2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2009 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/sysfs.h>
22 #include <linux/dcache.h>
23 #include <linux/percpu.h>
24 #include <linux/ptrace.h>
25 #include <linux/reboot.h>
26 #include <linux/vmstat.h>
27 #include <linux/device.h>
28 #include <linux/vmalloc.h>
29 #include <linux/hardirq.h>
30 #include <linux/rculist.h>
31 #include <linux/uaccess.h>
32 #include <linux/syscalls.h>
33 #include <linux/anon_inodes.h>
34 #include <linux/kernel_stat.h>
35 #include <linux/perf_event.h>
36 #include <linux/ftrace_event.h>
37 #include <linux/hw_breakpoint.h>
39 #include <asm/irq_regs.h>
41 struct remote_function_call
{
42 struct task_struct
*p
;
43 int (*func
)(void *info
);
48 static void remote_function(void *data
)
50 struct remote_function_call
*tfc
= data
;
51 struct task_struct
*p
= tfc
->p
;
55 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
59 tfc
->ret
= tfc
->func(tfc
->info
);
63 * task_function_call - call a function on the cpu on which a task runs
64 * @p: the task to evaluate
65 * @func: the function to be called
66 * @info: the function call argument
68 * Calls the function @func when the task is currently running. This might
69 * be on the current CPU, which just calls the function directly
71 * returns: @func return value, or
72 * -ESRCH - when the process isn't running
73 * -EAGAIN - when the process moved away
76 task_function_call(struct task_struct
*p
, int (*func
) (void *info
), void *info
)
78 struct remote_function_call data
= {
82 .ret
= -ESRCH
, /* No such (running) process */
86 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
92 * cpu_function_call - call a function on the cpu
93 * @func: the function to be called
94 * @info: the function call argument
96 * Calls the function @func on the remote cpu.
98 * returns: @func return value or -ENXIO when the cpu is offline
100 static int cpu_function_call(int cpu
, int (*func
) (void *info
), void *info
)
102 struct remote_function_call data
= {
106 .ret
= -ENXIO
, /* No such CPU */
109 smp_call_function_single(cpu
, remote_function
, &data
, 1);
114 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
115 PERF_FLAG_FD_OUTPUT |\
116 PERF_FLAG_PID_CGROUP)
119 EVENT_FLEXIBLE
= 0x1,
121 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
125 * perf_sched_events : >0 events exist
126 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
128 atomic_t perf_sched_events __read_mostly
;
129 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
131 static atomic_t nr_mmap_events __read_mostly
;
132 static atomic_t nr_comm_events __read_mostly
;
133 static atomic_t nr_task_events __read_mostly
;
135 static LIST_HEAD(pmus
);
136 static DEFINE_MUTEX(pmus_lock
);
137 static struct srcu_struct pmus_srcu
;
140 * perf event paranoia level:
141 * -1 - not paranoid at all
142 * 0 - disallow raw tracepoint access for unpriv
143 * 1 - disallow cpu events for unpriv
144 * 2 - disallow kernel profiling for unpriv
146 int sysctl_perf_event_paranoid __read_mostly
= 1;
148 int sysctl_perf_event_mlock __read_mostly
= 512; /* 'free' kb per user */
151 * max perf event sample rate
153 #define DEFAULT_MAX_SAMPLE_RATE 100000
154 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
155 static int max_samples_per_tick __read_mostly
=
156 DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
158 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
159 void __user
*buffer
, size_t *lenp
,
162 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
167 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
172 static atomic64_t perf_event_id
;
174 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
175 enum event_type_t event_type
);
177 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
178 enum event_type_t event_type
,
179 struct task_struct
*task
);
181 static void update_context_time(struct perf_event_context
*ctx
);
182 static u64
perf_event_time(struct perf_event
*event
);
184 void __weak
perf_event_print_debug(void) { }
186 extern __weak
const char *perf_pmu_name(void)
191 static inline u64
perf_clock(void)
193 return local_clock();
196 static inline struct perf_cpu_context
*
197 __get_cpu_context(struct perf_event_context
*ctx
)
199 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
202 #ifdef CONFIG_CGROUP_PERF
205 * Must ensure cgroup is pinned (css_get) before calling
206 * this function. In other words, we cannot call this function
207 * if there is no cgroup event for the current CPU context.
209 static inline struct perf_cgroup
*
210 perf_cgroup_from_task(struct task_struct
*task
)
212 return container_of(task_subsys_state(task
, perf_subsys_id
),
213 struct perf_cgroup
, css
);
217 perf_cgroup_match(struct perf_event
*event
)
219 struct perf_event_context
*ctx
= event
->ctx
;
220 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
222 return !event
->cgrp
|| event
->cgrp
== cpuctx
->cgrp
;
225 static inline void perf_get_cgroup(struct perf_event
*event
)
227 css_get(&event
->cgrp
->css
);
230 static inline void perf_put_cgroup(struct perf_event
*event
)
232 css_put(&event
->cgrp
->css
);
235 static inline void perf_detach_cgroup(struct perf_event
*event
)
237 perf_put_cgroup(event
);
241 static inline int is_cgroup_event(struct perf_event
*event
)
243 return event
->cgrp
!= NULL
;
246 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
248 struct perf_cgroup_info
*t
;
250 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
254 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
256 struct perf_cgroup_info
*info
;
261 info
= this_cpu_ptr(cgrp
->info
);
263 info
->time
+= now
- info
->timestamp
;
264 info
->timestamp
= now
;
267 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
269 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
271 __update_cgrp_time(cgrp_out
);
274 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
276 struct perf_cgroup
*cgrp
;
279 * ensure we access cgroup data only when needed and
280 * when we know the cgroup is pinned (css_get)
282 if (!is_cgroup_event(event
))
285 cgrp
= perf_cgroup_from_task(current
);
287 * Do not update time when cgroup is not active
289 if (cgrp
== event
->cgrp
)
290 __update_cgrp_time(event
->cgrp
);
294 perf_cgroup_set_timestamp(struct task_struct
*task
,
295 struct perf_event_context
*ctx
)
297 struct perf_cgroup
*cgrp
;
298 struct perf_cgroup_info
*info
;
301 * ctx->lock held by caller
302 * ensure we do not access cgroup data
303 * unless we have the cgroup pinned (css_get)
305 if (!task
|| !ctx
->nr_cgroups
)
308 cgrp
= perf_cgroup_from_task(task
);
309 info
= this_cpu_ptr(cgrp
->info
);
310 info
->timestamp
= ctx
->timestamp
;
313 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
314 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
317 * reschedule events based on the cgroup constraint of task.
319 * mode SWOUT : schedule out everything
320 * mode SWIN : schedule in based on cgroup for next
322 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
324 struct perf_cpu_context
*cpuctx
;
329 * disable interrupts to avoid geting nr_cgroup
330 * changes via __perf_event_disable(). Also
333 local_irq_save(flags
);
336 * we reschedule only in the presence of cgroup
337 * constrained events.
341 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
343 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
345 perf_pmu_disable(cpuctx
->ctx
.pmu
);
348 * perf_cgroup_events says at least one
349 * context on this CPU has cgroup events.
351 * ctx->nr_cgroups reports the number of cgroup
352 * events for a context.
354 if (cpuctx
->ctx
.nr_cgroups
> 0) {
356 if (mode
& PERF_CGROUP_SWOUT
) {
357 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
359 * must not be done before ctxswout due
360 * to event_filter_match() in event_sched_out()
365 if (mode
& PERF_CGROUP_SWIN
) {
366 /* set cgrp before ctxsw in to
367 * allow event_filter_match() to not
368 * have to pass task around
370 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
371 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
375 perf_pmu_enable(cpuctx
->ctx
.pmu
);
380 local_irq_restore(flags
);
383 static inline void perf_cgroup_sched_out(struct task_struct
*task
)
385 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
388 static inline void perf_cgroup_sched_in(struct task_struct
*task
)
390 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
393 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
394 struct perf_event_attr
*attr
,
395 struct perf_event
*group_leader
)
397 struct perf_cgroup
*cgrp
;
398 struct cgroup_subsys_state
*css
;
400 int ret
= 0, fput_needed
;
402 file
= fget_light(fd
, &fput_needed
);
406 css
= cgroup_css_from_dir(file
, perf_subsys_id
);
412 cgrp
= container_of(css
, struct perf_cgroup
, css
);
415 /* must be done before we fput() the file */
416 perf_get_cgroup(event
);
419 * all events in a group must monitor
420 * the same cgroup because a task belongs
421 * to only one perf cgroup at a time
423 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
424 perf_detach_cgroup(event
);
428 fput_light(file
, fput_needed
);
433 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
435 struct perf_cgroup_info
*t
;
436 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
437 event
->shadow_ctx_time
= now
- t
->timestamp
;
441 perf_cgroup_defer_enabled(struct perf_event
*event
)
444 * when the current task's perf cgroup does not match
445 * the event's, we need to remember to call the
446 * perf_mark_enable() function the first time a task with
447 * a matching perf cgroup is scheduled in.
449 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
450 event
->cgrp_defer_enabled
= 1;
454 perf_cgroup_mark_enabled(struct perf_event
*event
,
455 struct perf_event_context
*ctx
)
457 struct perf_event
*sub
;
458 u64 tstamp
= perf_event_time(event
);
460 if (!event
->cgrp_defer_enabled
)
463 event
->cgrp_defer_enabled
= 0;
465 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
466 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
467 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
468 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
469 sub
->cgrp_defer_enabled
= 0;
473 #else /* !CONFIG_CGROUP_PERF */
476 perf_cgroup_match(struct perf_event
*event
)
481 static inline void perf_detach_cgroup(struct perf_event
*event
)
484 static inline int is_cgroup_event(struct perf_event
*event
)
489 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
494 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
498 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
502 static inline void perf_cgroup_sched_out(struct task_struct
*task
)
506 static inline void perf_cgroup_sched_in(struct task_struct
*task
)
510 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
511 struct perf_event_attr
*attr
,
512 struct perf_event
*group_leader
)
518 perf_cgroup_set_timestamp(struct task_struct
*task
,
519 struct perf_event_context
*ctx
)
524 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
529 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
533 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
539 perf_cgroup_defer_enabled(struct perf_event
*event
)
544 perf_cgroup_mark_enabled(struct perf_event
*event
,
545 struct perf_event_context
*ctx
)
550 void perf_pmu_disable(struct pmu
*pmu
)
552 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
554 pmu
->pmu_disable(pmu
);
557 void perf_pmu_enable(struct pmu
*pmu
)
559 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
561 pmu
->pmu_enable(pmu
);
564 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
567 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
568 * because they're strictly cpu affine and rotate_start is called with IRQs
569 * disabled, while rotate_context is called from IRQ context.
571 static void perf_pmu_rotate_start(struct pmu
*pmu
)
573 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
574 struct list_head
*head
= &__get_cpu_var(rotation_list
);
576 WARN_ON(!irqs_disabled());
578 if (list_empty(&cpuctx
->rotation_list
))
579 list_add(&cpuctx
->rotation_list
, head
);
582 static void get_ctx(struct perf_event_context
*ctx
)
584 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
587 static void free_ctx(struct rcu_head
*head
)
589 struct perf_event_context
*ctx
;
591 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
595 static void put_ctx(struct perf_event_context
*ctx
)
597 if (atomic_dec_and_test(&ctx
->refcount
)) {
599 put_ctx(ctx
->parent_ctx
);
601 put_task_struct(ctx
->task
);
602 call_rcu(&ctx
->rcu_head
, free_ctx
);
606 static void unclone_ctx(struct perf_event_context
*ctx
)
608 if (ctx
->parent_ctx
) {
609 put_ctx(ctx
->parent_ctx
);
610 ctx
->parent_ctx
= NULL
;
614 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
617 * only top level events have the pid namespace they were created in
620 event
= event
->parent
;
622 return task_tgid_nr_ns(p
, event
->ns
);
625 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
628 * only top level events have the pid namespace they were created in
631 event
= event
->parent
;
633 return task_pid_nr_ns(p
, event
->ns
);
637 * If we inherit events we want to return the parent event id
640 static u64
primary_event_id(struct perf_event
*event
)
645 id
= event
->parent
->id
;
651 * Get the perf_event_context for a task and lock it.
652 * This has to cope with with the fact that until it is locked,
653 * the context could get moved to another task.
655 static struct perf_event_context
*
656 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
658 struct perf_event_context
*ctx
;
662 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
665 * If this context is a clone of another, it might
666 * get swapped for another underneath us by
667 * perf_event_task_sched_out, though the
668 * rcu_read_lock() protects us from any context
669 * getting freed. Lock the context and check if it
670 * got swapped before we could get the lock, and retry
671 * if so. If we locked the right context, then it
672 * can't get swapped on us any more.
674 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
675 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
676 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
680 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
681 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
690 * Get the context for a task and increment its pin_count so it
691 * can't get swapped to another task. This also increments its
692 * reference count so that the context can't get freed.
694 static struct perf_event_context
*
695 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
697 struct perf_event_context
*ctx
;
700 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
703 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
708 static void perf_unpin_context(struct perf_event_context
*ctx
)
712 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
714 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
718 * Update the record of the current time in a context.
720 static void update_context_time(struct perf_event_context
*ctx
)
722 u64 now
= perf_clock();
724 ctx
->time
+= now
- ctx
->timestamp
;
725 ctx
->timestamp
= now
;
728 static u64
perf_event_time(struct perf_event
*event
)
730 struct perf_event_context
*ctx
= event
->ctx
;
732 if (is_cgroup_event(event
))
733 return perf_cgroup_event_time(event
);
735 return ctx
? ctx
->time
: 0;
739 * Update the total_time_enabled and total_time_running fields for a event.
741 static void update_event_times(struct perf_event
*event
)
743 struct perf_event_context
*ctx
= event
->ctx
;
746 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
747 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
750 * in cgroup mode, time_enabled represents
751 * the time the event was enabled AND active
752 * tasks were in the monitored cgroup. This is
753 * independent of the activity of the context as
754 * there may be a mix of cgroup and non-cgroup events.
756 * That is why we treat cgroup events differently
759 if (is_cgroup_event(event
))
760 run_end
= perf_event_time(event
);
761 else if (ctx
->is_active
)
764 run_end
= event
->tstamp_stopped
;
766 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
768 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
769 run_end
= event
->tstamp_stopped
;
771 run_end
= perf_event_time(event
);
773 event
->total_time_running
= run_end
- event
->tstamp_running
;
778 * Update total_time_enabled and total_time_running for all events in a group.
780 static void update_group_times(struct perf_event
*leader
)
782 struct perf_event
*event
;
784 update_event_times(leader
);
785 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
786 update_event_times(event
);
789 static struct list_head
*
790 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
792 if (event
->attr
.pinned
)
793 return &ctx
->pinned_groups
;
795 return &ctx
->flexible_groups
;
799 * Add a event from the lists for its context.
800 * Must be called with ctx->mutex and ctx->lock held.
803 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
805 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
806 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
809 * If we're a stand alone event or group leader, we go to the context
810 * list, group events are kept attached to the group so that
811 * perf_group_detach can, at all times, locate all siblings.
813 if (event
->group_leader
== event
) {
814 struct list_head
*list
;
816 if (is_software_event(event
))
817 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
819 list
= ctx_group_list(event
, ctx
);
820 list_add_tail(&event
->group_entry
, list
);
823 if (is_cgroup_event(event
))
826 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
828 perf_pmu_rotate_start(ctx
->pmu
);
830 if (event
->attr
.inherit_stat
)
835 * Called at perf_event creation and when events are attached/detached from a
838 static void perf_event__read_size(struct perf_event
*event
)
840 int entry
= sizeof(u64
); /* value */
844 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
847 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
850 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
851 entry
+= sizeof(u64
);
853 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
854 nr
+= event
->group_leader
->nr_siblings
;
859 event
->read_size
= size
;
862 static void perf_event__header_size(struct perf_event
*event
)
864 struct perf_sample_data
*data
;
865 u64 sample_type
= event
->attr
.sample_type
;
868 perf_event__read_size(event
);
870 if (sample_type
& PERF_SAMPLE_IP
)
871 size
+= sizeof(data
->ip
);
873 if (sample_type
& PERF_SAMPLE_ADDR
)
874 size
+= sizeof(data
->addr
);
876 if (sample_type
& PERF_SAMPLE_PERIOD
)
877 size
+= sizeof(data
->period
);
879 if (sample_type
& PERF_SAMPLE_READ
)
880 size
+= event
->read_size
;
882 event
->header_size
= size
;
885 static void perf_event__id_header_size(struct perf_event
*event
)
887 struct perf_sample_data
*data
;
888 u64 sample_type
= event
->attr
.sample_type
;
891 if (sample_type
& PERF_SAMPLE_TID
)
892 size
+= sizeof(data
->tid_entry
);
894 if (sample_type
& PERF_SAMPLE_TIME
)
895 size
+= sizeof(data
->time
);
897 if (sample_type
& PERF_SAMPLE_ID
)
898 size
+= sizeof(data
->id
);
900 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
901 size
+= sizeof(data
->stream_id
);
903 if (sample_type
& PERF_SAMPLE_CPU
)
904 size
+= sizeof(data
->cpu_entry
);
906 event
->id_header_size
= size
;
909 static void perf_group_attach(struct perf_event
*event
)
911 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
914 * We can have double attach due to group movement in perf_event_open.
916 if (event
->attach_state
& PERF_ATTACH_GROUP
)
919 event
->attach_state
|= PERF_ATTACH_GROUP
;
921 if (group_leader
== event
)
924 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
925 !is_software_event(event
))
926 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
928 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
929 group_leader
->nr_siblings
++;
931 perf_event__header_size(group_leader
);
933 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
934 perf_event__header_size(pos
);
938 * Remove a event from the lists for its context.
939 * Must be called with ctx->mutex and ctx->lock held.
942 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
945 * We can have double detach due to exit/hot-unplug + close.
947 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
950 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
952 if (is_cgroup_event(event
))
956 if (event
->attr
.inherit_stat
)
959 list_del_rcu(&event
->event_entry
);
961 if (event
->group_leader
== event
)
962 list_del_init(&event
->group_entry
);
964 update_group_times(event
);
967 * If event was in error state, then keep it
968 * that way, otherwise bogus counts will be
969 * returned on read(). The only way to get out
970 * of error state is by explicit re-enabling
973 if (event
->state
> PERF_EVENT_STATE_OFF
)
974 event
->state
= PERF_EVENT_STATE_OFF
;
977 static void perf_group_detach(struct perf_event
*event
)
979 struct perf_event
*sibling
, *tmp
;
980 struct list_head
*list
= NULL
;
983 * We can have double detach due to exit/hot-unplug + close.
985 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
988 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
991 * If this is a sibling, remove it from its group.
993 if (event
->group_leader
!= event
) {
994 list_del_init(&event
->group_entry
);
995 event
->group_leader
->nr_siblings
--;
999 if (!list_empty(&event
->group_entry
))
1000 list
= &event
->group_entry
;
1003 * If this was a group event with sibling events then
1004 * upgrade the siblings to singleton events by adding them
1005 * to whatever list we are on.
