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>
39 #include <linux/mm_types.h>
43 #include <asm/irq_regs.h>
45 struct remote_function_call
{
46 struct task_struct
*p
;
47 int (*func
)(void *info
);
52 static void remote_function(void *data
)
54 struct remote_function_call
*tfc
= data
;
55 struct task_struct
*p
= tfc
->p
;
59 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
63 tfc
->ret
= tfc
->func(tfc
->info
);
67 * task_function_call - call a function on the cpu on which a task runs
68 * @p: the task to evaluate
69 * @func: the function to be called
70 * @info: the function call argument
72 * Calls the function @func when the task is currently running. This might
73 * be on the current CPU, which just calls the function directly
75 * returns: @func return value, or
76 * -ESRCH - when the process isn't running
77 * -EAGAIN - when the process moved away
80 task_function_call(struct task_struct
*p
, int (*func
) (void *info
), void *info
)
82 struct remote_function_call data
= {
86 .ret
= -ESRCH
, /* No such (running) process */
90 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
96 * cpu_function_call - call a function on the cpu
97 * @func: the function to be called
98 * @info: the function call argument
100 * Calls the function @func on the remote cpu.
102 * returns: @func return value or -ENXIO when the cpu is offline
104 static int cpu_function_call(int cpu
, int (*func
) (void *info
), void *info
)
106 struct remote_function_call data
= {
110 .ret
= -ENXIO
, /* No such CPU */
113 smp_call_function_single(cpu
, remote_function
, &data
, 1);
118 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
119 PERF_FLAG_FD_OUTPUT |\
120 PERF_FLAG_PID_CGROUP)
123 * branch priv levels that need permission checks
125 #define PERF_SAMPLE_BRANCH_PERM_PLM \
126 (PERF_SAMPLE_BRANCH_KERNEL |\
127 PERF_SAMPLE_BRANCH_HV)
130 EVENT_FLEXIBLE
= 0x1,
132 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
136 * perf_sched_events : >0 events exist
137 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
139 struct static_key_deferred perf_sched_events __read_mostly
;
140 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
141 static DEFINE_PER_CPU(atomic_t
, perf_branch_stack_events
);
143 static atomic_t nr_mmap_events __read_mostly
;
144 static atomic_t nr_comm_events __read_mostly
;
145 static atomic_t nr_task_events __read_mostly
;
147 static LIST_HEAD(pmus
);
148 static DEFINE_MUTEX(pmus_lock
);
149 static struct srcu_struct pmus_srcu
;
152 * perf event paranoia level:
153 * -1 - not paranoid at all
154 * 0 - disallow raw tracepoint access for unpriv
155 * 1 - disallow cpu events for unpriv
156 * 2 - disallow kernel profiling for unpriv
158 int sysctl_perf_event_paranoid __read_mostly
= 1;
160 /* Minimum for 512 kiB + 1 user control page */
161 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
164 * max perf event sample rate
166 #define DEFAULT_MAX_SAMPLE_RATE 100000
167 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
168 static int max_samples_per_tick __read_mostly
=
169 DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
171 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
172 void __user
*buffer
, size_t *lenp
,
175 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
180 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
185 static atomic64_t perf_event_id
;
187 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
188 enum event_type_t event_type
);
190 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
191 enum event_type_t event_type
,
192 struct task_struct
*task
);
194 static void update_context_time(struct perf_event_context
*ctx
);
195 static u64
perf_event_time(struct perf_event
*event
);
197 static void ring_buffer_attach(struct perf_event
*event
,
198 struct ring_buffer
*rb
);
200 void __weak
perf_event_print_debug(void) { }
202 extern __weak
const char *perf_pmu_name(void)
207 static inline u64
perf_clock(void)
209 return local_clock();
212 static inline struct perf_cpu_context
*
213 __get_cpu_context(struct perf_event_context
*ctx
)
215 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
218 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
219 struct perf_event_context
*ctx
)
221 raw_spin_lock(&cpuctx
->ctx
.lock
);
223 raw_spin_lock(&ctx
->lock
);
226 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
227 struct perf_event_context
*ctx
)
230 raw_spin_unlock(&ctx
->lock
);
231 raw_spin_unlock(&cpuctx
->ctx
.lock
);
234 #ifdef CONFIG_CGROUP_PERF
237 * Must ensure cgroup is pinned (css_get) before calling
238 * this function. In other words, we cannot call this function
239 * if there is no cgroup event for the current CPU context.
241 static inline struct perf_cgroup
*
242 perf_cgroup_from_task(struct task_struct
*task
)
244 return container_of(task_subsys_state(task
, perf_subsys_id
),
245 struct perf_cgroup
, css
);
249 perf_cgroup_match(struct perf_event
*event
)
251 struct perf_event_context
*ctx
= event
->ctx
;
252 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
254 /* @event doesn't care about cgroup */
258 /* wants specific cgroup scope but @cpuctx isn't associated with any */
263 * Cgroup scoping is recursive. An event enabled for a cgroup is
264 * also enabled for all its descendant cgroups. If @cpuctx's
265 * cgroup is a descendant of @event's (the test covers identity
266 * case), it's a match.
268 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
269 event
->cgrp
->css
.cgroup
);
272 static inline bool perf_tryget_cgroup(struct perf_event
*event
)
274 return css_tryget(&event
->cgrp
->css
);
277 static inline void perf_put_cgroup(struct perf_event
*event
)
279 css_put(&event
->cgrp
->css
);
282 static inline void perf_detach_cgroup(struct perf_event
*event
)
284 perf_put_cgroup(event
);
288 static inline int is_cgroup_event(struct perf_event
*event
)
290 return event
->cgrp
!= NULL
;
293 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
295 struct perf_cgroup_info
*t
;
297 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
301 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
303 struct perf_cgroup_info
*info
;
308 info
= this_cpu_ptr(cgrp
->info
);
310 info
->time
+= now
- info
->timestamp
;
311 info
->timestamp
= now
;
314 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
316 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
318 __update_cgrp_time(cgrp_out
);
321 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
323 struct perf_cgroup
*cgrp
;
326 * ensure we access cgroup data only when needed and
327 * when we know the cgroup is pinned (css_get)
329 if (!is_cgroup_event(event
))
332 cgrp
= perf_cgroup_from_task(current
);
334 * Do not update time when cgroup is not active
336 if (cgrp
== event
->cgrp
)
337 __update_cgrp_time(event
->cgrp
);
341 perf_cgroup_set_timestamp(struct task_struct
*task
,
342 struct perf_event_context
*ctx
)
344 struct perf_cgroup
*cgrp
;
345 struct perf_cgroup_info
*info
;
348 * ctx->lock held by caller
349 * ensure we do not access cgroup data
350 * unless we have the cgroup pinned (css_get)
352 if (!task
|| !ctx
->nr_cgroups
)
355 cgrp
= perf_cgroup_from_task(task
);
356 info
= this_cpu_ptr(cgrp
->info
);
357 info
->timestamp
= ctx
->timestamp
;
360 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
361 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
364 * reschedule events based on the cgroup constraint of task.
366 * mode SWOUT : schedule out everything
367 * mode SWIN : schedule in based on cgroup for next
369 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
371 struct perf_cpu_context
*cpuctx
;
376 * disable interrupts to avoid geting nr_cgroup
377 * changes via __perf_event_disable(). Also
380 local_irq_save(flags
);
383 * we reschedule only in the presence of cgroup
384 * constrained events.
388 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
389 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
390 if (cpuctx
->unique_pmu
!= pmu
)
391 continue; /* ensure we process each cpuctx once */
394 * perf_cgroup_events says at least one
395 * context on this CPU has cgroup events.
397 * ctx->nr_cgroups reports the number of cgroup
398 * events for a context.
400 if (cpuctx
->ctx
.nr_cgroups
> 0) {
401 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
402 perf_pmu_disable(cpuctx
->ctx
.pmu
);
404 if (mode
& PERF_CGROUP_SWOUT
) {
405 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
407 * must not be done before ctxswout due
408 * to event_filter_match() in event_sched_out()
413 if (mode
& PERF_CGROUP_SWIN
) {
414 WARN_ON_ONCE(cpuctx
->cgrp
);
416 * set cgrp before ctxsw in to allow
417 * event_filter_match() to not have to pass
420 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
421 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
423 perf_pmu_enable(cpuctx
->ctx
.pmu
);
424 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
430 local_irq_restore(flags
);
433 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
434 struct task_struct
*next
)
436 struct perf_cgroup
*cgrp1
;
437 struct perf_cgroup
*cgrp2
= NULL
;
440 * we come here when we know perf_cgroup_events > 0
442 cgrp1
= perf_cgroup_from_task(task
);
445 * next is NULL when called from perf_event_enable_on_exec()
446 * that will systematically cause a cgroup_switch()
449 cgrp2
= perf_cgroup_from_task(next
);
452 * only schedule out current cgroup events if we know
453 * that we are switching to a different cgroup. Otherwise,
454 * do no touch the cgroup events.
457 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
460 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
461 struct task_struct
*task
)
463 struct perf_cgroup
*cgrp1
;
464 struct perf_cgroup
*cgrp2
= NULL
;
467 * we come here when we know perf_cgroup_events > 0
469 cgrp1
= perf_cgroup_from_task(task
);
471 /* prev can never be NULL */
472 cgrp2
= perf_cgroup_from_task(prev
);
475 * only need to schedule in cgroup events if we are changing
476 * cgroup during ctxsw. Cgroup events were not scheduled
477 * out of ctxsw out if that was not the case.
480 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
483 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
484 struct perf_event_attr
*attr
,
485 struct perf_event
*group_leader
)
487 struct perf_cgroup
*cgrp
;
488 struct cgroup_subsys_state
*css
;
489 struct fd f
= fdget(fd
);
495 css
= cgroup_css_from_dir(f
.file
, perf_subsys_id
);
501 cgrp
= container_of(css
, struct perf_cgroup
, css
);
504 /* must be done before we fput() the file */
505 if (!perf_tryget_cgroup(event
)) {
512 * all events in a group must monitor
513 * the same cgroup because a task belongs
514 * to only one perf cgroup at a time
516 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
517 perf_detach_cgroup(event
);
526 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
528 struct perf_cgroup_info
*t
;
529 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
530 event
->shadow_ctx_time
= now
- t
->timestamp
;
534 perf_cgroup_defer_enabled(struct perf_event
*event
)
537 * when the current task's perf cgroup does not match
538 * the event's, we need to remember to call the
539 * perf_mark_enable() function the first time a task with
540 * a matching perf cgroup is scheduled in.
542 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
543 event
->cgrp_defer_enabled
= 1;
547 perf_cgroup_mark_enabled(struct perf_event
*event
,
548 struct perf_event_context
*ctx
)
550 struct perf_event
*sub
;
551 u64 tstamp
= perf_event_time(event
);
553 if (!event
->cgrp_defer_enabled
)
556 event
->cgrp_defer_enabled
= 0;
558 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
559 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
560 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
561 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
562 sub
->cgrp_defer_enabled
= 0;
566 #else /* !CONFIG_CGROUP_PERF */
569 perf_cgroup_match(struct perf_event
*event
)
574 static inline void perf_detach_cgroup(struct perf_event
*event
)
577 static inline int is_cgroup_event(struct perf_event
*event
)
582 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
587 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
591 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
595 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
596 struct task_struct
*next
)
600 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
601 struct task_struct
*task
)
605 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
606 struct perf_event_attr
*attr
,
607 struct perf_event
*group_leader
)
613 perf_cgroup_set_timestamp(struct task_struct
*task
,
614 struct perf_event_context
*ctx
)
619 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
624 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
628 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
634 perf_cgroup_defer_enabled(struct perf_event
*event
)
639 perf_cgroup_mark_enabled(struct perf_event
*event
,
640 struct perf_event_context
*ctx
)
645 void perf_pmu_disable(struct pmu
*pmu
)
647 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
649 pmu
->pmu_disable(pmu
);
652 void perf_pmu_enable(struct pmu
*pmu
)
654 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
656 pmu
->pmu_enable(pmu
);
659 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
662 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
663 * because they're strictly cpu affine and rotate_start is called with IRQs
664 * disabled, while rotate_context is called from IRQ context.
666 static void perf_pmu_rotate_start(struct pmu
*pmu
)
668 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
669 struct list_head
*head
= &__get_cpu_var(rotation_list
);
671 WARN_ON(!irqs_disabled());
673 if (list_empty(&cpuctx
->rotation_list
))
674 list_add(&cpuctx
->rotation_list
, head
);
677 static void get_ctx(struct perf_event_context
*ctx
)
679 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
682 static void put_ctx(struct perf_event_context
*ctx
)
684 if (atomic_dec_and_test(&ctx
->refcount
)) {
686 put_ctx(ctx
->parent_ctx
);
688 put_task_struct(ctx
->task
);
689 kfree_rcu(ctx
, rcu_head
);
693 static void unclone_ctx(struct perf_event_context
*ctx
)
695 if (ctx
->parent_ctx
) {
696 put_ctx(ctx
->parent_ctx
);
697 ctx
->parent_ctx
= NULL
;
701 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
704 * only top level events have the pid namespace they were created in
707 event
= event
->parent
;
709 return task_tgid_nr_ns(p
, event
->ns
);
712 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
715 * only top level events have the pid namespace they were created in
718 event
= event
->parent
;
720 return task_pid_nr_ns(p
, event
->ns
);
724 * If we inherit events we want to return the parent event id
727 static u64
primary_event_id(struct perf_event
*event
)
732 id
= event
->parent
->id
;
738 * Get the perf_event_context for a task and lock it.
739 * This has to cope with with the fact that until it is locked,
740 * the context could get moved to another task.
742 static struct perf_event_context
*
743 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
745 struct perf_event_context
*ctx
;
749 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
752 * If this context is a clone of another, it might
753 * get swapped for another underneath us by
754 * perf_event_task_sched_out, though the
755 * rcu_read_lock() protects us from any context
756 * getting freed. Lock the context and check if it
757 * got swapped before we could get the lock, and retry
758 * if so. If we locked the right context, then it
759 * can't get swapped on us any more.
761 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
762 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
763 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
767 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
768 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
777 * Get the context for a task and increment its pin_count so it
778 * can't get swapped to another task. This also increments its
779 * reference count so that the context can't get freed.
781 static struct perf_event_context
*
782 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
784 struct perf_event_context
*ctx
;
787 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
790 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
795 static void perf_unpin_context(struct perf_event_context
*ctx
)
799 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
801 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
805 * Update the record of the current time in a context.
807 static void update_context_time(struct perf_event_context
*ctx
)
809 u64 now
= perf_clock();
811 ctx
->time
+= now
- ctx
->timestamp
;
812 ctx
->timestamp
= now
;
815 static u64
perf_event_time(struct perf_event
*event
)
817 struct perf_event_context
*ctx
= event
->ctx
;
819 if (is_cgroup_event(event
))
820 return perf_cgroup_event_time(event
);
822 return ctx
? ctx
->time
: 0;
826 * Update the total_time_enabled and total_time_running fields for a event.
827 * The caller of this function needs to hold the ctx->lock.
829 static void update_event_times(struct perf_event
*event
)
831 struct perf_event_context
*ctx
= event
->ctx
;
834 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
835 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
838 * in cgroup mode, time_enabled represents
839 * the time the event was enabled AND active
840 * tasks were in the monitored cgroup. This is
841 * independent of the activity of the context as
842 * there may be a mix of cgroup and non-cgroup events.
844 * That is why we treat cgroup events differently
847 if (is_cgroup_event(event
))
848 run_end
= perf_cgroup_event_time(event
);
849 else if (ctx
->is_active
)
852 run_end
= event
->tstamp_stopped
;
854 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
856 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
857 run_end
= event
->tstamp_stopped
;
859 run_end
= perf_event_time(event
);
861 event
->total_time_running
= run_end
- event
->tstamp_running
;
866 * Update total_time_enabled and total_time_running for all events in a group.
868 static void update_group_times(struct perf_event
*leader
)
870 struct perf_event
*event
;
872 update_event_times(leader
);
873 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
874 update_event_times(event
);
877 static struct list_head
*
878 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
880 if (event
->attr
.pinned
)
881 return &ctx
->pinned_groups
;
883 return &ctx
->flexible_groups
;
887 * Add a event from the lists for its context.
888 * Must be called with ctx->mutex and ctx->lock held.
891 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
893 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
894 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
897 * If we're a stand alone event or group leader, we go to the context
898 * list, group events are kept attached to the group so that
899 * perf_group_detach can, at all times, locate all siblings.
901 if (event
->group_leader
== event
) {
902 struct list_head
*list
;
904 if (is_software_event(event
))
905 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
907 list
= ctx_group_list(event
, ctx
);
908 list_add_tail(&event
->group_entry
, list
);
911 if (is_cgroup_event(event
))
914 if (has_branch_stack(event
))
915 ctx
->nr_branch_stack
++;
917 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
919 perf_pmu_rotate_start(ctx
->pmu
);
921 if (event
->attr
.inherit_stat
)
926 * Initialize event state based on the perf_event_attr::disabled.
928 static inline void perf_event__state_init(struct perf_event
*event
)
930 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
931 PERF_EVENT_STATE_INACTIVE
;
935 * Called at perf_event creation and when events are attached/detached from a
938 static void perf_event__read_size(struct perf_event
*event
)
940 int entry
= sizeof(u64
); /* value */
944 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
947 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
950 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
951 entry
+= sizeof(u64
);
953 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
954 nr
+= event
->group_leader
->nr_siblings
;
959 event
->read_size
= size
;
962 static void perf_event__header_size(struct perf_event
*event
)
964 struct perf_sample_data
*data
;
965 u64 sample_type
= event
->attr
.sample_type
;
968 perf_event__read_size(event
);
970 if (sample_type
& PERF_SAMPLE_IP
)
971 size
+= sizeof(data
->ip
);
973 if (sample_type
& PERF_SAMPLE_ADDR
)
974 size
+= sizeof(data
->addr
);
976 if (sample_type
& PERF_SAMPLE_PERIOD
)
977 size
+= sizeof(data
->period
);
979 if (sample_type
& PERF_SAMPLE_READ
)
980 size
+= event
->read_size
;
982 event
->header_size
= size
;
985 static void perf_event__id_header_size(struct perf_event
*event
)
987 struct perf_sample_data
*data
;
988 u64 sample_type
= event
->attr
.sample_type
;
991 if (sample_type
& PERF_SAMPLE_TID
)
992 size
+= sizeof(data
->tid_entry
);
994 if (sample_type
& PERF_SAMPLE_TIME
)
995 size
+= sizeof(data
->time
);
997 if (sample_type
& PERF_SAMPLE_ID
)
998 size
+= sizeof(data
->id
);
1000 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1001 size
+= sizeof(data
->stream_id
);
1003 if (sample_type
& PERF_SAMPLE_CPU
)
1004 size
+= sizeof(data
->cpu_entry
);
1006 event
->id_header_size
= size
;
1009 static void perf_group_attach(struct perf_event
*event
)
1011 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1014 * We can have double attach due to group movement in perf_event_open.
1016 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1019 event
->attach_state
|= PERF_ATTACH_GROUP
;
1021 if (group_leader
== event
)
1024 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1025 !is_software_event(event
))
1026 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1028 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1029 group_leader
->nr_siblings
++;
1031 perf_event__header_size(group_leader
);
1033 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1034 perf_event__header_size(pos
);
1038 * Remove a event from the lists for its context.
1039 * Must be called with ctx->mutex and ctx->lock held.
1042 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1044 struct perf_cpu_context
*cpuctx
;
1046 * We can have double detach due to exit/hot-unplug + close.
