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
);
907 * cpuctx->cgrp is NULL until a cgroup event is sched in or
908 * ctx->nr_cgroup == 0 .
910 if (add
&& perf_cgroup_from_task(current
, ctx
) == event
->cgrp
)
911 cpuctx
->cgrp
= event
->cgrp
;
916 #else /* !CONFIG_CGROUP_PERF */
919 perf_cgroup_match(struct perf_event
*event
)
924 static inline void perf_detach_cgroup(struct perf_event
*event
)
927 static inline int is_cgroup_event(struct perf_event
*event
)
932 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
937 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
941 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
945 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
946 struct task_struct
*next
)
950 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
951 struct task_struct
*task
)
955 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
956 struct perf_event_attr
*attr
,
957 struct perf_event
*group_leader
)
963 perf_cgroup_set_timestamp(struct task_struct
*task
,
964 struct perf_event_context
*ctx
)
969 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
974 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
978 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
984 perf_cgroup_defer_enabled(struct perf_event
*event
)
989 perf_cgroup_mark_enabled(struct perf_event
*event
,
990 struct perf_event_context
*ctx
)
995 list_update_cgroup_event(struct perf_event
*event
,
996 struct perf_event_context
*ctx
, bool add
)
1003 * set default to be dependent on timer tick just
1004 * like original code
1006 #define PERF_CPU_HRTIMER (1000 / HZ)
1008 * function must be called with interrupts disbled
1010 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1012 struct perf_cpu_context
*cpuctx
;
1015 WARN_ON(!irqs_disabled());
1017 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1018 rotations
= perf_rotate_context(cpuctx
);
1020 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1022 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1024 cpuctx
->hrtimer_active
= 0;
1025 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1027 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1030 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1032 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1033 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1036 /* no multiplexing needed for SW PMU */
1037 if (pmu
->task_ctx_nr
== perf_sw_context
)
1041 * check default is sane, if not set then force to
1042 * default interval (1/tick)
1044 interval
= pmu
->hrtimer_interval_ms
;
1046 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1048 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1050 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1051 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1052 timer
->function
= perf_mux_hrtimer_handler
;
1055 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1057 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1058 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1059 unsigned long flags
;
1061 /* not for SW PMU */
1062 if (pmu
->task_ctx_nr
== perf_sw_context
)
1065 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1066 if (!cpuctx
->hrtimer_active
) {
1067 cpuctx
->hrtimer_active
= 1;
1068 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1069 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1071 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1076 void perf_pmu_disable(struct pmu
*pmu
)
1078 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1080 pmu
->pmu_disable(pmu
);
1083 void perf_pmu_enable(struct pmu
*pmu
)
1085 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1087 pmu
->pmu_enable(pmu
);
1090 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1093 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1094 * perf_event_task_tick() are fully serialized because they're strictly cpu
1095 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1096 * disabled, while perf_event_task_tick is called from IRQ context.
1098 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1100 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1102 WARN_ON(!irqs_disabled());
1104 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1106 list_add(&ctx
->active_ctx_list
, head
);
1109 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1111 WARN_ON(!irqs_disabled());
1113 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1115 list_del_init(&ctx
->active_ctx_list
);
1118 static void get_ctx(struct perf_event_context
*ctx
)
1120 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1123 static void free_ctx(struct rcu_head
*head
)
1125 struct perf_event_context
*ctx
;
1127 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1128 kfree(ctx
->task_ctx_data
);
1132 static void put_ctx(struct perf_event_context
*ctx
)
1134 if (atomic_dec_and_test(&ctx
->refcount
)) {
1135 if (ctx
->parent_ctx
)
1136 put_ctx(ctx
->parent_ctx
);
1137 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1138 put_task_struct(ctx
->task
);
1139 call_rcu(&ctx
->rcu_head
, free_ctx
);
1144 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1145 * perf_pmu_migrate_context() we need some magic.
1147 * Those places that change perf_event::ctx will hold both
1148 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1150 * Lock ordering is by mutex address. There are two other sites where
1151 * perf_event_context::mutex nests and those are:
1153 * - perf_event_exit_task_context() [ child , 0 ]
1154 * perf_event_exit_event()
1155 * put_event() [ parent, 1 ]
1157 * - perf_event_init_context() [ parent, 0 ]
1158 * inherit_task_group()
1161 * perf_event_alloc()
1163 * perf_try_init_event() [ child , 1 ]
1165 * While it appears there is an obvious deadlock here -- the parent and child
1166 * nesting levels are inverted between the two. This is in fact safe because
1167 * life-time rules separate them. That is an exiting task cannot fork, and a
1168 * spawning task cannot (yet) exit.
1170 * But remember that that these are parent<->child context relations, and
1171 * migration does not affect children, therefore these two orderings should not
1174 * The change in perf_event::ctx does not affect children (as claimed above)
1175 * because the sys_perf_event_open() case will install a new event and break
1176 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1177 * concerned with cpuctx and that doesn't have children.
1179 * The places that change perf_event::ctx will issue:
1181 * perf_remove_from_context();
1182 * synchronize_rcu();
1183 * perf_install_in_context();
1185 * to affect the change. The remove_from_context() + synchronize_rcu() should
1186 * quiesce the event, after which we can install it in the new location. This
1187 * means that only external vectors (perf_fops, prctl) can perturb the event
1188 * while in transit. Therefore all such accessors should also acquire
1189 * perf_event_context::mutex to serialize against this.
1191 * However; because event->ctx can change while we're waiting to acquire
1192 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1197 * task_struct::perf_event_mutex
1198 * perf_event_context::mutex
1199 * perf_event::child_mutex;
1200 * perf_event_context::lock
1201 * perf_event::mmap_mutex
1204 static struct perf_event_context
*
1205 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1207 struct perf_event_context
*ctx
;
1211 ctx
= ACCESS_ONCE(event
->ctx
);
1212 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1218 mutex_lock_nested(&ctx
->mutex
, nesting
);
1219 if (event
->ctx
!= ctx
) {
1220 mutex_unlock(&ctx
->mutex
);
1228 static inline struct perf_event_context
*
1229 perf_event_ctx_lock(struct perf_event
*event
)
1231 return perf_event_ctx_lock_nested(event
, 0);
1234 static void perf_event_ctx_unlock(struct perf_event
*event
,
1235 struct perf_event_context
*ctx
)
1237 mutex_unlock(&ctx
->mutex
);
1242 * This must be done under the ctx->lock, such as to serialize against
1243 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1244 * calling scheduler related locks and ctx->lock nests inside those.
1246 static __must_check
struct perf_event_context
*
1247 unclone_ctx(struct perf_event_context
*ctx
)
1249 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1251 lockdep_assert_held(&ctx
->lock
);
1254 ctx
->parent_ctx
= NULL
;
1260 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1263 * only top level events have the pid namespace they were created in
1266 event
= event
->parent
;
1268 return task_tgid_nr_ns(p
, event
->ns
);
1271 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1274 * only top level events have the pid namespace they were created in
1277 event
= event
->parent
;
1279 return task_pid_nr_ns(p
, event
->ns
);
1283 * If we inherit events we want to return the parent event id
1286 static u64
primary_event_id(struct perf_event
*event
)
1291 id
= event
->parent
->id
;
1297 * Get the perf_event_context for a task and lock it.
1299 * This has to cope with with the fact that until it is locked,
1300 * the context could get moved to another task.
1302 static struct perf_event_context
*
1303 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1305 struct perf_event_context
*ctx
;
1309 * One of the few rules of preemptible RCU is that one cannot do
1310 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1311 * part of the read side critical section was irqs-enabled -- see
1312 * rcu_read_unlock_special().
1314 * Since ctx->lock nests under rq->lock we must ensure the entire read
1315 * side critical section has interrupts disabled.
1317 local_irq_save(*flags
);
1319 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1322 * If this context is a clone of another, it might
1323 * get swapped for another underneath us by
1324 * perf_event_task_sched_out, though the
1325 * rcu_read_lock() protects us from any context
1326 * getting freed. Lock the context and check if it
1327 * got swapped before we could get the lock, and retry
1328 * if so. If we locked the right context, then it
1329 * can't get swapped on us any more.
1331 raw_spin_lock(&ctx
->lock
);
1332 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1333 raw_spin_unlock(&ctx
->lock
);
1335 local_irq_restore(*flags
);
1339 if (ctx
->task
== TASK_TOMBSTONE
||
1340 !atomic_inc_not_zero(&ctx
->refcount
)) {
1341 raw_spin_unlock(&ctx
->lock
);
1344 WARN_ON_ONCE(ctx
->task
!= task
);
1349 local_irq_restore(*flags
);
1354 * Get the context for a task and increment its pin_count so it
1355 * can't get swapped to another task. This also increments its
1356 * reference count so that the context can't get freed.
1358 static struct perf_event_context
*
1359 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1361 struct perf_event_context
*ctx
;
1362 unsigned long flags
;
1364 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1367 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1372 static void perf_unpin_context(struct perf_event_context
*ctx
)
1374 unsigned long flags
;
1376 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1378 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1382 * Update the record of the current time in a context.
1384 static void update_context_time(struct perf_event_context
*ctx
)
1386 u64 now
= perf_clock();
1388 ctx
->time
+= now
- ctx
->timestamp
;
1389 ctx
->timestamp
= now
;
1392 static u64
perf_event_time(struct perf_event
*event
)
1394 struct perf_event_context
*ctx
= event
->ctx
;
1396 if (is_cgroup_event(event
))
1397 return perf_cgroup_event_time(event
);
1399 return ctx
? ctx
->time
: 0;
1403 * Update the total_time_enabled and total_time_running fields for a event.
1405 static void update_event_times(struct perf_event
*event
)
1407 struct perf_event_context
*ctx
= event
->ctx
;
1410 lockdep_assert_held(&ctx
->lock
);
1412 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1413 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1417 * in cgroup mode, time_enabled represents
1418 * the time the event was enabled AND active
1419 * tasks were in the monitored cgroup. This is
1420 * independent of the activity of the context as
1421 * there may be a mix of cgroup and non-cgroup events.
1423 * That is why we treat cgroup events differently
1426 if (is_cgroup_event(event
))
1427 run_end
= perf_cgroup_event_time(event
);
1428 else if (ctx
->is_active
)
1429 run_end
= ctx
->time
;
1431 run_end
= event
->tstamp_stopped
;
1433 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1435 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1436 run_end
= event
->tstamp_stopped
;
1438 run_end
= perf_event_time(event
);
1440 event
->total_time_running
= run_end
- event
->tstamp_running
;
1445 * Update total_time_enabled and total_time_running for all events in a group.
1447 static void update_group_times(struct perf_event
*leader
)
1449 struct perf_event
*event
;
1451 update_event_times(leader
);
1452 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1453 update_event_times(event
);
1456 static struct list_head
*
1457 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1459 if (event
->attr
.pinned
)
1460 return &ctx
->pinned_groups
;
1462 return &ctx
->flexible_groups
;
1466 * Add a event from the lists for its context.
1467 * Must be called with ctx->mutex and ctx->lock held.
1470 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1473 lockdep_assert_held(&ctx
->lock
);
1475 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1476 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1479 * If we're a stand alone event or group leader, we go to the context
1480 * list, group events are kept attached to the group so that
1481 * perf_group_detach can, at all times, locate all siblings.
1483 if (event
->group_leader
== event
) {
1484 struct list_head
*list
;
1486 event
->group_caps
= event
->event_caps
;
1488 list
= ctx_group_list(event
, ctx
);
1489 list_add_tail(&event
->group_entry
, list
);
1492 list_update_cgroup_event(event
, ctx
, true);
1494 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1496 if (event
->attr
.inherit_stat
)
1503 * Initialize event state based on the perf_event_attr::disabled.
1505 static inline void perf_event__state_init(struct perf_event
*event
)
1507 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1508 PERF_EVENT_STATE_INACTIVE
;
1511 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1513 int entry
= sizeof(u64
); /* value */
1517 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1518 size
+= sizeof(u64
);
1520 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1521 size
+= sizeof(u64
);
1523 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1524 entry
+= sizeof(u64
);
1526 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1528 size
+= sizeof(u64
);
1532 event
->read_size
= size
;
1535 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1537 struct perf_sample_data
*data
;
1540 if (sample_type
& PERF_SAMPLE_IP
)
1541 size
+= sizeof(data
->ip
);
1543 if (sample_type
& PERF_SAMPLE_ADDR
)
1544 size
+= sizeof(data
->addr
);
1546 if (sample_type
& PERF_SAMPLE_PERIOD
)
1547 size
+= sizeof(data
->period
);
1549 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1550 size
+= sizeof(data
->weight
);
1552 if (sample_type
& PERF_SAMPLE_READ
)
1553 size
+= event
->read_size
;
1555 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1556 size
+= sizeof(data
->data_src
.val
);
1558 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1559 size
+= sizeof(data
->txn
);
1561 event
->header_size
= size
;
1565 * Called at perf_event creation and when events are attached/detached from a
1568 static void perf_event__header_size(struct perf_event
*event
)
1570 __perf_event_read_size(event
,
1571 event
->group_leader
->nr_siblings
);
1572 __perf_event_header_size(event
, event
->attr
.sample_type
);
1575 static void perf_event__id_header_size(struct perf_event
*event
)
1577 struct perf_sample_data
*data
;
1578 u64 sample_type
= event
->attr
.sample_type
;
1581 if (sample_type
& PERF_SAMPLE_TID
)
1582 size
+= sizeof(data
->tid_entry
);
1584 if (sample_type
& PERF_SAMPLE_TIME
)
1585 size
+= sizeof(data
->time
);
1587 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1588 size
+= sizeof(data
->id
);
1590 if (sample_type
& PERF_SAMPLE_ID
)
1591 size
+= sizeof(data
->id
);
1593 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1594 size
+= sizeof(data
->stream_id
);
1596 if (sample_type
& PERF_SAMPLE_CPU
)
1597 size
+= sizeof(data
->cpu_entry
);
1599 event
->id_header_size
= size
;
1602 static bool perf_event_validate_size(struct perf_event
*event
)
1605 * The values computed here will be over-written when we actually
1608 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1609 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1610 perf_event__id_header_size(event
);
1613 * Sum the lot; should not exceed the 64k limit we have on records.
1614 * Conservative limit to allow for callchains and other variable fields.
1616 if (event
->read_size
+ event
->header_size
+
1617 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1623 static void perf_group_attach(struct perf_event
*event
)
1625 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1628 * We can have double attach due to group movement in perf_event_open.
1630 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1633 event
->attach_state
|= PERF_ATTACH_GROUP
;
1635 if (group_leader
== event
)
1638 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1640 group_leader
->group_caps
&= event
->event_caps
;
1642 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1643 group_leader
->nr_siblings
++;
1645 perf_event__header_size(group_leader
);
1647 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1648 perf_event__header_size(pos
);
1652 * Remove a event from the lists for its context.
1653 * Must be called with ctx->mutex and ctx->lock held.
1656 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1658 WARN_ON_ONCE(event
->ctx
!= ctx
);
1659 lockdep_assert_held(&ctx
->lock
);
1662 * We can have double detach due to exit/hot-unplug + close.
1664 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1667 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1669 list_update_cgroup_event(event
, ctx
, false);
1672 if (event
->attr
.inherit_stat
)
1675 list_del_rcu(&event
->event_entry
);
1677 if (event
->group_leader
== event
)
1678 list_del_init(&event
->group_entry
);
1680 update_group_times(event
);
1683 * If event was in error state, then keep it
1684 * that way, otherwise bogus counts will be
1685 * returned on read(). The only way to get out
1686 * of error state is by explicit re-enabling
1689 if (event
->state
> PERF_EVENT_STATE_OFF
)
1690 event
->state
= PERF_EVENT_STATE_OFF
;
1695 static void perf_group_detach(struct perf_event
*event
)
1697 struct perf_event
*sibling
, *tmp
;
1698 struct list_head
*list
= NULL
;
1701 * We can have double detach due to exit/hot-unplug + close.
1703 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1706 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1709 * If this is a sibling, remove it from its group.
1711 if (event
->group_leader
!= event
) {
1712 list_del_init(&event
->group_entry
);
1713 event
->group_leader
->nr_siblings
--;
1717 if (!list_empty(&event
->group_entry
))
1718 list
= &event
->group_entry
;
1721 * If this was a group event with sibling events then
1722 * upgrade the siblings to singleton events by adding them
1723 * to whatever list we are on.
1725 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1727 list_move_tail(&sibling
->group_entry
, list
);
1728 sibling
->group_leader
= sibling
;
1730 /* Inherit group flags from the previous leader */
1731 sibling
->group_caps
= event
->group_caps
;
1733 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1737 perf_event__header_size(event
->group_leader
);
1739 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1740 perf_event__header_size(tmp
);
1743 static bool is_orphaned_event(struct perf_event
*event
)
1745 return event
->state
== PERF_EVENT_STATE_DEAD
;
1748 static inline int __pmu_filter_match(struct perf_event
*event
)
1750 struct pmu
*pmu
= event
->pmu
;
1751 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1755 * Check whether we should attempt to schedule an event group based on
1756 * PMU-specific filtering. An event group can consist of HW and SW events,
1757 * potentially with a SW leader, so we must check all the filters, to
1758 * determine whether a group is schedulable:
1760 static inline int pmu_filter_match(struct perf_event
*event
)
1762 struct perf_event
*child
;
1764 if (!__pmu_filter_match(event
))
1767 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1768 if (!__pmu_filter_match(child
))
1776 event_filter_match(struct perf_event
*event
)
1778 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1779 perf_cgroup_match(event
) && pmu_filter_match(event
);
1783 event_sched_out(struct perf_event
*event
,
1784 struct perf_cpu_context
*cpuctx
,
1785 struct perf_event_context
*ctx
)
1787 u64 tstamp
= perf_event_time(event
);
1790 WARN_ON_ONCE(event
->ctx
!= ctx
);
1791 lockdep_assert_held(&ctx
->lock
);
1794 * An event which could not be activated because of
1795 * filter mismatch still needs to have its timings
1796 * maintained, otherwise bogus information is return
1797 * via read() for time_enabled, time_running:
1799 if (event
->state
== PERF_EVENT_STATE_INACTIVE
&&
1800 !event_filter_match(event
)) {
1801 delta
= tstamp
- event
->tstamp_stopped
;
1802 event
->tstamp_running
+= delta
;
1803 event
->tstamp_stopped
= tstamp
;
1806 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1809 perf_pmu_disable(event
->pmu
);
1811 event
->tstamp_stopped
= tstamp
;
1812 event
->pmu
->del(event
, 0);
1814 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1815 if (event
->pending_disable
) {
1816 event
->pending_disable
= 0;
1817 event
->state
= PERF_EVENT_STATE_OFF
;
1820 if (!is_software_event(event
))
1821 cpuctx
->active_oncpu
--;
1822 if (!--ctx
->nr_active
)
1823 perf_event_ctx_deactivate(ctx
);
1824 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1826 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1827 cpuctx
->exclusive
= 0;
1829 perf_pmu_enable(event
->pmu
);
1833 group_sched_out(struct perf_event
*group_event
,
1834 struct perf_cpu_context
*cpuctx
,
1835 struct perf_event_context
*ctx
)
1837 struct perf_event
*event
;
1838 int state
= group_event
->state
;
1840 perf_pmu_disable(ctx
->pmu
);
1842 event_sched_out(group_event
, cpuctx
, ctx
);
1845 * Schedule out siblings (if any):
1847 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1848 event_sched_out(event
, cpuctx
, ctx
);
1850 perf_pmu_enable(ctx
->pmu
);
1852 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1853 cpuctx
->exclusive
= 0;
1856 #define DETACH_GROUP 0x01UL
1859 * Cross CPU call to remove a performance event
1861 * We disable the event on the hardware level first. After that we
1862 * remove it from the context list.
1865 __perf_remove_from_context(struct perf_event
*event
,
1866 struct perf_cpu_context
*cpuctx
,
1867 struct perf_event_context
*ctx
,
1870 unsigned long flags
= (unsigned long)info
;
1872 event_sched_out(event
, cpuctx
, ctx
);
1873 if (flags
& DETACH_GROUP
)
1874 perf_group_detach(event
);
1875 list_del_event(event
, ctx
);
1877 if (!ctx
->nr_events
&& ctx
->is_active
) {
1880 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1881 cpuctx
->task_ctx
= NULL
;
1887 * Remove the event from a task's (or a CPU's) list of events.
1889 * If event->ctx is a cloned context, callers must make sure that
1890 * every task struct that event->ctx->task could possibly point to
1891 * remains valid. This is OK when called from perf_release since
1892 * that only calls us on the top-level context, which can't be a clone.
1893 * When called from perf_event_exit_task, it's OK because the
1894 * context has been detached from its task.
1896 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1898 lockdep_assert_held(&event
->ctx
->mutex
);
1900 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1904 * Cross CPU call to disable a performance event
1906 static void __perf_event_disable(struct perf_event
*event
,
1907 struct perf_cpu_context
*cpuctx
,
1908 struct perf_event_context
*ctx
,
1911 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1914 update_context_time(ctx
);
1915 update_cgrp_time_from_event(event
);
1916 update_group_times(event
);
1917 if (event
== event
->group_leader
)
1918 group_sched_out(event
, cpuctx
, ctx
);
1920 event_sched_out(event
, cpuctx
, ctx
);
1921 event
->state
= PERF_EVENT_STATE_OFF
;
1927 * If event->ctx is a cloned context, callers must make sure that
1928 * every task struct that event->ctx->task could possibly point to
1929 * remains valid. This condition is satisifed when called through
1930 * perf_event_for_each_child or perf_event_for_each because they
1931 * hold the top-level event's child_mutex, so any descendant that
1932 * goes to exit will block in perf_event_exit_event().
1934 * When called from perf_pending_event it's OK because event->ctx
1935 * is the current context on this CPU and preemption is disabled,
1936 * hence we can't get into perf_event_task_sched_out for this context.
1938 static void _perf_event_disable(struct perf_event
*event
)
1940 struct perf_event_context
*ctx
= event
->ctx
;
1942 raw_spin_lock_irq(&ctx
->lock
);
1943 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1944 raw_spin_unlock_irq(&ctx
->lock
);
1947 raw_spin_unlock_irq(&ctx
->lock
);
1949 event_function_call(event
, __perf_event_disable
, NULL
);
1952 void perf_event_disable_local(struct perf_event
*event
)
1954 event_function_local(event
, __perf_event_disable
, NULL
);
1958 * Strictly speaking kernel users cannot create groups and therefore this
1959 * interface does not need the perf_event_ctx_lock() magic.
1961 void perf_event_disable(struct perf_event
*event
)
1963 struct perf_event_context
*ctx
;
1965 ctx
= perf_event_ctx_lock(event
);
1966 _perf_event_disable(event
);
1967 perf_event_ctx_unlock(event
, ctx
);
1969 EXPORT_SYMBOL_GPL(perf_event_disable
);
1971 void perf_event_disable_inatomic(struct perf_event
*event
)
1973 event
->pending_disable
= 1;
1974 irq_work_queue(&event
->pending
);
1977 static void perf_set_shadow_time(struct perf_event
*event
,
1978 struct perf_event_context
*ctx
,
1982 * use the correct time source for the time snapshot
1984 * We could get by without this by leveraging the
1985 * fact that to get to this function, the caller
1986 * has most likely already called update_context_time()
1987 * and update_cgrp_time_xx() and thus both timestamp
1988 * are identical (or very close). Given that tstamp is,
1989 * already adjusted for cgroup, we could say that:
1990 * tstamp - ctx->timestamp
1992 * tstamp - cgrp->timestamp.
1994 * Then, in perf_output_read(), the calculation would
1995 * work with no changes because:
1996 * - event is guaranteed scheduled in
1997 * - no scheduled out in between
1998 * - thus the timestamp would be the same
2000 * But this is a bit hairy.
2002 * So instead, we have an explicit cgroup call to remain
2003 * within the time time source all along. We believe it
2004 * is cleaner and simpler to understand.
2006 if (is_cgroup_event(event
))
2007 perf_cgroup_set_shadow_time(event
, tstamp
);
2009 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
2012 #define MAX_INTERRUPTS (~0ULL)
2014 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2015 static void perf_log_itrace_start(struct perf_event
*event
);
2018 event_sched_in(struct perf_event
*event
,
2019 struct perf_cpu_context
*cpuctx
,
2020 struct perf_event_context
*ctx
)
2022 u64 tstamp
= perf_event_time(event
);
2025 lockdep_assert_held(&ctx
->lock
);
2027 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2030 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2032 * Order event::oncpu write to happen before the ACTIVE state
2036 WRITE_ONCE(event
->state
, PERF_EVENT_STATE_ACTIVE
);
2039 * Unthrottle events, since we scheduled we might have missed several
2040 * ticks already, also for a heavily scheduling task there is little
2041 * guarantee it'll get a tick in a timely manner.
2043 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2044 perf_log_throttle(event
, 1);
2045 event
->hw
.interrupts
= 0;
2049 * The new state must be visible before we turn it on in the hardware:
2053 perf_pmu_disable(event
->pmu
);
2055 perf_set_shadow_time(event
, ctx
, tstamp
);
2057 perf_log_itrace_start(event
);
2059 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2060 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2066 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
2068 if (!is_software_event(event
))
2069 cpuctx
->active_oncpu
++;
2070 if (!ctx
->nr_active
++)
2071 perf_event_ctx_activate(ctx
);
2072 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2075 if (event
->attr
.exclusive
)
2076 cpuctx
->exclusive
= 1;
2079 perf_pmu_enable(event
->pmu
);
2085 group_sched_in(struct perf_event
*group_event
,
2086 struct perf_cpu_context
*cpuctx
,
2087 struct perf_event_context
*ctx
)
2089 struct perf_event
*event
, *partial_group
= NULL
;
2090 struct pmu
*pmu
= ctx
->pmu
;
2091 u64 now
= ctx
->time
;
2092 bool simulate
= false;
2094 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2097 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2099 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2100 pmu
->cancel_txn(pmu
);
2101 perf_mux_hrtimer_restart(cpuctx
);
2106 * Schedule in siblings as one group (if any):
2108 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2109 if (event_sched_in(event
, cpuctx
, ctx
)) {
2110 partial_group
= event
;
2115 if (!pmu
->commit_txn(pmu
))
2120 * Groups can be scheduled in as one unit only, so undo any
2121 * partial group before returning:
2122 * The events up to the failed event are scheduled out normally,
2123 * tstamp_stopped will be updated.
