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
;
905 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
908 * only top level events have the pid namespace they were created in
911 event
= event
->parent
;
913 return task_tgid_nr_ns(p
, event
->ns
);
916 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
919 * only top level events have the pid namespace they were created in
922 event
= event
->parent
;
924 return task_pid_nr_ns(p
, event
->ns
);
928 * If we inherit events we want to return the parent event id
931 static u64
primary_event_id(struct perf_event
*event
)
936 id
= event
->parent
->id
;
942 * Get the perf_event_context for a task and lock it.
943 * This has to cope with with the fact that until it is locked,
944 * the context could get moved to another task.
946 static struct perf_event_context
*
947 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
949 struct perf_event_context
*ctx
;
953 * One of the few rules of preemptible RCU is that one cannot do
954 * rcu_read_unlock() while holding a scheduler (or nested) lock when
955 * part of the read side critical section was preemptible -- see
956 * rcu_read_unlock_special().
958 * Since ctx->lock nests under rq->lock we must ensure the entire read
959 * side critical section is non-preemptible.
963 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
966 * If this context is a clone of another, it might
967 * get swapped for another underneath us by
968 * perf_event_task_sched_out, though the
969 * rcu_read_lock() protects us from any context
970 * getting freed. Lock the context and check if it
971 * got swapped before we could get the lock, and retry
972 * if so. If we locked the right context, then it
973 * can't get swapped on us any more.
975 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
976 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
977 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
983 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
984 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
994 * Get the context for a task and increment its pin_count so it
995 * can't get swapped to another task. This also increments its
996 * reference count so that the context can't get freed.
998 static struct perf_event_context
*
999 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1001 struct perf_event_context
*ctx
;
1002 unsigned long flags
;
1004 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1007 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1012 static void perf_unpin_context(struct perf_event_context
*ctx
)
1014 unsigned long flags
;
1016 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1018 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1022 * Update the record of the current time in a context.
1024 static void update_context_time(struct perf_event_context
*ctx
)
1026 u64 now
= perf_clock();
1028 ctx
->time
+= now
- ctx
->timestamp
;
1029 ctx
->timestamp
= now
;
1032 static u64
perf_event_time(struct perf_event
*event
)
1034 struct perf_event_context
*ctx
= event
->ctx
;
1036 if (is_cgroup_event(event
))
1037 return perf_cgroup_event_time(event
);
1039 return ctx
? ctx
->time
: 0;
1043 * Update the total_time_enabled and total_time_running fields for a event.
1044 * The caller of this function needs to hold the ctx->lock.
1046 static void update_event_times(struct perf_event
*event
)
1048 struct perf_event_context
*ctx
= event
->ctx
;
1051 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1052 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1055 * in cgroup mode, time_enabled represents
1056 * the time the event was enabled AND active
1057 * tasks were in the monitored cgroup. This is
1058 * independent of the activity of the context as
1059 * there may be a mix of cgroup and non-cgroup events.
1061 * That is why we treat cgroup events differently
1064 if (is_cgroup_event(event
))
1065 run_end
= perf_cgroup_event_time(event
);
1066 else if (ctx
->is_active
)
1067 run_end
= ctx
->time
;
1069 run_end
= event
->tstamp_stopped
;
1071 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1073 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1074 run_end
= event
->tstamp_stopped
;
1076 run_end
= perf_event_time(event
);
1078 event
->total_time_running
= run_end
- event
->tstamp_running
;
1083 * Update total_time_enabled and total_time_running for all events in a group.
1085 static void update_group_times(struct perf_event
*leader
)
1087 struct perf_event
*event
;
1089 update_event_times(leader
);
1090 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1091 update_event_times(event
);
1094 static struct list_head
*
1095 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1097 if (event
->attr
.pinned
)
1098 return &ctx
->pinned_groups
;
1100 return &ctx
->flexible_groups
;
1104 * Add a event from the lists for its context.
1105 * Must be called with ctx->mutex and ctx->lock held.
1108 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1110 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1111 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1114 * If we're a stand alone event or group leader, we go to the context
1115 * list, group events are kept attached to the group so that
1116 * perf_group_detach can, at all times, locate all siblings.
1118 if (event
->group_leader
== event
) {
1119 struct list_head
*list
;
1121 if (is_software_event(event
))
1122 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1124 list
= ctx_group_list(event
, ctx
);
1125 list_add_tail(&event
->group_entry
, list
);
1128 if (is_cgroup_event(event
))
1131 if (has_branch_stack(event
))
1132 ctx
->nr_branch_stack
++;
1134 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1135 if (!ctx
->nr_events
)
1136 perf_pmu_rotate_start(ctx
->pmu
);
1138 if (event
->attr
.inherit_stat
)
1145 * Initialize event state based on the perf_event_attr::disabled.
1147 static inline void perf_event__state_init(struct perf_event
*event
)
1149 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1150 PERF_EVENT_STATE_INACTIVE
;
1154 * Called at perf_event creation and when events are attached/detached from a
1157 static void perf_event__read_size(struct perf_event
*event
)
1159 int entry
= sizeof(u64
); /* value */
1163 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1164 size
+= sizeof(u64
);
1166 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1167 size
+= sizeof(u64
);
1169 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1170 entry
+= sizeof(u64
);
1172 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1173 nr
+= event
->group_leader
->nr_siblings
;
1174 size
+= sizeof(u64
);
1178 event
->read_size
= size
;
1181 static void perf_event__header_size(struct perf_event
*event
)
1183 struct perf_sample_data
*data
;
1184 u64 sample_type
= event
->attr
.sample_type
;
1187 perf_event__read_size(event
);
1189 if (sample_type
& PERF_SAMPLE_IP
)
1190 size
+= sizeof(data
->ip
);
1192 if (sample_type
& PERF_SAMPLE_ADDR
)
1193 size
+= sizeof(data
->addr
);
1195 if (sample_type
& PERF_SAMPLE_PERIOD
)
1196 size
+= sizeof(data
->period
);
1198 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1199 size
+= sizeof(data
->weight
);
1201 if (sample_type
& PERF_SAMPLE_READ
)
1202 size
+= event
->read_size
;
1204 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1205 size
+= sizeof(data
->data_src
.val
);
1207 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1208 size
+= sizeof(data
->txn
);
1210 event
->header_size
= size
;
1213 static void perf_event__id_header_size(struct perf_event
*event
)
1215 struct perf_sample_data
*data
;
1216 u64 sample_type
= event
->attr
.sample_type
;
1219 if (sample_type
& PERF_SAMPLE_TID
)
1220 size
+= sizeof(data
->tid_entry
);
1222 if (sample_type
& PERF_SAMPLE_TIME
)
1223 size
+= sizeof(data
->time
);
1225 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1226 size
+= sizeof(data
->id
);
1228 if (sample_type
& PERF_SAMPLE_ID
)
1229 size
+= sizeof(data
->id
);
1231 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1232 size
+= sizeof(data
->stream_id
);
1234 if (sample_type
& PERF_SAMPLE_CPU
)
1235 size
+= sizeof(data
->cpu_entry
);
1237 event
->id_header_size
= size
;
1240 static void perf_group_attach(struct perf_event
*event
)
1242 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1245 * We can have double attach due to group movement in perf_event_open.
1247 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1250 event
->attach_state
|= PERF_ATTACH_GROUP
;
1252 if (group_leader
== event
)
1255 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1256 !is_software_event(event
))
1257 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1259 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1260 group_leader
->nr_siblings
++;
1262 perf_event__header_size(group_leader
);
1264 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1265 perf_event__header_size(pos
);
1269 * Remove a event from the lists for its context.
1270 * Must be called with ctx->mutex and ctx->lock held.
1273 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1275 struct perf_cpu_context
*cpuctx
;
1277 * We can have double detach due to exit/hot-unplug + close.
1279 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1282 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1284 if (is_cgroup_event(event
)) {
1286 cpuctx
= __get_cpu_context(ctx
);
1288 * if there are no more cgroup events
1289 * then cler cgrp to avoid stale pointer
1290 * in update_cgrp_time_from_cpuctx()
1292 if (!ctx
->nr_cgroups
)
1293 cpuctx
->cgrp
= NULL
;
1296 if (has_branch_stack(event
))
1297 ctx
->nr_branch_stack
--;
1300 if (event
->attr
.inherit_stat
)
1303 list_del_rcu(&event
->event_entry
);
1305 if (event
->group_leader
== event
)
1306 list_del_init(&event
->group_entry
);
1308 update_group_times(event
);
1311 * If event was in error state, then keep it
1312 * that way, otherwise bogus counts will be
1313 * returned on read(). The only way to get out
1314 * of error state is by explicit re-enabling
1317 if (event
->state
> PERF_EVENT_STATE_OFF
)
1318 event
->state
= PERF_EVENT_STATE_OFF
;
1323 static void perf_group_detach(struct perf_event
*event
)
1325 struct perf_event
*sibling
, *tmp
;
1326 struct list_head
*list
= NULL
;
1329 * We can have double detach due to exit/hot-unplug + close.
1331 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1334 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1337 * If this is a sibling, remove it from its group.
1339 if (event
->group_leader
!= event
) {
1340 list_del_init(&event
->group_entry
);
1341 event
->group_leader
->nr_siblings
--;
1345 if (!list_empty(&event
->group_entry
))
1346 list
= &event
->group_entry
;
1349 * If this was a group event with sibling events then
1350 * upgrade the siblings to singleton events by adding them
1351 * to whatever list we are on.
1353 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1355 list_move_tail(&sibling
->group_entry
, list
);
1356 sibling
->group_leader
= sibling
;
1358 /* Inherit group flags from the previous leader */
1359 sibling
->group_flags
= event
->group_flags
;
1363 perf_event__header_size(event
->group_leader
);
1365 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1366 perf_event__header_size(tmp
);
1370 event_filter_match(struct perf_event
*event
)
1372 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1373 && perf_cgroup_match(event
);
1377 event_sched_out(struct perf_event
*event
,
1378 struct perf_cpu_context
*cpuctx
,
1379 struct perf_event_context
*ctx
)
1381 u64 tstamp
= perf_event_time(event
);
1384 * An event which could not be activated because of
1385 * filter mismatch still needs to have its timings
1386 * maintained, otherwise bogus information is return
1387 * via read() for time_enabled, time_running:
1389 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1390 && !event_filter_match(event
)) {
1391 delta
= tstamp
- event
->tstamp_stopped
;
1392 event
->tstamp_running
+= delta
;
1393 event
->tstamp_stopped
= tstamp
;
1396 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1399 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1400 if (event
->pending_disable
) {
1401 event
->pending_disable
= 0;
1402 event
->state
= PERF_EVENT_STATE_OFF
;
1404 event
->tstamp_stopped
= tstamp
;
1405 event
->pmu
->del(event
, 0);
1408 if (!is_software_event(event
))
1409 cpuctx
->active_oncpu
--;
1411 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1413 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1414 cpuctx
->exclusive
= 0;
1418 group_sched_out(struct perf_event
*group_event
,
1419 struct perf_cpu_context
*cpuctx
,
1420 struct perf_event_context
*ctx
)
1422 struct perf_event
*event
;
1423 int state
= group_event
->state
;
1425 event_sched_out(group_event
, cpuctx
, ctx
);
1428 * Schedule out siblings (if any):
1430 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1431 event_sched_out(event
, cpuctx
, ctx
);
1433 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1434 cpuctx
->exclusive
= 0;
1438 * Cross CPU call to remove a performance event
1440 * We disable the event on the hardware level first. After that we
1441 * remove it from the context list.
1443 static int __perf_remove_from_context(void *info
)
1445 struct perf_event
*event
= info
;
1446 struct perf_event_context
*ctx
= event
->ctx
;
1447 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1449 raw_spin_lock(&ctx
->lock
);
1450 event_sched_out(event
, cpuctx
, ctx
);
1451 list_del_event(event
, ctx
);
1452 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1454 cpuctx
->task_ctx
= NULL
;
1456 raw_spin_unlock(&ctx
->lock
);
1463 * Remove the event from a task's (or a CPU's) list of events.
1465 * CPU events are removed with a smp call. For task events we only
1466 * call when the task is on a CPU.
1468 * If event->ctx is a cloned context, callers must make sure that
1469 * every task struct that event->ctx->task could possibly point to
1470 * remains valid. This is OK when called from perf_release since
1471 * that only calls us on the top-level context, which can't be a clone.
1472 * When called from perf_event_exit_task, it's OK because the
1473 * context has been detached from its task.
1475 static void perf_remove_from_context(struct perf_event
*event
)
1477 struct perf_event_context
*ctx
= event
->ctx
;
1478 struct task_struct
*task
= ctx
->task
;
1480 lockdep_assert_held(&ctx
->mutex
);
1484 * Per cpu events are removed via an smp call and
1485 * the removal is always successful.
1487 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1492 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1495 raw_spin_lock_irq(&ctx
->lock
);
1497 * If we failed to find a running task, but find the context active now
1498 * that we've acquired the ctx->lock, retry.
1500 if (ctx
->is_active
) {
1501 raw_spin_unlock_irq(&ctx
->lock
);
1506 * Since the task isn't running, its safe to remove the event, us
1507 * holding the ctx->lock ensures the task won't get scheduled in.
1509 list_del_event(event
, ctx
);
1510 raw_spin_unlock_irq(&ctx
->lock
);
1514 * Cross CPU call to disable a performance event
1516 int __perf_event_disable(void *info
)
1518 struct perf_event
*event
= info
;
1519 struct perf_event_context
*ctx
= event
->ctx
;
1520 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1523 * If this is a per-task event, need to check whether this
1524 * event's task is the current task on this cpu.
1526 * Can trigger due to concurrent perf_event_context_sched_out()
1527 * flipping contexts around.
1529 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1532 raw_spin_lock(&ctx
->lock
);
1535 * If the event is on, turn it off.
1536 * If it is in error state, leave it in error state.
1538 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1539 update_context_time(ctx
);
1540 update_cgrp_time_from_event(event
);
1541 update_group_times(event
);
1542 if (event
== event
->group_leader
)
1543 group_sched_out(event
, cpuctx
, ctx
);
1545 event_sched_out(event
, cpuctx
, ctx
);
1546 event
->state
= PERF_EVENT_STATE_OFF
;
1549 raw_spin_unlock(&ctx
->lock
);
1557 * If event->ctx is a cloned context, callers must make sure that
1558 * every task struct that event->ctx->task could possibly point to
1559 * remains valid. This condition is satisifed when called through
1560 * perf_event_for_each_child or perf_event_for_each because they
1561 * hold the top-level event's child_mutex, so any descendant that
1562 * goes to exit will block in sync_child_event.
1563 * When called from perf_pending_event it's OK because event->ctx
1564 * is the current context on this CPU and preemption is disabled,
1565 * hence we can't get into perf_event_task_sched_out for this context.
1567 void perf_event_disable(struct perf_event
*event
)
1569 struct perf_event_context
*ctx
= event
->ctx
;
1570 struct task_struct
*task
= ctx
->task
;
1574 * Disable the event on the cpu that it's on
1576 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1581 if (!task_function_call(task
, __perf_event_disable
, event
))
1584 raw_spin_lock_irq(&ctx
->lock
);
1586 * If the event is still active, we need to retry the cross-call.
1588 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1589 raw_spin_unlock_irq(&ctx
->lock
);
1591 * Reload the task pointer, it might have been changed by
1592 * a concurrent perf_event_context_sched_out().
1599 * Since we have the lock this context can't be scheduled
1600 * in, so we can change the state safely.
1602 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1603 update_group_times(event
);
1604 event
->state
= PERF_EVENT_STATE_OFF
;
1606 raw_spin_unlock_irq(&ctx
->lock
);
1608 EXPORT_SYMBOL_GPL(perf_event_disable
);
1610 static void perf_set_shadow_time(struct perf_event
*event
,
1611 struct perf_event_context
*ctx
,
1615 * use the correct time source for the time snapshot
1617 * We could get by without this by leveraging the
1618 * fact that to get to this function, the caller
1619 * has most likely already called update_context_time()
1620 * and update_cgrp_time_xx() and thus both timestamp
1621 * are identical (or very close). Given that tstamp is,
1622 * already adjusted for cgroup, we could say that:
1623 * tstamp - ctx->timestamp
1625 * tstamp - cgrp->timestamp.
1627 * Then, in perf_output_read(), the calculation would
1628 * work with no changes because:
1629 * - event is guaranteed scheduled in
1630 * - no scheduled out in between
1631 * - thus the timestamp would be the same
1633 * But this is a bit hairy.
1635 * So instead, we have an explicit cgroup call to remain
1636 * within the time time source all along. We believe it
1637 * is cleaner and simpler to understand.
1639 if (is_cgroup_event(event
))
1640 perf_cgroup_set_shadow_time(event
, tstamp
);
1642 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1645 #define MAX_INTERRUPTS (~0ULL)
1647 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1650 event_sched_in(struct perf_event
*event
,
1651 struct perf_cpu_context
*cpuctx
,
1652 struct perf_event_context
*ctx
)
1654 u64 tstamp
= perf_event_time(event
);
1656 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1659 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1660 event
->oncpu
= smp_processor_id();
1663 * Unthrottle events, since we scheduled we might have missed several
1664 * ticks already, also for a heavily scheduling task there is little
1665 * guarantee it'll get a tick in a timely manner.
1667 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1668 perf_log_throttle(event
, 1);
1669 event
->hw
.interrupts
= 0;
1673 * The new state must be visible before we turn it on in the hardware:
1677 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1678 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1683 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1685 perf_set_shadow_time(event
, ctx
, tstamp
);
1687 if (!is_software_event(event
))
1688 cpuctx
->active_oncpu
++;
1690 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1693 if (event
->attr
.exclusive
)
1694 cpuctx
->exclusive
= 1;
1700 group_sched_in(struct perf_event
*group_event
,
1701 struct perf_cpu_context
*cpuctx
,
1702 struct perf_event_context
*ctx
)
1704 struct perf_event
*event
, *partial_group
= NULL
;
1705 struct pmu
*pmu
= group_event
->pmu
;
1706 u64 now
= ctx
->time
;
1707 bool simulate
= false;
1709 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1712 pmu
->start_txn(pmu
);
1714 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1715 pmu
->cancel_txn(pmu
);
1716 perf_cpu_hrtimer_restart(cpuctx
);
1721 * Schedule in siblings as one group (if any):
1723 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1724 if (event_sched_in(event
, cpuctx
, ctx
)) {
1725 partial_group
= event
;
1730 if (!pmu
->commit_txn(pmu
))
1735 * Groups can be scheduled in as one unit only, so undo any
1736 * partial group before returning:
1737 * The events up to the failed event are scheduled out normally,
1738 * tstamp_stopped will be updated.
1740 * The failed events and the remaining siblings need to have
1741 * their timings updated as if they had gone thru event_sched_in()
1742 * and event_sched_out(). This is required to get consistent timings
1743 * across the group. This also takes care of the case where the group
1744 * could never be scheduled by ensuring tstamp_stopped is set to mark
1745 * the time the event was actually stopped, such that time delta
1746 * calculation in update_event_times() is correct.
