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/export.h>
29 #include <linux/vmalloc.h>
30 #include <linux/hardirq.h>
31 #include <linux/rculist.h>
32 #include <linux/uaccess.h>
33 #include <linux/syscalls.h>
34 #include <linux/anon_inodes.h>
35 #include <linux/kernel_stat.h>
36 #include <linux/perf_event.h>
37 #include <linux/ftrace_event.h>
38 #include <linux/hw_breakpoint.h>
42 #include <asm/irq_regs.h>
44 struct remote_function_call
{
45 struct task_struct
*p
;
46 int (*func
)(void *info
);
51 static void remote_function(void *data
)
53 struct remote_function_call
*tfc
= data
;
54 struct task_struct
*p
= tfc
->p
;
58 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
62 tfc
->ret
= tfc
->func(tfc
->info
);
66 * task_function_call - call a function on the cpu on which a task runs
67 * @p: the task to evaluate
68 * @func: the function to be called
69 * @info: the function call argument
71 * Calls the function @func when the task is currently running. This might
72 * be on the current CPU, which just calls the function directly
74 * returns: @func return value, or
75 * -ESRCH - when the process isn't running
76 * -EAGAIN - when the process moved away
79 task_function_call(struct task_struct
*p
, int (*func
) (void *info
), void *info
)
81 struct remote_function_call data
= {
85 .ret
= -ESRCH
, /* No such (running) process */
89 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
95 * cpu_function_call - call a function on the cpu
96 * @func: the function to be called
97 * @info: the function call argument
99 * Calls the function @func on the remote cpu.
101 * returns: @func return value or -ENXIO when the cpu is offline
103 static int cpu_function_call(int cpu
, int (*func
) (void *info
), void *info
)
105 struct remote_function_call data
= {
109 .ret
= -ENXIO
, /* No such CPU */
112 smp_call_function_single(cpu
, remote_function
, &data
, 1);
117 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
118 PERF_FLAG_FD_OUTPUT |\
119 PERF_FLAG_PID_CGROUP)
122 * branch priv levels that need permission checks
124 #define PERF_SAMPLE_BRANCH_PERM_PLM \
125 (PERF_SAMPLE_BRANCH_KERNEL |\
126 PERF_SAMPLE_BRANCH_HV)
129 EVENT_FLEXIBLE
= 0x1,
131 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
135 * perf_sched_events : >0 events exist
136 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
138 struct static_key_deferred perf_sched_events __read_mostly
;
139 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
140 static DEFINE_PER_CPU(atomic_t
, perf_branch_stack_events
);
142 static atomic_t nr_mmap_events __read_mostly
;
143 static atomic_t nr_comm_events __read_mostly
;
144 static atomic_t nr_task_events __read_mostly
;
146 static LIST_HEAD(pmus
);
147 static DEFINE_MUTEX(pmus_lock
);
148 static struct srcu_struct pmus_srcu
;
151 * perf event paranoia level:
152 * -1 - not paranoid at all
153 * 0 - disallow raw tracepoint access for unpriv
154 * 1 - disallow cpu events for unpriv
155 * 2 - disallow kernel profiling for unpriv
157 int sysctl_perf_event_paranoid __read_mostly
= 1;
159 /* Minimum for 512 kiB + 1 user control page */
160 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
163 * max perf event sample rate
165 #define DEFAULT_MAX_SAMPLE_RATE 100000
166 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
167 static int max_samples_per_tick __read_mostly
=
168 DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
170 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
171 void __user
*buffer
, size_t *lenp
,
174 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
179 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
184 static atomic64_t perf_event_id
;
186 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
187 enum event_type_t event_type
);
189 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
190 enum event_type_t event_type
,
191 struct task_struct
*task
);
193 static void update_context_time(struct perf_event_context
*ctx
);
194 static u64
perf_event_time(struct perf_event
*event
);
196 static void ring_buffer_attach(struct perf_event
*event
,
197 struct ring_buffer
*rb
);
199 void __weak
perf_event_print_debug(void) { }
201 extern __weak
const char *perf_pmu_name(void)
206 static inline u64
perf_clock(void)
208 return local_clock();
211 static inline struct perf_cpu_context
*
212 __get_cpu_context(struct perf_event_context
*ctx
)
214 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
217 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
218 struct perf_event_context
*ctx
)
220 raw_spin_lock(&cpuctx
->ctx
.lock
);
222 raw_spin_lock(&ctx
->lock
);
225 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
226 struct perf_event_context
*ctx
)
229 raw_spin_unlock(&ctx
->lock
);
230 raw_spin_unlock(&cpuctx
->ctx
.lock
);
233 #ifdef CONFIG_CGROUP_PERF
236 * Must ensure cgroup is pinned (css_get) before calling
237 * this function. In other words, we cannot call this function
238 * if there is no cgroup event for the current CPU context.
240 static inline struct perf_cgroup
*
241 perf_cgroup_from_task(struct task_struct
*task
)
243 return container_of(task_subsys_state(task
, perf_subsys_id
),
244 struct perf_cgroup
, css
);
248 perf_cgroup_match(struct perf_event
*event
)
250 struct perf_event_context
*ctx
= event
->ctx
;
251 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
253 return !event
->cgrp
|| event
->cgrp
== cpuctx
->cgrp
;
256 static inline bool perf_tryget_cgroup(struct perf_event
*event
)
258 return css_tryget(&event
->cgrp
->css
);
261 static inline void perf_put_cgroup(struct perf_event
*event
)
263 css_put(&event
->cgrp
->css
);
266 static inline void perf_detach_cgroup(struct perf_event
*event
)
268 perf_put_cgroup(event
);
272 static inline int is_cgroup_event(struct perf_event
*event
)
274 return event
->cgrp
!= NULL
;
277 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
279 struct perf_cgroup_info
*t
;
281 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
285 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
287 struct perf_cgroup_info
*info
;
292 info
= this_cpu_ptr(cgrp
->info
);
294 info
->time
+= now
- info
->timestamp
;
295 info
->timestamp
= now
;
298 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
300 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
302 __update_cgrp_time(cgrp_out
);
305 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
307 struct perf_cgroup
*cgrp
;
310 * ensure we access cgroup data only when needed and
311 * when we know the cgroup is pinned (css_get)
313 if (!is_cgroup_event(event
))
316 cgrp
= perf_cgroup_from_task(current
);
318 * Do not update time when cgroup is not active
320 if (cgrp
== event
->cgrp
)
321 __update_cgrp_time(event
->cgrp
);
325 perf_cgroup_set_timestamp(struct task_struct
*task
,
326 struct perf_event_context
*ctx
)
328 struct perf_cgroup
*cgrp
;
329 struct perf_cgroup_info
*info
;
332 * ctx->lock held by caller
333 * ensure we do not access cgroup data
334 * unless we have the cgroup pinned (css_get)
336 if (!task
|| !ctx
->nr_cgroups
)
339 cgrp
= perf_cgroup_from_task(task
);
340 info
= this_cpu_ptr(cgrp
->info
);
341 info
->timestamp
= ctx
->timestamp
;
344 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
345 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
348 * reschedule events based on the cgroup constraint of task.
350 * mode SWOUT : schedule out everything
351 * mode SWIN : schedule in based on cgroup for next
353 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
355 struct perf_cpu_context
*cpuctx
;
360 * disable interrupts to avoid geting nr_cgroup
361 * changes via __perf_event_disable(). Also
364 local_irq_save(flags
);
367 * we reschedule only in the presence of cgroup
368 * constrained events.
372 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
373 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
376 * perf_cgroup_events says at least one
377 * context on this CPU has cgroup events.
379 * ctx->nr_cgroups reports the number of cgroup
380 * events for a context.
382 if (cpuctx
->ctx
.nr_cgroups
> 0) {
383 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
384 perf_pmu_disable(cpuctx
->ctx
.pmu
);
386 if (mode
& PERF_CGROUP_SWOUT
) {
387 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
389 * must not be done before ctxswout due
390 * to event_filter_match() in event_sched_out()
395 if (mode
& PERF_CGROUP_SWIN
) {
396 WARN_ON_ONCE(cpuctx
->cgrp
);
397 /* set cgrp before ctxsw in to
398 * allow event_filter_match() to not
399 * have to pass task around
401 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
402 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
404 perf_pmu_enable(cpuctx
->ctx
.pmu
);
405 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
411 local_irq_restore(flags
);
414 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
415 struct task_struct
*next
)
417 struct perf_cgroup
*cgrp1
;
418 struct perf_cgroup
*cgrp2
= NULL
;
421 * we come here when we know perf_cgroup_events > 0
423 cgrp1
= perf_cgroup_from_task(task
);
426 * next is NULL when called from perf_event_enable_on_exec()
427 * that will systematically cause a cgroup_switch()
430 cgrp2
= perf_cgroup_from_task(next
);
433 * only schedule out current cgroup events if we know
434 * that we are switching to a different cgroup. Otherwise,
435 * do no touch the cgroup events.
438 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
441 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
442 struct task_struct
*task
)
444 struct perf_cgroup
*cgrp1
;
445 struct perf_cgroup
*cgrp2
= NULL
;
448 * we come here when we know perf_cgroup_events > 0
450 cgrp1
= perf_cgroup_from_task(task
);
452 /* prev can never be NULL */
453 cgrp2
= perf_cgroup_from_task(prev
);
456 * only need to schedule in cgroup events if we are changing
457 * cgroup during ctxsw. Cgroup events were not scheduled
458 * out of ctxsw out if that was not the case.
461 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
464 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
465 struct perf_event_attr
*attr
,
466 struct perf_event
*group_leader
)
468 struct perf_cgroup
*cgrp
;
469 struct cgroup_subsys_state
*css
;
471 int ret
= 0, fput_needed
;
473 file
= fget_light(fd
, &fput_needed
);
477 css
= cgroup_css_from_dir(file
, perf_subsys_id
);
483 cgrp
= container_of(css
, struct perf_cgroup
, css
);
486 /* must be done before we fput() the file */
487 if (!perf_tryget_cgroup(event
)) {
494 * all events in a group must monitor
495 * the same cgroup because a task belongs
496 * to only one perf cgroup at a time
498 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
499 perf_detach_cgroup(event
);
503 fput_light(file
, fput_needed
);
508 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
510 struct perf_cgroup_info
*t
;
511 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
512 event
->shadow_ctx_time
= now
- t
->timestamp
;
516 perf_cgroup_defer_enabled(struct perf_event
*event
)
519 * when the current task's perf cgroup does not match
520 * the event's, we need to remember to call the
521 * perf_mark_enable() function the first time a task with
522 * a matching perf cgroup is scheduled in.
524 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
525 event
->cgrp_defer_enabled
= 1;
529 perf_cgroup_mark_enabled(struct perf_event
*event
,
530 struct perf_event_context
*ctx
)
532 struct perf_event
*sub
;
533 u64 tstamp
= perf_event_time(event
);
535 if (!event
->cgrp_defer_enabled
)
538 event
->cgrp_defer_enabled
= 0;
540 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
541 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
542 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
543 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
544 sub
->cgrp_defer_enabled
= 0;
548 #else /* !CONFIG_CGROUP_PERF */
551 perf_cgroup_match(struct perf_event
*event
)
556 static inline void perf_detach_cgroup(struct perf_event
*event
)
559 static inline int is_cgroup_event(struct perf_event
*event
)
564 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
569 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
573 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
577 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
578 struct task_struct
*next
)
582 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
583 struct task_struct
*task
)
587 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
588 struct perf_event_attr
*attr
,
589 struct perf_event
*group_leader
)
595 perf_cgroup_set_timestamp(struct task_struct
*task
,
596 struct perf_event_context
*ctx
)
601 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
606 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
610 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
616 perf_cgroup_defer_enabled(struct perf_event
*event
)
621 perf_cgroup_mark_enabled(struct perf_event
*event
,
622 struct perf_event_context
*ctx
)
627 void perf_pmu_disable(struct pmu
*pmu
)
629 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
631 pmu
->pmu_disable(pmu
);
634 void perf_pmu_enable(struct pmu
*pmu
)
636 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
638 pmu
->pmu_enable(pmu
);
641 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
644 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
645 * because they're strictly cpu affine and rotate_start is called with IRQs
646 * disabled, while rotate_context is called from IRQ context.
648 static void perf_pmu_rotate_start(struct pmu
*pmu
)
650 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
651 struct list_head
*head
= &__get_cpu_var(rotation_list
);
653 WARN_ON(!irqs_disabled());
655 if (list_empty(&cpuctx
->rotation_list
))
656 list_add(&cpuctx
->rotation_list
, head
);
659 static void get_ctx(struct perf_event_context
*ctx
)
661 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
664 static void put_ctx(struct perf_event_context
*ctx
)
666 if (atomic_dec_and_test(&ctx
->refcount
)) {
668 put_ctx(ctx
->parent_ctx
);
670 put_task_struct(ctx
->task
);
671 kfree_rcu(ctx
, rcu_head
);
675 static void unclone_ctx(struct perf_event_context
*ctx
)
677 if (ctx
->parent_ctx
) {
678 put_ctx(ctx
->parent_ctx
);
679 ctx
->parent_ctx
= NULL
;
683 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
686 * only top level events have the pid namespace they were created in
689 event
= event
->parent
;
691 return task_tgid_nr_ns(p
, event
->ns
);
694 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
697 * only top level events have the pid namespace they were created in
700 event
= event
->parent
;
702 return task_pid_nr_ns(p
, event
->ns
);
706 * If we inherit events we want to return the parent event id
709 static u64
primary_event_id(struct perf_event
*event
)
714 id
= event
->parent
->id
;
720 * Get the perf_event_context for a task and lock it.
721 * This has to cope with with the fact that until it is locked,
722 * the context could get moved to another task.
724 static struct perf_event_context
*
725 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
727 struct perf_event_context
*ctx
;
731 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
734 * If this context is a clone of another, it might
735 * get swapped for another underneath us by
736 * perf_event_task_sched_out, though the
737 * rcu_read_lock() protects us from any context
738 * getting freed. Lock the context and check if it
739 * got swapped before we could get the lock, and retry
740 * if so. If we locked the right context, then it
741 * can't get swapped on us any more.
743 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
744 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
745 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
749 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
750 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
759 * Get the context for a task and increment its pin_count so it
760 * can't get swapped to another task. This also increments its
761 * reference count so that the context can't get freed.
763 static struct perf_event_context
*
764 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
766 struct perf_event_context
*ctx
;
769 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
772 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
777 static void perf_unpin_context(struct perf_event_context
*ctx
)
781 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
783 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
787 * Update the record of the current time in a context.
789 static void update_context_time(struct perf_event_context
*ctx
)
791 u64 now
= perf_clock();
793 ctx
->time
+= now
- ctx
->timestamp
;
794 ctx
->timestamp
= now
;
797 static u64
perf_event_time(struct perf_event
*event
)
799 struct perf_event_context
*ctx
= event
->ctx
;
801 if (is_cgroup_event(event
))
802 return perf_cgroup_event_time(event
);
804 return ctx
? ctx
->time
: 0;
808 * Update the total_time_enabled and total_time_running fields for a event.
809 * The caller of this function needs to hold the ctx->lock.
811 static void update_event_times(struct perf_event
*event
)
813 struct perf_event_context
*ctx
= event
->ctx
;
816 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
817 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
820 * in cgroup mode, time_enabled represents
821 * the time the event was enabled AND active
822 * tasks were in the monitored cgroup. This is
823 * independent of the activity of the context as
824 * there may be a mix of cgroup and non-cgroup events.
826 * That is why we treat cgroup events differently
829 if (is_cgroup_event(event
))
830 run_end
= perf_cgroup_event_time(event
);
831 else if (ctx
->is_active
)
834 run_end
= event
->tstamp_stopped
;
836 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
838 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
839 run_end
= event
->tstamp_stopped
;
841 run_end
= perf_event_time(event
);
843 event
->total_time_running
= run_end
- event
->tstamp_running
;
848 * Update total_time_enabled and total_time_running for all events in a group.
850 static void update_group_times(struct perf_event
*leader
)
852 struct perf_event
*event
;
854 update_event_times(leader
);
855 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
856 update_event_times(event
);
859 static struct list_head
*
860 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
862 if (event
->attr
.pinned
)
863 return &ctx
->pinned_groups
;
865 return &ctx
->flexible_groups
;
869 * Add a event from the lists for its context.
870 * Must be called with ctx->mutex and ctx->lock held.
873 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
875 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
876 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
879 * If we're a stand alone event or group leader, we go to the context
880 * list, group events are kept attached to the group so that
881 * perf_group_detach can, at all times, locate all siblings.
883 if (event
->group_leader
== event
) {
884 struct list_head
*list
;
886 if (is_software_event(event
))
887 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
889 list
= ctx_group_list(event
, ctx
);
890 list_add_tail(&event
->group_entry
, list
);
893 if (is_cgroup_event(event
))
896 if (has_branch_stack(event
))
897 ctx
->nr_branch_stack
++;
899 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
901 perf_pmu_rotate_start(ctx
->pmu
);
903 if (event
->attr
.inherit_stat
)
908 * Called at perf_event creation and when events are attached/detached from a
911 static void perf_event__read_size(struct perf_event
*event
)
913 int entry
= sizeof(u64
); /* value */
917 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
920 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
923 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
924 entry
+= sizeof(u64
);
926 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
927 nr
+= event
->group_leader
->nr_siblings
;
932 event
->read_size
= size
;
935 static void perf_event__header_size(struct perf_event
*event
)
937 struct perf_sample_data
*data
;
938 u64 sample_type
= event
->attr
.sample_type
;
941 perf_event__read_size(event
);
943 if (sample_type
& PERF_SAMPLE_IP
)
944 size
+= sizeof(data
->ip
);
946 if (sample_type
& PERF_SAMPLE_ADDR
)
947 size
+= sizeof(data
->addr
);
949 if (sample_type
& PERF_SAMPLE_PERIOD
)
950 size
+= sizeof(data
->period
);
952 if (sample_type
& PERF_SAMPLE_READ
)
953 size
+= event
->read_size
;
955 event
->header_size
= size
;
958 static void perf_event__id_header_size(struct perf_event
*event
)
960 struct perf_sample_data
*data
;
961 u64 sample_type
= event
->attr
.sample_type
;
964 if (sample_type
& PERF_SAMPLE_TID
)
965 size
+= sizeof(data
->tid_entry
);
967 if (sample_type
& PERF_SAMPLE_TIME
)
968 size
+= sizeof(data
->time
);
970 if (sample_type
& PERF_SAMPLE_ID
)
971 size
+= sizeof(data
->id
);
973 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
974 size
+= sizeof(data
->stream_id
);
976 if (sample_type
& PERF_SAMPLE_CPU
)
977 size
+= sizeof(data
->cpu_entry
);
979 event
->id_header_size
= size
;
982 static void perf_group_attach(struct perf_event
*event
)
984 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
987 * We can have double attach due to group movement in perf_event_open.