2125 * The failed events and the remaining siblings need to have
2126 * their timings updated as if they had gone thru event_sched_in()
2127 * and event_sched_out(). This is required to get consistent timings
2128 * across the group. This also takes care of the case where the group
2129 * could never be scheduled by ensuring tstamp_stopped is set to mark
2130 * the time the event was actually stopped, such that time delta
2131 * calculation in update_event_times() is correct.
2133 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2134 if (event
== partial_group
)
2138 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2139 event
->tstamp_stopped
= now
;
2141 event_sched_out(event
, cpuctx
, ctx
);
2144 event_sched_out(group_event
, cpuctx
, ctx
);
2146 pmu
->cancel_txn(pmu
);
2148 perf_mux_hrtimer_restart(cpuctx
);
2154 * Work out whether we can put this event group on the CPU now.
2156 static int group_can_go_on(struct perf_event
*event
,
2157 struct perf_cpu_context
*cpuctx
,
2161 * Groups consisting entirely of software events can always go on.
2163 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2166 * If an exclusive group is already on, no other hardware
2169 if (cpuctx
->exclusive
)
2172 * If this group is exclusive and there are already
2173 * events on the CPU, it can't go on.
2175 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2178 * Otherwise, try to add it if all previous groups were able
2184 static void add_event_to_ctx(struct perf_event
*event
,
2185 struct perf_event_context
*ctx
)
2187 u64 tstamp
= perf_event_time(event
);
2189 list_add_event(event
, ctx
);
2190 perf_group_attach(event
);
2191 event
->tstamp_enabled
= tstamp
;
2192 event
->tstamp_running
= tstamp
;
2193 event
->tstamp_stopped
= tstamp
;
2196 static void ctx_sched_out(struct perf_event_context
*ctx
,
2197 struct perf_cpu_context
*cpuctx
,
2198 enum event_type_t event_type
);
2200 ctx_sched_in(struct perf_event_context
*ctx
,
2201 struct perf_cpu_context
*cpuctx
,
2202 enum event_type_t event_type
,
2203 struct task_struct
*task
);
2205 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2206 struct perf_event_context
*ctx
)
2208 if (!cpuctx
->task_ctx
)
2211 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2214 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2217 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2218 struct perf_event_context
*ctx
,
2219 struct task_struct
*task
)
2221 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2223 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2224 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2226 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2229 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2230 struct perf_event_context
*task_ctx
)
2232 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2234 task_ctx_sched_out(cpuctx
, task_ctx
);
2235 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2236 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2237 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2241 * Cross CPU call to install and enable a performance event
2243 * Very similar to remote_function() + event_function() but cannot assume that
2244 * things like ctx->is_active and cpuctx->task_ctx are set.
2246 static int __perf_install_in_context(void *info
)
2248 struct perf_event
*event
= info
;
2249 struct perf_event_context
*ctx
= event
->ctx
;
2250 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2251 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2252 bool reprogram
= true;
2255 raw_spin_lock(&cpuctx
->ctx
.lock
);
2257 raw_spin_lock(&ctx
->lock
);
2260 reprogram
= (ctx
->task
== current
);
2263 * If the task is running, it must be running on this CPU,
2264 * otherwise we cannot reprogram things.
2266 * If its not running, we don't care, ctx->lock will
2267 * serialize against it becoming runnable.
2269 if (task_curr(ctx
->task
) && !reprogram
) {
2274 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2275 } else if (task_ctx
) {
2276 raw_spin_lock(&task_ctx
->lock
);
2280 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2281 add_event_to_ctx(event
, ctx
);
2282 ctx_resched(cpuctx
, task_ctx
);
2284 add_event_to_ctx(event
, ctx
);
2288 perf_ctx_unlock(cpuctx
, task_ctx
);
2294 * Attach a performance event to a context.
2296 * Very similar to event_function_call, see comment there.
2299 perf_install_in_context(struct perf_event_context
*ctx
,
2300 struct perf_event
*event
,
2303 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2305 lockdep_assert_held(&ctx
->mutex
);
2307 if (event
->cpu
!= -1)
2311 * Ensures that if we can observe event->ctx, both the event and ctx
2312 * will be 'complete'. See perf_iterate_sb_cpu().
2314 smp_store_release(&event
->ctx
, ctx
);
2317 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2322 * Should not happen, we validate the ctx is still alive before calling.
2324 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2328 * Installing events is tricky because we cannot rely on ctx->is_active
2329 * to be set in case this is the nr_events 0 -> 1 transition.
2331 * Instead we use task_curr(), which tells us if the task is running.
2332 * However, since we use task_curr() outside of rq::lock, we can race
2333 * against the actual state. This means the result can be wrong.
2335 * If we get a false positive, we retry, this is harmless.
2337 * If we get a false negative, things are complicated. If we are after
2338 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2339 * value must be correct. If we're before, it doesn't matter since
2340 * perf_event_context_sched_in() will program the counter.
2342 * However, this hinges on the remote context switch having observed
2343 * our task->perf_event_ctxp[] store, such that it will in fact take
2344 * ctx::lock in perf_event_context_sched_in().
2346 * We do this by task_function_call(), if the IPI fails to hit the task
2347 * we know any future context switch of task must see the
2348 * perf_event_ctpx[] store.
2352 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2353 * task_cpu() load, such that if the IPI then does not find the task
2354 * running, a future context switch of that task must observe the
2359 if (!task_function_call(task
, __perf_install_in_context
, event
))
2362 raw_spin_lock_irq(&ctx
->lock
);
2364 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2366 * Cannot happen because we already checked above (which also
2367 * cannot happen), and we hold ctx->mutex, which serializes us
2368 * against perf_event_exit_task_context().
2370 raw_spin_unlock_irq(&ctx
->lock
);
2374 * If the task is not running, ctx->lock will avoid it becoming so,
2375 * thus we can safely install the event.
2377 if (task_curr(task
)) {
2378 raw_spin_unlock_irq(&ctx
->lock
);
2381 add_event_to_ctx(event
, ctx
);
2382 raw_spin_unlock_irq(&ctx
->lock
);
2386 * Put a event into inactive state and update time fields.
2387 * Enabling the leader of a group effectively enables all
2388 * the group members that aren't explicitly disabled, so we
2389 * have to update their ->tstamp_enabled also.
2390 * Note: this works for group members as well as group leaders
2391 * since the non-leader members' sibling_lists will be empty.
2393 static void __perf_event_mark_enabled(struct perf_event
*event
)
2395 struct perf_event
*sub
;
2396 u64 tstamp
= perf_event_time(event
);
2398 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2399 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2400 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2401 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2402 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2407 * Cross CPU call to enable a performance event
2409 static void __perf_event_enable(struct perf_event
*event
,
2410 struct perf_cpu_context
*cpuctx
,
2411 struct perf_event_context
*ctx
,
2414 struct perf_event
*leader
= event
->group_leader
;
2415 struct perf_event_context
*task_ctx
;
2417 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2418 event
->state
<= PERF_EVENT_STATE_ERROR
)
2422 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2424 __perf_event_mark_enabled(event
);
2426 if (!ctx
->is_active
)
2429 if (!event_filter_match(event
)) {
2430 if (is_cgroup_event(event
))
2431 perf_cgroup_defer_enabled(event
);
2432 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2437 * If the event is in a group and isn't the group leader,
2438 * then don't put it on unless the group is on.
2440 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2441 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2445 task_ctx
= cpuctx
->task_ctx
;
2447 WARN_ON_ONCE(task_ctx
!= ctx
);
2449 ctx_resched(cpuctx
, task_ctx
);
2455 * If event->ctx is a cloned context, callers must make sure that
2456 * every task struct that event->ctx->task could possibly point to
2457 * remains valid. This condition is satisfied when called through
2458 * perf_event_for_each_child or perf_event_for_each as described
2459 * for perf_event_disable.
2461 static void _perf_event_enable(struct perf_event
*event
)
2463 struct perf_event_context
*ctx
= event
->ctx
;
2465 raw_spin_lock_irq(&ctx
->lock
);
2466 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2467 event
->state
< PERF_EVENT_STATE_ERROR
) {
2468 raw_spin_unlock_irq(&ctx
->lock
);
2473 * If the event is in error state, clear that first.
2475 * That way, if we see the event in error state below, we know that it
2476 * has gone back into error state, as distinct from the task having
2477 * been scheduled away before the cross-call arrived.
2479 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2480 event
->state
= PERF_EVENT_STATE_OFF
;
2481 raw_spin_unlock_irq(&ctx
->lock
);
2483 event_function_call(event
, __perf_event_enable
, NULL
);
2487 * See perf_event_disable();
2489 void perf_event_enable(struct perf_event
*event
)
2491 struct perf_event_context
*ctx
;
2493 ctx
= perf_event_ctx_lock(event
);
2494 _perf_event_enable(event
);
2495 perf_event_ctx_unlock(event
, ctx
);
2497 EXPORT_SYMBOL_GPL(perf_event_enable
);
2499 struct stop_event_data
{
2500 struct perf_event
*event
;
2501 unsigned int restart
;
2504 static int __perf_event_stop(void *info
)
2506 struct stop_event_data
*sd
= info
;
2507 struct perf_event
*event
= sd
->event
;
2509 /* if it's already INACTIVE, do nothing */
2510 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2513 /* matches smp_wmb() in event_sched_in() */
2517 * There is a window with interrupts enabled before we get here,
2518 * so we need to check again lest we try to stop another CPU's event.
2520 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2523 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2526 * May race with the actual stop (through perf_pmu_output_stop()),
2527 * but it is only used for events with AUX ring buffer, and such
2528 * events will refuse to restart because of rb::aux_mmap_count==0,
2529 * see comments in perf_aux_output_begin().
2531 * Since this is happening on a event-local CPU, no trace is lost
2535 event
->pmu
->start(event
, 0);
2540 static int perf_event_stop(struct perf_event
*event
, int restart
)
2542 struct stop_event_data sd
= {
2549 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2552 /* matches smp_wmb() in event_sched_in() */
2556 * We only want to restart ACTIVE events, so if the event goes
2557 * inactive here (event->oncpu==-1), there's nothing more to do;
2558 * fall through with ret==-ENXIO.
2560 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2561 __perf_event_stop
, &sd
);
2562 } while (ret
== -EAGAIN
);
2568 * In order to contain the amount of racy and tricky in the address filter
2569 * configuration management, it is a two part process:
2571 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2572 * we update the addresses of corresponding vmas in
2573 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2574 * (p2) when an event is scheduled in (pmu::add), it calls
2575 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2576 * if the generation has changed since the previous call.
2578 * If (p1) happens while the event is active, we restart it to force (p2).
2580 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2581 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2583 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2584 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2586 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2589 void perf_event_addr_filters_sync(struct perf_event
*event
)
2591 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2593 if (!has_addr_filter(event
))
2596 raw_spin_lock(&ifh
->lock
);
2597 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2598 event
->pmu
->addr_filters_sync(event
);
2599 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2601 raw_spin_unlock(&ifh
->lock
);
2603 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2605 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2608 * not supported on inherited events
2610 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2613 atomic_add(refresh
, &event
->event_limit
);
2614 _perf_event_enable(event
);
2620 * See perf_event_disable()
2622 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2624 struct perf_event_context
*ctx
;
2627 ctx
= perf_event_ctx_lock(event
);
2628 ret
= _perf_event_refresh(event
, refresh
);
2629 perf_event_ctx_unlock(event
, ctx
);
2633 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2635 static void ctx_sched_out(struct perf_event_context
*ctx
,
2636 struct perf_cpu_context
*cpuctx
,
2637 enum event_type_t event_type
)
2639 int is_active
= ctx
->is_active
;
2640 struct perf_event
*event
;
2642 lockdep_assert_held(&ctx
->lock
);
2644 if (likely(!ctx
->nr_events
)) {
2646 * See __perf_remove_from_context().
2648 WARN_ON_ONCE(ctx
->is_active
);
2650 WARN_ON_ONCE(cpuctx
->task_ctx
);
2654 ctx
->is_active
&= ~event_type
;
2655 if (!(ctx
->is_active
& EVENT_ALL
))
2659 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2660 if (!ctx
->is_active
)
2661 cpuctx
->task_ctx
= NULL
;
2665 * Always update time if it was set; not only when it changes.
2666 * Otherwise we can 'forget' to update time for any but the last
2667 * context we sched out. For example:
2669 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2670 * ctx_sched_out(.event_type = EVENT_PINNED)
2672 * would only update time for the pinned events.
2674 if (is_active
& EVENT_TIME
) {
2675 /* update (and stop) ctx time */
2676 update_context_time(ctx
);
2677 update_cgrp_time_from_cpuctx(cpuctx
);
2680 is_active
^= ctx
->is_active
; /* changed bits */
2682 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2685 perf_pmu_disable(ctx
->pmu
);
2686 if (is_active
& EVENT_PINNED
) {
2687 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2688 group_sched_out(event
, cpuctx
, ctx
);
2691 if (is_active
& EVENT_FLEXIBLE
) {
2692 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2693 group_sched_out(event
, cpuctx
, ctx
);
2695 perf_pmu_enable(ctx
->pmu
);
2699 * Test whether two contexts are equivalent, i.e. whether they have both been
2700 * cloned from the same version of the same context.
2702 * Equivalence is measured using a generation number in the context that is
2703 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2704 * and list_del_event().
2706 static int context_equiv(struct perf_event_context
*ctx1
,
2707 struct perf_event_context
*ctx2
)
2709 lockdep_assert_held(&ctx1
->lock
);
2710 lockdep_assert_held(&ctx2
->lock
);
2712 /* Pinning disables the swap optimization */
2713 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2716 /* If ctx1 is the parent of ctx2 */
2717 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2720 /* If ctx2 is the parent of ctx1 */
2721 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2725 * If ctx1 and ctx2 have the same parent; we flatten the parent
2726 * hierarchy, see perf_event_init_context().
2728 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2729 ctx1
->parent_gen
== ctx2
->parent_gen
)
2736 static void __perf_event_sync_stat(struct perf_event
*event
,
2737 struct perf_event
*next_event
)
2741 if (!event
->attr
.inherit_stat
)
2745 * Update the event value, we cannot use perf_event_read()
2746 * because we're in the middle of a context switch and have IRQs
2747 * disabled, which upsets smp_call_function_single(), however
2748 * we know the event must be on the current CPU, therefore we
2749 * don't need to use it.
2751 switch (event
->state
) {
2752 case PERF_EVENT_STATE_ACTIVE
:
2753 event
->pmu
->read(event
);
2756 case PERF_EVENT_STATE_INACTIVE
:
2757 update_event_times(event
);
2765 * In order to keep per-task stats reliable we need to flip the event
2766 * values when we flip the contexts.
2768 value
= local64_read(&next_event
->count
);
2769 value
= local64_xchg(&event
->count
, value
);
2770 local64_set(&next_event
->count
, value
);
2772 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2773 swap(event
->total_time_running
, next_event
->total_time_running
);
2776 * Since we swizzled the values, update the user visible data too.
2778 perf_event_update_userpage(event
);
2779 perf_event_update_userpage(next_event
);
2782 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2783 struct perf_event_context
*next_ctx
)
2785 struct perf_event
*event
, *next_event
;
2790 update_context_time(ctx
);
2792 event
= list_first_entry(&ctx
->event_list
,
2793 struct perf_event
, event_entry
);
2795 next_event
= list_first_entry(&next_ctx
->event_list
,
2796 struct perf_event
, event_entry
);
2798 while (&event
->event_entry
!= &ctx
->event_list
&&
2799 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2801 __perf_event_sync_stat(event
, next_event
);
2803 event
= list_next_entry(event
, event_entry
);
2804 next_event
= list_next_entry(next_event
, event_entry
);
2808 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2809 struct task_struct
*next
)
2811 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2812 struct perf_event_context
*next_ctx
;
2813 struct perf_event_context
*parent
, *next_parent
;
2814 struct perf_cpu_context
*cpuctx
;
2820 cpuctx
= __get_cpu_context(ctx
);
2821 if (!cpuctx
->task_ctx
)
2825 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2829 parent
= rcu_dereference(ctx
->parent_ctx
);
2830 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2832 /* If neither context have a parent context; they cannot be clones. */
2833 if (!parent
&& !next_parent
)
2836 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2838 * Looks like the two contexts are clones, so we might be
2839 * able to optimize the context switch. We lock both
2840 * contexts and check that they are clones under the
2841 * lock (including re-checking that neither has been
2842 * uncloned in the meantime). It doesn't matter which
2843 * order we take the locks because no other cpu could
2844 * be trying to lock both of these tasks.
2846 raw_spin_lock(&ctx
->lock
);
2847 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2848 if (context_equiv(ctx
, next_ctx
)) {
2849 WRITE_ONCE(ctx
->task
, next
);
2850 WRITE_ONCE(next_ctx
->task
, task
);
2852 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2855 * RCU_INIT_POINTER here is safe because we've not
2856 * modified the ctx and the above modification of
2857 * ctx->task and ctx->task_ctx_data are immaterial
2858 * since those values are always verified under
2859 * ctx->lock which we're now holding.
2861 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2862 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2866 perf_event_sync_stat(ctx
, next_ctx
);
2868 raw_spin_unlock(&next_ctx
->lock
);
2869 raw_spin_unlock(&ctx
->lock
);
2875 raw_spin_lock(&ctx
->lock
);
2876 task_ctx_sched_out(cpuctx
, ctx
);
2877 raw_spin_unlock(&ctx
->lock
);
2881 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
2883 void perf_sched_cb_dec(struct pmu
*pmu
)
2885 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2887 this_cpu_dec(perf_sched_cb_usages
);
2889 if (!--cpuctx
->sched_cb_usage
)
2890 list_del(&cpuctx
->sched_cb_entry
);
2894 void perf_sched_cb_inc(struct pmu
*pmu
)
2896 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2898 if (!cpuctx
->sched_cb_usage
++)
2899 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
2901 this_cpu_inc(perf_sched_cb_usages
);
2905 * This function provides the context switch callback to the lower code
2906 * layer. It is invoked ONLY when the context switch callback is enabled.
2908 * This callback is relevant even to per-cpu events; for example multi event
2909 * PEBS requires this to provide PID/TID information. This requires we flush
2910 * all queued PEBS records before we context switch to a new task.
2912 static void perf_pmu_sched_task(struct task_struct
*prev
,
2913 struct task_struct
*next
,
2916 struct perf_cpu_context
*cpuctx
;
2922 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
2923 pmu
= cpuctx
->unique_pmu
; /* software PMUs will not have sched_task */
2925 if (WARN_ON_ONCE(!pmu
->sched_task
))
2928 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2929 perf_pmu_disable(pmu
);
2931 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2933 perf_pmu_enable(pmu
);
2934 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2938 static void perf_event_switch(struct task_struct
*task
,
2939 struct task_struct
*next_prev
, bool sched_in
);
2941 #define for_each_task_context_nr(ctxn) \
2942 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2945 * Called from scheduler to remove the events of the current task,
2946 * with interrupts disabled.
2948 * We stop each event and update the event value in event->count.
2950 * This does not protect us against NMI, but disable()
2951 * sets the disabled bit in the control field of event _before_
2952 * accessing the event control register. If a NMI hits, then it will
2953 * not restart the event.
2955 void __perf_event_task_sched_out(struct task_struct
*task
,
2956 struct task_struct
*next
)
2960 if (__this_cpu_read(perf_sched_cb_usages
))
2961 perf_pmu_sched_task(task
, next
, false);
2963 if (atomic_read(&nr_switch_events
))
2964 perf_event_switch(task
, next
, false);
2966 for_each_task_context_nr(ctxn
)
2967 perf_event_context_sched_out(task
, ctxn
, next
);
2970 * if cgroup events exist on this CPU, then we need
2971 * to check if we have to switch out PMU state.
2972 * cgroup event are system-wide mode only
2974 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2975 perf_cgroup_sched_out(task
, next
);
2979 * Called with IRQs disabled
2981 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2982 enum event_type_t event_type
)
2984 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2988 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2989 struct perf_cpu_context
*cpuctx
)
2991 struct perf_event
*event
;
2993 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2994 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2996 if (!event_filter_match(event
))
2999 /* may need to reset tstamp_enabled */
3000 if (is_cgroup_event(event
))
3001 perf_cgroup_mark_enabled(event
, ctx
);
3003 if (group_can_go_on(event
, cpuctx
, 1))
3004 group_sched_in(event
, cpuctx
, ctx
);
3007 * If this pinned group hasn't been scheduled,
3008 * put it in error state.
3010 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3011 update_group_times(event
);
3012 event
->state
= PERF_EVENT_STATE_ERROR
;
3018 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3019 struct perf_cpu_context
*cpuctx
)
3021 struct perf_event
*event
;
3024 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3025 /* Ignore events in OFF or ERROR state */
3026 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3029 * Listen to the 'cpu' scheduling filter constraint
3032 if (!event_filter_match(event
))
3035 /* may need to reset tstamp_enabled */
3036 if (is_cgroup_event(event
))
3037 perf_cgroup_mark_enabled(event
, ctx
);
3039 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3040 if (group_sched_in(event
, cpuctx
, ctx
))
3047 ctx_sched_in(struct perf_event_context
*ctx
,
3048 struct perf_cpu_context
*cpuctx
,
3049 enum event_type_t event_type
,
3050 struct task_struct
*task
)
3052 int is_active
= ctx
->is_active
;
3055 lockdep_assert_held(&ctx
->lock
);
3057 if (likely(!ctx
->nr_events
))
3060 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3063 cpuctx
->task_ctx
= ctx
;
3065 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3068 is_active
^= ctx
->is_active
; /* changed bits */
3070 if (is_active
& EVENT_TIME
) {
3071 /* start ctx time */
3073 ctx
->timestamp
= now
;
3074 perf_cgroup_set_timestamp(task
, ctx
);
3078 * First go through the list and put on any pinned groups
3079 * in order to give them the best chance of going on.
3081 if (is_active
& EVENT_PINNED
)
3082 ctx_pinned_sched_in(ctx
, cpuctx
);
3084 /* Then walk through the lower prio flexible groups */
3085 if (is_active
& EVENT_FLEXIBLE
)
3086 ctx_flexible_sched_in(ctx
, cpuctx
);
3089 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3090 enum event_type_t event_type
,
3091 struct task_struct
*task
)
3093 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3095 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3098 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3099 struct task_struct
*task
)
3101 struct perf_cpu_context
*cpuctx
;
3103 cpuctx
= __get_cpu_context(ctx
);
3104 if (cpuctx
->task_ctx
== ctx
)
3107 perf_ctx_lock(cpuctx
, ctx
);
3108 perf_pmu_disable(ctx
->pmu
);
3110 * We want to keep the following priority order:
3111 * cpu pinned (that don't need to move), task pinned,
3112 * cpu flexible, task flexible.
3114 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3115 perf_event_sched_in(cpuctx
, ctx
, task
);
3116 perf_pmu_enable(ctx
->pmu
);
3117 perf_ctx_unlock(cpuctx
, ctx
);
3121 * Called from scheduler to add the events of the current task
3122 * with interrupts disabled.
3124 * We restore the event value and then enable it.
3126 * This does not protect us against NMI, but enable()
3127 * sets the enabled bit in the control field of event _before_
3128 * accessing the event control register. If a NMI hits, then it will
3129 * keep the event running.
3131 void __perf_event_task_sched_in(struct task_struct
*prev
,
3132 struct task_struct
*task
)
3134 struct perf_event_context
*ctx
;
3138 * If cgroup events exist on this CPU, then we need to check if we have
3139 * to switch in PMU state; cgroup event are system-wide mode only.
3141 * Since cgroup events are CPU events, we must schedule these in before
3142 * we schedule in the task events.
3144 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3145 perf_cgroup_sched_in(prev
, task
);
3147 for_each_task_context_nr(ctxn
) {
3148 ctx
= task
->perf_event_ctxp
[ctxn
];
3152 perf_event_context_sched_in(ctx
, task
);
3155 if (atomic_read(&nr_switch_events
))
3156 perf_event_switch(task
, prev
, true);
3158 if (__this_cpu_read(perf_sched_cb_usages
))
3159 perf_pmu_sched_task(prev
, task
, true);
3162 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3164 u64 frequency
= event
->attr
.sample_freq
;
3165 u64 sec
= NSEC_PER_SEC
;
3166 u64 divisor
, dividend
;
3168 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3170 count_fls
= fls64(count
);
3171 nsec_fls
= fls64(nsec
);
3172 frequency_fls
= fls64(frequency
);
3176 * We got @count in @nsec, with a target of sample_freq HZ
3177 * the target period becomes:
3180 * period = -------------------
3181 * @nsec * sample_freq
3186 * Reduce accuracy by one bit such that @a and @b converge
3187 * to a similar magnitude.
3189 #define REDUCE_FLS(a, b) \
3191 if (a##_fls > b##_fls) { \
3201 * Reduce accuracy until either term fits in a u64, then proceed with
3202 * the other, so that finally we can do a u64/u64 division.
