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 <pzijlstr@redhat.com>
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/perf_event.h>
38 #include <linux/ftrace_event.h>
39 #include <linux/hw_breakpoint.h>
40 #include <linux/mm_types.h>
41 #include <linux/cgroup.h>
45 #include <asm/irq_regs.h>
47 struct remote_function_call
{
48 struct task_struct
*p
;
49 int (*func
)(void *info
);
54 static void remote_function(void *data
)
56 struct remote_function_call
*tfc
= data
;
57 struct task_struct
*p
= tfc
->p
;
61 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
65 tfc
->ret
= tfc
->func(tfc
->info
);
69 * task_function_call - call a function on the cpu on which a task runs
70 * @p: the task to evaluate
71 * @func: the function to be called
72 * @info: the function call argument
74 * Calls the function @func when the task is currently running. This might
75 * be on the current CPU, which just calls the function directly
77 * returns: @func return value, or
78 * -ESRCH - when the process isn't running
79 * -EAGAIN - when the process moved away
82 task_function_call(struct task_struct
*p
, int (*func
) (void *info
), void *info
)
84 struct remote_function_call data
= {
88 .ret
= -ESRCH
, /* No such (running) process */
92 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
98 * cpu_function_call - call a function on the cpu
99 * @func: the function to be called
100 * @info: the function call argument
102 * Calls the function @func on the remote cpu.
104 * returns: @func return value or -ENXIO when the cpu is offline
106 static int cpu_function_call(int cpu
, int (*func
) (void *info
), void *info
)
108 struct remote_function_call data
= {
112 .ret
= -ENXIO
, /* No such CPU */
115 smp_call_function_single(cpu
, remote_function
, &data
, 1);
120 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
121 PERF_FLAG_FD_OUTPUT |\
122 PERF_FLAG_PID_CGROUP)
125 * branch priv levels that need permission checks
127 #define PERF_SAMPLE_BRANCH_PERM_PLM \
128 (PERF_SAMPLE_BRANCH_KERNEL |\
129 PERF_SAMPLE_BRANCH_HV)
132 EVENT_FLEXIBLE
= 0x1,
134 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
138 * perf_sched_events : >0 events exist
139 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
141 struct static_key_deferred perf_sched_events __read_mostly
;
142 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
143 static DEFINE_PER_CPU(atomic_t
, perf_branch_stack_events
);
145 static atomic_t nr_mmap_events __read_mostly
;
146 static atomic_t nr_comm_events __read_mostly
;
147 static atomic_t nr_task_events __read_mostly
;
148 static atomic_t nr_freq_events __read_mostly
;
150 static LIST_HEAD(pmus
);
151 static DEFINE_MUTEX(pmus_lock
);
152 static struct srcu_struct pmus_srcu
;
155 * perf event paranoia level:
156 * -1 - not paranoid at all
157 * 0 - disallow raw tracepoint access for unpriv
158 * 1 - disallow cpu events for unpriv
159 * 2 - disallow kernel profiling for unpriv
161 int sysctl_perf_event_paranoid __read_mostly
= 1;
163 /* Minimum for 512 kiB + 1 user control page */
164 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
167 * max perf event sample rate
169 #define DEFAULT_MAX_SAMPLE_RATE 100000
170 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
171 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
173 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
175 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
176 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
178 static int perf_sample_allowed_ns __read_mostly
=
179 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
181 void update_perf_cpu_limits(void)
183 u64 tmp
= perf_sample_period_ns
;
185 tmp
*= sysctl_perf_cpu_time_max_percent
;
187 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
190 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
192 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
193 void __user
*buffer
, size_t *lenp
,
196 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
201 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
202 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
203 update_perf_cpu_limits();
208 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
210 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
211 void __user
*buffer
, size_t *lenp
,
214 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
219 update_perf_cpu_limits();
225 * perf samples are done in some very critical code paths (NMIs).
226 * If they take too much CPU time, the system can lock up and not
227 * get any real work done. This will drop the sample rate when
228 * we detect that events are taking too long.
230 #define NR_ACCUMULATED_SAMPLES 128
231 static DEFINE_PER_CPU(u64
, running_sample_length
);
233 void perf_sample_event_took(u64 sample_len_ns
)
235 u64 avg_local_sample_len
;
236 u64 local_samples_len
;
237 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
242 /* decay the counter by 1 average sample */
243 local_samples_len
= __get_cpu_var(running_sample_length
);
244 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
245 local_samples_len
+= sample_len_ns
;
246 __get_cpu_var(running_sample_length
) = local_samples_len
;
249 * note: this will be biased artifically low until we have
250 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
251 * from having to maintain a count.
253 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
255 if (avg_local_sample_len
<= allowed_ns
)
258 if (max_samples_per_tick
<= 1)
261 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
262 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
263 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
265 printk_ratelimited(KERN_WARNING
266 "perf samples too long (%lld > %lld), lowering "
267 "kernel.perf_event_max_sample_rate to %d\n",
268 avg_local_sample_len
, allowed_ns
,
269 sysctl_perf_event_sample_rate
);
271 update_perf_cpu_limits();
274 static atomic64_t perf_event_id
;
276 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
277 enum event_type_t event_type
);
279 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
280 enum event_type_t event_type
,
281 struct task_struct
*task
);
283 static void update_context_time(struct perf_event_context
*ctx
);
284 static u64
perf_event_time(struct perf_event
*event
);
286 void __weak
perf_event_print_debug(void) { }
288 extern __weak
const char *perf_pmu_name(void)
293 static inline u64
perf_clock(void)
295 return local_clock();
298 static inline struct perf_cpu_context
*
299 __get_cpu_context(struct perf_event_context
*ctx
)
301 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
304 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
305 struct perf_event_context
*ctx
)
307 raw_spin_lock(&cpuctx
->ctx
.lock
);
309 raw_spin_lock(&ctx
->lock
);
312 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
313 struct perf_event_context
*ctx
)
316 raw_spin_unlock(&ctx
->lock
);
317 raw_spin_unlock(&cpuctx
->ctx
.lock
);
320 #ifdef CONFIG_CGROUP_PERF
323 * perf_cgroup_info keeps track of time_enabled for a cgroup.
324 * This is a per-cpu dynamically allocated data structure.
326 struct perf_cgroup_info
{
332 struct cgroup_subsys_state css
;
333 struct perf_cgroup_info __percpu
*info
;
337 * Must ensure cgroup is pinned (css_get) before calling
338 * this function. In other words, we cannot call this function
339 * if there is no cgroup event for the current CPU context.
341 static inline struct perf_cgroup
*
342 perf_cgroup_from_task(struct task_struct
*task
)
344 return container_of(task_css(task
, perf_subsys_id
),
345 struct perf_cgroup
, css
);
349 perf_cgroup_match(struct perf_event
*event
)
351 struct perf_event_context
*ctx
= event
->ctx
;
352 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
354 /* @event doesn't care about cgroup */
358 /* wants specific cgroup scope but @cpuctx isn't associated with any */
363 * Cgroup scoping is recursive. An event enabled for a cgroup is
364 * also enabled for all its descendant cgroups. If @cpuctx's
365 * cgroup is a descendant of @event's (the test covers identity
366 * case), it's a match.
368 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
369 event
->cgrp
->css
.cgroup
);
372 static inline bool perf_tryget_cgroup(struct perf_event
*event
)
374 return css_tryget(&event
->cgrp
->css
);
377 static inline void perf_put_cgroup(struct perf_event
*event
)
379 css_put(&event
->cgrp
->css
);
382 static inline void perf_detach_cgroup(struct perf_event
*event
)
384 perf_put_cgroup(event
);
388 static inline int is_cgroup_event(struct perf_event
*event
)
390 return event
->cgrp
!= NULL
;
393 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
395 struct perf_cgroup_info
*t
;
397 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
401 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
403 struct perf_cgroup_info
*info
;
408 info
= this_cpu_ptr(cgrp
->info
);
410 info
->time
+= now
- info
->timestamp
;
411 info
->timestamp
= now
;
414 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
416 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
418 __update_cgrp_time(cgrp_out
);
421 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
423 struct perf_cgroup
*cgrp
;
426 * ensure we access cgroup data only when needed and
427 * when we know the cgroup is pinned (css_get)
429 if (!is_cgroup_event(event
))
432 cgrp
= perf_cgroup_from_task(current
);
434 * Do not update time when cgroup is not active
436 if (cgrp
== event
->cgrp
)
437 __update_cgrp_time(event
->cgrp
);
441 perf_cgroup_set_timestamp(struct task_struct
*task
,
442 struct perf_event_context
*ctx
)
444 struct perf_cgroup
*cgrp
;
445 struct perf_cgroup_info
*info
;
448 * ctx->lock held by caller
449 * ensure we do not access cgroup data
450 * unless we have the cgroup pinned (css_get)
452 if (!task
|| !ctx
->nr_cgroups
)
455 cgrp
= perf_cgroup_from_task(task
);
456 info
= this_cpu_ptr(cgrp
->info
);
457 info
->timestamp
= ctx
->timestamp
;
460 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
461 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
464 * reschedule events based on the cgroup constraint of task.
466 * mode SWOUT : schedule out everything
467 * mode SWIN : schedule in based on cgroup for next
469 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
471 struct perf_cpu_context
*cpuctx
;
476 * disable interrupts to avoid geting nr_cgroup
477 * changes via __perf_event_disable(). Also
480 local_irq_save(flags
);
483 * we reschedule only in the presence of cgroup
484 * constrained events.
488 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
489 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
490 if (cpuctx
->unique_pmu
!= pmu
)
491 continue; /* ensure we process each cpuctx once */
494 * perf_cgroup_events says at least one
495 * context on this CPU has cgroup events.
497 * ctx->nr_cgroups reports the number of cgroup
498 * events for a context.
500 if (cpuctx
->ctx
.nr_cgroups
> 0) {
501 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
502 perf_pmu_disable(cpuctx
->ctx
.pmu
);
504 if (mode
& PERF_CGROUP_SWOUT
) {
505 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
507 * must not be done before ctxswout due
508 * to event_filter_match() in event_sched_out()
513 if (mode
& PERF_CGROUP_SWIN
) {
514 WARN_ON_ONCE(cpuctx
->cgrp
);
516 * set cgrp before ctxsw in to allow
517 * event_filter_match() to not have to pass
520 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
521 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
523 perf_pmu_enable(cpuctx
->ctx
.pmu
);
524 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
530 local_irq_restore(flags
);
533 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
534 struct task_struct
*next
)
536 struct perf_cgroup
*cgrp1
;
537 struct perf_cgroup
*cgrp2
= NULL
;
540 * we come here when we know perf_cgroup_events > 0
542 cgrp1
= perf_cgroup_from_task(task
);
545 * next is NULL when called from perf_event_enable_on_exec()
546 * that will systematically cause a cgroup_switch()
549 cgrp2
= perf_cgroup_from_task(next
);
552 * only schedule out current cgroup events if we know
553 * that we are switching to a different cgroup. Otherwise,
554 * do no touch the cgroup events.
557 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
560 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
561 struct task_struct
*task
)
563 struct perf_cgroup
*cgrp1
;
564 struct perf_cgroup
*cgrp2
= NULL
;
567 * we come here when we know perf_cgroup_events > 0
569 cgrp1
= perf_cgroup_from_task(task
);
571 /* prev can never be NULL */
572 cgrp2
= perf_cgroup_from_task(prev
);
575 * only need to schedule in cgroup events if we are changing
576 * cgroup during ctxsw. Cgroup events were not scheduled
577 * out of ctxsw out if that was not the case.
580 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
583 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
584 struct perf_event_attr
*attr
,
585 struct perf_event
*group_leader
)
587 struct perf_cgroup
*cgrp
;
588 struct cgroup_subsys_state
*css
;
589 struct fd f
= fdget(fd
);
597 css
= css_from_dir(f
.file
->f_dentry
, &perf_subsys
);
603 cgrp
= container_of(css
, struct perf_cgroup
, css
);
606 /* must be done before we fput() the file */
607 if (!perf_tryget_cgroup(event
)) {
614 * all events in a group must monitor
615 * the same cgroup because a task belongs
616 * to only one perf cgroup at a time
618 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
619 perf_detach_cgroup(event
);
629 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
631 struct perf_cgroup_info
*t
;
632 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
633 event
->shadow_ctx_time
= now
- t
->timestamp
;
637 perf_cgroup_defer_enabled(struct perf_event
*event
)
640 * when the current task's perf cgroup does not match
641 * the event's, we need to remember to call the
642 * perf_mark_enable() function the first time a task with
643 * a matching perf cgroup is scheduled in.
645 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
646 event
->cgrp_defer_enabled
= 1;
650 perf_cgroup_mark_enabled(struct perf_event
*event
,
651 struct perf_event_context
*ctx
)
653 struct perf_event
*sub
;
654 u64 tstamp
= perf_event_time(event
);
656 if (!event
->cgrp_defer_enabled
)
659 event
->cgrp_defer_enabled
= 0;
661 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
662 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
663 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
664 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
665 sub
->cgrp_defer_enabled
= 0;
669 #else /* !CONFIG_CGROUP_PERF */
672 perf_cgroup_match(struct perf_event
*event
)
677 static inline void perf_detach_cgroup(struct perf_event
*event
)
680 static inline int is_cgroup_event(struct perf_event
*event
)
685 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
690 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
694 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
698 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
699 struct task_struct
*next
)
703 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
704 struct task_struct
*task
)
708 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
709 struct perf_event_attr
*attr
,
710 struct perf_event
*group_leader
)
716 perf_cgroup_set_timestamp(struct task_struct
*task
,
717 struct perf_event_context
*ctx
)
722 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
727 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
731 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
737 perf_cgroup_defer_enabled(struct perf_event
*event
)
742 perf_cgroup_mark_enabled(struct perf_event
*event
,
743 struct perf_event_context
*ctx
)
749 * set default to be dependent on timer tick just
752 #define PERF_CPU_HRTIMER (1000 / HZ)
754 * function must be called with interrupts disbled
756 static enum hrtimer_restart
perf_cpu_hrtimer_handler(struct hrtimer
*hr
)
758 struct perf_cpu_context
*cpuctx
;
759 enum hrtimer_restart ret
= HRTIMER_NORESTART
;
762 WARN_ON(!irqs_disabled());
764 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
766 rotations
= perf_rotate_context(cpuctx
);
769 * arm timer if needed
772 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
773 ret
= HRTIMER_RESTART
;
779 /* CPU is going down */
780 void perf_cpu_hrtimer_cancel(int cpu
)
782 struct perf_cpu_context
*cpuctx
;
786 if (WARN_ON(cpu
!= smp_processor_id()))
789 local_irq_save(flags
);
793 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
794 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
796 if (pmu
->task_ctx_nr
== perf_sw_context
)
799 hrtimer_cancel(&cpuctx
->hrtimer
);
804 local_irq_restore(flags
);
807 static void __perf_cpu_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
809 struct hrtimer
*hr
= &cpuctx
->hrtimer
;
810 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
813 /* no multiplexing needed for SW PMU */
814 if (pmu
->task_ctx_nr
== perf_sw_context
)
818 * check default is sane, if not set then force to
819 * default interval (1/tick)
821 timer
= pmu
->hrtimer_interval_ms
;
823 timer
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
825 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
827 hrtimer_init(hr
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL_PINNED
);
828 hr
->function
= perf_cpu_hrtimer_handler
;
831 static void perf_cpu_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
833 struct hrtimer
*hr
= &cpuctx
->hrtimer
;
834 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
837 if (pmu
->task_ctx_nr
== perf_sw_context
)
840 if (hrtimer_active(hr
))
843 if (!hrtimer_callback_running(hr
))
844 __hrtimer_start_range_ns(hr
, cpuctx
->hrtimer_interval
,
845 0, HRTIMER_MODE_REL_PINNED
, 0);
848 void perf_pmu_disable(struct pmu
*pmu
)
850 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
852 pmu
->pmu_disable(pmu
);
855 void perf_pmu_enable(struct pmu
*pmu
)
857 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
859 pmu
->pmu_enable(pmu
);
862 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
865 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
866 * because they're strictly cpu affine and rotate_start is called with IRQs
867 * disabled, while rotate_context is called from IRQ context.
869 static void perf_pmu_rotate_start(struct pmu
*pmu
)
871 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
872 struct list_head
*head
= &__get_cpu_var(rotation_list
);
874 WARN_ON(!irqs_disabled());
876 if (list_empty(&cpuctx
->rotation_list
))
877 list_add(&cpuctx
->rotation_list
, head
);
880 static void get_ctx(struct perf_event_context
*ctx
)
882 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
885 static void put_ctx(struct perf_event_context
*ctx
)
887 if (atomic_dec_and_test(&ctx
->refcount
)) {
889 put_ctx(ctx
->parent_ctx
);
891 put_task_struct(ctx
->task
);
892 kfree_rcu(ctx
, rcu_head
);
896 static void unclone_ctx(struct perf_event_context
*ctx
)
898 if (ctx
->parent_ctx
) {
899 put_ctx(ctx
->parent_ctx
);
900 ctx
->parent_ctx
= NULL
;
904 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
907 * only top level events have the pid namespace they were created in
910 event
= event
->parent
;
912 return task_tgid_nr_ns(p
, event
->ns
);
915 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
918 * only top level events have the pid namespace they were created in
921 event
= event
->parent
;
923 return task_pid_nr_ns(p
, event
->ns
);
927 * If we inherit events we want to return the parent event id
930 static u64
primary_event_id(struct perf_event
*event
)
935 id
= event
->parent
->id
;
941 * Get the perf_event_context for a task and lock it.
942 * This has to cope with with the fact that until it is locked,
943 * the context could get moved to another task.
945 static struct perf_event_context
*
946 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
948 struct perf_event_context
*ctx
;
952 * One of the few rules of preemptible RCU is that one cannot do
953 * rcu_read_unlock() while holding a scheduler (or nested) lock when
954 * part of the read side critical section was preemptible -- see
955 * rcu_read_unlock_special().
957 * Since ctx->lock nests under rq->lock we must ensure the entire read
958 * side critical section is non-preemptible.
962 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
965 * If this context is a clone of another, it might
966 * get swapped for another underneath us by
967 * perf_event_task_sched_out, though the
968 * rcu_read_lock() protects us from any context
969 * getting freed. Lock the context and check if it
970 * got swapped before we could get the lock, and retry
971 * if so. If we locked the right context, then it
972 * can't get swapped on us any more.
974 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
975 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
976 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
982 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
983 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
993 * Get the context for a task and increment its pin_count so it
994 * can't get swapped to another task. This also increments its
995 * reference count so that the context can't get freed.
997 static struct perf_event_context
*
998 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1000 struct perf_event_context
*ctx
;
1001 unsigned long flags
;
1003 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1006 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1011 static void perf_unpin_context(struct perf_event_context
*ctx
)
1013 unsigned long flags
;
1015 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1017 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1021 * Update the record of the current time in a context.
1023 static void update_context_time(struct perf_event_context
*ctx
)
1025 u64 now
= perf_clock();
1027 ctx
->time
+= now
- ctx
->timestamp
;
1028 ctx
->timestamp
= now
;
1031 static u64
perf_event_time(struct perf_event
*event
)
1033 struct perf_event_context
*ctx
= event
->ctx
;
1035 if (is_cgroup_event(event
))
1036 return perf_cgroup_event_time(event
);
1038 return ctx
? ctx
->time
: 0;
1042 * Update the total_time_enabled and total_time_running fields for a event.
1043 * The caller of this function needs to hold the ctx->lock.
1045 static void update_event_times(struct perf_event
*event
)
1047 struct perf_event_context
*ctx
= event
->ctx
;
1050 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1051 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1054 * in cgroup mode, time_enabled represents
1055 * the time the event was enabled AND active
1056 * tasks were in the monitored cgroup. This is
1057 * independent of the activity of the context as
1058 * there may be a mix of cgroup and non-cgroup events.
1060 * That is why we treat cgroup events differently
1063 if (is_cgroup_event(event
))
1064 run_end
= perf_cgroup_event_time(event
);
1065 else if (ctx
->is_active
)
1066 run_end
= ctx
->time
;
1068 run_end
= event
->tstamp_stopped
;
1070 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1072 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1073 run_end
= event
->tstamp_stopped
;
1075 run_end
= perf_event_time(event
);
1077 event
->total_time_running
= run_end
- event
->tstamp_running
;
1082 * Update total_time_enabled and total_time_running for all events in a group.
1084 static void update_group_times(struct perf_event
*leader
)
1086 struct perf_event
*event
;
1088 update_event_times(leader
);
1089 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1090 update_event_times(event
);
1093 static struct list_head
*
1094 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1096 if (event
->attr
.pinned
)
1097 return &ctx
->pinned_groups
;
1099 return &ctx
->flexible_groups
;
1103 * Add a event from the lists for its context.
1104 * Must be called with ctx->mutex and ctx->lock held.
1107 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1109 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1110 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1113 * If we're a stand alone event or group leader, we go to the context
1114 * list, group events are kept attached to the group so that
1115 * perf_group_detach can, at all times, locate all siblings.
