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
);
1455 event_type
= event
->attr
.pinned
? EVENT_PINNED
: EVENT_FLEXIBLE
;
1457 event_type
|= EVENT_CPU
;
1462 static struct list_head
*
1463 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1465 if (event
->attr
.pinned
)
1466 return &ctx
->pinned_groups
;
1468 return &ctx
->flexible_groups
;
1472 * Add a event from the lists for its context.
1473 * Must be called with ctx->mutex and ctx->lock held.
1476 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1478 lockdep_assert_held(&ctx
->lock
);
1480 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1481 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1484 * If we're a stand alone event or group leader, we go to the context
1485 * list, group events are kept attached to the group so that
1486 * perf_group_detach can, at all times, locate all siblings.
1488 if (event
->group_leader
== event
) {
1489 struct list_head
*list
;
1491 event
->group_caps
= event
->event_caps
;
1493 list
= ctx_group_list(event
, ctx
);
1494 list_add_tail(&event
->group_entry
, list
);
1497 list_update_cgroup_event(event
, ctx
, true);
1499 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1501 if (event
->attr
.inherit_stat
)
1508 * Initialize event state based on the perf_event_attr::disabled.
1510 static inline void perf_event__state_init(struct perf_event
*event
)
1512 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1513 PERF_EVENT_STATE_INACTIVE
;
1516 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1518 int entry
= sizeof(u64
); /* value */
1522 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1523 size
+= sizeof(u64
);
1525 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1526 size
+= sizeof(u64
);
1528 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1529 entry
+= sizeof(u64
);
1531 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1533 size
+= sizeof(u64
);
1537 event
->read_size
= size
;
1540 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1542 struct perf_sample_data
*data
;
1545 if (sample_type
& PERF_SAMPLE_IP
)
1546 size
+= sizeof(data
->ip
);
1548 if (sample_type
& PERF_SAMPLE_ADDR
)
1549 size
+= sizeof(data
->addr
);
1551 if (sample_type
& PERF_SAMPLE_PERIOD
)
1552 size
+= sizeof(data
->period
);
1554 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1555 size
+= sizeof(data
->weight
);
1557 if (sample_type
& PERF_SAMPLE_READ
)
1558 size
+= event
->read_size
;
1560 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1561 size
+= sizeof(data
->data_src
.val
);
1563 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1564 size
+= sizeof(data
->txn
);
1566 event
->header_size
= size
;
1570 * Called at perf_event creation and when events are attached/detached from a
1573 static void perf_event__header_size(struct perf_event
*event
)
1575 __perf_event_read_size(event
,
1576 event
->group_leader
->nr_siblings
);
1577 __perf_event_header_size(event
, event
->attr
.sample_type
);
1580 static void perf_event__id_header_size(struct perf_event
*event
)
1582 struct perf_sample_data
*data
;
1583 u64 sample_type
= event
->attr
.sample_type
;
1586 if (sample_type
& PERF_SAMPLE_TID
)
1587 size
+= sizeof(data
->tid_entry
);
1589 if (sample_type
& PERF_SAMPLE_TIME
)
1590 size
+= sizeof(data
->time
);
1592 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1593 size
+= sizeof(data
->id
);
1595 if (sample_type
& PERF_SAMPLE_ID
)
1596 size
+= sizeof(data
->id
);
1598 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1599 size
+= sizeof(data
->stream_id
);
1601 if (sample_type
& PERF_SAMPLE_CPU
)
1602 size
+= sizeof(data
->cpu_entry
);
1604 event
->id_header_size
= size
;
1607 static bool perf_event_validate_size(struct perf_event
*event
)
1610 * The values computed here will be over-written when we actually
1613 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1614 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1615 perf_event__id_header_size(event
);
1618 * Sum the lot; should not exceed the 64k limit we have on records.
1619 * Conservative limit to allow for callchains and other variable fields.
1621 if (event
->read_size
+ event
->header_size
+
1622 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1628 static void perf_group_attach(struct perf_event
*event
)
1630 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1632 lockdep_assert_held(&event
->ctx
->lock
);
1635 * We can have double attach due to group movement in perf_event_open.
1637 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1640 event
->attach_state
|= PERF_ATTACH_GROUP
;
1642 if (group_leader
== event
)
1645 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1647 group_leader
->group_caps
&= event
->event_caps
;
1649 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1650 group_leader
->nr_siblings
++;
1652 perf_event__header_size(group_leader
);
1654 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1655 perf_event__header_size(pos
);
1659 * Remove a event from the lists for its context.
1660 * Must be called with ctx->mutex and ctx->lock held.
1663 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1665 WARN_ON_ONCE(event
->ctx
!= ctx
);
1666 lockdep_assert_held(&ctx
->lock
);
1669 * We can have double detach due to exit/hot-unplug + close.
1671 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1674 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1676 list_update_cgroup_event(event
, ctx
, false);
1679 if (event
->attr
.inherit_stat
)
1682 list_del_rcu(&event
->event_entry
);
1684 if (event
->group_leader
== event
)
1685 list_del_init(&event
->group_entry
);
1687 update_group_times(event
);
1690 * If event was in error state, then keep it
1691 * that way, otherwise bogus counts will be
1692 * returned on read(). The only way to get out
1693 * of error state is by explicit re-enabling
1696 if (event
->state
> PERF_EVENT_STATE_OFF
)
1697 event
->state
= PERF_EVENT_STATE_OFF
;
1702 static void perf_group_detach(struct perf_event
*event
)
1704 struct perf_event
*sibling
, *tmp
;
1705 struct list_head
*list
= NULL
;
1707 lockdep_assert_held(&event
->ctx
->lock
);
1710 * We can have double detach due to exit/hot-unplug + close.
1712 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1715 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1718 * If this is a sibling, remove it from its group.
1720 if (event
->group_leader
!= event
) {
1721 list_del_init(&event
->group_entry
);
1722 event
->group_leader
->nr_siblings
--;
1726 if (!list_empty(&event
->group_entry
))
1727 list
= &event
->group_entry
;
1730 * If this was a group event with sibling events then
1731 * upgrade the siblings to singleton events by adding them
1732 * to whatever list we are on.
1734 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1736 list_move_tail(&sibling
->group_entry
, list
);
1737 sibling
->group_leader
= sibling
;
1739 /* Inherit group flags from the previous leader */
1740 sibling
->group_caps
= event
->group_caps
;
1742 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1746 perf_event__header_size(event
->group_leader
);
1748 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1749 perf_event__header_size(tmp
);
1752 static bool is_orphaned_event(struct perf_event
*event
)
1754 return event
->state
== PERF_EVENT_STATE_DEAD
;
1757 static inline int __pmu_filter_match(struct perf_event
*event
)
1759 struct pmu
*pmu
= event
->pmu
;
1760 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1764 * Check whether we should attempt to schedule an event group based on
1765 * PMU-specific filtering. An event group can consist of HW and SW events,
1766 * potentially with a SW leader, so we must check all the filters, to
1767 * determine whether a group is schedulable:
1769 static inline int pmu_filter_match(struct perf_event
*event
)
1771 struct perf_event
*child
;
1773 if (!__pmu_filter_match(event
))
1776 list_for_each_entry(child
, &event
->sibling_list
, group_entry
) {
1777 if (!__pmu_filter_match(child
))
1785 event_filter_match(struct perf_event
*event
)
1787 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id()) &&
1788 perf_cgroup_match(event
) && pmu_filter_match(event
);
1792 event_sched_out(struct perf_event
*event
,
1793 struct perf_cpu_context
*cpuctx
,
1794 struct perf_event_context
*ctx
)
1796 u64 tstamp
= perf_event_time(event
);
1799 WARN_ON_ONCE(event
->ctx
!= ctx
);
1800 lockdep_assert_held(&ctx
->lock
);
1803 * An event which could not be activated because of
1804 * filter mismatch still needs to have its timings
1805 * maintained, otherwise bogus information is return
1806 * via read() for time_enabled, time_running:
1808 if (event
->state
== PERF_EVENT_STATE_INACTIVE
&&
1809 !event_filter_match(event
)) {
1810 delta
= tstamp
- event
->tstamp_stopped
;
1811 event
->tstamp_running
+= delta
;
1812 event
->tstamp_stopped
= tstamp
;
1815 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1818 perf_pmu_disable(event
->pmu
);
1820 event
->tstamp_stopped
= tstamp
;
1821 event
->pmu
->del(event
, 0);
1823 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1824 if (event
->pending_disable
) {
1825 event
->pending_disable
= 0;
1826 event
->state
= PERF_EVENT_STATE_OFF
;
1829 if (!is_software_event(event
))
1830 cpuctx
->active_oncpu
--;
1831 if (!--ctx
->nr_active
)
1832 perf_event_ctx_deactivate(ctx
);
1833 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1835 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1836 cpuctx
->exclusive
= 0;
1838 perf_pmu_enable(event
->pmu
);
1842 group_sched_out(struct perf_event
*group_event
,
1843 struct perf_cpu_context
*cpuctx
,
1844 struct perf_event_context
*ctx
)
1846 struct perf_event
*event
;
1847 int state
= group_event
->state
;
1849 perf_pmu_disable(ctx
->pmu
);
1851 event_sched_out(group_event
, cpuctx
, ctx
);
1854 * Schedule out siblings (if any):
1856 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1857 event_sched_out(event
, cpuctx
, ctx
);
1859 perf_pmu_enable(ctx
->pmu
);
1861 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1862 cpuctx
->exclusive
= 0;
1865 #define DETACH_GROUP 0x01UL
1868 * Cross CPU call to remove a performance event
1870 * We disable the event on the hardware level first. After that we
1871 * remove it from the context list.
1874 __perf_remove_from_context(struct perf_event
*event
,
1875 struct perf_cpu_context
*cpuctx
,
1876 struct perf_event_context
*ctx
,
1879 unsigned long flags
= (unsigned long)info
;
1881 event_sched_out(event
, cpuctx
, ctx
);
1882 if (flags
& DETACH_GROUP
)
1883 perf_group_detach(event
);
1884 list_del_event(event
, ctx
);
1886 if (!ctx
->nr_events
&& ctx
->is_active
) {
1889 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
1890 cpuctx
->task_ctx
= NULL
;
1896 * Remove the event from a task's (or a CPU's) list of events.
1898 * If event->ctx is a cloned context, callers must make sure that
1899 * every task struct that event->ctx->task could possibly point to
1900 * remains valid. This is OK when called from perf_release since
1901 * that only calls us on the top-level context, which can't be a clone.
1902 * When called from perf_event_exit_task, it's OK because the
1903 * context has been detached from its task.
1905 static void perf_remove_from_context(struct perf_event
*event
, unsigned long flags
)
1907 struct perf_event_context
*ctx
= event
->ctx
;
1909 lockdep_assert_held(&ctx
->mutex
);
1911 event_function_call(event
, __perf_remove_from_context
, (void *)flags
);
1914 * The above event_function_call() can NO-OP when it hits
1915 * TASK_TOMBSTONE. In that case we must already have been detached
1916 * from the context (by perf_event_exit_event()) but the grouping
1917 * might still be in-tact.
1919 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1920 if ((flags
& DETACH_GROUP
) &&
1921 (event
->attach_state
& PERF_ATTACH_GROUP
)) {
1923 * Since in that case we cannot possibly be scheduled, simply
1926 raw_spin_lock_irq(&ctx
->lock
);
1927 perf_group_detach(event
);
1928 raw_spin_unlock_irq(&ctx
->lock
);
1933 * Cross CPU call to disable a performance event
1935 static void __perf_event_disable(struct perf_event
*event
,
1936 struct perf_cpu_context
*cpuctx
,
1937 struct perf_event_context
*ctx
,
1940 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
1943 update_context_time(ctx
);
1944 update_cgrp_time_from_event(event
);
1945 update_group_times(event
);
1946 if (event
== event
->group_leader
)
1947 group_sched_out(event
, cpuctx
, ctx
);
1949 event_sched_out(event
, cpuctx
, ctx
);
1950 event
->state
= PERF_EVENT_STATE_OFF
;
1956 * If event->ctx is a cloned context, callers must make sure that
1957 * every task struct that event->ctx->task could possibly point to
1958 * remains valid. This condition is satisifed when called through
1959 * perf_event_for_each_child or perf_event_for_each because they
1960 * hold the top-level event's child_mutex, so any descendant that
1961 * goes to exit will block in perf_event_exit_event().
1963 * When called from perf_pending_event it's OK because event->ctx
1964 * is the current context on this CPU and preemption is disabled,
1965 * hence we can't get into perf_event_task_sched_out for this context.
1967 static void _perf_event_disable(struct perf_event
*event
)
1969 struct perf_event_context
*ctx
= event
->ctx
;
1971 raw_spin_lock_irq(&ctx
->lock
);
1972 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1973 raw_spin_unlock_irq(&ctx
->lock
);
1976 raw_spin_unlock_irq(&ctx
->lock
);
1978 event_function_call(event
, __perf_event_disable
, NULL
);
1981 void perf_event_disable_local(struct perf_event
*event
)
1983 event_function_local(event
, __perf_event_disable
, NULL
);
1987 * Strictly speaking kernel users cannot create groups and therefore this
1988 * interface does not need the perf_event_ctx_lock() magic.
1990 void perf_event_disable(struct perf_event
*event
)
1992 struct perf_event_context
*ctx
;
1994 ctx
= perf_event_ctx_lock(event
);
1995 _perf_event_disable(event
);
1996 perf_event_ctx_unlock(event
, ctx
);
1998 EXPORT_SYMBOL_GPL(perf_event_disable
);
2000 void perf_event_disable_inatomic(struct perf_event
*event
)
2002 event
->pending_disable
= 1;
2003 irq_work_queue(&event
->pending
);
2006 static void perf_set_shadow_time(struct perf_event
*event
,
2007 struct perf_event_context
*ctx
,
2011 * use the correct time source for the time snapshot
2013 * We could get by without this by leveraging the
2014 * fact that to get to this function, the caller
2015 * has most likely already called update_context_time()
2016 * and update_cgrp_time_xx() and thus both timestamp
2017 * are identical (or very close). Given that tstamp is,
2018 * already adjusted for cgroup, we could say that:
2019 * tstamp - ctx->timestamp
2021 * tstamp - cgrp->timestamp.
2023 * Then, in perf_output_read(), the calculation would
2024 * work with no changes because:
2025 * - event is guaranteed scheduled in
2026 * - no scheduled out in between
2027 * - thus the timestamp would be the same
2029 * But this is a bit hairy.
2031 * So instead, we have an explicit cgroup call to remain
2032 * within the time time source all along. We believe it
2033 * is cleaner and simpler to understand.
2035 if (is_cgroup_event(event
))
2036 perf_cgroup_set_shadow_time(event
, tstamp
);
2038 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
2041 #define MAX_INTERRUPTS (~0ULL)
2043 static void perf_log_throttle(struct perf_event
*event
, int enable
);
2044 static void perf_log_itrace_start(struct perf_event
*event
);
2047 event_sched_in(struct perf_event
*event
,
2048 struct perf_cpu_context
*cpuctx
,
2049 struct perf_event_context
*ctx
)
2051 u64 tstamp
= perf_event_time(event
);
2054 lockdep_assert_held(&ctx
->lock
);
2056 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2059 WRITE_ONCE(event
->oncpu
, smp_processor_id());
2061 * Order event::oncpu write to happen before the ACTIVE state
2065 WRITE_ONCE(event
->state
, PERF_EVENT_STATE_ACTIVE
);
2068 * Unthrottle events, since we scheduled we might have missed several
2069 * ticks already, also for a heavily scheduling task there is little
2070 * guarantee it'll get a tick in a timely manner.
2072 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
2073 perf_log_throttle(event
, 1);
2074 event
->hw
.interrupts
= 0;
2078 * The new state must be visible before we turn it on in the hardware:
2082 perf_pmu_disable(event
->pmu
);
2084 perf_set_shadow_time(event
, ctx
, tstamp
);
2086 perf_log_itrace_start(event
);
2088 if (event
->pmu
->add(event
, PERF_EF_START
)) {
2089 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2095 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
2097 if (!is_software_event(event
))
2098 cpuctx
->active_oncpu
++;
2099 if (!ctx
->nr_active
++)
2100 perf_event_ctx_activate(ctx
);
2101 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
2104 if (event
->attr
.exclusive
)
2105 cpuctx
->exclusive
= 1;
2108 perf_pmu_enable(event
->pmu
);
2114 group_sched_in(struct perf_event
*group_event
,
2115 struct perf_cpu_context
*cpuctx
,
2116 struct perf_event_context
*ctx
)
2118 struct perf_event
*event
, *partial_group
= NULL
;
2119 struct pmu
*pmu
= ctx
->pmu
;
2120 u64 now
= ctx
->time
;
2121 bool simulate
= false;
2123 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
2126 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
2128 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
2129 pmu
->cancel_txn(pmu
);
2130 perf_mux_hrtimer_restart(cpuctx
);
2135 * Schedule in siblings as one group (if any):
2137 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2138 if (event_sched_in(event
, cpuctx
, ctx
)) {
2139 partial_group
= event
;
2144 if (!pmu
->commit_txn(pmu
))
2149 * Groups can be scheduled in as one unit only, so undo any
2150 * partial group before returning:
2151 * The events up to the failed event are scheduled out normally,
2152 * tstamp_stopped will be updated.
2154 * The failed events and the remaining siblings need to have
2155 * their timings updated as if they had gone thru event_sched_in()
2156 * and event_sched_out(). This is required to get consistent timings
2157 * across the group. This also takes care of the case where the group
2158 * could never be scheduled by ensuring tstamp_stopped is set to mark
2159 * the time the event was actually stopped, such that time delta
2160 * calculation in update_event_times() is correct.
2162 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
2163 if (event
== partial_group
)
2167 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
2168 event
->tstamp_stopped
= now
;
2170 event_sched_out(event
, cpuctx
, ctx
);
2173 event_sched_out(group_event
, cpuctx
, ctx
);
2175 pmu
->cancel_txn(pmu
);
2177 perf_mux_hrtimer_restart(cpuctx
);
2183 * Work out whether we can put this event group on the CPU now.
2185 static int group_can_go_on(struct perf_event
*event
,
2186 struct perf_cpu_context
*cpuctx
,
2190 * Groups consisting entirely of software events can always go on.
2192 if (event
->group_caps
& PERF_EV_CAP_SOFTWARE
)
2195 * If an exclusive group is already on, no other hardware
2198 if (cpuctx
->exclusive
)
2201 * If this group is exclusive and there are already
2202 * events on the CPU, it can't go on.
2204 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2207 * Otherwise, try to add it if all previous groups were able
2213 static void add_event_to_ctx(struct perf_event
*event
,
2214 struct perf_event_context
*ctx
)
2216 u64 tstamp
= perf_event_time(event
);
2218 list_add_event(event
, ctx
);
2219 perf_group_attach(event
);
2220 event
->tstamp_enabled
= tstamp
;
2221 event
->tstamp_running
= tstamp
;
2222 event
->tstamp_stopped
= tstamp
;
2225 static void ctx_sched_out(struct perf_event_context
*ctx
,
2226 struct perf_cpu_context
*cpuctx
,
2227 enum event_type_t event_type
);
2229 ctx_sched_in(struct perf_event_context
*ctx
,
2230 struct perf_cpu_context
*cpuctx
,
2231 enum event_type_t event_type
,
2232 struct task_struct
*task
);
2234 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2235 struct perf_event_context
*ctx
,
2236 enum event_type_t event_type
)
2238 if (!cpuctx
->task_ctx
)
2241 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2244 ctx_sched_out(ctx
, cpuctx
, event_type
);
2247 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2248 struct perf_event_context
*ctx
,
2249 struct task_struct
*task
)
2251 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2253 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2254 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2256 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2260 * We want to maintain the following priority of scheduling:
2261 * - CPU pinned (EVENT_CPU | EVENT_PINNED)
2262 * - task pinned (EVENT_PINNED)
2263 * - CPU flexible (EVENT_CPU | EVENT_FLEXIBLE)
2264 * - task flexible (EVENT_FLEXIBLE).
2266 * In order to avoid unscheduling and scheduling back in everything every
2267 * time an event is added, only do it for the groups of equal priority and
2270 * This can be called after a batch operation on task events, in which case
2271 * event_type is a bit mask of the types of events involved. For CPU events,
2272 * event_type is only either EVENT_PINNED or EVENT_FLEXIBLE.
2274 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2275 struct perf_event_context
*task_ctx
,
2276 enum event_type_t event_type
)
2278 enum event_type_t ctx_event_type
= event_type
& EVENT_ALL
;
2279 bool cpu_event
= !!(event_type
& EVENT_CPU
);
2282 * If pinned groups are involved, flexible groups also need to be
2285 if (event_type
& EVENT_PINNED
)
2286 event_type
|= EVENT_FLEXIBLE
;
2288 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2290 task_ctx_sched_out(cpuctx
, task_ctx
, event_type
);
2293 * Decide which cpu ctx groups to schedule out based on the types
2294 * of events that caused rescheduling:
2295 * - EVENT_CPU: schedule out corresponding groups;
2296 * - EVENT_PINNED task events: schedule out EVENT_FLEXIBLE groups;
2297 * - otherwise, do nothing more.
2300 cpu_ctx_sched_out(cpuctx
, ctx_event_type
);
2301 else if (ctx_event_type
& EVENT_PINNED
)
2302 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2304 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2305 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2309 * Cross CPU call to install and enable a performance event
2311 * Very similar to remote_function() + event_function() but cannot assume that
2312 * things like ctx->is_active and cpuctx->task_ctx are set.
2314 static int __perf_install_in_context(void *info
)
2316 struct perf_event
*event
= info
;
2317 struct perf_event_context
*ctx
= event
->ctx
;
2318 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2319 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2320 bool reprogram
= true;
2323 raw_spin_lock(&cpuctx
->ctx
.lock
);
2325 raw_spin_lock(&ctx
->lock
);
2328 reprogram
= (ctx
->task
== current
);
2331 * If the task is running, it must be running on this CPU,
2332 * otherwise we cannot reprogram things.
2334 * If its not running, we don't care, ctx->lock will
2335 * serialize against it becoming runnable.
2337 if (task_curr(ctx
->task
) && !reprogram
) {
2342 WARN_ON_ONCE(reprogram
&& cpuctx
->task_ctx
&& cpuctx
->task_ctx
!= ctx
);
2343 } else if (task_ctx
) {
2344 raw_spin_lock(&task_ctx
->lock
);
2348 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2349 add_event_to_ctx(event
, ctx
);
2350 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2352 add_event_to_ctx(event
, ctx
);
2356 perf_ctx_unlock(cpuctx
, task_ctx
);
2362 * Attach a performance event to a context.
2364 * Very similar to event_function_call, see comment there.
2367 perf_install_in_context(struct perf_event_context
*ctx
,
2368 struct perf_event
*event
,
2371 struct task_struct
*task
= READ_ONCE(ctx
->task
);
2373 lockdep_assert_held(&ctx
->mutex
);
2375 if (event
->cpu
!= -1)
2379 * Ensures that if we can observe event->ctx, both the event and ctx
2380 * will be 'complete'. See perf_iterate_sb_cpu().
2382 smp_store_release(&event
->ctx
, ctx
);
2385 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2390 * Should not happen, we validate the ctx is still alive before calling.
2392 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
))
2396 * Installing events is tricky because we cannot rely on ctx->is_active
2397 * to be set in case this is the nr_events 0 -> 1 transition.
2399 * Instead we use task_curr(), which tells us if the task is running.
2400 * However, since we use task_curr() outside of rq::lock, we can race
2401 * against the actual state. This means the result can be wrong.
2403 * If we get a false positive, we retry, this is harmless.
2405 * If we get a false negative, things are complicated. If we are after
2406 * perf_event_context_sched_in() ctx::lock will serialize us, and the
2407 * value must be correct. If we're before, it doesn't matter since
2408 * perf_event_context_sched_in() will program the counter.
2410 * However, this hinges on the remote context switch having observed
2411 * our task->perf_event_ctxp[] store, such that it will in fact take
2412 * ctx::lock in perf_event_context_sched_in().
2414 * We do this by task_function_call(), if the IPI fails to hit the task
2415 * we know any future context switch of task must see the
2416 * perf_event_ctpx[] store.
2420 * This smp_mb() orders the task->perf_event_ctxp[] store with the
2421 * task_cpu() load, such that if the IPI then does not find the task
2422 * running, a future context switch of that task must observe the
2427 if (!task_function_call(task
, __perf_install_in_context
, event
))
2430 raw_spin_lock_irq(&ctx
->lock
);
2432 if (WARN_ON_ONCE(task
== TASK_TOMBSTONE
)) {
2434 * Cannot happen because we already checked above (which also
2435 * cannot happen), and we hold ctx->mutex, which serializes us
2436 * against perf_event_exit_task_context().
2438 raw_spin_unlock_irq(&ctx
->lock
);
2442 * If the task is not running, ctx->lock will avoid it becoming so,
2443 * thus we can safely install the event.
2445 if (task_curr(task
)) {
2446 raw_spin_unlock_irq(&ctx
->lock
);
2449 add_event_to_ctx(event
, ctx
);
2450 raw_spin_unlock_irq(&ctx
->lock
);
2454 * Put a event into inactive state and update time fields.
2455 * Enabling the leader of a group effectively enables all
2456 * the group members that aren't explicitly disabled, so we
2457 * have to update their ->tstamp_enabled also.
2458 * Note: this works for group members as well as group leaders
2459 * since the non-leader members' sibling_lists will be empty.
2461 static void __perf_event_mark_enabled(struct perf_event
*event
)
2463 struct perf_event
*sub
;
2464 u64 tstamp
= perf_event_time(event
);
2466 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2467 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2468 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2469 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2470 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2475 * Cross CPU call to enable a performance event
2477 static void __perf_event_enable(struct perf_event
*event
,
2478 struct perf_cpu_context
*cpuctx
,
2479 struct perf_event_context
*ctx
,
2482 struct perf_event
*leader
= event
->group_leader
;
2483 struct perf_event_context
*task_ctx
;
2485 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2486 event
->state
<= PERF_EVENT_STATE_ERROR
)
2490 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
2492 __perf_event_mark_enabled(event
);
2494 if (!ctx
->is_active
)
2497 if (!event_filter_match(event
)) {
2498 if (is_cgroup_event(event
))
2499 perf_cgroup_defer_enabled(event
);
2500 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2505 * If the event is in a group and isn't the group leader,
2506 * then don't put it on unless the group is on.
2508 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
) {
2509 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
2513 task_ctx
= cpuctx
->task_ctx
;
2515 WARN_ON_ONCE(task_ctx
!= ctx
);
2517 ctx_resched(cpuctx
, task_ctx
, get_event_type(event
));
2523 * If event->ctx is a cloned context, callers must make sure that
2524 * every task struct that event->ctx->task could possibly point to
2525 * remains valid. This condition is satisfied when called through
2526 * perf_event_for_each_child or perf_event_for_each as described
2527 * for perf_event_disable.
2529 static void _perf_event_enable(struct perf_event
*event
)
2531 struct perf_event_context
*ctx
= event
->ctx
;
2533 raw_spin_lock_irq(&ctx
->lock
);
2534 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
||
2535 event
->state
< PERF_EVENT_STATE_ERROR
) {
2536 raw_spin_unlock_irq(&ctx
->lock
);
2541 * If the event is in error state, clear that first.
2543 * That way, if we see the event in error state below, we know that it
2544 * has gone back into error state, as distinct from the task having
2545 * been scheduled away before the cross-call arrived.
