2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
49 #include <linux/sched/clock.h>
50 #include <linux/sched/mm.h>
51 #include <linux/proc_ns.h>
52 #include <linux/mount.h>
56 #include <asm/irq_regs.h>
58 typedef int (*remote_function_f
)(void *);
60 struct remote_function_call
{
61 struct task_struct
*p
;
62 remote_function_f func
;
67 static void remote_function(void *data
)
69 struct remote_function_call
*tfc
= data
;
70 struct task_struct
*p
= tfc
->p
;
74 if (task_cpu(p
) != smp_processor_id())
78 * Now that we're on right CPU with IRQs disabled, we can test
79 * if we hit the right task without races.
82 tfc
->ret
= -ESRCH
; /* No such (running) process */
87 tfc
->ret
= tfc
->func(tfc
->info
);
91 * task_function_call - call a function on the cpu on which a task runs
92 * @p: the task to evaluate
93 * @func: the function to be called
94 * @info: the function call argument
96 * Calls the function @func when the task is currently running. This might
97 * be on the current CPU, which just calls the function directly
99 * returns: @func return value, or
100 * -ESRCH - when the process isn't running
101 * -EAGAIN - when the process moved away
104 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
106 struct remote_function_call data
= {
115 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
118 } while (ret
== -EAGAIN
);
124 * cpu_function_call - call a function on the cpu
125 * @func: the function to be called
126 * @info: the function call argument
128 * Calls the function @func on the remote cpu.
130 * returns: @func return value or -ENXIO when the cpu is offline
132 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
134 struct remote_function_call data
= {
138 .ret
= -ENXIO
, /* No such CPU */
141 smp_call_function_single(cpu
, remote_function
, &data
, 1);
146 static inline struct perf_cpu_context
*
147 __get_cpu_context(struct perf_event_context
*ctx
)
149 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
152 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
153 struct perf_event_context
*ctx
)
155 raw_spin_lock(&cpuctx
->ctx
.lock
);
157 raw_spin_lock(&ctx
->lock
);
160 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
161 struct perf_event_context
*ctx
)
164 raw_spin_unlock(&ctx
->lock
);
165 raw_spin_unlock(&cpuctx
->ctx
.lock
);
168 #define TASK_TOMBSTONE ((void *)-1L)
170 static bool is_kernel_event(struct perf_event
*event
)
172 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
176 * On task ctx scheduling...
178 * When !ctx->nr_events a task context will not be scheduled. This means
179 * we can disable the scheduler hooks (for performance) without leaving
180 * pending task ctx state.
182 * This however results in two special cases:
184 * - removing the last event from a task ctx; this is relatively straight
185 * forward and is done in __perf_remove_from_context.
187 * - adding the first event to a task ctx; this is tricky because we cannot
188 * rely on ctx->is_active and therefore cannot use event_function_call().
189 * See perf_install_in_context().
191 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
194 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
195 struct perf_event_context
*, void *);
197 struct event_function_struct
{
198 struct perf_event
*event
;
203 static int event_function(void *info
)
205 struct event_function_struct
*efs
= info
;
206 struct perf_event
*event
= efs
->event
;
207 struct perf_event_context
*ctx
= event
->ctx
;
208 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
209 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
212 WARN_ON_ONCE(!irqs_disabled());
214 perf_ctx_lock(cpuctx
, task_ctx
);
216 * Since we do the IPI call without holding ctx->lock things can have
217 * changed, double check we hit the task we set out to hit.
220 if (ctx
->task
!= current
) {
226 * We only use event_function_call() on established contexts,
227 * and event_function() is only ever called when active (or
228 * rather, we'll have bailed in task_function_call() or the
229 * above ctx->task != current test), therefore we must have
230 * ctx->is_active here.
232 WARN_ON_ONCE(!ctx
->is_active
);
234 * And since we have ctx->is_active, cpuctx->task_ctx must
237 WARN_ON_ONCE(task_ctx
!= ctx
);
239 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
242 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
244 perf_ctx_unlock(cpuctx
, task_ctx
);
249 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
251 struct perf_event_context
*ctx
= event
->ctx
;
252 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
253 struct event_function_struct efs
= {
259 if (!event
->parent
) {
261 * If this is a !child event, we must hold ctx::mutex to
262 * stabilize the the event->ctx relation. See
263 * perf_event_ctx_lock().
265 lockdep_assert_held(&ctx
->mutex
);
269 cpu_function_call(event
->cpu
, event_function
, &efs
);
273 if (task
== TASK_TOMBSTONE
)
277 if (!task_function_call(task
, event_function
, &efs
))
280 raw_spin_lock_irq(&ctx
->lock
);
282 * Reload the task pointer, it might have been changed by
283 * a concurrent perf_event_context_sched_out().
286 if (task
== TASK_TOMBSTONE
) {
287 raw_spin_unlock_irq(&ctx
->lock
);
290 if (ctx
->is_active
) {
291 raw_spin_unlock_irq(&ctx
->lock
);
294 func(event
, NULL
, ctx
, data
);
295 raw_spin_unlock_irq(&ctx
->lock
);
299 * Similar to event_function_call() + event_function(), but hard assumes IRQs
300 * are already disabled and we're on the right CPU.
302 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
304 struct perf_event_context
*ctx
= event
->ctx
;
305 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
306 struct task_struct
*task
= READ_ONCE(ctx
->task
);
307 struct perf_event_context
*task_ctx
= NULL
;
309 WARN_ON_ONCE(!irqs_disabled());
312 if (task
== TASK_TOMBSTONE
)
318 perf_ctx_lock(cpuctx
, task_ctx
);
321 if (task
== TASK_TOMBSTONE
)
326 * We must be either inactive or active and the right task,
327 * otherwise we're screwed, since we cannot IPI to somewhere
330 if (ctx
->is_active
) {
331 if (WARN_ON_ONCE(task
!= current
))
334 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
338 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
341 func(event
, cpuctx
, ctx
, data
);
343 perf_ctx_unlock(cpuctx
, task_ctx
);
346 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
347 PERF_FLAG_FD_OUTPUT |\
348 PERF_FLAG_PID_CGROUP |\
349 PERF_FLAG_FD_CLOEXEC)
352 * branch priv levels that need permission checks
354 #define PERF_SAMPLE_BRANCH_PERM_PLM \
355 (PERF_SAMPLE_BRANCH_KERNEL |\
356 PERF_SAMPLE_BRANCH_HV)
359 EVENT_FLEXIBLE
= 0x1,
362 /* see ctx_resched() for details */
364 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
368 * perf_sched_events : >0 events exist
369 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
372 static void perf_sched_delayed(struct work_struct
*work
);
373 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
374 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
375 static DEFINE_MUTEX(perf_sched_mutex
);
376 static atomic_t perf_sched_count
;
378 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
379 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
380 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
382 static atomic_t nr_mmap_events __read_mostly
;
383 static atomic_t nr_comm_events __read_mostly
;
384 static atomic_t nr_namespaces_events __read_mostly
;
385 static atomic_t nr_task_events __read_mostly
;
386 static atomic_t nr_freq_events __read_mostly
;
387 static atomic_t nr_switch_events __read_mostly
;
389 static LIST_HEAD(pmus
);
390 static DEFINE_MUTEX(pmus_lock
);
391 static struct srcu_struct pmus_srcu
;
394 * perf event paranoia level:
395 * -1 - not paranoid at all
396 * 0 - disallow raw tracepoint access for unpriv
397 * 1 - disallow cpu events for unpriv
398 * 2 - disallow kernel profiling for unpriv
400 int sysctl_perf_event_paranoid __read_mostly
= 2;
402 /* Minimum for 512 kiB + 1 user control page */
403 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
406 * max perf event sample rate
408 #define DEFAULT_MAX_SAMPLE_RATE 100000
409 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
410 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
412 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
414 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
415 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
417 static int perf_sample_allowed_ns __read_mostly
=
418 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
420 static void update_perf_cpu_limits(void)
422 u64 tmp
= perf_sample_period_ns
;
424 tmp
*= sysctl_perf_cpu_time_max_percent
;
425 tmp
= div_u64(tmp
, 100);
429 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
432 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
434 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
435 void __user
*buffer
, size_t *lenp
,
438 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
444 * If throttling is disabled don't allow the write:
446 if (sysctl_perf_cpu_time_max_percent
== 100 ||
447 sysctl_perf_cpu_time_max_percent
== 0)
450 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
451 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
452 update_perf_cpu_limits();
457 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
459 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
460 void __user
*buffer
, size_t *lenp
,
463 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
468 if (sysctl_perf_cpu_time_max_percent
== 100 ||
469 sysctl_perf_cpu_time_max_percent
== 0) {
471 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
472 WRITE_ONCE(perf_sample_allowed_ns
, 0);
474 update_perf_cpu_limits();
481 * perf samples are done in some very critical code paths (NMIs).
482 * If they take too much CPU time, the system can lock up and not
483 * get any real work done. This will drop the sample rate when
484 * we detect that events are taking too long.
486 #define NR_ACCUMULATED_SAMPLES 128
487 static DEFINE_PER_CPU(u64
, running_sample_length
);
489 static u64 __report_avg
;
490 static u64 __report_allowed
;
492 static void perf_duration_warn(struct irq_work
*w
)
494 printk_ratelimited(KERN_INFO
495 "perf: interrupt took too long (%lld > %lld), lowering "
496 "kernel.perf_event_max_sample_rate to %d\n",
497 __report_avg
, __report_allowed
,
498 sysctl_perf_event_sample_rate
);
501 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
503 void perf_sample_event_took(u64 sample_len_ns
)
505 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
513 /* Decay the counter by 1 average sample. */
514 running_len
= __this_cpu_read(running_sample_length
);
515 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
516 running_len
+= sample_len_ns
;
517 __this_cpu_write(running_sample_length
, running_len
);
520 * Note: this will be biased artifically low until we have
521 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
522 * from having to maintain a count.
524 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
525 if (avg_len
<= max_len
)
528 __report_avg
= avg_len
;
529 __report_allowed
= max_len
;
532 * Compute a throttle threshold 25% below the current duration.
534 avg_len
+= avg_len
/ 4;
535 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
541 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
542 WRITE_ONCE(max_samples_per_tick
, max
);
544 sysctl_perf_event_sample_rate
= max
* HZ
;
545 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
547 if (!irq_work_queue(&perf_duration_work
)) {
548 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
549 "kernel.perf_event_max_sample_rate to %d\n",
550 __report_avg
, __report_allowed
,
551 sysctl_perf_event_sample_rate
);
555 static atomic64_t perf_event_id
;
557 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
558 enum event_type_t event_type
);
560 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
561 enum event_type_t event_type
,
562 struct task_struct
*task
);
564 static void update_context_time(struct perf_event_context
*ctx
);
565 static u64
perf_event_time(struct perf_event
*event
);
567 void __weak
perf_event_print_debug(void) { }
569 extern __weak
const char *perf_pmu_name(void)
574 static inline u64
perf_clock(void)
576 return local_clock();
579 static inline u64
perf_event_clock(struct perf_event
*event
)
581 return event
->clock();
584 #ifdef CONFIG_CGROUP_PERF
587 perf_cgroup_match(struct perf_event
*event
)
589 struct perf_event_context
*ctx
= event
->ctx
;
590 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
592 /* @event doesn't care about cgroup */
596 /* wants specific cgroup scope but @cpuctx isn't associated with any */
601 * Cgroup scoping is recursive. An event enabled for a cgroup is
602 * also enabled for all its descendant cgroups. If @cpuctx's
603 * cgroup is a descendant of @event's (the test covers identity
604 * case), it's a match.
606 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
607 event
->cgrp
->css
.cgroup
);
610 static inline void perf_detach_cgroup(struct perf_event
*event
)
612 css_put(&event
->cgrp
->css
);
616 static inline int is_cgroup_event(struct perf_event
*event
)
618 return event
->cgrp
!= NULL
;
621 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
623 struct perf_cgroup_info
*t
;
625 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
629 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
631 struct perf_cgroup_info
*info
;
636 info
= this_cpu_ptr(cgrp
->info
);
638 info
->time
+= now
- info
->timestamp
;
639 info
->timestamp
= now
;
642 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
644 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
646 __update_cgrp_time(cgrp_out
);
649 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
651 struct perf_cgroup
*cgrp
;
654 * ensure we access cgroup data only when needed and
655 * when we know the cgroup is pinned (css_get)
657 if (!is_cgroup_event(event
))
660 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
662 * Do not update time when cgroup is not active
664 if (cgrp
== event
->cgrp
)
665 __update_cgrp_time(event
->cgrp
);
669 perf_cgroup_set_timestamp(struct task_struct
*task
,
670 struct perf_event_context
*ctx
)
672 struct perf_cgroup
*cgrp
;
673 struct perf_cgroup_info
*info
;
676 * ctx->lock held by caller
677 * ensure we do not access cgroup data
678 * unless we have the cgroup pinned (css_get)
680 if (!task
|| !ctx
->nr_cgroups
)
683 cgrp
= perf_cgroup_from_task(task
, ctx
);
684 info
= this_cpu_ptr(cgrp
->info
);
685 info
->timestamp
= ctx
->timestamp
;
688 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
690 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
691 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
694 * reschedule events based on the cgroup constraint of task.
696 * mode SWOUT : schedule out everything
697 * mode SWIN : schedule in based on cgroup for next
699 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
701 struct perf_cpu_context
*cpuctx
;
702 struct list_head
*list
;
706 * Disable interrupts and preemption to avoid this CPU's
707 * cgrp_cpuctx_entry to change under us.
709 local_irq_save(flags
);
711 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
712 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
713 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
715 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
716 perf_pmu_disable(cpuctx
->ctx
.pmu
);
718 if (mode
& PERF_CGROUP_SWOUT
) {
719 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
721 * must not be done before ctxswout due
722 * to event_filter_match() in event_sched_out()
727 if (mode
& PERF_CGROUP_SWIN
) {
728 WARN_ON_ONCE(cpuctx
->cgrp
);
730 * set cgrp before ctxsw in to allow
731 * event_filter_match() to not have to pass
733 * we pass the cpuctx->ctx to perf_cgroup_from_task()
734 * because cgorup events are only per-cpu
736 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
738 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
740 perf_pmu_enable(cpuctx
->ctx
.pmu
);
741 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
744 local_irq_restore(flags
);
747 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
748 struct task_struct
*next
)
750 struct perf_cgroup
*cgrp1
;
751 struct perf_cgroup
*cgrp2
= NULL
;
755 * we come here when we know perf_cgroup_events > 0
756 * we do not need to pass the ctx here because we know
757 * we are holding the rcu lock
759 cgrp1
= perf_cgroup_from_task(task
, NULL
);
760 cgrp2
= perf_cgroup_from_task(next
, NULL
);
763 * only schedule out current cgroup events if we know
764 * that we are switching to a different cgroup. Otherwise,
765 * do no touch the cgroup events.
768 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
773 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
774 struct task_struct
*task
)
776 struct perf_cgroup
*cgrp1
;
777 struct perf_cgroup
*cgrp2
= NULL
;
781 * we come here when we know perf_cgroup_events > 0
782 * we do not need to pass the ctx here because we know
783 * we are holding the rcu lock
785 cgrp1
= perf_cgroup_from_task(task
, NULL
);
786 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
789 * only need to schedule in cgroup events if we are changing
790 * cgroup during ctxsw. Cgroup events were not scheduled
791 * out of ctxsw out if that was not the case.
794 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
799 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
800 struct perf_event_attr
*attr
,
801 struct perf_event
*group_leader
)
803 struct perf_cgroup
*cgrp
;
804 struct cgroup_subsys_state
*css
;
805 struct fd f
= fdget(fd
);
811 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
812 &perf_event_cgrp_subsys
);
818 cgrp
= container_of(css
, struct perf_cgroup
, css
);
822 * all events in a group must monitor
823 * the same cgroup because a task belongs
824 * to only one perf cgroup at a time
826 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
827 perf_detach_cgroup(event
);
836 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
838 struct perf_cgroup_info
*t
;
839 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
840 event
->shadow_ctx_time
= now
- t
->timestamp
;
844 perf_cgroup_defer_enabled(struct perf_event
*event
)
847 * when the current task's perf cgroup does not match
848 * the event's, we need to remember to call the
849 * perf_mark_enable() function the first time a task with
850 * a matching perf cgroup is scheduled in.
852 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
853 event
->cgrp_defer_enabled
= 1;
857 perf_cgroup_mark_enabled(struct perf_event
*event
,
858 struct perf_event_context
*ctx
)
860 struct perf_event
*sub
;
861 u64 tstamp
= perf_event_time(event
);
863 if (!event
->cgrp_defer_enabled
)
866 event
->cgrp_defer_enabled
= 0;
868 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
869 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
870 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
871 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
872 sub
->cgrp_defer_enabled
= 0;
878 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
879 * cleared when last cgroup event is removed.
882 list_update_cgroup_event(struct perf_event
*event
,
883 struct perf_event_context
*ctx
, bool add
)
885 struct perf_cpu_context
*cpuctx
;
886 struct list_head
*cpuctx_entry
;
888 if (!is_cgroup_event(event
))
891 if (add
&& ctx
->nr_cgroups
++)
893 else if (!add
&& --ctx
->nr_cgroups
)
896 * Because cgroup events are always per-cpu events,
897 * this will always be called from the right CPU.
899 cpuctx
= __get_cpu_context(ctx
);
900 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
901 /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/
903 list_add(cpuctx_entry
, this_cpu_ptr(&cgrp_cpuctx_list
));
904 if (perf_cgroup_from_task(current
, ctx
) == event
->cgrp
)
905 cpuctx
->cgrp
= event
->cgrp
;
907 list_del(cpuctx_entry
);
912 #else /* !CONFIG_CGROUP_PERF */
915 perf_cgroup_match(struct perf_event
*event
)
920 static inline void perf_detach_cgroup(struct perf_event
*event
)
923 static inline int is_cgroup_event(struct perf_event
*event
)
928 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
933 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
937 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
941 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
942 struct task_struct
*next
)
946 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
947 struct task_struct
*task
)
951 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
952 struct perf_event_attr
*attr
,
953 struct perf_event
*group_leader
)
959 perf_cgroup_set_timestamp(struct task_struct
*task
,
960 struct perf_event_context
*ctx
)
965 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
970 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
974 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
980 perf_cgroup_defer_enabled(struct perf_event
*event
)
985 perf_cgroup_mark_enabled(struct perf_event
*event
,
986 struct perf_event_context
*ctx
)
991 list_update_cgroup_event(struct perf_event
*event
,
992 struct perf_event_context
*ctx
, bool add
)
999 * set default to be dependent on timer tick just
1000 * like original code
1002 #define PERF_CPU_HRTIMER (1000 / HZ)
1004 * function must be called with interrupts disabled
1006 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1008 struct perf_cpu_context
*cpuctx
;
1011 WARN_ON(!irqs_disabled());
1013 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1014 rotations
= perf_rotate_context(cpuctx
);
1016 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1018 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1020 cpuctx
->hrtimer_active
= 0;
1021 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1023 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1026 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1028 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1029 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1032 /* no multiplexing needed for SW PMU */
1033 if (pmu
->task_ctx_nr
== perf_sw_context
)
1037 * check default is sane, if not set then force to
1038 * default interval (1/tick)
1040 interval
= pmu
->hrtimer_interval_ms
;
1042 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1044 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1046 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1047 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1048 timer
->function
= perf_mux_hrtimer_handler
;
1051 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1053 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1054 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1055 unsigned long flags
;
1057 /* not for SW PMU */
1058 if (pmu
->task_ctx_nr
== perf_sw_context
)
1061 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1062 if (!cpuctx
->hrtimer_active
) {
1063 cpuctx
->hrtimer_active
= 1;
1064 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1065 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1067 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1072 void perf_pmu_disable(struct pmu
*pmu
)
1074 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1076 pmu
->pmu_disable(pmu
);
1079 void perf_pmu_enable(struct pmu
*pmu
)
1081 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1083 pmu
->pmu_enable(pmu
);
1086 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1089 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1090 * perf_event_task_tick() are fully serialized because they're strictly cpu
1091 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1092 * disabled, while perf_event_task_tick is called from IRQ context.
1094 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1096 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1098 WARN_ON(!irqs_disabled());
1100 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1102 list_add(&ctx
->active_ctx_list
, head
);
1105 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1107 WARN_ON(!irqs_disabled());
1109 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1111 list_del_init(&ctx
->active_ctx_list
);
1114 static void get_ctx(struct perf_event_context
*ctx
)
1116 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1119 static void free_ctx(struct rcu_head
*head
)
1121 struct perf_event_context
*ctx
;
1123 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1124 kfree(ctx
->task_ctx_data
);
1128 static void put_ctx(struct perf_event_context
*ctx
)
1130 if (atomic_dec_and_test(&ctx
->refcount
)) {
1131 if (ctx
->parent_ctx
)
1132 put_ctx(ctx
->parent_ctx
);
1133 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1134 put_task_struct(ctx
->task
);
1135 call_rcu(&ctx
->rcu_head
, free_ctx
);
1140 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1141 * perf_pmu_migrate_context() we need some magic.
1143 * Those places that change perf_event::ctx will hold both
1144 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1146 * Lock ordering is by mutex address. There are two other sites where
1147 * perf_event_context::mutex nests and those are:
1149 * - perf_event_exit_task_context() [ child , 0 ]
1150 * perf_event_exit_event()
1151 * put_event() [ parent, 1 ]
1153 * - perf_event_init_context() [ parent, 0 ]
1154 * inherit_task_group()
1157 * perf_event_alloc()
1159 * perf_try_init_event() [ child , 1 ]
1161 * While it appears there is an obvious deadlock here -- the parent and child
1162 * nesting levels are inverted between the two. This is in fact safe because
1163 * life-time rules separate them. That is an exiting task cannot fork, and a
1164 * spawning task cannot (yet) exit.
1166 * But remember that that these are parent<->child context relations, and
1167 * migration does not affect children, therefore these two orderings should not
1170 * The change in perf_event::ctx does not affect children (as claimed above)
1171 * because the sys_perf_event_open() case will install a new event and break
1172 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1173 * concerned with cpuctx and that doesn't have children.
1175 * The places that change perf_event::ctx will issue:
1177 * perf_remove_from_context();
1178 * synchronize_rcu();
1179 * perf_install_in_context();
1181 * to affect the change. The remove_from_context() + synchronize_rcu() should
1182 * quiesce the event, after which we can install it in the new location. This
1183 * means that only external vectors (perf_fops, prctl) can perturb the event
1184 * while in transit. Therefore all such accessors should also acquire
1185 * perf_event_context::mutex to serialize against this.
1187 * However; because event->ctx can change while we're waiting to acquire
1188 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1193 * task_struct::perf_event_mutex
1194 * perf_event_context::mutex
1195 * perf_event::child_mutex;
1196 * perf_event_context::lock
1197 * perf_event::mmap_mutex
1200 static struct perf_event_context
*
1201 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1203 struct perf_event_context
*ctx
;
1207 ctx
= ACCESS_ONCE(event
->ctx
);
1208 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1214 mutex_lock_nested(&ctx
->mutex
, nesting
);
1215 if (event
->ctx
!= ctx
) {
1216 mutex_unlock(&ctx
->mutex
);
1224 static inline struct perf_event_context
*
1225 perf_event_ctx_lock(struct perf_event
*event
)
1227 return perf_event_ctx_lock_nested(event
, 0);
1230 static void perf_event_ctx_unlock(struct perf_event
*event
,
1231 struct perf_event_context
*ctx
)
1233 mutex_unlock(&ctx
->mutex
);
1238 * This must be done under the ctx->lock, such as to serialize against
1239 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1240 * calling scheduler related locks and ctx->lock nests inside those.
1242 static __must_check
struct perf_event_context
*
1243 unclone_ctx(struct perf_event_context
*ctx
)
1245 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1247 lockdep_assert_held(&ctx
->lock
);
1250 ctx
->parent_ctx
= NULL
;
1256 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1259 * only top level events have the pid namespace they were created in
1262 event
= event
->parent
;
1264 return task_tgid_nr_ns(p
, event
->ns
);
1267 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1270 * only top level events have the pid namespace they were created in
1273 event
= event
->parent
;
1275 return task_pid_nr_ns(p
, event
->ns
);
1279 * If we inherit events we want to return the parent event id
1282 static u64
primary_event_id(struct perf_event
*event
)
1287 id
= event
->parent
->id
;
1293 * Get the perf_event_context for a task and lock it.
1295 * This has to cope with with the fact that until it is locked,
1296 * the context could get moved to another task.
1298 static struct perf_event_context
*
1299 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1301 struct perf_event_context
*ctx
;
1305 * One of the few rules of preemptible RCU is that one cannot do
1306 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1307 * part of the read side critical section was irqs-enabled -- see
1308 * rcu_read_unlock_special().
1310 * Since ctx->lock nests under rq->lock we must ensure the entire read
1311 * side critical section has interrupts disabled.
1313 local_irq_save(*flags
);
1315 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1318 * If this context is a clone of another, it might
1319 * get swapped for another underneath us by
1320 * perf_event_task_sched_out, though the
1321 * rcu_read_lock() protects us from any context
1322 * getting freed. Lock the context and check if it
1323 * got swapped before we could get the lock, and retry
1324 * if so. If we locked the right context, then it
1325 * can't get swapped on us any more.
1327 raw_spin_lock(&ctx
->lock
);
1328 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1329 raw_spin_unlock(&ctx
->lock
);
1331 local_irq_restore(*flags
);
1335 if (ctx
->task
== TASK_TOMBSTONE
||
1336 !atomic_inc_not_zero(&ctx
->refcount
)) {
1337 raw_spin_unlock(&ctx
->lock
);
1340 WARN_ON_ONCE(ctx
->task
!= task
);
1345 local_irq_restore(*flags
);
1350 * Get the context for a task and increment its pin_count so it
1351 * can't get swapped to another task. This also increments its
1352 * reference count so that the context can't get freed.
1354 static struct perf_event_context
*
1355 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1357 struct perf_event_context
*ctx
;
1358 unsigned long flags
;
1360 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1363 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1368 static void perf_unpin_context(struct perf_event_context
*ctx
)
1370 unsigned long flags
;
1372 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1374 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1378 * Update the record of the current time in a context.
1380 static void update_context_time(struct perf_event_context
*ctx
)
1382 u64 now
= perf_clock();
1384 ctx
->time
+= now
- ctx
->timestamp
;
1385 ctx
->timestamp
= now
;
1388 static u64
perf_event_time(struct perf_event
*event
)
1390 struct perf_event_context
*ctx
= event
->ctx
;
1392 if (is_cgroup_event(event
))
1393 return perf_cgroup_event_time(event
);
1395 return ctx
? ctx
->time
: 0;
1399 * Update the total_time_enabled and total_time_running fields for a event.
1401 static void update_event_times(struct perf_event
*event
)
1403 struct perf_event_context
*ctx
= event
->ctx
;
1406 lockdep_assert_held(&ctx
->lock
);
1408 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1409 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1413 * in cgroup mode, time_enabled represents
1414 * the time the event was enabled AND active
1415 * tasks were in the monitored cgroup. This is
1416 * independent of the activity of the context as
1417 * there may be a mix of cgroup and non-cgroup events.
1419 * That is why we treat cgroup events differently
1422 if (is_cgroup_event(event
))
1423 run_end
= perf_cgroup_event_time(event
);
1424 else if (ctx
->is_active
)
1425 run_end
= ctx
->time
;
1427 run_end
= event
->tstamp_stopped
;
1429 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1431 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1432 run_end
= event
->tstamp_stopped
;
1434 run_end
= perf_event_time(event
);
1436 event
->total_time_running
= run_end
- event
->tstamp_running
;
1441 * Update total_time_enabled and total_time_running for all events in a group.
1443 static void update_group_times(struct perf_event
*leader
)
1445 struct perf_event
*event
;
1447 update_event_times(leader
);
1448 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1449 update_event_times(event
);
1452 static enum event_type_t
get_event_type(struct perf_event
*event
)
1454 struct perf_event_context
*ctx
= event
->ctx
;
1455 enum event_type_t event_type
;
1457 lockdep_assert_held(&ctx
->lock
);
1459 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1461 event_type
|= EVENT_CPU
;
1466 static struct list_head
*
1467 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1469 if (event
->attr
.pinned
)
1470 return &ctx
->pinned_groups
;
1472 return &ctx
->flexible_groups
;
1476 * Add a event from the lists for its context.
1477 * Must be called with ctx->mutex and ctx->lock held.
1480 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1482 lockdep_assert_held(&ctx
->lock
);
1484 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1485 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1488 * If we're a stand alone event or group leader, we go to the context
1489 * list, group events are kept attached to the group so that
1490 * perf_group_detach can, at all times, locate all siblings.
