * iteration will no longer find it on the list. We have to
4990 * still restart the iteration to make sure we're not now
4991 * iterating the wrong list.
4993 if (event
->rb
== rb
)
4994 ring_buffer_attach(event
, NULL
);
4996 mutex_unlock(&event
->mmap_mutex
);
5000 * Restart the iteration; either we're on the wrong list or
5001 * destroyed its integrity by doing a deletion.
5008 * It could be there's still a few 0-ref events on the list; they'll
5009 * get cleaned up by free_event() -- they'll also still have their
5010 * ref on the rb and will free it whenever they are done with it.
5012 * Aside from that, this buffer is 'fully' detached and unmapped,
5013 * undo the VM accounting.
5016 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5017 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5018 free_uid(mmap_user
);
5021 ring_buffer_put(rb
); /* could be last */
5024 static const struct vm_operations_struct perf_mmap_vmops
= {
5025 .open
= perf_mmap_open
,
5026 .close
= perf_mmap_close
, /* non mergable */
5027 .fault
= perf_mmap_fault
,
5028 .page_mkwrite
= perf_mmap_fault
,
5031 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5033 struct perf_event
*event
= file
->private_data
;
5034 unsigned long user_locked
, user_lock_limit
;
5035 struct user_struct
*user
= current_user();
5036 unsigned long locked
, lock_limit
;
5037 struct ring_buffer
*rb
= NULL
;
5038 unsigned long vma_size
;
5039 unsigned long nr_pages
;
5040 long user_extra
= 0, extra
= 0;
5041 int ret
= 0, flags
= 0;
5044 * Don't allow mmap() of inherited per-task counters. This would
5045 * create a performance issue due to all children writing to the
5048 if (event
->cpu
== -1 && event
->attr
.inherit
)
5051 if (!(vma
->vm_flags
& VM_SHARED
))
5054 vma_size
= vma
->vm_end
- vma
->vm_start
;
5056 if (vma
->vm_pgoff
== 0) {
5057 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5060 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5061 * mapped, all subsequent mappings should have the same size
5062 * and offset. Must be above the normal perf buffer.
5064 u64 aux_offset
, aux_size
;
5069 nr_pages
= vma_size
/ PAGE_SIZE
;
5071 mutex_lock(&event
->mmap_mutex
);
5078 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
5079 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
5081 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5084 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5087 /* already mapped with a different offset */
5088 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5091 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5094 /* already mapped with a different size */
5095 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5098 if (!is_power_of_2(nr_pages
))
5101 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5104 if (rb_has_aux(rb
)) {
5105 atomic_inc(&rb
->aux_mmap_count
);
5110 atomic_set(&rb
->aux_mmap_count
, 1);
5111 user_extra
= nr_pages
;
5117 * If we have rb pages ensure they're a power-of-two number, so we
5118 * can do bitmasks instead of modulo.
5120 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5123 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5126 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5128 mutex_lock(&event
->mmap_mutex
);
5130 if (event
->rb
->nr_pages
!= nr_pages
) {
5135 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5137 * Raced against perf_mmap_close() through
5138 * perf_event_set_output(). Try again, hope for better
5141 mutex_unlock(&event
->mmap_mutex
);
5148 user_extra
= nr_pages
+ 1;
5151 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5154 * Increase the limit linearly with more CPUs:
5156 user_lock_limit
*= num_online_cpus();
5158 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5160 if (user_locked
> user_lock_limit
)
5161 extra
= user_locked
- user_lock_limit
;
5163 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5164 lock_limit
>>= PAGE_SHIFT
;
5165 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5167 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5168 !capable(CAP_IPC_LOCK
)) {
5173 WARN_ON(!rb
&& event
->rb
);
5175 if (vma
->vm_flags
& VM_WRITE
)
5176 flags
|= RING_BUFFER_WRITABLE
;
5179 rb
= rb_alloc(nr_pages
,
5180 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5188 atomic_set(&rb
->mmap_count
, 1);
5189 rb
->mmap_user
= get_current_user();
5190 rb
->mmap_locked
= extra
;
5192 ring_buffer_attach(event
, rb
);
5194 perf_event_init_userpage(event
);
5195 perf_event_update_userpage(event
);
5197 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5198 event
->attr
.aux_watermark
, flags
);
5200 rb
->aux_mmap_locked
= extra
;
5205 atomic_long_add(user_extra
, &user
->locked_vm
);
5206 vma
->vm_mm
->pinned_vm
+= extra
;
5208 atomic_inc(&event
->mmap_count
);
5210 atomic_dec(&rb
->mmap_count
);
5213 mutex_unlock(&event
->mmap_mutex
);
5216 * Since pinned accounting is per vm we cannot allow fork() to copy our
5219 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5220 vma
->vm_ops
= &perf_mmap_vmops
;
5222 if (event
->pmu
->event_mapped
)
5223 event
->pmu
->event_mapped(event
);
5228 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5230 struct inode
*inode
= file_inode(filp
);
5231 struct perf_event
*event
= filp
->private_data
;
5235 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5236 inode_unlock(inode
);
5244 static const struct file_operations perf_fops
= {
5245 .llseek
= no_llseek
,
5246 .release
= perf_release
,
5249 .unlocked_ioctl
= perf_ioctl
,
5250 .compat_ioctl
= perf_compat_ioctl
,
5252 .fasync
= perf_fasync
,
5258 * If there's data, ensure we set the poll() state and publish everything
5259 * to user-space before waking everybody up.
5262 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5264 /* only the parent has fasync state */
5266 event
= event
->parent
;
5267 return &event
->fasync
;
5270 void perf_event_wakeup(struct perf_event
*event
)
5272 ring_buffer_wakeup(event
);
5274 if (event
->pending_kill
) {
5275 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5276 event
->pending_kill
= 0;
5280 static void perf_pending_event(struct irq_work
*entry
)
5282 struct perf_event
*event
= container_of(entry
,
5283 struct perf_event
, pending
);
5286 rctx
= perf_swevent_get_recursion_context();
5288 * If we 'fail' here, that's OK, it means recursion is already disabled
5289 * and we won't recurse 'further'.
5292 if (event
->pending_disable
) {
5293 event
->pending_disable
= 0;
5294 perf_event_disable_local(event
);
5297 if (event
->pending_wakeup
) {
5298 event
->pending_wakeup
= 0;
5299 perf_event_wakeup(event
);
5303 perf_swevent_put_recursion_context(rctx
);
5307 * We assume there is only KVM supporting the callbacks.
5308 * Later on, we might change it to a list if there is
5309 * another virtualization implementation supporting the callbacks.
5311 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5313 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5315 perf_guest_cbs
= cbs
;
5318 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5320 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5322 perf_guest_cbs
= NULL
;
5325 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5328 perf_output_sample_regs(struct perf_output_handle
*handle
,
5329 struct pt_regs
*regs
, u64 mask
)
5333 for_each_set_bit(bit
, (const unsigned long *) &mask
,
5334 sizeof(mask
) * BITS_PER_BYTE
) {
5337 val
= perf_reg_value(regs
, bit
);
5338 perf_output_put(handle
, val
);
5342 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5343 struct pt_regs
*regs
,
5344 struct pt_regs
*regs_user_copy
)
5346 if (user_mode(regs
)) {
5347 regs_user
->abi
= perf_reg_abi(current
);
5348 regs_user
->regs
= regs
;
5349 } else if (current
->mm
) {
5350 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5352 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5353 regs_user
->regs
= NULL
;
5357 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5358 struct pt_regs
*regs
)
5360 regs_intr
->regs
= regs
;
5361 regs_intr
->abi
= perf_reg_abi(current
);
5366 * Get remaining task size from user stack pointer.
5368 * It'd be better to take stack vma map and limit this more
5369 * precisly, but there's no way to get it safely under interrupt,
5370 * so using TASK_SIZE as limit.
5372 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5374 unsigned long addr
= perf_user_stack_pointer(regs
);
5376 if (!addr
|| addr
>= TASK_SIZE
)
5379 return TASK_SIZE
- addr
;
5383 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5384 struct pt_regs
*regs
)
5388 /* No regs, no stack pointer, no dump. */
5393 * Check if we fit in with the requested stack size into the:
5395 * If we don't, we limit the size to the TASK_SIZE.
5397 * - remaining sample size
5398 * If we don't, we customize the stack size to
5399 * fit in to the remaining sample size.
5402 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5403 stack_size
= min(stack_size
, (u16
) task_size
);
5405 /* Current header size plus static size and dynamic size. */
5406 header_size
+= 2 * sizeof(u64
);
5408 /* Do we fit in with the current stack dump size? */
5409 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5411 * If we overflow the maximum size for the sample,
5412 * we customize the stack dump size to fit in.
5414 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5415 stack_size
= round_up(stack_size
, sizeof(u64
));
5422 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5423 struct pt_regs
*regs
)
5425 /* Case of a kernel thread, nothing to dump */
5428 perf_output_put(handle
, size
);
5437 * - the size requested by user or the best one we can fit
5438 * in to the sample max size
5440 * - user stack dump data
5442 * - the actual dumped size
5446 perf_output_put(handle
, dump_size
);
5449 sp
= perf_user_stack_pointer(regs
);
5450 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5451 dyn_size
= dump_size
- rem
;
5453 perf_output_skip(handle
, rem
);
5456 perf_output_put(handle
, dyn_size
);
5460 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5461 struct perf_sample_data
*data
,
5462 struct perf_event
*event
)
5464 u64 sample_type
= event
->attr
.sample_type
;
5466 data
->type
= sample_type
;
5467 header
->size
+= event
->id_header_size
;
5469 if (sample_type
& PERF_SAMPLE_TID
) {
5470 /* namespace issues */
5471 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5472 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5475 if (sample_type
& PERF_SAMPLE_TIME
)
5476 data
->time
= perf_event_clock(event
);
5478 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5479 data
->id
= primary_event_id(event
);
5481 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5482 data
->stream_id
= event
->id
;
5484 if (sample_type
& PERF_SAMPLE_CPU
) {
5485 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5486 data
->cpu_entry
.reserved
= 0;
5490 void perf_event_header__init_id(struct perf_event_header
*header
,
5491 struct perf_sample_data
*data
,
5492 struct perf_event
*event
)
5494 if (event
->attr
.sample_id_all
)
5495 __perf_event_header__init_id(header
, data
, event
);
5498 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5499 struct perf_sample_data
*data
)
5501 u64 sample_type
= data
->type
;
5503 if (sample_type
& PERF_SAMPLE_TID
)
5504 perf_output_put(handle
, data
->tid_entry
);
5506 if (sample_type
& PERF_SAMPLE_TIME
)
5507 perf_output_put(handle
, data
->time
);
5509 if (sample_type
& PERF_SAMPLE_ID
)
5510 perf_output_put(handle
, data
->id
);
5512 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5513 perf_output_put(handle
, data
->stream_id
);
5515 if (sample_type
& PERF_SAMPLE_CPU
)
5516 perf_output_put(handle
, data
->cpu_entry
);
5518 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5519 perf_output_put(handle
, data
->id
);
5522 void perf_event__output_id_sample(struct perf_event
*event
,
5523 struct perf_output_handle
*handle
,
5524 struct perf_sample_data
*sample
)
5526 if (event
->attr
.sample_id_all
)
5527 __perf_event__output_id_sample(handle
, sample
);
5530 static void perf_output_read_one(struct perf_output_handle
*handle
,
5531 struct perf_event
*event
,
5532 u64 enabled
, u64 running
)
5534 u64 read_format
= event
->attr
.read_format
;
5538 values
[n
++] = perf_event_count(event
);
5539 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5540 values
[n
++] = enabled
+
5541 atomic64_read(&event
->child_total_time_enabled
);
5543 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5544 values
[n
++] = running
+
5545 atomic64_read(&event
->child_total_time_running
);
5547 if (read_format
& PERF_FORMAT_ID
)
5548 values
[n
++] = primary_event_id(event
);
5550 __output_copy(handle
, values
, n
* sizeof(u64
));
5554 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5556 static void perf_output_read_group(struct perf_output_handle
*handle
,
5557 struct perf_event
*event
,
5558 u64 enabled
, u64 running
)
5560 struct perf_event
*leader
= event
->group_leader
, *sub
;
5561 u64 read_format
= event
->attr
.read_format
;
5565 values
[n
++] = 1 + leader
->nr_siblings
;
5567 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5568 values
[n
++] = enabled
;
5570 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5571 values
[n
++] = running
;
5573 if (leader
!= event
)
5574 leader
->pmu
->read(leader
);
5576 values
[n
++] = perf_event_count(leader
);
5577 if (read_format
& PERF_FORMAT_ID
)
5578 values
[n
++] = primary_event_id(leader
);
5580 __output_copy(handle
, values
, n
* sizeof(u64
));
5582 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5585 if ((sub
!= event
) &&
5586 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5587 sub
->pmu
->read(sub
);
5589 values
[n
++] = perf_event_count(sub
);
5590 if (read_format
& PERF_FORMAT_ID
)
5591 values
[n
++] = primary_event_id(sub
);
5593 __output_copy(handle
, values
, n
* sizeof(u64
));
5597 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5598 PERF_FORMAT_TOTAL_TIME_RUNNING)
5600 static void perf_output_read(struct perf_output_handle
*handle
,
5601 struct perf_event
*event
)
5603 u64 enabled
= 0, running
= 0, now
;
5604 u64 read_format
= event
->attr
.read_format
;
5607 * compute total_time_enabled, total_time_running
5608 * based on snapshot values taken when the event
5609 * was last scheduled in.