3204 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3205 REDUCE_FLS(nsec
, frequency
);
3206 REDUCE_FLS(sec
, count
);
3209 if (count_fls
+ sec_fls
> 64) {
3210 divisor
= nsec
* frequency
;
3212 while (count_fls
+ sec_fls
> 64) {
3213 REDUCE_FLS(count
, sec
);
3217 dividend
= count
* sec
;
3219 dividend
= count
* sec
;
3221 while (nsec_fls
+ frequency_fls
> 64) {
3222 REDUCE_FLS(nsec
, frequency
);
3226 divisor
= nsec
* frequency
;
3232 return div64_u64(dividend
, divisor
);
3235 static DEFINE_PER_CPU(int, perf_throttled_count
);
3236 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3238 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3240 struct hw_perf_event
*hwc
= &event
->hw
;
3241 s64 period
, sample_period
;
3244 period
= perf_calculate_period(event
, nsec
, count
);
3246 delta
= (s64
)(period
- hwc
->sample_period
);
3247 delta
= (delta
+ 7) / 8; /* low pass filter */
3249 sample_period
= hwc
->sample_period
+ delta
;
3254 hwc
->sample_period
= sample_period
;
3256 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3258 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3260 local64_set(&hwc
->period_left
, 0);
3263 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3268 * combine freq adjustment with unthrottling to avoid two passes over the
3269 * events. At the same time, make sure, having freq events does not change
3270 * the rate of unthrottling as that would introduce bias.
3272 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3275 struct perf_event
*event
;
3276 struct hw_perf_event
*hwc
;
3277 u64 now
, period
= TICK_NSEC
;
3281 * only need to iterate over all events iff:
3282 * - context have events in frequency mode (needs freq adjust)
3283 * - there are events to unthrottle on this cpu
3285 if (!(ctx
->nr_freq
|| needs_unthr
))
3288 raw_spin_lock(&ctx
->lock
);
3289 perf_pmu_disable(ctx
->pmu
);
3291 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3292 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3295 if (!event_filter_match(event
))
3298 perf_pmu_disable(event
->pmu
);
3302 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3303 hwc
->interrupts
= 0;
3304 perf_log_throttle(event
, 1);
3305 event
->pmu
->start(event
, 0);
3308 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3312 * stop the event and update event->count
3314 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3316 now
= local64_read(&event
->count
);
3317 delta
= now
- hwc
->freq_count_stamp
;
3318 hwc
->freq_count_stamp
= now
;
3322 * reload only if value has changed
3323 * we have stopped the event so tell that
3324 * to perf_adjust_period() to avoid stopping it
3328 perf_adjust_period(event
, period
, delta
, false);
3330 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3332 perf_pmu_enable(event
->pmu
);
3335 perf_pmu_enable(ctx
->pmu
);
3336 raw_spin_unlock(&ctx
->lock
);
3340 * Round-robin a context's events:
3342 static void rotate_ctx(struct perf_event_context
*ctx
)
3345 * Rotate the first entry last of non-pinned groups. Rotation might be
3346 * disabled by the inheritance code.
3348 if (!ctx
->rotate_disable
)
3349 list_rotate_left(&ctx
->flexible_groups
);
3352 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3354 struct perf_event_context
*ctx
= NULL
;
3357 if (cpuctx
->ctx
.nr_events
) {
3358 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3362 ctx
= cpuctx
->task_ctx
;
3363 if (ctx
&& ctx
->nr_events
) {
3364 if (ctx
->nr_events
!= ctx
->nr_active
)
3371 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3372 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3374 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3376 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3378 rotate_ctx(&cpuctx
->ctx
);
3382 perf_event_sched_in(cpuctx
, ctx
, current
);
3384 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3385 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3391 void perf_event_task_tick(void)
3393 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3394 struct perf_event_context
*ctx
, *tmp
;
3397 WARN_ON(!irqs_disabled());
3399 __this_cpu_inc(perf_throttled_seq
);
3400 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3401 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3403 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3404 perf_adjust_freq_unthr_context(ctx
, throttled
);
3407 static int event_enable_on_exec(struct perf_event
*event
,
3408 struct perf_event_context
*ctx
)
3410 if (!event
->attr
.enable_on_exec
)
3413 event
->attr
.enable_on_exec
= 0;
3414 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3417 __perf_event_mark_enabled(event
);
3423 * Enable all of a task's events that have been marked enable-on-exec.
3424 * This expects task == current.
3426 static void perf_event_enable_on_exec(int ctxn
)
3428 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3429 struct perf_cpu_context
*cpuctx
;
3430 struct perf_event
*event
;
3431 unsigned long flags
;
3434 local_irq_save(flags
);
3435 ctx
= current
->perf_event_ctxp
[ctxn
];
3436 if (!ctx
|| !ctx
->nr_events
)
3439 cpuctx
= __get_cpu_context(ctx
);
3440 perf_ctx_lock(cpuctx
, ctx
);
3441 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3442 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
3443 enabled
|= event_enable_on_exec(event
, ctx
);
3446 * Unclone and reschedule this context if we enabled any event.
3449 clone_ctx
= unclone_ctx(ctx
);
3450 ctx_resched(cpuctx
, ctx
);
3452 perf_ctx_unlock(cpuctx
, ctx
);
3455 local_irq_restore(flags
);
3461 struct perf_read_data
{
3462 struct perf_event
*event
;
3467 static int find_cpu_to_read(struct perf_event
*event
, int local_cpu
)
3469 int event_cpu
= event
->oncpu
;
3470 u16 local_pkg
, event_pkg
;
3472 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3473 event_pkg
= topology_physical_package_id(event_cpu
);
3474 local_pkg
= topology_physical_package_id(local_cpu
);
3476 if (event_pkg
== local_pkg
)
3484 * Cross CPU call to read the hardware event
3486 static void __perf_event_read(void *info
)
3488 struct perf_read_data
*data
= info
;
3489 struct perf_event
*sub
, *event
= data
->event
;
3490 struct perf_event_context
*ctx
= event
->ctx
;
3491 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3492 struct pmu
*pmu
= event
->pmu
;
3495 * If this is a task context, we need to check whether it is
3496 * the current task context of this cpu. If not it has been
3497 * scheduled out before the smp call arrived. In that case
3498 * event->count would have been updated to a recent sample
3499 * when the event was scheduled out.
3501 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3504 raw_spin_lock(&ctx
->lock
);
3505 if (ctx
->is_active
) {
3506 update_context_time(ctx
);
3507 update_cgrp_time_from_event(event
);
3510 update_event_times(event
);
3511 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3520 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3524 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3525 update_event_times(sub
);
3526 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3528 * Use sibling's PMU rather than @event's since
3529 * sibling could be on different (eg: software) PMU.
3531 sub
->pmu
->read(sub
);
3535 data
->ret
= pmu
->commit_txn(pmu
);
3538 raw_spin_unlock(&ctx
->lock
);
3541 static inline u64
perf_event_count(struct perf_event
*event
)
3543 if (event
->pmu
->count
)
3544 return event
->pmu
->count(event
);
3546 return __perf_event_count(event
);
3550 * NMI-safe method to read a local event, that is an event that
3552 * - either for the current task, or for this CPU
3553 * - does not have inherit set, for inherited task events
3554 * will not be local and we cannot read them atomically
3555 * - must not have a pmu::count method
3557 u64
perf_event_read_local(struct perf_event
*event
)
3559 unsigned long flags
;
3563 * Disabling interrupts avoids all counter scheduling (context
3564 * switches, timer based rotation and IPIs).
3566 local_irq_save(flags
);
3568 /* If this is a per-task event, it must be for current */
3569 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3570 event
->hw
.target
!= current
);
3572 /* If this is a per-CPU event, it must be for this CPU */
3573 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3574 event
->cpu
!= smp_processor_id());
3577 * It must not be an event with inherit set, we cannot read
3578 * all child counters from atomic context.
3580 WARN_ON_ONCE(event
->attr
.inherit
);
3583 * It must not have a pmu::count method, those are not
3586 WARN_ON_ONCE(event
->pmu
->count
);
3589 * If the event is currently on this CPU, its either a per-task event,
3590 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3593 if (event
->oncpu
== smp_processor_id())
3594 event
->pmu
->read(event
);
3596 val
= local64_read(&event
->count
);
3597 local_irq_restore(flags
);
3602 static int perf_event_read(struct perf_event
*event
, bool group
)
3604 int ret
= 0, cpu_to_read
, local_cpu
;
3607 * If event is enabled and currently active on a CPU, update the
3608 * value in the event structure:
3610 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3611 struct perf_read_data data
= {
3617 local_cpu
= get_cpu();
3618 cpu_to_read
= find_cpu_to_read(event
, local_cpu
);
3622 * Purposely ignore the smp_call_function_single() return
3625 * If event->oncpu isn't a valid CPU it means the event got
3626 * scheduled out and that will have updated the event count.
3628 * Therefore, either way, we'll have an up-to-date event count
3631 (void)smp_call_function_single(cpu_to_read
, __perf_event_read
, &data
, 1);
3633 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3634 struct perf_event_context
*ctx
= event
->ctx
;
3635 unsigned long flags
;
3637 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3639 * may read while context is not active
3640 * (e.g., thread is blocked), in that case
3641 * we cannot update context time
3643 if (ctx
->is_active
) {
3644 update_context_time(ctx
);
3645 update_cgrp_time_from_event(event
);
3648 update_group_times(event
);
3650 update_event_times(event
);
3651 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3658 * Initialize the perf_event context in a task_struct:
3660 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3662 raw_spin_lock_init(&ctx
->lock
);
3663 mutex_init(&ctx
->mutex
);
3664 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3665 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3666 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3667 INIT_LIST_HEAD(&ctx
->event_list
);
3668 atomic_set(&ctx
->refcount
, 1);
3671 static struct perf_event_context
*
3672 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3674 struct perf_event_context
*ctx
;
3676 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3680 __perf_event_init_context(ctx
);
3683 get_task_struct(task
);
3690 static struct task_struct
*
3691 find_lively_task_by_vpid(pid_t vpid
)
3693 struct task_struct
*task
;
3699 task
= find_task_by_vpid(vpid
);
3701 get_task_struct(task
);
3705 return ERR_PTR(-ESRCH
);
3711 * Returns a matching context with refcount and pincount.
3713 static struct perf_event_context
*
3714 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3715 struct perf_event
*event
)
3717 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3718 struct perf_cpu_context
*cpuctx
;
3719 void *task_ctx_data
= NULL
;
3720 unsigned long flags
;
3722 int cpu
= event
->cpu
;
3725 /* Must be root to operate on a CPU event: */
3726 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3727 return ERR_PTR(-EACCES
);
3730 * We could be clever and allow to attach a event to an
3731 * offline CPU and activate it when the CPU comes up, but
3734 if (!cpu_online(cpu
))
3735 return ERR_PTR(-ENODEV
);
3737 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3746 ctxn
= pmu
->task_ctx_nr
;
3750 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3751 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3752 if (!task_ctx_data
) {
3759 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3761 clone_ctx
= unclone_ctx(ctx
);
3764 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3765 ctx
->task_ctx_data
= task_ctx_data
;
3766 task_ctx_data
= NULL
;
3768 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3773 ctx
= alloc_perf_context(pmu
, task
);
3778 if (task_ctx_data
) {
3779 ctx
->task_ctx_data
= task_ctx_data
;
3780 task_ctx_data
= NULL
;
3784 mutex_lock(&task
->perf_event_mutex
);
3786 * If it has already passed perf_event_exit_task().
3787 * we must see PF_EXITING, it takes this mutex too.
3789 if (task
->flags
& PF_EXITING
)
3791 else if (task
->perf_event_ctxp
[ctxn
])
3796 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3798 mutex_unlock(&task
->perf_event_mutex
);
3800 if (unlikely(err
)) {
3809 kfree(task_ctx_data
);
3813 kfree(task_ctx_data
);
3814 return ERR_PTR(err
);
3817 static void perf_event_free_filter(struct perf_event
*event
);
3818 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3820 static void free_event_rcu(struct rcu_head
*head
)
3822 struct perf_event
*event
;
3824 event
= container_of(head
, struct perf_event
, rcu_head
);
3826 put_pid_ns(event
->ns
);
3827 perf_event_free_filter(event
);
3831 static void ring_buffer_attach(struct perf_event
*event
,
3832 struct ring_buffer
*rb
);
3834 static void detach_sb_event(struct perf_event
*event
)
3836 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3838 raw_spin_lock(&pel
->lock
);
3839 list_del_rcu(&event
->sb_list
);
3840 raw_spin_unlock(&pel
->lock
);
3843 static bool is_sb_event(struct perf_event
*event
)
3845 struct perf_event_attr
*attr
= &event
->attr
;
3850 if (event
->attach_state
& PERF_ATTACH_TASK
)
3853 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3854 attr
->comm
|| attr
->comm_exec
||
3856 attr
->context_switch
)
3861 static void unaccount_pmu_sb_event(struct perf_event
*event
)
3863 if (is_sb_event(event
))
3864 detach_sb_event(event
);
3867 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3872 if (is_cgroup_event(event
))
3873 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3876 #ifdef CONFIG_NO_HZ_FULL
3877 static DEFINE_SPINLOCK(nr_freq_lock
);
3880 static void unaccount_freq_event_nohz(void)
3882 #ifdef CONFIG_NO_HZ_FULL
3883 spin_lock(&nr_freq_lock
);
3884 if (atomic_dec_and_test(&nr_freq_events
))
3885 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3886 spin_unlock(&nr_freq_lock
);
3890 static void unaccount_freq_event(void)
3892 if (tick_nohz_full_enabled())
3893 unaccount_freq_event_nohz();
3895 atomic_dec(&nr_freq_events
);
3898 static void unaccount_event(struct perf_event
*event
)
3905 if (event
->attach_state
& PERF_ATTACH_TASK
)
3907 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3908 atomic_dec(&nr_mmap_events
);
3909 if (event
->attr
.comm
)
3910 atomic_dec(&nr_comm_events
);
3911 if (event
->attr
.task
)
3912 atomic_dec(&nr_task_events
);
3913 if (event
->attr
.freq
)
3914 unaccount_freq_event();
3915 if (event
->attr
.context_switch
) {
3917 atomic_dec(&nr_switch_events
);
3919 if (is_cgroup_event(event
))
3921 if (has_branch_stack(event
))
3925 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
3926 schedule_delayed_work(&perf_sched_work
, HZ
);
3929 unaccount_event_cpu(event
, event
->cpu
);
3931 unaccount_pmu_sb_event(event
);
3934 static void perf_sched_delayed(struct work_struct
*work
)
3936 mutex_lock(&perf_sched_mutex
);
3937 if (atomic_dec_and_test(&perf_sched_count
))
3938 static_branch_disable(&perf_sched_events
);
3939 mutex_unlock(&perf_sched_mutex
);
3943 * The following implement mutual exclusion of events on "exclusive" pmus
3944 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3945 * at a time, so we disallow creating events that might conflict, namely:
3947 * 1) cpu-wide events in the presence of per-task events,
3948 * 2) per-task events in the presence of cpu-wide events,
3949 * 3) two matching events on the same context.
3951 * The former two cases are handled in the allocation path (perf_event_alloc(),
3952 * _free_event()), the latter -- before the first perf_install_in_context().
3954 static int exclusive_event_init(struct perf_event
*event
)
3956 struct pmu
*pmu
= event
->pmu
;
3958 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3962 * Prevent co-existence of per-task and cpu-wide events on the
3963 * same exclusive pmu.
3965 * Negative pmu::exclusive_cnt means there are cpu-wide
3966 * events on this "exclusive" pmu, positive means there are
3969 * Since this is called in perf_event_alloc() path, event::ctx
3970 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3971 * to mean "per-task event", because unlike other attach states it
3972 * never gets cleared.
3974 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3975 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3978 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3985 static void exclusive_event_destroy(struct perf_event
*event
)
3987 struct pmu
*pmu
= event
->pmu
;
3989 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3992 /* see comment in exclusive_event_init() */
3993 if (event
->attach_state
& PERF_ATTACH_TASK
)
3994 atomic_dec(&pmu
->exclusive_cnt
);
3996 atomic_inc(&pmu
->exclusive_cnt
);
3999 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4001 if ((e1
->pmu
== e2
->pmu
) &&
4002 (e1
->cpu
== e2
->cpu
||
4009 /* Called under the same ctx::mutex as perf_install_in_context() */
4010 static bool exclusive_event_installable(struct perf_event
*event
,
4011 struct perf_event_context
*ctx
)
4013 struct perf_event
*iter_event
;
4014 struct pmu
*pmu
= event
->pmu
;
4016 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4019 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4020 if (exclusive_event_match(iter_event
, event
))
4027 static void perf_addr_filters_splice(struct perf_event
*event
,
4028 struct list_head
*head
);
4030 static void _free_event(struct perf_event
*event
)
4032 irq_work_sync(&event
->pending
);
4034 unaccount_event(event
);
4038 * Can happen when we close an event with re-directed output.
4040 * Since we have a 0 refcount, perf_mmap_close() will skip
4041 * over us; possibly making our ring_buffer_put() the last.
4043 mutex_lock(&event
->mmap_mutex
);
4044 ring_buffer_attach(event
, NULL
);
4045 mutex_unlock(&event
->mmap_mutex
);
4048 if (is_cgroup_event(event
))
4049 perf_detach_cgroup(event
);
4051 if (!event
->parent
) {
4052 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4053 put_callchain_buffers();
4056 perf_event_free_bpf_prog(event
);
4057 perf_addr_filters_splice(event
, NULL
);
4058 kfree(event
->addr_filters_offs
);
4061 event
->destroy(event
);
4064 put_ctx(event
->ctx
);
4066 exclusive_event_destroy(event
);
4067 module_put(event
->pmu
->module
);
4069 call_rcu(&event
->rcu_head
, free_event_rcu
);
4073 * Used to free events which have a known refcount of 1, such as in error paths
4074 * where the event isn't exposed yet and inherited events.
4076 static void free_event(struct perf_event
*event
)
4078 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4079 "unexpected event refcount: %ld; ptr=%p\n",
4080 atomic_long_read(&event
->refcount
), event
)) {
4081 /* leak to avoid use-after-free */
4089 * Remove user event from the owner task.
4091 static void perf_remove_from_owner(struct perf_event
*event
)
4093 struct task_struct
*owner
;
4097 * Matches the smp_store_release() in perf_event_exit_task(). If we
4098 * observe !owner it means the list deletion is complete and we can
4099 * indeed free this event, otherwise we need to serialize on
4100 * owner->perf_event_mutex.
4102 owner
= lockless_dereference(event
->owner
);
4105 * Since delayed_put_task_struct() also drops the last
4106 * task reference we can safely take a new reference
4107 * while holding the rcu_read_lock().
4109 get_task_struct(owner
);
4115 * If we're here through perf_event_exit_task() we're already
4116 * holding ctx->mutex which would be an inversion wrt. the
4117 * normal lock order.
4119 * However we can safely take this lock because its the child
4122 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4125 * We have to re-check the event->owner field, if it is cleared
4126 * we raced with perf_event_exit_task(), acquiring the mutex
4127 * ensured they're done, and we can proceed with freeing the
4131 list_del_init(&event
->owner_entry
);
4132 smp_store_release(&event
->owner
, NULL
);
4134 mutex_unlock(&owner
->perf_event_mutex
);
4135 put_task_struct(owner
);
4139 static void put_event(struct perf_event
*event
)
4141 if (!atomic_long_dec_and_test(&event
->refcount
))
4148 * Kill an event dead; while event:refcount will preserve the event
4149 * object, it will not preserve its functionality. Once the last 'user'
4150 * gives up the object, we'll destroy the thing.
4152 int perf_event_release_kernel(struct perf_event
*event
)
4154 struct perf_event_context
*ctx
= event
->ctx
;
4155 struct perf_event
*child
, *tmp
;
4158 * If we got here through err_file: fput(event_file); we will not have
4159 * attached to a context yet.
4162 WARN_ON_ONCE(event
->attach_state
&
4163 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4167 if (!is_kernel_event(event
))
4168 perf_remove_from_owner(event
);
4170 ctx
= perf_event_ctx_lock(event
);
4171 WARN_ON_ONCE(ctx
->parent_ctx
);
4172 perf_remove_from_context(event
, DETACH_GROUP
);
4174 raw_spin_lock_irq(&ctx
->lock
);
4176 * Mark this even as STATE_DEAD, there is no external reference to it
4179 * Anybody acquiring event->child_mutex after the below loop _must_
4180 * also see this, most importantly inherit_event() which will avoid
4181 * placing more children on the list.
4183 * Thus this guarantees that we will in fact observe and kill _ALL_
4186 event
->state
= PERF_EVENT_STATE_DEAD
;
4187 raw_spin_unlock_irq(&ctx
->lock
);
4189 perf_event_ctx_unlock(event
, ctx
);
4192 mutex_lock(&event
->child_mutex
);
4193 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4196 * Cannot change, child events are not migrated, see the
4197 * comment with perf_event_ctx_lock_nested().
4199 ctx
= lockless_dereference(child
->ctx
);
4201 * Since child_mutex nests inside ctx::mutex, we must jump
4202 * through hoops. We start by grabbing a reference on the ctx.
4204 * Since the event cannot get freed while we hold the
4205 * child_mutex, the context must also exist and have a !0
4211 * Now that we have a ctx ref, we can drop child_mutex, and
4212 * acquire ctx::mutex without fear of it going away. Then we
4213 * can re-acquire child_mutex.
4215 mutex_unlock(&event
->child_mutex
);
4216 mutex_lock(&ctx
->mutex
);
4217 mutex_lock(&event
->child_mutex
);
4220 * Now that we hold ctx::mutex and child_mutex, revalidate our
4221 * state, if child is still the first entry, it didn't get freed
4222 * and we can continue doing so.
4224 tmp
= list_first_entry_or_null(&event
->child_list
,
4225 struct perf_event
, child_list
);
4227 perf_remove_from_context(child
, DETACH_GROUP
);
4228 list_del(&child
->child_list
);
4231 * This matches the refcount bump in inherit_event();
4232 * this can't be the last reference.
4237 mutex_unlock(&event
->child_mutex
);
4238 mutex_unlock(&ctx
->mutex
);
4242 mutex_unlock(&event
->child_mutex
);
4245 put_event(event
); /* Must be the 'last' reference */
4248 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4251 * Called when the last reference to the file is gone.
4253 static int perf_release(struct inode
*inode
, struct file
*file
)
4255 perf_event_release_kernel(file
->private_data
);
4259 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4261 struct perf_event
*child
;
4267 mutex_lock(&event
->child_mutex
);
4269 (void)perf_event_read(event
, false);
4270 total
+= perf_event_count(event
);
4272 *enabled
+= event
->total_time_enabled
+
4273 atomic64_read(&event
->child_total_time_enabled
);
4274 *running
+= event
->total_time_running
+
4275 atomic64_read(&event
->child_total_time_running
);
4277 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4278 (void)perf_event_read(child
, false);
4279 total
+= perf_event_count(child
);
4280 *enabled
+= child
->total_time_enabled
;
4281 *running
+= child
->total_time_running
;
4283 mutex_unlock(&event
->child_mutex
);
4287 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4289 static int __perf_read_group_add(struct perf_event
*leader
,
4290 u64 read_format
, u64
*values
)
4292 struct perf_event
*sub
;
4293 int n
= 1; /* skip @nr */
4296 ret
= perf_event_read(leader
, true);
4301 * Since we co-schedule groups, {enabled,running} times of siblings
4302 * will be identical to those of the leader, so we only publish one
4305 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4306 values
[n
++] += leader
->total_time_enabled
+
4307 atomic64_read(&leader
->child_total_time_enabled
);
4310 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4311 values
[n
++] += leader
->total_time_running
+
4312 atomic64_read(&leader
->child_total_time_running
);
4316 * Write {count,id} tuples for every sibling.
4318 values
[n
++] += perf_event_count(leader
);
4319 if (read_format
& PERF_FORMAT_ID
)
4320 values
[n
++] = primary_event_id(leader
);
4322 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4323 values
[n
++] += perf_event_count(sub
);
4324 if (read_format
& PERF_FORMAT_ID
)
4325 values
[n
++] = primary_event_id(sub
);
4331 static int perf_read_group(struct perf_event
*event
,
4332 u64 read_format
, char __user
*buf
)
4334 struct perf_event
*leader
= event
->group_leader
, *child
;
4335 struct perf_event_context
*ctx
= leader
->ctx
;
4339 lockdep_assert_held(&ctx
->mutex
);
4341 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4345 values
[0] = 1 + leader
->nr_siblings
;
4348 * By locking the child_mutex of the leader we effectively
4349 * lock the child list of all siblings.. XXX explain how.
4351 mutex_lock(&leader
->child_mutex
);
4353 ret
= __perf_read_group_add(leader
, read_format
, values
);
4357 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4358 ret
= __perf_read_group_add(child
, read_format
, values
);
4363 mutex_unlock(&leader
->child_mutex
);
4365 ret
= event
->read_size
;
4366 if (copy_to_user(buf
, values
, event
->read_size
))
4371 mutex_unlock(&leader
->child_mutex
);
4377 static int perf_read_one(struct perf_event
*event
,
4378 u64 read_format
, char __user
*buf
)
4380 u64 enabled
, running
;
4384 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4385 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4386 values
[n
++] = enabled
;
4387 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4388 values
[n
++] = running
;
4389 if (read_format
& PERF_FORMAT_ID
)
4390 values
[n
++] = primary_event_id(event
);
4392 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4395 return n
* sizeof(u64
);
4398 static bool is_event_hup(struct perf_event
*event
)
4402 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4405 mutex_lock(&event
->child_mutex
);
4406 no_children
= list_empty(&event
->child_list
);
4407 mutex_unlock(&event
->child_mutex
);
4412 * Read the performance event - simple non blocking version for now
4415 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4417 u64 read_format
= event
->attr
.read_format
;
4421 * Return end-of-file for a read on a event that is in
4422 * error state (i.e. because it was pinned but it couldn't be
4423 * scheduled on to the CPU at some point).
