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>
50 #include <asm/irq_regs.h>
52 static struct workqueue_struct
*perf_wq
;
54 typedef int (*remote_function_f
)(void *);
56 struct remote_function_call
{
57 struct task_struct
*p
;
58 remote_function_f func
;
63 static void remote_function(void *data
)
65 struct remote_function_call
*tfc
= data
;
66 struct task_struct
*p
= tfc
->p
;
70 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
74 tfc
->ret
= tfc
->func(tfc
->info
);
78 * task_function_call - call a function on the cpu on which a task runs
79 * @p: the task to evaluate
80 * @func: the function to be called
81 * @info: the function call argument
83 * Calls the function @func when the task is currently running. This might
84 * be on the current CPU, which just calls the function directly
86 * returns: @func return value, or
87 * -ESRCH - when the process isn't running
88 * -EAGAIN - when the process moved away
91 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
93 struct remote_function_call data
= {
97 .ret
= -ESRCH
, /* No such (running) process */
101 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
107 * cpu_function_call - call a function on the cpu
108 * @func: the function to be called
109 * @info: the function call argument
111 * Calls the function @func on the remote cpu.
113 * returns: @func return value or -ENXIO when the cpu is offline
115 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
117 struct remote_function_call data
= {
121 .ret
= -ENXIO
, /* No such CPU */
124 smp_call_function_single(cpu
, remote_function
, &data
, 1);
129 static void event_function_call(struct perf_event
*event
,
130 int (*active
)(void *),
131 void (*inactive
)(void *),
134 struct perf_event_context
*ctx
= event
->ctx
;
135 struct task_struct
*task
= ctx
->task
;
138 cpu_function_call(event
->cpu
, active
, data
);
143 if (!task_function_call(task
, active
, data
))
146 raw_spin_lock_irq(&ctx
->lock
);
147 if (ctx
->is_active
) {
149 * Reload the task pointer, it might have been changed by
150 * a concurrent perf_event_context_sched_out().
153 raw_spin_unlock_irq(&ctx
->lock
);
157 raw_spin_unlock_irq(&ctx
->lock
);
160 #define EVENT_OWNER_KERNEL ((void *) -1)
162 static bool is_kernel_event(struct perf_event
*event
)
164 return event
->owner
== EVENT_OWNER_KERNEL
;
167 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
168 PERF_FLAG_FD_OUTPUT |\
169 PERF_FLAG_PID_CGROUP |\
170 PERF_FLAG_FD_CLOEXEC)
173 * branch priv levels that need permission checks
175 #define PERF_SAMPLE_BRANCH_PERM_PLM \
176 (PERF_SAMPLE_BRANCH_KERNEL |\
177 PERF_SAMPLE_BRANCH_HV)
180 EVENT_FLEXIBLE
= 0x1,
182 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
186 * perf_sched_events : >0 events exist
187 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
189 struct static_key_deferred perf_sched_events __read_mostly
;
190 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
191 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
193 static atomic_t nr_mmap_events __read_mostly
;
194 static atomic_t nr_comm_events __read_mostly
;
195 static atomic_t nr_task_events __read_mostly
;
196 static atomic_t nr_freq_events __read_mostly
;
197 static atomic_t nr_switch_events __read_mostly
;
199 static LIST_HEAD(pmus
);
200 static DEFINE_MUTEX(pmus_lock
);
201 static struct srcu_struct pmus_srcu
;
204 * perf event paranoia level:
205 * -1 - not paranoid at all
206 * 0 - disallow raw tracepoint access for unpriv
207 * 1 - disallow cpu events for unpriv
208 * 2 - disallow kernel profiling for unpriv
210 int sysctl_perf_event_paranoid __read_mostly
= 1;
212 /* Minimum for 512 kiB + 1 user control page */
213 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
216 * max perf event sample rate
218 #define DEFAULT_MAX_SAMPLE_RATE 100000
219 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
220 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
222 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
224 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
225 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
227 static int perf_sample_allowed_ns __read_mostly
=
228 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
230 static void update_perf_cpu_limits(void)
232 u64 tmp
= perf_sample_period_ns
;
234 tmp
*= sysctl_perf_cpu_time_max_percent
;
236 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
239 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
241 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
242 void __user
*buffer
, size_t *lenp
,
245 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
250 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
251 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
252 update_perf_cpu_limits();
257 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
259 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
260 void __user
*buffer
, size_t *lenp
,
263 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
268 update_perf_cpu_limits();
274 * perf samples are done in some very critical code paths (NMIs).
275 * If they take too much CPU time, the system can lock up and not
276 * get any real work done. This will drop the sample rate when
277 * we detect that events are taking too long.
279 #define NR_ACCUMULATED_SAMPLES 128
280 static DEFINE_PER_CPU(u64
, running_sample_length
);
282 static void perf_duration_warn(struct irq_work
*w
)
284 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
285 u64 avg_local_sample_len
;
286 u64 local_samples_len
;
288 local_samples_len
= __this_cpu_read(running_sample_length
);
289 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
291 printk_ratelimited(KERN_WARNING
292 "perf interrupt took too long (%lld > %lld), lowering "
293 "kernel.perf_event_max_sample_rate to %d\n",
294 avg_local_sample_len
, allowed_ns
>> 1,
295 sysctl_perf_event_sample_rate
);
298 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
300 void perf_sample_event_took(u64 sample_len_ns
)
302 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
303 u64 avg_local_sample_len
;
304 u64 local_samples_len
;
309 /* decay the counter by 1 average sample */
310 local_samples_len
= __this_cpu_read(running_sample_length
);
311 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
312 local_samples_len
+= sample_len_ns
;
313 __this_cpu_write(running_sample_length
, local_samples_len
);
316 * note: this will be biased artifically low until we have
317 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
318 * from having to maintain a count.
320 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
322 if (avg_local_sample_len
<= allowed_ns
)
325 if (max_samples_per_tick
<= 1)
328 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
329 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
330 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
332 update_perf_cpu_limits();
334 if (!irq_work_queue(&perf_duration_work
)) {
335 early_printk("perf interrupt took too long (%lld > %lld), lowering "
336 "kernel.perf_event_max_sample_rate to %d\n",
337 avg_local_sample_len
, allowed_ns
>> 1,
338 sysctl_perf_event_sample_rate
);
342 static atomic64_t perf_event_id
;
344 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
345 enum event_type_t event_type
);
347 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
348 enum event_type_t event_type
,
349 struct task_struct
*task
);
351 static void update_context_time(struct perf_event_context
*ctx
);
352 static u64
perf_event_time(struct perf_event
*event
);
354 void __weak
perf_event_print_debug(void) { }
356 extern __weak
const char *perf_pmu_name(void)
361 static inline u64
perf_clock(void)
363 return local_clock();
366 static inline u64
perf_event_clock(struct perf_event
*event
)
368 return event
->clock();
371 static inline struct perf_cpu_context
*
372 __get_cpu_context(struct perf_event_context
*ctx
)
374 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
377 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
378 struct perf_event_context
*ctx
)
380 raw_spin_lock(&cpuctx
->ctx
.lock
);
382 raw_spin_lock(&ctx
->lock
);
385 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
386 struct perf_event_context
*ctx
)
389 raw_spin_unlock(&ctx
->lock
);
390 raw_spin_unlock(&cpuctx
->ctx
.lock
);
393 #ifdef CONFIG_CGROUP_PERF
396 perf_cgroup_match(struct perf_event
*event
)
398 struct perf_event_context
*ctx
= event
->ctx
;
399 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
401 /* @event doesn't care about cgroup */
405 /* wants specific cgroup scope but @cpuctx isn't associated with any */
410 * Cgroup scoping is recursive. An event enabled for a cgroup is
411 * also enabled for all its descendant cgroups. If @cpuctx's
412 * cgroup is a descendant of @event's (the test covers identity
413 * case), it's a match.
415 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
416 event
->cgrp
->css
.cgroup
);
419 static inline void perf_detach_cgroup(struct perf_event
*event
)
421 css_put(&event
->cgrp
->css
);
425 static inline int is_cgroup_event(struct perf_event
*event
)
427 return event
->cgrp
!= NULL
;
430 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
432 struct perf_cgroup_info
*t
;
434 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
438 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
440 struct perf_cgroup_info
*info
;
445 info
= this_cpu_ptr(cgrp
->info
);
447 info
->time
+= now
- info
->timestamp
;
448 info
->timestamp
= now
;
451 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
453 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
455 __update_cgrp_time(cgrp_out
);
458 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
460 struct perf_cgroup
*cgrp
;
463 * ensure we access cgroup data only when needed and
464 * when we know the cgroup is pinned (css_get)
466 if (!is_cgroup_event(event
))
469 cgrp
= perf_cgroup_from_task(current
, event
->ctx
);
471 * Do not update time when cgroup is not active
473 if (cgrp
== event
->cgrp
)
474 __update_cgrp_time(event
->cgrp
);
478 perf_cgroup_set_timestamp(struct task_struct
*task
,
479 struct perf_event_context
*ctx
)
481 struct perf_cgroup
*cgrp
;
482 struct perf_cgroup_info
*info
;
485 * ctx->lock held by caller
486 * ensure we do not access cgroup data
487 * unless we have the cgroup pinned (css_get)
489 if (!task
|| !ctx
->nr_cgroups
)
492 cgrp
= perf_cgroup_from_task(task
, ctx
);
493 info
= this_cpu_ptr(cgrp
->info
);
494 info
->timestamp
= ctx
->timestamp
;
497 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
498 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
501 * reschedule events based on the cgroup constraint of task.
503 * mode SWOUT : schedule out everything
504 * mode SWIN : schedule in based on cgroup for next
506 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
508 struct perf_cpu_context
*cpuctx
;
513 * disable interrupts to avoid geting nr_cgroup
514 * changes via __perf_event_disable(). Also
517 local_irq_save(flags
);
520 * we reschedule only in the presence of cgroup
521 * constrained events.
524 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
525 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
526 if (cpuctx
->unique_pmu
!= pmu
)
527 continue; /* ensure we process each cpuctx once */
530 * perf_cgroup_events says at least one
531 * context on this CPU has cgroup events.
533 * ctx->nr_cgroups reports the number of cgroup
534 * events for a context.
536 if (cpuctx
->ctx
.nr_cgroups
> 0) {
537 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
538 perf_pmu_disable(cpuctx
->ctx
.pmu
);
540 if (mode
& PERF_CGROUP_SWOUT
) {
541 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
543 * must not be done before ctxswout due
544 * to event_filter_match() in event_sched_out()
549 if (mode
& PERF_CGROUP_SWIN
) {
550 WARN_ON_ONCE(cpuctx
->cgrp
);
552 * set cgrp before ctxsw in to allow
553 * event_filter_match() to not have to pass
555 * we pass the cpuctx->ctx to perf_cgroup_from_task()
556 * because cgorup events are only per-cpu
558 cpuctx
->cgrp
= perf_cgroup_from_task(task
, &cpuctx
->ctx
);
559 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
561 perf_pmu_enable(cpuctx
->ctx
.pmu
);
562 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
566 local_irq_restore(flags
);
569 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
570 struct task_struct
*next
)
572 struct perf_cgroup
*cgrp1
;
573 struct perf_cgroup
*cgrp2
= NULL
;
577 * we come here when we know perf_cgroup_events > 0
578 * we do not need to pass the ctx here because we know
579 * we are holding the rcu lock
581 cgrp1
= perf_cgroup_from_task(task
, NULL
);
584 * next is NULL when called from perf_event_enable_on_exec()
585 * that will systematically cause a cgroup_switch()
588 cgrp2
= perf_cgroup_from_task(next
, NULL
);
591 * only schedule out current cgroup events if we know
592 * that we are switching to a different cgroup. Otherwise,
593 * do no touch the cgroup events.
596 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
601 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
602 struct task_struct
*task
)
604 struct perf_cgroup
*cgrp1
;
605 struct perf_cgroup
*cgrp2
= NULL
;
609 * we come here when we know perf_cgroup_events > 0
610 * we do not need to pass the ctx here because we know
611 * we are holding the rcu lock
613 cgrp1
= perf_cgroup_from_task(task
, NULL
);
615 /* prev can never be NULL */
616 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
619 * only need to schedule in cgroup events if we are changing
620 * cgroup during ctxsw. Cgroup events were not scheduled
621 * out of ctxsw out if that was not the case.
624 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
629 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
630 struct perf_event_attr
*attr
,
631 struct perf_event
*group_leader
)
633 struct perf_cgroup
*cgrp
;
634 struct cgroup_subsys_state
*css
;
635 struct fd f
= fdget(fd
);
641 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
642 &perf_event_cgrp_subsys
);
648 cgrp
= container_of(css
, struct perf_cgroup
, css
);
652 * all events in a group must monitor
653 * the same cgroup because a task belongs
654 * to only one perf cgroup at a time
656 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
657 perf_detach_cgroup(event
);
666 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
668 struct perf_cgroup_info
*t
;
669 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
670 event
->shadow_ctx_time
= now
- t
->timestamp
;
674 perf_cgroup_defer_enabled(struct perf_event
*event
)
677 * when the current task's perf cgroup does not match
678 * the event's, we need to remember to call the
679 * perf_mark_enable() function the first time a task with
680 * a matching perf cgroup is scheduled in.
682 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
683 event
->cgrp_defer_enabled
= 1;
687 perf_cgroup_mark_enabled(struct perf_event
*event
,
688 struct perf_event_context
*ctx
)
690 struct perf_event
*sub
;
691 u64 tstamp
= perf_event_time(event
);
693 if (!event
->cgrp_defer_enabled
)
696 event
->cgrp_defer_enabled
= 0;
698 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
699 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
700 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
701 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
702 sub
->cgrp_defer_enabled
= 0;
706 #else /* !CONFIG_CGROUP_PERF */
709 perf_cgroup_match(struct perf_event
*event
)
714 static inline void perf_detach_cgroup(struct perf_event
*event
)
717 static inline int is_cgroup_event(struct perf_event
*event
)
722 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
727 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
731 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
735 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
736 struct task_struct
*next
)
740 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
741 struct task_struct
*task
)
745 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
746 struct perf_event_attr
*attr
,
747 struct perf_event
*group_leader
)
753 perf_cgroup_set_timestamp(struct task_struct
*task
,
754 struct perf_event_context
*ctx
)
759 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
764 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
768 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
774 perf_cgroup_defer_enabled(struct perf_event
*event
)
779 perf_cgroup_mark_enabled(struct perf_event
*event
,
780 struct perf_event_context
*ctx
)
786 * set default to be dependent on timer tick just
789 #define PERF_CPU_HRTIMER (1000 / HZ)
791 * function must be called with interrupts disbled
793 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
795 struct perf_cpu_context
*cpuctx
;
798 WARN_ON(!irqs_disabled());
800 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
801 rotations
= perf_rotate_context(cpuctx
);
803 raw_spin_lock(&cpuctx
->hrtimer_lock
);
805 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
807 cpuctx
->hrtimer_active
= 0;
808 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
810 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
813 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
815 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
816 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
819 /* no multiplexing needed for SW PMU */
820 if (pmu
->task_ctx_nr
== perf_sw_context
)
824 * check default is sane, if not set then force to
825 * default interval (1/tick)
827 interval
= pmu
->hrtimer_interval_ms
;
829 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
831 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
833 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
834 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
835 timer
->function
= perf_mux_hrtimer_handler
;
838 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
840 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
841 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
845 if (pmu
->task_ctx_nr
== perf_sw_context
)
848 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
849 if (!cpuctx
->hrtimer_active
) {
850 cpuctx
->hrtimer_active
= 1;
851 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
852 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
854 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
859 void perf_pmu_disable(struct pmu
*pmu
)
861 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
863 pmu
->pmu_disable(pmu
);
866 void perf_pmu_enable(struct pmu
*pmu
)
868 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
870 pmu
->pmu_enable(pmu
);
873 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
876 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
877 * perf_event_task_tick() are fully serialized because they're strictly cpu
878 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
879 * disabled, while perf_event_task_tick is called from IRQ context.
881 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
883 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
885 WARN_ON(!irqs_disabled());
887 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
889 list_add(&ctx
->active_ctx_list
, head
);
892 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
894 WARN_ON(!irqs_disabled());
896 WARN_ON(list_empty(&ctx
->active_ctx_list
));
898 list_del_init(&ctx
->active_ctx_list
);
901 static void get_ctx(struct perf_event_context
*ctx
)
903 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
906 static void free_ctx(struct rcu_head
*head
)
908 struct perf_event_context
*ctx
;
910 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
911 kfree(ctx
->task_ctx_data
);
915 static void put_ctx(struct perf_event_context
*ctx
)
917 if (atomic_dec_and_test(&ctx
->refcount
)) {
919 put_ctx(ctx
->parent_ctx
);
921 put_task_struct(ctx
->task
);
922 call_rcu(&ctx
->rcu_head
, free_ctx
);
927 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
928 * perf_pmu_migrate_context() we need some magic.
930 * Those places that change perf_event::ctx will hold both
931 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
933 * Lock ordering is by mutex address. There are two other sites where
934 * perf_event_context::mutex nests and those are:
936 * - perf_event_exit_task_context() [ child , 0 ]
937 * __perf_event_exit_task()
939 * put_event() [ parent, 1 ]
941 * - perf_event_init_context() [ parent, 0 ]
942 * inherit_task_group()
947 * perf_try_init_event() [ child , 1 ]
949 * While it appears there is an obvious deadlock here -- the parent and child
950 * nesting levels are inverted between the two. This is in fact safe because
951 * life-time rules separate them. That is an exiting task cannot fork, and a
952 * spawning task cannot (yet) exit.
954 * But remember that that these are parent<->child context relations, and
955 * migration does not affect children, therefore these two orderings should not
958 * The change in perf_event::ctx does not affect children (as claimed above)
959 * because the sys_perf_event_open() case will install a new event and break
960 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
961 * concerned with cpuctx and that doesn't have children.
963 * The places that change perf_event::ctx will issue:
965 * perf_remove_from_context();
967 * perf_install_in_context();
969 * to affect the change. The remove_from_context() + synchronize_rcu() should
970 * quiesce the event, after which we can install it in the new location. This
971 * means that only external vectors (perf_fops, prctl) can perturb the event
972 * while in transit. Therefore all such accessors should also acquire
973 * perf_event_context::mutex to serialize against this.
975 * However; because event->ctx can change while we're waiting to acquire
976 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
980 * task_struct::perf_event_mutex
981 * perf_event_context::mutex
982 * perf_event_context::lock
983 * perf_event::child_mutex;
984 * perf_event::mmap_mutex
987 static struct perf_event_context
*
988 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
990 struct perf_event_context
*ctx
;
994 ctx
= ACCESS_ONCE(event
->ctx
);
995 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1001 mutex_lock_nested(&ctx
->mutex
, nesting
);
1002 if (event
->ctx
!= ctx
) {
1003 mutex_unlock(&ctx
->mutex
);
1011 static inline struct perf_event_context
*
1012 perf_event_ctx_lock(struct perf_event
*event
)
1014 return perf_event_ctx_lock_nested(event
, 0);
1017 static void perf_event_ctx_unlock(struct perf_event
*event
,
1018 struct perf_event_context
*ctx
)
1020 mutex_unlock(&ctx
->mutex
);
1025 * This must be done under the ctx->lock, such as to serialize against
1026 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1027 * calling scheduler related locks and ctx->lock nests inside those.
1029 static __must_check
struct perf_event_context
*
1030 unclone_ctx(struct perf_event_context
*ctx
)
1032 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1034 lockdep_assert_held(&ctx
->lock
);
1037 ctx
->parent_ctx
= NULL
;
1043 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1046 * only top level events have the pid namespace they were created in
1049 event
= event
->parent
;
1051 return task_tgid_nr_ns(p
, event
->ns
);
1054 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1057 * only top level events have the pid namespace they were created in
1060 event
= event
->parent
;
1062 return task_pid_nr_ns(p
, event
->ns
);
1066 * If we inherit events we want to return the parent event id
1069 static u64
primary_event_id(struct perf_event
*event
)
1074 id
= event
->parent
->id
;
1080 * Get the perf_event_context for a task and lock it.
1081 * This has to cope with with the fact that until it is locked,
1082 * the context could get moved to another task.
1084 static struct perf_event_context
*
1085 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1087 struct perf_event_context
*ctx
;
1091 * One of the few rules of preemptible RCU is that one cannot do
1092 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1093 * part of the read side critical section was irqs-enabled -- see
1094 * rcu_read_unlock_special().
1096 * Since ctx->lock nests under rq->lock we must ensure the entire read
1097 * side critical section has interrupts disabled.
1099 local_irq_save(*flags
);
1101 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1104 * If this context is a clone of another, it might
1105 * get swapped for another underneath us by
1106 * perf_event_task_sched_out, though the
1107 * rcu_read_lock() protects us from any context
1108 * getting freed. Lock the context and check if it
1109 * got swapped before we could get the lock, and retry
1110 * if so. If we locked the right context, then it
1111 * can't get swapped on us any more.
1113 raw_spin_lock(&ctx
->lock
);
1114 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1115 raw_spin_unlock(&ctx
->lock
);
1117 local_irq_restore(*flags
);
1121 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1122 raw_spin_unlock(&ctx
->lock
);
1128 local_irq_restore(*flags
);
1133 * Get the context for a task and increment its pin_count so it
1134 * can't get swapped to another task. This also increments its
1135 * reference count so that the context can't get freed.
1137 static struct perf_event_context
*
1138 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1140 struct perf_event_context
*ctx
;
1141 unsigned long flags
;
1143 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1146 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1151 static void perf_unpin_context(struct perf_event_context
*ctx
)
1153 unsigned long flags
;
1155 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1157 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1161 * Update the record of the current time in a context.
1163 static void update_context_time(struct perf_event_context
*ctx
)
1165 u64 now
= perf_clock();
1167 ctx
->time
+= now
- ctx
->timestamp
;
1168 ctx
->timestamp
= now
;
1171 static u64
perf_event_time(struct perf_event
*event
)
1173 struct perf_event_context
*ctx
= event
->ctx
;
1175 if (is_cgroup_event(event
))
1176 return perf_cgroup_event_time(event
);
1178 return ctx
? ctx
->time
: 0;
1182 * Update the total_time_enabled and total_time_running fields for a event.
1183 * The caller of this function needs to hold the ctx->lock.
1185 static void update_event_times(struct perf_event
*event
)
1187 struct perf_event_context
*ctx
= event
->ctx
;
1190 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1191 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1194 * in cgroup mode, time_enabled represents
1195 * the time the event was enabled AND active
1196 * tasks were in the monitored cgroup. This is
1197 * independent of the activity of the context as
1198 * there may be a mix of cgroup and non-cgroup events.
1200 * That is why we treat cgroup events differently
1203 if (is_cgroup_event(event
))
1204 run_end
= perf_cgroup_event_time(event
);
1205 else if (ctx
->is_active
)
1206 run_end
= ctx
->time
;
1208 run_end
= event
->tstamp_stopped
;
1210 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1212 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1213 run_end
= event
->tstamp_stopped
;
1215 run_end
= perf_event_time(event
);
1217 event
->total_time_running
= run_end
- event
->tstamp_running
;
1222 * Update total_time_enabled and total_time_running for all events in a group.
1224 static void update_group_times(struct perf_event
*leader
)
1226 struct perf_event
*event
;
1228 update_event_times(leader
);
1229 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1230 update_event_times(event
);
1233 static struct list_head
*
1234 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1236 if (event
->attr
.pinned
)
1237 return &ctx
->pinned_groups
;
1239 return &ctx
->flexible_groups
;
1243 * Add a event from the lists for its context.
1244 * Must be called with ctx->mutex and ctx->lock held.
1247 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1249 lockdep_assert_held(&ctx
->lock
);
1251 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1252 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1255 * If we're a stand alone event or group leader, we go to the context
1256 * list, group events are kept attached to the group so that
1257 * perf_group_detach can, at all times, locate all siblings.
1259 if (event
->group_leader
== event
) {
1260 struct list_head
*list
;
1262 if (is_software_event(event
))
1263 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1265 list
= ctx_group_list(event
, ctx
);
1266 list_add_tail(&event
->group_entry
, list
);
1269 if (is_cgroup_event(event
))
1272 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1274 if (event
->attr
.inherit_stat
)
1281 * Initialize event state based on the perf_event_attr::disabled.