1048 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1051 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1053 if (is_cgroup_event(event
)) {
1055 cpuctx
= __get_cpu_context(ctx
);
1057 * if there are no more cgroup events
1058 * then cler cgrp to avoid stale pointer
1059 * in update_cgrp_time_from_cpuctx()
1061 if (!ctx
->nr_cgroups
)
1062 cpuctx
->cgrp
= NULL
;
1065 if (has_branch_stack(event
))
1066 ctx
->nr_branch_stack
--;
1069 if (event
->attr
.inherit_stat
)
1072 list_del_rcu(&event
->event_entry
);
1074 if (event
->group_leader
== event
)
1075 list_del_init(&event
->group_entry
);
1077 update_group_times(event
);
1080 * If event was in error state, then keep it
1081 * that way, otherwise bogus counts will be
1082 * returned on read(). The only way to get out
1083 * of error state is by explicit re-enabling
1086 if (event
->state
> PERF_EVENT_STATE_OFF
)
1087 event
->state
= PERF_EVENT_STATE_OFF
;
1090 static void perf_group_detach(struct perf_event
*event
)
1092 struct perf_event
*sibling
, *tmp
;
1093 struct list_head
*list
= NULL
;
1096 * We can have double detach due to exit/hot-unplug + close.
1098 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1101 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1104 * If this is a sibling, remove it from its group.
1106 if (event
->group_leader
!= event
) {
1107 list_del_init(&event
->group_entry
);
1108 event
->group_leader
->nr_siblings
--;
1112 if (!list_empty(&event
->group_entry
))
1113 list
= &event
->group_entry
;
1116 * If this was a group event with sibling events then
1117 * upgrade the siblings to singleton events by adding them
1118 * to whatever list we are on.
1120 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1122 list_move_tail(&sibling
->group_entry
, list
);
1123 sibling
->group_leader
= sibling
;
1125 /* Inherit group flags from the previous leader */
1126 sibling
->group_flags
= event
->group_flags
;
1130 perf_event__header_size(event
->group_leader
);
1132 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1133 perf_event__header_size(tmp
);
1137 event_filter_match(struct perf_event
*event
)
1139 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1140 && perf_cgroup_match(event
);
1144 event_sched_out(struct perf_event
*event
,
1145 struct perf_cpu_context
*cpuctx
,
1146 struct perf_event_context
*ctx
)
1148 u64 tstamp
= perf_event_time(event
);
1151 * An event which could not be activated because of
1152 * filter mismatch still needs to have its timings
1153 * maintained, otherwise bogus information is return
1154 * via read() for time_enabled, time_running:
1156 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1157 && !event_filter_match(event
)) {
1158 delta
= tstamp
- event
->tstamp_stopped
;
1159 event
->tstamp_running
+= delta
;
1160 event
->tstamp_stopped
= tstamp
;
1163 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1166 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1167 if (event
->pending_disable
) {
1168 event
->pending_disable
= 0;
1169 event
->state
= PERF_EVENT_STATE_OFF
;
1171 event
->tstamp_stopped
= tstamp
;
1172 event
->pmu
->del(event
, 0);
1175 if (!is_software_event(event
))
1176 cpuctx
->active_oncpu
--;
1178 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1180 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1181 cpuctx
->exclusive
= 0;
1185 group_sched_out(struct perf_event
*group_event
,
1186 struct perf_cpu_context
*cpuctx
,
1187 struct perf_event_context
*ctx
)
1189 struct perf_event
*event
;
1190 int state
= group_event
->state
;
1192 event_sched_out(group_event
, cpuctx
, ctx
);
1195 * Schedule out siblings (if any):
1197 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1198 event_sched_out(event
, cpuctx
, ctx
);
1200 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1201 cpuctx
->exclusive
= 0;
1205 * Cross CPU call to remove a performance event
1207 * We disable the event on the hardware level first. After that we
1208 * remove it from the context list.
1210 static int __perf_remove_from_context(void *info
)
1212 struct perf_event
*event
= info
;
1213 struct perf_event_context
*ctx
= event
->ctx
;
1214 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1216 raw_spin_lock(&ctx
->lock
);
1217 event_sched_out(event
, cpuctx
, ctx
);
1218 list_del_event(event
, ctx
);
1219 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1221 cpuctx
->task_ctx
= NULL
;
1223 raw_spin_unlock(&ctx
->lock
);
1230 * Remove the event from a task's (or a CPU's) list of events.
1232 * CPU events are removed with a smp call. For task events we only
1233 * call when the task is on a CPU.
1235 * If event->ctx is a cloned context, callers must make sure that
1236 * every task struct that event->ctx->task could possibly point to
1237 * remains valid. This is OK when called from perf_release since
1238 * that only calls us on the top-level context, which can't be a clone.
1239 * When called from perf_event_exit_task, it's OK because the
1240 * context has been detached from its task.
1242 static void perf_remove_from_context(struct perf_event
*event
)
1244 struct perf_event_context
*ctx
= event
->ctx
;
1245 struct task_struct
*task
= ctx
->task
;
1247 lockdep_assert_held(&ctx
->mutex
);
1251 * Per cpu events are removed via an smp call and
1252 * the removal is always successful.
1254 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1259 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1262 raw_spin_lock_irq(&ctx
->lock
);
1264 * If we failed to find a running task, but find the context active now
1265 * that we've acquired the ctx->lock, retry.
1267 if (ctx
->is_active
) {
1268 raw_spin_unlock_irq(&ctx
->lock
);
1273 * Since the task isn't running, its safe to remove the event, us
1274 * holding the ctx->lock ensures the task won't get scheduled in.
1276 list_del_event(event
, ctx
);
1277 raw_spin_unlock_irq(&ctx
->lock
);
1281 * Cross CPU call to disable a performance event
1283 int __perf_event_disable(void *info
)
1285 struct perf_event
*event
= info
;
1286 struct perf_event_context
*ctx
= event
->ctx
;
1287 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1290 * If this is a per-task event, need to check whether this
1291 * event's task is the current task on this cpu.
1293 * Can trigger due to concurrent perf_event_context_sched_out()
1294 * flipping contexts around.
1296 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1299 raw_spin_lock(&ctx
->lock
);
1302 * If the event is on, turn it off.
1303 * If it is in error state, leave it in error state.
1305 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1306 update_context_time(ctx
);
1307 update_cgrp_time_from_event(event
);
1308 update_group_times(event
);
1309 if (event
== event
->group_leader
)
1310 group_sched_out(event
, cpuctx
, ctx
);
1312 event_sched_out(event
, cpuctx
, ctx
);
1313 event
->state
= PERF_EVENT_STATE_OFF
;
1316 raw_spin_unlock(&ctx
->lock
);
1324 * If event->ctx is a cloned context, callers must make sure that
1325 * every task struct that event->ctx->task could possibly point to
1326 * remains valid. This condition is satisifed when called through
1327 * perf_event_for_each_child or perf_event_for_each because they
1328 * hold the top-level event's child_mutex, so any descendant that
1329 * goes to exit will block in sync_child_event.
1330 * When called from perf_pending_event it's OK because event->ctx
1331 * is the current context on this CPU and preemption is disabled,
1332 * hence we can't get into perf_event_task_sched_out for this context.
1334 void perf_event_disable(struct perf_event
*event
)
1336 struct perf_event_context
*ctx
= event
->ctx
;
1337 struct task_struct
*task
= ctx
->task
;
1341 * Disable the event on the cpu that it's on
1343 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1348 if (!task_function_call(task
, __perf_event_disable
, event
))
1351 raw_spin_lock_irq(&ctx
->lock
);
1353 * If the event is still active, we need to retry the cross-call.
1355 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1356 raw_spin_unlock_irq(&ctx
->lock
);
1358 * Reload the task pointer, it might have been changed by
1359 * a concurrent perf_event_context_sched_out().
1366 * Since we have the lock this context can't be scheduled
1367 * in, so we can change the state safely.
1369 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1370 update_group_times(event
);
1371 event
->state
= PERF_EVENT_STATE_OFF
;
1373 raw_spin_unlock_irq(&ctx
->lock
);
1375 EXPORT_SYMBOL_GPL(perf_event_disable
);
1377 static void perf_set_shadow_time(struct perf_event
*event
,
1378 struct perf_event_context
*ctx
,
1382 * use the correct time source for the time snapshot
1384 * We could get by without this by leveraging the
1385 * fact that to get to this function, the caller
1386 * has most likely already called update_context_time()
1387 * and update_cgrp_time_xx() and thus both timestamp
1388 * are identical (or very close). Given that tstamp is,
1389 * already adjusted for cgroup, we could say that:
1390 * tstamp - ctx->timestamp
1392 * tstamp - cgrp->timestamp.
1394 * Then, in perf_output_read(), the calculation would
1395 * work with no changes because:
1396 * - event is guaranteed scheduled in
1397 * - no scheduled out in between
1398 * - thus the timestamp would be the same
1400 * But this is a bit hairy.
1402 * So instead, we have an explicit cgroup call to remain
1403 * within the time time source all along. We believe it
1404 * is cleaner and simpler to understand.
1406 if (is_cgroup_event(event
))
1407 perf_cgroup_set_shadow_time(event
, tstamp
);
1409 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1412 #define MAX_INTERRUPTS (~0ULL)
1414 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1417 event_sched_in(struct perf_event
*event
,
1418 struct perf_cpu_context
*cpuctx
,
1419 struct perf_event_context
*ctx
)
1421 u64 tstamp
= perf_event_time(event
);
1423 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1426 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1427 event
->oncpu
= smp_processor_id();
1430 * Unthrottle events, since we scheduled we might have missed several
1431 * ticks already, also for a heavily scheduling task there is little
1432 * guarantee it'll get a tick in a timely manner.
1434 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1435 perf_log_throttle(event
, 1);
1436 event
->hw
.interrupts
= 0;
1440 * The new state must be visible before we turn it on in the hardware:
1444 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1445 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1450 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1452 perf_set_shadow_time(event
, ctx
, tstamp
);
1454 if (!is_software_event(event
))
1455 cpuctx
->active_oncpu
++;
1457 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1460 if (event
->attr
.exclusive
)
1461 cpuctx
->exclusive
= 1;
1467 group_sched_in(struct perf_event
*group_event
,
1468 struct perf_cpu_context
*cpuctx
,
1469 struct perf_event_context
*ctx
)
1471 struct perf_event
*event
, *partial_group
= NULL
;
1472 struct pmu
*pmu
= group_event
->pmu
;
1473 u64 now
= ctx
->time
;
1474 bool simulate
= false;
1476 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1479 pmu
->start_txn(pmu
);
1481 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1482 pmu
->cancel_txn(pmu
);
1487 * Schedule in siblings as one group (if any):
1489 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1490 if (event_sched_in(event
, cpuctx
, ctx
)) {
1491 partial_group
= event
;
1496 if (!pmu
->commit_txn(pmu
))
1501 * Groups can be scheduled in as one unit only, so undo any
1502 * partial group before returning:
1503 * The events up to the failed event are scheduled out normally,
1504 * tstamp_stopped will be updated.
1506 * The failed events and the remaining siblings need to have
1507 * their timings updated as if they had gone thru event_sched_in()
1508 * and event_sched_out(). This is required to get consistent timings
1509 * across the group. This also takes care of the case where the group
1510 * could never be scheduled by ensuring tstamp_stopped is set to mark
1511 * the time the event was actually stopped, such that time delta
1512 * calculation in update_event_times() is correct.
1514 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1515 if (event
== partial_group
)
1519 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1520 event
->tstamp_stopped
= now
;
1522 event_sched_out(event
, cpuctx
, ctx
);
1525 event_sched_out(group_event
, cpuctx
, ctx
);
1527 pmu
->cancel_txn(pmu
);
1533 * Work out whether we can put this event group on the CPU now.
1535 static int group_can_go_on(struct perf_event
*event
,
1536 struct perf_cpu_context
*cpuctx
,
1540 * Groups consisting entirely of software events can always go on.
1542 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1545 * If an exclusive group is already on, no other hardware
1548 if (cpuctx
->exclusive
)
1551 * If this group is exclusive and there are already
1552 * events on the CPU, it can't go on.
1554 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1557 * Otherwise, try to add it if all previous groups were able
1563 static void add_event_to_ctx(struct perf_event
*event
,
1564 struct perf_event_context
*ctx
)
1566 u64 tstamp
= perf_event_time(event
);
1568 list_add_event(event
, ctx
);
1569 perf_group_attach(event
);
1570 event
->tstamp_enabled
= tstamp
;
1571 event
->tstamp_running
= tstamp
;
1572 event
->tstamp_stopped
= tstamp
;
1575 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
1577 ctx_sched_in(struct perf_event_context
*ctx
,
1578 struct perf_cpu_context
*cpuctx
,
1579 enum event_type_t event_type
,
1580 struct task_struct
*task
);
1582 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
1583 struct perf_event_context
*ctx
,
1584 struct task_struct
*task
)
1586 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
1588 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
1589 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
1591 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
1595 * Cross CPU call to install and enable a performance event
1597 * Must be called with ctx->mutex held
1599 static int __perf_install_in_context(void *info
)
1601 struct perf_event
*event
= info
;
1602 struct perf_event_context
*ctx
= event
->ctx
;
1603 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1604 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
1605 struct task_struct
*task
= current
;
1607 perf_ctx_lock(cpuctx
, task_ctx
);
1608 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1611 * If there was an active task_ctx schedule it out.
1614 task_ctx_sched_out(task_ctx
);
1617 * If the context we're installing events in is not the
1618 * active task_ctx, flip them.
1620 if (ctx
->task
&& task_ctx
!= ctx
) {
1622 raw_spin_unlock(&task_ctx
->lock
);
1623 raw_spin_lock(&ctx
->lock
);
1628 cpuctx
->task_ctx
= task_ctx
;
1629 task
= task_ctx
->task
;
1632 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
1634 update_context_time(ctx
);
1636 * update cgrp time only if current cgrp
1637 * matches event->cgrp. Must be done before
1638 * calling add_event_to_ctx()
1640 update_cgrp_time_from_event(event
);
1642 add_event_to_ctx(event
, ctx
);
1645 * Schedule everything back in
1647 perf_event_sched_in(cpuctx
, task_ctx
, task
);
1649 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1650 perf_ctx_unlock(cpuctx
, task_ctx
);
1656 * Attach a performance event to a context
1658 * First we add the event to the list with the hardware enable bit
1659 * in event->hw_config cleared.
1661 * If the event is attached to a task which is on a CPU we use a smp
1662 * call to enable it in the task context. The task might have been
1663 * scheduled away, but we check this in the smp call again.
1666 perf_install_in_context(struct perf_event_context
*ctx
,
1667 struct perf_event
*event
,
1670 struct task_struct
*task
= ctx
->task
;
1672 lockdep_assert_held(&ctx
->mutex
);
1675 if (event
->cpu
!= -1)
1680 * Per cpu events are installed via an smp call and
1681 * the install is always successful.
1683 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1688 if (!task_function_call(task
, __perf_install_in_context
, event
))
1691 raw_spin_lock_irq(&ctx
->lock
);
1693 * If we failed to find a running task, but find the context active now
1694 * that we've acquired the ctx->lock, retry.
1696 if (ctx
->is_active
) {
1697 raw_spin_unlock_irq(&ctx
->lock
);
1702 * Since the task isn't running, its safe to add the event, us holding
1703 * the ctx->lock ensures the task won't get scheduled in.
1705 add_event_to_ctx(event
, ctx
);
1706 raw_spin_unlock_irq(&ctx
->lock
);
1710 * Put a event into inactive state and update time fields.
1711 * Enabling the leader of a group effectively enables all
1712 * the group members that aren't explicitly disabled, so we
1713 * have to update their ->tstamp_enabled also.
1714 * Note: this works for group members as well as group leaders
1715 * since the non-leader members' sibling_lists will be empty.
1717 static void __perf_event_mark_enabled(struct perf_event
*event
)
1719 struct perf_event
*sub
;
1720 u64 tstamp
= perf_event_time(event
);
1722 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1723 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1724 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1725 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1726 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1731 * Cross CPU call to enable a performance event
1733 static int __perf_event_enable(void *info
)
1735 struct perf_event
*event
= info
;
1736 struct perf_event_context
*ctx
= event
->ctx
;
1737 struct perf_event
*leader
= event
->group_leader
;
1738 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1741 if (WARN_ON_ONCE(!ctx
->is_active
))
1744 raw_spin_lock(&ctx
->lock
);
1745 update_context_time(ctx
);
1747 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1751 * set current task's cgroup time reference point
1753 perf_cgroup_set_timestamp(current
, ctx
);
1755 __perf_event_mark_enabled(event
);
1757 if (!event_filter_match(event
)) {
1758 if (is_cgroup_event(event
))
1759 perf_cgroup_defer_enabled(event
);
1764 * If the event is in a group and isn't the group leader,
1765 * then don't put it on unless the group is on.
1767 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1770 if (!group_can_go_on(event
, cpuctx
, 1)) {
1773 if (event
== leader
)
1774 err
= group_sched_in(event
, cpuctx
, ctx
);
1776 err
= event_sched_in(event
, cpuctx
, ctx
);
1781 * If this event can't go on and it's part of a
1782 * group, then the whole group has to come off.
1784 if (leader
!= event
)
1785 group_sched_out(leader
, cpuctx
, ctx
);
1786 if (leader
->attr
.pinned
) {
1787 update_group_times(leader
);
1788 leader
->state
= PERF_EVENT_STATE_ERROR
;
1793 raw_spin_unlock(&ctx
->lock
);
1801 * If event->ctx is a cloned context, callers must make sure that
1802 * every task struct that event->ctx->task could possibly point to
1803 * remains valid. This condition is satisfied when called through
1804 * perf_event_for_each_child or perf_event_for_each as described
1805 * for perf_event_disable.
1807 void perf_event_enable(struct perf_event
*event
)
1809 struct perf_event_context
*ctx
= event
->ctx
;
1810 struct task_struct
*task
= ctx
->task
;
1814 * Enable the event on the cpu that it's on
1816 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
1820 raw_spin_lock_irq(&ctx
->lock
);
1821 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1825 * If the event is in error state, clear that first.
1826 * That way, if we see the event in error state below, we
1827 * know that it has gone back into error state, as distinct
1828 * from the task having been scheduled away before the
1829 * cross-call arrived.
1831 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1832 event
->state
= PERF_EVENT_STATE_OFF
;
1835 if (!ctx
->is_active
) {
1836 __perf_event_mark_enabled(event
);
1840 raw_spin_unlock_irq(&ctx
->lock
);
1842 if (!task_function_call(task
, __perf_event_enable
, event
))
1845 raw_spin_lock_irq(&ctx
->lock
);
1848 * If the context is active and the event is still off,
1849 * we need to retry the cross-call.
1851 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
1853 * task could have been flipped by a concurrent
1854 * perf_event_context_sched_out()
1861 raw_spin_unlock_irq(&ctx
->lock
);
1863 EXPORT_SYMBOL_GPL(perf_event_enable
);
1865 int perf_event_refresh(struct perf_event
*event
, int refresh
)
1868 * not supported on inherited events
1870 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1873 atomic_add(refresh
, &event
->event_limit
);
1874 perf_event_enable(event
);
1878 EXPORT_SYMBOL_GPL(perf_event_refresh
);
1880 static void ctx_sched_out(struct perf_event_context
*ctx
,
1881 struct perf_cpu_context
*cpuctx
,
1882 enum event_type_t event_type
)
1884 struct perf_event
*event
;
1885 int is_active
= ctx
->is_active
;
1887 ctx
->is_active
&= ~event_type
;
1888 if (likely(!ctx
->nr_events
))
1891 update_context_time(ctx
);
1892 update_cgrp_time_from_cpuctx(cpuctx
);
1893 if (!ctx
->nr_active
)
1896 perf_pmu_disable(ctx
->pmu
);
1897 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
1898 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1899 group_sched_out(event
, cpuctx
, ctx
);
1902 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
1903 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1904 group_sched_out(event
, cpuctx
, ctx
);
1906 perf_pmu_enable(ctx
->pmu
);
1910 * Test whether two contexts are equivalent, i.e. whether they
1911 * have both been cloned from the same version of the same context
1912 * and they both have the same number of enabled events.