4425 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4428 if (count
< event
->read_size
)
4431 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4432 if (read_format
& PERF_FORMAT_GROUP
)
4433 ret
= perf_read_group(event
, read_format
, buf
);
4435 ret
= perf_read_one(event
, read_format
, buf
);
4441 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4443 struct perf_event
*event
= file
->private_data
;
4444 struct perf_event_context
*ctx
;
4447 ctx
= perf_event_ctx_lock(event
);
4448 ret
= __perf_read(event
, buf
, count
);
4449 perf_event_ctx_unlock(event
, ctx
);
4454 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4456 struct perf_event
*event
= file
->private_data
;
4457 struct ring_buffer
*rb
;
4458 unsigned int events
= POLLHUP
;
4460 poll_wait(file
, &event
->waitq
, wait
);
4462 if (is_event_hup(event
))
4466 * Pin the event->rb by taking event->mmap_mutex; otherwise
4467 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4469 mutex_lock(&event
->mmap_mutex
);
4472 events
= atomic_xchg(&rb
->poll
, 0);
4473 mutex_unlock(&event
->mmap_mutex
);
4477 static void _perf_event_reset(struct perf_event
*event
)
4479 (void)perf_event_read(event
, false);
4480 local64_set(&event
->count
, 0);
4481 perf_event_update_userpage(event
);
4485 * Holding the top-level event's child_mutex means that any
4486 * descendant process that has inherited this event will block
4487 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4488 * task existence requirements of perf_event_enable/disable.
4490 static void perf_event_for_each_child(struct perf_event
*event
,
4491 void (*func
)(struct perf_event
*))
4493 struct perf_event
*child
;
4495 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4497 mutex_lock(&event
->child_mutex
);
4499 list_for_each_entry(child
, &event
->child_list
, child_list
)
4501 mutex_unlock(&event
->child_mutex
);
4504 static void perf_event_for_each(struct perf_event
*event
,
4505 void (*func
)(struct perf_event
*))
4507 struct perf_event_context
*ctx
= event
->ctx
;
4508 struct perf_event
*sibling
;
4510 lockdep_assert_held(&ctx
->mutex
);
4512 event
= event
->group_leader
;
4514 perf_event_for_each_child(event
, func
);
4515 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4516 perf_event_for_each_child(sibling
, func
);
4519 static void __perf_event_period(struct perf_event
*event
,
4520 struct perf_cpu_context
*cpuctx
,
4521 struct perf_event_context
*ctx
,
4524 u64 value
= *((u64
*)info
);
4527 if (event
->attr
.freq
) {
4528 event
->attr
.sample_freq
= value
;
4530 event
->attr
.sample_period
= value
;
4531 event
->hw
.sample_period
= value
;
4534 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4536 perf_pmu_disable(ctx
->pmu
);
4538 * We could be throttled; unthrottle now to avoid the tick
4539 * trying to unthrottle while we already re-started the event.
4541 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4542 event
->hw
.interrupts
= 0;
4543 perf_log_throttle(event
, 1);
4545 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4548 local64_set(&event
->hw
.period_left
, 0);
4551 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4552 perf_pmu_enable(ctx
->pmu
);
4556 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4560 if (!is_sampling_event(event
))
4563 if (copy_from_user(&value
, arg
, sizeof(value
)))
4569 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4572 event_function_call(event
, __perf_event_period
, &value
);
4577 static const struct file_operations perf_fops
;
4579 static inline int perf_fget_light(int fd
, struct fd
*p
)
4581 struct fd f
= fdget(fd
);
4585 if (f
.file
->f_op
!= &perf_fops
) {
4593 static int perf_event_set_output(struct perf_event
*event
,
4594 struct perf_event
*output_event
);
4595 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4596 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4598 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4600 void (*func
)(struct perf_event
*);
4604 case PERF_EVENT_IOC_ENABLE
:
4605 func
= _perf_event_enable
;
4607 case PERF_EVENT_IOC_DISABLE
:
4608 func
= _perf_event_disable
;
4610 case PERF_EVENT_IOC_RESET
:
4611 func
= _perf_event_reset
;
4614 case PERF_EVENT_IOC_REFRESH
:
4615 return _perf_event_refresh(event
, arg
);
4617 case PERF_EVENT_IOC_PERIOD
:
4618 return perf_event_period(event
, (u64 __user
*)arg
);
4620 case PERF_EVENT_IOC_ID
:
4622 u64 id
= primary_event_id(event
);
4624 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4629 case PERF_EVENT_IOC_SET_OUTPUT
:
4633 struct perf_event
*output_event
;
4635 ret
= perf_fget_light(arg
, &output
);
4638 output_event
= output
.file
->private_data
;
4639 ret
= perf_event_set_output(event
, output_event
);
4642 ret
= perf_event_set_output(event
, NULL
);
4647 case PERF_EVENT_IOC_SET_FILTER
:
4648 return perf_event_set_filter(event
, (void __user
*)arg
);
4650 case PERF_EVENT_IOC_SET_BPF
:
4651 return perf_event_set_bpf_prog(event
, arg
);
4653 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4654 struct ring_buffer
*rb
;
4657 rb
= rcu_dereference(event
->rb
);
4658 if (!rb
|| !rb
->nr_pages
) {
4662 rb_toggle_paused(rb
, !!arg
);
4670 if (flags
& PERF_IOC_FLAG_GROUP
)
4671 perf_event_for_each(event
, func
);
4673 perf_event_for_each_child(event
, func
);
4678 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4680 struct perf_event
*event
= file
->private_data
;
4681 struct perf_event_context
*ctx
;
4684 ctx
= perf_event_ctx_lock(event
);
4685 ret
= _perf_ioctl(event
, cmd
, arg
);
4686 perf_event_ctx_unlock(event
, ctx
);
4691 #ifdef CONFIG_COMPAT
4692 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4695 switch (_IOC_NR(cmd
)) {
4696 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4697 case _IOC_NR(PERF_EVENT_IOC_ID
):
4698 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4699 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4700 cmd
&= ~IOCSIZE_MASK
;
4701 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4705 return perf_ioctl(file
, cmd
, arg
);
4708 # define perf_compat_ioctl NULL
4711 int perf_event_task_enable(void)
4713 struct perf_event_context
*ctx
;
4714 struct perf_event
*event
;
4716 mutex_lock(¤t
->perf_event_mutex
);
4717 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4718 ctx
= perf_event_ctx_lock(event
);
4719 perf_event_for_each_child(event
, _perf_event_enable
);
4720 perf_event_ctx_unlock(event
, ctx
);
4722 mutex_unlock(¤t
->perf_event_mutex
);
4727 int perf_event_task_disable(void)
4729 struct perf_event_context
*ctx
;
4730 struct perf_event
*event
;
4732 mutex_lock(¤t
->perf_event_mutex
);
4733 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4734 ctx
= perf_event_ctx_lock(event
);
4735 perf_event_for_each_child(event
, _perf_event_disable
);
4736 perf_event_ctx_unlock(event
, ctx
);
4738 mutex_unlock(¤t
->perf_event_mutex
);
4743 static int perf_event_index(struct perf_event
*event
)
4745 if (event
->hw
.state
& PERF_HES_STOPPED
)
4748 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4751 return event
->pmu
->event_idx(event
);
4754 static void calc_timer_values(struct perf_event
*event
,
4761 *now
= perf_clock();
4762 ctx_time
= event
->shadow_ctx_time
+ *now
;
4763 *enabled
= ctx_time
- event
->tstamp_enabled
;
4764 *running
= ctx_time
- event
->tstamp_running
;
4767 static void perf_event_init_userpage(struct perf_event
*event
)
4769 struct perf_event_mmap_page
*userpg
;
4770 struct ring_buffer
*rb
;
4773 rb
= rcu_dereference(event
->rb
);
4777 userpg
= rb
->user_page
;
4779 /* Allow new userspace to detect that bit 0 is deprecated */
4780 userpg
->cap_bit0_is_deprecated
= 1;
4781 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4782 userpg
->data_offset
= PAGE_SIZE
;
4783 userpg
->data_size
= perf_data_size(rb
);
4789 void __weak
arch_perf_update_userpage(
4790 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4795 * Callers need to ensure there can be no nesting of this function, otherwise
4796 * the seqlock logic goes bad. We can not serialize this because the arch
4797 * code calls this from NMI context.
4799 void perf_event_update_userpage(struct perf_event
*event
)
4801 struct perf_event_mmap_page
*userpg
;
4802 struct ring_buffer
*rb
;
4803 u64 enabled
, running
, now
;
4806 rb
= rcu_dereference(event
->rb
);
4811 * compute total_time_enabled, total_time_running
4812 * based on snapshot values taken when the event
4813 * was last scheduled in.
4815 * we cannot simply called update_context_time()
4816 * because of locking issue as we can be called in
4819 calc_timer_values(event
, &now
, &enabled
, &running
);
4821 userpg
= rb
->user_page
;
4823 * Disable preemption so as to not let the corresponding user-space
4824 * spin too long if we get preempted.
4829 userpg
->index
= perf_event_index(event
);
4830 userpg
->offset
= perf_event_count(event
);
4832 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4834 userpg
->time_enabled
= enabled
+
4835 atomic64_read(&event
->child_total_time_enabled
);
4837 userpg
->time_running
= running
+
4838 atomic64_read(&event
->child_total_time_running
);
4840 arch_perf_update_userpage(event
, userpg
, now
);
4849 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4851 struct perf_event
*event
= vma
->vm_file
->private_data
;
4852 struct ring_buffer
*rb
;
4853 int ret
= VM_FAULT_SIGBUS
;
4855 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4856 if (vmf
->pgoff
== 0)
4862 rb
= rcu_dereference(event
->rb
);
4866 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4869 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4873 get_page(vmf
->page
);
4874 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4875 vmf
->page
->index
= vmf
->pgoff
;
4884 static void ring_buffer_attach(struct perf_event
*event
,
4885 struct ring_buffer
*rb
)
4887 struct ring_buffer
*old_rb
= NULL
;
4888 unsigned long flags
;
4892 * Should be impossible, we set this when removing
4893 * event->rb_entry and wait/clear when adding event->rb_entry.
4895 WARN_ON_ONCE(event
->rcu_pending
);
4898 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4899 list_del_rcu(&event
->rb_entry
);
4900 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4902 event
->rcu_batches
= get_state_synchronize_rcu();
4903 event
->rcu_pending
= 1;
4907 if (event
->rcu_pending
) {
4908 cond_synchronize_rcu(event
->rcu_batches
);
4909 event
->rcu_pending
= 0;
4912 spin_lock_irqsave(&rb
->event_lock
, flags
);
4913 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4914 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4918 * Avoid racing with perf_mmap_close(AUX): stop the event
4919 * before swizzling the event::rb pointer; if it's getting
4920 * unmapped, its aux_mmap_count will be 0 and it won't
4921 * restart. See the comment in __perf_pmu_output_stop().
4923 * Data will inevitably be lost when set_output is done in
4924 * mid-air, but then again, whoever does it like this is
4925 * not in for the data anyway.
4928 perf_event_stop(event
, 0);
4930 rcu_assign_pointer(event
->rb
, rb
);
4933 ring_buffer_put(old_rb
);
4935 * Since we detached before setting the new rb, so that we
4936 * could attach the new rb, we could have missed a wakeup.
4939 wake_up_all(&event
->waitq
);
4943 static void ring_buffer_wakeup(struct perf_event
*event
)
4945 struct ring_buffer
*rb
;
4948 rb
= rcu_dereference(event
->rb
);
4950 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4951 wake_up_all(&event
->waitq
);
4956 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4958 struct ring_buffer
*rb
;
4961 rb
= rcu_dereference(event
->rb
);
4963 if (!atomic_inc_not_zero(&rb
->refcount
))
4971 void ring_buffer_put(struct ring_buffer
*rb
)
4973 if (!atomic_dec_and_test(&rb
->refcount
))
4976 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4978 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4981 static void perf_mmap_open(struct vm_area_struct
*vma
)
4983 struct perf_event
*event
= vma
->vm_file
->private_data
;
4985 atomic_inc(&event
->mmap_count
);
4986 atomic_inc(&event
->rb
->mmap_count
);
4989 atomic_inc(&event
->rb
->aux_mmap_count
);
4991 if (event
->pmu
->event_mapped
)
4992 event
->pmu
->event_mapped(event
);
4995 static void perf_pmu_output_stop(struct perf_event
*event
);
4998 * A buffer can be mmap()ed multiple times; either directly through the same
4999 * event, or through other events by use of perf_event_set_output().
5001 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5002 * the buffer here, where we still have a VM context. This means we need
5003 * to detach all events redirecting to us.
5005 static void perf_mmap_close(struct vm_area_struct
*vma
)
5007 struct perf_event
*event
= vma
->vm_file
->private_data
;
5009 struct ring_buffer
*rb
= ring_buffer_get(event
);
5010 struct user_struct
*mmap_user
= rb
->mmap_user
;
5011 int mmap_locked
= rb
->mmap_locked
;
5012 unsigned long size
= perf_data_size(rb
);
5014 if (event
->pmu
->event_unmapped
)
5015 event
->pmu
->event_unmapped(event
);
5018 * rb->aux_mmap_count will always drop before rb->mmap_count and
5019 * event->mmap_count, so it is ok to use event->mmap_mutex to
5020 * serialize with perf_mmap here.
5022 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5023 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5025 * Stop all AUX events that are writing to this buffer,
5026 * so that we can free its AUX pages and corresponding PMU
5027 * data. Note that after rb::aux_mmap_count dropped to zero,
5028 * they won't start any more (see perf_aux_output_begin()).
5030 perf_pmu_output_stop(event
);
5032 /* now it's safe to free the pages */
5033 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5034 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5036 /* this has to be the last one */
5038 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5040 mutex_unlock(&event
->mmap_mutex
);
5043 atomic_dec(&rb
->mmap_count
);
5045 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5048 ring_buffer_attach(event
, NULL
);
5049 mutex_unlock(&event
->mmap_mutex
);
5051 /* If there's still other mmap()s of this buffer, we're done. */
5052 if (atomic_read(&rb
->mmap_count
))
5056 * No other mmap()s, detach from all other events that might redirect
5057 * into the now unreachable buffer. Somewhat complicated by the
5058 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5062 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5063 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5065 * This event is en-route to free_event() which will
5066 * detach it and remove it from the list.
5072 mutex_lock(&event
->mmap_mutex
);
5074 * Check we didn't race with perf_event_set_output() which can
5075 * swizzle the rb from under us while we were waiting to
5076 * acquire mmap_mutex.
5078 * If we find a different rb; ignore this event, a next
5079 * iteration will no longer find it on the list. We have to
5080 * still restart the iteration to make sure we're not now
5081 * iterating the wrong list.
5083 if (event
->rb
== rb
)
5084 ring_buffer_attach(event
, NULL
);
5086 mutex_unlock(&event
->mmap_mutex
);
5090 * Restart the iteration; either we're on the wrong list or
5091 * destroyed its integrity by doing a deletion.
5098 * It could be there's still a few 0-ref events on the list; they'll
5099 * get cleaned up by free_event() -- they'll also still have their
5100 * ref on the rb and will free it whenever they are done with it.
5102 * Aside from that, this buffer is 'fully' detached and unmapped,
5103 * undo the VM accounting.
5106 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5107 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5108 free_uid(mmap_user
);
5111 ring_buffer_put(rb
); /* could be last */
5114 static const struct vm_operations_struct perf_mmap_vmops
= {
5115 .open
= perf_mmap_open
,
5116 .close
= perf_mmap_close
, /* non mergable */
5117 .fault
= perf_mmap_fault
,
5118 .page_mkwrite
= perf_mmap_fault
,
5121 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5123 struct perf_event
*event
= file
->private_data
;
5124 unsigned long user_locked
, user_lock_limit
;
5125 struct user_struct
*user
= current_user();
5126 unsigned long locked
, lock_limit
;
5127 struct ring_buffer
*rb
= NULL
;
5128 unsigned long vma_size
;
5129 unsigned long nr_pages
;
5130 long user_extra
= 0, extra
= 0;
5131 int ret
= 0, flags
= 0;
5134 * Don't allow mmap() of inherited per-task counters. This would
5135 * create a performance issue due to all children writing to the
5138 if (event
->cpu
== -1 && event
->attr
.inherit
)
5141 if (!(vma
->vm_flags
& VM_SHARED
))
5144 vma_size
= vma
->vm_end
- vma
->vm_start
;
5146 if (vma
->vm_pgoff
== 0) {
5147 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5150 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5151 * mapped, all subsequent mappings should have the same size
5152 * and offset. Must be above the normal perf buffer.
5154 u64 aux_offset
, aux_size
;
5159 nr_pages
= vma_size
/ PAGE_SIZE
;
5161 mutex_lock(&event
->mmap_mutex
);
5168 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
5169 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
5171 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5174 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5177 /* already mapped with a different offset */
5178 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5181 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5184 /* already mapped with a different size */
5185 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5188 if (!is_power_of_2(nr_pages
))
5191 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5194 if (rb_has_aux(rb
)) {
5195 atomic_inc(&rb
->aux_mmap_count
);
5200 atomic_set(&rb
->aux_mmap_count
, 1);
5201 user_extra
= nr_pages
;
5207 * If we have rb pages ensure they're a power-of-two number, so we
5208 * can do bitmasks instead of modulo.
5210 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5213 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5216 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5218 mutex_lock(&event
->mmap_mutex
);
5220 if (event
->rb
->nr_pages
!= nr_pages
) {
5225 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5227 * Raced against perf_mmap_close() through
5228 * perf_event_set_output(). Try again, hope for better
5231 mutex_unlock(&event
->mmap_mutex
);
5238 user_extra
= nr_pages
+ 1;
5241 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5244 * Increase the limit linearly with more CPUs:
5246 user_lock_limit
*= num_online_cpus();
5248 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5250 if (user_locked
> user_lock_limit
)
5251 extra
= user_locked
- user_lock_limit
;
5253 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5254 lock_limit
>>= PAGE_SHIFT
;
5255 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5257 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5258 !capable(CAP_IPC_LOCK
)) {
5263 WARN_ON(!rb
&& event
->rb
);
5265 if (vma
->vm_flags
& VM_WRITE
)
5266 flags
|= RING_BUFFER_WRITABLE
;
5269 rb
= rb_alloc(nr_pages
,
5270 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5278 atomic_set(&rb
->mmap_count
, 1);
5279 rb
->mmap_user
= get_current_user();
5280 rb
->mmap_locked
= extra
;
5282 ring_buffer_attach(event
, rb
);
5284 perf_event_init_userpage(event
);
5285 perf_event_update_userpage(event
);
5287 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5288 event
->attr
.aux_watermark
, flags
);
5290 rb
->aux_mmap_locked
= extra
;
5295 atomic_long_add(user_extra
, &user
->locked_vm
);
5296 vma
->vm_mm
->pinned_vm
+= extra
;
5298 atomic_inc(&event
->mmap_count
);
5300 atomic_dec(&rb
->mmap_count
);
5303 mutex_unlock(&event
->mmap_mutex
);
5306 * Since pinned accounting is per vm we cannot allow fork() to copy our
5309 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5310 vma
->vm_ops
= &perf_mmap_vmops
;
5312 if (event
->pmu
->event_mapped
)
5313 event
->pmu
->event_mapped(event
);
5318 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5320 struct inode
*inode
= file_inode(filp
);
5321 struct perf_event
*event
= filp
->private_data
;
5325 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5326 inode_unlock(inode
);
5334 static const struct file_operations perf_fops
= {
5335 .llseek
= no_llseek
,
5336 .release
= perf_release
,
5339 .unlocked_ioctl
= perf_ioctl
,
5340 .compat_ioctl
= perf_compat_ioctl
,
5342 .fasync
= perf_fasync
,
5348 * If there's data, ensure we set the poll() state and publish everything
5349 * to user-space before waking everybody up.
5352 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5354 /* only the parent has fasync state */
5356 event
= event
->parent
;
5357 return &event
->fasync
;
5360 void perf_event_wakeup(struct perf_event
*event
)
5362 ring_buffer_wakeup(event
);
5364 if (event
->pending_kill
) {
5365 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5366 event
->pending_kill
= 0;
5370 static void perf_pending_event(struct irq_work
*entry
)
5372 struct perf_event
*event
= container_of(entry
,
5373 struct perf_event
, pending
);
5376 rctx
= perf_swevent_get_recursion_context();
5378 * If we 'fail' here, that's OK, it means recursion is already disabled
5379 * and we won't recurse 'further'.
5382 if (event
->pending_disable
) {
5383 event
->pending_disable
= 0;
5384 perf_event_disable_local(event
);
5387 if (event
->pending_wakeup
) {
5388 event
->pending_wakeup
= 0;
5389 perf_event_wakeup(event
);
5393 perf_swevent_put_recursion_context(rctx
);
5397 * We assume there is only KVM supporting the callbacks.
5398 * Later on, we might change it to a list if there is
5399 * another virtualization implementation supporting the callbacks.
5401 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5403 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5405 perf_guest_cbs
= cbs
;
5408 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5410 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5412 perf_guest_cbs
= NULL
;
5415 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5418 perf_output_sample_regs(struct perf_output_handle
*handle
,
5419 struct pt_regs
*regs
, u64 mask
)
5422 DECLARE_BITMAP(_mask
, 64);
5424 bitmap_from_u64(_mask
, mask
);
5425 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5428 val
= perf_reg_value(regs
, bit
);
5429 perf_output_put(handle
, val
);
5433 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5434 struct pt_regs
*regs
,
5435 struct pt_regs
*regs_user_copy
)
5437 if (user_mode(regs
)) {
5438 regs_user
->abi
= perf_reg_abi(current
);
5439 regs_user
->regs
= regs
;
5440 } else if (current
->mm
) {
5441 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5443 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5444 regs_user
->regs
= NULL
;
5448 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5449 struct pt_regs
*regs
)
5451 regs_intr
->regs
= regs
;
5452 regs_intr
->abi
= perf_reg_abi(current
);
5457 * Get remaining task size from user stack pointer.
5459 * It'd be better to take stack vma map and limit this more
5460 * precisly, but there's no way to get it safely under interrupt,
5461 * so using TASK_SIZE as limit.
5463 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5465 unsigned long addr
= perf_user_stack_pointer(regs
);
5467 if (!addr
|| addr
>= TASK_SIZE
)
5470 return TASK_SIZE
- addr
;
5474 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5475 struct pt_regs
*regs
)
5479 /* No regs, no stack pointer, no dump. */
5484 * Check if we fit in with the requested stack size into the:
5486 * If we don't, we limit the size to the TASK_SIZE.
5488 * - remaining sample size
5489 * If we don't, we customize the stack size to
5490 * fit in to the remaining sample size.
5493 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5494 stack_size
= min(stack_size
, (u16
) task_size
);
5496 /* Current header size plus static size and dynamic size. */
5497 header_size
+= 2 * sizeof(u64
);
5499 /* Do we fit in with the current stack dump size? */
5500 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5502 * If we overflow the maximum size for the sample,
5503 * we customize the stack dump size to fit in.
5505 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5506 stack_size
= round_up(stack_size
, sizeof(u64
));
5513 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5514 struct pt_regs
*regs
)
5516 /* Case of a kernel thread, nothing to dump */
5519 perf_output_put(handle
, size
);
5528 * - the size requested by user or the best one we can fit
5529 * in to the sample max size
5531 * - user stack dump data
5533 * - the actual dumped size
5537 perf_output_put(handle
, dump_size
);
5540 sp
= perf_user_stack_pointer(regs
);
5541 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5542 dyn_size
= dump_size
- rem
;
5544 perf_output_skip(handle
, rem
);
5547 perf_output_put(handle
, dyn_size
);
5551 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5552 struct perf_sample_data
*data
,
5553 struct perf_event
*event
)
5555 u64 sample_type
= event
->attr
.sample_type
;
5557 data
->type
= sample_type
;
5558 header
->size
+= event
->id_header_size
;
5560 if (sample_type
& PERF_SAMPLE_TID
) {
5561 /* namespace issues */
5562 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5563 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5566 if (sample_type
& PERF_SAMPLE_TIME
)
5567 data
->time
= perf_event_clock(event
);
5569 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5570 data
->id
= primary_event_id(event
);
5572 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5573 data
->stream_id
= event
->id
;
5575 if (sample_type
& PERF_SAMPLE_CPU
) {
5576 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5577 data
->cpu_entry
.reserved
= 0;
5581 void perf_event_header__init_id(struct perf_event_header
*header
,
5582 struct perf_sample_data
*data
,
5583 struct perf_event
*event
)
5585 if (event
->attr
.sample_id_all
)
5586 __perf_event_header__init_id(header
, data
, event
);
5589 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5590 struct perf_sample_data
*data
)
5592 u64 sample_type
= data
->type
;
5594 if (sample_type
& PERF_SAMPLE_TID
)
5595 perf_output_put(handle
, data
->tid_entry
);
5597 if (sample_type
& PERF_SAMPLE_TIME
)
5598 perf_output_put(handle
, data
->time
);
5600 if (sample_type
& PERF_SAMPLE_ID
)
5601 perf_output_put(handle
, data
->id
);
5603 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5604 perf_output_put(handle
, data
->stream_id
);
5606 if (sample_type
& PERF_SAMPLE_CPU
)
5607 perf_output_put(handle
, data
->cpu_entry
);
5609 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5610 perf_output_put(handle
, data
->id
);
5613 void perf_event__output_id_sample(struct perf_event
*event
,
5614 struct perf_output_handle
*handle
,
5615 struct perf_sample_data
*sample
)
5617 if (event
->attr
.sample_id_all
)
5618 __perf_event__output_id_sample(handle
, sample
);
5621 static void perf_output_read_one(struct perf_output_handle
*handle
,
5622 struct perf_event
*event
,
5623 u64 enabled
, u64 running
)
5625 u64 read_format
= event
->attr
.read_format
;
5629 values
[n
++] = perf_event_count(event
);
5630 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5631 values
[n
++] = enabled
+
5632 atomic64_read(&event
->child_total_time_enabled
);
5634 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5635 values
[n
++] = running
+
5636 atomic64_read(&event
->child_total_time_running
);
5638 if (read_format
& PERF_FORMAT_ID
)
5639 values
[n
++] = primary_event_id(event
);
5641 __output_copy(handle
, values
, n
* sizeof(u64
));
5645 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5647 static void perf_output_read_group(struct perf_output_handle
*handle
,
5648 struct perf_event
*event
,
5649 u64 enabled
, u64 running
)
5651 struct perf_event
*leader
= event
->group_leader
, *sub
;
5652 u64 read_format
= event
->attr
.read_format
;
5656 values
[n
++] = 1 + leader
->nr_siblings
;
5658 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5659 values
[n
++] = enabled
;
5661 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5662 values
[n
++] = running
;
5664 if (leader
!= event
)
5665 leader
->pmu
->read(leader
);
5667 values
[n
++] = perf_event_count(leader
);
5668 if (read_format
& PERF_FORMAT_ID
)
5669 values
[n
++] = primary_event_id(leader
);
5671 __output_copy(handle
, values
, n
* sizeof(u64
));
5673 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5676 if ((sub
!= event
) &&
5677 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5678 sub
->pmu
->read(sub
);
5680 values
[n
++] = perf_event_count(sub
);
5681 if (read_format
& PERF_FORMAT_ID
)
5682 values
[n
++] = primary_event_id(sub
);
5684 __output_copy(handle
, values
, n
* sizeof(u64
));
5688 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5689 PERF_FORMAT_TOTAL_TIME_RUNNING)
5691 static void perf_output_read(struct perf_output_handle
*handle
,
5692 struct perf_event
*event
)
5694 u64 enabled
= 0, running
= 0, now
;
5695 u64 read_format
= event
->attr
.read_format
;
5698 * compute total_time_enabled, total_time_running
5699 * based on snapshot values taken when the event
5700 * was last scheduled in.