5611 * we cannot simply called update_context_time()
5612 * because of locking issue as we are called in
5615 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5616 calc_timer_values(event
, &now
, &enabled
, &running
);
5618 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5619 perf_output_read_group(handle
, event
, enabled
, running
);
5621 perf_output_read_one(handle
, event
, enabled
, running
);
5624 void perf_output_sample(struct perf_output_handle
*handle
,
5625 struct perf_event_header
*header
,
5626 struct perf_sample_data
*data
,
5627 struct perf_event
*event
)
5629 u64 sample_type
= data
->type
;
5631 perf_output_put(handle
, *header
);
5633 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5634 perf_output_put(handle
, data
->id
);
5636 if (sample_type
& PERF_SAMPLE_IP
)
5637 perf_output_put(handle
, data
->ip
);
5639 if (sample_type
& PERF_SAMPLE_TID
)
5640 perf_output_put(handle
, data
->tid_entry
);
5642 if (sample_type
& PERF_SAMPLE_TIME
)
5643 perf_output_put(handle
, data
->time
);
5645 if (sample_type
& PERF_SAMPLE_ADDR
)
5646 perf_output_put(handle
, data
->addr
);
5648 if (sample_type
& PERF_SAMPLE_ID
)
5649 perf_output_put(handle
, data
->id
);
5651 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5652 perf_output_put(handle
, data
->stream_id
);
5654 if (sample_type
& PERF_SAMPLE_CPU
)
5655 perf_output_put(handle
, data
->cpu_entry
);
5657 if (sample_type
& PERF_SAMPLE_PERIOD
)
5658 perf_output_put(handle
, data
->period
);
5660 if (sample_type
& PERF_SAMPLE_READ
)
5661 perf_output_read(handle
, event
);
5663 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5664 if (data
->callchain
) {
5667 if (data
->callchain
)
5668 size
+= data
->callchain
->nr
;
5670 size
*= sizeof(u64
);
5672 __output_copy(handle
, data
->callchain
, size
);
5675 perf_output_put(handle
, nr
);
5679 if (sample_type
& PERF_SAMPLE_RAW
) {
5680 struct perf_raw_record
*raw
= data
->raw
;
5683 struct perf_raw_frag
*frag
= &raw
->frag
;
5685 perf_output_put(handle
, raw
->size
);
5688 __output_custom(handle
, frag
->copy
,
5689 frag
->data
, frag
->size
);
5691 __output_copy(handle
, frag
->data
,
5694 if (perf_raw_frag_last(frag
))
5699 __output_skip(handle
, NULL
, frag
->pad
);
5705 .size
= sizeof(u32
),
5708 perf_output_put(handle
, raw
);
5712 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5713 if (data
->br_stack
) {
5716 size
= data
->br_stack
->nr
5717 * sizeof(struct perf_branch_entry
);
5719 perf_output_put(handle
, data
->br_stack
->nr
);
5720 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5723 * we always store at least the value of nr
5726 perf_output_put(handle
, nr
);
5730 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5731 u64 abi
= data
->regs_user
.abi
;
5734 * If there are no regs to dump, notice it through
5735 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5737 perf_output_put(handle
, abi
);
5740 u64 mask
= event
->attr
.sample_regs_user
;
5741 perf_output_sample_regs(handle
,
5742 data
->regs_user
.regs
,
5747 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5748 perf_output_sample_ustack(handle
,
5749 data
->stack_user_size
,
5750 data
->regs_user
.regs
);
5753 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5754 perf_output_put(handle
, data
->weight
);
5756 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5757 perf_output_put(handle
, data
->data_src
.val
);
5759 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5760 perf_output_put(handle
, data
->txn
);
5762 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5763 u64 abi
= data
->regs_intr
.abi
;
5765 * If there are no regs to dump, notice it through
5766 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5768 perf_output_put(handle
, abi
);
5771 u64 mask
= event
->attr
.sample_regs_intr
;
5773 perf_output_sample_regs(handle
,
5774 data
->regs_intr
.regs
,
5779 if (!event
->attr
.watermark
) {
5780 int wakeup_events
= event
->attr
.wakeup_events
;
5782 if (wakeup_events
) {
5783 struct ring_buffer
*rb
= handle
->rb
;
5784 int events
= local_inc_return(&rb
->events
);
5786 if (events
>= wakeup_events
) {
5787 local_sub(wakeup_events
, &rb
->events
);
5788 local_inc(&rb
->wakeup
);
5794 void perf_prepare_sample(struct perf_event_header
*header
,
5795 struct perf_sample_data
*data
,
5796 struct perf_event
*event
,
5797 struct pt_regs
*regs
)
5799 u64 sample_type
= event
->attr
.sample_type
;
5801 header
->type
= PERF_RECORD_SAMPLE
;
5802 header
->size
= sizeof(*header
) + event
->header_size
;
5805 header
->misc
|= perf_misc_flags(regs
);
5807 __perf_event_header__init_id(header
, data
, event
);
5809 if (sample_type
& PERF_SAMPLE_IP
)
5810 data
->ip
= perf_instruction_pointer(regs
);
5812 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5815 data
->callchain
= perf_callchain(event
, regs
);
5817 if (data
->callchain
)
5818 size
+= data
->callchain
->nr
;
5820 header
->size
+= size
* sizeof(u64
);
5823 if (sample_type
& PERF_SAMPLE_RAW
) {
5824 struct perf_raw_record
*raw
= data
->raw
;
5828 struct perf_raw_frag
*frag
= &raw
->frag
;
5833 if (perf_raw_frag_last(frag
))
5838 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
5839 raw
->size
= size
- sizeof(u32
);
5840 frag
->pad
= raw
->size
- sum
;
5845 header
->size
+= size
;
5848 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5849 int size
= sizeof(u64
); /* nr */
5850 if (data
->br_stack
) {
5851 size
+= data
->br_stack
->nr
5852 * sizeof(struct perf_branch_entry
);
5854 header
->size
+= size
;
5857 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5858 perf_sample_regs_user(&data
->regs_user
, regs
,
5859 &data
->regs_user_copy
);
5861 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5862 /* regs dump ABI info */
5863 int size
= sizeof(u64
);
5865 if (data
->regs_user
.regs
) {
5866 u64 mask
= event
->attr
.sample_regs_user
;
5867 size
+= hweight64(mask
) * sizeof(u64
);
5870 header
->size
+= size
;
5873 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5875 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5876 * processed as the last one or have additional check added
5877 * in case new sample type is added, because we could eat
5878 * up the rest of the sample size.
5880 u16 stack_size
= event
->attr
.sample_stack_user
;
5881 u16 size
= sizeof(u64
);
5883 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5884 data
->regs_user
.regs
);
5887 * If there is something to dump, add space for the dump
5888 * itself and for the field that tells the dynamic size,
5889 * which is how many have been actually dumped.
5892 size
+= sizeof(u64
) + stack_size
;
5894 data
->stack_user_size
= stack_size
;
5895 header
->size
+= size
;
5898 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5899 /* regs dump ABI info */
5900 int size
= sizeof(u64
);
5902 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5904 if (data
->regs_intr
.regs
) {
5905 u64 mask
= event
->attr
.sample_regs_intr
;
5907 size
+= hweight64(mask
) * sizeof(u64
);
5910 header
->size
+= size
;
5914 static void __always_inline
5915 __perf_event_output(struct perf_event
*event
,
5916 struct perf_sample_data
*data
,
5917 struct pt_regs
*regs
,
5918 int (*output_begin
)(struct perf_output_handle
*,
5919 struct perf_event
*,
5922 struct perf_output_handle handle
;
5923 struct perf_event_header header
;
5925 /* protect the callchain buffers */
5928 perf_prepare_sample(&header
, data
, event
, regs
);
5930 if (output_begin(&handle
, event
, header
.size
))
5933 perf_output_sample(&handle
, &header
, data
, event
);
5935 perf_output_end(&handle
);
5942 perf_event_output_forward(struct perf_event
*event
,
5943 struct perf_sample_data
*data
,
5944 struct pt_regs
*regs
)
5946 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
5950 perf_event_output_backward(struct perf_event
*event
,
5951 struct perf_sample_data
*data
,
5952 struct pt_regs
*regs
)
5954 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
5958 perf_event_output(struct perf_event
*event
,
5959 struct perf_sample_data
*data
,
5960 struct pt_regs
*regs
)
5962 __perf_event_output(event
, data
, regs
, perf_output_begin
);
5969 struct perf_read_event
{
5970 struct perf_event_header header
;
5977 perf_event_read_event(struct perf_event
*event
,
5978 struct task_struct
*task
)
5980 struct perf_output_handle handle
;
5981 struct perf_sample_data sample
;
5982 struct perf_read_event read_event
= {
5984 .type
= PERF_RECORD_READ
,
5986 .size
= sizeof(read_event
) + event
->read_size
,
5988 .pid
= perf_event_pid(event
, task
),
5989 .tid
= perf_event_tid(event
, task
),
5993 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5994 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5998 perf_output_put(&handle
, read_event
);
5999 perf_output_read(&handle
, event
);
6000 perf_event__output_id_sample(event
, &handle
, &sample
);
6002 perf_output_end(&handle
);
6005 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6008 perf_iterate_ctx(struct perf_event_context
*ctx
,
6009 perf_iterate_f output
,
6010 void *data
, bool all
)
6012 struct perf_event
*event
;
6014 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6016 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6018 if (!event_filter_match(event
))
6022 output(event
, data
);
6026 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6028 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6029 struct perf_event
*event
;
6031 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6033 * Skip events that are not fully formed yet; ensure that
6034 * if we observe event->ctx, both event and ctx will be
6035 * complete enough. See perf_install_in_context().
6037 if (!smp_load_acquire(&event
->ctx
))
6040 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6042 if (!event_filter_match(event
))
6044 output(event
, data
);
6049 * Iterate all events that need to receive side-band events.
6051 * For new callers; ensure that account_pmu_sb_event() includes
6052 * your event, otherwise it might not get delivered.
6055 perf_iterate_sb(perf_iterate_f output
, void *data
,
6056 struct perf_event_context
*task_ctx
)
6058 struct perf_event_context
*ctx
;
6065 * If we have task_ctx != NULL we only notify the task context itself.
6066 * The task_ctx is set only for EXIT events before releasing task
6070 perf_iterate_ctx(task_ctx
, output
, data
, false);
6074 perf_iterate_sb_cpu(output
, data
);
6076 for_each_task_context_nr(ctxn
) {
6077 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6079 perf_iterate_ctx(ctx
, output
, data
, false);
6087 * Clear all file-based filters at exec, they'll have to be
6088 * re-instated when/if these objects are mmapped again.
6090 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6092 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6093 struct perf_addr_filter
*filter
;
6094 unsigned int restart
= 0, count
= 0;
6095 unsigned long flags
;
6097 if (!has_addr_filter(event
))
6100 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6101 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6102 if (filter
->inode
) {
6103 event
->addr_filters_offs
[count
] = 0;
6111 event
->addr_filters_gen
++;
6112 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6115 perf_event_restart(event
);
6118 void perf_event_exec(void)
6120 struct perf_event_context
*ctx
;
6124 for_each_task_context_nr(ctxn
) {
6125 ctx
= current
->perf_event_ctxp
[ctxn
];
6129 perf_event_enable_on_exec(ctxn
);
6131 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6137 struct remote_output
{
6138 struct ring_buffer
*rb
;
6142 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6144 struct perf_event
*parent
= event
->parent
;
6145 struct remote_output
*ro
= data
;
6146 struct ring_buffer
*rb
= ro
->rb
;
6147 struct stop_event_data sd
= {
6151 if (!has_aux(event
))
6158 * In case of inheritance, it will be the parent that links to the
6159 * ring-buffer, but it will be the child that's actually using it:
6161 if (rcu_dereference(parent
->rb
) == rb
)
6162 ro
->err
= __perf_event_stop(&sd
);
6165 static int __perf_pmu_output_stop(void *info
)
6167 struct perf_event
*event
= info
;
6168 struct pmu
*pmu
= event
->pmu
;
6169 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6170 struct remote_output ro
= {
6175 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6176 if (cpuctx
->task_ctx
)
6177 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6184 static void perf_pmu_output_stop(struct perf_event
*event
)
6186 struct perf_event
*iter
;
6191 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6193 * For per-CPU events, we need to make sure that neither they
6194 * nor their children are running; for cpu==-1 events it's
6195 * sufficient to stop the event itself if it's active, since
6196 * it can't have children.
