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/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/perf_event.h>
38 #include <linux/ftrace_event.h>
39 #include <linux/hw_breakpoint.h>
40 #include <linux/mm_types.h>
41 #include <linux/cgroup.h>
45 #include <asm/irq_regs.h>
47 struct remote_function_call
{
48 struct task_struct
*p
;
49 int (*func
)(void *info
);
54 static void remote_function(void *data
)
56 struct remote_function_call
*tfc
= data
;
57 struct task_struct
*p
= tfc
->p
;
61 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
65 tfc
->ret
= tfc
->func(tfc
->info
);
69 * task_function_call - call a function on the cpu on which a task runs
70 * @p: the task to evaluate
71 * @func: the function to be called
72 * @info: the function call argument
74 * Calls the function @func when the task is currently running. This might
75 * be on the current CPU, which just calls the function directly
77 * returns: @func return value, or
78 * -ESRCH - when the process isn't running
79 * -EAGAIN - when the process moved away
82 task_function_call(struct task_struct
*p
, int (*func
) (void *info
), void *info
)
84 struct remote_function_call data
= {
88 .ret
= -ESRCH
, /* No such (running) process */
92 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
98 * cpu_function_call - call a function on the cpu
99 * @func: the function to be called
100 * @info: the function call argument
102 * Calls the function @func on the remote cpu.
104 * returns: @func return value or -ENXIO when the cpu is offline
106 static int cpu_function_call(int cpu
, int (*func
) (void *info
), void *info
)
108 struct remote_function_call data
= {
112 .ret
= -ENXIO
, /* No such CPU */
115 smp_call_function_single(cpu
, remote_function
, &data
, 1);
120 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
121 PERF_FLAG_FD_OUTPUT |\
122 PERF_FLAG_PID_CGROUP)
125 * branch priv levels that need permission checks
127 #define PERF_SAMPLE_BRANCH_PERM_PLM \
128 (PERF_SAMPLE_BRANCH_KERNEL |\
129 PERF_SAMPLE_BRANCH_HV)
132 EVENT_FLEXIBLE
= 0x1,
134 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
138 * perf_sched_events : >0 events exist
139 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
141 struct static_key_deferred perf_sched_events __read_mostly
;
142 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
143 static DEFINE_PER_CPU(atomic_t
, perf_branch_stack_events
);
145 static atomic_t nr_mmap_events __read_mostly
;
146 static atomic_t nr_comm_events __read_mostly
;
147 static atomic_t nr_task_events __read_mostly
;
149 static LIST_HEAD(pmus
);
150 static DEFINE_MUTEX(pmus_lock
);
151 static struct srcu_struct pmus_srcu
;
154 * perf event paranoia level:
155 * -1 - not paranoid at all
156 * 0 - disallow raw tracepoint access for unpriv
157 * 1 - disallow cpu events for unpriv
158 * 2 - disallow kernel profiling for unpriv
160 int sysctl_perf_event_paranoid __read_mostly
= 1;
162 /* Minimum for 512 kiB + 1 user control page */
163 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
166 * max perf event sample rate
168 #define DEFAULT_MAX_SAMPLE_RATE 100000
169 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
170 static int max_samples_per_tick __read_mostly
=
171 DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
173 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
174 void __user
*buffer
, size_t *lenp
,
177 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
182 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
187 static atomic64_t perf_event_id
;
189 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
190 enum event_type_t event_type
);
192 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
193 enum event_type_t event_type
,
194 struct task_struct
*task
);
196 static void update_context_time(struct perf_event_context
*ctx
);
197 static u64
perf_event_time(struct perf_event
*event
);
199 static void ring_buffer_attach(struct perf_event
*event
,
200 struct ring_buffer
*rb
);
202 void __weak
perf_event_print_debug(void) { }
204 extern __weak
const char *perf_pmu_name(void)
209 static inline u64
perf_clock(void)
211 return local_clock();
214 static inline struct perf_cpu_context
*
215 __get_cpu_context(struct perf_event_context
*ctx
)
217 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
220 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
221 struct perf_event_context
*ctx
)
223 raw_spin_lock(&cpuctx
->ctx
.lock
);
225 raw_spin_lock(&ctx
->lock
);
228 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
229 struct perf_event_context
*ctx
)
232 raw_spin_unlock(&ctx
->lock
);
233 raw_spin_unlock(&cpuctx
->ctx
.lock
);
236 #ifdef CONFIG_CGROUP_PERF
239 * perf_cgroup_info keeps track of time_enabled for a cgroup.
240 * This is a per-cpu dynamically allocated data structure.
242 struct perf_cgroup_info
{
248 struct cgroup_subsys_state css
;
249 struct perf_cgroup_info __percpu
*info
;
253 * Must ensure cgroup is pinned (css_get) before calling
254 * this function. In other words, we cannot call this function
255 * if there is no cgroup event for the current CPU context.
257 static inline struct perf_cgroup
*
258 perf_cgroup_from_task(struct task_struct
*task
)
260 return container_of(task_subsys_state(task
, perf_subsys_id
),
261 struct perf_cgroup
, css
);
265 perf_cgroup_match(struct perf_event
*event
)
267 struct perf_event_context
*ctx
= event
->ctx
;
268 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
270 /* @event doesn't care about cgroup */
274 /* wants specific cgroup scope but @cpuctx isn't associated with any */
279 * Cgroup scoping is recursive. An event enabled for a cgroup is
280 * also enabled for all its descendant cgroups. If @cpuctx's
281 * cgroup is a descendant of @event's (the test covers identity
282 * case), it's a match.
284 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
285 event
->cgrp
->css
.cgroup
);
288 static inline bool perf_tryget_cgroup(struct perf_event
*event
)
290 return css_tryget(&event
->cgrp
->css
);
293 static inline void perf_put_cgroup(struct perf_event
*event
)
295 css_put(&event
->cgrp
->css
);
298 static inline void perf_detach_cgroup(struct perf_event
*event
)
300 perf_put_cgroup(event
);
304 static inline int is_cgroup_event(struct perf_event
*event
)
306 return event
->cgrp
!= NULL
;
309 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
311 struct perf_cgroup_info
*t
;
313 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
317 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
319 struct perf_cgroup_info
*info
;
324 info
= this_cpu_ptr(cgrp
->info
);
326 info
->time
+= now
- info
->timestamp
;
327 info
->timestamp
= now
;
330 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
332 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
334 __update_cgrp_time(cgrp_out
);
337 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
339 struct perf_cgroup
*cgrp
;
342 * ensure we access cgroup data only when needed and
343 * when we know the cgroup is pinned (css_get)
345 if (!is_cgroup_event(event
))
348 cgrp
= perf_cgroup_from_task(current
);
350 * Do not update time when cgroup is not active
352 if (cgrp
== event
->cgrp
)
353 __update_cgrp_time(event
->cgrp
);
357 perf_cgroup_set_timestamp(struct task_struct
*task
,
358 struct perf_event_context
*ctx
)
360 struct perf_cgroup
*cgrp
;
361 struct perf_cgroup_info
*info
;
364 * ctx->lock held by caller
365 * ensure we do not access cgroup data
366 * unless we have the cgroup pinned (css_get)
368 if (!task
|| !ctx
->nr_cgroups
)
371 cgrp
= perf_cgroup_from_task(task
);
372 info
= this_cpu_ptr(cgrp
->info
);
373 info
->timestamp
= ctx
->timestamp
;
376 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
377 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
380 * reschedule events based on the cgroup constraint of task.
382 * mode SWOUT : schedule out everything
383 * mode SWIN : schedule in based on cgroup for next
385 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
387 struct perf_cpu_context
*cpuctx
;
392 * disable interrupts to avoid geting nr_cgroup
393 * changes via __perf_event_disable(). Also
396 local_irq_save(flags
);
399 * we reschedule only in the presence of cgroup
400 * constrained events.
404 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
405 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
406 if (cpuctx
->unique_pmu
!= pmu
)
407 continue; /* ensure we process each cpuctx once */
410 * perf_cgroup_events says at least one
411 * context on this CPU has cgroup events.
413 * ctx->nr_cgroups reports the number of cgroup
414 * events for a context.
416 if (cpuctx
->ctx
.nr_cgroups
> 0) {
417 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
418 perf_pmu_disable(cpuctx
->ctx
.pmu
);
420 if (mode
& PERF_CGROUP_SWOUT
) {
421 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
423 * must not be done before ctxswout due
424 * to event_filter_match() in event_sched_out()
429 if (mode
& PERF_CGROUP_SWIN
) {
430 WARN_ON_ONCE(cpuctx
->cgrp
);
432 * set cgrp before ctxsw in to allow
433 * event_filter_match() to not have to pass
436 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
437 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
439 perf_pmu_enable(cpuctx
->ctx
.pmu
);
440 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
446 local_irq_restore(flags
);
449 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
450 struct task_struct
*next
)
452 struct perf_cgroup
*cgrp1
;
453 struct perf_cgroup
*cgrp2
= NULL
;
456 * we come here when we know perf_cgroup_events > 0
458 cgrp1
= perf_cgroup_from_task(task
);
461 * next is NULL when called from perf_event_enable_on_exec()
462 * that will systematically cause a cgroup_switch()
465 cgrp2
= perf_cgroup_from_task(next
);
468 * only schedule out current cgroup events if we know
469 * that we are switching to a different cgroup. Otherwise,
470 * do no touch the cgroup events.
473 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
476 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
477 struct task_struct
*task
)
479 struct perf_cgroup
*cgrp1
;
480 struct perf_cgroup
*cgrp2
= NULL
;
483 * we come here when we know perf_cgroup_events > 0
485 cgrp1
= perf_cgroup_from_task(task
);
487 /* prev can never be NULL */
488 cgrp2
= perf_cgroup_from_task(prev
);
491 * only need to schedule in cgroup events if we are changing
492 * cgroup during ctxsw. Cgroup events were not scheduled
493 * out of ctxsw out if that was not the case.
496 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
499 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
500 struct perf_event_attr
*attr
,
501 struct perf_event
*group_leader
)
503 struct perf_cgroup
*cgrp
;
504 struct cgroup_subsys_state
*css
;
505 struct fd f
= fdget(fd
);
511 css
= cgroup_css_from_dir(f
.file
, perf_subsys_id
);
517 cgrp
= container_of(css
, struct perf_cgroup
, css
);
520 /* must be done before we fput() the file */
521 if (!perf_tryget_cgroup(event
)) {
528 * all events in a group must monitor
529 * the same cgroup because a task belongs
530 * to only one perf cgroup at a time
532 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
533 perf_detach_cgroup(event
);
542 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
544 struct perf_cgroup_info
*t
;
545 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
546 event
->shadow_ctx_time
= now
- t
->timestamp
;
550 perf_cgroup_defer_enabled(struct perf_event
*event
)
553 * when the current task's perf cgroup does not match
554 * the event's, we need to remember to call the
555 * perf_mark_enable() function the first time a task with
556 * a matching perf cgroup is scheduled in.
558 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
559 event
->cgrp_defer_enabled
= 1;
563 perf_cgroup_mark_enabled(struct perf_event
*event
,
564 struct perf_event_context
*ctx
)
566 struct perf_event
*sub
;
567 u64 tstamp
= perf_event_time(event
);
569 if (!event
->cgrp_defer_enabled
)
572 event
->cgrp_defer_enabled
= 0;
574 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
575 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
576 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
577 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
578 sub
->cgrp_defer_enabled
= 0;
582 #else /* !CONFIG_CGROUP_PERF */
585 perf_cgroup_match(struct perf_event
*event
)
590 static inline void perf_detach_cgroup(struct perf_event
*event
)
593 static inline int is_cgroup_event(struct perf_event
*event
)
598 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
603 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
607 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
611 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
612 struct task_struct
*next
)
616 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
617 struct task_struct
*task
)
621 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
622 struct perf_event_attr
*attr
,
623 struct perf_event
*group_leader
)
629 perf_cgroup_set_timestamp(struct task_struct
*task
,
630 struct perf_event_context
*ctx
)
635 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
640 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
644 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
650 perf_cgroup_defer_enabled(struct perf_event
*event
)
655 perf_cgroup_mark_enabled(struct perf_event
*event
,
656 struct perf_event_context
*ctx
)
661 void perf_pmu_disable(struct pmu
*pmu
)
663 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
665 pmu
->pmu_disable(pmu
);
668 void perf_pmu_enable(struct pmu
*pmu
)
670 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
672 pmu
->pmu_enable(pmu
);
675 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
678 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
679 * because they're strictly cpu affine and rotate_start is called with IRQs
680 * disabled, while rotate_context is called from IRQ context.
682 static void perf_pmu_rotate_start(struct pmu
*pmu
)
684 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
685 struct list_head
*head
= &__get_cpu_var(rotation_list
);
687 WARN_ON(!irqs_disabled());
689 if (list_empty(&cpuctx
->rotation_list
)) {
690 int was_empty
= list_empty(head
);
691 list_add(&cpuctx
->rotation_list
, head
);
693 tick_nohz_full_kick();
697 static void get_ctx(struct perf_event_context
*ctx
)
699 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
702 static void put_ctx(struct perf_event_context
*ctx
)
704 if (atomic_dec_and_test(&ctx
->refcount
)) {
706 put_ctx(ctx
->parent_ctx
);
708 put_task_struct(ctx
->task
);
709 kfree_rcu(ctx
, rcu_head
);
713 static void unclone_ctx(struct perf_event_context
*ctx
)
715 if (ctx
->parent_ctx
) {
716 put_ctx(ctx
->parent_ctx
);
717 ctx
->parent_ctx
= NULL
;
721 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
724 * only top level events have the pid namespace they were created in
727 event
= event
->parent
;
729 return task_tgid_nr_ns(p
, event
->ns
);
732 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
735 * only top level events have the pid namespace they were created in
738 event
= event
->parent
;
740 return task_pid_nr_ns(p
, event
->ns
);
744 * If we inherit events we want to return the parent event id
747 static u64
primary_event_id(struct perf_event
*event
)
752 id
= event
->parent
->id
;
758 * Get the perf_event_context for a task and lock it.
759 * This has to cope with with the fact that until it is locked,
760 * the context could get moved to another task.
762 static struct perf_event_context
*
763 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
765 struct perf_event_context
*ctx
;
769 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
772 * If this context is a clone of another, it might
773 * get swapped for another underneath us by
774 * perf_event_task_sched_out, though the
775 * rcu_read_lock() protects us from any context
776 * getting freed. Lock the context and check if it
777 * got swapped before we could get the lock, and retry
778 * if so. If we locked the right context, then it
779 * can't get swapped on us any more.
781 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
782 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
783 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
787 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
788 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
797 * Get the context for a task and increment its pin_count so it
798 * can't get swapped to another task. This also increments its
799 * reference count so that the context can't get freed.
801 static struct perf_event_context
*
802 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
804 struct perf_event_context
*ctx
;
807 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
810 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
815 static void perf_unpin_context(struct perf_event_context
*ctx
)
819 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
821 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
825 * Update the record of the current time in a context.
827 static void update_context_time(struct perf_event_context
*ctx
)
829 u64 now
= perf_clock();
831 ctx
->time
+= now
- ctx
->timestamp
;
832 ctx
->timestamp
= now
;
835 static u64
perf_event_time(struct perf_event
*event
)
837 struct perf_event_context
*ctx
= event
->ctx
;
839 if (is_cgroup_event(event
))
840 return perf_cgroup_event_time(event
);
842 return ctx
? ctx
->time
: 0;
846 * Update the total_time_enabled and total_time_running fields for a event.
847 * The caller of this function needs to hold the ctx->lock.
849 static void update_event_times(struct perf_event
*event
)
851 struct perf_event_context
*ctx
= event
->ctx
;
854 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
855 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
858 * in cgroup mode, time_enabled represents
859 * the time the event was enabled AND active
860 * tasks were in the monitored cgroup. This is
861 * independent of the activity of the context as
862 * there may be a mix of cgroup and non-cgroup events.
864 * That is why we treat cgroup events differently
867 if (is_cgroup_event(event
))
868 run_end
= perf_cgroup_event_time(event
);
869 else if (ctx
->is_active
)
872 run_end
= event
->tstamp_stopped
;
874 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
876 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
877 run_end
= event
->tstamp_stopped
;
879 run_end
= perf_event_time(event
);
881 event
->total_time_running
= run_end
- event
->tstamp_running
;
886 * Update total_time_enabled and total_time_running for all events in a group.
888 static void update_group_times(struct perf_event
*leader
)
890 struct perf_event
*event
;
892 update_event_times(leader
);
893 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
894 update_event_times(event
);
897 static struct list_head
*
898 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
900 if (event
->attr
.pinned
)
901 return &ctx
->pinned_groups
;
903 return &ctx
->flexible_groups
;
907 * Add a event from the lists for its context.
908 * Must be called with ctx->mutex and ctx->lock held.
911 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
913 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
914 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
917 * If we're a stand alone event or group leader, we go to the context
918 * list, group events are kept attached to the group so that
919 * perf_group_detach can, at all times, locate all siblings.
921 if (event
->group_leader
== event
) {
922 struct list_head
*list
;
924 if (is_software_event(event
))
925 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
927 list
= ctx_group_list(event
, ctx
);
928 list_add_tail(&event
->group_entry
, list
);
931 if (is_cgroup_event(event
))
934 if (has_branch_stack(event
))
935 ctx
->nr_branch_stack
++;
937 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
939 perf_pmu_rotate_start(ctx
->pmu
);
941 if (event
->attr
.inherit_stat
)
946 * Initialize event state based on the perf_event_attr::disabled.
948 static inline void perf_event__state_init(struct perf_event
*event
)
950 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
951 PERF_EVENT_STATE_INACTIVE
;
955 * Called at perf_event creation and when events are attached/detached from a
958 static void perf_event__read_size(struct perf_event
*event
)
960 int entry
= sizeof(u64
); /* value */
964 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
967 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
970 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
971 entry
+= sizeof(u64
);
973 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
974 nr
+= event
->group_leader
->nr_siblings
;
979 event
->read_size
= size
;
982 static void perf_event__header_size(struct perf_event
*event
)
984 struct perf_sample_data
*data
;
985 u64 sample_type
= event
->attr
.sample_type
;
988 perf_event__read_size(event
);
990 if (sample_type
& PERF_SAMPLE_IP
)
991 size
+= sizeof(data
->ip
);
993 if (sample_type
& PERF_SAMPLE_ADDR
)
994 size
+= sizeof(data
->addr
);
996 if (sample_type
& PERF_SAMPLE_PERIOD
)
997 size
+= sizeof(data
->period
);
999 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1000 size
+= sizeof(data
->weight
);
1002 if (sample_type
& PERF_SAMPLE_READ
)
1003 size
+= event
->read_size
;
1005 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1006 size
+= sizeof(data
->data_src
.val
);
1008 event
->header_size
= size
;
1011 static void perf_event__id_header_size(struct perf_event
*event
)
1013 struct perf_sample_data
*data
;
1014 u64 sample_type
= event
->attr
.sample_type
;
1017 if (sample_type
& PERF_SAMPLE_TID
)
1018 size
+= sizeof(data
->tid_entry
);
1020 if (sample_type
& PERF_SAMPLE_TIME
)
1021 size
+= sizeof(data
->time
);
1023 if (sample_type
& PERF_SAMPLE_ID
)
1024 size
+= sizeof(data
->id
);
1026 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1027 size
+= sizeof(data
->stream_id
);
1029 if (sample_type
& PERF_SAMPLE_CPU
)
1030 size
+= sizeof(data
->cpu_entry
);
1032 event
->id_header_size
= size
;
1035 static void perf_group_attach(struct perf_event
*event
)
1037 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1040 * We can have double attach due to group movement in perf_event_open.
1042 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1045 event
->attach_state
|= PERF_ATTACH_GROUP
;
1047 if (group_leader
== event
)
1050 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1051 !is_software_event(event
))
1052 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1054 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1055 group_leader
->nr_siblings
++;
1057 perf_event__header_size(group_leader
);
1059 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1060 perf_event__header_size(pos
);
1064 * Remove a event from the lists for its context.