1117 if (event
->group_leader
== event
) {
1118 struct list_head
*list
;
1120 if (is_software_event(event
))
1121 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1123 list
= ctx_group_list(event
, ctx
);
1124 list_add_tail(&event
->group_entry
, list
);
1127 if (is_cgroup_event(event
))
1130 if (has_branch_stack(event
))
1131 ctx
->nr_branch_stack
++;
1133 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1134 if (!ctx
->nr_events
)
1135 perf_pmu_rotate_start(ctx
->pmu
);
1137 if (event
->attr
.inherit_stat
)
1142 * Initialize event state based on the perf_event_attr::disabled.
1144 static inline void perf_event__state_init(struct perf_event
*event
)
1146 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1147 PERF_EVENT_STATE_INACTIVE
;
1151 * Called at perf_event creation and when events are attached/detached from a
1154 static void perf_event__read_size(struct perf_event
*event
)
1156 int entry
= sizeof(u64
); /* value */
1160 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1161 size
+= sizeof(u64
);
1163 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1164 size
+= sizeof(u64
);
1166 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1167 entry
+= sizeof(u64
);
1169 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1170 nr
+= event
->group_leader
->nr_siblings
;
1171 size
+= sizeof(u64
);
1175 event
->read_size
= size
;
1178 static void perf_event__header_size(struct perf_event
*event
)
1180 struct perf_sample_data
*data
;
1181 u64 sample_type
= event
->attr
.sample_type
;
1184 perf_event__read_size(event
);
1186 if (sample_type
& PERF_SAMPLE_IP
)
1187 size
+= sizeof(data
->ip
);
1189 if (sample_type
& PERF_SAMPLE_ADDR
)
1190 size
+= sizeof(data
->addr
);
1192 if (sample_type
& PERF_SAMPLE_PERIOD
)
1193 size
+= sizeof(data
->period
);
1195 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1196 size
+= sizeof(data
->weight
);
1198 if (sample_type
& PERF_SAMPLE_READ
)
1199 size
+= event
->read_size
;
1201 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1202 size
+= sizeof(data
->data_src
.val
);
1204 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1205 size
+= sizeof(data
->txn
);
1207 event
->header_size
= size
;
1210 static void perf_event__id_header_size(struct perf_event
*event
)
1212 struct perf_sample_data
*data
;
1213 u64 sample_type
= event
->attr
.sample_type
;
1216 if (sample_type
& PERF_SAMPLE_TID
)
1217 size
+= sizeof(data
->tid_entry
);
1219 if (sample_type
& PERF_SAMPLE_TIME
)
1220 size
+= sizeof(data
->time
);
1222 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1223 size
+= sizeof(data
->id
);
1225 if (sample_type
& PERF_SAMPLE_ID
)
1226 size
+= sizeof(data
->id
);
1228 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1229 size
+= sizeof(data
->stream_id
);
1231 if (sample_type
& PERF_SAMPLE_CPU
)
1232 size
+= sizeof(data
->cpu_entry
);
1234 event
->id_header_size
= size
;
1237 static void perf_group_attach(struct perf_event
*event
)
1239 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1242 * We can have double attach due to group movement in perf_event_open.
1244 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1247 event
->attach_state
|= PERF_ATTACH_GROUP
;
1249 if (group_leader
== event
)
1252 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1253 !is_software_event(event
))
1254 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1256 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1257 group_leader
->nr_siblings
++;
1259 perf_event__header_size(group_leader
);
1261 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1262 perf_event__header_size(pos
);
1266 * Remove a event from the lists for its context.
1267 * Must be called with ctx->mutex and ctx->lock held.
1270 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1272 struct perf_cpu_context
*cpuctx
;
1274 * We can have double detach due to exit/hot-unplug + close.
1276 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1279 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1281 if (is_cgroup_event(event
)) {
1283 cpuctx
= __get_cpu_context(ctx
);
1285 * if there are no more cgroup events
1286 * then cler cgrp to avoid stale pointer
1287 * in update_cgrp_time_from_cpuctx()
1289 if (!ctx
->nr_cgroups
)
1290 cpuctx
->cgrp
= NULL
;
1293 if (has_branch_stack(event
))
1294 ctx
->nr_branch_stack
--;
1297 if (event
->attr
.inherit_stat
)
1300 list_del_rcu(&event
->event_entry
);
1302 if (event
->group_leader
== event
)
1303 list_del_init(&event
->group_entry
);
1305 update_group_times(event
);
1308 * If event was in error state, then keep it
1309 * that way, otherwise bogus counts will be
1310 * returned on read(). The only way to get out
1311 * of error state is by explicit re-enabling
1314 if (event
->state
> PERF_EVENT_STATE_OFF
)
1315 event
->state
= PERF_EVENT_STATE_OFF
;
1318 static void perf_group_detach(struct perf_event
*event
)
1320 struct perf_event
*sibling
, *tmp
;
1321 struct list_head
*list
= NULL
;
1324 * We can have double detach due to exit/hot-unplug + close.
1326 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1329 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1332 * If this is a sibling, remove it from its group.
1334 if (event
->group_leader
!= event
) {
1335 list_del_init(&event
->group_entry
);
1336 event
->group_leader
->nr_siblings
--;
1340 if (!list_empty(&event
->group_entry
))
1341 list
= &event
->group_entry
;
1344 * If this was a group event with sibling events then
1345 * upgrade the siblings to singleton events by adding them
1346 * to whatever list we are on.
1348 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1350 list_move_tail(&sibling
->group_entry
, list
);
1351 sibling
->group_leader
= sibling
;
1353 /* Inherit group flags from the previous leader */
1354 sibling
->group_flags
= event
->group_flags
;
1358 perf_event__header_size(event
->group_leader
);
1360 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1361 perf_event__header_size(tmp
);
1365 event_filter_match(struct perf_event
*event
)
1367 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1368 && perf_cgroup_match(event
);
1372 event_sched_out(struct perf_event
*event
,
1373 struct perf_cpu_context
*cpuctx
,
1374 struct perf_event_context
*ctx
)
1376 u64 tstamp
= perf_event_time(event
);
1379 * An event which could not be activated because of
1380 * filter mismatch still needs to have its timings
1381 * maintained, otherwise bogus information is return
1382 * via read() for time_enabled, time_running:
1384 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1385 && !event_filter_match(event
)) {
1386 delta
= tstamp
- event
->tstamp_stopped
;
1387 event
->tstamp_running
+= delta
;
1388 event
->tstamp_stopped
= tstamp
;
1391 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1394 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1395 if (event
->pending_disable
) {
1396 event
->pending_disable
= 0;
1397 event
->state
= PERF_EVENT_STATE_OFF
;
1399 event
->tstamp_stopped
= tstamp
;
1400 event
->pmu
->del(event
, 0);
1403 if (!is_software_event(event
))
1404 cpuctx
->active_oncpu
--;
1406 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1408 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1409 cpuctx
->exclusive
= 0;
1413 group_sched_out(struct perf_event
*group_event
,
1414 struct perf_cpu_context
*cpuctx
,
1415 struct perf_event_context
*ctx
)
1417 struct perf_event
*event
;
1418 int state
= group_event
->state
;
1420 event_sched_out(group_event
, cpuctx
, ctx
);
1423 * Schedule out siblings (if any):
1425 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1426 event_sched_out(event
, cpuctx
, ctx
);
1428 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1429 cpuctx
->exclusive
= 0;
1433 * Cross CPU call to remove a performance event
1435 * We disable the event on the hardware level first. After that we
1436 * remove it from the context list.
1438 static int __perf_remove_from_context(void *info
)
1440 struct perf_event
*event
= info
;
1441 struct perf_event_context
*ctx
= event
->ctx
;
1442 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1444 raw_spin_lock(&ctx
->lock
);
1445 event_sched_out(event
, cpuctx
, ctx
);
1446 list_del_event(event
, ctx
);
1447 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1449 cpuctx
->task_ctx
= NULL
;
1451 raw_spin_unlock(&ctx
->lock
);
1458 * Remove the event from a task's (or a CPU's) list of events.
1460 * CPU events are removed with a smp call. For task events we only
1461 * call when the task is on a CPU.
1463 * If event->ctx is a cloned context, callers must make sure that
1464 * every task struct that event->ctx->task could possibly point to
1465 * remains valid. This is OK when called from perf_release since
1466 * that only calls us on the top-level context, which can't be a clone.
1467 * When called from perf_event_exit_task, it's OK because the
1468 * context has been detached from its task.
1470 static void perf_remove_from_context(struct perf_event
*event
)
1472 struct perf_event_context
*ctx
= event
->ctx
;
1473 struct task_struct
*task
= ctx
->task
;
1475 lockdep_assert_held(&ctx
->mutex
);
1479 * Per cpu events are removed via an smp call and
1480 * the removal is always successful.
1482 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1487 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1490 raw_spin_lock_irq(&ctx
->lock
);
1492 * If we failed to find a running task, but find the context active now
1493 * that we've acquired the ctx->lock, retry.
1495 if (ctx
->is_active
) {
1496 raw_spin_unlock_irq(&ctx
->lock
);
1501 * Since the task isn't running, its safe to remove the event, us
1502 * holding the ctx->lock ensures the task won't get scheduled in.
1504 list_del_event(event
, ctx
);
1505 raw_spin_unlock_irq(&ctx
->lock
);
1509 * Cross CPU call to disable a performance event
1511 int __perf_event_disable(void *info
)
1513 struct perf_event
*event
= info
;
1514 struct perf_event_context
*ctx
= event
->ctx
;
1515 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1518 * If this is a per-task event, need to check whether this
1519 * event's task is the current task on this cpu.
1521 * Can trigger due to concurrent perf_event_context_sched_out()
1522 * flipping contexts around.
1524 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1527 raw_spin_lock(&ctx
->lock
);
1530 * If the event is on, turn it off.
1531 * If it is in error state, leave it in error state.
1533 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1534 update_context_time(ctx
);
1535 update_cgrp_time_from_event(event
);
1536 update_group_times(event
);
1537 if (event
== event
->group_leader
)
1538 group_sched_out(event
, cpuctx
, ctx
);
1540 event_sched_out(event
, cpuctx
, ctx
);
1541 event
->state
= PERF_EVENT_STATE_OFF
;
1544 raw_spin_unlock(&ctx
->lock
);
1552 * If event->ctx is a cloned context, callers must make sure that
1553 * every task struct that event->ctx->task could possibly point to
1554 * remains valid. This condition is satisifed when called through
1555 * perf_event_for_each_child or perf_event_for_each because they
1556 * hold the top-level event's child_mutex, so any descendant that
1557 * goes to exit will block in sync_child_event.
1558 * When called from perf_pending_event it's OK because event->ctx
1559 * is the current context on this CPU and preemption is disabled,
1560 * hence we can't get into perf_event_task_sched_out for this context.
1562 void perf_event_disable(struct perf_event
*event
)
1564 struct perf_event_context
*ctx
= event
->ctx
;
1565 struct task_struct
*task
= ctx
->task
;
1569 * Disable the event on the cpu that it's on
1571 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1576 if (!task_function_call(task
, __perf_event_disable
, event
))
1579 raw_spin_lock_irq(&ctx
->lock
);
1581 * If the event is still active, we need to retry the cross-call.
1583 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1584 raw_spin_unlock_irq(&ctx
->lock
);
1586 * Reload the task pointer, it might have been changed by
1587 * a concurrent perf_event_context_sched_out().
1594 * Since we have the lock this context can't be scheduled
1595 * in, so we can change the state safely.
1597 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1598 update_group_times(event
);
1599 event
->state
= PERF_EVENT_STATE_OFF
;
1601 raw_spin_unlock_irq(&ctx
->lock
);
1603 EXPORT_SYMBOL_GPL(perf_event_disable
);
1605 static void perf_set_shadow_time(struct perf_event
*event
,
1606 struct perf_event_context
*ctx
,
1610 * use the correct time source for the time snapshot
1612 * We could get by without this by leveraging the
1613 * fact that to get to this function, the caller
1614 * has most likely already called update_context_time()
1615 * and update_cgrp_time_xx() and thus both timestamp
1616 * are identical (or very close). Given that tstamp is,
1617 * already adjusted for cgroup, we could say that:
1618 * tstamp - ctx->timestamp
1620 * tstamp - cgrp->timestamp.
1622 * Then, in perf_output_read(), the calculation would
1623 * work with no changes because:
1624 * - event is guaranteed scheduled in
1625 * - no scheduled out in between
1626 * - thus the timestamp would be the same
1628 * But this is a bit hairy.
1630 * So instead, we have an explicit cgroup call to remain
1631 * within the time time source all along. We believe it
1632 * is cleaner and simpler to understand.
1634 if (is_cgroup_event(event
))
1635 perf_cgroup_set_shadow_time(event
, tstamp
);
1637 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1640 #define MAX_INTERRUPTS (~0ULL)
1642 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1645 event_sched_in(struct perf_event
*event
,
1646 struct perf_cpu_context
*cpuctx
,
1647 struct perf_event_context
*ctx
)
1649 u64 tstamp
= perf_event_time(event
);
1651 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1654 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1655 event
->oncpu
= smp_processor_id();
1658 * Unthrottle events, since we scheduled we might have missed several
1659 * ticks already, also for a heavily scheduling task there is little
1660 * guarantee it'll get a tick in a timely manner.
1662 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1663 perf_log_throttle(event
, 1);
1664 event
->hw
.interrupts
= 0;
1668 * The new state must be visible before we turn it on in the hardware:
1672 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1673 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1678 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1680 perf_set_shadow_time(event
, ctx
, tstamp
);
1682 if (!is_software_event(event
))
1683 cpuctx
->active_oncpu
++;
1685 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1688 if (event
->attr
.exclusive
)
1689 cpuctx
->exclusive
= 1;
1695 group_sched_in(struct perf_event
*group_event
,
1696 struct perf_cpu_context
*cpuctx
,
1697 struct perf_event_context
*ctx
)
1699 struct perf_event
*event
, *partial_group
= NULL
;
1700 struct pmu
*pmu
= group_event
->pmu
;
1701 u64 now
= ctx
->time
;
1702 bool simulate
= false;
1704 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1707 pmu
->start_txn(pmu
);
1709 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1710 pmu
->cancel_txn(pmu
);
1711 perf_cpu_hrtimer_restart(cpuctx
);
1716 * Schedule in siblings as one group (if any):
1718 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1719 if (event_sched_in(event
, cpuctx
, ctx
)) {
1720 partial_group
= event
;
1725 if (!pmu
->commit_txn(pmu
))
1730 * Groups can be scheduled in as one unit only, so undo any
1731 * partial group before returning:
1732 * The events up to the failed event are scheduled out normally,
1733 * tstamp_stopped will be updated.
1735 * The failed events and the remaining siblings need to have
1736 * their timings updated as if they had gone thru event_sched_in()
1737 * and event_sched_out(). This is required to get consistent timings
1738 * across the group. This also takes care of the case where the group
1739 * could never be scheduled by ensuring tstamp_stopped is set to mark
1740 * the time the event was actually stopped, such that time delta
1741 * calculation in update_event_times() is correct.
1743 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1744 if (event
== partial_group
)
1748 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1749 event
->tstamp_stopped
= now
;
1751 event_sched_out(event
, cpuctx
, ctx
);
1754 event_sched_out(group_event
, cpuctx
, ctx
);
1756 pmu
->cancel_txn(pmu
);
1758 perf_cpu_hrtimer_restart(cpuctx
);
1764 * Work out whether we can put this event group on the CPU now.
1766 static int group_can_go_on(struct perf_event
*event
,
1767 struct perf_cpu_context
*cpuctx
,
1771 * Groups consisting entirely of software events can always go on.
1773 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1776 * If an exclusive group is already on, no other hardware
1779 if (cpuctx
->exclusive
)
1782 * If this group is exclusive and there are already
1783 * events on the CPU, it can't go on.
1785 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1788 * Otherwise, try to add it if all previous groups were able
1794 static void add_event_to_ctx(struct perf_event
*event
,
1795 struct perf_event_context
*ctx
)
1797 u64 tstamp
= perf_event_time(event
);
1799 list_add_event(event
, ctx
);
1800 perf_group_attach(event
);
1801 event
->tstamp_enabled
= tstamp
;
1802 event
->tstamp_running
= tstamp
;
1803 event
->tstamp_stopped
= tstamp
;
1806 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
1808 ctx_sched_in(struct perf_event_context
*ctx
,
1809 struct perf_cpu_context
*cpuctx
,
1810 enum event_type_t event_type
,
1811 struct task_struct
*task
);
1813 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
1814 struct perf_event_context
*ctx
,
1815 struct task_struct
*task
)
1817 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
1819 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
1820 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
1822 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
1826 * Cross CPU call to install and enable a performance event
1828 * Must be called with ctx->mutex held
1830 static int __perf_install_in_context(void *info
)
1832 struct perf_event
*event
= info
;
1833 struct perf_event_context
*ctx
= event
->ctx
;
1834 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1835 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
1836 struct task_struct
*task
= current
;
1838 perf_ctx_lock(cpuctx
, task_ctx
);
1839 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1842 * If there was an active task_ctx schedule it out.
1845 task_ctx_sched_out(task_ctx
);
1848 * If the context we're installing events in is not the
1849 * active task_ctx, flip them.
1851 if (ctx
->task
&& task_ctx
!= ctx
) {
1853 raw_spin_unlock(&task_ctx
->lock
);
1854 raw_spin_lock(&ctx
->lock
);
1859 cpuctx
->task_ctx
= task_ctx
;
1860 task
= task_ctx
->task
;
1863 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
1865 update_context_time(ctx
);
1867 * update cgrp time only if current cgrp
1868 * matches event->cgrp. Must be done before
1869 * calling add_event_to_ctx()
1871 update_cgrp_time_from_event(event
);
1873 add_event_to_ctx(event
, ctx
);
1876 * Schedule everything back in
1878 perf_event_sched_in(cpuctx
, task_ctx
, task
);
1880 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1881 perf_ctx_unlock(cpuctx
, task_ctx
);
1887 * Attach a performance event to a context
1889 * First we add the event to the list with the hardware enable bit
1890 * in event->hw_config cleared.
1892 * If the event is attached to a task which is on a CPU we use a smp
1893 * call to enable it in the task context. The task might have been
1894 * scheduled away, but we check this in the smp call again.
1897 perf_install_in_context(struct perf_event_context
*ctx
,
1898 struct perf_event
*event
,
1901 struct task_struct
*task
= ctx
->task
;
1903 lockdep_assert_held(&ctx
->mutex
);
1906 if (event
->cpu
!= -1)
1911 * Per cpu events are installed via an smp call and
1912 * the install is always successful.
1914 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1919 if (!task_function_call(task
, __perf_install_in_context
, event
))
1922 raw_spin_lock_irq(&ctx
->lock
);
1924 * If we failed to find a running task, but find the context active now
1925 * that we've acquired the ctx->lock, retry.
1927 if (ctx
->is_active
) {
1928 raw_spin_unlock_irq(&ctx
->lock
);
1933 * Since the task isn't running, its safe to add the event, us holding
1934 * the ctx->lock ensures the task won't get scheduled in.
1936 add_event_to_ctx(event
, ctx
);
1937 raw_spin_unlock_irq(&ctx
->lock
);
1941 * Put a event into inactive state and update time fields.
1942 * Enabling the leader of a group effectively enables all
1943 * the group members that aren't explicitly disabled, so we
1944 * have to update their ->tstamp_enabled also.
1945 * Note: this works for group members as well as group leaders
1946 * since the non-leader members' sibling_lists will be empty.
1948 static void __perf_event_mark_enabled(struct perf_event
*event
)
1950 struct perf_event
*sub
;
1951 u64 tstamp
= perf_event_time(event
);
1953 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1954 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1955 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1956 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1957 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1962 * Cross CPU call to enable a performance event
1964 static int __perf_event_enable(void *info
)
1966 struct perf_event
*event
= info
;
1967 struct perf_event_context
*ctx
= event
->ctx
;
1968 struct perf_event
*leader
= event
->group_leader
;
1969 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1973 * There's a time window between 'ctx->is_active' check
1974 * in perf_event_enable function and this place having:
1976 * - ctx->lock unlocked
1978 * where the task could be killed and 'ctx' deactivated
1979 * by perf_event_exit_task.
1981 if (!ctx
->is_active
)
1984 raw_spin_lock(&ctx
->lock
);
1985 update_context_time(ctx
);
1987 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1991 * set current task's cgroup time reference point
1993 perf_cgroup_set_timestamp(current
, ctx
);
1995 __perf_event_mark_enabled(event
);
1997 if (!event_filter_match(event
)) {
1998 if (is_cgroup_event(event
))
1999 perf_cgroup_defer_enabled(event
);
2004 * If the event is in a group and isn't the group leader,
2005 * then don't put it on unless the group is on.
2007 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2010 if (!group_can_go_on(event
, cpuctx
, 1)) {
2013 if (event
== leader
)
2014 err
= group_sched_in(event
, cpuctx
, ctx
);
2016 err
= event_sched_in(event
, cpuctx
, ctx
);
2021 * If this event can't go on and it's part of a
2022 * group, then the whole group has to come off.
2024 if (leader
!= event
) {
2025 group_sched_out(leader
, cpuctx
, ctx
);
2026 perf_cpu_hrtimer_restart(cpuctx
);
2028 if (leader
->attr
.pinned
) {
2029 update_group_times(leader
);
2030 leader
->state
= PERF_EVENT_STATE_ERROR
;
2035 raw_spin_unlock(&ctx
->lock
);
2043 * If event->ctx is a cloned context, callers must make sure that
2044 * every task struct that event->ctx->task could possibly point to
2045 * remains valid. This condition is satisfied when called through
2046 * perf_event_for_each_child or perf_event_for_each as described
2047 * for perf_event_disable.