6200 cpu
= READ_ONCE(iter
->oncpu
);
6205 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6206 if (err
== -EAGAIN
) {
6215 * task tracking -- fork/exit
6217 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6220 struct perf_task_event
{
6221 struct task_struct
*task
;
6222 struct perf_event_context
*task_ctx
;
6225 struct perf_event_header header
;
6235 static int perf_event_task_match(struct perf_event
*event
)
6237 return event
->attr
.comm
|| event
->attr
.mmap
||
6238 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6242 static void perf_event_task_output(struct perf_event
*event
,
6245 struct perf_task_event
*task_event
= data
;
6246 struct perf_output_handle handle
;
6247 struct perf_sample_data sample
;
6248 struct task_struct
*task
= task_event
->task
;
6249 int ret
, size
= task_event
->event_id
.header
.size
;
6251 if (!perf_event_task_match(event
))
6254 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6256 ret
= perf_output_begin(&handle
, event
,
6257 task_event
->event_id
.header
.size
);
6261 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6262 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6264 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6265 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6267 task_event
->event_id
.time
= perf_event_clock(event
);
6269 perf_output_put(&handle
, task_event
->event_id
);
6271 perf_event__output_id_sample(event
, &handle
, &sample
);
6273 perf_output_end(&handle
);
6275 task_event
->event_id
.header
.size
= size
;
6278 static void perf_event_task(struct task_struct
*task
,
6279 struct perf_event_context
*task_ctx
,
6282 struct perf_task_event task_event
;
6284 if (!atomic_read(&nr_comm_events
) &&
6285 !atomic_read(&nr_mmap_events
) &&
6286 !atomic_read(&nr_task_events
))
6289 task_event
= (struct perf_task_event
){
6291 .task_ctx
= task_ctx
,
6294 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6296 .size
= sizeof(task_event
.event_id
),
6306 perf_iterate_sb(perf_event_task_output
,
6311 void perf_event_fork(struct task_struct
*task
)
6313 perf_event_task(task
, NULL
, 1);
6320 struct perf_comm_event
{
6321 struct task_struct
*task
;
6326 struct perf_event_header header
;
6333 static int perf_event_comm_match(struct perf_event
*event
)
6335 return event
->attr
.comm
;
6338 static void perf_event_comm_output(struct perf_event
*event
,
6341 struct perf_comm_event
*comm_event
= data
;
6342 struct perf_output_handle handle
;
6343 struct perf_sample_data sample
;
6344 int size
= comm_event
->event_id
.header
.size
;
6347 if (!perf_event_comm_match(event
))
6350 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6351 ret
= perf_output_begin(&handle
, event
,
6352 comm_event
->event_id
.header
.size
);
6357 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6358 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6360 perf_output_put(&handle
, comm_event
->event_id
);
6361 __output_copy(&handle
, comm_event
->comm
,
6362 comm_event
->comm_size
);
6364 perf_event__output_id_sample(event
, &handle
, &sample
);
6366 perf_output_end(&handle
);
6368 comm_event
->event_id
.header
.size
= size
;
6371 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6373 char comm
[TASK_COMM_LEN
];
6376 memset(comm
, 0, sizeof(comm
));
6377 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6378 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6380 comm_event
->comm
= comm
;
6381 comm_event
->comm_size
= size
;
6383 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6385 perf_iterate_sb(perf_event_comm_output
,
6390 void perf_event_comm(struct task_struct
*task
, bool exec
)
6392 struct perf_comm_event comm_event
;
6394 if (!atomic_read(&nr_comm_events
))
6397 comm_event
= (struct perf_comm_event
){
6403 .type
= PERF_RECORD_COMM
,
6404 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6412 perf_event_comm_event(&comm_event
);
6419 struct perf_mmap_event
{
6420 struct vm_area_struct
*vma
;
6422 const char *file_name
;
6430 struct perf_event_header header
;
6440 static int perf_event_mmap_match(struct perf_event
*event
,
6443 struct perf_mmap_event
*mmap_event
= data
;
6444 struct vm_area_struct
*vma
= mmap_event
->vma
;
6445 int executable
= vma
->vm_flags
& VM_EXEC
;
6447 return (!executable
&& event
->attr
.mmap_data
) ||
6448 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6451 static void perf_event_mmap_output(struct perf_event
*event
,
6454 struct perf_mmap_event
*mmap_event
= data
;
6455 struct perf_output_handle handle
;
6456 struct perf_sample_data sample
;
6457 int size
= mmap_event
->event_id
.header
.size
;
6460 if (!perf_event_mmap_match(event
, data
))
6463 if (event
->attr
.mmap2
) {
6464 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6465 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6466 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6467 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6468 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6469 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6470 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6473 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6474 ret
= perf_output_begin(&handle
, event
,
6475 mmap_event
->event_id
.header
.size
);
6479 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6480 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6482 perf_output_put(&handle
, mmap_event
->event_id
);
6484 if (event
->attr
.mmap2
) {
6485 perf_output_put(&handle
, mmap_event
->maj
);
6486 perf_output_put(&handle
, mmap_event
->min
);
6487 perf_output_put(&handle
, mmap_event
->ino
);
6488 perf_output_put(&handle
, mmap_event
->ino_generation
);
6489 perf_output_put(&handle
, mmap_event
->prot
);
6490 perf_output_put(&handle
, mmap_event
->flags
);
6493 __output_copy(&handle
, mmap_event
->file_name
,
6494 mmap_event
->file_size
);
6496 perf_event__output_id_sample(event
, &handle
, &sample
);
6498 perf_output_end(&handle
);
6500 mmap_event
->event_id
.header
.size
= size
;
6503 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6505 struct vm_area_struct
*vma
= mmap_event
->vma
;
6506 struct file
*file
= vma
->vm_file
;
6507 int maj
= 0, min
= 0;
6508 u64 ino
= 0, gen
= 0;
6509 u32 prot
= 0, flags
= 0;
6516 struct inode
*inode
;
6519 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6525 * d_path() works from the end of the rb backwards, so we
6526 * need to add enough zero bytes after the string to handle
6527 * the 64bit alignment we do later.
6529 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6534 inode
= file_inode(vma
->vm_file
);
6535 dev
= inode
->i_sb
->s_dev
;
6537 gen
= inode
->i_generation
;
6541 if (vma
->vm_flags
& VM_READ
)
6543 if (vma
->vm_flags
& VM_WRITE
)
6545 if (vma
->vm_flags
& VM_EXEC
)
6548 if (vma
->vm_flags
& VM_MAYSHARE
)
6551 flags
= MAP_PRIVATE
;
6553 if (vma
->vm_flags
& VM_DENYWRITE
)
6554 flags
|= MAP_DENYWRITE
;
6555 if (vma
->vm_flags
& VM_MAYEXEC
)
6556 flags
|= MAP_EXECUTABLE
;
6557 if (vma
->vm_flags
& VM_LOCKED
)
6558 flags
|= MAP_LOCKED
;
6559 if (vma
->vm_flags
& VM_HUGETLB
)
6560 flags
|= MAP_HUGETLB
;
6564 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6565 name
= (char *) vma
->vm_ops
->name(vma
);
6570 name
= (char *)arch_vma_name(vma
);
6574 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6575 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6579 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6580 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6590 strlcpy(tmp
, name
, sizeof(tmp
));
6594 * Since our buffer works in 8 byte units we need to align our string
6595 * size to a multiple of 8. However, we must guarantee the tail end is
6596 * zero'd out to avoid leaking random bits to userspace.
6598 size
= strlen(name
)+1;
6599 while (!IS_ALIGNED(size
, sizeof(u64
)))
6600 name
[size
++] = '\0';
6602 mmap_event
->file_name
= name
;
6603 mmap_event
->file_size
= size
;
6604 mmap_event
->maj
= maj
;
6605 mmap_event
->min
= min
;
6606 mmap_event
->ino
= ino
;
6607 mmap_event
->ino_generation
= gen
;
6608 mmap_event
->prot
= prot
;
6609 mmap_event
->flags
= flags
;
6611 if (!(vma
->vm_flags
& VM_EXEC
))
6612 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6614 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6616 perf_iterate_sb(perf_event_mmap_output
,
6624 * Check whether inode and address range match filter criteria.
6626 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
6627 struct file
*file
, unsigned long offset
,
6630 if (filter
->inode
!= file
->f_inode
)
6633 if (filter
->offset
> offset
+ size
)
6636 if (filter
->offset
+ filter
->size
< offset
)
6642 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
6644 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6645 struct vm_area_struct
*vma
= data
;
6646 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
6647 struct file
*file
= vma
->vm_file
;
6648 struct perf_addr_filter
*filter
;
6649 unsigned int restart
= 0, count
= 0;
6651 if (!has_addr_filter(event
))
6657 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6658 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6659 if (perf_addr_filter_match(filter
, file
, off
,
6660 vma
->vm_end
- vma
->vm_start
)) {
6661 event
->addr_filters_offs
[count
] = vma
->vm_start
;
6669 event
->addr_filters_gen
++;
6670 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6673 perf_event_restart(event
);
6677 * Adjust all task's events' filters to the new vma
6679 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
6681 struct perf_event_context
*ctx
;
6685 * Data tracing isn't supported yet and as such there is no need
6686 * to keep track of anything that isn't related to executable code:
6688 if (!(vma
->vm_flags
& VM_EXEC
))
6692 for_each_task_context_nr(ctxn
) {
6693 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6697 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
6702 void perf_event_mmap(struct vm_area_struct
*vma
)
6704 struct perf_mmap_event mmap_event
;
6706 if (!atomic_read(&nr_mmap_events
))
6709 mmap_event
= (struct perf_mmap_event
){
6715 .type
= PERF_RECORD_MMAP
,
6716 .misc
= PERF_RECORD_MISC_USER
,
6721 .start
= vma
->vm_start
,
6722 .len
= vma
->vm_end
- vma
->vm_start
,
6723 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6725 /* .maj (attr_mmap2 only) */
6726 /* .min (attr_mmap2 only) */
6727 /* .ino (attr_mmap2 only) */
6728 /* .ino_generation (attr_mmap2 only) */
6729 /* .prot (attr_mmap2 only) */
6730 /* .flags (attr_mmap2 only) */
6733 perf_addr_filters_adjust(vma
);
6734 perf_event_mmap_event(&mmap_event
);
6737 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6738 unsigned long size
, u64 flags
)
6740 struct perf_output_handle handle
;
6741 struct perf_sample_data sample
;
6742 struct perf_aux_event
{
6743 struct perf_event_header header
;
6749 .type
= PERF_RECORD_AUX
,
6751 .size
= sizeof(rec
),
6759 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6760 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6765 perf_output_put(&handle
, rec
);
6766 perf_event__output_id_sample(event
, &handle
, &sample
);
6768 perf_output_end(&handle
);
6772 * Lost/dropped samples logging
6774 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6776 struct perf_output_handle handle
;
6777 struct perf_sample_data sample
;
6781 struct perf_event_header header
;
6783 } lost_samples_event
= {
6785 .type
= PERF_RECORD_LOST_SAMPLES
,
6787 .size
= sizeof(lost_samples_event
),
6792 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6794 ret
= perf_output_begin(&handle
, event
,
6795 lost_samples_event
.header
.size
);
6799 perf_output_put(&handle
, lost_samples_event
);
6800 perf_event__output_id_sample(event
, &handle
, &sample
);
6801 perf_output_end(&handle
);
6805 * context_switch tracking
6808 struct perf_switch_event
{
6809 struct task_struct
*task
;
6810 struct task_struct
*next_prev
;
6813 struct perf_event_header header
;
6819 static int perf_event_switch_match(struct perf_event
*event
)
6821 return event
->attr
.context_switch
;
6824 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6826 struct perf_switch_event
*se
= data
;
6827 struct perf_output_handle handle
;
6828 struct perf_sample_data sample
;
6831 if (!perf_event_switch_match(event
))
6834 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6835 if (event
->ctx
->task
) {
6836 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6837 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6839 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6840 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6841 se
->event_id
.next_prev_pid
=
6842 perf_event_pid(event
, se
->next_prev
);
6843 se
->event_id
.next_prev_tid
=
6844 perf_event_tid(event
, se
->next_prev
);
6847 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6849 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6853 if (event
->ctx
->task
)
6854 perf_output_put(&handle
, se
->event_id
.header
);
6856 perf_output_put(&handle
, se
->event_id
);
6858 perf_event__output_id_sample(event
, &handle
, &sample
);
6860 perf_output_end(&handle
);
6863 static void perf_event_switch(struct task_struct
*task
,
6864 struct task_struct
*next_prev
, bool sched_in
)
6866 struct perf_switch_event switch_event
;
6868 /* N.B. caller checks nr_switch_events != 0 */
6870 switch_event
= (struct perf_switch_event
){
6872 .next_prev
= next_prev
,
6876 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6879 /* .next_prev_pid */
6880 /* .next_prev_tid */
6884 perf_iterate_sb(perf_event_switch_output
,
6890 * IRQ throttle logging
6893 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6895 struct perf_output_handle handle
;
6896 struct perf_sample_data sample
;
6900 struct perf_event_header header
;
6904 } throttle_event
= {
6906 .type
= PERF_RECORD_THROTTLE
,
6908 .size
= sizeof(throttle_event
),
6910 .time
= perf_event_clock(event
),
6911 .id
= primary_event_id(event
),
6912 .stream_id
= event
->id
,
6916 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6918 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6920 ret
= perf_output_begin(&handle
, event
,
6921 throttle_event
.header
.size
);
6925 perf_output_put(&handle
, throttle_event
);
6926 perf_event__output_id_sample(event
, &handle
, &sample
);
6927 perf_output_end(&handle
);
6930 static void perf_log_itrace_start(struct perf_event
*event
)
6932 struct perf_output_handle handle
;
6933 struct perf_sample_data sample
;
6934 struct perf_aux_event
{
6935 struct perf_event_header header
;
6942 event
= event
->parent
;
6944 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6945 event
->hw
.itrace_started
)
6948 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6949 rec
.header
.misc
= 0;
6950 rec
.header
.size
= sizeof(rec
);
6951 rec
.pid
= perf_event_pid(event
, current
);
6952 rec
.tid
= perf_event_tid(event
, current
);
6954 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6955 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6960 perf_output_put(&handle
, rec
);
6961 perf_event__output_id_sample(event
, &handle
, &sample
);
6963 perf_output_end(&handle
);
6967 * Generic event overflow handling, sampling.
6970 static int __perf_event_overflow(struct perf_event
*event
,
6971 int throttle
, struct perf_sample_data
*data
,
6972 struct pt_regs
*regs
)
6974 int events
= atomic_read(&event
->event_limit
);
6975 struct hw_perf_event
*hwc
= &event
->hw
;
6980 * Non-sampling counters might still use the PMI to fold short
6981 * hardware counters, ignore those.
6983 if (unlikely(!is_sampling_event(event
)))
6986 seq
= __this_cpu_read(perf_throttled_seq
);
6987 if (seq
!= hwc
->interrupts_seq
) {
6988 hwc
->interrupts_seq
= seq
;
6989 hwc
->interrupts
= 1;
6992 if (unlikely(throttle
6993 && hwc
->interrupts
>= max_samples_per_tick
)) {
6994 __this_cpu_inc(perf_throttled_count
);
6995 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
6996 hwc
->interrupts
= MAX_INTERRUPTS
;
6997 perf_log_throttle(event
, 0);
7002 if (event
->attr
.freq
) {
7003 u64 now
= perf_clock();
7004 s64 delta
= now
- hwc
->freq_time_stamp
;
7006 hwc
->freq_time_stamp
= now
;
7008 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7009 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7013 * XXX event_limit might not quite work as expected on inherited
7017 event
->pending_kill
= POLL_IN
;
7018 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7020 event
->pending_kill
= POLL_HUP
;
7021 event
->pending_disable
= 1;
7022 irq_work_queue(&event
->pending
);
7025 event
->overflow_handler(event
, data
, regs
);
7027 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7028 event
->pending_wakeup
= 1;
7029 irq_work_queue(&event
->pending
);
7035 int perf_event_overflow(struct perf_event
*event
,
7036 struct perf_sample_data
*data
,
7037 struct pt_regs
*regs
)
7039 return __perf_event_overflow(event
, 1, data
, regs
);
7043 * Generic software event infrastructure
7046 struct swevent_htable
{
7047 struct swevent_hlist
*swevent_hlist
;
7048 struct mutex hlist_mutex
;
7051 /* Recursion avoidance in each contexts */
7052 int recursion
[PERF_NR_CONTEXTS
];
7055 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7058 * We directly increment event->count and keep a second value in
7059 * event->hw.period_left to count intervals. This period event
7060 * is kept in the range [-sample_period, 0] so that we can use the
7064 u64
perf_swevent_set_period(struct perf_event
*event
)
7066 struct hw_perf_event
*hwc
= &event
->hw
;
7067 u64 period
= hwc
->last_period
;
7071 hwc
->last_period
= hwc
->sample_period
;
7074 old
= val
= local64_read(&hwc
->period_left
);
7078 nr
= div64_u64(period
+ val
, period
);
7079 offset
= nr
* period
;
7081 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7087 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7088 struct perf_sample_data
*data
,
7089 struct pt_regs
*regs
)
7091 struct hw_perf_event
*hwc
= &event
->hw
;
7095 overflow
= perf_swevent_set_period(event
);
7097 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7100 for (; overflow
; overflow
--) {
7101 if (__perf_event_overflow(event
, throttle
,
7104 * We inhibit the overflow from happening when
7105 * hwc->interrupts == MAX_INTERRUPTS.
