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_deferred 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
.freq
&& event
->attr
.sample_freq
)
1135 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1136 cpuctx
->exclusive
= 0;
1140 group_sched_out(struct perf_event
*group_event
,
1141 struct perf_cpu_context
*cpuctx
,
1142 struct perf_event_context
*ctx
)
1144 struct perf_event
*event
;
1145 int state
= group_event
->state
;
1147 event_sched_out(group_event
, cpuctx
, ctx
);
1150 * Schedule out siblings (if any):
1152 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1153 event_sched_out(event
, cpuctx
, ctx
);
1155 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1156 cpuctx
->exclusive
= 0;
1160 * Cross CPU call to remove a performance event
1162 * We disable the event on the hardware level first. After that we
1163 * remove it from the context list.
1165 static int __perf_remove_from_context(void *info
)
1167 struct perf_event
*event
= info
;
1168 struct perf_event_context
*ctx
= event
->ctx
;
1169 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1171 raw_spin_lock(&ctx
->lock
);
1172 event_sched_out(event
, cpuctx
, ctx
);
1173 list_del_event(event
, ctx
);
1174 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1176 cpuctx
->task_ctx
= NULL
;
1178 raw_spin_unlock(&ctx
->lock
);
1185 * Remove the event from a task's (or a CPU's) list of events.
1187 * CPU events are removed with a smp call. For task events we only
1188 * call when the task is on a CPU.
1190 * If event->ctx is a cloned context, callers must make sure that
1191 * every task struct that event->ctx->task could possibly point to
1192 * remains valid. This is OK when called from perf_release since
1193 * that only calls us on the top-level context, which can't be a clone.
1194 * When called from perf_event_exit_task, it's OK because the
1195 * context has been detached from its task.
1197 static void perf_remove_from_context(struct perf_event
*event
)
1199 struct perf_event_context
*ctx
= event
->ctx
;
1200 struct task_struct
*task
= ctx
->task
;
1202 lockdep_assert_held(&ctx
->mutex
);
1206 * Per cpu events are removed via an smp call and
1207 * the removal is always successful.
1209 cpu_function_call(event
->cpu
, __perf_remove_from_context
, event
);
1214 if (!task_function_call(task
, __perf_remove_from_context
, event
))
1217 raw_spin_lock_irq(&ctx
->lock
);
1219 * If we failed to find a running task, but find the context active now
1220 * that we've acquired the ctx->lock, retry.
1222 if (ctx
->is_active
) {
1223 raw_spin_unlock_irq(&ctx
->lock
);
1228 * Since the task isn't running, its safe to remove the event, us
1229 * holding the ctx->lock ensures the task won't get scheduled in.
1231 list_del_event(event
, ctx
);
1232 raw_spin_unlock_irq(&ctx
->lock
);
1236 * Cross CPU call to disable a performance event
1238 static int __perf_event_disable(void *info
)
1240 struct perf_event
*event
= info
;
1241 struct perf_event_context
*ctx
= event
->ctx
;
1242 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1245 * If this is a per-task event, need to check whether this
1246 * event's task is the current task on this cpu.
1248 * Can trigger due to concurrent perf_event_context_sched_out()
1249 * flipping contexts around.
1251 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1254 raw_spin_lock(&ctx
->lock
);
1257 * If the event is on, turn it off.
1258 * If it is in error state, leave it in error state.
1260 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1261 update_context_time(ctx
);
1262 update_cgrp_time_from_event(event
);
1263 update_group_times(event
);
1264 if (event
== event
->group_leader
)
1265 group_sched_out(event
, cpuctx
, ctx
);
1267 event_sched_out(event
, cpuctx
, ctx
);
1268 event
->state
= PERF_EVENT_STATE_OFF
;
1271 raw_spin_unlock(&ctx
->lock
);
1279 * If event->ctx is a cloned context, callers must make sure that
1280 * every task struct that event->ctx->task could possibly point to
1281 * remains valid. This condition is satisifed when called through
1282 * perf_event_for_each_child or perf_event_for_each because they
1283 * hold the top-level event's child_mutex, so any descendant that
1284 * goes to exit will block in sync_child_event.
1285 * When called from perf_pending_event it's OK because event->ctx
1286 * is the current context on this CPU and preemption is disabled,
1287 * hence we can't get into perf_event_task_sched_out for this context.
1289 void perf_event_disable(struct perf_event
*event
)
1291 struct perf_event_context
*ctx
= event
->ctx
;
1292 struct task_struct
*task
= ctx
->task
;
1296 * Disable the event on the cpu that it's on
1298 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1303 if (!task_function_call(task
, __perf_event_disable
, event
))
1306 raw_spin_lock_irq(&ctx
->lock
);
1308 * If the event is still active, we need to retry the cross-call.
1310 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1311 raw_spin_unlock_irq(&ctx
->lock
);
1313 * Reload the task pointer, it might have been changed by
1314 * a concurrent perf_event_context_sched_out().
1321 * Since we have the lock this context can't be scheduled
1322 * in, so we can change the state safely.
1324 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1325 update_group_times(event
);
1326 event
->state
= PERF_EVENT_STATE_OFF
;
1328 raw_spin_unlock_irq(&ctx
->lock
);
1330 EXPORT_SYMBOL_GPL(perf_event_disable
);
1332 static void perf_set_shadow_time(struct perf_event
*event
,
1333 struct perf_event_context
*ctx
,
1337 * use the correct time source for the time snapshot
1339 * We could get by without this by leveraging the
1340 * fact that to get to this function, the caller
1341 * has most likely already called update_context_time()
1342 * and update_cgrp_time_xx() and thus both timestamp
1343 * are identical (or very close). Given that tstamp is,
1344 * already adjusted for cgroup, we could say that:
1345 * tstamp - ctx->timestamp
1347 * tstamp - cgrp->timestamp.
1349 * Then, in perf_output_read(), the calculation would
1350 * work with no changes because:
1351 * - event is guaranteed scheduled in
1352 * - no scheduled out in between
1353 * - thus the timestamp would be the same
1355 * But this is a bit hairy.
1357 * So instead, we have an explicit cgroup call to remain
1358 * within the time time source all along. We believe it
1359 * is cleaner and simpler to understand.
1361 if (is_cgroup_event(event
))
1362 perf_cgroup_set_shadow_time(event
, tstamp
);
1364 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1367 #define MAX_INTERRUPTS (~0ULL)
1369 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1372 event_sched_in(struct perf_event
*event
,
1373 struct perf_cpu_context
*cpuctx
,
1374 struct perf_event_context
*ctx
)
1376 u64 tstamp
= perf_event_time(event
);
1378 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1381 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1382 event
->oncpu
= smp_processor_id();
1385 * Unthrottle events, since we scheduled we might have missed several
1386 * ticks already, also for a heavily scheduling task there is little
1387 * guarantee it'll get a tick in a timely manner.
1389 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1390 perf_log_throttle(event
, 1);
1391 event
->hw
.interrupts
= 0;
1395 * The new state must be visible before we turn it on in the hardware:
1399 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1400 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1405 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1407 perf_set_shadow_time(event
, ctx
, tstamp
);
1409 if (!is_software_event(event
))
1410 cpuctx
->active_oncpu
++;
1412 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1415 if (event
->attr
.exclusive
)
1416 cpuctx
->exclusive
= 1;
1422 group_sched_in(struct perf_event
*group_event
,
1423 struct perf_cpu_context
*cpuctx
,
1424 struct perf_event_context
*ctx
)
1426 struct perf_event
*event
, *partial_group
= NULL
;
1427 struct pmu
*pmu
= group_event
->pmu
;
1428 u64 now
= ctx
->time
;
1429 bool simulate
= false;
1431 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1434 pmu
->start_txn(pmu
);
1436 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1437 pmu
->cancel_txn(pmu
);
1442 * Schedule in siblings as one group (if any):
1444 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1445 if (event_sched_in(event
, cpuctx
, ctx
)) {
1446 partial_group
= event
;
1451 if (!pmu
->commit_txn(pmu
))
1456 * Groups can be scheduled in as one unit only, so undo any
1457 * partial group before returning:
1458 * The events up to the failed event are scheduled out normally,
1459 * tstamp_stopped will be updated.
1461 * The failed events and the remaining siblings need to have
1462 * their timings updated as if they had gone thru event_sched_in()
1463 * and event_sched_out(). This is required to get consistent timings
1464 * across the group. This also takes care of the case where the group
1465 * could never be scheduled by ensuring tstamp_stopped is set to mark
1466 * the time the event was actually stopped, such that time delta
1467 * calculation in update_event_times() is correct.