1748 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1749 if (event
== partial_group
)
1753 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1754 event
->tstamp_stopped
= now
;
1756 event_sched_out(event
, cpuctx
, ctx
);
1759 event_sched_out(group_event
, cpuctx
, ctx
);
1761 pmu
->cancel_txn(pmu
);
1763 perf_cpu_hrtimer_restart(cpuctx
);
1769 * Work out whether we can put this event group on the CPU now.
1771 static int group_can_go_on(struct perf_event
*event
,
1772 struct perf_cpu_context
*cpuctx
,
1776 * Groups consisting entirely of software events can always go on.
1778 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1781 * If an exclusive group is already on, no other hardware
1784 if (cpuctx
->exclusive
)
1787 * If this group is exclusive and there are already
1788 * events on the CPU, it can't go on.
1790 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1793 * Otherwise, try to add it if all previous groups were able
1799 static void add_event_to_ctx(struct perf_event
*event
,
1800 struct perf_event_context
*ctx
)
1802 u64 tstamp
= perf_event_time(event
);
1804 list_add_event(event
, ctx
);
1805 perf_group_attach(event
);
1806 event
->tstamp_enabled
= tstamp
;
1807 event
->tstamp_running
= tstamp
;
1808 event
->tstamp_stopped
= tstamp
;
1811 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
1813 ctx_sched_in(struct perf_event_context
*ctx
,
1814 struct perf_cpu_context
*cpuctx
,
1815 enum event_type_t event_type
,
1816 struct task_struct
*task
);
1818 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
1819 struct perf_event_context
*ctx
,
1820 struct task_struct
*task
)
1822 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
1824 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
1825 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
1827 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
1831 * Cross CPU call to install and enable a performance event
1833 * Must be called with ctx->mutex held
1835 static int __perf_install_in_context(void *info
)
1837 struct perf_event
*event
= info
;
1838 struct perf_event_context
*ctx
= event
->ctx
;
1839 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1840 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
1841 struct task_struct
*task
= current
;
1843 perf_ctx_lock(cpuctx
, task_ctx
);
1844 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1847 * If there was an active task_ctx schedule it out.
1850 task_ctx_sched_out(task_ctx
);
1853 * If the context we're installing events in is not the
1854 * active task_ctx, flip them.
1856 if (ctx
->task
&& task_ctx
!= ctx
) {
1858 raw_spin_unlock(&task_ctx
->lock
);
1859 raw_spin_lock(&ctx
->lock
);
1864 cpuctx
->task_ctx
= task_ctx
;
1865 task
= task_ctx
->task
;
1868 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
1870 update_context_time(ctx
);
1872 * update cgrp time only if current cgrp
1873 * matches event->cgrp. Must be done before
1874 * calling add_event_to_ctx()
1876 update_cgrp_time_from_event(event
);
1878 add_event_to_ctx(event
, ctx
);
1881 * Schedule everything back in
1883 perf_event_sched_in(cpuctx
, task_ctx
, task
);
1885 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1886 perf_ctx_unlock(cpuctx
, task_ctx
);
1892 * Attach a performance event to a context
1894 * First we add the event to the list with the hardware enable bit
1895 * in event->hw_config cleared.
1897 * If the event is attached to a task which is on a CPU we use a smp
1898 * call to enable it in the task context. The task might have been
1899 * scheduled away, but we check this in the smp call again.
1902 perf_install_in_context(struct perf_event_context
*ctx
,
1903 struct perf_event
*event
,
1906 struct task_struct
*task
= ctx
->task
;
1908 lockdep_assert_held(&ctx
->mutex
);
1911 if (event
->cpu
!= -1)
1916 * Per cpu events are installed via an smp call and
1917 * the install is always successful.
1919 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1924 if (!task_function_call(task
, __perf_install_in_context
, event
))
1927 raw_spin_lock_irq(&ctx
->lock
);
1929 * If we failed to find a running task, but find the context active now
1930 * that we've acquired the ctx->lock, retry.
1932 if (ctx
->is_active
) {
1933 raw_spin_unlock_irq(&ctx
->lock
);
1938 * Since the task isn't running, its safe to add the event, us holding
1939 * the ctx->lock ensures the task won't get scheduled in.
1941 add_event_to_ctx(event
, ctx
);
1942 raw_spin_unlock_irq(&ctx
->lock
);
1946 * Put a event into inactive state and update time fields.
1947 * Enabling the leader of a group effectively enables all
1948 * the group members that aren't explicitly disabled, so we
1949 * have to update their ->tstamp_enabled also.
1950 * Note: this works for group members as well as group leaders
1951 * since the non-leader members' sibling_lists will be empty.
1953 static void __perf_event_mark_enabled(struct perf_event
*event
)
1955 struct perf_event
*sub
;
1956 u64 tstamp
= perf_event_time(event
);
1958 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1959 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1960 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1961 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1962 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1967 * Cross CPU call to enable a performance event
1969 static int __perf_event_enable(void *info
)
1971 struct perf_event
*event
= info
;
1972 struct perf_event_context
*ctx
= event
->ctx
;
1973 struct perf_event
*leader
= event
->group_leader
;
1974 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1978 * There's a time window between 'ctx->is_active' check
1979 * in perf_event_enable function and this place having:
1981 * - ctx->lock unlocked
1983 * where the task could be killed and 'ctx' deactivated
1984 * by perf_event_exit_task.
1986 if (!ctx
->is_active
)
1989 raw_spin_lock(&ctx
->lock
);
1990 update_context_time(ctx
);
1992 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1996 * set current task's cgroup time reference point
1998 perf_cgroup_set_timestamp(current
, ctx
);
2000 __perf_event_mark_enabled(event
);
2002 if (!event_filter_match(event
)) {
2003 if (is_cgroup_event(event
))
2004 perf_cgroup_defer_enabled(event
);
2009 * If the event is in a group and isn't the group leader,
2010 * then don't put it on unless the group is on.
2012 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2015 if (!group_can_go_on(event
, cpuctx
, 1)) {
2018 if (event
== leader
)
2019 err
= group_sched_in(event
, cpuctx
, ctx
);
2021 err
= event_sched_in(event
, cpuctx
, ctx
);
2026 * If this event can't go on and it's part of a
2027 * group, then the whole group has to come off.
2029 if (leader
!= event
) {
2030 group_sched_out(leader
, cpuctx
, ctx
);
2031 perf_cpu_hrtimer_restart(cpuctx
);
2033 if (leader
->attr
.pinned
) {
2034 update_group_times(leader
);
2035 leader
->state
= PERF_EVENT_STATE_ERROR
;
2040 raw_spin_unlock(&ctx
->lock
);
2048 * If event->ctx is a cloned context, callers must make sure that
2049 * every task struct that event->ctx->task could possibly point to
2050 * remains valid. This condition is satisfied when called through
2051 * perf_event_for_each_child or perf_event_for_each as described
2052 * for perf_event_disable.
2054 void perf_event_enable(struct perf_event
*event
)
2056 struct perf_event_context
*ctx
= event
->ctx
;
2057 struct task_struct
*task
= ctx
->task
;
2061 * Enable the event on the cpu that it's on
2063 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
2067 raw_spin_lock_irq(&ctx
->lock
);
2068 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2072 * If the event is in error state, clear that first.
2073 * That way, if we see the event in error state below, we
2074 * know that it has gone back into error state, as distinct
2075 * from the task having been scheduled away before the
2076 * cross-call arrived.
2078 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2079 event
->state
= PERF_EVENT_STATE_OFF
;
2082 if (!ctx
->is_active
) {
2083 __perf_event_mark_enabled(event
);
2087 raw_spin_unlock_irq(&ctx
->lock
);
2089 if (!task_function_call(task
, __perf_event_enable
, event
))
2092 raw_spin_lock_irq(&ctx
->lock
);
2095 * If the context is active and the event is still off,
2096 * we need to retry the cross-call.
2098 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
2100 * task could have been flipped by a concurrent
2101 * perf_event_context_sched_out()
2108 raw_spin_unlock_irq(&ctx
->lock
);
2110 EXPORT_SYMBOL_GPL(perf_event_enable
);
2112 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2115 * not supported on inherited events
2117 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2120 atomic_add(refresh
, &event
->event_limit
);
2121 perf_event_enable(event
);
2125 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2127 static void ctx_sched_out(struct perf_event_context
*ctx
,
2128 struct perf_cpu_context
*cpuctx
,
2129 enum event_type_t event_type
)
2131 struct perf_event
*event
;
2132 int is_active
= ctx
->is_active
;
2134 ctx
->is_active
&= ~event_type
;
2135 if (likely(!ctx
->nr_events
))
2138 update_context_time(ctx
);
2139 update_cgrp_time_from_cpuctx(cpuctx
);
2140 if (!ctx
->nr_active
)
2143 perf_pmu_disable(ctx
->pmu
);
2144 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2145 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2146 group_sched_out(event
, cpuctx
, ctx
);
2149 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2150 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2151 group_sched_out(event
, cpuctx
, ctx
);
2153 perf_pmu_enable(ctx
->pmu
);
2157 * Test whether two contexts are equivalent, i.e. whether they have both been
2158 * cloned from the same version of the same context.
2160 * Equivalence is measured using a generation number in the context that is
2161 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2162 * and list_del_event().
2164 static int context_equiv(struct perf_event_context
*ctx1
,
2165 struct perf_event_context
*ctx2
)
2167 /* Pinning disables the swap optimization */
2168 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2171 /* If ctx1 is the parent of ctx2 */
2172 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2175 /* If ctx2 is the parent of ctx1 */
2176 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2180 * If ctx1 and ctx2 have the same parent; we flatten the parent
2181 * hierarchy, see perf_event_init_context().
2183 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2184 ctx1
->parent_gen
== ctx2
->parent_gen
)
2191 static void __perf_event_sync_stat(struct perf_event
*event
,
2192 struct perf_event
*next_event
)
2196 if (!event
->attr
.inherit_stat
)
2200 * Update the event value, we cannot use perf_event_read()
2201 * because we're in the middle of a context switch and have IRQs
2202 * disabled, which upsets smp_call_function_single(), however
2203 * we know the event must be on the current CPU, therefore we
2204 * don't need to use it.
2206 switch (event
->state
) {
2207 case PERF_EVENT_STATE_ACTIVE
:
2208 event
->pmu
->read(event
);
2211 case PERF_EVENT_STATE_INACTIVE
:
2212 update_event_times(event
);
2220 * In order to keep per-task stats reliable we need to flip the event
2221 * values when we flip the contexts.
2223 value
= local64_read(&next_event
->count
);
2224 value
= local64_xchg(&event
->count
, value
);
2225 local64_set(&next_event
->count
, value
);
2227 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2228 swap(event
->total_time_running
, next_event
->total_time_running
);
2231 * Since we swizzled the values, update the user visible data too.
2233 perf_event_update_userpage(event
);
2234 perf_event_update_userpage(next_event
);
2237 #define list_next_entry(pos, member) \
2238 list_entry(pos->member.next, typeof(*pos), member)
2240 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2241 struct perf_event_context
*next_ctx
)
2243 struct perf_event
*event
, *next_event
;
2248 update_context_time(ctx
);
2250 event
= list_first_entry(&ctx
->event_list
,
2251 struct perf_event
, event_entry
);
2253 next_event
= list_first_entry(&next_ctx
->event_list
,
2254 struct perf_event
, event_entry
);
2256 while (&event
->event_entry
!= &ctx
->event_list
&&
2257 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2259 __perf_event_sync_stat(event
, next_event
);
2261 event
= list_next_entry(event
, event_entry
);
2262 next_event
= list_next_entry(next_event
, event_entry
);
2266 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2267 struct task_struct
*next
)
2269 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2270 struct perf_event_context
*next_ctx
;
2271 struct perf_event_context
*parent
, *next_parent
;
2272 struct perf_cpu_context
*cpuctx
;
2278 cpuctx
= __get_cpu_context(ctx
);
2279 if (!cpuctx
->task_ctx
)
2283 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2287 parent
= rcu_dereference(ctx
->parent_ctx
);
2288 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2290 /* If neither context have a parent context; they cannot be clones. */
2291 if (!parent
&& !next_parent
)
2294 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2296 * Looks like the two contexts are clones, so we might be
2297 * able to optimize the context switch. We lock both
2298 * contexts and check that they are clones under the
2299 * lock (including re-checking that neither has been
2300 * uncloned in the meantime). It doesn't matter which
2301 * order we take the locks because no other cpu could
2302 * be trying to lock both of these tasks.
2304 raw_spin_lock(&ctx
->lock
);
2305 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2306 if (context_equiv(ctx
, next_ctx
)) {
2308 * XXX do we need a memory barrier of sorts
2309 * wrt to rcu_dereference() of perf_event_ctxp
2311 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2312 next
->perf_event_ctxp
[ctxn
] = ctx
;
2314 next_ctx
->task
= task
;
2317 perf_event_sync_stat(ctx
, next_ctx
);
2319 raw_spin_unlock(&next_ctx
->lock
);
2320 raw_spin_unlock(&ctx
->lock
);
2326 raw_spin_lock(&ctx
->lock
);
2327 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2328 cpuctx
->task_ctx
= NULL
;
2329 raw_spin_unlock(&ctx
->lock
);
2333 #define for_each_task_context_nr(ctxn) \
2334 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2337 * Called from scheduler to remove the events of the current task,
2338 * with interrupts disabled.
2340 * We stop each event and update the event value in event->count.
2342 * This does not protect us against NMI, but disable()
2343 * sets the disabled bit in the control field of event _before_
2344 * accessing the event control register. If a NMI hits, then it will
2345 * not restart the event.
2347 void __perf_event_task_sched_out(struct task_struct
*task
,
2348 struct task_struct
*next
)
2352 for_each_task_context_nr(ctxn
)
2353 perf_event_context_sched_out(task
, ctxn
, next
);
2356 * if cgroup events exist on this CPU, then we need
2357 * to check if we have to switch out PMU state.
2358 * cgroup event are system-wide mode only
2360 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2361 perf_cgroup_sched_out(task
, next
);
2364 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2366 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2368 if (!cpuctx
->task_ctx
)
2371 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2374 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2375 cpuctx
->task_ctx
= NULL
;
2379 * Called with IRQs disabled
2381 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2382 enum event_type_t event_type
)
2384 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2388 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2389 struct perf_cpu_context
*cpuctx
)
2391 struct perf_event
*event
;
2393 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2394 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2396 if (!event_filter_match(event
))
2399 /* may need to reset tstamp_enabled */
2400 if (is_cgroup_event(event
))
2401 perf_cgroup_mark_enabled(event
, ctx
);
2403 if (group_can_go_on(event
, cpuctx
, 1))
2404 group_sched_in(event
, cpuctx
, ctx
);
2407 * If this pinned group hasn't been scheduled,
2408 * put it in error state.
2410 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2411 update_group_times(event
);
2412 event
->state
= PERF_EVENT_STATE_ERROR
;
2418 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2419 struct perf_cpu_context
*cpuctx
)
2421 struct perf_event
*event
;
2424 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2425 /* Ignore events in OFF or ERROR state */
2426 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2429 * Listen to the 'cpu' scheduling filter constraint
2432 if (!event_filter_match(event
))
2435 /* may need to reset tstamp_enabled */
2436 if (is_cgroup_event(event
))
2437 perf_cgroup_mark_enabled(event
, ctx
);
2439 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2440 if (group_sched_in(event
, cpuctx
, ctx
))
2447 ctx_sched_in(struct perf_event_context
*ctx
,
2448 struct perf_cpu_context
*cpuctx
,
2449 enum event_type_t event_type
,
2450 struct task_struct
*task
)
2453 int is_active
= ctx
->is_active
;
2455 ctx
->is_active
|= event_type
;
2456 if (likely(!ctx
->nr_events
))
2460 ctx
->timestamp
= now
;
2461 perf_cgroup_set_timestamp(task
, ctx
);
2463 * First go through the list and put on any pinned groups
2464 * in order to give them the best chance of going on.
2466 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2467 ctx_pinned_sched_in(ctx
, cpuctx
);
2469 /* Then walk through the lower prio flexible groups */
2470 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2471 ctx_flexible_sched_in(ctx
, cpuctx
);
2474 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2475 enum event_type_t event_type
,
2476 struct task_struct
*task
)
2478 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2480 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2483 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2484 struct task_struct
*task
)
2486 struct perf_cpu_context
*cpuctx
;
2488 cpuctx
= __get_cpu_context(ctx
);
2489 if (cpuctx
->task_ctx
== ctx
)
2492 perf_ctx_lock(cpuctx
, ctx
);
2493 perf_pmu_disable(ctx
->pmu
);
2495 * We want to keep the following priority order:
2496 * cpu pinned (that don't need to move), task pinned,
2497 * cpu flexible, task flexible.
2499 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2502 cpuctx
->task_ctx
= ctx
;
2504 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2506 perf_pmu_enable(ctx
->pmu
);
2507 perf_ctx_unlock(cpuctx
, ctx
);
2510 * Since these rotations are per-cpu, we need to ensure the
2511 * cpu-context we got scheduled on is actually rotating.
2513 perf_pmu_rotate_start(ctx
->pmu
);
2517 * When sampling the branck stack in system-wide, it may be necessary
2518 * to flush the stack on context switch. This happens when the branch
2519 * stack does not tag its entries with the pid of the current task.
2520 * Otherwise it becomes impossible to associate a branch entry with a
2521 * task. This ambiguity is more likely to appear when the branch stack
2522 * supports priv level filtering and the user sets it to monitor only
2523 * at the user level (which could be a useful measurement in system-wide
2524 * mode). In that case, the risk is high of having a branch stack with
2525 * branch from multiple tasks. Flushing may mean dropping the existing
2526 * entries or stashing them somewhere in the PMU specific code layer.
2528 * This function provides the context switch callback to the lower code
2529 * layer. It is invoked ONLY when there is at least one system-wide context
2530 * with at least one active event using taken branch sampling.
2532 static void perf_branch_stack_sched_in(struct task_struct
*prev
,
2533 struct task_struct
*task
)
2535 struct perf_cpu_context
*cpuctx
;
2537 unsigned long flags
;
2539 /* no need to flush branch stack if not changing task */
2543 local_irq_save(flags
);
2547 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2548 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2551 * check if the context has at least one
2552 * event using PERF_SAMPLE_BRANCH_STACK
2554 if (cpuctx
->ctx
.nr_branch_stack
> 0
2555 && pmu
->flush_branch_stack
) {
2557 pmu
= cpuctx
->ctx
.pmu
;
2559 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2561 perf_pmu_disable(pmu
);
2563 pmu
->flush_branch_stack();
2565 perf_pmu_enable(pmu
);
2567 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2573 local_irq_restore(flags
);
2577 * Called from scheduler to add the events of the current task
2578 * with interrupts disabled.
2580 * We restore the event value and then enable it.
2582 * This does not protect us against NMI, but enable()
2583 * sets the enabled bit in the control field of event _before_
2584 * accessing the event control register. If a NMI hits, then it will
2585 * keep the event running.
2587 void __perf_event_task_sched_in(struct task_struct
*prev
,
2588 struct task_struct
*task
)
2590 struct perf_event_context
*ctx
;
2593 for_each_task_context_nr(ctxn
) {
2594 ctx
= task
->perf_event_ctxp
[ctxn
];
2598 perf_event_context_sched_in(ctx
, task
);
2601 * if cgroup events exist on this CPU, then we need
2602 * to check if we have to switch in PMU state.
