2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/sysfs.h>
22 #include <linux/dcache.h>
23 #include <linux/percpu.h>
24 #include <linux/ptrace.h>
25 #include <linux/reboot.h>
26 #include <linux/vmstat.h>
27 #include <linux/device.h>
28 #include <linux/export.h>
29 #include <linux/vmalloc.h>
30 #include <linux/hardirq.h>
31 #include <linux/rculist.h>
32 #include <linux/uaccess.h>
33 #include <linux/syscalls.h>
34 #include <linux/anon_inodes.h>
35 #include <linux/kernel_stat.h>
36 #include <linux/perf_event.h>
37 #include <linux/ftrace_event.h>
38 #include <linux/hw_breakpoint.h>
42 #include <asm/irq_regs.h>
44 struct remote_function_call
{
45 struct task_struct
*p
;
46 int (*func
)(void *info
);
51 static void remote_function(void *data
)
53 struct remote_function_call
*tfc
= data
;
54 struct task_struct
*p
= tfc
->p
;
58 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
62 tfc
->ret
= tfc
->func(tfc
->info
);
66 * task_function_call - call a function on the cpu on which a task runs
67 * @p: the task to evaluate
68 * @func: the function to be called
69 * @info: the function call argument
71 * Calls the function @func when the task is currently running. This might
72 * be on the current CPU, which just calls the function directly
74 * returns: @func return value, or
75 * -ESRCH - when the process isn't running
76 * -EAGAIN - when the process moved away
79 task_function_call(struct task_struct
*p
, int (*func
) (void *info
), void *info
)
81 struct remote_function_call data
= {
85 .ret
= -ESRCH
, /* No such (running) process */
89 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
95 * cpu_function_call - call a function on the cpu
96 * @func: the function to be called
97 * @info: the function call argument
99 * Calls the function @func on the remote cpu.
101 * returns: @func return value or -ENXIO when the cpu is offline
103 static int cpu_function_call(int cpu
, int (*func
) (void *info
), void *info
)
105 struct remote_function_call data
= {
109 .ret
= -ENXIO
, /* No such CPU */
112 smp_call_function_single(cpu
, remote_function
, &data
, 1);
117 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
118 PERF_FLAG_FD_OUTPUT |\
119 PERF_FLAG_PID_CGROUP)
122 EVENT_FLEXIBLE
= 0x1,
124 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
128 * perf_sched_events : >0 events exist
129 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
131 struct jump_label_key perf_sched_events __read_mostly
;
132 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
134 static atomic_t nr_mmap_events __read_mostly
;
135 static atomic_t nr_comm_events __read_mostly
;
136 static atomic_t nr_task_events __read_mostly
;
138 static LIST_HEAD(pmus
);
139 static DEFINE_MUTEX(pmus_lock
);
140 static struct srcu_struct pmus_srcu
;
143 * perf event paranoia level:
144 * -1 - not paranoid at all
145 * 0 - disallow raw tracepoint access for unpriv
146 * 1 - disallow cpu events for unpriv
147 * 2 - disallow kernel profiling for unpriv
149 int sysctl_perf_event_paranoid __read_mostly
= 1;
151 /* Minimum for 512 kiB + 1 user control page */
152 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
155 * max perf event sample rate
157 #define DEFAULT_MAX_SAMPLE_RATE 100000
158 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
159 static int max_samples_per_tick __read_mostly
=
160 DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
162 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
163 void __user
*buffer
, size_t *lenp
,
166 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
171 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
176 static atomic64_t perf_event_id
;
178 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
179 enum event_type_t event_type
);
181 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
182 enum event_type_t event_type
,
183 struct task_struct
*task
);
185 static void update_context_time(struct perf_event_context
*ctx
);
186 static u64
perf_event_time(struct perf_event
*event
);
188 static void ring_buffer_attach(struct perf_event
*event
,
189 struct ring_buffer
*rb
);
191 void __weak
perf_event_print_debug(void) { }
193 extern __weak
const char *perf_pmu_name(void)
198 static inline u64
perf_clock(void)
200 return local_clock();
203 static inline struct perf_cpu_context
*
204 __get_cpu_context(struct perf_event_context
*ctx
)
206 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
209 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
210 struct perf_event_context
*ctx
)
212 raw_spin_lock(&cpuctx
->ctx
.lock
);
214 raw_spin_lock(&ctx
->lock
);
217 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
218 struct perf_event_context
*ctx
)
221 raw_spin_unlock(&ctx
->lock
);
222 raw_spin_unlock(&cpuctx
->ctx
.lock
);
225 #ifdef CONFIG_CGROUP_PERF
228 * Must ensure cgroup is pinned (css_get) before calling
229 * this function. In other words, we cannot call this function
230 * if there is no cgroup event for the current CPU context.
232 static inline struct perf_cgroup
*
233 perf_cgroup_from_task(struct task_struct
*task
)
235 return container_of(task_subsys_state(task
, perf_subsys_id
),
236 struct perf_cgroup
, css
);
240 perf_cgroup_match(struct perf_event
*event
)
242 struct perf_event_context
*ctx
= event
->ctx
;
243 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
245 return !event
->cgrp
|| event
->cgrp
== cpuctx
->cgrp
;
248 static inline void perf_get_cgroup(struct perf_event
*event
)
250 css_get(&event
->cgrp
->css
);
253 static inline void perf_put_cgroup(struct perf_event
*event
)
255 css_put(&event
->cgrp
->css
);
258 static inline void perf_detach_cgroup(struct perf_event
*event
)
260 perf_put_cgroup(event
);
264 static inline int is_cgroup_event(struct perf_event
*event
)
266 return event
->cgrp
!= NULL
;
269 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
271 struct perf_cgroup_info
*t
;
273 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
277 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
279 struct perf_cgroup_info
*info
;
284 info
= this_cpu_ptr(cgrp
->info
);
286 info
->time
+= now
- info
->timestamp
;
287 info
->timestamp
= now
;
290 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
292 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
294 __update_cgrp_time(cgrp_out
);
297 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
299 struct perf_cgroup
*cgrp
;
302 * ensure we access cgroup data only when needed and
303 * when we know the cgroup is pinned (css_get)
305 if (!is_cgroup_event(event
))
308 cgrp
= perf_cgroup_from_task(current
);
310 * Do not update time when cgroup is not active
312 if (cgrp
== event
->cgrp
)
313 __update_cgrp_time(event
->cgrp
);
317 perf_cgroup_set_timestamp(struct task_struct
*task
,
318 struct perf_event_context
*ctx
)
320 struct perf_cgroup
*cgrp
;
321 struct perf_cgroup_info
*info
;
324 * ctx->lock held by caller
325 * ensure we do not access cgroup data
326 * unless we have the cgroup pinned (css_get)
328 if (!task
|| !ctx
->nr_cgroups
)
331 cgrp
= perf_cgroup_from_task(task
);
332 info
= this_cpu_ptr(cgrp
->info
);
333 info
->timestamp
= ctx
->timestamp
;
336 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
337 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
340 * reschedule events based on the cgroup constraint of task.
342 * mode SWOUT : schedule out everything
343 * mode SWIN : schedule in based on cgroup for next
345 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
347 struct perf_cpu_context
*cpuctx
;
352 * disable interrupts to avoid geting nr_cgroup
353 * changes via __perf_event_disable(). Also
356 local_irq_save(flags
);
359 * we reschedule only in the presence of cgroup
360 * constrained events.
364 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
365 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
368 * perf_cgroup_events says at least one
369 * context on this CPU has cgroup events.
371 * ctx->nr_cgroups reports the number of cgroup
372 * events for a context.
374 if (cpuctx
->ctx
.nr_cgroups
> 0) {
375 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
376 perf_pmu_disable(cpuctx
->ctx
.pmu
);
378 if (mode
& PERF_CGROUP_SWOUT
) {
379 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
381 * must not be done before ctxswout due
382 * to event_filter_match() in event_sched_out()
387 if (mode
& PERF_CGROUP_SWIN
) {
388 WARN_ON_ONCE(cpuctx
->cgrp
);
389 /* set cgrp before ctxsw in to
390 * allow event_filter_match() to not
391 * have to pass task around
393 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
394 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
396 perf_pmu_enable(cpuctx
->ctx
.pmu
);
397 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
403 local_irq_restore(flags
);
406 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
407 struct task_struct
*next
)
409 struct perf_cgroup
*cgrp1
;
410 struct perf_cgroup
*cgrp2
= NULL
;
413 * we come here when we know perf_cgroup_events > 0
415 cgrp1
= perf_cgroup_from_task(task
);
418 * next is NULL when called from perf_event_enable_on_exec()
419 * that will systematically cause a cgroup_switch()
422 cgrp2
= perf_cgroup_from_task(next
);
425 * only schedule out current cgroup events if we know
426 * that we are switching to a different cgroup. Otherwise,
427 * do no touch the cgroup events.
430 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
433 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
434 struct task_struct
*task
)
436 struct perf_cgroup
*cgrp1
;
437 struct perf_cgroup
*cgrp2
= NULL
;
440 * we come here when we know perf_cgroup_events > 0
442 cgrp1
= perf_cgroup_from_task(task
);
444 /* prev can never be NULL */
445 cgrp2
= perf_cgroup_from_task(prev
);
448 * only need to schedule in cgroup events if we are changing
449 * cgroup during ctxsw. Cgroup events were not scheduled
450 * out of ctxsw out if that was not the case.
453 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
456 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
457 struct perf_event_attr
*attr
,
458 struct perf_event
*group_leader
)
460 struct perf_cgroup
*cgrp
;
461 struct cgroup_subsys_state
*css
;
463 int ret
= 0, fput_needed
;
465 file
= fget_light(fd
, &fput_needed
);
469 css
= cgroup_css_from_dir(file
, perf_subsys_id
);
475 cgrp
= container_of(css
, struct perf_cgroup
, css
);
478 /* must be done before we fput() the file */
479 perf_get_cgroup(event
);
482 * all events in a group must monitor
483 * the same cgroup because a task belongs
484 * to only one perf cgroup at a time
486 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
487 perf_detach_cgroup(event
);
491 fput_light(file
, fput_needed
);
496 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
498 struct perf_cgroup_info
*t
;
499 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
500 event
->shadow_ctx_time
= now
- t
->timestamp
;
504 perf_cgroup_defer_enabled(struct perf_event
*event
)
507 * when the current task's perf cgroup does not match
508 * the event's, we need to remember to call the
509 * perf_mark_enable() function the first time a task with
510 * a matching perf cgroup is scheduled in.
512 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
513 event
->cgrp_defer_enabled
= 1;
517 perf_cgroup_mark_enabled(struct perf_event
*event
,
518 struct perf_event_context
*ctx
)
520 struct perf_event
*sub
;
521 u64 tstamp
= perf_event_time(event
);
523 if (!event
->cgrp_defer_enabled
)
526 event
->cgrp_defer_enabled
= 0;
528 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
529 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
530 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
531 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
532 sub
->cgrp_defer_enabled
= 0;
536 #else /* !CONFIG_CGROUP_PERF */
539 perf_cgroup_match(struct perf_event
*event
)
544 static inline void perf_detach_cgroup(struct perf_event
*event
)
547 static inline int is_cgroup_event(struct perf_event
*event
)
552 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
557 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
561 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
565 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
566 struct task_struct
*next
)
570 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
571 struct task_struct
*task
)
575 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
576 struct perf_event_attr
*attr
,
577 struct perf_event
*group_leader
)
583 perf_cgroup_set_timestamp(struct task_struct
*task
,
584 struct perf_event_context
*ctx
)
589 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
594 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
598 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
604 perf_cgroup_defer_enabled(struct perf_event
*event
)
609 perf_cgroup_mark_enabled(struct perf_event
*event
,
610 struct perf_event_context
*ctx
)
615 void perf_pmu_disable(struct pmu
*pmu
)
617 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
619 pmu
->pmu_disable(pmu
);
622 void perf_pmu_enable(struct pmu
*pmu
)
624 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
626 pmu
->pmu_enable(pmu
);
629 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
632 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
633 * because they're strictly cpu affine and rotate_start is called with IRQs
634 * disabled, while rotate_context is called from IRQ context.
636 static void perf_pmu_rotate_start(struct pmu
*pmu
)
638 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
639 struct list_head
*head
= &__get_cpu_var(rotation_list
);
641 WARN_ON(!irqs_disabled());
643 if (list_empty(&cpuctx
->rotation_list
))
644 list_add(&cpuctx
->rotation_list
, head
);
647 static void get_ctx(struct perf_event_context
*ctx
)
649 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
652 static void put_ctx(struct perf_event_context
*ctx
)
654 if (atomic_dec_and_test(&ctx
->refcount
)) {
656 put_ctx(ctx
->parent_ctx
);
658 put_task_struct(ctx
->task
);
659 kfree_rcu(ctx
, rcu_head
);
663 static void unclone_ctx(struct perf_event_context
*ctx
)
665 if (ctx
->parent_ctx
) {
666 put_ctx(ctx
->parent_ctx
);
667 ctx
->parent_ctx
= NULL
;
671 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
674 * only top level events have the pid namespace they were created in
677 event
= event
->parent
;
679 return task_tgid_nr_ns(p
, event
->ns
);
682 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
685 * only top level events have the pid namespace they were created in
688 event
= event
->parent
;
690 return task_pid_nr_ns(p
, event
->ns
);
694 * If we inherit events we want to return the parent event id
697 static u64
primary_event_id(struct perf_event
*event
)
702 id
= event
->parent
->id
;
708 * Get the perf_event_context for a task and lock it.
709 * This has to cope with with the fact that until it is locked,
710 * the context could get moved to another task.
712 static struct perf_event_context
*
713 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
715 struct perf_event_context
*ctx
;
719 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
722 * If this context is a clone of another, it might
723 * get swapped for another underneath us by
724 * perf_event_task_sched_out, though the
725 * rcu_read_lock() protects us from any context
726 * getting freed. Lock the context and check if it
727 * got swapped before we could get the lock, and retry
728 * if so. If we locked the right context, then it
729 * can't get swapped on us any more.
731 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
732 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
733 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
737 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
738 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
747 * Get the context for a task and increment its pin_count so it
748 * can't get swapped to another task. This also increments its
749 * reference count so that the context can't get freed.
751 static struct perf_event_context
*
752 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
754 struct perf_event_context
*ctx
;
757 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
760 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
765 static void perf_unpin_context(struct perf_event_context
*ctx
)
769 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
771 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
775 * Update the record of the current time in a context.
777 static void update_context_time(struct perf_event_context
*ctx
)
779 u64 now
= perf_clock();
781 ctx
->time
+= now
- ctx
->timestamp
;
782 ctx
->timestamp
= now
;
785 static u64
perf_event_time(struct perf_event
*event
)
787 struct perf_event_context
*ctx
= event
->ctx
;
789 if (is_cgroup_event(event
))
790 return perf_cgroup_event_time(event
);
792 return ctx
? ctx
->time
: 0;
796 * Update the total_time_enabled and total_time_running fields for a event.
797 * The caller of this function needs to hold the ctx->lock.
799 static void update_event_times(struct perf_event
*event
)
801 struct perf_event_context
*ctx
= event
->ctx
;
804 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
805 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
808 * in cgroup mode, time_enabled represents
809 * the time the event was enabled AND active
810 * tasks were in the monitored cgroup. This is
811 * independent of the activity of the context as
812 * there may be a mix of cgroup and non-cgroup events.
814 * That is why we treat cgroup events differently
817 if (is_cgroup_event(event
))
818 run_end
= perf_event_time(event
);
819 else if (ctx
->is_active
)
822 run_end
= event
->tstamp_stopped
;
824 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
826 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
827 run_end
= event
->tstamp_stopped
;
829 run_end
= perf_event_time(event
);
831 event
->total_time_running
= run_end
- event
->tstamp_running
;
836 * Update total_time_enabled and total_time_running for all events in a group.
838 static void update_group_times(struct perf_event
*leader
)
840 struct perf_event
*event
;
842 update_event_times(leader
);
843 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
844 update_event_times(event
);
847 static struct list_head
*
848 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
850 if (event
->attr
.pinned
)
851 return &ctx
->pinned_groups
;
853 return &ctx
->flexible_groups
;
857 * Add a event from the lists for its context.
858 * Must be called with ctx->mutex and ctx->lock held.
861 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
863 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
864 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
867 * If we're a stand alone event or group leader, we go to the context
868 * list, group events are kept attached to the group so that
869 * perf_group_detach can, at all times, locate all siblings.
871 if (event
->group_leader
== event
) {
872 struct list_head
*list
;
874 if (is_software_event(event
))
875 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
877 list
= ctx_group_list(event
, ctx
);
878 list_add_tail(&event
->group_entry
, list
);
881 if (is_cgroup_event(event
))
884 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
886 perf_pmu_rotate_start(ctx
->pmu
);
888 if (event
->attr
.inherit_stat
)
893 * Called at perf_event creation and when events are attached/detached from a
896 static void perf_event__read_size(struct perf_event
*event
)
898 int entry
= sizeof(u64
); /* value */
902 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
905 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
908 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
909 entry
+= sizeof(u64
);
911 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
912 nr
+= event
->group_leader
->nr_siblings
;
917 event
->read_size
= size
;
920 static void perf_event__header_size(struct perf_event
*event
)
922 struct perf_sample_data
*data
;
923 u64 sample_type
= event
->attr
.sample_type
;
926 perf_event__read_size(event
);
928 if (sample_type
& PERF_SAMPLE_IP
)
929 size
+= sizeof(data
->ip
);
931 if (sample_type
& PERF_SAMPLE_ADDR
)
932 size
+= sizeof(data
->addr
);
934 if (sample_type
& PERF_SAMPLE_PERIOD
)
935 size
+= sizeof(data
->period
);
937 if (sample_type
& PERF_SAMPLE_READ
)
938 size
+= event
->read_size
;
940 event
->header_size
= size
;
943 static void perf_event__id_header_size(struct perf_event
*event
)
945 struct perf_sample_data
*data
;
946 u64 sample_type
= event
->attr
.sample_type
;
949 if (sample_type
& PERF_SAMPLE_TID
)
950 size
+= sizeof(data
->tid_entry
);
952 if (sample_type
& PERF_SAMPLE_TIME
)
953 size
+= sizeof(data
->time
);
955 if (sample_type
& PERF_SAMPLE_ID
)
956 size
+= sizeof(data
->id
);
958 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
959 size
+= sizeof(data
->stream_id
);
961 if (sample_type
& PERF_SAMPLE_CPU
)
962 size
+= sizeof(data
->cpu_entry
);
964 event
->id_header_size
= size
;
967 static void perf_group_attach(struct perf_event
*event
)
969 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
972 * We can have double attach due to group movement in perf_event_open.