1469 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1470 if (event
== partial_group
)
1474 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1475 event
->tstamp_stopped
= now
;
1477 event_sched_out(event
, cpuctx
, ctx
);
1480 event_sched_out(group_event
, cpuctx
, ctx
);
1482 pmu
->cancel_txn(pmu
);
1488 * Work out whether we can put this event group on the CPU now.
1490 static int group_can_go_on(struct perf_event
*event
,
1491 struct perf_cpu_context
*cpuctx
,
1495 * Groups consisting entirely of software events can always go on.
1497 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1500 * If an exclusive group is already on, no other hardware
1503 if (cpuctx
->exclusive
)
1506 * If this group is exclusive and there are already
1507 * events on the CPU, it can't go on.
1509 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1512 * Otherwise, try to add it if all previous groups were able
1518 static void add_event_to_ctx(struct perf_event
*event
,
1519 struct perf_event_context
*ctx
)
1521 u64 tstamp
= perf_event_time(event
);
1523 list_add_event(event
, ctx
);
1524 perf_group_attach(event
);
1525 event
->tstamp_enabled
= tstamp
;
1526 event
->tstamp_running
= tstamp
;
1527 event
->tstamp_stopped
= tstamp
;
1530 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
1532 ctx_sched_in(struct perf_event_context
*ctx
,
1533 struct perf_cpu_context
*cpuctx
,
1534 enum event_type_t event_type
,
1535 struct task_struct
*task
);
1537 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
1538 struct perf_event_context
*ctx
,
1539 struct task_struct
*task
)
1541 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
1543 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
1544 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
1546 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
1550 * Cross CPU call to install and enable a performance event
1552 * Must be called with ctx->mutex held
1554 static int __perf_install_in_context(void *info
)
1556 struct perf_event
*event
= info
;
1557 struct perf_event_context
*ctx
= event
->ctx
;
1558 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1559 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
1560 struct task_struct
*task
= current
;
1562 perf_ctx_lock(cpuctx
, task_ctx
);
1563 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1566 * If there was an active task_ctx schedule it out.
1569 task_ctx_sched_out(task_ctx
);
1572 * If the context we're installing events in is not the
1573 * active task_ctx, flip them.
1575 if (ctx
->task
&& task_ctx
!= ctx
) {
1577 raw_spin_unlock(&task_ctx
->lock
);
1578 raw_spin_lock(&ctx
->lock
);
1583 cpuctx
->task_ctx
= task_ctx
;
1584 task
= task_ctx
->task
;
1587 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
1589 update_context_time(ctx
);
1591 * update cgrp time only if current cgrp
1592 * matches event->cgrp. Must be done before
1593 * calling add_event_to_ctx()
1595 update_cgrp_time_from_event(event
);
1597 add_event_to_ctx(event
, ctx
);
1600 * Schedule everything back in
1602 perf_event_sched_in(cpuctx
, task_ctx
, task
);
1604 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1605 perf_ctx_unlock(cpuctx
, task_ctx
);
1611 * Attach a performance event to a context
1613 * First we add the event to the list with the hardware enable bit
1614 * in event->hw_config cleared.
1616 * If the event is attached to a task which is on a CPU we use a smp
1617 * call to enable it in the task context. The task might have been
1618 * scheduled away, but we check this in the smp call again.
1621 perf_install_in_context(struct perf_event_context
*ctx
,
1622 struct perf_event
*event
,
1625 struct task_struct
*task
= ctx
->task
;
1627 lockdep_assert_held(&ctx
->mutex
);
1633 * Per cpu events are installed via an smp call and
1634 * the install is always successful.
1636 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1641 if (!task_function_call(task
, __perf_install_in_context
, event
))
1644 raw_spin_lock_irq(&ctx
->lock
);
1646 * If we failed to find a running task, but find the context active now
1647 * that we've acquired the ctx->lock, retry.
1649 if (ctx
->is_active
) {
1650 raw_spin_unlock_irq(&ctx
->lock
);
1655 * Since the task isn't running, its safe to add the event, us holding
1656 * the ctx->lock ensures the task won't get scheduled in.
1658 add_event_to_ctx(event
, ctx
);
1659 raw_spin_unlock_irq(&ctx
->lock
);
1663 * Put a event into inactive state and update time fields.
1664 * Enabling the leader of a group effectively enables all
1665 * the group members that aren't explicitly disabled, so we
1666 * have to update their ->tstamp_enabled also.
1667 * Note: this works for group members as well as group leaders
1668 * since the non-leader members' sibling_lists will be empty.
1670 static void __perf_event_mark_enabled(struct perf_event
*event
)
1672 struct perf_event
*sub
;
1673 u64 tstamp
= perf_event_time(event
);
1675 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1676 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1677 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1678 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1679 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
1684 * Cross CPU call to enable a performance event
1686 static int __perf_event_enable(void *info
)
1688 struct perf_event
*event
= info
;
1689 struct perf_event_context
*ctx
= event
->ctx
;
1690 struct perf_event
*leader
= event
->group_leader
;
1691 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1694 if (WARN_ON_ONCE(!ctx
->is_active
))
1697 raw_spin_lock(&ctx
->lock
);
1698 update_context_time(ctx
);
1700 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1704 * set current task's cgroup time reference point
1706 perf_cgroup_set_timestamp(current
, ctx
);
1708 __perf_event_mark_enabled(event
);
1710 if (!event_filter_match(event
)) {
1711 if (is_cgroup_event(event
))
1712 perf_cgroup_defer_enabled(event
);
1717 * If the event is in a group and isn't the group leader,
1718 * then don't put it on unless the group is on.
1720 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
1723 if (!group_can_go_on(event
, cpuctx
, 1)) {
1726 if (event
== leader
)
1727 err
= group_sched_in(event
, cpuctx
, ctx
);
1729 err
= event_sched_in(event
, cpuctx
, ctx
);
1734 * If this event can't go on and it's part of a
1735 * group, then the whole group has to come off.
1737 if (leader
!= event
)
1738 group_sched_out(leader
, cpuctx
, ctx
);
1739 if (leader
->attr
.pinned
) {
1740 update_group_times(leader
);
1741 leader
->state
= PERF_EVENT_STATE_ERROR
;
1746 raw_spin_unlock(&ctx
->lock
);
1754 * If event->ctx is a cloned context, callers must make sure that
1755 * every task struct that event->ctx->task could possibly point to
1756 * remains valid. This condition is satisfied when called through
1757 * perf_event_for_each_child or perf_event_for_each as described
1758 * for perf_event_disable.
1760 void perf_event_enable(struct perf_event
*event
)
1762 struct perf_event_context
*ctx
= event
->ctx
;
1763 struct task_struct
*task
= ctx
->task
;
1767 * Enable the event on the cpu that it's on
1769 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
1773 raw_spin_lock_irq(&ctx
->lock
);
1774 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
1778 * If the event is in error state, clear that first.
1779 * That way, if we see the event in error state below, we
1780 * know that it has gone back into error state, as distinct
1781 * from the task having been scheduled away before the
1782 * cross-call arrived.
1784 if (event
->state
== PERF_EVENT_STATE_ERROR
)
1785 event
->state
= PERF_EVENT_STATE_OFF
;
1788 if (!ctx
->is_active
) {
1789 __perf_event_mark_enabled(event
);
1793 raw_spin_unlock_irq(&ctx
->lock
);
1795 if (!task_function_call(task
, __perf_event_enable
, event
))
1798 raw_spin_lock_irq(&ctx
->lock
);
1801 * If the context is active and the event is still off,
1802 * we need to retry the cross-call.
1804 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
1806 * task could have been flipped by a concurrent
1807 * perf_event_context_sched_out()
1814 raw_spin_unlock_irq(&ctx
->lock
);
1816 EXPORT_SYMBOL_GPL(perf_event_enable
);
1818 int perf_event_refresh(struct perf_event
*event
, int refresh
)
1821 * not supported on inherited events
1823 if (event
->attr
.inherit
|| !is_sampling_event(event
))
1826 atomic_add(refresh
, &event
->event_limit
);
1827 perf_event_enable(event
);
1831 EXPORT_SYMBOL_GPL(perf_event_refresh
);
1833 static void ctx_sched_out(struct perf_event_context
*ctx
,
1834 struct perf_cpu_context
*cpuctx
,
1835 enum event_type_t event_type
)
1837 struct perf_event
*event
;
1838 int is_active
= ctx
->is_active
;
1840 ctx
->is_active
&= ~event_type
;
1841 if (likely(!ctx
->nr_events
))
1844 update_context_time(ctx
);
1845 update_cgrp_time_from_cpuctx(cpuctx
);
1846 if (!ctx
->nr_active
)
1849 perf_pmu_disable(ctx
->pmu
);
1850 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
1851 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
1852 group_sched_out(event
, cpuctx
, ctx
);
1855 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
1856 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
1857 group_sched_out(event
, cpuctx
, ctx
);
1859 perf_pmu_enable(ctx
->pmu
);
1863 * Test whether two contexts are equivalent, i.e. whether they
1864 * have both been cloned from the same version of the same context
1865 * and they both have the same number of enabled events.