1492 if (event
->group_leader
== event
) {
1493 struct list_head
*list
;
1495 event
->group_caps
= event
->event_caps
;
1497 list
= ctx_group_list(event
, ctx
);
1498 list_add_tail(&event
->group_entry
, list
);
1501 list_update_cgroup_event(event
, ctx
, true);
1503 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1505 if (event
->attr
.inherit_stat
)
1512 * Initialize event state based on the perf_event_attr::disabled.
1514 static inline void perf_event__state_init(struct perf_event
*event
)
1516 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1517 PERF_EVENT_STATE_INACTIVE
;
1520 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1522 int entry
= sizeof(u64
); /* value */
1526 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1527 size
+= sizeof(u64
);
1529 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1530 size
+= sizeof(u64
);
1532 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1533 entry
+= sizeof(u64
);
1535 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1537 size
+= sizeof(u64
);
1541 event
->read_size
= size
;
1544 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1546 struct perf_sample_data
*data
;
1549 if (sample_type
& PERF_SAMPLE_IP
)
1550 size
+= sizeof(data
->ip
);
1552 if (sample_type
& PERF_SAMPLE_ADDR
)
1553 size
+= sizeof(data
->addr
);
1555 if (sample_type
& PERF_SAMPLE_PERIOD
)
1556 size
+= sizeof(data
->period
);
1558 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1559 size
+= sizeof(data
->weight
);
1561 if (sample_type
& PERF_SAMPLE_READ
)
1562 size
+= event
->read_size
;
1564 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1565 size
+= sizeof(data
->data_src
.val
);
1567 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1568 size
+= sizeof(data
->txn
);
1570 event
->header_size
= size
;
1574 * Called at perf_event creation and when events are attached/detached from a
1577 static void perf_event__header_size(struct perf_event
*event
)
1579 __perf_event_read_size(event
,
1580 event
->group_leader
->nr_siblings
);
1581 __perf_event_header_size(event
, event
->attr
.sample_type
);
1584 static void perf_event__id_header_size(struct perf_event
*event
)
1586 struct perf_sample_data
*data
;
1587 u64 sample_type
= event
->attr
.sample_type
;
1590 if (sample_type
& PERF_SAMPLE_TID
)
1591 size
+= sizeof(data
->tid_entry
);
1593 if (sample_type
& PERF_SAMPLE_TIME
)
1594 size
+= sizeof(data
->time
);
1596 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1597 size
+= sizeof(data
->id
);
1599 if (sample_type
& PERF_SAMPLE_ID
)
1600 size
+= sizeof(data
->id
);
1602 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1603 size
+= sizeof(data
->stream_id
);
1605 if (sample_type
& PERF_SAMPLE_CPU
)
1606 size
+= sizeof(data
->cpu_entry
);
1608 event
->id_header_size
= size
;
1611 static bool perf_event_validate_size(struct perf_event
*event
)
1614 * The values computed here will be over-written when we actually
1617 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1618 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1619 perf_event__id_header_size(event
);
1622 * Sum the lot; should not exceed the 64k limit we have on records.
1623 * Conservative limit to allow for callchains and other variable fields.
1625 if (event
->read_size
+ event
->header_size
+
1626 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1632 static void perf_group_attach(struct perf_event
*event
)
1634 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1636 lockdep_assert_held(&event
->ctx
->lock
);
1639 * We can have double attach due to group movement in perf_event_open.
1641 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1644 event
->attach_state
|= PERF_ATTACH_GROUP
;
1646 if (group_leader
== event
)
1649 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1651 group_leader
->group_caps
&= event
->event_caps
;
1653 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1654 group_leader
->nr_siblings
++;
1656 perf_event__header_size(group_leader
);
1658 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1659 perf_event__header_size(pos
);
1663 * Remove a event from the lists for its context.
1664 * Must be called with ctx->mutex and ctx->lock held.
1667 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1669 WARN_ON_ONCE(event
->ctx
!= ctx
);
1670 lockdep_assert_held(&ctx
->lock
);
1673 * We can have double detach due to exit/hot-unplug + close.
1675 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1678 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1680 list_update_cgroup_event(event
, ctx
, false);
1683 if (event
->attr
.inherit_stat
)
1686 list_del_rcu(&event
->event_entry
);
1688 if (event
->group_leader
== event
)
1689 list_del_init(&event
->group_entry
);
1691 update_group_times(event
);
1694 * If event was in error state, then keep it
1695 * that way, otherwise bogus counts will be
1696 * returned on read(). The only way to get out
1697 * of error state is by explicit re-enabling
1700 if (event
->state
> PERF_EVENT_STATE_OFF
)
1701 event
->state
= PERF_EVENT_STATE_OFF
;
1706 static void perf_group_detach(struct perf_event
*event
)
1708 struct perf_event
*sibling
, *tmp
;
1709 struct list_head
*list
= NULL
;
1711 lockdep_assert_held(&event
->ctx
->lock
);
1714 * We can have double detach due to exit/hot-unplug + close.
1716 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1719 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1722 * If this is a sibling, remove it from its group.
1724 if (event
->group_leader
!= event
) {
1725 list_del_init(&event
->group_entry
);
1726 event
->group_leader
->nr_siblings
--;
1730 if (!list_empty(&event
->group_entry
))
1731 list
= &event
->group_entry
;
1734 * If this was a group event with sibling events then
1735 * upgrade the siblings to singleton events by adding them
1736 * to whatever list we are on.
1738 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1740 list_move_tail(&sibling
->group_entry
, list
);
1741 sibling
->group_leader
= sibling
;
1743 /* Inherit group flags from the previous leader */
1744 sibling
->group_caps
= event
->group_caps
;
1746 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1750 perf_event__header_size(event
->group_leader
);
1752 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1753 perf_event__header_size(tmp
);
1756 static bool is_orphaned_event(struct perf_event
*event
)
1758 return event
->state
== PERF_EVENT_STATE_DEAD
;
1761 static inline int __pmu_filter_match(struct perf_event
*event
)
1763 struct pmu
*pmu
= event
->pmu
;
1764 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1768 * Check whether we should attempt to schedule an event group based on
1769 * PMU-specific filtering. An event group can consist of HW and SW events,
1770 * potentially with a SW leader, so we must check all the filters, to
1771 * determine whether a group is schedulable:
1773 static inline int pmu_filter_match(struct perf_event
*event
)
1775 struct perf_event
*child
;
1777 if (!__pmu_filter_match(event
))
1780 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1781 if (!__pmu_filter_match(child
))
1789 event_filter_match(struct perf_event
*event
)
1791 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1792 perf_cgroup_match(event
) && pmu_filter_match(event
);
1796 event_sched_out(struct perf_event
*event
,
1797 struct perf_cpu_context
*cpuctx
,
1798 struct perf_event_context
*ctx
)
1800 u64 tstamp
= perf_event_time(event
);
1803 WARN_ON_ONCE(event
->ctx
!= ctx
);
1804 lockdep_assert_held(&ctx
->lock
);
1807 * An event which could not be activated because of
1808 * filter mismatch still needs to have its timings
1809 * maintained, otherwise bogus information is return
1810 * via read() for time_enabled, time_running:
1812 if (event
->state
== PERF_EVENT_STATE_INACTIVE
&&
1813 !event_filter_match(event
)) {
1814 delta
= tstamp
- event
->tstamp_stopped
;
1815 event
->tstamp_running
+= delta
;
1816 event
->tstamp_stopped
= tstamp
;
1819 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1822 perf_pmu_disable(event
->pmu
);
1824 event
->tstamp_stopped
= tstamp
;
1825 event
->pmu
->del(event
, 0);
1827 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1828 if (event
->pending_disable
) {
1829 event
->pending_disable
= 0;
1830 event
->state
= PERF_EVENT_STATE_OFF
;
1833 if (!is_software_event(event
))
1834 cpuctx
->active_oncpu
--;
1835 if (!--ctx
->nr_active
)
1836 perf_event_ctx_deactivate(ctx
);
1837 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1839 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1840 cpuctx
->exclusive
= 0;
1842 perf_pmu_enable(event
->pmu
);
1846 group_sched_out(struct perf_event
*group_event
,
1847 struct perf_cpu_context
*cpuctx
,
1848 struct perf_event_context
*ctx
)
1850 struct perf_event
*event
;
1851 int state
= group_event
->state
;
1853 perf_pmu_disable(ctx
->pmu
);
1855 event_sched_out(group_event
, cpuctx
, ctx
);
1858 * Schedule out siblings (if any):
1860 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1861 event_sched_out(event
, cpuctx
, ctx
);
1863 perf_pmu_enable(ctx
->pmu
);
1865 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1866 cpuctx
->exclusive
= 0;
1869 #define DETACH_GROUP 0x01UL
1872 * Cross CPU call to remove a performance event
1874 * We disable the event on the hardware level first. After that we
1875 * remove it from the context list.
1878 __perf_remove_from_context(struct perf_event
*event
,
1879 struct perf_cpu_context
*cpuctx
,
1880 struct perf_event_context
*ctx
,
1883 unsigned long flags
= (unsigned long)info
;
1885 event_sched_out(event
, cpuctx
, ctx
);
1886 if (flags
& DETACH_GROUP
)
1887 perf_group_detach(event
);
1888 list_del_event(event
, ctx
);
1890 if (!ctx
->nr_events
&& ctx
->is_active
) {
1893 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1894 cpuctx
->task_ctx
= NULL
;
1900 * Remove the event from a task's (or a CPU's) list of events.
1902 * If event->ctx is a cloned context, callers must make sure that
1903 * every task struct that event->ctx->task could possibly point to
1904 * remains valid. This is OK when called from perf_release since
1905 * that only calls us on the top-level context, which can't be a clone.
1906 * When called from perf_event_exit_task, it's OK because the
1907 * context has been detached from its task.
1909 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1911 struct perf_event_context
*ctx
= event
->ctx
;
1913 lockdep_assert_held(&ctx
->mutex
);
1915 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1918 * The above event_function_call() can NO-OP when it hits
1919 * TASK_TOMBSTONE. In that case we must already have been detached
1920 * from the context (by perf_event_exit_event()) but the grouping
1921 * might still be in-tact.
1923 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1924 if ((flags
& DETACH_GROUP
) &&
1925 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
1927 * Since in that case we cannot possibly be scheduled, simply
1930 raw_spin_lock_irq(&ctx
->lock
);
1931 perf_group_detach(event
);
1932 raw_spin_unlock_irq(&ctx
->lock
);
1937 * Cross CPU call to disable a performance event
1939 static void __perf_event_disable(struct perf_event
*event
,
1940 struct perf_cpu_context
*cpuctx
,
1941 struct perf_event_context
*ctx
,
1944 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1947 update_context_time(ctx
);
1948 update_cgrp_time_from_event(event
);
1949 update_group_times(event
);
1950 if (event
== event
->group_leader
)
1951 group_sched_out(event
, cpuctx
, ctx
);
1953 event_sched_out(event
, cpuctx
, ctx
);
1954 event
->state
= PERF_EVENT_STATE_OFF
;
1960 * If event->ctx is a cloned context, callers must make sure that
1961 * every task struct that event->ctx->task could possibly point to
1962 * remains valid. This condition is satisifed when called through
1963 * perf_event_for_each_child or perf_event_for_each because they
1964 * hold the top-level event's child_mutex, so any descendant that
1965 * goes to exit will block in perf_event_exit_event().
1967 * When called from perf_pending_event it's OK because event->ctx
1968 * is the current context on this CPU and preemption is disabled,
1969 * hence we can't get into perf_event_task_sched_out for this context.
1971 static void _perf_event_disable(struct perf_event
*event
)
1973 struct perf_event_context
*ctx
= event
->ctx
;
1975 raw_spin_lock_irq(&ctx
->lock
);
1976 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1977 raw_spin_unlock_irq(&ctx
->lock
);
1980 raw_spin_unlock_irq(&ctx
->lock
);
1982 event_function_call(event
, __perf_event_disable
, NULL
);
1985 void perf_event_disable_local(struct perf_event
*event
)
1987 event_function_local(event
, __perf_event_disable
, NULL
);
1991 * Strictly speaking kernel users cannot create groups and therefore this
1992 * interface does not need the perf_event_ctx_lock() magic.
1994 void perf_event_disable(struct perf_event
*event
)
1996 struct perf_event_context
*ctx
;
1998 ctx
= perf_event_ctx_lock(event
);
1999 _perf_event_disable(event
);
2000 perf_event_ctx_unlock(event
, ctx
);
2002 EXPORT_SYMBOL_GPL(perf_event_disable
);
2004 void perf_event_disable_inatomic(struct perf_event
*event
)
2006 event
->pending_disable
= 1;
2007 irq_work_queue(&event
->pending
);
2010 static void perf_set_shadow_time(struct perf_event
*event
,
2011 struct perf_event_context
*ctx
,
2015 * use the correct time source for the time snapshot
2017 * We could get by without this by leveraging the
2018 * fact that to get to this function, the caller
2019 * has most likely already called update_context_time()
2020 * and update_cgrp_time_xx() and thus both timestamp
2021 * are identical (or very close). Given that tstamp is,
2022 * already adjusted for cgroup, we could say that:
2023 * tstamp - ctx->timestamp
2025 * tstamp - cgrp->timestamp.
2027 * Then, in perf_output_read(), the calculation would
2028 * work with no changes because:
2029 * - event is guaranteed scheduled in
2030 * - no scheduled out in between
2031 * - thus the timestamp would be the same
2033 * But this is a bit hairy.
2035 * So instead, we have an explicit cgroup call to remain
2036 * within the time time source all along. We believe it
2037 * is cleaner and simpler to understand.
2039 if (is_cgroup_event(event
))
2040 perf_cgroup_set_shadow_time(event
, tstamp
);
2042 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
2045 #define MAX_INTERRUPTS (~0ULL)
2047 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2048 static void perf_log_itrace_start(struct perf_event
*event
);
2051 event_sched_in(struct perf_event
*event
,
2052 struct perf_cpu_context
*cpuctx
,
2053 struct perf_event_context
*ctx
)
2055 u64 tstamp
= perf_event_time(event
);
2058 lockdep_assert_held(&ctx
->lock
);
2060 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2063 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2065 * Order event::oncpu write to happen before the ACTIVE state
2069 WRITE_ONCE(event
->state
, PERF_EVENT_STATE_ACTIVE
);
2072 * Unthrottle events, since we scheduled we might have missed several
2073 * ticks already, also for a heavily scheduling task there is little
2074 * guarantee it'll get a tick in a timely manner.
2076 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2077 perf_log_throttle(event
, 1);
2078 event
->hw
.interrupts
= 0;
2082 * The new state must be visible before we turn it on in the hardware:
2086 perf_pmu_disable(event
->pmu
);
2088 perf_set_shadow_time(event
, ctx
, tstamp
);
2090 perf_log_itrace_start(event
);
2092 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2093 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2099 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
2101 if (!is_software_event(event
))
2102 cpuctx
->active_oncpu
++;
2103 if (!ctx
->nr_active
++)
2104 perf_event_ctx_activate(ctx
);
2105 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2108 if (event
->attr
.exclusive
)
2109 cpuctx
->exclusive
= 1;
2112 perf_pmu_enable(event
->pmu
);
2118 group_sched_in(struct perf_event
*group_event
,
2119 struct perf_cpu_context
*cpuctx
,
2120 struct perf_event_context
*ctx
)
2122 struct perf_event
*event
, *partial_group
= NULL
;
2123 struct pmu
*pmu
= ctx
->pmu
;
2124 u64 now
= ctx
->time
;
2125 bool simulate
= false;
2127 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2130 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2132 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2133 pmu
->cancel_txn(pmu
);
2134 perf_mux_hrtimer_restart(cpuctx
);
2139 * Schedule in siblings as one group (if any):
2141 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2142 if (event_sched_in(event
, cpuctx
, ctx
)) {
2143 partial_group
= event
;
2148 if (!pmu
->commit_txn(pmu
))
2153 * Groups can be scheduled in as one unit only, so undo any
2154 * partial group before returning:
2155 * The events up to the failed event are scheduled out normally,
2156 * tstamp_stopped will be updated.
2158 * The failed events and the remaining siblings need to have
2159 * their timings updated as if they had gone thru event_sched_in()
2160 * and event_sched_out(). This is required to get consistent timings
2161 * across the group. This also takes care of the case where the group
2162 * could never be scheduled by ensuring tstamp_stopped is set to mark
2163 * the time the event was actually stopped, such that time delta
2164 * calculation in update_event_times() is correct.
2166 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2167 if (event
== partial_group
)
2171 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2172 event
->tstamp_stopped
= now
;
2174 event_sched_out(event
, cpuctx
, ctx
);
2177 event_sched_out(group_event
, cpuctx
, ctx
);
2179 pmu
->cancel_txn(pmu
);
2181 perf_mux_hrtimer_restart(cpuctx
);
2187 * Work out whether we can put this event group on the CPU now.
2189 static int group_can_go_on(struct perf_event
*event
,
2190 struct perf_cpu_context
*cpuctx
,
2194 * Groups consisting entirely of software events can always go on.
2196 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2199 * If an exclusive group is already on, no other hardware
2202 if (cpuctx
->exclusive
)
2205 * If this group is exclusive and there are already
2206 * events on the CPU, it can't go on.
2208 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2211 * Otherwise, try to add it if all previous groups were able
2217 static void add_event_to_ctx(struct perf_event
*event
,
2218 struct perf_event_context
*ctx
)
2220 u64 tstamp
= perf_event_time(event
);
2222 list_add_event(event
, ctx
);
2223 perf_group_attach(event
);
2224 event
->tstamp_enabled
= tstamp
;
2225 event
->tstamp_running
= tstamp
;
2226 event
->tstamp_stopped
= tstamp
;
2229 static void ctx_sched_out(struct perf_event_context
*ctx
,
2230 struct perf_cpu_context
*cpuctx
,
2231 enum event_type_t event_type
);
2233 ctx_sched_in(struct perf_event_context
*ctx
,
2234 struct perf_cpu_context
*cpuctx
,
2235 enum event_type_t event_type
,
2236 struct task_struct
*task
);
2238 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2239 struct perf_event_context
*ctx
,
2240 enum event_type_t event_type
)
2242 if (!cpuctx
->task_ctx
)
2245 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2248 ctx_sched_out(ctx
, cpuctx
, event_type
);
2251 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2252 struct perf_event_context
*ctx
,
2253 struct task_struct
*task
)
2255 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2257 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2258 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2260 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2264 * We want to maintain the following priority of scheduling:
2265 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2266 * - task pinned (EVENT_PINNED)
2267 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2268 * - task flexible (EVENT_FLEXIBLE).
2270 * In order to avoid unscheduling and scheduling back in everything every
2271 * time an event is added, only do it for the groups of equal priority and
2274 * This can be called after a batch operation on task events, in which case
2275 * event_type is a bit mask of the types of events involved. For CPU events,
2276 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2278 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2279 struct perf_event_context
*task_ctx
,
2280 enum event_type_t event_type
)
2282 enum event_type_t ctx_event_type
= event_type
& EVENT_ALL
;
2283 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2286 * If pinned groups are involved, flexible groups also need to be
2289 if (event_type
& EVENT_PINNED
)
2290 event_type
|= EVENT_FLEXIBLE
;
2292 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2294 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2297 * Decide which cpu ctx groups to schedule out based on the types
2298 * of events that caused rescheduling:
2299 * - EVENT_CPU: schedule out corresponding groups;
2300 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2301 * - otherwise, do nothing more.
2304 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2305 else if (ctx_event_type
& EVENT_PINNED
)
2306 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2308 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2309 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2313 * Cross CPU call to install and enable a performance event
2315 * Very similar to remote_function() + event_function() but cannot assume that
2316 * things like ctx->is_active and cpuctx->task_ctx are set.
2318 static int __perf_install_in_context(void *info
)
2320 struct perf_event
*event
= info
;
2321 struct perf_event_context
*ctx
= event
->ctx
;
2322 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2323 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2324 bool reprogram
= true;
2327 raw_spin_lock(&cpuctx
->ctx
.lock
);
2329 raw_spin_lock(&ctx
->lock
);
2332 reprogram
= (ctx
->task
== current
);
2335 * If the task is running, it must be running on this CPU,
2336 * otherwise we cannot reprogram things.
2338 * If its not running, we don't care, ctx->lock will
2339 * serialize against it becoming runnable.
2341 if (task_curr(ctx
->task
) && !reprogram
) {
2346 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2347 } else if (task_ctx
) {
2348 raw_spin_lock(&task_ctx
->lock
);
2352 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2353 add_event_to_ctx(event
, ctx
);
2354 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2356 add_event_to_ctx(event
, ctx
);
2360 perf_ctx_unlock(cpuctx
, task_ctx
);
2366 * Attach a performance event to a context.
2368 * Very similar to event_function_call, see comment there.
2371 perf_install_in_context(struct perf_event_context
*ctx
,
2372 struct perf_event
*event
,
2375 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2377 lockdep_assert_held(&ctx
->mutex
);
2379 if (event
->cpu
!= -1)
2383 * Ensures that if we can observe event->ctx, both the event and ctx
2384 * will be 'complete'. See perf_iterate_sb_cpu().
2386 smp_store_release(&event
->ctx
, ctx
);
2389 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2394 * Should not happen, we validate the ctx is still alive before calling.
2396 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2400 * Installing events is tricky because we cannot rely on ctx->is_active
2401 * to be set in case this is the nr_events 0 -> 1 transition.
2403 * Instead we use task_curr(), which tells us if the task is running.
2404 * However, since we use task_curr() outside of rq::lock, we can race
2405 * against the actual state. This means the result can be wrong.
2407 * If we get a false positive, we retry, this is harmless.
2409 * If we get a false negative, things are complicated. If we are after
2410 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2411 * value must be correct. If we're before, it doesn't matter since
2412 * perf_event_context_sched_in() will program the counter.
2414 * However, this hinges on the remote context switch having observed
2415 * our task->perf_event_ctxp[] store, such that it will in fact take
2416 * ctx::lock in perf_event_context_sched_in().
2418 * We do this by task_function_call(), if the IPI fails to hit the task
2419 * we know any future context switch of task must see the
2420 * perf_event_ctpx[] store.
2424 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2425 * task_cpu() load, such that if the IPI then does not find the task
2426 * running, a future context switch of that task must observe the
2431 if (!task_function_call(task
, __perf_install_in_context
, event
))
2434 raw_spin_lock_irq(&ctx
->lock
);
2436 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2438 * Cannot happen because we already checked above (which also
2439 * cannot happen), and we hold ctx->mutex, which serializes us
2440 * against perf_event_exit_task_context().
2442 raw_spin_unlock_irq(&ctx
->lock
);
2446 * If the task is not running, ctx->lock will avoid it becoming so,
2447 * thus we can safely install the event.
2449 if (task_curr(task
)) {
2450 raw_spin_unlock_irq(&ctx
->lock
);
2453 add_event_to_ctx(event
, ctx
);
2454 raw_spin_unlock_irq(&ctx
->lock
);
2458 * Put a event into inactive state and update time fields.
2459 * Enabling the leader of a group effectively enables all
2460 * the group members that aren't explicitly disabled, so we
2461 * have to update their ->tstamp_enabled also.
2462 * Note: this works for group members as well as group leaders
2463 * since the non-leader members' sibling_lists will be empty.
2465 static void __perf_event_mark_enabled(struct perf_event
*event
)
2467 struct perf_event
*sub
;
2468 u64 tstamp
= perf_event_time(event
);
2470 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2471 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2472 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2473 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2474 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2479 * Cross CPU call to enable a performance event
2481 static void __perf_event_enable(struct perf_event
*event
,
2482 struct perf_cpu_context
*cpuctx
,
2483 struct perf_event_context
*ctx
,
2486 struct perf_event
*leader
= event
->group_leader
;
2487 struct perf_event_context
*task_ctx
;
2489 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2490 event
->state
<= PERF_EVENT_STATE_ERROR
)
2494 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2496 __perf_event_mark_enabled(event
);
2498 if (!ctx
->is_active
)
2501 if (!event_filter_match(event
)) {
2502 if (is_cgroup_event(event
))
2503 perf_cgroup_defer_enabled(event
);
2504 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2509 * If the event is in a group and isn't the group leader,
2510 * then don't put it on unless the group is on.
2512 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2513 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2517 task_ctx
= cpuctx
->task_ctx
;
2519 WARN_ON_ONCE(task_ctx
!= ctx
);
2521 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2527 * If event->ctx is a cloned context, callers must make sure that
2528 * every task struct that event->ctx->task could possibly point to
2529 * remains valid. This condition is satisfied when called through
2530 * perf_event_for_each_child or perf_event_for_each as described
2531 * for perf_event_disable.
2533 static void _perf_event_enable(struct perf_event
*event
)
2535 struct perf_event_context
*ctx
= event
->ctx
;
2537 raw_spin_lock_irq(&ctx
->lock
);
2538 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2539 event
->state
< PERF_EVENT_STATE_ERROR
) {
2540 raw_spin_unlock_irq(&ctx
->lock
);
2545 * If the event is in error state, clear that first.
2547 * That way, if we see the event in error state below, we know that it
2548 * has gone back into error state, as distinct from the task having
2549 * been scheduled away before the cross-call arrived.
2551 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2552 event
->state
= PERF_EVENT_STATE_OFF
;
2553 raw_spin_unlock_irq(&ctx
->lock
);
2555 event_function_call(event
, __perf_event_enable
, NULL
);
2559 * See perf_event_disable();
2561 void perf_event_enable(struct perf_event
*event
)
2563 struct perf_event_context
*ctx
;
2565 ctx
= perf_event_ctx_lock(event
);
2566 _perf_event_enable(event
);
2567 perf_event_ctx_unlock(event
, ctx
);
2569 EXPORT_SYMBOL_GPL(perf_event_enable
);
2571 struct stop_event_data
{
2572 struct perf_event
*event
;
2573 unsigned int restart
;
2576 static int __perf_event_stop(void *info
)
2578 struct stop_event_data
*sd
= info
;
2579 struct perf_event
*event
= sd
->event
;
2581 /* if it's already INACTIVE, do nothing */
2582 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2585 /* matches smp_wmb() in event_sched_in() */
2589 * There is a window with interrupts enabled before we get here,
2590 * so we need to check again lest we try to stop another CPU's event.
2592 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2595 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2598 * May race with the actual stop (through perf_pmu_output_stop()),
2599 * but it is only used for events with AUX ring buffer, and such
2600 * events will refuse to restart because of rb::aux_mmap_count==0,
2601 * see comments in perf_aux_output_begin().
2603 * Since this is happening on a event-local CPU, no trace is lost
2607 event
->pmu
->start(event
, 0);
2612 static int perf_event_stop(struct perf_event
*event
, int restart
)
2614 struct stop_event_data sd
= {
2621 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2624 /* matches smp_wmb() in event_sched_in() */
2628 * We only want to restart ACTIVE events, so if the event goes
2629 * inactive here (event->oncpu==-1), there's nothing more to do;
2630 * fall through with ret==-ENXIO.
2632 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2633 __perf_event_stop
, &sd
);
2634 } while (ret
== -EAGAIN
);
2640 * In order to contain the amount of racy and tricky in the address filter
2641 * configuration management, it is a two part process:
2643 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2644 * we update the addresses of corresponding vmas in
2645 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2646 * (p2) when an event is scheduled in (pmu::add), it calls
2647 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2648 * if the generation has changed since the previous call.
2650 * If (p1) happens while the event is active, we restart it to force (p2).
2652 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2653 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2655 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2656 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2658 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2661 void perf_event_addr_filters_sync(struct perf_event
*event
)
2663 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2665 if (!has_addr_filter(event
))
2668 raw_spin_lock(&ifh
->lock
);
2669 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2670 event
->pmu
->addr_filters_sync(event
);
2671 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2673 raw_spin_unlock(&ifh
->lock
);
2675 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2677 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2680 * not supported on inherited events
2682 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2685 atomic_add(refresh
, &event
->event_limit
);
2686 _perf_event_enable(event
);
2692 * See perf_event_disable()
2694 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2696 struct perf_event_context
*ctx
;
2699 ctx
= perf_event_ctx_lock(event
);
2700 ret
= _perf_event_refresh(event
, refresh
);
2701 perf_event_ctx_unlock(event
, ctx
);
2705 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2707 static void ctx_sched_out(struct perf_event_context
*ctx
,
2708 struct perf_cpu_context
*cpuctx
,
2709 enum event_type_t event_type
)
2711 int is_active
= ctx
->is_active
;
2712 struct perf_event
*event
;
2714 lockdep_assert_held(&ctx
->lock
);
2716 if (likely(!ctx
->nr_events
)) {
2718 * See __perf_remove_from_context().