2547 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2548 event
->state
= PERF_EVENT_STATE_OFF
;
2549 raw_spin_unlock_irq(&ctx
->lock
);
2551 event_function_call(event
, __perf_event_enable
, NULL
);
2555 * See perf_event_disable();
2557 void perf_event_enable(struct perf_event
*event
)
2559 struct perf_event_context
*ctx
;
2561 ctx
= perf_event_ctx_lock(event
);
2562 _perf_event_enable(event
);
2563 perf_event_ctx_unlock(event
, ctx
);
2565 EXPORT_SYMBOL_GPL(perf_event_enable
);
2567 struct stop_event_data
{
2568 struct perf_event
*event
;
2569 unsigned int restart
;
2572 static int __perf_event_stop(void *info
)
2574 struct stop_event_data
*sd
= info
;
2575 struct perf_event
*event
= sd
->event
;
2577 /* if it's already INACTIVE, do nothing */
2578 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2581 /* matches smp_wmb() in event_sched_in() */
2585 * There is a window with interrupts enabled before we get here,
2586 * so we need to check again lest we try to stop another CPU's event.
2588 if (READ_ONCE(event
->oncpu
) != smp_processor_id())
2591 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2594 * May race with the actual stop (through perf_pmu_output_stop()),
2595 * but it is only used for events with AUX ring buffer, and such
2596 * events will refuse to restart because of rb::aux_mmap_count==0,
2597 * see comments in perf_aux_output_begin().
2599 * Since this is happening on a event-local CPU, no trace is lost
2603 event
->pmu
->start(event
, 0);
2608 static int perf_event_stop(struct perf_event
*event
, int restart
)
2610 struct stop_event_data sd
= {
2617 if (READ_ONCE(event
->state
) != PERF_EVENT_STATE_ACTIVE
)
2620 /* matches smp_wmb() in event_sched_in() */
2624 * We only want to restart ACTIVE events, so if the event goes
2625 * inactive here (event->oncpu==-1), there's nothing more to do;
2626 * fall through with ret==-ENXIO.
2628 ret
= cpu_function_call(READ_ONCE(event
->oncpu
),
2629 __perf_event_stop
, &sd
);
2630 } while (ret
== -EAGAIN
);
2636 * In order to contain the amount of racy and tricky in the address filter
2637 * configuration management, it is a two part process:
2639 * (p1) when userspace mappings change as a result of (1) or (2) or (3) below,
2640 * we update the addresses of corresponding vmas in
2641 * event::addr_filters_offs array and bump the event::addr_filters_gen;
2642 * (p2) when an event is scheduled in (pmu::add), it calls
2643 * perf_event_addr_filters_sync() which calls pmu::addr_filters_sync()
2644 * if the generation has changed since the previous call.
2646 * If (p1) happens while the event is active, we restart it to force (p2).
2648 * (1) perf_addr_filters_apply(): adjusting filters' offsets based on
2649 * pre-existing mappings, called once when new filters arrive via SET_FILTER
2651 * (2) perf_addr_filters_adjust(): adjusting filters' offsets based on newly
2652 * registered mapping, called for every new mmap(), with mm::mmap_sem down
2654 * (3) perf_event_addr_filters_exec(): clearing filters' offsets in the process
2657 void perf_event_addr_filters_sync(struct perf_event
*event
)
2659 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
2661 if (!has_addr_filter(event
))
2664 raw_spin_lock(&ifh
->lock
);
2665 if (event
->addr_filters_gen
!= event
->hw
.addr_filters_gen
) {
2666 event
->pmu
->addr_filters_sync(event
);
2667 event
->hw
.addr_filters_gen
= event
->addr_filters_gen
;
2669 raw_spin_unlock(&ifh
->lock
);
2671 EXPORT_SYMBOL_GPL(perf_event_addr_filters_sync
);
2673 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2676 * not supported on inherited events
2678 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2681 atomic_add(refresh
, &event
->event_limit
);
2682 _perf_event_enable(event
);
2688 * See perf_event_disable()
2690 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2692 struct perf_event_context
*ctx
;
2695 ctx
= perf_event_ctx_lock(event
);
2696 ret
= _perf_event_refresh(event
, refresh
);
2697 perf_event_ctx_unlock(event
, ctx
);
2701 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2703 static void ctx_sched_out(struct perf_event_context
*ctx
,
2704 struct perf_cpu_context
*cpuctx
,
2705 enum event_type_t event_type
)
2707 int is_active
= ctx
->is_active
;
2708 struct perf_event
*event
;
2710 lockdep_assert_held(&ctx
->lock
);
2712 if (likely(!ctx
->nr_events
)) {
2714 * See __perf_remove_from_context().
2716 WARN_ON_ONCE(ctx
->is_active
);
2718 WARN_ON_ONCE(cpuctx
->task_ctx
);
2722 ctx
->is_active
&= ~event_type
;
2723 if (!(ctx
->is_active
& EVENT_ALL
))
2727 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2728 if (!ctx
->is_active
)
2729 cpuctx
->task_ctx
= NULL
;
2733 * Always update time if it was set; not only when it changes.
2734 * Otherwise we can 'forget' to update time for any but the last
2735 * context we sched out. For example:
2737 * ctx_sched_out(.event_type = EVENT_FLEXIBLE)
2738 * ctx_sched_out(.event_type = EVENT_PINNED)
2740 * would only update time for the pinned events.
2742 if (is_active
& EVENT_TIME
) {
2743 /* update (and stop) ctx time */
2744 update_context_time(ctx
);
2745 update_cgrp_time_from_cpuctx(cpuctx
);
2748 is_active
^= ctx
->is_active
; /* changed bits */
2750 if (!ctx
->nr_active
|| !(is_active
& EVENT_ALL
))
2753 perf_pmu_disable(ctx
->pmu
);
2754 if (is_active
& EVENT_PINNED
) {
2755 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2756 group_sched_out(event
, cpuctx
, ctx
);
2759 if (is_active
& EVENT_FLEXIBLE
) {
2760 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2761 group_sched_out(event
, cpuctx
, ctx
);
2763 perf_pmu_enable(ctx
->pmu
);
2767 * Test whether two contexts are equivalent, i.e. whether they have both been
2768 * cloned from the same version of the same context.
2770 * Equivalence is measured using a generation number in the context that is
2771 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2772 * and list_del_event().
2774 static int context_equiv(struct perf_event_context
*ctx1
,
2775 struct perf_event_context
*ctx2
)
2777 lockdep_assert_held(&ctx1
->lock
);
2778 lockdep_assert_held(&ctx2
->lock
);
2780 /* Pinning disables the swap optimization */
2781 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2784 /* If ctx1 is the parent of ctx2 */
2785 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2788 /* If ctx2 is the parent of ctx1 */
2789 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2793 * If ctx1 and ctx2 have the same parent; we flatten the parent
2794 * hierarchy, see perf_event_init_context().
2796 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2797 ctx1
->parent_gen
== ctx2
->parent_gen
)
2804 static void __perf_event_sync_stat(struct perf_event
*event
,
2805 struct perf_event
*next_event
)
2809 if (!event
->attr
.inherit_stat
)
2813 * Update the event value, we cannot use perf_event_read()
2814 * because we're in the middle of a context switch and have IRQs
2815 * disabled, which upsets smp_call_function_single(), however
2816 * we know the event must be on the current CPU, therefore we
2817 * don't need to use it.
2819 switch (event
->state
) {
2820 case PERF_EVENT_STATE_ACTIVE
:
2821 event
->pmu
->read(event
);
2824 case PERF_EVENT_STATE_INACTIVE
:
2825 update_event_times(event
);
2833 * In order to keep per-task stats reliable we need to flip the event
2834 * values when we flip the contexts.
2836 value
= local64_read(&next_event
->count
);
2837 value
= local64_xchg(&event
->count
, value
);
2838 local64_set(&next_event
->count
, value
);
2840 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2841 swap(event
->total_time_running
, next_event
->total_time_running
);
2844 * Since we swizzled the values, update the user visible data too.
2846 perf_event_update_userpage(event
);
2847 perf_event_update_userpage(next_event
);
2850 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2851 struct perf_event_context
*next_ctx
)
2853 struct perf_event
*event
, *next_event
;
2858 update_context_time(ctx
);
2860 event
= list_first_entry(&ctx
->event_list
,
2861 struct perf_event
, event_entry
);
2863 next_event
= list_first_entry(&next_ctx
->event_list
,
2864 struct perf_event
, event_entry
);
2866 while (&event
->event_entry
!= &ctx
->event_list
&&
2867 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2869 __perf_event_sync_stat(event
, next_event
);
2871 event
= list_next_entry(event
, event_entry
);
2872 next_event
= list_next_entry(next_event
, event_entry
);
2876 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2877 struct task_struct
*next
)
2879 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2880 struct perf_event_context
*next_ctx
;
2881 struct perf_event_context
*parent
, *next_parent
;
2882 struct perf_cpu_context
*cpuctx
;
2888 cpuctx
= __get_cpu_context(ctx
);
2889 if (!cpuctx
->task_ctx
)
2893 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2897 parent
= rcu_dereference(ctx
->parent_ctx
);
2898 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2900 /* If neither context have a parent context; they cannot be clones. */
2901 if (!parent
&& !next_parent
)
2904 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2906 * Looks like the two contexts are clones, so we might be
2907 * able to optimize the context switch. We lock both
2908 * contexts and check that they are clones under the
2909 * lock (including re-checking that neither has been
2910 * uncloned in the meantime). It doesn't matter which
2911 * order we take the locks because no other cpu could
2912 * be trying to lock both of these tasks.
2914 raw_spin_lock(&ctx
->lock
);
2915 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2916 if (context_equiv(ctx
, next_ctx
)) {
2917 WRITE_ONCE(ctx
->task
, next
);
2918 WRITE_ONCE(next_ctx
->task
, task
);
2920 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2923 * RCU_INIT_POINTER here is safe because we've not
2924 * modified the ctx and the above modification of
2925 * ctx->task and ctx->task_ctx_data are immaterial
2926 * since those values are always verified under
2927 * ctx->lock which we're now holding.
2929 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], next_ctx
);
2930 RCU_INIT_POINTER(next
->perf_event_ctxp
[ctxn
], ctx
);
2934 perf_event_sync_stat(ctx
, next_ctx
);
2936 raw_spin_unlock(&next_ctx
->lock
);
2937 raw_spin_unlock(&ctx
->lock
);
2943 raw_spin_lock(&ctx
->lock
);
2944 task_ctx_sched_out(cpuctx
, ctx
, EVENT_ALL
);
2945 raw_spin_unlock(&ctx
->lock
);
2949 static DEFINE_PER_CPU(struct list_head
, sched_cb_list
);
2951 void perf_sched_cb_dec(struct pmu
*pmu
)
2953 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2955 this_cpu_dec(perf_sched_cb_usages
);
2957 if (!--cpuctx
->sched_cb_usage
)
2958 list_del(&cpuctx
->sched_cb_entry
);
2962 void perf_sched_cb_inc(struct pmu
*pmu
)
2964 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2966 if (!cpuctx
->sched_cb_usage
++)
2967 list_add(&cpuctx
->sched_cb_entry
, this_cpu_ptr(&sched_cb_list
));
2969 this_cpu_inc(perf_sched_cb_usages
);
2973 * This function provides the context switch callback to the lower code
2974 * layer. It is invoked ONLY when the context switch callback is enabled.
2976 * This callback is relevant even to per-cpu events; for example multi event
2977 * PEBS requires this to provide PID/TID information. This requires we flush
2978 * all queued PEBS records before we context switch to a new task.
2980 static void perf_pmu_sched_task(struct task_struct
*prev
,
2981 struct task_struct
*next
,
2984 struct perf_cpu_context
*cpuctx
;
2990 list_for_each_entry(cpuctx
, this_cpu_ptr(&sched_cb_list
), sched_cb_entry
) {
2991 pmu
= cpuctx
->ctx
.pmu
; /* software PMUs will not have sched_task */
2993 if (WARN_ON_ONCE(!pmu
->sched_task
))
2996 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2997 perf_pmu_disable(pmu
);
2999 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
3001 perf_pmu_enable(pmu
);
3002 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3006 static void perf_event_switch(struct task_struct
*task
,
3007 struct task_struct
*next_prev
, bool sched_in
);
3009 #define for_each_task_context_nr(ctxn) \
3010 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
3013 * Called from scheduler to remove the events of the current task,
3014 * with interrupts disabled.
3016 * We stop each event and update the event value in event->count.
3018 * This does not protect us against NMI, but disable()
3019 * sets the disabled bit in the control field of event _before_
3020 * accessing the event control register. If a NMI hits, then it will
3021 * not restart the event.
3023 void __perf_event_task_sched_out(struct task_struct
*task
,
3024 struct task_struct
*next
)
3028 if (__this_cpu_read(perf_sched_cb_usages
))
3029 perf_pmu_sched_task(task
, next
, false);
3031 if (atomic_read(&nr_switch_events
))
3032 perf_event_switch(task
, next
, false);
3034 for_each_task_context_nr(ctxn
)
3035 perf_event_context_sched_out(task
, ctxn
, next
);
3038 * if cgroup events exist on this CPU, then we need
3039 * to check if we have to switch out PMU state.
3040 * cgroup event are system-wide mode only
3042 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3043 perf_cgroup_sched_out(task
, next
);
3047 * Called with IRQs disabled
3049 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
3050 enum event_type_t event_type
)
3052 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
3056 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
3057 struct perf_cpu_context
*cpuctx
)
3059 struct perf_event
*event
;
3061 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
3062 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3064 if (!event_filter_match(event
))
3067 /* may need to reset tstamp_enabled */
3068 if (is_cgroup_event(event
))
3069 perf_cgroup_mark_enabled(event
, ctx
);
3071 if (group_can_go_on(event
, cpuctx
, 1))
3072 group_sched_in(event
, cpuctx
, ctx
);
3075 * If this pinned group hasn't been scheduled,
3076 * put it in error state.
3078 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3079 update_group_times(event
);
3080 event
->state
= PERF_EVENT_STATE_ERROR
;
3086 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
3087 struct perf_cpu_context
*cpuctx
)
3089 struct perf_event
*event
;
3092 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
3093 /* Ignore events in OFF or ERROR state */
3094 if (event
->state
<= PERF_EVENT_STATE_OFF
)
3097 * Listen to the 'cpu' scheduling filter constraint
3100 if (!event_filter_match(event
))
3103 /* may need to reset tstamp_enabled */
3104 if (is_cgroup_event(event
))
3105 perf_cgroup_mark_enabled(event
, ctx
);
3107 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
3108 if (group_sched_in(event
, cpuctx
, ctx
))
3115 ctx_sched_in(struct perf_event_context
*ctx
,
3116 struct perf_cpu_context
*cpuctx
,
3117 enum event_type_t event_type
,
3118 struct task_struct
*task
)
3120 int is_active
= ctx
->is_active
;
3123 lockdep_assert_held(&ctx
->lock
);
3125 if (likely(!ctx
->nr_events
))
3128 ctx
->is_active
|= (event_type
| EVENT_TIME
);
3131 cpuctx
->task_ctx
= ctx
;
3133 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
3136 is_active
^= ctx
->is_active
; /* changed bits */
3138 if (is_active
& EVENT_TIME
) {
3139 /* start ctx time */
3141 ctx
->timestamp
= now
;
3142 perf_cgroup_set_timestamp(task
, ctx
);
3146 * First go through the list and put on any pinned groups
3147 * in order to give them the best chance of going on.
3149 if (is_active
& EVENT_PINNED
)
3150 ctx_pinned_sched_in(ctx
, cpuctx
);
3152 /* Then walk through the lower prio flexible groups */
3153 if (is_active
& EVENT_FLEXIBLE
)
3154 ctx_flexible_sched_in(ctx
, cpuctx
);
3157 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
3158 enum event_type_t event_type
,
3159 struct task_struct
*task
)
3161 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
3163 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
3166 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
3167 struct task_struct
*task
)
3169 struct perf_cpu_context
*cpuctx
;
3171 cpuctx
= __get_cpu_context(ctx
);
3172 if (cpuctx
->task_ctx
== ctx
)
3175 perf_ctx_lock(cpuctx
, ctx
);
3176 perf_pmu_disable(ctx
->pmu
);
3178 * We want to keep the following priority order:
3179 * cpu pinned (that don't need to move), task pinned,
3180 * cpu flexible, task flexible.
3182 * However, if task's ctx is not carrying any pinned
3183 * events, no need to flip the cpuctx's events around.
3185 if (!list_empty(&ctx
->pinned_groups
))
3186 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3187 perf_event_sched_in(cpuctx
, ctx
, task
);
3188 perf_pmu_enable(ctx
->pmu
);
3189 perf_ctx_unlock(cpuctx
, ctx
);
3193 * Called from scheduler to add the events of the current task
3194 * with interrupts disabled.
3196 * We restore the event value and then enable it.
3198 * This does not protect us against NMI, but enable()
3199 * sets the enabled bit in the control field of event _before_
3200 * accessing the event control register. If a NMI hits, then it will
3201 * keep the event running.
3203 void __perf_event_task_sched_in(struct task_struct
*prev
,
3204 struct task_struct
*task
)
3206 struct perf_event_context
*ctx
;
3210 * If cgroup events exist on this CPU, then we need to check if we have
3211 * to switch in PMU state; cgroup event are system-wide mode only.
3213 * Since cgroup events are CPU events, we must schedule these in before
3214 * we schedule in the task events.
3216 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
3217 perf_cgroup_sched_in(prev
, task
);
3219 for_each_task_context_nr(ctxn
) {
3220 ctx
= task
->perf_event_ctxp
[ctxn
];
3224 perf_event_context_sched_in(ctx
, task
);
3227 if (atomic_read(&nr_switch_events
))
3228 perf_event_switch(task
, prev
, true);
3230 if (__this_cpu_read(perf_sched_cb_usages
))
3231 perf_pmu_sched_task(prev
, task
, true);
3234 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
3236 u64 frequency
= event
->attr
.sample_freq
;
3237 u64 sec
= NSEC_PER_SEC
;
3238 u64 divisor
, dividend
;
3240 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
3242 count_fls
= fls64(count
);
3243 nsec_fls
= fls64(nsec
);
3244 frequency_fls
= fls64(frequency
);
3248 * We got @count in @nsec, with a target of sample_freq HZ
3249 * the target period becomes:
3252 * period = -------------------
3253 * @nsec * sample_freq
3258 * Reduce accuracy by one bit such that @a and @b converge
3259 * to a similar magnitude.
3261 #define REDUCE_FLS(a, b) \
3263 if (a##_fls > b##_fls) { \
3273 * Reduce accuracy until either term fits in a u64, then proceed with
3274 * the other, so that finally we can do a u64/u64 division.
3276 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
3277 REDUCE_FLS(nsec
, frequency
);
3278 REDUCE_FLS(sec
, count
);
3281 if (count_fls
+ sec_fls
> 64) {
3282 divisor
= nsec
* frequency
;
3284 while (count_fls
+ sec_fls
> 64) {
3285 REDUCE_FLS(count
, sec
);
3289 dividend
= count
* sec
;
3291 dividend
= count
* sec
;
3293 while (nsec_fls
+ frequency_fls
> 64) {
3294 REDUCE_FLS(nsec
, frequency
);
3298 divisor
= nsec
* frequency
;
3304 return div64_u64(dividend
, divisor
);
3307 static DEFINE_PER_CPU(int, perf_throttled_count
);
3308 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
3310 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
3312 struct hw_perf_event
*hwc
= &event
->hw
;
3313 s64 period
, sample_period
;
3316 period
= perf_calculate_period(event
, nsec
, count
);
3318 delta
= (s64
)(period
- hwc
->sample_period
);
3319 delta
= (delta
+ 7) / 8; /* low pass filter */
3321 sample_period
= hwc
->sample_period
+ delta
;
3326 hwc
->sample_period
= sample_period
;
3328 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
3330 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3332 local64_set(&hwc
->period_left
, 0);
3335 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3340 * combine freq adjustment with unthrottling to avoid two passes over the
3341 * events. At the same time, make sure, having freq events does not change
3342 * the rate of unthrottling as that would introduce bias.
3344 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
3347 struct perf_event
*event
;
3348 struct hw_perf_event
*hwc
;
3349 u64 now
, period
= TICK_NSEC
;
3353 * only need to iterate over all events iff:
3354 * - context have events in frequency mode (needs freq adjust)
3355 * - there are events to unthrottle on this cpu
3357 if (!(ctx
->nr_freq
|| needs_unthr
))
3360 raw_spin_lock(&ctx
->lock
);
3361 perf_pmu_disable(ctx
->pmu
);
3363 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3364 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3367 if (!event_filter_match(event
))
3370 perf_pmu_disable(event
->pmu
);
3374 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3375 hwc
->interrupts
= 0;
3376 perf_log_throttle(event
, 1);
3377 event
->pmu
->start(event
, 0);
3380 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3384 * stop the event and update event->count
3386 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3388 now
= local64_read(&event
->count
);
3389 delta
= now
- hwc
->freq_count_stamp
;
3390 hwc
->freq_count_stamp
= now
;
3394 * reload only if value has changed
3395 * we have stopped the event so tell that
3396 * to perf_adjust_period() to avoid stopping it
3400 perf_adjust_period(event
, period
, delta
, false);
3402 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3404 perf_pmu_enable(event
->pmu
);
3407 perf_pmu_enable(ctx
->pmu
);
3408 raw_spin_unlock(&ctx
->lock
);
3412 * Round-robin a context's events:
3414 static void rotate_ctx(struct perf_event_context
*ctx
)
3417 * Rotate the first entry last of non-pinned groups. Rotation might be
3418 * disabled by the inheritance code.
3420 if (!ctx
->rotate_disable
)
3421 list_rotate_left(&ctx
->flexible_groups
);
3424 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3426 struct perf_event_context
*ctx
= NULL
;
3429 if (cpuctx
->ctx
.nr_events
) {
3430 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3434 ctx
= cpuctx
->task_ctx
;
3435 if (ctx
&& ctx
->nr_events
) {
3436 if (ctx
->nr_events
!= ctx
->nr_active
)
3443 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3444 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3446 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3448 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3450 rotate_ctx(&cpuctx
->ctx
);
3454 perf_event_sched_in(cpuctx
, ctx
, current
);
3456 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3457 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3463 void perf_event_task_tick(void)
3465 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3466 struct perf_event_context
*ctx
, *tmp
;
3469 WARN_ON(!irqs_disabled());
3471 __this_cpu_inc(perf_throttled_seq
);
3472 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3473 tick_dep_clear_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
3475 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3476 perf_adjust_freq_unthr_context(ctx
, throttled
);
3479 static int event_enable_on_exec(struct perf_event
*event
,
3480 struct perf_event_context
*ctx
)
3482 if (!event
->attr
.enable_on_exec
)
3485 event
->attr
.enable_on_exec
= 0;
3486 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3489 __perf_event_mark_enabled(event
);
3495 * Enable all of a task's events that have been marked enable-on-exec.
3496 * This expects task == current.
3498 static void perf_event_enable_on_exec(int ctxn
)
3500 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3501 enum event_type_t event_type
= 0;
3502 struct perf_cpu_context
*cpuctx
;
3503 struct perf_event
*event
;
3504 unsigned long flags
;
3507 local_irq_save(flags
);
3508 ctx
= current
->perf_event_ctxp
[ctxn
];
3509 if (!ctx
|| !ctx
->nr_events
)
3512 cpuctx
= __get_cpu_context(ctx
);
3513 perf_ctx_lock(cpuctx
, ctx
);
3514 ctx_sched_out(ctx
, cpuctx
, EVENT_TIME
);
3515 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3516 enabled
|= event_enable_on_exec(event
, ctx
);
3517 event_type
|= get_event_type(event
);
3521 * Unclone and reschedule this context if we enabled any event.
3524 clone_ctx
= unclone_ctx(ctx
);
3525 ctx_resched(cpuctx
, ctx
, event_type
);
3527 ctx_sched_in(ctx
, cpuctx
, EVENT_TIME
, current
);
3529 perf_ctx_unlock(cpuctx
, ctx
);
3532 local_irq_restore(flags
);
3538 struct perf_read_data
{
3539 struct perf_event
*event
;
3544 static int __perf_event_read_cpu(struct perf_event
*event
, int event_cpu
)
3546 u16 local_pkg
, event_pkg
;
3548 if (event
->group_caps
& PERF_EV_CAP_READ_ACTIVE_PKG
) {
3549 int local_cpu
= smp_processor_id();
3551 event_pkg
= topology_physical_package_id(event_cpu
);
3552 local_pkg
= topology_physical_package_id(local_cpu
);
3554 if (event_pkg
== local_pkg
)
3562 * Cross CPU call to read the hardware event
3564 static void __perf_event_read(void *info
)
3566 struct perf_read_data
*data
= info
;
3567 struct perf_event
*sub
, *event
= data
->event
;
3568 struct perf_event_context
*ctx
= event
->ctx
;
3569 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3570 struct pmu
*pmu
= event
->pmu
;
3573 * If this is a task context, we need to check whether it is
3574 * the current task context of this cpu. If not it has been
3575 * scheduled out before the smp call arrived. In that case
3576 * event->count would have been updated to a recent sample
3577 * when the event was scheduled out.
3579 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3582 raw_spin_lock(&ctx
->lock
);
3583 if (ctx
->is_active
) {
3584 update_context_time(ctx
);
3585 update_cgrp_time_from_event(event
);
3588 update_event_times(event
);
3589 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3598 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3602 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3603 update_event_times(sub
);
3604 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3606 * Use sibling's PMU rather than @event's since
3607 * sibling could be on different (eg: software) PMU.
3609 sub
->pmu
->read(sub
);
3613 data
->ret
= pmu
->commit_txn(pmu
);
3616 raw_spin_unlock(&ctx
->lock
);
3619 static inline u64
perf_event_count(struct perf_event
*event
)
3621 if (event
->pmu
->count
)
3622 return event
->pmu
->count(event
);
3624 return __perf_event_count(event
);
3628 * NMI-safe method to read a local event, that is an event that
3630 * - either for the current task, or for this CPU
3631 * - does not have inherit set, for inherited task events
3632 * will not be local and we cannot read them atomically
3633 * - must not have a pmu::count method
3635 int perf_event_read_local(struct perf_event
*event
, u64
*value
)
3637 unsigned long flags
;
3641 * Disabling interrupts avoids all counter scheduling (context
3642 * switches, timer based rotation and IPIs).
3644 local_irq_save(flags
);
3647 * It must not be an event with inherit set, we cannot read
3648 * all child counters from atomic context.
3650 if (event
->attr
.inherit
) {
3656 * It must not have a pmu::count method, those are not
3659 if (event
->pmu
->count
) {
3664 /* If this is a per-task event, it must be for current */
3665 if ((event
->attach_state
& PERF_ATTACH_TASK
) &&
3666 event
->hw
.target
!= current
) {
3671 /* If this is a per-CPU event, it must be for this CPU */
3672 if (!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3673 event
->cpu
!= smp_processor_id()) {
3679 * If the event is currently on this CPU, its either a per-task event,
3680 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3683 if (event
->oncpu
== smp_processor_id())
3684 event
->pmu
->read(event
);
3686 *value
= local64_read(&event
->count
);
3688 local_irq_restore(flags
);
3693 static int perf_event_read(struct perf_event
*event
, bool group
)
3695 int event_cpu
, ret
= 0;
3698 * If event is enabled and currently active on a CPU, update the
3699 * value in the event structure:
3701 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3702 struct perf_read_data data
= {
3708 event_cpu
= READ_ONCE(event
->oncpu
);
3709 if ((unsigned)event_cpu
>= nr_cpu_ids
)
3713 event_cpu
= __perf_event_read_cpu(event
, event_cpu
);
3716 * Purposely ignore the smp_call_function_single() return
3719 * If event_cpu isn't a valid CPU it means the event got
3720 * scheduled out and that will have updated the event count.