1283 static inline void perf_event__state_init(struct perf_event
*event
)
1285 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1286 PERF_EVENT_STATE_INACTIVE
;
1289 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1291 int entry
= sizeof(u64
); /* value */
1295 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1296 size
+= sizeof(u64
);
1298 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1299 size
+= sizeof(u64
);
1301 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1302 entry
+= sizeof(u64
);
1304 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1306 size
+= sizeof(u64
);
1310 event
->read_size
= size
;
1313 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1315 struct perf_sample_data
*data
;
1318 if (sample_type
& PERF_SAMPLE_IP
)
1319 size
+= sizeof(data
->ip
);
1321 if (sample_type
& PERF_SAMPLE_ADDR
)
1322 size
+= sizeof(data
->addr
);
1324 if (sample_type
& PERF_SAMPLE_PERIOD
)
1325 size
+= sizeof(data
->period
);
1327 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1328 size
+= sizeof(data
->weight
);
1330 if (sample_type
& PERF_SAMPLE_READ
)
1331 size
+= event
->read_size
;
1333 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1334 size
+= sizeof(data
->data_src
.val
);
1336 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1337 size
+= sizeof(data
->txn
);
1339 event
->header_size
= size
;
1343 * Called at perf_event creation and when events are attached/detached from a
1346 static void perf_event__header_size(struct perf_event
*event
)
1348 __perf_event_read_size(event
,
1349 event
->group_leader
->nr_siblings
);
1350 __perf_event_header_size(event
, event
->attr
.sample_type
);
1353 static void perf_event__id_header_size(struct perf_event
*event
)
1355 struct perf_sample_data
*data
;
1356 u64 sample_type
= event
->attr
.sample_type
;
1359 if (sample_type
& PERF_SAMPLE_TID
)
1360 size
+= sizeof(data
->tid_entry
);
1362 if (sample_type
& PERF_SAMPLE_TIME
)
1363 size
+= sizeof(data
->time
);
1365 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1366 size
+= sizeof(data
->id
);
1368 if (sample_type
& PERF_SAMPLE_ID
)
1369 size
+= sizeof(data
->id
);
1371 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1372 size
+= sizeof(data
->stream_id
);
1374 if (sample_type
& PERF_SAMPLE_CPU
)
1375 size
+= sizeof(data
->cpu_entry
);
1377 event
->id_header_size
= size
;
1380 static bool perf_event_validate_size(struct perf_event
*event
)
1383 * The values computed here will be over-written when we actually
1386 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1387 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1388 perf_event__id_header_size(event
);
1391 * Sum the lot; should not exceed the 64k limit we have on records.
1392 * Conservative limit to allow for callchains and other variable fields.
1394 if (event
->read_size
+ event
->header_size
+
1395 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1401 static void perf_group_attach(struct perf_event
*event
)
1403 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1406 * We can have double attach due to group movement in perf_event_open.
1408 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1411 event
->attach_state
|= PERF_ATTACH_GROUP
;
1413 if (group_leader
== event
)
1416 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1418 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1419 !is_software_event(event
))
1420 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1422 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1423 group_leader
->nr_siblings
++;
1425 perf_event__header_size(group_leader
);
1427 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1428 perf_event__header_size(pos
);
1432 * Remove a event from the lists for its context.
1433 * Must be called with ctx->mutex and ctx->lock held.
1436 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1438 struct perf_cpu_context
*cpuctx
;
1440 WARN_ON_ONCE(event
->ctx
!= ctx
);
1441 lockdep_assert_held(&ctx
->lock
);
1444 * We can have double detach due to exit/hot-unplug + close.
1446 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1449 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1451 if (is_cgroup_event(event
)) {
1453 cpuctx
= __get_cpu_context(ctx
);
1455 * if there are no more cgroup events
1456 * then cler cgrp to avoid stale pointer
1457 * in update_cgrp_time_from_cpuctx()
1459 if (!ctx
->nr_cgroups
)
1460 cpuctx
->cgrp
= NULL
;
1464 if (event
->attr
.inherit_stat
)
1467 list_del_rcu(&event
->event_entry
);
1469 if (event
->group_leader
== event
)
1470 list_del_init(&event
->group_entry
);
1472 update_group_times(event
);
1475 * If event was in error state, then keep it
1476 * that way, otherwise bogus counts will be
1477 * returned on read(). The only way to get out
1478 * of error state is by explicit re-enabling
1481 if (event
->state
> PERF_EVENT_STATE_OFF
)
1482 event
->state
= PERF_EVENT_STATE_OFF
;
1487 static void perf_group_detach(struct perf_event
*event
)
1489 struct perf_event
*sibling
, *tmp
;
1490 struct list_head
*list
= NULL
;
1493 * We can have double detach due to exit/hot-unplug + close.
1495 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1498 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1501 * If this is a sibling, remove it from its group.
1503 if (event
->group_leader
!= event
) {
1504 list_del_init(&event
->group_entry
);
1505 event
->group_leader
->nr_siblings
--;
1509 if (!list_empty(&event
->group_entry
))
1510 list
= &event
->group_entry
;
1513 * If this was a group event with sibling events then
1514 * upgrade the siblings to singleton events by adding them
1515 * to whatever list we are on.
1517 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1519 list_move_tail(&sibling
->group_entry
, list
);
1520 sibling
->group_leader
= sibling
;
1522 /* Inherit group flags from the previous leader */
1523 sibling
->group_flags
= event
->group_flags
;
1525 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1529 perf_event__header_size(event
->group_leader
);
1531 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1532 perf_event__header_size(tmp
);
1536 * User event without the task.
1538 static bool is_orphaned_event(struct perf_event
*event
)
1540 return event
&& !is_kernel_event(event
) && !event
->owner
;
1544 * Event has a parent but parent's task finished and it's
1545 * alive only because of children holding refference.
1547 static bool is_orphaned_child(struct perf_event
*event
)
1549 return is_orphaned_event(event
->parent
);
1552 static void orphans_remove_work(struct work_struct
*work
);
1554 static void schedule_orphans_remove(struct perf_event_context
*ctx
)
1556 if (!ctx
->task
|| ctx
->orphans_remove_sched
|| !perf_wq
)
1559 if (queue_delayed_work(perf_wq
, &ctx
->orphans_remove
, 1)) {
1561 ctx
->orphans_remove_sched
= true;
1565 static int __init
perf_workqueue_init(void)
1567 perf_wq
= create_singlethread_workqueue("perf");
1568 WARN(!perf_wq
, "failed to create perf workqueue\n");
1569 return perf_wq
? 0 : -1;
1572 core_initcall(perf_workqueue_init
);
1574 static inline int pmu_filter_match(struct perf_event
*event
)
1576 struct pmu
*pmu
= event
->pmu
;
1577 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1581 event_filter_match(struct perf_event
*event
)
1583 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1584 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1588 event_sched_out(struct perf_event
*event
,
1589 struct perf_cpu_context
*cpuctx
,
1590 struct perf_event_context
*ctx
)
1592 u64 tstamp
= perf_event_time(event
);
1595 WARN_ON_ONCE(event
->ctx
!= ctx
);
1596 lockdep_assert_held(&ctx
->lock
);
1599 * An event which could not be activated because of
1600 * filter mismatch still needs to have its timings
1601 * maintained, otherwise bogus information is return
1602 * via read() for time_enabled, time_running:
1604 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1605 && !event_filter_match(event
)) {
1606 delta
= tstamp
- event
->tstamp_stopped
;
1607 event
->tstamp_running
+= delta
;
1608 event
->tstamp_stopped
= tstamp
;
1611 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1614 perf_pmu_disable(event
->pmu
);
1616 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1617 if (event
->pending_disable
) {
1618 event
->pending_disable
= 0;
1619 event
->state
= PERF_EVENT_STATE_OFF
;
1621 event
->tstamp_stopped
= tstamp
;
1622 event
->pmu
->del(event
, 0);
1625 if (!is_software_event(event
))
1626 cpuctx
->active_oncpu
--;
1627 if (!--ctx
->nr_active
)
1628 perf_event_ctx_deactivate(ctx
);
1629 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1631 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1632 cpuctx
->exclusive
= 0;
1634 if (is_orphaned_child(event
))
1635 schedule_orphans_remove(ctx
);
1637 perf_pmu_enable(event
->pmu
);
1641 group_sched_out(struct perf_event
*group_event
,
1642 struct perf_cpu_context
*cpuctx
,
1643 struct perf_event_context
*ctx
)
1645 struct perf_event
*event
;
1646 int state
= group_event
->state
;
1648 event_sched_out(group_event
, cpuctx
, ctx
);
1651 * Schedule out siblings (if any):
1653 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1654 event_sched_out(event
, cpuctx
, ctx
);
1656 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1657 cpuctx
->exclusive
= 0;
1660 struct remove_event
{
1661 struct perf_event
*event
;
1665 static void ___perf_remove_from_context(void *info
)
1667 struct remove_event
*re
= info
;
1668 struct perf_event
*event
= re
->event
;
1669 struct perf_event_context
*ctx
= event
->ctx
;
1671 if (re
->detach_group
)
1672 perf_group_detach(event
);
1673 list_del_event(event
, ctx
);
1677 * Cross CPU call to remove a performance event
1679 * We disable the event on the hardware level first. After that we
1680 * remove it from the context list.
1682 static int __perf_remove_from_context(void *info
)
1684 struct remove_event
*re
= info
;
1685 struct perf_event
*event
= re
->event
;
1686 struct perf_event_context
*ctx
= event
->ctx
;
1687 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1689 raw_spin_lock(&ctx
->lock
);
1690 event_sched_out(event
, cpuctx
, ctx
);
1691 if (re
->detach_group
)
1692 perf_group_detach(event
);
1693 list_del_event(event
, ctx
);
1694 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1696 cpuctx
->task_ctx
= NULL
;
1698 raw_spin_unlock(&ctx
->lock
);
1704 * Remove the event from a task's (or a CPU's) list of events.
1706 * CPU events are removed with a smp call. For task events we only
1707 * call when the task is on a CPU.
1709 * If event->ctx is a cloned context, callers must make sure that
1710 * every task struct that event->ctx->task could possibly point to
1711 * remains valid. This is OK when called from perf_release since
1712 * that only calls us on the top-level context, which can't be a clone.
1713 * When called from perf_event_exit_task, it's OK because the
1714 * context has been detached from its task.
1716 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1718 struct perf_event_context
*ctx
= event
->ctx
;
1719 struct remove_event re
= {
1721 .detach_group
= detach_group
,
1724 lockdep_assert_held(&ctx
->mutex
);
1726 event_function_call(event
, __perf_remove_from_context
,
1727 ___perf_remove_from_context
, &re
);
1731 * Cross CPU call to disable a performance event
1733 int __perf_event_disable(void *info
)
1735 struct perf_event
*event
= info
;
1736 struct perf_event_context
*ctx
= event
->ctx
;
1737 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1740 * If this is a per-task event, need to check whether this
1741 * event's task is the current task on this cpu.
1743 * Can trigger due to concurrent perf_event_context_sched_out()
1744 * flipping contexts around.
1746 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1749 raw_spin_lock(&ctx
->lock
);
1752 * If the event is on, turn it off.
1753 * If it is in error state, leave it in error state.
1755 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1756 update_context_time(ctx
);
1757 update_cgrp_time_from_event(event
);
1758 update_group_times(event
);
1759 if (event
== event
->group_leader
)
1760 group_sched_out(event
, cpuctx
, ctx
);
1762 event_sched_out(event
, cpuctx
, ctx
);
1763 event
->state
= PERF_EVENT_STATE_OFF
;
1766 raw_spin_unlock(&ctx
->lock
);
1771 void ___perf_event_disable(void *info
)
1773 struct perf_event
*event
= info
;
1776 * Since we have the lock this context can't be scheduled
1777 * in, so we can change the state safely.
1779 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1780 update_group_times(event
);
1781 event
->state
= PERF_EVENT_STATE_OFF
;
1788 * If event->ctx is a cloned context, callers must make sure that
1789 * every task struct that event->ctx->task could possibly point to
1790 * remains valid. This condition is satisifed when called through
1791 * perf_event_for_each_child or perf_event_for_each because they
1792 * hold the top-level event's child_mutex, so any descendant that
1793 * goes to exit will block in sync_child_event.
1794 * When called from perf_pending_event it's OK because event->ctx
1795 * is the current context on this CPU and preemption is disabled,
1796 * hence we can't get into perf_event_task_sched_out for this context.
1798 static void _perf_event_disable(struct perf_event
*event
)
1800 struct perf_event_context
*ctx
= event
->ctx
;
1802 raw_spin_lock_irq(&ctx
->lock
);
1803 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1804 raw_spin_unlock_irq(&ctx
->lock
);
1807 raw_spin_unlock_irq(&ctx
->lock
);
1809 event_function_call(event
, __perf_event_disable
,
1810 ___perf_event_disable
, event
);
1814 * Strictly speaking kernel users cannot create groups and therefore this
1815 * interface does not need the perf_event_ctx_lock() magic.
1817 void perf_event_disable(struct perf_event
*event
)
1819 struct perf_event_context
*ctx
;
1821 ctx
= perf_event_ctx_lock(event
);
1822 _perf_event_disable(event
);
1823 perf_event_ctx_unlock(event
, ctx
);
1825 EXPORT_SYMBOL_GPL(perf_event_disable
);
1827 static void perf_set_shadow_time(struct perf_event
*event
,
1828 struct perf_event_context
*ctx
,
1832 * use the correct time source for the time snapshot
1834 * We could get by without this by leveraging the
1835 * fact that to get to this function, the caller
1836 * has most likely already called update_context_time()
1837 * and update_cgrp_time_xx() and thus both timestamp
1838 * are identical (or very close). Given that tstamp is,
1839 * already adjusted for cgroup, we could say that:
1840 * tstamp - ctx->timestamp
1842 * tstamp - cgrp->timestamp.
1844 * Then, in perf_output_read(), the calculation would
1845 * work with no changes because:
1846 * - event is guaranteed scheduled in
1847 * - no scheduled out in between
1848 * - thus the timestamp would be the same
1850 * But this is a bit hairy.
1852 * So instead, we have an explicit cgroup call to remain
1853 * within the time time source all along. We believe it
1854 * is cleaner and simpler to understand.
1856 if (is_cgroup_event(event
))
1857 perf_cgroup_set_shadow_time(event
, tstamp
);
1859 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1862 #define MAX_INTERRUPTS (~0ULL)
1864 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1865 static void perf_log_itrace_start(struct perf_event
*event
);
1868 event_sched_in(struct perf_event
*event
,
1869 struct perf_cpu_context
*cpuctx
,
1870 struct perf_event_context
*ctx
)
1872 u64 tstamp
= perf_event_time(event
);
1875 lockdep_assert_held(&ctx
->lock
);
1877 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1880 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1881 event
->oncpu
= smp_processor_id();
1884 * Unthrottle events, since we scheduled we might have missed several
1885 * ticks already, also for a heavily scheduling task there is little
1886 * guarantee it'll get a tick in a timely manner.
1888 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1889 perf_log_throttle(event
, 1);
1890 event
->hw
.interrupts
= 0;
1894 * The new state must be visible before we turn it on in the hardware:
1898 perf_pmu_disable(event
->pmu
);
1900 perf_set_shadow_time(event
, ctx
, tstamp
);
1902 perf_log_itrace_start(event
);
1904 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1905 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1911 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1913 if (!is_software_event(event
))
1914 cpuctx
->active_oncpu
++;
1915 if (!ctx
->nr_active
++)
1916 perf_event_ctx_activate(ctx
);
1917 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1920 if (event
->attr
.exclusive
)
1921 cpuctx
->exclusive
= 1;
1923 if (is_orphaned_child(event
))
1924 schedule_orphans_remove(ctx
);
1927 perf_pmu_enable(event
->pmu
);
1933 group_sched_in(struct perf_event
*group_event
,
1934 struct perf_cpu_context
*cpuctx
,
1935 struct perf_event_context
*ctx
)
1937 struct perf_event
*event
, *partial_group
= NULL
;
1938 struct pmu
*pmu
= ctx
->pmu
;
1939 u64 now
= ctx
->time
;
1940 bool simulate
= false;
1942 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1945 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
1947 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1948 pmu
->cancel_txn(pmu
);
1949 perf_mux_hrtimer_restart(cpuctx
);
1954 * Schedule in siblings as one group (if any):
1956 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1957 if (event_sched_in(event
, cpuctx
, ctx
)) {
1958 partial_group
= event
;
1963 if (!pmu
->commit_txn(pmu
))
1968 * Groups can be scheduled in as one unit only, so undo any
1969 * partial group before returning:
1970 * The events up to the failed event are scheduled out normally,
1971 * tstamp_stopped will be updated.
1973 * The failed events and the remaining siblings need to have
1974 * their timings updated as if they had gone thru event_sched_in()
1975 * and event_sched_out(). This is required to get consistent timings
1976 * across the group. This also takes care of the case where the group
1977 * could never be scheduled by ensuring tstamp_stopped is set to mark
1978 * the time the event was actually stopped, such that time delta
1979 * calculation in update_event_times() is correct.
1981 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1982 if (event
== partial_group
)
1986 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1987 event
->tstamp_stopped
= now
;
1989 event_sched_out(event
, cpuctx
, ctx
);
1992 event_sched_out(group_event
, cpuctx
, ctx
);
1994 pmu
->cancel_txn(pmu
);
1996 perf_mux_hrtimer_restart(cpuctx
);
2002 * Work out whether we can put this event group on the CPU now.
2004 static int group_can_go_on(struct perf_event
*event
,
2005 struct perf_cpu_context
*cpuctx
,
2009 * Groups consisting entirely of software events can always go on.
2011 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2014 * If an exclusive group is already on, no other hardware
2017 if (cpuctx
->exclusive
)
2020 * If this group is exclusive and there are already
2021 * events on the CPU, it can't go on.
2023 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2026 * Otherwise, try to add it if all previous groups were able
2032 static void add_event_to_ctx(struct perf_event
*event
,
2033 struct perf_event_context
*ctx
)
2035 u64 tstamp
= perf_event_time(event
);
2037 list_add_event(event
, ctx
);
2038 perf_group_attach(event
);
2039 event
->tstamp_enabled
= tstamp
;
2040 event
->tstamp_running
= tstamp
;
2041 event
->tstamp_stopped
= tstamp
;
2044 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
2046 ctx_sched_in(struct perf_event_context
*ctx
,
2047 struct perf_cpu_context
*cpuctx
,
2048 enum event_type_t event_type
,
2049 struct task_struct
*task
);
2051 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2052 struct perf_event_context
*ctx
,
2053 struct task_struct
*task
)
2055 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2057 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2058 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2060 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2063 static void ___perf_install_in_context(void *info
)
2065 struct perf_event
*event
= info
;
2066 struct perf_event_context
*ctx
= event
->ctx
;
2069 * Since the task isn't running, its safe to add the event, us holding
2070 * the ctx->lock ensures the task won't get scheduled in.
2072 add_event_to_ctx(event
, ctx
);
2076 * Cross CPU call to install and enable a performance event
2078 * Must be called with ctx->mutex held
2080 static int __perf_install_in_context(void *info
)
2082 struct perf_event
*event
= info
;
2083 struct perf_event_context
*ctx
= event
->ctx
;
2084 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2085 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2086 struct task_struct
*task
= current
;
2088 perf_ctx_lock(cpuctx
, task_ctx
);
2089 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2092 * If there was an active task_ctx schedule it out.
2095 task_ctx_sched_out(task_ctx
);
2098 * If the context we're installing events in is not the
2099 * active task_ctx, flip them.
2101 if (ctx
->task
&& task_ctx
!= ctx
) {
2103 raw_spin_unlock(&task_ctx
->lock
);
2104 raw_spin_lock(&ctx
->lock
);
2109 cpuctx
->task_ctx
= task_ctx
;
2110 task
= task_ctx
->task
;
2113 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2115 update_context_time(ctx
);
2117 * update cgrp time only if current cgrp
2118 * matches event->cgrp. Must be done before
2119 * calling add_event_to_ctx()
2121 update_cgrp_time_from_event(event
);
2123 add_event_to_ctx(event
, ctx
);
2126 * Schedule everything back in
2128 perf_event_sched_in(cpuctx
, task_ctx
, task
);
2130 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2131 perf_ctx_unlock(cpuctx
, task_ctx
);
2137 * Attach a performance event to a context
2139 * First we add the event to the list with the hardware enable bit
2140 * in event->hw_config cleared.
2142 * If the event is attached to a task which is on a CPU we use a smp
2143 * call to enable it in the task context. The task might have been
2144 * scheduled away, but we check this in the smp call again.
2147 perf_install_in_context(struct perf_event_context
*ctx
,
2148 struct perf_event
*event
,
2151 lockdep_assert_held(&ctx
->mutex
);
2154 if (event
->cpu
!= -1)
2157 event_function_call(event
, __perf_install_in_context
,
2158 ___perf_install_in_context
, event
);
2162 * Put a event into inactive state and update time fields.
2163 * Enabling the leader of a group effectively enables all
2164 * the group members that aren't explicitly disabled, so we
2165 * have to update their ->tstamp_enabled also.
2166 * Note: this works for group members as well as group leaders
2167 * since the non-leader members' sibling_lists will be empty.
2169 static void __perf_event_mark_enabled(struct perf_event
*event
)
2171 struct perf_event
*sub
;
2172 u64 tstamp
= perf_event_time(event
);
2174 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2175 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2176 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2177 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2178 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2183 * Cross CPU call to enable a performance event
2185 static int __perf_event_enable(void *info
)
2187 struct perf_event
*event
= info
;
2188 struct perf_event_context
*ctx
= event
->ctx
;
2189 struct perf_event
*leader
= event
->group_leader
;
2190 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2194 * There's a time window between 'ctx->is_active' check
2195 * in perf_event_enable function and this place having:
2197 * - ctx->lock unlocked
2199 * where the task could be killed and 'ctx' deactivated
2200 * by perf_event_exit_task.
2202 if (!ctx
->is_active
)
2205 raw_spin_lock(&ctx
->lock
);
2206 update_context_time(ctx
);
2208 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2212 * set current task's cgroup time reference point
2214 perf_cgroup_set_timestamp(current
, ctx
);
2216 __perf_event_mark_enabled(event
);
2218 if (!event_filter_match(event
)) {
2219 if (is_cgroup_event(event
))
2220 perf_cgroup_defer_enabled(event
);
2225 * If the event is in a group and isn't the group leader,
2226 * then don't put it on unless the group is on.
2228 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2231 if (!group_can_go_on(event
, cpuctx
, 1)) {
2234 if (event
== leader
)
2235 err
= group_sched_in(event
, cpuctx
, ctx
);
2237 err
= event_sched_in(event
, cpuctx
, ctx
);
2242 * If this event can't go on and it's part of a
2243 * group, then the whole group has to come off.
2245 if (leader
!= event
) {
2246 group_sched_out(leader
, cpuctx
, ctx
);
2247 perf_mux_hrtimer_restart(cpuctx
);
2249 if (leader
->attr
.pinned
) {
2250 update_group_times(leader
);
2251 leader
->state
= PERF_EVENT_STATE_ERROR
;
2256 raw_spin_unlock(&ctx
->lock
);
2261 void ___perf_event_enable(void *info
)
2263 __perf_event_mark_enabled((struct perf_event
*)info
);
2269 * If event->ctx is a cloned context, callers must make sure that
2270 * every task struct that event->ctx->task could possibly point to
2271 * remains valid. This condition is satisfied when called through
2272 * perf_event_for_each_child or perf_event_for_each as described
2273 * for perf_event_disable.
2275 static void _perf_event_enable(struct perf_event
*event
)
2277 struct perf_event_context
*ctx
= event
->ctx
;
2279 raw_spin_lock_irq(&ctx
->lock
);
2280 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
2281 raw_spin_unlock_irq(&ctx
->lock
);
2286 * If the event is in error state, clear that first.
2288 * That way, if we see the event in error state below, we know that it
2289 * has gone back into error state, as distinct from the task having
2290 * been scheduled away before the cross-call arrived.
