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 int sysctl_perf_event_sample_rate __read_mostly
= 100000;
155 static atomic64_t perf_event_id
;
157 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
158 enum event_type_t event_type
);
160 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
161 enum event_type_t event_type
,
162 struct task_struct
*task
);
164 static void update_context_time(struct perf_event_context
*ctx
);
165 static u64
perf_event_time(struct perf_event
*event
);
167 void __weak
perf_event_print_debug(void) { }
169 extern __weak
const char *perf_pmu_name(void)
174 static inline u64
perf_clock(void)
176 return local_clock();
179 static inline struct perf_cpu_context
*
180 __get_cpu_context(struct perf_event_context
*ctx
)
182 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
185 #ifdef CONFIG_CGROUP_PERF
187 static inline struct perf_cgroup
*
188 perf_cgroup_from_task(struct task_struct
*task
)
190 return container_of(task_subsys_state(task
, perf_subsys_id
),
191 struct perf_cgroup
, css
);
195 perf_cgroup_match(struct perf_event
*event
)
197 struct perf_event_context
*ctx
= event
->ctx
;
198 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
200 return !event
->cgrp
|| event
->cgrp
== cpuctx
->cgrp
;
203 static inline void perf_get_cgroup(struct perf_event
*event
)
205 css_get(&event
->cgrp
->css
);
208 static inline void perf_put_cgroup(struct perf_event
*event
)
210 css_put(&event
->cgrp
->css
);
213 static inline void perf_detach_cgroup(struct perf_event
*event
)
215 perf_put_cgroup(event
);
219 static inline int is_cgroup_event(struct perf_event
*event
)
221 return event
->cgrp
!= NULL
;
224 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
226 struct perf_cgroup_info
*t
;
228 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
232 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
234 struct perf_cgroup_info
*info
;
239 info
= this_cpu_ptr(cgrp
->info
);
241 info
->time
+= now
- info
->timestamp
;
242 info
->timestamp
= now
;
245 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
247 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
249 __update_cgrp_time(cgrp_out
);
252 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
254 struct perf_cgroup
*cgrp
= perf_cgroup_from_task(current
);
256 * do not update time when cgroup is not active
258 if (!event
->cgrp
|| cgrp
!= event
->cgrp
)
261 __update_cgrp_time(event
->cgrp
);
265 perf_cgroup_set_timestamp(struct task_struct
*task
, u64 now
)
267 struct perf_cgroup
*cgrp
;
268 struct perf_cgroup_info
*info
;
273 cgrp
= perf_cgroup_from_task(task
);
274 info
= this_cpu_ptr(cgrp
->info
);
275 info
->timestamp
= now
;
278 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
279 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
282 * reschedule events based on the cgroup constraint of task.
284 * mode SWOUT : schedule out everything
285 * mode SWIN : schedule in based on cgroup for next
287 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
289 struct perf_cpu_context
*cpuctx
;
294 * disable interrupts to avoid geting nr_cgroup
295 * changes via __perf_event_disable(). Also
298 local_irq_save(flags
);
301 * we reschedule only in the presence of cgroup
302 * constrained events.
306 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
308 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
310 perf_pmu_disable(cpuctx
->ctx
.pmu
);
313 * perf_cgroup_events says at least one
314 * context on this CPU has cgroup events.
316 * ctx->nr_cgroups reports the number of cgroup
317 * events for a context.
319 if (cpuctx
->ctx
.nr_cgroups
> 0) {
321 if (mode
& PERF_CGROUP_SWOUT
) {
322 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
324 * must not be done before ctxswout due
325 * to event_filter_match() in event_sched_out()
330 if (mode
& PERF_CGROUP_SWIN
) {
331 /* set cgrp before ctxsw in to
332 * allow event_filter_match() to not
333 * have to pass task around
335 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
336 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
340 perf_pmu_enable(cpuctx
->ctx
.pmu
);
345 local_irq_restore(flags
);
348 static inline void perf_cgroup_sched_out(struct task_struct
*task
)
350 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
353 static inline void perf_cgroup_sched_in(struct task_struct
*task
)
355 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
358 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
359 struct perf_event_attr
*attr
,
360 struct perf_event
*group_leader
)
362 struct perf_cgroup
*cgrp
;
363 struct cgroup_subsys_state
*css
;
365 int ret
= 0, fput_needed
;
367 file
= fget_light(fd
, &fput_needed
);
371 css
= cgroup_css_from_dir(file
, perf_subsys_id
);
375 cgrp
= container_of(css
, struct perf_cgroup
, css
);
379 * all events in a group must monitor
380 * the same cgroup because a task belongs
381 * to only one perf cgroup at a time
383 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
384 perf_detach_cgroup(event
);
387 /* must be done before we fput() the file */
388 perf_get_cgroup(event
);
390 fput_light(file
, fput_needed
);
395 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
397 struct perf_cgroup_info
*t
;
398 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
399 event
->shadow_ctx_time
= now
- t
->timestamp
;
403 perf_cgroup_defer_enabled(struct perf_event
*event
)
406 * when the current task's perf cgroup does not match
407 * the event's, we need to remember to call the
408 * perf_mark_enable() function the first time a task with
409 * a matching perf cgroup is scheduled in.
411 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
412 event
->cgrp_defer_enabled
= 1;
416 perf_cgroup_mark_enabled(struct perf_event
*event
,
417 struct perf_event_context
*ctx
)
419 struct perf_event
*sub
;
420 u64 tstamp
= perf_event_time(event
);
422 if (!event
->cgrp_defer_enabled
)
425 event
->cgrp_defer_enabled
= 0;
427 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
428 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
429 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
430 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
431 sub
->cgrp_defer_enabled
= 0;
435 #else /* !CONFIG_CGROUP_PERF */
438 perf_cgroup_match(struct perf_event
*event
)
443 static inline void perf_detach_cgroup(struct perf_event
*event
)
446 static inline int is_cgroup_event(struct perf_event
*event
)
451 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
456 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
460 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
464 static inline void perf_cgroup_sched_out(struct task_struct
*task
)
468 static inline void perf_cgroup_sched_in(struct task_struct
*task
)
472 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
473 struct perf_event_attr
*attr
,
474 struct perf_event
*group_leader
)
480 perf_cgroup_set_timestamp(struct task_struct
*task
, u64 now
)
485 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
490 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
494 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
500 perf_cgroup_defer_enabled(struct perf_event
*event
)
505 perf_cgroup_mark_enabled(struct perf_event
*event
,
506 struct perf_event_context
*ctx
)
511 void perf_pmu_disable(struct pmu
*pmu
)
513 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
515 pmu
->pmu_disable(pmu
);
518 void perf_pmu_enable(struct pmu
*pmu
)
520 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
522 pmu
->pmu_enable(pmu
);
525 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
528 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
529 * because they're strictly cpu affine and rotate_start is called with IRQs
530 * disabled, while rotate_context is called from IRQ context.
532 static void perf_pmu_rotate_start(struct pmu
*pmu
)
534 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
535 struct list_head
*head
= &__get_cpu_var(rotation_list
);
537 WARN_ON(!irqs_disabled());
539 if (list_empty(&cpuctx
->rotation_list
))
540 list_add(&cpuctx
->rotation_list
, head
);
543 static void get_ctx(struct perf_event_context
*ctx
)
545 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
548 static void free_ctx(struct rcu_head
*head
)
550 struct perf_event_context
*ctx
;
552 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
556 static void put_ctx(struct perf_event_context
*ctx
)
558 if (atomic_dec_and_test(&ctx
->refcount
)) {
560 put_ctx(ctx
->parent_ctx
);
562 put_task_struct(ctx
->task
);
563 call_rcu(&ctx
->rcu_head
, free_ctx
);
567 static void unclone_ctx(struct perf_event_context
*ctx
)
569 if (ctx
->parent_ctx
) {
570 put_ctx(ctx
->parent_ctx
);
571 ctx
->parent_ctx
= NULL
;
575 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
578 * only top level events have the pid namespace they were created in
581 event
= event
->parent
;
583 return task_tgid_nr_ns(p
, event
->ns
);
586 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
589 * only top level events have the pid namespace they were created in
592 event
= event
->parent
;
594 return task_pid_nr_ns(p
, event
->ns
);
598 * If we inherit events we want to return the parent event id
601 static u64
primary_event_id(struct perf_event
*event
)
606 id
= event
->parent
->id
;
612 * Get the perf_event_context for a task and lock it.
613 * This has to cope with with the fact that until it is locked,
614 * the context could get moved to another task.
616 static struct perf_event_context
*
617 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
619 struct perf_event_context
*ctx
;
623 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
626 * If this context is a clone of another, it might
627 * get swapped for another underneath us by
628 * perf_event_task_sched_out, though the
629 * rcu_read_lock() protects us from any context
630 * getting freed. Lock the context and check if it
631 * got swapped before we could get the lock, and retry
632 * if so. If we locked the right context, then it
633 * can't get swapped on us any more.
635 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
636 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
637 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
641 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
642 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
651 * Get the context for a task and increment its pin_count so it
652 * can't get swapped to another task. This also increments its
653 * reference count so that the context can't get freed.
655 static struct perf_event_context
*
656 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
658 struct perf_event_context
*ctx
;
661 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
664 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
669 static void perf_unpin_context(struct perf_event_context
*ctx
)
673 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
675 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
679 * Update the record of the current time in a context.
681 static void update_context_time(struct perf_event_context
*ctx
)
683 u64 now
= perf_clock();
685 ctx
->time
+= now
- ctx
->timestamp
;
686 ctx
->timestamp
= now
;
689 static u64
perf_event_time(struct perf_event
*event
)
691 struct perf_event_context
*ctx
= event
->ctx
;
693 if (is_cgroup_event(event
))
694 return perf_cgroup_event_time(event
);
696 return ctx
? ctx
->time
: 0;
700 * Update the total_time_enabled and total_time_running fields for a event.
702 static void update_event_times(struct perf_event
*event
)
704 struct perf_event_context
*ctx
= event
->ctx
;
707 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
708 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
711 * in cgroup mode, time_enabled represents
712 * the time the event was enabled AND active
713 * tasks were in the monitored cgroup. This is
714 * independent of the activity of the context as
715 * there may be a mix of cgroup and non-cgroup events.
717 * That is why we treat cgroup events differently
720 if (is_cgroup_event(event
))
721 run_end
= perf_event_time(event
);
722 else if (ctx
->is_active
)
725 run_end
= event
->tstamp_stopped
;
727 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
729 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
730 run_end
= event
->tstamp_stopped
;
732 run_end
= perf_event_time(event
);
734 event
->total_time_running
= run_end
- event
->tstamp_running
;
739 * Update total_time_enabled and total_time_running for all events in a group.
741 static void update_group_times(struct perf_event
*leader
)
743 struct perf_event
*event
;
745 update_event_times(leader
);
746 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
747 update_event_times(event
);
750 static struct list_head
*
751 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
753 if (event
->attr
.pinned
)
754 return &ctx
->pinned_groups
;
756 return &ctx
->flexible_groups
;
760 * Add a event from the lists for its context.
761 * Must be called with ctx->mutex and ctx->lock held.
764 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
766 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
767 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
770 * If we're a stand alone event or group leader, we go to the context
771 * list, group events are kept attached to the group so that
772 * perf_group_detach can, at all times, locate all siblings.
774 if (event
->group_leader
== event
) {
775 struct list_head
*list
;
777 if (is_software_event(event
))
778 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
780 list
= ctx_group_list(event
, ctx
);
781 list_add_tail(&event
->group_entry
, list
);
784 if (is_cgroup_event(event
)) {
788 * - that has cgroup constraint on event->cpu
789 * - that may need work on context switch
791 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
792 jump_label_inc(&perf_sched_events
);
795 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
797 perf_pmu_rotate_start(ctx
->pmu
);
799 if (event
->attr
.inherit_stat
)
804 * Called at perf_event creation and when events are attached/detached from a
807 static void perf_event__read_size(struct perf_event
*event
)
809 int entry
= sizeof(u64
); /* value */
813 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
816 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
819 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
820 entry
+= sizeof(u64
);
822 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
823 nr
+= event
->group_leader
->nr_siblings
;
828 event
->read_size
= size
;
831 static void perf_event__header_size(struct perf_event
*event
)
833 struct perf_sample_data
*data
;
834 u64 sample_type
= event
->attr
.sample_type
;
837 perf_event__read_size(event
);
839 if (sample_type
& PERF_SAMPLE_IP
)
840 size
+= sizeof(data
->ip
);
842 if (sample_type
& PERF_SAMPLE_ADDR
)
843 size
+= sizeof(data
->addr
);
845 if (sample_type
& PERF_SAMPLE_PERIOD
)
846 size
+= sizeof(data
->period
);
848 if (sample_type
& PERF_SAMPLE_READ
)
849 size
+= event
->read_size
;
851 event
->header_size
= size
;
854 static void perf_event__id_header_size(struct perf_event
*event
)
856 struct perf_sample_data
*data
;
857 u64 sample_type
= event
->attr
.sample_type
;
860 if (sample_type
& PERF_SAMPLE_TID
)
861 size
+= sizeof(data
->tid_entry
);
863 if (sample_type
& PERF_SAMPLE_TIME
)
864 size
+= sizeof(data
->time
);
866 if (sample_type
& PERF_SAMPLE_ID
)
867 size
+= sizeof(data
->id
);
869 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
870 size
+= sizeof(data
->stream_id
);
872 if (sample_type
& PERF_SAMPLE_CPU
)
873 size
+= sizeof(data
->cpu_entry
);
875 event
->id_header_size
= size
;
878 static void perf_group_attach(struct perf_event
*event
)
880 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
883 * We can have double attach due to group movement in perf_event_open.
885 if (event
->attach_state
& PERF_ATTACH_GROUP
)
888 event
->attach_state
|= PERF_ATTACH_GROUP
;
890 if (group_leader
== event
)
893 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
894 !is_software_event(event
))
895 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
897 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
898 group_leader
->nr_siblings
++;
900 perf_event__header_size(group_leader
);
902 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
903 perf_event__header_size(pos
);
907 * Remove a event from the lists for its context.
908 * Must be called with ctx->mutex and ctx->lock held.
911 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
914 * We can have double detach due to exit/hot-unplug + close.
916 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
919 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
921 if (is_cgroup_event(event
)) {
923 atomic_dec(&per_cpu(perf_cgroup_events
, event
->cpu
));
924 jump_label_dec(&perf_sched_events
);
928 if (event
->attr
.inherit_stat
)
931 list_del_rcu(&event
->event_entry
);
933 if (event
->group_leader
== event
)
934 list_del_init(&event
->group_entry
);
936 update_group_times(event
);
939 * If event was in error state, then keep it
940 * that way, otherwise bogus counts will be
941 * returned on read(). The only way to get out
942 * of error state is by explicit re-enabling
945 if (event
->state
> PERF_EVENT_STATE_OFF
)
946 event
->state
= PERF_EVENT_STATE_OFF
;
949 static void perf_group_detach(struct perf_event
*event
)
951 struct perf_event
*sibling
, *tmp
;
952 struct list_head
*list
= NULL
;
955 * We can have double detach due to exit/hot-unplug + close.
957 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
960 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
963 * If this is a sibling, remove it from its group.
965 if (event
->group_leader
!= event
) {
966 list_del_init(&event
->group_entry
);
967 event
->group_leader
->nr_siblings
--;
971 if (!list_empty(&event
->group_entry
))
972 list
= &event
->group_entry
;
975 * If this was a group event with sibling events then
976 * upgrade the siblings to singleton events by adding them
977 * to whatever list we are on.
979 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
981 list_move_tail(&sibling
->group_entry
, list
);
982 sibling
->group_leader
= sibling
;
984 /* Inherit group flags from the previous leader */
985 sibling
->group_flags
= event
->group_flags
;
989 perf_event__header_size(event
->group_leader
);
991 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
992 perf_event__header_size(tmp
);
996 event_filter_match(struct perf_event
*event
)
998 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
999 && perf_cgroup_match(event
);
1003 event_sched_out(struct perf_event
*event
,
1004 struct perf_cpu_context
*cpuctx
,
1005 struct perf_event_context
*ctx
)
1007 u64 tstamp
= perf_event_time(event
);
1010 * An event which could not be activated because of
1011 * filter mismatch still needs to have its timings
1012 * maintained, otherwise bogus information is return
1013 * via read() for time_enabled, time_running:
1015 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1016 && !event_filter_match(event
)) {
1017 delta
= tstamp
- event
->tstamp_stopped
;
1018 event
->tstamp_running
+= delta
;
1019 event
->tstamp_stopped
= tstamp
;
1022 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1025 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1026 if (event
->pending_disable
) {
1027 event
->pending_disable
= 0;
1028 event
->state
= PERF_EVENT_STATE_OFF
;
1030 event
->tstamp_stopped
= tstamp
;
1031 event
->pmu
->del(event
, 0);
1034 if (!is_software_event(event
))
1035 cpuctx
->active_oncpu
--;
1037 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1038 cpuctx
->exclusive
= 0;
1042 group_sched_out(struct perf_event
*group_event
,
1043 struct perf_cpu_context
*cpuctx
,
1044 struct perf_event_context
*ctx
)
1046 struct perf_event
*event
;
1047 int state
= group_event
->state
;
1049 event_sched_out(group_event
, cpuctx
, ctx
);
1052 * Schedule out siblings (if any):
1054 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1055 event_sched_out(event
, cpuctx
, ctx
);
1057 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1058 cpuctx
->exclusive
= 0;
1062 * Cross CPU call to remove a performance event
1064 * We disable the event on the hardware level first. After that we
1065 * remove it from the context list.
1067 static int __perf_remove_from_context(void *info
)
1069 struct perf_event
*event
= info
;
1070 struct perf_event_context
*ctx
= event
->ctx
;
1071 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1073 raw_spin_lock(&ctx
->lock
);
1074 event_sched_out(event
, cpuctx
, ctx
);
1075 list_del_event(event
, ctx
);
1076 raw_spin_unlock(&ctx
->lock
);
1083 * Remove the event from a task's (or a CPU's) list of events.
1085 * CPU events are removed with a smp call. For task events we only
1086 * call when the task is on a CPU.
1088 * If event->ctx is a cloned context, callers must make sure that
1089 * every task struct that event->ctx->task could possibly point to
1090 * remains valid. This is OK when called from perf_release since
1091 * that only calls us on the top-level context, which can't be a clone.
1092 * When called from perf_event_exit_task, it's OK because the
1093 * context has been detached from its task.
1095 static void perf_remove_from_context(struct perf_event
*event
)
1097 struct perf_event_context
*ctx
= event
->ctx
;
1098 struct task_struct
*task
= ctx
->task
;
1100 lockdep_assert_held(&ctx
->mutex
);
1104 * Per cpu events are removed via an smp call and
1105 * the removal is always successful.
1107 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1112 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1115 raw_spin_lock_irq(&ctx
->lock
);
1117 * If we failed to find a running task, but find the context active now
1118 * that we've acquired the ctx->lock, retry.
1120 if (ctx
->is_active
) {
1121 raw_spin_unlock_irq(&ctx
->lock
);
1126 * Since the task isn't running, its safe to remove the event, us
1127 * holding the ctx->lock ensures the task won't get scheduled in.