3722 * Therefore, either way, we'll have an up-to-date event count
3725 (void)smp_call_function_single(event_cpu
, __perf_event_read
, &data
, 1);
3728 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3729 struct perf_event_context
*ctx
= event
->ctx
;
3730 unsigned long flags
;
3732 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3734 * may read while context is not active
3735 * (e.g., thread is blocked), in that case
3736 * we cannot update context time
3738 if (ctx
->is_active
) {
3739 update_context_time(ctx
);
3740 update_cgrp_time_from_event(event
);
3743 update_group_times(event
);
3745 update_event_times(event
);
3746 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3753 * Initialize the perf_event context in a task_struct:
3755 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3757 raw_spin_lock_init(&ctx
->lock
);
3758 mutex_init(&ctx
->mutex
);
3759 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3760 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3761 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3762 INIT_LIST_HEAD(&ctx
->event_list
);
3763 atomic_set(&ctx
->refcount
, 1);
3766 static struct perf_event_context
*
3767 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3769 struct perf_event_context
*ctx
;
3771 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3775 __perf_event_init_context(ctx
);
3778 get_task_struct(task
);
3785 static struct task_struct
*
3786 find_lively_task_by_vpid(pid_t vpid
)
3788 struct task_struct
*task
;
3794 task
= find_task_by_vpid(vpid
);
3796 get_task_struct(task
);
3800 return ERR_PTR(-ESRCH
);
3806 * Returns a matching context with refcount and pincount.
3808 static struct perf_event_context
*
3809 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3810 struct perf_event
*event
)
3812 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3813 struct perf_cpu_context
*cpuctx
;
3814 void *task_ctx_data
= NULL
;
3815 unsigned long flags
;
3817 int cpu
= event
->cpu
;
3820 /* Must be root to operate on a CPU event: */
3821 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3822 return ERR_PTR(-EACCES
);
3824 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3833 ctxn
= pmu
->task_ctx_nr
;
3837 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3838 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3839 if (!task_ctx_data
) {
3846 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3848 clone_ctx
= unclone_ctx(ctx
);
3851 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3852 ctx
->task_ctx_data
= task_ctx_data
;
3853 task_ctx_data
= NULL
;
3855 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3860 ctx
= alloc_perf_context(pmu
, task
);
3865 if (task_ctx_data
) {
3866 ctx
->task_ctx_data
= task_ctx_data
;
3867 task_ctx_data
= NULL
;
3871 mutex_lock(&task
->perf_event_mutex
);
3873 * If it has already passed perf_event_exit_task().
3874 * we must see PF_EXITING, it takes this mutex too.
3876 if (task
->flags
& PF_EXITING
)
3878 else if (task
->perf_event_ctxp
[ctxn
])
3883 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3885 mutex_unlock(&task
->perf_event_mutex
);
3887 if (unlikely(err
)) {
3896 kfree(task_ctx_data
);
3900 kfree(task_ctx_data
);
3901 return ERR_PTR(err
);
3904 static void perf_event_free_filter(struct perf_event
*event
);
3905 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3907 static void free_event_rcu(struct rcu_head
*head
)
3909 struct perf_event
*event
;
3911 event
= container_of(head
, struct perf_event
, rcu_head
);
3913 put_pid_ns(event
->ns
);
3914 perf_event_free_filter(event
);
3918 static void ring_buffer_attach(struct perf_event
*event
,
3919 struct ring_buffer
*rb
);
3921 static void detach_sb_event(struct perf_event
*event
)
3923 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
3925 raw_spin_lock(&pel
->lock
);
3926 list_del_rcu(&event
->sb_list
);
3927 raw_spin_unlock(&pel
->lock
);
3930 static bool is_sb_event(struct perf_event
*event
)
3932 struct perf_event_attr
*attr
= &event
->attr
;
3937 if (event
->attach_state
& PERF_ATTACH_TASK
)
3940 if (attr
->mmap
|| attr
->mmap_data
|| attr
->mmap2
||
3941 attr
->comm
|| attr
->comm_exec
||
3943 attr
->context_switch
)
3948 static void unaccount_pmu_sb_event(struct perf_event
*event
)
3950 if (is_sb_event(event
))
3951 detach_sb_event(event
);
3954 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3959 if (is_cgroup_event(event
))
3960 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3963 #ifdef CONFIG_NO_HZ_FULL
3964 static DEFINE_SPINLOCK(nr_freq_lock
);
3967 static void unaccount_freq_event_nohz(void)
3969 #ifdef CONFIG_NO_HZ_FULL
3970 spin_lock(&nr_freq_lock
);
3971 if (atomic_dec_and_test(&nr_freq_events
))
3972 tick_nohz_dep_clear(TICK_DEP_BIT_PERF_EVENTS
);
3973 spin_unlock(&nr_freq_lock
);
3977 static void unaccount_freq_event(void)
3979 if (tick_nohz_full_enabled())
3980 unaccount_freq_event_nohz();
3982 atomic_dec(&nr_freq_events
);
3985 static void unaccount_event(struct perf_event
*event
)
3992 if (event
->attach_state
& PERF_ATTACH_TASK
)
3994 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3995 atomic_dec(&nr_mmap_events
);
3996 if (event
->attr
.comm
)
3997 atomic_dec(&nr_comm_events
);
3998 if (event
->attr
.namespaces
)
3999 atomic_dec(&nr_namespaces_events
);
4000 if (event
->attr
.task
)
4001 atomic_dec(&nr_task_events
);
4002 if (event
->attr
.freq
)
4003 unaccount_freq_event();
4004 if (event
->attr
.context_switch
) {
4006 atomic_dec(&nr_switch_events
);
4008 if (is_cgroup_event(event
))
4010 if (has_branch_stack(event
))
4014 if (!atomic_add_unless(&perf_sched_count
, -1, 1))
4015 schedule_delayed_work(&perf_sched_work
, HZ
);
4018 unaccount_event_cpu(event
, event
->cpu
);
4020 unaccount_pmu_sb_event(event
);
4023 static void perf_sched_delayed(struct work_struct
*work
)
4025 mutex_lock(&perf_sched_mutex
);
4026 if (atomic_dec_and_test(&perf_sched_count
))
4027 static_branch_disable(&perf_sched_events
);
4028 mutex_unlock(&perf_sched_mutex
);
4032 * The following implement mutual exclusion of events on "exclusive" pmus
4033 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
4034 * at a time, so we disallow creating events that might conflict, namely:
4036 * 1) cpu-wide events in the presence of per-task events,
4037 * 2) per-task events in the presence of cpu-wide events,
4038 * 3) two matching events on the same context.
4040 * The former two cases are handled in the allocation path (perf_event_alloc(),
4041 * _free_event()), the latter -- before the first perf_install_in_context().
4043 static int exclusive_event_init(struct perf_event
*event
)
4045 struct pmu
*pmu
= event
->pmu
;
4047 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4051 * Prevent co-existence of per-task and cpu-wide events on the
4052 * same exclusive pmu.
4054 * Negative pmu::exclusive_cnt means there are cpu-wide
4055 * events on this "exclusive" pmu, positive means there are
4058 * Since this is called in perf_event_alloc() path, event::ctx
4059 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
4060 * to mean "per-task event", because unlike other attach states it
4061 * never gets cleared.
4063 if (event
->attach_state
& PERF_ATTACH_TASK
) {
4064 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
4067 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
4074 static void exclusive_event_destroy(struct perf_event
*event
)
4076 struct pmu
*pmu
= event
->pmu
;
4078 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4081 /* see comment in exclusive_event_init() */
4082 if (event
->attach_state
& PERF_ATTACH_TASK
)
4083 atomic_dec(&pmu
->exclusive_cnt
);
4085 atomic_inc(&pmu
->exclusive_cnt
);
4088 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
4090 if ((e1
->pmu
== e2
->pmu
) &&
4091 (e1
->cpu
== e2
->cpu
||
4098 /* Called under the same ctx::mutex as perf_install_in_context() */
4099 static bool exclusive_event_installable(struct perf_event
*event
,
4100 struct perf_event_context
*ctx
)
4102 struct perf_event
*iter_event
;
4103 struct pmu
*pmu
= event
->pmu
;
4105 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
4108 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
4109 if (exclusive_event_match(iter_event
, event
))
4116 static void perf_addr_filters_splice(struct perf_event
*event
,
4117 struct list_head
*head
);
4119 static void _free_event(struct perf_event
*event
)
4121 irq_work_sync(&event
->pending
);
4123 unaccount_event(event
);
4127 * Can happen when we close an event with re-directed output.
4129 * Since we have a 0 refcount, perf_mmap_close() will skip
4130 * over us; possibly making our ring_buffer_put() the last.
4132 mutex_lock(&event
->mmap_mutex
);
4133 ring_buffer_attach(event
, NULL
);
4134 mutex_unlock(&event
->mmap_mutex
);
4137 if (is_cgroup_event(event
))
4138 perf_detach_cgroup(event
);
4140 if (!event
->parent
) {
4141 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
4142 put_callchain_buffers();
4145 perf_event_free_bpf_prog(event
);
4146 perf_addr_filters_splice(event
, NULL
);
4147 kfree(event
->addr_filters_offs
);
4150 event
->destroy(event
);
4153 put_ctx(event
->ctx
);
4155 exclusive_event_destroy(event
);
4156 module_put(event
->pmu
->module
);
4158 call_rcu(&event
->rcu_head
, free_event_rcu
);
4162 * Used to free events which have a known refcount of 1, such as in error paths
4163 * where the event isn't exposed yet and inherited events.
4165 static void free_event(struct perf_event
*event
)
4167 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
4168 "unexpected event refcount: %ld; ptr=%p\n",
4169 atomic_long_read(&event
->refcount
), event
)) {
4170 /* leak to avoid use-after-free */
4178 * Remove user event from the owner task.
4180 static void perf_remove_from_owner(struct perf_event
*event
)
4182 struct task_struct
*owner
;
4186 * Matches the smp_store_release() in perf_event_exit_task(). If we
4187 * observe !owner it means the list deletion is complete and we can
4188 * indeed free this event, otherwise we need to serialize on
4189 * owner->perf_event_mutex.
4191 owner
= lockless_dereference(event
->owner
);
4194 * Since delayed_put_task_struct() also drops the last
4195 * task reference we can safely take a new reference
4196 * while holding the rcu_read_lock().
4198 get_task_struct(owner
);
4204 * If we're here through perf_event_exit_task() we're already
4205 * holding ctx->mutex which would be an inversion wrt. the
4206 * normal lock order.
4208 * However we can safely take this lock because its the child
4211 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
4214 * We have to re-check the event->owner field, if it is cleared
4215 * we raced with perf_event_exit_task(), acquiring the mutex
4216 * ensured they're done, and we can proceed with freeing the
4220 list_del_init(&event
->owner_entry
);
4221 smp_store_release(&event
->owner
, NULL
);
4223 mutex_unlock(&owner
->perf_event_mutex
);
4224 put_task_struct(owner
);
4228 static void put_event(struct perf_event
*event
)
4230 if (!atomic_long_dec_and_test(&event
->refcount
))
4237 * Kill an event dead; while event:refcount will preserve the event
4238 * object, it will not preserve its functionality. Once the last 'user'
4239 * gives up the object, we'll destroy the thing.
4241 int perf_event_release_kernel(struct perf_event
*event
)
4243 struct perf_event_context
*ctx
= event
->ctx
;
4244 struct perf_event
*child
, *tmp
;
4247 * If we got here through err_file: fput(event_file); we will not have
4248 * attached to a context yet.
4251 WARN_ON_ONCE(event
->attach_state
&
4252 (PERF_ATTACH_CONTEXT
|PERF_ATTACH_GROUP
));
4256 if (!is_kernel_event(event
))
4257 perf_remove_from_owner(event
);
4259 ctx
= perf_event_ctx_lock(event
);
4260 WARN_ON_ONCE(ctx
->parent_ctx
);
4261 perf_remove_from_context(event
, DETACH_GROUP
);
4263 raw_spin_lock_irq(&ctx
->lock
);
4265 * Mark this event as STATE_DEAD, there is no external reference to it
4268 * Anybody acquiring event->child_mutex after the below loop _must_
4269 * also see this, most importantly inherit_event() which will avoid
4270 * placing more children on the list.
4272 * Thus this guarantees that we will in fact observe and kill _ALL_
4275 event
->state
= PERF_EVENT_STATE_DEAD
;
4276 raw_spin_unlock_irq(&ctx
->lock
);
4278 perf_event_ctx_unlock(event
, ctx
);
4281 mutex_lock(&event
->child_mutex
);
4282 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4285 * Cannot change, child events are not migrated, see the
4286 * comment with perf_event_ctx_lock_nested().
4288 ctx
= lockless_dereference(child
->ctx
);
4290 * Since child_mutex nests inside ctx::mutex, we must jump
4291 * through hoops. We start by grabbing a reference on the ctx.
4293 * Since the event cannot get freed while we hold the
4294 * child_mutex, the context must also exist and have a !0
4300 * Now that we have a ctx ref, we can drop child_mutex, and
4301 * acquire ctx::mutex without fear of it going away. Then we
4302 * can re-acquire child_mutex.
4304 mutex_unlock(&event
->child_mutex
);
4305 mutex_lock(&ctx
->mutex
);
4306 mutex_lock(&event
->child_mutex
);
4309 * Now that we hold ctx::mutex and child_mutex, revalidate our
4310 * state, if child is still the first entry, it didn't get freed
4311 * and we can continue doing so.
4313 tmp
= list_first_entry_or_null(&event
->child_list
,
4314 struct perf_event
, child_list
);
4316 perf_remove_from_context(child
, DETACH_GROUP
);
4317 list_del(&child
->child_list
);
4320 * This matches the refcount bump in inherit_event();
4321 * this can't be the last reference.
4326 mutex_unlock(&event
->child_mutex
);
4327 mutex_unlock(&ctx
->mutex
);
4331 mutex_unlock(&event
->child_mutex
);
4334 put_event(event
); /* Must be the 'last' reference */
4337 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
4340 * Called when the last reference to the file is gone.
4342 static int perf_release(struct inode
*inode
, struct file
*file
)
4344 perf_event_release_kernel(file
->private_data
);
4348 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
4350 struct perf_event
*child
;
4356 mutex_lock(&event
->child_mutex
);
4358 (void)perf_event_read(event
, false);
4359 total
+= perf_event_count(event
);
4361 *enabled
+= event
->total_time_enabled
+
4362 atomic64_read(&event
->child_total_time_enabled
);
4363 *running
+= event
->total_time_running
+
4364 atomic64_read(&event
->child_total_time_running
);
4366 list_for_each_entry(child
, &event
->child_list
, child_list
) {
4367 (void)perf_event_read(child
, false);
4368 total
+= perf_event_count(child
);
4369 *enabled
+= child
->total_time_enabled
;
4370 *running
+= child
->total_time_running
;
4372 mutex_unlock(&event
->child_mutex
);
4376 EXPORT_SYMBOL_GPL(perf_event_read_value
);
4378 static int __perf_read_group_add(struct perf_event
*leader
,
4379 u64 read_format
, u64
*values
)
4381 struct perf_event
*sub
;
4382 int n
= 1; /* skip @nr */
4385 ret
= perf_event_read(leader
, true);
4390 * Since we co-schedule groups, {enabled,running} times of siblings
4391 * will be identical to those of the leader, so we only publish one
4394 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4395 values
[n
++] += leader
->total_time_enabled
+
4396 atomic64_read(&leader
->child_total_time_enabled
);
4399 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4400 values
[n
++] += leader
->total_time_running
+
4401 atomic64_read(&leader
->child_total_time_running
);
4405 * Write {count,id} tuples for every sibling.
4407 values
[n
++] += perf_event_count(leader
);
4408 if (read_format
& PERF_FORMAT_ID
)
4409 values
[n
++] = primary_event_id(leader
);
4411 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4412 values
[n
++] += perf_event_count(sub
);
4413 if (read_format
& PERF_FORMAT_ID
)
4414 values
[n
++] = primary_event_id(sub
);
4420 static int perf_read_group(struct perf_event
*event
,
4421 u64 read_format
, char __user
*buf
)
4423 struct perf_event
*leader
= event
->group_leader
, *child
;
4424 struct perf_event_context
*ctx
= leader
->ctx
;
4428 lockdep_assert_held(&ctx
->mutex
);
4430 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
4434 values
[0] = 1 + leader
->nr_siblings
;
4437 * By locking the child_mutex of the leader we effectively
4438 * lock the child list of all siblings.. XXX explain how.
4440 mutex_lock(&leader
->child_mutex
);
4442 ret
= __perf_read_group_add(leader
, read_format
, values
);
4446 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
4447 ret
= __perf_read_group_add(child
, read_format
, values
);
4452 mutex_unlock(&leader
->child_mutex
);
4454 ret
= event
->read_size
;
4455 if (copy_to_user(buf
, values
, event
->read_size
))
4460 mutex_unlock(&leader
->child_mutex
);
4466 static int perf_read_one(struct perf_event
*event
,
4467 u64 read_format
, char __user
*buf
)
4469 u64 enabled
, running
;
4473 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4474 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4475 values
[n
++] = enabled
;
4476 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4477 values
[n
++] = running
;
4478 if (read_format
& PERF_FORMAT_ID
)
4479 values
[n
++] = primary_event_id(event
);
4481 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4484 return n
* sizeof(u64
);
4487 static bool is_event_hup(struct perf_event
*event
)
4491 if (event
->state
> PERF_EVENT_STATE_EXIT
)
4494 mutex_lock(&event
->child_mutex
);
4495 no_children
= list_empty(&event
->child_list
);
4496 mutex_unlock(&event
->child_mutex
);
4501 * Read the performance event - simple non blocking version for now
4504 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4506 u64 read_format
= event
->attr
.read_format
;
4510 * Return end-of-file for a read on a event that is in
4511 * error state (i.e. because it was pinned but it couldn't be
4512 * scheduled on to the CPU at some point).
4514 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4517 if (count
< event
->read_size
)
4520 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4521 if (read_format
& PERF_FORMAT_GROUP
)
4522 ret
= perf_read_group(event
, read_format
, buf
);
4524 ret
= perf_read_one(event
, read_format
, buf
);
4530 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4532 struct perf_event
*event
= file
->private_data
;
4533 struct perf_event_context
*ctx
;
4536 ctx
= perf_event_ctx_lock(event
);
4537 ret
= __perf_read(event
, buf
, count
);
4538 perf_event_ctx_unlock(event
, ctx
);
4543 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4545 struct perf_event
*event
= file
->private_data
;
4546 struct ring_buffer
*rb
;
4547 unsigned int events
= POLLHUP
;
4549 poll_wait(file
, &event
->waitq
, wait
);
4551 if (is_event_hup(event
))
4555 * Pin the event->rb by taking event->mmap_mutex; otherwise
4556 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4558 mutex_lock(&event
->mmap_mutex
);
4561 events
= atomic_xchg(&rb
->poll
, 0);
4562 mutex_unlock(&event
->mmap_mutex
);
4566 static void _perf_event_reset(struct perf_event
*event
)
4568 (void)perf_event_read(event
, false);
4569 local64_set(&event
->count
, 0);
4570 perf_event_update_userpage(event
);
4574 * Holding the top-level event's child_mutex means that any
4575 * descendant process that has inherited this event will block
4576 * in perf_event_exit_event() if it goes to exit, thus satisfying the
4577 * task existence requirements of perf_event_enable/disable.
4579 static void perf_event_for_each_child(struct perf_event
*event
,
4580 void (*func
)(struct perf_event
*))
4582 struct perf_event
*child
;
4584 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4586 mutex_lock(&event
->child_mutex
);
4588 list_for_each_entry(child
, &event
->child_list
, child_list
)
4590 mutex_unlock(&event
->child_mutex
);
4593 static void perf_event_for_each(struct perf_event
*event
,
4594 void (*func
)(struct perf_event
*))
4596 struct perf_event_context
*ctx
= event
->ctx
;
4597 struct perf_event
*sibling
;
4599 lockdep_assert_held(&ctx
->mutex
);
4601 event
= event
->group_leader
;
4603 perf_event_for_each_child(event
, func
);
4604 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4605 perf_event_for_each_child(sibling
, func
);
4608 static void __perf_event_period(struct perf_event
*event
,
4609 struct perf_cpu_context
*cpuctx
,
4610 struct perf_event_context
*ctx
,
4613 u64 value
= *((u64
*)info
);
4616 if (event
->attr
.freq
) {
4617 event
->attr
.sample_freq
= value
;
4619 event
->attr
.sample_period
= value
;
4620 event
->hw
.sample_period
= value
;
4623 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4625 perf_pmu_disable(ctx
->pmu
);
4627 * We could be throttled; unthrottle now to avoid the tick
4628 * trying to unthrottle while we already re-started the event.
4630 if (event
->hw
.interrupts
== MAX_INTERRUPTS
) {
4631 event
->hw
.interrupts
= 0;
4632 perf_log_throttle(event
, 1);
4634 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4637 local64_set(&event
->hw
.period_left
, 0);
4640 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4641 perf_pmu_enable(ctx
->pmu
);
4645 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4649 if (!is_sampling_event(event
))
4652 if (copy_from_user(&value
, arg
, sizeof(value
)))
4658 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4661 event_function_call(event
, __perf_event_period
, &value
);
4666 static const struct file_operations perf_fops
;
4668 static inline int perf_fget_light(int fd
, struct fd
*p
)
4670 struct fd f
= fdget(fd
);
4674 if (f
.file
->f_op
!= &perf_fops
) {
4682 static int perf_event_set_output(struct perf_event
*event
,
4683 struct perf_event
*output_event
);
4684 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4685 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4687 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4689 void (*func
)(struct perf_event
*);
4693 case PERF_EVENT_IOC_ENABLE
:
4694 func
= _perf_event_enable
;
4696 case PERF_EVENT_IOC_DISABLE
:
4697 func
= _perf_event_disable
;
4699 case PERF_EVENT_IOC_RESET
:
4700 func
= _perf_event_reset
;
4703 case PERF_EVENT_IOC_REFRESH
:
4704 return _perf_event_refresh(event
, arg
);
4706 case PERF_EVENT_IOC_PERIOD
:
4707 return perf_event_period(event
, (u64 __user
*)arg
);
4709 case PERF_EVENT_IOC_ID
:
4711 u64 id
= primary_event_id(event
);
4713 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4718 case PERF_EVENT_IOC_SET_OUTPUT
:
4722 struct perf_event
*output_event
;
4724 ret
= perf_fget_light(arg
, &output
);
4727 output_event
= output
.file
->private_data
;
4728 ret
= perf_event_set_output(event
, output_event
);
4731 ret
= perf_event_set_output(event
, NULL
);
4736 case PERF_EVENT_IOC_SET_FILTER
:
4737 return perf_event_set_filter(event
, (void __user
*)arg
);
4739 case PERF_EVENT_IOC_SET_BPF
:
4740 return perf_event_set_bpf_prog(event
, arg
);
4742 case PERF_EVENT_IOC_PAUSE_OUTPUT
: {
4743 struct ring_buffer
*rb
;
4746 rb
= rcu_dereference(event
->rb
);
4747 if (!rb
|| !rb
->nr_pages
) {
4751 rb_toggle_paused(rb
, !!arg
);
4759 if (flags
& PERF_IOC_FLAG_GROUP
)
4760 perf_event_for_each(event
, func
);
4762 perf_event_for_each_child(event
, func
);
4767 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4769 struct perf_event
*event
= file
->private_data
;
4770 struct perf_event_context
*ctx
;
4773 ctx
= perf_event_ctx_lock(event
);
4774 ret
= _perf_ioctl(event
, cmd
, arg
);
4775 perf_event_ctx_unlock(event
, ctx
);
4780 #ifdef CONFIG_COMPAT
4781 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4784 switch (_IOC_NR(cmd
)) {
4785 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4786 case _IOC_NR(PERF_EVENT_IOC_ID
):
4787 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4788 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4789 cmd
&= ~IOCSIZE_MASK
;
4790 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4794 return perf_ioctl(file
, cmd
, arg
);
4797 # define perf_compat_ioctl NULL
4800 int perf_event_task_enable(void)
4802 struct perf_event_context
*ctx
;
4803 struct perf_event
*event
;
4805 mutex_lock(¤t
->perf_event_mutex
);
4806 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4807 ctx
= perf_event_ctx_lock(event
);
4808 perf_event_for_each_child(event
, _perf_event_enable
);
4809 perf_event_ctx_unlock(event
, ctx
);
4811 mutex_unlock(¤t
->perf_event_mutex
);
4816 int perf_event_task_disable(void)
4818 struct perf_event_context
*ctx
;
4819 struct perf_event
*event
;
4821 mutex_lock(¤t
->perf_event_mutex
);
4822 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4823 ctx
= perf_event_ctx_lock(event
);
4824 perf_event_for_each_child(event
, _perf_event_disable
);
4825 perf_event_ctx_unlock(event
, ctx
);
4827 mutex_unlock(¤t
->perf_event_mutex
);
4832 static int perf_event_index(struct perf_event
*event
)
4834 if (event
->hw
.state
& PERF_HES_STOPPED
)
4837 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4840 return event
->pmu
->event_idx(event
);
4843 static void calc_timer_values(struct perf_event
*event
,
4850 *now
= perf_clock();
4851 ctx_time
= event
->shadow_ctx_time
+ *now
;
4852 *enabled
= ctx_time
- event
->tstamp_enabled
;
4853 *running
= ctx_time
- event
->tstamp_running
;
4856 static void perf_event_init_userpage(struct perf_event
*event
)
4858 struct perf_event_mmap_page
*userpg
;
4859 struct ring_buffer
*rb
;
4862 rb
= rcu_dereference(event
->rb
);
4866 userpg
= rb
->user_page
;
4868 /* Allow new userspace to detect that bit 0 is deprecated */
4869 userpg
->cap_bit0_is_deprecated
= 1;
4870 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4871 userpg
->data_offset
= PAGE_SIZE
;
4872 userpg
->data_size
= perf_data_size(rb
);
4878 void __weak
arch_perf_update_userpage(
4879 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4884 * Callers need to ensure there can be no nesting of this function, otherwise
4885 * the seqlock logic goes bad. We can not serialize this because the arch
4886 * code calls this from NMI context.
4888 void perf_event_update_userpage(struct perf_event
*event
)
4890 struct perf_event_mmap_page
*userpg
;
4891 struct ring_buffer
*rb
;
4892 u64 enabled
, running
, now
;
4895 rb
= rcu_dereference(event
->rb
);
4900 * compute total_time_enabled, total_time_running
4901 * based on snapshot values taken when the event
4902 * was last scheduled in.
4904 * we cannot simply called update_context_time()
4905 * because of locking issue as we can be called in
4908 calc_timer_values(event
, &now
, &enabled
, &running
);
4910 userpg
= rb
->user_page
;
4912 * Disable preemption so as to not let the corresponding user-space
4913 * spin too long if we get preempted.
4918 userpg
->index
= perf_event_index(event
);
4919 userpg
->offset
= perf_event_count(event
);
4921 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4923 userpg
->time_enabled
= enabled
+
4924 atomic64_read(&event
->child_total_time_enabled
);
4926 userpg
->time_running
= running
+
4927 atomic64_read(&event
->child_total_time_running
);
4929 arch_perf_update_userpage(event
, userpg
, now
);
4938 static int perf_mmap_fault(struct vm_fault
*vmf
)
4940 struct perf_event
*event
= vmf
->vma
->vm_file
->private_data
;
4941 struct ring_buffer
*rb
;
4942 int ret
= VM_FAULT_SIGBUS
;
4944 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4945 if (vmf
->pgoff
== 0)
4951 rb
= rcu_dereference(event
->rb
);
4955 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4958 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4962 get_page(vmf
->page
);
4963 vmf
->page
->mapping
= vmf
->vma
->vm_file
->f_mapping
;
4964 vmf
->page
->index
= vmf
->pgoff
;
4973 static void ring_buffer_attach(struct perf_event
*event
,
4974 struct ring_buffer
*rb
)
4976 struct ring_buffer
*old_rb
= NULL
;
4977 unsigned long flags
;
4981 * Should be impossible, we set this when removing
4982 * event->rb_entry and wait/clear when adding event->rb_entry.