1866 * If the number of enabled events is the same, then the set
1867 * of enabled events should be the same, because these are both
1868 * inherited contexts, therefore we can't access individual events
1869 * in them directly with an fd; we can only enable/disable all
1870 * events via prctl, or enable/disable all events in a family
1871 * via ioctl, which will have the same effect on both contexts.
1873 static int context_equiv(struct perf_event_context
*ctx1
,
1874 struct perf_event_context
*ctx2
)
1876 return ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
1877 && ctx1
->parent_gen
== ctx2
->parent_gen
1878 && !ctx1
->pin_count
&& !ctx2
->pin_count
;
1881 static void __perf_event_sync_stat(struct perf_event
*event
,
1882 struct perf_event
*next_event
)
1886 if (!event
->attr
.inherit_stat
)
1890 * Update the event value, we cannot use perf_event_read()
1891 * because we're in the middle of a context switch and have IRQs
1892 * disabled, which upsets smp_call_function_single(), however
1893 * we know the event must be on the current CPU, therefore we
1894 * don't need to use it.
1896 switch (event
->state
) {
1897 case PERF_EVENT_STATE_ACTIVE
:
1898 event
->pmu
->read(event
);
1901 case PERF_EVENT_STATE_INACTIVE
:
1902 update_event_times(event
);
1910 * In order to keep per-task stats reliable we need to flip the event
1911 * values when we flip the contexts.
1913 value
= local64_read(&next_event
->count
);
1914 value
= local64_xchg(&event
->count
, value
);
1915 local64_set(&next_event
->count
, value
);
1917 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
1918 swap(event
->total_time_running
, next_event
->total_time_running
);
1921 * Since we swizzled the values, update the user visible data too.
1923 perf_event_update_userpage(event
);
1924 perf_event_update_userpage(next_event
);
1927 #define list_next_entry(pos, member) \
1928 list_entry(pos->member.next, typeof(*pos), member)
1930 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
1931 struct perf_event_context
*next_ctx
)
1933 struct perf_event
*event
, *next_event
;
1938 update_context_time(ctx
);
1940 event
= list_first_entry(&ctx
->event_list
,
1941 struct perf_event
, event_entry
);
1943 next_event
= list_first_entry(&next_ctx
->event_list
,
1944 struct perf_event
, event_entry
);
1946 while (&event
->event_entry
!= &ctx
->event_list
&&
1947 &next_event
->event_entry
!= &next_ctx
->event_list
) {
1949 __perf_event_sync_stat(event
, next_event
);
1951 event
= list_next_entry(event
, event_entry
);
1952 next_event
= list_next_entry(next_event
, event_entry
);
1956 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
1957 struct task_struct
*next
)
1959 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
1960 struct perf_event_context
*next_ctx
;
1961 struct perf_event_context
*parent
;
1962 struct perf_cpu_context
*cpuctx
;
1968 cpuctx
= __get_cpu_context(ctx
);
1969 if (!cpuctx
->task_ctx
)
1973 parent
= rcu_dereference(ctx
->parent_ctx
);
1974 next_ctx
= next
->perf_event_ctxp
[ctxn
];
1975 if (parent
&& next_ctx
&&
1976 rcu_dereference(next_ctx
->parent_ctx
) == parent
) {
1978 * Looks like the two contexts are clones, so we might be
1979 * able to optimize the context switch. We lock both
1980 * contexts and check that they are clones under the
1981 * lock (including re-checking that neither has been
1982 * uncloned in the meantime). It doesn't matter which
1983 * order we take the locks because no other cpu could
1984 * be trying to lock both of these tasks.
1986 raw_spin_lock(&ctx
->lock
);
1987 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
1988 if (context_equiv(ctx
, next_ctx
)) {
1990 * XXX do we need a memory barrier of sorts
1991 * wrt to rcu_dereference() of perf_event_ctxp
1993 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
1994 next
->perf_event_ctxp
[ctxn
] = ctx
;
1996 next_ctx
->task
= task
;
1999 perf_event_sync_stat(ctx
, next_ctx
);
2001 raw_spin_unlock(&next_ctx
->lock
);
2002 raw_spin_unlock(&ctx
->lock
);
2007 raw_spin_lock(&ctx
->lock
);
2008 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2009 cpuctx
->task_ctx
= NULL
;
2010 raw_spin_unlock(&ctx
->lock
);
2014 #define for_each_task_context_nr(ctxn) \
2015 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2018 * Called from scheduler to remove the events of the current task,
2019 * with interrupts disabled.
2021 * We stop each event and update the event value in event->count.
2023 * This does not protect us against NMI, but disable()
2024 * sets the disabled bit in the control field of event _before_
2025 * accessing the event control register. If a NMI hits, then it will
2026 * not restart the event.
2028 void __perf_event_task_sched_out(struct task_struct
*task
,
2029 struct task_struct
*next
)
2033 for_each_task_context_nr(ctxn
)
2034 perf_event_context_sched_out(task
, ctxn
, next
);
2037 * if cgroup events exist on this CPU, then we need
2038 * to check if we have to switch out PMU state.
2039 * cgroup event are system-wide mode only
2041 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2042 perf_cgroup_sched_out(task
, next
);
2045 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2047 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2049 if (!cpuctx
->task_ctx
)
2052 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2055 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2056 cpuctx
->task_ctx
= NULL
;
2060 * Called with IRQs disabled
2062 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2063 enum event_type_t event_type
)
2065 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2069 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2070 struct perf_cpu_context
*cpuctx
)
2072 struct perf_event
*event
;
2074 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2075 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2077 if (!event_filter_match(event
))
2080 /* may need to reset tstamp_enabled */
2081 if (is_cgroup_event(event
))
2082 perf_cgroup_mark_enabled(event
, ctx
);
2084 if (group_can_go_on(event
, cpuctx
, 1))
2085 group_sched_in(event
, cpuctx
, ctx
);
2088 * If this pinned group hasn't been scheduled,
2089 * put it in error state.
2091 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2092 update_group_times(event
);
2093 event
->state
= PERF_EVENT_STATE_ERROR
;
2099 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2100 struct perf_cpu_context
*cpuctx
)
2102 struct perf_event
*event
;
2105 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2106 /* Ignore events in OFF or ERROR state */
2107 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2110 * Listen to the 'cpu' scheduling filter constraint
2113 if (!event_filter_match(event
))
2116 /* may need to reset tstamp_enabled */
2117 if (is_cgroup_event(event
))
2118 perf_cgroup_mark_enabled(event
, ctx
);
2120 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2121 if (group_sched_in(event
, cpuctx
, ctx
))
2128 ctx_sched_in(struct perf_event_context
*ctx
,
2129 struct perf_cpu_context
*cpuctx
,
2130 enum event_type_t event_type
,
2131 struct task_struct
*task
)
2134 int is_active
= ctx
->is_active
;
2136 ctx
->is_active
|= event_type
;
2137 if (likely(!ctx
->nr_events
))
2141 ctx
->timestamp
= now
;
2142 perf_cgroup_set_timestamp(task
, ctx
);
2144 * First go through the list and put on any pinned groups
2145 * in order to give them the best chance of going on.
2147 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2148 ctx_pinned_sched_in(ctx
, cpuctx
);
2150 /* Then walk through the lower prio flexible groups */
2151 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2152 ctx_flexible_sched_in(ctx
, cpuctx
);
2155 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2156 enum event_type_t event_type
,
2157 struct task_struct
*task
)
2159 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2161 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2164 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2165 struct task_struct
*task
)
2167 struct perf_cpu_context
*cpuctx
;
2169 cpuctx
= __get_cpu_context(ctx
);
2170 if (cpuctx
->task_ctx
== ctx
)
2173 perf_ctx_lock(cpuctx
, ctx
);
2174 perf_pmu_disable(ctx
->pmu
);
2176 * We want to keep the following priority order:
2177 * cpu pinned (that don't need to move), task pinned,
2178 * cpu flexible, task flexible.