974 if (event
->attach_state
& PERF_ATTACH_GROUP
)
977 event
->attach_state
|= PERF_ATTACH_GROUP
;
979 if (group_leader
== event
)
982 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
983 !is_software_event(event
))
984 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
986 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
987 group_leader
->nr_siblings
++;
989 perf_event__header_size(group_leader
);
991 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
992 perf_event__header_size(pos
);
996 * Remove a event from the lists for its context.
997 * Must be called with ctx->mutex and ctx->lock held.
1000 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1002 struct perf_cpu_context
*cpuctx
;
1004 * We can have double detach due to exit/hot-unplug + close.
1006 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1009 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1011 if (is_cgroup_event(event
)) {
1013 cpuctx
= __get_cpu_context(ctx
);
1015 * if there are no more cgroup events
1016 * then cler cgrp to avoid stale pointer
1017 * in update_cgrp_time_from_cpuctx()
1019 if (!ctx
->nr_cgroups
)
1020 cpuctx
->cgrp
= NULL
;
1024 if (event
->attr
.inherit_stat
)
1027 list_del_rcu(&event
->event_entry
);
1029 if (event
->group_leader
== event
)
1030 list_del_init(&event
->group_entry
);
1032 update_group_times(event
);
1035 * If event was in error state, then keep it
1036 * that way, otherwise bogus counts will be
1037 * returned on read(). The only way to get out
1038 * of error state is by explicit re-enabling
1041 if (event
->state
> PERF_EVENT_STATE_OFF
)
1042 event
->state
= PERF_EVENT_STATE_OFF
;
1045 static void perf_group_detach(struct perf_event
*event
)
1047 struct perf_event
*sibling
, *tmp
;
1048 struct list_head
*list
= NULL
;
1051 * We can have double detach due to exit/hot-unplug + close.
1053 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1056 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1059 * If this is a sibling, remove it from its group.
1061 if (event
->group_leader
!= event
) {
1062 list_del_init(&event
->group_entry
);
1063 event
->group_leader
->nr_siblings
--;
1067 if (!list_empty(&event
->group_entry
))
1068 list
= &event
->group_entry
;
1071 * If this was a group event with sibling events then
1072 * upgrade the siblings to singleton events by adding them
1073 * to whatever list we are on.
1075 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1077 list_move_tail(&sibling
->group_entry
, list
);
1078 sibling
->group_leader
= sibling
;
1080 /* Inherit group flags from the previous leader */
1081 sibling
->group_flags
= event
->group_flags
;
1085 perf_event__header_size(event
->group_leader
);
1087 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1088 perf_event__header_size(tmp
);
1092 event_filter_match(struct perf_event
*event
)
1094 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1095 && perf_cgroup_match(event
);
1099 event_sched_out(struct perf_event
*event
,
1100 struct perf_cpu_context
*cpuctx
,
1101 struct perf_event_context
*ctx
)
1103 u64 tstamp
= perf_event_time(event
);
1106 * An event which could not be activated because of
1107 * filter mismatch still needs to have its timings
1108 * maintained, otherwise bogus information is return
1109 * via read() for time_enabled, time_running:
1111 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1112 && !event_filter_match(event
)) {
1113 delta
= tstamp
- event
->tstamp_stopped
;
1114 event
->tstamp_running
+= delta
;
1115 event
->tstamp_stopped
= tstamp
;
1118 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1121 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1122 if (event
->pending_disable
) {
1123 event
->pending_disable
= 0;
1124 event
->state
= PERF_EVENT_STATE_OFF
;
1126 event
->tstamp_stopped
= tstamp
;
1127 event
->pmu
->del(event
, 0);
1130 if (!is_software_event(event
))
1131 cpuctx
->active_oncpu
--;
1133 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1134 cpuctx
->exclusive
= 0;
1138 group_sched_out(struct perf_event
*group_event
,
1139 struct perf_cpu_context
*cpuctx
,
1140 struct perf_event_context
*ctx
)
1142 struct perf_event
*event
;
1143 int state
= group_event
->state
;
1145 event_sched_out(group_event
, cpuctx
, ctx
);
1148 * Schedule out siblings (if any):
1150 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1151 event_sched_out(event
, cpuctx
, ctx
);
1153 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1154 cpuctx
->exclusive
= 0;
1158 * Cross CPU call to remove a performance event
1160 * We disable the event on the hardware level first. After that we
1161 * remove it from the context list.
1163 static int __perf_remove_from_context(void *info
)
1165 struct perf_event
*event
= info
;
1166 struct perf_event_context
*ctx
= event
->ctx
;
1167 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1169 raw_spin_lock(&ctx
->lock
);
1170 event_sched_out(event
, cpuctx
, ctx
);
1171 list_del_event(event
, ctx
);
1172 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1174 cpuctx
->task_ctx
= NULL
;
1176 raw_spin_unlock(&ctx
->lock
);
1183 * Remove the event from a task's (or a CPU's) list of events.
1185 * CPU events are removed with a smp call. For task events we only
1186 * call when the task is on a CPU.
1188 * If event->ctx is a cloned context, callers must make sure that
1189 * every task struct that event->ctx->task could possibly point to
1190 * remains valid. This is OK when called from perf_release since
1191 * that only calls us on the top-level context, which can't be a clone.
1192 * When called from perf_event_exit_task, it's OK because the
1193 * context has been detached from its task.
1195 static void perf_remove_from_context(struct perf_event
*event
)
1197 struct perf_event_context
*ctx
= event
->ctx
;
1198 struct task_struct
*task
= ctx
->task
;
1200 lockdep_assert_held(&ctx
->mutex
);
1204 * Per cpu events are removed via an smp call and
1205 * the removal is always successful.
1207 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1212 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1215 raw_spin_lock_irq(&ctx
->lock
);
1217 * If we failed to find a running task, but find the context active now
1218 * that we've acquired the ctx->lock, retry.
1220 if (ctx
->is_active
) {
1221 raw_spin_unlock_irq(&ctx
->lock
);
1226 * Since the task isn't running, its safe to remove the event, us
1227 * holding the ctx->lock ensures the task won't get scheduled in.
1229 list_del_event(event
, ctx
);
1230 raw_spin_unlock_irq(&ctx
->lock
);
1234 * Cross CPU call to disable a performance event
1236 static int __perf_event_disable(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
);
1243 * If this is a per-task event, need to check whether this
1244 * event's task is the current task on this cpu.
1246 * Can trigger due to concurrent perf_event_context_sched_out()
1247 * flipping contexts around.
1249 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1252 raw_spin_lock(&ctx
->lock
);
1255 * If the event is on, turn it off.
1256 * If it is in error state, leave it in error state.
1258 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1259 update_context_time(ctx
);
1260 update_cgrp_time_from_event(event
);
1261 update_group_times(event
);
1262 if (event
== event
->group_leader
)
1263 group_sched_out(event
, cpuctx
, ctx
);
1265 event_sched_out(event
, cpuctx
, ctx
);
1266 event
->state
= PERF_EVENT_STATE_OFF
;
1269 raw_spin_unlock(&ctx
->lock
);
1277 * If event->ctx is a cloned context, callers must make sure that
1278 * every task struct that event->ctx->task could possibly point to
1279 * remains valid. This condition is satisifed when called through
1280 * perf_event_for_each_child or perf_event_for_each because they
1281 * hold the top-level event's child_mutex, so any descendant that
1282 * goes to exit will block in sync_child_event.
1283 * When called from perf_pending_event it's OK because event->ctx
1284 * is the current context on this CPU and preemption is disabled,
1285 * hence we can't get into perf_event_task_sched_out for this context.
1287 void perf_event_disable(struct perf_event
*event
)
1289 struct perf_event_context
*ctx
= event
->ctx
;
1290 struct task_struct
*task
= ctx
->task
;
1294 * Disable the event on the cpu that it's on
1296 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1301 if (!task_function_call(task
, __perf_event_disable
, event
))
1304 raw_spin_lock_irq(&ctx
->lock
);
1306 * If the event is still active, we need to retry the cross-call.
1308 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1309 raw_spin_unlock_irq(&ctx
->lock
);
1311 * Reload the task pointer, it might have been changed by
1312 * a concurrent perf_event_context_sched_out().
1319 * Since we have the lock this context can't be scheduled
1320 * in, so we can change the state safely.
1322 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1323 update_group_times(event
);
1324 event
->state
= PERF_EVENT_STATE_OFF
;
1326 raw_spin_unlock_irq(&ctx
->lock
);
1328 EXPORT_SYMBOL_GPL(perf_event_disable
);
1330 static void perf_set_shadow_time(struct perf_event
*event
,
1331 struct perf_event_context
*ctx
,
1335 * use the correct time source for the time snapshot
1337 * We could get by without this by leveraging the
1338 * fact that to get to this function, the caller
1339 * has most likely already called update_context_time()
1340 * and update_cgrp_time_xx() and thus both timestamp
1341 * are identical (or very close). Given that tstamp is,
1342 * already adjusted for cgroup, we could say that:
1343 * tstamp - ctx->timestamp
1345 * tstamp - cgrp->timestamp.
1347 * Then, in perf_output_read(), the calculation would
1348 * work with no changes because:
1349 * - event is guaranteed scheduled in
1350 * - no scheduled out in between
1351 * - thus the timestamp would be the same
1353 * But this is a bit hairy.
1355 * So instead, we have an explicit cgroup call to remain
1356 * within the time time source all along. We believe it
1357 * is cleaner and simpler to understand.
1359 if (is_cgroup_event(event
))
1360 perf_cgroup_set_shadow_time(event
, tstamp
);
1362 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1365 #define MAX_INTERRUPTS (~0ULL)
1367 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1370 event_sched_in(struct perf_event
*event
,
1371 struct perf_cpu_context
*cpuctx
,
1372 struct perf_event_context
*ctx
)
1374 u64 tstamp
= perf_event_time(event
);
1376 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1379 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1380 event
->oncpu
= smp_processor_id();
1383 * Unthrottle events, since we scheduled we might have missed several
1384 * ticks already, also for a heavily scheduling task there is little
1385 * guarantee it'll get a tick in a timely manner.
1387 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1388 perf_log_throttle(event
, 1);
1389 event
->hw
.interrupts
= 0;
1393 * The new state must be visible before we turn it on in the hardware:
1397 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1398 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1403 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1405 perf_set_shadow_time(event
, ctx
, tstamp
);
1407 if (!is_software_event(event
))
1408 cpuctx
->active_oncpu
++;
1411 if (event
->attr
.exclusive
)
1412 cpuctx
->exclusive
= 1;
1418 group_sched_in(struct perf_event
*group_event
,
1419 struct perf_cpu_context
*cpuctx
,
1420 struct perf_event_context
*ctx
)
1422 struct perf_event
*event
, *partial_group
= NULL
;
1423 struct pmu
*pmu
= group_event
->pmu
;
1424 u64 now
= ctx
->time
;
1425 bool simulate
= false;
1427 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1430 pmu
->start_txn(pmu
);
1432 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1433 pmu
->cancel_txn(pmu
);
1438 * Schedule in siblings as one group (if any):
1440 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1441 if (event_sched_in(event
, cpuctx
, ctx
)) {
1442 partial_group
= event
;
1447 if (!pmu
->commit_txn(pmu
))
1452 * Groups can be scheduled in as one unit only, so undo any
1453 * partial group before returning:
1454 * The events up to the failed event are scheduled out normally,
1455 * tstamp_stopped will be updated.
1457 * The failed events and the remaining siblings need to have
1458 * their timings updated as if they had gone thru event_sched_in()
1459 * and event_sched_out(). This is required to get consistent timings
1460 * across the group. This also takes care of the case where the group
1461 * could never be scheduled by ensuring tstamp_stopped is set to mark
1462 * the time the event was actually stopped, such that time delta
1463 * calculation in update_event_times() is correct.
1465 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1466 if (event
== partial_group
)
1470 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1471 event
->tstamp_stopped
= now
;
1473 event_sched_out(event
, cpuctx
, ctx
);
1476 event_sched_out(group_event
, cpuctx
, ctx
);
1478 pmu
->cancel_txn(pmu
);
1484 * Work out whether we can put this event group on the CPU now.
1486 static int group_can_go_on(struct perf_event
*event
,
1487 struct perf_cpu_context
*cpuctx
,
1491 * Groups consisting entirely of software events can always go on.
1493 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1496 * If an exclusive group is already on, no other hardware
1499 if (cpuctx
->exclusive
)
1502 * If this group is exclusive and there are already
1503 * events on the CPU, it can't go on.
1505 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1508 * Otherwise, try to add it if all previous groups were able
1514 static void add_event_to_ctx(struct perf_event
*event
,
1515 struct perf_event_context
*ctx
)
1517 u64 tstamp
= perf_event_time(event
);
1519 list_add_event(event
, ctx
);
1520 perf_group_attach(event
);
1521 event
->tstamp_enabled
= tstamp
;
1522 event
->tstamp_running
= tstamp
;
1523 event
->tstamp_stopped
= tstamp
;
1526 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
1528 ctx_sched_in(struct perf_event_context
*ctx
,
1529 struct perf_cpu_context
*cpuctx
,
1530 enum event_type_t event_type
,
1531 struct task_struct
*task
);
1533 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
1534 struct perf_event_context
*ctx
,
1535 struct task_struct
*task
)
1537 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
1539 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
1540 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
1542 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
1546 * Cross CPU call to install and enable a performance event
1548 * Must be called with ctx->mutex held
1550 static int __perf_install_in_context(void *info
)
1552 struct perf_event
*event
= info
;
1553 struct perf_event_context
*ctx
= event
->ctx
;
1554 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1555 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
1556 struct task_struct
*task
= current
;
1558 perf_ctx_lock(cpuctx
, task_ctx
);
1559 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1562 * If there was an active task_ctx schedule it out.
1565 task_ctx_sched_out(task_ctx
);
1568 * If the context we're installing events in is not the
1569 * active task_ctx, flip them.
1571 if (ctx
->task
&& task_ctx
!= ctx
) {
1573 raw_spin_unlock(&task_ctx
->lock
);
1574 raw_spin_lock(&ctx
->lock
);
1579 cpuctx
->task_ctx
= task_ctx
;
1580 task
= task_ctx
->task
;
1583 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
1585 update_context_time(ctx
);
1587 * update cgrp time only if current cgrp
1588 * matches event->cgrp. Must be done before
1589 * calling add_event_to_ctx()
1591 update_cgrp_time_from_event(event
);
1593 add_event_to_ctx(event
, ctx
);
1596 * Schedule everything back in
1598 perf_event_sched_in(cpuctx
, task_ctx
, task
);
1600 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1601 perf_ctx_unlock(cpuctx
, task_ctx
);
1607 * Attach a performance event to a context
1609 * First we add the event to the list with the hardware enable bit
1610 * in event->hw_config cleared.
1612 * If the event is attached to a task which is on a CPU we use a smp
1613 * call to enable it in the task context. The task might have been
1614 * scheduled away, but we check this in the smp call again.
1617 perf_install_in_context(struct perf_event_context
*ctx
,
1618 struct perf_event
*event
,
1621 struct task_struct
*task
= ctx
->task
;
1623 lockdep_assert_held(&ctx
->mutex
);
1629 * Per cpu events are installed via an smp call and
1630 * the install is always successful.
1632 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1637 if (!task_function_call(task
, __perf_install_in_context
, event
))
1640 raw_spin_lock_irq(&ctx
->lock
);
1642 * If we failed to find a running task, but find the context active now
1643 * that we've acquired the ctx->lock, retry.
1645 if (ctx
->is_active
) {
1646 raw_spin_unlock_irq(&ctx
->lock
);
1651 * Since the task isn't running, its safe to add the event, us holding
1652 * the ctx->lock ensures the task won't get scheduled in.
1654 add_event_to_ctx(event
, ctx
);
1655 raw_spin_unlock_irq(&ctx
->lock
);
1659 * Put a event into inactive state and update time fields.
1660 * Enabling the leader of a group effectively enables all
1661 * the group members that aren't explicitly disabled, so we
1662 * have to update their ->tstamp_enabled also.
1663 * Note: this works for group members as well as group leaders
1664 * since the non-leader members' sibling_lists will be empty.
1666 static void __perf_event_mark_enabled(struct perf_event
*event
,
1667 struct perf_event_context
*ctx
)
1669 struct perf_event
*sub
;
1670 u64 tstamp
= perf_event_time(event
);
1672 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1673 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1674 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1675 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1676 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1681 * Cross CPU call to enable a performance event
1683 static int __perf_event_enable(void *info
)
1685 struct perf_event
*event
= info
;
1686 struct perf_event_context
*ctx
= event
->ctx
;
1687 struct perf_event
*leader
= event
->group_leader
;
1688 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1691 if (WARN_ON_ONCE(!ctx
->is_active
))
1694 raw_spin_lock(&ctx
->lock
);
1695 update_context_time(ctx
);
1697 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1701 * set current task's cgroup time reference point
1703 perf_cgroup_set_timestamp(current
, ctx
);
1705 __perf_event_mark_enabled(event
, ctx
);
1707 if (!event_filter_match(event
)) {
1708 if (is_cgroup_event(event
))
1709 perf_cgroup_defer_enabled(event
);
1714 * If the event is in a group and isn't the group leader,
1715 * then don't put it on unless the group is on.
1717 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1720 if (!group_can_go_on(event
, cpuctx
, 1)) {
1723 if (event
== leader
)
1724 err
= group_sched_in(event
, cpuctx
, ctx
);
1726 err
= event_sched_in(event
, cpuctx
, ctx
);
1731 * If this event can't go on and it's part of a
1732 * group, then the whole group has to come off.
1734 if (leader
!= event
)
1735 group_sched_out(leader
, cpuctx
, ctx
);
1736 if (leader
->attr
.pinned
) {
1737 update_group_times(leader
);
1738 leader
->state
= PERF_EVENT_STATE_ERROR
;
1743 raw_spin_unlock(&ctx
->lock
);
1751 * If event->ctx is a cloned context, callers must make sure that
1752 * every task struct that event->ctx->task could possibly point to
1753 * remains valid. This condition is satisfied when called through
1754 * perf_event_for_each_child or perf_event_for_each as described
1755 * for perf_event_disable.