2603 * cgroup event are system-wide mode only
2605 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2606 perf_cgroup_sched_in(prev
, task
);
2608 /* check for system-wide branch_stack events */
2609 if (atomic_read(&__get_cpu_var(perf_branch_stack_events
)))
2610 perf_branch_stack_sched_in(prev
, task
);
2613 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2615 u64 frequency
= event
->attr
.sample_freq
;
2616 u64 sec
= NSEC_PER_SEC
;
2617 u64 divisor
, dividend
;
2619 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2621 count_fls
= fls64(count
);
2622 nsec_fls
= fls64(nsec
);
2623 frequency_fls
= fls64(frequency
);
2627 * We got @count in @nsec, with a target of sample_freq HZ
2628 * the target period becomes:
2631 * period = -------------------
2632 * @nsec * sample_freq
2637 * Reduce accuracy by one bit such that @a and @b converge
2638 * to a similar magnitude.
2640 #define REDUCE_FLS(a, b) \
2642 if (a##_fls > b##_fls) { \
2652 * Reduce accuracy until either term fits in a u64, then proceed with
2653 * the other, so that finally we can do a u64/u64 division.
2655 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2656 REDUCE_FLS(nsec
, frequency
);
2657 REDUCE_FLS(sec
, count
);
2660 if (count_fls
+ sec_fls
> 64) {
2661 divisor
= nsec
* frequency
;
2663 while (count_fls
+ sec_fls
> 64) {
2664 REDUCE_FLS(count
, sec
);
2668 dividend
= count
* sec
;
2670 dividend
= count
* sec
;
2672 while (nsec_fls
+ frequency_fls
> 64) {
2673 REDUCE_FLS(nsec
, frequency
);
2677 divisor
= nsec
* frequency
;
2683 return div64_u64(dividend
, divisor
);
2686 static DEFINE_PER_CPU(int, perf_throttled_count
);
2687 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2689 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2691 struct hw_perf_event
*hwc
= &event
->hw
;
2692 s64 period
, sample_period
;
2695 period
= perf_calculate_period(event
, nsec
, count
);
2697 delta
= (s64
)(period
- hwc
->sample_period
);
2698 delta
= (delta
+ 7) / 8; /* low pass filter */
2700 sample_period
= hwc
->sample_period
+ delta
;
2705 hwc
->sample_period
= sample_period
;
2707 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2709 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2711 local64_set(&hwc
->period_left
, 0);
2714 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2719 * combine freq adjustment with unthrottling to avoid two passes over the
2720 * events. At the same time, make sure, having freq events does not change
2721 * the rate of unthrottling as that would introduce bias.
2723 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2726 struct perf_event
*event
;
2727 struct hw_perf_event
*hwc
;
2728 u64 now
, period
= TICK_NSEC
;
2732 * only need to iterate over all events iff:
2733 * - context have events in frequency mode (needs freq adjust)
2734 * - there are events to unthrottle on this cpu
2736 if (!(ctx
->nr_freq
|| needs_unthr
))
2739 raw_spin_lock(&ctx
->lock
);
2740 perf_pmu_disable(ctx
->pmu
);
2742 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2743 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2746 if (!event_filter_match(event
))
2751 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
2752 hwc
->interrupts
= 0;
2753 perf_log_throttle(event
, 1);
2754 event
->pmu
->start(event
, 0);
2757 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2761 * stop the event and update event->count
2763 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2765 now
= local64_read(&event
->count
);
2766 delta
= now
- hwc
->freq_count_stamp
;
2767 hwc
->freq_count_stamp
= now
;
2771 * reload only if value has changed
2772 * we have stopped the event so tell that
2773 * to perf_adjust_period() to avoid stopping it
2777 perf_adjust_period(event
, period
, delta
, false);
2779 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
2782 perf_pmu_enable(ctx
->pmu
);
2783 raw_spin_unlock(&ctx
->lock
);
2787 * Round-robin a context's events:
2789 static void rotate_ctx(struct perf_event_context
*ctx
)
2792 * Rotate the first entry last of non-pinned groups. Rotation might be
2793 * disabled by the inheritance code.
2795 if (!ctx
->rotate_disable
)
2796 list_rotate_left(&ctx
->flexible_groups
);
2800 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2801 * because they're strictly cpu affine and rotate_start is called with IRQs
2802 * disabled, while rotate_context is called from IRQ context.
2804 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2806 struct perf_event_context
*ctx
= NULL
;
2807 int rotate
= 0, remove
= 1;
2809 if (cpuctx
->ctx
.nr_events
) {
2811 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2815 ctx
= cpuctx
->task_ctx
;
2816 if (ctx
&& ctx
->nr_events
) {
2818 if (ctx
->nr_events
!= ctx
->nr_active
)
2825 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2826 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2828 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2830 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
2832 rotate_ctx(&cpuctx
->ctx
);
2836 perf_event_sched_in(cpuctx
, ctx
, current
);
2838 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2839 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2842 list_del_init(&cpuctx
->rotation_list
);
2847 #ifdef CONFIG_NO_HZ_FULL
2848 bool perf_event_can_stop_tick(void)
2850 if (atomic_read(&nr_freq_events
) ||
2851 __this_cpu_read(perf_throttled_count
))
2858 void perf_event_task_tick(void)
2860 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2861 struct perf_cpu_context
*cpuctx
, *tmp
;
2862 struct perf_event_context
*ctx
;
2865 WARN_ON(!irqs_disabled());
2867 __this_cpu_inc(perf_throttled_seq
);
2868 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
2870 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2872 perf_adjust_freq_unthr_context(ctx
, throttled
);
2874 ctx
= cpuctx
->task_ctx
;
2876 perf_adjust_freq_unthr_context(ctx
, throttled
);
2880 static int event_enable_on_exec(struct perf_event
*event
,
2881 struct perf_event_context
*ctx
)
2883 if (!event
->attr
.enable_on_exec
)
2886 event
->attr
.enable_on_exec
= 0;
2887 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2890 __perf_event_mark_enabled(event
);
2896 * Enable all of a task's events that have been marked enable-on-exec.
2897 * This expects task == current.
2899 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2901 struct perf_event
*event
;
2902 unsigned long flags
;
2906 local_irq_save(flags
);
2907 if (!ctx
|| !ctx
->nr_events
)
2911 * We must ctxsw out cgroup events to avoid conflict
2912 * when invoking perf_task_event_sched_in() later on
2913 * in this function. Otherwise we end up trying to
2914 * ctxswin cgroup events which are already scheduled
2917 perf_cgroup_sched_out(current
, NULL
);
2919 raw_spin_lock(&ctx
->lock
);
2920 task_ctx_sched_out(ctx
);
2922 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
2923 ret
= event_enable_on_exec(event
, ctx
);
2929 * Unclone this context if we enabled any event.
2934 raw_spin_unlock(&ctx
->lock
);
2937 * Also calls ctxswin for cgroup events, if any:
2939 perf_event_context_sched_in(ctx
, ctx
->task
);
2941 local_irq_restore(flags
);
2945 * Cross CPU call to read the hardware event
2947 static void __perf_event_read(void *info
)
2949 struct perf_event
*event
= info
;
2950 struct perf_event_context
*ctx
= event
->ctx
;
2951 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2954 * If this is a task context, we need to check whether it is
2955 * the current task context of this cpu. If not it has been
2956 * scheduled out before the smp call arrived. In that case
2957 * event->count would have been updated to a recent sample
2958 * when the event was scheduled out.
2960 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2963 raw_spin_lock(&ctx
->lock
);
2964 if (ctx
->is_active
) {
2965 update_context_time(ctx
);
2966 update_cgrp_time_from_event(event
);
2968 update_event_times(event
);
2969 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2970 event
->pmu
->read(event
);
2971 raw_spin_unlock(&ctx
->lock
);
2974 static inline u64
perf_event_count(struct perf_event
*event
)
2976 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2979 static u64
perf_event_read(struct perf_event
*event
)
2982 * If event is enabled and currently active on a CPU, update the
2983 * value in the event structure:
2985 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2986 smp_call_function_single(event
->oncpu
,
2987 __perf_event_read
, event
, 1);
2988 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2989 struct perf_event_context
*ctx
= event
->ctx
;
2990 unsigned long flags
;
2992 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2994 * may read while context is not active
2995 * (e.g., thread is blocked), in that case
2996 * we cannot update context time
2998 if (ctx
->is_active
) {
2999 update_context_time(ctx
);
3000 update_cgrp_time_from_event(event
);
3002 update_event_times(event
);
3003 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3006 return perf_event_count(event
);
3010 * Initialize the perf_event context in a task_struct:
3012 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3014 raw_spin_lock_init(&ctx
->lock
);
3015 mutex_init(&ctx
->mutex
);
3016 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3017 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3018 INIT_LIST_HEAD(&ctx
->event_list
);
3019 atomic_set(&ctx
->refcount
, 1);
3022 static struct perf_event_context
*
3023 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3025 struct perf_event_context
*ctx
;
3027 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3031 __perf_event_init_context(ctx
);
3034 get_task_struct(task
);
3041 static struct task_struct
*
3042 find_lively_task_by_vpid(pid_t vpid
)
3044 struct task_struct
*task
;
3051 task
= find_task_by_vpid(vpid
);
3053 get_task_struct(task
);
3057 return ERR_PTR(-ESRCH
);
3059 /* Reuse ptrace permission checks for now. */
3061 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3066 put_task_struct(task
);
3067 return ERR_PTR(err
);
3072 * Returns a matching context with refcount and pincount.
3074 static struct perf_event_context
*
3075 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
3077 struct perf_event_context
*ctx
;
3078 struct perf_cpu_context
*cpuctx
;
3079 unsigned long flags
;
3083 /* Must be root to operate on a CPU event: */
3084 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3085 return ERR_PTR(-EACCES
);
3088 * We could be clever and allow to attach a event to an
3089 * offline CPU and activate it when the CPU comes up, but
3092 if (!cpu_online(cpu
))
3093 return ERR_PTR(-ENODEV
);
3095 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3104 ctxn
= pmu
->task_ctx_nr
;
3109 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3113 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3115 ctx
= alloc_perf_context(pmu
, task
);
3121 mutex_lock(&task
->perf_event_mutex
);
3123 * If it has already passed perf_event_exit_task().
3124 * we must see PF_EXITING, it takes this mutex too.
3126 if (task
->flags
& PF_EXITING
)
3128 else if (task
->perf_event_ctxp
[ctxn
])
3133 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3135 mutex_unlock(&task
->perf_event_mutex
);
3137 if (unlikely(err
)) {
3149 return ERR_PTR(err
);
3152 static void perf_event_free_filter(struct perf_event
*event
);
3154 static void free_event_rcu(struct rcu_head
*head
)
3156 struct perf_event
*event
;
3158 event
= container_of(head
, struct perf_event
, rcu_head
);
3160 put_pid_ns(event
->ns
);
3161 perf_event_free_filter(event
);
3165 static void ring_buffer_put(struct ring_buffer
*rb
);
3166 static void ring_buffer_detach(struct perf_event
*event
, struct ring_buffer
*rb
);
3168 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3173 if (has_branch_stack(event
)) {
3174 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
3175 atomic_dec(&per_cpu(perf_branch_stack_events
, cpu
));
3177 if (is_cgroup_event(event
))
3178 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3181 static void unaccount_event(struct perf_event
*event
)
3186 if (event
->attach_state
& PERF_ATTACH_TASK
)
3187 static_key_slow_dec_deferred(&perf_sched_events
);
3188 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3189 atomic_dec(&nr_mmap_events
);
3190 if (event
->attr
.comm
)
3191 atomic_dec(&nr_comm_events
);
3192 if (event
->attr
.task
)
3193 atomic_dec(&nr_task_events
);
3194 if (event
->attr
.freq
)
3195 atomic_dec(&nr_freq_events
);
3196 if (is_cgroup_event(event
))
3197 static_key_slow_dec_deferred(&perf_sched_events
);
3198 if (has_branch_stack(event
))
3199 static_key_slow_dec_deferred(&perf_sched_events
);
3201 unaccount_event_cpu(event
, event
->cpu
);
3204 static void __free_event(struct perf_event
*event
)
3206 if (!event
->parent
) {
3207 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3208 put_callchain_buffers();
3212 event
->destroy(event
);
3215 put_ctx(event
->ctx
);
3217 call_rcu(&event
->rcu_head
, free_event_rcu
);
3219 static void free_event(struct perf_event
*event
)
3221 irq_work_sync(&event
->pending
);
3223 unaccount_event(event
);
3226 struct ring_buffer
*rb
;
3229 * Can happen when we close an event with re-directed output.
3231 * Since we have a 0 refcount, perf_mmap_close() will skip
3232 * over us; possibly making our ring_buffer_put() the last.
3234 mutex_lock(&event
->mmap_mutex
);
3237 rcu_assign_pointer(event
->rb
, NULL
);
3238 ring_buffer_detach(event
, rb
);
3239 ring_buffer_put(rb
); /* could be last */
3241 mutex_unlock(&event
->mmap_mutex
);
3244 if (is_cgroup_event(event
))
3245 perf_detach_cgroup(event
);
3248 __free_event(event
);
3251 int perf_event_release_kernel(struct perf_event
*event
)
3253 struct perf_event_context
*ctx
= event
->ctx
;
3255 WARN_ON_ONCE(ctx
->parent_ctx
);
3257 * There are two ways this annotation is useful:
3259 * 1) there is a lock recursion from perf_event_exit_task
3260 * see the comment there.
3262 * 2) there is a lock-inversion with mmap_sem through
3263 * perf_event_read_group(), which takes faults while
3264 * holding ctx->mutex, however this is called after
3265 * the last filedesc died, so there is no possibility
3266 * to trigger the AB-BA case.
3268 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
3269 raw_spin_lock_irq(&ctx
->lock
);
3270 perf_group_detach(event
);
3271 raw_spin_unlock_irq(&ctx
->lock
);
3272 perf_remove_from_context(event
);
3273 mutex_unlock(&ctx
->mutex
);
3279 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3282 * Called when the last reference to the file is gone.
3284 static void put_event(struct perf_event
*event
)
3286 struct task_struct
*owner
;
3288 if (!atomic_long_dec_and_test(&event
->refcount
))
3292 owner
= ACCESS_ONCE(event
->owner
);
3294 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3295 * !owner it means the list deletion is complete and we can indeed
3296 * free this event, otherwise we need to serialize on
3297 * owner->perf_event_mutex.
3299 smp_read_barrier_depends();
3302 * Since delayed_put_task_struct() also drops the last
3303 * task reference we can safely take a new reference
3304 * while holding the rcu_read_lock().
3306 get_task_struct(owner
);
3311 mutex_lock(&owner
->perf_event_mutex
);
3313 * We have to re-check the event->owner field, if it is cleared
3314 * we raced with perf_event_exit_task(), acquiring the mutex
3315 * ensured they're done, and we can proceed with freeing the
3319 list_del_init(&event
->owner_entry
);
3320 mutex_unlock(&owner
->perf_event_mutex
);
3321 put_task_struct(owner
);
3324 perf_event_release_kernel(event
);
3327 static int perf_release(struct inode
*inode
, struct file
*file
)
3329 put_event(file
->private_data
);
3333 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3335 struct perf_event
*child
;
3341 mutex_lock(&event
->child_mutex
);
3342 total
+= perf_event_read(event
);
3343 *enabled
+= event
->total_time_enabled
+
3344 atomic64_read(&event
->child_total_time_enabled
);
3345 *running
+= event
->total_time_running
+
3346 atomic64_read(&event
->child_total_time_running
);
3348 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3349 total
+= perf_event_read(child
);
3350 *enabled
+= child
->total_time_enabled
;
3351 *running
+= child
->total_time_running
;
3353 mutex_unlock(&event
->child_mutex
);
3357 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3359 static int perf_event_read_group(struct perf_event
*event
,
3360 u64 read_format
, char __user
*buf
)
3362 struct perf_event
*leader
= event
->group_leader
, *sub
;
3363 int n
= 0, size
= 0, ret
= -EFAULT
;
3364 struct perf_event_context
*ctx
= leader
->ctx
;
3366 u64 count
, enabled
, running
;
3368 mutex_lock(&ctx
->mutex
);
3369 count
= perf_event_read_value(leader
, &enabled
, &running
);
3371 values
[n
++] = 1 + leader
->nr_siblings
;
3372 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3373 values
[n
++] = enabled
;
3374 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3375 values
[n
++] = running
;
3376 values
[n
++] = count
;
3377 if (read_format
& PERF_FORMAT_ID
)
3378 values
[n
++] = primary_event_id(leader
);
3380 size
= n
* sizeof(u64
);
3382 if (copy_to_user(buf
, values
, size
))
3387 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3390 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3391 if (read_format
& PERF_FORMAT_ID
)
3392 values
[n
++] = primary_event_id(sub
);
3394 size
= n
* sizeof(u64
);
3396 if (copy_to_user(buf
+ ret
, values
, size
)) {
3404 mutex_unlock(&ctx
->mutex
);
3409 static int perf_event_read_one(struct perf_event
*event
,
3410 u64 read_format
, char __user
*buf
)
3412 u64 enabled
, running
;
3416 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3417 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3418 values
[n
++] = enabled
;
3419 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3420 values
[n
++] = running
;
3421 if (read_format
& PERF_FORMAT_ID
)
3422 values
[n
++] = primary_event_id(event
);
3424 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3427 return n
* sizeof(u64
);
3431 * Read the performance event - simple non blocking version for now
3434 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3436 u64 read_format
= event
->attr
.read_format
;
3440 * Return end-of-file for a read on a event that is in
3441 * error state (i.e. because it was pinned but it couldn't be
3442 * scheduled on to the CPU at some point).
3444 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3447 if (count
< event
->read_size
)
3450 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3451 if (read_format
& PERF_FORMAT_GROUP
)
3452 ret
= perf_event_read_group(event
, read_format
, buf
);
3454 ret
= perf_event_read_one(event
, read_format
, buf
);
3460 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3462 struct perf_event
*event
= file
->private_data
;
3464 return perf_read_hw(event
, buf
, count
);
3467 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3469 struct perf_event
*event
= file
->private_data
;
3470 struct ring_buffer
*rb
;
3471 unsigned int events
= POLL_HUP
;
3474 * Pin the event->rb by taking event->mmap_mutex; otherwise
3475 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
3477 mutex_lock(&event
->mmap_mutex
);
3480 events
= atomic_xchg(&rb
->poll
, 0);
3481 mutex_unlock(&event
->mmap_mutex
);
3483 poll_wait(file
, &event
->waitq
, wait
);
3488 static void perf_event_reset(struct perf_event
*event
)
3490 (void)perf_event_read(event
);
3491 local64_set(&event
->count
, 0);
3492 perf_event_update_userpage(event
);
3496 * Holding the top-level event's child_mutex means that any
3497 * descendant process that has inherited this event will block
3498 * in sync_child_event if it goes to exit, thus satisfying the
3499 * task existence requirements of perf_event_enable/disable.
