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
);
582 cgrp2
= perf_cgroup_from_task(next
, NULL
);
585 * only schedule out current cgroup events if we know
586 * that we are switching to a different cgroup. Otherwise,
587 * do no touch the cgroup events.
590 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
595 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
596 struct task_struct
*task
)
598 struct perf_cgroup
*cgrp1
;
599 struct perf_cgroup
*cgrp2
= NULL
;
603 * we come here when we know perf_cgroup_events > 0
604 * we do not need to pass the ctx here because we know
605 * we are holding the rcu lock
607 cgrp1
= perf_cgroup_from_task(task
, NULL
);
608 cgrp2
= perf_cgroup_from_task(prev
, NULL
);
611 * only need to schedule in cgroup events if we are changing
612 * cgroup during ctxsw. Cgroup events were not scheduled
613 * out of ctxsw out if that was not the case.
616 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
621 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
622 struct perf_event_attr
*attr
,
623 struct perf_event
*group_leader
)
625 struct perf_cgroup
*cgrp
;
626 struct cgroup_subsys_state
*css
;
627 struct fd f
= fdget(fd
);
633 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
634 &perf_event_cgrp_subsys
);
640 cgrp
= container_of(css
, struct perf_cgroup
, css
);
644 * all events in a group must monitor
645 * the same cgroup because a task belongs
646 * to only one perf cgroup at a time
648 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
649 perf_detach_cgroup(event
);
658 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
660 struct perf_cgroup_info
*t
;
661 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
662 event
->shadow_ctx_time
= now
- t
->timestamp
;
666 perf_cgroup_defer_enabled(struct perf_event
*event
)
669 * when the current task's perf cgroup does not match
670 * the event's, we need to remember to call the
671 * perf_mark_enable() function the first time a task with
672 * a matching perf cgroup is scheduled in.
674 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
675 event
->cgrp_defer_enabled
= 1;
679 perf_cgroup_mark_enabled(struct perf_event
*event
,
680 struct perf_event_context
*ctx
)
682 struct perf_event
*sub
;
683 u64 tstamp
= perf_event_time(event
);
685 if (!event
->cgrp_defer_enabled
)
688 event
->cgrp_defer_enabled
= 0;
690 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
691 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
692 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
693 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
694 sub
->cgrp_defer_enabled
= 0;
698 #else /* !CONFIG_CGROUP_PERF */
701 perf_cgroup_match(struct perf_event
*event
)
706 static inline void perf_detach_cgroup(struct perf_event
*event
)
709 static inline int is_cgroup_event(struct perf_event
*event
)
714 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
719 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
723 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
727 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
728 struct task_struct
*next
)
732 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
733 struct task_struct
*task
)
737 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
738 struct perf_event_attr
*attr
,
739 struct perf_event
*group_leader
)
745 perf_cgroup_set_timestamp(struct task_struct
*task
,
746 struct perf_event_context
*ctx
)
751 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
756 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
760 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
766 perf_cgroup_defer_enabled(struct perf_event
*event
)
771 perf_cgroup_mark_enabled(struct perf_event
*event
,
772 struct perf_event_context
*ctx
)
778 * set default to be dependent on timer tick just
781 #define PERF_CPU_HRTIMER (1000 / HZ)
783 * function must be called with interrupts disbled
785 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
787 struct perf_cpu_context
*cpuctx
;
790 WARN_ON(!irqs_disabled());
792 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
793 rotations
= perf_rotate_context(cpuctx
);
795 raw_spin_lock(&cpuctx
->hrtimer_lock
);
797 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
799 cpuctx
->hrtimer_active
= 0;
800 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
802 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
805 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
807 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
808 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
811 /* no multiplexing needed for SW PMU */
812 if (pmu
->task_ctx_nr
== perf_sw_context
)
816 * check default is sane, if not set then force to
817 * default interval (1/tick)
819 interval
= pmu
->hrtimer_interval_ms
;
821 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
823 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
825 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
826 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
827 timer
->function
= perf_mux_hrtimer_handler
;
830 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
832 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
833 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
837 if (pmu
->task_ctx_nr
== perf_sw_context
)
840 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
841 if (!cpuctx
->hrtimer_active
) {
842 cpuctx
->hrtimer_active
= 1;
843 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
844 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
846 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
851 void perf_pmu_disable(struct pmu
*pmu
)
853 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
855 pmu
->pmu_disable(pmu
);
858 void perf_pmu_enable(struct pmu
*pmu
)
860 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
862 pmu
->pmu_enable(pmu
);
865 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
868 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
869 * perf_event_task_tick() are fully serialized because they're strictly cpu
870 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
871 * disabled, while perf_event_task_tick is called from IRQ context.
873 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
875 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
877 WARN_ON(!irqs_disabled());
879 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
881 list_add(&ctx
->active_ctx_list
, head
);
884 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
886 WARN_ON(!irqs_disabled());
888 WARN_ON(list_empty(&ctx
->active_ctx_list
));
890 list_del_init(&ctx
->active_ctx_list
);
893 static void get_ctx(struct perf_event_context
*ctx
)
895 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
898 static void free_ctx(struct rcu_head
*head
)
900 struct perf_event_context
*ctx
;
902 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
903 kfree(ctx
->task_ctx_data
);
907 static void put_ctx(struct perf_event_context
*ctx
)
909 if (atomic_dec_and_test(&ctx
->refcount
)) {
911 put_ctx(ctx
->parent_ctx
);
913 put_task_struct(ctx
->task
);
914 call_rcu(&ctx
->rcu_head
, free_ctx
);
919 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
920 * perf_pmu_migrate_context() we need some magic.
922 * Those places that change perf_event::ctx will hold both
923 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
925 * Lock ordering is by mutex address. There are two other sites where
926 * perf_event_context::mutex nests and those are:
928 * - perf_event_exit_task_context() [ child , 0 ]
929 * __perf_event_exit_task()
931 * put_event() [ parent, 1 ]
933 * - perf_event_init_context() [ parent, 0 ]
934 * inherit_task_group()
939 * perf_try_init_event() [ child , 1 ]
941 * While it appears there is an obvious deadlock here -- the parent and child
942 * nesting levels are inverted between the two. This is in fact safe because
943 * life-time rules separate them. That is an exiting task cannot fork, and a
944 * spawning task cannot (yet) exit.
946 * But remember that that these are parent<->child context relations, and
947 * migration does not affect children, therefore these two orderings should not
950 * The change in perf_event::ctx does not affect children (as claimed above)
951 * because the sys_perf_event_open() case will install a new event and break
952 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
953 * concerned with cpuctx and that doesn't have children.
955 * The places that change perf_event::ctx will issue:
957 * perf_remove_from_context();
959 * perf_install_in_context();
961 * to affect the change. The remove_from_context() + synchronize_rcu() should
962 * quiesce the event, after which we can install it in the new location. This
963 * means that only external vectors (perf_fops, prctl) can perturb the event
964 * while in transit. Therefore all such accessors should also acquire
965 * perf_event_context::mutex to serialize against this.
967 * However; because event->ctx can change while we're waiting to acquire
968 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
972 * task_struct::perf_event_mutex
973 * perf_event_context::mutex
974 * perf_event_context::lock
975 * perf_event::child_mutex;
976 * perf_event::mmap_mutex
979 static struct perf_event_context
*
980 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
982 struct perf_event_context
*ctx
;
986 ctx
= ACCESS_ONCE(event
->ctx
);
987 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
993 mutex_lock_nested(&ctx
->mutex
, nesting
);
994 if (event
->ctx
!= ctx
) {
995 mutex_unlock(&ctx
->mutex
);
1003 static inline struct perf_event_context
*
1004 perf_event_ctx_lock(struct perf_event
*event
)
1006 return perf_event_ctx_lock_nested(event
, 0);
1009 static void perf_event_ctx_unlock(struct perf_event
*event
,
1010 struct perf_event_context
*ctx
)
1012 mutex_unlock(&ctx
->mutex
);
1017 * This must be done under the ctx->lock, such as to serialize against
1018 * context_equiv(), therefore we cannot call put_ctx() since that might end up
1019 * calling scheduler related locks and ctx->lock nests inside those.
1021 static __must_check
struct perf_event_context
*
1022 unclone_ctx(struct perf_event_context
*ctx
)
1024 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
1026 lockdep_assert_held(&ctx
->lock
);
1029 ctx
->parent_ctx
= NULL
;
1035 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1038 * only top level events have the pid namespace they were created in
1041 event
= event
->parent
;
1043 return task_tgid_nr_ns(p
, event
->ns
);
1046 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1049 * only top level events have the pid namespace they were created in
1052 event
= event
->parent
;
1054 return task_pid_nr_ns(p
, event
->ns
);
1058 * If we inherit events we want to return the parent event id
1061 static u64
primary_event_id(struct perf_event
*event
)
1066 id
= event
->parent
->id
;
1072 * Get the perf_event_context for a task and lock it.
1073 * This has to cope with with the fact that until it is locked,
1074 * the context could get moved to another task.
1076 static struct perf_event_context
*
1077 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1079 struct perf_event_context
*ctx
;
1083 * One of the few rules of preemptible RCU is that one cannot do
1084 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1085 * part of the read side critical section was irqs-enabled -- see
1086 * rcu_read_unlock_special().
1088 * Since ctx->lock nests under rq->lock we must ensure the entire read
1089 * side critical section has interrupts disabled.
1091 local_irq_save(*flags
);
1093 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1096 * If this context is a clone of another, it might
1097 * get swapped for another underneath us by
1098 * perf_event_task_sched_out, though the
1099 * rcu_read_lock() protects us from any context
1100 * getting freed. Lock the context and check if it
1101 * got swapped before we could get the lock, and retry
1102 * if so. If we locked the right context, then it
1103 * can't get swapped on us any more.
1105 raw_spin_lock(&ctx
->lock
);
1106 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1107 raw_spin_unlock(&ctx
->lock
);
1109 local_irq_restore(*flags
);
1113 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1114 raw_spin_unlock(&ctx
->lock
);
1120 local_irq_restore(*flags
);
1125 * Get the context for a task and increment its pin_count so it
1126 * can't get swapped to another task. This also increments its
1127 * reference count so that the context can't get freed.
1129 static struct perf_event_context
*
1130 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1132 struct perf_event_context
*ctx
;
1133 unsigned long flags
;
1135 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1138 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1143 static void perf_unpin_context(struct perf_event_context
*ctx
)
1145 unsigned long flags
;
1147 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1149 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1153 * Update the record of the current time in a context.
1155 static void update_context_time(struct perf_event_context
*ctx
)
1157 u64 now
= perf_clock();
1159 ctx
->time
+= now
- ctx
->timestamp
;
1160 ctx
->timestamp
= now
;
1163 static u64
perf_event_time(struct perf_event
*event
)
1165 struct perf_event_context
*ctx
= event
->ctx
;
1167 if (is_cgroup_event(event
))
1168 return perf_cgroup_event_time(event
);
1170 return ctx
? ctx
->time
: 0;
1174 * Update the total_time_enabled and total_time_running fields for a event.
1175 * The caller of this function needs to hold the ctx->lock.
1177 static void update_event_times(struct perf_event
*event
)
1179 struct perf_event_context
*ctx
= event
->ctx
;
1182 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1183 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1186 * in cgroup mode, time_enabled represents
1187 * the time the event was enabled AND active
1188 * tasks were in the monitored cgroup. This is
1189 * independent of the activity of the context as
1190 * there may be a mix of cgroup and non-cgroup events.
1192 * That is why we treat cgroup events differently
1195 if (is_cgroup_event(event
))
1196 run_end
= perf_cgroup_event_time(event
);
1197 else if (ctx
->is_active
)
1198 run_end
= ctx
->time
;
1200 run_end
= event
->tstamp_stopped
;
1202 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1204 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1205 run_end
= event
->tstamp_stopped
;
1207 run_end
= perf_event_time(event
);
1209 event
->total_time_running
= run_end
- event
->tstamp_running
;
1214 * Update total_time_enabled and total_time_running for all events in a group.
1216 static void update_group_times(struct perf_event
*leader
)
1218 struct perf_event
*event
;
1220 update_event_times(leader
);
1221 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1222 update_event_times(event
);
1225 static struct list_head
*
1226 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1228 if (event
->attr
.pinned
)
1229 return &ctx
->pinned_groups
;
1231 return &ctx
->flexible_groups
;
1235 * Add a event from the lists for its context.
1236 * Must be called with ctx->mutex and ctx->lock held.
1239 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1241 lockdep_assert_held(&ctx
->lock
);
1243 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1244 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1247 * If we're a stand alone event or group leader, we go to the context
1248 * list, group events are kept attached to the group so that
1249 * perf_group_detach can, at all times, locate all siblings.
1251 if (event
->group_leader
== event
) {
1252 struct list_head
*list
;
1254 if (is_software_event(event
))
1255 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1257 list
= ctx_group_list(event
, ctx
);
1258 list_add_tail(&event
->group_entry
, list
);
1261 if (is_cgroup_event(event
))
1264 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1266 if (event
->attr
.inherit_stat
)
1273 * Initialize event state based on the perf_event_attr::disabled.
1275 static inline void perf_event__state_init(struct perf_event
*event
)
1277 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1278 PERF_EVENT_STATE_INACTIVE
;
1281 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1283 int entry
= sizeof(u64
); /* value */
1287 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1288 size
+= sizeof(u64
);
1290 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1291 size
+= sizeof(u64
);
1293 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1294 entry
+= sizeof(u64
);
1296 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1298 size
+= sizeof(u64
);
1302 event
->read_size
= size
;
1305 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1307 struct perf_sample_data
*data
;
1310 if (sample_type
& PERF_SAMPLE_IP
)
1311 size
+= sizeof(data
->ip
);
1313 if (sample_type
& PERF_SAMPLE_ADDR
)
1314 size
+= sizeof(data
->addr
);
1316 if (sample_type
& PERF_SAMPLE_PERIOD
)
1317 size
+= sizeof(data
->period
);
1319 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1320 size
+= sizeof(data
->weight
);
1322 if (sample_type
& PERF_SAMPLE_READ
)
1323 size
+= event
->read_size
;
1325 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1326 size
+= sizeof(data
->data_src
.val
);
1328 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1329 size
+= sizeof(data
->txn
);
1331 event
->header_size
= size
;
1335 * Called at perf_event creation and when events are attached/detached from a
1338 static void perf_event__header_size(struct perf_event
*event
)
1340 __perf_event_read_size(event
,
1341 event
->group_leader
->nr_siblings
);
1342 __perf_event_header_size(event
, event
->attr
.sample_type
);
1345 static void perf_event__id_header_size(struct perf_event
*event
)
1347 struct perf_sample_data
*data
;
1348 u64 sample_type
= event
->attr
.sample_type
;
1351 if (sample_type
& PERF_SAMPLE_TID
)
1352 size
+= sizeof(data
->tid_entry
);
1354 if (sample_type
& PERF_SAMPLE_TIME
)
1355 size
+= sizeof(data
->time
);
1357 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1358 size
+= sizeof(data
->id
);
1360 if (sample_type
& PERF_SAMPLE_ID
)
1361 size
+= sizeof(data
->id
);
1363 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1364 size
+= sizeof(data
->stream_id
);
1366 if (sample_type
& PERF_SAMPLE_CPU
)
1367 size
+= sizeof(data
->cpu_entry
);
1369 event
->id_header_size
= size
;
1372 static bool perf_event_validate_size(struct perf_event
*event
)
1375 * The values computed here will be over-written when we actually
1378 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1379 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1380 perf_event__id_header_size(event
);
1383 * Sum the lot; should not exceed the 64k limit we have on records.
1384 * Conservative limit to allow for callchains and other variable fields.
1386 if (event
->read_size
+ event
->header_size
+
1387 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1393 static void perf_group_attach(struct perf_event
*event
)
1395 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1398 * We can have double attach due to group movement in perf_event_open.
1400 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1403 event
->attach_state
|= PERF_ATTACH_GROUP
;
1405 if (group_leader
== event
)
1408 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1410 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1411 !is_software_event(event
))
1412 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1414 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1415 group_leader
->nr_siblings
++;
1417 perf_event__header_size(group_leader
);
1419 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1420 perf_event__header_size(pos
);
1424 * Remove a event from the lists for its context.
1425 * Must be called with ctx->mutex and ctx->lock held.
1428 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1430 struct perf_cpu_context
*cpuctx
;
1432 WARN_ON_ONCE(event
->ctx
!= ctx
);
1433 lockdep_assert_held(&ctx
->lock
);
1436 * We can have double detach due to exit/hot-unplug + close.
1438 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1441 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1443 if (is_cgroup_event(event
)) {
1446 * Because cgroup events are always per-cpu events, this will
1447 * always be called from the right CPU.
1449 cpuctx
= __get_cpu_context(ctx
);
1451 * If there are no more cgroup events then clear cgrp to avoid
1452 * stale pointer in update_cgrp_time_from_cpuctx().
1454 if (!ctx
->nr_cgroups
)
1455 cpuctx
->cgrp
= NULL
;
1459 if (event
->attr
.inherit_stat
)
1462 list_del_rcu(&event
->event_entry
);
1464 if (event
->group_leader
== event
)
1465 list_del_init(&event
->group_entry
);
1467 update_group_times(event
);
1470 * If event was in error state, then keep it
1471 * that way, otherwise bogus counts will be
1472 * returned on read(). The only way to get out
1473 * of error state is by explicit re-enabling
1476 if (event
->state
> PERF_EVENT_STATE_OFF
)
1477 event
->state
= PERF_EVENT_STATE_OFF
;
1482 static void perf_group_detach(struct perf_event
*event
)
1484 struct perf_event
*sibling
, *tmp
;
1485 struct list_head
*list
= NULL
;
1488 * We can have double detach due to exit/hot-unplug + close.
1490 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1493 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1496 * If this is a sibling, remove it from its group.
1498 if (event
->group_leader
!= event
) {
1499 list_del_init(&event
->group_entry
);
1500 event
->group_leader
->nr_siblings
--;
1504 if (!list_empty(&event
->group_entry
))
1505 list
= &event
->group_entry
;
1508 * If this was a group event with sibling events then
1509 * upgrade the siblings to singleton events by adding them
1510 * to whatever list we are on.
1512 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1514 list_move_tail(&sibling
->group_entry
, list
);
1515 sibling
->group_leader
= sibling
;
1517 /* Inherit group flags from the previous leader */
1518 sibling
->group_flags
= event
->group_flags
;
1520 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1524 perf_event__header_size(event
->group_leader
);
1526 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1527 perf_event__header_size(tmp
);
1531 * User event without the task.
1533 static bool is_orphaned_event(struct perf_event
*event
)
1535 return event
&& !is_kernel_event(event
) && !event
->owner
;
1539 * Event has a parent but parent's task finished and it's
1540 * alive only because of children holding refference.
1542 static bool is_orphaned_child(struct perf_event
*event
)
1544 return is_orphaned_event(event
->parent
);
1547 static void orphans_remove_work(struct work_struct
*work
);
1549 static void schedule_orphans_remove(struct perf_event_context
*ctx
)
1551 if (!ctx
->task
|| ctx
->orphans_remove_sched
|| !perf_wq
)
1554 if (queue_delayed_work(perf_wq
, &ctx
->orphans_remove
, 1)) {
1556 ctx
->orphans_remove_sched
= true;
1560 static int __init
perf_workqueue_init(void)
1562 perf_wq
= create_singlethread_workqueue("perf");
1563 WARN(!perf_wq
, "failed to create perf workqueue\n");
1564 return perf_wq
? 0 : -1;
1567 core_initcall(perf_workqueue_init
);
1569 static inline int pmu_filter_match(struct perf_event
*event
)
1571 struct pmu
*pmu
= event
->pmu
;
1572 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1576 event_filter_match(struct perf_event
*event
)
1578 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1579 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1583 event_sched_out(struct perf_event
*event
,
1584 struct perf_cpu_context
*cpuctx
,
1585 struct perf_event_context
*ctx
)
1587 u64 tstamp
= perf_event_time(event
);
1590 WARN_ON_ONCE(event
->ctx
!= ctx
);
1591 lockdep_assert_held(&ctx
->lock
);
1594 * An event which could not be activated because of
1595 * filter mismatch still needs to have its timings
1596 * maintained, otherwise bogus information is return
1597 * via read() for time_enabled, time_running:
1599 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1600 && !event_filter_match(event
)) {
1601 delta
= tstamp
- event
->tstamp_stopped
;
1602 event
->tstamp_running
+= delta
;
1603 event
->tstamp_stopped
= tstamp
;
1606 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1609 perf_pmu_disable(event
->pmu
);
1611 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1612 if (event
->pending_disable
) {
1613 event
->pending_disable
= 0;
1614 event
->state
= PERF_EVENT_STATE_OFF
;
1616 event
->tstamp_stopped
= tstamp
;
1617 event
->pmu
->del(event
, 0);
1620 if (!is_software_event(event
))
1621 cpuctx
->active_oncpu
--;
1622 if (!--ctx
->nr_active
)
1623 perf_event_ctx_deactivate(ctx
);
1624 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1626 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1627 cpuctx
->exclusive
= 0;
1629 if (is_orphaned_child(event
))
1630 schedule_orphans_remove(ctx
);
1632 perf_pmu_enable(event
->pmu
);
1636 group_sched_out(struct perf_event
*group_event
,
1637 struct perf_cpu_context
*cpuctx
,
1638 struct perf_event_context
*ctx
)
1640 struct perf_event
*event
;
1641 int state
= group_event
->state
;
1643 event_sched_out(group_event
, cpuctx
, ctx
);
1646 * Schedule out siblings (if any):
1648 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1649 event_sched_out(event
, cpuctx
, ctx
);
1651 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1652 cpuctx
->exclusive
= 0;
1655 struct remove_event
{
1656 struct perf_event
*event
;
1660 static void ___perf_remove_from_context(void *info
)
1662 struct remove_event
*re
= info
;
1663 struct perf_event
*event
= re
->event
;
1664 struct perf_event_context
*ctx
= event
->ctx
;
1666 if (re
->detach_group
)
1667 perf_group_detach(event
);
1668 list_del_event(event
, ctx
);
1672 * Cross CPU call to remove a performance event
1674 * We disable the event on the hardware level first. After that we
1675 * remove it from the context list.
1677 static int __perf_remove_from_context(void *info
)
1679 struct remove_event
*re
= info
;
1680 struct perf_event
*event
= re
->event
;
1681 struct perf_event_context
*ctx
= event
->ctx
;
1682 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1684 raw_spin_lock(&ctx
->lock
);
1685 event_sched_out(event
, cpuctx
, ctx
);
1686 if (re
->detach_group
)
1687 perf_group_detach(event
);
1688 list_del_event(event
, ctx
);
1689 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1691 cpuctx
->task_ctx
= NULL
;
1693 raw_spin_unlock(&ctx
->lock
);
1699 * Remove the event from a task's (or a CPU's) list of events.