7113 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7114 struct perf_sample_data
*data
,
7115 struct pt_regs
*regs
)
7117 struct hw_perf_event
*hwc
= &event
->hw
;
7119 local64_add(nr
, &event
->count
);
7124 if (!is_sampling_event(event
))
7127 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7129 return perf_swevent_overflow(event
, 1, data
, regs
);
7131 data
->period
= event
->hw
.last_period
;
7133 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7134 return perf_swevent_overflow(event
, 1, data
, regs
);
7136 if (local64_add_negative(nr
, &hwc
->period_left
))
7139 perf_swevent_overflow(event
, 0, data
, regs
);
7142 static int perf_exclude_event(struct perf_event
*event
,
7143 struct pt_regs
*regs
)
7145 if (event
->hw
.state
& PERF_HES_STOPPED
)
7149 if (event
->attr
.exclude_user
&& user_mode(regs
))
7152 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7159 static int perf_swevent_match(struct perf_event
*event
,
7160 enum perf_type_id type
,
7162 struct perf_sample_data
*data
,
7163 struct pt_regs
*regs
)
7165 if (event
->attr
.type
!= type
)
7168 if (event
->attr
.config
!= event_id
)
7171 if (perf_exclude_event(event
, regs
))
7177 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7179 u64 val
= event_id
| (type
<< 32);
7181 return hash_64(val
, SWEVENT_HLIST_BITS
);
7184 static inline struct hlist_head
*
7185 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7187 u64 hash
= swevent_hash(type
, event_id
);
7189 return &hlist
->heads
[hash
];
7192 /* For the read side: events when they trigger */
7193 static inline struct hlist_head
*
7194 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7196 struct swevent_hlist
*hlist
;
7198 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7202 return __find_swevent_head(hlist
, type
, event_id
);
7205 /* For the event head insertion and removal in the hlist */
7206 static inline struct hlist_head
*
7207 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7209 struct swevent_hlist
*hlist
;
7210 u32 event_id
= event
->attr
.config
;
7211 u64 type
= event
->attr
.type
;
7214 * Event scheduling is always serialized against hlist allocation
7215 * and release. Which makes the protected version suitable here.
7216 * The context lock guarantees that.
7218 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7219 lockdep_is_held(&event
->ctx
->lock
));
7223 return __find_swevent_head(hlist
, type
, event_id
);
7226 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7228 struct perf_sample_data
*data
,
7229 struct pt_regs
*regs
)
7231 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7232 struct perf_event
*event
;
7233 struct hlist_head
*head
;
7236 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7240 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7241 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7242 perf_swevent_event(event
, nr
, data
, regs
);
7248 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7250 int perf_swevent_get_recursion_context(void)
7252 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7254 return get_recursion_context(swhash
->recursion
);
7256 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7258 void perf_swevent_put_recursion_context(int rctx
)
7260 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7262 put_recursion_context(swhash
->recursion
, rctx
);
7265 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7267 struct perf_sample_data data
;
7269 if (WARN_ON_ONCE(!regs
))
7272 perf_sample_data_init(&data
, addr
, 0);
7273 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7276 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7280 preempt_disable_notrace();
7281 rctx
= perf_swevent_get_recursion_context();
7282 if (unlikely(rctx
< 0))
7285 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7287 perf_swevent_put_recursion_context(rctx
);
7289 preempt_enable_notrace();
7292 static void perf_swevent_read(struct perf_event
*event
)
7296 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7298 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7299 struct hw_perf_event
*hwc
= &event
->hw
;
7300 struct hlist_head
*head
;
7302 if (is_sampling_event(event
)) {
7303 hwc
->last_period
= hwc
->sample_period
;
7304 perf_swevent_set_period(event
);
7307 hwc
->state
= !(flags
& PERF_EF_START
);
7309 head
= find_swevent_head(swhash
, event
);
7310 if (WARN_ON_ONCE(!head
))
7313 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7314 perf_event_update_userpage(event
);
7319 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7321 hlist_del_rcu(&event
->hlist_entry
);
7324 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7326 event
->hw
.state
= 0;
7329 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7331 event
->hw
.state
= PERF_HES_STOPPED
;
7334 /* Deref the hlist from the update side */
7335 static inline struct swevent_hlist
*
7336 swevent_hlist_deref(struct swevent_htable
*swhash
)
7338 return rcu_dereference_protected(swhash
->swevent_hlist
,
7339 lockdep_is_held(&swhash
->hlist_mutex
));
7342 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7344 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7349 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7350 kfree_rcu(hlist
, rcu_head
);
7353 static void swevent_hlist_put_cpu(int cpu
)
7355 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7357 mutex_lock(&swhash
->hlist_mutex
);
7359 if (!--swhash
->hlist_refcount
)
7360 swevent_hlist_release(swhash
);
7362 mutex_unlock(&swhash
->hlist_mutex
);
7365 static void swevent_hlist_put(void)
7369 for_each_possible_cpu(cpu
)
7370 swevent_hlist_put_cpu(cpu
);
7373 static int swevent_hlist_get_cpu(int cpu
)
7375 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7378 mutex_lock(&swhash
->hlist_mutex
);
7379 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
7380 struct swevent_hlist
*hlist
;
7382 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7387 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7389 swhash
->hlist_refcount
++;
7391 mutex_unlock(&swhash
->hlist_mutex
);
7396 static int swevent_hlist_get(void)
7398 int err
, cpu
, failed_cpu
;
7401 for_each_possible_cpu(cpu
) {
7402 err
= swevent_hlist_get_cpu(cpu
);
7412 for_each_possible_cpu(cpu
) {
7413 if (cpu
== failed_cpu
)
7415 swevent_hlist_put_cpu(cpu
);
7422 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7424 static void sw_perf_event_destroy(struct perf_event
*event
)
7426 u64 event_id
= event
->attr
.config
;
7428 WARN_ON(event
->parent
);
7430 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7431 swevent_hlist_put();
7434 static int perf_swevent_init(struct perf_event
*event
)
7436 u64 event_id
= event
->attr
.config
;
7438 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7442 * no branch sampling for software events
7444 if (has_branch_stack(event
))
7448 case PERF_COUNT_SW_CPU_CLOCK
:
7449 case PERF_COUNT_SW_TASK_CLOCK
:
7456 if (event_id
>= PERF_COUNT_SW_MAX
)
7459 if (!event
->parent
) {
7462 err
= swevent_hlist_get();
7466 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7467 event
->destroy
= sw_perf_event_destroy
;
7473 static struct pmu perf_swevent
= {
7474 .task_ctx_nr
= perf_sw_context
,
7476 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7478 .event_init
= perf_swevent_init
,
7479 .add
= perf_swevent_add
,
7480 .del
= perf_swevent_del
,
7481 .start
= perf_swevent_start
,
7482 .stop
= perf_swevent_stop
,
7483 .read
= perf_swevent_read
,
7486 #ifdef CONFIG_EVENT_TRACING
7488 static int perf_tp_filter_match(struct perf_event
*event
,
7489 struct perf_sample_data
*data
)
7491 void *record
= data
->raw
->frag
.data
;
7493 /* only top level events have filters set */
7495 event
= event
->parent
;
7497 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7502 static int perf_tp_event_match(struct perf_event
*event
,
7503 struct perf_sample_data
*data
,
7504 struct pt_regs
*regs
)
7506 if (event
->hw
.state
& PERF_HES_STOPPED
)
7509 * All tracepoints are from kernel-space.
7511 if (event
->attr
.exclude_kernel
)
7514 if (!perf_tp_filter_match(event
, data
))
7520 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7521 struct trace_event_call
*call
, u64 count
,
7522 struct pt_regs
*regs
, struct hlist_head
*head
,
7523 struct task_struct
*task
)
7525 struct bpf_prog
*prog
= call
->prog
;
7528 *(struct pt_regs
**)raw_data
= regs
;
7529 if (!trace_call_bpf(prog
, raw_data
) || hlist_empty(head
)) {
7530 perf_swevent_put_recursion_context(rctx
);
7534 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7537 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7539 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7540 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7541 struct task_struct
*task
)
7543 struct perf_sample_data data
;
7544 struct perf_event
*event
;
7546 struct perf_raw_record raw
= {
7553 perf_sample_data_init(&data
, 0, 0);
7556 perf_trace_buf_update(record
, event_type
);
7558 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7559 if (perf_tp_event_match(event
, &data
, regs
))
7560 perf_swevent_event(event
, count
, &data
, regs
);
7564 * If we got specified a target task, also iterate its context and
7565 * deliver this event there too.
7567 if (task
&& task
!= current
) {
7568 struct perf_event_context
*ctx
;
7569 struct trace_entry
*entry
= record
;
7572 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7576 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7577 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7579 if (event
->attr
.config
!= entry
->type
)
7581 if (perf_tp_event_match(event
, &data
, regs
))
7582 perf_swevent_event(event
, count
, &data
, regs
);
7588 perf_swevent_put_recursion_context(rctx
);
7590 EXPORT_SYMBOL_GPL(perf_tp_event
);
7592 static void tp_perf_event_destroy(struct perf_event
*event
)
7594 perf_trace_destroy(event
);
7597 static int perf_tp_event_init(struct perf_event
*event
)
7601 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7605 * no branch sampling for tracepoint events
7607 if (has_branch_stack(event
))
7610 err
= perf_trace_init(event
);
7614 event
->destroy
= tp_perf_event_destroy
;
7619 static struct pmu perf_tracepoint
= {
7620 .task_ctx_nr
= perf_sw_context
,
7622 .event_init
= perf_tp_event_init
,
7623 .add
= perf_trace_add
,
7624 .del
= perf_trace_del
,
7625 .start
= perf_swevent_start
,
7626 .stop
= perf_swevent_stop
,
7627 .read
= perf_swevent_read
,
7630 static inline void perf_tp_register(void)
7632 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7635 static void perf_event_free_filter(struct perf_event
*event
)
7637 ftrace_profile_free_filter(event
);
7640 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7642 bool is_kprobe
, is_tracepoint
;
7643 struct bpf_prog
*prog
;
7645 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7648 if (event
->tp_event
->prog
)
7651 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
7652 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
7653 if (!is_kprobe
&& !is_tracepoint
)
7654 /* bpf programs can only be attached to u/kprobe or tracepoint */
7657 prog
= bpf_prog_get(prog_fd
);
7659 return PTR_ERR(prog
);
7661 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
7662 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
7663 /* valid fd, but invalid bpf program type */
7668 if (is_tracepoint
) {
7669 int off
= trace_event_get_offsets(event
->tp_event
);
7671 if (prog
->aux
->max_ctx_offset
> off
) {
7676 event
->tp_event
->prog
= prog
;
7681 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7683 struct bpf_prog
*prog
;
7685 if (!event
->tp_event
)
7688 prog
= event
->tp_event
->prog
;
7690 event
->tp_event
->prog
= NULL
;
7697 static inline void perf_tp_register(void)
7701 static void perf_event_free_filter(struct perf_event
*event
)
7705 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7710 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7713 #endif /* CONFIG_EVENT_TRACING */
7715 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7716 void perf_bp_event(struct perf_event
*bp
, void *data
)
7718 struct perf_sample_data sample
;
7719 struct pt_regs
*regs
= data
;
7721 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7723 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7724 perf_swevent_event(bp
, 1, &sample
, regs
);
7729 * Allocate a new address filter
7731 static struct perf_addr_filter
*
7732 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
7734 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
7735 struct perf_addr_filter
*filter
;
7737 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
7741 INIT_LIST_HEAD(&filter
->entry
);
7742 list_add_tail(&filter
->entry
, filters
);
7747 static void free_filters_list(struct list_head
*filters
)
7749 struct perf_addr_filter
*filter
, *iter
;
7751 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
7753 iput(filter
->inode
);
7754 list_del(&filter
->entry
);
7760 * Free existing address filters and optionally install new ones
7762 static void perf_addr_filters_splice(struct perf_event
*event
,
7763 struct list_head
*head
)
7765 unsigned long flags
;
7768 if (!has_addr_filter(event
))
7771 /* don't bother with children, they don't have their own filters */
7775 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
7777 list_splice_init(&event
->addr_filters
.list
, &list
);
7779 list_splice(head
, &event
->addr_filters
.list
);
7781 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
7783 free_filters_list(&list
);
7787 * Scan through mm's vmas and see if one of them matches the
7788 * @filter; if so, adjust filter's address range.
7789 * Called with mm::mmap_sem down for reading.
7791 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
7792 struct mm_struct
*mm
)
7794 struct vm_area_struct
*vma
;
7796 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
7797 struct file
*file
= vma
->vm_file
;
7798 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
7799 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
7804 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
7807 return vma
->vm_start
;
7814 * Update event's address range filters based on the
7815 * task's existing mappings, if any.
7817 static void perf_event_addr_filters_apply(struct perf_event
*event
)
7819 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7820 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
7821 struct perf_addr_filter
*filter
;
7822 struct mm_struct
*mm
= NULL
;
7823 unsigned int count
= 0;
7824 unsigned long flags
;
7827 * We may observe TASK_TOMBSTONE, which means that the event tear-down
7828 * will stop on the parent's child_mutex that our caller is also holding
7830 if (task
== TASK_TOMBSTONE
)
7833 mm
= get_task_mm(event
->ctx
->task
);
7837 down_read(&mm
->mmap_sem
);
7839 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7840 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7841 event
->addr_filters_offs
[count
] = 0;
7844 * Adjust base offset if the filter is associated to a binary
7845 * that needs to be mapped:
7848 event
->addr_filters_offs
[count
] =
7849 perf_addr_filter_apply(filter
, mm
);
7854 event
->addr_filters_gen
++;
7855 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7857 up_read(&mm
->mmap_sem
);
7862 perf_event_restart(event
);
7866 * Address range filtering: limiting the data to certain
7867 * instruction address ranges. Filters are ioctl()ed to us from
7868 * userspace as ascii strings.