3501 static void perf_event_for_each_child(struct perf_event
*event
,
3502 void (*func
)(struct perf_event
*))
3504 struct perf_event
*child
;
3506 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3507 mutex_lock(&event
->child_mutex
);
3509 list_for_each_entry(child
, &event
->child_list
, child_list
)
3511 mutex_unlock(&event
->child_mutex
);
3514 static void perf_event_for_each(struct perf_event
*event
,
3515 void (*func
)(struct perf_event
*))
3517 struct perf_event_context
*ctx
= event
->ctx
;
3518 struct perf_event
*sibling
;
3520 WARN_ON_ONCE(ctx
->parent_ctx
);
3521 mutex_lock(&ctx
->mutex
);
3522 event
= event
->group_leader
;
3524 perf_event_for_each_child(event
, func
);
3525 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3526 perf_event_for_each_child(sibling
, func
);
3527 mutex_unlock(&ctx
->mutex
);
3530 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3532 struct perf_event_context
*ctx
= event
->ctx
;
3536 if (!is_sampling_event(event
))
3539 if (copy_from_user(&value
, arg
, sizeof(value
)))
3545 raw_spin_lock_irq(&ctx
->lock
);
3546 if (event
->attr
.freq
) {
3547 if (value
> sysctl_perf_event_sample_rate
) {
3552 event
->attr
.sample_freq
= value
;
3554 event
->attr
.sample_period
= value
;
3555 event
->hw
.sample_period
= value
;
3558 raw_spin_unlock_irq(&ctx
->lock
);
3563 static const struct file_operations perf_fops
;
3565 static inline int perf_fget_light(int fd
, struct fd
*p
)
3567 struct fd f
= fdget(fd
);
3571 if (f
.file
->f_op
!= &perf_fops
) {
3579 static int perf_event_set_output(struct perf_event
*event
,
3580 struct perf_event
*output_event
);
3581 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3583 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3585 struct perf_event
*event
= file
->private_data
;
3586 void (*func
)(struct perf_event
*);
3590 case PERF_EVENT_IOC_ENABLE
:
3591 func
= perf_event_enable
;
3593 case PERF_EVENT_IOC_DISABLE
:
3594 func
= perf_event_disable
;
3596 case PERF_EVENT_IOC_RESET
:
3597 func
= perf_event_reset
;
3600 case PERF_EVENT_IOC_REFRESH
:
3601 return perf_event_refresh(event
, arg
);
3603 case PERF_EVENT_IOC_PERIOD
:
3604 return perf_event_period(event
, (u64 __user
*)arg
);
3606 case PERF_EVENT_IOC_ID
:
3608 u64 id
= primary_event_id(event
);
3610 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
3615 case PERF_EVENT_IOC_SET_OUTPUT
:
3619 struct perf_event
*output_event
;
3621 ret
= perf_fget_light(arg
, &output
);
3624 output_event
= output
.file
->private_data
;
3625 ret
= perf_event_set_output(event
, output_event
);
3628 ret
= perf_event_set_output(event
, NULL
);
3633 case PERF_EVENT_IOC_SET_FILTER
:
3634 return perf_event_set_filter(event
, (void __user
*)arg
);
3640 if (flags
& PERF_IOC_FLAG_GROUP
)
3641 perf_event_for_each(event
, func
);
3643 perf_event_for_each_child(event
, func
);
3648 int perf_event_task_enable(void)
3650 struct perf_event
*event
;
3652 mutex_lock(¤t
->perf_event_mutex
);
3653 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3654 perf_event_for_each_child(event
, perf_event_enable
);
3655 mutex_unlock(¤t
->perf_event_mutex
);
3660 int perf_event_task_disable(void)
3662 struct perf_event
*event
;
3664 mutex_lock(¤t
->perf_event_mutex
);
3665 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3666 perf_event_for_each_child(event
, perf_event_disable
);
3667 mutex_unlock(¤t
->perf_event_mutex
);
3672 static int perf_event_index(struct perf_event
*event
)
3674 if (event
->hw
.state
& PERF_HES_STOPPED
)
3677 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3680 return event
->pmu
->event_idx(event
);
3683 static void calc_timer_values(struct perf_event
*event
,
3690 *now
= perf_clock();
3691 ctx_time
= event
->shadow_ctx_time
+ *now
;
3692 *enabled
= ctx_time
- event
->tstamp_enabled
;
3693 *running
= ctx_time
- event
->tstamp_running
;
3696 static void perf_event_init_userpage(struct perf_event
*event
)
3698 struct perf_event_mmap_page
*userpg
;
3699 struct ring_buffer
*rb
;
3702 rb
= rcu_dereference(event
->rb
);
3706 userpg
= rb
->user_page
;
3708 /* Allow new userspace to detect that bit 0 is deprecated */
3709 userpg
->cap_bit0_is_deprecated
= 1;
3710 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
3716 void __weak
arch_perf_update_userpage(struct perf_event_mmap_page
*userpg
, u64 now
)
3721 * Callers need to ensure there can be no nesting of this function, otherwise
3722 * the seqlock logic goes bad. We can not serialize this because the arch
3723 * code calls this from NMI context.
3725 void perf_event_update_userpage(struct perf_event
*event
)
3727 struct perf_event_mmap_page
*userpg
;
3728 struct ring_buffer
*rb
;
3729 u64 enabled
, running
, now
;
3732 rb
= rcu_dereference(event
->rb
);
3737 * compute total_time_enabled, total_time_running
3738 * based on snapshot values taken when the event
3739 * was last scheduled in.
3741 * we cannot simply called update_context_time()
3742 * because of locking issue as we can be called in
3745 calc_timer_values(event
, &now
, &enabled
, &running
);
3747 userpg
= rb
->user_page
;
3749 * Disable preemption so as to not let the corresponding user-space
3750 * spin too long if we get preempted.
3755 userpg
->index
= perf_event_index(event
);
3756 userpg
->offset
= perf_event_count(event
);
3758 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3760 userpg
->time_enabled
= enabled
+
3761 atomic64_read(&event
->child_total_time_enabled
);
3763 userpg
->time_running
= running
+
3764 atomic64_read(&event
->child_total_time_running
);
3766 arch_perf_update_userpage(userpg
, now
);
3775 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3777 struct perf_event
*event
= vma
->vm_file
->private_data
;
3778 struct ring_buffer
*rb
;
3779 int ret
= VM_FAULT_SIGBUS
;
3781 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3782 if (vmf
->pgoff
== 0)
3788 rb
= rcu_dereference(event
->rb
);
3792 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3795 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3799 get_page(vmf
->page
);
3800 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3801 vmf
->page
->index
= vmf
->pgoff
;
3810 static void ring_buffer_attach(struct perf_event
*event
,
3811 struct ring_buffer
*rb
)
3813 unsigned long flags
;
3815 if (!list_empty(&event
->rb_entry
))
3818 spin_lock_irqsave(&rb
->event_lock
, flags
);
3819 if (list_empty(&event
->rb_entry
))
3820 list_add(&event
->rb_entry
, &rb
->event_list
);
3821 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3824 static void ring_buffer_detach(struct perf_event
*event
, struct ring_buffer
*rb
)
3826 unsigned long flags
;
3828 if (list_empty(&event
->rb_entry
))
3831 spin_lock_irqsave(&rb
->event_lock
, flags
);
3832 list_del_init(&event
->rb_entry
);
3833 wake_up_all(&event
->waitq
);
3834 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3837 static void ring_buffer_wakeup(struct perf_event
*event
)
3839 struct ring_buffer
*rb
;
3842 rb
= rcu_dereference(event
->rb
);
3844 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
3845 wake_up_all(&event
->waitq
);
3850 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3852 struct ring_buffer
*rb
;
3854 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3858 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3860 struct ring_buffer
*rb
;
3863 rb
= rcu_dereference(event
->rb
);
3865 if (!atomic_inc_not_zero(&rb
->refcount
))
3873 static void ring_buffer_put(struct ring_buffer
*rb
)
3875 if (!atomic_dec_and_test(&rb
->refcount
))
3878 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
3880 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3883 static void perf_mmap_open(struct vm_area_struct
*vma
)
3885 struct perf_event
*event
= vma
->vm_file
->private_data
;
3887 atomic_inc(&event
->mmap_count
);
3888 atomic_inc(&event
->rb
->mmap_count
);
3892 * A buffer can be mmap()ed multiple times; either directly through the same
3893 * event, or through other events by use of perf_event_set_output().
3895 * In order to undo the VM accounting done by perf_mmap() we need to destroy
3896 * the buffer here, where we still have a VM context. This means we need
3897 * to detach all events redirecting to us.
3899 static void perf_mmap_close(struct vm_area_struct
*vma
)
3901 struct perf_event
*event
= vma
->vm_file
->private_data
;
3903 struct ring_buffer
*rb
= event
->rb
;
3904 struct user_struct
*mmap_user
= rb
->mmap_user
;
3905 int mmap_locked
= rb
->mmap_locked
;
3906 unsigned long size
= perf_data_size(rb
);
3908 atomic_dec(&rb
->mmap_count
);
3910 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
3913 /* Detach current event from the buffer. */
3914 rcu_assign_pointer(event
->rb
, NULL
);
3915 ring_buffer_detach(event
, rb
);
3916 mutex_unlock(&event
->mmap_mutex
);
3918 /* If there's still other mmap()s of this buffer, we're done. */
3919 if (atomic_read(&rb
->mmap_count
)) {
3920 ring_buffer_put(rb
); /* can't be last */
3925 * No other mmap()s, detach from all other events that might redirect
3926 * into the now unreachable buffer. Somewhat complicated by the
3927 * fact that rb::event_lock otherwise nests inside mmap_mutex.
3931 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
3932 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
3934 * This event is en-route to free_event() which will
3935 * detach it and remove it from the list.
3941 mutex_lock(&event
->mmap_mutex
);
3943 * Check we didn't race with perf_event_set_output() which can
3944 * swizzle the rb from under us while we were waiting to
3945 * acquire mmap_mutex.
3947 * If we find a different rb; ignore this event, a next
3948 * iteration will no longer find it on the list. We have to
3949 * still restart the iteration to make sure we're not now
3950 * iterating the wrong list.
3952 if (event
->rb
== rb
) {
3953 rcu_assign_pointer(event
->rb
, NULL
);
3954 ring_buffer_detach(event
, rb
);
3955 ring_buffer_put(rb
); /* can't be last, we still have one */
3957 mutex_unlock(&event
->mmap_mutex
);
3961 * Restart the iteration; either we're on the wrong list or
3962 * destroyed its integrity by doing a deletion.
3969 * It could be there's still a few 0-ref events on the list; they'll
3970 * get cleaned up by free_event() -- they'll also still have their
3971 * ref on the rb and will free it whenever they are done with it.
3973 * Aside from that, this buffer is 'fully' detached and unmapped,
3974 * undo the VM accounting.
3977 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
3978 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
3979 free_uid(mmap_user
);
3981 ring_buffer_put(rb
); /* could be last */
3984 static const struct vm_operations_struct perf_mmap_vmops
= {
3985 .open
= perf_mmap_open
,
3986 .close
= perf_mmap_close
,
3987 .fault
= perf_mmap_fault
,
3988 .page_mkwrite
= perf_mmap_fault
,
3991 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3993 struct perf_event
*event
= file
->private_data
;
3994 unsigned long user_locked
, user_lock_limit
;
3995 struct user_struct
*user
= current_user();
3996 unsigned long locked
, lock_limit
;
3997 struct ring_buffer
*rb
;
3998 unsigned long vma_size
;
3999 unsigned long nr_pages
;
4000 long user_extra
, extra
;
4001 int ret
= 0, flags
= 0;
4004 * Don't allow mmap() of inherited per-task counters. This would
4005 * create a performance issue due to all children writing to the
4008 if (event
->cpu
== -1 && event
->attr
.inherit
)
4011 if (!(vma
->vm_flags
& VM_SHARED
))
4014 vma_size
= vma
->vm_end
- vma
->vm_start
;
4015 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4018 * If we have rb pages ensure they're a power-of-two number, so we
4019 * can do bitmasks instead of modulo.
4021 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4024 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4027 if (vma
->vm_pgoff
!= 0)
4030 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4032 mutex_lock(&event
->mmap_mutex
);
4034 if (event
->rb
->nr_pages
!= nr_pages
) {
4039 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4041 * Raced against perf_mmap_close() through
4042 * perf_event_set_output(). Try again, hope for better
4045 mutex_unlock(&event
->mmap_mutex
);
4052 user_extra
= nr_pages
+ 1;
4053 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4056 * Increase the limit linearly with more CPUs:
4058 user_lock_limit
*= num_online_cpus();
4060 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4063 if (user_locked
> user_lock_limit
)
4064 extra
= user_locked
- user_lock_limit
;
4066 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4067 lock_limit
>>= PAGE_SHIFT
;
4068 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4070 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4071 !capable(CAP_IPC_LOCK
)) {
4078 if (vma
->vm_flags
& VM_WRITE
)
4079 flags
|= RING_BUFFER_WRITABLE
;
4081 rb
= rb_alloc(nr_pages
,
4082 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4090 atomic_set(&rb
->mmap_count
, 1);
4091 rb
->mmap_locked
= extra
;
4092 rb
->mmap_user
= get_current_user();
4094 atomic_long_add(user_extra
, &user
->locked_vm
);
4095 vma
->vm_mm
->pinned_vm
+= extra
;
4097 ring_buffer_attach(event
, rb
);
4098 rcu_assign_pointer(event
->rb
, rb
);
4100 perf_event_init_userpage(event
);
4101 perf_event_update_userpage(event
);
4105 atomic_inc(&event
->mmap_count
);
4106 mutex_unlock(&event
->mmap_mutex
);
4109 * Since pinned accounting is per vm we cannot allow fork() to copy our
4112 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4113 vma
->vm_ops
= &perf_mmap_vmops
;
4118 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4120 struct inode
*inode
= file_inode(filp
);
4121 struct perf_event
*event
= filp
->private_data
;
4124 mutex_lock(&inode
->i_mutex
);
4125 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4126 mutex_unlock(&inode
->i_mutex
);
4134 static const struct file_operations perf_fops
= {
4135 .llseek
= no_llseek
,
4136 .release
= perf_release
,
4139 .unlocked_ioctl
= perf_ioctl
,
4140 .compat_ioctl
= perf_ioctl
,
4142 .fasync
= perf_fasync
,
4148 * If there's data, ensure we set the poll() state and publish everything
4149 * to user-space before waking everybody up.
4152 void perf_event_wakeup(struct perf_event
*event
)
4154 ring_buffer_wakeup(event
);
4156 if (event
->pending_kill
) {
4157 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
4158 event
->pending_kill
= 0;
4162 static void perf_pending_event(struct irq_work
*entry
)
4164 struct perf_event
*event
= container_of(entry
,
4165 struct perf_event
, pending
);
4167 if (event
->pending_disable
) {
4168 event
->pending_disable
= 0;
4169 __perf_event_disable(event
);
4172 if (event
->pending_wakeup
) {
4173 event
->pending_wakeup
= 0;
4174 perf_event_wakeup(event
);
4179 * We assume there is only KVM supporting the callbacks.
4180 * Later on, we might change it to a list if there is
4181 * another virtualization implementation supporting the callbacks.
4183 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4185 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4187 perf_guest_cbs
= cbs
;
4190 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4192 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4194 perf_guest_cbs
= NULL
;
4197 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4200 perf_output_sample_regs(struct perf_output_handle
*handle
,
4201 struct pt_regs
*regs
, u64 mask
)
4205 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4206 sizeof(mask
) * BITS_PER_BYTE
) {
4209 val
= perf_reg_value(regs
, bit
);
4210 perf_output_put(handle
, val
);
4214 static void perf_sample_regs_user(struct perf_regs_user
*regs_user
,
4215 struct pt_regs
*regs
)
4217 if (!user_mode(regs
)) {
4219 regs
= task_pt_regs(current
);
4225 regs_user
->regs
= regs
;
4226 regs_user
->abi
= perf_reg_abi(current
);
4231 * Get remaining task size from user stack pointer.
4233 * It'd be better to take stack vma map and limit this more
4234 * precisly, but there's no way to get it safely under interrupt,
4235 * so using TASK_SIZE as limit.
4237 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
4239 unsigned long addr
= perf_user_stack_pointer(regs
);
4241 if (!addr
|| addr
>= TASK_SIZE
)
4244 return TASK_SIZE
- addr
;
4248 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
4249 struct pt_regs
*regs
)
4253 /* No regs, no stack pointer, no dump. */
4258 * Check if we fit in with the requested stack size into the:
4260 * If we don't, we limit the size to the TASK_SIZE.
4262 * - remaining sample size
4263 * If we don't, we customize the stack size to
4264 * fit in to the remaining sample size.
4267 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
4268 stack_size
= min(stack_size
, (u16
) task_size
);
4270 /* Current header size plus static size and dynamic size. */
4271 header_size
+= 2 * sizeof(u64
);
4273 /* Do we fit in with the current stack dump size? */
4274 if ((u16
) (header_size
+ stack_size
) < header_size
) {
4276 * If we overflow the maximum size for the sample,
4277 * we customize the stack dump size to fit in.