1701 * CPU events are removed with a smp call. For task events we only
1702 * call when the task is on a CPU.
1704 * If event->ctx is a cloned context, callers must make sure that
1705 * every task struct that event->ctx->task could possibly point to
1706 * remains valid. This is OK when called from perf_release since
1707 * that only calls us on the top-level context, which can't be a clone.
1708 * When called from perf_event_exit_task, it's OK because the
1709 * context has been detached from its task.
1711 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1713 struct perf_event_context
*ctx
= event
->ctx
;
1714 struct remove_event re
= {
1716 .detach_group
= detach_group
,
1719 lockdep_assert_held(&ctx
->mutex
);
1721 event_function_call(event
, __perf_remove_from_context
,
1722 ___perf_remove_from_context
, &re
);
1726 * Cross CPU call to disable a performance event
1728 int __perf_event_disable(void *info
)
1730 struct perf_event
*event
= info
;
1731 struct perf_event_context
*ctx
= event
->ctx
;
1732 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1735 * If this is a per-task event, need to check whether this
1736 * event's task is the current task on this cpu.
1738 * Can trigger due to concurrent perf_event_context_sched_out()
1739 * flipping contexts around.
1741 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1744 raw_spin_lock(&ctx
->lock
);
1747 * If the event is on, turn it off.
1748 * If it is in error state, leave it in error state.
1750 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1751 update_context_time(ctx
);
1752 update_cgrp_time_from_event(event
);
1753 update_group_times(event
);
1754 if (event
== event
->group_leader
)
1755 group_sched_out(event
, cpuctx
, ctx
);
1757 event_sched_out(event
, cpuctx
, ctx
);
1758 event
->state
= PERF_EVENT_STATE_OFF
;
1761 raw_spin_unlock(&ctx
->lock
);
1766 void ___perf_event_disable(void *info
)
1768 struct perf_event
*event
= info
;
1771 * Since we have the lock this context can't be scheduled
1772 * in, so we can change the state safely.
1774 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1775 update_group_times(event
);
1776 event
->state
= PERF_EVENT_STATE_OFF
;
1783 * If event->ctx is a cloned context, callers must make sure that
1784 * every task struct that event->ctx->task could possibly point to
1785 * remains valid. This condition is satisifed when called through
1786 * perf_event_for_each_child or perf_event_for_each because they
1787 * hold the top-level event's child_mutex, so any descendant that
1788 * goes to exit will block in sync_child_event.
1789 * When called from perf_pending_event it's OK because event->ctx
1790 * is the current context on this CPU and preemption is disabled,
1791 * hence we can't get into perf_event_task_sched_out for this context.
1793 static void _perf_event_disable(struct perf_event
*event
)
1795 struct perf_event_context
*ctx
= event
->ctx
;
1797 raw_spin_lock_irq(&ctx
->lock
);
1798 if (event
->state
<= PERF_EVENT_STATE_OFF
) {
1799 raw_spin_unlock_irq(&ctx
->lock
);
1802 raw_spin_unlock_irq(&ctx
->lock
);
1804 event_function_call(event
, __perf_event_disable
,
1805 ___perf_event_disable
, event
);
1809 * Strictly speaking kernel users cannot create groups and therefore this
1810 * interface does not need the perf_event_ctx_lock() magic.
1812 void perf_event_disable(struct perf_event
*event
)
1814 struct perf_event_context
*ctx
;
1816 ctx
= perf_event_ctx_lock(event
);
1817 _perf_event_disable(event
);
1818 perf_event_ctx_unlock(event
, ctx
);
1820 EXPORT_SYMBOL_GPL(perf_event_disable
);
1822 static void perf_set_shadow_time(struct perf_event
*event
,
1823 struct perf_event_context
*ctx
,
1827 * use the correct time source for the time snapshot
1829 * We could get by without this by leveraging the
1830 * fact that to get to this function, the caller
1831 * has most likely already called update_context_time()
1832 * and update_cgrp_time_xx() and thus both timestamp
1833 * are identical (or very close). Given that tstamp is,
1834 * already adjusted for cgroup, we could say that:
1835 * tstamp - ctx->timestamp
1837 * tstamp - cgrp->timestamp.
1839 * Then, in perf_output_read(), the calculation would
1840 * work with no changes because:
1841 * - event is guaranteed scheduled in
1842 * - no scheduled out in between
1843 * - thus the timestamp would be the same
1845 * But this is a bit hairy.
1847 * So instead, we have an explicit cgroup call to remain
1848 * within the time time source all along. We believe it
1849 * is cleaner and simpler to understand.
1851 if (is_cgroup_event(event
))
1852 perf_cgroup_set_shadow_time(event
, tstamp
);
1854 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1857 #define MAX_INTERRUPTS (~0ULL)
1859 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1860 static void perf_log_itrace_start(struct perf_event
*event
);
1863 event_sched_in(struct perf_event
*event
,
1864 struct perf_cpu_context
*cpuctx
,
1865 struct perf_event_context
*ctx
)
1867 u64 tstamp
= perf_event_time(event
);
1870 lockdep_assert_held(&ctx
->lock
);
1872 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1875 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1876 event
->oncpu
= smp_processor_id();
1879 * Unthrottle events, since we scheduled we might have missed several
1880 * ticks already, also for a heavily scheduling task there is little
1881 * guarantee it'll get a tick in a timely manner.
1883 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1884 perf_log_throttle(event
, 1);
1885 event
->hw
.interrupts
= 0;
1889 * The new state must be visible before we turn it on in the hardware:
1893 perf_pmu_disable(event
->pmu
);
1895 perf_set_shadow_time(event
, ctx
, tstamp
);
1897 perf_log_itrace_start(event
);
1899 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1900 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1906 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1908 if (!is_software_event(event
))
1909 cpuctx
->active_oncpu
++;
1910 if (!ctx
->nr_active
++)
1911 perf_event_ctx_activate(ctx
);
1912 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1915 if (event
->attr
.exclusive
)
1916 cpuctx
->exclusive
= 1;
1918 if (is_orphaned_child(event
))
1919 schedule_orphans_remove(ctx
);
1922 perf_pmu_enable(event
->pmu
);
1928 group_sched_in(struct perf_event
*group_event
,
1929 struct perf_cpu_context
*cpuctx
,
1930 struct perf_event_context
*ctx
)
1932 struct perf_event
*event
, *partial_group
= NULL
;
1933 struct pmu
*pmu
= ctx
->pmu
;
1934 u64 now
= ctx
->time
;
1935 bool simulate
= false;
1937 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1940 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
1942 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1943 pmu
->cancel_txn(pmu
);
1944 perf_mux_hrtimer_restart(cpuctx
);
1949 * Schedule in siblings as one group (if any):
1951 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1952 if (event_sched_in(event
, cpuctx
, ctx
)) {
1953 partial_group
= event
;
1958 if (!pmu
->commit_txn(pmu
))
1963 * Groups can be scheduled in as one unit only, so undo any
1964 * partial group before returning:
1965 * The events up to the failed event are scheduled out normally,
1966 * tstamp_stopped will be updated.
1968 * The failed events and the remaining siblings need to have
1969 * their timings updated as if they had gone thru event_sched_in()
1970 * and event_sched_out(). This is required to get consistent timings
1971 * across the group. This also takes care of the case where the group
1972 * could never be scheduled by ensuring tstamp_stopped is set to mark
1973 * the time the event was actually stopped, such that time delta
1974 * calculation in update_event_times() is correct.
1976 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1977 if (event
== partial_group
)
1981 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1982 event
->tstamp_stopped
= now
;
1984 event_sched_out(event
, cpuctx
, ctx
);
1987 event_sched_out(group_event
, cpuctx
, ctx
);
1989 pmu
->cancel_txn(pmu
);
1991 perf_mux_hrtimer_restart(cpuctx
);
1997 * Work out whether we can put this event group on the CPU now.
1999 static int group_can_go_on(struct perf_event
*event
,
2000 struct perf_cpu_context
*cpuctx
,
2004 * Groups consisting entirely of software events can always go on.
2006 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2009 * If an exclusive group is already on, no other hardware
2012 if (cpuctx
->exclusive
)
2015 * If this group is exclusive and there are already
2016 * events on the CPU, it can't go on.
2018 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2021 * Otherwise, try to add it if all previous groups were able
2027 static void add_event_to_ctx(struct perf_event
*event
,
2028 struct perf_event_context
*ctx
)
2030 u64 tstamp
= perf_event_time(event
);
2032 list_add_event(event
, ctx
);
2033 perf_group_attach(event
);
2034 event
->tstamp_enabled
= tstamp
;
2035 event
->tstamp_running
= tstamp
;
2036 event
->tstamp_stopped
= tstamp
;
2039 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2040 struct perf_event_context
*ctx
);
2042 ctx_sched_in(struct perf_event_context
*ctx
,
2043 struct perf_cpu_context
*cpuctx
,
2044 enum event_type_t event_type
,
2045 struct task_struct
*task
);
2047 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2048 struct perf_event_context
*ctx
,
2049 struct task_struct
*task
)
2051 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2053 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2054 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2056 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2059 static void ___perf_install_in_context(void *info
)
2061 struct perf_event
*event
= info
;
2062 struct perf_event_context
*ctx
= event
->ctx
;
2065 * Since the task isn't running, its safe to add the event, us holding
2066 * the ctx->lock ensures the task won't get scheduled in.
2068 add_event_to_ctx(event
, ctx
);
2071 static void ctx_resched(struct perf_cpu_context
*cpuctx
,
2072 struct perf_event_context
*task_ctx
)
2074 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2076 task_ctx_sched_out(cpuctx
, task_ctx
);
2077 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2078 perf_event_sched_in(cpuctx
, task_ctx
, current
);
2079 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2083 * Cross CPU call to install and enable a performance event
2085 * Must be called with ctx->mutex held
2087 static int __perf_install_in_context(void *info
)
2089 struct perf_event
*event
= info
;
2090 struct perf_event_context
*ctx
= event
->ctx
;
2091 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2092 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2093 struct task_struct
*task
= current
;
2095 perf_ctx_lock(cpuctx
, task_ctx
);
2096 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2099 * If there was an active task_ctx schedule it out.
2102 task_ctx_sched_out(cpuctx
, task_ctx
);
2105 * If the context we're installing events in is not the
2106 * active task_ctx, flip them.
2108 if (ctx
->task
&& task_ctx
!= ctx
) {
2110 raw_spin_unlock(&task_ctx
->lock
);
2111 raw_spin_lock(&ctx
->lock
);
2116 cpuctx
->task_ctx
= task_ctx
;
2117 task
= task_ctx
->task
;
2120 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2122 update_context_time(ctx
);
2124 * update cgrp time only if current cgrp
2125 * matches event->cgrp. Must be done before
2126 * calling add_event_to_ctx()
2128 update_cgrp_time_from_event(event
);
2130 add_event_to_ctx(event
, ctx
);
2133 * Schedule everything back in
2135 perf_event_sched_in(cpuctx
, task_ctx
, task
);
2137 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2138 perf_ctx_unlock(cpuctx
, task_ctx
);
2144 * Attach a performance event to a context
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
);
2191 struct perf_event_context
*task_ctx
= cpuctx
->task_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 perf_ctx_lock(cpuctx
, task_ctx
);
2206 WARN_ON_ONCE(&cpuctx
->ctx
!= ctx
&& task_ctx
!= ctx
);
2207 update_context_time(ctx
);
2209 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2213 * set current task's cgroup time reference point
2215 perf_cgroup_set_timestamp(current
, ctx
);
2217 __perf_event_mark_enabled(event
);
2219 if (!event_filter_match(event
)) {
2220 if (is_cgroup_event(event
))
2221 perf_cgroup_defer_enabled(event
);
2226 * If the event is in a group and isn't the group leader,
2227 * then don't put it on unless the group is on.
2229 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2232 ctx_resched(cpuctx
, task_ctx
);
2235 perf_ctx_unlock(cpuctx
, task_ctx
);
2240 void ___perf_event_enable(void *info
)
2242 __perf_event_mark_enabled((struct perf_event
*)info
);
2248 * If event->ctx is a cloned context, callers must make sure that
2249 * every task struct that event->ctx->task could possibly point to
2250 * remains valid. This condition is satisfied when called through
2251 * perf_event_for_each_child or perf_event_for_each as described
2252 * for perf_event_disable.
2254 static void _perf_event_enable(struct perf_event
*event
)
2256 struct perf_event_context
*ctx
= event
->ctx
;
2258 raw_spin_lock_irq(&ctx
->lock
);
2259 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
2260 raw_spin_unlock_irq(&ctx
->lock
);
2265 * If the event is in error state, clear that first.
2267 * That way, if we see the event in error state below, we know that it
2268 * has gone back into error state, as distinct from the task having
2269 * been scheduled away before the cross-call arrived.
2271 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2272 event
->state
= PERF_EVENT_STATE_OFF
;
2273 raw_spin_unlock_irq(&ctx
->lock
);
2275 event_function_call(event
, __perf_event_enable
,
2276 ___perf_event_enable
, event
);
2280 * See perf_event_disable();
2282 void perf_event_enable(struct perf_event
*event
)
2284 struct perf_event_context
*ctx
;
2286 ctx
= perf_event_ctx_lock(event
);
2287 _perf_event_enable(event
);
2288 perf_event_ctx_unlock(event
, ctx
);
2290 EXPORT_SYMBOL_GPL(perf_event_enable
);
2292 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2295 * not supported on inherited events
2297 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2300 atomic_add(refresh
, &event
->event_limit
);
2301 _perf_event_enable(event
);
2307 * See perf_event_disable()
2309 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2311 struct perf_event_context
*ctx
;
2314 ctx
= perf_event_ctx_lock(event
);
2315 ret
= _perf_event_refresh(event
, refresh
);
2316 perf_event_ctx_unlock(event
, ctx
);
2320 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2322 static void ctx_sched_out(struct perf_event_context
*ctx
,
2323 struct perf_cpu_context
*cpuctx
,
2324 enum event_type_t event_type
)
2326 int is_active
= ctx
->is_active
;
2327 struct perf_event
*event
;
2329 lockdep_assert_held(&ctx
->lock
);
2331 ctx
->is_active
&= ~event_type
;
2333 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2334 if (!ctx
->is_active
)
2335 cpuctx
->task_ctx
= NULL
;
2338 if (likely(!ctx
->nr_events
))
2341 update_context_time(ctx
);
2342 update_cgrp_time_from_cpuctx(cpuctx
);
2343 if (!ctx
->nr_active
)
2346 perf_pmu_disable(ctx
->pmu
);
2347 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2348 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2349 group_sched_out(event
, cpuctx
, ctx
);
2352 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2353 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2354 group_sched_out(event
, cpuctx
, ctx
);
2356 perf_pmu_enable(ctx
->pmu
);
2360 * Test whether two contexts are equivalent, i.e. whether they have both been
2361 * cloned from the same version of the same context.
2363 * Equivalence is measured using a generation number in the context that is
2364 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2365 * and list_del_event().
2367 static int context_equiv(struct perf_event_context
*ctx1
,
2368 struct perf_event_context
*ctx2
)
2370 lockdep_assert_held(&ctx1
->lock
);
2371 lockdep_assert_held(&ctx2
->lock
);
2373 /* Pinning disables the swap optimization */
2374 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2377 /* If ctx1 is the parent of ctx2 */
2378 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2381 /* If ctx2 is the parent of ctx1 */
2382 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2386 * If ctx1 and ctx2 have the same parent; we flatten the parent
2387 * hierarchy, see perf_event_init_context().
2389 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2390 ctx1
->parent_gen
== ctx2
->parent_gen
)
2397 static void __perf_event_sync_stat(struct perf_event
*event
,
2398 struct perf_event
*next_event
)
2402 if (!event
->attr
.inherit_stat
)
2406 * Update the event value, we cannot use perf_event_read()
2407 * because we're in the middle of a context switch and have IRQs
2408 * disabled, which upsets smp_call_function_single(), however
2409 * we know the event must be on the current CPU, therefore we
2410 * don't need to use it.
2412 switch (event
->state
) {
2413 case PERF_EVENT_STATE_ACTIVE
:
2414 event
->pmu
->read(event
);
2417 case PERF_EVENT_STATE_INACTIVE
:
2418 update_event_times(event
);
2426 * In order to keep per-task stats reliable we need to flip the event
2427 * values when we flip the contexts.
2429 value
= local64_read(&next_event
->count
);
2430 value
= local64_xchg(&event
->count
, value
);
2431 local64_set(&next_event
->count
, value
);
2433 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2434 swap(event
->total_time_running
, next_event
->total_time_running
);
2437 * Since we swizzled the values, update the user visible data too.
2439 perf_event_update_userpage(event
);
2440 perf_event_update_userpage(next_event
);
2443 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2444 struct perf_event_context
*next_ctx
)
2446 struct perf_event
*event
, *next_event
;
2451 update_context_time(ctx
);
2453 event
= list_first_entry(&ctx
->event_list
,
2454 struct perf_event
, event_entry
);
2456 next_event
= list_first_entry(&next_ctx
->event_list
,
2457 struct perf_event
, event_entry
);
2459 while (&event
->event_entry
!= &ctx
->event_list
&&
2460 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2462 __perf_event_sync_stat(event
, next_event
);
2464 event
= list_next_entry(event
, event_entry
);
2465 next_event
= list_next_entry(next_event
, event_entry
);
2469 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2470 struct task_struct
*next
)
2472 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2473 struct perf_event_context
*next_ctx
;
2474 struct perf_event_context
*parent
, *next_parent
;
2475 struct perf_cpu_context
*cpuctx
;
2481 cpuctx
= __get_cpu_context(ctx
);
2482 if (!cpuctx
->task_ctx
)
2486 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2490 parent
= rcu_dereference(ctx
->parent_ctx
);
2491 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2493 /* If neither context have a parent context; they cannot be clones. */
2494 if (!parent
&& !next_parent
)
2497 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2499 * Looks like the two contexts are clones, so we might be
2500 * able to optimize the context switch. We lock both
2501 * contexts and check that they are clones under the
2502 * lock (including re-checking that neither has been
2503 * uncloned in the meantime). It doesn't matter which
2504 * order we take the locks because no other cpu could
2505 * be trying to lock both of these tasks.
2507 raw_spin_lock(&ctx
->lock
);
2508 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2509 if (context_equiv(ctx
, next_ctx
)) {
2511 * XXX do we need a memory barrier of sorts
2512 * wrt to rcu_dereference() of perf_event_ctxp
2514 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2515 next
->perf_event_ctxp
[ctxn
] = ctx
;
2517 next_ctx
->task
= task
;
2519 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2523 perf_event_sync_stat(ctx
, next_ctx
);
2525 raw_spin_unlock(&next_ctx
->lock
);
2526 raw_spin_unlock(&ctx
->lock
);
2532 raw_spin_lock(&ctx
->lock
);
2533 task_ctx_sched_out(cpuctx
, ctx
);
2534 raw_spin_unlock(&ctx
->lock
);
2538 void perf_sched_cb_dec(struct pmu
*pmu
)
2540 this_cpu_dec(perf_sched_cb_usages
);
2543 void perf_sched_cb_inc(struct pmu
*pmu
)
2545 this_cpu_inc(perf_sched_cb_usages
);
2549 * This function provides the context switch callback to the lower code
2550 * layer. It is invoked ONLY when the context switch callback is enabled.
2552 static void perf_pmu_sched_task(struct task_struct
*prev
,
2553 struct task_struct
*next
,
2556 struct perf_cpu_context
*cpuctx
;
2558 unsigned long flags
;
2563 local_irq_save(flags
);
2567 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2568 if (pmu
->sched_task
) {
2569 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2571 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2573 perf_pmu_disable(pmu
);
2575 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2577 perf_pmu_enable(pmu
);
2579 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2585 local_irq_restore(flags
);
2588 static void perf_event_switch(struct task_struct
*task
,
2589 struct task_struct
*next_prev
, bool sched_in
);
2591 #define for_each_task_context_nr(ctxn) \
2592 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2595 * Called from scheduler to remove the events of the current task,
2596 * with interrupts disabled.
2598 * We stop each event and update the event value in event->count.
2600 * This does not protect us against NMI, but disable()
2601 * sets the disabled bit in the control field of event _before_
2602 * accessing the event control register. If a NMI hits, then it will
2603 * not restart the event.
2605 void __perf_event_task_sched_out(struct task_struct
*task
,
2606 struct task_struct
*next
)
2610 if (__this_cpu_read(perf_sched_cb_usages
))
2611 perf_pmu_sched_task(task
, next
, false);
2613 if (atomic_read(&nr_switch_events
))
2614 perf_event_switch(task
, next
, false);
2616 for_each_task_context_nr(ctxn
)
2617 perf_event_context_sched_out(task
, ctxn
, next
);
2620 * if cgroup events exist on this CPU, then we need
2621 * to check if we have to switch out PMU state.
2622 * cgroup event are system-wide mode only
2624 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2625 perf_cgroup_sched_out(task
, next
);
2628 static void task_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2629 struct perf_event_context
*ctx
)
2631 if (!cpuctx
->task_ctx
)
2634 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2637 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2641 * Called with IRQs disabled
2643 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2644 enum event_type_t event_type
)
2646 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2650 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2651 struct perf_cpu_context
*cpuctx
)
2653 struct perf_event
*event
;
2655 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2656 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2658 if (!event_filter_match(event
))
2661 /* may need to reset tstamp_enabled */
2662 if (is_cgroup_event(event
))
2663 perf_cgroup_mark_enabled(event
, ctx
);
2665 if (group_can_go_on(event
, cpuctx
, 1))
2666 group_sched_in(event
, cpuctx
, ctx
);
2669 * If this pinned group hasn't been scheduled,
2670 * put it in error state.
2672 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2673 update_group_times(event
);
2674 event
->state
= PERF_EVENT_STATE_ERROR
;
2680 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2681 struct perf_cpu_context
*cpuctx
)
2683 struct perf_event
*event
;
2686 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2687 /* Ignore events in OFF or ERROR state */
2688 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2691 * Listen to the 'cpu' scheduling filter constraint
2694 if (!event_filter_match(event
))
2697 /* may need to reset tstamp_enabled */
2698 if (is_cgroup_event(event
))
2699 perf_cgroup_mark_enabled(event
, ctx
);
2701 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2702 if (group_sched_in(event
, cpuctx
, ctx
))
2709 ctx_sched_in(struct perf_event_context
*ctx
,
2710 struct perf_cpu_context
*cpuctx
,
2711 enum event_type_t event_type
,
2712 struct task_struct
*task
)
2714 int is_active
= ctx
->is_active
;
2717 lockdep_assert_held(&ctx
->lock
);
2719 ctx
->is_active
|= event_type
;
2722 cpuctx
->task_ctx
= ctx
;
2724 WARN_ON_ONCE(cpuctx
->task_ctx
!= ctx
);
2727 if (likely(!ctx
->nr_events
))
2731 ctx
->timestamp
= now
;
2732 perf_cgroup_set_timestamp(task
, ctx
);
2734 * First go through the list and put on any pinned groups
2735 * in order to give them the best chance of going on.