7870 * Filter string format:
7873 * where ACTION is one of the
7874 * * "filter": limit the trace to this region
7875 * * "start": start tracing from this address
7876 * * "stop": stop tracing at this address/region;
7878 * * for kernel addresses: <start address>[/<size>]
7879 * * for object files: <start address>[/<size>]@</path/to/object/file>
7881 * if <size> is not specified, the range is treated as a single address.
7894 IF_STATE_ACTION
= 0,
7899 static const match_table_t if_tokens
= {
7900 { IF_ACT_FILTER
, "filter" },
7901 { IF_ACT_START
, "start" },
7902 { IF_ACT_STOP
, "stop" },
7903 { IF_SRC_FILE
, "%u/%u@%s" },
7904 { IF_SRC_KERNEL
, "%u/%u" },
7905 { IF_SRC_FILEADDR
, "%u@%s" },
7906 { IF_SRC_KERNELADDR
, "%u" },
7910 * Address filter string parser
7913 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
7914 struct list_head
*filters
)
7916 struct perf_addr_filter
*filter
= NULL
;
7917 char *start
, *orig
, *filename
= NULL
;
7919 substring_t args
[MAX_OPT_ARGS
];
7920 int state
= IF_STATE_ACTION
, token
;
7921 unsigned int kernel
= 0;
7924 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
7928 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
7934 /* filter definition begins */
7935 if (state
== IF_STATE_ACTION
) {
7936 filter
= perf_addr_filter_new(event
, filters
);
7941 token
= match_token(start
, if_tokens
, args
);
7948 if (state
!= IF_STATE_ACTION
)
7951 state
= IF_STATE_SOURCE
;
7954 case IF_SRC_KERNELADDR
:
7958 case IF_SRC_FILEADDR
:
7960 if (state
!= IF_STATE_SOURCE
)
7963 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
7967 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
7971 if (filter
->range
) {
7973 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
7978 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
7979 int fpos
= filter
->range
? 2 : 1;
7981 filename
= match_strdup(&args
[fpos
]);
7988 state
= IF_STATE_END
;
7996 * Filter definition is fully parsed, validate and install it.
7997 * Make sure that it doesn't contradict itself or the event's
8000 if (state
== IF_STATE_END
) {
8001 if (kernel
&& event
->attr
.exclude_kernel
)
8008 /* look up the path and grab its inode */
8009 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8011 goto fail_free_name
;
8013 filter
->inode
= igrab(d_inode(path
.dentry
));
8019 if (!filter
->inode
||
8020 !S_ISREG(filter
->inode
->i_mode
))
8021 /* free_filters_list() will iput() */
8025 /* ready to consume more filters */
8026 state
= IF_STATE_ACTION
;
8031 if (state
!= IF_STATE_ACTION
)
8041 free_filters_list(filters
);
8048 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8054 * Since this is called in perf_ioctl() path, we're already holding
8057 lockdep_assert_held(&event
->ctx
->mutex
);
8059 if (WARN_ON_ONCE(event
->parent
))
8063 * For now, we only support filtering in per-task events; doing so
8064 * for CPU-wide events requires additional context switching trickery,
8065 * since same object code will be mapped at different virtual
8066 * addresses in different processes.
8068 if (!event
->ctx
->task
)
8071 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8075 ret
= event
->pmu
->addr_filters_validate(&filters
);
8077 free_filters_list(&filters
);
8081 /* remove existing filters, if any */
8082 perf_addr_filters_splice(event
, &filters
);
8084 /* install new filters */
8085 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8090 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8095 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8096 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8097 !has_addr_filter(event
))
8100 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8101 if (IS_ERR(filter_str
))
8102 return PTR_ERR(filter_str
);
8104 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8105 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8106 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
8108 else if (has_addr_filter(event
))
8109 ret
= perf_event_set_addr_filter(event
, filter_str
);
8116 * hrtimer based swevent callback
8119 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8121 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8122 struct perf_sample_data data
;
8123 struct pt_regs
*regs
;
8124 struct perf_event
*event
;
8127 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8129 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8130 return HRTIMER_NORESTART
;
8132 event
->pmu
->read(event
);
8134 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8135 regs
= get_irq_regs();
8137 if (regs
&& !perf_exclude_event(event
, regs
)) {
8138 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8139 if (__perf_event_overflow(event
, 1, &data
, regs
))
8140 ret
= HRTIMER_NORESTART
;
8143 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8144 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8149 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8151 struct hw_perf_event
*hwc
= &event
->hw
;
8154 if (!is_sampling_event(event
))
8157 period
= local64_read(&hwc
->period_left
);
8162 local64_set(&hwc
->period_left
, 0);
8164 period
= max_t(u64
, 10000, hwc
->sample_period
);
8166 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8167 HRTIMER_MODE_REL_PINNED
);
8170 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8172 struct hw_perf_event
*hwc
= &event
->hw
;
8174 if (is_sampling_event(event
)) {
8175 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8176 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8178 hrtimer_cancel(&hwc
->hrtimer
);
8182 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8184 struct hw_perf_event
*hwc
= &event
->hw
;
8186 if (!is_sampling_event(event
))
8189 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8190 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8193 * Since hrtimers have a fixed rate, we can do a static freq->period
8194 * mapping and avoid the whole period adjust feedback stuff.
8196 if (event
->attr
.freq
) {
8197 long freq
= event
->attr
.sample_freq
;
8199 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8200 hwc
->sample_period
= event
->attr
.sample_period
;
8201 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8202 hwc
->last_period
= hwc
->sample_period
;
8203 event
->attr
.freq
= 0;
8208 * Software event: cpu wall time clock
8211 static void cpu_clock_event_update(struct perf_event
*event
)
8216 now
= local_clock();
8217 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8218 local64_add(now
- prev
, &event
->count
);
8221 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8223 local64_set(&event
->hw
.prev_count
, local_clock());
8224 perf_swevent_start_hrtimer(event
);
8227 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8229 perf_swevent_cancel_hrtimer(event
);
8230 cpu_clock_event_update(event
);
8233 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8235 if (flags
& PERF_EF_START
)
8236 cpu_clock_event_start(event
, flags
);
8237 perf_event_update_userpage(event
);
8242 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8244 cpu_clock_event_stop(event
, flags
);
8247 static void cpu_clock_event_read(struct perf_event
*event
)
8249 cpu_clock_event_update(event
);
8252 static int cpu_clock_event_init(struct perf_event
*event
)
8254 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8257 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8261 * no branch sampling for software events
8263 if (has_branch_stack(event
))
8266 perf_swevent_init_hrtimer(event
);
8271 static struct pmu perf_cpu_clock
= {
8272 .task_ctx_nr
= perf_sw_context
,
8274 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8276 .event_init
= cpu_clock_event_init
,
8277 .add
= cpu_clock_event_add
,
8278 .del
= cpu_clock_event_del
,
8279 .start
= cpu_clock_event_start
,
8280 .stop
= cpu_clock_event_stop
,
8281 .read
= cpu_clock_event_read
,
8285 * Software event: task time clock
8288 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8293 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8295 local64_add(delta
, &event
->count
);
8298 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8300 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8301 perf_swevent_start_hrtimer(event
);
8304 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8306 perf_swevent_cancel_hrtimer(event
);
8307 task_clock_event_update(event
, event
->ctx
->time
);
8310 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8312 if (flags
& PERF_EF_START
)
8313 task_clock_event_start(event
, flags
);
8314 perf_event_update_userpage(event
);
8319 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8321 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8324 static void task_clock_event_read(struct perf_event
*event
)
8326 u64 now
= perf_clock();
8327 u64 delta
= now
- event
->ctx
->timestamp
;
8328 u64 time
= event
->ctx
->time
+ delta
;
8330 task_clock_event_update(event
, time
);
8333 static int task_clock_event_init(struct perf_event
*event
)
8335 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8338 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8342 * no branch sampling for software events
8344 if (has_branch_stack(event
))
8347 perf_swevent_init_hrtimer(event
);
8352 static struct pmu perf_task_clock
= {
8353 .task_ctx_nr
= perf_sw_context
,
8355 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8357 .event_init
= task_clock_event_init
,
8358 .add
= task_clock_event_add
,
8359 .del
= task_clock_event_del
,
8360 .start
= task_clock_event_start
,
8361 .stop
= task_clock_event_stop
,
8362 .read
= task_clock_event_read
,
8365 static void perf_pmu_nop_void(struct pmu
*pmu
)
8369 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8373 static int perf_pmu_nop_int(struct pmu
*pmu
)
8378 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8380 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8382 __this_cpu_write(nop_txn_flags
, flags
);
8384 if (flags
& ~PERF_PMU_TXN_ADD
)
8387 perf_pmu_disable(pmu
);
8390 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8392 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8394 __this_cpu_write(nop_txn_flags
, 0);
8396 if (flags
& ~PERF_PMU_TXN_ADD
)
8399 perf_pmu_enable(pmu
);
8403 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8405 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8407 __this_cpu_write(nop_txn_flags
, 0);
8409 if (flags
& ~PERF_PMU_TXN_ADD
)
8412 perf_pmu_enable(pmu
);
8415 static int perf_event_idx_default(struct perf_event
*event
)
8421 * Ensures all contexts with the same task_ctx_nr have the same
8422 * pmu_cpu_context too.
8424 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8431 list_for_each_entry(pmu
, &pmus
, entry
) {
8432 if (pmu
->task_ctx_nr
== ctxn
)
8433 return pmu
->pmu_cpu_context
;
8439 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
8443 for_each_possible_cpu(cpu
) {
8444 struct perf_cpu_context
*cpuctx
;
8446 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8448 if (cpuctx
->unique_pmu
== old_pmu
)
8449 cpuctx
->unique_pmu
= pmu
;
8453 static void free_pmu_context(struct pmu
*pmu
)
8457 mutex_lock(&pmus_lock
);
8459 * Like a real lame refcount.
8461 list_for_each_entry(i
, &pmus
, entry
) {
8462 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
8463 update_pmu_context(i
, pmu
);
8468 free_percpu(pmu
->pmu_cpu_context
);
8470 mutex_unlock(&pmus_lock
);
8474 * Let userspace know that this PMU supports address range filtering:
8476 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8477 struct device_attribute
*attr
,
8480 struct pmu
*pmu
= dev_get_drvdata(dev
);
8482 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8484 DEVICE_ATTR_RO(nr_addr_filters
);
8486 static struct idr pmu_idr
;
8489 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8491 struct pmu
*pmu
= dev_get_drvdata(dev
);
8493 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8495 static DEVICE_ATTR_RO(type
);
8498 perf_event_mux_interval_ms_show(struct device
*dev
,
8499 struct device_attribute
*attr
,
8502 struct pmu
*pmu
= dev_get_drvdata(dev
);
8504 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8507 static DEFINE_MUTEX(mux_interval_mutex
);
8510 perf_event_mux_interval_ms_store(struct device
*dev
,
8511 struct device_attribute
*attr
,
8512 const char *buf
, size_t count
)
8514 struct pmu
*pmu
= dev_get_drvdata(dev
);
8515 int timer
, cpu
, ret
;
8517 ret
= kstrtoint(buf
, 0, &timer
);
8524 /* same value, noting to do */
8525 if (timer
== pmu
->hrtimer_interval_ms
)
8528 mutex_lock(&mux_interval_mutex
);
8529 pmu
->hrtimer_interval_ms
= timer
;
8531 /* update all cpuctx for this PMU */
8533 for_each_online_cpu(cpu
) {
8534 struct perf_cpu_context
*cpuctx
;
8535 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8536 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
8538 cpu_function_call(cpu
,
8539 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
8542 mutex_unlock(&mux_interval_mutex
);
8546 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
8548 static struct attribute
*pmu_dev_attrs
[] = {
8549 &dev_attr_type
.attr
,
8550 &dev_attr_perf_event_mux_interval_ms
.attr
,
8553 ATTRIBUTE_GROUPS(pmu_dev
);
8555 static int pmu_bus_running
;
8556 static struct bus_type pmu_bus
= {
8557 .name
= "event_source",
8558 .dev_groups
= pmu_dev_groups
,
8561 static void pmu_dev_release(struct device
*dev
)
8566 static int pmu_dev_alloc(struct pmu
*pmu
)
8570 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
8574 pmu
->dev
->groups
= pmu
->attr_groups
;
8575 device_initialize(pmu
->dev
);
8576 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
8580 dev_set_drvdata(pmu
->dev
, pmu
);
8581 pmu
->dev
->bus
= &pmu_bus
;
8582 pmu
->dev
->release
= pmu_dev_release
;
8583 ret
= device_add(pmu
->dev
);
8587 /* For PMUs with address filters, throw in an extra attribute: */
8588 if (pmu
->nr_addr_filters
)
8589 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
8598 device_del(pmu
->dev
);
8601 put_device(pmu
->dev
);
8605 static struct lock_class_key cpuctx_mutex
;
8606 static struct lock_class_key cpuctx_lock
;
8608 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
8612 mutex_lock(&pmus_lock
);
8614 pmu
->pmu_disable_count
= alloc_percpu(int);
8615 if (!pmu
->pmu_disable_count
)
8624 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
8632 if (pmu_bus_running
) {
8633 ret
= pmu_dev_alloc(pmu
);
8639 if (pmu
->task_ctx_nr
== perf_hw_context
) {
8640 static int hw_context_taken
= 0;
8643 * Other than systems with heterogeneous CPUs, it never makes
8644 * sense for two PMUs to share perf_hw_context. PMUs which are
8645 * uncore must use perf_invalid_context.