1007 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1009 list_move_tail(&sibling
->group_entry
, list
);
1010 sibling
->group_leader
= sibling
;
1012 /* Inherit group flags from the previous leader */
1013 sibling
->group_flags
= event
->group_flags
;
1017 perf_event__header_size(event
->group_leader
);
1019 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1020 perf_event__header_size(tmp
);
1024 event_filter_match(struct perf_event
*event
)
1026 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1027 && perf_cgroup_match(event
);
1031 event_sched_out(struct perf_event
*event
,
1032 struct perf_cpu_context
*cpuctx
,
1033 struct perf_event_context
*ctx
)
1035 u64 tstamp
= perf_event_time(event
);
1038 * An event which could not be activated because of
1039 * filter mismatch still needs to have its timings
1040 * maintained, otherwise bogus information is return
1041 * via read() for time_enabled, time_running:
1043 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1044 && !event_filter_match(event
)) {
1045 delta
= tstamp
- event
->tstamp_stopped
;
1046 event
->tstamp_running
+= delta
;
1047 event
->tstamp_stopped
= tstamp
;
1050 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1053 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1054 if (event
->pending_disable
) {
1055 event
->pending_disable
= 0;
1056 event
->state
= PERF_EVENT_STATE_OFF
;
1058 event
->tstamp_stopped
= tstamp
;
1059 event
->pmu
->del(event
, 0);
1062 if (!is_software_event(event
))
1063 cpuctx
->active_oncpu
--;
1065 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1066 cpuctx
->exclusive
= 0;
1070 group_sched_out(struct perf_event
*group_event
,
1071 struct perf_cpu_context
*cpuctx
,
1072 struct perf_event_context
*ctx
)
1074 struct perf_event
*event
;
1075 int state
= group_event
->state
;
1077 event_sched_out(group_event
, cpuctx
, ctx
);
1080 * Schedule out siblings (if any):
1082 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1083 event_sched_out(event
, cpuctx
, ctx
);
1085 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1086 cpuctx
->exclusive
= 0;
1090 * Cross CPU call to remove a performance event
1092 * We disable the event on the hardware level first. After that we
1093 * remove it from the context list.
1095 static int __perf_remove_from_context(void *info
)
1097 struct perf_event
*event
= info
;
1098 struct perf_event_context
*ctx
= event
->ctx
;
1099 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1101 raw_spin_lock(&ctx
->lock
);
1102 event_sched_out(event
, cpuctx
, ctx
);
1103 list_del_event(event
, ctx
);
1104 raw_spin_unlock(&ctx
->lock
);
1111 * Remove the event from a task's (or a CPU's) list of events.
1113 * CPU events are removed with a smp call. For task events we only
1114 * call when the task is on a CPU.
1116 * If event->ctx is a cloned context, callers must make sure that
1117 * every task struct that event->ctx->task could possibly point to
1118 * remains valid. This is OK when called from perf_release since
1119 * that only calls us on the top-level context, which can't be a clone.
1120 * When called from perf_event_exit_task, it's OK because the
1121 * context has been detached from its task.
1123 static void perf_remove_from_context(struct perf_event
*event
)
1125 struct perf_event_context
*ctx
= event
->ctx
;
1126 struct task_struct
*task
= ctx
->task
;
1128 lockdep_assert_held(&ctx
->mutex
);
1132 * Per cpu events are removed via an smp call and
1133 * the removal is always successful.
1135 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1140 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1143 raw_spin_lock_irq(&ctx
->lock
);
1145 * If we failed to find a running task, but find the context active now
1146 * that we've acquired the ctx->lock, retry.
1148 if (ctx
->is_active
) {
1149 raw_spin_unlock_irq(&ctx
->lock
);
1154 * Since the task isn't running, its safe to remove the event, us
1155 * holding the ctx->lock ensures the task won't get scheduled in.
1157 list_del_event(event
, ctx
);
1158 raw_spin_unlock_irq(&ctx
->lock
);
1162 * Cross CPU call to disable a performance event
1164 static int __perf_event_disable(void *info
)
1166 struct perf_event
*event
= info
;
1167 struct perf_event_context
*ctx
= event
->ctx
;
1168 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1171 * If this is a per-task event, need to check whether this
1172 * event's task is the current task on this cpu.
1174 * Can trigger due to concurrent perf_event_context_sched_out()
1175 * flipping contexts around.
1177 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1180 raw_spin_lock(&ctx
->lock
);
1183 * If the event is on, turn it off.
1184 * If it is in error state, leave it in error state.
1186 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1187 update_context_time(ctx
);
1188 update_cgrp_time_from_event(event
);
1189 update_group_times(event
);
1190 if (event
== event
->group_leader
)
1191 group_sched_out(event
, cpuctx
, ctx
);
1193 event_sched_out(event
, cpuctx
, ctx
);
1194 event
->state
= PERF_EVENT_STATE_OFF
;
1197 raw_spin_unlock(&ctx
->lock
);
1205 * If event->ctx is a cloned context, callers must make sure that
1206 * every task struct that event->ctx->task could possibly point to
1207 * remains valid. This condition is satisifed when called through
1208 * perf_event_for_each_child or perf_event_for_each because they
1209 * hold the top-level event's child_mutex, so any descendant that
1210 * goes to exit will block in sync_child_event.
1211 * When called from perf_pending_event it's OK because event->ctx
1212 * is the current context on this CPU and preemption is disabled,
1213 * hence we can't get into perf_event_task_sched_out for this context.
1215 void perf_event_disable(struct perf_event
*event
)
1217 struct perf_event_context
*ctx
= event
->ctx
;
1218 struct task_struct
*task
= ctx
->task
;
1222 * Disable the event on the cpu that it's on
1224 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1229 if (!task_function_call(task
, __perf_event_disable
, event
))
1232 raw_spin_lock_irq(&ctx
->lock
);
1234 * If the event is still active, we need to retry the cross-call.
1236 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1237 raw_spin_unlock_irq(&ctx
->lock
);
1239 * Reload the task pointer, it might have been changed by
1240 * a concurrent perf_event_context_sched_out().
1247 * Since we have the lock this context can't be scheduled
1248 * in, so we can change the state safely.
1250 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1251 update_group_times(event
);
1252 event
->state
= PERF_EVENT_STATE_OFF
;
1254 raw_spin_unlock_irq(&ctx
->lock
);
1257 static void perf_set_shadow_time(struct perf_event
*event
,
1258 struct perf_event_context
*ctx
,
1262 * use the correct time source for the time snapshot
1264 * We could get by without this by leveraging the
1265 * fact that to get to this function, the caller
1266 * has most likely already called update_context_time()
1267 * and update_cgrp_time_xx() and thus both timestamp
1268 * are identical (or very close). Given that tstamp is,
1269 * already adjusted for cgroup, we could say that:
1270 * tstamp - ctx->timestamp
1272 * tstamp - cgrp->timestamp.
1274 * Then, in perf_output_read(), the calculation would
1275 * work with no changes because:
1276 * - event is guaranteed scheduled in
1277 * - no scheduled out in between
1278 * - thus the timestamp would be the same
1280 * But this is a bit hairy.
1282 * So instead, we have an explicit cgroup call to remain
1283 * within the time time source all along. We believe it
1284 * is cleaner and simpler to understand.
1286 if (is_cgroup_event(event
))
1287 perf_cgroup_set_shadow_time(event
, tstamp
);
1289 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1292 #define MAX_INTERRUPTS (~0ULL)
1294 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1297 event_sched_in(struct perf_event
*event
,
1298 struct perf_cpu_context
*cpuctx
,
1299 struct perf_event_context
*ctx
)
1301 u64 tstamp
= perf_event_time(event
);
1303 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1306 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1307 event
->oncpu
= smp_processor_id();
1310 * Unthrottle events, since we scheduled we might have missed several
1311 * ticks already, also for a heavily scheduling task there is little
1312 * guarantee it'll get a tick in a timely manner.
1314 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1315 perf_log_throttle(event
, 1);
1316 event
->hw
.interrupts
= 0;
1320 * The new state must be visible before we turn it on in the hardware:
1324 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1325 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1330 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1332 perf_set_shadow_time(event
, ctx
, tstamp
);
1334 if (!is_software_event(event
))
1335 cpuctx
->active_oncpu
++;
1338 if (event
->attr
.exclusive
)
1339 cpuctx
->exclusive
= 1;
1345 group_sched_in(struct perf_event
*group_event
,
1346 struct perf_cpu_context
*cpuctx
,
1347 struct perf_event_context
*ctx
)
1349 struct perf_event
*event
, *partial_group
= NULL
;
1350 struct pmu
*pmu
= group_event
->pmu
;
1351 u64 now
= ctx
->time
;
1352 bool simulate
= false;
1354 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1357 pmu
->start_txn(pmu
);
1359 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1360 pmu
->cancel_txn(pmu
);
1365 * Schedule in siblings as one group (if any):
1367 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1368 if (event_sched_in(event
, cpuctx
, ctx
)) {
1369 partial_group
= event
;
1374 if (!pmu
->commit_txn(pmu
))
1379 * Groups can be scheduled in as one unit only, so undo any
1380 * partial group before returning:
1381 * The events up to the failed event are scheduled out normally,
1382 * tstamp_stopped will be updated.
1384 * The failed events and the remaining siblings need to have
1385 * their timings updated as if they had gone thru event_sched_in()
1386 * and event_sched_out(). This is required to get consistent timings
1387 * across the group. This also takes care of the case where the group
1388 * could never be scheduled by ensuring tstamp_stopped is set to mark
1389 * the time the event was actually stopped, such that time delta
1390 * calculation in update_event_times() is correct.
1392 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1393 if (event
== partial_group
)
1397 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1398 event
->tstamp_stopped
= now
;
1400 event_sched_out(event
, cpuctx
, ctx
);
1403 event_sched_out(group_event
, cpuctx
, ctx
);
1405 pmu
->cancel_txn(pmu
);
1411 * Work out whether we can put this event group on the CPU now.
1413 static int group_can_go_on(struct perf_event
*event
,
1414 struct perf_cpu_context
*cpuctx
,
1418 * Groups consisting entirely of software events can always go on.
1420 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1423 * If an exclusive group is already on, no other hardware
1426 if (cpuctx
->exclusive
)
1429 * If this group is exclusive and there are already
1430 * events on the CPU, it can't go on.
1432 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1435 * Otherwise, try to add it if all previous groups were able
1441 static void add_event_to_ctx(struct perf_event
*event
,
1442 struct perf_event_context
*ctx
)
1444 u64 tstamp
= perf_event_time(event
);
1446 list_add_event(event
, ctx
);
1447 perf_group_attach(event
);
1448 event
->tstamp_enabled
= tstamp
;
1449 event
->tstamp_running
= tstamp
;
1450 event
->tstamp_stopped
= tstamp
;
1453 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
1454 struct task_struct
*tsk
);
1457 * Cross CPU call to install and enable a performance event
1459 * Must be called with ctx->mutex held
1461 static int __perf_install_in_context(void *info
)
1463 struct perf_event
*event
= info
;
1464 struct perf_event_context
*ctx
= event
->ctx
;
1465 struct perf_event
*leader
= event
->group_leader
;
1466 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1470 * In case we're installing a new context to an already running task,
1471 * could also happen before perf_event_task_sched_in() on architectures
1472 * which do context switches with IRQs enabled.
1474 if (ctx
->task
&& !cpuctx
->task_ctx
)
1475 perf_event_context_sched_in(ctx
, ctx
->task
);
1477 raw_spin_lock(&ctx
->lock
);
1479 update_context_time(ctx
);
1481 * update cgrp time only if current cgrp
1482 * matches event->cgrp. Must be done before
1483 * calling add_event_to_ctx()
1485 update_cgrp_time_from_event(event
);
1487 add_event_to_ctx(event
, ctx
);
1489 if (!event_filter_match(event
))
1493 * Don't put the event on if it is disabled or if
1494 * it is in a group and the group isn't on.
1496 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
1497 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
1501 * An exclusive event can't go on if there are already active
1502 * hardware events, and no hardware event can go on if there
1503 * is already an exclusive event on.
1505 if (!group_can_go_on(event
, cpuctx
, 1))
1508 err
= event_sched_in(event
, cpuctx
, ctx
);
1512 * This event couldn't go on. If it is in a group
1513 * then we have to pull the whole group off.
1514 * If the event group is pinned then put it in error state.
1516 if (leader
!= event
)
1517 group_sched_out(leader
, cpuctx
, ctx
);
1518 if (leader
->attr
.pinned
) {
1519 update_group_times(leader
);
1520 leader
->state
= PERF_EVENT_STATE_ERROR
;
1525 raw_spin_unlock(&ctx
->lock
);
1531 * Attach a performance event to a context
1533 * First we add the event to the list with the hardware enable bit
1534 * in event->hw_config cleared.
1536 * If the event is attached to a task which is on a CPU we use a smp
1537 * call to enable it in the task context. The task might have been
1538 * scheduled away, but we check this in the smp call again.
1541 perf_install_in_context(struct perf_event_context
*ctx
,
1542 struct perf_event
*event
,
1545 struct task_struct
*task
= ctx
->task
;
1547 lockdep_assert_held(&ctx
->mutex
);
1553 * Per cpu events are installed via an smp call and
1554 * the install is always successful.
1556 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1561 if (!task_function_call(task
, __perf_install_in_context
, event
))
1564 raw_spin_lock_irq(&ctx
->lock
);
1566 * If we failed to find a running task, but find the context active now
1567 * that we've acquired the ctx->lock, retry.
1569 if (ctx
->is_active
) {
1570 raw_spin_unlock_irq(&ctx
->lock
);
1575 * Since the task isn't running, its safe to add the event, us holding
1576 * the ctx->lock ensures the task won't get scheduled in.
1578 add_event_to_ctx(event
, ctx
);
1579 raw_spin_unlock_irq(&ctx
->lock
);
1583 * Put a event into inactive state and update time fields.
1584 * Enabling the leader of a group effectively enables all
1585 * the group members that aren't explicitly disabled, so we
1586 * have to update their ->tstamp_enabled also.
1587 * Note: this works for group members as well as group leaders
1588 * since the non-leader members' sibling_lists will be empty.
1590 static void __perf_event_mark_enabled(struct perf_event
*event
,
1591 struct perf_event_context
*ctx
)
1593 struct perf_event
*sub
;
1594 u64 tstamp
= perf_event_time(event
);
1596 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1597 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1598 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1599 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1600 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1605 * Cross CPU call to enable a performance event
1607 static int __perf_event_enable(void *info
)
1609 struct perf_event
*event
= info
;
1610 struct perf_event_context
*ctx
= event
->ctx
;
1611 struct perf_event
*leader
= event
->group_leader
;
1612 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1615 if (WARN_ON_ONCE(!ctx
->is_active
))
1618 raw_spin_lock(&ctx
->lock
);
1619 update_context_time(ctx
);
1621 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1625 * set current task's cgroup time reference point
1627 perf_cgroup_set_timestamp(current
, ctx
);
1629 __perf_event_mark_enabled(event
, ctx
);
1631 if (!event_filter_match(event
)) {
1632 if (is_cgroup_event(event
))
1633 perf_cgroup_defer_enabled(event
);
1638 * If the event is in a group and isn't the group leader,
1639 * then don't put it on unless the group is on.
1641 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1644 if (!group_can_go_on(event
, cpuctx
, 1)) {
1647 if (event
== leader
)
1648 err
= group_sched_in(event
, cpuctx
, ctx
);
1650 err
= event_sched_in(event
, cpuctx
, ctx
);
1655 * If this event can't go on and it's part of a
1656 * group, then the whole group has to come off.
1658 if (leader
!= event
)
1659 group_sched_out(leader
, cpuctx
, ctx
);
1660 if (leader
->attr
.pinned
) {
1661 update_group_times(leader
);
1662 leader
->state
= PERF_EVENT_STATE_ERROR
;
1667 raw_spin_unlock(&ctx
->lock
);
1675 * If event->ctx is a cloned context, callers must make sure that
1676 * every task struct that event->ctx->task could possibly point to
1677 * remains valid. This condition is satisfied when called through
1678 * perf_event_for_each_child or perf_event_for_each as described
1679 * for perf_event_disable.
1681 void perf_event_enable(struct perf_event
*event
)
1683 struct perf_event_context
*ctx
= event
->ctx
;
1684 struct task_struct
*task
= ctx
->task
;
1688 * Enable the event on the cpu that it's on
1690 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
1694 raw_spin_lock_irq(&ctx
->lock
);
1695 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1699 * If the event is in error state, clear that first.
1700 * That way, if we see the event in error state below, we
1701 * know that it has gone back into error state, as distinct
1702 * from the task having been scheduled away before the
1703 * cross-call arrived.
1705 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1706 event
->state
= PERF_EVENT_STATE_OFF
;
1709 if (!ctx
->is_active
) {
1710 __perf_event_mark_enabled(event
, ctx
);
1714 raw_spin_unlock_irq(&ctx
->lock
);
1716 if (!task_function_call(task
, __perf_event_enable
, event
))
1719 raw_spin_lock_irq(&ctx
->lock
);
1722 * If the context is active and the event is still off,
1723 * we need to retry the cross-call.
1725 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
1727 * task could have been flipped by a concurrent
1728 * perf_event_context_sched_out()
1735 raw_spin_unlock_irq(&ctx
->lock
);
1738 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1741 * not supported on inherited events
1743 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1746 atomic_add(refresh
, &event
->event_limit
);
1747 perf_event_enable(event
);
1752 static void ctx_sched_out(struct perf_event_context
*ctx
,
1753 struct perf_cpu_context
*cpuctx
,
1754 enum event_type_t event_type
)
1756 struct perf_event
*event
;
1758 raw_spin_lock(&ctx
->lock
);
1759 perf_pmu_disable(ctx
->pmu
);
1761 if (likely(!ctx
->nr_events
))
1763 update_context_time(ctx
);
1764 update_cgrp_time_from_cpuctx(cpuctx
);
1766 if (!ctx
->nr_active
)
1769 if (event_type
& EVENT_PINNED
) {
1770 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1771 group_sched_out(event
, cpuctx
, ctx
);
1774 if (event_type
& EVENT_FLEXIBLE
) {
1775 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1776 group_sched_out(event
, cpuctx
, ctx
);
1779 perf_pmu_enable(ctx
->pmu
);
1780 raw_spin_unlock(&ctx
->lock
);
1784 * Test whether two contexts are equivalent, i.e. whether they
1785 * have both been cloned from the same version of the same context
1786 * and they both have the same number of enabled events.
1787 * If the number of enabled events is the same, then the set
1788 * of enabled events should be the same, because these are both
1789 * inherited contexts, therefore we can't access individual events
1790 * in them directly with an fd; we can only enable/disable all
1791 * events via prctl, or enable/disable all events in a family
1792 * via ioctl, which will have the same effect on both contexts.
1794 static int context_equiv(struct perf_event_context
*ctx1
,
1795 struct perf_event_context
*ctx2
)
1797 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1798 && ctx1
->parent_gen
== ctx2
->parent_gen
1799 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1802 static void __perf_event_sync_stat(struct perf_event
*event
,
1803 struct perf_event
*next_event
)
1807 if (!event
->attr
.inherit_stat
)
1811 * Update the event value, we cannot use perf_event_read()
1812 * because we're in the middle of a context switch and have IRQs
1813 * disabled, which upsets smp_call_function_single(), however
1814 * we know the event must be on the current CPU, therefore we
1815 * don't need to use it.
1817 switch (event
->state
) {
1818 case PERF_EVENT_STATE_ACTIVE
:
1819 event
->pmu
->read(event
);
1822 case PERF_EVENT_STATE_INACTIVE
:
1823 update_event_times(event
);
1831 * In order to keep per-task stats reliable we need to flip the event
1832 * values when we flip the contexts.
1834 value
= local64_read(&next_event
->count
);
1835 value
= local64_xchg(&event
->count
, value
);
1836 local64_set(&next_event
->count
, value
);
1838 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1839 swap(event
->total_time_running
, next_event
->total_time_running
);
1842 * Since we swizzled the values, update the user visible data too.