4984 WARN_ON_ONCE(event
->rcu_pending
);
4987 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4988 list_del_rcu(&event
->rb_entry
);
4989 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4991 event
->rcu_batches
= get_state_synchronize_rcu();
4992 event
->rcu_pending
= 1;
4996 if (event
->rcu_pending
) {
4997 cond_synchronize_rcu(event
->rcu_batches
);
4998 event
->rcu_pending
= 0;
5001 spin_lock_irqsave(&rb
->event_lock
, flags
);
5002 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
5003 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
5007 * Avoid racing with perf_mmap_close(AUX): stop the event
5008 * before swizzling the event::rb pointer; if it's getting
5009 * unmapped, its aux_mmap_count will be 0 and it won't
5010 * restart. See the comment in __perf_pmu_output_stop().
5012 * Data will inevitably be lost when set_output is done in
5013 * mid-air, but then again, whoever does it like this is
5014 * not in for the data anyway.
5017 perf_event_stop(event
, 0);
5019 rcu_assign_pointer(event
->rb
, rb
);
5022 ring_buffer_put(old_rb
);
5024 * Since we detached before setting the new rb, so that we
5025 * could attach the new rb, we could have missed a wakeup.
5028 wake_up_all(&event
->waitq
);
5032 static void ring_buffer_wakeup(struct perf_event
*event
)
5034 struct ring_buffer
*rb
;
5037 rb
= rcu_dereference(event
->rb
);
5039 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
5040 wake_up_all(&event
->waitq
);
5045 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
5047 struct ring_buffer
*rb
;
5050 rb
= rcu_dereference(event
->rb
);
5052 if (!atomic_inc_not_zero(&rb
->refcount
))
5060 void ring_buffer_put(struct ring_buffer
*rb
)
5062 if (!atomic_dec_and_test(&rb
->refcount
))
5065 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
5067 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
5070 static void perf_mmap_open(struct vm_area_struct
*vma
)
5072 struct perf_event
*event
= vma
->vm_file
->private_data
;
5074 atomic_inc(&event
->mmap_count
);
5075 atomic_inc(&event
->rb
->mmap_count
);
5078 atomic_inc(&event
->rb
->aux_mmap_count
);
5080 if (event
->pmu
->event_mapped
)
5081 event
->pmu
->event_mapped(event
);
5084 static void perf_pmu_output_stop(struct perf_event
*event
);
5087 * A buffer can be mmap()ed multiple times; either directly through the same
5088 * event, or through other events by use of perf_event_set_output().
5090 * In order to undo the VM accounting done by perf_mmap() we need to destroy
5091 * the buffer here, where we still have a VM context. This means we need
5092 * to detach all events redirecting to us.
5094 static void perf_mmap_close(struct vm_area_struct
*vma
)
5096 struct perf_event
*event
= vma
->vm_file
->private_data
;
5098 struct ring_buffer
*rb
= ring_buffer_get(event
);
5099 struct user_struct
*mmap_user
= rb
->mmap_user
;
5100 int mmap_locked
= rb
->mmap_locked
;
5101 unsigned long size
= perf_data_size(rb
);
5103 if (event
->pmu
->event_unmapped
)
5104 event
->pmu
->event_unmapped(event
);
5107 * rb->aux_mmap_count will always drop before rb->mmap_count and
5108 * event->mmap_count, so it is ok to use event->mmap_mutex to
5109 * serialize with perf_mmap here.
5111 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
5112 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
5114 * Stop all AUX events that are writing to this buffer,
5115 * so that we can free its AUX pages and corresponding PMU
5116 * data. Note that after rb::aux_mmap_count dropped to zero,
5117 * they won't start any more (see perf_aux_output_begin()).
5119 perf_pmu_output_stop(event
);
5121 /* now it's safe to free the pages */
5122 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
5123 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
5125 /* this has to be the last one */
5127 WARN_ON_ONCE(atomic_read(&rb
->aux_refcount
));
5129 mutex_unlock(&event
->mmap_mutex
);
5132 atomic_dec(&rb
->mmap_count
);
5134 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
5137 ring_buffer_attach(event
, NULL
);
5138 mutex_unlock(&event
->mmap_mutex
);
5140 /* If there's still other mmap()s of this buffer, we're done. */
5141 if (atomic_read(&rb
->mmap_count
))
5145 * No other mmap()s, detach from all other events that might redirect
5146 * into the now unreachable buffer. Somewhat complicated by the
5147 * fact that rb::event_lock otherwise nests inside mmap_mutex.
5151 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
5152 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
5154 * This event is en-route to free_event() which will
5155 * detach it and remove it from the list.
5161 mutex_lock(&event
->mmap_mutex
);
5163 * Check we didn't race with perf_event_set_output() which can
5164 * swizzle the rb from under us while we were waiting to
5165 * acquire mmap_mutex.
5167 * If we find a different rb; ignore this event, a next
5168 * iteration will no longer find it on the list. We have to
5169 * still restart the iteration to make sure we're not now
5170 * iterating the wrong list.
5172 if (event
->rb
== rb
)
5173 ring_buffer_attach(event
, NULL
);
5175 mutex_unlock(&event
->mmap_mutex
);
5179 * Restart the iteration; either we're on the wrong list or
5180 * destroyed its integrity by doing a deletion.
5187 * It could be there's still a few 0-ref events on the list; they'll
5188 * get cleaned up by free_event() -- they'll also still have their
5189 * ref on the rb and will free it whenever they are done with it.
5191 * Aside from that, this buffer is 'fully' detached and unmapped,
5192 * undo the VM accounting.
5195 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
5196 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
5197 free_uid(mmap_user
);
5200 ring_buffer_put(rb
); /* could be last */
5203 static const struct vm_operations_struct perf_mmap_vmops
= {
5204 .open
= perf_mmap_open
,
5205 .close
= perf_mmap_close
, /* non mergable */
5206 .fault
= perf_mmap_fault
,
5207 .page_mkwrite
= perf_mmap_fault
,
5210 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
5212 struct perf_event
*event
= file
->private_data
;
5213 unsigned long user_locked
, user_lock_limit
;
5214 struct user_struct
*user
= current_user();
5215 unsigned long locked
, lock_limit
;
5216 struct ring_buffer
*rb
= NULL
;
5217 unsigned long vma_size
;
5218 unsigned long nr_pages
;
5219 long user_extra
= 0, extra
= 0;
5220 int ret
= 0, flags
= 0;
5223 * Don't allow mmap() of inherited per-task counters. This would
5224 * create a performance issue due to all children writing to the
5227 if (event
->cpu
== -1 && event
->attr
.inherit
)
5230 if (!(vma
->vm_flags
& VM_SHARED
))
5233 vma_size
= vma
->vm_end
- vma
->vm_start
;
5235 if (vma
->vm_pgoff
== 0) {
5236 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
5239 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
5240 * mapped, all subsequent mappings should have the same size
5241 * and offset. Must be above the normal perf buffer.
5243 u64 aux_offset
, aux_size
;
5248 nr_pages
= vma_size
/ PAGE_SIZE
;
5250 mutex_lock(&event
->mmap_mutex
);
5257 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
5258 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
5260 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
5263 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
5266 /* already mapped with a different offset */
5267 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
5270 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
5273 /* already mapped with a different size */
5274 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
5277 if (!is_power_of_2(nr_pages
))
5280 if (!atomic_inc_not_zero(&rb
->mmap_count
))
5283 if (rb_has_aux(rb
)) {
5284 atomic_inc(&rb
->aux_mmap_count
);
5289 atomic_set(&rb
->aux_mmap_count
, 1);
5290 user_extra
= nr_pages
;
5296 * If we have rb pages ensure they're a power-of-two number, so we
5297 * can do bitmasks instead of modulo.
5299 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
5302 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
5305 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
5307 mutex_lock(&event
->mmap_mutex
);
5309 if (event
->rb
->nr_pages
!= nr_pages
) {
5314 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
5316 * Raced against perf_mmap_close() through
5317 * perf_event_set_output(). Try again, hope for better
5320 mutex_unlock(&event
->mmap_mutex
);
5327 user_extra
= nr_pages
+ 1;
5330 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
5333 * Increase the limit linearly with more CPUs:
5335 user_lock_limit
*= num_online_cpus();
5337 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
5339 if (user_locked
> user_lock_limit
)
5340 extra
= user_locked
- user_lock_limit
;
5342 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
5343 lock_limit
>>= PAGE_SHIFT
;
5344 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
5346 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
5347 !capable(CAP_IPC_LOCK
)) {
5352 WARN_ON(!rb
&& event
->rb
);
5354 if (vma
->vm_flags
& VM_WRITE
)
5355 flags
|= RING_BUFFER_WRITABLE
;
5358 rb
= rb_alloc(nr_pages
,
5359 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
5367 atomic_set(&rb
->mmap_count
, 1);
5368 rb
->mmap_user
= get_current_user();
5369 rb
->mmap_locked
= extra
;
5371 ring_buffer_attach(event
, rb
);
5373 perf_event_init_userpage(event
);
5374 perf_event_update_userpage(event
);
5376 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
5377 event
->attr
.aux_watermark
, flags
);
5379 rb
->aux_mmap_locked
= extra
;
5384 atomic_long_add(user_extra
, &user
->locked_vm
);
5385 vma
->vm_mm
->pinned_vm
+= extra
;
5387 atomic_inc(&event
->mmap_count
);
5389 atomic_dec(&rb
->mmap_count
);
5392 mutex_unlock(&event
->mmap_mutex
);
5395 * Since pinned accounting is per vm we cannot allow fork() to copy our
5398 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
5399 vma
->vm_ops
= &perf_mmap_vmops
;
5401 if (event
->pmu
->event_mapped
)
5402 event
->pmu
->event_mapped(event
);
5407 static int perf_fasync(int fd
, struct file
*filp
, int on
)
5409 struct inode
*inode
= file_inode(filp
);
5410 struct perf_event
*event
= filp
->private_data
;
5414 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
5415 inode_unlock(inode
);
5423 static const struct file_operations perf_fops
= {
5424 .llseek
= no_llseek
,
5425 .release
= perf_release
,
5428 .unlocked_ioctl
= perf_ioctl
,
5429 .compat_ioctl
= perf_compat_ioctl
,
5431 .fasync
= perf_fasync
,
5437 * If there's data, ensure we set the poll() state and publish everything
5438 * to user-space before waking everybody up.
5441 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
5443 /* only the parent has fasync state */
5445 event
= event
->parent
;
5446 return &event
->fasync
;
5449 void perf_event_wakeup(struct perf_event
*event
)
5451 ring_buffer_wakeup(event
);
5453 if (event
->pending_kill
) {
5454 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
5455 event
->pending_kill
= 0;
5459 static void perf_pending_event(struct irq_work
*entry
)
5461 struct perf_event
*event
= container_of(entry
,
5462 struct perf_event
, pending
);
5465 rctx
= perf_swevent_get_recursion_context();
5467 * If we 'fail' here, that's OK, it means recursion is already disabled
5468 * and we won't recurse 'further'.
5471 if (event
->pending_disable
) {
5472 event
->pending_disable
= 0;
5473 perf_event_disable_local(event
);
5476 if (event
->pending_wakeup
) {
5477 event
->pending_wakeup
= 0;
5478 perf_event_wakeup(event
);
5482 perf_swevent_put_recursion_context(rctx
);
5486 * We assume there is only KVM supporting the callbacks.
5487 * Later on, we might change it to a list if there is
5488 * another virtualization implementation supporting the callbacks.
5490 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5492 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5494 perf_guest_cbs
= cbs
;
5497 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5499 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5501 perf_guest_cbs
= NULL
;
5504 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5507 perf_output_sample_regs(struct perf_output_handle
*handle
,
5508 struct pt_regs
*regs
, u64 mask
)
5511 DECLARE_BITMAP(_mask
, 64);
5513 bitmap_from_u64(_mask
, mask
);
5514 for_each_set_bit(bit
, _mask
, sizeof(mask
) * BITS_PER_BYTE
) {
5517 val
= perf_reg_value(regs
, bit
);
5518 perf_output_put(handle
, val
);
5522 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5523 struct pt_regs
*regs
,
5524 struct pt_regs
*regs_user_copy
)
5526 if (user_mode(regs
)) {
5527 regs_user
->abi
= perf_reg_abi(current
);
5528 regs_user
->regs
= regs
;
5529 } else if (current
->mm
) {
5530 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5532 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5533 regs_user
->regs
= NULL
;
5537 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5538 struct pt_regs
*regs
)
5540 regs_intr
->regs
= regs
;
5541 regs_intr
->abi
= perf_reg_abi(current
);
5546 * Get remaining task size from user stack pointer.
5548 * It'd be better to take stack vma map and limit this more
5549 * precisly, but there's no way to get it safely under interrupt,
5550 * so using TASK_SIZE as limit.
5552 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5554 unsigned long addr
= perf_user_stack_pointer(regs
);
5556 if (!addr
|| addr
>= TASK_SIZE
)
5559 return TASK_SIZE
- addr
;
5563 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5564 struct pt_regs
*regs
)
5568 /* No regs, no stack pointer, no dump. */
5573 * Check if we fit in with the requested stack size into the:
5575 * If we don't, we limit the size to the TASK_SIZE.
5577 * - remaining sample size
5578 * If we don't, we customize the stack size to
5579 * fit in to the remaining sample size.
5582 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5583 stack_size
= min(stack_size
, (u16
) task_size
);
5585 /* Current header size plus static size and dynamic size. */
5586 header_size
+= 2 * sizeof(u64
);
5588 /* Do we fit in with the current stack dump size? */
5589 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5591 * If we overflow the maximum size for the sample,
5592 * we customize the stack dump size to fit in.
5594 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5595 stack_size
= round_up(stack_size
, sizeof(u64
));
5602 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5603 struct pt_regs
*regs
)
5605 /* Case of a kernel thread, nothing to dump */
5608 perf_output_put(handle
, size
);
5617 * - the size requested by user or the best one we can fit
5618 * in to the sample max size
5620 * - user stack dump data
5622 * - the actual dumped size
5626 perf_output_put(handle
, dump_size
);
5629 sp
= perf_user_stack_pointer(regs
);
5630 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5631 dyn_size
= dump_size
- rem
;
5633 perf_output_skip(handle
, rem
);
5636 perf_output_put(handle
, dyn_size
);
5640 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5641 struct perf_sample_data
*data
,
5642 struct perf_event
*event
)
5644 u64 sample_type
= event
->attr
.sample_type
;
5646 data
->type
= sample_type
;
5647 header
->size
+= event
->id_header_size
;
5649 if (sample_type
& PERF_SAMPLE_TID
) {
5650 /* namespace issues */
5651 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5652 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5655 if (sample_type
& PERF_SAMPLE_TIME
)
5656 data
->time
= perf_event_clock(event
);
5658 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5659 data
->id
= primary_event_id(event
);
5661 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5662 data
->stream_id
= event
->id
;
5664 if (sample_type
& PERF_SAMPLE_CPU
) {
5665 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5666 data
->cpu_entry
.reserved
= 0;
5670 void perf_event_header__init_id(struct perf_event_header
*header
,
5671 struct perf_sample_data
*data
,
5672 struct perf_event
*event
)
5674 if (event
->attr
.sample_id_all
)
5675 __perf_event_header__init_id(header
, data
, event
);
5678 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5679 struct perf_sample_data
*data
)
5681 u64 sample_type
= data
->type
;
5683 if (sample_type
& PERF_SAMPLE_TID
)
5684 perf_output_put(handle
, data
->tid_entry
);
5686 if (sample_type
& PERF_SAMPLE_TIME
)
5687 perf_output_put(handle
, data
->time
);
5689 if (sample_type
& PERF_SAMPLE_ID
)
5690 perf_output_put(handle
, data
->id
);
5692 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5693 perf_output_put(handle
, data
->stream_id
);
5695 if (sample_type
& PERF_SAMPLE_CPU
)
5696 perf_output_put(handle
, data
->cpu_entry
);
5698 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5699 perf_output_put(handle
, data
->id
);
5702 void perf_event__output_id_sample(struct perf_event
*event
,
5703 struct perf_output_handle
*handle
,
5704 struct perf_sample_data
*sample
)
5706 if (event
->attr
.sample_id_all
)
5707 __perf_event__output_id_sample(handle
, sample
);
5710 static void perf_output_read_one(struct perf_output_handle
*handle
,
5711 struct perf_event
*event
,
5712 u64 enabled
, u64 running
)
5714 u64 read_format
= event
->attr
.read_format
;
5718 values
[n
++] = perf_event_count(event
);
5719 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5720 values
[n
++] = enabled
+
5721 atomic64_read(&event
->child_total_time_enabled
);
5723 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5724 values
[n
++] = running
+
5725 atomic64_read(&event
->child_total_time_running
);
5727 if (read_format
& PERF_FORMAT_ID
)
5728 values
[n
++] = primary_event_id(event
);
5730 __output_copy(handle
, values
, n
* sizeof(u64
));
5733 static void perf_output_read_group(struct perf_output_handle
*handle
,
5734 struct perf_event
*event
,
5735 u64 enabled
, u64 running
)
5737 struct perf_event
*leader
= event
->group_leader
, *sub
;
5738 u64 read_format
= event
->attr
.read_format
;
5742 values
[n
++] = 1 + leader
->nr_siblings
;
5744 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5745 values
[n
++] = enabled
;
5747 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5748 values
[n
++] = running
;
5750 if (leader
!= event
)
5751 leader
->pmu
->read(leader
);
5753 values
[n
++] = perf_event_count(leader
);
5754 if (read_format
& PERF_FORMAT_ID
)
5755 values
[n
++] = primary_event_id(leader
);
5757 __output_copy(handle
, values
, n
* sizeof(u64
));
5759 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5762 if ((sub
!= event
) &&
5763 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5764 sub
->pmu
->read(sub
);
5766 values
[n
++] = perf_event_count(sub
);
5767 if (read_format
& PERF_FORMAT_ID
)
5768 values
[n
++] = primary_event_id(sub
);
5770 __output_copy(handle
, values
, n
* sizeof(u64
));
5774 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5775 PERF_FORMAT_TOTAL_TIME_RUNNING)
5778 * XXX PERF_SAMPLE_READ vs inherited events seems difficult.
5780 * The problem is that its both hard and excessively expensive to iterate the
5781 * child list, not to mention that its impossible to IPI the children running
5782 * on another CPU, from interrupt/NMI context.
5784 static void perf_output_read(struct perf_output_handle
*handle
,
5785 struct perf_event
*event
)
5787 u64 enabled
= 0, running
= 0, now
;
5788 u64 read_format
= event
->attr
.read_format
;
5791 * compute total_time_enabled, total_time_running
5792 * based on snapshot values taken when the event
5793 * was last scheduled in.
5795 * we cannot simply called update_context_time()
5796 * because of locking issue as we are called in
5799 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5800 calc_timer_values(event
, &now
, &enabled
, &running
);
5802 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5803 perf_output_read_group(handle
, event
, enabled
, running
);
5805 perf_output_read_one(handle
, event
, enabled
, running
);
5808 void perf_output_sample(struct perf_output_handle
*handle
,
5809 struct perf_event_header
*header
,
5810 struct perf_sample_data
*data
,
5811 struct perf_event
*event
)
5813 u64 sample_type
= data
->type
;
5815 perf_output_put(handle
, *header
);
5817 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5818 perf_output_put(handle
, data
->id
);
5820 if (sample_type
& PERF_SAMPLE_IP
)
5821 perf_output_put(handle
, data
->ip
);
5823 if (sample_type
& PERF_SAMPLE_TID
)
5824 perf_output_put(handle
, data
->tid_entry
);
5826 if (sample_type
& PERF_SAMPLE_TIME
)
5827 perf_output_put(handle
, data
->time
);
5829 if (sample_type
& PERF_SAMPLE_ADDR
)
5830 perf_output_put(handle
, data
->addr
);
5832 if (sample_type
& PERF_SAMPLE_ID
)
5833 perf_output_put(handle
, data
->id
);
5835 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5836 perf_output_put(handle
, data
->stream_id
);
5838 if (sample_type
& PERF_SAMPLE_CPU
)
5839 perf_output_put(handle
, data
->cpu_entry
);
5841 if (sample_type
& PERF_SAMPLE_PERIOD
)
5842 perf_output_put(handle
, data
->period
);
5844 if (sample_type
& PERF_SAMPLE_READ
)
5845 perf_output_read(handle
, event
);
5847 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5848 if (data
->callchain
) {
5851 if (data
->callchain
)
5852 size
+= data
->callchain
->nr
;
5854 size
*= sizeof(u64
);
5856 __output_copy(handle
, data
->callchain
, size
);
5859 perf_output_put(handle
, nr
);
5863 if (sample_type
& PERF_SAMPLE_RAW
) {
5864 struct perf_raw_record
*raw
= data
->raw
;
5867 struct perf_raw_frag
*frag
= &raw
->frag
;
5869 perf_output_put(handle
, raw
->size
);
5872 __output_custom(handle
, frag
->copy
,
5873 frag
->data
, frag
->size
);
5875 __output_copy(handle
, frag
->data
,
5878 if (perf_raw_frag_last(frag
))
5883 __output_skip(handle
, NULL
, frag
->pad
);
5889 .size
= sizeof(u32
),
5892 perf_output_put(handle
, raw
);
5896 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5897 if (data
->br_stack
) {
5900 size
= data
->br_stack
->nr
5901 * sizeof(struct perf_branch_entry
);
5903 perf_output_put(handle
, data
->br_stack
->nr
);
5904 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5907 * we always store at least the value of nr
5910 perf_output_put(handle
, nr
);
5914 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5915 u64 abi
= data
->regs_user
.abi
;
5918 * If there are no regs to dump, notice it through
5919 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5921 perf_output_put(handle
, abi
);
5924 u64 mask
= event
->attr
.sample_regs_user
;
5925 perf_output_sample_regs(handle
,
5926 data
->regs_user
.regs
,
5931 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5932 perf_output_sample_ustack(handle
,
5933 data
->stack_user_size
,
5934 data
->regs_user
.regs
);
5937 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5938 perf_output_put(handle
, data
->weight
);
5940 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5941 perf_output_put(handle
, data
->data_src
.val
);
5943 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5944 perf_output_put(handle
, data
->txn
);
5946 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5947 u64 abi
= data
->regs_intr
.abi
;
5949 * If there are no regs to dump, notice it through
5950 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5952 perf_output_put(handle
, abi
);
5955 u64 mask
= event
->attr
.sample_regs_intr
;
5957 perf_output_sample_regs(handle
,
5958 data
->regs_intr
.regs
,
5963 if (!event
->attr
.watermark
) {
5964 int wakeup_events
= event
->attr
.wakeup_events
;
5966 if (wakeup_events
) {
5967 struct ring_buffer
*rb
= handle
->rb
;
5968 int events
= local_inc_return(&rb
->events
);
5970 if (events
>= wakeup_events
) {
5971 local_sub(wakeup_events
, &rb
->events
);
5972 local_inc(&rb
->wakeup
);
5978 void perf_prepare_sample(struct perf_event_header
*header
,
5979 struct perf_sample_data
*data
,
5980 struct perf_event
*event
,
5981 struct pt_regs
*regs
)
5983 u64 sample_type
= event
->attr
.sample_type
;
5985 header
->type
= PERF_RECORD_SAMPLE
;
5986 header
->size
= sizeof(*header
) + event
->header_size
;
5989 header
->misc
|= perf_misc_flags(regs
);
5991 __perf_event_header__init_id(header
, data
, event
);
5993 if (sample_type
& PERF_SAMPLE_IP
)
5994 data
->ip
= perf_instruction_pointer(regs
);
5996 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5999 data
->callchain
= perf_callchain(event
, regs
);
6001 if (data
->callchain
)
6002 size
+= data
->callchain
->nr
;
6004 header
->size
+= size
* sizeof(u64
);
6007 if (sample_type
& PERF_SAMPLE_RAW
) {
6008 struct perf_raw_record
*raw
= data
->raw
;
6012 struct perf_raw_frag
*frag
= &raw
->frag
;
6017 if (perf_raw_frag_last(frag
))
6022 size
= round_up(sum
+ sizeof(u32
), sizeof(u64
));
6023 raw
->size
= size
- sizeof(u32
);
6024 frag
->pad
= raw
->size
- sum
;
6029 header
->size
+= size
;
6032 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6033 int size
= sizeof(u64
); /* nr */
6034 if (data
->br_stack
) {
6035 size
+= data
->br_stack
->nr
6036 * sizeof(struct perf_branch_entry
);
6038 header
->size
+= size
;
6041 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
6042 perf_sample_regs_user(&data
->regs_user
, regs
,
6043 &data
->regs_user_copy
);
6045 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
6046 /* regs dump ABI info */
6047 int size
= sizeof(u64
);
6049 if (data
->regs_user
.regs
) {
6050 u64 mask
= event
->attr
.sample_regs_user
;
6051 size
+= hweight64(mask
) * sizeof(u64
);
6054 header
->size
+= size
;
6057 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
6059 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
6060 * processed as the last one or have additional check added
6061 * in case new sample type is added, because we could eat
6062 * up the rest of the sample size.
6064 u16 stack_size
= event
->attr
.sample_stack_user
;
6065 u16 size
= sizeof(u64
);
6067 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
6068 data
->regs_user
.regs
);
6071 * If there is something to dump, add space for the dump
6072 * itself and for the field that tells the dynamic size,
6073 * which is how many have been actually dumped.
6076 size
+= sizeof(u64
) + stack_size
;
6078 data
->stack_user_size
= stack_size
;
6079 header
->size
+= size
;
6082 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
6083 /* regs dump ABI info */
6084 int size
= sizeof(u64
);
6086 perf_sample_regs_intr(&data
->regs_intr
, regs
);
6088 if (data
->regs_intr
.regs
) {
6089 u64 mask
= event
->attr
.sample_regs_intr
;
6091 size
+= hweight64(mask
) * sizeof(u64
);
6094 header
->size
+= size
;
6098 static void __always_inline
6099 __perf_event_output(struct perf_event
*event
,
6100 struct perf_sample_data
*data
,
6101 struct pt_regs
*regs
,
6102 int (*output_begin
)(struct perf_output_handle
*,
6103 struct perf_event
*,
6106 struct perf_output_handle handle
;
6107 struct perf_event_header header
;
6109 /* protect the callchain buffers */
6112 perf_prepare_sample(&header
, data
, event
, regs
);
6114 if (output_begin(&handle
, event
, header
.size
))
6117 perf_output_sample(&handle
, &header
, data
, event
);
6119 perf_output_end(&handle
);
6126 perf_event_output_forward(struct perf_event
*event
,
6127 struct perf_sample_data
*data
,
6128 struct pt_regs
*regs
)
6130 __perf_event_output(event
, data
, regs
, perf_output_begin_forward
);
6134 perf_event_output_backward(struct perf_event
*event
,
6135 struct perf_sample_data
*data
,
6136 struct pt_regs
*regs
)
6138 __perf_event_output(event
, data
, regs
, perf_output_begin_backward
);
6142 perf_event_output(struct perf_event
*event
,
6143 struct perf_sample_data
*data
,
6144 struct pt_regs
*regs
)
6146 __perf_event_output(event
, data
, regs
, perf_output_begin
);
6153 struct perf_read_event
{
6154 struct perf_event_header header
;
6161 perf_event_read_event(struct perf_event
*event
,
6162 struct task_struct
*task
)
6164 struct perf_output_handle handle
;
6165 struct perf_sample_data sample
;
6166 struct perf_read_event read_event
= {
6168 .type
= PERF_RECORD_READ
,
6170 .size
= sizeof(read_event
) + event
->read_size
,
6172 .pid
= perf_event_pid(event
, task
),
6173 .tid
= perf_event_tid(event
, task
),
6177 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
6178 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
6182 perf_output_put(&handle
, read_event
);
6183 perf_output_read(&handle
, event
);
6184 perf_event__output_id_sample(event
, &handle
, &sample
);
6186 perf_output_end(&handle
);
6189 typedef void (perf_iterate_f
)(struct perf_event
*event
, void *data
);
6192 perf_iterate_ctx(struct perf_event_context
*ctx
,
6193 perf_iterate_f output
,
6194 void *data
, bool all
)
6196 struct perf_event
*event
;
6198 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6200 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6202 if (!event_filter_match(event
))
6206 output(event
, data
);
6210 static void perf_iterate_sb_cpu(perf_iterate_f output
, void *data
)
6212 struct pmu_event_list
*pel
= this_cpu_ptr(&pmu_sb_events
);
6213 struct perf_event
*event
;
6215 list_for_each_entry_rcu(event
, &pel
->list
, sb_list
) {
6217 * Skip events that are not fully formed yet; ensure that
6218 * if we observe event->ctx, both event and ctx will be
6219 * complete enough. See perf_install_in_context().
