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
)
944 struct perf_cpu_context
*cpuctx
;
946 * We can have double detach due to exit/hot-unplug + close.
948 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
951 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
953 if (is_cgroup_event(event
)) {
955 cpuctx
= __get_cpu_context(ctx
);
957 * if there are no more cgroup events
958 * then cler cgrp to avoid stale pointer
959 * in update_cgrp_time_from_cpuctx()
961 if (!ctx
->nr_cgroups
)
966 if (event
->attr
.inherit_stat
)
969 list_del_rcu(&event
->event_entry
);
971 if (event
->group_leader
== event
)
972 list_del_init(&event
->group_entry
);
974 update_group_times(event
);
977 * If event was in error state, then keep it
978 * that way, otherwise bogus counts will be
979 * returned on read(). The only way to get out
980 * of error state is by explicit re-enabling
983 if (event
->state
> PERF_EVENT_STATE_OFF
)
984 event
->state
= PERF_EVENT_STATE_OFF
;
987 static void perf_group_detach(struct perf_event
*event
)
989 struct perf_event
*sibling
, *tmp
;
990 struct list_head
*list
= NULL
;
993 * We can have double detach due to exit/hot-unplug + close.
995 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
998 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1001 * If this is a sibling, remove it from its group.
1003 if (event
->group_leader
!= event
) {
1004 list_del_init(&event
->group_entry
);
1005 event
->group_leader
->nr_siblings
--;
1009 if (!list_empty(&event
->group_entry
))
1010 list
= &event
->group_entry
;
1013 * If this was a group event with sibling events then
1014 * upgrade the siblings to singleton events by adding them
1015 * to whatever list we are on.
1017 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1019 list_move_tail(&sibling
->group_entry
, list
);
1020 sibling
->group_leader
= sibling
;
1022 /* Inherit group flags from the previous leader */
1023 sibling
->group_flags
= event
->group_flags
;
1027 perf_event__header_size(event
->group_leader
);
1029 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1030 perf_event__header_size(tmp
);
1034 event_filter_match(struct perf_event
*event
)
1036 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1037 && perf_cgroup_match(event
);
1041 event_sched_out(struct perf_event
*event
,
1042 struct perf_cpu_context
*cpuctx
,
1043 struct perf_event_context
*ctx
)
1045 u64 tstamp
= perf_event_time(event
);
1048 * An event which could not be activated because of
1049 * filter mismatch still needs to have its timings
1050 * maintained, otherwise bogus information is return
1051 * via read() for time_enabled, time_running:
1053 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1054 && !event_filter_match(event
)) {
1055 delta
= tstamp
- event
->tstamp_stopped
;
1056 event
->tstamp_running
+= delta
;
1057 event
->tstamp_stopped
= tstamp
;
1060 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1063 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1064 if (event
->pending_disable
) {
1065 event
->pending_disable
= 0;
1066 event
->state
= PERF_EVENT_STATE_OFF
;
1068 event
->tstamp_stopped
= tstamp
;
1069 event
->pmu
->del(event
, 0);
1072 if (!is_software_event(event
))
1073 cpuctx
->active_oncpu
--;
1075 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1076 cpuctx
->exclusive
= 0;
1080 group_sched_out(struct perf_event
*group_event
,
1081 struct perf_cpu_context
*cpuctx
,
1082 struct perf_event_context
*ctx
)
1084 struct perf_event
*event
;
1085 int state
= group_event
->state
;
1087 event_sched_out(group_event
, cpuctx
, ctx
);
1090 * Schedule out siblings (if any):
1092 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1093 event_sched_out(event
, cpuctx
, ctx
);
1095 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1096 cpuctx
->exclusive
= 0;
1100 * Cross CPU call to remove a performance event
1102 * We disable the event on the hardware level first. After that we
1103 * remove it from the context list.
1105 static int __perf_remove_from_context(void *info
)
1107 struct perf_event
*event
= info
;
1108 struct perf_event_context
*ctx
= event
->ctx
;
1109 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1111 raw_spin_lock(&ctx
->lock
);
1112 event_sched_out(event
, cpuctx
, ctx
);
1113 list_del_event(event
, ctx
);
1114 raw_spin_unlock(&ctx
->lock
);
1121 * Remove the event from a task's (or a CPU's) list of events.
1123 * CPU events are removed with a smp call. For task events we only
1124 * call when the task is on a CPU.
1126 * If event->ctx is a cloned context, callers must make sure that
1127 * every task struct that event->ctx->task could possibly point to
1128 * remains valid. This is OK when called from perf_release since
1129 * that only calls us on the top-level context, which can't be a clone.
1130 * When called from perf_event_exit_task, it's OK because the
1131 * context has been detached from its task.
1133 static void perf_remove_from_context(struct perf_event
*event
)
1135 struct perf_event_context
*ctx
= event
->ctx
;
1136 struct task_struct
*task
= ctx
->task
;
1138 lockdep_assert_held(&ctx
->mutex
);
1142 * Per cpu events are removed via an smp call and
1143 * the removal is always successful.
1145 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1150 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1153 raw_spin_lock_irq(&ctx
->lock
);
1155 * If we failed to find a running task, but find the context active now
1156 * that we've acquired the ctx->lock, retry.
1158 if (ctx
->is_active
) {
1159 raw_spin_unlock_irq(&ctx
->lock
);
1164 * Since the task isn't running, its safe to remove the event, us
1165 * holding the ctx->lock ensures the task won't get scheduled in.
1167 list_del_event(event
, ctx
);
1168 raw_spin_unlock_irq(&ctx
->lock
);
1172 * Cross CPU call to disable a performance event
1174 static int __perf_event_disable(void *info
)
1176 struct perf_event
*event
= info
;
1177 struct perf_event_context
*ctx
= event
->ctx
;
1178 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1181 * If this is a per-task event, need to check whether this
1182 * event's task is the current task on this cpu.
1184 * Can trigger due to concurrent perf_event_context_sched_out()
1185 * flipping contexts around.
1187 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1190 raw_spin_lock(&ctx
->lock
);
1193 * If the event is on, turn it off.
1194 * If it is in error state, leave it in error state.
1196 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1197 update_context_time(ctx
);
1198 update_cgrp_time_from_event(event
);
1199 update_group_times(event
);
1200 if (event
== event
->group_leader
)
1201 group_sched_out(event
, cpuctx
, ctx
);
1203 event_sched_out(event
, cpuctx
, ctx
);
1204 event
->state
= PERF_EVENT_STATE_OFF
;
1207 raw_spin_unlock(&ctx
->lock
);
1215 * If event->ctx is a cloned context, callers must make sure that
1216 * every task struct that event->ctx->task could possibly point to
1217 * remains valid. This condition is satisifed when called through
1218 * perf_event_for_each_child or perf_event_for_each because they
1219 * hold the top-level event's child_mutex, so any descendant that
1220 * goes to exit will block in sync_child_event.
1221 * When called from perf_pending_event it's OK because event->ctx
1222 * is the current context on this CPU and preemption is disabled,
1223 * hence we can't get into perf_event_task_sched_out for this context.
1225 void perf_event_disable(struct perf_event
*event
)
1227 struct perf_event_context
*ctx
= event
->ctx
;
1228 struct task_struct
*task
= ctx
->task
;
1232 * Disable the event on the cpu that it's on
1234 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1239 if (!task_function_call(task
, __perf_event_disable
, event
))
1242 raw_spin_lock_irq(&ctx
->lock
);
1244 * If the event is still active, we need to retry the cross-call.
1246 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1247 raw_spin_unlock_irq(&ctx
->lock
);
1249 * Reload the task pointer, it might have been changed by
1250 * a concurrent perf_event_context_sched_out().
1257 * Since we have the lock this context can't be scheduled
1258 * in, so we can change the state safely.
1260 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1261 update_group_times(event
);
1262 event
->state
= PERF_EVENT_STATE_OFF
;
1264 raw_spin_unlock_irq(&ctx
->lock
);
1267 static void perf_set_shadow_time(struct perf_event
*event
,
1268 struct perf_event_context
*ctx
,
1272 * use the correct time source for the time snapshot
1274 * We could get by without this by leveraging the
1275 * fact that to get to this function, the caller
1276 * has most likely already called update_context_time()
1277 * and update_cgrp_time_xx() and thus both timestamp
1278 * are identical (or very close). Given that tstamp is,
1279 * already adjusted for cgroup, we could say that:
1280 * tstamp - ctx->timestamp
1282 * tstamp - cgrp->timestamp.
1284 * Then, in perf_output_read(), the calculation would
1285 * work with no changes because:
1286 * - event is guaranteed scheduled in
1287 * - no scheduled out in between
1288 * - thus the timestamp would be the same
1290 * But this is a bit hairy.
1292 * So instead, we have an explicit cgroup call to remain
1293 * within the time time source all along. We believe it
1294 * is cleaner and simpler to understand.
1296 if (is_cgroup_event(event
))
1297 perf_cgroup_set_shadow_time(event
, tstamp
);
1299 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1302 #define MAX_INTERRUPTS (~0ULL)
1304 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1307 event_sched_in(struct perf_event
*event
,
1308 struct perf_cpu_context
*cpuctx
,
1309 struct perf_event_context
*ctx
)
1311 u64 tstamp
= perf_event_time(event
);
1313 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1316 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1317 event
->oncpu
= smp_processor_id();
1320 * Unthrottle events, since we scheduled we might have missed several
1321 * ticks already, also for a heavily scheduling task there is little
1322 * guarantee it'll get a tick in a timely manner.
1324 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1325 perf_log_throttle(event
, 1);
1326 event
->hw
.interrupts
= 0;
1330 * The new state must be visible before we turn it on in the hardware:
1334 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1335 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1340 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1342 perf_set_shadow_time(event
, ctx
, tstamp
);
1344 if (!is_software_event(event
))
1345 cpuctx
->active_oncpu
++;
1348 if (event
->attr
.exclusive
)
1349 cpuctx
->exclusive
= 1;
1355 group_sched_in(struct perf_event
*group_event
,
1356 struct perf_cpu_context
*cpuctx
,
1357 struct perf_event_context
*ctx
)
1359 struct perf_event
*event
, *partial_group
= NULL
;
1360 struct pmu
*pmu
= group_event
->pmu
;
1361 u64 now
= ctx
->time
;
1362 bool simulate
= false;
1364 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1367 pmu
->start_txn(pmu
);
1369 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1370 pmu
->cancel_txn(pmu
);
1375 * Schedule in siblings as one group (if any):
1377 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1378 if (event_sched_in(event
, cpuctx
, ctx
)) {
1379 partial_group
= event
;
1384 if (!pmu
->commit_txn(pmu
))
1389 * Groups can be scheduled in as one unit only, so undo any
1390 * partial group before returning:
1391 * The events up to the failed event are scheduled out normally,
1392 * tstamp_stopped will be updated.
1394 * The failed events and the remaining siblings need to have
1395 * their timings updated as if they had gone thru event_sched_in()
1396 * and event_sched_out(). This is required to get consistent timings
1397 * across the group. This also takes care of the case where the group
1398 * could never be scheduled by ensuring tstamp_stopped is set to mark
1399 * the time the event was actually stopped, such that time delta
1400 * calculation in update_event_times() is correct.
1402 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1403 if (event
== partial_group
)
1407 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1408 event
->tstamp_stopped
= now
;
1410 event_sched_out(event
, cpuctx
, ctx
);
1413 event_sched_out(group_event
, cpuctx
, ctx
);
1415 pmu
->cancel_txn(pmu
);
1421 * Work out whether we can put this event group on the CPU now.
1423 static int group_can_go_on(struct perf_event
*event
,
1424 struct perf_cpu_context
*cpuctx
,
1428 * Groups consisting entirely of software events can always go on.
1430 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1433 * If an exclusive group is already on, no other hardware
1436 if (cpuctx
->exclusive
)
1439 * If this group is exclusive and there are already
1440 * events on the CPU, it can't go on.
1442 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1445 * Otherwise, try to add it if all previous groups were able
1451 static void add_event_to_ctx(struct perf_event
*event
,
1452 struct perf_event_context
*ctx
)
1454 u64 tstamp
= perf_event_time(event
);
1456 list_add_event(event
, ctx
);
1457 perf_group_attach(event
);
1458 event
->tstamp_enabled
= tstamp
;
1459 event
->tstamp_running
= tstamp
;
1460 event
->tstamp_stopped
= tstamp
;
1463 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
1464 struct task_struct
*tsk
);
1467 * Cross CPU call to install and enable a performance event
1469 * Must be called with ctx->mutex held
1471 static int __perf_install_in_context(void *info
)
1473 struct perf_event
*event
= info
;
1474 struct perf_event_context
*ctx
= event
->ctx
;
1475 struct perf_event
*leader
= event
->group_leader
;
1476 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1480 * In case we're installing a new context to an already running task,
1481 * could also happen before perf_event_task_sched_in() on architectures
1482 * which do context switches with IRQs enabled.
1484 if (ctx
->task
&& !cpuctx
->task_ctx
)
1485 perf_event_context_sched_in(ctx
, ctx
->task
);
1487 raw_spin_lock(&ctx
->lock
);
1489 update_context_time(ctx
);
1491 * update cgrp time only if current cgrp
1492 * matches event->cgrp. Must be done before
1493 * calling add_event_to_ctx()
1495 update_cgrp_time_from_event(event
);
1497 add_event_to_ctx(event
, ctx
);
1499 if (!event_filter_match(event
))
1503 * Don't put the event on if it is disabled or if
1504 * it is in a group and the group isn't on.
1506 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
1507 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
1511 * An exclusive event can't go on if there are already active
1512 * hardware events, and no hardware event can go on if there
1513 * is already an exclusive event on.
1515 if (!group_can_go_on(event
, cpuctx
, 1))
1518 err
= event_sched_in(event
, cpuctx
, ctx
);
1522 * This event couldn't go on. If it is in a group
1523 * then we have to pull the whole group off.
1524 * If the event group is pinned then put it in error state.
1526 if (leader
!= event
)
1527 group_sched_out(leader
, cpuctx
, ctx
);
1528 if (leader
->attr
.pinned
) {
1529 update_group_times(leader
);
1530 leader
->state
= PERF_EVENT_STATE_ERROR
;
1535 raw_spin_unlock(&ctx
->lock
);
1541 * Attach a performance event to a context
1543 * First we add the event to the list with the hardware enable bit
1544 * in event->hw_config cleared.
1546 * If the event is attached to a task which is on a CPU we use a smp
1547 * call to enable it in the task context. The task might have been
1548 * scheduled away, but we check this in the smp call again.
1551 perf_install_in_context(struct perf_event_context
*ctx
,
1552 struct perf_event
*event
,
1555 struct task_struct
*task
= ctx
->task
;
1557 lockdep_assert_held(&ctx
->mutex
);
1563 * Per cpu events are installed via an smp call and
1564 * the install is always successful.
1566 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1571 if (!task_function_call(task
, __perf_install_in_context
, event
))
1574 raw_spin_lock_irq(&ctx
->lock
);
1576 * If we failed to find a running task, but find the context active now
1577 * that we've acquired the ctx->lock, retry.
1579 if (ctx
->is_active
) {
1580 raw_spin_unlock_irq(&ctx
->lock
);
1585 * Since the task isn't running, its safe to add the event, us holding
1586 * the ctx->lock ensures the task won't get scheduled in.
1588 add_event_to_ctx(event
, ctx
);
1589 raw_spin_unlock_irq(&ctx
->lock
);
1593 * Put a event into inactive state and update time fields.
1594 * Enabling the leader of a group effectively enables all
1595 * the group members that aren't explicitly disabled, so we
1596 * have to update their ->tstamp_enabled also.
1597 * Note: this works for group members as well as group leaders
1598 * since the non-leader members' sibling_lists will be empty.
1600 static void __perf_event_mark_enabled(struct perf_event
*event
,
1601 struct perf_event_context
*ctx
)
1603 struct perf_event
*sub
;
1604 u64 tstamp
= perf_event_time(event
);
1606 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1607 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1608 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1609 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1610 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1615 * Cross CPU call to enable a performance event
1617 static int __perf_event_enable(void *info
)
1619 struct perf_event
*event
= info
;
1620 struct perf_event_context
*ctx
= event
->ctx
;
1621 struct perf_event
*leader
= event
->group_leader
;
1622 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1625 if (WARN_ON_ONCE(!ctx
->is_active
))
1628 raw_spin_lock(&ctx
->lock
);
1629 update_context_time(ctx
);
1631 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1635 * set current task's cgroup time reference point
1637 perf_cgroup_set_timestamp(current
, ctx
);
1639 __perf_event_mark_enabled(event
, ctx
);
1641 if (!event_filter_match(event
)) {
1642 if (is_cgroup_event(event
))
1643 perf_cgroup_defer_enabled(event
);
1648 * If the event is in a group and isn't the group leader,
1649 * then don't put it on unless the group is on.
1651 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1654 if (!group_can_go_on(event
, cpuctx
, 1)) {
1657 if (event
== leader
)
1658 err
= group_sched_in(event
, cpuctx
, ctx
);
1660 err
= event_sched_in(event
, cpuctx
, ctx
);
1665 * If this event can't go on and it's part of a
1666 * group, then the whole group has to come off.
1668 if (leader
!= event
)
1669 group_sched_out(leader
, cpuctx
, ctx
);
1670 if (leader
->attr
.pinned
) {
1671 update_group_times(leader
);
1672 leader
->state
= PERF_EVENT_STATE_ERROR
;
1677 raw_spin_unlock(&ctx
->lock
);
1685 * If event->ctx is a cloned context, callers must make sure that
1686 * every task struct that event->ctx->task could possibly point to
1687 * remains valid. This condition is satisfied when called through
1688 * perf_event_for_each_child or perf_event_for_each as described
1689 * for perf_event_disable.