1844 perf_event_update_userpage(event
);
1845 perf_event_update_userpage(next_event
);
1848 #define list_next_entry(pos, member) \
1849 list_entry(pos->member.next, typeof(*pos), member)
1851 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1852 struct perf_event_context
*next_ctx
)
1854 struct perf_event
*event
, *next_event
;
1859 update_context_time(ctx
);
1861 event
= list_first_entry(&ctx
->event_list
,
1862 struct perf_event
, event_entry
);
1864 next_event
= list_first_entry(&next_ctx
->event_list
,
1865 struct perf_event
, event_entry
);
1867 while (&event
->event_entry
!= &ctx
->event_list
&&
1868 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1870 __perf_event_sync_stat(event
, next_event
);
1872 event
= list_next_entry(event
, event_entry
);
1873 next_event
= list_next_entry(next_event
, event_entry
);
1877 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
1878 struct task_struct
*next
)
1880 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
1881 struct perf_event_context
*next_ctx
;
1882 struct perf_event_context
*parent
;
1883 struct perf_cpu_context
*cpuctx
;
1889 cpuctx
= __get_cpu_context(ctx
);
1890 if (!cpuctx
->task_ctx
)
1894 parent
= rcu_dereference(ctx
->parent_ctx
);
1895 next_ctx
= next
->perf_event_ctxp
[ctxn
];
1896 if (parent
&& next_ctx
&&
1897 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1899 * Looks like the two contexts are clones, so we might be
1900 * able to optimize the context switch. We lock both
1901 * contexts and check that they are clones under the
1902 * lock (including re-checking that neither has been
1903 * uncloned in the meantime). It doesn't matter which
1904 * order we take the locks because no other cpu could
1905 * be trying to lock both of these tasks.
1907 raw_spin_lock(&ctx
->lock
);
1908 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1909 if (context_equiv(ctx
, next_ctx
)) {
1911 * XXX do we need a memory barrier of sorts
1912 * wrt to rcu_dereference() of perf_event_ctxp
1914 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
1915 next
->perf_event_ctxp
[ctxn
] = ctx
;
1917 next_ctx
->task
= task
;
1920 perf_event_sync_stat(ctx
, next_ctx
);
1922 raw_spin_unlock(&next_ctx
->lock
);
1923 raw_spin_unlock(&ctx
->lock
);
1928 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1929 cpuctx
->task_ctx
= NULL
;
1933 #define for_each_task_context_nr(ctxn) \
1934 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
1937 * Called from scheduler to remove the events of the current task,
1938 * with interrupts disabled.
1940 * We stop each event and update the event value in event->count.
1942 * This does not protect us against NMI, but disable()
1943 * sets the disabled bit in the control field of event _before_
1944 * accessing the event control register. If a NMI hits, then it will
1945 * not restart the event.
1947 void __perf_event_task_sched_out(struct task_struct
*task
,
1948 struct task_struct
*next
)
1952 for_each_task_context_nr(ctxn
)
1953 perf_event_context_sched_out(task
, ctxn
, next
);
1956 * if cgroup events exist on this CPU, then we need
1957 * to check if we have to switch out PMU state.
1958 * cgroup event are system-wide mode only
1960 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
1961 perf_cgroup_sched_out(task
);
1964 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1965 enum event_type_t event_type
)
1967 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1969 if (!cpuctx
->task_ctx
)
1972 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1975 ctx_sched_out(ctx
, cpuctx
, event_type
);
1976 cpuctx
->task_ctx
= NULL
;
1980 * Called with IRQs disabled
1982 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1983 enum event_type_t event_type
)
1985 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1989 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1990 struct perf_cpu_context
*cpuctx
)
1992 struct perf_event
*event
;
1994 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1995 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1997 if (!event_filter_match(event
))
2000 /* may need to reset tstamp_enabled */
2001 if (is_cgroup_event(event
))
2002 perf_cgroup_mark_enabled(event
, ctx
);
2004 if (group_can_go_on(event
, cpuctx
, 1))
2005 group_sched_in(event
, cpuctx
, ctx
);
2008 * If this pinned group hasn't been scheduled,
2009 * put it in error state.
2011 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2012 update_group_times(event
);
2013 event
->state
= PERF_EVENT_STATE_ERROR
;
2019 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2020 struct perf_cpu_context
*cpuctx
)
2022 struct perf_event
*event
;
2025 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2026 /* Ignore events in OFF or ERROR state */
2027 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2030 * Listen to the 'cpu' scheduling filter constraint
2033 if (!event_filter_match(event
))
2036 /* may need to reset tstamp_enabled */
2037 if (is_cgroup_event(event
))
2038 perf_cgroup_mark_enabled(event
, ctx
);
2040 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2041 if (group_sched_in(event
, cpuctx
, ctx
))
2048 ctx_sched_in(struct perf_event_context
*ctx
,
2049 struct perf_cpu_context
*cpuctx
,
2050 enum event_type_t event_type
,
2051 struct task_struct
*task
)
2055 raw_spin_lock(&ctx
->lock
);
2057 if (likely(!ctx
->nr_events
))
2061 ctx
->timestamp
= now
;
2062 perf_cgroup_set_timestamp(task
, ctx
);
2064 * First go through the list and put on any pinned groups
2065 * in order to give them the best chance of going on.
2067 if (event_type
& EVENT_PINNED
)
2068 ctx_pinned_sched_in(ctx
, cpuctx
);
2070 /* Then walk through the lower prio flexible groups */
2071 if (event_type
& EVENT_FLEXIBLE
)
2072 ctx_flexible_sched_in(ctx
, cpuctx
);
2075 raw_spin_unlock(&ctx
->lock
);
2078 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2079 enum event_type_t event_type
,
2080 struct task_struct
*task
)
2082 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2084 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2087 static void task_ctx_sched_in(struct perf_event_context
*ctx
,
2088 enum event_type_t event_type
)
2090 struct perf_cpu_context
*cpuctx
;
2092 cpuctx
= __get_cpu_context(ctx
);
2093 if (cpuctx
->task_ctx
== ctx
)
2096 ctx_sched_in(ctx
, cpuctx
, event_type
, NULL
);
2097 cpuctx
->task_ctx
= ctx
;
2100 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2101 struct task_struct
*task
)
2103 struct perf_cpu_context
*cpuctx
;
2105 cpuctx
= __get_cpu_context(ctx
);
2106 if (cpuctx
->task_ctx
== ctx
)
2109 perf_pmu_disable(ctx
->pmu
);
2111 * We want to keep the following priority order:
2112 * cpu pinned (that don't need to move), task pinned,
2113 * cpu flexible, task flexible.
2115 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2117 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2118 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2119 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2121 cpuctx
->task_ctx
= ctx
;
2124 * Since these rotations are per-cpu, we need to ensure the
2125 * cpu-context we got scheduled on is actually rotating.
2127 perf_pmu_rotate_start(ctx
->pmu
);
2128 perf_pmu_enable(ctx
->pmu
);
2132 * Called from scheduler to add the events of the current task
2133 * with interrupts disabled.
2135 * We restore the event value and then enable it.
2137 * This does not protect us against NMI, but enable()
2138 * sets the enabled bit in the control field of event _before_
2139 * accessing the event control register. If a NMI hits, then it will
2140 * keep the event running.
2142 void __perf_event_task_sched_in(struct task_struct
*task
)
2144 struct perf_event_context
*ctx
;
2147 for_each_task_context_nr(ctxn
) {
2148 ctx
= task
->perf_event_ctxp
[ctxn
];
2152 perf_event_context_sched_in(ctx
, task
);
2155 * if cgroup events exist on this CPU, then we need
2156 * to check if we have to switch in PMU state.
2157 * cgroup event are system-wide mode only
2159 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2160 perf_cgroup_sched_in(task
);
2163 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2165 u64 frequency
= event
->attr
.sample_freq
;
2166 u64 sec
= NSEC_PER_SEC
;
2167 u64 divisor
, dividend
;
2169 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2171 count_fls
= fls64(count
);
2172 nsec_fls
= fls64(nsec
);
2173 frequency_fls
= fls64(frequency
);
2177 * We got @count in @nsec, with a target of sample_freq HZ
2178 * the target period becomes:
2181 * period = -------------------
2182 * @nsec * sample_freq
2187 * Reduce accuracy by one bit such that @a and @b converge
2188 * to a similar magnitude.
2190 #define REDUCE_FLS(a, b) \
2192 if (a##_fls > b##_fls) { \
2202 * Reduce accuracy until either term fits in a u64, then proceed with
2203 * the other, so that finally we can do a u64/u64 division.
2205 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2206 REDUCE_FLS(nsec
, frequency
);
2207 REDUCE_FLS(sec
, count
);
2210 if (count_fls
+ sec_fls
> 64) {
2211 divisor
= nsec
* frequency
;
2213 while (count_fls
+ sec_fls
> 64) {
2214 REDUCE_FLS(count
, sec
);
2218 dividend
= count
* sec
;
2220 dividend
= count
* sec
;
2222 while (nsec_fls
+ frequency_fls
> 64) {
2223 REDUCE_FLS(nsec
, frequency
);
2227 divisor
= nsec
* frequency
;
2233 return div64_u64(dividend
, divisor
);
2236 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2238 struct hw_perf_event
*hwc
= &event
->hw
;
2239 s64 period
, sample_period
;
2242 period
= perf_calculate_period(event
, nsec
, count
);
2244 delta
= (s64
)(period
- hwc
->sample_period
);
2245 delta
= (delta
+ 7) / 8; /* low pass filter */
2247 sample_period
= hwc
->sample_period
+ delta
;
2252 hwc
->sample_period
= sample_period
;
2254 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2255 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2256 local64_set(&hwc
->period_left
, 0);
2257 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2261 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
, u64 period
)
2263 struct perf_event
*event
;
2264 struct hw_perf_event
*hwc
;
2265 u64 interrupts
, now
;
2268 raw_spin_lock(&ctx
->lock
);
2269 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2270 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2273 if (!event_filter_match(event
))
2278 interrupts
= hwc
->interrupts
;
2279 hwc
->interrupts
= 0;
2282 * unthrottle events on the tick
2284 if (interrupts
== MAX_INTERRUPTS
) {
2285 perf_log_throttle(event
, 1);
2286 event
->pmu
->start(event
, 0);
2289 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2292 event
->pmu
->read(event
);
2293 now
= local64_read(&event
->count
);
2294 delta
= now
- hwc
->freq_count_stamp
;
2295 hwc
->freq_count_stamp
= now
;
2298 perf_adjust_period(event
, period
, delta
);
2300 raw_spin_unlock(&ctx
->lock
);
2304 * Round-robin a context's events:
2306 static void rotate_ctx(struct perf_event_context
*ctx
)
2308 raw_spin_lock(&ctx
->lock
);
2311 * Rotate the first entry last of non-pinned groups. Rotation might be
2312 * disabled by the inheritance code.
2314 if (!ctx
->rotate_disable
)
2315 list_rotate_left(&ctx
->flexible_groups
);
2317 raw_spin_unlock(&ctx
->lock
);
2321 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2322 * because they're strictly cpu affine and rotate_start is called with IRQs
2323 * disabled, while rotate_context is called from IRQ context.
2325 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2327 u64 interval
= (u64
)cpuctx
->jiffies_interval
* TICK_NSEC
;
2328 struct perf_event_context
*ctx
= NULL
;
2329 int rotate
= 0, remove
= 1;
2331 if (cpuctx
->ctx
.nr_events
) {
2333 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2337 ctx
= cpuctx
->task_ctx
;
2338 if (ctx
&& ctx
->nr_events
) {
2340 if (ctx
->nr_events
!= ctx
->nr_active
)
2344 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2345 perf_ctx_adjust_freq(&cpuctx
->ctx
, interval
);
2347 perf_ctx_adjust_freq(ctx
, interval
);
2352 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2354 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
2356 rotate_ctx(&cpuctx
->ctx
);
2360 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, current
);
2362 task_ctx_sched_in(ctx
, EVENT_FLEXIBLE
);
2366 list_del_init(&cpuctx
->rotation_list
);
2368 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2371 void perf_event_task_tick(void)
2373 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2374 struct perf_cpu_context
*cpuctx
, *tmp
;
2376 WARN_ON(!irqs_disabled());
2378 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2379 if (cpuctx
->jiffies_interval
== 1 ||
2380 !(jiffies
% cpuctx
->jiffies_interval
))
2381 perf_rotate_context(cpuctx
);
2385 static int event_enable_on_exec(struct perf_event
*event
,
2386 struct perf_event_context
*ctx
)
2388 if (!event
->attr
.enable_on_exec
)
2391 event
->attr
.enable_on_exec
= 0;
2392 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2395 __perf_event_mark_enabled(event
, ctx
);
2401 * Enable all of a task's events that have been marked enable-on-exec.
2402 * This expects task == current.
2404 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2406 struct perf_event
*event
;
2407 unsigned long flags
;
2411 local_irq_save(flags
);
2412 if (!ctx
|| !ctx
->nr_events
)
2415 task_ctx_sched_out(ctx
, EVENT_ALL
);
2417 raw_spin_lock(&ctx
->lock
);
2419 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2420 ret
= event_enable_on_exec(event
, ctx
);
2425 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2426 ret
= event_enable_on_exec(event
, ctx
);
2432 * Unclone this context if we enabled any event.
2437 raw_spin_unlock(&ctx
->lock
);
2439 perf_event_context_sched_in(ctx
, ctx
->task
);
2441 local_irq_restore(flags
);
2445 * Cross CPU call to read the hardware event
2447 static void __perf_event_read(void *info
)
2449 struct perf_event
*event
= info
;
2450 struct perf_event_context
*ctx
= event
->ctx
;
2451 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2454 * If this is a task context, we need to check whether it is
2455 * the current task context of this cpu. If not it has been
2456 * scheduled out before the smp call arrived. In that case
2457 * event->count would have been updated to a recent sample
2458 * when the event was scheduled out.
2460 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2463 raw_spin_lock(&ctx
->lock
);
2464 if (ctx
->is_active
) {
2465 update_context_time(ctx
);
2466 update_cgrp_time_from_event(event
);
2468 update_event_times(event
);
2469 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2470 event
->pmu
->read(event
);
2471 raw_spin_unlock(&ctx
->lock
);
2474 static inline u64
perf_event_count(struct perf_event
*event
)
2476 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2479 static u64
perf_event_read(struct perf_event
*event
)
2482 * If event is enabled and currently active on a CPU, update the
2483 * value in the event structure:
2485 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2486 smp_call_function_single(event
->oncpu
,
2487 __perf_event_read
, event
, 1);
2488 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2489 struct perf_event_context
*ctx
= event
->ctx
;
2490 unsigned long flags
;
2492 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2494 * may read while context is not active
2495 * (e.g., thread is blocked), in that case
2496 * we cannot update context time
2498 if (ctx
->is_active
) {
2499 update_context_time(ctx
);
2500 update_cgrp_time_from_event(event
);
2502 update_event_times(event
);
2503 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2506 return perf_event_count(event
);
2513 struct callchain_cpus_entries
{
2514 struct rcu_head rcu_head
;
2515 struct perf_callchain_entry
*cpu_entries
[0];
2518 static DEFINE_PER_CPU(int, callchain_recursion
[PERF_NR_CONTEXTS
]);
2519 static atomic_t nr_callchain_events
;
2520 static DEFINE_MUTEX(callchain_mutex
);
2521 struct callchain_cpus_entries
*callchain_cpus_entries
;
2524 __weak
void perf_callchain_kernel(struct perf_callchain_entry
*entry
,
2525 struct pt_regs
*regs
)
2529 __weak
void perf_callchain_user(struct perf_callchain_entry
*entry
,
2530 struct pt_regs
*regs
)
2534 static void release_callchain_buffers_rcu(struct rcu_head
*head
)
2536 struct callchain_cpus_entries
*entries
;
2539 entries
= container_of(head
, struct callchain_cpus_entries
, rcu_head
);
2541 for_each_possible_cpu(cpu
)
2542 kfree(entries
->cpu_entries
[cpu
]);
2547 static void release_callchain_buffers(void)
2549 struct callchain_cpus_entries
*entries
;
2551 entries
= callchain_cpus_entries
;
2552 rcu_assign_pointer(callchain_cpus_entries
, NULL
);
2553 call_rcu(&entries
->rcu_head
, release_callchain_buffers_rcu
);
2556 static int alloc_callchain_buffers(void)
2560 struct callchain_cpus_entries
*entries
;
2563 * We can't use the percpu allocation API for data that can be
2564 * accessed from NMI. Use a temporary manual per cpu allocation
2565 * until that gets sorted out.
2567 size
= offsetof(struct callchain_cpus_entries
, cpu_entries
[nr_cpu_ids
]);
2569 entries
= kzalloc(size
, GFP_KERNEL
);
2573 size
= sizeof(struct perf_callchain_entry
) * PERF_NR_CONTEXTS
;
2575 for_each_possible_cpu(cpu
) {
2576 entries
->cpu_entries
[cpu
] = kmalloc_node(size
, GFP_KERNEL
,
2578 if (!entries
->cpu_entries
[cpu
])
2582 rcu_assign_pointer(callchain_cpus_entries
, entries
);
2587 for_each_possible_cpu(cpu
)
2588 kfree(entries
->cpu_entries
[cpu
]);
2594 static int get_callchain_buffers(void)
2599 mutex_lock(&callchain_mutex
);
2601 count
= atomic_inc_return(&nr_callchain_events
);
2602 if (WARN_ON_ONCE(count
< 1)) {
2608 /* If the allocation failed, give up */
2609 if (!callchain_cpus_entries
)
2614 err
= alloc_callchain_buffers();
2616 release_callchain_buffers();
2618 mutex_unlock(&callchain_mutex
);
2623 static void put_callchain_buffers(void)
2625 if (atomic_dec_and_mutex_lock(&nr_callchain_events
, &callchain_mutex
)) {
2626 release_callchain_buffers();
2627 mutex_unlock(&callchain_mutex
);
2631 static int get_recursion_context(int *recursion
)
2639 else if (in_softirq())
2644 if (recursion
[rctx
])
2653 static inline void put_recursion_context(int *recursion
, int rctx
)
2659 static struct perf_callchain_entry
*get_callchain_entry(int *rctx
)
2662 struct callchain_cpus_entries
*entries
;
2664 *rctx
= get_recursion_context(__get_cpu_var(callchain_recursion
));
2668 entries
= rcu_dereference(callchain_cpus_entries
);
2672 cpu
= smp_processor_id();
2674 return &entries
->cpu_entries
[cpu
][*rctx
];
2678 put_callchain_entry(int rctx
)
2680 put_recursion_context(__get_cpu_var(callchain_recursion
), rctx
);
2683 static struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2686 struct perf_callchain_entry
*entry
;
2689 entry
= get_callchain_entry(&rctx
);
2698 if (!user_mode(regs
)) {
2699 perf_callchain_store(entry
, PERF_CONTEXT_KERNEL
);
2700 perf_callchain_kernel(entry
, regs
);
2702 regs
= task_pt_regs(current
);
2708 perf_callchain_store(entry
, PERF_CONTEXT_USER
);
2709 perf_callchain_user(entry
, regs
);
2713 put_callchain_entry(rctx
);
2719 * Initialize the perf_event context in a task_struct:
2721 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2723 raw_spin_lock_init(&ctx
->lock
);
2724 mutex_init(&ctx
->mutex
);
2725 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2726 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2727 INIT_LIST_HEAD(&ctx
->event_list
);
2728 atomic_set(&ctx
->refcount
, 1);
2731 static struct perf_event_context
*
2732 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2734 struct perf_event_context
*ctx
;
2736 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2740 __perf_event_init_context(ctx
);
2743 get_task_struct(task
);
2750 static struct task_struct
*
2751 find_lively_task_by_vpid(pid_t vpid
)
2753 struct task_struct
*task
;
2760 task
= find_task_by_vpid(vpid
);
2762 get_task_struct(task
);
2766 return ERR_PTR(-ESRCH
);
2768 /* Reuse ptrace permission checks for now. */
2770 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2775 put_task_struct(task
);
2776 return ERR_PTR(err
);
2781 * Returns a matching context with refcount and pincount.