6221 if (!smp_load_acquire(&event
->ctx
))
6224 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
6226 if (!event_filter_match(event
))
6228 output(event
, data
);
6233 * Iterate all events that need to receive side-band events.
6235 * For new callers; ensure that account_pmu_sb_event() includes
6236 * your event, otherwise it might not get delivered.
6239 perf_iterate_sb(perf_iterate_f output
, void *data
,
6240 struct perf_event_context
*task_ctx
)
6242 struct perf_event_context
*ctx
;
6249 * If we have task_ctx != NULL we only notify the task context itself.
6250 * The task_ctx is set only for EXIT events before releasing task
6254 perf_iterate_ctx(task_ctx
, output
, data
, false);
6258 perf_iterate_sb_cpu(output
, data
);
6260 for_each_task_context_nr(ctxn
) {
6261 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
6263 perf_iterate_ctx(ctx
, output
, data
, false);
6271 * Clear all file-based filters at exec, they'll have to be
6272 * re-instated when/if these objects are mmapped again.
6274 static void perf_event_addr_filters_exec(struct perf_event
*event
, void *data
)
6276 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6277 struct perf_addr_filter
*filter
;
6278 unsigned int restart
= 0, count
= 0;
6279 unsigned long flags
;
6281 if (!has_addr_filter(event
))
6284 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6285 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6286 if (filter
->inode
) {
6287 event
->addr_filters_offs
[count
] = 0;
6295 event
->addr_filters_gen
++;
6296 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6299 perf_event_stop(event
, 1);
6302 void perf_event_exec(void)
6304 struct perf_event_context
*ctx
;
6308 for_each_task_context_nr(ctxn
) {
6309 ctx
= current
->perf_event_ctxp
[ctxn
];
6313 perf_event_enable_on_exec(ctxn
);
6315 perf_iterate_ctx(ctx
, perf_event_addr_filters_exec
, NULL
,
6321 struct remote_output
{
6322 struct ring_buffer
*rb
;
6326 static void __perf_event_output_stop(struct perf_event
*event
, void *data
)
6328 struct perf_event
*parent
= event
->parent
;
6329 struct remote_output
*ro
= data
;
6330 struct ring_buffer
*rb
= ro
->rb
;
6331 struct stop_event_data sd
= {
6335 if (!has_aux(event
))
6342 * In case of inheritance, it will be the parent that links to the
6343 * ring-buffer, but it will be the child that's actually using it.
6345 * We are using event::rb to determine if the event should be stopped,
6346 * however this may race with ring_buffer_attach() (through set_output),
6347 * which will make us skip the event that actually needs to be stopped.
6348 * So ring_buffer_attach() has to stop an aux event before re-assigning
6351 if (rcu_dereference(parent
->rb
) == rb
)
6352 ro
->err
= __perf_event_stop(&sd
);
6355 static int __perf_pmu_output_stop(void *info
)
6357 struct perf_event
*event
= info
;
6358 struct pmu
*pmu
= event
->pmu
;
6359 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6360 struct remote_output ro
= {
6365 perf_iterate_ctx(&cpuctx
->ctx
, __perf_event_output_stop
, &ro
, false);
6366 if (cpuctx
->task_ctx
)
6367 perf_iterate_ctx(cpuctx
->task_ctx
, __perf_event_output_stop
,
6374 static void perf_pmu_output_stop(struct perf_event
*event
)
6376 struct perf_event
*iter
;
6381 list_for_each_entry_rcu(iter
, &event
->rb
->event_list
, rb_entry
) {
6383 * For per-CPU events, we need to make sure that neither they
6384 * nor their children are running; for cpu==-1 events it's
6385 * sufficient to stop the event itself if it's active, since
6386 * it can't have children.
6390 cpu
= READ_ONCE(iter
->oncpu
);
6395 err
= cpu_function_call(cpu
, __perf_pmu_output_stop
, event
);
6396 if (err
== -EAGAIN
) {
6405 * task tracking -- fork/exit
6407 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
6410 struct perf_task_event
{
6411 struct task_struct
*task
;
6412 struct perf_event_context
*task_ctx
;
6415 struct perf_event_header header
;
6425 static int perf_event_task_match(struct perf_event
*event
)
6427 return event
->attr
.comm
|| event
->attr
.mmap
||
6428 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
6432 static void perf_event_task_output(struct perf_event
*event
,
6435 struct perf_task_event
*task_event
= data
;
6436 struct perf_output_handle handle
;
6437 struct perf_sample_data sample
;
6438 struct task_struct
*task
= task_event
->task
;
6439 int ret
, size
= task_event
->event_id
.header
.size
;
6441 if (!perf_event_task_match(event
))
6444 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
6446 ret
= perf_output_begin(&handle
, event
,
6447 task_event
->event_id
.header
.size
);
6451 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
6452 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
6454 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
6455 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
6457 task_event
->event_id
.time
= perf_event_clock(event
);
6459 perf_output_put(&handle
, task_event
->event_id
);
6461 perf_event__output_id_sample(event
, &handle
, &sample
);
6463 perf_output_end(&handle
);
6465 task_event
->event_id
.header
.size
= size
;
6468 static void perf_event_task(struct task_struct
*task
,
6469 struct perf_event_context
*task_ctx
,
6472 struct perf_task_event task_event
;
6474 if (!atomic_read(&nr_comm_events
) &&
6475 !atomic_read(&nr_mmap_events
) &&
6476 !atomic_read(&nr_task_events
))
6479 task_event
= (struct perf_task_event
){
6481 .task_ctx
= task_ctx
,
6484 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
6486 .size
= sizeof(task_event
.event_id
),
6496 perf_iterate_sb(perf_event_task_output
,
6501 void perf_event_fork(struct task_struct
*task
)
6503 perf_event_task(task
, NULL
, 1);
6504 perf_event_namespaces(task
);
6511 struct perf_comm_event
{
6512 struct task_struct
*task
;
6517 struct perf_event_header header
;
6524 static int perf_event_comm_match(struct perf_event
*event
)
6526 return event
->attr
.comm
;
6529 static void perf_event_comm_output(struct perf_event
*event
,
6532 struct perf_comm_event
*comm_event
= data
;
6533 struct perf_output_handle handle
;
6534 struct perf_sample_data sample
;
6535 int size
= comm_event
->event_id
.header
.size
;
6538 if (!perf_event_comm_match(event
))
6541 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
6542 ret
= perf_output_begin(&handle
, event
,
6543 comm_event
->event_id
.header
.size
);
6548 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
6549 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
6551 perf_output_put(&handle
, comm_event
->event_id
);
6552 __output_copy(&handle
, comm_event
->comm
,
6553 comm_event
->comm_size
);
6555 perf_event__output_id_sample(event
, &handle
, &sample
);
6557 perf_output_end(&handle
);
6559 comm_event
->event_id
.header
.size
= size
;
6562 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
6564 char comm
[TASK_COMM_LEN
];
6567 memset(comm
, 0, sizeof(comm
));
6568 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
6569 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
6571 comm_event
->comm
= comm
;
6572 comm_event
->comm_size
= size
;
6574 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
6576 perf_iterate_sb(perf_event_comm_output
,
6581 void perf_event_comm(struct task_struct
*task
, bool exec
)
6583 struct perf_comm_event comm_event
;
6585 if (!atomic_read(&nr_comm_events
))
6588 comm_event
= (struct perf_comm_event
){
6594 .type
= PERF_RECORD_COMM
,
6595 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
6603 perf_event_comm_event(&comm_event
);
6607 * namespaces tracking
6610 struct perf_namespaces_event
{
6611 struct task_struct
*task
;
6614 struct perf_event_header header
;
6619 struct perf_ns_link_info link_info
[NR_NAMESPACES
];
6623 static int perf_event_namespaces_match(struct perf_event
*event
)
6625 return event
->attr
.namespaces
;
6628 static void perf_event_namespaces_output(struct perf_event
*event
,
6631 struct perf_namespaces_event
*namespaces_event
= data
;
6632 struct perf_output_handle handle
;
6633 struct perf_sample_data sample
;
6636 if (!perf_event_namespaces_match(event
))
6639 perf_event_header__init_id(&namespaces_event
->event_id
.header
,
6641 ret
= perf_output_begin(&handle
, event
,
6642 namespaces_event
->event_id
.header
.size
);
6646 namespaces_event
->event_id
.pid
= perf_event_pid(event
,
6647 namespaces_event
->task
);
6648 namespaces_event
->event_id
.tid
= perf_event_tid(event
,
6649 namespaces_event
->task
);
6651 perf_output_put(&handle
, namespaces_event
->event_id
);
6653 perf_event__output_id_sample(event
, &handle
, &sample
);
6655 perf_output_end(&handle
);
6658 static void perf_fill_ns_link_info(struct perf_ns_link_info
*ns_link_info
,
6659 struct task_struct
*task
,
6660 const struct proc_ns_operations
*ns_ops
)
6662 struct path ns_path
;
6663 struct inode
*ns_inode
;
6666 error
= ns_get_path(&ns_path
, task
, ns_ops
);
6668 ns_inode
= ns_path
.dentry
->d_inode
;
6669 ns_link_info
->dev
= new_encode_dev(ns_inode
->i_sb
->s_dev
);
6670 ns_link_info
->ino
= ns_inode
->i_ino
;
6674 void perf_event_namespaces(struct task_struct
*task
)
6676 struct perf_namespaces_event namespaces_event
;
6677 struct perf_ns_link_info
*ns_link_info
;
6679 if (!atomic_read(&nr_namespaces_events
))
6682 namespaces_event
= (struct perf_namespaces_event
){
6686 .type
= PERF_RECORD_NAMESPACES
,
6688 .size
= sizeof(namespaces_event
.event_id
),
6692 .nr_namespaces
= NR_NAMESPACES
,
6693 /* .link_info[NR_NAMESPACES] */
6697 ns_link_info
= namespaces_event
.event_id
.link_info
;
6699 perf_fill_ns_link_info(&ns_link_info
[MNT_NS_INDEX
],
6700 task
, &mntns_operations
);
6702 #ifdef CONFIG_USER_NS
6703 perf_fill_ns_link_info(&ns_link_info
[USER_NS_INDEX
],
6704 task
, &userns_operations
);
6706 #ifdef CONFIG_NET_NS
6707 perf_fill_ns_link_info(&ns_link_info
[NET_NS_INDEX
],
6708 task
, &netns_operations
);
6710 #ifdef CONFIG_UTS_NS
6711 perf_fill_ns_link_info(&ns_link_info
[UTS_NS_INDEX
],
6712 task
, &utsns_operations
);
6714 #ifdef CONFIG_IPC_NS
6715 perf_fill_ns_link_info(&ns_link_info
[IPC_NS_INDEX
],
6716 task
, &ipcns_operations
);
6718 #ifdef CONFIG_PID_NS
6719 perf_fill_ns_link_info(&ns_link_info
[PID_NS_INDEX
],
6720 task
, &pidns_operations
);
6722 #ifdef CONFIG_CGROUPS
6723 perf_fill_ns_link_info(&ns_link_info
[CGROUP_NS_INDEX
],
6724 task
, &cgroupns_operations
);
6727 perf_iterate_sb(perf_event_namespaces_output
,
6736 struct perf_mmap_event
{
6737 struct vm_area_struct
*vma
;
6739 const char *file_name
;
6747 struct perf_event_header header
;
6757 static int perf_event_mmap_match(struct perf_event
*event
,
6760 struct perf_mmap_event
*mmap_event
= data
;
6761 struct vm_area_struct
*vma
= mmap_event
->vma
;
6762 int executable
= vma
->vm_flags
& VM_EXEC
;
6764 return (!executable
&& event
->attr
.mmap_data
) ||
6765 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
6768 static void perf_event_mmap_output(struct perf_event
*event
,
6771 struct perf_mmap_event
*mmap_event
= data
;
6772 struct perf_output_handle handle
;
6773 struct perf_sample_data sample
;
6774 int size
= mmap_event
->event_id
.header
.size
;
6777 if (!perf_event_mmap_match(event
, data
))
6780 if (event
->attr
.mmap2
) {
6781 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
6782 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
6783 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
6784 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
6785 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
6786 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
6787 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
6790 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
6791 ret
= perf_output_begin(&handle
, event
,
6792 mmap_event
->event_id
.header
.size
);
6796 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
6797 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
6799 perf_output_put(&handle
, mmap_event
->event_id
);
6801 if (event
->attr
.mmap2
) {
6802 perf_output_put(&handle
, mmap_event
->maj
);
6803 perf_output_put(&handle
, mmap_event
->min
);
6804 perf_output_put(&handle
, mmap_event
->ino
);
6805 perf_output_put(&handle
, mmap_event
->ino_generation
);
6806 perf_output_put(&handle
, mmap_event
->prot
);
6807 perf_output_put(&handle
, mmap_event
->flags
);
6810 __output_copy(&handle
, mmap_event
->file_name
,
6811 mmap_event
->file_size
);
6813 perf_event__output_id_sample(event
, &handle
, &sample
);
6815 perf_output_end(&handle
);
6817 mmap_event
->event_id
.header
.size
= size
;
6820 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
6822 struct vm_area_struct
*vma
= mmap_event
->vma
;
6823 struct file
*file
= vma
->vm_file
;
6824 int maj
= 0, min
= 0;
6825 u64 ino
= 0, gen
= 0;
6826 u32 prot
= 0, flags
= 0;
6832 if (vma
->vm_flags
& VM_READ
)
6834 if (vma
->vm_flags
& VM_WRITE
)
6836 if (vma
->vm_flags
& VM_EXEC
)
6839 if (vma
->vm_flags
& VM_MAYSHARE
)
6842 flags
= MAP_PRIVATE
;
6844 if (vma
->vm_flags
& VM_DENYWRITE
)
6845 flags
|= MAP_DENYWRITE
;
6846 if (vma
->vm_flags
& VM_MAYEXEC
)
6847 flags
|= MAP_EXECUTABLE
;
6848 if (vma
->vm_flags
& VM_LOCKED
)
6849 flags
|= MAP_LOCKED
;
6850 if (vma
->vm_flags
& VM_HUGETLB
)
6851 flags
|= MAP_HUGETLB
;
6854 struct inode
*inode
;
6857 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6863 * d_path() works from the end of the rb backwards, so we
6864 * need to add enough zero bytes after the string to handle
6865 * the 64bit alignment we do later.
6867 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6872 inode
= file_inode(vma
->vm_file
);
6873 dev
= inode
->i_sb
->s_dev
;
6875 gen
= inode
->i_generation
;
6881 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6882 name
= (char *) vma
->vm_ops
->name(vma
);
6887 name
= (char *)arch_vma_name(vma
);
6891 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6892 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6896 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6897 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6907 strlcpy(tmp
, name
, sizeof(tmp
));
6911 * Since our buffer works in 8 byte units we need to align our string
6912 * size to a multiple of 8. However, we must guarantee the tail end is
6913 * zero'd out to avoid leaking random bits to userspace.
6915 size
= strlen(name
)+1;
6916 while (!IS_ALIGNED(size
, sizeof(u64
)))
6917 name
[size
++] = '\0';
6919 mmap_event
->file_name
= name
;
6920 mmap_event
->file_size
= size
;
6921 mmap_event
->maj
= maj
;
6922 mmap_event
->min
= min
;
6923 mmap_event
->ino
= ino
;
6924 mmap_event
->ino_generation
= gen
;
6925 mmap_event
->prot
= prot
;
6926 mmap_event
->flags
= flags
;
6928 if (!(vma
->vm_flags
& VM_EXEC
))
6929 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6931 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6933 perf_iterate_sb(perf_event_mmap_output
,
6941 * Check whether inode and address range match filter criteria.
6943 static bool perf_addr_filter_match(struct perf_addr_filter
*filter
,
6944 struct file
*file
, unsigned long offset
,
6947 if (filter
->inode
!= file_inode(file
))
6950 if (filter
->offset
> offset
+ size
)
6953 if (filter
->offset
+ filter
->size
< offset
)
6959 static void __perf_addr_filters_adjust(struct perf_event
*event
, void *data
)
6961 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
6962 struct vm_area_struct
*vma
= data
;
6963 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
, flags
;
6964 struct file
*file
= vma
->vm_file
;
6965 struct perf_addr_filter
*filter
;
6966 unsigned int restart
= 0, count
= 0;
6968 if (!has_addr_filter(event
))
6974 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
6975 list_for_each_entry(filter
, &ifh
->list
, entry
) {
6976 if (perf_addr_filter_match(filter
, file
, off
,
6977 vma
->vm_end
- vma
->vm_start
)) {
6978 event
->addr_filters_offs
[count
] = vma
->vm_start
;
6986 event
->addr_filters_gen
++;
6987 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
6990 perf_event_stop(event
, 1);
6994 * Adjust all task's events' filters to the new vma
6996 static void perf_addr_filters_adjust(struct vm_area_struct
*vma
)
6998 struct perf_event_context
*ctx
;
7002 * Data tracing isn't supported yet and as such there is no need
7003 * to keep track of anything that isn't related to executable code:
7005 if (!(vma
->vm_flags
& VM_EXEC
))
7009 for_each_task_context_nr(ctxn
) {
7010 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
7014 perf_iterate_ctx(ctx
, __perf_addr_filters_adjust
, vma
, true);
7019 void perf_event_mmap(struct vm_area_struct
*vma
)
7021 struct perf_mmap_event mmap_event
;
7023 if (!atomic_read(&nr_mmap_events
))
7026 mmap_event
= (struct perf_mmap_event
){
7032 .type
= PERF_RECORD_MMAP
,
7033 .misc
= PERF_RECORD_MISC_USER
,
7038 .start
= vma
->vm_start
,
7039 .len
= vma
->vm_end
- vma
->vm_start
,
7040 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
7042 /* .maj (attr_mmap2 only) */
7043 /* .min (attr_mmap2 only) */
7044 /* .ino (attr_mmap2 only) */
7045 /* .ino_generation (attr_mmap2 only) */
7046 /* .prot (attr_mmap2 only) */
7047 /* .flags (attr_mmap2 only) */
7050 perf_addr_filters_adjust(vma
);
7051 perf_event_mmap_event(&mmap_event
);
7054 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
7055 unsigned long size
, u64 flags
)
7057 struct perf_output_handle handle
;
7058 struct perf_sample_data sample
;
7059 struct perf_aux_event
{
7060 struct perf_event_header header
;
7066 .type
= PERF_RECORD_AUX
,
7068 .size
= sizeof(rec
),
7076 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7077 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7082 perf_output_put(&handle
, rec
);
7083 perf_event__output_id_sample(event
, &handle
, &sample
);
7085 perf_output_end(&handle
);
7089 * Lost/dropped samples logging
7091 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
7093 struct perf_output_handle handle
;
7094 struct perf_sample_data sample
;
7098 struct perf_event_header header
;
7100 } lost_samples_event
= {
7102 .type
= PERF_RECORD_LOST_SAMPLES
,
7104 .size
= sizeof(lost_samples_event
),
7109 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
7111 ret
= perf_output_begin(&handle
, event
,
7112 lost_samples_event
.header
.size
);
7116 perf_output_put(&handle
, lost_samples_event
);
7117 perf_event__output_id_sample(event
, &handle
, &sample
);
7118 perf_output_end(&handle
);
7122 * context_switch tracking
7125 struct perf_switch_event
{
7126 struct task_struct
*task
;
7127 struct task_struct
*next_prev
;
7130 struct perf_event_header header
;
7136 static int perf_event_switch_match(struct perf_event
*event
)
7138 return event
->attr
.context_switch
;
7141 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
7143 struct perf_switch_event
*se
= data
;
7144 struct perf_output_handle handle
;
7145 struct perf_sample_data sample
;
7148 if (!perf_event_switch_match(event
))
7151 /* Only CPU-wide events are allowed to see next/prev pid/tid */
7152 if (event
->ctx
->task
) {
7153 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
7154 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
7156 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
7157 se
->event_id
.header
.size
= sizeof(se
->event_id
);
7158 se
->event_id
.next_prev_pid
=
7159 perf_event_pid(event
, se
->next_prev
);
7160 se
->event_id
.next_prev_tid
=
7161 perf_event_tid(event
, se
->next_prev
);
7164 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
7166 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
7170 if (event
->ctx
->task
)
7171 perf_output_put(&handle
, se
->event_id
.header
);
7173 perf_output_put(&handle
, se
->event_id
);
7175 perf_event__output_id_sample(event
, &handle
, &sample
);
7177 perf_output_end(&handle
);
7180 static void perf_event_switch(struct task_struct
*task
,
7181 struct task_struct
*next_prev
, bool sched_in
)
7183 struct perf_switch_event switch_event
;
7185 /* N.B. caller checks nr_switch_events != 0 */
7187 switch_event
= (struct perf_switch_event
){
7189 .next_prev
= next_prev
,
7193 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
7196 /* .next_prev_pid */
7197 /* .next_prev_tid */
7201 perf_iterate_sb(perf_event_switch_output
,
7207 * IRQ throttle logging
7210 static void perf_log_throttle(struct perf_event
*event
, int enable
)
7212 struct perf_output_handle handle
;
7213 struct perf_sample_data sample
;
7217 struct perf_event_header header
;
7221 } throttle_event
= {
7223 .type
= PERF_RECORD_THROTTLE
,
7225 .size
= sizeof(throttle_event
),
7227 .time
= perf_event_clock(event
),
7228 .id
= primary_event_id(event
),
7229 .stream_id
= event
->id
,
7233 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
7235 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
7237 ret
= perf_output_begin(&handle
, event
,
7238 throttle_event
.header
.size
);
7242 perf_output_put(&handle
, throttle_event
);
7243 perf_event__output_id_sample(event
, &handle
, &sample
);
7244 perf_output_end(&handle
);
7247 static void perf_log_itrace_start(struct perf_event
*event
)
7249 struct perf_output_handle handle
;
7250 struct perf_sample_data sample
;
7251 struct perf_aux_event
{
7252 struct perf_event_header header
;
7259 event
= event
->parent
;
7261 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
7262 event
->hw
.itrace_started
)
7265 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
7266 rec
.header
.misc
= 0;
7267 rec
.header
.size
= sizeof(rec
);
7268 rec
.pid
= perf_event_pid(event
, current
);
7269 rec
.tid
= perf_event_tid(event
, current
);
7271 perf_event_header__init_id(&rec
.header
, &sample
, event
);
7272 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
7277 perf_output_put(&handle
, rec
);
7278 perf_event__output_id_sample(event
, &handle
, &sample
);
7280 perf_output_end(&handle
);
7284 __perf_event_account_interrupt(struct perf_event
*event
, int throttle
)
7286 struct hw_perf_event
*hwc
= &event
->hw
;
7290 seq
= __this_cpu_read(perf_throttled_seq
);
7291 if (seq
!= hwc
->interrupts_seq
) {
7292 hwc
->interrupts_seq
= seq
;
7293 hwc
->interrupts
= 1;
7296 if (unlikely(throttle
7297 && hwc
->interrupts
>= max_samples_per_tick
)) {
7298 __this_cpu_inc(perf_throttled_count
);
7299 tick_dep_set_cpu(smp_processor_id(), TICK_DEP_BIT_PERF_EVENTS
);
7300 hwc
->interrupts
= MAX_INTERRUPTS
;
7301 perf_log_throttle(event
, 0);
7306 if (event
->attr
.freq
) {
7307 u64 now
= perf_clock();
7308 s64 delta
= now
- hwc
->freq_time_stamp
;
7310 hwc
->freq_time_stamp
= now
;
7312 if (delta
> 0 && delta
< 2*TICK_NSEC
)
7313 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
7319 int perf_event_account_interrupt(struct perf_event
*event
)
7321 return __perf_event_account_interrupt(event
, 1);
7324 static bool sample_is_allowed(struct perf_event
*event
, struct pt_regs
*regs
)
7327 * Due to interrupt latency (AKA "skid"), we may enter the
7328 * kernel before taking an overflow, even if the PMU is only
7329 * counting user events.
7330 * To avoid leaking information to userspace, we must always
7331 * reject kernel samples when exclude_kernel is set.
7333 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7340 * Generic event overflow handling, sampling.
7343 static int __perf_event_overflow(struct perf_event
*event
,
7344 int throttle
, struct perf_sample_data
*data
,
7345 struct pt_regs
*regs
)
7347 int events
= atomic_read(&event
->event_limit
);
7351 * Non-sampling counters might still use the PMI to fold short
7352 * hardware counters, ignore those.
7354 if (unlikely(!is_sampling_event(event
)))
7357 ret
= __perf_event_account_interrupt(event
, throttle
);
7360 * For security, drop the skid kernel samples if necessary.
7362 if (!sample_is_allowed(event
, regs
))
7366 * XXX event_limit might not quite work as expected on inherited
7370 event
->pending_kill
= POLL_IN
;
7371 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
7373 event
->pending_kill
= POLL_HUP
;
7375 perf_event_disable_inatomic(event
);
7378 READ_ONCE(event
->overflow_handler
)(event
, data
, regs
);
7380 if (*perf_event_fasync(event
) && event
->pending_kill
) {
7381 event
->pending_wakeup
= 1;
7382 irq_work_queue(&event
->pending
);
7388 int perf_event_overflow(struct perf_event
*event
,
7389 struct perf_sample_data
*data
,
7390 struct pt_regs
*regs
)
7392 return __perf_event_overflow(event
, 1, data
, regs
);
7396 * Generic software event infrastructure
7399 struct swevent_htable
{
7400 struct swevent_hlist
*swevent_hlist
;
7401 struct mutex hlist_mutex
;
7404 /* Recursion avoidance in each contexts */
7405 int recursion
[PERF_NR_CONTEXTS
];
7408 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
7411 * We directly increment event->count and keep a second value in
7412 * event->hw.period_left to count intervals. This period event
7413 * is kept in the range [-sample_period, 0] so that we can use the
7417 u64
perf_swevent_set_period(struct perf_event
*event
)
7419 struct hw_perf_event
*hwc
= &event
->hw
;
7420 u64 period
= hwc
->last_period
;
7424 hwc
->last_period
= hwc
->sample_period
;
7427 old
= val
= local64_read(&hwc
->period_left
);
7431 nr
= div64_u64(period
+ val
, period
);
7432 offset
= nr
* period
;
7434 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
7440 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
7441 struct perf_sample_data
*data
,
7442 struct pt_regs
*regs
)
7444 struct hw_perf_event
*hwc
= &event
->hw
;
7448 overflow
= perf_swevent_set_period(event
);
7450 if (hwc
->interrupts
== MAX_INTERRUPTS
)
7453 for (; overflow
; overflow
--) {
7454 if (__perf_event_overflow(event
, throttle
,
7457 * We inhibit the overflow from happening when
7458 * hwc->interrupts == MAX_INTERRUPTS.
