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 |\
123 PERF_FLAG_FD_CLOEXEC)
126 * branch priv levels that need permission checks
128 #define PERF_SAMPLE_BRANCH_PERM_PLM \
129 (PERF_SAMPLE_BRANCH_KERNEL |\
130 PERF_SAMPLE_BRANCH_HV)
133 EVENT_FLEXIBLE
= 0x1,
135 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
139 * perf_sched_events : >0 events exist
140 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
142 struct static_key_deferred perf_sched_events __read_mostly
;
143 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
144 static DEFINE_PER_CPU(atomic_t
, perf_branch_stack_events
);
146 static atomic_t nr_mmap_events __read_mostly
;
147 static atomic_t nr_comm_events __read_mostly
;
148 static atomic_t nr_task_events __read_mostly
;
149 static atomic_t nr_freq_events __read_mostly
;
151 static LIST_HEAD(pmus
);
152 static DEFINE_MUTEX(pmus_lock
);
153 static struct srcu_struct pmus_srcu
;
156 * perf event paranoia level:
157 * -1 - not paranoid at all
158 * 0 - disallow raw tracepoint access for unpriv
159 * 1 - disallow cpu events for unpriv
160 * 2 - disallow kernel profiling for unpriv
162 int sysctl_perf_event_paranoid __read_mostly
= 1;
164 /* Minimum for 512 kiB + 1 user control page */
165 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
168 * max perf event sample rate
170 #define DEFAULT_MAX_SAMPLE_RATE 100000
171 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
172 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
174 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
176 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
177 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
179 static int perf_sample_allowed_ns __read_mostly
=
180 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
182 void update_perf_cpu_limits(void)
184 u64 tmp
= perf_sample_period_ns
;
186 tmp
*= sysctl_perf_cpu_time_max_percent
;
188 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
191 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
193 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
194 void __user
*buffer
, size_t *lenp
,
197 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
202 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
203 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
204 update_perf_cpu_limits();
209 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
211 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
212 void __user
*buffer
, size_t *lenp
,
215 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
220 update_perf_cpu_limits();
226 * perf samples are done in some very critical code paths (NMIs).
227 * If they take too much CPU time, the system can lock up and not
228 * get any real work done. This will drop the sample rate when
229 * we detect that events are taking too long.
231 #define NR_ACCUMULATED_SAMPLES 128
232 static DEFINE_PER_CPU(u64
, running_sample_length
);
234 static void perf_duration_warn(struct irq_work
*w
)
236 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
237 u64 avg_local_sample_len
;
238 u64 local_samples_len
;
240 local_samples_len
= __get_cpu_var(running_sample_length
);
241 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
243 printk_ratelimited(KERN_WARNING
244 "perf interrupt took too long (%lld > %lld), lowering "
245 "kernel.perf_event_max_sample_rate to %d\n",
246 avg_local_sample_len
, allowed_ns
>> 1,
247 sysctl_perf_event_sample_rate
);
250 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
252 void perf_sample_event_took(u64 sample_len_ns
)
254 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
255 u64 avg_local_sample_len
;
256 u64 local_samples_len
;
261 /* decay the counter by 1 average sample */
262 local_samples_len
= __get_cpu_var(running_sample_length
);
263 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
264 local_samples_len
+= sample_len_ns
;
265 __get_cpu_var(running_sample_length
) = local_samples_len
;
268 * note: this will be biased artifically low until we have
269 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
270 * from having to maintain a count.
272 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
274 if (avg_local_sample_len
<= allowed_ns
)
277 if (max_samples_per_tick
<= 1)
280 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
281 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
282 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
284 update_perf_cpu_limits();
286 if (!irq_work_queue(&perf_duration_work
)) {
287 early_printk("perf interrupt took too long (%lld > %lld), lowering "
288 "kernel.perf_event_max_sample_rate to %d\n",
289 avg_local_sample_len
, allowed_ns
>> 1,
290 sysctl_perf_event_sample_rate
);
294 static atomic64_t perf_event_id
;
296 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
297 enum event_type_t event_type
);
299 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
300 enum event_type_t event_type
,
301 struct task_struct
*task
);
303 static void update_context_time(struct perf_event_context
*ctx
);
304 static u64
perf_event_time(struct perf_event
*event
);
306 void __weak
perf_event_print_debug(void) { }
308 extern __weak
const char *perf_pmu_name(void)
313 static inline u64
perf_clock(void)
315 return local_clock();
318 static inline struct perf_cpu_context
*
319 __get_cpu_context(struct perf_event_context
*ctx
)
321 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
324 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
325 struct perf_event_context
*ctx
)
327 raw_spin_lock(&cpuctx
->ctx
.lock
);
329 raw_spin_lock(&ctx
->lock
);
332 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
333 struct perf_event_context
*ctx
)
336 raw_spin_unlock(&ctx
->lock
);
337 raw_spin_unlock(&cpuctx
->ctx
.lock
);
340 #ifdef CONFIG_CGROUP_PERF
343 * perf_cgroup_info keeps track of time_enabled for a cgroup.
344 * This is a per-cpu dynamically allocated data structure.
346 struct perf_cgroup_info
{
352 struct cgroup_subsys_state css
;
353 struct perf_cgroup_info __percpu
*info
;
357 * Must ensure cgroup is pinned (css_get) before calling
358 * this function. In other words, we cannot call this function
359 * if there is no cgroup event for the current CPU context.
361 static inline struct perf_cgroup
*
362 perf_cgroup_from_task(struct task_struct
*task
)
364 return container_of(task_css(task
, perf_event_cgrp_id
),
365 struct perf_cgroup
, css
);
369 perf_cgroup_match(struct perf_event
*event
)
371 struct perf_event_context
*ctx
= event
->ctx
;
372 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
374 /* @event doesn't care about cgroup */
378 /* wants specific cgroup scope but @cpuctx isn't associated with any */
383 * Cgroup scoping is recursive. An event enabled for a cgroup is
384 * also enabled for all its descendant cgroups. If @cpuctx's
385 * cgroup is a descendant of @event's (the test covers identity
386 * case), it's a match.
388 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
389 event
->cgrp
->css
.cgroup
);
392 static inline void perf_put_cgroup(struct perf_event
*event
)
394 css_put(&event
->cgrp
->css
);
397 static inline void perf_detach_cgroup(struct perf_event
*event
)
399 perf_put_cgroup(event
);
403 static inline int is_cgroup_event(struct perf_event
*event
)
405 return event
->cgrp
!= NULL
;
408 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
410 struct perf_cgroup_info
*t
;
412 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
416 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
418 struct perf_cgroup_info
*info
;
423 info
= this_cpu_ptr(cgrp
->info
);
425 info
->time
+= now
- info
->timestamp
;
426 info
->timestamp
= now
;
429 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
431 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
433 __update_cgrp_time(cgrp_out
);
436 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
438 struct perf_cgroup
*cgrp
;
441 * ensure we access cgroup data only when needed and
442 * when we know the cgroup is pinned (css_get)
444 if (!is_cgroup_event(event
))
447 cgrp
= perf_cgroup_from_task(current
);
449 * Do not update time when cgroup is not active
451 if (cgrp
== event
->cgrp
)
452 __update_cgrp_time(event
->cgrp
);
456 perf_cgroup_set_timestamp(struct task_struct
*task
,
457 struct perf_event_context
*ctx
)
459 struct perf_cgroup
*cgrp
;
460 struct perf_cgroup_info
*info
;
463 * ctx->lock held by caller
464 * ensure we do not access cgroup data
465 * unless we have the cgroup pinned (css_get)
467 if (!task
|| !ctx
->nr_cgroups
)
470 cgrp
= perf_cgroup_from_task(task
);
471 info
= this_cpu_ptr(cgrp
->info
);
472 info
->timestamp
= ctx
->timestamp
;
475 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
476 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
479 * reschedule events based on the cgroup constraint of task.
481 * mode SWOUT : schedule out everything
482 * mode SWIN : schedule in based on cgroup for next
484 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
486 struct perf_cpu_context
*cpuctx
;
491 * disable interrupts to avoid geting nr_cgroup
492 * changes via __perf_event_disable(). Also
495 local_irq_save(flags
);
498 * we reschedule only in the presence of cgroup
499 * constrained events.
503 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
504 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
505 if (cpuctx
->unique_pmu
!= pmu
)
506 continue; /* ensure we process each cpuctx once */
509 * perf_cgroup_events says at least one
510 * context on this CPU has cgroup events.
512 * ctx->nr_cgroups reports the number of cgroup
513 * events for a context.
515 if (cpuctx
->ctx
.nr_cgroups
> 0) {
516 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
517 perf_pmu_disable(cpuctx
->ctx
.pmu
);
519 if (mode
& PERF_CGROUP_SWOUT
) {
520 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
522 * must not be done before ctxswout due
523 * to event_filter_match() in event_sched_out()
528 if (mode
& PERF_CGROUP_SWIN
) {
529 WARN_ON_ONCE(cpuctx
->cgrp
);
531 * set cgrp before ctxsw in to allow
532 * event_filter_match() to not have to pass
535 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
536 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
538 perf_pmu_enable(cpuctx
->ctx
.pmu
);
539 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
545 local_irq_restore(flags
);
548 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
549 struct task_struct
*next
)
551 struct perf_cgroup
*cgrp1
;
552 struct perf_cgroup
*cgrp2
= NULL
;
555 * we come here when we know perf_cgroup_events > 0
557 cgrp1
= perf_cgroup_from_task(task
);
560 * next is NULL when called from perf_event_enable_on_exec()
561 * that will systematically cause a cgroup_switch()
564 cgrp2
= perf_cgroup_from_task(next
);
567 * only schedule out current cgroup events if we know
568 * that we are switching to a different cgroup. Otherwise,
569 * do no touch the cgroup events.
572 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
575 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
576 struct task_struct
*task
)
578 struct perf_cgroup
*cgrp1
;
579 struct perf_cgroup
*cgrp2
= NULL
;
582 * we come here when we know perf_cgroup_events > 0
584 cgrp1
= perf_cgroup_from_task(task
);
586 /* prev can never be NULL */
587 cgrp2
= perf_cgroup_from_task(prev
);
590 * only need to schedule in cgroup events if we are changing
591 * cgroup during ctxsw. Cgroup events were not scheduled
592 * out of ctxsw out if that was not the case.
595 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
598 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
599 struct perf_event_attr
*attr
,
600 struct perf_event
*group_leader
)
602 struct perf_cgroup
*cgrp
;
603 struct cgroup_subsys_state
*css
;
604 struct fd f
= fdget(fd
);
610 css
= css_tryget_from_dir(f
.file
->f_dentry
, &perf_event_cgrp_subsys
);
616 cgrp
= container_of(css
, struct perf_cgroup
, css
);
620 * all events in a group must monitor
621 * the same cgroup because a task belongs
622 * to only one perf cgroup at a time
624 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
625 perf_detach_cgroup(event
);
634 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
636 struct perf_cgroup_info
*t
;
637 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
638 event
->shadow_ctx_time
= now
- t
->timestamp
;
642 perf_cgroup_defer_enabled(struct perf_event
*event
)
645 * when the current task's perf cgroup does not match
646 * the event's, we need to remember to call the
647 * perf_mark_enable() function the first time a task with
648 * a matching perf cgroup is scheduled in.
650 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
651 event
->cgrp_defer_enabled
= 1;
655 perf_cgroup_mark_enabled(struct perf_event
*event
,
656 struct perf_event_context
*ctx
)
658 struct perf_event
*sub
;
659 u64 tstamp
= perf_event_time(event
);
661 if (!event
->cgrp_defer_enabled
)
664 event
->cgrp_defer_enabled
= 0;
666 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
667 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
668 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
669 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
670 sub
->cgrp_defer_enabled
= 0;
674 #else /* !CONFIG_CGROUP_PERF */
677 perf_cgroup_match(struct perf_event
*event
)
682 static inline void perf_detach_cgroup(struct perf_event
*event
)
685 static inline int is_cgroup_event(struct perf_event
*event
)
690 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
695 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
699 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
703 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
704 struct task_struct
*next
)
708 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
709 struct task_struct
*task
)
713 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
714 struct perf_event_attr
*attr
,
715 struct perf_event
*group_leader
)
721 perf_cgroup_set_timestamp(struct task_struct
*task
,
722 struct perf_event_context
*ctx
)
727 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
732 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
736 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
742 perf_cgroup_defer_enabled(struct perf_event
*event
)
747 perf_cgroup_mark_enabled(struct perf_event
*event
,
748 struct perf_event_context
*ctx
)
754 * set default to be dependent on timer tick just
757 #define PERF_CPU_HRTIMER (1000 / HZ)
759 * function must be called with interrupts disbled
761 static enum hrtimer_restart
perf_cpu_hrtimer_handler(struct hrtimer
*hr
)
763 struct perf_cpu_context
*cpuctx
;
764 enum hrtimer_restart ret
= HRTIMER_NORESTART
;
767 WARN_ON(!irqs_disabled());
769 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
771 rotations
= perf_rotate_context(cpuctx
);
774 * arm timer if needed
777 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
778 ret
= HRTIMER_RESTART
;
784 /* CPU is going down */
785 void perf_cpu_hrtimer_cancel(int cpu
)
787 struct perf_cpu_context
*cpuctx
;
791 if (WARN_ON(cpu
!= smp_processor_id()))
794 local_irq_save(flags
);
798 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
799 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
801 if (pmu
->task_ctx_nr
== perf_sw_context
)
804 hrtimer_cancel(&cpuctx
->hrtimer
);
809 local_irq_restore(flags
);
812 static void __perf_cpu_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
814 struct hrtimer
*hr
= &cpuctx
->hrtimer
;
815 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
818 /* no multiplexing needed for SW PMU */
819 if (pmu
->task_ctx_nr
== perf_sw_context
)
823 * check default is sane, if not set then force to
824 * default interval (1/tick)
826 timer
= pmu
->hrtimer_interval_ms
;
828 timer
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
830 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
832 hrtimer_init(hr
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL_PINNED
);
833 hr
->function
= perf_cpu_hrtimer_handler
;
836 static void perf_cpu_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
838 struct hrtimer
*hr
= &cpuctx
->hrtimer
;
839 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
842 if (pmu
->task_ctx_nr
== perf_sw_context
)
845 if (hrtimer_active(hr
))
848 if (!hrtimer_callback_running(hr
))
849 __hrtimer_start_range_ns(hr
, cpuctx
->hrtimer_interval
,
850 0, HRTIMER_MODE_REL_PINNED
, 0);
853 void perf_pmu_disable(struct pmu
*pmu
)
855 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
857 pmu
->pmu_disable(pmu
);
860 void perf_pmu_enable(struct pmu
*pmu
)
862 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
864 pmu
->pmu_enable(pmu
);
867 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
870 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
871 * because they're strictly cpu affine and rotate_start is called with IRQs
872 * disabled, while rotate_context is called from IRQ context.
874 static void perf_pmu_rotate_start(struct pmu
*pmu
)
876 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
877 struct list_head
*head
= &__get_cpu_var(rotation_list
);
879 WARN_ON(!irqs_disabled());
881 if (list_empty(&cpuctx
->rotation_list
))
882 list_add(&cpuctx
->rotation_list
, head
);
885 static void get_ctx(struct perf_event_context
*ctx
)
887 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
890 static void put_ctx(struct perf_event_context
*ctx
)
892 if (atomic_dec_and_test(&ctx
->refcount
)) {
894 put_ctx(ctx
->parent_ctx
);
896 put_task_struct(ctx
->task
);
897 kfree_rcu(ctx
, rcu_head
);
901 static void unclone_ctx(struct perf_event_context
*ctx
)
903 if (ctx
->parent_ctx
) {
904 put_ctx(ctx
->parent_ctx
);
905 ctx
->parent_ctx
= NULL
;
910 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
913 * only top level events have the pid namespace they were created in
916 event
= event
->parent
;
918 return task_tgid_nr_ns(p
, event
->ns
);
921 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
924 * only top level events have the pid namespace they were created in
927 event
= event
->parent
;
929 return task_pid_nr_ns(p
, event
->ns
);
933 * If we inherit events we want to return the parent event id
936 static u64
primary_event_id(struct perf_event
*event
)
941 id
= event
->parent
->id
;
947 * Get the perf_event_context for a task and lock it.
948 * This has to cope with with the fact that until it is locked,
949 * the context could get moved to another task.
951 static struct perf_event_context
*
952 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
954 struct perf_event_context
*ctx
;
958 * One of the few rules of preemptible RCU is that one cannot do
959 * rcu_read_unlock() while holding a scheduler (or nested) lock when
960 * part of the read side critical section was preemptible -- see
961 * rcu_read_unlock_special().
963 * Since ctx->lock nests under rq->lock we must ensure the entire read
964 * side critical section is non-preemptible.
968 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
971 * If this context is a clone of another, it might
972 * get swapped for another underneath us by
973 * perf_event_task_sched_out, though the
974 * rcu_read_lock() protects us from any context
975 * getting freed. Lock the context and check if it
976 * got swapped before we could get the lock, and retry
977 * if so. If we locked the right context, then it
978 * can't get swapped on us any more.
980 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
981 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
982 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
988 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
989 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
999 * Get the context for a task and increment its pin_count so it
1000 * can't get swapped to another task. This also increments its
1001 * reference count so that the context can't get freed.
1003 static struct perf_event_context
*
1004 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1006 struct perf_event_context
*ctx
;
1007 unsigned long flags
;
1009 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1012 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1017 static void perf_unpin_context(struct perf_event_context
*ctx
)
1019 unsigned long flags
;
1021 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1023 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1027 * Update the record of the current time in a context.
1029 static void update_context_time(struct perf_event_context
*ctx
)
1031 u64 now
= perf_clock();
1033 ctx
->time
+= now
- ctx
->timestamp
;
1034 ctx
->timestamp
= now
;
1037 static u64
perf_event_time(struct perf_event
*event
)
1039 struct perf_event_context
*ctx
= event
->ctx
;
1041 if (is_cgroup_event(event
))
1042 return perf_cgroup_event_time(event
);
1044 return ctx
? ctx
->time
: 0;
1048 * Update the total_time_enabled and total_time_running fields for a event.
1049 * The caller of this function needs to hold the ctx->lock.
1051 static void update_event_times(struct perf_event
*event
)
1053 struct perf_event_context
*ctx
= event
->ctx
;
1056 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1057 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1060 * in cgroup mode, time_enabled represents
1061 * the time the event was enabled AND active
1062 * tasks were in the monitored cgroup. This is
1063 * independent of the activity of the context as
1064 * there may be a mix of cgroup and non-cgroup events.
1066 * That is why we treat cgroup events differently
1069 if (is_cgroup_event(event
))
1070 run_end
= perf_cgroup_event_time(event
);
1071 else if (ctx
->is_active
)
1072 run_end
= ctx
->time
;
1074 run_end
= event
->tstamp_stopped
;
1076 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1078 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1079 run_end
= event
->tstamp_stopped
;
1081 run_end
= perf_event_time(event
);
1083 event
->total_time_running
= run_end
- event
->tstamp_running
;
1088 * Update total_time_enabled and total_time_running for all events in a group.
1090 static void update_group_times(struct perf_event
*leader
)
1092 struct perf_event
*event
;
1094 update_event_times(leader
);
1095 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1096 update_event_times(event
);
1099 static struct list_head
*
1100 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1102 if (event
->attr
.pinned
)
1103 return &ctx
->pinned_groups
;
1105 return &ctx
->flexible_groups
;
1109 * Add a event from the lists for its context.
1110 * Must be called with ctx->mutex and ctx->lock held.
1113 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1115 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1116 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1119 * If we're a stand alone event or group leader, we go to the context
1120 * list, group events are kept attached to the group so that
1121 * perf_group_detach can, at all times, locate all siblings.
1123 if (event
->group_leader
== event
) {
1124 struct list_head
*list
;
1126 if (is_software_event(event
))
1127 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1129 list
= ctx_group_list(event
, ctx
);
1130 list_add_tail(&event
->group_entry
, list
);
1133 if (is_cgroup_event(event
))
1136 if (has_branch_stack(event
))
1137 ctx
->nr_branch_stack
++;
1139 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1140 if (!ctx
->nr_events
)
1141 perf_pmu_rotate_start(ctx
->pmu
);
1143 if (event
->attr
.inherit_stat
)
1150 * Initialize event state based on the perf_event_attr::disabled.