2783 static struct perf_event_context
*
2784 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2786 struct perf_event_context
*ctx
;
2787 struct perf_cpu_context
*cpuctx
;
2788 unsigned long flags
;
2792 /* Must be root to operate on a CPU event: */
2793 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2794 return ERR_PTR(-EACCES
);
2797 * We could be clever and allow to attach a event to an
2798 * offline CPU and activate it when the CPU comes up, but
2801 if (!cpu_online(cpu
))
2802 return ERR_PTR(-ENODEV
);
2804 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2813 ctxn
= pmu
->task_ctx_nr
;
2818 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2822 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2826 ctx
= alloc_perf_context(pmu
, task
);
2834 mutex_lock(&task
->perf_event_mutex
);
2836 * If it has already passed perf_event_exit_task().
2837 * we must see PF_EXITING, it takes this mutex too.
2839 if (task
->flags
& PF_EXITING
)
2841 else if (task
->perf_event_ctxp
[ctxn
])
2845 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2847 mutex_unlock(&task
->perf_event_mutex
);
2849 if (unlikely(err
)) {
2850 put_task_struct(task
);
2862 return ERR_PTR(err
);
2865 static void perf_event_free_filter(struct perf_event
*event
);
2867 static void free_event_rcu(struct rcu_head
*head
)
2869 struct perf_event
*event
;
2871 event
= container_of(head
, struct perf_event
, rcu_head
);
2873 put_pid_ns(event
->ns
);
2874 perf_event_free_filter(event
);
2878 static void perf_buffer_put(struct perf_buffer
*buffer
);
2880 static void free_event(struct perf_event
*event
)
2882 irq_work_sync(&event
->pending
);
2884 if (!event
->parent
) {
2885 if (event
->attach_state
& PERF_ATTACH_TASK
)
2886 jump_label_dec(&perf_sched_events
);
2887 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2888 atomic_dec(&nr_mmap_events
);
2889 if (event
->attr
.comm
)
2890 atomic_dec(&nr_comm_events
);
2891 if (event
->attr
.task
)
2892 atomic_dec(&nr_task_events
);
2893 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2894 put_callchain_buffers();
2895 if (is_cgroup_event(event
)) {
2896 atomic_dec(&per_cpu(perf_cgroup_events
, event
->cpu
));
2897 jump_label_dec(&perf_sched_events
);
2901 if (event
->buffer
) {
2902 perf_buffer_put(event
->buffer
);
2903 event
->buffer
= NULL
;
2906 if (is_cgroup_event(event
))
2907 perf_detach_cgroup(event
);
2910 event
->destroy(event
);
2913 put_ctx(event
->ctx
);
2915 call_rcu(&event
->rcu_head
, free_event_rcu
);
2918 int perf_event_release_kernel(struct perf_event
*event
)
2920 struct perf_event_context
*ctx
= event
->ctx
;
2923 * Remove from the PMU, can't get re-enabled since we got
2924 * here because the last ref went.
2926 perf_event_disable(event
);
2928 WARN_ON_ONCE(ctx
->parent_ctx
);
2930 * There are two ways this annotation is useful:
2932 * 1) there is a lock recursion from perf_event_exit_task
2933 * see the comment there.
2935 * 2) there is a lock-inversion with mmap_sem through
2936 * perf_event_read_group(), which takes faults while
2937 * holding ctx->mutex, however this is called after
2938 * the last filedesc died, so there is no possibility
2939 * to trigger the AB-BA case.
2941 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2942 raw_spin_lock_irq(&ctx
->lock
);
2943 perf_group_detach(event
);
2944 list_del_event(event
, ctx
);
2945 raw_spin_unlock_irq(&ctx
->lock
);
2946 mutex_unlock(&ctx
->mutex
);
2952 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2955 * Called when the last reference to the file is gone.
2957 static int perf_release(struct inode
*inode
, struct file
*file
)
2959 struct perf_event
*event
= file
->private_data
;
2960 struct task_struct
*owner
;
2962 file
->private_data
= NULL
;
2965 owner
= ACCESS_ONCE(event
->owner
);
2967 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2968 * !owner it means the list deletion is complete and we can indeed
2969 * free this event, otherwise we need to serialize on
2970 * owner->perf_event_mutex.
2972 smp_read_barrier_depends();
2975 * Since delayed_put_task_struct() also drops the last
2976 * task reference we can safely take a new reference
2977 * while holding the rcu_read_lock().
2979 get_task_struct(owner
);
2984 mutex_lock(&owner
->perf_event_mutex
);
2986 * We have to re-check the event->owner field, if it is cleared
2987 * we raced with perf_event_exit_task(), acquiring the mutex
2988 * ensured they're done, and we can proceed with freeing the
2992 list_del_init(&event
->owner_entry
);
2993 mutex_unlock(&owner
->perf_event_mutex
);
2994 put_task_struct(owner
);
2997 return perf_event_release_kernel(event
);
3000 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3002 struct perf_event
*child
;
3008 mutex_lock(&event
->child_mutex
);
3009 total
+= perf_event_read(event
);
3010 *enabled
+= event
->total_time_enabled
+
3011 atomic64_read(&event
->child_total_time_enabled
);
3012 *running
+= event
->total_time_running
+
3013 atomic64_read(&event
->child_total_time_running
);
3015 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3016 total
+= perf_event_read(child
);
3017 *enabled
+= child
->total_time_enabled
;
3018 *running
+= child
->total_time_running
;
3020 mutex_unlock(&event
->child_mutex
);
3024 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3026 static int perf_event_read_group(struct perf_event
*event
,
3027 u64 read_format
, char __user
*buf
)
3029 struct perf_event
*leader
= event
->group_leader
, *sub
;
3030 int n
= 0, size
= 0, ret
= -EFAULT
;
3031 struct perf_event_context
*ctx
= leader
->ctx
;
3033 u64 count
, enabled
, running
;
3035 mutex_lock(&ctx
->mutex
);
3036 count
= perf_event_read_value(leader
, &enabled
, &running
);
3038 values
[n
++] = 1 + leader
->nr_siblings
;
3039 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3040 values
[n
++] = enabled
;
3041 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3042 values
[n
++] = running
;
3043 values
[n
++] = count
;
3044 if (read_format
& PERF_FORMAT_ID
)
3045 values
[n
++] = primary_event_id(leader
);
3047 size
= n
* sizeof(u64
);
3049 if (copy_to_user(buf
, values
, size
))
3054 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3057 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3058 if (read_format
& PERF_FORMAT_ID
)
3059 values
[n
++] = primary_event_id(sub
);
3061 size
= n
* sizeof(u64
);
3063 if (copy_to_user(buf
+ ret
, values
, size
)) {
3071 mutex_unlock(&ctx
->mutex
);
3076 static int perf_event_read_one(struct perf_event
*event
,
3077 u64 read_format
, char __user
*buf
)
3079 u64 enabled
, running
;
3083 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3084 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3085 values
[n
++] = enabled
;
3086 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3087 values
[n
++] = running
;
3088 if (read_format
& PERF_FORMAT_ID
)
3089 values
[n
++] = primary_event_id(event
);
3091 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3094 return n
* sizeof(u64
);
3098 * Read the performance event - simple non blocking version for now
3101 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3103 u64 read_format
= event
->attr
.read_format
;
3107 * Return end-of-file for a read on a event that is in
3108 * error state (i.e. because it was pinned but it couldn't be
3109 * scheduled on to the CPU at some point).
3111 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3114 if (count
< event
->read_size
)
3117 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3118 if (read_format
& PERF_FORMAT_GROUP
)
3119 ret
= perf_event_read_group(event
, read_format
, buf
);
3121 ret
= perf_event_read_one(event
, read_format
, buf
);
3127 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3129 struct perf_event
*event
= file
->private_data
;
3131 return perf_read_hw(event
, buf
, count
);
3134 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3136 struct perf_event
*event
= file
->private_data
;
3137 struct perf_buffer
*buffer
;
3138 unsigned int events
= POLL_HUP
;
3141 buffer
= rcu_dereference(event
->buffer
);
3143 events
= atomic_xchg(&buffer
->poll
, 0);
3146 poll_wait(file
, &event
->waitq
, wait
);
3151 static void perf_event_reset(struct perf_event
*event
)
3153 (void)perf_event_read(event
);
3154 local64_set(&event
->count
, 0);
3155 perf_event_update_userpage(event
);
3159 * Holding the top-level event's child_mutex means that any
3160 * descendant process that has inherited this event will block
3161 * in sync_child_event if it goes to exit, thus satisfying the
3162 * task existence requirements of perf_event_enable/disable.
3164 static void perf_event_for_each_child(struct perf_event
*event
,
3165 void (*func
)(struct perf_event
*))
3167 struct perf_event
*child
;
3169 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3170 mutex_lock(&event
->child_mutex
);
3172 list_for_each_entry(child
, &event
->child_list
, child_list
)
3174 mutex_unlock(&event
->child_mutex
);
3177 static void perf_event_for_each(struct perf_event
*event
,
3178 void (*func
)(struct perf_event
*))
3180 struct perf_event_context
*ctx
= event
->ctx
;
3181 struct perf_event
*sibling
;
3183 WARN_ON_ONCE(ctx
->parent_ctx
);
3184 mutex_lock(&ctx
->mutex
);
3185 event
= event
->group_leader
;
3187 perf_event_for_each_child(event
, func
);
3189 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3190 perf_event_for_each_child(event
, func
);
3191 mutex_unlock(&ctx
->mutex
);
3194 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3196 struct perf_event_context
*ctx
= event
->ctx
;
3200 if (!is_sampling_event(event
))
3203 if (copy_from_user(&value
, arg
, sizeof(value
)))
3209 raw_spin_lock_irq(&ctx
->lock
);
3210 if (event
->attr
.freq
) {
3211 if (value
> sysctl_perf_event_sample_rate
) {
3216 event
->attr
.sample_freq
= value
;
3218 event
->attr
.sample_period
= value
;
3219 event
->hw
.sample_period
= value
;
3222 raw_spin_unlock_irq(&ctx
->lock
);
3227 static const struct file_operations perf_fops
;
3229 static struct perf_event
*perf_fget_light(int fd
, int *fput_needed
)
3233 file
= fget_light(fd
, fput_needed
);
3235 return ERR_PTR(-EBADF
);
3237 if (file
->f_op
!= &perf_fops
) {
3238 fput_light(file
, *fput_needed
);
3240 return ERR_PTR(-EBADF
);
3243 return file
->private_data
;
3246 static int perf_event_set_output(struct perf_event
*event
,
3247 struct perf_event
*output_event
);
3248 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3250 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3252 struct perf_event
*event
= file
->private_data
;
3253 void (*func
)(struct perf_event
*);
3257 case PERF_EVENT_IOC_ENABLE
:
3258 func
= perf_event_enable
;
3260 case PERF_EVENT_IOC_DISABLE
:
3261 func
= perf_event_disable
;
3263 case PERF_EVENT_IOC_RESET
:
3264 func
= perf_event_reset
;
3267 case PERF_EVENT_IOC_REFRESH
:
3268 return perf_event_refresh(event
, arg
);
3270 case PERF_EVENT_IOC_PERIOD
:
3271 return perf_event_period(event
, (u64 __user
*)arg
);
3273 case PERF_EVENT_IOC_SET_OUTPUT
:
3275 struct perf_event
*output_event
= NULL
;
3276 int fput_needed
= 0;
3280 output_event
= perf_fget_light(arg
, &fput_needed
);
3281 if (IS_ERR(output_event
))
3282 return PTR_ERR(output_event
);
3285 ret
= perf_event_set_output(event
, output_event
);
3287 fput_light(output_event
->filp
, fput_needed
);
3292 case PERF_EVENT_IOC_SET_FILTER
:
3293 return perf_event_set_filter(event
, (void __user
*)arg
);
3299 if (flags
& PERF_IOC_FLAG_GROUP
)
3300 perf_event_for_each(event
, func
);
3302 perf_event_for_each_child(event
, func
);
3307 int perf_event_task_enable(void)
3309 struct perf_event
*event
;
3311 mutex_lock(¤t
->perf_event_mutex
);
3312 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3313 perf_event_for_each_child(event
, perf_event_enable
);
3314 mutex_unlock(¤t
->perf_event_mutex
);
3319 int perf_event_task_disable(void)
3321 struct perf_event
*event
;
3323 mutex_lock(¤t
->perf_event_mutex
);
3324 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3325 perf_event_for_each_child(event
, perf_event_disable
);
3326 mutex_unlock(¤t
->perf_event_mutex
);
3331 #ifndef PERF_EVENT_INDEX_OFFSET
3332 # define PERF_EVENT_INDEX_OFFSET 0
3335 static int perf_event_index(struct perf_event
*event
)
3337 if (event
->hw
.state
& PERF_HES_STOPPED
)
3340 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3343 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
3347 * Callers need to ensure there can be no nesting of this function, otherwise
3348 * the seqlock logic goes bad. We can not serialize this because the arch
3349 * code calls this from NMI context.
3351 void perf_event_update_userpage(struct perf_event
*event
)
3353 struct perf_event_mmap_page
*userpg
;
3354 struct perf_buffer
*buffer
;
3357 buffer
= rcu_dereference(event
->buffer
);
3361 userpg
= buffer
->user_page
;
3364 * Disable preemption so as to not let the corresponding user-space
3365 * spin too long if we get preempted.
3370 userpg
->index
= perf_event_index(event
);
3371 userpg
->offset
= perf_event_count(event
);
3372 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3373 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3375 userpg
->time_enabled
= event
->total_time_enabled
+
3376 atomic64_read(&event
->child_total_time_enabled
);
3378 userpg
->time_running
= event
->total_time_running
+
3379 atomic64_read(&event
->child_total_time_running
);
3388 static unsigned long perf_data_size(struct perf_buffer
*buffer
);
3391 perf_buffer_init(struct perf_buffer
*buffer
, long watermark
, int flags
)
3393 long max_size
= perf_data_size(buffer
);
3396 buffer
->watermark
= min(max_size
, watermark
);
3398 if (!buffer
->watermark
)
3399 buffer
->watermark
= max_size
/ 2;
3401 if (flags
& PERF_BUFFER_WRITABLE
)
3402 buffer
->writable
= 1;
3404 atomic_set(&buffer
->refcount
, 1);
3407 #ifndef CONFIG_PERF_USE_VMALLOC
3410 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
3413 static struct page
*
3414 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
3416 if (pgoff
> buffer
->nr_pages
)
3420 return virt_to_page(buffer
->user_page
);
3422 return virt_to_page(buffer
->data_pages
[pgoff
- 1]);
3425 static void *perf_mmap_alloc_page(int cpu
)
3430 node
= (cpu
== -1) ? cpu
: cpu_to_node(cpu
);
3431 page
= alloc_pages_node(node
, GFP_KERNEL
| __GFP_ZERO
, 0);
3435 return page_address(page
);
3438 static struct perf_buffer
*
3439 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
3441 struct perf_buffer
*buffer
;
3445 size
= sizeof(struct perf_buffer
);
3446 size
+= nr_pages
* sizeof(void *);
3448 buffer
= kzalloc(size
, GFP_KERNEL
);
3452 buffer
->user_page
= perf_mmap_alloc_page(cpu
);
3453 if (!buffer
->user_page
)
3454 goto fail_user_page
;
3456 for (i
= 0; i
< nr_pages
; i
++) {
3457 buffer
->data_pages
[i
] = perf_mmap_alloc_page(cpu
);
3458 if (!buffer
->data_pages
[i
])
3459 goto fail_data_pages
;
3462 buffer
->nr_pages
= nr_pages
;
3464 perf_buffer_init(buffer
, watermark
, flags
);
3469 for (i
--; i
>= 0; i
--)
3470 free_page((unsigned long)buffer
->data_pages
[i
]);
3472 free_page((unsigned long)buffer
->user_page
);
3481 static void perf_mmap_free_page(unsigned long addr
)
3483 struct page
*page
= virt_to_page((void *)addr
);
3485 page
->mapping
= NULL
;
3489 static void perf_buffer_free(struct perf_buffer
*buffer
)
3493 perf_mmap_free_page((unsigned long)buffer
->user_page
);
3494 for (i
= 0; i
< buffer
->nr_pages
; i
++)
3495 perf_mmap_free_page((unsigned long)buffer
->data_pages
[i
]);
3499 static inline int page_order(struct perf_buffer
*buffer
)
3507 * Back perf_mmap() with vmalloc memory.
3509 * Required for architectures that have d-cache aliasing issues.
3512 static inline int page_order(struct perf_buffer
*buffer
)
3514 return buffer
->page_order
;
3517 static struct page
*
3518 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
3520 if (pgoff
> (1UL << page_order(buffer
)))
3523 return vmalloc_to_page((void *)buffer
->user_page
+ pgoff
* PAGE_SIZE
);
3526 static void perf_mmap_unmark_page(void *addr
)
3528 struct page
*page
= vmalloc_to_page(addr
);
3530 page
->mapping
= NULL
;
3533 static void perf_buffer_free_work(struct work_struct
*work
)
3535 struct perf_buffer
*buffer
;
3539 buffer
= container_of(work
, struct perf_buffer
, work
);
3540 nr
= 1 << page_order(buffer
);
3542 base
= buffer
->user_page
;
3543 for (i
= 0; i
< nr
+ 1; i
++)
3544 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
3550 static void perf_buffer_free(struct perf_buffer
*buffer
)
3552 schedule_work(&buffer
->work
);
3555 static struct perf_buffer
*
3556 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
3558 struct perf_buffer
*buffer
;
3562 size
= sizeof(struct perf_buffer
);
3563 size
+= sizeof(void *);
3565 buffer
= kzalloc(size
, GFP_KERNEL
);
3569 INIT_WORK(&buffer
->work
, perf_buffer_free_work
);
3571 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
3575 buffer
->user_page
= all_buf
;
3576 buffer
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
3577 buffer
->page_order
= ilog2(nr_pages
);
3578 buffer
->nr_pages
= 1;
3580 perf_buffer_init(buffer
, watermark
, flags
);
3593 static unsigned long perf_data_size(struct perf_buffer
*buffer
)
3595 return buffer
->nr_pages
<< (PAGE_SHIFT
+ page_order(buffer
));
3598 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3600 struct perf_event
*event
= vma
->vm_file
->private_data
;
3601 struct perf_buffer
*buffer
;
3602 int ret
= VM_FAULT_SIGBUS
;
3604 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3605 if (vmf
->pgoff
== 0)
3611 buffer
= rcu_dereference(event
->buffer
);
3615 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3618 vmf
->page
= perf_mmap_to_page(buffer
, vmf
->pgoff
);
3622 get_page(vmf
->page
);
3623 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3624 vmf
->page
->index
= vmf
->pgoff
;
3633 static void perf_buffer_free_rcu(struct rcu_head
*rcu_head
)
3635 struct perf_buffer
*buffer
;
3637 buffer
= container_of(rcu_head
, struct perf_buffer
, rcu_head
);
3638 perf_buffer_free(buffer
);
3641 static struct perf_buffer
*perf_buffer_get(struct perf_event
*event
)
3643 struct perf_buffer
*buffer
;
3646 buffer
= rcu_dereference(event
->buffer
);
3648 if (!atomic_inc_not_zero(&buffer
->refcount
))
3656 static void perf_buffer_put(struct perf_buffer
*buffer
)
3658 if (!atomic_dec_and_test(&buffer
->refcount
))
3661 call_rcu(&buffer
->rcu_head
, perf_buffer_free_rcu
);
3664 static void perf_mmap_open(struct vm_area_struct
*vma
)
3666 struct perf_event
*event
= vma
->vm_file
->private_data
;
3668 atomic_inc(&event
->mmap_count
);
3671 static void perf_mmap_close(struct vm_area_struct
*vma
)
3673 struct perf_event
*event
= vma
->vm_file
->private_data
;
3675 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3676 unsigned long size
= perf_data_size(event
->buffer
);
3677 struct user_struct
*user
= event
->mmap_user
;
3678 struct perf_buffer
*buffer
= event
->buffer
;
3680 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3681 vma
->vm_mm
->locked_vm
-= event
->mmap_locked
;
3682 rcu_assign_pointer(event
->buffer
, NULL
);
3683 mutex_unlock(&event
->mmap_mutex
);
3685 perf_buffer_put(buffer
);
3690 static const struct vm_operations_struct perf_mmap_vmops
= {
3691 .open
= perf_mmap_open
,
3692 .close
= perf_mmap_close
,
3693 .fault
= perf_mmap_fault
,
3694 .page_mkwrite
= perf_mmap_fault
,
3697 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3699 struct perf_event
*event
= file
->private_data
;
3700 unsigned long user_locked
, user_lock_limit
;
3701 struct user_struct
*user
= current_user();
3702 unsigned long locked
, lock_limit
;
3703 struct perf_buffer
*buffer
;
3704 unsigned long vma_size
;
3705 unsigned long nr_pages
;
3706 long user_extra
, extra
;
3707 int ret
= 0, flags
= 0;
3710 * Don't allow mmap() of inherited per-task counters. This would
3711 * create a performance issue due to all children writing to the
3714 if (event
->cpu
== -1 && event
->attr
.inherit
)
3717 if (!(vma
->vm_flags
& VM_SHARED
))
3720 vma_size
= vma
->vm_end
- vma
->vm_start
;
3721 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3724 * If we have buffer pages ensure they're a power-of-two number, so we
3725 * can do bitmasks instead of modulo.