7466 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
7467 struct perf_sample_data
*data
,
7468 struct pt_regs
*regs
)
7470 struct hw_perf_event
*hwc
= &event
->hw
;
7472 local64_add(nr
, &event
->count
);
7477 if (!is_sampling_event(event
))
7480 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
7482 return perf_swevent_overflow(event
, 1, data
, regs
);
7484 data
->period
= event
->hw
.last_period
;
7486 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
7487 return perf_swevent_overflow(event
, 1, data
, regs
);
7489 if (local64_add_negative(nr
, &hwc
->period_left
))
7492 perf_swevent_overflow(event
, 0, data
, regs
);
7495 static int perf_exclude_event(struct perf_event
*event
,
7496 struct pt_regs
*regs
)
7498 if (event
->hw
.state
& PERF_HES_STOPPED
)
7502 if (event
->attr
.exclude_user
&& user_mode(regs
))
7505 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
7512 static int perf_swevent_match(struct perf_event
*event
,
7513 enum perf_type_id type
,
7515 struct perf_sample_data
*data
,
7516 struct pt_regs
*regs
)
7518 if (event
->attr
.type
!= type
)
7521 if (event
->attr
.config
!= event_id
)
7524 if (perf_exclude_event(event
, regs
))
7530 static inline u64
swevent_hash(u64 type
, u32 event_id
)
7532 u64 val
= event_id
| (type
<< 32);
7534 return hash_64(val
, SWEVENT_HLIST_BITS
);
7537 static inline struct hlist_head
*
7538 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
7540 u64 hash
= swevent_hash(type
, event_id
);
7542 return &hlist
->heads
[hash
];
7545 /* For the read side: events when they trigger */
7546 static inline struct hlist_head
*
7547 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
7549 struct swevent_hlist
*hlist
;
7551 hlist
= rcu_dereference(swhash
->swevent_hlist
);
7555 return __find_swevent_head(hlist
, type
, event_id
);
7558 /* For the event head insertion and removal in the hlist */
7559 static inline struct hlist_head
*
7560 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
7562 struct swevent_hlist
*hlist
;
7563 u32 event_id
= event
->attr
.config
;
7564 u64 type
= event
->attr
.type
;
7567 * Event scheduling is always serialized against hlist allocation
7568 * and release. Which makes the protected version suitable here.
7569 * The context lock guarantees that.
7571 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
7572 lockdep_is_held(&event
->ctx
->lock
));
7576 return __find_swevent_head(hlist
, type
, event_id
);
7579 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
7581 struct perf_sample_data
*data
,
7582 struct pt_regs
*regs
)
7584 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7585 struct perf_event
*event
;
7586 struct hlist_head
*head
;
7589 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
7593 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7594 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
7595 perf_swevent_event(event
, nr
, data
, regs
);
7601 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
7603 int perf_swevent_get_recursion_context(void)
7605 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7607 return get_recursion_context(swhash
->recursion
);
7609 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
7611 void perf_swevent_put_recursion_context(int rctx
)
7613 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7615 put_recursion_context(swhash
->recursion
, rctx
);
7618 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7620 struct perf_sample_data data
;
7622 if (WARN_ON_ONCE(!regs
))
7625 perf_sample_data_init(&data
, addr
, 0);
7626 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
7629 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
7633 preempt_disable_notrace();
7634 rctx
= perf_swevent_get_recursion_context();
7635 if (unlikely(rctx
< 0))
7638 ___perf_sw_event(event_id
, nr
, regs
, addr
);
7640 perf_swevent_put_recursion_context(rctx
);
7642 preempt_enable_notrace();
7645 static void perf_swevent_read(struct perf_event
*event
)
7649 static int perf_swevent_add(struct perf_event
*event
, int flags
)
7651 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
7652 struct hw_perf_event
*hwc
= &event
->hw
;
7653 struct hlist_head
*head
;
7655 if (is_sampling_event(event
)) {
7656 hwc
->last_period
= hwc
->sample_period
;
7657 perf_swevent_set_period(event
);
7660 hwc
->state
= !(flags
& PERF_EF_START
);
7662 head
= find_swevent_head(swhash
, event
);
7663 if (WARN_ON_ONCE(!head
))
7666 hlist_add_head_rcu(&event
->hlist_entry
, head
);
7667 perf_event_update_userpage(event
);
7672 static void perf_swevent_del(struct perf_event
*event
, int flags
)
7674 hlist_del_rcu(&event
->hlist_entry
);
7677 static void perf_swevent_start(struct perf_event
*event
, int flags
)
7679 event
->hw
.state
= 0;
7682 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
7684 event
->hw
.state
= PERF_HES_STOPPED
;
7687 /* Deref the hlist from the update side */
7688 static inline struct swevent_hlist
*
7689 swevent_hlist_deref(struct swevent_htable
*swhash
)
7691 return rcu_dereference_protected(swhash
->swevent_hlist
,
7692 lockdep_is_held(&swhash
->hlist_mutex
));
7695 static void swevent_hlist_release(struct swevent_htable
*swhash
)
7697 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
7702 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
7703 kfree_rcu(hlist
, rcu_head
);
7706 static void swevent_hlist_put_cpu(int cpu
)
7708 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7710 mutex_lock(&swhash
->hlist_mutex
);
7712 if (!--swhash
->hlist_refcount
)
7713 swevent_hlist_release(swhash
);
7715 mutex_unlock(&swhash
->hlist_mutex
);
7718 static void swevent_hlist_put(void)
7722 for_each_possible_cpu(cpu
)
7723 swevent_hlist_put_cpu(cpu
);
7726 static int swevent_hlist_get_cpu(int cpu
)
7728 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7731 mutex_lock(&swhash
->hlist_mutex
);
7732 if (!swevent_hlist_deref(swhash
) &&
7733 cpumask_test_cpu(cpu
, perf_online_mask
)) {
7734 struct swevent_hlist
*hlist
;
7736 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
7741 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7743 swhash
->hlist_refcount
++;
7745 mutex_unlock(&swhash
->hlist_mutex
);
7750 static int swevent_hlist_get(void)
7752 int err
, cpu
, failed_cpu
;
7754 mutex_lock(&pmus_lock
);
7755 for_each_possible_cpu(cpu
) {
7756 err
= swevent_hlist_get_cpu(cpu
);
7762 mutex_unlock(&pmus_lock
);
7765 for_each_possible_cpu(cpu
) {
7766 if (cpu
== failed_cpu
)
7768 swevent_hlist_put_cpu(cpu
);
7770 mutex_unlock(&pmus_lock
);
7774 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
7776 static void sw_perf_event_destroy(struct perf_event
*event
)
7778 u64 event_id
= event
->attr
.config
;
7780 WARN_ON(event
->parent
);
7782 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
7783 swevent_hlist_put();
7786 static int perf_swevent_init(struct perf_event
*event
)
7788 u64 event_id
= event
->attr
.config
;
7790 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7794 * no branch sampling for software events
7796 if (has_branch_stack(event
))
7800 case PERF_COUNT_SW_CPU_CLOCK
:
7801 case PERF_COUNT_SW_TASK_CLOCK
:
7808 if (event_id
>= PERF_COUNT_SW_MAX
)
7811 if (!event
->parent
) {
7814 err
= swevent_hlist_get();
7818 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
7819 event
->destroy
= sw_perf_event_destroy
;
7825 static struct pmu perf_swevent
= {
7826 .task_ctx_nr
= perf_sw_context
,
7828 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7830 .event_init
= perf_swevent_init
,
7831 .add
= perf_swevent_add
,
7832 .del
= perf_swevent_del
,
7833 .start
= perf_swevent_start
,
7834 .stop
= perf_swevent_stop
,
7835 .read
= perf_swevent_read
,
7838 #ifdef CONFIG_EVENT_TRACING
7840 static int perf_tp_filter_match(struct perf_event
*event
,
7841 struct perf_sample_data
*data
)
7843 void *record
= data
->raw
->frag
.data
;
7845 /* only top level events have filters set */
7847 event
= event
->parent
;
7849 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
7854 static int perf_tp_event_match(struct perf_event
*event
,
7855 struct perf_sample_data
*data
,
7856 struct pt_regs
*regs
)
7858 if (event
->hw
.state
& PERF_HES_STOPPED
)
7861 * All tracepoints are from kernel-space.
7863 if (event
->attr
.exclude_kernel
)
7866 if (!perf_tp_filter_match(event
, data
))
7872 void perf_trace_run_bpf_submit(void *raw_data
, int size
, int rctx
,
7873 struct trace_event_call
*call
, u64 count
,
7874 struct pt_regs
*regs
, struct hlist_head
*head
,
7875 struct task_struct
*task
)
7877 struct bpf_prog
*prog
= call
->prog
;
7880 *(struct pt_regs
**)raw_data
= regs
;
7881 if (!trace_call_bpf(prog
, raw_data
) || hlist_empty(head
)) {
7882 perf_swevent_put_recursion_context(rctx
);
7886 perf_tp_event(call
->event
.type
, count
, raw_data
, size
, regs
, head
,
7889 EXPORT_SYMBOL_GPL(perf_trace_run_bpf_submit
);
7891 void perf_tp_event(u16 event_type
, u64 count
, void *record
, int entry_size
,
7892 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
7893 struct task_struct
*task
)
7895 struct perf_sample_data data
;
7896 struct perf_event
*event
;
7898 struct perf_raw_record raw
= {
7905 perf_sample_data_init(&data
, 0, 0);
7908 perf_trace_buf_update(record
, event_type
);
7910 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
7911 if (perf_tp_event_match(event
, &data
, regs
))
7912 perf_swevent_event(event
, count
, &data
, regs
);
7916 * If we got specified a target task, also iterate its context and
7917 * deliver this event there too.
7919 if (task
&& task
!= current
) {
7920 struct perf_event_context
*ctx
;
7921 struct trace_entry
*entry
= record
;
7924 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
7928 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
7929 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7931 if (event
->attr
.config
!= entry
->type
)
7933 if (perf_tp_event_match(event
, &data
, regs
))
7934 perf_swevent_event(event
, count
, &data
, regs
);
7940 perf_swevent_put_recursion_context(rctx
);
7942 EXPORT_SYMBOL_GPL(perf_tp_event
);
7944 static void tp_perf_event_destroy(struct perf_event
*event
)
7946 perf_trace_destroy(event
);
7949 static int perf_tp_event_init(struct perf_event
*event
)
7953 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7957 * no branch sampling for tracepoint events
7959 if (has_branch_stack(event
))
7962 err
= perf_trace_init(event
);
7966 event
->destroy
= tp_perf_event_destroy
;
7971 static struct pmu perf_tracepoint
= {
7972 .task_ctx_nr
= perf_sw_context
,
7974 .event_init
= perf_tp_event_init
,
7975 .add
= perf_trace_add
,
7976 .del
= perf_trace_del
,
7977 .start
= perf_swevent_start
,
7978 .stop
= perf_swevent_stop
,
7979 .read
= perf_swevent_read
,
7982 static inline void perf_tp_register(void)
7984 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7987 static void perf_event_free_filter(struct perf_event
*event
)
7989 ftrace_profile_free_filter(event
);
7992 #ifdef CONFIG_BPF_SYSCALL
7993 static void bpf_overflow_handler(struct perf_event
*event
,
7994 struct perf_sample_data
*data
,
7995 struct pt_regs
*regs
)
7997 struct bpf_perf_event_data_kern ctx
= {
8004 if (unlikely(__this_cpu_inc_return(bpf_prog_active
) != 1))
8007 ret
= BPF_PROG_RUN(event
->prog
, &ctx
);
8010 __this_cpu_dec(bpf_prog_active
);
8015 event
->orig_overflow_handler(event
, data
, regs
);
8018 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8020 struct bpf_prog
*prog
;
8022 if (event
->overflow_handler_context
)
8023 /* hw breakpoint or kernel counter */
8029 prog
= bpf_prog_get_type(prog_fd
, BPF_PROG_TYPE_PERF_EVENT
);
8031 return PTR_ERR(prog
);
8034 event
->orig_overflow_handler
= READ_ONCE(event
->overflow_handler
);
8035 WRITE_ONCE(event
->overflow_handler
, bpf_overflow_handler
);
8039 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8041 struct bpf_prog
*prog
= event
->prog
;
8046 WRITE_ONCE(event
->overflow_handler
, event
->orig_overflow_handler
);
8051 static int perf_event_set_bpf_handler(struct perf_event
*event
, u32 prog_fd
)
8055 static void perf_event_free_bpf_handler(struct perf_event
*event
)
8060 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8062 bool is_kprobe
, is_tracepoint
;
8063 struct bpf_prog
*prog
;
8065 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
8066 return perf_event_set_bpf_handler(event
, prog_fd
);
8068 if (event
->tp_event
->prog
)
8071 is_kprobe
= event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
;
8072 is_tracepoint
= event
->tp_event
->flags
& TRACE_EVENT_FL_TRACEPOINT
;
8073 if (!is_kprobe
&& !is_tracepoint
)
8074 /* bpf programs can only be attached to u/kprobe or tracepoint */
8077 prog
= bpf_prog_get(prog_fd
);
8079 return PTR_ERR(prog
);
8081 if ((is_kprobe
&& prog
->type
!= BPF_PROG_TYPE_KPROBE
) ||
8082 (is_tracepoint
&& prog
->type
!= BPF_PROG_TYPE_TRACEPOINT
)) {
8083 /* valid fd, but invalid bpf program type */
8088 if (is_tracepoint
) {
8089 int off
= trace_event_get_offsets(event
->tp_event
);
8091 if (prog
->aux
->max_ctx_offset
> off
) {
8096 event
->tp_event
->prog
= prog
;
8101 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8103 struct bpf_prog
*prog
;
8105 perf_event_free_bpf_handler(event
);
8107 if (!event
->tp_event
)
8110 prog
= event
->tp_event
->prog
;
8112 event
->tp_event
->prog
= NULL
;
8119 static inline void perf_tp_register(void)
8123 static void perf_event_free_filter(struct perf_event
*event
)
8127 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
8132 static void perf_event_free_bpf_prog(struct perf_event
*event
)
8135 #endif /* CONFIG_EVENT_TRACING */
8137 #ifdef CONFIG_HAVE_HW_BREAKPOINT
8138 void perf_bp_event(struct perf_event
*bp
, void *data
)
8140 struct perf_sample_data sample
;
8141 struct pt_regs
*regs
= data
;
8143 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
8145 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
8146 perf_swevent_event(bp
, 1, &sample
, regs
);
8151 * Allocate a new address filter
8153 static struct perf_addr_filter
*
8154 perf_addr_filter_new(struct perf_event
*event
, struct list_head
*filters
)
8156 int node
= cpu_to_node(event
->cpu
== -1 ? 0 : event
->cpu
);
8157 struct perf_addr_filter
*filter
;
8159 filter
= kzalloc_node(sizeof(*filter
), GFP_KERNEL
, node
);
8163 INIT_LIST_HEAD(&filter
->entry
);
8164 list_add_tail(&filter
->entry
, filters
);
8169 static void free_filters_list(struct list_head
*filters
)
8171 struct perf_addr_filter
*filter
, *iter
;
8173 list_for_each_entry_safe(filter
, iter
, filters
, entry
) {
8175 iput(filter
->inode
);
8176 list_del(&filter
->entry
);
8182 * Free existing address filters and optionally install new ones
8184 static void perf_addr_filters_splice(struct perf_event
*event
,
8185 struct list_head
*head
)
8187 unsigned long flags
;
8190 if (!has_addr_filter(event
))
8193 /* don't bother with children, they don't have their own filters */
8197 raw_spin_lock_irqsave(&event
->addr_filters
.lock
, flags
);
8199 list_splice_init(&event
->addr_filters
.list
, &list
);
8201 list_splice(head
, &event
->addr_filters
.list
);
8203 raw_spin_unlock_irqrestore(&event
->addr_filters
.lock
, flags
);
8205 free_filters_list(&list
);
8209 * Scan through mm's vmas and see if one of them matches the
8210 * @filter; if so, adjust filter's address range.
8211 * Called with mm::mmap_sem down for reading.
8213 static unsigned long perf_addr_filter_apply(struct perf_addr_filter
*filter
,
8214 struct mm_struct
*mm
)
8216 struct vm_area_struct
*vma
;
8218 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
) {
8219 struct file
*file
= vma
->vm_file
;
8220 unsigned long off
= vma
->vm_pgoff
<< PAGE_SHIFT
;
8221 unsigned long vma_size
= vma
->vm_end
- vma
->vm_start
;
8226 if (!perf_addr_filter_match(filter
, file
, off
, vma_size
))
8229 return vma
->vm_start
;
8236 * Update event's address range filters based on the
8237 * task's existing mappings, if any.
8239 static void perf_event_addr_filters_apply(struct perf_event
*event
)
8241 struct perf_addr_filters_head
*ifh
= perf_event_addr_filters(event
);
8242 struct task_struct
*task
= READ_ONCE(event
->ctx
->task
);
8243 struct perf_addr_filter
*filter
;
8244 struct mm_struct
*mm
= NULL
;
8245 unsigned int count
= 0;
8246 unsigned long flags
;
8249 * We may observe TASK_TOMBSTONE, which means that the event tear-down
8250 * will stop on the parent's child_mutex that our caller is also holding
8252 if (task
== TASK_TOMBSTONE
)
8255 if (!ifh
->nr_file_filters
)
8258 mm
= get_task_mm(event
->ctx
->task
);
8262 down_read(&mm
->mmap_sem
);
8264 raw_spin_lock_irqsave(&ifh
->lock
, flags
);
8265 list_for_each_entry(filter
, &ifh
->list
, entry
) {
8266 event
->addr_filters_offs
[count
] = 0;
8269 * Adjust base offset if the filter is associated to a binary
8270 * that needs to be mapped:
8273 event
->addr_filters_offs
[count
] =
8274 perf_addr_filter_apply(filter
, mm
);
8279 event
->addr_filters_gen
++;
8280 raw_spin_unlock_irqrestore(&ifh
->lock
, flags
);
8282 up_read(&mm
->mmap_sem
);
8287 perf_event_stop(event
, 1);
8291 * Address range filtering: limiting the data to certain
8292 * instruction address ranges. Filters are ioctl()ed to us from
8293 * userspace as ascii strings.
8295 * Filter string format:
8298 * where ACTION is one of the
8299 * * "filter": limit the trace to this region
8300 * * "start": start tracing from this address
8301 * * "stop": stop tracing at this address/region;
8303 * * for kernel addresses: <start address>[/<size>]
8304 * * for object files: <start address>[/<size>]@</path/to/object/file>
8306 * if <size> is not specified, the range is treated as a single address.
8320 IF_STATE_ACTION
= 0,
8325 static const match_table_t if_tokens
= {
8326 { IF_ACT_FILTER
, "filter" },
8327 { IF_ACT_START
, "start" },
8328 { IF_ACT_STOP
, "stop" },
8329 { IF_SRC_FILE
, "%u/%u@%s" },
8330 { IF_SRC_KERNEL
, "%u/%u" },
8331 { IF_SRC_FILEADDR
, "%u@%s" },
8332 { IF_SRC_KERNELADDR
, "%u" },
8333 { IF_ACT_NONE
, NULL
},
8337 * Address filter string parser
8340 perf_event_parse_addr_filter(struct perf_event
*event
, char *fstr
,
8341 struct list_head
*filters
)
8343 struct perf_addr_filter
*filter
= NULL
;
8344 char *start
, *orig
, *filename
= NULL
;
8346 substring_t args
[MAX_OPT_ARGS
];
8347 int state
= IF_STATE_ACTION
, token
;
8348 unsigned int kernel
= 0;
8351 orig
= fstr
= kstrdup(fstr
, GFP_KERNEL
);
8355 while ((start
= strsep(&fstr
, " ,\n")) != NULL
) {
8361 /* filter definition begins */
8362 if (state
== IF_STATE_ACTION
) {
8363 filter
= perf_addr_filter_new(event
, filters
);
8368 token
= match_token(start
, if_tokens
, args
);
8375 if (state
!= IF_STATE_ACTION
)
8378 state
= IF_STATE_SOURCE
;
8381 case IF_SRC_KERNELADDR
:
8385 case IF_SRC_FILEADDR
:
8387 if (state
!= IF_STATE_SOURCE
)
8390 if (token
== IF_SRC_FILE
|| token
== IF_SRC_KERNEL
)
8394 ret
= kstrtoul(args
[0].from
, 0, &filter
->offset
);
8398 if (filter
->range
) {
8400 ret
= kstrtoul(args
[1].from
, 0, &filter
->size
);
8405 if (token
== IF_SRC_FILE
|| token
== IF_SRC_FILEADDR
) {
8406 int fpos
= filter
->range
? 2 : 1;
8408 filename
= match_strdup(&args
[fpos
]);
8415 state
= IF_STATE_END
;
8423 * Filter definition is fully parsed, validate and install it.
8424 * Make sure that it doesn't contradict itself or the event's
8427 if (state
== IF_STATE_END
) {
8429 if (kernel
&& event
->attr
.exclude_kernel
)
8437 * For now, we only support file-based filters
8438 * in per-task events; doing so for CPU-wide
8439 * events requires additional context switching
8440 * trickery, since same object code will be
8441 * mapped at different virtual addresses in
8442 * different processes.
8445 if (!event
->ctx
->task
)
8446 goto fail_free_name
;
8448 /* look up the path and grab its inode */
8449 ret
= kern_path(filename
, LOOKUP_FOLLOW
, &path
);
8451 goto fail_free_name
;
8453 filter
->inode
= igrab(d_inode(path
.dentry
));
8459 if (!filter
->inode
||
8460 !S_ISREG(filter
->inode
->i_mode
))
8461 /* free_filters_list() will iput() */
8464 event
->addr_filters
.nr_file_filters
++;
8467 /* ready to consume more filters */
8468 state
= IF_STATE_ACTION
;
8473 if (state
!= IF_STATE_ACTION
)
8483 free_filters_list(filters
);
8490 perf_event_set_addr_filter(struct perf_event
*event
, char *filter_str
)
8496 * Since this is called in perf_ioctl() path, we're already holding
8499 lockdep_assert_held(&event
->ctx
->mutex
);
8501 if (WARN_ON_ONCE(event
->parent
))
8504 ret
= perf_event_parse_addr_filter(event
, filter_str
, &filters
);
8506 goto fail_clear_files
;
8508 ret
= event
->pmu
->addr_filters_validate(&filters
);
8510 goto fail_free_filters
;
8512 /* remove existing filters, if any */
8513 perf_addr_filters_splice(event
, &filters
);
8515 /* install new filters */
8516 perf_event_for_each_child(event
, perf_event_addr_filters_apply
);
8521 free_filters_list(&filters
);
8524 event
->addr_filters
.nr_file_filters
= 0;
8529 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
8534 if ((event
->attr
.type
!= PERF_TYPE_TRACEPOINT
||
8535 !IS_ENABLED(CONFIG_EVENT_TRACING
)) &&
8536 !has_addr_filter(event
))
8539 filter_str
= strndup_user(arg
, PAGE_SIZE
);
8540 if (IS_ERR(filter_str
))
8541 return PTR_ERR(filter_str
);
8543 if (IS_ENABLED(CONFIG_EVENT_TRACING
) &&
8544 event
->attr
.type
== PERF_TYPE_TRACEPOINT
)
8545 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
,
8547 else if (has_addr_filter(event
))
8548 ret
= perf_event_set_addr_filter(event
, filter_str
);
8555 * hrtimer based swevent callback
8558 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
8560 enum hrtimer_restart ret
= HRTIMER_RESTART
;
8561 struct perf_sample_data data
;
8562 struct pt_regs
*regs
;
8563 struct perf_event
*event
;
8566 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
8568 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
8569 return HRTIMER_NORESTART
;
8571 event
->pmu
->read(event
);
8573 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
8574 regs
= get_irq_regs();
8576 if (regs
&& !perf_exclude_event(event
, regs
)) {
8577 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
8578 if (__perf_event_overflow(event
, 1, &data
, regs
))
8579 ret
= HRTIMER_NORESTART
;
8582 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
8583 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
8588 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
8590 struct hw_perf_event
*hwc
= &event
->hw
;
8593 if (!is_sampling_event(event
))
8596 period
= local64_read(&hwc
->period_left
);
8601 local64_set(&hwc
->period_left
, 0);
8603 period
= max_t(u64
, 10000, hwc
->sample_period
);
8605 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
8606 HRTIMER_MODE_REL_PINNED
);
8609 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
8611 struct hw_perf_event
*hwc
= &event
->hw
;
8613 if (is_sampling_event(event
)) {
8614 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
8615 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
8617 hrtimer_cancel(&hwc
->hrtimer
);
8621 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
8623 struct hw_perf_event
*hwc
= &event
->hw
;
8625 if (!is_sampling_event(event
))
8628 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
8629 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
8632 * Since hrtimers have a fixed rate, we can do a static freq->period
8633 * mapping and avoid the whole period adjust feedback stuff.
8635 if (event
->attr
.freq
) {
8636 long freq
= event
->attr
.sample_freq
;
8638 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
8639 hwc
->sample_period
= event
->attr
.sample_period
;
8640 local64_set(&hwc
->period_left
, hwc
->sample_period
);
8641 hwc
->last_period
= hwc
->sample_period
;
8642 event
->attr
.freq
= 0;
8647 * Software event: cpu wall time clock
8650 static void cpu_clock_event_update(struct perf_event
*event
)
8655 now
= local_clock();
8656 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8657 local64_add(now
- prev
, &event
->count
);
8660 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
8662 local64_set(&event
->hw
.prev_count
, local_clock());
8663 perf_swevent_start_hrtimer(event
);
8666 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
8668 perf_swevent_cancel_hrtimer(event
);
8669 cpu_clock_event_update(event
);
8672 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
8674 if (flags
& PERF_EF_START
)
8675 cpu_clock_event_start(event
, flags
);
8676 perf_event_update_userpage(event
);
8681 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
8683 cpu_clock_event_stop(event
, flags
);
8686 static void cpu_clock_event_read(struct perf_event
*event
)
8688 cpu_clock_event_update(event
);
8691 static int cpu_clock_event_init(struct perf_event
*event
)
8693 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8696 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
8700 * no branch sampling for software events
8702 if (has_branch_stack(event
))
8705 perf_swevent_init_hrtimer(event
);
8710 static struct pmu perf_cpu_clock
= {
8711 .task_ctx_nr
= perf_sw_context
,
8713 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8715 .event_init
= cpu_clock_event_init
,
8716 .add
= cpu_clock_event_add
,
8717 .del
= cpu_clock_event_del
,
8718 .start
= cpu_clock_event_start
,
8719 .stop
= cpu_clock_event_stop
,
8720 .read
= cpu_clock_event_read
,
8724 * Software event: task time clock
8727 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
8732 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
8734 local64_add(delta
, &event
->count
);
8737 static void task_clock_event_start(struct perf_event
*event
, int flags
)
8739 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
8740 perf_swevent_start_hrtimer(event
);
8743 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
8745 perf_swevent_cancel_hrtimer(event
);
8746 task_clock_event_update(event
, event
->ctx
->time
);
8749 static int task_clock_event_add(struct perf_event
*event
, int flags
)
8751 if (flags
& PERF_EF_START
)
8752 task_clock_event_start(event
, flags
);
8753 perf_event_update_userpage(event
);
8758 static void task_clock_event_del(struct perf_event
*event
, int flags
)
8760 task_clock_event_stop(event
, PERF_EF_UPDATE
);
8763 static void task_clock_event_read(struct perf_event
*event
)
8765 u64 now
= perf_clock();
8766 u64 delta
= now
- event
->ctx
->timestamp
;
8767 u64 time
= event
->ctx
->time
+ delta
;
8769 task_clock_event_update(event
, time
);
8772 static int task_clock_event_init(struct perf_event
*event
)
8774 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
8777 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
8781 * no branch sampling for software events
8783 if (has_branch_stack(event
))
8786 perf_swevent_init_hrtimer(event
);
8791 static struct pmu perf_task_clock
= {
8792 .task_ctx_nr
= perf_sw_context
,
8794 .capabilities
= PERF_PMU_CAP_NO_NMI
,
8796 .event_init
= task_clock_event_init
,
8797 .add
= task_clock_event_add
,
8798 .del
= task_clock_event_del
,
8799 .start
= task_clock_event_start
,
8800 .stop
= task_clock_event_stop
,
8801 .read
= task_clock_event_read
,
8804 static void perf_pmu_nop_void(struct pmu
*pmu
)
8808 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
8812 static int perf_pmu_nop_int(struct pmu
*pmu
)
8817 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
8819 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
8821 __this_cpu_write(nop_txn_flags
, flags
);
8823 if (flags
& ~PERF_PMU_TXN_ADD
)
8826 perf_pmu_disable(pmu
);
8829 static int perf_pmu_commit_txn(struct pmu
*pmu
)
8831 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8833 __this_cpu_write(nop_txn_flags
, 0);
8835 if (flags
& ~PERF_PMU_TXN_ADD
)
8838 perf_pmu_enable(pmu
);
8842 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
8844 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
8846 __this_cpu_write(nop_txn_flags
, 0);
8848 if (flags
& ~PERF_PMU_TXN_ADD
)
8851 perf_pmu_enable(pmu
);
8854 static int perf_event_idx_default(struct perf_event
*event
)
8860 * Ensures all contexts with the same task_ctx_nr have the same
8861 * pmu_cpu_context too.
