2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
47 #include <linux/namei.h>
48 #include <linux/parser.h>
49 #include <linux/sched/clock.h>
50 #include <linux/sched/mm.h>
51 #include <linux/proc_ns.h>
52 #include <linux/mount.h>
56 #include <asm/irq_regs.h>
58 typedef int (*remote_function_f
)(void *);
60 struct remote_function_call
{
61 struct task_struct
*p
;
62 remote_function_f func
;
67 static void remote_function(void *data
)
69 struct remote_function_call
*tfc
= data
;
70 struct task_struct
*p
= tfc
->p
;
74 if (task_cpu(p
) != smp_processor_id())
78 * Now that we're on right CPU with IRQs disabled, we can test
79 * if we hit the right task without races.
82 tfc
->ret
= -ESRCH
; /* No such (running) process */
87 tfc
->ret
= tfc
->func(tfc
->info
);
91 * task_function_call - call a function on the cpu on which a task runs
92 * @p: the task to evaluate
93 * @func: the function to be called
94 * @info: the function call argument
96 * Calls the function @func when the task is currently running. This might
97 * be on the current CPU, which just calls the function directly
99 * returns: @func return value, or
100 * -ESRCH - when the process isn't running
101 * -EAGAIN - when the process moved away
104 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
106 struct remote_function_call data
= {
115 ret
= smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
118 } while (ret
== -EAGAIN
);
124 * cpu_function_call - call a function on the cpu
125 * @func: the function to be called
126 * @info: the function call argument
128 * Calls the function @func on the remote cpu.
130 * returns: @func return value or -ENXIO when the cpu is offline
132 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
134 struct remote_function_call data
= {
138 .ret
= -ENXIO
, /* No such CPU */
141 smp_call_function_single(cpu
, remote_function
, &data
, 1);
146 static inline struct perf_cpu_context
*
147 __get_cpu_context(struct perf_event_context
*ctx
)
149 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
152 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
153 struct perf_event_context
*ctx
)
155 raw_spin_lock(&cpuctx
->ctx
.lock
);
157 raw_spin_lock(&ctx
->lock
);
160 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
161 struct perf_event_context
*ctx
)
164 raw_spin_unlock(&ctx
->lock
);
165 raw_spin_unlock(&cpuctx
->ctx
.lock
);
168 #define TASK_TOMBSTONE ((void *)-1L)
170 static bool is_kernel_event(struct perf_event
*event
)
172 return READ_ONCE(event
->owner
) == TASK_TOMBSTONE
;
176 * On task ctx scheduling...
178 * When !ctx->nr_events a task context will not be scheduled. This means
179 * we can disable the scheduler hooks (for performance) without leaving
180 * pending task ctx state.
182 * This however results in two special cases:
184 * - removing the last event from a task ctx; this is relatively straight
185 * forward and is done in __perf_remove_from_context.
187 * - adding the first event to a task ctx; this is tricky because we cannot
188 * rely on ctx->is_active and therefore cannot use event_function_call().
189 * See perf_install_in_context().
191 * If ctx->nr_events, then ctx->is_active and cpuctx->task_ctx are set.
194 typedef void (*event_f
)(struct perf_event
*, struct perf_cpu_context
*,
195 struct perf_event_context
*, void *);
197 struct event_function_struct
{
198 struct perf_event
*event
;
203 static int event_function(void *info
)
205 struct event_function_struct
*efs
= info
;
206 struct perf_event
*event
= efs
->event
;
207 struct perf_event_context
*ctx
= event
->ctx
;
208 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
209 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
212 WARN_ON_ONCE(!irqs_disabled());
214 perf_ctx_lock(cpuctx
, task_ctx
);
216 * Since we do the IPI call without holding ctx->lock things can have
217 * changed, double check we hit the task we set out to hit.
220 if (ctx
->task
!= current
) {
226 * We only use event_function_call() on established contexts,
227 * and event_function() is only ever called when active (or
228 * rather, we'll have bailed in task_function_call() or the
229 * above ctx->task != current test), therefore we must have
230 * ctx->is_active here.
232 WARN_ON_ONCE(!ctx
->is_active
);
234 * And since we have ctx->is_active, cpuctx->task_ctx must
237 WARN_ON_ONCE(task_ctx
!= ctx
);
239 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
242 efs
->func(event
, cpuctx
, ctx
, efs
->data
);
244 perf_ctx_unlock(cpuctx
, task_ctx
);
249 static void event_function_call(struct perf_event
*event
, event_f func
, void *data
)
251 struct perf_event_context
*ctx
= event
->ctx
;
252 struct task_struct
*task
= READ_ONCE(ctx
->task
); /* verified in event_function */
253 struct event_function_struct efs
= {
259 if (!event
->parent
) {
261 * If this is a !child event, we must hold ctx::mutex to
262 * stabilize the the event->ctx relation. See
263 * perf_event_ctx_lock().
265 lockdep_assert_held(&ctx
->mutex
);
269 cpu_function_call(event
->cpu
, event_function
, &efs
);
273 if (task
== TASK_TOMBSTONE
)
277 if (!task_function_call(task
, event_function
, &efs
))
280 raw_spin_lock_irq(&ctx
->lock
);
282 * Reload the task pointer, it might have been changed by
283 * a concurrent perf_event_context_sched_out().
286 if (task
== TASK_TOMBSTONE
) {
287 raw_spin_unlock_irq(&ctx
->lock
);
290 if (ctx
->is_active
) {
291 raw_spin_unlock_irq(&ctx
->lock
);
294 func(event
, NULL
, ctx
, data
);
295 raw_spin_unlock_irq(&ctx
->lock
);
299 * Similar to event_function_call() + event_function(), but hard assumes IRQs
300 * are already disabled and we're on the right CPU.
302 static void event_function_local(struct perf_event
*event
, event_f func
, void *data
)
304 struct perf_event_context
*ctx
= event
->ctx
;
305 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
306 struct task_struct
*task
= READ_ONCE(ctx
->task
);
307 struct perf_event_context
*task_ctx
= NULL
;
309 WARN_ON_ONCE(!irqs_disabled());
312 if (task
== TASK_TOMBSTONE
)
318 perf_ctx_lock(cpuctx
, task_ctx
);
321 if (task
== TASK_TOMBSTONE
)
326 * We must be either inactive or active and the right task,
327 * otherwise we're screwed, since we cannot IPI to somewhere
330 if (ctx
->is_active
) {
331 if (WARN_ON_ONCE(task
!= current
))
334 if (WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
))
338 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
);
341 func(event
, cpuctx
, ctx
, data
);
343 perf_ctx_unlock(cpuctx
, task_ctx
);
346 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
347 PERF_FLAG_FD_OUTPUT |\
348 PERF_FLAG_PID_CGROUP |\
349 PERF_FLAG_FD_CLOEXEC)
352 * branch priv levels that need permission checks
354 #define PERF_SAMPLE_BRANCH_PERM_PLM \
355 (PERF_SAMPLE_BRANCH_KERNEL |\
356 PERF_SAMPLE_BRANCH_HV)
359 EVENT_FLEXIBLE
= 0x1,
362 /* see ctx_resched() for details */
364 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
368 * perf_sched_events : >0 events exist
369 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
372 static void perf_sched_delayed(struct work_struct
*work
);
373 DEFINE_STATIC_KEY_FALSE(perf_sched_events
);
374 static DECLARE_DELAYED_WORK(perf_sched_work
, perf_sched_delayed
);
375 static DEFINE_MUTEX(perf_sched_mutex
);
376 static atomic_t perf_sched_count
;
378 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
379 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
380 static DEFINE_PER_CPU(struct pmu_event_list
, pmu_sb_events
);
382 static atomic_t nr_mmap_events __read_mostly
;
383 static atomic_t nr_comm_events __read_mostly
;
384 static atomic_t nr_namespaces_events __read_mostly
;
385 static atomic_t nr_task_events __read_mostly
;
386 static atomic_t nr_freq_events __read_mostly
;
387 static atomic_t nr_switch_events __read_mostly
;
389 static LIST_HEAD(pmus
);
390 static DEFINE_MUTEX(pmus_lock
);
391 static struct srcu_struct pmus_srcu
;
392 static cpumask_var_t perf_online_mask
;
395 * perf event paranoia level:
396 * -1 - not paranoid at all
397 * 0 - disallow raw tracepoint access for unpriv
398 * 1 - disallow cpu events for unpriv
399 * 2 - disallow kernel profiling for unpriv
401 int sysctl_perf_event_paranoid __read_mostly
= 2;
403 /* Minimum for 512 kiB + 1 user control page */
404 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
407 * max perf event sample rate
409 #define DEFAULT_MAX_SAMPLE_RATE 100000
410 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
411 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
413 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
415 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
416 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
418 static int perf_sample_allowed_ns __read_mostly
=
419 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
421 static void update_perf_cpu_limits(void)
423 u64 tmp
= perf_sample_period_ns
;
425 tmp
*= sysctl_perf_cpu_time_max_percent
;
426 tmp
= div_u64(tmp
, 100);
430 WRITE_ONCE(perf_sample_allowed_ns
, tmp
);
433 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
435 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
436 void __user
*buffer
, size_t *lenp
,
439 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
445 * If throttling is disabled don't allow the write:
447 if (sysctl_perf_cpu_time_max_percent
== 100 ||
448 sysctl_perf_cpu_time_max_percent
== 0)
451 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
452 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
453 update_perf_cpu_limits();
458 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
460 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
461 void __user
*buffer
, size_t *lenp
,
464 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
469 if (sysctl_perf_cpu_time_max_percent
== 100 ||
470 sysctl_perf_cpu_time_max_percent
== 0) {
472 "perf: Dynamic interrupt throttling disabled, can hang your system!\n");
473 WRITE_ONCE(perf_sample_allowed_ns
, 0);
475 update_perf_cpu_limits();
482 * perf samples are done in some very critical code paths (NMIs).
483 * If they take too much CPU time, the system can lock up and not
484 * get any real work done. This will drop the sample rate when
485 * we detect that events are taking too long.
487 #define NR_ACCUMULATED_SAMPLES 128
488 static DEFINE_PER_CPU(u64
, running_sample_length
);
490 static u64 __report_avg
;
491 static u64 __report_allowed
;
493 static void perf_duration_warn(struct irq_work
*w
)
495 printk_ratelimited(KERN_INFO
496 "perf: interrupt took too long (%lld > %lld), lowering "
497 "kernel.perf_event_max_sample_rate to %d\n",
498 __report_avg
, __report_allowed
,
499 sysctl_perf_event_sample_rate
);
502 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
504 void perf_sample_event_took(u64 sample_len_ns
)
506 u64 max_len
= READ_ONCE(perf_sample_allowed_ns
);
514 /* Decay the counter by 1 average sample. */
515 running_len
= __this_cpu_read(running_sample_length
);
516 running_len
-= running_len
/NR_ACCUMULATED_SAMPLES
;
517 running_len
+= sample_len_ns
;
518 __this_cpu_write(running_sample_length
, running_len
);
521 * Note: this will be biased artifically low until we have
522 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
523 * from having to maintain a count.
525 avg_len
= running_len
/NR_ACCUMULATED_SAMPLES
;
526 if (avg_len
<= max_len
)
529 __report_avg
= avg_len
;
530 __report_allowed
= max_len
;
533 * Compute a throttle threshold 25% below the current duration.
535 avg_len
+= avg_len
/ 4;
536 max
= (TICK_NSEC
/ 100) * sysctl_perf_cpu_time_max_percent
;
542 WRITE_ONCE(perf_sample_allowed_ns
, avg_len
);
543 WRITE_ONCE(max_samples_per_tick
, max
);
545 sysctl_perf_event_sample_rate
= max
* HZ
;
546 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
548 if (!irq_work_queue(&perf_duration_work
)) {
549 early_printk("perf: interrupt took too long (%lld > %lld), lowering "
550 "kernel.perf_event_max_sample_rate to %d\n",
551 __report_avg
, __report_allowed
,
552 sysctl_perf_event_sample_rate
);
556 static atomic64_t perf_event_id
;
558 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
559 enum event_type_t event_type
);
561 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
562 enum event_type_t event_type
,
563 struct task_struct
*task
);
565 static void update_context_time(struct perf_event_context
*ctx
);
566 static u64
perf_event_time(struct perf_event
*event
);
568 void __weak
perf_event_print_debug(void) { }
570 extern __weak
const char *perf_pmu_name(void)
575 static inline u64
perf_clock(void)
577 return local_clock();
580 static inline u64
perf_event_clock(struct perf_event
*event
)
582 return event
->clock();
585 #ifdef CONFIG_CGROUP_PERF
588 perf_cgroup_match(struct perf_event
*event
)
590 struct perf_event_context
*ctx
= event
->ctx
;
591 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
593 /* @event doesn't care about cgroup */
597 /* wants specific cgroup scope but @cpuctx isn't associated with any */
602 * Cgroup scoping is recursive. An event enabled for a cgroup is
603 * also enabled for all its descendant cgroups. If @cpuctx's
604 * cgroup is a descendant of @event's (the test covers identity
605 * case), it's a match.
607 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
608 event
->cgrp
->css
.cgroup
);
611 static inline void perf_detach_cgroup(struct perf_event
*event
)
613 css_put(&event
->cgrp
->css
);
617 static inline int is_cgroup_event(struct perf_event
*event
)
619 return event
->cgrp
!= NULL
;
622 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
624 struct perf_cgroup_info
*t
;
626 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
630 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
632 struct perf_cgroup_info
*info
;
637 info
= this_cpu_ptr(cgrp
->info
);
639 info
->time
+= now
- info
->timestamp
;
640 info
->timestamp
= now
;
643 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
645 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
647 __update_cgrp_time(cgrp_out
);
650 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
652 struct perf_cgroup
*cgrp
;
655 * ensure we access cgroup data only when needed and
656 * when we know the cgroup is pinned (css_get)
658 if (!is_cgroup_event(event
))
661 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
663 * Do not update time when cgroup is not active
665 if (cgrp
== event
->cgrp
)
666 __update_cgrp_time(event
->cgrp
);
670 perf_cgroup_set_timestamp(struct task_struct
*task
,
671 struct perf_event_context
*ctx
)
673 struct perf_cgroup
*cgrp
;
674 struct perf_cgroup_info
*info
;
677 * ctx->lock held by caller
678 * ensure we do not access cgroup data
679 * unless we have the cgroup pinned (css_get)
681 if (!task
|| !ctx
->nr_cgroups
)
684 cgrp
= perf_cgroup_from_task(task
, ctx
);
685 info
= this_cpu_ptr(cgrp
->info
);
686 info
->timestamp
= ctx
->timestamp
;
689 static DEFINE_PER_CPU(struct list_head
, cgrp_cpuctx_list
);
691 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
692 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
695 * reschedule events based on the cgroup constraint of task.
697 * mode SWOUT : schedule out everything
698 * mode SWIN : schedule in based on cgroup for next
700 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
702 struct perf_cpu_context
*cpuctx
;
703 struct list_head
*list
;
707 * Disable interrupts and preemption to avoid this CPU's
708 * cgrp_cpuctx_entry to change under us.
710 local_irq_save(flags
);
712 list
= this_cpu_ptr(&cgrp_cpuctx_list
);
713 list_for_each_entry(cpuctx
, list
, cgrp_cpuctx_entry
) {
714 WARN_ON_ONCE(cpuctx
->ctx
.nr_cgroups
== 0);
716 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
717 perf_pmu_disable(cpuctx
->ctx
.pmu
);
719 if (mode
& PERF_CGROUP_SWOUT
) {
720 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
722 * must not be done before ctxswout due
723 * to event_filter_match() in event_sched_out()
728 if (mode
& PERF_CGROUP_SWIN
) {
729 WARN_ON_ONCE(cpuctx
->cgrp
);
731 * set cgrp before ctxsw in to allow
732 * event_filter_match() to not have to pass
734 * we pass the cpuctx->ctx to perf_cgroup_from_task()
735 * because cgorup events are only per-cpu
737 cpuctx
->cgrp
= perf_cgroup_from_task(task
,
739 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
741 perf_pmu_enable(cpuctx
->ctx
.pmu
);
742 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
745 local_irq_restore(flags
);
748 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
749 struct task_struct
*next
)
751 struct perf_cgroup
*cgrp1
;
752 struct perf_cgroup
*cgrp2
= NULL
;
756 * we come here when we know perf_cgroup_events > 0
757 * we do not need to pass the ctx here because we know
758 * we are holding the rcu lock
760 cgrp1
= perf_cgroup_from_task(task
, NULL
);
761 cgrp2
= perf_cgroup_from_task(next
, NULL
);
764 * only schedule out current cgroup events if we know
765 * that we are switching to a different cgroup. Otherwise,
766 * do no touch the cgroup events.
769 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
774 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
775 struct task_struct
*task
)
777 struct perf_cgroup
*cgrp1
;
778 struct perf_cgroup
*cgrp2
= NULL
;
782 * we come here when we know perf_cgroup_events > 0
783 * we do not need to pass the ctx here because we know
784 * we are holding the rcu lock
786 cgrp1
= perf_cgroup_from_task(task
, NULL
);
787 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
790 * only need to schedule in cgroup events if we are changing
791 * cgroup during ctxsw. Cgroup events were not scheduled
792 * out of ctxsw out if that was not the case.
795 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
800 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
801 struct perf_event_attr
*attr
,
802 struct perf_event
*group_leader
)
804 struct perf_cgroup
*cgrp
;
805 struct cgroup_subsys_state
*css
;
806 struct fd f
= fdget(fd
);
812 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
813 &perf_event_cgrp_subsys
);
819 cgrp
= container_of(css
, struct perf_cgroup
, css
);
823 * all events in a group must monitor
824 * the same cgroup because a task belongs
825 * to only one perf cgroup at a time
827 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
828 perf_detach_cgroup(event
);
837 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
839 struct perf_cgroup_info
*t
;
840 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
841 event
->shadow_ctx_time
= now
- t
->timestamp
;
845 perf_cgroup_defer_enabled(struct perf_event
*event
)
848 * when the current task's perf cgroup does not match
849 * the event's, we need to remember to call the
850 * perf_mark_enable() function the first time a task with
851 * a matching perf cgroup is scheduled in.
853 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
854 event
->cgrp_defer_enabled
= 1;
858 perf_cgroup_mark_enabled(struct perf_event
*event
,
859 struct perf_event_context
*ctx
)
861 struct perf_event
*sub
;
862 u64 tstamp
= perf_event_time(event
);
864 if (!event
->cgrp_defer_enabled
)
867 event
->cgrp_defer_enabled
= 0;
869 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
870 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
871 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
872 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
873 sub
->cgrp_defer_enabled
= 0;
879 * Update cpuctx->cgrp so that it is set when first cgroup event is added and
880 * cleared when last cgroup event is removed.
883 list_update_cgroup_event(struct perf_event
*event
,
884 struct perf_event_context
*ctx
, bool add
)
886 struct perf_cpu_context
*cpuctx
;
887 struct list_head
*cpuctx_entry
;
889 if (!is_cgroup_event(event
))
892 if (add
&& ctx
->nr_cgroups
++)
894 else if (!add
&& --ctx
->nr_cgroups
)
897 * Because cgroup events are always per-cpu events,
898 * this will always be called from the right CPU.
900 cpuctx
= __get_cpu_context(ctx
);
901 cpuctx_entry
= &cpuctx
->cgrp_cpuctx_entry
;
902 /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/
904 list_add(cpuctx_entry
, this_cpu_ptr(&cgrp_cpuctx_list
));
905 if (perf_cgroup_from_task(current
, ctx
) == event
->cgrp
)
906 cpuctx
->cgrp
= event
->cgrp
;
908 list_del(cpuctx_entry
);
913 #else /* !CONFIG_CGROUP_PERF */
916 perf_cgroup_match(struct perf_event
*event
)
921 static inline void perf_detach_cgroup(struct perf_event
*event
)
924 static inline int is_cgroup_event(struct perf_event
*event
)
929 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
933 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
937 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
938 struct task_struct
*next
)
942 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
943 struct task_struct
*task
)
947 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
948 struct perf_event_attr
*attr
,
949 struct perf_event
*group_leader
)
955 perf_cgroup_set_timestamp(struct task_struct
*task
,
956 struct perf_event_context
*ctx
)
961 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
966 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
970 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
976 perf_cgroup_defer_enabled(struct perf_event
*event
)
981 perf_cgroup_mark_enabled(struct perf_event
*event
,
982 struct perf_event_context
*ctx
)
987 list_update_cgroup_event(struct perf_event
*event
,
988 struct perf_event_context
*ctx
, bool add
)
995 * set default to be dependent on timer tick just
998 #define PERF_CPU_HRTIMER (1000 / HZ)
1000 * function must be called with interrupts disabled
1002 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
1004 struct perf_cpu_context
*cpuctx
;
1007 WARN_ON(!irqs_disabled());
1009 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
1010 rotations
= perf_rotate_context(cpuctx
);
1012 raw_spin_lock(&cpuctx
->hrtimer_lock
);
1014 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
1016 cpuctx
->hrtimer_active
= 0;
1017 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
1019 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
1022 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
1024 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1025 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1028 /* no multiplexing needed for SW PMU */
1029 if (pmu
->task_ctx_nr
== perf_sw_context
)
1033 * check default is sane, if not set then force to
1034 * default interval (1/tick)
1036 interval
= pmu
->hrtimer_interval_ms
;
1038 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
1040 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
1042 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
1043 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
1044 timer
->function
= perf_mux_hrtimer_handler
;
1047 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
1049 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
1050 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
1051 unsigned long flags
;
1053 /* not for SW PMU */
1054 if (pmu
->task_ctx_nr
== perf_sw_context
)
1057 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
1058 if (!cpuctx
->hrtimer_active
) {
1059 cpuctx
->hrtimer_active
= 1;
1060 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
1061 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
1063 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
1068 void perf_pmu_disable(struct pmu
*pmu
)
1070 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1072 pmu
->pmu_disable(pmu
);
1075 void perf_pmu_enable(struct pmu
*pmu
)
1077 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
1079 pmu
->pmu_enable(pmu
);
1082 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
1085 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
1086 * perf_event_task_tick() are fully serialized because they're strictly cpu
1087 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
1088 * disabled, while perf_event_task_tick is called from IRQ context.
1090 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
1092 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
1094 WARN_ON(!irqs_disabled());
1096 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
1098 list_add(&ctx
->active_ctx_list
, head
);
1101 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
1103 WARN_ON(!irqs_disabled());
1105 WARN_ON(list_empty(&ctx
->active_ctx_list
));
1107 list_del_init(&ctx
->active_ctx_list
);
1110 static void get_ctx(struct perf_event_context
*ctx
)
1112 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
1115 static void free_ctx(struct rcu_head
*head
)
1117 struct perf_event_context
*ctx
;
1119 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
1120 kfree(ctx
->task_ctx_data
);
1124 static void put_ctx(struct perf_event_context
*ctx
)
1126 if (atomic_dec_and_test(&ctx
->refcount
)) {
1127 if (ctx
->parent_ctx
)
1128 put_ctx(ctx
->parent_ctx
);
1129 if (ctx
->task
&& ctx
->task
!= TASK_TOMBSTONE
)
1130 put_task_struct(ctx
->task
);
1131 call_rcu(&ctx
->rcu_head
, free_ctx
);
1136 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
1137 * perf_pmu_migrate_context() we need some magic.
1139 * Those places that change perf_event::ctx will hold both
1140 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
1142 * Lock ordering is by mutex address. There are two other sites where
1143 * perf_event_context::mutex nests and those are:
1145 * - perf_event_exit_task_context() [ child , 0 ]
1146 * perf_event_exit_event()
1147 * put_event() [ parent, 1 ]
1149 * - perf_event_init_context() [ parent, 0 ]
1150 * inherit_task_group()
1153 * perf_event_alloc()
1155 * perf_try_init_event() [ child , 1 ]
1157 * While it appears there is an obvious deadlock here -- the parent and child
1158 * nesting levels are inverted between the two. This is in fact safe because
1159 * life-time rules separate them. That is an exiting task cannot fork, and a
1160 * spawning task cannot (yet) exit.
1162 * But remember that that these are parent<->child context relations, and
1163 * migration does not affect children, therefore these two orderings should not
1166 * The change in perf_event::ctx does not affect children (as claimed above)
1167 * because the sys_perf_event_open() case will install a new event and break
1168 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
1169 * concerned with cpuctx and that doesn't have children.
1171 * The places that change perf_event::ctx will issue:
1173 * perf_remove_from_context();
1174 * synchronize_rcu();
1175 * perf_install_in_context();
1177 * to affect the change. The remove_from_context() + synchronize_rcu() should
1178 * quiesce the event, after which we can install it in the new location. This
1179 * means that only external vectors (perf_fops, prctl) can perturb the event
1180 * while in transit. Therefore all such accessors should also acquire
1181 * perf_event_context::mutex to serialize against this.
1183 * However; because event->ctx can change while we're waiting to acquire
1184 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
1189 * task_struct::perf_event_mutex
1190 * perf_event_context::mutex
1191 * perf_event::child_mutex;
1192 * perf_event_context::lock
1193 * perf_event::mmap_mutex
1196 static struct perf_event_context
*
1197 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
1199 struct perf_event_context
*ctx
;
1203 ctx
= ACCESS_ONCE(event
->ctx
);
1204 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1210 mutex_lock_nested(&ctx
->mutex
, nesting
);
1211 if (event
->ctx
!= ctx
) {
1212 mutex_unlock(&ctx
->mutex
);
1220 static inline struct perf_event_context
*
1221 perf_event_ctx_lock(struct perf_event
*event
)
1223 return perf_event_ctx_lock_nested(event
, 0);
1226 static void perf_event_ctx_unlock(struct perf_event
*event
,
1227 struct perf_event_context
*ctx
)
1229 mutex_unlock(&ctx
->mutex
);
1234 * This must be done under the ctx->lock, such as to serialize against
1235 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1236 * calling scheduler related locks and ctx->lock nests inside those.
1238 static __must_check
struct perf_event_context
*
1239 unclone_ctx(struct perf_event_context
*ctx
)
1241 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1243 lockdep_assert_held(&ctx
->lock
);
1246 ctx
->parent_ctx
= NULL
;
1252 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1255 * only top level events have the pid namespace they were created in
1258 event
= event
->parent
;
1260 return task_tgid_nr_ns(p
, event
->ns
);
1263 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1266 * only top level events have the pid namespace they were created in
1269 event
= event
->parent
;
1271 return task_pid_nr_ns(p
, event
->ns
);
1275 * If we inherit events we want to return the parent event id
1278 static u64
primary_event_id(struct perf_event
*event
)
1283 id
= event
->parent
->id
;
1289 * Get the perf_event_context for a task and lock it.
1291 * This has to cope with with the fact that until it is locked,
1292 * the context could get moved to another task.
1294 static struct perf_event_context
*
1295 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1297 struct perf_event_context
*ctx
;
1301 * One of the few rules of preemptible RCU is that one cannot do
1302 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1303 * part of the read side critical section was irqs-enabled -- see
1304 * rcu_read_unlock_special().
1306 * Since ctx->lock nests under rq->lock we must ensure the entire read
1307 * side critical section has interrupts disabled.
1309 local_irq_save(*flags
);
1311 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1314 * If this context is a clone of another, it might
1315 * get swapped for another underneath us by
1316 * perf_event_task_sched_out, though the
1317 * rcu_read_lock() protects us from any context
1318 * getting freed. Lock the context and check if it
1319 * got swapped before we could get the lock, and retry
1320 * if so. If we locked the right context, then it
1321 * can't get swapped on us any more.
1323 raw_spin_lock(&ctx
->lock
);
1324 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1325 raw_spin_unlock(&ctx
->lock
);
1327 local_irq_restore(*flags
);
1331 if (ctx
->task
== TASK_TOMBSTONE
||
1332 !atomic_inc_not_zero(&ctx
->refcount
)) {
1333 raw_spin_unlock(&ctx
->lock
);
1336 WARN_ON_ONCE(ctx
->task
!= task
);
1341 local_irq_restore(*flags
);
1346 * Get the context for a task and increment its pin_count so it
1347 * can't get swapped to another task. This also increments its
1348 * reference count so that the context can't get freed.
1350 static struct perf_event_context
*
1351 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1353 struct perf_event_context
*ctx
;
1354 unsigned long flags
;
1356 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1359 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1364 static void perf_unpin_context(struct perf_event_context
*ctx
)
1366 unsigned long flags
;
1368 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1370 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1374 * Update the record of the current time in a context.
1376 static void update_context_time(struct perf_event_context
*ctx
)
1378 u64 now
= perf_clock();
1380 ctx
->time
+= now
- ctx
->timestamp
;
1381 ctx
->timestamp
= now
;
1384 static u64
perf_event_time(struct perf_event
*event
)
1386 struct perf_event_context
*ctx
= event
->ctx
;
1388 if (is_cgroup_event(event
))
1389 return perf_cgroup_event_time(event
);
1391 return ctx
? ctx
->time
: 0;
1395 * Update the total_time_enabled and total_time_running fields for a event.
1397 static void update_event_times(struct perf_event
*event
)
1399 struct perf_event_context
*ctx
= event
->ctx
;
1402 lockdep_assert_held(&ctx
->lock
);
1404 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1405 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1409 * in cgroup mode, time_enabled represents
1410 * the time the event was enabled AND active
1411 * tasks were in the monitored cgroup. This is
1412 * independent of the activity of the context as
1413 * there may be a mix of cgroup and non-cgroup events.