8647 if (WARN_ON_ONCE(hw_context_taken
&&
8648 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
8649 pmu
->task_ctx_nr
= perf_invalid_context
;
8651 hw_context_taken
= 1;
8654 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
8655 if (pmu
->pmu_cpu_context
)
8656 goto got_cpu_context
;
8659 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
8660 if (!pmu
->pmu_cpu_context
)
8663 for_each_possible_cpu(cpu
) {
8664 struct perf_cpu_context
*cpuctx
;
8666 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8667 __perf_event_init_context(&cpuctx
->ctx
);
8668 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
8669 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
8670 cpuctx
->ctx
.pmu
= pmu
;
8672 __perf_mux_hrtimer_init(cpuctx
, cpu
);
8674 cpuctx
->unique_pmu
= pmu
;
8678 if (!pmu
->start_txn
) {
8679 if (pmu
->pmu_enable
) {
8681 * If we have pmu_enable/pmu_disable calls, install
8682 * transaction stubs that use that to try and batch
8683 * hardware accesses.
8685 pmu
->start_txn
= perf_pmu_start_txn
;
8686 pmu
->commit_txn
= perf_pmu_commit_txn
;
8687 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
8689 pmu
->start_txn
= perf_pmu_nop_txn
;
8690 pmu
->commit_txn
= perf_pmu_nop_int
;
8691 pmu
->cancel_txn
= perf_pmu_nop_void
;
8695 if (!pmu
->pmu_enable
) {
8696 pmu
->pmu_enable
= perf_pmu_nop_void
;
8697 pmu
->pmu_disable
= perf_pmu_nop_void
;
8700 if (!pmu
->event_idx
)
8701 pmu
->event_idx
= perf_event_idx_default
;
8703 list_add_rcu(&pmu
->entry
, &pmus
);
8704 atomic_set(&pmu
->exclusive_cnt
, 0);
8707 mutex_unlock(&pmus_lock
);
8712 device_del(pmu
->dev
);
8713 put_device(pmu
->dev
);
8716 if (pmu
->type
>= PERF_TYPE_MAX
)
8717 idr_remove(&pmu_idr
, pmu
->type
);
8720 free_percpu(pmu
->pmu_disable_count
);
8723 EXPORT_SYMBOL_GPL(perf_pmu_register
);
8725 void perf_pmu_unregister(struct pmu
*pmu
)
8727 mutex_lock(&pmus_lock
);
8728 list_del_rcu(&pmu
->entry
);
8729 mutex_unlock(&pmus_lock
);
8732 * We dereference the pmu list under both SRCU and regular RCU, so
8733 * synchronize against both of those.
8735 synchronize_srcu(&pmus_srcu
);
8738 free_percpu(pmu
->pmu_disable_count
);
8739 if (pmu
->type
>= PERF_TYPE_MAX
)
8740 idr_remove(&pmu_idr
, pmu
->type
);
8741 if (pmu
->nr_addr_filters
)
8742 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
8743 device_del(pmu
->dev
);
8744 put_device(pmu
->dev
);
8745 free_pmu_context(pmu
);
8747 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
8749 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
8751 struct perf_event_context
*ctx
= NULL
;
8754 if (!try_module_get(pmu
->module
))
8757 if (event
->group_leader
!= event
) {
8759 * This ctx->mutex can nest when we're called through
8760 * inheritance. See the perf_event_ctx_lock_nested() comment.
8762 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
8763 SINGLE_DEPTH_NESTING
);
8768 ret
= pmu
->event_init(event
);
8771 perf_event_ctx_unlock(event
->group_leader
, ctx
);
8774 module_put(pmu
->module
);
8779 static struct pmu
*perf_init_event(struct perf_event
*event
)
8781 struct pmu
*pmu
= NULL
;
8785 idx
= srcu_read_lock(&pmus_srcu
);
8788 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
8791 ret
= perf_try_init_event(pmu
, event
);
8797 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
8798 ret
= perf_try_init_event(pmu
, event
);
8802 if (ret
!= -ENOENT
) {
8807 pmu
= ERR_PTR(-ENOENT
);
8809 srcu_read_unlock(&pmus_srcu
, idx
);
8814 static void attach_sb_event(struct perf_event
*event
)
8816 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
8818 raw_spin_lock(&pel
->lock
);
8819 list_add_rcu(&event
->sb_list
, &pel
->list
);
8820 raw_spin_unlock(&pel
->lock
);
8824 * We keep a list of all !task (and therefore per-cpu) events
8825 * that need to receive side-band records.
8827 * This avoids having to scan all the various PMU per-cpu contexts
8830 static void account_pmu_sb_event(struct perf_event
*event
)
8832 if (is_sb_event(event
))
8833 attach_sb_event(event
);
8836 static void account_event_cpu(struct perf_event
*event
, int cpu
)
8841 if (is_cgroup_event(event
))
8842 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
8845 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
8846 static void account_freq_event_nohz(void)
8848 #ifdef CONFIG_NO_HZ_FULL
8849 /* Lock so we don't race with concurrent unaccount */
8850 spin_lock(&nr_freq_lock
);
8851 if (atomic_inc_return(&nr_freq_events
) == 1)
8852 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
8853 spin_unlock(&nr_freq_lock
);
8857 static void account_freq_event(void)
8859 if (tick_nohz_full_enabled())
8860 account_freq_event_nohz();
8862 atomic_inc(&nr_freq_events
);
8866 static void account_event(struct perf_event
*event
)
8873 if (event
->attach_state
& PERF_ATTACH_TASK
)
8875 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
8876 atomic_inc(&nr_mmap_events
);
8877 if (event
->attr
.comm
)
8878 atomic_inc(&nr_comm_events
);
8879 if (event
->attr
.task
)
8880 atomic_inc(&nr_task_events
);
8881 if (event
->attr
.freq
)
8882 account_freq_event();
8883 if (event
->attr
.context_switch
) {
8884 atomic_inc(&nr_switch_events
);
8887 if (has_branch_stack(event
))
8889 if (is_cgroup_event(event
))
8893 if (atomic_inc_not_zero(&perf_sched_count
))
8896 mutex_lock(&perf_sched_mutex
);
8897 if (!atomic_read(&perf_sched_count
)) {
8898 static_branch_enable(&perf_sched_events
);
8900 * Guarantee that all CPUs observe they key change and
8901 * call the perf scheduling hooks before proceeding to
8902 * install events that need them.
8904 synchronize_sched();
8907 * Now that we have waited for the sync_sched(), allow further
8908 * increments to by-pass the mutex.
8910 atomic_inc(&perf_sched_count
);
8911 mutex_unlock(&perf_sched_mutex
);
8915 account_event_cpu(event
, event
->cpu
);
8917 account_pmu_sb_event(event
);
8921 * Allocate and initialize a event structure
8923 static struct perf_event
*
8924 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
8925 struct task_struct
*task
,
8926 struct perf_event
*group_leader
,
8927 struct perf_event
*parent_event
,
8928 perf_overflow_handler_t overflow_handler
,
8929 void *context
, int cgroup_fd
)
8932 struct perf_event
*event
;
8933 struct hw_perf_event
*hwc
;
8936 if ((unsigned)cpu
>= nr_cpu_ids
) {
8937 if (!task
|| cpu
!= -1)
8938 return ERR_PTR(-EINVAL
);
8941 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
8943 return ERR_PTR(-ENOMEM
);
8946 * Single events are their own group leaders, with an
8947 * empty sibling list:
8950 group_leader
= event
;
8952 mutex_init(&event
->child_mutex
);
8953 INIT_LIST_HEAD(&event
->child_list
);
8955 INIT_LIST_HEAD(&event
->group_entry
);
8956 INIT_LIST_HEAD(&event
->event_entry
);
8957 INIT_LIST_HEAD(&event
->sibling_list
);
8958 INIT_LIST_HEAD(&event
->rb_entry
);
8959 INIT_LIST_HEAD(&event
->active_entry
);
8960 INIT_LIST_HEAD(&event
->addr_filters
.list
);
8961 INIT_HLIST_NODE(&event
->hlist_entry
);
8964 init_waitqueue_head(&event
->waitq
);
8965 init_irq_work(&event
->pending
, perf_pending_event
);
8967 mutex_init(&event
->mmap_mutex
);
8968 raw_spin_lock_init(&event
->addr_filters
.lock
);
8970 atomic_long_set(&event
->refcount
, 1);
8972 event
->attr
= *attr
;
8973 event
->group_leader
= group_leader
;
8977 event
->parent
= parent_event
;
8979 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
8980 event
->id
= atomic64_inc_return(&perf_event_id
);
8982 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8985 event
->attach_state
= PERF_ATTACH_TASK
;
8987 * XXX pmu::event_init needs to know what task to account to
8988 * and we cannot use the ctx information because we need the
8989 * pmu before we get a ctx.
8991 event
->hw
.target
= task
;
8994 event
->clock
= &local_clock
;
8996 event
->clock
= parent_event
->clock
;
8998 if (!overflow_handler
&& parent_event
) {
8999 overflow_handler
= parent_event
->overflow_handler
;
9000 context
= parent_event
->overflow_handler_context
;
9003 if (overflow_handler
) {
9004 event
->overflow_handler
= overflow_handler
;
9005 event
->overflow_handler_context
= context
;
9006 } else if (is_write_backward(event
)){
9007 event
->overflow_handler
= perf_event_output_backward
;
9008 event
->overflow_handler_context
= NULL
;
9010 event
->overflow_handler
= perf_event_output_forward
;
9011 event
->overflow_handler_context
= NULL
;
9014 perf_event__state_init(event
);
9019 hwc
->sample_period
= attr
->sample_period
;
9020 if (attr
->freq
&& attr
->sample_freq
)
9021 hwc
->sample_period
= 1;
9022 hwc
->last_period
= hwc
->sample_period
;
9024 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9027 * we currently do not support PERF_FORMAT_GROUP on inherited events
9029 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
9032 if (!has_branch_stack(event
))
9033 event
->attr
.branch_sample_type
= 0;
9035 if (cgroup_fd
!= -1) {
9036 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9041 pmu
= perf_init_event(event
);
9044 else if (IS_ERR(pmu
)) {
9049 err
= exclusive_event_init(event
);
9053 if (has_addr_filter(event
)) {
9054 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9055 sizeof(unsigned long),
9057 if (!event
->addr_filters_offs
)
9060 /* force hw sync on the address filters */
9061 event
->addr_filters_gen
= 1;
9064 if (!event
->parent
) {
9065 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9066 err
= get_callchain_buffers(attr
->sample_max_stack
);
9068 goto err_addr_filters
;
9072 /* symmetric to unaccount_event() in _free_event() */
9073 account_event(event
);
9078 kfree(event
->addr_filters_offs
);
9081 exclusive_event_destroy(event
);
9085 event
->destroy(event
);
9086 module_put(pmu
->module
);
9088 if (is_cgroup_event(event
))
9089 perf_detach_cgroup(event
);
9091 put_pid_ns(event
->ns
);
9094 return ERR_PTR(err
);
9097 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9098 struct perf_event_attr
*attr
)
9103 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9107 * zero the full structure, so that a short copy will be nice.
9109 memset(attr
, 0, sizeof(*attr
));
9111 ret
= get_user(size
, &uattr
->size
);
9115 if (size
> PAGE_SIZE
) /* silly large */
9118 if (!size
) /* abi compat */
9119 size
= PERF_ATTR_SIZE_VER0
;
9121 if (size
< PERF_ATTR_SIZE_VER0
)
9125 * If we're handed a bigger struct than we know of,
9126 * ensure all the unknown bits are 0 - i.e. new
9127 * user-space does not rely on any kernel feature
9128 * extensions we dont know about yet.
9130 if (size
> sizeof(*attr
)) {
9131 unsigned char __user
*addr
;
9132 unsigned char __user
*end
;
9135 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9136 end
= (void __user
*)uattr
+ size
;
9138 for (; addr
< end
; addr
++) {
9139 ret
= get_user(val
, addr
);
9145 size
= sizeof(*attr
);
9148 ret
= copy_from_user(attr
, uattr
, size
);
9152 if (attr
->__reserved_1
)
9155 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9158 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9161 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9162 u64 mask
= attr
->branch_sample_type
;
9164 /* only using defined bits */
9165 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9168 /* at least one branch bit must be set */
9169 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9172 /* propagate priv level, when not set for branch */
9173 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9175 /* exclude_kernel checked on syscall entry */
9176 if (!attr
->exclude_kernel
)
9177 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9179 if (!attr
->exclude_user
)
9180 mask
|= PERF_SAMPLE_BRANCH_USER
;
9182 if (!attr
->exclude_hv
)
9183 mask
|= PERF_SAMPLE_BRANCH_HV
;
9185 * adjust user setting (for HW filter setup)
9187 attr
->branch_sample_type
= mask
;
9189 /* privileged levels capture (kernel, hv): check permissions */
9190 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9191 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9195 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9196 ret
= perf_reg_validate(attr
->sample_regs_user
);
9201 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9202 if (!arch_perf_have_user_stack_dump())
9206 * We have __u32 type for the size, but so far
9207 * we can only use __u16 as maximum due to the
9208 * __u16 sample size limit.
9210 if (attr
->sample_stack_user
>= USHRT_MAX
)
9212 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9216 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9217 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9222 put_user(sizeof(*attr
), &uattr
->size
);
9228 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9230 struct ring_buffer
*rb
= NULL
;
9236 /* don't allow circular references */
9237 if (event
== output_event
)
9241 * Don't allow cross-cpu buffers
9243 if (output_event
->cpu
!= event
->cpu
)
9247 * If its not a per-cpu rb, it must be the same task.
9249 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9253 * Mixing clocks in the same buffer is trouble you don't need.
9255 if (output_event
->clock
!= event
->clock
)
9259 * Either writing ring buffer from beginning or from end.
9260 * Mixing is not allowed.