989 if (event
->attach_state
& PERF_ATTACH_GROUP
)
992 event
->attach_state
|= PERF_ATTACH_GROUP
;
994 if (group_leader
== event
)
997 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
998 !is_software_event(event
))
999 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1001 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1002 group_leader
->nr_siblings
++;
1004 perf_event__header_size(group_leader
);
1006 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1007 perf_event__header_size(pos
);
1011 * Remove a event from the lists for its context.
1012 * Must be called with ctx->mutex and ctx->lock held.
1015 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1017 struct perf_cpu_context
*cpuctx
;
1019 * We can have double detach due to exit/hot-unplug + close.
1021 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1024 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1026 if (is_cgroup_event(event
)) {
1028 cpuctx
= __get_cpu_context(ctx
);
1030 * if there are no more cgroup events
1031 * then cler cgrp to avoid stale pointer
1032 * in update_cgrp_time_from_cpuctx()
1034 if (!ctx
->nr_cgroups
)
1035 cpuctx
->cgrp
= NULL
;
1038 if (has_branch_stack(event
))
1039 ctx
->nr_branch_stack
--;
1042 if (event
->attr
.inherit_stat
)
1045 list_del_rcu(&event
->event_entry
);
1047 if (event
->group_leader
== event
)
1048 list_del_init(&event
->group_entry
);
1050 update_group_times(event
);
1053 * If event was in error state, then keep it
1054 * that way, otherwise bogus counts will be
1055 * returned on read(). The only way to get out
1056 * of error state is by explicit re-enabling
1059 if (event
->state
> PERF_EVENT_STATE_OFF
)
1060 event
->state
= PERF_EVENT_STATE_OFF
;
1063 static void perf_group_detach(struct perf_event
*event
)
1065 struct perf_event
*sibling
, *tmp
;
1066 struct list_head
*list
= NULL
;
1069 * We can have double detach due to exit/hot-unplug + close.
1071 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1074 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1077 * If this is a sibling, remove it from its group.
1079 if (event
->group_leader
!= event
) {
1080 list_del_init(&event
->group_entry
);
1081 event
->group_leader
->nr_siblings
--;
1085 if (!list_empty(&event
->group_entry
))
1086 list
= &event
->group_entry
;
1089 * If this was a group event with sibling events then
1090 * upgrade the siblings to singleton events by adding them
1091 * to whatever list we are on.
1093 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1095 list_move_tail(&sibling
->group_entry
, list
);
1096 sibling
->group_leader
= sibling
;
1098 /* Inherit group flags from the previous leader */
1099 sibling
->group_flags
= event
->group_flags
;
1103 perf_event__header_size(event
->group_leader
);
1105 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1106 perf_event__header_size(tmp
);
1110 event_filter_match(struct perf_event
*event
)
1112 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1113 && perf_cgroup_match(event
);
1117 event_sched_out(struct perf_event
*event
,
1118 struct perf_cpu_context
*cpuctx
,
1119 struct perf_event_context
*ctx
)
1121 u64 tstamp
= perf_event_time(event
);
1124 * An event which could not be activated because of
1125 * filter mismatch still needs to have its timings
1126 * maintained, otherwise bogus information is return
1127 * via read() for time_enabled, time_running:
1129 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1130 && !event_filter_match(event
)) {
1131 delta
= tstamp
- event
->tstamp_stopped
;
1132 event
->tstamp_running
+= delta
;
1133 event
->tstamp_stopped
= tstamp
;
1136 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1139 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1140 if (event
->pending_disable
) {
1141 event
->pending_disable
= 0;
1142 event
->state
= PERF_EVENT_STATE_OFF
;
1144 event
->tstamp_stopped
= tstamp
;
1145 event
->pmu
->del(event
, 0);
1148 if (!is_software_event(event
))
1149 cpuctx
->active_oncpu
--;
1151 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1153 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1154 cpuctx
->exclusive
= 0;
1158 group_sched_out(struct perf_event
*group_event
,
1159 struct perf_cpu_context
*cpuctx
,
1160 struct perf_event_context
*ctx
)
1162 struct perf_event
*event
;
1163 int state
= group_event
->state
;
1165 event_sched_out(group_event
, cpuctx
, ctx
);
1168 * Schedule out siblings (if any):
1170 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1171 event_sched_out(event
, cpuctx
, ctx
);
1173 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1174 cpuctx
->exclusive
= 0;
1178 * Cross CPU call to remove a performance event
1180 * We disable the event on the hardware level first. After that we
1181 * remove it from the context list.
1183 static int __perf_remove_from_context(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
);
1189 raw_spin_lock(&ctx
->lock
);
1190 event_sched_out(event
, cpuctx
, ctx
);
1191 list_del_event(event
, ctx
);
1192 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1194 cpuctx
->task_ctx
= NULL
;
1196 raw_spin_unlock(&ctx
->lock
);
1203 * Remove the event from a task's (or a CPU's) list of events.
1205 * CPU events are removed with a smp call. For task events we only
1206 * call when the task is on a CPU.
1208 * If event->ctx is a cloned context, callers must make sure that
1209 * every task struct that event->ctx->task could possibly point to
1210 * remains valid. This is OK when called from perf_release since
1211 * that only calls us on the top-level context, which can't be a clone.
1212 * When called from perf_event_exit_task, it's OK because the
1213 * context has been detached from its task.
1215 static void perf_remove_from_context(struct perf_event
*event
)
1217 struct perf_event_context
*ctx
= event
->ctx
;
1218 struct task_struct
*task
= ctx
->task
;
1220 lockdep_assert_held(&ctx
->mutex
);
1224 * Per cpu events are removed via an smp call and
1225 * the removal is always successful.
1227 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1232 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1235 raw_spin_lock_irq(&ctx
->lock
);
1237 * If we failed to find a running task, but find the context active now
1238 * that we've acquired the ctx->lock, retry.
1240 if (ctx
->is_active
) {
1241 raw_spin_unlock_irq(&ctx
->lock
);
1246 * Since the task isn't running, its safe to remove the event, us
1247 * holding the ctx->lock ensures the task won't get scheduled in.
1249 list_del_event(event
, ctx
);
1250 raw_spin_unlock_irq(&ctx
->lock
);
1254 * Cross CPU call to disable a performance event
1256 static int __perf_event_disable(void *info
)
1258 struct perf_event
*event
= info
;
1259 struct perf_event_context
*ctx
= event
->ctx
;
1260 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1263 * If this is a per-task event, need to check whether this
1264 * event's task is the current task on this cpu.
1266 * Can trigger due to concurrent perf_event_context_sched_out()
1267 * flipping contexts around.
1269 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1272 raw_spin_lock(&ctx
->lock
);
1275 * If the event is on, turn it off.
1276 * If it is in error state, leave it in error state.
1278 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1279 update_context_time(ctx
);
1280 update_cgrp_time_from_event(event
);
1281 update_group_times(event
);
1282 if (event
== event
->group_leader
)
1283 group_sched_out(event
, cpuctx
, ctx
);
1285 event_sched_out(event
, cpuctx
, ctx
);
1286 event
->state
= PERF_EVENT_STATE_OFF
;
1289 raw_spin_unlock(&ctx
->lock
);
1297 * If event->ctx is a cloned context, callers must make sure that
1298 * every task struct that event->ctx->task could possibly point to
1299 * remains valid. This condition is satisifed when called through
1300 * perf_event_for_each_child or perf_event_for_each because they
1301 * hold the top-level event's child_mutex, so any descendant that
1302 * goes to exit will block in sync_child_event.
1303 * When called from perf_pending_event it's OK because event->ctx
1304 * is the current context on this CPU and preemption is disabled,
1305 * hence we can't get into perf_event_task_sched_out for this context.
1307 void perf_event_disable(struct perf_event
*event
)
1309 struct perf_event_context
*ctx
= event
->ctx
;
1310 struct task_struct
*task
= ctx
->task
;
1314 * Disable the event on the cpu that it's on
1316 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1321 if (!task_function_call(task
, __perf_event_disable
, event
))
1324 raw_spin_lock_irq(&ctx
->lock
);
1326 * If the event is still active, we need to retry the cross-call.
1328 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1329 raw_spin_unlock_irq(&ctx
->lock
);
1331 * Reload the task pointer, it might have been changed by
1332 * a concurrent perf_event_context_sched_out().
1339 * Since we have the lock this context can't be scheduled
1340 * in, so we can change the state safely.
1342 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1343 update_group_times(event
);
1344 event
->state
= PERF_EVENT_STATE_OFF
;
1346 raw_spin_unlock_irq(&ctx
->lock
);
1348 EXPORT_SYMBOL_GPL(perf_event_disable
);
1350 static void perf_set_shadow_time(struct perf_event
*event
,
1351 struct perf_event_context
*ctx
,
1355 * use the correct time source for the time snapshot
1357 * We could get by without this by leveraging the
1358 * fact that to get to this function, the caller
1359 * has most likely already called update_context_time()
1360 * and update_cgrp_time_xx() and thus both timestamp
1361 * are identical (or very close). Given that tstamp is,
1362 * already adjusted for cgroup, we could say that:
1363 * tstamp - ctx->timestamp
1365 * tstamp - cgrp->timestamp.
1367 * Then, in perf_output_read(), the calculation would
1368 * work with no changes because:
1369 * - event is guaranteed scheduled in
1370 * - no scheduled out in between
1371 * - thus the timestamp would be the same
1373 * But this is a bit hairy.
1375 * So instead, we have an explicit cgroup call to remain
1376 * within the time time source all along. We believe it
1377 * is cleaner and simpler to understand.
1379 if (is_cgroup_event(event
))
1380 perf_cgroup_set_shadow_time(event
, tstamp
);
1382 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1385 #define MAX_INTERRUPTS (~0ULL)
1387 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1390 event_sched_in(struct perf_event
*event
,
1391 struct perf_cpu_context
*cpuctx
,
1392 struct perf_event_context
*ctx
)
1394 u64 tstamp
= perf_event_time(event
);
1396 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1399 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1400 event
->oncpu
= smp_processor_id();
1403 * Unthrottle events, since we scheduled we might have missed several
1404 * ticks already, also for a heavily scheduling task there is little
1405 * guarantee it'll get a tick in a timely manner.
1407 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1408 perf_log_throttle(event
, 1);
1409 event
->hw
.interrupts
= 0;
1413 * The new state must be visible before we turn it on in the hardware:
1417 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1418 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1423 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1425 perf_set_shadow_time(event
, ctx
, tstamp
);
1427 if (!is_software_event(event
))
1428 cpuctx
->active_oncpu
++;
1430 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1433 if (event
->attr
.exclusive
)
1434 cpuctx
->exclusive
= 1;
1440 group_sched_in(struct perf_event
*group_event
,
1441 struct perf_cpu_context
*cpuctx
,
1442 struct perf_event_context
*ctx
)
1444 struct perf_event
*event
, *partial_group
= NULL
;
1445 struct pmu
*pmu
= group_event
->pmu
;
1446 u64 now
= ctx
->time
;
1447 bool simulate
= false;
1449 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1452 pmu
->start_txn(pmu
);
1454 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1455 pmu
->cancel_txn(pmu
);
1460 * Schedule in siblings as one group (if any):
1462 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1463 if (event_sched_in(event
, cpuctx
, ctx
)) {
1464 partial_group
= event
;
1469 if (!pmu
->commit_txn(pmu
))
1474 * Groups can be scheduled in as one unit only, so undo any
1475 * partial group before returning:
1476 * The events up to the failed event are scheduled out normally,
1477 * tstamp_stopped will be updated.
1479 * The failed events and the remaining siblings need to have
1480 * their timings updated as if they had gone thru event_sched_in()
1481 * and event_sched_out(). This is required to get consistent timings
1482 * across the group. This also takes care of the case where the group
1483 * could never be scheduled by ensuring tstamp_stopped is set to mark
1484 * the time the event was actually stopped, such that time delta
1485 * calculation in update_event_times() is correct.
1487 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1488 if (event
== partial_group
)
1492 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1493 event
->tstamp_stopped
= now
;
1495 event_sched_out(event
, cpuctx
, ctx
);
1498 event_sched_out(group_event
, cpuctx
, ctx
);
1500 pmu
->cancel_txn(pmu
);
1506 * Work out whether we can put this event group on the CPU now.
1508 static int group_can_go_on(struct perf_event
*event
,
1509 struct perf_cpu_context
*cpuctx
,
1513 * Groups consisting entirely of software events can always go on.
1515 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1518 * If an exclusive group is already on, no other hardware
1521 if (cpuctx
->exclusive
)
1524 * If this group is exclusive and there are already
1525 * events on the CPU, it can't go on.
1527 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1530 * Otherwise, try to add it if all previous groups were able
1536 static void add_event_to_ctx(struct perf_event
*event
,
1537 struct perf_event_context
*ctx
)
1539 u64 tstamp
= perf_event_time(event
);
1541 list_add_event(event
, ctx
);
1542 perf_group_attach(event
);
1543 event
->tstamp_enabled
= tstamp
;
1544 event
->tstamp_running
= tstamp
;
1545 event
->tstamp_stopped
= tstamp
;
1548 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
1550 ctx_sched_in(struct perf_event_context
*ctx
,
1551 struct perf_cpu_context
*cpuctx
,
1552 enum event_type_t event_type
,
1553 struct task_struct
*task
);
1555 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
1556 struct perf_event_context
*ctx
,
1557 struct task_struct
*task
)
1559 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
1561 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
1562 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
1564 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
1568 * Cross CPU call to install and enable a performance event
1570 * Must be called with ctx->mutex held
1572 static int __perf_install_in_context(void *info
)
1574 struct perf_event
*event
= info
;
1575 struct perf_event_context
*ctx
= event
->ctx
;
1576 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1577 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
1578 struct task_struct
*task
= current
;
1580 perf_ctx_lock(cpuctx
, task_ctx
);
1581 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1584 * If there was an active task_ctx schedule it out.
1587 task_ctx_sched_out(task_ctx
);
1590 * If the context we're installing events in is not the
1591 * active task_ctx, flip them.
1593 if (ctx
->task
&& task_ctx
!= ctx
) {
1595 raw_spin_unlock(&task_ctx
->lock
);
1596 raw_spin_lock(&ctx
->lock
);
1601 cpuctx
->task_ctx
= task_ctx
;
1602 task
= task_ctx
->task
;
1605 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
1607 update_context_time(ctx
);
1609 * update cgrp time only if current cgrp
1610 * matches event->cgrp. Must be done before
1611 * calling add_event_to_ctx()
1613 update_cgrp_time_from_event(event
);
1615 add_event_to_ctx(event
, ctx
);
1618 * Schedule everything back in
1620 perf_event_sched_in(cpuctx
, task_ctx
, task
);
1622 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1623 perf_ctx_unlock(cpuctx
, task_ctx
);
1629 * Attach a performance event to a context
1631 * First we add the event to the list with the hardware enable bit
1632 * in event->hw_config cleared.
1634 * If the event is attached to a task which is on a CPU we use a smp
1635 * call to enable it in the task context. The task might have been
1636 * scheduled away, but we check this in the smp call again.
1639 perf_install_in_context(struct perf_event_context
*ctx
,
1640 struct perf_event
*event
,
1643 struct task_struct
*task
= ctx
->task
;
1645 lockdep_assert_held(&ctx
->mutex
);
1648 if (event
->cpu
!= -1)
1653 * Per cpu events are installed via an smp call and
1654 * the install is always successful.
1656 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1661 if (!task_function_call(task
, __perf_install_in_context
, event
))
1664 raw_spin_lock_irq(&ctx
->lock
);
1666 * If we failed to find a running task, but find the context active now
1667 * that we've acquired the ctx->lock, retry.
1669 if (ctx
->is_active
) {
1670 raw_spin_unlock_irq(&ctx
->lock
);
1675 * Since the task isn't running, its safe to add the event, us holding
1676 * the ctx->lock ensures the task won't get scheduled in.
1678 add_event_to_ctx(event
, ctx
);
1679 raw_spin_unlock_irq(&ctx
->lock
);
1683 * Put a event into inactive state and update time fields.
1684 * Enabling the leader of a group effectively enables all
1685 * the group members that aren't explicitly disabled, so we
1686 * have to update their ->tstamp_enabled also.
1687 * Note: this works for group members as well as group leaders
1688 * since the non-leader members' sibling_lists will be empty.
1690 static void __perf_event_mark_enabled(struct perf_event
*event
)
1692 struct perf_event
*sub
;
1693 u64 tstamp
= perf_event_time(event
);
1695 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1696 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1697 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1698 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1699 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1704 * Cross CPU call to enable a performance event
1706 static int __perf_event_enable(void *info
)
1708 struct perf_event
*event
= info
;
1709 struct perf_event_context
*ctx
= event
->ctx
;
1710 struct perf_event
*leader
= event
->group_leader
;
1711 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1714 if (WARN_ON_ONCE(!ctx
->is_active
))
1717 raw_spin_lock(&ctx
->lock
);
1718 update_context_time(ctx
);
1720 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1724 * set current task's cgroup time reference point
1726 perf_cgroup_set_timestamp(current
, ctx
);
1728 __perf_event_mark_enabled(event
);
1730 if (!event_filter_match(event
)) {
1731 if (is_cgroup_event(event
))
1732 perf_cgroup_defer_enabled(event
);
1737 * If the event is in a group and isn't the group leader,
1738 * then don't put it on unless the group is on.
1740 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1743 if (!group_can_go_on(event
, cpuctx
, 1)) {
1746 if (event
== leader
)
1747 err
= group_sched_in(event
, cpuctx
, ctx
);
1749 err
= event_sched_in(event
, cpuctx
, ctx
);
1754 * If this event can't go on and it's part of a
1755 * group, then the whole group has to come off.
1757 if (leader
!= event
)
1758 group_sched_out(leader
, cpuctx
, ctx
);
1759 if (leader
->attr
.pinned
) {
1760 update_group_times(leader
);
1761 leader
->state
= PERF_EVENT_STATE_ERROR
;
1766 raw_spin_unlock(&ctx
->lock
);
1774 * If event->ctx is a cloned context, callers must make sure that
1775 * every task struct that event->ctx->task could possibly point to
1776 * remains valid. This condition is satisfied when called through
1777 * perf_event_for_each_child or perf_event_for_each as described
1778 * for perf_event_disable.
1780 void perf_event_enable(struct perf_event
*event
)
1782 struct perf_event_context
*ctx
= event
->ctx
;
1783 struct task_struct
*task
= ctx
->task
;
1787 * Enable the event on the cpu that it's on
1789 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
1793 raw_spin_lock_irq(&ctx
->lock
);
1794 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1798 * If the event is in error state, clear that first.
1799 * That way, if we see the event in error state below, we
1800 * know that it has gone back into error state, as distinct
1801 * from the task having been scheduled away before the
1802 * cross-call arrived.