2720 WARN_ON_ONCE(ctx
->is_active
);
2722 WARN_ON_ONCE(cpuctx
->task_ctx
);
2726 ctx
->is_active
&= ~event_type
;
2727 if (!(ctx
->is_active
& EVENT_ALL
))
2731 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2732 if (!ctx
->is_active
)
2733 cpuctx
->task_ctx
= NULL
;
2737 * Always update time if it was set; not only when it changes.
2738 * Otherwise we can 'forget' to update time for any but the last
2739 * context we sched out. For example:
2741 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2742 * ctx_sched_out(.event_type = EVENT_PINNED)
2744 * would only update time for the pinned events.
2746 if (is_active
& EVENT_TIME
) {
2747 /* update (and stop) ctx time */
2748 update_context_time(ctx
);
2749 update_cgrp_time_from_cpuctx(cpuctx
);
2752 is_active
^= ctx
->is_active
; /* changed bits */
2754 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2757 perf_pmu_disable(ctx
->pmu
);
2758 if (is_active
& EVENT_PINNED
) {
2759 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2760 group_sched_out(event
, cpuctx
, ctx
);
2763 if (is_active
& EVENT_FLEXIBLE
) {
2764 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2765 group_sched_out(event
, cpuctx
, ctx
);
2767 perf_pmu_enable(ctx
->pmu
);
2771 * Test whether two contexts are equivalent, i.e. whether they have both been
2772 * cloned from the same version of the same context.
2774 * Equivalence is measured using a generation number in the context that is
2775 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2776 * and list_del_event().
2778 static int context_equiv(struct perf_event_context
*ctx1
,
2779 struct perf_event_context
*ctx2
)
2781 lockdep_assert_held(&ctx1
->lock
);
2782 lockdep_assert_held(&ctx2
->lock
);
2784 /* Pinning disables the swap optimization */
2785 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2788 /* If ctx1 is the parent of ctx2 */
2789 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2792 /* If ctx2 is the parent of ctx1 */
2793 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2797 * If ctx1 and ctx2 have the same parent; we flatten the parent
2798 * hierarchy, see perf_event_init_context().
2800 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2801 ctx1
->parent_gen
== ctx2
->parent_gen
)
2808 static void __perf_event_sync_stat(struct perf_event
*event
,
2809 struct perf_event
*next_event
)
2813 if (!event
->attr
.inherit_stat
)
2817 * Update the event value, we cannot use perf_event_read()
2818 * because we're in the middle of a context switch and have IRQs
2819 * disabled, which upsets smp_call_function_single(), however
2820 * we know the event must be on the current CPU, therefore we
2821 * don't need to use it.
2823 switch (event
->state
) {
2824 case PERF_EVENT_STATE_ACTIVE
:
2825 event
->pmu
->read(event
);
2828 case PERF_EVENT_STATE_INACTIVE
:
2829 update_event_times(event
);
2837 * In order to keep per-task stats reliable we need to flip the event
2838 * values when we flip the contexts.
2840 value
= local64_read(&next_event
->count
);
2841 value
= local64_xchg(&event
->count
, value
);
2842 local64_set(&next_event
->count
, value
);
2844 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2845 swap(event
->total_time_running
, next_event
->total_time_running
);
2848 * Since we swizzled the values, update the user visible data too.
2850 perf_event_update_userpage(event
);
2851 perf_event_update_userpage(next_event
);
2854 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2855 struct perf_event_context
*next_ctx
)
2857 struct perf_event
*event
, *next_event
;
2862 update_context_time(ctx
);
2864 event
= list_first_entry(&ctx
->event_list
,
2865 struct perf_event
, event_entry
);
2867 next_event
= list_first_entry(&next_ctx
->event_list
,
2868 struct perf_event
, event_entry
);
2870 while (&event
->event_entry
!= &ctx
->event_list
&&
2871 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2873 __perf_event_sync_stat(event
, next_event
);
2875 event
= list_next_entry(event
, event_entry
);
2876 next_event
= list_next_entry(next_event
, event_entry
);
2880 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2881 struct task_struct
*next
)
2883 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2884 struct perf_event_context
*next_ctx
;
2885 struct perf_event_context
*parent
, *next_parent
;
2886 struct perf_cpu_context
*cpuctx
;
2892 cpuctx
= __get_cpu_context(ctx
);
2893 if (!cpuctx
->task_ctx
)
2897 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2901 parent
= rcu_dereference(ctx
->parent_ctx
);
2902 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2904 /* If neither context have a parent context; they cannot be clones. */
2905 if (!parent
&& !next_parent
)
2908 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2910 * Looks like the two contexts are clones, so we might be
2911 * able to optimize the context switch. We lock both
2912 * contexts and check that they are clones under the
2913 * lock (including re-checking that neither has been
2914 * uncloned in the meantime). It doesn't matter which
2915 * order we take the locks because no other cpu could
2916 * be trying to lock both of these tasks.
2918 raw_spin_lock(&ctx
->lock
);
2919 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2920 if (context_equiv(ctx
, next_ctx
)) {
2921 WRITE_ONCE(ctx
->task
, next
);
2922 WRITE_ONCE(next_ctx
->task
, task
);
2924 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2927 * RCU_INIT_POINTER here is safe because we've not
2928 * modified the ctx and the above modification of
2929 * ctx->task and ctx->task_ctx_data are immaterial
2930 * since those values are always verified under
2931 * ctx->lock which we're now holding.
2933 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2934 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2938 perf_event_sync_stat(ctx
, next_ctx
);
2940 raw_spin_unlock(&next_ctx
->lock
);
2941 raw_spin_unlock(&ctx
->lock
);
2947 raw_spin_lock(&ctx
->lock
);
2948 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
2949 raw_spin_unlock(&ctx
->lock
);
2953 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
2955 void perf_sched_cb_dec(struct pmu
*pmu
)
2957 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2959 this_cpu_dec(perf_sched_cb_usages
);
2961 if (!--cpuctx
->sched_cb_usage
)
2962 list_del(&cpuctx
->sched_cb_entry
);
2966 void perf_sched_cb_inc(struct pmu
*pmu
)
2968 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2970 if (!cpuctx
->sched_cb_usage
++)
2971 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
2973 this_cpu_inc(perf_sched_cb_usages
);
2977 * This function provides the context switch callback to the lower code
2978 * layer. It is invoked ONLY when the context switch callback is enabled.
2980 * This callback is relevant even to per-cpu events; for example multi event
2981 * PEBS requires this to provide PID/TID information. This requires we flush
2982 * all queued PEBS records before we context switch to a new task.
2984 static void perf_pmu_sched_task(struct task_struct
*prev
,
2985 struct task_struct
*next
,
2988 struct perf_cpu_context
*cpuctx
;
2994 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
2995 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
2997 if (WARN_ON_ONCE(!pmu
->sched_task
))
3000 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3001 perf_pmu_disable(pmu
);
3003 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3005 perf_pmu_enable(pmu
);
3006 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3010 static void perf_event_switch(struct task_struct
*task
,
3011 struct task_struct
*next_prev
, bool sched_in
);
3013 #define for_each_task_context_nr(ctxn) \
3014 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3017 * Called from scheduler to remove the events of the current task,
3018 * with interrupts disabled.
3020 * We stop each event and update the event value in event->count.
3022 * This does not protect us against NMI, but disable()
3023 * sets the disabled bit in the control field of event _before_
3024 * accessing the event control register. If a NMI hits, then it will
3025 * not restart the event.
3027 void __perf_event_task_sched_out(struct task_struct
*task
,
3028 struct task_struct
*next
)
3032 if (__this_cpu_read(perf_sched_cb_usages
))
3033 perf_pmu_sched_task(task
, next
, false);
3035 if (atomic_read(&nr_switch_events
))
3036 perf_event_switch(task
, next
, false);
3038 for_each_task_context_nr(ctxn
)
3039 perf_event_context_sched_out(task
, ctxn
, next
);
3042 * if cgroup events exist on this CPU, then we need
3043 * to check if we have to switch out PMU state.
3044 * cgroup event are system-wide mode only
3046 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3047 perf_cgroup_sched_out(task
, next
);
3051 * Called with IRQs disabled
3053 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3054 enum event_type_t event_type
)
3056 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3060 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3061 struct perf_cpu_context
*cpuctx
)
3063 struct perf_event
*event
;
3065 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
3066 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3068 if (!event_filter_match(event
))
3071 /* may need to reset tstamp_enabled */
3072 if (is_cgroup_event(event
))
3073 perf_cgroup_mark_enabled(event
, ctx
);
3075 if (group_can_go_on(event
, cpuctx
, 1))
3076 group_sched_in(event
, cpuctx
, ctx
);
3079 * If this pinned group hasn't been scheduled,
3080 * put it in error state.
3082 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3083 update_group_times(event
);
3084 event
->state
= PERF_EVENT_STATE_ERROR
;
3090 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3091 struct perf_cpu_context
*cpuctx
)
3093 struct perf_event
*event
;
3096 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3097 /* Ignore events in OFF or ERROR state */
3098 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3101 * Listen to the 'cpu' scheduling filter constraint
3104 if (!event_filter_match(event
))
3107 /* may need to reset tstamp_enabled */
3108 if (is_cgroup_event(event
))
3109 perf_cgroup_mark_enabled(event
, ctx
);
3111 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3112 if (group_sched_in(event
, cpuctx
, ctx
))
3119 ctx_sched_in(struct perf_event_context
*ctx
,
3120 struct perf_cpu_context
*cpuctx
,
3121 enum event_type_t event_type
,
3122 struct task_struct
*task
)
3124 int is_active
= ctx
->is_active
;
3127 lockdep_assert_held(&ctx
->lock
);
3129 if (likely(!ctx
->nr_events
))
3132 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3135 cpuctx
->task_ctx
= ctx
;
3137 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3140 is_active
^= ctx
->is_active
; /* changed bits */
3142 if (is_active
& EVENT_TIME
) {
3143 /* start ctx time */
3145 ctx
->timestamp
= now
;
3146 perf_cgroup_set_timestamp(task
, ctx
);
3150 * First go through the list and put on any pinned groups
3151 * in order to give them the best chance of going on.
3153 if (is_active
& EVENT_PINNED
)
3154 ctx_pinned_sched_in(ctx
, cpuctx
);
3156 /* Then walk through the lower prio flexible groups */
3157 if (is_active
& EVENT_FLEXIBLE
)
3158 ctx_flexible_sched_in(ctx
, cpuctx
);
3161 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3162 enum event_type_t event_type
,
3163 struct task_struct
*task
)
3165 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3167 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3170 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3171 struct task_struct
*task
)
3173 struct perf_cpu_context
*cpuctx
;
3175 cpuctx
= __get_cpu_context(ctx
);
3176 if (cpuctx
->task_ctx
== ctx
)
3179 perf_ctx_lock(cpuctx
, ctx
);
3180 perf_pmu_disable(ctx
->pmu
);
3182 * We want to keep the following priority order:
3183 * cpu pinned (that don't need to move), task pinned,
3184 * cpu flexible, task flexible.
3186 * However, if task's ctx is not carrying any pinned
3187 * events, no need to flip the cpuctx's events around.
3189 if (!list_empty(&ctx
->pinned_groups
))
3190 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3191 perf_event_sched_in(cpuctx
, ctx
, task
);
3192 perf_pmu_enable(ctx
->pmu
);
3193 perf_ctx_unlock(cpuctx
, ctx
);
3197 * Called from scheduler to add the events of the current task
3198 * with interrupts disabled.
3200 * We restore the event value and then enable it.
3202 * This does not protect us against NMI, but enable()
3203 * sets the enabled bit in the control field of event _before_
3204 * accessing the event control register. If a NMI hits, then it will
3205 * keep the event running.
3207 void __perf_event_task_sched_in(struct task_struct
*prev
,
3208 struct task_struct
*task
)
3210 struct perf_event_context
*ctx
;
3214 * If cgroup events exist on this CPU, then we need to check if we have
3215 * to switch in PMU state; cgroup event are system-wide mode only.
3217 * Since cgroup events are CPU events, we must schedule these in before
3218 * we schedule in the task events.
3220 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3221 perf_cgroup_sched_in(prev
, task
);
3223 for_each_task_context_nr(ctxn
) {
3224 ctx
= task
->perf_event_ctxp
[ctxn
];
3228 perf_event_context_sched_in(ctx
, task
);
3231 if (atomic_read(&nr_switch_events
))
3232 perf_event_switch(task
, prev
, true);
3234 if (__this_cpu_read(perf_sched_cb_usages
))
3235 perf_pmu_sched_task(prev
, task
, true);
3238 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3240 u64 frequency
= event
->attr
.sample_freq
;
3241 u64 sec
= NSEC_PER_SEC
;
3242 u64 divisor
, dividend
;
3244 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3246 count_fls
= fls64(count
);
3247 nsec_fls
= fls64(nsec
);
3248 frequency_fls
= fls64(frequency
);
3252 * We got @count in @nsec, with a target of sample_freq HZ
3253 * the target period becomes:
3256 * period = -------------------
3257 * @nsec * sample_freq
3262 * Reduce accuracy by one bit such that @a and @b converge
3263 * to a similar magnitude.
3265 #define REDUCE_FLS(a, b) \
3267 if (a##_fls > b##_fls) { \
3277 * Reduce accuracy until either term fits in a u64, then proceed with
3278 * the other, so that finally we can do a u64/u64 division.
3280 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3281 REDUCE_FLS(nsec
, frequency
);
3282 REDUCE_FLS(sec
, count
);
3285 if (count_fls
+ sec_fls
> 64) {
3286 divisor
= nsec
* frequency
;
3288 while (count_fls
+ sec_fls
> 64) {
3289 REDUCE_FLS(count
, sec
);
3293 dividend
= count
* sec
;
3295 dividend
= count
* sec
;
3297 while (nsec_fls
+ frequency_fls
> 64) {
3298 REDUCE_FLS(nsec
, frequency
);
3302 divisor
= nsec
* frequency
;
3308 return div64_u64(dividend
, divisor
);
3311 static DEFINE_PER_CPU(int, perf_throttled_count
);
3312 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3314 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3316 struct hw_perf_event
*hwc
= &event
->hw
;
3317 s64 period
, sample_period
;
3320 period
= perf_calculate_period(event
, nsec
, count
);
3322 delta
= (s64
)(period
- hwc
->sample_period
);
3323 delta
= (delta
+ 7) / 8; /* low pass filter */
3325 sample_period
= hwc
->sample_period
+ delta
;
3330 hwc
->sample_period
= sample_period
;
3332 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3334 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3336 local64_set(&hwc
->period_left
, 0);
3339 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3344 * combine freq adjustment with unthrottling to avoid two passes over the
3345 * events. At the same time, make sure, having freq events does not change
3346 * the rate of unthrottling as that would introduce bias.
3348 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3351 struct perf_event
*event
;
3352 struct hw_perf_event
*hwc
;
3353 u64 now
, period
= TICK_NSEC
;
3357 * only need to iterate over all events iff:
3358 * - context have events in frequency mode (needs freq adjust)
3359 * - there are events to unthrottle on this cpu
3361 if (!(ctx
->nr_freq
|| needs_unthr
))
3364 raw_spin_lock(&ctx
->lock
);
3365 perf_pmu_disable(ctx
->pmu
);
3367 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3368 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3371 if (!event_filter_match(event
))
3374 perf_pmu_disable(event
->pmu
);
3378 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3379 hwc
->interrupts
= 0;
3380 perf_log_throttle(event
, 1);
3381 event
->pmu
->start(event
, 0);
3384 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3388 * stop the event and update event->count
3390 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3392 now
= local64_read(&event
->count
);
3393 delta
= now
- hwc
->freq_count_stamp
;
3394 hwc
->freq_count_stamp
= now
;
3398 * reload only if value has changed
3399 * we have stopped the event so tell that
3400 * to perf_adjust_period() to avoid stopping it
3404 perf_adjust_period(event
, period
, delta
, false);
3406 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3408 perf_pmu_enable(event
->pmu
);
3411 perf_pmu_enable(ctx
->pmu
);
3412 raw_spin_unlock(&ctx
->lock
);
3416 * Round-robin a context's events:
3418 static void rotate_ctx(struct perf_event_context
*ctx
)
3421 * Rotate the first entry last of non-pinned groups. Rotation might be
3422 * disabled by the inheritance code.
3424 if (!ctx
->rotate_disable
)
3425 list_rotate_left(&ctx
->flexible_groups
);
3428 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3430 struct perf_event_context
*ctx
= NULL
;
3433 if (cpuctx
->ctx
.nr_events
) {
3434 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3438 ctx
= cpuctx
->task_ctx
;
3439 if (ctx
&& ctx
->nr_events
) {
3440 if (ctx
->nr_events
!= ctx
->nr_active
)
3447 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3448 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3450 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3452 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3454 rotate_ctx(&cpuctx
->ctx
);
3458 perf_event_sched_in(cpuctx
, ctx
, current
);
3460 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3461 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3467 void perf_event_task_tick(void)
3469 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3470 struct perf_event_context
*ctx
, *tmp
;
3473 WARN_ON(!irqs_disabled());
3475 __this_cpu_inc(perf_throttled_seq
);
3476 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3477 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3479 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3480 perf_adjust_freq_unthr_context(ctx
, throttled
);
3483 static int event_enable_on_exec(struct perf_event
*event
,
3484 struct perf_event_context
*ctx
)
3486 if (!event
->attr
.enable_on_exec
)
3489 event
->attr
.enable_on_exec
= 0;
3490 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3493 __perf_event_mark_enabled(event
);
3499 * Enable all of a task's events that have been marked enable-on-exec.
3500 * This expects task == current.
3502 static void perf_event_enable_on_exec(int ctxn
)
3504 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3505 enum event_type_t event_type
= 0;
3506 struct perf_cpu_context
*cpuctx
;
3507 struct perf_event
*event
;
3508 unsigned long flags
;
3511 local_irq_save(flags
);
3512 ctx
= current
->perf_event_ctxp
[ctxn
];
3513 if (!ctx
|| !ctx
->nr_events
)
3516 cpuctx
= __get_cpu_context(ctx
);
3517 perf_ctx_lock(cpuctx
, ctx
);
3518 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3519 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3520 enabled
|= event_enable_on_exec(event
, ctx
);
3521 event_type
|= get_event_type(event
);
3525 * Unclone and reschedule this context if we enabled any event.
3528 clone_ctx
= unclone_ctx(ctx
);
3529 ctx_resched(cpuctx
, ctx
, event_type
);
3531 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3533 perf_ctx_unlock(cpuctx
, ctx
);
3536 local_irq_restore(flags
);
3542 struct perf_read_data
{
3543 struct perf_event
*event
;
3548 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3550 u16 local_pkg
, event_pkg
;
3552 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3553 int local_cpu
= smp_processor_id();
3555 event_pkg
= topology_physical_package_id(event_cpu
);
3556 local_pkg
= topology_physical_package_id(local_cpu
);
3558 if (event_pkg
== local_pkg
)
3566 * Cross CPU call to read the hardware event
3568 static void __perf_event_read(void *info
)
3570 struct perf_read_data
*data
= info
;
3571 struct perf_event
*sub
, *event
= data
->event
;
3572 struct perf_event_context
*ctx
= event
->ctx
;
3573 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3574 struct pmu
*pmu
= event
->pmu
;
3577 * If this is a task context, we need to check whether it is
3578 * the current task context of this cpu. If not it has been
3579 * scheduled out before the smp call arrived. In that case
3580 * event->count would have been updated to a recent sample
3581 * when the event was scheduled out.
3583 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3586 raw_spin_lock(&ctx
->lock
);
3587 if (ctx
->is_active
) {
3588 update_context_time(ctx
);
3589 update_cgrp_time_from_event(event
);
3592 update_event_times(event
);
3593 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3602 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3606 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3607 update_event_times(sub
);
3608 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3610 * Use sibling's PMU rather than @event's since
3611 * sibling could be on different (eg: software) PMU.
3613 sub
->pmu
->read(sub
);
3617 data
->ret
= pmu
->commit_txn(pmu
);
3620 raw_spin_unlock(&ctx
->lock
);
3623 static inline u64
perf_event_count(struct perf_event
*event
)
3625 if (event
->pmu
->count
)
3626 return event
->pmu
->count(event
);
3628 return __perf_event_count(event
);
3632 * NMI-safe method to read a local event, that is an event that
3634 * - either for the current task, or for this CPU
3635 * - does not have inherit set, for inherited task events
3636 * will not be local and we cannot read them atomically
3637 * - must not have a pmu::count method
3639 u64
perf_event_read_local(struct perf_event
*event
)
3641 unsigned long flags
;
3645 * Disabling interrupts avoids all counter scheduling (context
3646 * switches, timer based rotation and IPIs).
3648 local_irq_save(flags
);
3650 /* If this is a per-task event, it must be for current */
3651 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3652 event
->hw
.target
!= current
);
3654 /* If this is a per-CPU event, it must be for this CPU */
3655 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3656 event
->cpu
!= smp_processor_id());
3659 * It must not be an event with inherit set, we cannot read
3660 * all child counters from atomic context.
3662 WARN_ON_ONCE(event
->attr
.inherit
);
3665 * It must not have a pmu::count method, those are not
3668 WARN_ON_ONCE(event
->pmu
->count
);
3671 * If the event is currently on this CPU, its either a per-task event,
3672 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3675 if (event
->oncpu
== smp_processor_id())
3676 event
->pmu
->read(event
);
3678 val
= local64_read(&event
->count
);
3679 local_irq_restore(flags
);
3684 static int perf_event_read(struct perf_event
*event
, bool group
)
3686 int event_cpu
, ret
= 0;
3689 * If event is enabled and currently active on a CPU, update the
3690 * value in the event structure:
3692 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3693 struct perf_read_data data
= {
3699 event_cpu
= READ_ONCE(event
->oncpu
);
3700 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3704 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
3707 * Purposely ignore the smp_call_function_single() return
3710 * If event_cpu isn't a valid CPU it means the event got
3711 * scheduled out and that will have updated the event count.
3713 * Therefore, either way, we'll have an up-to-date event count
3716 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
3719 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3720 struct perf_event_context
*ctx
= event
->ctx
;
3721 unsigned long flags
;
3723 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3725 * may read while context is not active
3726 * (e.g., thread is blocked), in that case
3727 * we cannot update context time
3729 if (ctx
->is_active
) {
3730 update_context_time(ctx
);
3731 update_cgrp_time_from_event(event
);
3734 update_group_times(event
);
3736 update_event_times(event
);
3737 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3744 * Initialize the perf_event context in a task_struct:
3746 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3748 raw_spin_lock_init(&ctx
->lock
);
3749 mutex_init(&ctx
->mutex
);
3750 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3751 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3752 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3753 INIT_LIST_HEAD(&ctx
->event_list
);
3754 atomic_set(&ctx
->refcount
, 1);
3757 static struct perf_event_context
*
3758 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3760 struct perf_event_context
*ctx
;
3762 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3766 __perf_event_init_context(ctx
);
3769 get_task_struct(task
);
3776 static struct task_struct
*
3777 find_lively_task_by_vpid(pid_t vpid
)
3779 struct task_struct
*task
;
3785 task
= find_task_by_vpid(vpid
);
3787 get_task_struct(task
);
3791 return ERR_PTR(-ESRCH
);
3797 * Returns a matching context with refcount and pincount.
3799 static struct perf_event_context
*
3800 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3801 struct perf_event
*event
)
3803 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3804 struct perf_cpu_context
*cpuctx
;
3805 void *task_ctx_data
= NULL
;
3806 unsigned long flags
;
3808 int cpu
= event
->cpu
;
3811 /* Must be root to operate on a CPU event: */
3812 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3813 return ERR_PTR(-EACCES
);
3816 * We could be clever and allow to attach a event to an
3817 * offline CPU and activate it when the CPU comes up, but
3820 if (!cpu_online(cpu
))
3821 return ERR_PTR(-ENODEV
);
3823 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3832 ctxn
= pmu
->task_ctx_nr
;
3836 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3837 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3838 if (!task_ctx_data
) {
3845 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3847 clone_ctx
= unclone_ctx(ctx
);
3850 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3851 ctx
->task_ctx_data
= task_ctx_data
;
3852 task_ctx_data
= NULL
;
3854 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3859 ctx
= alloc_perf_context(pmu
, task
);
3864 if (task_ctx_data
) {
3865 ctx
->task_ctx_data
= task_ctx_data
;
3866 task_ctx_data
= NULL
;
3870 mutex_lock(&task
->perf_event_mutex
);
3872 * If it has already passed perf_event_exit_task().
3873 * we must see PF_EXITING, it takes this mutex too.
3875 if (task
->flags
& PF_EXITING
)
3877 else if (task
->perf_event_ctxp
[ctxn
])
3882 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3884 mutex_unlock(&task
->perf_event_mutex
);
3886 if (unlikely(err
)) {
3895 kfree(task_ctx_data
);
3899 kfree(task_ctx_data
);
3900 return ERR_PTR(err
);
3903 static void perf_event_free_filter(struct perf_event
*event
);
3904 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3906 static void free_event_rcu(struct rcu_head
*head
)
3908 struct perf_event
*event
;
3910 event
= container_of(head
, struct perf_event
, rcu_head
);
3912 put_pid_ns(event
->ns
);
3913 perf_event_free_filter(event
);
3917 static void ring_buffer_attach(struct perf_event
*event
,
3918 struct ring_buffer
*rb
);
3920 static void detach_sb_event(struct perf_event
*event
)
3922 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3924 raw_spin_lock(&pel
->lock
);
3925 list_del_rcu(&event
->sb_list
);
3926 raw_spin_unlock(&pel
->lock
);
3929 static bool is_sb_event(struct perf_event
*event
)
3931 struct perf_event_attr
*attr
= &event
->attr
;
3936 if (event
->attach_state
& PERF_ATTACH_TASK
)
3939 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3940 attr
->comm
|| attr
->comm_exec
||
3942 attr
->context_switch
)
3947 static void unaccount_pmu_sb_event(struct perf_event
*event
)
3949 if (is_sb_event(event
))
3950 detach_sb_event(event
);
3953 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3958 if (is_cgroup_event(event
))
3959 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3962 #ifdef CONFIG_NO_HZ_FULL
3963 static DEFINE_SPINLOCK(nr_freq_lock
);
3966 static void unaccount_freq_event_nohz(void)
3968 #ifdef CONFIG_NO_HZ_FULL
3969 spin_lock(&nr_freq_lock
);
3970 if (atomic_dec_and_test(&nr_freq_events
))
3971 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3972 spin_unlock(&nr_freq_lock
);
3976 static void unaccount_freq_event(void)
3978 if (tick_nohz_full_enabled())
3979 unaccount_freq_event_nohz();
3981 atomic_dec(&nr_freq_events
);
3984 static void unaccount_event(struct perf_event
*event
)
3991 if (event
->attach_state
& PERF_ATTACH_TASK
)
3993 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3994 atomic_dec(&nr_mmap_events
);
3995 if (event
->attr
.comm
)
3996 atomic_dec(&nr_comm_events
);
3997 if (event
->attr
.namespaces
)
3998 atomic_dec(&nr_namespaces_events
);
3999 if (event
->attr
.task
)
4000 atomic_dec(&nr_task_events
);
4001 if (event
->attr
.freq
)
4002 unaccount_freq_event();
4003 if (event
->attr
.context_switch
) {
4005 atomic_dec(&nr_switch_events
);
4007 if (is_cgroup_event(event
))
4009 if (has_branch_stack(event
))
4013 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4014 schedule_delayed_work(&perf_sched_work
, HZ
);
4017 unaccount_event_cpu(event
, event
->cpu
);
4019 unaccount_pmu_sb_event(event
);
4022 static void perf_sched_delayed(struct work_struct
*work
)
4024 mutex_lock(&perf_sched_mutex
);
4025 if (atomic_dec_and_test(&perf_sched_count
))
4026 static_branch_disable(&perf_sched_events
);
4027 mutex_unlock(&perf_sched_mutex
);
4031 * The following implement mutual exclusion of events on "exclusive" pmus
4032 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4033 * at a time, so we disallow creating events that might conflict, namely:
4035 * 1) cpu-wide events in the presence of per-task events,
4036 * 2) per-task events in the presence of cpu-wide events,
4037 * 3) two matching events on the same context.
4039 * The former two cases are handled in the allocation path (perf_event_alloc(),
4040 * _free_event()), the latter -- before the first perf_install_in_context().
4042 static int exclusive_event_init(struct perf_event
*event
)
4044 struct pmu
*pmu
= event
->pmu
;
4046 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4050 * Prevent co-existence of per-task and cpu-wide events on the
4051 * same exclusive pmu.
4053 * Negative pmu::exclusive_cnt means there are cpu-wide
4054 * events on this "exclusive" pmu, positive means there are
4057 * Since this is called in perf_event_alloc() path, event::ctx
4058 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4059 * to mean "per-task event", because unlike other attach states it
4060 * never gets cleared.