2737 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2738 ctx_pinned_sched_in(ctx
, cpuctx
);
2740 /* Then walk through the lower prio flexible groups */
2741 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2742 ctx_flexible_sched_in(ctx
, cpuctx
);
2745 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2746 enum event_type_t event_type
,
2747 struct task_struct
*task
)
2749 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2751 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2754 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2755 struct task_struct
*task
)
2757 struct perf_cpu_context
*cpuctx
;
2759 cpuctx
= __get_cpu_context(ctx
);
2760 if (cpuctx
->task_ctx
== ctx
)
2763 perf_ctx_lock(cpuctx
, ctx
);
2764 perf_pmu_disable(ctx
->pmu
);
2766 * We want to keep the following priority order:
2767 * cpu pinned (that don't need to move), task pinned,
2768 * cpu flexible, task flexible.
2770 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2771 perf_event_sched_in(cpuctx
, ctx
, task
);
2772 perf_pmu_enable(ctx
->pmu
);
2773 perf_ctx_unlock(cpuctx
, ctx
);
2777 * Called from scheduler to add the events of the current task
2778 * with interrupts disabled.
2780 * We restore the event value and then enable it.
2782 * This does not protect us against NMI, but enable()
2783 * sets the enabled bit in the control field of event _before_
2784 * accessing the event control register. If a NMI hits, then it will
2785 * keep the event running.
2787 void __perf_event_task_sched_in(struct task_struct
*prev
,
2788 struct task_struct
*task
)
2790 struct perf_event_context
*ctx
;
2794 * If cgroup events exist on this CPU, then we need to check if we have
2795 * to switch in PMU state; cgroup event are system-wide mode only.
2797 * Since cgroup events are CPU events, we must schedule these in before
2798 * we schedule in the task events.
2800 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2801 perf_cgroup_sched_in(prev
, task
);
2803 for_each_task_context_nr(ctxn
) {
2804 ctx
= task
->perf_event_ctxp
[ctxn
];
2808 perf_event_context_sched_in(ctx
, task
);
2811 if (atomic_read(&nr_switch_events
))
2812 perf_event_switch(task
, prev
, true);
2814 if (__this_cpu_read(perf_sched_cb_usages
))
2815 perf_pmu_sched_task(prev
, task
, true);
2818 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2820 u64 frequency
= event
->attr
.sample_freq
;
2821 u64 sec
= NSEC_PER_SEC
;
2822 u64 divisor
, dividend
;
2824 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2826 count_fls
= fls64(count
);
2827 nsec_fls
= fls64(nsec
);
2828 frequency_fls
= fls64(frequency
);
2832 * We got @count in @nsec, with a target of sample_freq HZ
2833 * the target period becomes:
2836 * period = -------------------
2837 * @nsec * sample_freq
2842 * Reduce accuracy by one bit such that @a and @b converge
2843 * to a similar magnitude.
2845 #define REDUCE_FLS(a, b) \
2847 if (a##_fls > b##_fls) { \
2857 * Reduce accuracy until either term fits in a u64, then proceed with
2858 * the other, so that finally we can do a u64/u64 division.
2860 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2861 REDUCE_FLS(nsec
, frequency
);
2862 REDUCE_FLS(sec
, count
);
2865 if (count_fls
+ sec_fls
> 64) {
2866 divisor
= nsec
* frequency
;
2868 while (count_fls
+ sec_fls
> 64) {
2869 REDUCE_FLS(count
, sec
);
2873 dividend
= count
* sec
;
2875 dividend
= count
* sec
;
2877 while (nsec_fls
+ frequency_fls
> 64) {
2878 REDUCE_FLS(nsec
, frequency
);
2882 divisor
= nsec
* frequency
;
2888 return div64_u64(dividend
, divisor
);
2891 static DEFINE_PER_CPU(int, perf_throttled_count
);
2892 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2894 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2896 struct hw_perf_event
*hwc
= &event
->hw
;
2897 s64 period
, sample_period
;
2900 period
= perf_calculate_period(event
, nsec
, count
);
2902 delta
= (s64
)(period
- hwc
->sample_period
);
2903 delta
= (delta
+ 7) / 8; /* low pass filter */
2905 sample_period
= hwc
->sample_period
+ delta
;
2910 hwc
->sample_period
= sample_period
;
2912 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2914 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2916 local64_set(&hwc
->period_left
, 0);
2919 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2924 * combine freq adjustment with unthrottling to avoid two passes over the
2925 * events. At the same time, make sure, having freq events does not change
2926 * the rate of unthrottling as that would introduce bias.
2928 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2931 struct perf_event
*event
;
2932 struct hw_perf_event
*hwc
;
2933 u64 now
, period
= TICK_NSEC
;
2937 * only need to iterate over all events iff:
2938 * - context have events in frequency mode (needs freq adjust)
2939 * - there are events to unthrottle on this cpu
2941 if (!(ctx
->nr_freq
|| needs_unthr
))
2944 raw_spin_lock(&ctx
->lock
);
2945 perf_pmu_disable(ctx
->pmu
);
2947 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2948 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2951 if (!event_filter_match(event
))
2954 perf_pmu_disable(event
->pmu
);
2958 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
2959 hwc
->interrupts
= 0;
2960 perf_log_throttle(event
, 1);
2961 event
->pmu
->start(event
, 0);
2964 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2968 * stop the event and update event->count
2970 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2972 now
= local64_read(&event
->count
);
2973 delta
= now
- hwc
->freq_count_stamp
;
2974 hwc
->freq_count_stamp
= now
;
2978 * reload only if value has changed
2979 * we have stopped the event so tell that
2980 * to perf_adjust_period() to avoid stopping it
2984 perf_adjust_period(event
, period
, delta
, false);
2986 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
2988 perf_pmu_enable(event
->pmu
);
2991 perf_pmu_enable(ctx
->pmu
);
2992 raw_spin_unlock(&ctx
->lock
);
2996 * Round-robin a context's events:
2998 static void rotate_ctx(struct perf_event_context
*ctx
)
3001 * Rotate the first entry last of non-pinned groups. Rotation might be
3002 * disabled by the inheritance code.
3004 if (!ctx
->rotate_disable
)
3005 list_rotate_left(&ctx
->flexible_groups
);
3008 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3010 struct perf_event_context
*ctx
= NULL
;
3013 if (cpuctx
->ctx
.nr_events
) {
3014 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3018 ctx
= cpuctx
->task_ctx
;
3019 if (ctx
&& ctx
->nr_events
) {
3020 if (ctx
->nr_events
!= ctx
->nr_active
)
3027 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3028 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3030 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3032 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3034 rotate_ctx(&cpuctx
->ctx
);
3038 perf_event_sched_in(cpuctx
, ctx
, current
);
3040 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3041 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3047 #ifdef CONFIG_NO_HZ_FULL
3048 bool perf_event_can_stop_tick(void)
3050 if (atomic_read(&nr_freq_events
) ||
3051 __this_cpu_read(perf_throttled_count
))
3058 void perf_event_task_tick(void)
3060 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3061 struct perf_event_context
*ctx
, *tmp
;
3064 WARN_ON(!irqs_disabled());
3066 __this_cpu_inc(perf_throttled_seq
);
3067 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3069 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3070 perf_adjust_freq_unthr_context(ctx
, throttled
);
3073 static int event_enable_on_exec(struct perf_event
*event
,
3074 struct perf_event_context
*ctx
)
3076 if (!event
->attr
.enable_on_exec
)
3079 event
->attr
.enable_on_exec
= 0;
3080 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3083 __perf_event_mark_enabled(event
);
3089 * Enable all of a task's events that have been marked enable-on-exec.
3090 * This expects task == current.
3092 static void perf_event_enable_on_exec(int ctxn
)
3094 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3095 struct perf_cpu_context
*cpuctx
;
3096 struct perf_event
*event
;
3097 unsigned long flags
;
3100 local_irq_save(flags
);
3101 ctx
= current
->perf_event_ctxp
[ctxn
];
3102 if (!ctx
|| !ctx
->nr_events
)
3105 cpuctx
= __get_cpu_context(ctx
);
3106 perf_ctx_lock(cpuctx
, ctx
);
3107 list_for_each_entry(event
, &ctx
->event_list
, event_entry
)
3108 enabled
|= event_enable_on_exec(event
, ctx
);
3111 * Unclone and reschedule this context if we enabled any event.
3114 clone_ctx
= unclone_ctx(ctx
);
3115 ctx_resched(cpuctx
, ctx
);
3117 perf_ctx_unlock(cpuctx
, ctx
);
3120 local_irq_restore(flags
);
3126 void perf_event_exec(void)
3131 for_each_task_context_nr(ctxn
)
3132 perf_event_enable_on_exec(ctxn
);
3136 struct perf_read_data
{
3137 struct perf_event
*event
;
3143 * Cross CPU call to read the hardware event
3145 static void __perf_event_read(void *info
)
3147 struct perf_read_data
*data
= info
;
3148 struct perf_event
*sub
, *event
= data
->event
;
3149 struct perf_event_context
*ctx
= event
->ctx
;
3150 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3151 struct pmu
*pmu
= event
->pmu
;
3154 * If this is a task context, we need to check whether it is
3155 * the current task context of this cpu. If not it has been
3156 * scheduled out before the smp call arrived. In that case
3157 * event->count would have been updated to a recent sample
3158 * when the event was scheduled out.
3160 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3163 raw_spin_lock(&ctx
->lock
);
3164 if (ctx
->is_active
) {
3165 update_context_time(ctx
);
3166 update_cgrp_time_from_event(event
);
3169 update_event_times(event
);
3170 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3179 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3183 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3184 update_event_times(sub
);
3185 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3187 * Use sibling's PMU rather than @event's since
3188 * sibling could be on different (eg: software) PMU.
3190 sub
->pmu
->read(sub
);
3194 data
->ret
= pmu
->commit_txn(pmu
);
3197 raw_spin_unlock(&ctx
->lock
);
3200 static inline u64
perf_event_count(struct perf_event
*event
)
3202 if (event
->pmu
->count
)
3203 return event
->pmu
->count(event
);
3205 return __perf_event_count(event
);
3209 * NMI-safe method to read a local event, that is an event that
3211 * - either for the current task, or for this CPU
3212 * - does not have inherit set, for inherited task events
3213 * will not be local and we cannot read them atomically
3214 * - must not have a pmu::count method
3216 u64
perf_event_read_local(struct perf_event
*event
)
3218 unsigned long flags
;
3222 * Disabling interrupts avoids all counter scheduling (context
3223 * switches, timer based rotation and IPIs).
3225 local_irq_save(flags
);
3227 /* If this is a per-task event, it must be for current */
3228 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3229 event
->hw
.target
!= current
);
3231 /* If this is a per-CPU event, it must be for this CPU */
3232 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3233 event
->cpu
!= smp_processor_id());
3236 * It must not be an event with inherit set, we cannot read
3237 * all child counters from atomic context.
3239 WARN_ON_ONCE(event
->attr
.inherit
);
3242 * It must not have a pmu::count method, those are not
3245 WARN_ON_ONCE(event
->pmu
->count
);
3248 * If the event is currently on this CPU, its either a per-task event,
3249 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3252 if (event
->oncpu
== smp_processor_id())
3253 event
->pmu
->read(event
);
3255 val
= local64_read(&event
->count
);
3256 local_irq_restore(flags
);
3261 static int perf_event_read(struct perf_event
*event
, bool group
)
3266 * If event is enabled and currently active on a CPU, update the
3267 * value in the event structure:
3269 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3270 struct perf_read_data data
= {
3275 smp_call_function_single(event
->oncpu
,
3276 __perf_event_read
, &data
, 1);
3278 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3279 struct perf_event_context
*ctx
= event
->ctx
;
3280 unsigned long flags
;
3282 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3284 * may read while context is not active
3285 * (e.g., thread is blocked), in that case
3286 * we cannot update context time
3288 if (ctx
->is_active
) {
3289 update_context_time(ctx
);
3290 update_cgrp_time_from_event(event
);
3293 update_group_times(event
);
3295 update_event_times(event
);
3296 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3303 * Initialize the perf_event context in a task_struct:
3305 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3307 raw_spin_lock_init(&ctx
->lock
);
3308 mutex_init(&ctx
->mutex
);
3309 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3310 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3311 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3312 INIT_LIST_HEAD(&ctx
->event_list
);
3313 atomic_set(&ctx
->refcount
, 1);
3314 INIT_DELAYED_WORK(&ctx
->orphans_remove
, orphans_remove_work
);
3317 static struct perf_event_context
*
3318 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3320 struct perf_event_context
*ctx
;
3322 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3326 __perf_event_init_context(ctx
);
3329 get_task_struct(task
);
3336 static struct task_struct
*
3337 find_lively_task_by_vpid(pid_t vpid
)
3339 struct task_struct
*task
;
3346 task
= find_task_by_vpid(vpid
);
3348 get_task_struct(task
);
3352 return ERR_PTR(-ESRCH
);
3354 /* Reuse ptrace permission checks for now. */
3356 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3361 put_task_struct(task
);
3362 return ERR_PTR(err
);
3367 * Returns a matching context with refcount and pincount.
3369 static struct perf_event_context
*
3370 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3371 struct perf_event
*event
)
3373 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3374 struct perf_cpu_context
*cpuctx
;
3375 void *task_ctx_data
= NULL
;
3376 unsigned long flags
;
3378 int cpu
= event
->cpu
;
3381 /* Must be root to operate on a CPU event: */
3382 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3383 return ERR_PTR(-EACCES
);
3386 * We could be clever and allow to attach a event to an
3387 * offline CPU and activate it when the CPU comes up, but
3390 if (!cpu_online(cpu
))
3391 return ERR_PTR(-ENODEV
);
3393 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3402 ctxn
= pmu
->task_ctx_nr
;
3406 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3407 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3408 if (!task_ctx_data
) {
3415 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3417 clone_ctx
= unclone_ctx(ctx
);
3420 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3421 ctx
->task_ctx_data
= task_ctx_data
;
3422 task_ctx_data
= NULL
;
3424 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3429 ctx
= alloc_perf_context(pmu
, task
);
3434 if (task_ctx_data
) {
3435 ctx
->task_ctx_data
= task_ctx_data
;
3436 task_ctx_data
= NULL
;
3440 mutex_lock(&task
->perf_event_mutex
);
3442 * If it has already passed perf_event_exit_task().
3443 * we must see PF_EXITING, it takes this mutex too.
3445 if (task
->flags
& PF_EXITING
)
3447 else if (task
->perf_event_ctxp
[ctxn
])
3452 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3454 mutex_unlock(&task
->perf_event_mutex
);
3456 if (unlikely(err
)) {
3465 kfree(task_ctx_data
);
3469 kfree(task_ctx_data
);
3470 return ERR_PTR(err
);
3473 static void perf_event_free_filter(struct perf_event
*event
);
3474 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3476 static void free_event_rcu(struct rcu_head
*head
)
3478 struct perf_event
*event
;
3480 event
= container_of(head
, struct perf_event
, rcu_head
);
3482 put_pid_ns(event
->ns
);
3483 perf_event_free_filter(event
);
3487 static void ring_buffer_attach(struct perf_event
*event
,
3488 struct ring_buffer
*rb
);
3490 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3495 if (is_cgroup_event(event
))
3496 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3499 static void unaccount_event(struct perf_event
*event
)
3506 if (event
->attach_state
& PERF_ATTACH_TASK
)
3508 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3509 atomic_dec(&nr_mmap_events
);
3510 if (event
->attr
.comm
)
3511 atomic_dec(&nr_comm_events
);
3512 if (event
->attr
.task
)
3513 atomic_dec(&nr_task_events
);
3514 if (event
->attr
.freq
)
3515 atomic_dec(&nr_freq_events
);
3516 if (event
->attr
.context_switch
) {
3518 atomic_dec(&nr_switch_events
);
3520 if (is_cgroup_event(event
))
3522 if (has_branch_stack(event
))
3526 static_key_slow_dec_deferred(&perf_sched_events
);
3528 unaccount_event_cpu(event
, event
->cpu
);
3532 * The following implement mutual exclusion of events on "exclusive" pmus
3533 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3534 * at a time, so we disallow creating events that might conflict, namely:
3536 * 1) cpu-wide events in the presence of per-task events,
3537 * 2) per-task events in the presence of cpu-wide events,
3538 * 3) two matching events on the same context.
3540 * The former two cases are handled in the allocation path (perf_event_alloc(),
3541 * __free_event()), the latter -- before the first perf_install_in_context().
3543 static int exclusive_event_init(struct perf_event
*event
)
3545 struct pmu
*pmu
= event
->pmu
;
3547 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3551 * Prevent co-existence of per-task and cpu-wide events on the
3552 * same exclusive pmu.
3554 * Negative pmu::exclusive_cnt means there are cpu-wide
3555 * events on this "exclusive" pmu, positive means there are
3558 * Since this is called in perf_event_alloc() path, event::ctx
3559 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3560 * to mean "per-task event", because unlike other attach states it
3561 * never gets cleared.
3563 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3564 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3567 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3574 static void exclusive_event_destroy(struct perf_event
*event
)
3576 struct pmu
*pmu
= event
->pmu
;
3578 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3581 /* see comment in exclusive_event_init() */
3582 if (event
->attach_state
& PERF_ATTACH_TASK
)
3583 atomic_dec(&pmu
->exclusive_cnt
);
3585 atomic_inc(&pmu
->exclusive_cnt
);
3588 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3590 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3591 (e1
->cpu
== e2
->cpu
||
3598 /* Called under the same ctx::mutex as perf_install_in_context() */
3599 static bool exclusive_event_installable(struct perf_event
*event
,
3600 struct perf_event_context
*ctx
)
3602 struct perf_event
*iter_event
;
3603 struct pmu
*pmu
= event
->pmu
;
3605 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3608 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3609 if (exclusive_event_match(iter_event
, event
))
3616 static void __free_event(struct perf_event
*event
)
3618 if (!event
->parent
) {
3619 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3620 put_callchain_buffers();
3623 perf_event_free_bpf_prog(event
);
3626 event
->destroy(event
);
3629 put_ctx(event
->ctx
);
3632 exclusive_event_destroy(event
);
3633 module_put(event
->pmu
->module
);
3636 call_rcu(&event
->rcu_head
, free_event_rcu
);
3639 static void _free_event(struct perf_event
*event
)
3641 irq_work_sync(&event
->pending
);
3643 unaccount_event(event
);
3647 * Can happen when we close an event with re-directed output.
3649 * Since we have a 0 refcount, perf_mmap_close() will skip
3650 * over us; possibly making our ring_buffer_put() the last.
3652 mutex_lock(&event
->mmap_mutex
);
3653 ring_buffer_attach(event
, NULL
);
3654 mutex_unlock(&event
->mmap_mutex
);
3657 if (is_cgroup_event(event
))
3658 perf_detach_cgroup(event
);
3660 __free_event(event
);
3664 * Used to free events which have a known refcount of 1, such as in error paths
3665 * where the event isn't exposed yet and inherited events.
3667 static void free_event(struct perf_event
*event
)
3669 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3670 "unexpected event refcount: %ld; ptr=%p\n",
3671 atomic_long_read(&event
->refcount
), event
)) {
3672 /* leak to avoid use-after-free */
3680 * Remove user event from the owner task.
3682 static void perf_remove_from_owner(struct perf_event
*event
)
3684 struct task_struct
*owner
;
3687 owner
= ACCESS_ONCE(event
->owner
);
3689 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3690 * !owner it means the list deletion is complete and we can indeed
3691 * free this event, otherwise we need to serialize on
3692 * owner->perf_event_mutex.
3694 smp_read_barrier_depends();
3697 * Since delayed_put_task_struct() also drops the last
3698 * task reference we can safely take a new reference
3699 * while holding the rcu_read_lock().
3701 get_task_struct(owner
);
3707 * If we're here through perf_event_exit_task() we're already
3708 * holding ctx->mutex which would be an inversion wrt. the
3709 * normal lock order.
3711 * However we can safely take this lock because its the child
3714 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3717 * We have to re-check the event->owner field, if it is cleared
3718 * we raced with perf_event_exit_task(), acquiring the mutex
3719 * ensured they're done, and we can proceed with freeing the
3723 list_del_init(&event
->owner_entry
);
3724 mutex_unlock(&owner
->perf_event_mutex
);
3725 put_task_struct(owner
);
3729 static void put_event(struct perf_event
*event
)
3731 struct perf_event_context
*ctx
;
3733 if (!atomic_long_dec_and_test(&event
->refcount
))
3736 if (!is_kernel_event(event
))
3737 perf_remove_from_owner(event
);
3740 * There are two ways this annotation is useful:
3742 * 1) there is a lock recursion from perf_event_exit_task
3743 * see the comment there.
3745 * 2) there is a lock-inversion with mmap_sem through
3746 * perf_read_group(), which takes faults while
3747 * holding ctx->mutex, however this is called after
3748 * the last filedesc died, so there is no possibility
3749 * to trigger the AB-BA case.
3751 ctx
= perf_event_ctx_lock_nested(event
, SINGLE_DEPTH_NESTING
);
3752 WARN_ON_ONCE(ctx
->parent_ctx
);
3753 perf_remove_from_context(event
, true);
3754 perf_event_ctx_unlock(event
, ctx
);
3759 int perf_event_release_kernel(struct perf_event
*event
)
3764 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3767 * Called when the last reference to the file is gone.
3769 static int perf_release(struct inode
*inode
, struct file
*file
)
3771 put_event(file
->private_data
);
3776 * Remove all orphanes events from the context.