1804 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1805 event
->state
= PERF_EVENT_STATE_OFF
;
1808 if (!ctx
->is_active
) {
1809 __perf_event_mark_enabled(event
);
1813 raw_spin_unlock_irq(&ctx
->lock
);
1815 if (!task_function_call(task
, __perf_event_enable
, event
))
1818 raw_spin_lock_irq(&ctx
->lock
);
1821 * If the context is active and the event is still off,
1822 * we need to retry the cross-call.
1824 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
1826 * task could have been flipped by a concurrent
1827 * perf_event_context_sched_out()
1834 raw_spin_unlock_irq(&ctx
->lock
);
1836 EXPORT_SYMBOL_GPL(perf_event_enable
);
1838 int perf_event_refresh(struct perf_event
*event
, int refresh
)
1841 * not supported on inherited events
1843 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1846 atomic_add(refresh
, &event
->event_limit
);
1847 perf_event_enable(event
);
1851 EXPORT_SYMBOL_GPL(perf_event_refresh
);
1853 static void ctx_sched_out(struct perf_event_context
*ctx
,
1854 struct perf_cpu_context
*cpuctx
,
1855 enum event_type_t event_type
)
1857 struct perf_event
*event
;
1858 int is_active
= ctx
->is_active
;
1860 ctx
->is_active
&= ~event_type
;
1861 if (likely(!ctx
->nr_events
))
1864 update_context_time(ctx
);
1865 update_cgrp_time_from_cpuctx(cpuctx
);
1866 if (!ctx
->nr_active
)
1869 perf_pmu_disable(ctx
->pmu
);
1870 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
1871 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1872 group_sched_out(event
, cpuctx
, ctx
);
1875 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
1876 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1877 group_sched_out(event
, cpuctx
, ctx
);
1879 perf_pmu_enable(ctx
->pmu
);
1883 * Test whether two contexts are equivalent, i.e. whether they
1884 * have both been cloned from the same version of the same context
1885 * and they both have the same number of enabled events.
1886 * If the number of enabled events is the same, then the set
1887 * of enabled events should be the same, because these are both
1888 * inherited contexts, therefore we can't access individual events
1889 * in them directly with an fd; we can only enable/disable all
1890 * events via prctl, or enable/disable all events in a family
1891 * via ioctl, which will have the same effect on both contexts.
1893 static int context_equiv(struct perf_event_context
*ctx1
,
1894 struct perf_event_context
*ctx2
)
1896 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1897 && ctx1
->parent_gen
== ctx2
->parent_gen
1898 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1901 static void __perf_event_sync_stat(struct perf_event
*event
,
1902 struct perf_event
*next_event
)
1906 if (!event
->attr
.inherit_stat
)
1910 * Update the event value, we cannot use perf_event_read()
1911 * because we're in the middle of a context switch and have IRQs
1912 * disabled, which upsets smp_call_function_single(), however
1913 * we know the event must be on the current CPU, therefore we
1914 * don't need to use it.
1916 switch (event
->state
) {
1917 case PERF_EVENT_STATE_ACTIVE
:
1918 event
->pmu
->read(event
);
1921 case PERF_EVENT_STATE_INACTIVE
:
1922 update_event_times(event
);
1930 * In order to keep per-task stats reliable we need to flip the event
1931 * values when we flip the contexts.
1933 value
= local64_read(&next_event
->count
);
1934 value
= local64_xchg(&event
->count
, value
);
1935 local64_set(&next_event
->count
, value
);
1937 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1938 swap(event
->total_time_running
, next_event
->total_time_running
);
1941 * Since we swizzled the values, update the user visible data too.
1943 perf_event_update_userpage(event
);
1944 perf_event_update_userpage(next_event
);
1947 #define list_next_entry(pos, member) \
1948 list_entry(pos->member.next, typeof(*pos), member)
1950 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1951 struct perf_event_context
*next_ctx
)
1953 struct perf_event
*event
, *next_event
;
1958 update_context_time(ctx
);
1960 event
= list_first_entry(&ctx
->event_list
,
1961 struct perf_event
, event_entry
);
1963 next_event
= list_first_entry(&next_ctx
->event_list
,
1964 struct perf_event
, event_entry
);
1966 while (&event
->event_entry
!= &ctx
->event_list
&&
1967 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1969 __perf_event_sync_stat(event
, next_event
);
1971 event
= list_next_entry(event
, event_entry
);
1972 next_event
= list_next_entry(next_event
, event_entry
);
1976 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
1977 struct task_struct
*next
)
1979 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
1980 struct perf_event_context
*next_ctx
;
1981 struct perf_event_context
*parent
;
1982 struct perf_cpu_context
*cpuctx
;
1988 cpuctx
= __get_cpu_context(ctx
);
1989 if (!cpuctx
->task_ctx
)
1993 parent
= rcu_dereference(ctx
->parent_ctx
);
1994 next_ctx
= next
->perf_event_ctxp
[ctxn
];
1995 if (parent
&& next_ctx
&&
1996 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1998 * Looks like the two contexts are clones, so we might be
1999 * able to optimize the context switch. We lock both
2000 * contexts and check that they are clones under the
2001 * lock (including re-checking that neither has been
2002 * uncloned in the meantime). It doesn't matter which
2003 * order we take the locks because no other cpu could
2004 * be trying to lock both of these tasks.
2006 raw_spin_lock(&ctx
->lock
);
2007 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2008 if (context_equiv(ctx
, next_ctx
)) {
2010 * XXX do we need a memory barrier of sorts
2011 * wrt to rcu_dereference() of perf_event_ctxp
2013 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2014 next
->perf_event_ctxp
[ctxn
] = ctx
;
2016 next_ctx
->task
= task
;
2019 perf_event_sync_stat(ctx
, next_ctx
);
2021 raw_spin_unlock(&next_ctx
->lock
);
2022 raw_spin_unlock(&ctx
->lock
);
2027 raw_spin_lock(&ctx
->lock
);
2028 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2029 cpuctx
->task_ctx
= NULL
;
2030 raw_spin_unlock(&ctx
->lock
);
2034 #define for_each_task_context_nr(ctxn) \
2035 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2038 * Called from scheduler to remove the events of the current task,
2039 * with interrupts disabled.
2041 * We stop each event and update the event value in event->count.
2043 * This does not protect us against NMI, but disable()
2044 * sets the disabled bit in the control field of event _before_
2045 * accessing the event control register. If a NMI hits, then it will
2046 * not restart the event.
2048 void __perf_event_task_sched_out(struct task_struct
*task
,
2049 struct task_struct
*next
)
2053 for_each_task_context_nr(ctxn
)
2054 perf_event_context_sched_out(task
, ctxn
, next
);
2057 * if cgroup events exist on this CPU, then we need
2058 * to check if we have to switch out PMU state.
2059 * cgroup event are system-wide mode only
2061 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2062 perf_cgroup_sched_out(task
, next
);
2065 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2067 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2069 if (!cpuctx
->task_ctx
)
2072 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2075 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2076 cpuctx
->task_ctx
= NULL
;
2080 * Called with IRQs disabled
2082 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2083 enum event_type_t event_type
)
2085 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2089 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2090 struct perf_cpu_context
*cpuctx
)
2092 struct perf_event
*event
;
2094 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2095 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2097 if (!event_filter_match(event
))
2100 /* may need to reset tstamp_enabled */
2101 if (is_cgroup_event(event
))
2102 perf_cgroup_mark_enabled(event
, ctx
);
2104 if (group_can_go_on(event
, cpuctx
, 1))
2105 group_sched_in(event
, cpuctx
, ctx
);
2108 * If this pinned group hasn't been scheduled,
2109 * put it in error state.
2111 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2112 update_group_times(event
);
2113 event
->state
= PERF_EVENT_STATE_ERROR
;
2119 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2120 struct perf_cpu_context
*cpuctx
)
2122 struct perf_event
*event
;
2125 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2126 /* Ignore events in OFF or ERROR state */
2127 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2130 * Listen to the 'cpu' scheduling filter constraint
2133 if (!event_filter_match(event
))
2136 /* may need to reset tstamp_enabled */
2137 if (is_cgroup_event(event
))
2138 perf_cgroup_mark_enabled(event
, ctx
);
2140 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2141 if (group_sched_in(event
, cpuctx
, ctx
))
2148 ctx_sched_in(struct perf_event_context
*ctx
,
2149 struct perf_cpu_context
*cpuctx
,
2150 enum event_type_t event_type
,
2151 struct task_struct
*task
)
2154 int is_active
= ctx
->is_active
;
2156 ctx
->is_active
|= event_type
;
2157 if (likely(!ctx
->nr_events
))
2161 ctx
->timestamp
= now
;
2162 perf_cgroup_set_timestamp(task
, ctx
);
2164 * First go through the list and put on any pinned groups
2165 * in order to give them the best chance of going on.
2167 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2168 ctx_pinned_sched_in(ctx
, cpuctx
);
2170 /* Then walk through the lower prio flexible groups */
2171 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2172 ctx_flexible_sched_in(ctx
, cpuctx
);
2175 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2176 enum event_type_t event_type
,
2177 struct task_struct
*task
)
2179 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2181 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2184 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2185 struct task_struct
*task
)
2187 struct perf_cpu_context
*cpuctx
;
2189 cpuctx
= __get_cpu_context(ctx
);
2190 if (cpuctx
->task_ctx
== ctx
)
2193 perf_ctx_lock(cpuctx
, ctx
);
2194 perf_pmu_disable(ctx
->pmu
);
2196 * We want to keep the following priority order:
2197 * cpu pinned (that don't need to move), task pinned,
2198 * cpu flexible, task flexible.
2200 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2203 cpuctx
->task_ctx
= ctx
;
2205 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2207 perf_pmu_enable(ctx
->pmu
);
2208 perf_ctx_unlock(cpuctx
, ctx
);
2211 * Since these rotations are per-cpu, we need to ensure the
2212 * cpu-context we got scheduled on is actually rotating.
2214 perf_pmu_rotate_start(ctx
->pmu
);
2218 * When sampling the branck stack in system-wide, it may be necessary
2219 * to flush the stack on context switch. This happens when the branch
2220 * stack does not tag its entries with the pid of the current task.
2221 * Otherwise it becomes impossible to associate a branch entry with a
2222 * task. This ambiguity is more likely to appear when the branch stack
2223 * supports priv level filtering and the user sets it to monitor only
2224 * at the user level (which could be a useful measurement in system-wide
2225 * mode). In that case, the risk is high of having a branch stack with
2226 * branch from multiple tasks. Flushing may mean dropping the existing
2227 * entries or stashing them somewhere in the PMU specific code layer.
2229 * This function provides the context switch callback to the lower code
2230 * layer. It is invoked ONLY when there is at least one system-wide context
2231 * with at least one active event using taken branch sampling.
2233 static void perf_branch_stack_sched_in(struct task_struct
*prev
,
2234 struct task_struct
*task
)
2236 struct perf_cpu_context
*cpuctx
;
2238 unsigned long flags
;
2240 /* no need to flush branch stack if not changing task */
2244 local_irq_save(flags
);
2248 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2249 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2252 * check if the context has at least one
2253 * event using PERF_SAMPLE_BRANCH_STACK
2255 if (cpuctx
->ctx
.nr_branch_stack
> 0
2256 && pmu
->flush_branch_stack
) {
2258 pmu
= cpuctx
->ctx
.pmu
;
2260 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2262 perf_pmu_disable(pmu
);
2264 pmu
->flush_branch_stack();
2266 perf_pmu_enable(pmu
);
2268 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2274 local_irq_restore(flags
);
2278 * Called from scheduler to add the events of the current task
2279 * with interrupts disabled.
2281 * We restore the event value and then enable it.
2283 * This does not protect us against NMI, but enable()
2284 * sets the enabled bit in the control field of event _before_
2285 * accessing the event control register. If a NMI hits, then it will
2286 * keep the event running.
2288 void __perf_event_task_sched_in(struct task_struct
*prev
,
2289 struct task_struct
*task
)
2291 struct perf_event_context
*ctx
;
2294 for_each_task_context_nr(ctxn
) {
2295 ctx
= task
->perf_event_ctxp
[ctxn
];
2299 perf_event_context_sched_in(ctx
, task
);
2302 * if cgroup events exist on this CPU, then we need
2303 * to check if we have to switch in PMU state.
2304 * cgroup event are system-wide mode only
2306 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2307 perf_cgroup_sched_in(prev
, task
);
2309 /* check for system-wide branch_stack events */
2310 if (atomic_read(&__get_cpu_var(perf_branch_stack_events
)))
2311 perf_branch_stack_sched_in(prev
, task
);
2314 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2316 u64 frequency
= event
->attr
.sample_freq
;
2317 u64 sec
= NSEC_PER_SEC
;
2318 u64 divisor
, dividend
;
2320 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2322 count_fls
= fls64(count
);
2323 nsec_fls
= fls64(nsec
);
2324 frequency_fls
= fls64(frequency
);
2328 * We got @count in @nsec, with a target of sample_freq HZ
2329 * the target period becomes:
2332 * period = -------------------
2333 * @nsec * sample_freq
2338 * Reduce accuracy by one bit such that @a and @b converge
2339 * to a similar magnitude.
2341 #define REDUCE_FLS(a, b) \
2343 if (a##_fls > b##_fls) { \
2353 * Reduce accuracy until either term fits in a u64, then proceed with
2354 * the other, so that finally we can do a u64/u64 division.
2356 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2357 REDUCE_FLS(nsec
, frequency
);
2358 REDUCE_FLS(sec
, count
);
2361 if (count_fls
+ sec_fls
> 64) {
2362 divisor
= nsec
* frequency
;
2364 while (count_fls
+ sec_fls
> 64) {
2365 REDUCE_FLS(count
, sec
);
2369 dividend
= count
* sec
;
2371 dividend
= count
* sec
;
2373 while (nsec_fls
+ frequency_fls
> 64) {
2374 REDUCE_FLS(nsec
, frequency
);
2378 divisor
= nsec
* frequency
;
2384 return div64_u64(dividend
, divisor
);
2387 static DEFINE_PER_CPU(int, perf_throttled_count
);
2388 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2390 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2392 struct hw_perf_event
*hwc
= &event
->hw
;
2393 s64 period
, sample_period
;
2396 period
= perf_calculate_period(event
, nsec
, count
);
2398 delta
= (s64
)(period
- hwc
->sample_period
);
2399 delta
= (delta
+ 7) / 8; /* low pass filter */
2401 sample_period
= hwc
->sample_period
+ delta
;
2406 hwc
->sample_period
= sample_period
;
2408 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2410 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2412 local64_set(&hwc
->period_left
, 0);
2415 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2420 * combine freq adjustment with unthrottling to avoid two passes over the
2421 * events. At the same time, make sure, having freq events does not change
2422 * the rate of unthrottling as that would introduce bias.
2424 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2427 struct perf_event
*event
;
2428 struct hw_perf_event
*hwc
;
2429 u64 now
, period
= TICK_NSEC
;
2433 * only need to iterate over all events iff:
2434 * - context have events in frequency mode (needs freq adjust)
2435 * - there are events to unthrottle on this cpu
2437 if (!(ctx
->nr_freq
|| needs_unthr
))
2440 raw_spin_lock(&ctx
->lock
);
2441 perf_pmu_disable(ctx
->pmu
);
2443 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2444 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2447 if (!event_filter_match(event
))
2452 if (needs_unthr
&& hwc
->interrupts
== MAX_INTERRUPTS
) {
2453 hwc
->interrupts
= 0;
2454 perf_log_throttle(event
, 1);
2455 event
->pmu
->start(event
, 0);
2458 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2462 * stop the event and update event->count
2464 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2466 now
= local64_read(&event
->count
);
2467 delta
= now
- hwc
->freq_count_stamp
;
2468 hwc
->freq_count_stamp
= now
;
2472 * reload only if value has changed
2473 * we have stopped the event so tell that
2474 * to perf_adjust_period() to avoid stopping it
2478 perf_adjust_period(event
, period
, delta
, false);
2480 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
2483 perf_pmu_enable(ctx
->pmu
);
2484 raw_spin_unlock(&ctx
->lock
);
2488 * Round-robin a context's events:
2490 static void rotate_ctx(struct perf_event_context
*ctx
)
2493 * Rotate the first entry last of non-pinned groups. Rotation might be
2494 * disabled by the inheritance code.
2496 if (!ctx
->rotate_disable
)
2497 list_rotate_left(&ctx
->flexible_groups
);
2501 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2502 * because they're strictly cpu affine and rotate_start is called with IRQs
2503 * disabled, while rotate_context is called from IRQ context.
2505 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2507 struct perf_event_context
*ctx
= NULL
;
2508 int rotate
= 0, remove
= 1;
2510 if (cpuctx
->ctx
.nr_events
) {
2512 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2516 ctx
= cpuctx
->task_ctx
;
2517 if (ctx
&& ctx
->nr_events
) {
2519 if (ctx
->nr_events
!= ctx
->nr_active
)
2526 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2527 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2529 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2531 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
2533 rotate_ctx(&cpuctx
->ctx
);
2537 perf_event_sched_in(cpuctx
, ctx
, current
);
2539 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2540 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2543 list_del_init(&cpuctx
->rotation_list
);
2546 void perf_event_task_tick(void)
2548 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2549 struct perf_cpu_context
*cpuctx
, *tmp
;
2550 struct perf_event_context
*ctx
;
2553 WARN_ON(!irqs_disabled());
2555 __this_cpu_inc(perf_throttled_seq
);
2556 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
2558 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2560 perf_adjust_freq_unthr_context(ctx
, throttled
);
2562 ctx
= cpuctx
->task_ctx
;
2564 perf_adjust_freq_unthr_context(ctx
, throttled
);
2566 if (cpuctx
->jiffies_interval
== 1 ||
2567 !(jiffies
% cpuctx
->jiffies_interval
))
2568 perf_rotate_context(cpuctx
);
2572 static int event_enable_on_exec(struct perf_event
*event
,
2573 struct perf_event_context
*ctx
)
2575 if (!event
->attr
.enable_on_exec
)
2578 event
->attr
.enable_on_exec
= 0;
2579 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2582 __perf_event_mark_enabled(event
);
2588 * Enable all of a task's events that have been marked enable-on-exec.
2589 * This expects task == current.
2591 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2593 struct perf_event
*event
;
2594 unsigned long flags
;
2598 local_irq_save(flags
);
2599 if (!ctx
|| !ctx
->nr_events
)
2603 * We must ctxsw out cgroup events to avoid conflict
2604 * when invoking perf_task_event_sched_in() later on
2605 * in this function. Otherwise we end up trying to
2606 * ctxswin cgroup events which are already scheduled
2609 perf_cgroup_sched_out(current
, NULL
);
2611 raw_spin_lock(&ctx
->lock
);
2612 task_ctx_sched_out(ctx
);
2614 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
2615 ret
= event_enable_on_exec(event
, ctx
);
2621 * Unclone this context if we enabled any event.