1691 void perf_event_enable(struct perf_event
*event
)
1693 struct perf_event_context
*ctx
= event
->ctx
;
1694 struct task_struct
*task
= ctx
->task
;
1698 * Enable the event on the cpu that it's on
1700 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
1704 raw_spin_lock_irq(&ctx
->lock
);
1705 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1709 * If the event is in error state, clear that first.
1710 * That way, if we see the event in error state below, we
1711 * know that it has gone back into error state, as distinct
1712 * from the task having been scheduled away before the
1713 * cross-call arrived.
1715 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1716 event
->state
= PERF_EVENT_STATE_OFF
;
1719 if (!ctx
->is_active
) {
1720 __perf_event_mark_enabled(event
, ctx
);
1724 raw_spin_unlock_irq(&ctx
->lock
);
1726 if (!task_function_call(task
, __perf_event_enable
, event
))
1729 raw_spin_lock_irq(&ctx
->lock
);
1732 * If the context is active and the event is still off,
1733 * we need to retry the cross-call.
1735 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
1737 * task could have been flipped by a concurrent
1738 * perf_event_context_sched_out()
1745 raw_spin_unlock_irq(&ctx
->lock
);
1748 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1751 * not supported on inherited events
1753 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1756 atomic_add(refresh
, &event
->event_limit
);
1757 perf_event_enable(event
);
1762 static void ctx_sched_out(struct perf_event_context
*ctx
,
1763 struct perf_cpu_context
*cpuctx
,
1764 enum event_type_t event_type
)
1766 struct perf_event
*event
;
1768 raw_spin_lock(&ctx
->lock
);
1769 perf_pmu_disable(ctx
->pmu
);
1771 if (likely(!ctx
->nr_events
))
1773 update_context_time(ctx
);
1774 update_cgrp_time_from_cpuctx(cpuctx
);
1776 if (!ctx
->nr_active
)
1779 if (event_type
& EVENT_PINNED
) {
1780 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1781 group_sched_out(event
, cpuctx
, ctx
);
1784 if (event_type
& EVENT_FLEXIBLE
) {
1785 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1786 group_sched_out(event
, cpuctx
, ctx
);
1789 perf_pmu_enable(ctx
->pmu
);
1790 raw_spin_unlock(&ctx
->lock
);
1794 * Test whether two contexts are equivalent, i.e. whether they
1795 * have both been cloned from the same version of the same context
1796 * and they both have the same number of enabled events.
1797 * If the number of enabled events is the same, then the set
1798 * of enabled events should be the same, because these are both
1799 * inherited contexts, therefore we can't access individual events
1800 * in them directly with an fd; we can only enable/disable all
1801 * events via prctl, or enable/disable all events in a family
1802 * via ioctl, which will have the same effect on both contexts.
1804 static int context_equiv(struct perf_event_context
*ctx1
,
1805 struct perf_event_context
*ctx2
)
1807 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1808 && ctx1
->parent_gen
== ctx2
->parent_gen
1809 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1812 static void __perf_event_sync_stat(struct perf_event
*event
,
1813 struct perf_event
*next_event
)
1817 if (!event
->attr
.inherit_stat
)
1821 * Update the event value, we cannot use perf_event_read()
1822 * because we're in the middle of a context switch and have IRQs
1823 * disabled, which upsets smp_call_function_single(), however
1824 * we know the event must be on the current CPU, therefore we
1825 * don't need to use it.
1827 switch (event
->state
) {
1828 case PERF_EVENT_STATE_ACTIVE
:
1829 event
->pmu
->read(event
);
1832 case PERF_EVENT_STATE_INACTIVE
:
1833 update_event_times(event
);
1841 * In order to keep per-task stats reliable we need to flip the event
1842 * values when we flip the contexts.
1844 value
= local64_read(&next_event
->count
);
1845 value
= local64_xchg(&event
->count
, value
);
1846 local64_set(&next_event
->count
, value
);
1848 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1849 swap(event
->total_time_running
, next_event
->total_time_running
);
1852 * Since we swizzled the values, update the user visible data too.
1854 perf_event_update_userpage(event
);
1855 perf_event_update_userpage(next_event
);
1858 #define list_next_entry(pos, member) \
1859 list_entry(pos->member.next, typeof(*pos), member)
1861 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1862 struct perf_event_context
*next_ctx
)
1864 struct perf_event
*event
, *next_event
;
1869 update_context_time(ctx
);
1871 event
= list_first_entry(&ctx
->event_list
,
1872 struct perf_event
, event_entry
);
1874 next_event
= list_first_entry(&next_ctx
->event_list
,
1875 struct perf_event
, event_entry
);
1877 while (&event
->event_entry
!= &ctx
->event_list
&&
1878 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1880 __perf_event_sync_stat(event
, next_event
);
1882 event
= list_next_entry(event
, event_entry
);
1883 next_event
= list_next_entry(next_event
, event_entry
);
1887 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
1888 struct task_struct
*next
)
1890 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
1891 struct perf_event_context
*next_ctx
;
1892 struct perf_event_context
*parent
;
1893 struct perf_cpu_context
*cpuctx
;
1899 cpuctx
= __get_cpu_context(ctx
);
1900 if (!cpuctx
->task_ctx
)
1904 parent
= rcu_dereference(ctx
->parent_ctx
);
1905 next_ctx
= next
->perf_event_ctxp
[ctxn
];
1906 if (parent
&& next_ctx
&&
1907 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1909 * Looks like the two contexts are clones, so we might be
1910 * able to optimize the context switch. We lock both
1911 * contexts and check that they are clones under the
1912 * lock (including re-checking that neither has been
1913 * uncloned in the meantime). It doesn't matter which
1914 * order we take the locks because no other cpu could
1915 * be trying to lock both of these tasks.
1917 raw_spin_lock(&ctx
->lock
);
1918 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1919 if (context_equiv(ctx
, next_ctx
)) {
1921 * XXX do we need a memory barrier of sorts
1922 * wrt to rcu_dereference() of perf_event_ctxp
1924 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
1925 next
->perf_event_ctxp
[ctxn
] = ctx
;
1927 next_ctx
->task
= task
;
1930 perf_event_sync_stat(ctx
, next_ctx
);
1932 raw_spin_unlock(&next_ctx
->lock
);
1933 raw_spin_unlock(&ctx
->lock
);
1938 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1939 cpuctx
->task_ctx
= NULL
;
1943 #define for_each_task_context_nr(ctxn) \
1944 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
1947 * Called from scheduler to remove the events of the current task,
1948 * with interrupts disabled.
1950 * We stop each event and update the event value in event->count.
1952 * This does not protect us against NMI, but disable()
1953 * sets the disabled bit in the control field of event _before_
1954 * accessing the event control register. If a NMI hits, then it will
1955 * not restart the event.
1957 void __perf_event_task_sched_out(struct task_struct
*task
,
1958 struct task_struct
*next
)
1962 for_each_task_context_nr(ctxn
)
1963 perf_event_context_sched_out(task
, ctxn
, next
);
1966 * if cgroup events exist on this CPU, then we need
1967 * to check if we have to switch out PMU state.
1968 * cgroup event are system-wide mode only
1970 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
1971 perf_cgroup_sched_out(task
);
1974 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1975 enum event_type_t event_type
)
1977 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1979 if (!cpuctx
->task_ctx
)
1982 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1985 ctx_sched_out(ctx
, cpuctx
, event_type
);
1986 cpuctx
->task_ctx
= NULL
;
1990 * Called with IRQs disabled
1992 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1993 enum event_type_t event_type
)
1995 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1999 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2000 struct perf_cpu_context
*cpuctx
)
2002 struct perf_event
*event
;
2004 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2005 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2007 if (!event_filter_match(event
))
2010 /* may need to reset tstamp_enabled */
2011 if (is_cgroup_event(event
))
2012 perf_cgroup_mark_enabled(event
, ctx
);
2014 if (group_can_go_on(event
, cpuctx
, 1))
2015 group_sched_in(event
, cpuctx
, ctx
);
2018 * If this pinned group hasn't been scheduled,
2019 * put it in error state.
2021 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2022 update_group_times(event
);
2023 event
->state
= PERF_EVENT_STATE_ERROR
;
2029 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2030 struct perf_cpu_context
*cpuctx
)
2032 struct perf_event
*event
;
2035 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2036 /* Ignore events in OFF or ERROR state */
2037 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2040 * Listen to the 'cpu' scheduling filter constraint
2043 if (!event_filter_match(event
))
2046 /* may need to reset tstamp_enabled */
2047 if (is_cgroup_event(event
))
2048 perf_cgroup_mark_enabled(event
, ctx
);
2050 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2051 if (group_sched_in(event
, cpuctx
, ctx
))
2058 ctx_sched_in(struct perf_event_context
*ctx
,
2059 struct perf_cpu_context
*cpuctx
,
2060 enum event_type_t event_type
,
2061 struct task_struct
*task
)
2065 raw_spin_lock(&ctx
->lock
);
2067 if (likely(!ctx
->nr_events
))
2071 ctx
->timestamp
= now
;
2072 perf_cgroup_set_timestamp(task
, ctx
);
2074 * First go through the list and put on any pinned groups
2075 * in order to give them the best chance of going on.
2077 if (event_type
& EVENT_PINNED
)
2078 ctx_pinned_sched_in(ctx
, cpuctx
);
2080 /* Then walk through the lower prio flexible groups */
2081 if (event_type
& EVENT_FLEXIBLE
)
2082 ctx_flexible_sched_in(ctx
, cpuctx
);
2085 raw_spin_unlock(&ctx
->lock
);
2088 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2089 enum event_type_t event_type
,
2090 struct task_struct
*task
)
2092 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2094 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2097 static void task_ctx_sched_in(struct perf_event_context
*ctx
,
2098 enum event_type_t event_type
)
2100 struct perf_cpu_context
*cpuctx
;
2102 cpuctx
= __get_cpu_context(ctx
);
2103 if (cpuctx
->task_ctx
== ctx
)
2106 ctx_sched_in(ctx
, cpuctx
, event_type
, NULL
);
2107 cpuctx
->task_ctx
= ctx
;
2110 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2111 struct task_struct
*task
)
2113 struct perf_cpu_context
*cpuctx
;
2115 cpuctx
= __get_cpu_context(ctx
);
2116 if (cpuctx
->task_ctx
== ctx
)
2119 perf_pmu_disable(ctx
->pmu
);
2121 * We want to keep the following priority order:
2122 * cpu pinned (that don't need to move), task pinned,
2123 * cpu flexible, task flexible.
2125 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2127 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2128 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2129 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2131 cpuctx
->task_ctx
= ctx
;
2134 * Since these rotations are per-cpu, we need to ensure the
2135 * cpu-context we got scheduled on is actually rotating.
2137 perf_pmu_rotate_start(ctx
->pmu
);
2138 perf_pmu_enable(ctx
->pmu
);
2142 * Called from scheduler to add the events of the current task
2143 * with interrupts disabled.
2145 * We restore the event value and then enable it.
2147 * This does not protect us against NMI, but enable()
2148 * sets the enabled bit in the control field of event _before_
2149 * accessing the event control register. If a NMI hits, then it will
2150 * keep the event running.
2152 void __perf_event_task_sched_in(struct task_struct
*task
)
2154 struct perf_event_context
*ctx
;
2157 for_each_task_context_nr(ctxn
) {
2158 ctx
= task
->perf_event_ctxp
[ctxn
];
2162 perf_event_context_sched_in(ctx
, task
);
2165 * if cgroup events exist on this CPU, then we need
2166 * to check if we have to switch in PMU state.
2167 * cgroup event are system-wide mode only
2169 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2170 perf_cgroup_sched_in(task
);
2173 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2175 u64 frequency
= event
->attr
.sample_freq
;
2176 u64 sec
= NSEC_PER_SEC
;
2177 u64 divisor
, dividend
;
2179 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2181 count_fls
= fls64(count
);
2182 nsec_fls
= fls64(nsec
);
2183 frequency_fls
= fls64(frequency
);
2187 * We got @count in @nsec, with a target of sample_freq HZ
2188 * the target period becomes:
2191 * period = -------------------
2192 * @nsec * sample_freq
2197 * Reduce accuracy by one bit such that @a and @b converge
2198 * to a similar magnitude.
2200 #define REDUCE_FLS(a, b) \
2202 if (a##_fls > b##_fls) { \
2212 * Reduce accuracy until either term fits in a u64, then proceed with
2213 * the other, so that finally we can do a u64/u64 division.
2215 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2216 REDUCE_FLS(nsec
, frequency
);
2217 REDUCE_FLS(sec
, count
);
2220 if (count_fls
+ sec_fls
> 64) {
2221 divisor
= nsec
* frequency
;
2223 while (count_fls
+ sec_fls
> 64) {
2224 REDUCE_FLS(count
, sec
);
2228 dividend
= count
* sec
;
2230 dividend
= count
* sec
;
2232 while (nsec_fls
+ frequency_fls
> 64) {
2233 REDUCE_FLS(nsec
, frequency
);
2237 divisor
= nsec
* frequency
;
2243 return div64_u64(dividend
, divisor
);
2246 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2248 struct hw_perf_event
*hwc
= &event
->hw
;
2249 s64 period
, sample_period
;
2252 period
= perf_calculate_period(event
, nsec
, count
);
2254 delta
= (s64
)(period
- hwc
->sample_period
);
2255 delta
= (delta
+ 7) / 8; /* low pass filter */
2257 sample_period
= hwc
->sample_period
+ delta
;
2262 hwc
->sample_period
= sample_period
;
2264 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2265 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2266 local64_set(&hwc
->period_left
, 0);
2267 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2271 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
, u64 period
)
2273 struct perf_event
*event
;
2274 struct hw_perf_event
*hwc
;
2275 u64 interrupts
, now
;
2278 raw_spin_lock(&ctx
->lock
);
2279 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2280 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2283 if (!event_filter_match(event
))
2288 interrupts
= hwc
->interrupts
;
2289 hwc
->interrupts
= 0;
2292 * unthrottle events on the tick
2294 if (interrupts
== MAX_INTERRUPTS
) {
2295 perf_log_throttle(event
, 1);
2296 event
->pmu
->start(event
, 0);
2299 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2302 event
->pmu
->read(event
);
2303 now
= local64_read(&event
->count
);
2304 delta
= now
- hwc
->freq_count_stamp
;
2305 hwc
->freq_count_stamp
= now
;
2308 perf_adjust_period(event
, period
, delta
);
2310 raw_spin_unlock(&ctx
->lock
);
2314 * Round-robin a context's events:
2316 static void rotate_ctx(struct perf_event_context
*ctx
)
2318 raw_spin_lock(&ctx
->lock
);
2321 * Rotate the first entry last of non-pinned groups. Rotation might be
2322 * disabled by the inheritance code.
2324 if (!ctx
->rotate_disable
)
2325 list_rotate_left(&ctx
->flexible_groups
);
2327 raw_spin_unlock(&ctx
->lock
);
2331 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2332 * because they're strictly cpu affine and rotate_start is called with IRQs
2333 * disabled, while rotate_context is called from IRQ context.
2335 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2337 u64 interval
= (u64
)cpuctx
->jiffies_interval
* TICK_NSEC
;
2338 struct perf_event_context
*ctx
= NULL
;
2339 int rotate
= 0, remove
= 1;
2341 if (cpuctx
->ctx
.nr_events
) {
2343 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2347 ctx
= cpuctx
->task_ctx
;
2348 if (ctx
&& ctx
->nr_events
) {
2350 if (ctx
->nr_events
!= ctx
->nr_active
)
2354 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2355 perf_ctx_adjust_freq(&cpuctx
->ctx
, interval
);
2357 perf_ctx_adjust_freq(ctx
, interval
);
2362 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2364 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
2366 rotate_ctx(&cpuctx
->ctx
);
2370 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, current
);
2372 task_ctx_sched_in(ctx
, EVENT_FLEXIBLE
);
2376 list_del_init(&cpuctx
->rotation_list
);
2378 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2381 void perf_event_task_tick(void)
2383 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2384 struct perf_cpu_context
*cpuctx
, *tmp
;
2386 WARN_ON(!irqs_disabled());
2388 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2389 if (cpuctx
->jiffies_interval
== 1 ||
2390 !(jiffies
% cpuctx
->jiffies_interval
))
2391 perf_rotate_context(cpuctx
);
2395 static int event_enable_on_exec(struct perf_event
*event
,
2396 struct perf_event_context
*ctx
)
2398 if (!event
->attr
.enable_on_exec
)
2401 event
->attr
.enable_on_exec
= 0;
2402 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2405 __perf_event_mark_enabled(event
, ctx
);
2411 * Enable all of a task's events that have been marked enable-on-exec.
2412 * This expects task == current.
2414 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2416 struct perf_event
*event
;
2417 unsigned long flags
;
2421 local_irq_save(flags
);
2422 if (!ctx
|| !ctx
->nr_events
)
2425 task_ctx_sched_out(ctx
, EVENT_ALL
);
2427 raw_spin_lock(&ctx
->lock
);
2429 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2430 ret
= event_enable_on_exec(event
, ctx
);
2435 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2436 ret
= event_enable_on_exec(event
, ctx
);
2442 * Unclone this context if we enabled any event.
2447 raw_spin_unlock(&ctx
->lock
);
2449 perf_event_context_sched_in(ctx
, ctx
->task
);
2451 local_irq_restore(flags
);
2455 * Cross CPU call to read the hardware event
2457 static void __perf_event_read(void *info
)
2459 struct perf_event
*event
= info
;
2460 struct perf_event_context
*ctx
= event
->ctx
;
2461 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2464 * If this is a task context, we need to check whether it is
2465 * the current task context of this cpu. If not it has been
2466 * scheduled out before the smp call arrived. In that case
2467 * event->count would have been updated to a recent sample
2468 * when the event was scheduled out.