1129 list_del_event(event
, ctx
);
1130 raw_spin_unlock_irq(&ctx
->lock
);
1134 * Cross CPU call to disable a performance event
1136 static int __perf_event_disable(void *info
)
1138 struct perf_event
*event
= info
;
1139 struct perf_event_context
*ctx
= event
->ctx
;
1140 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1143 * If this is a per-task event, need to check whether this
1144 * event's task is the current task on this cpu.
1146 * Can trigger due to concurrent perf_event_context_sched_out()
1147 * flipping contexts around.
1149 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1152 raw_spin_lock(&ctx
->lock
);
1155 * If the event is on, turn it off.
1156 * If it is in error state, leave it in error state.
1158 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1159 update_context_time(ctx
);
1160 update_cgrp_time_from_event(event
);
1161 update_group_times(event
);
1162 if (event
== event
->group_leader
)
1163 group_sched_out(event
, cpuctx
, ctx
);
1165 event_sched_out(event
, cpuctx
, ctx
);
1166 event
->state
= PERF_EVENT_STATE_OFF
;
1169 raw_spin_unlock(&ctx
->lock
);
1177 * If event->ctx is a cloned context, callers must make sure that
1178 * every task struct that event->ctx->task could possibly point to
1179 * remains valid. This condition is satisifed when called through
1180 * perf_event_for_each_child or perf_event_for_each because they
1181 * hold the top-level event's child_mutex, so any descendant that
1182 * goes to exit will block in sync_child_event.
1183 * When called from perf_pending_event it's OK because event->ctx
1184 * is the current context on this CPU and preemption is disabled,
1185 * hence we can't get into perf_event_task_sched_out for this context.
1187 void perf_event_disable(struct perf_event
*event
)
1189 struct perf_event_context
*ctx
= event
->ctx
;
1190 struct task_struct
*task
= ctx
->task
;
1194 * Disable the event on the cpu that it's on
1196 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1201 if (!task_function_call(task
, __perf_event_disable
, event
))
1204 raw_spin_lock_irq(&ctx
->lock
);
1206 * If the event is still active, we need to retry the cross-call.
1208 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1209 raw_spin_unlock_irq(&ctx
->lock
);
1211 * Reload the task pointer, it might have been changed by
1212 * a concurrent perf_event_context_sched_out().
1219 * Since we have the lock this context can't be scheduled
1220 * in, so we can change the state safely.
1222 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1223 update_group_times(event
);
1224 event
->state
= PERF_EVENT_STATE_OFF
;
1226 raw_spin_unlock_irq(&ctx
->lock
);
1229 static void perf_set_shadow_time(struct perf_event
*event
,
1230 struct perf_event_context
*ctx
,
1234 * use the correct time source for the time snapshot
1236 * We could get by without this by leveraging the
1237 * fact that to get to this function, the caller
1238 * has most likely already called update_context_time()
1239 * and update_cgrp_time_xx() and thus both timestamp
1240 * are identical (or very close). Given that tstamp is,
1241 * already adjusted for cgroup, we could say that:
1242 * tstamp - ctx->timestamp
1244 * tstamp - cgrp->timestamp.
1246 * Then, in perf_output_read(), the calculation would
1247 * work with no changes because:
1248 * - event is guaranteed scheduled in
1249 * - no scheduled out in between
1250 * - thus the timestamp would be the same
1252 * But this is a bit hairy.
1254 * So instead, we have an explicit cgroup call to remain
1255 * within the time time source all along. We believe it
1256 * is cleaner and simpler to understand.
1258 if (is_cgroup_event(event
))
1259 perf_cgroup_set_shadow_time(event
, tstamp
);
1261 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1264 #define MAX_INTERRUPTS (~0ULL)
1266 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1269 event_sched_in(struct perf_event
*event
,
1270 struct perf_cpu_context
*cpuctx
,
1271 struct perf_event_context
*ctx
)
1273 u64 tstamp
= perf_event_time(event
);
1275 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1278 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1279 event
->oncpu
= smp_processor_id();
1282 * Unthrottle events, since we scheduled we might have missed several
1283 * ticks already, also for a heavily scheduling task there is little
1284 * guarantee it'll get a tick in a timely manner.
1286 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1287 perf_log_throttle(event
, 1);
1288 event
->hw
.interrupts
= 0;
1292 * The new state must be visible before we turn it on in the hardware:
1296 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1297 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1302 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1304 perf_set_shadow_time(event
, ctx
, tstamp
);
1306 if (!is_software_event(event
))
1307 cpuctx
->active_oncpu
++;
1310 if (event
->attr
.exclusive
)
1311 cpuctx
->exclusive
= 1;
1317 group_sched_in(struct perf_event
*group_event
,
1318 struct perf_cpu_context
*cpuctx
,
1319 struct perf_event_context
*ctx
)
1321 struct perf_event
*event
, *partial_group
= NULL
;
1322 struct pmu
*pmu
= group_event
->pmu
;
1323 u64 now
= ctx
->time
;
1324 bool simulate
= false;
1326 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1329 pmu
->start_txn(pmu
);
1331 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1332 pmu
->cancel_txn(pmu
);
1337 * Schedule in siblings as one group (if any):
1339 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1340 if (event_sched_in(event
, cpuctx
, ctx
)) {
1341 partial_group
= event
;
1346 if (!pmu
->commit_txn(pmu
))
1351 * Groups can be scheduled in as one unit only, so undo any
1352 * partial group before returning:
1353 * The events up to the failed event are scheduled out normally,
1354 * tstamp_stopped will be updated.
1356 * The failed events and the remaining siblings need to have
1357 * their timings updated as if they had gone thru event_sched_in()
1358 * and event_sched_out(). This is required to get consistent timings
1359 * across the group. This also takes care of the case where the group
1360 * could never be scheduled by ensuring tstamp_stopped is set to mark
1361 * the time the event was actually stopped, such that time delta
1362 * calculation in update_event_times() is correct.
1364 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1365 if (event
== partial_group
)
1369 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1370 event
->tstamp_stopped
= now
;
1372 event_sched_out(event
, cpuctx
, ctx
);
1375 event_sched_out(group_event
, cpuctx
, ctx
);
1377 pmu
->cancel_txn(pmu
);
1383 * Work out whether we can put this event group on the CPU now.
1385 static int group_can_go_on(struct perf_event
*event
,
1386 struct perf_cpu_context
*cpuctx
,
1390 * Groups consisting entirely of software events can always go on.
1392 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1395 * If an exclusive group is already on, no other hardware
1398 if (cpuctx
->exclusive
)
1401 * If this group is exclusive and there are already
1402 * events on the CPU, it can't go on.
1404 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1407 * Otherwise, try to add it if all previous groups were able
1413 static void add_event_to_ctx(struct perf_event
*event
,
1414 struct perf_event_context
*ctx
)
1416 u64 tstamp
= perf_event_time(event
);
1418 list_add_event(event
, ctx
);
1419 perf_group_attach(event
);
1420 event
->tstamp_enabled
= tstamp
;
1421 event
->tstamp_running
= tstamp
;
1422 event
->tstamp_stopped
= tstamp
;
1425 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
1426 struct task_struct
*tsk
);
1429 * Cross CPU call to install and enable a performance event
1431 * Must be called with ctx->mutex held
1433 static int __perf_install_in_context(void *info
)
1435 struct perf_event
*event
= info
;
1436 struct perf_event_context
*ctx
= event
->ctx
;
1437 struct perf_event
*leader
= event
->group_leader
;
1438 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1442 * In case we're installing a new context to an already running task,
1443 * could also happen before perf_event_task_sched_in() on architectures
1444 * which do context switches with IRQs enabled.
1446 if (ctx
->task
&& !cpuctx
->task_ctx
)
1447 perf_event_context_sched_in(ctx
, ctx
->task
);
1449 raw_spin_lock(&ctx
->lock
);
1451 update_context_time(ctx
);
1453 * update cgrp time only if current cgrp
1454 * matches event->cgrp. Must be done before
1455 * calling add_event_to_ctx()
1457 update_cgrp_time_from_event(event
);
1459 add_event_to_ctx(event
, ctx
);
1461 if (!event_filter_match(event
))
1465 * Don't put the event on if it is disabled or if
1466 * it is in a group and the group isn't on.
1468 if (event
->state
!= PERF_EVENT_STATE_INACTIVE
||
1469 (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
))
1473 * An exclusive event can't go on if there are already active
1474 * hardware events, and no hardware event can go on if there
1475 * is already an exclusive event on.
1477 if (!group_can_go_on(event
, cpuctx
, 1))
1480 err
= event_sched_in(event
, cpuctx
, ctx
);
1484 * This event couldn't go on. If it is in a group
1485 * then we have to pull the whole group off.
1486 * If the event group is pinned then put it in error state.
1488 if (leader
!= event
)
1489 group_sched_out(leader
, cpuctx
, ctx
);
1490 if (leader
->attr
.pinned
) {
1491 update_group_times(leader
);
1492 leader
->state
= PERF_EVENT_STATE_ERROR
;
1497 raw_spin_unlock(&ctx
->lock
);
1503 * Attach a performance event to a context
1505 * First we add the event to the list with the hardware enable bit
1506 * in event->hw_config cleared.
1508 * If the event is attached to a task which is on a CPU we use a smp
1509 * call to enable it in the task context. The task might have been
1510 * scheduled away, but we check this in the smp call again.
1513 perf_install_in_context(struct perf_event_context
*ctx
,
1514 struct perf_event
*event
,
1517 struct task_struct
*task
= ctx
->task
;
1519 lockdep_assert_held(&ctx
->mutex
);
1525 * Per cpu events are installed via an smp call and
1526 * the install is always successful.
1528 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1533 if (!task_function_call(task
, __perf_install_in_context
, event
))
1536 raw_spin_lock_irq(&ctx
->lock
);
1538 * If we failed to find a running task, but find the context active now
1539 * that we've acquired the ctx->lock, retry.
1541 if (ctx
->is_active
) {
1542 raw_spin_unlock_irq(&ctx
->lock
);
1547 * Since the task isn't running, its safe to add the event, us holding
1548 * the ctx->lock ensures the task won't get scheduled in.
1550 add_event_to_ctx(event
, ctx
);
1551 raw_spin_unlock_irq(&ctx
->lock
);
1555 * Put a event into inactive state and update time fields.
1556 * Enabling the leader of a group effectively enables all
1557 * the group members that aren't explicitly disabled, so we
1558 * have to update their ->tstamp_enabled also.
1559 * Note: this works for group members as well as group leaders
1560 * since the non-leader members' sibling_lists will be empty.
1562 static void __perf_event_mark_enabled(struct perf_event
*event
,
1563 struct perf_event_context
*ctx
)
1565 struct perf_event
*sub
;
1566 u64 tstamp
= perf_event_time(event
);
1568 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1569 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1570 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1571 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1572 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1577 * Cross CPU call to enable a performance event
1579 static int __perf_event_enable(void *info
)
1581 struct perf_event
*event
= info
;
1582 struct perf_event_context
*ctx
= event
->ctx
;
1583 struct perf_event
*leader
= event
->group_leader
;
1584 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1587 if (WARN_ON_ONCE(!ctx
->is_active
))
1590 raw_spin_lock(&ctx
->lock
);
1591 update_context_time(ctx
);
1593 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1597 * set current task's cgroup time reference point
1599 perf_cgroup_set_timestamp(current
, perf_clock());
1601 __perf_event_mark_enabled(event
, ctx
);
1603 if (!event_filter_match(event
)) {
1604 if (is_cgroup_event(event
))
1605 perf_cgroup_defer_enabled(event
);
1610 * If the event is in a group and isn't the group leader,
1611 * then don't put it on unless the group is on.
1613 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1616 if (!group_can_go_on(event
, cpuctx
, 1)) {
1619 if (event
== leader
)
1620 err
= group_sched_in(event
, cpuctx
, ctx
);
1622 err
= event_sched_in(event
, cpuctx
, ctx
);
1627 * If this event can't go on and it's part of a
1628 * group, then the whole group has to come off.
1630 if (leader
!= event
)
1631 group_sched_out(leader
, cpuctx
, ctx
);
1632 if (leader
->attr
.pinned
) {
1633 update_group_times(leader
);
1634 leader
->state
= PERF_EVENT_STATE_ERROR
;
1639 raw_spin_unlock(&ctx
->lock
);
1647 * If event->ctx is a cloned context, callers must make sure that
1648 * every task struct that event->ctx->task could possibly point to
1649 * remains valid. This condition is satisfied when called through
1650 * perf_event_for_each_child or perf_event_for_each as described
1651 * for perf_event_disable.
1653 void perf_event_enable(struct perf_event
*event
)
1655 struct perf_event_context
*ctx
= event
->ctx
;
1656 struct task_struct
*task
= ctx
->task
;
1660 * Enable the event on the cpu that it's on
1662 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
1666 raw_spin_lock_irq(&ctx
->lock
);
1667 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1671 * If the event is in error state, clear that first.
1672 * That way, if we see the event in error state below, we
1673 * know that it has gone back into error state, as distinct
1674 * from the task having been scheduled away before the
1675 * cross-call arrived.
1677 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1678 event
->state
= PERF_EVENT_STATE_OFF
;
1681 if (!ctx
->is_active
) {
1682 __perf_event_mark_enabled(event
, ctx
);
1686 raw_spin_unlock_irq(&ctx
->lock
);
1688 if (!task_function_call(task
, __perf_event_enable
, event
))
1691 raw_spin_lock_irq(&ctx
->lock
);
1694 * If the context is active and the event is still off,
1695 * we need to retry the cross-call.
1697 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
1699 * task could have been flipped by a concurrent
1700 * perf_event_context_sched_out()
1707 raw_spin_unlock_irq(&ctx
->lock
);
1710 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1713 * not supported on inherited events
1715 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1718 atomic_add(refresh
, &event
->event_limit
);
1719 perf_event_enable(event
);
1724 static void ctx_sched_out(struct perf_event_context
*ctx
,
1725 struct perf_cpu_context
*cpuctx
,
1726 enum event_type_t event_type
)
1728 struct perf_event
*event
;
1730 raw_spin_lock(&ctx
->lock
);
1731 perf_pmu_disable(ctx
->pmu
);
1733 if (likely(!ctx
->nr_events
))
1735 update_context_time(ctx
);
1736 update_cgrp_time_from_cpuctx(cpuctx
);
1738 if (!ctx
->nr_active
)
1741 if (event_type
& EVENT_PINNED
) {
1742 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1743 group_sched_out(event
, cpuctx
, ctx
);
1746 if (event_type
& EVENT_FLEXIBLE
) {
1747 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1748 group_sched_out(event
, cpuctx
, ctx
);
1751 perf_pmu_enable(ctx
->pmu
);
1752 raw_spin_unlock(&ctx
->lock
);
1756 * Test whether two contexts are equivalent, i.e. whether they
1757 * have both been cloned from the same version of the same context
1758 * and they both have the same number of enabled events.
1759 * If the number of enabled events is the same, then the set
1760 * of enabled events should be the same, because these are both
1761 * inherited contexts, therefore we can't access individual events
1762 * in them directly with an fd; we can only enable/disable all
1763 * events via prctl, or enable/disable all events in a family
1764 * via ioctl, which will have the same effect on both contexts.
1766 static int context_equiv(struct perf_event_context
*ctx1
,
1767 struct perf_event_context
*ctx2
)
1769 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1770 && ctx1
->parent_gen
== ctx2
->parent_gen
1771 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1774 static void __perf_event_sync_stat(struct perf_event
*event
,
1775 struct perf_event
*next_event
)
1779 if (!event
->attr
.inherit_stat
)
1783 * Update the event value, we cannot use perf_event_read()
1784 * because we're in the middle of a context switch and have IRQs
1785 * disabled, which upsets smp_call_function_single(), however
1786 * we know the event must be on the current CPU, therefore we
1787 * don't need to use it.
1789 switch (event
->state
) {
1790 case PERF_EVENT_STATE_ACTIVE
:
1791 event
->pmu
->read(event
);
1794 case PERF_EVENT_STATE_INACTIVE
:
1795 update_event_times(event
);
1803 * In order to keep per-task stats reliable we need to flip the event
1804 * values when we flip the contexts.
1806 value
= local64_read(&next_event
->count
);
1807 value
= local64_xchg(&event
->count
, value
);
1808 local64_set(&next_event
->count
, value
);
1810 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1811 swap(event
->total_time_running
, next_event
->total_time_running
);
1814 * Since we swizzled the values, update the user visible data too.
1816 perf_event_update_userpage(event
);
1817 perf_event_update_userpage(next_event
);
1820 #define list_next_entry(pos, member) \
1821 list_entry(pos->member.next, typeof(*pos), member)
1823 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1824 struct perf_event_context
*next_ctx
)
1826 struct perf_event
*event
, *next_event
;
1831 update_context_time(ctx
);
1833 event
= list_first_entry(&ctx
->event_list
,
1834 struct perf_event
, event_entry
);
1836 next_event
= list_first_entry(&next_ctx
->event_list
,
1837 struct perf_event
, event_entry
);
1839 while (&event
->event_entry
!= &ctx
->event_list
&&
1840 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1842 __perf_event_sync_stat(event
, next_event
);
1844 event
= list_next_entry(event
, event_entry
);
1845 next_event
= list_next_entry(next_event
, event_entry
);
1849 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
1850 struct task_struct
*next
)
1852 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
1853 struct perf_event_context
*next_ctx
;
1854 struct perf_event_context
*parent
;
1855 struct perf_cpu_context
*cpuctx
;
1861 cpuctx
= __get_cpu_context(ctx
);
1862 if (!cpuctx
->task_ctx
)
1866 parent
= rcu_dereference(ctx
->parent_ctx
);
1867 next_ctx
= next
->perf_event_ctxp
[ctxn
];
1868 if (parent
&& next_ctx
&&
1869 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1871 * Looks like the two contexts are clones, so we might be
1872 * able to optimize the context switch. We lock both
1873 * contexts and check that they are clones under the
1874 * lock (including re-checking that neither has been
1875 * uncloned in the meantime). It doesn't matter which
1876 * order we take the locks because no other cpu could
1877 * be trying to lock both of these tasks.
1879 raw_spin_lock(&ctx
->lock
);
1880 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1881 if (context_equiv(ctx
, next_ctx
)) {
1883 * XXX do we need a memory barrier of sorts
1884 * wrt to rcu_dereference() of perf_event_ctxp
1886 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
1887 next
->perf_event_ctxp
[ctxn
] = ctx
;
1889 next_ctx
->task
= task
;
1892 perf_event_sync_stat(ctx
, next_ctx
);
1894 raw_spin_unlock(&next_ctx
->lock
);
1895 raw_spin_unlock(&ctx
->lock
);
1900 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1901 cpuctx
->task_ctx
= NULL
;
1905 #define for_each_task_context_nr(ctxn) \
1906 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
1909 * Called from scheduler to remove the events of the current task,
1910 * with interrupts disabled.
1912 * We stop each event and update the event value in event->count.
1914 * This does not protect us against NMI, but disable()
1915 * sets the disabled bit in the control field of event _before_
1916 * accessing the event control register. If a NMI hits, then it will
1917 * not restart the event.
1919 void __perf_event_task_sched_out(struct task_struct
*task
,
1920 struct task_struct
*next
)
1924 for_each_task_context_nr(ctxn
)
1925 perf_event_context_sched_out(task
, ctxn
, next
);
1928 * if cgroup events exist on this CPU, then we need
1929 * to check if we have to switch out PMU state.
