2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/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 struct jump_label_key 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 /* Minimum for 512 kiB + 1 user control page */
149 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
152 * max perf event sample rate
154 #define DEFAULT_MAX_SAMPLE_RATE 100000
155 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
156 static int max_samples_per_tick __read_mostly
=
157 DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
159 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
160 void __user
*buffer
, size_t *lenp
,
163 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
168 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
173 static atomic64_t perf_event_id
;
175 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
176 enum event_type_t event_type
);
178 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
179 enum event_type_t event_type
,
180 struct task_struct
*task
);
182 static void update_context_time(struct perf_event_context
*ctx
);
183 static u64
perf_event_time(struct perf_event
*event
);
185 void __weak
perf_event_print_debug(void) { }
187 extern __weak
const char *perf_pmu_name(void)
192 static inline u64
perf_clock(void)
194 return local_clock();
197 static inline struct perf_cpu_context
*
198 __get_cpu_context(struct perf_event_context
*ctx
)
200 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
203 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
204 struct perf_event_context
*ctx
)
206 raw_spin_lock(&cpuctx
->ctx
.lock
);
208 raw_spin_lock(&ctx
->lock
);
211 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
212 struct perf_event_context
*ctx
)
215 raw_spin_unlock(&ctx
->lock
);
216 raw_spin_unlock(&cpuctx
->ctx
.lock
);
219 #ifdef CONFIG_CGROUP_PERF
222 * Must ensure cgroup is pinned (css_get) before calling
223 * this function. In other words, we cannot call this function
224 * if there is no cgroup event for the current CPU context.
226 static inline struct perf_cgroup
*
227 perf_cgroup_from_task(struct task_struct
*task
)
229 return container_of(task_subsys_state(task
, perf_subsys_id
),
230 struct perf_cgroup
, css
);
234 perf_cgroup_match(struct perf_event
*event
)
236 struct perf_event_context
*ctx
= event
->ctx
;
237 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
239 return !event
->cgrp
|| event
->cgrp
== cpuctx
->cgrp
;
242 static inline void perf_get_cgroup(struct perf_event
*event
)
244 css_get(&event
->cgrp
->css
);
247 static inline void perf_put_cgroup(struct perf_event
*event
)
249 css_put(&event
->cgrp
->css
);
252 static inline void perf_detach_cgroup(struct perf_event
*event
)
254 perf_put_cgroup(event
);
258 static inline int is_cgroup_event(struct perf_event
*event
)
260 return event
->cgrp
!= NULL
;
263 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
265 struct perf_cgroup_info
*t
;
267 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
271 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
273 struct perf_cgroup_info
*info
;
278 info
= this_cpu_ptr(cgrp
->info
);
280 info
->time
+= now
- info
->timestamp
;
281 info
->timestamp
= now
;
284 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
286 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
288 __update_cgrp_time(cgrp_out
);
291 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
293 struct perf_cgroup
*cgrp
;
296 * ensure we access cgroup data only when needed and
297 * when we know the cgroup is pinned (css_get)
299 if (!is_cgroup_event(event
))
302 cgrp
= perf_cgroup_from_task(current
);
304 * Do not update time when cgroup is not active
306 if (cgrp
== event
->cgrp
)
307 __update_cgrp_time(event
->cgrp
);
311 perf_cgroup_set_timestamp(struct task_struct
*task
,
312 struct perf_event_context
*ctx
)
314 struct perf_cgroup
*cgrp
;
315 struct perf_cgroup_info
*info
;
318 * ctx->lock held by caller
319 * ensure we do not access cgroup data
320 * unless we have the cgroup pinned (css_get)
322 if (!task
|| !ctx
->nr_cgroups
)
325 cgrp
= perf_cgroup_from_task(task
);
326 info
= this_cpu_ptr(cgrp
->info
);
327 info
->timestamp
= ctx
->timestamp
;
330 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
331 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
334 * reschedule events based on the cgroup constraint of task.
336 * mode SWOUT : schedule out everything
337 * mode SWIN : schedule in based on cgroup for next
339 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
341 struct perf_cpu_context
*cpuctx
;
346 * disable interrupts to avoid geting nr_cgroup
347 * changes via __perf_event_disable(). Also
350 local_irq_save(flags
);
353 * we reschedule only in the presence of cgroup
354 * constrained events.
358 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
359 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
362 * perf_cgroup_events says at least one
363 * context on this CPU has cgroup events.
365 * ctx->nr_cgroups reports the number of cgroup
366 * events for a context.
368 if (cpuctx
->ctx
.nr_cgroups
> 0) {
369 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
370 perf_pmu_disable(cpuctx
->ctx
.pmu
);
372 if (mode
& PERF_CGROUP_SWOUT
) {
373 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
375 * must not be done before ctxswout due
376 * to event_filter_match() in event_sched_out()
381 if (mode
& PERF_CGROUP_SWIN
) {
382 WARN_ON_ONCE(cpuctx
->cgrp
);
383 /* set cgrp before ctxsw in to
384 * allow event_filter_match() to not
385 * have to pass task around
387 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
388 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
390 perf_pmu_enable(cpuctx
->ctx
.pmu
);
391 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
397 local_irq_restore(flags
);
400 static inline void perf_cgroup_sched_out(struct task_struct
*task
)
402 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
405 static inline void perf_cgroup_sched_in(struct task_struct
*task
)
407 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
410 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
411 struct perf_event_attr
*attr
,
412 struct perf_event
*group_leader
)
414 struct perf_cgroup
*cgrp
;
415 struct cgroup_subsys_state
*css
;
417 int ret
= 0, fput_needed
;
419 file
= fget_light(fd
, &fput_needed
);
423 css
= cgroup_css_from_dir(file
, perf_subsys_id
);
429 cgrp
= container_of(css
, struct perf_cgroup
, css
);
432 /* must be done before we fput() the file */
433 perf_get_cgroup(event
);
436 * all events in a group must monitor
437 * the same cgroup because a task belongs
438 * to only one perf cgroup at a time
440 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
441 perf_detach_cgroup(event
);
445 fput_light(file
, fput_needed
);
450 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
452 struct perf_cgroup_info
*t
;
453 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
454 event
->shadow_ctx_time
= now
- t
->timestamp
;
458 perf_cgroup_defer_enabled(struct perf_event
*event
)
461 * when the current task's perf cgroup does not match
462 * the event's, we need to remember to call the
463 * perf_mark_enable() function the first time a task with
464 * a matching perf cgroup is scheduled in.
466 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
467 event
->cgrp_defer_enabled
= 1;
471 perf_cgroup_mark_enabled(struct perf_event
*event
,
472 struct perf_event_context
*ctx
)
474 struct perf_event
*sub
;
475 u64 tstamp
= perf_event_time(event
);
477 if (!event
->cgrp_defer_enabled
)
480 event
->cgrp_defer_enabled
= 0;
482 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
483 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
484 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
485 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
486 sub
->cgrp_defer_enabled
= 0;
490 #else /* !CONFIG_CGROUP_PERF */
493 perf_cgroup_match(struct perf_event
*event
)
498 static inline void perf_detach_cgroup(struct perf_event
*event
)
501 static inline int is_cgroup_event(struct perf_event
*event
)
506 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
511 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
515 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
519 static inline void perf_cgroup_sched_out(struct task_struct
*task
)
523 static inline void perf_cgroup_sched_in(struct task_struct
*task
)
527 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
528 struct perf_event_attr
*attr
,
529 struct perf_event
*group_leader
)
535 perf_cgroup_set_timestamp(struct task_struct
*task
,
536 struct perf_event_context
*ctx
)
541 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
546 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
550 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
556 perf_cgroup_defer_enabled(struct perf_event
*event
)
561 perf_cgroup_mark_enabled(struct perf_event
*event
,
562 struct perf_event_context
*ctx
)
567 void perf_pmu_disable(struct pmu
*pmu
)
569 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
571 pmu
->pmu_disable(pmu
);
574 void perf_pmu_enable(struct pmu
*pmu
)
576 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
578 pmu
->pmu_enable(pmu
);
581 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
584 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
585 * because they're strictly cpu affine and rotate_start is called with IRQs
586 * disabled, while rotate_context is called from IRQ context.
588 static void perf_pmu_rotate_start(struct pmu
*pmu
)
590 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
591 struct list_head
*head
= &__get_cpu_var(rotation_list
);
593 WARN_ON(!irqs_disabled());
595 if (list_empty(&cpuctx
->rotation_list
))
596 list_add(&cpuctx
->rotation_list
, head
);
599 static void get_ctx(struct perf_event_context
*ctx
)
601 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
604 static void put_ctx(struct perf_event_context
*ctx
)
606 if (atomic_dec_and_test(&ctx
->refcount
)) {
608 put_ctx(ctx
->parent_ctx
);
610 put_task_struct(ctx
->task
);
611 kfree_rcu(ctx
, rcu_head
);
615 static void unclone_ctx(struct perf_event_context
*ctx
)
617 if (ctx
->parent_ctx
) {
618 put_ctx(ctx
->parent_ctx
);
619 ctx
->parent_ctx
= NULL
;
623 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
626 * only top level events have the pid namespace they were created in
629 event
= event
->parent
;
631 return task_tgid_nr_ns(p
, event
->ns
);
634 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
637 * only top level events have the pid namespace they were created in
640 event
= event
->parent
;
642 return task_pid_nr_ns(p
, event
->ns
);
646 * If we inherit events we want to return the parent event id
649 static u64
primary_event_id(struct perf_event
*event
)
654 id
= event
->parent
->id
;
660 * Get the perf_event_context for a task and lock it.
661 * This has to cope with with the fact that until it is locked,
662 * the context could get moved to another task.
664 static struct perf_event_context
*
665 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
667 struct perf_event_context
*ctx
;
671 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
674 * If this context is a clone of another, it might
675 * get swapped for another underneath us by
676 * perf_event_task_sched_out, though the
677 * rcu_read_lock() protects us from any context
678 * getting freed. Lock the context and check if it
679 * got swapped before we could get the lock, and retry
680 * if so. If we locked the right context, then it
681 * can't get swapped on us any more.
683 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
684 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
685 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
689 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
690 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
699 * Get the context for a task and increment its pin_count so it
700 * can't get swapped to another task. This also increments its
701 * reference count so that the context can't get freed.
703 static struct perf_event_context
*
704 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
706 struct perf_event_context
*ctx
;
709 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
712 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
717 static void perf_unpin_context(struct perf_event_context
*ctx
)
721 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
723 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
727 * Update the record of the current time in a context.
729 static void update_context_time(struct perf_event_context
*ctx
)
731 u64 now
= perf_clock();
733 ctx
->time
+= now
- ctx
->timestamp
;
734 ctx
->timestamp
= now
;
737 static u64
perf_event_time(struct perf_event
*event
)
739 struct perf_event_context
*ctx
= event
->ctx
;
741 if (is_cgroup_event(event
))
742 return perf_cgroup_event_time(event
);
744 return ctx
? ctx
->time
: 0;
748 * Update the total_time_enabled and total_time_running fields for a event.
750 static void update_event_times(struct perf_event
*event
)
752 struct perf_event_context
*ctx
= event
->ctx
;
755 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
756 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
759 * in cgroup mode, time_enabled represents
760 * the time the event was enabled AND active
761 * tasks were in the monitored cgroup. This is
762 * independent of the activity of the context as
763 * there may be a mix of cgroup and non-cgroup events.
765 * That is why we treat cgroup events differently
768 if (is_cgroup_event(event
))
769 run_end
= perf_event_time(event
);
770 else if (ctx
->is_active
)
773 run_end
= event
->tstamp_stopped
;
775 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
777 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
778 run_end
= event
->tstamp_stopped
;
780 run_end
= perf_event_time(event
);
782 event
->total_time_running
= run_end
- event
->tstamp_running
;
787 * Update total_time_enabled and total_time_running for all events in a group.
789 static void update_group_times(struct perf_event
*leader
)
791 struct perf_event
*event
;
793 update_event_times(leader
);
794 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
795 update_event_times(event
);
798 static struct list_head
*
799 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
801 if (event
->attr
.pinned
)
802 return &ctx
->pinned_groups
;
804 return &ctx
->flexible_groups
;
808 * Add a event from the lists for its context.
809 * Must be called with ctx->mutex and ctx->lock held.
812 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
814 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
815 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
818 * If we're a stand alone event or group leader, we go to the context
819 * list, group events are kept attached to the group so that
820 * perf_group_detach can, at all times, locate all siblings.
822 if (event
->group_leader
== event
) {
823 struct list_head
*list
;
825 if (is_software_event(event
))
826 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
828 list
= ctx_group_list(event
, ctx
);
829 list_add_tail(&event
->group_entry
, list
);
832 if (is_cgroup_event(event
))
835 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
837 perf_pmu_rotate_start(ctx
->pmu
);
839 if (event
->attr
.inherit_stat
)
844 * Called at perf_event creation and when events are attached/detached from a
847 static void perf_event__read_size(struct perf_event
*event
)
849 int entry
= sizeof(u64
); /* value */
853 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
856 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
859 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
860 entry
+= sizeof(u64
);
862 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
863 nr
+= event
->group_leader
->nr_siblings
;
868 event
->read_size
= size
;
871 static void perf_event__header_size(struct perf_event
*event
)
873 struct perf_sample_data
*data
;
874 u64 sample_type
= event
->attr
.sample_type
;
877 perf_event__read_size(event
);
879 if (sample_type
& PERF_SAMPLE_IP
)
880 size
+= sizeof(data
->ip
);
882 if (sample_type
& PERF_SAMPLE_ADDR
)
883 size
+= sizeof(data
->addr
);
885 if (sample_type
& PERF_SAMPLE_PERIOD
)
886 size
+= sizeof(data
->period
);
888 if (sample_type
& PERF_SAMPLE_READ
)
889 size
+= event
->read_size
;
891 event
->header_size
= size
;
894 static void perf_event__id_header_size(struct perf_event
*event
)
896 struct perf_sample_data
*data
;
897 u64 sample_type
= event
->attr
.sample_type
;
900 if (sample_type
& PERF_SAMPLE_TID
)
901 size
+= sizeof(data
->tid_entry
);
903 if (sample_type
& PERF_SAMPLE_TIME
)
904 size
+= sizeof(data
->time
);
906 if (sample_type
& PERF_SAMPLE_ID
)
907 size
+= sizeof(data
->id
);
909 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
910 size
+= sizeof(data
->stream_id
);
912 if (sample_type
& PERF_SAMPLE_CPU
)
913 size
+= sizeof(data
->cpu_entry
);
915 event
->id_header_size
= size
;
918 static void perf_group_attach(struct perf_event
*event
)
920 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
923 * We can have double attach due to group movement in perf_event_open.
925 if (event
->attach_state
& PERF_ATTACH_GROUP
)
928 event
->attach_state
|= PERF_ATTACH_GROUP
;
930 if (group_leader
== event
)
933 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
934 !is_software_event(event
))
935 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
937 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
938 group_leader
->nr_siblings
++;
940 perf_event__header_size(group_leader
);
942 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
943 perf_event__header_size(pos
);
947 * Remove a event from the lists for its context.
948 * Must be called with ctx->mutex and ctx->lock held.
951 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
953 struct perf_cpu_context
*cpuctx
;
955 * We can have double detach due to exit/hot-unplug + close.
957 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
960 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
962 if (is_cgroup_event(event
)) {
964 cpuctx
= __get_cpu_context(ctx
);
966 * if there are no more cgroup events
967 * then cler cgrp to avoid stale pointer
968 * in update_cgrp_time_from_cpuctx()
970 if (!ctx
->nr_cgroups
)
975 if (event
->attr
.inherit_stat
)
978 list_del_rcu(&event
->event_entry
);
980 if (event
->group_leader
== event
)
981 list_del_init(&event
->group_entry
);
983 update_group_times(event
);
986 * If event was in error state, then keep it
987 * that way, otherwise bogus counts will be
988 * returned on read(). The only way to get out
989 * of error state is by explicit re-enabling
992 if (event
->state
> PERF_EVENT_STATE_OFF
)
993 event
->state
= PERF_EVENT_STATE_OFF
;
996 static void perf_group_detach(struct perf_event
*event
)
998 struct perf_event
*sibling
, *tmp
;
999 struct list_head
*list
= NULL
;
1002 * We can have double detach due to exit/hot-unplug + close.
1004 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1007 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1010 * If this is a sibling, remove it from its group.
1012 if (event
->group_leader
!= event
) {
1013 list_del_init(&event
->group_entry
);
1014 event
->group_leader
->nr_siblings
--;
1018 if (!list_empty(&event
->group_entry
))
1019 list
= &event
->group_entry
;
1022 * If this was a group event with sibling events then
1023 * upgrade the siblings to singleton events by adding them
1024 * to whatever list we are on.
1026 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1028 list_move_tail(&sibling
->group_entry
, list
);
1029 sibling
->group_leader
= sibling
;
1031 /* Inherit group flags from the previous leader */
1032 sibling
->group_flags
= event
->group_flags
;
1036 perf_event__header_size(event
->group_leader
);
1038 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1039 perf_event__header_size(tmp
);
1043 event_filter_match(struct perf_event
*event
)
1045 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1046 && perf_cgroup_match(event
);
1050 event_sched_out(struct perf_event
*event
,
1051 struct perf_cpu_context
*cpuctx
,
1052 struct perf_event_context
*ctx
)
1054 u64 tstamp
= perf_event_time(event
);
1057 * An event which could not be activated because of
1058 * filter mismatch still needs to have its timings
1059 * maintained, otherwise bogus information is return
1060 * via read() for time_enabled, time_running:
1062 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1063 && !event_filter_match(event
)) {
1064 delta
= tstamp
- event
->tstamp_stopped
;
1065 event
->tstamp_running
+= delta
;
1066 event
->tstamp_stopped
= tstamp
;
1069 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1072 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1073 if (event
->pending_disable
) {
1074 event
->pending_disable
= 0;
1075 event
->state
= PERF_EVENT_STATE_OFF
;
1077 event
->tstamp_stopped
= tstamp
;
1078 event
->pmu
->del(event
, 0);
1081 if (!is_software_event(event
))
1082 cpuctx
->active_oncpu
--;
1084 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1085 cpuctx
->exclusive
= 0;
1089 group_sched_out(struct perf_event
*group_event
,
1090 struct perf_cpu_context
*cpuctx
,
1091 struct perf_event_context
*ctx
)
1093 struct perf_event
*event
;
1094 int state
= group_event
->state
;
1096 event_sched_out(group_event
, cpuctx
, ctx
);
1099 * Schedule out siblings (if any):
1101 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1102 event_sched_out(event
, cpuctx
, ctx
);
1104 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1105 cpuctx
->exclusive
= 0;
1109 * Cross CPU call to remove a performance event
1111 * We disable the event on the hardware level first. After that we
1112 * remove it from the context list.
1114 static int __perf_remove_from_context(void *info
)
1116 struct perf_event
*event
= info
;
1117 struct perf_event_context
*ctx
= event
->ctx
;
1118 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1120 raw_spin_lock(&ctx
->lock
);
1121 event_sched_out(event
, cpuctx
, ctx
);
1122 list_del_event(event
, ctx
);
1123 raw_spin_unlock(&ctx
->lock
);
1130 * Remove the event from a task's (or a CPU's) list of events.
1132 * CPU events are removed with a smp call. For task events we only
1133 * call when the task is on a CPU.
1135 * If event->ctx is a cloned context, callers must make sure that
1136 * every task struct that event->ctx->task could possibly point to
1137 * remains valid. This is OK when called from perf_release since
1138 * that only calls us on the top-level context, which can't be a clone.