4062 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4063 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4066 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4073 static void exclusive_event_destroy(struct perf_event
*event
)
4075 struct pmu
*pmu
= event
->pmu
;
4077 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4080 /* see comment in exclusive_event_init() */
4081 if (event
->attach_state
& PERF_ATTACH_TASK
)
4082 atomic_dec(&pmu
->exclusive_cnt
);
4084 atomic_inc(&pmu
->exclusive_cnt
);
4087 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4089 if ((e1
->pmu
== e2
->pmu
) &&
4090 (e1
->cpu
== e2
->cpu
||
4097 /* Called under the same ctx::mutex as perf_install_in_context() */
4098 static bool exclusive_event_installable(struct perf_event
*event
,
4099 struct perf_event_context
*ctx
)
4101 struct perf_event
*iter_event
;
4102 struct pmu
*pmu
= event
->pmu
;
4104 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4107 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4108 if (exclusive_event_match(iter_event
, event
))
4115 static void perf_addr_filters_splice(struct perf_event
*event
,
4116 struct list_head
*head
);
4118 static void _free_event(struct perf_event
*event
)
4120 irq_work_sync(&event
->pending
);
4122 unaccount_event(event
);
4126 * Can happen when we close an event with re-directed output.
4128 * Since we have a 0 refcount, perf_mmap_close() will skip
4129 * over us; possibly making our ring_buffer_put() the last.
4131 mutex_lock(&event
->mmap_mutex
);
4132 ring_buffer_attach(event
, NULL
);
4133 mutex_unlock(&event
->mmap_mutex
);
4136 if (is_cgroup_event(event
))
4137 perf_detach_cgroup(event
);
4139 if (!event
->parent
) {
4140 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4141 put_callchain_buffers();
4144 perf_event_free_bpf_prog(event
);
4145 perf_addr_filters_splice(event
, NULL
);
4146 kfree(event
->addr_filters_offs
);
4149 event
->destroy(event
);
4152 put_ctx(event
->ctx
);
4154 exclusive_event_destroy(event
);
4155 module_put(event
->pmu
->module
);
4157 call_rcu(&event
->rcu_head
, free_event_rcu
);
4161 * Used to free events which have a known refcount of 1, such as in error paths
4162 * where the event isn't exposed yet and inherited events.
4164 static void free_event(struct perf_event
*event
)
4166 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4167 "unexpected event refcount: %ld; ptr=%p\n",
4168 atomic_long_read(&event
->refcount
), event
)) {
4169 /* leak to avoid use-after-free */
4177 * Remove user event from the owner task.
4179 static void perf_remove_from_owner(struct perf_event
*event
)
4181 struct task_struct
*owner
;
4185 * Matches the smp_store_release() in perf_event_exit_task(). If we
4186 * observe !owner it means the list deletion is complete and we can
4187 * indeed free this event, otherwise we need to serialize on
4188 * owner->perf_event_mutex.
4190 owner
= lockless_dereference(event
->owner
);
4193 * Since delayed_put_task_struct() also drops the last
4194 * task reference we can safely take a new reference
4195 * while holding the rcu_read_lock().
4197 get_task_struct(owner
);
4203 * If we're here through perf_event_exit_task() we're already
4204 * holding ctx->mutex which would be an inversion wrt. the
4205 * normal lock order.
4207 * However we can safely take this lock because its the child
4210 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4213 * We have to re-check the event->owner field, if it is cleared
4214 * we raced with perf_event_exit_task(), acquiring the mutex
4215 * ensured they're done, and we can proceed with freeing the
4219 list_del_init(&event
->owner_entry
);
4220 smp_store_release(&event
->owner
, NULL
);
4222 mutex_unlock(&owner
->perf_event_mutex
);
4223 put_task_struct(owner
);
4227 static void put_event(struct perf_event
*event
)
4229 if (!atomic_long_dec_and_test(&event
->refcount
))
4236 * Kill an event dead; while event:refcount will preserve the event
4237 * object, it will not preserve its functionality. Once the last 'user'
4238 * gives up the object, we'll destroy the thing.
4240 int perf_event_release_kernel(struct perf_event
*event
)
4242 struct perf_event_context
*ctx
= event
->ctx
;
4243 struct perf_event
*child
, *tmp
;
4246 * If we got here through err_file: fput(event_file); we will not have
4247 * attached to a context yet.
4250 WARN_ON_ONCE(event
->attach_state
&
4251 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4255 if (!is_kernel_event(event
))
4256 perf_remove_from_owner(event
);
4258 ctx
= perf_event_ctx_lock(event
);
4259 WARN_ON_ONCE(ctx
->parent_ctx
);
4260 perf_remove_from_context(event
, DETACH_GROUP
);
4262 raw_spin_lock_irq(&ctx
->lock
);
4264 * Mark this event as STATE_DEAD, there is no external reference to it
4267 * Anybody acquiring event->child_mutex after the below loop _must_
4268 * also see this, most importantly inherit_event() which will avoid
4269 * placing more children on the list.
4271 * Thus this guarantees that we will in fact observe and kill _ALL_
4274 event
->state
= PERF_EVENT_STATE_DEAD
;
4275 raw_spin_unlock_irq(&ctx
->lock
);
4277 perf_event_ctx_unlock(event
, ctx
);
4280 mutex_lock(&event
->child_mutex
);
4281 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4284 * Cannot change, child events are not migrated, see the
4285 * comment with perf_event_ctx_lock_nested().
4287 ctx
= lockless_dereference(child
->ctx
);
4289 * Since child_mutex nests inside ctx::mutex, we must jump
4290 * through hoops. We start by grabbing a reference on the ctx.
4292 * Since the event cannot get freed while we hold the
4293 * child_mutex, the context must also exist and have a !0
4299 * Now that we have a ctx ref, we can drop child_mutex, and
4300 * acquire ctx::mutex without fear of it going away. Then we
4301 * can re-acquire child_mutex.
4303 mutex_unlock(&event
->child_mutex
);
4304 mutex_lock(&ctx
->mutex
);
4305 mutex_lock(&event
->child_mutex
);
4308 * Now that we hold ctx::mutex and child_mutex, revalidate our
4309 * state, if child is still the first entry, it didn't get freed
4310 * and we can continue doing so.
4312 tmp
= list_first_entry_or_null(&event
->child_list
,
4313 struct perf_event
, child_list
);
4315 perf_remove_from_context(child
, DETACH_GROUP
);
4316 list_del(&child
->child_list
);
4319 * This matches the refcount bump in inherit_event();
4320 * this can't be the last reference.
4325 mutex_unlock(&event
->child_mutex
);
4326 mutex_unlock(&ctx
->mutex
);
4330 mutex_unlock(&event
->child_mutex
);
4333 put_event(event
); /* Must be the 'last' reference */
4336 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4339 * Called when the last reference to the file is gone.
4341 static int perf_release(struct inode
*inode
, struct file
*file
)
4343 perf_event_release_kernel(file
->private_data
);
4347 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4349 struct perf_event
*child
;
4355 mutex_lock(&event
->child_mutex
);
4357 (void)perf_event_read(event
, false);
4358 total
+= perf_event_count(event
);
4360 *enabled
+= event
->total_time_enabled
+
4361 atomic64_read(&event
->child_total_time_enabled
);
4362 *running
+= event
->total_time_running
+
4363 atomic64_read(&event
->child_total_time_running
);
4365 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4366 (void)perf_event_read(child
, false);
4367 total
+= perf_event_count(child
);
4368 *enabled
+= child
->total_time_enabled
;
4369 *running
+= child
->total_time_running
;
4371 mutex_unlock(&event
->child_mutex
);
4375 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4377 static int __perf_read_group_add(struct perf_event
*leader
,
4378 u64 read_format
, u64
*values
)
4380 struct perf_event
*sub
;
4381 int n
= 1; /* skip @nr */
4384 ret
= perf_event_read(leader
, true);
4389 * Since we co-schedule groups, {enabled,running} times of siblings
4390 * will be identical to those of the leader, so we only publish one
4393 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4394 values
[n
++] += leader
->total_time_enabled
+
4395 atomic64_read(&leader
->child_total_time_enabled
);
4398 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4399 values
[n
++] += leader
->total_time_running
+
4400 atomic64_read(&leader
->child_total_time_running
);
4404 * Write {count,id} tuples for every sibling.
4406 values
[n
++] += perf_event_count(leader
);
4407 if (read_format
& PERF_FORMAT_ID
)
4408 values
[n
++] = primary_event_id(leader
);
4410 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4411 values
[n
++] += perf_event_count(sub
);
4412 if (read_format
& PERF_FORMAT_ID
)
4413 values
[n
++] = primary_event_id(sub
);
4419 static int perf_read_group(struct perf_event
*event
,
4420 u64 read_format
, char __user
*buf
)
4422 struct perf_event
*leader
= event
->group_leader
, *child
;
4423 struct perf_event_context
*ctx
= leader
->ctx
;
4427 lockdep_assert_held(&ctx
->mutex
);
4429 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4433 values
[0] = 1 + leader
->nr_siblings
;
4436 * By locking the child_mutex of the leader we effectively
4437 * lock the child list of all siblings.. XXX explain how.
4439 mutex_lock(&leader
->child_mutex
);
4441 ret
= __perf_read_group_add(leader
, read_format
, values
);
4445 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4446 ret
= __perf_read_group_add(child
, read_format
, values
);
4451 mutex_unlock(&leader
->child_mutex
);
4453 ret
= event
->read_size
;
4454 if (copy_to_user(buf
, values
, event
->read_size
))
4459 mutex_unlock(&leader
->child_mutex
);
4465 static int perf_read_one(struct perf_event
*event
,
4466 u64 read_format
, char __user
*buf
)
4468 u64 enabled
, running
;
4472 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4473 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4474 values
[n
++] = enabled
;
4475 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4476 values
[n
++] = running
;
4477 if (read_format
& PERF_FORMAT_ID
)
4478 values
[n
++] = primary_event_id(event
);
4480 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4483 return n
* sizeof(u64
);
4486 static bool is_event_hup(struct perf_event
*event
)
4490 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4493 mutex_lock(&event
->child_mutex
);
4494 no_children
= list_empty(&event
->child_list
);
4495 mutex_unlock(&event
->child_mutex
);
4500 * Read the performance event - simple non blocking version for now
4503 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4505 u64 read_format
= event
->attr
.read_format
;
4509 * Return end-of-file for a read on a event that is in
4510 * error state (i.e. because it was pinned but it couldn't be
4511 * scheduled on to the CPU at some point).
4513 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4516 if (count
< event
->read_size
)
4519 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4520 if (read_format
& PERF_FORMAT_GROUP
)
4521 ret
= perf_read_group(event
, read_format
, buf
);
4523 ret
= perf_read_one(event
, read_format
, buf
);
4529 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4531 struct perf_event
*event
= file
->private_data
;
4532 struct perf_event_context
*ctx
;
4535 ctx
= perf_event_ctx_lock(event
);
4536 ret
= __perf_read(event
, buf
, count
);
4537 perf_event_ctx_unlock(event
, ctx
);
4542 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4544 struct perf_event
*event
= file
->private_data
;
4545 struct ring_buffer
*rb
;
4546 unsigned int events
= POLLHUP
;
4548 poll_wait(file
, &event
->waitq
, wait
);
4550 if (is_event_hup(event
))
4554 * Pin the event->rb by taking event->mmap_mutex; otherwise
4555 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4557 mutex_lock(&event
->mmap_mutex
);
4560 events
= atomic_xchg(&rb
->poll
, 0);
4561 mutex_unlock(&event
->mmap_mutex
);
4565 static void _perf_event_reset(struct perf_event
*event
)
4567 (void)perf_event_read(event
, false);
4568 local64_set(&event
->count
, 0);
4569 perf_event_update_userpage(event
);
4573 * Holding the top-level event's child_mutex means that any
4574 * descendant process that has inherited this event will block
4575 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4576 * task existence requirements of perf_event_enable/disable.
4578 static void perf_event_for_each_child(struct perf_event
*event
,
4579 void (*func
)(struct perf_event
*))
4581 struct perf_event
*child
;
4583 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4585 mutex_lock(&event
->child_mutex
);
4587 list_for_each_entry(child
, &event
->child_list
, child_list
)
4589 mutex_unlock(&event
->child_mutex
);
4592 static void perf_event_for_each(struct perf_event
*event
,
4593 void (*func
)(struct perf_event
*))
4595 struct perf_event_context
*ctx
= event
->ctx
;
4596 struct perf_event
*sibling
;
4598 lockdep_assert_held(&ctx
->mutex
);
4600 event
= event
->group_leader
;
4602 perf_event_for_each_child(event
, func
);
4603 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4604 perf_event_for_each_child(sibling
, func
);
4607 static void __perf_event_period(struct perf_event
*event
,
4608 struct perf_cpu_context
*cpuctx
,
4609 struct perf_event_context
*ctx
,
4612 u64 value
= *((u64
*)info
);
4615 if (event
->attr
.freq
) {
4616 event
->attr
.sample_freq
= value
;
4618 event
->attr
.sample_period
= value
;
4619 event
->hw
.sample_period
= value
;
4622 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4624 perf_pmu_disable(ctx
->pmu
);
4626 * We could be throttled; unthrottle now to avoid the tick
4627 * trying to unthrottle while we already re-started the event.
4629 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4630 event
->hw
.interrupts
= 0;
4631 perf_log_throttle(event
, 1);
4633 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4636 local64_set(&event
->hw
.period_left
, 0);
4639 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4640 perf_pmu_enable(ctx
->pmu
);
4644 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4648 if (!is_sampling_event(event
))
4651 if (copy_from_user(&value
, arg
, sizeof(value
)))
4657 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4660 event_function_call(event
, __perf_event_period
, &value
);
4665 static const struct file_operations perf_fops
;
4667 static inline int perf_fget_light(int fd
, struct fd
*p
)
4669 struct fd f
= fdget(fd
);
4673 if (f
.file
->f_op
!= &perf_fops
) {
4681 static int perf_event_set_output(struct perf_event
*event
,
4682 struct perf_event
*output_event
);
4683 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4684 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4686 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4688 void (*func
)(struct perf_event
*);
4692 case PERF_EVENT_IOC_ENABLE
:
4693 func
= _perf_event_enable
;
4695 case PERF_EVENT_IOC_DISABLE
:
4696 func
= _perf_event_disable
;
4698 case PERF_EVENT_IOC_RESET
:
4699 func
= _perf_event_reset
;
4702 case PERF_EVENT_IOC_REFRESH
:
4703 return _perf_event_refresh(event
, arg
);
4705 case PERF_EVENT_IOC_PERIOD
:
4706 return perf_event_period(event
, (u64 __user
*)arg
);
4708 case PERF_EVENT_IOC_ID
:
4710 u64 id
= primary_event_id(event
);
4712 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4717 case PERF_EVENT_IOC_SET_OUTPUT
:
4721 struct perf_event
*output_event
;
4723 ret
= perf_fget_light(arg
, &output
);
4726 output_event
= output
.file
->private_data
;
4727 ret
= perf_event_set_output(event
, output_event
);
4730 ret
= perf_event_set_output(event
, NULL
);
4735 case PERF_EVENT_IOC_SET_FILTER
:
4736 return perf_event_set_filter(event
, (void __user
*)arg
);
4738 case PERF_EVENT_IOC_SET_BPF
:
4739 return perf_event_set_bpf_prog(event
, arg
);
4741 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4742 struct ring_buffer
*rb
;
4745 rb
= rcu_dereference(event
->rb
);
4746 if (!rb
|| !rb
->nr_pages
) {
4750 rb_toggle_paused(rb
, !!arg
);
4758 if (flags
& PERF_IOC_FLAG_GROUP
)
4759 perf_event_for_each(event
, func
);
4761 perf_event_for_each_child(event
, func
);
4766 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4768 struct perf_event
*event
= file
->private_data
;
4769 struct perf_event_context
*ctx
;
4772 ctx
= perf_event_ctx_lock(event
);
4773 ret
= _perf_ioctl(event
, cmd
, arg
);
4774 perf_event_ctx_unlock(event
, ctx
);
4779 #ifdef CONFIG_COMPAT
4780 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4783 switch (_IOC_NR(cmd
)) {
4784 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4785 case _IOC_NR(PERF_EVENT_IOC_ID
):
4786 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4787 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4788 cmd
&= ~IOCSIZE_MASK
;
4789 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4793 return perf_ioctl(file
, cmd
, arg
);
4796 # define perf_compat_ioctl NULL
4799 int perf_event_task_enable(void)
4801 struct perf_event_context
*ctx
;
4802 struct perf_event
*event
;
4804 mutex_lock(¤t
->perf_event_mutex
);
4805 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4806 ctx
= perf_event_ctx_lock(event
);
4807 perf_event_for_each_child(event
, _perf_event_enable
);
4808 perf_event_ctx_unlock(event
, ctx
);
4810 mutex_unlock(¤t
->perf_event_mutex
);
4815 int perf_event_task_disable(void)
4817 struct perf_event_context
*ctx
;
4818 struct perf_event
*event
;
4820 mutex_lock(¤t
->perf_event_mutex
);
4821 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4822 ctx
= perf_event_ctx_lock(event
);
4823 perf_event_for_each_child(event
, _perf_event_disable
);
4824 perf_event_ctx_unlock(event
, ctx
);
4826 mutex_unlock(¤t
->perf_event_mutex
);
4831 static int perf_event_index(struct perf_event
*event
)
4833 if (event
->hw
.state
& PERF_HES_STOPPED
)
4836 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4839 return event
->pmu
->event_idx(event
);
4842 static void calc_timer_values(struct perf_event
*event
,
4849 *now
= perf_clock();
4850 ctx_time
= event
->shadow_ctx_time
+ *now
;
4851 *enabled
= ctx_time
- event
->tstamp_enabled
;
4852 *running
= ctx_time
- event
->tstamp_running
;
4855 static void perf_event_init_userpage(struct perf_event
*event
)
4857 struct perf_event_mmap_page
*userpg
;
4858 struct ring_buffer
*rb
;
4861 rb
= rcu_dereference(event
->rb
);
4865 userpg
= rb
->user_page
;
4867 /* Allow new userspace to detect that bit 0 is deprecated */
4868 userpg
->cap_bit0_is_deprecated
= 1;
4869 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4870 userpg
->data_offset
= PAGE_SIZE
;
4871 userpg
->data_size
= perf_data_size(rb
);
4877 void __weak
arch_perf_update_userpage(
4878 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4883 * Callers need to ensure there can be no nesting of this function, otherwise
4884 * the seqlock logic goes bad. We can not serialize this because the arch
4885 * code calls this from NMI context.
4887 void perf_event_update_userpage(struct perf_event
*event
)
4889 struct perf_event_mmap_page
*userpg
;
4890 struct ring_buffer
*rb
;
4891 u64 enabled
, running
, now
;
4894 rb
= rcu_dereference(event
->rb
);
4899 * compute total_time_enabled, total_time_running
4900 * based on snapshot values taken when the event
4901 * was last scheduled in.
4903 * we cannot simply called update_context_time()
4904 * because of locking issue as we can be called in
4907 calc_timer_values(event
, &now
, &enabled
, &running
);
4909 userpg
= rb
->user_page
;
4911 * Disable preemption so as to not let the corresponding user-space
4912 * spin too long if we get preempted.
4917 userpg
->index
= perf_event_index(event
);
4918 userpg
->offset
= perf_event_count(event
);
4920 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4922 userpg
->time_enabled
= enabled
+
4923 atomic64_read(&event
->child_total_time_enabled
);
4925 userpg
->time_running
= running
+
4926 atomic64_read(&event
->child_total_time_running
);
4928 arch_perf_update_userpage(event
, userpg
, now
);
4937 static int perf_mmap_fault(struct vm_fault
*vmf
)
4939 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
4940 struct ring_buffer
*rb
;
4941 int ret
= VM_FAULT_SIGBUS
;
4943 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4944 if (vmf
->pgoff
== 0)
4950 rb
= rcu_dereference(event
->rb
);
4954 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4957 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4961 get_page(vmf
->page
);
4962 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
4963 vmf
->page
->index
= vmf
->pgoff
;
4972 static void ring_buffer_attach(struct perf_event
*event
,
4973 struct ring_buffer
*rb
)
4975 struct ring_buffer
*old_rb
= NULL
;
4976 unsigned long flags
;
4980 * Should be impossible, we set this when removing
4981 * event->rb_entry and wait/clear when adding event->rb_entry.
4983 WARN_ON_ONCE(event
->rcu_pending
);
4986 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4987 list_del_rcu(&event
->rb_entry
);
4988 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4990 event
->rcu_batches
= get_state_synchronize_rcu();
4991 event
->rcu_pending
= 1;
4995 if (event
->rcu_pending
) {
4996 cond_synchronize_rcu(event
->rcu_batches
);
4997 event
->rcu_pending
= 0;
5000 spin_lock_irqsave(&rb
->event_lock
, flags
);
5001 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5002 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5006 * Avoid racing with perf_mmap_close(AUX): stop the event
5007 * before swizzling the event::rb pointer; if it's getting
5008 * unmapped, its aux_mmap_count will be 0 and it won't
5009 * restart. See the comment in __perf_pmu_output_stop().
5011 * Data will inevitably be lost when set_output is done in
5012 * mid-air, but then again, whoever does it like this is
5013 * not in for the data anyway.
5016 perf_event_stop(event
, 0);
5018 rcu_assign_pointer(event
->rb
, rb
);
5021 ring_buffer_put(old_rb
);
5023 * Since we detached before setting the new rb, so that we
5024 * could attach the new rb, we could have missed a wakeup.
5027 wake_up_all(&event
->waitq
);
5031 static void ring_buffer_wakeup(struct perf_event
*event
)
5033 struct ring_buffer
*rb
;
5036 rb
= rcu_dereference(event
->rb
);
5038 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5039 wake_up_all(&event
->waitq
);
5044 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5046 struct ring_buffer
*rb
;
5049 rb
= rcu_dereference(event
->rb
);
5051 if (!atomic_inc_not_zero(&rb
->refcount
))
5059 void ring_buffer_put(struct ring_buffer
*rb
)
5061 if (!atomic_dec_and_test(&rb
->refcount
))
5064 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5066 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5069 static void perf_mmap_open(struct vm_area_struct
*vma
)
5071 struct perf_event
*event
= vma
->vm_file
->private_data
;
5073 atomic_inc(&event
->mmap_count
);
5074 atomic_inc(&event
->rb
->mmap_count
);
5077 atomic_inc(&event
->rb
->aux_mmap_count
);
5079 if (event
->pmu
->event_mapped
)
5080 event
->pmu
->event_mapped(event
);
5083 static void perf_pmu_output_stop(struct perf_event
*event
);
5086 * A buffer can be mmap()ed multiple times; either directly through the same
5087 * event, or through other events by use of perf_event_set_output().
5089 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5090 * the buffer here, where we still have a VM context. This means we need
5091 * to detach all events redirecting to us.
5093 static void perf_mmap_close(struct vm_area_struct
*vma
)
5095 struct perf_event
*event
= vma
->vm_file
->private_data
;
5097 struct ring_buffer
*rb
= ring_buffer_get(event
);
5098 struct user_struct
*mmap_user
= rb
->mmap_user
;
5099 int mmap_locked
= rb
->mmap_locked
;
5100 unsigned long size
= perf_data_size(rb
);
5102 if (event
->pmu
->event_unmapped
)
5103 event
->pmu
->event_unmapped(event
);
5106 * rb->aux_mmap_count will always drop before rb->mmap_count and
5107 * event->mmap_count, so it is ok to use event->mmap_mutex to
5108 * serialize with perf_mmap here.
5110 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5111 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5113 * Stop all AUX events that are writing to this buffer,
5114 * so that we can free its AUX pages and corresponding PMU
5115 * data. Note that after rb::aux_mmap_count dropped to zero,
5116 * they won't start any more (see perf_aux_output_begin()).
5118 perf_pmu_output_stop(event
);
5120 /* now it's safe to free the pages */
5121 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5122 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5124 /* this has to be the last one */
5126 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5128 mutex_unlock(&event
->mmap_mutex
);
5131 atomic_dec(&rb
->mmap_count
);
5133 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5136 ring_buffer_attach(event
, NULL
);
5137 mutex_unlock(&event
->mmap_mutex
);
5139 /* If there's still other mmap()s of this buffer, we're done. */
5140 if (atomic_read(&rb
->mmap_count
))
5144 * No other mmap()s, detach from all other events that might redirect
5145 * into the now unreachable buffer. Somewhat complicated by the
5146 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5150 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5151 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5153 * This event is en-route to free_event() which will
5154 * detach it and remove it from the list.
5160 mutex_lock(&event
->mmap_mutex
);
5162 * Check we didn't race with perf_event_set_output() which can
5163 * swizzle the rb from under us while we were waiting to
5164 * acquire mmap_mutex.
5166 * If we find a different rb; ignore this event, a next
5167 * iteration will no longer find it on the list. We have to
5168 * still restart the iteration to make sure we're not now
5169 * iterating the wrong list.
5171 if (event
->rb
== rb
)
5172 ring_buffer_attach(event
, NULL
);
5174 mutex_unlock(&event
->mmap_mutex
);
5178 * Restart the iteration; either we're on the wrong list or
5179 * destroyed its integrity by doing a deletion.
5186 * It could be there's still a few 0-ref events on the list; they'll
5187 * get cleaned up by free_event() -- they'll also still have their
5188 * ref on the rb and will free it whenever they are done with it.
5190 * Aside from that, this buffer is 'fully' detached and unmapped,
5191 * undo the VM accounting.
5194 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5195 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5196 free_uid(mmap_user
);
5199 ring_buffer_put(rb
); /* could be last */
5202 static const struct vm_operations_struct perf_mmap_vmops
= {
5203 .open
= perf_mmap_open
,
5204 .close
= perf_mmap_close
, /* non mergable */
5205 .fault
= perf_mmap_fault
,
5206 .page_mkwrite
= perf_mmap_fault
,
5209 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5211 struct perf_event
*event
= file
->private_data
;
5212 unsigned long user_locked
, user_lock_limit
;
5213 struct user_struct
*user
= current_user();
5214 unsigned long locked
, lock_limit
;
5215 struct ring_buffer
*rb
= NULL
;
5216 unsigned long vma_size
;
5217 unsigned long nr_pages
;
5218 long user_extra
= 0, extra
= 0;
5219 int ret
= 0, flags
= 0;
5222 * Don't allow mmap() of inherited per-task counters. This would
5223 * create a performance issue due to all children writing to the
5226 if (event
->cpu
== -1 && event
->attr
.inherit
)
5229 if (!(vma
->vm_flags
& VM_SHARED
))
5232 vma_size
= vma
->vm_end
- vma
->vm_start
;
5234 if (vma
->vm_pgoff
== 0) {
5235 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5238 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5239 * mapped, all subsequent mappings should have the same size
5240 * and offset. Must be above the normal perf buffer.
5242 u64 aux_offset
, aux_size
;
5247 nr_pages
= vma_size
/ PAGE_SIZE
;
5249 mutex_lock(&event
->mmap_mutex
);
5256 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
5257 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
5259 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5262 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5265 /* already mapped with a different offset */
5266 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5269 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5272 /* already mapped with a different size */
5273 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5276 if (!is_power_of_2(nr_pages
))
5279 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5282 if (rb_has_aux(rb
)) {
5283 atomic_inc(&rb
->aux_mmap_count
);
5288 atomic_set(&rb
->aux_mmap_count
, 1);
5289 user_extra
= nr_pages
;
5295 * If we have rb pages ensure they're a power-of-two number, so we
5296 * can do bitmasks instead of modulo.