2626 raw_spin_unlock(&ctx
->lock
);
2629 * Also calls ctxswin for cgroup events, if any:
2631 perf_event_context_sched_in(ctx
, ctx
->task
);
2633 local_irq_restore(flags
);
2637 * Cross CPU call to read the hardware event
2639 static void __perf_event_read(void *info
)
2641 struct perf_event
*event
= info
;
2642 struct perf_event_context
*ctx
= event
->ctx
;
2643 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2646 * If this is a task context, we need to check whether it is
2647 * the current task context of this cpu. If not it has been
2648 * scheduled out before the smp call arrived. In that case
2649 * event->count would have been updated to a recent sample
2650 * when the event was scheduled out.
2652 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2655 raw_spin_lock(&ctx
->lock
);
2656 if (ctx
->is_active
) {
2657 update_context_time(ctx
);
2658 update_cgrp_time_from_event(event
);
2660 update_event_times(event
);
2661 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2662 event
->pmu
->read(event
);
2663 raw_spin_unlock(&ctx
->lock
);
2666 static inline u64
perf_event_count(struct perf_event
*event
)
2668 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2671 static u64
perf_event_read(struct perf_event
*event
)
2674 * If event is enabled and currently active on a CPU, update the
2675 * value in the event structure:
2677 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2678 smp_call_function_single(event
->oncpu
,
2679 __perf_event_read
, event
, 1);
2680 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2681 struct perf_event_context
*ctx
= event
->ctx
;
2682 unsigned long flags
;
2684 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2686 * may read while context is not active
2687 * (e.g., thread is blocked), in that case
2688 * we cannot update context time
2690 if (ctx
->is_active
) {
2691 update_context_time(ctx
);
2692 update_cgrp_time_from_event(event
);
2694 update_event_times(event
);
2695 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2698 return perf_event_count(event
);
2702 * Initialize the perf_event context in a task_struct:
2704 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2706 raw_spin_lock_init(&ctx
->lock
);
2707 mutex_init(&ctx
->mutex
);
2708 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2709 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2710 INIT_LIST_HEAD(&ctx
->event_list
);
2711 atomic_set(&ctx
->refcount
, 1);
2714 static struct perf_event_context
*
2715 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2717 struct perf_event_context
*ctx
;
2719 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2723 __perf_event_init_context(ctx
);
2726 get_task_struct(task
);
2733 static struct task_struct
*
2734 find_lively_task_by_vpid(pid_t vpid
)
2736 struct task_struct
*task
;
2743 task
= find_task_by_vpid(vpid
);
2745 get_task_struct(task
);
2749 return ERR_PTR(-ESRCH
);
2751 /* Reuse ptrace permission checks for now. */
2753 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2758 put_task_struct(task
);
2759 return ERR_PTR(err
);
2764 * Returns a matching context with refcount and pincount.
2766 static struct perf_event_context
*
2767 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2769 struct perf_event_context
*ctx
;
2770 struct perf_cpu_context
*cpuctx
;
2771 unsigned long flags
;
2775 /* Must be root to operate on a CPU event: */
2776 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2777 return ERR_PTR(-EACCES
);
2780 * We could be clever and allow to attach a event to an
2781 * offline CPU and activate it when the CPU comes up, but
2784 if (!cpu_online(cpu
))
2785 return ERR_PTR(-ENODEV
);
2787 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2796 ctxn
= pmu
->task_ctx_nr
;
2801 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2805 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2807 ctx
= alloc_perf_context(pmu
, task
);
2813 mutex_lock(&task
->perf_event_mutex
);
2815 * If it has already passed perf_event_exit_task().
2816 * we must see PF_EXITING, it takes this mutex too.
2818 if (task
->flags
& PF_EXITING
)
2820 else if (task
->perf_event_ctxp
[ctxn
])
2825 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2827 mutex_unlock(&task
->perf_event_mutex
);
2829 if (unlikely(err
)) {
2841 return ERR_PTR(err
);
2844 static void perf_event_free_filter(struct perf_event
*event
);
2846 static void free_event_rcu(struct rcu_head
*head
)
2848 struct perf_event
*event
;
2850 event
= container_of(head
, struct perf_event
, rcu_head
);
2852 put_pid_ns(event
->ns
);
2853 perf_event_free_filter(event
);
2857 static void ring_buffer_put(struct ring_buffer
*rb
);
2859 static void free_event(struct perf_event
*event
)
2861 irq_work_sync(&event
->pending
);
2863 if (!event
->parent
) {
2864 if (event
->attach_state
& PERF_ATTACH_TASK
)
2865 static_key_slow_dec_deferred(&perf_sched_events
);
2866 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2867 atomic_dec(&nr_mmap_events
);
2868 if (event
->attr
.comm
)
2869 atomic_dec(&nr_comm_events
);
2870 if (event
->attr
.task
)
2871 atomic_dec(&nr_task_events
);
2872 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2873 put_callchain_buffers();
2874 if (is_cgroup_event(event
)) {
2875 atomic_dec(&per_cpu(perf_cgroup_events
, event
->cpu
));
2876 static_key_slow_dec_deferred(&perf_sched_events
);
2879 if (has_branch_stack(event
)) {
2880 static_key_slow_dec_deferred(&perf_sched_events
);
2881 /* is system-wide event */
2882 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
2883 atomic_dec(&per_cpu(perf_branch_stack_events
,
2889 ring_buffer_put(event
->rb
);
2893 if (is_cgroup_event(event
))
2894 perf_detach_cgroup(event
);
2897 event
->destroy(event
);
2900 put_ctx(event
->ctx
);
2902 call_rcu(&event
->rcu_head
, free_event_rcu
);
2905 int perf_event_release_kernel(struct perf_event
*event
)
2907 struct perf_event_context
*ctx
= event
->ctx
;
2909 WARN_ON_ONCE(ctx
->parent_ctx
);
2911 * There are two ways this annotation is useful:
2913 * 1) there is a lock recursion from perf_event_exit_task
2914 * see the comment there.
2916 * 2) there is a lock-inversion with mmap_sem through
2917 * perf_event_read_group(), which takes faults while
2918 * holding ctx->mutex, however this is called after
2919 * the last filedesc died, so there is no possibility
2920 * to trigger the AB-BA case.
2922 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2923 raw_spin_lock_irq(&ctx
->lock
);
2924 perf_group_detach(event
);
2925 raw_spin_unlock_irq(&ctx
->lock
);
2926 perf_remove_from_context(event
);
2927 mutex_unlock(&ctx
->mutex
);
2933 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2936 * Called when the last reference to the file is gone.
2938 static int perf_release(struct inode
*inode
, struct file
*file
)
2940 struct perf_event
*event
= file
->private_data
;
2941 struct task_struct
*owner
;
2943 file
->private_data
= NULL
;
2946 owner
= ACCESS_ONCE(event
->owner
);
2948 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2949 * !owner it means the list deletion is complete and we can indeed
2950 * free this event, otherwise we need to serialize on
2951 * owner->perf_event_mutex.
2953 smp_read_barrier_depends();
2956 * Since delayed_put_task_struct() also drops the last
2957 * task reference we can safely take a new reference
2958 * while holding the rcu_read_lock().
2960 get_task_struct(owner
);
2965 mutex_lock(&owner
->perf_event_mutex
);
2967 * We have to re-check the event->owner field, if it is cleared
2968 * we raced with perf_event_exit_task(), acquiring the mutex
2969 * ensured they're done, and we can proceed with freeing the
2973 list_del_init(&event
->owner_entry
);
2974 mutex_unlock(&owner
->perf_event_mutex
);
2975 put_task_struct(owner
);
2978 return perf_event_release_kernel(event
);
2981 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
2983 struct perf_event
*child
;
2989 mutex_lock(&event
->child_mutex
);
2990 total
+= perf_event_read(event
);
2991 *enabled
+= event
->total_time_enabled
+
2992 atomic64_read(&event
->child_total_time_enabled
);
2993 *running
+= event
->total_time_running
+
2994 atomic64_read(&event
->child_total_time_running
);
2996 list_for_each_entry(child
, &event
->child_list
, child_list
) {
2997 total
+= perf_event_read(child
);
2998 *enabled
+= child
->total_time_enabled
;
2999 *running
+= child
->total_time_running
;
3001 mutex_unlock(&event
->child_mutex
);
3005 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3007 static int perf_event_read_group(struct perf_event
*event
,
3008 u64 read_format
, char __user
*buf
)
3010 struct perf_event
*leader
= event
->group_leader
, *sub
;
3011 int n
= 0, size
= 0, ret
= -EFAULT
;
3012 struct perf_event_context
*ctx
= leader
->ctx
;
3014 u64 count
, enabled
, running
;
3016 mutex_lock(&ctx
->mutex
);
3017 count
= perf_event_read_value(leader
, &enabled
, &running
);
3019 values
[n
++] = 1 + leader
->nr_siblings
;
3020 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3021 values
[n
++] = enabled
;
3022 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3023 values
[n
++] = running
;
3024 values
[n
++] = count
;
3025 if (read_format
& PERF_FORMAT_ID
)
3026 values
[n
++] = primary_event_id(leader
);
3028 size
= n
* sizeof(u64
);
3030 if (copy_to_user(buf
, values
, size
))
3035 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3038 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3039 if (read_format
& PERF_FORMAT_ID
)
3040 values
[n
++] = primary_event_id(sub
);
3042 size
= n
* sizeof(u64
);
3044 if (copy_to_user(buf
+ ret
, values
, size
)) {
3052 mutex_unlock(&ctx
->mutex
);
3057 static int perf_event_read_one(struct perf_event
*event
,
3058 u64 read_format
, char __user
*buf
)
3060 u64 enabled
, running
;
3064 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3065 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3066 values
[n
++] = enabled
;
3067 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3068 values
[n
++] = running
;
3069 if (read_format
& PERF_FORMAT_ID
)
3070 values
[n
++] = primary_event_id(event
);
3072 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3075 return n
* sizeof(u64
);
3079 * Read the performance event - simple non blocking version for now
3082 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3084 u64 read_format
= event
->attr
.read_format
;
3088 * Return end-of-file for a read on a event that is in
3089 * error state (i.e. because it was pinned but it couldn't be
3090 * scheduled on to the CPU at some point).
3092 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3095 if (count
< event
->read_size
)
3098 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3099 if (read_format
& PERF_FORMAT_GROUP
)
3100 ret
= perf_event_read_group(event
, read_format
, buf
);
3102 ret
= perf_event_read_one(event
, read_format
, buf
);
3108 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3110 struct perf_event
*event
= file
->private_data
;
3112 return perf_read_hw(event
, buf
, count
);
3115 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3117 struct perf_event
*event
= file
->private_data
;
3118 struct ring_buffer
*rb
;
3119 unsigned int events
= POLL_HUP
;
3122 * Race between perf_event_set_output() and perf_poll(): perf_poll()
3123 * grabs the rb reference but perf_event_set_output() overrides it.
3124 * Here is the timeline for two threads T1, T2:
3125 * t0: T1, rb = rcu_dereference(event->rb)
3126 * t1: T2, old_rb = event->rb
3127 * t2: T2, event->rb = new rb
3128 * t3: T2, ring_buffer_detach(old_rb)
3129 * t4: T1, ring_buffer_attach(rb1)
3130 * t5: T1, poll_wait(event->waitq)
3132 * To avoid this problem, we grab mmap_mutex in perf_poll()
3133 * thereby ensuring that the assignment of the new ring buffer
3134 * and the detachment of the old buffer appear atomic to perf_poll()
3136 mutex_lock(&event
->mmap_mutex
);
3139 rb
= rcu_dereference(event
->rb
);
3141 ring_buffer_attach(event
, rb
);
3142 events
= atomic_xchg(&rb
->poll
, 0);
3146 mutex_unlock(&event
->mmap_mutex
);
3148 poll_wait(file
, &event
->waitq
, wait
);
3153 static void perf_event_reset(struct perf_event
*event
)
3155 (void)perf_event_read(event
);
3156 local64_set(&event
->count
, 0);
3157 perf_event_update_userpage(event
);
3161 * Holding the top-level event's child_mutex means that any
3162 * descendant process that has inherited this event will block
3163 * in sync_child_event if it goes to exit, thus satisfying the
3164 * task existence requirements of perf_event_enable/disable.
3166 static void perf_event_for_each_child(struct perf_event
*event
,
3167 void (*func
)(struct perf_event
*))
3169 struct perf_event
*child
;
3171 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3172 mutex_lock(&event
->child_mutex
);
3174 list_for_each_entry(child
, &event
->child_list
, child_list
)
3176 mutex_unlock(&event
->child_mutex
);
3179 static void perf_event_for_each(struct perf_event
*event
,
3180 void (*func
)(struct perf_event
*))
3182 struct perf_event_context
*ctx
= event
->ctx
;
3183 struct perf_event
*sibling
;
3185 WARN_ON_ONCE(ctx
->parent_ctx
);
3186 mutex_lock(&ctx
->mutex
);
3187 event
= event
->group_leader
;
3189 perf_event_for_each_child(event
, func
);
3190 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3191 perf_event_for_each_child(sibling
, 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 static int perf_event_index(struct perf_event
*event
)
3334 if (event
->hw
.state
& PERF_HES_STOPPED
)
3337 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3340 return event
->pmu
->event_idx(event
);
3343 static void calc_timer_values(struct perf_event
*event
,
3350 *now
= perf_clock();
3351 ctx_time
= event
->shadow_ctx_time
+ *now
;
3352 *enabled
= ctx_time
- event
->tstamp_enabled
;
3353 *running
= ctx_time
- event
->tstamp_running
;
3356 void __weak
arch_perf_update_userpage(struct perf_event_mmap_page
*userpg
, u64 now
)
3361 * Callers need to ensure there can be no nesting of this function, otherwise
3362 * the seqlock logic goes bad. We can not serialize this because the arch
3363 * code calls this from NMI context.
3365 void perf_event_update_userpage(struct perf_event
*event
)
3367 struct perf_event_mmap_page
*userpg
;
3368 struct ring_buffer
*rb
;
3369 u64 enabled
, running
, now
;
3373 * compute total_time_enabled, total_time_running
3374 * based on snapshot values taken when the event
3375 * was last scheduled in.
3377 * we cannot simply called update_context_time()
3378 * because of locking issue as we can be called in
3381 calc_timer_values(event
, &now
, &enabled
, &running
);
3382 rb
= rcu_dereference(event
->rb
);
3386 userpg
= rb
->user_page
;
3389 * Disable preemption so as to not let the corresponding user-space
3390 * spin too long if we get preempted.
3395 userpg
->index
= perf_event_index(event
);
3396 userpg
->offset
= perf_event_count(event
);
3398 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3400 userpg
->time_enabled
= enabled
+
3401 atomic64_read(&event
->child_total_time_enabled
);
3403 userpg
->time_running
= running
+
3404 atomic64_read(&event
->child_total_time_running
);
3406 arch_perf_update_userpage(userpg
, now
);
3415 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3417 struct perf_event
*event
= vma
->vm_file
->private_data
;
3418 struct ring_buffer
*rb
;
3419 int ret
= VM_FAULT_SIGBUS
;
3421 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3422 if (vmf
->pgoff
== 0)
3428 rb
= rcu_dereference(event
->rb
);
3432 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3435 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3439 get_page(vmf
->page
);
3440 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3441 vmf
->page
->index
= vmf
->pgoff
;
3450 static void ring_buffer_attach(struct perf_event
*event
,
3451 struct ring_buffer
*rb
)
3453 unsigned long flags
;
3455 if (!list_empty(&event
->rb_entry
))
3458 spin_lock_irqsave(&rb
->event_lock
, flags
);
3459 if (!list_empty(&event
->rb_entry
))
3462 list_add(&event
->rb_entry
, &rb
->event_list
);
3464 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3467 static void ring_buffer_detach(struct perf_event
*event
,
3468 struct ring_buffer
*rb
)
3470 unsigned long flags
;
3472 if (list_empty(&event
->rb_entry
))
3475 spin_lock_irqsave(&rb
->event_lock
, flags
);
3476 list_del_init(&event
->rb_entry
);
3477 wake_up_all(&event
->waitq
);
3478 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3481 static void ring_buffer_wakeup(struct perf_event
*event
)
3483 struct ring_buffer
*rb
;
3486 rb
= rcu_dereference(event
->rb
);
3490 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
3491 wake_up_all(&event
->waitq
);
3497 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3499 struct ring_buffer
*rb
;
3501 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3505 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3507 struct ring_buffer
*rb
;
3510 rb
= rcu_dereference(event
->rb
);
3512 if (!atomic_inc_not_zero(&rb
->refcount
))
3520 static void ring_buffer_put(struct ring_buffer
*rb
)
3522 struct perf_event
*event
, *n
;
3523 unsigned long flags
;
3525 if (!atomic_dec_and_test(&rb
->refcount
))
3528 spin_lock_irqsave(&rb
->event_lock
, flags
);
3529 list_for_each_entry_safe(event
, n
, &rb
->event_list
, rb_entry
) {
3530 list_del_init(&event
->rb_entry
);
3531 wake_up_all(&event
->waitq
);
3533 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3535 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3538 static void perf_mmap_open(struct vm_area_struct
*vma
)
3540 struct perf_event
*event
= vma
->vm_file
->private_data
;
3542 atomic_inc(&event
->mmap_count
);
3545 static void perf_mmap_close(struct vm_area_struct
*vma
)
3547 struct perf_event
*event
= vma
->vm_file
->private_data
;
3549 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3550 unsigned long size
= perf_data_size(event
->rb
);
3551 struct user_struct
*user
= event
->mmap_user
;
3552 struct ring_buffer
*rb
= event
->rb
;
3554 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3555 vma
->vm_mm
->pinned_vm
-= event
->mmap_locked
;
3556 rcu_assign_pointer(event
->rb
, NULL
);
3557 ring_buffer_detach(event
, rb
);
3558 mutex_unlock(&event
->mmap_mutex
);
3560 ring_buffer_put(rb
);
3565 static const struct vm_operations_struct perf_mmap_vmops
= {
3566 .open
= perf_mmap_open
,
3567 .close
= perf_mmap_close
,
3568 .fault
= perf_mmap_fault
,
3569 .page_mkwrite
= perf_mmap_fault
,
3572 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3574 struct perf_event
*event
= file
->private_data
;
3575 unsigned long user_locked
, user_lock_limit
;
3576 struct user_struct
*user
= current_user();
3577 unsigned long locked
, lock_limit
;
3578 struct ring_buffer
*rb
;
3579 unsigned long vma_size
;
3580 unsigned long nr_pages
;
3581 long user_extra
, extra
;
3582 int ret
= 0, flags
= 0;
3585 * Don't allow mmap() of inherited per-task counters. This would
3586 * create a performance issue due to all children writing to the
3589 if (event
->cpu
== -1 && event
->attr
.inherit
)
3592 if (!(vma
->vm_flags
& VM_SHARED
))
3595 vma_size
= vma
->vm_end
- vma
->vm_start
;
3596 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3599 * If we have rb pages ensure they're a power-of-two number, so we
3600 * can do bitmasks instead of modulo.