3727 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3730 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3733 if (vma
->vm_pgoff
!= 0)
3736 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3737 mutex_lock(&event
->mmap_mutex
);
3738 if (event
->buffer
) {
3739 if (event
->buffer
->nr_pages
== nr_pages
)
3740 atomic_inc(&event
->buffer
->refcount
);
3746 user_extra
= nr_pages
+ 1;
3747 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3750 * Increase the limit linearly with more CPUs:
3752 user_lock_limit
*= num_online_cpus();
3754 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3757 if (user_locked
> user_lock_limit
)
3758 extra
= user_locked
- user_lock_limit
;
3760 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3761 lock_limit
>>= PAGE_SHIFT
;
3762 locked
= vma
->vm_mm
->locked_vm
+ extra
;
3764 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3765 !capable(CAP_IPC_LOCK
)) {
3770 WARN_ON(event
->buffer
);
3772 if (vma
->vm_flags
& VM_WRITE
)
3773 flags
|= PERF_BUFFER_WRITABLE
;
3775 buffer
= perf_buffer_alloc(nr_pages
, event
->attr
.wakeup_watermark
,
3781 rcu_assign_pointer(event
->buffer
, buffer
);
3783 atomic_long_add(user_extra
, &user
->locked_vm
);
3784 event
->mmap_locked
= extra
;
3785 event
->mmap_user
= get_current_user();
3786 vma
->vm_mm
->locked_vm
+= event
->mmap_locked
;
3790 atomic_inc(&event
->mmap_count
);
3791 mutex_unlock(&event
->mmap_mutex
);
3793 vma
->vm_flags
|= VM_RESERVED
;
3794 vma
->vm_ops
= &perf_mmap_vmops
;
3799 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3801 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3802 struct perf_event
*event
= filp
->private_data
;
3805 mutex_lock(&inode
->i_mutex
);
3806 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3807 mutex_unlock(&inode
->i_mutex
);
3815 static const struct file_operations perf_fops
= {
3816 .llseek
= no_llseek
,
3817 .release
= perf_release
,
3820 .unlocked_ioctl
= perf_ioctl
,
3821 .compat_ioctl
= perf_ioctl
,
3823 .fasync
= perf_fasync
,
3829 * If there's data, ensure we set the poll() state and publish everything
3830 * to user-space before waking everybody up.
3833 void perf_event_wakeup(struct perf_event
*event
)
3835 wake_up_all(&event
->waitq
);
3837 if (event
->pending_kill
) {
3838 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3839 event
->pending_kill
= 0;
3843 static void perf_pending_event(struct irq_work
*entry
)
3845 struct perf_event
*event
= container_of(entry
,
3846 struct perf_event
, pending
);
3848 if (event
->pending_disable
) {
3849 event
->pending_disable
= 0;
3850 __perf_event_disable(event
);
3853 if (event
->pending_wakeup
) {
3854 event
->pending_wakeup
= 0;
3855 perf_event_wakeup(event
);
3860 * We assume there is only KVM supporting the callbacks.
3861 * Later on, we might change it to a list if there is
3862 * another virtualization implementation supporting the callbacks.
3864 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3866 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3868 perf_guest_cbs
= cbs
;
3871 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3873 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3875 perf_guest_cbs
= NULL
;
3878 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3883 static bool perf_output_space(struct perf_buffer
*buffer
, unsigned long tail
,
3884 unsigned long offset
, unsigned long head
)
3888 if (!buffer
->writable
)
3891 mask
= perf_data_size(buffer
) - 1;
3893 offset
= (offset
- tail
) & mask
;
3894 head
= (head
- tail
) & mask
;
3896 if ((int)(head
- offset
) < 0)
3902 static void perf_output_wakeup(struct perf_output_handle
*handle
)
3904 atomic_set(&handle
->buffer
->poll
, POLL_IN
);
3907 handle
->event
->pending_wakeup
= 1;
3908 irq_work_queue(&handle
->event
->pending
);
3910 perf_event_wakeup(handle
->event
);
3914 * We need to ensure a later event_id doesn't publish a head when a former
3915 * event isn't done writing. However since we need to deal with NMIs we
3916 * cannot fully serialize things.
3918 * We only publish the head (and generate a wakeup) when the outer-most
3921 static void perf_output_get_handle(struct perf_output_handle
*handle
)
3923 struct perf_buffer
*buffer
= handle
->buffer
;
3926 local_inc(&buffer
->nest
);
3927 handle
->wakeup
= local_read(&buffer
->wakeup
);
3930 static void perf_output_put_handle(struct perf_output_handle
*handle
)
3932 struct perf_buffer
*buffer
= handle
->buffer
;
3936 head
= local_read(&buffer
->head
);
3939 * IRQ/NMI can happen here, which means we can miss a head update.
3942 if (!local_dec_and_test(&buffer
->nest
))
3946 * Publish the known good head. Rely on the full barrier implied
3947 * by atomic_dec_and_test() order the buffer->head read and this
3950 buffer
->user_page
->data_head
= head
;
3953 * Now check if we missed an update, rely on the (compiler)
3954 * barrier in atomic_dec_and_test() to re-read buffer->head.
3956 if (unlikely(head
!= local_read(&buffer
->head
))) {
3957 local_inc(&buffer
->nest
);
3961 if (handle
->wakeup
!= local_read(&buffer
->wakeup
))
3962 perf_output_wakeup(handle
);
3968 __always_inline
void perf_output_copy(struct perf_output_handle
*handle
,
3969 const void *buf
, unsigned int len
)
3972 unsigned long size
= min_t(unsigned long, handle
->size
, len
);
3974 memcpy(handle
->addr
, buf
, size
);
3977 handle
->addr
+= size
;
3979 handle
->size
-= size
;
3980 if (!handle
->size
) {
3981 struct perf_buffer
*buffer
= handle
->buffer
;
3984 handle
->page
&= buffer
->nr_pages
- 1;
3985 handle
->addr
= buffer
->data_pages
[handle
->page
];
3986 handle
->size
= PAGE_SIZE
<< page_order(buffer
);
3991 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3992 struct perf_sample_data
*data
,
3993 struct perf_event
*event
)
3995 u64 sample_type
= event
->attr
.sample_type
;
3997 data
->type
= sample_type
;
3998 header
->size
+= event
->id_header_size
;
4000 if (sample_type
& PERF_SAMPLE_TID
) {
4001 /* namespace issues */
4002 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
4003 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
4006 if (sample_type
& PERF_SAMPLE_TIME
)
4007 data
->time
= perf_clock();
4009 if (sample_type
& PERF_SAMPLE_ID
)
4010 data
->id
= primary_event_id(event
);
4012 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4013 data
->stream_id
= event
->id
;
4015 if (sample_type
& PERF_SAMPLE_CPU
) {
4016 data
->cpu_entry
.cpu
= raw_smp_processor_id();
4017 data
->cpu_entry
.reserved
= 0;
4021 static void perf_event_header__init_id(struct perf_event_header
*header
,
4022 struct perf_sample_data
*data
,
4023 struct perf_event
*event
)
4025 if (event
->attr
.sample_id_all
)
4026 __perf_event_header__init_id(header
, data
, event
);
4029 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
4030 struct perf_sample_data
*data
)
4032 u64 sample_type
= data
->type
;
4034 if (sample_type
& PERF_SAMPLE_TID
)
4035 perf_output_put(handle
, data
->tid_entry
);
4037 if (sample_type
& PERF_SAMPLE_TIME
)
4038 perf_output_put(handle
, data
->time
);
4040 if (sample_type
& PERF_SAMPLE_ID
)
4041 perf_output_put(handle
, data
->id
);
4043 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4044 perf_output_put(handle
, data
->stream_id
);
4046 if (sample_type
& PERF_SAMPLE_CPU
)
4047 perf_output_put(handle
, data
->cpu_entry
);
4050 static void perf_event__output_id_sample(struct perf_event
*event
,
4051 struct perf_output_handle
*handle
,
4052 struct perf_sample_data
*sample
)
4054 if (event
->attr
.sample_id_all
)
4055 __perf_event__output_id_sample(handle
, sample
);
4058 int perf_output_begin(struct perf_output_handle
*handle
,
4059 struct perf_event
*event
, unsigned int size
,
4060 int nmi
, int sample
)
4062 struct perf_buffer
*buffer
;
4063 unsigned long tail
, offset
, head
;
4065 struct perf_sample_data sample_data
;
4067 struct perf_event_header header
;
4074 * For inherited events we send all the output towards the parent.
4077 event
= event
->parent
;
4079 buffer
= rcu_dereference(event
->buffer
);
4083 handle
->buffer
= buffer
;
4084 handle
->event
= event
;
4086 handle
->sample
= sample
;
4088 if (!buffer
->nr_pages
)
4091 have_lost
= local_read(&buffer
->lost
);
4093 lost_event
.header
.size
= sizeof(lost_event
);
4094 perf_event_header__init_id(&lost_event
.header
, &sample_data
,
4096 size
+= lost_event
.header
.size
;
4099 perf_output_get_handle(handle
);
4103 * Userspace could choose to issue a mb() before updating the
4104 * tail pointer. So that all reads will be completed before the
4107 tail
= ACCESS_ONCE(buffer
->user_page
->data_tail
);
4109 offset
= head
= local_read(&buffer
->head
);
4111 if (unlikely(!perf_output_space(buffer
, tail
, offset
, head
)))
4113 } while (local_cmpxchg(&buffer
->head
, offset
, head
) != offset
);
4115 if (head
- local_read(&buffer
->wakeup
) > buffer
->watermark
)
4116 local_add(buffer
->watermark
, &buffer
->wakeup
);
4118 handle
->page
= offset
>> (PAGE_SHIFT
+ page_order(buffer
));
4119 handle
->page
&= buffer
->nr_pages
- 1;
4120 handle
->size
= offset
& ((PAGE_SIZE
<< page_order(buffer
)) - 1);
4121 handle
->addr
= buffer
->data_pages
[handle
->page
];
4122 handle
->addr
+= handle
->size
;
4123 handle
->size
= (PAGE_SIZE
<< page_order(buffer
)) - handle
->size
;
4126 lost_event
.header
.type
= PERF_RECORD_LOST
;
4127 lost_event
.header
.misc
= 0;
4128 lost_event
.id
= event
->id
;
4129 lost_event
.lost
= local_xchg(&buffer
->lost
, 0);
4131 perf_output_put(handle
, lost_event
);
4132 perf_event__output_id_sample(event
, handle
, &sample_data
);
4138 local_inc(&buffer
->lost
);
4139 perf_output_put_handle(handle
);
4146 void perf_output_end(struct perf_output_handle
*handle
)
4148 struct perf_event
*event
= handle
->event
;
4149 struct perf_buffer
*buffer
= handle
->buffer
;
4151 int wakeup_events
= event
->attr
.wakeup_events
;
4153 if (handle
->sample
&& wakeup_events
) {
4154 int events
= local_inc_return(&buffer
->events
);
4155 if (events
>= wakeup_events
) {
4156 local_sub(wakeup_events
, &buffer
->events
);
4157 local_inc(&buffer
->wakeup
);
4161 perf_output_put_handle(handle
);
4165 static void perf_output_read_one(struct perf_output_handle
*handle
,
4166 struct perf_event
*event
,
4167 u64 enabled
, u64 running
)
4169 u64 read_format
= event
->attr
.read_format
;
4173 values
[n
++] = perf_event_count(event
);
4174 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4175 values
[n
++] = enabled
+
4176 atomic64_read(&event
->child_total_time_enabled
);
4178 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4179 values
[n
++] = running
+
4180 atomic64_read(&event
->child_total_time_running
);
4182 if (read_format
& PERF_FORMAT_ID
)
4183 values
[n
++] = primary_event_id(event
);
4185 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4189 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
4191 static void perf_output_read_group(struct perf_output_handle
*handle
,
4192 struct perf_event
*event
,
4193 u64 enabled
, u64 running
)
4195 struct perf_event
*leader
= event
->group_leader
, *sub
;
4196 u64 read_format
= event
->attr
.read_format
;
4200 values
[n
++] = 1 + leader
->nr_siblings
;
4202 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4203 values
[n
++] = enabled
;
4205 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4206 values
[n
++] = running
;
4208 if (leader
!= event
)
4209 leader
->pmu
->read(leader
);
4211 values
[n
++] = perf_event_count(leader
);
4212 if (read_format
& PERF_FORMAT_ID
)
4213 values
[n
++] = primary_event_id(leader
);
4215 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4217 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4221 sub
->pmu
->read(sub
);
4223 values
[n
++] = perf_event_count(sub
);
4224 if (read_format
& PERF_FORMAT_ID
)
4225 values
[n
++] = primary_event_id(sub
);
4227 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4231 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
4232 PERF_FORMAT_TOTAL_TIME_RUNNING)
4234 static void perf_output_read(struct perf_output_handle
*handle
,
4235 struct perf_event
*event
)
4237 u64 enabled
= 0, running
= 0, now
, ctx_time
;
4238 u64 read_format
= event
->attr
.read_format
;
4241 * compute total_time_enabled, total_time_running
4242 * based on snapshot values taken when the event
4243 * was last scheduled in.