1757 void perf_event_enable(struct perf_event
*event
)
1759 struct perf_event_context
*ctx
= event
->ctx
;
1760 struct task_struct
*task
= ctx
->task
;
1764 * Enable the event on the cpu that it's on
1766 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
1770 raw_spin_lock_irq(&ctx
->lock
);
1771 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1775 * If the event is in error state, clear that first.
1776 * That way, if we see the event in error state below, we
1777 * know that it has gone back into error state, as distinct
1778 * from the task having been scheduled away before the
1779 * cross-call arrived.
1781 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1782 event
->state
= PERF_EVENT_STATE_OFF
;
1785 if (!ctx
->is_active
) {
1786 __perf_event_mark_enabled(event
, ctx
);
1790 raw_spin_unlock_irq(&ctx
->lock
);
1792 if (!task_function_call(task
, __perf_event_enable
, event
))
1795 raw_spin_lock_irq(&ctx
->lock
);
1798 * If the context is active and the event is still off,
1799 * we need to retry the cross-call.
1801 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
1803 * task could have been flipped by a concurrent
1804 * perf_event_context_sched_out()
1811 raw_spin_unlock_irq(&ctx
->lock
);
1813 EXPORT_SYMBOL_GPL(perf_event_enable
);
1815 int perf_event_refresh(struct perf_event
*event
, int refresh
)
1818 * not supported on inherited events
1820 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1823 atomic_add(refresh
, &event
->event_limit
);
1824 perf_event_enable(event
);
1828 EXPORT_SYMBOL_GPL(perf_event_refresh
);
1830 static void ctx_sched_out(struct perf_event_context
*ctx
,
1831 struct perf_cpu_context
*cpuctx
,
1832 enum event_type_t event_type
)
1834 struct perf_event
*event
;
1835 int is_active
= ctx
->is_active
;
1837 ctx
->is_active
&= ~event_type
;
1838 if (likely(!ctx
->nr_events
))
1841 update_context_time(ctx
);
1842 update_cgrp_time_from_cpuctx(cpuctx
);
1843 if (!ctx
->nr_active
)
1846 perf_pmu_disable(ctx
->pmu
);
1847 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
1848 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1849 group_sched_out(event
, cpuctx
, ctx
);
1852 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
1853 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1854 group_sched_out(event
, cpuctx
, ctx
);
1856 perf_pmu_enable(ctx
->pmu
);
1860 * Test whether two contexts are equivalent, i.e. whether they
1861 * have both been cloned from the same version of the same context
1862 * and they both have the same number of enabled events.
1863 * If the number of enabled events is the same, then the set
1864 * of enabled events should be the same, because these are both
1865 * inherited contexts, therefore we can't access individual events
1866 * in them directly with an fd; we can only enable/disable all
1867 * events via prctl, or enable/disable all events in a family
1868 * via ioctl, which will have the same effect on both contexts.
1870 static int context_equiv(struct perf_event_context
*ctx1
,
1871 struct perf_event_context
*ctx2
)
1873 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1874 && ctx1
->parent_gen
== ctx2
->parent_gen
1875 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1878 static void __perf_event_sync_stat(struct perf_event
*event
,
1879 struct perf_event
*next_event
)
1883 if (!event
->attr
.inherit_stat
)
1887 * Update the event value, we cannot use perf_event_read()
1888 * because we're in the middle of a context switch and have IRQs
1889 * disabled, which upsets smp_call_function_single(), however
1890 * we know the event must be on the current CPU, therefore we
1891 * don't need to use it.
1893 switch (event
->state
) {
1894 case PERF_EVENT_STATE_ACTIVE
:
1895 event
->pmu
->read(event
);
1898 case PERF_EVENT_STATE_INACTIVE
:
1899 update_event_times(event
);
1907 * In order to keep per-task stats reliable we need to flip the event
1908 * values when we flip the contexts.
1910 value
= local64_read(&next_event
->count
);
1911 value
= local64_xchg(&event
->count
, value
);
1912 local64_set(&next_event
->count
, value
);
1914 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1915 swap(event
->total_time_running
, next_event
->total_time_running
);
1918 * Since we swizzled the values, update the user visible data too.
1920 perf_event_update_userpage(event
);
1921 perf_event_update_userpage(next_event
);
1924 #define list_next_entry(pos, member) \
1925 list_entry(pos->member.next, typeof(*pos), member)
1927 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1928 struct perf_event_context
*next_ctx
)
1930 struct perf_event
*event
, *next_event
;
1935 update_context_time(ctx
);
1937 event
= list_first_entry(&ctx
->event_list
,
1938 struct perf_event
, event_entry
);
1940 next_event
= list_first_entry(&next_ctx
->event_list
,
1941 struct perf_event
, event_entry
);
1943 while (&event
->event_entry
!= &ctx
->event_list
&&
1944 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1946 __perf_event_sync_stat(event
, next_event
);
1948 event
= list_next_entry(event
, event_entry
);
1949 next_event
= list_next_entry(next_event
, event_entry
);
1953 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
1954 struct task_struct
*next
)
1956 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
1957 struct perf_event_context
*next_ctx
;
1958 struct perf_event_context
*parent
;
1959 struct perf_cpu_context
*cpuctx
;
1965 cpuctx
= __get_cpu_context(ctx
);
1966 if (!cpuctx
->task_ctx
)
1970 parent
= rcu_dereference(ctx
->parent_ctx
);
1971 next_ctx
= next
->perf_event_ctxp
[ctxn
];
1972 if (parent
&& next_ctx
&&
1973 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1975 * Looks like the two contexts are clones, so we might be
1976 * able to optimize the context switch. We lock both
1977 * contexts and check that they are clones under the
1978 * lock (including re-checking that neither has been
1979 * uncloned in the meantime). It doesn't matter which
1980 * order we take the locks because no other cpu could
1981 * be trying to lock both of these tasks.
1983 raw_spin_lock(&ctx
->lock
);
1984 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1985 if (context_equiv(ctx
, next_ctx
)) {
1987 * XXX do we need a memory barrier of sorts
1988 * wrt to rcu_dereference() of perf_event_ctxp
1990 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
1991 next
->perf_event_ctxp
[ctxn
] = ctx
;
1993 next_ctx
->task
= task
;
1996 perf_event_sync_stat(ctx
, next_ctx
);
1998 raw_spin_unlock(&next_ctx
->lock
);
1999 raw_spin_unlock(&ctx
->lock
);
2004 raw_spin_lock(&ctx
->lock
);
2005 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2006 cpuctx
->task_ctx
= NULL
;
2007 raw_spin_unlock(&ctx
->lock
);
2011 #define for_each_task_context_nr(ctxn) \
2012 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2015 * Called from scheduler to remove the events of the current task,
2016 * with interrupts disabled.
2018 * We stop each event and update the event value in event->count.
2020 * This does not protect us against NMI, but disable()
2021 * sets the disabled bit in the control field of event _before_
2022 * accessing the event control register. If a NMI hits, then it will
2023 * not restart the event.
2025 void __perf_event_task_sched_out(struct task_struct
*task
,
2026 struct task_struct
*next
)
2030 for_each_task_context_nr(ctxn
)
2031 perf_event_context_sched_out(task
, ctxn
, next
);
2034 * if cgroup events exist on this CPU, then we need
2035 * to check if we have to switch out PMU state.
2036 * cgroup event are system-wide mode only
2038 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2039 perf_cgroup_sched_out(task
, next
);
2042 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2044 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2046 if (!cpuctx
->task_ctx
)
2049 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2052 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2053 cpuctx
->task_ctx
= NULL
;
2057 * Called with IRQs disabled
2059 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2060 enum event_type_t event_type
)
2062 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2066 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2067 struct perf_cpu_context
*cpuctx
)
2069 struct perf_event
*event
;
2071 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2072 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2074 if (!event_filter_match(event
))
2077 /* may need to reset tstamp_enabled */
2078 if (is_cgroup_event(event
))
2079 perf_cgroup_mark_enabled(event
, ctx
);
2081 if (group_can_go_on(event
, cpuctx
, 1))
2082 group_sched_in(event
, cpuctx
, ctx
);
2085 * If this pinned group hasn't been scheduled,
2086 * put it in error state.
2088 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2089 update_group_times(event
);
2090 event
->state
= PERF_EVENT_STATE_ERROR
;
2096 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2097 struct perf_cpu_context
*cpuctx
)
2099 struct perf_event
*event
;
2102 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2103 /* Ignore events in OFF or ERROR state */
2104 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2107 * Listen to the 'cpu' scheduling filter constraint
2110 if (!event_filter_match(event
))
2113 /* may need to reset tstamp_enabled */
2114 if (is_cgroup_event(event
))
2115 perf_cgroup_mark_enabled(event
, ctx
);
2117 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2118 if (group_sched_in(event
, cpuctx
, ctx
))
2125 ctx_sched_in(struct perf_event_context
*ctx
,
2126 struct perf_cpu_context
*cpuctx
,
2127 enum event_type_t event_type
,
2128 struct task_struct
*task
)
2131 int is_active
= ctx
->is_active
;
2133 ctx
->is_active
|= event_type
;
2134 if (likely(!ctx
->nr_events
))
2138 ctx
->timestamp
= now
;
2139 perf_cgroup_set_timestamp(task
, ctx
);
2141 * First go through the list and put on any pinned groups
2142 * in order to give them the best chance of going on.
2144 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2145 ctx_pinned_sched_in(ctx
, cpuctx
);
2147 /* Then walk through the lower prio flexible groups */
2148 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2149 ctx_flexible_sched_in(ctx
, cpuctx
);
2152 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2153 enum event_type_t event_type
,
2154 struct task_struct
*task
)
2156 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2158 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2161 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2162 struct task_struct
*task
)
2164 struct perf_cpu_context
*cpuctx
;
2166 cpuctx
= __get_cpu_context(ctx
);
2167 if (cpuctx
->task_ctx
== ctx
)
2170 perf_ctx_lock(cpuctx
, ctx
);
2171 perf_pmu_disable(ctx
->pmu
);
2173 * We want to keep the following priority order:
2174 * cpu pinned (that don't need to move), task pinned,
2175 * cpu flexible, task flexible.
2177 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2179 perf_event_sched_in(cpuctx
, ctx
, task
);
2182 cpuctx
->task_ctx
= ctx
;
2184 perf_pmu_enable(ctx
->pmu
);
2185 perf_ctx_unlock(cpuctx
, ctx
);
2188 * Since these rotations are per-cpu, we need to ensure the
2189 * cpu-context we got scheduled on is actually rotating.
2191 perf_pmu_rotate_start(ctx
->pmu
);
2195 * Called from scheduler to add the events of the current task
2196 * with interrupts disabled.
2198 * We restore the event value and then enable it.
2200 * This does not protect us against NMI, but enable()
2201 * sets the enabled bit in the control field of event _before_
2202 * accessing the event control register. If a NMI hits, then it will
2203 * keep the event running.
2205 void __perf_event_task_sched_in(struct task_struct
*prev
,
2206 struct task_struct
*task
)
2208 struct perf_event_context
*ctx
;
2211 for_each_task_context_nr(ctxn
) {
2212 ctx
= task
->perf_event_ctxp
[ctxn
];
2216 perf_event_context_sched_in(ctx
, task
);
2219 * if cgroup events exist on this CPU, then we need
2220 * to check if we have to switch in PMU state.
2221 * cgroup event are system-wide mode only
2223 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2224 perf_cgroup_sched_in(prev
, task
);
2227 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2229 u64 frequency
= event
->attr
.sample_freq
;
2230 u64 sec
= NSEC_PER_SEC
;
2231 u64 divisor
, dividend
;
2233 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2235 count_fls
= fls64(count
);
2236 nsec_fls
= fls64(nsec
);
2237 frequency_fls
= fls64(frequency
);
2241 * We got @count in @nsec, with a target of sample_freq HZ
2242 * the target period becomes:
2245 * period = -------------------
2246 * @nsec * sample_freq
2251 * Reduce accuracy by one bit such that @a and @b converge
2252 * to a similar magnitude.
2254 #define REDUCE_FLS(a, b) \
2256 if (a##_fls > b##_fls) { \
2266 * Reduce accuracy until either term fits in a u64, then proceed with
2267 * the other, so that finally we can do a u64/u64 division.
2269 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2270 REDUCE_FLS(nsec
, frequency
);
2271 REDUCE_FLS(sec
, count
);
2274 if (count_fls
+ sec_fls
> 64) {
2275 divisor
= nsec
* frequency
;
2277 while (count_fls
+ sec_fls
> 64) {
2278 REDUCE_FLS(count
, sec
);
2282 dividend
= count
* sec
;
2284 dividend
= count
* sec
;
2286 while (nsec_fls
+ frequency_fls
> 64) {
2287 REDUCE_FLS(nsec
, frequency
);
2291 divisor
= nsec
* frequency
;
2297 return div64_u64(dividend
, divisor
);
2300 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2302 struct hw_perf_event
*hwc
= &event
->hw
;
2303 s64 period
, sample_period
;
2306 period
= perf_calculate_period(event
, nsec
, count
);
2308 delta
= (s64
)(period
- hwc
->sample_period
);
2309 delta
= (delta
+ 7) / 8; /* low pass filter */
2311 sample_period
= hwc
->sample_period
+ delta
;
2316 hwc
->sample_period
= sample_period
;
2318 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2319 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2320 local64_set(&hwc
->period_left
, 0);
2321 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2325 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
, u64 period
)
2327 struct perf_event
*event
;
2328 struct hw_perf_event
*hwc
;
2329 u64 interrupts
, now
;
2332 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2333 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2336 if (!event_filter_match(event
))
2341 interrupts
= hwc
->interrupts
;
2342 hwc
->interrupts
= 0;
2345 * unthrottle events on the tick
2347 if (interrupts
== MAX_INTERRUPTS
) {
2348 perf_log_throttle(event
, 1);
2349 event
->pmu
->start(event
, 0);
2352 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2355 event
->pmu
->read(event
);
2356 now
= local64_read(&event
->count
);
2357 delta
= now
- hwc
->freq_count_stamp
;
2358 hwc
->freq_count_stamp
= now
;
2361 perf_adjust_period(event
, period
, delta
);
2366 * Round-robin a context's events:
2368 static void rotate_ctx(struct perf_event_context
*ctx
)
2371 * Rotate the first entry last of non-pinned groups. Rotation might be
2372 * disabled by the inheritance code.
2374 if (!ctx
->rotate_disable
)
2375 list_rotate_left(&ctx
->flexible_groups
);
2379 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2380 * because they're strictly cpu affine and rotate_start is called with IRQs
2381 * disabled, while rotate_context is called from IRQ context.
2383 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2385 u64 interval
= (u64
)cpuctx
->jiffies_interval
* TICK_NSEC
;
2386 struct perf_event_context
*ctx
= NULL
;
2387 int rotate
= 0, remove
= 1;
2389 if (cpuctx
->ctx
.nr_events
) {
2391 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2395 ctx
= cpuctx
->task_ctx
;
2396 if (ctx
&& ctx
->nr_events
) {
2398 if (ctx
->nr_events
!= ctx
->nr_active
)
2402 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2403 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2404 perf_ctx_adjust_freq(&cpuctx
->ctx
, interval
);
2406 perf_ctx_adjust_freq(ctx
, interval
);
2411 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2413 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
2415 rotate_ctx(&cpuctx
->ctx
);
2419 perf_event_sched_in(cpuctx
, ctx
, current
);
2423 list_del_init(&cpuctx
->rotation_list
);
2425 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2426 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2429 void perf_event_task_tick(void)
2431 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2432 struct perf_cpu_context
*cpuctx
, *tmp
;
2434 WARN_ON(!irqs_disabled());
2436 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2437 if (cpuctx
->jiffies_interval
== 1 ||
2438 !(jiffies
% cpuctx
->jiffies_interval
))
2439 perf_rotate_context(cpuctx
);
2443 static int event_enable_on_exec(struct perf_event
*event
,
2444 struct perf_event_context
*ctx
)
2446 if (!event
->attr
.enable_on_exec
)
2449 event
->attr
.enable_on_exec
= 0;
2450 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2453 __perf_event_mark_enabled(event
, ctx
);
2459 * Enable all of a task's events that have been marked enable-on-exec.
2460 * This expects task == current.
2462 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2464 struct perf_event
*event
;
2465 unsigned long flags
;
2469 local_irq_save(flags
);
2470 if (!ctx
|| !ctx
->nr_events
)
2474 * We must ctxsw out cgroup events to avoid conflict
2475 * when invoking perf_task_event_sched_in() later on
2476 * in this function. Otherwise we end up trying to
2477 * ctxswin cgroup events which are already scheduled
2480 perf_cgroup_sched_out(current
, NULL
);
2482 raw_spin_lock(&ctx
->lock
);
2483 task_ctx_sched_out(ctx
);
2485 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2486 ret
= event_enable_on_exec(event
, ctx
);
2491 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2492 ret
= event_enable_on_exec(event
, ctx
);
2498 * Unclone this context if we enabled any event.
2503 raw_spin_unlock(&ctx
->lock
);
2506 * Also calls ctxswin for cgroup events, if any:
2508 perf_event_context_sched_in(ctx
, ctx
->task
);
2510 local_irq_restore(flags
);
2514 * Cross CPU call to read the hardware event
2516 static void __perf_event_read(void *info
)
2518 struct perf_event
*event
= info
;
2519 struct perf_event_context
*ctx
= event
->ctx
;
2520 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2523 * If this is a task context, we need to check whether it is
2524 * the current task context of this cpu. If not it has been
2525 * scheduled out before the smp call arrived. In that case
2526 * event->count would have been updated to a recent sample
2527 * when the event was scheduled out.