1139 * When called from perf_event_exit_task, it's OK because the
1140 * context has been detached from its task.
1142 static void perf_remove_from_context(struct perf_event
*event
)
1144 struct perf_event_context
*ctx
= event
->ctx
;
1145 struct task_struct
*task
= ctx
->task
;
1147 lockdep_assert_held(&ctx
->mutex
);
1151 * Per cpu events are removed via an smp call and
1152 * the removal is always successful.
1154 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1159 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1162 raw_spin_lock_irq(&ctx
->lock
);
1164 * If we failed to find a running task, but find the context active now
1165 * that we've acquired the ctx->lock, retry.
1167 if (ctx
->is_active
) {
1168 raw_spin_unlock_irq(&ctx
->lock
);
1173 * Since the task isn't running, its safe to remove the event, us
1174 * holding the ctx->lock ensures the task won't get scheduled in.
1176 list_del_event(event
, ctx
);
1177 raw_spin_unlock_irq(&ctx
->lock
);
1181 * Cross CPU call to disable a performance event
1183 static int __perf_event_disable(void *info
)
1185 struct perf_event
*event
= info
;
1186 struct perf_event_context
*ctx
= event
->ctx
;
1187 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1190 * If this is a per-task event, need to check whether this
1191 * event's task is the current task on this cpu.
1193 * Can trigger due to concurrent perf_event_context_sched_out()
1194 * flipping contexts around.
1196 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1199 raw_spin_lock(&ctx
->lock
);
1202 * If the event is on, turn it off.
1203 * If it is in error state, leave it in error state.
1205 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1206 update_context_time(ctx
);
1207 update_cgrp_time_from_event(event
);
1208 update_group_times(event
);
1209 if (event
== event
->group_leader
)
1210 group_sched_out(event
, cpuctx
, ctx
);
1212 event_sched_out(event
, cpuctx
, ctx
);
1213 event
->state
= PERF_EVENT_STATE_OFF
;
1216 raw_spin_unlock(&ctx
->lock
);
1224 * If event->ctx is a cloned context, callers must make sure that
1225 * every task struct that event->ctx->task could possibly point to
1226 * remains valid. This condition is satisifed when called through
1227 * perf_event_for_each_child or perf_event_for_each because they
1228 * hold the top-level event's child_mutex, so any descendant that
1229 * goes to exit will block in sync_child_event.
1230 * When called from perf_pending_event it's OK because event->ctx
1231 * is the current context on this CPU and preemption is disabled,
1232 * hence we can't get into perf_event_task_sched_out for this context.
1234 void perf_event_disable(struct perf_event
*event
)
1236 struct perf_event_context
*ctx
= event
->ctx
;
1237 struct task_struct
*task
= ctx
->task
;
1241 * Disable the event on the cpu that it's on
1243 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1248 if (!task_function_call(task
, __perf_event_disable
, event
))
1251 raw_spin_lock_irq(&ctx
->lock
);
1253 * If the event is still active, we need to retry the cross-call.
1255 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1256 raw_spin_unlock_irq(&ctx
->lock
);
1258 * Reload the task pointer, it might have been changed by
1259 * a concurrent perf_event_context_sched_out().
1266 * Since we have the lock this context can't be scheduled
1267 * in, so we can change the state safely.
1269 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1270 update_group_times(event
);
1271 event
->state
= PERF_EVENT_STATE_OFF
;
1273 raw_spin_unlock_irq(&ctx
->lock
);
1276 static void perf_set_shadow_time(struct perf_event
*event
,
1277 struct perf_event_context
*ctx
,
1281 * use the correct time source for the time snapshot
1283 * We could get by without this by leveraging the
1284 * fact that to get to this function, the caller
1285 * has most likely already called update_context_time()
1286 * and update_cgrp_time_xx() and thus both timestamp
1287 * are identical (or very close). Given that tstamp is,
1288 * already adjusted for cgroup, we could say that:
1289 * tstamp - ctx->timestamp
1291 * tstamp - cgrp->timestamp.
1293 * Then, in perf_output_read(), the calculation would
1294 * work with no changes because:
1295 * - event is guaranteed scheduled in
1296 * - no scheduled out in between
1297 * - thus the timestamp would be the same
1299 * But this is a bit hairy.
1301 * So instead, we have an explicit cgroup call to remain
1302 * within the time time source all along. We believe it
1303 * is cleaner and simpler to understand.
1305 if (is_cgroup_event(event
))
1306 perf_cgroup_set_shadow_time(event
, tstamp
);
1308 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1311 #define MAX_INTERRUPTS (~0ULL)
1313 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1316 event_sched_in(struct perf_event
*event
,
1317 struct perf_cpu_context
*cpuctx
,
1318 struct perf_event_context
*ctx
)
1320 u64 tstamp
= perf_event_time(event
);
1322 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1325 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1326 event
->oncpu
= smp_processor_id();
1329 * Unthrottle events, since we scheduled we might have missed several
1330 * ticks already, also for a heavily scheduling task there is little
1331 * guarantee it'll get a tick in a timely manner.
1333 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1334 perf_log_throttle(event
, 1);
1335 event
->hw
.interrupts
= 0;
1339 * The new state must be visible before we turn it on in the hardware:
1343 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1344 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1349 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1351 perf_set_shadow_time(event
, ctx
, tstamp
);
1353 if (!is_software_event(event
))
1354 cpuctx
->active_oncpu
++;
1357 if (event
->attr
.exclusive
)
1358 cpuctx
->exclusive
= 1;
1364 group_sched_in(struct perf_event
*group_event
,
1365 struct perf_cpu_context
*cpuctx
,
1366 struct perf_event_context
*ctx
)
1368 struct perf_event
*event
, *partial_group
= NULL
;
1369 struct pmu
*pmu
= group_event
->pmu
;
1370 u64 now
= ctx
->time
;
1371 bool simulate
= false;
1373 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1376 pmu
->start_txn(pmu
);
1378 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1379 pmu
->cancel_txn(pmu
);
1384 * Schedule in siblings as one group (if any):
1386 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1387 if (event_sched_in(event
, cpuctx
, ctx
)) {
1388 partial_group
= event
;
1393 if (!pmu
->commit_txn(pmu
))
1398 * Groups can be scheduled in as one unit only, so undo any
1399 * partial group before returning:
1400 * The events up to the failed event are scheduled out normally,
1401 * tstamp_stopped will be updated.
1403 * The failed events and the remaining siblings need to have
1404 * their timings updated as if they had gone thru event_sched_in()
1405 * and event_sched_out(). This is required to get consistent timings
1406 * across the group. This also takes care of the case where the group
1407 * could never be scheduled by ensuring tstamp_stopped is set to mark
1408 * the time the event was actually stopped, such that time delta
1409 * calculation in update_event_times() is correct.
1411 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1412 if (event
== partial_group
)
1416 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1417 event
->tstamp_stopped
= now
;
1419 event_sched_out(event
, cpuctx
, ctx
);
1422 event_sched_out(group_event
, cpuctx
, ctx
);
1424 pmu
->cancel_txn(pmu
);
1430 * Work out whether we can put this event group on the CPU now.
1432 static int group_can_go_on(struct perf_event
*event
,
1433 struct perf_cpu_context
*cpuctx
,
1437 * Groups consisting entirely of software events can always go on.
1439 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1442 * If an exclusive group is already on, no other hardware
1445 if (cpuctx
->exclusive
)
1448 * If this group is exclusive and there are already
1449 * events on the CPU, it can't go on.
1451 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1454 * Otherwise, try to add it if all previous groups were able
1460 static void add_event_to_ctx(struct perf_event
*event
,
1461 struct perf_event_context
*ctx
)
1463 u64 tstamp
= perf_event_time(event
);
1465 list_add_event(event
, ctx
);
1466 perf_group_attach(event
);
1467 event
->tstamp_enabled
= tstamp
;
1468 event
->tstamp_running
= tstamp
;
1469 event
->tstamp_stopped
= tstamp
;
1472 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
1474 ctx_sched_in(struct perf_event_context
*ctx
,
1475 struct perf_cpu_context
*cpuctx
,
1476 enum event_type_t event_type
,
1477 struct task_struct
*task
);
1479 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
1480 struct perf_event_context
*ctx
,
1481 struct task_struct
*task
)
1483 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
1485 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
1486 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
1488 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
1492 * Cross CPU call to install and enable a performance event
1494 * Must be called with ctx->mutex held
1496 static int __perf_install_in_context(void *info
)
1498 struct perf_event
*event
= info
;
1499 struct perf_event_context
*ctx
= event
->ctx
;
1500 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1501 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
1502 struct task_struct
*task
= current
;
1504 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
1505 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1508 * If there was an active task_ctx schedule it out.
1511 task_ctx_sched_out(task_ctx
);
1513 * If the context we're installing events in is not the
1514 * active task_ctx, flip them.
1516 if (ctx
->task
&& task_ctx
!= ctx
) {
1517 raw_spin_unlock(&cpuctx
->ctx
.lock
);
1518 raw_spin_lock(&ctx
->lock
);
1519 cpuctx
->task_ctx
= task_ctx
= ctx
;
1521 task
= task_ctx
->task
;
1523 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
1525 update_context_time(ctx
);
1527 * update cgrp time only if current cgrp
1528 * matches event->cgrp. Must be done before
1529 * calling add_event_to_ctx()
1531 update_cgrp_time_from_event(event
);
1533 add_event_to_ctx(event
, ctx
);
1536 * Schedule everything back in
1538 perf_event_sched_in(cpuctx
, task_ctx
, task
);
1540 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1541 perf_ctx_unlock(cpuctx
, task_ctx
);
1547 * Attach a performance event to a context
1549 * First we add the event to the list with the hardware enable bit
1550 * in event->hw_config cleared.
1552 * If the event is attached to a task which is on a CPU we use a smp
1553 * call to enable it in the task context. The task might have been
1554 * scheduled away, but we check this in the smp call again.
1557 perf_install_in_context(struct perf_event_context
*ctx
,
1558 struct perf_event
*event
,
1561 struct task_struct
*task
= ctx
->task
;
1563 lockdep_assert_held(&ctx
->mutex
);
1569 * Per cpu events are installed via an smp call and
1570 * the install is always successful.
1572 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1577 if (!task_function_call(task
, __perf_install_in_context
, event
))
1580 raw_spin_lock_irq(&ctx
->lock
);
1582 * If we failed to find a running task, but find the context active now
1583 * that we've acquired the ctx->lock, retry.
1585 if (ctx
->is_active
) {
1586 raw_spin_unlock_irq(&ctx
->lock
);
1591 * Since the task isn't running, its safe to add the event, us holding
1592 * the ctx->lock ensures the task won't get scheduled in.
1594 add_event_to_ctx(event
, ctx
);
1595 raw_spin_unlock_irq(&ctx
->lock
);
1599 * Put a event into inactive state and update time fields.
1600 * Enabling the leader of a group effectively enables all
1601 * the group members that aren't explicitly disabled, so we
1602 * have to update their ->tstamp_enabled also.
1603 * Note: this works for group members as well as group leaders
1604 * since the non-leader members' sibling_lists will be empty.
1606 static void __perf_event_mark_enabled(struct perf_event
*event
,
1607 struct perf_event_context
*ctx
)
1609 struct perf_event
*sub
;
1610 u64 tstamp
= perf_event_time(event
);
1612 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1613 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1614 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1615 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1616 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1621 * Cross CPU call to enable a performance event
1623 static int __perf_event_enable(void *info
)
1625 struct perf_event
*event
= info
;
1626 struct perf_event_context
*ctx
= event
->ctx
;
1627 struct perf_event
*leader
= event
->group_leader
;
1628 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1631 if (WARN_ON_ONCE(!ctx
->is_active
))
1634 raw_spin_lock(&ctx
->lock
);
1635 update_context_time(ctx
);
1637 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1641 * set current task's cgroup time reference point
1643 perf_cgroup_set_timestamp(current
, ctx
);
1645 __perf_event_mark_enabled(event
, ctx
);
1647 if (!event_filter_match(event
)) {
1648 if (is_cgroup_event(event
))
1649 perf_cgroup_defer_enabled(event
);
1654 * If the event is in a group and isn't the group leader,
1655 * then don't put it on unless the group is on.
1657 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1660 if (!group_can_go_on(event
, cpuctx
, 1)) {
1663 if (event
== leader
)
1664 err
= group_sched_in(event
, cpuctx
, ctx
);
1666 err
= event_sched_in(event
, cpuctx
, ctx
);
1671 * If this event can't go on and it's part of a
1672 * group, then the whole group has to come off.
1674 if (leader
!= event
)
1675 group_sched_out(leader
, cpuctx
, ctx
);
1676 if (leader
->attr
.pinned
) {
1677 update_group_times(leader
);
1678 leader
->state
= PERF_EVENT_STATE_ERROR
;
1683 raw_spin_unlock(&ctx
->lock
);
1691 * If event->ctx is a cloned context, callers must make sure that
1692 * every task struct that event->ctx->task could possibly point to
1693 * remains valid. This condition is satisfied when called through
1694 * perf_event_for_each_child or perf_event_for_each as described
1695 * for perf_event_disable.
1697 void perf_event_enable(struct perf_event
*event
)
1699 struct perf_event_context
*ctx
= event
->ctx
;
1700 struct task_struct
*task
= ctx
->task
;
1704 * Enable the event on the cpu that it's on
1706 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
1710 raw_spin_lock_irq(&ctx
->lock
);
1711 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1715 * If the event is in error state, clear that first.
1716 * That way, if we see the event in error state below, we
1717 * know that it has gone back into error state, as distinct
1718 * from the task having been scheduled away before the
1719 * cross-call arrived.
1721 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1722 event
->state
= PERF_EVENT_STATE_OFF
;
1725 if (!ctx
->is_active
) {
1726 __perf_event_mark_enabled(event
, ctx
);
1730 raw_spin_unlock_irq(&ctx
->lock
);
1732 if (!task_function_call(task
, __perf_event_enable
, event
))
1735 raw_spin_lock_irq(&ctx
->lock
);
1738 * If the context is active and the event is still off,
1739 * we need to retry the cross-call.
1741 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
1743 * task could have been flipped by a concurrent
1744 * perf_event_context_sched_out()
1751 raw_spin_unlock_irq(&ctx
->lock
);
1754 static int perf_event_refresh(struct perf_event
*event
, int refresh
)
1757 * not supported on inherited events
1759 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1762 atomic_add(refresh
, &event
->event_limit
);
1763 perf_event_enable(event
);
1768 static void ctx_sched_out(struct perf_event_context
*ctx
,
1769 struct perf_cpu_context
*cpuctx
,
1770 enum event_type_t event_type
)
1772 struct perf_event
*event
;
1773 int is_active
= ctx
->is_active
;
1775 ctx
->is_active
&= ~event_type
;
1776 if (likely(!ctx
->nr_events
))
1779 update_context_time(ctx
);
1780 update_cgrp_time_from_cpuctx(cpuctx
);
1781 if (!ctx
->nr_active
)
1784 perf_pmu_disable(ctx
->pmu
);
1785 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
1786 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1787 group_sched_out(event
, cpuctx
, ctx
);
1790 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
1791 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1792 group_sched_out(event
, cpuctx
, ctx
);
1794 perf_pmu_enable(ctx
->pmu
);
1798 * Test whether two contexts are equivalent, i.e. whether they
1799 * have both been cloned from the same version of the same context
1800 * and they both have the same number of enabled events.
1801 * If the number of enabled events is the same, then the set
1802 * of enabled events should be the same, because these are both
1803 * inherited contexts, therefore we can't access individual events
1804 * in them directly with an fd; we can only enable/disable all
1805 * events via prctl, or enable/disable all events in a family
1806 * via ioctl, which will have the same effect on both contexts.
1808 static int context_equiv(struct perf_event_context
*ctx1
,
1809 struct perf_event_context
*ctx2
)
1811 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1812 && ctx1
->parent_gen
== ctx2
->parent_gen
1813 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1816 static void __perf_event_sync_stat(struct perf_event
*event
,
1817 struct perf_event
*next_event
)
1821 if (!event
->attr
.inherit_stat
)
1825 * Update the event value, we cannot use perf_event_read()
1826 * because we're in the middle of a context switch and have IRQs
1827 * disabled, which upsets smp_call_function_single(), however
1828 * we know the event must be on the current CPU, therefore we
1829 * don't need to use it.
1831 switch (event
->state
) {
1832 case PERF_EVENT_STATE_ACTIVE
:
1833 event
->pmu
->read(event
);
1836 case PERF_EVENT_STATE_INACTIVE
:
1837 update_event_times(event
);
1845 * In order to keep per-task stats reliable we need to flip the event
1846 * values when we flip the contexts.
1848 value
= local64_read(&next_event
->count
);
1849 value
= local64_xchg(&event
->count
, value
);
1850 local64_set(&next_event
->count
, value
);
1852 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1853 swap(event
->total_time_running
, next_event
->total_time_running
);
1856 * Since we swizzled the values, update the user visible data too.
1858 perf_event_update_userpage(event
);
1859 perf_event_update_userpage(next_event
);
1862 #define list_next_entry(pos, member) \
1863 list_entry(pos->member.next, typeof(*pos), member)
1865 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1866 struct perf_event_context
*next_ctx
)
1868 struct perf_event
*event
, *next_event
;
1873 update_context_time(ctx
);
1875 event
= list_first_entry(&ctx
->event_list
,
1876 struct perf_event
, event_entry
);
1878 next_event
= list_first_entry(&next_ctx
->event_list
,
1879 struct perf_event
, event_entry
);
1881 while (&event
->event_entry
!= &ctx
->event_list
&&
1882 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1884 __perf_event_sync_stat(event
, next_event
);
1886 event
= list_next_entry(event
, event_entry
);
1887 next_event
= list_next_entry(next_event
, event_entry
);
1891 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
1892 struct task_struct
*next
)
1894 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
1895 struct perf_event_context
*next_ctx
;
1896 struct perf_event_context
*parent
;
1897 struct perf_cpu_context
*cpuctx
;
1903 cpuctx
= __get_cpu_context(ctx
);
1904 if (!cpuctx
->task_ctx
)
1908 parent
= rcu_dereference(ctx
->parent_ctx
);
1909 next_ctx
= next
->perf_event_ctxp
[ctxn
];
1910 if (parent
&& next_ctx
&&
1911 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1913 * Looks like the two contexts are clones, so we might be
1914 * able to optimize the context switch. We lock both
1915 * contexts and check that they are clones under the
1916 * lock (including re-checking that neither has been
1917 * uncloned in the meantime). It doesn't matter which
1918 * order we take the locks because no other cpu could
1919 * be trying to lock both of these tasks.
1921 raw_spin_lock(&ctx
->lock
);
1922 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1923 if (context_equiv(ctx
, next_ctx
)) {
1925 * XXX do we need a memory barrier of sorts
1926 * wrt to rcu_dereference() of perf_event_ctxp
1928 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
1929 next
->perf_event_ctxp
[ctxn
] = ctx
;
1931 next_ctx
->task
= task
;
1934 perf_event_sync_stat(ctx
, next_ctx
);
1936 raw_spin_unlock(&next_ctx
->lock
);
1937 raw_spin_unlock(&ctx
->lock
);
1942 raw_spin_lock(&ctx
->lock
);
1943 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1944 cpuctx
->task_ctx
= NULL
;
1945 raw_spin_unlock(&ctx
->lock
);
1949 #define for_each_task_context_nr(ctxn) \
1950 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
1953 * Called from scheduler to remove the events of the current task,
1954 * with interrupts disabled.