5298 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5301 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5304 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5306 mutex_lock(&event
->mmap_mutex
);
5308 if (event
->rb
->nr_pages
!= nr_pages
) {
5313 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5315 * Raced against perf_mmap_close() through
5316 * perf_event_set_output(). Try again, hope for better
5319 mutex_unlock(&event
->mmap_mutex
);
5326 user_extra
= nr_pages
+ 1;
5329 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5332 * Increase the limit linearly with more CPUs:
5334 user_lock_limit
*= num_online_cpus();
5336 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5338 if (user_locked
> user_lock_limit
)
5339 extra
= user_locked
- user_lock_limit
;
5341 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5342 lock_limit
>>= PAGE_SHIFT
;
5343 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5345 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5346 !capable(CAP_IPC_LOCK
)) {
5351 WARN_ON(!rb
&& event
->rb
);
5353 if (vma
->vm_flags
& VM_WRITE
)
5354 flags
|= RING_BUFFER_WRITABLE
;
5357 rb
= rb_alloc(nr_pages
,
5358 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5366 atomic_set(&rb
->mmap_count
, 1);
5367 rb
->mmap_user
= get_current_user();
5368 rb
->mmap_locked
= extra
;
5370 ring_buffer_attach(event
, rb
);
5372 perf_event_init_userpage(event
);
5373 perf_event_update_userpage(event
);
5375 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5376 event
->attr
.aux_watermark
, flags
);
5378 rb
->aux_mmap_locked
= extra
;
5383 atomic_long_add(user_extra
, &user
->locked_vm
);
5384 vma
->vm_mm
->pinned_vm
+= extra
;
5386 atomic_inc(&event
->mmap_count
);
5388 atomic_dec(&rb
->mmap_count
);
5391 mutex_unlock(&event
->mmap_mutex
);
5394 * Since pinned accounting is per vm we cannot allow fork() to copy our
5397 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5398 vma
->vm_ops
= &perf_mmap_vmops
;
5400 if (event
->pmu
->event_mapped
)
5401 event
->pmu
->event_mapped(event
);
5406 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5408 struct inode
*inode
= file_inode(filp
);
5409 struct perf_event
*event
= filp
->private_data
;
5413 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5414 inode_unlock(inode
);
5422 static const struct file_operations perf_fops
= {
5423 .llseek
= no_llseek
,
5424 .release
= perf_release
,
5427 .unlocked_ioctl
= perf_ioctl
,
5428 .compat_ioctl
= perf_compat_ioctl
,
5430 .fasync
= perf_fasync
,
5436 * If there's data, ensure we set the poll() state and publish everything
5437 * to user-space before waking everybody up.
5440 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5442 /* only the parent has fasync state */
5444 event
= event
->parent
;
5445 return &event
->fasync
;
5448 void perf_event_wakeup(struct perf_event
*event
)
5450 ring_buffer_wakeup(event
);
5452 if (event
->pending_kill
) {
5453 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5454 event
->pending_kill
= 0;
5458 static void perf_pending_event(struct irq_work
*entry
)
5460 struct perf_event
*event
= container_of(entry
,
5461 struct perf_event
, pending
);
5464 rctx
= perf_swevent_get_recursion_context();
5466 * If we 'fail' here, that's OK, it means recursion is already disabled
5467 * and we won't recurse 'further'.
5470 if (event
->pending_disable
) {
5471 event
->pending_disable
= 0;
5472 perf_event_disable_local(event
);
5475 if (event
->pending_wakeup
) {
5476 event
->pending_wakeup
= 0;
5477 perf_event_wakeup(event
);
5481 perf_swevent_put_recursion_context(rctx
);
5485 * We assume there is only KVM supporting the callbacks.
5486 * Later on, we might change it to a list if there is
5487 * another virtualization implementation supporting the callbacks.
5489 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5491 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5493 perf_guest_cbs
= cbs
;
5496 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5498 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5500 perf_guest_cbs
= NULL
;
5503 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5506 perf_output_sample_regs(struct perf_output_handle
*handle
,
5507 struct pt_regs
*regs
, u64 mask
)
5510 DECLARE_BITMAP(_mask
, 64);
5512 bitmap_from_u64(_mask
, mask
);
5513 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5516 val
= perf_reg_value(regs
, bit
);
5517 perf_output_put(handle
, val
);
5521 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5522 struct pt_regs
*regs
,
5523 struct pt_regs
*regs_user_copy
)
5525 if (user_mode(regs
)) {
5526 regs_user
->abi
= perf_reg_abi(current
);
5527 regs_user
->regs
= regs
;
5528 } else if (current
->mm
) {
5529 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5531 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5532 regs_user
->regs
= NULL
;
5536 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5537 struct pt_regs
*regs
)
5539 regs_intr
->regs
= regs
;
5540 regs_intr
->abi
= perf_reg_abi(current
);
5545 * Get remaining task size from user stack pointer.
5547 * It'd be better to take stack vma map and limit this more
5548 * precisly, but there's no way to get it safely under interrupt,
5549 * so using TASK_SIZE as limit.
5551 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5553 unsigned long addr
= perf_user_stack_pointer(regs
);
5555 if (!addr
|| addr
>= TASK_SIZE
)
5558 return TASK_SIZE
- addr
;
5562 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5563 struct pt_regs
*regs
)
5567 /* No regs, no stack pointer, no dump. */
5572 * Check if we fit in with the requested stack size into the:
5574 * If we don't, we limit the size to the TASK_SIZE.
5576 * - remaining sample size
5577 * If we don't, we customize the stack size to
5578 * fit in to the remaining sample size.
5581 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5582 stack_size
= min(stack_size
, (u16
) task_size
);
5584 /* Current header size plus static size and dynamic size. */
5585 header_size
+= 2 * sizeof(u64
);
5587 /* Do we fit in with the current stack dump size? */
5588 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5590 * If we overflow the maximum size for the sample,
5591 * we customize the stack dump size to fit in.
5593 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5594 stack_size
= round_up(stack_size
, sizeof(u64
));
5601 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5602 struct pt_regs
*regs
)
5604 /* Case of a kernel thread, nothing to dump */
5607 perf_output_put(handle
, size
);
5616 * - the size requested by user or the best one we can fit
5617 * in to the sample max size
5619 * - user stack dump data
5621 * - the actual dumped size
5625 perf_output_put(handle
, dump_size
);
5628 sp
= perf_user_stack_pointer(regs
);
5629 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5630 dyn_size
= dump_size
- rem
;
5632 perf_output_skip(handle
, rem
);
5635 perf_output_put(handle
, dyn_size
);
5639 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5640 struct perf_sample_data
*data
,
5641 struct perf_event
*event
)
5643 u64 sample_type
= event
->attr
.sample_type
;
5645 data
->type
= sample_type
;
5646 header
->size
+= event
->id_header_size
;
5648 if (sample_type
& PERF_SAMPLE_TID
) {
5649 /* namespace issues */
5650 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5651 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5654 if (sample_type
& PERF_SAMPLE_TIME
)
5655 data
->time
= perf_event_clock(event
);
5657 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5658 data
->id
= primary_event_id(event
);
5660 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5661 data
->stream_id
= event
->id
;
5663 if (sample_type
& PERF_SAMPLE_CPU
) {
5664 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5665 data
->cpu_entry
.reserved
= 0;
5669 void perf_event_header__init_id(struct perf_event_header
*header
,
5670 struct perf_sample_data
*data
,
5671 struct perf_event
*event
)
5673 if (event
->attr
.sample_id_all
)
5674 __perf_event_header__init_id(header
, data
, event
);
5677 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5678 struct perf_sample_data
*data
)
5680 u64 sample_type
= data
->type
;
5682 if (sample_type
& PERF_SAMPLE_TID
)
5683 perf_output_put(handle
, data
->tid_entry
);
5685 if (sample_type
& PERF_SAMPLE_TIME
)
5686 perf_output_put(handle
, data
->time
);
5688 if (sample_type
& PERF_SAMPLE_ID
)
5689 perf_output_put(handle
, data
->id
);
5691 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5692 perf_output_put(handle
, data
->stream_id
);
5694 if (sample_type
& PERF_SAMPLE_CPU
)
5695 perf_output_put(handle
, data
->cpu_entry
);
5697 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5698 perf_output_put(handle
, data
->id
);
5701 void perf_event__output_id_sample(struct perf_event
*event
,
5702 struct perf_output_handle
*handle
,
5703 struct perf_sample_data
*sample
)
5705 if (event
->attr
.sample_id_all
)
5706 __perf_event__output_id_sample(handle
, sample
);
5709 static void perf_output_read_one(struct perf_output_handle
*handle
,
5710 struct perf_event
*event
,
5711 u64 enabled
, u64 running
)
5713 u64 read_format
= event
->attr
.read_format
;
5717 values
[n
++] = perf_event_count(event
);
5718 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5719 values
[n
++] = enabled
+
5720 atomic64_read(&event
->child_total_time_enabled
);
5722 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5723 values
[n
++] = running
+
5724 atomic64_read(&event
->child_total_time_running
);
5726 if (read_format
& PERF_FORMAT_ID
)
5727 values
[n
++] = primary_event_id(event
);
5729 __output_copy(handle
, values
, n
* sizeof(u64
));
5733 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5735 static void perf_output_read_group(struct perf_output_handle
*handle
,
5736 struct perf_event
*event
,
5737 u64 enabled
, u64 running
)
5739 struct perf_event
*leader
= event
->group_leader
, *sub
;
5740 u64 read_format
= event
->attr
.read_format
;
5744 values
[n
++] = 1 + leader
->nr_siblings
;
5746 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5747 values
[n
++] = enabled
;
5749 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5750 values
[n
++] = running
;
5752 if (leader
!= event
)
5753 leader
->pmu
->read(leader
);
5755 values
[n
++] = perf_event_count(leader
);
5756 if (read_format
& PERF_FORMAT_ID
)
5757 values
[n
++] = primary_event_id(leader
);
5759 __output_copy(handle
, values
, n
* sizeof(u64
));
5761 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5764 if ((sub
!= event
) &&
5765 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5766 sub
->pmu
->read(sub
);
5768 values
[n
++] = perf_event_count(sub
);
5769 if (read_format
& PERF_FORMAT_ID
)
5770 values
[n
++] = primary_event_id(sub
);
5772 __output_copy(handle
, values
, n
* sizeof(u64
));
5776 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5777 PERF_FORMAT_TOTAL_TIME_RUNNING)
5779 static void perf_output_read(struct perf_output_handle
*handle
,
5780 struct perf_event
*event
)
5782 u64 enabled
= 0, running
= 0, now
;
5783 u64 read_format
= event
->attr
.read_format
;
5786 * compute total_time_enabled, total_time_running
5787 * based on snapshot values taken when the event
5788 * was last scheduled in.
5790 * we cannot simply called update_context_time()
5791 * because of locking issue as we are called in
5794 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5795 calc_timer_values(event
, &now
, &enabled
, &running
);
5797 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5798 perf_output_read_group(handle
, event
, enabled
, running
);
5800 perf_output_read_one(handle
, event
, enabled
, running
);
5803 void perf_output_sample(struct perf_output_handle
*handle
,
5804 struct perf_event_header
*header
,
5805 struct perf_sample_data
*data
,
5806 struct perf_event
*event
)
5808 u64 sample_type
= data
->type
;
5810 perf_output_put(handle
, *header
);
5812 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5813 perf_output_put(handle
, data
->id
);
5815 if (sample_type
& PERF_SAMPLE_IP
)
5816 perf_output_put(handle
, data
->ip
);
5818 if (sample_type
& PERF_SAMPLE_TID
)
5819 perf_output_put(handle
, data
->tid_entry
);
5821 if (sample_type
& PERF_SAMPLE_TIME
)
5822 perf_output_put(handle
, data
->time
);
5824 if (sample_type
& PERF_SAMPLE_ADDR
)
5825 perf_output_put(handle
, data
->addr
);
5827 if (sample_type
& PERF_SAMPLE_ID
)
5828 perf_output_put(handle
, data
->id
);
5830 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5831 perf_output_put(handle
, data
->stream_id
);
5833 if (sample_type
& PERF_SAMPLE_CPU
)
5834 perf_output_put(handle
, data
->cpu_entry
);
5836 if (sample_type
& PERF_SAMPLE_PERIOD
)
5837 perf_output_put(handle
, data
->period
);
5839 if (sample_type
& PERF_SAMPLE_READ
)
5840 perf_output_read(handle
, event
);
5842 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5843 if (data
->callchain
) {
5846 if (data
->callchain
)
5847 size
+= data
->callchain
->nr
;
5849 size
*= sizeof(u64
);
5851 __output_copy(handle
, data
->callchain
, size
);
5854 perf_output_put(handle
, nr
);
5858 if (sample_type
& PERF_SAMPLE_RAW
) {
5859 struct perf_raw_record
*raw
= data
->raw
;
5862 struct perf_raw_frag
*frag
= &raw
->frag
;
5864 perf_output_put(handle
, raw
->size
);
5867 __output_custom(handle
, frag
->copy
,
5868 frag
->data
, frag
->size
);
5870 __output_copy(handle
, frag
->data
,
5873 if (perf_raw_frag_last(frag
))
5878 __output_skip(handle
, NULL
, frag
->pad
);
5884 .size
= sizeof(u32
),
5887 perf_output_put(handle
, raw
);
5891 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5892 if (data
->br_stack
) {
5895 size
= data
->br_stack
->nr
5896 * sizeof(struct perf_branch_entry
);
5898 perf_output_put(handle
, data
->br_stack
->nr
);
5899 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5902 * we always store at least the value of nr
5905 perf_output_put(handle
, nr
);
5909 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5910 u64 abi
= data
->regs_user
.abi
;
5913 * If there are no regs to dump, notice it through
5914 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5916 perf_output_put(handle
, abi
);
5919 u64 mask
= event
->attr
.sample_regs_user
;
5920 perf_output_sample_regs(handle
,
5921 data
->regs_user
.regs
,
5926 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5927 perf_output_sample_ustack(handle
,
5928 data
->stack_user_size
,
5929 data
->regs_user
.regs
);
5932 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5933 perf_output_put(handle
, data
->weight
);
5935 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5936 perf_output_put(handle
, data
->data_src
.val
);
5938 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5939 perf_output_put(handle
, data
->txn
);
5941 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5942 u64 abi
= data
->regs_intr
.abi
;
5944 * If there are no regs to dump, notice it through
5945 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5947 perf_output_put(handle
, abi
);
5950 u64 mask
= event
->attr
.sample_regs_intr
;
5952 perf_output_sample_regs(handle
,
5953 data
->regs_intr
.regs
,
5958 if (!event
->attr
.watermark
) {
5959 int wakeup_events
= event
->attr
.wakeup_events
;
5961 if (wakeup_events
) {
5962 struct ring_buffer
*rb
= handle
->rb
;
5963 int events
= local_inc_return(&rb
->events
);
5965 if (events
>= wakeup_events
) {
5966 local_sub(wakeup_events
, &rb
->events
);
5967 local_inc(&rb
->wakeup
);
5973 void perf_prepare_sample(struct perf_event_header
*header
,
5974 struct perf_sample_data
*data
,
5975 struct perf_event
*event
,
5976 struct pt_regs
*regs
)
5978 u64 sample_type
= event
->attr
.sample_type
;
5980 header
->type
= PERF_RECORD_SAMPLE
;
5981 header
->size
= sizeof(*header
) + event
->header_size
;
5984 header
->misc
|= perf_misc_flags(regs
);
5986 __perf_event_header__init_id(header
, data
, event
);
5988 if (sample_type
& PERF_SAMPLE_IP
)
5989 data
->ip
= perf_instruction_pointer(regs
);
5991 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5994 data
->callchain
= perf_callchain(event
, regs
);
5996 if (data
->callchain
)
5997 size
+= data
->callchain
->nr
;
5999 header
->size
+= size
* sizeof(u64
);
6002 if (sample_type
& PERF_SAMPLE_RAW
) {
6003 struct perf_raw_record
*raw
= data
->raw
;
6007 struct perf_raw_frag
*frag
= &raw
->frag
;
6012 if (perf_raw_frag_last(frag
))
6017 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6018 raw
->size
= size
- sizeof(u32
);
6019 frag
->pad
= raw
->size
- sum
;
6024 header
->size
+= size
;
6027 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6028 int size
= sizeof(u64
); /* nr */
6029 if (data
->br_stack
) {
6030 size
+= data
->br_stack
->nr
6031 * sizeof(struct perf_branch_entry
);
6033 header
->size
+= size
;
6036 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6037 perf_sample_regs_user(&data
->regs_user
, regs
,
6038 &data
->regs_user_copy
);
6040 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6041 /* regs dump ABI info */
6042 int size
= sizeof(u64
);
6044 if (data
->regs_user
.regs
) {
6045 u64 mask
= event
->attr
.sample_regs_user
;
6046 size
+= hweight64(mask
) * sizeof(u64
);
6049 header
->size
+= size
;
6052 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6054 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6055 * processed as the last one or have additional check added
6056 * in case new sample type is added, because we could eat
6057 * up the rest of the sample size.
6059 u16 stack_size
= event
->attr
.sample_stack_user
;
6060 u16 size
= sizeof(u64
);
6062 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6063 data
->regs_user
.regs
);
6066 * If there is something to dump, add space for the dump
6067 * itself and for the field that tells the dynamic size,
6068 * which is how many have been actually dumped.
6071 size
+= sizeof(u64
) + stack_size
;
6073 data
->stack_user_size
= stack_size
;
6074 header
->size
+= size
;
6077 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6078 /* regs dump ABI info */
6079 int size
= sizeof(u64
);
6081 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6083 if (data
->regs_intr
.regs
) {
6084 u64 mask
= event
->attr
.sample_regs_intr
;
6086 size
+= hweight64(mask
) * sizeof(u64
);
6089 header
->size
+= size
;
6093 static void __always_inline
6094 __perf_event_output(struct perf_event
*event
,
6095 struct perf_sample_data
*data
,
6096 struct pt_regs
*regs
,
6097 int (*output_begin
)(struct perf_output_handle
*,
6098 struct perf_event
*,
6101 struct perf_output_handle handle
;
6102 struct perf_event_header header
;
6104 /* protect the callchain buffers */
6107 perf_prepare_sample(&header
, data
, event
, regs
);
6109 if (output_begin(&handle
, event
, header
.size
))
6112 perf_output_sample(&handle
, &header
, data
, event
);
6114 perf_output_end(&handle
);
6121 perf_event_output_forward(struct perf_event
*event
,
6122 struct perf_sample_data
*data
,
6123 struct pt_regs
*regs
)
6125 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6129 perf_event_output_backward(struct perf_event
*event
,
6130 struct perf_sample_data
*data
,
6131 struct pt_regs
*regs
)
6133 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6137 perf_event_output(struct perf_event
*event
,
6138 struct perf_sample_data
*data
,
6139 struct pt_regs
*regs
)
6141 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6148 struct perf_read_event
{
6149 struct perf_event_header header
;
6156 perf_event_read_event(struct perf_event
*event
,
6157 struct task_struct
*task
)
6159 struct perf_output_handle handle
;
6160 struct perf_sample_data sample
;
6161 struct perf_read_event read_event
= {
6163 .type
= PERF_RECORD_READ
,
6165 .size
= sizeof(read_event
) + event
->read_size
,
6167 .pid
= perf_event_pid(event
, task
),
6168 .tid
= perf_event_tid(event
, task
),
6172 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6173 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6177 perf_output_put(&handle
, read_event
);
6178 perf_output_read(&handle
, event
);
6179 perf_event__output_id_sample(event
, &handle
, &sample
);
6181 perf_output_end(&handle
);
6184 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6187 perf_iterate_ctx(struct perf_event_context
*ctx
,
6188 perf_iterate_f output
,
6189 void *data
, bool all
)
6191 struct perf_event
*event
;
6193 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6195 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6197 if (!event_filter_match(event
))
6201 output(event
, data
);
6205 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6207 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6208 struct perf_event
*event
;
6210 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6212 * Skip events that are not fully formed yet; ensure that
6213 * if we observe event->ctx, both event and ctx will be
6214 * complete enough. See perf_install_in_context().
6216 if (!smp_load_acquire(&event
->ctx
))
6219 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6221 if (!event_filter_match(event
))
6223 output(event
, data
);
6228 * Iterate all events that need to receive side-band events.
6230 * For new callers; ensure that account_pmu_sb_event() includes
6231 * your event, otherwise it might not get delivered.
6234 perf_iterate_sb(perf_iterate_f output
, void *data
,
6235 struct perf_event_context
*task_ctx
)
6237 struct perf_event_context
*ctx
;
6244 * If we have task_ctx != NULL we only notify the task context itself.
6245 * The task_ctx is set only for EXIT events before releasing task
6249 perf_iterate_ctx(task_ctx
, output
, data
, false);
6253 perf_iterate_sb_cpu(output
, data
);
6255 for_each_task_context_nr(ctxn
) {
6256 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6258 perf_iterate_ctx(ctx
, output
, data
, false);
6266 * Clear all file-based filters at exec, they'll have to be
6267 * re-instated when/if these objects are mmapped again.
6269 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6271 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6272 struct perf_addr_filter
*filter
;
6273 unsigned int restart
= 0, count
= 0;
6274 unsigned long flags
;
6276 if (!has_addr_filter(event
))
6279 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6280 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6281 if (filter
->inode
) {
6282 event
->addr_filters_offs
[count
] = 0;
6290 event
->addr_filters_gen
++;
6291 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6294 perf_event_stop(event
, 1);
6297 void perf_event_exec(void)
6299 struct perf_event_context
*ctx
;
6303 for_each_task_context_nr(ctxn
) {
6304 ctx
= current
->perf_event_ctxp
[ctxn
];
6308 perf_event_enable_on_exec(ctxn
);
6310 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6316 struct remote_output
{
6317 struct ring_buffer
*rb
;
6321 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6323 struct perf_event
*parent
= event
->parent
;
6324 struct remote_output
*ro
= data
;
6325 struct ring_buffer
*rb
= ro
->rb
;
6326 struct stop_event_data sd
= {
6330 if (!has_aux(event
))
6337 * In case of inheritance, it will be the parent that links to the
6338 * ring-buffer, but it will be the child that's actually using it.
6340 * We are using event::rb to determine if the event should be stopped,
6341 * however this may race with ring_buffer_attach() (through set_output),
6342 * which will make us skip the event that actually needs to be stopped.
6343 * So ring_buffer_attach() has to stop an aux event before re-assigning
6346 if (rcu_dereference(parent
->rb
) == rb
)
6347 ro
->err
= __perf_event_stop(&sd
);
6350 static int __perf_pmu_output_stop(void *info
)
6352 struct perf_event
*event
= info
;
6353 struct pmu
*pmu
= event
->pmu
;
6354 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6355 struct remote_output ro
= {
6360 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6361 if (cpuctx
->task_ctx
)
6362 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6369 static void perf_pmu_output_stop(struct perf_event
*event
)
6371 struct perf_event
*iter
;
6376 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6378 * For per-CPU events, we need to make sure that neither they
6379 * nor their children are running; for cpu==-1 events it's
6380 * sufficient to stop the event itself if it's active, since
6381 * it can't have children.
6385 cpu
= READ_ONCE(iter
->oncpu
);
6390 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6391 if (err
== -EAGAIN
) {
6400 * task tracking -- fork/exit
6402 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6405 struct perf_task_event
{
6406 struct task_struct
*task
;
6407 struct perf_event_context
*task_ctx
;
6410 struct perf_event_header header
;
6420 static int perf_event_task_match(struct perf_event
*event
)
6422 return event
->attr
.comm
|| event
->attr
.mmap
||
6423 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6427 static void perf_event_task_output(struct perf_event
*event
,
6430 struct perf_task_event
*task_event
= data
;
6431 struct perf_output_handle handle
;
6432 struct perf_sample_data sample
;
6433 struct task_struct
*task
= task_event
->task
;
6434 int ret
, size
= task_event
->event_id
.header
.size
;
6436 if (!perf_event_task_match(event
))
6439 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6441 ret
= perf_output_begin(&handle
, event
,
6442 task_event
->event_id
.header
.size
);
6446 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6447 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6449 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6450 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6452 task_event
->event_id
.time
= perf_event_clock(event
);
6454 perf_output_put(&handle
, task_event
->event_id
);
6456 perf_event__output_id_sample(event
, &handle
, &sample
);
6458 perf_output_end(&handle
);
6460 task_event
->event_id
.header
.size
= size
;
6463 static void perf_event_task(struct task_struct
*task
,
6464 struct perf_event_context
*task_ctx
,
6467 struct perf_task_event task_event
;
6469 if (!atomic_read(&nr_comm_events
) &&
6470 !atomic_read(&nr_mmap_events
) &&
6471 !atomic_read(&nr_task_events
))
6474 task_event
= (struct perf_task_event
){
6476 .task_ctx
= task_ctx
,
6479 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6481 .size
= sizeof(task_event
.event_id
),
6491 perf_iterate_sb(perf_event_task_output
,
6496 void perf_event_fork(struct task_struct
*task
)
6498 perf_event_task(task
, NULL
, 1);
6499 perf_event_namespaces(task
);
6506 struct perf_comm_event
{
6507 struct task_struct
*task
;
6512 struct perf_event_header header
;
6519 static int perf_event_comm_match(struct perf_event
*event
)
6521 return event
->attr
.comm
;
6524 static void perf_event_comm_output(struct perf_event
*event
,
6527 struct perf_comm_event
*comm_event
= data
;
6528 struct perf_output_handle handle
;
6529 struct perf_sample_data sample
;
6530 int size
= comm_event
->event_id
.header
.size
;
6533 if (!perf_event_comm_match(event
))
6536 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6537 ret
= perf_output_begin(&handle
, event
,
6538 comm_event
->event_id
.header
.size
);
6543 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6544 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6546 perf_output_put(&handle
, comm_event
->event_id
);
6547 __output_copy(&handle
, comm_event
->comm
,
6548 comm_event
->comm_size
);
6550 perf_event__output_id_sample(event
, &handle
, &sample
);
6552 perf_output_end(&handle
);
6554 comm_event
->event_id
.header
.size
= size
;
6557 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6559 char comm
[TASK_COMM_LEN
];
6562 memset(comm
, 0, sizeof(comm
));
6563 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6564 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6566 comm_event
->comm
= comm
;
6567 comm_event
->comm_size
= size
;
6569 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6571 perf_iterate_sb(perf_event_comm_output
,
6576 void perf_event_comm(struct task_struct
*task
, bool exec
)
6578 struct perf_comm_event comm_event
;
6580 if (!atomic_read(&nr_comm_events
))
6583 comm_event
= (struct perf_comm_event
){
6589 .type
= PERF_RECORD_COMM
,
6590 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6598 perf_event_comm_event(&comm_event
);
6602 * namespaces tracking
6605 struct perf_namespaces_event
{
6606 struct task_struct
*task
;
6609 struct perf_event_header header
;
6614 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
6618 static int perf_event_namespaces_match(struct perf_event
*event
)
6620 return event
->attr
.namespaces
;
6623 static void perf_event_namespaces_output(struct perf_event
*event
,
6626 struct perf_namespaces_event
*namespaces_event
= data
;
6627 struct perf_output_handle handle
;
6628 struct perf_sample_data sample
;
6631 if (!perf_event_namespaces_match(event
))
6634 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
6636 ret
= perf_output_begin(&handle
, event
,
6637 namespaces_event
->event_id
.header
.size
);
6641 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
6642 namespaces_event
->task
);
6643 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
6644 namespaces_event
->task
);
6646 perf_output_put(&handle
, namespaces_event
->event_id
);
6648 perf_event__output_id_sample(event
, &handle
, &sample
);
6650 perf_output_end(&handle
);
6653 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
6654 struct task_struct
*task
,
6655 const struct proc_ns_operations
*ns_ops
)
6657 struct path ns_path
;
6658 struct inode
*ns_inode
;
6661 error
= ns_get_path(&ns_path
, task
, ns_ops
);
6663 ns_inode
= ns_path
.dentry
->d_inode
;
6664 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
6665 ns_link_info
->ino
= ns_inode
->i_ino
;
6669 void perf_event_namespaces(struct task_struct
*task
)
6671 struct perf_namespaces_event namespaces_event
;
6672 struct perf_ns_link_info
*ns_link_info
;
6674 if (!atomic_read(&nr_namespaces_events
))
6677 namespaces_event
= (struct perf_namespaces_event
){
6681 .type
= PERF_RECORD_NAMESPACES
,
6683 .size
= sizeof(namespaces_event
.event_id
),
6687 .nr_namespaces
= NR_NAMESPACES
,
6688 /* .link_info[NR_NAMESPACES] */
6692 ns_link_info
= namespaces_event
.event_id
.link_info
;
6694 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
6695 task
, &mntns_operations
);
6697 #ifdef CONFIG_USER_NS
6698 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
6699 task
, &userns_operations
);
6701 #ifdef CONFIG_NET_NS
6702 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
6703 task
, &netns_operations
);
6705 #ifdef CONFIG_UTS_NS
6706 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
6707 task
, &utsns_operations
);
6709 #ifdef CONFIG_IPC_NS
6710 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
6711 task
, &ipcns_operations
);
6713 #ifdef CONFIG_PID_NS
6714 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
6715 task
, &pidns_operations
);
6717 #ifdef CONFIG_CGROUPS
6718 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
6719 task
, &cgroupns_operations
);
6722 perf_iterate_sb(perf_event_namespaces_output
,
6731 struct perf_mmap_event
{
6732 struct vm_area_struct
*vma
;
6734 const char *file_name
;
6742 struct perf_event_header header
;
6752 static int perf_event_mmap_match(struct perf_event
*event
,
6755 struct perf_mmap_event
*mmap_event
= data
;
6756 struct vm_area_struct
*vma
= mmap_event
->vma
;
6757 int executable
= vma
->vm_flags
& VM_EXEC
;
6759 return (!executable
&& event
->attr
.mmap_data
) ||
6760 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6763 static void perf_event_mmap_output(struct perf_event
*event
,
6766 struct perf_mmap_event
*mmap_event
= data
;
6767 struct perf_output_handle handle
;
6768 struct perf_sample_data sample
;
6769 int size
= mmap_event
->event_id
.header
.size
;
6772 if (!perf_event_mmap_match(event
, data
))
6775 if (event
->attr
.mmap2
) {
6776 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6777 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6778 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6779 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6780 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6781 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6782 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6785 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6786 ret
= perf_output_begin(&handle
, event
,
6787 mmap_event
->event_id
.header
.size
);
6791 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6792 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6794 perf_output_put(&handle
, mmap_event
->event_id
);
6796 if (event
->attr
.mmap2
) {
6797 perf_output_put(&handle
, mmap_event
->maj
);
6798 perf_output_put(&handle
, mmap_event
->min
);
6799 perf_output_put(&handle
, mmap_event
->ino
);
6800 perf_output_put(&handle
, mmap_event
->ino_generation
);
6801 perf_output_put(&handle
, mmap_event
->prot
);
6802 perf_output_put(&handle
, mmap_event
->flags
);
6805 __output_copy(&handle
, mmap_event
->file_name
,
6806 mmap_event
->file_size
);
6808 perf_event__output_id_sample(event
, &handle
, &sample
);
6810 perf_output_end(&handle
);
6812 mmap_event
->event_id
.header
.size
= size
;
6815 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6817 struct vm_area_struct
*vma
= mmap_event
->vma
;
6818 struct file
*file
= vma
->vm_file
;
6819 int maj
= 0, min
= 0;
6820 u64 ino
= 0, gen
= 0;
6821 u32 prot
= 0, flags
= 0;
6827 if (vma
->vm_flags
& VM_READ
)
6829 if (vma
->vm_flags
& VM_WRITE
)
6831 if (vma
->vm_flags
& VM_EXEC
)
6834 if (vma
->vm_flags
& VM_MAYSHARE
)
6837 flags
= MAP_PRIVATE
;
6839 if (vma
->vm_flags
& VM_DENYWRITE
)
6840 flags
|= MAP_DENYWRITE
;
6841 if (vma
->vm_flags
& VM_MAYEXEC
)
6842 flags
|= MAP_EXECUTABLE
;
6843 if (vma
->vm_flags
& VM_LOCKED
)
6844 flags
|= MAP_LOCKED
;
6845 if (vma
->vm_flags
& VM_HUGETLB
)
6846 flags
|= MAP_HUGETLB
;
6849 struct inode
*inode
;
6852 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6858 * d_path() works from the end of the rb backwards, so we
6859 * need to add enough zero bytes after the string to handle
6860 * the 64bit alignment we do later.