1065 * Must be called with ctx->mutex and ctx->lock held.
1068 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1070 struct perf_cpu_context
*cpuctx
;
1072 * We can have double detach due to exit/hot-unplug + close.
1074 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1077 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1079 if (is_cgroup_event(event
)) {
1081 cpuctx
= __get_cpu_context(ctx
);
1083 * if there are no more cgroup events
1084 * then cler cgrp to avoid stale pointer
1085 * in update_cgrp_time_from_cpuctx()
1087 if (!ctx
->nr_cgroups
)
1088 cpuctx
->cgrp
= NULL
;
1091 if (has_branch_stack(event
))
1092 ctx
->nr_branch_stack
--;
1095 if (event
->attr
.inherit_stat
)
1098 list_del_rcu(&event
->event_entry
);
1100 if (event
->group_leader
== event
)
1101 list_del_init(&event
->group_entry
);
1103 update_group_times(event
);
1106 * If event was in error state, then keep it
1107 * that way, otherwise bogus counts will be
1108 * returned on read(). The only way to get out
1109 * of error state is by explicit re-enabling
1112 if (event
->state
> PERF_EVENT_STATE_OFF
)
1113 event
->state
= PERF_EVENT_STATE_OFF
;
1116 static void perf_group_detach(struct perf_event
*event
)
1118 struct perf_event
*sibling
, *tmp
;
1119 struct list_head
*list
= NULL
;
1122 * We can have double detach due to exit/hot-unplug + close.
1124 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1127 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1130 * If this is a sibling, remove it from its group.
1132 if (event
->group_leader
!= event
) {
1133 list_del_init(&event
->group_entry
);
1134 event
->group_leader
->nr_siblings
--;
1138 if (!list_empty(&event
->group_entry
))
1139 list
= &event
->group_entry
;
1142 * If this was a group event with sibling events then
1143 * upgrade the siblings to singleton events by adding them
1144 * to whatever list we are on.
1146 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1148 list_move_tail(&sibling
->group_entry
, list
);
1149 sibling
->group_leader
= sibling
;
1151 /* Inherit group flags from the previous leader */
1152 sibling
->group_flags
= event
->group_flags
;
1156 perf_event__header_size(event
->group_leader
);
1158 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1159 perf_event__header_size(tmp
);
1163 event_filter_match(struct perf_event
*event
)
1165 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1166 && perf_cgroup_match(event
);
1170 event_sched_out(struct perf_event
*event
,
1171 struct perf_cpu_context
*cpuctx
,
1172 struct perf_event_context
*ctx
)
1174 u64 tstamp
= perf_event_time(event
);
1177 * An event which could not be activated because of
1178 * filter mismatch still needs to have its timings
1179 * maintained, otherwise bogus information is return
1180 * via read() for time_enabled, time_running:
1182 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1183 && !event_filter_match(event
)) {
1184 delta
= tstamp
- event
->tstamp_stopped
;
1185 event
->tstamp_running
+= delta
;
1186 event
->tstamp_stopped
= tstamp
;
1189 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1192 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1193 if (event
->pending_disable
) {
1194 event
->pending_disable
= 0;
1195 event
->state
= PERF_EVENT_STATE_OFF
;
1197 event
->tstamp_stopped
= tstamp
;
1198 event
->pmu
->del(event
, 0);
1201 if (!is_software_event(event
))
1202 cpuctx
->active_oncpu
--;
1204 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1206 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1207 cpuctx
->exclusive
= 0;
1211 group_sched_out(struct perf_event
*group_event
,
1212 struct perf_cpu_context
*cpuctx
,
1213 struct perf_event_context
*ctx
)
1215 struct perf_event
*event
;
1216 int state
= group_event
->state
;
1218 event_sched_out(group_event
, cpuctx
, ctx
);
1221 * Schedule out siblings (if any):
1223 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1224 event_sched_out(event
, cpuctx
, ctx
);
1226 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1227 cpuctx
->exclusive
= 0;
1231 * Cross CPU call to remove a performance event
1233 * We disable the event on the hardware level first. After that we
1234 * remove it from the context list.
1236 static int __perf_remove_from_context(void *info
)
1238 struct perf_event
*event
= info
;
1239 struct perf_event_context
*ctx
= event
->ctx
;
1240 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1242 raw_spin_lock(&ctx
->lock
);
1243 event_sched_out(event
, cpuctx
, ctx
);
1244 list_del_event(event
, ctx
);
1245 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1247 cpuctx
->task_ctx
= NULL
;
1249 raw_spin_unlock(&ctx
->lock
);
1256 * Remove the event from a task's (or a CPU's) list of events.
1258 * CPU events are removed with a smp call. For task events we only
1259 * call when the task is on a CPU.
1261 * If event->ctx is a cloned context, callers must make sure that
1262 * every task struct that event->ctx->task could possibly point to
1263 * remains valid. This is OK when called from perf_release since
1264 * that only calls us on the top-level context, which can't be a clone.
1265 * When called from perf_event_exit_task, it's OK because the
1266 * context has been detached from its task.
1268 static void perf_remove_from_context(struct perf_event
*event
)
1270 struct perf_event_context
*ctx
= event
->ctx
;
1271 struct task_struct
*task
= ctx
->task
;
1273 lockdep_assert_held(&ctx
->mutex
);
1277 * Per cpu events are removed via an smp call and
1278 * the removal is always successful.
1280 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1285 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1288 raw_spin_lock_irq(&ctx
->lock
);
1290 * If we failed to find a running task, but find the context active now
1291 * that we've acquired the ctx->lock, retry.
1293 if (ctx
->is_active
) {
1294 raw_spin_unlock_irq(&ctx
->lock
);
1299 * Since the task isn't running, its safe to remove the event, us
1300 * holding the ctx->lock ensures the task won't get scheduled in.
1302 list_del_event(event
, ctx
);
1303 raw_spin_unlock_irq(&ctx
->lock
);
1307 * Cross CPU call to disable a performance event
1309 int __perf_event_disable(void *info
)
1311 struct perf_event
*event
= info
;
1312 struct perf_event_context
*ctx
= event
->ctx
;
1313 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1316 * If this is a per-task event, need to check whether this
1317 * event's task is the current task on this cpu.
1319 * Can trigger due to concurrent perf_event_context_sched_out()
1320 * flipping contexts around.
1322 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1325 raw_spin_lock(&ctx
->lock
);
1328 * If the event is on, turn it off.
1329 * If it is in error state, leave it in error state.
1331 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1332 update_context_time(ctx
);
1333 update_cgrp_time_from_event(event
);
1334 update_group_times(event
);
1335 if (event
== event
->group_leader
)
1336 group_sched_out(event
, cpuctx
, ctx
);
1338 event_sched_out(event
, cpuctx
, ctx
);
1339 event
->state
= PERF_EVENT_STATE_OFF
;
1342 raw_spin_unlock(&ctx
->lock
);
1350 * If event->ctx is a cloned context, callers must make sure that
1351 * every task struct that event->ctx->task could possibly point to
1352 * remains valid. This condition is satisifed when called through
1353 * perf_event_for_each_child or perf_event_for_each because they
1354 * hold the top-level event's child_mutex, so any descendant that
1355 * goes to exit will block in sync_child_event.
1356 * When called from perf_pending_event it's OK because event->ctx
1357 * is the current context on this CPU and preemption is disabled,
1358 * hence we can't get into perf_event_task_sched_out for this context.
1360 void perf_event_disable(struct perf_event
*event
)
1362 struct perf_event_context
*ctx
= event
->ctx
;
1363 struct task_struct
*task
= ctx
->task
;
1367 * Disable the event on the cpu that it's on
1369 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1374 if (!task_function_call(task
, __perf_event_disable
, event
))
1377 raw_spin_lock_irq(&ctx
->lock
);
1379 * If the event is still active, we need to retry the cross-call.
1381 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1382 raw_spin_unlock_irq(&ctx
->lock
);
1384 * Reload the task pointer, it might have been changed by
1385 * a concurrent perf_event_context_sched_out().
1392 * Since we have the lock this context can't be scheduled
1393 * in, so we can change the state safely.
1395 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1396 update_group_times(event
);
1397 event
->state
= PERF_EVENT_STATE_OFF
;
1399 raw_spin_unlock_irq(&ctx
->lock
);
1401 EXPORT_SYMBOL_GPL(perf_event_disable
);
1403 static void perf_set_shadow_time(struct perf_event
*event
,
1404 struct perf_event_context
*ctx
,
1408 * use the correct time source for the time snapshot
1410 * We could get by without this by leveraging the
1411 * fact that to get to this function, the caller
1412 * has most likely already called update_context_time()
1413 * and update_cgrp_time_xx() and thus both timestamp
1414 * are identical (or very close). Given that tstamp is,
1415 * already adjusted for cgroup, we could say that:
1416 * tstamp - ctx->timestamp
1418 * tstamp - cgrp->timestamp.
1420 * Then, in perf_output_read(), the calculation would
1421 * work with no changes because:
1422 * - event is guaranteed scheduled in
1423 * - no scheduled out in between
1424 * - thus the timestamp would be the same
1426 * But this is a bit hairy.
1428 * So instead, we have an explicit cgroup call to remain
1429 * within the time time source all along. We believe it
1430 * is cleaner and simpler to understand.
1432 if (is_cgroup_event(event
))
1433 perf_cgroup_set_shadow_time(event
, tstamp
);
1435 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1438 #define MAX_INTERRUPTS (~0ULL)
1440 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1443 event_sched_in(struct perf_event
*event
,
1444 struct perf_cpu_context
*cpuctx
,
1445 struct perf_event_context
*ctx
)
1447 u64 tstamp
= perf_event_time(event
);
1449 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1452 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1453 event
->oncpu
= smp_processor_id();
1456 * Unthrottle events, since we scheduled we might have missed several
1457 * ticks already, also for a heavily scheduling task there is little
1458 * guarantee it'll get a tick in a timely manner.
1460 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1461 perf_log_throttle(event
, 1);
1462 event
->hw
.interrupts
= 0;
1466 * The new state must be visible before we turn it on in the hardware:
1470 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1471 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1476 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1478 perf_set_shadow_time(event
, ctx
, tstamp
);
1480 if (!is_software_event(event
))
1481 cpuctx
->active_oncpu
++;
1483 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1486 if (event
->attr
.exclusive
)
1487 cpuctx
->exclusive
= 1;
1493 group_sched_in(struct perf_event
*group_event
,
1494 struct perf_cpu_context
*cpuctx
,
1495 struct perf_event_context
*ctx
)
1497 struct perf_event
*event
, *partial_group
= NULL
;
1498 struct pmu
*pmu
= group_event
->pmu
;
1499 u64 now
= ctx
->time
;
1500 bool simulate
= false;
1502 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1505 pmu
->start_txn(pmu
);
1507 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1508 pmu
->cancel_txn(pmu
);
1513 * Schedule in siblings as one group (if any):
1515 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1516 if (event_sched_in(event
, cpuctx
, ctx
)) {
1517 partial_group
= event
;
1522 if (!pmu
->commit_txn(pmu
))
1527 * Groups can be scheduled in as one unit only, so undo any
1528 * partial group before returning:
1529 * The events up to the failed event are scheduled out normally,
1530 * tstamp_stopped will be updated.
1532 * The failed events and the remaining siblings need to have
1533 * their timings updated as if they had gone thru event_sched_in()
1534 * and event_sched_out(). This is required to get consistent timings
1535 * across the group. This also takes care of the case where the group
1536 * could never be scheduled by ensuring tstamp_stopped is set to mark
1537 * the time the event was actually stopped, such that time delta
1538 * calculation in update_event_times() is correct.
1540 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1541 if (event
== partial_group
)
1545 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1546 event
->tstamp_stopped
= now
;
1548 event_sched_out(event
, cpuctx
, ctx
);
1551 event_sched_out(group_event
, cpuctx
, ctx
);
1553 pmu
->cancel_txn(pmu
);
1559 * Work out whether we can put this event group on the CPU now.
1561 static int group_can_go_on(struct perf_event
*event
,
1562 struct perf_cpu_context
*cpuctx
,
1566 * Groups consisting entirely of software events can always go on.
1568 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1571 * If an exclusive group is already on, no other hardware
1574 if (cpuctx
->exclusive
)
1577 * If this group is exclusive and there are already
1578 * events on the CPU, it can't go on.
1580 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1583 * Otherwise, try to add it if all previous groups were able
1589 static void add_event_to_ctx(struct perf_event
*event
,
1590 struct perf_event_context
*ctx
)
1592 u64 tstamp
= perf_event_time(event
);
1594 list_add_event(event
, ctx
);
1595 perf_group_attach(event
);
1596 event
->tstamp_enabled
= tstamp
;
1597 event
->tstamp_running
= tstamp
;
1598 event
->tstamp_stopped
= tstamp
;
1601 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
1603 ctx_sched_in(struct perf_event_context
*ctx
,
1604 struct perf_cpu_context
*cpuctx
,
1605 enum event_type_t event_type
,
1606 struct task_struct
*task
);
1608 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
1609 struct perf_event_context
*ctx
,
1610 struct task_struct
*task
)
1612 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
1614 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
1615 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
1617 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
1621 * Cross CPU call to install and enable a performance event
1623 * Must be called with ctx->mutex held
1625 static int __perf_install_in_context(void *info
)
1627 struct perf_event
*event
= info
;
1628 struct perf_event_context
*ctx
= event
->ctx
;
1629 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1630 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
1631 struct task_struct
*task
= current
;
1633 perf_ctx_lock(cpuctx
, task_ctx
);
1634 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1637 * If there was an active task_ctx schedule it out.
1640 task_ctx_sched_out(task_ctx
);
1643 * If the context we're installing events in is not the
1644 * active task_ctx, flip them.
1646 if (ctx
->task
&& task_ctx
!= ctx
) {
1648 raw_spin_unlock(&task_ctx
->lock
);
1649 raw_spin_lock(&ctx
->lock
);
1654 cpuctx
->task_ctx
= task_ctx
;
1655 task
= task_ctx
->task
;
1658 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
1660 update_context_time(ctx
);
1662 * update cgrp time only if current cgrp
1663 * matches event->cgrp. Must be done before
1664 * calling add_event_to_ctx()
1666 update_cgrp_time_from_event(event
);
1668 add_event_to_ctx(event
, ctx
);
1671 * Schedule everything back in
1673 perf_event_sched_in(cpuctx
, task_ctx
, task
);
1675 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1676 perf_ctx_unlock(cpuctx
, task_ctx
);
1682 * Attach a performance event to a context
1684 * First we add the event to the list with the hardware enable bit
1685 * in event->hw_config cleared.
1687 * If the event is attached to a task which is on a CPU we use a smp
1688 * call to enable it in the task context. The task might have been
1689 * scheduled away, but we check this in the smp call again.
1692 perf_install_in_context(struct perf_event_context
*ctx
,
1693 struct perf_event
*event
,
1696 struct task_struct
*task
= ctx
->task
;
1698 lockdep_assert_held(&ctx
->mutex
);
1701 if (event
->cpu
!= -1)
1706 * Per cpu events are installed via an smp call and
1707 * the install is always successful.
1709 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1714 if (!task_function_call(task
, __perf_install_in_context
, event
))
1717 raw_spin_lock_irq(&ctx
->lock
);
1719 * If we failed to find a running task, but find the context active now
1720 * that we've acquired the ctx->lock, retry.
1722 if (ctx
->is_active
) {
1723 raw_spin_unlock_irq(&ctx
->lock
);
1728 * Since the task isn't running, its safe to add the event, us holding
1729 * the ctx->lock ensures the task won't get scheduled in.
1731 add_event_to_ctx(event
, ctx
);
1732 raw_spin_unlock_irq(&ctx
->lock
);
1736 * Put a event into inactive state and update time fields.
1737 * Enabling the leader of a group effectively enables all
1738 * the group members that aren't explicitly disabled, so we
1739 * have to update their ->tstamp_enabled also.
1740 * Note: this works for group members as well as group leaders
1741 * since the non-leader members' sibling_lists will be empty.
1743 static void __perf_event_mark_enabled(struct perf_event
*event
)
1745 struct perf_event
*sub
;
1746 u64 tstamp
= perf_event_time(event
);
1748 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1749 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1750 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1751 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1752 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1757 * Cross CPU call to enable a performance event
1759 static int __perf_event_enable(void *info
)
1761 struct perf_event
*event
= info
;
1762 struct perf_event_context
*ctx
= event
->ctx
;
1763 struct perf_event
*leader
= event
->group_leader
;
1764 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1767 if (WARN_ON_ONCE(!ctx
->is_active
))
1770 raw_spin_lock(&ctx
->lock
);
1771 update_context_time(ctx
);
1773 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1777 * set current task's cgroup time reference point
1779 perf_cgroup_set_timestamp(current
, ctx
);
1781 __perf_event_mark_enabled(event
);
1783 if (!event_filter_match(event
)) {
1784 if (is_cgroup_event(event
))
1785 perf_cgroup_defer_enabled(event
);
1790 * If the event is in a group and isn't the group leader,
1791 * then don't put it on unless the group is on.
1793 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1796 if (!group_can_go_on(event
, cpuctx
, 1)) {
1799 if (event
== leader
)
1800 err
= group_sched_in(event
, cpuctx
, ctx
);
1802 err
= event_sched_in(event
, cpuctx
, ctx
);
1807 * If this event can't go on and it's part of a
1808 * group, then the whole group has to come off.
1810 if (leader
!= event
)
1811 group_sched_out(leader
, cpuctx
, ctx
);
1812 if (leader
->attr
.pinned
) {
1813 update_group_times(leader
);
1814 leader
->state
= PERF_EVENT_STATE_ERROR
;
1819 raw_spin_unlock(&ctx
->lock
);
1827 * If event->ctx is a cloned context, callers must make sure that
1828 * every task struct that event->ctx->task could possibly point to
1829 * remains valid. This condition is satisfied when called through
1830 * perf_event_for_each_child or perf_event_for_each as described
1831 * for perf_event_disable.
1833 void perf_event_enable(struct perf_event
*event
)
1835 struct perf_event_context
*ctx
= event
->ctx
;
1836 struct task_struct
*task
= ctx
->task
;
1840 * Enable the event on the cpu that it's on
1842 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
1846 raw_spin_lock_irq(&ctx
->lock
);
1847 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1851 * If the event is in error state, clear that first.
1852 * That way, if we see the event in error state below, we
1853 * know that it has gone back into error state, as distinct
1854 * from the task having been scheduled away before the
1855 * cross-call arrived.
1857 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1858 event
->state
= PERF_EVENT_STATE_OFF
;
1861 if (!ctx
->is_active
) {
1862 __perf_event_mark_enabled(event
);
1866 raw_spin_unlock_irq(&ctx
->lock
);
1868 if (!task_function_call(task
, __perf_event_enable
, event
))
1871 raw_spin_lock_irq(&ctx
->lock
);
1874 * If the context is active and the event is still off,
1875 * we need to retry the cross-call.
1877 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
1879 * task could have been flipped by a concurrent
1880 * perf_event_context_sched_out()
1887 raw_spin_unlock_irq(&ctx
->lock
);
1889 EXPORT_SYMBOL_GPL(perf_event_enable
);
1891 int perf_event_refresh(struct perf_event
*event
, int refresh
)
1894 * not supported on inherited events
1896 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1899 atomic_add(refresh
, &event
->event_limit
);
1900 perf_event_enable(event
);
1904 EXPORT_SYMBOL_GPL(perf_event_refresh
);
1906 static void ctx_sched_out(struct perf_event_context
*ctx
,
1907 struct perf_cpu_context
*cpuctx
,
1908 enum event_type_t event_type
)
1910 struct perf_event
*event
;
1911 int is_active
= ctx
->is_active
;
1913 ctx
->is_active
&= ~event_type
;
1914 if (likely(!ctx
->nr_events
))
1917 update_context_time(ctx
);
1918 update_cgrp_time_from_cpuctx(cpuctx
);
1919 if (!ctx
->nr_active
)
1922 perf_pmu_disable(ctx
->pmu
);
1923 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
1924 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1925 group_sched_out(event
, cpuctx
, ctx
);
1928 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
1929 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1930 group_sched_out(event
, cpuctx
, ctx
);
1932 perf_pmu_enable(ctx
->pmu
);
1936 * Test whether two contexts are equivalent, i.e. whether they
1937 * have both been cloned from the same version of the same context
1938 * and they both have the same number of enabled events.