1930 * cgroup event are system-wide mode only
1932 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
1933 perf_cgroup_sched_out(task
);
1936 static void task_ctx_sched_out(struct perf_event_context
*ctx
,
1937 enum event_type_t event_type
)
1939 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1941 if (!cpuctx
->task_ctx
)
1944 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1947 ctx_sched_out(ctx
, cpuctx
, event_type
);
1948 cpuctx
->task_ctx
= NULL
;
1952 * Called with IRQs disabled
1954 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1955 enum event_type_t event_type
)
1957 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
1961 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
1962 struct perf_cpu_context
*cpuctx
)
1964 struct perf_event
*event
;
1966 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
1967 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1969 if (!event_filter_match(event
))
1972 /* may need to reset tstamp_enabled */
1973 if (is_cgroup_event(event
))
1974 perf_cgroup_mark_enabled(event
, ctx
);
1976 if (group_can_go_on(event
, cpuctx
, 1))
1977 group_sched_in(event
, cpuctx
, ctx
);
1980 * If this pinned group hasn't been scheduled,
1981 * put it in error state.
1983 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1984 update_group_times(event
);
1985 event
->state
= PERF_EVENT_STATE_ERROR
;
1991 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
1992 struct perf_cpu_context
*cpuctx
)
1994 struct perf_event
*event
;
1997 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
1998 /* Ignore events in OFF or ERROR state */
1999 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2002 * Listen to the 'cpu' scheduling filter constraint
2005 if (!event_filter_match(event
))
2008 /* may need to reset tstamp_enabled */
2009 if (is_cgroup_event(event
))
2010 perf_cgroup_mark_enabled(event
, ctx
);
2012 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2013 if (group_sched_in(event
, cpuctx
, ctx
))
2020 ctx_sched_in(struct perf_event_context
*ctx
,
2021 struct perf_cpu_context
*cpuctx
,
2022 enum event_type_t event_type
,
2023 struct task_struct
*task
)
2027 raw_spin_lock(&ctx
->lock
);
2029 if (likely(!ctx
->nr_events
))
2033 ctx
->timestamp
= now
;
2034 perf_cgroup_set_timestamp(task
, now
);
2036 * First go through the list and put on any pinned groups
2037 * in order to give them the best chance of going on.
2039 if (event_type
& EVENT_PINNED
)
2040 ctx_pinned_sched_in(ctx
, cpuctx
);
2042 /* Then walk through the lower prio flexible groups */
2043 if (event_type
& EVENT_FLEXIBLE
)
2044 ctx_flexible_sched_in(ctx
, cpuctx
);
2047 raw_spin_unlock(&ctx
->lock
);
2050 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2051 enum event_type_t event_type
,
2052 struct task_struct
*task
)
2054 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2056 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2059 static void task_ctx_sched_in(struct perf_event_context
*ctx
,
2060 enum event_type_t event_type
)
2062 struct perf_cpu_context
*cpuctx
;
2064 cpuctx
= __get_cpu_context(ctx
);
2065 if (cpuctx
->task_ctx
== ctx
)
2068 ctx_sched_in(ctx
, cpuctx
, event_type
, NULL
);
2069 cpuctx
->task_ctx
= ctx
;
2072 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2073 struct task_struct
*task
)
2075 struct perf_cpu_context
*cpuctx
;
2077 cpuctx
= __get_cpu_context(ctx
);
2078 if (cpuctx
->task_ctx
== ctx
)
2081 perf_pmu_disable(ctx
->pmu
);
2083 * We want to keep the following priority order:
2084 * cpu pinned (that don't need to move), task pinned,
2085 * cpu flexible, task flexible.
2087 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2089 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2090 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2091 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2093 cpuctx
->task_ctx
= ctx
;
2096 * Since these rotations are per-cpu, we need to ensure the
2097 * cpu-context we got scheduled on is actually rotating.
2099 perf_pmu_rotate_start(ctx
->pmu
);
2100 perf_pmu_enable(ctx
->pmu
);
2104 * Called from scheduler to add the events of the current task
2105 * with interrupts disabled.
2107 * We restore the event value and then enable it.
2109 * This does not protect us against NMI, but enable()
2110 * sets the enabled bit in the control field of event _before_
2111 * accessing the event control register. If a NMI hits, then it will
2112 * keep the event running.
2114 void __perf_event_task_sched_in(struct task_struct
*task
)
2116 struct perf_event_context
*ctx
;
2119 for_each_task_context_nr(ctxn
) {
2120 ctx
= task
->perf_event_ctxp
[ctxn
];
2124 perf_event_context_sched_in(ctx
, task
);
2127 * if cgroup events exist on this CPU, then we need
2128 * to check if we have to switch in PMU state.
2129 * cgroup event are system-wide mode only
2131 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2132 perf_cgroup_sched_in(task
);
2135 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2137 u64 frequency
= event
->attr
.sample_freq
;
2138 u64 sec
= NSEC_PER_SEC
;
2139 u64 divisor
, dividend
;
2141 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2143 count_fls
= fls64(count
);
2144 nsec_fls
= fls64(nsec
);
2145 frequency_fls
= fls64(frequency
);
2149 * We got @count in @nsec, with a target of sample_freq HZ
2150 * the target period becomes:
2153 * period = -------------------
2154 * @nsec * sample_freq
2159 * Reduce accuracy by one bit such that @a and @b converge
2160 * to a similar magnitude.
2162 #define REDUCE_FLS(a, b) \
2164 if (a##_fls > b##_fls) { \
2174 * Reduce accuracy until either term fits in a u64, then proceed with
2175 * the other, so that finally we can do a u64/u64 division.
2177 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2178 REDUCE_FLS(nsec
, frequency
);
2179 REDUCE_FLS(sec
, count
);
2182 if (count_fls
+ sec_fls
> 64) {
2183 divisor
= nsec
* frequency
;
2185 while (count_fls
+ sec_fls
> 64) {
2186 REDUCE_FLS(count
, sec
);
2190 dividend
= count
* sec
;
2192 dividend
= count
* sec
;
2194 while (nsec_fls
+ frequency_fls
> 64) {
2195 REDUCE_FLS(nsec
, frequency
);
2199 divisor
= nsec
* frequency
;
2205 return div64_u64(dividend
, divisor
);
2208 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2210 struct hw_perf_event
*hwc
= &event
->hw
;
2211 s64 period
, sample_period
;
2214 period
= perf_calculate_period(event
, nsec
, count
);
2216 delta
= (s64
)(period
- hwc
->sample_period
);
2217 delta
= (delta
+ 7) / 8; /* low pass filter */
2219 sample_period
= hwc
->sample_period
+ delta
;
2224 hwc
->sample_period
= sample_period
;
2226 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2227 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2228 local64_set(&hwc
->period_left
, 0);
2229 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2233 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
, u64 period
)
2235 struct perf_event
*event
;
2236 struct hw_perf_event
*hwc
;
2237 u64 interrupts
, now
;
2240 raw_spin_lock(&ctx
->lock
);
2241 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2242 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2245 if (!event_filter_match(event
))
2250 interrupts
= hwc
->interrupts
;
2251 hwc
->interrupts
= 0;
2254 * unthrottle events on the tick
2256 if (interrupts
== MAX_INTERRUPTS
) {
2257 perf_log_throttle(event
, 1);
2258 event
->pmu
->start(event
, 0);
2261 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2264 event
->pmu
->read(event
);
2265 now
= local64_read(&event
->count
);
2266 delta
= now
- hwc
->freq_count_stamp
;
2267 hwc
->freq_count_stamp
= now
;
2270 perf_adjust_period(event
, period
, delta
);
2272 raw_spin_unlock(&ctx
->lock
);
2276 * Round-robin a context's events:
2278 static void rotate_ctx(struct perf_event_context
*ctx
)
2280 raw_spin_lock(&ctx
->lock
);
2283 * Rotate the first entry last of non-pinned groups. Rotation might be
2284 * disabled by the inheritance code.
2286 if (!ctx
->rotate_disable
)
2287 list_rotate_left(&ctx
->flexible_groups
);
2289 raw_spin_unlock(&ctx
->lock
);
2293 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2294 * because they're strictly cpu affine and rotate_start is called with IRQs
2295 * disabled, while rotate_context is called from IRQ context.
2297 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2299 u64 interval
= (u64
)cpuctx
->jiffies_interval
* TICK_NSEC
;
2300 struct perf_event_context
*ctx
= NULL
;
2301 int rotate
= 0, remove
= 1;
2303 if (cpuctx
->ctx
.nr_events
) {
2305 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2309 ctx
= cpuctx
->task_ctx
;
2310 if (ctx
&& ctx
->nr_events
) {
2312 if (ctx
->nr_events
!= ctx
->nr_active
)
2316 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2317 perf_ctx_adjust_freq(&cpuctx
->ctx
, interval
);
2319 perf_ctx_adjust_freq(ctx
, interval
);
2324 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2326 task_ctx_sched_out(ctx
, EVENT_FLEXIBLE
);
2328 rotate_ctx(&cpuctx
->ctx
);
2332 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, current
);
2334 task_ctx_sched_in(ctx
, EVENT_FLEXIBLE
);
2338 list_del_init(&cpuctx
->rotation_list
);
2340 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2343 void perf_event_task_tick(void)
2345 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2346 struct perf_cpu_context
*cpuctx
, *tmp
;
2348 WARN_ON(!irqs_disabled());
2350 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2351 if (cpuctx
->jiffies_interval
== 1 ||
2352 !(jiffies
% cpuctx
->jiffies_interval
))
2353 perf_rotate_context(cpuctx
);
2357 static int event_enable_on_exec(struct perf_event
*event
,
2358 struct perf_event_context
*ctx
)
2360 if (!event
->attr
.enable_on_exec
)
2363 event
->attr
.enable_on_exec
= 0;
2364 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2367 __perf_event_mark_enabled(event
, ctx
);
2373 * Enable all of a task's events that have been marked enable-on-exec.
2374 * This expects task == current.
2376 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2378 struct perf_event
*event
;
2379 unsigned long flags
;
2383 local_irq_save(flags
);
2384 if (!ctx
|| !ctx
->nr_events
)
2387 task_ctx_sched_out(ctx
, EVENT_ALL
);
2389 raw_spin_lock(&ctx
->lock
);
2391 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2392 ret
= event_enable_on_exec(event
, ctx
);
2397 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2398 ret
= event_enable_on_exec(event
, ctx
);
2404 * Unclone this context if we enabled any event.
2409 raw_spin_unlock(&ctx
->lock
);
2411 perf_event_context_sched_in(ctx
, ctx
->task
);
2413 local_irq_restore(flags
);
2417 * Cross CPU call to read the hardware event
2419 static void __perf_event_read(void *info
)
2421 struct perf_event
*event
= info
;
2422 struct perf_event_context
*ctx
= event
->ctx
;
2423 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2426 * If this is a task context, we need to check whether it is
2427 * the current task context of this cpu. If not it has been
2428 * scheduled out before the smp call arrived. In that case
2429 * event->count would have been updated to a recent sample
2430 * when the event was scheduled out.
2432 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2435 raw_spin_lock(&ctx
->lock
);
2436 if (ctx
->is_active
) {
2437 update_context_time(ctx
);
2438 update_cgrp_time_from_event(event
);
2440 update_event_times(event
);
2441 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2442 event
->pmu
->read(event
);
2443 raw_spin_unlock(&ctx
->lock
);
2446 static inline u64
perf_event_count(struct perf_event
*event
)
2448 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2451 static u64
perf_event_read(struct perf_event
*event
)
2454 * If event is enabled and currently active on a CPU, update the
2455 * value in the event structure:
2457 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2458 smp_call_function_single(event
->oncpu
,
2459 __perf_event_read
, event
, 1);
2460 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2461 struct perf_event_context
*ctx
= event
->ctx
;
2462 unsigned long flags
;
2464 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2466 * may read while context is not active
2467 * (e.g., thread is blocked), in that case
2468 * we cannot update context time
2470 if (ctx
->is_active
) {
2471 update_context_time(ctx
);
2472 update_cgrp_time_from_event(event
);
2474 update_event_times(event
);
2475 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2478 return perf_event_count(event
);
2485 struct callchain_cpus_entries
{
2486 struct rcu_head rcu_head
;
2487 struct perf_callchain_entry
*cpu_entries
[0];
2490 static DEFINE_PER_CPU(int, callchain_recursion
[PERF_NR_CONTEXTS
]);
2491 static atomic_t nr_callchain_events
;
2492 static DEFINE_MUTEX(callchain_mutex
);
2493 struct callchain_cpus_entries
*callchain_cpus_entries
;
2496 __weak
void perf_callchain_kernel(struct perf_callchain_entry
*entry
,
2497 struct pt_regs
*regs
)
2501 __weak
void perf_callchain_user(struct perf_callchain_entry
*entry
,
2502 struct pt_regs
*regs
)
2506 static void release_callchain_buffers_rcu(struct rcu_head
*head
)
2508 struct callchain_cpus_entries
*entries
;
2511 entries
= container_of(head
, struct callchain_cpus_entries
, rcu_head
);
2513 for_each_possible_cpu(cpu
)
2514 kfree(entries
->cpu_entries
[cpu
]);
2519 static void release_callchain_buffers(void)
2521 struct callchain_cpus_entries
*entries
;
2523 entries
= callchain_cpus_entries
;
2524 rcu_assign_pointer(callchain_cpus_entries
, NULL
);
2525 call_rcu(&entries
->rcu_head
, release_callchain_buffers_rcu
);
2528 static int alloc_callchain_buffers(void)
2532 struct callchain_cpus_entries
*entries
;
2535 * We can't use the percpu allocation API for data that can be
2536 * accessed from NMI. Use a temporary manual per cpu allocation
2537 * until that gets sorted out.
2539 size
= offsetof(struct callchain_cpus_entries
, cpu_entries
[nr_cpu_ids
]);
2541 entries
= kzalloc(size
, GFP_KERNEL
);
2545 size
= sizeof(struct perf_callchain_entry
) * PERF_NR_CONTEXTS
;
2547 for_each_possible_cpu(cpu
) {
2548 entries
->cpu_entries
[cpu
] = kmalloc_node(size
, GFP_KERNEL
,
2550 if (!entries
->cpu_entries
[cpu
])
2554 rcu_assign_pointer(callchain_cpus_entries
, entries
);
2559 for_each_possible_cpu(cpu
)
2560 kfree(entries
->cpu_entries
[cpu
]);
2566 static int get_callchain_buffers(void)
2571 mutex_lock(&callchain_mutex
);
2573 count
= atomic_inc_return(&nr_callchain_events
);
2574 if (WARN_ON_ONCE(count
< 1)) {
2580 /* If the allocation failed, give up */
2581 if (!callchain_cpus_entries
)
2586 err
= alloc_callchain_buffers();
2588 release_callchain_buffers();
2590 mutex_unlock(&callchain_mutex
);
2595 static void put_callchain_buffers(void)
2597 if (atomic_dec_and_mutex_lock(&nr_callchain_events
, &callchain_mutex
)) {
2598 release_callchain_buffers();
2599 mutex_unlock(&callchain_mutex
);
2603 static int get_recursion_context(int *recursion
)
2611 else if (in_softirq())
2616 if (recursion
[rctx
])
2625 static inline void put_recursion_context(int *recursion
, int rctx
)
2631 static struct perf_callchain_entry
*get_callchain_entry(int *rctx
)
2634 struct callchain_cpus_entries
*entries
;
2636 *rctx
= get_recursion_context(__get_cpu_var(callchain_recursion
));
2640 entries
= rcu_dereference(callchain_cpus_entries
);
2644 cpu
= smp_processor_id();
2646 return &entries
->cpu_entries
[cpu
][*rctx
];
2650 put_callchain_entry(int rctx
)
2652 put_recursion_context(__get_cpu_var(callchain_recursion
), rctx
);
2655 static struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2658 struct perf_callchain_entry
*entry
;
2661 entry
= get_callchain_entry(&rctx
);
2670 if (!user_mode(regs
)) {
2671 perf_callchain_store(entry
, PERF_CONTEXT_KERNEL
);
2672 perf_callchain_kernel(entry
, regs
);
2674 regs
= task_pt_regs(current
);
2680 perf_callchain_store(entry
, PERF_CONTEXT_USER
);
2681 perf_callchain_user(entry
, regs
);
2685 put_callchain_entry(rctx
);
2691 * Initialize the perf_event context in a task_struct:
2693 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2695 raw_spin_lock_init(&ctx
->lock
);
2696 mutex_init(&ctx
->mutex
);
2697 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2698 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2699 INIT_LIST_HEAD(&ctx
->event_list
);
2700 atomic_set(&ctx
->refcount
, 1);
2703 static struct perf_event_context
*
2704 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2706 struct perf_event_context
*ctx
;
2708 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2712 __perf_event_init_context(ctx
);
2715 get_task_struct(task
);
2722 static struct task_struct
*
2723 find_lively_task_by_vpid(pid_t vpid
)
2725 struct task_struct
*task
;
2732 task
= find_task_by_vpid(vpid
);
2734 get_task_struct(task
);
2738 return ERR_PTR(-ESRCH
);
2740 /* Reuse ptrace permission checks for now. */
2742 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2747 put_task_struct(task
);
2748 return ERR_PTR(err
);
2753 * Returns a matching context with refcount and pincount.
2755 static struct perf_event_context
*
2756 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2758 struct perf_event_context
*ctx
;
2759 struct perf_cpu_context
*cpuctx
;
2760 unsigned long flags
;
2764 /* Must be root to operate on a CPU event: */
2765 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2766 return ERR_PTR(-EACCES
);
2769 * We could be clever and allow to attach a event to an
2770 * offline CPU and activate it when the CPU comes up, but
2773 if (!cpu_online(cpu
))
2774 return ERR_PTR(-ENODEV
);
2776 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2785 ctxn
= pmu
->task_ctx_nr
;
2790 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2794 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2798 ctx
= alloc_perf_context(pmu
, task
);
2806 mutex_lock(&task
->perf_event_mutex
);
2808 * If it has already passed perf_event_exit_task().
2809 * we must see PF_EXITING, it takes this mutex too.
2811 if (task
->flags
& PF_EXITING
)
2813 else if (task
->perf_event_ctxp
[ctxn
])
2817 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2819 mutex_unlock(&task
->perf_event_mutex
);
2821 if (unlikely(err
)) {
2822 put_task_struct(task
);
2834 return ERR_PTR(err
);
2837 static void perf_event_free_filter(struct perf_event
*event
);
2839 static void free_event_rcu(struct rcu_head
*head
)
2841 struct perf_event
*event
;
2843 event
= container_of(head
, struct perf_event
, rcu_head
);
2845 put_pid_ns(event
->ns
);
2846 perf_event_free_filter(event
);
2850 static void perf_buffer_put(struct perf_buffer
*buffer
);
2852 static void free_event(struct perf_event
*event
)
2854 irq_work_sync(&event
->pending
);
2856 if (!event
->parent
) {
2857 if (event
->attach_state
& PERF_ATTACH_TASK
)
2858 jump_label_dec(&perf_sched_events
);
2859 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2860 atomic_dec(&nr_mmap_events
);
2861 if (event
->attr
.comm
)
2862 atomic_dec(&nr_comm_events
);
2863 if (event
->attr
.task
)
2864 atomic_dec(&nr_task_events
);
2865 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2866 put_callchain_buffers();
2869 if (event
->buffer
) {
2870 perf_buffer_put(event
->buffer
);
2871 event
->buffer
= NULL
;
2874 if (is_cgroup_event(event
))
2875 perf_detach_cgroup(event
);
2878 event
->destroy(event
);
2881 put_ctx(event
->ctx
);
2883 call_rcu(&event
->rcu_head
, free_event_rcu
);
2886 int perf_event_release_kernel(struct perf_event
*event
)
2888 struct perf_event_context
*ctx
= event
->ctx
;
2891 * Remove from the PMU, can't get re-enabled since we got
2892 * here because the last ref went.