6862 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6867 inode
= file_inode(vma
->vm_file
);
6868 dev
= inode
->i_sb
->s_dev
;
6870 gen
= inode
->i_generation
;
6876 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6877 name
= (char *) vma
->vm_ops
->name(vma
);
6882 name
= (char *)arch_vma_name(vma
);
6886 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6887 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6891 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6892 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6902 strlcpy(tmp
, name
, sizeof(tmp
));
6906 * Since our buffer works in 8 byte units we need to align our string
6907 * size to a multiple of 8. However, we must guarantee the tail end is
6908 * zero'd out to avoid leaking random bits to userspace.
6910 size
= strlen(name
)+1;
6911 while (!IS_ALIGNED(size
, sizeof(u64
)))
6912 name
[size
++] = '\0';
6914 mmap_event
->file_name
= name
;
6915 mmap_event
->file_size
= size
;
6916 mmap_event
->maj
= maj
;
6917 mmap_event
->min
= min
;
6918 mmap_event
->ino
= ino
;
6919 mmap_event
->ino_generation
= gen
;
6920 mmap_event
->prot
= prot
;
6921 mmap_event
->flags
= flags
;
6923 if (!(vma
->vm_flags
& VM_EXEC
))
6924 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6926 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6928 perf_iterate_sb(perf_event_mmap_output
,
6936 * Check whether inode and address range match filter criteria.
6938 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
6939 struct file
*file
, unsigned long offset
,
6942 if (filter
->inode
!= file_inode(file
))
6945 if (filter
->offset
> offset
+ size
)
6948 if (filter
->offset
+ filter
->size
< offset
)
6954 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
6956 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6957 struct vm_area_struct
*vma
= data
;
6958 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
6959 struct file
*file
= vma
->vm_file
;
6960 struct perf_addr_filter
*filter
;
6961 unsigned int restart
= 0, count
= 0;
6963 if (!has_addr_filter(event
))
6969 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6970 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6971 if (perf_addr_filter_match(filter
, file
, off
,
6972 vma
->vm_end
- vma
->vm_start
)) {
6973 event
->addr_filters_offs
[count
] = vma
->vm_start
;
6981 event
->addr_filters_gen
++;
6982 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6985 perf_event_stop(event
, 1);
6989 * Adjust all task's events' filters to the new vma
6991 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
6993 struct perf_event_context
*ctx
;
6997 * Data tracing isn't supported yet and as such there is no need
6998 * to keep track of anything that isn't related to executable code:
7000 if (!(vma
->vm_flags
& VM_EXEC
))
7004 for_each_task_context_nr(ctxn
) {
7005 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7009 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7014 void perf_event_mmap(struct vm_area_struct
*vma
)
7016 struct perf_mmap_event mmap_event
;
7018 if (!atomic_read(&nr_mmap_events
))
7021 mmap_event
= (struct perf_mmap_event
){
7027 .type
= PERF_RECORD_MMAP
,
7028 .misc
= PERF_RECORD_MISC_USER
,
7033 .start
= vma
->vm_start
,
7034 .len
= vma
->vm_end
- vma
->vm_start
,
7035 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7037 /* .maj (attr_mmap2 only) */
7038 /* .min (attr_mmap2 only) */
7039 /* .ino (attr_mmap2 only) */
7040 /* .ino_generation (attr_mmap2 only) */
7041 /* .prot (attr_mmap2 only) */
7042 /* .flags (attr_mmap2 only) */
7045 perf_addr_filters_adjust(vma
);
7046 perf_event_mmap_event(&mmap_event
);
7049 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7050 unsigned long size
, u64 flags
)
7052 struct perf_output_handle handle
;
7053 struct perf_sample_data sample
;
7054 struct perf_aux_event
{
7055 struct perf_event_header header
;
7061 .type
= PERF_RECORD_AUX
,
7063 .size
= sizeof(rec
),
7071 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7072 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7077 perf_output_put(&handle
, rec
);
7078 perf_event__output_id_sample(event
, &handle
, &sample
);
7080 perf_output_end(&handle
);
7084 * Lost/dropped samples logging
7086 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7088 struct perf_output_handle handle
;
7089 struct perf_sample_data sample
;
7093 struct perf_event_header header
;
7095 } lost_samples_event
= {
7097 .type
= PERF_RECORD_LOST_SAMPLES
,
7099 .size
= sizeof(lost_samples_event
),
7104 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7106 ret
= perf_output_begin(&handle
, event
,
7107 lost_samples_event
.header
.size
);
7111 perf_output_put(&handle
, lost_samples_event
);
7112 perf_event__output_id_sample(event
, &handle
, &sample
);
7113 perf_output_end(&handle
);
7117 * context_switch tracking
7120 struct perf_switch_event
{
7121 struct task_struct
*task
;
7122 struct task_struct
*next_prev
;
7125 struct perf_event_header header
;
7131 static int perf_event_switch_match(struct perf_event
*event
)
7133 return event
->attr
.context_switch
;
7136 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7138 struct perf_switch_event
*se
= data
;
7139 struct perf_output_handle handle
;
7140 struct perf_sample_data sample
;
7143 if (!perf_event_switch_match(event
))
7146 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7147 if (event
->ctx
->task
) {
7148 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7149 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7151 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7152 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7153 se
->event_id
.next_prev_pid
=
7154 perf_event_pid(event
, se
->next_prev
);
7155 se
->event_id
.next_prev_tid
=
7156 perf_event_tid(event
, se
->next_prev
);
7159 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7161 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7165 if (event
->ctx
->task
)
7166 perf_output_put(&handle
, se
->event_id
.header
);
7168 perf_output_put(&handle
, se
->event_id
);
7170 perf_event__output_id_sample(event
, &handle
, &sample
);
7172 perf_output_end(&handle
);
7175 static void perf_event_switch(struct task_struct
*task
,
7176 struct task_struct
*next_prev
, bool sched_in
)
7178 struct perf_switch_event switch_event
;
7180 /* N.B. caller checks nr_switch_events != 0 */
7182 switch_event
= (struct perf_switch_event
){
7184 .next_prev
= next_prev
,
7188 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7191 /* .next_prev_pid */
7192 /* .next_prev_tid */
7196 perf_iterate_sb(perf_event_switch_output
,
7202 * IRQ throttle logging
7205 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7207 struct perf_output_handle handle
;
7208 struct perf_sample_data sample
;
7212 struct perf_event_header header
;
7216 } throttle_event
= {
7218 .type
= PERF_RECORD_THROTTLE
,
7220 .size
= sizeof(throttle_event
),
7222 .time
= perf_event_clock(event
),
7223 .id
= primary_event_id(event
),
7224 .stream_id
= event
->id
,
7228 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7230 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7232 ret
= perf_output_begin(&handle
, event
,
7233 throttle_event
.header
.size
);
7237 perf_output_put(&handle
, throttle_event
);
7238 perf_event__output_id_sample(event
, &handle
, &sample
);
7239 perf_output_end(&handle
);
7242 static void perf_log_itrace_start(struct perf_event
*event
)
7244 struct perf_output_handle handle
;
7245 struct perf_sample_data sample
;
7246 struct perf_aux_event
{
7247 struct perf_event_header header
;
7254 event
= event
->parent
;
7256 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7257 event
->hw
.itrace_started
)
7260 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7261 rec
.header
.misc
= 0;
7262 rec
.header
.size
= sizeof(rec
);
7263 rec
.pid
= perf_event_pid(event
, current
);
7264 rec
.tid
= perf_event_tid(event
, current
);
7266 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7267 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7272 perf_output_put(&handle
, rec
);
7273 perf_event__output_id_sample(event
, &handle
, &sample
);
7275 perf_output_end(&handle
);
7279 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7281 struct hw_perf_event
*hwc
= &event
->hw
;
7285 seq
= __this_cpu_read(perf_throttled_seq
);
7286 if (seq
!= hwc
->interrupts_seq
) {
7287 hwc
->interrupts_seq
= seq
;
7288 hwc
->interrupts
= 1;
7291 if (unlikely(throttle
7292 && hwc
->interrupts
>= max_samples_per_tick
)) {
7293 __this_cpu_inc(perf_throttled_count
);
7294 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7295 hwc
->interrupts
= MAX_INTERRUPTS
;
7296 perf_log_throttle(event
, 0);
7301 if (event
->attr
.freq
) {
7302 u64 now
= perf_clock();
7303 s64 delta
= now
- hwc
->freq_time_stamp
;
7305 hwc
->freq_time_stamp
= now
;
7307 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7308 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7314 int perf_event_account_interrupt(struct perf_event
*event
)
7316 return __perf_event_account_interrupt(event
, 1);
7320 * Generic event overflow handling, sampling.
7323 static int __perf_event_overflow(struct perf_event
*event
,
7324 int throttle
, struct perf_sample_data
*data
,
7325 struct pt_regs
*regs
)
7327 int events
= atomic_read(&event
->event_limit
);
7331 * Non-sampling counters might still use the PMI to fold short
7332 * hardware counters, ignore those.
7334 if (unlikely(!is_sampling_event(event
)))
7337 ret
= __perf_event_account_interrupt(event
, throttle
);
7340 * XXX event_limit might not quite work as expected on inherited
7344 event
->pending_kill
= POLL_IN
;
7345 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7347 event
->pending_kill
= POLL_HUP
;
7349 perf_event_disable_inatomic(event
);
7352 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7354 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7355 event
->pending_wakeup
= 1;
7356 irq_work_queue(&event
->pending
);
7362 int perf_event_overflow(struct perf_event
*event
,
7363 struct perf_sample_data
*data
,
7364 struct pt_regs
*regs
)
7366 return __perf_event_overflow(event
, 1, data
, regs
);
7370 * Generic software event infrastructure
7373 struct swevent_htable
{
7374 struct swevent_hlist
*swevent_hlist
;
7375 struct mutex hlist_mutex
;
7378 /* Recursion avoidance in each contexts */
7379 int recursion
[PERF_NR_CONTEXTS
];
7382 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7385 * We directly increment event->count and keep a second value in
7386 * event->hw.period_left to count intervals. This period event
7387 * is kept in the range [-sample_period, 0] so that we can use the
7391 u64
perf_swevent_set_period(struct perf_event
*event
)
7393 struct hw_perf_event
*hwc
= &event
->hw
;
7394 u64 period
= hwc
->last_period
;
7398 hwc
->last_period
= hwc
->sample_period
;
7401 old
= val
= local64_read(&hwc
->period_left
);
7405 nr
= div64_u64(period
+ val
, period
);
7406 offset
= nr
* period
;
7408 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7414 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7415 struct perf_sample_data
*data
,
7416 struct pt_regs
*regs
)
7418 struct hw_perf_event
*hwc
= &event
->hw
;
7422 overflow
= perf_swevent_set_period(event
);
7424 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7427 for (; overflow
; overflow
--) {
7428 if (__perf_event_overflow(event
, throttle
,
7431 * We inhibit the overflow from happening when
7432 * hwc->interrupts == MAX_INTERRUPTS.
7440 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7441 struct perf_sample_data
*data
,
7442 struct pt_regs
*regs
)
7444 struct hw_perf_event
*hwc
= &event
->hw
;
7446 local64_add(nr
, &event
->count
);
7451 if (!is_sampling_event(event
))
7454 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7456 return perf_swevent_overflow(event
, 1, data
, regs
);
7458 data
->period
= event
->hw
.last_period
;
7460 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7461 return perf_swevent_overflow(event
, 1, data
, regs
);
7463 if (local64_add_negative(nr
, &hwc
->period_left
))
7466 perf_swevent_overflow(event
, 0, data
, regs
);
7469 static int perf_exclude_event(struct perf_event
*event
,
7470 struct pt_regs
*regs
)
7472 if (event
->hw
.state
& PERF_HES_STOPPED
)
7476 if (event
->attr
.exclude_user
&& user_mode(regs
))
7479 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7486 static int perf_swevent_match(struct perf_event
*event
,
7487 enum perf_type_id type
,
7489 struct perf_sample_data
*data
,
7490 struct pt_regs
*regs
)
7492 if (event
->attr
.type
!= type
)
7495 if (event
->attr
.config
!= event_id
)
7498 if (perf_exclude_event(event
, regs
))
7504 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7506 u64 val
= event_id
| (type
<< 32);
7508 return hash_64(val
, SWEVENT_HLIST_BITS
);
7511 static inline struct hlist_head
*
7512 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7514 u64 hash
= swevent_hash(type
, event_id
);
7516 return &hlist
->heads
[hash
];
7519 /* For the read side: events when they trigger */
7520 static inline struct hlist_head
*
7521 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7523 struct swevent_hlist
*hlist
;
7525 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7529 return __find_swevent_head(hlist
, type
, event_id
);
7532 /* For the event head insertion and removal in the hlist */
7533 static inline struct hlist_head
*
7534 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7536 struct swevent_hlist
*hlist
;
7537 u32 event_id
= event
->attr
.config
;
7538 u64 type
= event
->attr
.type
;
7541 * Event scheduling is always serialized against hlist allocation
7542 * and release. Which makes the protected version suitable here.
7543 * The context lock guarantees that.
7545 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7546 lockdep_is_held(&event
->ctx
->lock
));
7550 return __find_swevent_head(hlist
, type
, event_id
);
7553 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7555 struct perf_sample_data
*data
,
7556 struct pt_regs
*regs
)
7558 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7559 struct perf_event
*event
;
7560 struct hlist_head
*head
;
7563 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7567 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7568 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7569 perf_swevent_event(event
, nr
, data
, regs
);
7575 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7577 int perf_swevent_get_recursion_context(void)
7579 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7581 return get_recursion_context(swhash
->recursion
);
7583 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7585 void perf_swevent_put_recursion_context(int rctx
)
7587 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7589 put_recursion_context(swhash
->recursion
, rctx
);
7592 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7594 struct perf_sample_data data
;
7596 if (WARN_ON_ONCE(!regs
))
7599 perf_sample_data_init(&data
, addr
, 0);
7600 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7603 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7607 preempt_disable_notrace();
7608 rctx
= perf_swevent_get_recursion_context();
7609 if (unlikely(rctx
< 0))
7612 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7614 perf_swevent_put_recursion_context(rctx
);
7616 preempt_enable_notrace();
7619 static void perf_swevent_read(struct perf_event
*event
)
7623 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7625 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7626 struct hw_perf_event
*hwc
= &event
->hw
;
7627 struct hlist_head
*head
;
7629 if (is_sampling_event(event
)) {
7630 hwc
->last_period
= hwc
->sample_period
;
7631 perf_swevent_set_period(event
);
7634 hwc
->state
= !(flags
& PERF_EF_START
);
7636 head
= find_swevent_head(swhash
, event
);
7637 if (WARN_ON_ONCE(!head
))
7640 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7641 perf_event_update_userpage(event
);
7646 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7648 hlist_del_rcu(&event
->hlist_entry
);
7651 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7653 event
->hw
.state
= 0;
7656 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7658 event
->hw
.state
= PERF_HES_STOPPED
;
7661 /* Deref the hlist from the update side */
7662 static inline struct swevent_hlist
*
7663 swevent_hlist_deref(struct swevent_htable
*swhash
)
7665 return rcu_dereference_protected(swhash
->swevent_hlist
,
7666 lockdep_is_held(&swhash
->hlist_mutex
));
7669 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7671 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7676 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7677 kfree_rcu(hlist
, rcu_head
);
7680 static void swevent_hlist_put_cpu(int cpu
)
7682 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7684 mutex_lock(&swhash
->hlist_mutex
);
7686 if (!--swhash
->hlist_refcount
)
7687 swevent_hlist_release(swhash
);
7689 mutex_unlock(&swhash
->hlist_mutex
);
7692 static void swevent_hlist_put(void)
7696 for_each_possible_cpu(cpu
)
7697 swevent_hlist_put_cpu(cpu
);
7700 static int swevent_hlist_get_cpu(int cpu
)
7702 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7705 mutex_lock(&swhash
->hlist_mutex
);
7706 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
7707 struct swevent_hlist
*hlist
;
7709 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7714 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7716 swhash
->hlist_refcount
++;
7718 mutex_unlock(&swhash
->hlist_mutex
);
7723 static int swevent_hlist_get(void)
7725 int err
, cpu
, failed_cpu
;
7728 for_each_possible_cpu(cpu
) {
7729 err
= swevent_hlist_get_cpu(cpu
);
7739 for_each_possible_cpu(cpu
) {
7740 if (cpu
== failed_cpu
)
7742 swevent_hlist_put_cpu(cpu
);
7749 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7751 static void sw_perf_event_destroy(struct perf_event
*event
)
7753 u64 event_id
= event
->attr
.config
;
7755 WARN_ON(event
->parent
);
7757 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7758 swevent_hlist_put();
7761 static int perf_swevent_init(struct perf_event
*event
)
7763 u64 event_id
= event
->attr
.config
;
7765 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7769 * no branch sampling for software events
7771 if (has_branch_stack(event
))
7775 case PERF_COUNT_SW_CPU_CLOCK
:
7776 case PERF_COUNT_SW_TASK_CLOCK
:
7783 if (event_id
>= PERF_COUNT_SW_MAX
)
7786 if (!event
->parent
) {
7789 err
= swevent_hlist_get();
7793 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7794 event
->destroy
= sw_perf_event_destroy
;
7800 static struct pmu perf_swevent
= {
7801 .task_ctx_nr
= perf_sw_context
,
7803 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7805 .event_init
= perf_swevent_init
,
7806 .add
= perf_swevent_add
,
7807 .del
= perf_swevent_del
,
7808 .start
= perf_swevent_start
,
7809 .stop
= perf_swevent_stop
,
7810 .read
= perf_swevent_read
,
7813 #ifdef CONFIG_EVENT_TRACING
7815 static int perf_tp_filter_match(struct perf_event
*event
,
7816 struct perf_sample_data
*data
)
7818 void *record
= data
->raw
->frag
.data
;
7820 /* only top level events have filters set */
7822 event
= event
->parent
;
7824 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7829 static int perf_tp_event_match(struct perf_event
*event
,
7830 struct perf_sample_data
*data
,
7831 struct pt_regs
*regs
)
7833 if (event
->hw
.state
& PERF_HES_STOPPED
)
7836 * All tracepoints are from kernel-space.
7838 if (event
->attr
.exclude_kernel
)
7841 if (!perf_tp_filter_match(event
, data
))
7847 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7848 struct trace_event_call
*call
, u64 count
,
7849 struct pt_regs
*regs
, struct hlist_head
*head
,
7850 struct task_struct
*task
)
7852 struct bpf_prog
*prog
= call
->prog
;
7855 *(struct pt_regs
**)raw_data
= regs
;
7856 if (!trace_call_bpf(prog
, raw_data
) || hlist_empty(head
)) {
7857 perf_swevent_put_recursion_context(rctx
);
7861 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7864 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7866 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7867 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7868 struct task_struct
*task
)
7870 struct perf_sample_data data
;
7871 struct perf_event
*event
;
7873 struct perf_raw_record raw
= {
7880 perf_sample_data_init(&data
, 0, 0);
7883 perf_trace_buf_update(record
, event_type
);
7885 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7886 if (perf_tp_event_match(event
, &data
, regs
))
7887 perf_swevent_event(event
, count
, &data
, regs
);
7891 * If we got specified a target task, also iterate its context and
7892 * deliver this event there too.
7894 if (task
&& task
!= current
) {
7895 struct perf_event_context
*ctx
;
7896 struct trace_entry
*entry
= record
;
7899 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7903 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7904 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7906 if (event
->attr
.config
!= entry
->type
)
7908 if (perf_tp_event_match(event
, &data
, regs
))
7909 perf_swevent_event(event
, count
, &data
, regs
);
7915 perf_swevent_put_recursion_context(rctx
);
7917 EXPORT_SYMBOL_GPL(perf_tp_event
);
7919 static void tp_perf_event_destroy(struct perf_event
*event
)
7921 perf_trace_destroy(event
);
7924 static int perf_tp_event_init(struct perf_event
*event
)
7928 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7932 * no branch sampling for tracepoint events
7934 if (has_branch_stack(event
))
7937 err
= perf_trace_init(event
);
7941 event
->destroy
= tp_perf_event_destroy
;
7946 static struct pmu perf_tracepoint
= {
7947 .task_ctx_nr
= perf_sw_context
,
7949 .event_init
= perf_tp_event_init
,
7950 .add
= perf_trace_add
,
7951 .del
= perf_trace_del
,
7952 .start
= perf_swevent_start
,
7953 .stop
= perf_swevent_stop
,
7954 .read
= perf_swevent_read
,
7957 static inline void perf_tp_register(void)
7959 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7962 static void perf_event_free_filter(struct perf_event
*event
)
7964 ftrace_profile_free_filter(event
);
7967 #ifdef CONFIG_BPF_SYSCALL
7968 static void bpf_overflow_handler(struct perf_event
*event
,
7969 struct perf_sample_data
*data
,
7970 struct pt_regs
*regs
)
7972 struct bpf_perf_event_data_kern ctx
= {
7979 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
7982 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
7985 __this_cpu_dec(bpf_prog_active
);
7990 event
->orig_overflow_handler(event
, data
, regs
);
7993 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
7995 struct bpf_prog
*prog
;
7997 if (event
->overflow_handler_context
)
7998 /* hw breakpoint or kernel counter */
8004 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8006 return PTR_ERR(prog
);
8009 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8010 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8014 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8016 struct bpf_prog
*prog
= event
->prog
;
8021 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
8026 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8030 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8035 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8037 bool is_kprobe
, is_tracepoint
;
8038 struct bpf_prog
*prog
;
8040 if (event
->attr
.type
== PERF_TYPE_HARDWARE
||
8041 event
->attr
.type
== PERF_TYPE_SOFTWARE
)
8042 return perf_event_set_bpf_handler(event
, prog_fd
);
8044 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8047 if (event
->tp_event
->prog
)
8050 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
8051 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
8052 if (!is_kprobe
&& !is_tracepoint
)
8053 /* bpf programs can only be attached to u/kprobe or tracepoint */
8056 prog
= bpf_prog_get(prog_fd
);
8058 return PTR_ERR(prog
);
8060 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
8061 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
8062 /* valid fd, but invalid bpf program type */
8067 if (is_tracepoint
) {
8068 int off
= trace_event_get_offsets(event
->tp_event
);
8070 if (prog
->aux
->max_ctx_offset
> off
) {
8075 event
->tp_event
->prog
= prog
;
8080 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8082 struct bpf_prog
*prog
;
8084 perf_event_free_bpf_handler(event
);
8086 if (!event
->tp_event
)
8089 prog
= event
->tp_event
->prog
;
8091 event
->tp_event
->prog
= NULL
;
8098 static inline void perf_tp_register(void)
8102 static void perf_event_free_filter(struct perf_event
*event
)
8106 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8111 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8114 #endif /* CONFIG_EVENT_TRACING */
8116 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8117 void perf_bp_event(struct perf_event
*bp
, void *data
)
8119 struct perf_sample_data sample
;
8120 struct pt_regs
*regs
= data
;
8122 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
8124 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
8125 perf_swevent_event(bp
, 1, &sample
, regs
);
8130 * Allocate a new address filter
8132 static struct perf_addr_filter
*
8133 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
8135 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8136 struct perf_addr_filter
*filter
;
8138 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8142 INIT_LIST_HEAD(&filter
->entry
);
8143 list_add_tail(&filter
->entry
, filters
);
8148 static void free_filters_list(struct list_head
*filters
)
8150 struct perf_addr_filter
*filter
, *iter
;
8152 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8154 iput(filter
->inode
);
8155 list_del(&filter
->entry
);
8161 * Free existing address filters and optionally install new ones
8163 static void perf_addr_filters_splice(struct perf_event
*event
,
8164 struct list_head
*head
)
8166 unsigned long flags
;
8169 if (!has_addr_filter(event
))
8172 /* don't bother with children, they don't have their own filters */
8176 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8178 list_splice_init(&event
->addr_filters
.list
, &list
);
8180 list_splice(head
, &event
->addr_filters
.list
);
8182 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8184 free_filters_list(&list
);
8188 * Scan through mm's vmas and see if one of them matches the
8189 * @filter; if so, adjust filter's address range.
8190 * Called with mm::mmap_sem down for reading.
8192 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8193 struct mm_struct
*mm
)
8195 struct vm_area_struct
*vma
;
8197 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8198 struct file
*file
= vma
->vm_file
;
8199 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8200 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8205 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8208 return vma
->vm_start
;
8215 * Update event's address range filters based on the
8216 * task's existing mappings, if any.
8218 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8220 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8221 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8222 struct perf_addr_filter
*filter
;
8223 struct mm_struct
*mm
= NULL
;
8224 unsigned int count
= 0;
8225 unsigned long flags
;
8228 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8229 * will stop on the parent's child_mutex that our caller is also holding
8231 if (task
== TASK_TOMBSTONE
)
8234 if (!ifh
->nr_file_filters
)
8237 mm
= get_task_mm(event
->ctx
->task
);
8241 down_read(&mm
->mmap_sem
);
8243 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8244 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8245 event
->addr_filters_offs
[count
] = 0;
8248 * Adjust base offset if the filter is associated to a binary
8249 * that needs to be mapped:
8252 event
->addr_filters_offs
[count
] =
8253 perf_addr_filter_apply(filter
, mm
);
8258 event
->addr_filters_gen
++;
8259 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8261 up_read(&mm
->mmap_sem
);
8266 perf_event_stop(event
, 1);
8270 * Address range filtering: limiting the data to certain
8271 * instruction address ranges. Filters are ioctl()ed to us from
8272 * userspace as ascii strings.
8274 * Filter string format:
8277 * where ACTION is one of the
8278 * * "filter": limit the trace to this region
8279 * * "start": start tracing from this address
8280 * * "stop": stop tracing at this address/region;
8282 * * for kernel addresses: <start address>[/<size>]
8283 * * for object files: <start address>[/<size>]@</path/to/object/file>
8285 * if <size> is not specified, the range is treated as a single address.