3602 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3605 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3608 if (vma
->vm_pgoff
!= 0)
3611 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3612 mutex_lock(&event
->mmap_mutex
);
3614 if (event
->rb
->nr_pages
== nr_pages
)
3615 atomic_inc(&event
->rb
->refcount
);
3621 user_extra
= nr_pages
+ 1;
3622 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3625 * Increase the limit linearly with more CPUs:
3627 user_lock_limit
*= num_online_cpus();
3629 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3632 if (user_locked
> user_lock_limit
)
3633 extra
= user_locked
- user_lock_limit
;
3635 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3636 lock_limit
>>= PAGE_SHIFT
;
3637 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
3639 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3640 !capable(CAP_IPC_LOCK
)) {
3647 if (vma
->vm_flags
& VM_WRITE
)
3648 flags
|= RING_BUFFER_WRITABLE
;
3650 rb
= rb_alloc(nr_pages
,
3651 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
3658 rcu_assign_pointer(event
->rb
, rb
);
3660 atomic_long_add(user_extra
, &user
->locked_vm
);
3661 event
->mmap_locked
= extra
;
3662 event
->mmap_user
= get_current_user();
3663 vma
->vm_mm
->pinned_vm
+= event
->mmap_locked
;
3665 perf_event_update_userpage(event
);
3669 atomic_inc(&event
->mmap_count
);
3670 mutex_unlock(&event
->mmap_mutex
);
3672 vma
->vm_flags
|= VM_RESERVED
;
3673 vma
->vm_ops
= &perf_mmap_vmops
;
3678 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3680 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3681 struct perf_event
*event
= filp
->private_data
;
3684 mutex_lock(&inode
->i_mutex
);
3685 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3686 mutex_unlock(&inode
->i_mutex
);
3694 static const struct file_operations perf_fops
= {
3695 .llseek
= no_llseek
,
3696 .release
= perf_release
,
3699 .unlocked_ioctl
= perf_ioctl
,
3700 .compat_ioctl
= perf_ioctl
,
3702 .fasync
= perf_fasync
,
3708 * If there's data, ensure we set the poll() state and publish everything
3709 * to user-space before waking everybody up.
3712 void perf_event_wakeup(struct perf_event
*event
)
3714 ring_buffer_wakeup(event
);
3716 if (event
->pending_kill
) {
3717 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3718 event
->pending_kill
= 0;
3722 static void perf_pending_event(struct irq_work
*entry
)
3724 struct perf_event
*event
= container_of(entry
,
3725 struct perf_event
, pending
);
3727 if (event
->pending_disable
) {
3728 event
->pending_disable
= 0;
3729 __perf_event_disable(event
);
3732 if (event
->pending_wakeup
) {
3733 event
->pending_wakeup
= 0;
3734 perf_event_wakeup(event
);
3739 * We assume there is only KVM supporting the callbacks.
3740 * Later on, we might change it to a list if there is
3741 * another virtualization implementation supporting the callbacks.
3743 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3745 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3747 perf_guest_cbs
= cbs
;
3750 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3752 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3754 perf_guest_cbs
= NULL
;
3757 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3759 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3760 struct perf_sample_data
*data
,
3761 struct perf_event
*event
)
3763 u64 sample_type
= event
->attr
.sample_type
;
3765 data
->type
= sample_type
;
3766 header
->size
+= event
->id_header_size
;
3768 if (sample_type
& PERF_SAMPLE_TID
) {
3769 /* namespace issues */
3770 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3771 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3774 if (sample_type
& PERF_SAMPLE_TIME
)
3775 data
->time
= perf_clock();
3777 if (sample_type
& PERF_SAMPLE_ID
)
3778 data
->id
= primary_event_id(event
);
3780 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3781 data
->stream_id
= event
->id
;
3783 if (sample_type
& PERF_SAMPLE_CPU
) {
3784 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3785 data
->cpu_entry
.reserved
= 0;
3789 void perf_event_header__init_id(struct perf_event_header
*header
,
3790 struct perf_sample_data
*data
,
3791 struct perf_event
*event
)
3793 if (event
->attr
.sample_id_all
)
3794 __perf_event_header__init_id(header
, data
, event
);
3797 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
3798 struct perf_sample_data
*data
)
3800 u64 sample_type
= data
->type
;
3802 if (sample_type
& PERF_SAMPLE_TID
)
3803 perf_output_put(handle
, data
->tid_entry
);
3805 if (sample_type
& PERF_SAMPLE_TIME
)
3806 perf_output_put(handle
, data
->time
);
3808 if (sample_type
& PERF_SAMPLE_ID
)
3809 perf_output_put(handle
, data
->id
);
3811 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3812 perf_output_put(handle
, data
->stream_id
);
3814 if (sample_type
& PERF_SAMPLE_CPU
)
3815 perf_output_put(handle
, data
->cpu_entry
);
3818 void perf_event__output_id_sample(struct perf_event
*event
,
3819 struct perf_output_handle
*handle
,
3820 struct perf_sample_data
*sample
)
3822 if (event
->attr
.sample_id_all
)
3823 __perf_event__output_id_sample(handle
, sample
);
3826 static void perf_output_read_one(struct perf_output_handle
*handle
,
3827 struct perf_event
*event
,
3828 u64 enabled
, u64 running
)
3830 u64 read_format
= event
->attr
.read_format
;
3834 values
[n
++] = perf_event_count(event
);
3835 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3836 values
[n
++] = enabled
+
3837 atomic64_read(&event
->child_total_time_enabled
);
3839 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3840 values
[n
++] = running
+
3841 atomic64_read(&event
->child_total_time_running
);
3843 if (read_format
& PERF_FORMAT_ID
)
3844 values
[n
++] = primary_event_id(event
);
3846 __output_copy(handle
, values
, n
* sizeof(u64
));
3850 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3852 static void perf_output_read_group(struct perf_output_handle
*handle
,
3853 struct perf_event
*event
,
3854 u64 enabled
, u64 running
)
3856 struct perf_event
*leader
= event
->group_leader
, *sub
;
3857 u64 read_format
= event
->attr
.read_format
;
3861 values
[n
++] = 1 + leader
->nr_siblings
;
3863 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3864 values
[n
++] = enabled
;
3866 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3867 values
[n
++] = running
;
3869 if (leader
!= event
)
3870 leader
->pmu
->read(leader
);
3872 values
[n
++] = perf_event_count(leader
);
3873 if (read_format
& PERF_FORMAT_ID
)
3874 values
[n
++] = primary_event_id(leader
);
3876 __output_copy(handle
, values
, n
* sizeof(u64
));
3878 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3882 sub
->pmu
->read(sub
);
3884 values
[n
++] = perf_event_count(sub
);
3885 if (read_format
& PERF_FORMAT_ID
)
3886 values
[n
++] = primary_event_id(sub
);
3888 __output_copy(handle
, values
, n
* sizeof(u64
));
3892 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
3893 PERF_FORMAT_TOTAL_TIME_RUNNING)
3895 static void perf_output_read(struct perf_output_handle
*handle
,
3896 struct perf_event
*event
)
3898 u64 enabled
= 0, running
= 0, now
;
3899 u64 read_format
= event
->attr
.read_format
;
3902 * compute total_time_enabled, total_time_running
3903 * based on snapshot values taken when the event
3904 * was last scheduled in.
3906 * we cannot simply called update_context_time()
3907 * because of locking issue as we are called in
3910 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
3911 calc_timer_values(event
, &now
, &enabled
, &running
);
3913 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3914 perf_output_read_group(handle
, event
, enabled
, running
);
3916 perf_output_read_one(handle
, event
, enabled
, running
);
3919 void perf_output_sample(struct perf_output_handle
*handle
,
3920 struct perf_event_header
*header
,
3921 struct perf_sample_data
*data
,
3922 struct perf_event
*event
)
3924 u64 sample_type
= data
->type
;
3926 perf_output_put(handle
, *header
);
3928 if (sample_type
& PERF_SAMPLE_IP
)
3929 perf_output_put(handle
, data
->ip
);
3931 if (sample_type
& PERF_SAMPLE_TID
)
3932 perf_output_put(handle
, data
->tid_entry
);
3934 if (sample_type
& PERF_SAMPLE_TIME
)
3935 perf_output_put(handle
, data
->time
);
3937 if (sample_type
& PERF_SAMPLE_ADDR
)
3938 perf_output_put(handle
, data
->addr
);
3940 if (sample_type
& PERF_SAMPLE_ID
)
3941 perf_output_put(handle
, data
->id
);
3943 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3944 perf_output_put(handle
, data
->stream_id
);
3946 if (sample_type
& PERF_SAMPLE_CPU
)
3947 perf_output_put(handle
, data
->cpu_entry
);
3949 if (sample_type
& PERF_SAMPLE_PERIOD
)
3950 perf_output_put(handle
, data
->period
);
3952 if (sample_type
& PERF_SAMPLE_READ
)
3953 perf_output_read(handle
, event
);
3955 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3956 if (data
->callchain
) {
3959 if (data
->callchain
)
3960 size
+= data
->callchain
->nr
;
3962 size
*= sizeof(u64
);
3964 __output_copy(handle
, data
->callchain
, size
);
3967 perf_output_put(handle
, nr
);
3971 if (sample_type
& PERF_SAMPLE_RAW
) {
3973 perf_output_put(handle
, data
->raw
->size
);
3974 __output_copy(handle
, data
->raw
->data
,
3981 .size
= sizeof(u32
),
3984 perf_output_put(handle
, raw
);
3988 if (!event
->attr
.watermark
) {
3989 int wakeup_events
= event
->attr
.wakeup_events
;
3991 if (wakeup_events
) {
3992 struct ring_buffer
*rb
= handle
->rb
;
3993 int events
= local_inc_return(&rb
->events
);
3995 if (events
>= wakeup_events
) {
3996 local_sub(wakeup_events
, &rb
->events
);
3997 local_inc(&rb
->wakeup
);
4002 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4003 if (data
->br_stack
) {
4006 size
= data
->br_stack
->nr
4007 * sizeof(struct perf_branch_entry
);
4009 perf_output_put(handle
, data
->br_stack
->nr
);
4010 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
4013 * we always store at least the value of nr
4016 perf_output_put(handle
, nr
);
4021 void perf_prepare_sample(struct perf_event_header
*header
,
4022 struct perf_sample_data
*data
,
4023 struct perf_event
*event
,
4024 struct pt_regs
*regs
)
4026 u64 sample_type
= event
->attr
.sample_type
;
4028 header
->type
= PERF_RECORD_SAMPLE
;
4029 header
->size
= sizeof(*header
) + event
->header_size
;
4032 header
->misc
|= perf_misc_flags(regs
);
4034 __perf_event_header__init_id(header
, data
, event
);
4036 if (sample_type
& PERF_SAMPLE_IP
)
4037 data
->ip
= perf_instruction_pointer(regs
);
4039 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4042 data
->callchain
= perf_callchain(regs
);
4044 if (data
->callchain
)
4045 size
+= data
->callchain
->nr
;
4047 header
->size
+= size
* sizeof(u64
);
4050 if (sample_type
& PERF_SAMPLE_RAW
) {
4051 int size
= sizeof(u32
);
4054 size
+= data
->raw
->size
;
4056 size
+= sizeof(u32
);
4058 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4059 header
->size
+= size
;
4062 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4063 int size
= sizeof(u64
); /* nr */
4064 if (data
->br_stack
) {
4065 size
+= data
->br_stack
->nr
4066 * sizeof(struct perf_branch_entry
);
4068 header
->size
+= size
;
4072 static void perf_event_output(struct perf_event
*event
,
4073 struct perf_sample_data
*data
,
4074 struct pt_regs
*regs
)
4076 struct perf_output_handle handle
;
4077 struct perf_event_header header
;
4079 /* protect the callchain buffers */
4082 perf_prepare_sample(&header
, data
, event
, regs
);
4084 if (perf_output_begin(&handle
, event
, header
.size
))
4087 perf_output_sample(&handle
, &header
, data
, event
);
4089 perf_output_end(&handle
);
4099 struct perf_read_event
{
4100 struct perf_event_header header
;
4107 perf_event_read_event(struct perf_event
*event
,
4108 struct task_struct
*task
)
4110 struct perf_output_handle handle
;
4111 struct perf_sample_data sample
;
4112 struct perf_read_event read_event
= {
4114 .type
= PERF_RECORD_READ
,
4116 .size
= sizeof(read_event
) + event
->read_size
,
4118 .pid
= perf_event_pid(event
, task
),
4119 .tid
= perf_event_tid(event
, task
),
4123 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4124 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
4128 perf_output_put(&handle
, read_event
);
4129 perf_output_read(&handle
, event
);
4130 perf_event__output_id_sample(event
, &handle
, &sample
);
4132 perf_output_end(&handle
);
4136 * task tracking -- fork/exit
4138 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
4141 struct perf_task_event
{
4142 struct task_struct
*task
;
4143 struct perf_event_context
*task_ctx
;
4146 struct perf_event_header header
;
4156 static void perf_event_task_output(struct perf_event
*event
,
4157 struct perf_task_event
*task_event
)
4159 struct perf_output_handle handle
;
4160 struct perf_sample_data sample
;
4161 struct task_struct
*task
= task_event
->task
;
4162 int ret
, size
= task_event
->event_id
.header
.size
;
4164 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4166 ret
= perf_output_begin(&handle
, event
,
4167 task_event
->event_id
.header
.size
);
4171 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4172 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4174 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4175 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4177 perf_output_put(&handle
, task_event
->event_id
);
4179 perf_event__output_id_sample(event
, &handle
, &sample
);
4181 perf_output_end(&handle
);
4183 task_event
->event_id
.header
.size
= size
;
4186 static int perf_event_task_match(struct perf_event
*event
)
4188 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4191 if (!event_filter_match(event
))
4194 if (event
->attr
.comm
|| event
->attr
.mmap
||
4195 event
->attr
.mmap_data
|| event
->attr
.task
)
4201 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
4202 struct perf_task_event
*task_event
)
4204 struct perf_event
*event
;
4206 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4207 if (perf_event_task_match(event
))
4208 perf_event_task_output(event
, task_event
);
4212 static void perf_event_task_event(struct perf_task_event
*task_event
)
4214 struct perf_cpu_context
*cpuctx
;
4215 struct perf_event_context
*ctx
;
4220 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4221 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4222 if (cpuctx
->active_pmu
!= pmu
)
4224 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
4226 ctx
= task_event
->task_ctx
;
4228 ctxn
= pmu
->task_ctx_nr
;
4231 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4234 perf_event_task_ctx(ctx
, task_event
);
4236 put_cpu_ptr(pmu
->pmu_cpu_context
);
4241 static void perf_event_task(struct task_struct
*task
,
4242 struct perf_event_context
*task_ctx
,
4245 struct perf_task_event task_event
;
4247 if (!atomic_read(&nr_comm_events
) &&
4248 !atomic_read(&nr_mmap_events
) &&
4249 !atomic_read(&nr_task_events
))
4252 task_event
= (struct perf_task_event
){
4254 .task_ctx
= task_ctx
,
4257 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4259 .size
= sizeof(task_event
.event_id
),
4265 .time
= perf_clock(),
4269 perf_event_task_event(&task_event
);
4272 void perf_event_fork(struct task_struct
*task
)
4274 perf_event_task(task
, NULL
, 1);
4281 struct perf_comm_event
{
4282 struct task_struct
*task
;
4287 struct perf_event_header header
;
4294 static void perf_event_comm_output(struct perf_event
*event
,
4295 struct perf_comm_event
*comm_event
)
4297 struct perf_output_handle handle
;
4298 struct perf_sample_data sample
;
4299 int size
= comm_event
->event_id
.header
.size
;
4302 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4303 ret
= perf_output_begin(&handle
, event
,
4304 comm_event
->event_id
.header
.size
);
4309 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4310 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4312 perf_output_put(&handle
, comm_event
->event_id
);
4313 __output_copy(&handle
, comm_event
->comm
,
4314 comm_event
->comm_size
);
4316 perf_event__output_id_sample(event
, &handle
, &sample
);
4318 perf_output_end(&handle
);
4320 comm_event
->event_id
.header
.size
= size
;
4323 static int perf_event_comm_match(struct perf_event
*event
)
4325 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4328 if (!event_filter_match(event
))
4331 if (event
->attr
.comm
)
4337 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4338 struct perf_comm_event
*comm_event
)
4340 struct perf_event
*event
;
4342 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4343 if (perf_event_comm_match(event
))
4344 perf_event_comm_output(event
, comm_event
);
4348 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4350 struct perf_cpu_context
*cpuctx
;
4351 struct perf_event_context
*ctx
;
4352 char comm
[TASK_COMM_LEN
];
4357 memset(comm
, 0, sizeof(comm
));
4358 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4359 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4361 comm_event
->comm
= comm
;
4362 comm_event
->comm_size
= size
;
4364 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4366 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4367 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4368 if (cpuctx
->active_pmu
!= pmu
)
4370 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4372 ctxn
= pmu
->task_ctx_nr
;
4376 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4378 perf_event_comm_ctx(ctx
, comm_event
);
4380 put_cpu_ptr(pmu
->pmu_cpu_context
);
4385 void perf_event_comm(struct task_struct
*task
)
4387 struct perf_comm_event comm_event
;
4388 struct perf_event_context
*ctx
;
4391 for_each_task_context_nr(ctxn
) {
4392 ctx
= task
->perf_event_ctxp
[ctxn
];
4396 perf_event_enable_on_exec(ctx
);
4399 if (!atomic_read(&nr_comm_events
))
4402 comm_event
= (struct perf_comm_event
){
4408 .type
= PERF_RECORD_COMM
,
4417 perf_event_comm_event(&comm_event
);
4424 struct perf_mmap_event
{
4425 struct vm_area_struct
*vma
;
4427 const char *file_name
;
4431 struct perf_event_header header
;
4441 static void perf_event_mmap_output(struct perf_event
*event
,
4442 struct perf_mmap_event
*mmap_event
)
4444 struct perf_output_handle handle
;
4445 struct perf_sample_data sample
;
4446 int size
= mmap_event
->event_id
.header
.size
;
4449 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4450 ret
= perf_output_begin(&handle
, event
,
4451 mmap_event
->event_id
.header
.size
);
4455 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4456 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4458 perf_output_put(&handle
, mmap_event
->event_id
);
4459 __output_copy(&handle
, mmap_event
->file_name
,
4460 mmap_event
->file_size
);
4462 perf_event__output_id_sample(event
, &handle
, &sample
);
4464 perf_output_end(&handle
);
4466 mmap_event
->event_id
.header
.size
= size
;
4469 static int perf_event_mmap_match(struct perf_event
*event
,
4470 struct perf_mmap_event
*mmap_event
,
4473 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4476 if (!event_filter_match(event
))
4479 if ((!executable
&& event
->attr
.mmap_data
) ||
4480 (executable
&& event
->attr
.mmap
))
4486 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4487 struct perf_mmap_event
*mmap_event
,
4490 struct perf_event
*event
;
4492 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4493 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4494 perf_event_mmap_output(event
, mmap_event
);
4498 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4500 struct perf_cpu_context
*cpuctx
;
4501 struct perf_event_context
*ctx
;
4502 struct vm_area_struct
*vma
= mmap_event
->vma
;
4503 struct file
*file
= vma
->vm_file
;
4511 memset(tmp
, 0, sizeof(tmp
));
4515 * d_path works from the end of the rb backwards, so we
4516 * need to add enough zero bytes after the string to handle
4517 * the 64bit alignment we do later.