1939 * If the number of enabled events is the same, then the set
1940 * of enabled events should be the same, because these are both
1941 * inherited contexts, therefore we can't access individual events
1942 * in them directly with an fd; we can only enable/disable all
1943 * events via prctl, or enable/disable all events in a family
1944 * via ioctl, which will have the same effect on both contexts.
1946 static int context_equiv(struct perf_event_context
*ctx1
,
1947 struct perf_event_context
*ctx2
)
1949 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1950 && ctx1
->parent_gen
== ctx2
->parent_gen
1951 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1954 static void __perf_event_sync_stat(struct perf_event
*event
,
1955 struct perf_event
*next_event
)
1959 if (!event
->attr
.inherit_stat
)
1963 * Update the event value, we cannot use perf_event_read()
1964 * because we're in the middle of a context switch and have IRQs
1965 * disabled, which upsets smp_call_function_single(), however
1966 * we know the event must be on the current CPU, therefore we
1967 * don't need to use it.
1969 switch (event
->state
) {
1970 case PERF_EVENT_STATE_ACTIVE
:
1971 event
->pmu
->read(event
);
1974 case PERF_EVENT_STATE_INACTIVE
:
1975 update_event_times(event
);
1983 * In order to keep per-task stats reliable we need to flip the event
1984 * values when we flip the contexts.
1986 value
= local64_read(&next_event
->count
);
1987 value
= local64_xchg(&event
->count
, value
);
1988 local64_set(&next_event
->count
, value
);
1990 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1991 swap(event
->total_time_running
, next_event
->total_time_running
);
1994 * Since we swizzled the values, update the user visible data too.
1996 perf_event_update_userpage(event
);
1997 perf_event_update_userpage(next_event
);
2000 #define list_next_entry(pos, member) \
2001 list_entry(pos->member.next, typeof(*pos), member)
2003 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2004 struct perf_event_context
*next_ctx
)
2006 struct perf_event
*event
, *next_event
;
2011 update_context_time(ctx
);
2013 event
= list_first_entry(&ctx
->event_list
,
2014 struct perf_event
, event_entry
);
2016 next_event
= list_first_entry(&next_ctx
->event_list
,
2017 struct perf_event
, event_entry
);
2019 while (&event
->event_entry
!= &ctx
->event_list
&&
2020 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2022 __perf_event_sync_stat(event
, next_event
);
2024 event
= list_next_entry(event
, event_entry
);
2025 next_event
= list_next_entry(next_event
, event_entry
);
2029 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2030 struct task_struct
*next
)
2032 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2033 struct perf_event_context
*next_ctx
;
2034 struct perf_event_context
*parent
;
2035 struct perf_cpu_context
*cpuctx
;
2041 cpuctx
= __get_cpu_context(ctx
);
2042 if (!cpuctx
->task_ctx
)
2046 parent
= rcu_dereference(ctx
->parent_ctx
);
2047 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2048 if (parent
&& next_ctx
&&
2049 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
2051 * Looks like the two contexts are clones, so we might be
2052 * able to optimize the context switch. We lock both
2053 * contexts and check that they are clones under the
2054 * lock (including re-checking that neither has been
2055 * uncloned in the meantime). It doesn't matter which
2056 * order we take the locks because no other cpu could
2057 * be trying to lock both of these tasks.
2059 raw_spin_lock(&ctx
->lock
);
2060 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2061 if (context_equiv(ctx
, next_ctx
)) {
2063 * XXX do we need a memory barrier of sorts
2064 * wrt to rcu_dereference() of perf_event_ctxp
2066 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2067 next
->perf_event_ctxp
[ctxn
] = ctx
;
2069 next_ctx
->task
= task
;
2072 perf_event_sync_stat(ctx
, next_ctx
);
2074 raw_spin_unlock(&next_ctx
->lock
);
2075 raw_spin_unlock(&ctx
->lock
);
2080 raw_spin_lock(&ctx
->lock
);
2081 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2082 cpuctx
->task_ctx
= NULL
;
2083 raw_spin_unlock(&ctx
->lock
);
2087 #define for_each_task_context_nr(ctxn) \
2088 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2091 * Called from scheduler to remove the events of the current task,
2092 * with interrupts disabled.
2094 * We stop each event and update the event value in event->count.
2096 * This does not protect us against NMI, but disable()
2097 * sets the disabled bit in the control field of event _before_
2098 * accessing the event control register. If a NMI hits, then it will
2099 * not restart the event.
2101 void __perf_event_task_sched_out(struct task_struct
*task
,
2102 struct task_struct
*next
)
2106 for_each_task_context_nr(ctxn
)
2107 perf_event_context_sched_out(task
, ctxn
, next
);
2110 * if cgroup events exist on this CPU, then we need
2111 * to check if we have to switch out PMU state.
2112 * cgroup event are system-wide mode only
2114 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2115 perf_cgroup_sched_out(task
, next
);
2118 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2120 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2122 if (!cpuctx
->task_ctx
)
2125 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2128 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2129 cpuctx
->task_ctx
= NULL
;
2133 * Called with IRQs disabled
2135 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2136 enum event_type_t event_type
)
2138 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2142 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2143 struct perf_cpu_context
*cpuctx
)
2145 struct perf_event
*event
;
2147 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2148 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2150 if (!event_filter_match(event
))
2153 /* may need to reset tstamp_enabled */
2154 if (is_cgroup_event(event
))
2155 perf_cgroup_mark_enabled(event
, ctx
);
2157 if (group_can_go_on(event
, cpuctx
, 1))
2158 group_sched_in(event
, cpuctx
, ctx
);
2161 * If this pinned group hasn't been scheduled,
2162 * put it in error state.
2164 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2165 update_group_times(event
);
2166 event
->state
= PERF_EVENT_STATE_ERROR
;
2172 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2173 struct perf_cpu_context
*cpuctx
)
2175 struct perf_event
*event
;
2178 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2179 /* Ignore events in OFF or ERROR state */
2180 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2183 * Listen to the 'cpu' scheduling filter constraint
2186 if (!event_filter_match(event
))
2189 /* may need to reset tstamp_enabled */
2190 if (is_cgroup_event(event
))
2191 perf_cgroup_mark_enabled(event
, ctx
);
2193 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2194 if (group_sched_in(event
, cpuctx
, ctx
))
2201 ctx_sched_in(struct perf_event_context
*ctx
,
2202 struct perf_cpu_context
*cpuctx
,
2203 enum event_type_t event_type
,
2204 struct task_struct
*task
)
2207 int is_active
= ctx
->is_active
;
2209 ctx
->is_active
|= event_type
;
2210 if (likely(!ctx
->nr_events
))
2214 ctx
->timestamp
= now
;
2215 perf_cgroup_set_timestamp(task
, ctx
);
2217 * First go through the list and put on any pinned groups
2218 * in order to give them the best chance of going on.
2220 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2221 ctx_pinned_sched_in(ctx
, cpuctx
);
2223 /* Then walk through the lower prio flexible groups */
2224 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2225 ctx_flexible_sched_in(ctx
, cpuctx
);
2228 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2229 enum event_type_t event_type
,
2230 struct task_struct
*task
)
2232 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2234 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2237 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2238 struct task_struct
*task
)
2240 struct perf_cpu_context
*cpuctx
;
2242 cpuctx
= __get_cpu_context(ctx
);
2243 if (cpuctx
->task_ctx
== ctx
)
2246 perf_ctx_lock(cpuctx
, ctx
);
2247 perf_pmu_disable(ctx
->pmu
);
2249 * We want to keep the following priority order:
2250 * cpu pinned (that don't need to move), task pinned,
2251 * cpu flexible, task flexible.
2253 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2256 cpuctx
->task_ctx
= ctx
;
2258 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2260 perf_pmu_enable(ctx
->pmu
);
2261 perf_ctx_unlock(cpuctx
, ctx
);
2264 * Since these rotations are per-cpu, we need to ensure the
2265 * cpu-context we got scheduled on is actually rotating.
2267 perf_pmu_rotate_start(ctx
->pmu
);
2271 * When sampling the branck stack in system-wide, it may be necessary
2272 * to flush the stack on context switch. This happens when the branch
2273 * stack does not tag its entries with the pid of the current task.
2274 * Otherwise it becomes impossible to associate a branch entry with a
2275 * task. This ambiguity is more likely to appear when the branch stack
2276 * supports priv level filtering and the user sets it to monitor only
2277 * at the user level (which could be a useful measurement in system-wide
2278 * mode). In that case, the risk is high of having a branch stack with
2279 * branch from multiple tasks. Flushing may mean dropping the existing
2280 * entries or stashing them somewhere in the PMU specific code layer.
2282 * This function provides the context switch callback to the lower code
2283 * layer. It is invoked ONLY when there is at least one system-wide context
2284 * with at least one active event using taken branch sampling.
2286 static void perf_branch_stack_sched_in(struct task_struct
*prev
,
2287 struct task_struct
*task
)
2289 struct perf_cpu_context
*cpuctx
;
2291 unsigned long flags
;
2293 /* no need to flush branch stack if not changing task */
2297 local_irq_save(flags
);
2301 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2302 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2305 * check if the context has at least one
2306 * event using PERF_SAMPLE_BRANCH_STACK
2308 if (cpuctx
->ctx
.nr_branch_stack
> 0
2309 && pmu
->flush_branch_stack
) {
2311 pmu
= cpuctx
->ctx
.pmu
;
2313 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2315 perf_pmu_disable(pmu
);
2317 pmu
->flush_branch_stack();
2319 perf_pmu_enable(pmu
);
2321 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2327 local_irq_restore(flags
);
2331 * Called from scheduler to add the events of the current task
2332 * with interrupts disabled.
2334 * We restore the event value and then enable it.
2336 * This does not protect us against NMI, but enable()
2337 * sets the enabled bit in the control field of event _before_
2338 * accessing the event control register. If a NMI hits, then it will
2339 * keep the event running.
2341 void __perf_event_task_sched_in(struct task_struct
*prev
,
2342 struct task_struct
*task
)
2344 struct perf_event_context
*ctx
;
2347 for_each_task_context_nr(ctxn
) {
2348 ctx
= task
->perf_event_ctxp
[ctxn
];
2352 perf_event_context_sched_in(ctx
, task
);
2355 * if cgroup events exist on this CPU, then we need
2356 * to check if we have to switch in PMU state.
2357 * cgroup event are system-wide mode only
2359 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2360 perf_cgroup_sched_in(prev
, task
);
2362 /* check for system-wide branch_stack events */
2363 if (atomic_read(&__get_cpu_var(perf_branch_stack_events
)))
2364 perf_branch_stack_sched_in(prev
, task
);
2367 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2369 u64 frequency
= event
->attr
.sample_freq
;
2370 u64 sec
= NSEC_PER_SEC
;
2371 u64 divisor
, dividend
;
2373 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2375 count_fls
= fls64(count
);
2376 nsec_fls
= fls64(nsec
);
2377 frequency_fls
= fls64(frequency
);
2381 * We got @count in @nsec, with a target of sample_freq HZ
2382 * the target period becomes:
2385 * period = -------------------
2386 * @nsec * sample_freq
2391 * Reduce accuracy by one bit such that @a and @b converge
2392 * to a similar magnitude.
2394 #define REDUCE_FLS(a, b) \
2396 if (a##_fls > b##_fls) { \
2406 * Reduce accuracy until either term fits in a u64, then proceed with
2407 * the other, so that finally we can do a u64/u64 division.
2409 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2410 REDUCE_FLS(nsec
, frequency
);
2411 REDUCE_FLS(sec
, count
);
2414 if (count_fls
+ sec_fls
> 64) {
2415 divisor
= nsec
* frequency
;
2417 while (count_fls
+ sec_fls
> 64) {
2418 REDUCE_FLS(count
, sec
);
2422 dividend
= count
* sec
;
2424 dividend
= count
* sec
;
2426 while (nsec_fls
+ frequency_fls
> 64) {
2427 REDUCE_FLS(nsec
, frequency
);
2431 divisor
= nsec
* frequency
;
2437 return div64_u64(dividend
, divisor
);
2440 static DEFINE_PER_CPU(int, perf_throttled_count
);
2441 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2443 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2445 struct hw_perf_event
*hwc
= &event
->hw
;
2446 s64 period
, sample_period
;
2449 period
= perf_calculate_period(event
, nsec
, count
);
2451 delta
= (s64
)(period
- hwc
->sample_period
);
2452 delta
= (delta
+ 7) / 8; /* low pass filter */
2454 sample_period
= hwc
->sample_period
+ delta
;
2459 hwc
->sample_period
= sample_period
;
2461 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2463 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2465 local64_set(&hwc
->period_left
, 0);
2468 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2473 * combine freq adjustment with unthrottling to avoid two passes over the
2474 * events. At the same time, make sure, having freq events does not change
2475 * the rate of unthrottling as that would introduce bias.
2477 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2480 struct perf_event
*event
;
2481 struct hw_perf_event
*hwc
;
2482 u64 now
, period
= TICK_NSEC
;
2486 * only need to iterate over all events iff:
2487 * - context have events in frequency mode (needs freq adjust)
2488 * - there are events to unthrottle on this cpu
2490 if (!(ctx
->nr_freq
|| needs_unthr
))
2493 raw_spin_lock(&ctx
->lock
);
2494 perf_pmu_disable(ctx
->pmu
);
2496 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2497 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2500 if (!event_filter_match(event
))
2505 if (needs_unthr
&& hwc
->interrupts
== MAX_INTERRUPTS
) {
2506 hwc
->interrupts
= 0;
2507 perf_log_throttle(event
, 1);
2508 event
->pmu
->start(event
, 0);
2511 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2515 * stop the event and update event->count
2517 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2519 now
= local64_read(&event
->count
);
2520 delta
= now
- hwc
->freq_count_stamp
;
2521 hwc
->freq_count_stamp
= now
;
2525 * reload only if value has changed
2526 * we have stopped the event so tell that
2527 * to perf_adjust_period() to avoid stopping it
2531 perf_adjust_period(event
, period
, delta
, false);
2533 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
2536 perf_pmu_enable(ctx
->pmu
);
2537 raw_spin_unlock(&ctx
->lock
);
2541 * Round-robin a context's events:
2543 static void rotate_ctx(struct perf_event_context
*ctx
)
2546 * Rotate the first entry last of non-pinned groups. Rotation might be
2547 * disabled by the inheritance code.
2549 if (!ctx
->rotate_disable
)
2550 list_rotate_left(&ctx
->flexible_groups
);
2554 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2555 * because they're strictly cpu affine and rotate_start is called with IRQs
2556 * disabled, while rotate_context is called from IRQ context.
2558 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2560 struct perf_event_context
*ctx
= NULL
;
2561 int rotate
= 0, remove
= 1;
2563 if (cpuctx
->ctx
.nr_events
) {
2565 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2569 ctx
= cpuctx
->task_ctx
;
2570 if (ctx
&& ctx
->nr_events
) {
2572 if (ctx
->nr_events
!= ctx
->nr_active
)
2579 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2580 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2582 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2584 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
2586 rotate_ctx(&cpuctx
->ctx
);
2590 perf_event_sched_in(cpuctx
, ctx
, current
);
2592 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2593 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2596 list_del_init(&cpuctx
->rotation_list
);
2599 #ifdef CONFIG_NO_HZ_FULL
2600 bool perf_event_can_stop_tick(void)
2602 if (list_empty(&__get_cpu_var(rotation_list
)))
2609 void perf_event_task_tick(void)
2611 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2612 struct perf_cpu_context
*cpuctx
, *tmp
;
2613 struct perf_event_context
*ctx
;
2616 WARN_ON(!irqs_disabled());
2618 __this_cpu_inc(perf_throttled_seq
);
2619 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
2621 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2623 perf_adjust_freq_unthr_context(ctx
, throttled
);
2625 ctx
= cpuctx
->task_ctx
;
2627 perf_adjust_freq_unthr_context(ctx
, throttled
);
2629 if (cpuctx
->jiffies_interval
== 1 ||
2630 !(jiffies
% cpuctx
->jiffies_interval
))
2631 perf_rotate_context(cpuctx
);
2635 static int event_enable_on_exec(struct perf_event
*event
,
2636 struct perf_event_context
*ctx
)
2638 if (!event
->attr
.enable_on_exec
)
2641 event
->attr
.enable_on_exec
= 0;
2642 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2645 __perf_event_mark_enabled(event
);
2651 * Enable all of a task's events that have been marked enable-on-exec.
2652 * This expects task == current.
2654 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2656 struct perf_event
*event
;
2657 unsigned long flags
;
2661 local_irq_save(flags
);
2662 if (!ctx
|| !ctx
->nr_events
)
2666 * We must ctxsw out cgroup events to avoid conflict
2667 * when invoking perf_task_event_sched_in() later on
2668 * in this function. Otherwise we end up trying to
2669 * ctxswin cgroup events which are already scheduled
2672 perf_cgroup_sched_out(current
, NULL
);
2674 raw_spin_lock(&ctx
->lock
);
2675 task_ctx_sched_out(ctx
);
2677 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
2678 ret
= event_enable_on_exec(event
, ctx
);
2684 * Unclone this context if we enabled any event.
2689 raw_spin_unlock(&ctx
->lock
);
2692 * Also calls ctxswin for cgroup events, if any:
2694 perf_event_context_sched_in(ctx
, ctx
->task
);
2696 local_irq_restore(flags
);
2700 * Cross CPU call to read the hardware event
2702 static void __perf_event_read(void *info
)
2704 struct perf_event
*event
= info
;
2705 struct perf_event_context
*ctx
= event
->ctx
;
2706 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2709 * If this is a task context, we need to check whether it is
2710 * the current task context of this cpu. If not it has been
2711 * scheduled out before the smp call arrived. In that case
2712 * event->count would have been updated to a recent sample
2713 * when the event was scheduled out.
2715 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2718 raw_spin_lock(&ctx
->lock
);
2719 if (ctx
->is_active
) {
2720 update_context_time(ctx
);
2721 update_cgrp_time_from_event(event
);
2723 update_event_times(event
);
2724 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2725 event
->pmu
->read(event
);
2726 raw_spin_unlock(&ctx
->lock
);
2729 static inline u64
perf_event_count(struct perf_event
*event
)
2731 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2734 static u64
perf_event_read(struct perf_event
*event
)
2737 * If event is enabled and currently active on a CPU, update the
2738 * value in the event structure:
2740 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2741 smp_call_function_single(event
->oncpu
,
2742 __perf_event_read
, event
, 1);
2743 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2744 struct perf_event_context
*ctx
= event
->ctx
;
2745 unsigned long flags
;
2747 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2749 * may read while context is not active
2750 * (e.g., thread is blocked), in that case
2751 * we cannot update context time
2753 if (ctx
->is_active
) {
2754 update_context_time(ctx
);
2755 update_cgrp_time_from_event(event
);
2757 update_event_times(event
);
2758 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2761 return perf_event_count(event
);
2765 * Initialize the perf_event context in a task_struct:
2767 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2769 raw_spin_lock_init(&ctx
->lock
);
2770 mutex_init(&ctx
->mutex
);
2771 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2772 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2773 INIT_LIST_HEAD(&ctx
->event_list
);
2774 atomic_set(&ctx
->refcount
, 1);
2777 static struct perf_event_context
*
2778 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2780 struct perf_event_context
*ctx
;
2782 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2786 __perf_event_init_context(ctx
);
2789 get_task_struct(task
);
2796 static struct task_struct
*
2797 find_lively_task_by_vpid(pid_t vpid
)
2799 struct task_struct
*task
;
2806 task
= find_task_by_vpid(vpid
);
2808 get_task_struct(task
);
2812 return ERR_PTR(-ESRCH
);
2814 /* Reuse ptrace permission checks for now. */
2816 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2821 put_task_struct(task
);
2822 return ERR_PTR(err
);
2827 * Returns a matching context with refcount and pincount.