2529 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2532 raw_spin_lock(&ctx
->lock
);
2533 if (ctx
->is_active
) {
2534 update_context_time(ctx
);
2535 update_cgrp_time_from_event(event
);
2537 update_event_times(event
);
2538 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2539 event
->pmu
->read(event
);
2540 raw_spin_unlock(&ctx
->lock
);
2543 static inline u64
perf_event_count(struct perf_event
*event
)
2545 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2548 static u64
perf_event_read(struct perf_event
*event
)
2551 * If event is enabled and currently active on a CPU, update the
2552 * value in the event structure:
2554 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2555 smp_call_function_single(event
->oncpu
,
2556 __perf_event_read
, event
, 1);
2557 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2558 struct perf_event_context
*ctx
= event
->ctx
;
2559 unsigned long flags
;
2561 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2563 * may read while context is not active
2564 * (e.g., thread is blocked), in that case
2565 * we cannot update context time
2567 if (ctx
->is_active
) {
2568 update_context_time(ctx
);
2569 update_cgrp_time_from_event(event
);
2571 update_event_times(event
);
2572 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2575 return perf_event_count(event
);
2579 * Initialize the perf_event context in a task_struct:
2581 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2583 raw_spin_lock_init(&ctx
->lock
);
2584 mutex_init(&ctx
->mutex
);
2585 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2586 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2587 INIT_LIST_HEAD(&ctx
->event_list
);
2588 atomic_set(&ctx
->refcount
, 1);
2591 static struct perf_event_context
*
2592 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2594 struct perf_event_context
*ctx
;
2596 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2600 __perf_event_init_context(ctx
);
2603 get_task_struct(task
);
2610 static struct task_struct
*
2611 find_lively_task_by_vpid(pid_t vpid
)
2613 struct task_struct
*task
;
2620 task
= find_task_by_vpid(vpid
);
2622 get_task_struct(task
);
2626 return ERR_PTR(-ESRCH
);
2628 /* Reuse ptrace permission checks for now. */
2630 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2635 put_task_struct(task
);
2636 return ERR_PTR(err
);
2641 * Returns a matching context with refcount and pincount.
2643 static struct perf_event_context
*
2644 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2646 struct perf_event_context
*ctx
;
2647 struct perf_cpu_context
*cpuctx
;
2648 unsigned long flags
;
2652 /* Must be root to operate on a CPU event: */
2653 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2654 return ERR_PTR(-EACCES
);
2657 * We could be clever and allow to attach a event to an
2658 * offline CPU and activate it when the CPU comes up, but
2661 if (!cpu_online(cpu
))
2662 return ERR_PTR(-ENODEV
);
2664 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2673 ctxn
= pmu
->task_ctx_nr
;
2678 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2682 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2684 ctx
= alloc_perf_context(pmu
, task
);
2690 mutex_lock(&task
->perf_event_mutex
);
2692 * If it has already passed perf_event_exit_task().
2693 * we must see PF_EXITING, it takes this mutex too.
2695 if (task
->flags
& PF_EXITING
)
2697 else if (task
->perf_event_ctxp
[ctxn
])
2702 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2704 mutex_unlock(&task
->perf_event_mutex
);
2706 if (unlikely(err
)) {
2718 return ERR_PTR(err
);
2721 static void perf_event_free_filter(struct perf_event
*event
);
2723 static void free_event_rcu(struct rcu_head
*head
)
2725 struct perf_event
*event
;
2727 event
= container_of(head
, struct perf_event
, rcu_head
);
2729 put_pid_ns(event
->ns
);
2730 perf_event_free_filter(event
);
2734 static void ring_buffer_put(struct ring_buffer
*rb
);
2736 static void free_event(struct perf_event
*event
)
2738 irq_work_sync(&event
->pending
);
2740 if (!event
->parent
) {
2741 if (event
->attach_state
& PERF_ATTACH_TASK
)
2742 jump_label_dec(&perf_sched_events
);
2743 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2744 atomic_dec(&nr_mmap_events
);
2745 if (event
->attr
.comm
)
2746 atomic_dec(&nr_comm_events
);
2747 if (event
->attr
.task
)
2748 atomic_dec(&nr_task_events
);
2749 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2750 put_callchain_buffers();
2751 if (is_cgroup_event(event
)) {
2752 atomic_dec(&per_cpu(perf_cgroup_events
, event
->cpu
));
2753 jump_label_dec(&perf_sched_events
);
2758 ring_buffer_put(event
->rb
);
2762 if (is_cgroup_event(event
))
2763 perf_detach_cgroup(event
);
2766 event
->destroy(event
);
2769 put_ctx(event
->ctx
);
2771 call_rcu(&event
->rcu_head
, free_event_rcu
);
2774 int perf_event_release_kernel(struct perf_event
*event
)
2776 struct perf_event_context
*ctx
= event
->ctx
;
2778 WARN_ON_ONCE(ctx
->parent_ctx
);
2780 * There are two ways this annotation is useful:
2782 * 1) there is a lock recursion from perf_event_exit_task
2783 * see the comment there.
2785 * 2) there is a lock-inversion with mmap_sem through
2786 * perf_event_read_group(), which takes faults while
2787 * holding ctx->mutex, however this is called after
2788 * the last filedesc died, so there is no possibility
2789 * to trigger the AB-BA case.
2791 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2792 raw_spin_lock_irq(&ctx
->lock
);
2793 perf_group_detach(event
);
2794 raw_spin_unlock_irq(&ctx
->lock
);
2795 perf_remove_from_context(event
);
2796 mutex_unlock(&ctx
->mutex
);
2802 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2805 * Called when the last reference to the file is gone.
2807 static int perf_release(struct inode
*inode
, struct file
*file
)
2809 struct perf_event
*event
= file
->private_data
;
2810 struct task_struct
*owner
;
2812 file
->private_data
= NULL
;
2815 owner
= ACCESS_ONCE(event
->owner
);
2817 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2818 * !owner it means the list deletion is complete and we can indeed
2819 * free this event, otherwise we need to serialize on
2820 * owner->perf_event_mutex.
2822 smp_read_barrier_depends();
2825 * Since delayed_put_task_struct() also drops the last
2826 * task reference we can safely take a new reference
2827 * while holding the rcu_read_lock().
2829 get_task_struct(owner
);
2834 mutex_lock(&owner
->perf_event_mutex
);
2836 * We have to re-check the event->owner field, if it is cleared
2837 * we raced with perf_event_exit_task(), acquiring the mutex
2838 * ensured they're done, and we can proceed with freeing the
2842 list_del_init(&event
->owner_entry
);
2843 mutex_unlock(&owner
->perf_event_mutex
);
2844 put_task_struct(owner
);
2847 return perf_event_release_kernel(event
);
2850 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
2852 struct perf_event
*child
;
2858 mutex_lock(&event
->child_mutex
);
2859 total
+= perf_event_read(event
);
2860 *enabled
+= event
->total_time_enabled
+
2861 atomic64_read(&event
->child_total_time_enabled
);
2862 *running
+= event
->total_time_running
+
2863 atomic64_read(&event
->child_total_time_running
);
2865 list_for_each_entry(child
, &event
->child_list
, child_list
) {
2866 total
+= perf_event_read(child
);
2867 *enabled
+= child
->total_time_enabled
;
2868 *running
+= child
->total_time_running
;
2870 mutex_unlock(&event
->child_mutex
);
2874 EXPORT_SYMBOL_GPL(perf_event_read_value
);
2876 static int perf_event_read_group(struct perf_event
*event
,
2877 u64 read_format
, char __user
*buf
)
2879 struct perf_event
*leader
= event
->group_leader
, *sub
;
2880 int n
= 0, size
= 0, ret
= -EFAULT
;
2881 struct perf_event_context
*ctx
= leader
->ctx
;
2883 u64 count
, enabled
, running
;
2885 mutex_lock(&ctx
->mutex
);
2886 count
= perf_event_read_value(leader
, &enabled
, &running
);
2888 values
[n
++] = 1 + leader
->nr_siblings
;
2889 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2890 values
[n
++] = enabled
;
2891 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2892 values
[n
++] = running
;
2893 values
[n
++] = count
;
2894 if (read_format
& PERF_FORMAT_ID
)
2895 values
[n
++] = primary_event_id(leader
);
2897 size
= n
* sizeof(u64
);
2899 if (copy_to_user(buf
, values
, size
))
2904 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
2907 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
2908 if (read_format
& PERF_FORMAT_ID
)
2909 values
[n
++] = primary_event_id(sub
);
2911 size
= n
* sizeof(u64
);
2913 if (copy_to_user(buf
+ ret
, values
, size
)) {
2921 mutex_unlock(&ctx
->mutex
);
2926 static int perf_event_read_one(struct perf_event
*event
,
2927 u64 read_format
, char __user
*buf
)
2929 u64 enabled
, running
;
2933 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
2934 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2935 values
[n
++] = enabled
;
2936 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2937 values
[n
++] = running
;
2938 if (read_format
& PERF_FORMAT_ID
)
2939 values
[n
++] = primary_event_id(event
);
2941 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2944 return n
* sizeof(u64
);
2948 * Read the performance event - simple non blocking version for now
2951 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2953 u64 read_format
= event
->attr
.read_format
;
2957 * Return end-of-file for a read on a event that is in
2958 * error state (i.e. because it was pinned but it couldn't be
2959 * scheduled on to the CPU at some point).
2961 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2964 if (count
< event
->read_size
)
2967 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2968 if (read_format
& PERF_FORMAT_GROUP
)
2969 ret
= perf_event_read_group(event
, read_format
, buf
);
2971 ret
= perf_event_read_one(event
, read_format
, buf
);
2977 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2979 struct perf_event
*event
= file
->private_data
;
2981 return perf_read_hw(event
, buf
, count
);
2984 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2986 struct perf_event
*event
= file
->private_data
;
2987 struct ring_buffer
*rb
;
2988 unsigned int events
= POLL_HUP
;
2991 * Race between perf_event_set_output() and perf_poll(): perf_poll()
2992 * grabs the rb reference but perf_event_set_output() overrides it.
2993 * Here is the timeline for two threads T1, T2:
2994 * t0: T1, rb = rcu_dereference(event->rb)
2995 * t1: T2, old_rb = event->rb
2996 * t2: T2, event->rb = new rb
2997 * t3: T2, ring_buffer_detach(old_rb)
2998 * t4: T1, ring_buffer_attach(rb1)
2999 * t5: T1, poll_wait(event->waitq)
3001 * To avoid this problem, we grab mmap_mutex in perf_poll()
3002 * thereby ensuring that the assignment of the new ring buffer
3003 * and the detachment of the old buffer appear atomic to perf_poll()
3005 mutex_lock(&event
->mmap_mutex
);
3008 rb
= rcu_dereference(event
->rb
);
3010 ring_buffer_attach(event
, rb
);
3011 events
= atomic_xchg(&rb
->poll
, 0);
3015 mutex_unlock(&event
->mmap_mutex
);
3017 poll_wait(file
, &event
->waitq
, wait
);
3022 static void perf_event_reset(struct perf_event
*event
)
3024 (void)perf_event_read(event
);
3025 local64_set(&event
->count
, 0);
3026 perf_event_update_userpage(event
);
3030 * Holding the top-level event's child_mutex means that any
3031 * descendant process that has inherited this event will block
3032 * in sync_child_event if it goes to exit, thus satisfying the
3033 * task existence requirements of perf_event_enable/disable.
3035 static void perf_event_for_each_child(struct perf_event
*event
,
3036 void (*func
)(struct perf_event
*))
3038 struct perf_event
*child
;
3040 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3041 mutex_lock(&event
->child_mutex
);
3043 list_for_each_entry(child
, &event
->child_list
, child_list
)
3045 mutex_unlock(&event
->child_mutex
);
3048 static void perf_event_for_each(struct perf_event
*event
,
3049 void (*func
)(struct perf_event
*))
3051 struct perf_event_context
*ctx
= event
->ctx
;
3052 struct perf_event
*sibling
;
3054 WARN_ON_ONCE(ctx
->parent_ctx
);
3055 mutex_lock(&ctx
->mutex
);
3056 event
= event
->group_leader
;
3058 perf_event_for_each_child(event
, func
);
3060 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3061 perf_event_for_each_child(event
, func
);
3062 mutex_unlock(&ctx
->mutex
);
3065 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3067 struct perf_event_context
*ctx
= event
->ctx
;
3071 if (!is_sampling_event(event
))
3074 if (copy_from_user(&value
, arg
, sizeof(value
)))
3080 raw_spin_lock_irq(&ctx
->lock
);
3081 if (event
->attr
.freq
) {
3082 if (value
> sysctl_perf_event_sample_rate
) {
3087 event
->attr
.sample_freq
= value
;
3089 event
->attr
.sample_period
= value
;
3090 event
->hw
.sample_period
= value
;
3093 raw_spin_unlock_irq(&ctx
->lock
);
3098 static const struct file_operations perf_fops
;
3100 static struct perf_event
*perf_fget_light(int fd
, int *fput_needed
)
3104 file
= fget_light(fd
, fput_needed
);
3106 return ERR_PTR(-EBADF
);
3108 if (file
->f_op
!= &perf_fops
) {
3109 fput_light(file
, *fput_needed
);
3111 return ERR_PTR(-EBADF
);
3114 return file
->private_data
;
3117 static int perf_event_set_output(struct perf_event
*event
,
3118 struct perf_event
*output_event
);
3119 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3121 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3123 struct perf_event
*event
= file
->private_data
;
3124 void (*func
)(struct perf_event
*);
3128 case PERF_EVENT_IOC_ENABLE
:
3129 func
= perf_event_enable
;
3131 case PERF_EVENT_IOC_DISABLE
:
3132 func
= perf_event_disable
;
3134 case PERF_EVENT_IOC_RESET
:
3135 func
= perf_event_reset
;
3138 case PERF_EVENT_IOC_REFRESH
:
3139 return perf_event_refresh(event
, arg
);
3141 case PERF_EVENT_IOC_PERIOD
:
3142 return perf_event_period(event
, (u64 __user
*)arg
);
3144 case PERF_EVENT_IOC_SET_OUTPUT
:
3146 struct perf_event
*output_event
= NULL
;
3147 int fput_needed
= 0;
3151 output_event
= perf_fget_light(arg
, &fput_needed
);
3152 if (IS_ERR(output_event
))
3153 return PTR_ERR(output_event
);
3156 ret
= perf_event_set_output(event
, output_event
);
3158 fput_light(output_event
->filp
, fput_needed
);
3163 case PERF_EVENT_IOC_SET_FILTER
:
3164 return perf_event_set_filter(event
, (void __user
*)arg
);
3170 if (flags
& PERF_IOC_FLAG_GROUP
)
3171 perf_event_for_each(event
, func
);
3173 perf_event_for_each_child(event
, func
);
3178 int perf_event_task_enable(void)
3180 struct perf_event
*event
;
3182 mutex_lock(¤t
->perf_event_mutex
);
3183 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3184 perf_event_for_each_child(event
, perf_event_enable
);
3185 mutex_unlock(¤t
->perf_event_mutex
);
3190 int perf_event_task_disable(void)
3192 struct perf_event
*event
;
3194 mutex_lock(¤t
->perf_event_mutex
);
3195 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3196 perf_event_for_each_child(event
, perf_event_disable
);
3197 mutex_unlock(¤t
->perf_event_mutex
);
3202 #ifndef PERF_EVENT_INDEX_OFFSET
3203 # define PERF_EVENT_INDEX_OFFSET 0
3206 static int perf_event_index(struct perf_event
*event
)
3208 if (event
->hw
.state
& PERF_HES_STOPPED
)
3211 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3214 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
3217 static void calc_timer_values(struct perf_event
*event
,
3224 ctx_time
= event
->shadow_ctx_time
+ now
;
3225 *enabled
= ctx_time
- event
->tstamp_enabled
;
3226 *running
= ctx_time
- event
->tstamp_running
;
3230 * Callers need to ensure there can be no nesting of this function, otherwise
3231 * the seqlock logic goes bad. We can not serialize this because the arch
3232 * code calls this from NMI context.
3234 void perf_event_update_userpage(struct perf_event
*event
)
3236 struct perf_event_mmap_page
*userpg
;
3237 struct ring_buffer
*rb
;
3238 u64 enabled
, running
;
3242 * compute total_time_enabled, total_time_running
3243 * based on snapshot values taken when the event
3244 * was last scheduled in.
3246 * we cannot simply called update_context_time()
3247 * because of locking issue as we can be called in
3250 calc_timer_values(event
, &enabled
, &running
);
3251 rb
= rcu_dereference(event
->rb
);
3255 userpg
= rb
->user_page
;
3258 * Disable preemption so as to not let the corresponding user-space
3259 * spin too long if we get preempted.
3264 userpg
->index
= perf_event_index(event
);
3265 userpg
->offset
= perf_event_count(event
);
3266 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3267 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3269 userpg
->time_enabled
= enabled
+
3270 atomic64_read(&event
->child_total_time_enabled
);
3272 userpg
->time_running
= running
+
3273 atomic64_read(&event
->child_total_time_running
);
3282 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3284 struct perf_event
*event
= vma
->vm_file
->private_data
;
3285 struct ring_buffer
*rb
;
3286 int ret
= VM_FAULT_SIGBUS
;
3288 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3289 if (vmf
->pgoff
== 0)
3295 rb
= rcu_dereference(event
->rb
);
3299 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3302 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3306 get_page(vmf
->page
);
3307 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3308 vmf
->page
->index
= vmf
->pgoff
;
3317 static void ring_buffer_attach(struct perf_event
*event
,
3318 struct ring_buffer
*rb
)
3320 unsigned long flags
;
3322 if (!list_empty(&event
->rb_entry
))
3325 spin_lock_irqsave(&rb
->event_lock
, flags
);
3326 if (!list_empty(&event
->rb_entry
))
3329 list_add(&event
->rb_entry
, &rb
->event_list
);
3331 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3334 static void ring_buffer_detach(struct perf_event
*event
,
3335 struct ring_buffer
*rb
)
3337 unsigned long flags
;
3339 if (list_empty(&event
->rb_entry
))
3342 spin_lock_irqsave(&rb
->event_lock
, flags
);
3343 list_del_init(&event
->rb_entry
);
3344 wake_up_all(&event
->waitq
);
3345 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3348 static void ring_buffer_wakeup(struct perf_event
*event
)
3350 struct ring_buffer
*rb
;
3353 rb
= rcu_dereference(event
->rb
);
3354 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
3355 wake_up_all(&event
->waitq
);
3360 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3362 struct ring_buffer
*rb
;
3364 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3368 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3370 struct ring_buffer
*rb
;
3373 rb
= rcu_dereference(event
->rb
);
3375 if (!atomic_inc_not_zero(&rb
->refcount
))
3383 static void ring_buffer_put(struct ring_buffer
*rb
)
3385 struct perf_event
*event
, *n
;
3386 unsigned long flags
;
3388 if (!atomic_dec_and_test(&rb
->refcount
))
3391 spin_lock_irqsave(&rb
->event_lock
, flags
);
3392 list_for_each_entry_safe(event
, n
, &rb
->event_list
, rb_entry
) {
3393 list_del_init(&event
->rb_entry
);
3394 wake_up_all(&event
->waitq
);
3396 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3398 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3401 static void perf_mmap_open(struct vm_area_struct
*vma
)
3403 struct perf_event
*event
= vma
->vm_file
->private_data
;
3405 atomic_inc(&event
->mmap_count
);
3408 static void perf_mmap_close(struct vm_area_struct
*vma
)
3410 struct perf_event
*event
= vma
->vm_file
->private_data
;
3412 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3413 unsigned long size
= perf_data_size(event
->rb
);
3414 struct user_struct
*user
= event
->mmap_user
;
3415 struct ring_buffer
*rb
= event
->rb
;
3417 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3418 vma
->vm_mm
->pinned_vm
-= event
->mmap_locked
;
3419 rcu_assign_pointer(event
->rb
, NULL
);
3420 ring_buffer_detach(event
, rb
);
3421 mutex_unlock(&event
->mmap_mutex
);
3423 ring_buffer_put(rb
);
3428 static const struct vm_operations_struct perf_mmap_vmops
= {
3429 .open
= perf_mmap_open
,
3430 .close
= perf_mmap_close
,
3431 .fault
= perf_mmap_fault
,
3432 .page_mkwrite
= perf_mmap_fault
,
3435 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3437 struct perf_event
*event
= file
->private_data
;
3438 unsigned long user_locked
, user_lock_limit
;
3439 struct user_struct
*user
= current_user();
3440 unsigned long locked
, lock_limit
;
3441 struct ring_buffer
*rb
;
3442 unsigned long vma_size
;
3443 unsigned long nr_pages
;
3444 long user_extra
, extra
;
3445 int ret
= 0, flags
= 0;
3448 * Don't allow mmap() of inherited per-task counters. This would
3449 * create a performance issue due to all children writing to the
3452 if (event
->cpu
== -1 && event
->attr
.inherit
)
3455 if (!(vma
->vm_flags
& VM_SHARED
))
3458 vma_size
= vma
->vm_end
- vma
->vm_start
;
3459 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3462 * If we have rb pages ensure they're a power-of-two number, so we
3463 * can do bitmasks instead of modulo.