2470 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2473 raw_spin_lock(&ctx
->lock
);
2474 if (ctx
->is_active
) {
2475 update_context_time(ctx
);
2476 update_cgrp_time_from_event(event
);
2478 update_event_times(event
);
2479 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2480 event
->pmu
->read(event
);
2481 raw_spin_unlock(&ctx
->lock
);
2484 static inline u64
perf_event_count(struct perf_event
*event
)
2486 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2489 static u64
perf_event_read(struct perf_event
*event
)
2492 * If event is enabled and currently active on a CPU, update the
2493 * value in the event structure:
2495 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2496 smp_call_function_single(event
->oncpu
,
2497 __perf_event_read
, event
, 1);
2498 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2499 struct perf_event_context
*ctx
= event
->ctx
;
2500 unsigned long flags
;
2502 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2504 * may read while context is not active
2505 * (e.g., thread is blocked), in that case
2506 * we cannot update context time
2508 if (ctx
->is_active
) {
2509 update_context_time(ctx
);
2510 update_cgrp_time_from_event(event
);
2512 update_event_times(event
);
2513 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2516 return perf_event_count(event
);
2523 struct callchain_cpus_entries
{
2524 struct rcu_head rcu_head
;
2525 struct perf_callchain_entry
*cpu_entries
[0];
2528 static DEFINE_PER_CPU(int, callchain_recursion
[PERF_NR_CONTEXTS
]);
2529 static atomic_t nr_callchain_events
;
2530 static DEFINE_MUTEX(callchain_mutex
);
2531 struct callchain_cpus_entries
*callchain_cpus_entries
;
2534 __weak
void perf_callchain_kernel(struct perf_callchain_entry
*entry
,
2535 struct pt_regs
*regs
)
2539 __weak
void perf_callchain_user(struct perf_callchain_entry
*entry
,
2540 struct pt_regs
*regs
)
2544 static void release_callchain_buffers_rcu(struct rcu_head
*head
)
2546 struct callchain_cpus_entries
*entries
;
2549 entries
= container_of(head
, struct callchain_cpus_entries
, rcu_head
);
2551 for_each_possible_cpu(cpu
)
2552 kfree(entries
->cpu_entries
[cpu
]);
2557 static void release_callchain_buffers(void)
2559 struct callchain_cpus_entries
*entries
;
2561 entries
= callchain_cpus_entries
;
2562 rcu_assign_pointer(callchain_cpus_entries
, NULL
);
2563 call_rcu(&entries
->rcu_head
, release_callchain_buffers_rcu
);
2566 static int alloc_callchain_buffers(void)
2570 struct callchain_cpus_entries
*entries
;
2573 * We can't use the percpu allocation API for data that can be
2574 * accessed from NMI. Use a temporary manual per cpu allocation
2575 * until that gets sorted out.
2577 size
= offsetof(struct callchain_cpus_entries
, cpu_entries
[nr_cpu_ids
]);
2579 entries
= kzalloc(size
, GFP_KERNEL
);
2583 size
= sizeof(struct perf_callchain_entry
) * PERF_NR_CONTEXTS
;
2585 for_each_possible_cpu(cpu
) {
2586 entries
->cpu_entries
[cpu
] = kmalloc_node(size
, GFP_KERNEL
,
2588 if (!entries
->cpu_entries
[cpu
])
2592 rcu_assign_pointer(callchain_cpus_entries
, entries
);
2597 for_each_possible_cpu(cpu
)
2598 kfree(entries
->cpu_entries
[cpu
]);
2604 static int get_callchain_buffers(void)
2609 mutex_lock(&callchain_mutex
);
2611 count
= atomic_inc_return(&nr_callchain_events
);
2612 if (WARN_ON_ONCE(count
< 1)) {
2618 /* If the allocation failed, give up */
2619 if (!callchain_cpus_entries
)
2624 err
= alloc_callchain_buffers();
2626 release_callchain_buffers();
2628 mutex_unlock(&callchain_mutex
);
2633 static void put_callchain_buffers(void)
2635 if (atomic_dec_and_mutex_lock(&nr_callchain_events
, &callchain_mutex
)) {
2636 release_callchain_buffers();
2637 mutex_unlock(&callchain_mutex
);
2641 static int get_recursion_context(int *recursion
)
2649 else if (in_softirq())
2654 if (recursion
[rctx
])
2663 static inline void put_recursion_context(int *recursion
, int rctx
)
2669 static struct perf_callchain_entry
*get_callchain_entry(int *rctx
)
2672 struct callchain_cpus_entries
*entries
;
2674 *rctx
= get_recursion_context(__get_cpu_var(callchain_recursion
));
2678 entries
= rcu_dereference(callchain_cpus_entries
);
2682 cpu
= smp_processor_id();
2684 return &entries
->cpu_entries
[cpu
][*rctx
];
2688 put_callchain_entry(int rctx
)
2690 put_recursion_context(__get_cpu_var(callchain_recursion
), rctx
);
2693 static struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2696 struct perf_callchain_entry
*entry
;
2699 entry
= get_callchain_entry(&rctx
);
2708 if (!user_mode(regs
)) {
2709 perf_callchain_store(entry
, PERF_CONTEXT_KERNEL
);
2710 perf_callchain_kernel(entry
, regs
);
2712 regs
= task_pt_regs(current
);
2718 perf_callchain_store(entry
, PERF_CONTEXT_USER
);
2719 perf_callchain_user(entry
, regs
);
2723 put_callchain_entry(rctx
);
2729 * Initialize the perf_event context in a task_struct:
2731 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2733 raw_spin_lock_init(&ctx
->lock
);
2734 mutex_init(&ctx
->mutex
);
2735 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2736 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2737 INIT_LIST_HEAD(&ctx
->event_list
);
2738 atomic_set(&ctx
->refcount
, 1);
2741 static struct perf_event_context
*
2742 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2744 struct perf_event_context
*ctx
;
2746 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2750 __perf_event_init_context(ctx
);
2753 get_task_struct(task
);
2760 static struct task_struct
*
2761 find_lively_task_by_vpid(pid_t vpid
)
2763 struct task_struct
*task
;
2770 task
= find_task_by_vpid(vpid
);
2772 get_task_struct(task
);
2776 return ERR_PTR(-ESRCH
);
2778 /* Reuse ptrace permission checks for now. */
2780 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2785 put_task_struct(task
);
2786 return ERR_PTR(err
);
2791 * Returns a matching context with refcount and pincount.
2793 static struct perf_event_context
*
2794 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2796 struct perf_event_context
*ctx
;
2797 struct perf_cpu_context
*cpuctx
;
2798 unsigned long flags
;
2802 /* Must be root to operate on a CPU event: */
2803 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2804 return ERR_PTR(-EACCES
);
2807 * We could be clever and allow to attach a event to an
2808 * offline CPU and activate it when the CPU comes up, but
2811 if (!cpu_online(cpu
))
2812 return ERR_PTR(-ENODEV
);
2814 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2823 ctxn
= pmu
->task_ctx_nr
;
2828 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2832 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2836 ctx
= alloc_perf_context(pmu
, task
);
2844 mutex_lock(&task
->perf_event_mutex
);
2846 * If it has already passed perf_event_exit_task().
2847 * we must see PF_EXITING, it takes this mutex too.
2849 if (task
->flags
& PF_EXITING
)
2851 else if (task
->perf_event_ctxp
[ctxn
])
2855 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2857 mutex_unlock(&task
->perf_event_mutex
);
2859 if (unlikely(err
)) {
2860 put_task_struct(task
);
2872 return ERR_PTR(err
);
2875 static void perf_event_free_filter(struct perf_event
*event
);
2877 static void free_event_rcu(struct rcu_head
*head
)
2879 struct perf_event
*event
;
2881 event
= container_of(head
, struct perf_event
, rcu_head
);
2883 put_pid_ns(event
->ns
);
2884 perf_event_free_filter(event
);
2888 static void perf_buffer_put(struct perf_buffer
*buffer
);
2890 static void free_event(struct perf_event
*event
)
2892 irq_work_sync(&event
->pending
);
2894 if (!event
->parent
) {
2895 if (event
->attach_state
& PERF_ATTACH_TASK
)
2896 jump_label_dec(&perf_sched_events
);
2897 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2898 atomic_dec(&nr_mmap_events
);
2899 if (event
->attr
.comm
)
2900 atomic_dec(&nr_comm_events
);
2901 if (event
->attr
.task
)
2902 atomic_dec(&nr_task_events
);
2903 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2904 put_callchain_buffers();
2905 if (is_cgroup_event(event
)) {
2906 atomic_dec(&per_cpu(perf_cgroup_events
, event
->cpu
));
2907 jump_label_dec(&perf_sched_events
);
2911 if (event
->buffer
) {
2912 perf_buffer_put(event
->buffer
);
2913 event
->buffer
= NULL
;
2916 if (is_cgroup_event(event
))
2917 perf_detach_cgroup(event
);
2920 event
->destroy(event
);
2923 put_ctx(event
->ctx
);
2925 call_rcu(&event
->rcu_head
, free_event_rcu
);
2928 int perf_event_release_kernel(struct perf_event
*event
)
2930 struct perf_event_context
*ctx
= event
->ctx
;
2933 * Remove from the PMU, can't get re-enabled since we got
2934 * here because the last ref went.
2936 perf_event_disable(event
);
2938 WARN_ON_ONCE(ctx
->parent_ctx
);
2940 * There are two ways this annotation is useful:
2942 * 1) there is a lock recursion from perf_event_exit_task
2943 * see the comment there.
2945 * 2) there is a lock-inversion with mmap_sem through
2946 * perf_event_read_group(), which takes faults while
2947 * holding ctx->mutex, however this is called after
2948 * the last filedesc died, so there is no possibility
2949 * to trigger the AB-BA case.
2951 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2952 raw_spin_lock_irq(&ctx
->lock
);
2953 perf_group_detach(event
);
2954 list_del_event(event
, ctx
);
2955 raw_spin_unlock_irq(&ctx
->lock
);
2956 mutex_unlock(&ctx
->mutex
);
2962 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2965 * Called when the last reference to the file is gone.
2967 static int perf_release(struct inode
*inode
, struct file
*file
)
2969 struct perf_event
*event
= file
->private_data
;
2970 struct task_struct
*owner
;
2972 file
->private_data
= NULL
;
2975 owner
= ACCESS_ONCE(event
->owner
);
2977 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2978 * !owner it means the list deletion is complete and we can indeed
2979 * free this event, otherwise we need to serialize on
2980 * owner->perf_event_mutex.
2982 smp_read_barrier_depends();
2985 * Since delayed_put_task_struct() also drops the last
2986 * task reference we can safely take a new reference
2987 * while holding the rcu_read_lock().
2989 get_task_struct(owner
);
2994 mutex_lock(&owner
->perf_event_mutex
);
2996 * We have to re-check the event->owner field, if it is cleared
2997 * we raced with perf_event_exit_task(), acquiring the mutex
2998 * ensured they're done, and we can proceed with freeing the
3002 list_del_init(&event
->owner_entry
);
3003 mutex_unlock(&owner
->perf_event_mutex
);
3004 put_task_struct(owner
);
3007 return perf_event_release_kernel(event
);
3010 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3012 struct perf_event
*child
;
3018 mutex_lock(&event
->child_mutex
);
3019 total
+= perf_event_read(event
);
3020 *enabled
+= event
->total_time_enabled
+
3021 atomic64_read(&event
->child_total_time_enabled
);
3022 *running
+= event
->total_time_running
+
3023 atomic64_read(&event
->child_total_time_running
);
3025 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3026 total
+= perf_event_read(child
);
3027 *enabled
+= child
->total_time_enabled
;
3028 *running
+= child
->total_time_running
;
3030 mutex_unlock(&event
->child_mutex
);
3034 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3036 static int perf_event_read_group(struct perf_event
*event
,
3037 u64 read_format
, char __user
*buf
)
3039 struct perf_event
*leader
= event
->group_leader
, *sub
;
3040 int n
= 0, size
= 0, ret
= -EFAULT
;
3041 struct perf_event_context
*ctx
= leader
->ctx
;
3043 u64 count
, enabled
, running
;
3045 mutex_lock(&ctx
->mutex
);
3046 count
= perf_event_read_value(leader
, &enabled
, &running
);
3048 values
[n
++] = 1 + leader
->nr_siblings
;
3049 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3050 values
[n
++] = enabled
;
3051 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3052 values
[n
++] = running
;
3053 values
[n
++] = count
;
3054 if (read_format
& PERF_FORMAT_ID
)
3055 values
[n
++] = primary_event_id(leader
);
3057 size
= n
* sizeof(u64
);
3059 if (copy_to_user(buf
, values
, size
))
3064 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3067 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3068 if (read_format
& PERF_FORMAT_ID
)
3069 values
[n
++] = primary_event_id(sub
);
3071 size
= n
* sizeof(u64
);
3073 if (copy_to_user(buf
+ ret
, values
, size
)) {
3081 mutex_unlock(&ctx
->mutex
);
3086 static int perf_event_read_one(struct perf_event
*event
,
3087 u64 read_format
, char __user
*buf
)
3089 u64 enabled
, running
;
3093 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3094 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3095 values
[n
++] = enabled
;
3096 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3097 values
[n
++] = running
;
3098 if (read_format
& PERF_FORMAT_ID
)
3099 values
[n
++] = primary_event_id(event
);
3101 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3104 return n
* sizeof(u64
);
3108 * Read the performance event - simple non blocking version for now
3111 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3113 u64 read_format
= event
->attr
.read_format
;
3117 * Return end-of-file for a read on a event that is in
3118 * error state (i.e. because it was pinned but it couldn't be
3119 * scheduled on to the CPU at some point).
3121 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3124 if (count
< event
->read_size
)
3127 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3128 if (read_format
& PERF_FORMAT_GROUP
)
3129 ret
= perf_event_read_group(event
, read_format
, buf
);
3131 ret
= perf_event_read_one(event
, read_format
, buf
);
3137 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3139 struct perf_event
*event
= file
->private_data
;
3141 return perf_read_hw(event
, buf
, count
);
3144 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3146 struct perf_event
*event
= file
->private_data
;
3147 struct perf_buffer
*buffer
;
3148 unsigned int events
= POLL_HUP
;
3151 buffer
= rcu_dereference(event
->buffer
);
3153 events
= atomic_xchg(&buffer
->poll
, 0);
3156 poll_wait(file
, &event
->waitq
, wait
);
3161 static void perf_event_reset(struct perf_event
*event
)
3163 (void)perf_event_read(event
);
3164 local64_set(&event
->count
, 0);
3165 perf_event_update_userpage(event
);
3169 * Holding the top-level event's child_mutex means that any
3170 * descendant process that has inherited this event will block
3171 * in sync_child_event if it goes to exit, thus satisfying the
3172 * task existence requirements of perf_event_enable/disable.
3174 static void perf_event_for_each_child(struct perf_event
*event
,
3175 void (*func
)(struct perf_event
*))
3177 struct perf_event
*child
;
3179 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3180 mutex_lock(&event
->child_mutex
);
3182 list_for_each_entry(child
, &event
->child_list
, child_list
)
3184 mutex_unlock(&event
->child_mutex
);
3187 static void perf_event_for_each(struct perf_event
*event
,
3188 void (*func
)(struct perf_event
*))
3190 struct perf_event_context
*ctx
= event
->ctx
;
3191 struct perf_event
*sibling
;
3193 WARN_ON_ONCE(ctx
->parent_ctx
);
3194 mutex_lock(&ctx
->mutex
);
3195 event
= event
->group_leader
;
3197 perf_event_for_each_child(event
, func
);
3199 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3200 perf_event_for_each_child(event
, func
);
3201 mutex_unlock(&ctx
->mutex
);
3204 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3206 struct perf_event_context
*ctx
= event
->ctx
;
3210 if (!is_sampling_event(event
))
3213 if (copy_from_user(&value
, arg
, sizeof(value
)))
3219 raw_spin_lock_irq(&ctx
->lock
);
3220 if (event
->attr
.freq
) {
3221 if (value
> sysctl_perf_event_sample_rate
) {
3226 event
->attr
.sample_freq
= value
;
3228 event
->attr
.sample_period
= value
;
3229 event
->hw
.sample_period
= value
;
3232 raw_spin_unlock_irq(&ctx
->lock
);
3237 static const struct file_operations perf_fops
;
3239 static struct perf_event
*perf_fget_light(int fd
, int *fput_needed
)
3243 file
= fget_light(fd
, fput_needed
);
3245 return ERR_PTR(-EBADF
);
3247 if (file
->f_op
!= &perf_fops
) {
3248 fput_light(file
, *fput_needed
);
3250 return ERR_PTR(-EBADF
);
3253 return file
->private_data
;
3256 static int perf_event_set_output(struct perf_event
*event
,
3257 struct perf_event
*output_event
);
3258 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3260 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3262 struct perf_event
*event
= file
->private_data
;
3263 void (*func
)(struct perf_event
*);
3267 case PERF_EVENT_IOC_ENABLE
:
3268 func
= perf_event_enable
;
3270 case PERF_EVENT_IOC_DISABLE
:
3271 func
= perf_event_disable
;
3273 case PERF_EVENT_IOC_RESET
:
3274 func
= perf_event_reset
;
3277 case PERF_EVENT_IOC_REFRESH
:
3278 return perf_event_refresh(event
, arg
);
3280 case PERF_EVENT_IOC_PERIOD
:
3281 return perf_event_period(event
, (u64 __user
*)arg
);
3283 case PERF_EVENT_IOC_SET_OUTPUT
:
3285 struct perf_event
*output_event
= NULL
;
3286 int fput_needed
= 0;
3290 output_event
= perf_fget_light(arg
, &fput_needed
);
3291 if (IS_ERR(output_event
))
3292 return PTR_ERR(output_event
);
3295 ret
= perf_event_set_output(event
, output_event
);
3297 fput_light(output_event
->filp
, fput_needed
);
3302 case PERF_EVENT_IOC_SET_FILTER
:
3303 return perf_event_set_filter(event
, (void __user
*)arg
);
3309 if (flags
& PERF_IOC_FLAG_GROUP
)
3310 perf_event_for_each(event
, func
);
3312 perf_event_for_each_child(event
, func
);
3317 int perf_event_task_enable(void)
3319 struct perf_event
*event
;
3321 mutex_lock(¤t
->perf_event_mutex
);
3322 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3323 perf_event_for_each_child(event
, perf_event_enable
);
3324 mutex_unlock(¤t
->perf_event_mutex
);
3329 int perf_event_task_disable(void)
3331 struct perf_event
*event
;
3333 mutex_lock(¤t
->perf_event_mutex
);
3334 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3335 perf_event_for_each_child(event
, perf_event_disable
);
3336 mutex_unlock(¤t
->perf_event_mutex
);
3341 #ifndef PERF_EVENT_INDEX_OFFSET
3342 # define PERF_EVENT_INDEX_OFFSET 0
3345 static int perf_event_index(struct perf_event
*event
)
3347 if (event
->hw
.state
& PERF_HES_STOPPED
)
3350 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3353 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
3357 * Callers need to ensure there can be no nesting of this function, otherwise
3358 * the seqlock logic goes bad. We can not serialize this because the arch
3359 * code calls this from NMI context.