4245 * we cannot simply called update_context_time()
4246 * because of locking issue as we are called in
4249 if (read_format
& PERF_FORMAT_TOTAL_TIMES
) {
4251 ctx_time
= event
->shadow_ctx_time
+ now
;
4252 enabled
= ctx_time
- event
->tstamp_enabled
;
4253 running
= ctx_time
- event
->tstamp_running
;
4256 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
4257 perf_output_read_group(handle
, event
, enabled
, running
);
4259 perf_output_read_one(handle
, event
, enabled
, running
);
4262 void perf_output_sample(struct perf_output_handle
*handle
,
4263 struct perf_event_header
*header
,
4264 struct perf_sample_data
*data
,
4265 struct perf_event
*event
)
4267 u64 sample_type
= data
->type
;
4269 perf_output_put(handle
, *header
);
4271 if (sample_type
& PERF_SAMPLE_IP
)
4272 perf_output_put(handle
, data
->ip
);
4274 if (sample_type
& PERF_SAMPLE_TID
)
4275 perf_output_put(handle
, data
->tid_entry
);
4277 if (sample_type
& PERF_SAMPLE_TIME
)
4278 perf_output_put(handle
, data
->time
);
4280 if (sample_type
& PERF_SAMPLE_ADDR
)
4281 perf_output_put(handle
, data
->addr
);
4283 if (sample_type
& PERF_SAMPLE_ID
)
4284 perf_output_put(handle
, data
->id
);
4286 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4287 perf_output_put(handle
, data
->stream_id
);
4289 if (sample_type
& PERF_SAMPLE_CPU
)
4290 perf_output_put(handle
, data
->cpu_entry
);
4292 if (sample_type
& PERF_SAMPLE_PERIOD
)
4293 perf_output_put(handle
, data
->period
);
4295 if (sample_type
& PERF_SAMPLE_READ
)
4296 perf_output_read(handle
, event
);
4298 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4299 if (data
->callchain
) {
4302 if (data
->callchain
)
4303 size
+= data
->callchain
->nr
;
4305 size
*= sizeof(u64
);
4307 perf_output_copy(handle
, data
->callchain
, size
);
4310 perf_output_put(handle
, nr
);
4314 if (sample_type
& PERF_SAMPLE_RAW
) {
4316 perf_output_put(handle
, data
->raw
->size
);
4317 perf_output_copy(handle
, data
->raw
->data
,
4324 .size
= sizeof(u32
),
4327 perf_output_put(handle
, raw
);
4332 void perf_prepare_sample(struct perf_event_header
*header
,
4333 struct perf_sample_data
*data
,
4334 struct perf_event
*event
,
4335 struct pt_regs
*regs
)
4337 u64 sample_type
= event
->attr
.sample_type
;
4339 header
->type
= PERF_RECORD_SAMPLE
;
4340 header
->size
= sizeof(*header
) + event
->header_size
;
4343 header
->misc
|= perf_misc_flags(regs
);
4345 __perf_event_header__init_id(header
, data
, event
);
4347 if (sample_type
& PERF_SAMPLE_IP
)
4348 data
->ip
= perf_instruction_pointer(regs
);
4350 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4353 data
->callchain
= perf_callchain(regs
);
4355 if (data
->callchain
)
4356 size
+= data
->callchain
->nr
;
4358 header
->size
+= size
* sizeof(u64
);
4361 if (sample_type
& PERF_SAMPLE_RAW
) {
4362 int size
= sizeof(u32
);
4365 size
+= data
->raw
->size
;
4367 size
+= sizeof(u32
);
4369 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4370 header
->size
+= size
;
4374 static void perf_event_output(struct perf_event
*event
, int nmi
,
4375 struct perf_sample_data
*data
,
4376 struct pt_regs
*regs
)
4378 struct perf_output_handle handle
;
4379 struct perf_event_header header
;
4381 /* protect the callchain buffers */
4384 perf_prepare_sample(&header
, data
, event
, regs
);
4386 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
4389 perf_output_sample(&handle
, &header
, data
, event
);
4391 perf_output_end(&handle
);
4401 struct perf_read_event
{
4402 struct perf_event_header header
;
4409 perf_event_read_event(struct perf_event
*event
,
4410 struct task_struct
*task
)
4412 struct perf_output_handle handle
;
4413 struct perf_sample_data sample
;
4414 struct perf_read_event read_event
= {
4416 .type
= PERF_RECORD_READ
,
4418 .size
= sizeof(read_event
) + event
->read_size
,
4420 .pid
= perf_event_pid(event
, task
),
4421 .tid
= perf_event_tid(event
, task
),
4425 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4426 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
4430 perf_output_put(&handle
, read_event
);
4431 perf_output_read(&handle
, event
);
4432 perf_event__output_id_sample(event
, &handle
, &sample
);
4434 perf_output_end(&handle
);
4438 * task tracking -- fork/exit
4440 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
4443 struct perf_task_event
{
4444 struct task_struct
*task
;
4445 struct perf_event_context
*task_ctx
;
4448 struct perf_event_header header
;
4458 static void perf_event_task_output(struct perf_event
*event
,
4459 struct perf_task_event
*task_event
)
4461 struct perf_output_handle handle
;
4462 struct perf_sample_data sample
;
4463 struct task_struct
*task
= task_event
->task
;
4464 int ret
, size
= task_event
->event_id
.header
.size
;
4466 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4468 ret
= perf_output_begin(&handle
, event
,
4469 task_event
->event_id
.header
.size
, 0, 0);
4473 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4474 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4476 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4477 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4479 perf_output_put(&handle
, task_event
->event_id
);
4481 perf_event__output_id_sample(event
, &handle
, &sample
);
4483 perf_output_end(&handle
);
4485 task_event
->event_id
.header
.size
= size
;
4488 static int perf_event_task_match(struct perf_event
*event
)
4490 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4493 if (!event_filter_match(event
))
4496 if (event
->attr
.comm
|| event
->attr
.mmap
||
4497 event
->attr
.mmap_data
|| event
->attr
.task
)
4503 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
4504 struct perf_task_event
*task_event
)
4506 struct perf_event
*event
;
4508 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4509 if (perf_event_task_match(event
))
4510 perf_event_task_output(event
, task_event
);
4514 static void perf_event_task_event(struct perf_task_event
*task_event
)
4516 struct perf_cpu_context
*cpuctx
;
4517 struct perf_event_context
*ctx
;
4522 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4523 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4524 if (cpuctx
->active_pmu
!= pmu
)
4526 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
4528 ctx
= task_event
->task_ctx
;
4530 ctxn
= pmu
->task_ctx_nr
;
4533 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4536 perf_event_task_ctx(ctx
, task_event
);
4538 put_cpu_ptr(pmu
->pmu_cpu_context
);
4543 static void perf_event_task(struct task_struct
*task
,
4544 struct perf_event_context
*task_ctx
,
4547 struct perf_task_event task_event
;
4549 if (!atomic_read(&nr_comm_events
) &&
4550 !atomic_read(&nr_mmap_events
) &&
4551 !atomic_read(&nr_task_events
))
4554 task_event
= (struct perf_task_event
){
4556 .task_ctx
= task_ctx
,
4559 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4561 .size
= sizeof(task_event
.event_id
),
4567 .time
= perf_clock(),
4571 perf_event_task_event(&task_event
);
4574 void perf_event_fork(struct task_struct
*task
)
4576 perf_event_task(task
, NULL
, 1);
4583 struct perf_comm_event
{
4584 struct task_struct
*task
;
4589 struct perf_event_header header
;
4596 static void perf_event_comm_output(struct perf_event
*event
,
4597 struct perf_comm_event
*comm_event
)
4599 struct perf_output_handle handle
;
4600 struct perf_sample_data sample
;
4601 int size
= comm_event
->event_id
.header
.size
;
4604 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4605 ret
= perf_output_begin(&handle
, event
,
4606 comm_event
->event_id
.header
.size
, 0, 0);
4611 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4612 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4614 perf_output_put(&handle
, comm_event
->event_id
);
4615 perf_output_copy(&handle
, comm_event
->comm
,
4616 comm_event
->comm_size
);
4618 perf_event__output_id_sample(event
, &handle
, &sample
);
4620 perf_output_end(&handle
);
4622 comm_event
->event_id
.header
.size
= size
;
4625 static int perf_event_comm_match(struct perf_event
*event
)
4627 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4630 if (!event_filter_match(event
))
4633 if (event
->attr
.comm
)
4639 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4640 struct perf_comm_event
*comm_event
)
4642 struct perf_event
*event
;
4644 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4645 if (perf_event_comm_match(event
))
4646 perf_event_comm_output(event
, comm_event
);
4650 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4652 struct perf_cpu_context
*cpuctx
;
4653 struct perf_event_context
*ctx
;
4654 char comm
[TASK_COMM_LEN
];
4659 memset(comm
, 0, sizeof(comm
));
4660 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4661 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4663 comm_event
->comm
= comm
;
4664 comm_event
->comm_size
= size
;
4666 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4668 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4669 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4670 if (cpuctx
->active_pmu
!= pmu
)
4672 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4674 ctxn
= pmu
->task_ctx_nr
;
4678 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4680 perf_event_comm_ctx(ctx
, comm_event
);
4682 put_cpu_ptr(pmu
->pmu_cpu_context
);
4687 void perf_event_comm(struct task_struct
*task
)
4689 struct perf_comm_event comm_event
;
4690 struct perf_event_context
*ctx
;
4693 for_each_task_context_nr(ctxn
) {
4694 ctx
= task
->perf_event_ctxp
[ctxn
];
4698 perf_event_enable_on_exec(ctx
);
4701 if (!atomic_read(&nr_comm_events
))
4704 comm_event
= (struct perf_comm_event
){
4710 .type
= PERF_RECORD_COMM
,
4719 perf_event_comm_event(&comm_event
);
4726 struct perf_mmap_event
{
4727 struct vm_area_struct
*vma
;
4729 const char *file_name
;
4733 struct perf_event_header header
;
4743 static void perf_event_mmap_output(struct perf_event
*event
,
4744 struct perf_mmap_event
*mmap_event
)
4746 struct perf_output_handle handle
;
4747 struct perf_sample_data sample
;
4748 int size
= mmap_event
->event_id
.header
.size
;
4751 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4752 ret
= perf_output_begin(&handle
, event
,
4753 mmap_event
->event_id
.header
.size
, 0, 0);
4757 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4758 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4760 perf_output_put(&handle
, mmap_event
->event_id
);
4761 perf_output_copy(&handle
, mmap_event
->file_name
,
4762 mmap_event
->file_size
);
4764 perf_event__output_id_sample(event
, &handle
, &sample
);
4766 perf_output_end(&handle
);
4768 mmap_event
->event_id
.header
.size
= size
;
4771 static int perf_event_mmap_match(struct perf_event
*event
,
4772 struct perf_mmap_event
*mmap_event
,
4775 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4778 if (!event_filter_match(event
))
4781 if ((!executable
&& event
->attr
.mmap_data
) ||
4782 (executable
&& event
->attr
.mmap
))
4788 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4789 struct perf_mmap_event
*mmap_event
,
4792 struct perf_event
*event
;
4794 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4795 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4796 perf_event_mmap_output(event
, mmap_event
);
4800 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4802 struct perf_cpu_context
*cpuctx
;
4803 struct perf_event_context
*ctx
;
4804 struct vm_area_struct
*vma
= mmap_event
->vma
;
4805 struct file
*file
= vma
->vm_file
;
4813 memset(tmp
, 0, sizeof(tmp
));
4817 * d_path works from the end of the buffer backwards, so we
4818 * need to add enough zero bytes after the string to handle
4819 * the 64bit alignment we do later.
4821 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4823 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4826 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4828 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4832 if (arch_vma_name(mmap_event
->vma
)) {
4833 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4839 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4841 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4842 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4843 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4845 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4846 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4847 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4851 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4856 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4858 mmap_event
->file_name
= name
;
4859 mmap_event
->file_size
= size
;
4861 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4864 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4865 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4866 if (cpuctx
->active_pmu
!= pmu
)
4868 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4869 vma
->vm_flags
& VM_EXEC
);
4871 ctxn
= pmu
->task_ctx_nr
;
4875 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4877 perf_event_mmap_ctx(ctx
, mmap_event
,
4878 vma
->vm_flags
& VM_EXEC
);
4881 put_cpu_ptr(pmu
->pmu_cpu_context
);
4888 void perf_event_mmap(struct vm_area_struct
*vma
)
4890 struct perf_mmap_event mmap_event
;
4892 if (!atomic_read(&nr_mmap_events
))
4895 mmap_event
= (struct perf_mmap_event
){
4901 .type
= PERF_RECORD_MMAP
,
4902 .misc
= PERF_RECORD_MISC_USER
,
4907 .start
= vma
->vm_start
,
4908 .len
= vma
->vm_end
- vma
->vm_start
,
4909 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4913 perf_event_mmap_event(&mmap_event
);
4917 * IRQ throttle logging
4920 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4922 struct perf_output_handle handle
;
4923 struct perf_sample_data sample
;
4927 struct perf_event_header header
;
4931 } throttle_event
= {
4933 .type
= PERF_RECORD_THROTTLE
,
4935 .size
= sizeof(throttle_event
),
4937 .time
= perf_clock(),
4938 .id
= primary_event_id(event
),
4939 .stream_id
= event
->id
,
4943 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4945 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4947 ret
= perf_output_begin(&handle
, event
,
4948 throttle_event
.header
.size
, 1, 0);
4952 perf_output_put(&handle
, throttle_event
);
4953 perf_event__output_id_sample(event
, &handle
, &sample
);
4954 perf_output_end(&handle
);
4958 * Generic event overflow handling, sampling.
4961 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
4962 int throttle
, struct perf_sample_data
*data
,
4963 struct pt_regs
*regs
)
4965 int events
= atomic_read(&event
->event_limit
);
4966 struct hw_perf_event
*hwc
= &event
->hw
;
4970 * Non-sampling counters might still use the PMI to fold short
4971 * hardware counters, ignore those.
4973 if (unlikely(!is_sampling_event(event
)))
4976 if (unlikely(hwc
->interrupts
>= max_samples_per_tick
)) {
4978 hwc
->interrupts
= MAX_INTERRUPTS
;
4979 perf_log_throttle(event
, 0);
4985 if (event
->attr
.freq
) {
4986 u64 now
= perf_clock();
4987 s64 delta
= now
- hwc
->freq_time_stamp
;
4989 hwc
->freq_time_stamp
= now
;
4991 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4992 perf_adjust_period(event
, delta
, hwc
->last_period
);
4996 * XXX event_limit might not quite work as expected on inherited
5000 event
->pending_kill
= POLL_IN
;
5001 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
5003 event
->pending_kill
= POLL_HUP
;
5005 event
->pending_disable
= 1;
5006 irq_work_queue(&event
->pending
);
5008 perf_event_disable(event
);
5011 if (event
->overflow_handler
)
5012 event
->overflow_handler(event
, nmi
, data
, regs
);
5014 perf_event_output(event
, nmi
, data
, regs
);
5019 int perf_event_overflow(struct perf_event
*event
, int nmi
,
5020 struct perf_sample_data
*data
,
5021 struct pt_regs
*regs
)
5023 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
5027 * Generic software event infrastructure
5030 struct swevent_htable
{
5031 struct swevent_hlist
*swevent_hlist
;
5032 struct mutex hlist_mutex
;
5035 /* Recursion avoidance in each contexts */
5036 int recursion
[PERF_NR_CONTEXTS
];
5039 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
5042 * We directly increment event->count and keep a second value in
5043 * event->hw.period_left to count intervals. This period event
5044 * is kept in the range [-sample_period, 0] so that we can use the
5048 static u64
perf_swevent_set_period(struct perf_event
*event
)
5050 struct hw_perf_event
*hwc
= &event
->hw
;
5051 u64 period
= hwc
->last_period
;
5055 hwc
->last_period
= hwc
->sample_period
;
5058 old
= val
= local64_read(&hwc
->period_left
);
5062 nr
= div64_u64(period
+ val
, period
);
5063 offset
= nr
* period
;
5065 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
5071 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
5072 int nmi
, struct perf_sample_data
*data
,
5073 struct pt_regs
*regs
)
5075 struct hw_perf_event
*hwc
= &event
->hw
;
5078 data
->period
= event
->hw
.last_period
;
5080 overflow
= perf_swevent_set_period(event
);
5082 if (hwc
->interrupts
== MAX_INTERRUPTS
)
5085 for (; overflow
; overflow
--) {
5086 if (__perf_event_overflow(event
, nmi
, throttle
,
5089 * We inhibit the overflow from happening when
5090 * hwc->interrupts == MAX_INTERRUPTS.
5098 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
5099 int nmi
, struct perf_sample_data
*data
,
5100 struct pt_regs
*regs
)
5102 struct hw_perf_event
*hwc
= &event
->hw
;
5104 local64_add(nr
, &event
->count
);
5109 if (!is_sampling_event(event
))
5112 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
5113 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
5115 if (local64_add_negative(nr
, &hwc
->period_left
))
5118 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
5121 static int perf_exclude_event(struct perf_event
*event
,
5122 struct pt_regs
*regs
)
5124 if (event
->hw
.state
& PERF_HES_STOPPED
)
5128 if (event
->attr
.exclude_user
&& user_mode(regs
))
5131 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
5138 static int perf_swevent_match(struct perf_event
*event
,
5139 enum perf_type_id type
,
5141 struct perf_sample_data
*data
,
5142 struct pt_regs
*regs
)
5144 if (event
->attr
.type
!= type
)
5147 if (event
->attr
.config
!= event_id
)
5150 if (perf_exclude_event(event
, regs
))
5156 static inline u64
swevent_hash(u64 type
, u32 event_id
)
5158 u64 val
= event_id
| (type
<< 32);
5160 return hash_64(val
, SWEVENT_HLIST_BITS
);
5163 static inline struct hlist_head
*
5164 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
5166 u64 hash
= swevent_hash(type
, event_id
);
5168 return &hlist
->heads
[hash
];
5171 /* For the read side: events when they trigger */
5172 static inline struct hlist_head
*
5173 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
5175 struct swevent_hlist
*hlist
;
5177 hlist
= rcu_dereference(swhash
->swevent_hlist
);
5181 return __find_swevent_head(hlist
, type
, event_id
);
5184 /* For the event head insertion and removal in the hlist */
5185 static inline struct hlist_head
*
5186 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
5188 struct swevent_hlist
*hlist
;
5189 u32 event_id
= event
->attr
.config
;
5190 u64 type
= event
->attr
.type
;
5193 * Event scheduling is always serialized against hlist allocation
5194 * and release. Which makes the protected version suitable here.
5195 * The context lock guarantees that.
5197 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
5198 lockdep_is_held(&event
->ctx
->lock
));
5202 return __find_swevent_head(hlist
, type
, event_id
);
5205 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
5207 struct perf_sample_data
*data
,
5208 struct pt_regs
*regs
)
5210 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5211 struct perf_event
*event
;
5212 struct hlist_node
*node
;
5213 struct hlist_head
*head
;
5216 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
5220 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5221 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
5222 perf_swevent_event(event
, nr
, nmi
, data
, regs
);
5228 int perf_swevent_get_recursion_context(void)
5230 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5232 return get_recursion_context(swhash
->recursion
);
5234 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
5236 inline void perf_swevent_put_recursion_context(int rctx
)
5238 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5240 put_recursion_context(swhash
->recursion
, rctx
);
5243 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
5244 struct pt_regs
*regs
, u64 addr
)
5246 struct perf_sample_data data
;
5249 preempt_disable_notrace();
5250 rctx
= perf_swevent_get_recursion_context();
5254 perf_sample_data_init(&data
, addr
);
5256 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
5258 perf_swevent_put_recursion_context(rctx
);
5259 preempt_enable_notrace();
5262 static void perf_swevent_read(struct perf_event
*event
)
5266 static int perf_swevent_add(struct perf_event
*event
, int flags
)
5268 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5269 struct hw_perf_event
*hwc
= &event
->hw
;
5270 struct hlist_head
*head
;
5272 if (is_sampling_event(event
)) {
5273 hwc
->last_period
= hwc
->sample_period
;
5274 perf_swevent_set_period(event
);
5277 hwc
->state
= !(flags
& PERF_EF_START
);
5279 head
= find_swevent_head(swhash
, event
);
5280 if (WARN_ON_ONCE(!head
))
5283 hlist_add_head_rcu(&event
->hlist_entry
, head
);
5288 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5290 hlist_del_rcu(&event
->hlist_entry
);
5293 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5295 event
->hw
.state
= 0;
5298 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5300 event
->hw
.state
= PERF_HES_STOPPED
;
5303 /* Deref the hlist from the update side */
5304 static inline struct swevent_hlist
*
5305 swevent_hlist_deref(struct swevent_htable
*swhash
)
5307 return rcu_dereference_protected(swhash
->swevent_hlist
,
5308 lockdep_is_held(&swhash
->hlist_mutex
));
5311 static void swevent_hlist_release_rcu(struct rcu_head
*rcu_head
)
5313 struct swevent_hlist
*hlist
;
5315 hlist
= container_of(rcu_head
, struct swevent_hlist
, rcu_head
);
5319 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5321 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5326 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5327 call_rcu(&hlist
->rcu_head
, swevent_hlist_release_rcu
);
5330 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5332 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5334 mutex_lock(&swhash
->hlist_mutex
);
5336 if (!--swhash
->hlist_refcount
)
5337 swevent_hlist_release(swhash
);
5339 mutex_unlock(&swhash
->hlist_mutex
);
5342 static void swevent_hlist_put(struct perf_event
*event
)
5346 if (event
->cpu
!= -1) {
5347 swevent_hlist_put_cpu(event
, event
->cpu
);
5351 for_each_possible_cpu(cpu
)
5352 swevent_hlist_put_cpu(event
, cpu
);
5355 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5357 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5360 mutex_lock(&swhash
->hlist_mutex
);
5362 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5363 struct swevent_hlist
*hlist
;
5365 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5370 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5372 swhash
->hlist_refcount
++;
5374 mutex_unlock(&swhash
->hlist_mutex
);
5379 static int swevent_hlist_get(struct perf_event
*event
)
5382 int cpu
, failed_cpu
;
5384 if (event
->cpu
!= -1)
5385 return swevent_hlist_get_cpu(event
, event
->cpu
);
5388 for_each_possible_cpu(cpu
) {
5389 err
= swevent_hlist_get_cpu(event
, cpu
);
5399 for_each_possible_cpu(cpu
) {
5400 if (cpu
== failed_cpu
)
5402 swevent_hlist_put_cpu(event
, cpu
);
5409 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5411 static void sw_perf_event_destroy(struct perf_event
*event
)
5413 u64 event_id
= event
->attr
.config
;
5415 WARN_ON(event
->parent
);
5417 jump_label_dec(&perf_swevent_enabled
[event_id
]);
5418 swevent_hlist_put(event
);
5421 static int perf_swevent_init(struct perf_event
*event
)
5423 int event_id
= event
->attr
.config
;
5425 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5429 case PERF_COUNT_SW_CPU_CLOCK
:
5430 case PERF_COUNT_SW_TASK_CLOCK
:
5437 if (event_id
>= PERF_COUNT_SW_MAX
)
5440 if (!event
->parent
) {
5443 err
= swevent_hlist_get(event
);
5447 jump_label_inc(&perf_swevent_enabled
[event_id
]);
5448 event
->destroy
= sw_perf_event_destroy
;
5454 static struct pmu perf_swevent
= {
5455 .task_ctx_nr
= perf_sw_context
,
5457 .event_init
= perf_swevent_init
,
5458 .add
= perf_swevent_add
,
5459 .del
= perf_swevent_del
,
5460 .start
= perf_swevent_start
,
5461 .stop
= perf_swevent_stop
,
5462 .read
= perf_swevent_read
,
5465 #ifdef CONFIG_EVENT_TRACING
5467 static int perf_tp_filter_match(struct perf_event
*event
,
5468 struct perf_sample_data
*data
)
5470 void *record
= data
->raw
->data
;
5472 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5477 static int perf_tp_event_match(struct perf_event
*event
,
5478 struct perf_sample_data
*data
,
5479 struct pt_regs
*regs
)
5482 * All tracepoints are from kernel-space.