1913 * If the number of enabled events is the same, then the set
1914 * of enabled events should be the same, because these are both
1915 * inherited contexts, therefore we can't access individual events
1916 * in them directly with an fd; we can only enable/disable all
1917 * events via prctl, or enable/disable all events in a family
1918 * via ioctl, which will have the same effect on both contexts.
1920 static int context_equiv(struct perf_event_context
*ctx1
,
1921 struct perf_event_context
*ctx2
)
1923 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1924 && ctx1
->parent_gen
== ctx2
->parent_gen
1925 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1928 static void __perf_event_sync_stat(struct perf_event
*event
,
1929 struct perf_event
*next_event
)
1933 if (!event
->attr
.inherit_stat
)
1937 * Update the event value, we cannot use perf_event_read()
1938 * because we're in the middle of a context switch and have IRQs
1939 * disabled, which upsets smp_call_function_single(), however
1940 * we know the event must be on the current CPU, therefore we
1941 * don't need to use it.
1943 switch (event
->state
) {
1944 case PERF_EVENT_STATE_ACTIVE
:
1945 event
->pmu
->read(event
);
1948 case PERF_EVENT_STATE_INACTIVE
:
1949 update_event_times(event
);
1957 * In order to keep per-task stats reliable we need to flip the event
1958 * values when we flip the contexts.
1960 value
= local64_read(&next_event
->count
);
1961 value
= local64_xchg(&event
->count
, value
);
1962 local64_set(&next_event
->count
, value
);
1964 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1965 swap(event
->total_time_running
, next_event
->total_time_running
);
1968 * Since we swizzled the values, update the user visible data too.
1970 perf_event_update_userpage(event
);
1971 perf_event_update_userpage(next_event
);
1974 #define list_next_entry(pos, member) \
1975 list_entry(pos->member.next, typeof(*pos), member)
1977 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1978 struct perf_event_context
*next_ctx
)
1980 struct perf_event
*event
, *next_event
;
1985 update_context_time(ctx
);
1987 event
= list_first_entry(&ctx
->event_list
,
1988 struct perf_event
, event_entry
);
1990 next_event
= list_first_entry(&next_ctx
->event_list
,
1991 struct perf_event
, event_entry
);
1993 while (&event
->event_entry
!= &ctx
->event_list
&&
1994 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1996 __perf_event_sync_stat(event
, next_event
);
1998 event
= list_next_entry(event
, event_entry
);
1999 next_event
= list_next_entry(next_event
, event_entry
);
2003 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2004 struct task_struct
*next
)
2006 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2007 struct perf_event_context
*next_ctx
;
2008 struct perf_event_context
*parent
;
2009 struct perf_cpu_context
*cpuctx
;
2015 cpuctx
= __get_cpu_context(ctx
);
2016 if (!cpuctx
->task_ctx
)
2020 parent
= rcu_dereference(ctx
->parent_ctx
);
2021 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2022 if (parent
&& next_ctx
&&
2023 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
2025 * Looks like the two contexts are clones, so we might be
2026 * able to optimize the context switch. We lock both
2027 * contexts and check that they are clones under the
2028 * lock (including re-checking that neither has been
2029 * uncloned in the meantime). It doesn't matter which
2030 * order we take the locks because no other cpu could
2031 * be trying to lock both of these tasks.
2033 raw_spin_lock(&ctx
->lock
);
2034 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2035 if (context_equiv(ctx
, next_ctx
)) {
2037 * XXX do we need a memory barrier of sorts
2038 * wrt to rcu_dereference() of perf_event_ctxp
2040 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2041 next
->perf_event_ctxp
[ctxn
] = ctx
;
2043 next_ctx
->task
= task
;
2046 perf_event_sync_stat(ctx
, next_ctx
);
2048 raw_spin_unlock(&next_ctx
->lock
);
2049 raw_spin_unlock(&ctx
->lock
);
2054 raw_spin_lock(&ctx
->lock
);
2055 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2056 cpuctx
->task_ctx
= NULL
;
2057 raw_spin_unlock(&ctx
->lock
);
2061 #define for_each_task_context_nr(ctxn) \
2062 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2065 * Called from scheduler to remove the events of the current task,
2066 * with interrupts disabled.
2068 * We stop each event and update the event value in event->count.
2070 * This does not protect us against NMI, but disable()
2071 * sets the disabled bit in the control field of event _before_
2072 * accessing the event control register. If a NMI hits, then it will
2073 * not restart the event.
2075 void __perf_event_task_sched_out(struct task_struct
*task
,
2076 struct task_struct
*next
)
2080 for_each_task_context_nr(ctxn
)
2081 perf_event_context_sched_out(task
, ctxn
, next
);
2084 * if cgroup events exist on this CPU, then we need
2085 * to check if we have to switch out PMU state.
2086 * cgroup event are system-wide mode only
2088 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2089 perf_cgroup_sched_out(task
, next
);
2092 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2094 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2096 if (!cpuctx
->task_ctx
)
2099 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2102 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2103 cpuctx
->task_ctx
= NULL
;
2107 * Called with IRQs disabled
2109 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2110 enum event_type_t event_type
)
2112 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2116 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2117 struct perf_cpu_context
*cpuctx
)
2119 struct perf_event
*event
;
2121 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2122 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2124 if (!event_filter_match(event
))
2127 /* may need to reset tstamp_enabled */
2128 if (is_cgroup_event(event
))
2129 perf_cgroup_mark_enabled(event
, ctx
);
2131 if (group_can_go_on(event
, cpuctx
, 1))
2132 group_sched_in(event
, cpuctx
, ctx
);
2135 * If this pinned group hasn't been scheduled,
2136 * put it in error state.
2138 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2139 update_group_times(event
);
2140 event
->state
= PERF_EVENT_STATE_ERROR
;
2146 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2147 struct perf_cpu_context
*cpuctx
)
2149 struct perf_event
*event
;
2152 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2153 /* Ignore events in OFF or ERROR state */
2154 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2157 * Listen to the 'cpu' scheduling filter constraint
2160 if (!event_filter_match(event
))
2163 /* may need to reset tstamp_enabled */
2164 if (is_cgroup_event(event
))
2165 perf_cgroup_mark_enabled(event
, ctx
);
2167 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2168 if (group_sched_in(event
, cpuctx
, ctx
))
2175 ctx_sched_in(struct perf_event_context
*ctx
,
2176 struct perf_cpu_context
*cpuctx
,
2177 enum event_type_t event_type
,
2178 struct task_struct
*task
)
2181 int is_active
= ctx
->is_active
;
2183 ctx
->is_active
|= event_type
;
2184 if (likely(!ctx
->nr_events
))
2188 ctx
->timestamp
= now
;
2189 perf_cgroup_set_timestamp(task
, ctx
);
2191 * First go through the list and put on any pinned groups
2192 * in order to give them the best chance of going on.
2194 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2195 ctx_pinned_sched_in(ctx
, cpuctx
);
2197 /* Then walk through the lower prio flexible groups */
2198 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2199 ctx_flexible_sched_in(ctx
, cpuctx
);
2202 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2203 enum event_type_t event_type
,
2204 struct task_struct
*task
)
2206 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2208 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2211 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2212 struct task_struct
*task
)
2214 struct perf_cpu_context
*cpuctx
;
2216 cpuctx
= __get_cpu_context(ctx
);
2217 if (cpuctx
->task_ctx
== ctx
)
2220 perf_ctx_lock(cpuctx
, ctx
);
2221 perf_pmu_disable(ctx
->pmu
);
2223 * We want to keep the following priority order:
2224 * cpu pinned (that don't need to move), task pinned,
2225 * cpu flexible, task flexible.
2227 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2230 cpuctx
->task_ctx
= ctx
;
2232 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2234 perf_pmu_enable(ctx
->pmu
);
2235 perf_ctx_unlock(cpuctx
, ctx
);
2238 * Since these rotations are per-cpu, we need to ensure the
2239 * cpu-context we got scheduled on is actually rotating.
2241 perf_pmu_rotate_start(ctx
->pmu
);
2245 * When sampling the branck stack in system-wide, it may be necessary
2246 * to flush the stack on context switch. This happens when the branch
2247 * stack does not tag its entries with the pid of the current task.
2248 * Otherwise it becomes impossible to associate a branch entry with a
2249 * task. This ambiguity is more likely to appear when the branch stack
2250 * supports priv level filtering and the user sets it to monitor only
2251 * at the user level (which could be a useful measurement in system-wide
2252 * mode). In that case, the risk is high of having a branch stack with
2253 * branch from multiple tasks. Flushing may mean dropping the existing
2254 * entries or stashing them somewhere in the PMU specific code layer.
2256 * This function provides the context switch callback to the lower code
2257 * layer. It is invoked ONLY when there is at least one system-wide context
2258 * with at least one active event using taken branch sampling.
2260 static void perf_branch_stack_sched_in(struct task_struct
*prev
,
2261 struct task_struct
*task
)
2263 struct perf_cpu_context
*cpuctx
;
2265 unsigned long flags
;
2267 /* no need to flush branch stack if not changing task */
2271 local_irq_save(flags
);
2275 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2276 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2279 * check if the context has at least one
2280 * event using PERF_SAMPLE_BRANCH_STACK
2282 if (cpuctx
->ctx
.nr_branch_stack
> 0
2283 && pmu
->flush_branch_stack
) {
2285 pmu
= cpuctx
->ctx
.pmu
;
2287 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2289 perf_pmu_disable(pmu
);
2291 pmu
->flush_branch_stack();
2293 perf_pmu_enable(pmu
);
2295 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2301 local_irq_restore(flags
);
2305 * Called from scheduler to add the events of the current task
2306 * with interrupts disabled.
2308 * We restore the event value and then enable it.
2310 * This does not protect us against NMI, but enable()
2311 * sets the enabled bit in the control field of event _before_
2312 * accessing the event control register. If a NMI hits, then it will
2313 * keep the event running.
2315 void __perf_event_task_sched_in(struct task_struct
*prev
,
2316 struct task_struct
*task
)
2318 struct perf_event_context
*ctx
;
2321 for_each_task_context_nr(ctxn
) {
2322 ctx
= task
->perf_event_ctxp
[ctxn
];
2326 perf_event_context_sched_in(ctx
, task
);
2329 * if cgroup events exist on this CPU, then we need
2330 * to check if we have to switch in PMU state.
2331 * cgroup event are system-wide mode only
2333 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2334 perf_cgroup_sched_in(prev
, task
);
2336 /* check for system-wide branch_stack events */
2337 if (atomic_read(&__get_cpu_var(perf_branch_stack_events
)))
2338 perf_branch_stack_sched_in(prev
, task
);
2341 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2343 u64 frequency
= event
->attr
.sample_freq
;
2344 u64 sec
= NSEC_PER_SEC
;
2345 u64 divisor
, dividend
;
2347 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2349 count_fls
= fls64(count
);
2350 nsec_fls
= fls64(nsec
);
2351 frequency_fls
= fls64(frequency
);
2355 * We got @count in @nsec, with a target of sample_freq HZ
2356 * the target period becomes:
2359 * period = -------------------
2360 * @nsec * sample_freq
2365 * Reduce accuracy by one bit such that @a and @b converge
2366 * to a similar magnitude.
2368 #define REDUCE_FLS(a, b) \
2370 if (a##_fls > b##_fls) { \
2380 * Reduce accuracy until either term fits in a u64, then proceed with
2381 * the other, so that finally we can do a u64/u64 division.
2383 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2384 REDUCE_FLS(nsec
, frequency
);
2385 REDUCE_FLS(sec
, count
);
2388 if (count_fls
+ sec_fls
> 64) {
2389 divisor
= nsec
* frequency
;
2391 while (count_fls
+ sec_fls
> 64) {
2392 REDUCE_FLS(count
, sec
);
2396 dividend
= count
* sec
;
2398 dividend
= count
* sec
;
2400 while (nsec_fls
+ frequency_fls
> 64) {
2401 REDUCE_FLS(nsec
, frequency
);
2405 divisor
= nsec
* frequency
;
2411 return div64_u64(dividend
, divisor
);
2414 static DEFINE_PER_CPU(int, perf_throttled_count
);
2415 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2417 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2419 struct hw_perf_event
*hwc
= &event
->hw
;
2420 s64 period
, sample_period
;
2423 period
= perf_calculate_period(event
, nsec
, count
);
2425 delta
= (s64
)(period
- hwc
->sample_period
);
2426 delta
= (delta
+ 7) / 8; /* low pass filter */
2428 sample_period
= hwc
->sample_period
+ delta
;
2433 hwc
->sample_period
= sample_period
;
2435 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2437 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2439 local64_set(&hwc
->period_left
, 0);
2442 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2447 * combine freq adjustment with unthrottling to avoid two passes over the
2448 * events. At the same time, make sure, having freq events does not change
2449 * the rate of unthrottling as that would introduce bias.
2451 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2454 struct perf_event
*event
;
2455 struct hw_perf_event
*hwc
;
2456 u64 now
, period
= TICK_NSEC
;
2460 * only need to iterate over all events iff:
2461 * - context have events in frequency mode (needs freq adjust)
2462 * - there are events to unthrottle on this cpu
2464 if (!(ctx
->nr_freq
|| needs_unthr
))
2467 raw_spin_lock(&ctx
->lock
);
2468 perf_pmu_disable(ctx
->pmu
);
2470 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2471 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2474 if (!event_filter_match(event
))
2479 if (needs_unthr
&& hwc
->interrupts
== MAX_INTERRUPTS
) {
2480 hwc
->interrupts
= 0;
2481 perf_log_throttle(event
, 1);
2482 event
->pmu
->start(event
, 0);
2485 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2489 * stop the event and update event->count
2491 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2493 now
= local64_read(&event
->count
);
2494 delta
= now
- hwc
->freq_count_stamp
;
2495 hwc
->freq_count_stamp
= now
;
2499 * reload only if value has changed
2500 * we have stopped the event so tell that
2501 * to perf_adjust_period() to avoid stopping it
2505 perf_adjust_period(event
, period
, delta
, false);
2507 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
2510 perf_pmu_enable(ctx
->pmu
);
2511 raw_spin_unlock(&ctx
->lock
);
2515 * Round-robin a context's events:
2517 static void rotate_ctx(struct perf_event_context
*ctx
)
2520 * Rotate the first entry last of non-pinned groups. Rotation might be
2521 * disabled by the inheritance code.
2523 if (!ctx
->rotate_disable
)
2524 list_rotate_left(&ctx
->flexible_groups
);
2528 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2529 * because they're strictly cpu affine and rotate_start is called with IRQs
2530 * disabled, while rotate_context is called from IRQ context.
2532 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2534 struct perf_event_context
*ctx
= NULL
;
2535 int rotate
= 0, remove
= 1;
2537 if (cpuctx
->ctx
.nr_events
) {
2539 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2543 ctx
= cpuctx
->task_ctx
;
2544 if (ctx
&& ctx
->nr_events
) {
2546 if (ctx
->nr_events
!= ctx
->nr_active
)
2553 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2554 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2556 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2558 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
2560 rotate_ctx(&cpuctx
->ctx
);
2564 perf_event_sched_in(cpuctx
, ctx
, current
);
2566 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2567 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2570 list_del_init(&cpuctx
->rotation_list
);
2573 void perf_event_task_tick(void)
2575 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2576 struct perf_cpu_context
*cpuctx
, *tmp
;
2577 struct perf_event_context
*ctx
;
2580 WARN_ON(!irqs_disabled());
2582 __this_cpu_inc(perf_throttled_seq
);
2583 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
2585 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2587 perf_adjust_freq_unthr_context(ctx
, throttled
);
2589 ctx
= cpuctx
->task_ctx
;
2591 perf_adjust_freq_unthr_context(ctx
, throttled
);
2593 if (cpuctx
->jiffies_interval
== 1 ||
2594 !(jiffies
% cpuctx
->jiffies_interval
))
2595 perf_rotate_context(cpuctx
);
2599 static int event_enable_on_exec(struct perf_event
*event
,
2600 struct perf_event_context
*ctx
)
2602 if (!event
->attr
.enable_on_exec
)
2605 event
->attr
.enable_on_exec
= 0;
2606 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2609 __perf_event_mark_enabled(event
);
2615 * Enable all of a task's events that have been marked enable-on-exec.
2616 * This expects task == current.
2618 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2620 struct perf_event
*event
;
2621 unsigned long flags
;
2625 local_irq_save(flags
);
2626 if (!ctx
|| !ctx
->nr_events
)
2630 * We must ctxsw out cgroup events to avoid conflict
2631 * when invoking perf_task_event_sched_in() later on
2632 * in this function. Otherwise we end up trying to
2633 * ctxswin cgroup events which are already scheduled
2636 perf_cgroup_sched_out(current
, NULL
);
2638 raw_spin_lock(&ctx
->lock
);
2639 task_ctx_sched_out(ctx
);
2641 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
2642 ret
= event_enable_on_exec(event
, ctx
);
2648 * Unclone this context if we enabled any event.
2653 raw_spin_unlock(&ctx
->lock
);
2656 * Also calls ctxswin for cgroup events, if any:
2658 perf_event_context_sched_in(ctx
, ctx
->task
);
2660 local_irq_restore(flags
);
2664 * Cross CPU call to read the hardware event
2666 static void __perf_event_read(void *info
)
2668 struct perf_event
*event
= info
;
2669 struct perf_event_context
*ctx
= event
->ctx
;
2670 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2673 * If this is a task context, we need to check whether it is
2674 * the current task context of this cpu. If not it has been
2675 * scheduled out before the smp call arrived. In that case
2676 * event->count would have been updated to a recent sample
2677 * when the event was scheduled out.
2679 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2682 raw_spin_lock(&ctx
->lock
);
2683 if (ctx
->is_active
) {
2684 update_context_time(ctx
);
2685 update_cgrp_time_from_event(event
);
2687 update_event_times(event
);
2688 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2689 event
->pmu
->read(event
);
2690 raw_spin_unlock(&ctx
->lock
);
2693 static inline u64
perf_event_count(struct perf_event
*event
)
2695 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2698 static u64
perf_event_read(struct perf_event
*event
)
2701 * If event is enabled and currently active on a CPU, update the
2702 * value in the event structure:
2704 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2705 smp_call_function_single(event
->oncpu
,
2706 __perf_event_read
, event
, 1);
2707 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2708 struct perf_event_context
*ctx
= event
->ctx
;
2709 unsigned long flags
;
2711 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2713 * may read while context is not active
2714 * (e.g., thread is blocked), in that case
2715 * we cannot update context time
2717 if (ctx
->is_active
) {
2718 update_context_time(ctx
);
2719 update_cgrp_time_from_event(event
);
2721 update_event_times(event
);
2722 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2725 return perf_event_count(event
);
2729 * Initialize the perf_event context in a task_struct:
2731 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2733 raw_spin_lock_init(&ctx
->lock
);
2734 mutex_init(&ctx
->mutex
);
2735 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2736 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2737 INIT_LIST_HEAD(&ctx
->event_list
);
2738 atomic_set(&ctx
->refcount
, 1);
2741 static struct perf_event_context
*
2742 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2744 struct perf_event_context
*ctx
;
2746 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2750 __perf_event_init_context(ctx
);
2753 get_task_struct(task
);
2760 static struct task_struct
*
2761 find_lively_task_by_vpid(pid_t vpid
)
2763 struct task_struct
*task
;
2770 task
= find_task_by_vpid(vpid
);
2772 get_task_struct(task
);
2776 return ERR_PTR(-ESRCH
);
2778 /* Reuse ptrace permission checks for now. */
2780 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2785 put_task_struct(task
);
2786 return ERR_PTR(err
);
2791 * Returns a matching context with refcount and pincount.