8299 IF_STATE_ACTION
= 0,
8304 static const match_table_t if_tokens
= {
8305 { IF_ACT_FILTER
, "filter" },
8306 { IF_ACT_START
, "start" },
8307 { IF_ACT_STOP
, "stop" },
8308 { IF_SRC_FILE
, "%u/%u@%s" },
8309 { IF_SRC_KERNEL
, "%u/%u" },
8310 { IF_SRC_FILEADDR
, "%u@%s" },
8311 { IF_SRC_KERNELADDR
, "%u" },
8312 { IF_ACT_NONE
, NULL
},
8316 * Address filter string parser
8319 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8320 struct list_head
*filters
)
8322 struct perf_addr_filter
*filter
= NULL
;
8323 char *start
, *orig
, *filename
= NULL
;
8325 substring_t args
[MAX_OPT_ARGS
];
8326 int state
= IF_STATE_ACTION
, token
;
8327 unsigned int kernel
= 0;
8330 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8334 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8340 /* filter definition begins */
8341 if (state
== IF_STATE_ACTION
) {
8342 filter
= perf_addr_filter_new(event
, filters
);
8347 token
= match_token(start
, if_tokens
, args
);
8354 if (state
!= IF_STATE_ACTION
)
8357 state
= IF_STATE_SOURCE
;
8360 case IF_SRC_KERNELADDR
:
8364 case IF_SRC_FILEADDR
:
8366 if (state
!= IF_STATE_SOURCE
)
8369 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8373 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8377 if (filter
->range
) {
8379 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8384 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8385 int fpos
= filter
->range
? 2 : 1;
8387 filename
= match_strdup(&args
[fpos
]);
8394 state
= IF_STATE_END
;
8402 * Filter definition is fully parsed, validate and install it.
8403 * Make sure that it doesn't contradict itself or the event's
8406 if (state
== IF_STATE_END
) {
8408 if (kernel
&& event
->attr
.exclude_kernel
)
8416 * For now, we only support file-based filters
8417 * in per-task events; doing so for CPU-wide
8418 * events requires additional context switching
8419 * trickery, since same object code will be
8420 * mapped at different virtual addresses in
8421 * different processes.
8424 if (!event
->ctx
->task
)
8425 goto fail_free_name
;
8427 /* look up the path and grab its inode */
8428 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8430 goto fail_free_name
;
8432 filter
->inode
= igrab(d_inode(path
.dentry
));
8438 if (!filter
->inode
||
8439 !S_ISREG(filter
->inode
->i_mode
))
8440 /* free_filters_list() will iput() */
8443 event
->addr_filters
.nr_file_filters
++;
8446 /* ready to consume more filters */
8447 state
= IF_STATE_ACTION
;
8452 if (state
!= IF_STATE_ACTION
)
8462 free_filters_list(filters
);
8469 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8475 * Since this is called in perf_ioctl() path, we're already holding
8478 lockdep_assert_held(&event
->ctx
->mutex
);
8480 if (WARN_ON_ONCE(event
->parent
))
8483 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8485 goto fail_clear_files
;
8487 ret
= event
->pmu
->addr_filters_validate(&filters
);
8489 goto fail_free_filters
;
8491 /* remove existing filters, if any */
8492 perf_addr_filters_splice(event
, &filters
);
8494 /* install new filters */
8495 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8500 free_filters_list(&filters
);
8503 event
->addr_filters
.nr_file_filters
= 0;
8508 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8513 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8514 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8515 !has_addr_filter(event
))
8518 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8519 if (IS_ERR(filter_str
))
8520 return PTR_ERR(filter_str
);
8522 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8523 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8524 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
8526 else if (has_addr_filter(event
))
8527 ret
= perf_event_set_addr_filter(event
, filter_str
);
8534 * hrtimer based swevent callback
8537 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8539 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8540 struct perf_sample_data data
;
8541 struct pt_regs
*regs
;
8542 struct perf_event
*event
;
8545 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8547 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8548 return HRTIMER_NORESTART
;
8550 event
->pmu
->read(event
);
8552 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8553 regs
= get_irq_regs();
8555 if (regs
&& !perf_exclude_event(event
, regs
)) {
8556 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8557 if (__perf_event_overflow(event
, 1, &data
, regs
))
8558 ret
= HRTIMER_NORESTART
;
8561 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8562 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8567 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8569 struct hw_perf_event
*hwc
= &event
->hw
;
8572 if (!is_sampling_event(event
))
8575 period
= local64_read(&hwc
->period_left
);
8580 local64_set(&hwc
->period_left
, 0);
8582 period
= max_t(u64
, 10000, hwc
->sample_period
);
8584 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8585 HRTIMER_MODE_REL_PINNED
);
8588 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8590 struct hw_perf_event
*hwc
= &event
->hw
;
8592 if (is_sampling_event(event
)) {
8593 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8594 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8596 hrtimer_cancel(&hwc
->hrtimer
);
8600 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8602 struct hw_perf_event
*hwc
= &event
->hw
;
8604 if (!is_sampling_event(event
))
8607 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8608 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8611 * Since hrtimers have a fixed rate, we can do a static freq->period
8612 * mapping and avoid the whole period adjust feedback stuff.
8614 if (event
->attr
.freq
) {
8615 long freq
= event
->attr
.sample_freq
;
8617 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8618 hwc
->sample_period
= event
->attr
.sample_period
;
8619 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8620 hwc
->last_period
= hwc
->sample_period
;
8621 event
->attr
.freq
= 0;
8626 * Software event: cpu wall time clock
8629 static void cpu_clock_event_update(struct perf_event
*event
)
8634 now
= local_clock();
8635 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8636 local64_add(now
- prev
, &event
->count
);
8639 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8641 local64_set(&event
->hw
.prev_count
, local_clock());
8642 perf_swevent_start_hrtimer(event
);
8645 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8647 perf_swevent_cancel_hrtimer(event
);
8648 cpu_clock_event_update(event
);
8651 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8653 if (flags
& PERF_EF_START
)
8654 cpu_clock_event_start(event
, flags
);
8655 perf_event_update_userpage(event
);
8660 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8662 cpu_clock_event_stop(event
, flags
);
8665 static void cpu_clock_event_read(struct perf_event
*event
)
8667 cpu_clock_event_update(event
);
8670 static int cpu_clock_event_init(struct perf_event
*event
)
8672 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8675 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8679 * no branch sampling for software events
8681 if (has_branch_stack(event
))
8684 perf_swevent_init_hrtimer(event
);
8689 static struct pmu perf_cpu_clock
= {
8690 .task_ctx_nr
= perf_sw_context
,
8692 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8694 .event_init
= cpu_clock_event_init
,
8695 .add
= cpu_clock_event_add
,
8696 .del
= cpu_clock_event_del
,
8697 .start
= cpu_clock_event_start
,
8698 .stop
= cpu_clock_event_stop
,
8699 .read
= cpu_clock_event_read
,
8703 * Software event: task time clock
8706 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8711 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8713 local64_add(delta
, &event
->count
);
8716 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8718 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8719 perf_swevent_start_hrtimer(event
);
8722 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8724 perf_swevent_cancel_hrtimer(event
);
8725 task_clock_event_update(event
, event
->ctx
->time
);
8728 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8730 if (flags
& PERF_EF_START
)
8731 task_clock_event_start(event
, flags
);
8732 perf_event_update_userpage(event
);
8737 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8739 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8742 static void task_clock_event_read(struct perf_event
*event
)
8744 u64 now
= perf_clock();
8745 u64 delta
= now
- event
->ctx
->timestamp
;
8746 u64 time
= event
->ctx
->time
+ delta
;
8748 task_clock_event_update(event
, time
);
8751 static int task_clock_event_init(struct perf_event
*event
)
8753 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8756 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8760 * no branch sampling for software events
8762 if (has_branch_stack(event
))
8765 perf_swevent_init_hrtimer(event
);
8770 static struct pmu perf_task_clock
= {
8771 .task_ctx_nr
= perf_sw_context
,
8773 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8775 .event_init
= task_clock_event_init
,
8776 .add
= task_clock_event_add
,
8777 .del
= task_clock_event_del
,
8778 .start
= task_clock_event_start
,
8779 .stop
= task_clock_event_stop
,
8780 .read
= task_clock_event_read
,
8783 static void perf_pmu_nop_void(struct pmu
*pmu
)
8787 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8791 static int perf_pmu_nop_int(struct pmu
*pmu
)
8796 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8798 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8800 __this_cpu_write(nop_txn_flags
, flags
);
8802 if (flags
& ~PERF_PMU_TXN_ADD
)
8805 perf_pmu_disable(pmu
);
8808 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8810 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8812 __this_cpu_write(nop_txn_flags
, 0);
8814 if (flags
& ~PERF_PMU_TXN_ADD
)
8817 perf_pmu_enable(pmu
);
8821 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8823 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8825 __this_cpu_write(nop_txn_flags
, 0);
8827 if (flags
& ~PERF_PMU_TXN_ADD
)
8830 perf_pmu_enable(pmu
);
8833 static int perf_event_idx_default(struct perf_event
*event
)
8839 * Ensures all contexts with the same task_ctx_nr have the same
8840 * pmu_cpu_context too.
8842 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8849 list_for_each_entry(pmu
, &pmus
, entry
) {
8850 if (pmu
->task_ctx_nr
== ctxn
)
8851 return pmu
->pmu_cpu_context
;
8857 static void free_pmu_context(struct pmu
*pmu
)
8859 mutex_lock(&pmus_lock
);
8860 free_percpu(pmu
->pmu_cpu_context
);
8861 mutex_unlock(&pmus_lock
);
8865 * Let userspace know that this PMU supports address range filtering:
8867 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8868 struct device_attribute
*attr
,
8871 struct pmu
*pmu
= dev_get_drvdata(dev
);
8873 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8875 DEVICE_ATTR_RO(nr_addr_filters
);
8877 static struct idr pmu_idr
;
8880 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8882 struct pmu
*pmu
= dev_get_drvdata(dev
);
8884 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8886 static DEVICE_ATTR_RO(type
);
8889 perf_event_mux_interval_ms_show(struct device
*dev
,
8890 struct device_attribute
*attr
,
8893 struct pmu
*pmu
= dev_get_drvdata(dev
);
8895 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8898 static DEFINE_MUTEX(mux_interval_mutex
);
8901 perf_event_mux_interval_ms_store(struct device
*dev
,
8902 struct device_attribute
*attr
,
8903 const char *buf
, size_t count
)
8905 struct pmu
*pmu
= dev_get_drvdata(dev
);
8906 int timer
, cpu
, ret
;
8908 ret
= kstrtoint(buf
, 0, &timer
);
8915 /* same value, noting to do */
8916 if (timer
== pmu
->hrtimer_interval_ms
)
8919 mutex_lock(&mux_interval_mutex
);
8920 pmu
->hrtimer_interval_ms
= timer
;
8922 /* update all cpuctx for this PMU */
8924 for_each_online_cpu(cpu
) {
8925 struct perf_cpu_context
*cpuctx
;
8926 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8927 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
8929 cpu_function_call(cpu
,
8930 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
8933 mutex_unlock(&mux_interval_mutex
);
8937 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
8939 static struct attribute
*pmu_dev_attrs
[] = {
8940 &dev_attr_type
.attr
,
8941 &dev_attr_perf_event_mux_interval_ms
.attr
,
8944 ATTRIBUTE_GROUPS(pmu_dev
);
8946 static int pmu_bus_running
;
8947 static struct bus_type pmu_bus
= {
8948 .name
= "event_source",
8949 .dev_groups
= pmu_dev_groups
,
8952 static void pmu_dev_release(struct device
*dev
)
8957 static int pmu_dev_alloc(struct pmu
*pmu
)
8961 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
8965 pmu
->dev
->groups
= pmu
->attr_groups
;
8966 device_initialize(pmu
->dev
);
8967 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
8971 dev_set_drvdata(pmu
->dev
, pmu
);
8972 pmu
->dev
->bus
= &pmu_bus
;
8973 pmu
->dev
->release
= pmu_dev_release
;
8974 ret
= device_add(pmu
->dev
);
8978 /* For PMUs with address filters, throw in an extra attribute: */
8979 if (pmu
->nr_addr_filters
)
8980 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
8989 device_del(pmu
->dev
);
8992 put_device(pmu
->dev
);
8996 static struct lock_class_key cpuctx_mutex
;
8997 static struct lock_class_key cpuctx_lock
;
8999 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
9003 mutex_lock(&pmus_lock
);
9005 pmu
->pmu_disable_count
= alloc_percpu(int);
9006 if (!pmu
->pmu_disable_count
)
9015 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
9023 if (pmu_bus_running
) {
9024 ret
= pmu_dev_alloc(pmu
);
9030 if (pmu
->task_ctx_nr
== perf_hw_context
) {
9031 static int hw_context_taken
= 0;
9034 * Other than systems with heterogeneous CPUs, it never makes
9035 * sense for two PMUs to share perf_hw_context. PMUs which are
9036 * uncore must use perf_invalid_context.
9038 if (WARN_ON_ONCE(hw_context_taken
&&
9039 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
9040 pmu
->task_ctx_nr
= perf_invalid_context
;
9042 hw_context_taken
= 1;
9045 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
9046 if (pmu
->pmu_cpu_context
)
9047 goto got_cpu_context
;
9050 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
9051 if (!pmu
->pmu_cpu_context
)
9054 for_each_possible_cpu(cpu
) {
9055 struct perf_cpu_context
*cpuctx
;
9057 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9058 __perf_event_init_context(&cpuctx
->ctx
);
9059 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
9060 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
9061 cpuctx
->ctx
.pmu
= pmu
;
9063 __perf_mux_hrtimer_init(cpuctx
, cpu
);
9067 if (!pmu
->start_txn
) {
9068 if (pmu
->pmu_enable
) {
9070 * If we have pmu_enable/pmu_disable calls, install
9071 * transaction stubs that use that to try and batch
9072 * hardware accesses.
9074 pmu
->start_txn
= perf_pmu_start_txn
;
9075 pmu
->commit_txn
= perf_pmu_commit_txn
;
9076 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
9078 pmu
->start_txn
= perf_pmu_nop_txn
;
9079 pmu
->commit_txn
= perf_pmu_nop_int
;
9080 pmu
->cancel_txn
= perf_pmu_nop_void
;
9084 if (!pmu
->pmu_enable
) {
9085 pmu
->pmu_enable
= perf_pmu_nop_void
;
9086 pmu
->pmu_disable
= perf_pmu_nop_void
;
9089 if (!pmu
->event_idx
)
9090 pmu
->event_idx
= perf_event_idx_default
;
9092 list_add_rcu(&pmu
->entry
, &pmus
);
9093 atomic_set(&pmu
->exclusive_cnt
, 0);
9096 mutex_unlock(&pmus_lock
);
9101 device_del(pmu
->dev
);
9102 put_device(pmu
->dev
);
9105 if (pmu
->type
>= PERF_TYPE_MAX
)
9106 idr_remove(&pmu_idr
, pmu
->type
);
9109 free_percpu(pmu
->pmu_disable_count
);
9112 EXPORT_SYMBOL_GPL(perf_pmu_register
);
9114 void perf_pmu_unregister(struct pmu
*pmu
)
9118 mutex_lock(&pmus_lock
);
9119 remove_device
= pmu_bus_running
;
9120 list_del_rcu(&pmu
->entry
);
9121 mutex_unlock(&pmus_lock
);
9124 * We dereference the pmu list under both SRCU and regular RCU, so
9125 * synchronize against both of those.
9127 synchronize_srcu(&pmus_srcu
);
9130 free_percpu(pmu
->pmu_disable_count
);
9131 if (pmu
->type
>= PERF_TYPE_MAX
)
9132 idr_remove(&pmu_idr
, pmu
->type
);
9133 if (remove_device
) {
9134 if (pmu
->nr_addr_filters
)
9135 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9136 device_del(pmu
->dev
);
9137 put_device(pmu
->dev
);
9139 free_pmu_context(pmu
);
9141 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9143 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9145 struct perf_event_context
*ctx
= NULL
;
9148 if (!try_module_get(pmu
->module
))
9151 if (event
->group_leader
!= event
) {
9153 * This ctx->mutex can nest when we're called through
9154 * inheritance. See the perf_event_ctx_lock_nested() comment.
9156 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9157 SINGLE_DEPTH_NESTING
);
9162 ret
= pmu
->event_init(event
);
9165 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9168 module_put(pmu
->module
);
9173 static struct pmu
*perf_init_event(struct perf_event
*event
)
9175 struct pmu
*pmu
= NULL
;
9179 idx
= srcu_read_lock(&pmus_srcu
);
9181 /* Try parent's PMU first: */
9182 if (event
->parent
&& event
->parent
->pmu
) {
9183 pmu
= event
->parent
->pmu
;
9184 ret
= perf_try_init_event(pmu
, event
);
9190 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9193 ret
= perf_try_init_event(pmu
, event
);
9199 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9200 ret
= perf_try_init_event(pmu
, event
);
9204 if (ret
!= -ENOENT
) {
9209 pmu
= ERR_PTR(-ENOENT
);
9211 srcu_read_unlock(&pmus_srcu
, idx
);
9216 static void attach_sb_event(struct perf_event
*event
)
9218 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9220 raw_spin_lock(&pel
->lock
);
9221 list_add_rcu(&event
->sb_list
, &pel
->list
);
9222 raw_spin_unlock(&pel
->lock
);
9226 * We keep a list of all !task (and therefore per-cpu) events
9227 * that need to receive side-band records.
9229 * This avoids having to scan all the various PMU per-cpu contexts
9232 static void account_pmu_sb_event(struct perf_event
*event
)
9234 if (is_sb_event(event
))
9235 attach_sb_event(event
);
9238 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9243 if (is_cgroup_event(event
))
9244 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9247 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9248 static void account_freq_event_nohz(void)
9250 #ifdef CONFIG_NO_HZ_FULL
9251 /* Lock so we don't race with concurrent unaccount */
9252 spin_lock(&nr_freq_lock
);
9253 if (atomic_inc_return(&nr_freq_events
) == 1)
9254 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9255 spin_unlock(&nr_freq_lock
);
9259 static void account_freq_event(void)
9261 if (tick_nohz_full_enabled())
9262 account_freq_event_nohz();
9264 atomic_inc(&nr_freq_events
);
9268 static void account_event(struct perf_event
*event
)
9275 if (event
->attach_state
& PERF_ATTACH_TASK
)
9277 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9278 atomic_inc(&nr_mmap_events
);
9279 if (event
->attr
.comm
)
9280 atomic_inc(&nr_comm_events
);
9281 if (event
->attr
.namespaces
)
9282 atomic_inc(&nr_namespaces_events
);
9283 if (event
->attr
.task
)
9284 atomic_inc(&nr_task_events
);
9285 if (event
->attr
.freq
)
9286 account_freq_event();
9287 if (event
->attr
.context_switch
) {
9288 atomic_inc(&nr_switch_events
);
9291 if (has_branch_stack(event
))
9293 if (is_cgroup_event(event
))
9297 if (atomic_inc_not_zero(&perf_sched_count
))
9300 mutex_lock(&perf_sched_mutex
);
9301 if (!atomic_read(&perf_sched_count
)) {
9302 static_branch_enable(&perf_sched_events
);
9304 * Guarantee that all CPUs observe they key change and
9305 * call the perf scheduling hooks before proceeding to
9306 * install events that need them.
9308 synchronize_sched();
9311 * Now that we have waited for the sync_sched(), allow further
9312 * increments to by-pass the mutex.
9314 atomic_inc(&perf_sched_count
);
9315 mutex_unlock(&perf_sched_mutex
);
9319 account_event_cpu(event
, event
->cpu
);
9321 account_pmu_sb_event(event
);
9325 * Allocate and initialize a event structure
9327 static struct perf_event
*
9328 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9329 struct task_struct
*task
,
9330 struct perf_event
*group_leader
,
9331 struct perf_event
*parent_event
,
9332 perf_overflow_handler_t overflow_handler
,
9333 void *context
, int cgroup_fd
)
9336 struct perf_event
*event
;
9337 struct hw_perf_event
*hwc
;
9340 if ((unsigned)cpu
>= nr_cpu_ids
) {
9341 if (!task
|| cpu
!= -1)
9342 return ERR_PTR(-EINVAL
);
9345 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9347 return ERR_PTR(-ENOMEM
);
9350 * Single events are their own group leaders, with an
9351 * empty sibling list:
9354 group_leader
= event
;
9356 mutex_init(&event
->child_mutex
);
9357 INIT_LIST_HEAD(&event
->child_list
);
9359 INIT_LIST_HEAD(&event
->group_entry
);
9360 INIT_LIST_HEAD(&event
->event_entry
);
9361 INIT_LIST_HEAD(&event
->sibling_list
);
9362 INIT_LIST_HEAD(&event
->rb_entry
);
9363 INIT_LIST_HEAD(&event
->active_entry
);
9364 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9365 INIT_HLIST_NODE(&event
->hlist_entry
);
9368 init_waitqueue_head(&event
->waitq
);
9369 init_irq_work(&event
->pending
, perf_pending_event
);
9371 mutex_init(&event
->mmap_mutex
);
9372 raw_spin_lock_init(&event
->addr_filters
.lock
);
9374 atomic_long_set(&event
->refcount
, 1);
9376 event
->attr
= *attr
;
9377 event
->group_leader
= group_leader
;
9381 event
->parent
= parent_event
;
9383 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9384 event
->id
= atomic64_inc_return(&perf_event_id
);
9386 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9389 event
->attach_state
= PERF_ATTACH_TASK
;
9391 * XXX pmu::event_init needs to know what task to account to
9392 * and we cannot use the ctx information because we need the
9393 * pmu before we get a ctx.
9395 event
->hw
.target
= task
;
9398 event
->clock
= &local_clock
;
9400 event
->clock
= parent_event
->clock
;
9402 if (!overflow_handler
&& parent_event
) {
9403 overflow_handler
= parent_event
->overflow_handler
;
9404 context
= parent_event
->overflow_handler_context
;
9405 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9406 if (overflow_handler
== bpf_overflow_handler
) {
9407 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9410 err
= PTR_ERR(prog
);
9414 event
->orig_overflow_handler
=
9415 parent_event
->orig_overflow_handler
;
9420 if (overflow_handler
) {
9421 event
->overflow_handler
= overflow_handler
;
9422 event
->overflow_handler_context
= context
;
9423 } else if (is_write_backward(event
)){
9424 event
->overflow_handler
= perf_event_output_backward
;
9425 event
->overflow_handler_context
= NULL
;
9427 event
->overflow_handler
= perf_event_output_forward
;
9428 event
->overflow_handler_context
= NULL
;
9431 perf_event__state_init(event
);
9436 hwc
->sample_period
= attr
->sample_period
;
9437 if (attr
->freq
&& attr
->sample_freq
)
9438 hwc
->sample_period
= 1;
9439 hwc
->last_period
= hwc
->sample_period
;
9441 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9444 * we currently do not support PERF_FORMAT_GROUP on inherited events
9446 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
9449 if (!has_branch_stack(event
))
9450 event
->attr
.branch_sample_type
= 0;
9452 if (cgroup_fd
!= -1) {
9453 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9458 pmu
= perf_init_event(event
);
9461 else if (IS_ERR(pmu
)) {
9466 err
= exclusive_event_init(event
);
9470 if (has_addr_filter(event
)) {
9471 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9472 sizeof(unsigned long),
9474 if (!event
->addr_filters_offs
)
9477 /* force hw sync on the address filters */
9478 event
->addr_filters_gen
= 1;
9481 if (!event
->parent
) {
9482 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9483 err
= get_callchain_buffers(attr
->sample_max_stack
);
9485 goto err_addr_filters
;
9489 /* symmetric to unaccount_event() in _free_event() */
9490 account_event(event
);
9495 kfree(event
->addr_filters_offs
);
9498 exclusive_event_destroy(event
);
9502 event
->destroy(event
);
9503 module_put(pmu
->module
);
9505 if (is_cgroup_event(event
))
9506 perf_detach_cgroup(event
);
9508 put_pid_ns(event
->ns
);
9511 return ERR_PTR(err
);
9514 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9515 struct perf_event_attr
*attr
)
9520 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9524 * zero the full structure, so that a short copy will be nice.
9526 memset(attr
, 0, sizeof(*attr
));
9528 ret
= get_user(size
, &uattr
->size
);
9532 if (size
> PAGE_SIZE
) /* silly large */
9535 if (!size
) /* abi compat */
9536 size
= PERF_ATTR_SIZE_VER0
;
9538 if (size
< PERF_ATTR_SIZE_VER0
)
9542 * If we're handed a bigger struct than we know of,
9543 * ensure all the unknown bits are 0 - i.e. new
9544 * user-space does not rely on any kernel feature
9545 * extensions we dont know about yet.
9547 if (size
> sizeof(*attr
)) {
9548 unsigned char __user
*addr
;
9549 unsigned char __user
*end
;
9552 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9553 end
= (void __user
*)uattr
+ size
;
9555 for (; addr
< end
; addr
++) {
9556 ret
= get_user(val
, addr
);
9562 size
= sizeof(*attr
);
9565 ret
= copy_from_user(attr
, uattr
, size
);
9569 if (attr
->__reserved_1
)
9572 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9575 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9578 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9579 u64 mask
= attr
->branch_sample_type
;
9581 /* only using defined bits */
9582 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9585 /* at least one branch bit must be set */
9586 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9589 /* propagate priv level, when not set for branch */
9590 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9592 /* exclude_kernel checked on syscall entry */
9593 if (!attr
->exclude_kernel
)
9594 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9596 if (!attr
->exclude_user
)
9597 mask
|= PERF_SAMPLE_BRANCH_USER
;
9599 if (!attr
->exclude_hv
)
9600 mask
|= PERF_SAMPLE_BRANCH_HV
;
9602 * adjust user setting (for HW filter setup)
9604 attr
->branch_sample_type
= mask
;
9606 /* privileged levels capture (kernel, hv): check permissions */
9607 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9608 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9612 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9613 ret
= perf_reg_validate(attr
->sample_regs_user
);
9618 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9619 if (!arch_perf_have_user_stack_dump())
9623 * We have __u32 type for the size, but so far
9624 * we can only use __u16 as maximum due to the
9625 * __u16 sample size limit.
9627 if (attr
->sample_stack_user
>= USHRT_MAX
)
9629 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9633 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9634 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9639 put_user(sizeof(*attr
), &uattr
->size
);
9645 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9647 struct ring_buffer
*rb
= NULL
;
9653 /* don't allow circular references */
9654 if (event
== output_event
)
9658 * Don't allow cross-cpu buffers
9660 if (output_event
->cpu
!= event
->cpu
)
9664 * If its not a per-cpu rb, it must be the same task.
9666 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9670 * Mixing clocks in the same buffer is trouble you don't need.
9672 if (output_event
->clock
!= event
->clock
)
9676 * Either writing ring buffer from beginning or from end.
9677 * Mixing is not allowed.