4279 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
4280 stack_size
= round_up(stack_size
, sizeof(u64
));
4287 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
4288 struct pt_regs
*regs
)
4290 /* Case of a kernel thread, nothing to dump */
4293 perf_output_put(handle
, size
);
4302 * - the size requested by user or the best one we can fit
4303 * in to the sample max size
4305 * - user stack dump data
4307 * - the actual dumped size
4311 perf_output_put(handle
, dump_size
);
4314 sp
= perf_user_stack_pointer(regs
);
4315 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
4316 dyn_size
= dump_size
- rem
;
4318 perf_output_skip(handle
, rem
);
4321 perf_output_put(handle
, dyn_size
);
4325 static void __perf_event_header__init_id(struct perf_event_header
*header
,
4326 struct perf_sample_data
*data
,
4327 struct perf_event
*event
)
4329 u64 sample_type
= event
->attr
.sample_type
;
4331 data
->type
= sample_type
;
4332 header
->size
+= event
->id_header_size
;
4334 if (sample_type
& PERF_SAMPLE_TID
) {
4335 /* namespace issues */
4336 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
4337 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
4340 if (sample_type
& PERF_SAMPLE_TIME
)
4341 data
->time
= perf_clock();
4343 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
4344 data
->id
= primary_event_id(event
);
4346 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4347 data
->stream_id
= event
->id
;
4349 if (sample_type
& PERF_SAMPLE_CPU
) {
4350 data
->cpu_entry
.cpu
= raw_smp_processor_id();
4351 data
->cpu_entry
.reserved
= 0;
4355 void perf_event_header__init_id(struct perf_event_header
*header
,
4356 struct perf_sample_data
*data
,
4357 struct perf_event
*event
)
4359 if (event
->attr
.sample_id_all
)
4360 __perf_event_header__init_id(header
, data
, event
);
4363 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
4364 struct perf_sample_data
*data
)
4366 u64 sample_type
= data
->type
;
4368 if (sample_type
& PERF_SAMPLE_TID
)
4369 perf_output_put(handle
, data
->tid_entry
);
4371 if (sample_type
& PERF_SAMPLE_TIME
)
4372 perf_output_put(handle
, data
->time
);
4374 if (sample_type
& PERF_SAMPLE_ID
)
4375 perf_output_put(handle
, data
->id
);
4377 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4378 perf_output_put(handle
, data
->stream_id
);
4380 if (sample_type
& PERF_SAMPLE_CPU
)
4381 perf_output_put(handle
, data
->cpu_entry
);
4383 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
4384 perf_output_put(handle
, data
->id
);
4387 void perf_event__output_id_sample(struct perf_event
*event
,
4388 struct perf_output_handle
*handle
,
4389 struct perf_sample_data
*sample
)
4391 if (event
->attr
.sample_id_all
)
4392 __perf_event__output_id_sample(handle
, sample
);
4395 static void perf_output_read_one(struct perf_output_handle
*handle
,
4396 struct perf_event
*event
,
4397 u64 enabled
, u64 running
)
4399 u64 read_format
= event
->attr
.read_format
;
4403 values
[n
++] = perf_event_count(event
);
4404 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4405 values
[n
++] = enabled
+
4406 atomic64_read(&event
->child_total_time_enabled
);
4408 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4409 values
[n
++] = running
+
4410 atomic64_read(&event
->child_total_time_running
);
4412 if (read_format
& PERF_FORMAT_ID
)
4413 values
[n
++] = primary_event_id(event
);
4415 __output_copy(handle
, values
, n
* sizeof(u64
));
4419 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
4421 static void perf_output_read_group(struct perf_output_handle
*handle
,
4422 struct perf_event
*event
,
4423 u64 enabled
, u64 running
)
4425 struct perf_event
*leader
= event
->group_leader
, *sub
;
4426 u64 read_format
= event
->attr
.read_format
;
4430 values
[n
++] = 1 + leader
->nr_siblings
;
4432 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4433 values
[n
++] = enabled
;
4435 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4436 values
[n
++] = running
;
4438 if (leader
!= event
)
4439 leader
->pmu
->read(leader
);
4441 values
[n
++] = perf_event_count(leader
);
4442 if (read_format
& PERF_FORMAT_ID
)
4443 values
[n
++] = primary_event_id(leader
);
4445 __output_copy(handle
, values
, n
* sizeof(u64
));
4447 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4450 if ((sub
!= event
) &&
4451 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
4452 sub
->pmu
->read(sub
);
4454 values
[n
++] = perf_event_count(sub
);
4455 if (read_format
& PERF_FORMAT_ID
)
4456 values
[n
++] = primary_event_id(sub
);
4458 __output_copy(handle
, values
, n
* sizeof(u64
));
4462 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
4463 PERF_FORMAT_TOTAL_TIME_RUNNING)
4465 static void perf_output_read(struct perf_output_handle
*handle
,
4466 struct perf_event
*event
)
4468 u64 enabled
= 0, running
= 0, now
;
4469 u64 read_format
= event
->attr
.read_format
;
4472 * compute total_time_enabled, total_time_running
4473 * based on snapshot values taken when the event
4474 * was last scheduled in.
4476 * we cannot simply called update_context_time()
4477 * because of locking issue as we are called in
4480 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
4481 calc_timer_values(event
, &now
, &enabled
, &running
);
4483 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
4484 perf_output_read_group(handle
, event
, enabled
, running
);
4486 perf_output_read_one(handle
, event
, enabled
, running
);
4489 void perf_output_sample(struct perf_output_handle
*handle
,
4490 struct perf_event_header
*header
,
4491 struct perf_sample_data
*data
,
4492 struct perf_event
*event
)
4494 u64 sample_type
= data
->type
;
4496 perf_output_put(handle
, *header
);
4498 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
4499 perf_output_put(handle
, data
->id
);
4501 if (sample_type
& PERF_SAMPLE_IP
)
4502 perf_output_put(handle
, data
->ip
);
4504 if (sample_type
& PERF_SAMPLE_TID
)
4505 perf_output_put(handle
, data
->tid_entry
);
4507 if (sample_type
& PERF_SAMPLE_TIME
)
4508 perf_output_put(handle
, data
->time
);
4510 if (sample_type
& PERF_SAMPLE_ADDR
)
4511 perf_output_put(handle
, data
->addr
);
4513 if (sample_type
& PERF_SAMPLE_ID
)
4514 perf_output_put(handle
, data
->id
);
4516 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4517 perf_output_put(handle
, data
->stream_id
);
4519 if (sample_type
& PERF_SAMPLE_CPU
)
4520 perf_output_put(handle
, data
->cpu_entry
);
4522 if (sample_type
& PERF_SAMPLE_PERIOD
)
4523 perf_output_put(handle
, data
->period
);
4525 if (sample_type
& PERF_SAMPLE_READ
)
4526 perf_output_read(handle
, event
);
4528 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4529 if (data
->callchain
) {
4532 if (data
->callchain
)
4533 size
+= data
->callchain
->nr
;
4535 size
*= sizeof(u64
);
4537 __output_copy(handle
, data
->callchain
, size
);
4540 perf_output_put(handle
, nr
);
4544 if (sample_type
& PERF_SAMPLE_RAW
) {
4546 perf_output_put(handle
, data
->raw
->size
);
4547 __output_copy(handle
, data
->raw
->data
,
4554 .size
= sizeof(u32
),
4557 perf_output_put(handle
, raw
);
4561 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4562 if (data
->br_stack
) {
4565 size
= data
->br_stack
->nr
4566 * sizeof(struct perf_branch_entry
);
4568 perf_output_put(handle
, data
->br_stack
->nr
);
4569 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
4572 * we always store at least the value of nr
4575 perf_output_put(handle
, nr
);
4579 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4580 u64 abi
= data
->regs_user
.abi
;
4583 * If there are no regs to dump, notice it through
4584 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
4586 perf_output_put(handle
, abi
);
4589 u64 mask
= event
->attr
.sample_regs_user
;
4590 perf_output_sample_regs(handle
,
4591 data
->regs_user
.regs
,
4596 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
4597 perf_output_sample_ustack(handle
,
4598 data
->stack_user_size
,
4599 data
->regs_user
.regs
);
4602 if (sample_type
& PERF_SAMPLE_WEIGHT
)
4603 perf_output_put(handle
, data
->weight
);
4605 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
4606 perf_output_put(handle
, data
->data_src
.val
);
4608 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
4609 perf_output_put(handle
, data
->txn
);
4611 if (!event
->attr
.watermark
) {
4612 int wakeup_events
= event
->attr
.wakeup_events
;
4614 if (wakeup_events
) {
4615 struct ring_buffer
*rb
= handle
->rb
;
4616 int events
= local_inc_return(&rb
->events
);
4618 if (events
>= wakeup_events
) {
4619 local_sub(wakeup_events
, &rb
->events
);
4620 local_inc(&rb
->wakeup
);
4626 void perf_prepare_sample(struct perf_event_header
*header
,
4627 struct perf_sample_data
*data
,
4628 struct perf_event
*event
,
4629 struct pt_regs
*regs
)
4631 u64 sample_type
= event
->attr
.sample_type
;
4633 header
->type
= PERF_RECORD_SAMPLE
;
4634 header
->size
= sizeof(*header
) + event
->header_size
;
4637 header
->misc
|= perf_misc_flags(regs
);
4639 __perf_event_header__init_id(header
, data
, event
);
4641 if (sample_type
& PERF_SAMPLE_IP
)
4642 data
->ip
= perf_instruction_pointer(regs
);
4644 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4647 data
->callchain
= perf_callchain(event
, regs
);
4649 if (data
->callchain
)
4650 size
+= data
->callchain
->nr
;
4652 header
->size
+= size
* sizeof(u64
);
4655 if (sample_type
& PERF_SAMPLE_RAW
) {
4656 int size
= sizeof(u32
);
4659 size
+= data
->raw
->size
;
4661 size
+= sizeof(u32
);
4663 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4664 header
->size
+= size
;
4667 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4668 int size
= sizeof(u64
); /* nr */
4669 if (data
->br_stack
) {
4670 size
+= data
->br_stack
->nr
4671 * sizeof(struct perf_branch_entry
);
4673 header
->size
+= size
;
4676 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4677 /* regs dump ABI info */
4678 int size
= sizeof(u64
);
4680 perf_sample_regs_user(&data
->regs_user
, regs
);
4682 if (data
->regs_user
.regs
) {
4683 u64 mask
= event
->attr
.sample_regs_user
;
4684 size
+= hweight64(mask
) * sizeof(u64
);
4687 header
->size
+= size
;
4690 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
4692 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
4693 * processed as the last one or have additional check added
4694 * in case new sample type is added, because we could eat
4695 * up the rest of the sample size.
4697 struct perf_regs_user
*uregs
= &data
->regs_user
;
4698 u16 stack_size
= event
->attr
.sample_stack_user
;
4699 u16 size
= sizeof(u64
);
4702 perf_sample_regs_user(uregs
, regs
);
4704 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
4708 * If there is something to dump, add space for the dump
4709 * itself and for the field that tells the dynamic size,
4710 * which is how many have been actually dumped.
4713 size
+= sizeof(u64
) + stack_size
;
4715 data
->stack_user_size
= stack_size
;
4716 header
->size
+= size
;
4720 static void perf_event_output(struct perf_event
*event
,
4721 struct perf_sample_data
*data
,
4722 struct pt_regs
*regs
)
4724 struct perf_output_handle handle
;
4725 struct perf_event_header header
;
4727 /* protect the callchain buffers */
4730 perf_prepare_sample(&header
, data
, event
, regs
);
4732 if (perf_output_begin(&handle
, event
, header
.size
))
4735 perf_output_sample(&handle
, &header
, data
, event
);
4737 perf_output_end(&handle
);
4747 struct perf_read_event
{
4748 struct perf_event_header header
;
4755 perf_event_read_event(struct perf_event
*event
,
4756 struct task_struct
*task
)
4758 struct perf_output_handle handle
;
4759 struct perf_sample_data sample
;
4760 struct perf_read_event read_event
= {
4762 .type
= PERF_RECORD_READ
,
4764 .size
= sizeof(read_event
) + event
->read_size
,
4766 .pid
= perf_event_pid(event
, task
),
4767 .tid
= perf_event_tid(event
, task
),
4771 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4772 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
4776 perf_output_put(&handle
, read_event
);
4777 perf_output_read(&handle
, event
);
4778 perf_event__output_id_sample(event
, &handle
, &sample
);
4780 perf_output_end(&handle
);
4783 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
4786 perf_event_aux_ctx(struct perf_event_context
*ctx
,
4787 perf_event_aux_output_cb output
,
4790 struct perf_event
*event
;
4792 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4793 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4795 if (!event_filter_match(event
))
4797 output(event
, data
);
4802 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
4803 struct perf_event_context
*task_ctx
)
4805 struct perf_cpu_context
*cpuctx
;
4806 struct perf_event_context
*ctx
;
4811 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4812 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4813 if (cpuctx
->unique_pmu
!= pmu
)
4815 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
4818 ctxn
= pmu
->task_ctx_nr
;
4821 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4823 perf_event_aux_ctx(ctx
, output
, data
);
4825 put_cpu_ptr(pmu
->pmu_cpu_context
);
4830 perf_event_aux_ctx(task_ctx
, output
, data
);
4837 * task tracking -- fork/exit
4839 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
4842 struct perf_task_event
{
4843 struct task_struct
*task
;
4844 struct perf_event_context
*task_ctx
;
4847 struct perf_event_header header
;
4857 static int perf_event_task_match(struct perf_event
*event
)
4859 return event
->attr
.comm
|| event
->attr
.mmap
||
4860 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
4864 static void perf_event_task_output(struct perf_event
*event
,
4867 struct perf_task_event
*task_event
= data
;
4868 struct perf_output_handle handle
;
4869 struct perf_sample_data sample
;
4870 struct task_struct
*task
= task_event
->task
;
4871 int ret
, size
= task_event
->event_id
.header
.size
;
4873 if (!perf_event_task_match(event
))
4876 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4878 ret
= perf_output_begin(&handle
, event
,
4879 task_event
->event_id
.header
.size
);
4883 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4884 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4886 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4887 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4889 perf_output_put(&handle
, task_event
->event_id
);
4891 perf_event__output_id_sample(event
, &handle
, &sample
);
4893 perf_output_end(&handle
);
4895 task_event
->event_id
.header
.size
= size
;
4898 static void perf_event_task(struct task_struct
*task
,
4899 struct perf_event_context
*task_ctx
,
4902 struct perf_task_event task_event
;
4904 if (!atomic_read(&nr_comm_events
) &&
4905 !atomic_read(&nr_mmap_events
) &&
4906 !atomic_read(&nr_task_events
))
4909 task_event
= (struct perf_task_event
){
4911 .task_ctx
= task_ctx
,
4914 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4916 .size
= sizeof(task_event
.event_id
),
4922 .time
= perf_clock(),
4926 perf_event_aux(perf_event_task_output
,
4931 void perf_event_fork(struct task_struct
*task
)
4933 perf_event_task(task
, NULL
, 1);
4940 struct perf_comm_event
{
4941 struct task_struct
*task
;
4946 struct perf_event_header header
;
4953 static int perf_event_comm_match(struct perf_event
*event
)
4955 return event
->attr
.comm
;
4958 static void perf_event_comm_output(struct perf_event
*event
,
4961 struct perf_comm_event
*comm_event
= data
;
4962 struct perf_output_handle handle
;
4963 struct perf_sample_data sample
;
4964 int size
= comm_event
->event_id
.header
.size
;
4967 if (!perf_event_comm_match(event
))
4970 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4971 ret
= perf_output_begin(&handle
, event
,
4972 comm_event
->event_id
.header
.size
);
4977 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4978 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4980 perf_output_put(&handle
, comm_event
->event_id
);
4981 __output_copy(&handle
, comm_event
->comm
,
4982 comm_event
->comm_size
);
4984 perf_event__output_id_sample(event
, &handle
, &sample
);
4986 perf_output_end(&handle
);
4988 comm_event
->event_id
.header
.size
= size
;
4991 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4993 char comm
[TASK_COMM_LEN
];
4996 memset(comm
, 0, sizeof(comm
));
4997 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4998 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5000 comm_event
->comm
= comm
;
5001 comm_event
->comm_size
= size
;
5003 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5005 perf_event_aux(perf_event_comm_output
,
5010 void perf_event_comm(struct task_struct
*task
)
5012 struct perf_comm_event comm_event
;
5013 struct perf_event_context
*ctx
;
5017 for_each_task_context_nr(ctxn
) {
5018 ctx
= task
->perf_event_ctxp
[ctxn
];
5022 perf_event_enable_on_exec(ctx
);
5026 if (!atomic_read(&nr_comm_events
))
5029 comm_event
= (struct perf_comm_event
){
5035 .type
= PERF_RECORD_COMM
,
5044 perf_event_comm_event(&comm_event
);
5051 struct perf_mmap_event
{
5052 struct vm_area_struct
*vma
;
5054 const char *file_name
;
5061 struct perf_event_header header
;
5071 static int perf_event_mmap_match(struct perf_event
*event
,
5074 struct perf_mmap_event
*mmap_event
= data
;
5075 struct vm_area_struct
*vma
= mmap_event
->vma
;
5076 int executable
= vma
->vm_flags
& VM_EXEC
;
5078 return (!executable
&& event
->attr
.mmap_data
) ||
5079 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5082 static void perf_event_mmap_output(struct perf_event
*event
,
5085 struct perf_mmap_event
*mmap_event
= data
;
5086 struct perf_output_handle handle
;
5087 struct perf_sample_data sample
;
5088 int size
= mmap_event
->event_id
.header
.size
;
5091 if (!perf_event_mmap_match(event
, data
))
5094 if (event
->attr
.mmap2
) {
5095 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5096 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5097 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5098 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5099 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5102 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5103 ret
= perf_output_begin(&handle
, event
,
5104 mmap_event
->event_id
.header
.size
);
5108 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5109 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5111 perf_output_put(&handle
, mmap_event
->event_id
);
5113 if (event
->attr
.mmap2
) {
5114 perf_output_put(&handle
, mmap_event
->maj
);
5115 perf_output_put(&handle
, mmap_event
->min
);
5116 perf_output_put(&handle
, mmap_event
->ino
);
5117 perf_output_put(&handle
, mmap_event
->ino_generation
);
5120 __output_copy(&handle
, mmap_event
->file_name
,
5121 mmap_event
->file_size
);
5123 perf_event__output_id_sample(event
, &handle
, &sample
);
5125 perf_output_end(&handle
);
5127 mmap_event
->event_id
.header
.size
= size
;
5130 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5132 struct vm_area_struct
*vma
= mmap_event
->vma
;
5133 struct file
*file
= vma
->vm_file
;
5134 int maj
= 0, min
= 0;
5135 u64 ino
= 0, gen
= 0;
5142 struct inode
*inode
;
5145 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5147 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
5151 * d_path() works from the end of the rb backwards, so we
5152 * need to add enough zero bytes after the string to handle
5153 * the 64bit alignment we do later.
5155 name
= d_path(&file
->f_path
, buf
, PATH_MAX
- sizeof(u64
));
5157 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
5160 inode
= file_inode(vma
->vm_file
);
5161 dev
= inode
->i_sb
->s_dev
;
5163 gen
= inode
->i_generation
;
5168 name
= (char *)arch_vma_name(vma
);
5170 name
= strncpy(tmp
, name
, sizeof(tmp
) - 1);
5171 tmp
[sizeof(tmp
) - 1] = '\0';
5175 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
5176 vma
->vm_end
>= vma
->vm_mm
->brk
) {
5177 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
5180 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
5181 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
5182 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
5186 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
5192 * Since our buffer works in 8 byte units we need to align our string
5193 * size to a multiple of 8. However, we must guarantee the tail end is
5194 * zero'd out to avoid leaking random bits to userspace.
5196 size
= strlen(name
)+1;
5197 while (!IS_ALIGNED(size
, sizeof(u64
)))
5198 name
[size
++] = '\0';
5200 mmap_event
->file_name
= name
;
5201 mmap_event
->file_size
= size
;
5202 mmap_event
->maj
= maj
;
5203 mmap_event
->min
= min
;
5204 mmap_event
->ino
= ino
;
5205 mmap_event
->ino_generation
= gen
;
5207 if (!(vma
->vm_flags
& VM_EXEC
))
5208 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
5210 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
5212 perf_event_aux(perf_event_mmap_output
,
5219 void perf_event_mmap(struct vm_area_struct
*vma
)
5221 struct perf_mmap_event mmap_event
;
5223 if (!atomic_read(&nr_mmap_events
))
5226 mmap_event
= (struct perf_mmap_event
){
5232 .type
= PERF_RECORD_MMAP
,
5233 .misc
= PERF_RECORD_MISC_USER
,
5238 .start
= vma
->vm_start
,
5239 .len
= vma
->vm_end
- vma
->vm_start
,
5240 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
5242 /* .maj (attr_mmap2 only) */
5243 /* .min (attr_mmap2 only) */
5244 /* .ino (attr_mmap2 only) */
5245 /* .ino_generation (attr_mmap2 only) */
5248 perf_event_mmap_event(&mmap_event
);
5252 * IRQ throttle logging
5255 static void perf_log_throttle(struct perf_event
*event
, int enable
)
5257 struct perf_output_handle handle
;
5258 struct perf_sample_data sample
;
5262 struct perf_event_header header
;
5266 } throttle_event
= {
5268 .type
= PERF_RECORD_THROTTLE
,
5270 .size
= sizeof(throttle_event
),
5272 .time
= perf_clock(),
5273 .id
= primary_event_id(event
),
5274 .stream_id
= event
->id
,
5278 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
5280 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
5282 ret
= perf_output_begin(&handle
, event
,
5283 throttle_event
.header
.size
);
5287 perf_output_put(&handle
, throttle_event
);
5288 perf_event__output_id_sample(event
, &handle
, &sample
);
5289 perf_output_end(&handle
);
5293 * Generic event overflow handling, sampling.