3465 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3468 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3471 if (vma
->vm_pgoff
!= 0)
3474 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3475 mutex_lock(&event
->mmap_mutex
);
3477 if (event
->rb
->nr_pages
== nr_pages
)
3478 atomic_inc(&event
->rb
->refcount
);
3484 user_extra
= nr_pages
+ 1;
3485 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3488 * Increase the limit linearly with more CPUs:
3490 user_lock_limit
*= num_online_cpus();
3492 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3495 if (user_locked
> user_lock_limit
)
3496 extra
= user_locked
- user_lock_limit
;
3498 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3499 lock_limit
>>= PAGE_SHIFT
;
3500 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
3502 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3503 !capable(CAP_IPC_LOCK
)) {
3510 if (vma
->vm_flags
& VM_WRITE
)
3511 flags
|= RING_BUFFER_WRITABLE
;
3513 rb
= rb_alloc(nr_pages
,
3514 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
3521 rcu_assign_pointer(event
->rb
, rb
);
3523 atomic_long_add(user_extra
, &user
->locked_vm
);
3524 event
->mmap_locked
= extra
;
3525 event
->mmap_user
= get_current_user();
3526 vma
->vm_mm
->pinned_vm
+= event
->mmap_locked
;
3530 atomic_inc(&event
->mmap_count
);
3531 mutex_unlock(&event
->mmap_mutex
);
3533 vma
->vm_flags
|= VM_RESERVED
;
3534 vma
->vm_ops
= &perf_mmap_vmops
;
3539 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3541 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3542 struct perf_event
*event
= filp
->private_data
;
3545 mutex_lock(&inode
->i_mutex
);
3546 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3547 mutex_unlock(&inode
->i_mutex
);
3555 static const struct file_operations perf_fops
= {
3556 .llseek
= no_llseek
,
3557 .release
= perf_release
,
3560 .unlocked_ioctl
= perf_ioctl
,
3561 .compat_ioctl
= perf_ioctl
,
3563 .fasync
= perf_fasync
,
3569 * If there's data, ensure we set the poll() state and publish everything
3570 * to user-space before waking everybody up.
3573 void perf_event_wakeup(struct perf_event
*event
)
3575 ring_buffer_wakeup(event
);
3577 if (event
->pending_kill
) {
3578 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3579 event
->pending_kill
= 0;
3583 static void perf_pending_event(struct irq_work
*entry
)
3585 struct perf_event
*event
= container_of(entry
,
3586 struct perf_event
, pending
);
3588 if (event
->pending_disable
) {
3589 event
->pending_disable
= 0;
3590 __perf_event_disable(event
);
3593 if (event
->pending_wakeup
) {
3594 event
->pending_wakeup
= 0;
3595 perf_event_wakeup(event
);
3600 * We assume there is only KVM supporting the callbacks.
3601 * Later on, we might change it to a list if there is
3602 * another virtualization implementation supporting the callbacks.
3604 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3606 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3608 perf_guest_cbs
= cbs
;
3611 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3613 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3615 perf_guest_cbs
= NULL
;
3618 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3620 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3621 struct perf_sample_data
*data
,
3622 struct perf_event
*event
)
3624 u64 sample_type
= event
->attr
.sample_type
;
3626 data
->type
= sample_type
;
3627 header
->size
+= event
->id_header_size
;
3629 if (sample_type
& PERF_SAMPLE_TID
) {
3630 /* namespace issues */
3631 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3632 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3635 if (sample_type
& PERF_SAMPLE_TIME
)
3636 data
->time
= perf_clock();
3638 if (sample_type
& PERF_SAMPLE_ID
)
3639 data
->id
= primary_event_id(event
);
3641 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3642 data
->stream_id
= event
->id
;
3644 if (sample_type
& PERF_SAMPLE_CPU
) {
3645 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3646 data
->cpu_entry
.reserved
= 0;
3650 void perf_event_header__init_id(struct perf_event_header
*header
,
3651 struct perf_sample_data
*data
,
3652 struct perf_event
*event
)
3654 if (event
->attr
.sample_id_all
)
3655 __perf_event_header__init_id(header
, data
, event
);
3658 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
3659 struct perf_sample_data
*data
)
3661 u64 sample_type
= data
->type
;
3663 if (sample_type
& PERF_SAMPLE_TID
)
3664 perf_output_put(handle
, data
->tid_entry
);
3666 if (sample_type
& PERF_SAMPLE_TIME
)
3667 perf_output_put(handle
, data
->time
);
3669 if (sample_type
& PERF_SAMPLE_ID
)
3670 perf_output_put(handle
, data
->id
);
3672 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3673 perf_output_put(handle
, data
->stream_id
);
3675 if (sample_type
& PERF_SAMPLE_CPU
)
3676 perf_output_put(handle
, data
->cpu_entry
);
3679 void perf_event__output_id_sample(struct perf_event
*event
,
3680 struct perf_output_handle
*handle
,
3681 struct perf_sample_data
*sample
)
3683 if (event
->attr
.sample_id_all
)
3684 __perf_event__output_id_sample(handle
, sample
);
3687 static void perf_output_read_one(struct perf_output_handle
*handle
,
3688 struct perf_event
*event
,
3689 u64 enabled
, u64 running
)
3691 u64 read_format
= event
->attr
.read_format
;
3695 values
[n
++] = perf_event_count(event
);
3696 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3697 values
[n
++] = enabled
+
3698 atomic64_read(&event
->child_total_time_enabled
);
3700 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3701 values
[n
++] = running
+
3702 atomic64_read(&event
->child_total_time_running
);
3704 if (read_format
& PERF_FORMAT_ID
)
3705 values
[n
++] = primary_event_id(event
);
3707 __output_copy(handle
, values
, n
* sizeof(u64
));
3711 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3713 static void perf_output_read_group(struct perf_output_handle
*handle
,
3714 struct perf_event
*event
,
3715 u64 enabled
, u64 running
)
3717 struct perf_event
*leader
= event
->group_leader
, *sub
;
3718 u64 read_format
= event
->attr
.read_format
;
3722 values
[n
++] = 1 + leader
->nr_siblings
;
3724 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3725 values
[n
++] = enabled
;
3727 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3728 values
[n
++] = running
;
3730 if (leader
!= event
)
3731 leader
->pmu
->read(leader
);
3733 values
[n
++] = perf_event_count(leader
);
3734 if (read_format
& PERF_FORMAT_ID
)
3735 values
[n
++] = primary_event_id(leader
);
3737 __output_copy(handle
, values
, n
* sizeof(u64
));
3739 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3743 sub
->pmu
->read(sub
);
3745 values
[n
++] = perf_event_count(sub
);
3746 if (read_format
& PERF_FORMAT_ID
)
3747 values
[n
++] = primary_event_id(sub
);
3749 __output_copy(handle
, values
, n
* sizeof(u64
));
3753 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
3754 PERF_FORMAT_TOTAL_TIME_RUNNING)
3756 static void perf_output_read(struct perf_output_handle
*handle
,
3757 struct perf_event
*event
)
3759 u64 enabled
= 0, running
= 0;
3760 u64 read_format
= event
->attr
.read_format
;
3763 * compute total_time_enabled, total_time_running
3764 * based on snapshot values taken when the event
3765 * was last scheduled in.
3767 * we cannot simply called update_context_time()
3768 * because of locking issue as we are called in
3771 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
3772 calc_timer_values(event
, &enabled
, &running
);
3774 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3775 perf_output_read_group(handle
, event
, enabled
, running
);
3777 perf_output_read_one(handle
, event
, enabled
, running
);
3780 void perf_output_sample(struct perf_output_handle
*handle
,
3781 struct perf_event_header
*header
,
3782 struct perf_sample_data
*data
,
3783 struct perf_event
*event
)
3785 u64 sample_type
= data
->type
;
3787 perf_output_put(handle
, *header
);
3789 if (sample_type
& PERF_SAMPLE_IP
)
3790 perf_output_put(handle
, data
->ip
);
3792 if (sample_type
& PERF_SAMPLE_TID
)
3793 perf_output_put(handle
, data
->tid_entry
);
3795 if (sample_type
& PERF_SAMPLE_TIME
)
3796 perf_output_put(handle
, data
->time
);
3798 if (sample_type
& PERF_SAMPLE_ADDR
)
3799 perf_output_put(handle
, data
->addr
);
3801 if (sample_type
& PERF_SAMPLE_ID
)
3802 perf_output_put(handle
, data
->id
);
3804 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3805 perf_output_put(handle
, data
->stream_id
);
3807 if (sample_type
& PERF_SAMPLE_CPU
)
3808 perf_output_put(handle
, data
->cpu_entry
);
3810 if (sample_type
& PERF_SAMPLE_PERIOD
)
3811 perf_output_put(handle
, data
->period
);
3813 if (sample_type
& PERF_SAMPLE_READ
)
3814 perf_output_read(handle
, event
);
3816 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3817 if (data
->callchain
) {
3820 if (data
->callchain
)
3821 size
+= data
->callchain
->nr
;
3823 size
*= sizeof(u64
);
3825 __output_copy(handle
, data
->callchain
, size
);
3828 perf_output_put(handle
, nr
);
3832 if (sample_type
& PERF_SAMPLE_RAW
) {
3834 perf_output_put(handle
, data
->raw
->size
);
3835 __output_copy(handle
, data
->raw
->data
,
3842 .size
= sizeof(u32
),
3845 perf_output_put(handle
, raw
);
3849 if (!event
->attr
.watermark
) {
3850 int wakeup_events
= event
->attr
.wakeup_events
;
3852 if (wakeup_events
) {
3853 struct ring_buffer
*rb
= handle
->rb
;
3854 int events
= local_inc_return(&rb
->events
);
3856 if (events
>= wakeup_events
) {
3857 local_sub(wakeup_events
, &rb
->events
);
3858 local_inc(&rb
->wakeup
);
3864 void perf_prepare_sample(struct perf_event_header
*header
,
3865 struct perf_sample_data
*data
,
3866 struct perf_event
*event
,
3867 struct pt_regs
*regs
)
3869 u64 sample_type
= event
->attr
.sample_type
;
3871 header
->type
= PERF_RECORD_SAMPLE
;
3872 header
->size
= sizeof(*header
) + event
->header_size
;
3875 header
->misc
|= perf_misc_flags(regs
);
3877 __perf_event_header__init_id(header
, data
, event
);
3879 if (sample_type
& PERF_SAMPLE_IP
)
3880 data
->ip
= perf_instruction_pointer(regs
);
3882 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3885 data
->callchain
= perf_callchain(regs
);
3887 if (data
->callchain
)
3888 size
+= data
->callchain
->nr
;
3890 header
->size
+= size
* sizeof(u64
);
3893 if (sample_type
& PERF_SAMPLE_RAW
) {
3894 int size
= sizeof(u32
);
3897 size
+= data
->raw
->size
;
3899 size
+= sizeof(u32
);
3901 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3902 header
->size
+= size
;
3906 static void perf_event_output(struct perf_event
*event
,
3907 struct perf_sample_data
*data
,
3908 struct pt_regs
*regs
)
3910 struct perf_output_handle handle
;
3911 struct perf_event_header header
;
3913 /* protect the callchain buffers */
3916 perf_prepare_sample(&header
, data
, event
, regs
);
3918 if (perf_output_begin(&handle
, event
, header
.size
))
3921 perf_output_sample(&handle
, &header
, data
, event
);
3923 perf_output_end(&handle
);
3933 struct perf_read_event
{
3934 struct perf_event_header header
;
3941 perf_event_read_event(struct perf_event
*event
,
3942 struct task_struct
*task
)
3944 struct perf_output_handle handle
;
3945 struct perf_sample_data sample
;
3946 struct perf_read_event read_event
= {
3948 .type
= PERF_RECORD_READ
,
3950 .size
= sizeof(read_event
) + event
->read_size
,
3952 .pid
= perf_event_pid(event
, task
),
3953 .tid
= perf_event_tid(event
, task
),
3957 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
3958 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
3962 perf_output_put(&handle
, read_event
);
3963 perf_output_read(&handle
, event
);
3964 perf_event__output_id_sample(event
, &handle
, &sample
);
3966 perf_output_end(&handle
);
3970 * task tracking -- fork/exit
3972 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
3975 struct perf_task_event
{
3976 struct task_struct
*task
;
3977 struct perf_event_context
*task_ctx
;
3980 struct perf_event_header header
;
3990 static void perf_event_task_output(struct perf_event
*event
,
3991 struct perf_task_event
*task_event
)
3993 struct perf_output_handle handle
;
3994 struct perf_sample_data sample
;
3995 struct task_struct
*task
= task_event
->task
;
3996 int ret
, size
= task_event
->event_id
.header
.size
;
3998 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4000 ret
= perf_output_begin(&handle
, event
,
4001 task_event
->event_id
.header
.size
);
4005 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4006 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4008 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4009 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4011 perf_output_put(&handle
, task_event
->event_id
);
4013 perf_event__output_id_sample(event
, &handle
, &sample
);
4015 perf_output_end(&handle
);
4017 task_event
->event_id
.header
.size
= size
;
4020 static int perf_event_task_match(struct perf_event
*event
)
4022 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4025 if (!event_filter_match(event
))
4028 if (event
->attr
.comm
|| event
->attr
.mmap
||
4029 event
->attr
.mmap_data
|| event
->attr
.task
)
4035 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
4036 struct perf_task_event
*task_event
)
4038 struct perf_event
*event
;
4040 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4041 if (perf_event_task_match(event
))
4042 perf_event_task_output(event
, task_event
);
4046 static void perf_event_task_event(struct perf_task_event
*task_event
)
4048 struct perf_cpu_context
*cpuctx
;
4049 struct perf_event_context
*ctx
;
4054 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4055 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4056 if (cpuctx
->active_pmu
!= pmu
)
4058 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
4060 ctx
= task_event
->task_ctx
;
4062 ctxn
= pmu
->task_ctx_nr
;
4065 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4068 perf_event_task_ctx(ctx
, task_event
);
4070 put_cpu_ptr(pmu
->pmu_cpu_context
);
4075 static void perf_event_task(struct task_struct
*task
,
4076 struct perf_event_context
*task_ctx
,
4079 struct perf_task_event task_event
;
4081 if (!atomic_read(&nr_comm_events
) &&
4082 !atomic_read(&nr_mmap_events
) &&
4083 !atomic_read(&nr_task_events
))
4086 task_event
= (struct perf_task_event
){
4088 .task_ctx
= task_ctx
,
4091 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4093 .size
= sizeof(task_event
.event_id
),
4099 .time
= perf_clock(),
4103 perf_event_task_event(&task_event
);
4106 void perf_event_fork(struct task_struct
*task
)
4108 perf_event_task(task
, NULL
, 1);
4115 struct perf_comm_event
{
4116 struct task_struct
*task
;
4121 struct perf_event_header header
;
4128 static void perf_event_comm_output(struct perf_event
*event
,
4129 struct perf_comm_event
*comm_event
)
4131 struct perf_output_handle handle
;
4132 struct perf_sample_data sample
;
4133 int size
= comm_event
->event_id
.header
.size
;
4136 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4137 ret
= perf_output_begin(&handle
, event
,
4138 comm_event
->event_id
.header
.size
);
4143 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4144 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4146 perf_output_put(&handle
, comm_event
->event_id
);
4147 __output_copy(&handle
, comm_event
->comm
,
4148 comm_event
->comm_size
);
4150 perf_event__output_id_sample(event
, &handle
, &sample
);
4152 perf_output_end(&handle
);
4154 comm_event
->event_id
.header
.size
= size
;
4157 static int perf_event_comm_match(struct perf_event
*event
)
4159 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4162 if (!event_filter_match(event
))
4165 if (event
->attr
.comm
)
4171 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4172 struct perf_comm_event
*comm_event
)
4174 struct perf_event
*event
;
4176 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4177 if (perf_event_comm_match(event
))
4178 perf_event_comm_output(event
, comm_event
);
4182 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4184 struct perf_cpu_context
*cpuctx
;
4185 struct perf_event_context
*ctx
;
4186 char comm
[TASK_COMM_LEN
];
4191 memset(comm
, 0, sizeof(comm
));
4192 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4193 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4195 comm_event
->comm
= comm
;
4196 comm_event
->comm_size
= size
;
4198 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4200 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4201 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4202 if (cpuctx
->active_pmu
!= pmu
)
4204 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4206 ctxn
= pmu
->task_ctx_nr
;
4210 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4212 perf_event_comm_ctx(ctx
, comm_event
);
4214 put_cpu_ptr(pmu
->pmu_cpu_context
);
4219 void perf_event_comm(struct task_struct
*task
)
4221 struct perf_comm_event comm_event
;
4222 struct perf_event_context
*ctx
;
4225 for_each_task_context_nr(ctxn
) {
4226 ctx
= task
->perf_event_ctxp
[ctxn
];
4230 perf_event_enable_on_exec(ctx
);
4233 if (!atomic_read(&nr_comm_events
))
4236 comm_event
= (struct perf_comm_event
){
4242 .type
= PERF_RECORD_COMM
,
4251 perf_event_comm_event(&comm_event
);
4258 struct perf_mmap_event
{
4259 struct vm_area_struct
*vma
;
4261 const char *file_name
;
4265 struct perf_event_header header
;
4275 static void perf_event_mmap_output(struct perf_event
*event
,
4276 struct perf_mmap_event
*mmap_event
)
4278 struct perf_output_handle handle
;
4279 struct perf_sample_data sample
;
4280 int size
= mmap_event
->event_id
.header
.size
;
4283 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4284 ret
= perf_output_begin(&handle
, event
,
4285 mmap_event
->event_id
.header
.size
);
4289 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4290 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4292 perf_output_put(&handle
, mmap_event
->event_id
);
4293 __output_copy(&handle
, mmap_event
->file_name
,
4294 mmap_event
->file_size
);
4296 perf_event__output_id_sample(event
, &handle
, &sample
);
4298 perf_output_end(&handle
);
4300 mmap_event
->event_id
.header
.size
= size
;
4303 static int perf_event_mmap_match(struct perf_event
*event
,
4304 struct perf_mmap_event
*mmap_event
,
4307 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4310 if (!event_filter_match(event
))
4313 if ((!executable
&& event
->attr
.mmap_data
) ||
4314 (executable
&& event
->attr
.mmap
))
4320 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4321 struct perf_mmap_event
*mmap_event
,
4324 struct perf_event
*event
;
4326 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4327 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4328 perf_event_mmap_output(event
, mmap_event
);
4332 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4334 struct perf_cpu_context
*cpuctx
;
4335 struct perf_event_context
*ctx
;
4336 struct vm_area_struct
*vma
= mmap_event
->vma
;
4337 struct file
*file
= vma
->vm_file
;
4345 memset(tmp
, 0, sizeof(tmp
));
4349 * d_path works from the end of the rb backwards, so we
4350 * need to add enough zero bytes after the string to handle
4351 * the 64bit alignment we do later.