1415 * That is why we treat cgroup events differently
1418 if (is_cgroup_event(event
))
1419 run_end
= perf_cgroup_event_time(event
);
1420 else if (ctx
->is_active
)
1421 run_end
= ctx
->time
;
1423 run_end
= event
->tstamp_stopped
;
1425 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1427 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1428 run_end
= event
->tstamp_stopped
;
1430 run_end
= perf_event_time(event
);
1432 event
->total_time_running
= run_end
- event
->tstamp_running
;
1437 * Update total_time_enabled and total_time_running for all events in a group.
1439 static void update_group_times(struct perf_event
*leader
)
1441 struct perf_event
*event
;
1443 update_event_times(leader
);
1444 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1445 update_event_times(event
);
1448 static enum event_type_t
get_event_type(struct perf_event
*event
)
1450 struct perf_event_context
*ctx
= event
->ctx
;
1451 enum event_type_t event_type
;
1453 lockdep_assert_held(&ctx
->lock
);
1456 * It's 'group type', really, because if our group leader is
1457 * pinned, so are we.
1459 if (event
->group_leader
!= event
)
1460 event
= event
->group_leader
;
1462 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1464 event_type
|= EVENT_CPU
;
1469 static struct list_head
*
1470 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1472 if (event
->attr
.pinned
)
1473 return &ctx
->pinned_groups
;
1475 return &ctx
->flexible_groups
;
1479 * Add a event from the lists for its context.
1480 * Must be called with ctx->mutex and ctx->lock held.
1483 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1485 lockdep_assert_held(&ctx
->lock
);
1487 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1488 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1491 * If we're a stand alone event or group leader, we go to the context
1492 * list, group events are kept attached to the group so that
1493 * perf_group_detach can, at all times, locate all siblings.
1495 if (event
->group_leader
== event
) {
1496 struct list_head
*list
;
1498 event
->group_caps
= event
->event_caps
;
1500 list
= ctx_group_list(event
, ctx
);
1501 list_add_tail(&event
->group_entry
, list
);
1504 list_update_cgroup_event(event
, ctx
, true);
1506 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1508 if (event
->attr
.inherit_stat
)
1515 * Initialize event state based on the perf_event_attr::disabled.
1517 static inline void perf_event__state_init(struct perf_event
*event
)
1519 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1520 PERF_EVENT_STATE_INACTIVE
;
1523 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1525 int entry
= sizeof(u64
); /* value */
1529 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1530 size
+= sizeof(u64
);
1532 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1533 size
+= sizeof(u64
);
1535 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1536 entry
+= sizeof(u64
);
1538 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1540 size
+= sizeof(u64
);
1544 event
->read_size
= size
;
1547 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1549 struct perf_sample_data
*data
;
1552 if (sample_type
& PERF_SAMPLE_IP
)
1553 size
+= sizeof(data
->ip
);
1555 if (sample_type
& PERF_SAMPLE_ADDR
)
1556 size
+= sizeof(data
->addr
);
1558 if (sample_type
& PERF_SAMPLE_PERIOD
)
1559 size
+= sizeof(data
->period
);
1561 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1562 size
+= sizeof(data
->weight
);
1564 if (sample_type
& PERF_SAMPLE_READ
)
1565 size
+= event
->read_size
;
1567 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1568 size
+= sizeof(data
->data_src
.val
);
1570 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1571 size
+= sizeof(data
->txn
);
1573 event
->header_size
= size
;
1577 * Called at perf_event creation and when events are attached/detached from a
1580 static void perf_event__header_size(struct perf_event
*event
)
1582 __perf_event_read_size(event
,
1583 event
->group_leader
->nr_siblings
);
1584 __perf_event_header_size(event
, event
->attr
.sample_type
);
1587 static void perf_event__id_header_size(struct perf_event
*event
)
1589 struct perf_sample_data
*data
;
1590 u64 sample_type
= event
->attr
.sample_type
;
1593 if (sample_type
& PERF_SAMPLE_TID
)
1594 size
+= sizeof(data
->tid_entry
);
1596 if (sample_type
& PERF_SAMPLE_TIME
)
1597 size
+= sizeof(data
->time
);
1599 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1600 size
+= sizeof(data
->id
);
1602 if (sample_type
& PERF_SAMPLE_ID
)
1603 size
+= sizeof(data
->id
);
1605 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1606 size
+= sizeof(data
->stream_id
);
1608 if (sample_type
& PERF_SAMPLE_CPU
)
1609 size
+= sizeof(data
->cpu_entry
);
1611 event
->id_header_size
= size
;
1614 static bool perf_event_validate_size(struct perf_event
*event
)
1617 * The values computed here will be over-written when we actually
1620 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1621 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1622 perf_event__id_header_size(event
);
1625 * Sum the lot; should not exceed the 64k limit we have on records.
1626 * Conservative limit to allow for callchains and other variable fields.
1628 if (event
->read_size
+ event
->header_size
+
1629 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1635 static void perf_group_attach(struct perf_event
*event
)
1637 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1639 lockdep_assert_held(&event
->ctx
->lock
);
1642 * We can have double attach due to group movement in perf_event_open.
1644 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1647 event
->attach_state
|= PERF_ATTACH_GROUP
;
1649 if (group_leader
== event
)
1652 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1654 group_leader
->group_caps
&= event
->event_caps
;
1656 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1657 group_leader
->nr_siblings
++;
1659 perf_event__header_size(group_leader
);
1661 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1662 perf_event__header_size(pos
);
1666 * Remove a event from the lists for its context.
1667 * Must be called with ctx->mutex and ctx->lock held.
1670 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1672 WARN_ON_ONCE(event
->ctx
!= ctx
);
1673 lockdep_assert_held(&ctx
->lock
);
1676 * We can have double detach due to exit/hot-unplug + close.
1678 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1681 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1683 list_update_cgroup_event(event
, ctx
, false);
1686 if (event
->attr
.inherit_stat
)
1689 list_del_rcu(&event
->event_entry
);
1691 if (event
->group_leader
== event
)
1692 list_del_init(&event
->group_entry
);
1694 update_group_times(event
);
1697 * If event was in error state, then keep it
1698 * that way, otherwise bogus counts will be
1699 * returned on read(). The only way to get out
1700 * of error state is by explicit re-enabling
1703 if (event
->state
> PERF_EVENT_STATE_OFF
)
1704 event
->state
= PERF_EVENT_STATE_OFF
;
1709 static void perf_group_detach(struct perf_event
*event
)
1711 struct perf_event
*sibling
, *tmp
;
1712 struct list_head
*list
= NULL
;
1714 lockdep_assert_held(&event
->ctx
->lock
);
1717 * We can have double detach due to exit/hot-unplug + close.
1719 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1722 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1725 * If this is a sibling, remove it from its group.
1727 if (event
->group_leader
!= event
) {
1728 list_del_init(&event
->group_entry
);
1729 event
->group_leader
->nr_siblings
--;
1733 if (!list_empty(&event
->group_entry
))
1734 list
= &event
->group_entry
;
1737 * If this was a group event with sibling events then
1738 * upgrade the siblings to singleton events by adding them
1739 * to whatever list we are on.
1741 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1743 list_move_tail(&sibling
->group_entry
, list
);
1744 sibling
->group_leader
= sibling
;
1746 /* Inherit group flags from the previous leader */
1747 sibling
->group_caps
= event
->group_caps
;
1749 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1753 perf_event__header_size(event
->group_leader
);
1755 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1756 perf_event__header_size(tmp
);
1759 static bool is_orphaned_event(struct perf_event
*event
)
1761 return event
->state
== PERF_EVENT_STATE_DEAD
;
1764 static inline int __pmu_filter_match(struct perf_event
*event
)
1766 struct pmu
*pmu
= event
->pmu
;
1767 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1771 * Check whether we should attempt to schedule an event group based on
1772 * PMU-specific filtering. An event group can consist of HW and SW events,
1773 * potentially with a SW leader, so we must check all the filters, to
1774 * determine whether a group is schedulable:
1776 static inline int pmu_filter_match(struct perf_event
*event
)
1778 struct perf_event
*child
;
1780 if (!__pmu_filter_match(event
))
1783 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1784 if (!__pmu_filter_match(child
))
1792 event_filter_match(struct perf_event
*event
)
1794 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1795 perf_cgroup_match(event
) && pmu_filter_match(event
);
1799 event_sched_out(struct perf_event
*event
,
1800 struct perf_cpu_context
*cpuctx
,
1801 struct perf_event_context
*ctx
)
1803 u64 tstamp
= perf_event_time(event
);
1806 WARN_ON_ONCE(event
->ctx
!= ctx
);
1807 lockdep_assert_held(&ctx
->lock
);
1810 * An event which could not be activated because of
1811 * filter mismatch still needs to have its timings
1812 * maintained, otherwise bogus information is return
1813 * via read() for time_enabled, time_running:
1815 if (event
->state
== PERF_EVENT_STATE_INACTIVE
&&
1816 !event_filter_match(event
)) {
1817 delta
= tstamp
- event
->tstamp_stopped
;
1818 event
->tstamp_running
+= delta
;
1819 event
->tstamp_stopped
= tstamp
;
1822 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1825 perf_pmu_disable(event
->pmu
);
1827 event
->tstamp_stopped
= tstamp
;
1828 event
->pmu
->del(event
, 0);
1830 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1831 if (event
->pending_disable
) {
1832 event
->pending_disable
= 0;
1833 event
->state
= PERF_EVENT_STATE_OFF
;
1836 if (!is_software_event(event
))
1837 cpuctx
->active_oncpu
--;
1838 if (!--ctx
->nr_active
)
1839 perf_event_ctx_deactivate(ctx
);
1840 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1842 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1843 cpuctx
->exclusive
= 0;
1845 perf_pmu_enable(event
->pmu
);
1849 group_sched_out(struct perf_event
*group_event
,
1850 struct perf_cpu_context
*cpuctx
,
1851 struct perf_event_context
*ctx
)
1853 struct perf_event
*event
;
1854 int state
= group_event
->state
;
1856 perf_pmu_disable(ctx
->pmu
);
1858 event_sched_out(group_event
, cpuctx
, ctx
);
1861 * Schedule out siblings (if any):
1863 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1864 event_sched_out(event
, cpuctx
, ctx
);
1866 perf_pmu_enable(ctx
->pmu
);
1868 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1869 cpuctx
->exclusive
= 0;
1872 #define DETACH_GROUP 0x01UL
1875 * Cross CPU call to remove a performance event
1877 * We disable the event on the hardware level first. After that we
1878 * remove it from the context list.
1881 __perf_remove_from_context(struct perf_event
*event
,
1882 struct perf_cpu_context
*cpuctx
,
1883 struct perf_event_context
*ctx
,
1886 unsigned long flags
= (unsigned long)info
;
1888 event_sched_out(event
, cpuctx
, ctx
);
1889 if (flags
& DETACH_GROUP
)
1890 perf_group_detach(event
);
1891 list_del_event(event
, ctx
);
1893 if (!ctx
->nr_events
&& ctx
->is_active
) {
1896 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1897 cpuctx
->task_ctx
= NULL
;
1903 * Remove the event from a task's (or a CPU's) list of events.
1905 * If event->ctx is a cloned context, callers must make sure that
1906 * every task struct that event->ctx->task could possibly point to
1907 * remains valid. This is OK when called from perf_release since
1908 * that only calls us on the top-level context, which can't be a clone.
1909 * When called from perf_event_exit_task, it's OK because the
1910 * context has been detached from its task.
1912 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1914 struct perf_event_context
*ctx
= event
->ctx
;
1916 lockdep_assert_held(&ctx
->mutex
);
1918 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1921 * The above event_function_call() can NO-OP when it hits
1922 * TASK_TOMBSTONE. In that case we must already have been detached
1923 * from the context (by perf_event_exit_event()) but the grouping
1924 * might still be in-tact.
1926 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1927 if ((flags
& DETACH_GROUP
) &&
1928 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
1930 * Since in that case we cannot possibly be scheduled, simply
1933 raw_spin_lock_irq(&ctx
->lock
);
1934 perf_group_detach(event
);
1935 raw_spin_unlock_irq(&ctx
->lock
);
1940 * Cross CPU call to disable a performance event
1942 static void __perf_event_disable(struct perf_event
*event
,
1943 struct perf_cpu_context
*cpuctx
,
1944 struct perf_event_context
*ctx
,
1947 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1950 update_context_time(ctx
);
1951 update_cgrp_time_from_event(event
);
1952 update_group_times(event
);
1953 if (event
== event
->group_leader
)
1954 group_sched_out(event
, cpuctx
, ctx
);
1956 event_sched_out(event
, cpuctx
, ctx
);
1957 event
->state
= PERF_EVENT_STATE_OFF
;
1963 * If event->ctx is a cloned context, callers must make sure that
1964 * every task struct that event->ctx->task could possibly point to
1965 * remains valid. This condition is satisifed when called through
1966 * perf_event_for_each_child or perf_event_for_each because they
1967 * hold the top-level event's child_mutex, so any descendant that
1968 * goes to exit will block in perf_event_exit_event().
1970 * When called from perf_pending_event it's OK because event->ctx
1971 * is the current context on this CPU and preemption is disabled,
1972 * hence we can't get into perf_event_task_sched_out for this context.
1974 static void _perf_event_disable(struct perf_event
*event
)
1976 struct perf_event_context
*ctx
= event
->ctx
;
1978 raw_spin_lock_irq(&ctx
->lock
);
1979 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1980 raw_spin_unlock_irq(&ctx
->lock
);
1983 raw_spin_unlock_irq(&ctx
->lock
);
1985 event_function_call(event
, __perf_event_disable
, NULL
);
1988 void perf_event_disable_local(struct perf_event
*event
)
1990 event_function_local(event
, __perf_event_disable
, NULL
);
1994 * Strictly speaking kernel users cannot create groups and therefore this
1995 * interface does not need the perf_event_ctx_lock() magic.
1997 void perf_event_disable(struct perf_event
*event
)
1999 struct perf_event_context
*ctx
;
2001 ctx
= perf_event_ctx_lock(event
);
2002 _perf_event_disable(event
);
2003 perf_event_ctx_unlock(event
, ctx
);
2005 EXPORT_SYMBOL_GPL(perf_event_disable
);
2007 void perf_event_disable_inatomic(struct perf_event
*event
)
2009 event
->pending_disable
= 1;
2010 irq_work_queue(&event
->pending
);
2013 static void perf_set_shadow_time(struct perf_event
*event
,
2014 struct perf_event_context
*ctx
,
2018 * use the correct time source for the time snapshot
2020 * We could get by without this by leveraging the
2021 * fact that to get to this function, the caller
2022 * has most likely already called update_context_time()
2023 * and update_cgrp_time_xx() and thus both timestamp
2024 * are identical (or very close). Given that tstamp is,
2025 * already adjusted for cgroup, we could say that:
2026 * tstamp - ctx->timestamp
2028 * tstamp - cgrp->timestamp.
2030 * Then, in perf_output_read(), the calculation would
2031 * work with no changes because:
2032 * - event is guaranteed scheduled in
2033 * - no scheduled out in between
2034 * - thus the timestamp would be the same
2036 * But this is a bit hairy.
2038 * So instead, we have an explicit cgroup call to remain
2039 * within the time time source all along. We believe it
2040 * is cleaner and simpler to understand.
2042 if (is_cgroup_event(event
))
2043 perf_cgroup_set_shadow_time(event
, tstamp
);
2045 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
2048 #define MAX_INTERRUPTS (~0ULL)
2050 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2051 static void perf_log_itrace_start(struct perf_event
*event
);
2054 event_sched_in(struct perf_event
*event
,
2055 struct perf_cpu_context
*cpuctx
,
2056 struct perf_event_context
*ctx
)
2058 u64 tstamp
= perf_event_time(event
);
2061 lockdep_assert_held(&ctx
->lock
);
2063 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2066 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2068 * Order event::oncpu write to happen before the ACTIVE state
2072 WRITE_ONCE(event
->state
, PERF_EVENT_STATE_ACTIVE
);
2075 * Unthrottle events, since we scheduled we might have missed several
2076 * ticks already, also for a heavily scheduling task there is little
2077 * guarantee it'll get a tick in a timely manner.
2079 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2080 perf_log_throttle(event
, 1);
2081 event
->hw
.interrupts
= 0;
2085 * The new state must be visible before we turn it on in the hardware:
2089 perf_pmu_disable(event
->pmu
);
2091 perf_set_shadow_time(event
, ctx
, tstamp
);
2093 perf_log_itrace_start(event
);
2095 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2096 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2102 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
2104 if (!is_software_event(event
))
2105 cpuctx
->active_oncpu
++;
2106 if (!ctx
->nr_active
++)
2107 perf_event_ctx_activate(ctx
);
2108 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2111 if (event
->attr
.exclusive
)
2112 cpuctx
->exclusive
= 1;
2115 perf_pmu_enable(event
->pmu
);
2121 group_sched_in(struct perf_event
*group_event
,
2122 struct perf_cpu_context
*cpuctx
,
2123 struct perf_event_context
*ctx
)
2125 struct perf_event
*event
, *partial_group
= NULL
;
2126 struct pmu
*pmu
= ctx
->pmu
;
2127 u64 now
= ctx
->time
;
2128 bool simulate
= false;
2130 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2133 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2135 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2136 pmu
->cancel_txn(pmu
);
2137 perf_mux_hrtimer_restart(cpuctx
);
2142 * Schedule in siblings as one group (if any):
2144 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2145 if (event_sched_in(event
, cpuctx
, ctx
)) {
2146 partial_group
= event
;
2151 if (!pmu
->commit_txn(pmu
))
2156 * Groups can be scheduled in as one unit only, so undo any
2157 * partial group before returning:
2158 * The events up to the failed event are scheduled out normally,
2159 * tstamp_stopped will be updated.
2161 * The failed events and the remaining siblings need to have
2162 * their timings updated as if they had gone thru event_sched_in()
2163 * and event_sched_out(). This is required to get consistent timings
2164 * across the group. This also takes care of the case where the group
2165 * could never be scheduled by ensuring tstamp_stopped is set to mark
2166 * the time the event was actually stopped, such that time delta
2167 * calculation in update_event_times() is correct.
2169 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2170 if (event
== partial_group
)
2174 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2175 event
->tstamp_stopped
= now
;
2177 event_sched_out(event
, cpuctx
, ctx
);
2180 event_sched_out(group_event
, cpuctx
, ctx
);
2182 pmu
->cancel_txn(pmu
);
2184 perf_mux_hrtimer_restart(cpuctx
);
2190 * Work out whether we can put this event group on the CPU now.
2192 static int group_can_go_on(struct perf_event
*event
,
2193 struct perf_cpu_context
*cpuctx
,
2197 * Groups consisting entirely of software events can always go on.
2199 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2202 * If an exclusive group is already on, no other hardware
2205 if (cpuctx
->exclusive
)
2208 * If this group is exclusive and there are already
2209 * events on the CPU, it can't go on.
2211 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2214 * Otherwise, try to add it if all previous groups were able
2221 * Complement to update_event_times(). This computes the tstamp_* values to
2222 * continue 'enabled' state from @now, and effectively discards the time
2223 * between the prior tstamp_stopped and now (as we were in the OFF state, or
2224 * just switched (context) time base).
2226 * This further assumes '@event->state == INACTIVE' (we just came from OFF) and
2227 * cannot have been scheduled in yet. And going into INACTIVE state means
2228 * '@event->tstamp_stopped = @now'.
2230 * Thus given the rules of update_event_times():
2232 * total_time_enabled = tstamp_stopped - tstamp_enabled
2233 * total_time_running = tstamp_stopped - tstamp_running
2235 * We can insert 'tstamp_stopped == now' and reverse them to compute new
2238 static void __perf_event_enable_time(struct perf_event
*event
, u64 now
)
2240 WARN_ON_ONCE(event
->state
!= PERF_EVENT_STATE_INACTIVE
);
2242 event
->tstamp_stopped
= now
;
2243 event
->tstamp_enabled
= now
- event
->total_time_enabled
;
2244 event
->tstamp_running
= now
- event
->total_time_running
;
2247 static void add_event_to_ctx(struct perf_event
*event
,
2248 struct perf_event_context
*ctx
)
2250 u64 tstamp
= perf_event_time(event
);
2252 list_add_event(event
, ctx
);
2253 perf_group_attach(event
);
2255 * We can be called with event->state == STATE_OFF when we create with
2256 * .disabled = 1. In that case the IOC_ENABLE will call this function.
2258 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
2259 __perf_event_enable_time(event
, tstamp
);
2262 static void ctx_sched_out(struct perf_event_context
*ctx
,
2263 struct perf_cpu_context
*cpuctx
,
2264 enum event_type_t event_type
);
2266 ctx_sched_in(struct perf_event_context
*ctx
,
2267 struct perf_cpu_context
*cpuctx
,
2268 enum event_type_t event_type
,
2269 struct task_struct
*task
);
2271 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2272 struct perf_event_context
*ctx
,
2273 enum event_type_t event_type
)
2275 if (!cpuctx
->task_ctx
)
2278 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2281 ctx_sched_out(ctx
, cpuctx
, event_type
);
2284 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2285 struct perf_event_context
*ctx
,
2286 struct task_struct
*task
)
2288 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2290 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2291 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2293 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2297 * We want to maintain the following priority of scheduling:
2298 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2299 * - task pinned (EVENT_PINNED)
2300 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2301 * - task flexible (EVENT_FLEXIBLE).
2303 * In order to avoid unscheduling and scheduling back in everything every
2304 * time an event is added, only do it for the groups of equal priority and
2307 * This can be called after a batch operation on task events, in which case
2308 * event_type is a bit mask of the types of events involved. For CPU events,
2309 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2311 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2312 struct perf_event_context
*task_ctx
,
2313 enum event_type_t event_type
)
2315 enum event_type_t ctx_event_type
= event_type
& EVENT_ALL
;
2316 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2319 * If pinned groups are involved, flexible groups also need to be
2322 if (event_type
& EVENT_PINNED
)
2323 event_type
|= EVENT_FLEXIBLE
;
2325 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2327 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2330 * Decide which cpu ctx groups to schedule out based on the types
2331 * of events that caused rescheduling:
2332 * - EVENT_CPU: schedule out corresponding groups;
2333 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2334 * - otherwise, do nothing more.
2337 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2338 else if (ctx_event_type
& EVENT_PINNED
)
2339 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2341 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2342 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2346 * Cross CPU call to install and enable a performance event
2348 * Very similar to remote_function() + event_function() but cannot assume that
2349 * things like ctx->is_active and cpuctx->task_ctx are set.
2351 static int __perf_install_in_context(void *info
)
2353 struct perf_event
*event
= info
;
2354 struct perf_event_context
*ctx
= event
->ctx
;
2355 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2356 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2357 bool reprogram
= true;
2360 raw_spin_lock(&cpuctx
->ctx
.lock
);
2362 raw_spin_lock(&ctx
->lock
);
2365 reprogram
= (ctx
->task
== current
);
2368 * If the task is running, it must be running on this CPU,
2369 * otherwise we cannot reprogram things.
2371 * If its not running, we don't care, ctx->lock will
2372 * serialize against it becoming runnable.
2374 if (task_curr(ctx
->task
) && !reprogram
) {
2379 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2380 } else if (task_ctx
) {
2381 raw_spin_lock(&task_ctx
->lock
);
2385 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2386 add_event_to_ctx(event
, ctx
);
2387 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2389 add_event_to_ctx(event
, ctx
);
2393 perf_ctx_unlock(cpuctx
, task_ctx
);
2399 * Attach a performance event to a context.
2401 * Very similar to event_function_call, see comment there.
2404 perf_install_in_context(struct perf_event_context
*ctx
,
2405 struct perf_event
*event
,
2408 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2410 lockdep_assert_held(&ctx
->mutex
);
2412 if (event
->cpu
!= -1)
2416 * Ensures that if we can observe event->ctx, both the event and ctx
2417 * will be 'complete'. See perf_iterate_sb_cpu().
2419 smp_store_release(&event
->ctx
, ctx
);
2422 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2427 * Should not happen, we validate the ctx is still alive before calling.
2429 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2433 * Installing events is tricky because we cannot rely on ctx->is_active
2434 * to be set in case this is the nr_events 0 -> 1 transition.
2436 * Instead we use task_curr(), which tells us if the task is running.
2437 * However, since we use task_curr() outside of rq::lock, we can race
2438 * against the actual state. This means the result can be wrong.
2440 * If we get a false positive, we retry, this is harmless.
2442 * If we get a false negative, things are complicated. If we are after
2443 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2444 * value must be correct. If we're before, it doesn't matter since
2445 * perf_event_context_sched_in() will program the counter.
2447 * However, this hinges on the remote context switch having observed
2448 * our task->perf_event_ctxp[] store, such that it will in fact take
2449 * ctx::lock in perf_event_context_sched_in().
2451 * We do this by task_function_call(), if the IPI fails to hit the task
2452 * we know any future context switch of task must see the
2453 * perf_event_ctpx[] store.
2457 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2458 * task_cpu() load, such that if the IPI then does not find the task
2459 * running, a future context switch of that task must observe the
2464 if (!task_function_call(task
, __perf_install_in_context
, event
))
2467 raw_spin_lock_irq(&ctx
->lock
);
2469 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2471 * Cannot happen because we already checked above (which also
2472 * cannot happen), and we hold ctx->mutex, which serializes us
2473 * against perf_event_exit_task_context().
2475 raw_spin_unlock_irq(&ctx
->lock
);
2479 * If the task is not running, ctx->lock will avoid it becoming so,
2480 * thus we can safely install the event.
2482 if (task_curr(task
)) {
2483 raw_spin_unlock_irq(&ctx
->lock
);
2486 add_event_to_ctx(event
, ctx
);
2487 raw_spin_unlock_irq(&ctx
->lock
);
2491 * Put a event into inactive state and update time fields.
2492 * Enabling the leader of a group effectively enables all
2493 * the group members that aren't explicitly disabled, so we
2494 * have to update their ->tstamp_enabled also.
2495 * Note: this works for group members as well as group leaders
2496 * since the non-leader members' sibling_lists will be empty.
2498 static void __perf_event_mark_enabled(struct perf_event
*event
)
2500 struct perf_event
*sub
;
2501 u64 tstamp
= perf_event_time(event
);
2503 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2504 __perf_event_enable_time(event
, tstamp
);
2505 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2506 /* XXX should not be > INACTIVE if event isn't */
2507 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2508 __perf_event_enable_time(sub
, tstamp
);
2513 * Cross CPU call to enable a performance event
2515 static void __perf_event_enable(struct perf_event
*event
,
2516 struct perf_cpu_context
*cpuctx
,
2517 struct perf_event_context
*ctx
,
2520 struct perf_event
*leader
= event
->group_leader
;
2521 struct perf_event_context
*task_ctx
;
2523 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2524 event
->state
<= PERF_EVENT_STATE_ERROR
)
2528 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2530 __perf_event_mark_enabled(event
);
2532 if (!ctx
->is_active
)
2535 if (!event_filter_match(event
)) {
2536 if (is_cgroup_event(event
))
2537 perf_cgroup_defer_enabled(event
);
2538 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2543 * If the event is in a group and isn't the group leader,
2544 * then don't put it on unless the group is on.
2546 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2547 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2551 task_ctx
= cpuctx
->task_ctx
;
2553 WARN_ON_ONCE(task_ctx
!= ctx
);
2555 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2561 * If event->ctx is a cloned context, callers must make sure that
2562 * every task struct that event->ctx->task could possibly point to
2563 * remains valid. This condition is satisfied when called through
2564 * perf_event_for_each_child or perf_event_for_each as described
2565 * for perf_event_disable.
2567 static void _perf_event_enable(struct perf_event
*event
)
2569 struct perf_event_context
*ctx
= event
->ctx
;
2571 raw_spin_lock_irq(&ctx
->lock
);
2572 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2573 event
->state
< PERF_EVENT_STATE_ERROR
) {
2574 raw_spin_unlock_irq(&ctx
->lock
);
2579 * If the event is in error state, clear that first.
2581 * That way, if we see the event in error state below, we know that it
2582 * has gone back into error state, as distinct from the task having
2583 * been scheduled away before the cross-call arrived.
2585 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2586 event
->state
= PERF_EVENT_STATE_OFF
;
2587 raw_spin_unlock_irq(&ctx
->lock
);
2589 event_function_call(event
, __perf_event_enable
, NULL
);
2593 * See perf_event_disable();
2595 void perf_event_enable(struct perf_event
*event
)
2597 struct perf_event_context
*ctx
;
2599 ctx
= perf_event_ctx_lock(event
);
2600 _perf_event_enable(event
);
2601 perf_event_ctx_unlock(event
, ctx
);
2603 EXPORT_SYMBOL_GPL(perf_event_enable
);
2605 struct stop_event_data
{
2606 struct perf_event
*event
;
2607 unsigned int restart
;
2610 static int __perf_event_stop(void *info
)
2612 struct stop_event_data
*sd
= info
;
2613 struct perf_event
*event
= sd
->event
;
2615 /* if it's already INACTIVE, do nothing */
2616 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2619 /* matches smp_wmb() in event_sched_in() */
2623 * There is a window with interrupts enabled before we get here,
2624 * so we need to check again lest we try to stop another CPU's event.
2626 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2629 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2632 * May race with the actual stop (through perf_pmu_output_stop()),
2633 * but it is only used for events with AUX ring buffer, and such
2634 * events will refuse to restart because of rb::aux_mmap_count==0,
2635 * see comments in perf_aux_output_begin().