1152 static inline void perf_event__state_init(struct perf_event
*event
)
1154 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1155 PERF_EVENT_STATE_INACTIVE
;
1159 * Called at perf_event creation and when events are attached/detached from a
1162 static void perf_event__read_size(struct perf_event
*event
)
1164 int entry
= sizeof(u64
); /* value */
1168 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1169 size
+= sizeof(u64
);
1171 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1172 size
+= sizeof(u64
);
1174 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1175 entry
+= sizeof(u64
);
1177 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1178 nr
+= event
->group_leader
->nr_siblings
;
1179 size
+= sizeof(u64
);
1183 event
->read_size
= size
;
1186 static void perf_event__header_size(struct perf_event
*event
)
1188 struct perf_sample_data
*data
;
1189 u64 sample_type
= event
->attr
.sample_type
;
1192 perf_event__read_size(event
);
1194 if (sample_type
& PERF_SAMPLE_IP
)
1195 size
+= sizeof(data
->ip
);
1197 if (sample_type
& PERF_SAMPLE_ADDR
)
1198 size
+= sizeof(data
->addr
);
1200 if (sample_type
& PERF_SAMPLE_PERIOD
)
1201 size
+= sizeof(data
->period
);
1203 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1204 size
+= sizeof(data
->weight
);
1206 if (sample_type
& PERF_SAMPLE_READ
)
1207 size
+= event
->read_size
;
1209 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1210 size
+= sizeof(data
->data_src
.val
);
1212 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1213 size
+= sizeof(data
->txn
);
1215 event
->header_size
= size
;
1218 static void perf_event__id_header_size(struct perf_event
*event
)
1220 struct perf_sample_data
*data
;
1221 u64 sample_type
= event
->attr
.sample_type
;
1224 if (sample_type
& PERF_SAMPLE_TID
)
1225 size
+= sizeof(data
->tid_entry
);
1227 if (sample_type
& PERF_SAMPLE_TIME
)
1228 size
+= sizeof(data
->time
);
1230 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1231 size
+= sizeof(data
->id
);
1233 if (sample_type
& PERF_SAMPLE_ID
)
1234 size
+= sizeof(data
->id
);
1236 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1237 size
+= sizeof(data
->stream_id
);
1239 if (sample_type
& PERF_SAMPLE_CPU
)
1240 size
+= sizeof(data
->cpu_entry
);
1242 event
->id_header_size
= size
;
1245 static void perf_group_attach(struct perf_event
*event
)
1247 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1250 * We can have double attach due to group movement in perf_event_open.
1252 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1255 event
->attach_state
|= PERF_ATTACH_GROUP
;
1257 if (group_leader
== event
)
1260 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1261 !is_software_event(event
))
1262 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1264 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1265 group_leader
->nr_siblings
++;
1267 perf_event__header_size(group_leader
);
1269 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1270 perf_event__header_size(pos
);
1274 * Remove a event from the lists for its context.
1275 * Must be called with ctx->mutex and ctx->lock held.
1278 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1280 struct perf_cpu_context
*cpuctx
;
1282 * We can have double detach due to exit/hot-unplug + close.
1284 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1287 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1289 if (is_cgroup_event(event
)) {
1291 cpuctx
= __get_cpu_context(ctx
);
1293 * if there are no more cgroup events
1294 * then cler cgrp to avoid stale pointer
1295 * in update_cgrp_time_from_cpuctx()
1297 if (!ctx
->nr_cgroups
)
1298 cpuctx
->cgrp
= NULL
;
1301 if (has_branch_stack(event
))
1302 ctx
->nr_branch_stack
--;
1305 if (event
->attr
.inherit_stat
)
1308 list_del_rcu(&event
->event_entry
);
1310 if (event
->group_leader
== event
)
1311 list_del_init(&event
->group_entry
);
1313 update_group_times(event
);
1316 * If event was in error state, then keep it
1317 * that way, otherwise bogus counts will be
1318 * returned on read(). The only way to get out
1319 * of error state is by explicit re-enabling
1322 if (event
->state
> PERF_EVENT_STATE_OFF
)
1323 event
->state
= PERF_EVENT_STATE_OFF
;
1328 static void perf_group_detach(struct perf_event
*event
)
1330 struct perf_event
*sibling
, *tmp
;
1331 struct list_head
*list
= NULL
;
1334 * We can have double detach due to exit/hot-unplug + close.
1336 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1339 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1342 * If this is a sibling, remove it from its group.
1344 if (event
->group_leader
!= event
) {
1345 list_del_init(&event
->group_entry
);
1346 event
->group_leader
->nr_siblings
--;
1350 if (!list_empty(&event
->group_entry
))
1351 list
= &event
->group_entry
;
1354 * If this was a group event with sibling events then
1355 * upgrade the siblings to singleton events by adding them
1356 * to whatever list we are on.
1358 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1360 list_move_tail(&sibling
->group_entry
, list
);
1361 sibling
->group_leader
= sibling
;
1363 /* Inherit group flags from the previous leader */
1364 sibling
->group_flags
= event
->group_flags
;
1368 perf_event__header_size(event
->group_leader
);
1370 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1371 perf_event__header_size(tmp
);
1375 event_filter_match(struct perf_event
*event
)
1377 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1378 && perf_cgroup_match(event
);
1382 event_sched_out(struct perf_event
*event
,
1383 struct perf_cpu_context
*cpuctx
,
1384 struct perf_event_context
*ctx
)
1386 u64 tstamp
= perf_event_time(event
);
1389 * An event which could not be activated because of
1390 * filter mismatch still needs to have its timings
1391 * maintained, otherwise bogus information is return
1392 * via read() for time_enabled, time_running:
1394 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1395 && !event_filter_match(event
)) {
1396 delta
= tstamp
- event
->tstamp_stopped
;
1397 event
->tstamp_running
+= delta
;
1398 event
->tstamp_stopped
= tstamp
;
1401 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1404 perf_pmu_disable(event
->pmu
);
1406 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1407 if (event
->pending_disable
) {
1408 event
->pending_disable
= 0;
1409 event
->state
= PERF_EVENT_STATE_OFF
;
1411 event
->tstamp_stopped
= tstamp
;
1412 event
->pmu
->del(event
, 0);
1415 if (!is_software_event(event
))
1416 cpuctx
->active_oncpu
--;
1418 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1420 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1421 cpuctx
->exclusive
= 0;
1423 perf_pmu_enable(event
->pmu
);
1427 group_sched_out(struct perf_event
*group_event
,
1428 struct perf_cpu_context
*cpuctx
,
1429 struct perf_event_context
*ctx
)
1431 struct perf_event
*event
;
1432 int state
= group_event
->state
;
1434 event_sched_out(group_event
, cpuctx
, ctx
);
1437 * Schedule out siblings (if any):
1439 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1440 event_sched_out(event
, cpuctx
, ctx
);
1442 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1443 cpuctx
->exclusive
= 0;
1446 struct remove_event
{
1447 struct perf_event
*event
;
1452 * Cross CPU call to remove a performance event
1454 * We disable the event on the hardware level first. After that we
1455 * remove it from the context list.
1457 static int __perf_remove_from_context(void *info
)
1459 struct remove_event
*re
= info
;
1460 struct perf_event
*event
= re
->event
;
1461 struct perf_event_context
*ctx
= event
->ctx
;
1462 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1464 raw_spin_lock(&ctx
->lock
);
1465 event_sched_out(event
, cpuctx
, ctx
);
1466 if (re
->detach_group
)
1467 perf_group_detach(event
);
1468 list_del_event(event
, ctx
);
1469 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1471 cpuctx
->task_ctx
= NULL
;
1473 raw_spin_unlock(&ctx
->lock
);
1480 * Remove the event from a task's (or a CPU's) list of events.
1482 * CPU events are removed with a smp call. For task events we only
1483 * call when the task is on a CPU.
1485 * If event->ctx is a cloned context, callers must make sure that
1486 * every task struct that event->ctx->task could possibly point to
1487 * remains valid. This is OK when called from perf_release since
1488 * that only calls us on the top-level context, which can't be a clone.
1489 * When called from perf_event_exit_task, it's OK because the
1490 * context has been detached from its task.
1492 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1494 struct perf_event_context
*ctx
= event
->ctx
;
1495 struct task_struct
*task
= ctx
->task
;
1496 struct remove_event re
= {
1498 .detach_group
= detach_group
,
1501 lockdep_assert_held(&ctx
->mutex
);
1505 * Per cpu events are removed via an smp call and
1506 * the removal is always successful.
1508 cpu_function_call(event
->cpu
, __perf_remove_from_context
, &re
);
1513 if (!task_function_call(task
, __perf_remove_from_context
, &re
))
1516 raw_spin_lock_irq(&ctx
->lock
);
1518 * If we failed to find a running task, but find the context active now
1519 * that we've acquired the ctx->lock, retry.
1521 if (ctx
->is_active
) {
1522 raw_spin_unlock_irq(&ctx
->lock
);
1527 * Since the task isn't running, its safe to remove the event, us
1528 * holding the ctx->lock ensures the task won't get scheduled in.
1531 perf_group_detach(event
);
1532 list_del_event(event
, ctx
);
1533 raw_spin_unlock_irq(&ctx
->lock
);
1537 * Cross CPU call to disable a performance event
1539 int __perf_event_disable(void *info
)
1541 struct perf_event
*event
= info
;
1542 struct perf_event_context
*ctx
= event
->ctx
;
1543 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1546 * If this is a per-task event, need to check whether this
1547 * event's task is the current task on this cpu.
1549 * Can trigger due to concurrent perf_event_context_sched_out()
1550 * flipping contexts around.
1552 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1555 raw_spin_lock(&ctx
->lock
);
1558 * If the event is on, turn it off.
1559 * If it is in error state, leave it in error state.
1561 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1562 update_context_time(ctx
);
1563 update_cgrp_time_from_event(event
);
1564 update_group_times(event
);
1565 if (event
== event
->group_leader
)
1566 group_sched_out(event
, cpuctx
, ctx
);
1568 event_sched_out(event
, cpuctx
, ctx
);
1569 event
->state
= PERF_EVENT_STATE_OFF
;
1572 raw_spin_unlock(&ctx
->lock
);
1580 * If event->ctx is a cloned context, callers must make sure that
1581 * every task struct that event->ctx->task could possibly point to
1582 * remains valid. This condition is satisifed when called through
1583 * perf_event_for_each_child or perf_event_for_each because they
1584 * hold the top-level event's child_mutex, so any descendant that
1585 * goes to exit will block in sync_child_event.
1586 * When called from perf_pending_event it's OK because event->ctx
1587 * is the current context on this CPU and preemption is disabled,
1588 * hence we can't get into perf_event_task_sched_out for this context.
1590 void perf_event_disable(struct perf_event
*event
)
1592 struct perf_event_context
*ctx
= event
->ctx
;
1593 struct task_struct
*task
= ctx
->task
;
1597 * Disable the event on the cpu that it's on
1599 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1604 if (!task_function_call(task
, __perf_event_disable
, event
))
1607 raw_spin_lock_irq(&ctx
->lock
);
1609 * If the event is still active, we need to retry the cross-call.
1611 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1612 raw_spin_unlock_irq(&ctx
->lock
);
1614 * Reload the task pointer, it might have been changed by
1615 * a concurrent perf_event_context_sched_out().
1622 * Since we have the lock this context can't be scheduled
1623 * in, so we can change the state safely.
1625 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1626 update_group_times(event
);
1627 event
->state
= PERF_EVENT_STATE_OFF
;
1629 raw_spin_unlock_irq(&ctx
->lock
);
1631 EXPORT_SYMBOL_GPL(perf_event_disable
);
1633 static void perf_set_shadow_time(struct perf_event
*event
,
1634 struct perf_event_context
*ctx
,
1638 * use the correct time source for the time snapshot
1640 * We could get by without this by leveraging the
1641 * fact that to get to this function, the caller
1642 * has most likely already called update_context_time()
1643 * and update_cgrp_time_xx() and thus both timestamp
1644 * are identical (or very close). Given that tstamp is,
1645 * already adjusted for cgroup, we could say that:
1646 * tstamp - ctx->timestamp
1648 * tstamp - cgrp->timestamp.
1650 * Then, in perf_output_read(), the calculation would
1651 * work with no changes because:
1652 * - event is guaranteed scheduled in
1653 * - no scheduled out in between
1654 * - thus the timestamp would be the same
1656 * But this is a bit hairy.
1658 * So instead, we have an explicit cgroup call to remain
1659 * within the time time source all along. We believe it
1660 * is cleaner and simpler to understand.
1662 if (is_cgroup_event(event
))
1663 perf_cgroup_set_shadow_time(event
, tstamp
);
1665 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1668 #define MAX_INTERRUPTS (~0ULL)
1670 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1673 event_sched_in(struct perf_event
*event
,
1674 struct perf_cpu_context
*cpuctx
,
1675 struct perf_event_context
*ctx
)
1677 u64 tstamp
= perf_event_time(event
);
1680 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1683 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1684 event
->oncpu
= smp_processor_id();
1687 * Unthrottle events, since we scheduled we might have missed several
1688 * ticks already, also for a heavily scheduling task there is little
1689 * guarantee it'll get a tick in a timely manner.
1691 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1692 perf_log_throttle(event
, 1);
1693 event
->hw
.interrupts
= 0;
1697 * The new state must be visible before we turn it on in the hardware:
1701 perf_pmu_disable(event
->pmu
);
1703 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1704 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1710 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1712 perf_set_shadow_time(event
, ctx
, tstamp
);
1714 if (!is_software_event(event
))
1715 cpuctx
->active_oncpu
++;
1717 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1720 if (event
->attr
.exclusive
)
1721 cpuctx
->exclusive
= 1;
1724 perf_pmu_enable(event
->pmu
);
1730 group_sched_in(struct perf_event
*group_event
,
1731 struct perf_cpu_context
*cpuctx
,
1732 struct perf_event_context
*ctx
)
1734 struct perf_event
*event
, *partial_group
= NULL
;
1735 struct pmu
*pmu
= ctx
->pmu
;
1736 u64 now
= ctx
->time
;
1737 bool simulate
= false;
1739 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1742 pmu
->start_txn(pmu
);
1744 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1745 pmu
->cancel_txn(pmu
);
1746 perf_cpu_hrtimer_restart(cpuctx
);
1751 * Schedule in siblings as one group (if any):
1753 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1754 if (event_sched_in(event
, cpuctx
, ctx
)) {
1755 partial_group
= event
;
1760 if (!pmu
->commit_txn(pmu
))
1765 * Groups can be scheduled in as one unit only, so undo any
1766 * partial group before returning:
1767 * The events up to the failed event are scheduled out normally,
1768 * tstamp_stopped will be updated.
1770 * The failed events and the remaining siblings need to have
1771 * their timings updated as if they had gone thru event_sched_in()
1772 * and event_sched_out(). This is required to get consistent timings
1773 * across the group. This also takes care of the case where the group
1774 * could never be scheduled by ensuring tstamp_stopped is set to mark
1775 * the time the event was actually stopped, such that time delta
1776 * calculation in update_event_times() is correct.
1778 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1779 if (event
== partial_group
)
1783 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1784 event
->tstamp_stopped
= now
;
1786 event_sched_out(event
, cpuctx
, ctx
);
1789 event_sched_out(group_event
, cpuctx
, ctx
);
1791 pmu
->cancel_txn(pmu
);
1793 perf_cpu_hrtimer_restart(cpuctx
);
1799 * Work out whether we can put this event group on the CPU now.
1801 static int group_can_go_on(struct perf_event
*event
,
1802 struct perf_cpu_context
*cpuctx
,
1806 * Groups consisting entirely of software events can always go on.
1808 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1811 * If an exclusive group is already on, no other hardware
1814 if (cpuctx
->exclusive
)
1817 * If this group is exclusive and there are already
1818 * events on the CPU, it can't go on.
1820 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1823 * Otherwise, try to add it if all previous groups were able
1829 static void add_event_to_ctx(struct perf_event
*event
,
1830 struct perf_event_context
*ctx
)
1832 u64 tstamp
= perf_event_time(event
);
1834 list_add_event(event
, ctx
);
1835 perf_group_attach(event
);
1836 event
->tstamp_enabled
= tstamp
;
1837 event
->tstamp_running
= tstamp
;
1838 event
->tstamp_stopped
= tstamp
;
1841 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
1843 ctx_sched_in(struct perf_event_context
*ctx
,
1844 struct perf_cpu_context
*cpuctx
,
1845 enum event_type_t event_type
,
1846 struct task_struct
*task
);
1848 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
1849 struct perf_event_context
*ctx
,
1850 struct task_struct
*task
)
1852 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
1854 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
1855 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
1857 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
1861 * Cross CPU call to install and enable a performance event
1863 * Must be called with ctx->mutex held
1865 static int __perf_install_in_context(void *info
)
1867 struct perf_event
*event
= info
;
1868 struct perf_event_context
*ctx
= event
->ctx
;
1869 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1870 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
1871 struct task_struct
*task
= current
;
1873 perf_ctx_lock(cpuctx
, task_ctx
);
1874 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1877 * If there was an active task_ctx schedule it out.
1880 task_ctx_sched_out(task_ctx
);
1883 * If the context we're installing events in is not the
1884 * active task_ctx, flip them.
1886 if (ctx
->task
&& task_ctx
!= ctx
) {
1888 raw_spin_unlock(&task_ctx
->lock
);
1889 raw_spin_lock(&ctx
->lock
);
1894 cpuctx
->task_ctx
= task_ctx
;
1895 task
= task_ctx
->task
;
1898 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
1900 update_context_time(ctx
);
1902 * update cgrp time only if current cgrp
1903 * matches event->cgrp. Must be done before
1904 * calling add_event_to_ctx()
1906 update_cgrp_time_from_event(event
);
1908 add_event_to_ctx(event
, ctx
);
1911 * Schedule everything back in
1913 perf_event_sched_in(cpuctx
, task_ctx
, task
);
1915 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1916 perf_ctx_unlock(cpuctx
, task_ctx
);
1922 * Attach a performance event to a context
1924 * First we add the event to the list with the hardware enable bit
1925 * in event->hw_config cleared.
1927 * If the event is attached to a task which is on a CPU we use a smp
1928 * call to enable it in the task context. The task might have been
1929 * scheduled away, but we check this in the smp call again.
1932 perf_install_in_context(struct perf_event_context
*ctx
,
1933 struct perf_event
*event
,
1936 struct task_struct
*task
= ctx
->task
;
1938 lockdep_assert_held(&ctx
->mutex
);
1941 if (event
->cpu
!= -1)
1946 * Per cpu events are installed via an smp call and
1947 * the install is always successful.
1949 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1954 if (!task_function_call(task
, __perf_install_in_context
, event
))
1957 raw_spin_lock_irq(&ctx
->lock
);
1959 * If we failed to find a running task, but find the context active now
1960 * that we've acquired the ctx->lock, retry.
1962 if (ctx
->is_active
) {
1963 raw_spin_unlock_irq(&ctx
->lock
);
1968 * Since the task isn't running, its safe to add the event, us holding
1969 * the ctx->lock ensures the task won't get scheduled in.
1971 add_event_to_ctx(event
, ctx
);
1972 raw_spin_unlock_irq(&ctx
->lock
);
1976 * Put a event into inactive state and update time fields.
1977 * Enabling the leader of a group effectively enables all
1978 * the group members that aren't explicitly disabled, so we
1979 * have to update their ->tstamp_enabled also.
1980 * Note: this works for group members as well as group leaders
1981 * since the non-leader members' sibling_lists will be empty.
1983 static void __perf_event_mark_enabled(struct perf_event
*event
)
1985 struct perf_event
*sub
;
1986 u64 tstamp
= perf_event_time(event
);
1988 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1989 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1990 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1991 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1992 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1997 * Cross CPU call to enable a performance event
1999 static int __perf_event_enable(void *info
)
2001 struct perf_event
*event
= info
;
2002 struct perf_event_context
*ctx
= event
->ctx
;
2003 struct perf_event
*leader
= event
->group_leader
;
2004 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2008 * There's a time window between 'ctx->is_active' check
2009 * in perf_event_enable function and this place having:
2011 * - ctx->lock unlocked
2013 * where the task could be killed and 'ctx' deactivated
2014 * by perf_event_exit_task.
2016 if (!ctx
->is_active
)
2019 raw_spin_lock(&ctx
->lock
);
2020 update_context_time(ctx
);
2022 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2026 * set current task's cgroup time reference point
2028 perf_cgroup_set_timestamp(current
, ctx
);
2030 __perf_event_mark_enabled(event
);
2032 if (!event_filter_match(event
)) {
2033 if (is_cgroup_event(event
))
2034 perf_cgroup_defer_enabled(event
);
2039 * If the event is in a group and isn't the group leader,
2040 * then don't put it on unless the group is on.
2042 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2045 if (!group_can_go_on(event
, cpuctx
, 1)) {
2048 if (event
== leader
)
2049 err
= group_sched_in(event
, cpuctx
, ctx
);
2051 err
= event_sched_in(event
, cpuctx
, ctx
);
2056 * If this event can't go on and it's part of a
2057 * group, then the whole group has to come off.
2059 if (leader
!= event
) {
2060 group_sched_out(leader
, cpuctx
, ctx
);
2061 perf_cpu_hrtimer_restart(cpuctx
);
2063 if (leader
->attr
.pinned
) {
2064 update_group_times(leader
);
2065 leader
->state
= PERF_EVENT_STATE_ERROR
;
2070 raw_spin_unlock(&ctx
->lock
);
2078 * If event->ctx is a cloned context, callers must make sure that
2079 * every task struct that event->ctx->task could possibly point to
2080 * remains valid. This condition is satisfied when called through
2081 * perf_event_for_each_child or perf_event_for_each as described
2082 * for perf_event_disable.
2084 void perf_event_enable(struct perf_event
*event
)
2086 struct perf_event_context
*ctx
= event
->ctx
;
2087 struct task_struct
*task
= ctx
->task
;
2091 * Enable the event on the cpu that it's on
2093 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
2097 raw_spin_lock_irq(&ctx
->lock
);
2098 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2102 * If the event is in error state, clear that first.