1956 * We stop each event and update the event value in event->count.
1958 * This does not protect us against NMI, but disable()
1959 * sets the disabled bit in the control field of event _before_
1960 * accessing the event control register. If a NMI hits, then it will
1961 * not restart the event.
1963 void __perf_event_task_sched_out(struct task_struct
*task
,
1964 struct task_struct
*next
)
1968 for_each_task_context_nr(ctxn
)
1969 perf_event_context_sched_out(task
, ctxn
, next
);
1972 * if cgroup events exist on this CPU, then we need
1973 * to check if we have to switch out PMU state.
1974 * cgroup event are system-wide mode only
1976 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
1977 perf_cgroup_sched_out(task
);
1980 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
1982 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1984 if (!cpuctx
->task_ctx
)
1987 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
1990 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
1991 cpuctx
->task_ctx
= NULL
;
1995 * Called with IRQs disabled
1997 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
1998 enum event_type_t event_type
)
2000 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2004 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2005 struct perf_cpu_context
*cpuctx
)
2007 struct perf_event
*event
;
2009 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2010 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2012 if (!event_filter_match(event
))
2015 /* may need to reset tstamp_enabled */
2016 if (is_cgroup_event(event
))
2017 perf_cgroup_mark_enabled(event
, ctx
);
2019 if (group_can_go_on(event
, cpuctx
, 1))
2020 group_sched_in(event
, cpuctx
, ctx
);
2023 * If this pinned group hasn't been scheduled,
2024 * put it in error state.
2026 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2027 update_group_times(event
);
2028 event
->state
= PERF_EVENT_STATE_ERROR
;
2034 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2035 struct perf_cpu_context
*cpuctx
)
2037 struct perf_event
*event
;
2040 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2041 /* Ignore events in OFF or ERROR state */
2042 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2045 * Listen to the 'cpu' scheduling filter constraint
2048 if (!event_filter_match(event
))
2051 /* may need to reset tstamp_enabled */
2052 if (is_cgroup_event(event
))
2053 perf_cgroup_mark_enabled(event
, ctx
);
2055 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2056 if (group_sched_in(event
, cpuctx
, ctx
))
2063 ctx_sched_in(struct perf_event_context
*ctx
,
2064 struct perf_cpu_context
*cpuctx
,
2065 enum event_type_t event_type
,
2066 struct task_struct
*task
)
2069 int is_active
= ctx
->is_active
;
2071 ctx
->is_active
|= event_type
;
2072 if (likely(!ctx
->nr_events
))
2076 ctx
->timestamp
= now
;
2077 perf_cgroup_set_timestamp(task
, ctx
);
2079 * First go through the list and put on any pinned groups
2080 * in order to give them the best chance of going on.
2082 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2083 ctx_pinned_sched_in(ctx
, cpuctx
);
2085 /* Then walk through the lower prio flexible groups */
2086 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2087 ctx_flexible_sched_in(ctx
, cpuctx
);
2090 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2091 enum event_type_t event_type
,
2092 struct task_struct
*task
)
2094 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2096 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2099 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2100 struct task_struct
*task
)
2102 struct perf_cpu_context
*cpuctx
;
2104 cpuctx
= __get_cpu_context(ctx
);
2105 if (cpuctx
->task_ctx
== ctx
)
2108 perf_ctx_lock(cpuctx
, ctx
);
2109 perf_pmu_disable(ctx
->pmu
);
2111 * We want to keep the following priority order:
2112 * cpu pinned (that don't need to move), task pinned,
2113 * cpu flexible, task flexible.
2115 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2117 perf_event_sched_in(cpuctx
, ctx
, task
);
2119 cpuctx
->task_ctx
= ctx
;
2121 perf_pmu_enable(ctx
->pmu
);
2122 perf_ctx_unlock(cpuctx
, ctx
);
2125 * Since these rotations are per-cpu, we need to ensure the
2126 * cpu-context we got scheduled on is actually rotating.
2128 perf_pmu_rotate_start(ctx
->pmu
);
2132 * Called from scheduler to add the events of the current task
2133 * with interrupts disabled.
2135 * We restore the event value and then enable it.
2137 * This does not protect us against NMI, but enable()
2138 * sets the enabled bit in the control field of event _before_
2139 * accessing the event control register. If a NMI hits, then it will
2140 * keep the event running.
2142 void __perf_event_task_sched_in(struct task_struct
*task
)
2144 struct perf_event_context
*ctx
;
2147 for_each_task_context_nr(ctxn
) {
2148 ctx
= task
->perf_event_ctxp
[ctxn
];
2152 perf_event_context_sched_in(ctx
, task
);
2155 * if cgroup events exist on this CPU, then we need
2156 * to check if we have to switch in PMU state.
2157 * cgroup event are system-wide mode only
2159 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2160 perf_cgroup_sched_in(task
);
2163 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2165 u64 frequency
= event
->attr
.sample_freq
;
2166 u64 sec
= NSEC_PER_SEC
;
2167 u64 divisor
, dividend
;
2169 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2171 count_fls
= fls64(count
);
2172 nsec_fls
= fls64(nsec
);
2173 frequency_fls
= fls64(frequency
);
2177 * We got @count in @nsec, with a target of sample_freq HZ
2178 * the target period becomes:
2181 * period = -------------------
2182 * @nsec * sample_freq
2187 * Reduce accuracy by one bit such that @a and @b converge
2188 * to a similar magnitude.
2190 #define REDUCE_FLS(a, b) \
2192 if (a##_fls > b##_fls) { \
2202 * Reduce accuracy until either term fits in a u64, then proceed with
2203 * the other, so that finally we can do a u64/u64 division.
2205 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2206 REDUCE_FLS(nsec
, frequency
);
2207 REDUCE_FLS(sec
, count
);
2210 if (count_fls
+ sec_fls
> 64) {
2211 divisor
= nsec
* frequency
;
2213 while (count_fls
+ sec_fls
> 64) {
2214 REDUCE_FLS(count
, sec
);
2218 dividend
= count
* sec
;
2220 dividend
= count
* sec
;
2222 while (nsec_fls
+ frequency_fls
> 64) {
2223 REDUCE_FLS(nsec
, frequency
);
2227 divisor
= nsec
* frequency
;
2233 return div64_u64(dividend
, divisor
);
2236 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2238 struct hw_perf_event
*hwc
= &event
->hw
;
2239 s64 period
, sample_period
;
2242 period
= perf_calculate_period(event
, nsec
, count
);
2244 delta
= (s64
)(period
- hwc
->sample_period
);
2245 delta
= (delta
+ 7) / 8; /* low pass filter */
2247 sample_period
= hwc
->sample_period
+ delta
;
2252 hwc
->sample_period
= sample_period
;
2254 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2255 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2256 local64_set(&hwc
->period_left
, 0);
2257 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2261 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
, u64 period
)
2263 struct perf_event
*event
;
2264 struct hw_perf_event
*hwc
;
2265 u64 interrupts
, now
;
2268 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2269 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2272 if (!event_filter_match(event
))
2277 interrupts
= hwc
->interrupts
;
2278 hwc
->interrupts
= 0;
2281 * unthrottle events on the tick
2283 if (interrupts
== MAX_INTERRUPTS
) {
2284 perf_log_throttle(event
, 1);
2285 event
->pmu
->start(event
, 0);
2288 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2291 event
->pmu
->read(event
);
2292 now
= local64_read(&event
->count
);
2293 delta
= now
- hwc
->freq_count_stamp
;
2294 hwc
->freq_count_stamp
= now
;
2297 perf_adjust_period(event
, period
, delta
);
2302 * Round-robin a context's events:
2304 static void rotate_ctx(struct perf_event_context
*ctx
)
2307 * Rotate the first entry last of non-pinned groups. Rotation might be
2308 * disabled by the inheritance code.
2310 if (!ctx
->rotate_disable
)
2311 list_rotate_left(&ctx
->flexible_groups
);
2315 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2316 * because they're strictly cpu affine and rotate_start is called with IRQs
2317 * disabled, while rotate_context is called from IRQ context.
2319 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2321 u64 interval
= (u64
)cpuctx
->jiffies_interval
* TICK_NSEC
;
2322 struct perf_event_context
*ctx
= NULL
;
2323 int rotate
= 0, remove
= 1;
2325 if (cpuctx
->ctx
.nr_events
) {
2327 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2331 ctx
= cpuctx
->task_ctx
;
2332 if (ctx
&& ctx
->nr_events
) {
2334 if (ctx
->nr_events
!= ctx
->nr_active
)
2338 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2339 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2340 perf_ctx_adjust_freq(&cpuctx
->ctx
, interval
);
2342 perf_ctx_adjust_freq(ctx
, interval
);
2347 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2349 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
2351 rotate_ctx(&cpuctx
->ctx
);
2355 perf_event_sched_in(cpuctx
, ctx
, current
);
2359 list_del_init(&cpuctx
->rotation_list
);
2361 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2362 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2365 void perf_event_task_tick(void)
2367 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2368 struct perf_cpu_context
*cpuctx
, *tmp
;
2370 WARN_ON(!irqs_disabled());
2372 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2373 if (cpuctx
->jiffies_interval
== 1 ||
2374 !(jiffies
% cpuctx
->jiffies_interval
))
2375 perf_rotate_context(cpuctx
);
2379 static int event_enable_on_exec(struct perf_event
*event
,
2380 struct perf_event_context
*ctx
)
2382 if (!event
->attr
.enable_on_exec
)
2385 event
->attr
.enable_on_exec
= 0;
2386 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2389 __perf_event_mark_enabled(event
, ctx
);
2395 * Enable all of a task's events that have been marked enable-on-exec.
2396 * This expects task == current.
2398 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2400 struct perf_event
*event
;
2401 unsigned long flags
;
2405 local_irq_save(flags
);
2406 if (!ctx
|| !ctx
->nr_events
)
2410 * We must ctxsw out cgroup events to avoid conflict
2411 * when invoking perf_task_event_sched_in() later on
2412 * in this function. Otherwise we end up trying to
2413 * ctxswin cgroup events which are already scheduled
2416 perf_cgroup_sched_out(current
);
2418 raw_spin_lock(&ctx
->lock
);
2419 task_ctx_sched_out(ctx
);
2421 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2422 ret
= event_enable_on_exec(event
, ctx
);
2427 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2428 ret
= event_enable_on_exec(event
, ctx
);
2434 * Unclone this context if we enabled any event.
2439 raw_spin_unlock(&ctx
->lock
);
2442 * Also calls ctxswin for cgroup events, if any:
2444 perf_event_context_sched_in(ctx
, ctx
->task
);
2446 local_irq_restore(flags
);
2450 * Cross CPU call to read the hardware event
2452 static void __perf_event_read(void *info
)
2454 struct perf_event
*event
= info
;
2455 struct perf_event_context
*ctx
= event
->ctx
;
2456 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2459 * If this is a task context, we need to check whether it is
2460 * the current task context of this cpu. If not it has been
2461 * scheduled out before the smp call arrived. In that case
2462 * event->count would have been updated to a recent sample
2463 * when the event was scheduled out.
2465 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2468 raw_spin_lock(&ctx
->lock
);
2469 if (ctx
->is_active
) {
2470 update_context_time(ctx
);
2471 update_cgrp_time_from_event(event
);
2473 update_event_times(event
);
2474 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2475 event
->pmu
->read(event
);
2476 raw_spin_unlock(&ctx
->lock
);
2479 static inline u64
perf_event_count(struct perf_event
*event
)
2481 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2484 static u64
perf_event_read(struct perf_event
*event
)
2487 * If event is enabled and currently active on a CPU, update the
2488 * value in the event structure:
2490 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2491 smp_call_function_single(event
->oncpu
,
2492 __perf_event_read
, event
, 1);
2493 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2494 struct perf_event_context
*ctx
= event
->ctx
;
2495 unsigned long flags
;
2497 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2499 * may read while context is not active
2500 * (e.g., thread is blocked), in that case
2501 * we cannot update context time
2503 if (ctx
->is_active
) {
2504 update_context_time(ctx
);
2505 update_cgrp_time_from_event(event
);
2507 update_event_times(event
);
2508 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2511 return perf_event_count(event
);
2518 struct callchain_cpus_entries
{
2519 struct rcu_head rcu_head
;
2520 struct perf_callchain_entry
*cpu_entries
[0];
2523 static DEFINE_PER_CPU(int, callchain_recursion
[PERF_NR_CONTEXTS
]);
2524 static atomic_t nr_callchain_events
;
2525 static DEFINE_MUTEX(callchain_mutex
);
2526 struct callchain_cpus_entries
*callchain_cpus_entries
;
2529 __weak
void perf_callchain_kernel(struct perf_callchain_entry
*entry
,
2530 struct pt_regs
*regs
)
2534 __weak
void perf_callchain_user(struct perf_callchain_entry
*entry
,
2535 struct pt_regs
*regs
)
2539 static void release_callchain_buffers_rcu(struct rcu_head
*head
)
2541 struct callchain_cpus_entries
*entries
;
2544 entries
= container_of(head
, struct callchain_cpus_entries
, rcu_head
);
2546 for_each_possible_cpu(cpu
)
2547 kfree(entries
->cpu_entries
[cpu
]);
2552 static void release_callchain_buffers(void)
2554 struct callchain_cpus_entries
*entries
;
2556 entries
= callchain_cpus_entries
;
2557 rcu_assign_pointer(callchain_cpus_entries
, NULL
);
2558 call_rcu(&entries
->rcu_head
, release_callchain_buffers_rcu
);
2561 static int alloc_callchain_buffers(void)
2565 struct callchain_cpus_entries
*entries
;
2568 * We can't use the percpu allocation API for data that can be
2569 * accessed from NMI. Use a temporary manual per cpu allocation
2570 * until that gets sorted out.
2572 size
= offsetof(struct callchain_cpus_entries
, cpu_entries
[nr_cpu_ids
]);
2574 entries
= kzalloc(size
, GFP_KERNEL
);
2578 size
= sizeof(struct perf_callchain_entry
) * PERF_NR_CONTEXTS
;
2580 for_each_possible_cpu(cpu
) {
2581 entries
->cpu_entries
[cpu
] = kmalloc_node(size
, GFP_KERNEL
,
2583 if (!entries
->cpu_entries
[cpu
])
2587 rcu_assign_pointer(callchain_cpus_entries
, entries
);
2592 for_each_possible_cpu(cpu
)
2593 kfree(entries
->cpu_entries
[cpu
]);
2599 static int get_callchain_buffers(void)
2604 mutex_lock(&callchain_mutex
);
2606 count
= atomic_inc_return(&nr_callchain_events
);
2607 if (WARN_ON_ONCE(count
< 1)) {
2613 /* If the allocation failed, give up */
2614 if (!callchain_cpus_entries
)
2619 err
= alloc_callchain_buffers();
2621 release_callchain_buffers();
2623 mutex_unlock(&callchain_mutex
);
2628 static void put_callchain_buffers(void)
2630 if (atomic_dec_and_mutex_lock(&nr_callchain_events
, &callchain_mutex
)) {
2631 release_callchain_buffers();
2632 mutex_unlock(&callchain_mutex
);
2636 static int get_recursion_context(int *recursion
)
2644 else if (in_softirq())
2649 if (recursion
[rctx
])
2658 static inline void put_recursion_context(int *recursion
, int rctx
)
2664 static struct perf_callchain_entry
*get_callchain_entry(int *rctx
)
2667 struct callchain_cpus_entries
*entries
;
2669 *rctx
= get_recursion_context(__get_cpu_var(callchain_recursion
));
2673 entries
= rcu_dereference(callchain_cpus_entries
);
2677 cpu
= smp_processor_id();
2679 return &entries
->cpu_entries
[cpu
][*rctx
];
2683 put_callchain_entry(int rctx
)
2685 put_recursion_context(__get_cpu_var(callchain_recursion
), rctx
);
2688 static struct perf_callchain_entry
*perf_callchain(struct pt_regs
*regs
)
2691 struct perf_callchain_entry
*entry
;
2694 entry
= get_callchain_entry(&rctx
);
2703 if (!user_mode(regs
)) {
2704 perf_callchain_store(entry
, PERF_CONTEXT_KERNEL
);
2705 perf_callchain_kernel(entry
, regs
);
2707 regs
= task_pt_regs(current
);
2713 perf_callchain_store(entry
, PERF_CONTEXT_USER
);
2714 perf_callchain_user(entry
, regs
);
2718 put_callchain_entry(rctx
);
2724 * Initialize the perf_event context in a task_struct:
2726 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2728 raw_spin_lock_init(&ctx
->lock
);
2729 mutex_init(&ctx
->mutex
);
2730 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2731 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2732 INIT_LIST_HEAD(&ctx
->event_list
);
2733 atomic_set(&ctx
->refcount
, 1);
2736 static struct perf_event_context
*
2737 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2739 struct perf_event_context
*ctx
;
2741 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2745 __perf_event_init_context(ctx
);
2748 get_task_struct(task
);
2755 static struct task_struct
*
2756 find_lively_task_by_vpid(pid_t vpid
)
2758 struct task_struct
*task
;
2765 task
= find_task_by_vpid(vpid
);
2767 get_task_struct(task
);
2771 return ERR_PTR(-ESRCH
);
2773 /* Reuse ptrace permission checks for now. */
2775 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2780 put_task_struct(task
);
2781 return ERR_PTR(err
);
2786 * Returns a matching context with refcount and pincount.
2788 static struct perf_event_context
*
2789 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2791 struct perf_event_context
*ctx
;
2792 struct perf_cpu_context
*cpuctx
;
2793 unsigned long flags
;
2797 /* Must be root to operate on a CPU event: */
2798 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2799 return ERR_PTR(-EACCES
);
2802 * We could be clever and allow to attach a event to an
2803 * offline CPU and activate it when the CPU comes up, but
2806 if (!cpu_online(cpu
))
2807 return ERR_PTR(-ENODEV
);
2809 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2818 ctxn
= pmu
->task_ctx_nr
;
2823 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2827 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2829 ctx
= alloc_perf_context(pmu
, task
);
2835 mutex_lock(&task
->perf_event_mutex
);
2837 * If it has already passed perf_event_exit_task().
2838 * we must see PF_EXITING, it takes this mutex too.
2840 if (task
->flags
& PF_EXITING
)
2842 else if (task
->perf_event_ctxp
[ctxn
])
2847 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2849 mutex_unlock(&task
->perf_event_mutex
);
2851 if (unlikely(err
)) {
2863 return ERR_PTR(err
);
2866 static void perf_event_free_filter(struct perf_event
*event
);
2868 static void free_event_rcu(struct rcu_head
*head
)
2870 struct perf_event
*event
;
2872 event
= container_of(head
, struct perf_event
, rcu_head
);
2874 put_pid_ns(event
->ns
);
2875 perf_event_free_filter(event
);
2879 static void perf_buffer_put(struct perf_buffer
*buffer
);
2881 static void free_event(struct perf_event
*event
)
2883 irq_work_sync(&event
->pending
);
2885 if (!event
->parent
) {
2886 if (event
->attach_state
& PERF_ATTACH_TASK
)
2887 jump_label_dec(&perf_sched_events
);
2888 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2889 atomic_dec(&nr_mmap_events
);
2890 if (event
->attr
.comm
)
2891 atomic_dec(&nr_comm_events
);
2892 if (event
->attr
.task
)
2893 atomic_dec(&nr_task_events
);
2894 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2895 put_callchain_buffers();
2896 if (is_cgroup_event(event
)) {
2897 atomic_dec(&per_cpu(perf_cgroup_events
, event
->cpu
));
2898 jump_label_dec(&perf_sched_events
);
2902 if (event
->buffer
) {
2903 perf_buffer_put(event
->buffer
);
2904 event
->buffer
= NULL
;
2907 if (is_cgroup_event(event
))
2908 perf_detach_cgroup(event
);
2911 event
->destroy(event
);
2914 put_ctx(event
->ctx
);
2916 call_rcu(&event
->rcu_head
, free_event_rcu
);
2919 int perf_event_release_kernel(struct perf_event
*event
)
2921 struct perf_event_context
*ctx
= event
->ctx
;
2924 * Remove from the PMU, can't get re-enabled since we got
2925 * here because the last ref went.