2829 static struct perf_event_context
*
2830 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2832 struct perf_event_context
*ctx
;
2833 struct perf_cpu_context
*cpuctx
;
2834 unsigned long flags
;
2838 /* Must be root to operate on a CPU event: */
2839 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2840 return ERR_PTR(-EACCES
);
2843 * We could be clever and allow to attach a event to an
2844 * offline CPU and activate it when the CPU comes up, but
2847 if (!cpu_online(cpu
))
2848 return ERR_PTR(-ENODEV
);
2850 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2859 ctxn
= pmu
->task_ctx_nr
;
2864 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2868 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2870 ctx
= alloc_perf_context(pmu
, task
);
2876 mutex_lock(&task
->perf_event_mutex
);
2878 * If it has already passed perf_event_exit_task().
2879 * we must see PF_EXITING, it takes this mutex too.
2881 if (task
->flags
& PF_EXITING
)
2883 else if (task
->perf_event_ctxp
[ctxn
])
2888 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2890 mutex_unlock(&task
->perf_event_mutex
);
2892 if (unlikely(err
)) {
2904 return ERR_PTR(err
);
2907 static void perf_event_free_filter(struct perf_event
*event
);
2909 static void free_event_rcu(struct rcu_head
*head
)
2911 struct perf_event
*event
;
2913 event
= container_of(head
, struct perf_event
, rcu_head
);
2915 put_pid_ns(event
->ns
);
2916 perf_event_free_filter(event
);
2920 static bool ring_buffer_put(struct ring_buffer
*rb
);
2922 static void free_event(struct perf_event
*event
)
2924 irq_work_sync(&event
->pending
);
2926 if (!event
->parent
) {
2927 if (event
->attach_state
& PERF_ATTACH_TASK
)
2928 static_key_slow_dec_deferred(&perf_sched_events
);
2929 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2930 atomic_dec(&nr_mmap_events
);
2931 if (event
->attr
.comm
)
2932 atomic_dec(&nr_comm_events
);
2933 if (event
->attr
.task
)
2934 atomic_dec(&nr_task_events
);
2935 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2936 put_callchain_buffers();
2937 if (is_cgroup_event(event
)) {
2938 atomic_dec(&per_cpu(perf_cgroup_events
, event
->cpu
));
2939 static_key_slow_dec_deferred(&perf_sched_events
);
2942 if (has_branch_stack(event
)) {
2943 static_key_slow_dec_deferred(&perf_sched_events
);
2944 /* is system-wide event */
2945 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
2946 atomic_dec(&per_cpu(perf_branch_stack_events
,
2952 ring_buffer_put(event
->rb
);
2956 if (is_cgroup_event(event
))
2957 perf_detach_cgroup(event
);
2960 event
->destroy(event
);
2963 put_ctx(event
->ctx
);
2965 call_rcu(&event
->rcu_head
, free_event_rcu
);
2968 int perf_event_release_kernel(struct perf_event
*event
)
2970 struct perf_event_context
*ctx
= event
->ctx
;
2972 WARN_ON_ONCE(ctx
->parent_ctx
);
2974 * There are two ways this annotation is useful:
2976 * 1) there is a lock recursion from perf_event_exit_task
2977 * see the comment there.
2979 * 2) there is a lock-inversion with mmap_sem through
2980 * perf_event_read_group(), which takes faults while
2981 * holding ctx->mutex, however this is called after
2982 * the last filedesc died, so there is no possibility
2983 * to trigger the AB-BA case.
2985 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2986 raw_spin_lock_irq(&ctx
->lock
);
2987 perf_group_detach(event
);
2988 raw_spin_unlock_irq(&ctx
->lock
);
2989 perf_remove_from_context(event
);
2990 mutex_unlock(&ctx
->mutex
);
2996 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2999 * Called when the last reference to the file is gone.
3001 static void put_event(struct perf_event
*event
)
3003 struct task_struct
*owner
;
3005 if (!atomic_long_dec_and_test(&event
->refcount
))
3009 owner
= ACCESS_ONCE(event
->owner
);
3011 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3012 * !owner it means the list deletion is complete and we can indeed
3013 * free this event, otherwise we need to serialize on
3014 * owner->perf_event_mutex.
3016 smp_read_barrier_depends();
3019 * Since delayed_put_task_struct() also drops the last
3020 * task reference we can safely take a new reference
3021 * while holding the rcu_read_lock().
3023 get_task_struct(owner
);
3028 mutex_lock(&owner
->perf_event_mutex
);
3030 * We have to re-check the event->owner field, if it is cleared
3031 * we raced with perf_event_exit_task(), acquiring the mutex
3032 * ensured they're done, and we can proceed with freeing the
3036 list_del_init(&event
->owner_entry
);
3037 mutex_unlock(&owner
->perf_event_mutex
);
3038 put_task_struct(owner
);
3041 perf_event_release_kernel(event
);
3044 static int perf_release(struct inode
*inode
, struct file
*file
)
3046 put_event(file
->private_data
);
3050 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3052 struct perf_event
*child
;
3058 mutex_lock(&event
->child_mutex
);
3059 total
+= perf_event_read(event
);
3060 *enabled
+= event
->total_time_enabled
+
3061 atomic64_read(&event
->child_total_time_enabled
);
3062 *running
+= event
->total_time_running
+
3063 atomic64_read(&event
->child_total_time_running
);
3065 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3066 total
+= perf_event_read(child
);
3067 *enabled
+= child
->total_time_enabled
;
3068 *running
+= child
->total_time_running
;
3070 mutex_unlock(&event
->child_mutex
);
3074 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3076 static int perf_event_read_group(struct perf_event
*event
,
3077 u64 read_format
, char __user
*buf
)
3079 struct perf_event
*leader
= event
->group_leader
, *sub
;
3080 int n
= 0, size
= 0, ret
= -EFAULT
;
3081 struct perf_event_context
*ctx
= leader
->ctx
;
3083 u64 count
, enabled
, running
;
3085 mutex_lock(&ctx
->mutex
);
3086 count
= perf_event_read_value(leader
, &enabled
, &running
);
3088 values
[n
++] = 1 + leader
->nr_siblings
;
3089 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3090 values
[n
++] = enabled
;
3091 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3092 values
[n
++] = running
;
3093 values
[n
++] = count
;
3094 if (read_format
& PERF_FORMAT_ID
)
3095 values
[n
++] = primary_event_id(leader
);
3097 size
= n
* sizeof(u64
);
3099 if (copy_to_user(buf
, values
, size
))
3104 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3107 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3108 if (read_format
& PERF_FORMAT_ID
)
3109 values
[n
++] = primary_event_id(sub
);
3111 size
= n
* sizeof(u64
);
3113 if (copy_to_user(buf
+ ret
, values
, size
)) {
3121 mutex_unlock(&ctx
->mutex
);
3126 static int perf_event_read_one(struct perf_event
*event
,
3127 u64 read_format
, char __user
*buf
)
3129 u64 enabled
, running
;
3133 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3134 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3135 values
[n
++] = enabled
;
3136 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3137 values
[n
++] = running
;
3138 if (read_format
& PERF_FORMAT_ID
)
3139 values
[n
++] = primary_event_id(event
);
3141 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3144 return n
* sizeof(u64
);
3148 * Read the performance event - simple non blocking version for now
3151 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3153 u64 read_format
= event
->attr
.read_format
;
3157 * Return end-of-file for a read on a event that is in
3158 * error state (i.e. because it was pinned but it couldn't be
3159 * scheduled on to the CPU at some point).
3161 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3164 if (count
< event
->read_size
)
3167 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3168 if (read_format
& PERF_FORMAT_GROUP
)
3169 ret
= perf_event_read_group(event
, read_format
, buf
);
3171 ret
= perf_event_read_one(event
, read_format
, buf
);
3177 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3179 struct perf_event
*event
= file
->private_data
;
3181 return perf_read_hw(event
, buf
, count
);
3184 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3186 struct perf_event
*event
= file
->private_data
;
3187 struct ring_buffer
*rb
;
3188 unsigned int events
= POLL_HUP
;
3191 * Race between perf_event_set_output() and perf_poll(): perf_poll()
3192 * grabs the rb reference but perf_event_set_output() overrides it.
3193 * Here is the timeline for two threads T1, T2:
3194 * t0: T1, rb = rcu_dereference(event->rb)
3195 * t1: T2, old_rb = event->rb
3196 * t2: T2, event->rb = new rb
3197 * t3: T2, ring_buffer_detach(old_rb)
3198 * t4: T1, ring_buffer_attach(rb1)
3199 * t5: T1, poll_wait(event->waitq)
3201 * To avoid this problem, we grab mmap_mutex in perf_poll()
3202 * thereby ensuring that the assignment of the new ring buffer
3203 * and the detachment of the old buffer appear atomic to perf_poll()
3205 mutex_lock(&event
->mmap_mutex
);
3208 rb
= rcu_dereference(event
->rb
);
3210 ring_buffer_attach(event
, rb
);
3211 events
= atomic_xchg(&rb
->poll
, 0);
3215 mutex_unlock(&event
->mmap_mutex
);
3217 poll_wait(file
, &event
->waitq
, wait
);
3222 static void perf_event_reset(struct perf_event
*event
)
3224 (void)perf_event_read(event
);
3225 local64_set(&event
->count
, 0);
3226 perf_event_update_userpage(event
);
3230 * Holding the top-level event's child_mutex means that any
3231 * descendant process that has inherited this event will block
3232 * in sync_child_event if it goes to exit, thus satisfying the
3233 * task existence requirements of perf_event_enable/disable.
3235 static void perf_event_for_each_child(struct perf_event
*event
,
3236 void (*func
)(struct perf_event
*))
3238 struct perf_event
*child
;
3240 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3241 mutex_lock(&event
->child_mutex
);
3243 list_for_each_entry(child
, &event
->child_list
, child_list
)
3245 mutex_unlock(&event
->child_mutex
);
3248 static void perf_event_for_each(struct perf_event
*event
,
3249 void (*func
)(struct perf_event
*))
3251 struct perf_event_context
*ctx
= event
->ctx
;
3252 struct perf_event
*sibling
;
3254 WARN_ON_ONCE(ctx
->parent_ctx
);
3255 mutex_lock(&ctx
->mutex
);
3256 event
= event
->group_leader
;
3258 perf_event_for_each_child(event
, func
);
3259 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3260 perf_event_for_each_child(sibling
, func
);
3261 mutex_unlock(&ctx
->mutex
);
3264 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3266 struct perf_event_context
*ctx
= event
->ctx
;
3270 if (!is_sampling_event(event
))
3273 if (copy_from_user(&value
, arg
, sizeof(value
)))
3279 raw_spin_lock_irq(&ctx
->lock
);
3280 if (event
->attr
.freq
) {
3281 if (value
> sysctl_perf_event_sample_rate
) {
3286 event
->attr
.sample_freq
= value
;
3288 event
->attr
.sample_period
= value
;
3289 event
->hw
.sample_period
= value
;
3292 raw_spin_unlock_irq(&ctx
->lock
);
3297 static const struct file_operations perf_fops
;
3299 static inline int perf_fget_light(int fd
, struct fd
*p
)
3301 struct fd f
= fdget(fd
);
3305 if (f
.file
->f_op
!= &perf_fops
) {
3313 static int perf_event_set_output(struct perf_event
*event
,
3314 struct perf_event
*output_event
);
3315 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3317 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3319 struct perf_event
*event
= file
->private_data
;
3320 void (*func
)(struct perf_event
*);
3324 case PERF_EVENT_IOC_ENABLE
:
3325 func
= perf_event_enable
;
3327 case PERF_EVENT_IOC_DISABLE
:
3328 func
= perf_event_disable
;
3330 case PERF_EVENT_IOC_RESET
:
3331 func
= perf_event_reset
;
3334 case PERF_EVENT_IOC_REFRESH
:
3335 return perf_event_refresh(event
, arg
);
3337 case PERF_EVENT_IOC_PERIOD
:
3338 return perf_event_period(event
, (u64 __user
*)arg
);
3340 case PERF_EVENT_IOC_SET_OUTPUT
:
3344 struct perf_event
*output_event
;
3346 ret
= perf_fget_light(arg
, &output
);
3349 output_event
= output
.file
->private_data
;
3350 ret
= perf_event_set_output(event
, output_event
);
3353 ret
= perf_event_set_output(event
, NULL
);
3358 case PERF_EVENT_IOC_SET_FILTER
:
3359 return perf_event_set_filter(event
, (void __user
*)arg
);
3365 if (flags
& PERF_IOC_FLAG_GROUP
)
3366 perf_event_for_each(event
, func
);
3368 perf_event_for_each_child(event
, func
);
3373 int perf_event_task_enable(void)
3375 struct perf_event
*event
;
3377 mutex_lock(¤t
->perf_event_mutex
);
3378 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3379 perf_event_for_each_child(event
, perf_event_enable
);
3380 mutex_unlock(¤t
->perf_event_mutex
);
3385 int perf_event_task_disable(void)
3387 struct perf_event
*event
;
3389 mutex_lock(¤t
->perf_event_mutex
);
3390 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3391 perf_event_for_each_child(event
, perf_event_disable
);
3392 mutex_unlock(¤t
->perf_event_mutex
);
3397 static int perf_event_index(struct perf_event
*event
)
3399 if (event
->hw
.state
& PERF_HES_STOPPED
)
3402 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3405 return event
->pmu
->event_idx(event
);
3408 static void calc_timer_values(struct perf_event
*event
,
3415 *now
= perf_clock();
3416 ctx_time
= event
->shadow_ctx_time
+ *now
;
3417 *enabled
= ctx_time
- event
->tstamp_enabled
;
3418 *running
= ctx_time
- event
->tstamp_running
;
3421 void __weak
arch_perf_update_userpage(struct perf_event_mmap_page
*userpg
, u64 now
)
3426 * Callers need to ensure there can be no nesting of this function, otherwise
3427 * the seqlock logic goes bad. We can not serialize this because the arch
3428 * code calls this from NMI context.
3430 void perf_event_update_userpage(struct perf_event
*event
)
3432 struct perf_event_mmap_page
*userpg
;
3433 struct ring_buffer
*rb
;
3434 u64 enabled
, running
, now
;
3438 * compute total_time_enabled, total_time_running
3439 * based on snapshot values taken when the event
3440 * was last scheduled in.
3442 * we cannot simply called update_context_time()
3443 * because of locking issue as we can be called in
3446 calc_timer_values(event
, &now
, &enabled
, &running
);
3447 rb
= rcu_dereference(event
->rb
);
3451 userpg
= rb
->user_page
;
3454 * Disable preemption so as to not let the corresponding user-space
3455 * spin too long if we get preempted.
3460 userpg
->index
= perf_event_index(event
);
3461 userpg
->offset
= perf_event_count(event
);
3463 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3465 userpg
->time_enabled
= enabled
+
3466 atomic64_read(&event
->child_total_time_enabled
);
3468 userpg
->time_running
= running
+
3469 atomic64_read(&event
->child_total_time_running
);
3471 arch_perf_update_userpage(userpg
, now
);
3480 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3482 struct perf_event
*event
= vma
->vm_file
->private_data
;
3483 struct ring_buffer
*rb
;
3484 int ret
= VM_FAULT_SIGBUS
;
3486 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3487 if (vmf
->pgoff
== 0)
3493 rb
= rcu_dereference(event
->rb
);
3497 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3500 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3504 get_page(vmf
->page
);
3505 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3506 vmf
->page
->index
= vmf
->pgoff
;
3515 static void ring_buffer_attach(struct perf_event
*event
,
3516 struct ring_buffer
*rb
)
3518 unsigned long flags
;
3520 if (!list_empty(&event
->rb_entry
))
3523 spin_lock_irqsave(&rb
->event_lock
, flags
);
3524 if (!list_empty(&event
->rb_entry
))
3527 list_add(&event
->rb_entry
, &rb
->event_list
);
3529 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3532 static void ring_buffer_detach(struct perf_event
*event
,
3533 struct ring_buffer
*rb
)
3535 unsigned long flags
;
3537 if (list_empty(&event
->rb_entry
))
3540 spin_lock_irqsave(&rb
->event_lock
, flags
);
3541 list_del_init(&event
->rb_entry
);
3542 wake_up_all(&event
->waitq
);
3543 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3546 static void ring_buffer_wakeup(struct perf_event
*event
)
3548 struct ring_buffer
*rb
;
3551 rb
= rcu_dereference(event
->rb
);
3555 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
3556 wake_up_all(&event
->waitq
);
3562 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3564 struct ring_buffer
*rb
;
3566 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3570 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3572 struct ring_buffer
*rb
;
3575 rb
= rcu_dereference(event
->rb
);
3577 if (!atomic_inc_not_zero(&rb
->refcount
))
3585 static bool ring_buffer_put(struct ring_buffer
*rb
)
3587 struct perf_event
*event
, *n
;
3588 unsigned long flags
;
3590 if (!atomic_dec_and_test(&rb
->refcount
))
3593 spin_lock_irqsave(&rb
->event_lock
, flags
);
3594 list_for_each_entry_safe(event
, n
, &rb
->event_list
, rb_entry
) {
3595 list_del_init(&event
->rb_entry
);
3596 wake_up_all(&event
->waitq
);
3598 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3600 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3604 static void perf_mmap_open(struct vm_area_struct
*vma
)
3606 struct perf_event
*event
= vma
->vm_file
->private_data
;
3608 atomic_inc(&event
->mmap_count
);
3611 static void perf_mmap_close(struct vm_area_struct
*vma
)
3613 struct perf_event
*event
= vma
->vm_file
->private_data
;
3615 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3616 struct ring_buffer
*rb
= event
->rb
;
3617 struct user_struct
*mmap_user
= rb
->mmap_user
;
3618 int mmap_locked
= rb
->mmap_locked
;
3619 unsigned long size
= perf_data_size(rb
);
3621 rcu_assign_pointer(event
->rb
, NULL
);
3622 ring_buffer_detach(event
, rb
);
3623 mutex_unlock(&event
->mmap_mutex
);
3625 if (ring_buffer_put(rb
)) {
3626 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
3627 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
3628 free_uid(mmap_user
);
3633 static const struct vm_operations_struct perf_mmap_vmops
= {
3634 .open
= perf_mmap_open
,
3635 .close
= perf_mmap_close
,
3636 .fault
= perf_mmap_fault
,
3637 .page_mkwrite
= perf_mmap_fault
,
3640 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3642 struct perf_event
*event
= file
->private_data
;
3643 unsigned long user_locked
, user_lock_limit
;
3644 struct user_struct
*user
= current_user();
3645 unsigned long locked
, lock_limit
;
3646 struct ring_buffer
*rb
;
3647 unsigned long vma_size
;
3648 unsigned long nr_pages
;
3649 long user_extra
, extra
;
3650 int ret
= 0, flags
= 0;
3653 * Don't allow mmap() of inherited per-task counters. This would
3654 * create a performance issue due to all children writing to the
3657 if (event
->cpu
== -1 && event
->attr
.inherit
)
3660 if (!(vma
->vm_flags
& VM_SHARED
))
3663 vma_size
= vma
->vm_end
- vma
->vm_start
;
3664 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3667 * If we have rb pages ensure they're a power-of-two number, so we
3668 * can do bitmasks instead of modulo.