3778 static void orphans_remove_work(struct work_struct
*work
)
3780 struct perf_event_context
*ctx
;
3781 struct perf_event
*event
, *tmp
;
3783 ctx
= container_of(work
, struct perf_event_context
,
3784 orphans_remove
.work
);
3786 mutex_lock(&ctx
->mutex
);
3787 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
) {
3788 struct perf_event
*parent_event
= event
->parent
;
3790 if (!is_orphaned_child(event
))
3793 perf_remove_from_context(event
, true);
3795 mutex_lock(&parent_event
->child_mutex
);
3796 list_del_init(&event
->child_list
);
3797 mutex_unlock(&parent_event
->child_mutex
);
3800 put_event(parent_event
);
3803 raw_spin_lock_irq(&ctx
->lock
);
3804 ctx
->orphans_remove_sched
= false;
3805 raw_spin_unlock_irq(&ctx
->lock
);
3806 mutex_unlock(&ctx
->mutex
);
3811 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3813 struct perf_event
*child
;
3819 mutex_lock(&event
->child_mutex
);
3821 (void)perf_event_read(event
, false);
3822 total
+= perf_event_count(event
);
3824 *enabled
+= event
->total_time_enabled
+
3825 atomic64_read(&event
->child_total_time_enabled
);
3826 *running
+= event
->total_time_running
+
3827 atomic64_read(&event
->child_total_time_running
);
3829 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3830 (void)perf_event_read(child
, false);
3831 total
+= perf_event_count(child
);
3832 *enabled
+= child
->total_time_enabled
;
3833 *running
+= child
->total_time_running
;
3835 mutex_unlock(&event
->child_mutex
);
3839 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3841 static int __perf_read_group_add(struct perf_event
*leader
,
3842 u64 read_format
, u64
*values
)
3844 struct perf_event
*sub
;
3845 int n
= 1; /* skip @nr */
3848 ret
= perf_event_read(leader
, true);
3853 * Since we co-schedule groups, {enabled,running} times of siblings
3854 * will be identical to those of the leader, so we only publish one
3857 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3858 values
[n
++] += leader
->total_time_enabled
+
3859 atomic64_read(&leader
->child_total_time_enabled
);
3862 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3863 values
[n
++] += leader
->total_time_running
+
3864 atomic64_read(&leader
->child_total_time_running
);
3868 * Write {count,id} tuples for every sibling.
3870 values
[n
++] += perf_event_count(leader
);
3871 if (read_format
& PERF_FORMAT_ID
)
3872 values
[n
++] = primary_event_id(leader
);
3874 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3875 values
[n
++] += perf_event_count(sub
);
3876 if (read_format
& PERF_FORMAT_ID
)
3877 values
[n
++] = primary_event_id(sub
);
3883 static int perf_read_group(struct perf_event
*event
,
3884 u64 read_format
, char __user
*buf
)
3886 struct perf_event
*leader
= event
->group_leader
, *child
;
3887 struct perf_event_context
*ctx
= leader
->ctx
;
3891 lockdep_assert_held(&ctx
->mutex
);
3893 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
3897 values
[0] = 1 + leader
->nr_siblings
;
3900 * By locking the child_mutex of the leader we effectively
3901 * lock the child list of all siblings.. XXX explain how.
3903 mutex_lock(&leader
->child_mutex
);
3905 ret
= __perf_read_group_add(leader
, read_format
, values
);
3909 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
3910 ret
= __perf_read_group_add(child
, read_format
, values
);
3915 mutex_unlock(&leader
->child_mutex
);
3917 ret
= event
->read_size
;
3918 if (copy_to_user(buf
, values
, event
->read_size
))
3923 mutex_unlock(&leader
->child_mutex
);
3929 static int perf_read_one(struct perf_event
*event
,
3930 u64 read_format
, char __user
*buf
)
3932 u64 enabled
, running
;
3936 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3937 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3938 values
[n
++] = enabled
;
3939 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3940 values
[n
++] = running
;
3941 if (read_format
& PERF_FORMAT_ID
)
3942 values
[n
++] = primary_event_id(event
);
3944 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3947 return n
* sizeof(u64
);
3950 static bool is_event_hup(struct perf_event
*event
)
3954 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
3957 mutex_lock(&event
->child_mutex
);
3958 no_children
= list_empty(&event
->child_list
);
3959 mutex_unlock(&event
->child_mutex
);
3964 * Read the performance event - simple non blocking version for now
3967 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
3969 u64 read_format
= event
->attr
.read_format
;
3973 * Return end-of-file for a read on a event that is in
3974 * error state (i.e. because it was pinned but it couldn't be
3975 * scheduled on to the CPU at some point).
3977 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3980 if (count
< event
->read_size
)
3983 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3984 if (read_format
& PERF_FORMAT_GROUP
)
3985 ret
= perf_read_group(event
, read_format
, buf
);
3987 ret
= perf_read_one(event
, read_format
, buf
);
3993 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3995 struct perf_event
*event
= file
->private_data
;
3996 struct perf_event_context
*ctx
;
3999 ctx
= perf_event_ctx_lock(event
);
4000 ret
= __perf_read(event
, buf
, count
);
4001 perf_event_ctx_unlock(event
, ctx
);
4006 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4008 struct perf_event
*event
= file
->private_data
;
4009 struct ring_buffer
*rb
;
4010 unsigned int events
= POLLHUP
;
4012 poll_wait(file
, &event
->waitq
, wait
);
4014 if (is_event_hup(event
))
4018 * Pin the event->rb by taking event->mmap_mutex; otherwise
4019 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4021 mutex_lock(&event
->mmap_mutex
);
4024 events
= atomic_xchg(&rb
->poll
, 0);
4025 mutex_unlock(&event
->mmap_mutex
);
4029 static void _perf_event_reset(struct perf_event
*event
)
4031 (void)perf_event_read(event
, false);
4032 local64_set(&event
->count
, 0);
4033 perf_event_update_userpage(event
);
4037 * Holding the top-level event's child_mutex means that any
4038 * descendant process that has inherited this event will block
4039 * in sync_child_event if it goes to exit, thus satisfying the
4040 * task existence requirements of perf_event_enable/disable.
4042 static void perf_event_for_each_child(struct perf_event
*event
,
4043 void (*func
)(struct perf_event
*))
4045 struct perf_event
*child
;
4047 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4049 mutex_lock(&event
->child_mutex
);
4051 list_for_each_entry(child
, &event
->child_list
, child_list
)
4053 mutex_unlock(&event
->child_mutex
);
4056 static void perf_event_for_each(struct perf_event
*event
,
4057 void (*func
)(struct perf_event
*))
4059 struct perf_event_context
*ctx
= event
->ctx
;
4060 struct perf_event
*sibling
;
4062 lockdep_assert_held(&ctx
->mutex
);
4064 event
= event
->group_leader
;
4066 perf_event_for_each_child(event
, func
);
4067 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4068 perf_event_for_each_child(sibling
, func
);
4071 struct period_event
{
4072 struct perf_event
*event
;
4076 static void ___perf_event_period(void *info
)
4078 struct period_event
*pe
= info
;
4079 struct perf_event
*event
= pe
->event
;
4080 u64 value
= pe
->value
;
4082 if (event
->attr
.freq
) {
4083 event
->attr
.sample_freq
= value
;
4085 event
->attr
.sample_period
= value
;
4086 event
->hw
.sample_period
= value
;
4089 local64_set(&event
->hw
.period_left
, 0);
4092 static int __perf_event_period(void *info
)
4094 struct period_event
*pe
= info
;
4095 struct perf_event
*event
= pe
->event
;
4096 struct perf_event_context
*ctx
= event
->ctx
;
4097 u64 value
= pe
->value
;
4100 raw_spin_lock(&ctx
->lock
);
4101 if (event
->attr
.freq
) {
4102 event
->attr
.sample_freq
= value
;
4104 event
->attr
.sample_period
= value
;
4105 event
->hw
.sample_period
= value
;
4108 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4110 perf_pmu_disable(ctx
->pmu
);
4111 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4114 local64_set(&event
->hw
.period_left
, 0);
4117 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4118 perf_pmu_enable(ctx
->pmu
);
4120 raw_spin_unlock(&ctx
->lock
);
4125 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4127 struct period_event pe
= { .event
= event
, };
4130 if (!is_sampling_event(event
))
4133 if (copy_from_user(&value
, arg
, sizeof(value
)))
4139 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4144 event_function_call(event
, __perf_event_period
,
4145 ___perf_event_period
, &pe
);
4150 static const struct file_operations perf_fops
;
4152 static inline int perf_fget_light(int fd
, struct fd
*p
)
4154 struct fd f
= fdget(fd
);
4158 if (f
.file
->f_op
!= &perf_fops
) {
4166 static int perf_event_set_output(struct perf_event
*event
,
4167 struct perf_event
*output_event
);
4168 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4169 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4171 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4173 void (*func
)(struct perf_event
*);
4177 case PERF_EVENT_IOC_ENABLE
:
4178 func
= _perf_event_enable
;
4180 case PERF_EVENT_IOC_DISABLE
:
4181 func
= _perf_event_disable
;
4183 case PERF_EVENT_IOC_RESET
:
4184 func
= _perf_event_reset
;
4187 case PERF_EVENT_IOC_REFRESH
:
4188 return _perf_event_refresh(event
, arg
);
4190 case PERF_EVENT_IOC_PERIOD
:
4191 return perf_event_period(event
, (u64 __user
*)arg
);
4193 case PERF_EVENT_IOC_ID
:
4195 u64 id
= primary_event_id(event
);
4197 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4202 case PERF_EVENT_IOC_SET_OUTPUT
:
4206 struct perf_event
*output_event
;
4208 ret
= perf_fget_light(arg
, &output
);
4211 output_event
= output
.file
->private_data
;
4212 ret
= perf_event_set_output(event
, output_event
);
4215 ret
= perf_event_set_output(event
, NULL
);
4220 case PERF_EVENT_IOC_SET_FILTER
:
4221 return perf_event_set_filter(event
, (void __user
*)arg
);
4223 case PERF_EVENT_IOC_SET_BPF
:
4224 return perf_event_set_bpf_prog(event
, arg
);
4230 if (flags
& PERF_IOC_FLAG_GROUP
)
4231 perf_event_for_each(event
, func
);
4233 perf_event_for_each_child(event
, func
);
4238 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4240 struct perf_event
*event
= file
->private_data
;
4241 struct perf_event_context
*ctx
;
4244 ctx
= perf_event_ctx_lock(event
);
4245 ret
= _perf_ioctl(event
, cmd
, arg
);
4246 perf_event_ctx_unlock(event
, ctx
);
4251 #ifdef CONFIG_COMPAT
4252 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4255 switch (_IOC_NR(cmd
)) {
4256 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4257 case _IOC_NR(PERF_EVENT_IOC_ID
):
4258 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4259 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4260 cmd
&= ~IOCSIZE_MASK
;
4261 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4265 return perf_ioctl(file
, cmd
, arg
);
4268 # define perf_compat_ioctl NULL
4271 int perf_event_task_enable(void)
4273 struct perf_event_context
*ctx
;
4274 struct perf_event
*event
;
4276 mutex_lock(¤t
->perf_event_mutex
);
4277 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4278 ctx
= perf_event_ctx_lock(event
);
4279 perf_event_for_each_child(event
, _perf_event_enable
);
4280 perf_event_ctx_unlock(event
, ctx
);
4282 mutex_unlock(¤t
->perf_event_mutex
);
4287 int perf_event_task_disable(void)
4289 struct perf_event_context
*ctx
;
4290 struct perf_event
*event
;
4292 mutex_lock(¤t
->perf_event_mutex
);
4293 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4294 ctx
= perf_event_ctx_lock(event
);
4295 perf_event_for_each_child(event
, _perf_event_disable
);
4296 perf_event_ctx_unlock(event
, ctx
);
4298 mutex_unlock(¤t
->perf_event_mutex
);
4303 static int perf_event_index(struct perf_event
*event
)
4305 if (event
->hw
.state
& PERF_HES_STOPPED
)
4308 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4311 return event
->pmu
->event_idx(event
);
4314 static void calc_timer_values(struct perf_event
*event
,
4321 *now
= perf_clock();
4322 ctx_time
= event
->shadow_ctx_time
+ *now
;
4323 *enabled
= ctx_time
- event
->tstamp_enabled
;
4324 *running
= ctx_time
- event
->tstamp_running
;
4327 static void perf_event_init_userpage(struct perf_event
*event
)
4329 struct perf_event_mmap_page
*userpg
;
4330 struct ring_buffer
*rb
;
4333 rb
= rcu_dereference(event
->rb
);
4337 userpg
= rb
->user_page
;
4339 /* Allow new userspace to detect that bit 0 is deprecated */
4340 userpg
->cap_bit0_is_deprecated
= 1;
4341 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4342 userpg
->data_offset
= PAGE_SIZE
;
4343 userpg
->data_size
= perf_data_size(rb
);
4349 void __weak
arch_perf_update_userpage(
4350 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4355 * Callers need to ensure there can be no nesting of this function, otherwise
4356 * the seqlock logic goes bad. We can not serialize this because the arch
4357 * code calls this from NMI context.
4359 void perf_event_update_userpage(struct perf_event
*event
)
4361 struct perf_event_mmap_page
*userpg
;
4362 struct ring_buffer
*rb
;
4363 u64 enabled
, running
, now
;
4366 rb
= rcu_dereference(event
->rb
);
4371 * compute total_time_enabled, total_time_running
4372 * based on snapshot values taken when the event
4373 * was last scheduled in.
4375 * we cannot simply called update_context_time()
4376 * because of locking issue as we can be called in
4379 calc_timer_values(event
, &now
, &enabled
, &running
);
4381 userpg
= rb
->user_page
;
4383 * Disable preemption so as to not let the corresponding user-space
4384 * spin too long if we get preempted.
4389 userpg
->index
= perf_event_index(event
);
4390 userpg
->offset
= perf_event_count(event
);
4392 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4394 userpg
->time_enabled
= enabled
+
4395 atomic64_read(&event
->child_total_time_enabled
);
4397 userpg
->time_running
= running
+
4398 atomic64_read(&event
->child_total_time_running
);
4400 arch_perf_update_userpage(event
, userpg
, now
);
4409 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4411 struct perf_event
*event
= vma
->vm_file
->private_data
;
4412 struct ring_buffer
*rb
;
4413 int ret
= VM_FAULT_SIGBUS
;
4415 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4416 if (vmf
->pgoff
== 0)
4422 rb
= rcu_dereference(event
->rb
);
4426 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4429 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4433 get_page(vmf
->page
);
4434 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4435 vmf
->page
->index
= vmf
->pgoff
;
4444 static void ring_buffer_attach(struct perf_event
*event
,
4445 struct ring_buffer
*rb
)
4447 struct ring_buffer
*old_rb
= NULL
;
4448 unsigned long flags
;
4452 * Should be impossible, we set this when removing
4453 * event->rb_entry and wait/clear when adding event->rb_entry.
4455 WARN_ON_ONCE(event
->rcu_pending
);
4458 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4459 list_del_rcu(&event
->rb_entry
);
4460 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4462 event
->rcu_batches
= get_state_synchronize_rcu();
4463 event
->rcu_pending
= 1;
4467 if (event
->rcu_pending
) {
4468 cond_synchronize_rcu(event
->rcu_batches
);
4469 event
->rcu_pending
= 0;
4472 spin_lock_irqsave(&rb
->event_lock
, flags
);
4473 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4474 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4477 rcu_assign_pointer(event
->rb
, rb
);
4480 ring_buffer_put(old_rb
);
4482 * Since we detached before setting the new rb, so that we
4483 * could attach the new rb, we could have missed a wakeup.
4486 wake_up_all(&event
->waitq
);
4490 static void ring_buffer_wakeup(struct perf_event
*event
)
4492 struct ring_buffer
*rb
;
4495 rb
= rcu_dereference(event
->rb
);
4497 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4498 wake_up_all(&event
->waitq
);
4503 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4505 struct ring_buffer
*rb
;
4508 rb
= rcu_dereference(event
->rb
);
4510 if (!atomic_inc_not_zero(&rb
->refcount
))
4518 void ring_buffer_put(struct ring_buffer
*rb
)
4520 if (!atomic_dec_and_test(&rb
->refcount
))
4523 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4525 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4528 static void perf_mmap_open(struct vm_area_struct
*vma
)
4530 struct perf_event
*event
= vma
->vm_file
->private_data
;
4532 atomic_inc(&event
->mmap_count
);
4533 atomic_inc(&event
->rb
->mmap_count
);
4536 atomic_inc(&event
->rb
->aux_mmap_count
);
4538 if (event
->pmu
->event_mapped
)
4539 event
->pmu
->event_mapped(event
);
4543 * A buffer can be mmap()ed multiple times; either directly through the same
4544 * event, or through other events by use of perf_event_set_output().
4546 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4547 * the buffer here, where we still have a VM context. This means we need
4548 * to detach all events redirecting to us.
4550 static void perf_mmap_close(struct vm_area_struct
*vma
)
4552 struct perf_event
*event
= vma
->vm_file
->private_data
;
4554 struct ring_buffer
*rb
= ring_buffer_get(event
);
4555 struct user_struct
*mmap_user
= rb
->mmap_user
;
4556 int mmap_locked
= rb
->mmap_locked
;
4557 unsigned long size
= perf_data_size(rb
);
4559 if (event
->pmu
->event_unmapped
)
4560 event
->pmu
->event_unmapped(event
);
4563 * rb->aux_mmap_count will always drop before rb->mmap_count and
4564 * event->mmap_count, so it is ok to use event->mmap_mutex to
4565 * serialize with perf_mmap here.
4567 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4568 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4569 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4570 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4573 mutex_unlock(&event
->mmap_mutex
);
4576 atomic_dec(&rb
->mmap_count
);
4578 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4581 ring_buffer_attach(event
, NULL
);
4582 mutex_unlock(&event
->mmap_mutex
);
4584 /* If there's still other mmap()s of this buffer, we're done. */
4585 if (atomic_read(&rb
->mmap_count
))
4589 * No other mmap()s, detach from all other events that might redirect
4590 * into the now unreachable buffer. Somewhat complicated by the
4591 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4595 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4596 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4598 * This event is en-route to free_event() which will
4599 * detach it and remove it from the list.
4605 mutex_lock(&event
->mmap_mutex
);
4607 * Check we didn't race with perf_event_set_output() which can
4608 * swizzle the rb from under us while we were waiting to
4609 * acquire mmap_mutex.
4611 * If we find a different rb; ignore this event, a next
4612 * iteration will no longer find it on the list. We have to
4613 * still restart the iteration to make sure we're not now
4614 * iterating the wrong list.
4616 if (event
->rb
== rb
)
4617 ring_buffer_attach(event
, NULL
);
4619 mutex_unlock(&event
->mmap_mutex
);
4623 * Restart the iteration; either we're on the wrong list or
4624 * destroyed its integrity by doing a deletion.
4631 * It could be there's still a few 0-ref events on the list; they'll
4632 * get cleaned up by free_event() -- they'll also still have their
4633 * ref on the rb and will free it whenever they are done with it.
4635 * Aside from that, this buffer is 'fully' detached and unmapped,
4636 * undo the VM accounting.
4639 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4640 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4641 free_uid(mmap_user
);
4644 ring_buffer_put(rb
); /* could be last */
4647 static const struct vm_operations_struct perf_mmap_vmops
= {
4648 .open
= perf_mmap_open
,
4649 .close
= perf_mmap_close
, /* non mergable */
4650 .fault
= perf_mmap_fault
,
4651 .page_mkwrite
= perf_mmap_fault
,
4654 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4656 struct perf_event
*event
= file
->private_data
;
4657 unsigned long user_locked
, user_lock_limit
;
4658 struct user_struct
*user
= current_user();
4659 unsigned long locked
, lock_limit
;
4660 struct ring_buffer
*rb
= NULL
;
4661 unsigned long vma_size
;
4662 unsigned long nr_pages
;
4663 long user_extra
= 0, extra
= 0;
4664 int ret
= 0, flags
= 0;
4667 * Don't allow mmap() of inherited per-task counters. This would
4668 * create a performance issue due to all children writing to the
4671 if (event
->cpu
== -1 && event
->attr
.inherit
)
4674 if (!(vma
->vm_flags
& VM_SHARED
))
4677 vma_size
= vma
->vm_end
- vma
->vm_start
;
4679 if (vma
->vm_pgoff
== 0) {
4680 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4683 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4684 * mapped, all subsequent mappings should have the same size
4685 * and offset. Must be above the normal perf buffer.
4687 u64 aux_offset
, aux_size
;
4692 nr_pages
= vma_size
/ PAGE_SIZE
;
4694 mutex_lock(&event
->mmap_mutex
);
4701 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4702 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4704 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4707 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4710 /* already mapped with a different offset */
4711 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4714 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4717 /* already mapped with a different size */
4718 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4721 if (!is_power_of_2(nr_pages
))
4724 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4727 if (rb_has_aux(rb
)) {
4728 atomic_inc(&rb
->aux_mmap_count
);
4733 atomic_set(&rb
->aux_mmap_count
, 1);
4734 user_extra
= nr_pages
;
4740 * If we have rb pages ensure they're a power-of-two number, so we
4741 * can do bitmasks instead of modulo.
4743 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4746 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4749 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4751 mutex_lock(&event
->mmap_mutex
);
4753 if (event
->rb
->nr_pages
!= nr_pages
) {
4758 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4760 * Raced against perf_mmap_close() through
4761 * perf_event_set_output(). Try again, hope for better
4764 mutex_unlock(&event
->mmap_mutex
);
4771 user_extra
= nr_pages
+ 1;
4774 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4777 * Increase the limit linearly with more CPUs:
4779 user_lock_limit
*= num_online_cpus();
4781 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4783 if (user_locked
> user_lock_limit
)
4784 extra
= user_locked
- user_lock_limit
;
4786 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4787 lock_limit
>>= PAGE_SHIFT
;
4788 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4790 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4791 !capable(CAP_IPC_LOCK
)) {
4796 WARN_ON(!rb
&& event
->rb
);
4798 if (vma
->vm_flags
& VM_WRITE
)
4799 flags
|= RING_BUFFER_WRITABLE
;
4802 rb
= rb_alloc(nr_pages
,
4803 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4811 atomic_set(&rb
->mmap_count
, 1);
4812 rb
->mmap_user
= get_current_user();
4813 rb
->mmap_locked
= extra
;
4815 ring_buffer_attach(event
, rb
);
4817 perf_event_init_userpage(event
);
4818 perf_event_update_userpage(event
);
4820 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4821 event
->attr
.aux_watermark
, flags
);
4823 rb
->aux_mmap_locked
= extra
;
4828 atomic_long_add(user_extra
, &user
->locked_vm
);
4829 vma
->vm_mm
->pinned_vm
+= extra
;
4831 atomic_inc(&event
->mmap_count
);
4833 atomic_dec(&rb
->mmap_count
);
4836 mutex_unlock(&event
->mmap_mutex
);
4839 * Since pinned accounting is per vm we cannot allow fork() to copy our
4842 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4843 vma
->vm_ops
= &perf_mmap_vmops
;
4845 if (event
->pmu
->event_mapped
)
4846 event
->pmu
->event_mapped(event
);
4851 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4853 struct inode
*inode
= file_inode(filp
);
4854 struct perf_event
*event
= filp
->private_data
;
4857 mutex_lock(&inode
->i_mutex
);
4858 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4859 mutex_unlock(&inode
->i_mutex
);
4867 static const struct file_operations perf_fops
= {
4868 .llseek
= no_llseek
,
4869 .release
= perf_release
,
4872 .unlocked_ioctl
= perf_ioctl
,
4873 .compat_ioctl
= perf_compat_ioctl
,
4875 .fasync
= perf_fasync
,
4881 * If there's data, ensure we set the poll() state and publish everything
4882 * to user-space before waking everybody up.