2049 void perf_event_enable(struct perf_event
*event
)
2051 struct perf_event_context
*ctx
= event
->ctx
;
2052 struct task_struct
*task
= ctx
->task
;
2056 * Enable the event on the cpu that it's on
2058 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
2062 raw_spin_lock_irq(&ctx
->lock
);
2063 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2067 * If the event is in error state, clear that first.
2068 * That way, if we see the event in error state below, we
2069 * know that it has gone back into error state, as distinct
2070 * from the task having been scheduled away before the
2071 * cross-call arrived.
2073 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2074 event
->state
= PERF_EVENT_STATE_OFF
;
2077 if (!ctx
->is_active
) {
2078 __perf_event_mark_enabled(event
);
2082 raw_spin_unlock_irq(&ctx
->lock
);
2084 if (!task_function_call(task
, __perf_event_enable
, event
))
2087 raw_spin_lock_irq(&ctx
->lock
);
2090 * If the context is active and the event is still off,
2091 * we need to retry the cross-call.
2093 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
2095 * task could have been flipped by a concurrent
2096 * perf_event_context_sched_out()
2103 raw_spin_unlock_irq(&ctx
->lock
);
2105 EXPORT_SYMBOL_GPL(perf_event_enable
);
2107 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2110 * not supported on inherited events
2112 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2115 atomic_add(refresh
, &event
->event_limit
);
2116 perf_event_enable(event
);
2120 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2122 static void ctx_sched_out(struct perf_event_context
*ctx
,
2123 struct perf_cpu_context
*cpuctx
,
2124 enum event_type_t event_type
)
2126 struct perf_event
*event
;
2127 int is_active
= ctx
->is_active
;
2129 ctx
->is_active
&= ~event_type
;
2130 if (likely(!ctx
->nr_events
))
2133 update_context_time(ctx
);
2134 update_cgrp_time_from_cpuctx(cpuctx
);
2135 if (!ctx
->nr_active
)
2138 perf_pmu_disable(ctx
->pmu
);
2139 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2140 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2141 group_sched_out(event
, cpuctx
, ctx
);
2144 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2145 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2146 group_sched_out(event
, cpuctx
, ctx
);
2148 perf_pmu_enable(ctx
->pmu
);
2152 * Test whether two contexts are equivalent, i.e. whether they
2153 * have both been cloned from the same version of the same context
2154 * and they both have the same number of enabled events.
2155 * If the number of enabled events is the same, then the set
2156 * of enabled events should be the same, because these are both
2157 * inherited contexts, therefore we can't access individual events
2158 * in them directly with an fd; we can only enable/disable all
2159 * events via prctl, or enable/disable all events in a family
2160 * via ioctl, which will have the same effect on both contexts.
2162 static int context_equiv(struct perf_event_context
*ctx1
,
2163 struct perf_event_context
*ctx2
)
2165 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
2166 && ctx1
->parent_gen
== ctx2
->parent_gen
2167 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
2170 static void __perf_event_sync_stat(struct perf_event
*event
,
2171 struct perf_event
*next_event
)
2175 if (!event
->attr
.inherit_stat
)
2179 * Update the event value, we cannot use perf_event_read()
2180 * because we're in the middle of a context switch and have IRQs
2181 * disabled, which upsets smp_call_function_single(), however
2182 * we know the event must be on the current CPU, therefore we
2183 * don't need to use it.
2185 switch (event
->state
) {
2186 case PERF_EVENT_STATE_ACTIVE
:
2187 event
->pmu
->read(event
);
2190 case PERF_EVENT_STATE_INACTIVE
:
2191 update_event_times(event
);
2199 * In order to keep per-task stats reliable we need to flip the event
2200 * values when we flip the contexts.
2202 value
= local64_read(&next_event
->count
);
2203 value
= local64_xchg(&event
->count
, value
);
2204 local64_set(&next_event
->count
, value
);
2206 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2207 swap(event
->total_time_running
, next_event
->total_time_running
);
2210 * Since we swizzled the values, update the user visible data too.
2212 perf_event_update_userpage(event
);
2213 perf_event_update_userpage(next_event
);
2216 #define list_next_entry(pos, member) \
2217 list_entry(pos->member.next, typeof(*pos), member)
2219 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2220 struct perf_event_context
*next_ctx
)
2222 struct perf_event
*event
, *next_event
;
2227 update_context_time(ctx
);
2229 event
= list_first_entry(&ctx
->event_list
,
2230 struct perf_event
, event_entry
);
2232 next_event
= list_first_entry(&next_ctx
->event_list
,
2233 struct perf_event
, event_entry
);
2235 while (&event
->event_entry
!= &ctx
->event_list
&&
2236 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2238 __perf_event_sync_stat(event
, next_event
);
2240 event
= list_next_entry(event
, event_entry
);
2241 next_event
= list_next_entry(next_event
, event_entry
);
2245 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2246 struct task_struct
*next
)
2248 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2249 struct perf_event_context
*next_ctx
;
2250 struct perf_event_context
*parent
;
2251 struct perf_cpu_context
*cpuctx
;
2257 cpuctx
= __get_cpu_context(ctx
);
2258 if (!cpuctx
->task_ctx
)
2262 parent
= rcu_dereference(ctx
->parent_ctx
);
2263 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2264 if (parent
&& next_ctx
&&
2265 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
2267 * Looks like the two contexts are clones, so we might be
2268 * able to optimize the context switch. We lock both
2269 * contexts and check that they are clones under the
2270 * lock (including re-checking that neither has been
2271 * uncloned in the meantime). It doesn't matter which
2272 * order we take the locks because no other cpu could
2273 * be trying to lock both of these tasks.
2275 raw_spin_lock(&ctx
->lock
);
2276 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2277 if (context_equiv(ctx
, next_ctx
)) {
2279 * XXX do we need a memory barrier of sorts
2280 * wrt to rcu_dereference() of perf_event_ctxp
2282 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2283 next
->perf_event_ctxp
[ctxn
] = ctx
;
2285 next_ctx
->task
= task
;
2288 perf_event_sync_stat(ctx
, next_ctx
);
2290 raw_spin_unlock(&next_ctx
->lock
);
2291 raw_spin_unlock(&ctx
->lock
);
2296 raw_spin_lock(&ctx
->lock
);
2297 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2298 cpuctx
->task_ctx
= NULL
;
2299 raw_spin_unlock(&ctx
->lock
);
2303 #define for_each_task_context_nr(ctxn) \
2304 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2307 * Called from scheduler to remove the events of the current task,
2308 * with interrupts disabled.
2310 * We stop each event and update the event value in event->count.
2312 * This does not protect us against NMI, but disable()
2313 * sets the disabled bit in the control field of event _before_
2314 * accessing the event control register. If a NMI hits, then it will
2315 * not restart the event.
2317 void __perf_event_task_sched_out(struct task_struct
*task
,
2318 struct task_struct
*next
)
2322 for_each_task_context_nr(ctxn
)
2323 perf_event_context_sched_out(task
, ctxn
, next
);
2326 * if cgroup events exist on this CPU, then we need
2327 * to check if we have to switch out PMU state.
2328 * cgroup event are system-wide mode only
2330 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2331 perf_cgroup_sched_out(task
, next
);
2334 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2336 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2338 if (!cpuctx
->task_ctx
)
2341 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2344 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2345 cpuctx
->task_ctx
= NULL
;
2349 * Called with IRQs disabled
2351 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2352 enum event_type_t event_type
)
2354 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2358 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2359 struct perf_cpu_context
*cpuctx
)
2361 struct perf_event
*event
;
2363 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2364 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2366 if (!event_filter_match(event
))
2369 /* may need to reset tstamp_enabled */
2370 if (is_cgroup_event(event
))
2371 perf_cgroup_mark_enabled(event
, ctx
);
2373 if (group_can_go_on(event
, cpuctx
, 1))
2374 group_sched_in(event
, cpuctx
, ctx
);
2377 * If this pinned group hasn't been scheduled,
2378 * put it in error state.
2380 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2381 update_group_times(event
);
2382 event
->state
= PERF_EVENT_STATE_ERROR
;
2388 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2389 struct perf_cpu_context
*cpuctx
)
2391 struct perf_event
*event
;
2394 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2395 /* Ignore events in OFF or ERROR state */
2396 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2399 * Listen to the 'cpu' scheduling filter constraint
2402 if (!event_filter_match(event
))
2405 /* may need to reset tstamp_enabled */
2406 if (is_cgroup_event(event
))
2407 perf_cgroup_mark_enabled(event
, ctx
);
2409 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2410 if (group_sched_in(event
, cpuctx
, ctx
))
2417 ctx_sched_in(struct perf_event_context
*ctx
,
2418 struct perf_cpu_context
*cpuctx
,
2419 enum event_type_t event_type
,
2420 struct task_struct
*task
)
2423 int is_active
= ctx
->is_active
;
2425 ctx
->is_active
|= event_type
;
2426 if (likely(!ctx
->nr_events
))
2430 ctx
->timestamp
= now
;
2431 perf_cgroup_set_timestamp(task
, ctx
);
2433 * First go through the list and put on any pinned groups
2434 * in order to give them the best chance of going on.
2436 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2437 ctx_pinned_sched_in(ctx
, cpuctx
);
2439 /* Then walk through the lower prio flexible groups */
2440 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2441 ctx_flexible_sched_in(ctx
, cpuctx
);
2444 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2445 enum event_type_t event_type
,
2446 struct task_struct
*task
)
2448 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2450 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2453 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2454 struct task_struct
*task
)
2456 struct perf_cpu_context
*cpuctx
;
2458 cpuctx
= __get_cpu_context(ctx
);
2459 if (cpuctx
->task_ctx
== ctx
)
2462 perf_ctx_lock(cpuctx
, ctx
);
2463 perf_pmu_disable(ctx
->pmu
);
2465 * We want to keep the following priority order:
2466 * cpu pinned (that don't need to move), task pinned,
2467 * cpu flexible, task flexible.
2469 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2472 cpuctx
->task_ctx
= ctx
;
2474 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2476 perf_pmu_enable(ctx
->pmu
);
2477 perf_ctx_unlock(cpuctx
, ctx
);
2480 * Since these rotations are per-cpu, we need to ensure the
2481 * cpu-context we got scheduled on is actually rotating.
2483 perf_pmu_rotate_start(ctx
->pmu
);
2487 * When sampling the branck stack in system-wide, it may be necessary
2488 * to flush the stack on context switch. This happens when the branch
2489 * stack does not tag its entries with the pid of the current task.
2490 * Otherwise it becomes impossible to associate a branch entry with a
2491 * task. This ambiguity is more likely to appear when the branch stack
2492 * supports priv level filtering and the user sets it to monitor only
2493 * at the user level (which could be a useful measurement in system-wide
2494 * mode). In that case, the risk is high of having a branch stack with
2495 * branch from multiple tasks. Flushing may mean dropping the existing
2496 * entries or stashing them somewhere in the PMU specific code layer.
2498 * This function provides the context switch callback to the lower code
2499 * layer. It is invoked ONLY when there is at least one system-wide context
2500 * with at least one active event using taken branch sampling.
2502 static void perf_branch_stack_sched_in(struct task_struct
*prev
,
2503 struct task_struct
*task
)
2505 struct perf_cpu_context
*cpuctx
;
2507 unsigned long flags
;
2509 /* no need to flush branch stack if not changing task */
2513 local_irq_save(flags
);
2517 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2518 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2521 * check if the context has at least one
2522 * event using PERF_SAMPLE_BRANCH_STACK
2524 if (cpuctx
->ctx
.nr_branch_stack
> 0
2525 && pmu
->flush_branch_stack
) {
2527 pmu
= cpuctx
->ctx
.pmu
;
2529 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2531 perf_pmu_disable(pmu
);
2533 pmu
->flush_branch_stack();
2535 perf_pmu_enable(pmu
);
2537 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2543 local_irq_restore(flags
);
2547 * Called from scheduler to add the events of the current task
2548 * with interrupts disabled.
2550 * We restore the event value and then enable it.
2552 * This does not protect us against NMI, but enable()
2553 * sets the enabled bit in the control field of event _before_
2554 * accessing the event control register. If a NMI hits, then it will
2555 * keep the event running.
2557 void __perf_event_task_sched_in(struct task_struct
*prev
,
2558 struct task_struct
*task
)
2560 struct perf_event_context
*ctx
;
2563 for_each_task_context_nr(ctxn
) {
2564 ctx
= task
->perf_event_ctxp
[ctxn
];
2568 perf_event_context_sched_in(ctx
, task
);
2571 * if cgroup events exist on this CPU, then we need
2572 * to check if we have to switch in PMU state.
2573 * cgroup event are system-wide mode only
2575 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2576 perf_cgroup_sched_in(prev
, task
);
2578 /* check for system-wide branch_stack events */
2579 if (atomic_read(&__get_cpu_var(perf_branch_stack_events
)))
2580 perf_branch_stack_sched_in(prev
, task
);
2583 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2585 u64 frequency
= event
->attr
.sample_freq
;
2586 u64 sec
= NSEC_PER_SEC
;
2587 u64 divisor
, dividend
;
2589 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2591 count_fls
= fls64(count
);
2592 nsec_fls
= fls64(nsec
);
2593 frequency_fls
= fls64(frequency
);
2597 * We got @count in @nsec, with a target of sample_freq HZ
2598 * the target period becomes:
2601 * period = -------------------
2602 * @nsec * sample_freq
2607 * Reduce accuracy by one bit such that @a and @b converge
2608 * to a similar magnitude.
2610 #define REDUCE_FLS(a, b) \
2612 if (a##_fls > b##_fls) { \
2622 * Reduce accuracy until either term fits in a u64, then proceed with
2623 * the other, so that finally we can do a u64/u64 division.
2625 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2626 REDUCE_FLS(nsec
, frequency
);
2627 REDUCE_FLS(sec
, count
);
2630 if (count_fls
+ sec_fls
> 64) {
2631 divisor
= nsec
* frequency
;
2633 while (count_fls
+ sec_fls
> 64) {
2634 REDUCE_FLS(count
, sec
);
2638 dividend
= count
* sec
;
2640 dividend
= count
* sec
;
2642 while (nsec_fls
+ frequency_fls
> 64) {
2643 REDUCE_FLS(nsec
, frequency
);
2647 divisor
= nsec
* frequency
;
2653 return div64_u64(dividend
, divisor
);
2656 static DEFINE_PER_CPU(int, perf_throttled_count
);
2657 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2659 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2661 struct hw_perf_event
*hwc
= &event
->hw
;
2662 s64 period
, sample_period
;
2665 period
= perf_calculate_period(event
, nsec
, count
);
2667 delta
= (s64
)(period
- hwc
->sample_period
);
2668 delta
= (delta
+ 7) / 8; /* low pass filter */
2670 sample_period
= hwc
->sample_period
+ delta
;
2675 hwc
->sample_period
= sample_period
;
2677 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2679 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2681 local64_set(&hwc
->period_left
, 0);
2684 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2689 * combine freq adjustment with unthrottling to avoid two passes over the
2690 * events. At the same time, make sure, having freq events does not change
2691 * the rate of unthrottling as that would introduce bias.
2693 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2696 struct perf_event
*event
;
2697 struct hw_perf_event
*hwc
;
2698 u64 now
, period
= TICK_NSEC
;
2702 * only need to iterate over all events iff:
2703 * - context have events in frequency mode (needs freq adjust)
2704 * - there are events to unthrottle on this cpu
2706 if (!(ctx
->nr_freq
|| needs_unthr
))
2709 raw_spin_lock(&ctx
->lock
);
2710 perf_pmu_disable(ctx
->pmu
);
2712 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2713 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2716 if (!event_filter_match(event
))
2721 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
2722 hwc
->interrupts
= 0;
2723 perf_log_throttle(event
, 1);
2724 event
->pmu
->start(event
, 0);
2727 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2731 * stop the event and update event->count
2733 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2735 now
= local64_read(&event
->count
);
2736 delta
= now
- hwc
->freq_count_stamp
;
2737 hwc
->freq_count_stamp
= now
;
2741 * reload only if value has changed
2742 * we have stopped the event so tell that
2743 * to perf_adjust_period() to avoid stopping it
2747 perf_adjust_period(event
, period
, delta
, false);
2749 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
2752 perf_pmu_enable(ctx
->pmu
);
2753 raw_spin_unlock(&ctx
->lock
);
2757 * Round-robin a context's events:
2759 static void rotate_ctx(struct perf_event_context
*ctx
)
2762 * Rotate the first entry last of non-pinned groups. Rotation might be
2763 * disabled by the inheritance code.
2765 if (!ctx
->rotate_disable
)
2766 list_rotate_left(&ctx
->flexible_groups
);
2770 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2771 * because they're strictly cpu affine and rotate_start is called with IRQs
2772 * disabled, while rotate_context is called from IRQ context.
2774 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2776 struct perf_event_context
*ctx
= NULL
;
2777 int rotate
= 0, remove
= 1;
2779 if (cpuctx
->ctx
.nr_events
) {
2781 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2785 ctx
= cpuctx
->task_ctx
;
2786 if (ctx
&& ctx
->nr_events
) {
2788 if (ctx
->nr_events
!= ctx
->nr_active
)
2795 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2796 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2798 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2800 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
2802 rotate_ctx(&cpuctx
->ctx
);
2806 perf_event_sched_in(cpuctx
, ctx
, current
);
2808 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2809 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2812 list_del_init(&cpuctx
->rotation_list
);
2817 #ifdef CONFIG_NO_HZ_FULL
2818 bool perf_event_can_stop_tick(void)
2820 if (atomic_read(&nr_freq_events
) ||
2821 __this_cpu_read(perf_throttled_count
))
2828 void perf_event_task_tick(void)
2830 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2831 struct perf_cpu_context
*cpuctx
, *tmp
;
2832 struct perf_event_context
*ctx
;
2835 WARN_ON(!irqs_disabled());
2837 __this_cpu_inc(perf_throttled_seq
);
2838 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
2840 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2842 perf_adjust_freq_unthr_context(ctx
, throttled
);
2844 ctx
= cpuctx
->task_ctx
;
2846 perf_adjust_freq_unthr_context(ctx
, throttled
);
2850 static int event_enable_on_exec(struct perf_event
*event
,
2851 struct perf_event_context
*ctx
)
2853 if (!event
->attr
.enable_on_exec
)
2856 event
->attr
.enable_on_exec
= 0;
2857 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2860 __perf_event_mark_enabled(event
);
2866 * Enable all of a task's events that have been marked enable-on-exec.
2867 * This expects task == current.
2869 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2871 struct perf_event
*event
;
2872 unsigned long flags
;
2876 local_irq_save(flags
);
2877 if (!ctx
|| !ctx
->nr_events
)
2881 * We must ctxsw out cgroup events to avoid conflict
2882 * when invoking perf_task_event_sched_in() later on
2883 * in this function. Otherwise we end up trying to
2884 * ctxswin cgroup events which are already scheduled
2887 perf_cgroup_sched_out(current
, NULL
);
2889 raw_spin_lock(&ctx
->lock
);
2890 task_ctx_sched_out(ctx
);
2892 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
2893 ret
= event_enable_on_exec(event
, ctx
);
2899 * Unclone this context if we enabled any event.
2904 raw_spin_unlock(&ctx
->lock
);
2907 * Also calls ctxswin for cgroup events, if any:
2909 perf_event_context_sched_in(ctx
, ctx
->task
);
2911 local_irq_restore(flags
);
2915 * Cross CPU call to read the hardware event
2917 static void __perf_event_read(void *info
)
2919 struct perf_event
*event
= info
;
2920 struct perf_event_context
*ctx
= event
->ctx
;
2921 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2924 * If this is a task context, we need to check whether it is
2925 * the current task context of this cpu. If not it has been
2926 * scheduled out before the smp call arrived. In that case
2927 * event->count would have been updated to a recent sample
2928 * when the event was scheduled out.
2930 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2933 raw_spin_lock(&ctx
->lock
);
2934 if (ctx
->is_active
) {
2935 update_context_time(ctx
);
2936 update_cgrp_time_from_event(event
);
2938 update_event_times(event
);
2939 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2940 event
->pmu
->read(event
);
2941 raw_spin_unlock(&ctx
->lock
);
2944 static inline u64
perf_event_count(struct perf_event
*event
)
2946 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2949 static u64
perf_event_read(struct perf_event
*event
)
2952 * If event is enabled and currently active on a CPU, update the
2953 * value in the event structure:
2955 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2956 smp_call_function_single(event
->oncpu
,
2957 __perf_event_read
, event
, 1);
2958 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2959 struct perf_event_context
*ctx
= event
->ctx
;
2960 unsigned long flags
;
2962 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2964 * may read while context is not active
2965 * (e.g., thread is blocked), in that case
2966 * we cannot update context time
2968 if (ctx
->is_active
) {
2969 update_context_time(ctx
);
2970 update_cgrp_time_from_event(event
);
2972 update_event_times(event
);
2973 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2976 return perf_event_count(event
);
2980 * Initialize the perf_event context in a task_struct:
2982 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2984 raw_spin_lock_init(&ctx
->lock
);
2985 mutex_init(&ctx
->mutex
);
2986 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2987 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2988 INIT_LIST_HEAD(&ctx
->event_list
);
2989 atomic_set(&ctx
->refcount
, 1);
2992 static struct perf_event_context
*
2993 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2995 struct perf_event_context
*ctx
;
2997 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3001 __perf_event_init_context(ctx
);
3004 get_task_struct(task
);
3011 static struct task_struct
*
3012 find_lively_task_by_vpid(pid_t vpid
)
3014 struct task_struct
*task
;
3021 task
= find_task_by_vpid(vpid
);
3023 get_task_struct(task
);
3027 return ERR_PTR(-ESRCH
);
3029 /* Reuse ptrace permission checks for now. */
3031 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3036 put_task_struct(task
);
3037 return ERR_PTR(err
);
3042 * Returns a matching context with refcount and pincount.