4353 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4355 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4358 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4360 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4364 if (arch_vma_name(mmap_event
->vma
)) {
4365 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4371 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4373 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4374 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4375 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4377 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4378 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4379 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4383 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4388 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4390 mmap_event
->file_name
= name
;
4391 mmap_event
->file_size
= size
;
4393 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4396 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4397 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4398 if (cpuctx
->active_pmu
!= pmu
)
4400 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4401 vma
->vm_flags
& VM_EXEC
);
4403 ctxn
= pmu
->task_ctx_nr
;
4407 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4409 perf_event_mmap_ctx(ctx
, mmap_event
,
4410 vma
->vm_flags
& VM_EXEC
);
4413 put_cpu_ptr(pmu
->pmu_cpu_context
);
4420 void perf_event_mmap(struct vm_area_struct
*vma
)
4422 struct perf_mmap_event mmap_event
;
4424 if (!atomic_read(&nr_mmap_events
))
4427 mmap_event
= (struct perf_mmap_event
){
4433 .type
= PERF_RECORD_MMAP
,
4434 .misc
= PERF_RECORD_MISC_USER
,
4439 .start
= vma
->vm_start
,
4440 .len
= vma
->vm_end
- vma
->vm_start
,
4441 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4445 perf_event_mmap_event(&mmap_event
);
4449 * IRQ throttle logging
4452 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4454 struct perf_output_handle handle
;
4455 struct perf_sample_data sample
;
4459 struct perf_event_header header
;
4463 } throttle_event
= {
4465 .type
= PERF_RECORD_THROTTLE
,
4467 .size
= sizeof(throttle_event
),
4469 .time
= perf_clock(),
4470 .id
= primary_event_id(event
),
4471 .stream_id
= event
->id
,
4475 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4477 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4479 ret
= perf_output_begin(&handle
, event
,
4480 throttle_event
.header
.size
);
4484 perf_output_put(&handle
, throttle_event
);
4485 perf_event__output_id_sample(event
, &handle
, &sample
);
4486 perf_output_end(&handle
);
4490 * Generic event overflow handling, sampling.
4493 static int __perf_event_overflow(struct perf_event
*event
,
4494 int throttle
, struct perf_sample_data
*data
,
4495 struct pt_regs
*regs
)
4497 int events
= atomic_read(&event
->event_limit
);
4498 struct hw_perf_event
*hwc
= &event
->hw
;
4502 * Non-sampling counters might still use the PMI to fold short
4503 * hardware counters, ignore those.
4505 if (unlikely(!is_sampling_event(event
)))
4508 if (unlikely(hwc
->interrupts
>= max_samples_per_tick
)) {
4510 hwc
->interrupts
= MAX_INTERRUPTS
;
4511 perf_log_throttle(event
, 0);
4517 if (event
->attr
.freq
) {
4518 u64 now
= perf_clock();
4519 s64 delta
= now
- hwc
->freq_time_stamp
;
4521 hwc
->freq_time_stamp
= now
;
4523 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4524 perf_adjust_period(event
, delta
, hwc
->last_period
);
4528 * XXX event_limit might not quite work as expected on inherited
4532 event
->pending_kill
= POLL_IN
;
4533 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4535 event
->pending_kill
= POLL_HUP
;
4536 event
->pending_disable
= 1;
4537 irq_work_queue(&event
->pending
);
4540 if (event
->overflow_handler
)
4541 event
->overflow_handler(event
, data
, regs
);
4543 perf_event_output(event
, data
, regs
);
4545 if (event
->fasync
&& event
->pending_kill
) {
4546 event
->pending_wakeup
= 1;
4547 irq_work_queue(&event
->pending
);
4553 int perf_event_overflow(struct perf_event
*event
,
4554 struct perf_sample_data
*data
,
4555 struct pt_regs
*regs
)
4557 return __perf_event_overflow(event
, 1, data
, regs
);
4561 * Generic software event infrastructure
4564 struct swevent_htable
{
4565 struct swevent_hlist
*swevent_hlist
;
4566 struct mutex hlist_mutex
;
4569 /* Recursion avoidance in each contexts */
4570 int recursion
[PERF_NR_CONTEXTS
];
4573 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
4576 * We directly increment event->count and keep a second value in
4577 * event->hw.period_left to count intervals. This period event
4578 * is kept in the range [-sample_period, 0] so that we can use the
4582 static u64
perf_swevent_set_period(struct perf_event
*event
)
4584 struct hw_perf_event
*hwc
= &event
->hw
;
4585 u64 period
= hwc
->last_period
;
4589 hwc
->last_period
= hwc
->sample_period
;
4592 old
= val
= local64_read(&hwc
->period_left
);
4596 nr
= div64_u64(period
+ val
, period
);
4597 offset
= nr
* period
;
4599 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
4605 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
4606 struct perf_sample_data
*data
,
4607 struct pt_regs
*regs
)
4609 struct hw_perf_event
*hwc
= &event
->hw
;
4613 overflow
= perf_swevent_set_period(event
);
4615 if (hwc
->interrupts
== MAX_INTERRUPTS
)
4618 for (; overflow
; overflow
--) {
4619 if (__perf_event_overflow(event
, throttle
,
4622 * We inhibit the overflow from happening when
4623 * hwc->interrupts == MAX_INTERRUPTS.
4631 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
4632 struct perf_sample_data
*data
,
4633 struct pt_regs
*regs
)
4635 struct hw_perf_event
*hwc
= &event
->hw
;
4637 local64_add(nr
, &event
->count
);
4642 if (!is_sampling_event(event
))
4645 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
4647 return perf_swevent_overflow(event
, 1, data
, regs
);
4649 data
->period
= event
->hw
.last_period
;
4651 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
4652 return perf_swevent_overflow(event
, 1, data
, regs
);
4654 if (local64_add_negative(nr
, &hwc
->period_left
))
4657 perf_swevent_overflow(event
, 0, data
, regs
);
4660 static int perf_exclude_event(struct perf_event
*event
,
4661 struct pt_regs
*regs
)
4663 if (event
->hw
.state
& PERF_HES_STOPPED
)
4667 if (event
->attr
.exclude_user
&& user_mode(regs
))
4670 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4677 static int perf_swevent_match(struct perf_event
*event
,
4678 enum perf_type_id type
,
4680 struct perf_sample_data
*data
,
4681 struct pt_regs
*regs
)
4683 if (event
->attr
.type
!= type
)
4686 if (event
->attr
.config
!= event_id
)
4689 if (perf_exclude_event(event
, regs
))
4695 static inline u64
swevent_hash(u64 type
, u32 event_id
)
4697 u64 val
= event_id
| (type
<< 32);
4699 return hash_64(val
, SWEVENT_HLIST_BITS
);
4702 static inline struct hlist_head
*
4703 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
4705 u64 hash
= swevent_hash(type
, event_id
);
4707 return &hlist
->heads
[hash
];
4710 /* For the read side: events when they trigger */
4711 static inline struct hlist_head
*
4712 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
4714 struct swevent_hlist
*hlist
;
4716 hlist
= rcu_dereference(swhash
->swevent_hlist
);
4720 return __find_swevent_head(hlist
, type
, event_id
);
4723 /* For the event head insertion and removal in the hlist */
4724 static inline struct hlist_head
*
4725 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
4727 struct swevent_hlist
*hlist
;
4728 u32 event_id
= event
->attr
.config
;
4729 u64 type
= event
->attr
.type
;
4732 * Event scheduling is always serialized against hlist allocation
4733 * and release. Which makes the protected version suitable here.
4734 * The context lock guarantees that.
4736 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
4737 lockdep_is_held(&event
->ctx
->lock
));
4741 return __find_swevent_head(hlist
, type
, event_id
);
4744 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4746 struct perf_sample_data
*data
,
4747 struct pt_regs
*regs
)
4749 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4750 struct perf_event
*event
;
4751 struct hlist_node
*node
;
4752 struct hlist_head
*head
;
4755 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
4759 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4760 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4761 perf_swevent_event(event
, nr
, data
, regs
);
4767 int perf_swevent_get_recursion_context(void)
4769 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4771 return get_recursion_context(swhash
->recursion
);
4773 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4775 inline void perf_swevent_put_recursion_context(int rctx
)
4777 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4779 put_recursion_context(swhash
->recursion
, rctx
);
4782 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
4784 struct perf_sample_data data
;
4787 preempt_disable_notrace();
4788 rctx
= perf_swevent_get_recursion_context();
4792 perf_sample_data_init(&data
, addr
);
4794 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
4796 perf_swevent_put_recursion_context(rctx
);
4797 preempt_enable_notrace();
4800 static void perf_swevent_read(struct perf_event
*event
)
4804 static int perf_swevent_add(struct perf_event
*event
, int flags
)
4806 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4807 struct hw_perf_event
*hwc
= &event
->hw
;
4808 struct hlist_head
*head
;
4810 if (is_sampling_event(event
)) {
4811 hwc
->last_period
= hwc
->sample_period
;
4812 perf_swevent_set_period(event
);
4815 hwc
->state
= !(flags
& PERF_EF_START
);
4817 head
= find_swevent_head(swhash
, event
);
4818 if (WARN_ON_ONCE(!head
))
4821 hlist_add_head_rcu(&event
->hlist_entry
, head
);
4826 static void perf_swevent_del(struct perf_event
*event
, int flags
)
4828 hlist_del_rcu(&event
->hlist_entry
);
4831 static void perf_swevent_start(struct perf_event
*event
, int flags
)
4833 event
->hw
.state
= 0;
4836 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
4838 event
->hw
.state
= PERF_HES_STOPPED
;
4841 /* Deref the hlist from the update side */
4842 static inline struct swevent_hlist
*
4843 swevent_hlist_deref(struct swevent_htable
*swhash
)
4845 return rcu_dereference_protected(swhash
->swevent_hlist
,
4846 lockdep_is_held(&swhash
->hlist_mutex
));
4849 static void swevent_hlist_release(struct swevent_htable
*swhash
)
4851 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
4856 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
4857 kfree_rcu(hlist
, rcu_head
);
4860 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
4862 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4864 mutex_lock(&swhash
->hlist_mutex
);
4866 if (!--swhash
->hlist_refcount
)
4867 swevent_hlist_release(swhash
);
4869 mutex_unlock(&swhash
->hlist_mutex
);
4872 static void swevent_hlist_put(struct perf_event
*event
)
4876 if (event
->cpu
!= -1) {
4877 swevent_hlist_put_cpu(event
, event
->cpu
);
4881 for_each_possible_cpu(cpu
)
4882 swevent_hlist_put_cpu(event
, cpu
);
4885 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
4887 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4890 mutex_lock(&swhash
->hlist_mutex
);
4892 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
4893 struct swevent_hlist
*hlist
;
4895 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
4900 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
4902 swhash
->hlist_refcount
++;
4904 mutex_unlock(&swhash
->hlist_mutex
);
4909 static int swevent_hlist_get(struct perf_event
*event
)
4912 int cpu
, failed_cpu
;
4914 if (event
->cpu
!= -1)
4915 return swevent_hlist_get_cpu(event
, event
->cpu
);
4918 for_each_possible_cpu(cpu
) {
4919 err
= swevent_hlist_get_cpu(event
, cpu
);
4929 for_each_possible_cpu(cpu
) {
4930 if (cpu
== failed_cpu
)
4932 swevent_hlist_put_cpu(event
, cpu
);
4939 struct jump_label_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4941 static void sw_perf_event_destroy(struct perf_event
*event
)
4943 u64 event_id
= event
->attr
.config
;
4945 WARN_ON(event
->parent
);
4947 jump_label_dec(&perf_swevent_enabled
[event_id
]);
4948 swevent_hlist_put(event
);
4951 static int perf_swevent_init(struct perf_event
*event
)
4953 int event_id
= event
->attr
.config
;
4955 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
4959 case PERF_COUNT_SW_CPU_CLOCK
:
4960 case PERF_COUNT_SW_TASK_CLOCK
:
4967 if (event_id
>= PERF_COUNT_SW_MAX
)
4970 if (!event
->parent
) {
4973 err
= swevent_hlist_get(event
);
4977 jump_label_inc(&perf_swevent_enabled
[event_id
]);
4978 event
->destroy
= sw_perf_event_destroy
;
4984 static struct pmu perf_swevent
= {
4985 .task_ctx_nr
= perf_sw_context
,
4987 .event_init
= perf_swevent_init
,
4988 .add
= perf_swevent_add
,
4989 .del
= perf_swevent_del
,
4990 .start
= perf_swevent_start
,
4991 .stop
= perf_swevent_stop
,
4992 .read
= perf_swevent_read
,
4995 #ifdef CONFIG_EVENT_TRACING
4997 static int perf_tp_filter_match(struct perf_event
*event
,
4998 struct perf_sample_data
*data
)
5000 void *record
= data
->raw
->data
;
5002 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5007 static int perf_tp_event_match(struct perf_event
*event
,
5008 struct perf_sample_data
*data
,
5009 struct pt_regs
*regs
)
5011 if (event
->hw
.state
& PERF_HES_STOPPED
)
5014 * All tracepoints are from kernel-space.
5016 if (event
->attr
.exclude_kernel
)
5019 if (!perf_tp_filter_match(event
, data
))
5025 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5026 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
5028 struct perf_sample_data data
;
5029 struct perf_event
*event
;
5030 struct hlist_node
*node
;
5032 struct perf_raw_record raw
= {
5037 perf_sample_data_init(&data
, addr
);
5040 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5041 if (perf_tp_event_match(event
, &data
, regs
))
5042 perf_swevent_event(event
, count
, &data
, regs
);
5045 perf_swevent_put_recursion_context(rctx
);
5047 EXPORT_SYMBOL_GPL(perf_tp_event
);
5049 static void tp_perf_event_destroy(struct perf_event
*event
)
5051 perf_trace_destroy(event
);
5054 static int perf_tp_event_init(struct perf_event
*event
)
5058 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5061 err
= perf_trace_init(event
);
5065 event
->destroy
= tp_perf_event_destroy
;
5070 static struct pmu perf_tracepoint
= {
5071 .task_ctx_nr
= perf_sw_context
,
5073 .event_init
= perf_tp_event_init
,
5074 .add
= perf_trace_add
,
5075 .del
= perf_trace_del
,
5076 .start
= perf_swevent_start
,
5077 .stop
= perf_swevent_stop
,
5078 .read
= perf_swevent_read
,
5081 static inline void perf_tp_register(void)
5083 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5086 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5091 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5094 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5095 if (IS_ERR(filter_str
))
5096 return PTR_ERR(filter_str
);
5098 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5104 static void perf_event_free_filter(struct perf_event
*event
)
5106 ftrace_profile_free_filter(event
);
5111 static inline void perf_tp_register(void)
5115 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5120 static void perf_event_free_filter(struct perf_event
*event
)
5124 #endif /* CONFIG_EVENT_TRACING */
5126 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5127 void perf_bp_event(struct perf_event
*bp
, void *data
)
5129 struct perf_sample_data sample
;
5130 struct pt_regs
*regs
= data
;
5132 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
5134 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5135 perf_swevent_event(bp
, 1, &sample
, regs
);
5140 * hrtimer based swevent callback
5143 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5145 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5146 struct perf_sample_data data
;
5147 struct pt_regs
*regs
;
5148 struct perf_event
*event
;
5151 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5153 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5154 return HRTIMER_NORESTART
;
5156 event
->pmu
->read(event
);
5158 perf_sample_data_init(&data
, 0);
5159 data
.period
= event
->hw
.last_period
;
5160 regs
= get_irq_regs();
5162 if (regs
&& !perf_exclude_event(event
, regs
)) {
5163 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
5164 if (perf_event_overflow(event
, &data
, regs
))
5165 ret
= HRTIMER_NORESTART
;
5168 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5169 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5174 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5176 struct hw_perf_event
*hwc
= &event
->hw
;
5179 if (!is_sampling_event(event
))
5182 period
= local64_read(&hwc
->period_left
);
5187 local64_set(&hwc
->period_left
, 0);
5189 period
= max_t(u64
, 10000, hwc
->sample_period
);
5191 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5192 ns_to_ktime(period
), 0,
5193 HRTIMER_MODE_REL_PINNED
, 0);
5196 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5198 struct hw_perf_event
*hwc
= &event
->hw
;
5200 if (is_sampling_event(event
)) {
5201 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5202 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5204 hrtimer_cancel(&hwc
->hrtimer
);
5208 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
5210 struct hw_perf_event
*hwc
= &event
->hw
;
5212 if (!is_sampling_event(event
))
5215 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5216 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5219 * Since hrtimers have a fixed rate, we can do a static freq->period
5220 * mapping and avoid the whole period adjust feedback stuff.