3361 void perf_event_update_userpage(struct perf_event
*event
)
3363 struct perf_event_mmap_page
*userpg
;
3364 struct perf_buffer
*buffer
;
3367 buffer
= rcu_dereference(event
->buffer
);
3371 userpg
= buffer
->user_page
;
3374 * Disable preemption so as to not let the corresponding user-space
3375 * spin too long if we get preempted.
3380 userpg
->index
= perf_event_index(event
);
3381 userpg
->offset
= perf_event_count(event
);
3382 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3383 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3385 userpg
->time_enabled
= event
->total_time_enabled
+
3386 atomic64_read(&event
->child_total_time_enabled
);
3388 userpg
->time_running
= event
->total_time_running
+
3389 atomic64_read(&event
->child_total_time_running
);
3398 static unsigned long perf_data_size(struct perf_buffer
*buffer
);
3401 perf_buffer_init(struct perf_buffer
*buffer
, long watermark
, int flags
)
3403 long max_size
= perf_data_size(buffer
);
3406 buffer
->watermark
= min(max_size
, watermark
);
3408 if (!buffer
->watermark
)
3409 buffer
->watermark
= max_size
/ 2;
3411 if (flags
& PERF_BUFFER_WRITABLE
)
3412 buffer
->writable
= 1;
3414 atomic_set(&buffer
->refcount
, 1);
3417 #ifndef CONFIG_PERF_USE_VMALLOC
3420 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
3423 static struct page
*
3424 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
3426 if (pgoff
> buffer
->nr_pages
)
3430 return virt_to_page(buffer
->user_page
);
3432 return virt_to_page(buffer
->data_pages
[pgoff
- 1]);
3435 static void *perf_mmap_alloc_page(int cpu
)
3440 node
= (cpu
== -1) ? cpu
: cpu_to_node(cpu
);
3441 page
= alloc_pages_node(node
, GFP_KERNEL
| __GFP_ZERO
, 0);
3445 return page_address(page
);
3448 static struct perf_buffer
*
3449 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
3451 struct perf_buffer
*buffer
;
3455 size
= sizeof(struct perf_buffer
);
3456 size
+= nr_pages
* sizeof(void *);
3458 buffer
= kzalloc(size
, GFP_KERNEL
);
3462 buffer
->user_page
= perf_mmap_alloc_page(cpu
);
3463 if (!buffer
->user_page
)
3464 goto fail_user_page
;
3466 for (i
= 0; i
< nr_pages
; i
++) {
3467 buffer
->data_pages
[i
] = perf_mmap_alloc_page(cpu
);
3468 if (!buffer
->data_pages
[i
])
3469 goto fail_data_pages
;
3472 buffer
->nr_pages
= nr_pages
;
3474 perf_buffer_init(buffer
, watermark
, flags
);
3479 for (i
--; i
>= 0; i
--)
3480 free_page((unsigned long)buffer
->data_pages
[i
]);
3482 free_page((unsigned long)buffer
->user_page
);
3491 static void perf_mmap_free_page(unsigned long addr
)
3493 struct page
*page
= virt_to_page((void *)addr
);
3495 page
->mapping
= NULL
;
3499 static void perf_buffer_free(struct perf_buffer
*buffer
)
3503 perf_mmap_free_page((unsigned long)buffer
->user_page
);
3504 for (i
= 0; i
< buffer
->nr_pages
; i
++)
3505 perf_mmap_free_page((unsigned long)buffer
->data_pages
[i
]);
3509 static inline int page_order(struct perf_buffer
*buffer
)
3517 * Back perf_mmap() with vmalloc memory.
3519 * Required for architectures that have d-cache aliasing issues.
3522 static inline int page_order(struct perf_buffer
*buffer
)
3524 return buffer
->page_order
;
3527 static struct page
*
3528 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
3530 if (pgoff
> (1UL << page_order(buffer
)))
3533 return vmalloc_to_page((void *)buffer
->user_page
+ pgoff
* PAGE_SIZE
);
3536 static void perf_mmap_unmark_page(void *addr
)
3538 struct page
*page
= vmalloc_to_page(addr
);
3540 page
->mapping
= NULL
;
3543 static void perf_buffer_free_work(struct work_struct
*work
)
3545 struct perf_buffer
*buffer
;
3549 buffer
= container_of(work
, struct perf_buffer
, work
);
3550 nr
= 1 << page_order(buffer
);
3552 base
= buffer
->user_page
;
3553 for (i
= 0; i
< nr
+ 1; i
++)
3554 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
3560 static void perf_buffer_free(struct perf_buffer
*buffer
)
3562 schedule_work(&buffer
->work
);
3565 static struct perf_buffer
*
3566 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
3568 struct perf_buffer
*buffer
;
3572 size
= sizeof(struct perf_buffer
);
3573 size
+= sizeof(void *);
3575 buffer
= kzalloc(size
, GFP_KERNEL
);
3579 INIT_WORK(&buffer
->work
, perf_buffer_free_work
);
3581 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
3585 buffer
->user_page
= all_buf
;
3586 buffer
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
3587 buffer
->page_order
= ilog2(nr_pages
);
3588 buffer
->nr_pages
= 1;
3590 perf_buffer_init(buffer
, watermark
, flags
);
3603 static unsigned long perf_data_size(struct perf_buffer
*buffer
)
3605 return buffer
->nr_pages
<< (PAGE_SHIFT
+ page_order(buffer
));
3608 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3610 struct perf_event
*event
= vma
->vm_file
->private_data
;
3611 struct perf_buffer
*buffer
;
3612 int ret
= VM_FAULT_SIGBUS
;
3614 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3615 if (vmf
->pgoff
== 0)
3621 buffer
= rcu_dereference(event
->buffer
);
3625 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3628 vmf
->page
= perf_mmap_to_page(buffer
, vmf
->pgoff
);
3632 get_page(vmf
->page
);
3633 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3634 vmf
->page
->index
= vmf
->pgoff
;
3643 static void perf_buffer_free_rcu(struct rcu_head
*rcu_head
)
3645 struct perf_buffer
*buffer
;
3647 buffer
= container_of(rcu_head
, struct perf_buffer
, rcu_head
);
3648 perf_buffer_free(buffer
);
3651 static struct perf_buffer
*perf_buffer_get(struct perf_event
*event
)
3653 struct perf_buffer
*buffer
;
3656 buffer
= rcu_dereference(event
->buffer
);
3658 if (!atomic_inc_not_zero(&buffer
->refcount
))
3666 static void perf_buffer_put(struct perf_buffer
*buffer
)
3668 if (!atomic_dec_and_test(&buffer
->refcount
))
3671 call_rcu(&buffer
->rcu_head
, perf_buffer_free_rcu
);
3674 static void perf_mmap_open(struct vm_area_struct
*vma
)
3676 struct perf_event
*event
= vma
->vm_file
->private_data
;
3678 atomic_inc(&event
->mmap_count
);
3681 static void perf_mmap_close(struct vm_area_struct
*vma
)
3683 struct perf_event
*event
= vma
->vm_file
->private_data
;
3685 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3686 unsigned long size
= perf_data_size(event
->buffer
);
3687 struct user_struct
*user
= event
->mmap_user
;
3688 struct perf_buffer
*buffer
= event
->buffer
;
3690 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3691 vma
->vm_mm
->locked_vm
-= event
->mmap_locked
;
3692 rcu_assign_pointer(event
->buffer
, NULL
);
3693 mutex_unlock(&event
->mmap_mutex
);
3695 perf_buffer_put(buffer
);
3700 static const struct vm_operations_struct perf_mmap_vmops
= {
3701 .open
= perf_mmap_open
,
3702 .close
= perf_mmap_close
,
3703 .fault
= perf_mmap_fault
,
3704 .page_mkwrite
= perf_mmap_fault
,
3707 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3709 struct perf_event
*event
= file
->private_data
;
3710 unsigned long user_locked
, user_lock_limit
;
3711 struct user_struct
*user
= current_user();
3712 unsigned long locked
, lock_limit
;
3713 struct perf_buffer
*buffer
;
3714 unsigned long vma_size
;
3715 unsigned long nr_pages
;
3716 long user_extra
, extra
;
3717 int ret
= 0, flags
= 0;
3720 * Don't allow mmap() of inherited per-task counters. This would
3721 * create a performance issue due to all children writing to the
3724 if (event
->cpu
== -1 && event
->attr
.inherit
)
3727 if (!(vma
->vm_flags
& VM_SHARED
))
3730 vma_size
= vma
->vm_end
- vma
->vm_start
;
3731 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3734 * If we have buffer pages ensure they're a power-of-two number, so we
3735 * can do bitmasks instead of modulo.
3737 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3740 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3743 if (vma
->vm_pgoff
!= 0)
3746 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3747 mutex_lock(&event
->mmap_mutex
);
3748 if (event
->buffer
) {
3749 if (event
->buffer
->nr_pages
== nr_pages
)
3750 atomic_inc(&event
->buffer
->refcount
);
3756 user_extra
= nr_pages
+ 1;
3757 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3760 * Increase the limit linearly with more CPUs:
3762 user_lock_limit
*= num_online_cpus();
3764 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3767 if (user_locked
> user_lock_limit
)
3768 extra
= user_locked
- user_lock_limit
;
3770 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3771 lock_limit
>>= PAGE_SHIFT
;
3772 locked
= vma
->vm_mm
->locked_vm
+ extra
;
3774 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3775 !capable(CAP_IPC_LOCK
)) {
3780 WARN_ON(event
->buffer
);
3782 if (vma
->vm_flags
& VM_WRITE
)
3783 flags
|= PERF_BUFFER_WRITABLE
;
3785 buffer
= perf_buffer_alloc(nr_pages
, event
->attr
.wakeup_watermark
,
3791 rcu_assign_pointer(event
->buffer
, buffer
);
3793 atomic_long_add(user_extra
, &user
->locked_vm
);
3794 event
->mmap_locked
= extra
;
3795 event
->mmap_user
= get_current_user();
3796 vma
->vm_mm
->locked_vm
+= event
->mmap_locked
;
3800 atomic_inc(&event
->mmap_count
);
3801 mutex_unlock(&event
->mmap_mutex
);
3803 vma
->vm_flags
|= VM_RESERVED
;
3804 vma
->vm_ops
= &perf_mmap_vmops
;
3809 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3811 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3812 struct perf_event
*event
= filp
->private_data
;
3815 mutex_lock(&inode
->i_mutex
);
3816 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3817 mutex_unlock(&inode
->i_mutex
);
3825 static const struct file_operations perf_fops
= {
3826 .llseek
= no_llseek
,
3827 .release
= perf_release
,
3830 .unlocked_ioctl
= perf_ioctl
,
3831 .compat_ioctl
= perf_ioctl
,
3833 .fasync
= perf_fasync
,
3839 * If there's data, ensure we set the poll() state and publish everything
3840 * to user-space before waking everybody up.
3843 void perf_event_wakeup(struct perf_event
*event
)
3845 wake_up_all(&event
->waitq
);
3847 if (event
->pending_kill
) {
3848 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3849 event
->pending_kill
= 0;
3853 static void perf_pending_event(struct irq_work
*entry
)
3855 struct perf_event
*event
= container_of(entry
,
3856 struct perf_event
, pending
);
3858 if (event
->pending_disable
) {
3859 event
->pending_disable
= 0;
3860 __perf_event_disable(event
);
3863 if (event
->pending_wakeup
) {
3864 event
->pending_wakeup
= 0;
3865 perf_event_wakeup(event
);
3870 * We assume there is only KVM supporting the callbacks.
3871 * Later on, we might change it to a list if there is
3872 * another virtualization implementation supporting the callbacks.
3874 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3876 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3878 perf_guest_cbs
= cbs
;
3881 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3883 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3885 perf_guest_cbs
= NULL
;
3888 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3893 static bool perf_output_space(struct perf_buffer
*buffer
, unsigned long tail
,
3894 unsigned long offset
, unsigned long head
)
3898 if (!buffer
->writable
)
3901 mask
= perf_data_size(buffer
) - 1;
3903 offset
= (offset
- tail
) & mask
;
3904 head
= (head
- tail
) & mask
;
3906 if ((int)(head
- offset
) < 0)
3912 static void perf_output_wakeup(struct perf_output_handle
*handle
)
3914 atomic_set(&handle
->buffer
->poll
, POLL_IN
);
3917 handle
->event
->pending_wakeup
= 1;
3918 irq_work_queue(&handle
->event
->pending
);
3920 perf_event_wakeup(handle
->event
);
3924 * We need to ensure a later event_id doesn't publish a head when a former
3925 * event isn't done writing. However since we need to deal with NMIs we
3926 * cannot fully serialize things.
3928 * We only publish the head (and generate a wakeup) when the outer-most
3931 static void perf_output_get_handle(struct perf_output_handle
*handle
)
3933 struct perf_buffer
*buffer
= handle
->buffer
;
3936 local_inc(&buffer
->nest
);
3937 handle
->wakeup
= local_read(&buffer
->wakeup
);
3940 static void perf_output_put_handle(struct perf_output_handle
*handle
)
3942 struct perf_buffer
*buffer
= handle
->buffer
;
3946 head
= local_read(&buffer
->head
);
3949 * IRQ/NMI can happen here, which means we can miss a head update.
3952 if (!local_dec_and_test(&buffer
->nest
))
3956 * Publish the known good head. Rely on the full barrier implied
3957 * by atomic_dec_and_test() order the buffer->head read and this
3960 buffer
->user_page
->data_head
= head
;
3963 * Now check if we missed an update, rely on the (compiler)
3964 * barrier in atomic_dec_and_test() to re-read buffer->head.
3966 if (unlikely(head
!= local_read(&buffer
->head
))) {
3967 local_inc(&buffer
->nest
);
3971 if (handle
->wakeup
!= local_read(&buffer
->wakeup
))
3972 perf_output_wakeup(handle
);
3978 __always_inline
void perf_output_copy(struct perf_output_handle
*handle
,
3979 const void *buf
, unsigned int len
)
3982 unsigned long size
= min_t(unsigned long, handle
->size
, len
);
3984 memcpy(handle
->addr
, buf
, size
);
3987 handle
->addr
+= size
;
3989 handle
->size
-= size
;
3990 if (!handle
->size
) {
3991 struct perf_buffer
*buffer
= handle
->buffer
;
3994 handle
->page
&= buffer
->nr_pages
- 1;
3995 handle
->addr
= buffer
->data_pages
[handle
->page
];
3996 handle
->size
= PAGE_SIZE
<< page_order(buffer
);
4001 static void __perf_event_header__init_id(struct perf_event_header
*header
,
4002 struct perf_sample_data
*data
,
4003 struct perf_event
*event
)
4005 u64 sample_type
= event
->attr
.sample_type
;
4007 data
->type
= sample_type
;
4008 header
->size
+= event
->id_header_size
;
4010 if (sample_type
& PERF_SAMPLE_TID
) {
4011 /* namespace issues */
4012 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
4013 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
4016 if (sample_type
& PERF_SAMPLE_TIME
)
4017 data
->time
= perf_clock();
4019 if (sample_type
& PERF_SAMPLE_ID
)
4020 data
->id
= primary_event_id(event
);
4022 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4023 data
->stream_id
= event
->id
;
4025 if (sample_type
& PERF_SAMPLE_CPU
) {
4026 data
->cpu_entry
.cpu
= raw_smp_processor_id();
4027 data
->cpu_entry
.reserved
= 0;
4031 static void perf_event_header__init_id(struct perf_event_header
*header
,
4032 struct perf_sample_data
*data
,
4033 struct perf_event
*event
)
4035 if (event
->attr
.sample_id_all
)
4036 __perf_event_header__init_id(header
, data
, event
);
4039 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
4040 struct perf_sample_data
*data
)
4042 u64 sample_type
= data
->type
;
4044 if (sample_type
& PERF_SAMPLE_TID
)
4045 perf_output_put(handle
, data
->tid_entry
);
4047 if (sample_type
& PERF_SAMPLE_TIME
)
4048 perf_output_put(handle
, data
->time
);
4050 if (sample_type
& PERF_SAMPLE_ID
)
4051 perf_output_put(handle
, data
->id
);
4053 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4054 perf_output_put(handle
, data
->stream_id
);
4056 if (sample_type
& PERF_SAMPLE_CPU
)
4057 perf_output_put(handle
, data
->cpu_entry
);
4060 static void perf_event__output_id_sample(struct perf_event
*event
,
4061 struct perf_output_handle
*handle
,
4062 struct perf_sample_data
*sample
)
4064 if (event
->attr
.sample_id_all
)
4065 __perf_event__output_id_sample(handle
, sample
);
4068 int perf_output_begin(struct perf_output_handle
*handle
,
4069 struct perf_event
*event
, unsigned int size
,
4070 int nmi
, int sample
)
4072 struct perf_buffer
*buffer
;
4073 unsigned long tail
, offset
, head
;
4075 struct perf_sample_data sample_data
;
4077 struct perf_event_header header
;
4084 * For inherited events we send all the output towards the parent.