2894 perf_event_disable(event
);
2896 WARN_ON_ONCE(ctx
->parent_ctx
);
2898 * There are two ways this annotation is useful:
2900 * 1) there is a lock recursion from perf_event_exit_task
2901 * see the comment there.
2903 * 2) there is a lock-inversion with mmap_sem through
2904 * perf_event_read_group(), which takes faults while
2905 * holding ctx->mutex, however this is called after
2906 * the last filedesc died, so there is no possibility
2907 * to trigger the AB-BA case.
2909 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2910 raw_spin_lock_irq(&ctx
->lock
);
2911 perf_group_detach(event
);
2912 list_del_event(event
, ctx
);
2913 raw_spin_unlock_irq(&ctx
->lock
);
2914 mutex_unlock(&ctx
->mutex
);
2920 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2923 * Called when the last reference to the file is gone.
2925 static int perf_release(struct inode
*inode
, struct file
*file
)
2927 struct perf_event
*event
= file
->private_data
;
2928 struct task_struct
*owner
;
2930 file
->private_data
= NULL
;
2933 owner
= ACCESS_ONCE(event
->owner
);
2935 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2936 * !owner it means the list deletion is complete and we can indeed
2937 * free this event, otherwise we need to serialize on
2938 * owner->perf_event_mutex.
2940 smp_read_barrier_depends();
2943 * Since delayed_put_task_struct() also drops the last
2944 * task reference we can safely take a new reference
2945 * while holding the rcu_read_lock().
2947 get_task_struct(owner
);
2952 mutex_lock(&owner
->perf_event_mutex
);
2954 * We have to re-check the event->owner field, if it is cleared
2955 * we raced with perf_event_exit_task(), acquiring the mutex
2956 * ensured they're done, and we can proceed with freeing the
2960 list_del_init(&event
->owner_entry
);
2961 mutex_unlock(&owner
->perf_event_mutex
);
2962 put_task_struct(owner
);
2965 return perf_event_release_kernel(event
);
2968 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
2970 struct perf_event
*child
;
2976 mutex_lock(&event
->child_mutex
);
2977 total
+= perf_event_read(event
);
2978 *enabled
+= event
->total_time_enabled
+
2979 atomic64_read(&event
->child_total_time_enabled
);
2980 *running
+= event
->total_time_running
+
2981 atomic64_read(&event
->child_total_time_running
);
2983 list_for_each_entry(child
, &event
->child_list
, child_list
) {
2984 total
+= perf_event_read(child
);
2985 *enabled
+= child
->total_time_enabled
;
2986 *running
+= child
->total_time_running
;
2988 mutex_unlock(&event
->child_mutex
);
2992 EXPORT_SYMBOL_GPL(perf_event_read_value
);
2994 static int perf_event_read_group(struct perf_event
*event
,
2995 u64 read_format
, char __user
*buf
)
2997 struct perf_event
*leader
= event
->group_leader
, *sub
;
2998 int n
= 0, size
= 0, ret
= -EFAULT
;
2999 struct perf_event_context
*ctx
= leader
->ctx
;
3001 u64 count
, enabled
, running
;
3003 mutex_lock(&ctx
->mutex
);
3004 count
= perf_event_read_value(leader
, &enabled
, &running
);
3006 values
[n
++] = 1 + leader
->nr_siblings
;
3007 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3008 values
[n
++] = enabled
;
3009 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3010 values
[n
++] = running
;
3011 values
[n
++] = count
;
3012 if (read_format
& PERF_FORMAT_ID
)
3013 values
[n
++] = primary_event_id(leader
);
3015 size
= n
* sizeof(u64
);
3017 if (copy_to_user(buf
, values
, size
))
3022 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3025 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3026 if (read_format
& PERF_FORMAT_ID
)
3027 values
[n
++] = primary_event_id(sub
);
3029 size
= n
* sizeof(u64
);
3031 if (copy_to_user(buf
+ ret
, values
, size
)) {
3039 mutex_unlock(&ctx
->mutex
);
3044 static int perf_event_read_one(struct perf_event
*event
,
3045 u64 read_format
, char __user
*buf
)
3047 u64 enabled
, running
;
3051 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3052 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3053 values
[n
++] = enabled
;
3054 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3055 values
[n
++] = running
;
3056 if (read_format
& PERF_FORMAT_ID
)
3057 values
[n
++] = primary_event_id(event
);
3059 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3062 return n
* sizeof(u64
);
3066 * Read the performance event - simple non blocking version for now
3069 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3071 u64 read_format
= event
->attr
.read_format
;
3075 * Return end-of-file for a read on a event that is in
3076 * error state (i.e. because it was pinned but it couldn't be
3077 * scheduled on to the CPU at some point).
3079 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3082 if (count
< event
->read_size
)
3085 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3086 if (read_format
& PERF_FORMAT_GROUP
)
3087 ret
= perf_event_read_group(event
, read_format
, buf
);
3089 ret
= perf_event_read_one(event
, read_format
, buf
);
3095 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3097 struct perf_event
*event
= file
->private_data
;
3099 return perf_read_hw(event
, buf
, count
);
3102 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3104 struct perf_event
*event
= file
->private_data
;
3105 struct perf_buffer
*buffer
;
3106 unsigned int events
= POLL_HUP
;
3109 buffer
= rcu_dereference(event
->buffer
);
3111 events
= atomic_xchg(&buffer
->poll
, 0);
3114 poll_wait(file
, &event
->waitq
, wait
);
3119 static void perf_event_reset(struct perf_event
*event
)
3121 (void)perf_event_read(event
);
3122 local64_set(&event
->count
, 0);
3123 perf_event_update_userpage(event
);
3127 * Holding the top-level event's child_mutex means that any
3128 * descendant process that has inherited this event will block
3129 * in sync_child_event if it goes to exit, thus satisfying the
3130 * task existence requirements of perf_event_enable/disable.
3132 static void perf_event_for_each_child(struct perf_event
*event
,
3133 void (*func
)(struct perf_event
*))
3135 struct perf_event
*child
;
3137 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3138 mutex_lock(&event
->child_mutex
);
3140 list_for_each_entry(child
, &event
->child_list
, child_list
)
3142 mutex_unlock(&event
->child_mutex
);
3145 static void perf_event_for_each(struct perf_event
*event
,
3146 void (*func
)(struct perf_event
*))
3148 struct perf_event_context
*ctx
= event
->ctx
;
3149 struct perf_event
*sibling
;
3151 WARN_ON_ONCE(ctx
->parent_ctx
);
3152 mutex_lock(&ctx
->mutex
);
3153 event
= event
->group_leader
;
3155 perf_event_for_each_child(event
, func
);
3157 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3158 perf_event_for_each_child(event
, func
);
3159 mutex_unlock(&ctx
->mutex
);
3162 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3164 struct perf_event_context
*ctx
= event
->ctx
;
3168 if (!is_sampling_event(event
))
3171 if (copy_from_user(&value
, arg
, sizeof(value
)))
3177 raw_spin_lock_irq(&ctx
->lock
);
3178 if (event
->attr
.freq
) {
3179 if (value
> sysctl_perf_event_sample_rate
) {
3184 event
->attr
.sample_freq
= value
;
3186 event
->attr
.sample_period
= value
;
3187 event
->hw
.sample_period
= value
;
3190 raw_spin_unlock_irq(&ctx
->lock
);
3195 static const struct file_operations perf_fops
;
3197 static struct perf_event
*perf_fget_light(int fd
, int *fput_needed
)
3201 file
= fget_light(fd
, fput_needed
);
3203 return ERR_PTR(-EBADF
);
3205 if (file
->f_op
!= &perf_fops
) {
3206 fput_light(file
, *fput_needed
);
3208 return ERR_PTR(-EBADF
);
3211 return file
->private_data
;
3214 static int perf_event_set_output(struct perf_event
*event
,
3215 struct perf_event
*output_event
);
3216 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3218 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3220 struct perf_event
*event
= file
->private_data
;
3221 void (*func
)(struct perf_event
*);
3225 case PERF_EVENT_IOC_ENABLE
:
3226 func
= perf_event_enable
;
3228 case PERF_EVENT_IOC_DISABLE
:
3229 func
= perf_event_disable
;
3231 case PERF_EVENT_IOC_RESET
:
3232 func
= perf_event_reset
;
3235 case PERF_EVENT_IOC_REFRESH
:
3236 return perf_event_refresh(event
, arg
);
3238 case PERF_EVENT_IOC_PERIOD
:
3239 return perf_event_period(event
, (u64 __user
*)arg
);
3241 case PERF_EVENT_IOC_SET_OUTPUT
:
3243 struct perf_event
*output_event
= NULL
;
3244 int fput_needed
= 0;
3248 output_event
= perf_fget_light(arg
, &fput_needed
);
3249 if (IS_ERR(output_event
))
3250 return PTR_ERR(output_event
);
3253 ret
= perf_event_set_output(event
, output_event
);
3255 fput_light(output_event
->filp
, fput_needed
);
3260 case PERF_EVENT_IOC_SET_FILTER
:
3261 return perf_event_set_filter(event
, (void __user
*)arg
);
3267 if (flags
& PERF_IOC_FLAG_GROUP
)
3268 perf_event_for_each(event
, func
);
3270 perf_event_for_each_child(event
, func
);
3275 int perf_event_task_enable(void)
3277 struct perf_event
*event
;
3279 mutex_lock(¤t
->perf_event_mutex
);
3280 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3281 perf_event_for_each_child(event
, perf_event_enable
);
3282 mutex_unlock(¤t
->perf_event_mutex
);
3287 int perf_event_task_disable(void)
3289 struct perf_event
*event
;
3291 mutex_lock(¤t
->perf_event_mutex
);
3292 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3293 perf_event_for_each_child(event
, perf_event_disable
);
3294 mutex_unlock(¤t
->perf_event_mutex
);
3299 #ifndef PERF_EVENT_INDEX_OFFSET
3300 # define PERF_EVENT_INDEX_OFFSET 0
3303 static int perf_event_index(struct perf_event
*event
)
3305 if (event
->hw
.state
& PERF_HES_STOPPED
)
3308 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3311 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
3315 * Callers need to ensure there can be no nesting of this function, otherwise
3316 * the seqlock logic goes bad. We can not serialize this because the arch
3317 * code calls this from NMI context.
3319 void perf_event_update_userpage(struct perf_event
*event
)
3321 struct perf_event_mmap_page
*userpg
;
3322 struct perf_buffer
*buffer
;
3325 buffer
= rcu_dereference(event
->buffer
);
3329 userpg
= buffer
->user_page
;
3332 * Disable preemption so as to not let the corresponding user-space
3333 * spin too long if we get preempted.
3338 userpg
->index
= perf_event_index(event
);
3339 userpg
->offset
= perf_event_count(event
);
3340 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3341 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3343 userpg
->time_enabled
= event
->total_time_enabled
+
3344 atomic64_read(&event
->child_total_time_enabled
);
3346 userpg
->time_running
= event
->total_time_running
+
3347 atomic64_read(&event
->child_total_time_running
);
3356 static unsigned long perf_data_size(struct perf_buffer
*buffer
);
3359 perf_buffer_init(struct perf_buffer
*buffer
, long watermark
, int flags
)
3361 long max_size
= perf_data_size(buffer
);
3364 buffer
->watermark
= min(max_size
, watermark
);
3366 if (!buffer
->watermark
)
3367 buffer
->watermark
= max_size
/ 2;
3369 if (flags
& PERF_BUFFER_WRITABLE
)
3370 buffer
->writable
= 1;
3372 atomic_set(&buffer
->refcount
, 1);
3375 #ifndef CONFIG_PERF_USE_VMALLOC
3378 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
3381 static struct page
*
3382 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
3384 if (pgoff
> buffer
->nr_pages
)
3388 return virt_to_page(buffer
->user_page
);
3390 return virt_to_page(buffer
->data_pages
[pgoff
- 1]);
3393 static void *perf_mmap_alloc_page(int cpu
)
3398 node
= (cpu
== -1) ? cpu
: cpu_to_node(cpu
);
3399 page
= alloc_pages_node(node
, GFP_KERNEL
| __GFP_ZERO
, 0);
3403 return page_address(page
);
3406 static struct perf_buffer
*
3407 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
3409 struct perf_buffer
*buffer
;
3413 size
= sizeof(struct perf_buffer
);
3414 size
+= nr_pages
* sizeof(void *);
3416 buffer
= kzalloc(size
, GFP_KERNEL
);
3420 buffer
->user_page
= perf_mmap_alloc_page(cpu
);
3421 if (!buffer
->user_page
)
3422 goto fail_user_page
;
3424 for (i
= 0; i
< nr_pages
; i
++) {
3425 buffer
->data_pages
[i
] = perf_mmap_alloc_page(cpu
);
3426 if (!buffer
->data_pages
[i
])
3427 goto fail_data_pages
;
3430 buffer
->nr_pages
= nr_pages
;
3432 perf_buffer_init(buffer
, watermark
, flags
);
3437 for (i
--; i
>= 0; i
--)
3438 free_page((unsigned long)buffer
->data_pages
[i
]);
3440 free_page((unsigned long)buffer
->user_page
);
3449 static void perf_mmap_free_page(unsigned long addr
)
3451 struct page
*page
= virt_to_page((void *)addr
);
3453 page
->mapping
= NULL
;
3457 static void perf_buffer_free(struct perf_buffer
*buffer
)
3461 perf_mmap_free_page((unsigned long)buffer
->user_page
);
3462 for (i
= 0; i
< buffer
->nr_pages
; i
++)
3463 perf_mmap_free_page((unsigned long)buffer
->data_pages
[i
]);
3467 static inline int page_order(struct perf_buffer
*buffer
)
3475 * Back perf_mmap() with vmalloc memory.
3477 * Required for architectures that have d-cache aliasing issues.
3480 static inline int page_order(struct perf_buffer
*buffer
)
3482 return buffer
->page_order
;
3485 static struct page
*
3486 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
3488 if (pgoff
> (1UL << page_order(buffer
)))
3491 return vmalloc_to_page((void *)buffer
->user_page
+ pgoff
* PAGE_SIZE
);
3494 static void perf_mmap_unmark_page(void *addr
)
3496 struct page
*page
= vmalloc_to_page(addr
);
3498 page
->mapping
= NULL
;
3501 static void perf_buffer_free_work(struct work_struct
*work
)
3503 struct perf_buffer
*buffer
;
3507 buffer
= container_of(work
, struct perf_buffer
, work
);
3508 nr
= 1 << page_order(buffer
);
3510 base
= buffer
->user_page
;
3511 for (i
= 0; i
< nr
+ 1; i
++)
3512 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
3518 static void perf_buffer_free(struct perf_buffer
*buffer
)
3520 schedule_work(&buffer
->work
);
3523 static struct perf_buffer
*
3524 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
3526 struct perf_buffer
*buffer
;
3530 size
= sizeof(struct perf_buffer
);
3531 size
+= sizeof(void *);
3533 buffer
= kzalloc(size
, GFP_KERNEL
);
3537 INIT_WORK(&buffer
->work
, perf_buffer_free_work
);
3539 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
3543 buffer
->user_page
= all_buf
;
3544 buffer
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
3545 buffer
->page_order
= ilog2(nr_pages
);
3546 buffer
->nr_pages
= 1;
3548 perf_buffer_init(buffer
, watermark
, flags
);
3561 static unsigned long perf_data_size(struct perf_buffer
*buffer
)
3563 return buffer
->nr_pages
<< (PAGE_SHIFT
+ page_order(buffer
));
3566 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3568 struct perf_event
*event
= vma
->vm_file
->private_data
;
3569 struct perf_buffer
*buffer
;
3570 int ret
= VM_FAULT_SIGBUS
;
3572 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3573 if (vmf
->pgoff
== 0)
3579 buffer
= rcu_dereference(event
->buffer
);
3583 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3586 vmf
->page
= perf_mmap_to_page(buffer
, vmf
->pgoff
);
3590 get_page(vmf
->page
);
3591 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3592 vmf
->page
->index
= vmf
->pgoff
;
3601 static void perf_buffer_free_rcu(struct rcu_head
*rcu_head
)
3603 struct perf_buffer
*buffer
;
3605 buffer
= container_of(rcu_head
, struct perf_buffer
, rcu_head
);
3606 perf_buffer_free(buffer
);
3609 static struct perf_buffer
*perf_buffer_get(struct perf_event
*event
)
3611 struct perf_buffer
*buffer
;
3614 buffer
= rcu_dereference(event
->buffer
);
3616 if (!atomic_inc_not_zero(&buffer
->refcount
))
3624 static void perf_buffer_put(struct perf_buffer
*buffer
)
3626 if (!atomic_dec_and_test(&buffer
->refcount
))
3629 call_rcu(&buffer
->rcu_head
, perf_buffer_free_rcu
);
3632 static void perf_mmap_open(struct vm_area_struct
*vma
)
3634 struct perf_event
*event
= vma
->vm_file
->private_data
;
3636 atomic_inc(&event
->mmap_count
);
3639 static void perf_mmap_close(struct vm_area_struct
*vma
)
3641 struct perf_event
*event
= vma
->vm_file
->private_data
;
3643 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3644 unsigned long size
= perf_data_size(event
->buffer
);
3645 struct user_struct
*user
= event
->mmap_user
;
3646 struct perf_buffer
*buffer
= event
->buffer
;
3648 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3649 vma
->vm_mm
->locked_vm
-= event
->mmap_locked
;
3650 rcu_assign_pointer(event
->buffer
, NULL
);
3651 mutex_unlock(&event
->mmap_mutex
);
3653 perf_buffer_put(buffer
);
3658 static const struct vm_operations_struct perf_mmap_vmops
= {
3659 .open
= perf_mmap_open
,
3660 .close
= perf_mmap_close
,
3661 .fault
= perf_mmap_fault
,
3662 .page_mkwrite
= perf_mmap_fault
,
3665 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3667 struct perf_event
*event
= file
->private_data
;
3668 unsigned long user_locked
, user_lock_limit
;
3669 struct user_struct
*user
= current_user();
3670 unsigned long locked
, lock_limit
;
3671 struct perf_buffer
*buffer
;
3672 unsigned long vma_size
;
3673 unsigned long nr_pages
;
3674 long user_extra
, extra
;
3675 int ret
= 0, flags
= 0;
3678 * Don't allow mmap() of inherited per-task counters. This would
3679 * create a performance issue due to all children writing to the
3682 if (event
->cpu
== -1 && event
->attr
.inherit
)
3685 if (!(vma
->vm_flags
& VM_SHARED
))
3688 vma_size
= vma
->vm_end
- vma
->vm_start
;
3689 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3692 * If we have buffer pages ensure they're a power-of-two number, so we
3693 * can do bitmasks instead of modulo.