9262 if (is_write_backward(output_event
) != is_write_backward(event
))
9266 * If both events generate aux data, they must be on the same PMU
9268 if (has_aux(event
) && has_aux(output_event
) &&
9269 event
->pmu
!= output_event
->pmu
)
9273 mutex_lock(&event
->mmap_mutex
);
9274 /* Can't redirect output if we've got an active mmap() */
9275 if (atomic_read(&event
->mmap_count
))
9279 /* get the rb we want to redirect to */
9280 rb
= ring_buffer_get(output_event
);
9285 ring_buffer_attach(event
, rb
);
9289 mutex_unlock(&event
->mmap_mutex
);
9295 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9301 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9304 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9306 bool nmi_safe
= false;
9309 case CLOCK_MONOTONIC
:
9310 event
->clock
= &ktime_get_mono_fast_ns
;
9314 case CLOCK_MONOTONIC_RAW
:
9315 event
->clock
= &ktime_get_raw_fast_ns
;
9319 case CLOCK_REALTIME
:
9320 event
->clock
= &ktime_get_real_ns
;
9323 case CLOCK_BOOTTIME
:
9324 event
->clock
= &ktime_get_boot_ns
;
9328 event
->clock
= &ktime_get_tai_ns
;
9335 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9342 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9344 * @attr_uptr: event_id type attributes for monitoring/sampling
9347 * @group_fd: group leader event fd
9349 SYSCALL_DEFINE5(perf_event_open
,
9350 struct perf_event_attr __user
*, attr_uptr
,
9351 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9353 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9354 struct perf_event
*event
, *sibling
;
9355 struct perf_event_attr attr
;
9356 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9357 struct file
*event_file
= NULL
;
9358 struct fd group
= {NULL
, 0};
9359 struct task_struct
*task
= NULL
;
9364 int f_flags
= O_RDWR
;
9367 /* for future expandability... */
9368 if (flags
& ~PERF_FLAG_ALL
)
9371 err
= perf_copy_attr(attr_uptr
, &attr
);
9375 if (!attr
.exclude_kernel
) {
9376 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9381 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9384 if (attr
.sample_period
& (1ULL << 63))
9388 if (!attr
.sample_max_stack
)
9389 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9392 * In cgroup mode, the pid argument is used to pass the fd
9393 * opened to the cgroup directory in cgroupfs. The cpu argument
9394 * designates the cpu on which to monitor threads from that
9397 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9400 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9401 f_flags
|= O_CLOEXEC
;
9403 event_fd
= get_unused_fd_flags(f_flags
);
9407 if (group_fd
!= -1) {
9408 err
= perf_fget_light(group_fd
, &group
);
9411 group_leader
= group
.file
->private_data
;
9412 if (flags
& PERF_FLAG_FD_OUTPUT
)
9413 output_event
= group_leader
;
9414 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9415 group_leader
= NULL
;
9418 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9419 task
= find_lively_task_by_vpid(pid
);
9421 err
= PTR_ERR(task
);
9426 if (task
&& group_leader
&&
9427 group_leader
->attr
.inherit
!= attr
.inherit
) {
9435 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
9440 * Reuse ptrace permission checks for now.
9442 * We must hold cred_guard_mutex across this and any potential
9443 * perf_install_in_context() call for this new event to
9444 * serialize against exec() altering our credentials (and the
9445 * perf_event_exit_task() that could imply).
9448 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
9452 if (flags
& PERF_FLAG_PID_CGROUP
)
9455 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
9456 NULL
, NULL
, cgroup_fd
);
9457 if (IS_ERR(event
)) {
9458 err
= PTR_ERR(event
);
9462 if (is_sampling_event(event
)) {
9463 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
9470 * Special case software events and allow them to be part of
9471 * any hardware group.
9475 if (attr
.use_clockid
) {
9476 err
= perf_event_set_clock(event
, attr
.clockid
);
9482 (is_software_event(event
) != is_software_event(group_leader
))) {
9483 if (is_software_event(event
)) {
9485 * If event and group_leader are not both a software
9486 * event, and event is, then group leader is not.
9488 * Allow the addition of software events to !software
9489 * groups, this is safe because software events never
9492 pmu
= group_leader
->pmu
;
9493 } else if (is_software_event(group_leader
) &&
9494 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
9496 * In case the group is a pure software group, and we
9497 * try to add a hardware event, move the whole group to
9498 * the hardware context.
9505 * Get the target context (task or percpu):
9507 ctx
= find_get_context(pmu
, task
, event
);
9513 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
9519 * Look up the group leader (we will attach this event to it):
9525 * Do not allow a recursive hierarchy (this new sibling
9526 * becoming part of another group-sibling):
9528 if (group_leader
->group_leader
!= group_leader
)
9531 /* All events in a group should have the same clock */
9532 if (group_leader
->clock
!= event
->clock
)
9536 * Do not allow to attach to a group in a different
9537 * task or CPU context:
9541 * Make sure we're both on the same task, or both
9544 if (group_leader
->ctx
->task
!= ctx
->task
)
9548 * Make sure we're both events for the same CPU;
9549 * grouping events for different CPUs is broken; since
9550 * you can never concurrently schedule them anyhow.
9552 if (group_leader
->cpu
!= event
->cpu
)
9555 if (group_leader
->ctx
!= ctx
)
9560 * Only a group leader can be exclusive or pinned
9562 if (attr
.exclusive
|| attr
.pinned
)
9567 err
= perf_event_set_output(event
, output_event
);
9572 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
9574 if (IS_ERR(event_file
)) {
9575 err
= PTR_ERR(event_file
);
9581 gctx
= group_leader
->ctx
;
9582 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9583 if (gctx
->task
== TASK_TOMBSTONE
) {
9588 mutex_lock(&ctx
->mutex
);
9591 if (ctx
->task
== TASK_TOMBSTONE
) {
9596 if (!perf_event_validate_size(event
)) {
9602 * Must be under the same ctx::mutex as perf_install_in_context(),
9603 * because we need to serialize with concurrent event creation.
9605 if (!exclusive_event_installable(event
, ctx
)) {
9606 /* exclusive and group stuff are assumed mutually exclusive */
9607 WARN_ON_ONCE(move_group
);
9613 WARN_ON_ONCE(ctx
->parent_ctx
);
9616 * This is the point on no return; we cannot fail hereafter. This is
9617 * where we start modifying current state.
9622 * See perf_event_ctx_lock() for comments on the details
9623 * of swizzling perf_event::ctx.
9625 perf_remove_from_context(group_leader
, 0);
9627 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
9629 perf_remove_from_context(sibling
, 0);
9634 * Wait for everybody to stop referencing the events through
9635 * the old lists, before installing it on new lists.
9640 * Install the group siblings before the group leader.
9642 * Because a group leader will try and install the entire group
9643 * (through the sibling list, which is still in-tact), we can
9644 * end up with siblings installed in the wrong context.
9646 * By installing siblings first we NO-OP because they're not
9647 * reachable through the group lists.
9649 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
9651 perf_event__state_init(sibling
);
9652 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
9657 * Removing from the context ends up with disabled
9658 * event. What we want here is event in the initial
9659 * startup state, ready to be add into new context.
9661 perf_event__state_init(group_leader
);
9662 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
9666 * Now that all events are installed in @ctx, nothing
9667 * references @gctx anymore, so drop the last reference we have
9674 * Precalculate sample_data sizes; do while holding ctx::mutex such
9675 * that we're serialized against further additions and before
9676 * perf_install_in_context() which is the point the event is active and
9677 * can use these values.
9679 perf_event__header_size(event
);
9680 perf_event__id_header_size(event
);
9682 event
->owner
= current
;
9684 perf_install_in_context(ctx
, event
, event
->cpu
);
9685 perf_unpin_context(ctx
);
9688 mutex_unlock(&gctx
->mutex
);
9689 mutex_unlock(&ctx
->mutex
);
9692 mutex_unlock(&task
->signal
->cred_guard_mutex
);
9693 put_task_struct(task
);
9698 mutex_lock(¤t
->perf_event_mutex
);
9699 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
9700 mutex_unlock(¤t
->perf_event_mutex
);
9703 * Drop the reference on the group_event after placing the
9704 * new event on the sibling_list. This ensures destruction
9705 * of the group leader will find the pointer to itself in
9706 * perf_group_detach().
9709 fd_install(event_fd
, event_file
);
9714 mutex_unlock(&gctx
->mutex
);
9715 mutex_unlock(&ctx
->mutex
);
9719 perf_unpin_context(ctx
);
9723 * If event_file is set, the fput() above will have called ->release()
9724 * and that will take care of freeing the event.
9730 mutex_unlock(&task
->signal
->cred_guard_mutex
);
9735 put_task_struct(task
);
9739 put_unused_fd(event_fd
);
9744 * perf_event_create_kernel_counter
9746 * @attr: attributes of the counter to create
9747 * @cpu: cpu in which the counter is bound
9748 * @task: task to profile (NULL for percpu)
9751 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
9752 struct task_struct
*task
,
9753 perf_overflow_handler_t overflow_handler
,
9756 struct perf_event_context
*ctx
;
9757 struct perf_event
*event
;
9761 * Get the target context (task or percpu):
9764 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
9765 overflow_handler
, context
, -1);
9766 if (IS_ERR(event
)) {
9767 err
= PTR_ERR(event
);
9771 /* Mark owner so we could distinguish it from user events. */
9772 event
->owner
= TASK_TOMBSTONE
;
9774 ctx
= find_get_context(event
->pmu
, task
, event
);
9780 WARN_ON_ONCE(ctx
->parent_ctx
);
9781 mutex_lock(&ctx
->mutex
);
9782 if (ctx
->task
== TASK_TOMBSTONE
) {
9787 if (!exclusive_event_installable(event
, ctx
)) {
9792 perf_install_in_context(ctx
, event
, cpu
);
9793 perf_unpin_context(ctx
);
9794 mutex_unlock(&ctx
->mutex
);
9799 mutex_unlock(&ctx
->mutex
);
9800 perf_unpin_context(ctx
);
9805 return ERR_PTR(err
);
9807 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
9809 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
9811 struct perf_event_context
*src_ctx
;
9812 struct perf_event_context
*dst_ctx
;
9813 struct perf_event
*event
, *tmp
;
9816 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
9817 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
9820 * See perf_event_ctx_lock() for comments on the details
9821 * of swizzling perf_event::ctx.
9823 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
9824 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
9826 perf_remove_from_context(event
, 0);
9827 unaccount_event_cpu(event
, src_cpu
);
9829 list_add(&event
->migrate_entry
, &events
);
9833 * Wait for the events to quiesce before re-instating them.
9838 * Re-instate events in 2 passes.
9840 * Skip over group leaders and only install siblings on this first
9841 * pass, siblings will not get enabled without a leader, however a
9842 * leader will enable its siblings, even if those are still on the old
9845 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
9846 if (event
->group_leader
== event
)
9849 list_del(&event
->migrate_entry
);
9850 if (event
->state
>= PERF_EVENT_STATE_OFF
)
9851 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9852 account_event_cpu(event
, dst_cpu
);
9853 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
9858 * Once all the siblings are setup properly, install the group leaders
9861 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
9862 list_del(&event
->migrate_entry
);
9863 if (event
->state
>= PERF_EVENT_STATE_OFF
)
9864 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9865 account_event_cpu(event
, dst_cpu
);
9866 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
9869 mutex_unlock(&dst_ctx
->mutex
);
9870 mutex_unlock(&src_ctx
->mutex
);
9872 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
9874 static void sync_child_event(struct perf_event
*child_event
,
9875 struct task_struct
*child
)
9877 struct perf_event
*parent_event
= child_event
->parent
;
9880 if (child_event
->attr
.inherit_stat
)
9881 perf_event_read_event(child_event
, child
);
9883 child_val
= perf_event_count(child_event
);
9886 * Add back the child's count to the parent's count:
9888 atomic64_add(child_val
, &parent_event
->child_count
);
9889 atomic64_add(child_event
->total_time_enabled
,
9890 &parent_event
->child_total_time_enabled
);
9891 atomic64_add(child_event
->total_time_running
,
9892 &parent_event
->child_total_time_running
);
9896 perf_event_exit_event(struct perf_event
*child_event
,
9897 struct perf_event_context
*child_ctx
,
9898 struct task_struct
*child
)
9900 struct perf_event
*parent_event
= child_event
->parent
;
9903 * Do not destroy the 'original' grouping; because of the context
9904 * switch optimization the original events could've ended up in a
9905 * random child task.
9907 * If we were to destroy the original group, all group related
9908 * operations would cease to function properly after this random
9911 * Do destroy all inherited groups, we don't care about those
9912 * and being thorough is better.
9914 raw_spin_lock_irq(&child_ctx
->lock
);
9915 WARN_ON_ONCE(child_ctx
->is_active
);
9918 perf_group_detach(child_event
);
9919 list_del_event(child_event
, child_ctx
);
9920 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
9921 raw_spin_unlock_irq(&child_ctx
->lock
);
9924 * Parent events are governed by their filedesc, retain them.
9926 if (!parent_event
) {
9927 perf_event_wakeup(child_event
);
9931 * Child events can be cleaned up.
9934 sync_child_event(child_event
, child
);
9937 * Remove this event from the parent's list
9939 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
9940 mutex_lock(&parent_event
->child_mutex
);
9941 list_del_init(&child_event
->child_list
);
9942 mutex_unlock(&parent_event
->child_mutex
);
9945 * Kick perf_poll() for is_event_hup().
9947 perf_event_wakeup(parent_event
);
9948 free_event(child_event
);
9949 put_event(parent_event
);
9952 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
9954 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
9955 struct perf_event
*child_event
, *next
;
9957 WARN_ON_ONCE(child
!= current
);
9959 child_ctx
= perf_pin_task_context(child
, ctxn
);
9964 * In order to reduce the amount of tricky in ctx tear-down, we hold
9965 * ctx::mutex over the entire thing. This serializes against almost
9966 * everything that wants to access the ctx.
9968 * The exception is sys_perf_event_open() /
9969 * perf_event_create_kernel_count() which does find_get_context()
9970 * without ctx::mutex (it cannot because of the move_group double mutex
9971 * lock thing). See the comments in perf_install_in_context().
9973 mutex_lock(&child_ctx
->mutex
);
9976 * In a single ctx::lock section, de-schedule the events and detach the
9977 * context from the task such that we cannot ever get it scheduled back
9980 raw_spin_lock_irq(&child_ctx
->lock
);
9981 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
);
9984 * Now that the context is inactive, destroy the task <-> ctx relation
9985 * and mark the context dead.