8863 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
8870 list_for_each_entry(pmu
, &pmus
, entry
) {
8871 if (pmu
->task_ctx_nr
== ctxn
)
8872 return pmu
->pmu_cpu_context
;
8878 static void free_pmu_context(struct pmu
*pmu
)
8880 mutex_lock(&pmus_lock
);
8881 free_percpu(pmu
->pmu_cpu_context
);
8882 mutex_unlock(&pmus_lock
);
8886 * Let userspace know that this PMU supports address range filtering:
8888 static ssize_t
nr_addr_filters_show(struct device
*dev
,
8889 struct device_attribute
*attr
,
8892 struct pmu
*pmu
= dev_get_drvdata(dev
);
8894 return snprintf(page
, PAGE_SIZE
- 1, "%d\n", pmu
->nr_addr_filters
);
8896 DEVICE_ATTR_RO(nr_addr_filters
);
8898 static struct idr pmu_idr
;
8901 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
8903 struct pmu
*pmu
= dev_get_drvdata(dev
);
8905 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
8907 static DEVICE_ATTR_RO(type
);
8910 perf_event_mux_interval_ms_show(struct device
*dev
,
8911 struct device_attribute
*attr
,
8914 struct pmu
*pmu
= dev_get_drvdata(dev
);
8916 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
8919 static DEFINE_MUTEX(mux_interval_mutex
);
8922 perf_event_mux_interval_ms_store(struct device
*dev
,
8923 struct device_attribute
*attr
,
8924 const char *buf
, size_t count
)
8926 struct pmu
*pmu
= dev_get_drvdata(dev
);
8927 int timer
, cpu
, ret
;
8929 ret
= kstrtoint(buf
, 0, &timer
);
8936 /* same value, noting to do */
8937 if (timer
== pmu
->hrtimer_interval_ms
)
8940 mutex_lock(&mux_interval_mutex
);
8941 pmu
->hrtimer_interval_ms
= timer
;
8943 /* update all cpuctx for this PMU */
8945 for_each_online_cpu(cpu
) {
8946 struct perf_cpu_context
*cpuctx
;
8947 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
8948 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
8950 cpu_function_call(cpu
,
8951 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
8954 mutex_unlock(&mux_interval_mutex
);
8958 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
8960 static struct attribute
*pmu_dev_attrs
[] = {
8961 &dev_attr_type
.attr
,
8962 &dev_attr_perf_event_mux_interval_ms
.attr
,
8965 ATTRIBUTE_GROUPS(pmu_dev
);
8967 static int pmu_bus_running
;
8968 static struct bus_type pmu_bus
= {
8969 .name
= "event_source",
8970 .dev_groups
= pmu_dev_groups
,
8973 static void pmu_dev_release(struct device
*dev
)
8978 static int pmu_dev_alloc(struct pmu
*pmu
)
8982 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
8986 pmu
->dev
->groups
= pmu
->attr_groups
;
8987 device_initialize(pmu
->dev
);
8988 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
8992 dev_set_drvdata(pmu
->dev
, pmu
);
8993 pmu
->dev
->bus
= &pmu_bus
;
8994 pmu
->dev
->release
= pmu_dev_release
;
8995 ret
= device_add(pmu
->dev
);
8999 /* For PMUs with address filters, throw in an extra attribute: */
9000 if (pmu
->nr_addr_filters
)
9001 ret
= device_create_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9010 device_del(pmu
->dev
);
9013 put_device(pmu
->dev
);
9017 static struct lock_class_key cpuctx_mutex
;
9018 static struct lock_class_key cpuctx_lock
;
9020 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
9024 mutex_lock(&pmus_lock
);
9026 pmu
->pmu_disable_count
= alloc_percpu(int);
9027 if (!pmu
->pmu_disable_count
)
9036 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
9044 if (pmu_bus_running
) {
9045 ret
= pmu_dev_alloc(pmu
);
9051 if (pmu
->task_ctx_nr
== perf_hw_context
) {
9052 static int hw_context_taken
= 0;
9055 * Other than systems with heterogeneous CPUs, it never makes
9056 * sense for two PMUs to share perf_hw_context. PMUs which are
9057 * uncore must use perf_invalid_context.
9059 if (WARN_ON_ONCE(hw_context_taken
&&
9060 !(pmu
->capabilities
& PERF_PMU_CAP_HETEROGENEOUS_CPUS
)))
9061 pmu
->task_ctx_nr
= perf_invalid_context
;
9063 hw_context_taken
= 1;
9066 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
9067 if (pmu
->pmu_cpu_context
)
9068 goto got_cpu_context
;
9071 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
9072 if (!pmu
->pmu_cpu_context
)
9075 for_each_possible_cpu(cpu
) {
9076 struct perf_cpu_context
*cpuctx
;
9078 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
9079 __perf_event_init_context(&cpuctx
->ctx
);
9080 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
9081 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
9082 cpuctx
->ctx
.pmu
= pmu
;
9083 cpuctx
->online
= cpumask_test_cpu(cpu
, perf_online_mask
);
9085 __perf_mux_hrtimer_init(cpuctx
, cpu
);
9089 if (!pmu
->start_txn
) {
9090 if (pmu
->pmu_enable
) {
9092 * If we have pmu_enable/pmu_disable calls, install
9093 * transaction stubs that use that to try and batch
9094 * hardware accesses.
9096 pmu
->start_txn
= perf_pmu_start_txn
;
9097 pmu
->commit_txn
= perf_pmu_commit_txn
;
9098 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
9100 pmu
->start_txn
= perf_pmu_nop_txn
;
9101 pmu
->commit_txn
= perf_pmu_nop_int
;
9102 pmu
->cancel_txn
= perf_pmu_nop_void
;
9106 if (!pmu
->pmu_enable
) {
9107 pmu
->pmu_enable
= perf_pmu_nop_void
;
9108 pmu
->pmu_disable
= perf_pmu_nop_void
;
9111 if (!pmu
->event_idx
)
9112 pmu
->event_idx
= perf_event_idx_default
;
9114 list_add_rcu(&pmu
->entry
, &pmus
);
9115 atomic_set(&pmu
->exclusive_cnt
, 0);
9118 mutex_unlock(&pmus_lock
);
9123 device_del(pmu
->dev
);
9124 put_device(pmu
->dev
);
9127 if (pmu
->type
>= PERF_TYPE_MAX
)
9128 idr_remove(&pmu_idr
, pmu
->type
);
9131 free_percpu(pmu
->pmu_disable_count
);
9134 EXPORT_SYMBOL_GPL(perf_pmu_register
);
9136 void perf_pmu_unregister(struct pmu
*pmu
)
9140 mutex_lock(&pmus_lock
);
9141 remove_device
= pmu_bus_running
;
9142 list_del_rcu(&pmu
->entry
);
9143 mutex_unlock(&pmus_lock
);
9146 * We dereference the pmu list under both SRCU and regular RCU, so
9147 * synchronize against both of those.
9149 synchronize_srcu(&pmus_srcu
);
9152 free_percpu(pmu
->pmu_disable_count
);
9153 if (pmu
->type
>= PERF_TYPE_MAX
)
9154 idr_remove(&pmu_idr
, pmu
->type
);
9155 if (remove_device
) {
9156 if (pmu
->nr_addr_filters
)
9157 device_remove_file(pmu
->dev
, &dev_attr_nr_addr_filters
);
9158 device_del(pmu
->dev
);
9159 put_device(pmu
->dev
);
9161 free_pmu_context(pmu
);
9163 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
9165 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
9167 struct perf_event_context
*ctx
= NULL
;
9170 if (!try_module_get(pmu
->module
))
9173 if (event
->group_leader
!= event
) {
9175 * This ctx->mutex can nest when we're called through
9176 * inheritance. See the perf_event_ctx_lock_nested() comment.
9178 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
9179 SINGLE_DEPTH_NESTING
);
9184 ret
= pmu
->event_init(event
);
9187 perf_event_ctx_unlock(event
->group_leader
, ctx
);
9190 module_put(pmu
->module
);
9195 static struct pmu
*perf_init_event(struct perf_event
*event
)
9201 idx
= srcu_read_lock(&pmus_srcu
);
9203 /* Try parent's PMU first: */
9204 if (event
->parent
&& event
->parent
->pmu
) {
9205 pmu
= event
->parent
->pmu
;
9206 ret
= perf_try_init_event(pmu
, event
);
9212 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
9215 ret
= perf_try_init_event(pmu
, event
);
9221 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9222 ret
= perf_try_init_event(pmu
, event
);
9226 if (ret
!= -ENOENT
) {
9231 pmu
= ERR_PTR(-ENOENT
);
9233 srcu_read_unlock(&pmus_srcu
, idx
);
9238 static void attach_sb_event(struct perf_event
*event
)
9240 struct pmu_event_list
*pel
= per_cpu_ptr(&pmu_sb_events
, event
->cpu
);
9242 raw_spin_lock(&pel
->lock
);
9243 list_add_rcu(&event
->sb_list
, &pel
->list
);
9244 raw_spin_unlock(&pel
->lock
);
9248 * We keep a list of all !task (and therefore per-cpu) events
9249 * that need to receive side-band records.
9251 * This avoids having to scan all the various PMU per-cpu contexts
9254 static void account_pmu_sb_event(struct perf_event
*event
)
9256 if (is_sb_event(event
))
9257 attach_sb_event(event
);
9260 static void account_event_cpu(struct perf_event
*event
, int cpu
)
9265 if (is_cgroup_event(event
))
9266 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
9269 /* Freq events need the tick to stay alive (see perf_event_task_tick). */
9270 static void account_freq_event_nohz(void)
9272 #ifdef CONFIG_NO_HZ_FULL
9273 /* Lock so we don't race with concurrent unaccount */
9274 spin_lock(&nr_freq_lock
);
9275 if (atomic_inc_return(&nr_freq_events
) == 1)
9276 tick_nohz_dep_set(TICK_DEP_BIT_PERF_EVENTS
);
9277 spin_unlock(&nr_freq_lock
);
9281 static void account_freq_event(void)
9283 if (tick_nohz_full_enabled())
9284 account_freq_event_nohz();
9286 atomic_inc(&nr_freq_events
);
9290 static void account_event(struct perf_event
*event
)
9297 if (event
->attach_state
& PERF_ATTACH_TASK
)
9299 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
9300 atomic_inc(&nr_mmap_events
);
9301 if (event
->attr
.comm
)
9302 atomic_inc(&nr_comm_events
);
9303 if (event
->attr
.namespaces
)
9304 atomic_inc(&nr_namespaces_events
);
9305 if (event
->attr
.task
)
9306 atomic_inc(&nr_task_events
);
9307 if (event
->attr
.freq
)
9308 account_freq_event();
9309 if (event
->attr
.context_switch
) {
9310 atomic_inc(&nr_switch_events
);
9313 if (has_branch_stack(event
))
9315 if (is_cgroup_event(event
))
9319 if (atomic_inc_not_zero(&perf_sched_count
))
9322 mutex_lock(&perf_sched_mutex
);
9323 if (!atomic_read(&perf_sched_count
)) {
9324 static_branch_enable(&perf_sched_events
);
9326 * Guarantee that all CPUs observe they key change and
9327 * call the perf scheduling hooks before proceeding to
9328 * install events that need them.
9330 synchronize_sched();
9333 * Now that we have waited for the sync_sched(), allow further
9334 * increments to by-pass the mutex.
9336 atomic_inc(&perf_sched_count
);
9337 mutex_unlock(&perf_sched_mutex
);
9341 account_event_cpu(event
, event
->cpu
);
9343 account_pmu_sb_event(event
);
9347 * Allocate and initialize a event structure
9349 static struct perf_event
*
9350 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
9351 struct task_struct
*task
,
9352 struct perf_event
*group_leader
,
9353 struct perf_event
*parent_event
,
9354 perf_overflow_handler_t overflow_handler
,
9355 void *context
, int cgroup_fd
)
9358 struct perf_event
*event
;
9359 struct hw_perf_event
*hwc
;
9362 if ((unsigned)cpu
>= nr_cpu_ids
) {
9363 if (!task
|| cpu
!= -1)
9364 return ERR_PTR(-EINVAL
);
9367 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
9369 return ERR_PTR(-ENOMEM
);
9372 * Single events are their own group leaders, with an
9373 * empty sibling list:
9376 group_leader
= event
;
9378 mutex_init(&event
->child_mutex
);
9379 INIT_LIST_HEAD(&event
->child_list
);
9381 INIT_LIST_HEAD(&event
->group_entry
);
9382 INIT_LIST_HEAD(&event
->event_entry
);
9383 INIT_LIST_HEAD(&event
->sibling_list
);
9384 INIT_LIST_HEAD(&event
->rb_entry
);
9385 INIT_LIST_HEAD(&event
->active_entry
);
9386 INIT_LIST_HEAD(&event
->addr_filters
.list
);
9387 INIT_HLIST_NODE(&event
->hlist_entry
);
9390 init_waitqueue_head(&event
->waitq
);
9391 init_irq_work(&event
->pending
, perf_pending_event
);
9393 mutex_init(&event
->mmap_mutex
);
9394 raw_spin_lock_init(&event
->addr_filters
.lock
);
9396 atomic_long_set(&event
->refcount
, 1);
9398 event
->attr
= *attr
;
9399 event
->group_leader
= group_leader
;
9403 event
->parent
= parent_event
;
9405 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
9406 event
->id
= atomic64_inc_return(&perf_event_id
);
9408 event
->state
= PERF_EVENT_STATE_INACTIVE
;
9411 event
->attach_state
= PERF_ATTACH_TASK
;
9413 * XXX pmu::event_init needs to know what task to account to
9414 * and we cannot use the ctx information because we need the
9415 * pmu before we get a ctx.
9417 event
->hw
.target
= task
;
9420 event
->clock
= &local_clock
;
9422 event
->clock
= parent_event
->clock
;
9424 if (!overflow_handler
&& parent_event
) {
9425 overflow_handler
= parent_event
->overflow_handler
;
9426 context
= parent_event
->overflow_handler_context
;
9427 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
9428 if (overflow_handler
== bpf_overflow_handler
) {
9429 struct bpf_prog
*prog
= bpf_prog_inc(parent_event
->prog
);
9432 err
= PTR_ERR(prog
);
9436 event
->orig_overflow_handler
=
9437 parent_event
->orig_overflow_handler
;
9442 if (overflow_handler
) {
9443 event
->overflow_handler
= overflow_handler
;
9444 event
->overflow_handler_context
= context
;
9445 } else if (is_write_backward(event
)){
9446 event
->overflow_handler
= perf_event_output_backward
;
9447 event
->overflow_handler_context
= NULL
;
9449 event
->overflow_handler
= perf_event_output_forward
;
9450 event
->overflow_handler_context
= NULL
;
9453 perf_event__state_init(event
);
9458 hwc
->sample_period
= attr
->sample_period
;
9459 if (attr
->freq
&& attr
->sample_freq
)
9460 hwc
->sample_period
= 1;
9461 hwc
->last_period
= hwc
->sample_period
;
9463 local64_set(&hwc
->period_left
, hwc
->sample_period
);
9466 * We currently do not support PERF_SAMPLE_READ on inherited events.
9467 * See perf_output_read().
9469 if (attr
->inherit
&& (attr
->sample_type
& PERF_SAMPLE_READ
))
9472 if (!has_branch_stack(event
))
9473 event
->attr
.branch_sample_type
= 0;
9475 if (cgroup_fd
!= -1) {
9476 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
9481 pmu
= perf_init_event(event
);
9487 err
= exclusive_event_init(event
);
9491 if (has_addr_filter(event
)) {
9492 event
->addr_filters_offs
= kcalloc(pmu
->nr_addr_filters
,
9493 sizeof(unsigned long),
9495 if (!event
->addr_filters_offs
) {
9500 /* force hw sync on the address filters */
9501 event
->addr_filters_gen
= 1;
9504 if (!event
->parent
) {
9505 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
9506 err
= get_callchain_buffers(attr
->sample_max_stack
);
9508 goto err_addr_filters
;
9512 /* symmetric to unaccount_event() in _free_event() */
9513 account_event(event
);
9518 kfree(event
->addr_filters_offs
);
9521 exclusive_event_destroy(event
);
9525 event
->destroy(event
);
9526 module_put(pmu
->module
);
9528 if (is_cgroup_event(event
))
9529 perf_detach_cgroup(event
);
9531 put_pid_ns(event
->ns
);
9534 return ERR_PTR(err
);
9537 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
9538 struct perf_event_attr
*attr
)
9543 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
9547 * zero the full structure, so that a short copy will be nice.
9549 memset(attr
, 0, sizeof(*attr
));
9551 ret
= get_user(size
, &uattr
->size
);
9555 if (size
> PAGE_SIZE
) /* silly large */
9558 if (!size
) /* abi compat */
9559 size
= PERF_ATTR_SIZE_VER0
;
9561 if (size
< PERF_ATTR_SIZE_VER0
)
9565 * If we're handed a bigger struct than we know of,
9566 * ensure all the unknown bits are 0 - i.e. new
9567 * user-space does not rely on any kernel feature
9568 * extensions we dont know about yet.
9570 if (size
> sizeof(*attr
)) {
9571 unsigned char __user
*addr
;
9572 unsigned char __user
*end
;
9575 addr
= (void __user
*)uattr
+ sizeof(*attr
);
9576 end
= (void __user
*)uattr
+ size
;
9578 for (; addr
< end
; addr
++) {
9579 ret
= get_user(val
, addr
);
9585 size
= sizeof(*attr
);
9588 ret
= copy_from_user(attr
, uattr
, size
);
9592 if (attr
->__reserved_1
)
9595 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
9598 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
9601 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
9602 u64 mask
= attr
->branch_sample_type
;
9604 /* only using defined bits */
9605 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
9608 /* at least one branch bit must be set */
9609 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
9612 /* propagate priv level, when not set for branch */
9613 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
9615 /* exclude_kernel checked on syscall entry */
9616 if (!attr
->exclude_kernel
)
9617 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
9619 if (!attr
->exclude_user
)
9620 mask
|= PERF_SAMPLE_BRANCH_USER
;
9622 if (!attr
->exclude_hv
)
9623 mask
|= PERF_SAMPLE_BRANCH_HV
;
9625 * adjust user setting (for HW filter setup)
9627 attr
->branch_sample_type
= mask
;
9629 /* privileged levels capture (kernel, hv): check permissions */
9630 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
9631 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9635 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
9636 ret
= perf_reg_validate(attr
->sample_regs_user
);
9641 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
9642 if (!arch_perf_have_user_stack_dump())
9646 * We have __u32 type for the size, but so far
9647 * we can only use __u16 as maximum due to the
9648 * __u16 sample size limit.
9650 if (attr
->sample_stack_user
>= USHRT_MAX
)
9652 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
9656 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
9657 ret
= perf_reg_validate(attr
->sample_regs_intr
);
9662 put_user(sizeof(*attr
), &uattr
->size
);
9668 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
9670 struct ring_buffer
*rb
= NULL
;
9676 /* don't allow circular references */
9677 if (event
== output_event
)
9681 * Don't allow cross-cpu buffers
9683 if (output_event
->cpu
!= event
->cpu
)
9687 * If its not a per-cpu rb, it must be the same task.
9689 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
9693 * Mixing clocks in the same buffer is trouble you don't need.
9695 if (output_event
->clock
!= event
->clock
)
9699 * Either writing ring buffer from beginning or from end.
9700 * Mixing is not allowed.
9702 if (is_write_backward(output_event
) != is_write_backward(event
))
9706 * If both events generate aux data, they must be on the same PMU
9708 if (has_aux(event
) && has_aux(output_event
) &&
9709 event
->pmu
!= output_event
->pmu
)
9713 mutex_lock(&event
->mmap_mutex
);
9714 /* Can't redirect output if we've got an active mmap() */
9715 if (atomic_read(&event
->mmap_count
))
9719 /* get the rb we want to redirect to */
9720 rb
= ring_buffer_get(output_event
);
9725 ring_buffer_attach(event
, rb
);
9729 mutex_unlock(&event
->mmap_mutex
);
9735 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
9741 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
9744 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
9746 bool nmi_safe
= false;
9749 case CLOCK_MONOTONIC
:
9750 event
->clock
= &ktime_get_mono_fast_ns
;
9754 case CLOCK_MONOTONIC_RAW
:
9755 event
->clock
= &ktime_get_raw_fast_ns
;
9759 case CLOCK_REALTIME
:
9760 event
->clock
= &ktime_get_real_ns
;
9763 case CLOCK_BOOTTIME
:
9764 event
->clock
= &ktime_get_boot_ns
;
9768 event
->clock
= &ktime_get_tai_ns
;
9775 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
9782 * Variation on perf_event_ctx_lock_nested(), except we take two context
9785 static struct perf_event_context
*
9786 __perf_event_ctx_lock_double(struct perf_event
*group_leader
,
9787 struct perf_event_context
*ctx
)
9789 struct perf_event_context
*gctx
;
9793 gctx
= READ_ONCE(group_leader
->ctx
);
9794 if (!atomic_inc_not_zero(&gctx
->refcount
)) {
9800 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
9802 if (group_leader
->ctx
!= gctx
) {
9803 mutex_unlock(&ctx
->mutex
);
9804 mutex_unlock(&gctx
->mutex
);
9813 * sys_perf_event_open - open a performance event, associate it to a task/cpu
9815 * @attr_uptr: event_id type attributes for monitoring/sampling
9818 * @group_fd: group leader event fd
9820 SYSCALL_DEFINE5(perf_event_open
,
9821 struct perf_event_attr __user
*, attr_uptr
,
9822 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
9824 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
9825 struct perf_event
*event
, *sibling
;
9826 struct perf_event_attr attr
;
9827 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
9828 struct file
*event_file
= NULL
;
9829 struct fd group
= {NULL
, 0};
9830 struct task_struct
*task
= NULL
;
9835 int f_flags
= O_RDWR
;
9838 /* for future expandability... */
9839 if (flags
& ~PERF_FLAG_ALL
)
9842 err
= perf_copy_attr(attr_uptr
, &attr
);
9846 if (!attr
.exclude_kernel
) {
9847 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
9851 if (attr
.namespaces
) {
9852 if (!capable(CAP_SYS_ADMIN
))
9857 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
9860 if (attr
.sample_period
& (1ULL << 63))
9864 if (!attr
.sample_max_stack
)
9865 attr
.sample_max_stack
= sysctl_perf_event_max_stack
;
9868 * In cgroup mode, the pid argument is used to pass the fd
9869 * opened to the cgroup directory in cgroupfs. The cpu argument
9870 * designates the cpu on which to monitor threads from that
9873 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
9876 if (flags
& PERF_FLAG_FD_CLOEXEC
)
9877 f_flags
|= O_CLOEXEC
;
9879 event_fd
= get_unused_fd_flags(f_flags
);
9883 if (group_fd
!= -1) {
9884 err
= perf_fget_light(group_fd
, &group
);
9887 group_leader
= group
.file
->private_data
;
9888 if (flags
& PERF_FLAG_FD_OUTPUT
)
9889 output_event
= group_leader
;
9890 if (flags
& PERF_FLAG_FD_NO_GROUP
)
9891 group_leader
= NULL
;
9894 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
9895 task
= find_lively_task_by_vpid(pid
);
9897 err
= PTR_ERR(task
);
9902 if (task
&& group_leader
&&
9903 group_leader
->attr
.inherit
!= attr
.inherit
) {
9909 err
= mutex_lock_interruptible(&task
->signal
->cred_guard_mutex
);
9914 * Reuse ptrace permission checks for now.
9916 * We must hold cred_guard_mutex across this and any potential
9917 * perf_install_in_context() call for this new event to
9918 * serialize against exec() altering our credentials (and the
9919 * perf_event_exit_task() that could imply).
9922 if (!ptrace_may_access(task
, PTRACE_MODE_READ_REALCREDS
))
9926 if (flags
& PERF_FLAG_PID_CGROUP
)
9929 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
9930 NULL
, NULL
, cgroup_fd
);
9931 if (IS_ERR(event
)) {
9932 err
= PTR_ERR(event
);
9936 if (is_sampling_event(event
)) {
9937 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
9944 * Special case software events and allow them to be part of
9945 * any hardware group.
9949 if (attr
.use_clockid
) {
9950 err
= perf_event_set_clock(event
, attr
.clockid
);
9955 if (pmu
->task_ctx_nr
== perf_sw_context
)
9956 event
->event_caps
|= PERF_EV_CAP_SOFTWARE
;
9959 (is_software_event(event
) != is_software_event(group_leader
))) {
9960 if (is_software_event(event
)) {
9962 * If event and group_leader are not both a software
9963 * event, and event is, then group leader is not.
9965 * Allow the addition of software events to !software
9966 * groups, this is safe because software events never
9969 pmu
= group_leader
->pmu
;
9970 } else if (is_software_event(group_leader
) &&
9971 (group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
9973 * In case the group is a pure software group, and we
9974 * try to add a hardware event, move the whole group to
9975 * the hardware context.
9982 * Get the target context (task or percpu):
9984 ctx
= find_get_context(pmu
, task
, event
);
9990 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
9996 * Look up the group leader (we will attach this event to it):
10002 * Do not allow a recursive hierarchy (this new sibling
10003 * becoming part of another group-sibling):
10005 if (group_leader
->group_leader
!= group_leader
)
10008 /* All events in a group should have the same clock */
10009 if (group_leader
->clock
!= event
->clock
)
10013 * Do not allow to attach to a group in a different
10014 * task or CPU context:
10018 * Make sure we're both on the same task, or both
10021 if (group_leader
->ctx
->task
!= ctx
->task
)
10025 * Make sure we're both events for the same CPU;
10026 * grouping events for different CPUs is broken; since
10027 * you can never concurrently schedule them anyhow.
10029 if (group_leader
->cpu
!= event
->cpu
)
10032 if (group_leader
->ctx
!= ctx
)
10037 * Only a group leader can be exclusive or pinned
10039 if (attr
.exclusive
|| attr
.pinned
)
10043 if (output_event
) {
10044 err
= perf_event_set_output(event
, output_event
);
10049 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
10051 if (IS_ERR(event_file
)) {
10052 err
= PTR_ERR(event_file
);
10058 gctx
= __perf_event_ctx_lock_double(group_leader
, ctx
);
10060 if (gctx
->task
== TASK_TOMBSTONE
) {
10066 * Check if we raced against another sys_perf_event_open() call
10067 * moving the software group underneath us.