5702 * we cannot simply called update_context_time()
5703 * because of locking issue as we are called in
5706 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5707 calc_timer_values(event
, &now
, &enabled
, &running
);
5709 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5710 perf_output_read_group(handle
, event
, enabled
, running
);
5712 perf_output_read_one(handle
, event
, enabled
, running
);
5715 void perf_output_sample(struct perf_output_handle
*handle
,
5716 struct perf_event_header
*header
,
5717 struct perf_sample_data
*data
,
5718 struct perf_event
*event
)
5720 u64 sample_type
= data
->type
;
5722 perf_output_put(handle
, *header
);
5724 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5725 perf_output_put(handle
, data
->id
);
5727 if (sample_type
& PERF_SAMPLE_IP
)
5728 perf_output_put(handle
, data
->ip
);
5730 if (sample_type
& PERF_SAMPLE_TID
)
5731 perf_output_put(handle
, data
->tid_entry
);
5733 if (sample_type
& PERF_SAMPLE_TIME
)
5734 perf_output_put(handle
, data
->time
);
5736 if (sample_type
& PERF_SAMPLE_ADDR
)
5737 perf_output_put(handle
, data
->addr
);
5739 if (sample_type
& PERF_SAMPLE_ID
)
5740 perf_output_put(handle
, data
->id
);
5742 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5743 perf_output_put(handle
, data
->stream_id
);
5745 if (sample_type
& PERF_SAMPLE_CPU
)
5746 perf_output_put(handle
, data
->cpu_entry
);
5748 if (sample_type
& PERF_SAMPLE_PERIOD
)
5749 perf_output_put(handle
, data
->period
);
5751 if (sample_type
& PERF_SAMPLE_READ
)
5752 perf_output_read(handle
, event
);
5754 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5755 if (data
->callchain
) {
5758 if (data
->callchain
)
5759 size
+= data
->callchain
->nr
;
5761 size
*= sizeof(u64
);
5763 __output_copy(handle
, data
->callchain
, size
);
5766 perf_output_put(handle
, nr
);
5770 if (sample_type
& PERF_SAMPLE_RAW
) {
5771 struct perf_raw_record
*raw
= data
->raw
;
5774 struct perf_raw_frag
*frag
= &raw
->frag
;
5776 perf_output_put(handle
, raw
->size
);
5779 __output_custom(handle
, frag
->copy
,
5780 frag
->data
, frag
->size
);
5782 __output_copy(handle
, frag
->data
,
5785 if (perf_raw_frag_last(frag
))
5790 __output_skip(handle
, NULL
, frag
->pad
);
5796 .size
= sizeof(u32
),
5799 perf_output_put(handle
, raw
);
5803 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5804 if (data
->br_stack
) {
5807 size
= data
->br_stack
->nr
5808 * sizeof(struct perf_branch_entry
);
5810 perf_output_put(handle
, data
->br_stack
->nr
);
5811 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5814 * we always store at least the value of nr
5817 perf_output_put(handle
, nr
);
5821 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5822 u64 abi
= data
->regs_user
.abi
;
5825 * If there are no regs to dump, notice it through
5826 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5828 perf_output_put(handle
, abi
);
5831 u64 mask
= event
->attr
.sample_regs_user
;
5832 perf_output_sample_regs(handle
,
5833 data
->regs_user
.regs
,
5838 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5839 perf_output_sample_ustack(handle
,
5840 data
->stack_user_size
,
5841 data
->regs_user
.regs
);
5844 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5845 perf_output_put(handle
, data
->weight
);
5847 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5848 perf_output_put(handle
, data
->data_src
.val
);
5850 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5851 perf_output_put(handle
, data
->txn
);
5853 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5854 u64 abi
= data
->regs_intr
.abi
;
5856 * If there are no regs to dump, notice it through
5857 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5859 perf_output_put(handle
, abi
);
5862 u64 mask
= event
->attr
.sample_regs_intr
;
5864 perf_output_sample_regs(handle
,
5865 data
->regs_intr
.regs
,
5870 if (!event
->attr
.watermark
) {
5871 int wakeup_events
= event
->attr
.wakeup_events
;
5873 if (wakeup_events
) {
5874 struct ring_buffer
*rb
= handle
->rb
;
5875 int events
= local_inc_return(&rb
->events
);
5877 if (events
>= wakeup_events
) {
5878 local_sub(wakeup_events
, &rb
->events
);
5879 local_inc(&rb
->wakeup
);
5885 void perf_prepare_sample(struct perf_event_header
*header
,
5886 struct perf_sample_data
*data
,
5887 struct perf_event
*event
,
5888 struct pt_regs
*regs
)
5890 u64 sample_type
= event
->attr
.sample_type
;
5892 header
->type
= PERF_RECORD_SAMPLE
;
5893 header
->size
= sizeof(*header
) + event
->header_size
;
5896 header
->misc
|= perf_misc_flags(regs
);
5898 __perf_event_header__init_id(header
, data
, event
);
5900 if (sample_type
& PERF_SAMPLE_IP
)
5901 data
->ip
= perf_instruction_pointer(regs
);
5903 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5906 data
->callchain
= perf_callchain(event
, regs
);
5908 if (data
->callchain
)
5909 size
+= data
->callchain
->nr
;
5911 header
->size
+= size
* sizeof(u64
);
5914 if (sample_type
& PERF_SAMPLE_RAW
) {
5915 struct perf_raw_record
*raw
= data
->raw
;
5919 struct perf_raw_frag
*frag
= &raw
->frag
;
5924 if (perf_raw_frag_last(frag
))
5929 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
5930 raw
->size
= size
- sizeof(u32
);
5931 frag
->pad
= raw
->size
- sum
;
5936 header
->size
+= size
;
5939 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5940 int size
= sizeof(u64
); /* nr */
5941 if (data
->br_stack
) {
5942 size
+= data
->br_stack
->nr
5943 * sizeof(struct perf_branch_entry
);
5945 header
->size
+= size
;
5948 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5949 perf_sample_regs_user(&data
->regs_user
, regs
,
5950 &data
->regs_user_copy
);
5952 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5953 /* regs dump ABI info */
5954 int size
= sizeof(u64
);
5956 if (data
->regs_user
.regs
) {
5957 u64 mask
= event
->attr
.sample_regs_user
;
5958 size
+= hweight64(mask
) * sizeof(u64
);
5961 header
->size
+= size
;
5964 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5966 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5967 * processed as the last one or have additional check added
5968 * in case new sample type is added, because we could eat
5969 * up the rest of the sample size.
5971 u16 stack_size
= event
->attr
.sample_stack_user
;
5972 u16 size
= sizeof(u64
);
5974 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5975 data
->regs_user
.regs
);
5978 * If there is something to dump, add space for the dump
5979 * itself and for the field that tells the dynamic size,
5980 * which is how many have been actually dumped.
5983 size
+= sizeof(u64
) + stack_size
;
5985 data
->stack_user_size
= stack_size
;
5986 header
->size
+= size
;
5989 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5990 /* regs dump ABI info */
5991 int size
= sizeof(u64
);
5993 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5995 if (data
->regs_intr
.regs
) {
5996 u64 mask
= event
->attr
.sample_regs_intr
;
5998 size
+= hweight64(mask
) * sizeof(u64
);
6001 header
->size
+= size
;
6005 static void __always_inline
6006 __perf_event_output(struct perf_event
*event
,
6007 struct perf_sample_data
*data
,
6008 struct pt_regs
*regs
,
6009 int (*output_begin
)(struct perf_output_handle
*,
6010 struct perf_event
*,
6013 struct perf_output_handle handle
;
6014 struct perf_event_header header
;
6016 /* protect the callchain buffers */
6019 perf_prepare_sample(&header
, data
, event
, regs
);
6021 if (output_begin(&handle
, event
, header
.size
))
6024 perf_output_sample(&handle
, &header
, data
, event
);
6026 perf_output_end(&handle
);
6033 perf_event_output_forward(struct perf_event
*event
,
6034 struct perf_sample_data
*data
,
6035 struct pt_regs
*regs
)
6037 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6041 perf_event_output_backward(struct perf_event
*event
,
6042 struct perf_sample_data
*data
,
6043 struct pt_regs
*regs
)
6045 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6049 perf_event_output(struct perf_event
*event
,
6050 struct perf_sample_data
*data
,
6051 struct pt_regs
*regs
)
6053 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6060 struct perf_read_event
{
6061 struct perf_event_header header
;
6068 perf_event_read_event(struct perf_event
*event
,
6069 struct task_struct
*task
)
6071 struct perf_output_handle handle
;
6072 struct perf_sample_data sample
;
6073 struct perf_read_event read_event
= {
6075 .type
= PERF_RECORD_READ
,
6077 .size
= sizeof(read_event
) + event
->read_size
,
6079 .pid
= perf_event_pid(event
, task
),
6080 .tid
= perf_event_tid(event
, task
),
6084 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6085 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6089 perf_output_put(&handle
, read_event
);
6090 perf_output_read(&handle
, event
);
6091 perf_event__output_id_sample(event
, &handle
, &sample
);
6093 perf_output_end(&handle
);
6096 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6099 perf_iterate_ctx(struct perf_event_context
*ctx
,
6100 perf_iterate_f output
,
6101 void *data
, bool all
)
6103 struct perf_event
*event
;
6105 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6107 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6109 if (!event_filter_match(event
))
6113 output(event
, data
);
6117 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6119 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6120 struct perf_event
*event
;
6122 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6124 * Skip events that are not fully formed yet; ensure that
6125 * if we observe event->ctx, both event and ctx will be
6126 * complete enough. See perf_install_in_context().
6128 if (!smp_load_acquire(&event
->ctx
))
6131 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6133 if (!event_filter_match(event
))
6135 output(event
, data
);
6140 * Iterate all events that need to receive side-band events.
6142 * For new callers; ensure that account_pmu_sb_event() includes
6143 * your event, otherwise it might not get delivered.
6146 perf_iterate_sb(perf_iterate_f output
, void *data
,
6147 struct perf_event_context
*task_ctx
)
6149 struct perf_event_context
*ctx
;
6156 * If we have task_ctx != NULL we only notify the task context itself.
6157 * The task_ctx is set only for EXIT events before releasing task
6161 perf_iterate_ctx(task_ctx
, output
, data
, false);
6165 perf_iterate_sb_cpu(output
, data
);
6167 for_each_task_context_nr(ctxn
) {
6168 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6170 perf_iterate_ctx(ctx
, output
, data
, false);
6178 * Clear all file-based filters at exec, they'll have to be
6179 * re-instated when/if these objects are mmapped again.
6181 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6183 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6184 struct perf_addr_filter
*filter
;
6185 unsigned int restart
= 0, count
= 0;
6186 unsigned long flags
;
6188 if (!has_addr_filter(event
))
6191 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6192 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6193 if (filter
->inode
) {
6194 event
->addr_filters_offs
[count
] = 0;
6202 event
->addr_filters_gen
++;
6203 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6206 perf_event_stop(event
, 1);
6209 void perf_event_exec(void)
6211 struct perf_event_context
*ctx
;
6215 for_each_task_context_nr(ctxn
) {
6216 ctx
= current
->perf_event_ctxp
[ctxn
];
6220 perf_event_enable_on_exec(ctxn
);
6222 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6228 struct remote_output
{
6229 struct ring_buffer
*rb
;
6233 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6235 struct perf_event
*parent
= event
->parent
;
6236 struct remote_output
*ro
= data
;
6237 struct ring_buffer
*rb
= ro
->rb
;
6238 struct stop_event_data sd
= {
6242 if (!has_aux(event
))
6249 * In case of inheritance, it will be the parent that links to the
6250 * ring-buffer, but it will be the child that's actually using it.
6252 * We are using event::rb to determine if the event should be stopped,
6253 * however this may race with ring_buffer_attach() (through set_output),
6254 * which will make us skip the event that actually needs to be stopped.
6255 * So ring_buffer_attach() has to stop an aux event before re-assigning
6258 if (rcu_dereference(parent
->rb
) == rb
)
6259 ro
->err
= __perf_event_stop(&sd
);
6262 static int __perf_pmu_output_stop(void *info
)
6264 struct perf_event
*event
= info
;
6265 struct pmu
*pmu
= event
->pmu
;
6266 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6267 struct remote_output ro
= {
6272 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6273 if (cpuctx
->task_ctx
)
6274 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6281 static void perf_pmu_output_stop(struct perf_event
*event
)
6283 struct perf_event
*iter
;
6288 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6290 * For per-CPU events, we need to make sure that neither they
6291 * nor their children are running; for cpu==-1 events it's
6292 * sufficient to stop the event itself if it's active, since
6293 * it can't have children.
6297 cpu
= READ_ONCE(iter
->oncpu
);
6302 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6303 if (err
== -EAGAIN
) {
6312 * task tracking -- fork/exit
6314 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6317 struct perf_task_event
{
6318 struct task_struct
*task
;
6319 struct perf_event_context
*task_ctx
;
6322 struct perf_event_header header
;
6332 static int perf_event_task_match(struct perf_event
*event
)
6334 return event
->attr
.comm
|| event
->attr
.mmap
||
6335 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6339 static void perf_event_task_output(struct perf_event
*event
,
6342 struct perf_task_event
*task_event
= data
;
6343 struct perf_output_handle handle
;
6344 struct perf_sample_data sample
;
6345 struct task_struct
*task
= task_event
->task
;
6346 int ret
, size
= task_event
->event_id
.header
.size
;
6348 if (!perf_event_task_match(event
))
6351 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6353 ret
= perf_output_begin(&handle
, event
,
6354 task_event
->event_id
.header
.size
);
6358 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6359 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6361 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6362 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6364 task_event
->event_id
.time
= perf_event_clock(event
);
6366 perf_output_put(&handle
, task_event
->event_id
);
6368 perf_event__output_id_sample(event
, &handle
, &sample
);
6370 perf_output_end(&handle
);
6372 task_event
->event_id
.header
.size
= size
;
6375 static void perf_event_task(struct task_struct
*task
,
6376 struct perf_event_context
*task_ctx
,
6379 struct perf_task_event task_event
;
6381 if (!atomic_read(&nr_comm_events
) &&
6382 !atomic_read(&nr_mmap_events
) &&
6383 !atomic_read(&nr_task_events
))
6386 task_event
= (struct perf_task_event
){
6388 .task_ctx
= task_ctx
,
6391 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6393 .size
= sizeof(task_event
.event_id
),
6403 perf_iterate_sb(perf_event_task_output
,
6408 void perf_event_fork(struct task_struct
*task
)
6410 perf_event_task(task
, NULL
, 1);
6417 struct perf_comm_event
{
6418 struct task_struct
*task
;
6423 struct perf_event_header header
;
6430 static int perf_event_comm_match(struct perf_event
*event
)
6432 return event
->attr
.comm
;
6435 static void perf_event_comm_output(struct perf_event
*event
,
6438 struct perf_comm_event
*comm_event
= data
;
6439 struct perf_output_handle handle
;
6440 struct perf_sample_data sample
;
6441 int size
= comm_event
->event_id
.header
.size
;
6444 if (!perf_event_comm_match(event
))
6447 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6448 ret
= perf_output_begin(&handle
, event
,
6449 comm_event
->event_id
.header
.size
);
6454 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6455 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6457 perf_output_put(&handle
, comm_event
->event_id
);
6458 __output_copy(&handle
, comm_event
->comm
,
6459 comm_event
->comm_size
);
6461 perf_event__output_id_sample(event
, &handle
, &sample
);
6463 perf_output_end(&handle
);
6465 comm_event
->event_id
.header
.size
= size
;
6468 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6470 char comm
[TASK_COMM_LEN
];
6473 memset(comm
, 0, sizeof(comm
));
6474 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6475 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6477 comm_event
->comm
= comm
;
6478 comm_event
->comm_size
= size
;
6480 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6482 perf_iterate_sb(perf_event_comm_output
,
6487 void perf_event_comm(struct task_struct
*task
, bool exec
)
6489 struct perf_comm_event comm_event
;
6491 if (!atomic_read(&nr_comm_events
))
6494 comm_event
= (struct perf_comm_event
){
6500 .type
= PERF_RECORD_COMM
,
6501 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6509 perf_event_comm_event(&comm_event
);
6516 struct perf_mmap_event
{
6517 struct vm_area_struct
*vma
;
6519 const char *file_name
;
6527 struct perf_event_header header
;
6537 static int perf_event_mmap_match(struct perf_event
*event
,
6540 struct perf_mmap_event
*mmap_event
= data
;
6541 struct vm_area_struct
*vma
= mmap_event
->vma
;
6542 int executable
= vma
->vm_flags
& VM_EXEC
;
6544 return (!executable
&& event
->attr
.mmap_data
) ||
6545 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6548 static void perf_event_mmap_output(struct perf_event
*event
,
6551 struct perf_mmap_event
*mmap_event
= data
;
6552 struct perf_output_handle handle
;
6553 struct perf_sample_data sample
;
6554 int size
= mmap_event
->event_id
.header
.size
;
6557 if (!perf_event_mmap_match(event
, data
))
6560 if (event
->attr
.mmap2
) {
6561 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6562 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6563 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6564 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6565 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6566 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6567 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6570 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6571 ret
= perf_output_begin(&handle
, event
,
6572 mmap_event
->event_id
.header
.size
);
6576 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6577 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6579 perf_output_put(&handle
, mmap_event
->event_id
);
6581 if (event
->attr
.mmap2
) {
6582 perf_output_put(&handle
, mmap_event
->maj
);
6583 perf_output_put(&handle
, mmap_event
->min
);
6584 perf_output_put(&handle
, mmap_event
->ino
);
6585 perf_output_put(&handle
, mmap_event
->ino_generation
);
6586 perf_output_put(&handle
, mmap_event
->prot
);
6587 perf_output_put(&handle
, mmap_event
->flags
);
6590 __output_copy(&handle
, mmap_event
->file_name
,
6591 mmap_event
->file_size
);
6593 perf_event__output_id_sample(event
, &handle
, &sample
);
6595 perf_output_end(&handle
);
6597 mmap_event
->event_id
.header
.size
= size
;
6600 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6602 struct vm_area_struct
*vma
= mmap_event
->vma
;
6603 struct file
*file
= vma
->vm_file
;
6604 int maj
= 0, min
= 0;
6605 u64 ino
= 0, gen
= 0;
6606 u32 prot
= 0, flags
= 0;
6613 struct inode
*inode
;
6616 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6622 * d_path() works from the end of the rb backwards, so we
6623 * need to add enough zero bytes after the string to handle
6624 * the 64bit alignment we do later.
6626 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6631 inode
= file_inode(vma
->vm_file
);
6632 dev
= inode
->i_sb
->s_dev
;
6634 gen
= inode
->i_generation
;
6638 if (vma
->vm_flags
& VM_READ
)
6640 if (vma
->vm_flags
& VM_WRITE
)
6642 if (vma
->vm_flags
& VM_EXEC
)
6645 if (vma
->vm_flags
& VM_MAYSHARE
)
6648 flags
= MAP_PRIVATE
;
6650 if (vma
->vm_flags
& VM_DENYWRITE
)
6651 flags
|= MAP_DENYWRITE
;
6652 if (vma
->vm_flags
& VM_MAYEXEC
)
6653 flags
|= MAP_EXECUTABLE
;
6654 if (vma
->vm_flags
& VM_LOCKED
)
6655 flags
|= MAP_LOCKED
;
6656 if (vma
->vm_flags
& VM_HUGETLB
)
6657 flags
|= MAP_HUGETLB
;
6661 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6662 name
= (char *) vma
->vm_ops
->name(vma
);
6667 name
= (char *)arch_vma_name(vma
);
6671 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6672 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6676 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6677 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6687 strlcpy(tmp
, name
, sizeof(tmp
));
6691 * Since our buffer works in 8 byte units we need to align our string
6692 * size to a multiple of 8. However, we must guarantee the tail end is
6693 * zero'd out to avoid leaking random bits to userspace.
6695 size
= strlen(name
)+1;
6696 while (!IS_ALIGNED(size
, sizeof(u64
)))
6697 name
[size
++] = '\0';
6699 mmap_event
->file_name
= name
;
6700 mmap_event
->file_size
= size
;
6701 mmap_event
->maj
= maj
;
6702 mmap_event
->min
= min
;
6703 mmap_event
->ino
= ino
;
6704 mmap_event
->ino_generation
= gen
;
6705 mmap_event
->prot
= prot
;
6706 mmap_event
->flags
= flags
;
6708 if (!(vma
->vm_flags
& VM_EXEC
))
6709 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6711 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6713 perf_iterate_sb(perf_event_mmap_output
,
6721 * Check whether inode and address range match filter criteria.