9987 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
9988 put_ctx(child_ctx
); /* cannot be last */
9989 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
9990 put_task_struct(current
); /* cannot be last */
9992 clone_ctx
= unclone_ctx(child_ctx
);
9993 raw_spin_unlock_irq(&child_ctx
->lock
);
9999 * Report the task dead after unscheduling the events so that we
10000 * won't get any samples after PERF_RECORD_EXIT. We can however still
10001 * get a few PERF_RECORD_READ events.
10003 perf_event_task(child
, child_ctx
, 0);
10005 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10006 perf_event_exit_event(child_event
, child_ctx
, child
);
10008 mutex_unlock(&child_ctx
->mutex
);
10010 put_ctx(child_ctx
);
10014 * When a child task exits, feed back event values to parent events.
10016 * Can be called with cred_guard_mutex held when called from
10017 * install_exec_creds().
10019 void perf_event_exit_task(struct task_struct
*child
)
10021 struct perf_event
*event
, *tmp
;
10024 mutex_lock(&child
->perf_event_mutex
);
10025 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10027 list_del_init(&event
->owner_entry
);
10030 * Ensure the list deletion is visible before we clear
10031 * the owner, closes a race against perf_release() where
10032 * we need to serialize on the owner->perf_event_mutex.
10034 smp_store_release(&event
->owner
, NULL
);
10036 mutex_unlock(&child
->perf_event_mutex
);
10038 for_each_task_context_nr(ctxn
)
10039 perf_event_exit_task_context(child
, ctxn
);
10042 * The perf_event_exit_task_context calls perf_event_task
10043 * with child's task_ctx, which generates EXIT events for
10044 * child contexts and sets child->perf_event_ctxp[] to NULL.
10045 * At this point we need to send EXIT events to cpu contexts.
10047 perf_event_task(child
, NULL
, 0);
10050 static void perf_free_event(struct perf_event
*event
,
10051 struct perf_event_context
*ctx
)
10053 struct perf_event
*parent
= event
->parent
;
10055 if (WARN_ON_ONCE(!parent
))
10058 mutex_lock(&parent
->child_mutex
);
10059 list_del_init(&event
->child_list
);
10060 mutex_unlock(&parent
->child_mutex
);
10064 raw_spin_lock_irq(&ctx
->lock
);
10065 perf_group_detach(event
);
10066 list_del_event(event
, ctx
);
10067 raw_spin_unlock_irq(&ctx
->lock
);
10072 * Free an unexposed, unused context as created by inheritance by
10073 * perf_event_init_task below, used by fork() in case of fail.
10075 * Not all locks are strictly required, but take them anyway to be nice and
10076 * help out with the lockdep assertions.
10078 void perf_event_free_task(struct task_struct
*task
)
10080 struct perf_event_context
*ctx
;
10081 struct perf_event
*event
, *tmp
;
10084 for_each_task_context_nr(ctxn
) {
10085 ctx
= task
->perf_event_ctxp
[ctxn
];
10089 mutex_lock(&ctx
->mutex
);
10091 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
10093 perf_free_event(event
, ctx
);
10095 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
10097 perf_free_event(event
, ctx
);
10099 if (!list_empty(&ctx
->pinned_groups
) ||
10100 !list_empty(&ctx
->flexible_groups
))
10103 mutex_unlock(&ctx
->mutex
);
10109 void perf_event_delayed_put(struct task_struct
*task
)
10113 for_each_task_context_nr(ctxn
)
10114 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10117 struct file
*perf_event_get(unsigned int fd
)
10121 file
= fget_raw(fd
);
10123 return ERR_PTR(-EBADF
);
10125 if (file
->f_op
!= &perf_fops
) {
10127 return ERR_PTR(-EBADF
);
10133 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10136 return ERR_PTR(-EINVAL
);
10138 return &event
->attr
;
10142 * inherit a event from parent task to child task:
10144 static struct perf_event
*
10145 inherit_event(struct perf_event
*parent_event
,
10146 struct task_struct
*parent
,
10147 struct perf_event_context
*parent_ctx
,
10148 struct task_struct
*child
,
10149 struct perf_event
*group_leader
,
10150 struct perf_event_context
*child_ctx
)
10152 enum perf_event_active_state parent_state
= parent_event
->state
;
10153 struct perf_event
*child_event
;
10154 unsigned long flags
;
10157 * Instead of creating recursive hierarchies of events,
10158 * we link inherited events back to the original parent,
10159 * which has a filp for sure, which we use as the reference
10162 if (parent_event
->parent
)
10163 parent_event
= parent_event
->parent
;
10165 child_event
= perf_event_alloc(&parent_event
->attr
,
10168 group_leader
, parent_event
,
10170 if (IS_ERR(child_event
))
10171 return child_event
;
10174 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10175 * must be under the same lock in order to serialize against
10176 * perf_event_release_kernel(), such that either we must observe
10177 * is_orphaned_event() or they will observe us on the child_list.
10179 mutex_lock(&parent_event
->child_mutex
);
10180 if (is_orphaned_event(parent_event
) ||
10181 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10182 mutex_unlock(&parent_event
->child_mutex
);
10183 free_event(child_event
);
10187 get_ctx(child_ctx
);
10190 * Make the child state follow the state of the parent event,
10191 * not its attr.disabled bit. We hold the parent's mutex,
10192 * so we won't race with perf_event_{en, dis}able_family.
10194 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10195 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10197 child_event
->state
= PERF_EVENT_STATE_OFF
;
10199 if (parent_event
->attr
.freq
) {
10200 u64 sample_period
= parent_event
->hw
.sample_period
;
10201 struct hw_perf_event
*hwc
= &child_event
->hw
;
10203 hwc
->sample_period
= sample_period
;
10204 hwc
->last_period
= sample_period
;
10206 local64_set(&hwc
->period_left
, sample_period
);
10209 child_event
->ctx
= child_ctx
;
10210 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10211 child_event
->overflow_handler_context
10212 = parent_event
->overflow_handler_context
;
10215 * Precalculate sample_data sizes
10217 perf_event__header_size(child_event
);
10218 perf_event__id_header_size(child_event
);
10221 * Link it up in the child's context:
10223 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10224 add_event_to_ctx(child_event
, child_ctx
);
10225 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10228 * Link this into the parent event's child list
10230 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10231 mutex_unlock(&parent_event
->child_mutex
);
10233 return child_event
;
10236 static int inherit_group(struct perf_event
*parent_event
,
10237 struct task_struct
*parent
,
10238 struct perf_event_context
*parent_ctx
,
10239 struct task_struct
*child
,
10240 struct perf_event_context
*child_ctx
)
10242 struct perf_event
*leader
;
10243 struct perf_event
*sub
;
10244 struct perf_event
*child_ctr
;
10246 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10247 child
, NULL
, child_ctx
);
10248 if (IS_ERR(leader
))
10249 return PTR_ERR(leader
);
10250 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10251 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10252 child
, leader
, child_ctx
);
10253 if (IS_ERR(child_ctr
))
10254 return PTR_ERR(child_ctr
);
10260 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10261 struct perf_event_context
*parent_ctx
,
10262 struct task_struct
*child
, int ctxn
,
10263 int *inherited_all
)
10266 struct perf_event_context
*child_ctx
;
10268 if (!event
->attr
.inherit
) {
10269 *inherited_all
= 0;
10273 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10276 * This is executed from the parent task context, so
10277 * inherit events that have been marked for cloning.
10278 * First allocate and initialize a context for the
10282 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10286 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10289 ret
= inherit_group(event
, parent
, parent_ctx
,
10293 *inherited_all
= 0;
10299 * Initialize the perf_event context in task_struct
10301 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10303 struct perf_event_context
*child_ctx
, *parent_ctx
;
10304 struct perf_event_context
*cloned_ctx
;
10305 struct perf_event
*event
;
10306 struct task_struct
*parent
= current
;
10307 int inherited_all
= 1;
10308 unsigned long flags
;
10311 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10315 * If the parent's context is a clone, pin it so it won't get
10316 * swapped under us.
10318 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10323 * No need to check if parent_ctx != NULL here; since we saw
10324 * it non-NULL earlier, the only reason for it to become NULL
10325 * is if we exit, and since we're currently in the middle of
10326 * a fork we can't be exiting at the same time.
10330 * Lock the parent list. No need to lock the child - not PID
10331 * hashed yet and not running, so nobody can access it.
10333 mutex_lock(&parent_ctx
->mutex
);
10336 * We dont have to disable NMIs - we are only looking at
10337 * the list, not manipulating it:
10339 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10340 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10341 child
, ctxn
, &inherited_all
);
10347 * We can't hold ctx->lock when iterating the ->flexible_group list due
10348 * to allocations, but we need to prevent rotation because
10349 * rotate_ctx() will change the list from interrupt context.
10351 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10352 parent_ctx
->rotate_disable
= 1;
10353 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10355 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10356 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10357 child
, ctxn
, &inherited_all
);
10362 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10363 parent_ctx
->rotate_disable
= 0;
10365 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10367 if (child_ctx
&& inherited_all
) {
10369 * Mark the child context as a clone of the parent
10370 * context, or of whatever the parent is a clone of.
10372 * Note that if the parent is a clone, the holding of
10373 * parent_ctx->lock avoids it from being uncloned.
10375 cloned_ctx
= parent_ctx
->parent_ctx
;
10377 child_ctx
->parent_ctx
= cloned_ctx
;
10378 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
10380 child_ctx
->parent_ctx
= parent_ctx
;
10381 child_ctx
->parent_gen
= parent_ctx
->generation
;
10383 get_ctx(child_ctx
->parent_ctx
);
10386 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10387 mutex_unlock(&parent_ctx
->mutex
);
10389 perf_unpin_context(parent_ctx
);
10390 put_ctx(parent_ctx
);
10396 * Initialize the perf_event context in task_struct
10398 int perf_event_init_task(struct task_struct
*child
)
10402 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
10403 mutex_init(&child
->perf_event_mutex
);
10404 INIT_LIST_HEAD(&child
->perf_event_list
);
10406 for_each_task_context_nr(ctxn
) {
10407 ret
= perf_event_init_context(child
, ctxn
);
10409 perf_event_free_task(child
);
10417 static void __init
perf_event_init_all_cpus(void)
10419 struct swevent_htable
*swhash
;
10422 for_each_possible_cpu(cpu
) {
10423 swhash
= &per_cpu(swevent_htable
, cpu
);
10424 mutex_init(&swhash
->hlist_mutex
);
10425 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
10427 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
10428 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
10432 int perf_event_init_cpu(unsigned int cpu
)
10434 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
10436 mutex_lock(&swhash
->hlist_mutex
);
10437 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
10438 struct swevent_hlist
*hlist
;
10440 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
10442 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
10444 mutex_unlock(&swhash
->hlist_mutex
);
10448 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
10449 static void __perf_event_exit_context(void *__info
)
10451 struct perf_event_context
*ctx
= __info
;
10452 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
10453 struct perf_event
*event
;
10455 raw_spin_lock(&ctx
->lock
);
10456 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
10457 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
10458 raw_spin_unlock(&ctx
->lock
);
10461 static void perf_event_exit_cpu_context(int cpu
)
10463 struct perf_event_context
*ctx
;
10467 idx
= srcu_read_lock(&pmus_srcu
);
10468 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
10469 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
10471 mutex_lock(&ctx
->mutex
);
10472 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
10473 mutex_unlock(&ctx
->mutex
);
10475 srcu_read_unlock(&pmus_srcu
, idx
);
10479 static void perf_event_exit_cpu_context(int cpu
) { }
10483 int perf_event_exit_cpu(unsigned int cpu
)
10485 perf_event_exit_cpu_context(cpu
);
10490 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
10494 for_each_online_cpu(cpu
)
10495 perf_event_exit_cpu(cpu
);
10501 * Run the perf reboot notifier at the very last possible moment so that
10502 * the generic watchdog code runs as long as possible.
10504 static struct notifier_block perf_reboot_notifier
= {
10505 .notifier_call
= perf_reboot
,
10506 .priority
= INT_MIN
,
10509 void __init
perf_event_init(void)
10513 idr_init(&pmu_idr
);
10515 perf_event_init_all_cpus();
10516 init_srcu_struct(&pmus_srcu
);
10517 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
10518 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
10519 perf_pmu_register(&perf_task_clock
, NULL
, -1);
10520 perf_tp_register();
10521 perf_event_init_cpu(smp_processor_id());
10522 register_reboot_notifier(&perf_reboot_notifier
);
10524 ret
= init_hw_breakpoint();
10525 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
10528 * Build time assertion that we keep the data_head at the intended
10529 * location. IOW, validation we got the __reserved[] size right.
10531 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
10535 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
10538 struct perf_pmu_events_attr
*pmu_attr
=
10539 container_of(attr
, struct perf_pmu_events_attr
, attr
);
10541 if (pmu_attr
->event_str
)
10542 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
10546 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
10548 static int __init
perf_event_sysfs_init(void)
10553 mutex_lock(&pmus_lock
);
10555 ret
= bus_register(&pmu_bus
);
10559 list_for_each_entry(pmu
, &pmus
, entry
) {
10560 if (!pmu
->name
|| pmu
->type
< 0)
10563 ret
= pmu_dev_alloc(pmu
);
10564 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
10566 pmu_bus_running
= 1;
10570 mutex_unlock(&pmus_lock
);
10574 device_initcall(perf_event_sysfs_init
);
10576 #ifdef CONFIG_CGROUP_PERF
10577 static struct cgroup_subsys_state
*
10578 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
10580 struct perf_cgroup
*jc
;
10582 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
10584 return ERR_PTR(-ENOMEM
);
10586 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
10589 return ERR_PTR(-ENOMEM
);
10595 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
10597 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
10599 free_percpu(jc
->info
);
10603 static int __perf_cgroup_move(void *info
)
10605 struct task_struct
*task
= info
;
10607 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
10612 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
10614 struct task_struct
*task
;
10615 struct cgroup_subsys_state
*css
;
10617 cgroup_taskset_for_each(task
, css
, tset
)
10618 task_function_call(task
, __perf_cgroup_move
, task
);
10621 struct cgroup_subsys perf_event_cgrp_subsys
= {
10622 .css_alloc
= perf_cgroup_css_alloc
,
10623 .css_free
= perf_cgroup_css_free
,
10624 .attach
= perf_cgroup_attach
,
10626 #endif /* CONFIG_CGROUP_PERF */