2103 * That way, if we see the event in error state below, we
2104 * know that it has gone back into error state, as distinct
2105 * from the task having been scheduled away before the
2106 * cross-call arrived.
2108 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2109 event
->state
= PERF_EVENT_STATE_OFF
;
2112 if (!ctx
->is_active
) {
2113 __perf_event_mark_enabled(event
);
2117 raw_spin_unlock_irq(&ctx
->lock
);
2119 if (!task_function_call(task
, __perf_event_enable
, event
))
2122 raw_spin_lock_irq(&ctx
->lock
);
2125 * If the context is active and the event is still off,
2126 * we need to retry the cross-call.
2128 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
2130 * task could have been flipped by a concurrent
2131 * perf_event_context_sched_out()
2138 raw_spin_unlock_irq(&ctx
->lock
);
2140 EXPORT_SYMBOL_GPL(perf_event_enable
);
2142 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2145 * not supported on inherited events
2147 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2150 atomic_add(refresh
, &event
->event_limit
);
2151 perf_event_enable(event
);
2155 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2157 static void ctx_sched_out(struct perf_event_context
*ctx
,
2158 struct perf_cpu_context
*cpuctx
,
2159 enum event_type_t event_type
)
2161 struct perf_event
*event
;
2162 int is_active
= ctx
->is_active
;
2164 ctx
->is_active
&= ~event_type
;
2165 if (likely(!ctx
->nr_events
))
2168 update_context_time(ctx
);
2169 update_cgrp_time_from_cpuctx(cpuctx
);
2170 if (!ctx
->nr_active
)
2173 perf_pmu_disable(ctx
->pmu
);
2174 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2175 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2176 group_sched_out(event
, cpuctx
, ctx
);
2179 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2180 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2181 group_sched_out(event
, cpuctx
, ctx
);
2183 perf_pmu_enable(ctx
->pmu
);
2187 * Test whether two contexts are equivalent, i.e. whether they have both been
2188 * cloned from the same version of the same context.
2190 * Equivalence is measured using a generation number in the context that is
2191 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2192 * and list_del_event().
2194 static int context_equiv(struct perf_event_context
*ctx1
,
2195 struct perf_event_context
*ctx2
)
2197 /* Pinning disables the swap optimization */
2198 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2201 /* If ctx1 is the parent of ctx2 */
2202 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2205 /* If ctx2 is the parent of ctx1 */
2206 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2210 * If ctx1 and ctx2 have the same parent; we flatten the parent
2211 * hierarchy, see perf_event_init_context().
2213 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2214 ctx1
->parent_gen
== ctx2
->parent_gen
)
2221 static void __perf_event_sync_stat(struct perf_event
*event
,
2222 struct perf_event
*next_event
)
2226 if (!event
->attr
.inherit_stat
)
2230 * Update the event value, we cannot use perf_event_read()
2231 * because we're in the middle of a context switch and have IRQs
2232 * disabled, which upsets smp_call_function_single(), however
2233 * we know the event must be on the current CPU, therefore we
2234 * don't need to use it.
2236 switch (event
->state
) {
2237 case PERF_EVENT_STATE_ACTIVE
:
2238 event
->pmu
->read(event
);
2241 case PERF_EVENT_STATE_INACTIVE
:
2242 update_event_times(event
);
2250 * In order to keep per-task stats reliable we need to flip the event
2251 * values when we flip the contexts.
2253 value
= local64_read(&next_event
->count
);
2254 value
= local64_xchg(&event
->count
, value
);
2255 local64_set(&next_event
->count
, value
);
2257 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2258 swap(event
->total_time_running
, next_event
->total_time_running
);
2261 * Since we swizzled the values, update the user visible data too.
2263 perf_event_update_userpage(event
);
2264 perf_event_update_userpage(next_event
);
2267 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2268 struct perf_event_context
*next_ctx
)
2270 struct perf_event
*event
, *next_event
;
2275 update_context_time(ctx
);
2277 event
= list_first_entry(&ctx
->event_list
,
2278 struct perf_event
, event_entry
);
2280 next_event
= list_first_entry(&next_ctx
->event_list
,
2281 struct perf_event
, event_entry
);
2283 while (&event
->event_entry
!= &ctx
->event_list
&&
2284 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2286 __perf_event_sync_stat(event
, next_event
);
2288 event
= list_next_entry(event
, event_entry
);
2289 next_event
= list_next_entry(next_event
, event_entry
);
2293 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2294 struct task_struct
*next
)
2296 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2297 struct perf_event_context
*next_ctx
;
2298 struct perf_event_context
*parent
, *next_parent
;
2299 struct perf_cpu_context
*cpuctx
;
2305 cpuctx
= __get_cpu_context(ctx
);
2306 if (!cpuctx
->task_ctx
)
2310 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2314 parent
= rcu_dereference(ctx
->parent_ctx
);
2315 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2317 /* If neither context have a parent context; they cannot be clones. */
2318 if (!parent
&& !next_parent
)
2321 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2323 * Looks like the two contexts are clones, so we might be
2324 * able to optimize the context switch. We lock both
2325 * contexts and check that they are clones under the
2326 * lock (including re-checking that neither has been
2327 * uncloned in the meantime). It doesn't matter which
2328 * order we take the locks because no other cpu could
2329 * be trying to lock both of these tasks.
2331 raw_spin_lock(&ctx
->lock
);
2332 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2333 if (context_equiv(ctx
, next_ctx
)) {
2335 * XXX do we need a memory barrier of sorts
2336 * wrt to rcu_dereference() of perf_event_ctxp
2338 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2339 next
->perf_event_ctxp
[ctxn
] = ctx
;
2341 next_ctx
->task
= task
;
2344 perf_event_sync_stat(ctx
, next_ctx
);
2346 raw_spin_unlock(&next_ctx
->lock
);
2347 raw_spin_unlock(&ctx
->lock
);
2353 raw_spin_lock(&ctx
->lock
);
2354 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2355 cpuctx
->task_ctx
= NULL
;
2356 raw_spin_unlock(&ctx
->lock
);
2360 #define for_each_task_context_nr(ctxn) \
2361 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2364 * Called from scheduler to remove the events of the current task,
2365 * with interrupts disabled.
2367 * We stop each event and update the event value in event->count.
2369 * This does not protect us against NMI, but disable()
2370 * sets the disabled bit in the control field of event _before_
2371 * accessing the event control register. If a NMI hits, then it will
2372 * not restart the event.
2374 void __perf_event_task_sched_out(struct task_struct
*task
,
2375 struct task_struct
*next
)
2379 for_each_task_context_nr(ctxn
)
2380 perf_event_context_sched_out(task
, ctxn
, next
);
2383 * if cgroup events exist on this CPU, then we need
2384 * to check if we have to switch out PMU state.
2385 * cgroup event are system-wide mode only
2387 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2388 perf_cgroup_sched_out(task
, next
);
2391 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2393 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2395 if (!cpuctx
->task_ctx
)
2398 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2401 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2402 cpuctx
->task_ctx
= NULL
;
2406 * Called with IRQs disabled
2408 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2409 enum event_type_t event_type
)
2411 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2415 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2416 struct perf_cpu_context
*cpuctx
)
2418 struct perf_event
*event
;
2420 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2421 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2423 if (!event_filter_match(event
))
2426 /* may need to reset tstamp_enabled */
2427 if (is_cgroup_event(event
))
2428 perf_cgroup_mark_enabled(event
, ctx
);
2430 if (group_can_go_on(event
, cpuctx
, 1))
2431 group_sched_in(event
, cpuctx
, ctx
);
2434 * If this pinned group hasn't been scheduled,
2435 * put it in error state.
2437 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2438 update_group_times(event
);
2439 event
->state
= PERF_EVENT_STATE_ERROR
;
2445 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2446 struct perf_cpu_context
*cpuctx
)
2448 struct perf_event
*event
;
2451 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2452 /* Ignore events in OFF or ERROR state */
2453 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2456 * Listen to the 'cpu' scheduling filter constraint
2459 if (!event_filter_match(event
))
2462 /* may need to reset tstamp_enabled */
2463 if (is_cgroup_event(event
))
2464 perf_cgroup_mark_enabled(event
, ctx
);
2466 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2467 if (group_sched_in(event
, cpuctx
, ctx
))
2474 ctx_sched_in(struct perf_event_context
*ctx
,
2475 struct perf_cpu_context
*cpuctx
,
2476 enum event_type_t event_type
,
2477 struct task_struct
*task
)
2480 int is_active
= ctx
->is_active
;
2482 ctx
->is_active
|= event_type
;
2483 if (likely(!ctx
->nr_events
))
2487 ctx
->timestamp
= now
;
2488 perf_cgroup_set_timestamp(task
, ctx
);
2490 * First go through the list and put on any pinned groups
2491 * in order to give them the best chance of going on.
2493 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2494 ctx_pinned_sched_in(ctx
, cpuctx
);
2496 /* Then walk through the lower prio flexible groups */
2497 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2498 ctx_flexible_sched_in(ctx
, cpuctx
);
2501 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2502 enum event_type_t event_type
,
2503 struct task_struct
*task
)
2505 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2507 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2510 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2511 struct task_struct
*task
)
2513 struct perf_cpu_context
*cpuctx
;
2515 cpuctx
= __get_cpu_context(ctx
);
2516 if (cpuctx
->task_ctx
== ctx
)
2519 perf_ctx_lock(cpuctx
, ctx
);
2520 perf_pmu_disable(ctx
->pmu
);
2522 * We want to keep the following priority order:
2523 * cpu pinned (that don't need to move), task pinned,
2524 * cpu flexible, task flexible.
2526 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2529 cpuctx
->task_ctx
= ctx
;
2531 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2533 perf_pmu_enable(ctx
->pmu
);
2534 perf_ctx_unlock(cpuctx
, ctx
);
2537 * Since these rotations are per-cpu, we need to ensure the
2538 * cpu-context we got scheduled on is actually rotating.
2540 perf_pmu_rotate_start(ctx
->pmu
);
2544 * When sampling the branck stack in system-wide, it may be necessary
2545 * to flush the stack on context switch. This happens when the branch
2546 * stack does not tag its entries with the pid of the current task.
2547 * Otherwise it becomes impossible to associate a branch entry with a
2548 * task. This ambiguity is more likely to appear when the branch stack
2549 * supports priv level filtering and the user sets it to monitor only
2550 * at the user level (which could be a useful measurement in system-wide
2551 * mode). In that case, the risk is high of having a branch stack with
2552 * branch from multiple tasks. Flushing may mean dropping the existing
2553 * entries or stashing them somewhere in the PMU specific code layer.
2555 * This function provides the context switch callback to the lower code
2556 * layer. It is invoked ONLY when there is at least one system-wide context
2557 * with at least one active event using taken branch sampling.
2559 static void perf_branch_stack_sched_in(struct task_struct
*prev
,
2560 struct task_struct
*task
)
2562 struct perf_cpu_context
*cpuctx
;
2564 unsigned long flags
;
2566 /* no need to flush branch stack if not changing task */
2570 local_irq_save(flags
);
2574 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2575 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2578 * check if the context has at least one
2579 * event using PERF_SAMPLE_BRANCH_STACK
2581 if (cpuctx
->ctx
.nr_branch_stack
> 0
2582 && pmu
->flush_branch_stack
) {
2584 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2586 perf_pmu_disable(pmu
);
2588 pmu
->flush_branch_stack();
2590 perf_pmu_enable(pmu
);
2592 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2598 local_irq_restore(flags
);
2602 * Called from scheduler to add the events of the current task
2603 * with interrupts disabled.
2605 * We restore the event value and then enable it.
2607 * This does not protect us against NMI, but enable()
2608 * sets the enabled bit in the control field of event _before_
2609 * accessing the event control register. If a NMI hits, then it will
2610 * keep the event running.
2612 void __perf_event_task_sched_in(struct task_struct
*prev
,
2613 struct task_struct
*task
)
2615 struct perf_event_context
*ctx
;
2618 for_each_task_context_nr(ctxn
) {
2619 ctx
= task
->perf_event_ctxp
[ctxn
];
2623 perf_event_context_sched_in(ctx
, task
);
2626 * if cgroup events exist on this CPU, then we need
2627 * to check if we have to switch in PMU state.
2628 * cgroup event are system-wide mode only
2630 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2631 perf_cgroup_sched_in(prev
, task
);
2633 /* check for system-wide branch_stack events */
2634 if (atomic_read(&__get_cpu_var(perf_branch_stack_events
)))
2635 perf_branch_stack_sched_in(prev
, task
);
2638 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2640 u64 frequency
= event
->attr
.sample_freq
;
2641 u64 sec
= NSEC_PER_SEC
;
2642 u64 divisor
, dividend
;
2644 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2646 count_fls
= fls64(count
);
2647 nsec_fls
= fls64(nsec
);
2648 frequency_fls
= fls64(frequency
);
2652 * We got @count in @nsec, with a target of sample_freq HZ
2653 * the target period becomes:
2656 * period = -------------------
2657 * @nsec * sample_freq
2662 * Reduce accuracy by one bit such that @a and @b converge
2663 * to a similar magnitude.
2665 #define REDUCE_FLS(a, b) \
2667 if (a##_fls > b##_fls) { \
2677 * Reduce accuracy until either term fits in a u64, then proceed with
2678 * the other, so that finally we can do a u64/u64 division.
2680 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2681 REDUCE_FLS(nsec
, frequency
);
2682 REDUCE_FLS(sec
, count
);
2685 if (count_fls
+ sec_fls
> 64) {
2686 divisor
= nsec
* frequency
;
2688 while (count_fls
+ sec_fls
> 64) {
2689 REDUCE_FLS(count
, sec
);
2693 dividend
= count
* sec
;
2695 dividend
= count
* sec
;
2697 while (nsec_fls
+ frequency_fls
> 64) {
2698 REDUCE_FLS(nsec
, frequency
);
2702 divisor
= nsec
* frequency
;
2708 return div64_u64(dividend
, divisor
);
2711 static DEFINE_PER_CPU(int, perf_throttled_count
);
2712 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2714 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2716 struct hw_perf_event
*hwc
= &event
->hw
;
2717 s64 period
, sample_period
;
2720 period
= perf_calculate_period(event
, nsec
, count
);
2722 delta
= (s64
)(period
- hwc
->sample_period
);
2723 delta
= (delta
+ 7) / 8; /* low pass filter */
2725 sample_period
= hwc
->sample_period
+ delta
;
2730 hwc
->sample_period
= sample_period
;
2732 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2734 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2736 local64_set(&hwc
->period_left
, 0);
2739 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2744 * combine freq adjustment with unthrottling to avoid two passes over the
2745 * events. At the same time, make sure, having freq events does not change
2746 * the rate of unthrottling as that would introduce bias.
2748 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2751 struct perf_event
*event
;
2752 struct hw_perf_event
*hwc
;
2753 u64 now
, period
= TICK_NSEC
;
2757 * only need to iterate over all events iff:
2758 * - context have events in frequency mode (needs freq adjust)
2759 * - there are events to unthrottle on this cpu
2761 if (!(ctx
->nr_freq
|| needs_unthr
))
2764 raw_spin_lock(&ctx
->lock
);
2765 perf_pmu_disable(ctx
->pmu
);
2767 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2768 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2771 if (!event_filter_match(event
))
2774 perf_pmu_disable(event
->pmu
);
2778 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
2779 hwc
->interrupts
= 0;
2780 perf_log_throttle(event
, 1);
2781 event
->pmu
->start(event
, 0);
2784 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2788 * stop the event and update event->count
2790 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2792 now
= local64_read(&event
->count
);
2793 delta
= now
- hwc
->freq_count_stamp
;
2794 hwc
->freq_count_stamp
= now
;
2798 * reload only if value has changed
2799 * we have stopped the event so tell that
2800 * to perf_adjust_period() to avoid stopping it
2804 perf_adjust_period(event
, period
, delta
, false);
2806 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
2808 perf_pmu_enable(event
->pmu
);
2811 perf_pmu_enable(ctx
->pmu
);
2812 raw_spin_unlock(&ctx
->lock
);
2816 * Round-robin a context's events:
2818 static void rotate_ctx(struct perf_event_context
*ctx
)
2821 * Rotate the first entry last of non-pinned groups. Rotation might be
2822 * disabled by the inheritance code.
2824 if (!ctx
->rotate_disable
)
2825 list_rotate_left(&ctx
->flexible_groups
);
2829 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2830 * because they're strictly cpu affine and rotate_start is called with IRQs
2831 * disabled, while rotate_context is called from IRQ context.
2833 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2835 struct perf_event_context
*ctx
= NULL
;
2836 int rotate
= 0, remove
= 1;
2838 if (cpuctx
->ctx
.nr_events
) {
2840 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2844 ctx
= cpuctx
->task_ctx
;
2845 if (ctx
&& ctx
->nr_events
) {
2847 if (ctx
->nr_events
!= ctx
->nr_active
)
2854 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2855 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2857 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2859 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
2861 rotate_ctx(&cpuctx
->ctx
);
2865 perf_event_sched_in(cpuctx
, ctx
, current
);
2867 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2868 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2871 list_del_init(&cpuctx
->rotation_list
);
2876 #ifdef CONFIG_NO_HZ_FULL
2877 bool perf_event_can_stop_tick(void)
2879 if (atomic_read(&nr_freq_events
) ||
2880 __this_cpu_read(perf_throttled_count
))
2887 void perf_event_task_tick(void)
2889 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2890 struct perf_cpu_context
*cpuctx
, *tmp
;
2891 struct perf_event_context
*ctx
;
2894 WARN_ON(!irqs_disabled());
2896 __this_cpu_inc(perf_throttled_seq
);
2897 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
2899 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2901 perf_adjust_freq_unthr_context(ctx
, throttled
);
2903 ctx
= cpuctx
->task_ctx
;
2905 perf_adjust_freq_unthr_context(ctx
, throttled
);
2909 static int event_enable_on_exec(struct perf_event
*event
,
2910 struct perf_event_context
*ctx
)
2912 if (!event
->attr
.enable_on_exec
)
2915 event
->attr
.enable_on_exec
= 0;
2916 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2919 __perf_event_mark_enabled(event
);
2925 * Enable all of a task's events that have been marked enable-on-exec.
2926 * This expects task == current.
2928 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2930 struct perf_event
*event
;
2931 unsigned long flags
;
2935 local_irq_save(flags
);
2936 if (!ctx
|| !ctx
->nr_events
)
2940 * We must ctxsw out cgroup events to avoid conflict
2941 * when invoking perf_task_event_sched_in() later on
2942 * in this function. Otherwise we end up trying to
2943 * ctxswin cgroup events which are already scheduled
2946 perf_cgroup_sched_out(current
, NULL
);
2948 raw_spin_lock(&ctx
->lock
);
2949 task_ctx_sched_out(ctx
);
2951 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
2952 ret
= event_enable_on_exec(event
, ctx
);
2958 * Unclone this context if we enabled any event.
2963 raw_spin_unlock(&ctx
->lock
);
2966 * Also calls ctxswin for cgroup events, if any:
2968 perf_event_context_sched_in(ctx
, ctx
->task
);
2970 local_irq_restore(flags
);
2973 void perf_event_exec(void)
2975 struct perf_event_context
*ctx
;
2979 for_each_task_context_nr(ctxn
) {
2980 ctx
= current
->perf_event_ctxp
[ctxn
];
2984 perf_event_enable_on_exec(ctx
);
2990 * Cross CPU call to read the hardware event
2992 static void __perf_event_read(void *info
)
2994 struct perf_event
*event
= info
;
2995 struct perf_event_context
*ctx
= event
->ctx
;
2996 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2999 * If this is a task context, we need to check whether it is
3000 * the current task context of this cpu. If not it has been
3001 * scheduled out before the smp call arrived. In that case
3002 * event->count would have been updated to a recent sample
3003 * when the event was scheduled out.
3005 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3008 raw_spin_lock(&ctx
->lock
);
3009 if (ctx
->is_active
) {
3010 update_context_time(ctx
);
3011 update_cgrp_time_from_event(event
);
3013 update_event_times(event
);
3014 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3015 event
->pmu
->read(event
);
3016 raw_spin_unlock(&ctx
->lock
);
3019 static inline u64
perf_event_count(struct perf_event
*event
)
3021 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
3024 static u64
perf_event_read(struct perf_event
*event
)
3027 * If event is enabled and currently active on a CPU, update the
3028 * value in the event structure:
3030 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3031 smp_call_function_single(event
->oncpu
,
3032 __perf_event_read
, event
, 1);
3033 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3034 struct perf_event_context
*ctx
= event
->ctx
;
3035 unsigned long flags
;
3037 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3039 * may read while context is not active
3040 * (e.g., thread is blocked), in that case
3041 * we cannot update context time
3043 if (ctx
->is_active
) {
3044 update_context_time(ctx
);
3045 update_cgrp_time_from_event(event
);
3047 update_event_times(event
);
3048 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3051 return perf_event_count(event
);
3055 * Initialize the perf_event context in a task_struct:
3057 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3059 raw_spin_lock_init(&ctx
->lock
);
3060 mutex_init(&ctx
->mutex
);
3061 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3062 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3063 INIT_LIST_HEAD(&ctx
->event_list
);
3064 atomic_set(&ctx
->refcount
, 1);
3067 static struct perf_event_context
*
3068 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3070 struct perf_event_context
*ctx
;
3072 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3076 __perf_event_init_context(ctx
);
3079 get_task_struct(task
);
3086 static struct task_struct
*
3087 find_lively_task_by_vpid(pid_t vpid
)
3089 struct task_struct
*task
;
3096 task
= find_task_by_vpid(vpid
);
3098 get_task_struct(task
);
3102 return ERR_PTR(-ESRCH
);
3104 /* Reuse ptrace permission checks for now. */
3106 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3111 put_task_struct(task
);
3112 return ERR_PTR(err
);
3117 * Returns a matching context with refcount and pincount.