5296 static int __perf_event_overflow(struct perf_event
*event
,
5297 int throttle
, struct perf_sample_data
*data
,
5298 struct pt_regs
*regs
)
5300 int events
= atomic_read(&event
->event_limit
);
5301 struct hw_perf_event
*hwc
= &event
->hw
;
5306 * Non-sampling counters might still use the PMI to fold short
5307 * hardware counters, ignore those.
5309 if (unlikely(!is_sampling_event(event
)))
5312 seq
= __this_cpu_read(perf_throttled_seq
);
5313 if (seq
!= hwc
->interrupts_seq
) {
5314 hwc
->interrupts_seq
= seq
;
5315 hwc
->interrupts
= 1;
5318 if (unlikely(throttle
5319 && hwc
->interrupts
>= max_samples_per_tick
)) {
5320 __this_cpu_inc(perf_throttled_count
);
5321 hwc
->interrupts
= MAX_INTERRUPTS
;
5322 perf_log_throttle(event
, 0);
5323 tick_nohz_full_kick();
5328 if (event
->attr
.freq
) {
5329 u64 now
= perf_clock();
5330 s64 delta
= now
- hwc
->freq_time_stamp
;
5332 hwc
->freq_time_stamp
= now
;
5334 if (delta
> 0 && delta
< 2*TICK_NSEC
)
5335 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
5339 * XXX event_limit might not quite work as expected on inherited
5343 event
->pending_kill
= POLL_IN
;
5344 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
5346 event
->pending_kill
= POLL_HUP
;
5347 event
->pending_disable
= 1;
5348 irq_work_queue(&event
->pending
);
5351 if (event
->overflow_handler
)
5352 event
->overflow_handler(event
, data
, regs
);
5354 perf_event_output(event
, data
, regs
);
5356 if (event
->fasync
&& event
->pending_kill
) {
5357 event
->pending_wakeup
= 1;
5358 irq_work_queue(&event
->pending
);
5364 int perf_event_overflow(struct perf_event
*event
,
5365 struct perf_sample_data
*data
,
5366 struct pt_regs
*regs
)
5368 return __perf_event_overflow(event
, 1, data
, regs
);
5372 * Generic software event infrastructure
5375 struct swevent_htable
{
5376 struct swevent_hlist
*swevent_hlist
;
5377 struct mutex hlist_mutex
;
5380 /* Recursion avoidance in each contexts */
5381 int recursion
[PERF_NR_CONTEXTS
];
5384 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
5387 * We directly increment event->count and keep a second value in
5388 * event->hw.period_left to count intervals. This period event
5389 * is kept in the range [-sample_period, 0] so that we can use the
5393 u64
perf_swevent_set_period(struct perf_event
*event
)
5395 struct hw_perf_event
*hwc
= &event
->hw
;
5396 u64 period
= hwc
->last_period
;
5400 hwc
->last_period
= hwc
->sample_period
;
5403 old
= val
= local64_read(&hwc
->period_left
);
5407 nr
= div64_u64(period
+ val
, period
);
5408 offset
= nr
* period
;
5410 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
5416 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
5417 struct perf_sample_data
*data
,
5418 struct pt_regs
*regs
)
5420 struct hw_perf_event
*hwc
= &event
->hw
;
5424 overflow
= perf_swevent_set_period(event
);
5426 if (hwc
->interrupts
== MAX_INTERRUPTS
)
5429 for (; overflow
; overflow
--) {
5430 if (__perf_event_overflow(event
, throttle
,
5433 * We inhibit the overflow from happening when
5434 * hwc->interrupts == MAX_INTERRUPTS.
5442 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
5443 struct perf_sample_data
*data
,
5444 struct pt_regs
*regs
)
5446 struct hw_perf_event
*hwc
= &event
->hw
;
5448 local64_add(nr
, &event
->count
);
5453 if (!is_sampling_event(event
))
5456 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
5458 return perf_swevent_overflow(event
, 1, data
, regs
);
5460 data
->period
= event
->hw
.last_period
;
5462 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
5463 return perf_swevent_overflow(event
, 1, data
, regs
);
5465 if (local64_add_negative(nr
, &hwc
->period_left
))
5468 perf_swevent_overflow(event
, 0, data
, regs
);
5471 static int perf_exclude_event(struct perf_event
*event
,
5472 struct pt_regs
*regs
)
5474 if (event
->hw
.state
& PERF_HES_STOPPED
)
5478 if (event
->attr
.exclude_user
&& user_mode(regs
))
5481 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
5488 static int perf_swevent_match(struct perf_event
*event
,
5489 enum perf_type_id type
,
5491 struct perf_sample_data
*data
,
5492 struct pt_regs
*regs
)
5494 if (event
->attr
.type
!= type
)
5497 if (event
->attr
.config
!= event_id
)
5500 if (perf_exclude_event(event
, regs
))
5506 static inline u64
swevent_hash(u64 type
, u32 event_id
)
5508 u64 val
= event_id
| (type
<< 32);
5510 return hash_64(val
, SWEVENT_HLIST_BITS
);
5513 static inline struct hlist_head
*
5514 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
5516 u64 hash
= swevent_hash(type
, event_id
);
5518 return &hlist
->heads
[hash
];
5521 /* For the read side: events when they trigger */
5522 static inline struct hlist_head
*
5523 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
5525 struct swevent_hlist
*hlist
;
5527 hlist
= rcu_dereference(swhash
->swevent_hlist
);
5531 return __find_swevent_head(hlist
, type
, event_id
);
5534 /* For the event head insertion and removal in the hlist */
5535 static inline struct hlist_head
*
5536 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
5538 struct swevent_hlist
*hlist
;
5539 u32 event_id
= event
->attr
.config
;
5540 u64 type
= event
->attr
.type
;
5543 * Event scheduling is always serialized against hlist allocation
5544 * and release. Which makes the protected version suitable here.
5545 * The context lock guarantees that.
5547 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
5548 lockdep_is_held(&event
->ctx
->lock
));
5552 return __find_swevent_head(hlist
, type
, event_id
);
5555 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
5557 struct perf_sample_data
*data
,
5558 struct pt_regs
*regs
)
5560 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5561 struct perf_event
*event
;
5562 struct hlist_head
*head
;
5565 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
5569 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5570 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
5571 perf_swevent_event(event
, nr
, data
, regs
);
5577 int perf_swevent_get_recursion_context(void)
5579 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5581 return get_recursion_context(swhash
->recursion
);
5583 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
5585 inline void perf_swevent_put_recursion_context(int rctx
)
5587 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5589 put_recursion_context(swhash
->recursion
, rctx
);
5592 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
5594 struct perf_sample_data data
;
5597 preempt_disable_notrace();
5598 rctx
= perf_swevent_get_recursion_context();
5602 perf_sample_data_init(&data
, addr
, 0);
5604 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
5606 perf_swevent_put_recursion_context(rctx
);
5607 preempt_enable_notrace();
5610 static void perf_swevent_read(struct perf_event
*event
)
5614 static int perf_swevent_add(struct perf_event
*event
, int flags
)
5616 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5617 struct hw_perf_event
*hwc
= &event
->hw
;
5618 struct hlist_head
*head
;
5620 if (is_sampling_event(event
)) {
5621 hwc
->last_period
= hwc
->sample_period
;
5622 perf_swevent_set_period(event
);
5625 hwc
->state
= !(flags
& PERF_EF_START
);
5627 head
= find_swevent_head(swhash
, event
);
5628 if (WARN_ON_ONCE(!head
))
5631 hlist_add_head_rcu(&event
->hlist_entry
, head
);
5636 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5638 hlist_del_rcu(&event
->hlist_entry
);
5641 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5643 event
->hw
.state
= 0;
5646 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5648 event
->hw
.state
= PERF_HES_STOPPED
;
5651 /* Deref the hlist from the update side */
5652 static inline struct swevent_hlist
*
5653 swevent_hlist_deref(struct swevent_htable
*swhash
)
5655 return rcu_dereference_protected(swhash
->swevent_hlist
,
5656 lockdep_is_held(&swhash
->hlist_mutex
));
5659 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5661 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5666 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5667 kfree_rcu(hlist
, rcu_head
);
5670 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5672 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5674 mutex_lock(&swhash
->hlist_mutex
);
5676 if (!--swhash
->hlist_refcount
)
5677 swevent_hlist_release(swhash
);
5679 mutex_unlock(&swhash
->hlist_mutex
);
5682 static void swevent_hlist_put(struct perf_event
*event
)
5686 if (event
->cpu
!= -1) {
5687 swevent_hlist_put_cpu(event
, event
->cpu
);
5691 for_each_possible_cpu(cpu
)
5692 swevent_hlist_put_cpu(event
, cpu
);
5695 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5697 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5700 mutex_lock(&swhash
->hlist_mutex
);
5702 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5703 struct swevent_hlist
*hlist
;
5705 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5710 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5712 swhash
->hlist_refcount
++;
5714 mutex_unlock(&swhash
->hlist_mutex
);
5719 static int swevent_hlist_get(struct perf_event
*event
)
5722 int cpu
, failed_cpu
;
5724 if (event
->cpu
!= -1)
5725 return swevent_hlist_get_cpu(event
, event
->cpu
);
5728 for_each_possible_cpu(cpu
) {
5729 err
= swevent_hlist_get_cpu(event
, cpu
);
5739 for_each_possible_cpu(cpu
) {
5740 if (cpu
== failed_cpu
)
5742 swevent_hlist_put_cpu(event
, cpu
);
5749 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5751 static void sw_perf_event_destroy(struct perf_event
*event
)
5753 u64 event_id
= event
->attr
.config
;
5755 WARN_ON(event
->parent
);
5757 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
5758 swevent_hlist_put(event
);
5761 static int perf_swevent_init(struct perf_event
*event
)
5763 u64 event_id
= event
->attr
.config
;
5765 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5769 * no branch sampling for software events
5771 if (has_branch_stack(event
))
5775 case PERF_COUNT_SW_CPU_CLOCK
:
5776 case PERF_COUNT_SW_TASK_CLOCK
:
5783 if (event_id
>= PERF_COUNT_SW_MAX
)
5786 if (!event
->parent
) {
5789 err
= swevent_hlist_get(event
);
5793 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
5794 event
->destroy
= sw_perf_event_destroy
;
5800 static int perf_swevent_event_idx(struct perf_event
*event
)
5805 static struct pmu perf_swevent
= {
5806 .task_ctx_nr
= perf_sw_context
,
5808 .event_init
= perf_swevent_init
,
5809 .add
= perf_swevent_add
,
5810 .del
= perf_swevent_del
,
5811 .start
= perf_swevent_start
,
5812 .stop
= perf_swevent_stop
,
5813 .read
= perf_swevent_read
,
5815 .event_idx
= perf_swevent_event_idx
,
5818 #ifdef CONFIG_EVENT_TRACING
5820 static int perf_tp_filter_match(struct perf_event
*event
,
5821 struct perf_sample_data
*data
)
5823 void *record
= data
->raw
->data
;
5825 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5830 static int perf_tp_event_match(struct perf_event
*event
,
5831 struct perf_sample_data
*data
,
5832 struct pt_regs
*regs
)
5834 if (event
->hw
.state
& PERF_HES_STOPPED
)
5837 * All tracepoints are from kernel-space.
5839 if (event
->attr
.exclude_kernel
)
5842 if (!perf_tp_filter_match(event
, data
))
5848 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5849 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
5850 struct task_struct
*task
)
5852 struct perf_sample_data data
;
5853 struct perf_event
*event
;
5855 struct perf_raw_record raw
= {
5860 perf_sample_data_init(&data
, addr
, 0);
5863 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5864 if (perf_tp_event_match(event
, &data
, regs
))
5865 perf_swevent_event(event
, count
, &data
, regs
);
5869 * If we got specified a target task, also iterate its context and
5870 * deliver this event there too.
5872 if (task
&& task
!= current
) {
5873 struct perf_event_context
*ctx
;
5874 struct trace_entry
*entry
= record
;
5877 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
5881 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5882 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5884 if (event
->attr
.config
!= entry
->type
)
5886 if (perf_tp_event_match(event
, &data
, regs
))
5887 perf_swevent_event(event
, count
, &data
, regs
);
5893 perf_swevent_put_recursion_context(rctx
);
5895 EXPORT_SYMBOL_GPL(perf_tp_event
);
5897 static void tp_perf_event_destroy(struct perf_event
*event
)
5899 perf_trace_destroy(event
);
5902 static int perf_tp_event_init(struct perf_event
*event
)
5906 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5910 * no branch sampling for tracepoint events
5912 if (has_branch_stack(event
))
5915 err
= perf_trace_init(event
);
5919 event
->destroy
= tp_perf_event_destroy
;
5924 static struct pmu perf_tracepoint
= {
5925 .task_ctx_nr
= perf_sw_context
,
5927 .event_init
= perf_tp_event_init
,
5928 .add
= perf_trace_add
,
5929 .del
= perf_trace_del
,
5930 .start
= perf_swevent_start
,
5931 .stop
= perf_swevent_stop
,
5932 .read
= perf_swevent_read
,
5934 .event_idx
= perf_swevent_event_idx
,
5937 static inline void perf_tp_register(void)
5939 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5942 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5947 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5950 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5951 if (IS_ERR(filter_str
))
5952 return PTR_ERR(filter_str
);
5954 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5960 static void perf_event_free_filter(struct perf_event
*event
)
5962 ftrace_profile_free_filter(event
);
5967 static inline void perf_tp_register(void)
5971 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5976 static void perf_event_free_filter(struct perf_event
*event
)
5980 #endif /* CONFIG_EVENT_TRACING */
5982 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5983 void perf_bp_event(struct perf_event
*bp
, void *data
)
5985 struct perf_sample_data sample
;
5986 struct pt_regs
*regs
= data
;
5988 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
5990 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5991 perf_swevent_event(bp
, 1, &sample
, regs
);
5996 * hrtimer based swevent callback
5999 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
6001 enum hrtimer_restart ret
= HRTIMER_RESTART
;
6002 struct perf_sample_data data
;
6003 struct pt_regs
*regs
;
6004 struct perf_event
*event
;
6007 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
6009 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
6010 return HRTIMER_NORESTART
;
6012 event
->pmu
->read(event
);
6014 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
6015 regs
= get_irq_regs();
6017 if (regs
&& !perf_exclude_event(event
, regs
)) {
6018 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
6019 if (__perf_event_overflow(event
, 1, &data
, regs
))
6020 ret
= HRTIMER_NORESTART
;
6023 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
6024 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
6029 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
6031 struct hw_perf_event
*hwc
= &event
->hw
;
6034 if (!is_sampling_event(event
))
6037 period
= local64_read(&hwc
->period_left
);
6042 local64_set(&hwc
->period_left
, 0);
6044 period
= max_t(u64
, 10000, hwc
->sample_period
);
6046 __hrtimer_start_range_ns(&hwc
->hrtimer
,
6047 ns_to_ktime(period
), 0,
6048 HRTIMER_MODE_REL_PINNED
, 0);
6051 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
6053 struct hw_perf_event
*hwc
= &event
->hw
;
6055 if (is_sampling_event(event
)) {
6056 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
6057 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
6059 hrtimer_cancel(&hwc
->hrtimer
);
6063 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
6065 struct hw_perf_event
*hwc
= &event
->hw
;
6067 if (!is_sampling_event(event
))
6070 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
6071 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
6074 * Since hrtimers have a fixed rate, we can do a static freq->period
6075 * mapping and avoid the whole period adjust feedback stuff.
6077 if (event
->attr
.freq
) {
6078 long freq
= event
->attr
.sample_freq
;
6080 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
6081 hwc
->sample_period
= event
->attr
.sample_period
;
6082 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6083 hwc
->last_period
= hwc
->sample_period
;
6084 event
->attr
.freq
= 0;
6089 * Software event: cpu wall time clock
6092 static void cpu_clock_event_update(struct perf_event
*event
)
6097 now
= local_clock();
6098 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
6099 local64_add(now
- prev
, &event
->count
);
6102 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
6104 local64_set(&event
->hw
.prev_count
, local_clock());
6105 perf_swevent_start_hrtimer(event
);
6108 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
6110 perf_swevent_cancel_hrtimer(event
);
6111 cpu_clock_event_update(event
);
6114 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
6116 if (flags
& PERF_EF_START
)
6117 cpu_clock_event_start(event
, flags
);
6122 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
6124 cpu_clock_event_stop(event
, flags
);
6127 static void cpu_clock_event_read(struct perf_event
*event
)
6129 cpu_clock_event_update(event
);
6132 static int cpu_clock_event_init(struct perf_event
*event
)
6134 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6137 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
6141 * no branch sampling for software events
6143 if (has_branch_stack(event
))
6146 perf_swevent_init_hrtimer(event
);
6151 static struct pmu perf_cpu_clock
= {
6152 .task_ctx_nr
= perf_sw_context
,
6154 .event_init
= cpu_clock_event_init
,
6155 .add
= cpu_clock_event_add
,
6156 .del
= cpu_clock_event_del
,
6157 .start
= cpu_clock_event_start
,
6158 .stop
= cpu_clock_event_stop
,
6159 .read
= cpu_clock_event_read
,
6161 .event_idx
= perf_swevent_event_idx
,
6165 * Software event: task time clock
6168 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
6173 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
6175 local64_add(delta
, &event
->count
);
6178 static void task_clock_event_start(struct perf_event
*event
, int flags
)
6180 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
6181 perf_swevent_start_hrtimer(event
);
6184 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
6186 perf_swevent_cancel_hrtimer(event
);
6187 task_clock_event_update(event
, event
->ctx
->time
);
6190 static int task_clock_event_add(struct perf_event
*event
, int flags
)
6192 if (flags
& PERF_EF_START
)
6193 task_clock_event_start(event
, flags
);
6198 static void task_clock_event_del(struct perf_event
*event
, int flags
)
6200 task_clock_event_stop(event
, PERF_EF_UPDATE
);
6203 static void task_clock_event_read(struct perf_event
*event
)
6205 u64 now
= perf_clock();
6206 u64 delta
= now
- event
->ctx
->timestamp
;
6207 u64 time
= event
->ctx
->time
+ delta
;
6209 task_clock_event_update(event
, time
);
6212 static int task_clock_event_init(struct perf_event
*event
)
6214 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6217 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
6221 * no branch sampling for software events
6223 if (has_branch_stack(event
))
6226 perf_swevent_init_hrtimer(event
);
6231 static struct pmu perf_task_clock
= {
6232 .task_ctx_nr
= perf_sw_context
,
6234 .event_init
= task_clock_event_init
,
6235 .add
= task_clock_event_add
,
6236 .del
= task_clock_event_del
,
6237 .start
= task_clock_event_start
,
6238 .stop
= task_clock_event_stop
,
6239 .read
= task_clock_event_read
,
6241 .event_idx
= perf_swevent_event_idx
,
6244 static void perf_pmu_nop_void(struct pmu
*pmu
)
6248 static int perf_pmu_nop_int(struct pmu
*pmu
)
6253 static void perf_pmu_start_txn(struct pmu
*pmu
)
6255 perf_pmu_disable(pmu
);
6258 static int perf_pmu_commit_txn(struct pmu
*pmu
)
6260 perf_pmu_enable(pmu
);
6264 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
6266 perf_pmu_enable(pmu
);
6269 static int perf_event_idx_default(struct perf_event
*event
)
6271 return event
->hw
.idx
+ 1;
6275 * Ensures all contexts with the same task_ctx_nr have the same
6276 * pmu_cpu_context too.