2927 perf_event_disable(event
);
2929 WARN_ON_ONCE(ctx
->parent_ctx
);
2931 * There are two ways this annotation is useful:
2933 * 1) there is a lock recursion from perf_event_exit_task
2934 * see the comment there.
2936 * 2) there is a lock-inversion with mmap_sem through
2937 * perf_event_read_group(), which takes faults while
2938 * holding ctx->mutex, however this is called after
2939 * the last filedesc died, so there is no possibility
2940 * to trigger the AB-BA case.
2942 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2943 raw_spin_lock_irq(&ctx
->lock
);
2944 perf_group_detach(event
);
2945 list_del_event(event
, ctx
);
2946 raw_spin_unlock_irq(&ctx
->lock
);
2947 mutex_unlock(&ctx
->mutex
);
2953 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2956 * Called when the last reference to the file is gone.
2958 static int perf_release(struct inode
*inode
, struct file
*file
)
2960 struct perf_event
*event
= file
->private_data
;
2961 struct task_struct
*owner
;
2963 file
->private_data
= NULL
;
2966 owner
= ACCESS_ONCE(event
->owner
);
2968 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2969 * !owner it means the list deletion is complete and we can indeed
2970 * free this event, otherwise we need to serialize on
2971 * owner->perf_event_mutex.
2973 smp_read_barrier_depends();
2976 * Since delayed_put_task_struct() also drops the last
2977 * task reference we can safely take a new reference
2978 * while holding the rcu_read_lock().
2980 get_task_struct(owner
);
2985 mutex_lock(&owner
->perf_event_mutex
);
2987 * We have to re-check the event->owner field, if it is cleared
2988 * we raced with perf_event_exit_task(), acquiring the mutex
2989 * ensured they're done, and we can proceed with freeing the
2993 list_del_init(&event
->owner_entry
);
2994 mutex_unlock(&owner
->perf_event_mutex
);
2995 put_task_struct(owner
);
2998 return perf_event_release_kernel(event
);
3001 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3003 struct perf_event
*child
;
3009 mutex_lock(&event
->child_mutex
);
3010 total
+= perf_event_read(event
);
3011 *enabled
+= event
->total_time_enabled
+
3012 atomic64_read(&event
->child_total_time_enabled
);
3013 *running
+= event
->total_time_running
+
3014 atomic64_read(&event
->child_total_time_running
);
3016 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3017 total
+= perf_event_read(child
);
3018 *enabled
+= child
->total_time_enabled
;
3019 *running
+= child
->total_time_running
;
3021 mutex_unlock(&event
->child_mutex
);
3025 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3027 static int perf_event_read_group(struct perf_event
*event
,
3028 u64 read_format
, char __user
*buf
)
3030 struct perf_event
*leader
= event
->group_leader
, *sub
;
3031 int n
= 0, size
= 0, ret
= -EFAULT
;
3032 struct perf_event_context
*ctx
= leader
->ctx
;
3034 u64 count
, enabled
, running
;
3036 mutex_lock(&ctx
->mutex
);
3037 count
= perf_event_read_value(leader
, &enabled
, &running
);
3039 values
[n
++] = 1 + leader
->nr_siblings
;
3040 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3041 values
[n
++] = enabled
;
3042 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3043 values
[n
++] = running
;
3044 values
[n
++] = count
;
3045 if (read_format
& PERF_FORMAT_ID
)
3046 values
[n
++] = primary_event_id(leader
);
3048 size
= n
* sizeof(u64
);
3050 if (copy_to_user(buf
, values
, size
))
3055 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3058 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3059 if (read_format
& PERF_FORMAT_ID
)
3060 values
[n
++] = primary_event_id(sub
);
3062 size
= n
* sizeof(u64
);
3064 if (copy_to_user(buf
+ ret
, values
, size
)) {
3072 mutex_unlock(&ctx
->mutex
);
3077 static int perf_event_read_one(struct perf_event
*event
,
3078 u64 read_format
, char __user
*buf
)
3080 u64 enabled
, running
;
3084 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3085 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3086 values
[n
++] = enabled
;
3087 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3088 values
[n
++] = running
;
3089 if (read_format
& PERF_FORMAT_ID
)
3090 values
[n
++] = primary_event_id(event
);
3092 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3095 return n
* sizeof(u64
);
3099 * Read the performance event - simple non blocking version for now
3102 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3104 u64 read_format
= event
->attr
.read_format
;
3108 * Return end-of-file for a read on a event that is in
3109 * error state (i.e. because it was pinned but it couldn't be
3110 * scheduled on to the CPU at some point).
3112 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3115 if (count
< event
->read_size
)
3118 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3119 if (read_format
& PERF_FORMAT_GROUP
)
3120 ret
= perf_event_read_group(event
, read_format
, buf
);
3122 ret
= perf_event_read_one(event
, read_format
, buf
);
3128 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3130 struct perf_event
*event
= file
->private_data
;
3132 return perf_read_hw(event
, buf
, count
);
3135 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3137 struct perf_event
*event
= file
->private_data
;
3138 struct perf_buffer
*buffer
;
3139 unsigned int events
= POLL_HUP
;
3142 buffer
= rcu_dereference(event
->buffer
);
3144 events
= atomic_xchg(&buffer
->poll
, 0);
3147 poll_wait(file
, &event
->waitq
, wait
);
3152 static void perf_event_reset(struct perf_event
*event
)
3154 (void)perf_event_read(event
);
3155 local64_set(&event
->count
, 0);
3156 perf_event_update_userpage(event
);
3160 * Holding the top-level event's child_mutex means that any
3161 * descendant process that has inherited this event will block
3162 * in sync_child_event if it goes to exit, thus satisfying the
3163 * task existence requirements of perf_event_enable/disable.
3165 static void perf_event_for_each_child(struct perf_event
*event
,
3166 void (*func
)(struct perf_event
*))
3168 struct perf_event
*child
;
3170 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3171 mutex_lock(&event
->child_mutex
);
3173 list_for_each_entry(child
, &event
->child_list
, child_list
)
3175 mutex_unlock(&event
->child_mutex
);
3178 static void perf_event_for_each(struct perf_event
*event
,
3179 void (*func
)(struct perf_event
*))
3181 struct perf_event_context
*ctx
= event
->ctx
;
3182 struct perf_event
*sibling
;
3184 WARN_ON_ONCE(ctx
->parent_ctx
);
3185 mutex_lock(&ctx
->mutex
);
3186 event
= event
->group_leader
;
3188 perf_event_for_each_child(event
, func
);
3190 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3191 perf_event_for_each_child(event
, func
);
3192 mutex_unlock(&ctx
->mutex
);
3195 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3197 struct perf_event_context
*ctx
= event
->ctx
;
3201 if (!is_sampling_event(event
))
3204 if (copy_from_user(&value
, arg
, sizeof(value
)))
3210 raw_spin_lock_irq(&ctx
->lock
);
3211 if (event
->attr
.freq
) {
3212 if (value
> sysctl_perf_event_sample_rate
) {
3217 event
->attr
.sample_freq
= value
;
3219 event
->attr
.sample_period
= value
;
3220 event
->hw
.sample_period
= value
;
3223 raw_spin_unlock_irq(&ctx
->lock
);
3228 static const struct file_operations perf_fops
;
3230 static struct perf_event
*perf_fget_light(int fd
, int *fput_needed
)
3234 file
= fget_light(fd
, fput_needed
);
3236 return ERR_PTR(-EBADF
);
3238 if (file
->f_op
!= &perf_fops
) {
3239 fput_light(file
, *fput_needed
);
3241 return ERR_PTR(-EBADF
);
3244 return file
->private_data
;
3247 static int perf_event_set_output(struct perf_event
*event
,
3248 struct perf_event
*output_event
);
3249 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3251 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3253 struct perf_event
*event
= file
->private_data
;
3254 void (*func
)(struct perf_event
*);
3258 case PERF_EVENT_IOC_ENABLE
:
3259 func
= perf_event_enable
;
3261 case PERF_EVENT_IOC_DISABLE
:
3262 func
= perf_event_disable
;
3264 case PERF_EVENT_IOC_RESET
:
3265 func
= perf_event_reset
;
3268 case PERF_EVENT_IOC_REFRESH
:
3269 return perf_event_refresh(event
, arg
);
3271 case PERF_EVENT_IOC_PERIOD
:
3272 return perf_event_period(event
, (u64 __user
*)arg
);
3274 case PERF_EVENT_IOC_SET_OUTPUT
:
3276 struct perf_event
*output_event
= NULL
;
3277 int fput_needed
= 0;
3281 output_event
= perf_fget_light(arg
, &fput_needed
);
3282 if (IS_ERR(output_event
))
3283 return PTR_ERR(output_event
);
3286 ret
= perf_event_set_output(event
, output_event
);
3288 fput_light(output_event
->filp
, fput_needed
);
3293 case PERF_EVENT_IOC_SET_FILTER
:
3294 return perf_event_set_filter(event
, (void __user
*)arg
);
3300 if (flags
& PERF_IOC_FLAG_GROUP
)
3301 perf_event_for_each(event
, func
);
3303 perf_event_for_each_child(event
, func
);
3308 int perf_event_task_enable(void)
3310 struct perf_event
*event
;
3312 mutex_lock(¤t
->perf_event_mutex
);
3313 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3314 perf_event_for_each_child(event
, perf_event_enable
);
3315 mutex_unlock(¤t
->perf_event_mutex
);
3320 int perf_event_task_disable(void)
3322 struct perf_event
*event
;
3324 mutex_lock(¤t
->perf_event_mutex
);
3325 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3326 perf_event_for_each_child(event
, perf_event_disable
);
3327 mutex_unlock(¤t
->perf_event_mutex
);
3332 #ifndef PERF_EVENT_INDEX_OFFSET
3333 # define PERF_EVENT_INDEX_OFFSET 0
3336 static int perf_event_index(struct perf_event
*event
)
3338 if (event
->hw
.state
& PERF_HES_STOPPED
)
3341 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3344 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
3348 * Callers need to ensure there can be no nesting of this function, otherwise
3349 * the seqlock logic goes bad. We can not serialize this because the arch
3350 * code calls this from NMI context.
3352 void perf_event_update_userpage(struct perf_event
*event
)
3354 struct perf_event_mmap_page
*userpg
;
3355 struct perf_buffer
*buffer
;
3358 buffer
= rcu_dereference(event
->buffer
);
3362 userpg
= buffer
->user_page
;
3365 * Disable preemption so as to not let the corresponding user-space
3366 * spin too long if we get preempted.
3371 userpg
->index
= perf_event_index(event
);
3372 userpg
->offset
= perf_event_count(event
);
3373 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3374 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3376 userpg
->time_enabled
= event
->total_time_enabled
+
3377 atomic64_read(&event
->child_total_time_enabled
);
3379 userpg
->time_running
= event
->total_time_running
+
3380 atomic64_read(&event
->child_total_time_running
);
3389 static unsigned long perf_data_size(struct perf_buffer
*buffer
);
3392 perf_buffer_init(struct perf_buffer
*buffer
, long watermark
, int flags
)
3394 long max_size
= perf_data_size(buffer
);
3397 buffer
->watermark
= min(max_size
, watermark
);
3399 if (!buffer
->watermark
)
3400 buffer
->watermark
= max_size
/ 2;
3402 if (flags
& PERF_BUFFER_WRITABLE
)
3403 buffer
->writable
= 1;
3405 atomic_set(&buffer
->refcount
, 1);
3408 #ifndef CONFIG_PERF_USE_VMALLOC
3411 * Back perf_mmap() with regular GFP_KERNEL-0 pages.
3414 static struct page
*
3415 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
3417 if (pgoff
> buffer
->nr_pages
)
3421 return virt_to_page(buffer
->user_page
);
3423 return virt_to_page(buffer
->data_pages
[pgoff
- 1]);
3426 static void *perf_mmap_alloc_page(int cpu
)
3431 node
= (cpu
== -1) ? cpu
: cpu_to_node(cpu
);
3432 page
= alloc_pages_node(node
, GFP_KERNEL
| __GFP_ZERO
, 0);
3436 return page_address(page
);
3439 static struct perf_buffer
*
3440 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
3442 struct perf_buffer
*buffer
;
3446 size
= sizeof(struct perf_buffer
);
3447 size
+= nr_pages
* sizeof(void *);
3449 buffer
= kzalloc(size
, GFP_KERNEL
);
3453 buffer
->user_page
= perf_mmap_alloc_page(cpu
);
3454 if (!buffer
->user_page
)
3455 goto fail_user_page
;
3457 for (i
= 0; i
< nr_pages
; i
++) {
3458 buffer
->data_pages
[i
] = perf_mmap_alloc_page(cpu
);
3459 if (!buffer
->data_pages
[i
])
3460 goto fail_data_pages
;
3463 buffer
->nr_pages
= nr_pages
;
3465 perf_buffer_init(buffer
, watermark
, flags
);
3470 for (i
--; i
>= 0; i
--)
3471 free_page((unsigned long)buffer
->data_pages
[i
]);
3473 free_page((unsigned long)buffer
->user_page
);
3482 static void perf_mmap_free_page(unsigned long addr
)
3484 struct page
*page
= virt_to_page((void *)addr
);
3486 page
->mapping
= NULL
;
3490 static void perf_buffer_free(struct perf_buffer
*buffer
)
3494 perf_mmap_free_page((unsigned long)buffer
->user_page
);
3495 for (i
= 0; i
< buffer
->nr_pages
; i
++)
3496 perf_mmap_free_page((unsigned long)buffer
->data_pages
[i
]);
3500 static inline int page_order(struct perf_buffer
*buffer
)
3508 * Back perf_mmap() with vmalloc memory.
3510 * Required for architectures that have d-cache aliasing issues.
3513 static inline int page_order(struct perf_buffer
*buffer
)
3515 return buffer
->page_order
;
3518 static struct page
*
3519 perf_mmap_to_page(struct perf_buffer
*buffer
, unsigned long pgoff
)
3521 if (pgoff
> (1UL << page_order(buffer
)))
3524 return vmalloc_to_page((void *)buffer
->user_page
+ pgoff
* PAGE_SIZE
);
3527 static void perf_mmap_unmark_page(void *addr
)
3529 struct page
*page
= vmalloc_to_page(addr
);
3531 page
->mapping
= NULL
;
3534 static void perf_buffer_free_work(struct work_struct
*work
)
3536 struct perf_buffer
*buffer
;
3540 buffer
= container_of(work
, struct perf_buffer
, work
);
3541 nr
= 1 << page_order(buffer
);
3543 base
= buffer
->user_page
;
3544 for (i
= 0; i
< nr
+ 1; i
++)
3545 perf_mmap_unmark_page(base
+ (i
* PAGE_SIZE
));
3551 static void perf_buffer_free(struct perf_buffer
*buffer
)
3553 schedule_work(&buffer
->work
);
3556 static struct perf_buffer
*
3557 perf_buffer_alloc(int nr_pages
, long watermark
, int cpu
, int flags
)
3559 struct perf_buffer
*buffer
;
3563 size
= sizeof(struct perf_buffer
);
3564 size
+= sizeof(void *);
3566 buffer
= kzalloc(size
, GFP_KERNEL
);
3570 INIT_WORK(&buffer
->work
, perf_buffer_free_work
);
3572 all_buf
= vmalloc_user((nr_pages
+ 1) * PAGE_SIZE
);
3576 buffer
->user_page
= all_buf
;
3577 buffer
->data_pages
[0] = all_buf
+ PAGE_SIZE
;
3578 buffer
->page_order
= ilog2(nr_pages
);
3579 buffer
->nr_pages
= 1;
3581 perf_buffer_init(buffer
, watermark
, flags
);
3594 static unsigned long perf_data_size(struct perf_buffer
*buffer
)
3596 return buffer
->nr_pages
<< (PAGE_SHIFT
+ page_order(buffer
));
3599 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3601 struct perf_event
*event
= vma
->vm_file
->private_data
;
3602 struct perf_buffer
*buffer
;
3603 int ret
= VM_FAULT_SIGBUS
;
3605 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3606 if (vmf
->pgoff
== 0)
3612 buffer
= rcu_dereference(event
->buffer
);
3616 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3619 vmf
->page
= perf_mmap_to_page(buffer
, vmf
->pgoff
);
3623 get_page(vmf
->page
);
3624 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3625 vmf
->page
->index
= vmf
->pgoff
;
3634 static void perf_buffer_free_rcu(struct rcu_head
*rcu_head
)
3636 struct perf_buffer
*buffer
;
3638 buffer
= container_of(rcu_head
, struct perf_buffer
, rcu_head
);
3639 perf_buffer_free(buffer
);
3642 static struct perf_buffer
*perf_buffer_get(struct perf_event
*event
)
3644 struct perf_buffer
*buffer
;
3647 buffer
= rcu_dereference(event
->buffer
);
3649 if (!atomic_inc_not_zero(&buffer
->refcount
))
3657 static void perf_buffer_put(struct perf_buffer
*buffer
)
3659 if (!atomic_dec_and_test(&buffer
->refcount
))
3662 call_rcu(&buffer
->rcu_head
, perf_buffer_free_rcu
);
3665 static void perf_mmap_open(struct vm_area_struct
*vma
)
3667 struct perf_event
*event
= vma
->vm_file
->private_data
;
3669 atomic_inc(&event
->mmap_count
);
3672 static void perf_mmap_close(struct vm_area_struct
*vma
)
3674 struct perf_event
*event
= vma
->vm_file
->private_data
;
3676 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3677 unsigned long size
= perf_data_size(event
->buffer
);
3678 struct user_struct
*user
= event
->mmap_user
;
3679 struct perf_buffer
*buffer
= event
->buffer
;
3681 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3682 vma
->vm_mm
->locked_vm
-= event
->mmap_locked
;
3683 rcu_assign_pointer(event
->buffer
, NULL
);
3684 mutex_unlock(&event
->mmap_mutex
);
3686 perf_buffer_put(buffer
);
3691 static const struct vm_operations_struct perf_mmap_vmops
= {
3692 .open
= perf_mmap_open
,
3693 .close
= perf_mmap_close
,
3694 .fault
= perf_mmap_fault
,
3695 .page_mkwrite
= perf_mmap_fault
,
3698 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3700 struct perf_event
*event
= file
->private_data
;
3701 unsigned long user_locked
, user_lock_limit
;
3702 struct user_struct
*user
= current_user();
3703 unsigned long locked
, lock_limit
;
3704 struct perf_buffer
*buffer
;
3705 unsigned long vma_size
;
3706 unsigned long nr_pages
;
3707 long user_extra
, extra
;
3708 int ret
= 0, flags
= 0;
3711 * Don't allow mmap() of inherited per-task counters. This would
3712 * create a performance issue due to all children writing to the
3715 if (event
->cpu
== -1 && event
->attr
.inherit
)
3718 if (!(vma
->vm_flags
& VM_SHARED
))
3721 vma_size
= vma
->vm_end
- vma
->vm_start
;
3722 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3725 * If we have buffer pages ensure they're a power-of-two number, so we
3726 * can do bitmasks instead of modulo.