3670 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3673 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3676 if (vma
->vm_pgoff
!= 0)
3679 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3680 mutex_lock(&event
->mmap_mutex
);
3682 if (event
->rb
->nr_pages
!= nr_pages
)
3687 user_extra
= nr_pages
+ 1;
3688 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3691 * Increase the limit linearly with more CPUs:
3693 user_lock_limit
*= num_online_cpus();
3695 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3698 if (user_locked
> user_lock_limit
)
3699 extra
= user_locked
- user_lock_limit
;
3701 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3702 lock_limit
>>= PAGE_SHIFT
;
3703 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
3705 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3706 !capable(CAP_IPC_LOCK
)) {
3713 if (vma
->vm_flags
& VM_WRITE
)
3714 flags
|= RING_BUFFER_WRITABLE
;
3716 rb
= rb_alloc(nr_pages
,
3717 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
3725 rb
->mmap_locked
= extra
;
3726 rb
->mmap_user
= get_current_user();
3728 atomic_long_add(user_extra
, &user
->locked_vm
);
3729 vma
->vm_mm
->pinned_vm
+= extra
;
3731 rcu_assign_pointer(event
->rb
, rb
);
3733 perf_event_update_userpage(event
);
3737 atomic_inc(&event
->mmap_count
);
3738 mutex_unlock(&event
->mmap_mutex
);
3740 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
3741 vma
->vm_ops
= &perf_mmap_vmops
;
3746 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3748 struct inode
*inode
= file_inode(filp
);
3749 struct perf_event
*event
= filp
->private_data
;
3752 mutex_lock(&inode
->i_mutex
);
3753 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3754 mutex_unlock(&inode
->i_mutex
);
3762 static const struct file_operations perf_fops
= {
3763 .llseek
= no_llseek
,
3764 .release
= perf_release
,
3767 .unlocked_ioctl
= perf_ioctl
,
3768 .compat_ioctl
= perf_ioctl
,
3770 .fasync
= perf_fasync
,
3776 * If there's data, ensure we set the poll() state and publish everything
3777 * to user-space before waking everybody up.
3780 void perf_event_wakeup(struct perf_event
*event
)
3782 ring_buffer_wakeup(event
);
3784 if (event
->pending_kill
) {
3785 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3786 event
->pending_kill
= 0;
3790 static void perf_pending_event(struct irq_work
*entry
)
3792 struct perf_event
*event
= container_of(entry
,
3793 struct perf_event
, pending
);
3795 if (event
->pending_disable
) {
3796 event
->pending_disable
= 0;
3797 __perf_event_disable(event
);
3800 if (event
->pending_wakeup
) {
3801 event
->pending_wakeup
= 0;
3802 perf_event_wakeup(event
);
3807 * We assume there is only KVM supporting the callbacks.
3808 * Later on, we might change it to a list if there is
3809 * another virtualization implementation supporting the callbacks.
3811 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3813 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3815 perf_guest_cbs
= cbs
;
3818 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3820 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3822 perf_guest_cbs
= NULL
;
3825 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3828 perf_output_sample_regs(struct perf_output_handle
*handle
,
3829 struct pt_regs
*regs
, u64 mask
)
3833 for_each_set_bit(bit
, (const unsigned long *) &mask
,
3834 sizeof(mask
) * BITS_PER_BYTE
) {
3837 val
= perf_reg_value(regs
, bit
);
3838 perf_output_put(handle
, val
);
3842 static void perf_sample_regs_user(struct perf_regs_user
*regs_user
,
3843 struct pt_regs
*regs
)
3845 if (!user_mode(regs
)) {
3847 regs
= task_pt_regs(current
);
3853 regs_user
->regs
= regs
;
3854 regs_user
->abi
= perf_reg_abi(current
);
3859 * Get remaining task size from user stack pointer.
3861 * It'd be better to take stack vma map and limit this more
3862 * precisly, but there's no way to get it safely under interrupt,
3863 * so using TASK_SIZE as limit.
3865 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
3867 unsigned long addr
= perf_user_stack_pointer(regs
);
3869 if (!addr
|| addr
>= TASK_SIZE
)
3872 return TASK_SIZE
- addr
;
3876 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
3877 struct pt_regs
*regs
)
3881 /* No regs, no stack pointer, no dump. */
3886 * Check if we fit in with the requested stack size into the:
3888 * If we don't, we limit the size to the TASK_SIZE.
3890 * - remaining sample size
3891 * If we don't, we customize the stack size to
3892 * fit in to the remaining sample size.
3895 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
3896 stack_size
= min(stack_size
, (u16
) task_size
);
3898 /* Current header size plus static size and dynamic size. */
3899 header_size
+= 2 * sizeof(u64
);
3901 /* Do we fit in with the current stack dump size? */
3902 if ((u16
) (header_size
+ stack_size
) < header_size
) {
3904 * If we overflow the maximum size for the sample,
3905 * we customize the stack dump size to fit in.
3907 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
3908 stack_size
= round_up(stack_size
, sizeof(u64
));
3915 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
3916 struct pt_regs
*regs
)
3918 /* Case of a kernel thread, nothing to dump */
3921 perf_output_put(handle
, size
);
3930 * - the size requested by user or the best one we can fit
3931 * in to the sample max size
3933 * - user stack dump data
3935 * - the actual dumped size
3939 perf_output_put(handle
, dump_size
);
3942 sp
= perf_user_stack_pointer(regs
);
3943 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
3944 dyn_size
= dump_size
- rem
;
3946 perf_output_skip(handle
, rem
);
3949 perf_output_put(handle
, dyn_size
);
3953 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3954 struct perf_sample_data
*data
,
3955 struct perf_event
*event
)
3957 u64 sample_type
= event
->attr
.sample_type
;
3959 data
->type
= sample_type
;
3960 header
->size
+= event
->id_header_size
;
3962 if (sample_type
& PERF_SAMPLE_TID
) {
3963 /* namespace issues */
3964 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3965 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3968 if (sample_type
& PERF_SAMPLE_TIME
)
3969 data
->time
= perf_clock();
3971 if (sample_type
& PERF_SAMPLE_ID
)
3972 data
->id
= primary_event_id(event
);
3974 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3975 data
->stream_id
= event
->id
;
3977 if (sample_type
& PERF_SAMPLE_CPU
) {
3978 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3979 data
->cpu_entry
.reserved
= 0;
3983 void perf_event_header__init_id(struct perf_event_header
*header
,
3984 struct perf_sample_data
*data
,
3985 struct perf_event
*event
)
3987 if (event
->attr
.sample_id_all
)
3988 __perf_event_header__init_id(header
, data
, event
);
3991 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
3992 struct perf_sample_data
*data
)
3994 u64 sample_type
= data
->type
;
3996 if (sample_type
& PERF_SAMPLE_TID
)
3997 perf_output_put(handle
, data
->tid_entry
);
3999 if (sample_type
& PERF_SAMPLE_TIME
)
4000 perf_output_put(handle
, data
->time
);
4002 if (sample_type
& PERF_SAMPLE_ID
)
4003 perf_output_put(handle
, data
->id
);
4005 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4006 perf_output_put(handle
, data
->stream_id
);
4008 if (sample_type
& PERF_SAMPLE_CPU
)
4009 perf_output_put(handle
, data
->cpu_entry
);
4012 void perf_event__output_id_sample(struct perf_event
*event
,
4013 struct perf_output_handle
*handle
,
4014 struct perf_sample_data
*sample
)
4016 if (event
->attr
.sample_id_all
)
4017 __perf_event__output_id_sample(handle
, sample
);
4020 static void perf_output_read_one(struct perf_output_handle
*handle
,
4021 struct perf_event
*event
,
4022 u64 enabled
, u64 running
)
4024 u64 read_format
= event
->attr
.read_format
;
4028 values
[n
++] = perf_event_count(event
);
4029 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4030 values
[n
++] = enabled
+
4031 atomic64_read(&event
->child_total_time_enabled
);
4033 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4034 values
[n
++] = running
+
4035 atomic64_read(&event
->child_total_time_running
);
4037 if (read_format
& PERF_FORMAT_ID
)
4038 values
[n
++] = primary_event_id(event
);
4040 __output_copy(handle
, values
, n
* sizeof(u64
));
4044 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
4046 static void perf_output_read_group(struct perf_output_handle
*handle
,
4047 struct perf_event
*event
,
4048 u64 enabled
, u64 running
)
4050 struct perf_event
*leader
= event
->group_leader
, *sub
;
4051 u64 read_format
= event
->attr
.read_format
;
4055 values
[n
++] = 1 + leader
->nr_siblings
;
4057 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4058 values
[n
++] = enabled
;
4060 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4061 values
[n
++] = running
;
4063 if (leader
!= event
)
4064 leader
->pmu
->read(leader
);
4066 values
[n
++] = perf_event_count(leader
);
4067 if (read_format
& PERF_FORMAT_ID
)
4068 values
[n
++] = primary_event_id(leader
);
4070 __output_copy(handle
, values
, n
* sizeof(u64
));
4072 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4076 sub
->pmu
->read(sub
);
4078 values
[n
++] = perf_event_count(sub
);
4079 if (read_format
& PERF_FORMAT_ID
)
4080 values
[n
++] = primary_event_id(sub
);
4082 __output_copy(handle
, values
, n
* sizeof(u64
));
4086 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
4087 PERF_FORMAT_TOTAL_TIME_RUNNING)
4089 static void perf_output_read(struct perf_output_handle
*handle
,
4090 struct perf_event
*event
)
4092 u64 enabled
= 0, running
= 0, now
;
4093 u64 read_format
= event
->attr
.read_format
;
4096 * compute total_time_enabled, total_time_running
4097 * based on snapshot values taken when the event
4098 * was last scheduled in.
4100 * we cannot simply called update_context_time()
4101 * because of locking issue as we are called in
4104 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
4105 calc_timer_values(event
, &now
, &enabled
, &running
);
4107 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
4108 perf_output_read_group(handle
, event
, enabled
, running
);
4110 perf_output_read_one(handle
, event
, enabled
, running
);
4113 void perf_output_sample(struct perf_output_handle
*handle
,
4114 struct perf_event_header
*header
,
4115 struct perf_sample_data
*data
,
4116 struct perf_event
*event
)
4118 u64 sample_type
= data
->type
;
4120 perf_output_put(handle
, *header
);
4122 if (sample_type
& PERF_SAMPLE_IP
)
4123 perf_output_put(handle
, data
->ip
);
4125 if (sample_type
& PERF_SAMPLE_TID
)
4126 perf_output_put(handle
, data
->tid_entry
);
4128 if (sample_type
& PERF_SAMPLE_TIME
)
4129 perf_output_put(handle
, data
->time
);
4131 if (sample_type
& PERF_SAMPLE_ADDR
)
4132 perf_output_put(handle
, data
->addr
);
4134 if (sample_type
& PERF_SAMPLE_ID
)
4135 perf_output_put(handle
, data
->id
);
4137 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4138 perf_output_put(handle
, data
->stream_id
);
4140 if (sample_type
& PERF_SAMPLE_CPU
)
4141 perf_output_put(handle
, data
->cpu_entry
);
4143 if (sample_type
& PERF_SAMPLE_PERIOD
)
4144 perf_output_put(handle
, data
->period
);
4146 if (sample_type
& PERF_SAMPLE_READ
)
4147 perf_output_read(handle
, event
);
4149 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4150 if (data
->callchain
) {
4153 if (data
->callchain
)
4154 size
+= data
->callchain
->nr
;
4156 size
*= sizeof(u64
);
4158 __output_copy(handle
, data
->callchain
, size
);
4161 perf_output_put(handle
, nr
);
4165 if (sample_type
& PERF_SAMPLE_RAW
) {
4167 perf_output_put(handle
, data
->raw
->size
);
4168 __output_copy(handle
, data
->raw
->data
,
4175 .size
= sizeof(u32
),
4178 perf_output_put(handle
, raw
);
4182 if (!event
->attr
.watermark
) {
4183 int wakeup_events
= event
->attr
.wakeup_events
;
4185 if (wakeup_events
) {
4186 struct ring_buffer
*rb
= handle
->rb
;
4187 int events
= local_inc_return(&rb
->events
);
4189 if (events
>= wakeup_events
) {
4190 local_sub(wakeup_events
, &rb
->events
);
4191 local_inc(&rb
->wakeup
);
4196 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4197 if (data
->br_stack
) {
4200 size
= data
->br_stack
->nr
4201 * sizeof(struct perf_branch_entry
);
4203 perf_output_put(handle
, data
->br_stack
->nr
);
4204 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
4207 * we always store at least the value of nr
4210 perf_output_put(handle
, nr
);
4214 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4215 u64 abi
= data
->regs_user
.abi
;
4218 * If there are no regs to dump, notice it through
4219 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
4221 perf_output_put(handle
, abi
);
4224 u64 mask
= event
->attr
.sample_regs_user
;
4225 perf_output_sample_regs(handle
,
4226 data
->regs_user
.regs
,
4231 if (sample_type
& PERF_SAMPLE_STACK_USER
)
4232 perf_output_sample_ustack(handle
,
4233 data
->stack_user_size
,
4234 data
->regs_user
.regs
);
4236 if (sample_type
& PERF_SAMPLE_WEIGHT
)
4237 perf_output_put(handle
, data
->weight
);
4239 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
4240 perf_output_put(handle
, data
->data_src
.val
);
4243 void perf_prepare_sample(struct perf_event_header
*header
,
4244 struct perf_sample_data
*data
,
4245 struct perf_event
*event
,
4246 struct pt_regs
*regs
)
4248 u64 sample_type
= event
->attr
.sample_type
;
4250 header
->type
= PERF_RECORD_SAMPLE
;
4251 header
->size
= sizeof(*header
) + event
->header_size
;
4254 header
->misc
|= perf_misc_flags(regs
);
4256 __perf_event_header__init_id(header
, data
, event
);
4258 if (sample_type
& PERF_SAMPLE_IP
)
4259 data
->ip
= perf_instruction_pointer(regs
);
4261 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4264 data
->callchain
= perf_callchain(event
, regs
);
4266 if (data
->callchain
)
4267 size
+= data
->callchain
->nr
;
4269 header
->size
+= size
* sizeof(u64
);
4272 if (sample_type
& PERF_SAMPLE_RAW
) {
4273 int size
= sizeof(u32
);
4276 size
+= data
->raw
->size
;
4278 size
+= sizeof(u32
);
4280 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4281 header
->size
+= size
;
4284 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4285 int size
= sizeof(u64
); /* nr */
4286 if (data
->br_stack
) {
4287 size
+= data
->br_stack
->nr
4288 * sizeof(struct perf_branch_entry
);
4290 header
->size
+= size
;
4293 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4294 /* regs dump ABI info */
4295 int size
= sizeof(u64
);
4297 perf_sample_regs_user(&data
->regs_user
, regs
);
4299 if (data
->regs_user
.regs
) {
4300 u64 mask
= event
->attr
.sample_regs_user
;
4301 size
+= hweight64(mask
) * sizeof(u64
);
4304 header
->size
+= size
;
4307 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
4309 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
4310 * processed as the last one or have additional check added
4311 * in case new sample type is added, because we could eat
4312 * up the rest of the sample size.
4314 struct perf_regs_user
*uregs
= &data
->regs_user
;
4315 u16 stack_size
= event
->attr
.sample_stack_user
;
4316 u16 size
= sizeof(u64
);
4319 perf_sample_regs_user(uregs
, regs
);
4321 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
4325 * If there is something to dump, add space for the dump
4326 * itself and for the field that tells the dynamic size,
4327 * which is how many have been actually dumped.