3119 static struct perf_event_context
*
3120 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
3122 struct perf_event_context
*ctx
;
3123 struct perf_cpu_context
*cpuctx
;
3124 unsigned long flags
;
3128 /* Must be root to operate on a CPU event: */
3129 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3130 return ERR_PTR(-EACCES
);
3133 * We could be clever and allow to attach a event to an
3134 * offline CPU and activate it when the CPU comes up, but
3137 if (!cpu_online(cpu
))
3138 return ERR_PTR(-ENODEV
);
3140 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3149 ctxn
= pmu
->task_ctx_nr
;
3154 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3158 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3160 ctx
= alloc_perf_context(pmu
, task
);
3166 mutex_lock(&task
->perf_event_mutex
);
3168 * If it has already passed perf_event_exit_task().
3169 * we must see PF_EXITING, it takes this mutex too.
3171 if (task
->flags
& PF_EXITING
)
3173 else if (task
->perf_event_ctxp
[ctxn
])
3178 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3180 mutex_unlock(&task
->perf_event_mutex
);
3182 if (unlikely(err
)) {
3194 return ERR_PTR(err
);
3197 static void perf_event_free_filter(struct perf_event
*event
);
3199 static void free_event_rcu(struct rcu_head
*head
)
3201 struct perf_event
*event
;
3203 event
= container_of(head
, struct perf_event
, rcu_head
);
3205 put_pid_ns(event
->ns
);
3206 perf_event_free_filter(event
);
3210 static void ring_buffer_put(struct ring_buffer
*rb
);
3211 static void ring_buffer_attach(struct perf_event
*event
,
3212 struct ring_buffer
*rb
);
3214 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3219 if (has_branch_stack(event
)) {
3220 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
3221 atomic_dec(&per_cpu(perf_branch_stack_events
, cpu
));
3223 if (is_cgroup_event(event
))
3224 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3227 static void unaccount_event(struct perf_event
*event
)
3232 if (event
->attach_state
& PERF_ATTACH_TASK
)
3233 static_key_slow_dec_deferred(&perf_sched_events
);
3234 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3235 atomic_dec(&nr_mmap_events
);
3236 if (event
->attr
.comm
)
3237 atomic_dec(&nr_comm_events
);
3238 if (event
->attr
.task
)
3239 atomic_dec(&nr_task_events
);
3240 if (event
->attr
.freq
)
3241 atomic_dec(&nr_freq_events
);
3242 if (is_cgroup_event(event
))
3243 static_key_slow_dec_deferred(&perf_sched_events
);
3244 if (has_branch_stack(event
))
3245 static_key_slow_dec_deferred(&perf_sched_events
);
3247 unaccount_event_cpu(event
, event
->cpu
);
3250 static void __free_event(struct perf_event
*event
)
3252 if (!event
->parent
) {
3253 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3254 put_callchain_buffers();
3258 event
->destroy(event
);
3261 put_ctx(event
->ctx
);
3263 call_rcu(&event
->rcu_head
, free_event_rcu
);
3265 static void free_event(struct perf_event
*event
)
3267 irq_work_sync(&event
->pending
);
3269 unaccount_event(event
);
3273 * Can happen when we close an event with re-directed output.
3275 * Since we have a 0 refcount, perf_mmap_close() will skip
3276 * over us; possibly making our ring_buffer_put() the last.
3278 mutex_lock(&event
->mmap_mutex
);
3279 ring_buffer_attach(event
, NULL
);
3280 mutex_unlock(&event
->mmap_mutex
);
3283 if (is_cgroup_event(event
))
3284 perf_detach_cgroup(event
);
3287 __free_event(event
);
3290 int perf_event_release_kernel(struct perf_event
*event
)
3292 struct perf_event_context
*ctx
= event
->ctx
;
3294 WARN_ON_ONCE(ctx
->parent_ctx
);
3296 * There are two ways this annotation is useful:
3298 * 1) there is a lock recursion from perf_event_exit_task
3299 * see the comment there.
3301 * 2) there is a lock-inversion with mmap_sem through
3302 * perf_event_read_group(), which takes faults while
3303 * holding ctx->mutex, however this is called after
3304 * the last filedesc died, so there is no possibility
3305 * to trigger the AB-BA case.
3307 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
3308 perf_remove_from_context(event
, true);
3309 mutex_unlock(&ctx
->mutex
);
3315 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3318 * Called when the last reference to the file is gone.
3320 static void put_event(struct perf_event
*event
)
3322 struct task_struct
*owner
;
3324 if (!atomic_long_dec_and_test(&event
->refcount
))
3328 owner
= ACCESS_ONCE(event
->owner
);
3330 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3331 * !owner it means the list deletion is complete and we can indeed
3332 * free this event, otherwise we need to serialize on
3333 * owner->perf_event_mutex.
3335 smp_read_barrier_depends();
3338 * Since delayed_put_task_struct() also drops the last
3339 * task reference we can safely take a new reference
3340 * while holding the rcu_read_lock().
3342 get_task_struct(owner
);
3347 mutex_lock(&owner
->perf_event_mutex
);
3349 * We have to re-check the event->owner field, if it is cleared
3350 * we raced with perf_event_exit_task(), acquiring the mutex
3351 * ensured they're done, and we can proceed with freeing the
3355 list_del_init(&event
->owner_entry
);
3356 mutex_unlock(&owner
->perf_event_mutex
);
3357 put_task_struct(owner
);
3360 perf_event_release_kernel(event
);
3363 static int perf_release(struct inode
*inode
, struct file
*file
)
3365 put_event(file
->private_data
);
3369 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3371 struct perf_event
*child
;
3377 mutex_lock(&event
->child_mutex
);
3378 total
+= perf_event_read(event
);
3379 *enabled
+= event
->total_time_enabled
+
3380 atomic64_read(&event
->child_total_time_enabled
);
3381 *running
+= event
->total_time_running
+
3382 atomic64_read(&event
->child_total_time_running
);
3384 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3385 total
+= perf_event_read(child
);
3386 *enabled
+= child
->total_time_enabled
;
3387 *running
+= child
->total_time_running
;
3389 mutex_unlock(&event
->child_mutex
);
3393 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3395 static int perf_event_read_group(struct perf_event
*event
,
3396 u64 read_format
, char __user
*buf
)
3398 struct perf_event
*leader
= event
->group_leader
, *sub
;
3399 int n
= 0, size
= 0, ret
= -EFAULT
;
3400 struct perf_event_context
*ctx
= leader
->ctx
;
3402 u64 count
, enabled
, running
;
3404 mutex_lock(&ctx
->mutex
);
3405 count
= perf_event_read_value(leader
, &enabled
, &running
);
3407 values
[n
++] = 1 + leader
->nr_siblings
;
3408 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3409 values
[n
++] = enabled
;
3410 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3411 values
[n
++] = running
;
3412 values
[n
++] = count
;
3413 if (read_format
& PERF_FORMAT_ID
)
3414 values
[n
++] = primary_event_id(leader
);
3416 size
= n
* sizeof(u64
);
3418 if (copy_to_user(buf
, values
, size
))
3423 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3426 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3427 if (read_format
& PERF_FORMAT_ID
)
3428 values
[n
++] = primary_event_id(sub
);
3430 size
= n
* sizeof(u64
);
3432 if (copy_to_user(buf
+ ret
, values
, size
)) {
3440 mutex_unlock(&ctx
->mutex
);
3445 static int perf_event_read_one(struct perf_event
*event
,
3446 u64 read_format
, char __user
*buf
)
3448 u64 enabled
, running
;
3452 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3453 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3454 values
[n
++] = enabled
;
3455 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3456 values
[n
++] = running
;
3457 if (read_format
& PERF_FORMAT_ID
)
3458 values
[n
++] = primary_event_id(event
);
3460 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3463 return n
* sizeof(u64
);
3467 * Read the performance event - simple non blocking version for now
3470 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3472 u64 read_format
= event
->attr
.read_format
;
3476 * Return end-of-file for a read on a event that is in
3477 * error state (i.e. because it was pinned but it couldn't be
3478 * scheduled on to the CPU at some point).
3480 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3483 if (count
< event
->read_size
)
3486 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3487 if (read_format
& PERF_FORMAT_GROUP
)
3488 ret
= perf_event_read_group(event
, read_format
, buf
);
3490 ret
= perf_event_read_one(event
, read_format
, buf
);
3496 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3498 struct perf_event
*event
= file
->private_data
;
3500 return perf_read_hw(event
, buf
, count
);
3503 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3505 struct perf_event
*event
= file
->private_data
;
3506 struct ring_buffer
*rb
;
3507 unsigned int events
= POLL_HUP
;
3510 * Pin the event->rb by taking event->mmap_mutex; otherwise
3511 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
3513 mutex_lock(&event
->mmap_mutex
);
3516 events
= atomic_xchg(&rb
->poll
, 0);
3517 mutex_unlock(&event
->mmap_mutex
);
3519 poll_wait(file
, &event
->waitq
, wait
);
3524 static void perf_event_reset(struct perf_event
*event
)
3526 (void)perf_event_read(event
);
3527 local64_set(&event
->count
, 0);
3528 perf_event_update_userpage(event
);
3532 * Holding the top-level event's child_mutex means that any
3533 * descendant process that has inherited this event will block
3534 * in sync_child_event if it goes to exit, thus satisfying the
3535 * task existence requirements of perf_event_enable/disable.
3537 static void perf_event_for_each_child(struct perf_event
*event
,
3538 void (*func
)(struct perf_event
*))
3540 struct perf_event
*child
;
3542 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3543 mutex_lock(&event
->child_mutex
);
3545 list_for_each_entry(child
, &event
->child_list
, child_list
)
3547 mutex_unlock(&event
->child_mutex
);
3550 static void perf_event_for_each(struct perf_event
*event
,
3551 void (*func
)(struct perf_event
*))
3553 struct perf_event_context
*ctx
= event
->ctx
;
3554 struct perf_event
*sibling
;
3556 WARN_ON_ONCE(ctx
->parent_ctx
);
3557 mutex_lock(&ctx
->mutex
);
3558 event
= event
->group_leader
;
3560 perf_event_for_each_child(event
, func
);
3561 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3562 perf_event_for_each_child(sibling
, func
);
3563 mutex_unlock(&ctx
->mutex
);
3566 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3568 struct perf_event_context
*ctx
= event
->ctx
;
3569 int ret
= 0, active
;
3572 if (!is_sampling_event(event
))
3575 if (copy_from_user(&value
, arg
, sizeof(value
)))
3581 raw_spin_lock_irq(&ctx
->lock
);
3582 if (event
->attr
.freq
) {
3583 if (value
> sysctl_perf_event_sample_rate
) {
3588 event
->attr
.sample_freq
= value
;
3590 event
->attr
.sample_period
= value
;
3591 event
->hw
.sample_period
= value
;
3594 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
3596 perf_pmu_disable(ctx
->pmu
);
3597 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3600 local64_set(&event
->hw
.period_left
, 0);
3603 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3604 perf_pmu_enable(ctx
->pmu
);
3608 raw_spin_unlock_irq(&ctx
->lock
);
3613 static const struct file_operations perf_fops
;
3615 static inline int perf_fget_light(int fd
, struct fd
*p
)
3617 struct fd f
= fdget(fd
);
3621 if (f
.file
->f_op
!= &perf_fops
) {
3629 static int perf_event_set_output(struct perf_event
*event
,
3630 struct perf_event
*output_event
);
3631 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3633 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3635 struct perf_event
*event
= file
->private_data
;
3636 void (*func
)(struct perf_event
*);
3640 case PERF_EVENT_IOC_ENABLE
:
3641 func
= perf_event_enable
;
3643 case PERF_EVENT_IOC_DISABLE
:
3644 func
= perf_event_disable
;
3646 case PERF_EVENT_IOC_RESET
:
3647 func
= perf_event_reset
;
3650 case PERF_EVENT_IOC_REFRESH
:
3651 return perf_event_refresh(event
, arg
);
3653 case PERF_EVENT_IOC_PERIOD
:
3654 return perf_event_period(event
, (u64 __user
*)arg
);
3656 case PERF_EVENT_IOC_ID
:
3658 u64 id
= primary_event_id(event
);
3660 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
3665 case PERF_EVENT_IOC_SET_OUTPUT
:
3669 struct perf_event
*output_event
;
3671 ret
= perf_fget_light(arg
, &output
);
3674 output_event
= output
.file
->private_data
;
3675 ret
= perf_event_set_output(event
, output_event
);
3678 ret
= perf_event_set_output(event
, NULL
);
3683 case PERF_EVENT_IOC_SET_FILTER
:
3684 return perf_event_set_filter(event
, (void __user
*)arg
);
3690 if (flags
& PERF_IOC_FLAG_GROUP
)
3691 perf_event_for_each(event
, func
);
3693 perf_event_for_each_child(event
, func
);
3698 int perf_event_task_enable(void)
3700 struct perf_event
*event
;
3702 mutex_lock(¤t
->perf_event_mutex
);
3703 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3704 perf_event_for_each_child(event
, perf_event_enable
);
3705 mutex_unlock(¤t
->perf_event_mutex
);
3710 int perf_event_task_disable(void)
3712 struct perf_event
*event
;
3714 mutex_lock(¤t
->perf_event_mutex
);
3715 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3716 perf_event_for_each_child(event
, perf_event_disable
);
3717 mutex_unlock(¤t
->perf_event_mutex
);
3722 static int perf_event_index(struct perf_event
*event
)
3724 if (event
->hw
.state
& PERF_HES_STOPPED
)
3727 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3730 return event
->pmu
->event_idx(event
);
3733 static void calc_timer_values(struct perf_event
*event
,
3740 *now
= perf_clock();
3741 ctx_time
= event
->shadow_ctx_time
+ *now
;
3742 *enabled
= ctx_time
- event
->tstamp_enabled
;
3743 *running
= ctx_time
- event
->tstamp_running
;
3746 static void perf_event_init_userpage(struct perf_event
*event
)
3748 struct perf_event_mmap_page
*userpg
;
3749 struct ring_buffer
*rb
;
3752 rb
= rcu_dereference(event
->rb
);
3756 userpg
= rb
->user_page
;
3758 /* Allow new userspace to detect that bit 0 is deprecated */
3759 userpg
->cap_bit0_is_deprecated
= 1;
3760 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
3766 void __weak
arch_perf_update_userpage(struct perf_event_mmap_page
*userpg
, u64 now
)
3771 * Callers need to ensure there can be no nesting of this function, otherwise
3772 * the seqlock logic goes bad. We can not serialize this because the arch
3773 * code calls this from NMI context.
3775 void perf_event_update_userpage(struct perf_event
*event
)
3777 struct perf_event_mmap_page
*userpg
;
3778 struct ring_buffer
*rb
;
3779 u64 enabled
, running
, now
;
3782 rb
= rcu_dereference(event
->rb
);
3787 * compute total_time_enabled, total_time_running
3788 * based on snapshot values taken when the event
3789 * was last scheduled in.
3791 * we cannot simply called update_context_time()
3792 * because of locking issue as we can be called in
3795 calc_timer_values(event
, &now
, &enabled
, &running
);
3797 userpg
= rb
->user_page
;
3799 * Disable preemption so as to not let the corresponding user-space
3800 * spin too long if we get preempted.
3805 userpg
->index
= perf_event_index(event
);
3806 userpg
->offset
= perf_event_count(event
);
3808 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3810 userpg
->time_enabled
= enabled
+
3811 atomic64_read(&event
->child_total_time_enabled
);
3813 userpg
->time_running
= running
+
3814 atomic64_read(&event
->child_total_time_running
);
3816 arch_perf_update_userpage(userpg
, now
);
3825 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3827 struct perf_event
*event
= vma
->vm_file
->private_data
;
3828 struct ring_buffer
*rb
;
3829 int ret
= VM_FAULT_SIGBUS
;
3831 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3832 if (vmf
->pgoff
== 0)
3838 rb
= rcu_dereference(event
->rb
);
3842 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3845 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3849 get_page(vmf
->page
);
3850 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3851 vmf
->page
->index
= vmf
->pgoff
;
3860 static void ring_buffer_attach(struct perf_event
*event
,
3861 struct ring_buffer
*rb
)
3863 struct ring_buffer
*old_rb
= NULL
;
3864 unsigned long flags
;
3868 * Should be impossible, we set this when removing
3869 * event->rb_entry and wait/clear when adding event->rb_entry.
3871 WARN_ON_ONCE(event
->rcu_pending
);
3874 event
->rcu_batches
= get_state_synchronize_rcu();
3875 event
->rcu_pending
= 1;
3877 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
3878 list_del_rcu(&event
->rb_entry
);
3879 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
3882 if (event
->rcu_pending
&& rb
) {
3883 cond_synchronize_rcu(event
->rcu_batches
);
3884 event
->rcu_pending
= 0;
3888 spin_lock_irqsave(&rb
->event_lock
, flags
);
3889 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
3890 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3893 rcu_assign_pointer(event
->rb
, rb
);
3896 ring_buffer_put(old_rb
);
3898 * Since we detached before setting the new rb, so that we
3899 * could attach the new rb, we could have missed a wakeup.
3902 wake_up_all(&event
->waitq
);
3906 static void ring_buffer_wakeup(struct perf_event
*event
)
3908 struct ring_buffer
*rb
;
3911 rb
= rcu_dereference(event
->rb
);
3913 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
3914 wake_up_all(&event
->waitq
);
3919 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3921 struct ring_buffer
*rb
;
3923 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3927 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3929 struct ring_buffer
*rb
;
3932 rb
= rcu_dereference(event
->rb
);
3934 if (!atomic_inc_not_zero(&rb
->refcount
))
3942 static void ring_buffer_put(struct ring_buffer
*rb
)
3944 if (!atomic_dec_and_test(&rb
->refcount
))
3947 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
3949 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3952 static void perf_mmap_open(struct vm_area_struct
*vma
)
3954 struct perf_event
*event
= vma
->vm_file
->private_data
;
3956 atomic_inc(&event
->mmap_count
);
3957 atomic_inc(&event
->rb
->mmap_count
);
3961 * A buffer can be mmap()ed multiple times; either directly through the same
3962 * event, or through other events by use of perf_event_set_output().
3964 * In order to undo the VM accounting done by perf_mmap() we need to destroy
3965 * the buffer here, where we still have a VM context. This means we need
3966 * to detach all events redirecting to us.
3968 static void perf_mmap_close(struct vm_area_struct
*vma
)
3970 struct perf_event
*event
= vma
->vm_file
->private_data
;
3972 struct ring_buffer
*rb
= ring_buffer_get(event
);
3973 struct user_struct
*mmap_user
= rb
->mmap_user
;
3974 int mmap_locked
= rb
->mmap_locked
;
3975 unsigned long size
= perf_data_size(rb
);
3977 atomic_dec(&rb
->mmap_count
);
3979 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
3982 ring_buffer_attach(event
, NULL
);
3983 mutex_unlock(&event
->mmap_mutex
);
3985 /* If there's still other mmap()s of this buffer, we're done. */
3986 if (atomic_read(&rb
->mmap_count
))
3990 * No other mmap()s, detach from all other events that might redirect
3991 * into the now unreachable buffer. Somewhat complicated by the
3992 * fact that rb::event_lock otherwise nests inside mmap_mutex.
3996 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
3997 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
3999 * This event is en-route to free_event() which will
4000 * detach it and remove it from the list.
4006 mutex_lock(&event
->mmap_mutex
);
4008 * Check we didn't race with perf_event_set_output() which can
4009 * swizzle the rb from under us while we were waiting to
4010 * acquire mmap_mutex.
4012 * If we find a different rb; ignore this event, a next
4013 * iteration will no longer find it on the list. We have to
4014 * still restart the iteration to make sure we're not now
4015 * iterating the wrong list.
4017 if (event
->rb
== rb
)
4018 ring_buffer_attach(event
, NULL
);
4020 mutex_unlock(&event
->mmap_mutex
);
4024 * Restart the iteration; either we're on the wrong list or
4025 * destroyed its integrity by doing a deletion.
4032 * It could be there's still a few 0-ref events on the list; they'll
4033 * get cleaned up by free_event() -- they'll also still have their
4034 * ref on the rb and will free it whenever they are done with it.
4036 * Aside from that, this buffer is 'fully' detached and unmapped,
4037 * undo the VM accounting.