5484 if (event
->attr
.exclude_kernel
)
5487 if (!perf_tp_filter_match(event
, data
))
5493 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5494 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
5496 struct perf_sample_data data
;
5497 struct perf_event
*event
;
5498 struct hlist_node
*node
;
5500 struct perf_raw_record raw
= {
5505 perf_sample_data_init(&data
, addr
);
5508 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5509 if (perf_tp_event_match(event
, &data
, regs
))
5510 perf_swevent_event(event
, count
, 1, &data
, regs
);
5513 perf_swevent_put_recursion_context(rctx
);
5515 EXPORT_SYMBOL_GPL(perf_tp_event
);
5517 static void tp_perf_event_destroy(struct perf_event
*event
)
5519 perf_trace_destroy(event
);
5522 static int perf_tp_event_init(struct perf_event
*event
)
5526 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5529 err
= perf_trace_init(event
);
5533 event
->destroy
= tp_perf_event_destroy
;
5538 static struct pmu perf_tracepoint
= {
5539 .task_ctx_nr
= perf_sw_context
,
5541 .event_init
= perf_tp_event_init
,
5542 .add
= perf_trace_add
,
5543 .del
= perf_trace_del
,
5544 .start
= perf_swevent_start
,
5545 .stop
= perf_swevent_stop
,
5546 .read
= perf_swevent_read
,
5549 static inline void perf_tp_register(void)
5551 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5554 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5559 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5562 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5563 if (IS_ERR(filter_str
))
5564 return PTR_ERR(filter_str
);
5566 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5572 static void perf_event_free_filter(struct perf_event
*event
)
5574 ftrace_profile_free_filter(event
);
5579 static inline void perf_tp_register(void)
5583 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5588 static void perf_event_free_filter(struct perf_event
*event
)
5592 #endif /* CONFIG_EVENT_TRACING */
5594 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5595 void perf_bp_event(struct perf_event
*bp
, void *data
)
5597 struct perf_sample_data sample
;
5598 struct pt_regs
*regs
= data
;
5600 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
5602 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5603 perf_swevent_event(bp
, 1, 1, &sample
, regs
);
5608 * hrtimer based swevent callback
5611 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5613 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5614 struct perf_sample_data data
;
5615 struct pt_regs
*regs
;
5616 struct perf_event
*event
;
5619 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5621 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5622 return HRTIMER_NORESTART
;
5624 event
->pmu
->read(event
);
5626 perf_sample_data_init(&data
, 0);
5627 data
.period
= event
->hw
.last_period
;
5628 regs
= get_irq_regs();
5630 if (regs
&& !perf_exclude_event(event
, regs
)) {
5631 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
5632 if (perf_event_overflow(event
, 0, &data
, regs
))
5633 ret
= HRTIMER_NORESTART
;
5636 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5637 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5642 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5644 struct hw_perf_event
*hwc
= &event
->hw
;
5647 if (!is_sampling_event(event
))
5650 period
= local64_read(&hwc
->period_left
);
5655 local64_set(&hwc
->period_left
, 0);
5657 period
= max_t(u64
, 10000, hwc
->sample_period
);
5659 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5660 ns_to_ktime(period
), 0,
5661 HRTIMER_MODE_REL_PINNED
, 0);
5664 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5666 struct hw_perf_event
*hwc
= &event
->hw
;
5668 if (is_sampling_event(event
)) {
5669 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5670 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5672 hrtimer_cancel(&hwc
->hrtimer
);
5676 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
5678 struct hw_perf_event
*hwc
= &event
->hw
;
5680 if (!is_sampling_event(event
))
5683 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5684 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5687 * Since hrtimers have a fixed rate, we can do a static freq->period
5688 * mapping and avoid the whole period adjust feedback stuff.
5690 if (event
->attr
.freq
) {
5691 long freq
= event
->attr
.sample_freq
;
5693 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
5694 hwc
->sample_period
= event
->attr
.sample_period
;
5695 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5696 event
->attr
.freq
= 0;
5701 * Software event: cpu wall time clock
5704 static void cpu_clock_event_update(struct perf_event
*event
)
5709 now
= local_clock();
5710 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5711 local64_add(now
- prev
, &event
->count
);
5714 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5716 local64_set(&event
->hw
.prev_count
, local_clock());
5717 perf_swevent_start_hrtimer(event
);
5720 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5722 perf_swevent_cancel_hrtimer(event
);
5723 cpu_clock_event_update(event
);
5726 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5728 if (flags
& PERF_EF_START
)
5729 cpu_clock_event_start(event
, flags
);
5734 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5736 cpu_clock_event_stop(event
, flags
);
5739 static void cpu_clock_event_read(struct perf_event
*event
)
5741 cpu_clock_event_update(event
);
5744 static int cpu_clock_event_init(struct perf_event
*event
)
5746 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5749 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5752 perf_swevent_init_hrtimer(event
);
5757 static struct pmu perf_cpu_clock
= {
5758 .task_ctx_nr
= perf_sw_context
,
5760 .event_init
= cpu_clock_event_init
,
5761 .add
= cpu_clock_event_add
,
5762 .del
= cpu_clock_event_del
,
5763 .start
= cpu_clock_event_start
,
5764 .stop
= cpu_clock_event_stop
,
5765 .read
= cpu_clock_event_read
,
5769 * Software event: task time clock
5772 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5777 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5779 local64_add(delta
, &event
->count
);
5782 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5784 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5785 perf_swevent_start_hrtimer(event
);
5788 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5790 perf_swevent_cancel_hrtimer(event
);
5791 task_clock_event_update(event
, event
->ctx
->time
);
5794 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5796 if (flags
& PERF_EF_START
)
5797 task_clock_event_start(event
, flags
);
5802 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5804 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5807 static void task_clock_event_read(struct perf_event
*event
)
5809 u64 now
= perf_clock();
5810 u64 delta
= now
- event
->ctx
->timestamp
;
5811 u64 time
= event
->ctx
->time
+ delta
;
5813 task_clock_event_update(event
, time
);
5816 static int task_clock_event_init(struct perf_event
*event
)
5818 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5821 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5824 perf_swevent_init_hrtimer(event
);
5829 static struct pmu perf_task_clock
= {
5830 .task_ctx_nr
= perf_sw_context
,
5832 .event_init
= task_clock_event_init
,
5833 .add
= task_clock_event_add
,
5834 .del
= task_clock_event_del
,
5835 .start
= task_clock_event_start
,
5836 .stop
= task_clock_event_stop
,
5837 .read
= task_clock_event_read
,
5840 static void perf_pmu_nop_void(struct pmu
*pmu
)
5844 static int perf_pmu_nop_int(struct pmu
*pmu
)
5849 static void perf_pmu_start_txn(struct pmu
*pmu
)
5851 perf_pmu_disable(pmu
);
5854 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5856 perf_pmu_enable(pmu
);
5860 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5862 perf_pmu_enable(pmu
);
5866 * Ensures all contexts with the same task_ctx_nr have the same
5867 * pmu_cpu_context too.
5869 static void *find_pmu_context(int ctxn
)
5876 list_for_each_entry(pmu
, &pmus
, entry
) {
5877 if (pmu
->task_ctx_nr
== ctxn
)
5878 return pmu
->pmu_cpu_context
;
5884 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5888 for_each_possible_cpu(cpu
) {
5889 struct perf_cpu_context
*cpuctx
;
5891 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5893 if (cpuctx
->active_pmu
== old_pmu
)
5894 cpuctx
->active_pmu
= pmu
;
5898 static void free_pmu_context(struct pmu
*pmu
)
5902 mutex_lock(&pmus_lock
);
5904 * Like a real lame refcount.
5906 list_for_each_entry(i
, &pmus
, entry
) {
5907 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5908 update_pmu_context(i
, pmu
);
5913 free_percpu(pmu
->pmu_cpu_context
);
5915 mutex_unlock(&pmus_lock
);
5917 static struct idr pmu_idr
;
5920 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5922 struct pmu
*pmu
= dev_get_drvdata(dev
);
5924 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5927 static struct device_attribute pmu_dev_attrs
[] = {
5932 static int pmu_bus_running
;
5933 static struct bus_type pmu_bus
= {
5934 .name
= "event_source",
5935 .dev_attrs
= pmu_dev_attrs
,
5938 static void pmu_dev_release(struct device
*dev
)
5943 static int pmu_dev_alloc(struct pmu
*pmu
)
5947 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5951 device_initialize(pmu
->dev
);
5952 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5956 dev_set_drvdata(pmu
->dev
, pmu
);
5957 pmu
->dev
->bus
= &pmu_bus
;
5958 pmu
->dev
->release
= pmu_dev_release
;
5959 ret
= device_add(pmu
->dev
);
5967 put_device(pmu
->dev
);
5971 static struct lock_class_key cpuctx_mutex
;
5973 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5977 mutex_lock(&pmus_lock
);
5979 pmu
->pmu_disable_count
= alloc_percpu(int);
5980 if (!pmu
->pmu_disable_count
)
5989 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
5993 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
6001 if (pmu_bus_running
) {
6002 ret
= pmu_dev_alloc(pmu
);
6008 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
6009 if (pmu
->pmu_cpu_context
)
6010 goto got_cpu_context
;
6012 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
6013 if (!pmu
->pmu_cpu_context
)
6016 for_each_possible_cpu(cpu
) {
6017 struct perf_cpu_context
*cpuctx
;
6019 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6020 __perf_event_init_context(&cpuctx
->ctx
);
6021 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
6022 cpuctx
->ctx
.type
= cpu_context
;
6023 cpuctx
->ctx
.pmu
= pmu
;
6024 cpuctx
->jiffies_interval
= 1;
6025 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
6026 cpuctx
->active_pmu
= pmu
;
6030 if (!pmu
->start_txn
) {
6031 if (pmu
->pmu_enable
) {
6033 * If we have pmu_enable/pmu_disable calls, install
6034 * transaction stubs that use that to try and batch
6035 * hardware accesses.
6037 pmu
->start_txn
= perf_pmu_start_txn
;
6038 pmu
->commit_txn
= perf_pmu_commit_txn
;
6039 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
6041 pmu
->start_txn
= perf_pmu_nop_void
;
6042 pmu
->commit_txn
= perf_pmu_nop_int
;
6043 pmu
->cancel_txn
= perf_pmu_nop_void
;
6047 if (!pmu
->pmu_enable
) {
6048 pmu
->pmu_enable
= perf_pmu_nop_void
;
6049 pmu
->pmu_disable
= perf_pmu_nop_void
;
6052 list_add_rcu(&pmu
->entry
, &pmus
);
6055 mutex_unlock(&pmus_lock
);
6060 device_del(pmu
->dev
);
6061 put_device(pmu
->dev
);
6064 if (pmu
->type
>= PERF_TYPE_MAX
)
6065 idr_remove(&pmu_idr
, pmu
->type
);
6068 free_percpu(pmu
->pmu_disable_count
);
6072 void perf_pmu_unregister(struct pmu
*pmu
)
6074 mutex_lock(&pmus_lock
);
6075 list_del_rcu(&pmu
->entry
);
6076 mutex_unlock(&pmus_lock
);
6079 * We dereference the pmu list under both SRCU and regular RCU, so
6080 * synchronize against both of those.
6082 synchronize_srcu(&pmus_srcu
);
6085 free_percpu(pmu
->pmu_disable_count
);
6086 if (pmu
->type
>= PERF_TYPE_MAX
)
6087 idr_remove(&pmu_idr
, pmu
->type
);
6088 device_del(pmu
->dev
);
6089 put_device(pmu
->dev
);
6090 free_pmu_context(pmu
);
6093 struct pmu
*perf_init_event(struct perf_event
*event
)
6095 struct pmu
*pmu
= NULL
;
6099 idx
= srcu_read_lock(&pmus_srcu
);
6102 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
6105 ret
= pmu
->event_init(event
);
6111 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6112 ret
= pmu
->event_init(event
);
6116 if (ret
!= -ENOENT
) {
6121 pmu
= ERR_PTR(-ENOENT
);
6123 srcu_read_unlock(&pmus_srcu
, idx
);
6129 * Allocate and initialize a event structure
6131 static struct perf_event
*
6132 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
6133 struct task_struct
*task
,
6134 struct perf_event
*group_leader
,
6135 struct perf_event
*parent_event
,
6136 perf_overflow_handler_t overflow_handler
)
6139 struct perf_event
*event
;
6140 struct hw_perf_event
*hwc
;
6143 if ((unsigned)cpu
>= nr_cpu_ids
) {
6144 if (!task
|| cpu
!= -1)
6145 return ERR_PTR(-EINVAL
);
6148 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
6150 return ERR_PTR(-ENOMEM
);
6153 * Single events are their own group leaders, with an
6154 * empty sibling list:
6157 group_leader
= event
;
6159 mutex_init(&event
->child_mutex
);
6160 INIT_LIST_HEAD(&event
->child_list
);
6162 INIT_LIST_HEAD(&event
->group_entry
);
6163 INIT_LIST_HEAD(&event
->event_entry
);
6164 INIT_LIST_HEAD(&event
->sibling_list
);
6165 init_waitqueue_head(&event
->waitq
);
6166 init_irq_work(&event
->pending
, perf_pending_event
);
6168 mutex_init(&event
->mmap_mutex
);
6171 event
->attr
= *attr
;
6172 event
->group_leader
= group_leader
;
6176 event
->parent
= parent_event
;
6178 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
6179 event
->id
= atomic64_inc_return(&perf_event_id
);
6181 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6184 event
->attach_state
= PERF_ATTACH_TASK
;
6185 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6187 * hw_breakpoint is a bit difficult here..
6189 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
6190 event
->hw
.bp_target
= task
;
6194 if (!overflow_handler
&& parent_event
)
6195 overflow_handler
= parent_event
->overflow_handler
;
6197 event
->overflow_handler
= overflow_handler
;
6200 event
->state
= PERF_EVENT_STATE_OFF
;
6205 hwc
->sample_period
= attr
->sample_period
;
6206 if (attr
->freq
&& attr
->sample_freq
)
6207 hwc
->sample_period
= 1;
6208 hwc
->last_period
= hwc
->sample_period
;
6210 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6213 * we currently do not support PERF_FORMAT_GROUP on inherited events
6215 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
6218 pmu
= perf_init_event(event
);
6224 else if (IS_ERR(pmu
))
6229 put_pid_ns(event
->ns
);
6231 return ERR_PTR(err
);
6236 if (!event
->parent
) {
6237 if (event
->attach_state
& PERF_ATTACH_TASK
)
6238 jump_label_inc(&perf_sched_events
);
6239 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
6240 atomic_inc(&nr_mmap_events
);
6241 if (event
->attr
.comm
)
6242 atomic_inc(&nr_comm_events
);
6243 if (event
->attr
.task
)
6244 atomic_inc(&nr_task_events
);
6245 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6246 err
= get_callchain_buffers();
6249 return ERR_PTR(err
);
6257 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6258 struct perf_event_attr
*attr
)
6263 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6267 * zero the full structure, so that a short copy will be nice.
6269 memset(attr
, 0, sizeof(*attr
));
6271 ret
= get_user(size
, &uattr
->size
);
6275 if (size
> PAGE_SIZE
) /* silly large */
6278 if (!size
) /* abi compat */
6279 size
= PERF_ATTR_SIZE_VER0
;
6281 if (size
< PERF_ATTR_SIZE_VER0
)
6285 * If we're handed a bigger struct than we know of,
6286 * ensure all the unknown bits are 0 - i.e. new
6287 * user-space does not rely on any kernel feature
6288 * extensions we dont know about yet.
6290 if (size
> sizeof(*attr
)) {
6291 unsigned char __user
*addr
;
6292 unsigned char __user
*end
;
6295 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6296 end
= (void __user
*)uattr
+ size
;
6298 for (; addr
< end
; addr
++) {
6299 ret
= get_user(val
, addr
);
6305 size
= sizeof(*attr
);
6308 ret
= copy_from_user(attr
, uattr
, size
);
6313 * If the type exists, the corresponding creation will verify
6316 if (attr
->type
>= PERF_TYPE_MAX
)
6319 if (attr
->__reserved_1
)
6322 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6325 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6332 put_user(sizeof(*attr
), &uattr
->size
);
6338 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
6340 struct perf_buffer
*buffer
= NULL
, *old_buffer
= NULL
;
6346 /* don't allow circular references */
6347 if (event
== output_event
)
6351 * Don't allow cross-cpu buffers
6353 if (output_event
->cpu
!= event
->cpu
)
6357 * If its not a per-cpu buffer, it must be the same task.
6359 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
6363 mutex_lock(&event
->mmap_mutex
);
6364 /* Can't redirect output if we've got an active mmap() */
6365 if (atomic_read(&event
->mmap_count
))
6369 /* get the buffer we want to redirect to */
6370 buffer
= perf_buffer_get(output_event
);
6375 old_buffer
= event
->buffer
;
6376 rcu_assign_pointer(event
->buffer
, buffer
);
6379 mutex_unlock(&event
->mmap_mutex
);
6382 perf_buffer_put(old_buffer
);
6388 * sys_perf_event_open - open a performance event, associate it to a task/cpu
6390 * @attr_uptr: event_id type attributes for monitoring/sampling
6393 * @group_fd: group leader event fd
6395 SYSCALL_DEFINE5(perf_event_open
,
6396 struct perf_event_attr __user
*, attr_uptr
,
6397 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
6399 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
6400 struct perf_event
*event
, *sibling
;
6401 struct perf_event_attr attr
;
6402 struct perf_event_context
*ctx
;
6403 struct file
*event_file
= NULL
;
6404 struct file
*group_file
= NULL
;
6405 struct task_struct
*task
= NULL
;
6409 int fput_needed
= 0;
6412 /* for future expandability... */
6413 if (flags
& ~PERF_FLAG_ALL
)
6416 err
= perf_copy_attr(attr_uptr
, &attr
);
6420 if (!attr
.exclude_kernel
) {
6421 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6426 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
6431 * In cgroup mode, the pid argument is used to pass the fd
6432 * opened to the cgroup directory in cgroupfs. The cpu argument
6433 * designates the cpu on which to monitor threads from that
6436 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
6439 event_fd
= get_unused_fd_flags(O_RDWR
);
6443 if (group_fd
!= -1) {
6444 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
6445 if (IS_ERR(group_leader
)) {
6446 err
= PTR_ERR(group_leader
);
6449 group_file
= group_leader
->filp
;
6450 if (flags
& PERF_FLAG_FD_OUTPUT
)
6451 output_event
= group_leader
;
6452 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6453 group_leader
= NULL
;
6456 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6457 task
= find_lively_task_by_vpid(pid
);
6459 err
= PTR_ERR(task
);
6464 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
, NULL
);
6465 if (IS_ERR(event
)) {
6466 err
= PTR_ERR(event
);
6470 if (flags
& PERF_FLAG_PID_CGROUP
) {
6471 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6476 * - that has cgroup constraint on event->cpu
6477 * - that may need work on context switch
6479 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
6480 jump_label_inc(&perf_sched_events
);
6484 * Special case software events and allow them to be part of
6485 * any hardware group.
6490 (is_software_event(event
) != is_software_event(group_leader
))) {
6491 if (is_software_event(event
)) {
6493 * If event and group_leader are not both a software
6494 * event, and event is, then group leader is not.
6496 * Allow the addition of software events to !software
6497 * groups, this is safe because software events never
6500 pmu
= group_leader
->pmu
;
6501 } else if (is_software_event(group_leader
) &&
6502 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6504 * In case the group is a pure software group, and we
6505 * try to add a hardware event, move the whole group to
6506 * the hardware context.