2180 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2183 cpuctx
->task_ctx
= ctx
;
2185 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2187 perf_pmu_enable(ctx
->pmu
);
2188 perf_ctx_unlock(cpuctx
, ctx
);
2191 * Since these rotations are per-cpu, we need to ensure the
2192 * cpu-context we got scheduled on is actually rotating.
2194 perf_pmu_rotate_start(ctx
->pmu
);
2198 * Called from scheduler to add the events of the current task
2199 * with interrupts disabled.
2201 * We restore the event value and then enable it.
2203 * This does not protect us against NMI, but enable()
2204 * sets the enabled bit in the control field of event _before_
2205 * accessing the event control register. If a NMI hits, then it will
2206 * keep the event running.
2208 void __perf_event_task_sched_in(struct task_struct
*prev
,
2209 struct task_struct
*task
)
2211 struct perf_event_context
*ctx
;
2214 for_each_task_context_nr(ctxn
) {
2215 ctx
= task
->perf_event_ctxp
[ctxn
];
2219 perf_event_context_sched_in(ctx
, task
);
2222 * if cgroup events exist on this CPU, then we need
2223 * to check if we have to switch in PMU state.
2224 * cgroup event are system-wide mode only
2226 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2227 perf_cgroup_sched_in(prev
, task
);
2230 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2232 u64 frequency
= event
->attr
.sample_freq
;
2233 u64 sec
= NSEC_PER_SEC
;
2234 u64 divisor
, dividend
;
2236 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2238 count_fls
= fls64(count
);
2239 nsec_fls
= fls64(nsec
);
2240 frequency_fls
= fls64(frequency
);
2244 * We got @count in @nsec, with a target of sample_freq HZ
2245 * the target period becomes:
2248 * period = -------------------
2249 * @nsec * sample_freq
2254 * Reduce accuracy by one bit such that @a and @b converge
2255 * to a similar magnitude.
2257 #define REDUCE_FLS(a, b) \
2259 if (a##_fls > b##_fls) { \
2269 * Reduce accuracy until either term fits in a u64, then proceed with
2270 * the other, so that finally we can do a u64/u64 division.
2272 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2273 REDUCE_FLS(nsec
, frequency
);
2274 REDUCE_FLS(sec
, count
);
2277 if (count_fls
+ sec_fls
> 64) {
2278 divisor
= nsec
* frequency
;
2280 while (count_fls
+ sec_fls
> 64) {
2281 REDUCE_FLS(count
, sec
);
2285 dividend
= count
* sec
;
2287 dividend
= count
* sec
;
2289 while (nsec_fls
+ frequency_fls
> 64) {
2290 REDUCE_FLS(nsec
, frequency
);
2294 divisor
= nsec
* frequency
;
2300 return div64_u64(dividend
, divisor
);
2303 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2305 struct hw_perf_event
*hwc
= &event
->hw
;
2306 s64 period
, sample_period
;
2309 period
= perf_calculate_period(event
, nsec
, count
);
2311 delta
= (s64
)(period
- hwc
->sample_period
);
2312 delta
= (delta
+ 7) / 8; /* low pass filter */
2314 sample_period
= hwc
->sample_period
+ delta
;
2319 hwc
->sample_period
= sample_period
;
2321 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2322 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2323 local64_set(&hwc
->period_left
, 0);
2324 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2328 static void perf_ctx_adjust_freq(struct perf_event_context
*ctx
, u64 period
)
2330 struct perf_event
*event
;
2331 struct hw_perf_event
*hwc
;
2332 u64 interrupts
, now
;
2338 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2339 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2342 if (!event_filter_match(event
))
2347 interrupts
= hwc
->interrupts
;
2348 hwc
->interrupts
= 0;
2351 * unthrottle events on the tick
2353 if (interrupts
== MAX_INTERRUPTS
) {
2354 perf_log_throttle(event
, 1);
2355 event
->pmu
->start(event
, 0);
2358 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2361 event
->pmu
->read(event
);
2362 now
= local64_read(&event
->count
);
2363 delta
= now
- hwc
->freq_count_stamp
;
2364 hwc
->freq_count_stamp
= now
;
2367 perf_adjust_period(event
, period
, delta
);
2372 * Round-robin a context's events:
2374 static void rotate_ctx(struct perf_event_context
*ctx
)
2377 * Rotate the first entry last of non-pinned groups. Rotation might be
2378 * disabled by the inheritance code.
2380 if (!ctx
->rotate_disable
)
2381 list_rotate_left(&ctx
->flexible_groups
);
2385 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2386 * because they're strictly cpu affine and rotate_start is called with IRQs
2387 * disabled, while rotate_context is called from IRQ context.
2389 static void perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2391 u64 interval
= (u64
)cpuctx
->jiffies_interval
* TICK_NSEC
;
2392 struct perf_event_context
*ctx
= NULL
;
2393 int rotate
= 0, remove
= 1, freq
= 0;
2395 if (cpuctx
->ctx
.nr_events
) {
2397 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2399 if (cpuctx
->ctx
.nr_freq
)
2403 ctx
= cpuctx
->task_ctx
;
2404 if (ctx
&& ctx
->nr_events
) {
2406 if (ctx
->nr_events
!= ctx
->nr_active
)
2412 if (!rotate
&& !freq
)
2415 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2416 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2419 perf_ctx_adjust_freq(&cpuctx
->ctx
, interval
);
2421 perf_ctx_adjust_freq(ctx
, interval
);
2425 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2427 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
2429 rotate_ctx(&cpuctx
->ctx
);
2433 perf_event_sched_in(cpuctx
, ctx
, current
);
2436 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2437 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2441 list_del_init(&cpuctx
->rotation_list
);
2444 void perf_event_task_tick(void)
2446 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2447 struct perf_cpu_context
*cpuctx
, *tmp
;
2449 WARN_ON(!irqs_disabled());
2451 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2452 if (cpuctx
->jiffies_interval
== 1 ||
2453 !(jiffies
% cpuctx
->jiffies_interval
))
2454 perf_rotate_context(cpuctx
);
2458 static int event_enable_on_exec(struct perf_event
*event
,
2459 struct perf_event_context
*ctx
)
2461 if (!event
->attr
.enable_on_exec
)
2464 event
->attr
.enable_on_exec
= 0;
2465 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2468 __perf_event_mark_enabled(event
);
2474 * Enable all of a task's events that have been marked enable-on-exec.
2475 * This expects task == current.
2477 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2479 struct perf_event
*event
;
2480 unsigned long flags
;
2484 local_irq_save(flags
);
2485 if (!ctx
|| !ctx
->nr_events
)
2489 * We must ctxsw out cgroup events to avoid conflict
2490 * when invoking perf_task_event_sched_in() later on
2491 * in this function. Otherwise we end up trying to
2492 * ctxswin cgroup events which are already scheduled
2495 perf_cgroup_sched_out(current
, NULL
);
2497 raw_spin_lock(&ctx
->lock
);
2498 task_ctx_sched_out(ctx
);
2500 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
2501 ret
= event_enable_on_exec(event
, ctx
);
2507 * Unclone this context if we enabled any event.
2512 raw_spin_unlock(&ctx
->lock
);
2515 * Also calls ctxswin for cgroup events, if any:
2517 perf_event_context_sched_in(ctx
, ctx
->task
);
2519 local_irq_restore(flags
);
2523 * Cross CPU call to read the hardware event
2525 static void __perf_event_read(void *info
)
2527 struct perf_event
*event
= info
;
2528 struct perf_event_context
*ctx
= event
->ctx
;
2529 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2532 * If this is a task context, we need to check whether it is
2533 * the current task context of this cpu. If not it has been
2534 * scheduled out before the smp call arrived. In that case
2535 * event->count would have been updated to a recent sample
2536 * when the event was scheduled out.