4040 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4041 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4042 free_uid(mmap_user
);
4045 ring_buffer_put(rb
); /* could be last */
4048 static const struct vm_operations_struct perf_mmap_vmops
= {
4049 .open
= perf_mmap_open
,
4050 .close
= perf_mmap_close
,
4051 .fault
= perf_mmap_fault
,
4052 .page_mkwrite
= perf_mmap_fault
,
4055 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4057 struct perf_event
*event
= file
->private_data
;
4058 unsigned long user_locked
, user_lock_limit
;
4059 struct user_struct
*user
= current_user();
4060 unsigned long locked
, lock_limit
;
4061 struct ring_buffer
*rb
;
4062 unsigned long vma_size
;
4063 unsigned long nr_pages
;
4064 long user_extra
, extra
;
4065 int ret
= 0, flags
= 0;
4068 * Don't allow mmap() of inherited per-task counters. This would
4069 * create a performance issue due to all children writing to the
4072 if (event
->cpu
== -1 && event
->attr
.inherit
)
4075 if (!(vma
->vm_flags
& VM_SHARED
))
4078 vma_size
= vma
->vm_end
- vma
->vm_start
;
4079 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4082 * If we have rb pages ensure they're a power-of-two number, so we
4083 * can do bitmasks instead of modulo.
4085 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4088 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4091 if (vma
->vm_pgoff
!= 0)
4094 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4096 mutex_lock(&event
->mmap_mutex
);
4098 if (event
->rb
->nr_pages
!= nr_pages
) {
4103 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4105 * Raced against perf_mmap_close() through
4106 * perf_event_set_output(). Try again, hope for better
4109 mutex_unlock(&event
->mmap_mutex
);
4116 user_extra
= nr_pages
+ 1;
4117 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4120 * Increase the limit linearly with more CPUs:
4122 user_lock_limit
*= num_online_cpus();
4124 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4127 if (user_locked
> user_lock_limit
)
4128 extra
= user_locked
- user_lock_limit
;
4130 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4131 lock_limit
>>= PAGE_SHIFT
;
4132 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4134 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4135 !capable(CAP_IPC_LOCK
)) {
4142 if (vma
->vm_flags
& VM_WRITE
)
4143 flags
|= RING_BUFFER_WRITABLE
;
4145 rb
= rb_alloc(nr_pages
,
4146 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4154 atomic_set(&rb
->mmap_count
, 1);
4155 rb
->mmap_locked
= extra
;
4156 rb
->mmap_user
= get_current_user();
4158 atomic_long_add(user_extra
, &user
->locked_vm
);
4159 vma
->vm_mm
->pinned_vm
+= extra
;
4161 ring_buffer_attach(event
, rb
);
4163 perf_event_init_userpage(event
);
4164 perf_event_update_userpage(event
);
4168 atomic_inc(&event
->mmap_count
);
4169 mutex_unlock(&event
->mmap_mutex
);
4172 * Since pinned accounting is per vm we cannot allow fork() to copy our
4175 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4176 vma
->vm_ops
= &perf_mmap_vmops
;
4181 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4183 struct inode
*inode
= file_inode(filp
);
4184 struct perf_event
*event
= filp
->private_data
;
4187 mutex_lock(&inode
->i_mutex
);
4188 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4189 mutex_unlock(&inode
->i_mutex
);
4197 static const struct file_operations perf_fops
= {
4198 .llseek
= no_llseek
,
4199 .release
= perf_release
,
4202 .unlocked_ioctl
= perf_ioctl
,
4203 .compat_ioctl
= perf_ioctl
,
4205 .fasync
= perf_fasync
,
4211 * If there's data, ensure we set the poll() state and publish everything
4212 * to user-space before waking everybody up.
4215 void perf_event_wakeup(struct perf_event
*event
)
4217 ring_buffer_wakeup(event
);
4219 if (event
->pending_kill
) {
4220 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
4221 event
->pending_kill
= 0;
4225 static void perf_pending_event(struct irq_work
*entry
)
4227 struct perf_event
*event
= container_of(entry
,
4228 struct perf_event
, pending
);
4230 if (event
->pending_disable
) {
4231 event
->pending_disable
= 0;
4232 __perf_event_disable(event
);
4235 if (event
->pending_wakeup
) {
4236 event
->pending_wakeup
= 0;
4237 perf_event_wakeup(event
);
4242 * We assume there is only KVM supporting the callbacks.
4243 * Later on, we might change it to a list if there is
4244 * another virtualization implementation supporting the callbacks.
4246 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4248 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4250 perf_guest_cbs
= cbs
;
4253 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4255 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4257 perf_guest_cbs
= NULL
;
4260 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4263 perf_output_sample_regs(struct perf_output_handle
*handle
,
4264 struct pt_regs
*regs
, u64 mask
)
4268 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4269 sizeof(mask
) * BITS_PER_BYTE
) {
4272 val
= perf_reg_value(regs
, bit
);
4273 perf_output_put(handle
, val
);
4277 static void perf_sample_regs_user(struct perf_regs_user
*regs_user
,
4278 struct pt_regs
*regs
)
4280 if (!user_mode(regs
)) {
4282 regs
= task_pt_regs(current
);
4288 regs_user
->regs
= regs
;
4289 regs_user
->abi
= perf_reg_abi(current
);
4294 * Get remaining task size from user stack pointer.
4296 * It'd be better to take stack vma map and limit this more
4297 * precisly, but there's no way to get it safely under interrupt,
4298 * so using TASK_SIZE as limit.
4300 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
4302 unsigned long addr
= perf_user_stack_pointer(regs
);
4304 if (!addr
|| addr
>= TASK_SIZE
)
4307 return TASK_SIZE
- addr
;
4311 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
4312 struct pt_regs
*regs
)
4316 /* No regs, no stack pointer, no dump. */
4321 * Check if we fit in with the requested stack size into the:
4323 * If we don't, we limit the size to the TASK_SIZE.
4325 * - remaining sample size
4326 * If we don't, we customize the stack size to
4327 * fit in to the remaining sample size.
4330 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
4331 stack_size
= min(stack_size
, (u16
) task_size
);
4333 /* Current header size plus static size and dynamic size. */
4334 header_size
+= 2 * sizeof(u64
);
4336 /* Do we fit in with the current stack dump size? */
4337 if ((u16
) (header_size
+ stack_size
) < header_size
) {
4339 * If we overflow the maximum size for the sample,
4340 * we customize the stack dump size to fit in.
4342 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
4343 stack_size
= round_up(stack_size
, sizeof(u64
));
4350 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
4351 struct pt_regs
*regs
)
4353 /* Case of a kernel thread, nothing to dump */
4356 perf_output_put(handle
, size
);
4365 * - the size requested by user or the best one we can fit
4366 * in to the sample max size
4368 * - user stack dump data
4370 * - the actual dumped size
4374 perf_output_put(handle
, dump_size
);
4377 sp
= perf_user_stack_pointer(regs
);
4378 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
4379 dyn_size
= dump_size
- rem
;
4381 perf_output_skip(handle
, rem
);
4384 perf_output_put(handle
, dyn_size
);
4388 static void __perf_event_header__init_id(struct perf_event_header
*header
,
4389 struct perf_sample_data
*data
,
4390 struct perf_event
*event
)
4392 u64 sample_type
= event
->attr
.sample_type
;
4394 data
->type
= sample_type
;
4395 header
->size
+= event
->id_header_size
;
4397 if (sample_type
& PERF_SAMPLE_TID
) {
4398 /* namespace issues */
4399 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
4400 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
4403 if (sample_type
& PERF_SAMPLE_TIME
)
4404 data
->time
= perf_clock();
4406 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
4407 data
->id
= primary_event_id(event
);
4409 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4410 data
->stream_id
= event
->id
;
4412 if (sample_type
& PERF_SAMPLE_CPU
) {
4413 data
->cpu_entry
.cpu
= raw_smp_processor_id();
4414 data
->cpu_entry
.reserved
= 0;
4418 void perf_event_header__init_id(struct perf_event_header
*header
,
4419 struct perf_sample_data
*data
,
4420 struct perf_event
*event
)
4422 if (event
->attr
.sample_id_all
)
4423 __perf_event_header__init_id(header
, data
, event
);
4426 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
4427 struct perf_sample_data
*data
)
4429 u64 sample_type
= data
->type
;
4431 if (sample_type
& PERF_SAMPLE_TID
)
4432 perf_output_put(handle
, data
->tid_entry
);
4434 if (sample_type
& PERF_SAMPLE_TIME
)
4435 perf_output_put(handle
, data
->time
);
4437 if (sample_type
& PERF_SAMPLE_ID
)
4438 perf_output_put(handle
, data
->id
);
4440 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4441 perf_output_put(handle
, data
->stream_id
);
4443 if (sample_type
& PERF_SAMPLE_CPU
)
4444 perf_output_put(handle
, data
->cpu_entry
);
4446 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
4447 perf_output_put(handle
, data
->id
);
4450 void perf_event__output_id_sample(struct perf_event
*event
,
4451 struct perf_output_handle
*handle
,
4452 struct perf_sample_data
*sample
)
4454 if (event
->attr
.sample_id_all
)
4455 __perf_event__output_id_sample(handle
, sample
);
4458 static void perf_output_read_one(struct perf_output_handle
*handle
,
4459 struct perf_event
*event
,
4460 u64 enabled
, u64 running
)
4462 u64 read_format
= event
->attr
.read_format
;
4466 values
[n
++] = perf_event_count(event
);
4467 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4468 values
[n
++] = enabled
+
4469 atomic64_read(&event
->child_total_time_enabled
);
4471 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4472 values
[n
++] = running
+
4473 atomic64_read(&event
->child_total_time_running
);
4475 if (read_format
& PERF_FORMAT_ID
)
4476 values
[n
++] = primary_event_id(event
);
4478 __output_copy(handle
, values
, n
* sizeof(u64
));
4482 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
4484 static void perf_output_read_group(struct perf_output_handle
*handle
,
4485 struct perf_event
*event
,
4486 u64 enabled
, u64 running
)
4488 struct perf_event
*leader
= event
->group_leader
, *sub
;
4489 u64 read_format
= event
->attr
.read_format
;
4493 values
[n
++] = 1 + leader
->nr_siblings
;
4495 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4496 values
[n
++] = enabled
;
4498 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4499 values
[n
++] = running
;
4501 if (leader
!= event
)
4502 leader
->pmu
->read(leader
);
4504 values
[n
++] = perf_event_count(leader
);
4505 if (read_format
& PERF_FORMAT_ID
)
4506 values
[n
++] = primary_event_id(leader
);
4508 __output_copy(handle
, values
, n
* sizeof(u64
));
4510 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4513 if ((sub
!= event
) &&
4514 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
4515 sub
->pmu
->read(sub
);
4517 values
[n
++] = perf_event_count(sub
);
4518 if (read_format
& PERF_FORMAT_ID
)
4519 values
[n
++] = primary_event_id(sub
);
4521 __output_copy(handle
, values
, n
* sizeof(u64
));
4525 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
4526 PERF_FORMAT_TOTAL_TIME_RUNNING)
4528 static void perf_output_read(struct perf_output_handle
*handle
,
4529 struct perf_event
*event
)
4531 u64 enabled
= 0, running
= 0, now
;
4532 u64 read_format
= event
->attr
.read_format
;
4535 * compute total_time_enabled, total_time_running
4536 * based on snapshot values taken when the event
4537 * was last scheduled in.
4539 * we cannot simply called update_context_time()
4540 * because of locking issue as we are called in
4543 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
4544 calc_timer_values(event
, &now
, &enabled
, &running
);
4546 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
4547 perf_output_read_group(handle
, event
, enabled
, running
);
4549 perf_output_read_one(handle
, event
, enabled
, running
);
4552 void perf_output_sample(struct perf_output_handle
*handle
,
4553 struct perf_event_header
*header
,
4554 struct perf_sample_data
*data
,
4555 struct perf_event
*event
)
4557 u64 sample_type
= data
->type
;
4559 perf_output_put(handle
, *header
);
4561 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
4562 perf_output_put(handle
, data
->id
);
4564 if (sample_type
& PERF_SAMPLE_IP
)
4565 perf_output_put(handle
, data
->ip
);
4567 if (sample_type
& PERF_SAMPLE_TID
)
4568 perf_output_put(handle
, data
->tid_entry
);
4570 if (sample_type
& PERF_SAMPLE_TIME
)
4571 perf_output_put(handle
, data
->time
);
4573 if (sample_type
& PERF_SAMPLE_ADDR
)
4574 perf_output_put(handle
, data
->addr
);
4576 if (sample_type
& PERF_SAMPLE_ID
)
4577 perf_output_put(handle
, data
->id
);
4579 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4580 perf_output_put(handle
, data
->stream_id
);
4582 if (sample_type
& PERF_SAMPLE_CPU
)
4583 perf_output_put(handle
, data
->cpu_entry
);
4585 if (sample_type
& PERF_SAMPLE_PERIOD
)
4586 perf_output_put(handle
, data
->period
);
4588 if (sample_type
& PERF_SAMPLE_READ
)
4589 perf_output_read(handle
, event
);
4591 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4592 if (data
->callchain
) {
4595 if (data
->callchain
)
4596 size
+= data
->callchain
->nr
;
4598 size
*= sizeof(u64
);
4600 __output_copy(handle
, data
->callchain
, size
);
4603 perf_output_put(handle
, nr
);
4607 if (sample_type
& PERF_SAMPLE_RAW
) {
4609 perf_output_put(handle
, data
->raw
->size
);
4610 __output_copy(handle
, data
->raw
->data
,
4617 .size
= sizeof(u32
),
4620 perf_output_put(handle
, raw
);
4624 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4625 if (data
->br_stack
) {
4628 size
= data
->br_stack
->nr
4629 * sizeof(struct perf_branch_entry
);
4631 perf_output_put(handle
, data
->br_stack
->nr
);
4632 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
4635 * we always store at least the value of nr
4638 perf_output_put(handle
, nr
);
4642 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4643 u64 abi
= data
->regs_user
.abi
;
4646 * If there are no regs to dump, notice it through
4647 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
4649 perf_output_put(handle
, abi
);
4652 u64 mask
= event
->attr
.sample_regs_user
;
4653 perf_output_sample_regs(handle
,
4654 data
->regs_user
.regs
,
4659 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
4660 perf_output_sample_ustack(handle
,
4661 data
->stack_user_size
,
4662 data
->regs_user
.regs
);
4665 if (sample_type
& PERF_SAMPLE_WEIGHT
)
4666 perf_output_put(handle
, data
->weight
);
4668 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
4669 perf_output_put(handle
, data
->data_src
.val
);
4671 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
4672 perf_output_put(handle
, data
->txn
);
4674 if (!event
->attr
.watermark
) {
4675 int wakeup_events
= event
->attr
.wakeup_events
;
4677 if (wakeup_events
) {
4678 struct ring_buffer
*rb
= handle
->rb
;
4679 int events
= local_inc_return(&rb
->events
);
4681 if (events
>= wakeup_events
) {
4682 local_sub(wakeup_events
, &rb
->events
);
4683 local_inc(&rb
->wakeup
);
4689 void perf_prepare_sample(struct perf_event_header
*header
,
4690 struct perf_sample_data
*data
,
4691 struct perf_event
*event
,
4692 struct pt_regs
*regs
)
4694 u64 sample_type
= event
->attr
.sample_type
;
4696 header
->type
= PERF_RECORD_SAMPLE
;
4697 header
->size
= sizeof(*header
) + event
->header_size
;
4700 header
->misc
|= perf_misc_flags(regs
);
4702 __perf_event_header__init_id(header
, data
, event
);
4704 if (sample_type
& PERF_SAMPLE_IP
)
4705 data
->ip
= perf_instruction_pointer(regs
);
4707 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4710 data
->callchain
= perf_callchain(event
, regs
);
4712 if (data
->callchain
)
4713 size
+= data
->callchain
->nr
;
4715 header
->size
+= size
* sizeof(u64
);
4718 if (sample_type
& PERF_SAMPLE_RAW
) {
4719 int size
= sizeof(u32
);
4722 size
+= data
->raw
->size
;
4724 size
+= sizeof(u32
);
4726 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4727 header
->size
+= size
;
4730 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4731 int size
= sizeof(u64
); /* nr */
4732 if (data
->br_stack
) {
4733 size
+= data
->br_stack
->nr
4734 * sizeof(struct perf_branch_entry
);
4736 header
->size
+= size
;
4739 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4740 /* regs dump ABI info */
4741 int size
= sizeof(u64
);
4743 perf_sample_regs_user(&data
->regs_user
, regs
);
4745 if (data
->regs_user
.regs
) {
4746 u64 mask
= event
->attr
.sample_regs_user
;
4747 size
+= hweight64(mask
) * sizeof(u64
);
4750 header
->size
+= size
;
4753 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
4755 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
4756 * processed as the last one or have additional check added
4757 * in case new sample type is added, because we could eat
4758 * up the rest of the sample size.
4760 struct perf_regs_user
*uregs
= &data
->regs_user
;
4761 u16 stack_size
= event
->attr
.sample_stack_user
;
4762 u16 size
= sizeof(u64
);
4765 perf_sample_regs_user(uregs
, regs
);
4767 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
4771 * If there is something to dump, add space for the dump
4772 * itself and for the field that tells the dynamic size,
4773 * which is how many have been actually dumped.
4776 size
+= sizeof(u64
) + stack_size
;
4778 data
->stack_user_size
= stack_size
;
4779 header
->size
+= size
;
4783 static void perf_event_output(struct perf_event
*event
,
4784 struct perf_sample_data
*data
,
4785 struct pt_regs
*regs
)
4787 struct perf_output_handle handle
;
4788 struct perf_event_header header
;
4790 /* protect the callchain buffers */
4793 perf_prepare_sample(&header
, data
, event
, regs
);
4795 if (perf_output_begin(&handle
, event
, header
.size
))
4798 perf_output_sample(&handle
, &header
, data
, event
);
4800 perf_output_end(&handle
);
4810 struct perf_read_event
{
4811 struct perf_event_header header
;
4818 perf_event_read_event(struct perf_event
*event
,
4819 struct task_struct
*task
)
4821 struct perf_output_handle handle
;
4822 struct perf_sample_data sample
;
4823 struct perf_read_event read_event
= {
4825 .type
= PERF_RECORD_READ
,
4827 .size
= sizeof(read_event
) + event
->read_size
,
4829 .pid
= perf_event_pid(event
, task
),
4830 .tid
= perf_event_tid(event
, task
),
4834 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4835 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
4839 perf_output_put(&handle
, read_event
);
4840 perf_output_read(&handle
, event
);
4841 perf_event__output_id_sample(event
, &handle
, &sample
);
4843 perf_output_end(&handle
);
4846 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
4849 perf_event_aux_ctx(struct perf_event_context
*ctx
,
4850 perf_event_aux_output_cb output
,
4853 struct perf_event
*event
;
4855 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4856 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4858 if (!event_filter_match(event
))
4860 output(event
, data
);
4865 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
4866 struct perf_event_context
*task_ctx
)
4868 struct perf_cpu_context
*cpuctx
;
4869 struct perf_event_context
*ctx
;
4874 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4875 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4876 if (cpuctx
->unique_pmu
!= pmu
)
4878 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
4881 ctxn
= pmu
->task_ctx_nr
;
4884 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4886 perf_event_aux_ctx(ctx
, output
, data
);
4888 put_cpu_ptr(pmu
->pmu_cpu_context
);
4893 perf_event_aux_ctx(task_ctx
, output
, data
);
4900 * task tracking -- fork/exit
4902 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
4905 struct perf_task_event
{
4906 struct task_struct
*task
;
4907 struct perf_event_context
*task_ctx
;
4910 struct perf_event_header header
;
4920 static int perf_event_task_match(struct perf_event
*event
)
4922 return event
->attr
.comm
|| event
->attr
.mmap
||
4923 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
4927 static void perf_event_task_output(struct perf_event
*event
,
4930 struct perf_task_event
*task_event
= data
;
4931 struct perf_output_handle handle
;
4932 struct perf_sample_data sample
;
4933 struct task_struct
*task
= task_event
->task
;
4934 int ret
, size
= task_event
->event_id
.header
.size
;
4936 if (!perf_event_task_match(event
))
4939 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4941 ret
= perf_output_begin(&handle
, event
,
4942 task_event
->event_id
.header
.size
);
4946 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4947 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4949 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4950 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4952 perf_output_put(&handle
, task_event
->event_id
);
4954 perf_event__output_id_sample(event
, &handle
, &sample
);
4956 perf_output_end(&handle
);
4958 task_event
->event_id
.header
.size
= size
;
4961 static void perf_event_task(struct task_struct
*task
,
4962 struct perf_event_context
*task_ctx
,
4965 struct perf_task_event task_event
;
4967 if (!atomic_read(&nr_comm_events
) &&
4968 !atomic_read(&nr_mmap_events
) &&
4969 !atomic_read(&nr_task_events
))
4972 task_event
= (struct perf_task_event
){
4974 .task_ctx
= task_ctx
,
4977 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4979 .size
= sizeof(task_event
.event_id
),
4985 .time
= perf_clock(),
4989 perf_event_aux(perf_event_task_output
,
4994 void perf_event_fork(struct task_struct
*task
)
4996 perf_event_task(task
, NULL
, 1);
5003 struct perf_comm_event
{
5004 struct task_struct
*task
;
5009 struct perf_event_header header
;
5016 static int perf_event_comm_match(struct perf_event
*event
)
5018 return event
->attr
.comm
;
5021 static void perf_event_comm_output(struct perf_event
*event
,
5024 struct perf_comm_event
*comm_event
= data
;
5025 struct perf_output_handle handle
;
5026 struct perf_sample_data sample
;
5027 int size
= comm_event
->event_id
.header
.size
;
5030 if (!perf_event_comm_match(event
))
5033 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5034 ret
= perf_output_begin(&handle
, event
,
5035 comm_event
->event_id
.header
.size
);
5040 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5041 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5043 perf_output_put(&handle
, comm_event
->event_id
);
5044 __output_copy(&handle
, comm_event
->comm
,
5045 comm_event
->comm_size
);
5047 perf_event__output_id_sample(event
, &handle
, &sample
);
5049 perf_output_end(&handle
);
5051 comm_event
->event_id
.header
.size
= size
;
5054 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5056 char comm
[TASK_COMM_LEN
];
5059 memset(comm
, 0, sizeof(comm
));
5060 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5061 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5063 comm_event
->comm
= comm
;
5064 comm_event
->comm_size
= size
;
5066 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5068 perf_event_aux(perf_event_comm_output
,
5073 void perf_event_comm(struct task_struct
*task
)
5075 struct perf_comm_event comm_event
;
5077 if (!atomic_read(&nr_comm_events
))
5080 comm_event
= (struct perf_comm_event
){
5086 .type
= PERF_RECORD_COMM
,
5095 perf_event_comm_event(&comm_event
);
5102 struct perf_mmap_event
{
5103 struct vm_area_struct
*vma
;
5105 const char *file_name
;
5112 struct perf_event_header header
;
5122 static int perf_event_mmap_match(struct perf_event
*event
,
5125 struct perf_mmap_event
*mmap_event
= data
;
5126 struct vm_area_struct
*vma
= mmap_event
->vma
;
5127 int executable
= vma
->vm_flags
& VM_EXEC
;
5129 return (!executable
&& event
->attr
.mmap_data
) ||
5130 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5133 static void perf_event_mmap_output(struct perf_event
*event
,
5136 struct perf_mmap_event
*mmap_event
= data
;
5137 struct perf_output_handle handle
;
5138 struct perf_sample_data sample
;
5139 int size
= mmap_event
->event_id
.header
.size
;
5142 if (!perf_event_mmap_match(event
, data
))
5145 if (event
->attr
.mmap2
) {
5146 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5147 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5148 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5149 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5150 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5153 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5154 ret
= perf_output_begin(&handle
, event
,
5155 mmap_event
->event_id
.header
.size
);
5159 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5160 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5162 perf_output_put(&handle
, mmap_event
->event_id
);
5164 if (event
->attr
.mmap2
) {
5165 perf_output_put(&handle
, mmap_event
->maj
);
5166 perf_output_put(&handle
, mmap_event
->min
);
5167 perf_output_put(&handle
, mmap_event
->ino
);
5168 perf_output_put(&handle
, mmap_event
->ino_generation
);
5171 __output_copy(&handle
, mmap_event
->file_name
,
5172 mmap_event
->file_size
);
5174 perf_event__output_id_sample(event
, &handle
, &sample
);
5176 perf_output_end(&handle
);
5178 mmap_event
->event_id
.header
.size
= size
;
5181 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5183 struct vm_area_struct
*vma
= mmap_event
->vma
;
5184 struct file
*file
= vma
->vm_file
;
5185 int maj
= 0, min
= 0;
5186 u64 ino
= 0, gen
= 0;
5193 struct inode
*inode
;
5196 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5202 * d_path() works from the end of the rb backwards, so we
5203 * need to add enough zero bytes after the string to handle
5204 * the 64bit alignment we do later.