2292 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2293 event
->state
= PERF_EVENT_STATE_OFF
;
2294 raw_spin_unlock_irq(&ctx
->lock
);
2296 event_function_call(event
, __perf_event_enable
,
2297 ___perf_event_enable
, event
);
2301 * See perf_event_disable();
2303 void perf_event_enable(struct perf_event
*event
)
2305 struct perf_event_context
*ctx
;
2307 ctx
= perf_event_ctx_lock(event
);
2308 _perf_event_enable(event
);
2309 perf_event_ctx_unlock(event
, ctx
);
2311 EXPORT_SYMBOL_GPL(perf_event_enable
);
2313 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2316 * not supported on inherited events
2318 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2321 atomic_add(refresh
, &event
->event_limit
);
2322 _perf_event_enable(event
);
2328 * See perf_event_disable()
2330 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2332 struct perf_event_context
*ctx
;
2335 ctx
= perf_event_ctx_lock(event
);
2336 ret
= _perf_event_refresh(event
, refresh
);
2337 perf_event_ctx_unlock(event
, ctx
);
2341 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2343 static void ctx_sched_out(struct perf_event_context
*ctx
,
2344 struct perf_cpu_context
*cpuctx
,
2345 enum event_type_t event_type
)
2347 int is_active
= ctx
->is_active
;
2348 struct perf_event
*event
;
2350 lockdep_assert_held(&ctx
->lock
);
2352 ctx
->is_active
&= ~event_type
;
2353 if (likely(!ctx
->nr_events
))
2356 update_context_time(ctx
);
2357 update_cgrp_time_from_cpuctx(cpuctx
);
2358 if (!ctx
->nr_active
)
2361 perf_pmu_disable(ctx
->pmu
);
2362 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2363 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2364 group_sched_out(event
, cpuctx
, ctx
);
2367 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2368 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2369 group_sched_out(event
, cpuctx
, ctx
);
2371 perf_pmu_enable(ctx
->pmu
);
2375 * Test whether two contexts are equivalent, i.e. whether they have both been
2376 * cloned from the same version of the same context.
2378 * Equivalence is measured using a generation number in the context that is
2379 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2380 * and list_del_event().
2382 static int context_equiv(struct perf_event_context
*ctx1
,
2383 struct perf_event_context
*ctx2
)
2385 lockdep_assert_held(&ctx1
->lock
);
2386 lockdep_assert_held(&ctx2
->lock
);
2388 /* Pinning disables the swap optimization */
2389 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2392 /* If ctx1 is the parent of ctx2 */
2393 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2396 /* If ctx2 is the parent of ctx1 */
2397 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2401 * If ctx1 and ctx2 have the same parent; we flatten the parent
2402 * hierarchy, see perf_event_init_context().
2404 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2405 ctx1
->parent_gen
== ctx2
->parent_gen
)
2412 static void __perf_event_sync_stat(struct perf_event
*event
,
2413 struct perf_event
*next_event
)
2417 if (!event
->attr
.inherit_stat
)
2421 * Update the event value, we cannot use perf_event_read()
2422 * because we're in the middle of a context switch and have IRQs
2423 * disabled, which upsets smp_call_function_single(), however
2424 * we know the event must be on the current CPU, therefore we
2425 * don't need to use it.
2427 switch (event
->state
) {
2428 case PERF_EVENT_STATE_ACTIVE
:
2429 event
->pmu
->read(event
);
2432 case PERF_EVENT_STATE_INACTIVE
:
2433 update_event_times(event
);
2441 * In order to keep per-task stats reliable we need to flip the event
2442 * values when we flip the contexts.
2444 value
= local64_read(&next_event
->count
);
2445 value
= local64_xchg(&event
->count
, value
);
2446 local64_set(&next_event
->count
, value
);
2448 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2449 swap(event
->total_time_running
, next_event
->total_time_running
);
2452 * Since we swizzled the values, update the user visible data too.
2454 perf_event_update_userpage(event
);
2455 perf_event_update_userpage(next_event
);
2458 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2459 struct perf_event_context
*next_ctx
)
2461 struct perf_event
*event
, *next_event
;
2466 update_context_time(ctx
);
2468 event
= list_first_entry(&ctx
->event_list
,
2469 struct perf_event
, event_entry
);
2471 next_event
= list_first_entry(&next_ctx
->event_list
,
2472 struct perf_event
, event_entry
);
2474 while (&event
->event_entry
!= &ctx
->event_list
&&
2475 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2477 __perf_event_sync_stat(event
, next_event
);
2479 event
= list_next_entry(event
, event_entry
);
2480 next_event
= list_next_entry(next_event
, event_entry
);
2484 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2485 struct task_struct
*next
)
2487 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2488 struct perf_event_context
*next_ctx
;
2489 struct perf_event_context
*parent
, *next_parent
;
2490 struct perf_cpu_context
*cpuctx
;
2496 cpuctx
= __get_cpu_context(ctx
);
2497 if (!cpuctx
->task_ctx
)
2501 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2505 parent
= rcu_dereference(ctx
->parent_ctx
);
2506 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2508 /* If neither context have a parent context; they cannot be clones. */
2509 if (!parent
&& !next_parent
)
2512 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2514 * Looks like the two contexts are clones, so we might be
2515 * able to optimize the context switch. We lock both
2516 * contexts and check that they are clones under the
2517 * lock (including re-checking that neither has been
2518 * uncloned in the meantime). It doesn't matter which
2519 * order we take the locks because no other cpu could
2520 * be trying to lock both of these tasks.
2522 raw_spin_lock(&ctx
->lock
);
2523 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2524 if (context_equiv(ctx
, next_ctx
)) {
2526 * XXX do we need a memory barrier of sorts
2527 * wrt to rcu_dereference() of perf_event_ctxp
2529 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2530 next
->perf_event_ctxp
[ctxn
] = ctx
;
2532 next_ctx
->task
= task
;
2534 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2538 perf_event_sync_stat(ctx
, next_ctx
);
2540 raw_spin_unlock(&next_ctx
->lock
);
2541 raw_spin_unlock(&ctx
->lock
);
2547 raw_spin_lock(&ctx
->lock
);
2548 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2549 cpuctx
->task_ctx
= NULL
;
2550 raw_spin_unlock(&ctx
->lock
);
2554 void perf_sched_cb_dec(struct pmu
*pmu
)
2556 this_cpu_dec(perf_sched_cb_usages
);
2559 void perf_sched_cb_inc(struct pmu
*pmu
)
2561 this_cpu_inc(perf_sched_cb_usages
);
2565 * This function provides the context switch callback to the lower code
2566 * layer. It is invoked ONLY when the context switch callback is enabled.
2568 static void perf_pmu_sched_task(struct task_struct
*prev
,
2569 struct task_struct
*next
,
2572 struct perf_cpu_context
*cpuctx
;
2574 unsigned long flags
;
2579 local_irq_save(flags
);
2583 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2584 if (pmu
->sched_task
) {
2585 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2587 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2589 perf_pmu_disable(pmu
);
2591 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2593 perf_pmu_enable(pmu
);
2595 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2601 local_irq_restore(flags
);
2604 static void perf_event_switch(struct task_struct
*task
,
2605 struct task_struct
*next_prev
, bool sched_in
);
2607 #define for_each_task_context_nr(ctxn) \
2608 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2611 * Called from scheduler to remove the events of the current task,
2612 * with interrupts disabled.
2614 * We stop each event and update the event value in event->count.
2616 * This does not protect us against NMI, but disable()
2617 * sets the disabled bit in the control field of event _before_
2618 * accessing the event control register. If a NMI hits, then it will
2619 * not restart the event.
2621 void __perf_event_task_sched_out(struct task_struct
*task
,
2622 struct task_struct
*next
)
2626 if (__this_cpu_read(perf_sched_cb_usages
))
2627 perf_pmu_sched_task(task
, next
, false);
2629 if (atomic_read(&nr_switch_events
))
2630 perf_event_switch(task
, next
, false);
2632 for_each_task_context_nr(ctxn
)
2633 perf_event_context_sched_out(task
, ctxn
, next
);
2636 * if cgroup events exist on this CPU, then we need
2637 * to check if we have to switch out PMU state.
2638 * cgroup event are system-wide mode only
2640 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2641 perf_cgroup_sched_out(task
, next
);
2644 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2646 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2648 if (!cpuctx
->task_ctx
)
2651 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2654 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2655 cpuctx
->task_ctx
= NULL
;
2659 * Called with IRQs disabled
2661 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2662 enum event_type_t event_type
)
2664 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2668 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2669 struct perf_cpu_context
*cpuctx
)
2671 struct perf_event
*event
;
2673 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2674 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2676 if (!event_filter_match(event
))
2679 /* may need to reset tstamp_enabled */
2680 if (is_cgroup_event(event
))
2681 perf_cgroup_mark_enabled(event
, ctx
);
2683 if (group_can_go_on(event
, cpuctx
, 1))
2684 group_sched_in(event
, cpuctx
, ctx
);
2687 * If this pinned group hasn't been scheduled,
2688 * put it in error state.
2690 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2691 update_group_times(event
);
2692 event
->state
= PERF_EVENT_STATE_ERROR
;
2698 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2699 struct perf_cpu_context
*cpuctx
)
2701 struct perf_event
*event
;
2704 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2705 /* Ignore events in OFF or ERROR state */
2706 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2709 * Listen to the 'cpu' scheduling filter constraint
2712 if (!event_filter_match(event
))
2715 /* may need to reset tstamp_enabled */
2716 if (is_cgroup_event(event
))
2717 perf_cgroup_mark_enabled(event
, ctx
);
2719 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2720 if (group_sched_in(event
, cpuctx
, ctx
))
2727 ctx_sched_in(struct perf_event_context
*ctx
,
2728 struct perf_cpu_context
*cpuctx
,
2729 enum event_type_t event_type
,
2730 struct task_struct
*task
)
2732 int is_active
= ctx
->is_active
;
2735 lockdep_assert_held(&ctx
->lock
);
2737 ctx
->is_active
|= event_type
;
2738 if (likely(!ctx
->nr_events
))
2742 ctx
->timestamp
= now
;
2743 perf_cgroup_set_timestamp(task
, ctx
);
2745 * First go through the list and put on any pinned groups
2746 * in order to give them the best chance of going on.
2748 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2749 ctx_pinned_sched_in(ctx
, cpuctx
);
2751 /* Then walk through the lower prio flexible groups */
2752 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2753 ctx_flexible_sched_in(ctx
, cpuctx
);
2756 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2757 enum event_type_t event_type
,
2758 struct task_struct
*task
)
2760 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2762 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2765 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2766 struct task_struct
*task
)
2768 struct perf_cpu_context
*cpuctx
;
2770 cpuctx
= __get_cpu_context(ctx
);
2771 if (cpuctx
->task_ctx
== ctx
)
2774 perf_ctx_lock(cpuctx
, ctx
);
2775 perf_pmu_disable(ctx
->pmu
);
2777 * We want to keep the following priority order:
2778 * cpu pinned (that don't need to move), task pinned,
2779 * cpu flexible, task flexible.
2781 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2784 cpuctx
->task_ctx
= ctx
;
2786 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2788 perf_pmu_enable(ctx
->pmu
);
2789 perf_ctx_unlock(cpuctx
, ctx
);
2793 * Called from scheduler to add the events of the current task
2794 * with interrupts disabled.
2796 * We restore the event value and then enable it.
2798 * This does not protect us against NMI, but enable()
2799 * sets the enabled bit in the control field of event _before_
2800 * accessing the event control register. If a NMI hits, then it will
2801 * keep the event running.
2803 void __perf_event_task_sched_in(struct task_struct
*prev
,
2804 struct task_struct
*task
)
2806 struct perf_event_context
*ctx
;
2809 for_each_task_context_nr(ctxn
) {
2810 ctx
= task
->perf_event_ctxp
[ctxn
];
2814 perf_event_context_sched_in(ctx
, task
);
2817 * if cgroup events exist on this CPU, then we need
2818 * to check if we have to switch in PMU state.
2819 * cgroup event are system-wide mode only
2821 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2822 perf_cgroup_sched_in(prev
, task
);
2824 if (atomic_read(&nr_switch_events
))
2825 perf_event_switch(task
, prev
, true);
2827 if (__this_cpu_read(perf_sched_cb_usages
))
2828 perf_pmu_sched_task(prev
, task
, true);
2831 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2833 u64 frequency
= event
->attr
.sample_freq
;
2834 u64 sec
= NSEC_PER_SEC
;
2835 u64 divisor
, dividend
;
2837 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2839 count_fls
= fls64(count
);
2840 nsec_fls
= fls64(nsec
);
2841 frequency_fls
= fls64(frequency
);
2845 * We got @count in @nsec, with a target of sample_freq HZ
2846 * the target period becomes:
2849 * period = -------------------
2850 * @nsec * sample_freq
2855 * Reduce accuracy by one bit such that @a and @b converge
2856 * to a similar magnitude.
2858 #define REDUCE_FLS(a, b) \
2860 if (a##_fls > b##_fls) { \
2870 * Reduce accuracy until either term fits in a u64, then proceed with
2871 * the other, so that finally we can do a u64/u64 division.
2873 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2874 REDUCE_FLS(nsec
, frequency
);
2875 REDUCE_FLS(sec
, count
);
2878 if (count_fls
+ sec_fls
> 64) {
2879 divisor
= nsec
* frequency
;
2881 while (count_fls
+ sec_fls
> 64) {
2882 REDUCE_FLS(count
, sec
);
2886 dividend
= count
* sec
;
2888 dividend
= count
* sec
;
2890 while (nsec_fls
+ frequency_fls
> 64) {
2891 REDUCE_FLS(nsec
, frequency
);
2895 divisor
= nsec
* frequency
;
2901 return div64_u64(dividend
, divisor
);
2904 static DEFINE_PER_CPU(int, perf_throttled_count
);
2905 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2907 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2909 struct hw_perf_event
*hwc
= &event
->hw
;
2910 s64 period
, sample_period
;
2913 period
= perf_calculate_period(event
, nsec
, count
);
2915 delta
= (s64
)(period
- hwc
->sample_period
);
2916 delta
= (delta
+ 7) / 8; /* low pass filter */
2918 sample_period
= hwc
->sample_period
+ delta
;
2923 hwc
->sample_period
= sample_period
;
2925 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2927 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2929 local64_set(&hwc
->period_left
, 0);
2932 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2937 * combine freq adjustment with unthrottling to avoid two passes over the
2938 * events. At the same time, make sure, having freq events does not change
2939 * the rate of unthrottling as that would introduce bias.
2941 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2944 struct perf_event
*event
;
2945 struct hw_perf_event
*hwc
;
2946 u64 now
, period
= TICK_NSEC
;
2950 * only need to iterate over all events iff:
2951 * - context have events in frequency mode (needs freq adjust)
2952 * - there are events to unthrottle on this cpu
2954 if (!(ctx
->nr_freq
|| needs_unthr
))
2957 raw_spin_lock(&ctx
->lock
);
2958 perf_pmu_disable(ctx
->pmu
);
2960 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2961 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2964 if (!event_filter_match(event
))
2967 perf_pmu_disable(event
->pmu
);
2971 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
2972 hwc
->interrupts
= 0;
2973 perf_log_throttle(event
, 1);
2974 event
->pmu
->start(event
, 0);
2977 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2981 * stop the event and update event->count
2983 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2985 now
= local64_read(&event
->count
);
2986 delta
= now
- hwc
->freq_count_stamp
;
2987 hwc
->freq_count_stamp
= now
;
2991 * reload only if value has changed
2992 * we have stopped the event so tell that
2993 * to perf_adjust_period() to avoid stopping it
2997 perf_adjust_period(event
, period
, delta
, false);
2999 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3001 perf_pmu_enable(event
->pmu
);
3004 perf_pmu_enable(ctx
->pmu
);
3005 raw_spin_unlock(&ctx
->lock
);
3009 * Round-robin a context's events:
3011 static void rotate_ctx(struct perf_event_context
*ctx
)
3014 * Rotate the first entry last of non-pinned groups. Rotation might be
3015 * disabled by the inheritance code.
3017 if (!ctx
->rotate_disable
)
3018 list_rotate_left(&ctx
->flexible_groups
);
3021 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3023 struct perf_event_context
*ctx
= NULL
;
3026 if (cpuctx
->ctx
.nr_events
) {
3027 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3031 ctx
= cpuctx
->task_ctx
;
3032 if (ctx
&& ctx
->nr_events
) {
3033 if (ctx
->nr_events
!= ctx
->nr_active
)
3040 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3041 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3043 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3045 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3047 rotate_ctx(&cpuctx
->ctx
);
3051 perf_event_sched_in(cpuctx
, ctx
, current
);
3053 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3054 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3060 #ifdef CONFIG_NO_HZ_FULL
3061 bool perf_event_can_stop_tick(void)
3063 if (atomic_read(&nr_freq_events
) ||
3064 __this_cpu_read(perf_throttled_count
))
3071 void perf_event_task_tick(void)
3073 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3074 struct perf_event_context
*ctx
, *tmp
;
3077 WARN_ON(!irqs_disabled());
3079 __this_cpu_inc(perf_throttled_seq
);
3080 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3082 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3083 perf_adjust_freq_unthr_context(ctx
, throttled
);
3086 static int event_enable_on_exec(struct perf_event
*event
,
3087 struct perf_event_context
*ctx
)
3089 if (!event
->attr
.enable_on_exec
)
3092 event
->attr
.enable_on_exec
= 0;
3093 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3096 __perf_event_mark_enabled(event
);
3102 * Enable all of a task's events that have been marked enable-on-exec.
3103 * This expects task == current.
3105 static void perf_event_enable_on_exec(int ctxn
)
3107 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3108 struct perf_event
*event
;
3109 unsigned long flags
;
3113 local_irq_save(flags
);
3114 ctx
= current
->perf_event_ctxp
[ctxn
];
3115 if (!ctx
|| !ctx
->nr_events
)
3119 * We must ctxsw out cgroup events to avoid conflict
3120 * when invoking perf_task_event_sched_in() later on
3121 * in this function. Otherwise we end up trying to
3122 * ctxswin cgroup events which are already scheduled
3125 perf_cgroup_sched_out(current
, NULL
);
3127 raw_spin_lock(&ctx
->lock
);
3128 task_ctx_sched_out(ctx
);
3130 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3131 ret
= event_enable_on_exec(event
, ctx
);
3137 * Unclone this context if we enabled any event.
3140 clone_ctx
= unclone_ctx(ctx
);
3142 raw_spin_unlock(&ctx
->lock
);
3145 * Also calls ctxswin for cgroup events, if any:
3147 perf_event_context_sched_in(ctx
, ctx
->task
);
3149 local_irq_restore(flags
);
3155 void perf_event_exec(void)
3160 for_each_task_context_nr(ctxn
)
3161 perf_event_enable_on_exec(ctxn
);
3165 struct perf_read_data
{
3166 struct perf_event
*event
;
3172 * Cross CPU call to read the hardware event
3174 static void __perf_event_read(void *info
)
3176 struct perf_read_data
*data
= info
;
3177 struct perf_event
*sub
, *event
= data
->event
;
3178 struct perf_event_context
*ctx
= event
->ctx
;
3179 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3180 struct pmu
*pmu
= event
->pmu
;
3183 * If this is a task context, we need to check whether it is
3184 * the current task context of this cpu. If not it has been
3185 * scheduled out before the smp call arrived. In that case
3186 * event->count would have been updated to a recent sample
3187 * when the event was scheduled out.
3189 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3192 raw_spin_lock(&ctx
->lock
);
3193 if (ctx
->is_active
) {
3194 update_context_time(ctx
);
3195 update_cgrp_time_from_event(event
);
3198 update_event_times(event
);
3199 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3208 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3212 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3213 update_event_times(sub
);
3214 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3216 * Use sibling's PMU rather than @event's since
3217 * sibling could be on different (eg: software) PMU.
3219 sub
->pmu
->read(sub
);
3223 data
->ret
= pmu
->commit_txn(pmu
);
3226 raw_spin_unlock(&ctx
->lock
);
3229 static inline u64
perf_event_count(struct perf_event
*event
)
3231 if (event
->pmu
->count
)
3232 return event
->pmu
->count(event
);
3234 return __perf_event_count(event
);
3238 * NMI-safe method to read a local event, that is an event that
3240 * - either for the current task, or for this CPU
3241 * - does not have inherit set, for inherited task events
3242 * will not be local and we cannot read them atomically
3243 * - must not have a pmu::count method
3245 u64
perf_event_read_local(struct perf_event
*event
)
3247 unsigned long flags
;
3251 * Disabling interrupts avoids all counter scheduling (context
3252 * switches, timer based rotation and IPIs).
3254 local_irq_save(flags
);
3256 /* If this is a per-task event, it must be for current */
3257 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3258 event
->hw
.target
!= current
);
3260 /* If this is a per-CPU event, it must be for this CPU */
3261 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3262 event
->cpu
!= smp_processor_id());
3265 * It must not be an event with inherit set, we cannot read
3266 * all child counters from atomic context.
3268 WARN_ON_ONCE(event
->attr
.inherit
);
3271 * It must not have a pmu::count method, those are not
3274 WARN_ON_ONCE(event
->pmu
->count
);
3277 * If the event is currently on this CPU, its either a per-task event,
3278 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3281 if (event
->oncpu
== smp_processor_id())
3282 event
->pmu
->read(event
);
3284 val
= local64_read(&event
->count
);
3285 local_irq_restore(flags
);
3290 static int perf_event_read(struct perf_event
*event
, bool group
)
3295 * If event is enabled and currently active on a CPU, update the
3296 * value in the event structure:
3298 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3299 struct perf_read_data data
= {
3304 smp_call_function_single(event
->oncpu
,
3305 __perf_event_read
, &data
, 1);
3307 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3308 struct perf_event_context
*ctx
= event
->ctx
;
3309 unsigned long flags
;
3311 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3313 * may read while context is not active
3314 * (e.g., thread is blocked), in that case
3315 * we cannot update context time
3317 if (ctx
->is_active
) {
3318 update_context_time(ctx
);
3319 update_cgrp_time_from_event(event
);
3322 update_group_times(event
);
3324 update_event_times(event
);
3325 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3332 * Initialize the perf_event context in a task_struct:
3334 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3336 raw_spin_lock_init(&ctx
->lock
);
3337 mutex_init(&ctx
->mutex
);
3338 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3339 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3340 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3341 INIT_LIST_HEAD(&ctx
->event_list
);
3342 atomic_set(&ctx
->refcount
, 1);
3343 INIT_DELAYED_WORK(&ctx
->orphans_remove
, orphans_remove_work
);
3346 static struct perf_event_context
*
3347 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3349 struct perf_event_context
*ctx
;
3351 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3355 __perf_event_init_context(ctx
);
3358 get_task_struct(task
);
3365 static struct task_struct
*
3366 find_lively_task_by_vpid(pid_t vpid
)
3368 struct task_struct
*task
;
3375 task
= find_task_by_vpid(vpid
);
3377 get_task_struct(task
);
3381 return ERR_PTR(-ESRCH
);
3383 /* Reuse ptrace permission checks for now. */
3385 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3390 put_task_struct(task
);
3391 return ERR_PTR(err
);
3396 * Returns a matching context with refcount and pincount.
3398 static struct perf_event_context
*
3399 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3400 struct perf_event
*event
)
3402 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3403 struct perf_cpu_context
*cpuctx
;
3404 void *task_ctx_data
= NULL
;
3405 unsigned long flags
;
3407 int cpu
= event
->cpu
;
3410 /* Must be root to operate on a CPU event: */
3411 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3412 return ERR_PTR(-EACCES
);
3415 * We could be clever and allow to attach a event to an
3416 * offline CPU and activate it when the CPU comes up, but
3419 if (!cpu_online(cpu
))
3420 return ERR_PTR(-ENODEV
);
3422 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3431 ctxn
= pmu
->task_ctx_nr
;
3435 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3436 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3437 if (!task_ctx_data
) {
3444 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3446 clone_ctx
= unclone_ctx(ctx
);
3449 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3450 ctx
->task_ctx_data
= task_ctx_data
;
3451 task_ctx_data
= NULL
;
3453 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3458 ctx
= alloc_perf_context(pmu
, task
);
3463 if (task_ctx_data
) {
3464 ctx
->task_ctx_data
= task_ctx_data
;
3465 task_ctx_data
= NULL
;
3469 mutex_lock(&task
->perf_event_mutex
);
3471 * If it has already passed perf_event_exit_task().
3472 * we must see PF_EXITING, it takes this mutex too.