4087 event
= event
->parent
;
4089 buffer
= rcu_dereference(event
->buffer
);
4093 handle
->buffer
= buffer
;
4094 handle
->event
= event
;
4096 handle
->sample
= sample
;
4098 if (!buffer
->nr_pages
)
4101 have_lost
= local_read(&buffer
->lost
);
4103 lost_event
.header
.size
= sizeof(lost_event
);
4104 perf_event_header__init_id(&lost_event
.header
, &sample_data
,
4106 size
+= lost_event
.header
.size
;
4109 perf_output_get_handle(handle
);
4113 * Userspace could choose to issue a mb() before updating the
4114 * tail pointer. So that all reads will be completed before the
4117 tail
= ACCESS_ONCE(buffer
->user_page
->data_tail
);
4119 offset
= head
= local_read(&buffer
->head
);
4121 if (unlikely(!perf_output_space(buffer
, tail
, offset
, head
)))
4123 } while (local_cmpxchg(&buffer
->head
, offset
, head
) != offset
);
4125 if (head
- local_read(&buffer
->wakeup
) > buffer
->watermark
)
4126 local_add(buffer
->watermark
, &buffer
->wakeup
);
4128 handle
->page
= offset
>> (PAGE_SHIFT
+ page_order(buffer
));
4129 handle
->page
&= buffer
->nr_pages
- 1;
4130 handle
->size
= offset
& ((PAGE_SIZE
<< page_order(buffer
)) - 1);
4131 handle
->addr
= buffer
->data_pages
[handle
->page
];
4132 handle
->addr
+= handle
->size
;
4133 handle
->size
= (PAGE_SIZE
<< page_order(buffer
)) - handle
->size
;
4136 lost_event
.header
.type
= PERF_RECORD_LOST
;
4137 lost_event
.header
.misc
= 0;
4138 lost_event
.id
= event
->id
;
4139 lost_event
.lost
= local_xchg(&buffer
->lost
, 0);
4141 perf_output_put(handle
, lost_event
);
4142 perf_event__output_id_sample(event
, handle
, &sample_data
);
4148 local_inc(&buffer
->lost
);
4149 perf_output_put_handle(handle
);
4156 void perf_output_end(struct perf_output_handle
*handle
)
4158 struct perf_event
*event
= handle
->event
;
4159 struct perf_buffer
*buffer
= handle
->buffer
;
4161 int wakeup_events
= event
->attr
.wakeup_events
;
4163 if (handle
->sample
&& wakeup_events
) {
4164 int events
= local_inc_return(&buffer
->events
);
4165 if (events
>= wakeup_events
) {
4166 local_sub(wakeup_events
, &buffer
->events
);
4167 local_inc(&buffer
->wakeup
);
4171 perf_output_put_handle(handle
);
4175 static void perf_output_read_one(struct perf_output_handle
*handle
,
4176 struct perf_event
*event
,
4177 u64 enabled
, u64 running
)
4179 u64 read_format
= event
->attr
.read_format
;
4183 values
[n
++] = perf_event_count(event
);
4184 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4185 values
[n
++] = enabled
+
4186 atomic64_read(&event
->child_total_time_enabled
);
4188 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4189 values
[n
++] = running
+
4190 atomic64_read(&event
->child_total_time_running
);
4192 if (read_format
& PERF_FORMAT_ID
)
4193 values
[n
++] = primary_event_id(event
);
4195 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4199 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
4201 static void perf_output_read_group(struct perf_output_handle
*handle
,
4202 struct perf_event
*event
,
4203 u64 enabled
, u64 running
)
4205 struct perf_event
*leader
= event
->group_leader
, *sub
;
4206 u64 read_format
= event
->attr
.read_format
;
4210 values
[n
++] = 1 + leader
->nr_siblings
;
4212 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4213 values
[n
++] = enabled
;
4215 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4216 values
[n
++] = running
;
4218 if (leader
!= event
)
4219 leader
->pmu
->read(leader
);
4221 values
[n
++] = perf_event_count(leader
);
4222 if (read_format
& PERF_FORMAT_ID
)
4223 values
[n
++] = primary_event_id(leader
);
4225 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4227 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4231 sub
->pmu
->read(sub
);
4233 values
[n
++] = perf_event_count(sub
);
4234 if (read_format
& PERF_FORMAT_ID
)
4235 values
[n
++] = primary_event_id(sub
);
4237 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4241 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
4242 PERF_FORMAT_TOTAL_TIME_RUNNING)
4244 static void perf_output_read(struct perf_output_handle
*handle
,
4245 struct perf_event
*event
)
4247 u64 enabled
= 0, running
= 0, now
, ctx_time
;
4248 u64 read_format
= event
->attr
.read_format
;
4251 * compute total_time_enabled, total_time_running
4252 * based on snapshot values taken when the event
4253 * was last scheduled in.
4255 * we cannot simply called update_context_time()
4256 * because of locking issue as we are called in
4259 if (read_format
& PERF_FORMAT_TOTAL_TIMES
) {
4261 ctx_time
= event
->shadow_ctx_time
+ now
;
4262 enabled
= ctx_time
- event
->tstamp_enabled
;
4263 running
= ctx_time
- event
->tstamp_running
;
4266 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
4267 perf_output_read_group(handle
, event
, enabled
, running
);
4269 perf_output_read_one(handle
, event
, enabled
, running
);
4272 void perf_output_sample(struct perf_output_handle
*handle
,
4273 struct perf_event_header
*header
,
4274 struct perf_sample_data
*data
,
4275 struct perf_event
*event
)
4277 u64 sample_type
= data
->type
;
4279 perf_output_put(handle
, *header
);
4281 if (sample_type
& PERF_SAMPLE_IP
)
4282 perf_output_put(handle
, data
->ip
);
4284 if (sample_type
& PERF_SAMPLE_TID
)
4285 perf_output_put(handle
, data
->tid_entry
);
4287 if (sample_type
& PERF_SAMPLE_TIME
)
4288 perf_output_put(handle
, data
->time
);
4290 if (sample_type
& PERF_SAMPLE_ADDR
)
4291 perf_output_put(handle
, data
->addr
);
4293 if (sample_type
& PERF_SAMPLE_ID
)
4294 perf_output_put(handle
, data
->id
);
4296 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4297 perf_output_put(handle
, data
->stream_id
);
4299 if (sample_type
& PERF_SAMPLE_CPU
)
4300 perf_output_put(handle
, data
->cpu_entry
);
4302 if (sample_type
& PERF_SAMPLE_PERIOD
)
4303 perf_output_put(handle
, data
->period
);
4305 if (sample_type
& PERF_SAMPLE_READ
)
4306 perf_output_read(handle
, event
);
4308 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4309 if (data
->callchain
) {
4312 if (data
->callchain
)
4313 size
+= data
->callchain
->nr
;
4315 size
*= sizeof(u64
);
4317 perf_output_copy(handle
, data
->callchain
, size
);
4320 perf_output_put(handle
, nr
);
4324 if (sample_type
& PERF_SAMPLE_RAW
) {
4326 perf_output_put(handle
, data
->raw
->size
);
4327 perf_output_copy(handle
, data
->raw
->data
,
4334 .size
= sizeof(u32
),
4337 perf_output_put(handle
, raw
);
4342 void perf_prepare_sample(struct perf_event_header
*header
,
4343 struct perf_sample_data
*data
,
4344 struct perf_event
*event
,
4345 struct pt_regs
*regs
)
4347 u64 sample_type
= event
->attr
.sample_type
;
4349 header
->type
= PERF_RECORD_SAMPLE
;
4350 header
->size
= sizeof(*header
) + event
->header_size
;
4353 header
->misc
|= perf_misc_flags(regs
);
4355 __perf_event_header__init_id(header
, data
, event
);
4357 if (sample_type
& PERF_SAMPLE_IP
)
4358 data
->ip
= perf_instruction_pointer(regs
);
4360 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4363 data
->callchain
= perf_callchain(regs
);
4365 if (data
->callchain
)
4366 size
+= data
->callchain
->nr
;
4368 header
->size
+= size
* sizeof(u64
);
4371 if (sample_type
& PERF_SAMPLE_RAW
) {
4372 int size
= sizeof(u32
);
4375 size
+= data
->raw
->size
;
4377 size
+= sizeof(u32
);
4379 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4380 header
->size
+= size
;
4384 static void perf_event_output(struct perf_event
*event
, int nmi
,
4385 struct perf_sample_data
*data
,
4386 struct pt_regs
*regs
)
4388 struct perf_output_handle handle
;
4389 struct perf_event_header header
;
4391 /* protect the callchain buffers */
4394 perf_prepare_sample(&header
, data
, event
, regs
);
4396 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
4399 perf_output_sample(&handle
, &header
, data
, event
);
4401 perf_output_end(&handle
);
4411 struct perf_read_event
{
4412 struct perf_event_header header
;
4419 perf_event_read_event(struct perf_event
*event
,
4420 struct task_struct
*task
)
4422 struct perf_output_handle handle
;
4423 struct perf_sample_data sample
;
4424 struct perf_read_event read_event
= {
4426 .type
= PERF_RECORD_READ
,
4428 .size
= sizeof(read_event
) + event
->read_size
,
4430 .pid
= perf_event_pid(event
, task
),
4431 .tid
= perf_event_tid(event
, task
),
4435 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4436 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
4440 perf_output_put(&handle
, read_event
);
4441 perf_output_read(&handle
, event
);
4442 perf_event__output_id_sample(event
, &handle
, &sample
);
4444 perf_output_end(&handle
);
4448 * task tracking -- fork/exit
4450 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
4453 struct perf_task_event
{
4454 struct task_struct
*task
;
4455 struct perf_event_context
*task_ctx
;
4458 struct perf_event_header header
;
4468 static void perf_event_task_output(struct perf_event
*event
,
4469 struct perf_task_event
*task_event
)
4471 struct perf_output_handle handle
;
4472 struct perf_sample_data sample
;
4473 struct task_struct
*task
= task_event
->task
;
4474 int ret
, size
= task_event
->event_id
.header
.size
;
4476 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4478 ret
= perf_output_begin(&handle
, event
,
4479 task_event
->event_id
.header
.size
, 0, 0);
4483 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4484 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4486 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4487 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4489 perf_output_put(&handle
, task_event
->event_id
);
4491 perf_event__output_id_sample(event
, &handle
, &sample
);
4493 perf_output_end(&handle
);
4495 task_event
->event_id
.header
.size
= size
;
4498 static int perf_event_task_match(struct perf_event
*event
)
4500 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4503 if (!event_filter_match(event
))
4506 if (event
->attr
.comm
|| event
->attr
.mmap
||
4507 event
->attr
.mmap_data
|| event
->attr
.task
)
4513 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
4514 struct perf_task_event
*task_event
)
4516 struct perf_event
*event
;
4518 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4519 if (perf_event_task_match(event
))
4520 perf_event_task_output(event
, task_event
);
4524 static void perf_event_task_event(struct perf_task_event
*task_event
)
4526 struct perf_cpu_context
*cpuctx
;
4527 struct perf_event_context
*ctx
;
4532 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4533 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4534 if (cpuctx
->active_pmu
!= pmu
)
4536 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
4538 ctx
= task_event
->task_ctx
;
4540 ctxn
= pmu
->task_ctx_nr
;
4543 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4546 perf_event_task_ctx(ctx
, task_event
);
4548 put_cpu_ptr(pmu
->pmu_cpu_context
);
4553 static void perf_event_task(struct task_struct
*task
,
4554 struct perf_event_context
*task_ctx
,
4557 struct perf_task_event task_event
;
4559 if (!atomic_read(&nr_comm_events
) &&
4560 !atomic_read(&nr_mmap_events
) &&
4561 !atomic_read(&nr_task_events
))
4564 task_event
= (struct perf_task_event
){
4566 .task_ctx
= task_ctx
,
4569 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4571 .size
= sizeof(task_event
.event_id
),
4577 .time
= perf_clock(),
4581 perf_event_task_event(&task_event
);
4584 void perf_event_fork(struct task_struct
*task
)
4586 perf_event_task(task
, NULL
, 1);
4593 struct perf_comm_event
{
4594 struct task_struct
*task
;
4599 struct perf_event_header header
;
4606 static void perf_event_comm_output(struct perf_event
*event
,
4607 struct perf_comm_event
*comm_event
)
4609 struct perf_output_handle handle
;
4610 struct perf_sample_data sample
;
4611 int size
= comm_event
->event_id
.header
.size
;
4614 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4615 ret
= perf_output_begin(&handle
, event
,
4616 comm_event
->event_id
.header
.size
, 0, 0);
4621 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4622 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4624 perf_output_put(&handle
, comm_event
->event_id
);
4625 perf_output_copy(&handle
, comm_event
->comm
,
4626 comm_event
->comm_size
);
4628 perf_event__output_id_sample(event
, &handle
, &sample
);
4630 perf_output_end(&handle
);
4632 comm_event
->event_id
.header
.size
= size
;
4635 static int perf_event_comm_match(struct perf_event
*event
)
4637 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4640 if (!event_filter_match(event
))
4643 if (event
->attr
.comm
)
4649 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4650 struct perf_comm_event
*comm_event
)
4652 struct perf_event
*event
;
4654 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4655 if (perf_event_comm_match(event
))
4656 perf_event_comm_output(event
, comm_event
);
4660 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4662 struct perf_cpu_context
*cpuctx
;
4663 struct perf_event_context
*ctx
;
4664 char comm
[TASK_COMM_LEN
];
4669 memset(comm
, 0, sizeof(comm
));
4670 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4671 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4673 comm_event
->comm
= comm
;
4674 comm_event
->comm_size
= size
;
4676 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4678 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4679 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4680 if (cpuctx
->active_pmu
!= pmu
)
4682 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4684 ctxn
= pmu
->task_ctx_nr
;
4688 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4690 perf_event_comm_ctx(ctx
, comm_event
);
4692 put_cpu_ptr(pmu
->pmu_cpu_context
);
4697 void perf_event_comm(struct task_struct
*task
)
4699 struct perf_comm_event comm_event
;
4700 struct perf_event_context
*ctx
;
4703 for_each_task_context_nr(ctxn
) {
4704 ctx
= task
->perf_event_ctxp
[ctxn
];
4708 perf_event_enable_on_exec(ctx
);
4711 if (!atomic_read(&nr_comm_events
))
4714 comm_event
= (struct perf_comm_event
){
4720 .type
= PERF_RECORD_COMM
,
4729 perf_event_comm_event(&comm_event
);
4736 struct perf_mmap_event
{
4737 struct vm_area_struct
*vma
;
4739 const char *file_name
;
4743 struct perf_event_header header
;
4753 static void perf_event_mmap_output(struct perf_event
*event
,
4754 struct perf_mmap_event
*mmap_event
)
4756 struct perf_output_handle handle
;
4757 struct perf_sample_data sample
;
4758 int size
= mmap_event
->event_id
.header
.size
;
4761 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4762 ret
= perf_output_begin(&handle
, event
,
4763 mmap_event
->event_id
.header
.size
, 0, 0);
4767 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4768 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4770 perf_output_put(&handle
, mmap_event
->event_id
);
4771 perf_output_copy(&handle
, mmap_event
->file_name
,
4772 mmap_event
->file_size
);
4774 perf_event__output_id_sample(event
, &handle
, &sample
);
4776 perf_output_end(&handle
);
4778 mmap_event
->event_id
.header
.size
= size
;
4781 static int perf_event_mmap_match(struct perf_event
*event
,
4782 struct perf_mmap_event
*mmap_event
,
4785 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4788 if (!event_filter_match(event
))
4791 if ((!executable
&& event
->attr
.mmap_data
) ||
4792 (executable
&& event
->attr
.mmap
))
4798 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4799 struct perf_mmap_event
*mmap_event
,
4802 struct perf_event
*event
;
4804 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4805 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4806 perf_event_mmap_output(event
, mmap_event
);
4810 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4812 struct perf_cpu_context
*cpuctx
;
4813 struct perf_event_context
*ctx
;
4814 struct vm_area_struct
*vma
= mmap_event
->vma
;
4815 struct file
*file
= vma
->vm_file
;
4823 memset(tmp
, 0, sizeof(tmp
));
4827 * d_path works from the end of the buffer backwards, so we
4828 * need to add enough zero bytes after the string to handle
4829 * the 64bit alignment we do later.