5206 name
= d_path(&file
->f_path
, buf
, PATH_MAX
- sizeof(u64
));
5211 inode
= file_inode(vma
->vm_file
);
5212 dev
= inode
->i_sb
->s_dev
;
5214 gen
= inode
->i_generation
;
5219 name
= (char *)arch_vma_name(vma
);
5223 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
5224 vma
->vm_end
>= vma
->vm_mm
->brk
) {
5228 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
5229 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
5239 strlcpy(tmp
, name
, sizeof(tmp
));
5243 * Since our buffer works in 8 byte units we need to align our string
5244 * size to a multiple of 8. However, we must guarantee the tail end is
5245 * zero'd out to avoid leaking random bits to userspace.
5247 size
= strlen(name
)+1;
5248 while (!IS_ALIGNED(size
, sizeof(u64
)))
5249 name
[size
++] = '\0';
5251 mmap_event
->file_name
= name
;
5252 mmap_event
->file_size
= size
;
5253 mmap_event
->maj
= maj
;
5254 mmap_event
->min
= min
;
5255 mmap_event
->ino
= ino
;
5256 mmap_event
->ino_generation
= gen
;
5258 if (!(vma
->vm_flags
& VM_EXEC
))
5259 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
5261 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
5263 perf_event_aux(perf_event_mmap_output
,
5270 void perf_event_mmap(struct vm_area_struct
*vma
)
5272 struct perf_mmap_event mmap_event
;
5274 if (!atomic_read(&nr_mmap_events
))
5277 mmap_event
= (struct perf_mmap_event
){
5283 .type
= PERF_RECORD_MMAP
,
5284 .misc
= PERF_RECORD_MISC_USER
,
5289 .start
= vma
->vm_start
,
5290 .len
= vma
->vm_end
- vma
->vm_start
,
5291 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
5293 /* .maj (attr_mmap2 only) */
5294 /* .min (attr_mmap2 only) */
5295 /* .ino (attr_mmap2 only) */
5296 /* .ino_generation (attr_mmap2 only) */
5299 perf_event_mmap_event(&mmap_event
);
5303 * IRQ throttle logging
5306 static void perf_log_throttle(struct perf_event
*event
, int enable
)
5308 struct perf_output_handle handle
;
5309 struct perf_sample_data sample
;
5313 struct perf_event_header header
;
5317 } throttle_event
= {
5319 .type
= PERF_RECORD_THROTTLE
,
5321 .size
= sizeof(throttle_event
),
5323 .time
= perf_clock(),
5324 .id
= primary_event_id(event
),
5325 .stream_id
= event
->id
,
5329 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
5331 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
5333 ret
= perf_output_begin(&handle
, event
,
5334 throttle_event
.header
.size
);
5338 perf_output_put(&handle
, throttle_event
);
5339 perf_event__output_id_sample(event
, &handle
, &sample
);
5340 perf_output_end(&handle
);
5344 * Generic event overflow handling, sampling.
5347 static int __perf_event_overflow(struct perf_event
*event
,
5348 int throttle
, struct perf_sample_data
*data
,
5349 struct pt_regs
*regs
)
5351 int events
= atomic_read(&event
->event_limit
);
5352 struct hw_perf_event
*hwc
= &event
->hw
;
5357 * Non-sampling counters might still use the PMI to fold short
5358 * hardware counters, ignore those.
5360 if (unlikely(!is_sampling_event(event
)))
5363 seq
= __this_cpu_read(perf_throttled_seq
);
5364 if (seq
!= hwc
->interrupts_seq
) {
5365 hwc
->interrupts_seq
= seq
;
5366 hwc
->interrupts
= 1;
5369 if (unlikely(throttle
5370 && hwc
->interrupts
>= max_samples_per_tick
)) {
5371 __this_cpu_inc(perf_throttled_count
);
5372 hwc
->interrupts
= MAX_INTERRUPTS
;
5373 perf_log_throttle(event
, 0);
5374 tick_nohz_full_kick();
5379 if (event
->attr
.freq
) {
5380 u64 now
= perf_clock();
5381 s64 delta
= now
- hwc
->freq_time_stamp
;
5383 hwc
->freq_time_stamp
= now
;
5385 if (delta
> 0 && delta
< 2*TICK_NSEC
)
5386 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
5390 * XXX event_limit might not quite work as expected on inherited
5394 event
->pending_kill
= POLL_IN
;
5395 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
5397 event
->pending_kill
= POLL_HUP
;
5398 event
->pending_disable
= 1;
5399 irq_work_queue(&event
->pending
);
5402 if (event
->overflow_handler
)
5403 event
->overflow_handler(event
, data
, regs
);
5405 perf_event_output(event
, data
, regs
);
5407 if (event
->fasync
&& event
->pending_kill
) {
5408 event
->pending_wakeup
= 1;
5409 irq_work_queue(&event
->pending
);
5415 int perf_event_overflow(struct perf_event
*event
,
5416 struct perf_sample_data
*data
,
5417 struct pt_regs
*regs
)
5419 return __perf_event_overflow(event
, 1, data
, regs
);
5423 * Generic software event infrastructure
5426 struct swevent_htable
{
5427 struct swevent_hlist
*swevent_hlist
;
5428 struct mutex hlist_mutex
;
5431 /* Recursion avoidance in each contexts */
5432 int recursion
[PERF_NR_CONTEXTS
];
5434 /* Keeps track of cpu being initialized/exited */
5438 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
5441 * We directly increment event->count and keep a second value in
5442 * event->hw.period_left to count intervals. This period event
5443 * is kept in the range [-sample_period, 0] so that we can use the
5447 u64
perf_swevent_set_period(struct perf_event
*event
)
5449 struct hw_perf_event
*hwc
= &event
->hw
;
5450 u64 period
= hwc
->last_period
;
5454 hwc
->last_period
= hwc
->sample_period
;
5457 old
= val
= local64_read(&hwc
->period_left
);
5461 nr
= div64_u64(period
+ val
, period
);
5462 offset
= nr
* period
;
5464 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
5470 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
5471 struct perf_sample_data
*data
,
5472 struct pt_regs
*regs
)
5474 struct hw_perf_event
*hwc
= &event
->hw
;
5478 overflow
= perf_swevent_set_period(event
);
5480 if (hwc
->interrupts
== MAX_INTERRUPTS
)
5483 for (; overflow
; overflow
--) {
5484 if (__perf_event_overflow(event
, throttle
,
5487 * We inhibit the overflow from happening when
5488 * hwc->interrupts == MAX_INTERRUPTS.
5496 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
5497 struct perf_sample_data
*data
,
5498 struct pt_regs
*regs
)
5500 struct hw_perf_event
*hwc
= &event
->hw
;
5502 local64_add(nr
, &event
->count
);
5507 if (!is_sampling_event(event
))
5510 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
5512 return perf_swevent_overflow(event
, 1, data
, regs
);
5514 data
->period
= event
->hw
.last_period
;
5516 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
5517 return perf_swevent_overflow(event
, 1, data
, regs
);
5519 if (local64_add_negative(nr
, &hwc
->period_left
))
5522 perf_swevent_overflow(event
, 0, data
, regs
);
5525 static int perf_exclude_event(struct perf_event
*event
,
5526 struct pt_regs
*regs
)
5528 if (event
->hw
.state
& PERF_HES_STOPPED
)
5532 if (event
->attr
.exclude_user
&& user_mode(regs
))
5535 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
5542 static int perf_swevent_match(struct perf_event
*event
,
5543 enum perf_type_id type
,
5545 struct perf_sample_data
*data
,
5546 struct pt_regs
*regs
)
5548 if (event
->attr
.type
!= type
)
5551 if (event
->attr
.config
!= event_id
)
5554 if (perf_exclude_event(event
, regs
))
5560 static inline u64
swevent_hash(u64 type
, u32 event_id
)
5562 u64 val
= event_id
| (type
<< 32);
5564 return hash_64(val
, SWEVENT_HLIST_BITS
);
5567 static inline struct hlist_head
*
5568 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
5570 u64 hash
= swevent_hash(type
, event_id
);
5572 return &hlist
->heads
[hash
];
5575 /* For the read side: events when they trigger */
5576 static inline struct hlist_head
*
5577 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
5579 struct swevent_hlist
*hlist
;
5581 hlist
= rcu_dereference(swhash
->swevent_hlist
);
5585 return __find_swevent_head(hlist
, type
, event_id
);
5588 /* For the event head insertion and removal in the hlist */
5589 static inline struct hlist_head
*
5590 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
5592 struct swevent_hlist
*hlist
;
5593 u32 event_id
= event
->attr
.config
;
5594 u64 type
= event
->attr
.type
;
5597 * Event scheduling is always serialized against hlist allocation
5598 * and release. Which makes the protected version suitable here.
5599 * The context lock guarantees that.
5601 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
5602 lockdep_is_held(&event
->ctx
->lock
));
5606 return __find_swevent_head(hlist
, type
, event_id
);
5609 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
5611 struct perf_sample_data
*data
,
5612 struct pt_regs
*regs
)
5614 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5615 struct perf_event
*event
;
5616 struct hlist_head
*head
;
5619 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
5623 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5624 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
5625 perf_swevent_event(event
, nr
, data
, regs
);
5631 int perf_swevent_get_recursion_context(void)
5633 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5635 return get_recursion_context(swhash
->recursion
);
5637 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
5639 inline void perf_swevent_put_recursion_context(int rctx
)
5641 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5643 put_recursion_context(swhash
->recursion
, rctx
);
5646 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
5648 struct perf_sample_data data
;
5651 preempt_disable_notrace();
5652 rctx
= perf_swevent_get_recursion_context();
5656 perf_sample_data_init(&data
, addr
, 0);
5658 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
5660 perf_swevent_put_recursion_context(rctx
);
5661 preempt_enable_notrace();
5664 static void perf_swevent_read(struct perf_event
*event
)
5668 static int perf_swevent_add(struct perf_event
*event
, int flags
)
5670 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5671 struct hw_perf_event
*hwc
= &event
->hw
;
5672 struct hlist_head
*head
;
5674 if (is_sampling_event(event
)) {
5675 hwc
->last_period
= hwc
->sample_period
;
5676 perf_swevent_set_period(event
);
5679 hwc
->state
= !(flags
& PERF_EF_START
);
5681 head
= find_swevent_head(swhash
, event
);
5684 * We can race with cpu hotplug code. Do not
5685 * WARN if the cpu just got unplugged.
5687 WARN_ON_ONCE(swhash
->online
);
5691 hlist_add_head_rcu(&event
->hlist_entry
, head
);
5696 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5698 hlist_del_rcu(&event
->hlist_entry
);
5701 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5703 event
->hw
.state
= 0;
5706 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5708 event
->hw
.state
= PERF_HES_STOPPED
;
5711 /* Deref the hlist from the update side */
5712 static inline struct swevent_hlist
*
5713 swevent_hlist_deref(struct swevent_htable
*swhash
)
5715 return rcu_dereference_protected(swhash
->swevent_hlist
,
5716 lockdep_is_held(&swhash
->hlist_mutex
));
5719 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5721 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5726 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5727 kfree_rcu(hlist
, rcu_head
);
5730 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5732 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5734 mutex_lock(&swhash
->hlist_mutex
);
5736 if (!--swhash
->hlist_refcount
)
5737 swevent_hlist_release(swhash
);
5739 mutex_unlock(&swhash
->hlist_mutex
);
5742 static void swevent_hlist_put(struct perf_event
*event
)
5746 for_each_possible_cpu(cpu
)
5747 swevent_hlist_put_cpu(event
, cpu
);
5750 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5752 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5755 mutex_lock(&swhash
->hlist_mutex
);
5757 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5758 struct swevent_hlist
*hlist
;
5760 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5765 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5767 swhash
->hlist_refcount
++;
5769 mutex_unlock(&swhash
->hlist_mutex
);
5774 static int swevent_hlist_get(struct perf_event
*event
)
5777 int cpu
, failed_cpu
;
5780 for_each_possible_cpu(cpu
) {
5781 err
= swevent_hlist_get_cpu(event
, cpu
);
5791 for_each_possible_cpu(cpu
) {
5792 if (cpu
== failed_cpu
)
5794 swevent_hlist_put_cpu(event
, cpu
);
5801 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5803 static void sw_perf_event_destroy(struct perf_event
*event
)
5805 u64 event_id
= event
->attr
.config
;
5807 WARN_ON(event
->parent
);
5809 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
5810 swevent_hlist_put(event
);
5813 static int perf_swevent_init(struct perf_event
*event
)
5815 u64 event_id
= event
->attr
.config
;
5817 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5821 * no branch sampling for software events
5823 if (has_branch_stack(event
))
5827 case PERF_COUNT_SW_CPU_CLOCK
:
5828 case PERF_COUNT_SW_TASK_CLOCK
:
5835 if (event_id
>= PERF_COUNT_SW_MAX
)
5838 if (!event
->parent
) {
5841 err
= swevent_hlist_get(event
);
5845 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
5846 event
->destroy
= sw_perf_event_destroy
;
5852 static int perf_swevent_event_idx(struct perf_event
*event
)
5857 static struct pmu perf_swevent
= {
5858 .task_ctx_nr
= perf_sw_context
,
5860 .event_init
= perf_swevent_init
,
5861 .add
= perf_swevent_add
,
5862 .del
= perf_swevent_del
,
5863 .start
= perf_swevent_start
,
5864 .stop
= perf_swevent_stop
,
5865 .read
= perf_swevent_read
,
5867 .event_idx
= perf_swevent_event_idx
,
5870 #ifdef CONFIG_EVENT_TRACING
5872 static int perf_tp_filter_match(struct perf_event
*event
,
5873 struct perf_sample_data
*data
)
5875 void *record
= data
->raw
->data
;
5877 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5882 static int perf_tp_event_match(struct perf_event
*event
,
5883 struct perf_sample_data
*data
,
5884 struct pt_regs
*regs
)
5886 if (event
->hw
.state
& PERF_HES_STOPPED
)
5889 * All tracepoints are from kernel-space.
5891 if (event
->attr
.exclude_kernel
)
5894 if (!perf_tp_filter_match(event
, data
))
5900 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5901 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
5902 struct task_struct
*task
)
5904 struct perf_sample_data data
;
5905 struct perf_event
*event
;
5907 struct perf_raw_record raw
= {
5912 perf_sample_data_init(&data
, addr
, 0);
5915 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5916 if (perf_tp_event_match(event
, &data
, regs
))
5917 perf_swevent_event(event
, count
, &data
, regs
);
5921 * If we got specified a target task, also iterate its context and
5922 * deliver this event there too.
5924 if (task
&& task
!= current
) {
5925 struct perf_event_context
*ctx
;
5926 struct trace_entry
*entry
= record
;
5929 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
5933 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5934 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5936 if (event
->attr
.config
!= entry
->type
)
5938 if (perf_tp_event_match(event
, &data
, regs
))
5939 perf_swevent_event(event
, count
, &data
, regs
);
5945 perf_swevent_put_recursion_context(rctx
);
5947 EXPORT_SYMBOL_GPL(perf_tp_event
);
5949 static void tp_perf_event_destroy(struct perf_event
*event
)
5951 perf_trace_destroy(event
);
5954 static int perf_tp_event_init(struct perf_event
*event
)
5958 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5962 * no branch sampling for tracepoint events
5964 if (has_branch_stack(event
))
5967 err
= perf_trace_init(event
);
5971 event
->destroy
= tp_perf_event_destroy
;
5976 static struct pmu perf_tracepoint
= {
5977 .task_ctx_nr
= perf_sw_context
,
5979 .event_init
= perf_tp_event_init
,
5980 .add
= perf_trace_add
,
5981 .del
= perf_trace_del
,
5982 .start
= perf_swevent_start
,
5983 .stop
= perf_swevent_stop
,
5984 .read
= perf_swevent_read
,
5986 .event_idx
= perf_swevent_event_idx
,
5989 static inline void perf_tp_register(void)
5991 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5994 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5999 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6002 filter_str
= strndup_user(arg
, PAGE_SIZE
);
6003 if (IS_ERR(filter_str
))
6004 return PTR_ERR(filter_str
);
6006 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
6012 static void perf_event_free_filter(struct perf_event
*event
)
6014 ftrace_profile_free_filter(event
);
6019 static inline void perf_tp_register(void)
6023 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6028 static void perf_event_free_filter(struct perf_event
*event
)
6032 #endif /* CONFIG_EVENT_TRACING */
6034 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6035 void perf_bp_event(struct perf_event
*bp
, void *data
)
6037 struct perf_sample_data sample
;
6038 struct pt_regs
*regs
= data
;
6040 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
6042 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
6043 perf_swevent_event(bp
, 1, &sample
, regs
);
6048 * hrtimer based swevent callback
6051 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
6053 enum hrtimer_restart ret
= HRTIMER_RESTART
;
6054 struct perf_sample_data data
;
6055 struct pt_regs
*regs
;
6056 struct perf_event
*event
;
6059 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
6061 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
6062 return HRTIMER_NORESTART
;
6064 event
->pmu
->read(event
);
6066 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
6067 regs
= get_irq_regs();
6069 if (regs
&& !perf_exclude_event(event
, regs
)) {
6070 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
6071 if (__perf_event_overflow(event
, 1, &data
, regs
))
6072 ret
= HRTIMER_NORESTART
;
6075 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
6076 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
6081 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
6083 struct hw_perf_event
*hwc
= &event
->hw
;
6086 if (!is_sampling_event(event
))
6089 period
= local64_read(&hwc
->period_left
);
6094 local64_set(&hwc
->period_left
, 0);
6096 period
= max_t(u64
, 10000, hwc
->sample_period
);
6098 __hrtimer_start_range_ns(&hwc
->hrtimer
,
6099 ns_to_ktime(period
), 0,
6100 HRTIMER_MODE_REL_PINNED
, 0);
6103 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
6105 struct hw_perf_event
*hwc
= &event
->hw
;
6107 if (is_sampling_event(event
)) {
6108 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
6109 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
6111 hrtimer_cancel(&hwc
->hrtimer
);
6115 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
6117 struct hw_perf_event
*hwc
= &event
->hw
;
6119 if (!is_sampling_event(event
))
6122 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
6123 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
6126 * Since hrtimers have a fixed rate, we can do a static freq->period
6127 * mapping and avoid the whole period adjust feedback stuff.