6278 static void *find_pmu_context(int ctxn
)
6285 list_for_each_entry(pmu
, &pmus
, entry
) {
6286 if (pmu
->task_ctx_nr
== ctxn
)
6287 return pmu
->pmu_cpu_context
;
6293 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
6297 for_each_possible_cpu(cpu
) {
6298 struct perf_cpu_context
*cpuctx
;
6300 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6302 if (cpuctx
->unique_pmu
== old_pmu
)
6303 cpuctx
->unique_pmu
= pmu
;
6307 static void free_pmu_context(struct pmu
*pmu
)
6311 mutex_lock(&pmus_lock
);
6313 * Like a real lame refcount.
6315 list_for_each_entry(i
, &pmus
, entry
) {
6316 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
6317 update_pmu_context(i
, pmu
);
6322 free_percpu(pmu
->pmu_cpu_context
);
6324 mutex_unlock(&pmus_lock
);
6326 static struct idr pmu_idr
;
6329 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
6331 struct pmu
*pmu
= dev_get_drvdata(dev
);
6333 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
6337 perf_event_mux_interval_ms_show(struct device
*dev
,
6338 struct device_attribute
*attr
,
6341 struct pmu
*pmu
= dev_get_drvdata(dev
);
6343 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
6347 perf_event_mux_interval_ms_store(struct device
*dev
,
6348 struct device_attribute
*attr
,
6349 const char *buf
, size_t count
)
6351 struct pmu
*pmu
= dev_get_drvdata(dev
);
6352 int timer
, cpu
, ret
;
6354 ret
= kstrtoint(buf
, 0, &timer
);
6361 /* same value, noting to do */
6362 if (timer
== pmu
->hrtimer_interval_ms
)
6365 pmu
->hrtimer_interval_ms
= timer
;
6367 /* update all cpuctx for this PMU */
6368 for_each_possible_cpu(cpu
) {
6369 struct perf_cpu_context
*cpuctx
;
6370 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6371 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
6373 if (hrtimer_active(&cpuctx
->hrtimer
))
6374 hrtimer_forward_now(&cpuctx
->hrtimer
, cpuctx
->hrtimer_interval
);
6380 static struct device_attribute pmu_dev_attrs
[] = {
6382 __ATTR_RW(perf_event_mux_interval_ms
),
6386 static int pmu_bus_running
;
6387 static struct bus_type pmu_bus
= {
6388 .name
= "event_source",
6389 .dev_attrs
= pmu_dev_attrs
,
6392 static void pmu_dev_release(struct device
*dev
)
6397 static int pmu_dev_alloc(struct pmu
*pmu
)
6401 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
6405 pmu
->dev
->groups
= pmu
->attr_groups
;
6406 device_initialize(pmu
->dev
);
6407 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
6411 dev_set_drvdata(pmu
->dev
, pmu
);
6412 pmu
->dev
->bus
= &pmu_bus
;
6413 pmu
->dev
->release
= pmu_dev_release
;
6414 ret
= device_add(pmu
->dev
);
6422 put_device(pmu
->dev
);
6426 static struct lock_class_key cpuctx_mutex
;
6427 static struct lock_class_key cpuctx_lock
;
6429 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
6433 mutex_lock(&pmus_lock
);
6435 pmu
->pmu_disable_count
= alloc_percpu(int);
6436 if (!pmu
->pmu_disable_count
)
6445 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
6453 if (pmu_bus_running
) {
6454 ret
= pmu_dev_alloc(pmu
);
6460 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
6461 if (pmu
->pmu_cpu_context
)
6462 goto got_cpu_context
;
6465 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
6466 if (!pmu
->pmu_cpu_context
)
6469 for_each_possible_cpu(cpu
) {
6470 struct perf_cpu_context
*cpuctx
;
6472 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6473 __perf_event_init_context(&cpuctx
->ctx
);
6474 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
6475 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
6476 cpuctx
->ctx
.type
= cpu_context
;
6477 cpuctx
->ctx
.pmu
= pmu
;
6479 __perf_cpu_hrtimer_init(cpuctx
, cpu
);
6481 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
6482 cpuctx
->unique_pmu
= pmu
;
6486 if (!pmu
->start_txn
) {
6487 if (pmu
->pmu_enable
) {
6489 * If we have pmu_enable/pmu_disable calls, install
6490 * transaction stubs that use that to try and batch
6491 * hardware accesses.
6493 pmu
->start_txn
= perf_pmu_start_txn
;
6494 pmu
->commit_txn
= perf_pmu_commit_txn
;
6495 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
6497 pmu
->start_txn
= perf_pmu_nop_void
;
6498 pmu
->commit_txn
= perf_pmu_nop_int
;
6499 pmu
->cancel_txn
= perf_pmu_nop_void
;
6503 if (!pmu
->pmu_enable
) {
6504 pmu
->pmu_enable
= perf_pmu_nop_void
;
6505 pmu
->pmu_disable
= perf_pmu_nop_void
;
6508 if (!pmu
->event_idx
)
6509 pmu
->event_idx
= perf_event_idx_default
;
6511 list_add_rcu(&pmu
->entry
, &pmus
);
6514 mutex_unlock(&pmus_lock
);
6519 device_del(pmu
->dev
);
6520 put_device(pmu
->dev
);
6523 if (pmu
->type
>= PERF_TYPE_MAX
)
6524 idr_remove(&pmu_idr
, pmu
->type
);
6527 free_percpu(pmu
->pmu_disable_count
);
6531 void perf_pmu_unregister(struct pmu
*pmu
)
6533 mutex_lock(&pmus_lock
);
6534 list_del_rcu(&pmu
->entry
);
6535 mutex_unlock(&pmus_lock
);
6538 * We dereference the pmu list under both SRCU and regular RCU, so
6539 * synchronize against both of those.
6541 synchronize_srcu(&pmus_srcu
);
6544 free_percpu(pmu
->pmu_disable_count
);
6545 if (pmu
->type
>= PERF_TYPE_MAX
)
6546 idr_remove(&pmu_idr
, pmu
->type
);
6547 device_del(pmu
->dev
);
6548 put_device(pmu
->dev
);
6549 free_pmu_context(pmu
);
6552 struct pmu
*perf_init_event(struct perf_event
*event
)
6554 struct pmu
*pmu
= NULL
;
6558 idx
= srcu_read_lock(&pmus_srcu
);
6561 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
6565 ret
= pmu
->event_init(event
);
6571 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6573 ret
= pmu
->event_init(event
);
6577 if (ret
!= -ENOENT
) {
6582 pmu
= ERR_PTR(-ENOENT
);
6584 srcu_read_unlock(&pmus_srcu
, idx
);
6589 static void account_event_cpu(struct perf_event
*event
, int cpu
)
6594 if (has_branch_stack(event
)) {
6595 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
6596 atomic_inc(&per_cpu(perf_branch_stack_events
, cpu
));
6598 if (is_cgroup_event(event
))
6599 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
6602 static void account_event(struct perf_event
*event
)
6607 if (event
->attach_state
& PERF_ATTACH_TASK
)
6608 static_key_slow_inc(&perf_sched_events
.key
);
6609 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
6610 atomic_inc(&nr_mmap_events
);
6611 if (event
->attr
.comm
)
6612 atomic_inc(&nr_comm_events
);
6613 if (event
->attr
.task
)
6614 atomic_inc(&nr_task_events
);
6615 if (event
->attr
.freq
) {
6616 if (atomic_inc_return(&nr_freq_events
) == 1)
6617 tick_nohz_full_kick_all();
6619 if (has_branch_stack(event
))
6620 static_key_slow_inc(&perf_sched_events
.key
);
6621 if (is_cgroup_event(event
))
6622 static_key_slow_inc(&perf_sched_events
.key
);
6624 account_event_cpu(event
, event
->cpu
);
6628 * Allocate and initialize a event structure
6630 static struct perf_event
*
6631 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
6632 struct task_struct
*task
,
6633 struct perf_event
*group_leader
,
6634 struct perf_event
*parent_event
,
6635 perf_overflow_handler_t overflow_handler
,
6639 struct perf_event
*event
;
6640 struct hw_perf_event
*hwc
;
6643 if ((unsigned)cpu
>= nr_cpu_ids
) {
6644 if (!task
|| cpu
!= -1)
6645 return ERR_PTR(-EINVAL
);
6648 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
6650 return ERR_PTR(-ENOMEM
);
6653 * Single events are their own group leaders, with an
6654 * empty sibling list:
6657 group_leader
= event
;
6659 mutex_init(&event
->child_mutex
);
6660 INIT_LIST_HEAD(&event
->child_list
);
6662 INIT_LIST_HEAD(&event
->group_entry
);
6663 INIT_LIST_HEAD(&event
->event_entry
);
6664 INIT_LIST_HEAD(&event
->sibling_list
);
6665 INIT_LIST_HEAD(&event
->rb_entry
);
6667 init_waitqueue_head(&event
->waitq
);
6668 init_irq_work(&event
->pending
, perf_pending_event
);
6670 mutex_init(&event
->mmap_mutex
);
6672 atomic_long_set(&event
->refcount
, 1);
6674 event
->attr
= *attr
;
6675 event
->group_leader
= group_leader
;
6679 event
->parent
= parent_event
;
6681 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
6682 event
->id
= atomic64_inc_return(&perf_event_id
);
6684 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6687 event
->attach_state
= PERF_ATTACH_TASK
;
6689 if (attr
->type
== PERF_TYPE_TRACEPOINT
)
6690 event
->hw
.tp_target
= task
;
6691 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6693 * hw_breakpoint is a bit difficult here..
6695 else if (attr
->type
== PERF_TYPE_BREAKPOINT
)
6696 event
->hw
.bp_target
= task
;
6700 if (!overflow_handler
&& parent_event
) {
6701 overflow_handler
= parent_event
->overflow_handler
;
6702 context
= parent_event
->overflow_handler_context
;
6705 event
->overflow_handler
= overflow_handler
;
6706 event
->overflow_handler_context
= context
;
6708 perf_event__state_init(event
);
6713 hwc
->sample_period
= attr
->sample_period
;
6714 if (attr
->freq
&& attr
->sample_freq
)
6715 hwc
->sample_period
= 1;
6716 hwc
->last_period
= hwc
->sample_period
;
6718 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6721 * we currently do not support PERF_FORMAT_GROUP on inherited events
6723 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
6726 pmu
= perf_init_event(event
);
6729 else if (IS_ERR(pmu
)) {
6734 if (!event
->parent
) {
6735 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6736 err
= get_callchain_buffers();
6746 event
->destroy(event
);
6749 put_pid_ns(event
->ns
);
6752 return ERR_PTR(err
);
6755 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6756 struct perf_event_attr
*attr
)
6761 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6765 * zero the full structure, so that a short copy will be nice.
6767 memset(attr
, 0, sizeof(*attr
));
6769 ret
= get_user(size
, &uattr
->size
);
6773 if (size
> PAGE_SIZE
) /* silly large */
6776 if (!size
) /* abi compat */
6777 size
= PERF_ATTR_SIZE_VER0
;
6779 if (size
< PERF_ATTR_SIZE_VER0
)
6783 * If we're handed a bigger struct than we know of,
6784 * ensure all the unknown bits are 0 - i.e. new
6785 * user-space does not rely on any kernel feature
6786 * extensions we dont know about yet.
6788 if (size
> sizeof(*attr
)) {
6789 unsigned char __user
*addr
;
6790 unsigned char __user
*end
;
6793 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6794 end
= (void __user
*)uattr
+ size
;
6796 for (; addr
< end
; addr
++) {
6797 ret
= get_user(val
, addr
);
6803 size
= sizeof(*attr
);
6806 ret
= copy_from_user(attr
, uattr
, size
);
6810 /* disabled for now */
6814 if (attr
->__reserved_1
)
6817 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6820 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6823 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6824 u64 mask
= attr
->branch_sample_type
;
6826 /* only using defined bits */
6827 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
6830 /* at least one branch bit must be set */
6831 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
6834 /* propagate priv level, when not set for branch */
6835 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
6837 /* exclude_kernel checked on syscall entry */
6838 if (!attr
->exclude_kernel
)
6839 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
6841 if (!attr
->exclude_user
)
6842 mask
|= PERF_SAMPLE_BRANCH_USER
;
6844 if (!attr
->exclude_hv
)
6845 mask
|= PERF_SAMPLE_BRANCH_HV
;
6847 * adjust user setting (for HW filter setup)
6849 attr
->branch_sample_type
= mask
;
6851 /* privileged levels capture (kernel, hv): check permissions */
6852 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
6853 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6857 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
6858 ret
= perf_reg_validate(attr
->sample_regs_user
);
6863 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
6864 if (!arch_perf_have_user_stack_dump())
6868 * We have __u32 type for the size, but so far
6869 * we can only use __u16 as maximum due to the
6870 * __u16 sample size limit.
6872 if (attr
->sample_stack_user
>= USHRT_MAX
)
6874 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
6882 put_user(sizeof(*attr
), &uattr
->size
);
6888 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
6890 struct ring_buffer
*rb
= NULL
, *old_rb
= NULL
;
6896 /* don't allow circular references */
6897 if (event
== output_event
)
6901 * Don't allow cross-cpu buffers
6903 if (output_event
->cpu
!= event
->cpu
)
6907 * If its not a per-cpu rb, it must be the same task.
6909 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
6913 mutex_lock(&event
->mmap_mutex
);
6914 /* Can't redirect output if we've got an active mmap() */
6915 if (atomic_read(&event
->mmap_count
))
6921 /* get the rb we want to redirect to */
6922 rb
= ring_buffer_get(output_event
);
6928 ring_buffer_detach(event
, old_rb
);
6931 ring_buffer_attach(event
, rb
);
6933 rcu_assign_pointer(event
->rb
, rb
);
6936 ring_buffer_put(old_rb
);
6938 * Since we detached before setting the new rb, so that we
6939 * could attach the new rb, we could have missed a wakeup.
6942 wake_up_all(&event
->waitq
);
6947 mutex_unlock(&event
->mmap_mutex
);
6954 * sys_perf_event_open - open a performance event, associate it to a task/cpu
6956 * @attr_uptr: event_id type attributes for monitoring/sampling
6959 * @group_fd: group leader event fd
6961 SYSCALL_DEFINE5(perf_event_open
,
6962 struct perf_event_attr __user
*, attr_uptr
,
6963 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
6965 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
6966 struct perf_event
*event
, *sibling
;
6967 struct perf_event_attr attr
;
6968 struct perf_event_context
*ctx
;
6969 struct file
*event_file
= NULL
;
6970 struct fd group
= {NULL
, 0};
6971 struct task_struct
*task
= NULL
;
6977 /* for future expandability... */
6978 if (flags
& ~PERF_FLAG_ALL
)
6981 err
= perf_copy_attr(attr_uptr
, &attr
);
6985 if (!attr
.exclude_kernel
) {
6986 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6991 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
6996 * In cgroup mode, the pid argument is used to pass the fd
6997 * opened to the cgroup directory in cgroupfs. The cpu argument
6998 * designates the cpu on which to monitor threads from that
7001 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
7004 event_fd
= get_unused_fd();
7008 if (group_fd
!= -1) {
7009 err
= perf_fget_light(group_fd
, &group
);
7012 group_leader
= group
.file
->private_data
;
7013 if (flags
& PERF_FLAG_FD_OUTPUT
)
7014 output_event
= group_leader
;
7015 if (flags
& PERF_FLAG_FD_NO_GROUP
)
7016 group_leader
= NULL
;
7019 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
7020 task
= find_lively_task_by_vpid(pid
);
7022 err
= PTR_ERR(task
);
7029 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
7031 if (IS_ERR(event
)) {
7032 err
= PTR_ERR(event
);
7036 if (flags
& PERF_FLAG_PID_CGROUP
) {
7037 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
7039 __free_event(event
);
7044 account_event(event
);
7047 * Special case software events and allow them to be part of
7048 * any hardware group.
7053 (is_software_event(event
) != is_software_event(group_leader
))) {
7054 if (is_software_event(event
)) {
7056 * If event and group_leader are not both a software
7057 * event, and event is, then group leader is not.
7059 * Allow the addition of software events to !software
7060 * groups, this is safe because software events never
7063 pmu
= group_leader
->pmu
;
7064 } else if (is_software_event(group_leader
) &&
7065 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
7067 * In case the group is a pure software group, and we
7068 * try to add a hardware event, move the whole group to
7069 * the hardware context.
7076 * Get the target context (task or percpu):
7078 ctx
= find_get_context(pmu
, task
, event
->cpu
);
7085 put_task_struct(task
);
7090 * Look up the group leader (we will attach this event to it):
7096 * Do not allow a recursive hierarchy (this new sibling
7097 * becoming part of another group-sibling):
7099 if (group_leader
->group_leader
!= group_leader
)
7102 * Do not allow to attach to a group in a different
7103 * task or CPU context:
7106 if (group_leader
->ctx
->type
!= ctx
->type
)
7109 if (group_leader
->ctx
!= ctx
)
7114 * Only a group leader can be exclusive or pinned
7116 if (attr
.exclusive
|| attr
.pinned
)
7121 err
= perf_event_set_output(event
, output_event
);
7126 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
7127 if (IS_ERR(event_file
)) {
7128 err
= PTR_ERR(event_file
);
7133 struct perf_event_context
*gctx
= group_leader
->ctx
;
7135 mutex_lock(&gctx
->mutex
);
7136 perf_remove_from_context(group_leader
);
7139 * Removing from the context ends up with disabled
7140 * event. What we want here is event in the initial
7141 * startup state, ready to be add into new context.
7143 perf_event__state_init(group_leader
);
7144 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
7146 perf_remove_from_context(sibling
);
7147 perf_event__state_init(sibling
);
7150 mutex_unlock(&gctx
->mutex
);
7154 WARN_ON_ONCE(ctx
->parent_ctx
);
7155 mutex_lock(&ctx
->mutex
);
7159 perf_install_in_context(ctx
, group_leader
, event
->cpu
);
7161 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
7163 perf_install_in_context(ctx
, sibling
, event
->cpu
);
7168 perf_install_in_context(ctx
, event
, event
->cpu
);
7169 perf_unpin_context(ctx
);
7170 mutex_unlock(&ctx
->mutex
);
7174 event
->owner
= current
;
7176 mutex_lock(¤t
->perf_event_mutex
);
7177 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
7178 mutex_unlock(¤t
->perf_event_mutex
);
7181 * Precalculate sample_data sizes
7183 perf_event__header_size(event
);
7184 perf_event__id_header_size(event
);
7187 * Drop the reference on the group_event after placing the
7188 * new event on the sibling_list. This ensures destruction
7189 * of the group leader will find the pointer to itself in
7190 * perf_group_detach().