3474 if (task
->flags
& PF_EXITING
)
3476 else if (task
->perf_event_ctxp
[ctxn
])
3481 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3483 mutex_unlock(&task
->perf_event_mutex
);
3485 if (unlikely(err
)) {
3494 kfree(task_ctx_data
);
3498 kfree(task_ctx_data
);
3499 return ERR_PTR(err
);
3502 static void perf_event_free_filter(struct perf_event
*event
);
3503 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3505 static void free_event_rcu(struct rcu_head
*head
)
3507 struct perf_event
*event
;
3509 event
= container_of(head
, struct perf_event
, rcu_head
);
3511 put_pid_ns(event
->ns
);
3512 perf_event_free_filter(event
);
3516 static void ring_buffer_attach(struct perf_event
*event
,
3517 struct ring_buffer
*rb
);
3519 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3524 if (is_cgroup_event(event
))
3525 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3528 static void unaccount_event(struct perf_event
*event
)
3533 if (event
->attach_state
& PERF_ATTACH_TASK
)
3534 static_key_slow_dec_deferred(&perf_sched_events
);
3535 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3536 atomic_dec(&nr_mmap_events
);
3537 if (event
->attr
.comm
)
3538 atomic_dec(&nr_comm_events
);
3539 if (event
->attr
.task
)
3540 atomic_dec(&nr_task_events
);
3541 if (event
->attr
.freq
)
3542 atomic_dec(&nr_freq_events
);
3543 if (event
->attr
.context_switch
) {
3544 static_key_slow_dec_deferred(&perf_sched_events
);
3545 atomic_dec(&nr_switch_events
);
3547 if (is_cgroup_event(event
))
3548 static_key_slow_dec_deferred(&perf_sched_events
);
3549 if (has_branch_stack(event
))
3550 static_key_slow_dec_deferred(&perf_sched_events
);
3552 unaccount_event_cpu(event
, event
->cpu
);
3556 * The following implement mutual exclusion of events on "exclusive" pmus
3557 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3558 * at a time, so we disallow creating events that might conflict, namely:
3560 * 1) cpu-wide events in the presence of per-task events,
3561 * 2) per-task events in the presence of cpu-wide events,
3562 * 3) two matching events on the same context.
3564 * The former two cases are handled in the allocation path (perf_event_alloc(),
3565 * __free_event()), the latter -- before the first perf_install_in_context().
3567 static int exclusive_event_init(struct perf_event
*event
)
3569 struct pmu
*pmu
= event
->pmu
;
3571 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3575 * Prevent co-existence of per-task and cpu-wide events on the
3576 * same exclusive pmu.
3578 * Negative pmu::exclusive_cnt means there are cpu-wide
3579 * events on this "exclusive" pmu, positive means there are
3582 * Since this is called in perf_event_alloc() path, event::ctx
3583 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3584 * to mean "per-task event", because unlike other attach states it
3585 * never gets cleared.
3587 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3588 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3591 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3598 static void exclusive_event_destroy(struct perf_event
*event
)
3600 struct pmu
*pmu
= event
->pmu
;
3602 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3605 /* see comment in exclusive_event_init() */
3606 if (event
->attach_state
& PERF_ATTACH_TASK
)
3607 atomic_dec(&pmu
->exclusive_cnt
);
3609 atomic_inc(&pmu
->exclusive_cnt
);
3612 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3614 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3615 (e1
->cpu
== e2
->cpu
||
3622 /* Called under the same ctx::mutex as perf_install_in_context() */
3623 static bool exclusive_event_installable(struct perf_event
*event
,
3624 struct perf_event_context
*ctx
)
3626 struct perf_event
*iter_event
;
3627 struct pmu
*pmu
= event
->pmu
;
3629 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3632 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3633 if (exclusive_event_match(iter_event
, event
))
3640 static void __free_event(struct perf_event
*event
)
3642 if (!event
->parent
) {
3643 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3644 put_callchain_buffers();
3647 perf_event_free_bpf_prog(event
);
3650 event
->destroy(event
);
3653 put_ctx(event
->ctx
);
3656 exclusive_event_destroy(event
);
3657 module_put(event
->pmu
->module
);
3660 call_rcu(&event
->rcu_head
, free_event_rcu
);
3663 static void _free_event(struct perf_event
*event
)
3665 irq_work_sync(&event
->pending
);
3667 unaccount_event(event
);
3671 * Can happen when we close an event with re-directed output.
3673 * Since we have a 0 refcount, perf_mmap_close() will skip
3674 * over us; possibly making our ring_buffer_put() the last.
3676 mutex_lock(&event
->mmap_mutex
);
3677 ring_buffer_attach(event
, NULL
);
3678 mutex_unlock(&event
->mmap_mutex
);
3681 if (is_cgroup_event(event
))
3682 perf_detach_cgroup(event
);
3684 __free_event(event
);
3688 * Used to free events which have a known refcount of 1, such as in error paths
3689 * where the event isn't exposed yet and inherited events.
3691 static void free_event(struct perf_event
*event
)
3693 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3694 "unexpected event refcount: %ld; ptr=%p\n",
3695 atomic_long_read(&event
->refcount
), event
)) {
3696 /* leak to avoid use-after-free */
3704 * Remove user event from the owner task.
3706 static void perf_remove_from_owner(struct perf_event
*event
)
3708 struct task_struct
*owner
;
3711 owner
= ACCESS_ONCE(event
->owner
);
3713 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3714 * !owner it means the list deletion is complete and we can indeed
3715 * free this event, otherwise we need to serialize on
3716 * owner->perf_event_mutex.
3718 smp_read_barrier_depends();
3721 * Since delayed_put_task_struct() also drops the last
3722 * task reference we can safely take a new reference
3723 * while holding the rcu_read_lock().
3725 get_task_struct(owner
);
3731 * If we're here through perf_event_exit_task() we're already
3732 * holding ctx->mutex which would be an inversion wrt. the
3733 * normal lock order.
3735 * However we can safely take this lock because its the child
3738 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3741 * We have to re-check the event->owner field, if it is cleared
3742 * we raced with perf_event_exit_task(), acquiring the mutex
3743 * ensured they're done, and we can proceed with freeing the
3747 list_del_init(&event
->owner_entry
);
3748 mutex_unlock(&owner
->perf_event_mutex
);
3749 put_task_struct(owner
);
3753 static void put_event(struct perf_event
*event
)
3755 struct perf_event_context
*ctx
;
3757 if (!atomic_long_dec_and_test(&event
->refcount
))
3760 if (!is_kernel_event(event
))
3761 perf_remove_from_owner(event
);
3764 * There are two ways this annotation is useful:
3766 * 1) there is a lock recursion from perf_event_exit_task
3767 * see the comment there.
3769 * 2) there is a lock-inversion with mmap_sem through
3770 * perf_read_group(), which takes faults while
3771 * holding ctx->mutex, however this is called after
3772 * the last filedesc died, so there is no possibility
3773 * to trigger the AB-BA case.
3775 ctx
= perf_event_ctx_lock_nested(event
, SINGLE_DEPTH_NESTING
);
3776 WARN_ON_ONCE(ctx
->parent_ctx
);
3777 perf_remove_from_context(event
, true);
3778 perf_event_ctx_unlock(event
, ctx
);
3783 int perf_event_release_kernel(struct perf_event
*event
)
3788 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3791 * Called when the last reference to the file is gone.
3793 static int perf_release(struct inode
*inode
, struct file
*file
)
3795 put_event(file
->private_data
);
3800 * Remove all orphanes events from the context.
3802 static void orphans_remove_work(struct work_struct
*work
)
3804 struct perf_event_context
*ctx
;
3805 struct perf_event
*event
, *tmp
;
3807 ctx
= container_of(work
, struct perf_event_context
,
3808 orphans_remove
.work
);
3810 mutex_lock(&ctx
->mutex
);
3811 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
) {
3812 struct perf_event
*parent_event
= event
->parent
;
3814 if (!is_orphaned_child(event
))
3817 perf_remove_from_context(event
, true);
3819 mutex_lock(&parent_event
->child_mutex
);
3820 list_del_init(&event
->child_list
);
3821 mutex_unlock(&parent_event
->child_mutex
);
3824 put_event(parent_event
);
3827 raw_spin_lock_irq(&ctx
->lock
);
3828 ctx
->orphans_remove_sched
= false;
3829 raw_spin_unlock_irq(&ctx
->lock
);
3830 mutex_unlock(&ctx
->mutex
);
3835 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3837 struct perf_event
*child
;
3843 mutex_lock(&event
->child_mutex
);
3845 (void)perf_event_read(event
, false);
3846 total
+= perf_event_count(event
);
3848 *enabled
+= event
->total_time_enabled
+
3849 atomic64_read(&event
->child_total_time_enabled
);
3850 *running
+= event
->total_time_running
+
3851 atomic64_read(&event
->child_total_time_running
);
3853 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3854 (void)perf_event_read(child
, false);
3855 total
+= perf_event_count(child
);
3856 *enabled
+= child
->total_time_enabled
;
3857 *running
+= child
->total_time_running
;
3859 mutex_unlock(&event
->child_mutex
);
3863 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3865 static int __perf_read_group_add(struct perf_event
*leader
,
3866 u64 read_format
, u64
*values
)
3868 struct perf_event
*sub
;
3869 int n
= 1; /* skip @nr */
3872 ret
= perf_event_read(leader
, true);
3877 * Since we co-schedule groups, {enabled,running} times of siblings
3878 * will be identical to those of the leader, so we only publish one
3881 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3882 values
[n
++] += leader
->total_time_enabled
+
3883 atomic64_read(&leader
->child_total_time_enabled
);
3886 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3887 values
[n
++] += leader
->total_time_running
+
3888 atomic64_read(&leader
->child_total_time_running
);
3892 * Write {count,id} tuples for every sibling.
3894 values
[n
++] += perf_event_count(leader
);
3895 if (read_format
& PERF_FORMAT_ID
)
3896 values
[n
++] = primary_event_id(leader
);
3898 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3899 values
[n
++] += perf_event_count(sub
);
3900 if (read_format
& PERF_FORMAT_ID
)
3901 values
[n
++] = primary_event_id(sub
);
3907 static int perf_read_group(struct perf_event
*event
,
3908 u64 read_format
, char __user
*buf
)
3910 struct perf_event
*leader
= event
->group_leader
, *child
;
3911 struct perf_event_context
*ctx
= leader
->ctx
;
3915 lockdep_assert_held(&ctx
->mutex
);
3917 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
3921 values
[0] = 1 + leader
->nr_siblings
;
3924 * By locking the child_mutex of the leader we effectively
3925 * lock the child list of all siblings.. XXX explain how.
3927 mutex_lock(&leader
->child_mutex
);
3929 ret
= __perf_read_group_add(leader
, read_format
, values
);
3933 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
3934 ret
= __perf_read_group_add(child
, read_format
, values
);
3939 mutex_unlock(&leader
->child_mutex
);
3941 ret
= event
->read_size
;
3942 if (copy_to_user(buf
, values
, event
->read_size
))
3947 mutex_unlock(&leader
->child_mutex
);
3953 static int perf_read_one(struct perf_event
*event
,
3954 u64 read_format
, char __user
*buf
)
3956 u64 enabled
, running
;
3960 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3961 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3962 values
[n
++] = enabled
;
3963 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3964 values
[n
++] = running
;
3965 if (read_format
& PERF_FORMAT_ID
)
3966 values
[n
++] = primary_event_id(event
);
3968 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3971 return n
* sizeof(u64
);
3974 static bool is_event_hup(struct perf_event
*event
)
3978 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
3981 mutex_lock(&event
->child_mutex
);
3982 no_children
= list_empty(&event
->child_list
);
3983 mutex_unlock(&event
->child_mutex
);
3988 * Read the performance event - simple non blocking version for now
3991 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
3993 u64 read_format
= event
->attr
.read_format
;
3997 * Return end-of-file for a read on a event that is in
3998 * error state (i.e. because it was pinned but it couldn't be
3999 * scheduled on to the CPU at some point).
4001 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4004 if (count
< event
->read_size
)
4007 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4008 if (read_format
& PERF_FORMAT_GROUP
)
4009 ret
= perf_read_group(event
, read_format
, buf
);
4011 ret
= perf_read_one(event
, read_format
, buf
);
4017 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4019 struct perf_event
*event
= file
->private_data
;
4020 struct perf_event_context
*ctx
;
4023 ctx
= perf_event_ctx_lock(event
);
4024 ret
= __perf_read(event
, buf
, count
);
4025 perf_event_ctx_unlock(event
, ctx
);
4030 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4032 struct perf_event
*event
= file
->private_data
;
4033 struct ring_buffer
*rb
;
4034 unsigned int events
= POLLHUP
;
4036 poll_wait(file
, &event
->waitq
, wait
);
4038 if (is_event_hup(event
))
4042 * Pin the event->rb by taking event->mmap_mutex; otherwise
4043 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4045 mutex_lock(&event
->mmap_mutex
);
4048 events
= atomic_xchg(&rb
->poll
, 0);
4049 mutex_unlock(&event
->mmap_mutex
);
4053 static void _perf_event_reset(struct perf_event
*event
)
4055 (void)perf_event_read(event
, false);
4056 local64_set(&event
->count
, 0);
4057 perf_event_update_userpage(event
);
4061 * Holding the top-level event's child_mutex means that any
4062 * descendant process that has inherited this event will block
4063 * in sync_child_event if it goes to exit, thus satisfying the
4064 * task existence requirements of perf_event_enable/disable.
4066 static void perf_event_for_each_child(struct perf_event
*event
,
4067 void (*func
)(struct perf_event
*))
4069 struct perf_event
*child
;
4071 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4073 mutex_lock(&event
->child_mutex
);
4075 list_for_each_entry(child
, &event
->child_list
, child_list
)
4077 mutex_unlock(&event
->child_mutex
);
4080 static void perf_event_for_each(struct perf_event
*event
,
4081 void (*func
)(struct perf_event
*))
4083 struct perf_event_context
*ctx
= event
->ctx
;
4084 struct perf_event
*sibling
;
4086 lockdep_assert_held(&ctx
->mutex
);
4088 event
= event
->group_leader
;
4090 perf_event_for_each_child(event
, func
);
4091 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4092 perf_event_for_each_child(sibling
, func
);
4095 struct period_event
{
4096 struct perf_event
*event
;
4100 static void ___perf_event_period(void *info
)
4102 struct period_event
*pe
= info
;
4103 struct perf_event
*event
= pe
->event
;
4104 u64 value
= pe
->value
;
4106 if (event
->attr
.freq
) {
4107 event
->attr
.sample_freq
= value
;
4109 event
->attr
.sample_period
= value
;
4110 event
->hw
.sample_period
= value
;
4113 local64_set(&event
->hw
.period_left
, 0);
4116 static int __perf_event_period(void *info
)
4118 struct period_event
*pe
= info
;
4119 struct perf_event
*event
= pe
->event
;
4120 struct perf_event_context
*ctx
= event
->ctx
;
4121 u64 value
= pe
->value
;
4124 raw_spin_lock(&ctx
->lock
);
4125 if (event
->attr
.freq
) {
4126 event
->attr
.sample_freq
= value
;
4128 event
->attr
.sample_period
= value
;
4129 event
->hw
.sample_period
= value
;
4132 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4134 perf_pmu_disable(ctx
->pmu
);
4135 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4138 local64_set(&event
->hw
.period_left
, 0);
4141 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4142 perf_pmu_enable(ctx
->pmu
);
4144 raw_spin_unlock(&ctx
->lock
);
4149 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4151 struct period_event pe
= { .event
= event
, };
4154 if (!is_sampling_event(event
))
4157 if (copy_from_user(&value
, arg
, sizeof(value
)))
4163 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4168 event_function_call(event
, __perf_event_period
,
4169 ___perf_event_period
, &pe
);
4174 static const struct file_operations perf_fops
;
4176 static inline int perf_fget_light(int fd
, struct fd
*p
)
4178 struct fd f
= fdget(fd
);
4182 if (f
.file
->f_op
!= &perf_fops
) {
4190 static int perf_event_set_output(struct perf_event
*event
,
4191 struct perf_event
*output_event
);
4192 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4193 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4195 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4197 void (*func
)(struct perf_event
*);
4201 case PERF_EVENT_IOC_ENABLE
:
4202 func
= _perf_event_enable
;
4204 case PERF_EVENT_IOC_DISABLE
:
4205 func
= _perf_event_disable
;
4207 case PERF_EVENT_IOC_RESET
:
4208 func
= _perf_event_reset
;
4211 case PERF_EVENT_IOC_REFRESH
:
4212 return _perf_event_refresh(event
, arg
);
4214 case PERF_EVENT_IOC_PERIOD
:
4215 return perf_event_period(event
, (u64 __user
*)arg
);
4217 case PERF_EVENT_IOC_ID
:
4219 u64 id
= primary_event_id(event
);
4221 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4226 case PERF_EVENT_IOC_SET_OUTPUT
:
4230 struct perf_event
*output_event
;
4232 ret
= perf_fget_light(arg
, &output
);
4235 output_event
= output
.file
->private_data
;
4236 ret
= perf_event_set_output(event
, output_event
);
4239 ret
= perf_event_set_output(event
, NULL
);
4244 case PERF_EVENT_IOC_SET_FILTER
:
4245 return perf_event_set_filter(event
, (void __user
*)arg
);
4247 case PERF_EVENT_IOC_SET_BPF
:
4248 return perf_event_set_bpf_prog(event
, arg
);
4254 if (flags
& PERF_IOC_FLAG_GROUP
)
4255 perf_event_for_each(event
, func
);
4257 perf_event_for_each_child(event
, func
);
4262 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4264 struct perf_event
*event
= file
->private_data
;
4265 struct perf_event_context
*ctx
;
4268 ctx
= perf_event_ctx_lock(event
);
4269 ret
= _perf_ioctl(event
, cmd
, arg
);
4270 perf_event_ctx_unlock(event
, ctx
);
4275 #ifdef CONFIG_COMPAT
4276 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4279 switch (_IOC_NR(cmd
)) {
4280 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4281 case _IOC_NR(PERF_EVENT_IOC_ID
):
4282 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4283 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4284 cmd
&= ~IOCSIZE_MASK
;
4285 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4289 return perf_ioctl(file
, cmd
, arg
);
4292 # define perf_compat_ioctl NULL
4295 int perf_event_task_enable(void)
4297 struct perf_event_context
*ctx
;
4298 struct perf_event
*event
;
4300 mutex_lock(¤t
->perf_event_mutex
);
4301 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4302 ctx
= perf_event_ctx_lock(event
);
4303 perf_event_for_each_child(event
, _perf_event_enable
);
4304 perf_event_ctx_unlock(event
, ctx
);
4306 mutex_unlock(¤t
->perf_event_mutex
);
4311 int perf_event_task_disable(void)
4313 struct perf_event_context
*ctx
;
4314 struct perf_event
*event
;
4316 mutex_lock(¤t
->perf_event_mutex
);
4317 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4318 ctx
= perf_event_ctx_lock(event
);
4319 perf_event_for_each_child(event
, _perf_event_disable
);
4320 perf_event_ctx_unlock(event
, ctx
);
4322 mutex_unlock(¤t
->perf_event_mutex
);
4327 static int perf_event_index(struct perf_event
*event
)
4329 if (event
->hw
.state
& PERF_HES_STOPPED
)
4332 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4335 return event
->pmu
->event_idx(event
);
4338 static void calc_timer_values(struct perf_event
*event
,
4345 *now
= perf_clock();
4346 ctx_time
= event
->shadow_ctx_time
+ *now
;
4347 *enabled
= ctx_time
- event
->tstamp_enabled
;
4348 *running
= ctx_time
- event
->tstamp_running
;
4351 static void perf_event_init_userpage(struct perf_event
*event
)
4353 struct perf_event_mmap_page
*userpg
;
4354 struct ring_buffer
*rb
;
4357 rb
= rcu_dereference(event
->rb
);
4361 userpg
= rb
->user_page
;
4363 /* Allow new userspace to detect that bit 0 is deprecated */
4364 userpg
->cap_bit0_is_deprecated
= 1;
4365 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4366 userpg
->data_offset
= PAGE_SIZE
;
4367 userpg
->data_size
= perf_data_size(rb
);
4373 void __weak
arch_perf_update_userpage(
4374 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4379 * Callers need to ensure there can be no nesting of this function, otherwise
4380 * the seqlock logic goes bad. We can not serialize this because the arch
4381 * code calls this from NMI context.
4383 void perf_event_update_userpage(struct perf_event
*event
)
4385 struct perf_event_mmap_page
*userpg
;
4386 struct ring_buffer
*rb
;
4387 u64 enabled
, running
, now
;
4390 rb
= rcu_dereference(event
->rb
);
4395 * compute total_time_enabled, total_time_running
4396 * based on snapshot values taken when the event
4397 * was last scheduled in.
4399 * we cannot simply called update_context_time()
4400 * because of locking issue as we can be called in
4403 calc_timer_values(event
, &now
, &enabled
, &running
);
4405 userpg
= rb
->user_page
;
4407 * Disable preemption so as to not let the corresponding user-space
4408 * spin too long if we get preempted.
4413 userpg
->index
= perf_event_index(event
);
4414 userpg
->offset
= perf_event_count(event
);
4416 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4418 userpg
->time_enabled
= enabled
+
4419 atomic64_read(&event
->child_total_time_enabled
);
4421 userpg
->time_running
= running
+
4422 atomic64_read(&event
->child_total_time_running
);
4424 arch_perf_update_userpage(event
, userpg
, now
);
4433 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4435 struct perf_event
*event
= vma
->vm_file
->private_data
;
4436 struct ring_buffer
*rb
;
4437 int ret
= VM_FAULT_SIGBUS
;
4439 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4440 if (vmf
->pgoff
== 0)
4446 rb
= rcu_dereference(event
->rb
);
4450 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4453 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4457 get_page(vmf
->page
);
4458 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4459 vmf
->page
->index
= vmf
->pgoff
;
4468 static void ring_buffer_attach(struct perf_event
*event
,
4469 struct ring_buffer
*rb
)
4471 struct ring_buffer
*old_rb
= NULL
;
4472 unsigned long flags
;
4476 * Should be impossible, we set this when removing
4477 * event->rb_entry and wait/clear when adding event->rb_entry.
4479 WARN_ON_ONCE(event
->rcu_pending
);
4482 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4483 list_del_rcu(&event
->rb_entry
);
4484 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4486 event
->rcu_batches
= get_state_synchronize_rcu();
4487 event
->rcu_pending
= 1;
4491 if (event
->rcu_pending
) {
4492 cond_synchronize_rcu(event
->rcu_batches
);
4493 event
->rcu_pending
= 0;
4496 spin_lock_irqsave(&rb
->event_lock
, flags
);
4497 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4498 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4501 rcu_assign_pointer(event
->rb
, rb
);
4504 ring_buffer_put(old_rb
);
4506 * Since we detached before setting the new rb, so that we
4507 * could attach the new rb, we could have missed a wakeup.
4510 wake_up_all(&event
->waitq
);
4514 static void ring_buffer_wakeup(struct perf_event
*event
)
4516 struct ring_buffer
*rb
;
4519 rb
= rcu_dereference(event
->rb
);
4521 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4522 wake_up_all(&event
->waitq
);
4527 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4529 struct ring_buffer
*rb
;
4532 rb
= rcu_dereference(event
->rb
);
4534 if (!atomic_inc_not_zero(&rb
->refcount
))
4542 void ring_buffer_put(struct ring_buffer
*rb
)
4544 if (!atomic_dec_and_test(&rb
->refcount
))
4547 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4549 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4552 static void perf_mmap_open(struct vm_area_struct
*vma
)
4554 struct perf_event
*event
= vma
->vm_file
->private_data
;
4556 atomic_inc(&event
->mmap_count
);
4557 atomic_inc(&event
->rb
->mmap_count
);
4560 atomic_inc(&event
->rb
->aux_mmap_count
);
4562 if (event
->pmu
->event_mapped
)
4563 event
->pmu
->event_mapped(event
);
4567 * A buffer can be mmap()ed multiple times; either directly through the same
4568 * event, or through other events by use of perf_event_set_output().
4570 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4571 * the buffer here, where we still have a VM context. This means we need
4572 * to detach all events redirecting to us.
4574 static void perf_mmap_close(struct vm_area_struct
*vma
)
4576 struct perf_event
*event
= vma
->vm_file
->private_data
;
4578 struct ring_buffer
*rb
= ring_buffer_get(event
);
4579 struct user_struct
*mmap_user
= rb
->mmap_user
;
4580 int mmap_locked
= rb
->mmap_locked
;
4581 unsigned long size
= perf_data_size(rb
);
4583 if (event
->pmu
->event_unmapped
)
4584 event
->pmu
->event_unmapped(event
);
4587 * rb->aux_mmap_count will always drop before rb->mmap_count and
4588 * event->mmap_count, so it is ok to use event->mmap_mutex to
4589 * serialize with perf_mmap here.