2793 static struct perf_event_context
*
2794 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2796 struct perf_event_context
*ctx
;
2797 struct perf_cpu_context
*cpuctx
;
2798 unsigned long flags
;
2802 /* Must be root to operate on a CPU event: */
2803 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2804 return ERR_PTR(-EACCES
);
2807 * We could be clever and allow to attach a event to an
2808 * offline CPU and activate it when the CPU comes up, but
2811 if (!cpu_online(cpu
))
2812 return ERR_PTR(-ENODEV
);
2814 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2823 ctxn
= pmu
->task_ctx_nr
;
2828 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2832 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2834 ctx
= alloc_perf_context(pmu
, task
);
2840 mutex_lock(&task
->perf_event_mutex
);
2842 * If it has already passed perf_event_exit_task().
2843 * we must see PF_EXITING, it takes this mutex too.
2845 if (task
->flags
& PF_EXITING
)
2847 else if (task
->perf_event_ctxp
[ctxn
])
2852 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2854 mutex_unlock(&task
->perf_event_mutex
);
2856 if (unlikely(err
)) {
2868 return ERR_PTR(err
);
2871 static void perf_event_free_filter(struct perf_event
*event
);
2873 static void free_event_rcu(struct rcu_head
*head
)
2875 struct perf_event
*event
;
2877 event
= container_of(head
, struct perf_event
, rcu_head
);
2879 put_pid_ns(event
->ns
);
2880 perf_event_free_filter(event
);
2884 static void ring_buffer_put(struct ring_buffer
*rb
);
2886 static void free_event(struct perf_event
*event
)
2888 irq_work_sync(&event
->pending
);
2890 if (!event
->parent
) {
2891 if (event
->attach_state
& PERF_ATTACH_TASK
)
2892 static_key_slow_dec_deferred(&perf_sched_events
);
2893 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2894 atomic_dec(&nr_mmap_events
);
2895 if (event
->attr
.comm
)
2896 atomic_dec(&nr_comm_events
);
2897 if (event
->attr
.task
)
2898 atomic_dec(&nr_task_events
);
2899 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2900 put_callchain_buffers();
2901 if (is_cgroup_event(event
)) {
2902 atomic_dec(&per_cpu(perf_cgroup_events
, event
->cpu
));
2903 static_key_slow_dec_deferred(&perf_sched_events
);
2906 if (has_branch_stack(event
)) {
2907 static_key_slow_dec_deferred(&perf_sched_events
);
2908 /* is system-wide event */
2909 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
2910 atomic_dec(&per_cpu(perf_branch_stack_events
,
2916 ring_buffer_put(event
->rb
);
2920 if (is_cgroup_event(event
))
2921 perf_detach_cgroup(event
);
2924 event
->destroy(event
);
2927 put_ctx(event
->ctx
);
2929 call_rcu(&event
->rcu_head
, free_event_rcu
);
2932 int perf_event_release_kernel(struct perf_event
*event
)
2934 struct perf_event_context
*ctx
= event
->ctx
;
2936 WARN_ON_ONCE(ctx
->parent_ctx
);
2938 * There are two ways this annotation is useful:
2940 * 1) there is a lock recursion from perf_event_exit_task
2941 * see the comment there.
2943 * 2) there is a lock-inversion with mmap_sem through
2944 * perf_event_read_group(), which takes faults while
2945 * holding ctx->mutex, however this is called after
2946 * the last filedesc died, so there is no possibility
2947 * to trigger the AB-BA case.
2949 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2950 raw_spin_lock_irq(&ctx
->lock
);
2951 perf_group_detach(event
);
2952 raw_spin_unlock_irq(&ctx
->lock
);
2953 perf_remove_from_context(event
);
2954 mutex_unlock(&ctx
->mutex
);
2960 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2963 * Called when the last reference to the file is gone.
2965 static void put_event(struct perf_event
*event
)
2967 struct task_struct
*owner
;
2969 if (!atomic_long_dec_and_test(&event
->refcount
))
2973 owner
= ACCESS_ONCE(event
->owner
);
2975 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2976 * !owner it means the list deletion is complete and we can indeed
2977 * free this event, otherwise we need to serialize on
2978 * owner->perf_event_mutex.
2980 smp_read_barrier_depends();
2983 * Since delayed_put_task_struct() also drops the last
2984 * task reference we can safely take a new reference
2985 * while holding the rcu_read_lock().
2987 get_task_struct(owner
);
2992 mutex_lock(&owner
->perf_event_mutex
);
2994 * We have to re-check the event->owner field, if it is cleared
2995 * we raced with perf_event_exit_task(), acquiring the mutex
2996 * ensured they're done, and we can proceed with freeing the
3000 list_del_init(&event
->owner_entry
);
3001 mutex_unlock(&owner
->perf_event_mutex
);
3002 put_task_struct(owner
);
3005 perf_event_release_kernel(event
);
3008 static int perf_release(struct inode
*inode
, struct file
*file
)
3010 put_event(file
->private_data
);
3014 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3016 struct perf_event
*child
;
3022 mutex_lock(&event
->child_mutex
);
3023 total
+= perf_event_read(event
);
3024 *enabled
+= event
->total_time_enabled
+
3025 atomic64_read(&event
->child_total_time_enabled
);
3026 *running
+= event
->total_time_running
+
3027 atomic64_read(&event
->child_total_time_running
);
3029 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3030 total
+= perf_event_read(child
);
3031 *enabled
+= child
->total_time_enabled
;
3032 *running
+= child
->total_time_running
;
3034 mutex_unlock(&event
->child_mutex
);
3038 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3040 static int perf_event_read_group(struct perf_event
*event
,
3041 u64 read_format
, char __user
*buf
)
3043 struct perf_event
*leader
= event
->group_leader
, *sub
;
3044 int n
= 0, size
= 0, ret
= -EFAULT
;
3045 struct perf_event_context
*ctx
= leader
->ctx
;
3047 u64 count
, enabled
, running
;
3049 mutex_lock(&ctx
->mutex
);
3050 count
= perf_event_read_value(leader
, &enabled
, &running
);
3052 values
[n
++] = 1 + leader
->nr_siblings
;
3053 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3054 values
[n
++] = enabled
;
3055 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3056 values
[n
++] = running
;
3057 values
[n
++] = count
;
3058 if (read_format
& PERF_FORMAT_ID
)
3059 values
[n
++] = primary_event_id(leader
);
3061 size
= n
* sizeof(u64
);
3063 if (copy_to_user(buf
, values
, size
))
3068 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3071 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3072 if (read_format
& PERF_FORMAT_ID
)
3073 values
[n
++] = primary_event_id(sub
);
3075 size
= n
* sizeof(u64
);
3077 if (copy_to_user(buf
+ ret
, values
, size
)) {
3085 mutex_unlock(&ctx
->mutex
);
3090 static int perf_event_read_one(struct perf_event
*event
,
3091 u64 read_format
, char __user
*buf
)
3093 u64 enabled
, running
;
3097 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3098 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3099 values
[n
++] = enabled
;
3100 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3101 values
[n
++] = running
;
3102 if (read_format
& PERF_FORMAT_ID
)
3103 values
[n
++] = primary_event_id(event
);
3105 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3108 return n
* sizeof(u64
);
3112 * Read the performance event - simple non blocking version for now
3115 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3117 u64 read_format
= event
->attr
.read_format
;
3121 * Return end-of-file for a read on a event that is in
3122 * error state (i.e. because it was pinned but it couldn't be
3123 * scheduled on to the CPU at some point).
3125 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3128 if (count
< event
->read_size
)
3131 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3132 if (read_format
& PERF_FORMAT_GROUP
)
3133 ret
= perf_event_read_group(event
, read_format
, buf
);
3135 ret
= perf_event_read_one(event
, read_format
, buf
);
3141 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3143 struct perf_event
*event
= file
->private_data
;
3145 return perf_read_hw(event
, buf
, count
);
3148 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3150 struct perf_event
*event
= file
->private_data
;
3151 struct ring_buffer
*rb
;
3152 unsigned int events
= POLL_HUP
;
3155 * Race between perf_event_set_output() and perf_poll(): perf_poll()
3156 * grabs the rb reference but perf_event_set_output() overrides it.
3157 * Here is the timeline for two threads T1, T2:
3158 * t0: T1, rb = rcu_dereference(event->rb)
3159 * t1: T2, old_rb = event->rb
3160 * t2: T2, event->rb = new rb
3161 * t3: T2, ring_buffer_detach(old_rb)
3162 * t4: T1, ring_buffer_attach(rb1)
3163 * t5: T1, poll_wait(event->waitq)
3165 * To avoid this problem, we grab mmap_mutex in perf_poll()
3166 * thereby ensuring that the assignment of the new ring buffer
3167 * and the detachment of the old buffer appear atomic to perf_poll()
3169 mutex_lock(&event
->mmap_mutex
);
3172 rb
= rcu_dereference(event
->rb
);
3174 ring_buffer_attach(event
, rb
);
3175 events
= atomic_xchg(&rb
->poll
, 0);
3179 mutex_unlock(&event
->mmap_mutex
);
3181 poll_wait(file
, &event
->waitq
, wait
);
3186 static void perf_event_reset(struct perf_event
*event
)
3188 (void)perf_event_read(event
);
3189 local64_set(&event
->count
, 0);
3190 perf_event_update_userpage(event
);
3194 * Holding the top-level event's child_mutex means that any
3195 * descendant process that has inherited this event will block
3196 * in sync_child_event if it goes to exit, thus satisfying the
3197 * task existence requirements of perf_event_enable/disable.
3199 static void perf_event_for_each_child(struct perf_event
*event
,
3200 void (*func
)(struct perf_event
*))
3202 struct perf_event
*child
;
3204 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3205 mutex_lock(&event
->child_mutex
);
3207 list_for_each_entry(child
, &event
->child_list
, child_list
)
3209 mutex_unlock(&event
->child_mutex
);
3212 static void perf_event_for_each(struct perf_event
*event
,
3213 void (*func
)(struct perf_event
*))
3215 struct perf_event_context
*ctx
= event
->ctx
;
3216 struct perf_event
*sibling
;
3218 WARN_ON_ONCE(ctx
->parent_ctx
);
3219 mutex_lock(&ctx
->mutex
);
3220 event
= event
->group_leader
;
3222 perf_event_for_each_child(event
, func
);
3223 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3224 perf_event_for_each_child(sibling
, func
);
3225 mutex_unlock(&ctx
->mutex
);
3228 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3230 struct perf_event_context
*ctx
= event
->ctx
;
3234 if (!is_sampling_event(event
))
3237 if (copy_from_user(&value
, arg
, sizeof(value
)))
3243 raw_spin_lock_irq(&ctx
->lock
);
3244 if (event
->attr
.freq
) {
3245 if (value
> sysctl_perf_event_sample_rate
) {
3250 event
->attr
.sample_freq
= value
;
3252 event
->attr
.sample_period
= value
;
3253 event
->hw
.sample_period
= value
;
3256 raw_spin_unlock_irq(&ctx
->lock
);
3261 static const struct file_operations perf_fops
;
3263 static inline int perf_fget_light(int fd
, struct fd
*p
)
3265 struct fd f
= fdget(fd
);
3269 if (f
.file
->f_op
!= &perf_fops
) {
3277 static int perf_event_set_output(struct perf_event
*event
,
3278 struct perf_event
*output_event
);
3279 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3281 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3283 struct perf_event
*event
= file
->private_data
;
3284 void (*func
)(struct perf_event
*);
3288 case PERF_EVENT_IOC_ENABLE
:
3289 func
= perf_event_enable
;
3291 case PERF_EVENT_IOC_DISABLE
:
3292 func
= perf_event_disable
;
3294 case PERF_EVENT_IOC_RESET
:
3295 func
= perf_event_reset
;
3298 case PERF_EVENT_IOC_REFRESH
:
3299 return perf_event_refresh(event
, arg
);
3301 case PERF_EVENT_IOC_PERIOD
:
3302 return perf_event_period(event
, (u64 __user
*)arg
);
3304 case PERF_EVENT_IOC_SET_OUTPUT
:
3308 struct perf_event
*output_event
;
3310 ret
= perf_fget_light(arg
, &output
);
3313 output_event
= output
.file
->private_data
;
3314 ret
= perf_event_set_output(event
, output_event
);
3317 ret
= perf_event_set_output(event
, NULL
);
3322 case PERF_EVENT_IOC_SET_FILTER
:
3323 return perf_event_set_filter(event
, (void __user
*)arg
);
3329 if (flags
& PERF_IOC_FLAG_GROUP
)
3330 perf_event_for_each(event
, func
);
3332 perf_event_for_each_child(event
, func
);
3337 int perf_event_task_enable(void)
3339 struct perf_event
*event
;
3341 mutex_lock(¤t
->perf_event_mutex
);
3342 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3343 perf_event_for_each_child(event
, perf_event_enable
);
3344 mutex_unlock(¤t
->perf_event_mutex
);
3349 int perf_event_task_disable(void)
3351 struct perf_event
*event
;
3353 mutex_lock(¤t
->perf_event_mutex
);
3354 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3355 perf_event_for_each_child(event
, perf_event_disable
);
3356 mutex_unlock(¤t
->perf_event_mutex
);
3361 static int perf_event_index(struct perf_event
*event
)
3363 if (event
->hw
.state
& PERF_HES_STOPPED
)
3366 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3369 return event
->pmu
->event_idx(event
);
3372 static void calc_timer_values(struct perf_event
*event
,
3379 *now
= perf_clock();
3380 ctx_time
= event
->shadow_ctx_time
+ *now
;
3381 *enabled
= ctx_time
- event
->tstamp_enabled
;
3382 *running
= ctx_time
- event
->tstamp_running
;
3385 void __weak
arch_perf_update_userpage(struct perf_event_mmap_page
*userpg
, u64 now
)
3390 * Callers need to ensure there can be no nesting of this function, otherwise
3391 * the seqlock logic goes bad. We can not serialize this because the arch
3392 * code calls this from NMI context.
3394 void perf_event_update_userpage(struct perf_event
*event
)
3396 struct perf_event_mmap_page
*userpg
;
3397 struct ring_buffer
*rb
;
3398 u64 enabled
, running
, now
;
3402 * compute total_time_enabled, total_time_running
3403 * based on snapshot values taken when the event
3404 * was last scheduled in.
3406 * we cannot simply called update_context_time()
3407 * because of locking issue as we can be called in
3410 calc_timer_values(event
, &now
, &enabled
, &running
);
3411 rb
= rcu_dereference(event
->rb
);
3415 userpg
= rb
->user_page
;
3418 * Disable preemption so as to not let the corresponding user-space
3419 * spin too long if we get preempted.
3424 userpg
->index
= perf_event_index(event
);
3425 userpg
->offset
= perf_event_count(event
);
3427 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3429 userpg
->time_enabled
= enabled
+
3430 atomic64_read(&event
->child_total_time_enabled
);
3432 userpg
->time_running
= running
+
3433 atomic64_read(&event
->child_total_time_running
);
3435 arch_perf_update_userpage(userpg
, now
);
3444 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3446 struct perf_event
*event
= vma
->vm_file
->private_data
;
3447 struct ring_buffer
*rb
;
3448 int ret
= VM_FAULT_SIGBUS
;
3450 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3451 if (vmf
->pgoff
== 0)
3457 rb
= rcu_dereference(event
->rb
);
3461 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3464 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3468 get_page(vmf
->page
);
3469 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3470 vmf
->page
->index
= vmf
->pgoff
;
3479 static void ring_buffer_attach(struct perf_event
*event
,
3480 struct ring_buffer
*rb
)
3482 unsigned long flags
;
3484 if (!list_empty(&event
->rb_entry
))
3487 spin_lock_irqsave(&rb
->event_lock
, flags
);
3488 if (!list_empty(&event
->rb_entry
))
3491 list_add(&event
->rb_entry
, &rb
->event_list
);
3493 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3496 static void ring_buffer_detach(struct perf_event
*event
,
3497 struct ring_buffer
*rb
)
3499 unsigned long flags
;
3501 if (list_empty(&event
->rb_entry
))
3504 spin_lock_irqsave(&rb
->event_lock
, flags
);
3505 list_del_init(&event
->rb_entry
);
3506 wake_up_all(&event
->waitq
);
3507 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3510 static void ring_buffer_wakeup(struct perf_event
*event
)
3512 struct ring_buffer
*rb
;
3515 rb
= rcu_dereference(event
->rb
);
3519 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
3520 wake_up_all(&event
->waitq
);
3526 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3528 struct ring_buffer
*rb
;
3530 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3534 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3536 struct ring_buffer
*rb
;
3539 rb
= rcu_dereference(event
->rb
);
3541 if (!atomic_inc_not_zero(&rb
->refcount
))
3549 static void ring_buffer_put(struct ring_buffer
*rb
)
3551 struct perf_event
*event
, *n
;
3552 unsigned long flags
;
3554 if (!atomic_dec_and_test(&rb
->refcount
))
3557 spin_lock_irqsave(&rb
->event_lock
, flags
);
3558 list_for_each_entry_safe(event
, n
, &rb
->event_list
, rb_entry
) {
3559 list_del_init(&event
->rb_entry
);
3560 wake_up_all(&event
->waitq
);
3562 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3564 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3567 static void perf_mmap_open(struct vm_area_struct
*vma
)
3569 struct perf_event
*event
= vma
->vm_file
->private_data
;
3571 atomic_inc(&event
->mmap_count
);
3574 static void perf_mmap_close(struct vm_area_struct
*vma
)
3576 struct perf_event
*event
= vma
->vm_file
->private_data
;
3578 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3579 unsigned long size
= perf_data_size(event
->rb
);
3580 struct user_struct
*user
= event
->mmap_user
;
3581 struct ring_buffer
*rb
= event
->rb
;
3583 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3584 vma
->vm_mm
->pinned_vm
-= event
->mmap_locked
;
3585 rcu_assign_pointer(event
->rb
, NULL
);
3586 ring_buffer_detach(event
, rb
);
3587 mutex_unlock(&event
->mmap_mutex
);
3589 ring_buffer_put(rb
);
3594 static const struct vm_operations_struct perf_mmap_vmops
= {
3595 .open
= perf_mmap_open
,
3596 .close
= perf_mmap_close
,
3597 .fault
= perf_mmap_fault
,
3598 .page_mkwrite
= perf_mmap_fault
,
3601 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3603 struct perf_event
*event
= file
->private_data
;
3604 unsigned long user_locked
, user_lock_limit
;
3605 struct user_struct
*user
= current_user();
3606 unsigned long locked
, lock_limit
;
3607 struct ring_buffer
*rb
;
3608 unsigned long vma_size
;
3609 unsigned long nr_pages
;
3610 long user_extra
, extra
;
3611 int ret
= 0, flags
= 0;
3614 * Don't allow mmap() of inherited per-task counters. This would
3615 * create a performance issue due to all children writing to the
3618 if (event
->cpu
== -1 && event
->attr
.inherit
)
3621 if (!(vma
->vm_flags
& VM_SHARED
))
3624 vma_size
= vma
->vm_end
- vma
->vm_start
;
3625 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3628 * If we have rb pages ensure they're a power-of-two number, so we
3629 * can do bitmasks instead of modulo.