4330 size
+= sizeof(u64
) + stack_size
;
4332 data
->stack_user_size
= stack_size
;
4333 header
->size
+= size
;
4337 static void perf_event_output(struct perf_event
*event
,
4338 struct perf_sample_data
*data
,
4339 struct pt_regs
*regs
)
4341 struct perf_output_handle handle
;
4342 struct perf_event_header header
;
4344 /* protect the callchain buffers */
4347 perf_prepare_sample(&header
, data
, event
, regs
);
4349 if (perf_output_begin(&handle
, event
, header
.size
))
4352 perf_output_sample(&handle
, &header
, data
, event
);
4354 perf_output_end(&handle
);
4364 struct perf_read_event
{
4365 struct perf_event_header header
;
4372 perf_event_read_event(struct perf_event
*event
,
4373 struct task_struct
*task
)
4375 struct perf_output_handle handle
;
4376 struct perf_sample_data sample
;
4377 struct perf_read_event read_event
= {
4379 .type
= PERF_RECORD_READ
,
4381 .size
= sizeof(read_event
) + event
->read_size
,
4383 .pid
= perf_event_pid(event
, task
),
4384 .tid
= perf_event_tid(event
, task
),
4388 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4389 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
4393 perf_output_put(&handle
, read_event
);
4394 perf_output_read(&handle
, event
);
4395 perf_event__output_id_sample(event
, &handle
, &sample
);
4397 perf_output_end(&handle
);
4400 typedef int (perf_event_aux_match_cb
)(struct perf_event
*event
, void *data
);
4401 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
4404 perf_event_aux_ctx(struct perf_event_context
*ctx
,
4405 perf_event_aux_match_cb match
,
4406 perf_event_aux_output_cb output
,
4409 struct perf_event
*event
;
4411 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4412 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4414 if (!event_filter_match(event
))
4416 if (match(event
, data
))
4417 output(event
, data
);
4422 perf_event_aux(perf_event_aux_match_cb match
,
4423 perf_event_aux_output_cb output
,
4425 struct perf_event_context
*task_ctx
)
4427 struct perf_cpu_context
*cpuctx
;
4428 struct perf_event_context
*ctx
;
4433 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4434 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4435 if (cpuctx
->unique_pmu
!= pmu
)
4437 perf_event_aux_ctx(&cpuctx
->ctx
, match
, output
, data
);
4440 ctxn
= pmu
->task_ctx_nr
;
4443 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4445 perf_event_aux_ctx(ctx
, match
, output
, data
);
4447 put_cpu_ptr(pmu
->pmu_cpu_context
);
4452 perf_event_aux_ctx(task_ctx
, match
, output
, data
);
4459 * task tracking -- fork/exit
4461 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
4464 struct perf_task_event
{
4465 struct task_struct
*task
;
4466 struct perf_event_context
*task_ctx
;
4469 struct perf_event_header header
;
4479 static void perf_event_task_output(struct perf_event
*event
,
4482 struct perf_task_event
*task_event
= data
;
4483 struct perf_output_handle handle
;
4484 struct perf_sample_data sample
;
4485 struct task_struct
*task
= task_event
->task
;
4486 int ret
, size
= task_event
->event_id
.header
.size
;
4488 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4490 ret
= perf_output_begin(&handle
, event
,
4491 task_event
->event_id
.header
.size
);
4495 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4496 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4498 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4499 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4501 perf_output_put(&handle
, task_event
->event_id
);
4503 perf_event__output_id_sample(event
, &handle
, &sample
);
4505 perf_output_end(&handle
);
4507 task_event
->event_id
.header
.size
= size
;
4510 static int perf_event_task_match(struct perf_event
*event
,
4511 void *data __maybe_unused
)
4513 return event
->attr
.comm
|| event
->attr
.mmap
||
4514 event
->attr
.mmap_data
|| event
->attr
.task
;
4517 static void perf_event_task(struct task_struct
*task
,
4518 struct perf_event_context
*task_ctx
,
4521 struct perf_task_event task_event
;
4523 if (!atomic_read(&nr_comm_events
) &&
4524 !atomic_read(&nr_mmap_events
) &&
4525 !atomic_read(&nr_task_events
))
4528 task_event
= (struct perf_task_event
){
4530 .task_ctx
= task_ctx
,
4533 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4535 .size
= sizeof(task_event
.event_id
),
4541 .time
= perf_clock(),
4545 perf_event_aux(perf_event_task_match
,
4546 perf_event_task_output
,
4551 void perf_event_fork(struct task_struct
*task
)
4553 perf_event_task(task
, NULL
, 1);
4560 struct perf_comm_event
{
4561 struct task_struct
*task
;
4566 struct perf_event_header header
;
4573 static void perf_event_comm_output(struct perf_event
*event
,
4576 struct perf_comm_event
*comm_event
= data
;
4577 struct perf_output_handle handle
;
4578 struct perf_sample_data sample
;
4579 int size
= comm_event
->event_id
.header
.size
;
4582 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4583 ret
= perf_output_begin(&handle
, event
,
4584 comm_event
->event_id
.header
.size
);
4589 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4590 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4592 perf_output_put(&handle
, comm_event
->event_id
);
4593 __output_copy(&handle
, comm_event
->comm
,
4594 comm_event
->comm_size
);
4596 perf_event__output_id_sample(event
, &handle
, &sample
);
4598 perf_output_end(&handle
);
4600 comm_event
->event_id
.header
.size
= size
;
4603 static int perf_event_comm_match(struct perf_event
*event
,
4604 void *data __maybe_unused
)
4606 return event
->attr
.comm
;
4609 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4611 char comm
[TASK_COMM_LEN
];
4614 memset(comm
, 0, sizeof(comm
));
4615 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4616 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4618 comm_event
->comm
= comm
;
4619 comm_event
->comm_size
= size
;
4621 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4623 perf_event_aux(perf_event_comm_match
,
4624 perf_event_comm_output
,
4629 void perf_event_comm(struct task_struct
*task
)
4631 struct perf_comm_event comm_event
;
4632 struct perf_event_context
*ctx
;
4636 for_each_task_context_nr(ctxn
) {
4637 ctx
= task
->perf_event_ctxp
[ctxn
];
4641 perf_event_enable_on_exec(ctx
);
4645 if (!atomic_read(&nr_comm_events
))
4648 comm_event
= (struct perf_comm_event
){
4654 .type
= PERF_RECORD_COMM
,
4663 perf_event_comm_event(&comm_event
);
4670 struct perf_mmap_event
{
4671 struct vm_area_struct
*vma
;
4673 const char *file_name
;
4677 struct perf_event_header header
;
4687 static void perf_event_mmap_output(struct perf_event
*event
,
4690 struct perf_mmap_event
*mmap_event
= data
;
4691 struct perf_output_handle handle
;
4692 struct perf_sample_data sample
;
4693 int size
= mmap_event
->event_id
.header
.size
;
4696 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4697 ret
= perf_output_begin(&handle
, event
,
4698 mmap_event
->event_id
.header
.size
);
4702 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4703 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4705 perf_output_put(&handle
, mmap_event
->event_id
);
4706 __output_copy(&handle
, mmap_event
->file_name
,
4707 mmap_event
->file_size
);
4709 perf_event__output_id_sample(event
, &handle
, &sample
);
4711 perf_output_end(&handle
);
4713 mmap_event
->event_id
.header
.size
= size
;
4716 static int perf_event_mmap_match(struct perf_event
*event
,
4719 struct perf_mmap_event
*mmap_event
= data
;
4720 struct vm_area_struct
*vma
= mmap_event
->vma
;
4721 int executable
= vma
->vm_flags
& VM_EXEC
;
4723 return (!executable
&& event
->attr
.mmap_data
) ||
4724 (executable
&& event
->attr
.mmap
);
4727 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4729 struct vm_area_struct
*vma
= mmap_event
->vma
;
4730 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 if (!(vma
->vm_flags
& VM_EXEC
))
4786 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
4788 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4790 perf_event_aux(perf_event_mmap_match
,
4791 perf_event_mmap_output
,
4798 void perf_event_mmap(struct vm_area_struct
*vma
)
4800 struct perf_mmap_event mmap_event
;
4802 if (!atomic_read(&nr_mmap_events
))
4805 mmap_event
= (struct perf_mmap_event
){
4811 .type
= PERF_RECORD_MMAP
,
4812 .misc
= PERF_RECORD_MISC_USER
,
4817 .start
= vma
->vm_start
,
4818 .len
= vma
->vm_end
- vma
->vm_start
,
4819 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4823 perf_event_mmap_event(&mmap_event
);
4827 * IRQ throttle logging
4830 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4832 struct perf_output_handle handle
;
4833 struct perf_sample_data sample
;
4837 struct perf_event_header header
;
4841 } throttle_event
= {
4843 .type
= PERF_RECORD_THROTTLE
,
4845 .size
= sizeof(throttle_event
),
4847 .time
= perf_clock(),
4848 .id
= primary_event_id(event
),
4849 .stream_id
= event
->id
,
4853 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4855 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4857 ret
= perf_output_begin(&handle
, event
,
4858 throttle_event
.header
.size
);
4862 perf_output_put(&handle
, throttle_event
);
4863 perf_event__output_id_sample(event
, &handle
, &sample
);
4864 perf_output_end(&handle
);
4868 * Generic event overflow handling, sampling.
4871 static int __perf_event_overflow(struct perf_event
*event
,
4872 int throttle
, struct perf_sample_data
*data
,
4873 struct pt_regs
*regs
)
4875 int events
= atomic_read(&event
->event_limit
);
4876 struct hw_perf_event
*hwc
= &event
->hw
;
4881 * Non-sampling counters might still use the PMI to fold short
4882 * hardware counters, ignore those.
4884 if (unlikely(!is_sampling_event(event
)))
4887 seq
= __this_cpu_read(perf_throttled_seq
);
4888 if (seq
!= hwc
->interrupts_seq
) {
4889 hwc
->interrupts_seq
= seq
;
4890 hwc
->interrupts
= 1;
4893 if (unlikely(throttle
4894 && hwc
->interrupts
>= max_samples_per_tick
)) {
4895 __this_cpu_inc(perf_throttled_count
);
4896 hwc
->interrupts
= MAX_INTERRUPTS
;
4897 perf_log_throttle(event
, 0);
4902 if (event
->attr
.freq
) {
4903 u64 now
= perf_clock();
4904 s64 delta
= now
- hwc
->freq_time_stamp
;
4906 hwc
->freq_time_stamp
= now
;
4908 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4909 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
4913 * XXX event_limit might not quite work as expected on inherited
4917 event
->pending_kill
= POLL_IN
;
4918 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4920 event
->pending_kill
= POLL_HUP
;
4921 event
->pending_disable
= 1;
4922 irq_work_queue(&event
->pending
);
4925 if (event
->overflow_handler
)
4926 event
->overflow_handler(event
, data
, regs
);
4928 perf_event_output(event
, data
, regs
);
4930 if (event
->fasync
&& event
->pending_kill
) {
4931 event
->pending_wakeup
= 1;
4932 irq_work_queue(&event
->pending
);
4938 int perf_event_overflow(struct perf_event
*event
,
4939 struct perf_sample_data
*data
,
4940 struct pt_regs
*regs
)
4942 return __perf_event_overflow(event
, 1, data
, regs
);
4946 * Generic software event infrastructure
4949 struct swevent_htable
{
4950 struct swevent_hlist
*swevent_hlist
;
4951 struct mutex hlist_mutex
;
4954 /* Recursion avoidance in each contexts */
4955 int recursion
[PERF_NR_CONTEXTS
];
4958 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
4961 * We directly increment event->count and keep a second value in
4962 * event->hw.period_left to count intervals. This period event
4963 * is kept in the range [-sample_period, 0] so that we can use the
4967 static u64
perf_swevent_set_period(struct perf_event
*event
)
4969 struct hw_perf_event
*hwc
= &event
->hw
;
4970 u64 period
= hwc
->last_period
;
4974 hwc
->last_period
= hwc
->sample_period
;
4977 old
= val
= local64_read(&hwc
->period_left
);
4981 nr
= div64_u64(period
+ val
, period
);
4982 offset
= nr
* period
;
4984 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
4990 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
4991 struct perf_sample_data
*data
,
4992 struct pt_regs
*regs
)
4994 struct hw_perf_event
*hwc
= &event
->hw
;
4998 overflow
= perf_swevent_set_period(event
);
5000 if (hwc
->interrupts
== MAX_INTERRUPTS
)
5003 for (; overflow
; overflow
--) {
5004 if (__perf_event_overflow(event
, throttle
,
5007 * We inhibit the overflow from happening when
5008 * hwc->interrupts == MAX_INTERRUPTS.
5016 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
5017 struct perf_sample_data
*data
,
5018 struct pt_regs
*regs
)
5020 struct hw_perf_event
*hwc
= &event
->hw
;
5022 local64_add(nr
, &event
->count
);
5027 if (!is_sampling_event(event
))
5030 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
5032 return perf_swevent_overflow(event
, 1, data
, regs
);
5034 data
->period
= event
->hw
.last_period
;
5036 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
5037 return perf_swevent_overflow(event
, 1, data
, regs
);
5039 if (local64_add_negative(nr
, &hwc
->period_left
))
5042 perf_swevent_overflow(event
, 0, data
, regs
);
5045 static int perf_exclude_event(struct perf_event
*event
,
5046 struct pt_regs
*regs
)
5048 if (event
->hw
.state
& PERF_HES_STOPPED
)
5052 if (event
->attr
.exclude_user
&& user_mode(regs
))
5055 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
5062 static int perf_swevent_match(struct perf_event
*event
,
5063 enum perf_type_id type
,
5065 struct perf_sample_data
*data
,
5066 struct pt_regs
*regs
)
5068 if (event
->attr
.type
!= type
)
5071 if (event
->attr
.config
!= event_id
)
5074 if (perf_exclude_event(event
, regs
))
5080 static inline u64
swevent_hash(u64 type
, u32 event_id
)
5082 u64 val
= event_id
| (type
<< 32);
5084 return hash_64(val
, SWEVENT_HLIST_BITS
);
5087 static inline struct hlist_head
*
5088 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
5090 u64 hash
= swevent_hash(type
, event_id
);
5092 return &hlist
->heads
[hash
];
5095 /* For the read side: events when they trigger */
5096 static inline struct hlist_head
*
5097 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
5099 struct swevent_hlist
*hlist
;
5101 hlist
= rcu_dereference(swhash
->swevent_hlist
);
5105 return __find_swevent_head(hlist
, type
, event_id
);
5108 /* For the event head insertion and removal in the hlist */
5109 static inline struct hlist_head
*
5110 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
5112 struct swevent_hlist
*hlist
;
5113 u32 event_id
= event
->attr
.config
;
5114 u64 type
= event
->attr
.type
;
5117 * Event scheduling is always serialized against hlist allocation
5118 * and release. Which makes the protected version suitable here.
5119 * The context lock guarantees that.
5121 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
5122 lockdep_is_held(&event
->ctx
->lock
));
5126 return __find_swevent_head(hlist
, type
, event_id
);
5129 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
5131 struct perf_sample_data
*data
,
5132 struct pt_regs
*regs
)
5134 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5135 struct perf_event
*event
;
5136 struct hlist_head
*head
;
5139 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
5143 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5144 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
5145 perf_swevent_event(event
, nr
, data
, regs
);
5151 int perf_swevent_get_recursion_context(void)
5153 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5155 return get_recursion_context(swhash
->recursion
);
5157 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
5159 inline void perf_swevent_put_recursion_context(int rctx
)
5161 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5163 put_recursion_context(swhash
->recursion
, rctx
);
5166 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
5168 struct perf_sample_data data
;
5171 preempt_disable_notrace();
5172 rctx
= perf_swevent_get_recursion_context();
5176 perf_sample_data_init(&data
, addr
, 0);
5178 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
5180 perf_swevent_put_recursion_context(rctx
);
5181 preempt_enable_notrace();
5184 static void perf_swevent_read(struct perf_event
*event
)
5188 static int perf_swevent_add(struct perf_event
*event
, int flags
)
5190 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5191 struct hw_perf_event
*hwc
= &event
->hw
;
5192 struct hlist_head
*head
;
5194 if (is_sampling_event(event
)) {
5195 hwc
->last_period
= hwc
->sample_period
;
5196 perf_swevent_set_period(event
);
5199 hwc
->state
= !(flags
& PERF_EF_START
);
5201 head
= find_swevent_head(swhash
, event
);
5202 if (WARN_ON_ONCE(!head
))
5205 hlist_add_head_rcu(&event
->hlist_entry
, head
);
5210 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5212 hlist_del_rcu(&event
->hlist_entry
);
5215 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5217 event
->hw
.state
= 0;
5220 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5222 event
->hw
.state
= PERF_HES_STOPPED
;
5225 /* Deref the hlist from the update side */
5226 static inline struct swevent_hlist
*
5227 swevent_hlist_deref(struct swevent_htable
*swhash
)
5229 return rcu_dereference_protected(swhash
->swevent_hlist
,
5230 lockdep_is_held(&swhash
->hlist_mutex
));
5233 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5235 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5240 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5241 kfree_rcu(hlist
, rcu_head
);
5244 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5246 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5248 mutex_lock(&swhash
->hlist_mutex
);
5250 if (!--swhash
->hlist_refcount
)
5251 swevent_hlist_release(swhash
);
5253 mutex_unlock(&swhash
->hlist_mutex
);
5256 static void swevent_hlist_put(struct perf_event
*event
)
5260 if (event
->cpu
!= -1) {
5261 swevent_hlist_put_cpu(event
, event
->cpu
);
5265 for_each_possible_cpu(cpu
)
5266 swevent_hlist_put_cpu(event
, cpu
);
5269 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5271 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5274 mutex_lock(&swhash
->hlist_mutex
);
5276 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5277 struct swevent_hlist
*hlist
;
5279 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5284 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5286 swhash
->hlist_refcount
++;
5288 mutex_unlock(&swhash
->hlist_mutex
);
5293 static int swevent_hlist_get(struct perf_event
*event
)
5296 int cpu
, failed_cpu
;
5298 if (event
->cpu
!= -1)
5299 return swevent_hlist_get_cpu(event
, event
->cpu
);
5302 for_each_possible_cpu(cpu
) {
5303 err
= swevent_hlist_get_cpu(event
, cpu
);
5313 for_each_possible_cpu(cpu
) {
5314 if (cpu
== failed_cpu
)
5316 swevent_hlist_put_cpu(event
, cpu
);
5323 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5325 static void sw_perf_event_destroy(struct perf_event
*event
)
5327 u64 event_id
= event
->attr
.config
;
5329 WARN_ON(event
->parent
);
5331 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
5332 swevent_hlist_put(event
);
5335 static int perf_swevent_init(struct perf_event
*event
)
5337 u64 event_id
= event
->attr
.config
;
5339 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5343 * no branch sampling for software events
5345 if (has_branch_stack(event
))
5349 case PERF_COUNT_SW_CPU_CLOCK
:
5350 case PERF_COUNT_SW_TASK_CLOCK
:
5357 if (event_id
>= PERF_COUNT_SW_MAX
)
5360 if (!event
->parent
) {
5363 err
= swevent_hlist_get(event
);
5367 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
5368 event
->destroy
= sw_perf_event_destroy
;
5374 static int perf_swevent_event_idx(struct perf_event
*event
)
5379 static struct pmu perf_swevent
= {
5380 .task_ctx_nr
= perf_sw_context
,
5382 .event_init
= perf_swevent_init
,
5383 .add
= perf_swevent_add
,
5384 .del
= perf_swevent_del
,
5385 .start
= perf_swevent_start
,
5386 .stop
= perf_swevent_stop
,
5387 .read
= perf_swevent_read
,
5389 .event_idx
= perf_swevent_event_idx
,
5392 #ifdef CONFIG_EVENT_TRACING
5394 static int perf_tp_filter_match(struct perf_event
*event
,
5395 struct perf_sample_data
*data
)
5397 void *record
= data
->raw
->data
;
5399 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5404 static int perf_tp_event_match(struct perf_event
*event
,
5405 struct perf_sample_data
*data
,
5406 struct pt_regs
*regs
)
5408 if (event
->hw
.state
& PERF_HES_STOPPED
)
5411 * All tracepoints are from kernel-space.
5413 if (event
->attr
.exclude_kernel
)
5416 if (!perf_tp_filter_match(event
, data
))
5422 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5423 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
5424 struct task_struct
*task
)
5426 struct perf_sample_data data
;
5427 struct perf_event
*event
;
5429 struct perf_raw_record raw
= {
5434 perf_sample_data_init(&data
, addr
, 0);
5437 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5438 if (perf_tp_event_match(event
, &data
, regs
))
5439 perf_swevent_event(event
, count
, &data
, regs
);
5443 * If we got specified a target task, also iterate its context and
5444 * deliver this event there too.
5446 if (task
&& task
!= current
) {
5447 struct perf_event_context
*ctx
;
5448 struct trace_entry
*entry
= record
;
5451 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
5455 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5456 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5458 if (event
->attr
.config
!= entry
->type
)
5460 if (perf_tp_event_match(event
, &data
, regs
))
5461 perf_swevent_event(event
, count
, &data
, regs
);
5467 perf_swevent_put_recursion_context(rctx
);
5469 EXPORT_SYMBOL_GPL(perf_tp_event
);
5471 static void tp_perf_event_destroy(struct perf_event
*event
)
5473 perf_trace_destroy(event
);
5476 static int perf_tp_event_init(struct perf_event
*event
)
5480 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5484 * no branch sampling for tracepoint events
5486 if (has_branch_stack(event
))
5489 err
= perf_trace_init(event
);
5493 event
->destroy
= tp_perf_event_destroy
;
5498 static struct pmu perf_tracepoint
= {
5499 .task_ctx_nr
= perf_sw_context
,
5501 .event_init
= perf_tp_event_init
,
5502 .add
= perf_trace_add
,
5503 .del
= perf_trace_del
,
5504 .start
= perf_swevent_start
,
5505 .stop
= perf_swevent_stop
,
5506 .read
= perf_swevent_read
,
5508 .event_idx
= perf_swevent_event_idx
,
5511 static inline void perf_tp_register(void)
5513 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5516 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5521 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5524 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5525 if (IS_ERR(filter_str
))
5526 return PTR_ERR(filter_str
);
5528 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5534 static void perf_event_free_filter(struct perf_event
*event
)
5536 ftrace_profile_free_filter(event
);
5541 static inline void perf_tp_register(void)
5545 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5550 static void perf_event_free_filter(struct perf_event
*event
)
5554 #endif /* CONFIG_EVENT_TRACING */
5556 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5557 void perf_bp_event(struct perf_event
*bp
, void *data
)
5559 struct perf_sample_data sample
;
5560 struct pt_regs
*regs
= data
;
5562 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
5564 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5565 perf_swevent_event(bp
, 1, &sample
, regs
);
5570 * hrtimer based swevent callback
5573 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5575 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5576 struct perf_sample_data data
;
5577 struct pt_regs
*regs
;
5578 struct perf_event
*event
;
5581 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5583 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5584 return HRTIMER_NORESTART
;
5586 event
->pmu
->read(event
);
5588 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
5589 regs
= get_irq_regs();
5591 if (regs
&& !perf_exclude_event(event
, regs
)) {
5592 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
5593 if (__perf_event_overflow(event
, 1, &data
, regs
))
5594 ret
= HRTIMER_NORESTART
;
5597 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5598 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5603 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5605 struct hw_perf_event
*hwc
= &event
->hw
;
5608 if (!is_sampling_event(event
))
5611 period
= local64_read(&hwc
->period_left
);
5616 local64_set(&hwc
->period_left
, 0);
5618 period
= max_t(u64
, 10000, hwc
->sample_period
);
5620 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5621 ns_to_ktime(period
), 0,
5622 HRTIMER_MODE_REL_PINNED
, 0);
5625 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5627 struct hw_perf_event
*hwc
= &event
->hw
;
5629 if (is_sampling_event(event
)) {
5630 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5631 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5633 hrtimer_cancel(&hwc
->hrtimer
);
5637 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
5639 struct hw_perf_event
*hwc
= &event
->hw
;
5641 if (!is_sampling_event(event
))
5644 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5645 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5648 * Since hrtimers have a fixed rate, we can do a static freq->period
5649 * mapping and avoid the whole period adjust feedback stuff.