4591 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4592 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4593 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4594 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4597 mutex_unlock(&event
->mmap_mutex
);
4600 atomic_dec(&rb
->mmap_count
);
4602 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4605 ring_buffer_attach(event
, NULL
);
4606 mutex_unlock(&event
->mmap_mutex
);
4608 /* If there's still other mmap()s of this buffer, we're done. */
4609 if (atomic_read(&rb
->mmap_count
))
4613 * No other mmap()s, detach from all other events that might redirect
4614 * into the now unreachable buffer. Somewhat complicated by the
4615 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4619 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4620 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4622 * This event is en-route to free_event() which will
4623 * detach it and remove it from the list.
4629 mutex_lock(&event
->mmap_mutex
);
4631 * Check we didn't race with perf_event_set_output() which can
4632 * swizzle the rb from under us while we were waiting to
4633 * acquire mmap_mutex.
4635 * If we find a different rb; ignore this event, a next
4636 * iteration will no longer find it on the list. We have to
4637 * still restart the iteration to make sure we're not now
4638 * iterating the wrong list.
4640 if (event
->rb
== rb
)
4641 ring_buffer_attach(event
, NULL
);
4643 mutex_unlock(&event
->mmap_mutex
);
4647 * Restart the iteration; either we're on the wrong list or
4648 * destroyed its integrity by doing a deletion.
4655 * It could be there's still a few 0-ref events on the list; they'll
4656 * get cleaned up by free_event() -- they'll also still have their
4657 * ref on the rb and will free it whenever they are done with it.
4659 * Aside from that, this buffer is 'fully' detached and unmapped,
4660 * undo the VM accounting.
4663 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4664 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4665 free_uid(mmap_user
);
4668 ring_buffer_put(rb
); /* could be last */
4671 static const struct vm_operations_struct perf_mmap_vmops
= {
4672 .open
= perf_mmap_open
,
4673 .close
= perf_mmap_close
, /* non mergable */
4674 .fault
= perf_mmap_fault
,
4675 .page_mkwrite
= perf_mmap_fault
,
4678 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4680 struct perf_event
*event
= file
->private_data
;
4681 unsigned long user_locked
, user_lock_limit
;
4682 struct user_struct
*user
= current_user();
4683 unsigned long locked
, lock_limit
;
4684 struct ring_buffer
*rb
= NULL
;
4685 unsigned long vma_size
;
4686 unsigned long nr_pages
;
4687 long user_extra
= 0, extra
= 0;
4688 int ret
= 0, flags
= 0;
4691 * Don't allow mmap() of inherited per-task counters. This would
4692 * create a performance issue due to all children writing to the
4695 if (event
->cpu
== -1 && event
->attr
.inherit
)
4698 if (!(vma
->vm_flags
& VM_SHARED
))
4701 vma_size
= vma
->vm_end
- vma
->vm_start
;
4703 if (vma
->vm_pgoff
== 0) {
4704 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4707 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4708 * mapped, all subsequent mappings should have the same size
4709 * and offset. Must be above the normal perf buffer.
4711 u64 aux_offset
, aux_size
;
4716 nr_pages
= vma_size
/ PAGE_SIZE
;
4718 mutex_lock(&event
->mmap_mutex
);
4725 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4726 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4728 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4731 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4734 /* already mapped with a different offset */
4735 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4738 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4741 /* already mapped with a different size */
4742 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4745 if (!is_power_of_2(nr_pages
))
4748 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4751 if (rb_has_aux(rb
)) {
4752 atomic_inc(&rb
->aux_mmap_count
);
4757 atomic_set(&rb
->aux_mmap_count
, 1);
4758 user_extra
= nr_pages
;
4764 * If we have rb pages ensure they're a power-of-two number, so we
4765 * can do bitmasks instead of modulo.
4767 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4770 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4773 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4775 mutex_lock(&event
->mmap_mutex
);
4777 if (event
->rb
->nr_pages
!= nr_pages
) {
4782 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4784 * Raced against perf_mmap_close() through
4785 * perf_event_set_output(). Try again, hope for better
4788 mutex_unlock(&event
->mmap_mutex
);
4795 user_extra
= nr_pages
+ 1;
4798 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4801 * Increase the limit linearly with more CPUs:
4803 user_lock_limit
*= num_online_cpus();
4805 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4807 if (user_locked
> user_lock_limit
)
4808 extra
= user_locked
- user_lock_limit
;
4810 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4811 lock_limit
>>= PAGE_SHIFT
;
4812 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4814 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4815 !capable(CAP_IPC_LOCK
)) {
4820 WARN_ON(!rb
&& event
->rb
);
4822 if (vma
->vm_flags
& VM_WRITE
)
4823 flags
|= RING_BUFFER_WRITABLE
;
4826 rb
= rb_alloc(nr_pages
,
4827 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4835 atomic_set(&rb
->mmap_count
, 1);
4836 rb
->mmap_user
= get_current_user();
4837 rb
->mmap_locked
= extra
;
4839 ring_buffer_attach(event
, rb
);
4841 perf_event_init_userpage(event
);
4842 perf_event_update_userpage(event
);
4844 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4845 event
->attr
.aux_watermark
, flags
);
4847 rb
->aux_mmap_locked
= extra
;
4852 atomic_long_add(user_extra
, &user
->locked_vm
);
4853 vma
->vm_mm
->pinned_vm
+= extra
;
4855 atomic_inc(&event
->mmap_count
);
4857 atomic_dec(&rb
->mmap_count
);
4860 mutex_unlock(&event
->mmap_mutex
);
4863 * Since pinned accounting is per vm we cannot allow fork() to copy our
4866 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4867 vma
->vm_ops
= &perf_mmap_vmops
;
4869 if (event
->pmu
->event_mapped
)
4870 event
->pmu
->event_mapped(event
);
4875 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4877 struct inode
*inode
= file_inode(filp
);
4878 struct perf_event
*event
= filp
->private_data
;
4881 mutex_lock(&inode
->i_mutex
);
4882 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4883 mutex_unlock(&inode
->i_mutex
);
4891 static const struct file_operations perf_fops
= {
4892 .llseek
= no_llseek
,
4893 .release
= perf_release
,
4896 .unlocked_ioctl
= perf_ioctl
,
4897 .compat_ioctl
= perf_compat_ioctl
,
4899 .fasync
= perf_fasync
,
4905 * If there's data, ensure we set the poll() state and publish everything
4906 * to user-space before waking everybody up.
4909 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
4911 /* only the parent has fasync state */
4913 event
= event
->parent
;
4914 return &event
->fasync
;
4917 void perf_event_wakeup(struct perf_event
*event
)
4919 ring_buffer_wakeup(event
);
4921 if (event
->pending_kill
) {
4922 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
4923 event
->pending_kill
= 0;
4927 static void perf_pending_event(struct irq_work
*entry
)
4929 struct perf_event
*event
= container_of(entry
,
4930 struct perf_event
, pending
);
4933 rctx
= perf_swevent_get_recursion_context();
4935 * If we 'fail' here, that's OK, it means recursion is already disabled
4936 * and we won't recurse 'further'.
4939 if (event
->pending_disable
) {
4940 event
->pending_disable
= 0;
4941 __perf_event_disable(event
);
4944 if (event
->pending_wakeup
) {
4945 event
->pending_wakeup
= 0;
4946 perf_event_wakeup(event
);
4950 perf_swevent_put_recursion_context(rctx
);
4954 * We assume there is only KVM supporting the callbacks.
4955 * Later on, we might change it to a list if there is
4956 * another virtualization implementation supporting the callbacks.
4958 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4960 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4962 perf_guest_cbs
= cbs
;
4965 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4967 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4969 perf_guest_cbs
= NULL
;
4972 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4975 perf_output_sample_regs(struct perf_output_handle
*handle
,
4976 struct pt_regs
*regs
, u64 mask
)
4980 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4981 sizeof(mask
) * BITS_PER_BYTE
) {
4984 val
= perf_reg_value(regs
, bit
);
4985 perf_output_put(handle
, val
);
4989 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
4990 struct pt_regs
*regs
,
4991 struct pt_regs
*regs_user_copy
)
4993 if (user_mode(regs
)) {
4994 regs_user
->abi
= perf_reg_abi(current
);
4995 regs_user
->regs
= regs
;
4996 } else if (current
->mm
) {
4997 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
4999 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5000 regs_user
->regs
= NULL
;
5004 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5005 struct pt_regs
*regs
)
5007 regs_intr
->regs
= regs
;
5008 regs_intr
->abi
= perf_reg_abi(current
);
5013 * Get remaining task size from user stack pointer.
5015 * It'd be better to take stack vma map and limit this more
5016 * precisly, but there's no way to get it safely under interrupt,
5017 * so using TASK_SIZE as limit.
5019 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5021 unsigned long addr
= perf_user_stack_pointer(regs
);
5023 if (!addr
|| addr
>= TASK_SIZE
)
5026 return TASK_SIZE
- addr
;
5030 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5031 struct pt_regs
*regs
)
5035 /* No regs, no stack pointer, no dump. */
5040 * Check if we fit in with the requested stack size into the:
5042 * If we don't, we limit the size to the TASK_SIZE.
5044 * - remaining sample size
5045 * If we don't, we customize the stack size to
5046 * fit in to the remaining sample size.
5049 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5050 stack_size
= min(stack_size
, (u16
) task_size
);
5052 /* Current header size plus static size and dynamic size. */
5053 header_size
+= 2 * sizeof(u64
);
5055 /* Do we fit in with the current stack dump size? */
5056 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5058 * If we overflow the maximum size for the sample,
5059 * we customize the stack dump size to fit in.
5061 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5062 stack_size
= round_up(stack_size
, sizeof(u64
));
5069 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5070 struct pt_regs
*regs
)
5072 /* Case of a kernel thread, nothing to dump */
5075 perf_output_put(handle
, size
);
5084 * - the size requested by user or the best one we can fit
5085 * in to the sample max size
5087 * - user stack dump data
5089 * - the actual dumped size
5093 perf_output_put(handle
, dump_size
);
5096 sp
= perf_user_stack_pointer(regs
);
5097 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5098 dyn_size
= dump_size
- rem
;
5100 perf_output_skip(handle
, rem
);
5103 perf_output_put(handle
, dyn_size
);
5107 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5108 struct perf_sample_data
*data
,
5109 struct perf_event
*event
)
5111 u64 sample_type
= event
->attr
.sample_type
;
5113 data
->type
= sample_type
;
5114 header
->size
+= event
->id_header_size
;
5116 if (sample_type
& PERF_SAMPLE_TID
) {
5117 /* namespace issues */
5118 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5119 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5122 if (sample_type
& PERF_SAMPLE_TIME
)
5123 data
->time
= perf_event_clock(event
);
5125 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5126 data
->id
= primary_event_id(event
);
5128 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5129 data
->stream_id
= event
->id
;
5131 if (sample_type
& PERF_SAMPLE_CPU
) {
5132 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5133 data
->cpu_entry
.reserved
= 0;
5137 void perf_event_header__init_id(struct perf_event_header
*header
,
5138 struct perf_sample_data
*data
,
5139 struct perf_event
*event
)
5141 if (event
->attr
.sample_id_all
)
5142 __perf_event_header__init_id(header
, data
, event
);
5145 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5146 struct perf_sample_data
*data
)
5148 u64 sample_type
= data
->type
;
5150 if (sample_type
& PERF_SAMPLE_TID
)
5151 perf_output_put(handle
, data
->tid_entry
);
5153 if (sample_type
& PERF_SAMPLE_TIME
)
5154 perf_output_put(handle
, data
->time
);
5156 if (sample_type
& PERF_SAMPLE_ID
)
5157 perf_output_put(handle
, data
->id
);
5159 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5160 perf_output_put(handle
, data
->stream_id
);
5162 if (sample_type
& PERF_SAMPLE_CPU
)
5163 perf_output_put(handle
, data
->cpu_entry
);
5165 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5166 perf_output_put(handle
, data
->id
);
5169 void perf_event__output_id_sample(struct perf_event
*event
,
5170 struct perf_output_handle
*handle
,
5171 struct perf_sample_data
*sample
)
5173 if (event
->attr
.sample_id_all
)
5174 __perf_event__output_id_sample(handle
, sample
);
5177 static void perf_output_read_one(struct perf_output_handle
*handle
,
5178 struct perf_event
*event
,
5179 u64 enabled
, u64 running
)
5181 u64 read_format
= event
->attr
.read_format
;
5185 values
[n
++] = perf_event_count(event
);
5186 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5187 values
[n
++] = enabled
+
5188 atomic64_read(&event
->child_total_time_enabled
);
5190 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5191 values
[n
++] = running
+
5192 atomic64_read(&event
->child_total_time_running
);
5194 if (read_format
& PERF_FORMAT_ID
)
5195 values
[n
++] = primary_event_id(event
);
5197 __output_copy(handle
, values
, n
* sizeof(u64
));
5201 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5203 static void perf_output_read_group(struct perf_output_handle
*handle
,
5204 struct perf_event
*event
,
5205 u64 enabled
, u64 running
)
5207 struct perf_event
*leader
= event
->group_leader
, *sub
;
5208 u64 read_format
= event
->attr
.read_format
;
5212 values
[n
++] = 1 + leader
->nr_siblings
;
5214 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5215 values
[n
++] = enabled
;
5217 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5218 values
[n
++] = running
;
5220 if (leader
!= event
)
5221 leader
->pmu
->read(leader
);
5223 values
[n
++] = perf_event_count(leader
);
5224 if (read_format
& PERF_FORMAT_ID
)
5225 values
[n
++] = primary_event_id(leader
);
5227 __output_copy(handle
, values
, n
* sizeof(u64
));
5229 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5232 if ((sub
!= event
) &&
5233 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5234 sub
->pmu
->read(sub
);
5236 values
[n
++] = perf_event_count(sub
);
5237 if (read_format
& PERF_FORMAT_ID
)
5238 values
[n
++] = primary_event_id(sub
);
5240 __output_copy(handle
, values
, n
* sizeof(u64
));
5244 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5245 PERF_FORMAT_TOTAL_TIME_RUNNING)
5247 static void perf_output_read(struct perf_output_handle
*handle
,
5248 struct perf_event
*event
)
5250 u64 enabled
= 0, running
= 0, now
;
5251 u64 read_format
= event
->attr
.read_format
;
5254 * compute total_time_enabled, total_time_running
5255 * based on snapshot values taken when the event
5256 * was last scheduled in.
5258 * we cannot simply called update_context_time()
5259 * because of locking issue as we are called in
5262 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5263 calc_timer_values(event
, &now
, &enabled
, &running
);
5265 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5266 perf_output_read_group(handle
, event
, enabled
, running
);
5268 perf_output_read_one(handle
, event
, enabled
, running
);
5271 void perf_output_sample(struct perf_output_handle
*handle
,
5272 struct perf_event_header
*header
,
5273 struct perf_sample_data
*data
,
5274 struct perf_event
*event
)
5276 u64 sample_type
= data
->type
;
5278 perf_output_put(handle
, *header
);
5280 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5281 perf_output_put(handle
, data
->id
);
5283 if (sample_type
& PERF_SAMPLE_IP
)
5284 perf_output_put(handle
, data
->ip
);
5286 if (sample_type
& PERF_SAMPLE_TID
)
5287 perf_output_put(handle
, data
->tid_entry
);
5289 if (sample_type
& PERF_SAMPLE_TIME
)
5290 perf_output_put(handle
, data
->time
);
5292 if (sample_type
& PERF_SAMPLE_ADDR
)
5293 perf_output_put(handle
, data
->addr
);
5295 if (sample_type
& PERF_SAMPLE_ID
)
5296 perf_output_put(handle
, data
->id
);
5298 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5299 perf_output_put(handle
, data
->stream_id
);
5301 if (sample_type
& PERF_SAMPLE_CPU
)
5302 perf_output_put(handle
, data
->cpu_entry
);
5304 if (sample_type
& PERF_SAMPLE_PERIOD
)
5305 perf_output_put(handle
, data
->period
);
5307 if (sample_type
& PERF_SAMPLE_READ
)
5308 perf_output_read(handle
, event
);
5310 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5311 if (data
->callchain
) {
5314 if (data
->callchain
)
5315 size
+= data
->callchain
->nr
;
5317 size
*= sizeof(u64
);
5319 __output_copy(handle
, data
->callchain
, size
);
5322 perf_output_put(handle
, nr
);
5326 if (sample_type
& PERF_SAMPLE_RAW
) {
5328 u32 raw_size
= data
->raw
->size
;
5329 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5330 sizeof(u64
)) - sizeof(u32
);
5333 perf_output_put(handle
, real_size
);
5334 __output_copy(handle
, data
->raw
->data
, raw_size
);
5335 if (real_size
- raw_size
)
5336 __output_copy(handle
, &zero
, real_size
- raw_size
);
5342 .size
= sizeof(u32
),
5345 perf_output_put(handle
, raw
);
5349 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5350 if (data
->br_stack
) {
5353 size
= data
->br_stack
->nr
5354 * sizeof(struct perf_branch_entry
);
5356 perf_output_put(handle
, data
->br_stack
->nr
);
5357 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5360 * we always store at least the value of nr
5363 perf_output_put(handle
, nr
);
5367 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5368 u64 abi
= data
->regs_user
.abi
;
5371 * If there are no regs to dump, notice it through
5372 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5374 perf_output_put(handle
, abi
);
5377 u64 mask
= event
->attr
.sample_regs_user
;
5378 perf_output_sample_regs(handle
,
5379 data
->regs_user
.regs
,
5384 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5385 perf_output_sample_ustack(handle
,
5386 data
->stack_user_size
,
5387 data
->regs_user
.regs
);
5390 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5391 perf_output_put(handle
, data
->weight
);
5393 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5394 perf_output_put(handle
, data
->data_src
.val
);
5396 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5397 perf_output_put(handle
, data
->txn
);
5399 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5400 u64 abi
= data
->regs_intr
.abi
;
5402 * If there are no regs to dump, notice it through
5403 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5405 perf_output_put(handle
, abi
);
5408 u64 mask
= event
->attr
.sample_regs_intr
;
5410 perf_output_sample_regs(handle
,
5411 data
->regs_intr
.regs
,
5416 if (!event
->attr
.watermark
) {
5417 int wakeup_events
= event
->attr
.wakeup_events
;
5419 if (wakeup_events
) {
5420 struct ring_buffer
*rb
= handle
->rb
;
5421 int events
= local_inc_return(&rb
->events
);
5423 if (events
>= wakeup_events
) {
5424 local_sub(wakeup_events
, &rb
->events
);
5425 local_inc(&rb
->wakeup
);
5431 void perf_prepare_sample(struct perf_event_header
*header
,
5432 struct perf_sample_data
*data
,
5433 struct perf_event
*event
,
5434 struct pt_regs
*regs
)
5436 u64 sample_type
= event
->attr
.sample_type
;
5438 header
->type
= PERF_RECORD_SAMPLE
;
5439 header
->size
= sizeof(*header
) + event
->header_size
;
5442 header
->misc
|= perf_misc_flags(regs
);
5444 __perf_event_header__init_id(header
, data
, event
);
5446 if (sample_type
& PERF_SAMPLE_IP
)
5447 data
->ip
= perf_instruction_pointer(regs
);
5449 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5452 data
->callchain
= perf_callchain(event
, regs
);
5454 if (data
->callchain
)
5455 size
+= data
->callchain
->nr
;
5457 header
->size
+= size
* sizeof(u64
);
5460 if (sample_type
& PERF_SAMPLE_RAW
) {
5461 int size
= sizeof(u32
);
5464 size
+= data
->raw
->size
;
5466 size
+= sizeof(u32
);
5468 header
->size
+= round_up(size
, sizeof(u64
));
5471 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5472 int size
= sizeof(u64
); /* nr */
5473 if (data
->br_stack
) {
5474 size
+= data
->br_stack
->nr
5475 * sizeof(struct perf_branch_entry
);
5477 header
->size
+= size
;
5480 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5481 perf_sample_regs_user(&data
->regs_user
, regs
,
5482 &data
->regs_user_copy
);
5484 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5485 /* regs dump ABI info */
5486 int size
= sizeof(u64
);
5488 if (data
->regs_user
.regs
) {
5489 u64 mask
= event
->attr
.sample_regs_user
;
5490 size
+= hweight64(mask
) * sizeof(u64
);
5493 header
->size
+= size
;
5496 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5498 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5499 * processed as the last one or have additional check added
5500 * in case new sample type is added, because we could eat
5501 * up the rest of the sample size.
5503 u16 stack_size
= event
->attr
.sample_stack_user
;
5504 u16 size
= sizeof(u64
);
5506 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5507 data
->regs_user
.regs
);
5510 * If there is something to dump, add space for the dump
5511 * itself and for the field that tells the dynamic size,
5512 * which is how many have been actually dumped.