3631 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3634 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3637 if (vma
->vm_pgoff
!= 0)
3640 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3641 mutex_lock(&event
->mmap_mutex
);
3643 if (event
->rb
->nr_pages
== nr_pages
)
3644 atomic_inc(&event
->rb
->refcount
);
3650 user_extra
= nr_pages
+ 1;
3651 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3654 * Increase the limit linearly with more CPUs:
3656 user_lock_limit
*= num_online_cpus();
3658 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3661 if (user_locked
> user_lock_limit
)
3662 extra
= user_locked
- user_lock_limit
;
3664 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3665 lock_limit
>>= PAGE_SHIFT
;
3666 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
3668 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3669 !capable(CAP_IPC_LOCK
)) {
3676 if (vma
->vm_flags
& VM_WRITE
)
3677 flags
|= RING_BUFFER_WRITABLE
;
3679 rb
= rb_alloc(nr_pages
,
3680 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
3687 rcu_assign_pointer(event
->rb
, rb
);
3689 atomic_long_add(user_extra
, &user
->locked_vm
);
3690 event
->mmap_locked
= extra
;
3691 event
->mmap_user
= get_current_user();
3692 vma
->vm_mm
->pinned_vm
+= event
->mmap_locked
;
3694 perf_event_update_userpage(event
);
3698 atomic_inc(&event
->mmap_count
);
3699 mutex_unlock(&event
->mmap_mutex
);
3701 vma
->vm_flags
|= VM_DONTEXPAND
| VM_DONTDUMP
;
3702 vma
->vm_ops
= &perf_mmap_vmops
;
3707 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3709 struct inode
*inode
= file_inode(filp
);
3710 struct perf_event
*event
= filp
->private_data
;
3713 mutex_lock(&inode
->i_mutex
);
3714 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3715 mutex_unlock(&inode
->i_mutex
);
3723 static const struct file_operations perf_fops
= {
3724 .llseek
= no_llseek
,
3725 .release
= perf_release
,
3728 .unlocked_ioctl
= perf_ioctl
,
3729 .compat_ioctl
= perf_ioctl
,
3731 .fasync
= perf_fasync
,
3737 * If there's data, ensure we set the poll() state and publish everything
3738 * to user-space before waking everybody up.
3741 void perf_event_wakeup(struct perf_event
*event
)
3743 ring_buffer_wakeup(event
);
3745 if (event
->pending_kill
) {
3746 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3747 event
->pending_kill
= 0;
3751 static void perf_pending_event(struct irq_work
*entry
)
3753 struct perf_event
*event
= container_of(entry
,
3754 struct perf_event
, pending
);
3756 if (event
->pending_disable
) {
3757 event
->pending_disable
= 0;
3758 __perf_event_disable(event
);
3761 if (event
->pending_wakeup
) {
3762 event
->pending_wakeup
= 0;
3763 perf_event_wakeup(event
);
3768 * We assume there is only KVM supporting the callbacks.
3769 * Later on, we might change it to a list if there is
3770 * another virtualization implementation supporting the callbacks.
3772 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3774 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3776 perf_guest_cbs
= cbs
;
3779 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3781 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3783 perf_guest_cbs
= NULL
;
3786 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3789 perf_output_sample_regs(struct perf_output_handle
*handle
,
3790 struct pt_regs
*regs
, u64 mask
)
3794 for_each_set_bit(bit
, (const unsigned long *) &mask
,
3795 sizeof(mask
) * BITS_PER_BYTE
) {
3798 val
= perf_reg_value(regs
, bit
);
3799 perf_output_put(handle
, val
);
3803 static void perf_sample_regs_user(struct perf_regs_user
*regs_user
,
3804 struct pt_regs
*regs
)
3806 if (!user_mode(regs
)) {
3808 regs
= task_pt_regs(current
);
3814 regs_user
->regs
= regs
;
3815 regs_user
->abi
= perf_reg_abi(current
);
3820 * Get remaining task size from user stack pointer.
3822 * It'd be better to take stack vma map and limit this more
3823 * precisly, but there's no way to get it safely under interrupt,
3824 * so using TASK_SIZE as limit.
3826 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
3828 unsigned long addr
= perf_user_stack_pointer(regs
);
3830 if (!addr
|| addr
>= TASK_SIZE
)
3833 return TASK_SIZE
- addr
;
3837 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
3838 struct pt_regs
*regs
)
3842 /* No regs, no stack pointer, no dump. */
3847 * Check if we fit in with the requested stack size into the:
3849 * If we don't, we limit the size to the TASK_SIZE.
3851 * - remaining sample size
3852 * If we don't, we customize the stack size to
3853 * fit in to the remaining sample size.
3856 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
3857 stack_size
= min(stack_size
, (u16
) task_size
);
3859 /* Current header size plus static size and dynamic size. */
3860 header_size
+= 2 * sizeof(u64
);
3862 /* Do we fit in with the current stack dump size? */
3863 if ((u16
) (header_size
+ stack_size
) < header_size
) {
3865 * If we overflow the maximum size for the sample,
3866 * we customize the stack dump size to fit in.
3868 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
3869 stack_size
= round_up(stack_size
, sizeof(u64
));
3876 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
3877 struct pt_regs
*regs
)
3879 /* Case of a kernel thread, nothing to dump */
3882 perf_output_put(handle
, size
);
3891 * - the size requested by user or the best one we can fit
3892 * in to the sample max size
3894 * - user stack dump data
3896 * - the actual dumped size
3900 perf_output_put(handle
, dump_size
);
3903 sp
= perf_user_stack_pointer(regs
);
3904 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
3905 dyn_size
= dump_size
- rem
;
3907 perf_output_skip(handle
, rem
);
3910 perf_output_put(handle
, dyn_size
);
3914 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3915 struct perf_sample_data
*data
,
3916 struct perf_event
*event
)
3918 u64 sample_type
= event
->attr
.sample_type
;
3920 data
->type
= sample_type
;
3921 header
->size
+= event
->id_header_size
;
3923 if (sample_type
& PERF_SAMPLE_TID
) {
3924 /* namespace issues */
3925 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3926 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3929 if (sample_type
& PERF_SAMPLE_TIME
)
3930 data
->time
= perf_clock();
3932 if (sample_type
& PERF_SAMPLE_ID
)
3933 data
->id
= primary_event_id(event
);
3935 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3936 data
->stream_id
= event
->id
;
3938 if (sample_type
& PERF_SAMPLE_CPU
) {
3939 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3940 data
->cpu_entry
.reserved
= 0;
3944 void perf_event_header__init_id(struct perf_event_header
*header
,
3945 struct perf_sample_data
*data
,
3946 struct perf_event
*event
)
3948 if (event
->attr
.sample_id_all
)
3949 __perf_event_header__init_id(header
, data
, event
);
3952 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
3953 struct perf_sample_data
*data
)
3955 u64 sample_type
= data
->type
;
3957 if (sample_type
& PERF_SAMPLE_TID
)
3958 perf_output_put(handle
, data
->tid_entry
);
3960 if (sample_type
& PERF_SAMPLE_TIME
)
3961 perf_output_put(handle
, data
->time
);
3963 if (sample_type
& PERF_SAMPLE_ID
)
3964 perf_output_put(handle
, data
->id
);
3966 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3967 perf_output_put(handle
, data
->stream_id
);
3969 if (sample_type
& PERF_SAMPLE_CPU
)
3970 perf_output_put(handle
, data
->cpu_entry
);
3973 void perf_event__output_id_sample(struct perf_event
*event
,
3974 struct perf_output_handle
*handle
,
3975 struct perf_sample_data
*sample
)
3977 if (event
->attr
.sample_id_all
)
3978 __perf_event__output_id_sample(handle
, sample
);
3981 static void perf_output_read_one(struct perf_output_handle
*handle
,
3982 struct perf_event
*event
,
3983 u64 enabled
, u64 running
)
3985 u64 read_format
= event
->attr
.read_format
;
3989 values
[n
++] = perf_event_count(event
);
3990 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3991 values
[n
++] = enabled
+
3992 atomic64_read(&event
->child_total_time_enabled
);
3994 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3995 values
[n
++] = running
+
3996 atomic64_read(&event
->child_total_time_running
);
3998 if (read_format
& PERF_FORMAT_ID
)
3999 values
[n
++] = primary_event_id(event
);
4001 __output_copy(handle
, values
, n
* sizeof(u64
));
4005 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
4007 static void perf_output_read_group(struct perf_output_handle
*handle
,
4008 struct perf_event
*event
,
4009 u64 enabled
, u64 running
)
4011 struct perf_event
*leader
= event
->group_leader
, *sub
;
4012 u64 read_format
= event
->attr
.read_format
;
4016 values
[n
++] = 1 + leader
->nr_siblings
;
4018 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4019 values
[n
++] = enabled
;
4021 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4022 values
[n
++] = running
;
4024 if (leader
!= event
)
4025 leader
->pmu
->read(leader
);
4027 values
[n
++] = perf_event_count(leader
);
4028 if (read_format
& PERF_FORMAT_ID
)
4029 values
[n
++] = primary_event_id(leader
);
4031 __output_copy(handle
, values
, n
* sizeof(u64
));
4033 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4037 sub
->pmu
->read(sub
);
4039 values
[n
++] = perf_event_count(sub
);
4040 if (read_format
& PERF_FORMAT_ID
)
4041 values
[n
++] = primary_event_id(sub
);
4043 __output_copy(handle
, values
, n
* sizeof(u64
));
4047 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
4048 PERF_FORMAT_TOTAL_TIME_RUNNING)
4050 static void perf_output_read(struct perf_output_handle
*handle
,
4051 struct perf_event
*event
)
4053 u64 enabled
= 0, running
= 0, now
;
4054 u64 read_format
= event
->attr
.read_format
;
4057 * compute total_time_enabled, total_time_running
4058 * based on snapshot values taken when the event
4059 * was last scheduled in.
4061 * we cannot simply called update_context_time()
4062 * because of locking issue as we are called in
4065 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
4066 calc_timer_values(event
, &now
, &enabled
, &running
);
4068 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
4069 perf_output_read_group(handle
, event
, enabled
, running
);
4071 perf_output_read_one(handle
, event
, enabled
, running
);
4074 void perf_output_sample(struct perf_output_handle
*handle
,
4075 struct perf_event_header
*header
,
4076 struct perf_sample_data
*data
,
4077 struct perf_event
*event
)
4079 u64 sample_type
= data
->type
;
4081 perf_output_put(handle
, *header
);
4083 if (sample_type
& PERF_SAMPLE_IP
)
4084 perf_output_put(handle
, data
->ip
);
4086 if (sample_type
& PERF_SAMPLE_TID
)
4087 perf_output_put(handle
, data
->tid_entry
);
4089 if (sample_type
& PERF_SAMPLE_TIME
)
4090 perf_output_put(handle
, data
->time
);
4092 if (sample_type
& PERF_SAMPLE_ADDR
)
4093 perf_output_put(handle
, data
->addr
);
4095 if (sample_type
& PERF_SAMPLE_ID
)
4096 perf_output_put(handle
, data
->id
);
4098 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4099 perf_output_put(handle
, data
->stream_id
);
4101 if (sample_type
& PERF_SAMPLE_CPU
)
4102 perf_output_put(handle
, data
->cpu_entry
);
4104 if (sample_type
& PERF_SAMPLE_PERIOD
)
4105 perf_output_put(handle
, data
->period
);
4107 if (sample_type
& PERF_SAMPLE_READ
)
4108 perf_output_read(handle
, event
);
4110 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4111 if (data
->callchain
) {
4114 if (data
->callchain
)
4115 size
+= data
->callchain
->nr
;
4117 size
*= sizeof(u64
);
4119 __output_copy(handle
, data
->callchain
, size
);
4122 perf_output_put(handle
, nr
);
4126 if (sample_type
& PERF_SAMPLE_RAW
) {
4128 perf_output_put(handle
, data
->raw
->size
);
4129 __output_copy(handle
, data
->raw
->data
,
4136 .size
= sizeof(u32
),
4139 perf_output_put(handle
, raw
);
4143 if (!event
->attr
.watermark
) {
4144 int wakeup_events
= event
->attr
.wakeup_events
;
4146 if (wakeup_events
) {
4147 struct ring_buffer
*rb
= handle
->rb
;
4148 int events
= local_inc_return(&rb
->events
);
4150 if (events
>= wakeup_events
) {
4151 local_sub(wakeup_events
, &rb
->events
);
4152 local_inc(&rb
->wakeup
);
4157 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4158 if (data
->br_stack
) {
4161 size
= data
->br_stack
->nr
4162 * sizeof(struct perf_branch_entry
);
4164 perf_output_put(handle
, data
->br_stack
->nr
);
4165 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
4168 * we always store at least the value of nr
4171 perf_output_put(handle
, nr
);
4175 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4176 u64 abi
= data
->regs_user
.abi
;
4179 * If there are no regs to dump, notice it through
4180 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
4182 perf_output_put(handle
, abi
);
4185 u64 mask
= event
->attr
.sample_regs_user
;
4186 perf_output_sample_regs(handle
,
4187 data
->regs_user
.regs
,
4192 if (sample_type
& PERF_SAMPLE_STACK_USER
)
4193 perf_output_sample_ustack(handle
,
4194 data
->stack_user_size
,
4195 data
->regs_user
.regs
);
4198 void perf_prepare_sample(struct perf_event_header
*header
,
4199 struct perf_sample_data
*data
,
4200 struct perf_event
*event
,
4201 struct pt_regs
*regs
)
4203 u64 sample_type
= event
->attr
.sample_type
;
4205 header
->type
= PERF_RECORD_SAMPLE
;
4206 header
->size
= sizeof(*header
) + event
->header_size
;
4209 header
->misc
|= perf_misc_flags(regs
);
4211 __perf_event_header__init_id(header
, data
, event
);
4213 if (sample_type
& PERF_SAMPLE_IP
)
4214 data
->ip
= perf_instruction_pointer(regs
);
4216 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4219 data
->callchain
= perf_callchain(event
, regs
);
4221 if (data
->callchain
)
4222 size
+= data
->callchain
->nr
;
4224 header
->size
+= size
* sizeof(u64
);
4227 if (sample_type
& PERF_SAMPLE_RAW
) {
4228 int size
= sizeof(u32
);
4231 size
+= data
->raw
->size
;
4233 size
+= sizeof(u32
);
4235 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4236 header
->size
+= size
;
4239 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4240 int size
= sizeof(u64
); /* nr */
4241 if (data
->br_stack
) {
4242 size
+= data
->br_stack
->nr
4243 * sizeof(struct perf_branch_entry
);
4245 header
->size
+= size
;
4248 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4249 /* regs dump ABI info */
4250 int size
= sizeof(u64
);
4252 perf_sample_regs_user(&data
->regs_user
, regs
);
4254 if (data
->regs_user
.regs
) {
4255 u64 mask
= event
->attr
.sample_regs_user
;
4256 size
+= hweight64(mask
) * sizeof(u64
);
4259 header
->size
+= size
;
4262 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
4264 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
4265 * processed as the last one or have additional check added
4266 * in case new sample type is added, because we could eat
4267 * up the rest of the sample size.
4269 struct perf_regs_user
*uregs
= &data
->regs_user
;
4270 u16 stack_size
= event
->attr
.sample_stack_user
;
4271 u16 size
= sizeof(u64
);
4274 perf_sample_regs_user(uregs
, regs
);
4276 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
4280 * If there is something to dump, add space for the dump
4281 * itself and for the field that tells the dynamic size,
4282 * which is how many have been actually dumped.
4285 size
+= sizeof(u64
) + stack_size
;
4287 data
->stack_user_size
= stack_size
;
4288 header
->size
+= size
;
4292 static void perf_event_output(struct perf_event
*event
,
4293 struct perf_sample_data
*data
,
4294 struct pt_regs
*regs
)
4296 struct perf_output_handle handle
;
4297 struct perf_event_header header
;
4299 /* protect the callchain buffers */
4302 perf_prepare_sample(&header
, data
, event
, regs
);
4304 if (perf_output_begin(&handle
, event
, header
.size
))
4307 perf_output_sample(&handle
, &header
, data
, event
);
4309 perf_output_end(&handle
);
4319 struct perf_read_event
{
4320 struct perf_event_header header
;
4327 perf_event_read_event(struct perf_event
*event
,
4328 struct task_struct
*task
)
4330 struct perf_output_handle handle
;
4331 struct perf_sample_data sample
;
4332 struct perf_read_event read_event
= {
4334 .type
= PERF_RECORD_READ
,
4336 .size
= sizeof(read_event
) + event
->read_size
,
4338 .pid
= perf_event_pid(event
, task
),
4339 .tid
= perf_event_tid(event
, task
),
4343 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4344 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
4348 perf_output_put(&handle
, read_event
);
4349 perf_output_read(&handle
, event
);
4350 perf_event__output_id_sample(event
, &handle
, &sample
);
4352 perf_output_end(&handle
);
4356 * task tracking -- fork/exit
4358 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
4361 struct perf_task_event
{
4362 struct task_struct
*task
;
4363 struct perf_event_context
*task_ctx
;
4366 struct perf_event_header header
;
4376 static void perf_event_task_output(struct perf_event
*event
,
4377 struct perf_task_event
*task_event
)
4379 struct perf_output_handle handle
;
4380 struct perf_sample_data sample
;
4381 struct task_struct
*task
= task_event
->task
;
4382 int ret
, size
= task_event
->event_id
.header
.size
;
4384 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4386 ret
= perf_output_begin(&handle
, event
,
4387 task_event
->event_id
.header
.size
);
4391 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4392 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4394 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4395 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4397 perf_output_put(&handle
, task_event
->event_id
);
4399 perf_event__output_id_sample(event
, &handle
, &sample
);
4401 perf_output_end(&handle
);
4403 task_event
->event_id
.header
.size
= size
;
4406 static int perf_event_task_match(struct perf_event
*event
)
4408 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4411 if (!event_filter_match(event
))
4414 if (event
->attr
.comm
|| event
->attr
.mmap
||
4415 event
->attr
.mmap_data
|| event
->attr
.task
)
4421 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
4422 struct perf_task_event
*task_event
)
4424 struct perf_event
*event
;
4426 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4427 if (perf_event_task_match(event
))
4428 perf_event_task_output(event
, task_event
);
4432 static void perf_event_task_event(struct perf_task_event
*task_event
)
4434 struct perf_cpu_context
*cpuctx
;
4435 struct perf_event_context
*ctx
;
4440 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4441 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4442 if (cpuctx
->unique_pmu
!= pmu
)
4444 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
4446 ctx
= task_event
->task_ctx
;
4448 ctxn
= pmu
->task_ctx_nr
;
4451 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4453 perf_event_task_ctx(ctx
, task_event
);
4456 put_cpu_ptr(pmu
->pmu_cpu_context
);
4458 if (task_event
->task_ctx
)
4459 perf_event_task_ctx(task_event
->task_ctx
, task_event
);
4464 static void perf_event_task(struct task_struct
*task
,
4465 struct perf_event_context
*task_ctx
,
4468 struct perf_task_event task_event
;
4470 if (!atomic_read(&nr_comm_events
) &&
4471 !atomic_read(&nr_mmap_events
) &&
4472 !atomic_read(&nr_task_events
))
4475 task_event
= (struct perf_task_event
){
4477 .task_ctx
= task_ctx
,
4480 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4482 .size
= sizeof(task_event
.event_id
),
4488 .time
= perf_clock(),
4492 perf_event_task_event(&task_event
);
4495 void perf_event_fork(struct task_struct
*task
)
4497 perf_event_task(task
, NULL
, 1);
4504 struct perf_comm_event
{
4505 struct task_struct
*task
;
4510 struct perf_event_header header
;
4517 static void perf_event_comm_output(struct perf_event
*event
,
4518 struct perf_comm_event
*comm_event
)
4520 struct perf_output_handle handle
;
4521 struct perf_sample_data sample
;
4522 int size
= comm_event
->event_id
.header
.size
;
4525 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4526 ret
= perf_output_begin(&handle
, event
,
4527 comm_event
->event_id
.header
.size
);
4532 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4533 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4535 perf_output_put(&handle
, comm_event
->event_id
);
4536 __output_copy(&handle
, comm_event
->comm
,
4537 comm_event
->comm_size
);
4539 perf_event__output_id_sample(event
, &handle
, &sample
);
4541 perf_output_end(&handle
);
4543 comm_event
->event_id
.header
.size
= size
;
4546 static int perf_event_comm_match(struct perf_event
*event
)
4548 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4551 if (!event_filter_match(event
))
4554 if (event
->attr
.comm
)
4560 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4561 struct perf_comm_event
*comm_event
)
4563 struct perf_event
*event
;
4565 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4566 if (perf_event_comm_match(event
))
4567 perf_event_comm_output(event
, comm_event
);
4571 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4573 struct perf_cpu_context
*cpuctx
;
4574 struct perf_event_context
*ctx
;
4575 char comm
[TASK_COMM_LEN
];
4580 memset(comm
, 0, sizeof(comm
));
4581 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4582 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4584 comm_event
->comm
= comm
;
4585 comm_event
->comm_size
= size
;
4587 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4589 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4590 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4591 if (cpuctx
->unique_pmu
!= pmu
)
4593 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4595 ctxn
= pmu
->task_ctx_nr
;
4599 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4601 perf_event_comm_ctx(ctx
, comm_event
);
4603 put_cpu_ptr(pmu
->pmu_cpu_context
);
4608 void perf_event_comm(struct task_struct
*task
)
4610 struct perf_comm_event comm_event
;
4611 struct perf_event_context
*ctx
;
4615 for_each_task_context_nr(ctxn
) {
4616 ctx
= task
->perf_event_ctxp
[ctxn
];
4620 perf_event_enable_on_exec(ctx
);
4624 if (!atomic_read(&nr_comm_events
))
4627 comm_event
= (struct perf_comm_event
){
4633 .type
= PERF_RECORD_COMM
,
4642 perf_event_comm_event(&comm_event
);
4649 struct perf_mmap_event
{
4650 struct vm_area_struct
*vma
;
4652 const char *file_name
;
4656 struct perf_event_header header
;
4666 static void perf_event_mmap_output(struct perf_event
*event
,
4667 struct perf_mmap_event
*mmap_event
)
4669 struct perf_output_handle handle
;
4670 struct perf_sample_data sample
;
4671 int size
= mmap_event
->event_id
.header
.size
;
4674 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4675 ret
= perf_output_begin(&handle
, event
,
4676 mmap_event
->event_id
.header
.size
);
4680 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4681 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4683 perf_output_put(&handle
, mmap_event
->event_id
);
4684 __output_copy(&handle
, mmap_event
->file_name
,
4685 mmap_event
->file_size
);
4687 perf_event__output_id_sample(event
, &handle
, &sample
);
4689 perf_output_end(&handle
);
4691 mmap_event
->event_id
.header
.size
= size
;
4694 static int perf_event_mmap_match(struct perf_event
*event
,
4695 struct perf_mmap_event
*mmap_event
,
4698 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4701 if (!event_filter_match(event
))
4704 if ((!executable
&& event
->attr
.mmap_data
) ||
4705 (executable
&& event
->attr
.mmap
))
4711 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4712 struct perf_mmap_event
*mmap_event
,
4715 struct perf_event
*event
;
4717 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4718 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4719 perf_event_mmap_output(event
, mmap_event
);
4723 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4725 struct perf_cpu_context
*cpuctx
;
4726 struct perf_event_context
*ctx
;
4727 struct vm_area_struct
*vma
= mmap_event
->vma
;
4728 struct file
*file
= vma
->vm_file
;
4736 memset(tmp
, 0, sizeof(tmp
));
4740 * d_path works from the end of the rb backwards, so we
4741 * need to add enough zero bytes after the string to handle
4742 * the 64bit alignment we do later.