3728 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3731 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3734 if (vma
->vm_pgoff
!= 0)
3737 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3738 mutex_lock(&event
->mmap_mutex
);
3739 if (event
->buffer
) {
3740 if (event
->buffer
->nr_pages
== nr_pages
)
3741 atomic_inc(&event
->buffer
->refcount
);
3747 user_extra
= nr_pages
+ 1;
3748 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3751 * Increase the limit linearly with more CPUs:
3753 user_lock_limit
*= num_online_cpus();
3755 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3758 if (user_locked
> user_lock_limit
)
3759 extra
= user_locked
- user_lock_limit
;
3761 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3762 lock_limit
>>= PAGE_SHIFT
;
3763 locked
= vma
->vm_mm
->locked_vm
+ extra
;
3765 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3766 !capable(CAP_IPC_LOCK
)) {
3771 WARN_ON(event
->buffer
);
3773 if (vma
->vm_flags
& VM_WRITE
)
3774 flags
|= PERF_BUFFER_WRITABLE
;
3776 buffer
= perf_buffer_alloc(nr_pages
, event
->attr
.wakeup_watermark
,
3782 rcu_assign_pointer(event
->buffer
, buffer
);
3784 atomic_long_add(user_extra
, &user
->locked_vm
);
3785 event
->mmap_locked
= extra
;
3786 event
->mmap_user
= get_current_user();
3787 vma
->vm_mm
->locked_vm
+= event
->mmap_locked
;
3791 atomic_inc(&event
->mmap_count
);
3792 mutex_unlock(&event
->mmap_mutex
);
3794 vma
->vm_flags
|= VM_RESERVED
;
3795 vma
->vm_ops
= &perf_mmap_vmops
;
3800 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3802 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3803 struct perf_event
*event
= filp
->private_data
;
3806 mutex_lock(&inode
->i_mutex
);
3807 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3808 mutex_unlock(&inode
->i_mutex
);
3816 static const struct file_operations perf_fops
= {
3817 .llseek
= no_llseek
,
3818 .release
= perf_release
,
3821 .unlocked_ioctl
= perf_ioctl
,
3822 .compat_ioctl
= perf_ioctl
,
3824 .fasync
= perf_fasync
,
3830 * If there's data, ensure we set the poll() state and publish everything
3831 * to user-space before waking everybody up.
3834 void perf_event_wakeup(struct perf_event
*event
)
3836 wake_up_all(&event
->waitq
);
3838 if (event
->pending_kill
) {
3839 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3840 event
->pending_kill
= 0;
3844 static void perf_pending_event(struct irq_work
*entry
)
3846 struct perf_event
*event
= container_of(entry
,
3847 struct perf_event
, pending
);
3849 if (event
->pending_disable
) {
3850 event
->pending_disable
= 0;
3851 __perf_event_disable(event
);
3854 if (event
->pending_wakeup
) {
3855 event
->pending_wakeup
= 0;
3856 perf_event_wakeup(event
);
3861 * We assume there is only KVM supporting the callbacks.
3862 * Later on, we might change it to a list if there is
3863 * another virtualization implementation supporting the callbacks.
3865 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3867 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3869 perf_guest_cbs
= cbs
;
3872 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3874 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3876 perf_guest_cbs
= NULL
;
3879 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3884 static bool perf_output_space(struct perf_buffer
*buffer
, unsigned long tail
,
3885 unsigned long offset
, unsigned long head
)
3889 if (!buffer
->writable
)
3892 mask
= perf_data_size(buffer
) - 1;
3894 offset
= (offset
- tail
) & mask
;
3895 head
= (head
- tail
) & mask
;
3897 if ((int)(head
- offset
) < 0)
3903 static void perf_output_wakeup(struct perf_output_handle
*handle
)
3905 atomic_set(&handle
->buffer
->poll
, POLL_IN
);
3908 handle
->event
->pending_wakeup
= 1;
3909 irq_work_queue(&handle
->event
->pending
);
3911 perf_event_wakeup(handle
->event
);
3915 * We need to ensure a later event_id doesn't publish a head when a former
3916 * event isn't done writing. However since we need to deal with NMIs we
3917 * cannot fully serialize things.
3919 * We only publish the head (and generate a wakeup) when the outer-most
3922 static void perf_output_get_handle(struct perf_output_handle
*handle
)
3924 struct perf_buffer
*buffer
= handle
->buffer
;
3927 local_inc(&buffer
->nest
);
3928 handle
->wakeup
= local_read(&buffer
->wakeup
);
3931 static void perf_output_put_handle(struct perf_output_handle
*handle
)
3933 struct perf_buffer
*buffer
= handle
->buffer
;
3937 head
= local_read(&buffer
->head
);
3940 * IRQ/NMI can happen here, which means we can miss a head update.
3943 if (!local_dec_and_test(&buffer
->nest
))
3947 * Publish the known good head. Rely on the full barrier implied
3948 * by atomic_dec_and_test() order the buffer->head read and this
3951 buffer
->user_page
->data_head
= head
;
3954 * Now check if we missed an update, rely on the (compiler)
3955 * barrier in atomic_dec_and_test() to re-read buffer->head.
3957 if (unlikely(head
!= local_read(&buffer
->head
))) {
3958 local_inc(&buffer
->nest
);
3962 if (handle
->wakeup
!= local_read(&buffer
->wakeup
))
3963 perf_output_wakeup(handle
);
3969 __always_inline
void perf_output_copy(struct perf_output_handle
*handle
,
3970 const void *buf
, unsigned int len
)
3973 unsigned long size
= min_t(unsigned long, handle
->size
, len
);
3975 memcpy(handle
->addr
, buf
, size
);
3978 handle
->addr
+= size
;
3980 handle
->size
-= size
;
3981 if (!handle
->size
) {
3982 struct perf_buffer
*buffer
= handle
->buffer
;
3985 handle
->page
&= buffer
->nr_pages
- 1;
3986 handle
->addr
= buffer
->data_pages
[handle
->page
];
3987 handle
->size
= PAGE_SIZE
<< page_order(buffer
);
3992 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3993 struct perf_sample_data
*data
,
3994 struct perf_event
*event
)
3996 u64 sample_type
= event
->attr
.sample_type
;
3998 data
->type
= sample_type
;
3999 header
->size
+= event
->id_header_size
;
4001 if (sample_type
& PERF_SAMPLE_TID
) {
4002 /* namespace issues */
4003 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
4004 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
4007 if (sample_type
& PERF_SAMPLE_TIME
)
4008 data
->time
= perf_clock();
4010 if (sample_type
& PERF_SAMPLE_ID
)
4011 data
->id
= primary_event_id(event
);
4013 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4014 data
->stream_id
= event
->id
;
4016 if (sample_type
& PERF_SAMPLE_CPU
) {
4017 data
->cpu_entry
.cpu
= raw_smp_processor_id();
4018 data
->cpu_entry
.reserved
= 0;
4022 static void perf_event_header__init_id(struct perf_event_header
*header
,
4023 struct perf_sample_data
*data
,
4024 struct perf_event
*event
)
4026 if (event
->attr
.sample_id_all
)
4027 __perf_event_header__init_id(header
, data
, event
);
4030 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
4031 struct perf_sample_data
*data
)
4033 u64 sample_type
= data
->type
;
4035 if (sample_type
& PERF_SAMPLE_TID
)
4036 perf_output_put(handle
, data
->tid_entry
);
4038 if (sample_type
& PERF_SAMPLE_TIME
)
4039 perf_output_put(handle
, data
->time
);
4041 if (sample_type
& PERF_SAMPLE_ID
)
4042 perf_output_put(handle
, data
->id
);
4044 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4045 perf_output_put(handle
, data
->stream_id
);
4047 if (sample_type
& PERF_SAMPLE_CPU
)
4048 perf_output_put(handle
, data
->cpu_entry
);
4051 static void perf_event__output_id_sample(struct perf_event
*event
,
4052 struct perf_output_handle
*handle
,
4053 struct perf_sample_data
*sample
)
4055 if (event
->attr
.sample_id_all
)
4056 __perf_event__output_id_sample(handle
, sample
);
4059 int perf_output_begin(struct perf_output_handle
*handle
,
4060 struct perf_event
*event
, unsigned int size
,
4061 int nmi
, int sample
)
4063 struct perf_buffer
*buffer
;
4064 unsigned long tail
, offset
, head
;
4066 struct perf_sample_data sample_data
;
4068 struct perf_event_header header
;
4075 * For inherited events we send all the output towards the parent.
4078 event
= event
->parent
;
4080 buffer
= rcu_dereference(event
->buffer
);
4084 handle
->buffer
= buffer
;
4085 handle
->event
= event
;
4087 handle
->sample
= sample
;
4089 if (!buffer
->nr_pages
)
4092 have_lost
= local_read(&buffer
->lost
);
4094 lost_event
.header
.size
= sizeof(lost_event
);
4095 perf_event_header__init_id(&lost_event
.header
, &sample_data
,
4097 size
+= lost_event
.header
.size
;
4100 perf_output_get_handle(handle
);
4104 * Userspace could choose to issue a mb() before updating the
4105 * tail pointer. So that all reads will be completed before the
4108 tail
= ACCESS_ONCE(buffer
->user_page
->data_tail
);
4110 offset
= head
= local_read(&buffer
->head
);
4112 if (unlikely(!perf_output_space(buffer
, tail
, offset
, head
)))
4114 } while (local_cmpxchg(&buffer
->head
, offset
, head
) != offset
);
4116 if (head
- local_read(&buffer
->wakeup
) > buffer
->watermark
)
4117 local_add(buffer
->watermark
, &buffer
->wakeup
);
4119 handle
->page
= offset
>> (PAGE_SHIFT
+ page_order(buffer
));
4120 handle
->page
&= buffer
->nr_pages
- 1;
4121 handle
->size
= offset
& ((PAGE_SIZE
<< page_order(buffer
)) - 1);
4122 handle
->addr
= buffer
->data_pages
[handle
->page
];
4123 handle
->addr
+= handle
->size
;
4124 handle
->size
= (PAGE_SIZE
<< page_order(buffer
)) - handle
->size
;
4127 lost_event
.header
.type
= PERF_RECORD_LOST
;
4128 lost_event
.header
.misc
= 0;
4129 lost_event
.id
= event
->id
;
4130 lost_event
.lost
= local_xchg(&buffer
->lost
, 0);
4132 perf_output_put(handle
, lost_event
);
4133 perf_event__output_id_sample(event
, handle
, &sample_data
);
4139 local_inc(&buffer
->lost
);
4140 perf_output_put_handle(handle
);
4147 void perf_output_end(struct perf_output_handle
*handle
)
4149 struct perf_event
*event
= handle
->event
;
4150 struct perf_buffer
*buffer
= handle
->buffer
;
4152 int wakeup_events
= event
->attr
.wakeup_events
;
4154 if (handle
->sample
&& wakeup_events
) {
4155 int events
= local_inc_return(&buffer
->events
);
4156 if (events
>= wakeup_events
) {
4157 local_sub(wakeup_events
, &buffer
->events
);
4158 local_inc(&buffer
->wakeup
);
4162 perf_output_put_handle(handle
);
4166 static void perf_output_read_one(struct perf_output_handle
*handle
,
4167 struct perf_event
*event
,
4168 u64 enabled
, u64 running
)
4170 u64 read_format
= event
->attr
.read_format
;
4174 values
[n
++] = perf_event_count(event
);
4175 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4176 values
[n
++] = enabled
+
4177 atomic64_read(&event
->child_total_time_enabled
);
4179 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4180 values
[n
++] = running
+
4181 atomic64_read(&event
->child_total_time_running
);
4183 if (read_format
& PERF_FORMAT_ID
)
4184 values
[n
++] = primary_event_id(event
);
4186 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4190 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
4192 static void perf_output_read_group(struct perf_output_handle
*handle
,
4193 struct perf_event
*event
,
4194 u64 enabled
, u64 running
)
4196 struct perf_event
*leader
= event
->group_leader
, *sub
;
4197 u64 read_format
= event
->attr
.read_format
;
4201 values
[n
++] = 1 + leader
->nr_siblings
;
4203 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4204 values
[n
++] = enabled
;
4206 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4207 values
[n
++] = running
;
4209 if (leader
!= event
)
4210 leader
->pmu
->read(leader
);
4212 values
[n
++] = perf_event_count(leader
);
4213 if (read_format
& PERF_FORMAT_ID
)
4214 values
[n
++] = primary_event_id(leader
);
4216 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4218 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4222 sub
->pmu
->read(sub
);
4224 values
[n
++] = perf_event_count(sub
);
4225 if (read_format
& PERF_FORMAT_ID
)
4226 values
[n
++] = primary_event_id(sub
);
4228 perf_output_copy(handle
, values
, n
* sizeof(u64
));
4232 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
4233 PERF_FORMAT_TOTAL_TIME_RUNNING)
4235 static void perf_output_read(struct perf_output_handle
*handle
,
4236 struct perf_event
*event
)
4238 u64 enabled
= 0, running
= 0, now
, ctx_time
;
4239 u64 read_format
= event
->attr
.read_format
;
4242 * compute total_time_enabled, total_time_running
4243 * based on snapshot values taken when the event
4244 * was last scheduled in.
4246 * we cannot simply called update_context_time()
4247 * because of locking issue as we are called in
4250 if (read_format
& PERF_FORMAT_TOTAL_TIMES
) {
4252 ctx_time
= event
->shadow_ctx_time
+ now
;
4253 enabled
= ctx_time
- event
->tstamp_enabled
;
4254 running
= ctx_time
- event
->tstamp_running
;
4257 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
4258 perf_output_read_group(handle
, event
, enabled
, running
);
4260 perf_output_read_one(handle
, event
, enabled
, running
);
4263 void perf_output_sample(struct perf_output_handle
*handle
,
4264 struct perf_event_header
*header
,
4265 struct perf_sample_data
*data
,
4266 struct perf_event
*event
)
4268 u64 sample_type
= data
->type
;
4270 perf_output_put(handle
, *header
);
4272 if (sample_type
& PERF_SAMPLE_IP
)
4273 perf_output_put(handle
, data
->ip
);
4275 if (sample_type
& PERF_SAMPLE_TID
)
4276 perf_output_put(handle
, data
->tid_entry
);
4278 if (sample_type
& PERF_SAMPLE_TIME
)
4279 perf_output_put(handle
, data
->time
);
4281 if (sample_type
& PERF_SAMPLE_ADDR
)
4282 perf_output_put(handle
, data
->addr
);
4284 if (sample_type
& PERF_SAMPLE_ID
)
4285 perf_output_put(handle
, data
->id
);
4287 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4288 perf_output_put(handle
, data
->stream_id
);
4290 if (sample_type
& PERF_SAMPLE_CPU
)
4291 perf_output_put(handle
, data
->cpu_entry
);
4293 if (sample_type
& PERF_SAMPLE_PERIOD
)
4294 perf_output_put(handle
, data
->period
);
4296 if (sample_type
& PERF_SAMPLE_READ
)
4297 perf_output_read(handle
, event
);
4299 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4300 if (data
->callchain
) {
4303 if (data
->callchain
)
4304 size
+= data
->callchain
->nr
;
4306 size
*= sizeof(u64
);
4308 perf_output_copy(handle
, data
->callchain
, size
);
4311 perf_output_put(handle
, nr
);
4315 if (sample_type
& PERF_SAMPLE_RAW
) {
4317 perf_output_put(handle
, data
->raw
->size
);
4318 perf_output_copy(handle
, data
->raw
->data
,
4325 .size
= sizeof(u32
),
4328 perf_output_put(handle
, raw
);
4333 void perf_prepare_sample(struct perf_event_header
*header
,
4334 struct perf_sample_data
*data
,
4335 struct perf_event
*event
,
4336 struct pt_regs
*regs
)
4338 u64 sample_type
= event
->attr
.sample_type
;
4340 header
->type
= PERF_RECORD_SAMPLE
;
4341 header
->size
= sizeof(*header
) + event
->header_size
;
4344 header
->misc
|= perf_misc_flags(regs
);
4346 __perf_event_header__init_id(header
, data
, event
);
4348 if (sample_type
& PERF_SAMPLE_IP
)
4349 data
->ip
= perf_instruction_pointer(regs
);
4351 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4354 data
->callchain
= perf_callchain(regs
);
4356 if (data
->callchain
)
4357 size
+= data
->callchain
->nr
;
4359 header
->size
+= size
* sizeof(u64
);
4362 if (sample_type
& PERF_SAMPLE_RAW
) {
4363 int size
= sizeof(u32
);
4366 size
+= data
->raw
->size
;
4368 size
+= sizeof(u32
);
4370 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4371 header
->size
+= size
;
4375 static void perf_event_output(struct perf_event
*event
, int nmi
,
4376 struct perf_sample_data
*data
,
4377 struct pt_regs
*regs
)
4379 struct perf_output_handle handle
;
4380 struct perf_event_header header
;
4382 /* protect the callchain buffers */
4385 perf_prepare_sample(&header
, data
, event
, regs
);
4387 if (perf_output_begin(&handle
, event
, header
.size
, nmi
, 1))
4390 perf_output_sample(&handle
, &header
, data
, event
);
4392 perf_output_end(&handle
);
4402 struct perf_read_event
{
4403 struct perf_event_header header
;
4410 perf_event_read_event(struct perf_event
*event
,
4411 struct task_struct
*task
)
4413 struct perf_output_handle handle
;
4414 struct perf_sample_data sample
;
4415 struct perf_read_event read_event
= {
4417 .type
= PERF_RECORD_READ
,
4419 .size
= sizeof(read_event
) + event
->read_size
,
4421 .pid
= perf_event_pid(event
, task
),
4422 .tid
= perf_event_tid(event
, task
),
4426 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4427 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
, 0, 0);
4431 perf_output_put(&handle
, read_event
);
4432 perf_output_read(&handle
, event
);
4433 perf_event__output_id_sample(event
, &handle
, &sample
);
4435 perf_output_end(&handle
);
4439 * task tracking -- fork/exit
4441 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
4444 struct perf_task_event
{
4445 struct task_struct
*task
;
4446 struct perf_event_context
*task_ctx
;
4449 struct perf_event_header header
;
4459 static void perf_event_task_output(struct perf_event
*event
,
4460 struct perf_task_event
*task_event
)
4462 struct perf_output_handle handle
;
4463 struct perf_sample_data sample
;
4464 struct task_struct
*task
= task_event
->task
;
4465 int ret
, size
= task_event
->event_id
.header
.size
;
4467 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4469 ret
= perf_output_begin(&handle
, event
,
4470 task_event
->event_id
.header
.size
, 0, 0);
4474 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4475 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4477 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4478 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4480 perf_output_put(&handle
, task_event
->event_id
);
4482 perf_event__output_id_sample(event
, &handle
, &sample
);
4484 perf_output_end(&handle
);
4486 task_event
->event_id
.header
.size
= size
;
4489 static int perf_event_task_match(struct perf_event
*event
)
4491 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4494 if (!event_filter_match(event
))
4497 if (event
->attr
.comm
|| event
->attr
.mmap
||
4498 event
->attr
.mmap_data
|| event
->attr
.task
)
4504 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
4505 struct perf_task_event
*task_event
)
4507 struct perf_event
*event
;
4509 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4510 if (perf_event_task_match(event
))
4511 perf_event_task_output(event
, task_event
);
4515 static void perf_event_task_event(struct perf_task_event
*task_event
)
4517 struct perf_cpu_context
*cpuctx
;
4518 struct perf_event_context
*ctx
;
4523 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4524 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4525 if (cpuctx
->active_pmu
!= pmu
)
4527 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
4529 ctx
= task_event
->task_ctx
;
4531 ctxn
= pmu
->task_ctx_nr
;
4534 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4537 perf_event_task_ctx(ctx
, task_event
);
4539 put_cpu_ptr(pmu
->pmu_cpu_context
);
4544 static void perf_event_task(struct task_struct
*task
,
4545 struct perf_event_context
*task_ctx
,
4548 struct perf_task_event task_event
;
4550 if (!atomic_read(&nr_comm_events
) &&
4551 !atomic_read(&nr_mmap_events
) &&
4552 !atomic_read(&nr_task_events
))
4555 task_event
= (struct perf_task_event
){
4557 .task_ctx
= task_ctx
,
4560 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4562 .size
= sizeof(task_event
.event_id
),
4568 .time
= perf_clock(),
4572 perf_event_task_event(&task_event
);
4575 void perf_event_fork(struct task_struct
*task
)
4577 perf_event_task(task
, NULL
, 1);
4584 struct perf_comm_event
{
4585 struct task_struct
*task
;
4590 struct perf_event_header header
;
4597 static void perf_event_comm_output(struct perf_event
*event
,
4598 struct perf_comm_event
*comm_event
)
4600 struct perf_output_handle handle
;
4601 struct perf_sample_data sample
;
4602 int size
= comm_event
->event_id
.header
.size
;
4605 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4606 ret
= perf_output_begin(&handle
, event
,
4607 comm_event
->event_id
.header
.size
, 0, 0);
4612 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4613 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4615 perf_output_put(&handle
, comm_event
->event_id
);
4616 perf_output_copy(&handle
, comm_event
->comm
,
4617 comm_event
->comm_size
);
4619 perf_event__output_id_sample(event
, &handle
, &sample
);
4621 perf_output_end(&handle
);
4623 comm_event
->event_id
.header
.size
= size
;
4626 static int perf_event_comm_match(struct perf_event
*event
)
4628 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4631 if (!event_filter_match(event
))
4634 if (event
->attr
.comm
)
4640 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4641 struct perf_comm_event
*comm_event
)
4643 struct perf_event
*event
;
4645 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4646 if (perf_event_comm_match(event
))
4647 perf_event_comm_output(event
, comm_event
);
4651 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4653 struct perf_cpu_context
*cpuctx
;
4654 struct perf_event_context
*ctx
;
4655 char comm
[TASK_COMM_LEN
];
4660 memset(comm
, 0, sizeof(comm
));
4661 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4662 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4664 comm_event
->comm
= comm
;
4665 comm_event
->comm_size
= size
;
4667 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4669 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4670 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4671 if (cpuctx
->active_pmu
!= pmu
)
4673 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4675 ctxn
= pmu
->task_ctx_nr
;
4679 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4681 perf_event_comm_ctx(ctx
, comm_event
);
4683 put_cpu_ptr(pmu
->pmu_cpu_context
);
4688 void perf_event_comm(struct task_struct
*task
)
4690 struct perf_comm_event comm_event
;
4691 struct perf_event_context
*ctx
;
4694 for_each_task_context_nr(ctxn
) {
4695 ctx
= task
->perf_event_ctxp
[ctxn
];
4699 perf_event_enable_on_exec(ctx
);
4702 if (!atomic_read(&nr_comm_events
))
4705 comm_event
= (struct perf_comm_event
){
4711 .type
= PERF_RECORD_COMM
,
4720 perf_event_comm_event(&comm_event
);
4727 struct perf_mmap_event
{
4728 struct vm_area_struct
*vma
;
4730 const char *file_name
;
4734 struct perf_event_header header
;
4744 static void perf_event_mmap_output(struct perf_event
*event
,
4745 struct perf_mmap_event
*mmap_event
)
4747 struct perf_output_handle handle
;
4748 struct perf_sample_data sample
;
4749 int size
= mmap_event
->event_id
.header
.size
;
4752 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4753 ret
= perf_output_begin(&handle
, event
,
4754 mmap_event
->event_id
.header
.size
, 0, 0);
4758 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4759 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4761 perf_output_put(&handle
, mmap_event
->event_id
);
4762 perf_output_copy(&handle
, mmap_event
->file_name
,
4763 mmap_event
->file_size
);
4765 perf_event__output_id_sample(event
, &handle
, &sample
);
4767 perf_output_end(&handle
);
4769 mmap_event
->event_id
.header
.size
= size
;
4772 static int perf_event_mmap_match(struct perf_event
*event
,
4773 struct perf_mmap_event
*mmap_event
,
4776 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4779 if (!event_filter_match(event
))
4782 if ((!executable
&& event
->attr
.mmap_data
) ||
4783 (executable
&& event
->attr
.mmap
))
4789 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4790 struct perf_mmap_event
*mmap_event
,
4793 struct perf_event
*event
;
4795 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4796 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4797 perf_event_mmap_output(event
, mmap_event
);
4801 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4803 struct perf_cpu_context
*cpuctx
;
4804 struct perf_event_context
*ctx
;
4805 struct vm_area_struct
*vma
= mmap_event
->vma
;
4806 struct file
*file
= vma
->vm_file
;
4814 memset(tmp
, 0, sizeof(tmp
));
4818 * d_path works from the end of the buffer backwards, so we
4819 * need to add enough zero bytes after the string to handle
4820 * the 64bit alignment we do later.