2637 * Since this is happening on a event-local CPU, no trace is lost
2641 event
->pmu
->start(event
, 0);
2646 static int perf_event_stop(struct perf_event
*event
, int restart
)
2648 struct stop_event_data sd
= {
2655 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2658 /* matches smp_wmb() in event_sched_in() */
2662 * We only want to restart ACTIVE events, so if the event goes
2663 * inactive here (event->oncpu==-1), there's nothing more to do;
2664 * fall through with ret==-ENXIO.
2666 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2667 __perf_event_stop
, &sd
);
2668 } while (ret
== -EAGAIN
);
2674 * In order to contain the amount of racy and tricky in the address filter
2675 * configuration management, it is a two part process:
2677 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2678 * we update the addresses of corresponding vmas in
2679 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2680 * (p2) when an event is scheduled in (pmu::add), it calls
2681 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2682 * if the generation has changed since the previous call.
2684 * If (p1) happens while the event is active, we restart it to force (p2).
2686 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2687 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2689 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2690 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2692 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2695 void perf_event_addr_filters_sync(struct perf_event
*event
)
2697 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2699 if (!has_addr_filter(event
))
2702 raw_spin_lock(&ifh
->lock
);
2703 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2704 event
->pmu
->addr_filters_sync(event
);
2705 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2707 raw_spin_unlock(&ifh
->lock
);
2709 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2711 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2714 * not supported on inherited events
2716 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2719 atomic_add(refresh
, &event
->event_limit
);
2720 _perf_event_enable(event
);
2726 * See perf_event_disable()
2728 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2730 struct perf_event_context
*ctx
;
2733 ctx
= perf_event_ctx_lock(event
);
2734 ret
= _perf_event_refresh(event
, refresh
);
2735 perf_event_ctx_unlock(event
, ctx
);
2739 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2741 static void ctx_sched_out(struct perf_event_context
*ctx
,
2742 struct perf_cpu_context
*cpuctx
,
2743 enum event_type_t event_type
)
2745 int is_active
= ctx
->is_active
;
2746 struct perf_event
*event
;
2748 lockdep_assert_held(&ctx
->lock
);
2750 if (likely(!ctx
->nr_events
)) {
2752 * See __perf_remove_from_context().
2754 WARN_ON_ONCE(ctx
->is_active
);
2756 WARN_ON_ONCE(cpuctx
->task_ctx
);
2760 ctx
->is_active
&= ~event_type
;
2761 if (!(ctx
->is_active
& EVENT_ALL
))
2765 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2766 if (!ctx
->is_active
)
2767 cpuctx
->task_ctx
= NULL
;
2771 * Always update time if it was set; not only when it changes.
2772 * Otherwise we can 'forget' to update time for any but the last
2773 * context we sched out. For example:
2775 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2776 * ctx_sched_out(.event_type = EVENT_PINNED)
2778 * would only update time for the pinned events.
2780 if (is_active
& EVENT_TIME
) {
2781 /* update (and stop) ctx time */
2782 update_context_time(ctx
);
2783 update_cgrp_time_from_cpuctx(cpuctx
);
2786 is_active
^= ctx
->is_active
; /* changed bits */
2788 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2791 perf_pmu_disable(ctx
->pmu
);
2792 if (is_active
& EVENT_PINNED
) {
2793 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2794 group_sched_out(event
, cpuctx
, ctx
);
2797 if (is_active
& EVENT_FLEXIBLE
) {
2798 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2799 group_sched_out(event
, cpuctx
, ctx
);
2801 perf_pmu_enable(ctx
->pmu
);
2805 * Test whether two contexts are equivalent, i.e. whether they have both been
2806 * cloned from the same version of the same context.
2808 * Equivalence is measured using a generation number in the context that is
2809 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2810 * and list_del_event().
2812 static int context_equiv(struct perf_event_context
*ctx1
,
2813 struct perf_event_context
*ctx2
)
2815 lockdep_assert_held(&ctx1
->lock
);
2816 lockdep_assert_held(&ctx2
->lock
);
2818 /* Pinning disables the swap optimization */
2819 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2822 /* If ctx1 is the parent of ctx2 */
2823 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2826 /* If ctx2 is the parent of ctx1 */
2827 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2831 * If ctx1 and ctx2 have the same parent; we flatten the parent
2832 * hierarchy, see perf_event_init_context().
2834 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2835 ctx1
->parent_gen
== ctx2
->parent_gen
)
2842 static void __perf_event_sync_stat(struct perf_event
*event
,
2843 struct perf_event
*next_event
)
2847 if (!event
->attr
.inherit_stat
)
2851 * Update the event value, we cannot use perf_event_read()
2852 * because we're in the middle of a context switch and have IRQs
2853 * disabled, which upsets smp_call_function_single(), however
2854 * we know the event must be on the current CPU, therefore we
2855 * don't need to use it.
2857 switch (event
->state
) {
2858 case PERF_EVENT_STATE_ACTIVE
:
2859 event
->pmu
->read(event
);
2862 case PERF_EVENT_STATE_INACTIVE
:
2863 update_event_times(event
);
2871 * In order to keep per-task stats reliable we need to flip the event
2872 * values when we flip the contexts.
2874 value
= local64_read(&next_event
->count
);
2875 value
= local64_xchg(&event
->count
, value
);
2876 local64_set(&next_event
->count
, value
);
2878 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2879 swap(event
->total_time_running
, next_event
->total_time_running
);
2882 * Since we swizzled the values, update the user visible data too.
2884 perf_event_update_userpage(event
);
2885 perf_event_update_userpage(next_event
);
2888 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2889 struct perf_event_context
*next_ctx
)
2891 struct perf_event
*event
, *next_event
;
2896 update_context_time(ctx
);
2898 event
= list_first_entry(&ctx
->event_list
,
2899 struct perf_event
, event_entry
);
2901 next_event
= list_first_entry(&next_ctx
->event_list
,
2902 struct perf_event
, event_entry
);
2904 while (&event
->event_entry
!= &ctx
->event_list
&&
2905 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2907 __perf_event_sync_stat(event
, next_event
);
2909 event
= list_next_entry(event
, event_entry
);
2910 next_event
= list_next_entry(next_event
, event_entry
);
2914 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2915 struct task_struct
*next
)
2917 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2918 struct perf_event_context
*next_ctx
;
2919 struct perf_event_context
*parent
, *next_parent
;
2920 struct perf_cpu_context
*cpuctx
;
2926 cpuctx
= __get_cpu_context(ctx
);
2927 if (!cpuctx
->task_ctx
)
2931 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2935 parent
= rcu_dereference(ctx
->parent_ctx
);
2936 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2938 /* If neither context have a parent context; they cannot be clones. */
2939 if (!parent
&& !next_parent
)
2942 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2944 * Looks like the two contexts are clones, so we might be
2945 * able to optimize the context switch. We lock both
2946 * contexts and check that they are clones under the
2947 * lock (including re-checking that neither has been
2948 * uncloned in the meantime). It doesn't matter which
2949 * order we take the locks because no other cpu could
2950 * be trying to lock both of these tasks.
2952 raw_spin_lock(&ctx
->lock
);
2953 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2954 if (context_equiv(ctx
, next_ctx
)) {
2955 WRITE_ONCE(ctx
->task
, next
);
2956 WRITE_ONCE(next_ctx
->task
, task
);
2958 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2961 * RCU_INIT_POINTER here is safe because we've not
2962 * modified the ctx and the above modification of
2963 * ctx->task and ctx->task_ctx_data are immaterial
2964 * since those values are always verified under
2965 * ctx->lock which we're now holding.
2967 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2968 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2972 perf_event_sync_stat(ctx
, next_ctx
);
2974 raw_spin_unlock(&next_ctx
->lock
);
2975 raw_spin_unlock(&ctx
->lock
);
2981 raw_spin_lock(&ctx
->lock
);
2982 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
2983 raw_spin_unlock(&ctx
->lock
);
2987 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
2989 void perf_sched_cb_dec(struct pmu
*pmu
)
2991 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2993 this_cpu_dec(perf_sched_cb_usages
);
2995 if (!--cpuctx
->sched_cb_usage
)
2996 list_del(&cpuctx
->sched_cb_entry
);
3000 void perf_sched_cb_inc(struct pmu
*pmu
)
3002 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
3004 if (!cpuctx
->sched_cb_usage
++)
3005 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
3007 this_cpu_inc(perf_sched_cb_usages
);
3011 * This function provides the context switch callback to the lower code
3012 * layer. It is invoked ONLY when the context switch callback is enabled.
3014 * This callback is relevant even to per-cpu events; for example multi event
3015 * PEBS requires this to provide PID/TID information. This requires we flush
3016 * all queued PEBS records before we context switch to a new task.
3018 static void perf_pmu_sched_task(struct task_struct
*prev
,
3019 struct task_struct
*next
,
3022 struct perf_cpu_context
*cpuctx
;
3028 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
3029 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
3031 if (WARN_ON_ONCE(!pmu
->sched_task
))
3034 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3035 perf_pmu_disable(pmu
);
3037 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3039 perf_pmu_enable(pmu
);
3040 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3044 static void perf_event_switch(struct task_struct
*task
,
3045 struct task_struct
*next_prev
, bool sched_in
);
3047 #define for_each_task_context_nr(ctxn) \
3048 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3051 * Called from scheduler to remove the events of the current task,
3052 * with interrupts disabled.
3054 * We stop each event and update the event value in event->count.
3056 * This does not protect us against NMI, but disable()
3057 * sets the disabled bit in the control field of event _before_
3058 * accessing the event control register. If a NMI hits, then it will
3059 * not restart the event.
3061 void __perf_event_task_sched_out(struct task_struct
*task
,
3062 struct task_struct
*next
)
3066 if (__this_cpu_read(perf_sched_cb_usages
))
3067 perf_pmu_sched_task(task
, next
, false);
3069 if (atomic_read(&nr_switch_events
))
3070 perf_event_switch(task
, next
, false);
3072 for_each_task_context_nr(ctxn
)
3073 perf_event_context_sched_out(task
, ctxn
, next
);
3076 * if cgroup events exist on this CPU, then we need
3077 * to check if we have to switch out PMU state.
3078 * cgroup event are system-wide mode only
3080 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3081 perf_cgroup_sched_out(task
, next
);
3085 * Called with IRQs disabled
3087 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3088 enum event_type_t event_type
)
3090 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3094 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3095 struct perf_cpu_context
*cpuctx
)
3097 struct perf_event
*event
;
3099 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
3100 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3102 if (!event_filter_match(event
))
3105 /* may need to reset tstamp_enabled */
3106 if (is_cgroup_event(event
))
3107 perf_cgroup_mark_enabled(event
, ctx
);
3109 if (group_can_go_on(event
, cpuctx
, 1))
3110 group_sched_in(event
, cpuctx
, ctx
);
3113 * If this pinned group hasn't been scheduled,
3114 * put it in error state.
3116 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3117 update_group_times(event
);
3118 event
->state
= PERF_EVENT_STATE_ERROR
;
3124 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3125 struct perf_cpu_context
*cpuctx
)
3127 struct perf_event
*event
;
3130 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3131 /* Ignore events in OFF or ERROR state */
3132 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3135 * Listen to the 'cpu' scheduling filter constraint
3138 if (!event_filter_match(event
))
3141 /* may need to reset tstamp_enabled */
3142 if (is_cgroup_event(event
))
3143 perf_cgroup_mark_enabled(event
, ctx
);
3145 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3146 if (group_sched_in(event
, cpuctx
, ctx
))
3153 ctx_sched_in(struct perf_event_context
*ctx
,
3154 struct perf_cpu_context
*cpuctx
,
3155 enum event_type_t event_type
,
3156 struct task_struct
*task
)
3158 int is_active
= ctx
->is_active
;
3161 lockdep_assert_held(&ctx
->lock
);
3163 if (likely(!ctx
->nr_events
))
3166 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3169 cpuctx
->task_ctx
= ctx
;
3171 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3174 is_active
^= ctx
->is_active
; /* changed bits */
3176 if (is_active
& EVENT_TIME
) {
3177 /* start ctx time */
3179 ctx
->timestamp
= now
;
3180 perf_cgroup_set_timestamp(task
, ctx
);
3184 * First go through the list and put on any pinned groups
3185 * in order to give them the best chance of going on.
3187 if (is_active
& EVENT_PINNED
)
3188 ctx_pinned_sched_in(ctx
, cpuctx
);
3190 /* Then walk through the lower prio flexible groups */
3191 if (is_active
& EVENT_FLEXIBLE
)
3192 ctx_flexible_sched_in(ctx
, cpuctx
);
3195 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3196 enum event_type_t event_type
,
3197 struct task_struct
*task
)
3199 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3201 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3204 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3205 struct task_struct
*task
)
3207 struct perf_cpu_context
*cpuctx
;
3209 cpuctx
= __get_cpu_context(ctx
);
3210 if (cpuctx
->task_ctx
== ctx
)
3213 perf_ctx_lock(cpuctx
, ctx
);
3214 perf_pmu_disable(ctx
->pmu
);
3216 * We want to keep the following priority order:
3217 * cpu pinned (that don't need to move), task pinned,
3218 * cpu flexible, task flexible.
3220 * However, if task's ctx is not carrying any pinned
3221 * events, no need to flip the cpuctx's events around.
3223 if (!list_empty(&ctx
->pinned_groups
))
3224 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3225 perf_event_sched_in(cpuctx
, ctx
, task
);
3226 perf_pmu_enable(ctx
->pmu
);
3227 perf_ctx_unlock(cpuctx
, ctx
);
3231 * Called from scheduler to add the events of the current task
3232 * with interrupts disabled.
3234 * We restore the event value and then enable it.
3236 * This does not protect us against NMI, but enable()
3237 * sets the enabled bit in the control field of event _before_
3238 * accessing the event control register. If a NMI hits, then it will
3239 * keep the event running.
3241 void __perf_event_task_sched_in(struct task_struct
*prev
,
3242 struct task_struct
*task
)
3244 struct perf_event_context
*ctx
;
3248 * If cgroup events exist on this CPU, then we need to check if we have
3249 * to switch in PMU state; cgroup event are system-wide mode only.
3251 * Since cgroup events are CPU events, we must schedule these in before
3252 * we schedule in the task events.
3254 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3255 perf_cgroup_sched_in(prev
, task
);
3257 for_each_task_context_nr(ctxn
) {
3258 ctx
= task
->perf_event_ctxp
[ctxn
];
3262 perf_event_context_sched_in(ctx
, task
);
3265 if (atomic_read(&nr_switch_events
))
3266 perf_event_switch(task
, prev
, true);
3268 if (__this_cpu_read(perf_sched_cb_usages
))
3269 perf_pmu_sched_task(prev
, task
, true);
3272 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3274 u64 frequency
= event
->attr
.sample_freq
;
3275 u64 sec
= NSEC_PER_SEC
;
3276 u64 divisor
, dividend
;
3278 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3280 count_fls
= fls64(count
);
3281 nsec_fls
= fls64(nsec
);
3282 frequency_fls
= fls64(frequency
);
3286 * We got @count in @nsec, with a target of sample_freq HZ
3287 * the target period becomes:
3290 * period = -------------------
3291 * @nsec * sample_freq
3296 * Reduce accuracy by one bit such that @a and @b converge
3297 * to a similar magnitude.
3299 #define REDUCE_FLS(a, b) \
3301 if (a##_fls > b##_fls) { \
3311 * Reduce accuracy until either term fits in a u64, then proceed with
3312 * the other, so that finally we can do a u64/u64 division.
3314 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3315 REDUCE_FLS(nsec
, frequency
);
3316 REDUCE_FLS(sec
, count
);
3319 if (count_fls
+ sec_fls
> 64) {
3320 divisor
= nsec
* frequency
;
3322 while (count_fls
+ sec_fls
> 64) {
3323 REDUCE_FLS(count
, sec
);
3327 dividend
= count
* sec
;
3329 dividend
= count
* sec
;
3331 while (nsec_fls
+ frequency_fls
> 64) {
3332 REDUCE_FLS(nsec
, frequency
);
3336 divisor
= nsec
* frequency
;
3342 return div64_u64(dividend
, divisor
);
3345 static DEFINE_PER_CPU(int, perf_throttled_count
);
3346 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3348 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3350 struct hw_perf_event
*hwc
= &event
->hw
;
3351 s64 period
, sample_period
;
3354 period
= perf_calculate_period(event
, nsec
, count
);
3356 delta
= (s64
)(period
- hwc
->sample_period
);
3357 delta
= (delta
+ 7) / 8; /* low pass filter */
3359 sample_period
= hwc
->sample_period
+ delta
;
3364 hwc
->sample_period
= sample_period
;
3366 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3368 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3370 local64_set(&hwc
->period_left
, 0);
3373 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3378 * combine freq adjustment with unthrottling to avoid two passes over the
3379 * events. At the same time, make sure, having freq events does not change
3380 * the rate of unthrottling as that would introduce bias.
3382 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3385 struct perf_event
*event
;
3386 struct hw_perf_event
*hwc
;
3387 u64 now
, period
= TICK_NSEC
;
3391 * only need to iterate over all events iff:
3392 * - context have events in frequency mode (needs freq adjust)
3393 * - there are events to unthrottle on this cpu
3395 if (!(ctx
->nr_freq
|| needs_unthr
))
3398 raw_spin_lock(&ctx
->lock
);
3399 perf_pmu_disable(ctx
->pmu
);
3401 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3402 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3405 if (!event_filter_match(event
))
3408 perf_pmu_disable(event
->pmu
);
3412 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3413 hwc
->interrupts
= 0;
3414 perf_log_throttle(event
, 1);
3415 event
->pmu
->start(event
, 0);
3418 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3422 * stop the event and update event->count
3424 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3426 now
= local64_read(&event
->count
);
3427 delta
= now
- hwc
->freq_count_stamp
;
3428 hwc
->freq_count_stamp
= now
;
3432 * reload only if value has changed
3433 * we have stopped the event so tell that
3434 * to perf_adjust_period() to avoid stopping it
3438 perf_adjust_period(event
, period
, delta
, false);
3440 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3442 perf_pmu_enable(event
->pmu
);
3445 perf_pmu_enable(ctx
->pmu
);
3446 raw_spin_unlock(&ctx
->lock
);
3450 * Round-robin a context's events:
3452 static void rotate_ctx(struct perf_event_context
*ctx
)
3455 * Rotate the first entry last of non-pinned groups. Rotation might be
3456 * disabled by the inheritance code.
3458 if (!ctx
->rotate_disable
)
3459 list_rotate_left(&ctx
->flexible_groups
);
3462 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3464 struct perf_event_context
*ctx
= NULL
;
3467 if (cpuctx
->ctx
.nr_events
) {
3468 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3472 ctx
= cpuctx
->task_ctx
;
3473 if (ctx
&& ctx
->nr_events
) {
3474 if (ctx
->nr_events
!= ctx
->nr_active
)
3481 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3482 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3484 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3486 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3488 rotate_ctx(&cpuctx
->ctx
);
3492 perf_event_sched_in(cpuctx
, ctx
, current
);
3494 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3495 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3501 void perf_event_task_tick(void)
3503 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3504 struct perf_event_context
*ctx
, *tmp
;
3507 WARN_ON(!irqs_disabled());
3509 __this_cpu_inc(perf_throttled_seq
);
3510 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3511 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3513 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3514 perf_adjust_freq_unthr_context(ctx
, throttled
);
3517 static int event_enable_on_exec(struct perf_event
*event
,
3518 struct perf_event_context
*ctx
)
3520 if (!event
->attr
.enable_on_exec
)
3523 event
->attr
.enable_on_exec
= 0;
3524 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3527 __perf_event_mark_enabled(event
);
3533 * Enable all of a task's events that have been marked enable-on-exec.
3534 * This expects task == current.
3536 static void perf_event_enable_on_exec(int ctxn
)
3538 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3539 enum event_type_t event_type
= 0;
3540 struct perf_cpu_context
*cpuctx
;
3541 struct perf_event
*event
;
3542 unsigned long flags
;
3545 local_irq_save(flags
);
3546 ctx
= current
->perf_event_ctxp
[ctxn
];
3547 if (!ctx
|| !ctx
->nr_events
)
3550 cpuctx
= __get_cpu_context(ctx
);
3551 perf_ctx_lock(cpuctx
, ctx
);
3552 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3553 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3554 enabled
|= event_enable_on_exec(event
, ctx
);
3555 event_type
|= get_event_type(event
);
3559 * Unclone and reschedule this context if we enabled any event.
3562 clone_ctx
= unclone_ctx(ctx
);
3563 ctx_resched(cpuctx
, ctx
, event_type
);
3565 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3567 perf_ctx_unlock(cpuctx
, ctx
);
3570 local_irq_restore(flags
);
3576 struct perf_read_data
{
3577 struct perf_event
*event
;
3582 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3584 u16 local_pkg
, event_pkg
;
3586 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3587 int local_cpu
= smp_processor_id();
3589 event_pkg
= topology_physical_package_id(event_cpu
);
3590 local_pkg
= topology_physical_package_id(local_cpu
);
3592 if (event_pkg
== local_pkg
)
3600 * Cross CPU call to read the hardware event
3602 static void __perf_event_read(void *info
)
3604 struct perf_read_data
*data
= info
;
3605 struct perf_event
*sub
, *event
= data
->event
;
3606 struct perf_event_context
*ctx
= event
->ctx
;
3607 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3608 struct pmu
*pmu
= event
->pmu
;
3611 * If this is a task context, we need to check whether it is
3612 * the current task context of this cpu. If not it has been
3613 * scheduled out before the smp call arrived. In that case
3614 * event->count would have been updated to a recent sample
3615 * when the event was scheduled out.
3617 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3620 raw_spin_lock(&ctx
->lock
);
3621 if (ctx
->is_active
) {
3622 update_context_time(ctx
);
3623 update_cgrp_time_from_event(event
);
3626 update_event_times(event
);
3627 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3636 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3640 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3641 update_event_times(sub
);
3642 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3644 * Use sibling's PMU rather than @event's since
3645 * sibling could be on different (eg: software) PMU.
3647 sub
->pmu
->read(sub
);
3651 data
->ret
= pmu
->commit_txn(pmu
);
3654 raw_spin_unlock(&ctx
->lock
);
3657 static inline u64
perf_event_count(struct perf_event
*event
)
3659 if (event
->pmu
->count
)
3660 return event
->pmu
->count(event
);
3662 return __perf_event_count(event
);
3666 * NMI-safe method to read a local event, that is an event that
3668 * - either for the current task, or for this CPU
3669 * - does not have inherit set, for inherited task events
3670 * will not be local and we cannot read them atomically
3671 * - must not have a pmu::count method
3673 int perf_event_read_local(struct perf_event
*event
, u64
*value
)
3675 unsigned long flags
;
3679 * Disabling interrupts avoids all counter scheduling (context
3680 * switches, timer based rotation and IPIs).
3682 local_irq_save(flags
);
3685 * It must not be an event with inherit set, we cannot read
3686 * all child counters from atomic context.
3688 if (event
->attr
.inherit
) {
3694 * It must not have a pmu::count method, those are not
3697 if (event
->pmu
->count
) {
3702 /* If this is a per-task event, it must be for current */
3703 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
3704 event
->hw
.target
!= current
) {
3709 /* If this is a per-CPU event, it must be for this CPU */
3710 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3711 event
->cpu
!= smp_processor_id()) {
3717 * If the event is currently on this CPU, its either a per-task event,
3718 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3721 if (event
->oncpu
== smp_processor_id())
3722 event
->pmu
->read(event
);
3724 *value
= local64_read(&event
->count
);
3726 local_irq_restore(flags
);
3731 static int perf_event_read(struct perf_event
*event
, bool group
)
3733 int event_cpu
, ret
= 0;
3736 * If event is enabled and currently active on a CPU, update the
3737 * value in the event structure:
3739 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3740 struct perf_read_data data
= {
3746 event_cpu
= READ_ONCE(event
->oncpu
);
3747 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3751 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
3754 * Purposely ignore the smp_call_function_single() return
3757 * If event_cpu isn't a valid CPU it means the event got
3758 * scheduled out and that will have updated the event count.
3760 * Therefore, either way, we'll have an up-to-date event count
3763 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
3766 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3767 struct perf_event_context
*ctx
= event
->ctx
;
3768 unsigned long flags
;
3770 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3772 * may read while context is not active
3773 * (e.g., thread is blocked), in that case
3774 * we cannot update context time
3776 if (ctx
->is_active
) {
3777 update_context_time(ctx
);
3778 update_cgrp_time_from_event(event
);
3781 update_group_times(event
);
3783 update_event_times(event
);
3784 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3791 * Initialize the perf_event context in a task_struct:
3793 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3795 raw_spin_lock_init(&ctx
->lock
);
3796 mutex_init(&ctx
->mutex
);
3797 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3798 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3799 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3800 INIT_LIST_HEAD(&ctx
->event_list
);
3801 atomic_set(&ctx
->refcount
, 1);
3804 static struct perf_event_context
*
3805 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3807 struct perf_event_context
*ctx
;
3809 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3813 __perf_event_init_context(ctx
);
3816 get_task_struct(task
);
3823 static struct task_struct
*
3824 find_lively_task_by_vpid(pid_t vpid
)
3826 struct task_struct
*task
;
3832 task
= find_task_by_vpid(vpid
);
3834 get_task_struct(task
);
3838 return ERR_PTR(-ESRCH
);
3844 * Returns a matching context with refcount and pincount.
3846 static struct perf_event_context
*
3847 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3848 struct perf_event
*event
)
3850 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3851 struct perf_cpu_context
*cpuctx
;
3852 void *task_ctx_data
= NULL
;
3853 unsigned long flags
;
3855 int cpu
= event
->cpu
;
3858 /* Must be root to operate on a CPU event: */
3859 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3860 return ERR_PTR(-EACCES
);
3862 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3871 ctxn
= pmu
->task_ctx_nr
;
3875 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3876 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3877 if (!task_ctx_data
) {
3884 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3886 clone_ctx
= unclone_ctx(ctx
);
3889 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3890 ctx
->task_ctx_data
= task_ctx_data
;
3891 task_ctx_data
= NULL
;
3893 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3898 ctx
= alloc_perf_context(pmu
, task
);
3903 if (task_ctx_data
) {
3904 ctx
->task_ctx_data
= task_ctx_data
;
3905 task_ctx_data
= NULL
;
3909 mutex_lock(&task
->perf_event_mutex
);
3911 * If it has already passed perf_event_exit_task().
3912 * we must see PF_EXITING, it takes this mutex too.
3914 if (task
->flags
& PF_EXITING
)
3916 else if (task
->perf_event_ctxp
[ctxn
])
3921 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3923 mutex_unlock(&task
->perf_event_mutex
);
3925 if (unlikely(err
)) {
3934 kfree(task_ctx_data
);
3938 kfree(task_ctx_data
);
3939 return ERR_PTR(err
);
3942 static void perf_event_free_filter(struct perf_event
*event
);
3943 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3945 static void free_event_rcu(struct rcu_head
*head
)
3947 struct perf_event
*event
;
3949 event
= container_of(head
, struct perf_event
, rcu_head
);
3951 put_pid_ns(event
->ns
);
3952 perf_event_free_filter(event
);
3956 static void ring_buffer_attach(struct perf_event
*event
,
3957 struct ring_buffer
*rb
);
3959 static void detach_sb_event(struct perf_event
*event
)
3961 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3963 raw_spin_lock(&pel
->lock
);
3964 list_del_rcu(&event
->sb_list
);
3965 raw_spin_unlock(&pel
->lock
);
3968 static bool is_sb_event(struct perf_event
*event
)
3970 struct perf_event_attr
*attr
= &event
->attr
;
3975 if (event
->attach_state
& PERF_ATTACH_TASK
)
3978 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3979 attr
->comm
|| attr
->comm_exec
||
3981 attr
->context_switch
)
3986 static void unaccount_pmu_sb_event(struct perf_event
*event
)
3988 if (is_sb_event(event
))
3989 detach_sb_event(event
);
3992 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3997 if (is_cgroup_event(event
))
3998 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
4001 #ifdef CONFIG_NO_HZ_FULL
4002 static DEFINE_SPINLOCK(nr_freq_lock
);
4005 static void unaccount_freq_event_nohz(void)
4007 #ifdef CONFIG_NO_HZ_FULL
4008 spin_lock(&nr_freq_lock
);
4009 if (atomic_dec_and_test(&nr_freq_events
))
4010 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
4011 spin_unlock(&nr_freq_lock
);
4015 static void unaccount_freq_event(void)
4017 if (tick_nohz_full_enabled())
4018 unaccount_freq_event_nohz();
4020 atomic_dec(&nr_freq_events
);
4023 static void unaccount_event(struct perf_event
*event
)
4030 if (event
->attach_state
& PERF_ATTACH_TASK
)
4032 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
4033 atomic_dec(&nr_mmap_events
);
4034 if (event
->attr
.comm
)
4035 atomic_dec(&nr_comm_events
);
4036 if (event
->attr
.namespaces
)
4037 atomic_dec(&nr_namespaces_events
);
4038 if (event
->attr
.task
)
4039 atomic_dec(&nr_task_events
);
4040 if (event
->attr
.freq
)
4041 unaccount_freq_event();
4042 if (event
->attr
.context_switch
) {
4044 atomic_dec(&nr_switch_events
);
4046 if (is_cgroup_event(event
))
4048 if (has_branch_stack(event
))
4052 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4053 schedule_delayed_work(&perf_sched_work
, HZ
);
4056 unaccount_event_cpu(event
, event
->cpu
);
4058 unaccount_pmu_sb_event(event
);
4061 static void perf_sched_delayed(struct work_struct
*work
)
4063 mutex_lock(&perf_sched_mutex
);
4064 if (atomic_dec_and_test(&perf_sched_count
))
4065 static_branch_disable(&perf_sched_events
);
4066 mutex_unlock(&perf_sched_mutex
);
4070 * The following implement mutual exclusion of events on "exclusive" pmus
4071 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4072 * at a time, so we disallow creating events that might conflict, namely:
4074 * 1) cpu-wide events in the presence of per-task events,
4075 * 2) per-task events in the presence of cpu-wide events,
4076 * 3) two matching events on the same context.