6129 if (event
->attr
.freq
) {
6130 long freq
= event
->attr
.sample_freq
;
6132 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
6133 hwc
->sample_period
= event
->attr
.sample_period
;
6134 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6135 hwc
->last_period
= hwc
->sample_period
;
6136 event
->attr
.freq
= 0;
6141 * Software event: cpu wall time clock
6144 static void cpu_clock_event_update(struct perf_event
*event
)
6149 now
= local_clock();
6150 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
6151 local64_add(now
- prev
, &event
->count
);
6154 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
6156 local64_set(&event
->hw
.prev_count
, local_clock());
6157 perf_swevent_start_hrtimer(event
);
6160 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
6162 perf_swevent_cancel_hrtimer(event
);
6163 cpu_clock_event_update(event
);
6166 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
6168 if (flags
& PERF_EF_START
)
6169 cpu_clock_event_start(event
, flags
);
6174 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
6176 cpu_clock_event_stop(event
, flags
);
6179 static void cpu_clock_event_read(struct perf_event
*event
)
6181 cpu_clock_event_update(event
);
6184 static int cpu_clock_event_init(struct perf_event
*event
)
6186 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6189 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
6193 * no branch sampling for software events
6195 if (has_branch_stack(event
))
6198 perf_swevent_init_hrtimer(event
);
6203 static struct pmu perf_cpu_clock
= {
6204 .task_ctx_nr
= perf_sw_context
,
6206 .event_init
= cpu_clock_event_init
,
6207 .add
= cpu_clock_event_add
,
6208 .del
= cpu_clock_event_del
,
6209 .start
= cpu_clock_event_start
,
6210 .stop
= cpu_clock_event_stop
,
6211 .read
= cpu_clock_event_read
,
6213 .event_idx
= perf_swevent_event_idx
,
6217 * Software event: task time clock
6220 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
6225 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
6227 local64_add(delta
, &event
->count
);
6230 static void task_clock_event_start(struct perf_event
*event
, int flags
)
6232 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
6233 perf_swevent_start_hrtimer(event
);
6236 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
6238 perf_swevent_cancel_hrtimer(event
);
6239 task_clock_event_update(event
, event
->ctx
->time
);
6242 static int task_clock_event_add(struct perf_event
*event
, int flags
)
6244 if (flags
& PERF_EF_START
)
6245 task_clock_event_start(event
, flags
);
6250 static void task_clock_event_del(struct perf_event
*event
, int flags
)
6252 task_clock_event_stop(event
, PERF_EF_UPDATE
);
6255 static void task_clock_event_read(struct perf_event
*event
)
6257 u64 now
= perf_clock();
6258 u64 delta
= now
- event
->ctx
->timestamp
;
6259 u64 time
= event
->ctx
->time
+ delta
;
6261 task_clock_event_update(event
, time
);
6264 static int task_clock_event_init(struct perf_event
*event
)
6266 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6269 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
6273 * no branch sampling for software events
6275 if (has_branch_stack(event
))
6278 perf_swevent_init_hrtimer(event
);
6283 static struct pmu perf_task_clock
= {
6284 .task_ctx_nr
= perf_sw_context
,
6286 .event_init
= task_clock_event_init
,
6287 .add
= task_clock_event_add
,
6288 .del
= task_clock_event_del
,
6289 .start
= task_clock_event_start
,
6290 .stop
= task_clock_event_stop
,
6291 .read
= task_clock_event_read
,
6293 .event_idx
= perf_swevent_event_idx
,
6296 static void perf_pmu_nop_void(struct pmu
*pmu
)
6300 static int perf_pmu_nop_int(struct pmu
*pmu
)
6305 static void perf_pmu_start_txn(struct pmu
*pmu
)
6307 perf_pmu_disable(pmu
);
6310 static int perf_pmu_commit_txn(struct pmu
*pmu
)
6312 perf_pmu_enable(pmu
);
6316 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
6318 perf_pmu_enable(pmu
);
6321 static int perf_event_idx_default(struct perf_event
*event
)
6323 return event
->hw
.idx
+ 1;
6327 * Ensures all contexts with the same task_ctx_nr have the same
6328 * pmu_cpu_context too.
6330 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
6337 list_for_each_entry(pmu
, &pmus
, entry
) {
6338 if (pmu
->task_ctx_nr
== ctxn
)
6339 return pmu
->pmu_cpu_context
;
6345 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
6349 for_each_possible_cpu(cpu
) {
6350 struct perf_cpu_context
*cpuctx
;
6352 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6354 if (cpuctx
->unique_pmu
== old_pmu
)
6355 cpuctx
->unique_pmu
= pmu
;
6359 static void free_pmu_context(struct pmu
*pmu
)
6363 mutex_lock(&pmus_lock
);
6365 * Like a real lame refcount.
6367 list_for_each_entry(i
, &pmus
, entry
) {
6368 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
6369 update_pmu_context(i
, pmu
);
6374 free_percpu(pmu
->pmu_cpu_context
);
6376 mutex_unlock(&pmus_lock
);
6378 static struct idr pmu_idr
;
6381 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
6383 struct pmu
*pmu
= dev_get_drvdata(dev
);
6385 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
6387 static DEVICE_ATTR_RO(type
);
6390 perf_event_mux_interval_ms_show(struct device
*dev
,
6391 struct device_attribute
*attr
,
6394 struct pmu
*pmu
= dev_get_drvdata(dev
);
6396 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
6400 perf_event_mux_interval_ms_store(struct device
*dev
,
6401 struct device_attribute
*attr
,
6402 const char *buf
, size_t count
)
6404 struct pmu
*pmu
= dev_get_drvdata(dev
);
6405 int timer
, cpu
, ret
;
6407 ret
= kstrtoint(buf
, 0, &timer
);
6414 /* same value, noting to do */
6415 if (timer
== pmu
->hrtimer_interval_ms
)
6418 pmu
->hrtimer_interval_ms
= timer
;
6420 /* update all cpuctx for this PMU */
6421 for_each_possible_cpu(cpu
) {
6422 struct perf_cpu_context
*cpuctx
;
6423 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6424 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
6426 if (hrtimer_active(&cpuctx
->hrtimer
))
6427 hrtimer_forward_now(&cpuctx
->hrtimer
, cpuctx
->hrtimer_interval
);
6432 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
6434 static struct attribute
*pmu_dev_attrs
[] = {
6435 &dev_attr_type
.attr
,
6436 &dev_attr_perf_event_mux_interval_ms
.attr
,
6439 ATTRIBUTE_GROUPS(pmu_dev
);
6441 static int pmu_bus_running
;
6442 static struct bus_type pmu_bus
= {
6443 .name
= "event_source",
6444 .dev_groups
= pmu_dev_groups
,
6447 static void pmu_dev_release(struct device
*dev
)
6452 static int pmu_dev_alloc(struct pmu
*pmu
)
6456 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
6460 pmu
->dev
->groups
= pmu
->attr_groups
;
6461 device_initialize(pmu
->dev
);
6462 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
6466 dev_set_drvdata(pmu
->dev
, pmu
);
6467 pmu
->dev
->bus
= &pmu_bus
;
6468 pmu
->dev
->release
= pmu_dev_release
;
6469 ret
= device_add(pmu
->dev
);
6477 put_device(pmu
->dev
);
6481 static struct lock_class_key cpuctx_mutex
;
6482 static struct lock_class_key cpuctx_lock
;
6484 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
6488 mutex_lock(&pmus_lock
);
6490 pmu
->pmu_disable_count
= alloc_percpu(int);
6491 if (!pmu
->pmu_disable_count
)
6500 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
6508 if (pmu_bus_running
) {
6509 ret
= pmu_dev_alloc(pmu
);
6515 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
6516 if (pmu
->pmu_cpu_context
)
6517 goto got_cpu_context
;
6520 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
6521 if (!pmu
->pmu_cpu_context
)
6524 for_each_possible_cpu(cpu
) {
6525 struct perf_cpu_context
*cpuctx
;
6527 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6528 __perf_event_init_context(&cpuctx
->ctx
);
6529 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
6530 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
6531 cpuctx
->ctx
.type
= cpu_context
;
6532 cpuctx
->ctx
.pmu
= pmu
;
6534 __perf_cpu_hrtimer_init(cpuctx
, cpu
);
6536 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
6537 cpuctx
->unique_pmu
= pmu
;
6541 if (!pmu
->start_txn
) {
6542 if (pmu
->pmu_enable
) {
6544 * If we have pmu_enable/pmu_disable calls, install
6545 * transaction stubs that use that to try and batch
6546 * hardware accesses.
6548 pmu
->start_txn
= perf_pmu_start_txn
;
6549 pmu
->commit_txn
= perf_pmu_commit_txn
;
6550 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
6552 pmu
->start_txn
= perf_pmu_nop_void
;
6553 pmu
->commit_txn
= perf_pmu_nop_int
;
6554 pmu
->cancel_txn
= perf_pmu_nop_void
;
6558 if (!pmu
->pmu_enable
) {
6559 pmu
->pmu_enable
= perf_pmu_nop_void
;
6560 pmu
->pmu_disable
= perf_pmu_nop_void
;
6563 if (!pmu
->event_idx
)
6564 pmu
->event_idx
= perf_event_idx_default
;
6566 list_add_rcu(&pmu
->entry
, &pmus
);
6569 mutex_unlock(&pmus_lock
);
6574 device_del(pmu
->dev
);
6575 put_device(pmu
->dev
);
6578 if (pmu
->type
>= PERF_TYPE_MAX
)
6579 idr_remove(&pmu_idr
, pmu
->type
);
6582 free_percpu(pmu
->pmu_disable_count
);
6586 void perf_pmu_unregister(struct pmu
*pmu
)
6588 mutex_lock(&pmus_lock
);
6589 list_del_rcu(&pmu
->entry
);
6590 mutex_unlock(&pmus_lock
);
6593 * We dereference the pmu list under both SRCU and regular RCU, so
6594 * synchronize against both of those.
6596 synchronize_srcu(&pmus_srcu
);
6599 free_percpu(pmu
->pmu_disable_count
);
6600 if (pmu
->type
>= PERF_TYPE_MAX
)
6601 idr_remove(&pmu_idr
, pmu
->type
);
6602 device_del(pmu
->dev
);
6603 put_device(pmu
->dev
);
6604 free_pmu_context(pmu
);
6607 struct pmu
*perf_init_event(struct perf_event
*event
)
6609 struct pmu
*pmu
= NULL
;
6613 idx
= srcu_read_lock(&pmus_srcu
);
6616 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
6620 ret
= pmu
->event_init(event
);
6626 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6628 ret
= pmu
->event_init(event
);
6632 if (ret
!= -ENOENT
) {
6637 pmu
= ERR_PTR(-ENOENT
);
6639 srcu_read_unlock(&pmus_srcu
, idx
);
6644 static void account_event_cpu(struct perf_event
*event
, int cpu
)
6649 if (has_branch_stack(event
)) {
6650 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
6651 atomic_inc(&per_cpu(perf_branch_stack_events
, cpu
));
6653 if (is_cgroup_event(event
))
6654 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
6657 static void account_event(struct perf_event
*event
)
6662 if (event
->attach_state
& PERF_ATTACH_TASK
)
6663 static_key_slow_inc(&perf_sched_events
.key
);
6664 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
6665 atomic_inc(&nr_mmap_events
);
6666 if (event
->attr
.comm
)
6667 atomic_inc(&nr_comm_events
);
6668 if (event
->attr
.task
)
6669 atomic_inc(&nr_task_events
);
6670 if (event
->attr
.freq
) {
6671 if (atomic_inc_return(&nr_freq_events
) == 1)
6672 tick_nohz_full_kick_all();
6674 if (has_branch_stack(event
))
6675 static_key_slow_inc(&perf_sched_events
.key
);
6676 if (is_cgroup_event(event
))
6677 static_key_slow_inc(&perf_sched_events
.key
);
6679 account_event_cpu(event
, event
->cpu
);
6683 * Allocate and initialize a event structure
6685 static struct perf_event
*
6686 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
6687 struct task_struct
*task
,
6688 struct perf_event
*group_leader
,
6689 struct perf_event
*parent_event
,
6690 perf_overflow_handler_t overflow_handler
,
6694 struct perf_event
*event
;
6695 struct hw_perf_event
*hwc
;
6698 if ((unsigned)cpu
>= nr_cpu_ids
) {
6699 if (!task
|| cpu
!= -1)
6700 return ERR_PTR(-EINVAL
);
6703 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
6705 return ERR_PTR(-ENOMEM
);
6708 * Single events are their own group leaders, with an
6709 * empty sibling list:
6712 group_leader
= event
;
6714 mutex_init(&event
->child_mutex
);
6715 INIT_LIST_HEAD(&event
->child_list
);
6717 INIT_LIST_HEAD(&event
->group_entry
);
6718 INIT_LIST_HEAD(&event
->event_entry
);
6719 INIT_LIST_HEAD(&event
->sibling_list
);
6720 INIT_LIST_HEAD(&event
->rb_entry
);
6721 INIT_LIST_HEAD(&event
->active_entry
);
6722 INIT_HLIST_NODE(&event
->hlist_entry
);
6725 init_waitqueue_head(&event
->waitq
);
6726 init_irq_work(&event
->pending
, perf_pending_event
);
6728 mutex_init(&event
->mmap_mutex
);
6730 atomic_long_set(&event
->refcount
, 1);
6732 event
->attr
= *attr
;
6733 event
->group_leader
= group_leader
;
6737 event
->parent
= parent_event
;
6739 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
6740 event
->id
= atomic64_inc_return(&perf_event_id
);
6742 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6745 event
->attach_state
= PERF_ATTACH_TASK
;
6747 if (attr
->type
== PERF_TYPE_TRACEPOINT
)
6748 event
->hw
.tp_target
= task
;
6749 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6751 * hw_breakpoint is a bit difficult here..
6753 else if (attr
->type
== PERF_TYPE_BREAKPOINT
)
6754 event
->hw
.bp_target
= task
;
6758 if (!overflow_handler
&& parent_event
) {
6759 overflow_handler
= parent_event
->overflow_handler
;
6760 context
= parent_event
->overflow_handler_context
;
6763 event
->overflow_handler
= overflow_handler
;
6764 event
->overflow_handler_context
= context
;
6766 perf_event__state_init(event
);
6771 hwc
->sample_period
= attr
->sample_period
;
6772 if (attr
->freq
&& attr
->sample_freq
)
6773 hwc
->sample_period
= 1;
6774 hwc
->last_period
= hwc
->sample_period
;
6776 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6779 * we currently do not support PERF_FORMAT_GROUP on inherited events
6781 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
6784 pmu
= perf_init_event(event
);
6787 else if (IS_ERR(pmu
)) {
6792 if (!event
->parent
) {
6793 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6794 err
= get_callchain_buffers();
6804 event
->destroy(event
);
6807 put_pid_ns(event
->ns
);
6810 return ERR_PTR(err
);
6813 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6814 struct perf_event_attr
*attr
)
6819 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6823 * zero the full structure, so that a short copy will be nice.
6825 memset(attr
, 0, sizeof(*attr
));
6827 ret
= get_user(size
, &uattr
->size
);
6831 if (size
> PAGE_SIZE
) /* silly large */
6834 if (!size
) /* abi compat */
6835 size
= PERF_ATTR_SIZE_VER0
;
6837 if (size
< PERF_ATTR_SIZE_VER0
)
6841 * If we're handed a bigger struct than we know of,
6842 * ensure all the unknown bits are 0 - i.e. new
6843 * user-space does not rely on any kernel feature
6844 * extensions we dont know about yet.
6846 if (size
> sizeof(*attr
)) {
6847 unsigned char __user
*addr
;
6848 unsigned char __user
*end
;
6851 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6852 end
= (void __user
*)uattr
+ size
;
6854 for (; addr
< end
; addr
++) {
6855 ret
= get_user(val
, addr
);
6861 size
= sizeof(*attr
);
6864 ret
= copy_from_user(attr
, uattr
, size
);
6868 /* disabled for now */
6872 if (attr
->__reserved_1
)
6875 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6878 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6881 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6882 u64 mask
= attr
->branch_sample_type
;
6884 /* only using defined bits */
6885 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
6888 /* at least one branch bit must be set */
6889 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
6892 /* propagate priv level, when not set for branch */
6893 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
6895 /* exclude_kernel checked on syscall entry */
6896 if (!attr
->exclude_kernel
)
6897 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
6899 if (!attr
->exclude_user
)
6900 mask
|= PERF_SAMPLE_BRANCH_USER
;
6902 if (!attr
->exclude_hv
)
6903 mask
|= PERF_SAMPLE_BRANCH_HV
;
6905 * adjust user setting (for HW filter setup)
6907 attr
->branch_sample_type
= mask
;
6909 /* privileged levels capture (kernel, hv): check permissions */
6910 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
6911 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6915 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
6916 ret
= perf_reg_validate(attr
->sample_regs_user
);
6921 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
6922 if (!arch_perf_have_user_stack_dump())
6926 * We have __u32 type for the size, but so far
6927 * we can only use __u16 as maximum due to the
6928 * __u16 sample size limit.
6930 if (attr
->sample_stack_user
>= USHRT_MAX
)
6932 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
6940 put_user(sizeof(*attr
), &uattr
->size
);
6946 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
6948 struct ring_buffer
*rb
= NULL
;
6954 /* don't allow circular references */
6955 if (event
== output_event
)
6959 * Don't allow cross-cpu buffers
6961 if (output_event
->cpu
!= event
->cpu
)
6965 * If its not a per-cpu rb, it must be the same task.
6967 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
6971 mutex_lock(&event
->mmap_mutex
);
6972 /* Can't redirect output if we've got an active mmap() */
6973 if (atomic_read(&event
->mmap_count
))
6977 /* get the rb we want to redirect to */
6978 rb
= ring_buffer_get(output_event
);
6983 ring_buffer_attach(event
, rb
);
6987 mutex_unlock(&event
->mmap_mutex
);
6994 * sys_perf_event_open - open a performance event, associate it to a task/cpu
6996 * @attr_uptr: event_id type attributes for monitoring/sampling
6999 * @group_fd: group leader event fd
7001 SYSCALL_DEFINE5(perf_event_open
,
7002 struct perf_event_attr __user
*, attr_uptr
,
7003 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
7005 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
7006 struct perf_event
*event
, *sibling
;
7007 struct perf_event_attr attr
;
7008 struct perf_event_context
*ctx
;
7009 struct file
*event_file
= NULL
;
7010 struct fd group
= {NULL
, 0};
7011 struct task_struct
*task
= NULL
;
7016 int f_flags
= O_RDWR
;
7018 /* for future expandability... */
7019 if (flags
& ~PERF_FLAG_ALL
)
7022 err
= perf_copy_attr(attr_uptr
, &attr
);
7026 if (!attr
.exclude_kernel
) {
7027 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
7032 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
7035 if (attr
.sample_period
& (1ULL << 63))
7040 * In cgroup mode, the pid argument is used to pass the fd
7041 * opened to the cgroup directory in cgroupfs. The cpu argument
7042 * designates the cpu on which to monitor threads from that
7045 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
7048 if (flags
& PERF_FLAG_FD_CLOEXEC
)
7049 f_flags
|= O_CLOEXEC
;
7051 event_fd
= get_unused_fd_flags(f_flags
);
7055 if (group_fd
!= -1) {
7056 err
= perf_fget_light(group_fd
, &group
);
7059 group_leader
= group
.file
->private_data
;
7060 if (flags
& PERF_FLAG_FD_OUTPUT
)
7061 output_event
= group_leader
;
7062 if (flags
& PERF_FLAG_FD_NO_GROUP
)
7063 group_leader
= NULL
;
7066 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
7067 task
= find_lively_task_by_vpid(pid
);
7069 err
= PTR_ERR(task
);
7076 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
7078 if (IS_ERR(event
)) {
7079 err
= PTR_ERR(event
);
7083 if (flags
& PERF_FLAG_PID_CGROUP
) {
7084 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
7086 __free_event(event
);
7091 account_event(event
);
7094 * Special case software events and allow them to be part of
7095 * any hardware group.
7100 (is_software_event(event
) != is_software_event(group_leader
))) {
7101 if (is_software_event(event
)) {
7103 * If event and group_leader are not both a software
7104 * event, and event is, then group leader is not.
7106 * Allow the addition of software events to !software
7107 * groups, this is safe because software events never
7110 pmu
= group_leader
->pmu
;
7111 } else if (is_software_event(group_leader
) &&
7112 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
7114 * In case the group is a pure software group, and we
7115 * try to add a hardware event, move the whole group to
7116 * the hardware context.