5515 size
+= sizeof(u64
) + stack_size
;
5517 data
->stack_user_size
= stack_size
;
5518 header
->size
+= size
;
5521 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5522 /* regs dump ABI info */
5523 int size
= sizeof(u64
);
5525 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5527 if (data
->regs_intr
.regs
) {
5528 u64 mask
= event
->attr
.sample_regs_intr
;
5530 size
+= hweight64(mask
) * sizeof(u64
);
5533 header
->size
+= size
;
5537 void perf_event_output(struct perf_event
*event
,
5538 struct perf_sample_data
*data
,
5539 struct pt_regs
*regs
)
5541 struct perf_output_handle handle
;
5542 struct perf_event_header header
;
5544 /* protect the callchain buffers */
5547 perf_prepare_sample(&header
, data
, event
, regs
);
5549 if (perf_output_begin(&handle
, event
, header
.size
))
5552 perf_output_sample(&handle
, &header
, data
, event
);
5554 perf_output_end(&handle
);
5564 struct perf_read_event
{
5565 struct perf_event_header header
;
5572 perf_event_read_event(struct perf_event
*event
,
5573 struct task_struct
*task
)
5575 struct perf_output_handle handle
;
5576 struct perf_sample_data sample
;
5577 struct perf_read_event read_event
= {
5579 .type
= PERF_RECORD_READ
,
5581 .size
= sizeof(read_event
) + event
->read_size
,
5583 .pid
= perf_event_pid(event
, task
),
5584 .tid
= perf_event_tid(event
, task
),
5588 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5589 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5593 perf_output_put(&handle
, read_event
);
5594 perf_output_read(&handle
, event
);
5595 perf_event__output_id_sample(event
, &handle
, &sample
);
5597 perf_output_end(&handle
);
5600 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5603 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5604 perf_event_aux_output_cb output
,
5607 struct perf_event
*event
;
5609 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5610 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5612 if (!event_filter_match(event
))
5614 output(event
, data
);
5619 perf_event_aux_task_ctx(perf_event_aux_output_cb output
, void *data
,
5620 struct perf_event_context
*task_ctx
)
5624 perf_event_aux_ctx(task_ctx
, output
, data
);
5630 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5631 struct perf_event_context
*task_ctx
)
5633 struct perf_cpu_context
*cpuctx
;
5634 struct perf_event_context
*ctx
;
5639 * If we have task_ctx != NULL we only notify
5640 * the task context itself. The task_ctx is set
5641 * only for EXIT events before releasing task
5645 perf_event_aux_task_ctx(output
, data
, task_ctx
);
5650 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5651 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5652 if (cpuctx
->unique_pmu
!= pmu
)
5654 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5655 ctxn
= pmu
->task_ctx_nr
;
5658 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5660 perf_event_aux_ctx(ctx
, output
, data
);
5662 put_cpu_ptr(pmu
->pmu_cpu_context
);
5668 * task tracking -- fork/exit
5670 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5673 struct perf_task_event
{
5674 struct task_struct
*task
;
5675 struct perf_event_context
*task_ctx
;
5678 struct perf_event_header header
;
5688 static int perf_event_task_match(struct perf_event
*event
)
5690 return event
->attr
.comm
|| event
->attr
.mmap
||
5691 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5695 static void perf_event_task_output(struct perf_event
*event
,
5698 struct perf_task_event
*task_event
= data
;
5699 struct perf_output_handle handle
;
5700 struct perf_sample_data sample
;
5701 struct task_struct
*task
= task_event
->task
;
5702 int ret
, size
= task_event
->event_id
.header
.size
;
5704 if (!perf_event_task_match(event
))
5707 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5709 ret
= perf_output_begin(&handle
, event
,
5710 task_event
->event_id
.header
.size
);
5714 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5715 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5717 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5718 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5720 task_event
->event_id
.time
= perf_event_clock(event
);
5722 perf_output_put(&handle
, task_event
->event_id
);
5724 perf_event__output_id_sample(event
, &handle
, &sample
);
5726 perf_output_end(&handle
);
5728 task_event
->event_id
.header
.size
= size
;
5731 static void perf_event_task(struct task_struct
*task
,
5732 struct perf_event_context
*task_ctx
,
5735 struct perf_task_event task_event
;
5737 if (!atomic_read(&nr_comm_events
) &&
5738 !atomic_read(&nr_mmap_events
) &&
5739 !atomic_read(&nr_task_events
))
5742 task_event
= (struct perf_task_event
){
5744 .task_ctx
= task_ctx
,
5747 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5749 .size
= sizeof(task_event
.event_id
),
5759 perf_event_aux(perf_event_task_output
,
5764 void perf_event_fork(struct task_struct
*task
)
5766 perf_event_task(task
, NULL
, 1);
5773 struct perf_comm_event
{
5774 struct task_struct
*task
;
5779 struct perf_event_header header
;
5786 static int perf_event_comm_match(struct perf_event
*event
)
5788 return event
->attr
.comm
;
5791 static void perf_event_comm_output(struct perf_event
*event
,
5794 struct perf_comm_event
*comm_event
= data
;
5795 struct perf_output_handle handle
;
5796 struct perf_sample_data sample
;
5797 int size
= comm_event
->event_id
.header
.size
;
5800 if (!perf_event_comm_match(event
))
5803 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5804 ret
= perf_output_begin(&handle
, event
,
5805 comm_event
->event_id
.header
.size
);
5810 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5811 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5813 perf_output_put(&handle
, comm_event
->event_id
);
5814 __output_copy(&handle
, comm_event
->comm
,
5815 comm_event
->comm_size
);
5817 perf_event__output_id_sample(event
, &handle
, &sample
);
5819 perf_output_end(&handle
);
5821 comm_event
->event_id
.header
.size
= size
;
5824 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5826 char comm
[TASK_COMM_LEN
];
5829 memset(comm
, 0, sizeof(comm
));
5830 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5831 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5833 comm_event
->comm
= comm
;
5834 comm_event
->comm_size
= size
;
5836 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5838 perf_event_aux(perf_event_comm_output
,
5843 void perf_event_comm(struct task_struct
*task
, bool exec
)
5845 struct perf_comm_event comm_event
;
5847 if (!atomic_read(&nr_comm_events
))
5850 comm_event
= (struct perf_comm_event
){
5856 .type
= PERF_RECORD_COMM
,
5857 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5865 perf_event_comm_event(&comm_event
);
5872 struct perf_mmap_event
{
5873 struct vm_area_struct
*vma
;
5875 const char *file_name
;
5883 struct perf_event_header header
;
5893 static int perf_event_mmap_match(struct perf_event
*event
,
5896 struct perf_mmap_event
*mmap_event
= data
;
5897 struct vm_area_struct
*vma
= mmap_event
->vma
;
5898 int executable
= vma
->vm_flags
& VM_EXEC
;
5900 return (!executable
&& event
->attr
.mmap_data
) ||
5901 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5904 static void perf_event_mmap_output(struct perf_event
*event
,
5907 struct perf_mmap_event
*mmap_event
= data
;
5908 struct perf_output_handle handle
;
5909 struct perf_sample_data sample
;
5910 int size
= mmap_event
->event_id
.header
.size
;
5913 if (!perf_event_mmap_match(event
, data
))
5916 if (event
->attr
.mmap2
) {
5917 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5918 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5919 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5920 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5921 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5922 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5923 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5926 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5927 ret
= perf_output_begin(&handle
, event
,
5928 mmap_event
->event_id
.header
.size
);
5932 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5933 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5935 perf_output_put(&handle
, mmap_event
->event_id
);
5937 if (event
->attr
.mmap2
) {
5938 perf_output_put(&handle
, mmap_event
->maj
);
5939 perf_output_put(&handle
, mmap_event
->min
);
5940 perf_output_put(&handle
, mmap_event
->ino
);
5941 perf_output_put(&handle
, mmap_event
->ino_generation
);
5942 perf_output_put(&handle
, mmap_event
->prot
);
5943 perf_output_put(&handle
, mmap_event
->flags
);
5946 __output_copy(&handle
, mmap_event
->file_name
,
5947 mmap_event
->file_size
);
5949 perf_event__output_id_sample(event
, &handle
, &sample
);
5951 perf_output_end(&handle
);
5953 mmap_event
->event_id
.header
.size
= size
;
5956 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5958 struct vm_area_struct
*vma
= mmap_event
->vma
;
5959 struct file
*file
= vma
->vm_file
;
5960 int maj
= 0, min
= 0;
5961 u64 ino
= 0, gen
= 0;
5962 u32 prot
= 0, flags
= 0;
5969 struct inode
*inode
;
5972 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5978 * d_path() works from the end of the rb backwards, so we
5979 * need to add enough zero bytes after the string to handle
5980 * the 64bit alignment we do later.
5982 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
5987 inode
= file_inode(vma
->vm_file
);
5988 dev
= inode
->i_sb
->s_dev
;
5990 gen
= inode
->i_generation
;
5994 if (vma
->vm_flags
& VM_READ
)
5996 if (vma
->vm_flags
& VM_WRITE
)
5998 if (vma
->vm_flags
& VM_EXEC
)
6001 if (vma
->vm_flags
& VM_MAYSHARE
)
6004 flags
= MAP_PRIVATE
;
6006 if (vma
->vm_flags
& VM_DENYWRITE
)
6007 flags
|= MAP_DENYWRITE
;
6008 if (vma
->vm_flags
& VM_MAYEXEC
)
6009 flags
|= MAP_EXECUTABLE
;
6010 if (vma
->vm_flags
& VM_LOCKED
)
6011 flags
|= MAP_LOCKED
;
6012 if (vma
->vm_flags
& VM_HUGETLB
)
6013 flags
|= MAP_HUGETLB
;
6017 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6018 name
= (char *) vma
->vm_ops
->name(vma
);
6023 name
= (char *)arch_vma_name(vma
);
6027 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6028 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6032 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6033 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6043 strlcpy(tmp
, name
, sizeof(tmp
));
6047 * Since our buffer works in 8 byte units we need to align our string
6048 * size to a multiple of 8. However, we must guarantee the tail end is
6049 * zero'd out to avoid leaking random bits to userspace.
6051 size
= strlen(name
)+1;
6052 while (!IS_ALIGNED(size
, sizeof(u64
)))
6053 name
[size
++] = '\0';
6055 mmap_event
->file_name
= name
;
6056 mmap_event
->file_size
= size
;
6057 mmap_event
->maj
= maj
;
6058 mmap_event
->min
= min
;
6059 mmap_event
->ino
= ino
;
6060 mmap_event
->ino_generation
= gen
;
6061 mmap_event
->prot
= prot
;
6062 mmap_event
->flags
= flags
;
6064 if (!(vma
->vm_flags
& VM_EXEC
))
6065 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6067 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6069 perf_event_aux(perf_event_mmap_output
,
6076 void perf_event_mmap(struct vm_area_struct
*vma
)
6078 struct perf_mmap_event mmap_event
;
6080 if (!atomic_read(&nr_mmap_events
))
6083 mmap_event
= (struct perf_mmap_event
){
6089 .type
= PERF_RECORD_MMAP
,
6090 .misc
= PERF_RECORD_MISC_USER
,
6095 .start
= vma
->vm_start
,
6096 .len
= vma
->vm_end
- vma
->vm_start
,
6097 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6099 /* .maj (attr_mmap2 only) */
6100 /* .min (attr_mmap2 only) */
6101 /* .ino (attr_mmap2 only) */
6102 /* .ino_generation (attr_mmap2 only) */
6103 /* .prot (attr_mmap2 only) */
6104 /* .flags (attr_mmap2 only) */
6107 perf_event_mmap_event(&mmap_event
);
6110 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6111 unsigned long size
, u64 flags
)
6113 struct perf_output_handle handle
;
6114 struct perf_sample_data sample
;
6115 struct perf_aux_event
{
6116 struct perf_event_header header
;
6122 .type
= PERF_RECORD_AUX
,
6124 .size
= sizeof(rec
),
6132 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6133 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6138 perf_output_put(&handle
, rec
);
6139 perf_event__output_id_sample(event
, &handle
, &sample
);
6141 perf_output_end(&handle
);
6145 * Lost/dropped samples logging
6147 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6149 struct perf_output_handle handle
;
6150 struct perf_sample_data sample
;
6154 struct perf_event_header header
;
6156 } lost_samples_event
= {
6158 .type
= PERF_RECORD_LOST_SAMPLES
,
6160 .size
= sizeof(lost_samples_event
),
6165 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6167 ret
= perf_output_begin(&handle
, event
,
6168 lost_samples_event
.header
.size
);
6172 perf_output_put(&handle
, lost_samples_event
);
6173 perf_event__output_id_sample(event
, &handle
, &sample
);
6174 perf_output_end(&handle
);
6178 * context_switch tracking
6181 struct perf_switch_event
{
6182 struct task_struct
*task
;
6183 struct task_struct
*next_prev
;
6186 struct perf_event_header header
;
6192 static int perf_event_switch_match(struct perf_event
*event
)
6194 return event
->attr
.context_switch
;
6197 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6199 struct perf_switch_event
*se
= data
;
6200 struct perf_output_handle handle
;
6201 struct perf_sample_data sample
;
6204 if (!perf_event_switch_match(event
))
6207 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6208 if (event
->ctx
->task
) {
6209 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6210 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6212 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6213 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6214 se
->event_id
.next_prev_pid
=
6215 perf_event_pid(event
, se
->next_prev
);
6216 se
->event_id
.next_prev_tid
=
6217 perf_event_tid(event
, se
->next_prev
);
6220 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6222 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6226 if (event
->ctx
->task
)
6227 perf_output_put(&handle
, se
->event_id
.header
);
6229 perf_output_put(&handle
, se
->event_id
);
6231 perf_event__output_id_sample(event
, &handle
, &sample
);
6233 perf_output_end(&handle
);
6236 static void perf_event_switch(struct task_struct
*task
,
6237 struct task_struct
*next_prev
, bool sched_in
)
6239 struct perf_switch_event switch_event
;
6241 /* N.B. caller checks nr_switch_events != 0 */
6243 switch_event
= (struct perf_switch_event
){
6245 .next_prev
= next_prev
,
6249 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6252 /* .next_prev_pid */
6253 /* .next_prev_tid */
6257 perf_event_aux(perf_event_switch_output
,
6263 * IRQ throttle logging
6266 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6268 struct perf_output_handle handle
;
6269 struct perf_sample_data sample
;
6273 struct perf_event_header header
;
6277 } throttle_event
= {
6279 .type
= PERF_RECORD_THROTTLE
,
6281 .size
= sizeof(throttle_event
),
6283 .time
= perf_event_clock(event
),
6284 .id
= primary_event_id(event
),
6285 .stream_id
= event
->id
,
6289 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6291 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6293 ret
= perf_output_begin(&handle
, event
,
6294 throttle_event
.header
.size
);
6298 perf_output_put(&handle
, throttle_event
);
6299 perf_event__output_id_sample(event
, &handle
, &sample
);
6300 perf_output_end(&handle
);
6303 static void perf_log_itrace_start(struct perf_event
*event
)
6305 struct perf_output_handle handle
;
6306 struct perf_sample_data sample
;
6307 struct perf_aux_event
{
6308 struct perf_event_header header
;
6315 event
= event
->parent
;
6317 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6318 event
->hw
.itrace_started
)
6321 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6322 rec
.header
.misc
= 0;
6323 rec
.header
.size
= sizeof(rec
);
6324 rec
.pid
= perf_event_pid(event
, current
);
6325 rec
.tid
= perf_event_tid(event
, current
);
6327 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6328 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6333 perf_output_put(&handle
, rec
);
6334 perf_event__output_id_sample(event
, &handle
, &sample
);
6336 perf_output_end(&handle
);
6340 * Generic event overflow handling, sampling.
6343 static int __perf_event_overflow(struct perf_event
*event
,
6344 int throttle
, struct perf_sample_data
*data
,
6345 struct pt_regs
*regs
)
6347 int events
= atomic_read(&event
->event_limit
);
6348 struct hw_perf_event
*hwc
= &event
->hw
;
6353 * Non-sampling counters might still use the PMI to fold short
6354 * hardware counters, ignore those.
6356 if (unlikely(!is_sampling_event(event
)))
6359 seq
= __this_cpu_read(perf_throttled_seq
);
6360 if (seq
!= hwc
->interrupts_seq
) {
6361 hwc
->interrupts_seq
= seq
;
6362 hwc
->interrupts
= 1;
6365 if (unlikely(throttle
6366 && hwc
->interrupts
>= max_samples_per_tick
)) {
6367 __this_cpu_inc(perf_throttled_count
);
6368 hwc
->interrupts
= MAX_INTERRUPTS
;
6369 perf_log_throttle(event
, 0);
6370 tick_nohz_full_kick();
6375 if (event
->attr
.freq
) {
6376 u64 now
= perf_clock();
6377 s64 delta
= now
- hwc
->freq_time_stamp
;
6379 hwc
->freq_time_stamp
= now
;
6381 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6382 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6386 * XXX event_limit might not quite work as expected on inherited
6390 event
->pending_kill
= POLL_IN
;
6391 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6393 event
->pending_kill
= POLL_HUP
;
6394 event
->pending_disable
= 1;
6395 irq_work_queue(&event
->pending
);
6398 if (event
->overflow_handler
)
6399 event
->overflow_handler(event
, data
, regs
);
6401 perf_event_output(event
, data
, regs
);
6403 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6404 event
->pending_wakeup
= 1;
6405 irq_work_queue(&event
->pending
);
6411 int perf_event_overflow(struct perf_event
*event
,
6412 struct perf_sample_data
*data
,
6413 struct pt_regs
*regs
)
6415 return __perf_event_overflow(event
, 1, data
, regs
);
6419 * Generic software event infrastructure
6422 struct swevent_htable
{
6423 struct swevent_hlist
*swevent_hlist
;
6424 struct mutex hlist_mutex
;
6427 /* Recursion avoidance in each contexts */
6428 int recursion
[PERF_NR_CONTEXTS
];
6431 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6434 * We directly increment event->count and keep a second value in
6435 * event->hw.period_left to count intervals. This period event
6436 * is kept in the range [-sample_period, 0] so that we can use the
6440 u64
perf_swevent_set_period(struct perf_event
*event
)
6442 struct hw_perf_event
*hwc
= &event
->hw
;
6443 u64 period
= hwc
->last_period
;
6447 hwc
->last_period
= hwc
->sample_period
;
6450 old
= val
= local64_read(&hwc
->period_left
);
6454 nr
= div64_u64(period
+ val
, period
);
6455 offset
= nr
* period
;
6457 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6463 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6464 struct perf_sample_data
*data
,
6465 struct pt_regs
*regs
)
6467 struct hw_perf_event
*hwc
= &event
->hw
;
6471 overflow
= perf_swevent_set_period(event
);
6473 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6476 for (; overflow
; overflow
--) {
6477 if (__perf_event_overflow(event
, throttle
,
6480 * We inhibit the overflow from happening when
6481 * hwc->interrupts == MAX_INTERRUPTS.
6489 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6490 struct perf_sample_data
*data
,
6491 struct pt_regs
*regs
)
6493 struct hw_perf_event
*hwc
= &event
->hw
;
6495 local64_add(nr
, &event
->count
);
6500 if (!is_sampling_event(event
))
6503 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6505 return perf_swevent_overflow(event
, 1, data
, regs
);
6507 data
->period
= event
->hw
.last_period
;
6509 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6510 return perf_swevent_overflow(event
, 1, data
, regs
);
6512 if (local64_add_negative(nr
, &hwc
->period_left
))
6515 perf_swevent_overflow(event
, 0, data
, regs
);
6518 static int perf_exclude_event(struct perf_event
*event
,
6519 struct pt_regs
*regs
)
6521 if (event
->hw
.state
& PERF_HES_STOPPED
)
6525 if (event
->attr
.exclude_user
&& user_mode(regs
))
6528 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6535 static int perf_swevent_match(struct perf_event
*event
,
6536 enum perf_type_id type
,
6538 struct perf_sample_data
*data
,
6539 struct pt_regs
*regs
)
6541 if (event
->attr
.type
!= type
)
6544 if (event
->attr
.config
!= event_id
)
6547 if (perf_exclude_event(event
, regs
))
6553 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6555 u64 val
= event_id
| (type
<< 32);
6557 return hash_64(val
, SWEVENT_HLIST_BITS
);
6560 static inline struct hlist_head
*
6561 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6563 u64 hash
= swevent_hash(type
, event_id
);
6565 return &hlist
->heads
[hash
];
6568 /* For the read side: events when they trigger */
6569 static inline struct hlist_head
*
6570 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6572 struct swevent_hlist
*hlist
;
6574 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6578 return __find_swevent_head(hlist
, type
, event_id
);
6581 /* For the event head insertion and removal in the hlist */
6582 static inline struct hlist_head
*
6583 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6585 struct swevent_hlist
*hlist
;
6586 u32 event_id
= event
->attr
.config
;
6587 u64 type
= event
->attr
.type
;
6590 * Event scheduling is always serialized against hlist allocation
6591 * and release. Which makes the protected version suitable here.
6592 * The context lock guarantees that.
6594 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6595 lockdep_is_held(&event
->ctx
->lock
));
6599 return __find_swevent_head(hlist
, type
, event_id
);
6602 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6604 struct perf_sample_data
*data
,
6605 struct pt_regs
*regs
)
6607 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6608 struct perf_event
*event
;
6609 struct hlist_head
*head
;
6612 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6616 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6617 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6618 perf_swevent_event(event
, nr
, data
, regs
);
6624 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6626 int perf_swevent_get_recursion_context(void)
6628 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6630 return get_recursion_context(swhash
->recursion
);
6632 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6634 inline void perf_swevent_put_recursion_context(int rctx
)
6636 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6638 put_recursion_context(swhash
->recursion
, rctx
);
6641 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6643 struct perf_sample_data data
;
6645 if (WARN_ON_ONCE(!regs
))
6648 perf_sample_data_init(&data
, addr
, 0);
6649 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6652 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6656 preempt_disable_notrace();
6657 rctx
= perf_swevent_get_recursion_context();
6658 if (unlikely(rctx
< 0))
6661 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6663 perf_swevent_put_recursion_context(rctx
);
6665 preempt_enable_notrace();
6668 static void perf_swevent_read(struct perf_event
*event
)
6672 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6674 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6675 struct hw_perf_event
*hwc
= &event
->hw
;
6676 struct hlist_head
*head
;
6678 if (is_sampling_event(event
)) {
6679 hwc
->last_period
= hwc
->sample_period
;
6680 perf_swevent_set_period(event
);
6683 hwc
->state
= !(flags
& PERF_EF_START
);
6685 head
= find_swevent_head(swhash
, event
);
6686 if (WARN_ON_ONCE(!head
))
6689 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6690 perf_event_update_userpage(event
);
6695 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6697 hlist_del_rcu(&event
->hlist_entry
);
6700 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6702 event
->hw
.state
= 0;
6705 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6707 event
->hw
.state
= PERF_HES_STOPPED
;
6710 /* Deref the hlist from the update side */
6711 static inline struct swevent_hlist
*
6712 swevent_hlist_deref(struct swevent_htable
*swhash
)
6714 return rcu_dereference_protected(swhash
->swevent_hlist
,
6715 lockdep_is_held(&swhash
->hlist_mutex
));
6718 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6720 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6725 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6726 kfree_rcu(hlist
, rcu_head
);
6729 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6731 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6733 mutex_lock(&swhash
->hlist_mutex
);
6735 if (!--swhash
->hlist_refcount
)
6736 swevent_hlist_release(swhash
);
6738 mutex_unlock(&swhash
->hlist_mutex
);
6741 static void swevent_hlist_put(struct perf_event
*event
)
6745 for_each_possible_cpu(cpu
)
6746 swevent_hlist_put_cpu(event
, cpu
);
6749 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6751 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6754 mutex_lock(&swhash
->hlist_mutex
);
6755 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6756 struct swevent_hlist
*hlist
;
6758 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6763 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6765 swhash
->hlist_refcount
++;
6767 mutex_unlock(&swhash
->hlist_mutex
);
6772 static int swevent_hlist_get(struct perf_event
*event
)
6775 int cpu
, failed_cpu
;
6778 for_each_possible_cpu(cpu
) {
6779 err
= swevent_hlist_get_cpu(event
, cpu
);
6789 for_each_possible_cpu(cpu
) {
6790 if (cpu
== failed_cpu
)
6792 swevent_hlist_put_cpu(event
, cpu
);
6799 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6801 static void sw_perf_event_destroy(struct perf_event
*event
)
6803 u64 event_id
= event
->attr
.config
;
6805 WARN_ON(event
->parent
);
6807 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6808 swevent_hlist_put(event
);
6811 static int perf_swevent_init(struct perf_event
*event
)
6813 u64 event_id
= event
->attr
.config
;
6815 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6819 * no branch sampling for software events
6821 if (has_branch_stack(event
))
6825 case PERF_COUNT_SW_CPU_CLOCK
:
6826 case PERF_COUNT_SW_TASK_CLOCK
:
6833 if (event_id
>= PERF_COUNT_SW_MAX
)
6836 if (!event
->parent
) {
6839 err
= swevent_hlist_get(event
);
6843 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6844 event
->destroy
= sw_perf_event_destroy
;
6850 static struct pmu perf_swevent
= {
6851 .task_ctx_nr
= perf_sw_context
,
6853 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6855 .event_init
= perf_swevent_init
,
6856 .add
= perf_swevent_add
,
6857 .del
= perf_swevent_del
,
6858 .start
= perf_swevent_start
,
6859 .stop
= perf_swevent_stop
,
6860 .read
= perf_swevent_read
,
6863 #ifdef CONFIG_EVENT_TRACING
6865 static int perf_tp_filter_match(struct perf_event
*event
,
6866 struct perf_sample_data
*data
)
6868 void *record
= data
->raw
->data
;
6870 /* only top level events have filters set */
6872 event
= event
->parent
;
6874 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6879 static int perf_tp_event_match(struct perf_event
*event
,
6880 struct perf_sample_data
*data
,
6881 struct pt_regs
*regs
)
6883 if (event
->hw
.state
& PERF_HES_STOPPED
)
6886 * All tracepoints are from kernel-space.
6888 if (event
->attr
.exclude_kernel
)
6891 if (!perf_tp_filter_match(event
, data
))
6897 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6898 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6899 struct task_struct
*task
)
6901 struct perf_sample_data data
;
6902 struct perf_event
*event
;
6904 struct perf_raw_record raw
= {
6909 perf_sample_data_init(&data
, addr
, 0);
6912 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6913 if (perf_tp_event_match(event
, &data
, regs
))
6914 perf_swevent_event(event
, count
, &data
, regs
);
6918 * If we got specified a target task, also iterate its context and
6919 * deliver this event there too.