3044 static struct perf_event_context
*
3045 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
3047 struct perf_event_context
*ctx
;
3048 struct perf_cpu_context
*cpuctx
;
3049 unsigned long flags
;
3053 /* Must be root to operate on a CPU event: */
3054 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3055 return ERR_PTR(-EACCES
);
3058 * We could be clever and allow to attach a event to an
3059 * offline CPU and activate it when the CPU comes up, but
3062 if (!cpu_online(cpu
))
3063 return ERR_PTR(-ENODEV
);
3065 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3074 ctxn
= pmu
->task_ctx_nr
;
3079 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3083 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3085 ctx
= alloc_perf_context(pmu
, task
);
3091 mutex_lock(&task
->perf_event_mutex
);
3093 * If it has already passed perf_event_exit_task().
3094 * we must see PF_EXITING, it takes this mutex too.
3096 if (task
->flags
& PF_EXITING
)
3098 else if (task
->perf_event_ctxp
[ctxn
])
3103 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3105 mutex_unlock(&task
->perf_event_mutex
);
3107 if (unlikely(err
)) {
3119 return ERR_PTR(err
);
3122 static void perf_event_free_filter(struct perf_event
*event
);
3124 static void free_event_rcu(struct rcu_head
*head
)
3126 struct perf_event
*event
;
3128 event
= container_of(head
, struct perf_event
, rcu_head
);
3130 put_pid_ns(event
->ns
);
3131 perf_event_free_filter(event
);
3135 static void ring_buffer_put(struct ring_buffer
*rb
);
3136 static void ring_buffer_detach(struct perf_event
*event
, struct ring_buffer
*rb
);
3138 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3143 if (has_branch_stack(event
)) {
3144 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
3145 atomic_dec(&per_cpu(perf_branch_stack_events
, cpu
));
3147 if (is_cgroup_event(event
))
3148 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3151 static void unaccount_event(struct perf_event
*event
)
3156 if (event
->attach_state
& PERF_ATTACH_TASK
)
3157 static_key_slow_dec_deferred(&perf_sched_events
);
3158 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3159 atomic_dec(&nr_mmap_events
);
3160 if (event
->attr
.comm
)
3161 atomic_dec(&nr_comm_events
);
3162 if (event
->attr
.task
)
3163 atomic_dec(&nr_task_events
);
3164 if (event
->attr
.freq
)
3165 atomic_dec(&nr_freq_events
);
3166 if (is_cgroup_event(event
))
3167 static_key_slow_dec_deferred(&perf_sched_events
);
3168 if (has_branch_stack(event
))
3169 static_key_slow_dec_deferred(&perf_sched_events
);
3171 unaccount_event_cpu(event
, event
->cpu
);
3174 static void __free_event(struct perf_event
*event
)
3176 if (!event
->parent
) {
3177 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3178 put_callchain_buffers();
3182 event
->destroy(event
);
3185 put_ctx(event
->ctx
);
3187 call_rcu(&event
->rcu_head
, free_event_rcu
);
3189 static void free_event(struct perf_event
*event
)
3191 irq_work_sync(&event
->pending
);
3193 unaccount_event(event
);
3196 struct ring_buffer
*rb
;
3199 * Can happen when we close an event with re-directed output.
3201 * Since we have a 0 refcount, perf_mmap_close() will skip
3202 * over us; possibly making our ring_buffer_put() the last.
3204 mutex_lock(&event
->mmap_mutex
);
3207 rcu_assign_pointer(event
->rb
, NULL
);
3208 ring_buffer_detach(event
, rb
);
3209 ring_buffer_put(rb
); /* could be last */
3211 mutex_unlock(&event
->mmap_mutex
);
3214 if (is_cgroup_event(event
))
3215 perf_detach_cgroup(event
);
3218 __free_event(event
);
3221 int perf_event_release_kernel(struct perf_event
*event
)
3223 struct perf_event_context
*ctx
= event
->ctx
;
3225 WARN_ON_ONCE(ctx
->parent_ctx
);
3227 * There are two ways this annotation is useful:
3229 * 1) there is a lock recursion from perf_event_exit_task
3230 * see the comment there.
3232 * 2) there is a lock-inversion with mmap_sem through
3233 * perf_event_read_group(), which takes faults while
3234 * holding ctx->mutex, however this is called after
3235 * the last filedesc died, so there is no possibility
3236 * to trigger the AB-BA case.
3238 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
3239 raw_spin_lock_irq(&ctx
->lock
);
3240 perf_group_detach(event
);
3241 raw_spin_unlock_irq(&ctx
->lock
);
3242 perf_remove_from_context(event
);
3243 mutex_unlock(&ctx
->mutex
);
3249 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3252 * Called when the last reference to the file is gone.
3254 static void put_event(struct perf_event
*event
)
3256 struct task_struct
*owner
;
3258 if (!atomic_long_dec_and_test(&event
->refcount
))
3262 owner
= ACCESS_ONCE(event
->owner
);
3264 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3265 * !owner it means the list deletion is complete and we can indeed
3266 * free this event, otherwise we need to serialize on
3267 * owner->perf_event_mutex.
3269 smp_read_barrier_depends();
3272 * Since delayed_put_task_struct() also drops the last
3273 * task reference we can safely take a new reference
3274 * while holding the rcu_read_lock().
3276 get_task_struct(owner
);
3281 mutex_lock(&owner
->perf_event_mutex
);
3283 * We have to re-check the event->owner field, if it is cleared
3284 * we raced with perf_event_exit_task(), acquiring the mutex
3285 * ensured they're done, and we can proceed with freeing the
3289 list_del_init(&event
->owner_entry
);
3290 mutex_unlock(&owner
->perf_event_mutex
);
3291 put_task_struct(owner
);
3294 perf_event_release_kernel(event
);
3297 static int perf_release(struct inode
*inode
, struct file
*file
)
3299 put_event(file
->private_data
);
3303 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3305 struct perf_event
*child
;
3311 mutex_lock(&event
->child_mutex
);
3312 total
+= perf_event_read(event
);
3313 *enabled
+= event
->total_time_enabled
+
3314 atomic64_read(&event
->child_total_time_enabled
);
3315 *running
+= event
->total_time_running
+
3316 atomic64_read(&event
->child_total_time_running
);
3318 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3319 total
+= perf_event_read(child
);
3320 *enabled
+= child
->total_time_enabled
;
3321 *running
+= child
->total_time_running
;
3323 mutex_unlock(&event
->child_mutex
);
3327 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3329 static int perf_event_read_group(struct perf_event
*event
,
3330 u64 read_format
, char __user
*buf
)
3332 struct perf_event
*leader
= event
->group_leader
, *sub
;
3333 int n
= 0, size
= 0, ret
= -EFAULT
;
3334 struct perf_event_context
*ctx
= leader
->ctx
;
3336 u64 count
, enabled
, running
;
3338 mutex_lock(&ctx
->mutex
);
3339 count
= perf_event_read_value(leader
, &enabled
, &running
);
3341 values
[n
++] = 1 + leader
->nr_siblings
;
3342 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3343 values
[n
++] = enabled
;
3344 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3345 values
[n
++] = running
;
3346 values
[n
++] = count
;
3347 if (read_format
& PERF_FORMAT_ID
)
3348 values
[n
++] = primary_event_id(leader
);
3350 size
= n
* sizeof(u64
);
3352 if (copy_to_user(buf
, values
, size
))
3357 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3360 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3361 if (read_format
& PERF_FORMAT_ID
)
3362 values
[n
++] = primary_event_id(sub
);
3364 size
= n
* sizeof(u64
);
3366 if (copy_to_user(buf
+ ret
, values
, size
)) {
3374 mutex_unlock(&ctx
->mutex
);
3379 static int perf_event_read_one(struct perf_event
*event
,
3380 u64 read_format
, char __user
*buf
)
3382 u64 enabled
, running
;
3386 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3387 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3388 values
[n
++] = enabled
;
3389 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3390 values
[n
++] = running
;
3391 if (read_format
& PERF_FORMAT_ID
)
3392 values
[n
++] = primary_event_id(event
);
3394 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3397 return n
* sizeof(u64
);
3401 * Read the performance event - simple non blocking version for now
3404 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3406 u64 read_format
= event
->attr
.read_format
;
3410 * Return end-of-file for a read on a event that is in
3411 * error state (i.e. because it was pinned but it couldn't be
3412 * scheduled on to the CPU at some point).
3414 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3417 if (count
< event
->read_size
)
3420 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3421 if (read_format
& PERF_FORMAT_GROUP
)
3422 ret
= perf_event_read_group(event
, read_format
, buf
);
3424 ret
= perf_event_read_one(event
, read_format
, buf
);
3430 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3432 struct perf_event
*event
= file
->private_data
;
3434 return perf_read_hw(event
, buf
, count
);
3437 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3439 struct perf_event
*event
= file
->private_data
;
3440 struct ring_buffer
*rb
;
3441 unsigned int events
= POLL_HUP
;
3444 * Pin the event->rb by taking event->mmap_mutex; otherwise
3445 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
3447 mutex_lock(&event
->mmap_mutex
);
3450 events
= atomic_xchg(&rb
->poll
, 0);
3451 mutex_unlock(&event
->mmap_mutex
);
3453 poll_wait(file
, &event
->waitq
, wait
);
3458 static void perf_event_reset(struct perf_event
*event
)
3460 (void)perf_event_read(event
);
3461 local64_set(&event
->count
, 0);
3462 perf_event_update_userpage(event
);
3466 * Holding the top-level event's child_mutex means that any
3467 * descendant process that has inherited this event will block
3468 * in sync_child_event if it goes to exit, thus satisfying the
3469 * task existence requirements of perf_event_enable/disable.
3471 static void perf_event_for_each_child(struct perf_event
*event
,
3472 void (*func
)(struct perf_event
*))
3474 struct perf_event
*child
;
3476 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3477 mutex_lock(&event
->child_mutex
);
3479 list_for_each_entry(child
, &event
->child_list
, child_list
)
3481 mutex_unlock(&event
->child_mutex
);
3484 static void perf_event_for_each(struct perf_event
*event
,
3485 void (*func
)(struct perf_event
*))
3487 struct perf_event_context
*ctx
= event
->ctx
;
3488 struct perf_event
*sibling
;
3490 WARN_ON_ONCE(ctx
->parent_ctx
);
3491 mutex_lock(&ctx
->mutex
);
3492 event
= event
->group_leader
;
3494 perf_event_for_each_child(event
, func
);
3495 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3496 perf_event_for_each_child(sibling
, func
);
3497 mutex_unlock(&ctx
->mutex
);
3500 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3502 struct perf_event_context
*ctx
= event
->ctx
;
3506 if (!is_sampling_event(event
))
3509 if (copy_from_user(&value
, arg
, sizeof(value
)))
3515 raw_spin_lock_irq(&ctx
->lock
);
3516 if (event
->attr
.freq
) {
3517 if (value
> sysctl_perf_event_sample_rate
) {
3522 event
->attr
.sample_freq
= value
;
3524 event
->attr
.sample_period
= value
;
3525 event
->hw
.sample_period
= value
;
3528 raw_spin_unlock_irq(&ctx
->lock
);
3533 static const struct file_operations perf_fops
;
3535 static inline int perf_fget_light(int fd
, struct fd
*p
)
3537 struct fd f
= fdget(fd
);
3541 if (f
.file
->f_op
!= &perf_fops
) {
3549 static int perf_event_set_output(struct perf_event
*event
,
3550 struct perf_event
*output_event
);
3551 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3553 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3555 struct perf_event
*event
= file
->private_data
;
3556 void (*func
)(struct perf_event
*);
3560 case PERF_EVENT_IOC_ENABLE
:
3561 func
= perf_event_enable
;
3563 case PERF_EVENT_IOC_DISABLE
:
3564 func
= perf_event_disable
;
3566 case PERF_EVENT_IOC_RESET
:
3567 func
= perf_event_reset
;
3570 case PERF_EVENT_IOC_REFRESH
:
3571 return perf_event_refresh(event
, arg
);
3573 case PERF_EVENT_IOC_PERIOD
:
3574 return perf_event_period(event
, (u64 __user
*)arg
);
3576 case PERF_EVENT_IOC_ID
:
3578 u64 id
= primary_event_id(event
);
3580 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
3585 case PERF_EVENT_IOC_SET_OUTPUT
:
3589 struct perf_event
*output_event
;
3591 ret
= perf_fget_light(arg
, &output
);
3594 output_event
= output
.file
->private_data
;
3595 ret
= perf_event_set_output(event
, output_event
);
3598 ret
= perf_event_set_output(event
, NULL
);
3603 case PERF_EVENT_IOC_SET_FILTER
:
3604 return perf_event_set_filter(event
, (void __user
*)arg
);
3610 if (flags
& PERF_IOC_FLAG_GROUP
)
3611 perf_event_for_each(event
, func
);
3613 perf_event_for_each_child(event
, func
);
3618 int perf_event_task_enable(void)
3620 struct perf_event
*event
;
3622 mutex_lock(¤t
->perf_event_mutex
);
3623 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3624 perf_event_for_each_child(event
, perf_event_enable
);
3625 mutex_unlock(¤t
->perf_event_mutex
);
3630 int perf_event_task_disable(void)
3632 struct perf_event
*event
;
3634 mutex_lock(¤t
->perf_event_mutex
);
3635 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3636 perf_event_for_each_child(event
, perf_event_disable
);
3637 mutex_unlock(¤t
->perf_event_mutex
);
3642 static int perf_event_index(struct perf_event
*event
)
3644 if (event
->hw
.state
& PERF_HES_STOPPED
)
3647 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3650 return event
->pmu
->event_idx(event
);
3653 static void calc_timer_values(struct perf_event
*event
,
3660 *now
= perf_clock();
3661 ctx_time
= event
->shadow_ctx_time
+ *now
;
3662 *enabled
= ctx_time
- event
->tstamp_enabled
;
3663 *running
= ctx_time
- event
->tstamp_running
;
3666 static void perf_event_init_userpage(struct perf_event
*event
)
3668 struct perf_event_mmap_page
*userpg
;
3669 struct ring_buffer
*rb
;
3672 rb
= rcu_dereference(event
->rb
);
3676 userpg
= rb
->user_page
;
3678 /* Allow new userspace to detect that bit 0 is deprecated */
3679 userpg
->cap_bit0_is_deprecated
= 1;
3680 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
3686 void __weak
arch_perf_update_userpage(struct perf_event_mmap_page
*userpg
, u64 now
)
3691 * Callers need to ensure there can be no nesting of this function, otherwise
3692 * the seqlock logic goes bad. We can not serialize this because the arch
3693 * code calls this from NMI context.
3695 void perf_event_update_userpage(struct perf_event
*event
)
3697 struct perf_event_mmap_page
*userpg
;
3698 struct ring_buffer
*rb
;
3699 u64 enabled
, running
, now
;
3702 rb
= rcu_dereference(event
->rb
);
3707 * compute total_time_enabled, total_time_running
3708 * based on snapshot values taken when the event
3709 * was last scheduled in.
3711 * we cannot simply called update_context_time()
3712 * because of locking issue as we can be called in
3715 calc_timer_values(event
, &now
, &enabled
, &running
);
3717 userpg
= rb
->user_page
;
3719 * Disable preemption so as to not let the corresponding user-space
3720 * spin too long if we get preempted.
3725 userpg
->index
= perf_event_index(event
);
3726 userpg
->offset
= perf_event_count(event
);
3728 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3730 userpg
->time_enabled
= enabled
+
3731 atomic64_read(&event
->child_total_time_enabled
);
3733 userpg
->time_running
= running
+
3734 atomic64_read(&event
->child_total_time_running
);
3736 arch_perf_update_userpage(userpg
, now
);
3745 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3747 struct perf_event
*event
= vma
->vm_file
->private_data
;
3748 struct ring_buffer
*rb
;
3749 int ret
= VM_FAULT_SIGBUS
;
3751 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3752 if (vmf
->pgoff
== 0)
3758 rb
= rcu_dereference(event
->rb
);
3762 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3765 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3769 get_page(vmf
->page
);
3770 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3771 vmf
->page
->index
= vmf
->pgoff
;
3780 static void ring_buffer_attach(struct perf_event
*event
,
3781 struct ring_buffer
*rb
)
3783 unsigned long flags
;
3785 if (!list_empty(&event
->rb_entry
))
3788 spin_lock_irqsave(&rb
->event_lock
, flags
);
3789 if (list_empty(&event
->rb_entry
))
3790 list_add(&event
->rb_entry
, &rb
->event_list
);
3791 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3794 static void ring_buffer_detach(struct perf_event
*event
, struct ring_buffer
*rb
)
3796 unsigned long flags
;
3798 if (list_empty(&event
->rb_entry
))
3801 spin_lock_irqsave(&rb
->event_lock
, flags
);
3802 list_del_init(&event
->rb_entry
);
3803 wake_up_all(&event
->waitq
);
3804 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3807 static void ring_buffer_wakeup(struct perf_event
*event
)
3809 struct ring_buffer
*rb
;
3812 rb
= rcu_dereference(event
->rb
);
3814 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
3815 wake_up_all(&event
->waitq
);
3820 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3822 struct ring_buffer
*rb
;
3824 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3828 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3830 struct ring_buffer
*rb
;
3833 rb
= rcu_dereference(event
->rb
);
3835 if (!atomic_inc_not_zero(&rb
->refcount
))
3843 static void ring_buffer_put(struct ring_buffer
*rb
)
3845 if (!atomic_dec_and_test(&rb
->refcount
))
3848 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
3850 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3853 static void perf_mmap_open(struct vm_area_struct
*vma
)
3855 struct perf_event
*event
= vma
->vm_file
->private_data
;
3857 atomic_inc(&event
->mmap_count
);
3858 atomic_inc(&event
->rb
->mmap_count
);
3862 * A buffer can be mmap()ed multiple times; either directly through the same
3863 * event, or through other events by use of perf_event_set_output().
3865 * In order to undo the VM accounting done by perf_mmap() we need to destroy
3866 * the buffer here, where we still have a VM context. This means we need
3867 * to detach all events redirecting to us.
3869 static void perf_mmap_close(struct vm_area_struct
*vma
)
3871 struct perf_event
*event
= vma
->vm_file
->private_data
;
3873 struct ring_buffer
*rb
= event
->rb
;
3874 struct user_struct
*mmap_user
= rb
->mmap_user
;
3875 int mmap_locked
= rb
->mmap_locked
;
3876 unsigned long size
= perf_data_size(rb
);
3878 atomic_dec(&rb
->mmap_count
);
3880 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
3883 /* Detach current event from the buffer. */
3884 rcu_assign_pointer(event
->rb
, NULL
);
3885 ring_buffer_detach(event
, rb
);
3886 mutex_unlock(&event
->mmap_mutex
);
3888 /* If there's still other mmap()s of this buffer, we're done. */
3889 if (atomic_read(&rb
->mmap_count
)) {
3890 ring_buffer_put(rb
); /* can't be last */
3895 * No other mmap()s, detach from all other events that might redirect
3896 * into the now unreachable buffer. Somewhat complicated by the
3897 * fact that rb::event_lock otherwise nests inside mmap_mutex.
3901 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
3902 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
3904 * This event is en-route to free_event() which will
3905 * detach it and remove it from the list.
3911 mutex_lock(&event
->mmap_mutex
);
3913 * Check we didn't race with perf_event_set_output() which can
3914 * swizzle the rb from under us while we were waiting to
3915 * acquire mmap_mutex.
3917 * If we find a different rb; ignore this event, a next
3918 * iteration will no longer find it on the list. We have to
3919 * still restart the iteration to make sure we're not now
3920 * iterating the wrong list.
3922 if (event
->rb
== rb
) {
3923 rcu_assign_pointer(event
->rb
, NULL
);
3924 ring_buffer_detach(event
, rb
);
3925 ring_buffer_put(rb
); /* can't be last, we still have one */
3927 mutex_unlock(&event
->mmap_mutex
);
3931 * Restart the iteration; either we're on the wrong list or
3932 * destroyed its integrity by doing a deletion.
3939 * It could be there's still a few 0-ref events on the list; they'll
3940 * get cleaned up by free_event() -- they'll also still have their
3941 * ref on the rb and will free it whenever they are done with it.
3943 * Aside from that, this buffer is 'fully' detached and unmapped,
3944 * undo the VM accounting.