4822 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4824 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4827 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4829 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4833 if (arch_vma_name(mmap_event
->vma
)) {
4834 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4840 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4842 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4843 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4844 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4846 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4847 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4848 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4852 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4857 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4859 mmap_event
->file_name
= name
;
4860 mmap_event
->file_size
= size
;
4862 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4865 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4866 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4867 if (cpuctx
->active_pmu
!= pmu
)
4869 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4870 vma
->vm_flags
& VM_EXEC
);
4872 ctxn
= pmu
->task_ctx_nr
;
4876 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4878 perf_event_mmap_ctx(ctx
, mmap_event
,
4879 vma
->vm_flags
& VM_EXEC
);
4882 put_cpu_ptr(pmu
->pmu_cpu_context
);
4889 void perf_event_mmap(struct vm_area_struct
*vma
)
4891 struct perf_mmap_event mmap_event
;
4893 if (!atomic_read(&nr_mmap_events
))
4896 mmap_event
= (struct perf_mmap_event
){
4902 .type
= PERF_RECORD_MMAP
,
4903 .misc
= PERF_RECORD_MISC_USER
,
4908 .start
= vma
->vm_start
,
4909 .len
= vma
->vm_end
- vma
->vm_start
,
4910 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4914 perf_event_mmap_event(&mmap_event
);
4918 * IRQ throttle logging
4921 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4923 struct perf_output_handle handle
;
4924 struct perf_sample_data sample
;
4928 struct perf_event_header header
;
4932 } throttle_event
= {
4934 .type
= PERF_RECORD_THROTTLE
,
4936 .size
= sizeof(throttle_event
),
4938 .time
= perf_clock(),
4939 .id
= primary_event_id(event
),
4940 .stream_id
= event
->id
,
4944 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4946 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4948 ret
= perf_output_begin(&handle
, event
,
4949 throttle_event
.header
.size
, 1, 0);
4953 perf_output_put(&handle
, throttle_event
);
4954 perf_event__output_id_sample(event
, &handle
, &sample
);
4955 perf_output_end(&handle
);
4959 * Generic event overflow handling, sampling.
4962 static int __perf_event_overflow(struct perf_event
*event
, int nmi
,
4963 int throttle
, struct perf_sample_data
*data
,
4964 struct pt_regs
*regs
)
4966 int events
= atomic_read(&event
->event_limit
);
4967 struct hw_perf_event
*hwc
= &event
->hw
;
4971 * Non-sampling counters might still use the PMI to fold short
4972 * hardware counters, ignore those.
4974 if (unlikely(!is_sampling_event(event
)))
4977 if (unlikely(hwc
->interrupts
>= max_samples_per_tick
)) {
4979 hwc
->interrupts
= MAX_INTERRUPTS
;
4980 perf_log_throttle(event
, 0);
4986 if (event
->attr
.freq
) {
4987 u64 now
= perf_clock();
4988 s64 delta
= now
- hwc
->freq_time_stamp
;
4990 hwc
->freq_time_stamp
= now
;
4992 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4993 perf_adjust_period(event
, delta
, hwc
->last_period
);
4997 * XXX event_limit might not quite work as expected on inherited
5001 event
->pending_kill
= POLL_IN
;
5002 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
5004 event
->pending_kill
= POLL_HUP
;
5006 event
->pending_disable
= 1;
5007 irq_work_queue(&event
->pending
);
5009 perf_event_disable(event
);
5012 if (event
->overflow_handler
)
5013 event
->overflow_handler(event
, nmi
, data
, regs
);
5015 perf_event_output(event
, nmi
, data
, regs
);
5017 if (event
->fasync
&& event
->pending_kill
) {
5019 event
->pending_wakeup
= 1;
5020 irq_work_queue(&event
->pending
);
5022 perf_event_wakeup(event
);
5028 int perf_event_overflow(struct perf_event
*event
, int nmi
,
5029 struct perf_sample_data
*data
,
5030 struct pt_regs
*regs
)
5032 return __perf_event_overflow(event
, nmi
, 1, data
, regs
);
5036 * Generic software event infrastructure
5039 struct swevent_htable
{
5040 struct swevent_hlist
*swevent_hlist
;
5041 struct mutex hlist_mutex
;
5044 /* Recursion avoidance in each contexts */
5045 int recursion
[PERF_NR_CONTEXTS
];
5048 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
5051 * We directly increment event->count and keep a second value in
5052 * event->hw.period_left to count intervals. This period event
5053 * is kept in the range [-sample_period, 0] so that we can use the
5057 static u64
perf_swevent_set_period(struct perf_event
*event
)
5059 struct hw_perf_event
*hwc
= &event
->hw
;
5060 u64 period
= hwc
->last_period
;
5064 hwc
->last_period
= hwc
->sample_period
;
5067 old
= val
= local64_read(&hwc
->period_left
);
5071 nr
= div64_u64(period
+ val
, period
);
5072 offset
= nr
* period
;
5074 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
5080 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
5081 int nmi
, struct perf_sample_data
*data
,
5082 struct pt_regs
*regs
)
5084 struct hw_perf_event
*hwc
= &event
->hw
;
5087 data
->period
= event
->hw
.last_period
;
5089 overflow
= perf_swevent_set_period(event
);
5091 if (hwc
->interrupts
== MAX_INTERRUPTS
)
5094 for (; overflow
; overflow
--) {
5095 if (__perf_event_overflow(event
, nmi
, throttle
,
5098 * We inhibit the overflow from happening when
5099 * hwc->interrupts == MAX_INTERRUPTS.
5107 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
5108 int nmi
, struct perf_sample_data
*data
,
5109 struct pt_regs
*regs
)
5111 struct hw_perf_event
*hwc
= &event
->hw
;
5113 local64_add(nr
, &event
->count
);
5118 if (!is_sampling_event(event
))
5121 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
5122 return perf_swevent_overflow(event
, 1, nmi
, data
, regs
);
5124 if (local64_add_negative(nr
, &hwc
->period_left
))
5127 perf_swevent_overflow(event
, 0, nmi
, data
, regs
);
5130 static int perf_exclude_event(struct perf_event
*event
,
5131 struct pt_regs
*regs
)
5133 if (event
->hw
.state
& PERF_HES_STOPPED
)
5137 if (event
->attr
.exclude_user
&& user_mode(regs
))
5140 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
5147 static int perf_swevent_match(struct perf_event
*event
,
5148 enum perf_type_id type
,
5150 struct perf_sample_data
*data
,
5151 struct pt_regs
*regs
)
5153 if (event
->attr
.type
!= type
)
5156 if (event
->attr
.config
!= event_id
)
5159 if (perf_exclude_event(event
, regs
))
5165 static inline u64
swevent_hash(u64 type
, u32 event_id
)
5167 u64 val
= event_id
| (type
<< 32);
5169 return hash_64(val
, SWEVENT_HLIST_BITS
);
5172 static inline struct hlist_head
*
5173 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
5175 u64 hash
= swevent_hash(type
, event_id
);
5177 return &hlist
->heads
[hash
];
5180 /* For the read side: events when they trigger */
5181 static inline struct hlist_head
*
5182 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
5184 struct swevent_hlist
*hlist
;
5186 hlist
= rcu_dereference(swhash
->swevent_hlist
);
5190 return __find_swevent_head(hlist
, type
, event_id
);
5193 /* For the event head insertion and removal in the hlist */
5194 static inline struct hlist_head
*
5195 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
5197 struct swevent_hlist
*hlist
;
5198 u32 event_id
= event
->attr
.config
;
5199 u64 type
= event
->attr
.type
;
5202 * Event scheduling is always serialized against hlist allocation
5203 * and release. Which makes the protected version suitable here.
5204 * The context lock guarantees that.
5206 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
5207 lockdep_is_held(&event
->ctx
->lock
));
5211 return __find_swevent_head(hlist
, type
, event_id
);
5214 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
5216 struct perf_sample_data
*data
,
5217 struct pt_regs
*regs
)
5219 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5220 struct perf_event
*event
;
5221 struct hlist_node
*node
;
5222 struct hlist_head
*head
;
5225 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
5229 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5230 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
5231 perf_swevent_event(event
, nr
, nmi
, data
, regs
);
5237 int perf_swevent_get_recursion_context(void)
5239 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5241 return get_recursion_context(swhash
->recursion
);
5243 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
5245 inline void perf_swevent_put_recursion_context(int rctx
)
5247 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5249 put_recursion_context(swhash
->recursion
, rctx
);
5252 void __perf_sw_event(u32 event_id
, u64 nr
, int nmi
,
5253 struct pt_regs
*regs
, u64 addr
)
5255 struct perf_sample_data data
;
5258 preempt_disable_notrace();
5259 rctx
= perf_swevent_get_recursion_context();
5263 perf_sample_data_init(&data
, addr
);
5265 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, nmi
, &data
, regs
);
5267 perf_swevent_put_recursion_context(rctx
);
5268 preempt_enable_notrace();
5271 static void perf_swevent_read(struct perf_event
*event
)
5275 static int perf_swevent_add(struct perf_event
*event
, int flags
)
5277 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5278 struct hw_perf_event
*hwc
= &event
->hw
;
5279 struct hlist_head
*head
;
5281 if (is_sampling_event(event
)) {
5282 hwc
->last_period
= hwc
->sample_period
;
5283 perf_swevent_set_period(event
);
5286 hwc
->state
= !(flags
& PERF_EF_START
);
5288 head
= find_swevent_head(swhash
, event
);
5289 if (WARN_ON_ONCE(!head
))
5292 hlist_add_head_rcu(&event
->hlist_entry
, head
);
5297 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5299 hlist_del_rcu(&event
->hlist_entry
);
5302 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5304 event
->hw
.state
= 0;
5307 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5309 event
->hw
.state
= PERF_HES_STOPPED
;
5312 /* Deref the hlist from the update side */
5313 static inline struct swevent_hlist
*
5314 swevent_hlist_deref(struct swevent_htable
*swhash
)
5316 return rcu_dereference_protected(swhash
->swevent_hlist
,
5317 lockdep_is_held(&swhash
->hlist_mutex
));
5320 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5322 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5327 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5328 kfree_rcu(hlist
, rcu_head
);
5331 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5333 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5335 mutex_lock(&swhash
->hlist_mutex
);
5337 if (!--swhash
->hlist_refcount
)
5338 swevent_hlist_release(swhash
);
5340 mutex_unlock(&swhash
->hlist_mutex
);
5343 static void swevent_hlist_put(struct perf_event
*event
)
5347 if (event
->cpu
!= -1) {
5348 swevent_hlist_put_cpu(event
, event
->cpu
);
5352 for_each_possible_cpu(cpu
)
5353 swevent_hlist_put_cpu(event
, cpu
);
5356 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5358 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5361 mutex_lock(&swhash
->hlist_mutex
);
5363 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5364 struct swevent_hlist
*hlist
;
5366 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5371 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5373 swhash
->hlist_refcount
++;
5375 mutex_unlock(&swhash
->hlist_mutex
);
5380 static int swevent_hlist_get(struct perf_event
*event
)
5383 int cpu
, failed_cpu
;
5385 if (event
->cpu
!= -1)
5386 return swevent_hlist_get_cpu(event
, event
->cpu
);
5389 for_each_possible_cpu(cpu
) {
5390 err
= swevent_hlist_get_cpu(event
, cpu
);
5400 for_each_possible_cpu(cpu
) {
5401 if (cpu
== failed_cpu
)
5403 swevent_hlist_put_cpu(event
, cpu
);
5410 struct jump_label_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5412 static void sw_perf_event_destroy(struct perf_event
*event
)
5414 u64 event_id
= event
->attr
.config
;
5416 WARN_ON(event
->parent
);
5418 jump_label_dec(&perf_swevent_enabled
[event_id
]);
5419 swevent_hlist_put(event
);
5422 static int perf_swevent_init(struct perf_event
*event
)
5424 int event_id
= event
->attr
.config
;
5426 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5430 case PERF_COUNT_SW_CPU_CLOCK
:
5431 case PERF_COUNT_SW_TASK_CLOCK
:
5438 if (event_id
>= PERF_COUNT_SW_MAX
)
5441 if (!event
->parent
) {
5444 err
= swevent_hlist_get(event
);
5448 jump_label_inc(&perf_swevent_enabled
[event_id
]);
5449 event
->destroy
= sw_perf_event_destroy
;
5455 static struct pmu perf_swevent
= {
5456 .task_ctx_nr
= perf_sw_context
,
5458 .event_init
= perf_swevent_init
,
5459 .add
= perf_swevent_add
,
5460 .del
= perf_swevent_del
,
5461 .start
= perf_swevent_start
,
5462 .stop
= perf_swevent_stop
,
5463 .read
= perf_swevent_read
,
5466 #ifdef CONFIG_EVENT_TRACING
5468 static int perf_tp_filter_match(struct perf_event
*event
,
5469 struct perf_sample_data
*data
)
5471 void *record
= data
->raw
->data
;
5473 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5478 static int perf_tp_event_match(struct perf_event
*event
,
5479 struct perf_sample_data
*data
,
5480 struct pt_regs
*regs
)
5482 if (event
->hw
.state
& PERF_HES_STOPPED
)
5485 * All tracepoints are from kernel-space.