2538 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2541 raw_spin_lock(&ctx
->lock
);
2542 if (ctx
->is_active
) {
2543 update_context_time(ctx
);
2544 update_cgrp_time_from_event(event
);
2546 update_event_times(event
);
2547 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2548 event
->pmu
->read(event
);
2549 raw_spin_unlock(&ctx
->lock
);
2552 static inline u64
perf_event_count(struct perf_event
*event
)
2554 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2557 static u64
perf_event_read(struct perf_event
*event
)
2560 * If event is enabled and currently active on a CPU, update the
2561 * value in the event structure:
2563 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2564 smp_call_function_single(event
->oncpu
,
2565 __perf_event_read
, event
, 1);
2566 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2567 struct perf_event_context
*ctx
= event
->ctx
;
2568 unsigned long flags
;
2570 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2572 * may read while context is not active
2573 * (e.g., thread is blocked), in that case
2574 * we cannot update context time
2576 if (ctx
->is_active
) {
2577 update_context_time(ctx
);
2578 update_cgrp_time_from_event(event
);
2580 update_event_times(event
);
2581 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2584 return perf_event_count(event
);
2588 * Initialize the perf_event context in a task_struct:
2590 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2592 raw_spin_lock_init(&ctx
->lock
);
2593 mutex_init(&ctx
->mutex
);
2594 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2595 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2596 INIT_LIST_HEAD(&ctx
->event_list
);
2597 atomic_set(&ctx
->refcount
, 1);
2600 static struct perf_event_context
*
2601 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2603 struct perf_event_context
*ctx
;
2605 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2609 __perf_event_init_context(ctx
);
2612 get_task_struct(task
);
2619 static struct task_struct
*
2620 find_lively_task_by_vpid(pid_t vpid
)
2622 struct task_struct
*task
;
2629 task
= find_task_by_vpid(vpid
);
2631 get_task_struct(task
);
2635 return ERR_PTR(-ESRCH
);
2637 /* Reuse ptrace permission checks for now. */
2639 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2644 put_task_struct(task
);
2645 return ERR_PTR(err
);
2650 * Returns a matching context with refcount and pincount.
2652 static struct perf_event_context
*
2653 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2655 struct perf_event_context
*ctx
;
2656 struct perf_cpu_context
*cpuctx
;
2657 unsigned long flags
;
2661 /* Must be root to operate on a CPU event: */
2662 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2663 return ERR_PTR(-EACCES
);
2666 * We could be clever and allow to attach a event to an
2667 * offline CPU and activate it when the CPU comes up, but
2670 if (!cpu_online(cpu
))
2671 return ERR_PTR(-ENODEV
);
2673 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2682 ctxn
= pmu
->task_ctx_nr
;
2687 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2691 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2693 ctx
= alloc_perf_context(pmu
, task
);
2699 mutex_lock(&task
->perf_event_mutex
);
2701 * If it has already passed perf_event_exit_task().
2702 * we must see PF_EXITING, it takes this mutex too.
2704 if (task
->flags
& PF_EXITING
)
2706 else if (task
->perf_event_ctxp
[ctxn
])
2711 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2713 mutex_unlock(&task
->perf_event_mutex
);
2715 if (unlikely(err
)) {
2727 return ERR_PTR(err
);
2730 static void perf_event_free_filter(struct perf_event
*event
);
2732 static void free_event_rcu(struct rcu_head
*head
)
2734 struct perf_event
*event
;
2736 event
= container_of(head
, struct perf_event
, rcu_head
);
2738 put_pid_ns(event
->ns
);
2739 perf_event_free_filter(event
);
2743 static void ring_buffer_put(struct ring_buffer
*rb
);
2745 static void free_event(struct perf_event
*event
)
2747 irq_work_sync(&event
->pending
);
2749 if (!event
->parent
) {
2750 if (event
->attach_state
& PERF_ATTACH_TASK
)
2751 jump_label_dec_deferred(&perf_sched_events
);
2752 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2753 atomic_dec(&nr_mmap_events
);
2754 if (event
->attr
.comm
)
2755 atomic_dec(&nr_comm_events
);
2756 if (event
->attr
.task
)
2757 atomic_dec(&nr_task_events
);
2758 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2759 put_callchain_buffers();
2760 if (is_cgroup_event(event
)) {
2761 atomic_dec(&per_cpu(perf_cgroup_events
, event
->cpu
));
2762 jump_label_dec_deferred(&perf_sched_events
);
2767 ring_buffer_put(event
->rb
);
2771 if (is_cgroup_event(event
))
2772 perf_detach_cgroup(event
);
2775 event
->destroy(event
);
2778 put_ctx(event
->ctx
);
2780 call_rcu(&event
->rcu_head
, free_event_rcu
);
2783 int perf_event_release_kernel(struct perf_event
*event
)
2785 struct perf_event_context
*ctx
= event
->ctx
;
2787 WARN_ON_ONCE(ctx
->parent_ctx
);
2789 * There are two ways this annotation is useful:
2791 * 1) there is a lock recursion from perf_event_exit_task
2792 * see the comment there.
2794 * 2) there is a lock-inversion with mmap_sem through
2795 * perf_event_read_group(), which takes faults while
2796 * holding ctx->mutex, however this is called after
2797 * the last filedesc died, so there is no possibility
2798 * to trigger the AB-BA case.
2800 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2801 raw_spin_lock_irq(&ctx
->lock
);
2802 perf_group_detach(event
);
2803 raw_spin_unlock_irq(&ctx
->lock
);
2804 perf_remove_from_context(event
);
2805 mutex_unlock(&ctx
->mutex
);
2811 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2814 * Called when the last reference to the file is gone.
2816 static int perf_release(struct inode
*inode
, struct file
*file
)
2818 struct perf_event
*event
= file
->private_data
;
2819 struct task_struct
*owner
;
2821 file
->private_data
= NULL
;
2824 owner
= ACCESS_ONCE(event
->owner
);
2826 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2827 * !owner it means the list deletion is complete and we can indeed
2828 * free this event, otherwise we need to serialize on
2829 * owner->perf_event_mutex.
2831 smp_read_barrier_depends();
2834 * Since delayed_put_task_struct() also drops the last
2835 * task reference we can safely take a new reference
2836 * while holding the rcu_read_lock().
2838 get_task_struct(owner
);
2843 mutex_lock(&owner
->perf_event_mutex
);
2845 * We have to re-check the event->owner field, if it is cleared
2846 * we raced with perf_event_exit_task(), acquiring the mutex
2847 * ensured they're done, and we can proceed with freeing the
2851 list_del_init(&event
->owner_entry
);
2852 mutex_unlock(&owner
->perf_event_mutex
);
2853 put_task_struct(owner
);
2856 return perf_event_release_kernel(event
);
2859 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
2861 struct perf_event
*child
;
2867 mutex_lock(&event
->child_mutex
);
2868 total
+= perf_event_read(event
);
2869 *enabled
+= event
->total_time_enabled
+
2870 atomic64_read(&event
->child_total_time_enabled
);
2871 *running
+= event
->total_time_running
+
2872 atomic64_read(&event
->child_total_time_running
);
2874 list_for_each_entry(child
, &event
->child_list
, child_list
) {
2875 total
+= perf_event_read(child
);
2876 *enabled
+= child
->total_time_enabled
;
2877 *running
+= child
->total_time_running
;
2879 mutex_unlock(&event
->child_mutex
);
2883 EXPORT_SYMBOL_GPL(perf_event_read_value
);
2885 static int perf_event_read_group(struct perf_event
*event
,
2886 u64 read_format
, char __user
*buf
)
2888 struct perf_event
*leader
= event
->group_leader
, *sub
;
2889 int n
= 0, size
= 0, ret
= -EFAULT
;
2890 struct perf_event_context
*ctx
= leader
->ctx
;
2892 u64 count
, enabled
, running
;
2894 mutex_lock(&ctx
->mutex
);
2895 count
= perf_event_read_value(leader
, &enabled
, &running
);
2897 values
[n
++] = 1 + leader
->nr_siblings
;
2898 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2899 values
[n
++] = enabled
;
2900 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2901 values
[n
++] = running
;
2902 values
[n
++] = count
;
2903 if (read_format
& PERF_FORMAT_ID
)
2904 values
[n
++] = primary_event_id(leader
);
2906 size
= n
* sizeof(u64
);
2908 if (copy_to_user(buf
, values
, size
))
2913 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
2916 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
2917 if (read_format
& PERF_FORMAT_ID
)
2918 values
[n
++] = primary_event_id(sub
);
2920 size
= n
* sizeof(u64
);
2922 if (copy_to_user(buf
+ ret
, values
, size
)) {
2930 mutex_unlock(&ctx
->mutex
);
2935 static int perf_event_read_one(struct perf_event
*event
,
2936 u64 read_format
, char __user
*buf
)
2938 u64 enabled
, running
;
2942 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
2943 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2944 values
[n
++] = enabled
;
2945 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2946 values
[n
++] = running
;
2947 if (read_format
& PERF_FORMAT_ID
)
2948 values
[n
++] = primary_event_id(event
);
2950 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2953 return n
* sizeof(u64
);
2957 * Read the performance event - simple non blocking version for now
2960 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2962 u64 read_format
= event
->attr
.read_format
;
2966 * Return end-of-file for a read on a event that is in
2967 * error state (i.e. because it was pinned but it couldn't be
2968 * scheduled on to the CPU at some point).