7123 * Get the target context (task or percpu):
7125 ctx
= find_get_context(pmu
, task
, event
->cpu
);
7132 put_task_struct(task
);
7137 * Look up the group leader (we will attach this event to it):
7143 * Do not allow a recursive hierarchy (this new sibling
7144 * becoming part of another group-sibling):
7146 if (group_leader
->group_leader
!= group_leader
)
7149 * Do not allow to attach to a group in a different
7150 * task or CPU context:
7153 if (group_leader
->ctx
->type
!= ctx
->type
)
7156 if (group_leader
->ctx
!= ctx
)
7161 * Only a group leader can be exclusive or pinned
7163 if (attr
.exclusive
|| attr
.pinned
)
7168 err
= perf_event_set_output(event
, output_event
);
7173 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
7175 if (IS_ERR(event_file
)) {
7176 err
= PTR_ERR(event_file
);
7181 struct perf_event_context
*gctx
= group_leader
->ctx
;
7183 mutex_lock(&gctx
->mutex
);
7184 perf_remove_from_context(group_leader
, false);
7187 * Removing from the context ends up with disabled
7188 * event. What we want here is event in the initial
7189 * startup state, ready to be add into new context.
7191 perf_event__state_init(group_leader
);
7192 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
7194 perf_remove_from_context(sibling
, false);
7195 perf_event__state_init(sibling
);
7198 mutex_unlock(&gctx
->mutex
);
7202 WARN_ON_ONCE(ctx
->parent_ctx
);
7203 mutex_lock(&ctx
->mutex
);
7207 perf_install_in_context(ctx
, group_leader
, event
->cpu
);
7209 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
7211 perf_install_in_context(ctx
, sibling
, event
->cpu
);
7216 perf_install_in_context(ctx
, event
, event
->cpu
);
7217 perf_unpin_context(ctx
);
7218 mutex_unlock(&ctx
->mutex
);
7222 event
->owner
= current
;
7224 mutex_lock(¤t
->perf_event_mutex
);
7225 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
7226 mutex_unlock(¤t
->perf_event_mutex
);
7229 * Precalculate sample_data sizes
7231 perf_event__header_size(event
);
7232 perf_event__id_header_size(event
);
7235 * Drop the reference on the group_event after placing the
7236 * new event on the sibling_list. This ensures destruction
7237 * of the group leader will find the pointer to itself in
7238 * perf_group_detach().
7241 fd_install(event_fd
, event_file
);
7245 perf_unpin_context(ctx
);
7252 put_task_struct(task
);
7256 put_unused_fd(event_fd
);
7261 * perf_event_create_kernel_counter
7263 * @attr: attributes of the counter to create
7264 * @cpu: cpu in which the counter is bound
7265 * @task: task to profile (NULL for percpu)
7268 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
7269 struct task_struct
*task
,
7270 perf_overflow_handler_t overflow_handler
,
7273 struct perf_event_context
*ctx
;
7274 struct perf_event
*event
;
7278 * Get the target context (task or percpu):
7281 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
7282 overflow_handler
, context
);
7283 if (IS_ERR(event
)) {
7284 err
= PTR_ERR(event
);
7288 account_event(event
);
7290 ctx
= find_get_context(event
->pmu
, task
, cpu
);
7296 WARN_ON_ONCE(ctx
->parent_ctx
);
7297 mutex_lock(&ctx
->mutex
);
7298 perf_install_in_context(ctx
, event
, cpu
);
7299 perf_unpin_context(ctx
);
7300 mutex_unlock(&ctx
->mutex
);
7307 return ERR_PTR(err
);
7309 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
7311 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
7313 struct perf_event_context
*src_ctx
;
7314 struct perf_event_context
*dst_ctx
;
7315 struct perf_event
*event
, *tmp
;
7318 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
7319 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
7321 mutex_lock(&src_ctx
->mutex
);
7322 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
7324 perf_remove_from_context(event
, false);
7325 unaccount_event_cpu(event
, src_cpu
);
7327 list_add(&event
->migrate_entry
, &events
);
7329 mutex_unlock(&src_ctx
->mutex
);
7333 mutex_lock(&dst_ctx
->mutex
);
7334 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
7335 list_del(&event
->migrate_entry
);
7336 if (event
->state
>= PERF_EVENT_STATE_OFF
)
7337 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7338 account_event_cpu(event
, dst_cpu
);
7339 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
7342 mutex_unlock(&dst_ctx
->mutex
);
7344 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
7346 static void sync_child_event(struct perf_event
*child_event
,
7347 struct task_struct
*child
)
7349 struct perf_event
*parent_event
= child_event
->parent
;
7352 if (child_event
->attr
.inherit_stat
)
7353 perf_event_read_event(child_event
, child
);
7355 child_val
= perf_event_count(child_event
);
7358 * Add back the child's count to the parent's count:
7360 atomic64_add(child_val
, &parent_event
->child_count
);
7361 atomic64_add(child_event
->total_time_enabled
,
7362 &parent_event
->child_total_time_enabled
);
7363 atomic64_add(child_event
->total_time_running
,
7364 &parent_event
->child_total_time_running
);
7367 * Remove this event from the parent's list
7369 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7370 mutex_lock(&parent_event
->child_mutex
);
7371 list_del_init(&child_event
->child_list
);
7372 mutex_unlock(&parent_event
->child_mutex
);
7375 * Release the parent event, if this was the last
7378 put_event(parent_event
);
7382 __perf_event_exit_task(struct perf_event
*child_event
,
7383 struct perf_event_context
*child_ctx
,
7384 struct task_struct
*child
)
7386 perf_remove_from_context(child_event
, !!child_event
->parent
);
7389 * It can happen that the parent exits first, and has events
7390 * that are still around due to the child reference. These
7391 * events need to be zapped.
7393 if (child_event
->parent
) {
7394 sync_child_event(child_event
, child
);
7395 free_event(child_event
);
7399 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
7401 struct perf_event
*child_event
, *tmp
;
7402 struct perf_event_context
*child_ctx
;
7403 unsigned long flags
;
7405 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
7406 perf_event_task(child
, NULL
, 0);
7410 local_irq_save(flags
);
7412 * We can't reschedule here because interrupts are disabled,
7413 * and either child is current or it is a task that can't be
7414 * scheduled, so we are now safe from rescheduling changing
7417 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
7420 * Take the context lock here so that if find_get_context is
7421 * reading child->perf_event_ctxp, we wait until it has
7422 * incremented the context's refcount before we do put_ctx below.
7424 raw_spin_lock(&child_ctx
->lock
);
7425 task_ctx_sched_out(child_ctx
);
7426 child
->perf_event_ctxp
[ctxn
] = NULL
;
7428 * If this context is a clone; unclone it so it can't get
7429 * swapped to another process while we're removing all
7430 * the events from it.
7432 unclone_ctx(child_ctx
);
7433 update_context_time(child_ctx
);
7434 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
7437 * Report the task dead after unscheduling the events so that we
7438 * won't get any samples after PERF_RECORD_EXIT. We can however still
7439 * get a few PERF_RECORD_READ events.
7441 perf_event_task(child
, child_ctx
, 0);
7444 * We can recurse on the same lock type through:
7446 * __perf_event_exit_task()
7447 * sync_child_event()
7449 * mutex_lock(&ctx->mutex)
7451 * But since its the parent context it won't be the same instance.
7453 mutex_lock(&child_ctx
->mutex
);
7456 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
7458 __perf_event_exit_task(child_event
, child_ctx
, child
);
7460 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
7462 __perf_event_exit_task(child_event
, child_ctx
, child
);
7465 * If the last event was a group event, it will have appended all
7466 * its siblings to the list, but we obtained 'tmp' before that which
7467 * will still point to the list head terminating the iteration.
7469 if (!list_empty(&child_ctx
->pinned_groups
) ||
7470 !list_empty(&child_ctx
->flexible_groups
))
7473 mutex_unlock(&child_ctx
->mutex
);
7479 * When a child task exits, feed back event values to parent events.
7481 void perf_event_exit_task(struct task_struct
*child
)
7483 struct perf_event
*event
, *tmp
;
7486 mutex_lock(&child
->perf_event_mutex
);
7487 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
7489 list_del_init(&event
->owner_entry
);
7492 * Ensure the list deletion is visible before we clear
7493 * the owner, closes a race against perf_release() where
7494 * we need to serialize on the owner->perf_event_mutex.
7497 event
->owner
= NULL
;
7499 mutex_unlock(&child
->perf_event_mutex
);
7501 for_each_task_context_nr(ctxn
)
7502 perf_event_exit_task_context(child
, ctxn
);
7505 static void perf_free_event(struct perf_event
*event
,
7506 struct perf_event_context
*ctx
)
7508 struct perf_event
*parent
= event
->parent
;
7510 if (WARN_ON_ONCE(!parent
))
7513 mutex_lock(&parent
->child_mutex
);
7514 list_del_init(&event
->child_list
);
7515 mutex_unlock(&parent
->child_mutex
);
7519 perf_group_detach(event
);
7520 list_del_event(event
, ctx
);
7525 * free an unexposed, unused context as created by inheritance by
7526 * perf_event_init_task below, used by fork() in case of fail.
7528 void perf_event_free_task(struct task_struct
*task
)
7530 struct perf_event_context
*ctx
;
7531 struct perf_event
*event
, *tmp
;
7534 for_each_task_context_nr(ctxn
) {
7535 ctx
= task
->perf_event_ctxp
[ctxn
];
7539 mutex_lock(&ctx
->mutex
);
7541 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
7543 perf_free_event(event
, ctx
);
7545 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
7547 perf_free_event(event
, ctx
);
7549 if (!list_empty(&ctx
->pinned_groups
) ||
7550 !list_empty(&ctx
->flexible_groups
))
7553 mutex_unlock(&ctx
->mutex
);
7559 void perf_event_delayed_put(struct task_struct
*task
)
7563 for_each_task_context_nr(ctxn
)
7564 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
7568 * inherit a event from parent task to child task:
7570 static struct perf_event
*
7571 inherit_event(struct perf_event
*parent_event
,
7572 struct task_struct
*parent
,
7573 struct perf_event_context
*parent_ctx
,
7574 struct task_struct
*child
,
7575 struct perf_event
*group_leader
,
7576 struct perf_event_context
*child_ctx
)
7578 struct perf_event
*child_event
;
7579 unsigned long flags
;
7582 * Instead of creating recursive hierarchies of events,
7583 * we link inherited events back to the original parent,
7584 * which has a filp for sure, which we use as the reference
7587 if (parent_event
->parent
)
7588 parent_event
= parent_event
->parent
;
7590 child_event
= perf_event_alloc(&parent_event
->attr
,
7593 group_leader
, parent_event
,
7595 if (IS_ERR(child_event
))
7598 if (!atomic_long_inc_not_zero(&parent_event
->refcount
)) {
7599 free_event(child_event
);
7606 * Make the child state follow the state of the parent event,
7607 * not its attr.disabled bit. We hold the parent's mutex,
7608 * so we won't race with perf_event_{en, dis}able_family.
7610 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
7611 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
7613 child_event
->state
= PERF_EVENT_STATE_OFF
;
7615 if (parent_event
->attr
.freq
) {
7616 u64 sample_period
= parent_event
->hw
.sample_period
;
7617 struct hw_perf_event
*hwc
= &child_event
->hw
;
7619 hwc
->sample_period
= sample_period
;
7620 hwc
->last_period
= sample_period
;
7622 local64_set(&hwc
->period_left
, sample_period
);
7625 child_event
->ctx
= child_ctx
;
7626 child_event
->overflow_handler
= parent_event
->overflow_handler
;
7627 child_event
->overflow_handler_context
7628 = parent_event
->overflow_handler_context
;
7631 * Precalculate sample_data sizes
7633 perf_event__header_size(child_event
);
7634 perf_event__id_header_size(child_event
);
7637 * Link it up in the child's context:
7639 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
7640 add_event_to_ctx(child_event
, child_ctx
);
7641 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
7644 * Link this into the parent event's child list
7646 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7647 mutex_lock(&parent_event
->child_mutex
);
7648 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
7649 mutex_unlock(&parent_event
->child_mutex
);
7654 static int inherit_group(struct perf_event
*parent_event
,
7655 struct task_struct
*parent
,
7656 struct perf_event_context
*parent_ctx
,
7657 struct task_struct
*child
,
7658 struct perf_event_context
*child_ctx
)
7660 struct perf_event
*leader
;
7661 struct perf_event
*sub
;
7662 struct perf_event
*child_ctr
;
7664 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
7665 child
, NULL
, child_ctx
);
7667 return PTR_ERR(leader
);
7668 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
7669 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
7670 child
, leader
, child_ctx
);
7671 if (IS_ERR(child_ctr
))
7672 return PTR_ERR(child_ctr
);
7678 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
7679 struct perf_event_context
*parent_ctx
,
7680 struct task_struct
*child
, int ctxn
,
7684 struct perf_event_context
*child_ctx
;
7686 if (!event
->attr
.inherit
) {
7691 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7694 * This is executed from the parent task context, so
7695 * inherit events that have been marked for cloning.
7696 * First allocate and initialize a context for the
7700 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
7704 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
7707 ret
= inherit_group(event
, parent
, parent_ctx
,
7717 * Initialize the perf_event context in task_struct
7719 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
7721 struct perf_event_context
*child_ctx
, *parent_ctx
;
7722 struct perf_event_context
*cloned_ctx
;
7723 struct perf_event
*event
;
7724 struct task_struct
*parent
= current
;
7725 int inherited_all
= 1;
7726 unsigned long flags
;
7729 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
7733 * If the parent's context is a clone, pin it so it won't get
7736 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
7741 * No need to check if parent_ctx != NULL here; since we saw
7742 * it non-NULL earlier, the only reason for it to become NULL
7743 * is if we exit, and since we're currently in the middle of
7744 * a fork we can't be exiting at the same time.
7748 * Lock the parent list. No need to lock the child - not PID
7749 * hashed yet and not running, so nobody can access it.
7751 mutex_lock(&parent_ctx
->mutex
);
7754 * We dont have to disable NMIs - we are only looking at
7755 * the list, not manipulating it:
7757 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
7758 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7759 child
, ctxn
, &inherited_all
);
7765 * We can't hold ctx->lock when iterating the ->flexible_group list due
7766 * to allocations, but we need to prevent rotation because
7767 * rotate_ctx() will change the list from interrupt context.
7769 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7770 parent_ctx
->rotate_disable
= 1;
7771 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7773 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
7774 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7775 child
, ctxn
, &inherited_all
);
7780 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7781 parent_ctx
->rotate_disable
= 0;
7783 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7785 if (child_ctx
&& inherited_all
) {
7787 * Mark the child context as a clone of the parent
7788 * context, or of whatever the parent is a clone of.
7790 * Note that if the parent is a clone, the holding of
7791 * parent_ctx->lock avoids it from being uncloned.
7793 cloned_ctx
= parent_ctx
->parent_ctx
;
7795 child_ctx
->parent_ctx
= cloned_ctx
;
7796 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
7798 child_ctx
->parent_ctx
= parent_ctx
;
7799 child_ctx
->parent_gen
= parent_ctx
->generation
;
7801 get_ctx(child_ctx
->parent_ctx
);
7804 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7805 mutex_unlock(&parent_ctx
->mutex
);
7807 perf_unpin_context(parent_ctx
);
7808 put_ctx(parent_ctx
);
7814 * Initialize the perf_event context in task_struct
7816 int perf_event_init_task(struct task_struct
*child
)
7820 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7821 mutex_init(&child
->perf_event_mutex
);
7822 INIT_LIST_HEAD(&child
->perf_event_list
);
7824 for_each_task_context_nr(ctxn
) {
7825 ret
= perf_event_init_context(child
, ctxn
);
7833 static void __init
perf_event_init_all_cpus(void)
7835 struct swevent_htable
*swhash
;
7838 for_each_possible_cpu(cpu
) {
7839 swhash
= &per_cpu(swevent_htable
, cpu
);
7840 mutex_init(&swhash
->hlist_mutex
);
7841 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7845 static void perf_event_init_cpu(int cpu
)
7847 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7849 mutex_lock(&swhash
->hlist_mutex
);
7850 swhash
->online
= true;
7851 if (swhash
->hlist_refcount
> 0) {
7852 struct swevent_hlist
*hlist
;
7854 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7856 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7858 mutex_unlock(&swhash
->hlist_mutex
);
7861 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7862 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7864 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7866 WARN_ON(!irqs_disabled());
7868 list_del_init(&cpuctx
->rotation_list
);
7871 static void __perf_event_exit_context(void *__info
)
7873 struct remove_event re
= { .detach_group
= false };
7874 struct perf_event_context
*ctx
= __info
;
7876 perf_pmu_rotate_stop(ctx
->pmu
);
7879 list_for_each_entry_rcu(re
.event
, &ctx
->event_list
, event_entry
)
7880 __perf_remove_from_context(&re
);
7884 static void perf_event_exit_cpu_context(int cpu
)
7886 struct perf_event_context
*ctx
;
7890 idx
= srcu_read_lock(&pmus_srcu
);
7891 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7892 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
7894 mutex_lock(&ctx
->mutex
);
7895 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
7896 mutex_unlock(&ctx
->mutex
);
7898 srcu_read_unlock(&pmus_srcu
, idx
);
7901 static void perf_event_exit_cpu(int cpu
)
7903 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7905 perf_event_exit_cpu_context(cpu
);
7907 mutex_lock(&swhash
->hlist_mutex
);
7908 swhash
->online
= false;
7909 swevent_hlist_release(swhash
);
7910 mutex_unlock(&swhash
->hlist_mutex
);
7913 static inline void perf_event_exit_cpu(int cpu
) { }
7917 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
7921 for_each_online_cpu(cpu
)
7922 perf_event_exit_cpu(cpu
);
7928 * Run the perf reboot notifier at the very last possible moment so that
7929 * the generic watchdog code runs as long as possible.
7931 static struct notifier_block perf_reboot_notifier
= {
7932 .notifier_call
= perf_reboot
,
7933 .priority
= INT_MIN
,
7937 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
7939 unsigned int cpu
= (long)hcpu
;
7941 switch (action
& ~CPU_TASKS_FROZEN
) {
7943 case CPU_UP_PREPARE
:
7944 case CPU_DOWN_FAILED
:
7945 perf_event_init_cpu(cpu
);
7948 case CPU_UP_CANCELED
:
7949 case CPU_DOWN_PREPARE
:
7950 perf_event_exit_cpu(cpu
);
7959 void __init
perf_event_init(void)
7965 perf_event_init_all_cpus();
7966 init_srcu_struct(&pmus_srcu
);
7967 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
7968 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
7969 perf_pmu_register(&perf_task_clock
, NULL
, -1);
7971 perf_cpu_notifier(perf_cpu_notify
);
7972 register_reboot_notifier(&perf_reboot_notifier
);
7974 ret
= init_hw_breakpoint();
7975 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
7977 /* do not patch jump label more than once per second */
7978 jump_label_rate_limit(&perf_sched_events
, HZ
);
7981 * Build time assertion that we keep the data_head at the intended
7982 * location. IOW, validation we got the __reserved[] size right.
7984 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
7988 static int __init
perf_event_sysfs_init(void)
7993 mutex_lock(&pmus_lock
);
7995 ret
= bus_register(&pmu_bus
);
7999 list_for_each_entry(pmu
, &pmus
, entry
) {
8000 if (!pmu
->name
|| pmu
->type
< 0)
8003 ret
= pmu_dev_alloc(pmu
);
8004 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
8006 pmu_bus_running
= 1;
8010 mutex_unlock(&pmus_lock
);
8014 device_initcall(perf_event_sysfs_init
);
8016 #ifdef CONFIG_CGROUP_PERF
8017 static struct cgroup_subsys_state
*
8018 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
8020 struct perf_cgroup
*jc
;
8022 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
8024 return ERR_PTR(-ENOMEM
);
8026 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
8029 return ERR_PTR(-ENOMEM
);
8035 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
8037 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
8039 free_percpu(jc
->info
);
8043 static int __perf_cgroup_move(void *info
)
8045 struct task_struct
*task
= info
;
8046 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
8050 static void perf_cgroup_attach(struct cgroup_subsys_state
*css
,
8051 struct cgroup_taskset
*tset
)
8053 struct task_struct
*task
;
8055 cgroup_taskset_for_each(task
, tset
)
8056 task_function_call(task
, __perf_cgroup_move
, task
);
8059 static void perf_cgroup_exit(struct cgroup_subsys_state
*css
,
8060 struct cgroup_subsys_state
*old_css
,
8061 struct task_struct
*task
)
8064 * cgroup_exit() is called in the copy_process() failure path.
8065 * Ignore this case since the task hasn't ran yet, this avoids
8066 * trying to poke a half freed task state from generic code.
8068 if (!(task
->flags
& PF_EXITING
))
8071 task_function_call(task
, __perf_cgroup_move
, task
);
8074 struct cgroup_subsys perf_event_cgrp_subsys
= {
8075 .css_alloc
= perf_cgroup_css_alloc
,
8076 .css_free
= perf_cgroup_css_free
,
8077 .exit
= perf_cgroup_exit
,
8078 .attach
= perf_cgroup_attach
,
8080 #endif /* CONFIG_CGROUP_PERF */