4744 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4746 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4749 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4751 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4755 if (arch_vma_name(mmap_event
->vma
)) {
4756 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4758 tmp
[sizeof(tmp
) - 1] = '\0';
4763 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4765 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4766 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4767 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4769 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4770 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4771 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4775 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4780 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4782 mmap_event
->file_name
= name
;
4783 mmap_event
->file_size
= size
;
4785 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4788 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4789 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4790 if (cpuctx
->unique_pmu
!= pmu
)
4792 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4793 vma
->vm_flags
& VM_EXEC
);
4795 ctxn
= pmu
->task_ctx_nr
;
4799 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4801 perf_event_mmap_ctx(ctx
, mmap_event
,
4802 vma
->vm_flags
& VM_EXEC
);
4805 put_cpu_ptr(pmu
->pmu_cpu_context
);
4812 void perf_event_mmap(struct vm_area_struct
*vma
)
4814 struct perf_mmap_event mmap_event
;
4816 if (!atomic_read(&nr_mmap_events
))
4819 mmap_event
= (struct perf_mmap_event
){
4825 .type
= PERF_RECORD_MMAP
,
4826 .misc
= PERF_RECORD_MISC_USER
,
4831 .start
= vma
->vm_start
,
4832 .len
= vma
->vm_end
- vma
->vm_start
,
4833 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4837 perf_event_mmap_event(&mmap_event
);
4841 * IRQ throttle logging
4844 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4846 struct perf_output_handle handle
;
4847 struct perf_sample_data sample
;
4851 struct perf_event_header header
;
4855 } throttle_event
= {
4857 .type
= PERF_RECORD_THROTTLE
,
4859 .size
= sizeof(throttle_event
),
4861 .time
= perf_clock(),
4862 .id
= primary_event_id(event
),
4863 .stream_id
= event
->id
,
4867 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4869 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4871 ret
= perf_output_begin(&handle
, event
,
4872 throttle_event
.header
.size
);
4876 perf_output_put(&handle
, throttle_event
);
4877 perf_event__output_id_sample(event
, &handle
, &sample
);
4878 perf_output_end(&handle
);
4882 * Generic event overflow handling, sampling.
4885 static int __perf_event_overflow(struct perf_event
*event
,
4886 int throttle
, struct perf_sample_data
*data
,
4887 struct pt_regs
*regs
)
4889 int events
= atomic_read(&event
->event_limit
);
4890 struct hw_perf_event
*hwc
= &event
->hw
;
4895 * Non-sampling counters might still use the PMI to fold short
4896 * hardware counters, ignore those.
4898 if (unlikely(!is_sampling_event(event
)))
4901 seq
= __this_cpu_read(perf_throttled_seq
);
4902 if (seq
!= hwc
->interrupts_seq
) {
4903 hwc
->interrupts_seq
= seq
;
4904 hwc
->interrupts
= 1;
4907 if (unlikely(throttle
4908 && hwc
->interrupts
>= max_samples_per_tick
)) {
4909 __this_cpu_inc(perf_throttled_count
);
4910 hwc
->interrupts
= MAX_INTERRUPTS
;
4911 perf_log_throttle(event
, 0);
4916 if (event
->attr
.freq
) {
4917 u64 now
= perf_clock();
4918 s64 delta
= now
- hwc
->freq_time_stamp
;
4920 hwc
->freq_time_stamp
= now
;
4922 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4923 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
4927 * XXX event_limit might not quite work as expected on inherited
4931 event
->pending_kill
= POLL_IN
;
4932 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4934 event
->pending_kill
= POLL_HUP
;
4935 event
->pending_disable
= 1;
4936 irq_work_queue(&event
->pending
);
4939 if (event
->overflow_handler
)
4940 event
->overflow_handler(event
, data
, regs
);
4942 perf_event_output(event
, data
, regs
);
4944 if (event
->fasync
&& event
->pending_kill
) {
4945 event
->pending_wakeup
= 1;
4946 irq_work_queue(&event
->pending
);
4952 int perf_event_overflow(struct perf_event
*event
,
4953 struct perf_sample_data
*data
,
4954 struct pt_regs
*regs
)
4956 return __perf_event_overflow(event
, 1, data
, regs
);
4960 * Generic software event infrastructure
4963 struct swevent_htable
{
4964 struct swevent_hlist
*swevent_hlist
;
4965 struct mutex hlist_mutex
;
4968 /* Recursion avoidance in each contexts */
4969 int recursion
[PERF_NR_CONTEXTS
];
4972 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
4975 * We directly increment event->count and keep a second value in
4976 * event->hw.period_left to count intervals. This period event
4977 * is kept in the range [-sample_period, 0] so that we can use the
4981 static u64
perf_swevent_set_period(struct perf_event
*event
)
4983 struct hw_perf_event
*hwc
= &event
->hw
;
4984 u64 period
= hwc
->last_period
;
4988 hwc
->last_period
= hwc
->sample_period
;
4991 old
= val
= local64_read(&hwc
->period_left
);
4995 nr
= div64_u64(period
+ val
, period
);
4996 offset
= nr
* period
;
4998 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
5004 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
5005 struct perf_sample_data
*data
,
5006 struct pt_regs
*regs
)
5008 struct hw_perf_event
*hwc
= &event
->hw
;
5012 overflow
= perf_swevent_set_period(event
);
5014 if (hwc
->interrupts
== MAX_INTERRUPTS
)
5017 for (; overflow
; overflow
--) {
5018 if (__perf_event_overflow(event
, throttle
,
5021 * We inhibit the overflow from happening when
5022 * hwc->interrupts == MAX_INTERRUPTS.
5030 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
5031 struct perf_sample_data
*data
,
5032 struct pt_regs
*regs
)
5034 struct hw_perf_event
*hwc
= &event
->hw
;
5036 local64_add(nr
, &event
->count
);
5041 if (!is_sampling_event(event
))
5044 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
5046 return perf_swevent_overflow(event
, 1, data
, regs
);
5048 data
->period
= event
->hw
.last_period
;
5050 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
5051 return perf_swevent_overflow(event
, 1, data
, regs
);
5053 if (local64_add_negative(nr
, &hwc
->period_left
))
5056 perf_swevent_overflow(event
, 0, data
, regs
);
5059 static int perf_exclude_event(struct perf_event
*event
,
5060 struct pt_regs
*regs
)
5062 if (event
->hw
.state
& PERF_HES_STOPPED
)
5066 if (event
->attr
.exclude_user
&& user_mode(regs
))
5069 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
5076 static int perf_swevent_match(struct perf_event
*event
,
5077 enum perf_type_id type
,
5079 struct perf_sample_data
*data
,
5080 struct pt_regs
*regs
)
5082 if (event
->attr
.type
!= type
)
5085 if (event
->attr
.config
!= event_id
)
5088 if (perf_exclude_event(event
, regs
))
5094 static inline u64
swevent_hash(u64 type
, u32 event_id
)
5096 u64 val
= event_id
| (type
<< 32);
5098 return hash_64(val
, SWEVENT_HLIST_BITS
);
5101 static inline struct hlist_head
*
5102 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
5104 u64 hash
= swevent_hash(type
, event_id
);
5106 return &hlist
->heads
[hash
];
5109 /* For the read side: events when they trigger */
5110 static inline struct hlist_head
*
5111 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
5113 struct swevent_hlist
*hlist
;
5115 hlist
= rcu_dereference(swhash
->swevent_hlist
);
5119 return __find_swevent_head(hlist
, type
, event_id
);
5122 /* For the event head insertion and removal in the hlist */
5123 static inline struct hlist_head
*
5124 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
5126 struct swevent_hlist
*hlist
;
5127 u32 event_id
= event
->attr
.config
;
5128 u64 type
= event
->attr
.type
;
5131 * Event scheduling is always serialized against hlist allocation
5132 * and release. Which makes the protected version suitable here.
5133 * The context lock guarantees that.
5135 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
5136 lockdep_is_held(&event
->ctx
->lock
));
5140 return __find_swevent_head(hlist
, type
, event_id
);
5143 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
5145 struct perf_sample_data
*data
,
5146 struct pt_regs
*regs
)
5148 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5149 struct perf_event
*event
;
5150 struct hlist_head
*head
;
5153 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
5157 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5158 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
5159 perf_swevent_event(event
, nr
, data
, regs
);
5165 int perf_swevent_get_recursion_context(void)
5167 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5169 return get_recursion_context(swhash
->recursion
);
5171 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
5173 inline void perf_swevent_put_recursion_context(int rctx
)
5175 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5177 put_recursion_context(swhash
->recursion
, rctx
);
5180 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
5182 struct perf_sample_data data
;
5185 preempt_disable_notrace();
5186 rctx
= perf_swevent_get_recursion_context();
5190 perf_sample_data_init(&data
, addr
, 0);
5192 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
5194 perf_swevent_put_recursion_context(rctx
);
5195 preempt_enable_notrace();
5198 static void perf_swevent_read(struct perf_event
*event
)
5202 static int perf_swevent_add(struct perf_event
*event
, int flags
)
5204 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5205 struct hw_perf_event
*hwc
= &event
->hw
;
5206 struct hlist_head
*head
;
5208 if (is_sampling_event(event
)) {
5209 hwc
->last_period
= hwc
->sample_period
;
5210 perf_swevent_set_period(event
);
5213 hwc
->state
= !(flags
& PERF_EF_START
);
5215 head
= find_swevent_head(swhash
, event
);
5216 if (WARN_ON_ONCE(!head
))
5219 hlist_add_head_rcu(&event
->hlist_entry
, head
);
5224 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5226 hlist_del_rcu(&event
->hlist_entry
);
5229 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5231 event
->hw
.state
= 0;
5234 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5236 event
->hw
.state
= PERF_HES_STOPPED
;
5239 /* Deref the hlist from the update side */
5240 static inline struct swevent_hlist
*
5241 swevent_hlist_deref(struct swevent_htable
*swhash
)
5243 return rcu_dereference_protected(swhash
->swevent_hlist
,
5244 lockdep_is_held(&swhash
->hlist_mutex
));
5247 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5249 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5254 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5255 kfree_rcu(hlist
, rcu_head
);
5258 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5260 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5262 mutex_lock(&swhash
->hlist_mutex
);
5264 if (!--swhash
->hlist_refcount
)
5265 swevent_hlist_release(swhash
);
5267 mutex_unlock(&swhash
->hlist_mutex
);
5270 static void swevent_hlist_put(struct perf_event
*event
)
5274 if (event
->cpu
!= -1) {
5275 swevent_hlist_put_cpu(event
, event
->cpu
);
5279 for_each_possible_cpu(cpu
)
5280 swevent_hlist_put_cpu(event
, cpu
);
5283 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5285 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5288 mutex_lock(&swhash
->hlist_mutex
);
5290 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5291 struct swevent_hlist
*hlist
;
5293 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5298 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5300 swhash
->hlist_refcount
++;
5302 mutex_unlock(&swhash
->hlist_mutex
);
5307 static int swevent_hlist_get(struct perf_event
*event
)
5310 int cpu
, failed_cpu
;
5312 if (event
->cpu
!= -1)
5313 return swevent_hlist_get_cpu(event
, event
->cpu
);
5316 for_each_possible_cpu(cpu
) {
5317 err
= swevent_hlist_get_cpu(event
, cpu
);
5327 for_each_possible_cpu(cpu
) {
5328 if (cpu
== failed_cpu
)
5330 swevent_hlist_put_cpu(event
, cpu
);
5337 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5339 static void sw_perf_event_destroy(struct perf_event
*event
)
5341 u64 event_id
= event
->attr
.config
;
5343 WARN_ON(event
->parent
);
5345 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
5346 swevent_hlist_put(event
);
5349 static int perf_swevent_init(struct perf_event
*event
)
5351 u64 event_id
= event
->attr
.config
;
5353 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5357 * no branch sampling for software events
5359 if (has_branch_stack(event
))
5363 case PERF_COUNT_SW_CPU_CLOCK
:
5364 case PERF_COUNT_SW_TASK_CLOCK
:
5371 if (event_id
>= PERF_COUNT_SW_MAX
)
5374 if (!event
->parent
) {
5377 err
= swevent_hlist_get(event
);
5381 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
5382 event
->destroy
= sw_perf_event_destroy
;
5388 static int perf_swevent_event_idx(struct perf_event
*event
)
5393 static struct pmu perf_swevent
= {
5394 .task_ctx_nr
= perf_sw_context
,
5396 .event_init
= perf_swevent_init
,
5397 .add
= perf_swevent_add
,
5398 .del
= perf_swevent_del
,
5399 .start
= perf_swevent_start
,
5400 .stop
= perf_swevent_stop
,
5401 .read
= perf_swevent_read
,
5403 .event_idx
= perf_swevent_event_idx
,
5406 #ifdef CONFIG_EVENT_TRACING
5408 static int perf_tp_filter_match(struct perf_event
*event
,
5409 struct perf_sample_data
*data
)
5411 void *record
= data
->raw
->data
;
5413 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5418 static int perf_tp_event_match(struct perf_event
*event
,
5419 struct perf_sample_data
*data
,
5420 struct pt_regs
*regs
)
5422 if (event
->hw
.state
& PERF_HES_STOPPED
)
5425 * All tracepoints are from kernel-space.
5427 if (event
->attr
.exclude_kernel
)
5430 if (!perf_tp_filter_match(event
, data
))
5436 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5437 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
5438 struct task_struct
*task
)
5440 struct perf_sample_data data
;
5441 struct perf_event
*event
;
5443 struct perf_raw_record raw
= {
5448 perf_sample_data_init(&data
, addr
, 0);
5451 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5452 if (perf_tp_event_match(event
, &data
, regs
))
5453 perf_swevent_event(event
, count
, &data
, regs
);
5457 * If we got specified a target task, also iterate its context and
5458 * deliver this event there too.
5460 if (task
&& task
!= current
) {
5461 struct perf_event_context
*ctx
;
5462 struct trace_entry
*entry
= record
;
5465 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
5469 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5470 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5472 if (event
->attr
.config
!= entry
->type
)
5474 if (perf_tp_event_match(event
, &data
, regs
))
5475 perf_swevent_event(event
, count
, &data
, regs
);
5481 perf_swevent_put_recursion_context(rctx
);
5483 EXPORT_SYMBOL_GPL(perf_tp_event
);
5485 static void tp_perf_event_destroy(struct perf_event
*event
)
5487 perf_trace_destroy(event
);
5490 static int perf_tp_event_init(struct perf_event
*event
)
5494 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5498 * no branch sampling for tracepoint events
5500 if (has_branch_stack(event
))
5503 err
= perf_trace_init(event
);
5507 event
->destroy
= tp_perf_event_destroy
;
5512 static struct pmu perf_tracepoint
= {
5513 .task_ctx_nr
= perf_sw_context
,
5515 .event_init
= perf_tp_event_init
,
5516 .add
= perf_trace_add
,
5517 .del
= perf_trace_del
,
5518 .start
= perf_swevent_start
,
5519 .stop
= perf_swevent_stop
,
5520 .read
= perf_swevent_read
,
5522 .event_idx
= perf_swevent_event_idx
,
5525 static inline void perf_tp_register(void)
5527 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5530 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5535 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5538 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5539 if (IS_ERR(filter_str
))
5540 return PTR_ERR(filter_str
);
5542 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5548 static void perf_event_free_filter(struct perf_event
*event
)
5550 ftrace_profile_free_filter(event
);
5555 static inline void perf_tp_register(void)
5559 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5564 static void perf_event_free_filter(struct perf_event
*event
)
5568 #endif /* CONFIG_EVENT_TRACING */
5570 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5571 void perf_bp_event(struct perf_event
*bp
, void *data
)
5573 struct perf_sample_data sample
;
5574 struct pt_regs
*regs
= data
;
5576 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
5578 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5579 perf_swevent_event(bp
, 1, &sample
, regs
);
5584 * hrtimer based swevent callback
5587 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5589 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5590 struct perf_sample_data data
;
5591 struct pt_regs
*regs
;
5592 struct perf_event
*event
;
5595 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5597 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5598 return HRTIMER_NORESTART
;
5600 event
->pmu
->read(event
);
5602 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
5603 regs
= get_irq_regs();
5605 if (regs
&& !perf_exclude_event(event
, regs
)) {
5606 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
5607 if (__perf_event_overflow(event
, 1, &data
, regs
))
5608 ret
= HRTIMER_NORESTART
;
5611 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5612 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5617 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5619 struct hw_perf_event
*hwc
= &event
->hw
;
5622 if (!is_sampling_event(event
))
5625 period
= local64_read(&hwc
->period_left
);
5630 local64_set(&hwc
->period_left
, 0);
5632 period
= max_t(u64
, 10000, hwc
->sample_period
);
5634 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5635 ns_to_ktime(period
), 0,
5636 HRTIMER_MODE_REL_PINNED
, 0);
5639 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5641 struct hw_perf_event
*hwc
= &event
->hw
;
5643 if (is_sampling_event(event
)) {
5644 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5645 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5647 hrtimer_cancel(&hwc
->hrtimer
);
5651 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
5653 struct hw_perf_event
*hwc
= &event
->hw
;
5655 if (!is_sampling_event(event
))
5658 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5659 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5662 * Since hrtimers have a fixed rate, we can do a static freq->period
5663 * mapping and avoid the whole period adjust feedback stuff.