3947 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
3948 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
3949 free_uid(mmap_user
);
3951 ring_buffer_put(rb
); /* could be last */
3954 static const struct vm_operations_struct perf_mmap_vmops
= {
3955 .open
= perf_mmap_open
,
3956 .close
= perf_mmap_close
,
3957 .fault
= perf_mmap_fault
,
3958 .page_mkwrite
= perf_mmap_fault
,
3961 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3963 struct perf_event
*event
= file
->private_data
;
3964 unsigned long user_locked
, user_lock_limit
;
3965 struct user_struct
*user
= current_user();
3966 unsigned long locked
, lock_limit
;
3967 struct ring_buffer
*rb
;
3968 unsigned long vma_size
;
3969 unsigned long nr_pages
;
3970 long user_extra
, extra
;
3971 int ret
= 0, flags
= 0;
3974 * Don't allow mmap() of inherited per-task counters. This would
3975 * create a performance issue due to all children writing to the
3978 if (event
->cpu
== -1 && event
->attr
.inherit
)
3981 if (!(vma
->vm_flags
& VM_SHARED
))
3984 vma_size
= vma
->vm_end
- vma
->vm_start
;
3985 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3988 * If we have rb pages ensure they're a power-of-two number, so we
3989 * can do bitmasks instead of modulo.
3991 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3994 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3997 if (vma
->vm_pgoff
!= 0)
4000 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4002 mutex_lock(&event
->mmap_mutex
);
4004 if (event
->rb
->nr_pages
!= nr_pages
) {
4009 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4011 * Raced against perf_mmap_close() through
4012 * perf_event_set_output(). Try again, hope for better
4015 mutex_unlock(&event
->mmap_mutex
);
4022 user_extra
= nr_pages
+ 1;
4023 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4026 * Increase the limit linearly with more CPUs:
4028 user_lock_limit
*= num_online_cpus();
4030 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4033 if (user_locked
> user_lock_limit
)
4034 extra
= user_locked
- user_lock_limit
;
4036 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4037 lock_limit
>>= PAGE_SHIFT
;
4038 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4040 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4041 !capable(CAP_IPC_LOCK
)) {
4048 if (vma
->vm_flags
& VM_WRITE
)
4049 flags
|= RING_BUFFER_WRITABLE
;
4051 rb
= rb_alloc(nr_pages
,
4052 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4060 atomic_set(&rb
->mmap_count
, 1);
4061 rb
->mmap_locked
= extra
;
4062 rb
->mmap_user
= get_current_user();
4064 atomic_long_add(user_extra
, &user
->locked_vm
);
4065 vma
->vm_mm
->pinned_vm
+= extra
;
4067 ring_buffer_attach(event
, rb
);
4068 rcu_assign_pointer(event
->rb
, rb
);
4070 perf_event_init_userpage(event
);
4071 perf_event_update_userpage(event
);
4075 atomic_inc(&event
->mmap_count
);
4076 mutex_unlock(&event
->mmap_mutex
);
4079 * Since pinned accounting is per vm we cannot allow fork() to copy our
4082 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4083 vma
->vm_ops
= &perf_mmap_vmops
;
4088 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4090 struct inode
*inode
= file_inode(filp
);
4091 struct perf_event
*event
= filp
->private_data
;
4094 mutex_lock(&inode
->i_mutex
);
4095 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4096 mutex_unlock(&inode
->i_mutex
);
4104 static const struct file_operations perf_fops
= {
4105 .llseek
= no_llseek
,
4106 .release
= perf_release
,
4109 .unlocked_ioctl
= perf_ioctl
,
4110 .compat_ioctl
= perf_ioctl
,
4112 .fasync
= perf_fasync
,
4118 * If there's data, ensure we set the poll() state and publish everything
4119 * to user-space before waking everybody up.
4122 void perf_event_wakeup(struct perf_event
*event
)
4124 ring_buffer_wakeup(event
);
4126 if (event
->pending_kill
) {
4127 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
4128 event
->pending_kill
= 0;
4132 static void perf_pending_event(struct irq_work
*entry
)
4134 struct perf_event
*event
= container_of(entry
,
4135 struct perf_event
, pending
);
4137 if (event
->pending_disable
) {
4138 event
->pending_disable
= 0;
4139 __perf_event_disable(event
);
4142 if (event
->pending_wakeup
) {
4143 event
->pending_wakeup
= 0;
4144 perf_event_wakeup(event
);
4149 * We assume there is only KVM supporting the callbacks.
4150 * Later on, we might change it to a list if there is
4151 * another virtualization implementation supporting the callbacks.
4153 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4155 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4157 perf_guest_cbs
= cbs
;
4160 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4162 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4164 perf_guest_cbs
= NULL
;
4167 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4170 perf_output_sample_regs(struct perf_output_handle
*handle
,
4171 struct pt_regs
*regs
, u64 mask
)
4175 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4176 sizeof(mask
) * BITS_PER_BYTE
) {
4179 val
= perf_reg_value(regs
, bit
);
4180 perf_output_put(handle
, val
);
4184 static void perf_sample_regs_user(struct perf_regs_user
*regs_user
,
4185 struct pt_regs
*regs
)
4187 if (!user_mode(regs
)) {
4189 regs
= task_pt_regs(current
);
4195 regs_user
->regs
= regs
;
4196 regs_user
->abi
= perf_reg_abi(current
);
4201 * Get remaining task size from user stack pointer.
4203 * It'd be better to take stack vma map and limit this more
4204 * precisly, but there's no way to get it safely under interrupt,
4205 * so using TASK_SIZE as limit.
4207 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
4209 unsigned long addr
= perf_user_stack_pointer(regs
);
4211 if (!addr
|| addr
>= TASK_SIZE
)
4214 return TASK_SIZE
- addr
;
4218 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
4219 struct pt_regs
*regs
)
4223 /* No regs, no stack pointer, no dump. */
4228 * Check if we fit in with the requested stack size into the:
4230 * If we don't, we limit the size to the TASK_SIZE.
4232 * - remaining sample size
4233 * If we don't, we customize the stack size to
4234 * fit in to the remaining sample size.
4237 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
4238 stack_size
= min(stack_size
, (u16
) task_size
);
4240 /* Current header size plus static size and dynamic size. */
4241 header_size
+= 2 * sizeof(u64
);
4243 /* Do we fit in with the current stack dump size? */
4244 if ((u16
) (header_size
+ stack_size
) < header_size
) {
4246 * If we overflow the maximum size for the sample,
4247 * we customize the stack dump size to fit in.
4249 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
4250 stack_size
= round_up(stack_size
, sizeof(u64
));
4257 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
4258 struct pt_regs
*regs
)
4260 /* Case of a kernel thread, nothing to dump */
4263 perf_output_put(handle
, size
);
4272 * - the size requested by user or the best one we can fit
4273 * in to the sample max size
4275 * - user stack dump data
4277 * - the actual dumped size
4281 perf_output_put(handle
, dump_size
);
4284 sp
= perf_user_stack_pointer(regs
);
4285 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
4286 dyn_size
= dump_size
- rem
;
4288 perf_output_skip(handle
, rem
);
4291 perf_output_put(handle
, dyn_size
);
4295 static void __perf_event_header__init_id(struct perf_event_header
*header
,
4296 struct perf_sample_data
*data
,
4297 struct perf_event
*event
)
4299 u64 sample_type
= event
->attr
.sample_type
;
4301 data
->type
= sample_type
;
4302 header
->size
+= event
->id_header_size
;
4304 if (sample_type
& PERF_SAMPLE_TID
) {
4305 /* namespace issues */
4306 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
4307 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
4310 if (sample_type
& PERF_SAMPLE_TIME
)
4311 data
->time
= perf_clock();
4313 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
4314 data
->id
= primary_event_id(event
);
4316 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4317 data
->stream_id
= event
->id
;
4319 if (sample_type
& PERF_SAMPLE_CPU
) {
4320 data
->cpu_entry
.cpu
= raw_smp_processor_id();
4321 data
->cpu_entry
.reserved
= 0;
4325 void perf_event_header__init_id(struct perf_event_header
*header
,
4326 struct perf_sample_data
*data
,
4327 struct perf_event
*event
)
4329 if (event
->attr
.sample_id_all
)
4330 __perf_event_header__init_id(header
, data
, event
);
4333 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
4334 struct perf_sample_data
*data
)
4336 u64 sample_type
= data
->type
;
4338 if (sample_type
& PERF_SAMPLE_TID
)
4339 perf_output_put(handle
, data
->tid_entry
);
4341 if (sample_type
& PERF_SAMPLE_TIME
)
4342 perf_output_put(handle
, data
->time
);
4344 if (sample_type
& PERF_SAMPLE_ID
)
4345 perf_output_put(handle
, data
->id
);
4347 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4348 perf_output_put(handle
, data
->stream_id
);
4350 if (sample_type
& PERF_SAMPLE_CPU
)
4351 perf_output_put(handle
, data
->cpu_entry
);
4353 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
4354 perf_output_put(handle
, data
->id
);
4357 void perf_event__output_id_sample(struct perf_event
*event
,
4358 struct perf_output_handle
*handle
,
4359 struct perf_sample_data
*sample
)
4361 if (event
->attr
.sample_id_all
)
4362 __perf_event__output_id_sample(handle
, sample
);
4365 static void perf_output_read_one(struct perf_output_handle
*handle
,
4366 struct perf_event
*event
,
4367 u64 enabled
, u64 running
)
4369 u64 read_format
= event
->attr
.read_format
;
4373 values
[n
++] = perf_event_count(event
);
4374 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4375 values
[n
++] = enabled
+
4376 atomic64_read(&event
->child_total_time_enabled
);
4378 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4379 values
[n
++] = running
+
4380 atomic64_read(&event
->child_total_time_running
);
4382 if (read_format
& PERF_FORMAT_ID
)
4383 values
[n
++] = primary_event_id(event
);
4385 __output_copy(handle
, values
, n
* sizeof(u64
));
4389 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
4391 static void perf_output_read_group(struct perf_output_handle
*handle
,
4392 struct perf_event
*event
,
4393 u64 enabled
, u64 running
)
4395 struct perf_event
*leader
= event
->group_leader
, *sub
;
4396 u64 read_format
= event
->attr
.read_format
;
4400 values
[n
++] = 1 + leader
->nr_siblings
;
4402 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4403 values
[n
++] = enabled
;
4405 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4406 values
[n
++] = running
;
4408 if (leader
!= event
)
4409 leader
->pmu
->read(leader
);
4411 values
[n
++] = perf_event_count(leader
);
4412 if (read_format
& PERF_FORMAT_ID
)
4413 values
[n
++] = primary_event_id(leader
);
4415 __output_copy(handle
, values
, n
* sizeof(u64
));
4417 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4420 if ((sub
!= event
) &&
4421 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
4422 sub
->pmu
->read(sub
);
4424 values
[n
++] = perf_event_count(sub
);
4425 if (read_format
& PERF_FORMAT_ID
)
4426 values
[n
++] = primary_event_id(sub
);
4428 __output_copy(handle
, values
, n
* sizeof(u64
));
4432 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
4433 PERF_FORMAT_TOTAL_TIME_RUNNING)
4435 static void perf_output_read(struct perf_output_handle
*handle
,
4436 struct perf_event
*event
)
4438 u64 enabled
= 0, running
= 0, now
;
4439 u64 read_format
= event
->attr
.read_format
;
4442 * compute total_time_enabled, total_time_running
4443 * based on snapshot values taken when the event
4444 * was last scheduled in.
4446 * we cannot simply called update_context_time()
4447 * because of locking issue as we are called in
4450 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
4451 calc_timer_values(event
, &now
, &enabled
, &running
);
4453 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
4454 perf_output_read_group(handle
, event
, enabled
, running
);
4456 perf_output_read_one(handle
, event
, enabled
, running
);
4459 void perf_output_sample(struct perf_output_handle
*handle
,
4460 struct perf_event_header
*header
,
4461 struct perf_sample_data
*data
,
4462 struct perf_event
*event
)
4464 u64 sample_type
= data
->type
;
4466 perf_output_put(handle
, *header
);
4468 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
4469 perf_output_put(handle
, data
->id
);
4471 if (sample_type
& PERF_SAMPLE_IP
)
4472 perf_output_put(handle
, data
->ip
);
4474 if (sample_type
& PERF_SAMPLE_TID
)
4475 perf_output_put(handle
, data
->tid_entry
);
4477 if (sample_type
& PERF_SAMPLE_TIME
)
4478 perf_output_put(handle
, data
->time
);
4480 if (sample_type
& PERF_SAMPLE_ADDR
)
4481 perf_output_put(handle
, data
->addr
);
4483 if (sample_type
& PERF_SAMPLE_ID
)
4484 perf_output_put(handle
, data
->id
);
4486 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4487 perf_output_put(handle
, data
->stream_id
);
4489 if (sample_type
& PERF_SAMPLE_CPU
)
4490 perf_output_put(handle
, data
->cpu_entry
);
4492 if (sample_type
& PERF_SAMPLE_PERIOD
)
4493 perf_output_put(handle
, data
->period
);
4495 if (sample_type
& PERF_SAMPLE_READ
)
4496 perf_output_read(handle
, event
);
4498 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4499 if (data
->callchain
) {
4502 if (data
->callchain
)
4503 size
+= data
->callchain
->nr
;
4505 size
*= sizeof(u64
);
4507 __output_copy(handle
, data
->callchain
, size
);
4510 perf_output_put(handle
, nr
);
4514 if (sample_type
& PERF_SAMPLE_RAW
) {
4516 perf_output_put(handle
, data
->raw
->size
);
4517 __output_copy(handle
, data
->raw
->data
,
4524 .size
= sizeof(u32
),
4527 perf_output_put(handle
, raw
);
4531 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4532 if (data
->br_stack
) {
4535 size
= data
->br_stack
->nr
4536 * sizeof(struct perf_branch_entry
);
4538 perf_output_put(handle
, data
->br_stack
->nr
);
4539 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
4542 * we always store at least the value of nr
4545 perf_output_put(handle
, nr
);
4549 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4550 u64 abi
= data
->regs_user
.abi
;
4553 * If there are no regs to dump, notice it through
4554 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
4556 perf_output_put(handle
, abi
);
4559 u64 mask
= event
->attr
.sample_regs_user
;
4560 perf_output_sample_regs(handle
,
4561 data
->regs_user
.regs
,
4566 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
4567 perf_output_sample_ustack(handle
,
4568 data
->stack_user_size
,
4569 data
->regs_user
.regs
);
4572 if (sample_type
& PERF_SAMPLE_WEIGHT
)
4573 perf_output_put(handle
, data
->weight
);
4575 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
4576 perf_output_put(handle
, data
->data_src
.val
);
4578 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
4579 perf_output_put(handle
, data
->txn
);
4581 if (!event
->attr
.watermark
) {
4582 int wakeup_events
= event
->attr
.wakeup_events
;
4584 if (wakeup_events
) {
4585 struct ring_buffer
*rb
= handle
->rb
;
4586 int events
= local_inc_return(&rb
->events
);
4588 if (events
>= wakeup_events
) {
4589 local_sub(wakeup_events
, &rb
->events
);
4590 local_inc(&rb
->wakeup
);
4596 void perf_prepare_sample(struct perf_event_header
*header
,
4597 struct perf_sample_data
*data
,
4598 struct perf_event
*event
,
4599 struct pt_regs
*regs
)
4601 u64 sample_type
= event
->attr
.sample_type
;
4603 header
->type
= PERF_RECORD_SAMPLE
;
4604 header
->size
= sizeof(*header
) + event
->header_size
;
4607 header
->misc
|= perf_misc_flags(regs
);
4609 __perf_event_header__init_id(header
, data
, event
);
4611 if (sample_type
& PERF_SAMPLE_IP
)
4612 data
->ip
= perf_instruction_pointer(regs
);
4614 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4617 data
->callchain
= perf_callchain(event
, regs
);
4619 if (data
->callchain
)
4620 size
+= data
->callchain
->nr
;
4622 header
->size
+= size
* sizeof(u64
);
4625 if (sample_type
& PERF_SAMPLE_RAW
) {
4626 int size
= sizeof(u32
);
4629 size
+= data
->raw
->size
;
4631 size
+= sizeof(u32
);
4633 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4634 header
->size
+= size
;
4637 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4638 int size
= sizeof(u64
); /* nr */
4639 if (data
->br_stack
) {
4640 size
+= data
->br_stack
->nr
4641 * sizeof(struct perf_branch_entry
);
4643 header
->size
+= size
;
4646 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4647 /* regs dump ABI info */
4648 int size
= sizeof(u64
);
4650 perf_sample_regs_user(&data
->regs_user
, regs
);
4652 if (data
->regs_user
.regs
) {
4653 u64 mask
= event
->attr
.sample_regs_user
;
4654 size
+= hweight64(mask
) * sizeof(u64
);
4657 header
->size
+= size
;
4660 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
4662 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
4663 * processed as the last one or have additional check added
4664 * in case new sample type is added, because we could eat
4665 * up the rest of the sample size.
4667 struct perf_regs_user
*uregs
= &data
->regs_user
;
4668 u16 stack_size
= event
->attr
.sample_stack_user
;
4669 u16 size
= sizeof(u64
);
4672 perf_sample_regs_user(uregs
, regs
);
4674 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
4678 * If there is something to dump, add space for the dump
4679 * itself and for the field that tells the dynamic size,
4680 * which is how many have been actually dumped.