6921 if (task
&& task
!= current
) {
6922 struct perf_event_context
*ctx
;
6923 struct trace_entry
*entry
= record
;
6926 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6930 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6931 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6933 if (event
->attr
.config
!= entry
->type
)
6935 if (perf_tp_event_match(event
, &data
, regs
))
6936 perf_swevent_event(event
, count
, &data
, regs
);
6942 perf_swevent_put_recursion_context(rctx
);
6944 EXPORT_SYMBOL_GPL(perf_tp_event
);
6946 static void tp_perf_event_destroy(struct perf_event
*event
)
6948 perf_trace_destroy(event
);
6951 static int perf_tp_event_init(struct perf_event
*event
)
6955 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6959 * no branch sampling for tracepoint events
6961 if (has_branch_stack(event
))
6964 err
= perf_trace_init(event
);
6968 event
->destroy
= tp_perf_event_destroy
;
6973 static struct pmu perf_tracepoint
= {
6974 .task_ctx_nr
= perf_sw_context
,
6976 .event_init
= perf_tp_event_init
,
6977 .add
= perf_trace_add
,
6978 .del
= perf_trace_del
,
6979 .start
= perf_swevent_start
,
6980 .stop
= perf_swevent_stop
,
6981 .read
= perf_swevent_read
,
6984 static inline void perf_tp_register(void)
6986 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
6989 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6994 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6997 filter_str
= strndup_user(arg
, PAGE_SIZE
);
6998 if (IS_ERR(filter_str
))
6999 return PTR_ERR(filter_str
);
7001 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
7007 static void perf_event_free_filter(struct perf_event
*event
)
7009 ftrace_profile_free_filter(event
);
7012 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7014 struct bpf_prog
*prog
;
7016 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7019 if (event
->tp_event
->prog
)
7022 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
7023 /* bpf programs can only be attached to u/kprobes */
7026 prog
= bpf_prog_get(prog_fd
);
7028 return PTR_ERR(prog
);
7030 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7031 /* valid fd, but invalid bpf program type */
7036 event
->tp_event
->prog
= prog
;
7041 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7043 struct bpf_prog
*prog
;
7045 if (!event
->tp_event
)
7048 prog
= event
->tp_event
->prog
;
7050 event
->tp_event
->prog
= NULL
;
7057 static inline void perf_tp_register(void)
7061 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7066 static void perf_event_free_filter(struct perf_event
*event
)
7070 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7075 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7078 #endif /* CONFIG_EVENT_TRACING */
7080 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7081 void perf_bp_event(struct perf_event
*bp
, void *data
)
7083 struct perf_sample_data sample
;
7084 struct pt_regs
*regs
= data
;
7086 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7088 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7089 perf_swevent_event(bp
, 1, &sample
, regs
);
7094 * hrtimer based swevent callback
7097 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7099 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7100 struct perf_sample_data data
;
7101 struct pt_regs
*regs
;
7102 struct perf_event
*event
;
7105 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7107 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7108 return HRTIMER_NORESTART
;
7110 event
->pmu
->read(event
);
7112 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7113 regs
= get_irq_regs();
7115 if (regs
&& !perf_exclude_event(event
, regs
)) {
7116 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7117 if (__perf_event_overflow(event
, 1, &data
, regs
))
7118 ret
= HRTIMER_NORESTART
;
7121 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7122 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7127 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7129 struct hw_perf_event
*hwc
= &event
->hw
;
7132 if (!is_sampling_event(event
))
7135 period
= local64_read(&hwc
->period_left
);
7140 local64_set(&hwc
->period_left
, 0);
7142 period
= max_t(u64
, 10000, hwc
->sample_period
);
7144 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7145 HRTIMER_MODE_REL_PINNED
);
7148 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7150 struct hw_perf_event
*hwc
= &event
->hw
;
7152 if (is_sampling_event(event
)) {
7153 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7154 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7156 hrtimer_cancel(&hwc
->hrtimer
);
7160 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7162 struct hw_perf_event
*hwc
= &event
->hw
;
7164 if (!is_sampling_event(event
))
7167 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7168 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7171 * Since hrtimers have a fixed rate, we can do a static freq->period
7172 * mapping and avoid the whole period adjust feedback stuff.
7174 if (event
->attr
.freq
) {
7175 long freq
= event
->attr
.sample_freq
;
7177 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7178 hwc
->sample_period
= event
->attr
.sample_period
;
7179 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7180 hwc
->last_period
= hwc
->sample_period
;
7181 event
->attr
.freq
= 0;
7186 * Software event: cpu wall time clock
7189 static void cpu_clock_event_update(struct perf_event
*event
)
7194 now
= local_clock();
7195 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7196 local64_add(now
- prev
, &event
->count
);
7199 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7201 local64_set(&event
->hw
.prev_count
, local_clock());
7202 perf_swevent_start_hrtimer(event
);
7205 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7207 perf_swevent_cancel_hrtimer(event
);
7208 cpu_clock_event_update(event
);
7211 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7213 if (flags
& PERF_EF_START
)
7214 cpu_clock_event_start(event
, flags
);
7215 perf_event_update_userpage(event
);
7220 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7222 cpu_clock_event_stop(event
, flags
);
7225 static void cpu_clock_event_read(struct perf_event
*event
)
7227 cpu_clock_event_update(event
);
7230 static int cpu_clock_event_init(struct perf_event
*event
)
7232 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7235 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7239 * no branch sampling for software events
7241 if (has_branch_stack(event
))
7244 perf_swevent_init_hrtimer(event
);
7249 static struct pmu perf_cpu_clock
= {
7250 .task_ctx_nr
= perf_sw_context
,
7252 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7254 .event_init
= cpu_clock_event_init
,
7255 .add
= cpu_clock_event_add
,
7256 .del
= cpu_clock_event_del
,
7257 .start
= cpu_clock_event_start
,
7258 .stop
= cpu_clock_event_stop
,
7259 .read
= cpu_clock_event_read
,
7263 * Software event: task time clock
7266 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7271 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7273 local64_add(delta
, &event
->count
);
7276 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7278 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7279 perf_swevent_start_hrtimer(event
);
7282 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7284 perf_swevent_cancel_hrtimer(event
);
7285 task_clock_event_update(event
, event
->ctx
->time
);
7288 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7290 if (flags
& PERF_EF_START
)
7291 task_clock_event_start(event
, flags
);
7292 perf_event_update_userpage(event
);
7297 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7299 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7302 static void task_clock_event_read(struct perf_event
*event
)
7304 u64 now
= perf_clock();
7305 u64 delta
= now
- event
->ctx
->timestamp
;
7306 u64 time
= event
->ctx
->time
+ delta
;
7308 task_clock_event_update(event
, time
);
7311 static int task_clock_event_init(struct perf_event
*event
)
7313 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7316 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7320 * no branch sampling for software events
7322 if (has_branch_stack(event
))
7325 perf_swevent_init_hrtimer(event
);
7330 static struct pmu perf_task_clock
= {
7331 .task_ctx_nr
= perf_sw_context
,
7333 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7335 .event_init
= task_clock_event_init
,
7336 .add
= task_clock_event_add
,
7337 .del
= task_clock_event_del
,
7338 .start
= task_clock_event_start
,
7339 .stop
= task_clock_event_stop
,
7340 .read
= task_clock_event_read
,
7343 static void perf_pmu_nop_void(struct pmu
*pmu
)
7347 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7351 static int perf_pmu_nop_int(struct pmu
*pmu
)
7356 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7358 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7360 __this_cpu_write(nop_txn_flags
, flags
);
7362 if (flags
& ~PERF_PMU_TXN_ADD
)
7365 perf_pmu_disable(pmu
);
7368 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7370 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7372 __this_cpu_write(nop_txn_flags
, 0);
7374 if (flags
& ~PERF_PMU_TXN_ADD
)
7377 perf_pmu_enable(pmu
);
7381 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7383 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7385 __this_cpu_write(nop_txn_flags
, 0);
7387 if (flags
& ~PERF_PMU_TXN_ADD
)
7390 perf_pmu_enable(pmu
);
7393 static int perf_event_idx_default(struct perf_event
*event
)
7399 * Ensures all contexts with the same task_ctx_nr have the same
7400 * pmu_cpu_context too.
7402 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7409 list_for_each_entry(pmu
, &pmus
, entry
) {
7410 if (pmu
->task_ctx_nr
== ctxn
)
7411 return pmu
->pmu_cpu_context
;
7417 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7421 for_each_possible_cpu(cpu
) {
7422 struct perf_cpu_context
*cpuctx
;
7424 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7426 if (cpuctx
->unique_pmu
== old_pmu
)
7427 cpuctx
->unique_pmu
= pmu
;
7431 static void free_pmu_context(struct pmu
*pmu
)
7435 mutex_lock(&pmus_lock
);
7437 * Like a real lame refcount.
7439 list_for_each_entry(i
, &pmus
, entry
) {
7440 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7441 update_pmu_context(i
, pmu
);
7446 free_percpu(pmu
->pmu_cpu_context
);
7448 mutex_unlock(&pmus_lock
);
7450 static struct idr pmu_idr
;
7453 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7455 struct pmu
*pmu
= dev_get_drvdata(dev
);
7457 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7459 static DEVICE_ATTR_RO(type
);
7462 perf_event_mux_interval_ms_show(struct device
*dev
,
7463 struct device_attribute
*attr
,
7466 struct pmu
*pmu
= dev_get_drvdata(dev
);
7468 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7471 static DEFINE_MUTEX(mux_interval_mutex
);
7474 perf_event_mux_interval_ms_store(struct device
*dev
,
7475 struct device_attribute
*attr
,
7476 const char *buf
, size_t count
)
7478 struct pmu
*pmu
= dev_get_drvdata(dev
);
7479 int timer
, cpu
, ret
;
7481 ret
= kstrtoint(buf
, 0, &timer
);
7488 /* same value, noting to do */
7489 if (timer
== pmu
->hrtimer_interval_ms
)
7492 mutex_lock(&mux_interval_mutex
);
7493 pmu
->hrtimer_interval_ms
= timer
;
7495 /* update all cpuctx for this PMU */
7497 for_each_online_cpu(cpu
) {
7498 struct perf_cpu_context
*cpuctx
;
7499 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7500 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7502 cpu_function_call(cpu
,
7503 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7506 mutex_unlock(&mux_interval_mutex
);
7510 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7512 static struct attribute
*pmu_dev_attrs
[] = {
7513 &dev_attr_type
.attr
,
7514 &dev_attr_perf_event_mux_interval_ms
.attr
,
7517 ATTRIBUTE_GROUPS(pmu_dev
);
7519 static int pmu_bus_running
;
7520 static struct bus_type pmu_bus
= {
7521 .name
= "event_source",
7522 .dev_groups
= pmu_dev_groups
,
7525 static void pmu_dev_release(struct device
*dev
)
7530 static int pmu_dev_alloc(struct pmu
*pmu
)
7534 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7538 pmu
->dev
->groups
= pmu
->attr_groups
;
7539 device_initialize(pmu
->dev
);
7540 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7544 dev_set_drvdata(pmu
->dev
, pmu
);
7545 pmu
->dev
->bus
= &pmu_bus
;
7546 pmu
->dev
->release
= pmu_dev_release
;
7547 ret
= device_add(pmu
->dev
);
7555 put_device(pmu
->dev
);
7559 static struct lock_class_key cpuctx_mutex
;
7560 static struct lock_class_key cpuctx_lock
;
7562 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7566 mutex_lock(&pmus_lock
);
7568 pmu
->pmu_disable_count
= alloc_percpu(int);
7569 if (!pmu
->pmu_disable_count
)
7578 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7586 if (pmu_bus_running
) {
7587 ret
= pmu_dev_alloc(pmu
);
7593 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7594 if (pmu
->pmu_cpu_context
)
7595 goto got_cpu_context
;
7598 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7599 if (!pmu
->pmu_cpu_context
)
7602 for_each_possible_cpu(cpu
) {
7603 struct perf_cpu_context
*cpuctx
;
7605 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7606 __perf_event_init_context(&cpuctx
->ctx
);
7607 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7608 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7609 cpuctx
->ctx
.pmu
= pmu
;
7611 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7613 cpuctx
->unique_pmu
= pmu
;
7617 if (!pmu
->start_txn
) {
7618 if (pmu
->pmu_enable
) {
7620 * If we have pmu_enable/pmu_disable calls, install
7621 * transaction stubs that use that to try and batch
7622 * hardware accesses.
7624 pmu
->start_txn
= perf_pmu_start_txn
;
7625 pmu
->commit_txn
= perf_pmu_commit_txn
;
7626 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7628 pmu
->start_txn
= perf_pmu_nop_txn
;
7629 pmu
->commit_txn
= perf_pmu_nop_int
;
7630 pmu
->cancel_txn
= perf_pmu_nop_void
;
7634 if (!pmu
->pmu_enable
) {
7635 pmu
->pmu_enable
= perf_pmu_nop_void
;
7636 pmu
->pmu_disable
= perf_pmu_nop_void
;
7639 if (!pmu
->event_idx
)
7640 pmu
->event_idx
= perf_event_idx_default
;
7642 list_add_rcu(&pmu
->entry
, &pmus
);
7643 atomic_set(&pmu
->exclusive_cnt
, 0);
7646 mutex_unlock(&pmus_lock
);
7651 device_del(pmu
->dev
);
7652 put_device(pmu
->dev
);
7655 if (pmu
->type
>= PERF_TYPE_MAX
)
7656 idr_remove(&pmu_idr
, pmu
->type
);
7659 free_percpu(pmu
->pmu_disable_count
);
7662 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7664 void perf_pmu_unregister(struct pmu
*pmu
)
7666 mutex_lock(&pmus_lock
);
7667 list_del_rcu(&pmu
->entry
);
7668 mutex_unlock(&pmus_lock
);
7671 * We dereference the pmu list under both SRCU and regular RCU, so
7672 * synchronize against both of those.
7674 synchronize_srcu(&pmus_srcu
);
7677 free_percpu(pmu
->pmu_disable_count
);
7678 if (pmu
->type
>= PERF_TYPE_MAX
)
7679 idr_remove(&pmu_idr
, pmu
->type
);
7680 device_del(pmu
->dev
);
7681 put_device(pmu
->dev
);
7682 free_pmu_context(pmu
);
7684 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7686 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7688 struct perf_event_context
*ctx
= NULL
;
7691 if (!try_module_get(pmu
->module
))
7694 if (event
->group_leader
!= event
) {
7696 * This ctx->mutex can nest when we're called through
7697 * inheritance. See the perf_event_ctx_lock_nested() comment.
7699 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7700 SINGLE_DEPTH_NESTING
);
7705 ret
= pmu
->event_init(event
);
7708 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7711 module_put(pmu
->module
);
7716 static struct pmu
*perf_init_event(struct perf_event
*event
)
7718 struct pmu
*pmu
= NULL
;
7722 idx
= srcu_read_lock(&pmus_srcu
);
7725 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7728 ret
= perf_try_init_event(pmu
, event
);
7734 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7735 ret
= perf_try_init_event(pmu
, event
);
7739 if (ret
!= -ENOENT
) {
7744 pmu
= ERR_PTR(-ENOENT
);
7746 srcu_read_unlock(&pmus_srcu
, idx
);
7751 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7756 if (is_cgroup_event(event
))
7757 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7760 static void account_event(struct perf_event
*event
)
7765 if (event
->attach_state
& PERF_ATTACH_TASK
)
7766 static_key_slow_inc(&perf_sched_events
.key
);
7767 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7768 atomic_inc(&nr_mmap_events
);
7769 if (event
->attr
.comm
)
7770 atomic_inc(&nr_comm_events
);
7771 if (event
->attr
.task
)
7772 atomic_inc(&nr_task_events
);
7773 if (event
->attr
.freq
) {
7774 if (atomic_inc_return(&nr_freq_events
) == 1)
7775 tick_nohz_full_kick_all();
7777 if (event
->attr
.context_switch
) {
7778 atomic_inc(&nr_switch_events
);
7779 static_key_slow_inc(&perf_sched_events
.key
);
7781 if (has_branch_stack(event
))
7782 static_key_slow_inc(&perf_sched_events
.key
);
7783 if (is_cgroup_event(event
))
7784 static_key_slow_inc(&perf_sched_events
.key
);
7786 account_event_cpu(event
, event
->cpu
);
7790 * Allocate and initialize a event structure
7792 static struct perf_event
*
7793 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7794 struct task_struct
*task
,
7795 struct perf_event
*group_leader
,
7796 struct perf_event
*parent_event
,
7797 perf_overflow_handler_t overflow_handler
,
7798 void *context
, int cgroup_fd
)
7801 struct perf_event
*event
;
7802 struct hw_perf_event
*hwc
;
7805 if ((unsigned)cpu
>= nr_cpu_ids
) {
7806 if (!task
|| cpu
!= -1)
7807 return ERR_PTR(-EINVAL
);
7810 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7812 return ERR_PTR(-ENOMEM
);
7815 * Single events are their own group leaders, with an
7816 * empty sibling list:
7819 group_leader
= event
;
7821 mutex_init(&event
->child_mutex
);
7822 INIT_LIST_HEAD(&event
->child_list
);
7824 INIT_LIST_HEAD(&event
->group_entry
);
7825 INIT_LIST_HEAD(&event
->event_entry
);
7826 INIT_LIST_HEAD(&event
->sibling_list
);
7827 INIT_LIST_HEAD(&event
->rb_entry
);
7828 INIT_LIST_HEAD(&event
->active_entry
);
7829 INIT_HLIST_NODE(&event
->hlist_entry
);
7832 init_waitqueue_head(&event
->waitq
);
7833 init_irq_work(&event
->pending
, perf_pending_event
);
7835 mutex_init(&event
->mmap_mutex
);
7837 atomic_long_set(&event
->refcount
, 1);
7839 event
->attr
= *attr
;
7840 event
->group_leader
= group_leader
;
7844 event
->parent
= parent_event
;
7846 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7847 event
->id
= atomic64_inc_return(&perf_event_id
);
7849 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7852 event
->attach_state
= PERF_ATTACH_TASK
;
7854 * XXX pmu::event_init needs to know what task to account to
7855 * and we cannot use the ctx information because we need the
7856 * pmu before we get a ctx.
7858 event
->hw
.target
= task
;
7861 event
->clock
= &local_clock
;
7863 event
->clock
= parent_event
->clock
;
7865 if (!overflow_handler
&& parent_event
) {
7866 overflow_handler
= parent_event
->overflow_handler
;
7867 context
= parent_event
->overflow_handler_context
;
7870 event
->overflow_handler
= overflow_handler
;
7871 event
->overflow_handler_context
= context
;
7873 perf_event__state_init(event
);
7878 hwc
->sample_period
= attr
->sample_period
;
7879 if (attr
->freq
&& attr
->sample_freq
)
7880 hwc
->sample_period
= 1;
7881 hwc
->last_period
= hwc
->sample_period
;
7883 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7886 * we currently do not support PERF_FORMAT_GROUP on inherited events
7888 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7891 if (!has_branch_stack(event
))
7892 event
->attr
.branch_sample_type
= 0;
7894 if (cgroup_fd
!= -1) {
7895 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7900 pmu
= perf_init_event(event
);
7903 else if (IS_ERR(pmu
)) {
7908 err
= exclusive_event_init(event
);
7912 if (!event
->parent
) {
7913 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7914 err
= get_callchain_buffers();
7923 exclusive_event_destroy(event
);
7927 event
->destroy(event
);
7928 module_put(pmu
->module
);
7930 if (is_cgroup_event(event
))
7931 perf_detach_cgroup(event
);
7933 put_pid_ns(event
->ns
);
7936 return ERR_PTR(err
);
7939 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
7940 struct perf_event_attr
*attr
)
7945 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
7949 * zero the full structure, so that a short copy will be nice.
7951 memset(attr
, 0, sizeof(*attr
));
7953 ret
= get_user(size
, &uattr
->size
);
7957 if (size
> PAGE_SIZE
) /* silly large */
7960 if (!size
) /* abi compat */
7961 size
= PERF_ATTR_SIZE_VER0
;
7963 if (size
< PERF_ATTR_SIZE_VER0
)
7967 * If we're handed a bigger struct than we know of,
7968 * ensure all the unknown bits are 0 - i.e. new
7969 * user-space does not rely on any kernel feature
7970 * extensions we dont know about yet.
7972 if (size
> sizeof(*attr
)) {
7973 unsigned char __user
*addr
;
7974 unsigned char __user
*end
;
7977 addr
= (void __user
*)uattr
+ sizeof(*attr
);
7978 end
= (void __user
*)uattr
+ size
;
7980 for (; addr
< end
; addr
++) {
7981 ret
= get_user(val
, addr
);
7987 size
= sizeof(*attr
);
7990 ret
= copy_from_user(attr
, uattr
, size
);
7994 if (attr
->__reserved_1
)
7997 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
8000 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
8003 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
8004 u64 mask
= attr
->branch_sample_type
;
8006 /* only using defined bits */
8007 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
8010 /* at least one branch bit must be set */
8011 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
8014 /* propagate priv level, when not set for branch */
8015 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
8017 /* exclude_kernel checked on syscall entry */
8018 if (!attr
->exclude_kernel
)
8019 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8021 if (!attr
->exclude_user
)
8022 mask
|= PERF_SAMPLE_BRANCH_USER
;
8024 if (!attr
->exclude_hv
)
8025 mask
|= PERF_SAMPLE_BRANCH_HV
;
8027 * adjust user setting (for HW filter setup)
8029 attr
->branch_sample_type
= mask
;
8031 /* privileged levels capture (kernel, hv): check permissions */
8032 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8033 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8037 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8038 ret
= perf_reg_validate(attr
->sample_regs_user
);
8043 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8044 if (!arch_perf_have_user_stack_dump())
8048 * We have __u32 type for the size, but so far
8049 * we can only use __u16 as maximum due to the
8050 * __u16 sample size limit.
8052 if (attr
->sample_stack_user
>= USHRT_MAX
)
8054 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8058 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8059 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8064 put_user(sizeof(*attr
), &uattr
->size
);
8070 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8072 struct ring_buffer
*rb
= NULL
;
8078 /* don't allow circular references */
8079 if (event
== output_event
)
8083 * Don't allow cross-cpu buffers
8085 if (output_event
->cpu
!= event
->cpu
)
8089 * If its not a per-cpu rb, it must be the same task.
8091 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8095 * Mixing clocks in the same buffer is trouble you don't need.
8097 if (output_event
->clock
!= event
->clock
)
8101 * If both events generate aux data, they must be on the same PMU
8103 if (has_aux(event
) && has_aux(output_event
) &&
8104 event
->pmu
!= output_event
->pmu
)
8108 mutex_lock(&event
->mmap_mutex
);
8109 /* Can't redirect output if we've got an active mmap() */
8110 if (atomic_read(&event
->mmap_count
))
8114 /* get the rb we want to redirect to */
8115 rb
= ring_buffer_get(output_event
);
8120 ring_buffer_attach(event
, rb
);
8124 mutex_unlock(&event
->mmap_mutex
);
8130 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8136 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8139 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8141 bool nmi_safe
= false;
8144 case CLOCK_MONOTONIC
:
8145 event
->clock
= &ktime_get_mono_fast_ns
;
8149 case CLOCK_MONOTONIC_RAW
:
8150 event
->clock
= &ktime_get_raw_fast_ns
;
8154 case CLOCK_REALTIME
:
8155 event
->clock
= &ktime_get_real_ns
;
8158 case CLOCK_BOOTTIME
:
8159 event
->clock
= &ktime_get_boot_ns
;
8163 event
->clock
= &ktime_get_tai_ns
;
8170 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8177 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8179 * @attr_uptr: event_id type attributes for monitoring/sampling
8182 * @group_fd: group leader event fd
8184 SYSCALL_DEFINE5(perf_event_open
,
8185 struct perf_event_attr __user
*, attr_uptr
,
8186 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8188 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8189 struct perf_event
*event
, *sibling
;
8190 struct perf_event_attr attr
;
8191 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8192 struct file
*event_file
= NULL
;
8193 struct fd group
= {NULL
, 0};
8194 struct task_struct
*task
= NULL
;
8199 int f_flags
= O_RDWR
;
8202 /* for future expandability... */
8203 if (flags
& ~PERF_FLAG_ALL
)
8206 err
= perf_copy_attr(attr_uptr
, &attr
);
8210 if (!attr
.exclude_kernel
) {
8211 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8216 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8219 if (attr
.sample_period
& (1ULL << 63))
8224 * In cgroup mode, the pid argument is used to pass the fd
8225 * opened to the cgroup directory in cgroupfs. The cpu argument
8226 * designates the cpu on which to monitor threads from that
8229 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8232 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8233 f_flags
|= O_CLOEXEC
;
8235 event_fd
= get_unused_fd_flags(f_flags
);
8239 if (group_fd
!= -1) {
8240 err
= perf_fget_light(group_fd
, &group
);
8243 group_leader
= group
.file
->private_data
;
8244 if (flags
& PERF_FLAG_FD_OUTPUT
)
8245 output_event
= group_leader
;
8246 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8247 group_leader
= NULL
;
8250 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8251 task
= find_lively_task_by_vpid(pid
);
8253 err
= PTR_ERR(task
);
8258 if (task
&& group_leader
&&
8259 group_leader
->attr
.inherit
!= attr
.inherit
) {
8266 if (flags
& PERF_FLAG_PID_CGROUP
)
8269 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8270 NULL
, NULL
, cgroup_fd
);
8271 if (IS_ERR(event
)) {
8272 err
= PTR_ERR(event
);
8276 if (is_sampling_event(event
)) {
8277 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8283 account_event(event
);
8286 * Special case software events and allow them to be part of
8287 * any hardware group.