4519 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4521 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4524 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4526 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4530 if (arch_vma_name(mmap_event
->vma
)) {
4531 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4537 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4539 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4540 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4541 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4543 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4544 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4545 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4549 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4554 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4556 mmap_event
->file_name
= name
;
4557 mmap_event
->file_size
= size
;
4559 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4562 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4563 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4564 if (cpuctx
->active_pmu
!= pmu
)
4566 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4567 vma
->vm_flags
& VM_EXEC
);
4569 ctxn
= pmu
->task_ctx_nr
;
4573 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4575 perf_event_mmap_ctx(ctx
, mmap_event
,
4576 vma
->vm_flags
& VM_EXEC
);
4579 put_cpu_ptr(pmu
->pmu_cpu_context
);
4586 void perf_event_mmap(struct vm_area_struct
*vma
)
4588 struct perf_mmap_event mmap_event
;
4590 if (!atomic_read(&nr_mmap_events
))
4593 mmap_event
= (struct perf_mmap_event
){
4599 .type
= PERF_RECORD_MMAP
,
4600 .misc
= PERF_RECORD_MISC_USER
,
4605 .start
= vma
->vm_start
,
4606 .len
= vma
->vm_end
- vma
->vm_start
,
4607 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4611 perf_event_mmap_event(&mmap_event
);
4615 * IRQ throttle logging
4618 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4620 struct perf_output_handle handle
;
4621 struct perf_sample_data sample
;
4625 struct perf_event_header header
;
4629 } throttle_event
= {
4631 .type
= PERF_RECORD_THROTTLE
,
4633 .size
= sizeof(throttle_event
),
4635 .time
= perf_clock(),
4636 .id
= primary_event_id(event
),
4637 .stream_id
= event
->id
,
4641 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4643 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4645 ret
= perf_output_begin(&handle
, event
,
4646 throttle_event
.header
.size
);
4650 perf_output_put(&handle
, throttle_event
);
4651 perf_event__output_id_sample(event
, &handle
, &sample
);
4652 perf_output_end(&handle
);
4656 * Generic event overflow handling, sampling.
4659 static int __perf_event_overflow(struct perf_event
*event
,
4660 int throttle
, struct perf_sample_data
*data
,
4661 struct pt_regs
*regs
)
4663 int events
= atomic_read(&event
->event_limit
);
4664 struct hw_perf_event
*hwc
= &event
->hw
;
4669 * Non-sampling counters might still use the PMI to fold short
4670 * hardware counters, ignore those.
4672 if (unlikely(!is_sampling_event(event
)))
4675 seq
= __this_cpu_read(perf_throttled_seq
);
4676 if (seq
!= hwc
->interrupts_seq
) {
4677 hwc
->interrupts_seq
= seq
;
4678 hwc
->interrupts
= 1;
4681 if (unlikely(throttle
4682 && hwc
->interrupts
>= max_samples_per_tick
)) {
4683 __this_cpu_inc(perf_throttled_count
);
4684 hwc
->interrupts
= MAX_INTERRUPTS
;
4685 perf_log_throttle(event
, 0);
4690 if (event
->attr
.freq
) {
4691 u64 now
= perf_clock();
4692 s64 delta
= now
- hwc
->freq_time_stamp
;
4694 hwc
->freq_time_stamp
= now
;
4696 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4697 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
4701 * XXX event_limit might not quite work as expected on inherited
4705 event
->pending_kill
= POLL_IN
;
4706 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4708 event
->pending_kill
= POLL_HUP
;
4709 event
->pending_disable
= 1;
4710 irq_work_queue(&event
->pending
);
4713 if (event
->overflow_handler
)
4714 event
->overflow_handler(event
, data
, regs
);
4716 perf_event_output(event
, data
, regs
);
4718 if (event
->fasync
&& event
->pending_kill
) {
4719 event
->pending_wakeup
= 1;
4720 irq_work_queue(&event
->pending
);
4726 int perf_event_overflow(struct perf_event
*event
,
4727 struct perf_sample_data
*data
,
4728 struct pt_regs
*regs
)
4730 return __perf_event_overflow(event
, 1, data
, regs
);
4734 * Generic software event infrastructure
4737 struct swevent_htable
{
4738 struct swevent_hlist
*swevent_hlist
;
4739 struct mutex hlist_mutex
;
4742 /* Recursion avoidance in each contexts */
4743 int recursion
[PERF_NR_CONTEXTS
];
4746 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
4749 * We directly increment event->count and keep a second value in
4750 * event->hw.period_left to count intervals. This period event
4751 * is kept in the range [-sample_period, 0] so that we can use the
4755 static u64
perf_swevent_set_period(struct perf_event
*event
)
4757 struct hw_perf_event
*hwc
= &event
->hw
;
4758 u64 period
= hwc
->last_period
;
4762 hwc
->last_period
= hwc
->sample_period
;
4765 old
= val
= local64_read(&hwc
->period_left
);
4769 nr
= div64_u64(period
+ val
, period
);
4770 offset
= nr
* period
;
4772 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
4778 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
4779 struct perf_sample_data
*data
,
4780 struct pt_regs
*regs
)
4782 struct hw_perf_event
*hwc
= &event
->hw
;
4786 overflow
= perf_swevent_set_period(event
);
4788 if (hwc
->interrupts
== MAX_INTERRUPTS
)
4791 for (; overflow
; overflow
--) {
4792 if (__perf_event_overflow(event
, throttle
,
4795 * We inhibit the overflow from happening when
4796 * hwc->interrupts == MAX_INTERRUPTS.
4804 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
4805 struct perf_sample_data
*data
,
4806 struct pt_regs
*regs
)
4808 struct hw_perf_event
*hwc
= &event
->hw
;
4810 local64_add(nr
, &event
->count
);
4815 if (!is_sampling_event(event
))
4818 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
4820 return perf_swevent_overflow(event
, 1, data
, regs
);
4822 data
->period
= event
->hw
.last_period
;
4824 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
4825 return perf_swevent_overflow(event
, 1, data
, regs
);
4827 if (local64_add_negative(nr
, &hwc
->period_left
))
4830 perf_swevent_overflow(event
, 0, data
, regs
);
4833 static int perf_exclude_event(struct perf_event
*event
,
4834 struct pt_regs
*regs
)
4836 if (event
->hw
.state
& PERF_HES_STOPPED
)
4840 if (event
->attr
.exclude_user
&& user_mode(regs
))
4843 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4850 static int perf_swevent_match(struct perf_event
*event
,
4851 enum perf_type_id type
,
4853 struct perf_sample_data
*data
,
4854 struct pt_regs
*regs
)
4856 if (event
->attr
.type
!= type
)
4859 if (event
->attr
.config
!= event_id
)
4862 if (perf_exclude_event(event
, regs
))
4868 static inline u64
swevent_hash(u64 type
, u32 event_id
)
4870 u64 val
= event_id
| (type
<< 32);
4872 return hash_64(val
, SWEVENT_HLIST_BITS
);
4875 static inline struct hlist_head
*
4876 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
4878 u64 hash
= swevent_hash(type
, event_id
);
4880 return &hlist
->heads
[hash
];
4883 /* For the read side: events when they trigger */
4884 static inline struct hlist_head
*
4885 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
4887 struct swevent_hlist
*hlist
;
4889 hlist
= rcu_dereference(swhash
->swevent_hlist
);
4893 return __find_swevent_head(hlist
, type
, event_id
);
4896 /* For the event head insertion and removal in the hlist */
4897 static inline struct hlist_head
*
4898 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
4900 struct swevent_hlist
*hlist
;
4901 u32 event_id
= event
->attr
.config
;
4902 u64 type
= event
->attr
.type
;
4905 * Event scheduling is always serialized against hlist allocation
4906 * and release. Which makes the protected version suitable here.
4907 * The context lock guarantees that.
4909 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
4910 lockdep_is_held(&event
->ctx
->lock
));
4914 return __find_swevent_head(hlist
, type
, event_id
);
4917 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4919 struct perf_sample_data
*data
,
4920 struct pt_regs
*regs
)
4922 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4923 struct perf_event
*event
;
4924 struct hlist_node
*node
;
4925 struct hlist_head
*head
;
4928 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
4932 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4933 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4934 perf_swevent_event(event
, nr
, data
, regs
);
4940 int perf_swevent_get_recursion_context(void)
4942 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4944 return get_recursion_context(swhash
->recursion
);
4946 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4948 inline void perf_swevent_put_recursion_context(int rctx
)
4950 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4952 put_recursion_context(swhash
->recursion
, rctx
);
4955 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
4957 struct perf_sample_data data
;
4960 preempt_disable_notrace();
4961 rctx
= perf_swevent_get_recursion_context();
4965 perf_sample_data_init(&data
, addr
, 0);
4967 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
4969 perf_swevent_put_recursion_context(rctx
);
4970 preempt_enable_notrace();
4973 static void perf_swevent_read(struct perf_event
*event
)
4977 static int perf_swevent_add(struct perf_event
*event
, int flags
)
4979 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4980 struct hw_perf_event
*hwc
= &event
->hw
;
4981 struct hlist_head
*head
;
4983 if (is_sampling_event(event
)) {
4984 hwc
->last_period
= hwc
->sample_period
;
4985 perf_swevent_set_period(event
);
4988 hwc
->state
= !(flags
& PERF_EF_START
);
4990 head
= find_swevent_head(swhash
, event
);
4991 if (WARN_ON_ONCE(!head
))
4994 hlist_add_head_rcu(&event
->hlist_entry
, head
);
4999 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5001 hlist_del_rcu(&event
->hlist_entry
);
5004 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5006 event
->hw
.state
= 0;
5009 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5011 event
->hw
.state
= PERF_HES_STOPPED
;
5014 /* Deref the hlist from the update side */
5015 static inline struct swevent_hlist
*
5016 swevent_hlist_deref(struct swevent_htable
*swhash
)
5018 return rcu_dereference_protected(swhash
->swevent_hlist
,
5019 lockdep_is_held(&swhash
->hlist_mutex
));
5022 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5024 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5029 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5030 kfree_rcu(hlist
, rcu_head
);
5033 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5035 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5037 mutex_lock(&swhash
->hlist_mutex
);
5039 if (!--swhash
->hlist_refcount
)
5040 swevent_hlist_release(swhash
);
5042 mutex_unlock(&swhash
->hlist_mutex
);
5045 static void swevent_hlist_put(struct perf_event
*event
)
5049 if (event
->cpu
!= -1) {
5050 swevent_hlist_put_cpu(event
, event
->cpu
);
5054 for_each_possible_cpu(cpu
)
5055 swevent_hlist_put_cpu(event
, cpu
);
5058 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5060 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5063 mutex_lock(&swhash
->hlist_mutex
);
5065 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5066 struct swevent_hlist
*hlist
;
5068 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5073 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5075 swhash
->hlist_refcount
++;
5077 mutex_unlock(&swhash
->hlist_mutex
);
5082 static int swevent_hlist_get(struct perf_event
*event
)
5085 int cpu
, failed_cpu
;
5087 if (event
->cpu
!= -1)
5088 return swevent_hlist_get_cpu(event
, event
->cpu
);
5091 for_each_possible_cpu(cpu
) {
5092 err
= swevent_hlist_get_cpu(event
, cpu
);
5102 for_each_possible_cpu(cpu
) {
5103 if (cpu
== failed_cpu
)
5105 swevent_hlist_put_cpu(event
, cpu
);
5112 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5114 static void sw_perf_event_destroy(struct perf_event
*event
)
5116 u64 event_id
= event
->attr
.config
;
5118 WARN_ON(event
->parent
);
5120 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
5121 swevent_hlist_put(event
);
5124 static int perf_swevent_init(struct perf_event
*event
)
5126 int event_id
= event
->attr
.config
;
5128 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5132 * no branch sampling for software events
5134 if (has_branch_stack(event
))
5138 case PERF_COUNT_SW_CPU_CLOCK
:
5139 case PERF_COUNT_SW_TASK_CLOCK
:
5146 if (event_id
>= PERF_COUNT_SW_MAX
)
5149 if (!event
->parent
) {
5152 err
= swevent_hlist_get(event
);
5156 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
5157 event
->destroy
= sw_perf_event_destroy
;
5163 static int perf_swevent_event_idx(struct perf_event
*event
)
5168 static struct pmu perf_swevent
= {
5169 .task_ctx_nr
= perf_sw_context
,
5171 .event_init
= perf_swevent_init
,
5172 .add
= perf_swevent_add
,
5173 .del
= perf_swevent_del
,
5174 .start
= perf_swevent_start
,
5175 .stop
= perf_swevent_stop
,
5176 .read
= perf_swevent_read
,
5178 .event_idx
= perf_swevent_event_idx
,
5181 #ifdef CONFIG_EVENT_TRACING
5183 static int perf_tp_filter_match(struct perf_event
*event
,
5184 struct perf_sample_data
*data
)
5186 void *record
= data
->raw
->data
;
5188 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5193 static int perf_tp_event_match(struct perf_event
*event
,
5194 struct perf_sample_data
*data
,
5195 struct pt_regs
*regs
)
5197 if (event
->hw
.state
& PERF_HES_STOPPED
)
5200 * All tracepoints are from kernel-space.
5202 if (event
->attr
.exclude_kernel
)
5205 if (!perf_tp_filter_match(event
, data
))
5211 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5212 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
5214 struct perf_sample_data data
;
5215 struct perf_event
*event
;
5216 struct hlist_node
*node
;
5218 struct perf_raw_record raw
= {
5223 perf_sample_data_init(&data
, addr
, 0);
5226 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5227 if (perf_tp_event_match(event
, &data
, regs
))
5228 perf_swevent_event(event
, count
, &data
, regs
);
5231 perf_swevent_put_recursion_context(rctx
);
5233 EXPORT_SYMBOL_GPL(perf_tp_event
);
5235 static void tp_perf_event_destroy(struct perf_event
*event
)
5237 perf_trace_destroy(event
);
5240 static int perf_tp_event_init(struct perf_event
*event
)
5244 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5248 * no branch sampling for tracepoint events
5250 if (has_branch_stack(event
))
5253 err
= perf_trace_init(event
);
5257 event
->destroy
= tp_perf_event_destroy
;
5262 static struct pmu perf_tracepoint
= {
5263 .task_ctx_nr
= perf_sw_context
,
5265 .event_init
= perf_tp_event_init
,
5266 .add
= perf_trace_add
,
5267 .del
= perf_trace_del
,
5268 .start
= perf_swevent_start
,
5269 .stop
= perf_swevent_stop
,
5270 .read
= perf_swevent_read
,
5272 .event_idx
= perf_swevent_event_idx
,
5275 static inline void perf_tp_register(void)
5277 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5280 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5285 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5288 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5289 if (IS_ERR(filter_str
))
5290 return PTR_ERR(filter_str
);
5292 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5298 static void perf_event_free_filter(struct perf_event
*event
)
5300 ftrace_profile_free_filter(event
);
5305 static inline void perf_tp_register(void)
5309 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5314 static void perf_event_free_filter(struct perf_event
*event
)
5318 #endif /* CONFIG_EVENT_TRACING */
5320 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5321 void perf_bp_event(struct perf_event
*bp
, void *data
)
5323 struct perf_sample_data sample
;
5324 struct pt_regs
*regs
= data
;
5326 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
5328 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5329 perf_swevent_event(bp
, 1, &sample
, regs
);
5334 * hrtimer based swevent callback
5337 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5339 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5340 struct perf_sample_data data
;
5341 struct pt_regs
*regs
;
5342 struct perf_event
*event
;
5345 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5347 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5348 return HRTIMER_NORESTART
;
5350 event
->pmu
->read(event
);
5352 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
5353 regs
= get_irq_regs();
5355 if (regs
&& !perf_exclude_event(event
, regs
)) {
5356 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
5357 if (__perf_event_overflow(event
, 1, &data
, regs
))
5358 ret
= HRTIMER_NORESTART
;
5361 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5362 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5367 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5369 struct hw_perf_event
*hwc
= &event
->hw
;
5372 if (!is_sampling_event(event
))
5375 period
= local64_read(&hwc
->period_left
);
5380 local64_set(&hwc
->period_left
, 0);
5382 period
= max_t(u64
, 10000, hwc
->sample_period
);
5384 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5385 ns_to_ktime(period
), 0,
5386 HRTIMER_MODE_REL_PINNED
, 0);
5389 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5391 struct hw_perf_event
*hwc
= &event
->hw
;
5393 if (is_sampling_event(event
)) {
5394 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5395 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5397 hrtimer_cancel(&hwc
->hrtimer
);
5401 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
5403 struct hw_perf_event
*hwc
= &event
->hw
;
5405 if (!is_sampling_event(event
))
5408 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5409 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5412 * Since hrtimers have a fixed rate, we can do a static freq->period
5413 * mapping and avoid the whole period adjust feedback stuff.