4683 size
+= sizeof(u64
) + stack_size
;
4685 data
->stack_user_size
= stack_size
;
4686 header
->size
+= size
;
4690 static void perf_event_output(struct perf_event
*event
,
4691 struct perf_sample_data
*data
,
4692 struct pt_regs
*regs
)
4694 struct perf_output_handle handle
;
4695 struct perf_event_header header
;
4697 /* protect the callchain buffers */
4700 perf_prepare_sample(&header
, data
, event
, regs
);
4702 if (perf_output_begin(&handle
, event
, header
.size
))
4705 perf_output_sample(&handle
, &header
, data
, event
);
4707 perf_output_end(&handle
);
4717 struct perf_read_event
{
4718 struct perf_event_header header
;
4725 perf_event_read_event(struct perf_event
*event
,
4726 struct task_struct
*task
)
4728 struct perf_output_handle handle
;
4729 struct perf_sample_data sample
;
4730 struct perf_read_event read_event
= {
4732 .type
= PERF_RECORD_READ
,
4734 .size
= sizeof(read_event
) + event
->read_size
,
4736 .pid
= perf_event_pid(event
, task
),
4737 .tid
= perf_event_tid(event
, task
),
4741 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4742 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
4746 perf_output_put(&handle
, read_event
);
4747 perf_output_read(&handle
, event
);
4748 perf_event__output_id_sample(event
, &handle
, &sample
);
4750 perf_output_end(&handle
);
4753 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
4756 perf_event_aux_ctx(struct perf_event_context
*ctx
,
4757 perf_event_aux_output_cb output
,
4760 struct perf_event
*event
;
4762 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4763 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4765 if (!event_filter_match(event
))
4767 output(event
, data
);
4772 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
4773 struct perf_event_context
*task_ctx
)
4775 struct perf_cpu_context
*cpuctx
;
4776 struct perf_event_context
*ctx
;
4781 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4782 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4783 if (cpuctx
->unique_pmu
!= pmu
)
4785 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
4788 ctxn
= pmu
->task_ctx_nr
;
4791 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4793 perf_event_aux_ctx(ctx
, output
, data
);
4795 put_cpu_ptr(pmu
->pmu_cpu_context
);
4800 perf_event_aux_ctx(task_ctx
, output
, data
);
4807 * task tracking -- fork/exit
4809 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
4812 struct perf_task_event
{
4813 struct task_struct
*task
;
4814 struct perf_event_context
*task_ctx
;
4817 struct perf_event_header header
;
4827 static int perf_event_task_match(struct perf_event
*event
)
4829 return event
->attr
.comm
|| event
->attr
.mmap
||
4830 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
4834 static void perf_event_task_output(struct perf_event
*event
,
4837 struct perf_task_event
*task_event
= data
;
4838 struct perf_output_handle handle
;
4839 struct perf_sample_data sample
;
4840 struct task_struct
*task
= task_event
->task
;
4841 int ret
, size
= task_event
->event_id
.header
.size
;
4843 if (!perf_event_task_match(event
))
4846 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4848 ret
= perf_output_begin(&handle
, event
,
4849 task_event
->event_id
.header
.size
);
4853 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4854 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4856 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4857 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4859 perf_output_put(&handle
, task_event
->event_id
);
4861 perf_event__output_id_sample(event
, &handle
, &sample
);
4863 perf_output_end(&handle
);
4865 task_event
->event_id
.header
.size
= size
;
4868 static void perf_event_task(struct task_struct
*task
,
4869 struct perf_event_context
*task_ctx
,
4872 struct perf_task_event task_event
;
4874 if (!atomic_read(&nr_comm_events
) &&
4875 !atomic_read(&nr_mmap_events
) &&
4876 !atomic_read(&nr_task_events
))
4879 task_event
= (struct perf_task_event
){
4881 .task_ctx
= task_ctx
,
4884 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4886 .size
= sizeof(task_event
.event_id
),
4892 .time
= perf_clock(),
4896 perf_event_aux(perf_event_task_output
,
4901 void perf_event_fork(struct task_struct
*task
)
4903 perf_event_task(task
, NULL
, 1);
4910 struct perf_comm_event
{
4911 struct task_struct
*task
;
4916 struct perf_event_header header
;
4923 static int perf_event_comm_match(struct perf_event
*event
)
4925 return event
->attr
.comm
;
4928 static void perf_event_comm_output(struct perf_event
*event
,
4931 struct perf_comm_event
*comm_event
= data
;
4932 struct perf_output_handle handle
;
4933 struct perf_sample_data sample
;
4934 int size
= comm_event
->event_id
.header
.size
;
4937 if (!perf_event_comm_match(event
))
4940 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4941 ret
= perf_output_begin(&handle
, event
,
4942 comm_event
->event_id
.header
.size
);
4947 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4948 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4950 perf_output_put(&handle
, comm_event
->event_id
);
4951 __output_copy(&handle
, comm_event
->comm
,
4952 comm_event
->comm_size
);
4954 perf_event__output_id_sample(event
, &handle
, &sample
);
4956 perf_output_end(&handle
);
4958 comm_event
->event_id
.header
.size
= size
;
4961 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4963 char comm
[TASK_COMM_LEN
];
4966 memset(comm
, 0, sizeof(comm
));
4967 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4968 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4970 comm_event
->comm
= comm
;
4971 comm_event
->comm_size
= size
;
4973 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4975 perf_event_aux(perf_event_comm_output
,
4980 void perf_event_comm(struct task_struct
*task
)
4982 struct perf_comm_event comm_event
;
4983 struct perf_event_context
*ctx
;
4987 for_each_task_context_nr(ctxn
) {
4988 ctx
= task
->perf_event_ctxp
[ctxn
];
4992 perf_event_enable_on_exec(ctx
);
4996 if (!atomic_read(&nr_comm_events
))
4999 comm_event
= (struct perf_comm_event
){
5005 .type
= PERF_RECORD_COMM
,
5014 perf_event_comm_event(&comm_event
);
5021 struct perf_mmap_event
{
5022 struct vm_area_struct
*vma
;
5024 const char *file_name
;
5031 struct perf_event_header header
;
5041 static int perf_event_mmap_match(struct perf_event
*event
,
5044 struct perf_mmap_event
*mmap_event
= data
;
5045 struct vm_area_struct
*vma
= mmap_event
->vma
;
5046 int executable
= vma
->vm_flags
& VM_EXEC
;
5048 return (!executable
&& event
->attr
.mmap_data
) ||
5049 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5052 static void perf_event_mmap_output(struct perf_event
*event
,
5055 struct perf_mmap_event
*mmap_event
= data
;
5056 struct perf_output_handle handle
;
5057 struct perf_sample_data sample
;
5058 int size
= mmap_event
->event_id
.header
.size
;
5061 if (!perf_event_mmap_match(event
, data
))
5064 if (event
->attr
.mmap2
) {
5065 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5066 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5067 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5068 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5069 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5072 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5073 ret
= perf_output_begin(&handle
, event
,
5074 mmap_event
->event_id
.header
.size
);
5078 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5079 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5081 perf_output_put(&handle
, mmap_event
->event_id
);
5083 if (event
->attr
.mmap2
) {
5084 perf_output_put(&handle
, mmap_event
->maj
);
5085 perf_output_put(&handle
, mmap_event
->min
);
5086 perf_output_put(&handle
, mmap_event
->ino
);
5087 perf_output_put(&handle
, mmap_event
->ino_generation
);
5090 __output_copy(&handle
, mmap_event
->file_name
,
5091 mmap_event
->file_size
);
5093 perf_event__output_id_sample(event
, &handle
, &sample
);
5095 perf_output_end(&handle
);
5097 mmap_event
->event_id
.header
.size
= size
;
5100 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5102 struct vm_area_struct
*vma
= mmap_event
->vma
;
5103 struct file
*file
= vma
->vm_file
;
5104 int maj
= 0, min
= 0;
5105 u64 ino
= 0, gen
= 0;
5111 memset(tmp
, 0, sizeof(tmp
));
5114 struct inode
*inode
;
5117 * d_path works from the end of the rb backwards, so we
5118 * need to add enough zero bytes after the string to handle
5119 * the 64bit alignment we do later.
5121 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
5123 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
5126 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
5128 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
5131 inode
= file_inode(vma
->vm_file
);
5132 dev
= inode
->i_sb
->s_dev
;
5134 gen
= inode
->i_generation
;
5139 name
= arch_vma_name(vma
);
5141 name
= strncpy(tmp
, name
, sizeof(tmp
) - 1);
5142 tmp
[sizeof(tmp
) - 1] = '\0';
5146 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
5147 vma
->vm_end
>= vma
->vm_mm
->brk
) {
5148 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
5151 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
5152 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
5153 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
5157 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
5162 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
5164 mmap_event
->file_name
= name
;
5165 mmap_event
->file_size
= size
;
5166 mmap_event
->maj
= maj
;
5167 mmap_event
->min
= min
;
5168 mmap_event
->ino
= ino
;
5169 mmap_event
->ino_generation
= gen
;
5171 if (!(vma
->vm_flags
& VM_EXEC
))
5172 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
5174 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
5176 perf_event_aux(perf_event_mmap_output
,
5183 void perf_event_mmap(struct vm_area_struct
*vma
)
5185 struct perf_mmap_event mmap_event
;
5187 if (!atomic_read(&nr_mmap_events
))
5190 mmap_event
= (struct perf_mmap_event
){
5196 .type
= PERF_RECORD_MMAP
,
5197 .misc
= PERF_RECORD_MISC_USER
,
5202 .start
= vma
->vm_start
,
5203 .len
= vma
->vm_end
- vma
->vm_start
,
5204 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
5206 /* .maj (attr_mmap2 only) */
5207 /* .min (attr_mmap2 only) */
5208 /* .ino (attr_mmap2 only) */
5209 /* .ino_generation (attr_mmap2 only) */
5212 perf_event_mmap_event(&mmap_event
);
5216 * IRQ throttle logging
5219 static void perf_log_throttle(struct perf_event
*event
, int enable
)
5221 struct perf_output_handle handle
;
5222 struct perf_sample_data sample
;
5226 struct perf_event_header header
;
5230 } throttle_event
= {
5232 .type
= PERF_RECORD_THROTTLE
,
5234 .size
= sizeof(throttle_event
),
5236 .time
= perf_clock(),
5237 .id
= primary_event_id(event
),
5238 .stream_id
= event
->id
,
5242 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
5244 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
5246 ret
= perf_output_begin(&handle
, event
,
5247 throttle_event
.header
.size
);
5251 perf_output_put(&handle
, throttle_event
);
5252 perf_event__output_id_sample(event
, &handle
, &sample
);
5253 perf_output_end(&handle
);
5257 * Generic event overflow handling, sampling.
5260 static int __perf_event_overflow(struct perf_event
*event
,
5261 int throttle
, struct perf_sample_data
*data
,
5262 struct pt_regs
*regs
)
5264 int events
= atomic_read(&event
->event_limit
);
5265 struct hw_perf_event
*hwc
= &event
->hw
;
5270 * Non-sampling counters might still use the PMI to fold short
5271 * hardware counters, ignore those.
5273 if (unlikely(!is_sampling_event(event
)))
5276 seq
= __this_cpu_read(perf_throttled_seq
);
5277 if (seq
!= hwc
->interrupts_seq
) {
5278 hwc
->interrupts_seq
= seq
;
5279 hwc
->interrupts
= 1;
5282 if (unlikely(throttle
5283 && hwc
->interrupts
>= max_samples_per_tick
)) {
5284 __this_cpu_inc(perf_throttled_count
);
5285 hwc
->interrupts
= MAX_INTERRUPTS
;
5286 perf_log_throttle(event
, 0);
5287 tick_nohz_full_kick();
5292 if (event
->attr
.freq
) {
5293 u64 now
= perf_clock();
5294 s64 delta
= now
- hwc
->freq_time_stamp
;
5296 hwc
->freq_time_stamp
= now
;
5298 if (delta
> 0 && delta
< 2*TICK_NSEC
)
5299 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
5303 * XXX event_limit might not quite work as expected on inherited
5307 event
->pending_kill
= POLL_IN
;
5308 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
5310 event
->pending_kill
= POLL_HUP
;
5311 event
->pending_disable
= 1;
5312 irq_work_queue(&event
->pending
);
5315 if (event
->overflow_handler
)
5316 event
->overflow_handler(event
, data
, regs
);
5318 perf_event_output(event
, data
, regs
);
5320 if (event
->fasync
&& event
->pending_kill
) {
5321 event
->pending_wakeup
= 1;
5322 irq_work_queue(&event
->pending
);
5328 int perf_event_overflow(struct perf_event
*event
,
5329 struct perf_sample_data
*data
,
5330 struct pt_regs
*regs
)
5332 return __perf_event_overflow(event
, 1, data
, regs
);
5336 * Generic software event infrastructure
5339 struct swevent_htable
{
5340 struct swevent_hlist
*swevent_hlist
;
5341 struct mutex hlist_mutex
;
5344 /* Recursion avoidance in each contexts */
5345 int recursion
[PERF_NR_CONTEXTS
];
5348 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
5351 * We directly increment event->count and keep a second value in
5352 * event->hw.period_left to count intervals. This period event
5353 * is kept in the range [-sample_period, 0] so that we can use the
5357 u64
perf_swevent_set_period(struct perf_event
*event
)
5359 struct hw_perf_event
*hwc
= &event
->hw
;
5360 u64 period
= hwc
->last_period
;
5364 hwc
->last_period
= hwc
->sample_period
;
5367 old
= val
= local64_read(&hwc
->period_left
);
5371 nr
= div64_u64(period
+ val
, period
);
5372 offset
= nr
* period
;
5374 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
5380 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
5381 struct perf_sample_data
*data
,
5382 struct pt_regs
*regs
)
5384 struct hw_perf_event
*hwc
= &event
->hw
;
5388 overflow
= perf_swevent_set_period(event
);
5390 if (hwc
->interrupts
== MAX_INTERRUPTS
)
5393 for (; overflow
; overflow
--) {
5394 if (__perf_event_overflow(event
, throttle
,
5397 * We inhibit the overflow from happening when
5398 * hwc->interrupts == MAX_INTERRUPTS.
5406 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
5407 struct perf_sample_data
*data
,
5408 struct pt_regs
*regs
)
5410 struct hw_perf_event
*hwc
= &event
->hw
;
5412 local64_add(nr
, &event
->count
);
5417 if (!is_sampling_event(event
))
5420 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
5422 return perf_swevent_overflow(event
, 1, data
, regs
);
5424 data
->period
= event
->hw
.last_period
;
5426 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
5427 return perf_swevent_overflow(event
, 1, data
, regs
);
5429 if (local64_add_negative(nr
, &hwc
->period_left
))
5432 perf_swevent_overflow(event
, 0, data
, regs
);
5435 static int perf_exclude_event(struct perf_event
*event
,
5436 struct pt_regs
*regs
)
5438 if (event
->hw
.state
& PERF_HES_STOPPED
)
5442 if (event
->attr
.exclude_user
&& user_mode(regs
))
5445 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
5452 static int perf_swevent_match(struct perf_event
*event
,
5453 enum perf_type_id type
,
5455 struct perf_sample_data
*data
,
5456 struct pt_regs
*regs
)
5458 if (event
->attr
.type
!= type
)
5461 if (event
->attr
.config
!= event_id
)
5464 if (perf_exclude_event(event
, regs
))
5470 static inline u64
swevent_hash(u64 type
, u32 event_id
)
5472 u64 val
= event_id
| (type
<< 32);
5474 return hash_64(val
, SWEVENT_HLIST_BITS
);
5477 static inline struct hlist_head
*
5478 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
5480 u64 hash
= swevent_hash(type
, event_id
);
5482 return &hlist
->heads
[hash
];
5485 /* For the read side: events when they trigger */
5486 static inline struct hlist_head
*
5487 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
5489 struct swevent_hlist
*hlist
;
5491 hlist
= rcu_dereference(swhash
->swevent_hlist
);
5495 return __find_swevent_head(hlist
, type
, event_id
);
5498 /* For the event head insertion and removal in the hlist */
5499 static inline struct hlist_head
*
5500 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
5502 struct swevent_hlist
*hlist
;
5503 u32 event_id
= event
->attr
.config
;
5504 u64 type
= event
->attr
.type
;
5507 * Event scheduling is always serialized against hlist allocation
5508 * and release. Which makes the protected version suitable here.
5509 * The context lock guarantees that.
5511 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
5512 lockdep_is_held(&event
->ctx
->lock
));
5516 return __find_swevent_head(hlist
, type
, event_id
);
5519 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
5521 struct perf_sample_data
*data
,
5522 struct pt_regs
*regs
)
5524 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5525 struct perf_event
*event
;
5526 struct hlist_head
*head
;
5529 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
5533 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5534 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
5535 perf_swevent_event(event
, nr
, data
, regs
);
5541 int perf_swevent_get_recursion_context(void)
5543 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5545 return get_recursion_context(swhash
->recursion
);
5547 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
5549 inline void perf_swevent_put_recursion_context(int rctx
)
5551 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5553 put_recursion_context(swhash
->recursion
, rctx
);
5556 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
5558 struct perf_sample_data data
;
5561 preempt_disable_notrace();
5562 rctx
= perf_swevent_get_recursion_context();
5566 perf_sample_data_init(&data
, addr
, 0);
5568 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
5570 perf_swevent_put_recursion_context(rctx
);
5571 preempt_enable_notrace();
5574 static void perf_swevent_read(struct perf_event
*event
)
5578 static int perf_swevent_add(struct perf_event
*event
, int flags
)
5580 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5581 struct hw_perf_event
*hwc
= &event
->hw
;
5582 struct hlist_head
*head
;
5584 if (is_sampling_event(event
)) {
5585 hwc
->last_period
= hwc
->sample_period
;
5586 perf_swevent_set_period(event
);
5589 hwc
->state
= !(flags
& PERF_EF_START
);
5591 head
= find_swevent_head(swhash
, event
);
5592 if (WARN_ON_ONCE(!head
))
5595 hlist_add_head_rcu(&event
->hlist_entry
, head
);
5600 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5602 hlist_del_rcu(&event
->hlist_entry
);
5605 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5607 event
->hw
.state
= 0;
5610 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5612 event
->hw
.state
= PERF_HES_STOPPED
;
5615 /* Deref the hlist from the update side */
5616 static inline struct swevent_hlist
*
5617 swevent_hlist_deref(struct swevent_htable
*swhash
)
5619 return rcu_dereference_protected(swhash
->swevent_hlist
,
5620 lockdep_is_held(&swhash
->hlist_mutex
));
5623 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5625 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5630 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5631 kfree_rcu(hlist
, rcu_head
);
5634 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5636 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5638 mutex_lock(&swhash
->hlist_mutex
);
5640 if (!--swhash
->hlist_refcount
)
5641 swevent_hlist_release(swhash
);
5643 mutex_unlock(&swhash
->hlist_mutex
);
5646 static void swevent_hlist_put(struct perf_event
*event
)
5650 if (event
->cpu
!= -1) {
5651 swevent_hlist_put_cpu(event
, event
->cpu
);
5655 for_each_possible_cpu(cpu
)
5656 swevent_hlist_put_cpu(event
, cpu
);
5659 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5661 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5664 mutex_lock(&swhash
->hlist_mutex
);
5666 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5667 struct swevent_hlist
*hlist
;
5669 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5674 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5676 swhash
->hlist_refcount
++;
5678 mutex_unlock(&swhash
->hlist_mutex
);
5683 static int swevent_hlist_get(struct perf_event
*event
)
5686 int cpu
, failed_cpu
;
5688 if (event
->cpu
!= -1)
5689 return swevent_hlist_get_cpu(event
, event
->cpu
);
5692 for_each_possible_cpu(cpu
) {
5693 err
= swevent_hlist_get_cpu(event
, cpu
);
5703 for_each_possible_cpu(cpu
) {
5704 if (cpu
== failed_cpu
)
5706 swevent_hlist_put_cpu(event
, cpu
);
5713 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5715 static void sw_perf_event_destroy(struct perf_event
*event
)
5717 u64 event_id
= event
->attr
.config
;
5719 WARN_ON(event
->parent
);
5721 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
5722 swevent_hlist_put(event
);
5725 static int perf_swevent_init(struct perf_event
*event
)
5727 u64 event_id
= event
->attr
.config
;
5729 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5733 * no branch sampling for software events
5735 if (has_branch_stack(event
))
5739 case PERF_COUNT_SW_CPU_CLOCK
:
5740 case PERF_COUNT_SW_TASK_CLOCK
:
5747 if (event_id
>= PERF_COUNT_SW_MAX
)
5750 if (!event
->parent
) {
5753 err
= swevent_hlist_get(event
);
5757 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
5758 event
->destroy
= sw_perf_event_destroy
;
5764 static int perf_swevent_event_idx(struct perf_event
*event
)
5769 static struct pmu perf_swevent
= {
5770 .task_ctx_nr
= perf_sw_context
,
5772 .event_init
= perf_swevent_init
,
5773 .add
= perf_swevent_add
,
5774 .del
= perf_swevent_del
,
5775 .start
= perf_swevent_start
,
5776 .stop
= perf_swevent_stop
,
5777 .read
= perf_swevent_read
,
5779 .event_idx
= perf_swevent_event_idx
,
5782 #ifdef CONFIG_EVENT_TRACING
5784 static int perf_tp_filter_match(struct perf_event
*event
,
5785 struct perf_sample_data
*data
)
5787 void *record
= data
->raw
->data
;
5789 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5794 static int perf_tp_event_match(struct perf_event
*event
,
5795 struct perf_sample_data
*data
,
5796 struct pt_regs
*regs
)
5798 if (event
->hw
.state
& PERF_HES_STOPPED
)
5801 * All tracepoints are from kernel-space.
5803 if (event
->attr
.exclude_kernel
)
5806 if (!perf_tp_filter_match(event
, data
))
5812 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5813 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
5814 struct task_struct
*task
)
5816 struct perf_sample_data data
;
5817 struct perf_event
*event
;
5819 struct perf_raw_record raw
= {
5824 perf_sample_data_init(&data
, addr
, 0);
5827 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5828 if (perf_tp_event_match(event
, &data
, regs
))
5829 perf_swevent_event(event
, count
, &data
, regs
);
5833 * If we got specified a target task, also iterate its context and
5834 * deliver this event there too.
5836 if (task
&& task
!= current
) {
5837 struct perf_event_context
*ctx
;
5838 struct trace_entry
*entry
= record
;
5841 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
5845 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5846 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5848 if (event
->attr
.config
!= entry
->type
)
5850 if (perf_tp_event_match(event
, &data
, regs
))
5851 perf_swevent_event(event
, count
, &data
, regs
);
5857 perf_swevent_put_recursion_context(rctx
);
5859 EXPORT_SYMBOL_GPL(perf_tp_event
);
5861 static void tp_perf_event_destroy(struct perf_event
*event
)
5863 perf_trace_destroy(event
);
5866 static int perf_tp_event_init(struct perf_event
*event
)
5870 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5874 * no branch sampling for tracepoint events
5876 if (has_branch_stack(event
))
5879 err
= perf_trace_init(event
);
5883 event
->destroy
= tp_perf_event_destroy
;
5888 static struct pmu perf_tracepoint
= {
5889 .task_ctx_nr
= perf_sw_context
,
5891 .event_init
= perf_tp_event_init
,
5892 .add
= perf_trace_add
,
5893 .del
= perf_trace_del
,
5894 .start
= perf_swevent_start
,
5895 .stop
= perf_swevent_stop
,
5896 .read
= perf_swevent_read
,
5898 .event_idx
= perf_swevent_event_idx
,
5901 static inline void perf_tp_register(void)
5903 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5906 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5911 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5914 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5915 if (IS_ERR(filter_str
))
5916 return PTR_ERR(filter_str
);
5918 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5924 static void perf_event_free_filter(struct perf_event
*event
)
5926 ftrace_profile_free_filter(event
);
5931 static inline void perf_tp_register(void)
5935 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5940 static void perf_event_free_filter(struct perf_event
*event
)
5944 #endif /* CONFIG_EVENT_TRACING */
5946 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5947 void perf_bp_event(struct perf_event
*bp
, void *data
)
5949 struct perf_sample_data sample
;
5950 struct pt_regs
*regs
= data
;
5952 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
5954 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5955 perf_swevent_event(bp
, 1, &sample
, regs
);
5960 * hrtimer based swevent callback
5963 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5965 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5966 struct perf_sample_data data
;
5967 struct pt_regs
*regs
;
5968 struct perf_event
*event
;
5971 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5973 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5974 return HRTIMER_NORESTART
;
5976 event
->pmu
->read(event
);
5978 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
5979 regs
= get_irq_regs();
5981 if (regs
&& !perf_exclude_event(event
, regs
)) {
5982 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
5983 if (__perf_event_overflow(event
, 1, &data
, regs
))
5984 ret
= HRTIMER_NORESTART
;
5987 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5988 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5993 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5995 struct hw_perf_event
*hwc
= &event
->hw
;
5998 if (!is_sampling_event(event
))
6001 period
= local64_read(&hwc
->period_left
);
6006 local64_set(&hwc
->period_left
, 0);
6008 period
= max_t(u64
, 10000, hwc
->sample_period
);
6010 __hrtimer_start_range_ns(&hwc
->hrtimer
,
6011 ns_to_ktime(period
), 0,
6012 HRTIMER_MODE_REL_PINNED
, 0);
6015 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
6017 struct hw_perf_event
*hwc
= &event
->hw
;
6019 if (is_sampling_event(event
)) {
6020 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
6021 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
6023 hrtimer_cancel(&hwc
->hrtimer
);
6027 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
6029 struct hw_perf_event
*hwc
= &event
->hw
;
6031 if (!is_sampling_event(event
))
6034 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
6035 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
6038 * Since hrtimers have a fixed rate, we can do a static freq->period
6039 * mapping and avoid the whole period adjust feedback stuff.