6513 * Get the target context (task or percpu):
6515 ctx
= find_get_context(pmu
, task
, cpu
);
6522 * Look up the group leader (we will attach this event to it):
6528 * Do not allow a recursive hierarchy (this new sibling
6529 * becoming part of another group-sibling):
6531 if (group_leader
->group_leader
!= group_leader
)
6534 * Do not allow to attach to a group in a different
6535 * task or CPU context:
6538 if (group_leader
->ctx
->type
!= ctx
->type
)
6541 if (group_leader
->ctx
!= ctx
)
6546 * Only a group leader can be exclusive or pinned
6548 if (attr
.exclusive
|| attr
.pinned
)
6553 err
= perf_event_set_output(event
, output_event
);
6558 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6559 if (IS_ERR(event_file
)) {
6560 err
= PTR_ERR(event_file
);
6565 struct perf_event_context
*gctx
= group_leader
->ctx
;
6567 mutex_lock(&gctx
->mutex
);
6568 perf_remove_from_context(group_leader
);
6569 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6571 perf_remove_from_context(sibling
);
6574 mutex_unlock(&gctx
->mutex
);
6578 event
->filp
= event_file
;
6579 WARN_ON_ONCE(ctx
->parent_ctx
);
6580 mutex_lock(&ctx
->mutex
);
6583 perf_install_in_context(ctx
, group_leader
, cpu
);
6585 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6587 perf_install_in_context(ctx
, sibling
, cpu
);
6592 perf_install_in_context(ctx
, event
, cpu
);
6594 perf_unpin_context(ctx
);
6595 mutex_unlock(&ctx
->mutex
);
6597 event
->owner
= current
;
6599 mutex_lock(¤t
->perf_event_mutex
);
6600 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6601 mutex_unlock(¤t
->perf_event_mutex
);
6604 * Precalculate sample_data sizes
6606 perf_event__header_size(event
);
6607 perf_event__id_header_size(event
);
6610 * Drop the reference on the group_event after placing the
6611 * new event on the sibling_list. This ensures destruction
6612 * of the group leader will find the pointer to itself in
6613 * perf_group_detach().
6615 fput_light(group_file
, fput_needed
);
6616 fd_install(event_fd
, event_file
);
6620 perf_unpin_context(ctx
);
6626 put_task_struct(task
);
6628 fput_light(group_file
, fput_needed
);
6630 put_unused_fd(event_fd
);
6635 * perf_event_create_kernel_counter
6637 * @attr: attributes of the counter to create
6638 * @cpu: cpu in which the counter is bound
6639 * @task: task to profile (NULL for percpu)
6642 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6643 struct task_struct
*task
,
6644 perf_overflow_handler_t overflow_handler
)
6646 struct perf_event_context
*ctx
;
6647 struct perf_event
*event
;
6651 * Get the target context (task or percpu):
6654 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
, overflow_handler
);
6655 if (IS_ERR(event
)) {
6656 err
= PTR_ERR(event
);
6660 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6667 WARN_ON_ONCE(ctx
->parent_ctx
);
6668 mutex_lock(&ctx
->mutex
);
6669 perf_install_in_context(ctx
, event
, cpu
);
6671 perf_unpin_context(ctx
);
6672 mutex_unlock(&ctx
->mutex
);
6679 return ERR_PTR(err
);
6681 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6683 static void sync_child_event(struct perf_event
*child_event
,
6684 struct task_struct
*child
)
6686 struct perf_event
*parent_event
= child_event
->parent
;
6689 if (child_event
->attr
.inherit_stat
)
6690 perf_event_read_event(child_event
, child
);
6692 child_val
= perf_event_count(child_event
);
6695 * Add back the child's count to the parent's count:
6697 atomic64_add(child_val
, &parent_event
->child_count
);
6698 atomic64_add(child_event
->total_time_enabled
,
6699 &parent_event
->child_total_time_enabled
);
6700 atomic64_add(child_event
->total_time_running
,
6701 &parent_event
->child_total_time_running
);
6704 * Remove this event from the parent's list
6706 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6707 mutex_lock(&parent_event
->child_mutex
);
6708 list_del_init(&child_event
->child_list
);
6709 mutex_unlock(&parent_event
->child_mutex
);
6712 * Release the parent event, if this was the last
6715 fput(parent_event
->filp
);
6719 __perf_event_exit_task(struct perf_event
*child_event
,
6720 struct perf_event_context
*child_ctx
,
6721 struct task_struct
*child
)
6723 struct perf_event
*parent_event
;
6725 perf_remove_from_context(child_event
);
6727 parent_event
= child_event
->parent
;
6729 * It can happen that parent exits first, and has events
6730 * that are still around due to the child reference. These
6731 * events need to be zapped - but otherwise linger.
6734 sync_child_event(child_event
, child
);
6735 free_event(child_event
);
6739 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6741 struct perf_event
*child_event
, *tmp
;
6742 struct perf_event_context
*child_ctx
;
6743 unsigned long flags
;
6745 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6746 perf_event_task(child
, NULL
, 0);
6750 local_irq_save(flags
);
6752 * We can't reschedule here because interrupts are disabled,
6753 * and either child is current or it is a task that can't be
6754 * scheduled, so we are now safe from rescheduling changing
6757 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6758 task_ctx_sched_out(child_ctx
, EVENT_ALL
);
6761 * Take the context lock here so that if find_get_context is
6762 * reading child->perf_event_ctxp, we wait until it has
6763 * incremented the context's refcount before we do put_ctx below.
6765 raw_spin_lock(&child_ctx
->lock
);
6766 child
->perf_event_ctxp
[ctxn
] = NULL
;
6768 * If this context is a clone; unclone it so it can't get
6769 * swapped to another process while we're removing all
6770 * the events from it.
6772 unclone_ctx(child_ctx
);
6773 update_context_time(child_ctx
);
6774 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6777 * Report the task dead after unscheduling the events so that we
6778 * won't get any samples after PERF_RECORD_EXIT. We can however still
6779 * get a few PERF_RECORD_READ events.
6781 perf_event_task(child
, child_ctx
, 0);
6784 * We can recurse on the same lock type through:
6786 * __perf_event_exit_task()
6787 * sync_child_event()
6788 * fput(parent_event->filp)
6790 * mutex_lock(&ctx->mutex)
6792 * But since its the parent context it won't be the same instance.
6794 mutex_lock(&child_ctx
->mutex
);
6797 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6799 __perf_event_exit_task(child_event
, child_ctx
, child
);
6801 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6803 __perf_event_exit_task(child_event
, child_ctx
, child
);
6806 * If the last event was a group event, it will have appended all
6807 * its siblings to the list, but we obtained 'tmp' before that which
6808 * will still point to the list head terminating the iteration.
6810 if (!list_empty(&child_ctx
->pinned_groups
) ||
6811 !list_empty(&child_ctx
->flexible_groups
))
6814 mutex_unlock(&child_ctx
->mutex
);
6820 * When a child task exits, feed back event values to parent events.
6822 void perf_event_exit_task(struct task_struct
*child
)
6824 struct perf_event
*event
, *tmp
;
6827 mutex_lock(&child
->perf_event_mutex
);
6828 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6830 list_del_init(&event
->owner_entry
);
6833 * Ensure the list deletion is visible before we clear
6834 * the owner, closes a race against perf_release() where
6835 * we need to serialize on the owner->perf_event_mutex.
6838 event
->owner
= NULL
;
6840 mutex_unlock(&child
->perf_event_mutex
);
6842 for_each_task_context_nr(ctxn
)
6843 perf_event_exit_task_context(child
, ctxn
);
6846 static void perf_free_event(struct perf_event
*event
,
6847 struct perf_event_context
*ctx
)
6849 struct perf_event
*parent
= event
->parent
;
6851 if (WARN_ON_ONCE(!parent
))
6854 mutex_lock(&parent
->child_mutex
);
6855 list_del_init(&event
->child_list
);
6856 mutex_unlock(&parent
->child_mutex
);
6860 perf_group_detach(event
);
6861 list_del_event(event
, ctx
);
6866 * free an unexposed, unused context as created by inheritance by
6867 * perf_event_init_task below, used by fork() in case of fail.
6869 void perf_event_free_task(struct task_struct
*task
)
6871 struct perf_event_context
*ctx
;
6872 struct perf_event
*event
, *tmp
;
6875 for_each_task_context_nr(ctxn
) {
6876 ctx
= task
->perf_event_ctxp
[ctxn
];
6880 mutex_lock(&ctx
->mutex
);
6882 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6884 perf_free_event(event
, ctx
);
6886 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6888 perf_free_event(event
, ctx
);
6890 if (!list_empty(&ctx
->pinned_groups
) ||
6891 !list_empty(&ctx
->flexible_groups
))
6894 mutex_unlock(&ctx
->mutex
);
6900 void perf_event_delayed_put(struct task_struct
*task
)
6904 for_each_task_context_nr(ctxn
)
6905 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6909 * inherit a event from parent task to child task:
6911 static struct perf_event
*
6912 inherit_event(struct perf_event
*parent_event
,
6913 struct task_struct
*parent
,
6914 struct perf_event_context
*parent_ctx
,
6915 struct task_struct
*child
,
6916 struct perf_event
*group_leader
,
6917 struct perf_event_context
*child_ctx
)
6919 struct perf_event
*child_event
;
6920 unsigned long flags
;
6923 * Instead of creating recursive hierarchies of events,
6924 * we link inherited events back to the original parent,
6925 * which has a filp for sure, which we use as the reference
6928 if (parent_event
->parent
)
6929 parent_event
= parent_event
->parent
;
6931 child_event
= perf_event_alloc(&parent_event
->attr
,
6934 group_leader
, parent_event
,
6936 if (IS_ERR(child_event
))
6941 * Make the child state follow the state of the parent event,
6942 * not its attr.disabled bit. We hold the parent's mutex,
6943 * so we won't race with perf_event_{en, dis}able_family.
6945 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6946 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6948 child_event
->state
= PERF_EVENT_STATE_OFF
;
6950 if (parent_event
->attr
.freq
) {
6951 u64 sample_period
= parent_event
->hw
.sample_period
;
6952 struct hw_perf_event
*hwc
= &child_event
->hw
;
6954 hwc
->sample_period
= sample_period
;
6955 hwc
->last_period
= sample_period
;
6957 local64_set(&hwc
->period_left
, sample_period
);
6960 child_event
->ctx
= child_ctx
;
6961 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6964 * Precalculate sample_data sizes
6966 perf_event__header_size(child_event
);
6967 perf_event__id_header_size(child_event
);
6970 * Link it up in the child's context:
6972 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6973 add_event_to_ctx(child_event
, child_ctx
);
6974 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6977 * Get a reference to the parent filp - we will fput it
6978 * when the child event exits. This is safe to do because
6979 * we are in the parent and we know that the filp still
6980 * exists and has a nonzero count:
6982 atomic_long_inc(&parent_event
->filp
->f_count
);
6985 * Link this into the parent event's child list
6987 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6988 mutex_lock(&parent_event
->child_mutex
);
6989 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
6990 mutex_unlock(&parent_event
->child_mutex
);
6995 static int inherit_group(struct perf_event
*parent_event
,
6996 struct task_struct
*parent
,
6997 struct perf_event_context
*parent_ctx
,
6998 struct task_struct
*child
,
6999 struct perf_event_context
*child_ctx
)
7001 struct perf_event
*leader
;
7002 struct perf_event
*sub
;
7003 struct perf_event
*child_ctr
;
7005 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
7006 child
, NULL
, child_ctx
);
7008 return PTR_ERR(leader
);
7009 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
7010 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
7011 child
, leader
, child_ctx
);
7012 if (IS_ERR(child_ctr
))
7013 return PTR_ERR(child_ctr
);
7019 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
7020 struct perf_event_context
*parent_ctx
,
7021 struct task_struct
*child
, int ctxn
,
7025 struct perf_event_context
*child_ctx
;
7027 if (!event
->attr
.inherit
) {
7032 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7035 * This is executed from the parent task context, so
7036 * inherit events that have been marked for cloning.
7037 * First allocate and initialize a context for the
7041 child_ctx
= alloc_perf_context(event
->pmu
, child
);
7045 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
7048 ret
= inherit_group(event
, parent
, parent_ctx
,
7058 * Initialize the perf_event context in task_struct
7060 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
7062 struct perf_event_context
*child_ctx
, *parent_ctx
;
7063 struct perf_event_context
*cloned_ctx
;
7064 struct perf_event
*event
;
7065 struct task_struct
*parent
= current
;
7066 int inherited_all
= 1;
7067 unsigned long flags
;
7070 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
7074 * If the parent's context is a clone, pin it so it won't get
7077 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
7080 * No need to check if parent_ctx != NULL here; since we saw
7081 * it non-NULL earlier, the only reason for it to become NULL
7082 * is if we exit, and since we're currently in the middle of
7083 * a fork we can't be exiting at the same time.
7087 * Lock the parent list. No need to lock the child - not PID
7088 * hashed yet and not running, so nobody can access it.
7090 mutex_lock(&parent_ctx
->mutex
);
7093 * We dont have to disable NMIs - we are only looking at
7094 * the list, not manipulating it:
7096 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
7097 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7098 child
, ctxn
, &inherited_all
);
7104 * We can't hold ctx->lock when iterating the ->flexible_group list due
7105 * to allocations, but we need to prevent rotation because
7106 * rotate_ctx() will change the list from interrupt context.
7108 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7109 parent_ctx
->rotate_disable
= 1;
7110 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7112 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
7113 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7114 child
, ctxn
, &inherited_all
);
7119 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7120 parent_ctx
->rotate_disable
= 0;
7122 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7124 if (child_ctx
&& inherited_all
) {
7126 * Mark the child context as a clone of the parent
7127 * context, or of whatever the parent is a clone of.
7129 * Note that if the parent is a clone, the holding of
7130 * parent_ctx->lock avoids it from being uncloned.
7132 cloned_ctx
= parent_ctx
->parent_ctx
;
7134 child_ctx
->parent_ctx
= cloned_ctx
;
7135 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
7137 child_ctx
->parent_ctx
= parent_ctx
;
7138 child_ctx
->parent_gen
= parent_ctx
->generation
;
7140 get_ctx(child_ctx
->parent_ctx
);
7143 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7144 mutex_unlock(&parent_ctx
->mutex
);
7146 perf_unpin_context(parent_ctx
);
7147 put_ctx(parent_ctx
);
7153 * Initialize the perf_event context in task_struct
7155 int perf_event_init_task(struct task_struct
*child
)
7159 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7160 mutex_init(&child
->perf_event_mutex
);
7161 INIT_LIST_HEAD(&child
->perf_event_list
);
7163 for_each_task_context_nr(ctxn
) {
7164 ret
= perf_event_init_context(child
, ctxn
);
7172 static void __init
perf_event_init_all_cpus(void)
7174 struct swevent_htable
*swhash
;
7177 for_each_possible_cpu(cpu
) {
7178 swhash
= &per_cpu(swevent_htable
, cpu
);
7179 mutex_init(&swhash
->hlist_mutex
);
7180 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7184 static void __cpuinit
perf_event_init_cpu(int cpu
)
7186 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7188 mutex_lock(&swhash
->hlist_mutex
);
7189 if (swhash
->hlist_refcount
> 0) {
7190 struct swevent_hlist
*hlist
;
7192 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7194 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7196 mutex_unlock(&swhash
->hlist_mutex
);
7199 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7200 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7202 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7204 WARN_ON(!irqs_disabled());
7206 list_del_init(&cpuctx
->rotation_list
);
7209 static void __perf_event_exit_context(void *__info
)
7211 struct perf_event_context
*ctx
= __info
;
7212 struct perf_event
*event
, *tmp
;
7214 perf_pmu_rotate_stop(ctx
->pmu
);
7216 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
7217 __perf_remove_from_context(event
);
7218 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
7219 __perf_remove_from_context(event
);
7222 static void perf_event_exit_cpu_context(int cpu
)
7224 struct perf_event_context
*ctx
;
7228 idx
= srcu_read_lock(&pmus_srcu
);
7229 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7230 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
7232 mutex_lock(&ctx
->mutex
);
7233 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
7234 mutex_unlock(&ctx
->mutex
);
7236 srcu_read_unlock(&pmus_srcu
, idx
);
7239 static void perf_event_exit_cpu(int cpu
)
7241 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7243 mutex_lock(&swhash
->hlist_mutex
);
7244 swevent_hlist_release(swhash
);
7245 mutex_unlock(&swhash
->hlist_mutex
);
7247 perf_event_exit_cpu_context(cpu
);
7250 static inline void perf_event_exit_cpu(int cpu
) { }
7254 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
7258 for_each_online_cpu(cpu
)
7259 perf_event_exit_cpu(cpu
);
7265 * Run the perf reboot notifier at the very last possible moment so that
7266 * the generic watchdog code runs as long as possible.
7268 static struct notifier_block perf_reboot_notifier
= {
7269 .notifier_call
= perf_reboot
,
7270 .priority
= INT_MIN
,
7273 static int __cpuinit
7274 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
7276 unsigned int cpu
= (long)hcpu
;
7278 switch (action
& ~CPU_TASKS_FROZEN
) {
7280 case CPU_UP_PREPARE
:
7281 case CPU_DOWN_FAILED
:
7282 perf_event_init_cpu(cpu
);
7285 case CPU_UP_CANCELED
:
7286 case CPU_DOWN_PREPARE
:
7287 perf_event_exit_cpu(cpu
);
7297 void __init
perf_event_init(void)
7303 perf_event_init_all_cpus();
7304 init_srcu_struct(&pmus_srcu
);
7305 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
7306 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
7307 perf_pmu_register(&perf_task_clock
, NULL
, -1);
7309 perf_cpu_notifier(perf_cpu_notify
);
7310 register_reboot_notifier(&perf_reboot_notifier
);
7312 ret
= init_hw_breakpoint();
7313 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
7316 static int __init
perf_event_sysfs_init(void)
7321 mutex_lock(&pmus_lock
);
7323 ret
= bus_register(&pmu_bus
);
7327 list_for_each_entry(pmu
, &pmus
, entry
) {
7328 if (!pmu
->name
|| pmu
->type
< 0)
7331 ret
= pmu_dev_alloc(pmu
);
7332 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
7334 pmu_bus_running
= 1;
7338 mutex_unlock(&pmus_lock
);
7342 device_initcall(perf_event_sysfs_init
);
7344 #ifdef CONFIG_CGROUP_PERF
7345 static struct cgroup_subsys_state
*perf_cgroup_create(
7346 struct cgroup_subsys
*ss
, struct cgroup
*cont
)
7348 struct perf_cgroup
*jc
;
7350 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
7352 return ERR_PTR(-ENOMEM
);
7354 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
7357 return ERR_PTR(-ENOMEM
);
7363 static void perf_cgroup_destroy(struct cgroup_subsys
*ss
,
7364 struct cgroup
*cont
)
7366 struct perf_cgroup
*jc
;
7367 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
7368 struct perf_cgroup
, css
);
7369 free_percpu(jc
->info
);
7373 static int __perf_cgroup_move(void *info
)
7375 struct task_struct
*task
= info
;
7376 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
7380 static void perf_cgroup_move(struct task_struct
*task
)
7382 task_function_call(task
, __perf_cgroup_move
, task
);
7385 static void perf_cgroup_attach(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
7386 struct cgroup
*old_cgrp
, struct task_struct
*task
,
7389 perf_cgroup_move(task
);
7391 struct task_struct
*c
;
7393 list_for_each_entry_rcu(c
, &task
->thread_group
, thread_group
) {
7394 perf_cgroup_move(c
);
7400 static void perf_cgroup_exit(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
7401 struct cgroup
*old_cgrp
, struct task_struct
*task
)
7404 * cgroup_exit() is called in the copy_process() failure path.
7405 * Ignore this case since the task hasn't ran yet, this avoids
7406 * trying to poke a half freed task state from generic code.
7408 if (!(task
->flags
& PF_EXITING
))
7411 perf_cgroup_move(task
);
7414 struct cgroup_subsys perf_subsys
= {
7415 .name
= "perf_event",
7416 .subsys_id
= perf_subsys_id
,
7417 .create
= perf_cgroup_create
,
7418 .destroy
= perf_cgroup_destroy
,
7419 .exit
= perf_cgroup_exit
,
7420 .attach
= perf_cgroup_attach
,
7422 #endif /* CONFIG_CGROUP_PERF */