5415 if (event
->attr
.freq
) {
5416 long freq
= event
->attr
.sample_freq
;
5418 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
5419 hwc
->sample_period
= event
->attr
.sample_period
;
5420 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5421 event
->attr
.freq
= 0;
5426 * Software event: cpu wall time clock
5429 static void cpu_clock_event_update(struct perf_event
*event
)
5434 now
= local_clock();
5435 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5436 local64_add(now
- prev
, &event
->count
);
5439 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5441 local64_set(&event
->hw
.prev_count
, local_clock());
5442 perf_swevent_start_hrtimer(event
);
5445 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5447 perf_swevent_cancel_hrtimer(event
);
5448 cpu_clock_event_update(event
);
5451 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5453 if (flags
& PERF_EF_START
)
5454 cpu_clock_event_start(event
, flags
);
5459 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5461 cpu_clock_event_stop(event
, flags
);
5464 static void cpu_clock_event_read(struct perf_event
*event
)
5466 cpu_clock_event_update(event
);
5469 static int cpu_clock_event_init(struct perf_event
*event
)
5471 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5474 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5478 * no branch sampling for software events
5480 if (has_branch_stack(event
))
5483 perf_swevent_init_hrtimer(event
);
5488 static struct pmu perf_cpu_clock
= {
5489 .task_ctx_nr
= perf_sw_context
,
5491 .event_init
= cpu_clock_event_init
,
5492 .add
= cpu_clock_event_add
,
5493 .del
= cpu_clock_event_del
,
5494 .start
= cpu_clock_event_start
,
5495 .stop
= cpu_clock_event_stop
,
5496 .read
= cpu_clock_event_read
,
5498 .event_idx
= perf_swevent_event_idx
,
5502 * Software event: task time clock
5505 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5510 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5512 local64_add(delta
, &event
->count
);
5515 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5517 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5518 perf_swevent_start_hrtimer(event
);
5521 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5523 perf_swevent_cancel_hrtimer(event
);
5524 task_clock_event_update(event
, event
->ctx
->time
);
5527 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5529 if (flags
& PERF_EF_START
)
5530 task_clock_event_start(event
, flags
);
5535 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5537 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5540 static void task_clock_event_read(struct perf_event
*event
)
5542 u64 now
= perf_clock();
5543 u64 delta
= now
- event
->ctx
->timestamp
;
5544 u64 time
= event
->ctx
->time
+ delta
;
5546 task_clock_event_update(event
, time
);
5549 static int task_clock_event_init(struct perf_event
*event
)
5551 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5554 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5558 * no branch sampling for software events
5560 if (has_branch_stack(event
))
5563 perf_swevent_init_hrtimer(event
);
5568 static struct pmu perf_task_clock
= {
5569 .task_ctx_nr
= perf_sw_context
,
5571 .event_init
= task_clock_event_init
,
5572 .add
= task_clock_event_add
,
5573 .del
= task_clock_event_del
,
5574 .start
= task_clock_event_start
,
5575 .stop
= task_clock_event_stop
,
5576 .read
= task_clock_event_read
,
5578 .event_idx
= perf_swevent_event_idx
,
5581 static void perf_pmu_nop_void(struct pmu
*pmu
)
5585 static int perf_pmu_nop_int(struct pmu
*pmu
)
5590 static void perf_pmu_start_txn(struct pmu
*pmu
)
5592 perf_pmu_disable(pmu
);
5595 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5597 perf_pmu_enable(pmu
);
5601 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5603 perf_pmu_enable(pmu
);
5606 static int perf_event_idx_default(struct perf_event
*event
)
5608 return event
->hw
.idx
+ 1;
5612 * Ensures all contexts with the same task_ctx_nr have the same
5613 * pmu_cpu_context too.
5615 static void *find_pmu_context(int ctxn
)
5622 list_for_each_entry(pmu
, &pmus
, entry
) {
5623 if (pmu
->task_ctx_nr
== ctxn
)
5624 return pmu
->pmu_cpu_context
;
5630 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5634 for_each_possible_cpu(cpu
) {
5635 struct perf_cpu_context
*cpuctx
;
5637 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5639 if (cpuctx
->active_pmu
== old_pmu
)
5640 cpuctx
->active_pmu
= pmu
;
5644 static void free_pmu_context(struct pmu
*pmu
)
5648 mutex_lock(&pmus_lock
);
5650 * Like a real lame refcount.
5652 list_for_each_entry(i
, &pmus
, entry
) {
5653 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5654 update_pmu_context(i
, pmu
);
5659 free_percpu(pmu
->pmu_cpu_context
);
5661 mutex_unlock(&pmus_lock
);
5663 static struct idr pmu_idr
;
5666 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5668 struct pmu
*pmu
= dev_get_drvdata(dev
);
5670 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5673 static struct device_attribute pmu_dev_attrs
[] = {
5678 static int pmu_bus_running
;
5679 static struct bus_type pmu_bus
= {
5680 .name
= "event_source",
5681 .dev_attrs
= pmu_dev_attrs
,
5684 static void pmu_dev_release(struct device
*dev
)
5689 static int pmu_dev_alloc(struct pmu
*pmu
)
5693 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5697 pmu
->dev
->groups
= pmu
->attr_groups
;
5698 device_initialize(pmu
->dev
);
5699 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5703 dev_set_drvdata(pmu
->dev
, pmu
);
5704 pmu
->dev
->bus
= &pmu_bus
;
5705 pmu
->dev
->release
= pmu_dev_release
;
5706 ret
= device_add(pmu
->dev
);
5714 put_device(pmu
->dev
);
5718 static struct lock_class_key cpuctx_mutex
;
5719 static struct lock_class_key cpuctx_lock
;
5721 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5725 mutex_lock(&pmus_lock
);
5727 pmu
->pmu_disable_count
= alloc_percpu(int);
5728 if (!pmu
->pmu_disable_count
)
5737 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
5741 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
5749 if (pmu_bus_running
) {
5750 ret
= pmu_dev_alloc(pmu
);
5756 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
5757 if (pmu
->pmu_cpu_context
)
5758 goto got_cpu_context
;
5760 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
5761 if (!pmu
->pmu_cpu_context
)
5764 for_each_possible_cpu(cpu
) {
5765 struct perf_cpu_context
*cpuctx
;
5767 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5768 __perf_event_init_context(&cpuctx
->ctx
);
5769 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
5770 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
5771 cpuctx
->ctx
.type
= cpu_context
;
5772 cpuctx
->ctx
.pmu
= pmu
;
5773 cpuctx
->jiffies_interval
= 1;
5774 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
5775 cpuctx
->active_pmu
= pmu
;
5779 if (!pmu
->start_txn
) {
5780 if (pmu
->pmu_enable
) {
5782 * If we have pmu_enable/pmu_disable calls, install
5783 * transaction stubs that use that to try and batch
5784 * hardware accesses.
5786 pmu
->start_txn
= perf_pmu_start_txn
;
5787 pmu
->commit_txn
= perf_pmu_commit_txn
;
5788 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
5790 pmu
->start_txn
= perf_pmu_nop_void
;
5791 pmu
->commit_txn
= perf_pmu_nop_int
;
5792 pmu
->cancel_txn
= perf_pmu_nop_void
;
5796 if (!pmu
->pmu_enable
) {
5797 pmu
->pmu_enable
= perf_pmu_nop_void
;
5798 pmu
->pmu_disable
= perf_pmu_nop_void
;
5801 if (!pmu
->event_idx
)
5802 pmu
->event_idx
= perf_event_idx_default
;
5804 list_add_rcu(&pmu
->entry
, &pmus
);
5807 mutex_unlock(&pmus_lock
);
5812 device_del(pmu
->dev
);
5813 put_device(pmu
->dev
);
5816 if (pmu
->type
>= PERF_TYPE_MAX
)
5817 idr_remove(&pmu_idr
, pmu
->type
);
5820 free_percpu(pmu
->pmu_disable_count
);
5824 void perf_pmu_unregister(struct pmu
*pmu
)
5826 mutex_lock(&pmus_lock
);
5827 list_del_rcu(&pmu
->entry
);
5828 mutex_unlock(&pmus_lock
);
5831 * We dereference the pmu list under both SRCU and regular RCU, so
5832 * synchronize against both of those.
5834 synchronize_srcu(&pmus_srcu
);
5837 free_percpu(pmu
->pmu_disable_count
);
5838 if (pmu
->type
>= PERF_TYPE_MAX
)
5839 idr_remove(&pmu_idr
, pmu
->type
);
5840 device_del(pmu
->dev
);
5841 put_device(pmu
->dev
);
5842 free_pmu_context(pmu
);
5845 struct pmu
*perf_init_event(struct perf_event
*event
)
5847 struct pmu
*pmu
= NULL
;
5851 idx
= srcu_read_lock(&pmus_srcu
);
5854 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
5858 ret
= pmu
->event_init(event
);
5864 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5866 ret
= pmu
->event_init(event
);
5870 if (ret
!= -ENOENT
) {
5875 pmu
= ERR_PTR(-ENOENT
);
5877 srcu_read_unlock(&pmus_srcu
, idx
);
5883 * Allocate and initialize a event structure
5885 static struct perf_event
*
5886 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
5887 struct task_struct
*task
,
5888 struct perf_event
*group_leader
,
5889 struct perf_event
*parent_event
,
5890 perf_overflow_handler_t overflow_handler
,
5894 struct perf_event
*event
;
5895 struct hw_perf_event
*hwc
;
5898 if ((unsigned)cpu
>= nr_cpu_ids
) {
5899 if (!task
|| cpu
!= -1)
5900 return ERR_PTR(-EINVAL
);
5903 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
5905 return ERR_PTR(-ENOMEM
);
5908 * Single events are their own group leaders, with an
5909 * empty sibling list:
5912 group_leader
= event
;
5914 mutex_init(&event
->child_mutex
);
5915 INIT_LIST_HEAD(&event
->child_list
);
5917 INIT_LIST_HEAD(&event
->group_entry
);
5918 INIT_LIST_HEAD(&event
->event_entry
);
5919 INIT_LIST_HEAD(&event
->sibling_list
);
5920 INIT_LIST_HEAD(&event
->rb_entry
);
5922 init_waitqueue_head(&event
->waitq
);
5923 init_irq_work(&event
->pending
, perf_pending_event
);
5925 mutex_init(&event
->mmap_mutex
);
5928 event
->attr
= *attr
;
5929 event
->group_leader
= group_leader
;
5933 event
->parent
= parent_event
;
5935 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
5936 event
->id
= atomic64_inc_return(&perf_event_id
);
5938 event
->state
= PERF_EVENT_STATE_INACTIVE
;
5941 event
->attach_state
= PERF_ATTACH_TASK
;
5942 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5944 * hw_breakpoint is a bit difficult here..
5946 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
5947 event
->hw
.bp_target
= task
;
5951 if (!overflow_handler
&& parent_event
) {
5952 overflow_handler
= parent_event
->overflow_handler
;
5953 context
= parent_event
->overflow_handler_context
;
5956 event
->overflow_handler
= overflow_handler
;
5957 event
->overflow_handler_context
= context
;
5960 event
->state
= PERF_EVENT_STATE_OFF
;
5965 hwc
->sample_period
= attr
->sample_period
;
5966 if (attr
->freq
&& attr
->sample_freq
)
5967 hwc
->sample_period
= 1;
5968 hwc
->last_period
= hwc
->sample_period
;
5970 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5973 * we currently do not support PERF_FORMAT_GROUP on inherited events
5975 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
5978 pmu
= perf_init_event(event
);
5984 else if (IS_ERR(pmu
))
5989 put_pid_ns(event
->ns
);
5991 return ERR_PTR(err
);
5994 if (!event
->parent
) {
5995 if (event
->attach_state
& PERF_ATTACH_TASK
)
5996 static_key_slow_inc(&perf_sched_events
.key
);
5997 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
5998 atomic_inc(&nr_mmap_events
);
5999 if (event
->attr
.comm
)
6000 atomic_inc(&nr_comm_events
);
6001 if (event
->attr
.task
)
6002 atomic_inc(&nr_task_events
);
6003 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6004 err
= get_callchain_buffers();
6007 return ERR_PTR(err
);
6010 if (has_branch_stack(event
)) {
6011 static_key_slow_inc(&perf_sched_events
.key
);
6012 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
6013 atomic_inc(&per_cpu(perf_branch_stack_events
,
6021 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6022 struct perf_event_attr
*attr
)
6027 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6031 * zero the full structure, so that a short copy will be nice.
6033 memset(attr
, 0, sizeof(*attr
));
6035 ret
= get_user(size
, &uattr
->size
);
6039 if (size
> PAGE_SIZE
) /* silly large */
6042 if (!size
) /* abi compat */
6043 size
= PERF_ATTR_SIZE_VER0
;
6045 if (size
< PERF_ATTR_SIZE_VER0
)
6049 * If we're handed a bigger struct than we know of,
6050 * ensure all the unknown bits are 0 - i.e. new
6051 * user-space does not rely on any kernel feature
6052 * extensions we dont know about yet.
6054 if (size
> sizeof(*attr
)) {
6055 unsigned char __user
*addr
;
6056 unsigned char __user
*end
;
6059 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6060 end
= (void __user
*)uattr
+ size
;
6062 for (; addr
< end
; addr
++) {
6063 ret
= get_user(val
, addr
);
6069 size
= sizeof(*attr
);
6072 ret
= copy_from_user(attr
, uattr
, size
);
6076 if (attr
->__reserved_1
)
6079 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6082 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6085 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6086 u64 mask
= attr
->branch_sample_type
;
6088 /* only using defined bits */
6089 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
6092 /* at least one branch bit must be set */
6093 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
6096 /* kernel level capture: check permissions */
6097 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
6098 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6101 /* propagate priv level, when not set for branch */
6102 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
6104 /* exclude_kernel checked on syscall entry */
6105 if (!attr
->exclude_kernel
)
6106 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
6108 if (!attr
->exclude_user
)
6109 mask
|= PERF_SAMPLE_BRANCH_USER
;
6111 if (!attr
->exclude_hv
)
6112 mask
|= PERF_SAMPLE_BRANCH_HV
;
6114 * adjust user setting (for HW filter setup)
6116 attr
->branch_sample_type
= mask
;
6123 put_user(sizeof(*attr
), &uattr
->size
);
6129 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
6131 struct ring_buffer
*rb
= NULL
, *old_rb
= NULL
;
6137 /* don't allow circular references */
6138 if (event
== output_event
)
6142 * Don't allow cross-cpu buffers
6144 if (output_event
->cpu
!= event
->cpu
)
6148 * If its not a per-cpu rb, it must be the same task.
6150 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
6154 mutex_lock(&event
->mmap_mutex
);
6155 /* Can't redirect output if we've got an active mmap() */
6156 if (atomic_read(&event
->mmap_count
))
6160 /* get the rb we want to redirect to */
6161 rb
= ring_buffer_get(output_event
);
6167 rcu_assign_pointer(event
->rb
, rb
);
6169 ring_buffer_detach(event
, old_rb
);
6172 mutex_unlock(&event
->mmap_mutex
);
6175 ring_buffer_put(old_rb
);
6181 * sys_perf_event_open - open a performance event, associate it to a task/cpu
6183 * @attr_uptr: event_id type attributes for monitoring/sampling
6186 * @group_fd: group leader event fd
6188 SYSCALL_DEFINE5(perf_event_open
,
6189 struct perf_event_attr __user
*, attr_uptr
,
6190 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
6192 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
6193 struct perf_event
*event
, *sibling
;
6194 struct perf_event_attr attr
;
6195 struct perf_event_context
*ctx
;
6196 struct file
*event_file
= NULL
;
6197 struct file
*group_file
= NULL
;
6198 struct task_struct
*task
= NULL
;
6202 int fput_needed
= 0;
6205 /* for future expandability... */
6206 if (flags
& ~PERF_FLAG_ALL
)
6209 err
= perf_copy_attr(attr_uptr
, &attr
);
6213 if (!attr
.exclude_kernel
) {
6214 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6219 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
6224 * In cgroup mode, the pid argument is used to pass the fd
6225 * opened to the cgroup directory in cgroupfs. The cpu argument
6226 * designates the cpu on which to monitor threads from that
6229 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
6232 event_fd
= get_unused_fd_flags(O_RDWR
);
6236 if (group_fd
!= -1) {
6237 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
6238 if (IS_ERR(group_leader
)) {
6239 err
= PTR_ERR(group_leader
);
6242 group_file
= group_leader
->filp
;
6243 if (flags
& PERF_FLAG_FD_OUTPUT
)
6244 output_event
= group_leader
;
6245 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6246 group_leader
= NULL
;
6249 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6250 task
= find_lively_task_by_vpid(pid
);
6252 err
= PTR_ERR(task
);
6259 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
6261 if (IS_ERR(event
)) {
6262 err
= PTR_ERR(event
);
6266 if (flags
& PERF_FLAG_PID_CGROUP
) {
6267 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6272 * - that has cgroup constraint on event->cpu
6273 * - that may need work on context switch
6275 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
6276 static_key_slow_inc(&perf_sched_events
.key
);
6280 * Special case software events and allow them to be part of
6281 * any hardware group.
6286 (is_software_event(event
) != is_software_event(group_leader
))) {
6287 if (is_software_event(event
)) {
6289 * If event and group_leader are not both a software
6290 * event, and event is, then group leader is not.
6292 * Allow the addition of software events to !software
6293 * groups, this is safe because software events never
6296 pmu
= group_leader
->pmu
;
6297 } else if (is_software_event(group_leader
) &&
6298 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6300 * In case the group is a pure software group, and we
6301 * try to add a hardware event, move the whole group to
6302 * the hardware context.
6309 * Get the target context (task or percpu):
6311 ctx
= find_get_context(pmu
, task
, event
->cpu
);
6318 put_task_struct(task
);
6323 * Look up the group leader (we will attach this event to it):
6329 * Do not allow a recursive hierarchy (this new sibling
6330 * becoming part of another group-sibling):
6332 if (group_leader
->group_leader
!= group_leader
)
6335 * Do not allow to attach to a group in a different
6336 * task or CPU context:
6339 if (group_leader
->ctx
->type
!= ctx
->type
)
6342 if (group_leader
->ctx
!= ctx
)
6347 * Only a group leader can be exclusive or pinned
6349 if (attr
.exclusive
|| attr
.pinned
)
6354 err
= perf_event_set_output(event
, output_event
);
6359 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6360 if (IS_ERR(event_file
)) {
6361 err
= PTR_ERR(event_file
);
6366 struct perf_event_context
*gctx
= group_leader
->ctx
;
6368 mutex_lock(&gctx
->mutex
);
6369 perf_remove_from_context(group_leader
);
6370 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6372 perf_remove_from_context(sibling
);
6375 mutex_unlock(&gctx
->mutex
);
6379 event
->filp
= event_file
;
6380 WARN_ON_ONCE(ctx
->parent_ctx
);
6381 mutex_lock(&ctx
->mutex
);
6385 perf_install_in_context(ctx
, group_leader
, event
->cpu
);
6387 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6389 perf_install_in_context(ctx
, sibling
, event
->cpu
);
6394 perf_install_in_context(ctx
, event
, event
->cpu
);
6396 perf_unpin_context(ctx
);
6397 mutex_unlock(&ctx
->mutex
);
6401 event
->owner
= current
;
6403 mutex_lock(¤t
->perf_event_mutex
);
6404 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6405 mutex_unlock(¤t
->perf_event_mutex
);
6408 * Precalculate sample_data sizes
6410 perf_event__header_size(event
);
6411 perf_event__id_header_size(event
);
6414 * Drop the reference on the group_event after placing the
6415 * new event on the sibling_list. This ensures destruction
6416 * of the group leader will find the pointer to itself in
6417 * perf_group_detach().