4078 * The former two cases are handled in the allocation path (perf_event_alloc(),
4079 * _free_event()), the latter -- before the first perf_install_in_context().
4081 static int exclusive_event_init(struct perf_event
*event
)
4083 struct pmu
*pmu
= event
->pmu
;
4085 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4089 * Prevent co-existence of per-task and cpu-wide events on the
4090 * same exclusive pmu.
4092 * Negative pmu::exclusive_cnt means there are cpu-wide
4093 * events on this "exclusive" pmu, positive means there are
4096 * Since this is called in perf_event_alloc() path, event::ctx
4097 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4098 * to mean "per-task event", because unlike other attach states it
4099 * never gets cleared.
4101 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4102 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4105 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4112 static void exclusive_event_destroy(struct perf_event
*event
)
4114 struct pmu
*pmu
= event
->pmu
;
4116 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4119 /* see comment in exclusive_event_init() */
4120 if (event
->attach_state
& PERF_ATTACH_TASK
)
4121 atomic_dec(&pmu
->exclusive_cnt
);
4123 atomic_inc(&pmu
->exclusive_cnt
);
4126 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4128 if ((e1
->pmu
== e2
->pmu
) &&
4129 (e1
->cpu
== e2
->cpu
||
4136 /* Called under the same ctx::mutex as perf_install_in_context() */
4137 static bool exclusive_event_installable(struct perf_event
*event
,
4138 struct perf_event_context
*ctx
)
4140 struct perf_event
*iter_event
;
4141 struct pmu
*pmu
= event
->pmu
;
4143 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4146 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4147 if (exclusive_event_match(iter_event
, event
))
4154 static void perf_addr_filters_splice(struct perf_event
*event
,
4155 struct list_head
*head
);
4157 static void _free_event(struct perf_event
*event
)
4159 irq_work_sync(&event
->pending
);
4161 unaccount_event(event
);
4165 * Can happen when we close an event with re-directed output.
4167 * Since we have a 0 refcount, perf_mmap_close() will skip
4168 * over us; possibly making our ring_buffer_put() the last.
4170 mutex_lock(&event
->mmap_mutex
);
4171 ring_buffer_attach(event
, NULL
);
4172 mutex_unlock(&event
->mmap_mutex
);
4175 if (is_cgroup_event(event
))
4176 perf_detach_cgroup(event
);
4178 if (!event
->parent
) {
4179 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4180 put_callchain_buffers();
4183 perf_event_free_bpf_prog(event
);
4184 perf_addr_filters_splice(event
, NULL
);
4185 kfree(event
->addr_filters_offs
);
4188 event
->destroy(event
);
4191 put_ctx(event
->ctx
);
4193 exclusive_event_destroy(event
);
4194 module_put(event
->pmu
->module
);
4196 call_rcu(&event
->rcu_head
, free_event_rcu
);
4200 * Used to free events which have a known refcount of 1, such as in error paths
4201 * where the event isn't exposed yet and inherited events.
4203 static void free_event(struct perf_event
*event
)
4205 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4206 "unexpected event refcount: %ld; ptr=%p\n",
4207 atomic_long_read(&event
->refcount
), event
)) {
4208 /* leak to avoid use-after-free */
4216 * Remove user event from the owner task.
4218 static void perf_remove_from_owner(struct perf_event
*event
)
4220 struct task_struct
*owner
;
4224 * Matches the smp_store_release() in perf_event_exit_task(). If we
4225 * observe !owner it means the list deletion is complete and we can
4226 * indeed free this event, otherwise we need to serialize on
4227 * owner->perf_event_mutex.
4229 owner
= lockless_dereference(event
->owner
);
4232 * Since delayed_put_task_struct() also drops the last
4233 * task reference we can safely take a new reference
4234 * while holding the rcu_read_lock().
4236 get_task_struct(owner
);
4242 * If we're here through perf_event_exit_task() we're already
4243 * holding ctx->mutex which would be an inversion wrt. the
4244 * normal lock order.
4246 * However we can safely take this lock because its the child
4249 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4252 * We have to re-check the event->owner field, if it is cleared
4253 * we raced with perf_event_exit_task(), acquiring the mutex
4254 * ensured they're done, and we can proceed with freeing the
4258 list_del_init(&event
->owner_entry
);
4259 smp_store_release(&event
->owner
, NULL
);
4261 mutex_unlock(&owner
->perf_event_mutex
);
4262 put_task_struct(owner
);
4266 static void put_event(struct perf_event
*event
)
4268 if (!atomic_long_dec_and_test(&event
->refcount
))
4275 * Kill an event dead; while event:refcount will preserve the event
4276 * object, it will not preserve its functionality. Once the last 'user'
4277 * gives up the object, we'll destroy the thing.
4279 int perf_event_release_kernel(struct perf_event
*event
)
4281 struct perf_event_context
*ctx
= event
->ctx
;
4282 struct perf_event
*child
, *tmp
;
4285 * If we got here through err_file: fput(event_file); we will not have
4286 * attached to a context yet.
4289 WARN_ON_ONCE(event
->attach_state
&
4290 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4294 if (!is_kernel_event(event
))
4295 perf_remove_from_owner(event
);
4297 ctx
= perf_event_ctx_lock(event
);
4298 WARN_ON_ONCE(ctx
->parent_ctx
);
4299 perf_remove_from_context(event
, DETACH_GROUP
);
4301 raw_spin_lock_irq(&ctx
->lock
);
4303 * Mark this event as STATE_DEAD, there is no external reference to it
4306 * Anybody acquiring event->child_mutex after the below loop _must_
4307 * also see this, most importantly inherit_event() which will avoid
4308 * placing more children on the list.
4310 * Thus this guarantees that we will in fact observe and kill _ALL_
4313 event
->state
= PERF_EVENT_STATE_DEAD
;
4314 raw_spin_unlock_irq(&ctx
->lock
);
4316 perf_event_ctx_unlock(event
, ctx
);
4319 mutex_lock(&event
->child_mutex
);
4320 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4323 * Cannot change, child events are not migrated, see the
4324 * comment with perf_event_ctx_lock_nested().
4326 ctx
= lockless_dereference(child
->ctx
);
4328 * Since child_mutex nests inside ctx::mutex, we must jump
4329 * through hoops. We start by grabbing a reference on the ctx.
4331 * Since the event cannot get freed while we hold the
4332 * child_mutex, the context must also exist and have a !0
4338 * Now that we have a ctx ref, we can drop child_mutex, and
4339 * acquire ctx::mutex without fear of it going away. Then we
4340 * can re-acquire child_mutex.
4342 mutex_unlock(&event
->child_mutex
);
4343 mutex_lock(&ctx
->mutex
);
4344 mutex_lock(&event
->child_mutex
);
4347 * Now that we hold ctx::mutex and child_mutex, revalidate our
4348 * state, if child is still the first entry, it didn't get freed
4349 * and we can continue doing so.
4351 tmp
= list_first_entry_or_null(&event
->child_list
,
4352 struct perf_event
, child_list
);
4354 perf_remove_from_context(child
, DETACH_GROUP
);
4355 list_del(&child
->child_list
);
4358 * This matches the refcount bump in inherit_event();
4359 * this can't be the last reference.
4364 mutex_unlock(&event
->child_mutex
);
4365 mutex_unlock(&ctx
->mutex
);
4369 mutex_unlock(&event
->child_mutex
);
4372 put_event(event
); /* Must be the 'last' reference */
4375 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4378 * Called when the last reference to the file is gone.
4380 static int perf_release(struct inode
*inode
, struct file
*file
)
4382 perf_event_release_kernel(file
->private_data
);
4386 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4388 struct perf_event
*child
;
4394 mutex_lock(&event
->child_mutex
);
4396 (void)perf_event_read(event
, false);
4397 total
+= perf_event_count(event
);
4399 *enabled
+= event
->total_time_enabled
+
4400 atomic64_read(&event
->child_total_time_enabled
);
4401 *running
+= event
->total_time_running
+
4402 atomic64_read(&event
->child_total_time_running
);
4404 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4405 (void)perf_event_read(child
, false);
4406 total
+= perf_event_count(child
);
4407 *enabled
+= child
->total_time_enabled
;
4408 *running
+= child
->total_time_running
;
4410 mutex_unlock(&event
->child_mutex
);
4414 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4416 static int __perf_read_group_add(struct perf_event
*leader
,
4417 u64 read_format
, u64
*values
)
4419 struct perf_event_context
*ctx
= leader
->ctx
;
4420 struct perf_event
*sub
;
4421 unsigned long flags
;
4422 int n
= 1; /* skip @nr */
4425 ret
= perf_event_read(leader
, true);
4430 * Since we co-schedule groups, {enabled,running} times of siblings
4431 * will be identical to those of the leader, so we only publish one
4434 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4435 values
[n
++] += leader
->total_time_enabled
+
4436 atomic64_read(&leader
->child_total_time_enabled
);
4439 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4440 values
[n
++] += leader
->total_time_running
+
4441 atomic64_read(&leader
->child_total_time_running
);
4445 * Write {count,id} tuples for every sibling.
4447 values
[n
++] += perf_event_count(leader
);
4448 if (read_format
& PERF_FORMAT_ID
)
4449 values
[n
++] = primary_event_id(leader
);
4451 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
4453 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4454 values
[n
++] += perf_event_count(sub
);
4455 if (read_format
& PERF_FORMAT_ID
)
4456 values
[n
++] = primary_event_id(sub
);
4459 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
4463 static int perf_read_group(struct perf_event
*event
,
4464 u64 read_format
, char __user
*buf
)
4466 struct perf_event
*leader
= event
->group_leader
, *child
;
4467 struct perf_event_context
*ctx
= leader
->ctx
;
4471 lockdep_assert_held(&ctx
->mutex
);
4473 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4477 values
[0] = 1 + leader
->nr_siblings
;
4480 * By locking the child_mutex of the leader we effectively
4481 * lock the child list of all siblings.. XXX explain how.
4483 mutex_lock(&leader
->child_mutex
);
4485 ret
= __perf_read_group_add(leader
, read_format
, values
);
4489 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4490 ret
= __perf_read_group_add(child
, read_format
, values
);
4495 mutex_unlock(&leader
->child_mutex
);
4497 ret
= event
->read_size
;
4498 if (copy_to_user(buf
, values
, event
->read_size
))
4503 mutex_unlock(&leader
->child_mutex
);
4509 static int perf_read_one(struct perf_event
*event
,
4510 u64 read_format
, char __user
*buf
)
4512 u64 enabled
, running
;
4516 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4517 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4518 values
[n
++] = enabled
;
4519 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4520 values
[n
++] = running
;
4521 if (read_format
& PERF_FORMAT_ID
)
4522 values
[n
++] = primary_event_id(event
);
4524 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4527 return n
* sizeof(u64
);
4530 static bool is_event_hup(struct perf_event
*event
)
4534 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4537 mutex_lock(&event
->child_mutex
);
4538 no_children
= list_empty(&event
->child_list
);
4539 mutex_unlock(&event
->child_mutex
);
4544 * Read the performance event - simple non blocking version for now
4547 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4549 u64 read_format
= event
->attr
.read_format
;
4553 * Return end-of-file for a read on a event that is in
4554 * error state (i.e. because it was pinned but it couldn't be
4555 * scheduled on to the CPU at some point).
4557 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4560 if (count
< event
->read_size
)
4563 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4564 if (read_format
& PERF_FORMAT_GROUP
)
4565 ret
= perf_read_group(event
, read_format
, buf
);
4567 ret
= perf_read_one(event
, read_format
, buf
);
4573 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4575 struct perf_event
*event
= file
->private_data
;
4576 struct perf_event_context
*ctx
;
4579 ctx
= perf_event_ctx_lock(event
);
4580 ret
= __perf_read(event
, buf
, count
);
4581 perf_event_ctx_unlock(event
, ctx
);
4586 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4588 struct perf_event
*event
= file
->private_data
;
4589 struct ring_buffer
*rb
;
4590 unsigned int events
= POLLHUP
;
4592 poll_wait(file
, &event
->waitq
, wait
);
4594 if (is_event_hup(event
))
4598 * Pin the event->rb by taking event->mmap_mutex; otherwise
4599 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4601 mutex_lock(&event
->mmap_mutex
);
4604 events
= atomic_xchg(&rb
->poll
, 0);
4605 mutex_unlock(&event
->mmap_mutex
);
4609 static void _perf_event_reset(struct perf_event
*event
)
4611 (void)perf_event_read(event
, false);
4612 local64_set(&event
->count
, 0);
4613 perf_event_update_userpage(event
);
4617 * Holding the top-level event's child_mutex means that any
4618 * descendant process that has inherited this event will block
4619 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4620 * task existence requirements of perf_event_enable/disable.
4622 static void perf_event_for_each_child(struct perf_event
*event
,
4623 void (*func
)(struct perf_event
*))
4625 struct perf_event
*child
;
4627 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4629 mutex_lock(&event
->child_mutex
);
4631 list_for_each_entry(child
, &event
->child_list
, child_list
)
4633 mutex_unlock(&event
->child_mutex
);
4636 static void perf_event_for_each(struct perf_event
*event
,
4637 void (*func
)(struct perf_event
*))
4639 struct perf_event_context
*ctx
= event
->ctx
;
4640 struct perf_event
*sibling
;
4642 lockdep_assert_held(&ctx
->mutex
);
4644 event
= event
->group_leader
;
4646 perf_event_for_each_child(event
, func
);
4647 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4648 perf_event_for_each_child(sibling
, func
);
4651 static void __perf_event_period(struct perf_event
*event
,
4652 struct perf_cpu_context
*cpuctx
,
4653 struct perf_event_context
*ctx
,
4656 u64 value
= *((u64
*)info
);
4659 if (event
->attr
.freq
) {
4660 event
->attr
.sample_freq
= value
;
4662 event
->attr
.sample_period
= value
;
4663 event
->hw
.sample_period
= value
;
4666 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4668 perf_pmu_disable(ctx
->pmu
);
4670 * We could be throttled; unthrottle now to avoid the tick
4671 * trying to unthrottle while we already re-started the event.
4673 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4674 event
->hw
.interrupts
= 0;
4675 perf_log_throttle(event
, 1);
4677 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4680 local64_set(&event
->hw
.period_left
, 0);
4683 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4684 perf_pmu_enable(ctx
->pmu
);
4688 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4692 if (!is_sampling_event(event
))
4695 if (copy_from_user(&value
, arg
, sizeof(value
)))
4701 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4704 event_function_call(event
, __perf_event_period
, &value
);
4709 static const struct file_operations perf_fops
;
4711 static inline int perf_fget_light(int fd
, struct fd
*p
)
4713 struct fd f
= fdget(fd
);
4717 if (f
.file
->f_op
!= &perf_fops
) {
4725 static int perf_event_set_output(struct perf_event
*event
,
4726 struct perf_event
*output_event
);
4727 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4728 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4730 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4732 void (*func
)(struct perf_event
*);
4736 case PERF_EVENT_IOC_ENABLE
:
4737 func
= _perf_event_enable
;
4739 case PERF_EVENT_IOC_DISABLE
:
4740 func
= _perf_event_disable
;
4742 case PERF_EVENT_IOC_RESET
:
4743 func
= _perf_event_reset
;
4746 case PERF_EVENT_IOC_REFRESH
:
4747 return _perf_event_refresh(event
, arg
);
4749 case PERF_EVENT_IOC_PERIOD
:
4750 return perf_event_period(event
, (u64 __user
*)arg
);
4752 case PERF_EVENT_IOC_ID
:
4754 u64 id
= primary_event_id(event
);
4756 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4761 case PERF_EVENT_IOC_SET_OUTPUT
:
4765 struct perf_event
*output_event
;
4767 ret
= perf_fget_light(arg
, &output
);
4770 output_event
= output
.file
->private_data
;
4771 ret
= perf_event_set_output(event
, output_event
);
4774 ret
= perf_event_set_output(event
, NULL
);
4779 case PERF_EVENT_IOC_SET_FILTER
:
4780 return perf_event_set_filter(event
, (void __user
*)arg
);
4782 case PERF_EVENT_IOC_SET_BPF
:
4783 return perf_event_set_bpf_prog(event
, arg
);
4785 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4786 struct ring_buffer
*rb
;
4789 rb
= rcu_dereference(event
->rb
);
4790 if (!rb
|| !rb
->nr_pages
) {
4794 rb_toggle_paused(rb
, !!arg
);
4802 if (flags
& PERF_IOC_FLAG_GROUP
)
4803 perf_event_for_each(event
, func
);
4805 perf_event_for_each_child(event
, func
);
4810 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4812 struct perf_event
*event
= file
->private_data
;
4813 struct perf_event_context
*ctx
;
4816 ctx
= perf_event_ctx_lock(event
);
4817 ret
= _perf_ioctl(event
, cmd
, arg
);
4818 perf_event_ctx_unlock(event
, ctx
);
4823 #ifdef CONFIG_COMPAT
4824 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4827 switch (_IOC_NR(cmd
)) {
4828 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4829 case _IOC_NR(PERF_EVENT_IOC_ID
):
4830 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4831 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4832 cmd
&= ~IOCSIZE_MASK
;
4833 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4837 return perf_ioctl(file
, cmd
, arg
);
4840 # define perf_compat_ioctl NULL
4843 int perf_event_task_enable(void)
4845 struct perf_event_context
*ctx
;
4846 struct perf_event
*event
;
4848 mutex_lock(¤t
->perf_event_mutex
);
4849 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4850 ctx
= perf_event_ctx_lock(event
);
4851 perf_event_for_each_child(event
, _perf_event_enable
);
4852 perf_event_ctx_unlock(event
, ctx
);
4854 mutex_unlock(¤t
->perf_event_mutex
);
4859 int perf_event_task_disable(void)
4861 struct perf_event_context
*ctx
;
4862 struct perf_event
*event
;
4864 mutex_lock(¤t
->perf_event_mutex
);
4865 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4866 ctx
= perf_event_ctx_lock(event
);
4867 perf_event_for_each_child(event
, _perf_event_disable
);
4868 perf_event_ctx_unlock(event
, ctx
);
4870 mutex_unlock(¤t
->perf_event_mutex
);
4875 static int perf_event_index(struct perf_event
*event
)
4877 if (event
->hw
.state
& PERF_HES_STOPPED
)
4880 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4883 return event
->pmu
->event_idx(event
);
4886 static void calc_timer_values(struct perf_event
*event
,
4893 *now
= perf_clock();
4894 ctx_time
= event
->shadow_ctx_time
+ *now
;
4895 *enabled
= ctx_time
- event
->tstamp_enabled
;
4896 *running
= ctx_time
- event
->tstamp_running
;
4899 static void perf_event_init_userpage(struct perf_event
*event
)
4901 struct perf_event_mmap_page
*userpg
;
4902 struct ring_buffer
*rb
;
4905 rb
= rcu_dereference(event
->rb
);
4909 userpg
= rb
->user_page
;
4911 /* Allow new userspace to detect that bit 0 is deprecated */
4912 userpg
->cap_bit0_is_deprecated
= 1;
4913 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4914 userpg
->data_offset
= PAGE_SIZE
;
4915 userpg
->data_size
= perf_data_size(rb
);
4921 void __weak
arch_perf_update_userpage(
4922 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4927 * Callers need to ensure there can be no nesting of this function, otherwise
4928 * the seqlock logic goes bad. We can not serialize this because the arch
4929 * code calls this from NMI context.
4931 void perf_event_update_userpage(struct perf_event
*event
)
4933 struct perf_event_mmap_page
*userpg
;
4934 struct ring_buffer
*rb
;
4935 u64 enabled
, running
, now
;
4938 rb
= rcu_dereference(event
->rb
);
4943 * compute total_time_enabled, total_time_running
4944 * based on snapshot values taken when the event
4945 * was last scheduled in.
4947 * we cannot simply called update_context_time()
4948 * because of locking issue as we can be called in
4951 calc_timer_values(event
, &now
, &enabled
, &running
);
4953 userpg
= rb
->user_page
;
4955 * Disable preemption so as to not let the corresponding user-space
4956 * spin too long if we get preempted.
4961 userpg
->index
= perf_event_index(event
);
4962 userpg
->offset
= perf_event_count(event
);
4964 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4966 userpg
->time_enabled
= enabled
+
4967 atomic64_read(&event
->child_total_time_enabled
);
4969 userpg
->time_running
= running
+
4970 atomic64_read(&event
->child_total_time_running
);
4972 arch_perf_update_userpage(event
, userpg
, now
);
4981 static int perf_mmap_fault(struct vm_fault
*vmf
)
4983 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
4984 struct ring_buffer
*rb
;
4985 int ret
= VM_FAULT_SIGBUS
;
4987 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4988 if (vmf
->pgoff
== 0)
4994 rb
= rcu_dereference(event
->rb
);
4998 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
5001 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
5005 get_page(vmf
->page
);
5006 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
5007 vmf
->page
->index
= vmf
->pgoff
;
5016 static void ring_buffer_attach(struct perf_event
*event
,
5017 struct ring_buffer
*rb
)
5019 struct ring_buffer
*old_rb
= NULL
;
5020 unsigned long flags
;
5024 * Should be impossible, we set this when removing
5025 * event->rb_entry and wait/clear when adding event->rb_entry.
5027 WARN_ON_ONCE(event
->rcu_pending
);
5030 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
5031 list_del_rcu(&event
->rb_entry
);
5032 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
5034 event
->rcu_batches
= get_state_synchronize_rcu();
5035 event
->rcu_pending
= 1;
5039 if (event
->rcu_pending
) {
5040 cond_synchronize_rcu(event
->rcu_batches
);
5041 event
->rcu_pending
= 0;
5044 spin_lock_irqsave(&rb
->event_lock
, flags
);
5045 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5046 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5050 * Avoid racing with perf_mmap_close(AUX): stop the event
5051 * before swizzling the event::rb pointer; if it's getting
5052 * unmapped, its aux_mmap_count will be 0 and it won't
5053 * restart. See the comment in __perf_pmu_output_stop().
5055 * Data will inevitably be lost when set_output is done in
5056 * mid-air, but then again, whoever does it like this is
5057 * not in for the data anyway.
5060 perf_event_stop(event
, 0);
5062 rcu_assign_pointer(event
->rb
, rb
);
5065 ring_buffer_put(old_rb
);
5067 * Since we detached before setting the new rb, so that we
5068 * could attach the new rb, we could have missed a wakeup.
5071 wake_up_all(&event
->waitq
);
5075 static void ring_buffer_wakeup(struct perf_event
*event
)
5077 struct ring_buffer
*rb
;
5080 rb
= rcu_dereference(event
->rb
);
5082 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5083 wake_up_all(&event
->waitq
);
5088 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5090 struct ring_buffer
*rb
;
5093 rb
= rcu_dereference(event
->rb
);
5095 if (!atomic_inc_not_zero(&rb
->refcount
))
5103 void ring_buffer_put(struct ring_buffer
*rb
)
5105 if (!atomic_dec_and_test(&rb
->refcount
))
5108 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5110 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5113 static void perf_mmap_open(struct vm_area_struct
*vma
)
5115 struct perf_event
*event
= vma
->vm_file
->private_data
;
5117 atomic_inc(&event
->mmap_count
);
5118 atomic_inc(&event
->rb
->mmap_count
);
5121 atomic_inc(&event
->rb
->aux_mmap_count
);
5123 if (event
->pmu
->event_mapped
)
5124 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5127 static void perf_pmu_output_stop(struct perf_event
*event
);
5130 * A buffer can be mmap()ed multiple times; either directly through the same
5131 * event, or through other events by use of perf_event_set_output().
5133 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5134 * the buffer here, where we still have a VM context. This means we need
5135 * to detach all events redirecting to us.
5137 static void perf_mmap_close(struct vm_area_struct
*vma
)
5139 struct perf_event
*event
= vma
->vm_file
->private_data
;
5141 struct ring_buffer
*rb
= ring_buffer_get(event
);
5142 struct user_struct
*mmap_user
= rb
->mmap_user
;
5143 int mmap_locked
= rb
->mmap_locked
;
5144 unsigned long size
= perf_data_size(rb
);
5146 if (event
->pmu
->event_unmapped
)
5147 event
->pmu
->event_unmapped(event
, vma
->vm_mm
);
5150 * rb->aux_mmap_count will always drop before rb->mmap_count and
5151 * event->mmap_count, so it is ok to use event->mmap_mutex to
5152 * serialize with perf_mmap here.
5154 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5155 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5157 * Stop all AUX events that are writing to this buffer,
5158 * so that we can free its AUX pages and corresponding PMU
5159 * data. Note that after rb::aux_mmap_count dropped to zero,
5160 * they won't start any more (see perf_aux_output_begin()).
5162 perf_pmu_output_stop(event
);
5164 /* now it's safe to free the pages */
5165 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5166 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5168 /* this has to be the last one */
5170 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5172 mutex_unlock(&event
->mmap_mutex
);
5175 atomic_dec(&rb
->mmap_count
);
5177 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5180 ring_buffer_attach(event
, NULL
);
5181 mutex_unlock(&event
->mmap_mutex
);
5183 /* If there's still other mmap()s of this buffer, we're done. */
5184 if (atomic_read(&rb
->mmap_count
))
5188 * No other mmap()s, detach from all other events that might redirect
5189 * into the now unreachable buffer. Somewhat complicated by the
5190 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5194 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5195 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5197 * This event is en-route to free_event() which will
5198 * detach it and remove it from the list.
5204 mutex_lock(&event
->mmap_mutex
);
5206 * Check we didn't race with perf_event_set_output() which can
5207 * swizzle the rb from under us while we were waiting to
5208 * acquire mmap_mutex.
5210 * If we find a different rb; ignore this event, a next
5211 * iteration will no longer find it on the list. We have to
5212 * still restart the iteration to make sure we're not now
5213 * iterating the wrong list.
5215 if (event
->rb
== rb
)
5216 ring_buffer_attach(event
, NULL
);
5218 mutex_unlock(&event
->mmap_mutex
);
5222 * Restart the iteration; either we're on the wrong list or
5223 * destroyed its integrity by doing a deletion.
5230 * It could be there's still a few 0-ref events on the list; they'll
5231 * get cleaned up by free_event() -- they'll also still have their
5232 * ref on the rb and will free it whenever they are done with it.
5234 * Aside from that, this buffer is 'fully' detached and unmapped,
5235 * undo the VM accounting.
5238 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5239 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5240 free_uid(mmap_user
);
5243 ring_buffer_put(rb
); /* could be last */
5246 static const struct vm_operations_struct perf_mmap_vmops
= {
5247 .open
= perf_mmap_open
,
5248 .close
= perf_mmap_close
, /* non mergable */
5249 .fault
= perf_mmap_fault
,
5250 .page_mkwrite
= perf_mmap_fault
,
5253 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5255 struct perf_event
*event
= file
->private_data
;
5256 unsigned long user_locked
, user_lock_limit
;
5257 struct user_struct
*user
= current_user();
5258 unsigned long locked
, lock_limit
;
5259 struct ring_buffer
*rb
= NULL
;
5260 unsigned long vma_size
;
5261 unsigned long nr_pages
;
5262 long user_extra
= 0, extra
= 0;
5263 int ret
= 0, flags
= 0;
5266 * Don't allow mmap() of inherited per-task counters. This would
5267 * create a performance issue due to all children writing to the
5270 if (event
->cpu
== -1 && event
->attr
.inherit
)
5273 if (!(vma
->vm_flags
& VM_SHARED
))
5276 vma_size
= vma
->vm_end
- vma
->vm_start
;
5278 if (vma
->vm_pgoff
== 0) {
5279 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5282 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5283 * mapped, all subsequent mappings should have the same size
5284 * and offset. Must be above the normal perf buffer.
5286 u64 aux_offset
, aux_size
;
5291 nr_pages
= vma_size
/ PAGE_SIZE
;
5293 mutex_lock(&event
->mmap_mutex
);
5300 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
5301 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
5303 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5306 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5309 /* already mapped with a different offset */
5310 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5313 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5316 /* already mapped with a different size */
5317 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5320 if (!is_power_of_2(nr_pages
))
5323 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5326 if (rb_has_aux(rb
)) {
5327 atomic_inc(&rb
->aux_mmap_count
);
5332 atomic_set(&rb
->aux_mmap_count
, 1);
5333 user_extra
= nr_pages
;
5339 * If we have rb pages ensure they're a power-of-two number, so we
5340 * can do bitmasks instead of modulo.