6041 if (event
->attr
.freq
) {
6042 long freq
= event
->attr
.sample_freq
;
6044 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
6045 hwc
->sample_period
= event
->attr
.sample_period
;
6046 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6047 hwc
->last_period
= hwc
->sample_period
;
6048 event
->attr
.freq
= 0;
6053 * Software event: cpu wall time clock
6056 static void cpu_clock_event_update(struct perf_event
*event
)
6061 now
= local_clock();
6062 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
6063 local64_add(now
- prev
, &event
->count
);
6066 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
6068 local64_set(&event
->hw
.prev_count
, local_clock());
6069 perf_swevent_start_hrtimer(event
);
6072 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
6074 perf_swevent_cancel_hrtimer(event
);
6075 cpu_clock_event_update(event
);
6078 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
6080 if (flags
& PERF_EF_START
)
6081 cpu_clock_event_start(event
, flags
);
6086 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
6088 cpu_clock_event_stop(event
, flags
);
6091 static void cpu_clock_event_read(struct perf_event
*event
)
6093 cpu_clock_event_update(event
);
6096 static int cpu_clock_event_init(struct perf_event
*event
)
6098 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6101 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
6105 * no branch sampling for software events
6107 if (has_branch_stack(event
))
6110 perf_swevent_init_hrtimer(event
);
6115 static struct pmu perf_cpu_clock
= {
6116 .task_ctx_nr
= perf_sw_context
,
6118 .event_init
= cpu_clock_event_init
,
6119 .add
= cpu_clock_event_add
,
6120 .del
= cpu_clock_event_del
,
6121 .start
= cpu_clock_event_start
,
6122 .stop
= cpu_clock_event_stop
,
6123 .read
= cpu_clock_event_read
,
6125 .event_idx
= perf_swevent_event_idx
,
6129 * Software event: task time clock
6132 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
6137 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
6139 local64_add(delta
, &event
->count
);
6142 static void task_clock_event_start(struct perf_event
*event
, int flags
)
6144 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
6145 perf_swevent_start_hrtimer(event
);
6148 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
6150 perf_swevent_cancel_hrtimer(event
);
6151 task_clock_event_update(event
, event
->ctx
->time
);
6154 static int task_clock_event_add(struct perf_event
*event
, int flags
)
6156 if (flags
& PERF_EF_START
)
6157 task_clock_event_start(event
, flags
);
6162 static void task_clock_event_del(struct perf_event
*event
, int flags
)
6164 task_clock_event_stop(event
, PERF_EF_UPDATE
);
6167 static void task_clock_event_read(struct perf_event
*event
)
6169 u64 now
= perf_clock();
6170 u64 delta
= now
- event
->ctx
->timestamp
;
6171 u64 time
= event
->ctx
->time
+ delta
;
6173 task_clock_event_update(event
, time
);
6176 static int task_clock_event_init(struct perf_event
*event
)
6178 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6181 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
6185 * no branch sampling for software events
6187 if (has_branch_stack(event
))
6190 perf_swevent_init_hrtimer(event
);
6195 static struct pmu perf_task_clock
= {
6196 .task_ctx_nr
= perf_sw_context
,
6198 .event_init
= task_clock_event_init
,
6199 .add
= task_clock_event_add
,
6200 .del
= task_clock_event_del
,
6201 .start
= task_clock_event_start
,
6202 .stop
= task_clock_event_stop
,
6203 .read
= task_clock_event_read
,
6205 .event_idx
= perf_swevent_event_idx
,
6208 static void perf_pmu_nop_void(struct pmu
*pmu
)
6212 static int perf_pmu_nop_int(struct pmu
*pmu
)
6217 static void perf_pmu_start_txn(struct pmu
*pmu
)
6219 perf_pmu_disable(pmu
);
6222 static int perf_pmu_commit_txn(struct pmu
*pmu
)
6224 perf_pmu_enable(pmu
);
6228 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
6230 perf_pmu_enable(pmu
);
6233 static int perf_event_idx_default(struct perf_event
*event
)
6235 return event
->hw
.idx
+ 1;
6239 * Ensures all contexts with the same task_ctx_nr have the same
6240 * pmu_cpu_context too.
6242 static void *find_pmu_context(int ctxn
)
6249 list_for_each_entry(pmu
, &pmus
, entry
) {
6250 if (pmu
->task_ctx_nr
== ctxn
)
6251 return pmu
->pmu_cpu_context
;
6257 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
6261 for_each_possible_cpu(cpu
) {
6262 struct perf_cpu_context
*cpuctx
;
6264 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6266 if (cpuctx
->unique_pmu
== old_pmu
)
6267 cpuctx
->unique_pmu
= pmu
;
6271 static void free_pmu_context(struct pmu
*pmu
)
6275 mutex_lock(&pmus_lock
);
6277 * Like a real lame refcount.
6279 list_for_each_entry(i
, &pmus
, entry
) {
6280 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
6281 update_pmu_context(i
, pmu
);
6286 free_percpu(pmu
->pmu_cpu_context
);
6288 mutex_unlock(&pmus_lock
);
6290 static struct idr pmu_idr
;
6293 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
6295 struct pmu
*pmu
= dev_get_drvdata(dev
);
6297 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
6301 perf_event_mux_interval_ms_show(struct device
*dev
,
6302 struct device_attribute
*attr
,
6305 struct pmu
*pmu
= dev_get_drvdata(dev
);
6307 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
6311 perf_event_mux_interval_ms_store(struct device
*dev
,
6312 struct device_attribute
*attr
,
6313 const char *buf
, size_t count
)
6315 struct pmu
*pmu
= dev_get_drvdata(dev
);
6316 int timer
, cpu
, ret
;
6318 ret
= kstrtoint(buf
, 0, &timer
);
6325 /* same value, noting to do */
6326 if (timer
== pmu
->hrtimer_interval_ms
)
6329 pmu
->hrtimer_interval_ms
= timer
;
6331 /* update all cpuctx for this PMU */
6332 for_each_possible_cpu(cpu
) {
6333 struct perf_cpu_context
*cpuctx
;
6334 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6335 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
6337 if (hrtimer_active(&cpuctx
->hrtimer
))
6338 hrtimer_forward_now(&cpuctx
->hrtimer
, cpuctx
->hrtimer_interval
);
6344 static struct device_attribute pmu_dev_attrs
[] = {
6346 __ATTR_RW(perf_event_mux_interval_ms
),
6350 static int pmu_bus_running
;
6351 static struct bus_type pmu_bus
= {
6352 .name
= "event_source",
6353 .dev_attrs
= pmu_dev_attrs
,
6356 static void pmu_dev_release(struct device
*dev
)
6361 static int pmu_dev_alloc(struct pmu
*pmu
)
6365 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
6369 pmu
->dev
->groups
= pmu
->attr_groups
;
6370 device_initialize(pmu
->dev
);
6371 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
6375 dev_set_drvdata(pmu
->dev
, pmu
);
6376 pmu
->dev
->bus
= &pmu_bus
;
6377 pmu
->dev
->release
= pmu_dev_release
;
6378 ret
= device_add(pmu
->dev
);
6386 put_device(pmu
->dev
);
6390 static struct lock_class_key cpuctx_mutex
;
6391 static struct lock_class_key cpuctx_lock
;
6393 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
6397 mutex_lock(&pmus_lock
);
6399 pmu
->pmu_disable_count
= alloc_percpu(int);
6400 if (!pmu
->pmu_disable_count
)
6409 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
6417 if (pmu_bus_running
) {
6418 ret
= pmu_dev_alloc(pmu
);
6424 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
6425 if (pmu
->pmu_cpu_context
)
6426 goto got_cpu_context
;
6429 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
6430 if (!pmu
->pmu_cpu_context
)
6433 for_each_possible_cpu(cpu
) {
6434 struct perf_cpu_context
*cpuctx
;
6436 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6437 __perf_event_init_context(&cpuctx
->ctx
);
6438 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
6439 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
6440 cpuctx
->ctx
.type
= cpu_context
;
6441 cpuctx
->ctx
.pmu
= pmu
;
6443 __perf_cpu_hrtimer_init(cpuctx
, cpu
);
6445 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
6446 cpuctx
->unique_pmu
= pmu
;
6450 if (!pmu
->start_txn
) {
6451 if (pmu
->pmu_enable
) {
6453 * If we have pmu_enable/pmu_disable calls, install
6454 * transaction stubs that use that to try and batch
6455 * hardware accesses.
6457 pmu
->start_txn
= perf_pmu_start_txn
;
6458 pmu
->commit_txn
= perf_pmu_commit_txn
;
6459 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
6461 pmu
->start_txn
= perf_pmu_nop_void
;
6462 pmu
->commit_txn
= perf_pmu_nop_int
;
6463 pmu
->cancel_txn
= perf_pmu_nop_void
;
6467 if (!pmu
->pmu_enable
) {
6468 pmu
->pmu_enable
= perf_pmu_nop_void
;
6469 pmu
->pmu_disable
= perf_pmu_nop_void
;
6472 if (!pmu
->event_idx
)
6473 pmu
->event_idx
= perf_event_idx_default
;
6475 list_add_rcu(&pmu
->entry
, &pmus
);
6478 mutex_unlock(&pmus_lock
);
6483 device_del(pmu
->dev
);
6484 put_device(pmu
->dev
);
6487 if (pmu
->type
>= PERF_TYPE_MAX
)
6488 idr_remove(&pmu_idr
, pmu
->type
);
6491 free_percpu(pmu
->pmu_disable_count
);
6495 void perf_pmu_unregister(struct pmu
*pmu
)
6497 mutex_lock(&pmus_lock
);
6498 list_del_rcu(&pmu
->entry
);
6499 mutex_unlock(&pmus_lock
);
6502 * We dereference the pmu list under both SRCU and regular RCU, so
6503 * synchronize against both of those.
6505 synchronize_srcu(&pmus_srcu
);
6508 free_percpu(pmu
->pmu_disable_count
);
6509 if (pmu
->type
>= PERF_TYPE_MAX
)
6510 idr_remove(&pmu_idr
, pmu
->type
);
6511 device_del(pmu
->dev
);
6512 put_device(pmu
->dev
);
6513 free_pmu_context(pmu
);
6516 struct pmu
*perf_init_event(struct perf_event
*event
)
6518 struct pmu
*pmu
= NULL
;
6522 idx
= srcu_read_lock(&pmus_srcu
);
6525 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
6529 ret
= pmu
->event_init(event
);
6535 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6537 ret
= pmu
->event_init(event
);
6541 if (ret
!= -ENOENT
) {
6546 pmu
= ERR_PTR(-ENOENT
);
6548 srcu_read_unlock(&pmus_srcu
, idx
);
6553 static void account_event_cpu(struct perf_event
*event
, int cpu
)
6558 if (has_branch_stack(event
)) {
6559 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
6560 atomic_inc(&per_cpu(perf_branch_stack_events
, cpu
));
6562 if (is_cgroup_event(event
))
6563 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
6566 static void account_event(struct perf_event
*event
)
6571 if (event
->attach_state
& PERF_ATTACH_TASK
)
6572 static_key_slow_inc(&perf_sched_events
.key
);
6573 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
6574 atomic_inc(&nr_mmap_events
);
6575 if (event
->attr
.comm
)
6576 atomic_inc(&nr_comm_events
);
6577 if (event
->attr
.task
)
6578 atomic_inc(&nr_task_events
);
6579 if (event
->attr
.freq
) {
6580 if (atomic_inc_return(&nr_freq_events
) == 1)
6581 tick_nohz_full_kick_all();
6583 if (has_branch_stack(event
))
6584 static_key_slow_inc(&perf_sched_events
.key
);
6585 if (is_cgroup_event(event
))
6586 static_key_slow_inc(&perf_sched_events
.key
);
6588 account_event_cpu(event
, event
->cpu
);
6592 * Allocate and initialize a event structure
6594 static struct perf_event
*
6595 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
6596 struct task_struct
*task
,
6597 struct perf_event
*group_leader
,
6598 struct perf_event
*parent_event
,
6599 perf_overflow_handler_t overflow_handler
,
6603 struct perf_event
*event
;
6604 struct hw_perf_event
*hwc
;
6607 if ((unsigned)cpu
>= nr_cpu_ids
) {
6608 if (!task
|| cpu
!= -1)
6609 return ERR_PTR(-EINVAL
);
6612 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
6614 return ERR_PTR(-ENOMEM
);
6617 * Single events are their own group leaders, with an
6618 * empty sibling list:
6621 group_leader
= event
;
6623 mutex_init(&event
->child_mutex
);
6624 INIT_LIST_HEAD(&event
->child_list
);
6626 INIT_LIST_HEAD(&event
->group_entry
);
6627 INIT_LIST_HEAD(&event
->event_entry
);
6628 INIT_LIST_HEAD(&event
->sibling_list
);
6629 INIT_LIST_HEAD(&event
->rb_entry
);
6631 init_waitqueue_head(&event
->waitq
);
6632 init_irq_work(&event
->pending
, perf_pending_event
);
6634 mutex_init(&event
->mmap_mutex
);
6636 atomic_long_set(&event
->refcount
, 1);
6638 event
->attr
= *attr
;
6639 event
->group_leader
= group_leader
;
6643 event
->parent
= parent_event
;
6645 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
6646 event
->id
= atomic64_inc_return(&perf_event_id
);
6648 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6651 event
->attach_state
= PERF_ATTACH_TASK
;
6653 if (attr
->type
== PERF_TYPE_TRACEPOINT
)
6654 event
->hw
.tp_target
= task
;
6655 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6657 * hw_breakpoint is a bit difficult here..
6659 else if (attr
->type
== PERF_TYPE_BREAKPOINT
)
6660 event
->hw
.bp_target
= task
;
6664 if (!overflow_handler
&& parent_event
) {
6665 overflow_handler
= parent_event
->overflow_handler
;
6666 context
= parent_event
->overflow_handler_context
;
6669 event
->overflow_handler
= overflow_handler
;
6670 event
->overflow_handler_context
= context
;
6672 perf_event__state_init(event
);
6677 hwc
->sample_period
= attr
->sample_period
;
6678 if (attr
->freq
&& attr
->sample_freq
)
6679 hwc
->sample_period
= 1;
6680 hwc
->last_period
= hwc
->sample_period
;
6682 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6685 * we currently do not support PERF_FORMAT_GROUP on inherited events
6687 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
6690 pmu
= perf_init_event(event
);
6693 else if (IS_ERR(pmu
)) {
6698 if (!event
->parent
) {
6699 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6700 err
= get_callchain_buffers();
6710 event
->destroy(event
);
6713 put_pid_ns(event
->ns
);
6716 return ERR_PTR(err
);
6719 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6720 struct perf_event_attr
*attr
)
6725 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6729 * zero the full structure, so that a short copy will be nice.
6731 memset(attr
, 0, sizeof(*attr
));
6733 ret
= get_user(size
, &uattr
->size
);
6737 if (size
> PAGE_SIZE
) /* silly large */
6740 if (!size
) /* abi compat */
6741 size
= PERF_ATTR_SIZE_VER0
;
6743 if (size
< PERF_ATTR_SIZE_VER0
)
6747 * If we're handed a bigger struct than we know of,
6748 * ensure all the unknown bits are 0 - i.e. new
6749 * user-space does not rely on any kernel feature
6750 * extensions we dont know about yet.
6752 if (size
> sizeof(*attr
)) {
6753 unsigned char __user
*addr
;
6754 unsigned char __user
*end
;
6757 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6758 end
= (void __user
*)uattr
+ size
;
6760 for (; addr
< end
; addr
++) {
6761 ret
= get_user(val
, addr
);
6767 size
= sizeof(*attr
);
6770 ret
= copy_from_user(attr
, uattr
, size
);
6774 /* disabled for now */
6778 if (attr
->__reserved_1
)
6781 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6784 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6787 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6788 u64 mask
= attr
->branch_sample_type
;
6790 /* only using defined bits */
6791 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
6794 /* at least one branch bit must be set */
6795 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
6798 /* propagate priv level, when not set for branch */
6799 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
6801 /* exclude_kernel checked on syscall entry */
6802 if (!attr
->exclude_kernel
)
6803 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
6805 if (!attr
->exclude_user
)
6806 mask
|= PERF_SAMPLE_BRANCH_USER
;
6808 if (!attr
->exclude_hv
)
6809 mask
|= PERF_SAMPLE_BRANCH_HV
;
6811 * adjust user setting (for HW filter setup)
6813 attr
->branch_sample_type
= mask
;
6815 /* privileged levels capture (kernel, hv): check permissions */
6816 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
6817 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6821 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
6822 ret
= perf_reg_validate(attr
->sample_regs_user
);
6827 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
6828 if (!arch_perf_have_user_stack_dump())
6832 * We have __u32 type for the size, but so far
6833 * we can only use __u16 as maximum due to the
6834 * __u16 sample size limit.
6836 if (attr
->sample_stack_user
>= USHRT_MAX
)
6838 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
6846 put_user(sizeof(*attr
), &uattr
->size
);
6852 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
6854 struct ring_buffer
*rb
= NULL
, *old_rb
= NULL
;
6860 /* don't allow circular references */
6861 if (event
== output_event
)
6865 * Don't allow cross-cpu buffers
6867 if (output_event
->cpu
!= event
->cpu
)
6871 * If its not a per-cpu rb, it must be the same task.
6873 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
6877 mutex_lock(&event
->mmap_mutex
);
6878 /* Can't redirect output if we've got an active mmap() */
6879 if (atomic_read(&event
->mmap_count
))
6885 /* get the rb we want to redirect to */
6886 rb
= ring_buffer_get(output_event
);
6892 ring_buffer_detach(event
, old_rb
);
6895 ring_buffer_attach(event
, rb
);
6897 rcu_assign_pointer(event
->rb
, rb
);
6900 ring_buffer_put(old_rb
);
6902 * Since we detached before setting the new rb, so that we
6903 * could attach the new rb, we could have missed a wakeup.
6906 wake_up_all(&event
->waitq
);
6911 mutex_unlock(&event
->mmap_mutex
);
6918 * sys_perf_event_open - open a performance event, associate it to a task/cpu
6920 * @attr_uptr: event_id type attributes for monitoring/sampling
6923 * @group_fd: group leader event fd
6925 SYSCALL_DEFINE5(perf_event_open
,
6926 struct perf_event_attr __user
*, attr_uptr
,
6927 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
6929 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
6930 struct perf_event
*event
, *sibling
;
6931 struct perf_event_attr attr
;
6932 struct perf_event_context
*ctx
;
6933 struct file
*event_file
= NULL
;
6934 struct fd group
= {NULL
, 0};
6935 struct task_struct
*task
= NULL
;
6941 /* for future expandability... */
6942 if (flags
& ~PERF_FLAG_ALL
)
6945 err
= perf_copy_attr(attr_uptr
, &attr
);
6949 if (!attr
.exclude_kernel
) {
6950 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6955 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
6960 * In cgroup mode, the pid argument is used to pass the fd
6961 * opened to the cgroup directory in cgroupfs. The cpu argument
6962 * designates the cpu on which to monitor threads from that
6965 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
6968 event_fd
= get_unused_fd();
6972 if (group_fd
!= -1) {
6973 err
= perf_fget_light(group_fd
, &group
);
6976 group_leader
= group
.file
->private_data
;
6977 if (flags
& PERF_FLAG_FD_OUTPUT
)
6978 output_event
= group_leader
;
6979 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6980 group_leader
= NULL
;
6983 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6984 task
= find_lively_task_by_vpid(pid
);
6986 err
= PTR_ERR(task
);
6993 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
6995 if (IS_ERR(event
)) {
6996 err
= PTR_ERR(event
);
7000 if (flags
& PERF_FLAG_PID_CGROUP
) {
7001 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
7003 __free_event(event
);
7008 account_event(event
);
7011 * Special case software events and allow them to be part of
7012 * any hardware group.
7017 (is_software_event(event
) != is_software_event(group_leader
))) {
7018 if (is_software_event(event
)) {
7020 * If event and group_leader are not both a software
7021 * event, and event is, then group leader is not.
7023 * Allow the addition of software events to !software
7024 * groups, this is safe because software events never
7027 pmu
= group_leader
->pmu
;
7028 } else if (is_software_event(group_leader
) &&
7029 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
7031 * In case the group is a pure software group, and we
7032 * try to add a hardware event, move the whole group to
7033 * the hardware context.