2970 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2973 if (count
< event
->read_size
)
2976 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2977 if (read_format
& PERF_FORMAT_GROUP
)
2978 ret
= perf_event_read_group(event
, read_format
, buf
);
2980 ret
= perf_event_read_one(event
, read_format
, buf
);
2986 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2988 struct perf_event
*event
= file
->private_data
;
2990 return perf_read_hw(event
, buf
, count
);
2993 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
2995 struct perf_event
*event
= file
->private_data
;
2996 struct ring_buffer
*rb
;
2997 unsigned int events
= POLL_HUP
;
3000 * Race between perf_event_set_output() and perf_poll(): perf_poll()
3001 * grabs the rb reference but perf_event_set_output() overrides it.
3002 * Here is the timeline for two threads T1, T2:
3003 * t0: T1, rb = rcu_dereference(event->rb)
3004 * t1: T2, old_rb = event->rb
3005 * t2: T2, event->rb = new rb
3006 * t3: T2, ring_buffer_detach(old_rb)
3007 * t4: T1, ring_buffer_attach(rb1)
3008 * t5: T1, poll_wait(event->waitq)
3010 * To avoid this problem, we grab mmap_mutex in perf_poll()
3011 * thereby ensuring that the assignment of the new ring buffer
3012 * and the detachment of the old buffer appear atomic to perf_poll()
3014 mutex_lock(&event
->mmap_mutex
);
3017 rb
= rcu_dereference(event
->rb
);
3019 ring_buffer_attach(event
, rb
);
3020 events
= atomic_xchg(&rb
->poll
, 0);
3024 mutex_unlock(&event
->mmap_mutex
);
3026 poll_wait(file
, &event
->waitq
, wait
);
3031 static void perf_event_reset(struct perf_event
*event
)
3033 (void)perf_event_read(event
);
3034 local64_set(&event
->count
, 0);
3035 perf_event_update_userpage(event
);
3039 * Holding the top-level event's child_mutex means that any
3040 * descendant process that has inherited this event will block
3041 * in sync_child_event if it goes to exit, thus satisfying the
3042 * task existence requirements of perf_event_enable/disable.
3044 static void perf_event_for_each_child(struct perf_event
*event
,
3045 void (*func
)(struct perf_event
*))
3047 struct perf_event
*child
;
3049 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3050 mutex_lock(&event
->child_mutex
);
3052 list_for_each_entry(child
, &event
->child_list
, child_list
)
3054 mutex_unlock(&event
->child_mutex
);
3057 static void perf_event_for_each(struct perf_event
*event
,
3058 void (*func
)(struct perf_event
*))
3060 struct perf_event_context
*ctx
= event
->ctx
;
3061 struct perf_event
*sibling
;
3063 WARN_ON_ONCE(ctx
->parent_ctx
);
3064 mutex_lock(&ctx
->mutex
);
3065 event
= event
->group_leader
;
3067 perf_event_for_each_child(event
, func
);
3069 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3070 perf_event_for_each_child(event
, func
);
3071 mutex_unlock(&ctx
->mutex
);
3074 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3076 struct perf_event_context
*ctx
= event
->ctx
;
3080 if (!is_sampling_event(event
))
3083 if (copy_from_user(&value
, arg
, sizeof(value
)))
3089 raw_spin_lock_irq(&ctx
->lock
);
3090 if (event
->attr
.freq
) {
3091 if (value
> sysctl_perf_event_sample_rate
) {
3096 event
->attr
.sample_freq
= value
;
3098 event
->attr
.sample_period
= value
;
3099 event
->hw
.sample_period
= value
;
3102 raw_spin_unlock_irq(&ctx
->lock
);
3107 static const struct file_operations perf_fops
;
3109 static struct perf_event
*perf_fget_light(int fd
, int *fput_needed
)
3113 file
= fget_light(fd
, fput_needed
);
3115 return ERR_PTR(-EBADF
);
3117 if (file
->f_op
!= &perf_fops
) {
3118 fput_light(file
, *fput_needed
);
3120 return ERR_PTR(-EBADF
);
3123 return file
->private_data
;
3126 static int perf_event_set_output(struct perf_event
*event
,
3127 struct perf_event
*output_event
);
3128 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3130 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3132 struct perf_event
*event
= file
->private_data
;
3133 void (*func
)(struct perf_event
*);
3137 case PERF_EVENT_IOC_ENABLE
:
3138 func
= perf_event_enable
;
3140 case PERF_EVENT_IOC_DISABLE
:
3141 func
= perf_event_disable
;
3143 case PERF_EVENT_IOC_RESET
:
3144 func
= perf_event_reset
;
3147 case PERF_EVENT_IOC_REFRESH
:
3148 return perf_event_refresh(event
, arg
);
3150 case PERF_EVENT_IOC_PERIOD
:
3151 return perf_event_period(event
, (u64 __user
*)arg
);
3153 case PERF_EVENT_IOC_SET_OUTPUT
:
3155 struct perf_event
*output_event
= NULL
;
3156 int fput_needed
= 0;
3160 output_event
= perf_fget_light(arg
, &fput_needed
);
3161 if (IS_ERR(output_event
))
3162 return PTR_ERR(output_event
);
3165 ret
= perf_event_set_output(event
, output_event
);
3167 fput_light(output_event
->filp
, fput_needed
);
3172 case PERF_EVENT_IOC_SET_FILTER
:
3173 return perf_event_set_filter(event
, (void __user
*)arg
);
3179 if (flags
& PERF_IOC_FLAG_GROUP
)
3180 perf_event_for_each(event
, func
);
3182 perf_event_for_each_child(event
, func
);
3187 int perf_event_task_enable(void)
3189 struct perf_event
*event
;
3191 mutex_lock(¤t
->perf_event_mutex
);
3192 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3193 perf_event_for_each_child(event
, perf_event_enable
);
3194 mutex_unlock(¤t
->perf_event_mutex
);
3199 int perf_event_task_disable(void)
3201 struct perf_event
*event
;
3203 mutex_lock(¤t
->perf_event_mutex
);
3204 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3205 perf_event_for_each_child(event
, perf_event_disable
);
3206 mutex_unlock(¤t
->perf_event_mutex
);
3211 #ifndef PERF_EVENT_INDEX_OFFSET
3212 # define PERF_EVENT_INDEX_OFFSET 0
3215 static int perf_event_index(struct perf_event
*event
)
3217 if (event
->hw
.state
& PERF_HES_STOPPED
)
3220 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3223 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
3226 static void calc_timer_values(struct perf_event
*event
,
3233 ctx_time
= event
->shadow_ctx_time
+ now
;
3234 *enabled
= ctx_time
- event
->tstamp_enabled
;
3235 *running
= ctx_time
- event
->tstamp_running
;
3239 * Callers need to ensure there can be no nesting of this function, otherwise
3240 * the seqlock logic goes bad. We can not serialize this because the arch
3241 * code calls this from NMI context.
3243 void perf_event_update_userpage(struct perf_event
*event
)
3245 struct perf_event_mmap_page
*userpg
;
3246 struct ring_buffer
*rb
;
3247 u64 enabled
, running
;
3251 * compute total_time_enabled, total_time_running
3252 * based on snapshot values taken when the event
3253 * was last scheduled in.
3255 * we cannot simply called update_context_time()
3256 * because of locking issue as we can be called in
3259 calc_timer_values(event
, &enabled
, &running
);
3260 rb
= rcu_dereference(event
->rb
);
3264 userpg
= rb
->user_page
;
3267 * Disable preemption so as to not let the corresponding user-space
3268 * spin too long if we get preempted.