5342 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5345 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5348 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5350 mutex_lock(&event
->mmap_mutex
);
5352 if (event
->rb
->nr_pages
!= nr_pages
) {
5357 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5359 * Raced against perf_mmap_close() through
5360 * perf_event_set_output(). Try again, hope for better
5363 mutex_unlock(&event
->mmap_mutex
);
5370 user_extra
= nr_pages
+ 1;
5373 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5376 * Increase the limit linearly with more CPUs:
5378 user_lock_limit
*= num_online_cpus();
5380 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5382 if (user_locked
> user_lock_limit
)
5383 extra
= user_locked
- user_lock_limit
;
5385 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5386 lock_limit
>>= PAGE_SHIFT
;
5387 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5389 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5390 !capable(CAP_IPC_LOCK
)) {
5395 WARN_ON(!rb
&& event
->rb
);
5397 if (vma
->vm_flags
& VM_WRITE
)
5398 flags
|= RING_BUFFER_WRITABLE
;
5401 rb
= rb_alloc(nr_pages
,
5402 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5410 atomic_set(&rb
->mmap_count
, 1);
5411 rb
->mmap_user
= get_current_user();
5412 rb
->mmap_locked
= extra
;
5414 ring_buffer_attach(event
, rb
);
5416 perf_event_init_userpage(event
);
5417 perf_event_update_userpage(event
);
5419 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5420 event
->attr
.aux_watermark
, flags
);
5422 rb
->aux_mmap_locked
= extra
;
5427 atomic_long_add(user_extra
, &user
->locked_vm
);
5428 vma
->vm_mm
->pinned_vm
+= extra
;
5430 atomic_inc(&event
->mmap_count
);
5432 atomic_dec(&rb
->mmap_count
);
5435 mutex_unlock(&event
->mmap_mutex
);
5438 * Since pinned accounting is per vm we cannot allow fork() to copy our
5441 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5442 vma
->vm_ops
= &perf_mmap_vmops
;
5444 if (event
->pmu
->event_mapped
)
5445 event
->pmu
->event_mapped(event
, vma
->vm_mm
);
5450 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5452 struct inode
*inode
= file_inode(filp
);
5453 struct perf_event
*event
= filp
->private_data
;
5457 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5458 inode_unlock(inode
);
5466 static const struct file_operations perf_fops
= {
5467 .llseek
= no_llseek
,
5468 .release
= perf_release
,
5471 .unlocked_ioctl
= perf_ioctl
,
5472 .compat_ioctl
= perf_compat_ioctl
,
5474 .fasync
= perf_fasync
,
5480 * If there's data, ensure we set the poll() state and publish everything
5481 * to user-space before waking everybody up.
5484 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5486 /* only the parent has fasync state */
5488 event
= event
->parent
;
5489 return &event
->fasync
;
5492 void perf_event_wakeup(struct perf_event
*event
)
5494 ring_buffer_wakeup(event
);
5496 if (event
->pending_kill
) {
5497 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5498 event
->pending_kill
= 0;
5502 static void perf_pending_event(struct irq_work
*entry
)
5504 struct perf_event
*event
= container_of(entry
,
5505 struct perf_event
, pending
);
5508 rctx
= perf_swevent_get_recursion_context();
5510 * If we 'fail' here, that's OK, it means recursion is already disabled
5511 * and we won't recurse 'further'.
5514 if (event
->pending_disable
) {
5515 event
->pending_disable
= 0;
5516 perf_event_disable_local(event
);
5519 if (event
->pending_wakeup
) {
5520 event
->pending_wakeup
= 0;
5521 perf_event_wakeup(event
);
5525 perf_swevent_put_recursion_context(rctx
);
5529 * We assume there is only KVM supporting the callbacks.
5530 * Later on, we might change it to a list if there is
5531 * another virtualization implementation supporting the callbacks.
5533 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5535 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5537 perf_guest_cbs
= cbs
;
5540 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5542 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5544 perf_guest_cbs
= NULL
;
5547 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5550 perf_output_sample_regs(struct perf_output_handle
*handle
,
5551 struct pt_regs
*regs
, u64 mask
)
5554 DECLARE_BITMAP(_mask
, 64);
5556 bitmap_from_u64(_mask
, mask
);
5557 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5560 val
= perf_reg_value(regs
, bit
);
5561 perf_output_put(handle
, val
);
5565 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5566 struct pt_regs
*regs
,
5567 struct pt_regs
*regs_user_copy
)
5569 if (user_mode(regs
)) {
5570 regs_user
->abi
= perf_reg_abi(current
);
5571 regs_user
->regs
= regs
;
5572 } else if (current
->mm
) {
5573 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5575 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5576 regs_user
->regs
= NULL
;
5580 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5581 struct pt_regs
*regs
)
5583 regs_intr
->regs
= regs
;
5584 regs_intr
->abi
= perf_reg_abi(current
);
5589 * Get remaining task size from user stack pointer.
5591 * It'd be better to take stack vma map and limit this more
5592 * precisly, but there's no way to get it safely under interrupt,
5593 * so using TASK_SIZE as limit.
5595 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5597 unsigned long addr
= perf_user_stack_pointer(regs
);
5599 if (!addr
|| addr
>= TASK_SIZE
)
5602 return TASK_SIZE
- addr
;
5606 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5607 struct pt_regs
*regs
)
5611 /* No regs, no stack pointer, no dump. */
5616 * Check if we fit in with the requested stack size into the:
5618 * If we don't, we limit the size to the TASK_SIZE.
5620 * - remaining sample size
5621 * If we don't, we customize the stack size to
5622 * fit in to the remaining sample size.
5625 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5626 stack_size
= min(stack_size
, (u16
) task_size
);
5628 /* Current header size plus static size and dynamic size. */
5629 header_size
+= 2 * sizeof(u64
);
5631 /* Do we fit in with the current stack dump size? */
5632 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5634 * If we overflow the maximum size for the sample,
5635 * we customize the stack dump size to fit in.
5637 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5638 stack_size
= round_up(stack_size
, sizeof(u64
));
5645 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5646 struct pt_regs
*regs
)
5648 /* Case of a kernel thread, nothing to dump */
5651 perf_output_put(handle
, size
);
5660 * - the size requested by user or the best one we can fit
5661 * in to the sample max size
5663 * - user stack dump data
5665 * - the actual dumped size
5669 perf_output_put(handle
, dump_size
);
5672 sp
= perf_user_stack_pointer(regs
);
5673 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5674 dyn_size
= dump_size
- rem
;
5676 perf_output_skip(handle
, rem
);
5679 perf_output_put(handle
, dyn_size
);
5683 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5684 struct perf_sample_data
*data
,
5685 struct perf_event
*event
)
5687 u64 sample_type
= event
->attr
.sample_type
;
5689 data
->type
= sample_type
;
5690 header
->size
+= event
->id_header_size
;
5692 if (sample_type
& PERF_SAMPLE_TID
) {
5693 /* namespace issues */
5694 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5695 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5698 if (sample_type
& PERF_SAMPLE_TIME
)
5699 data
->time
= perf_event_clock(event
);
5701 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5702 data
->id
= primary_event_id(event
);
5704 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5705 data
->stream_id
= event
->id
;
5707 if (sample_type
& PERF_SAMPLE_CPU
) {
5708 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5709 data
->cpu_entry
.reserved
= 0;
5713 void perf_event_header__init_id(struct perf_event_header
*header
,
5714 struct perf_sample_data
*data
,
5715 struct perf_event
*event
)
5717 if (event
->attr
.sample_id_all
)
5718 __perf_event_header__init_id(header
, data
, event
);
5721 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5722 struct perf_sample_data
*data
)
5724 u64 sample_type
= data
->type
;
5726 if (sample_type
& PERF_SAMPLE_TID
)
5727 perf_output_put(handle
, data
->tid_entry
);
5729 if (sample_type
& PERF_SAMPLE_TIME
)
5730 perf_output_put(handle
, data
->time
);
5732 if (sample_type
& PERF_SAMPLE_ID
)
5733 perf_output_put(handle
, data
->id
);
5735 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5736 perf_output_put(handle
, data
->stream_id
);
5738 if (sample_type
& PERF_SAMPLE_CPU
)
5739 perf_output_put(handle
, data
->cpu_entry
);
5741 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5742 perf_output_put(handle
, data
->id
);
5745 void perf_event__output_id_sample(struct perf_event
*event
,
5746 struct perf_output_handle
*handle
,
5747 struct perf_sample_data
*sample
)
5749 if (event
->attr
.sample_id_all
)
5750 __perf_event__output_id_sample(handle
, sample
);
5753 static void perf_output_read_one(struct perf_output_handle
*handle
,
5754 struct perf_event
*event
,
5755 u64 enabled
, u64 running
)
5757 u64 read_format
= event
->attr
.read_format
;
5761 values
[n
++] = perf_event_count(event
);
5762 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5763 values
[n
++] = enabled
+
5764 atomic64_read(&event
->child_total_time_enabled
);
5766 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5767 values
[n
++] = running
+
5768 atomic64_read(&event
->child_total_time_running
);
5770 if (read_format
& PERF_FORMAT_ID
)
5771 values
[n
++] = primary_event_id(event
);
5773 __output_copy(handle
, values
, n
* sizeof(u64
));
5776 static void perf_output_read_group(struct perf_output_handle
*handle
,
5777 struct perf_event
*event
,
5778 u64 enabled
, u64 running
)
5780 struct perf_event
*leader
= event
->group_leader
, *sub
;
5781 u64 read_format
= event
->attr
.read_format
;
5785 values
[n
++] = 1 + leader
->nr_siblings
;
5787 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5788 values
[n
++] = enabled
;
5790 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5791 values
[n
++] = running
;
5793 if (leader
!= event
)
5794 leader
->pmu
->read(leader
);
5796 values
[n
++] = perf_event_count(leader
);
5797 if (read_format
& PERF_FORMAT_ID
)
5798 values
[n
++] = primary_event_id(leader
);
5800 __output_copy(handle
, values
, n
* sizeof(u64
));
5802 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5805 if ((sub
!= event
) &&
5806 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5807 sub
->pmu
->read(sub
);
5809 values
[n
++] = perf_event_count(sub
);
5810 if (read_format
& PERF_FORMAT_ID
)
5811 values
[n
++] = primary_event_id(sub
);
5813 __output_copy(handle
, values
, n
* sizeof(u64
));
5817 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5818 PERF_FORMAT_TOTAL_TIME_RUNNING)
5821 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
5823 * The problem is that its both hard and excessively expensive to iterate the
5824 * child list, not to mention that its impossible to IPI the children running
5825 * on another CPU, from interrupt/NMI context.
5827 static void perf_output_read(struct perf_output_handle
*handle
,
5828 struct perf_event
*event
)
5830 u64 enabled
= 0, running
= 0, now
;
5831 u64 read_format
= event
->attr
.read_format
;
5834 * compute total_time_enabled, total_time_running
5835 * based on snapshot values taken when the event
5836 * was last scheduled in.
5838 * we cannot simply called update_context_time()
5839 * because of locking issue as we are called in
5842 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5843 calc_timer_values(event
, &now
, &enabled
, &running
);
5845 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5846 perf_output_read_group(handle
, event
, enabled
, running
);
5848 perf_output_read_one(handle
, event
, enabled
, running
);
5851 void perf_output_sample(struct perf_output_handle
*handle
,
5852 struct perf_event_header
*header
,
5853 struct perf_sample_data
*data
,
5854 struct perf_event
*event
)
5856 u64 sample_type
= data
->type
;
5858 perf_output_put(handle
, *header
);
5860 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5861 perf_output_put(handle
, data
->id
);
5863 if (sample_type
& PERF_SAMPLE_IP
)
5864 perf_output_put(handle
, data
->ip
);
5866 if (sample_type
& PERF_SAMPLE_TID
)
5867 perf_output_put(handle
, data
->tid_entry
);
5869 if (sample_type
& PERF_SAMPLE_TIME
)
5870 perf_output_put(handle
, data
->time
);
5872 if (sample_type
& PERF_SAMPLE_ADDR
)
5873 perf_output_put(handle
, data
->addr
);
5875 if (sample_type
& PERF_SAMPLE_ID
)
5876 perf_output_put(handle
, data
->id
);
5878 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5879 perf_output_put(handle
, data
->stream_id
);
5881 if (sample_type
& PERF_SAMPLE_CPU
)
5882 perf_output_put(handle
, data
->cpu_entry
);
5884 if (sample_type
& PERF_SAMPLE_PERIOD
)
5885 perf_output_put(handle
, data
->period
);
5887 if (sample_type
& PERF_SAMPLE_READ
)
5888 perf_output_read(handle
, event
);
5890 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5891 if (data
->callchain
) {
5894 if (data
->callchain
)
5895 size
+= data
->callchain
->nr
;
5897 size
*= sizeof(u64
);
5899 __output_copy(handle
, data
->callchain
, size
);
5902 perf_output_put(handle
, nr
);
5906 if (sample_type
& PERF_SAMPLE_RAW
) {
5907 struct perf_raw_record
*raw
= data
->raw
;
5910 struct perf_raw_frag
*frag
= &raw
->frag
;
5912 perf_output_put(handle
, raw
->size
);
5915 __output_custom(handle
, frag
->copy
,
5916 frag
->data
, frag
->size
);
5918 __output_copy(handle
, frag
->data
,
5921 if (perf_raw_frag_last(frag
))
5926 __output_skip(handle
, NULL
, frag
->pad
);
5932 .size
= sizeof(u32
),
5935 perf_output_put(handle
, raw
);
5939 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5940 if (data
->br_stack
) {
5943 size
= data
->br_stack
->nr
5944 * sizeof(struct perf_branch_entry
);
5946 perf_output_put(handle
, data
->br_stack
->nr
);
5947 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5950 * we always store at least the value of nr
5953 perf_output_put(handle
, nr
);
5957 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5958 u64 abi
= data
->regs_user
.abi
;
5961 * If there are no regs to dump, notice it through
5962 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5964 perf_output_put(handle
, abi
);
5967 u64 mask
= event
->attr
.sample_regs_user
;
5968 perf_output_sample_regs(handle
,
5969 data
->regs_user
.regs
,
5974 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5975 perf_output_sample_ustack(handle
,
5976 data
->stack_user_size
,
5977 data
->regs_user
.regs
);
5980 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5981 perf_output_put(handle
, data
->weight
);
5983 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5984 perf_output_put(handle
, data
->data_src
.val
);
5986 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5987 perf_output_put(handle
, data
->txn
);
5989 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5990 u64 abi
= data
->regs_intr
.abi
;
5992 * If there are no regs to dump, notice it through
5993 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5995 perf_output_put(handle
, abi
);
5998 u64 mask
= event
->attr
.sample_regs_intr
;
6000 perf_output_sample_regs(handle
,
6001 data
->regs_intr
.regs
,
6006 if (!event
->attr
.watermark
) {
6007 int wakeup_events
= event
->attr
.wakeup_events
;
6009 if (wakeup_events
) {
6010 struct ring_buffer
*rb
= handle
->rb
;
6011 int events
= local_inc_return(&rb
->events
);
6013 if (events
>= wakeup_events
) {
6014 local_sub(wakeup_events
, &rb
->events
);
6015 local_inc(&rb
->wakeup
);
6021 void perf_prepare_sample(struct perf_event_header
*header
,
6022 struct perf_sample_data
*data
,
6023 struct perf_event
*event
,
6024 struct pt_regs
*regs
)
6026 u64 sample_type
= event
->attr
.sample_type
;
6028 header
->type
= PERF_RECORD_SAMPLE
;
6029 header
->size
= sizeof(*header
) + event
->header_size
;
6032 header
->misc
|= perf_misc_flags(regs
);
6034 __perf_event_header__init_id(header
, data
, event
);
6036 if (sample_type
& PERF_SAMPLE_IP
)
6037 data
->ip
= perf_instruction_pointer(regs
);
6039 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6042 data
->callchain
= perf_callchain(event
, regs
);
6044 if (data
->callchain
)
6045 size
+= data
->callchain
->nr
;
6047 header
->size
+= size
* sizeof(u64
);
6050 if (sample_type
& PERF_SAMPLE_RAW
) {
6051 struct perf_raw_record
*raw
= data
->raw
;
6055 struct perf_raw_frag
*frag
= &raw
->frag
;
6060 if (perf_raw_frag_last(frag
))
6065 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6066 raw
->size
= size
- sizeof(u32
);
6067 frag
->pad
= raw
->size
- sum
;
6072 header
->size
+= size
;
6075 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6076 int size
= sizeof(u64
); /* nr */
6077 if (data
->br_stack
) {
6078 size
+= data
->br_stack
->nr
6079 * sizeof(struct perf_branch_entry
);
6081 header
->size
+= size
;
6084 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6085 perf_sample_regs_user(&data
->regs_user
, regs
,
6086 &data
->regs_user_copy
);
6088 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6089 /* regs dump ABI info */
6090 int size
= sizeof(u64
);
6092 if (data
->regs_user
.regs
) {
6093 u64 mask
= event
->attr
.sample_regs_user
;
6094 size
+= hweight64(mask
) * sizeof(u64
);
6097 header
->size
+= size
;
6100 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6102 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6103 * processed as the last one or have additional check added
6104 * in case new sample type is added, because we could eat
6105 * up the rest of the sample size.
6107 u16 stack_size
= event
->attr
.sample_stack_user
;
6108 u16 size
= sizeof(u64
);
6110 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6111 data
->regs_user
.regs
);
6114 * If there is something to dump, add space for the dump
6115 * itself and for the field that tells the dynamic size,
6116 * which is how many have been actually dumped.
6119 size
+= sizeof(u64
) + stack_size
;
6121 data
->stack_user_size
= stack_size
;
6122 header
->size
+= size
;
6125 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6126 /* regs dump ABI info */
6127 int size
= sizeof(u64
);
6129 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6131 if (data
->regs_intr
.regs
) {
6132 u64 mask
= event
->attr
.sample_regs_intr
;
6134 size
+= hweight64(mask
) * sizeof(u64
);
6137 header
->size
+= size
;
6141 static void __always_inline
6142 __perf_event_output(struct perf_event
*event
,
6143 struct perf_sample_data
*data
,
6144 struct pt_regs
*regs
,
6145 int (*output_begin
)(struct perf_output_handle
*,
6146 struct perf_event
*,
6149 struct perf_output_handle handle
;
6150 struct perf_event_header header
;
6152 /* protect the callchain buffers */
6155 perf_prepare_sample(&header
, data
, event
, regs
);
6157 if (output_begin(&handle
, event
, header
.size
))
6160 perf_output_sample(&handle
, &header
, data
, event
);
6162 perf_output_end(&handle
);
6169 perf_event_output_forward(struct perf_event
*event
,
6170 struct perf_sample_data
*data
,
6171 struct pt_regs
*regs
)
6173 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6177 perf_event_output_backward(struct perf_event
*event
,
6178 struct perf_sample_data
*data
,
6179 struct pt_regs
*regs
)
6181 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6185 perf_event_output(struct perf_event
*event
,
6186 struct perf_sample_data
*data
,
6187 struct pt_regs
*regs
)
6189 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6196 struct perf_read_event
{
6197 struct perf_event_header header
;
6204 perf_event_read_event(struct perf_event
*event
,
6205 struct task_struct
*task
)
6207 struct perf_output_handle handle
;
6208 struct perf_sample_data sample
;
6209 struct perf_read_event read_event
= {
6211 .type
= PERF_RECORD_READ
,
6213 .size
= sizeof(read_event
) + event
->read_size
,
6215 .pid
= perf_event_pid(event
, task
),
6216 .tid
= perf_event_tid(event
, task
),
6220 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6221 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6225 perf_output_put(&handle
, read_event
);
6226 perf_output_read(&handle
, event
);
6227 perf_event__output_id_sample(event
, &handle
, &sample
);
6229 perf_output_end(&handle
);
6232 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6235 perf_iterate_ctx(struct perf_event_context
*ctx
,
6236 perf_iterate_f output
,
6237 void *data
, bool all
)
6239 struct perf_event
*event
;
6241 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6243 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6245 if (!event_filter_match(event
))
6249 output(event
, data
);
6253 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6255 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6256 struct perf_event
*event
;
6258 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6260 * Skip events that are not fully formed yet; ensure that
6261 * if we observe event->ctx, both event and ctx will be
6262 * complete enough. See perf_install_in_context().
6264 if (!smp_load_acquire(&event
->ctx
))
6267 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6269 if (!event_filter_match(event
))
6271 output(event
, data
);
6276 * Iterate all events that need to receive side-band events.
6278 * For new callers; ensure that account_pmu_sb_event() includes
6279 * your event, otherwise it might not get delivered.
6282 perf_iterate_sb(perf_iterate_f output
, void *data
,
6283 struct perf_event_context
*task_ctx
)
6285 struct perf_event_context
*ctx
;
6292 * If we have task_ctx != NULL we only notify the task context itself.
6293 * The task_ctx is set only for EXIT events before releasing task
6297 perf_iterate_ctx(task_ctx
, output
, data
, false);
6301 perf_iterate_sb_cpu(output
, data
);
6303 for_each_task_context_nr(ctxn
) {
6304 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6306 perf_iterate_ctx(ctx
, output
, data
, false);
6314 * Clear all file-based filters at exec, they'll have to be
6315 * re-instated when/if these objects are mmapped again.
6317 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6319 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6320 struct perf_addr_filter
*filter
;
6321 unsigned int restart
= 0, count
= 0;
6322 unsigned long flags
;
6324 if (!has_addr_filter(event
))
6327 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6328 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6329 if (filter
->inode
) {
6330 event
->addr_filters_offs
[count
] = 0;
6338 event
->addr_filters_gen
++;
6339 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6342 perf_event_stop(event
, 1);
6345 void perf_event_exec(void)
6347 struct perf_event_context
*ctx
;
6351 for_each_task_context_nr(ctxn
) {
6352 ctx
= current
->perf_event_ctxp
[ctxn
];
6356 perf_event_enable_on_exec(ctxn
);
6358 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6364 struct remote_output
{
6365 struct ring_buffer
*rb
;
6369 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6371 struct perf_event
*parent
= event
->parent
;
6372 struct remote_output
*ro
= data
;
6373 struct ring_buffer
*rb
= ro
->rb
;
6374 struct stop_event_data sd
= {
6378 if (!has_aux(event
))
6385 * In case of inheritance, it will be the parent that links to the
6386 * ring-buffer, but it will be the child that's actually using it.
6388 * We are using event::rb to determine if the event should be stopped,
6389 * however this may race with ring_buffer_attach() (through set_output),
6390 * which will make us skip the event that actually needs to be stopped.
6391 * So ring_buffer_attach() has to stop an aux event before re-assigning
6394 if (rcu_dereference(parent
->rb
) == rb
)
6395 ro
->err
= __perf_event_stop(&sd
);
6398 static int __perf_pmu_output_stop(void *info
)
6400 struct perf_event
*event
= info
;
6401 struct pmu
*pmu
= event
->pmu
;
6402 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6403 struct remote_output ro
= {
6408 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6409 if (cpuctx
->task_ctx
)
6410 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6417 static void perf_pmu_output_stop(struct perf_event
*event
)
6419 struct perf_event
*iter
;
6424 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6426 * For per-CPU events, we need to make sure that neither they
6427 * nor their children are running; for cpu==-1 events it's
6428 * sufficient to stop the event itself if it's active, since
6429 * it can't have children.
6433 cpu
= READ_ONCE(iter
->oncpu
);
6438 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6439 if (err
== -EAGAIN
) {
6448 * task tracking -- fork/exit
6450 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6453 struct perf_task_event
{
6454 struct task_struct
*task
;
6455 struct perf_event_context
*task_ctx
;
6458 struct perf_event_header header
;
6468 static int perf_event_task_match(struct perf_event
*event
)
6470 return event
->attr
.comm
|| event
->attr
.mmap
||
6471 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6475 static void perf_event_task_output(struct perf_event
*event
,
6478 struct perf_task_event
*task_event
= data
;
6479 struct perf_output_handle handle
;
6480 struct perf_sample_data sample
;
6481 struct task_struct
*task
= task_event
->task
;
6482 int ret
, size
= task_event
->event_id
.header
.size
;
6484 if (!perf_event_task_match(event
))
6487 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6489 ret
= perf_output_begin(&handle
, event
,
6490 task_event
->event_id
.header
.size
);
6494 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6495 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6497 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6498 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6500 task_event
->event_id
.time
= perf_event_clock(event
);
6502 perf_output_put(&handle
, task_event
->event_id
);
6504 perf_event__output_id_sample(event
, &handle
, &sample
);
6506 perf_output_end(&handle
);
6508 task_event
->event_id
.header
.size
= size
;
6511 static void perf_event_task(struct task_struct
*task
,
6512 struct perf_event_context
*task_ctx
,
6515 struct perf_task_event task_event
;
6517 if (!atomic_read(&nr_comm_events
) &&
6518 !atomic_read(&nr_mmap_events
) &&
6519 !atomic_read(&nr_task_events
))
6522 task_event
= (struct perf_task_event
){
6524 .task_ctx
= task_ctx
,
6527 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6529 .size
= sizeof(task_event
.event_id
),
6539 perf_iterate_sb(perf_event_task_output
,
6544 void perf_event_fork(struct task_struct
*task
)
6546 perf_event_task(task
, NULL
, 1);
6547 perf_event_namespaces(task
);
6554 struct perf_comm_event
{
6555 struct task_struct
*task
;
6560 struct perf_event_header header
;
6567 static int perf_event_comm_match(struct perf_event
*event
)
6569 return event
->attr
.comm
;
6572 static void perf_event_comm_output(struct perf_event
*event
,
6575 struct perf_comm_event
*comm_event
= data
;
6576 struct perf_output_handle handle
;
6577 struct perf_sample_data sample
;
6578 int size
= comm_event
->event_id
.header
.size
;
6581 if (!perf_event_comm_match(event
))
6584 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6585 ret
= perf_output_begin(&handle
, event
,
6586 comm_event
->event_id
.header
.size
);
6591 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6592 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6594 perf_output_put(&handle
, comm_event
->event_id
);
6595 __output_copy(&handle
, comm_event
->comm
,
6596 comm_event
->comm_size
);
6598 perf_event__output_id_sample(event
, &handle
, &sample
);
6600 perf_output_end(&handle
);
6602 comm_event
->event_id
.header
.size
= size
;
6605 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6607 char comm
[TASK_COMM_LEN
];
6610 memset(comm
, 0, sizeof(comm
));
6611 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6612 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6614 comm_event
->comm
= comm
;
6615 comm_event
->comm_size
= size
;
6617 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6619 perf_iterate_sb(perf_event_comm_output
,
6624 void perf_event_comm(struct task_struct
*task
, bool exec
)
6626 struct perf_comm_event comm_event
;
6628 if (!atomic_read(&nr_comm_events
))
6631 comm_event
= (struct perf_comm_event
){
6637 .type
= PERF_RECORD_COMM
,
6638 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6646 perf_event_comm_event(&comm_event
);
6650 * namespaces tracking
6653 struct perf_namespaces_event
{
6654 struct task_struct
*task
;
6657 struct perf_event_header header
;
6662 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
6666 static int perf_event_namespaces_match(struct perf_event
*event
)
6668 return event
->attr
.namespaces
;
6671 static void perf_event_namespaces_output(struct perf_event
*event
,
6674 struct perf_namespaces_event
*namespaces_event
= data
;
6675 struct perf_output_handle handle
;
6676 struct perf_sample_data sample
;
6679 if (!perf_event_namespaces_match(event
))
6682 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
6684 ret
= perf_output_begin(&handle
, event
,
6685 namespaces_event
->event_id
.header
.size
);
6689 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
6690 namespaces_event
->task
);
6691 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
6692 namespaces_event
->task
);
6694 perf_output_put(&handle
, namespaces_event
->event_id
);
6696 perf_event__output_id_sample(event
, &handle
, &sample
);
6698 perf_output_end(&handle
);
6701 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
6702 struct task_struct
*task
,
6703 const struct proc_ns_operations
*ns_ops
)
6705 struct path ns_path
;
6706 struct inode
*ns_inode
;
6709 error
= ns_get_path(&ns_path
, task
, ns_ops
);
6711 ns_inode
= ns_path
.dentry
->d_inode
;
6712 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
6713 ns_link_info
->ino
= ns_inode
->i_ino
;
6717 void perf_event_namespaces(struct task_struct
*task
)
6719 struct perf_namespaces_event namespaces_event
;
6720 struct perf_ns_link_info
*ns_link_info
;
6722 if (!atomic_read(&nr_namespaces_events
))
6725 namespaces_event
= (struct perf_namespaces_event
){
6729 .type
= PERF_RECORD_NAMESPACES
,
6731 .size
= sizeof(namespaces_event
.event_id
),
6735 .nr_namespaces
= NR_NAMESPACES
,
6736 /* .link_info[NR_NAMESPACES] */
6740 ns_link_info
= namespaces_event
.event_id
.link_info
;
6742 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
6743 task
, &mntns_operations
);
6745 #ifdef CONFIG_USER_NS
6746 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
6747 task
, &userns_operations
);
6749 #ifdef CONFIG_NET_NS
6750 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
6751 task
, &netns_operations
);
6753 #ifdef CONFIG_UTS_NS
6754 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
6755 task
, &utsns_operations
);
6757 #ifdef CONFIG_IPC_NS
6758 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
6759 task
, &ipcns_operations
);
6761 #ifdef CONFIG_PID_NS
6762 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
6763 task
, &pidns_operations
);
6765 #ifdef CONFIG_CGROUPS
6766 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
6767 task
, &cgroupns_operations
);
6770 perf_iterate_sb(perf_event_namespaces_output
,
6779 struct perf_mmap_event
{
6780 struct vm_area_struct
*vma
;
6782 const char *file_name
;
6790 struct perf_event_header header
;
6800 static int perf_event_mmap_match(struct perf_event
*event
,
6803 struct perf_mmap_event
*mmap_event
= data
;
6804 struct vm_area_struct
*vma
= mmap_event
->vma
;
6805 int executable
= vma
->vm_flags
& VM_EXEC
;
6807 return (!executable
&& event
->attr
.mmap_data
) ||
6808 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6811 static void perf_event_mmap_output(struct perf_event
*event
,
6814 struct perf_mmap_event
*mmap_event
= data
;
6815 struct perf_output_handle handle
;
6816 struct perf_sample_data sample
;
6817 int size
= mmap_event
->event_id
.header
.size
;
6820 if (!perf_event_mmap_match(event
, data
))
6823 if (event
->attr
.mmap2
) {
6824 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6825 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6826 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6827 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6828 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6829 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6830 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6833 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6834 ret
= perf_output_begin(&handle
, event
,
6835 mmap_event
->event_id
.header
.size
);
6839 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6840 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6842 perf_output_put(&handle
, mmap_event
->event_id
);
6844 if (event
->attr
.mmap2
) {
6845 perf_output_put(&handle
, mmap_event
->maj
);
6846 perf_output_put(&handle
, mmap_event
->min
);
6847 perf_output_put(&handle
, mmap_event
->ino
);
6848 perf_output_put(&handle
, mmap_event
->ino_generation
);
6849 perf_output_put(&handle
, mmap_event
->prot
);
6850 perf_output_put(&handle
, mmap_event
->flags
);
6853 __output_copy(&handle
, mmap_event
->file_name
,
6854 mmap_event
->file_size
);
6856 perf_event__output_id_sample(event
, &handle
, &sample
);
6858 perf_output_end(&handle
);
6860 mmap_event
->event_id
.header
.size
= size
;
6863 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6865 struct vm_area_struct
*vma
= mmap_event
->vma
;
6866 struct file
*file
= vma
->vm_file
;
6867 int maj
= 0, min
= 0;
6868 u64 ino
= 0, gen
= 0;
6869 u32 prot
= 0, flags
= 0;
6875 if (vma
->vm_flags
& VM_READ
)
6877 if (vma
->vm_flags
& VM_WRITE
)
6879 if (vma
->vm_flags
& VM_EXEC
)
6882 if (vma
->vm_flags
& VM_MAYSHARE
)
6885 flags
= MAP_PRIVATE
;
6887 if (vma
->vm_flags
& VM_DENYWRITE
)
6888 flags
|= MAP_DENYWRITE
;
6889 if (vma
->vm_flags
& VM_MAYEXEC
)
6890 flags
|= MAP_EXECUTABLE
;
6891 if (vma
->vm_flags
& VM_LOCKED
)
6892 flags
|= MAP_LOCKED
;
6893 if (vma
->vm_flags
& VM_HUGETLB
)
6894 flags
|= MAP_HUGETLB
;
6897 struct inode
*inode
;
6900 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6906 * d_path() works from the end of the rb backwards, so we
6907 * need to add enough zero bytes after the string to handle
6908 * the 64bit alignment we do later.