5651 if (event
->attr
.freq
) {
5652 long freq
= event
->attr
.sample_freq
;
5654 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
5655 hwc
->sample_period
= event
->attr
.sample_period
;
5656 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5657 hwc
->last_period
= hwc
->sample_period
;
5658 event
->attr
.freq
= 0;
5663 * Software event: cpu wall time clock
5666 static void cpu_clock_event_update(struct perf_event
*event
)
5671 now
= local_clock();
5672 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5673 local64_add(now
- prev
, &event
->count
);
5676 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5678 local64_set(&event
->hw
.prev_count
, local_clock());
5679 perf_swevent_start_hrtimer(event
);
5682 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5684 perf_swevent_cancel_hrtimer(event
);
5685 cpu_clock_event_update(event
);
5688 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5690 if (flags
& PERF_EF_START
)
5691 cpu_clock_event_start(event
, flags
);
5696 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5698 cpu_clock_event_stop(event
, flags
);
5701 static void cpu_clock_event_read(struct perf_event
*event
)
5703 cpu_clock_event_update(event
);
5706 static int cpu_clock_event_init(struct perf_event
*event
)
5708 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5711 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5715 * no branch sampling for software events
5717 if (has_branch_stack(event
))
5720 perf_swevent_init_hrtimer(event
);
5725 static struct pmu perf_cpu_clock
= {
5726 .task_ctx_nr
= perf_sw_context
,
5728 .event_init
= cpu_clock_event_init
,
5729 .add
= cpu_clock_event_add
,
5730 .del
= cpu_clock_event_del
,
5731 .start
= cpu_clock_event_start
,
5732 .stop
= cpu_clock_event_stop
,
5733 .read
= cpu_clock_event_read
,
5735 .event_idx
= perf_swevent_event_idx
,
5739 * Software event: task time clock
5742 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5747 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5749 local64_add(delta
, &event
->count
);
5752 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5754 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5755 perf_swevent_start_hrtimer(event
);
5758 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5760 perf_swevent_cancel_hrtimer(event
);
5761 task_clock_event_update(event
, event
->ctx
->time
);
5764 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5766 if (flags
& PERF_EF_START
)
5767 task_clock_event_start(event
, flags
);
5772 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5774 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5777 static void task_clock_event_read(struct perf_event
*event
)
5779 u64 now
= perf_clock();
5780 u64 delta
= now
- event
->ctx
->timestamp
;
5781 u64 time
= event
->ctx
->time
+ delta
;
5783 task_clock_event_update(event
, time
);
5786 static int task_clock_event_init(struct perf_event
*event
)
5788 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5791 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5795 * no branch sampling for software events
5797 if (has_branch_stack(event
))
5800 perf_swevent_init_hrtimer(event
);
5805 static struct pmu perf_task_clock
= {
5806 .task_ctx_nr
= perf_sw_context
,
5808 .event_init
= task_clock_event_init
,
5809 .add
= task_clock_event_add
,
5810 .del
= task_clock_event_del
,
5811 .start
= task_clock_event_start
,
5812 .stop
= task_clock_event_stop
,
5813 .read
= task_clock_event_read
,
5815 .event_idx
= perf_swevent_event_idx
,
5818 static void perf_pmu_nop_void(struct pmu
*pmu
)
5822 static int perf_pmu_nop_int(struct pmu
*pmu
)
5827 static void perf_pmu_start_txn(struct pmu
*pmu
)
5829 perf_pmu_disable(pmu
);
5832 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5834 perf_pmu_enable(pmu
);
5838 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5840 perf_pmu_enable(pmu
);
5843 static int perf_event_idx_default(struct perf_event
*event
)
5845 return event
->hw
.idx
+ 1;
5849 * Ensures all contexts with the same task_ctx_nr have the same
5850 * pmu_cpu_context too.
5852 static void *find_pmu_context(int ctxn
)
5859 list_for_each_entry(pmu
, &pmus
, entry
) {
5860 if (pmu
->task_ctx_nr
== ctxn
)
5861 return pmu
->pmu_cpu_context
;
5867 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5871 for_each_possible_cpu(cpu
) {
5872 struct perf_cpu_context
*cpuctx
;
5874 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5876 if (cpuctx
->unique_pmu
== old_pmu
)
5877 cpuctx
->unique_pmu
= pmu
;
5881 static void free_pmu_context(struct pmu
*pmu
)
5885 mutex_lock(&pmus_lock
);
5887 * Like a real lame refcount.
5889 list_for_each_entry(i
, &pmus
, entry
) {
5890 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5891 update_pmu_context(i
, pmu
);
5896 free_percpu(pmu
->pmu_cpu_context
);
5898 mutex_unlock(&pmus_lock
);
5900 static struct idr pmu_idr
;
5903 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5905 struct pmu
*pmu
= dev_get_drvdata(dev
);
5907 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5910 static struct device_attribute pmu_dev_attrs
[] = {
5915 static int pmu_bus_running
;
5916 static struct bus_type pmu_bus
= {
5917 .name
= "event_source",
5918 .dev_attrs
= pmu_dev_attrs
,
5921 static void pmu_dev_release(struct device
*dev
)
5926 static int pmu_dev_alloc(struct pmu
*pmu
)
5930 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5934 pmu
->dev
->groups
= pmu
->attr_groups
;
5935 device_initialize(pmu
->dev
);
5936 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5940 dev_set_drvdata(pmu
->dev
, pmu
);
5941 pmu
->dev
->bus
= &pmu_bus
;
5942 pmu
->dev
->release
= pmu_dev_release
;
5943 ret
= device_add(pmu
->dev
);
5951 put_device(pmu
->dev
);
5955 static struct lock_class_key cpuctx_mutex
;
5956 static struct lock_class_key cpuctx_lock
;
5958 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5962 mutex_lock(&pmus_lock
);
5964 pmu
->pmu_disable_count
= alloc_percpu(int);
5965 if (!pmu
->pmu_disable_count
)
5974 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
5982 if (pmu_bus_running
) {
5983 ret
= pmu_dev_alloc(pmu
);
5989 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
5990 if (pmu
->pmu_cpu_context
)
5991 goto got_cpu_context
;
5994 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
5995 if (!pmu
->pmu_cpu_context
)
5998 for_each_possible_cpu(cpu
) {
5999 struct perf_cpu_context
*cpuctx
;
6001 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6002 __perf_event_init_context(&cpuctx
->ctx
);
6003 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
6004 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
6005 cpuctx
->ctx
.type
= cpu_context
;
6006 cpuctx
->ctx
.pmu
= pmu
;
6007 cpuctx
->jiffies_interval
= 1;
6008 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
6009 cpuctx
->unique_pmu
= pmu
;
6013 if (!pmu
->start_txn
) {
6014 if (pmu
->pmu_enable
) {
6016 * If we have pmu_enable/pmu_disable calls, install
6017 * transaction stubs that use that to try and batch
6018 * hardware accesses.
6020 pmu
->start_txn
= perf_pmu_start_txn
;
6021 pmu
->commit_txn
= perf_pmu_commit_txn
;
6022 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
6024 pmu
->start_txn
= perf_pmu_nop_void
;
6025 pmu
->commit_txn
= perf_pmu_nop_int
;
6026 pmu
->cancel_txn
= perf_pmu_nop_void
;
6030 if (!pmu
->pmu_enable
) {
6031 pmu
->pmu_enable
= perf_pmu_nop_void
;
6032 pmu
->pmu_disable
= perf_pmu_nop_void
;
6035 if (!pmu
->event_idx
)
6036 pmu
->event_idx
= perf_event_idx_default
;
6038 list_add_rcu(&pmu
->entry
, &pmus
);
6041 mutex_unlock(&pmus_lock
);
6046 device_del(pmu
->dev
);
6047 put_device(pmu
->dev
);
6050 if (pmu
->type
>= PERF_TYPE_MAX
)
6051 idr_remove(&pmu_idr
, pmu
->type
);
6054 free_percpu(pmu
->pmu_disable_count
);
6058 void perf_pmu_unregister(struct pmu
*pmu
)
6060 mutex_lock(&pmus_lock
);
6061 list_del_rcu(&pmu
->entry
);
6062 mutex_unlock(&pmus_lock
);
6065 * We dereference the pmu list under both SRCU and regular RCU, so
6066 * synchronize against both of those.
6068 synchronize_srcu(&pmus_srcu
);
6071 free_percpu(pmu
->pmu_disable_count
);
6072 if (pmu
->type
>= PERF_TYPE_MAX
)
6073 idr_remove(&pmu_idr
, pmu
->type
);
6074 device_del(pmu
->dev
);
6075 put_device(pmu
->dev
);
6076 free_pmu_context(pmu
);
6079 struct pmu
*perf_init_event(struct perf_event
*event
)
6081 struct pmu
*pmu
= NULL
;
6085 idx
= srcu_read_lock(&pmus_srcu
);
6088 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
6092 ret
= pmu
->event_init(event
);
6098 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6100 ret
= pmu
->event_init(event
);
6104 if (ret
!= -ENOENT
) {
6109 pmu
= ERR_PTR(-ENOENT
);
6111 srcu_read_unlock(&pmus_srcu
, idx
);
6117 * Allocate and initialize a event structure
6119 static struct perf_event
*
6120 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
6121 struct task_struct
*task
,
6122 struct perf_event
*group_leader
,
6123 struct perf_event
*parent_event
,
6124 perf_overflow_handler_t overflow_handler
,
6128 struct perf_event
*event
;
6129 struct hw_perf_event
*hwc
;
6132 if ((unsigned)cpu
>= nr_cpu_ids
) {
6133 if (!task
|| cpu
!= -1)
6134 return ERR_PTR(-EINVAL
);
6137 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
6139 return ERR_PTR(-ENOMEM
);
6142 * Single events are their own group leaders, with an
6143 * empty sibling list:
6146 group_leader
= event
;
6148 mutex_init(&event
->child_mutex
);
6149 INIT_LIST_HEAD(&event
->child_list
);
6151 INIT_LIST_HEAD(&event
->group_entry
);
6152 INIT_LIST_HEAD(&event
->event_entry
);
6153 INIT_LIST_HEAD(&event
->sibling_list
);
6154 INIT_LIST_HEAD(&event
->rb_entry
);
6156 init_waitqueue_head(&event
->waitq
);
6157 init_irq_work(&event
->pending
, perf_pending_event
);
6159 mutex_init(&event
->mmap_mutex
);
6161 atomic_long_set(&event
->refcount
, 1);
6163 event
->attr
= *attr
;
6164 event
->group_leader
= group_leader
;
6168 event
->parent
= parent_event
;
6170 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
6171 event
->id
= atomic64_inc_return(&perf_event_id
);
6173 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6176 event
->attach_state
= PERF_ATTACH_TASK
;
6178 if (attr
->type
== PERF_TYPE_TRACEPOINT
)
6179 event
->hw
.tp_target
= task
;
6180 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6182 * hw_breakpoint is a bit difficult here..
6184 else if (attr
->type
== PERF_TYPE_BREAKPOINT
)
6185 event
->hw
.bp_target
= task
;
6189 if (!overflow_handler
&& parent_event
) {
6190 overflow_handler
= parent_event
->overflow_handler
;
6191 context
= parent_event
->overflow_handler_context
;
6194 event
->overflow_handler
= overflow_handler
;
6195 event
->overflow_handler_context
= context
;
6197 perf_event__state_init(event
);
6202 hwc
->sample_period
= attr
->sample_period
;
6203 if (attr
->freq
&& attr
->sample_freq
)
6204 hwc
->sample_period
= 1;
6205 hwc
->last_period
= hwc
->sample_period
;
6207 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6210 * we currently do not support PERF_FORMAT_GROUP on inherited events
6212 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
6215 pmu
= perf_init_event(event
);
6221 else if (IS_ERR(pmu
))
6226 put_pid_ns(event
->ns
);
6228 return ERR_PTR(err
);
6231 if (!event
->parent
) {
6232 if (event
->attach_state
& PERF_ATTACH_TASK
)
6233 static_key_slow_inc(&perf_sched_events
.key
);
6234 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
6235 atomic_inc(&nr_mmap_events
);
6236 if (event
->attr
.comm
)
6237 atomic_inc(&nr_comm_events
);
6238 if (event
->attr
.task
)
6239 atomic_inc(&nr_task_events
);
6240 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6241 err
= get_callchain_buffers();
6244 return ERR_PTR(err
);
6247 if (has_branch_stack(event
)) {
6248 static_key_slow_inc(&perf_sched_events
.key
);
6249 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
6250 atomic_inc(&per_cpu(perf_branch_stack_events
,
6258 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6259 struct perf_event_attr
*attr
)
6264 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6268 * zero the full structure, so that a short copy will be nice.
6270 memset(attr
, 0, sizeof(*attr
));
6272 ret
= get_user(size
, &uattr
->size
);
6276 if (size
> PAGE_SIZE
) /* silly large */
6279 if (!size
) /* abi compat */
6280 size
= PERF_ATTR_SIZE_VER0
;
6282 if (size
< PERF_ATTR_SIZE_VER0
)
6286 * If we're handed a bigger struct than we know of,
6287 * ensure all the unknown bits are 0 - i.e. new
6288 * user-space does not rely on any kernel feature
6289 * extensions we dont know about yet.
6291 if (size
> sizeof(*attr
)) {
6292 unsigned char __user
*addr
;
6293 unsigned char __user
*end
;
6296 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6297 end
= (void __user
*)uattr
+ size
;
6299 for (; addr
< end
; addr
++) {
6300 ret
= get_user(val
, addr
);
6306 size
= sizeof(*attr
);
6309 ret
= copy_from_user(attr
, uattr
, size
);
6313 if (attr
->__reserved_1
)
6316 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6319 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6322 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6323 u64 mask
= attr
->branch_sample_type
;
6325 /* only using defined bits */
6326 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
6329 /* at least one branch bit must be set */
6330 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
6333 /* kernel level capture: check permissions */
6334 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
6335 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6338 /* propagate priv level, when not set for branch */
6339 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
6341 /* exclude_kernel checked on syscall entry */
6342 if (!attr
->exclude_kernel
)
6343 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
6345 if (!attr
->exclude_user
)
6346 mask
|= PERF_SAMPLE_BRANCH_USER
;
6348 if (!attr
->exclude_hv
)
6349 mask
|= PERF_SAMPLE_BRANCH_HV
;
6351 * adjust user setting (for HW filter setup)
6353 attr
->branch_sample_type
= mask
;
6357 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
6358 ret
= perf_reg_validate(attr
->sample_regs_user
);
6363 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
6364 if (!arch_perf_have_user_stack_dump())
6368 * We have __u32 type for the size, but so far
6369 * we can only use __u16 as maximum due to the
6370 * __u16 sample size limit.
6372 if (attr
->sample_stack_user
>= USHRT_MAX
)
6374 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
6382 put_user(sizeof(*attr
), &uattr
->size
);
6388 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
6390 struct ring_buffer
*rb
= NULL
, *old_rb
= NULL
;
6396 /* don't allow circular references */
6397 if (event
== output_event
)
6401 * Don't allow cross-cpu buffers
6403 if (output_event
->cpu
!= event
->cpu
)
6407 * If its not a per-cpu rb, it must be the same task.
6409 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
6413 mutex_lock(&event
->mmap_mutex
);
6414 /* Can't redirect output if we've got an active mmap() */
6415 if (atomic_read(&event
->mmap_count
))
6419 /* get the rb we want to redirect to */
6420 rb
= ring_buffer_get(output_event
);
6426 rcu_assign_pointer(event
->rb
, rb
);
6428 ring_buffer_detach(event
, old_rb
);
6431 mutex_unlock(&event
->mmap_mutex
);
6434 ring_buffer_put(old_rb
);
6440 * sys_perf_event_open - open a performance event, associate it to a task/cpu
6442 * @attr_uptr: event_id type attributes for monitoring/sampling
6445 * @group_fd: group leader event fd
6447 SYSCALL_DEFINE5(perf_event_open
,
6448 struct perf_event_attr __user
*, attr_uptr
,
6449 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
6451 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
6452 struct perf_event
*event
, *sibling
;
6453 struct perf_event_attr attr
;
6454 struct perf_event_context
*ctx
;
6455 struct file
*event_file
= NULL
;
6456 struct fd group
= {NULL
, 0};
6457 struct task_struct
*task
= NULL
;
6463 /* for future expandability... */
6464 if (flags
& ~PERF_FLAG_ALL
)
6467 err
= perf_copy_attr(attr_uptr
, &attr
);
6471 if (!attr
.exclude_kernel
) {
6472 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6477 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
6482 * In cgroup mode, the pid argument is used to pass the fd
6483 * opened to the cgroup directory in cgroupfs. The cpu argument
6484 * designates the cpu on which to monitor threads from that
6487 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
6490 event_fd
= get_unused_fd();
6494 if (group_fd
!= -1) {
6495 err
= perf_fget_light(group_fd
, &group
);
6498 group_leader
= group
.file
->private_data
;
6499 if (flags
& PERF_FLAG_FD_OUTPUT
)
6500 output_event
= group_leader
;
6501 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6502 group_leader
= NULL
;
6505 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6506 task
= find_lively_task_by_vpid(pid
);
6508 err
= PTR_ERR(task
);
6515 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
6517 if (IS_ERR(event
)) {
6518 err
= PTR_ERR(event
);
6522 if (flags
& PERF_FLAG_PID_CGROUP
) {
6523 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6528 * - that has cgroup constraint on event->cpu
6529 * - that may need work on context switch
6531 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
6532 static_key_slow_inc(&perf_sched_events
.key
);
6536 * Special case software events and allow them to be part of
6537 * any hardware group.
6542 (is_software_event(event
) != is_software_event(group_leader
))) {
6543 if (is_software_event(event
)) {
6545 * If event and group_leader are not both a software
6546 * event, and event is, then group leader is not.
6548 * Allow the addition of software events to !software
6549 * groups, this is safe because software events never
6552 pmu
= group_leader
->pmu
;
6553 } else if (is_software_event(group_leader
) &&
6554 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6556 * In case the group is a pure software group, and we
6557 * try to add a hardware event, move the whole group to
6558 * the hardware context.
6565 * Get the target context (task or percpu):
6567 ctx
= find_get_context(pmu
, task
, event
->cpu
);
6574 put_task_struct(task
);
6579 * Look up the group leader (we will attach this event to it):
6585 * Do not allow a recursive hierarchy (this new sibling
6586 * becoming part of another group-sibling):
6588 if (group_leader
->group_leader
!= group_leader
)
6591 * Do not allow to attach to a group in a different
6592 * task or CPU context:
6595 if (group_leader
->ctx
->type
!= ctx
->type
)
6598 if (group_leader
->ctx
!= ctx
)
6603 * Only a group leader can be exclusive or pinned
6605 if (attr
.exclusive
|| attr
.pinned
)
6610 err
= perf_event_set_output(event
, output_event
);
6615 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6616 if (IS_ERR(event_file
)) {
6617 err
= PTR_ERR(event_file
);
6622 struct perf_event_context
*gctx
= group_leader
->ctx
;
6624 mutex_lock(&gctx
->mutex
);
6625 perf_remove_from_context(group_leader
);
6628 * Removing from the context ends up with disabled
6629 * event. What we want here is event in the initial
6630 * startup state, ready to be add into new context.