6419 fput_light(group_file
, fput_needed
);
6420 fd_install(event_fd
, event_file
);
6424 perf_unpin_context(ctx
);
6431 put_task_struct(task
);
6433 fput_light(group_file
, fput_needed
);
6435 put_unused_fd(event_fd
);
6440 * perf_event_create_kernel_counter
6442 * @attr: attributes of the counter to create
6443 * @cpu: cpu in which the counter is bound
6444 * @task: task to profile (NULL for percpu)
6447 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6448 struct task_struct
*task
,
6449 perf_overflow_handler_t overflow_handler
,
6452 struct perf_event_context
*ctx
;
6453 struct perf_event
*event
;
6457 * Get the target context (task or percpu):
6460 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
6461 overflow_handler
, context
);
6462 if (IS_ERR(event
)) {
6463 err
= PTR_ERR(event
);
6467 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6474 WARN_ON_ONCE(ctx
->parent_ctx
);
6475 mutex_lock(&ctx
->mutex
);
6476 perf_install_in_context(ctx
, event
, cpu
);
6478 perf_unpin_context(ctx
);
6479 mutex_unlock(&ctx
->mutex
);
6486 return ERR_PTR(err
);
6488 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6490 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
6492 struct perf_event_context
*src_ctx
;
6493 struct perf_event_context
*dst_ctx
;
6494 struct perf_event
*event
, *tmp
;
6497 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
6498 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
6500 mutex_lock(&src_ctx
->mutex
);
6501 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
6503 perf_remove_from_context(event
);
6505 list_add(&event
->event_entry
, &events
);
6507 mutex_unlock(&src_ctx
->mutex
);
6511 mutex_lock(&dst_ctx
->mutex
);
6512 list_for_each_entry_safe(event
, tmp
, &events
, event_entry
) {
6513 list_del(&event
->event_entry
);
6514 if (event
->state
>= PERF_EVENT_STATE_OFF
)
6515 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6516 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
6519 mutex_unlock(&dst_ctx
->mutex
);
6521 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
6523 static void sync_child_event(struct perf_event
*child_event
,
6524 struct task_struct
*child
)
6526 struct perf_event
*parent_event
= child_event
->parent
;
6529 if (child_event
->attr
.inherit_stat
)
6530 perf_event_read_event(child_event
, child
);
6532 child_val
= perf_event_count(child_event
);
6535 * Add back the child's count to the parent's count:
6537 atomic64_add(child_val
, &parent_event
->child_count
);
6538 atomic64_add(child_event
->total_time_enabled
,
6539 &parent_event
->child_total_time_enabled
);
6540 atomic64_add(child_event
->total_time_running
,
6541 &parent_event
->child_total_time_running
);
6544 * Remove this event from the parent's list
6546 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6547 mutex_lock(&parent_event
->child_mutex
);
6548 list_del_init(&child_event
->child_list
);
6549 mutex_unlock(&parent_event
->child_mutex
);
6552 * Release the parent event, if this was the last
6555 fput(parent_event
->filp
);
6559 __perf_event_exit_task(struct perf_event
*child_event
,
6560 struct perf_event_context
*child_ctx
,
6561 struct task_struct
*child
)
6563 if (child_event
->parent
) {
6564 raw_spin_lock_irq(&child_ctx
->lock
);
6565 perf_group_detach(child_event
);
6566 raw_spin_unlock_irq(&child_ctx
->lock
);
6569 perf_remove_from_context(child_event
);
6572 * It can happen that the parent exits first, and has events
6573 * that are still around due to the child reference. These
6574 * events need to be zapped.
6576 if (child_event
->parent
) {
6577 sync_child_event(child_event
, child
);
6578 free_event(child_event
);
6582 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6584 struct perf_event
*child_event
, *tmp
;
6585 struct perf_event_context
*child_ctx
;
6586 unsigned long flags
;
6588 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6589 perf_event_task(child
, NULL
, 0);
6593 local_irq_save(flags
);
6595 * We can't reschedule here because interrupts are disabled,
6596 * and either child is current or it is a task that can't be
6597 * scheduled, so we are now safe from rescheduling changing
6600 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6603 * Take the context lock here so that if find_get_context is
6604 * reading child->perf_event_ctxp, we wait until it has
6605 * incremented the context's refcount before we do put_ctx below.
6607 raw_spin_lock(&child_ctx
->lock
);
6608 task_ctx_sched_out(child_ctx
);
6609 child
->perf_event_ctxp
[ctxn
] = NULL
;
6611 * If this context is a clone; unclone it so it can't get
6612 * swapped to another process while we're removing all
6613 * the events from it.
6615 unclone_ctx(child_ctx
);
6616 update_context_time(child_ctx
);
6617 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6620 * Report the task dead after unscheduling the events so that we
6621 * won't get any samples after PERF_RECORD_EXIT. We can however still
6622 * get a few PERF_RECORD_READ events.
6624 perf_event_task(child
, child_ctx
, 0);
6627 * We can recurse on the same lock type through:
6629 * __perf_event_exit_task()
6630 * sync_child_event()
6631 * fput(parent_event->filp)
6633 * mutex_lock(&ctx->mutex)
6635 * But since its the parent context it won't be the same instance.
6637 mutex_lock(&child_ctx
->mutex
);
6640 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6642 __perf_event_exit_task(child_event
, child_ctx
, child
);
6644 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6646 __perf_event_exit_task(child_event
, child_ctx
, child
);
6649 * If the last event was a group event, it will have appended all
6650 * its siblings to the list, but we obtained 'tmp' before that which
6651 * will still point to the list head terminating the iteration.
6653 if (!list_empty(&child_ctx
->pinned_groups
) ||
6654 !list_empty(&child_ctx
->flexible_groups
))
6657 mutex_unlock(&child_ctx
->mutex
);
6663 * When a child task exits, feed back event values to parent events.
6665 void perf_event_exit_task(struct task_struct
*child
)
6667 struct perf_event
*event
, *tmp
;
6670 mutex_lock(&child
->perf_event_mutex
);
6671 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6673 list_del_init(&event
->owner_entry
);
6676 * Ensure the list deletion is visible before we clear
6677 * the owner, closes a race against perf_release() where
6678 * we need to serialize on the owner->perf_event_mutex.
6681 event
->owner
= NULL
;
6683 mutex_unlock(&child
->perf_event_mutex
);
6685 for_each_task_context_nr(ctxn
)
6686 perf_event_exit_task_context(child
, ctxn
);
6689 static void perf_free_event(struct perf_event
*event
,
6690 struct perf_event_context
*ctx
)
6692 struct perf_event
*parent
= event
->parent
;
6694 if (WARN_ON_ONCE(!parent
))
6697 mutex_lock(&parent
->child_mutex
);
6698 list_del_init(&event
->child_list
);
6699 mutex_unlock(&parent
->child_mutex
);
6703 perf_group_detach(event
);
6704 list_del_event(event
, ctx
);
6709 * free an unexposed, unused context as created by inheritance by
6710 * perf_event_init_task below, used by fork() in case of fail.
6712 void perf_event_free_task(struct task_struct
*task
)
6714 struct perf_event_context
*ctx
;
6715 struct perf_event
*event
, *tmp
;
6718 for_each_task_context_nr(ctxn
) {
6719 ctx
= task
->perf_event_ctxp
[ctxn
];
6723 mutex_lock(&ctx
->mutex
);
6725 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6727 perf_free_event(event
, ctx
);
6729 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6731 perf_free_event(event
, ctx
);
6733 if (!list_empty(&ctx
->pinned_groups
) ||
6734 !list_empty(&ctx
->flexible_groups
))
6737 mutex_unlock(&ctx
->mutex
);
6743 void perf_event_delayed_put(struct task_struct
*task
)
6747 for_each_task_context_nr(ctxn
)
6748 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6752 * inherit a event from parent task to child task:
6754 static struct perf_event
*
6755 inherit_event(struct perf_event
*parent_event
,
6756 struct task_struct
*parent
,
6757 struct perf_event_context
*parent_ctx
,
6758 struct task_struct
*child
,
6759 struct perf_event
*group_leader
,
6760 struct perf_event_context
*child_ctx
)
6762 struct perf_event
*child_event
;
6763 unsigned long flags
;
6766 * Instead of creating recursive hierarchies of events,
6767 * we link inherited events back to the original parent,
6768 * which has a filp for sure, which we use as the reference
6771 if (parent_event
->parent
)
6772 parent_event
= parent_event
->parent
;
6774 child_event
= perf_event_alloc(&parent_event
->attr
,
6777 group_leader
, parent_event
,
6779 if (IS_ERR(child_event
))
6784 * Make the child state follow the state of the parent event,
6785 * not its attr.disabled bit. We hold the parent's mutex,
6786 * so we won't race with perf_event_{en, dis}able_family.
6788 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6789 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6791 child_event
->state
= PERF_EVENT_STATE_OFF
;
6793 if (parent_event
->attr
.freq
) {
6794 u64 sample_period
= parent_event
->hw
.sample_period
;
6795 struct hw_perf_event
*hwc
= &child_event
->hw
;
6797 hwc
->sample_period
= sample_period
;
6798 hwc
->last_period
= sample_period
;
6800 local64_set(&hwc
->period_left
, sample_period
);
6803 child_event
->ctx
= child_ctx
;
6804 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6805 child_event
->overflow_handler_context
6806 = parent_event
->overflow_handler_context
;
6809 * Precalculate sample_data sizes
6811 perf_event__header_size(child_event
);
6812 perf_event__id_header_size(child_event
);
6815 * Link it up in the child's context:
6817 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6818 add_event_to_ctx(child_event
, child_ctx
);
6819 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6822 * Get a reference to the parent filp - we will fput it
6823 * when the child event exits. This is safe to do because
6824 * we are in the parent and we know that the filp still
6825 * exists and has a nonzero count:
6827 atomic_long_inc(&parent_event
->filp
->f_count
);
6830 * Link this into the parent event's child list
6832 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6833 mutex_lock(&parent_event
->child_mutex
);
6834 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
6835 mutex_unlock(&parent_event
->child_mutex
);
6840 static int inherit_group(struct perf_event
*parent_event
,
6841 struct task_struct
*parent
,
6842 struct perf_event_context
*parent_ctx
,
6843 struct task_struct
*child
,
6844 struct perf_event_context
*child_ctx
)
6846 struct perf_event
*leader
;
6847 struct perf_event
*sub
;
6848 struct perf_event
*child_ctr
;
6850 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
6851 child
, NULL
, child_ctx
);
6853 return PTR_ERR(leader
);
6854 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
6855 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
6856 child
, leader
, child_ctx
);
6857 if (IS_ERR(child_ctr
))
6858 return PTR_ERR(child_ctr
);
6864 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
6865 struct perf_event_context
*parent_ctx
,
6866 struct task_struct
*child
, int ctxn
,
6870 struct perf_event_context
*child_ctx
;
6872 if (!event
->attr
.inherit
) {
6877 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6880 * This is executed from the parent task context, so
6881 * inherit events that have been marked for cloning.
6882 * First allocate and initialize a context for the
6886 child_ctx
= alloc_perf_context(event
->pmu
, child
);
6890 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
6893 ret
= inherit_group(event
, parent
, parent_ctx
,
6903 * Initialize the perf_event context in task_struct
6905 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
6907 struct perf_event_context
*child_ctx
, *parent_ctx
;
6908 struct perf_event_context
*cloned_ctx
;
6909 struct perf_event
*event
;
6910 struct task_struct
*parent
= current
;
6911 int inherited_all
= 1;
6912 unsigned long flags
;
6915 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
6919 * If the parent's context is a clone, pin it so it won't get
6922 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
6925 * No need to check if parent_ctx != NULL here; since we saw
6926 * it non-NULL earlier, the only reason for it to become NULL
6927 * is if we exit, and since we're currently in the middle of
6928 * a fork we can't be exiting at the same time.
6932 * Lock the parent list. No need to lock the child - not PID
6933 * hashed yet and not running, so nobody can access it.
6935 mutex_lock(&parent_ctx
->mutex
);
6938 * We dont have to disable NMIs - we are only looking at
6939 * the list, not manipulating it:
6941 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
6942 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6943 child
, ctxn
, &inherited_all
);
6949 * We can't hold ctx->lock when iterating the ->flexible_group list due
6950 * to allocations, but we need to prevent rotation because
6951 * rotate_ctx() will change the list from interrupt context.
6953 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6954 parent_ctx
->rotate_disable
= 1;
6955 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6957 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
6958 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6959 child
, ctxn
, &inherited_all
);
6964 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6965 parent_ctx
->rotate_disable
= 0;
6967 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6969 if (child_ctx
&& inherited_all
) {
6971 * Mark the child context as a clone of the parent
6972 * context, or of whatever the parent is a clone of.
6974 * Note that if the parent is a clone, the holding of
6975 * parent_ctx->lock avoids it from being uncloned.
6977 cloned_ctx
= parent_ctx
->parent_ctx
;
6979 child_ctx
->parent_ctx
= cloned_ctx
;
6980 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
6982 child_ctx
->parent_ctx
= parent_ctx
;
6983 child_ctx
->parent_gen
= parent_ctx
->generation
;
6985 get_ctx(child_ctx
->parent_ctx
);
6988 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6989 mutex_unlock(&parent_ctx
->mutex
);
6991 perf_unpin_context(parent_ctx
);
6992 put_ctx(parent_ctx
);
6998 * Initialize the perf_event context in task_struct
7000 int perf_event_init_task(struct task_struct
*child
)
7004 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7005 mutex_init(&child
->perf_event_mutex
);
7006 INIT_LIST_HEAD(&child
->perf_event_list
);
7008 for_each_task_context_nr(ctxn
) {
7009 ret
= perf_event_init_context(child
, ctxn
);
7017 static void __init
perf_event_init_all_cpus(void)
7019 struct swevent_htable
*swhash
;
7022 for_each_possible_cpu(cpu
) {
7023 swhash
= &per_cpu(swevent_htable
, cpu
);
7024 mutex_init(&swhash
->hlist_mutex
);
7025 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7029 static void __cpuinit
perf_event_init_cpu(int cpu
)
7031 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7033 mutex_lock(&swhash
->hlist_mutex
);
7034 if (swhash
->hlist_refcount
> 0) {
7035 struct swevent_hlist
*hlist
;
7037 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7039 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7041 mutex_unlock(&swhash
->hlist_mutex
);
7044 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7045 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7047 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7049 WARN_ON(!irqs_disabled());
7051 list_del_init(&cpuctx
->rotation_list
);
7054 static void __perf_event_exit_context(void *__info
)
7056 struct perf_event_context
*ctx
= __info
;
7057 struct perf_event
*event
, *tmp
;
7059 perf_pmu_rotate_stop(ctx
->pmu
);
7061 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
7062 __perf_remove_from_context(event
);
7063 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
7064 __perf_remove_from_context(event
);
7067 static void perf_event_exit_cpu_context(int cpu
)
7069 struct perf_event_context
*ctx
;
7073 idx
= srcu_read_lock(&pmus_srcu
);
7074 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7075 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
7077 mutex_lock(&ctx
->mutex
);
7078 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
7079 mutex_unlock(&ctx
->mutex
);
7081 srcu_read_unlock(&pmus_srcu
, idx
);
7084 static void perf_event_exit_cpu(int cpu
)
7086 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7088 mutex_lock(&swhash
->hlist_mutex
);
7089 swevent_hlist_release(swhash
);
7090 mutex_unlock(&swhash
->hlist_mutex
);
7092 perf_event_exit_cpu_context(cpu
);
7095 static inline void perf_event_exit_cpu(int cpu
) { }
7099 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
7103 for_each_online_cpu(cpu
)
7104 perf_event_exit_cpu(cpu
);
7110 * Run the perf reboot notifier at the very last possible moment so that
7111 * the generic watchdog code runs as long as possible.
7113 static struct notifier_block perf_reboot_notifier
= {
7114 .notifier_call
= perf_reboot
,
7115 .priority
= INT_MIN
,
7118 static int __cpuinit
7119 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
7121 unsigned int cpu
= (long)hcpu
;
7123 switch (action
& ~CPU_TASKS_FROZEN
) {
7125 case CPU_UP_PREPARE
:
7126 case CPU_DOWN_FAILED
:
7127 perf_event_init_cpu(cpu
);
7130 case CPU_UP_CANCELED
:
7131 case CPU_DOWN_PREPARE
:
7132 perf_event_exit_cpu(cpu
);
7142 void __init
perf_event_init(void)
7148 perf_event_init_all_cpus();
7149 init_srcu_struct(&pmus_srcu
);
7150 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
7151 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
7152 perf_pmu_register(&perf_task_clock
, NULL
, -1);
7154 perf_cpu_notifier(perf_cpu_notify
);
7155 register_reboot_notifier(&perf_reboot_notifier
);
7157 ret
= init_hw_breakpoint();
7158 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
7160 /* do not patch jump label more than once per second */
7161 jump_label_rate_limit(&perf_sched_events
, HZ
);
7164 * Build time assertion that we keep the data_head at the intended
7165 * location. IOW, validation we got the __reserved[] size right.
7167 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
7171 static int __init
perf_event_sysfs_init(void)
7176 mutex_lock(&pmus_lock
);
7178 ret
= bus_register(&pmu_bus
);
7182 list_for_each_entry(pmu
, &pmus
, entry
) {
7183 if (!pmu
->name
|| pmu
->type
< 0)
7186 ret
= pmu_dev_alloc(pmu
);
7187 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
7189 pmu_bus_running
= 1;
7193 mutex_unlock(&pmus_lock
);
7197 device_initcall(perf_event_sysfs_init
);
7199 #ifdef CONFIG_CGROUP_PERF
7200 static struct cgroup_subsys_state
*perf_cgroup_create(struct cgroup
*cont
)
7202 struct perf_cgroup
*jc
;
7204 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
7206 return ERR_PTR(-ENOMEM
);
7208 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
7211 return ERR_PTR(-ENOMEM
);
7217 static void perf_cgroup_destroy(struct cgroup
*cont
)
7219 struct perf_cgroup
*jc
;
7220 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
7221 struct perf_cgroup
, css
);
7222 free_percpu(jc
->info
);
7226 static int __perf_cgroup_move(void *info
)
7228 struct task_struct
*task
= info
;
7229 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
7233 static void perf_cgroup_attach(struct cgroup
*cgrp
, struct cgroup_taskset
*tset
)
7235 struct task_struct
*task
;
7237 cgroup_taskset_for_each(task
, cgrp
, tset
)
7238 task_function_call(task
, __perf_cgroup_move
, task
);
7241 static void perf_cgroup_exit(struct cgroup
*cgrp
, struct cgroup
*old_cgrp
,
7242 struct task_struct
*task
)
7245 * cgroup_exit() is called in the copy_process() failure path.
7246 * Ignore this case since the task hasn't ran yet, this avoids
7247 * trying to poke a half freed task state from generic code.
7249 if (!(task
->flags
& PF_EXITING
))
7252 task_function_call(task
, __perf_cgroup_move
, task
);
7255 struct cgroup_subsys perf_subsys
= {
7256 .name
= "perf_event",
7257 .subsys_id
= perf_subsys_id
,
7258 .create
= perf_cgroup_create
,
7259 .destroy
= perf_cgroup_destroy
,
7260 .exit
= perf_cgroup_exit
,
7261 .attach
= perf_cgroup_attach
,
7263 #endif /* CONFIG_CGROUP_PERF */