4885 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
4887 /* only the parent has fasync state */
4889 event
= event
->parent
;
4890 return &event
->fasync
;
4893 void perf_event_wakeup(struct perf_event
*event
)
4895 ring_buffer_wakeup(event
);
4897 if (event
->pending_kill
) {
4898 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
4899 event
->pending_kill
= 0;
4903 static void perf_pending_event(struct irq_work
*entry
)
4905 struct perf_event
*event
= container_of(entry
,
4906 struct perf_event
, pending
);
4909 rctx
= perf_swevent_get_recursion_context();
4911 * If we 'fail' here, that's OK, it means recursion is already disabled
4912 * and we won't recurse 'further'.
4915 if (event
->pending_disable
) {
4916 event
->pending_disable
= 0;
4917 __perf_event_disable(event
);
4920 if (event
->pending_wakeup
) {
4921 event
->pending_wakeup
= 0;
4922 perf_event_wakeup(event
);
4926 perf_swevent_put_recursion_context(rctx
);
4930 * We assume there is only KVM supporting the callbacks.
4931 * Later on, we might change it to a list if there is
4932 * another virtualization implementation supporting the callbacks.
4934 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4936 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4938 perf_guest_cbs
= cbs
;
4941 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4943 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4945 perf_guest_cbs
= NULL
;
4948 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4951 perf_output_sample_regs(struct perf_output_handle
*handle
,
4952 struct pt_regs
*regs
, u64 mask
)
4956 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4957 sizeof(mask
) * BITS_PER_BYTE
) {
4960 val
= perf_reg_value(regs
, bit
);
4961 perf_output_put(handle
, val
);
4965 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
4966 struct pt_regs
*regs
,
4967 struct pt_regs
*regs_user_copy
)
4969 if (user_mode(regs
)) {
4970 regs_user
->abi
= perf_reg_abi(current
);
4971 regs_user
->regs
= regs
;
4972 } else if (current
->mm
) {
4973 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
4975 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
4976 regs_user
->regs
= NULL
;
4980 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
4981 struct pt_regs
*regs
)
4983 regs_intr
->regs
= regs
;
4984 regs_intr
->abi
= perf_reg_abi(current
);
4989 * Get remaining task size from user stack pointer.
4991 * It'd be better to take stack vma map and limit this more
4992 * precisly, but there's no way to get it safely under interrupt,
4993 * so using TASK_SIZE as limit.
4995 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
4997 unsigned long addr
= perf_user_stack_pointer(regs
);
4999 if (!addr
|| addr
>= TASK_SIZE
)
5002 return TASK_SIZE
- addr
;
5006 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5007 struct pt_regs
*regs
)
5011 /* No regs, no stack pointer, no dump. */
5016 * Check if we fit in with the requested stack size into the:
5018 * If we don't, we limit the size to the TASK_SIZE.
5020 * - remaining sample size
5021 * If we don't, we customize the stack size to
5022 * fit in to the remaining sample size.
5025 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5026 stack_size
= min(stack_size
, (u16
) task_size
);
5028 /* Current header size plus static size and dynamic size. */
5029 header_size
+= 2 * sizeof(u64
);
5031 /* Do we fit in with the current stack dump size? */
5032 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5034 * If we overflow the maximum size for the sample,
5035 * we customize the stack dump size to fit in.
5037 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5038 stack_size
= round_up(stack_size
, sizeof(u64
));
5045 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5046 struct pt_regs
*regs
)
5048 /* Case of a kernel thread, nothing to dump */
5051 perf_output_put(handle
, size
);
5060 * - the size requested by user or the best one we can fit
5061 * in to the sample max size
5063 * - user stack dump data
5065 * - the actual dumped size
5069 perf_output_put(handle
, dump_size
);
5072 sp
= perf_user_stack_pointer(regs
);
5073 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5074 dyn_size
= dump_size
- rem
;
5076 perf_output_skip(handle
, rem
);
5079 perf_output_put(handle
, dyn_size
);
5083 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5084 struct perf_sample_data
*data
,
5085 struct perf_event
*event
)
5087 u64 sample_type
= event
->attr
.sample_type
;
5089 data
->type
= sample_type
;
5090 header
->size
+= event
->id_header_size
;
5092 if (sample_type
& PERF_SAMPLE_TID
) {
5093 /* namespace issues */
5094 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5095 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5098 if (sample_type
& PERF_SAMPLE_TIME
)
5099 data
->time
= perf_event_clock(event
);
5101 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5102 data
->id
= primary_event_id(event
);
5104 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5105 data
->stream_id
= event
->id
;
5107 if (sample_type
& PERF_SAMPLE_CPU
) {
5108 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5109 data
->cpu_entry
.reserved
= 0;
5113 void perf_event_header__init_id(struct perf_event_header
*header
,
5114 struct perf_sample_data
*data
,
5115 struct perf_event
*event
)
5117 if (event
->attr
.sample_id_all
)
5118 __perf_event_header__init_id(header
, data
, event
);
5121 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5122 struct perf_sample_data
*data
)
5124 u64 sample_type
= data
->type
;
5126 if (sample_type
& PERF_SAMPLE_TID
)
5127 perf_output_put(handle
, data
->tid_entry
);
5129 if (sample_type
& PERF_SAMPLE_TIME
)
5130 perf_output_put(handle
, data
->time
);
5132 if (sample_type
& PERF_SAMPLE_ID
)
5133 perf_output_put(handle
, data
->id
);
5135 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5136 perf_output_put(handle
, data
->stream_id
);
5138 if (sample_type
& PERF_SAMPLE_CPU
)
5139 perf_output_put(handle
, data
->cpu_entry
);
5141 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5142 perf_output_put(handle
, data
->id
);
5145 void perf_event__output_id_sample(struct perf_event
*event
,
5146 struct perf_output_handle
*handle
,
5147 struct perf_sample_data
*sample
)
5149 if (event
->attr
.sample_id_all
)
5150 __perf_event__output_id_sample(handle
, sample
);
5153 static void perf_output_read_one(struct perf_output_handle
*handle
,
5154 struct perf_event
*event
,
5155 u64 enabled
, u64 running
)
5157 u64 read_format
= event
->attr
.read_format
;
5161 values
[n
++] = perf_event_count(event
);
5162 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5163 values
[n
++] = enabled
+
5164 atomic64_read(&event
->child_total_time_enabled
);
5166 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5167 values
[n
++] = running
+
5168 atomic64_read(&event
->child_total_time_running
);
5170 if (read_format
& PERF_FORMAT_ID
)
5171 values
[n
++] = primary_event_id(event
);
5173 __output_copy(handle
, values
, n
* sizeof(u64
));
5177 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5179 static void perf_output_read_group(struct perf_output_handle
*handle
,
5180 struct perf_event
*event
,
5181 u64 enabled
, u64 running
)
5183 struct perf_event
*leader
= event
->group_leader
, *sub
;
5184 u64 read_format
= event
->attr
.read_format
;
5188 values
[n
++] = 1 + leader
->nr_siblings
;
5190 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5191 values
[n
++] = enabled
;
5193 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5194 values
[n
++] = running
;
5196 if (leader
!= event
)
5197 leader
->pmu
->read(leader
);
5199 values
[n
++] = perf_event_count(leader
);
5200 if (read_format
& PERF_FORMAT_ID
)
5201 values
[n
++] = primary_event_id(leader
);
5203 __output_copy(handle
, values
, n
* sizeof(u64
));
5205 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5208 if ((sub
!= event
) &&
5209 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5210 sub
->pmu
->read(sub
);
5212 values
[n
++] = perf_event_count(sub
);
5213 if (read_format
& PERF_FORMAT_ID
)
5214 values
[n
++] = primary_event_id(sub
);
5216 __output_copy(handle
, values
, n
* sizeof(u64
));
5220 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5221 PERF_FORMAT_TOTAL_TIME_RUNNING)
5223 static void perf_output_read(struct perf_output_handle
*handle
,
5224 struct perf_event
*event
)
5226 u64 enabled
= 0, running
= 0, now
;
5227 u64 read_format
= event
->attr
.read_format
;
5230 * compute total_time_enabled, total_time_running
5231 * based on snapshot values taken when the event
5232 * was last scheduled in.
5234 * we cannot simply called update_context_time()
5235 * because of locking issue as we are called in
5238 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5239 calc_timer_values(event
, &now
, &enabled
, &running
);
5241 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5242 perf_output_read_group(handle
, event
, enabled
, running
);
5244 perf_output_read_one(handle
, event
, enabled
, running
);
5247 void perf_output_sample(struct perf_output_handle
*handle
,
5248 struct perf_event_header
*header
,
5249 struct perf_sample_data
*data
,
5250 struct perf_event
*event
)
5252 u64 sample_type
= data
->type
;
5254 perf_output_put(handle
, *header
);
5256 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5257 perf_output_put(handle
, data
->id
);
5259 if (sample_type
& PERF_SAMPLE_IP
)
5260 perf_output_put(handle
, data
->ip
);
5262 if (sample_type
& PERF_SAMPLE_TID
)
5263 perf_output_put(handle
, data
->tid_entry
);
5265 if (sample_type
& PERF_SAMPLE_TIME
)
5266 perf_output_put(handle
, data
->time
);
5268 if (sample_type
& PERF_SAMPLE_ADDR
)
5269 perf_output_put(handle
, data
->addr
);
5271 if (sample_type
& PERF_SAMPLE_ID
)
5272 perf_output_put(handle
, data
->id
);
5274 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5275 perf_output_put(handle
, data
->stream_id
);
5277 if (sample_type
& PERF_SAMPLE_CPU
)
5278 perf_output_put(handle
, data
->cpu_entry
);
5280 if (sample_type
& PERF_SAMPLE_PERIOD
)
5281 perf_output_put(handle
, data
->period
);
5283 if (sample_type
& PERF_SAMPLE_READ
)
5284 perf_output_read(handle
, event
);
5286 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5287 if (data
->callchain
) {
5290 if (data
->callchain
)
5291 size
+= data
->callchain
->nr
;
5293 size
*= sizeof(u64
);
5295 __output_copy(handle
, data
->callchain
, size
);
5298 perf_output_put(handle
, nr
);
5302 if (sample_type
& PERF_SAMPLE_RAW
) {
5304 u32 raw_size
= data
->raw
->size
;
5305 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5306 sizeof(u64
)) - sizeof(u32
);
5309 perf_output_put(handle
, real_size
);
5310 __output_copy(handle
, data
->raw
->data
, raw_size
);
5311 if (real_size
- raw_size
)
5312 __output_copy(handle
, &zero
, real_size
- raw_size
);
5318 .size
= sizeof(u32
),
5321 perf_output_put(handle
, raw
);
5325 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5326 if (data
->br_stack
) {
5329 size
= data
->br_stack
->nr
5330 * sizeof(struct perf_branch_entry
);
5332 perf_output_put(handle
, data
->br_stack
->nr
);
5333 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5336 * we always store at least the value of nr
5339 perf_output_put(handle
, nr
);
5343 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5344 u64 abi
= data
->regs_user
.abi
;
5347 * If there are no regs to dump, notice it through
5348 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5350 perf_output_put(handle
, abi
);
5353 u64 mask
= event
->attr
.sample_regs_user
;
5354 perf_output_sample_regs(handle
,
5355 data
->regs_user
.regs
,
5360 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5361 perf_output_sample_ustack(handle
,
5362 data
->stack_user_size
,
5363 data
->regs_user
.regs
);
5366 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5367 perf_output_put(handle
, data
->weight
);
5369 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5370 perf_output_put(handle
, data
->data_src
.val
);
5372 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5373 perf_output_put(handle
, data
->txn
);
5375 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5376 u64 abi
= data
->regs_intr
.abi
;
5378 * If there are no regs to dump, notice it through
5379 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5381 perf_output_put(handle
, abi
);
5384 u64 mask
= event
->attr
.sample_regs_intr
;
5386 perf_output_sample_regs(handle
,
5387 data
->regs_intr
.regs
,
5392 if (!event
->attr
.watermark
) {
5393 int wakeup_events
= event
->attr
.wakeup_events
;
5395 if (wakeup_events
) {
5396 struct ring_buffer
*rb
= handle
->rb
;
5397 int events
= local_inc_return(&rb
->events
);
5399 if (events
>= wakeup_events
) {
5400 local_sub(wakeup_events
, &rb
->events
);
5401 local_inc(&rb
->wakeup
);
5407 void perf_prepare_sample(struct perf_event_header
*header
,
5408 struct perf_sample_data
*data
,
5409 struct perf_event
*event
,
5410 struct pt_regs
*regs
)
5412 u64 sample_type
= event
->attr
.sample_type
;
5414 header
->type
= PERF_RECORD_SAMPLE
;
5415 header
->size
= sizeof(*header
) + event
->header_size
;
5418 header
->misc
|= perf_misc_flags(regs
);
5420 __perf_event_header__init_id(header
, data
, event
);
5422 if (sample_type
& PERF_SAMPLE_IP
)
5423 data
->ip
= perf_instruction_pointer(regs
);
5425 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5428 data
->callchain
= perf_callchain(event
, regs
);
5430 if (data
->callchain
)
5431 size
+= data
->callchain
->nr
;
5433 header
->size
+= size
* sizeof(u64
);
5436 if (sample_type
& PERF_SAMPLE_RAW
) {
5437 int size
= sizeof(u32
);
5440 size
+= data
->raw
->size
;
5442 size
+= sizeof(u32
);
5444 header
->size
+= round_up(size
, sizeof(u64
));
5447 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5448 int size
= sizeof(u64
); /* nr */
5449 if (data
->br_stack
) {
5450 size
+= data
->br_stack
->nr
5451 * sizeof(struct perf_branch_entry
);
5453 header
->size
+= size
;
5456 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5457 perf_sample_regs_user(&data
->regs_user
, regs
,
5458 &data
->regs_user_copy
);
5460 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5461 /* regs dump ABI info */
5462 int size
= sizeof(u64
);
5464 if (data
->regs_user
.regs
) {
5465 u64 mask
= event
->attr
.sample_regs_user
;
5466 size
+= hweight64(mask
) * sizeof(u64
);
5469 header
->size
+= size
;
5472 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5474 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5475 * processed as the last one or have additional check added
5476 * in case new sample type is added, because we could eat
5477 * up the rest of the sample size.
5479 u16 stack_size
= event
->attr
.sample_stack_user
;
5480 u16 size
= sizeof(u64
);
5482 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5483 data
->regs_user
.regs
);
5486 * If there is something to dump, add space for the dump
5487 * itself and for the field that tells the dynamic size,
5488 * which is how many have been actually dumped.
5491 size
+= sizeof(u64
) + stack_size
;
5493 data
->stack_user_size
= stack_size
;
5494 header
->size
+= size
;
5497 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5498 /* regs dump ABI info */
5499 int size
= sizeof(u64
);
5501 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5503 if (data
->regs_intr
.regs
) {
5504 u64 mask
= event
->attr
.sample_regs_intr
;
5506 size
+= hweight64(mask
) * sizeof(u64
);
5509 header
->size
+= size
;
5513 void perf_event_output(struct perf_event
*event
,
5514 struct perf_sample_data
*data
,
5515 struct pt_regs
*regs
)
5517 struct perf_output_handle handle
;
5518 struct perf_event_header header
;
5520 /* protect the callchain buffers */
5523 perf_prepare_sample(&header
, data
, event
, regs
);
5525 if (perf_output_begin(&handle
, event
, header
.size
))
5528 perf_output_sample(&handle
, &header
, data
, event
);
5530 perf_output_end(&handle
);
5540 struct perf_read_event
{
5541 struct perf_event_header header
;
5548 perf_event_read_event(struct perf_event
*event
,
5549 struct task_struct
*task
)
5551 struct perf_output_handle handle
;
5552 struct perf_sample_data sample
;
5553 struct perf_read_event read_event
= {
5555 .type
= PERF_RECORD_READ
,
5557 .size
= sizeof(read_event
) + event
->read_size
,
5559 .pid
= perf_event_pid(event
, task
),
5560 .tid
= perf_event_tid(event
, task
),
5564 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5565 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5569 perf_output_put(&handle
, read_event
);
5570 perf_output_read(&handle
, event
);
5571 perf_event__output_id_sample(event
, &handle
, &sample
);
5573 perf_output_end(&handle
);
5576 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5579 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5580 perf_event_aux_output_cb output
,
5583 struct perf_event
*event
;
5585 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5586 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5588 if (!event_filter_match(event
))
5590 output(event
, data
);
5595 perf_event_aux_task_ctx(perf_event_aux_output_cb output
, void *data
,
5596 struct perf_event_context
*task_ctx
)
5600 perf_event_aux_ctx(task_ctx
, output
, data
);
5606 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5607 struct perf_event_context
*task_ctx
)
5609 struct perf_cpu_context
*cpuctx
;
5610 struct perf_event_context
*ctx
;
5615 * If we have task_ctx != NULL we only notify
5616 * the task context itself. The task_ctx is set
5617 * only for EXIT events before releasing task
5621 perf_event_aux_task_ctx(output
, data
, task_ctx
);
5626 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5627 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5628 if (cpuctx
->unique_pmu
!= pmu
)
5630 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5631 ctxn
= pmu
->task_ctx_nr
;
5634 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5636 perf_event_aux_ctx(ctx
, output
, data
);
5638 put_cpu_ptr(pmu
->pmu_cpu_context
);
5644 * task tracking -- fork/exit
5646 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5649 struct perf_task_event
{
5650 struct task_struct
*task
;
5651 struct perf_event_context
*task_ctx
;
5654 struct perf_event_header header
;
5664 static int perf_event_task_match(struct perf_event
*event
)
5666 return event
->attr
.comm
|| event
->attr
.mmap
||
5667 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5671 static void perf_event_task_output(struct perf_event
*event
,
5674 struct perf_task_event
*task_event
= data
;
5675 struct perf_output_handle handle
;
5676 struct perf_sample_data sample
;
5677 struct task_struct
*task
= task_event
->task
;
5678 int ret
, size
= task_event
->event_id
.header
.size
;
5680 if (!perf_event_task_match(event
))
5683 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5685 ret
= perf_output_begin(&handle
, event
,
5686 task_event
->event_id
.header
.size
);
5690 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5691 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5693 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5694 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5696 task_event
->event_id
.time
= perf_event_clock(event
);
5698 perf_output_put(&handle
, task_event
->event_id
);
5700 perf_event__output_id_sample(event
, &handle
, &sample
);
5702 perf_output_end(&handle
);
5704 task_event
->event_id
.header
.size
= size
;
5707 static void perf_event_task(struct task_struct
*task
,
5708 struct perf_event_context
*task_ctx
,
5711 struct perf_task_event task_event
;
5713 if (!atomic_read(&nr_comm_events
) &&
5714 !atomic_read(&nr_mmap_events
) &&
5715 !atomic_read(&nr_task_events
))
5718 task_event
= (struct perf_task_event
){
5720 .task_ctx
= task_ctx
,
5723 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5725 .size
= sizeof(task_event
.event_id
),
5735 perf_event_aux(perf_event_task_output
,
5740 void perf_event_fork(struct task_struct
*task
)
5742 perf_event_task(task
, NULL
, 1);
5749 struct perf_comm_event
{
5750 struct task_struct
*task
;
5755 struct perf_event_header header
;
5762 static int perf_event_comm_match(struct perf_event
*event
)
5764 return event
->attr
.comm
;
5767 static void perf_event_comm_output(struct perf_event
*event
,
5770 struct perf_comm_event
*comm_event
= data
;
5771 struct perf_output_handle handle
;
5772 struct perf_sample_data sample
;
5773 int size
= comm_event
->event_id
.header
.size
;
5776 if (!perf_event_comm_match(event
))
5779 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5780 ret
= perf_output_begin(&handle
, event
,
5781 comm_event
->event_id
.header
.size
);
5786 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5787 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5789 perf_output_put(&handle
, comm_event
->event_id
);
5790 __output_copy(&handle
, comm_event
->comm
,
5791 comm_event
->comm_size
);
5793 perf_event__output_id_sample(event
, &handle
, &sample
);
5795 perf_output_end(&handle
);
5797 comm_event
->event_id
.header
.size
= size
;
5800 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5802 char comm
[TASK_COMM_LEN
];
5805 memset(comm
, 0, sizeof(comm
));
5806 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5807 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5809 comm_event
->comm
= comm
;
5810 comm_event
->comm_size
= size
;
5812 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5814 perf_event_aux(perf_event_comm_output
,
5819 void perf_event_comm(struct task_struct
*task
, bool exec
)
5821 struct perf_comm_event comm_event
;
5823 if (!atomic_read(&nr_comm_events
))
5826 comm_event
= (struct perf_comm_event
){
5832 .type
= PERF_RECORD_COMM
,
5833 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5841 perf_event_comm_event(&comm_event
);
5848 struct perf_mmap_event
{
5849 struct vm_area_struct
*vma
;
5851 const char *file_name
;
5859 struct perf_event_header header
;
5869 static int perf_event_mmap_match(struct perf_event
*event
,
5872 struct perf_mmap_event
*mmap_event
= data
;
5873 struct vm_area_struct
*vma
= mmap_event
->vma
;
5874 int executable
= vma
->vm_flags
& VM_EXEC
;
5876 return (!executable
&& event
->attr
.mmap_data
) ||
5877 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5880 static void perf_event_mmap_output(struct perf_event
*event
,
5883 struct perf_mmap_event
*mmap_event
= data
;
5884 struct perf_output_handle handle
;
5885 struct perf_sample_data sample
;
5886 int size
= mmap_event
->event_id
.header
.size
;
5889 if (!perf_event_mmap_match(event
, data
))
5892 if (event
->attr
.mmap2
) {
5893 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5894 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5895 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5896 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5897 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5898 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5899 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5902 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5903 ret
= perf_output_begin(&handle
, event
,
5904 mmap_event
->event_id
.header
.size
);
5908 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5909 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5911 perf_output_put(&handle
, mmap_event
->event_id
);
5913 if (event
->attr
.mmap2
) {
5914 perf_output_put(&handle
, mmap_event
->maj
);
5915 perf_output_put(&handle
, mmap_event
->min
);
5916 perf_output_put(&handle
, mmap_event
->ino
);
5917 perf_output_put(&handle
, mmap_event
->ino_generation
);
5918 perf_output_put(&handle
, mmap_event
->prot
);
5919 perf_output_put(&handle
, mmap_event
->flags
);
5922 __output_copy(&handle
, mmap_event
->file_name
,
5923 mmap_event
->file_size
);
5925 perf_event__output_id_sample(event
, &handle
, &sample
);
5927 perf_output_end(&handle
);
5929 mmap_event
->event_id
.header
.size
= size
;
5932 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5934 struct vm_area_struct
*vma
= mmap_event
->vma
;
5935 struct file
*file
= vma
->vm_file
;
5936 int maj
= 0, min
= 0;
5937 u64 ino
= 0, gen
= 0;
5938 u32 prot
= 0, flags
= 0;
5945 struct inode
*inode
;
5948 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5954 * d_path() works from the end of the rb backwards, so we
5955 * need to add enough zero bytes after the string to handle
5956 * the 64bit alignment we do later.