6910 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6915 inode
= file_inode(vma
->vm_file
);
6916 dev
= inode
->i_sb
->s_dev
;
6918 gen
= inode
->i_generation
;
6924 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6925 name
= (char *) vma
->vm_ops
->name(vma
);
6930 name
= (char *)arch_vma_name(vma
);
6934 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6935 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6939 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6940 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6950 strlcpy(tmp
, name
, sizeof(tmp
));
6954 * Since our buffer works in 8 byte units we need to align our string
6955 * size to a multiple of 8. However, we must guarantee the tail end is
6956 * zero'd out to avoid leaking random bits to userspace.
6958 size
= strlen(name
)+1;
6959 while (!IS_ALIGNED(size
, sizeof(u64
)))
6960 name
[size
++] = '\0';
6962 mmap_event
->file_name
= name
;
6963 mmap_event
->file_size
= size
;
6964 mmap_event
->maj
= maj
;
6965 mmap_event
->min
= min
;
6966 mmap_event
->ino
= ino
;
6967 mmap_event
->ino_generation
= gen
;
6968 mmap_event
->prot
= prot
;
6969 mmap_event
->flags
= flags
;
6971 if (!(vma
->vm_flags
& VM_EXEC
))
6972 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6974 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6976 perf_iterate_sb(perf_event_mmap_output
,
6984 * Check whether inode and address range match filter criteria.
6986 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
6987 struct file
*file
, unsigned long offset
,
6990 if (filter
->inode
!= file_inode(file
))
6993 if (filter
->offset
> offset
+ size
)
6996 if (filter
->offset
+ filter
->size
< offset
)
7002 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
7004 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
7005 struct vm_area_struct
*vma
= data
;
7006 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
7007 struct file
*file
= vma
->vm_file
;
7008 struct perf_addr_filter
*filter
;
7009 unsigned int restart
= 0, count
= 0;
7011 if (!has_addr_filter(event
))
7017 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
7018 list_for_each_entry(filter
, &ifh
->list
, entry
) {
7019 if (perf_addr_filter_match(filter
, file
, off
,
7020 vma
->vm_end
- vma
->vm_start
)) {
7021 event
->addr_filters_offs
[count
] = vma
->vm_start
;
7029 event
->addr_filters_gen
++;
7030 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
7033 perf_event_stop(event
, 1);
7037 * Adjust all task's events' filters to the new vma
7039 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
7041 struct perf_event_context
*ctx
;
7045 * Data tracing isn't supported yet and as such there is no need
7046 * to keep track of anything that isn't related to executable code:
7048 if (!(vma
->vm_flags
& VM_EXEC
))
7052 for_each_task_context_nr(ctxn
) {
7053 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7057 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7062 void perf_event_mmap(struct vm_area_struct
*vma
)
7064 struct perf_mmap_event mmap_event
;
7066 if (!atomic_read(&nr_mmap_events
))
7069 mmap_event
= (struct perf_mmap_event
){
7075 .type
= PERF_RECORD_MMAP
,
7076 .misc
= PERF_RECORD_MISC_USER
,
7081 .start
= vma
->vm_start
,
7082 .len
= vma
->vm_end
- vma
->vm_start
,
7083 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7085 /* .maj (attr_mmap2 only) */
7086 /* .min (attr_mmap2 only) */
7087 /* .ino (attr_mmap2 only) */
7088 /* .ino_generation (attr_mmap2 only) */
7089 /* .prot (attr_mmap2 only) */
7090 /* .flags (attr_mmap2 only) */
7093 perf_addr_filters_adjust(vma
);
7094 perf_event_mmap_event(&mmap_event
);
7097 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7098 unsigned long size
, u64 flags
)
7100 struct perf_output_handle handle
;
7101 struct perf_sample_data sample
;
7102 struct perf_aux_event
{
7103 struct perf_event_header header
;
7109 .type
= PERF_RECORD_AUX
,
7111 .size
= sizeof(rec
),
7119 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7120 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7125 perf_output_put(&handle
, rec
);
7126 perf_event__output_id_sample(event
, &handle
, &sample
);
7128 perf_output_end(&handle
);
7132 * Lost/dropped samples logging
7134 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7136 struct perf_output_handle handle
;
7137 struct perf_sample_data sample
;
7141 struct perf_event_header header
;
7143 } lost_samples_event
= {
7145 .type
= PERF_RECORD_LOST_SAMPLES
,
7147 .size
= sizeof(lost_samples_event
),
7152 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7154 ret
= perf_output_begin(&handle
, event
,
7155 lost_samples_event
.header
.size
);
7159 perf_output_put(&handle
, lost_samples_event
);
7160 perf_event__output_id_sample(event
, &handle
, &sample
);
7161 perf_output_end(&handle
);
7165 * context_switch tracking
7168 struct perf_switch_event
{
7169 struct task_struct
*task
;
7170 struct task_struct
*next_prev
;
7173 struct perf_event_header header
;
7179 static int perf_event_switch_match(struct perf_event
*event
)
7181 return event
->attr
.context_switch
;
7184 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7186 struct perf_switch_event
*se
= data
;
7187 struct perf_output_handle handle
;
7188 struct perf_sample_data sample
;
7191 if (!perf_event_switch_match(event
))
7194 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7195 if (event
->ctx
->task
) {
7196 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7197 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7199 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7200 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7201 se
->event_id
.next_prev_pid
=
7202 perf_event_pid(event
, se
->next_prev
);
7203 se
->event_id
.next_prev_tid
=
7204 perf_event_tid(event
, se
->next_prev
);
7207 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7209 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7213 if (event
->ctx
->task
)
7214 perf_output_put(&handle
, se
->event_id
.header
);
7216 perf_output_put(&handle
, se
->event_id
);
7218 perf_event__output_id_sample(event
, &handle
, &sample
);
7220 perf_output_end(&handle
);
7223 static void perf_event_switch(struct task_struct
*task
,
7224 struct task_struct
*next_prev
, bool sched_in
)
7226 struct perf_switch_event switch_event
;
7228 /* N.B. caller checks nr_switch_events != 0 */
7230 switch_event
= (struct perf_switch_event
){
7232 .next_prev
= next_prev
,
7236 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7239 /* .next_prev_pid */
7240 /* .next_prev_tid */
7244 perf_iterate_sb(perf_event_switch_output
,
7250 * IRQ throttle logging
7253 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7255 struct perf_output_handle handle
;
7256 struct perf_sample_data sample
;
7260 struct perf_event_header header
;
7264 } throttle_event
= {
7266 .type
= PERF_RECORD_THROTTLE
,
7268 .size
= sizeof(throttle_event
),
7270 .time
= perf_event_clock(event
),
7271 .id
= primary_event_id(event
),
7272 .stream_id
= event
->id
,
7276 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7278 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7280 ret
= perf_output_begin(&handle
, event
,
7281 throttle_event
.header
.size
);
7285 perf_output_put(&handle
, throttle_event
);
7286 perf_event__output_id_sample(event
, &handle
, &sample
);
7287 perf_output_end(&handle
);
7290 static void perf_log_itrace_start(struct perf_event
*event
)
7292 struct perf_output_handle handle
;
7293 struct perf_sample_data sample
;
7294 struct perf_aux_event
{
7295 struct perf_event_header header
;
7302 event
= event
->parent
;
7304 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7305 event
->hw
.itrace_started
)
7308 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7309 rec
.header
.misc
= 0;
7310 rec
.header
.size
= sizeof(rec
);
7311 rec
.pid
= perf_event_pid(event
, current
);
7312 rec
.tid
= perf_event_tid(event
, current
);
7314 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7315 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7320 perf_output_put(&handle
, rec
);
7321 perf_event__output_id_sample(event
, &handle
, &sample
);
7323 perf_output_end(&handle
);
7327 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7329 struct hw_perf_event
*hwc
= &event
->hw
;
7333 seq
= __this_cpu_read(perf_throttled_seq
);
7334 if (seq
!= hwc
->interrupts_seq
) {
7335 hwc
->interrupts_seq
= seq
;
7336 hwc
->interrupts
= 1;
7339 if (unlikely(throttle
7340 && hwc
->interrupts
>= max_samples_per_tick
)) {
7341 __this_cpu_inc(perf_throttled_count
);
7342 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7343 hwc
->interrupts
= MAX_INTERRUPTS
;
7344 perf_log_throttle(event
, 0);
7349 if (event
->attr
.freq
) {
7350 u64 now
= perf_clock();
7351 s64 delta
= now
- hwc
->freq_time_stamp
;
7353 hwc
->freq_time_stamp
= now
;
7355 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7356 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7362 int perf_event_account_interrupt(struct perf_event
*event
)
7364 return __perf_event_account_interrupt(event
, 1);
7368 * Generic event overflow handling, sampling.
7371 static int __perf_event_overflow(struct perf_event
*event
,
7372 int throttle
, struct perf_sample_data
*data
,
7373 struct pt_regs
*regs
)
7375 int events
= atomic_read(&event
->event_limit
);
7379 * Non-sampling counters might still use the PMI to fold short
7380 * hardware counters, ignore those.
7382 if (unlikely(!is_sampling_event(event
)))
7385 ret
= __perf_event_account_interrupt(event
, throttle
);
7388 * XXX event_limit might not quite work as expected on inherited
7392 event
->pending_kill
= POLL_IN
;
7393 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7395 event
->pending_kill
= POLL_HUP
;
7397 perf_event_disable_inatomic(event
);
7400 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7402 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7403 event
->pending_wakeup
= 1;
7404 irq_work_queue(&event
->pending
);
7410 int perf_event_overflow(struct perf_event
*event
,
7411 struct perf_sample_data
*data
,
7412 struct pt_regs
*regs
)
7414 return __perf_event_overflow(event
, 1, data
, regs
);
7418 * Generic software event infrastructure
7421 struct swevent_htable
{
7422 struct swevent_hlist
*swevent_hlist
;
7423 struct mutex hlist_mutex
;
7426 /* Recursion avoidance in each contexts */
7427 int recursion
[PERF_NR_CONTEXTS
];
7430 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7433 * We directly increment event->count and keep a second value in
7434 * event->hw.period_left to count intervals. This period event
7435 * is kept in the range [-sample_period, 0] so that we can use the
7439 u64
perf_swevent_set_period(struct perf_event
*event
)
7441 struct hw_perf_event
*hwc
= &event
->hw
;
7442 u64 period
= hwc
->last_period
;
7446 hwc
->last_period
= hwc
->sample_period
;
7449 old
= val
= local64_read(&hwc
->period_left
);
7453 nr
= div64_u64(period
+ val
, period
);
7454 offset
= nr
* period
;
7456 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7462 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7463 struct perf_sample_data
*data
,
7464 struct pt_regs
*regs
)
7466 struct hw_perf_event
*hwc
= &event
->hw
;
7470 overflow
= perf_swevent_set_period(event
);
7472 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7475 for (; overflow
; overflow
--) {
7476 if (__perf_event_overflow(event
, throttle
,
7479 * We inhibit the overflow from happening when
7480 * hwc->interrupts == MAX_INTERRUPTS.
7488 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7489 struct perf_sample_data
*data
,
7490 struct pt_regs
*regs
)
7492 struct hw_perf_event
*hwc
= &event
->hw
;
7494 local64_add(nr
, &event
->count
);
7499 if (!is_sampling_event(event
))
7502 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7504 return perf_swevent_overflow(event
, 1, data
, regs
);
7506 data
->period
= event
->hw
.last_period
;
7508 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7509 return perf_swevent_overflow(event
, 1, data
, regs
);
7511 if (local64_add_negative(nr
, &hwc
->period_left
))
7514 perf_swevent_overflow(event
, 0, data
, regs
);
7517 static int perf_exclude_event(struct perf_event
*event
,
7518 struct pt_regs
*regs
)
7520 if (event
->hw
.state
& PERF_HES_STOPPED
)
7524 if (event
->attr
.exclude_user
&& user_mode(regs
))
7527 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7534 static int perf_swevent_match(struct perf_event
*event
,
7535 enum perf_type_id type
,
7537 struct perf_sample_data
*data
,
7538 struct pt_regs
*regs
)
7540 if (event
->attr
.type
!= type
)
7543 if (event
->attr
.config
!= event_id
)
7546 if (perf_exclude_event(event
, regs
))
7552 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7554 u64 val
= event_id
| (type
<< 32);
7556 return hash_64(val
, SWEVENT_HLIST_BITS
);
7559 static inline struct hlist_head
*
7560 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7562 u64 hash
= swevent_hash(type
, event_id
);
7564 return &hlist
->heads
[hash
];
7567 /* For the read side: events when they trigger */
7568 static inline struct hlist_head
*
7569 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7571 struct swevent_hlist
*hlist
;
7573 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7577 return __find_swevent_head(hlist
, type
, event_id
);
7580 /* For the event head insertion and removal in the hlist */
7581 static inline struct hlist_head
*
7582 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7584 struct swevent_hlist
*hlist
;
7585 u32 event_id
= event
->attr
.config
;
7586 u64 type
= event
->attr
.type
;
7589 * Event scheduling is always serialized against hlist allocation
7590 * and release. Which makes the protected version suitable here.
7591 * The context lock guarantees that.
7593 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7594 lockdep_is_held(&event
->ctx
->lock
));
7598 return __find_swevent_head(hlist
, type
, event_id
);
7601 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7603 struct perf_sample_data
*data
,
7604 struct pt_regs
*regs
)
7606 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7607 struct perf_event
*event
;
7608 struct hlist_head
*head
;
7611 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7615 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7616 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7617 perf_swevent_event(event
, nr
, data
, regs
);
7623 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7625 int perf_swevent_get_recursion_context(void)
7627 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7629 return get_recursion_context(swhash
->recursion
);
7631 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7633 void perf_swevent_put_recursion_context(int rctx
)
7635 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7637 put_recursion_context(swhash
->recursion
, rctx
);
7640 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7642 struct perf_sample_data data
;
7644 if (WARN_ON_ONCE(!regs
))
7647 perf_sample_data_init(&data
, addr
, 0);
7648 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7651 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7655 preempt_disable_notrace();
7656 rctx
= perf_swevent_get_recursion_context();
7657 if (unlikely(rctx
< 0))
7660 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7662 perf_swevent_put_recursion_context(rctx
);
7664 preempt_enable_notrace();
7667 static void perf_swevent_read(struct perf_event
*event
)
7671 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7673 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7674 struct hw_perf_event
*hwc
= &event
->hw
;
7675 struct hlist_head
*head
;
7677 if (is_sampling_event(event
)) {
7678 hwc
->last_period
= hwc
->sample_period
;
7679 perf_swevent_set_period(event
);
7682 hwc
->state
= !(flags
& PERF_EF_START
);
7684 head
= find_swevent_head(swhash
, event
);
7685 if (WARN_ON_ONCE(!head
))
7688 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7689 perf_event_update_userpage(event
);
7694 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7696 hlist_del_rcu(&event
->hlist_entry
);
7699 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7701 event
->hw
.state
= 0;
7704 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7706 event
->hw
.state
= PERF_HES_STOPPED
;
7709 /* Deref the hlist from the update side */
7710 static inline struct swevent_hlist
*
7711 swevent_hlist_deref(struct swevent_htable
*swhash
)
7713 return rcu_dereference_protected(swhash
->swevent_hlist
,
7714 lockdep_is_held(&swhash
->hlist_mutex
));
7717 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7719 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7724 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7725 kfree_rcu(hlist
, rcu_head
);
7728 static void swevent_hlist_put_cpu(int cpu
)
7730 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7732 mutex_lock(&swhash
->hlist_mutex
);
7734 if (!--swhash
->hlist_refcount
)
7735 swevent_hlist_release(swhash
);
7737 mutex_unlock(&swhash
->hlist_mutex
);
7740 static void swevent_hlist_put(void)
7744 for_each_possible_cpu(cpu
)
7745 swevent_hlist_put_cpu(cpu
);
7748 static int swevent_hlist_get_cpu(int cpu
)
7750 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7753 mutex_lock(&swhash
->hlist_mutex
);
7754 if (!swevent_hlist_deref(swhash
) &&
7755 cpumask_test_cpu(cpu
, perf_online_mask
)) {
7756 struct swevent_hlist
*hlist
;
7758 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7763 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7765 swhash
->hlist_refcount
++;
7767 mutex_unlock(&swhash
->hlist_mutex
);
7772 static int swevent_hlist_get(void)
7774 int err
, cpu
, failed_cpu
;
7776 mutex_lock(&pmus_lock
);
7777 for_each_possible_cpu(cpu
) {
7778 err
= swevent_hlist_get_cpu(cpu
);
7784 mutex_unlock(&pmus_lock
);
7787 for_each_possible_cpu(cpu
) {
7788 if (cpu
== failed_cpu
)
7790 swevent_hlist_put_cpu(cpu
);
7792 mutex_unlock(&pmus_lock
);
7796 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7798 static void sw_perf_event_destroy(struct perf_event
*event
)
7800 u64 event_id
= event
->attr
.config
;
7802 WARN_ON(event
->parent
);
7804 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7805 swevent_hlist_put();
7808 static int perf_swevent_init(struct perf_event
*event
)
7810 u64 event_id
= event
->attr
.config
;
7812 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7816 * no branch sampling for software events
7818 if (has_branch_stack(event
))
7822 case PERF_COUNT_SW_CPU_CLOCK
:
7823 case PERF_COUNT_SW_TASK_CLOCK
:
7830 if (event_id
>= PERF_COUNT_SW_MAX
)
7833 if (!event
->parent
) {
7836 err
= swevent_hlist_get();
7840 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7841 event
->destroy
= sw_perf_event_destroy
;
7847 static struct pmu perf_swevent
= {
7848 .task_ctx_nr
= perf_sw_context
,
7850 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7852 .event_init
= perf_swevent_init
,
7853 .add
= perf_swevent_add
,
7854 .del
= perf_swevent_del
,
7855 .start
= perf_swevent_start
,
7856 .stop
= perf_swevent_stop
,
7857 .read
= perf_swevent_read
,
7860 #ifdef CONFIG_EVENT_TRACING
7862 static int perf_tp_filter_match(struct perf_event
*event
,
7863 struct perf_sample_data
*data
)
7865 void *record
= data
->raw
->frag
.data
;
7867 /* only top level events have filters set */
7869 event
= event
->parent
;
7871 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7876 static int perf_tp_event_match(struct perf_event
*event
,
7877 struct perf_sample_data
*data
,
7878 struct pt_regs
*regs
)
7880 if (event
->hw
.state
& PERF_HES_STOPPED
)
7883 * All tracepoints are from kernel-space.
7885 if (event
->attr
.exclude_kernel
)
7888 if (!perf_tp_filter_match(event
, data
))
7894 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7895 struct trace_event_call
*call
, u64 count
,
7896 struct pt_regs
*regs
, struct hlist_head
*head
,
7897 struct task_struct
*task
)
7899 struct bpf_prog
*prog
= call
->prog
;
7902 *(struct pt_regs
**)raw_data
= regs
;
7903 if (!trace_call_bpf(prog
, raw_data
) || hlist_empty(head
)) {
7904 perf_swevent_put_recursion_context(rctx
);
7908 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7911 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7913 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7914 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7915 struct task_struct
*task
)
7917 struct perf_sample_data data
;
7918 struct perf_event
*event
;
7920 struct perf_raw_record raw
= {
7927 perf_sample_data_init(&data
, 0, 0);
7930 perf_trace_buf_update(record
, event_type
);
7932 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7933 if (perf_tp_event_match(event
, &data
, regs
))
7934 perf_swevent_event(event
, count
, &data
, regs
);
7938 * If we got specified a target task, also iterate its context and
7939 * deliver this event there too.
7941 if (task
&& task
!= current
) {
7942 struct perf_event_context
*ctx
;
7943 struct trace_entry
*entry
= record
;
7946 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7950 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7951 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7953 if (event
->attr
.config
!= entry
->type
)
7955 if (perf_tp_event_match(event
, &data
, regs
))
7956 perf_swevent_event(event
, count
, &data
, regs
);
7962 perf_swevent_put_recursion_context(rctx
);
7964 EXPORT_SYMBOL_GPL(perf_tp_event
);
7966 static void tp_perf_event_destroy(struct perf_event
*event
)
7968 perf_trace_destroy(event
);
7971 static int perf_tp_event_init(struct perf_event
*event
)
7975 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7979 * no branch sampling for tracepoint events
7981 if (has_branch_stack(event
))
7984 err
= perf_trace_init(event
);
7988 event
->destroy
= tp_perf_event_destroy
;
7993 static struct pmu perf_tracepoint
= {
7994 .task_ctx_nr
= perf_sw_context
,
7996 .event_init
= perf_tp_event_init
,
7997 .add
= perf_trace_add
,
7998 .del
= perf_trace_del
,
7999 .start
= perf_swevent_start
,
8000 .stop
= perf_swevent_stop
,
8001 .read
= perf_swevent_read
,
8004 static inline void perf_tp_register(void)
8006 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
8009 static void perf_event_free_filter(struct perf_event
*event
)
8011 ftrace_profile_free_filter(event
);
8014 #ifdef CONFIG_BPF_SYSCALL
8015 static void bpf_overflow_handler(struct perf_event
*event
,
8016 struct perf_sample_data
*data
,
8017 struct pt_regs
*regs
)
8019 struct bpf_perf_event_data_kern ctx
= {
8026 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
8029 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
8032 __this_cpu_dec(bpf_prog_active
);
8037 event
->orig_overflow_handler(event
, data
, regs
);
8040 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8042 struct bpf_prog
*prog
;
8044 if (event
->overflow_handler_context
)
8045 /* hw breakpoint or kernel counter */
8051 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8053 return PTR_ERR(prog
);
8056 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8057 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8061 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8063 struct bpf_prog
*prog
= event
->prog
;
8068 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
8073 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8077 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8082 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8084 bool is_kprobe
, is_tracepoint
, is_syscall_tp
;
8085 struct bpf_prog
*prog
;
8087 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8088 return perf_event_set_bpf_handler(event
, prog_fd
);
8090 if (event
->tp_event
->prog
)
8093 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
8094 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
8095 is_syscall_tp
= is_syscall_trace_event(event
->tp_event
);
8096 if (!is_kprobe
&& !is_tracepoint
&& !is_syscall_tp
)
8097 /* bpf programs can only be attached to u/kprobe or tracepoint */
8100 prog
= bpf_prog_get(prog_fd
);
8102 return PTR_ERR(prog
);
8104 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
8105 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
) ||
8106 (is_syscall_tp
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
8107 /* valid fd, but invalid bpf program type */
8112 if (is_tracepoint
|| is_syscall_tp
) {
8113 int off
= trace_event_get_offsets(event
->tp_event
);
8115 if (prog
->aux
->max_ctx_offset
> off
) {
8120 event
->tp_event
->prog
= prog
;
8125 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8127 struct bpf_prog
*prog
;
8129 perf_event_free_bpf_handler(event
);
8131 if (!event
->tp_event
)
8134 prog
= event
->tp_event
->prog
;
8136 event
->tp_event
->prog
= NULL
;
8143 static inline void perf_tp_register(void)
8147 static void perf_event_free_filter(struct perf_event
*event
)
8151 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8156 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8159 #endif /* CONFIG_EVENT_TRACING */
8161 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8162 void perf_bp_event(struct perf_event
*bp
, void *data
)
8164 struct perf_sample_data sample
;
8165 struct pt_regs
*regs
= data
;
8167 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
8169 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
8170 perf_swevent_event(bp
, 1, &sample
, regs
);
8175 * Allocate a new address filter
8177 static struct perf_addr_filter
*
8178 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
8180 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8181 struct perf_addr_filter
*filter
;
8183 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8187 INIT_LIST_HEAD(&filter
->entry
);
8188 list_add_tail(&filter
->entry
, filters
);
8193 static void free_filters_list(struct list_head
*filters
)
8195 struct perf_addr_filter
*filter
, *iter
;
8197 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8199 iput(filter
->inode
);
8200 list_del(&filter
->entry
);
8206 * Free existing address filters and optionally install new ones
8208 static void perf_addr_filters_splice(struct perf_event
*event
,
8209 struct list_head
*head
)
8211 unsigned long flags
;
8214 if (!has_addr_filter(event
))
8217 /* don't bother with children, they don't have their own filters */
8221 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8223 list_splice_init(&event
->addr_filters
.list
, &list
);
8225 list_splice(head
, &event
->addr_filters
.list
);
8227 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8229 free_filters_list(&list
);
8233 * Scan through mm's vmas and see if one of them matches the
8234 * @filter; if so, adjust filter's address range.
8235 * Called with mm::mmap_sem down for reading.
8237 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8238 struct mm_struct
*mm
)
8240 struct vm_area_struct
*vma
;
8242 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8243 struct file
*file
= vma
->vm_file
;
8244 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8245 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8250 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8253 return vma
->vm_start
;
8260 * Update event's address range filters based on the
8261 * task's existing mappings, if any.
8263 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8265 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8266 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8267 struct perf_addr_filter
*filter
;
8268 struct mm_struct
*mm
= NULL
;
8269 unsigned int count
= 0;
8270 unsigned long flags
;
8273 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8274 * will stop on the parent's child_mutex that our caller is also holding
8276 if (task
== TASK_TOMBSTONE
)
8279 if (!ifh
->nr_file_filters
)
8282 mm
= get_task_mm(event
->ctx
->task
);
8286 down_read(&mm
->mmap_sem
);
8288 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8289 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8290 event
->addr_filters_offs
[count
] = 0;
8293 * Adjust base offset if the filter is associated to a binary
8294 * that needs to be mapped:
8297 event
->addr_filters_offs
[count
] =
8298 perf_addr_filter_apply(filter
, mm
);
8303 event
->addr_filters_gen
++;
8304 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8306 up_read(&mm
->mmap_sem
);
8311 perf_event_stop(event
, 1);
8315 * Address range filtering: limiting the data to certain
8316 * instruction address ranges. Filters are ioctl()ed to us from
8317 * userspace as ascii strings.
8319 * Filter string format:
8322 * where ACTION is one of the
8323 * * "filter": limit the trace to this region
8324 * * "start": start tracing from this address
8325 * * "stop": stop tracing at this address/region;
8327 * * for kernel addresses: <start address>[/<size>]
8328 * * for object files: <start address>[/<size>]@</path/to/object/file>
8330 * if <size> is not specified, the range is treated as a single address.