4831 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4833 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4836 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4838 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4842 if (arch_vma_name(mmap_event
->vma
)) {
4843 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4849 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4851 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4852 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4853 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4855 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4856 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4857 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4861 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4866 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4868 mmap_event
->file_name
= name
;
4869 mmap_event
->file_size
= size
;
4871 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4874 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4875 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4876 if (cpuctx
->active_pmu
!= pmu
)
4878 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4879 vma
->vm_flags
& VM_EXEC
);
4881 ctxn
= pmu
->task_ctx_nr
;
4885 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4887 perf_event_mmap_ctx(ctx
, mmap_event
,
4888 vma
->vm_flags
& VM_EXEC
);
4891 put_cpu_ptr(pmu
->pmu_cpu_context
);
4898 void perf_event_mmap(struct vm_area_struct
*vma
)
4900 struct perf_mmap_event mmap_event
;
4902 if (!atomic_read(&nr_mmap_events
))
4905 mmap_event
= (struct perf_mmap_event
){
4911 .type
= PERF_RECORD_MMAP
,
4912 .misc
= PERF_RECORD_MISC_USER
,
4917 .start
= vma
->vm_start
,
4918 .len
= vma
->vm_end
- vma
->vm_start
,
4919 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4923 perf_event_mmap_event(&mmap_event
);
4927 * IRQ throttle logging
4930 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4932 struct perf_output_handle handle
;
4933 struct perf_sample_data sample
;
4937 struct perf_event_header header
;
4941 } throttle_event
= {
4943 .type
= PERF_RECORD_THROTTLE
,
4945 .size
= sizeof(throttle_event
),
4947 .time
= perf_clock(),
4948 .id
= primary_event_id(event
),
4949 .stream_id
= event
->id
,
4953 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4955 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4957 ret
= perf_output_begin(&handle
, event
,
4958 throttle_event
.header
.size
, 1, 0);
4962 perf_output_put(&handle
, throttle_event
);
4963 perf_event__output_id_sample(event
, &handle
, &sample
);
4964 perf_output_end(&handle
);
4968 * Generic event overflow handling, sampling.
4971 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
4972 int throttle
, struct perf_sample_data
*data
,
4973 struct pt_regs
*regs
)
4975 int events
= atomic_read(&event
->event_limit
);
4976 struct hw_perf_event
*hwc
= &event
->hw
;
4980 * Non-sampling counters might still use the PMI to fold short
4981 * hardware counters, ignore those.
4983 if (unlikely(!is_sampling_event(event
)))
4986 if (unlikely(hwc
->interrupts
>= max_samples_per_tick
)) {
4988 hwc
->interrupts
= MAX_INTERRUPTS
;
4989 perf_log_throttle(event
, 0);
4995 if (event
->attr
.freq
) {
4996 u64 now
= perf_clock();
4997 s64 delta
= now
- hwc
->freq_time_stamp
;
4999 hwc
->freq_time_stamp
= now
;
5001 if (delta
> 0 && delta
< 2*TICK_NSEC
)
5002 perf_adjust_period(event
, delta
, hwc
->last_period
);
5006 * XXX event_limit might not quite work as expected on inherited
5010 event
->pending_kill
= POLL_IN
;
5011 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
5013 event
->pending_kill
= POLL_HUP
;
5015 event
->pending_disable
= 1;
5016 irq_work_queue(&event
->pending
);
5018 perf_event_disable(event
);
5021 if (event
->overflow_handler
)
5022 event
->overflow_handler(event
, nmi
, data
, regs
);
5024 perf_event_output(event
, nmi
, data
, regs
);
5029 int perf_event_overflow(struct perf_event
*event
, int nmi
,
5030 struct perf_sample_data
*data
,
5031 struct pt_regs
*regs
)
5033 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
5037 * Generic software event infrastructure
5040 struct swevent_htable
{
5041 struct swevent_hlist
*swevent_hlist
;
5042 struct mutex hlist_mutex
;
5045 /* Recursion avoidance in each contexts */
5046 int recursion
[PERF_NR_CONTEXTS
];
5049 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
5052 * We directly increment event->count and keep a second value in
5053 * event->hw.period_left to count intervals. This period event
5054 * is kept in the range [-sample_period, 0] so that we can use the
5058 static u64
perf_swevent_set_period(struct perf_event
*event
)
5060 struct hw_perf_event
*hwc
= &event
->hw
;
5061 u64 period
= hwc
->last_period
;
5065 hwc
->last_period
= hwc
->sample_period
;
5068 old
= val
= local64_read(&hwc
->period_left
);
5072 nr
= div64_u64(period
+ val
, period
);
5073 offset
= nr
* period
;
5075 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
5081 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
5082 int nmi
, struct perf_sample_data
*data
,
5083 struct pt_regs
*regs
)
5085 struct hw_perf_event
*hwc
= &event
->hw
;
5088 data
->period
= event
->hw
.last_period
;
5090 overflow
= perf_swevent_set_period(event
);
5092 if (hwc
->interrupts
== MAX_INTERRUPTS
)
5095 for (; overflow
; overflow
--) {
5096 if (__perf_event_overflow(event
, nmi
, throttle
,
5099 * We inhibit the overflow from happening when
5100 * hwc->interrupts == MAX_INTERRUPTS.
5108 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
5109 int nmi
, struct perf_sample_data
*data
,
5110 struct pt_regs
*regs
)
5112 struct hw_perf_event
*hwc
= &event
->hw
;
5114 local64_add(nr
, &event
->count
);
5119 if (!is_sampling_event(event
))
5122 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
5123 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
5125 if (local64_add_negative(nr
, &hwc
->period_left
))
5128 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
5131 static int perf_exclude_event(struct perf_event
*event
,
5132 struct pt_regs
*regs
)
5134 if (event
->hw
.state
& PERF_HES_STOPPED
)
5138 if (event
->attr
.exclude_user
&& user_mode(regs
))
5141 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
5148 static int perf_swevent_match(struct perf_event
*event
,
5149 enum perf_type_id type
,
5151 struct perf_sample_data
*data
,
5152 struct pt_regs
*regs
)
5154 if (event
->attr
.type
!= type
)
5157 if (event
->attr
.config
!= event_id
)
5160 if (perf_exclude_event(event
, regs
))
5166 static inline u64
swevent_hash(u64 type
, u32 event_id
)
5168 u64 val
= event_id
| (type
<< 32);
5170 return hash_64(val
, SWEVENT_HLIST_BITS
);
5173 static inline struct hlist_head
*
5174 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
5176 u64 hash
= swevent_hash(type
, event_id
);
5178 return &hlist
->heads
[hash
];
5181 /* For the read side: events when they trigger */
5182 static inline struct hlist_head
*
5183 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
5185 struct swevent_hlist
*hlist
;
5187 hlist
= rcu_dereference(swhash
->swevent_hlist
);
5191 return __find_swevent_head(hlist
, type
, event_id
);
5194 /* For the event head insertion and removal in the hlist */
5195 static inline struct hlist_head
*
5196 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
5198 struct swevent_hlist
*hlist
;
5199 u32 event_id
= event
->attr
.config
;
5200 u64 type
= event
->attr
.type
;
5203 * Event scheduling is always serialized against hlist allocation
5204 * and release. Which makes the protected version suitable here.
5205 * The context lock guarantees that.
5207 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
5208 lockdep_is_held(&event
->ctx
->lock
));
5212 return __find_swevent_head(hlist
, type
, event_id
);
5215 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
5217 struct perf_sample_data
*data
,
5218 struct pt_regs
*regs
)
5220 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5221 struct perf_event
*event
;
5222 struct hlist_node
*node
;
5223 struct hlist_head
*head
;
5226 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
5230 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5231 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
5232 perf_swevent_event(event
, nr
, nmi
, data
, regs
);
5238 int perf_swevent_get_recursion_context(void)
5240 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5242 return get_recursion_context(swhash
->recursion
);
5244 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
5246 inline void perf_swevent_put_recursion_context(int rctx
)
5248 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5250 put_recursion_context(swhash
->recursion
, rctx
);
5253 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
5254 struct pt_regs
*regs
, u64 addr
)
5256 struct perf_sample_data data
;
5259 preempt_disable_notrace();
5260 rctx
= perf_swevent_get_recursion_context();
5264 perf_sample_data_init(&data
, addr
);
5266 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
5268 perf_swevent_put_recursion_context(rctx
);
5269 preempt_enable_notrace();
5272 static void perf_swevent_read(struct perf_event
*event
)
5276 static int perf_swevent_add(struct perf_event
*event
, int flags
)
5278 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5279 struct hw_perf_event
*hwc
= &event
->hw
;
5280 struct hlist_head
*head
;
5282 if (is_sampling_event(event
)) {
5283 hwc
->last_period
= hwc
->sample_period
;
5284 perf_swevent_set_period(event
);
5287 hwc
->state
= !(flags
& PERF_EF_START
);
5289 head
= find_swevent_head(swhash
, event
);
5290 if (WARN_ON_ONCE(!head
))
5293 hlist_add_head_rcu(&event
->hlist_entry
, head
);
5298 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5300 hlist_del_rcu(&event
->hlist_entry
);
5303 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5305 event
->hw
.state
= 0;
5308 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5310 event
->hw
.state
= PERF_HES_STOPPED
;
5313 /* Deref the hlist from the update side */
5314 static inline struct swevent_hlist
*
5315 swevent_hlist_deref(struct swevent_htable
*swhash
)
5317 return rcu_dereference_protected(swhash
->swevent_hlist
,
5318 lockdep_is_held(&swhash
->hlist_mutex
));
5321 static void swevent_hlist_release_rcu(struct rcu_head
*rcu_head
)
5323 struct swevent_hlist
*hlist
;
5325 hlist
= container_of(rcu_head
, struct swevent_hlist
, rcu_head
);
5329 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5331 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5336 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5337 call_rcu(&hlist
->rcu_head
, swevent_hlist_release_rcu
);
5340 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5342 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5344 mutex_lock(&swhash
->hlist_mutex
);
5346 if (!--swhash
->hlist_refcount
)
5347 swevent_hlist_release(swhash
);
5349 mutex_unlock(&swhash
->hlist_mutex
);
5352 static void swevent_hlist_put(struct perf_event
*event
)
5356 if (event
->cpu
!= -1) {
5357 swevent_hlist_put_cpu(event
, event
->cpu
);
5361 for_each_possible_cpu(cpu
)
5362 swevent_hlist_put_cpu(event
, cpu
);
5365 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5367 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5370 mutex_lock(&swhash
->hlist_mutex
);
5372 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5373 struct swevent_hlist
*hlist
;
5375 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5380 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5382 swhash
->hlist_refcount
++;
5384 mutex_unlock(&swhash
->hlist_mutex
);
5389 static int swevent_hlist_get(struct perf_event
*event
)
5392 int cpu
, failed_cpu
;
5394 if (event
->cpu
!= -1)
5395 return swevent_hlist_get_cpu(event
, event
->cpu
);
5398 for_each_possible_cpu(cpu
) {
5399 err
= swevent_hlist_get_cpu(event
, cpu
);
5409 for_each_possible_cpu(cpu
) {
5410 if (cpu
== failed_cpu
)
5412 swevent_hlist_put_cpu(event
, cpu
);
5419 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5421 static void sw_perf_event_destroy(struct perf_event
*event
)
5423 u64 event_id
= event
->attr
.config
;
5425 WARN_ON(event
->parent
);
5427 jump_label_dec(&perf_swevent_enabled
[event_id
]);
5428 swevent_hlist_put(event
);
5431 static int perf_swevent_init(struct perf_event
*event
)
5433 int event_id
= event
->attr
.config
;
5435 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5439 case PERF_COUNT_SW_CPU_CLOCK
:
5440 case PERF_COUNT_SW_TASK_CLOCK
:
5447 if (event_id
>= PERF_COUNT_SW_MAX
)
5450 if (!event
->parent
) {
5453 err
= swevent_hlist_get(event
);
5457 jump_label_inc(&perf_swevent_enabled
[event_id
]);
5458 event
->destroy
= sw_perf_event_destroy
;
5464 static struct pmu perf_swevent
= {
5465 .task_ctx_nr
= perf_sw_context
,
5467 .event_init
= perf_swevent_init
,
5468 .add
= perf_swevent_add
,
5469 .del
= perf_swevent_del
,
5470 .start
= perf_swevent_start
,
5471 .stop
= perf_swevent_stop
,
5472 .read
= perf_swevent_read
,
5475 #ifdef CONFIG_EVENT_TRACING
5477 static int perf_tp_filter_match(struct perf_event
*event
,
5478 struct perf_sample_data
*data
)
5480 void *record
= data
->raw
->data
;
5482 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5487 static int perf_tp_event_match(struct perf_event
*event
,
5488 struct perf_sample_data
*data
,
5489 struct pt_regs
*regs
)
5491 if (event
->hw
.state
& PERF_HES_STOPPED
)
5494 * All tracepoints are from kernel-space.
5496 if (event
->attr
.exclude_kernel
)
5499 if (!perf_tp_filter_match(event
, data
))
5505 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5506 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
5508 struct perf_sample_data data
;
5509 struct perf_event
*event
;
5510 struct hlist_node
*node
;
5512 struct perf_raw_record raw
= {
5517 perf_sample_data_init(&data
, addr
);
5520 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5521 if (perf_tp_event_match(event
, &data
, regs
))
5522 perf_swevent_event(event
, count
, 1, &data
, regs
);
5525 perf_swevent_put_recursion_context(rctx
);
5527 EXPORT_SYMBOL_GPL(perf_tp_event
);
5529 static void tp_perf_event_destroy(struct perf_event
*event
)
5531 perf_trace_destroy(event
);
5534 static int perf_tp_event_init(struct perf_event
*event
)
5538 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5541 err
= perf_trace_init(event
);
5545 event
->destroy
= tp_perf_event_destroy
;
5550 static struct pmu perf_tracepoint
= {
5551 .task_ctx_nr
= perf_sw_context
,
5553 .event_init
= perf_tp_event_init
,
5554 .add
= perf_trace_add
,
5555 .del
= perf_trace_del
,
5556 .start
= perf_swevent_start
,
5557 .stop
= perf_swevent_stop
,
5558 .read
= perf_swevent_read
,
5561 static inline void perf_tp_register(void)
5563 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5566 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5571 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5574 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5575 if (IS_ERR(filter_str
))
5576 return PTR_ERR(filter_str
);
5578 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5584 static void perf_event_free_filter(struct perf_event
*event
)
5586 ftrace_profile_free_filter(event
);
5591 static inline void perf_tp_register(void)
5595 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5600 static void perf_event_free_filter(struct perf_event
*event
)
5604 #endif /* CONFIG_EVENT_TRACING */
5606 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5607 void perf_bp_event(struct perf_event
*bp
, void *data
)
5609 struct perf_sample_data sample
;
5610 struct pt_regs
*regs
= data
;
5612 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
5614 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5615 perf_swevent_event(bp
, 1, 1, &sample
, regs
);
5620 * hrtimer based swevent callback
5623 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5625 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5626 struct perf_sample_data data
;
5627 struct pt_regs
*regs
;
5628 struct perf_event
*event
;
5631 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5633 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5634 return HRTIMER_NORESTART
;
5636 event
->pmu
->read(event
);
5638 perf_sample_data_init(&data
, 0);
5639 data
.period
= event
->hw
.last_period
;
5640 regs
= get_irq_regs();
5642 if (regs
&& !perf_exclude_event(event
, regs
)) {
5643 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
5644 if (perf_event_overflow(event
, 0, &data
, regs
))
5645 ret
= HRTIMER_NORESTART
;
5648 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5649 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5654 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5656 struct hw_perf_event
*hwc
= &event
->hw
;
5659 if (!is_sampling_event(event
))
5662 period
= local64_read(&hwc
->period_left
);
5667 local64_set(&hwc
->period_left
, 0);
5669 period
= max_t(u64
, 10000, hwc
->sample_period
);
5671 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5672 ns_to_ktime(period
), 0,
5673 HRTIMER_MODE_REL_PINNED
, 0);
5676 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5678 struct hw_perf_event
*hwc
= &event
->hw
;
5680 if (is_sampling_event(event
)) {
5681 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5682 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5684 hrtimer_cancel(&hwc
->hrtimer
);
5688 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
5690 struct hw_perf_event
*hwc
= &event
->hw
;
5692 if (!is_sampling_event(event
))
5695 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5696 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5699 * Since hrtimers have a fixed rate, we can do a static freq->period
5700 * mapping and avoid the whole period adjust feedback stuff.