5958 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
5963 inode
= file_inode(vma
->vm_file
);
5964 dev
= inode
->i_sb
->s_dev
;
5966 gen
= inode
->i_generation
;
5970 if (vma
->vm_flags
& VM_READ
)
5972 if (vma
->vm_flags
& VM_WRITE
)
5974 if (vma
->vm_flags
& VM_EXEC
)
5977 if (vma
->vm_flags
& VM_MAYSHARE
)
5980 flags
= MAP_PRIVATE
;
5982 if (vma
->vm_flags
& VM_DENYWRITE
)
5983 flags
|= MAP_DENYWRITE
;
5984 if (vma
->vm_flags
& VM_MAYEXEC
)
5985 flags
|= MAP_EXECUTABLE
;
5986 if (vma
->vm_flags
& VM_LOCKED
)
5987 flags
|= MAP_LOCKED
;
5988 if (vma
->vm_flags
& VM_HUGETLB
)
5989 flags
|= MAP_HUGETLB
;
5993 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
5994 name
= (char *) vma
->vm_ops
->name(vma
);
5999 name
= (char *)arch_vma_name(vma
);
6003 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6004 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6008 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6009 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6019 strlcpy(tmp
, name
, sizeof(tmp
));
6023 * Since our buffer works in 8 byte units we need to align our string
6024 * size to a multiple of 8. However, we must guarantee the tail end is
6025 * zero'd out to avoid leaking random bits to userspace.
6027 size
= strlen(name
)+1;
6028 while (!IS_ALIGNED(size
, sizeof(u64
)))
6029 name
[size
++] = '\0';
6031 mmap_event
->file_name
= name
;
6032 mmap_event
->file_size
= size
;
6033 mmap_event
->maj
= maj
;
6034 mmap_event
->min
= min
;
6035 mmap_event
->ino
= ino
;
6036 mmap_event
->ino_generation
= gen
;
6037 mmap_event
->prot
= prot
;
6038 mmap_event
->flags
= flags
;
6040 if (!(vma
->vm_flags
& VM_EXEC
))
6041 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6043 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6045 perf_event_aux(perf_event_mmap_output
,
6052 void perf_event_mmap(struct vm_area_struct
*vma
)
6054 struct perf_mmap_event mmap_event
;
6056 if (!atomic_read(&nr_mmap_events
))
6059 mmap_event
= (struct perf_mmap_event
){
6065 .type
= PERF_RECORD_MMAP
,
6066 .misc
= PERF_RECORD_MISC_USER
,
6071 .start
= vma
->vm_start
,
6072 .len
= vma
->vm_end
- vma
->vm_start
,
6073 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6075 /* .maj (attr_mmap2 only) */
6076 /* .min (attr_mmap2 only) */
6077 /* .ino (attr_mmap2 only) */
6078 /* .ino_generation (attr_mmap2 only) */
6079 /* .prot (attr_mmap2 only) */
6080 /* .flags (attr_mmap2 only) */
6083 perf_event_mmap_event(&mmap_event
);
6086 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6087 unsigned long size
, u64 flags
)
6089 struct perf_output_handle handle
;
6090 struct perf_sample_data sample
;
6091 struct perf_aux_event
{
6092 struct perf_event_header header
;
6098 .type
= PERF_RECORD_AUX
,
6100 .size
= sizeof(rec
),
6108 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6109 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6114 perf_output_put(&handle
, rec
);
6115 perf_event__output_id_sample(event
, &handle
, &sample
);
6117 perf_output_end(&handle
);
6121 * Lost/dropped samples logging
6123 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6125 struct perf_output_handle handle
;
6126 struct perf_sample_data sample
;
6130 struct perf_event_header header
;
6132 } lost_samples_event
= {
6134 .type
= PERF_RECORD_LOST_SAMPLES
,
6136 .size
= sizeof(lost_samples_event
),
6141 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6143 ret
= perf_output_begin(&handle
, event
,
6144 lost_samples_event
.header
.size
);
6148 perf_output_put(&handle
, lost_samples_event
);
6149 perf_event__output_id_sample(event
, &handle
, &sample
);
6150 perf_output_end(&handle
);
6154 * context_switch tracking
6157 struct perf_switch_event
{
6158 struct task_struct
*task
;
6159 struct task_struct
*next_prev
;
6162 struct perf_event_header header
;
6168 static int perf_event_switch_match(struct perf_event
*event
)
6170 return event
->attr
.context_switch
;
6173 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6175 struct perf_switch_event
*se
= data
;
6176 struct perf_output_handle handle
;
6177 struct perf_sample_data sample
;
6180 if (!perf_event_switch_match(event
))
6183 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6184 if (event
->ctx
->task
) {
6185 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6186 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6188 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6189 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6190 se
->event_id
.next_prev_pid
=
6191 perf_event_pid(event
, se
->next_prev
);
6192 se
->event_id
.next_prev_tid
=
6193 perf_event_tid(event
, se
->next_prev
);
6196 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6198 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6202 if (event
->ctx
->task
)
6203 perf_output_put(&handle
, se
->event_id
.header
);
6205 perf_output_put(&handle
, se
->event_id
);
6207 perf_event__output_id_sample(event
, &handle
, &sample
);
6209 perf_output_end(&handle
);
6212 static void perf_event_switch(struct task_struct
*task
,
6213 struct task_struct
*next_prev
, bool sched_in
)
6215 struct perf_switch_event switch_event
;
6217 /* N.B. caller checks nr_switch_events != 0 */
6219 switch_event
= (struct perf_switch_event
){
6221 .next_prev
= next_prev
,
6225 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6228 /* .next_prev_pid */
6229 /* .next_prev_tid */
6233 perf_event_aux(perf_event_switch_output
,
6239 * IRQ throttle logging
6242 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6244 struct perf_output_handle handle
;
6245 struct perf_sample_data sample
;
6249 struct perf_event_header header
;
6253 } throttle_event
= {
6255 .type
= PERF_RECORD_THROTTLE
,
6257 .size
= sizeof(throttle_event
),
6259 .time
= perf_event_clock(event
),
6260 .id
= primary_event_id(event
),
6261 .stream_id
= event
->id
,
6265 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6267 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6269 ret
= perf_output_begin(&handle
, event
,
6270 throttle_event
.header
.size
);
6274 perf_output_put(&handle
, throttle_event
);
6275 perf_event__output_id_sample(event
, &handle
, &sample
);
6276 perf_output_end(&handle
);
6279 static void perf_log_itrace_start(struct perf_event
*event
)
6281 struct perf_output_handle handle
;
6282 struct perf_sample_data sample
;
6283 struct perf_aux_event
{
6284 struct perf_event_header header
;
6291 event
= event
->parent
;
6293 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6294 event
->hw
.itrace_started
)
6297 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6298 rec
.header
.misc
= 0;
6299 rec
.header
.size
= sizeof(rec
);
6300 rec
.pid
= perf_event_pid(event
, current
);
6301 rec
.tid
= perf_event_tid(event
, current
);
6303 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6304 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6309 perf_output_put(&handle
, rec
);
6310 perf_event__output_id_sample(event
, &handle
, &sample
);
6312 perf_output_end(&handle
);
6316 * Generic event overflow handling, sampling.
6319 static int __perf_event_overflow(struct perf_event
*event
,
6320 int throttle
, struct perf_sample_data
*data
,
6321 struct pt_regs
*regs
)
6323 int events
= atomic_read(&event
->event_limit
);
6324 struct hw_perf_event
*hwc
= &event
->hw
;
6329 * Non-sampling counters might still use the PMI to fold short
6330 * hardware counters, ignore those.
6332 if (unlikely(!is_sampling_event(event
)))
6335 seq
= __this_cpu_read(perf_throttled_seq
);
6336 if (seq
!= hwc
->interrupts_seq
) {
6337 hwc
->interrupts_seq
= seq
;
6338 hwc
->interrupts
= 1;
6341 if (unlikely(throttle
6342 && hwc
->interrupts
>= max_samples_per_tick
)) {
6343 __this_cpu_inc(perf_throttled_count
);
6344 hwc
->interrupts
= MAX_INTERRUPTS
;
6345 perf_log_throttle(event
, 0);
6346 tick_nohz_full_kick();
6351 if (event
->attr
.freq
) {
6352 u64 now
= perf_clock();
6353 s64 delta
= now
- hwc
->freq_time_stamp
;
6355 hwc
->freq_time_stamp
= now
;
6357 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6358 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6362 * XXX event_limit might not quite work as expected on inherited
6366 event
->pending_kill
= POLL_IN
;
6367 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6369 event
->pending_kill
= POLL_HUP
;
6370 event
->pending_disable
= 1;
6371 irq_work_queue(&event
->pending
);
6374 if (event
->overflow_handler
)
6375 event
->overflow_handler(event
, data
, regs
);
6377 perf_event_output(event
, data
, regs
);
6379 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6380 event
->pending_wakeup
= 1;
6381 irq_work_queue(&event
->pending
);
6387 int perf_event_overflow(struct perf_event
*event
,
6388 struct perf_sample_data
*data
,
6389 struct pt_regs
*regs
)
6391 return __perf_event_overflow(event
, 1, data
, regs
);
6395 * Generic software event infrastructure
6398 struct swevent_htable
{
6399 struct swevent_hlist
*swevent_hlist
;
6400 struct mutex hlist_mutex
;
6403 /* Recursion avoidance in each contexts */
6404 int recursion
[PERF_NR_CONTEXTS
];
6407 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6410 * We directly increment event->count and keep a second value in
6411 * event->hw.period_left to count intervals. This period event
6412 * is kept in the range [-sample_period, 0] so that we can use the
6416 u64
perf_swevent_set_period(struct perf_event
*event
)
6418 struct hw_perf_event
*hwc
= &event
->hw
;
6419 u64 period
= hwc
->last_period
;
6423 hwc
->last_period
= hwc
->sample_period
;
6426 old
= val
= local64_read(&hwc
->period_left
);
6430 nr
= div64_u64(period
+ val
, period
);
6431 offset
= nr
* period
;
6433 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6439 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6440 struct perf_sample_data
*data
,
6441 struct pt_regs
*regs
)
6443 struct hw_perf_event
*hwc
= &event
->hw
;
6447 overflow
= perf_swevent_set_period(event
);
6449 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6452 for (; overflow
; overflow
--) {
6453 if (__perf_event_overflow(event
, throttle
,
6456 * We inhibit the overflow from happening when
6457 * hwc->interrupts == MAX_INTERRUPTS.
6465 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6466 struct perf_sample_data
*data
,
6467 struct pt_regs
*regs
)
6469 struct hw_perf_event
*hwc
= &event
->hw
;
6471 local64_add(nr
, &event
->count
);
6476 if (!is_sampling_event(event
))
6479 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6481 return perf_swevent_overflow(event
, 1, data
, regs
);
6483 data
->period
= event
->hw
.last_period
;
6485 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6486 return perf_swevent_overflow(event
, 1, data
, regs
);
6488 if (local64_add_negative(nr
, &hwc
->period_left
))
6491 perf_swevent_overflow(event
, 0, data
, regs
);
6494 static int perf_exclude_event(struct perf_event
*event
,
6495 struct pt_regs
*regs
)
6497 if (event
->hw
.state
& PERF_HES_STOPPED
)
6501 if (event
->attr
.exclude_user
&& user_mode(regs
))
6504 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6511 static int perf_swevent_match(struct perf_event
*event
,
6512 enum perf_type_id type
,
6514 struct perf_sample_data
*data
,
6515 struct pt_regs
*regs
)
6517 if (event
->attr
.type
!= type
)
6520 if (event
->attr
.config
!= event_id
)
6523 if (perf_exclude_event(event
, regs
))
6529 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6531 u64 val
= event_id
| (type
<< 32);
6533 return hash_64(val
, SWEVENT_HLIST_BITS
);
6536 static inline struct hlist_head
*
6537 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6539 u64 hash
= swevent_hash(type
, event_id
);
6541 return &hlist
->heads
[hash
];
6544 /* For the read side: events when they trigger */
6545 static inline struct hlist_head
*
6546 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6548 struct swevent_hlist
*hlist
;
6550 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6554 return __find_swevent_head(hlist
, type
, event_id
);
6557 /* For the event head insertion and removal in the hlist */
6558 static inline struct hlist_head
*
6559 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6561 struct swevent_hlist
*hlist
;
6562 u32 event_id
= event
->attr
.config
;
6563 u64 type
= event
->attr
.type
;
6566 * Event scheduling is always serialized against hlist allocation
6567 * and release. Which makes the protected version suitable here.
6568 * The context lock guarantees that.
6570 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6571 lockdep_is_held(&event
->ctx
->lock
));
6575 return __find_swevent_head(hlist
, type
, event_id
);
6578 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6580 struct perf_sample_data
*data
,
6581 struct pt_regs
*regs
)
6583 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6584 struct perf_event
*event
;
6585 struct hlist_head
*head
;
6588 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6592 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6593 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6594 perf_swevent_event(event
, nr
, data
, regs
);
6600 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6602 int perf_swevent_get_recursion_context(void)
6604 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6606 return get_recursion_context(swhash
->recursion
);
6608 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6610 inline void perf_swevent_put_recursion_context(int rctx
)
6612 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6614 put_recursion_context(swhash
->recursion
, rctx
);
6617 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6619 struct perf_sample_data data
;
6621 if (WARN_ON_ONCE(!regs
))
6624 perf_sample_data_init(&data
, addr
, 0);
6625 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6628 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6632 preempt_disable_notrace();
6633 rctx
= perf_swevent_get_recursion_context();
6634 if (unlikely(rctx
< 0))
6637 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6639 perf_swevent_put_recursion_context(rctx
);
6641 preempt_enable_notrace();
6644 static void perf_swevent_read(struct perf_event
*event
)
6648 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6650 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6651 struct hw_perf_event
*hwc
= &event
->hw
;
6652 struct hlist_head
*head
;
6654 if (is_sampling_event(event
)) {
6655 hwc
->last_period
= hwc
->sample_period
;
6656 perf_swevent_set_period(event
);
6659 hwc
->state
= !(flags
& PERF_EF_START
);
6661 head
= find_swevent_head(swhash
, event
);
6662 if (WARN_ON_ONCE(!head
))
6665 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6666 perf_event_update_userpage(event
);
6671 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6673 hlist_del_rcu(&event
->hlist_entry
);
6676 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6678 event
->hw
.state
= 0;
6681 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6683 event
->hw
.state
= PERF_HES_STOPPED
;
6686 /* Deref the hlist from the update side */
6687 static inline struct swevent_hlist
*
6688 swevent_hlist_deref(struct swevent_htable
*swhash
)
6690 return rcu_dereference_protected(swhash
->swevent_hlist
,
6691 lockdep_is_held(&swhash
->hlist_mutex
));
6694 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6696 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6701 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6702 kfree_rcu(hlist
, rcu_head
);
6705 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6707 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6709 mutex_lock(&swhash
->hlist_mutex
);
6711 if (!--swhash
->hlist_refcount
)
6712 swevent_hlist_release(swhash
);
6714 mutex_unlock(&swhash
->hlist_mutex
);
6717 static void swevent_hlist_put(struct perf_event
*event
)
6721 for_each_possible_cpu(cpu
)
6722 swevent_hlist_put_cpu(event
, cpu
);
6725 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6727 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6730 mutex_lock(&swhash
->hlist_mutex
);
6731 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6732 struct swevent_hlist
*hlist
;
6734 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6739 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6741 swhash
->hlist_refcount
++;
6743 mutex_unlock(&swhash
->hlist_mutex
);
6748 static int swevent_hlist_get(struct perf_event
*event
)
6751 int cpu
, failed_cpu
;
6754 for_each_possible_cpu(cpu
) {
6755 err
= swevent_hlist_get_cpu(event
, cpu
);
6765 for_each_possible_cpu(cpu
) {
6766 if (cpu
== failed_cpu
)
6768 swevent_hlist_put_cpu(event
, cpu
);
6775 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6777 static void sw_perf_event_destroy(struct perf_event
*event
)
6779 u64 event_id
= event
->attr
.config
;
6781 WARN_ON(event
->parent
);
6783 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6784 swevent_hlist_put(event
);
6787 static int perf_swevent_init(struct perf_event
*event
)
6789 u64 event_id
= event
->attr
.config
;
6791 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6795 * no branch sampling for software events
6797 if (has_branch_stack(event
))
6801 case PERF_COUNT_SW_CPU_CLOCK
:
6802 case PERF_COUNT_SW_TASK_CLOCK
:
6809 if (event_id
>= PERF_COUNT_SW_MAX
)
6812 if (!event
->parent
) {
6815 err
= swevent_hlist_get(event
);
6819 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6820 event
->destroy
= sw_perf_event_destroy
;
6826 static struct pmu perf_swevent
= {
6827 .task_ctx_nr
= perf_sw_context
,
6829 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6831 .event_init
= perf_swevent_init
,
6832 .add
= perf_swevent_add
,
6833 .del
= perf_swevent_del
,
6834 .start
= perf_swevent_start
,
6835 .stop
= perf_swevent_stop
,
6836 .read
= perf_swevent_read
,
6839 #ifdef CONFIG_EVENT_TRACING
6841 static int perf_tp_filter_match(struct perf_event
*event
,
6842 struct perf_sample_data
*data
)
6844 void *record
= data
->raw
->data
;
6846 /* only top level events have filters set */
6848 event
= event
->parent
;
6850 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6855 static int perf_tp_event_match(struct perf_event
*event
,
6856 struct perf_sample_data
*data
,
6857 struct pt_regs
*regs
)
6859 if (event
->hw
.state
& PERF_HES_STOPPED
)
6862 * All tracepoints are from kernel-space.
6864 if (event
->attr
.exclude_kernel
)
6867 if (!perf_tp_filter_match(event
, data
))
6873 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6874 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6875 struct task_struct
*task
)
6877 struct perf_sample_data data
;
6878 struct perf_event
*event
;
6880 struct perf_raw_record raw
= {
6885 perf_sample_data_init(&data
, addr
, 0);
6888 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6889 if (perf_tp_event_match(event
, &data
, regs
))
6890 perf_swevent_event(event
, count
, &data
, regs
);
6894 * If we got specified a target task, also iterate its context and
6895 * deliver this event there too.
6897 if (task
&& task
!= current
) {
6898 struct perf_event_context
*ctx
;
6899 struct trace_entry
*entry
= record
;
6902 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6906 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6907 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6909 if (event
->attr
.config
!= entry
->type
)
6911 if (perf_tp_event_match(event
, &data
, regs
))
6912 perf_swevent_event(event
, count
, &data
, regs
);
6918 perf_swevent_put_recursion_context(rctx
);
6920 EXPORT_SYMBOL_GPL(perf_tp_event
);
6922 static void tp_perf_event_destroy(struct perf_event
*event
)
6924 perf_trace_destroy(event
);
6927 static int perf_tp_event_init(struct perf_event
*event
)
6931 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6935 * no branch sampling for tracepoint events
6937 if (has_branch_stack(event
))
6940 err
= perf_trace_init(event
);
6944 event
->destroy
= tp_perf_event_destroy
;
6949 static struct pmu perf_tracepoint
= {
6950 .task_ctx_nr
= perf_sw_context
,
6952 .event_init
= perf_tp_event_init
,
6953 .add
= perf_trace_add
,
6954 .del
= perf_trace_del
,
6955 .start
= perf_swevent_start
,
6956 .stop
= perf_swevent_stop
,
6957 .read
= perf_swevent_read
,
6960 static inline void perf_tp_register(void)
6962 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
6965 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6970 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6973 filter_str
= strndup_user(arg
, PAGE_SIZE
);
6974 if (IS_ERR(filter_str
))
6975 return PTR_ERR(filter_str
);
6977 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
6983 static void perf_event_free_filter(struct perf_event
*event
)
6985 ftrace_profile_free_filter(event
);
6988 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
6990 struct bpf_prog
*prog
;
6992 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6995 if (event
->tp_event
->prog
)
6998 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
6999 /* bpf programs can only be attached to u/kprobes */
7002 prog
= bpf_prog_get(prog_fd
);
7004 return PTR_ERR(prog
);
7006 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7007 /* valid fd, but invalid bpf program type */
7012 event
->tp_event
->prog
= prog
;
7017 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7019 struct bpf_prog
*prog
;
7021 if (!event
->tp_event
)
7024 prog
= event
->tp_event
->prog
;
7026 event
->tp_event
->prog
= NULL
;
7033 static inline void perf_tp_register(void)
7037 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7042 static void perf_event_free_filter(struct perf_event
*event
)
7046 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7051 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7054 #endif /* CONFIG_EVENT_TRACING */
7056 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7057 void perf_bp_event(struct perf_event
*bp
, void *data
)
7059 struct perf_sample_data sample
;
7060 struct pt_regs
*regs
= data
;
7062 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7064 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7065 perf_swevent_event(bp
, 1, &sample
, regs
);
7070 * hrtimer based swevent callback
7073 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7075 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7076 struct perf_sample_data data
;
7077 struct pt_regs
*regs
;
7078 struct perf_event
*event
;
7081 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7083 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7084 return HRTIMER_NORESTART
;
7086 event
->pmu
->read(event
);
7088 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7089 regs
= get_irq_regs();
7091 if (regs
&& !perf_exclude_event(event
, regs
)) {
7092 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7093 if (__perf_event_overflow(event
, 1, &data
, regs
))
7094 ret
= HRTIMER_NORESTART
;
7097 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7098 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7103 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7105 struct hw_perf_event
*hwc
= &event
->hw
;
7108 if (!is_sampling_event(event
))
7111 period
= local64_read(&hwc
->period_left
);
7116 local64_set(&hwc
->period_left
, 0);
7118 period
= max_t(u64
, 10000, hwc
->sample_period
);
7120 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7121 HRTIMER_MODE_REL_PINNED
);
7124 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7126 struct hw_perf_event
*hwc
= &event
->hw
;
7128 if (is_sampling_event(event
)) {
7129 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7130 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7132 hrtimer_cancel(&hwc
->hrtimer
);
7136 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7138 struct hw_perf_event
*hwc
= &event
->hw
;
7140 if (!is_sampling_event(event
))
7143 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7144 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7147 * Since hrtimers have a fixed rate, we can do a static freq->period
7148 * mapping and avoid the whole period adjust feedback stuff.