3273 userpg
->index
= perf_event_index(event
);
3274 userpg
->offset
= perf_event_count(event
);
3275 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3276 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3278 userpg
->time_enabled
= enabled
+
3279 atomic64_read(&event
->child_total_time_enabled
);
3281 userpg
->time_running
= running
+
3282 atomic64_read(&event
->child_total_time_running
);
3291 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3293 struct perf_event
*event
= vma
->vm_file
->private_data
;
3294 struct ring_buffer
*rb
;
3295 int ret
= VM_FAULT_SIGBUS
;
3297 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3298 if (vmf
->pgoff
== 0)
3304 rb
= rcu_dereference(event
->rb
);
3308 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3311 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3315 get_page(vmf
->page
);
3316 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3317 vmf
->page
->index
= vmf
->pgoff
;
3326 static void ring_buffer_attach(struct perf_event
*event
,
3327 struct ring_buffer
*rb
)
3329 unsigned long flags
;
3331 if (!list_empty(&event
->rb_entry
))
3334 spin_lock_irqsave(&rb
->event_lock
, flags
);
3335 if (!list_empty(&event
->rb_entry
))
3338 list_add(&event
->rb_entry
, &rb
->event_list
);
3340 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3343 static void ring_buffer_detach(struct perf_event
*event
,
3344 struct ring_buffer
*rb
)
3346 unsigned long flags
;
3348 if (list_empty(&event
->rb_entry
))
3351 spin_lock_irqsave(&rb
->event_lock
, flags
);
3352 list_del_init(&event
->rb_entry
);
3353 wake_up_all(&event
->waitq
);
3354 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3357 static void ring_buffer_wakeup(struct perf_event
*event
)
3359 struct ring_buffer
*rb
;
3362 rb
= rcu_dereference(event
->rb
);
3366 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
3367 wake_up_all(&event
->waitq
);
3373 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3375 struct ring_buffer
*rb
;
3377 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3381 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3383 struct ring_buffer
*rb
;
3386 rb
= rcu_dereference(event
->rb
);
3388 if (!atomic_inc_not_zero(&rb
->refcount
))
3396 static void ring_buffer_put(struct ring_buffer
*rb
)
3398 struct perf_event
*event
, *n
;
3399 unsigned long flags
;
3401 if (!atomic_dec_and_test(&rb
->refcount
))
3404 spin_lock_irqsave(&rb
->event_lock
, flags
);
3405 list_for_each_entry_safe(event
, n
, &rb
->event_list
, rb_entry
) {
3406 list_del_init(&event
->rb_entry
);
3407 wake_up_all(&event
->waitq
);
3409 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3411 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3414 static void perf_mmap_open(struct vm_area_struct
*vma
)
3416 struct perf_event
*event
= vma
->vm_file
->private_data
;
3418 atomic_inc(&event
->mmap_count
);
3421 static void perf_mmap_close(struct vm_area_struct
*vma
)
3423 struct perf_event
*event
= vma
->vm_file
->private_data
;
3425 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3426 unsigned long size
= perf_data_size(event
->rb
);
3427 struct user_struct
*user
= event
->mmap_user
;
3428 struct ring_buffer
*rb
= event
->rb
;
3430 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3431 vma
->vm_mm
->pinned_vm
-= event
->mmap_locked
;
3432 rcu_assign_pointer(event
->rb
, NULL
);
3433 ring_buffer_detach(event
, rb
);
3434 mutex_unlock(&event
->mmap_mutex
);
3436 ring_buffer_put(rb
);
3441 static const struct vm_operations_struct perf_mmap_vmops
= {
3442 .open
= perf_mmap_open
,
3443 .close
= perf_mmap_close
,
3444 .fault
= perf_mmap_fault
,
3445 .page_mkwrite
= perf_mmap_fault
,
3448 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3450 struct perf_event
*event
= file
->private_data
;
3451 unsigned long user_locked
, user_lock_limit
;
3452 struct user_struct
*user
= current_user();
3453 unsigned long locked
, lock_limit
;
3454 struct ring_buffer
*rb
;
3455 unsigned long vma_size
;
3456 unsigned long nr_pages
;
3457 long user_extra
, extra
;
3458 int ret
= 0, flags
= 0;
3461 * Don't allow mmap() of inherited per-task counters. This would
3462 * create a performance issue due to all children writing to the
3465 if (event
->cpu
== -1 && event
->attr
.inherit
)
3468 if (!(vma
->vm_flags
& VM_SHARED
))
3471 vma_size
= vma
->vm_end
- vma
->vm_start
;
3472 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3475 * If we have rb pages ensure they're a power-of-two number, so we
3476 * can do bitmasks instead of modulo.
3478 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3481 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3484 if (vma
->vm_pgoff
!= 0)
3487 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3488 mutex_lock(&event
->mmap_mutex
);
3490 if (event
->rb
->nr_pages
== nr_pages
)
3491 atomic_inc(&event
->rb
->refcount
);
3497 user_extra
= nr_pages
+ 1;
3498 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3501 * Increase the limit linearly with more CPUs:
3503 user_lock_limit
*= num_online_cpus();
3505 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3508 if (user_locked
> user_lock_limit
)
3509 extra
= user_locked
- user_lock_limit
;
3511 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3512 lock_limit
>>= PAGE_SHIFT
;
3513 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
3515 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3516 !capable(CAP_IPC_LOCK
)) {
3523 if (vma
->vm_flags
& VM_WRITE
)
3524 flags
|= RING_BUFFER_WRITABLE
;
3526 rb
= rb_alloc(nr_pages
,
3527 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
3534 rcu_assign_pointer(event
->rb
, rb
);
3536 atomic_long_add(user_extra
, &user
->locked_vm
);
3537 event
->mmap_locked
= extra
;
3538 event
->mmap_user
= get_current_user();
3539 vma
->vm_mm
->pinned_vm
+= event
->mmap_locked
;
3543 atomic_inc(&event
->mmap_count
);
3544 mutex_unlock(&event
->mmap_mutex
);
3546 vma
->vm_flags
|= VM_RESERVED
;
3547 vma
->vm_ops
= &perf_mmap_vmops
;
3552 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3554 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3555 struct perf_event
*event
= filp
->private_data
;
3558 mutex_lock(&inode
->i_mutex
);
3559 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3560 mutex_unlock(&inode
->i_mutex
);
3568 static const struct file_operations perf_fops
= {
3569 .llseek
= no_llseek
,
3570 .release
= perf_release
,
3573 .unlocked_ioctl
= perf_ioctl
,
3574 .compat_ioctl
= perf_ioctl
,
3576 .fasync
= perf_fasync
,
3582 * If there's data, ensure we set the poll() state and publish everything
3583 * to user-space before waking everybody up.
3586 void perf_event_wakeup(struct perf_event
*event
)
3588 ring_buffer_wakeup(event
);
3590 if (event
->pending_kill
) {
3591 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3592 event
->pending_kill
= 0;
3596 static void perf_pending_event(struct irq_work
*entry
)
3598 struct perf_event
*event
= container_of(entry
,
3599 struct perf_event
, pending
);
3601 if (event
->pending_disable
) {
3602 event
->pending_disable
= 0;
3603 __perf_event_disable(event
);
3606 if (event
->pending_wakeup
) {
3607 event
->pending_wakeup
= 0;
3608 perf_event_wakeup(event
);
3613 * We assume there is only KVM supporting the callbacks.
3614 * Later on, we might change it to a list if there is
3615 * another virtualization implementation supporting the callbacks.
3617 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3619 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3621 perf_guest_cbs
= cbs
;
3624 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3626 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3628 perf_guest_cbs
= NULL
;
3631 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3633 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3634 struct perf_sample_data
*data
,
3635 struct perf_event
*event
)
3637 u64 sample_type
= event
->attr
.sample_type
;
3639 data
->type
= sample_type
;
3640 header
->size
+= event
->id_header_size
;
3642 if (sample_type
& PERF_SAMPLE_TID
) {
3643 /* namespace issues */
3644 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3645 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3648 if (sample_type
& PERF_SAMPLE_TIME
)
3649 data
->time
= perf_clock();
3651 if (sample_type
& PERF_SAMPLE_ID
)
3652 data
->id
= primary_event_id(event
);
3654 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3655 data
->stream_id
= event
->id
;
3657 if (sample_type
& PERF_SAMPLE_CPU
) {
3658 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3659 data
->cpu_entry
.reserved
= 0;
3663 void perf_event_header__init_id(struct perf_event_header
*header
,
3664 struct perf_sample_data
*data
,
3665 struct perf_event
*event
)
3667 if (event
->attr
.sample_id_all
)
3668 __perf_event_header__init_id(header
, data
, event
);
3671 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
3672 struct perf_sample_data
*data
)
3674 u64 sample_type
= data
->type
;
3676 if (sample_type
& PERF_SAMPLE_TID
)
3677 perf_output_put(handle
, data
->tid_entry
);
3679 if (sample_type
& PERF_SAMPLE_TIME
)
3680 perf_output_put(handle
, data
->time
);
3682 if (sample_type
& PERF_SAMPLE_ID
)
3683 perf_output_put(handle
, data
->id
);
3685 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3686 perf_output_put(handle
, data
->stream_id
);
3688 if (sample_type
& PERF_SAMPLE_CPU
)
3689 perf_output_put(handle
, data
->cpu_entry
);
3692 void perf_event__output_id_sample(struct perf_event
*event
,
3693 struct perf_output_handle
*handle
,
3694 struct perf_sample_data
*sample
)
3696 if (event
->attr
.sample_id_all
)
3697 __perf_event__output_id_sample(handle
, sample
);
3700 static void perf_output_read_one(struct perf_output_handle
*handle
,
3701 struct perf_event
*event
,
3702 u64 enabled
, u64 running
)
3704 u64 read_format
= event
->attr
.read_format
;
3708 values
[n
++] = perf_event_count(event
);
3709 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3710 values
[n
++] = enabled
+
3711 atomic64_read(&event
->child_total_time_enabled
);
3713 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3714 values
[n
++] = running
+
3715 atomic64_read(&event
->child_total_time_running
);
3717 if (read_format
& PERF_FORMAT_ID
)
3718 values
[n
++] = primary_event_id(event
);
3720 __output_copy(handle
, values
, n
* sizeof(u64
));
3724 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3726 static void perf_output_read_group(struct perf_output_handle
*handle
,
3727 struct perf_event
*event
,
3728 u64 enabled
, u64 running
)
3730 struct perf_event
*leader
= event
->group_leader
, *sub
;
3731 u64 read_format
= event
->attr
.read_format
;
3735 values
[n
++] = 1 + leader
->nr_siblings
;
3737 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3738 values
[n
++] = enabled
;
3740 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3741 values
[n
++] = running
;
3743 if (leader
!= event
)
3744 leader
->pmu
->read(leader
);
3746 values
[n
++] = perf_event_count(leader
);
3747 if (read_format
& PERF_FORMAT_ID
)
3748 values
[n
++] = primary_event_id(leader
);
3750 __output_copy(handle
, values
, n
* sizeof(u64
));
3752 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3756 sub
->pmu
->read(sub
);
3758 values
[n
++] = perf_event_count(sub
);
3759 if (read_format
& PERF_FORMAT_ID
)
3760 values
[n
++] = primary_event_id(sub
);
3762 __output_copy(handle
, values
, n
* sizeof(u64
));
3766 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
3767 PERF_FORMAT_TOTAL_TIME_RUNNING)
3769 static void perf_output_read(struct perf_output_handle
*handle
,
3770 struct perf_event
*event
)
3772 u64 enabled
= 0, running
= 0;
3773 u64 read_format
= event
->attr
.read_format
;
3776 * compute total_time_enabled, total_time_running
3777 * based on snapshot values taken when the event
3778 * was last scheduled in.