7040 * Get the target context (task or percpu):
7042 ctx
= find_get_context(pmu
, task
, event
->cpu
);
7049 put_task_struct(task
);
7054 * Look up the group leader (we will attach this event to it):
7060 * Do not allow a recursive hierarchy (this new sibling
7061 * becoming part of another group-sibling):
7063 if (group_leader
->group_leader
!= group_leader
)
7066 * Do not allow to attach to a group in a different
7067 * task or CPU context:
7070 if (group_leader
->ctx
->type
!= ctx
->type
)
7073 if (group_leader
->ctx
!= ctx
)
7078 * Only a group leader can be exclusive or pinned
7080 if (attr
.exclusive
|| attr
.pinned
)
7085 err
= perf_event_set_output(event
, output_event
);
7090 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
7091 if (IS_ERR(event_file
)) {
7092 err
= PTR_ERR(event_file
);
7097 struct perf_event_context
*gctx
= group_leader
->ctx
;
7099 mutex_lock(&gctx
->mutex
);
7100 perf_remove_from_context(group_leader
);
7103 * Removing from the context ends up with disabled
7104 * event. What we want here is event in the initial
7105 * startup state, ready to be add into new context.
7107 perf_event__state_init(group_leader
);
7108 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
7110 perf_remove_from_context(sibling
);
7111 perf_event__state_init(sibling
);
7114 mutex_unlock(&gctx
->mutex
);
7118 WARN_ON_ONCE(ctx
->parent_ctx
);
7119 mutex_lock(&ctx
->mutex
);
7123 perf_install_in_context(ctx
, group_leader
, event
->cpu
);
7125 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
7127 perf_install_in_context(ctx
, sibling
, event
->cpu
);
7132 perf_install_in_context(ctx
, event
, event
->cpu
);
7134 perf_unpin_context(ctx
);
7135 mutex_unlock(&ctx
->mutex
);
7139 event
->owner
= current
;
7141 mutex_lock(¤t
->perf_event_mutex
);
7142 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
7143 mutex_unlock(¤t
->perf_event_mutex
);
7146 * Precalculate sample_data sizes
7148 perf_event__header_size(event
);
7149 perf_event__id_header_size(event
);
7152 * Drop the reference on the group_event after placing the
7153 * new event on the sibling_list. This ensures destruction
7154 * of the group leader will find the pointer to itself in
7155 * perf_group_detach().
7158 fd_install(event_fd
, event_file
);
7162 perf_unpin_context(ctx
);
7169 put_task_struct(task
);
7173 put_unused_fd(event_fd
);
7178 * perf_event_create_kernel_counter
7180 * @attr: attributes of the counter to create
7181 * @cpu: cpu in which the counter is bound
7182 * @task: task to profile (NULL for percpu)
7185 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
7186 struct task_struct
*task
,
7187 perf_overflow_handler_t overflow_handler
,
7190 struct perf_event_context
*ctx
;
7191 struct perf_event
*event
;
7195 * Get the target context (task or percpu):
7198 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
7199 overflow_handler
, context
);
7200 if (IS_ERR(event
)) {
7201 err
= PTR_ERR(event
);
7205 account_event(event
);
7207 ctx
= find_get_context(event
->pmu
, task
, cpu
);
7213 WARN_ON_ONCE(ctx
->parent_ctx
);
7214 mutex_lock(&ctx
->mutex
);
7215 perf_install_in_context(ctx
, event
, cpu
);
7217 perf_unpin_context(ctx
);
7218 mutex_unlock(&ctx
->mutex
);
7225 return ERR_PTR(err
);
7227 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
7229 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
7231 struct perf_event_context
*src_ctx
;
7232 struct perf_event_context
*dst_ctx
;
7233 struct perf_event
*event
, *tmp
;
7236 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
7237 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
7239 mutex_lock(&src_ctx
->mutex
);
7240 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
7242 perf_remove_from_context(event
);
7243 unaccount_event_cpu(event
, src_cpu
);
7245 list_add(&event
->migrate_entry
, &events
);
7247 mutex_unlock(&src_ctx
->mutex
);
7251 mutex_lock(&dst_ctx
->mutex
);
7252 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
7253 list_del(&event
->migrate_entry
);
7254 if (event
->state
>= PERF_EVENT_STATE_OFF
)
7255 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7256 account_event_cpu(event
, dst_cpu
);
7257 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
7260 mutex_unlock(&dst_ctx
->mutex
);
7262 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
7264 static void sync_child_event(struct perf_event
*child_event
,
7265 struct task_struct
*child
)
7267 struct perf_event
*parent_event
= child_event
->parent
;
7270 if (child_event
->attr
.inherit_stat
)
7271 perf_event_read_event(child_event
, child
);
7273 child_val
= perf_event_count(child_event
);
7276 * Add back the child's count to the parent's count:
7278 atomic64_add(child_val
, &parent_event
->child_count
);
7279 atomic64_add(child_event
->total_time_enabled
,
7280 &parent_event
->child_total_time_enabled
);
7281 atomic64_add(child_event
->total_time_running
,
7282 &parent_event
->child_total_time_running
);
7285 * Remove this event from the parent's list
7287 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7288 mutex_lock(&parent_event
->child_mutex
);
7289 list_del_init(&child_event
->child_list
);
7290 mutex_unlock(&parent_event
->child_mutex
);
7293 * Release the parent event, if this was the last
7296 put_event(parent_event
);
7300 __perf_event_exit_task(struct perf_event
*child_event
,
7301 struct perf_event_context
*child_ctx
,
7302 struct task_struct
*child
)
7304 if (child_event
->parent
) {
7305 raw_spin_lock_irq(&child_ctx
->lock
);
7306 perf_group_detach(child_event
);
7307 raw_spin_unlock_irq(&child_ctx
->lock
);
7310 perf_remove_from_context(child_event
);
7313 * It can happen that the parent exits first, and has events
7314 * that are still around due to the child reference. These
7315 * events need to be zapped.
7317 if (child_event
->parent
) {
7318 sync_child_event(child_event
, child
);
7319 free_event(child_event
);
7323 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
7325 struct perf_event
*child_event
, *tmp
;
7326 struct perf_event_context
*child_ctx
;
7327 unsigned long flags
;
7329 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
7330 perf_event_task(child
, NULL
, 0);
7334 local_irq_save(flags
);
7336 * We can't reschedule here because interrupts are disabled,
7337 * and either child is current or it is a task that can't be
7338 * scheduled, so we are now safe from rescheduling changing
7341 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
7344 * Take the context lock here so that if find_get_context is
7345 * reading child->perf_event_ctxp, we wait until it has
7346 * incremented the context's refcount before we do put_ctx below.
7348 raw_spin_lock(&child_ctx
->lock
);
7349 task_ctx_sched_out(child_ctx
);
7350 child
->perf_event_ctxp
[ctxn
] = NULL
;
7352 * If this context is a clone; unclone it so it can't get
7353 * swapped to another process while we're removing all
7354 * the events from it.
7356 unclone_ctx(child_ctx
);
7357 update_context_time(child_ctx
);
7358 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
7361 * Report the task dead after unscheduling the events so that we
7362 * won't get any samples after PERF_RECORD_EXIT. We can however still
7363 * get a few PERF_RECORD_READ events.
7365 perf_event_task(child
, child_ctx
, 0);
7368 * We can recurse on the same lock type through:
7370 * __perf_event_exit_task()
7371 * sync_child_event()
7373 * mutex_lock(&ctx->mutex)
7375 * But since its the parent context it won't be the same instance.
7377 mutex_lock(&child_ctx
->mutex
);
7380 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
7382 __perf_event_exit_task(child_event
, child_ctx
, child
);
7384 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
7386 __perf_event_exit_task(child_event
, child_ctx
, child
);
7389 * If the last event was a group event, it will have appended all
7390 * its siblings to the list, but we obtained 'tmp' before that which
7391 * will still point to the list head terminating the iteration.
7393 if (!list_empty(&child_ctx
->pinned_groups
) ||
7394 !list_empty(&child_ctx
->flexible_groups
))
7397 mutex_unlock(&child_ctx
->mutex
);
7403 * When a child task exits, feed back event values to parent events.
7405 void perf_event_exit_task(struct task_struct
*child
)
7407 struct perf_event
*event
, *tmp
;
7410 mutex_lock(&child
->perf_event_mutex
);
7411 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
7413 list_del_init(&event
->owner_entry
);
7416 * Ensure the list deletion is visible before we clear
7417 * the owner, closes a race against perf_release() where
7418 * we need to serialize on the owner->perf_event_mutex.
7421 event
->owner
= NULL
;
7423 mutex_unlock(&child
->perf_event_mutex
);
7425 for_each_task_context_nr(ctxn
)
7426 perf_event_exit_task_context(child
, ctxn
);
7429 static void perf_free_event(struct perf_event
*event
,
7430 struct perf_event_context
*ctx
)
7432 struct perf_event
*parent
= event
->parent
;
7434 if (WARN_ON_ONCE(!parent
))
7437 mutex_lock(&parent
->child_mutex
);
7438 list_del_init(&event
->child_list
);
7439 mutex_unlock(&parent
->child_mutex
);
7443 perf_group_detach(event
);
7444 list_del_event(event
, ctx
);
7449 * free an unexposed, unused context as created by inheritance by
7450 * perf_event_init_task below, used by fork() in case of fail.
7452 void perf_event_free_task(struct task_struct
*task
)
7454 struct perf_event_context
*ctx
;
7455 struct perf_event
*event
, *tmp
;
7458 for_each_task_context_nr(ctxn
) {
7459 ctx
= task
->perf_event_ctxp
[ctxn
];
7463 mutex_lock(&ctx
->mutex
);
7465 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
7467 perf_free_event(event
, ctx
);
7469 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
7471 perf_free_event(event
, ctx
);
7473 if (!list_empty(&ctx
->pinned_groups
) ||
7474 !list_empty(&ctx
->flexible_groups
))
7477 mutex_unlock(&ctx
->mutex
);
7483 void perf_event_delayed_put(struct task_struct
*task
)
7487 for_each_task_context_nr(ctxn
)
7488 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
7492 * inherit a event from parent task to child task:
7494 static struct perf_event
*
7495 inherit_event(struct perf_event
*parent_event
,
7496 struct task_struct
*parent
,
7497 struct perf_event_context
*parent_ctx
,
7498 struct task_struct
*child
,
7499 struct perf_event
*group_leader
,
7500 struct perf_event_context
*child_ctx
)
7502 struct perf_event
*child_event
;
7503 unsigned long flags
;
7506 * Instead of creating recursive hierarchies of events,
7507 * we link inherited events back to the original parent,
7508 * which has a filp for sure, which we use as the reference
7511 if (parent_event
->parent
)
7512 parent_event
= parent_event
->parent
;
7514 child_event
= perf_event_alloc(&parent_event
->attr
,
7517 group_leader
, parent_event
,
7519 if (IS_ERR(child_event
))
7522 if (!atomic_long_inc_not_zero(&parent_event
->refcount
)) {
7523 free_event(child_event
);
7530 * Make the child state follow the state of the parent event,
7531 * not its attr.disabled bit. We hold the parent's mutex,
7532 * so we won't race with perf_event_{en, dis}able_family.
7534 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
7535 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
7537 child_event
->state
= PERF_EVENT_STATE_OFF
;
7539 if (parent_event
->attr
.freq
) {
7540 u64 sample_period
= parent_event
->hw
.sample_period
;
7541 struct hw_perf_event
*hwc
= &child_event
->hw
;
7543 hwc
->sample_period
= sample_period
;
7544 hwc
->last_period
= sample_period
;
7546 local64_set(&hwc
->period_left
, sample_period
);
7549 child_event
->ctx
= child_ctx
;
7550 child_event
->overflow_handler
= parent_event
->overflow_handler
;
7551 child_event
->overflow_handler_context
7552 = parent_event
->overflow_handler_context
;
7555 * Precalculate sample_data sizes
7557 perf_event__header_size(child_event
);
7558 perf_event__id_header_size(child_event
);
7561 * Link it up in the child's context:
7563 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
7564 add_event_to_ctx(child_event
, child_ctx
);
7565 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
7568 * Link this into the parent event's child list
7570 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7571 mutex_lock(&parent_event
->child_mutex
);
7572 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
7573 mutex_unlock(&parent_event
->child_mutex
);
7578 static int inherit_group(struct perf_event
*parent_event
,
7579 struct task_struct
*parent
,
7580 struct perf_event_context
*parent_ctx
,
7581 struct task_struct
*child
,
7582 struct perf_event_context
*child_ctx
)
7584 struct perf_event
*leader
;
7585 struct perf_event
*sub
;
7586 struct perf_event
*child_ctr
;
7588 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
7589 child
, NULL
, child_ctx
);
7591 return PTR_ERR(leader
);
7592 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
7593 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
7594 child
, leader
, child_ctx
);
7595 if (IS_ERR(child_ctr
))
7596 return PTR_ERR(child_ctr
);
7602 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
7603 struct perf_event_context
*parent_ctx
,
7604 struct task_struct
*child
, int ctxn
,
7608 struct perf_event_context
*child_ctx
;
7610 if (!event
->attr
.inherit
) {
7615 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7618 * This is executed from the parent task context, so
7619 * inherit events that have been marked for cloning.
7620 * First allocate and initialize a context for the
7624 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
7628 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
7631 ret
= inherit_group(event
, parent
, parent_ctx
,
7641 * Initialize the perf_event context in task_struct
7643 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
7645 struct perf_event_context
*child_ctx
, *parent_ctx
;
7646 struct perf_event_context
*cloned_ctx
;
7647 struct perf_event
*event
;
7648 struct task_struct
*parent
= current
;
7649 int inherited_all
= 1;
7650 unsigned long flags
;
7653 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
7657 * If the parent's context is a clone, pin it so it won't get
7660 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
7663 * No need to check if parent_ctx != NULL here; since we saw
7664 * it non-NULL earlier, the only reason for it to become NULL
7665 * is if we exit, and since we're currently in the middle of
7666 * a fork we can't be exiting at the same time.
7670 * Lock the parent list. No need to lock the child - not PID
7671 * hashed yet and not running, so nobody can access it.
7673 mutex_lock(&parent_ctx
->mutex
);
7676 * We dont have to disable NMIs - we are only looking at
7677 * the list, not manipulating it:
7679 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
7680 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7681 child
, ctxn
, &inherited_all
);
7687 * We can't hold ctx->lock when iterating the ->flexible_group list due
7688 * to allocations, but we need to prevent rotation because
7689 * rotate_ctx() will change the list from interrupt context.
7691 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7692 parent_ctx
->rotate_disable
= 1;
7693 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7695 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
7696 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7697 child
, ctxn
, &inherited_all
);
7702 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7703 parent_ctx
->rotate_disable
= 0;
7705 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7707 if (child_ctx
&& inherited_all
) {
7709 * Mark the child context as a clone of the parent
7710 * context, or of whatever the parent is a clone of.
7712 * Note that if the parent is a clone, the holding of
7713 * parent_ctx->lock avoids it from being uncloned.
7715 cloned_ctx
= parent_ctx
->parent_ctx
;
7717 child_ctx
->parent_ctx
= cloned_ctx
;
7718 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
7720 child_ctx
->parent_ctx
= parent_ctx
;
7721 child_ctx
->parent_gen
= parent_ctx
->generation
;
7723 get_ctx(child_ctx
->parent_ctx
);
7726 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7727 mutex_unlock(&parent_ctx
->mutex
);
7729 perf_unpin_context(parent_ctx
);
7730 put_ctx(parent_ctx
);
7736 * Initialize the perf_event context in task_struct
7738 int perf_event_init_task(struct task_struct
*child
)
7742 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7743 mutex_init(&child
->perf_event_mutex
);
7744 INIT_LIST_HEAD(&child
->perf_event_list
);
7746 for_each_task_context_nr(ctxn
) {
7747 ret
= perf_event_init_context(child
, ctxn
);
7755 static void __init
perf_event_init_all_cpus(void)
7757 struct swevent_htable
*swhash
;
7760 for_each_possible_cpu(cpu
) {
7761 swhash
= &per_cpu(swevent_htable
, cpu
);
7762 mutex_init(&swhash
->hlist_mutex
);
7763 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7767 static void perf_event_init_cpu(int cpu
)
7769 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7771 mutex_lock(&swhash
->hlist_mutex
);
7772 if (swhash
->hlist_refcount
> 0) {
7773 struct swevent_hlist
*hlist
;
7775 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7777 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7779 mutex_unlock(&swhash
->hlist_mutex
);
7782 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7783 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7785 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7787 WARN_ON(!irqs_disabled());
7789 list_del_init(&cpuctx
->rotation_list
);
7792 static void __perf_event_exit_context(void *__info
)
7794 struct perf_event_context
*ctx
= __info
;
7795 struct perf_event
*event
, *tmp
;
7797 perf_pmu_rotate_stop(ctx
->pmu
);
7799 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
7800 __perf_remove_from_context(event
);
7801 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
7802 __perf_remove_from_context(event
);
7805 static void perf_event_exit_cpu_context(int cpu
)
7807 struct perf_event_context
*ctx
;
7811 idx
= srcu_read_lock(&pmus_srcu
);
7812 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7813 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
7815 mutex_lock(&ctx
->mutex
);
7816 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
7817 mutex_unlock(&ctx
->mutex
);
7819 srcu_read_unlock(&pmus_srcu
, idx
);
7822 static void perf_event_exit_cpu(int cpu
)
7824 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7826 mutex_lock(&swhash
->hlist_mutex
);
7827 swevent_hlist_release(swhash
);
7828 mutex_unlock(&swhash
->hlist_mutex
);
7830 perf_event_exit_cpu_context(cpu
);
7833 static inline void perf_event_exit_cpu(int cpu
) { }
7837 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
7841 for_each_online_cpu(cpu
)
7842 perf_event_exit_cpu(cpu
);
7848 * Run the perf reboot notifier at the very last possible moment so that
7849 * the generic watchdog code runs as long as possible.
7851 static struct notifier_block perf_reboot_notifier
= {
7852 .notifier_call
= perf_reboot
,
7853 .priority
= INT_MIN
,
7857 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
7859 unsigned int cpu
= (long)hcpu
;
7861 switch (action
& ~CPU_TASKS_FROZEN
) {
7863 case CPU_UP_PREPARE
:
7864 case CPU_DOWN_FAILED
:
7865 perf_event_init_cpu(cpu
);
7868 case CPU_UP_CANCELED
:
7869 case CPU_DOWN_PREPARE
:
7870 perf_event_exit_cpu(cpu
);
7879 void __init
perf_event_init(void)
7885 perf_event_init_all_cpus();
7886 init_srcu_struct(&pmus_srcu
);
7887 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
7888 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
7889 perf_pmu_register(&perf_task_clock
, NULL
, -1);
7891 perf_cpu_notifier(perf_cpu_notify
);
7892 register_reboot_notifier(&perf_reboot_notifier
);
7894 ret
= init_hw_breakpoint();
7895 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
7897 /* do not patch jump label more than once per second */
7898 jump_label_rate_limit(&perf_sched_events
, HZ
);
7901 * Build time assertion that we keep the data_head at the intended
7902 * location. IOW, validation we got the __reserved[] size right.
7904 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
7908 static int __init
perf_event_sysfs_init(void)
7913 mutex_lock(&pmus_lock
);
7915 ret
= bus_register(&pmu_bus
);
7919 list_for_each_entry(pmu
, &pmus
, entry
) {
7920 if (!pmu
->name
|| pmu
->type
< 0)
7923 ret
= pmu_dev_alloc(pmu
);
7924 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
7926 pmu_bus_running
= 1;
7930 mutex_unlock(&pmus_lock
);
7934 device_initcall(perf_event_sysfs_init
);
7936 #ifdef CONFIG_CGROUP_PERF
7937 static struct cgroup_subsys_state
*
7938 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
7940 struct perf_cgroup
*jc
;
7942 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
7944 return ERR_PTR(-ENOMEM
);
7946 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
7949 return ERR_PTR(-ENOMEM
);
7955 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
7957 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
7959 free_percpu(jc
->info
);
7963 static int __perf_cgroup_move(void *info
)
7965 struct task_struct
*task
= info
;
7966 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
7970 static void perf_cgroup_attach(struct cgroup_subsys_state
*css
,
7971 struct cgroup_taskset
*tset
)
7973 struct task_struct
*task
;
7975 cgroup_taskset_for_each(task
, css
, tset
)
7976 task_function_call(task
, __perf_cgroup_move
, task
);
7979 static void perf_cgroup_exit(struct cgroup_subsys_state
*css
,
7980 struct cgroup_subsys_state
*old_css
,
7981 struct task_struct
*task
)
7984 * cgroup_exit() is called in the copy_process() failure path.
7985 * Ignore this case since the task hasn't ran yet, this avoids
7986 * trying to poke a half freed task state from generic code.
7988 if (!(task
->flags
& PF_EXITING
))
7991 task_function_call(task
, __perf_cgroup_move
, task
);
7994 struct cgroup_subsys perf_subsys
= {
7995 .name
= "perf_event",
7996 .subsys_id
= perf_subsys_id
,
7997 .css_alloc
= perf_cgroup_css_alloc
,
7998 .css_free
= perf_cgroup_css_free
,
7999 .exit
= perf_cgroup_exit
,
8000 .attach
= perf_cgroup_attach
,
8002 #endif /* CONFIG_CGROUP_PERF */