9679 if (is_write_backward(output_event
) != is_write_backward(event
))
9683 * If both events generate aux data, they must be on the same PMU
9685 if (has_aux(event
) && has_aux(output_event
) &&
9686 event
->pmu
!= output_event
->pmu
)
9690 mutex_lock(&event
->mmap_mutex
);
9691 /* Can't redirect output if we've got an active mmap() */
9692 if (atomic_read(&event
->mmap_count
))
9696 /* get the rb we want to redirect to */
9697 rb
= ring_buffer_get(output_event
);
9702 ring_buffer_attach(event
, rb
);
9706 mutex_unlock(&event
->mmap_mutex
);
9712 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9718 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9721 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9723 bool nmi_safe
= false;
9726 case CLOCK_MONOTONIC
:
9727 event
->clock
= &ktime_get_mono_fast_ns
;
9731 case CLOCK_MONOTONIC_RAW
:
9732 event
->clock
= &ktime_get_raw_fast_ns
;
9736 case CLOCK_REALTIME
:
9737 event
->clock
= &ktime_get_real_ns
;
9740 case CLOCK_BOOTTIME
:
9741 event
->clock
= &ktime_get_boot_ns
;
9745 event
->clock
= &ktime_get_tai_ns
;
9752 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9759 * Variation on perf_event_ctx_lock_nested(), except we take two context
9762 static struct perf_event_context
*
9763 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9764 struct perf_event_context
*ctx
)
9766 struct perf_event_context
*gctx
;
9770 gctx
= READ_ONCE(group_leader
->ctx
);
9771 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9777 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9779 if (group_leader
->ctx
!= gctx
) {
9780 mutex_unlock(&ctx
->mutex
);
9781 mutex_unlock(&gctx
->mutex
);
9790 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9792 * @attr_uptr: event_id type attributes for monitoring/sampling
9795 * @group_fd: group leader event fd
9797 SYSCALL_DEFINE5(perf_event_open
,
9798 struct perf_event_attr __user
*, attr_uptr
,
9799 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9801 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9802 struct perf_event
*event
, *sibling
;
9803 struct perf_event_attr attr
;
9804 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9805 struct file
*event_file
= NULL
;
9806 struct fd group
= {NULL
, 0};
9807 struct task_struct
*task
= NULL
;
9812 int f_flags
= O_RDWR
;
9815 /* for future expandability... */
9816 if (flags
& ~PERF_FLAG_ALL
)
9819 err
= perf_copy_attr(attr_uptr
, &attr
);
9823 if (!attr
.exclude_kernel
) {
9824 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9828 if (attr
.namespaces
) {
9829 if (!capable(CAP_SYS_ADMIN
))
9834 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9837 if (attr
.sample_period
& (1ULL << 63))
9841 if (!attr
.sample_max_stack
)
9842 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9845 * In cgroup mode, the pid argument is used to pass the fd
9846 * opened to the cgroup directory in cgroupfs. The cpu argument
9847 * designates the cpu on which to monitor threads from that
9850 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9853 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9854 f_flags
|= O_CLOEXEC
;
9856 event_fd
= get_unused_fd_flags(f_flags
);
9860 if (group_fd
!= -1) {
9861 err
= perf_fget_light(group_fd
, &group
);
9864 group_leader
= group
.file
->private_data
;
9865 if (flags
& PERF_FLAG_FD_OUTPUT
)
9866 output_event
= group_leader
;
9867 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9868 group_leader
= NULL
;
9871 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9872 task
= find_lively_task_by_vpid(pid
);
9874 err
= PTR_ERR(task
);
9879 if (task
&& group_leader
&&
9880 group_leader
->attr
.inherit
!= attr
.inherit
) {
9888 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
9893 * Reuse ptrace permission checks for now.
9895 * We must hold cred_guard_mutex across this and any potential
9896 * perf_install_in_context() call for this new event to
9897 * serialize against exec() altering our credentials (and the
9898 * perf_event_exit_task() that could imply).
9901 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
9905 if (flags
& PERF_FLAG_PID_CGROUP
)
9908 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
9909 NULL
, NULL
, cgroup_fd
);
9910 if (IS_ERR(event
)) {
9911 err
= PTR_ERR(event
);
9915 if (is_sampling_event(event
)) {
9916 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
9923 * Special case software events and allow them to be part of
9924 * any hardware group.
9928 if (attr
.use_clockid
) {
9929 err
= perf_event_set_clock(event
, attr
.clockid
);
9934 if (pmu
->task_ctx_nr
== perf_sw_context
)
9935 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
9938 (is_software_event(event
) != is_software_event(group_leader
))) {
9939 if (is_software_event(event
)) {
9941 * If event and group_leader are not both a software
9942 * event, and event is, then group leader is not.
9944 * Allow the addition of software events to !software
9945 * groups, this is safe because software events never
9948 pmu
= group_leader
->pmu
;
9949 } else if (is_software_event(group_leader
) &&
9950 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
9952 * In case the group is a pure software group, and we
9953 * try to add a hardware event, move the whole group to
9954 * the hardware context.
9961 * Get the target context (task or percpu):
9963 ctx
= find_get_context(pmu
, task
, event
);
9969 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
9975 * Look up the group leader (we will attach this event to it):
9981 * Do not allow a recursive hierarchy (this new sibling
9982 * becoming part of another group-sibling):
9984 if (group_leader
->group_leader
!= group_leader
)
9987 /* All events in a group should have the same clock */
9988 if (group_leader
->clock
!= event
->clock
)
9992 * Do not allow to attach to a group in a different
9993 * task or CPU context:
9997 * Make sure we're both on the same task, or both
10000 if (group_leader
->ctx
->task
!= ctx
->task
)
10004 * Make sure we're both events for the same CPU;
10005 * grouping events for different CPUs is broken; since
10006 * you can never concurrently schedule them anyhow.
10008 if (group_leader
->cpu
!= event
->cpu
)
10011 if (group_leader
->ctx
!= ctx
)
10016 * Only a group leader can be exclusive or pinned
10018 if (attr
.exclusive
|| attr
.pinned
)
10022 if (output_event
) {
10023 err
= perf_event_set_output(event
, output_event
);
10028 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
10030 if (IS_ERR(event_file
)) {
10031 err
= PTR_ERR(event_file
);
10037 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
10039 if (gctx
->task
== TASK_TOMBSTONE
) {
10045 * Check if we raced against another sys_perf_event_open() call
10046 * moving the software group underneath us.
10048 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10050 * If someone moved the group out from under us, check
10051 * if this new event wound up on the same ctx, if so
10052 * its the regular !move_group case, otherwise fail.
10058 perf_event_ctx_unlock(group_leader
, gctx
);
10063 mutex_lock(&ctx
->mutex
);
10066 if (ctx
->task
== TASK_TOMBSTONE
) {
10071 if (!perf_event_validate_size(event
)) {
10077 * Must be under the same ctx::mutex as perf_install_in_context(),
10078 * because we need to serialize with concurrent event creation.
10080 if (!exclusive_event_installable(event
, ctx
)) {
10081 /* exclusive and group stuff are assumed mutually exclusive */
10082 WARN_ON_ONCE(move_group
);
10088 WARN_ON_ONCE(ctx
->parent_ctx
);
10091 * This is the point on no return; we cannot fail hereafter. This is
10092 * where we start modifying current state.
10097 * See perf_event_ctx_lock() for comments on the details
10098 * of swizzling perf_event::ctx.
10100 perf_remove_from_context(group_leader
, 0);
10103 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10105 perf_remove_from_context(sibling
, 0);
10110 * Wait for everybody to stop referencing the events through
10111 * the old lists, before installing it on new lists.
10116 * Install the group siblings before the group leader.
10118 * Because a group leader will try and install the entire group
10119 * (through the sibling list, which is still in-tact), we can
10120 * end up with siblings installed in the wrong context.
10122 * By installing siblings first we NO-OP because they're not
10123 * reachable through the group lists.
10125 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10127 perf_event__state_init(sibling
);
10128 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
10133 * Removing from the context ends up with disabled
10134 * event. What we want here is event in the initial
10135 * startup state, ready to be add into new context.
10137 perf_event__state_init(group_leader
);
10138 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
10143 * Precalculate sample_data sizes; do while holding ctx::mutex such
10144 * that we're serialized against further additions and before
10145 * perf_install_in_context() which is the point the event is active and
10146 * can use these values.
10148 perf_event__header_size(event
);
10149 perf_event__id_header_size(event
);
10151 event
->owner
= current
;
10153 perf_install_in_context(ctx
, event
, event
->cpu
);
10154 perf_unpin_context(ctx
);
10157 perf_event_ctx_unlock(group_leader
, gctx
);
10158 mutex_unlock(&ctx
->mutex
);
10161 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10162 put_task_struct(task
);
10167 mutex_lock(¤t
->perf_event_mutex
);
10168 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10169 mutex_unlock(¤t
->perf_event_mutex
);
10172 * Drop the reference on the group_event after placing the
10173 * new event on the sibling_list. This ensures destruction
10174 * of the group leader will find the pointer to itself in
10175 * perf_group_detach().
10178 fd_install(event_fd
, event_file
);
10183 perf_event_ctx_unlock(group_leader
, gctx
);
10184 mutex_unlock(&ctx
->mutex
);
10188 perf_unpin_context(ctx
);
10192 * If event_file is set, the fput() above will have called ->release()
10193 * and that will take care of freeing the event.
10199 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10204 put_task_struct(task
);
10208 put_unused_fd(event_fd
);
10213 * perf_event_create_kernel_counter
10215 * @attr: attributes of the counter to create
10216 * @cpu: cpu in which the counter is bound
10217 * @task: task to profile (NULL for percpu)
10219 struct perf_event
*
10220 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10221 struct task_struct
*task
,
10222 perf_overflow_handler_t overflow_handler
,
10225 struct perf_event_context
*ctx
;
10226 struct perf_event
*event
;
10230 * Get the target context (task or percpu):
10233 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10234 overflow_handler
, context
, -1);
10235 if (IS_ERR(event
)) {
10236 err
= PTR_ERR(event
);
10240 /* Mark owner so we could distinguish it from user events. */
10241 event
->owner
= TASK_TOMBSTONE
;
10243 ctx
= find_get_context(event
->pmu
, task
, event
);
10245 err
= PTR_ERR(ctx
);
10249 WARN_ON_ONCE(ctx
->parent_ctx
);
10250 mutex_lock(&ctx
->mutex
);
10251 if (ctx
->task
== TASK_TOMBSTONE
) {
10256 if (!exclusive_event_installable(event
, ctx
)) {
10261 perf_install_in_context(ctx
, event
, cpu
);
10262 perf_unpin_context(ctx
);
10263 mutex_unlock(&ctx
->mutex
);
10268 mutex_unlock(&ctx
->mutex
);
10269 perf_unpin_context(ctx
);
10274 return ERR_PTR(err
);
10276 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10278 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10280 struct perf_event_context
*src_ctx
;
10281 struct perf_event_context
*dst_ctx
;
10282 struct perf_event
*event
, *tmp
;
10285 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10286 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10289 * See perf_event_ctx_lock() for comments on the details
10290 * of swizzling perf_event::ctx.
10292 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10293 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10295 perf_remove_from_context(event
, 0);
10296 unaccount_event_cpu(event
, src_cpu
);
10298 list_add(&event
->migrate_entry
, &events
);
10302 * Wait for the events to quiesce before re-instating them.
10307 * Re-instate events in 2 passes.
10309 * Skip over group leaders and only install siblings on this first
10310 * pass, siblings will not get enabled without a leader, however a
10311 * leader will enable its siblings, even if those are still on the old
10314 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10315 if (event
->group_leader
== event
)
10318 list_del(&event
->migrate_entry
);
10319 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10320 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10321 account_event_cpu(event
, dst_cpu
);
10322 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10327 * Once all the siblings are setup properly, install the group leaders
10330 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10331 list_del(&event
->migrate_entry
);
10332 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10333 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10334 account_event_cpu(event
, dst_cpu
);
10335 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10338 mutex_unlock(&dst_ctx
->mutex
);
10339 mutex_unlock(&src_ctx
->mutex
);
10341 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10343 static void sync_child_event(struct perf_event
*child_event
,
10344 struct task_struct
*child
)
10346 struct perf_event
*parent_event
= child_event
->parent
;
10349 if (child_event
->attr
.inherit_stat
)
10350 perf_event_read_event(child_event
, child
);
10352 child_val
= perf_event_count(child_event
);
10355 * Add back the child's count to the parent's count:
10357 atomic64_add(child_val
, &parent_event
->child_count
);
10358 atomic64_add(child_event
->total_time_enabled
,
10359 &parent_event
->child_total_time_enabled
);
10360 atomic64_add(child_event
->total_time_running
,
10361 &parent_event
->child_total_time_running
);
10365 perf_event_exit_event(struct perf_event
*child_event
,
10366 struct perf_event_context
*child_ctx
,
10367 struct task_struct
*child
)
10369 struct perf_event
*parent_event
= child_event
->parent
;
10372 * Do not destroy the 'original' grouping; because of the context
10373 * switch optimization the original events could've ended up in a
10374 * random child task.
10376 * If we were to destroy the original group, all group related
10377 * operations would cease to function properly after this random
10380 * Do destroy all inherited groups, we don't care about those
10381 * and being thorough is better.
10383 raw_spin_lock_irq(&child_ctx
->lock
);
10384 WARN_ON_ONCE(child_ctx
->is_active
);
10387 perf_group_detach(child_event
);
10388 list_del_event(child_event
, child_ctx
);
10389 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
10390 raw_spin_unlock_irq(&child_ctx
->lock
);
10393 * Parent events are governed by their filedesc, retain them.
10395 if (!parent_event
) {
10396 perf_event_wakeup(child_event
);
10400 * Child events can be cleaned up.
10403 sync_child_event(child_event
, child
);
10406 * Remove this event from the parent's list
10408 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10409 mutex_lock(&parent_event
->child_mutex
);
10410 list_del_init(&child_event
->child_list
);
10411 mutex_unlock(&parent_event
->child_mutex
);
10414 * Kick perf_poll() for is_event_hup().
10416 perf_event_wakeup(parent_event
);
10417 free_event(child_event
);
10418 put_event(parent_event
);
10421 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10423 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10424 struct perf_event
*child_event
, *next
;
10426 WARN_ON_ONCE(child
!= current
);
10428 child_ctx
= perf_pin_task_context(child
, ctxn
);
10433 * In order to reduce the amount of tricky in ctx tear-down, we hold
10434 * ctx::mutex over the entire thing. This serializes against almost
10435 * everything that wants to access the ctx.
10437 * The exception is sys_perf_event_open() /
10438 * perf_event_create_kernel_count() which does find_get_context()
10439 * without ctx::mutex (it cannot because of the move_group double mutex
10440 * lock thing). See the comments in perf_install_in_context().
10442 mutex_lock(&child_ctx
->mutex
);
10445 * In a single ctx::lock section, de-schedule the events and detach the
10446 * context from the task such that we cannot ever get it scheduled back
10449 raw_spin_lock_irq(&child_ctx
->lock
);
10450 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
10453 * Now that the context is inactive, destroy the task <-> ctx relation
10454 * and mark the context dead.
10456 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10457 put_ctx(child_ctx
); /* cannot be last */
10458 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10459 put_task_struct(current
); /* cannot be last */
10461 clone_ctx
= unclone_ctx(child_ctx
);
10462 raw_spin_unlock_irq(&child_ctx
->lock
);
10465 put_ctx(clone_ctx
);
10468 * Report the task dead after unscheduling the events so that we
10469 * won't get any samples after PERF_RECORD_EXIT. We can however still
10470 * get a few PERF_RECORD_READ events.
10472 perf_event_task(child
, child_ctx
, 0);
10474 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10475 perf_event_exit_event(child_event
, child_ctx
, child
);
10477 mutex_unlock(&child_ctx
->mutex
);
10479 put_ctx(child_ctx
);
10483 * When a child task exits, feed back event values to parent events.
10485 * Can be called with cred_guard_mutex held when called from
10486 * install_exec_creds().
10488 void perf_event_exit_task(struct task_struct
*child
)
10490 struct perf_event
*event
, *tmp
;
10493 mutex_lock(&child
->perf_event_mutex
);
10494 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10496 list_del_init(&event
->owner_entry
);
10499 * Ensure the list deletion is visible before we clear
10500 * the owner, closes a race against perf_release() where
10501 * we need to serialize on the owner->perf_event_mutex.
10503 smp_store_release(&event
->owner
, NULL
);
10505 mutex_unlock(&child
->perf_event_mutex
);
10507 for_each_task_context_nr(ctxn
)
10508 perf_event_exit_task_context(child
, ctxn
);
10511 * The perf_event_exit_task_context calls perf_event_task
10512 * with child's task_ctx, which generates EXIT events for
10513 * child contexts and sets child->perf_event_ctxp[] to NULL.
10514 * At this point we need to send EXIT events to cpu contexts.
10516 perf_event_task(child
, NULL
, 0);
10519 static void perf_free_event(struct perf_event
*event
,
10520 struct perf_event_context
*ctx
)
10522 struct perf_event
*parent
= event
->parent
;
10524 if (WARN_ON_ONCE(!parent
))
10527 mutex_lock(&parent
->child_mutex
);
10528 list_del_init(&event
->child_list
);
10529 mutex_unlock(&parent
->child_mutex
);
10533 raw_spin_lock_irq(&ctx
->lock
);
10534 perf_group_detach(event
);
10535 list_del_event(event
, ctx
);
10536 raw_spin_unlock_irq(&ctx
->lock
);
10541 * Free an unexposed, unused context as created by inheritance by
10542 * perf_event_init_task below, used by fork() in case of fail.
10544 * Not all locks are strictly required, but take them anyway to be nice and
10545 * help out with the lockdep assertions.
10547 void perf_event_free_task(struct task_struct
*task
)
10549 struct perf_event_context
*ctx
;
10550 struct perf_event
*event
, *tmp
;
10553 for_each_task_context_nr(ctxn
) {
10554 ctx
= task
->perf_event_ctxp
[ctxn
];
10558 mutex_lock(&ctx
->mutex
);
10559 raw_spin_lock_irq(&ctx
->lock
);
10561 * Destroy the task <-> ctx relation and mark the context dead.
10563 * This is important because even though the task hasn't been
10564 * exposed yet the context has been (through child_list).
10566 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
10567 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
10568 put_task_struct(task
); /* cannot be last */
10569 raw_spin_unlock_irq(&ctx
->lock
);
10571 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
10572 perf_free_event(event
, ctx
);
10574 mutex_unlock(&ctx
->mutex
);
10579 void perf_event_delayed_put(struct task_struct
*task
)
10583 for_each_task_context_nr(ctxn
)
10584 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10587 struct file
*perf_event_get(unsigned int fd
)
10591 file
= fget_raw(fd
);
10593 return ERR_PTR(-EBADF
);
10595 if (file
->f_op
!= &perf_fops
) {
10597 return ERR_PTR(-EBADF
);
10603 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10606 return ERR_PTR(-EINVAL
);
10608 return &event
->attr
;
10612 * Inherit a event from parent task to child task.
10615 * - valid pointer on success
10616 * - NULL for orphaned events
10617 * - IS_ERR() on error
10619 static struct perf_event
*
10620 inherit_event(struct perf_event
*parent_event
,
10621 struct task_struct
*parent
,
10622 struct perf_event_context
*parent_ctx
,
10623 struct task_struct
*child
,
10624 struct perf_event
*group_leader
,
10625 struct perf_event_context
*child_ctx
)
10627 enum perf_event_active_state parent_state
= parent_event
->state
;
10628 struct perf_event
*child_event
;
10629 unsigned long flags
;
10632 * Instead of creating recursive hierarchies of events,
10633 * we link inherited events back to the original parent,
10634 * which has a filp for sure, which we use as the reference
10637 if (parent_event
->parent
)
10638 parent_event
= parent_event
->parent
;
10640 child_event
= perf_event_alloc(&parent_event
->attr
,
10643 group_leader
, parent_event
,
10645 if (IS_ERR(child_event
))
10646 return child_event
;
10649 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10650 * must be under the same lock in order to serialize against
10651 * perf_event_release_kernel(), such that either we must observe
10652 * is_orphaned_event() or they will observe us on the child_list.
10654 mutex_lock(&parent_event
->child_mutex
);
10655 if (is_orphaned_event(parent_event
) ||
10656 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10657 mutex_unlock(&parent_event
->child_mutex
);
10658 free_event(child_event
);
10662 get_ctx(child_ctx
);
10665 * Make the child state follow the state of the parent event,
10666 * not its attr.disabled bit. We hold the parent's mutex,
10667 * so we won't race with perf_event_{en, dis}able_family.
10669 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10670 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10672 child_event
->state
= PERF_EVENT_STATE_OFF
;
10674 if (parent_event
->attr
.freq
) {
10675 u64 sample_period
= parent_event
->hw
.sample_period
;
10676 struct hw_perf_event
*hwc
= &child_event
->hw
;
10678 hwc
->sample_period
= sample_period
;
10679 hwc
->last_period
= sample_period
;
10681 local64_set(&hwc
->period_left
, sample_period
);
10684 child_event
->ctx
= child_ctx
;
10685 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10686 child_event
->overflow_handler_context
10687 = parent_event
->overflow_handler_context
;
10690 * Precalculate sample_data sizes
10692 perf_event__header_size(child_event
);
10693 perf_event__id_header_size(child_event
);
10696 * Link it up in the child's context:
10698 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10699 add_event_to_ctx(child_event
, child_ctx
);
10700 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10703 * Link this into the parent event's child list
10705 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10706 mutex_unlock(&parent_event
->child_mutex
);
10708 return child_event
;
10712 * Inherits an event group.
10714 * This will quietly suppress orphaned events; !inherit_event() is not an error.
10715 * This matches with perf_event_release_kernel() removing all child events.
10721 static int inherit_group(struct perf_event
*parent_event
,
10722 struct task_struct
*parent
,
10723 struct perf_event_context
*parent_ctx
,
10724 struct task_struct
*child
,
10725 struct perf_event_context
*child_ctx
)
10727 struct perf_event
*leader
;
10728 struct perf_event
*sub
;
10729 struct perf_event
*child_ctr
;
10731 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10732 child
, NULL
, child_ctx
);
10733 if (IS_ERR(leader
))
10734 return PTR_ERR(leader
);
10736 * @leader can be NULL here because of is_orphaned_event(). In this
10737 * case inherit_event() will create individual events, similar to what
10738 * perf_group_detach() would do anyway.
10740 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10741 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10742 child
, leader
, child_ctx
);
10743 if (IS_ERR(child_ctr
))
10744 return PTR_ERR(child_ctr
);
10750 * Creates the child task context and tries to inherit the event-group.
10752 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
10753 * inherited_all set when we 'fail' to inherit an orphaned event; this is
10754 * consistent with perf_event_release_kernel() removing all child events.
10761 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10762 struct perf_event_context
*parent_ctx
,
10763 struct task_struct
*child
, int ctxn
,
10764 int *inherited_all
)
10767 struct perf_event_context
*child_ctx
;
10769 if (!event
->attr
.inherit
) {
10770 *inherited_all
= 0;
10774 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10777 * This is executed from the parent task context, so
10778 * inherit events that have been marked for cloning.
10779 * First allocate and initialize a context for the
10782 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10786 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10789 ret
= inherit_group(event
, parent
, parent_ctx
,
10793 *inherited_all
= 0;
10799 * Initialize the perf_event context in task_struct
10801 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10803 struct perf_event_context
*child_ctx
, *parent_ctx
;
10804 struct perf_event_context
*cloned_ctx
;
10805 struct perf_event
*event
;
10806 struct task_struct
*parent
= current
;
10807 int inherited_all
= 1;
10808 unsigned long flags
;
10811 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10815 * If the parent's context is a clone, pin it so it won't get
10816 * swapped under us.
10818 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10823 * No need to check if parent_ctx != NULL here; since we saw
10824 * it non-NULL earlier, the only reason for it to become NULL
10825 * is if we exit, and since we're currently in the middle of
10826 * a fork we can't be exiting at the same time.
10830 * Lock the parent list. No need to lock the child - not PID
10831 * hashed yet and not running, so nobody can access it.
10833 mutex_lock(&parent_ctx
->mutex
);
10836 * We dont have to disable NMIs - we are only looking at
10837 * the list, not manipulating it:
10839 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10840 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10841 child
, ctxn
, &inherited_all
);
10847 * We can't hold ctx->lock when iterating the ->flexible_group list due
10848 * to allocations, but we need to prevent rotation because
10849 * rotate_ctx() will change the list from interrupt context.
10851 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10852 parent_ctx
->rotate_disable
= 1;
10853 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10855 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10856 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10857 child
, ctxn
, &inherited_all
);
10862 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10863 parent_ctx
->rotate_disable
= 0;
10865 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10867 if (child_ctx
&& inherited_all
) {
10869 * Mark the child context as a clone of the parent
10870 * context, or of whatever the parent is a clone of.
10872 * Note that if the parent is a clone, the holding of
10873 * parent_ctx->lock avoids it from being uncloned.
10875 cloned_ctx
= parent_ctx
->parent_ctx
;
10877 child_ctx
->parent_ctx
= cloned_ctx
;
10878 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
10880 child_ctx
->parent_ctx
= parent_ctx
;
10881 child_ctx
->parent_gen
= parent_ctx
->generation
;
10883 get_ctx(child_ctx
->parent_ctx
);
10886 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10888 mutex_unlock(&parent_ctx
->mutex
);
10890 perf_unpin_context(parent_ctx
);
10891 put_ctx(parent_ctx
);
10897 * Initialize the perf_event context in task_struct
10899 int perf_event_init_task(struct task_struct
*child
)
10903 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
10904 mutex_init(&child
->perf_event_mutex
);
10905 INIT_LIST_HEAD(&child
->perf_event_list
);
10907 for_each_task_context_nr(ctxn
) {
10908 ret
= perf_event_init_context(child
, ctxn
);
10910 perf_event_free_task(child
);
10918 static void __init
perf_event_init_all_cpus(void)
10920 struct swevent_htable
*swhash
;
10923 for_each_possible_cpu(cpu
) {
10924 swhash
= &per_cpu(swevent_htable
, cpu
);
10925 mutex_init(&swhash
->hlist_mutex
);
10926 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
10928 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
10929 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
10931 #ifdef CONFIG_CGROUP_PERF
10932 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
10934 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
10938 int perf_event_init_cpu(unsigned int cpu
)
10940 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
10942 mutex_lock(&swhash
->hlist_mutex
);
10943 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
10944 struct swevent_hlist
*hlist
;
10946 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
10948 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
10950 mutex_unlock(&swhash
->hlist_mutex
);
10954 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
10955 static void __perf_event_exit_context(void *__info
)
10957 struct perf_event_context
*ctx
= __info
;
10958 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
10959 struct perf_event
*event
;
10961 raw_spin_lock(&ctx
->lock
);
10962 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
10963 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
10964 raw_spin_unlock(&ctx
->lock
);
10967 static void perf_event_exit_cpu_context(int cpu
)
10969 struct perf_event_context
*ctx
;
10973 idx
= srcu_read_lock(&pmus_srcu
);
10974 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
10975 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
10977 mutex_lock(&ctx
->mutex
);
10978 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
10979 mutex_unlock(&ctx
->mutex
);
10981 srcu_read_unlock(&pmus_srcu
, idx
);
10985 static void perf_event_exit_cpu_context(int cpu
) { }
10989 int perf_event_exit_cpu(unsigned int cpu
)
10991 perf_event_exit_cpu_context(cpu
);
10996 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
11000 for_each_online_cpu(cpu
)
11001 perf_event_exit_cpu(cpu
);
11007 * Run the perf reboot notifier at the very last possible moment so that
11008 * the generic watchdog code runs as long as possible.
11010 static struct notifier_block perf_reboot_notifier
= {
11011 .notifier_call
= perf_reboot
,
11012 .priority
= INT_MIN
,
11015 void __init
perf_event_init(void)
11019 idr_init(&pmu_idr
);
11021 perf_event_init_all_cpus();
11022 init_srcu_struct(&pmus_srcu
);
11023 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
11024 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
11025 perf_pmu_register(&perf_task_clock
, NULL
, -1);
11026 perf_tp_register();
11027 perf_event_init_cpu(smp_processor_id());
11028 register_reboot_notifier(&perf_reboot_notifier
);
11030 ret
= init_hw_breakpoint();
11031 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
11034 * Build time assertion that we keep the data_head at the intended
11035 * location. IOW, validation we got the __reserved[] size right.
11037 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
11041 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
11044 struct perf_pmu_events_attr
*pmu_attr
=
11045 container_of(attr
, struct perf_pmu_events_attr
, attr
);
11047 if (pmu_attr
->event_str
)
11048 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
11052 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
11054 static int __init
perf_event_sysfs_init(void)
11059 mutex_lock(&pmus_lock
);
11061 ret
= bus_register(&pmu_bus
);
11065 list_for_each_entry(pmu
, &pmus
, entry
) {
11066 if (!pmu
->name
|| pmu
->type
< 0)
11069 ret
= pmu_dev_alloc(pmu
);
11070 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
11072 pmu_bus_running
= 1;
11076 mutex_unlock(&pmus_lock
);
11080 device_initcall(perf_event_sysfs_init
);
11082 #ifdef CONFIG_CGROUP_PERF
11083 static struct cgroup_subsys_state
*
11084 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
11086 struct perf_cgroup
*jc
;
11088 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
11090 return ERR_PTR(-ENOMEM
);
11092 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
11095 return ERR_PTR(-ENOMEM
);
11101 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
11103 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
11105 free_percpu(jc
->info
);
11109 static int __perf_cgroup_move(void *info
)
11111 struct task_struct
*task
= info
;
11113 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
11118 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
11120 struct task_struct
*task
;
11121 struct cgroup_subsys_state
*css
;
11123 cgroup_taskset_for_each(task
, css
, tset
)
11124 task_function_call(task
, __perf_cgroup_move
, task
);
11127 struct cgroup_subsys perf_event_cgrp_subsys
= {
11128 .css_alloc
= perf_cgroup_css_alloc
,
11129 .css_free
= perf_cgroup_css_free
,
11130 .attach
= perf_cgroup_attach
,
11132 * Implicitly enable on dfl hierarchy so that perf events can
11133 * always be filtered by cgroup2 path as long as perf_event
11134 * controller is not mounted on a legacy hierarchy.
11136 .implicit_on_dfl
= true,
11138 #endif /* CONFIG_CGROUP_PERF */