3695 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3698 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3701 if (vma
->vm_pgoff
!= 0)
3704 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3705 mutex_lock(&event
->mmap_mutex
);
3706 if (event
->buffer
) {
3707 if (event
->buffer
->nr_pages
== nr_pages
)
3708 atomic_inc(&event
->buffer
->refcount
);
3714 user_extra
= nr_pages
+ 1;
3715 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3718 * Increase the limit linearly with more CPUs:
3720 user_lock_limit
*= num_online_cpus();
3722 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3725 if (user_locked
> user_lock_limit
)
3726 extra
= user_locked
- user_lock_limit
;
3728 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3729 lock_limit
>>= PAGE_SHIFT
;
3730 locked
= vma
->vm_mm
->locked_vm
+ extra
;
3732 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3733 !capable(CAP_IPC_LOCK
)) {
3738 WARN_ON(event
->buffer
);
3740 if (vma
->vm_flags
& VM_WRITE
)
3741 flags
|= PERF_BUFFER_WRITABLE
;
3743 buffer
= perf_buffer_alloc(nr_pages
, event
->attr
.wakeup_watermark
,
3749 rcu_assign_pointer(event
->buffer
, buffer
);
3751 atomic_long_add(user_extra
, &user
->locked_vm
);
3752 event
->mmap_locked
= extra
;
3753 event
->mmap_user
= get_current_user();
3754 vma
->vm_mm
->locked_vm
+= event
->mmap_locked
;
3758 atomic_inc(&event
->mmap_count
);
3759 mutex_unlock(&event
->mmap_mutex
);
3761 vma
->vm_flags
|= VM_RESERVED
;
3762 vma
->vm_ops
= &perf_mmap_vmops
;
3767 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3769 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3770 struct perf_event
*event
= filp
->private_data
;
3773 mutex_lock(&inode
->i_mutex
);
3774 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3775 mutex_unlock(&inode
->i_mutex
);
3783 static const struct file_operations perf_fops
= {
3784 .llseek
= no_llseek
,
3785 .release
= perf_release
,
3788 .unlocked_ioctl
= perf_ioctl
,
3789 .compat_ioctl
= perf_ioctl
,
3791 .fasync
= perf_fasync
,
3797 * If there's data, ensure we set the poll() state and publish everything
3798 * to user-space before waking everybody up.
3801 void perf_event_wakeup(struct perf_event
*event
)
3803 wake_up_all(&event
->waitq
);
3805 if (event
->pending_kill
) {
3806 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3807 event
->pending_kill
= 0;
3811 static void perf_pending_event(struct irq_work
*entry
)
3813 struct perf_event
*event
= container_of(entry
,
3814 struct perf_event
, pending
);
3816 if (event
->pending_disable
) {
3817 event
->pending_disable
= 0;
3818 __perf_event_disable(event
);
3821 if (event
->pending_wakeup
) {
3822 event
->pending_wakeup
= 0;
3823 perf_event_wakeup(event
);
3828 * We assume there is only KVM supporting the callbacks.
3829 * Later on, we might change it to a list if there is
3830 * another virtualization implementation supporting the callbacks.
3832 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3834 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3836 perf_guest_cbs
= cbs
;
3839 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3841 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3843 perf_guest_cbs
= NULL
;
3846 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3851 static bool perf_output_space(struct perf_buffer
*buffer
, unsigned long tail
,
3852 unsigned long offset
, unsigned long head
)
3856 if (!buffer
->writable
)
3859 mask
= perf_data_size(buffer
) - 1;
3861 offset
= (offset
- tail
) & mask
;
3862 head
= (head
- tail
) & mask
;
3864 if ((int)(head
- offset
) < 0)
3870 static void perf_output_wakeup(struct perf_output_handle
*handle
)
3872 atomic_set(&handle
->buffer
->poll
, POLL_IN
);
3875 handle
->event
->pending_wakeup
= 1;
3876 irq_work_queue(&handle
->event
->pending
);
3878 perf_event_wakeup(handle
->event
);
3882 * We need to ensure a later event_id doesn't publish a head when a former
3883 * event isn't done writing. However since we need to deal with NMIs we
3884 * cannot fully serialize things.
3886 * We only publish the head (and generate a wakeup) when the outer-most
3889 static void perf_output_get_handle(struct perf_output_handle
*handle
)
3891 struct perf_buffer
*buffer
= handle
->buffer
;
3894 local_inc(&buffer
->nest
);
3895 handle
->wakeup
= local_read(&buffer
->wakeup
);
3898 static void perf_output_put_handle(struct perf_output_handle
*handle
)
3900 struct perf_buffer
*buffer
= handle
->buffer
;
3904 head
= local_read(&buffer
->head
);
3907 * IRQ/NMI can happen here, which means we can miss a head update.
3910 if (!local_dec_and_test(&buffer
->nest
))
3914 * Publish the known good head. Rely on the full barrier implied
3915 * by atomic_dec_and_test() order the buffer->head read and this
3918 buffer
->user_page
->data_head
= head
;
3921 * Now check if we missed an update, rely on the (compiler)
3922 * barrier in atomic_dec_and_test() to re-read buffer->head.
3924 if (unlikely(head
!= local_read(&buffer
->head
))) {
3925 local_inc(&buffer
->nest
);
3929 if (handle
->wakeup
!= local_read(&buffer
->wakeup
))
3930 perf_output_wakeup(handle
);
3936 __always_inline
void perf_output_copy(struct perf_output_handle
*handle
,
3937 const void *buf
, unsigned int len
)
3940 unsigned long size
= min_t(unsigned long, handle
->size
, len
);
3942 memcpy(handle
->addr
, buf
, size
);
3945 handle
->addr
+= size
;
3947 handle
->size
-= size
;
3948 if (!handle
->size
) {
3949 struct perf_buffer
*buffer
= handle
->buffer
;
3952 handle
->page
&= buffer
->nr_pages
- 1;
3953 handle
->addr
= buffer
->data_pages
[handle
->page
];
3954 handle
->size
= PAGE_SIZE
<< page_order(buffer
);
3959 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3960 struct perf_sample_data
*data
,
3961 struct perf_event
*event
)
3963 u64 sample_type
= event
->attr
.sample_type
;
3965 data
->type
= sample_type
;
3966 header
->size
+= event
->id_header_size
;
3968 if (sample_type
& PERF_SAMPLE_TID
) {
3969 /* namespace issues */
3970 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3971 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3974 if (sample_type
& PERF_SAMPLE_TIME
)
3975 data
->time
= perf_clock();
3977 if (sample_type
& PERF_SAMPLE_ID
)
3978 data
->id
= primary_event_id(event
);
3980 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3981 data
->stream_id
= event
->id
;
3983 if (sample_type
& PERF_SAMPLE_CPU
) {
3984 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3985 data
->cpu_entry
.reserved
= 0;
3989 static void perf_event_header__init_id(struct perf_event_header
*header
,
3990 struct perf_sample_data
*data
,
3991 struct perf_event
*event
)
3993 if (event
->attr
.sample_id_all
)
3994 __perf_event_header__init_id(header
, data
, event
);
3997 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
3998 struct perf_sample_data
*data
)
4000 u64 sample_type
= data
->type
;
4002 if (sample_type
& PERF_SAMPLE_TID
)
4003 perf_output_put(handle
, data
->tid_entry
);
4005 if (sample_type
& PERF_SAMPLE_TIME
)
4006 perf_output_put(handle
, data
->time
);
4008 if (sample_type
& PERF_SAMPLE_ID
)
4009 perf_output_put(handle
, data
->id
);
4011 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4012 perf_output_put(handle
, data
->stream_id
);
4014 if (sample_type
& PERF_SAMPLE_CPU
)
4015 perf_output_put(handle
, data
->cpu_entry
);
4018 static void perf_event__output_id_sample(struct perf_event
*event
,
4019 struct perf_output_handle
*handle
,
4020 struct perf_sample_data
*sample
)
4022 if (event
->attr
.sample_id_all
)
4023 __perf_event__output_id_sample(handle
, sample
);
4026 int perf_output_begin(struct perf_output_handle
*handle
,
4027 struct perf_event
*event
, unsigned int size
,
4028 int nmi
, int sample
)
4030 struct perf_buffer
*buffer
;
4031 unsigned long tail
, offset
, head
;
4033 struct perf_sample_data sample_data
;
4035 struct perf_event_header header
;
4042 * For inherited events we send all the output towards the parent.
4045 event
= event
->parent
;
4047 buffer
= rcu_dereference(event
->buffer
);
4051 handle
->buffer
= buffer
;
4052 handle
->event
= event
;
4054 handle
->sample
= sample
;
4056 if (!buffer
->nr_pages
)
4059 have_lost
= local_read(&buffer
->lost
);
4061 lost_event
.header
.size
= sizeof(lost_event
);
4062 perf_event_header__init_id(&lost_event
.header
, &sample_data
,
4064 size
+= lost_event
.header
.size
;
4067 perf_output_get_handle(handle
);
4071 * Userspace could choose to issue a mb() before updating the
4072 * tail pointer. So that all reads will be completed before the
4075 tail
= ACCESS_ONCE(buffer
->user_page
->data_tail
);
4077 offset
= head
= local_read(&buffer
->head
);
4079 if (unlikely(!perf_output_space(buffer
, tail
, offset
, head
)))
4081 } while (local_cmpxchg(&buffer
->head
, offset
, head
) != offset
);
4083 if (head
- local_read(&buffer
->wakeup
) > buffer
->watermark
)
4084 local_add(buffer
->watermark
, &buffer
->wakeup
);
4086 handle
->page
= offset
>> (PAGE_SHIFT
+ page_order(buffer
));
4087 handle
->page
&= buffer
->nr_pages
- 1;
4088 handle
->size
= offset
& ((PAGE_SIZE
<< page_order(buffer
)) - 1);
4089 handle
->addr
= buffer
->data_pages
[handle
->page
];
4090 handle
->addr
+= handle
->size
;
4091 handle
->size
= (PAGE_SIZE
<< page_order(buffer
)) - handle
->size
;
4094 lost_event
.header
.type
= PERF_RECORD_LOST
;
4095 lost_event
.header
.misc
= 0;
4096 lost_event
.id
= event
->id
;
4097 lost_event
.lost
= local_xchg(&buffer
->lost
, 0);
4099 perf_output_put(handle
, lost_event
);
4100 perf_event__output_id_sample(event
, handle
, &sample_data
);
4106 local_inc(&buffer
->lost
);
4107 perf_output_put_handle(handle
);
4114 void perf_output_end(struct perf_output_handle
*handle
)
4116 struct perf_event
*event
= handle
->event
;
4117 struct perf_buffer
*buffer
= handle
->buffer
;
4119 int wakeup_events
= event
->attr
.wakeup_events
;
4121 if (handle
->sample
&& wakeup_events
) {
4122 int events
= local_inc_return(&buffer
->events
);
4123 if (events
>= wakeup_events
) {
4124 local_sub(wakeup_events
, &buffer
->events
);
4125 local_inc(&buffer
->wakeup
);
4129 perf_output_put_handle(handle
);
4133 static void perf_output_read_one(struct perf_output_handle
*handle
,
4134 struct perf_event
*event
,
4135 u64 enabled
, u64 running
)
4137 u64 read_format
= event
->attr
.read_format
;
4141 values
[n
++] = perf_event_count(event
);
4142 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4143 values
[n
++] = enabled
+
4144 atomic64_read(&event
->child_total_time_enabled
);
4146 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4147 values
[n
++] = running
+
4148 atomic64_read(&event
->child_total_time_running
);
4150 if (read_format
& PERF_FORMAT_ID
)
4151 values
[n
++] = primary_event_id(event
);
4153 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4157 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
4159 static void perf_output_read_group(struct perf_output_handle
*handle
,
4160 struct perf_event
*event
,
4161 u64 enabled
, u64 running
)
4163 struct perf_event
*leader
= event
->group_leader
, *sub
;
4164 u64 read_format
= event
->attr
.read_format
;
4168 values
[n
++] = 1 + leader
->nr_siblings
;
4170 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4171 values
[n
++] = enabled
;
4173 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4174 values
[n
++] = running
;
4176 if (leader
!= event
)
4177 leader
->pmu
->read(leader
);
4179 values
[n
++] = perf_event_count(leader
);
4180 if (read_format
& PERF_FORMAT_ID
)
4181 values
[n
++] = primary_event_id(leader
);
4183 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4185 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4189 sub
->pmu
->read(sub
);
4191 values
[n
++] = perf_event_count(sub
);
4192 if (read_format
& PERF_FORMAT_ID
)
4193 values
[n
++] = primary_event_id(sub
);
4195 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4199 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
4200 PERF_FORMAT_TOTAL_TIME_RUNNING)
4202 static void perf_output_read(struct perf_output_handle
*handle
,
4203 struct perf_event
*event
)
4205 u64 enabled
= 0, running
= 0, now
, ctx_time
;
4206 u64 read_format
= event
->attr
.read_format
;
4209 * compute total_time_enabled, total_time_running
4210 * based on snapshot values taken when the event
4211 * was last scheduled in.
4213 * we cannot simply called update_context_time()
4214 * because of locking issue as we are called in
4217 if (read_format
& PERF_FORMAT_TOTAL_TIMES
) {
4219 ctx_time
= event
->shadow_ctx_time
+ now
;
4220 enabled
= ctx_time
- event
->tstamp_enabled
;
4221 running
= ctx_time
- event
->tstamp_running
;
4224 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
4225 perf_output_read_group(handle
, event
, enabled
, running
);
4227 perf_output_read_one(handle
, event
, enabled
, running
);
4230 void perf_output_sample(struct perf_output_handle
*handle
,
4231 struct perf_event_header
*header
,
4232 struct perf_sample_data
*data
,
4233 struct perf_event
*event
)
4235 u64 sample_type
= data
->type
;
4237 perf_output_put(handle
, *header
);
4239 if (sample_type
& PERF_SAMPLE_IP
)
4240 perf_output_put(handle
, data
->ip
);
4242 if (sample_type
& PERF_SAMPLE_TID
)
4243 perf_output_put(handle
, data
->tid_entry
);
4245 if (sample_type
& PERF_SAMPLE_TIME
)
4246 perf_output_put(handle
, data
->time
);
4248 if (sample_type
& PERF_SAMPLE_ADDR
)
4249 perf_output_put(handle
, data
->addr
);
4251 if (sample_type
& PERF_SAMPLE_ID
)
4252 perf_output_put(handle
, data
->id
);
4254 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4255 perf_output_put(handle
, data
->stream_id
);
4257 if (sample_type
& PERF_SAMPLE_CPU
)
4258 perf_output_put(handle
, data
->cpu_entry
);
4260 if (sample_type
& PERF_SAMPLE_PERIOD
)
4261 perf_output_put(handle
, data
->period
);
4263 if (sample_type
& PERF_SAMPLE_READ
)
4264 perf_output_read(handle
, event
);
4266 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4267 if (data
->callchain
) {
4270 if (data
->callchain
)
4271 size
+= data
->callchain
->nr
;
4273 size
*= sizeof(u64
);
4275 perf_output_copy(handle
, data
->callchain
, size
);
4278 perf_output_put(handle
, nr
);
4282 if (sample_type
& PERF_SAMPLE_RAW
) {
4284 perf_output_put(handle
, data
->raw
->size
);
4285 perf_output_copy(handle
, data
->raw
->data
,
4292 .size
= sizeof(u32
),
4295 perf_output_put(handle
, raw
);
4300 void perf_prepare_sample(struct perf_event_header
*header
,
4301 struct perf_sample_data
*data
,
4302 struct perf_event
*event
,
4303 struct pt_regs
*regs
)
4305 u64 sample_type
= event
->attr
.sample_type
;
4307 header
->type
= PERF_RECORD_SAMPLE
;
4308 header
->size
= sizeof(*header
) + event
->header_size
;
4311 header
->misc
|= perf_misc_flags(regs
);
4313 __perf_event_header__init_id(header
, data
, event
);
4315 if (sample_type
& PERF_SAMPLE_IP
)
4316 data
->ip
= perf_instruction_pointer(regs
);
4318 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4321 data
->callchain
= perf_callchain(regs
);
4323 if (data
->callchain
)
4324 size
+= data
->callchain
->nr
;
4326 header
->size
+= size
* sizeof(u64
);
4329 if (sample_type
& PERF_SAMPLE_RAW
) {
4330 int size
= sizeof(u32
);
4333 size
+= data
->raw
->size
;
4335 size
+= sizeof(u32
);
4337 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4338 header
->size
+= size
;
4342 static void perf_event_output(struct perf_event
*event
, int nmi
,
4343 struct perf_sample_data
*data
,
4344 struct pt_regs
*regs
)
4346 struct perf_output_handle handle
;
4347 struct perf_event_header header
;
4349 /* protect the callchain buffers */
4352 perf_prepare_sample(&header
, data
, event
, regs
);
4354 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
4357 perf_output_sample(&handle
, &header
, data
, event
);
4359 perf_output_end(&handle
);
4369 struct perf_read_event
{
4370 struct perf_event_header header
;
4377 perf_event_read_event(struct perf_event
*event
,
4378 struct task_struct
*task
)
4380 struct perf_output_handle handle
;
4381 struct perf_sample_data sample
;
4382 struct perf_read_event read_event
= {
4384 .type
= PERF_RECORD_READ
,
4386 .size
= sizeof(read_event
) + event
->read_size
,
4388 .pid
= perf_event_pid(event
, task
),
4389 .tid
= perf_event_tid(event
, task
),
4393 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4394 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
4398 perf_output_put(&handle
, read_event
);
4399 perf_output_read(&handle
, event
);
4400 perf_event__output_id_sample(event
, &handle
, &sample
);
4402 perf_output_end(&handle
);
4406 * task tracking -- fork/exit
4408 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
4411 struct perf_task_event
{
4412 struct task_struct
*task
;
4413 struct perf_event_context
*task_ctx
;
4416 struct perf_event_header header
;
4426 static void perf_event_task_output(struct perf_event
*event
,
4427 struct perf_task_event
*task_event
)
4429 struct perf_output_handle handle
;
4430 struct perf_sample_data sample
;
4431 struct task_struct
*task
= task_event
->task
;
4432 int ret
, size
= task_event
->event_id
.header
.size
;
4434 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4436 ret
= perf_output_begin(&handle
, event
,
4437 task_event
->event_id
.header
.size
, 0, 0);
4441 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4442 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4444 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4445 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4447 perf_output_put(&handle
, task_event
->event_id
);
4449 perf_event__output_id_sample(event
, &handle
, &sample
);
4451 perf_output_end(&handle
);
4453 task_event
->event_id
.header
.size
= size
;
4456 static int perf_event_task_match(struct perf_event
*event
)
4458 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4461 if (!event_filter_match(event
))
4464 if (event
->attr
.comm
|| event
->attr
.mmap
||
4465 event
->attr
.mmap_data
|| event
->attr
.task
)
4471 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
4472 struct perf_task_event
*task_event
)
4474 struct perf_event
*event
;
4476 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4477 if (perf_event_task_match(event
))
4478 perf_event_task_output(event
, task_event
);
4482 static void perf_event_task_event(struct perf_task_event
*task_event
)
4484 struct perf_cpu_context
*cpuctx
;
4485 struct perf_event_context
*ctx
;
4490 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4491 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4492 if (cpuctx
->active_pmu
!= pmu
)
4494 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
4496 ctx
= task_event
->task_ctx
;
4498 ctxn
= pmu
->task_ctx_nr
;
4501 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4504 perf_event_task_ctx(ctx
, task_event
);
4506 put_cpu_ptr(pmu
->pmu_cpu_context
);
4511 static void perf_event_task(struct task_struct
*task
,
4512 struct perf_event_context
*task_ctx
,
4515 struct perf_task_event task_event
;
4517 if (!atomic_read(&nr_comm_events
) &&
4518 !atomic_read(&nr_mmap_events
) &&
4519 !atomic_read(&nr_task_events
))
4522 task_event
= (struct perf_task_event
){
4524 .task_ctx
= task_ctx
,
4527 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4529 .size
= sizeof(task_event
.event_id
),
4535 .time
= perf_clock(),
4539 perf_event_task_event(&task_event
);
4542 void perf_event_fork(struct task_struct
*task
)
4544 perf_event_task(task
, NULL
, 1);
4551 struct perf_comm_event
{
4552 struct task_struct
*task
;
4557 struct perf_event_header header
;
4564 static void perf_event_comm_output(struct perf_event
*event
,
4565 struct perf_comm_event
*comm_event
)
4567 struct perf_output_handle handle
;
4568 struct perf_sample_data sample
;
4569 int size
= comm_event
->event_id
.header
.size
;
4572 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4573 ret
= perf_output_begin(&handle
, event
,
4574 comm_event
->event_id
.header
.size
, 0, 0);
4579 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4580 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4582 perf_output_put(&handle
, comm_event
->event_id
);
4583 perf_output_copy(&handle
, comm_event
->comm
,
4584 comm_event
->comm_size
);
4586 perf_event__output_id_sample(event
, &handle
, &sample
);
4588 perf_output_end(&handle
);
4590 comm_event
->event_id
.header
.size
= size
;
4593 static int perf_event_comm_match(struct perf_event
*event
)
4595 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4598 if (!event_filter_match(event
))
4601 if (event
->attr
.comm
)
4607 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4608 struct perf_comm_event
*comm_event
)
4610 struct perf_event
*event
;
4612 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4613 if (perf_event_comm_match(event
))
4614 perf_event_comm_output(event
, comm_event
);
4618 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4620 struct perf_cpu_context
*cpuctx
;
4621 struct perf_event_context
*ctx
;
4622 char comm
[TASK_COMM_LEN
];
4627 memset(comm
, 0, sizeof(comm
));
4628 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4629 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4631 comm_event
->comm
= comm
;
4632 comm_event
->comm_size
= size
;
4634 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4636 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4637 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4638 if (cpuctx
->active_pmu
!= pmu
)
4640 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4642 ctxn
= pmu
->task_ctx_nr
;
4646 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4648 perf_event_comm_ctx(ctx
, comm_event
);
4650 put_cpu_ptr(pmu
->pmu_cpu_context
);
4655 void perf_event_comm(struct task_struct
*task
)
4657 struct perf_comm_event comm_event
;
4658 struct perf_event_context
*ctx
;
4661 for_each_task_context_nr(ctxn
) {
4662 ctx
= task
->perf_event_ctxp
[ctxn
];
4666 perf_event_enable_on_exec(ctx
);
4669 if (!atomic_read(&nr_comm_events
))
4672 comm_event
= (struct perf_comm_event
){
4678 .type
= PERF_RECORD_COMM
,
4687 perf_event_comm_event(&comm_event
);
4694 struct perf_mmap_event
{
4695 struct vm_area_struct
*vma
;
4697 const char *file_name
;
4701 struct perf_event_header header
;
4711 static void perf_event_mmap_output(struct perf_event
*event
,
4712 struct perf_mmap_event
*mmap_event
)
4714 struct perf_output_handle handle
;
4715 struct perf_sample_data sample
;
4716 int size
= mmap_event
->event_id
.header
.size
;
4719 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4720 ret
= perf_output_begin(&handle
, event
,
4721 mmap_event
->event_id
.header
.size
, 0, 0);
4725 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4726 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4728 perf_output_put(&handle
, mmap_event
->event_id
);
4729 perf_output_copy(&handle
, mmap_event
->file_name
,
4730 mmap_event
->file_size
);
4732 perf_event__output_id_sample(event
, &handle
, &sample
);
4734 perf_output_end(&handle
);
4736 mmap_event
->event_id
.header
.size
= size
;
4739 static int perf_event_mmap_match(struct perf_event
*event
,
4740 struct perf_mmap_event
*mmap_event
,
4743 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4746 if (!event_filter_match(event
))
4749 if ((!executable
&& event
->attr
.mmap_data
) ||
4750 (executable
&& event
->attr
.mmap
))
4756 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4757 struct perf_mmap_event
*mmap_event
,
4760 struct perf_event
*event
;
4762 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4763 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4764 perf_event_mmap_output(event
, mmap_event
);
4768 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4770 struct perf_cpu_context
*cpuctx
;
4771 struct perf_event_context
*ctx
;
4772 struct vm_area_struct
*vma
= mmap_event
->vma
;
4773 struct file
*file
= vma
->vm_file
;
4781 memset(tmp
, 0, sizeof(tmp
));
4785 * d_path works from the end of the buffer backwards, so we
4786 * need to add enough zero bytes after the string to handle
4787 * the 64bit alignment we do later.