6723 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
6724 struct file
*file
, unsigned long offset
,
6727 if (filter
->inode
!= file_inode(file
))
6730 if (filter
->offset
> offset
+ size
)
6733 if (filter
->offset
+ filter
->size
< offset
)
6739 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
6741 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6742 struct vm_area_struct
*vma
= data
;
6743 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
6744 struct file
*file
= vma
->vm_file
;
6745 struct perf_addr_filter
*filter
;
6746 unsigned int restart
= 0, count
= 0;
6748 if (!has_addr_filter(event
))
6754 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6755 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6756 if (perf_addr_filter_match(filter
, file
, off
,
6757 vma
->vm_end
- vma
->vm_start
)) {
6758 event
->addr_filters_offs
[count
] = vma
->vm_start
;
6766 event
->addr_filters_gen
++;
6767 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6770 perf_event_stop(event
, 1);
6774 * Adjust all task's events' filters to the new vma
6776 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
6778 struct perf_event_context
*ctx
;
6782 * Data tracing isn't supported yet and as such there is no need
6783 * to keep track of anything that isn't related to executable code:
6785 if (!(vma
->vm_flags
& VM_EXEC
))
6789 for_each_task_context_nr(ctxn
) {
6790 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6794 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
6799 void perf_event_mmap(struct vm_area_struct
*vma
)
6801 struct perf_mmap_event mmap_event
;
6803 if (!atomic_read(&nr_mmap_events
))
6806 mmap_event
= (struct perf_mmap_event
){
6812 .type
= PERF_RECORD_MMAP
,
6813 .misc
= PERF_RECORD_MISC_USER
,
6818 .start
= vma
->vm_start
,
6819 .len
= vma
->vm_end
- vma
->vm_start
,
6820 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6822 /* .maj (attr_mmap2 only) */
6823 /* .min (attr_mmap2 only) */
6824 /* .ino (attr_mmap2 only) */
6825 /* .ino_generation (attr_mmap2 only) */
6826 /* .prot (attr_mmap2 only) */
6827 /* .flags (attr_mmap2 only) */
6830 perf_addr_filters_adjust(vma
);
6831 perf_event_mmap_event(&mmap_event
);
6834 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6835 unsigned long size
, u64 flags
)
6837 struct perf_output_handle handle
;
6838 struct perf_sample_data sample
;
6839 struct perf_aux_event
{
6840 struct perf_event_header header
;
6846 .type
= PERF_RECORD_AUX
,
6848 .size
= sizeof(rec
),
6856 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6857 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6862 perf_output_put(&handle
, rec
);
6863 perf_event__output_id_sample(event
, &handle
, &sample
);
6865 perf_output_end(&handle
);
6869 * Lost/dropped samples logging
6871 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6873 struct perf_output_handle handle
;
6874 struct perf_sample_data sample
;
6878 struct perf_event_header header
;
6880 } lost_samples_event
= {
6882 .type
= PERF_RECORD_LOST_SAMPLES
,
6884 .size
= sizeof(lost_samples_event
),
6889 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6891 ret
= perf_output_begin(&handle
, event
,
6892 lost_samples_event
.header
.size
);
6896 perf_output_put(&handle
, lost_samples_event
);
6897 perf_event__output_id_sample(event
, &handle
, &sample
);
6898 perf_output_end(&handle
);
6902 * context_switch tracking
6905 struct perf_switch_event
{
6906 struct task_struct
*task
;
6907 struct task_struct
*next_prev
;
6910 struct perf_event_header header
;
6916 static int perf_event_switch_match(struct perf_event
*event
)
6918 return event
->attr
.context_switch
;
6921 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6923 struct perf_switch_event
*se
= data
;
6924 struct perf_output_handle handle
;
6925 struct perf_sample_data sample
;
6928 if (!perf_event_switch_match(event
))
6931 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6932 if (event
->ctx
->task
) {
6933 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6934 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6936 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6937 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6938 se
->event_id
.next_prev_pid
=
6939 perf_event_pid(event
, se
->next_prev
);
6940 se
->event_id
.next_prev_tid
=
6941 perf_event_tid(event
, se
->next_prev
);
6944 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6946 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6950 if (event
->ctx
->task
)
6951 perf_output_put(&handle
, se
->event_id
.header
);
6953 perf_output_put(&handle
, se
->event_id
);
6955 perf_event__output_id_sample(event
, &handle
, &sample
);
6957 perf_output_end(&handle
);
6960 static void perf_event_switch(struct task_struct
*task
,
6961 struct task_struct
*next_prev
, bool sched_in
)
6963 struct perf_switch_event switch_event
;
6965 /* N.B. caller checks nr_switch_events != 0 */
6967 switch_event
= (struct perf_switch_event
){
6969 .next_prev
= next_prev
,
6973 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6976 /* .next_prev_pid */
6977 /* .next_prev_tid */
6981 perf_iterate_sb(perf_event_switch_output
,
6987 * IRQ throttle logging
6990 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6992 struct perf_output_handle handle
;
6993 struct perf_sample_data sample
;
6997 struct perf_event_header header
;
7001 } throttle_event
= {
7003 .type
= PERF_RECORD_THROTTLE
,
7005 .size
= sizeof(throttle_event
),
7007 .time
= perf_event_clock(event
),
7008 .id
= primary_event_id(event
),
7009 .stream_id
= event
->id
,
7013 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7015 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7017 ret
= perf_output_begin(&handle
, event
,
7018 throttle_event
.header
.size
);
7022 perf_output_put(&handle
, throttle_event
);
7023 perf_event__output_id_sample(event
, &handle
, &sample
);
7024 perf_output_end(&handle
);
7027 static void perf_log_itrace_start(struct perf_event
*event
)
7029 struct perf_output_handle handle
;
7030 struct perf_sample_data sample
;
7031 struct perf_aux_event
{
7032 struct perf_event_header header
;
7039 event
= event
->parent
;
7041 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7042 event
->hw
.itrace_started
)
7045 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7046 rec
.header
.misc
= 0;
7047 rec
.header
.size
= sizeof(rec
);
7048 rec
.pid
= perf_event_pid(event
, current
);
7049 rec
.tid
= perf_event_tid(event
, current
);
7051 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7052 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7057 perf_output_put(&handle
, rec
);
7058 perf_event__output_id_sample(event
, &handle
, &sample
);
7060 perf_output_end(&handle
);
7064 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7066 struct hw_perf_event
*hwc
= &event
->hw
;
7070 seq
= __this_cpu_read(perf_throttled_seq
);
7071 if (seq
!= hwc
->interrupts_seq
) {
7072 hwc
->interrupts_seq
= seq
;
7073 hwc
->interrupts
= 1;
7076 if (unlikely(throttle
7077 && hwc
->interrupts
>= max_samples_per_tick
)) {
7078 __this_cpu_inc(perf_throttled_count
);
7079 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7080 hwc
->interrupts
= MAX_INTERRUPTS
;
7081 perf_log_throttle(event
, 0);
7086 if (event
->attr
.freq
) {
7087 u64 now
= perf_clock();
7088 s64 delta
= now
- hwc
->freq_time_stamp
;
7090 hwc
->freq_time_stamp
= now
;
7092 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7093 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7099 int perf_event_account_interrupt(struct perf_event
*event
)
7101 return __perf_event_account_interrupt(event
, 1);
7105 * Generic event overflow handling, sampling.
7108 static int __perf_event_overflow(struct perf_event
*event
,
7109 int throttle
, struct perf_sample_data
*data
,
7110 struct pt_regs
*regs
)
7112 int events
= atomic_read(&event
->event_limit
);
7116 * Non-sampling counters might still use the PMI to fold short
7117 * hardware counters, ignore those.
7119 if (unlikely(!is_sampling_event(event
)))
7122 ret
= __perf_event_account_interrupt(event
, throttle
);
7125 * XXX event_limit might not quite work as expected on inherited
7129 event
->pending_kill
= POLL_IN
;
7130 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7132 event
->pending_kill
= POLL_HUP
;
7134 perf_event_disable_inatomic(event
);
7137 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7139 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7140 event
->pending_wakeup
= 1;
7141 irq_work_queue(&event
->pending
);
7147 int perf_event_overflow(struct perf_event
*event
,
7148 struct perf_sample_data
*data
,
7149 struct pt_regs
*regs
)
7151 return __perf_event_overflow(event
, 1, data
, regs
);
7155 * Generic software event infrastructure
7158 struct swevent_htable
{
7159 struct swevent_hlist
*swevent_hlist
;
7160 struct mutex hlist_mutex
;
7163 /* Recursion avoidance in each contexts */
7164 int recursion
[PERF_NR_CONTEXTS
];
7167 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7170 * We directly increment event->count and keep a second value in
7171 * event->hw.period_left to count intervals. This period event
7172 * is kept in the range [-sample_period, 0] so that we can use the
7176 u64
perf_swevent_set_period(struct perf_event
*event
)
7178 struct hw_perf_event
*hwc
= &event
->hw
;
7179 u64 period
= hwc
->last_period
;
7183 hwc
->last_period
= hwc
->sample_period
;
7186 old
= val
= local64_read(&hwc
->period_left
);
7190 nr
= div64_u64(period
+ val
, period
);
7191 offset
= nr
* period
;
7193 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7199 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7200 struct perf_sample_data
*data
,
7201 struct pt_regs
*regs
)
7203 struct hw_perf_event
*hwc
= &event
->hw
;
7207 overflow
= perf_swevent_set_period(event
);
7209 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7212 for (; overflow
; overflow
--) {
7213 if (__perf_event_overflow(event
, throttle
,
7216 * We inhibit the overflow from happening when
7217 * hwc->interrupts == MAX_INTERRUPTS.
7225 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7226 struct perf_sample_data
*data
,
7227 struct pt_regs
*regs
)
7229 struct hw_perf_event
*hwc
= &event
->hw
;
7231 local64_add(nr
, &event
->count
);
7236 if (!is_sampling_event(event
))
7239 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7241 return perf_swevent_overflow(event
, 1, data
, regs
);
7243 data
->period
= event
->hw
.last_period
;
7245 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7246 return perf_swevent_overflow(event
, 1, data
, regs
);
7248 if (local64_add_negative(nr
, &hwc
->period_left
))
7251 perf_swevent_overflow(event
, 0, data
, regs
);
7254 static int perf_exclude_event(struct perf_event
*event
,
7255 struct pt_regs
*regs
)
7257 if (event
->hw
.state
& PERF_HES_STOPPED
)
7261 if (event
->attr
.exclude_user
&& user_mode(regs
))
7264 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7271 static int perf_swevent_match(struct perf_event
*event
,
7272 enum perf_type_id type
,
7274 struct perf_sample_data
*data
,
7275 struct pt_regs
*regs
)
7277 if (event
->attr
.type
!= type
)
7280 if (event
->attr
.config
!= event_id
)
7283 if (perf_exclude_event(event
, regs
))
7289 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7291 u64 val
= event_id
| (type
<< 32);
7293 return hash_64(val
, SWEVENT_HLIST_BITS
);
7296 static inline struct hlist_head
*
7297 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7299 u64 hash
= swevent_hash(type
, event_id
);
7301 return &hlist
->heads
[hash
];
7304 /* For the read side: events when they trigger */
7305 static inline struct hlist_head
*
7306 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7308 struct swevent_hlist
*hlist
;
7310 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7314 return __find_swevent_head(hlist
, type
, event_id
);
7317 /* For the event head insertion and removal in the hlist */
7318 static inline struct hlist_head
*
7319 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7321 struct swevent_hlist
*hlist
;
7322 u32 event_id
= event
->attr
.config
;
7323 u64 type
= event
->attr
.type
;
7326 * Event scheduling is always serialized against hlist allocation
7327 * and release. Which makes the protected version suitable here.
7328 * The context lock guarantees that.
7330 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7331 lockdep_is_held(&event
->ctx
->lock
));
7335 return __find_swevent_head(hlist
, type
, event_id
);
7338 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7340 struct perf_sample_data
*data
,
7341 struct pt_regs
*regs
)
7343 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7344 struct perf_event
*event
;
7345 struct hlist_head
*head
;
7348 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7352 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7353 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7354 perf_swevent_event(event
, nr
, data
, regs
);
7360 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7362 int perf_swevent_get_recursion_context(void)
7364 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7366 return get_recursion_context(swhash
->recursion
);
7368 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7370 void perf_swevent_put_recursion_context(int rctx
)
7372 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7374 put_recursion_context(swhash
->recursion
, rctx
);
7377 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7379 struct perf_sample_data data
;
7381 if (WARN_ON_ONCE(!regs
))
7384 perf_sample_data_init(&data
, addr
, 0);
7385 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7388 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7392 preempt_disable_notrace();
7393 rctx
= perf_swevent_get_recursion_context();
7394 if (unlikely(rctx
< 0))
7397 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7399 perf_swevent_put_recursion_context(rctx
);
7401 preempt_enable_notrace();
7404 static void perf_swevent_read(struct perf_event
*event
)
7408 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7410 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7411 struct hw_perf_event
*hwc
= &event
->hw
;
7412 struct hlist_head
*head
;
7414 if (is_sampling_event(event
)) {
7415 hwc
->last_period
= hwc
->sample_period
;
7416 perf_swevent_set_period(event
);
7419 hwc
->state
= !(flags
& PERF_EF_START
);
7421 head
= find_swevent_head(swhash
, event
);
7422 if (WARN_ON_ONCE(!head
))
7425 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7426 perf_event_update_userpage(event
);
7431 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7433 hlist_del_rcu(&event
->hlist_entry
);
7436 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7438 event
->hw
.state
= 0;
7441 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7443 event
->hw
.state
= PERF_HES_STOPPED
;
7446 /* Deref the hlist from the update side */
7447 static inline struct swevent_hlist
*
7448 swevent_hlist_deref(struct swevent_htable
*swhash
)
7450 return rcu_dereference_protected(swhash
->swevent_hlist
,
7451 lockdep_is_held(&swhash
->hlist_mutex
));
7454 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7456 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7461 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7462 kfree_rcu(hlist
, rcu_head
);
7465 static void swevent_hlist_put_cpu(int cpu
)
7467 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7469 mutex_lock(&swhash
->hlist_mutex
);
7471 if (!--swhash
->hlist_refcount
)
7472 swevent_hlist_release(swhash
);
7474 mutex_unlock(&swhash
->hlist_mutex
);
7477 static void swevent_hlist_put(void)
7481 for_each_possible_cpu(cpu
)
7482 swevent_hlist_put_cpu(cpu
);
7485 static int swevent_hlist_get_cpu(int cpu
)
7487 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7490 mutex_lock(&swhash
->hlist_mutex
);
7491 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
7492 struct swevent_hlist
*hlist
;
7494 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7499 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7501 swhash
->hlist_refcount
++;
7503 mutex_unlock(&swhash
->hlist_mutex
);
7508 static int swevent_hlist_get(void)
7510 int err
, cpu
, failed_cpu
;
7513 for_each_possible_cpu(cpu
) {
7514 err
= swevent_hlist_get_cpu(cpu
);
7524 for_each_possible_cpu(cpu
) {
7525 if (cpu
== failed_cpu
)
7527 swevent_hlist_put_cpu(cpu
);
7534 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7536 static void sw_perf_event_destroy(struct perf_event
*event
)
7538 u64 event_id
= event
->attr
.config
;
7540 WARN_ON(event
->parent
);
7542 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7543 swevent_hlist_put();
7546 static int perf_swevent_init(struct perf_event
*event
)
7548 u64 event_id
= event
->attr
.config
;
7550 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7554 * no branch sampling for software events
7556 if (has_branch_stack(event
))
7560 case PERF_COUNT_SW_CPU_CLOCK
:
7561 case PERF_COUNT_SW_TASK_CLOCK
:
7568 if (event_id
>= PERF_COUNT_SW_MAX
)
7571 if (!event
->parent
) {
7574 err
= swevent_hlist_get();
7578 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7579 event
->destroy
= sw_perf_event_destroy
;
7585 static struct pmu perf_swevent
= {
7586 .task_ctx_nr
= perf_sw_context
,
7588 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7590 .event_init
= perf_swevent_init
,
7591 .add
= perf_swevent_add
,
7592 .del
= perf_swevent_del
,
7593 .start
= perf_swevent_start
,
7594 .stop
= perf_swevent_stop
,
7595 .read
= perf_swevent_read
,
7598 #ifdef CONFIG_EVENT_TRACING
7600 static int perf_tp_filter_match(struct perf_event
*event
,
7601 struct perf_sample_data
*data
)
7603 void *record
= data
->raw
->frag
.data
;
7605 /* only top level events have filters set */
7607 event
= event
->parent
;
7609 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7614 static int perf_tp_event_match(struct perf_event
*event
,
7615 struct perf_sample_data
*data
,
7616 struct pt_regs
*regs
)
7618 if (event
->hw
.state
& PERF_HES_STOPPED
)
7621 * All tracepoints are from kernel-space.
7623 if (event
->attr
.exclude_kernel
)
7626 if (!perf_tp_filter_match(event
, data
))
7632 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7633 struct trace_event_call
*call
, u64 count
,
7634 struct pt_regs
*regs
, struct hlist_head
*head
,
7635 struct task_struct
*task
)
7637 struct bpf_prog
*prog
= call
->prog
;
7640 *(struct pt_regs
**)raw_data
= regs
;
7641 if (!trace_call_bpf(prog
, raw_data
) || hlist_empty(head
)) {
7642 perf_swevent_put_recursion_context(rctx
);
7646 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7649 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7651 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7652 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7653 struct task_struct
*task
)
7655 struct perf_sample_data data
;
7656 struct perf_event
*event
;
7658 struct perf_raw_record raw
= {
7665 perf_sample_data_init(&data
, 0, 0);
7668 perf_trace_buf_update(record
, event_type
);
7670 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7671 if (perf_tp_event_match(event
, &data
, regs
))
7672 perf_swevent_event(event
, count
, &data
, regs
);
7676 * If we got specified a target task, also iterate its context and
7677 * deliver this event there too.
7679 if (task
&& task
!= current
) {
7680 struct perf_event_context
*ctx
;
7681 struct trace_entry
*entry
= record
;
7684 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7688 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7689 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7691 if (event
->attr
.config
!= entry
->type
)
7693 if (perf_tp_event_match(event
, &data
, regs
))
7694 perf_swevent_event(event
, count
, &data
, regs
);
7700 perf_swevent_put_recursion_context(rctx
);
7702 EXPORT_SYMBOL_GPL(perf_tp_event
);
7704 static void tp_perf_event_destroy(struct perf_event
*event
)
7706 perf_trace_destroy(event
);
7709 static int perf_tp_event_init(struct perf_event
*event
)
7713 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7717 * no branch sampling for tracepoint events
7719 if (has_branch_stack(event
))
7722 err
= perf_trace_init(event
);
7726 event
->destroy
= tp_perf_event_destroy
;
7731 static struct pmu perf_tracepoint
= {
7732 .task_ctx_nr
= perf_sw_context
,
7734 .event_init
= perf_tp_event_init
,
7735 .add
= perf_trace_add
,
7736 .del
= perf_trace_del
,
7737 .start
= perf_swevent_start
,
7738 .stop
= perf_swevent_stop
,
7739 .read
= perf_swevent_read
,
7742 static inline void perf_tp_register(void)
7744 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7747 static void perf_event_free_filter(struct perf_event
*event
)
7749 ftrace_profile_free_filter(event
);
7752 #ifdef CONFIG_BPF_SYSCALL
7753 static void bpf_overflow_handler(struct perf_event
*event
,
7754 struct perf_sample_data
*data
,
7755 struct pt_regs
*regs
)
7757 struct bpf_perf_event_data_kern ctx
= {
7764 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
7767 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
7770 __this_cpu_dec(bpf_prog_active
);
7775 event
->orig_overflow_handler(event
, data
, regs
);
7778 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
7780 struct bpf_prog
*prog
;
7782 if (event
->overflow_handler_context
)
7783 /* hw breakpoint or kernel counter */
7789 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
7791 return PTR_ERR(prog
);
7794 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
7795 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
7799 static void perf_event_free_bpf_handler(struct perf_event
*event
)
7801 struct bpf_prog
*prog
= event
->prog
;
7806 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
7811 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
7815 static void perf_event_free_bpf_handler(struct perf_event
*event
)
7820 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7822 bool is_kprobe
, is_tracepoint
;
7823 struct bpf_prog
*prog
;
7825 if (event
->attr
.type
== PERF_TYPE_HARDWARE
||
7826 event
->attr
.type
== PERF_TYPE_SOFTWARE
)
7827 return perf_event_set_bpf_handler(event
, prog_fd
);
7829 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7832 if (event
->tp_event
->prog
)
7835 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
7836 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
7837 if (!is_kprobe
&& !is_tracepoint
)
7838 /* bpf programs can only be attached to u/kprobe or tracepoint */
7841 prog
= bpf_prog_get(prog_fd
);
7843 return PTR_ERR(prog
);
7845 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
7846 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
7847 /* valid fd, but invalid bpf program type */
7852 if (is_tracepoint
) {
7853 int off
= trace_event_get_offsets(event
->tp_event
);
7855 if (prog
->aux
->max_ctx_offset
> off
) {
7860 event
->tp_event
->prog
= prog
;
7865 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7867 struct bpf_prog
*prog
;
7869 perf_event_free_bpf_handler(event
);
7871 if (!event
->tp_event
)
7874 prog
= event
->tp_event
->prog
;
7876 event
->tp_event
->prog
= NULL
;
7883 static inline void perf_tp_register(void)
7887 static void perf_event_free_filter(struct perf_event
*event
)
7891 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7896 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7899 #endif /* CONFIG_EVENT_TRACING */
7901 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7902 void perf_bp_event(struct perf_event
*bp
, void *data
)
7904 struct perf_sample_data sample
;
7905 struct pt_regs
*regs
= data
;
7907 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7909 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7910 perf_swevent_event(bp
, 1, &sample
, regs
);
7915 * Allocate a new address filter
7917 static struct perf_addr_filter
*
7918 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
7920 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
7921 struct perf_addr_filter
*filter
;
7923 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
7927 INIT_LIST_HEAD(&filter
->entry
);
7928 list_add_tail(&filter
->entry
, filters
);
7933 static void free_filters_list(struct list_head
*filters
)
7935 struct perf_addr_filter
*filter
, *iter
;
7937 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
7939 iput(filter
->inode
);
7940 list_del(&filter
->entry
);
7946 * Free existing address filters and optionally install new ones
7948 static void perf_addr_filters_splice(struct perf_event
*event
,
7949 struct list_head
*head
)
7951 unsigned long flags
;
7954 if (!has_addr_filter(event
))
7957 /* don't bother with children, they don't have their own filters */
7961 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
7963 list_splice_init(&event
->addr_filters
.list
, &list
);
7965 list_splice(head
, &event
->addr_filters
.list
);
7967 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
7969 free_filters_list(&list
);
7973 * Scan through mm's vmas and see if one of them matches the
7974 * @filter; if so, adjust filter's address range.
7975 * Called with mm::mmap_sem down for reading.
7977 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
7978 struct mm_struct
*mm
)
7980 struct vm_area_struct
*vma
;
7982 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
7983 struct file
*file
= vma
->vm_file
;
7984 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
7985 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
7990 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
7993 return vma
->vm_start
;
8000 * Update event's address range filters based on the
8001 * task's existing mappings, if any.
8003 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8005 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8006 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8007 struct perf_addr_filter
*filter
;
8008 struct mm_struct
*mm
= NULL
;
8009 unsigned int count
= 0;
8010 unsigned long flags
;
8013 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8014 * will stop on the parent's child_mutex that our caller is also holding
8016 if (task
== TASK_TOMBSTONE
)
8019 mm
= get_task_mm(event
->ctx
->task
);
8023 down_read(&mm
->mmap_sem
);
8025 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8026 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8027 event
->addr_filters_offs
[count
] = 0;
8030 * Adjust base offset if the filter is associated to a binary
8031 * that needs to be mapped:
8034 event
->addr_filters_offs
[count
] =
8035 perf_addr_filter_apply(filter
, mm
);
8040 event
->addr_filters_gen
++;
8041 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8043 up_read(&mm
->mmap_sem
);
8048 perf_event_stop(event
, 1);
8052 * Address range filtering: limiting the data to certain
8053 * instruction address ranges. Filters are ioctl()ed to us from
8054 * userspace as ascii strings.
8056 * Filter string format:
8059 * where ACTION is one of the
8060 * * "filter": limit the trace to this region
8061 * * "start": start tracing from this address
8062 * * "stop": stop tracing at this address/region;
8064 * * for kernel addresses: <start address>[/<size>]
8065 * * for object files: <start address>[/<size>]@</path/to/object/file>
8067 * if <size> is not specified, the range is treated as a single address.
8081 IF_STATE_ACTION
= 0,
8086 static const match_table_t if_tokens
= {
8087 { IF_ACT_FILTER
, "filter" },
8088 { IF_ACT_START
, "start" },
8089 { IF_ACT_STOP
, "stop" },
8090 { IF_SRC_FILE
, "%u/%u@%s" },
8091 { IF_SRC_KERNEL
, "%u/%u" },
8092 { IF_SRC_FILEADDR
, "%u@%s" },
8093 { IF_SRC_KERNELADDR
, "%u" },
8094 { IF_ACT_NONE
, NULL
},
8098 * Address filter string parser
8101 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8102 struct list_head
*filters
)
8104 struct perf_addr_filter
*filter
= NULL
;
8105 char *start
, *orig
, *filename
= NULL
;
8107 substring_t args
[MAX_OPT_ARGS
];
8108 int state
= IF_STATE_ACTION
, token
;
8109 unsigned int kernel
= 0;
8112 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8116 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8122 /* filter definition begins */
8123 if (state
== IF_STATE_ACTION
) {
8124 filter
= perf_addr_filter_new(event
, filters
);
8129 token
= match_token(start
, if_tokens
, args
);
8136 if (state
!= IF_STATE_ACTION
)
8139 state
= IF_STATE_SOURCE
;
8142 case IF_SRC_KERNELADDR
:
8146 case IF_SRC_FILEADDR
:
8148 if (state
!= IF_STATE_SOURCE
)
8151 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8155 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8159 if (filter
->range
) {
8161 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8166 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8167 int fpos
= filter
->range
? 2 : 1;
8169 filename
= match_strdup(&args
[fpos
]);
8176 state
= IF_STATE_END
;
8184 * Filter definition is fully parsed, validate and install it.
8185 * Make sure that it doesn't contradict itself or the event's
8188 if (state
== IF_STATE_END
) {
8189 if (kernel
&& event
->attr
.exclude_kernel
)
8196 /* look up the path and grab its inode */
8197 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8199 goto fail_free_name
;
8201 filter
->inode
= igrab(d_inode(path
.dentry
));
8207 if (!filter
->inode
||
8208 !S_ISREG(filter
->inode
->i_mode
))
8209 /* free_filters_list() will iput() */
8213 /* ready to consume more filters */
8214 state
= IF_STATE_ACTION
;
8219 if (state
!= IF_STATE_ACTION
)
8229 free_filters_list(filters
);
8236 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8242 * Since this is called in perf_ioctl() path, we're already holding
8245 lockdep_assert_held(&event
->ctx
->mutex
);
8247 if (WARN_ON_ONCE(event
->parent
))
8251 * For now, we only support filtering in per-task events; doing so
8252 * for CPU-wide events requires additional context switching trickery,
8253 * since same object code will be mapped at different virtual
8254 * addresses in different processes.
8256 if (!event
->ctx
->task
)
8259 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8263 ret
= event
->pmu
->addr_filters_validate(&filters
);
8265 free_filters_list(&filters
);
8269 /* remove existing filters, if any */
8270 perf_addr_filters_splice(event
, &filters
);
8272 /* install new filters */
8273 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8278 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8283 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8284 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8285 !has_addr_filter(event
))
8288 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8289 if (IS_ERR(filter_str
))
8290 return PTR_ERR(filter_str
);
8292 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8293 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8294 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
8296 else if (has_addr_filter(event
))
8297 ret
= perf_event_set_addr_filter(event
, filter_str
);
8304 * hrtimer based swevent callback
8307 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8309 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8310 struct perf_sample_data data
;
8311 struct pt_regs
*regs
;
8312 struct perf_event
*event
;
8315 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8317 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8318 return HRTIMER_NORESTART
;
8320 event
->pmu
->read(event
);
8322 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8323 regs
= get_irq_regs();
8325 if (regs
&& !perf_exclude_event(event
, regs
)) {
8326 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8327 if (__perf_event_overflow(event
, 1, &data
, regs
))
8328 ret
= HRTIMER_NORESTART
;
8331 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8332 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8337 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8339 struct hw_perf_event
*hwc
= &event
->hw
;
8342 if (!is_sampling_event(event
))
8345 period
= local64_read(&hwc
->period_left
);
8350 local64_set(&hwc
->period_left
, 0);
8352 period
= max_t(u64
, 10000, hwc
->sample_period
);
8354 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8355 HRTIMER_MODE_REL_PINNED
);
8358 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8360 struct hw_perf_event
*hwc
= &event
->hw
;
8362 if (is_sampling_event(event
)) {
8363 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8364 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8366 hrtimer_cancel(&hwc
->hrtimer
);
8370 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8372 struct hw_perf_event
*hwc
= &event
->hw
;
8374 if (!is_sampling_event(event
))
8377 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8378 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8381 * Since hrtimers have a fixed rate, we can do a static freq->period
8382 * mapping and avoid the whole period adjust feedback stuff.