5702 if (event
->attr
.freq
) {
5703 long freq
= event
->attr
.sample_freq
;
5705 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
5706 hwc
->sample_period
= event
->attr
.sample_period
;
5707 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5708 event
->attr
.freq
= 0;
5713 * Software event: cpu wall time clock
5716 static void cpu_clock_event_update(struct perf_event
*event
)
5721 now
= local_clock();
5722 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5723 local64_add(now
- prev
, &event
->count
);
5726 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5728 local64_set(&event
->hw
.prev_count
, local_clock());
5729 perf_swevent_start_hrtimer(event
);
5732 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5734 perf_swevent_cancel_hrtimer(event
);
5735 cpu_clock_event_update(event
);
5738 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5740 if (flags
& PERF_EF_START
)
5741 cpu_clock_event_start(event
, flags
);
5746 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5748 cpu_clock_event_stop(event
, flags
);
5751 static void cpu_clock_event_read(struct perf_event
*event
)
5753 cpu_clock_event_update(event
);
5756 static int cpu_clock_event_init(struct perf_event
*event
)
5758 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5761 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5764 perf_swevent_init_hrtimer(event
);
5769 static struct pmu perf_cpu_clock
= {
5770 .task_ctx_nr
= perf_sw_context
,
5772 .event_init
= cpu_clock_event_init
,
5773 .add
= cpu_clock_event_add
,
5774 .del
= cpu_clock_event_del
,
5775 .start
= cpu_clock_event_start
,
5776 .stop
= cpu_clock_event_stop
,
5777 .read
= cpu_clock_event_read
,
5781 * Software event: task time clock
5784 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5789 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5791 local64_add(delta
, &event
->count
);
5794 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5796 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5797 perf_swevent_start_hrtimer(event
);
5800 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5802 perf_swevent_cancel_hrtimer(event
);
5803 task_clock_event_update(event
, event
->ctx
->time
);
5806 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5808 if (flags
& PERF_EF_START
)
5809 task_clock_event_start(event
, flags
);
5814 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5816 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5819 static void task_clock_event_read(struct perf_event
*event
)
5821 u64 now
= perf_clock();
5822 u64 delta
= now
- event
->ctx
->timestamp
;
5823 u64 time
= event
->ctx
->time
+ delta
;
5825 task_clock_event_update(event
, time
);
5828 static int task_clock_event_init(struct perf_event
*event
)
5830 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5833 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5836 perf_swevent_init_hrtimer(event
);
5841 static struct pmu perf_task_clock
= {
5842 .task_ctx_nr
= perf_sw_context
,
5844 .event_init
= task_clock_event_init
,
5845 .add
= task_clock_event_add
,
5846 .del
= task_clock_event_del
,
5847 .start
= task_clock_event_start
,
5848 .stop
= task_clock_event_stop
,
5849 .read
= task_clock_event_read
,
5852 static void perf_pmu_nop_void(struct pmu
*pmu
)
5856 static int perf_pmu_nop_int(struct pmu
*pmu
)
5861 static void perf_pmu_start_txn(struct pmu
*pmu
)
5863 perf_pmu_disable(pmu
);
5866 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5868 perf_pmu_enable(pmu
);
5872 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5874 perf_pmu_enable(pmu
);
5878 * Ensures all contexts with the same task_ctx_nr have the same
5879 * pmu_cpu_context too.
5881 static void *find_pmu_context(int ctxn
)
5888 list_for_each_entry(pmu
, &pmus
, entry
) {
5889 if (pmu
->task_ctx_nr
== ctxn
)
5890 return pmu
->pmu_cpu_context
;
5896 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5900 for_each_possible_cpu(cpu
) {
5901 struct perf_cpu_context
*cpuctx
;
5903 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5905 if (cpuctx
->active_pmu
== old_pmu
)
5906 cpuctx
->active_pmu
= pmu
;
5910 static void free_pmu_context(struct pmu
*pmu
)
5914 mutex_lock(&pmus_lock
);
5916 * Like a real lame refcount.
5918 list_for_each_entry(i
, &pmus
, entry
) {
5919 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5920 update_pmu_context(i
, pmu
);
5925 free_percpu(pmu
->pmu_cpu_context
);
5927 mutex_unlock(&pmus_lock
);
5929 static struct idr pmu_idr
;
5932 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5934 struct pmu
*pmu
= dev_get_drvdata(dev
);
5936 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5939 static struct device_attribute pmu_dev_attrs
[] = {
5944 static int pmu_bus_running
;
5945 static struct bus_type pmu_bus
= {
5946 .name
= "event_source",
5947 .dev_attrs
= pmu_dev_attrs
,
5950 static void pmu_dev_release(struct device
*dev
)
5955 static int pmu_dev_alloc(struct pmu
*pmu
)
5959 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5963 device_initialize(pmu
->dev
);
5964 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5968 dev_set_drvdata(pmu
->dev
, pmu
);
5969 pmu
->dev
->bus
= &pmu_bus
;
5970 pmu
->dev
->release
= pmu_dev_release
;
5971 ret
= device_add(pmu
->dev
);
5979 put_device(pmu
->dev
);
5983 static struct lock_class_key cpuctx_mutex
;
5985 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5989 mutex_lock(&pmus_lock
);
5991 pmu
->pmu_disable_count
= alloc_percpu(int);
5992 if (!pmu
->pmu_disable_count
)
6001 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
6005 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
6013 if (pmu_bus_running
) {
6014 ret
= pmu_dev_alloc(pmu
);
6020 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
6021 if (pmu
->pmu_cpu_context
)
6022 goto got_cpu_context
;
6024 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
6025 if (!pmu
->pmu_cpu_context
)
6028 for_each_possible_cpu(cpu
) {
6029 struct perf_cpu_context
*cpuctx
;
6031 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6032 __perf_event_init_context(&cpuctx
->ctx
);
6033 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
6034 cpuctx
->ctx
.type
= cpu_context
;
6035 cpuctx
->ctx
.pmu
= pmu
;
6036 cpuctx
->jiffies_interval
= 1;
6037 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
6038 cpuctx
->active_pmu
= pmu
;
6042 if (!pmu
->start_txn
) {
6043 if (pmu
->pmu_enable
) {
6045 * If we have pmu_enable/pmu_disable calls, install
6046 * transaction stubs that use that to try and batch
6047 * hardware accesses.
6049 pmu
->start_txn
= perf_pmu_start_txn
;
6050 pmu
->commit_txn
= perf_pmu_commit_txn
;
6051 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
6053 pmu
->start_txn
= perf_pmu_nop_void
;
6054 pmu
->commit_txn
= perf_pmu_nop_int
;
6055 pmu
->cancel_txn
= perf_pmu_nop_void
;
6059 if (!pmu
->pmu_enable
) {
6060 pmu
->pmu_enable
= perf_pmu_nop_void
;
6061 pmu
->pmu_disable
= perf_pmu_nop_void
;
6064 list_add_rcu(&pmu
->entry
, &pmus
);
6067 mutex_unlock(&pmus_lock
);
6072 device_del(pmu
->dev
);
6073 put_device(pmu
->dev
);
6076 if (pmu
->type
>= PERF_TYPE_MAX
)
6077 idr_remove(&pmu_idr
, pmu
->type
);
6080 free_percpu(pmu
->pmu_disable_count
);
6084 void perf_pmu_unregister(struct pmu
*pmu
)
6086 mutex_lock(&pmus_lock
);
6087 list_del_rcu(&pmu
->entry
);
6088 mutex_unlock(&pmus_lock
);
6091 * We dereference the pmu list under both SRCU and regular RCU, so
6092 * synchronize against both of those.
6094 synchronize_srcu(&pmus_srcu
);
6097 free_percpu(pmu
->pmu_disable_count
);
6098 if (pmu
->type
>= PERF_TYPE_MAX
)
6099 idr_remove(&pmu_idr
, pmu
->type
);
6100 device_del(pmu
->dev
);
6101 put_device(pmu
->dev
);
6102 free_pmu_context(pmu
);
6105 struct pmu
*perf_init_event(struct perf_event
*event
)
6107 struct pmu
*pmu
= NULL
;
6111 idx
= srcu_read_lock(&pmus_srcu
);
6114 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
6117 ret
= pmu
->event_init(event
);
6123 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6124 ret
= pmu
->event_init(event
);
6128 if (ret
!= -ENOENT
) {
6133 pmu
= ERR_PTR(-ENOENT
);
6135 srcu_read_unlock(&pmus_srcu
, idx
);
6141 * Allocate and initialize a event structure
6143 static struct perf_event
*
6144 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
6145 struct task_struct
*task
,
6146 struct perf_event
*group_leader
,
6147 struct perf_event
*parent_event
,
6148 perf_overflow_handler_t overflow_handler
)
6151 struct perf_event
*event
;
6152 struct hw_perf_event
*hwc
;
6155 if ((unsigned)cpu
>= nr_cpu_ids
) {
6156 if (!task
|| cpu
!= -1)
6157 return ERR_PTR(-EINVAL
);
6160 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
6162 return ERR_PTR(-ENOMEM
);
6165 * Single events are their own group leaders, with an
6166 * empty sibling list:
6169 group_leader
= event
;
6171 mutex_init(&event
->child_mutex
);
6172 INIT_LIST_HEAD(&event
->child_list
);
6174 INIT_LIST_HEAD(&event
->group_entry
);
6175 INIT_LIST_HEAD(&event
->event_entry
);
6176 INIT_LIST_HEAD(&event
->sibling_list
);
6177 init_waitqueue_head(&event
->waitq
);
6178 init_irq_work(&event
->pending
, perf_pending_event
);
6180 mutex_init(&event
->mmap_mutex
);
6183 event
->attr
= *attr
;
6184 event
->group_leader
= group_leader
;
6188 event
->parent
= parent_event
;
6190 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
6191 event
->id
= atomic64_inc_return(&perf_event_id
);
6193 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6196 event
->attach_state
= PERF_ATTACH_TASK
;
6197 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6199 * hw_breakpoint is a bit difficult here..
6201 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
6202 event
->hw
.bp_target
= task
;
6206 if (!overflow_handler
&& parent_event
)
6207 overflow_handler
= parent_event
->overflow_handler
;
6209 event
->overflow_handler
= overflow_handler
;
6212 event
->state
= PERF_EVENT_STATE_OFF
;
6217 hwc
->sample_period
= attr
->sample_period
;
6218 if (attr
->freq
&& attr
->sample_freq
)
6219 hwc
->sample_period
= 1;
6220 hwc
->last_period
= hwc
->sample_period
;
6222 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6225 * we currently do not support PERF_FORMAT_GROUP on inherited events
6227 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
6230 pmu
= perf_init_event(event
);
6236 else if (IS_ERR(pmu
))
6241 put_pid_ns(event
->ns
);
6243 return ERR_PTR(err
);
6248 if (!event
->parent
) {
6249 if (event
->attach_state
& PERF_ATTACH_TASK
)
6250 jump_label_inc(&perf_sched_events
);
6251 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
6252 atomic_inc(&nr_mmap_events
);
6253 if (event
->attr
.comm
)
6254 atomic_inc(&nr_comm_events
);
6255 if (event
->attr
.task
)
6256 atomic_inc(&nr_task_events
);
6257 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6258 err
= get_callchain_buffers();
6261 return ERR_PTR(err
);
6269 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6270 struct perf_event_attr
*attr
)
6275 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6279 * zero the full structure, so that a short copy will be nice.
6281 memset(attr
, 0, sizeof(*attr
));
6283 ret
= get_user(size
, &uattr
->size
);
6287 if (size
> PAGE_SIZE
) /* silly large */
6290 if (!size
) /* abi compat */
6291 size
= PERF_ATTR_SIZE_VER0
;
6293 if (size
< PERF_ATTR_SIZE_VER0
)
6297 * If we're handed a bigger struct than we know of,
6298 * ensure all the unknown bits are 0 - i.e. new
6299 * user-space does not rely on any kernel feature
6300 * extensions we dont know about yet.
6302 if (size
> sizeof(*attr
)) {
6303 unsigned char __user
*addr
;
6304 unsigned char __user
*end
;
6307 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6308 end
= (void __user
*)uattr
+ size
;
6310 for (; addr
< end
; addr
++) {
6311 ret
= get_user(val
, addr
);
6317 size
= sizeof(*attr
);
6320 ret
= copy_from_user(attr
, uattr
, size
);
6325 * If the type exists, the corresponding creation will verify
6328 if (attr
->type
>= PERF_TYPE_MAX
)
6331 if (attr
->__reserved_1
)
6334 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6337 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6344 put_user(sizeof(*attr
), &uattr
->size
);
6350 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
6352 struct perf_buffer
*buffer
= NULL
, *old_buffer
= NULL
;
6358 /* don't allow circular references */
6359 if (event
== output_event
)
6363 * Don't allow cross-cpu buffers
6365 if (output_event
->cpu
!= event
->cpu
)
6369 * If its not a per-cpu buffer, it must be the same task.
6371 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
6375 mutex_lock(&event
->mmap_mutex
);
6376 /* Can't redirect output if we've got an active mmap() */
6377 if (atomic_read(&event
->mmap_count
))
6381 /* get the buffer we want to redirect to */
6382 buffer
= perf_buffer_get(output_event
);
6387 old_buffer
= event
->buffer
;
6388 rcu_assign_pointer(event
->buffer
, buffer
);
6391 mutex_unlock(&event
->mmap_mutex
);
6394 perf_buffer_put(old_buffer
);
6400 * sys_perf_event_open - open a performance event, associate it to a task/cpu
6402 * @attr_uptr: event_id type attributes for monitoring/sampling
6405 * @group_fd: group leader event fd
6407 SYSCALL_DEFINE5(perf_event_open
,
6408 struct perf_event_attr __user
*, attr_uptr
,
6409 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
6411 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
6412 struct perf_event
*event
, *sibling
;
6413 struct perf_event_attr attr
;
6414 struct perf_event_context
*ctx
;
6415 struct file
*event_file
= NULL
;
6416 struct file
*group_file
= NULL
;
6417 struct task_struct
*task
= NULL
;
6421 int fput_needed
= 0;
6424 /* for future expandability... */
6425 if (flags
& ~PERF_FLAG_ALL
)
6428 err
= perf_copy_attr(attr_uptr
, &attr
);
6432 if (!attr
.exclude_kernel
) {
6433 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6438 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
6443 * In cgroup mode, the pid argument is used to pass the fd
6444 * opened to the cgroup directory in cgroupfs. The cpu argument
6445 * designates the cpu on which to monitor threads from that
6448 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
6451 event_fd
= get_unused_fd_flags(O_RDWR
);
6455 if (group_fd
!= -1) {
6456 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
6457 if (IS_ERR(group_leader
)) {
6458 err
= PTR_ERR(group_leader
);
6461 group_file
= group_leader
->filp
;
6462 if (flags
& PERF_FLAG_FD_OUTPUT
)
6463 output_event
= group_leader
;
6464 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6465 group_leader
= NULL
;
6468 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6469 task
= find_lively_task_by_vpid(pid
);
6471 err
= PTR_ERR(task
);
6476 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
, NULL
);
6477 if (IS_ERR(event
)) {
6478 err
= PTR_ERR(event
);
6482 if (flags
& PERF_FLAG_PID_CGROUP
) {
6483 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6488 * - that has cgroup constraint on event->cpu
6489 * - that may need work on context switch
6491 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
6492 jump_label_inc(&perf_sched_events
);
6496 * Special case software events and allow them to be part of
6497 * any hardware group.
6502 (is_software_event(event
) != is_software_event(group_leader
))) {
6503 if (is_software_event(event
)) {
6505 * If event and group_leader are not both a software
6506 * event, and event is, then group leader is not.
6508 * Allow the addition of software events to !software
6509 * groups, this is safe because software events never
6512 pmu
= group_leader
->pmu
;
6513 } else if (is_software_event(group_leader
) &&
6514 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6516 * In case the group is a pure software group, and we
6517 * try to add a hardware event, move the whole group to
6518 * the hardware context.
6525 * Get the target context (task or percpu):
6527 ctx
= find_get_context(pmu
, task
, cpu
);
6534 * Look up the group leader (we will attach this event to it):
6540 * Do not allow a recursive hierarchy (this new sibling
6541 * becoming part of another group-sibling):
6543 if (group_leader
->group_leader
!= group_leader
)
6546 * Do not allow to attach to a group in a different
6547 * task or CPU context:
6550 if (group_leader
->ctx
->type
!= ctx
->type
)
6553 if (group_leader
->ctx
!= ctx
)
6558 * Only a group leader can be exclusive or pinned
6560 if (attr
.exclusive
|| attr
.pinned
)
6565 err
= perf_event_set_output(event
, output_event
);
6570 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6571 if (IS_ERR(event_file
)) {
6572 err
= PTR_ERR(event_file
);
6577 struct perf_event_context
*gctx
= group_leader
->ctx
;
6579 mutex_lock(&gctx
->mutex
);
6580 perf_remove_from_context(group_leader
);
6581 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6583 perf_remove_from_context(sibling
);
6586 mutex_unlock(&gctx
->mutex
);
6590 event
->filp
= event_file
;
6591 WARN_ON_ONCE(ctx
->parent_ctx
);
6592 mutex_lock(&ctx
->mutex
);
6595 perf_install_in_context(ctx
, group_leader
, cpu
);
6597 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6599 perf_install_in_context(ctx
, sibling
, cpu
);
6604 perf_install_in_context(ctx
, event
, cpu
);
6606 perf_unpin_context(ctx
);
6607 mutex_unlock(&ctx
->mutex
);
6609 event
->owner
= current
;
6611 mutex_lock(¤t
->perf_event_mutex
);
6612 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6613 mutex_unlock(¤t
->perf_event_mutex
);
6616 * Precalculate sample_data sizes
6618 perf_event__header_size(event
);
6619 perf_event__id_header_size(event
);
6622 * Drop the reference on the group_event after placing the
6623 * new event on the sibling_list. This ensures destruction
6624 * of the group leader will find the pointer to itself in
6625 * perf_group_detach().