4789 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4791 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4794 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4796 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4800 if (arch_vma_name(mmap_event
->vma
)) {
4801 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4807 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4809 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4810 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4811 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4813 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4814 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4815 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4819 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4824 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4826 mmap_event
->file_name
= name
;
4827 mmap_event
->file_size
= size
;
4829 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4832 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4833 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4834 if (cpuctx
->active_pmu
!= pmu
)
4836 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4837 vma
->vm_flags
& VM_EXEC
);
4839 ctxn
= pmu
->task_ctx_nr
;
4843 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4845 perf_event_mmap_ctx(ctx
, mmap_event
,
4846 vma
->vm_flags
& VM_EXEC
);
4849 put_cpu_ptr(pmu
->pmu_cpu_context
);
4856 void perf_event_mmap(struct vm_area_struct
*vma
)
4858 struct perf_mmap_event mmap_event
;
4860 if (!atomic_read(&nr_mmap_events
))
4863 mmap_event
= (struct perf_mmap_event
){
4869 .type
= PERF_RECORD_MMAP
,
4870 .misc
= PERF_RECORD_MISC_USER
,
4875 .start
= vma
->vm_start
,
4876 .len
= vma
->vm_end
- vma
->vm_start
,
4877 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4881 perf_event_mmap_event(&mmap_event
);
4885 * IRQ throttle logging
4888 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4890 struct perf_output_handle handle
;
4891 struct perf_sample_data sample
;
4895 struct perf_event_header header
;
4899 } throttle_event
= {
4901 .type
= PERF_RECORD_THROTTLE
,
4903 .size
= sizeof(throttle_event
),
4905 .time
= perf_clock(),
4906 .id
= primary_event_id(event
),
4907 .stream_id
= event
->id
,
4911 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4913 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4915 ret
= perf_output_begin(&handle
, event
,
4916 throttle_event
.header
.size
, 1, 0);
4920 perf_output_put(&handle
, throttle_event
);
4921 perf_event__output_id_sample(event
, &handle
, &sample
);
4922 perf_output_end(&handle
);
4926 * Generic event overflow handling, sampling.
4929 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
4930 int throttle
, struct perf_sample_data
*data
,
4931 struct pt_regs
*regs
)
4933 int events
= atomic_read(&event
->event_limit
);
4934 struct hw_perf_event
*hwc
= &event
->hw
;
4938 * Non-sampling counters might still use the PMI to fold short
4939 * hardware counters, ignore those.
4941 if (unlikely(!is_sampling_event(event
)))
4947 if (hwc
->interrupts
!= MAX_INTERRUPTS
) {
4949 if (HZ
* hwc
->interrupts
>
4950 (u64
)sysctl_perf_event_sample_rate
) {
4951 hwc
->interrupts
= MAX_INTERRUPTS
;
4952 perf_log_throttle(event
, 0);
4957 * Keep re-disabling events even though on the previous
4958 * pass we disabled it - just in case we raced with a
4959 * sched-in and the event got enabled again:
4965 if (event
->attr
.freq
) {
4966 u64 now
= perf_clock();
4967 s64 delta
= now
- hwc
->freq_time_stamp
;
4969 hwc
->freq_time_stamp
= now
;
4971 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4972 perf_adjust_period(event
, delta
, hwc
->last_period
);
4976 * XXX event_limit might not quite work as expected on inherited
4980 event
->pending_kill
= POLL_IN
;
4981 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4983 event
->pending_kill
= POLL_HUP
;
4985 event
->pending_disable
= 1;
4986 irq_work_queue(&event
->pending
);
4988 perf_event_disable(event
);
4991 if (event
->overflow_handler
)
4992 event
->overflow_handler(event
, nmi
, data
, regs
);
4994 perf_event_output(event
, nmi
, data
, regs
);
4999 int perf_event_overflow(struct perf_event
*event
, int nmi
,
5000 struct perf_sample_data
*data
,
5001 struct pt_regs
*regs
)
5003 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
5007 * Generic software event infrastructure
5010 struct swevent_htable
{
5011 struct swevent_hlist
*swevent_hlist
;
5012 struct mutex hlist_mutex
;
5015 /* Recursion avoidance in each contexts */
5016 int recursion
[PERF_NR_CONTEXTS
];
5019 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
5022 * We directly increment event->count and keep a second value in
5023 * event->hw.period_left to count intervals. This period event
5024 * is kept in the range [-sample_period, 0] so that we can use the
5028 static u64
perf_swevent_set_period(struct perf_event
*event
)
5030 struct hw_perf_event
*hwc
= &event
->hw
;
5031 u64 period
= hwc
->last_period
;
5035 hwc
->last_period
= hwc
->sample_period
;
5038 old
= val
= local64_read(&hwc
->period_left
);
5042 nr
= div64_u64(period
+ val
, period
);
5043 offset
= nr
* period
;
5045 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
5051 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
5052 int nmi
, struct perf_sample_data
*data
,
5053 struct pt_regs
*regs
)
5055 struct hw_perf_event
*hwc
= &event
->hw
;
5058 data
->period
= event
->hw
.last_period
;
5060 overflow
= perf_swevent_set_period(event
);
5062 if (hwc
->interrupts
== MAX_INTERRUPTS
)
5065 for (; overflow
; overflow
--) {
5066 if (__perf_event_overflow(event
, nmi
, throttle
,
5069 * We inhibit the overflow from happening when
5070 * hwc->interrupts == MAX_INTERRUPTS.
5078 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
5079 int nmi
, struct perf_sample_data
*data
,
5080 struct pt_regs
*regs
)
5082 struct hw_perf_event
*hwc
= &event
->hw
;
5084 local64_add(nr
, &event
->count
);
5089 if (!is_sampling_event(event
))
5092 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
5093 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
5095 if (local64_add_negative(nr
, &hwc
->period_left
))
5098 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
5101 static int perf_exclude_event(struct perf_event
*event
,
5102 struct pt_regs
*regs
)
5104 if (event
->hw
.state
& PERF_HES_STOPPED
)
5108 if (event
->attr
.exclude_user
&& user_mode(regs
))
5111 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
5118 static int perf_swevent_match(struct perf_event
*event
,
5119 enum perf_type_id type
,
5121 struct perf_sample_data
*data
,
5122 struct pt_regs
*regs
)
5124 if (event
->attr
.type
!= type
)
5127 if (event
->attr
.config
!= event_id
)
5130 if (perf_exclude_event(event
, regs
))
5136 static inline u64
swevent_hash(u64 type
, u32 event_id
)
5138 u64 val
= event_id
| (type
<< 32);
5140 return hash_64(val
, SWEVENT_HLIST_BITS
);
5143 static inline struct hlist_head
*
5144 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
5146 u64 hash
= swevent_hash(type
, event_id
);
5148 return &hlist
->heads
[hash
];
5151 /* For the read side: events when they trigger */
5152 static inline struct hlist_head
*
5153 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
5155 struct swevent_hlist
*hlist
;
5157 hlist
= rcu_dereference(swhash
->swevent_hlist
);
5161 return __find_swevent_head(hlist
, type
, event_id
);
5164 /* For the event head insertion and removal in the hlist */
5165 static inline struct hlist_head
*
5166 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
5168 struct swevent_hlist
*hlist
;
5169 u32 event_id
= event
->attr
.config
;
5170 u64 type
= event
->attr
.type
;
5173 * Event scheduling is always serialized against hlist allocation
5174 * and release. Which makes the protected version suitable here.
5175 * The context lock guarantees that.
5177 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
5178 lockdep_is_held(&event
->ctx
->lock
));
5182 return __find_swevent_head(hlist
, type
, event_id
);
5185 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
5187 struct perf_sample_data
*data
,
5188 struct pt_regs
*regs
)
5190 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5191 struct perf_event
*event
;
5192 struct hlist_node
*node
;
5193 struct hlist_head
*head
;
5196 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
5200 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5201 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
5202 perf_swevent_event(event
, nr
, nmi
, data
, regs
);
5208 int perf_swevent_get_recursion_context(void)
5210 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5212 return get_recursion_context(swhash
->recursion
);
5214 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
5216 inline void perf_swevent_put_recursion_context(int rctx
)
5218 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5220 put_recursion_context(swhash
->recursion
, rctx
);
5223 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
5224 struct pt_regs
*regs
, u64 addr
)
5226 struct perf_sample_data data
;
5229 preempt_disable_notrace();
5230 rctx
= perf_swevent_get_recursion_context();
5234 perf_sample_data_init(&data
, addr
);
5236 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
5238 perf_swevent_put_recursion_context(rctx
);
5239 preempt_enable_notrace();
5242 static void perf_swevent_read(struct perf_event
*event
)
5246 static int perf_swevent_add(struct perf_event
*event
, int flags
)
5248 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5249 struct hw_perf_event
*hwc
= &event
->hw
;
5250 struct hlist_head
*head
;
5252 if (is_sampling_event(event
)) {
5253 hwc
->last_period
= hwc
->sample_period
;
5254 perf_swevent_set_period(event
);
5257 hwc
->state
= !(flags
& PERF_EF_START
);
5259 head
= find_swevent_head(swhash
, event
);
5260 if (WARN_ON_ONCE(!head
))
5263 hlist_add_head_rcu(&event
->hlist_entry
, head
);
5268 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5270 hlist_del_rcu(&event
->hlist_entry
);
5273 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5275 event
->hw
.state
= 0;
5278 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5280 event
->hw
.state
= PERF_HES_STOPPED
;
5283 /* Deref the hlist from the update side */
5284 static inline struct swevent_hlist
*
5285 swevent_hlist_deref(struct swevent_htable
*swhash
)
5287 return rcu_dereference_protected(swhash
->swevent_hlist
,
5288 lockdep_is_held(&swhash
->hlist_mutex
));
5291 static void swevent_hlist_release_rcu(struct rcu_head
*rcu_head
)
5293 struct swevent_hlist
*hlist
;
5295 hlist
= container_of(rcu_head
, struct swevent_hlist
, rcu_head
);
5299 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5301 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5306 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5307 call_rcu(&hlist
->rcu_head
, swevent_hlist_release_rcu
);
5310 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5312 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5314 mutex_lock(&swhash
->hlist_mutex
);
5316 if (!--swhash
->hlist_refcount
)
5317 swevent_hlist_release(swhash
);
5319 mutex_unlock(&swhash
->hlist_mutex
);
5322 static void swevent_hlist_put(struct perf_event
*event
)
5326 if (event
->cpu
!= -1) {
5327 swevent_hlist_put_cpu(event
, event
->cpu
);
5331 for_each_possible_cpu(cpu
)
5332 swevent_hlist_put_cpu(event
, cpu
);
5335 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5337 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5340 mutex_lock(&swhash
->hlist_mutex
);
5342 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5343 struct swevent_hlist
*hlist
;
5345 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5350 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5352 swhash
->hlist_refcount
++;
5354 mutex_unlock(&swhash
->hlist_mutex
);
5359 static int swevent_hlist_get(struct perf_event
*event
)
5362 int cpu
, failed_cpu
;
5364 if (event
->cpu
!= -1)
5365 return swevent_hlist_get_cpu(event
, event
->cpu
);
5368 for_each_possible_cpu(cpu
) {
5369 err
= swevent_hlist_get_cpu(event
, cpu
);
5379 for_each_possible_cpu(cpu
) {
5380 if (cpu
== failed_cpu
)
5382 swevent_hlist_put_cpu(event
, cpu
);
5389 atomic_t perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5391 static void sw_perf_event_destroy(struct perf_event
*event
)
5393 u64 event_id
= event
->attr
.config
;
5395 WARN_ON(event
->parent
);
5397 jump_label_dec(&perf_swevent_enabled
[event_id
]);
5398 swevent_hlist_put(event
);
5401 static int perf_swevent_init(struct perf_event
*event
)
5403 int event_id
= event
->attr
.config
;
5405 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5409 case PERF_COUNT_SW_CPU_CLOCK
:
5410 case PERF_COUNT_SW_TASK_CLOCK
:
5417 if (event_id
>= PERF_COUNT_SW_MAX
)
5420 if (!event
->parent
) {
5423 err
= swevent_hlist_get(event
);
5427 jump_label_inc(&perf_swevent_enabled
[event_id
]);
5428 event
->destroy
= sw_perf_event_destroy
;
5434 static struct pmu perf_swevent
= {
5435 .task_ctx_nr
= perf_sw_context
,
5437 .event_init
= perf_swevent_init
,
5438 .add
= perf_swevent_add
,
5439 .del
= perf_swevent_del
,
5440 .start
= perf_swevent_start
,
5441 .stop
= perf_swevent_stop
,
5442 .read
= perf_swevent_read
,
5445 #ifdef CONFIG_EVENT_TRACING
5447 static int perf_tp_filter_match(struct perf_event
*event
,
5448 struct perf_sample_data
*data
)
5450 void *record
= data
->raw
->data
;
5452 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5457 static int perf_tp_event_match(struct perf_event
*event
,
5458 struct perf_sample_data
*data
,
5459 struct pt_regs
*regs
)
5462 * All tracepoints are from kernel-space.