5487 if (event
->attr
.exclude_kernel
)
5490 if (!perf_tp_filter_match(event
, data
))
5496 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5497 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
5499 struct perf_sample_data data
;
5500 struct perf_event
*event
;
5501 struct hlist_node
*node
;
5503 struct perf_raw_record raw
= {
5508 perf_sample_data_init(&data
, addr
);
5511 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5512 if (perf_tp_event_match(event
, &data
, regs
))
5513 perf_swevent_event(event
, count
, 1, &data
, regs
);
5516 perf_swevent_put_recursion_context(rctx
);
5518 EXPORT_SYMBOL_GPL(perf_tp_event
);
5520 static void tp_perf_event_destroy(struct perf_event
*event
)
5522 perf_trace_destroy(event
);
5525 static int perf_tp_event_init(struct perf_event
*event
)
5529 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5532 err
= perf_trace_init(event
);
5536 event
->destroy
= tp_perf_event_destroy
;
5541 static struct pmu perf_tracepoint
= {
5542 .task_ctx_nr
= perf_sw_context
,
5544 .event_init
= perf_tp_event_init
,
5545 .add
= perf_trace_add
,
5546 .del
= perf_trace_del
,
5547 .start
= perf_swevent_start
,
5548 .stop
= perf_swevent_stop
,
5549 .read
= perf_swevent_read
,
5552 static inline void perf_tp_register(void)
5554 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5557 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5562 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5565 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5566 if (IS_ERR(filter_str
))
5567 return PTR_ERR(filter_str
);
5569 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5575 static void perf_event_free_filter(struct perf_event
*event
)
5577 ftrace_profile_free_filter(event
);
5582 static inline void perf_tp_register(void)
5586 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5591 static void perf_event_free_filter(struct perf_event
*event
)
5595 #endif /* CONFIG_EVENT_TRACING */
5597 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5598 void perf_bp_event(struct perf_event
*bp
, void *data
)
5600 struct perf_sample_data sample
;
5601 struct pt_regs
*regs
= data
;
5603 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
5605 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5606 perf_swevent_event(bp
, 1, 1, &sample
, regs
);
5611 * hrtimer based swevent callback
5614 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5616 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5617 struct perf_sample_data data
;
5618 struct pt_regs
*regs
;
5619 struct perf_event
*event
;
5622 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5624 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5625 return HRTIMER_NORESTART
;
5627 event
->pmu
->read(event
);
5629 perf_sample_data_init(&data
, 0);
5630 data
.period
= event
->hw
.last_period
;
5631 regs
= get_irq_regs();
5633 if (regs
&& !perf_exclude_event(event
, regs
)) {
5634 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
5635 if (perf_event_overflow(event
, 0, &data
, regs
))
5636 ret
= HRTIMER_NORESTART
;
5639 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5640 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5645 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5647 struct hw_perf_event
*hwc
= &event
->hw
;
5650 if (!is_sampling_event(event
))
5653 period
= local64_read(&hwc
->period_left
);
5658 local64_set(&hwc
->period_left
, 0);
5660 period
= max_t(u64
, 10000, hwc
->sample_period
);
5662 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5663 ns_to_ktime(period
), 0,
5664 HRTIMER_MODE_REL_PINNED
, 0);
5667 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5669 struct hw_perf_event
*hwc
= &event
->hw
;
5671 if (is_sampling_event(event
)) {
5672 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5673 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5675 hrtimer_cancel(&hwc
->hrtimer
);
5679 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
5681 struct hw_perf_event
*hwc
= &event
->hw
;
5683 if (!is_sampling_event(event
))
5686 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5687 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5690 * Since hrtimers have a fixed rate, we can do a static freq->period
5691 * mapping and avoid the whole period adjust feedback stuff.
5693 if (event
->attr
.freq
) {
5694 long freq
= event
->attr
.sample_freq
;
5696 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
5697 hwc
->sample_period
= event
->attr
.sample_period
;
5698 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5699 event
->attr
.freq
= 0;
5704 * Software event: cpu wall time clock
5707 static void cpu_clock_event_update(struct perf_event
*event
)
5712 now
= local_clock();
5713 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5714 local64_add(now
- prev
, &event
->count
);
5717 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5719 local64_set(&event
->hw
.prev_count
, local_clock());
5720 perf_swevent_start_hrtimer(event
);
5723 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5725 perf_swevent_cancel_hrtimer(event
);
5726 cpu_clock_event_update(event
);
5729 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5731 if (flags
& PERF_EF_START
)
5732 cpu_clock_event_start(event
, flags
);
5737 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5739 cpu_clock_event_stop(event
, flags
);
5742 static void cpu_clock_event_read(struct perf_event
*event
)
5744 cpu_clock_event_update(event
);
5747 static int cpu_clock_event_init(struct perf_event
*event
)
5749 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5752 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5755 perf_swevent_init_hrtimer(event
);
5760 static struct pmu perf_cpu_clock
= {
5761 .task_ctx_nr
= perf_sw_context
,
5763 .event_init
= cpu_clock_event_init
,
5764 .add
= cpu_clock_event_add
,
5765 .del
= cpu_clock_event_del
,
5766 .start
= cpu_clock_event_start
,
5767 .stop
= cpu_clock_event_stop
,
5768 .read
= cpu_clock_event_read
,
5772 * Software event: task time clock
5775 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5780 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5782 local64_add(delta
, &event
->count
);
5785 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5787 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5788 perf_swevent_start_hrtimer(event
);
5791 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5793 perf_swevent_cancel_hrtimer(event
);
5794 task_clock_event_update(event
, event
->ctx
->time
);
5797 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5799 if (flags
& PERF_EF_START
)
5800 task_clock_event_start(event
, flags
);
5805 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5807 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5810 static void task_clock_event_read(struct perf_event
*event
)
5812 u64 now
= perf_clock();
5813 u64 delta
= now
- event
->ctx
->timestamp
;
5814 u64 time
= event
->ctx
->time
+ delta
;
5816 task_clock_event_update(event
, time
);
5819 static int task_clock_event_init(struct perf_event
*event
)
5821 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5824 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5827 perf_swevent_init_hrtimer(event
);
5832 static struct pmu perf_task_clock
= {
5833 .task_ctx_nr
= perf_sw_context
,
5835 .event_init
= task_clock_event_init
,
5836 .add
= task_clock_event_add
,
5837 .del
= task_clock_event_del
,
5838 .start
= task_clock_event_start
,
5839 .stop
= task_clock_event_stop
,
5840 .read
= task_clock_event_read
,
5843 static void perf_pmu_nop_void(struct pmu
*pmu
)
5847 static int perf_pmu_nop_int(struct pmu
*pmu
)
5852 static void perf_pmu_start_txn(struct pmu
*pmu
)
5854 perf_pmu_disable(pmu
);
5857 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5859 perf_pmu_enable(pmu
);
5863 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5865 perf_pmu_enable(pmu
);
5869 * Ensures all contexts with the same task_ctx_nr have the same
5870 * pmu_cpu_context too.
5872 static void *find_pmu_context(int ctxn
)
5879 list_for_each_entry(pmu
, &pmus
, entry
) {
5880 if (pmu
->task_ctx_nr
== ctxn
)
5881 return pmu
->pmu_cpu_context
;
5887 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5891 for_each_possible_cpu(cpu
) {
5892 struct perf_cpu_context
*cpuctx
;
5894 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5896 if (cpuctx
->active_pmu
== old_pmu
)
5897 cpuctx
->active_pmu
= pmu
;
5901 static void free_pmu_context(struct pmu
*pmu
)
5905 mutex_lock(&pmus_lock
);
5907 * Like a real lame refcount.
5909 list_for_each_entry(i
, &pmus
, entry
) {
5910 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5911 update_pmu_context(i
, pmu
);
5916 free_percpu(pmu
->pmu_cpu_context
);
5918 mutex_unlock(&pmus_lock
);
5920 static struct idr pmu_idr
;
5923 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5925 struct pmu
*pmu
= dev_get_drvdata(dev
);
5927 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5930 static struct device_attribute pmu_dev_attrs
[] = {
5935 static int pmu_bus_running
;
5936 static struct bus_type pmu_bus
= {
5937 .name
= "event_source",
5938 .dev_attrs
= pmu_dev_attrs
,
5941 static void pmu_dev_release(struct device
*dev
)
5946 static int pmu_dev_alloc(struct pmu
*pmu
)
5950 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5954 device_initialize(pmu
->dev
);
5955 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5959 dev_set_drvdata(pmu
->dev
, pmu
);
5960 pmu
->dev
->bus
= &pmu_bus
;
5961 pmu
->dev
->release
= pmu_dev_release
;
5962 ret
= device_add(pmu
->dev
);
5970 put_device(pmu
->dev
);
5974 static struct lock_class_key cpuctx_mutex
;
5975 static struct lock_class_key cpuctx_lock
;
5977 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5981 mutex_lock(&pmus_lock
);
5983 pmu
->pmu_disable_count
= alloc_percpu(int);
5984 if (!pmu
->pmu_disable_count
)
5993 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
5997 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
6005 if (pmu_bus_running
) {
6006 ret
= pmu_dev_alloc(pmu
);
6012 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
6013 if (pmu
->pmu_cpu_context
)
6014 goto got_cpu_context
;
6016 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
6017 if (!pmu
->pmu_cpu_context
)
6020 for_each_possible_cpu(cpu
) {
6021 struct perf_cpu_context
*cpuctx
;
6023 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6024 __perf_event_init_context(&cpuctx
->ctx
);
6025 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
6026 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
6027 cpuctx
->ctx
.type
= cpu_context
;
6028 cpuctx
->ctx
.pmu
= pmu
;
6029 cpuctx
->jiffies_interval
= 1;
6030 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
6031 cpuctx
->active_pmu
= pmu
;
6035 if (!pmu
->start_txn
) {
6036 if (pmu
->pmu_enable
) {
6038 * If we have pmu_enable/pmu_disable calls, install
6039 * transaction stubs that use that to try and batch
6040 * hardware accesses.
6042 pmu
->start_txn
= perf_pmu_start_txn
;
6043 pmu
->commit_txn
= perf_pmu_commit_txn
;
6044 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
6046 pmu
->start_txn
= perf_pmu_nop_void
;
6047 pmu
->commit_txn
= perf_pmu_nop_int
;
6048 pmu
->cancel_txn
= perf_pmu_nop_void
;
6052 if (!pmu
->pmu_enable
) {
6053 pmu
->pmu_enable
= perf_pmu_nop_void
;
6054 pmu
->pmu_disable
= perf_pmu_nop_void
;
6057 list_add_rcu(&pmu
->entry
, &pmus
);
6060 mutex_unlock(&pmus_lock
);
6065 device_del(pmu
->dev
);
6066 put_device(pmu
->dev
);
6069 if (pmu
->type
>= PERF_TYPE_MAX
)
6070 idr_remove(&pmu_idr
, pmu
->type
);
6073 free_percpu(pmu
->pmu_disable_count
);
6077 void perf_pmu_unregister(struct pmu
*pmu
)
6079 mutex_lock(&pmus_lock
);
6080 list_del_rcu(&pmu
->entry
);
6081 mutex_unlock(&pmus_lock
);
6084 * We dereference the pmu list under both SRCU and regular RCU, so
6085 * synchronize against both of those.
6087 synchronize_srcu(&pmus_srcu
);
6090 free_percpu(pmu
->pmu_disable_count
);
6091 if (pmu
->type
>= PERF_TYPE_MAX
)
6092 idr_remove(&pmu_idr
, pmu
->type
);
6093 device_del(pmu
->dev
);
6094 put_device(pmu
->dev
);
6095 free_pmu_context(pmu
);
6098 struct pmu
*perf_init_event(struct perf_event
*event
)
6100 struct pmu
*pmu
= NULL
;
6104 idx
= srcu_read_lock(&pmus_srcu
);
6107 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
6110 ret
= pmu
->event_init(event
);
6116 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6117 ret
= pmu
->event_init(event
);
6121 if (ret
!= -ENOENT
) {
6126 pmu
= ERR_PTR(-ENOENT
);
6128 srcu_read_unlock(&pmus_srcu
, idx
);
6134 * Allocate and initialize a event structure
6136 static struct perf_event
*
6137 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
6138 struct task_struct
*task
,
6139 struct perf_event
*group_leader
,
6140 struct perf_event
*parent_event
,
6141 perf_overflow_handler_t overflow_handler
)
6144 struct perf_event
*event
;
6145 struct hw_perf_event
*hwc
;
6148 if ((unsigned)cpu
>= nr_cpu_ids
) {
6149 if (!task
|| cpu
!= -1)
6150 return ERR_PTR(-EINVAL
);
6153 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
6155 return ERR_PTR(-ENOMEM
);
6158 * Single events are their own group leaders, with an
6159 * empty sibling list:
6162 group_leader
= event
;
6164 mutex_init(&event
->child_mutex
);
6165 INIT_LIST_HEAD(&event
->child_list
);
6167 INIT_LIST_HEAD(&event
->group_entry
);
6168 INIT_LIST_HEAD(&event
->event_entry
);
6169 INIT_LIST_HEAD(&event
->sibling_list
);
6170 init_waitqueue_head(&event
->waitq
);
6171 init_irq_work(&event
->pending
, perf_pending_event
);
6173 mutex_init(&event
->mmap_mutex
);
6176 event
->attr
= *attr
;
6177 event
->group_leader
= group_leader
;
6181 event
->parent
= parent_event
;
6183 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
6184 event
->id
= atomic64_inc_return(&perf_event_id
);
6186 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6189 event
->attach_state
= PERF_ATTACH_TASK
;
6190 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6192 * hw_breakpoint is a bit difficult here..
6194 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
6195 event
->hw
.bp_target
= task
;
6199 if (!overflow_handler
&& parent_event
)
6200 overflow_handler
= parent_event
->overflow_handler
;
6202 event
->overflow_handler
= overflow_handler
;
6205 event
->state
= PERF_EVENT_STATE_OFF
;
6210 hwc
->sample_period
= attr
->sample_period
;
6211 if (attr
->freq
&& attr
->sample_freq
)
6212 hwc
->sample_period
= 1;
6213 hwc
->last_period
= hwc
->sample_period
;
6215 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6218 * we currently do not support PERF_FORMAT_GROUP on inherited events
6220 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
6223 pmu
= perf_init_event(event
);
6229 else if (IS_ERR(pmu
))
6234 put_pid_ns(event
->ns
);
6236 return ERR_PTR(err
);
6241 if (!event
->parent
) {
6242 if (event
->attach_state
& PERF_ATTACH_TASK
)
6243 jump_label_inc(&perf_sched_events
);
6244 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
6245 atomic_inc(&nr_mmap_events
);
6246 if (event
->attr
.comm
)
6247 atomic_inc(&nr_comm_events
);
6248 if (event
->attr
.task
)
6249 atomic_inc(&nr_task_events
);
6250 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6251 err
= get_callchain_buffers();
6254 return ERR_PTR(err
);
6262 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6263 struct perf_event_attr
*attr
)
6268 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6272 * zero the full structure, so that a short copy will be nice.
6274 memset(attr
, 0, sizeof(*attr
));
6276 ret
= get_user(size
, &uattr
->size
);
6280 if (size
> PAGE_SIZE
) /* silly large */
6283 if (!size
) /* abi compat */
6284 size
= PERF_ATTR_SIZE_VER0
;
6286 if (size
< PERF_ATTR_SIZE_VER0
)
6290 * If we're handed a bigger struct than we know of,
6291 * ensure all the unknown bits are 0 - i.e. new
6292 * user-space does not rely on any kernel feature
6293 * extensions we dont know about yet.
6295 if (size
> sizeof(*attr
)) {
6296 unsigned char __user
*addr
;
6297 unsigned char __user
*end
;
6300 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6301 end
= (void __user
*)uattr
+ size
;
6303 for (; addr
< end
; addr
++) {
6304 ret
= get_user(val
, addr
);
6310 size
= sizeof(*attr
);
6313 ret
= copy_from_user(attr
, uattr
, size
);
6318 * If the type exists, the corresponding creation will verify
6321 if (attr
->type
>= PERF_TYPE_MAX
)
6324 if (attr
->__reserved_1
)
6327 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6330 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6337 put_user(sizeof(*attr
), &uattr
->size
);
6343 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
6345 struct perf_buffer
*buffer
= NULL
, *old_buffer
= NULL
;
6351 /* don't allow circular references */
6352 if (event
== output_event
)
6356 * Don't allow cross-cpu buffers
6358 if (output_event
->cpu
!= event
->cpu
)
6362 * If its not a per-cpu buffer, it must be the same task.
6364 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
6368 mutex_lock(&event
->mmap_mutex
);
6369 /* Can't redirect output if we've got an active mmap() */
6370 if (atomic_read(&event
->mmap_count
))
6374 /* get the buffer we want to redirect to */
6375 buffer
= perf_buffer_get(output_event
);
6380 old_buffer
= event
->buffer
;
6381 rcu_assign_pointer(event
->buffer
, buffer
);
6384 mutex_unlock(&event
->mmap_mutex
);
6387 perf_buffer_put(old_buffer
);
6393 * sys_perf_event_open - open a performance event, associate it to a task/cpu
6395 * @attr_uptr: event_id type attributes for monitoring/sampling
6398 * @group_fd: group leader event fd
6400 SYSCALL_DEFINE5(perf_event_open
,
6401 struct perf_event_attr __user
*, attr_uptr
,
6402 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
6404 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
6405 struct perf_event
*event
, *sibling
;
6406 struct perf_event_attr attr
;
6407 struct perf_event_context
*ctx
;
6408 struct file
*event_file
= NULL
;
6409 struct file
*group_file
= NULL
;
6410 struct task_struct
*task
= NULL
;
6414 int fput_needed
= 0;
6417 /* for future expandability... */
6418 if (flags
& ~PERF_FLAG_ALL
)
6421 err
= perf_copy_attr(attr_uptr
, &attr
);
6425 if (!attr
.exclude_kernel
) {
6426 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6431 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
6436 * In cgroup mode, the pid argument is used to pass the fd
6437 * opened to the cgroup directory in cgroupfs. The cpu argument
6438 * designates the cpu on which to monitor threads from that
6441 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
6444 event_fd
= get_unused_fd_flags(O_RDWR
);
6448 if (group_fd
!= -1) {
6449 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
6450 if (IS_ERR(group_leader
)) {
6451 err
= PTR_ERR(group_leader
);
6454 group_file
= group_leader
->filp
;
6455 if (flags
& PERF_FLAG_FD_OUTPUT
)
6456 output_event
= group_leader
;
6457 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6458 group_leader
= NULL
;
6461 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6462 task
= find_lively_task_by_vpid(pid
);
6464 err
= PTR_ERR(task
);
6469 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
, NULL
);
6470 if (IS_ERR(event
)) {
6471 err
= PTR_ERR(event
);
6475 if (flags
& PERF_FLAG_PID_CGROUP
) {
6476 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6481 * - that has cgroup constraint on event->cpu
6482 * - that may need work on context switch
6484 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
6485 jump_label_inc(&perf_sched_events
);
6489 * Special case software events and allow them to be part of
6490 * any hardware group.
6495 (is_software_event(event
) != is_software_event(group_leader
))) {
6496 if (is_software_event(event
)) {
6498 * If event and group_leader are not both a software
6499 * event, and event is, then group leader is not.
6501 * Allow the addition of software events to !software
6502 * groups, this is safe because software events never
6505 pmu
= group_leader
->pmu
;
6506 } else if (is_software_event(group_leader
) &&
6507 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6509 * In case the group is a pure software group, and we
6510 * try to add a hardware event, move the whole group to
6511 * the hardware context.