5222 if (event
->attr
.freq
) {
5223 long freq
= event
->attr
.sample_freq
;
5225 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
5226 hwc
->sample_period
= event
->attr
.sample_period
;
5227 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5228 event
->attr
.freq
= 0;
5233 * Software event: cpu wall time clock
5236 static void cpu_clock_event_update(struct perf_event
*event
)
5241 now
= local_clock();
5242 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5243 local64_add(now
- prev
, &event
->count
);
5246 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5248 local64_set(&event
->hw
.prev_count
, local_clock());
5249 perf_swevent_start_hrtimer(event
);
5252 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5254 perf_swevent_cancel_hrtimer(event
);
5255 cpu_clock_event_update(event
);
5258 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5260 if (flags
& PERF_EF_START
)
5261 cpu_clock_event_start(event
, flags
);
5266 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5268 cpu_clock_event_stop(event
, flags
);
5271 static void cpu_clock_event_read(struct perf_event
*event
)
5273 cpu_clock_event_update(event
);
5276 static int cpu_clock_event_init(struct perf_event
*event
)
5278 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5281 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5284 perf_swevent_init_hrtimer(event
);
5289 static struct pmu perf_cpu_clock
= {
5290 .task_ctx_nr
= perf_sw_context
,
5292 .event_init
= cpu_clock_event_init
,
5293 .add
= cpu_clock_event_add
,
5294 .del
= cpu_clock_event_del
,
5295 .start
= cpu_clock_event_start
,
5296 .stop
= cpu_clock_event_stop
,
5297 .read
= cpu_clock_event_read
,
5301 * Software event: task time clock
5304 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5309 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5311 local64_add(delta
, &event
->count
);
5314 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5316 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5317 perf_swevent_start_hrtimer(event
);
5320 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5322 perf_swevent_cancel_hrtimer(event
);
5323 task_clock_event_update(event
, event
->ctx
->time
);
5326 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5328 if (flags
& PERF_EF_START
)
5329 task_clock_event_start(event
, flags
);
5334 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5336 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5339 static void task_clock_event_read(struct perf_event
*event
)
5341 u64 now
= perf_clock();
5342 u64 delta
= now
- event
->ctx
->timestamp
;
5343 u64 time
= event
->ctx
->time
+ delta
;
5345 task_clock_event_update(event
, time
);
5348 static int task_clock_event_init(struct perf_event
*event
)
5350 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5353 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5356 perf_swevent_init_hrtimer(event
);
5361 static struct pmu perf_task_clock
= {
5362 .task_ctx_nr
= perf_sw_context
,
5364 .event_init
= task_clock_event_init
,
5365 .add
= task_clock_event_add
,
5366 .del
= task_clock_event_del
,
5367 .start
= task_clock_event_start
,
5368 .stop
= task_clock_event_stop
,
5369 .read
= task_clock_event_read
,
5372 static void perf_pmu_nop_void(struct pmu
*pmu
)
5376 static int perf_pmu_nop_int(struct pmu
*pmu
)
5381 static void perf_pmu_start_txn(struct pmu
*pmu
)
5383 perf_pmu_disable(pmu
);
5386 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5388 perf_pmu_enable(pmu
);
5392 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5394 perf_pmu_enable(pmu
);
5398 * Ensures all contexts with the same task_ctx_nr have the same
5399 * pmu_cpu_context too.
5401 static void *find_pmu_context(int ctxn
)
5408 list_for_each_entry(pmu
, &pmus
, entry
) {
5409 if (pmu
->task_ctx_nr
== ctxn
)
5410 return pmu
->pmu_cpu_context
;
5416 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5420 for_each_possible_cpu(cpu
) {
5421 struct perf_cpu_context
*cpuctx
;
5423 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5425 if (cpuctx
->active_pmu
== old_pmu
)
5426 cpuctx
->active_pmu
= pmu
;
5430 static void free_pmu_context(struct pmu
*pmu
)
5434 mutex_lock(&pmus_lock
);
5436 * Like a real lame refcount.
5438 list_for_each_entry(i
, &pmus
, entry
) {
5439 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5440 update_pmu_context(i
, pmu
);
5445 free_percpu(pmu
->pmu_cpu_context
);
5447 mutex_unlock(&pmus_lock
);
5449 static struct idr pmu_idr
;
5452 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5454 struct pmu
*pmu
= dev_get_drvdata(dev
);
5456 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5459 static struct device_attribute pmu_dev_attrs
[] = {
5464 static int pmu_bus_running
;
5465 static struct bus_type pmu_bus
= {
5466 .name
= "event_source",
5467 .dev_attrs
= pmu_dev_attrs
,
5470 static void pmu_dev_release(struct device
*dev
)
5475 static int pmu_dev_alloc(struct pmu
*pmu
)
5479 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5483 device_initialize(pmu
->dev
);
5484 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5488 dev_set_drvdata(pmu
->dev
, pmu
);
5489 pmu
->dev
->bus
= &pmu_bus
;
5490 pmu
->dev
->release
= pmu_dev_release
;
5491 ret
= device_add(pmu
->dev
);
5499 put_device(pmu
->dev
);
5503 static struct lock_class_key cpuctx_mutex
;
5504 static struct lock_class_key cpuctx_lock
;
5506 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5510 mutex_lock(&pmus_lock
);
5512 pmu
->pmu_disable_count
= alloc_percpu(int);
5513 if (!pmu
->pmu_disable_count
)
5522 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
5526 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
5534 if (pmu_bus_running
) {
5535 ret
= pmu_dev_alloc(pmu
);
5541 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
5542 if (pmu
->pmu_cpu_context
)
5543 goto got_cpu_context
;
5545 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
5546 if (!pmu
->pmu_cpu_context
)
5549 for_each_possible_cpu(cpu
) {
5550 struct perf_cpu_context
*cpuctx
;
5552 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5553 __perf_event_init_context(&cpuctx
->ctx
);
5554 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
5555 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
5556 cpuctx
->ctx
.type
= cpu_context
;
5557 cpuctx
->ctx
.pmu
= pmu
;
5558 cpuctx
->jiffies_interval
= 1;
5559 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
5560 cpuctx
->active_pmu
= pmu
;
5564 if (!pmu
->start_txn
) {
5565 if (pmu
->pmu_enable
) {
5567 * If we have pmu_enable/pmu_disable calls, install
5568 * transaction stubs that use that to try and batch
5569 * hardware accesses.
5571 pmu
->start_txn
= perf_pmu_start_txn
;
5572 pmu
->commit_txn
= perf_pmu_commit_txn
;
5573 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
5575 pmu
->start_txn
= perf_pmu_nop_void
;
5576 pmu
->commit_txn
= perf_pmu_nop_int
;
5577 pmu
->cancel_txn
= perf_pmu_nop_void
;
5581 if (!pmu
->pmu_enable
) {
5582 pmu
->pmu_enable
= perf_pmu_nop_void
;
5583 pmu
->pmu_disable
= perf_pmu_nop_void
;
5586 list_add_rcu(&pmu
->entry
, &pmus
);
5589 mutex_unlock(&pmus_lock
);
5594 device_del(pmu
->dev
);
5595 put_device(pmu
->dev
);
5598 if (pmu
->type
>= PERF_TYPE_MAX
)
5599 idr_remove(&pmu_idr
, pmu
->type
);
5602 free_percpu(pmu
->pmu_disable_count
);
5606 void perf_pmu_unregister(struct pmu
*pmu
)
5608 mutex_lock(&pmus_lock
);
5609 list_del_rcu(&pmu
->entry
);
5610 mutex_unlock(&pmus_lock
);
5613 * We dereference the pmu list under both SRCU and regular RCU, so
5614 * synchronize against both of those.
5616 synchronize_srcu(&pmus_srcu
);
5619 free_percpu(pmu
->pmu_disable_count
);
5620 if (pmu
->type
>= PERF_TYPE_MAX
)
5621 idr_remove(&pmu_idr
, pmu
->type
);
5622 device_del(pmu
->dev
);
5623 put_device(pmu
->dev
);
5624 free_pmu_context(pmu
);
5627 struct pmu
*perf_init_event(struct perf_event
*event
)
5629 struct pmu
*pmu
= NULL
;
5633 idx
= srcu_read_lock(&pmus_srcu
);
5636 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
5640 ret
= pmu
->event_init(event
);
5646 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5648 ret
= pmu
->event_init(event
);
5652 if (ret
!= -ENOENT
) {
5657 pmu
= ERR_PTR(-ENOENT
);
5659 srcu_read_unlock(&pmus_srcu
, idx
);
5665 * Allocate and initialize a event structure
5667 static struct perf_event
*
5668 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
5669 struct task_struct
*task
,
5670 struct perf_event
*group_leader
,
5671 struct perf_event
*parent_event
,
5672 perf_overflow_handler_t overflow_handler
,
5676 struct perf_event
*event
;
5677 struct hw_perf_event
*hwc
;
5680 if ((unsigned)cpu
>= nr_cpu_ids
) {
5681 if (!task
|| cpu
!= -1)
5682 return ERR_PTR(-EINVAL
);
5685 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
5687 return ERR_PTR(-ENOMEM
);
5690 * Single events are their own group leaders, with an
5691 * empty sibling list:
5694 group_leader
= event
;
5696 mutex_init(&event
->child_mutex
);
5697 INIT_LIST_HEAD(&event
->child_list
);
5699 INIT_LIST_HEAD(&event
->group_entry
);
5700 INIT_LIST_HEAD(&event
->event_entry
);
5701 INIT_LIST_HEAD(&event
->sibling_list
);
5702 INIT_LIST_HEAD(&event
->rb_entry
);
5704 init_waitqueue_head(&event
->waitq
);
5705 init_irq_work(&event
->pending
, perf_pending_event
);
5707 mutex_init(&event
->mmap_mutex
);
5710 event
->attr
= *attr
;
5711 event
->group_leader
= group_leader
;
5715 event
->parent
= parent_event
;
5717 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
5718 event
->id
= atomic64_inc_return(&perf_event_id
);
5720 event
->state
= PERF_EVENT_STATE_INACTIVE
;
5723 event
->attach_state
= PERF_ATTACH_TASK
;
5724 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5726 * hw_breakpoint is a bit difficult here..
5728 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
5729 event
->hw
.bp_target
= task
;
5733 if (!overflow_handler
&& parent_event
) {
5734 overflow_handler
= parent_event
->overflow_handler
;
5735 context
= parent_event
->overflow_handler_context
;
5738 event
->overflow_handler
= overflow_handler
;
5739 event
->overflow_handler_context
= context
;
5742 event
->state
= PERF_EVENT_STATE_OFF
;
5747 hwc
->sample_period
= attr
->sample_period
;
5748 if (attr
->freq
&& attr
->sample_freq
)
5749 hwc
->sample_period
= 1;
5750 hwc
->last_period
= hwc
->sample_period
;
5752 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5755 * we currently do not support PERF_FORMAT_GROUP on inherited events
5757 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
5760 pmu
= perf_init_event(event
);
5766 else if (IS_ERR(pmu
))
5771 put_pid_ns(event
->ns
);
5773 return ERR_PTR(err
);
5776 if (!event
->parent
) {
5777 if (event
->attach_state
& PERF_ATTACH_TASK
)
5778 jump_label_inc(&perf_sched_events
);
5779 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
5780 atomic_inc(&nr_mmap_events
);
5781 if (event
->attr
.comm
)
5782 atomic_inc(&nr_comm_events
);
5783 if (event
->attr
.task
)
5784 atomic_inc(&nr_task_events
);
5785 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5786 err
= get_callchain_buffers();
5789 return ERR_PTR(err
);
5797 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5798 struct perf_event_attr
*attr
)
5803 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
5807 * zero the full structure, so that a short copy will be nice.
5809 memset(attr
, 0, sizeof(*attr
));
5811 ret
= get_user(size
, &uattr
->size
);
5815 if (size
> PAGE_SIZE
) /* silly large */
5818 if (!size
) /* abi compat */
5819 size
= PERF_ATTR_SIZE_VER0
;
5821 if (size
< PERF_ATTR_SIZE_VER0
)
5825 * If we're handed a bigger struct than we know of,
5826 * ensure all the unknown bits are 0 - i.e. new
5827 * user-space does not rely on any kernel feature
5828 * extensions we dont know about yet.
5830 if (size
> sizeof(*attr
)) {
5831 unsigned char __user
*addr
;
5832 unsigned char __user
*end
;
5835 addr
= (void __user
*)uattr
+ sizeof(*attr
);
5836 end
= (void __user
*)uattr
+ size
;
5838 for (; addr
< end
; addr
++) {
5839 ret
= get_user(val
, addr
);
5845 size
= sizeof(*attr
);
5848 ret
= copy_from_user(attr
, uattr
, size
);
5852 if (attr
->__reserved_1
)
5855 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
5858 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
5865 put_user(sizeof(*attr
), &uattr
->size
);
5871 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
5873 struct ring_buffer
*rb
= NULL
, *old_rb
= NULL
;
5879 /* don't allow circular references */
5880 if (event
== output_event
)
5884 * Don't allow cross-cpu buffers
5886 if (output_event
->cpu
!= event
->cpu
)
5890 * If its not a per-cpu rb, it must be the same task.
5892 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
5896 mutex_lock(&event
->mmap_mutex
);
5897 /* Can't redirect output if we've got an active mmap() */
5898 if (atomic_read(&event
->mmap_count
))
5902 /* get the rb we want to redirect to */
5903 rb
= ring_buffer_get(output_event
);
5909 rcu_assign_pointer(event
->rb
, rb
);
5911 ring_buffer_detach(event
, old_rb
);
5914 mutex_unlock(&event
->mmap_mutex
);
5917 ring_buffer_put(old_rb
);
5923 * sys_perf_event_open - open a performance event, associate it to a task/cpu
5925 * @attr_uptr: event_id type attributes for monitoring/sampling
5928 * @group_fd: group leader event fd
5930 SYSCALL_DEFINE5(perf_event_open
,
5931 struct perf_event_attr __user
*, attr_uptr
,
5932 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
5934 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
5935 struct perf_event
*event
, *sibling
;
5936 struct perf_event_attr attr
;
5937 struct perf_event_context
*ctx
;
5938 struct file
*event_file
= NULL
;
5939 struct file
*group_file
= NULL
;
5940 struct task_struct
*task
= NULL
;
5944 int fput_needed
= 0;
5947 /* for future expandability... */
5948 if (flags
& ~PERF_FLAG_ALL
)
5951 err
= perf_copy_attr(attr_uptr
, &attr
);
5955 if (!attr
.exclude_kernel
) {
5956 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
5961 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
5966 * In cgroup mode, the pid argument is used to pass the fd
5967 * opened to the cgroup directory in cgroupfs. The cpu argument
5968 * designates the cpu on which to monitor threads from that
5971 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
5974 event_fd
= get_unused_fd_flags(O_RDWR
);
5978 if (group_fd
!= -1) {
5979 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
5980 if (IS_ERR(group_leader
)) {
5981 err
= PTR_ERR(group_leader
);
5984 group_file
= group_leader
->filp
;
5985 if (flags
& PERF_FLAG_FD_OUTPUT
)
5986 output_event
= group_leader
;
5987 if (flags
& PERF_FLAG_FD_NO_GROUP
)
5988 group_leader
= NULL
;
5991 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
5992 task
= find_lively_task_by_vpid(pid
);
5994 err
= PTR_ERR(task
);
5999 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
6001 if (IS_ERR(event
)) {
6002 err
= PTR_ERR(event
);
6006 if (flags
& PERF_FLAG_PID_CGROUP
) {
6007 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6012 * - that has cgroup constraint on event->cpu
6013 * - that may need work on context switch
6015 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
6016 jump_label_inc(&perf_sched_events
);
6020 * Special case software events and allow them to be part of
6021 * any hardware group.
6026 (is_software_event(event
) != is_software_event(group_leader
))) {
6027 if (is_software_event(event
)) {
6029 * If event and group_leader are not both a software
6030 * event, and event is, then group leader is not.
6032 * Allow the addition of software events to !software
6033 * groups, this is safe because software events never
6036 pmu
= group_leader
->pmu
;
6037 } else if (is_software_event(group_leader
) &&
6038 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6040 * In case the group is a pure software group, and we
6041 * try to add a hardware event, move the whole group to
6042 * the hardware context.
6049 * Get the target context (task or percpu):
6051 ctx
= find_get_context(pmu
, task
, cpu
);
6058 put_task_struct(task
);
6063 * Look up the group leader (we will attach this event to it):
6069 * Do not allow a recursive hierarchy (this new sibling
6070 * becoming part of another group-sibling):
6072 if (group_leader
->group_leader
!= group_leader
)
6075 * Do not allow to attach to a group in a different
6076 * task or CPU context:
6079 if (group_leader
->ctx
->type
!= ctx
->type
)
6082 if (group_leader
->ctx
!= ctx
)
6087 * Only a group leader can be exclusive or pinned
6089 if (attr
.exclusive
|| attr
.pinned
)
6094 err
= perf_event_set_output(event
, output_event
);
6099 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6100 if (IS_ERR(event_file
)) {
6101 err
= PTR_ERR(event_file
);
6106 struct perf_event_context
*gctx
= group_leader
->ctx
;
6108 mutex_lock(&gctx
->mutex
);
6109 perf_remove_from_context(group_leader
);
6110 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6112 perf_remove_from_context(sibling
);
6115 mutex_unlock(&gctx
->mutex
);
6119 event
->filp
= event_file
;
6120 WARN_ON_ONCE(ctx
->parent_ctx
);
6121 mutex_lock(&ctx
->mutex
);
6124 perf_install_in_context(ctx
, group_leader
, cpu
);
6126 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6128 perf_install_in_context(ctx
, sibling
, cpu
);
6133 perf_install_in_context(ctx
, event
, cpu
);
6135 perf_unpin_context(ctx
);
6136 mutex_unlock(&ctx
->mutex
);
6138 event
->owner
= current
;
6140 mutex_lock(¤t
->perf_event_mutex
);
6141 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6142 mutex_unlock(¤t
->perf_event_mutex
);
6145 * Precalculate sample_data sizes
6147 perf_event__header_size(event
);
6148 perf_event__id_header_size(event
);
6151 * Drop the reference on the group_event after placing the
6152 * new event on the sibling_list. This ensures destruction
6153 * of the group leader will find the pointer to itself in
6154 * perf_group_detach().