6627 fput_light(group_file
, fput_needed
);
6628 fd_install(event_fd
, event_file
);
6632 perf_unpin_context(ctx
);
6638 put_task_struct(task
);
6640 fput_light(group_file
, fput_needed
);
6642 put_unused_fd(event_fd
);
6647 * perf_event_create_kernel_counter
6649 * @attr: attributes of the counter to create
6650 * @cpu: cpu in which the counter is bound
6651 * @task: task to profile (NULL for percpu)
6654 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6655 struct task_struct
*task
,
6656 perf_overflow_handler_t overflow_handler
)
6658 struct perf_event_context
*ctx
;
6659 struct perf_event
*event
;
6663 * Get the target context (task or percpu):
6666 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
, overflow_handler
);
6667 if (IS_ERR(event
)) {
6668 err
= PTR_ERR(event
);
6672 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6679 WARN_ON_ONCE(ctx
->parent_ctx
);
6680 mutex_lock(&ctx
->mutex
);
6681 perf_install_in_context(ctx
, event
, cpu
);
6683 perf_unpin_context(ctx
);
6684 mutex_unlock(&ctx
->mutex
);
6691 return ERR_PTR(err
);
6693 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6695 static void sync_child_event(struct perf_event
*child_event
,
6696 struct task_struct
*child
)
6698 struct perf_event
*parent_event
= child_event
->parent
;
6701 if (child_event
->attr
.inherit_stat
)
6702 perf_event_read_event(child_event
, child
);
6704 child_val
= perf_event_count(child_event
);
6707 * Add back the child's count to the parent's count:
6709 atomic64_add(child_val
, &parent_event
->child_count
);
6710 atomic64_add(child_event
->total_time_enabled
,
6711 &parent_event
->child_total_time_enabled
);
6712 atomic64_add(child_event
->total_time_running
,
6713 &parent_event
->child_total_time_running
);
6716 * Remove this event from the parent's list
6718 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6719 mutex_lock(&parent_event
->child_mutex
);
6720 list_del_init(&child_event
->child_list
);
6721 mutex_unlock(&parent_event
->child_mutex
);
6724 * Release the parent event, if this was the last
6727 fput(parent_event
->filp
);
6731 __perf_event_exit_task(struct perf_event
*child_event
,
6732 struct perf_event_context
*child_ctx
,
6733 struct task_struct
*child
)
6735 if (child_event
->parent
) {
6736 raw_spin_lock_irq(&child_ctx
->lock
);
6737 perf_group_detach(child_event
);
6738 raw_spin_unlock_irq(&child_ctx
->lock
);
6741 perf_remove_from_context(child_event
);
6744 * It can happen that the parent exits first, and has events
6745 * that are still around due to the child reference. These
6746 * events need to be zapped.
6748 if (child_event
->parent
) {
6749 sync_child_event(child_event
, child
);
6750 free_event(child_event
);
6754 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6756 struct perf_event
*child_event
, *tmp
;
6757 struct perf_event_context
*child_ctx
;
6758 unsigned long flags
;
6760 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6761 perf_event_task(child
, NULL
, 0);
6765 local_irq_save(flags
);
6767 * We can't reschedule here because interrupts are disabled,
6768 * and either child is current or it is a task that can't be
6769 * scheduled, so we are now safe from rescheduling changing
6772 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6773 task_ctx_sched_out(child_ctx
, EVENT_ALL
);
6776 * Take the context lock here so that if find_get_context is
6777 * reading child->perf_event_ctxp, we wait until it has
6778 * incremented the context's refcount before we do put_ctx below.
6780 raw_spin_lock(&child_ctx
->lock
);
6781 child
->perf_event_ctxp
[ctxn
] = NULL
;
6783 * If this context is a clone; unclone it so it can't get
6784 * swapped to another process while we're removing all
6785 * the events from it.
6787 unclone_ctx(child_ctx
);
6788 update_context_time(child_ctx
);
6789 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6792 * Report the task dead after unscheduling the events so that we
6793 * won't get any samples after PERF_RECORD_EXIT. We can however still
6794 * get a few PERF_RECORD_READ events.
6796 perf_event_task(child
, child_ctx
, 0);
6799 * We can recurse on the same lock type through:
6801 * __perf_event_exit_task()
6802 * sync_child_event()
6803 * fput(parent_event->filp)
6805 * mutex_lock(&ctx->mutex)
6807 * But since its the parent context it won't be the same instance.
6809 mutex_lock(&child_ctx
->mutex
);
6812 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6814 __perf_event_exit_task(child_event
, child_ctx
, child
);
6816 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6818 __perf_event_exit_task(child_event
, child_ctx
, child
);
6821 * If the last event was a group event, it will have appended all
6822 * its siblings to the list, but we obtained 'tmp' before that which
6823 * will still point to the list head terminating the iteration.
6825 if (!list_empty(&child_ctx
->pinned_groups
) ||
6826 !list_empty(&child_ctx
->flexible_groups
))
6829 mutex_unlock(&child_ctx
->mutex
);
6835 * When a child task exits, feed back event values to parent events.
6837 void perf_event_exit_task(struct task_struct
*child
)
6839 struct perf_event
*event
, *tmp
;
6842 mutex_lock(&child
->perf_event_mutex
);
6843 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6845 list_del_init(&event
->owner_entry
);
6848 * Ensure the list deletion is visible before we clear
6849 * the owner, closes a race against perf_release() where
6850 * we need to serialize on the owner->perf_event_mutex.
6853 event
->owner
= NULL
;
6855 mutex_unlock(&child
->perf_event_mutex
);
6857 for_each_task_context_nr(ctxn
)
6858 perf_event_exit_task_context(child
, ctxn
);
6861 static void perf_free_event(struct perf_event
*event
,
6862 struct perf_event_context
*ctx
)
6864 struct perf_event
*parent
= event
->parent
;
6866 if (WARN_ON_ONCE(!parent
))
6869 mutex_lock(&parent
->child_mutex
);
6870 list_del_init(&event
->child_list
);
6871 mutex_unlock(&parent
->child_mutex
);
6875 perf_group_detach(event
);
6876 list_del_event(event
, ctx
);
6881 * free an unexposed, unused context as created by inheritance by
6882 * perf_event_init_task below, used by fork() in case of fail.
6884 void perf_event_free_task(struct task_struct
*task
)
6886 struct perf_event_context
*ctx
;
6887 struct perf_event
*event
, *tmp
;
6890 for_each_task_context_nr(ctxn
) {
6891 ctx
= task
->perf_event_ctxp
[ctxn
];
6895 mutex_lock(&ctx
->mutex
);
6897 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6899 perf_free_event(event
, ctx
);
6901 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6903 perf_free_event(event
, ctx
);
6905 if (!list_empty(&ctx
->pinned_groups
) ||
6906 !list_empty(&ctx
->flexible_groups
))
6909 mutex_unlock(&ctx
->mutex
);
6915 void perf_event_delayed_put(struct task_struct
*task
)
6919 for_each_task_context_nr(ctxn
)
6920 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6924 * inherit a event from parent task to child task:
6926 static struct perf_event
*
6927 inherit_event(struct perf_event
*parent_event
,
6928 struct task_struct
*parent
,
6929 struct perf_event_context
*parent_ctx
,
6930 struct task_struct
*child
,
6931 struct perf_event
*group_leader
,
6932 struct perf_event_context
*child_ctx
)
6934 struct perf_event
*child_event
;
6935 unsigned long flags
;
6938 * Instead of creating recursive hierarchies of events,
6939 * we link inherited events back to the original parent,
6940 * which has a filp for sure, which we use as the reference
6943 if (parent_event
->parent
)
6944 parent_event
= parent_event
->parent
;
6946 child_event
= perf_event_alloc(&parent_event
->attr
,
6949 group_leader
, parent_event
,
6951 if (IS_ERR(child_event
))
6956 * Make the child state follow the state of the parent event,
6957 * not its attr.disabled bit. We hold the parent's mutex,
6958 * so we won't race with perf_event_{en, dis}able_family.
6960 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6961 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6963 child_event
->state
= PERF_EVENT_STATE_OFF
;
6965 if (parent_event
->attr
.freq
) {
6966 u64 sample_period
= parent_event
->hw
.sample_period
;
6967 struct hw_perf_event
*hwc
= &child_event
->hw
;
6969 hwc
->sample_period
= sample_period
;
6970 hwc
->last_period
= sample_period
;
6972 local64_set(&hwc
->period_left
, sample_period
);
6975 child_event
->ctx
= child_ctx
;
6976 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6979 * Precalculate sample_data sizes
6981 perf_event__header_size(child_event
);
6982 perf_event__id_header_size(child_event
);
6985 * Link it up in the child's context:
6987 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6988 add_event_to_ctx(child_event
, child_ctx
);
6989 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6992 * Get a reference to the parent filp - we will fput it
6993 * when the child event exits. This is safe to do because
6994 * we are in the parent and we know that the filp still
6995 * exists and has a nonzero count:
6997 atomic_long_inc(&parent_event
->filp
->f_count
);
7000 * Link this into the parent event's child list
7002 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7003 mutex_lock(&parent_event
->child_mutex
);
7004 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
7005 mutex_unlock(&parent_event
->child_mutex
);
7010 static int inherit_group(struct perf_event
*parent_event
,
7011 struct task_struct
*parent
,
7012 struct perf_event_context
*parent_ctx
,
7013 struct task_struct
*child
,
7014 struct perf_event_context
*child_ctx
)
7016 struct perf_event
*leader
;
7017 struct perf_event
*sub
;
7018 struct perf_event
*child_ctr
;
7020 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
7021 child
, NULL
, child_ctx
);
7023 return PTR_ERR(leader
);
7024 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
7025 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
7026 child
, leader
, child_ctx
);
7027 if (IS_ERR(child_ctr
))
7028 return PTR_ERR(child_ctr
);
7034 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
7035 struct perf_event_context
*parent_ctx
,
7036 struct task_struct
*child
, int ctxn
,
7040 struct perf_event_context
*child_ctx
;
7042 if (!event
->attr
.inherit
) {
7047 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7050 * This is executed from the parent task context, so
7051 * inherit events that have been marked for cloning.
7052 * First allocate and initialize a context for the
7056 child_ctx
= alloc_perf_context(event
->pmu
, child
);
7060 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
7063 ret
= inherit_group(event
, parent
, parent_ctx
,
7073 * Initialize the perf_event context in task_struct
7075 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
7077 struct perf_event_context
*child_ctx
, *parent_ctx
;
7078 struct perf_event_context
*cloned_ctx
;
7079 struct perf_event
*event
;
7080 struct task_struct
*parent
= current
;
7081 int inherited_all
= 1;
7082 unsigned long flags
;
7085 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
7089 * If the parent's context is a clone, pin it so it won't get
7092 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
7095 * No need to check if parent_ctx != NULL here; since we saw
7096 * it non-NULL earlier, the only reason for it to become NULL
7097 * is if we exit, and since we're currently in the middle of
7098 * a fork we can't be exiting at the same time.
7102 * Lock the parent list. No need to lock the child - not PID
7103 * hashed yet and not running, so nobody can access it.
7105 mutex_lock(&parent_ctx
->mutex
);
7108 * We dont have to disable NMIs - we are only looking at
7109 * the list, not manipulating it:
7111 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
7112 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7113 child
, ctxn
, &inherited_all
);
7119 * We can't hold ctx->lock when iterating the ->flexible_group list due
7120 * to allocations, but we need to prevent rotation because
7121 * rotate_ctx() will change the list from interrupt context.
7123 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7124 parent_ctx
->rotate_disable
= 1;
7125 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7127 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
7128 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7129 child
, ctxn
, &inherited_all
);
7134 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7135 parent_ctx
->rotate_disable
= 0;
7137 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7139 if (child_ctx
&& inherited_all
) {
7141 * Mark the child context as a clone of the parent
7142 * context, or of whatever the parent is a clone of.
7144 * Note that if the parent is a clone, the holding of
7145 * parent_ctx->lock avoids it from being uncloned.
7147 cloned_ctx
= parent_ctx
->parent_ctx
;
7149 child_ctx
->parent_ctx
= cloned_ctx
;
7150 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
7152 child_ctx
->parent_ctx
= parent_ctx
;
7153 child_ctx
->parent_gen
= parent_ctx
->generation
;
7155 get_ctx(child_ctx
->parent_ctx
);
7158 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7159 mutex_unlock(&parent_ctx
->mutex
);
7161 perf_unpin_context(parent_ctx
);
7162 put_ctx(parent_ctx
);
7168 * Initialize the perf_event context in task_struct
7170 int perf_event_init_task(struct task_struct
*child
)
7174 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7175 mutex_init(&child
->perf_event_mutex
);
7176 INIT_LIST_HEAD(&child
->perf_event_list
);
7178 for_each_task_context_nr(ctxn
) {
7179 ret
= perf_event_init_context(child
, ctxn
);
7187 static void __init
perf_event_init_all_cpus(void)
7189 struct swevent_htable
*swhash
;
7192 for_each_possible_cpu(cpu
) {
7193 swhash
= &per_cpu(swevent_htable
, cpu
);
7194 mutex_init(&swhash
->hlist_mutex
);
7195 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7199 static void __cpuinit
perf_event_init_cpu(int cpu
)
7201 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7203 mutex_lock(&swhash
->hlist_mutex
);
7204 if (swhash
->hlist_refcount
> 0) {
7205 struct swevent_hlist
*hlist
;
7207 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7209 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7211 mutex_unlock(&swhash
->hlist_mutex
);
7214 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7215 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7217 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7219 WARN_ON(!irqs_disabled());
7221 list_del_init(&cpuctx
->rotation_list
);
7224 static void __perf_event_exit_context(void *__info
)
7226 struct perf_event_context
*ctx
= __info
;
7227 struct perf_event
*event
, *tmp
;
7229 perf_pmu_rotate_stop(ctx
->pmu
);
7231 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
7232 __perf_remove_from_context(event
);
7233 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
7234 __perf_remove_from_context(event
);
7237 static void perf_event_exit_cpu_context(int cpu
)
7239 struct perf_event_context
*ctx
;
7243 idx
= srcu_read_lock(&pmus_srcu
);
7244 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7245 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
7247 mutex_lock(&ctx
->mutex
);
7248 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
7249 mutex_unlock(&ctx
->mutex
);
7251 srcu_read_unlock(&pmus_srcu
, idx
);
7254 static void perf_event_exit_cpu(int cpu
)
7256 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7258 mutex_lock(&swhash
->hlist_mutex
);
7259 swevent_hlist_release(swhash
);
7260 mutex_unlock(&swhash
->hlist_mutex
);
7262 perf_event_exit_cpu_context(cpu
);
7265 static inline void perf_event_exit_cpu(int cpu
) { }
7269 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
7273 for_each_online_cpu(cpu
)
7274 perf_event_exit_cpu(cpu
);
7280 * Run the perf reboot notifier at the very last possible moment so that
7281 * the generic watchdog code runs as long as possible.
7283 static struct notifier_block perf_reboot_notifier
= {
7284 .notifier_call
= perf_reboot
,
7285 .priority
= INT_MIN
,
7288 static int __cpuinit
7289 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
7291 unsigned int cpu
= (long)hcpu
;
7293 switch (action
& ~CPU_TASKS_FROZEN
) {
7295 case CPU_UP_PREPARE
:
7296 case CPU_DOWN_FAILED
:
7297 perf_event_init_cpu(cpu
);
7300 case CPU_UP_CANCELED
:
7301 case CPU_DOWN_PREPARE
:
7302 perf_event_exit_cpu(cpu
);
7312 void __init
perf_event_init(void)
7318 perf_event_init_all_cpus();
7319 init_srcu_struct(&pmus_srcu
);
7320 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
7321 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
7322 perf_pmu_register(&perf_task_clock
, NULL
, -1);
7324 perf_cpu_notifier(perf_cpu_notify
);
7325 register_reboot_notifier(&perf_reboot_notifier
);
7327 ret
= init_hw_breakpoint();
7328 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
7331 static int __init
perf_event_sysfs_init(void)
7336 mutex_lock(&pmus_lock
);
7338 ret
= bus_register(&pmu_bus
);
7342 list_for_each_entry(pmu
, &pmus
, entry
) {
7343 if (!pmu
->name
|| pmu
->type
< 0)
7346 ret
= pmu_dev_alloc(pmu
);
7347 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
7349 pmu_bus_running
= 1;
7353 mutex_unlock(&pmus_lock
);
7357 device_initcall(perf_event_sysfs_init
);
7359 #ifdef CONFIG_CGROUP_PERF
7360 static struct cgroup_subsys_state
*perf_cgroup_create(
7361 struct cgroup_subsys
*ss
, struct cgroup
*cont
)
7363 struct perf_cgroup
*jc
;
7365 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
7367 return ERR_PTR(-ENOMEM
);
7369 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
7372 return ERR_PTR(-ENOMEM
);
7378 static void perf_cgroup_destroy(struct cgroup_subsys
*ss
,
7379 struct cgroup
*cont
)
7381 struct perf_cgroup
*jc
;
7382 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
7383 struct perf_cgroup
, css
);
7384 free_percpu(jc
->info
);
7388 static int __perf_cgroup_move(void *info
)
7390 struct task_struct
*task
= info
;
7391 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
7395 static void perf_cgroup_move(struct task_struct
*task
)
7397 task_function_call(task
, __perf_cgroup_move
, task
);
7400 static void perf_cgroup_attach(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
7401 struct cgroup
*old_cgrp
, struct task_struct
*task
,
7404 perf_cgroup_move(task
);
7406 struct task_struct
*c
;
7408 list_for_each_entry_rcu(c
, &task
->thread_group
, thread_group
) {
7409 perf_cgroup_move(c
);
7415 static void perf_cgroup_exit(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
7416 struct cgroup
*old_cgrp
, struct task_struct
*task
)
7419 * cgroup_exit() is called in the copy_process() failure path.
7420 * Ignore this case since the task hasn't ran yet, this avoids
7421 * trying to poke a half freed task state from generic code.
7423 if (!(task
->flags
& PF_EXITING
))
7426 perf_cgroup_move(task
);
7429 struct cgroup_subsys perf_subsys
= {
7430 .name
= "perf_event",
7431 .subsys_id
= perf_subsys_id
,
7432 .create
= perf_cgroup_create
,
7433 .destroy
= perf_cgroup_destroy
,
7434 .exit
= perf_cgroup_exit
,
7435 .attach
= perf_cgroup_attach
,
7437 #endif /* CONFIG_CGROUP_PERF */