5665 if (event
->attr
.freq
) {
5666 long freq
= event
->attr
.sample_freq
;
5668 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
5669 hwc
->sample_period
= event
->attr
.sample_period
;
5670 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5671 hwc
->last_period
= hwc
->sample_period
;
5672 event
->attr
.freq
= 0;
5677 * Software event: cpu wall time clock
5680 static void cpu_clock_event_update(struct perf_event
*event
)
5685 now
= local_clock();
5686 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5687 local64_add(now
- prev
, &event
->count
);
5690 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5692 local64_set(&event
->hw
.prev_count
, local_clock());
5693 perf_swevent_start_hrtimer(event
);
5696 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5698 perf_swevent_cancel_hrtimer(event
);
5699 cpu_clock_event_update(event
);
5702 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5704 if (flags
& PERF_EF_START
)
5705 cpu_clock_event_start(event
, flags
);
5710 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5712 cpu_clock_event_stop(event
, flags
);
5715 static void cpu_clock_event_read(struct perf_event
*event
)
5717 cpu_clock_event_update(event
);
5720 static int cpu_clock_event_init(struct perf_event
*event
)
5722 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5725 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5729 * no branch sampling for software events
5731 if (has_branch_stack(event
))
5734 perf_swevent_init_hrtimer(event
);
5739 static struct pmu perf_cpu_clock
= {
5740 .task_ctx_nr
= perf_sw_context
,
5742 .event_init
= cpu_clock_event_init
,
5743 .add
= cpu_clock_event_add
,
5744 .del
= cpu_clock_event_del
,
5745 .start
= cpu_clock_event_start
,
5746 .stop
= cpu_clock_event_stop
,
5747 .read
= cpu_clock_event_read
,
5749 .event_idx
= perf_swevent_event_idx
,
5753 * Software event: task time clock
5756 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5761 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5763 local64_add(delta
, &event
->count
);
5766 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5768 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5769 perf_swevent_start_hrtimer(event
);
5772 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5774 perf_swevent_cancel_hrtimer(event
);
5775 task_clock_event_update(event
, event
->ctx
->time
);
5778 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5780 if (flags
& PERF_EF_START
)
5781 task_clock_event_start(event
, flags
);
5786 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5788 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5791 static void task_clock_event_read(struct perf_event
*event
)
5793 u64 now
= perf_clock();
5794 u64 delta
= now
- event
->ctx
->timestamp
;
5795 u64 time
= event
->ctx
->time
+ delta
;
5797 task_clock_event_update(event
, time
);
5800 static int task_clock_event_init(struct perf_event
*event
)
5802 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5805 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5809 * no branch sampling for software events
5811 if (has_branch_stack(event
))
5814 perf_swevent_init_hrtimer(event
);
5819 static struct pmu perf_task_clock
= {
5820 .task_ctx_nr
= perf_sw_context
,
5822 .event_init
= task_clock_event_init
,
5823 .add
= task_clock_event_add
,
5824 .del
= task_clock_event_del
,
5825 .start
= task_clock_event_start
,
5826 .stop
= task_clock_event_stop
,
5827 .read
= task_clock_event_read
,
5829 .event_idx
= perf_swevent_event_idx
,
5832 static void perf_pmu_nop_void(struct pmu
*pmu
)
5836 static int perf_pmu_nop_int(struct pmu
*pmu
)
5841 static void perf_pmu_start_txn(struct pmu
*pmu
)
5843 perf_pmu_disable(pmu
);
5846 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5848 perf_pmu_enable(pmu
);
5852 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5854 perf_pmu_enable(pmu
);
5857 static int perf_event_idx_default(struct perf_event
*event
)
5859 return event
->hw
.idx
+ 1;
5863 * Ensures all contexts with the same task_ctx_nr have the same
5864 * pmu_cpu_context too.
5866 static void *find_pmu_context(int ctxn
)
5873 list_for_each_entry(pmu
, &pmus
, entry
) {
5874 if (pmu
->task_ctx_nr
== ctxn
)
5875 return pmu
->pmu_cpu_context
;
5881 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5885 for_each_possible_cpu(cpu
) {
5886 struct perf_cpu_context
*cpuctx
;
5888 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5890 if (cpuctx
->unique_pmu
== old_pmu
)
5891 cpuctx
->unique_pmu
= pmu
;
5895 static void free_pmu_context(struct pmu
*pmu
)
5899 mutex_lock(&pmus_lock
);
5901 * Like a real lame refcount.
5903 list_for_each_entry(i
, &pmus
, entry
) {
5904 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5905 update_pmu_context(i
, pmu
);
5910 free_percpu(pmu
->pmu_cpu_context
);
5912 mutex_unlock(&pmus_lock
);
5914 static struct idr pmu_idr
;
5917 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5919 struct pmu
*pmu
= dev_get_drvdata(dev
);
5921 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5924 static struct device_attribute pmu_dev_attrs
[] = {
5929 static int pmu_bus_running
;
5930 static struct bus_type pmu_bus
= {
5931 .name
= "event_source",
5932 .dev_attrs
= pmu_dev_attrs
,
5935 static void pmu_dev_release(struct device
*dev
)
5940 static int pmu_dev_alloc(struct pmu
*pmu
)
5944 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5948 pmu
->dev
->groups
= pmu
->attr_groups
;
5949 device_initialize(pmu
->dev
);
5950 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5954 dev_set_drvdata(pmu
->dev
, pmu
);
5955 pmu
->dev
->bus
= &pmu_bus
;
5956 pmu
->dev
->release
= pmu_dev_release
;
5957 ret
= device_add(pmu
->dev
);
5965 put_device(pmu
->dev
);
5969 static struct lock_class_key cpuctx_mutex
;
5970 static struct lock_class_key cpuctx_lock
;
5972 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5976 mutex_lock(&pmus_lock
);
5978 pmu
->pmu_disable_count
= alloc_percpu(int);
5979 if (!pmu
->pmu_disable_count
)
5988 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
5996 if (pmu_bus_running
) {
5997 ret
= pmu_dev_alloc(pmu
);
6003 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
6004 if (pmu
->pmu_cpu_context
)
6005 goto got_cpu_context
;
6008 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
6009 if (!pmu
->pmu_cpu_context
)
6012 for_each_possible_cpu(cpu
) {
6013 struct perf_cpu_context
*cpuctx
;
6015 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6016 __perf_event_init_context(&cpuctx
->ctx
);
6017 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
6018 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
6019 cpuctx
->ctx
.type
= cpu_context
;
6020 cpuctx
->ctx
.pmu
= pmu
;
6021 cpuctx
->jiffies_interval
= 1;
6022 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
6023 cpuctx
->unique_pmu
= pmu
;
6027 if (!pmu
->start_txn
) {
6028 if (pmu
->pmu_enable
) {
6030 * If we have pmu_enable/pmu_disable calls, install
6031 * transaction stubs that use that to try and batch
6032 * hardware accesses.
6034 pmu
->start_txn
= perf_pmu_start_txn
;
6035 pmu
->commit_txn
= perf_pmu_commit_txn
;
6036 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
6038 pmu
->start_txn
= perf_pmu_nop_void
;
6039 pmu
->commit_txn
= perf_pmu_nop_int
;
6040 pmu
->cancel_txn
= perf_pmu_nop_void
;
6044 if (!pmu
->pmu_enable
) {
6045 pmu
->pmu_enable
= perf_pmu_nop_void
;
6046 pmu
->pmu_disable
= perf_pmu_nop_void
;
6049 if (!pmu
->event_idx
)
6050 pmu
->event_idx
= perf_event_idx_default
;
6052 list_add_rcu(&pmu
->entry
, &pmus
);
6055 mutex_unlock(&pmus_lock
);
6060 device_del(pmu
->dev
);
6061 put_device(pmu
->dev
);
6064 if (pmu
->type
>= PERF_TYPE_MAX
)
6065 idr_remove(&pmu_idr
, pmu
->type
);
6068 free_percpu(pmu
->pmu_disable_count
);
6072 void perf_pmu_unregister(struct pmu
*pmu
)
6074 mutex_lock(&pmus_lock
);
6075 list_del_rcu(&pmu
->entry
);
6076 mutex_unlock(&pmus_lock
);
6079 * We dereference the pmu list under both SRCU and regular RCU, so
6080 * synchronize against both of those.
6082 synchronize_srcu(&pmus_srcu
);
6085 free_percpu(pmu
->pmu_disable_count
);
6086 if (pmu
->type
>= PERF_TYPE_MAX
)
6087 idr_remove(&pmu_idr
, pmu
->type
);
6088 device_del(pmu
->dev
);
6089 put_device(pmu
->dev
);
6090 free_pmu_context(pmu
);
6093 struct pmu
*perf_init_event(struct perf_event
*event
)
6095 struct pmu
*pmu
= NULL
;
6099 idx
= srcu_read_lock(&pmus_srcu
);
6102 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
6106 ret
= pmu
->event_init(event
);
6112 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6114 ret
= pmu
->event_init(event
);
6118 if (ret
!= -ENOENT
) {
6123 pmu
= ERR_PTR(-ENOENT
);
6125 srcu_read_unlock(&pmus_srcu
, idx
);
6131 * Allocate and initialize a event structure
6133 static struct perf_event
*
6134 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
6135 struct task_struct
*task
,
6136 struct perf_event
*group_leader
,
6137 struct perf_event
*parent_event
,
6138 perf_overflow_handler_t overflow_handler
,
6142 struct perf_event
*event
;
6143 struct hw_perf_event
*hwc
;
6146 if ((unsigned)cpu
>= nr_cpu_ids
) {
6147 if (!task
|| cpu
!= -1)
6148 return ERR_PTR(-EINVAL
);
6151 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
6153 return ERR_PTR(-ENOMEM
);
6156 * Single events are their own group leaders, with an
6157 * empty sibling list:
6160 group_leader
= event
;
6162 mutex_init(&event
->child_mutex
);
6163 INIT_LIST_HEAD(&event
->child_list
);
6165 INIT_LIST_HEAD(&event
->group_entry
);
6166 INIT_LIST_HEAD(&event
->event_entry
);
6167 INIT_LIST_HEAD(&event
->sibling_list
);
6168 INIT_LIST_HEAD(&event
->rb_entry
);
6170 init_waitqueue_head(&event
->waitq
);
6171 init_irq_work(&event
->pending
, perf_pending_event
);
6173 mutex_init(&event
->mmap_mutex
);
6175 atomic_long_set(&event
->refcount
, 1);
6177 event
->attr
= *attr
;
6178 event
->group_leader
= group_leader
;
6182 event
->parent
= parent_event
;
6184 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
6185 event
->id
= atomic64_inc_return(&perf_event_id
);
6187 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6190 event
->attach_state
= PERF_ATTACH_TASK
;
6192 if (attr
->type
== PERF_TYPE_TRACEPOINT
)
6193 event
->hw
.tp_target
= task
;
6194 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6196 * hw_breakpoint is a bit difficult here..
6198 else if (attr
->type
== PERF_TYPE_BREAKPOINT
)
6199 event
->hw
.bp_target
= task
;
6203 if (!overflow_handler
&& parent_event
) {
6204 overflow_handler
= parent_event
->overflow_handler
;
6205 context
= parent_event
->overflow_handler_context
;
6208 event
->overflow_handler
= overflow_handler
;
6209 event
->overflow_handler_context
= context
;
6211 perf_event__state_init(event
);
6216 hwc
->sample_period
= attr
->sample_period
;
6217 if (attr
->freq
&& attr
->sample_freq
)
6218 hwc
->sample_period
= 1;
6219 hwc
->last_period
= hwc
->sample_period
;
6221 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6224 * we currently do not support PERF_FORMAT_GROUP on inherited events
6226 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
6229 pmu
= perf_init_event(event
);
6235 else if (IS_ERR(pmu
))
6240 put_pid_ns(event
->ns
);
6242 return ERR_PTR(err
);
6245 if (!event
->parent
) {
6246 if (event
->attach_state
& PERF_ATTACH_TASK
)
6247 static_key_slow_inc(&perf_sched_events
.key
);
6248 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
6249 atomic_inc(&nr_mmap_events
);
6250 if (event
->attr
.comm
)
6251 atomic_inc(&nr_comm_events
);
6252 if (event
->attr
.task
)
6253 atomic_inc(&nr_task_events
);
6254 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6255 err
= get_callchain_buffers();
6258 return ERR_PTR(err
);
6261 if (has_branch_stack(event
)) {
6262 static_key_slow_inc(&perf_sched_events
.key
);
6263 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
6264 atomic_inc(&per_cpu(perf_branch_stack_events
,
6272 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6273 struct perf_event_attr
*attr
)
6278 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6282 * zero the full structure, so that a short copy will be nice.
6284 memset(attr
, 0, sizeof(*attr
));
6286 ret
= get_user(size
, &uattr
->size
);
6290 if (size
> PAGE_SIZE
) /* silly large */
6293 if (!size
) /* abi compat */
6294 size
= PERF_ATTR_SIZE_VER0
;
6296 if (size
< PERF_ATTR_SIZE_VER0
)
6300 * If we're handed a bigger struct than we know of,
6301 * ensure all the unknown bits are 0 - i.e. new
6302 * user-space does not rely on any kernel feature
6303 * extensions we dont know about yet.
6305 if (size
> sizeof(*attr
)) {
6306 unsigned char __user
*addr
;
6307 unsigned char __user
*end
;
6310 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6311 end
= (void __user
*)uattr
+ size
;
6313 for (; addr
< end
; addr
++) {
6314 ret
= get_user(val
, addr
);
6320 size
= sizeof(*attr
);
6323 ret
= copy_from_user(attr
, uattr
, size
);
6327 if (attr
->__reserved_1
)
6330 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6333 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6336 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6337 u64 mask
= attr
->branch_sample_type
;
6339 /* only using defined bits */
6340 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
6343 /* at least one branch bit must be set */
6344 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
6347 /* kernel level capture: check permissions */
6348 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
6349 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6352 /* propagate priv level, when not set for branch */
6353 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
6355 /* exclude_kernel checked on syscall entry */
6356 if (!attr
->exclude_kernel
)
6357 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
6359 if (!attr
->exclude_user
)
6360 mask
|= PERF_SAMPLE_BRANCH_USER
;
6362 if (!attr
->exclude_hv
)
6363 mask
|= PERF_SAMPLE_BRANCH_HV
;
6365 * adjust user setting (for HW filter setup)
6367 attr
->branch_sample_type
= mask
;
6371 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
6372 ret
= perf_reg_validate(attr
->sample_regs_user
);
6377 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
6378 if (!arch_perf_have_user_stack_dump())
6382 * We have __u32 type for the size, but so far
6383 * we can only use __u16 as maximum due to the
6384 * __u16 sample size limit.
6386 if (attr
->sample_stack_user
>= USHRT_MAX
)
6388 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
6396 put_user(sizeof(*attr
), &uattr
->size
);
6402 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
6404 struct ring_buffer
*rb
= NULL
, *old_rb
= NULL
;
6410 /* don't allow circular references */
6411 if (event
== output_event
)
6415 * Don't allow cross-cpu buffers
6417 if (output_event
->cpu
!= event
->cpu
)
6421 * If its not a per-cpu rb, it must be the same task.
6423 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
6427 mutex_lock(&event
->mmap_mutex
);
6428 /* Can't redirect output if we've got an active mmap() */
6429 if (atomic_read(&event
->mmap_count
))
6433 /* get the rb we want to redirect to */
6434 rb
= ring_buffer_get(output_event
);
6440 rcu_assign_pointer(event
->rb
, rb
);
6442 ring_buffer_detach(event
, old_rb
);
6445 mutex_unlock(&event
->mmap_mutex
);
6448 ring_buffer_put(old_rb
);
6454 * sys_perf_event_open - open a performance event, associate it to a task/cpu
6456 * @attr_uptr: event_id type attributes for monitoring/sampling
6459 * @group_fd: group leader event fd
6461 SYSCALL_DEFINE5(perf_event_open
,
6462 struct perf_event_attr __user
*, attr_uptr
,
6463 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
6465 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
6466 struct perf_event
*event
, *sibling
;
6467 struct perf_event_attr attr
;
6468 struct perf_event_context
*ctx
;
6469 struct file
*event_file
= NULL
;
6470 struct fd group
= {NULL
, 0};
6471 struct task_struct
*task
= NULL
;
6477 /* for future expandability... */
6478 if (flags
& ~PERF_FLAG_ALL
)
6481 err
= perf_copy_attr(attr_uptr
, &attr
);
6485 if (!attr
.exclude_kernel
) {
6486 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6491 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
6496 * In cgroup mode, the pid argument is used to pass the fd
6497 * opened to the cgroup directory in cgroupfs. The cpu argument
6498 * designates the cpu on which to monitor threads from that
6501 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
6504 event_fd
= get_unused_fd();
6508 if (group_fd
!= -1) {
6509 err
= perf_fget_light(group_fd
, &group
);
6512 group_leader
= group
.file
->private_data
;
6513 if (flags
& PERF_FLAG_FD_OUTPUT
)
6514 output_event
= group_leader
;
6515 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6516 group_leader
= NULL
;
6519 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6520 task
= find_lively_task_by_vpid(pid
);
6522 err
= PTR_ERR(task
);
6529 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
6531 if (IS_ERR(event
)) {
6532 err
= PTR_ERR(event
);
6536 if (flags
& PERF_FLAG_PID_CGROUP
) {
6537 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6542 * - that has cgroup constraint on event->cpu
6543 * - that may need work on context switch
6545 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
6546 static_key_slow_inc(&perf_sched_events
.key
);
6550 * Special case software events and allow them to be part of
6551 * any hardware group.
6556 (is_software_event(event
) != is_software_event(group_leader
))) {
6557 if (is_software_event(event
)) {
6559 * If event and group_leader are not both a software
6560 * event, and event is, then group leader is not.
6562 * Allow the addition of software events to !software
6563 * groups, this is safe because software events never
6566 pmu
= group_leader
->pmu
;
6567 } else if (is_software_event(group_leader
) &&
6568 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6570 * In case the group is a pure software group, and we
6571 * try to add a hardware event, move the whole group to
6572 * the hardware context.
6579 * Get the target context (task or percpu):
6581 ctx
= find_get_context(pmu
, task
, event
->cpu
);
6588 put_task_struct(task
);
6593 * Look up the group leader (we will attach this event to it):
6599 * Do not allow a recursive hierarchy (this new sibling
6600 * becoming part of another group-sibling):
6602 if (group_leader
->group_leader
!= group_leader
)
6605 * Do not allow to attach to a group in a different
6606 * task or CPU context:
6609 if (group_leader
->ctx
->type
!= ctx
->type
)
6612 if (group_leader
->ctx
!= ctx
)
6617 * Only a group leader can be exclusive or pinned
6619 if (attr
.exclusive
|| attr
.pinned
)
6624 err
= perf_event_set_output(event
, output_event
);
6629 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6630 if (IS_ERR(event_file
)) {
6631 err
= PTR_ERR(event_file
);
6636 struct perf_event_context
*gctx
= group_leader
->ctx
;
6638 mutex_lock(&gctx
->mutex
);
6639 perf_remove_from_context(group_leader
);
6642 * Removing from the context ends up with disabled
6643 * event. What we want here is event in the initial
6644 * startup state, ready to be add into new context.