8384 if (event
->attr
.freq
) {
8385 long freq
= event
->attr
.sample_freq
;
8387 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8388 hwc
->sample_period
= event
->attr
.sample_period
;
8389 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8390 hwc
->last_period
= hwc
->sample_period
;
8391 event
->attr
.freq
= 0;
8396 * Software event: cpu wall time clock
8399 static void cpu_clock_event_update(struct perf_event
*event
)
8404 now
= local_clock();
8405 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8406 local64_add(now
- prev
, &event
->count
);
8409 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8411 local64_set(&event
->hw
.prev_count
, local_clock());
8412 perf_swevent_start_hrtimer(event
);
8415 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8417 perf_swevent_cancel_hrtimer(event
);
8418 cpu_clock_event_update(event
);
8421 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8423 if (flags
& PERF_EF_START
)
8424 cpu_clock_event_start(event
, flags
);
8425 perf_event_update_userpage(event
);
8430 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8432 cpu_clock_event_stop(event
, flags
);
8435 static void cpu_clock_event_read(struct perf_event
*event
)
8437 cpu_clock_event_update(event
);
8440 static int cpu_clock_event_init(struct perf_event
*event
)
8442 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8445 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8449 * no branch sampling for software events
8451 if (has_branch_stack(event
))
8454 perf_swevent_init_hrtimer(event
);
8459 static struct pmu perf_cpu_clock
= {
8460 .task_ctx_nr
= perf_sw_context
,
8462 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8464 .event_init
= cpu_clock_event_init
,
8465 .add
= cpu_clock_event_add
,
8466 .del
= cpu_clock_event_del
,
8467 .start
= cpu_clock_event_start
,
8468 .stop
= cpu_clock_event_stop
,
8469 .read
= cpu_clock_event_read
,
8473 * Software event: task time clock
8476 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8481 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8483 local64_add(delta
, &event
->count
);
8486 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8488 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8489 perf_swevent_start_hrtimer(event
);
8492 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8494 perf_swevent_cancel_hrtimer(event
);
8495 task_clock_event_update(event
, event
->ctx
->time
);
8498 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8500 if (flags
& PERF_EF_START
)
8501 task_clock_event_start(event
, flags
);
8502 perf_event_update_userpage(event
);
8507 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8509 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8512 static void task_clock_event_read(struct perf_event
*event
)
8514 u64 now
= perf_clock();
8515 u64 delta
= now
- event
->ctx
->timestamp
;
8516 u64 time
= event
->ctx
->time
+ delta
;
8518 task_clock_event_update(event
, time
);
8521 static int task_clock_event_init(struct perf_event
*event
)
8523 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8526 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8530 * no branch sampling for software events
8532 if (has_branch_stack(event
))
8535 perf_swevent_init_hrtimer(event
);
8540 static struct pmu perf_task_clock
= {
8541 .task_ctx_nr
= perf_sw_context
,
8543 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8545 .event_init
= task_clock_event_init
,
8546 .add
= task_clock_event_add
,
8547 .del
= task_clock_event_del
,
8548 .start
= task_clock_event_start
,
8549 .stop
= task_clock_event_stop
,
8550 .read
= task_clock_event_read
,
8553 static void perf_pmu_nop_void(struct pmu
*pmu
)
8557 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8561 static int perf_pmu_nop_int(struct pmu
*pmu
)
8566 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8568 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8570 __this_cpu_write(nop_txn_flags
, flags
);
8572 if (flags
& ~PERF_PMU_TXN_ADD
)
8575 perf_pmu_disable(pmu
);
8578 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8580 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8582 __this_cpu_write(nop_txn_flags
, 0);
8584 if (flags
& ~PERF_PMU_TXN_ADD
)
8587 perf_pmu_enable(pmu
);
8591 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8593 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8595 __this_cpu_write(nop_txn_flags
, 0);
8597 if (flags
& ~PERF_PMU_TXN_ADD
)
8600 perf_pmu_enable(pmu
);
8603 static int perf_event_idx_default(struct perf_event
*event
)
8609 * Ensures all contexts with the same task_ctx_nr have the same
8610 * pmu_cpu_context too.
8612 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8619 list_for_each_entry(pmu
, &pmus
, entry
) {
8620 if (pmu
->task_ctx_nr
== ctxn
)
8621 return pmu
->pmu_cpu_context
;
8627 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
8631 for_each_possible_cpu(cpu
) {
8632 struct perf_cpu_context
*cpuctx
;
8634 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8636 if (cpuctx
->unique_pmu
== old_pmu
)
8637 cpuctx
->unique_pmu
= pmu
;
8641 static void free_pmu_context(struct pmu
*pmu
)
8645 mutex_lock(&pmus_lock
);
8647 * Like a real lame refcount.
8649 list_for_each_entry(i
, &pmus
, entry
) {
8650 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
8651 update_pmu_context(i
, pmu
);
8656 free_percpu(pmu
->pmu_cpu_context
);
8658 mutex_unlock(&pmus_lock
);
8662 * Let userspace know that this PMU supports address range filtering:
8664 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8665 struct device_attribute
*attr
,
8668 struct pmu
*pmu
= dev_get_drvdata(dev
);
8670 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8672 DEVICE_ATTR_RO(nr_addr_filters
);
8674 static struct idr pmu_idr
;
8677 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8679 struct pmu
*pmu
= dev_get_drvdata(dev
);
8681 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8683 static DEVICE_ATTR_RO(type
);
8686 perf_event_mux_interval_ms_show(struct device
*dev
,
8687 struct device_attribute
*attr
,
8690 struct pmu
*pmu
= dev_get_drvdata(dev
);
8692 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8695 static DEFINE_MUTEX(mux_interval_mutex
);
8698 perf_event_mux_interval_ms_store(struct device
*dev
,
8699 struct device_attribute
*attr
,
8700 const char *buf
, size_t count
)
8702 struct pmu
*pmu
= dev_get_drvdata(dev
);
8703 int timer
, cpu
, ret
;
8705 ret
= kstrtoint(buf
, 0, &timer
);
8712 /* same value, noting to do */
8713 if (timer
== pmu
->hrtimer_interval_ms
)
8716 mutex_lock(&mux_interval_mutex
);
8717 pmu
->hrtimer_interval_ms
= timer
;
8719 /* update all cpuctx for this PMU */
8721 for_each_online_cpu(cpu
) {
8722 struct perf_cpu_context
*cpuctx
;
8723 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8724 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
8726 cpu_function_call(cpu
,
8727 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
8730 mutex_unlock(&mux_interval_mutex
);
8734 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
8736 static struct attribute
*pmu_dev_attrs
[] = {
8737 &dev_attr_type
.attr
,
8738 &dev_attr_perf_event_mux_interval_ms
.attr
,
8741 ATTRIBUTE_GROUPS(pmu_dev
);
8743 static int pmu_bus_running
;
8744 static struct bus_type pmu_bus
= {
8745 .name
= "event_source",
8746 .dev_groups
= pmu_dev_groups
,
8749 static void pmu_dev_release(struct device
*dev
)
8754 static int pmu_dev_alloc(struct pmu
*pmu
)
8758 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
8762 pmu
->dev
->groups
= pmu
->attr_groups
;
8763 device_initialize(pmu
->dev
);
8764 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
8768 dev_set_drvdata(pmu
->dev
, pmu
);
8769 pmu
->dev
->bus
= &pmu_bus
;
8770 pmu
->dev
->release
= pmu_dev_release
;
8771 ret
= device_add(pmu
->dev
);
8775 /* For PMUs with address filters, throw in an extra attribute: */
8776 if (pmu
->nr_addr_filters
)
8777 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
8786 device_del(pmu
->dev
);
8789 put_device(pmu
->dev
);
8793 static struct lock_class_key cpuctx_mutex
;
8794 static struct lock_class_key cpuctx_lock
;
8796 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
8800 mutex_lock(&pmus_lock
);
8802 pmu
->pmu_disable_count
= alloc_percpu(int);
8803 if (!pmu
->pmu_disable_count
)
8812 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
8820 if (pmu_bus_running
) {
8821 ret
= pmu_dev_alloc(pmu
);
8827 if (pmu
->task_ctx_nr
== perf_hw_context
) {
8828 static int hw_context_taken
= 0;
8831 * Other than systems with heterogeneous CPUs, it never makes
8832 * sense for two PMUs to share perf_hw_context. PMUs which are
8833 * uncore must use perf_invalid_context.
8835 if (WARN_ON_ONCE(hw_context_taken
&&
8836 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
8837 pmu
->task_ctx_nr
= perf_invalid_context
;
8839 hw_context_taken
= 1;
8842 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
8843 if (pmu
->pmu_cpu_context
)
8844 goto got_cpu_context
;
8847 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
8848 if (!pmu
->pmu_cpu_context
)
8851 for_each_possible_cpu(cpu
) {
8852 struct perf_cpu_context
*cpuctx
;
8854 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8855 __perf_event_init_context(&cpuctx
->ctx
);
8856 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
8857 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
8858 cpuctx
->ctx
.pmu
= pmu
;
8860 __perf_mux_hrtimer_init(cpuctx
, cpu
);
8862 cpuctx
->unique_pmu
= pmu
;
8866 if (!pmu
->start_txn
) {
8867 if (pmu
->pmu_enable
) {
8869 * If we have pmu_enable/pmu_disable calls, install
8870 * transaction stubs that use that to try and batch
8871 * hardware accesses.
8873 pmu
->start_txn
= perf_pmu_start_txn
;
8874 pmu
->commit_txn
= perf_pmu_commit_txn
;
8875 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
8877 pmu
->start_txn
= perf_pmu_nop_txn
;
8878 pmu
->commit_txn
= perf_pmu_nop_int
;
8879 pmu
->cancel_txn
= perf_pmu_nop_void
;
8883 if (!pmu
->pmu_enable
) {
8884 pmu
->pmu_enable
= perf_pmu_nop_void
;
8885 pmu
->pmu_disable
= perf_pmu_nop_void
;
8888 if (!pmu
->event_idx
)
8889 pmu
->event_idx
= perf_event_idx_default
;
8891 list_add_rcu(&pmu
->entry
, &pmus
);
8892 atomic_set(&pmu
->exclusive_cnt
, 0);
8895 mutex_unlock(&pmus_lock
);
8900 device_del(pmu
->dev
);
8901 put_device(pmu
->dev
);
8904 if (pmu
->type
>= PERF_TYPE_MAX
)
8905 idr_remove(&pmu_idr
, pmu
->type
);
8908 free_percpu(pmu
->pmu_disable_count
);
8911 EXPORT_SYMBOL_GPL(perf_pmu_register
);
8913 void perf_pmu_unregister(struct pmu
*pmu
)
8917 mutex_lock(&pmus_lock
);
8918 remove_device
= pmu_bus_running
;
8919 list_del_rcu(&pmu
->entry
);
8920 mutex_unlock(&pmus_lock
);
8923 * We dereference the pmu list under both SRCU and regular RCU, so
8924 * synchronize against both of those.
8926 synchronize_srcu(&pmus_srcu
);
8929 free_percpu(pmu
->pmu_disable_count
);
8930 if (pmu
->type
>= PERF_TYPE_MAX
)
8931 idr_remove(&pmu_idr
, pmu
->type
);
8932 if (remove_device
) {
8933 if (pmu
->nr_addr_filters
)
8934 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
8935 device_del(pmu
->dev
);
8936 put_device(pmu
->dev
);
8938 free_pmu_context(pmu
);
8940 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
8942 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
8944 struct perf_event_context
*ctx
= NULL
;
8947 if (!try_module_get(pmu
->module
))
8950 if (event
->group_leader
!= event
) {
8952 * This ctx->mutex can nest when we're called through
8953 * inheritance. See the perf_event_ctx_lock_nested() comment.
8955 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
8956 SINGLE_DEPTH_NESTING
);
8961 ret
= pmu
->event_init(event
);
8964 perf_event_ctx_unlock(event
->group_leader
, ctx
);
8967 module_put(pmu
->module
);
8972 static struct pmu
*perf_init_event(struct perf_event
*event
)
8974 struct pmu
*pmu
= NULL
;
8978 idx
= srcu_read_lock(&pmus_srcu
);
8981 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
8984 ret
= perf_try_init_event(pmu
, event
);
8990 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
8991 ret
= perf_try_init_event(pmu
, event
);
8995 if (ret
!= -ENOENT
) {
9000 pmu
= ERR_PTR(-ENOENT
);
9002 srcu_read_unlock(&pmus_srcu
, idx
);
9007 static void attach_sb_event(struct perf_event
*event
)
9009 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9011 raw_spin_lock(&pel
->lock
);
9012 list_add_rcu(&event
->sb_list
, &pel
->list
);
9013 raw_spin_unlock(&pel
->lock
);
9017 * We keep a list of all !task (and therefore per-cpu) events
9018 * that need to receive side-band records.
9020 * This avoids having to scan all the various PMU per-cpu contexts
9023 static void account_pmu_sb_event(struct perf_event
*event
)
9025 if (is_sb_event(event
))
9026 attach_sb_event(event
);
9029 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9034 if (is_cgroup_event(event
))
9035 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9038 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9039 static void account_freq_event_nohz(void)
9041 #ifdef CONFIG_NO_HZ_FULL
9042 /* Lock so we don't race with concurrent unaccount */
9043 spin_lock(&nr_freq_lock
);
9044 if (atomic_inc_return(&nr_freq_events
) == 1)
9045 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9046 spin_unlock(&nr_freq_lock
);
9050 static void account_freq_event(void)
9052 if (tick_nohz_full_enabled())
9053 account_freq_event_nohz();
9055 atomic_inc(&nr_freq_events
);
9059 static void account_event(struct perf_event
*event
)
9066 if (event
->attach_state
& PERF_ATTACH_TASK
)
9068 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9069 atomic_inc(&nr_mmap_events
);
9070 if (event
->attr
.comm
)
9071 atomic_inc(&nr_comm_events
);
9072 if (event
->attr
.task
)
9073 atomic_inc(&nr_task_events
);
9074 if (event
->attr
.freq
)
9075 account_freq_event();
9076 if (event
->attr
.context_switch
) {
9077 atomic_inc(&nr_switch_events
);
9080 if (has_branch_stack(event
))
9082 if (is_cgroup_event(event
))
9086 if (atomic_inc_not_zero(&perf_sched_count
))
9089 mutex_lock(&perf_sched_mutex
);
9090 if (!atomic_read(&perf_sched_count
)) {
9091 static_branch_enable(&perf_sched_events
);
9093 * Guarantee that all CPUs observe they key change and
9094 * call the perf scheduling hooks before proceeding to
9095 * install events that need them.
9097 synchronize_sched();
9100 * Now that we have waited for the sync_sched(), allow further
9101 * increments to by-pass the mutex.
9103 atomic_inc(&perf_sched_count
);
9104 mutex_unlock(&perf_sched_mutex
);
9108 account_event_cpu(event
, event
->cpu
);
9110 account_pmu_sb_event(event
);
9114 * Allocate and initialize a event structure
9116 static struct perf_event
*
9117 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9118 struct task_struct
*task
,
9119 struct perf_event
*group_leader
,
9120 struct perf_event
*parent_event
,
9121 perf_overflow_handler_t overflow_handler
,
9122 void *context
, int cgroup_fd
)
9125 struct perf_event
*event
;
9126 struct hw_perf_event
*hwc
;
9129 if ((unsigned)cpu
>= nr_cpu_ids
) {
9130 if (!task
|| cpu
!= -1)
9131 return ERR_PTR(-EINVAL
);
9134 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9136 return ERR_PTR(-ENOMEM
);
9139 * Single events are their own group leaders, with an
9140 * empty sibling list:
9143 group_leader
= event
;
9145 mutex_init(&event
->child_mutex
);
9146 INIT_LIST_HEAD(&event
->child_list
);
9148 INIT_LIST_HEAD(&event
->group_entry
);
9149 INIT_LIST_HEAD(&event
->event_entry
);
9150 INIT_LIST_HEAD(&event
->sibling_list
);
9151 INIT_LIST_HEAD(&event
->rb_entry
);
9152 INIT_LIST_HEAD(&event
->active_entry
);
9153 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9154 INIT_HLIST_NODE(&event
->hlist_entry
);
9157 init_waitqueue_head(&event
->waitq
);
9158 init_irq_work(&event
->pending
, perf_pending_event
);
9160 mutex_init(&event
->mmap_mutex
);
9161 raw_spin_lock_init(&event
->addr_filters
.lock
);
9163 atomic_long_set(&event
->refcount
, 1);
9165 event
->attr
= *attr
;
9166 event
->group_leader
= group_leader
;
9170 event
->parent
= parent_event
;
9172 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9173 event
->id
= atomic64_inc_return(&perf_event_id
);
9175 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9178 event
->attach_state
= PERF_ATTACH_TASK
;
9180 * XXX pmu::event_init needs to know what task to account to
9181 * and we cannot use the ctx information because we need the
9182 * pmu before we get a ctx.
9184 event
->hw
.target
= task
;
9187 event
->clock
= &local_clock
;
9189 event
->clock
= parent_event
->clock
;
9191 if (!overflow_handler
&& parent_event
) {
9192 overflow_handler
= parent_event
->overflow_handler
;
9193 context
= parent_event
->overflow_handler_context
;
9194 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9195 if (overflow_handler
== bpf_overflow_handler
) {
9196 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9199 err
= PTR_ERR(prog
);
9203 event
->orig_overflow_handler
=
9204 parent_event
->orig_overflow_handler
;
9209 if (overflow_handler
) {
9210 event
->overflow_handler
= overflow_handler
;
9211 event
->overflow_handler_context
= context
;
9212 } else if (is_write_backward(event
)){
9213 event
->overflow_handler
= perf_event_output_backward
;
9214 event
->overflow_handler_context
= NULL
;
9216 event
->overflow_handler
= perf_event_output_forward
;
9217 event
->overflow_handler_context
= NULL
;
9220 perf_event__state_init(event
);
9225 hwc
->sample_period
= attr
->sample_period
;
9226 if (attr
->freq
&& attr
->sample_freq
)
9227 hwc
->sample_period
= 1;
9228 hwc
->last_period
= hwc
->sample_period
;
9230 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9233 * we currently do not support PERF_FORMAT_GROUP on inherited events
9235 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
9238 if (!has_branch_stack(event
))
9239 event
->attr
.branch_sample_type
= 0;
9241 if (cgroup_fd
!= -1) {
9242 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9247 pmu
= perf_init_event(event
);
9250 else if (IS_ERR(pmu
)) {
9255 err
= exclusive_event_init(event
);
9259 if (has_addr_filter(event
)) {
9260 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9261 sizeof(unsigned long),
9263 if (!event
->addr_filters_offs
)
9266 /* force hw sync on the address filters */
9267 event
->addr_filters_gen
= 1;
9270 if (!event
->parent
) {
9271 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9272 err
= get_callchain_buffers(attr
->sample_max_stack
);
9274 goto err_addr_filters
;
9278 /* symmetric to unaccount_event() in _free_event() */
9279 account_event(event
);
9284 kfree(event
->addr_filters_offs
);
9287 exclusive_event_destroy(event
);
9291 event
->destroy(event
);
9292 module_put(pmu
->module
);
9294 if (is_cgroup_event(event
))
9295 perf_detach_cgroup(event
);
9297 put_pid_ns(event
->ns
);
9300 return ERR_PTR(err
);
9303 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9304 struct perf_event_attr
*attr
)
9309 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9313 * zero the full structure, so that a short copy will be nice.
9315 memset(attr
, 0, sizeof(*attr
));
9317 ret
= get_user(size
, &uattr
->size
);
9321 if (size
> PAGE_SIZE
) /* silly large */
9324 if (!size
) /* abi compat */
9325 size
= PERF_ATTR_SIZE_VER0
;
9327 if (size
< PERF_ATTR_SIZE_VER0
)
9331 * If we're handed a bigger struct than we know of,
9332 * ensure all the unknown bits are 0 - i.e. new
9333 * user-space does not rely on any kernel feature
9334 * extensions we dont know about yet.
9336 if (size
> sizeof(*attr
)) {
9337 unsigned char __user
*addr
;
9338 unsigned char __user
*end
;
9341 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9342 end
= (void __user
*)uattr
+ size
;
9344 for (; addr
< end
; addr
++) {
9345 ret
= get_user(val
, addr
);
9351 size
= sizeof(*attr
);
9354 ret
= copy_from_user(attr
, uattr
, size
);
9358 if (attr
->__reserved_1
)
9361 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9364 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9367 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9368 u64 mask
= attr
->branch_sample_type
;
9370 /* only using defined bits */
9371 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9374 /* at least one branch bit must be set */
9375 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9378 /* propagate priv level, when not set for branch */
9379 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9381 /* exclude_kernel checked on syscall entry */
9382 if (!attr
->exclude_kernel
)
9383 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9385 if (!attr
->exclude_user
)
9386 mask
|= PERF_SAMPLE_BRANCH_USER
;
9388 if (!attr
->exclude_hv
)
9389 mask
|= PERF_SAMPLE_BRANCH_HV
;
9391 * adjust user setting (for HW filter setup)
9393 attr
->branch_sample_type
= mask
;
9395 /* privileged levels capture (kernel, hv): check permissions */
9396 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9397 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9401 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9402 ret
= perf_reg_validate(attr
->sample_regs_user
);
9407 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9408 if (!arch_perf_have_user_stack_dump())
9412 * We have __u32 type for the size, but so far
9413 * we can only use __u16 as maximum due to the
9414 * __u16 sample size limit.
9416 if (attr
->sample_stack_user
>= USHRT_MAX
)
9418 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9422 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9423 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9428 put_user(sizeof(*attr
), &uattr
->size
);
9434 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9436 struct ring_buffer
*rb
= NULL
;
9442 /* don't allow circular references */
9443 if (event
== output_event
)
9447 * Don't allow cross-cpu buffers
9449 if (output_event
->cpu
!= event
->cpu
)
9453 * If its not a per-cpu rb, it must be the same task.
9455 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9459 * Mixing clocks in the same buffer is trouble you don't need.
9461 if (output_event
->clock
!= event
->clock
)
9465 * Either writing ring buffer from beginning or from end.
9466 * Mixing is not allowed.
9468 if (is_write_backward(output_event
) != is_write_backward(event
))
9472 * If both events generate aux data, they must be on the same PMU
9474 if (has_aux(event
) && has_aux(output_event
) &&
9475 event
->pmu
!= output_event
->pmu
)
9479 mutex_lock(&event
->mmap_mutex
);
9480 /* Can't redirect output if we've got an active mmap() */
9481 if (atomic_read(&event
->mmap_count
))
9485 /* get the rb we want to redirect to */
9486 rb
= ring_buffer_get(output_event
);
9491 ring_buffer_attach(event
, rb
);
9495 mutex_unlock(&event
->mmap_mutex
);
9501 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9507 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9510 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9512 bool nmi_safe
= false;
9515 case CLOCK_MONOTONIC
:
9516 event
->clock
= &ktime_get_mono_fast_ns
;
9520 case CLOCK_MONOTONIC_RAW
:
9521 event
->clock
= &ktime_get_raw_fast_ns
;
9525 case CLOCK_REALTIME
:
9526 event
->clock
= &ktime_get_real_ns
;
9529 case CLOCK_BOOTTIME
:
9530 event
->clock
= &ktime_get_boot_ns
;
9534 event
->clock
= &ktime_get_tai_ns
;
9541 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9548 * Variation on perf_event_ctx_lock_nested(), except we take two context
9551 static struct perf_event_context
*
9552 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9553 struct perf_event_context
*ctx
)
9555 struct perf_event_context
*gctx
;
9559 gctx
= READ_ONCE(group_leader
->ctx
);
9560 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9566 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9568 if (group_leader
->ctx
!= gctx
) {
9569 mutex_unlock(&ctx
->mutex
);
9570 mutex_unlock(&gctx
->mutex
);
9579 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9581 * @attr_uptr: event_id type attributes for monitoring/sampling
9584 * @group_fd: group leader event fd
9586 SYSCALL_DEFINE5(perf_event_open
,
9587 struct perf_event_attr __user
*, attr_uptr
,
9588 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9590 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9591 struct perf_event
*event
, *sibling
;
9592 struct perf_event_attr attr
;
9593 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9594 struct file
*event_file
= NULL
;
9595 struct fd group
= {NULL
, 0};
9596 struct task_struct
*task
= NULL
;
9601 int f_flags
= O_RDWR
;
9604 /* for future expandability... */
9605 if (flags
& ~PERF_FLAG_ALL
)
9608 err
= perf_copy_attr(attr_uptr
, &attr
);
9612 if (!attr
.exclude_kernel
) {
9613 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9618 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9621 if (attr
.sample_period
& (1ULL << 63))
9625 if (!attr
.sample_max_stack
)
9626 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9629 * In cgroup mode, the pid argument is used to pass the fd
9630 * opened to the cgroup directory in cgroupfs. The cpu argument
9631 * designates the cpu on which to monitor threads from that
9634 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9637 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9638 f_flags
|= O_CLOEXEC
;
9640 event_fd
= get_unused_fd_flags(f_flags
);
9644 if (group_fd
!= -1) {
9645 err
= perf_fget_light(group_fd
, &group
);
9648 group_leader
= group
.file
->private_data
;
9649 if (flags
& PERF_FLAG_FD_OUTPUT
)
9650 output_event
= group_leader
;
9651 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9652 group_leader
= NULL
;
9655 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9656 task
= find_lively_task_by_vpid(pid
);
9658 err
= PTR_ERR(task
);
9663 if (task
&& group_leader
&&
9664 group_leader
->attr
.inherit
!= attr
.inherit
) {
9672 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
9677 * Reuse ptrace permission checks for now.
9679 * We must hold cred_guard_mutex across this and any potential
9680 * perf_install_in_context() call for this new event to
9681 * serialize against exec() altering our credentials (and the
9682 * perf_event_exit_task() that could imply).