8344 IF_STATE_ACTION
= 0,
8349 static const match_table_t if_tokens
= {
8350 { IF_ACT_FILTER
, "filter" },
8351 { IF_ACT_START
, "start" },
8352 { IF_ACT_STOP
, "stop" },
8353 { IF_SRC_FILE
, "%u/%u@%s" },
8354 { IF_SRC_KERNEL
, "%u/%u" },
8355 { IF_SRC_FILEADDR
, "%u@%s" },
8356 { IF_SRC_KERNELADDR
, "%u" },
8357 { IF_ACT_NONE
, NULL
},
8361 * Address filter string parser
8364 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8365 struct list_head
*filters
)
8367 struct perf_addr_filter
*filter
= NULL
;
8368 char *start
, *orig
, *filename
= NULL
;
8370 substring_t args
[MAX_OPT_ARGS
];
8371 int state
= IF_STATE_ACTION
, token
;
8372 unsigned int kernel
= 0;
8375 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8379 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8385 /* filter definition begins */
8386 if (state
== IF_STATE_ACTION
) {
8387 filter
= perf_addr_filter_new(event
, filters
);
8392 token
= match_token(start
, if_tokens
, args
);
8399 if (state
!= IF_STATE_ACTION
)
8402 state
= IF_STATE_SOURCE
;
8405 case IF_SRC_KERNELADDR
:
8409 case IF_SRC_FILEADDR
:
8411 if (state
!= IF_STATE_SOURCE
)
8414 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8418 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8422 if (filter
->range
) {
8424 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8429 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8430 int fpos
= filter
->range
? 2 : 1;
8432 filename
= match_strdup(&args
[fpos
]);
8439 state
= IF_STATE_END
;
8447 * Filter definition is fully parsed, validate and install it.
8448 * Make sure that it doesn't contradict itself or the event's
8451 if (state
== IF_STATE_END
) {
8453 if (kernel
&& event
->attr
.exclude_kernel
)
8461 * For now, we only support file-based filters
8462 * in per-task events; doing so for CPU-wide
8463 * events requires additional context switching
8464 * trickery, since same object code will be
8465 * mapped at different virtual addresses in
8466 * different processes.
8469 if (!event
->ctx
->task
)
8470 goto fail_free_name
;
8472 /* look up the path and grab its inode */
8473 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8475 goto fail_free_name
;
8477 filter
->inode
= igrab(d_inode(path
.dentry
));
8483 if (!filter
->inode
||
8484 !S_ISREG(filter
->inode
->i_mode
))
8485 /* free_filters_list() will iput() */
8488 event
->addr_filters
.nr_file_filters
++;
8491 /* ready to consume more filters */
8492 state
= IF_STATE_ACTION
;
8497 if (state
!= IF_STATE_ACTION
)
8507 free_filters_list(filters
);
8514 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8520 * Since this is called in perf_ioctl() path, we're already holding
8523 lockdep_assert_held(&event
->ctx
->mutex
);
8525 if (WARN_ON_ONCE(event
->parent
))
8528 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8530 goto fail_clear_files
;
8532 ret
= event
->pmu
->addr_filters_validate(&filters
);
8534 goto fail_free_filters
;
8536 /* remove existing filters, if any */
8537 perf_addr_filters_splice(event
, &filters
);
8539 /* install new filters */
8540 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8545 free_filters_list(&filters
);
8548 event
->addr_filters
.nr_file_filters
= 0;
8553 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8558 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8559 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8560 !has_addr_filter(event
))
8563 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8564 if (IS_ERR(filter_str
))
8565 return PTR_ERR(filter_str
);
8567 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8568 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8569 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
8571 else if (has_addr_filter(event
))
8572 ret
= perf_event_set_addr_filter(event
, filter_str
);
8579 * hrtimer based swevent callback
8582 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8584 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8585 struct perf_sample_data data
;
8586 struct pt_regs
*regs
;
8587 struct perf_event
*event
;
8590 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8592 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8593 return HRTIMER_NORESTART
;
8595 event
->pmu
->read(event
);
8597 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8598 regs
= get_irq_regs();
8600 if (regs
&& !perf_exclude_event(event
, regs
)) {
8601 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8602 if (__perf_event_overflow(event
, 1, &data
, regs
))
8603 ret
= HRTIMER_NORESTART
;
8606 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8607 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8612 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8614 struct hw_perf_event
*hwc
= &event
->hw
;
8617 if (!is_sampling_event(event
))
8620 period
= local64_read(&hwc
->period_left
);
8625 local64_set(&hwc
->period_left
, 0);
8627 period
= max_t(u64
, 10000, hwc
->sample_period
);
8629 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8630 HRTIMER_MODE_REL_PINNED
);
8633 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8635 struct hw_perf_event
*hwc
= &event
->hw
;
8637 if (is_sampling_event(event
)) {
8638 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8639 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8641 hrtimer_cancel(&hwc
->hrtimer
);
8645 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8647 struct hw_perf_event
*hwc
= &event
->hw
;
8649 if (!is_sampling_event(event
))
8652 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8653 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8656 * Since hrtimers have a fixed rate, we can do a static freq->period
8657 * mapping and avoid the whole period adjust feedback stuff.
8659 if (event
->attr
.freq
) {
8660 long freq
= event
->attr
.sample_freq
;
8662 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8663 hwc
->sample_period
= event
->attr
.sample_period
;
8664 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8665 hwc
->last_period
= hwc
->sample_period
;
8666 event
->attr
.freq
= 0;
8671 * Software event: cpu wall time clock
8674 static void cpu_clock_event_update(struct perf_event
*event
)
8679 now
= local_clock();
8680 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8681 local64_add(now
- prev
, &event
->count
);
8684 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8686 local64_set(&event
->hw
.prev_count
, local_clock());
8687 perf_swevent_start_hrtimer(event
);
8690 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8692 perf_swevent_cancel_hrtimer(event
);
8693 cpu_clock_event_update(event
);
8696 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8698 if (flags
& PERF_EF_START
)
8699 cpu_clock_event_start(event
, flags
);
8700 perf_event_update_userpage(event
);
8705 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8707 cpu_clock_event_stop(event
, flags
);
8710 static void cpu_clock_event_read(struct perf_event
*event
)
8712 cpu_clock_event_update(event
);
8715 static int cpu_clock_event_init(struct perf_event
*event
)
8717 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8720 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8724 * no branch sampling for software events
8726 if (has_branch_stack(event
))
8729 perf_swevent_init_hrtimer(event
);
8734 static struct pmu perf_cpu_clock
= {
8735 .task_ctx_nr
= perf_sw_context
,
8737 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8739 .event_init
= cpu_clock_event_init
,
8740 .add
= cpu_clock_event_add
,
8741 .del
= cpu_clock_event_del
,
8742 .start
= cpu_clock_event_start
,
8743 .stop
= cpu_clock_event_stop
,
8744 .read
= cpu_clock_event_read
,
8748 * Software event: task time clock
8751 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8756 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8758 local64_add(delta
, &event
->count
);
8761 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8763 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8764 perf_swevent_start_hrtimer(event
);
8767 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8769 perf_swevent_cancel_hrtimer(event
);
8770 task_clock_event_update(event
, event
->ctx
->time
);
8773 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8775 if (flags
& PERF_EF_START
)
8776 task_clock_event_start(event
, flags
);
8777 perf_event_update_userpage(event
);
8782 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8784 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8787 static void task_clock_event_read(struct perf_event
*event
)
8789 u64 now
= perf_clock();
8790 u64 delta
= now
- event
->ctx
->timestamp
;
8791 u64 time
= event
->ctx
->time
+ delta
;
8793 task_clock_event_update(event
, time
);
8796 static int task_clock_event_init(struct perf_event
*event
)
8798 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8801 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8805 * no branch sampling for software events
8807 if (has_branch_stack(event
))
8810 perf_swevent_init_hrtimer(event
);
8815 static struct pmu perf_task_clock
= {
8816 .task_ctx_nr
= perf_sw_context
,
8818 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8820 .event_init
= task_clock_event_init
,
8821 .add
= task_clock_event_add
,
8822 .del
= task_clock_event_del
,
8823 .start
= task_clock_event_start
,
8824 .stop
= task_clock_event_stop
,
8825 .read
= task_clock_event_read
,
8828 static void perf_pmu_nop_void(struct pmu
*pmu
)
8832 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8836 static int perf_pmu_nop_int(struct pmu
*pmu
)
8841 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8843 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8845 __this_cpu_write(nop_txn_flags
, flags
);
8847 if (flags
& ~PERF_PMU_TXN_ADD
)
8850 perf_pmu_disable(pmu
);
8853 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8855 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8857 __this_cpu_write(nop_txn_flags
, 0);
8859 if (flags
& ~PERF_PMU_TXN_ADD
)
8862 perf_pmu_enable(pmu
);
8866 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8868 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8870 __this_cpu_write(nop_txn_flags
, 0);
8872 if (flags
& ~PERF_PMU_TXN_ADD
)
8875 perf_pmu_enable(pmu
);
8878 static int perf_event_idx_default(struct perf_event
*event
)
8884 * Ensures all contexts with the same task_ctx_nr have the same
8885 * pmu_cpu_context too.
8887 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8894 list_for_each_entry(pmu
, &pmus
, entry
) {
8895 if (pmu
->task_ctx_nr
== ctxn
)
8896 return pmu
->pmu_cpu_context
;
8902 static void free_pmu_context(struct pmu
*pmu
)
8904 mutex_lock(&pmus_lock
);
8905 free_percpu(pmu
->pmu_cpu_context
);
8906 mutex_unlock(&pmus_lock
);
8910 * Let userspace know that this PMU supports address range filtering:
8912 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8913 struct device_attribute
*attr
,
8916 struct pmu
*pmu
= dev_get_drvdata(dev
);
8918 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8920 DEVICE_ATTR_RO(nr_addr_filters
);
8922 static struct idr pmu_idr
;
8925 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8927 struct pmu
*pmu
= dev_get_drvdata(dev
);
8929 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8931 static DEVICE_ATTR_RO(type
);
8934 perf_event_mux_interval_ms_show(struct device
*dev
,
8935 struct device_attribute
*attr
,
8938 struct pmu
*pmu
= dev_get_drvdata(dev
);
8940 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8943 static DEFINE_MUTEX(mux_interval_mutex
);
8946 perf_event_mux_interval_ms_store(struct device
*dev
,
8947 struct device_attribute
*attr
,
8948 const char *buf
, size_t count
)
8950 struct pmu
*pmu
= dev_get_drvdata(dev
);
8951 int timer
, cpu
, ret
;
8953 ret
= kstrtoint(buf
, 0, &timer
);
8960 /* same value, noting to do */
8961 if (timer
== pmu
->hrtimer_interval_ms
)
8964 mutex_lock(&mux_interval_mutex
);
8965 pmu
->hrtimer_interval_ms
= timer
;
8967 /* update all cpuctx for this PMU */
8969 for_each_online_cpu(cpu
) {
8970 struct perf_cpu_context
*cpuctx
;
8971 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8972 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
8974 cpu_function_call(cpu
,
8975 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
8978 mutex_unlock(&mux_interval_mutex
);
8982 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
8984 static struct attribute
*pmu_dev_attrs
[] = {
8985 &dev_attr_type
.attr
,
8986 &dev_attr_perf_event_mux_interval_ms
.attr
,
8989 ATTRIBUTE_GROUPS(pmu_dev
);
8991 static int pmu_bus_running
;
8992 static struct bus_type pmu_bus
= {
8993 .name
= "event_source",
8994 .dev_groups
= pmu_dev_groups
,
8997 static void pmu_dev_release(struct device
*dev
)
9002 static int pmu_dev_alloc(struct pmu
*pmu
)
9006 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
9010 pmu
->dev
->groups
= pmu
->attr_groups
;
9011 device_initialize(pmu
->dev
);
9012 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
9016 dev_set_drvdata(pmu
->dev
, pmu
);
9017 pmu
->dev
->bus
= &pmu_bus
;
9018 pmu
->dev
->release
= pmu_dev_release
;
9019 ret
= device_add(pmu
->dev
);
9023 /* For PMUs with address filters, throw in an extra attribute: */
9024 if (pmu
->nr_addr_filters
)
9025 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9034 device_del(pmu
->dev
);
9037 put_device(pmu
->dev
);
9041 static struct lock_class_key cpuctx_mutex
;
9042 static struct lock_class_key cpuctx_lock
;
9044 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
9048 mutex_lock(&pmus_lock
);
9050 pmu
->pmu_disable_count
= alloc_percpu(int);
9051 if (!pmu
->pmu_disable_count
)
9060 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
9068 if (pmu_bus_running
) {
9069 ret
= pmu_dev_alloc(pmu
);
9075 if (pmu
->task_ctx_nr
== perf_hw_context
) {
9076 static int hw_context_taken
= 0;
9079 * Other than systems with heterogeneous CPUs, it never makes
9080 * sense for two PMUs to share perf_hw_context. PMUs which are
9081 * uncore must use perf_invalid_context.
9083 if (WARN_ON_ONCE(hw_context_taken
&&
9084 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
9085 pmu
->task_ctx_nr
= perf_invalid_context
;
9087 hw_context_taken
= 1;
9090 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
9091 if (pmu
->pmu_cpu_context
)
9092 goto got_cpu_context
;
9095 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
9096 if (!pmu
->pmu_cpu_context
)
9099 for_each_possible_cpu(cpu
) {
9100 struct perf_cpu_context
*cpuctx
;
9102 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9103 __perf_event_init_context(&cpuctx
->ctx
);
9104 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
9105 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
9106 cpuctx
->ctx
.pmu
= pmu
;
9107 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
9109 __perf_mux_hrtimer_init(cpuctx
, cpu
);
9113 if (!pmu
->start_txn
) {
9114 if (pmu
->pmu_enable
) {
9116 * If we have pmu_enable/pmu_disable calls, install
9117 * transaction stubs that use that to try and batch
9118 * hardware accesses.
9120 pmu
->start_txn
= perf_pmu_start_txn
;
9121 pmu
->commit_txn
= perf_pmu_commit_txn
;
9122 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
9124 pmu
->start_txn
= perf_pmu_nop_txn
;
9125 pmu
->commit_txn
= perf_pmu_nop_int
;
9126 pmu
->cancel_txn
= perf_pmu_nop_void
;
9130 if (!pmu
->pmu_enable
) {
9131 pmu
->pmu_enable
= perf_pmu_nop_void
;
9132 pmu
->pmu_disable
= perf_pmu_nop_void
;
9135 if (!pmu
->event_idx
)
9136 pmu
->event_idx
= perf_event_idx_default
;
9138 list_add_rcu(&pmu
->entry
, &pmus
);
9139 atomic_set(&pmu
->exclusive_cnt
, 0);
9142 mutex_unlock(&pmus_lock
);
9147 device_del(pmu
->dev
);
9148 put_device(pmu
->dev
);
9151 if (pmu
->type
>= PERF_TYPE_MAX
)
9152 idr_remove(&pmu_idr
, pmu
->type
);
9155 free_percpu(pmu
->pmu_disable_count
);
9158 EXPORT_SYMBOL_GPL(perf_pmu_register
);
9160 void perf_pmu_unregister(struct pmu
*pmu
)
9164 mutex_lock(&pmus_lock
);
9165 remove_device
= pmu_bus_running
;
9166 list_del_rcu(&pmu
->entry
);
9167 mutex_unlock(&pmus_lock
);
9170 * We dereference the pmu list under both SRCU and regular RCU, so
9171 * synchronize against both of those.
9173 synchronize_srcu(&pmus_srcu
);
9176 free_percpu(pmu
->pmu_disable_count
);
9177 if (pmu
->type
>= PERF_TYPE_MAX
)
9178 idr_remove(&pmu_idr
, pmu
->type
);
9179 if (remove_device
) {
9180 if (pmu
->nr_addr_filters
)
9181 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9182 device_del(pmu
->dev
);
9183 put_device(pmu
->dev
);
9185 free_pmu_context(pmu
);
9187 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9189 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9191 struct perf_event_context
*ctx
= NULL
;
9194 if (!try_module_get(pmu
->module
))
9197 if (event
->group_leader
!= event
) {
9199 * This ctx->mutex can nest when we're called through
9200 * inheritance. See the perf_event_ctx_lock_nested() comment.
9202 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9203 SINGLE_DEPTH_NESTING
);
9208 ret
= pmu
->event_init(event
);
9211 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9214 module_put(pmu
->module
);
9219 static struct pmu
*perf_init_event(struct perf_event
*event
)
9225 idx
= srcu_read_lock(&pmus_srcu
);
9227 /* Try parent's PMU first: */
9228 if (event
->parent
&& event
->parent
->pmu
) {
9229 pmu
= event
->parent
->pmu
;
9230 ret
= perf_try_init_event(pmu
, event
);
9236 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9239 ret
= perf_try_init_event(pmu
, event
);
9245 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9246 ret
= perf_try_init_event(pmu
, event
);
9250 if (ret
!= -ENOENT
) {
9255 pmu
= ERR_PTR(-ENOENT
);
9257 srcu_read_unlock(&pmus_srcu
, idx
);
9262 static void attach_sb_event(struct perf_event
*event
)
9264 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9266 raw_spin_lock(&pel
->lock
);
9267 list_add_rcu(&event
->sb_list
, &pel
->list
);
9268 raw_spin_unlock(&pel
->lock
);
9272 * We keep a list of all !task (and therefore per-cpu) events
9273 * that need to receive side-band records.
9275 * This avoids having to scan all the various PMU per-cpu contexts
9278 static void account_pmu_sb_event(struct perf_event
*event
)
9280 if (is_sb_event(event
))
9281 attach_sb_event(event
);
9284 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9289 if (is_cgroup_event(event
))
9290 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9293 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9294 static void account_freq_event_nohz(void)
9296 #ifdef CONFIG_NO_HZ_FULL
9297 /* Lock so we don't race with concurrent unaccount */
9298 spin_lock(&nr_freq_lock
);
9299 if (atomic_inc_return(&nr_freq_events
) == 1)
9300 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9301 spin_unlock(&nr_freq_lock
);
9305 static void account_freq_event(void)
9307 if (tick_nohz_full_enabled())
9308 account_freq_event_nohz();
9310 atomic_inc(&nr_freq_events
);
9314 static void account_event(struct perf_event
*event
)
9321 if (event
->attach_state
& PERF_ATTACH_TASK
)
9323 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9324 atomic_inc(&nr_mmap_events
);
9325 if (event
->attr
.comm
)
9326 atomic_inc(&nr_comm_events
);
9327 if (event
->attr
.namespaces
)
9328 atomic_inc(&nr_namespaces_events
);
9329 if (event
->attr
.task
)
9330 atomic_inc(&nr_task_events
);
9331 if (event
->attr
.freq
)
9332 account_freq_event();
9333 if (event
->attr
.context_switch
) {
9334 atomic_inc(&nr_switch_events
);
9337 if (has_branch_stack(event
))
9339 if (is_cgroup_event(event
))
9343 if (atomic_inc_not_zero(&perf_sched_count
))
9346 mutex_lock(&perf_sched_mutex
);
9347 if (!atomic_read(&perf_sched_count
)) {
9348 static_branch_enable(&perf_sched_events
);
9350 * Guarantee that all CPUs observe they key change and
9351 * call the perf scheduling hooks before proceeding to
9352 * install events that need them.
9354 synchronize_sched();
9357 * Now that we have waited for the sync_sched(), allow further
9358 * increments to by-pass the mutex.
9360 atomic_inc(&perf_sched_count
);
9361 mutex_unlock(&perf_sched_mutex
);
9365 account_event_cpu(event
, event
->cpu
);
9367 account_pmu_sb_event(event
);
9371 * Allocate and initialize a event structure
9373 static struct perf_event
*
9374 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9375 struct task_struct
*task
,
9376 struct perf_event
*group_leader
,
9377 struct perf_event
*parent_event
,
9378 perf_overflow_handler_t overflow_handler
,
9379 void *context
, int cgroup_fd
)
9382 struct perf_event
*event
;
9383 struct hw_perf_event
*hwc
;
9386 if ((unsigned)cpu
>= nr_cpu_ids
) {
9387 if (!task
|| cpu
!= -1)
9388 return ERR_PTR(-EINVAL
);
9391 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9393 return ERR_PTR(-ENOMEM
);
9396 * Single events are their own group leaders, with an
9397 * empty sibling list:
9400 group_leader
= event
;
9402 mutex_init(&event
->child_mutex
);
9403 INIT_LIST_HEAD(&event
->child_list
);
9405 INIT_LIST_HEAD(&event
->group_entry
);
9406 INIT_LIST_HEAD(&event
->event_entry
);
9407 INIT_LIST_HEAD(&event
->sibling_list
);
9408 INIT_LIST_HEAD(&event
->rb_entry
);
9409 INIT_LIST_HEAD(&event
->active_entry
);
9410 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9411 INIT_HLIST_NODE(&event
->hlist_entry
);
9414 init_waitqueue_head(&event
->waitq
);
9415 init_irq_work(&event
->pending
, perf_pending_event
);
9417 mutex_init(&event
->mmap_mutex
);
9418 raw_spin_lock_init(&event
->addr_filters
.lock
);
9420 atomic_long_set(&event
->refcount
, 1);
9422 event
->attr
= *attr
;
9423 event
->group_leader
= group_leader
;
9427 event
->parent
= parent_event
;
9429 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9430 event
->id
= atomic64_inc_return(&perf_event_id
);
9432 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9435 event
->attach_state
= PERF_ATTACH_TASK
;
9437 * XXX pmu::event_init needs to know what task to account to
9438 * and we cannot use the ctx information because we need the
9439 * pmu before we get a ctx.
9441 event
->hw
.target
= task
;
9444 event
->clock
= &local_clock
;
9446 event
->clock
= parent_event
->clock
;
9448 if (!overflow_handler
&& parent_event
) {
9449 overflow_handler
= parent_event
->overflow_handler
;
9450 context
= parent_event
->overflow_handler_context
;
9451 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9452 if (overflow_handler
== bpf_overflow_handler
) {
9453 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9456 err
= PTR_ERR(prog
);
9460 event
->orig_overflow_handler
=
9461 parent_event
->orig_overflow_handler
;
9466 if (overflow_handler
) {
9467 event
->overflow_handler
= overflow_handler
;
9468 event
->overflow_handler_context
= context
;
9469 } else if (is_write_backward(event
)){
9470 event
->overflow_handler
= perf_event_output_backward
;
9471 event
->overflow_handler_context
= NULL
;
9473 event
->overflow_handler
= perf_event_output_forward
;
9474 event
->overflow_handler_context
= NULL
;
9477 perf_event__state_init(event
);
9482 hwc
->sample_period
= attr
->sample_period
;
9483 if (attr
->freq
&& attr
->sample_freq
)
9484 hwc
->sample_period
= 1;
9485 hwc
->last_period
= hwc
->sample_period
;
9487 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9490 * We currently do not support PERF_SAMPLE_READ on inherited events.
9491 * See perf_output_read().
9493 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
9496 if (!has_branch_stack(event
))
9497 event
->attr
.branch_sample_type
= 0;
9499 if (cgroup_fd
!= -1) {
9500 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9505 pmu
= perf_init_event(event
);
9511 err
= exclusive_event_init(event
);
9515 if (has_addr_filter(event
)) {
9516 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9517 sizeof(unsigned long),
9519 if (!event
->addr_filters_offs
) {
9524 /* force hw sync on the address filters */
9525 event
->addr_filters_gen
= 1;
9528 if (!event
->parent
) {
9529 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9530 err
= get_callchain_buffers(attr
->sample_max_stack
);
9532 goto err_addr_filters
;
9536 /* symmetric to unaccount_event() in _free_event() */
9537 account_event(event
);
9542 kfree(event
->addr_filters_offs
);
9545 exclusive_event_destroy(event
);
9549 event
->destroy(event
);
9550 module_put(pmu
->module
);
9552 if (is_cgroup_event(event
))
9553 perf_detach_cgroup(event
);
9555 put_pid_ns(event
->ns
);
9558 return ERR_PTR(err
);
9561 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9562 struct perf_event_attr
*attr
)
9567 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9571 * zero the full structure, so that a short copy will be nice.
9573 memset(attr
, 0, sizeof(*attr
));
9575 ret
= get_user(size
, &uattr
->size
);
9579 if (size
> PAGE_SIZE
) /* silly large */
9582 if (!size
) /* abi compat */
9583 size
= PERF_ATTR_SIZE_VER0
;
9585 if (size
< PERF_ATTR_SIZE_VER0
)
9589 * If we're handed a bigger struct than we know of,
9590 * ensure all the unknown bits are 0 - i.e. new
9591 * user-space does not rely on any kernel feature
9592 * extensions we dont know about yet.
9594 if (size
> sizeof(*attr
)) {
9595 unsigned char __user
*addr
;
9596 unsigned char __user
*end
;
9599 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9600 end
= (void __user
*)uattr
+ size
;
9602 for (; addr
< end
; addr
++) {
9603 ret
= get_user(val
, addr
);
9609 size
= sizeof(*attr
);
9612 ret
= copy_from_user(attr
, uattr
, size
);
9616 if (attr
->__reserved_1
)
9619 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9622 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9625 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9626 u64 mask
= attr
->branch_sample_type
;
9628 /* only using defined bits */
9629 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9632 /* at least one branch bit must be set */
9633 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9636 /* propagate priv level, when not set for branch */
9637 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9639 /* exclude_kernel checked on syscall entry */
9640 if (!attr
->exclude_kernel
)
9641 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9643 if (!attr
->exclude_user
)
9644 mask
|= PERF_SAMPLE_BRANCH_USER
;
9646 if (!attr
->exclude_hv
)
9647 mask
|= PERF_SAMPLE_BRANCH_HV
;
9649 * adjust user setting (for HW filter setup)
9651 attr
->branch_sample_type
= mask
;
9653 /* privileged levels capture (kernel, hv): check permissions */
9654 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9655 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9659 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9660 ret
= perf_reg_validate(attr
->sample_regs_user
);
9665 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9666 if (!arch_perf_have_user_stack_dump())
9670 * We have __u32 type for the size, but so far
9671 * we can only use __u16 as maximum due to the
9672 * __u16 sample size limit.
9674 if (attr
->sample_stack_user
>= USHRT_MAX
)
9676 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9680 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9681 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9686 put_user(sizeof(*attr
), &uattr
->size
);
9692 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9694 struct ring_buffer
*rb
= NULL
;
9700 /* don't allow circular references */
9701 if (event
== output_event
)
9705 * Don't allow cross-cpu buffers
9707 if (output_event
->cpu
!= event
->cpu
)
9711 * If its not a per-cpu rb, it must be the same task.
9713 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9717 * Mixing clocks in the same buffer is trouble you don't need.
9719 if (output_event
->clock
!= event
->clock
)
9723 * Either writing ring buffer from beginning or from end.
9724 * Mixing is not allowed.
9726 if (is_write_backward(output_event
) != is_write_backward(event
))
9730 * If both events generate aux data, they must be on the same PMU
9732 if (has_aux(event
) && has_aux(output_event
) &&
9733 event
->pmu
!= output_event
->pmu
)
9737 mutex_lock(&event
->mmap_mutex
);
9738 /* Can't redirect output if we've got an active mmap() */
9739 if (atomic_read(&event
->mmap_count
))
9743 /* get the rb we want to redirect to */
9744 rb
= ring_buffer_get(output_event
);
9749 ring_buffer_attach(event
, rb
);
9753 mutex_unlock(&event
->mmap_mutex
);
9759 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9765 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9768 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9770 bool nmi_safe
= false;
9773 case CLOCK_MONOTONIC
:
9774 event
->clock
= &ktime_get_mono_fast_ns
;
9778 case CLOCK_MONOTONIC_RAW
:
9779 event
->clock
= &ktime_get_raw_fast_ns
;
9783 case CLOCK_REALTIME
:
9784 event
->clock
= &ktime_get_real_ns
;
9787 case CLOCK_BOOTTIME
:
9788 event
->clock
= &ktime_get_boot_ns
;
9792 event
->clock
= &ktime_get_tai_ns
;
9799 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9806 * Variation on perf_event_ctx_lock_nested(), except we take two context
9809 static struct perf_event_context
*
9810 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9811 struct perf_event_context
*ctx
)
9813 struct perf_event_context
*gctx
;
9817 gctx
= READ_ONCE(group_leader
->ctx
);
9818 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9824 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9826 if (group_leader
->ctx
!= gctx
) {
9827 mutex_unlock(&ctx
->mutex
);
9828 mutex_unlock(&gctx
->mutex
);
9837 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9839 * @attr_uptr: event_id type attributes for monitoring/sampling
9842 * @group_fd: group leader event fd
9844 SYSCALL_DEFINE5(perf_event_open
,
9845 struct perf_event_attr __user
*, attr_uptr
,
9846 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9848 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9849 struct perf_event
*event
, *sibling
;
9850 struct perf_event_attr attr
;
9851 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9852 struct file
*event_file
= NULL
;
9853 struct fd group
= {NULL
, 0};
9854 struct task_struct
*task
= NULL
;
9859 int f_flags
= O_RDWR
;
9862 /* for future expandability... */
9863 if (flags
& ~PERF_FLAG_ALL
)
9866 err
= perf_copy_attr(attr_uptr
, &attr
);
9870 if (!attr
.exclude_kernel
) {
9871 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9875 if (attr
.namespaces
) {
9876 if (!capable(CAP_SYS_ADMIN
))
9881 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9884 if (attr
.sample_period
& (1ULL << 63))
9888 if (!attr
.sample_max_stack
)
9889 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9892 * In cgroup mode, the pid argument is used to pass the fd
9893 * opened to the cgroup directory in cgroupfs. The cpu argument
9894 * designates the cpu on which to monitor threads from that
9897 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9900 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9901 f_flags
|= O_CLOEXEC
;
9903 event_fd
= get_unused_fd_flags(f_flags
);
9907 if (group_fd
!= -1) {
9908 err
= perf_fget_light(group_fd
, &group
);
9911 group_leader
= group
.file
->private_data
;
9912 if (flags
& PERF_FLAG_FD_OUTPUT
)
9913 output_event
= group_leader
;
9914 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9915 group_leader
= NULL
;
9918 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9919 task
= find_lively_task_by_vpid(pid
);
9921 err
= PTR_ERR(task
);
9926 if (task
&& group_leader
&&
9927 group_leader
->attr
.inherit
!= attr
.inherit
) {
9933 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
9938 * Reuse ptrace permission checks for now.