6518 * Get the target context (task or percpu):
6520 ctx
= find_get_context(pmu
, task
, cpu
);
6527 put_task_struct(task
);
6532 * Look up the group leader (we will attach this event to it):
6538 * Do not allow a recursive hierarchy (this new sibling
6539 * becoming part of another group-sibling):
6541 if (group_leader
->group_leader
!= group_leader
)
6544 * Do not allow to attach to a group in a different
6545 * task or CPU context:
6548 if (group_leader
->ctx
->type
!= ctx
->type
)
6551 if (group_leader
->ctx
!= ctx
)
6556 * Only a group leader can be exclusive or pinned
6558 if (attr
.exclusive
|| attr
.pinned
)
6563 err
= perf_event_set_output(event
, output_event
);
6568 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6569 if (IS_ERR(event_file
)) {
6570 err
= PTR_ERR(event_file
);
6575 struct perf_event_context
*gctx
= group_leader
->ctx
;
6577 mutex_lock(&gctx
->mutex
);
6578 perf_remove_from_context(group_leader
);
6579 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6581 perf_remove_from_context(sibling
);
6584 mutex_unlock(&gctx
->mutex
);
6588 event
->filp
= event_file
;
6589 WARN_ON_ONCE(ctx
->parent_ctx
);
6590 mutex_lock(&ctx
->mutex
);
6593 perf_install_in_context(ctx
, group_leader
, cpu
);
6595 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6597 perf_install_in_context(ctx
, sibling
, cpu
);
6602 perf_install_in_context(ctx
, event
, cpu
);
6604 perf_unpin_context(ctx
);
6605 mutex_unlock(&ctx
->mutex
);
6607 event
->owner
= current
;
6609 mutex_lock(¤t
->perf_event_mutex
);
6610 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6611 mutex_unlock(¤t
->perf_event_mutex
);
6614 * Precalculate sample_data sizes
6616 perf_event__header_size(event
);
6617 perf_event__id_header_size(event
);
6620 * Drop the reference on the group_event after placing the
6621 * new event on the sibling_list. This ensures destruction
6622 * of the group leader will find the pointer to itself in
6623 * perf_group_detach().
6625 fput_light(group_file
, fput_needed
);
6626 fd_install(event_fd
, event_file
);
6630 perf_unpin_context(ctx
);
6636 put_task_struct(task
);
6638 fput_light(group_file
, fput_needed
);
6640 put_unused_fd(event_fd
);
6645 * perf_event_create_kernel_counter
6647 * @attr: attributes of the counter to create
6648 * @cpu: cpu in which the counter is bound
6649 * @task: task to profile (NULL for percpu)
6652 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6653 struct task_struct
*task
,
6654 perf_overflow_handler_t overflow_handler
)
6656 struct perf_event_context
*ctx
;
6657 struct perf_event
*event
;
6661 * Get the target context (task or percpu):
6664 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
, overflow_handler
);
6665 if (IS_ERR(event
)) {
6666 err
= PTR_ERR(event
);
6670 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6677 WARN_ON_ONCE(ctx
->parent_ctx
);
6678 mutex_lock(&ctx
->mutex
);
6679 perf_install_in_context(ctx
, event
, cpu
);
6681 perf_unpin_context(ctx
);
6682 mutex_unlock(&ctx
->mutex
);
6689 return ERR_PTR(err
);
6691 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6693 static void sync_child_event(struct perf_event
*child_event
,
6694 struct task_struct
*child
)
6696 struct perf_event
*parent_event
= child_event
->parent
;
6699 if (child_event
->attr
.inherit_stat
)
6700 perf_event_read_event(child_event
, child
);
6702 child_val
= perf_event_count(child_event
);
6705 * Add back the child's count to the parent's count:
6707 atomic64_add(child_val
, &parent_event
->child_count
);
6708 atomic64_add(child_event
->total_time_enabled
,
6709 &parent_event
->child_total_time_enabled
);
6710 atomic64_add(child_event
->total_time_running
,
6711 &parent_event
->child_total_time_running
);
6714 * Remove this event from the parent's list
6716 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6717 mutex_lock(&parent_event
->child_mutex
);
6718 list_del_init(&child_event
->child_list
);
6719 mutex_unlock(&parent_event
->child_mutex
);
6722 * Release the parent event, if this was the last
6725 fput(parent_event
->filp
);
6729 __perf_event_exit_task(struct perf_event
*child_event
,
6730 struct perf_event_context
*child_ctx
,
6731 struct task_struct
*child
)
6733 if (child_event
->parent
) {
6734 raw_spin_lock_irq(&child_ctx
->lock
);
6735 perf_group_detach(child_event
);
6736 raw_spin_unlock_irq(&child_ctx
->lock
);
6739 perf_remove_from_context(child_event
);
6742 * It can happen that the parent exits first, and has events
6743 * that are still around due to the child reference. These
6744 * events need to be zapped.
6746 if (child_event
->parent
) {
6747 sync_child_event(child_event
, child
);
6748 free_event(child_event
);
6752 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6754 struct perf_event
*child_event
, *tmp
;
6755 struct perf_event_context
*child_ctx
;
6756 unsigned long flags
;
6758 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6759 perf_event_task(child
, NULL
, 0);
6763 local_irq_save(flags
);
6765 * We can't reschedule here because interrupts are disabled,
6766 * and either child is current or it is a task that can't be
6767 * scheduled, so we are now safe from rescheduling changing
6770 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6773 * Take the context lock here so that if find_get_context is
6774 * reading child->perf_event_ctxp, we wait until it has
6775 * incremented the context's refcount before we do put_ctx below.
6777 raw_spin_lock(&child_ctx
->lock
);
6778 task_ctx_sched_out(child_ctx
);
6779 child
->perf_event_ctxp
[ctxn
] = NULL
;
6781 * If this context is a clone; unclone it so it can't get
6782 * swapped to another process while we're removing all
6783 * the events from it.
6785 unclone_ctx(child_ctx
);
6786 update_context_time(child_ctx
);
6787 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6790 * Report the task dead after unscheduling the events so that we
6791 * won't get any samples after PERF_RECORD_EXIT. We can however still
6792 * get a few PERF_RECORD_READ events.
6794 perf_event_task(child
, child_ctx
, 0);
6797 * We can recurse on the same lock type through:
6799 * __perf_event_exit_task()
6800 * sync_child_event()
6801 * fput(parent_event->filp)
6803 * mutex_lock(&ctx->mutex)
6805 * But since its the parent context it won't be the same instance.
6807 mutex_lock(&child_ctx
->mutex
);
6810 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6812 __perf_event_exit_task(child_event
, child_ctx
, child
);
6814 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6816 __perf_event_exit_task(child_event
, child_ctx
, child
);
6819 * If the last event was a group event, it will have appended all
6820 * its siblings to the list, but we obtained 'tmp' before that which
6821 * will still point to the list head terminating the iteration.
6823 if (!list_empty(&child_ctx
->pinned_groups
) ||
6824 !list_empty(&child_ctx
->flexible_groups
))
6827 mutex_unlock(&child_ctx
->mutex
);
6833 * When a child task exits, feed back event values to parent events.
6835 void perf_event_exit_task(struct task_struct
*child
)
6837 struct perf_event
*event
, *tmp
;
6840 mutex_lock(&child
->perf_event_mutex
);
6841 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6843 list_del_init(&event
->owner_entry
);
6846 * Ensure the list deletion is visible before we clear
6847 * the owner, closes a race against perf_release() where
6848 * we need to serialize on the owner->perf_event_mutex.
6851 event
->owner
= NULL
;
6853 mutex_unlock(&child
->perf_event_mutex
);
6855 for_each_task_context_nr(ctxn
)
6856 perf_event_exit_task_context(child
, ctxn
);
6859 static void perf_free_event(struct perf_event
*event
,
6860 struct perf_event_context
*ctx
)
6862 struct perf_event
*parent
= event
->parent
;
6864 if (WARN_ON_ONCE(!parent
))
6867 mutex_lock(&parent
->child_mutex
);
6868 list_del_init(&event
->child_list
);
6869 mutex_unlock(&parent
->child_mutex
);
6873 perf_group_detach(event
);
6874 list_del_event(event
, ctx
);
6879 * free an unexposed, unused context as created by inheritance by
6880 * perf_event_init_task below, used by fork() in case of fail.
6882 void perf_event_free_task(struct task_struct
*task
)
6884 struct perf_event_context
*ctx
;
6885 struct perf_event
*event
, *tmp
;
6888 for_each_task_context_nr(ctxn
) {
6889 ctx
= task
->perf_event_ctxp
[ctxn
];
6893 mutex_lock(&ctx
->mutex
);
6895 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6897 perf_free_event(event
, ctx
);
6899 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6901 perf_free_event(event
, ctx
);
6903 if (!list_empty(&ctx
->pinned_groups
) ||
6904 !list_empty(&ctx
->flexible_groups
))
6907 mutex_unlock(&ctx
->mutex
);
6913 void perf_event_delayed_put(struct task_struct
*task
)
6917 for_each_task_context_nr(ctxn
)
6918 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6922 * inherit a event from parent task to child task:
6924 static struct perf_event
*
6925 inherit_event(struct perf_event
*parent_event
,
6926 struct task_struct
*parent
,
6927 struct perf_event_context
*parent_ctx
,
6928 struct task_struct
*child
,
6929 struct perf_event
*group_leader
,
6930 struct perf_event_context
*child_ctx
)
6932 struct perf_event
*child_event
;
6933 unsigned long flags
;
6936 * Instead of creating recursive hierarchies of events,
6937 * we link inherited events back to the original parent,
6938 * which has a filp for sure, which we use as the reference
6941 if (parent_event
->parent
)
6942 parent_event
= parent_event
->parent
;
6944 child_event
= perf_event_alloc(&parent_event
->attr
,
6947 group_leader
, parent_event
,
6949 if (IS_ERR(child_event
))
6954 * Make the child state follow the state of the parent event,
6955 * not its attr.disabled bit. We hold the parent's mutex,
6956 * so we won't race with perf_event_{en, dis}able_family.
6958 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6959 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6961 child_event
->state
= PERF_EVENT_STATE_OFF
;
6963 if (parent_event
->attr
.freq
) {
6964 u64 sample_period
= parent_event
->hw
.sample_period
;
6965 struct hw_perf_event
*hwc
= &child_event
->hw
;
6967 hwc
->sample_period
= sample_period
;
6968 hwc
->last_period
= sample_period
;
6970 local64_set(&hwc
->period_left
, sample_period
);
6973 child_event
->ctx
= child_ctx
;
6974 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6977 * Precalculate sample_data sizes
6979 perf_event__header_size(child_event
);
6980 perf_event__id_header_size(child_event
);
6983 * Link it up in the child's context:
6985 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6986 add_event_to_ctx(child_event
, child_ctx
);
6987 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6990 * Get a reference to the parent filp - we will fput it
6991 * when the child event exits. This is safe to do because
6992 * we are in the parent and we know that the filp still
6993 * exists and has a nonzero count:
6995 atomic_long_inc(&parent_event
->filp
->f_count
);
6998 * Link this into the parent event's child list
7000 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7001 mutex_lock(&parent_event
->child_mutex
);
7002 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
7003 mutex_unlock(&parent_event
->child_mutex
);
7008 static int inherit_group(struct perf_event
*parent_event
,
7009 struct task_struct
*parent
,
7010 struct perf_event_context
*parent_ctx
,
7011 struct task_struct
*child
,
7012 struct perf_event_context
*child_ctx
)
7014 struct perf_event
*leader
;
7015 struct perf_event
*sub
;
7016 struct perf_event
*child_ctr
;
7018 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
7019 child
, NULL
, child_ctx
);
7021 return PTR_ERR(leader
);
7022 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
7023 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
7024 child
, leader
, child_ctx
);
7025 if (IS_ERR(child_ctr
))
7026 return PTR_ERR(child_ctr
);
7032 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
7033 struct perf_event_context
*parent_ctx
,
7034 struct task_struct
*child
, int ctxn
,
7038 struct perf_event_context
*child_ctx
;
7040 if (!event
->attr
.inherit
) {
7045 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7048 * This is executed from the parent task context, so
7049 * inherit events that have been marked for cloning.
7050 * First allocate and initialize a context for the
7054 child_ctx
= alloc_perf_context(event
->pmu
, child
);
7058 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
7061 ret
= inherit_group(event
, parent
, parent_ctx
,
7071 * Initialize the perf_event context in task_struct
7073 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
7075 struct perf_event_context
*child_ctx
, *parent_ctx
;
7076 struct perf_event_context
*cloned_ctx
;
7077 struct perf_event
*event
;
7078 struct task_struct
*parent
= current
;
7079 int inherited_all
= 1;
7080 unsigned long flags
;
7083 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
7087 * If the parent's context is a clone, pin it so it won't get
7090 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
7093 * No need to check if parent_ctx != NULL here; since we saw
7094 * it non-NULL earlier, the only reason for it to become NULL
7095 * is if we exit, and since we're currently in the middle of
7096 * a fork we can't be exiting at the same time.
7100 * Lock the parent list. No need to lock the child - not PID
7101 * hashed yet and not running, so nobody can access it.
7103 mutex_lock(&parent_ctx
->mutex
);
7106 * We dont have to disable NMIs - we are only looking at
7107 * the list, not manipulating it:
7109 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
7110 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7111 child
, ctxn
, &inherited_all
);
7117 * We can't hold ctx->lock when iterating the ->flexible_group list due
7118 * to allocations, but we need to prevent rotation because
7119 * rotate_ctx() will change the list from interrupt context.
7121 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7122 parent_ctx
->rotate_disable
= 1;
7123 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7125 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
7126 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7127 child
, ctxn
, &inherited_all
);
7132 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7133 parent_ctx
->rotate_disable
= 0;
7135 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7137 if (child_ctx
&& inherited_all
) {
7139 * Mark the child context as a clone of the parent
7140 * context, or of whatever the parent is a clone of.
7142 * Note that if the parent is a clone, the holding of
7143 * parent_ctx->lock avoids it from being uncloned.
7145 cloned_ctx
= parent_ctx
->parent_ctx
;
7147 child_ctx
->parent_ctx
= cloned_ctx
;
7148 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
7150 child_ctx
->parent_ctx
= parent_ctx
;
7151 child_ctx
->parent_gen
= parent_ctx
->generation
;
7153 get_ctx(child_ctx
->parent_ctx
);
7156 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7157 mutex_unlock(&parent_ctx
->mutex
);
7159 perf_unpin_context(parent_ctx
);
7160 put_ctx(parent_ctx
);
7166 * Initialize the perf_event context in task_struct
7168 int perf_event_init_task(struct task_struct
*child
)
7172 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7173 mutex_init(&child
->perf_event_mutex
);
7174 INIT_LIST_HEAD(&child
->perf_event_list
);
7176 for_each_task_context_nr(ctxn
) {
7177 ret
= perf_event_init_context(child
, ctxn
);
7185 static void __init
perf_event_init_all_cpus(void)
7187 struct swevent_htable
*swhash
;
7190 for_each_possible_cpu(cpu
) {
7191 swhash
= &per_cpu(swevent_htable
, cpu
);
7192 mutex_init(&swhash
->hlist_mutex
);
7193 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7197 static void __cpuinit
perf_event_init_cpu(int cpu
)
7199 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7201 mutex_lock(&swhash
->hlist_mutex
);
7202 if (swhash
->hlist_refcount
> 0) {
7203 struct swevent_hlist
*hlist
;
7205 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7207 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7209 mutex_unlock(&swhash
->hlist_mutex
);
7212 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7213 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7215 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7217 WARN_ON(!irqs_disabled());
7219 list_del_init(&cpuctx
->rotation_list
);
7222 static void __perf_event_exit_context(void *__info
)
7224 struct perf_event_context
*ctx
= __info
;
7225 struct perf_event
*event
, *tmp
;
7227 perf_pmu_rotate_stop(ctx
->pmu
);
7229 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
7230 __perf_remove_from_context(event
);
7231 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
7232 __perf_remove_from_context(event
);
7235 static void perf_event_exit_cpu_context(int cpu
)
7237 struct perf_event_context
*ctx
;
7241 idx
= srcu_read_lock(&pmus_srcu
);
7242 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7243 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
7245 mutex_lock(&ctx
->mutex
);
7246 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
7247 mutex_unlock(&ctx
->mutex
);
7249 srcu_read_unlock(&pmus_srcu
, idx
);
7252 static void perf_event_exit_cpu(int cpu
)
7254 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7256 mutex_lock(&swhash
->hlist_mutex
);
7257 swevent_hlist_release(swhash
);
7258 mutex_unlock(&swhash
->hlist_mutex
);
7260 perf_event_exit_cpu_context(cpu
);
7263 static inline void perf_event_exit_cpu(int cpu
) { }
7267 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
7271 for_each_online_cpu(cpu
)
7272 perf_event_exit_cpu(cpu
);
7278 * Run the perf reboot notifier at the very last possible moment so that
7279 * the generic watchdog code runs as long as possible.
7281 static struct notifier_block perf_reboot_notifier
= {
7282 .notifier_call
= perf_reboot
,
7283 .priority
= INT_MIN
,
7286 static int __cpuinit
7287 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
7289 unsigned int cpu
= (long)hcpu
;
7291 switch (action
& ~CPU_TASKS_FROZEN
) {
7293 case CPU_UP_PREPARE
:
7294 case CPU_DOWN_FAILED
:
7295 perf_event_init_cpu(cpu
);
7298 case CPU_UP_CANCELED
:
7299 case CPU_DOWN_PREPARE
:
7300 perf_event_exit_cpu(cpu
);
7310 void __init
perf_event_init(void)
7316 perf_event_init_all_cpus();
7317 init_srcu_struct(&pmus_srcu
);
7318 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
7319 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
7320 perf_pmu_register(&perf_task_clock
, NULL
, -1);
7322 perf_cpu_notifier(perf_cpu_notify
);
7323 register_reboot_notifier(&perf_reboot_notifier
);
7325 ret
= init_hw_breakpoint();
7326 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
7329 static int __init
perf_event_sysfs_init(void)
7334 mutex_lock(&pmus_lock
);
7336 ret
= bus_register(&pmu_bus
);
7340 list_for_each_entry(pmu
, &pmus
, entry
) {
7341 if (!pmu
->name
|| pmu
->type
< 0)
7344 ret
= pmu_dev_alloc(pmu
);
7345 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
7347 pmu_bus_running
= 1;
7351 mutex_unlock(&pmus_lock
);
7355 device_initcall(perf_event_sysfs_init
);
7357 #ifdef CONFIG_CGROUP_PERF
7358 static struct cgroup_subsys_state
*perf_cgroup_create(
7359 struct cgroup_subsys
*ss
, struct cgroup
*cont
)
7361 struct perf_cgroup
*jc
;
7363 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
7365 return ERR_PTR(-ENOMEM
);
7367 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
7370 return ERR_PTR(-ENOMEM
);
7376 static void perf_cgroup_destroy(struct cgroup_subsys
*ss
,
7377 struct cgroup
*cont
)
7379 struct perf_cgroup
*jc
;
7380 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
7381 struct perf_cgroup
, css
);
7382 free_percpu(jc
->info
);
7386 static int __perf_cgroup_move(void *info
)
7388 struct task_struct
*task
= info
;
7389 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
7393 static void perf_cgroup_move(struct task_struct
*task
)
7395 task_function_call(task
, __perf_cgroup_move
, task
);
7398 static void perf_cgroup_attach(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
7399 struct cgroup
*old_cgrp
, struct task_struct
*task
,
7402 perf_cgroup_move(task
);
7404 struct task_struct
*c
;
7406 list_for_each_entry_rcu(c
, &task
->thread_group
, thread_group
) {
7407 perf_cgroup_move(c
);
7413 static void perf_cgroup_exit(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
7414 struct cgroup
*old_cgrp
, struct task_struct
*task
)
7417 * cgroup_exit() is called in the copy_process() failure path.
7418 * Ignore this case since the task hasn't ran yet, this avoids
7419 * trying to poke a half freed task state from generic code.
7421 if (!(task
->flags
& PF_EXITING
))
7424 perf_cgroup_move(task
);
7427 struct cgroup_subsys perf_subsys
= {
7428 .name
= "perf_event",
7429 .subsys_id
= perf_subsys_id
,
7430 .create
= perf_cgroup_create
,
7431 .destroy
= perf_cgroup_destroy
,
7432 .exit
= perf_cgroup_exit
,
7433 .attach
= perf_cgroup_attach
,
7435 #endif /* CONFIG_CGROUP_PERF */