7193 fd_install(event_fd
, event_file
);
7197 perf_unpin_context(ctx
);
7204 put_task_struct(task
);
7208 put_unused_fd(event_fd
);
7213 * perf_event_create_kernel_counter
7215 * @attr: attributes of the counter to create
7216 * @cpu: cpu in which the counter is bound
7217 * @task: task to profile (NULL for percpu)
7220 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
7221 struct task_struct
*task
,
7222 perf_overflow_handler_t overflow_handler
,
7225 struct perf_event_context
*ctx
;
7226 struct perf_event
*event
;
7230 * Get the target context (task or percpu):
7233 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
7234 overflow_handler
, context
);
7235 if (IS_ERR(event
)) {
7236 err
= PTR_ERR(event
);
7240 account_event(event
);
7242 ctx
= find_get_context(event
->pmu
, task
, cpu
);
7248 WARN_ON_ONCE(ctx
->parent_ctx
);
7249 mutex_lock(&ctx
->mutex
);
7250 perf_install_in_context(ctx
, event
, cpu
);
7251 perf_unpin_context(ctx
);
7252 mutex_unlock(&ctx
->mutex
);
7259 return ERR_PTR(err
);
7261 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
7263 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
7265 struct perf_event_context
*src_ctx
;
7266 struct perf_event_context
*dst_ctx
;
7267 struct perf_event
*event
, *tmp
;
7270 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
7271 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
7273 mutex_lock(&src_ctx
->mutex
);
7274 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
7276 perf_remove_from_context(event
);
7277 unaccount_event_cpu(event
, src_cpu
);
7279 list_add(&event
->migrate_entry
, &events
);
7281 mutex_unlock(&src_ctx
->mutex
);
7285 mutex_lock(&dst_ctx
->mutex
);
7286 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
7287 list_del(&event
->migrate_entry
);
7288 if (event
->state
>= PERF_EVENT_STATE_OFF
)
7289 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7290 account_event_cpu(event
, dst_cpu
);
7291 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
7294 mutex_unlock(&dst_ctx
->mutex
);
7296 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
7298 static void sync_child_event(struct perf_event
*child_event
,
7299 struct task_struct
*child
)
7301 struct perf_event
*parent_event
= child_event
->parent
;
7304 if (child_event
->attr
.inherit_stat
)
7305 perf_event_read_event(child_event
, child
);
7307 child_val
= perf_event_count(child_event
);
7310 * Add back the child's count to the parent's count:
7312 atomic64_add(child_val
, &parent_event
->child_count
);
7313 atomic64_add(child_event
->total_time_enabled
,
7314 &parent_event
->child_total_time_enabled
);
7315 atomic64_add(child_event
->total_time_running
,
7316 &parent_event
->child_total_time_running
);
7319 * Remove this event from the parent's list
7321 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7322 mutex_lock(&parent_event
->child_mutex
);
7323 list_del_init(&child_event
->child_list
);
7324 mutex_unlock(&parent_event
->child_mutex
);
7327 * Release the parent event, if this was the last
7330 put_event(parent_event
);
7334 __perf_event_exit_task(struct perf_event
*child_event
,
7335 struct perf_event_context
*child_ctx
,
7336 struct task_struct
*child
)
7338 if (child_event
->parent
) {
7339 raw_spin_lock_irq(&child_ctx
->lock
);
7340 perf_group_detach(child_event
);
7341 raw_spin_unlock_irq(&child_ctx
->lock
);
7344 perf_remove_from_context(child_event
);
7347 * It can happen that the parent exits first, and has events
7348 * that are still around due to the child reference. These
7349 * events need to be zapped.
7351 if (child_event
->parent
) {
7352 sync_child_event(child_event
, child
);
7353 free_event(child_event
);
7357 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
7359 struct perf_event
*child_event
, *tmp
;
7360 struct perf_event_context
*child_ctx
;
7361 unsigned long flags
;
7363 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
7364 perf_event_task(child
, NULL
, 0);
7368 local_irq_save(flags
);
7370 * We can't reschedule here because interrupts are disabled,
7371 * and either child is current or it is a task that can't be
7372 * scheduled, so we are now safe from rescheduling changing
7375 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
7378 * Take the context lock here so that if find_get_context is
7379 * reading child->perf_event_ctxp, we wait until it has
7380 * incremented the context's refcount before we do put_ctx below.
7382 raw_spin_lock(&child_ctx
->lock
);
7383 task_ctx_sched_out(child_ctx
);
7384 child
->perf_event_ctxp
[ctxn
] = NULL
;
7386 * If this context is a clone; unclone it so it can't get
7387 * swapped to another process while we're removing all
7388 * the events from it.
7390 unclone_ctx(child_ctx
);
7391 update_context_time(child_ctx
);
7392 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
7395 * Report the task dead after unscheduling the events so that we
7396 * won't get any samples after PERF_RECORD_EXIT. We can however still
7397 * get a few PERF_RECORD_READ events.
7399 perf_event_task(child
, child_ctx
, 0);
7402 * We can recurse on the same lock type through:
7404 * __perf_event_exit_task()
7405 * sync_child_event()
7407 * mutex_lock(&ctx->mutex)
7409 * But since its the parent context it won't be the same instance.
7411 mutex_lock(&child_ctx
->mutex
);
7414 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
7416 __perf_event_exit_task(child_event
, child_ctx
, child
);
7418 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
7420 __perf_event_exit_task(child_event
, child_ctx
, child
);
7423 * If the last event was a group event, it will have appended all
7424 * its siblings to the list, but we obtained 'tmp' before that which
7425 * will still point to the list head terminating the iteration.
7427 if (!list_empty(&child_ctx
->pinned_groups
) ||
7428 !list_empty(&child_ctx
->flexible_groups
))
7431 mutex_unlock(&child_ctx
->mutex
);
7437 * When a child task exits, feed back event values to parent events.
7439 void perf_event_exit_task(struct task_struct
*child
)
7441 struct perf_event
*event
, *tmp
;
7444 mutex_lock(&child
->perf_event_mutex
);
7445 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
7447 list_del_init(&event
->owner_entry
);
7450 * Ensure the list deletion is visible before we clear
7451 * the owner, closes a race against perf_release() where
7452 * we need to serialize on the owner->perf_event_mutex.
7455 event
->owner
= NULL
;
7457 mutex_unlock(&child
->perf_event_mutex
);
7459 for_each_task_context_nr(ctxn
)
7460 perf_event_exit_task_context(child
, ctxn
);
7463 static void perf_free_event(struct perf_event
*event
,
7464 struct perf_event_context
*ctx
)
7466 struct perf_event
*parent
= event
->parent
;
7468 if (WARN_ON_ONCE(!parent
))
7471 mutex_lock(&parent
->child_mutex
);
7472 list_del_init(&event
->child_list
);
7473 mutex_unlock(&parent
->child_mutex
);
7477 perf_group_detach(event
);
7478 list_del_event(event
, ctx
);
7483 * free an unexposed, unused context as created by inheritance by
7484 * perf_event_init_task below, used by fork() in case of fail.
7486 void perf_event_free_task(struct task_struct
*task
)
7488 struct perf_event_context
*ctx
;
7489 struct perf_event
*event
, *tmp
;
7492 for_each_task_context_nr(ctxn
) {
7493 ctx
= task
->perf_event_ctxp
[ctxn
];
7497 mutex_lock(&ctx
->mutex
);
7499 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
7501 perf_free_event(event
, ctx
);
7503 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
7505 perf_free_event(event
, ctx
);
7507 if (!list_empty(&ctx
->pinned_groups
) ||
7508 !list_empty(&ctx
->flexible_groups
))
7511 mutex_unlock(&ctx
->mutex
);
7517 void perf_event_delayed_put(struct task_struct
*task
)
7521 for_each_task_context_nr(ctxn
)
7522 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
7526 * inherit a event from parent task to child task:
7528 static struct perf_event
*
7529 inherit_event(struct perf_event
*parent_event
,
7530 struct task_struct
*parent
,
7531 struct perf_event_context
*parent_ctx
,
7532 struct task_struct
*child
,
7533 struct perf_event
*group_leader
,
7534 struct perf_event_context
*child_ctx
)
7536 struct perf_event
*child_event
;
7537 unsigned long flags
;
7540 * Instead of creating recursive hierarchies of events,
7541 * we link inherited events back to the original parent,
7542 * which has a filp for sure, which we use as the reference
7545 if (parent_event
->parent
)
7546 parent_event
= parent_event
->parent
;
7548 child_event
= perf_event_alloc(&parent_event
->attr
,
7551 group_leader
, parent_event
,
7553 if (IS_ERR(child_event
))
7556 if (!atomic_long_inc_not_zero(&parent_event
->refcount
)) {
7557 free_event(child_event
);
7564 * Make the child state follow the state of the parent event,
7565 * not its attr.disabled bit. We hold the parent's mutex,
7566 * so we won't race with perf_event_{en, dis}able_family.
7568 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
7569 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
7571 child_event
->state
= PERF_EVENT_STATE_OFF
;
7573 if (parent_event
->attr
.freq
) {
7574 u64 sample_period
= parent_event
->hw
.sample_period
;
7575 struct hw_perf_event
*hwc
= &child_event
->hw
;
7577 hwc
->sample_period
= sample_period
;
7578 hwc
->last_period
= sample_period
;
7580 local64_set(&hwc
->period_left
, sample_period
);
7583 child_event
->ctx
= child_ctx
;
7584 child_event
->overflow_handler
= parent_event
->overflow_handler
;
7585 child_event
->overflow_handler_context
7586 = parent_event
->overflow_handler_context
;
7589 * Precalculate sample_data sizes
7591 perf_event__header_size(child_event
);
7592 perf_event__id_header_size(child_event
);
7595 * Link it up in the child's context:
7597 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
7598 add_event_to_ctx(child_event
, child_ctx
);
7599 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
7602 * Link this into the parent event's child list
7604 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7605 mutex_lock(&parent_event
->child_mutex
);
7606 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
7607 mutex_unlock(&parent_event
->child_mutex
);
7612 static int inherit_group(struct perf_event
*parent_event
,
7613 struct task_struct
*parent
,
7614 struct perf_event_context
*parent_ctx
,
7615 struct task_struct
*child
,
7616 struct perf_event_context
*child_ctx
)
7618 struct perf_event
*leader
;
7619 struct perf_event
*sub
;
7620 struct perf_event
*child_ctr
;
7622 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
7623 child
, NULL
, child_ctx
);
7625 return PTR_ERR(leader
);
7626 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
7627 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
7628 child
, leader
, child_ctx
);
7629 if (IS_ERR(child_ctr
))
7630 return PTR_ERR(child_ctr
);
7636 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
7637 struct perf_event_context
*parent_ctx
,
7638 struct task_struct
*child
, int ctxn
,
7642 struct perf_event_context
*child_ctx
;
7644 if (!event
->attr
.inherit
) {
7649 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7652 * This is executed from the parent task context, so
7653 * inherit events that have been marked for cloning.
7654 * First allocate and initialize a context for the
7658 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
7662 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
7665 ret
= inherit_group(event
, parent
, parent_ctx
,
7675 * Initialize the perf_event context in task_struct
7677 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
7679 struct perf_event_context
*child_ctx
, *parent_ctx
;
7680 struct perf_event_context
*cloned_ctx
;
7681 struct perf_event
*event
;
7682 struct task_struct
*parent
= current
;
7683 int inherited_all
= 1;
7684 unsigned long flags
;
7687 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
7691 * If the parent's context is a clone, pin it so it won't get
7694 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
7697 * No need to check if parent_ctx != NULL here; since we saw
7698 * it non-NULL earlier, the only reason for it to become NULL
7699 * is if we exit, and since we're currently in the middle of
7700 * a fork we can't be exiting at the same time.
7704 * Lock the parent list. No need to lock the child - not PID
7705 * hashed yet and not running, so nobody can access it.
7707 mutex_lock(&parent_ctx
->mutex
);
7710 * We dont have to disable NMIs - we are only looking at
7711 * the list, not manipulating it:
7713 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
7714 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7715 child
, ctxn
, &inherited_all
);
7721 * We can't hold ctx->lock when iterating the ->flexible_group list due
7722 * to allocations, but we need to prevent rotation because
7723 * rotate_ctx() will change the list from interrupt context.
7725 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7726 parent_ctx
->rotate_disable
= 1;
7727 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7729 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
7730 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7731 child
, ctxn
, &inherited_all
);
7736 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7737 parent_ctx
->rotate_disable
= 0;
7739 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7741 if (child_ctx
&& inherited_all
) {
7743 * Mark the child context as a clone of the parent
7744 * context, or of whatever the parent is a clone of.
7746 * Note that if the parent is a clone, the holding of
7747 * parent_ctx->lock avoids it from being uncloned.
7749 cloned_ctx
= parent_ctx
->parent_ctx
;
7751 child_ctx
->parent_ctx
= cloned_ctx
;
7752 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
7754 child_ctx
->parent_ctx
= parent_ctx
;
7755 child_ctx
->parent_gen
= parent_ctx
->generation
;
7757 get_ctx(child_ctx
->parent_ctx
);
7760 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7761 mutex_unlock(&parent_ctx
->mutex
);
7763 perf_unpin_context(parent_ctx
);
7764 put_ctx(parent_ctx
);
7770 * Initialize the perf_event context in task_struct
7772 int perf_event_init_task(struct task_struct
*child
)
7776 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7777 mutex_init(&child
->perf_event_mutex
);
7778 INIT_LIST_HEAD(&child
->perf_event_list
);
7780 for_each_task_context_nr(ctxn
) {
7781 ret
= perf_event_init_context(child
, ctxn
);
7789 static void __init
perf_event_init_all_cpus(void)
7791 struct swevent_htable
*swhash
;
7794 for_each_possible_cpu(cpu
) {
7795 swhash
= &per_cpu(swevent_htable
, cpu
);
7796 mutex_init(&swhash
->hlist_mutex
);
7797 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7801 static void perf_event_init_cpu(int cpu
)
7803 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7805 mutex_lock(&swhash
->hlist_mutex
);
7806 if (swhash
->hlist_refcount
> 0) {
7807 struct swevent_hlist
*hlist
;
7809 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7811 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7813 mutex_unlock(&swhash
->hlist_mutex
);
7816 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7817 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7819 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7821 WARN_ON(!irqs_disabled());
7823 list_del_init(&cpuctx
->rotation_list
);
7826 static void __perf_event_exit_context(void *__info
)
7828 struct perf_event_context
*ctx
= __info
;
7829 struct perf_event
*event
, *tmp
;
7831 perf_pmu_rotate_stop(ctx
->pmu
);
7833 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
7834 __perf_remove_from_context(event
);
7835 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
7836 __perf_remove_from_context(event
);
7839 static void perf_event_exit_cpu_context(int cpu
)
7841 struct perf_event_context
*ctx
;
7845 idx
= srcu_read_lock(&pmus_srcu
);
7846 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7847 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
7849 mutex_lock(&ctx
->mutex
);
7850 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
7851 mutex_unlock(&ctx
->mutex
);
7853 srcu_read_unlock(&pmus_srcu
, idx
);
7856 static void perf_event_exit_cpu(int cpu
)
7858 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7860 mutex_lock(&swhash
->hlist_mutex
);
7861 swevent_hlist_release(swhash
);
7862 mutex_unlock(&swhash
->hlist_mutex
);
7864 perf_event_exit_cpu_context(cpu
);
7867 static inline void perf_event_exit_cpu(int cpu
) { }
7871 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
7875 for_each_online_cpu(cpu
)
7876 perf_event_exit_cpu(cpu
);
7882 * Run the perf reboot notifier at the very last possible moment so that
7883 * the generic watchdog code runs as long as possible.
7885 static struct notifier_block perf_reboot_notifier
= {
7886 .notifier_call
= perf_reboot
,
7887 .priority
= INT_MIN
,
7891 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
7893 unsigned int cpu
= (long)hcpu
;
7895 switch (action
& ~CPU_TASKS_FROZEN
) {
7897 case CPU_UP_PREPARE
:
7898 case CPU_DOWN_FAILED
:
7899 perf_event_init_cpu(cpu
);
7902 case CPU_UP_CANCELED
:
7903 case CPU_DOWN_PREPARE
:
7904 perf_event_exit_cpu(cpu
);
7913 void __init
perf_event_init(void)
7919 perf_event_init_all_cpus();
7920 init_srcu_struct(&pmus_srcu
);
7921 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
7922 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
7923 perf_pmu_register(&perf_task_clock
, NULL
, -1);
7925 perf_cpu_notifier(perf_cpu_notify
);
7926 register_reboot_notifier(&perf_reboot_notifier
);
7928 ret
= init_hw_breakpoint();
7929 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
7931 /* do not patch jump label more than once per second */
7932 jump_label_rate_limit(&perf_sched_events
, HZ
);
7935 * Build time assertion that we keep the data_head at the intended
7936 * location. IOW, validation we got the __reserved[] size right.
7938 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
7942 static int __init
perf_event_sysfs_init(void)
7947 mutex_lock(&pmus_lock
);
7949 ret
= bus_register(&pmu_bus
);
7953 list_for_each_entry(pmu
, &pmus
, entry
) {
7954 if (!pmu
->name
|| pmu
->type
< 0)
7957 ret
= pmu_dev_alloc(pmu
);
7958 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
7960 pmu_bus_running
= 1;
7964 mutex_unlock(&pmus_lock
);
7968 device_initcall(perf_event_sysfs_init
);
7970 #ifdef CONFIG_CGROUP_PERF
7971 static struct cgroup_subsys_state
*
7972 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
7974 struct perf_cgroup
*jc
;
7976 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
7978 return ERR_PTR(-ENOMEM
);
7980 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
7983 return ERR_PTR(-ENOMEM
);
7989 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
7991 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
7993 free_percpu(jc
->info
);
7997 static int __perf_cgroup_move(void *info
)
7999 struct task_struct
*task
= info
;
8000 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
8004 static void perf_cgroup_attach(struct cgroup_subsys_state
*css
,
8005 struct cgroup_taskset
*tset
)
8007 struct task_struct
*task
;
8009 cgroup_taskset_for_each(task
, css
, tset
)
8010 task_function_call(task
, __perf_cgroup_move
, task
);
8013 static void perf_cgroup_exit(struct cgroup_subsys_state
*css
,
8014 struct cgroup_subsys_state
*old_css
,
8015 struct task_struct
*task
)
8018 * cgroup_exit() is called in the copy_process() failure path.
8019 * Ignore this case since the task hasn't ran yet, this avoids
8020 * trying to poke a half freed task state from generic code.
8022 if (!(task
->flags
& PF_EXITING
))
8025 task_function_call(task
, __perf_cgroup_move
, task
);
8028 struct cgroup_subsys perf_subsys
= {
8029 .name
= "perf_event",
8030 .subsys_id
= perf_subsys_id
,
8031 .css_alloc
= perf_cgroup_css_alloc
,
8032 .css_free
= perf_cgroup_css_free
,
8033 .exit
= perf_cgroup_exit
,
8034 .attach
= perf_cgroup_attach
,
8036 #endif /* CONFIG_CGROUP_PERF */