6632 perf_event__state_init(group_leader
);
6633 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6635 perf_remove_from_context(sibling
);
6636 perf_event__state_init(sibling
);
6639 mutex_unlock(&gctx
->mutex
);
6643 WARN_ON_ONCE(ctx
->parent_ctx
);
6644 mutex_lock(&ctx
->mutex
);
6648 perf_install_in_context(ctx
, group_leader
, event
->cpu
);
6650 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6652 perf_install_in_context(ctx
, sibling
, event
->cpu
);
6657 perf_install_in_context(ctx
, event
, event
->cpu
);
6659 perf_unpin_context(ctx
);
6660 mutex_unlock(&ctx
->mutex
);
6664 event
->owner
= current
;
6666 mutex_lock(¤t
->perf_event_mutex
);
6667 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6668 mutex_unlock(¤t
->perf_event_mutex
);
6671 * Precalculate sample_data sizes
6673 perf_event__header_size(event
);
6674 perf_event__id_header_size(event
);
6677 * Drop the reference on the group_event after placing the
6678 * new event on the sibling_list. This ensures destruction
6679 * of the group leader will find the pointer to itself in
6680 * perf_group_detach().
6683 fd_install(event_fd
, event_file
);
6687 perf_unpin_context(ctx
);
6694 put_task_struct(task
);
6698 put_unused_fd(event_fd
);
6703 * perf_event_create_kernel_counter
6705 * @attr: attributes of the counter to create
6706 * @cpu: cpu in which the counter is bound
6707 * @task: task to profile (NULL for percpu)
6710 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6711 struct task_struct
*task
,
6712 perf_overflow_handler_t overflow_handler
,
6715 struct perf_event_context
*ctx
;
6716 struct perf_event
*event
;
6720 * Get the target context (task or percpu):
6723 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
6724 overflow_handler
, context
);
6725 if (IS_ERR(event
)) {
6726 err
= PTR_ERR(event
);
6730 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6736 WARN_ON_ONCE(ctx
->parent_ctx
);
6737 mutex_lock(&ctx
->mutex
);
6738 perf_install_in_context(ctx
, event
, cpu
);
6740 perf_unpin_context(ctx
);
6741 mutex_unlock(&ctx
->mutex
);
6748 return ERR_PTR(err
);
6750 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6752 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
6754 struct perf_event_context
*src_ctx
;
6755 struct perf_event_context
*dst_ctx
;
6756 struct perf_event
*event
, *tmp
;
6759 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
6760 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
6762 mutex_lock(&src_ctx
->mutex
);
6763 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
6765 perf_remove_from_context(event
);
6767 list_add(&event
->event_entry
, &events
);
6769 mutex_unlock(&src_ctx
->mutex
);
6773 mutex_lock(&dst_ctx
->mutex
);
6774 list_for_each_entry_safe(event
, tmp
, &events
, event_entry
) {
6775 list_del(&event
->event_entry
);
6776 if (event
->state
>= PERF_EVENT_STATE_OFF
)
6777 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6778 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
6781 mutex_unlock(&dst_ctx
->mutex
);
6783 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
6785 static void sync_child_event(struct perf_event
*child_event
,
6786 struct task_struct
*child
)
6788 struct perf_event
*parent_event
= child_event
->parent
;
6791 if (child_event
->attr
.inherit_stat
)
6792 perf_event_read_event(child_event
, child
);
6794 child_val
= perf_event_count(child_event
);
6797 * Add back the child's count to the parent's count:
6799 atomic64_add(child_val
, &parent_event
->child_count
);
6800 atomic64_add(child_event
->total_time_enabled
,
6801 &parent_event
->child_total_time_enabled
);
6802 atomic64_add(child_event
->total_time_running
,
6803 &parent_event
->child_total_time_running
);
6806 * Remove this event from the parent's list
6808 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6809 mutex_lock(&parent_event
->child_mutex
);
6810 list_del_init(&child_event
->child_list
);
6811 mutex_unlock(&parent_event
->child_mutex
);
6814 * Release the parent event, if this was the last
6817 put_event(parent_event
);
6821 __perf_event_exit_task(struct perf_event
*child_event
,
6822 struct perf_event_context
*child_ctx
,
6823 struct task_struct
*child
)
6825 if (child_event
->parent
) {
6826 raw_spin_lock_irq(&child_ctx
->lock
);
6827 perf_group_detach(child_event
);
6828 raw_spin_unlock_irq(&child_ctx
->lock
);
6831 perf_remove_from_context(child_event
);
6834 * It can happen that the parent exits first, and has events
6835 * that are still around due to the child reference. These
6836 * events need to be zapped.
6838 if (child_event
->parent
) {
6839 sync_child_event(child_event
, child
);
6840 free_event(child_event
);
6844 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6846 struct perf_event
*child_event
, *tmp
;
6847 struct perf_event_context
*child_ctx
;
6848 unsigned long flags
;
6850 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6851 perf_event_task(child
, NULL
, 0);
6855 local_irq_save(flags
);
6857 * We can't reschedule here because interrupts are disabled,
6858 * and either child is current or it is a task that can't be
6859 * scheduled, so we are now safe from rescheduling changing
6862 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6865 * Take the context lock here so that if find_get_context is
6866 * reading child->perf_event_ctxp, we wait until it has
6867 * incremented the context's refcount before we do put_ctx below.
6869 raw_spin_lock(&child_ctx
->lock
);
6870 task_ctx_sched_out(child_ctx
);
6871 child
->perf_event_ctxp
[ctxn
] = NULL
;
6873 * If this context is a clone; unclone it so it can't get
6874 * swapped to another process while we're removing all
6875 * the events from it.
6877 unclone_ctx(child_ctx
);
6878 update_context_time(child_ctx
);
6879 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6882 * Report the task dead after unscheduling the events so that we
6883 * won't get any samples after PERF_RECORD_EXIT. We can however still
6884 * get a few PERF_RECORD_READ events.
6886 perf_event_task(child
, child_ctx
, 0);
6889 * We can recurse on the same lock type through:
6891 * __perf_event_exit_task()
6892 * sync_child_event()
6894 * mutex_lock(&ctx->mutex)
6896 * But since its the parent context it won't be the same instance.
6898 mutex_lock(&child_ctx
->mutex
);
6901 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6903 __perf_event_exit_task(child_event
, child_ctx
, child
);
6905 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6907 __perf_event_exit_task(child_event
, child_ctx
, child
);
6910 * If the last event was a group event, it will have appended all
6911 * its siblings to the list, but we obtained 'tmp' before that which
6912 * will still point to the list head terminating the iteration.
6914 if (!list_empty(&child_ctx
->pinned_groups
) ||
6915 !list_empty(&child_ctx
->flexible_groups
))
6918 mutex_unlock(&child_ctx
->mutex
);
6924 * When a child task exits, feed back event values to parent events.
6926 void perf_event_exit_task(struct task_struct
*child
)
6928 struct perf_event
*event
, *tmp
;
6931 mutex_lock(&child
->perf_event_mutex
);
6932 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6934 list_del_init(&event
->owner_entry
);
6937 * Ensure the list deletion is visible before we clear
6938 * the owner, closes a race against perf_release() where
6939 * we need to serialize on the owner->perf_event_mutex.
6942 event
->owner
= NULL
;
6944 mutex_unlock(&child
->perf_event_mutex
);
6946 for_each_task_context_nr(ctxn
)
6947 perf_event_exit_task_context(child
, ctxn
);
6950 static void perf_free_event(struct perf_event
*event
,
6951 struct perf_event_context
*ctx
)
6953 struct perf_event
*parent
= event
->parent
;
6955 if (WARN_ON_ONCE(!parent
))
6958 mutex_lock(&parent
->child_mutex
);
6959 list_del_init(&event
->child_list
);
6960 mutex_unlock(&parent
->child_mutex
);
6964 perf_group_detach(event
);
6965 list_del_event(event
, ctx
);
6970 * free an unexposed, unused context as created by inheritance by
6971 * perf_event_init_task below, used by fork() in case of fail.
6973 void perf_event_free_task(struct task_struct
*task
)
6975 struct perf_event_context
*ctx
;
6976 struct perf_event
*event
, *tmp
;
6979 for_each_task_context_nr(ctxn
) {
6980 ctx
= task
->perf_event_ctxp
[ctxn
];
6984 mutex_lock(&ctx
->mutex
);
6986 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6988 perf_free_event(event
, ctx
);
6990 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6992 perf_free_event(event
, ctx
);
6994 if (!list_empty(&ctx
->pinned_groups
) ||
6995 !list_empty(&ctx
->flexible_groups
))
6998 mutex_unlock(&ctx
->mutex
);
7004 void perf_event_delayed_put(struct task_struct
*task
)
7008 for_each_task_context_nr(ctxn
)
7009 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
7013 * inherit a event from parent task to child task:
7015 static struct perf_event
*
7016 inherit_event(struct perf_event
*parent_event
,
7017 struct task_struct
*parent
,
7018 struct perf_event_context
*parent_ctx
,
7019 struct task_struct
*child
,
7020 struct perf_event
*group_leader
,
7021 struct perf_event_context
*child_ctx
)
7023 struct perf_event
*child_event
;
7024 unsigned long flags
;
7027 * Instead of creating recursive hierarchies of events,
7028 * we link inherited events back to the original parent,
7029 * which has a filp for sure, which we use as the reference
7032 if (parent_event
->parent
)
7033 parent_event
= parent_event
->parent
;
7035 child_event
= perf_event_alloc(&parent_event
->attr
,
7038 group_leader
, parent_event
,
7040 if (IS_ERR(child_event
))
7043 if (!atomic_long_inc_not_zero(&parent_event
->refcount
)) {
7044 free_event(child_event
);
7051 * Make the child state follow the state of the parent event,
7052 * not its attr.disabled bit. We hold the parent's mutex,
7053 * so we won't race with perf_event_{en, dis}able_family.
7055 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
7056 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
7058 child_event
->state
= PERF_EVENT_STATE_OFF
;
7060 if (parent_event
->attr
.freq
) {
7061 u64 sample_period
= parent_event
->hw
.sample_period
;
7062 struct hw_perf_event
*hwc
= &child_event
->hw
;
7064 hwc
->sample_period
= sample_period
;
7065 hwc
->last_period
= sample_period
;
7067 local64_set(&hwc
->period_left
, sample_period
);
7070 child_event
->ctx
= child_ctx
;
7071 child_event
->overflow_handler
= parent_event
->overflow_handler
;
7072 child_event
->overflow_handler_context
7073 = parent_event
->overflow_handler_context
;
7076 * Precalculate sample_data sizes
7078 perf_event__header_size(child_event
);
7079 perf_event__id_header_size(child_event
);
7082 * Link it up in the child's context:
7084 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
7085 add_event_to_ctx(child_event
, child_ctx
);
7086 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
7089 * Link this into the parent event's child list
7091 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7092 mutex_lock(&parent_event
->child_mutex
);
7093 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
7094 mutex_unlock(&parent_event
->child_mutex
);
7099 static int inherit_group(struct perf_event
*parent_event
,
7100 struct task_struct
*parent
,
7101 struct perf_event_context
*parent_ctx
,
7102 struct task_struct
*child
,
7103 struct perf_event_context
*child_ctx
)
7105 struct perf_event
*leader
;
7106 struct perf_event
*sub
;
7107 struct perf_event
*child_ctr
;
7109 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
7110 child
, NULL
, child_ctx
);
7112 return PTR_ERR(leader
);
7113 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
7114 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
7115 child
, leader
, child_ctx
);
7116 if (IS_ERR(child_ctr
))
7117 return PTR_ERR(child_ctr
);
7123 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
7124 struct perf_event_context
*parent_ctx
,
7125 struct task_struct
*child
, int ctxn
,
7129 struct perf_event_context
*child_ctx
;
7131 if (!event
->attr
.inherit
) {
7136 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7139 * This is executed from the parent task context, so
7140 * inherit events that have been marked for cloning.
7141 * First allocate and initialize a context for the
7145 child_ctx
= alloc_perf_context(event
->pmu
, child
);
7149 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
7152 ret
= inherit_group(event
, parent
, parent_ctx
,
7162 * Initialize the perf_event context in task_struct
7164 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
7166 struct perf_event_context
*child_ctx
, *parent_ctx
;
7167 struct perf_event_context
*cloned_ctx
;
7168 struct perf_event
*event
;
7169 struct task_struct
*parent
= current
;
7170 int inherited_all
= 1;
7171 unsigned long flags
;
7174 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
7178 * If the parent's context is a clone, pin it so it won't get
7181 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
7184 * No need to check if parent_ctx != NULL here; since we saw
7185 * it non-NULL earlier, the only reason for it to become NULL
7186 * is if we exit, and since we're currently in the middle of
7187 * a fork we can't be exiting at the same time.
7191 * Lock the parent list. No need to lock the child - not PID
7192 * hashed yet and not running, so nobody can access it.
7194 mutex_lock(&parent_ctx
->mutex
);
7197 * We dont have to disable NMIs - we are only looking at
7198 * the list, not manipulating it:
7200 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
7201 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7202 child
, ctxn
, &inherited_all
);
7208 * We can't hold ctx->lock when iterating the ->flexible_group list due
7209 * to allocations, but we need to prevent rotation because
7210 * rotate_ctx() will change the list from interrupt context.
7212 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7213 parent_ctx
->rotate_disable
= 1;
7214 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7216 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
7217 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7218 child
, ctxn
, &inherited_all
);
7223 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7224 parent_ctx
->rotate_disable
= 0;
7226 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7228 if (child_ctx
&& inherited_all
) {
7230 * Mark the child context as a clone of the parent
7231 * context, or of whatever the parent is a clone of.
7233 * Note that if the parent is a clone, the holding of
7234 * parent_ctx->lock avoids it from being uncloned.
7236 cloned_ctx
= parent_ctx
->parent_ctx
;
7238 child_ctx
->parent_ctx
= cloned_ctx
;
7239 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
7241 child_ctx
->parent_ctx
= parent_ctx
;
7242 child_ctx
->parent_gen
= parent_ctx
->generation
;
7244 get_ctx(child_ctx
->parent_ctx
);
7247 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7248 mutex_unlock(&parent_ctx
->mutex
);
7250 perf_unpin_context(parent_ctx
);
7251 put_ctx(parent_ctx
);
7257 * Initialize the perf_event context in task_struct
7259 int perf_event_init_task(struct task_struct
*child
)
7263 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7264 mutex_init(&child
->perf_event_mutex
);
7265 INIT_LIST_HEAD(&child
->perf_event_list
);
7267 for_each_task_context_nr(ctxn
) {
7268 ret
= perf_event_init_context(child
, ctxn
);
7276 static void __init
perf_event_init_all_cpus(void)
7278 struct swevent_htable
*swhash
;
7281 for_each_possible_cpu(cpu
) {
7282 swhash
= &per_cpu(swevent_htable
, cpu
);
7283 mutex_init(&swhash
->hlist_mutex
);
7284 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7288 static void __cpuinit
perf_event_init_cpu(int cpu
)
7290 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7292 mutex_lock(&swhash
->hlist_mutex
);
7293 if (swhash
->hlist_refcount
> 0) {
7294 struct swevent_hlist
*hlist
;
7296 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7298 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7300 mutex_unlock(&swhash
->hlist_mutex
);
7303 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7304 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7306 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7308 WARN_ON(!irqs_disabled());
7310 list_del_init(&cpuctx
->rotation_list
);
7313 static void __perf_event_exit_context(void *__info
)
7315 struct perf_event_context
*ctx
= __info
;
7316 struct perf_event
*event
, *tmp
;
7318 perf_pmu_rotate_stop(ctx
->pmu
);
7320 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
7321 __perf_remove_from_context(event
);
7322 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
7323 __perf_remove_from_context(event
);
7326 static void perf_event_exit_cpu_context(int cpu
)
7328 struct perf_event_context
*ctx
;
7332 idx
= srcu_read_lock(&pmus_srcu
);
7333 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7334 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
7336 mutex_lock(&ctx
->mutex
);
7337 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
7338 mutex_unlock(&ctx
->mutex
);
7340 srcu_read_unlock(&pmus_srcu
, idx
);
7343 static void perf_event_exit_cpu(int cpu
)
7345 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7347 mutex_lock(&swhash
->hlist_mutex
);
7348 swevent_hlist_release(swhash
);
7349 mutex_unlock(&swhash
->hlist_mutex
);
7351 perf_event_exit_cpu_context(cpu
);
7354 static inline void perf_event_exit_cpu(int cpu
) { }
7358 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
7362 for_each_online_cpu(cpu
)
7363 perf_event_exit_cpu(cpu
);
7369 * Run the perf reboot notifier at the very last possible moment so that
7370 * the generic watchdog code runs as long as possible.
7372 static struct notifier_block perf_reboot_notifier
= {
7373 .notifier_call
= perf_reboot
,
7374 .priority
= INT_MIN
,
7377 static int __cpuinit
7378 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
7380 unsigned int cpu
= (long)hcpu
;
7382 switch (action
& ~CPU_TASKS_FROZEN
) {
7384 case CPU_UP_PREPARE
:
7385 case CPU_DOWN_FAILED
:
7386 perf_event_init_cpu(cpu
);
7389 case CPU_UP_CANCELED
:
7390 case CPU_DOWN_PREPARE
:
7391 perf_event_exit_cpu(cpu
);
7401 void __init
perf_event_init(void)
7407 perf_event_init_all_cpus();
7408 init_srcu_struct(&pmus_srcu
);
7409 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
7410 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
7411 perf_pmu_register(&perf_task_clock
, NULL
, -1);
7413 perf_cpu_notifier(perf_cpu_notify
);
7414 register_reboot_notifier(&perf_reboot_notifier
);
7416 ret
= init_hw_breakpoint();
7417 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
7419 /* do not patch jump label more than once per second */
7420 jump_label_rate_limit(&perf_sched_events
, HZ
);
7423 * Build time assertion that we keep the data_head at the intended
7424 * location. IOW, validation we got the __reserved[] size right.
7426 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
7430 static int __init
perf_event_sysfs_init(void)
7435 mutex_lock(&pmus_lock
);
7437 ret
= bus_register(&pmu_bus
);
7441 list_for_each_entry(pmu
, &pmus
, entry
) {
7442 if (!pmu
->name
|| pmu
->type
< 0)
7445 ret
= pmu_dev_alloc(pmu
);
7446 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
7448 pmu_bus_running
= 1;
7452 mutex_unlock(&pmus_lock
);
7456 device_initcall(perf_event_sysfs_init
);
7458 #ifdef CONFIG_CGROUP_PERF
7459 static struct cgroup_subsys_state
*perf_cgroup_css_alloc(struct cgroup
*cont
)
7461 struct perf_cgroup
*jc
;
7463 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
7465 return ERR_PTR(-ENOMEM
);
7467 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
7470 return ERR_PTR(-ENOMEM
);
7476 static void perf_cgroup_css_free(struct cgroup
*cont
)
7478 struct perf_cgroup
*jc
;
7479 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
7480 struct perf_cgroup
, css
);
7481 free_percpu(jc
->info
);
7485 static int __perf_cgroup_move(void *info
)
7487 struct task_struct
*task
= info
;
7488 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
7492 static void perf_cgroup_attach(struct cgroup
*cgrp
, struct cgroup_taskset
*tset
)
7494 struct task_struct
*task
;
7496 cgroup_taskset_for_each(task
, cgrp
, tset
)
7497 task_function_call(task
, __perf_cgroup_move
, task
);
7500 static void perf_cgroup_exit(struct cgroup
*cgrp
, struct cgroup
*old_cgrp
,
7501 struct task_struct
*task
)
7504 * cgroup_exit() is called in the copy_process() failure path.
7505 * Ignore this case since the task hasn't ran yet, this avoids
7506 * trying to poke a half freed task state from generic code.
7508 if (!(task
->flags
& PF_EXITING
))
7511 task_function_call(task
, __perf_cgroup_move
, task
);
7514 struct cgroup_subsys perf_subsys
= {
7515 .name
= "perf_event",
7516 .subsys_id
= perf_subsys_id
,
7517 .css_alloc
= perf_cgroup_css_alloc
,
7518 .css_free
= perf_cgroup_css_free
,
7519 .exit
= perf_cgroup_exit
,
7520 .attach
= perf_cgroup_attach
,
7522 #endif /* CONFIG_CGROUP_PERF */