7150 if (event
->attr
.freq
) {
7151 long freq
= event
->attr
.sample_freq
;
7153 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7154 hwc
->sample_period
= event
->attr
.sample_period
;
7155 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7156 hwc
->last_period
= hwc
->sample_period
;
7157 event
->attr
.freq
= 0;
7162 * Software event: cpu wall time clock
7165 static void cpu_clock_event_update(struct perf_event
*event
)
7170 now
= local_clock();
7171 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7172 local64_add(now
- prev
, &event
->count
);
7175 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7177 local64_set(&event
->hw
.prev_count
, local_clock());
7178 perf_swevent_start_hrtimer(event
);
7181 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7183 perf_swevent_cancel_hrtimer(event
);
7184 cpu_clock_event_update(event
);
7187 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7189 if (flags
& PERF_EF_START
)
7190 cpu_clock_event_start(event
, flags
);
7191 perf_event_update_userpage(event
);
7196 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7198 cpu_clock_event_stop(event
, flags
);
7201 static void cpu_clock_event_read(struct perf_event
*event
)
7203 cpu_clock_event_update(event
);
7206 static int cpu_clock_event_init(struct perf_event
*event
)
7208 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7211 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7215 * no branch sampling for software events
7217 if (has_branch_stack(event
))
7220 perf_swevent_init_hrtimer(event
);
7225 static struct pmu perf_cpu_clock
= {
7226 .task_ctx_nr
= perf_sw_context
,
7228 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7230 .event_init
= cpu_clock_event_init
,
7231 .add
= cpu_clock_event_add
,
7232 .del
= cpu_clock_event_del
,
7233 .start
= cpu_clock_event_start
,
7234 .stop
= cpu_clock_event_stop
,
7235 .read
= cpu_clock_event_read
,
7239 * Software event: task time clock
7242 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7247 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7249 local64_add(delta
, &event
->count
);
7252 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7254 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7255 perf_swevent_start_hrtimer(event
);
7258 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7260 perf_swevent_cancel_hrtimer(event
);
7261 task_clock_event_update(event
, event
->ctx
->time
);
7264 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7266 if (flags
& PERF_EF_START
)
7267 task_clock_event_start(event
, flags
);
7268 perf_event_update_userpage(event
);
7273 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7275 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7278 static void task_clock_event_read(struct perf_event
*event
)
7280 u64 now
= perf_clock();
7281 u64 delta
= now
- event
->ctx
->timestamp
;
7282 u64 time
= event
->ctx
->time
+ delta
;
7284 task_clock_event_update(event
, time
);
7287 static int task_clock_event_init(struct perf_event
*event
)
7289 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7292 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7296 * no branch sampling for software events
7298 if (has_branch_stack(event
))
7301 perf_swevent_init_hrtimer(event
);
7306 static struct pmu perf_task_clock
= {
7307 .task_ctx_nr
= perf_sw_context
,
7309 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7311 .event_init
= task_clock_event_init
,
7312 .add
= task_clock_event_add
,
7313 .del
= task_clock_event_del
,
7314 .start
= task_clock_event_start
,
7315 .stop
= task_clock_event_stop
,
7316 .read
= task_clock_event_read
,
7319 static void perf_pmu_nop_void(struct pmu
*pmu
)
7323 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7327 static int perf_pmu_nop_int(struct pmu
*pmu
)
7332 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7334 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7336 __this_cpu_write(nop_txn_flags
, flags
);
7338 if (flags
& ~PERF_PMU_TXN_ADD
)
7341 perf_pmu_disable(pmu
);
7344 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7346 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7348 __this_cpu_write(nop_txn_flags
, 0);
7350 if (flags
& ~PERF_PMU_TXN_ADD
)
7353 perf_pmu_enable(pmu
);
7357 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7359 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7361 __this_cpu_write(nop_txn_flags
, 0);
7363 if (flags
& ~PERF_PMU_TXN_ADD
)
7366 perf_pmu_enable(pmu
);
7369 static int perf_event_idx_default(struct perf_event
*event
)
7375 * Ensures all contexts with the same task_ctx_nr have the same
7376 * pmu_cpu_context too.
7378 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7385 list_for_each_entry(pmu
, &pmus
, entry
) {
7386 if (pmu
->task_ctx_nr
== ctxn
)
7387 return pmu
->pmu_cpu_context
;
7393 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7397 for_each_possible_cpu(cpu
) {
7398 struct perf_cpu_context
*cpuctx
;
7400 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7402 if (cpuctx
->unique_pmu
== old_pmu
)
7403 cpuctx
->unique_pmu
= pmu
;
7407 static void free_pmu_context(struct pmu
*pmu
)
7411 mutex_lock(&pmus_lock
);
7413 * Like a real lame refcount.
7415 list_for_each_entry(i
, &pmus
, entry
) {
7416 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7417 update_pmu_context(i
, pmu
);
7422 free_percpu(pmu
->pmu_cpu_context
);
7424 mutex_unlock(&pmus_lock
);
7426 static struct idr pmu_idr
;
7429 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7431 struct pmu
*pmu
= dev_get_drvdata(dev
);
7433 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7435 static DEVICE_ATTR_RO(type
);
7438 perf_event_mux_interval_ms_show(struct device
*dev
,
7439 struct device_attribute
*attr
,
7442 struct pmu
*pmu
= dev_get_drvdata(dev
);
7444 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7447 static DEFINE_MUTEX(mux_interval_mutex
);
7450 perf_event_mux_interval_ms_store(struct device
*dev
,
7451 struct device_attribute
*attr
,
7452 const char *buf
, size_t count
)
7454 struct pmu
*pmu
= dev_get_drvdata(dev
);
7455 int timer
, cpu
, ret
;
7457 ret
= kstrtoint(buf
, 0, &timer
);
7464 /* same value, noting to do */
7465 if (timer
== pmu
->hrtimer_interval_ms
)
7468 mutex_lock(&mux_interval_mutex
);
7469 pmu
->hrtimer_interval_ms
= timer
;
7471 /* update all cpuctx for this PMU */
7473 for_each_online_cpu(cpu
) {
7474 struct perf_cpu_context
*cpuctx
;
7475 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7476 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7478 cpu_function_call(cpu
,
7479 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7482 mutex_unlock(&mux_interval_mutex
);
7486 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7488 static struct attribute
*pmu_dev_attrs
[] = {
7489 &dev_attr_type
.attr
,
7490 &dev_attr_perf_event_mux_interval_ms
.attr
,
7493 ATTRIBUTE_GROUPS(pmu_dev
);
7495 static int pmu_bus_running
;
7496 static struct bus_type pmu_bus
= {
7497 .name
= "event_source",
7498 .dev_groups
= pmu_dev_groups
,
7501 static void pmu_dev_release(struct device
*dev
)
7506 static int pmu_dev_alloc(struct pmu
*pmu
)
7510 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7514 pmu
->dev
->groups
= pmu
->attr_groups
;
7515 device_initialize(pmu
->dev
);
7516 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7520 dev_set_drvdata(pmu
->dev
, pmu
);
7521 pmu
->dev
->bus
= &pmu_bus
;
7522 pmu
->dev
->release
= pmu_dev_release
;
7523 ret
= device_add(pmu
->dev
);
7531 put_device(pmu
->dev
);
7535 static struct lock_class_key cpuctx_mutex
;
7536 static struct lock_class_key cpuctx_lock
;
7538 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7542 mutex_lock(&pmus_lock
);
7544 pmu
->pmu_disable_count
= alloc_percpu(int);
7545 if (!pmu
->pmu_disable_count
)
7554 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7562 if (pmu_bus_running
) {
7563 ret
= pmu_dev_alloc(pmu
);
7569 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7570 if (pmu
->pmu_cpu_context
)
7571 goto got_cpu_context
;
7574 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7575 if (!pmu
->pmu_cpu_context
)
7578 for_each_possible_cpu(cpu
) {
7579 struct perf_cpu_context
*cpuctx
;
7581 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7582 __perf_event_init_context(&cpuctx
->ctx
);
7583 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7584 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7585 cpuctx
->ctx
.pmu
= pmu
;
7587 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7589 cpuctx
->unique_pmu
= pmu
;
7593 if (!pmu
->start_txn
) {
7594 if (pmu
->pmu_enable
) {
7596 * If we have pmu_enable/pmu_disable calls, install
7597 * transaction stubs that use that to try and batch
7598 * hardware accesses.
7600 pmu
->start_txn
= perf_pmu_start_txn
;
7601 pmu
->commit_txn
= perf_pmu_commit_txn
;
7602 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7604 pmu
->start_txn
= perf_pmu_nop_txn
;
7605 pmu
->commit_txn
= perf_pmu_nop_int
;
7606 pmu
->cancel_txn
= perf_pmu_nop_void
;
7610 if (!pmu
->pmu_enable
) {
7611 pmu
->pmu_enable
= perf_pmu_nop_void
;
7612 pmu
->pmu_disable
= perf_pmu_nop_void
;
7615 if (!pmu
->event_idx
)
7616 pmu
->event_idx
= perf_event_idx_default
;
7618 list_add_rcu(&pmu
->entry
, &pmus
);
7619 atomic_set(&pmu
->exclusive_cnt
, 0);
7622 mutex_unlock(&pmus_lock
);
7627 device_del(pmu
->dev
);
7628 put_device(pmu
->dev
);
7631 if (pmu
->type
>= PERF_TYPE_MAX
)
7632 idr_remove(&pmu_idr
, pmu
->type
);
7635 free_percpu(pmu
->pmu_disable_count
);
7638 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7640 void perf_pmu_unregister(struct pmu
*pmu
)
7642 mutex_lock(&pmus_lock
);
7643 list_del_rcu(&pmu
->entry
);
7644 mutex_unlock(&pmus_lock
);
7647 * We dereference the pmu list under both SRCU and regular RCU, so
7648 * synchronize against both of those.
7650 synchronize_srcu(&pmus_srcu
);
7653 free_percpu(pmu
->pmu_disable_count
);
7654 if (pmu
->type
>= PERF_TYPE_MAX
)
7655 idr_remove(&pmu_idr
, pmu
->type
);
7656 device_del(pmu
->dev
);
7657 put_device(pmu
->dev
);
7658 free_pmu_context(pmu
);
7660 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7662 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7664 struct perf_event_context
*ctx
= NULL
;
7667 if (!try_module_get(pmu
->module
))
7670 if (event
->group_leader
!= event
) {
7672 * This ctx->mutex can nest when we're called through
7673 * inheritance. See the perf_event_ctx_lock_nested() comment.
7675 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7676 SINGLE_DEPTH_NESTING
);
7681 ret
= pmu
->event_init(event
);
7684 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7687 module_put(pmu
->module
);
7692 static struct pmu
*perf_init_event(struct perf_event
*event
)
7694 struct pmu
*pmu
= NULL
;
7698 idx
= srcu_read_lock(&pmus_srcu
);
7701 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7704 ret
= perf_try_init_event(pmu
, event
);
7710 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7711 ret
= perf_try_init_event(pmu
, event
);
7715 if (ret
!= -ENOENT
) {
7720 pmu
= ERR_PTR(-ENOENT
);
7722 srcu_read_unlock(&pmus_srcu
, idx
);
7727 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7732 if (is_cgroup_event(event
))
7733 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7736 static void account_event(struct perf_event
*event
)
7743 if (event
->attach_state
& PERF_ATTACH_TASK
)
7745 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7746 atomic_inc(&nr_mmap_events
);
7747 if (event
->attr
.comm
)
7748 atomic_inc(&nr_comm_events
);
7749 if (event
->attr
.task
)
7750 atomic_inc(&nr_task_events
);
7751 if (event
->attr
.freq
) {
7752 if (atomic_inc_return(&nr_freq_events
) == 1)
7753 tick_nohz_full_kick_all();
7755 if (event
->attr
.context_switch
) {
7756 atomic_inc(&nr_switch_events
);
7759 if (has_branch_stack(event
))
7761 if (is_cgroup_event(event
))
7765 static_key_slow_inc(&perf_sched_events
.key
);
7767 account_event_cpu(event
, event
->cpu
);
7771 * Allocate and initialize a event structure
7773 static struct perf_event
*
7774 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7775 struct task_struct
*task
,
7776 struct perf_event
*group_leader
,
7777 struct perf_event
*parent_event
,
7778 perf_overflow_handler_t overflow_handler
,
7779 void *context
, int cgroup_fd
)
7782 struct perf_event
*event
;
7783 struct hw_perf_event
*hwc
;
7786 if ((unsigned)cpu
>= nr_cpu_ids
) {
7787 if (!task
|| cpu
!= -1)
7788 return ERR_PTR(-EINVAL
);
7791 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7793 return ERR_PTR(-ENOMEM
);
7796 * Single events are their own group leaders, with an
7797 * empty sibling list:
7800 group_leader
= event
;
7802 mutex_init(&event
->child_mutex
);
7803 INIT_LIST_HEAD(&event
->child_list
);
7805 INIT_LIST_HEAD(&event
->group_entry
);
7806 INIT_LIST_HEAD(&event
->event_entry
);
7807 INIT_LIST_HEAD(&event
->sibling_list
);
7808 INIT_LIST_HEAD(&event
->rb_entry
);
7809 INIT_LIST_HEAD(&event
->active_entry
);
7810 INIT_HLIST_NODE(&event
->hlist_entry
);
7813 init_waitqueue_head(&event
->waitq
);
7814 init_irq_work(&event
->pending
, perf_pending_event
);
7816 mutex_init(&event
->mmap_mutex
);
7818 atomic_long_set(&event
->refcount
, 1);
7820 event
->attr
= *attr
;
7821 event
->group_leader
= group_leader
;
7825 event
->parent
= parent_event
;
7827 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7828 event
->id
= atomic64_inc_return(&perf_event_id
);
7830 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7833 event
->attach_state
= PERF_ATTACH_TASK
;
7835 * XXX pmu::event_init needs to know what task to account to
7836 * and we cannot use the ctx information because we need the
7837 * pmu before we get a ctx.
7839 event
->hw
.target
= task
;
7842 event
->clock
= &local_clock
;
7844 event
->clock
= parent_event
->clock
;
7846 if (!overflow_handler
&& parent_event
) {
7847 overflow_handler
= parent_event
->overflow_handler
;
7848 context
= parent_event
->overflow_handler_context
;
7851 event
->overflow_handler
= overflow_handler
;
7852 event
->overflow_handler_context
= context
;
7854 perf_event__state_init(event
);
7859 hwc
->sample_period
= attr
->sample_period
;
7860 if (attr
->freq
&& attr
->sample_freq
)
7861 hwc
->sample_period
= 1;
7862 hwc
->last_period
= hwc
->sample_period
;
7864 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7867 * we currently do not support PERF_FORMAT_GROUP on inherited events
7869 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7872 if (!has_branch_stack(event
))
7873 event
->attr
.branch_sample_type
= 0;
7875 if (cgroup_fd
!= -1) {
7876 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7881 pmu
= perf_init_event(event
);
7884 else if (IS_ERR(pmu
)) {
7889 err
= exclusive_event_init(event
);
7893 if (!event
->parent
) {
7894 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7895 err
= get_callchain_buffers();
7904 exclusive_event_destroy(event
);
7908 event
->destroy(event
);
7909 module_put(pmu
->module
);
7911 if (is_cgroup_event(event
))
7912 perf_detach_cgroup(event
);
7914 put_pid_ns(event
->ns
);
7917 return ERR_PTR(err
);
7920 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
7921 struct perf_event_attr
*attr
)
7926 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
7930 * zero the full structure, so that a short copy will be nice.
7932 memset(attr
, 0, sizeof(*attr
));
7934 ret
= get_user(size
, &uattr
->size
);
7938 if (size
> PAGE_SIZE
) /* silly large */
7941 if (!size
) /* abi compat */
7942 size
= PERF_ATTR_SIZE_VER0
;
7944 if (size
< PERF_ATTR_SIZE_VER0
)
7948 * If we're handed a bigger struct than we know of,
7949 * ensure all the unknown bits are 0 - i.e. new
7950 * user-space does not rely on any kernel feature
7951 * extensions we dont know about yet.
7953 if (size
> sizeof(*attr
)) {
7954 unsigned char __user
*addr
;
7955 unsigned char __user
*end
;
7958 addr
= (void __user
*)uattr
+ sizeof(*attr
);
7959 end
= (void __user
*)uattr
+ size
;
7961 for (; addr
< end
; addr
++) {
7962 ret
= get_user(val
, addr
);
7968 size
= sizeof(*attr
);
7971 ret
= copy_from_user(attr
, uattr
, size
);
7975 if (attr
->__reserved_1
)
7978 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
7981 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
7984 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
7985 u64 mask
= attr
->branch_sample_type
;
7987 /* only using defined bits */
7988 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
7991 /* at least one branch bit must be set */
7992 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
7995 /* propagate priv level, when not set for branch */
7996 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
7998 /* exclude_kernel checked on syscall entry */
7999 if (!attr
->exclude_kernel
)
8000 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8002 if (!attr
->exclude_user
)
8003 mask
|= PERF_SAMPLE_BRANCH_USER
;
8005 if (!attr
->exclude_hv
)
8006 mask
|= PERF_SAMPLE_BRANCH_HV
;
8008 * adjust user setting (for HW filter setup)
8010 attr
->branch_sample_type
= mask
;
8012 /* privileged levels capture (kernel, hv): check permissions */
8013 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8014 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8018 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8019 ret
= perf_reg_validate(attr
->sample_regs_user
);
8024 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8025 if (!arch_perf_have_user_stack_dump())
8029 * We have __u32 type for the size, but so far
8030 * we can only use __u16 as maximum due to the
8031 * __u16 sample size limit.
8033 if (attr
->sample_stack_user
>= USHRT_MAX
)
8035 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8039 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8040 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8045 put_user(sizeof(*attr
), &uattr
->size
);
8051 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8053 struct ring_buffer
*rb
= NULL
;
8059 /* don't allow circular references */
8060 if (event
== output_event
)
8064 * Don't allow cross-cpu buffers
8066 if (output_event
->cpu
!= event
->cpu
)
8070 * If its not a per-cpu rb, it must be the same task.
8072 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8076 * Mixing clocks in the same buffer is trouble you don't need.
8078 if (output_event
->clock
!= event
->clock
)
8082 * If both events generate aux data, they must be on the same PMU
8084 if (has_aux(event
) && has_aux(output_event
) &&
8085 event
->pmu
!= output_event
->pmu
)
8089 mutex_lock(&event
->mmap_mutex
);
8090 /* Can't redirect output if we've got an active mmap() */
8091 if (atomic_read(&event
->mmap_count
))
8095 /* get the rb we want to redirect to */
8096 rb
= ring_buffer_get(output_event
);
8101 ring_buffer_attach(event
, rb
);
8105 mutex_unlock(&event
->mmap_mutex
);
8111 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8117 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8120 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8122 bool nmi_safe
= false;
8125 case CLOCK_MONOTONIC
:
8126 event
->clock
= &ktime_get_mono_fast_ns
;
8130 case CLOCK_MONOTONIC_RAW
:
8131 event
->clock
= &ktime_get_raw_fast_ns
;
8135 case CLOCK_REALTIME
:
8136 event
->clock
= &ktime_get_real_ns
;
8139 case CLOCK_BOOTTIME
:
8140 event
->clock
= &ktime_get_boot_ns
;
8144 event
->clock
= &ktime_get_tai_ns
;
8151 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8158 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8160 * @attr_uptr: event_id type attributes for monitoring/sampling
8163 * @group_fd: group leader event fd
8165 SYSCALL_DEFINE5(perf_event_open
,
8166 struct perf_event_attr __user
*, attr_uptr
,
8167 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8169 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8170 struct perf_event
*event
, *sibling
;
8171 struct perf_event_attr attr
;
8172 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8173 struct file
*event_file
= NULL
;
8174 struct fd group
= {NULL
, 0};
8175 struct task_struct
*task
= NULL
;
8180 int f_flags
= O_RDWR
;
8183 /* for future expandability... */
8184 if (flags
& ~PERF_FLAG_ALL
)
8187 err
= perf_copy_attr(attr_uptr
, &attr
);
8191 if (!attr
.exclude_kernel
) {
8192 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8197 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8200 if (attr
.sample_period
& (1ULL << 63))
8205 * In cgroup mode, the pid argument is used to pass the fd
8206 * opened to the cgroup directory in cgroupfs. The cpu argument
8207 * designates the cpu on which to monitor threads from that
8210 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8213 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8214 f_flags
|= O_CLOEXEC
;
8216 event_fd
= get_unused_fd_flags(f_flags
);
8220 if (group_fd
!= -1) {
8221 err
= perf_fget_light(group_fd
, &group
);
8224 group_leader
= group
.file
->private_data
;
8225 if (flags
& PERF_FLAG_FD_OUTPUT
)
8226 output_event
= group_leader
;
8227 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8228 group_leader
= NULL
;
8231 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8232 task
= find_lively_task_by_vpid(pid
);
8234 err
= PTR_ERR(task
);
8239 if (task
&& group_leader
&&
8240 group_leader
->attr
.inherit
!= attr
.inherit
) {
8247 if (flags
& PERF_FLAG_PID_CGROUP
)
8250 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8251 NULL
, NULL
, cgroup_fd
);
8252 if (IS_ERR(event
)) {
8253 err
= PTR_ERR(event
);
8257 if (is_sampling_event(event
)) {
8258 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8264 account_event(event
);
8267 * Special case software events and allow them to be part of
8268 * any hardware group.
8272 if (attr
.use_clockid
) {
8273 err
= perf_event_set_clock(event
, attr
.clockid
);
8279 (is_software_event(event
) != is_software_event(group_leader
))) {
8280 if (is_software_event(event
)) {
8282 * If event and group_leader are not both a software
8283 * event, and event is, then group leader is not.
8285 * Allow the addition of software events to !software
8286 * groups, this is safe because software events never
8289 pmu
= group_leader
->pmu
;
8290 } else if (is_software_event(group_leader
) &&
8291 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8293 * In case the group is a pure software group, and we
8294 * try to add a hardware event, move the whole group to
8295 * the hardware context.
8302 * Get the target context (task or percpu):
8304 ctx
= find_get_context(pmu
, task
, event
);
8310 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8316 put_task_struct(task
);
8321 * Look up the group leader (we will attach this event to it):
8327 * Do not allow a recursive hierarchy (this new sibling
8328 * becoming part of another group-sibling):
8330 if (group_leader
->group_leader
!= group_leader
)
8333 /* All events in a group should have the same clock */
8334 if (group_leader
->clock
!= event
->clock
)
8338 * Do not allow to attach to a group in a different
8339 * task or CPU context:
8343 * Make sure we're both on the same task, or both
8346 if (group_leader
->ctx
->task
!= ctx
->task
)
8350 * Make sure we're both events for the same CPU;
8351 * grouping events for different CPUs is broken; since
8352 * you can never concurrently schedule them anyhow.