6646 perf_event__state_init(group_leader
);
6647 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6649 perf_remove_from_context(sibling
);
6650 perf_event__state_init(sibling
);
6653 mutex_unlock(&gctx
->mutex
);
6657 WARN_ON_ONCE(ctx
->parent_ctx
);
6658 mutex_lock(&ctx
->mutex
);
6662 perf_install_in_context(ctx
, group_leader
, event
->cpu
);
6664 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6666 perf_install_in_context(ctx
, sibling
, event
->cpu
);
6671 perf_install_in_context(ctx
, event
, event
->cpu
);
6673 perf_unpin_context(ctx
);
6674 mutex_unlock(&ctx
->mutex
);
6678 event
->owner
= current
;
6680 mutex_lock(¤t
->perf_event_mutex
);
6681 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6682 mutex_unlock(¤t
->perf_event_mutex
);
6685 * Precalculate sample_data sizes
6687 perf_event__header_size(event
);
6688 perf_event__id_header_size(event
);
6691 * Drop the reference on the group_event after placing the
6692 * new event on the sibling_list. This ensures destruction
6693 * of the group leader will find the pointer to itself in
6694 * perf_group_detach().
6697 fd_install(event_fd
, event_file
);
6701 perf_unpin_context(ctx
);
6708 put_task_struct(task
);
6712 put_unused_fd(event_fd
);
6717 * perf_event_create_kernel_counter
6719 * @attr: attributes of the counter to create
6720 * @cpu: cpu in which the counter is bound
6721 * @task: task to profile (NULL for percpu)
6724 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6725 struct task_struct
*task
,
6726 perf_overflow_handler_t overflow_handler
,
6729 struct perf_event_context
*ctx
;
6730 struct perf_event
*event
;
6734 * Get the target context (task or percpu):
6737 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
6738 overflow_handler
, context
);
6739 if (IS_ERR(event
)) {
6740 err
= PTR_ERR(event
);
6744 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6750 WARN_ON_ONCE(ctx
->parent_ctx
);
6751 mutex_lock(&ctx
->mutex
);
6752 perf_install_in_context(ctx
, event
, cpu
);
6754 perf_unpin_context(ctx
);
6755 mutex_unlock(&ctx
->mutex
);
6762 return ERR_PTR(err
);
6764 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6766 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
6768 struct perf_event_context
*src_ctx
;
6769 struct perf_event_context
*dst_ctx
;
6770 struct perf_event
*event
, *tmp
;
6773 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
6774 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
6776 mutex_lock(&src_ctx
->mutex
);
6777 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
6779 perf_remove_from_context(event
);
6781 list_add(&event
->event_entry
, &events
);
6783 mutex_unlock(&src_ctx
->mutex
);
6787 mutex_lock(&dst_ctx
->mutex
);
6788 list_for_each_entry_safe(event
, tmp
, &events
, event_entry
) {
6789 list_del(&event
->event_entry
);
6790 if (event
->state
>= PERF_EVENT_STATE_OFF
)
6791 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6792 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
6795 mutex_unlock(&dst_ctx
->mutex
);
6797 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
6799 static void sync_child_event(struct perf_event
*child_event
,
6800 struct task_struct
*child
)
6802 struct perf_event
*parent_event
= child_event
->parent
;
6805 if (child_event
->attr
.inherit_stat
)
6806 perf_event_read_event(child_event
, child
);
6808 child_val
= perf_event_count(child_event
);
6811 * Add back the child's count to the parent's count:
6813 atomic64_add(child_val
, &parent_event
->child_count
);
6814 atomic64_add(child_event
->total_time_enabled
,
6815 &parent_event
->child_total_time_enabled
);
6816 atomic64_add(child_event
->total_time_running
,
6817 &parent_event
->child_total_time_running
);
6820 * Remove this event from the parent's list
6822 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6823 mutex_lock(&parent_event
->child_mutex
);
6824 list_del_init(&child_event
->child_list
);
6825 mutex_unlock(&parent_event
->child_mutex
);
6828 * Release the parent event, if this was the last
6831 put_event(parent_event
);
6835 __perf_event_exit_task(struct perf_event
*child_event
,
6836 struct perf_event_context
*child_ctx
,
6837 struct task_struct
*child
)
6839 if (child_event
->parent
) {
6840 raw_spin_lock_irq(&child_ctx
->lock
);
6841 perf_group_detach(child_event
);
6842 raw_spin_unlock_irq(&child_ctx
->lock
);
6845 perf_remove_from_context(child_event
);
6848 * It can happen that the parent exits first, and has events
6849 * that are still around due to the child reference. These
6850 * events need to be zapped.
6852 if (child_event
->parent
) {
6853 sync_child_event(child_event
, child
);
6854 free_event(child_event
);
6858 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6860 struct perf_event
*child_event
, *tmp
;
6861 struct perf_event_context
*child_ctx
;
6862 unsigned long flags
;
6864 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6865 perf_event_task(child
, NULL
, 0);
6869 local_irq_save(flags
);
6871 * We can't reschedule here because interrupts are disabled,
6872 * and either child is current or it is a task that can't be
6873 * scheduled, so we are now safe from rescheduling changing
6876 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6879 * Take the context lock here so that if find_get_context is
6880 * reading child->perf_event_ctxp, we wait until it has
6881 * incremented the context's refcount before we do put_ctx below.
6883 raw_spin_lock(&child_ctx
->lock
);
6884 task_ctx_sched_out(child_ctx
);
6885 child
->perf_event_ctxp
[ctxn
] = NULL
;
6887 * If this context is a clone; unclone it so it can't get
6888 * swapped to another process while we're removing all
6889 * the events from it.
6891 unclone_ctx(child_ctx
);
6892 update_context_time(child_ctx
);
6893 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6896 * Report the task dead after unscheduling the events so that we
6897 * won't get any samples after PERF_RECORD_EXIT. We can however still
6898 * get a few PERF_RECORD_READ events.
6900 perf_event_task(child
, child_ctx
, 0);
6903 * We can recurse on the same lock type through:
6905 * __perf_event_exit_task()
6906 * sync_child_event()
6908 * mutex_lock(&ctx->mutex)
6910 * But since its the parent context it won't be the same instance.
6912 mutex_lock(&child_ctx
->mutex
);
6915 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6917 __perf_event_exit_task(child_event
, child_ctx
, child
);
6919 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6921 __perf_event_exit_task(child_event
, child_ctx
, child
);
6924 * If the last event was a group event, it will have appended all
6925 * its siblings to the list, but we obtained 'tmp' before that which
6926 * will still point to the list head terminating the iteration.
6928 if (!list_empty(&child_ctx
->pinned_groups
) ||
6929 !list_empty(&child_ctx
->flexible_groups
))
6932 mutex_unlock(&child_ctx
->mutex
);
6938 * When a child task exits, feed back event values to parent events.
6940 void perf_event_exit_task(struct task_struct
*child
)
6942 struct perf_event
*event
, *tmp
;
6945 mutex_lock(&child
->perf_event_mutex
);
6946 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6948 list_del_init(&event
->owner_entry
);
6951 * Ensure the list deletion is visible before we clear
6952 * the owner, closes a race against perf_release() where
6953 * we need to serialize on the owner->perf_event_mutex.
6956 event
->owner
= NULL
;
6958 mutex_unlock(&child
->perf_event_mutex
);
6960 for_each_task_context_nr(ctxn
)
6961 perf_event_exit_task_context(child
, ctxn
);
6964 static void perf_free_event(struct perf_event
*event
,
6965 struct perf_event_context
*ctx
)
6967 struct perf_event
*parent
= event
->parent
;
6969 if (WARN_ON_ONCE(!parent
))
6972 mutex_lock(&parent
->child_mutex
);
6973 list_del_init(&event
->child_list
);
6974 mutex_unlock(&parent
->child_mutex
);
6978 perf_group_detach(event
);
6979 list_del_event(event
, ctx
);
6984 * free an unexposed, unused context as created by inheritance by
6985 * perf_event_init_task below, used by fork() in case of fail.
6987 void perf_event_free_task(struct task_struct
*task
)
6989 struct perf_event_context
*ctx
;
6990 struct perf_event
*event
, *tmp
;
6993 for_each_task_context_nr(ctxn
) {
6994 ctx
= task
->perf_event_ctxp
[ctxn
];
6998 mutex_lock(&ctx
->mutex
);
7000 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
7002 perf_free_event(event
, ctx
);
7004 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
7006 perf_free_event(event
, ctx
);
7008 if (!list_empty(&ctx
->pinned_groups
) ||
7009 !list_empty(&ctx
->flexible_groups
))
7012 mutex_unlock(&ctx
->mutex
);
7018 void perf_event_delayed_put(struct task_struct
*task
)
7022 for_each_task_context_nr(ctxn
)
7023 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
7027 * inherit a event from parent task to child task:
7029 static struct perf_event
*
7030 inherit_event(struct perf_event
*parent_event
,
7031 struct task_struct
*parent
,
7032 struct perf_event_context
*parent_ctx
,
7033 struct task_struct
*child
,
7034 struct perf_event
*group_leader
,
7035 struct perf_event_context
*child_ctx
)
7037 struct perf_event
*child_event
;
7038 unsigned long flags
;
7041 * Instead of creating recursive hierarchies of events,
7042 * we link inherited events back to the original parent,
7043 * which has a filp for sure, which we use as the reference
7046 if (parent_event
->parent
)
7047 parent_event
= parent_event
->parent
;
7049 child_event
= perf_event_alloc(&parent_event
->attr
,
7052 group_leader
, parent_event
,
7054 if (IS_ERR(child_event
))
7057 if (!atomic_long_inc_not_zero(&parent_event
->refcount
)) {
7058 free_event(child_event
);
7065 * Make the child state follow the state of the parent event,
7066 * not its attr.disabled bit. We hold the parent's mutex,
7067 * so we won't race with perf_event_{en, dis}able_family.
7069 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
7070 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
7072 child_event
->state
= PERF_EVENT_STATE_OFF
;
7074 if (parent_event
->attr
.freq
) {
7075 u64 sample_period
= parent_event
->hw
.sample_period
;
7076 struct hw_perf_event
*hwc
= &child_event
->hw
;
7078 hwc
->sample_period
= sample_period
;
7079 hwc
->last_period
= sample_period
;
7081 local64_set(&hwc
->period_left
, sample_period
);
7084 child_event
->ctx
= child_ctx
;
7085 child_event
->overflow_handler
= parent_event
->overflow_handler
;
7086 child_event
->overflow_handler_context
7087 = parent_event
->overflow_handler_context
;
7090 * Precalculate sample_data sizes
7092 perf_event__header_size(child_event
);
7093 perf_event__id_header_size(child_event
);
7096 * Link it up in the child's context:
7098 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
7099 add_event_to_ctx(child_event
, child_ctx
);
7100 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
7103 * Link this into the parent event's child list
7105 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7106 mutex_lock(&parent_event
->child_mutex
);
7107 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
7108 mutex_unlock(&parent_event
->child_mutex
);
7113 static int inherit_group(struct perf_event
*parent_event
,
7114 struct task_struct
*parent
,
7115 struct perf_event_context
*parent_ctx
,
7116 struct task_struct
*child
,
7117 struct perf_event_context
*child_ctx
)
7119 struct perf_event
*leader
;
7120 struct perf_event
*sub
;
7121 struct perf_event
*child_ctr
;
7123 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
7124 child
, NULL
, child_ctx
);
7126 return PTR_ERR(leader
);
7127 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
7128 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
7129 child
, leader
, child_ctx
);
7130 if (IS_ERR(child_ctr
))
7131 return PTR_ERR(child_ctr
);
7137 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
7138 struct perf_event_context
*parent_ctx
,
7139 struct task_struct
*child
, int ctxn
,
7143 struct perf_event_context
*child_ctx
;
7145 if (!event
->attr
.inherit
) {
7150 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7153 * This is executed from the parent task context, so
7154 * inherit events that have been marked for cloning.
7155 * First allocate and initialize a context for the
7159 child_ctx
= alloc_perf_context(event
->pmu
, child
);
7163 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
7166 ret
= inherit_group(event
, parent
, parent_ctx
,
7176 * Initialize the perf_event context in task_struct
7178 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
7180 struct perf_event_context
*child_ctx
, *parent_ctx
;
7181 struct perf_event_context
*cloned_ctx
;
7182 struct perf_event
*event
;
7183 struct task_struct
*parent
= current
;
7184 int inherited_all
= 1;
7185 unsigned long flags
;
7188 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
7192 * If the parent's context is a clone, pin it so it won't get
7195 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
7198 * No need to check if parent_ctx != NULL here; since we saw
7199 * it non-NULL earlier, the only reason for it to become NULL
7200 * is if we exit, and since we're currently in the middle of
7201 * a fork we can't be exiting at the same time.
7205 * Lock the parent list. No need to lock the child - not PID
7206 * hashed yet and not running, so nobody can access it.
7208 mutex_lock(&parent_ctx
->mutex
);
7211 * We dont have to disable NMIs - we are only looking at
7212 * the list, not manipulating it:
7214 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
7215 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7216 child
, ctxn
, &inherited_all
);
7222 * We can't hold ctx->lock when iterating the ->flexible_group list due
7223 * to allocations, but we need to prevent rotation because
7224 * rotate_ctx() will change the list from interrupt context.
7226 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7227 parent_ctx
->rotate_disable
= 1;
7228 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7230 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
7231 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7232 child
, ctxn
, &inherited_all
);
7237 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7238 parent_ctx
->rotate_disable
= 0;
7240 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7242 if (child_ctx
&& inherited_all
) {
7244 * Mark the child context as a clone of the parent
7245 * context, or of whatever the parent is a clone of.
7247 * Note that if the parent is a clone, the holding of
7248 * parent_ctx->lock avoids it from being uncloned.
7250 cloned_ctx
= parent_ctx
->parent_ctx
;
7252 child_ctx
->parent_ctx
= cloned_ctx
;
7253 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
7255 child_ctx
->parent_ctx
= parent_ctx
;
7256 child_ctx
->parent_gen
= parent_ctx
->generation
;
7258 get_ctx(child_ctx
->parent_ctx
);
7261 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7262 mutex_unlock(&parent_ctx
->mutex
);
7264 perf_unpin_context(parent_ctx
);
7265 put_ctx(parent_ctx
);
7271 * Initialize the perf_event context in task_struct
7273 int perf_event_init_task(struct task_struct
*child
)
7277 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7278 mutex_init(&child
->perf_event_mutex
);
7279 INIT_LIST_HEAD(&child
->perf_event_list
);
7281 for_each_task_context_nr(ctxn
) {
7282 ret
= perf_event_init_context(child
, ctxn
);
7290 static void __init
perf_event_init_all_cpus(void)
7292 struct swevent_htable
*swhash
;
7295 for_each_possible_cpu(cpu
) {
7296 swhash
= &per_cpu(swevent_htable
, cpu
);
7297 mutex_init(&swhash
->hlist_mutex
);
7298 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7302 static void __cpuinit
perf_event_init_cpu(int cpu
)
7304 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7306 mutex_lock(&swhash
->hlist_mutex
);
7307 if (swhash
->hlist_refcount
> 0) {
7308 struct swevent_hlist
*hlist
;
7310 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7312 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7314 mutex_unlock(&swhash
->hlist_mutex
);
7317 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7318 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7320 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7322 WARN_ON(!irqs_disabled());
7324 list_del_init(&cpuctx
->rotation_list
);
7327 static void __perf_event_exit_context(void *__info
)
7329 struct perf_event_context
*ctx
= __info
;
7330 struct perf_event
*event
, *tmp
;
7332 perf_pmu_rotate_stop(ctx
->pmu
);
7334 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
7335 __perf_remove_from_context(event
);
7336 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
7337 __perf_remove_from_context(event
);
7340 static void perf_event_exit_cpu_context(int cpu
)
7342 struct perf_event_context
*ctx
;
7346 idx
= srcu_read_lock(&pmus_srcu
);
7347 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7348 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
7350 mutex_lock(&ctx
->mutex
);
7351 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
7352 mutex_unlock(&ctx
->mutex
);
7354 srcu_read_unlock(&pmus_srcu
, idx
);
7357 static void perf_event_exit_cpu(int cpu
)
7359 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7361 mutex_lock(&swhash
->hlist_mutex
);
7362 swevent_hlist_release(swhash
);
7363 mutex_unlock(&swhash
->hlist_mutex
);
7365 perf_event_exit_cpu_context(cpu
);
7368 static inline void perf_event_exit_cpu(int cpu
) { }
7372 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
7376 for_each_online_cpu(cpu
)
7377 perf_event_exit_cpu(cpu
);
7383 * Run the perf reboot notifier at the very last possible moment so that
7384 * the generic watchdog code runs as long as possible.
7386 static struct notifier_block perf_reboot_notifier
= {
7387 .notifier_call
= perf_reboot
,
7388 .priority
= INT_MIN
,
7391 static int __cpuinit
7392 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
7394 unsigned int cpu
= (long)hcpu
;
7396 switch (action
& ~CPU_TASKS_FROZEN
) {
7398 case CPU_UP_PREPARE
:
7399 case CPU_DOWN_FAILED
:
7400 perf_event_init_cpu(cpu
);
7403 case CPU_UP_CANCELED
:
7404 case CPU_DOWN_PREPARE
:
7405 perf_event_exit_cpu(cpu
);
7415 void __init
perf_event_init(void)
7421 perf_event_init_all_cpus();
7422 init_srcu_struct(&pmus_srcu
);
7423 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
7424 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
7425 perf_pmu_register(&perf_task_clock
, NULL
, -1);
7427 perf_cpu_notifier(perf_cpu_notify
);
7428 register_reboot_notifier(&perf_reboot_notifier
);
7430 ret
= init_hw_breakpoint();
7431 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
7433 /* do not patch jump label more than once per second */
7434 jump_label_rate_limit(&perf_sched_events
, HZ
);
7437 * Build time assertion that we keep the data_head at the intended
7438 * location. IOW, validation we got the __reserved[] size right.
7440 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
7444 static int __init
perf_event_sysfs_init(void)
7449 mutex_lock(&pmus_lock
);
7451 ret
= bus_register(&pmu_bus
);
7455 list_for_each_entry(pmu
, &pmus
, entry
) {
7456 if (!pmu
->name
|| pmu
->type
< 0)
7459 ret
= pmu_dev_alloc(pmu
);
7460 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
7462 pmu_bus_running
= 1;
7466 mutex_unlock(&pmus_lock
);
7470 device_initcall(perf_event_sysfs_init
);
7472 #ifdef CONFIG_CGROUP_PERF
7473 static struct cgroup_subsys_state
*perf_cgroup_css_alloc(struct cgroup
*cont
)
7475 struct perf_cgroup
*jc
;
7477 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
7479 return ERR_PTR(-ENOMEM
);
7481 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
7484 return ERR_PTR(-ENOMEM
);
7490 static void perf_cgroup_css_free(struct cgroup
*cont
)
7492 struct perf_cgroup
*jc
;
7493 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
7494 struct perf_cgroup
, css
);
7495 free_percpu(jc
->info
);
7499 static int __perf_cgroup_move(void *info
)
7501 struct task_struct
*task
= info
;
7502 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
7506 static void perf_cgroup_attach(struct cgroup
*cgrp
, struct cgroup_taskset
*tset
)
7508 struct task_struct
*task
;
7510 cgroup_taskset_for_each(task
, cgrp
, tset
)
7511 task_function_call(task
, __perf_cgroup_move
, task
);
7514 static void perf_cgroup_exit(struct cgroup
*cgrp
, struct cgroup
*old_cgrp
,
7515 struct task_struct
*task
)
7518 * cgroup_exit() is called in the copy_process() failure path.
7519 * Ignore this case since the task hasn't ran yet, this avoids
7520 * trying to poke a half freed task state from generic code.
7522 if (!(task
->flags
& PF_EXITING
))
7525 task_function_call(task
, __perf_cgroup_move
, task
);
7528 struct cgroup_subsys perf_subsys
= {
7529 .name
= "perf_event",
7530 .subsys_id
= perf_subsys_id
,
7531 .css_alloc
= perf_cgroup_css_alloc
,
7532 .css_free
= perf_cgroup_css_free
,
7533 .exit
= perf_cgroup_exit
,
7534 .attach
= perf_cgroup_attach
,
7536 #endif /* CONFIG_CGROUP_PERF */