8291 if (attr
.use_clockid
) {
8292 err
= perf_event_set_clock(event
, attr
.clockid
);
8298 (is_software_event(event
) != is_software_event(group_leader
))) {
8299 if (is_software_event(event
)) {
8301 * If event and group_leader are not both a software
8302 * event, and event is, then group leader is not.
8304 * Allow the addition of software events to !software
8305 * groups, this is safe because software events never
8308 pmu
= group_leader
->pmu
;
8309 } else if (is_software_event(group_leader
) &&
8310 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8312 * In case the group is a pure software group, and we
8313 * try to add a hardware event, move the whole group to
8314 * the hardware context.
8321 * Get the target context (task or percpu):
8323 ctx
= find_get_context(pmu
, task
, event
);
8329 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8335 put_task_struct(task
);
8340 * Look up the group leader (we will attach this event to it):
8346 * Do not allow a recursive hierarchy (this new sibling
8347 * becoming part of another group-sibling):
8349 if (group_leader
->group_leader
!= group_leader
)
8352 /* All events in a group should have the same clock */
8353 if (group_leader
->clock
!= event
->clock
)
8357 * Do not allow to attach to a group in a different
8358 * task or CPU context:
8362 * Make sure we're both on the same task, or both
8365 if (group_leader
->ctx
->task
!= ctx
->task
)
8369 * Make sure we're both events for the same CPU;
8370 * grouping events for different CPUs is broken; since
8371 * you can never concurrently schedule them anyhow.
8373 if (group_leader
->cpu
!= event
->cpu
)
8376 if (group_leader
->ctx
!= ctx
)
8381 * Only a group leader can be exclusive or pinned
8383 if (attr
.exclusive
|| attr
.pinned
)
8388 err
= perf_event_set_output(event
, output_event
);
8393 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8395 if (IS_ERR(event_file
)) {
8396 err
= PTR_ERR(event_file
);
8401 gctx
= group_leader
->ctx
;
8402 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8404 mutex_lock(&ctx
->mutex
);
8407 if (!perf_event_validate_size(event
)) {
8413 * Must be under the same ctx::mutex as perf_install_in_context(),
8414 * because we need to serialize with concurrent event creation.
8416 if (!exclusive_event_installable(event
, ctx
)) {
8417 /* exclusive and group stuff are assumed mutually exclusive */
8418 WARN_ON_ONCE(move_group
);
8424 WARN_ON_ONCE(ctx
->parent_ctx
);
8428 * See perf_event_ctx_lock() for comments on the details
8429 * of swizzling perf_event::ctx.
8431 perf_remove_from_context(group_leader
, false);
8433 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8435 perf_remove_from_context(sibling
, false);
8440 * Wait for everybody to stop referencing the events through
8441 * the old lists, before installing it on new lists.
8446 * Install the group siblings before the group leader.
8448 * Because a group leader will try and install the entire group
8449 * (through the sibling list, which is still in-tact), we can
8450 * end up with siblings installed in the wrong context.
8452 * By installing siblings first we NO-OP because they're not
8453 * reachable through the group lists.
8455 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8457 perf_event__state_init(sibling
);
8458 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8463 * Removing from the context ends up with disabled
8464 * event. What we want here is event in the initial
8465 * startup state, ready to be add into new context.
8467 perf_event__state_init(group_leader
);
8468 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8472 * Now that all events are installed in @ctx, nothing
8473 * references @gctx anymore, so drop the last reference we have
8480 * Precalculate sample_data sizes; do while holding ctx::mutex such
8481 * that we're serialized against further additions and before
8482 * perf_install_in_context() which is the point the event is active and
8483 * can use these values.
8485 perf_event__header_size(event
);
8486 perf_event__id_header_size(event
);
8488 perf_install_in_context(ctx
, event
, event
->cpu
);
8489 perf_unpin_context(ctx
);
8492 mutex_unlock(&gctx
->mutex
);
8493 mutex_unlock(&ctx
->mutex
);
8497 event
->owner
= current
;
8499 mutex_lock(¤t
->perf_event_mutex
);
8500 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8501 mutex_unlock(¤t
->perf_event_mutex
);
8504 * Drop the reference on the group_event after placing the
8505 * new event on the sibling_list. This ensures destruction
8506 * of the group leader will find the pointer to itself in
8507 * perf_group_detach().
8510 fd_install(event_fd
, event_file
);
8515 mutex_unlock(&gctx
->mutex
);
8516 mutex_unlock(&ctx
->mutex
);
8520 perf_unpin_context(ctx
);
8528 put_task_struct(task
);
8532 put_unused_fd(event_fd
);
8537 * perf_event_create_kernel_counter
8539 * @attr: attributes of the counter to create
8540 * @cpu: cpu in which the counter is bound
8541 * @task: task to profile (NULL for percpu)
8544 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8545 struct task_struct
*task
,
8546 perf_overflow_handler_t overflow_handler
,
8549 struct perf_event_context
*ctx
;
8550 struct perf_event
*event
;
8554 * Get the target context (task or percpu):
8557 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8558 overflow_handler
, context
, -1);
8559 if (IS_ERR(event
)) {
8560 err
= PTR_ERR(event
);
8564 /* Mark owner so we could distinguish it from user events. */
8565 event
->owner
= EVENT_OWNER_KERNEL
;
8567 account_event(event
);
8569 ctx
= find_get_context(event
->pmu
, task
, event
);
8575 WARN_ON_ONCE(ctx
->parent_ctx
);
8576 mutex_lock(&ctx
->mutex
);
8577 if (!exclusive_event_installable(event
, ctx
)) {
8578 mutex_unlock(&ctx
->mutex
);
8579 perf_unpin_context(ctx
);
8585 perf_install_in_context(ctx
, event
, cpu
);
8586 perf_unpin_context(ctx
);
8587 mutex_unlock(&ctx
->mutex
);
8594 return ERR_PTR(err
);
8596 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8598 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8600 struct perf_event_context
*src_ctx
;
8601 struct perf_event_context
*dst_ctx
;
8602 struct perf_event
*event
, *tmp
;
8605 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8606 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8609 * See perf_event_ctx_lock() for comments on the details
8610 * of swizzling perf_event::ctx.
8612 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8613 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8615 perf_remove_from_context(event
, false);
8616 unaccount_event_cpu(event
, src_cpu
);
8618 list_add(&event
->migrate_entry
, &events
);
8622 * Wait for the events to quiesce before re-instating them.
8627 * Re-instate events in 2 passes.
8629 * Skip over group leaders and only install siblings on this first
8630 * pass, siblings will not get enabled without a leader, however a
8631 * leader will enable its siblings, even if those are still on the old
8634 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8635 if (event
->group_leader
== event
)
8638 list_del(&event
->migrate_entry
);
8639 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8640 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8641 account_event_cpu(event
, dst_cpu
);
8642 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8647 * Once all the siblings are setup properly, install the group leaders
8650 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8651 list_del(&event
->migrate_entry
);
8652 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8653 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8654 account_event_cpu(event
, dst_cpu
);
8655 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8658 mutex_unlock(&dst_ctx
->mutex
);
8659 mutex_unlock(&src_ctx
->mutex
);
8661 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8663 static void sync_child_event(struct perf_event
*child_event
,
8664 struct task_struct
*child
)
8666 struct perf_event
*parent_event
= child_event
->parent
;
8669 if (child_event
->attr
.inherit_stat
)
8670 perf_event_read_event(child_event
, child
);
8672 child_val
= perf_event_count(child_event
);
8675 * Add back the child's count to the parent's count:
8677 atomic64_add(child_val
, &parent_event
->child_count
);
8678 atomic64_add(child_event
->total_time_enabled
,
8679 &parent_event
->child_total_time_enabled
);
8680 atomic64_add(child_event
->total_time_running
,
8681 &parent_event
->child_total_time_running
);
8684 * Remove this event from the parent's list
8686 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8687 mutex_lock(&parent_event
->child_mutex
);
8688 list_del_init(&child_event
->child_list
);
8689 mutex_unlock(&parent_event
->child_mutex
);
8692 * Make sure user/parent get notified, that we just
8695 perf_event_wakeup(parent_event
);
8698 * Release the parent event, if this was the last
8701 put_event(parent_event
);
8705 __perf_event_exit_task(struct perf_event
*child_event
,
8706 struct perf_event_context
*child_ctx
,
8707 struct task_struct
*child
)
8710 * Do not destroy the 'original' grouping; because of the context
8711 * switch optimization the original events could've ended up in a
8712 * random child task.
8714 * If we were to destroy the original group, all group related
8715 * operations would cease to function properly after this random
8718 * Do destroy all inherited groups, we don't care about those
8719 * and being thorough is better.
8721 perf_remove_from_context(child_event
, !!child_event
->parent
);
8724 * It can happen that the parent exits first, and has events
8725 * that are still around due to the child reference. These
8726 * events need to be zapped.
8728 if (child_event
->parent
) {
8729 sync_child_event(child_event
, child
);
8730 free_event(child_event
);
8732 child_event
->state
= PERF_EVENT_STATE_EXIT
;
8733 perf_event_wakeup(child_event
);
8737 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8739 struct perf_event
*child_event
, *next
;
8740 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8741 unsigned long flags
;
8743 if (likely(!child
->perf_event_ctxp
[ctxn
]))
8746 local_irq_save(flags
);
8748 * We can't reschedule here because interrupts are disabled,
8749 * and either child is current or it is a task that can't be
8750 * scheduled, so we are now safe from rescheduling changing
8753 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
8756 * Take the context lock here so that if find_get_context is
8757 * reading child->perf_event_ctxp, we wait until it has
8758 * incremented the context's refcount before we do put_ctx below.
8760 raw_spin_lock(&child_ctx
->lock
);
8761 task_ctx_sched_out(child_ctx
);
8762 child
->perf_event_ctxp
[ctxn
] = NULL
;
8765 * If this context is a clone; unclone it so it can't get
8766 * swapped to another process while we're removing all
8767 * the events from it.
8769 clone_ctx
= unclone_ctx(child_ctx
);
8770 update_context_time(child_ctx
);
8771 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8777 * Report the task dead after unscheduling the events so that we
8778 * won't get any samples after PERF_RECORD_EXIT. We can however still
8779 * get a few PERF_RECORD_READ events.
8781 perf_event_task(child
, child_ctx
, 0);
8784 * We can recurse on the same lock type through:
8786 * __perf_event_exit_task()
8787 * sync_child_event()
8789 * mutex_lock(&ctx->mutex)
8791 * But since its the parent context it won't be the same instance.
8793 mutex_lock(&child_ctx
->mutex
);
8795 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8796 __perf_event_exit_task(child_event
, child_ctx
, child
);
8798 mutex_unlock(&child_ctx
->mutex
);
8804 * When a child task exits, feed back event values to parent events.
8806 void perf_event_exit_task(struct task_struct
*child
)
8808 struct perf_event
*event
, *tmp
;
8811 mutex_lock(&child
->perf_event_mutex
);
8812 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8814 list_del_init(&event
->owner_entry
);
8817 * Ensure the list deletion is visible before we clear
8818 * the owner, closes a race against perf_release() where
8819 * we need to serialize on the owner->perf_event_mutex.
8822 event
->owner
= NULL
;
8824 mutex_unlock(&child
->perf_event_mutex
);
8826 for_each_task_context_nr(ctxn
)
8827 perf_event_exit_task_context(child
, ctxn
);
8830 * The perf_event_exit_task_context calls perf_event_task
8831 * with child's task_ctx, which generates EXIT events for
8832 * child contexts and sets child->perf_event_ctxp[] to NULL.
8833 * At this point we need to send EXIT events to cpu contexts.
8835 perf_event_task(child
, NULL
, 0);
8838 static void perf_free_event(struct perf_event
*event
,
8839 struct perf_event_context
*ctx
)
8841 struct perf_event
*parent
= event
->parent
;
8843 if (WARN_ON_ONCE(!parent
))
8846 mutex_lock(&parent
->child_mutex
);
8847 list_del_init(&event
->child_list
);
8848 mutex_unlock(&parent
->child_mutex
);
8852 raw_spin_lock_irq(&ctx
->lock
);
8853 perf_group_detach(event
);
8854 list_del_event(event
, ctx
);
8855 raw_spin_unlock_irq(&ctx
->lock
);
8860 * Free an unexposed, unused context as created by inheritance by
8861 * perf_event_init_task below, used by fork() in case of fail.
8863 * Not all locks are strictly required, but take them anyway to be nice and
8864 * help out with the lockdep assertions.
8866 void perf_event_free_task(struct task_struct
*task
)
8868 struct perf_event_context
*ctx
;
8869 struct perf_event
*event
, *tmp
;
8872 for_each_task_context_nr(ctxn
) {
8873 ctx
= task
->perf_event_ctxp
[ctxn
];
8877 mutex_lock(&ctx
->mutex
);
8879 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8881 perf_free_event(event
, ctx
);
8883 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8885 perf_free_event(event
, ctx
);
8887 if (!list_empty(&ctx
->pinned_groups
) ||
8888 !list_empty(&ctx
->flexible_groups
))
8891 mutex_unlock(&ctx
->mutex
);
8897 void perf_event_delayed_put(struct task_struct
*task
)
8901 for_each_task_context_nr(ctxn
)
8902 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8905 struct perf_event
*perf_event_get(unsigned int fd
)
8909 struct perf_event
*event
;
8911 err
= perf_fget_light(fd
, &f
);
8913 return ERR_PTR(err
);
8915 event
= f
.file
->private_data
;
8916 atomic_long_inc(&event
->refcount
);
8922 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
8925 return ERR_PTR(-EINVAL
);
8927 return &event
->attr
;
8931 * inherit a event from parent task to child task:
8933 static struct perf_event
*
8934 inherit_event(struct perf_event
*parent_event
,
8935 struct task_struct
*parent
,
8936 struct perf_event_context
*parent_ctx
,
8937 struct task_struct
*child
,
8938 struct perf_event
*group_leader
,
8939 struct perf_event_context
*child_ctx
)
8941 enum perf_event_active_state parent_state
= parent_event
->state
;
8942 struct perf_event
*child_event
;
8943 unsigned long flags
;
8946 * Instead of creating recursive hierarchies of events,
8947 * we link inherited events back to the original parent,
8948 * which has a filp for sure, which we use as the reference
8951 if (parent_event
->parent
)
8952 parent_event
= parent_event
->parent
;
8954 child_event
= perf_event_alloc(&parent_event
->attr
,
8957 group_leader
, parent_event
,
8959 if (IS_ERR(child_event
))
8962 if (is_orphaned_event(parent_event
) ||
8963 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
8964 free_event(child_event
);
8971 * Make the child state follow the state of the parent event,
8972 * not its attr.disabled bit. We hold the parent's mutex,
8973 * so we won't race with perf_event_{en, dis}able_family.
8975 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
8976 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
8978 child_event
->state
= PERF_EVENT_STATE_OFF
;
8980 if (parent_event
->attr
.freq
) {
8981 u64 sample_period
= parent_event
->hw
.sample_period
;
8982 struct hw_perf_event
*hwc
= &child_event
->hw
;
8984 hwc
->sample_period
= sample_period
;
8985 hwc
->last_period
= sample_period
;
8987 local64_set(&hwc
->period_left
, sample_period
);
8990 child_event
->ctx
= child_ctx
;
8991 child_event
->overflow_handler
= parent_event
->overflow_handler
;
8992 child_event
->overflow_handler_context
8993 = parent_event
->overflow_handler_context
;
8996 * Precalculate sample_data sizes
8998 perf_event__header_size(child_event
);
8999 perf_event__id_header_size(child_event
);
9002 * Link it up in the child's context:
9004 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
9005 add_event_to_ctx(child_event
, child_ctx
);
9006 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
9009 * Link this into the parent event's child list
9011 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
9012 mutex_lock(&parent_event
->child_mutex
);
9013 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
9014 mutex_unlock(&parent_event
->child_mutex
);
9019 static int inherit_group(struct perf_event
*parent_event
,
9020 struct task_struct
*parent
,
9021 struct perf_event_context
*parent_ctx
,
9022 struct task_struct
*child
,
9023 struct perf_event_context
*child_ctx
)
9025 struct perf_event
*leader
;
9026 struct perf_event
*sub
;
9027 struct perf_event
*child_ctr
;
9029 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9030 child
, NULL
, child_ctx
);
9032 return PTR_ERR(leader
);
9033 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9034 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9035 child
, leader
, child_ctx
);
9036 if (IS_ERR(child_ctr
))
9037 return PTR_ERR(child_ctr
);
9043 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9044 struct perf_event_context
*parent_ctx
,
9045 struct task_struct
*child
, int ctxn
,
9049 struct perf_event_context
*child_ctx
;
9051 if (!event
->attr
.inherit
) {
9056 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9059 * This is executed from the parent task context, so
9060 * inherit events that have been marked for cloning.
9061 * First allocate and initialize a context for the
9065 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9069 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9072 ret
= inherit_group(event
, parent
, parent_ctx
,
9082 * Initialize the perf_event context in task_struct
9084 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9086 struct perf_event_context
*child_ctx
, *parent_ctx
;
9087 struct perf_event_context
*cloned_ctx
;
9088 struct perf_event
*event
;
9089 struct task_struct
*parent
= current
;
9090 int inherited_all
= 1;
9091 unsigned long flags
;
9094 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9098 * If the parent's context is a clone, pin it so it won't get
9101 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9106 * No need to check if parent_ctx != NULL here; since we saw
9107 * it non-NULL earlier, the only reason for it to become NULL
9108 * is if we exit, and since we're currently in the middle of
9109 * a fork we can't be exiting at the same time.
9113 * Lock the parent list. No need to lock the child - not PID
9114 * hashed yet and not running, so nobody can access it.
9116 mutex_lock(&parent_ctx
->mutex
);
9119 * We dont have to disable NMIs - we are only looking at
9120 * the list, not manipulating it:
9122 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9123 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9124 child
, ctxn
, &inherited_all
);
9130 * We can't hold ctx->lock when iterating the ->flexible_group list due
9131 * to allocations, but we need to prevent rotation because
9132 * rotate_ctx() will change the list from interrupt context.
9134 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9135 parent_ctx
->rotate_disable
= 1;
9136 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9138 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9139 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9140 child
, ctxn
, &inherited_all
);
9145 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9146 parent_ctx
->rotate_disable
= 0;
9148 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9150 if (child_ctx
&& inherited_all
) {
9152 * Mark the child context as a clone of the parent
9153 * context, or of whatever the parent is a clone of.
9155 * Note that if the parent is a clone, the holding of
9156 * parent_ctx->lock avoids it from being uncloned.
9158 cloned_ctx
= parent_ctx
->parent_ctx
;
9160 child_ctx
->parent_ctx
= cloned_ctx
;
9161 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9163 child_ctx
->parent_ctx
= parent_ctx
;
9164 child_ctx
->parent_gen
= parent_ctx
->generation
;
9166 get_ctx(child_ctx
->parent_ctx
);
9169 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9170 mutex_unlock(&parent_ctx
->mutex
);
9172 perf_unpin_context(parent_ctx
);
9173 put_ctx(parent_ctx
);
9179 * Initialize the perf_event context in task_struct
9181 int perf_event_init_task(struct task_struct
*child
)
9185 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9186 mutex_init(&child
->perf_event_mutex
);
9187 INIT_LIST_HEAD(&child
->perf_event_list
);
9189 for_each_task_context_nr(ctxn
) {
9190 ret
= perf_event_init_context(child
, ctxn
);
9192 perf_event_free_task(child
);
9200 static void __init
perf_event_init_all_cpus(void)
9202 struct swevent_htable
*swhash
;
9205 for_each_possible_cpu(cpu
) {
9206 swhash
= &per_cpu(swevent_htable
, cpu
);
9207 mutex_init(&swhash
->hlist_mutex
);
9208 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9212 static void perf_event_init_cpu(int cpu
)
9214 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9216 mutex_lock(&swhash
->hlist_mutex
);
9217 if (swhash
->hlist_refcount
> 0) {
9218 struct swevent_hlist
*hlist
;
9220 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9222 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9224 mutex_unlock(&swhash
->hlist_mutex
);
9227 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9228 static void __perf_event_exit_context(void *__info
)
9230 struct remove_event re
= { .detach_group
= true };
9231 struct perf_event_context
*ctx
= __info
;
9234 list_for_each_entry_rcu(re
.event
, &ctx
->event_list
, event_entry
)
9235 __perf_remove_from_context(&re
);
9239 static void perf_event_exit_cpu_context(int cpu
)
9241 struct perf_event_context
*ctx
;
9245 idx
= srcu_read_lock(&pmus_srcu
);
9246 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9247 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9249 mutex_lock(&ctx
->mutex
);
9250 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9251 mutex_unlock(&ctx
->mutex
);
9253 srcu_read_unlock(&pmus_srcu
, idx
);
9256 static void perf_event_exit_cpu(int cpu
)
9258 perf_event_exit_cpu_context(cpu
);
9261 static inline void perf_event_exit_cpu(int cpu
) { }
9265 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9269 for_each_online_cpu(cpu
)
9270 perf_event_exit_cpu(cpu
);
9276 * Run the perf reboot notifier at the very last possible moment so that
9277 * the generic watchdog code runs as long as possible.
9279 static struct notifier_block perf_reboot_notifier
= {
9280 .notifier_call
= perf_reboot
,
9281 .priority
= INT_MIN
,
9285 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9287 unsigned int cpu
= (long)hcpu
;
9289 switch (action
& ~CPU_TASKS_FROZEN
) {
9291 case CPU_UP_PREPARE
:
9292 case CPU_DOWN_FAILED
:
9293 perf_event_init_cpu(cpu
);
9296 case CPU_UP_CANCELED
:
9297 case CPU_DOWN_PREPARE
:
9298 perf_event_exit_cpu(cpu
);
9307 void __init
perf_event_init(void)
9313 perf_event_init_all_cpus();
9314 init_srcu_struct(&pmus_srcu
);
9315 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9316 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9317 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9319 perf_cpu_notifier(perf_cpu_notify
);
9320 register_reboot_notifier(&perf_reboot_notifier
);
9322 ret
= init_hw_breakpoint();
9323 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9325 /* do not patch jump label more than once per second */
9326 jump_label_rate_limit(&perf_sched_events
, HZ
);
9329 * Build time assertion that we keep the data_head at the intended
9330 * location. IOW, validation we got the __reserved[] size right.
9332 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9336 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9339 struct perf_pmu_events_attr
*pmu_attr
=
9340 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9342 if (pmu_attr
->event_str
)
9343 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9348 static int __init
perf_event_sysfs_init(void)
9353 mutex_lock(&pmus_lock
);
9355 ret
= bus_register(&pmu_bus
);
9359 list_for_each_entry(pmu
, &pmus
, entry
) {
9360 if (!pmu
->name
|| pmu
->type
< 0)
9363 ret
= pmu_dev_alloc(pmu
);
9364 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9366 pmu_bus_running
= 1;
9370 mutex_unlock(&pmus_lock
);
9374 device_initcall(perf_event_sysfs_init
);
9376 #ifdef CONFIG_CGROUP_PERF
9377 static struct cgroup_subsys_state
*
9378 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9380 struct perf_cgroup
*jc
;
9382 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9384 return ERR_PTR(-ENOMEM
);
9386 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9389 return ERR_PTR(-ENOMEM
);
9395 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9397 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9399 free_percpu(jc
->info
);
9403 static int __perf_cgroup_move(void *info
)
9405 struct task_struct
*task
= info
;
9407 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9412 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
9414 struct task_struct
*task
;
9415 struct cgroup_subsys_state
*css
;
9417 cgroup_taskset_for_each(task
, css
, tset
)
9418 task_function_call(task
, __perf_cgroup_move
, task
);
9421 struct cgroup_subsys perf_event_cgrp_subsys
= {
9422 .css_alloc
= perf_cgroup_css_alloc
,
9423 .css_free
= perf_cgroup_css_free
,
9424 .attach
= perf_cgroup_attach
,
9426 #endif /* CONFIG_CGROUP_PERF */