6156 fput_light(group_file
, fput_needed
);
6157 fd_install(event_fd
, event_file
);
6161 perf_unpin_context(ctx
);
6167 put_task_struct(task
);
6169 fput_light(group_file
, fput_needed
);
6171 put_unused_fd(event_fd
);
6176 * perf_event_create_kernel_counter
6178 * @attr: attributes of the counter to create
6179 * @cpu: cpu in which the counter is bound
6180 * @task: task to profile (NULL for percpu)
6183 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6184 struct task_struct
*task
,
6185 perf_overflow_handler_t overflow_handler
,
6188 struct perf_event_context
*ctx
;
6189 struct perf_event
*event
;
6193 * Get the target context (task or percpu):
6196 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
6197 overflow_handler
, context
);
6198 if (IS_ERR(event
)) {
6199 err
= PTR_ERR(event
);
6203 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6210 WARN_ON_ONCE(ctx
->parent_ctx
);
6211 mutex_lock(&ctx
->mutex
);
6212 perf_install_in_context(ctx
, event
, cpu
);
6214 perf_unpin_context(ctx
);
6215 mutex_unlock(&ctx
->mutex
);
6222 return ERR_PTR(err
);
6224 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6226 static void sync_child_event(struct perf_event
*child_event
,
6227 struct task_struct
*child
)
6229 struct perf_event
*parent_event
= child_event
->parent
;
6232 if (child_event
->attr
.inherit_stat
)
6233 perf_event_read_event(child_event
, child
);
6235 child_val
= perf_event_count(child_event
);
6238 * Add back the child's count to the parent's count:
6240 atomic64_add(child_val
, &parent_event
->child_count
);
6241 atomic64_add(child_event
->total_time_enabled
,
6242 &parent_event
->child_total_time_enabled
);
6243 atomic64_add(child_event
->total_time_running
,
6244 &parent_event
->child_total_time_running
);
6247 * Remove this event from the parent's list
6249 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6250 mutex_lock(&parent_event
->child_mutex
);
6251 list_del_init(&child_event
->child_list
);
6252 mutex_unlock(&parent_event
->child_mutex
);
6255 * Release the parent event, if this was the last
6258 fput(parent_event
->filp
);
6262 __perf_event_exit_task(struct perf_event
*child_event
,
6263 struct perf_event_context
*child_ctx
,
6264 struct task_struct
*child
)
6266 if (child_event
->parent
) {
6267 raw_spin_lock_irq(&child_ctx
->lock
);
6268 perf_group_detach(child_event
);
6269 raw_spin_unlock_irq(&child_ctx
->lock
);
6272 perf_remove_from_context(child_event
);
6275 * It can happen that the parent exits first, and has events
6276 * that are still around due to the child reference. These
6277 * events need to be zapped.
6279 if (child_event
->parent
) {
6280 sync_child_event(child_event
, child
);
6281 free_event(child_event
);
6285 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6287 struct perf_event
*child_event
, *tmp
;
6288 struct perf_event_context
*child_ctx
;
6289 unsigned long flags
;
6291 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6292 perf_event_task(child
, NULL
, 0);
6296 local_irq_save(flags
);
6298 * We can't reschedule here because interrupts are disabled,
6299 * and either child is current or it is a task that can't be
6300 * scheduled, so we are now safe from rescheduling changing
6303 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6306 * Take the context lock here so that if find_get_context is
6307 * reading child->perf_event_ctxp, we wait until it has
6308 * incremented the context's refcount before we do put_ctx below.
6310 raw_spin_lock(&child_ctx
->lock
);
6311 task_ctx_sched_out(child_ctx
);
6312 child
->perf_event_ctxp
[ctxn
] = NULL
;
6314 * If this context is a clone; unclone it so it can't get
6315 * swapped to another process while we're removing all
6316 * the events from it.
6318 unclone_ctx(child_ctx
);
6319 update_context_time(child_ctx
);
6320 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6323 * Report the task dead after unscheduling the events so that we
6324 * won't get any samples after PERF_RECORD_EXIT. We can however still
6325 * get a few PERF_RECORD_READ events.
6327 perf_event_task(child
, child_ctx
, 0);
6330 * We can recurse on the same lock type through:
6332 * __perf_event_exit_task()
6333 * sync_child_event()
6334 * fput(parent_event->filp)
6336 * mutex_lock(&ctx->mutex)
6338 * But since its the parent context it won't be the same instance.
6340 mutex_lock(&child_ctx
->mutex
);
6343 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6345 __perf_event_exit_task(child_event
, child_ctx
, child
);
6347 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6349 __perf_event_exit_task(child_event
, child_ctx
, child
);
6352 * If the last event was a group event, it will have appended all
6353 * its siblings to the list, but we obtained 'tmp' before that which
6354 * will still point to the list head terminating the iteration.
6356 if (!list_empty(&child_ctx
->pinned_groups
) ||
6357 !list_empty(&child_ctx
->flexible_groups
))
6360 mutex_unlock(&child_ctx
->mutex
);
6366 * When a child task exits, feed back event values to parent events.
6368 void perf_event_exit_task(struct task_struct
*child
)
6370 struct perf_event
*event
, *tmp
;
6373 mutex_lock(&child
->perf_event_mutex
);
6374 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6376 list_del_init(&event
->owner_entry
);
6379 * Ensure the list deletion is visible before we clear
6380 * the owner, closes a race against perf_release() where
6381 * we need to serialize on the owner->perf_event_mutex.
6384 event
->owner
= NULL
;
6386 mutex_unlock(&child
->perf_event_mutex
);
6388 for_each_task_context_nr(ctxn
)
6389 perf_event_exit_task_context(child
, ctxn
);
6392 static void perf_free_event(struct perf_event
*event
,
6393 struct perf_event_context
*ctx
)
6395 struct perf_event
*parent
= event
->parent
;
6397 if (WARN_ON_ONCE(!parent
))
6400 mutex_lock(&parent
->child_mutex
);
6401 list_del_init(&event
->child_list
);
6402 mutex_unlock(&parent
->child_mutex
);
6406 perf_group_detach(event
);
6407 list_del_event(event
, ctx
);
6412 * free an unexposed, unused context as created by inheritance by
6413 * perf_event_init_task below, used by fork() in case of fail.
6415 void perf_event_free_task(struct task_struct
*task
)
6417 struct perf_event_context
*ctx
;
6418 struct perf_event
*event
, *tmp
;
6421 for_each_task_context_nr(ctxn
) {
6422 ctx
= task
->perf_event_ctxp
[ctxn
];
6426 mutex_lock(&ctx
->mutex
);
6428 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6430 perf_free_event(event
, ctx
);
6432 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6434 perf_free_event(event
, ctx
);
6436 if (!list_empty(&ctx
->pinned_groups
) ||
6437 !list_empty(&ctx
->flexible_groups
))
6440 mutex_unlock(&ctx
->mutex
);
6446 void perf_event_delayed_put(struct task_struct
*task
)
6450 for_each_task_context_nr(ctxn
)
6451 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6455 * inherit a event from parent task to child task:
6457 static struct perf_event
*
6458 inherit_event(struct perf_event
*parent_event
,
6459 struct task_struct
*parent
,
6460 struct perf_event_context
*parent_ctx
,
6461 struct task_struct
*child
,
6462 struct perf_event
*group_leader
,
6463 struct perf_event_context
*child_ctx
)
6465 struct perf_event
*child_event
;
6466 unsigned long flags
;
6469 * Instead of creating recursive hierarchies of events,
6470 * we link inherited events back to the original parent,
6471 * which has a filp for sure, which we use as the reference
6474 if (parent_event
->parent
)
6475 parent_event
= parent_event
->parent
;
6477 child_event
= perf_event_alloc(&parent_event
->attr
,
6480 group_leader
, parent_event
,
6482 if (IS_ERR(child_event
))
6487 * Make the child state follow the state of the parent event,
6488 * not its attr.disabled bit. We hold the parent's mutex,
6489 * so we won't race with perf_event_{en, dis}able_family.
6491 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6492 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6494 child_event
->state
= PERF_EVENT_STATE_OFF
;
6496 if (parent_event
->attr
.freq
) {
6497 u64 sample_period
= parent_event
->hw
.sample_period
;
6498 struct hw_perf_event
*hwc
= &child_event
->hw
;
6500 hwc
->sample_period
= sample_period
;
6501 hwc
->last_period
= sample_period
;
6503 local64_set(&hwc
->period_left
, sample_period
);
6506 child_event
->ctx
= child_ctx
;
6507 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6508 child_event
->overflow_handler_context
6509 = parent_event
->overflow_handler_context
;
6512 * Precalculate sample_data sizes
6514 perf_event__header_size(child_event
);
6515 perf_event__id_header_size(child_event
);
6518 * Link it up in the child's context:
6520 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6521 add_event_to_ctx(child_event
, child_ctx
);
6522 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6525 * Get a reference to the parent filp - we will fput it
6526 * when the child event exits. This is safe to do because
6527 * we are in the parent and we know that the filp still
6528 * exists and has a nonzero count:
6530 atomic_long_inc(&parent_event
->filp
->f_count
);
6533 * Link this into the parent event's child list
6535 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6536 mutex_lock(&parent_event
->child_mutex
);
6537 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
6538 mutex_unlock(&parent_event
->child_mutex
);
6543 static int inherit_group(struct perf_event
*parent_event
,
6544 struct task_struct
*parent
,
6545 struct perf_event_context
*parent_ctx
,
6546 struct task_struct
*child
,
6547 struct perf_event_context
*child_ctx
)
6549 struct perf_event
*leader
;
6550 struct perf_event
*sub
;
6551 struct perf_event
*child_ctr
;
6553 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
6554 child
, NULL
, child_ctx
);
6556 return PTR_ERR(leader
);
6557 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
6558 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
6559 child
, leader
, child_ctx
);
6560 if (IS_ERR(child_ctr
))
6561 return PTR_ERR(child_ctr
);
6567 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
6568 struct perf_event_context
*parent_ctx
,
6569 struct task_struct
*child
, int ctxn
,
6573 struct perf_event_context
*child_ctx
;
6575 if (!event
->attr
.inherit
) {
6580 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6583 * This is executed from the parent task context, so
6584 * inherit events that have been marked for cloning.
6585 * First allocate and initialize a context for the
6589 child_ctx
= alloc_perf_context(event
->pmu
, child
);
6593 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
6596 ret
= inherit_group(event
, parent
, parent_ctx
,
6606 * Initialize the perf_event context in task_struct
6608 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
6610 struct perf_event_context
*child_ctx
, *parent_ctx
;
6611 struct perf_event_context
*cloned_ctx
;
6612 struct perf_event
*event
;
6613 struct task_struct
*parent
= current
;
6614 int inherited_all
= 1;
6615 unsigned long flags
;
6618 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
6622 * If the parent's context is a clone, pin it so it won't get
6625 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
6628 * No need to check if parent_ctx != NULL here; since we saw
6629 * it non-NULL earlier, the only reason for it to become NULL
6630 * is if we exit, and since we're currently in the middle of
6631 * a fork we can't be exiting at the same time.
6635 * Lock the parent list. No need to lock the child - not PID
6636 * hashed yet and not running, so nobody can access it.
6638 mutex_lock(&parent_ctx
->mutex
);
6641 * We dont have to disable NMIs - we are only looking at
6642 * the list, not manipulating it:
6644 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
6645 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6646 child
, ctxn
, &inherited_all
);
6652 * We can't hold ctx->lock when iterating the ->flexible_group list due
6653 * to allocations, but we need to prevent rotation because
6654 * rotate_ctx() will change the list from interrupt context.
6656 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6657 parent_ctx
->rotate_disable
= 1;
6658 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6660 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
6661 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6662 child
, ctxn
, &inherited_all
);
6667 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6668 parent_ctx
->rotate_disable
= 0;
6670 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6672 if (child_ctx
&& inherited_all
) {
6674 * Mark the child context as a clone of the parent
6675 * context, or of whatever the parent is a clone of.
6677 * Note that if the parent is a clone, the holding of
6678 * parent_ctx->lock avoids it from being uncloned.
6680 cloned_ctx
= parent_ctx
->parent_ctx
;
6682 child_ctx
->parent_ctx
= cloned_ctx
;
6683 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
6685 child_ctx
->parent_ctx
= parent_ctx
;
6686 child_ctx
->parent_gen
= parent_ctx
->generation
;
6688 get_ctx(child_ctx
->parent_ctx
);
6691 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6692 mutex_unlock(&parent_ctx
->mutex
);
6694 perf_unpin_context(parent_ctx
);
6695 put_ctx(parent_ctx
);
6701 * Initialize the perf_event context in task_struct
6703 int perf_event_init_task(struct task_struct
*child
)
6707 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
6708 mutex_init(&child
->perf_event_mutex
);
6709 INIT_LIST_HEAD(&child
->perf_event_list
);
6711 for_each_task_context_nr(ctxn
) {
6712 ret
= perf_event_init_context(child
, ctxn
);
6720 static void __init
perf_event_init_all_cpus(void)
6722 struct swevent_htable
*swhash
;
6725 for_each_possible_cpu(cpu
) {
6726 swhash
= &per_cpu(swevent_htable
, cpu
);
6727 mutex_init(&swhash
->hlist_mutex
);
6728 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
6732 static void __cpuinit
perf_event_init_cpu(int cpu
)
6734 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6736 mutex_lock(&swhash
->hlist_mutex
);
6737 if (swhash
->hlist_refcount
> 0) {
6738 struct swevent_hlist
*hlist
;
6740 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
6742 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6744 mutex_unlock(&swhash
->hlist_mutex
);
6747 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
6748 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
6750 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6752 WARN_ON(!irqs_disabled());
6754 list_del_init(&cpuctx
->rotation_list
);
6757 static void __perf_event_exit_context(void *__info
)
6759 struct perf_event_context
*ctx
= __info
;
6760 struct perf_event
*event
, *tmp
;
6762 perf_pmu_rotate_stop(ctx
->pmu
);
6764 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
6765 __perf_remove_from_context(event
);
6766 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
6767 __perf_remove_from_context(event
);
6770 static void perf_event_exit_cpu_context(int cpu
)
6772 struct perf_event_context
*ctx
;
6776 idx
= srcu_read_lock(&pmus_srcu
);
6777 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6778 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
6780 mutex_lock(&ctx
->mutex
);
6781 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
6782 mutex_unlock(&ctx
->mutex
);
6784 srcu_read_unlock(&pmus_srcu
, idx
);
6787 static void perf_event_exit_cpu(int cpu
)
6789 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6791 mutex_lock(&swhash
->hlist_mutex
);
6792 swevent_hlist_release(swhash
);
6793 mutex_unlock(&swhash
->hlist_mutex
);
6795 perf_event_exit_cpu_context(cpu
);
6798 static inline void perf_event_exit_cpu(int cpu
) { }
6802 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
6806 for_each_online_cpu(cpu
)
6807 perf_event_exit_cpu(cpu
);
6813 * Run the perf reboot notifier at the very last possible moment so that
6814 * the generic watchdog code runs as long as possible.
6816 static struct notifier_block perf_reboot_notifier
= {
6817 .notifier_call
= perf_reboot
,
6818 .priority
= INT_MIN
,
6821 static int __cpuinit
6822 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
6824 unsigned int cpu
= (long)hcpu
;
6826 switch (action
& ~CPU_TASKS_FROZEN
) {
6828 case CPU_UP_PREPARE
:
6829 case CPU_DOWN_FAILED
:
6830 perf_event_init_cpu(cpu
);
6833 case CPU_UP_CANCELED
:
6834 case CPU_DOWN_PREPARE
:
6835 perf_event_exit_cpu(cpu
);
6845 void __init
perf_event_init(void)
6851 perf_event_init_all_cpus();
6852 init_srcu_struct(&pmus_srcu
);
6853 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
6854 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
6855 perf_pmu_register(&perf_task_clock
, NULL
, -1);
6857 perf_cpu_notifier(perf_cpu_notify
);
6858 register_reboot_notifier(&perf_reboot_notifier
);
6860 ret
= init_hw_breakpoint();
6861 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
6864 static int __init
perf_event_sysfs_init(void)
6869 mutex_lock(&pmus_lock
);
6871 ret
= bus_register(&pmu_bus
);
6875 list_for_each_entry(pmu
, &pmus
, entry
) {
6876 if (!pmu
->name
|| pmu
->type
< 0)
6879 ret
= pmu_dev_alloc(pmu
);
6880 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
6882 pmu_bus_running
= 1;
6886 mutex_unlock(&pmus_lock
);
6890 device_initcall(perf_event_sysfs_init
);
6892 #ifdef CONFIG_CGROUP_PERF
6893 static struct cgroup_subsys_state
*perf_cgroup_create(
6894 struct cgroup_subsys
*ss
, struct cgroup
*cont
)
6896 struct perf_cgroup
*jc
;
6898 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
6900 return ERR_PTR(-ENOMEM
);
6902 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
6905 return ERR_PTR(-ENOMEM
);
6911 static void perf_cgroup_destroy(struct cgroup_subsys
*ss
,
6912 struct cgroup
*cont
)
6914 struct perf_cgroup
*jc
;
6915 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
6916 struct perf_cgroup
, css
);
6917 free_percpu(jc
->info
);
6921 static int __perf_cgroup_move(void *info
)
6923 struct task_struct
*task
= info
;
6924 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
6929 perf_cgroup_attach_task(struct cgroup
*cgrp
, struct task_struct
*task
)
6931 task_function_call(task
, __perf_cgroup_move
, task
);
6934 static void perf_cgroup_exit(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
6935 struct cgroup
*old_cgrp
, struct task_struct
*task
)
6938 * cgroup_exit() is called in the copy_process() failure path.
6939 * Ignore this case since the task hasn't ran yet, this avoids
6940 * trying to poke a half freed task state from generic code.
6942 if (!(task
->flags
& PF_EXITING
))
6945 perf_cgroup_attach_task(cgrp
, task
);
6948 struct cgroup_subsys perf_subsys
= {
6949 .name
= "perf_event",
6950 .subsys_id
= perf_subsys_id
,
6951 .create
= perf_cgroup_create
,
6952 .destroy
= perf_cgroup_destroy
,
6953 .exit
= perf_cgroup_exit
,
6954 .attach_task
= perf_cgroup_attach_task
,
6956 #endif /* CONFIG_CGROUP_PERF */