8354 if (group_leader
->cpu
!= event
->cpu
)
8357 if (group_leader
->ctx
!= ctx
)
8362 * Only a group leader can be exclusive or pinned
8364 if (attr
.exclusive
|| attr
.pinned
)
8369 err
= perf_event_set_output(event
, output_event
);
8374 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8376 if (IS_ERR(event_file
)) {
8377 err
= PTR_ERR(event_file
);
8382 gctx
= group_leader
->ctx
;
8383 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8385 mutex_lock(&ctx
->mutex
);
8388 if (!perf_event_validate_size(event
)) {
8394 * Must be under the same ctx::mutex as perf_install_in_context(),
8395 * because we need to serialize with concurrent event creation.
8397 if (!exclusive_event_installable(event
, ctx
)) {
8398 /* exclusive and group stuff are assumed mutually exclusive */
8399 WARN_ON_ONCE(move_group
);
8405 WARN_ON_ONCE(ctx
->parent_ctx
);
8409 * See perf_event_ctx_lock() for comments on the details
8410 * of swizzling perf_event::ctx.
8412 perf_remove_from_context(group_leader
, false);
8414 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8416 perf_remove_from_context(sibling
, false);
8421 * Wait for everybody to stop referencing the events through
8422 * the old lists, before installing it on new lists.
8427 * Install the group siblings before the group leader.
8429 * Because a group leader will try and install the entire group
8430 * (through the sibling list, which is still in-tact), we can
8431 * end up with siblings installed in the wrong context.
8433 * By installing siblings first we NO-OP because they're not
8434 * reachable through the group lists.
8436 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8438 perf_event__state_init(sibling
);
8439 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8444 * Removing from the context ends up with disabled
8445 * event. What we want here is event in the initial
8446 * startup state, ready to be add into new context.
8448 perf_event__state_init(group_leader
);
8449 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8453 * Now that all events are installed in @ctx, nothing
8454 * references @gctx anymore, so drop the last reference we have
8461 * Precalculate sample_data sizes; do while holding ctx::mutex such
8462 * that we're serialized against further additions and before
8463 * perf_install_in_context() which is the point the event is active and
8464 * can use these values.
8466 perf_event__header_size(event
);
8467 perf_event__id_header_size(event
);
8469 perf_install_in_context(ctx
, event
, event
->cpu
);
8470 perf_unpin_context(ctx
);
8473 mutex_unlock(&gctx
->mutex
);
8474 mutex_unlock(&ctx
->mutex
);
8478 event
->owner
= current
;
8480 mutex_lock(¤t
->perf_event_mutex
);
8481 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8482 mutex_unlock(¤t
->perf_event_mutex
);
8485 * Drop the reference on the group_event after placing the
8486 * new event on the sibling_list. This ensures destruction
8487 * of the group leader will find the pointer to itself in
8488 * perf_group_detach().
8491 fd_install(event_fd
, event_file
);
8496 mutex_unlock(&gctx
->mutex
);
8497 mutex_unlock(&ctx
->mutex
);
8501 perf_unpin_context(ctx
);
8509 put_task_struct(task
);
8513 put_unused_fd(event_fd
);
8518 * perf_event_create_kernel_counter
8520 * @attr: attributes of the counter to create
8521 * @cpu: cpu in which the counter is bound
8522 * @task: task to profile (NULL for percpu)
8525 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8526 struct task_struct
*task
,
8527 perf_overflow_handler_t overflow_handler
,
8530 struct perf_event_context
*ctx
;
8531 struct perf_event
*event
;
8535 * Get the target context (task or percpu):
8538 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8539 overflow_handler
, context
, -1);
8540 if (IS_ERR(event
)) {
8541 err
= PTR_ERR(event
);
8545 /* Mark owner so we could distinguish it from user events. */
8546 event
->owner
= EVENT_OWNER_KERNEL
;
8548 account_event(event
);
8550 ctx
= find_get_context(event
->pmu
, task
, event
);
8556 WARN_ON_ONCE(ctx
->parent_ctx
);
8557 mutex_lock(&ctx
->mutex
);
8558 if (!exclusive_event_installable(event
, ctx
)) {
8559 mutex_unlock(&ctx
->mutex
);
8560 perf_unpin_context(ctx
);
8566 perf_install_in_context(ctx
, event
, cpu
);
8567 perf_unpin_context(ctx
);
8568 mutex_unlock(&ctx
->mutex
);
8575 return ERR_PTR(err
);
8577 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8579 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8581 struct perf_event_context
*src_ctx
;
8582 struct perf_event_context
*dst_ctx
;
8583 struct perf_event
*event
, *tmp
;
8586 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8587 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8590 * See perf_event_ctx_lock() for comments on the details
8591 * of swizzling perf_event::ctx.
8593 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8594 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8596 perf_remove_from_context(event
, false);
8597 unaccount_event_cpu(event
, src_cpu
);
8599 list_add(&event
->migrate_entry
, &events
);
8603 * Wait for the events to quiesce before re-instating them.
8608 * Re-instate events in 2 passes.
8610 * Skip over group leaders and only install siblings on this first
8611 * pass, siblings will not get enabled without a leader, however a
8612 * leader will enable its siblings, even if those are still on the old
8615 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8616 if (event
->group_leader
== event
)
8619 list_del(&event
->migrate_entry
);
8620 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8621 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8622 account_event_cpu(event
, dst_cpu
);
8623 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8628 * Once all the siblings are setup properly, install the group leaders
8631 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8632 list_del(&event
->migrate_entry
);
8633 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8634 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8635 account_event_cpu(event
, dst_cpu
);
8636 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8639 mutex_unlock(&dst_ctx
->mutex
);
8640 mutex_unlock(&src_ctx
->mutex
);
8642 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8644 static void sync_child_event(struct perf_event
*child_event
,
8645 struct task_struct
*child
)
8647 struct perf_event
*parent_event
= child_event
->parent
;
8650 if (child_event
->attr
.inherit_stat
)
8651 perf_event_read_event(child_event
, child
);
8653 child_val
= perf_event_count(child_event
);
8656 * Add back the child's count to the parent's count:
8658 atomic64_add(child_val
, &parent_event
->child_count
);
8659 atomic64_add(child_event
->total_time_enabled
,
8660 &parent_event
->child_total_time_enabled
);
8661 atomic64_add(child_event
->total_time_running
,
8662 &parent_event
->child_total_time_running
);
8665 * Remove this event from the parent's list
8667 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8668 mutex_lock(&parent_event
->child_mutex
);
8669 list_del_init(&child_event
->child_list
);
8670 mutex_unlock(&parent_event
->child_mutex
);
8673 * Make sure user/parent get notified, that we just
8676 perf_event_wakeup(parent_event
);
8679 * Release the parent event, if this was the last
8682 put_event(parent_event
);
8686 __perf_event_exit_task(struct perf_event
*child_event
,
8687 struct perf_event_context
*child_ctx
,
8688 struct task_struct
*child
)
8691 * Do not destroy the 'original' grouping; because of the context
8692 * switch optimization the original events could've ended up in a
8693 * random child task.
8695 * If we were to destroy the original group, all group related
8696 * operations would cease to function properly after this random
8699 * Do destroy all inherited groups, we don't care about those
8700 * and being thorough is better.
8702 perf_remove_from_context(child_event
, !!child_event
->parent
);
8705 * It can happen that the parent exits first, and has events
8706 * that are still around due to the child reference. These
8707 * events need to be zapped.
8709 if (child_event
->parent
) {
8710 sync_child_event(child_event
, child
);
8711 free_event(child_event
);
8713 child_event
->state
= PERF_EVENT_STATE_EXIT
;
8714 perf_event_wakeup(child_event
);
8718 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8720 struct perf_event
*child_event
, *next
;
8721 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8722 unsigned long flags
;
8724 if (likely(!child
->perf_event_ctxp
[ctxn
]))
8727 local_irq_save(flags
);
8729 * We can't reschedule here because interrupts are disabled,
8730 * and either child is current or it is a task that can't be
8731 * scheduled, so we are now safe from rescheduling changing
8734 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
8737 * Take the context lock here so that if find_get_context is
8738 * reading child->perf_event_ctxp, we wait until it has
8739 * incremented the context's refcount before we do put_ctx below.
8741 raw_spin_lock(&child_ctx
->lock
);
8742 task_ctx_sched_out(__get_cpu_context(child_ctx
), child_ctx
);
8743 child
->perf_event_ctxp
[ctxn
] = NULL
;
8746 * If this context is a clone; unclone it so it can't get
8747 * swapped to another process while we're removing all
8748 * the events from it.
8750 clone_ctx
= unclone_ctx(child_ctx
);
8751 update_context_time(child_ctx
);
8752 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8758 * Report the task dead after unscheduling the events so that we
8759 * won't get any samples after PERF_RECORD_EXIT. We can however still
8760 * get a few PERF_RECORD_READ events.
8762 perf_event_task(child
, child_ctx
, 0);
8765 * We can recurse on the same lock type through:
8767 * __perf_event_exit_task()
8768 * sync_child_event()
8770 * mutex_lock(&ctx->mutex)
8772 * But since its the parent context it won't be the same instance.
8774 mutex_lock(&child_ctx
->mutex
);
8776 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8777 __perf_event_exit_task(child_event
, child_ctx
, child
);
8779 mutex_unlock(&child_ctx
->mutex
);
8785 * When a child task exits, feed back event values to parent events.
8787 void perf_event_exit_task(struct task_struct
*child
)
8789 struct perf_event
*event
, *tmp
;
8792 mutex_lock(&child
->perf_event_mutex
);
8793 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8795 list_del_init(&event
->owner_entry
);
8798 * Ensure the list deletion is visible before we clear
8799 * the owner, closes a race against perf_release() where
8800 * we need to serialize on the owner->perf_event_mutex.
8803 event
->owner
= NULL
;
8805 mutex_unlock(&child
->perf_event_mutex
);
8807 for_each_task_context_nr(ctxn
)
8808 perf_event_exit_task_context(child
, ctxn
);
8811 * The perf_event_exit_task_context calls perf_event_task
8812 * with child's task_ctx, which generates EXIT events for
8813 * child contexts and sets child->perf_event_ctxp[] to NULL.
8814 * At this point we need to send EXIT events to cpu contexts.
8816 perf_event_task(child
, NULL
, 0);
8819 static void perf_free_event(struct perf_event
*event
,
8820 struct perf_event_context
*ctx
)
8822 struct perf_event
*parent
= event
->parent
;
8824 if (WARN_ON_ONCE(!parent
))
8827 mutex_lock(&parent
->child_mutex
);
8828 list_del_init(&event
->child_list
);
8829 mutex_unlock(&parent
->child_mutex
);
8833 raw_spin_lock_irq(&ctx
->lock
);
8834 perf_group_detach(event
);
8835 list_del_event(event
, ctx
);
8836 raw_spin_unlock_irq(&ctx
->lock
);
8841 * Free an unexposed, unused context as created by inheritance by
8842 * perf_event_init_task below, used by fork() in case of fail.
8844 * Not all locks are strictly required, but take them anyway to be nice and
8845 * help out with the lockdep assertions.
8847 void perf_event_free_task(struct task_struct
*task
)
8849 struct perf_event_context
*ctx
;
8850 struct perf_event
*event
, *tmp
;
8853 for_each_task_context_nr(ctxn
) {
8854 ctx
= task
->perf_event_ctxp
[ctxn
];
8858 mutex_lock(&ctx
->mutex
);
8860 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8862 perf_free_event(event
, ctx
);
8864 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8866 perf_free_event(event
, ctx
);
8868 if (!list_empty(&ctx
->pinned_groups
) ||
8869 !list_empty(&ctx
->flexible_groups
))
8872 mutex_unlock(&ctx
->mutex
);
8878 void perf_event_delayed_put(struct task_struct
*task
)
8882 for_each_task_context_nr(ctxn
)
8883 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8886 struct perf_event
*perf_event_get(unsigned int fd
)
8890 struct perf_event
*event
;
8892 err
= perf_fget_light(fd
, &f
);
8894 return ERR_PTR(err
);
8896 event
= f
.file
->private_data
;
8897 atomic_long_inc(&event
->refcount
);
8903 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
8906 return ERR_PTR(-EINVAL
);
8908 return &event
->attr
;
8912 * inherit a event from parent task to child task:
8914 static struct perf_event
*
8915 inherit_event(struct perf_event
*parent_event
,
8916 struct task_struct
*parent
,
8917 struct perf_event_context
*parent_ctx
,
8918 struct task_struct
*child
,
8919 struct perf_event
*group_leader
,
8920 struct perf_event_context
*child_ctx
)
8922 enum perf_event_active_state parent_state
= parent_event
->state
;
8923 struct perf_event
*child_event
;
8924 unsigned long flags
;
8927 * Instead of creating recursive hierarchies of events,
8928 * we link inherited events back to the original parent,
8929 * which has a filp for sure, which we use as the reference
8932 if (parent_event
->parent
)
8933 parent_event
= parent_event
->parent
;
8935 child_event
= perf_event_alloc(&parent_event
->attr
,
8938 group_leader
, parent_event
,
8940 if (IS_ERR(child_event
))
8943 if (is_orphaned_event(parent_event
) ||
8944 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
8945 free_event(child_event
);
8952 * Make the child state follow the state of the parent event,
8953 * not its attr.disabled bit. We hold the parent's mutex,
8954 * so we won't race with perf_event_{en, dis}able_family.
8956 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
8957 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
8959 child_event
->state
= PERF_EVENT_STATE_OFF
;
8961 if (parent_event
->attr
.freq
) {
8962 u64 sample_period
= parent_event
->hw
.sample_period
;
8963 struct hw_perf_event
*hwc
= &child_event
->hw
;
8965 hwc
->sample_period
= sample_period
;
8966 hwc
->last_period
= sample_period
;
8968 local64_set(&hwc
->period_left
, sample_period
);
8971 child_event
->ctx
= child_ctx
;
8972 child_event
->overflow_handler
= parent_event
->overflow_handler
;
8973 child_event
->overflow_handler_context
8974 = parent_event
->overflow_handler_context
;
8977 * Precalculate sample_data sizes
8979 perf_event__header_size(child_event
);
8980 perf_event__id_header_size(child_event
);
8983 * Link it up in the child's context:
8985 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
8986 add_event_to_ctx(child_event
, child_ctx
);
8987 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8990 * Link this into the parent event's child list
8992 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8993 mutex_lock(&parent_event
->child_mutex
);
8994 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
8995 mutex_unlock(&parent_event
->child_mutex
);
9000 static int inherit_group(struct perf_event
*parent_event
,
9001 struct task_struct
*parent
,
9002 struct perf_event_context
*parent_ctx
,
9003 struct task_struct
*child
,
9004 struct perf_event_context
*child_ctx
)
9006 struct perf_event
*leader
;
9007 struct perf_event
*sub
;
9008 struct perf_event
*child_ctr
;
9010 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9011 child
, NULL
, child_ctx
);
9013 return PTR_ERR(leader
);
9014 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9015 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9016 child
, leader
, child_ctx
);
9017 if (IS_ERR(child_ctr
))
9018 return PTR_ERR(child_ctr
);
9024 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9025 struct perf_event_context
*parent_ctx
,
9026 struct task_struct
*child
, int ctxn
,
9030 struct perf_event_context
*child_ctx
;
9032 if (!event
->attr
.inherit
) {
9037 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9040 * This is executed from the parent task context, so
9041 * inherit events that have been marked for cloning.
9042 * First allocate and initialize a context for the
9046 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9050 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9053 ret
= inherit_group(event
, parent
, parent_ctx
,
9063 * Initialize the perf_event context in task_struct
9065 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9067 struct perf_event_context
*child_ctx
, *parent_ctx
;
9068 struct perf_event_context
*cloned_ctx
;
9069 struct perf_event
*event
;
9070 struct task_struct
*parent
= current
;
9071 int inherited_all
= 1;
9072 unsigned long flags
;
9075 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9079 * If the parent's context is a clone, pin it so it won't get
9082 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9087 * No need to check if parent_ctx != NULL here; since we saw
9088 * it non-NULL earlier, the only reason for it to become NULL
9089 * is if we exit, and since we're currently in the middle of
9090 * a fork we can't be exiting at the same time.
9094 * Lock the parent list. No need to lock the child - not PID
9095 * hashed yet and not running, so nobody can access it.
9097 mutex_lock(&parent_ctx
->mutex
);
9100 * We dont have to disable NMIs - we are only looking at
9101 * the list, not manipulating it:
9103 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9104 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9105 child
, ctxn
, &inherited_all
);
9111 * We can't hold ctx->lock when iterating the ->flexible_group list due
9112 * to allocations, but we need to prevent rotation because
9113 * rotate_ctx() will change the list from interrupt context.
9115 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9116 parent_ctx
->rotate_disable
= 1;
9117 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9119 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9120 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9121 child
, ctxn
, &inherited_all
);
9126 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9127 parent_ctx
->rotate_disable
= 0;
9129 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9131 if (child_ctx
&& inherited_all
) {
9133 * Mark the child context as a clone of the parent
9134 * context, or of whatever the parent is a clone of.
9136 * Note that if the parent is a clone, the holding of
9137 * parent_ctx->lock avoids it from being uncloned.
9139 cloned_ctx
= parent_ctx
->parent_ctx
;
9141 child_ctx
->parent_ctx
= cloned_ctx
;
9142 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9144 child_ctx
->parent_ctx
= parent_ctx
;
9145 child_ctx
->parent_gen
= parent_ctx
->generation
;
9147 get_ctx(child_ctx
->parent_ctx
);
9150 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9151 mutex_unlock(&parent_ctx
->mutex
);
9153 perf_unpin_context(parent_ctx
);
9154 put_ctx(parent_ctx
);
9160 * Initialize the perf_event context in task_struct
9162 int perf_event_init_task(struct task_struct
*child
)
9166 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9167 mutex_init(&child
->perf_event_mutex
);
9168 INIT_LIST_HEAD(&child
->perf_event_list
);
9170 for_each_task_context_nr(ctxn
) {
9171 ret
= perf_event_init_context(child
, ctxn
);
9173 perf_event_free_task(child
);
9181 static void __init
perf_event_init_all_cpus(void)
9183 struct swevent_htable
*swhash
;
9186 for_each_possible_cpu(cpu
) {
9187 swhash
= &per_cpu(swevent_htable
, cpu
);
9188 mutex_init(&swhash
->hlist_mutex
);
9189 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9193 static void perf_event_init_cpu(int cpu
)
9195 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9197 mutex_lock(&swhash
->hlist_mutex
);
9198 if (swhash
->hlist_refcount
> 0) {
9199 struct swevent_hlist
*hlist
;
9201 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9203 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9205 mutex_unlock(&swhash
->hlist_mutex
);
9208 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9209 static void __perf_event_exit_context(void *__info
)
9211 struct remove_event re
= { .detach_group
= true };
9212 struct perf_event_context
*ctx
= __info
;
9215 list_for_each_entry_rcu(re
.event
, &ctx
->event_list
, event_entry
)
9216 __perf_remove_from_context(&re
);
9220 static void perf_event_exit_cpu_context(int cpu
)
9222 struct perf_event_context
*ctx
;
9226 idx
= srcu_read_lock(&pmus_srcu
);
9227 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9228 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9230 mutex_lock(&ctx
->mutex
);
9231 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9232 mutex_unlock(&ctx
->mutex
);
9234 srcu_read_unlock(&pmus_srcu
, idx
);
9237 static void perf_event_exit_cpu(int cpu
)
9239 perf_event_exit_cpu_context(cpu
);
9242 static inline void perf_event_exit_cpu(int cpu
) { }
9246 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9250 for_each_online_cpu(cpu
)
9251 perf_event_exit_cpu(cpu
);
9257 * Run the perf reboot notifier at the very last possible moment so that
9258 * the generic watchdog code runs as long as possible.
9260 static struct notifier_block perf_reboot_notifier
= {
9261 .notifier_call
= perf_reboot
,
9262 .priority
= INT_MIN
,
9266 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9268 unsigned int cpu
= (long)hcpu
;
9270 switch (action
& ~CPU_TASKS_FROZEN
) {
9272 case CPU_UP_PREPARE
:
9273 case CPU_DOWN_FAILED
:
9274 perf_event_init_cpu(cpu
);
9277 case CPU_UP_CANCELED
:
9278 case CPU_DOWN_PREPARE
:
9279 perf_event_exit_cpu(cpu
);
9288 void __init
perf_event_init(void)
9294 perf_event_init_all_cpus();
9295 init_srcu_struct(&pmus_srcu
);
9296 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9297 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9298 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9300 perf_cpu_notifier(perf_cpu_notify
);
9301 register_reboot_notifier(&perf_reboot_notifier
);
9303 ret
= init_hw_breakpoint();
9304 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9306 /* do not patch jump label more than once per second */
9307 jump_label_rate_limit(&perf_sched_events
, HZ
);
9310 * Build time assertion that we keep the data_head at the intended
9311 * location. IOW, validation we got the __reserved[] size right.
9313 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9317 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9320 struct perf_pmu_events_attr
*pmu_attr
=
9321 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9323 if (pmu_attr
->event_str
)
9324 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9329 static int __init
perf_event_sysfs_init(void)
9334 mutex_lock(&pmus_lock
);
9336 ret
= bus_register(&pmu_bus
);
9340 list_for_each_entry(pmu
, &pmus
, entry
) {
9341 if (!pmu
->name
|| pmu
->type
< 0)
9344 ret
= pmu_dev_alloc(pmu
);
9345 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9347 pmu_bus_running
= 1;
9351 mutex_unlock(&pmus_lock
);
9355 device_initcall(perf_event_sysfs_init
);
9357 #ifdef CONFIG_CGROUP_PERF
9358 static struct cgroup_subsys_state
*
9359 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9361 struct perf_cgroup
*jc
;
9363 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9365 return ERR_PTR(-ENOMEM
);
9367 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9370 return ERR_PTR(-ENOMEM
);
9376 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9378 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9380 free_percpu(jc
->info
);
9384 static int __perf_cgroup_move(void *info
)
9386 struct task_struct
*task
= info
;
9388 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9393 static void perf_cgroup_attach(struct cgroup_taskset
*tset
)
9395 struct task_struct
*task
;
9396 struct cgroup_subsys_state
*css
;
9398 cgroup_taskset_for_each(task
, css
, tset
)
9399 task_function_call(task
, __perf_cgroup_move
, task
);
9402 struct cgroup_subsys perf_event_cgrp_subsys
= {
9403 .css_alloc
= perf_cgroup_css_alloc
,
9404 .css_free
= perf_cgroup_css_free
,
9405 .attach
= perf_cgroup_attach
,
9407 #endif /* CONFIG_CGROUP_PERF */