5464 if (event
->attr
.exclude_kernel
)
5467 if (!perf_tp_filter_match(event
, data
))
5473 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5474 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
5476 struct perf_sample_data data
;
5477 struct perf_event
*event
;
5478 struct hlist_node
*node
;
5480 struct perf_raw_record raw
= {
5485 perf_sample_data_init(&data
, addr
);
5488 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5489 if (perf_tp_event_match(event
, &data
, regs
))
5490 perf_swevent_event(event
, count
, 1, &data
, regs
);
5493 perf_swevent_put_recursion_context(rctx
);
5495 EXPORT_SYMBOL_GPL(perf_tp_event
);
5497 static void tp_perf_event_destroy(struct perf_event
*event
)
5499 perf_trace_destroy(event
);
5502 static int perf_tp_event_init(struct perf_event
*event
)
5506 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5509 err
= perf_trace_init(event
);
5513 event
->destroy
= tp_perf_event_destroy
;
5518 static struct pmu perf_tracepoint
= {
5519 .task_ctx_nr
= perf_sw_context
,
5521 .event_init
= perf_tp_event_init
,
5522 .add
= perf_trace_add
,
5523 .del
= perf_trace_del
,
5524 .start
= perf_swevent_start
,
5525 .stop
= perf_swevent_stop
,
5526 .read
= perf_swevent_read
,
5529 static inline void perf_tp_register(void)
5531 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5534 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5539 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5542 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5543 if (IS_ERR(filter_str
))
5544 return PTR_ERR(filter_str
);
5546 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5552 static void perf_event_free_filter(struct perf_event
*event
)
5554 ftrace_profile_free_filter(event
);
5559 static inline void perf_tp_register(void)
5563 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5568 static void perf_event_free_filter(struct perf_event
*event
)
5572 #endif /* CONFIG_EVENT_TRACING */
5574 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5575 void perf_bp_event(struct perf_event
*bp
, void *data
)
5577 struct perf_sample_data sample
;
5578 struct pt_regs
*regs
= data
;
5580 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
5582 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5583 perf_swevent_event(bp
, 1, 1, &sample
, regs
);
5588 * hrtimer based swevent callback
5591 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5593 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5594 struct perf_sample_data data
;
5595 struct pt_regs
*regs
;
5596 struct perf_event
*event
;
5599 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5600 event
->pmu
->read(event
);
5602 perf_sample_data_init(&data
, 0);
5603 data
.period
= event
->hw
.last_period
;
5604 regs
= get_irq_regs();
5606 if (regs
&& !perf_exclude_event(event
, regs
)) {
5607 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
5608 if (perf_event_overflow(event
, 0, &data
, regs
))
5609 ret
= HRTIMER_NORESTART
;
5612 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5613 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5618 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5620 struct hw_perf_event
*hwc
= &event
->hw
;
5623 if (!is_sampling_event(event
))
5626 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5627 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5629 period
= local64_read(&hwc
->period_left
);
5634 local64_set(&hwc
->period_left
, 0);
5636 period
= max_t(u64
, 10000, hwc
->sample_period
);
5638 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5639 ns_to_ktime(period
), 0,
5640 HRTIMER_MODE_REL_PINNED
, 0);
5643 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5645 struct hw_perf_event
*hwc
= &event
->hw
;
5647 if (is_sampling_event(event
)) {
5648 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5649 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5651 hrtimer_cancel(&hwc
->hrtimer
);
5656 * Software event: cpu wall time clock
5659 static void cpu_clock_event_update(struct perf_event
*event
)
5664 now
= local_clock();
5665 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5666 local64_add(now
- prev
, &event
->count
);
5669 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5671 local64_set(&event
->hw
.prev_count
, local_clock());
5672 perf_swevent_start_hrtimer(event
);
5675 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5677 perf_swevent_cancel_hrtimer(event
);
5678 cpu_clock_event_update(event
);
5681 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5683 if (flags
& PERF_EF_START
)
5684 cpu_clock_event_start(event
, flags
);
5689 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5691 cpu_clock_event_stop(event
, flags
);
5694 static void cpu_clock_event_read(struct perf_event
*event
)
5696 cpu_clock_event_update(event
);
5699 static int cpu_clock_event_init(struct perf_event
*event
)
5701 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5704 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5710 static struct pmu perf_cpu_clock
= {
5711 .task_ctx_nr
= perf_sw_context
,
5713 .event_init
= cpu_clock_event_init
,
5714 .add
= cpu_clock_event_add
,
5715 .del
= cpu_clock_event_del
,
5716 .start
= cpu_clock_event_start
,
5717 .stop
= cpu_clock_event_stop
,
5718 .read
= cpu_clock_event_read
,
5722 * Software event: task time clock
5725 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5730 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5732 local64_add(delta
, &event
->count
);
5735 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5737 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5738 perf_swevent_start_hrtimer(event
);
5741 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5743 perf_swevent_cancel_hrtimer(event
);
5744 task_clock_event_update(event
, event
->ctx
->time
);
5747 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5749 if (flags
& PERF_EF_START
)
5750 task_clock_event_start(event
, flags
);
5755 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5757 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5760 static void task_clock_event_read(struct perf_event
*event
)
5765 update_context_time(event
->ctx
);
5766 update_cgrp_time_from_event(event
);
5767 time
= event
->ctx
->time
;
5769 u64 now
= perf_clock();
5770 u64 delta
= now
- event
->ctx
->timestamp
;
5771 time
= event
->ctx
->time
+ delta
;
5774 task_clock_event_update(event
, time
);
5777 static int task_clock_event_init(struct perf_event
*event
)
5779 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5782 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5788 static struct pmu perf_task_clock
= {
5789 .task_ctx_nr
= perf_sw_context
,
5791 .event_init
= task_clock_event_init
,
5792 .add
= task_clock_event_add
,
5793 .del
= task_clock_event_del
,
5794 .start
= task_clock_event_start
,
5795 .stop
= task_clock_event_stop
,
5796 .read
= task_clock_event_read
,
5799 static void perf_pmu_nop_void(struct pmu
*pmu
)
5803 static int perf_pmu_nop_int(struct pmu
*pmu
)
5808 static void perf_pmu_start_txn(struct pmu
*pmu
)
5810 perf_pmu_disable(pmu
);
5813 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5815 perf_pmu_enable(pmu
);
5819 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5821 perf_pmu_enable(pmu
);
5825 * Ensures all contexts with the same task_ctx_nr have the same
5826 * pmu_cpu_context too.
5828 static void *find_pmu_context(int ctxn
)
5835 list_for_each_entry(pmu
, &pmus
, entry
) {
5836 if (pmu
->task_ctx_nr
== ctxn
)
5837 return pmu
->pmu_cpu_context
;
5843 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5847 for_each_possible_cpu(cpu
) {
5848 struct perf_cpu_context
*cpuctx
;
5850 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5852 if (cpuctx
->active_pmu
== old_pmu
)
5853 cpuctx
->active_pmu
= pmu
;
5857 static void free_pmu_context(struct pmu
*pmu
)
5861 mutex_lock(&pmus_lock
);
5863 * Like a real lame refcount.
5865 list_for_each_entry(i
, &pmus
, entry
) {
5866 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5867 update_pmu_context(i
, pmu
);
5872 free_percpu(pmu
->pmu_cpu_context
);
5874 mutex_unlock(&pmus_lock
);
5876 static struct idr pmu_idr
;
5879 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5881 struct pmu
*pmu
= dev_get_drvdata(dev
);
5883 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5886 static struct device_attribute pmu_dev_attrs
[] = {
5891 static int pmu_bus_running
;
5892 static struct bus_type pmu_bus
= {
5893 .name
= "event_source",
5894 .dev_attrs
= pmu_dev_attrs
,
5897 static void pmu_dev_release(struct device
*dev
)
5902 static int pmu_dev_alloc(struct pmu
*pmu
)
5906 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5910 device_initialize(pmu
->dev
);
5911 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5915 dev_set_drvdata(pmu
->dev
, pmu
);
5916 pmu
->dev
->bus
= &pmu_bus
;
5917 pmu
->dev
->release
= pmu_dev_release
;
5918 ret
= device_add(pmu
->dev
);
5926 put_device(pmu
->dev
);
5930 static struct lock_class_key cpuctx_mutex
;
5932 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5936 mutex_lock(&pmus_lock
);
5938 pmu
->pmu_disable_count
= alloc_percpu(int);
5939 if (!pmu
->pmu_disable_count
)
5948 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
5952 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
5960 if (pmu_bus_running
) {
5961 ret
= pmu_dev_alloc(pmu
);
5967 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
5968 if (pmu
->pmu_cpu_context
)
5969 goto got_cpu_context
;
5971 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
5972 if (!pmu
->pmu_cpu_context
)
5975 for_each_possible_cpu(cpu
) {
5976 struct perf_cpu_context
*cpuctx
;
5978 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5979 __perf_event_init_context(&cpuctx
->ctx
);
5980 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
5981 cpuctx
->ctx
.type
= cpu_context
;
5982 cpuctx
->ctx
.pmu
= pmu
;
5983 cpuctx
->jiffies_interval
= 1;
5984 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
5985 cpuctx
->active_pmu
= pmu
;
5989 if (!pmu
->start_txn
) {
5990 if (pmu
->pmu_enable
) {
5992 * If we have pmu_enable/pmu_disable calls, install
5993 * transaction stubs that use that to try and batch
5994 * hardware accesses.
5996 pmu
->start_txn
= perf_pmu_start_txn
;
5997 pmu
->commit_txn
= perf_pmu_commit_txn
;
5998 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
6000 pmu
->start_txn
= perf_pmu_nop_void
;
6001 pmu
->commit_txn
= perf_pmu_nop_int
;
6002 pmu
->cancel_txn
= perf_pmu_nop_void
;
6006 if (!pmu
->pmu_enable
) {
6007 pmu
->pmu_enable
= perf_pmu_nop_void
;
6008 pmu
->pmu_disable
= perf_pmu_nop_void
;
6011 list_add_rcu(&pmu
->entry
, &pmus
);
6014 mutex_unlock(&pmus_lock
);
6019 device_del(pmu
->dev
);
6020 put_device(pmu
->dev
);
6023 if (pmu
->type
>= PERF_TYPE_MAX
)
6024 idr_remove(&pmu_idr
, pmu
->type
);
6027 free_percpu(pmu
->pmu_disable_count
);
6031 void perf_pmu_unregister(struct pmu
*pmu
)
6033 mutex_lock(&pmus_lock
);
6034 list_del_rcu(&pmu
->entry
);
6035 mutex_unlock(&pmus_lock
);
6038 * We dereference the pmu list under both SRCU and regular RCU, so
6039 * synchronize against both of those.
6041 synchronize_srcu(&pmus_srcu
);
6044 free_percpu(pmu
->pmu_disable_count
);
6045 if (pmu
->type
>= PERF_TYPE_MAX
)
6046 idr_remove(&pmu_idr
, pmu
->type
);
6047 device_del(pmu
->dev
);
6048 put_device(pmu
->dev
);
6049 free_pmu_context(pmu
);
6052 struct pmu
*perf_init_event(struct perf_event
*event
)
6054 struct pmu
*pmu
= NULL
;
6057 idx
= srcu_read_lock(&pmus_srcu
);
6060 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
6065 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6066 int ret
= pmu
->event_init(event
);
6070 if (ret
!= -ENOENT
) {
6075 pmu
= ERR_PTR(-ENOENT
);
6077 srcu_read_unlock(&pmus_srcu
, idx
);
6083 * Allocate and initialize a event structure
6085 static struct perf_event
*
6086 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
6087 struct task_struct
*task
,
6088 struct perf_event
*group_leader
,
6089 struct perf_event
*parent_event
,
6090 perf_overflow_handler_t overflow_handler
)
6093 struct perf_event
*event
;
6094 struct hw_perf_event
*hwc
;
6097 if ((unsigned)cpu
>= nr_cpu_ids
) {
6098 if (!task
|| cpu
!= -1)
6099 return ERR_PTR(-EINVAL
);
6102 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
6104 return ERR_PTR(-ENOMEM
);
6107 * Single events are their own group leaders, with an
6108 * empty sibling list:
6111 group_leader
= event
;
6113 mutex_init(&event
->child_mutex
);
6114 INIT_LIST_HEAD(&event
->child_list
);
6116 INIT_LIST_HEAD(&event
->group_entry
);
6117 INIT_LIST_HEAD(&event
->event_entry
);
6118 INIT_LIST_HEAD(&event
->sibling_list
);
6119 init_waitqueue_head(&event
->waitq
);
6120 init_irq_work(&event
->pending
, perf_pending_event
);
6122 mutex_init(&event
->mmap_mutex
);
6125 event
->attr
= *attr
;
6126 event
->group_leader
= group_leader
;
6130 event
->parent
= parent_event
;
6132 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
6133 event
->id
= atomic64_inc_return(&perf_event_id
);
6135 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6138 event
->attach_state
= PERF_ATTACH_TASK
;
6139 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6141 * hw_breakpoint is a bit difficult here..
6143 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
6144 event
->hw
.bp_target
= task
;
6148 if (!overflow_handler
&& parent_event
)
6149 overflow_handler
= parent_event
->overflow_handler
;
6151 event
->overflow_handler
= overflow_handler
;
6154 event
->state
= PERF_EVENT_STATE_OFF
;
6159 hwc
->sample_period
= attr
->sample_period
;
6160 if (attr
->freq
&& attr
->sample_freq
)
6161 hwc
->sample_period
= 1;
6162 hwc
->last_period
= hwc
->sample_period
;
6164 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6167 * we currently do not support PERF_FORMAT_GROUP on inherited events
6169 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
6172 pmu
= perf_init_event(event
);
6178 else if (IS_ERR(pmu
))
6183 put_pid_ns(event
->ns
);
6185 return ERR_PTR(err
);
6190 if (!event
->parent
) {
6191 if (event
->attach_state
& PERF_ATTACH_TASK
)
6192 jump_label_inc(&perf_sched_events
);
6193 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
6194 atomic_inc(&nr_mmap_events
);
6195 if (event
->attr
.comm
)
6196 atomic_inc(&nr_comm_events
);
6197 if (event
->attr
.task
)
6198 atomic_inc(&nr_task_events
);
6199 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6200 err
= get_callchain_buffers();
6203 return ERR_PTR(err
);
6211 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6212 struct perf_event_attr
*attr
)
6217 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6221 * zero the full structure, so that a short copy will be nice.
6223 memset(attr
, 0, sizeof(*attr
));
6225 ret
= get_user(size
, &uattr
->size
);
6229 if (size
> PAGE_SIZE
) /* silly large */
6232 if (!size
) /* abi compat */
6233 size
= PERF_ATTR_SIZE_VER0
;
6235 if (size
< PERF_ATTR_SIZE_VER0
)
6239 * If we're handed a bigger struct than we know of,
6240 * ensure all the unknown bits are 0 - i.e. new
6241 * user-space does not rely on any kernel feature
6242 * extensions we dont know about yet.
6244 if (size
> sizeof(*attr
)) {
6245 unsigned char __user
*addr
;
6246 unsigned char __user
*end
;
6249 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6250 end
= (void __user
*)uattr
+ size
;
6252 for (; addr
< end
; addr
++) {
6253 ret
= get_user(val
, addr
);
6259 size
= sizeof(*attr
);
6262 ret
= copy_from_user(attr
, uattr
, size
);
6267 * If the type exists, the corresponding creation will verify
6270 if (attr
->type
>= PERF_TYPE_MAX
)
6273 if (attr
->__reserved_1
)
6276 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6279 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6286 put_user(sizeof(*attr
), &uattr
->size
);
6292 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
6294 struct perf_buffer
*buffer
= NULL
, *old_buffer
= NULL
;
6300 /* don't allow circular references */
6301 if (event
== output_event
)
6305 * Don't allow cross-cpu buffers
6307 if (output_event
->cpu
!= event
->cpu
)
6311 * If its not a per-cpu buffer, it must be the same task.
6313 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
6317 mutex_lock(&event
->mmap_mutex
);
6318 /* Can't redirect output if we've got an active mmap() */
6319 if (atomic_read(&event
->mmap_count
))
6323 /* get the buffer we want to redirect to */
6324 buffer
= perf_buffer_get(output_event
);
6329 old_buffer
= event
->buffer
;
6330 rcu_assign_pointer(event
->buffer
, buffer
);
6333 mutex_unlock(&event
->mmap_mutex
);
6336 perf_buffer_put(old_buffer
);
6342 * sys_perf_event_open - open a performance event, associate it to a task/cpu
6344 * @attr_uptr: event_id type attributes for monitoring/sampling
6347 * @group_fd: group leader event fd
6349 SYSCALL_DEFINE5(perf_event_open
,
6350 struct perf_event_attr __user
*, attr_uptr
,
6351 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
6353 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
6354 struct perf_event
*event
, *sibling
;
6355 struct perf_event_attr attr
;
6356 struct perf_event_context
*ctx
;
6357 struct file
*event_file
= NULL
;
6358 struct file
*group_file
= NULL
;
6359 struct task_struct
*task
= NULL
;
6363 int fput_needed
= 0;
6366 /* for future expandability... */
6367 if (flags
& ~PERF_FLAG_ALL
)
6370 err
= perf_copy_attr(attr_uptr
, &attr
);
6374 if (!attr
.exclude_kernel
) {
6375 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6380 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
6385 * In cgroup mode, the pid argument is used to pass the fd
6386 * opened to the cgroup directory in cgroupfs. The cpu argument
6387 * designates the cpu on which to monitor threads from that
6390 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
6393 event_fd
= get_unused_fd_flags(O_RDWR
);
6397 if (group_fd
!= -1) {
6398 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
6399 if (IS_ERR(group_leader
)) {
6400 err
= PTR_ERR(group_leader
);
6403 group_file
= group_leader
->filp
;
6404 if (flags
& PERF_FLAG_FD_OUTPUT
)
6405 output_event
= group_leader
;
6406 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6407 group_leader
= NULL
;
6410 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6411 task
= find_lively_task_by_vpid(pid
);
6413 err
= PTR_ERR(task
);
6418 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
, NULL
);
6419 if (IS_ERR(event
)) {
6420 err
= PTR_ERR(event
);
6424 if (flags
& PERF_FLAG_PID_CGROUP
) {
6425 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6431 * Special case software events and allow them to be part of
6432 * any hardware group.
6437 (is_software_event(event
) != is_software_event(group_leader
))) {
6438 if (is_software_event(event
)) {
6440 * If event and group_leader are not both a software
6441 * event, and event is, then group leader is not.
6443 * Allow the addition of software events to !software
6444 * groups, this is safe because software events never
6447 pmu
= group_leader
->pmu
;
6448 } else if (is_software_event(group_leader
) &&
6449 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6451 * In case the group is a pure software group, and we
6452 * try to add a hardware event, move the whole group to
6453 * the hardware context.
6460 * Get the target context (task or percpu):
6462 ctx
= find_get_context(pmu
, task
, cpu
);
6469 * Look up the group leader (we will attach this event to it):
6475 * Do not allow a recursive hierarchy (this new sibling
6476 * becoming part of another group-sibling):
6478 if (group_leader
->group_leader
!= group_leader
)
6481 * Do not allow to attach to a group in a different
6482 * task or CPU context:
6485 if (group_leader
->ctx
->type
!= ctx
->type
)
6488 if (group_leader
->ctx
!= ctx
)
6493 * Only a group leader can be exclusive or pinned
6495 if (attr
.exclusive
|| attr
.pinned
)
6500 err
= perf_event_set_output(event
, output_event
);
6505 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6506 if (IS_ERR(event_file
)) {
6507 err
= PTR_ERR(event_file
);
6512 struct perf_event_context
*gctx
= group_leader
->ctx
;
6514 mutex_lock(&gctx
->mutex
);
6515 perf_remove_from_context(group_leader
);
6516 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6518 perf_remove_from_context(sibling
);
6521 mutex_unlock(&gctx
->mutex
);
6525 event
->filp
= event_file
;
6526 WARN_ON_ONCE(ctx
->parent_ctx
);
6527 mutex_lock(&ctx
->mutex
);
6530 perf_install_in_context(ctx
, group_leader
, cpu
);
6532 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6534 perf_install_in_context(ctx
, sibling
, cpu
);
6539 perf_install_in_context(ctx
, event
, cpu
);
6541 perf_unpin_context(ctx
);
6542 mutex_unlock(&ctx
->mutex
);
6544 event
->owner
= current
;
6546 mutex_lock(¤t
->perf_event_mutex
);
6547 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6548 mutex_unlock(¤t
->perf_event_mutex
);
6551 * Precalculate sample_data sizes
6553 perf_event__header_size(event
);
6554 perf_event__id_header_size(event
);
6557 * Drop the reference on the group_event after placing the
6558 * new event on the sibling_list. This ensures destruction
6559 * of the group leader will find the pointer to itself in
6560 * perf_group_detach().