10069 if (!(group_leader
->group_caps
& PERF_EV_CAP_SOFTWARE
)) {
10071 * If someone moved the group out from under us, check
10072 * if this new event wound up on the same ctx, if so
10073 * its the regular !move_group case, otherwise fail.
10079 perf_event_ctx_unlock(group_leader
, gctx
);
10084 mutex_lock(&ctx
->mutex
);
10087 if (ctx
->task
== TASK_TOMBSTONE
) {
10092 if (!perf_event_validate_size(event
)) {
10099 * Check if the @cpu we're creating an event for is online.
10101 * We use the perf_cpu_context::ctx::mutex to serialize against
10102 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10104 struct perf_cpu_context
*cpuctx
=
10105 container_of(ctx
, struct perf_cpu_context
, ctx
);
10107 if (!cpuctx
->online
) {
10115 * Must be under the same ctx::mutex as perf_install_in_context(),
10116 * because we need to serialize with concurrent event creation.
10118 if (!exclusive_event_installable(event
, ctx
)) {
10119 /* exclusive and group stuff are assumed mutually exclusive */
10120 WARN_ON_ONCE(move_group
);
10126 WARN_ON_ONCE(ctx
->parent_ctx
);
10129 * This is the point on no return; we cannot fail hereafter. This is
10130 * where we start modifying current state.
10135 * See perf_event_ctx_lock() for comments on the details
10136 * of swizzling perf_event::ctx.
10138 perf_remove_from_context(group_leader
, 0);
10141 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10143 perf_remove_from_context(sibling
, 0);
10148 * Wait for everybody to stop referencing the events through
10149 * the old lists, before installing it on new lists.
10154 * Install the group siblings before the group leader.
10156 * Because a group leader will try and install the entire group
10157 * (through the sibling list, which is still in-tact), we can
10158 * end up with siblings installed in the wrong context.
10160 * By installing siblings first we NO-OP because they're not
10161 * reachable through the group lists.
10163 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
10165 perf_event__state_init(sibling
);
10166 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
10171 * Removing from the context ends up with disabled
10172 * event. What we want here is event in the initial
10173 * startup state, ready to be add into new context.
10175 perf_event__state_init(group_leader
);
10176 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
10181 * Precalculate sample_data sizes; do while holding ctx::mutex such
10182 * that we're serialized against further additions and before
10183 * perf_install_in_context() which is the point the event is active and
10184 * can use these values.
10186 perf_event__header_size(event
);
10187 perf_event__id_header_size(event
);
10189 event
->owner
= current
;
10191 perf_install_in_context(ctx
, event
, event
->cpu
);
10192 perf_unpin_context(ctx
);
10195 perf_event_ctx_unlock(group_leader
, gctx
);
10196 mutex_unlock(&ctx
->mutex
);
10199 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10200 put_task_struct(task
);
10203 mutex_lock(¤t
->perf_event_mutex
);
10204 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
10205 mutex_unlock(¤t
->perf_event_mutex
);
10208 * Drop the reference on the group_event after placing the
10209 * new event on the sibling_list. This ensures destruction
10210 * of the group leader will find the pointer to itself in
10211 * perf_group_detach().
10214 fd_install(event_fd
, event_file
);
10219 perf_event_ctx_unlock(group_leader
, gctx
);
10220 mutex_unlock(&ctx
->mutex
);
10224 perf_unpin_context(ctx
);
10228 * If event_file is set, the fput() above will have called ->release()
10229 * and that will take care of freeing the event.
10235 mutex_unlock(&task
->signal
->cred_guard_mutex
);
10238 put_task_struct(task
);
10242 put_unused_fd(event_fd
);
10247 * perf_event_create_kernel_counter
10249 * @attr: attributes of the counter to create
10250 * @cpu: cpu in which the counter is bound
10251 * @task: task to profile (NULL for percpu)
10253 struct perf_event
*
10254 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
10255 struct task_struct
*task
,
10256 perf_overflow_handler_t overflow_handler
,
10259 struct perf_event_context
*ctx
;
10260 struct perf_event
*event
;
10264 * Get the target context (task or percpu):
10267 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
10268 overflow_handler
, context
, -1);
10269 if (IS_ERR(event
)) {
10270 err
= PTR_ERR(event
);
10274 /* Mark owner so we could distinguish it from user events. */
10275 event
->owner
= TASK_TOMBSTONE
;
10277 ctx
= find_get_context(event
->pmu
, task
, event
);
10279 err
= PTR_ERR(ctx
);
10283 WARN_ON_ONCE(ctx
->parent_ctx
);
10284 mutex_lock(&ctx
->mutex
);
10285 if (ctx
->task
== TASK_TOMBSTONE
) {
10292 * Check if the @cpu we're creating an event for is online.
10294 * We use the perf_cpu_context::ctx::mutex to serialize against
10295 * the hotplug notifiers. See perf_event_{init,exit}_cpu().
10297 struct perf_cpu_context
*cpuctx
=
10298 container_of(ctx
, struct perf_cpu_context
, ctx
);
10299 if (!cpuctx
->online
) {
10305 if (!exclusive_event_installable(event
, ctx
)) {
10310 perf_install_in_context(ctx
, event
, cpu
);
10311 perf_unpin_context(ctx
);
10312 mutex_unlock(&ctx
->mutex
);
10317 mutex_unlock(&ctx
->mutex
);
10318 perf_unpin_context(ctx
);
10323 return ERR_PTR(err
);
10325 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
10327 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
10329 struct perf_event_context
*src_ctx
;
10330 struct perf_event_context
*dst_ctx
;
10331 struct perf_event
*event
, *tmp
;
10334 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
10335 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
10338 * See perf_event_ctx_lock() for comments on the details
10339 * of swizzling perf_event::ctx.
10341 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
10342 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
10344 perf_remove_from_context(event
, 0);
10345 unaccount_event_cpu(event
, src_cpu
);
10347 list_add(&event
->migrate_entry
, &events
);
10351 * Wait for the events to quiesce before re-instating them.
10356 * Re-instate events in 2 passes.
10358 * Skip over group leaders and only install siblings on this first
10359 * pass, siblings will not get enabled without a leader, however a
10360 * leader will enable its siblings, even if those are still on the old
10363 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10364 if (event
->group_leader
== event
)
10367 list_del(&event
->migrate_entry
);
10368 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10369 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10370 account_event_cpu(event
, dst_cpu
);
10371 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10376 * Once all the siblings are setup properly, install the group leaders
10379 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
10380 list_del(&event
->migrate_entry
);
10381 if (event
->state
>= PERF_EVENT_STATE_OFF
)
10382 event
->state
= PERF_EVENT_STATE_INACTIVE
;
10383 account_event_cpu(event
, dst_cpu
);
10384 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
10387 mutex_unlock(&dst_ctx
->mutex
);
10388 mutex_unlock(&src_ctx
->mutex
);
10390 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
10392 static void sync_child_event(struct perf_event
*child_event
,
10393 struct task_struct
*child
)
10395 struct perf_event
*parent_event
= child_event
->parent
;
10398 if (child_event
->attr
.inherit_stat
)
10399 perf_event_read_event(child_event
, child
);
10401 child_val
= perf_event_count(child_event
);
10404 * Add back the child's count to the parent's count:
10406 atomic64_add(child_val
, &parent_event
->child_count
);
10407 atomic64_add(child_event
->total_time_enabled
,
10408 &parent_event
->child_total_time_enabled
);
10409 atomic64_add(child_event
->total_time_running
,
10410 &parent_event
->child_total_time_running
);
10414 perf_event_exit_event(struct perf_event
*child_event
,
10415 struct perf_event_context
*child_ctx
,
10416 struct task_struct
*child
)
10418 struct perf_event
*parent_event
= child_event
->parent
;
10421 * Do not destroy the 'original' grouping; because of the context
10422 * switch optimization the original events could've ended up in a
10423 * random child task.
10425 * If we were to destroy the original group, all group related
10426 * operations would cease to function properly after this random
10429 * Do destroy all inherited groups, we don't care about those
10430 * and being thorough is better.
10432 raw_spin_lock_irq(&child_ctx
->lock
);
10433 WARN_ON_ONCE(child_ctx
->is_active
);
10436 perf_group_detach(child_event
);
10437 list_del_event(child_event
, child_ctx
);
10438 child_event
->state
= PERF_EVENT_STATE_EXIT
; /* is_event_hup() */
10439 raw_spin_unlock_irq(&child_ctx
->lock
);
10442 * Parent events are governed by their filedesc, retain them.
10444 if (!parent_event
) {
10445 perf_event_wakeup(child_event
);
10449 * Child events can be cleaned up.
10452 sync_child_event(child_event
, child
);
10455 * Remove this event from the parent's list
10457 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
10458 mutex_lock(&parent_event
->child_mutex
);
10459 list_del_init(&child_event
->child_list
);
10460 mutex_unlock(&parent_event
->child_mutex
);
10463 * Kick perf_poll() for is_event_hup().
10465 perf_event_wakeup(parent_event
);
10466 free_event(child_event
);
10467 put_event(parent_event
);
10470 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
10472 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
10473 struct perf_event
*child_event
, *next
;
10475 WARN_ON_ONCE(child
!= current
);
10477 child_ctx
= perf_pin_task_context(child
, ctxn
);
10482 * In order to reduce the amount of tricky in ctx tear-down, we hold
10483 * ctx::mutex over the entire thing. This serializes against almost
10484 * everything that wants to access the ctx.
10486 * The exception is sys_perf_event_open() /
10487 * perf_event_create_kernel_count() which does find_get_context()
10488 * without ctx::mutex (it cannot because of the move_group double mutex
10489 * lock thing). See the comments in perf_install_in_context().
10491 mutex_lock(&child_ctx
->mutex
);
10494 * In a single ctx::lock section, de-schedule the events and detach the
10495 * context from the task such that we cannot ever get it scheduled back
10498 raw_spin_lock_irq(&child_ctx
->lock
);
10499 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
, EVENT_ALL
);
10502 * Now that the context is inactive, destroy the task <-> ctx relation
10503 * and mark the context dead.
10505 RCU_INIT_POINTER(child
->perf_event_ctxp
[ctxn
], NULL
);
10506 put_ctx(child_ctx
); /* cannot be last */
10507 WRITE_ONCE(child_ctx
->task
, TASK_TOMBSTONE
);
10508 put_task_struct(current
); /* cannot be last */
10510 clone_ctx
= unclone_ctx(child_ctx
);
10511 raw_spin_unlock_irq(&child_ctx
->lock
);
10514 put_ctx(clone_ctx
);
10517 * Report the task dead after unscheduling the events so that we
10518 * won't get any samples after PERF_RECORD_EXIT. We can however still
10519 * get a few PERF_RECORD_READ events.
10521 perf_event_task(child
, child_ctx
, 0);
10523 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
10524 perf_event_exit_event(child_event
, child_ctx
, child
);
10526 mutex_unlock(&child_ctx
->mutex
);
10528 put_ctx(child_ctx
);
10532 * When a child task exits, feed back event values to parent events.
10534 * Can be called with cred_guard_mutex held when called from
10535 * install_exec_creds().
10537 void perf_event_exit_task(struct task_struct
*child
)
10539 struct perf_event
*event
, *tmp
;
10542 mutex_lock(&child
->perf_event_mutex
);
10543 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
10545 list_del_init(&event
->owner_entry
);
10548 * Ensure the list deletion is visible before we clear
10549 * the owner, closes a race against perf_release() where
10550 * we need to serialize on the owner->perf_event_mutex.
10552 smp_store_release(&event
->owner
, NULL
);
10554 mutex_unlock(&child
->perf_event_mutex
);
10556 for_each_task_context_nr(ctxn
)
10557 perf_event_exit_task_context(child
, ctxn
);
10560 * The perf_event_exit_task_context calls perf_event_task
10561 * with child's task_ctx, which generates EXIT events for
10562 * child contexts and sets child->perf_event_ctxp[] to NULL.
10563 * At this point we need to send EXIT events to cpu contexts.
10565 perf_event_task(child
, NULL
, 0);
10568 static void perf_free_event(struct perf_event
*event
,
10569 struct perf_event_context
*ctx
)
10571 struct perf_event
*parent
= event
->parent
;
10573 if (WARN_ON_ONCE(!parent
))
10576 mutex_lock(&parent
->child_mutex
);
10577 list_del_init(&event
->child_list
);
10578 mutex_unlock(&parent
->child_mutex
);
10582 raw_spin_lock_irq(&ctx
->lock
);
10583 perf_group_detach(event
);
10584 list_del_event(event
, ctx
);
10585 raw_spin_unlock_irq(&ctx
->lock
);
10590 * Free an unexposed, unused context as created by inheritance by
10591 * perf_event_init_task below, used by fork() in case of fail.
10593 * Not all locks are strictly required, but take them anyway to be nice and
10594 * help out with the lockdep assertions.
10596 void perf_event_free_task(struct task_struct
*task
)
10598 struct perf_event_context
*ctx
;
10599 struct perf_event
*event
, *tmp
;
10602 for_each_task_context_nr(ctxn
) {
10603 ctx
= task
->perf_event_ctxp
[ctxn
];
10607 mutex_lock(&ctx
->mutex
);
10608 raw_spin_lock_irq(&ctx
->lock
);
10610 * Destroy the task <-> ctx relation and mark the context dead.
10612 * This is important because even though the task hasn't been
10613 * exposed yet the context has been (through child_list).
10615 RCU_INIT_POINTER(task
->perf_event_ctxp
[ctxn
], NULL
);
10616 WRITE_ONCE(ctx
->task
, TASK_TOMBSTONE
);
10617 put_task_struct(task
); /* cannot be last */
10618 raw_spin_unlock_irq(&ctx
->lock
);
10620 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
)
10621 perf_free_event(event
, ctx
);
10623 mutex_unlock(&ctx
->mutex
);
10628 void perf_event_delayed_put(struct task_struct
*task
)
10632 for_each_task_context_nr(ctxn
)
10633 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
10636 struct file
*perf_event_get(unsigned int fd
)
10640 file
= fget_raw(fd
);
10642 return ERR_PTR(-EBADF
);
10644 if (file
->f_op
!= &perf_fops
) {
10646 return ERR_PTR(-EBADF
);
10652 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
10655 return ERR_PTR(-EINVAL
);
10657 return &event
->attr
;
10661 * Inherit a event from parent task to child task.
10664 * - valid pointer on success
10665 * - NULL for orphaned events
10666 * - IS_ERR() on error
10668 static struct perf_event
*
10669 inherit_event(struct perf_event
*parent_event
,
10670 struct task_struct
*parent
,
10671 struct perf_event_context
*parent_ctx
,
10672 struct task_struct
*child
,
10673 struct perf_event
*group_leader
,
10674 struct perf_event_context
*child_ctx
)
10676 enum perf_event_active_state parent_state
= parent_event
->state
;
10677 struct perf_event
*child_event
;
10678 unsigned long flags
;
10681 * Instead of creating recursive hierarchies of events,
10682 * we link inherited events back to the original parent,
10683 * which has a filp for sure, which we use as the reference
10686 if (parent_event
->parent
)
10687 parent_event
= parent_event
->parent
;
10689 child_event
= perf_event_alloc(&parent_event
->attr
,
10692 group_leader
, parent_event
,
10694 if (IS_ERR(child_event
))
10695 return child_event
;
10698 * is_orphaned_event() and list_add_tail(&parent_event->child_list)
10699 * must be under the same lock in order to serialize against
10700 * perf_event_release_kernel(), such that either we must observe
10701 * is_orphaned_event() or they will observe us on the child_list.
10703 mutex_lock(&parent_event
->child_mutex
);
10704 if (is_orphaned_event(parent_event
) ||
10705 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
10706 mutex_unlock(&parent_event
->child_mutex
);
10707 free_event(child_event
);
10711 get_ctx(child_ctx
);
10714 * Make the child state follow the state of the parent event,
10715 * not its attr.disabled bit. We hold the parent's mutex,
10716 * so we won't race with perf_event_{en, dis}able_family.
10718 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
10719 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
10721 child_event
->state
= PERF_EVENT_STATE_OFF
;
10723 if (parent_event
->attr
.freq
) {
10724 u64 sample_period
= parent_event
->hw
.sample_period
;
10725 struct hw_perf_event
*hwc
= &child_event
->hw
;
10727 hwc
->sample_period
= sample_period
;
10728 hwc
->last_period
= sample_period
;
10730 local64_set(&hwc
->period_left
, sample_period
);
10733 child_event
->ctx
= child_ctx
;
10734 child_event
->overflow_handler
= parent_event
->overflow_handler
;
10735 child_event
->overflow_handler_context
10736 = parent_event
->overflow_handler_context
;
10739 * Precalculate sample_data sizes
10741 perf_event__header_size(child_event
);
10742 perf_event__id_header_size(child_event
);
10745 * Link it up in the child's context:
10747 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
10748 add_event_to_ctx(child_event
, child_ctx
);
10749 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
10752 * Link this into the parent event's child list
10754 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
10755 mutex_unlock(&parent_event
->child_mutex
);
10757 return child_event
;
10761 * Inherits an event group.
10763 * This will quietly suppress orphaned events; !inherit_event() is not an error.
10764 * This matches with perf_event_release_kernel() removing all child events.
10770 static int inherit_group(struct perf_event
*parent_event
,
10771 struct task_struct
*parent
,
10772 struct perf_event_context
*parent_ctx
,
10773 struct task_struct
*child
,
10774 struct perf_event_context
*child_ctx
)
10776 struct perf_event
*leader
;
10777 struct perf_event
*sub
;
10778 struct perf_event
*child_ctr
;
10780 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
10781 child
, NULL
, child_ctx
);
10782 if (IS_ERR(leader
))
10783 return PTR_ERR(leader
);
10785 * @leader can be NULL here because of is_orphaned_event(). In this
10786 * case inherit_event() will create individual events, similar to what
10787 * perf_group_detach() would do anyway.
10789 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
10790 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
10791 child
, leader
, child_ctx
);
10792 if (IS_ERR(child_ctr
))
10793 return PTR_ERR(child_ctr
);
10799 * Creates the child task context and tries to inherit the event-group.
10801 * Clears @inherited_all on !attr.inherited or error. Note that we'll leave
10802 * inherited_all set when we 'fail' to inherit an orphaned event; this is
10803 * consistent with perf_event_release_kernel() removing all child events.
10810 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
10811 struct perf_event_context
*parent_ctx
,
10812 struct task_struct
*child
, int ctxn
,
10813 int *inherited_all
)
10816 struct perf_event_context
*child_ctx
;
10818 if (!event
->attr
.inherit
) {
10819 *inherited_all
= 0;
10823 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10826 * This is executed from the parent task context, so
10827 * inherit events that have been marked for cloning.
10828 * First allocate and initialize a context for the
10831 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
10835 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
10838 ret
= inherit_group(event
, parent
, parent_ctx
,
10842 *inherited_all
= 0;
10848 * Initialize the perf_event context in task_struct
10850 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
10852 struct perf_event_context
*child_ctx
, *parent_ctx
;
10853 struct perf_event_context
*cloned_ctx
;
10854 struct perf_event
*event
;
10855 struct task_struct
*parent
= current
;
10856 int inherited_all
= 1;
10857 unsigned long flags
;
10860 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
10864 * If the parent's context is a clone, pin it so it won't get
10865 * swapped under us.
10867 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
10872 * No need to check if parent_ctx != NULL here; since we saw
10873 * it non-NULL earlier, the only reason for it to become NULL
10874 * is if we exit, and since we're currently in the middle of
10875 * a fork we can't be exiting at the same time.
10879 * Lock the parent list. No need to lock the child - not PID
10880 * hashed yet and not running, so nobody can access it.
10882 mutex_lock(&parent_ctx
->mutex
);
10885 * We dont have to disable NMIs - we are only looking at
10886 * the list, not manipulating it:
10888 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
10889 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10890 child
, ctxn
, &inherited_all
);
10896 * We can't hold ctx->lock when iterating the ->flexible_group list due
10897 * to allocations, but we need to prevent rotation because
10898 * rotate_ctx() will change the list from interrupt context.
10900 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10901 parent_ctx
->rotate_disable
= 1;
10902 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10904 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
10905 ret
= inherit_task_group(event
, parent
, parent_ctx
,
10906 child
, ctxn
, &inherited_all
);
10911 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
10912 parent_ctx
->rotate_disable
= 0;
10914 child_ctx
= child
->perf_event_ctxp
[ctxn
];
10916 if (child_ctx
&& inherited_all
) {
10918 * Mark the child context as a clone of the parent
10919 * context, or of whatever the parent is a clone of.
10921 * Note that if the parent is a clone, the holding of
10922 * parent_ctx->lock avoids it from being uncloned.
10924 cloned_ctx
= parent_ctx
->parent_ctx
;
10926 child_ctx
->parent_ctx
= cloned_ctx
;
10927 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
10929 child_ctx
->parent_ctx
= parent_ctx
;
10930 child_ctx
->parent_gen
= parent_ctx
->generation
;
10932 get_ctx(child_ctx
->parent_ctx
);
10935 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
10937 mutex_unlock(&parent_ctx
->mutex
);
10939 perf_unpin_context(parent_ctx
);
10940 put_ctx(parent_ctx
);
10946 * Initialize the perf_event context in task_struct
10948 int perf_event_init_task(struct task_struct
*child
)
10952 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
10953 mutex_init(&child
->perf_event_mutex
);
10954 INIT_LIST_HEAD(&child
->perf_event_list
);
10956 for_each_task_context_nr(ctxn
) {
10957 ret
= perf_event_init_context(child
, ctxn
);
10959 perf_event_free_task(child
);
10967 static void __init
perf_event_init_all_cpus(void)
10969 struct swevent_htable
*swhash
;
10972 zalloc_cpumask_var(&perf_online_mask
, GFP_KERNEL
);
10974 for_each_possible_cpu(cpu
) {
10975 swhash
= &per_cpu(swevent_htable
, cpu
);
10976 mutex_init(&swhash
->hlist_mutex
);
10977 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
10979 INIT_LIST_HEAD(&per_cpu(pmu_sb_events
.list
, cpu
));
10980 raw_spin_lock_init(&per_cpu(pmu_sb_events
.lock
, cpu
));
10982 #ifdef CONFIG_CGROUP_PERF
10983 INIT_LIST_HEAD(&per_cpu(cgrp_cpuctx_list
, cpu
));
10985 INIT_LIST_HEAD(&per_cpu(sched_cb_list
, cpu
));
10989 void perf_swevent_init_cpu(unsigned int cpu
)
10991 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
10993 mutex_lock(&swhash
->hlist_mutex
);
10994 if (swhash
->hlist_refcount
> 0 && !swevent_hlist_deref(swhash
)) {
10995 struct swevent_hlist
*hlist
;
10997 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
10999 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
11001 mutex_unlock(&swhash
->hlist_mutex
);
11004 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
11005 static void __perf_event_exit_context(void *__info
)
11007 struct perf_event_context
*ctx
= __info
;
11008 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
11009 struct perf_event
*event
;
11011 raw_spin_lock(&ctx
->lock
);
11012 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
11013 __perf_remove_from_context(event
, cpuctx
, ctx
, (void *)DETACH_GROUP
);
11014 raw_spin_unlock(&ctx
->lock
);
11017 static void perf_event_exit_cpu_context(int cpu
)
11019 struct perf_cpu_context
*cpuctx
;
11020 struct perf_event_context
*ctx
;
11023 mutex_lock(&pmus_lock
);
11024 list_for_each_entry(pmu
, &pmus
, entry
) {
11025 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11026 ctx
= &cpuctx
->ctx
;
11028 mutex_lock(&ctx
->mutex
);
11029 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
11030 cpuctx
->online
= 0;
11031 mutex_unlock(&ctx
->mutex
);
11033 cpumask_clear_cpu(cpu
, perf_online_mask
);
11034 mutex_unlock(&pmus_lock
);
11038 static void perf_event_exit_cpu_context(int cpu
) { }
11042 int perf_event_init_cpu(unsigned int cpu
)
11044 struct perf_cpu_context
*cpuctx
;
11045 struct perf_event_context
*ctx
;
11048 perf_swevent_init_cpu(cpu
);
11050 mutex_lock(&pmus_lock
);
11051 cpumask_set_cpu(cpu
, perf_online_mask
);
11052 list_for_each_entry(pmu
, &pmus
, entry
) {
11053 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
11054 ctx
= &cpuctx
->ctx
;
11056 mutex_lock(&ctx
->mutex
);
11057 cpuctx
->online
= 1;
11058 mutex_unlock(&ctx
->mutex
);
11060 mutex_unlock(&pmus_lock
);
11065 int perf_event_exit_cpu(unsigned int cpu
)
11067 perf_event_exit_cpu_context(cpu
);
11072 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
11076 for_each_online_cpu(cpu
)
11077 perf_event_exit_cpu(cpu
);
11083 * Run the perf reboot notifier at the very last possible moment so that
11084 * the generic watchdog code runs as long as possible.
11086 static struct notifier_block perf_reboot_notifier
= {
11087 .notifier_call
= perf_reboot
,
11088 .priority
= INT_MIN
,
11091 void __init
perf_event_init(void)
11095 idr_init(&pmu_idr
);
11097 perf_event_init_all_cpus();
11098 init_srcu_struct(&pmus_srcu
);
11099 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
11100 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
11101 perf_pmu_register(&perf_task_clock
, NULL
, -1);
11102 perf_tp_register();
11103 perf_event_init_cpu(smp_processor_id());
11104 register_reboot_notifier(&perf_reboot_notifier
);
11106 ret
= init_hw_breakpoint();
11107 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
11110 * Build time assertion that we keep the data_head at the intended
11111 * location. IOW, validation we got the __reserved[] size right.
11113 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
11117 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
11120 struct perf_pmu_events_attr
*pmu_attr
=
11121 container_of(attr
, struct perf_pmu_events_attr
, attr
);
11123 if (pmu_attr
->event_str
)
11124 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
11128 EXPORT_SYMBOL_GPL(perf_event_sysfs_show
);
11130 static int __init
perf_event_sysfs_init(void)
11135 mutex_lock(&pmus_lock
);
11137 ret
= bus_register(&pmu_bus
);
11141 list_for_each_entry(pmu
, &pmus
, entry
) {
11142 if (!pmu
->name
|| pmu
->type
< 0)
11145 ret
= pmu_dev_alloc(pmu
);
11146 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
11148 pmu_bus_running
= 1;
11152 mutex_unlock(&pmus_lock
);
11156 device_initcall(perf_event_sysfs_init
);
11158 #ifdef CONFIG_CGROUP_PERF
11159 static struct cgroup_subsys_state
*
11160 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
11162 struct perf_cgroup
*jc
;
11164 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
11166 return ERR_PTR(-ENOMEM
);
11168 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
11171 return ERR_PTR(-ENOMEM
);
11177 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
11179 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
11181 free_percpu(jc
->info
);
11185 static int __perf_cgroup_move(void *info
)
11187 struct task_struct
*task
= info
;
11189 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
11194 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
11196 struct task_struct
*task
;
11197 struct cgroup_subsys_state
*css
;
11199 cgroup_taskset_for_each(task
, css
, tset
)
11200 task_function_call(task
, __perf_cgroup_move
, task
);
11203 struct cgroup_subsys perf_event_cgrp_subsys
= {
11204 .css_alloc
= perf_cgroup_css_alloc
,
11205 .css_free
= perf_cgroup_css_free
,
11206 .attach
= perf_cgroup_attach
,
11208 * Implicitly enable on dfl hierarchy so that perf events can
11209 * always be filtered by cgroup2 path as long as perf_event
11210 * controller is not mounted on a legacy hierarchy.
11212 .implicit_on_dfl
= true,
11214 #endif /* CONFIG_CGROUP_PERF */