9940 * We must hold cred_guard_mutex across this and any potential
9941 * perf_install_in_context() call for this new event to
9942 * serialize against exec() altering our credentials (and the
9943 * perf_event_exit_task() that could imply).
9946 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
9950 if (flags
& PERF_FLAG_PID_CGROUP
)
9953 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
9954 NULL
, NULL
, cgroup_fd
);
9955 if (IS_ERR(event
)) {
9956 err
= PTR_ERR(event
);
9960 if (is_sampling_event(event
)) {
9961 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
9968 * Special case software events and allow them to be part of
9969 * any hardware group.
9973 if (attr
.use_clockid
) {
9974 err
= perf_event_set_clock(event
, attr
.clockid
);
9979 if (pmu
->task_ctx_nr
== perf_sw_context
)
9980 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
9983 (is_software_event(event
) != is_software_event(group_leader
))) {
9984 if (is_software_event(event
)) {
9986 * If event and group_leader are not both a software
9987 * event, and event is, then group leader is not.
9989 * Allow the addition of software events to !software
9990 * groups, this is safe because software events never
9993 pmu
= group_leader
->pmu
;
9994 } else if (is_software_event(group_leader
) &&
9995 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
9997 * In case the group is a pure software group, and we
9998 * try to add a hardware event, move the whole group to
9999 * the hardware context.
10006 * Get the target context (task or percpu):
10008 ctx
= find_get_context(pmu
, task
, event
);
10010 err
= PTR_ERR(ctx
);
10014 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
10020 * Look up the group leader (we will attach this event to it):
10022 if (group_leader
) {
10026 * Do not allow a recursive hierarchy (this new sibling
10027 * becoming part of another group-sibling):
10029 if (group_leader
->group_leader
!= group_leader
)
10032 /* All events in a group should have the same clock */
10033 if (group_leader
->clock
!= event
->clock
)
10037 * Do not allow to attach to a group in a different
10038 * task or CPU context:
10042 * Make sure we're both on the same task, or both
10045 if (group_leader
->ctx
->task
!= ctx
->task
)
10049 * Make sure we're both events for the same CPU;
10050 * grouping events for different CPUs is broken; since
10051 * you can never concurrently schedule them anyhow.
10053 if (group_leader
->cpu
!= event
->cpu
)
10056 if (group_leader
->ctx
!= ctx
)
10061 * Only a group leader can be exclusive or pinned
10063 if (attr
.exclusive
|| attr
.pinned
)
10067 if (output_event
) {
10068 err
= perf_event_set_output(event
, output_event
);
10073 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
10075 if (IS_ERR(event_file
)) {
10076 err
= PTR_ERR(event_file
);
10082 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
10084 if (gctx
->task
== TASK_TOMBSTONE
) {
10090 * Check if we raced against another sys_perf_event_open() call
10091 * moving the software group underneath us.
10093 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10095 * If someone moved the group out from under us, check
10096 * if this new event wound up on the same ctx, if so
10097 * its the regular !move_group case, otherwise fail.
10103 perf_event_ctx_unlock(group_leader
, gctx
);
10108 mutex_lock(&ctx
->mutex
);
10111 if (ctx
->task
== TASK_TOMBSTONE
) {
10116 if (!perf_event_validate_size(event
)) {
10123 * Check if the @cpu we're creating an event for is online.
10125 * We use the perf_cpu_context::ctx::mutex to serialize against
10126 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10128 struct perf_cpu_context
*cpuctx
=
10129 container_of(ctx
, struct perf_cpu_context
, ctx
);
10131 if (!cpuctx
->online
) {
10139 * Must be under the same ctx::mutex as perf_install_in_context(),
10140 * because we need to serialize with concurrent event creation.
10142 if (!exclusive_event_installable(event
, ctx
)) {
10143 /* exclusive and group stuff are assumed mutually exclusive */
10144 WARN_ON_ONCE(move_group
);
10150 WARN_ON_ONCE(ctx
->parent_ctx
);
10153 * This is the point on no return; we cannot fail hereafter. This is
10154 * where we start modifying current state.
10159 * See perf_event_ctx_lock() for comments on the details
10160 * of swizzling perf_event::ctx.
10162 perf_remove_from_context(group_leader
, 0);
10165 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10167 perf_remove_from_context(sibling
, 0);
10172 * Wait for everybody to stop referencing the events through
10173 * the old lists, before installing it on new lists.
10178 * Install the group siblings before the group leader.
10180 * Because a group leader will try and install the entire group
10181 * (through the sibling list, which is still in-tact), we can
10182 * end up with siblings installed in the wrong context.
10184 * By installing siblings first we NO-OP because they're not
10185 * reachable through the group lists.
10187 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10189 perf_event__state_init(sibling
);
10190 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
10195 * Removing from the context ends up with disabled
10196 * event. What we want here is event in the initial
10197 * startup state, ready to be add into new context.
10199 perf_event__state_init(group_leader
);
10200 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
10205 * Precalculate sample_data sizes; do while holding ctx::mutex such
10206 * that we're serialized against further additions and before
10207 * perf_install_in_context() which is the point the event is active and
10208 * can use these values.
10210 perf_event__header_size(event
);
10211 perf_event__id_header_size(event
);
10213 event
->owner
= current
;
10215 perf_install_in_context(ctx
, event
, event
->cpu
);
10216 perf_unpin_context(ctx
);
10219 perf_event_ctx_unlock(group_leader
, gctx
);
10220 mutex_unlock(&ctx
->mutex
);
10223 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10224 put_task_struct(task
);
10227 mutex_lock(¤t
->perf_event_mutex
);
10228 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10229 mutex_unlock(¤t
->perf_event_mutex
);
10232 * Drop the reference on the group_event after placing the
10233 * new event on the sibling_list. This ensures destruction
10234 * of the group leader will find the pointer to itself in
10235 * perf_group_detach().
10238 fd_install(event_fd
, event_file
);
10243 perf_event_ctx_unlock(group_leader
, gctx
);
10244 mutex_unlock(&ctx
->mutex
);
10248 perf_unpin_context(ctx
);
10252 * If event_file is set, the fput() above will have called ->release()
10253 * and that will take care of freeing the event.
10259 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10262 put_task_struct(task
);
10266 put_unused_fd(event_fd
);
10271 * perf_event_create_kernel_counter
10273 * @attr: attributes of the counter to create
10274 * @cpu: cpu in which the counter is bound
10275 * @task: task to profile (NULL for percpu)
10277 struct perf_event
*
10278 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10279 struct task_struct
*task
,
10280 perf_overflow_handler_t overflow_handler
,
10283 struct perf_event_context
*ctx
;
10284 struct perf_event
*event
;
10288 * Get the target context (task or percpu):
10291 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10292 overflow_handler
, context
, -1);
10293 if (IS_ERR(event
)) {
10294 err
= PTR_ERR(event
);
10298 /* Mark owner so we could distinguish it from user events. */
10299 event
->owner
= TASK_TOMBSTONE
;
10301 ctx
= find_get_context(event
->pmu
, task
, event
);
10303 err
= PTR_ERR(ctx
);
10307 WARN_ON_ONCE(ctx
->parent_ctx
);
10308 mutex_lock(&ctx
->mutex
);
10309 if (ctx
->task
== TASK_TOMBSTONE
) {
10316 * Check if the @cpu we're creating an event for is online.
10318 * We use the perf_cpu_context::ctx::mutex to serialize against
10319 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10321 struct perf_cpu_context
*cpuctx
=
10322 container_of(ctx
, struct perf_cpu_context
, ctx
);
10323 if (!cpuctx
->online
) {
10329 if (!exclusive_event_installable(event
, ctx
)) {
10334 perf_install_in_context(ctx
, event
, cpu
);
10335 perf_unpin_context(ctx
);
10336 mutex_unlock(&ctx
->mutex
);
10341 mutex_unlock(&ctx
->mutex
);
10342 perf_unpin_context(ctx
);
10347 return ERR_PTR(err
);
10349 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10351 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10353 struct perf_event_context
*src_ctx
;
10354 struct perf_event_context
*dst_ctx
;
10355 struct perf_event
*event
, *tmp
;
10358 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10359 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10362 * See perf_event_ctx_lock() for comments on the details
10363 * of swizzling perf_event::ctx.
10365 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10366 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10368 perf_remove_from_context(event
, 0);
10369 unaccount_event_cpu(event
, src_cpu
);
10371 list_add(&event
->migrate_entry
, &events
);
10375 * Wait for the events to quiesce before re-instating them.
10380 * Re-instate events in 2 passes.
10382 * Skip over group leaders and only install siblings on this first
10383 * pass, siblings will not get enabled without a leader, however a
10384 * leader will enable its siblings, even if those are still on the old
10387 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10388 if (event
->group_leader
== event
)
10391 list_del(&event
->migrate_entry
);
10392 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10393 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10394 account_event_cpu(event
, dst_cpu
);
10395 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10400 * Once all the siblings are setup properly, install the group leaders
10403 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10404 list_del(&event
->migrate_entry
);
10405 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10406 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10407 account_event_cpu(event
, dst_cpu
);
10408 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10411 mutex_unlock(&dst_ctx
->mutex
);
10412 mutex_unlock(&src_ctx
->mutex
);
10414 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10416 static void sync_child_event(struct perf_event
*child_event
,
10417 struct task_struct
*child
)
10419 struct perf_event
*parent_event
= child_event
->parent
;
10422 if (child_event
->attr
.inherit_stat
)
10423 perf_event_read_event(child_event
, child
);
10425 child_val
= perf_event_count(child_event
);
10428 * Add back the child's count to the parent's count:
10430 atomic64_add(child_val
, &parent_event
->child_count
);
10431 atomic64_add(child_event
->total_time_enabled
,
10432 &parent_event
->child_total_time_enabled
);
10433 atomic64_add(child_event
->total_time_running
,
10434 &parent_event
->child_total_time_running
);
10438 perf_event_exit_event(struct perf_event
*child_event
,
10439 struct perf_event_context
*child_ctx
,
10440 struct task_struct
*child
)
10442 struct perf_event
*parent_event
= child_event
->parent
;
10445 * Do not destroy the 'original' grouping; because of the context
10446 * switch optimization the original events could've ended up in a
10447 * random child task.
10449 * If we were to destroy the original group, all group related
10450 * operations would cease to function properly after this random
10453 * Do destroy all inherited groups, we don't care about those
10454 * and being thorough is better.
10456 raw_spin_lock_irq(&child_ctx
->lock
);
10457 WARN_ON_ONCE(child_ctx
->is_active
);
10460 perf_group_detach(child_event
);
10461 list_del_event(child_event
, child_ctx
);
10462 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
10463 raw_spin_unlock_irq(&child_ctx
->lock
);
10466 * Parent events are governed by their filedesc, retain them.
10468 if (!parent_event
) {
10469 perf_event_wakeup(child_event
);
10473 * Child events can be cleaned up.
10476 sync_child_event(child_event
, child
);
10479 * Remove this event from the parent's list
10481 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10482 mutex_lock(&parent_event
->child_mutex
);
10483 list_del_init(&child_event
->child_list
);
10484 mutex_unlock(&parent_event
->child_mutex
);
10487 * Kick perf_poll() for is_event_hup().
10489 perf_event_wakeup(parent_event
);
10490 free_event(child_event
);
10491 put_event(parent_event
);
10494 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10496 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10497 struct perf_event
*child_event
, *next
;
10499 WARN_ON_ONCE(child
!= current
);
10501 child_ctx
= perf_pin_task_context(child
, ctxn
);
10506 * In order to reduce the amount of tricky in ctx tear-down, we hold
10507 * ctx::mutex over the entire thing. This serializes against almost
10508 * everything that wants to access the ctx.
10510 * The exception is sys_perf_event_open() /
10511 * perf_event_create_kernel_count() which does find_get_context()
10512 * without ctx::mutex (it cannot because of the move_group double mutex
10513 * lock thing). See the comments in perf_install_in_context().
10515 mutex_lock(&child_ctx
->mutex
);
10518 * In a single ctx::lock section, de-schedule the events and detach the
10519 * context from the task such that we cannot ever get it scheduled back
10522 raw_spin_lock_irq(&child_ctx
->lock
);
10523 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
10526 * Now that the context is inactive, destroy the task <-> ctx relation
10527 * and mark the context dead.
10529 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10530 put_ctx(child_ctx
); /* cannot be last */
10531 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10532 put_task_struct(current
); /* cannot be last */
10534 clone_ctx
= unclone_ctx(child_ctx
);
10535 raw_spin_unlock_irq(&child_ctx
->lock
);
10538 put_ctx(clone_ctx
);
10541 * Report the task dead after unscheduling the events so that we
10542 * won't get any samples after PERF_RECORD_EXIT. We can however still
10543 * get a few PERF_RECORD_READ events.
10545 perf_event_task(child
, child_ctx
, 0);
10547 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10548 perf_event_exit_event(child_event
, child_ctx
, child
);
10550 mutex_unlock(&child_ctx
->mutex
);
10552 put_ctx(child_ctx
);
10556 * When a child task exits, feed back event values to parent events.
10558 * Can be called with cred_guard_mutex held when called from
10559 * install_exec_creds().
10561 void perf_event_exit_task(struct task_struct
*child
)
10563 struct perf_event
*event
, *tmp
;
10566 mutex_lock(&child
->perf_event_mutex
);
10567 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10569 list_del_init(&event
->owner_entry
);
10572 * Ensure the list deletion is visible before we clear
10573 * the owner, closes a race against perf_release() where
10574 * we need to serialize on the owner->perf_event_mutex.
10576 smp_store_release(&event
->owner
, NULL
);
10578 mutex_unlock(&child
->perf_event_mutex
);
10580 for_each_task_context_nr(ctxn
)
10581 perf_event_exit_task_context(child
, ctxn
);
10584 * The perf_event_exit_task_context calls perf_event_task
10585 * with child's task_ctx, which generates EXIT events for
10586 * child contexts and sets child->perf_event_ctxp[] to NULL.
10587 * At this point we need to send EXIT events to cpu contexts.
10589 perf_event_task(child
, NULL
, 0);
10592 static void perf_free_event(struct perf_event
*event
,
10593 struct perf_event_context
*ctx
)
10595 struct perf_event
*parent
= event
->parent
;
10597 if (WARN_ON_ONCE(!parent
))
10600 mutex_lock(&parent
->child_mutex
);
10601 list_del_init(&event
->child_list
);
10602 mutex_unlock(&parent
->child_mutex
);
10606 raw_spin_lock_irq(&ctx
->lock
);
10607 perf_group_detach(event
);
10608 list_del_event(event
, ctx
);
10609 raw_spin_unlock_irq(&ctx
->lock
);
10614 * Free an unexposed, unused context as created by inheritance by
10615 * perf_event_init_task below, used by fork() in case of fail.
10617 * Not all locks are strictly required, but take them anyway to be nice and
10618 * help out with the lockdep assertions.
10620 void perf_event_free_task(struct task_struct
*task
)
10622 struct perf_event_context
*ctx
;
10623 struct perf_event
*event
, *tmp
;
10626 for_each_task_context_nr(ctxn
) {
10627 ctx
= task
->perf_event_ctxp
[ctxn
];
10631 mutex_lock(&ctx
->mutex
);
10632 raw_spin_lock_irq(&ctx
->lock
);
10634 * Destroy the task <-> ctx relation and mark the context dead.
10636 * This is important because even though the task hasn't been
10637 * exposed yet the context has been (through child_list).
10639 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
10640 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
10641 put_task_struct(task
); /* cannot be last */
10642 raw_spin_unlock_irq(&ctx
->lock
);
10644 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
10645 perf_free_event(event
, ctx
);
10647 mutex_unlock(&ctx
->mutex
);
10652 void perf_event_delayed_put(struct task_struct
*task
)
10656 for_each_task_context_nr(ctxn
)
10657 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10660 struct file
*perf_event_get(unsigned int fd
)
10664 file
= fget_raw(fd
);
10666 return ERR_PTR(-EBADF
);
10668 if (file
->f_op
!= &perf_fops
) {
10670 return ERR_PTR(-EBADF
);
10676 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10679 return ERR_PTR(-EINVAL
);
10681 return &event
->attr
;
10685 * Inherit a event from parent task to child task.
10688 * - valid pointer on success
10689 * - NULL for orphaned events
10690 * - IS_ERR() on error
10692 static struct perf_event
*
10693 inherit_event(struct perf_event
*parent_event
,
10694 struct task_struct
*parent
,
10695 struct perf_event_context
*parent_ctx
,
10696 struct task_struct
*child
,
10697 struct perf_event
*group_leader
,
10698 struct perf_event_context
*child_ctx
)
10700 enum perf_event_active_state parent_state
= parent_event
->state
;
10701 struct perf_event
*child_event
;
10702 unsigned long flags
;
10705 * Instead of creating recursive hierarchies of events,
10706 * we link inherited events back to the original parent,
10707 * which has a filp for sure, which we use as the reference
10710 if (parent_event
->parent
)
10711 parent_event
= parent_event
->parent
;
10713 child_event
= perf_event_alloc(&parent_event
->attr
,
10716 group_leader
, parent_event
,
10718 if (IS_ERR(child_event
))
10719 return child_event
;
10722 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10723 * must be under the same lock in order to serialize against
10724 * perf_event_release_kernel(), such that either we must observe
10725 * is_orphaned_event() or they will observe us on the child_list.
10727 mutex_lock(&parent_event
->child_mutex
);
10728 if (is_orphaned_event(parent_event
) ||
10729 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10730 mutex_unlock(&parent_event
->child_mutex
);
10731 free_event(child_event
);
10735 get_ctx(child_ctx
);
10738 * Make the child state follow the state of the parent event,
10739 * not its attr.disabled bit. We hold the parent's mutex,
10740 * so we won't race with perf_event_{en, dis}able_family.
10742 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10743 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10745 child_event
->state
= PERF_EVENT_STATE_OFF
;
10747 if (parent_event
->attr
.freq
) {
10748 u64 sample_period
= parent_event
->hw
.sample_period
;
10749 struct hw_perf_event
*hwc
= &child_event
->hw
;
10751 hwc
->sample_period
= sample_period
;
10752 hwc
->last_period
= sample_period
;
10754 local64_set(&hwc
->period_left
, sample_period
);
10757 child_event
->ctx
= child_ctx
;
10758 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10759 child_event
->overflow_handler_context
10760 = parent_event
->overflow_handler_context
;
10763 * Precalculate sample_data sizes
10765 perf_event__header_size(child_event
);
10766 perf_event__id_header_size(child_event
);
10769 * Link it up in the child's context:
10771 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10772 add_event_to_ctx(child_event
, child_ctx
);
10773 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10776 * Link this into the parent event's child list
10778 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10779 mutex_unlock(&parent_event
->child_mutex
);
10781 return child_event
;
10785 * Inherits an event group.
10787 * This will quietly suppress orphaned events; !inherit_event() is not an error.
10788 * This matches with perf_event_release_kernel() removing all child events.
10794 static int inherit_group(struct perf_event
*parent_event
,
10795 struct task_struct
*parent
,
10796 struct perf_event_context
*parent_ctx
,
10797 struct task_struct
*child
,
10798 struct perf_event_context
*child_ctx
)
10800 struct perf_event
*leader
;
10801 struct perf_event
*sub
;
10802 struct perf_event
*child_ctr
;
10804 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10805 child
, NULL
, child_ctx
);
10806 if (IS_ERR(leader
))
10807 return PTR_ERR(leader
);
10809 * @leader can be NULL here because of is_orphaned_event(). In this
10810 * case inherit_event() will create individual events, similar to what
10811 * perf_group_detach() would do anyway.
10813 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10814 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10815 child
, leader
, child_ctx
);
10816 if (IS_ERR(child_ctr
))
10817 return PTR_ERR(child_ctr
);
10823 * Creates the child task context and tries to inherit the event-group.
10825 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
10826 * inherited_all set when we 'fail' to inherit an orphaned event; this is
10827 * consistent with perf_event_release_kernel() removing all child events.
10834 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10835 struct perf_event_context
*parent_ctx
,
10836 struct task_struct
*child
, int ctxn
,
10837 int *inherited_all
)
10840 struct perf_event_context
*child_ctx
;
10842 if (!event
->attr
.inherit
) {
10843 *inherited_all
= 0;
10847 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10850 * This is executed from the parent task context, so
10851 * inherit events that have been marked for cloning.
10852 * First allocate and initialize a context for the
10855 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10859 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10862 ret
= inherit_group(event
, parent
, parent_ctx
,
10866 *inherited_all
= 0;
10872 * Initialize the perf_event context in task_struct
10874 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10876 struct perf_event_context
*child_ctx
, *parent_ctx
;
10877 struct perf_event_context
*cloned_ctx
;
10878 struct perf_event
*event
;
10879 struct task_struct
*parent
= current
;
10880 int inherited_all
= 1;
10881 unsigned long flags
;
10884 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10888 * If the parent's context is a clone, pin it so it won't get
10889 * swapped under us.
10891 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10896 * No need to check if parent_ctx != NULL here; since we saw
10897 * it non-NULL earlier, the only reason for it to become NULL
10898 * is if we exit, and since we're currently in the middle of
10899 * a fork we can't be exiting at the same time.
10903 * Lock the parent list. No need to lock the child - not PID
10904 * hashed yet and not running, so nobody can access it.
10906 mutex_lock(&parent_ctx
->mutex
);
10909 * We dont have to disable NMIs - we are only looking at
10910 * the list, not manipulating it:
10912 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10913 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10914 child
, ctxn
, &inherited_all
);
10920 * We can't hold ctx->lock when iterating the ->flexible_group list due
10921 * to allocations, but we need to prevent rotation because
10922 * rotate_ctx() will change the list from interrupt context.
10924 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10925 parent_ctx
->rotate_disable
= 1;
10926 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10928 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10929 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10930 child
, ctxn
, &inherited_all
);
10935 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10936 parent_ctx
->rotate_disable
= 0;
10938 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10940 if (child_ctx
&& inherited_all
) {
10942 * Mark the child context as a clone of the parent
10943 * context, or of whatever the parent is a clone of.
10945 * Note that if the parent is a clone, the holding of
10946 * parent_ctx->lock avoids it from being uncloned.
10948 cloned_ctx
= parent_ctx
->parent_ctx
;
10950 child_ctx
->parent_ctx
= cloned_ctx
;
10951 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
10953 child_ctx
->parent_ctx
= parent_ctx
;
10954 child_ctx
->parent_gen
= parent_ctx
->generation
;
10956 get_ctx(child_ctx
->parent_ctx
);
10959 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10961 mutex_unlock(&parent_ctx
->mutex
);
10963 perf_unpin_context(parent_ctx
);
10964 put_ctx(parent_ctx
);
10970 * Initialize the perf_event context in task_struct
10972 int perf_event_init_task(struct task_struct
*child
)
10976 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
10977 mutex_init(&child
->perf_event_mutex
);
10978 INIT_LIST_HEAD(&child
->perf_event_list
);
10980 for_each_task_context_nr(ctxn
) {
10981 ret
= perf_event_init_context(child
, ctxn
);
10983 perf_event_free_task(child
);
10991 static void __init
perf_event_init_all_cpus(void)
10993 struct swevent_htable
*swhash
;
10996 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
10998 for_each_possible_cpu(cpu
) {
10999 swhash
= &per_cpu(swevent_htable
, cpu
);
11000 mutex_init(&swhash
->hlist_mutex
);
11001 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
11003 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
11004 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
11006 #ifdef CONFIG_CGROUP_PERF
11007 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
11009 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
11013 void perf_swevent_init_cpu(unsigned int cpu
)
11015 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
11017 mutex_lock(&swhash
->hlist_mutex
);
11018 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
11019 struct swevent_hlist
*hlist
;
11021 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
11023 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
11025 mutex_unlock(&swhash
->hlist_mutex
);
11028 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
11029 static void __perf_event_exit_context(void *__info
)
11031 struct perf_event_context
*ctx
= __info
;
11032 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
11033 struct perf_event
*event
;
11035 raw_spin_lock(&ctx
->lock
);
11036 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
11037 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
11038 raw_spin_unlock(&ctx
->lock
);
11041 static void perf_event_exit_cpu_context(int cpu
)
11043 struct perf_cpu_context
*cpuctx
;
11044 struct perf_event_context
*ctx
;
11047 mutex_lock(&pmus_lock
);
11048 list_for_each_entry(pmu
, &pmus
, entry
) {
11049 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11050 ctx
= &cpuctx
->ctx
;
11052 mutex_lock(&ctx
->mutex
);
11053 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
11054 cpuctx
->online
= 0;
11055 mutex_unlock(&ctx
->mutex
);
11057 cpumask_clear_cpu(cpu
, perf_online_mask
);
11058 mutex_unlock(&pmus_lock
);
11062 static void perf_event_exit_cpu_context(int cpu
) { }
11066 int perf_event_init_cpu(unsigned int cpu
)
11068 struct perf_cpu_context
*cpuctx
;
11069 struct perf_event_context
*ctx
;
11072 perf_swevent_init_cpu(cpu
);
11074 mutex_lock(&pmus_lock
);
11075 cpumask_set_cpu(cpu
, perf_online_mask
);
11076 list_for_each_entry(pmu
, &pmus
, entry
) {
11077 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11078 ctx
= &cpuctx
->ctx
;
11080 mutex_lock(&ctx
->mutex
);
11081 cpuctx
->online
= 1;
11082 mutex_unlock(&ctx
->mutex
);
11084 mutex_unlock(&pmus_lock
);
11089 int perf_event_exit_cpu(unsigned int cpu
)
11091 perf_event_exit_cpu_context(cpu
);
11096 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
11100 for_each_online_cpu(cpu
)
11101 perf_event_exit_cpu(cpu
);
11107 * Run the perf reboot notifier at the very last possible moment so that
11108 * the generic watchdog code runs as long as possible.
11110 static struct notifier_block perf_reboot_notifier
= {
11111 .notifier_call
= perf_reboot
,
11112 .priority
= INT_MIN
,
11115 void __init
perf_event_init(void)
11119 idr_init(&pmu_idr
);
11121 perf_event_init_all_cpus();
11122 init_srcu_struct(&pmus_srcu
);
11123 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
11124 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
11125 perf_pmu_register(&perf_task_clock
, NULL
, -1);
11126 perf_tp_register();
11127 perf_event_init_cpu(smp_processor_id());
11128 register_reboot_notifier(&perf_reboot_notifier
);
11130 ret
= init_hw_breakpoint();
11131 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
11134 * Build time assertion that we keep the data_head at the intended
11135 * location. IOW, validation we got the __reserved[] size right.
11137 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
11141 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
11144 struct perf_pmu_events_attr
*pmu_attr
=
11145 container_of(attr
, struct perf_pmu_events_attr
, attr
);
11147 if (pmu_attr
->event_str
)
11148 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
11152 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
11154 static int __init
perf_event_sysfs_init(void)
11159 mutex_lock(&pmus_lock
);
11161 ret
= bus_register(&pmu_bus
);
11165 list_for_each_entry(pmu
, &pmus
, entry
) {
11166 if (!pmu
->name
|| pmu
->type
< 0)
11169 ret
= pmu_dev_alloc(pmu
);
11170 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
11172 pmu_bus_running
= 1;
11176 mutex_unlock(&pmus_lock
);
11180 device_initcall(perf_event_sysfs_init
);
11182 #ifdef CONFIG_CGROUP_PERF
11183 static struct cgroup_subsys_state
*
11184 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
11186 struct perf_cgroup
*jc
;
11188 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
11190 return ERR_PTR(-ENOMEM
);
11192 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
11195 return ERR_PTR(-ENOMEM
);
11201 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
11203 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
11205 free_percpu(jc
->info
);
11209 static int __perf_cgroup_move(void *info
)
11211 struct task_struct
*task
= info
;
11213 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
11218 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
11220 struct task_struct
*task
;
11221 struct cgroup_subsys_state
*css
;
11223 cgroup_taskset_for_each(task
, css
, tset
)
11224 task_function_call(task
, __perf_cgroup_move
, task
);
11227 struct cgroup_subsys perf_event_cgrp_subsys
= {
11228 .css_alloc
= perf_cgroup_css_alloc
,
11229 .css_free
= perf_cgroup_css_free
,
11230 .attach
= perf_cgroup_attach
,
11232 * Implicitly enable on dfl hierarchy so that perf events can
11233 * always be filtered by cgroup2 path as long as perf_event
11234 * controller is not mounted on a legacy hierarchy.
11236 .implicit_on_dfl
= true,
11238 #endif /* CONFIG_CGROUP_PERF */