9685 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
9689 if (flags
& PERF_FLAG_PID_CGROUP
)
9692 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
9693 NULL
, NULL
, cgroup_fd
);
9694 if (IS_ERR(event
)) {
9695 err
= PTR_ERR(event
);
9699 if (is_sampling_event(event
)) {
9700 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
9707 * Special case software events and allow them to be part of
9708 * any hardware group.
9712 if (attr
.use_clockid
) {
9713 err
= perf_event_set_clock(event
, attr
.clockid
);
9718 if (pmu
->task_ctx_nr
== perf_sw_context
)
9719 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
9722 (is_software_event(event
) != is_software_event(group_leader
))) {
9723 if (is_software_event(event
)) {
9725 * If event and group_leader are not both a software
9726 * event, and event is, then group leader is not.
9728 * Allow the addition of software events to !software
9729 * groups, this is safe because software events never
9732 pmu
= group_leader
->pmu
;
9733 } else if (is_software_event(group_leader
) &&
9734 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
9736 * In case the group is a pure software group, and we
9737 * try to add a hardware event, move the whole group to
9738 * the hardware context.
9745 * Get the target context (task or percpu):
9747 ctx
= find_get_context(pmu
, task
, event
);
9753 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
9759 * Look up the group leader (we will attach this event to it):
9765 * Do not allow a recursive hierarchy (this new sibling
9766 * becoming part of another group-sibling):
9768 if (group_leader
->group_leader
!= group_leader
)
9771 /* All events in a group should have the same clock */
9772 if (group_leader
->clock
!= event
->clock
)
9776 * Do not allow to attach to a group in a different
9777 * task or CPU context:
9781 * Make sure we're both on the same task, or both
9784 if (group_leader
->ctx
->task
!= ctx
->task
)
9788 * Make sure we're both events for the same CPU;
9789 * grouping events for different CPUs is broken; since
9790 * you can never concurrently schedule them anyhow.
9792 if (group_leader
->cpu
!= event
->cpu
)
9795 if (group_leader
->ctx
!= ctx
)
9800 * Only a group leader can be exclusive or pinned
9802 if (attr
.exclusive
|| attr
.pinned
)
9807 err
= perf_event_set_output(event
, output_event
);
9812 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
9814 if (IS_ERR(event_file
)) {
9815 err
= PTR_ERR(event_file
);
9821 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
9823 if (gctx
->task
== TASK_TOMBSTONE
) {
9829 * Check if we raced against another sys_perf_event_open() call
9830 * moving the software group underneath us.
9832 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
9834 * If someone moved the group out from under us, check
9835 * if this new event wound up on the same ctx, if so
9836 * its the regular !move_group case, otherwise fail.
9842 perf_event_ctx_unlock(group_leader
, gctx
);
9847 mutex_lock(&ctx
->mutex
);
9850 if (ctx
->task
== TASK_TOMBSTONE
) {
9855 if (!perf_event_validate_size(event
)) {
9861 * Must be under the same ctx::mutex as perf_install_in_context(),
9862 * because we need to serialize with concurrent event creation.
9864 if (!exclusive_event_installable(event
, ctx
)) {
9865 /* exclusive and group stuff are assumed mutually exclusive */
9866 WARN_ON_ONCE(move_group
);
9872 WARN_ON_ONCE(ctx
->parent_ctx
);
9875 * This is the point on no return; we cannot fail hereafter. This is
9876 * where we start modifying current state.
9881 * See perf_event_ctx_lock() for comments on the details
9882 * of swizzling perf_event::ctx.
9884 perf_remove_from_context(group_leader
, 0);
9886 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
9888 perf_remove_from_context(sibling
, 0);
9893 * Wait for everybody to stop referencing the events through
9894 * the old lists, before installing it on new lists.
9899 * Install the group siblings before the group leader.
9901 * Because a group leader will try and install the entire group
9902 * (through the sibling list, which is still in-tact), we can
9903 * end up with siblings installed in the wrong context.
9905 * By installing siblings first we NO-OP because they're not
9906 * reachable through the group lists.
9908 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
9910 perf_event__state_init(sibling
);
9911 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
9916 * Removing from the context ends up with disabled
9917 * event. What we want here is event in the initial
9918 * startup state, ready to be add into new context.
9920 perf_event__state_init(group_leader
);
9921 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
9925 * Now that all events are installed in @ctx, nothing
9926 * references @gctx anymore, so drop the last reference we have
9933 * Precalculate sample_data sizes; do while holding ctx::mutex such
9934 * that we're serialized against further additions and before
9935 * perf_install_in_context() which is the point the event is active and
9936 * can use these values.
9938 perf_event__header_size(event
);
9939 perf_event__id_header_size(event
);
9941 event
->owner
= current
;
9943 perf_install_in_context(ctx
, event
, event
->cpu
);
9944 perf_unpin_context(ctx
);
9947 perf_event_ctx_unlock(group_leader
, gctx
);
9948 mutex_unlock(&ctx
->mutex
);
9951 mutex_unlock(&task
->signal
->cred_guard_mutex
);
9952 put_task_struct(task
);
9957 mutex_lock(¤t
->perf_event_mutex
);
9958 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
9959 mutex_unlock(¤t
->perf_event_mutex
);
9962 * Drop the reference on the group_event after placing the
9963 * new event on the sibling_list. This ensures destruction
9964 * of the group leader will find the pointer to itself in
9965 * perf_group_detach().
9968 fd_install(event_fd
, event_file
);
9973 perf_event_ctx_unlock(group_leader
, gctx
);
9974 mutex_unlock(&ctx
->mutex
);
9978 perf_unpin_context(ctx
);
9982 * If event_file is set, the fput() above will have called ->release()
9983 * and that will take care of freeing the event.
9989 mutex_unlock(&task
->signal
->cred_guard_mutex
);
9994 put_task_struct(task
);
9998 put_unused_fd(event_fd
);
10003 * perf_event_create_kernel_counter
10005 * @attr: attributes of the counter to create
10006 * @cpu: cpu in which the counter is bound
10007 * @task: task to profile (NULL for percpu)
10009 struct perf_event
*
10010 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10011 struct task_struct
*task
,
10012 perf_overflow_handler_t overflow_handler
,
10015 struct perf_event_context
*ctx
;
10016 struct perf_event
*event
;
10020 * Get the target context (task or percpu):
10023 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10024 overflow_handler
, context
, -1);
10025 if (IS_ERR(event
)) {
10026 err
= PTR_ERR(event
);
10030 /* Mark owner so we could distinguish it from user events. */
10031 event
->owner
= TASK_TOMBSTONE
;
10033 ctx
= find_get_context(event
->pmu
, task
, event
);
10035 err
= PTR_ERR(ctx
);
10039 WARN_ON_ONCE(ctx
->parent_ctx
);
10040 mutex_lock(&ctx
->mutex
);
10041 if (ctx
->task
== TASK_TOMBSTONE
) {
10046 if (!exclusive_event_installable(event
, ctx
)) {
10051 perf_install_in_context(ctx
, event
, cpu
);
10052 perf_unpin_context(ctx
);
10053 mutex_unlock(&ctx
->mutex
);
10058 mutex_unlock(&ctx
->mutex
);
10059 perf_unpin_context(ctx
);
10064 return ERR_PTR(err
);
10066 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10068 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10070 struct perf_event_context
*src_ctx
;
10071 struct perf_event_context
*dst_ctx
;
10072 struct perf_event
*event
, *tmp
;
10075 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10076 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10079 * See perf_event_ctx_lock() for comments on the details
10080 * of swizzling perf_event::ctx.
10082 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10083 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10085 perf_remove_from_context(event
, 0);
10086 unaccount_event_cpu(event
, src_cpu
);
10088 list_add(&event
->migrate_entry
, &events
);
10092 * Wait for the events to quiesce before re-instating them.
10097 * Re-instate events in 2 passes.
10099 * Skip over group leaders and only install siblings on this first
10100 * pass, siblings will not get enabled without a leader, however a
10101 * leader will enable its siblings, even if those are still on the old
10104 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10105 if (event
->group_leader
== event
)
10108 list_del(&event
->migrate_entry
);
10109 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10110 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10111 account_event_cpu(event
, dst_cpu
);
10112 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10117 * Once all the siblings are setup properly, install the group leaders
10120 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10121 list_del(&event
->migrate_entry
);
10122 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10123 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10124 account_event_cpu(event
, dst_cpu
);
10125 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10128 mutex_unlock(&dst_ctx
->mutex
);
10129 mutex_unlock(&src_ctx
->mutex
);
10131 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10133 static void sync_child_event(struct perf_event
*child_event
,
10134 struct task_struct
*child
)
10136 struct perf_event
*parent_event
= child_event
->parent
;
10139 if (child_event
->attr
.inherit_stat
)
10140 perf_event_read_event(child_event
, child
);
10142 child_val
= perf_event_count(child_event
);
10145 * Add back the child's count to the parent's count:
10147 atomic64_add(child_val
, &parent_event
->child_count
);
10148 atomic64_add(child_event
->total_time_enabled
,
10149 &parent_event
->child_total_time_enabled
);
10150 atomic64_add(child_event
->total_time_running
,
10151 &parent_event
->child_total_time_running
);
10155 perf_event_exit_event(struct perf_event
*child_event
,
10156 struct perf_event_context
*child_ctx
,
10157 struct task_struct
*child
)
10159 struct perf_event
*parent_event
= child_event
->parent
;
10162 * Do not destroy the 'original' grouping; because of the context
10163 * switch optimization the original events could've ended up in a
10164 * random child task.
10166 * If we were to destroy the original group, all group related
10167 * operations would cease to function properly after this random
10170 * Do destroy all inherited groups, we don't care about those
10171 * and being thorough is better.
10173 raw_spin_lock_irq(&child_ctx
->lock
);
10174 WARN_ON_ONCE(child_ctx
->is_active
);
10177 perf_group_detach(child_event
);
10178 list_del_event(child_event
, child_ctx
);
10179 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
10180 raw_spin_unlock_irq(&child_ctx
->lock
);
10183 * Parent events are governed by their filedesc, retain them.
10185 if (!parent_event
) {
10186 perf_event_wakeup(child_event
);
10190 * Child events can be cleaned up.
10193 sync_child_event(child_event
, child
);
10196 * Remove this event from the parent's list
10198 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10199 mutex_lock(&parent_event
->child_mutex
);
10200 list_del_init(&child_event
->child_list
);
10201 mutex_unlock(&parent_event
->child_mutex
);
10204 * Kick perf_poll() for is_event_hup().
10206 perf_event_wakeup(parent_event
);
10207 free_event(child_event
);
10208 put_event(parent_event
);
10211 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10213 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10214 struct perf_event
*child_event
, *next
;
10216 WARN_ON_ONCE(child
!= current
);
10218 child_ctx
= perf_pin_task_context(child
, ctxn
);
10223 * In order to reduce the amount of tricky in ctx tear-down, we hold
10224 * ctx::mutex over the entire thing. This serializes against almost
10225 * everything that wants to access the ctx.
10227 * The exception is sys_perf_event_open() /
10228 * perf_event_create_kernel_count() which does find_get_context()
10229 * without ctx::mutex (it cannot because of the move_group double mutex
10230 * lock thing). See the comments in perf_install_in_context().
10232 mutex_lock(&child_ctx
->mutex
);
10235 * In a single ctx::lock section, de-schedule the events and detach the
10236 * context from the task such that we cannot ever get it scheduled back
10239 raw_spin_lock_irq(&child_ctx
->lock
);
10240 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
);
10243 * Now that the context is inactive, destroy the task <-> ctx relation
10244 * and mark the context dead.
10246 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10247 put_ctx(child_ctx
); /* cannot be last */
10248 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10249 put_task_struct(current
); /* cannot be last */
10251 clone_ctx
= unclone_ctx(child_ctx
);
10252 raw_spin_unlock_irq(&child_ctx
->lock
);
10255 put_ctx(clone_ctx
);
10258 * Report the task dead after unscheduling the events so that we
10259 * won't get any samples after PERF_RECORD_EXIT. We can however still
10260 * get a few PERF_RECORD_READ events.
10262 perf_event_task(child
, child_ctx
, 0);
10264 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10265 perf_event_exit_event(child_event
, child_ctx
, child
);
10267 mutex_unlock(&child_ctx
->mutex
);
10269 put_ctx(child_ctx
);
10273 * When a child task exits, feed back event values to parent events.
10275 * Can be called with cred_guard_mutex held when called from
10276 * install_exec_creds().
10278 void perf_event_exit_task(struct task_struct
*child
)
10280 struct perf_event
*event
, *tmp
;
10283 mutex_lock(&child
->perf_event_mutex
);
10284 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10286 list_del_init(&event
->owner_entry
);
10289 * Ensure the list deletion is visible before we clear
10290 * the owner, closes a race against perf_release() where
10291 * we need to serialize on the owner->perf_event_mutex.
10293 smp_store_release(&event
->owner
, NULL
);
10295 mutex_unlock(&child
->perf_event_mutex
);
10297 for_each_task_context_nr(ctxn
)
10298 perf_event_exit_task_context(child
, ctxn
);
10301 * The perf_event_exit_task_context calls perf_event_task
10302 * with child's task_ctx, which generates EXIT events for
10303 * child contexts and sets child->perf_event_ctxp[] to NULL.
10304 * At this point we need to send EXIT events to cpu contexts.
10306 perf_event_task(child
, NULL
, 0);
10309 static void perf_free_event(struct perf_event
*event
,
10310 struct perf_event_context
*ctx
)
10312 struct perf_event
*parent
= event
->parent
;
10314 if (WARN_ON_ONCE(!parent
))
10317 mutex_lock(&parent
->child_mutex
);
10318 list_del_init(&event
->child_list
);
10319 mutex_unlock(&parent
->child_mutex
);
10323 raw_spin_lock_irq(&ctx
->lock
);
10324 perf_group_detach(event
);
10325 list_del_event(event
, ctx
);
10326 raw_spin_unlock_irq(&ctx
->lock
);
10331 * Free an unexposed, unused context as created by inheritance by
10332 * perf_event_init_task below, used by fork() in case of fail.
10334 * Not all locks are strictly required, but take them anyway to be nice and
10335 * help out with the lockdep assertions.
10337 void perf_event_free_task(struct task_struct
*task
)
10339 struct perf_event_context
*ctx
;
10340 struct perf_event
*event
, *tmp
;
10343 for_each_task_context_nr(ctxn
) {
10344 ctx
= task
->perf_event_ctxp
[ctxn
];
10348 mutex_lock(&ctx
->mutex
);
10350 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
10352 perf_free_event(event
, ctx
);
10354 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
10356 perf_free_event(event
, ctx
);
10358 if (!list_empty(&ctx
->pinned_groups
) ||
10359 !list_empty(&ctx
->flexible_groups
))
10362 mutex_unlock(&ctx
->mutex
);
10368 void perf_event_delayed_put(struct task_struct
*task
)
10372 for_each_task_context_nr(ctxn
)
10373 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10376 struct file
*perf_event_get(unsigned int fd
)
10380 file
= fget_raw(fd
);
10382 return ERR_PTR(-EBADF
);
10384 if (file
->f_op
!= &perf_fops
) {
10386 return ERR_PTR(-EBADF
);
10392 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10395 return ERR_PTR(-EINVAL
);
10397 return &event
->attr
;
10401 * inherit a event from parent task to child task:
10403 static struct perf_event
*
10404 inherit_event(struct perf_event
*parent_event
,
10405 struct task_struct
*parent
,
10406 struct perf_event_context
*parent_ctx
,
10407 struct task_struct
*child
,
10408 struct perf_event
*group_leader
,
10409 struct perf_event_context
*child_ctx
)
10411 enum perf_event_active_state parent_state
= parent_event
->state
;
10412 struct perf_event
*child_event
;
10413 unsigned long flags
;
10416 * Instead of creating recursive hierarchies of events,
10417 * we link inherited events back to the original parent,
10418 * which has a filp for sure, which we use as the reference
10421 if (parent_event
->parent
)
10422 parent_event
= parent_event
->parent
;
10424 child_event
= perf_event_alloc(&parent_event
->attr
,
10427 group_leader
, parent_event
,
10429 if (IS_ERR(child_event
))
10430 return child_event
;
10433 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10434 * must be under the same lock in order to serialize against
10435 * perf_event_release_kernel(), such that either we must observe
10436 * is_orphaned_event() or they will observe us on the child_list.
10438 mutex_lock(&parent_event
->child_mutex
);
10439 if (is_orphaned_event(parent_event
) ||
10440 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10441 mutex_unlock(&parent_event
->child_mutex
);
10442 free_event(child_event
);
10446 get_ctx(child_ctx
);
10449 * Make the child state follow the state of the parent event,
10450 * not its attr.disabled bit. We hold the parent's mutex,
10451 * so we won't race with perf_event_{en, dis}able_family.
10453 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10454 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10456 child_event
->state
= PERF_EVENT_STATE_OFF
;
10458 if (parent_event
->attr
.freq
) {
10459 u64 sample_period
= parent_event
->hw
.sample_period
;
10460 struct hw_perf_event
*hwc
= &child_event
->hw
;
10462 hwc
->sample_period
= sample_period
;
10463 hwc
->last_period
= sample_period
;
10465 local64_set(&hwc
->period_left
, sample_period
);
10468 child_event
->ctx
= child_ctx
;
10469 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10470 child_event
->overflow_handler_context
10471 = parent_event
->overflow_handler_context
;
10474 * Precalculate sample_data sizes
10476 perf_event__header_size(child_event
);
10477 perf_event__id_header_size(child_event
);
10480 * Link it up in the child's context:
10482 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10483 add_event_to_ctx(child_event
, child_ctx
);
10484 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10487 * Link this into the parent event's child list
10489 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10490 mutex_unlock(&parent_event
->child_mutex
);
10492 return child_event
;
10495 static int inherit_group(struct perf_event
*parent_event
,
10496 struct task_struct
*parent
,
10497 struct perf_event_context
*parent_ctx
,
10498 struct task_struct
*child
,
10499 struct perf_event_context
*child_ctx
)
10501 struct perf_event
*leader
;
10502 struct perf_event
*sub
;
10503 struct perf_event
*child_ctr
;
10505 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10506 child
, NULL
, child_ctx
);
10507 if (IS_ERR(leader
))
10508 return PTR_ERR(leader
);
10509 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10510 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10511 child
, leader
, child_ctx
);
10512 if (IS_ERR(child_ctr
))
10513 return PTR_ERR(child_ctr
);
10519 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10520 struct perf_event_context
*parent_ctx
,
10521 struct task_struct
*child
, int ctxn
,
10522 int *inherited_all
)
10525 struct perf_event_context
*child_ctx
;
10527 if (!event
->attr
.inherit
) {
10528 *inherited_all
= 0;
10532 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10535 * This is executed from the parent task context, so
10536 * inherit events that have been marked for cloning.
10537 * First allocate and initialize a context for the
10541 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10545 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10548 ret
= inherit_group(event
, parent
, parent_ctx
,
10552 *inherited_all
= 0;
10558 * Initialize the perf_event context in task_struct
10560 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10562 struct perf_event_context
*child_ctx
, *parent_ctx
;
10563 struct perf_event_context
*cloned_ctx
;
10564 struct perf_event
*event
;
10565 struct task_struct
*parent
= current
;
10566 int inherited_all
= 1;
10567 unsigned long flags
;
10570 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10574 * If the parent's context is a clone, pin it so it won't get
10575 * swapped under us.
10577 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10582 * No need to check if parent_ctx != NULL here; since we saw
10583 * it non-NULL earlier, the only reason for it to become NULL
10584 * is if we exit, and since we're currently in the middle of
10585 * a fork we can't be exiting at the same time.
10589 * Lock the parent list. No need to lock the child - not PID
10590 * hashed yet and not running, so nobody can access it.
10592 mutex_lock(&parent_ctx
->mutex
);
10595 * We dont have to disable NMIs - we are only looking at
10596 * the list, not manipulating it:
10598 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10599 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10600 child
, ctxn
, &inherited_all
);
10606 * We can't hold ctx->lock when iterating the ->flexible_group list due
10607 * to allocations, but we need to prevent rotation because
10608 * rotate_ctx() will change the list from interrupt context.
10610 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10611 parent_ctx
->rotate_disable
= 1;
10612 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10614 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10615 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10616 child
, ctxn
, &inherited_all
);
10621 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10622 parent_ctx
->rotate_disable
= 0;
10624 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10626 if (child_ctx
&& inherited_all
) {
10628 * Mark the child context as a clone of the parent
10629 * context, or of whatever the parent is a clone of.
10631 * Note that if the parent is a clone, the holding of
10632 * parent_ctx->lock avoids it from being uncloned.
10634 cloned_ctx
= parent_ctx
->parent_ctx
;
10636 child_ctx
->parent_ctx
= cloned_ctx
;
10637 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
10639 child_ctx
->parent_ctx
= parent_ctx
;
10640 child_ctx
->parent_gen
= parent_ctx
->generation
;
10642 get_ctx(child_ctx
->parent_ctx
);
10645 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10646 mutex_unlock(&parent_ctx
->mutex
);
10648 perf_unpin_context(parent_ctx
);
10649 put_ctx(parent_ctx
);
10655 * Initialize the perf_event context in task_struct
10657 int perf_event_init_task(struct task_struct
*child
)
10661 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
10662 mutex_init(&child
->perf_event_mutex
);
10663 INIT_LIST_HEAD(&child
->perf_event_list
);
10665 for_each_task_context_nr(ctxn
) {
10666 ret
= perf_event_init_context(child
, ctxn
);
10668 perf_event_free_task(child
);
10676 static void __init
perf_event_init_all_cpus(void)
10678 struct swevent_htable
*swhash
;
10681 for_each_possible_cpu(cpu
) {
10682 swhash
= &per_cpu(swevent_htable
, cpu
);
10683 mutex_init(&swhash
->hlist_mutex
);
10684 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
10686 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
10687 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
10689 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
10693 int perf_event_init_cpu(unsigned int cpu
)
10695 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
10697 mutex_lock(&swhash
->hlist_mutex
);
10698 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
10699 struct swevent_hlist
*hlist
;
10701 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
10703 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
10705 mutex_unlock(&swhash
->hlist_mutex
);
10709 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
10710 static void __perf_event_exit_context(void *__info
)
10712 struct perf_event_context
*ctx
= __info
;
10713 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
10714 struct perf_event
*event
;
10716 raw_spin_lock(&ctx
->lock
);
10717 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
10718 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
10719 raw_spin_unlock(&ctx
->lock
);
10722 static void perf_event_exit_cpu_context(int cpu
)
10724 struct perf_event_context
*ctx
;
10728 idx
= srcu_read_lock(&pmus_srcu
);
10729 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
10730 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
10732 mutex_lock(&ctx
->mutex
);
10733 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
10734 mutex_unlock(&ctx
->mutex
);
10736 srcu_read_unlock(&pmus_srcu
, idx
);
10740 static void perf_event_exit_cpu_context(int cpu
) { }
10744 int perf_event_exit_cpu(unsigned int cpu
)
10746 perf_event_exit_cpu_context(cpu
);
10751 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
10755 for_each_online_cpu(cpu
)
10756 perf_event_exit_cpu(cpu
);
10762 * Run the perf reboot notifier at the very last possible moment so that
10763 * the generic watchdog code runs as long as possible.
10765 static struct notifier_block perf_reboot_notifier
= {
10766 .notifier_call
= perf_reboot
,
10767 .priority
= INT_MIN
,
10770 void __init
perf_event_init(void)
10774 idr_init(&pmu_idr
);
10776 perf_event_init_all_cpus();
10777 init_srcu_struct(&pmus_srcu
);
10778 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
10779 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
10780 perf_pmu_register(&perf_task_clock
, NULL
, -1);
10781 perf_tp_register();
10782 perf_event_init_cpu(smp_processor_id());
10783 register_reboot_notifier(&perf_reboot_notifier
);
10785 ret
= init_hw_breakpoint();
10786 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
10789 * Build time assertion that we keep the data_head at the intended
10790 * location. IOW, validation we got the __reserved[] size right.
10792 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
10796 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
10799 struct perf_pmu_events_attr
*pmu_attr
=
10800 container_of(attr
, struct perf_pmu_events_attr
, attr
);
10802 if (pmu_attr
->event_str
)
10803 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
10807 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
10809 static int __init
perf_event_sysfs_init(void)
10814 mutex_lock(&pmus_lock
);
10816 ret
= bus_register(&pmu_bus
);
10820 list_for_each_entry(pmu
, &pmus
, entry
) {
10821 if (!pmu
->name
|| pmu
->type
< 0)
10824 ret
= pmu_dev_alloc(pmu
);
10825 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
10827 pmu_bus_running
= 1;
10831 mutex_unlock(&pmus_lock
);
10835 device_initcall(perf_event_sysfs_init
);
10837 #ifdef CONFIG_CGROUP_PERF
10838 static struct cgroup_subsys_state
*
10839 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
10841 struct perf_cgroup
*jc
;
10843 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
10845 return ERR_PTR(-ENOMEM
);
10847 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
10850 return ERR_PTR(-ENOMEM
);
10856 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
10858 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
10860 free_percpu(jc
->info
);
10864 static int __perf_cgroup_move(void *info
)
10866 struct task_struct
*task
= info
;
10868 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
10873 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
10875 struct task_struct
*task
;
10876 struct cgroup_subsys_state
*css
;
10878 cgroup_taskset_for_each(task
, css
, tset
)
10879 task_function_call(task
, __perf_cgroup_move
, task
);
10882 struct cgroup_subsys perf_event_cgrp_subsys
= {
10883 .css_alloc
= perf_cgroup_css_alloc
,
10884 .css_free
= perf_cgroup_css_free
,
10885 .attach
= perf_cgroup_attach
,
10887 #endif /* CONFIG_CGROUP_PERF */