6562 fput_light(group_file
, fput_needed
);
6563 fd_install(event_fd
, event_file
);
6567 perf_unpin_context(ctx
);
6573 put_task_struct(task
);
6575 fput_light(group_file
, fput_needed
);
6577 put_unused_fd(event_fd
);
6582 * perf_event_create_kernel_counter
6584 * @attr: attributes of the counter to create
6585 * @cpu: cpu in which the counter is bound
6586 * @task: task to profile (NULL for percpu)
6589 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6590 struct task_struct
*task
,
6591 perf_overflow_handler_t overflow_handler
)
6593 struct perf_event_context
*ctx
;
6594 struct perf_event
*event
;
6598 * Get the target context (task or percpu):
6601 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
, overflow_handler
);
6602 if (IS_ERR(event
)) {
6603 err
= PTR_ERR(event
);
6607 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6614 WARN_ON_ONCE(ctx
->parent_ctx
);
6615 mutex_lock(&ctx
->mutex
);
6616 perf_install_in_context(ctx
, event
, cpu
);
6618 perf_unpin_context(ctx
);
6619 mutex_unlock(&ctx
->mutex
);
6626 return ERR_PTR(err
);
6628 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6630 static void sync_child_event(struct perf_event
*child_event
,
6631 struct task_struct
*child
)
6633 struct perf_event
*parent_event
= child_event
->parent
;
6636 if (child_event
->attr
.inherit_stat
)
6637 perf_event_read_event(child_event
, child
);
6639 child_val
= perf_event_count(child_event
);
6642 * Add back the child's count to the parent's count:
6644 atomic64_add(child_val
, &parent_event
->child_count
);
6645 atomic64_add(child_event
->total_time_enabled
,
6646 &parent_event
->child_total_time_enabled
);
6647 atomic64_add(child_event
->total_time_running
,
6648 &parent_event
->child_total_time_running
);
6651 * Remove this event from the parent's list
6653 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6654 mutex_lock(&parent_event
->child_mutex
);
6655 list_del_init(&child_event
->child_list
);
6656 mutex_unlock(&parent_event
->child_mutex
);
6659 * Release the parent event, if this was the last
6662 fput(parent_event
->filp
);
6666 __perf_event_exit_task(struct perf_event
*child_event
,
6667 struct perf_event_context
*child_ctx
,
6668 struct task_struct
*child
)
6670 struct perf_event
*parent_event
;
6672 perf_remove_from_context(child_event
);
6674 parent_event
= child_event
->parent
;
6676 * It can happen that parent exits first, and has events
6677 * that are still around due to the child reference. These
6678 * events need to be zapped - but otherwise linger.
6681 sync_child_event(child_event
, child
);
6682 free_event(child_event
);
6686 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6688 struct perf_event
*child_event
, *tmp
;
6689 struct perf_event_context
*child_ctx
;
6690 unsigned long flags
;
6692 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6693 perf_event_task(child
, NULL
, 0);
6697 local_irq_save(flags
);
6699 * We can't reschedule here because interrupts are disabled,
6700 * and either child is current or it is a task that can't be
6701 * scheduled, so we are now safe from rescheduling changing
6704 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6705 task_ctx_sched_out(child_ctx
, EVENT_ALL
);
6708 * Take the context lock here so that if find_get_context is
6709 * reading child->perf_event_ctxp, we wait until it has
6710 * incremented the context's refcount before we do put_ctx below.
6712 raw_spin_lock(&child_ctx
->lock
);
6713 child
->perf_event_ctxp
[ctxn
] = NULL
;
6715 * If this context is a clone; unclone it so it can't get
6716 * swapped to another process while we're removing all
6717 * the events from it.
6719 unclone_ctx(child_ctx
);
6720 update_context_time(child_ctx
);
6721 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6724 * Report the task dead after unscheduling the events so that we
6725 * won't get any samples after PERF_RECORD_EXIT. We can however still
6726 * get a few PERF_RECORD_READ events.
6728 perf_event_task(child
, child_ctx
, 0);
6731 * We can recurse on the same lock type through:
6733 * __perf_event_exit_task()
6734 * sync_child_event()
6735 * fput(parent_event->filp)
6737 * mutex_lock(&ctx->mutex)
6739 * But since its the parent context it won't be the same instance.
6741 mutex_lock(&child_ctx
->mutex
);
6744 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6746 __perf_event_exit_task(child_event
, child_ctx
, child
);
6748 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6750 __perf_event_exit_task(child_event
, child_ctx
, child
);
6753 * If the last event was a group event, it will have appended all
6754 * its siblings to the list, but we obtained 'tmp' before that which
6755 * will still point to the list head terminating the iteration.
6757 if (!list_empty(&child_ctx
->pinned_groups
) ||
6758 !list_empty(&child_ctx
->flexible_groups
))
6761 mutex_unlock(&child_ctx
->mutex
);
6767 * When a child task exits, feed back event values to parent events.
6769 void perf_event_exit_task(struct task_struct
*child
)
6771 struct perf_event
*event
, *tmp
;
6774 mutex_lock(&child
->perf_event_mutex
);
6775 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6777 list_del_init(&event
->owner_entry
);
6780 * Ensure the list deletion is visible before we clear
6781 * the owner, closes a race against perf_release() where
6782 * we need to serialize on the owner->perf_event_mutex.
6785 event
->owner
= NULL
;
6787 mutex_unlock(&child
->perf_event_mutex
);
6789 for_each_task_context_nr(ctxn
)
6790 perf_event_exit_task_context(child
, ctxn
);
6793 static void perf_free_event(struct perf_event
*event
,
6794 struct perf_event_context
*ctx
)
6796 struct perf_event
*parent
= event
->parent
;
6798 if (WARN_ON_ONCE(!parent
))
6801 mutex_lock(&parent
->child_mutex
);
6802 list_del_init(&event
->child_list
);
6803 mutex_unlock(&parent
->child_mutex
);
6807 perf_group_detach(event
);
6808 list_del_event(event
, ctx
);
6813 * free an unexposed, unused context as created by inheritance by
6814 * perf_event_init_task below, used by fork() in case of fail.
6816 void perf_event_free_task(struct task_struct
*task
)
6818 struct perf_event_context
*ctx
;
6819 struct perf_event
*event
, *tmp
;
6822 for_each_task_context_nr(ctxn
) {
6823 ctx
= task
->perf_event_ctxp
[ctxn
];
6827 mutex_lock(&ctx
->mutex
);
6829 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6831 perf_free_event(event
, ctx
);
6833 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6835 perf_free_event(event
, ctx
);
6837 if (!list_empty(&ctx
->pinned_groups
) ||
6838 !list_empty(&ctx
->flexible_groups
))
6841 mutex_unlock(&ctx
->mutex
);
6847 void perf_event_delayed_put(struct task_struct
*task
)
6851 for_each_task_context_nr(ctxn
)
6852 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6856 * inherit a event from parent task to child task:
6858 static struct perf_event
*
6859 inherit_event(struct perf_event
*parent_event
,
6860 struct task_struct
*parent
,
6861 struct perf_event_context
*parent_ctx
,
6862 struct task_struct
*child
,
6863 struct perf_event
*group_leader
,
6864 struct perf_event_context
*child_ctx
)
6866 struct perf_event
*child_event
;
6867 unsigned long flags
;
6870 * Instead of creating recursive hierarchies of events,
6871 * we link inherited events back to the original parent,
6872 * which has a filp for sure, which we use as the reference
6875 if (parent_event
->parent
)
6876 parent_event
= parent_event
->parent
;
6878 child_event
= perf_event_alloc(&parent_event
->attr
,
6881 group_leader
, parent_event
,
6883 if (IS_ERR(child_event
))
6888 * Make the child state follow the state of the parent event,
6889 * not its attr.disabled bit. We hold the parent's mutex,
6890 * so we won't race with perf_event_{en, dis}able_family.
6892 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6893 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6895 child_event
->state
= PERF_EVENT_STATE_OFF
;
6897 if (parent_event
->attr
.freq
) {
6898 u64 sample_period
= parent_event
->hw
.sample_period
;
6899 struct hw_perf_event
*hwc
= &child_event
->hw
;
6901 hwc
->sample_period
= sample_period
;
6902 hwc
->last_period
= sample_period
;
6904 local64_set(&hwc
->period_left
, sample_period
);
6907 child_event
->ctx
= child_ctx
;
6908 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6911 * Precalculate sample_data sizes
6913 perf_event__header_size(child_event
);
6914 perf_event__id_header_size(child_event
);
6917 * Link it up in the child's context:
6919 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6920 add_event_to_ctx(child_event
, child_ctx
);
6921 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6924 * Get a reference to the parent filp - we will fput it
6925 * when the child event exits. This is safe to do because
6926 * we are in the parent and we know that the filp still
6927 * exists and has a nonzero count:
6929 atomic_long_inc(&parent_event
->filp
->f_count
);
6932 * Link this into the parent event's child list
6934 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6935 mutex_lock(&parent_event
->child_mutex
);
6936 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
6937 mutex_unlock(&parent_event
->child_mutex
);
6942 static int inherit_group(struct perf_event
*parent_event
,
6943 struct task_struct
*parent
,
6944 struct perf_event_context
*parent_ctx
,
6945 struct task_struct
*child
,
6946 struct perf_event_context
*child_ctx
)
6948 struct perf_event
*leader
;
6949 struct perf_event
*sub
;
6950 struct perf_event
*child_ctr
;
6952 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
6953 child
, NULL
, child_ctx
);
6955 return PTR_ERR(leader
);
6956 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
6957 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
6958 child
, leader
, child_ctx
);
6959 if (IS_ERR(child_ctr
))
6960 return PTR_ERR(child_ctr
);
6966 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
6967 struct perf_event_context
*parent_ctx
,
6968 struct task_struct
*child
, int ctxn
,
6972 struct perf_event_context
*child_ctx
;
6974 if (!event
->attr
.inherit
) {
6979 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6982 * This is executed from the parent task context, so
6983 * inherit events that have been marked for cloning.
6984 * First allocate and initialize a context for the
6988 child_ctx
= alloc_perf_context(event
->pmu
, child
);
6992 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
6995 ret
= inherit_group(event
, parent
, parent_ctx
,
7005 * Initialize the perf_event context in task_struct
7007 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
7009 struct perf_event_context
*child_ctx
, *parent_ctx
;
7010 struct perf_event_context
*cloned_ctx
;
7011 struct perf_event
*event
;
7012 struct task_struct
*parent
= current
;
7013 int inherited_all
= 1;
7014 unsigned long flags
;
7017 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
7021 * If the parent's context is a clone, pin it so it won't get
7024 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
7027 * No need to check if parent_ctx != NULL here; since we saw
7028 * it non-NULL earlier, the only reason for it to become NULL
7029 * is if we exit, and since we're currently in the middle of
7030 * a fork we can't be exiting at the same time.
7034 * Lock the parent list. No need to lock the child - not PID
7035 * hashed yet and not running, so nobody can access it.
7037 mutex_lock(&parent_ctx
->mutex
);
7040 * We dont have to disable NMIs - we are only looking at
7041 * the list, not manipulating it:
7043 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
7044 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7045 child
, ctxn
, &inherited_all
);
7051 * We can't hold ctx->lock when iterating the ->flexible_group list due
7052 * to allocations, but we need to prevent rotation because
7053 * rotate_ctx() will change the list from interrupt context.
7055 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7056 parent_ctx
->rotate_disable
= 1;
7057 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7059 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
7060 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7061 child
, ctxn
, &inherited_all
);
7066 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7067 parent_ctx
->rotate_disable
= 0;
7069 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7071 if (child_ctx
&& inherited_all
) {
7073 * Mark the child context as a clone of the parent
7074 * context, or of whatever the parent is a clone of.
7076 * Note that if the parent is a clone, the holding of
7077 * parent_ctx->lock avoids it from being uncloned.
7079 cloned_ctx
= parent_ctx
->parent_ctx
;
7081 child_ctx
->parent_ctx
= cloned_ctx
;
7082 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
7084 child_ctx
->parent_ctx
= parent_ctx
;
7085 child_ctx
->parent_gen
= parent_ctx
->generation
;
7087 get_ctx(child_ctx
->parent_ctx
);
7090 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7091 mutex_unlock(&parent_ctx
->mutex
);
7093 perf_unpin_context(parent_ctx
);
7094 put_ctx(parent_ctx
);
7100 * Initialize the perf_event context in task_struct
7102 int perf_event_init_task(struct task_struct
*child
)
7106 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7107 mutex_init(&child
->perf_event_mutex
);
7108 INIT_LIST_HEAD(&child
->perf_event_list
);
7110 for_each_task_context_nr(ctxn
) {
7111 ret
= perf_event_init_context(child
, ctxn
);
7119 static void __init
perf_event_init_all_cpus(void)
7121 struct swevent_htable
*swhash
;
7124 for_each_possible_cpu(cpu
) {
7125 swhash
= &per_cpu(swevent_htable
, cpu
);
7126 mutex_init(&swhash
->hlist_mutex
);
7127 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7131 static void __cpuinit
perf_event_init_cpu(int cpu
)
7133 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7135 mutex_lock(&swhash
->hlist_mutex
);
7136 if (swhash
->hlist_refcount
> 0) {
7137 struct swevent_hlist
*hlist
;
7139 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7141 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7143 mutex_unlock(&swhash
->hlist_mutex
);
7146 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7147 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7149 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7151 WARN_ON(!irqs_disabled());
7153 list_del_init(&cpuctx
->rotation_list
);
7156 static void __perf_event_exit_context(void *__info
)
7158 struct perf_event_context
*ctx
= __info
;
7159 struct perf_event
*event
, *tmp
;
7161 perf_pmu_rotate_stop(ctx
->pmu
);
7163 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
7164 __perf_remove_from_context(event
);
7165 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
7166 __perf_remove_from_context(event
);
7169 static void perf_event_exit_cpu_context(int cpu
)
7171 struct perf_event_context
*ctx
;
7175 idx
= srcu_read_lock(&pmus_srcu
);
7176 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7177 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
7179 mutex_lock(&ctx
->mutex
);
7180 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
7181 mutex_unlock(&ctx
->mutex
);
7183 srcu_read_unlock(&pmus_srcu
, idx
);
7186 static void perf_event_exit_cpu(int cpu
)
7188 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7190 mutex_lock(&swhash
->hlist_mutex
);
7191 swevent_hlist_release(swhash
);
7192 mutex_unlock(&swhash
->hlist_mutex
);
7194 perf_event_exit_cpu_context(cpu
);
7197 static inline void perf_event_exit_cpu(int cpu
) { }
7201 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
7205 for_each_online_cpu(cpu
)
7206 perf_event_exit_cpu(cpu
);
7212 * Run the perf reboot notifier at the very last possible moment so that
7213 * the generic watchdog code runs as long as possible.
7215 static struct notifier_block perf_reboot_notifier
= {
7216 .notifier_call
= perf_reboot
,
7217 .priority
= INT_MIN
,
7220 static int __cpuinit
7221 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
7223 unsigned int cpu
= (long)hcpu
;
7225 switch (action
& ~CPU_TASKS_FROZEN
) {
7227 case CPU_UP_PREPARE
:
7228 case CPU_DOWN_FAILED
:
7229 perf_event_init_cpu(cpu
);
7232 case CPU_UP_CANCELED
:
7233 case CPU_DOWN_PREPARE
:
7234 perf_event_exit_cpu(cpu
);
7244 void __init
perf_event_init(void)
7250 perf_event_init_all_cpus();
7251 init_srcu_struct(&pmus_srcu
);
7252 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
7253 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
7254 perf_pmu_register(&perf_task_clock
, NULL
, -1);
7256 perf_cpu_notifier(perf_cpu_notify
);
7257 register_reboot_notifier(&perf_reboot_notifier
);
7259 ret
= init_hw_breakpoint();
7260 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
7263 static int __init
perf_event_sysfs_init(void)
7268 mutex_lock(&pmus_lock
);
7270 ret
= bus_register(&pmu_bus
);
7274 list_for_each_entry(pmu
, &pmus
, entry
) {
7275 if (!pmu
->name
|| pmu
->type
< 0)
7278 ret
= pmu_dev_alloc(pmu
);
7279 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
7281 pmu_bus_running
= 1;
7285 mutex_unlock(&pmus_lock
);
7289 device_initcall(perf_event_sysfs_init
);
7291 #ifdef CONFIG_CGROUP_PERF
7292 static struct cgroup_subsys_state
*perf_cgroup_create(
7293 struct cgroup_subsys
*ss
, struct cgroup
*cont
)
7295 struct perf_cgroup
*jc
;
7296 struct perf_cgroup_info
*t
;
7299 jc
= kmalloc(sizeof(*jc
), GFP_KERNEL
);
7301 return ERR_PTR(-ENOMEM
);
7303 memset(jc
, 0, sizeof(*jc
));
7305 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
7308 return ERR_PTR(-ENOMEM
);
7311 for_each_possible_cpu(c
) {
7312 t
= per_cpu_ptr(jc
->info
, c
);
7319 static void perf_cgroup_destroy(struct cgroup_subsys
*ss
,
7320 struct cgroup
*cont
)
7322 struct perf_cgroup
*jc
;
7323 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
7324 struct perf_cgroup
, css
);
7325 free_percpu(jc
->info
);
7329 static int __perf_cgroup_move(void *info
)
7331 struct task_struct
*task
= info
;
7332 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
7336 static void perf_cgroup_move(struct task_struct
*task
)
7338 task_function_call(task
, __perf_cgroup_move
, task
);
7341 static void perf_cgroup_attach(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
7342 struct cgroup
*old_cgrp
, struct task_struct
*task
,
7345 perf_cgroup_move(task
);
7347 struct task_struct
*c
;
7349 list_for_each_entry_rcu(c
, &task
->thread_group
, thread_group
) {
7350 perf_cgroup_move(c
);
7356 static void perf_cgroup_exit(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
7357 struct cgroup
*old_cgrp
, struct task_struct
*task
)
7360 * cgroup_exit() is called in the copy_process() failure path.
7361 * Ignore this case since the task hasn't ran yet, this avoids
7362 * trying to poke a half freed task state from generic code.
7364 if (!(task
->flags
& PF_EXITING
))
7367 perf_cgroup_move(task
);
7370 struct cgroup_subsys perf_subsys
= {
7371 .name
= "perf_event",
7372 .subsys_id
= perf_subsys_id
,
7373 .create
= perf_cgroup_create
,
7374 .destroy
= perf_cgroup_destroy
,
7375 .exit
= perf_cgroup_exit
,
7376 .attach
= perf_cgroup_attach
,
7378 #endif /* CONFIG_CGROUP_PERF */