3780 * we cannot simply called update_context_time()
3781 * because of locking issue as we are called in
3784 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
3785 calc_timer_values(event
, &enabled
, &running
);
3787 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3788 perf_output_read_group(handle
, event
, enabled
, running
);
3790 perf_output_read_one(handle
, event
, enabled
, running
);
3793 void perf_output_sample(struct perf_output_handle
*handle
,
3794 struct perf_event_header
*header
,
3795 struct perf_sample_data
*data
,
3796 struct perf_event
*event
)
3798 u64 sample_type
= data
->type
;
3800 perf_output_put(handle
, *header
);
3802 if (sample_type
& PERF_SAMPLE_IP
)
3803 perf_output_put(handle
, data
->ip
);
3805 if (sample_type
& PERF_SAMPLE_TID
)
3806 perf_output_put(handle
, data
->tid_entry
);
3808 if (sample_type
& PERF_SAMPLE_TIME
)
3809 perf_output_put(handle
, data
->time
);
3811 if (sample_type
& PERF_SAMPLE_ADDR
)
3812 perf_output_put(handle
, data
->addr
);
3814 if (sample_type
& PERF_SAMPLE_ID
)
3815 perf_output_put(handle
, data
->id
);
3817 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3818 perf_output_put(handle
, data
->stream_id
);
3820 if (sample_type
& PERF_SAMPLE_CPU
)
3821 perf_output_put(handle
, data
->cpu_entry
);
3823 if (sample_type
& PERF_SAMPLE_PERIOD
)
3824 perf_output_put(handle
, data
->period
);
3826 if (sample_type
& PERF_SAMPLE_READ
)
3827 perf_output_read(handle
, event
);
3829 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3830 if (data
->callchain
) {
3833 if (data
->callchain
)
3834 size
+= data
->callchain
->nr
;
3836 size
*= sizeof(u64
);
3838 __output_copy(handle
, data
->callchain
, size
);
3841 perf_output_put(handle
, nr
);
3845 if (sample_type
& PERF_SAMPLE_RAW
) {
3847 perf_output_put(handle
, data
->raw
->size
);
3848 __output_copy(handle
, data
->raw
->data
,
3855 .size
= sizeof(u32
),
3858 perf_output_put(handle
, raw
);
3862 if (!event
->attr
.watermark
) {
3863 int wakeup_events
= event
->attr
.wakeup_events
;
3865 if (wakeup_events
) {
3866 struct ring_buffer
*rb
= handle
->rb
;
3867 int events
= local_inc_return(&rb
->events
);
3869 if (events
>= wakeup_events
) {
3870 local_sub(wakeup_events
, &rb
->events
);
3871 local_inc(&rb
->wakeup
);
3877 void perf_prepare_sample(struct perf_event_header
*header
,
3878 struct perf_sample_data
*data
,
3879 struct perf_event
*event
,
3880 struct pt_regs
*regs
)
3882 u64 sample_type
= event
->attr
.sample_type
;
3884 header
->type
= PERF_RECORD_SAMPLE
;
3885 header
->size
= sizeof(*header
) + event
->header_size
;
3888 header
->misc
|= perf_misc_flags(regs
);
3890 __perf_event_header__init_id(header
, data
, event
);
3892 if (sample_type
& PERF_SAMPLE_IP
)
3893 data
->ip
= perf_instruction_pointer(regs
);
3895 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3898 data
->callchain
= perf_callchain(regs
);
3900 if (data
->callchain
)
3901 size
+= data
->callchain
->nr
;
3903 header
->size
+= size
* sizeof(u64
);
3906 if (sample_type
& PERF_SAMPLE_RAW
) {
3907 int size
= sizeof(u32
);
3910 size
+= data
->raw
->size
;
3912 size
+= sizeof(u32
);
3914 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3915 header
->size
+= size
;
3919 static void perf_event_output(struct perf_event
*event
,
3920 struct perf_sample_data
*data
,
3921 struct pt_regs
*regs
)
3923 struct perf_output_handle handle
;
3924 struct perf_event_header header
;
3926 /* protect the callchain buffers */
3929 perf_prepare_sample(&header
, data
, event
, regs
);
3931 if (perf_output_begin(&handle
, event
, header
.size
))
3934 perf_output_sample(&handle
, &header
, data
, event
);
3936 perf_output_end(&handle
);
3946 struct perf_read_event
{
3947 struct perf_event_header header
;
3954 perf_event_read_event(struct perf_event
*event
,
3955 struct task_struct
*task
)
3957 struct perf_output_handle handle
;
3958 struct perf_sample_data sample
;
3959 struct perf_read_event read_event
= {
3961 .type
= PERF_RECORD_READ
,
3963 .size
= sizeof(read_event
) + event
->read_size
,
3965 .pid
= perf_event_pid(event
, task
),
3966 .tid
= perf_event_tid(event
, task
),
3970 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
3971 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
3975 perf_output_put(&handle
, read_event
);
3976 perf_output_read(&handle
, event
);
3977 perf_event__output_id_sample(event
, &handle
, &sample
);
3979 perf_output_end(&handle
);
3983 * task tracking -- fork/exit
3985 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
3988 struct perf_task_event
{
3989 struct task_struct
*task
;
3990 struct perf_event_context
*task_ctx
;
3993 struct perf_event_header header
;
4003 static void perf_event_task_output(struct perf_event
*event
,
4004 struct perf_task_event
*task_event
)
4006 struct perf_output_handle handle
;
4007 struct perf_sample_data sample
;
4008 struct task_struct
*task
= task_event
->task
;
4009 int ret
, size
= task_event
->event_id
.header
.size
;
4011 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4013 ret
= perf_output_begin(&handle
, event
,
4014 task_event
->event_id
.header
.size
);
4018 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4019 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4021 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4022 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4024 perf_output_put(&handle
, task_event
->event_id
);
4026 perf_event__output_id_sample(event
, &handle
, &sample
);
4028 perf_output_end(&handle
);
4030 task_event
->event_id
.header
.size
= size
;
4033 static int perf_event_task_match(struct perf_event
*event
)
4035 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4038 if (!event_filter_match(event
))
4041 if (event
->attr
.comm
|| event
->attr
.mmap
||
4042 event
->attr
.mmap_data
|| event
->attr
.task
)
4048 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
4049 struct perf_task_event
*task_event
)
4051 struct perf_event
*event
;
4053 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4054 if (perf_event_task_match(event
))
4055 perf_event_task_output(event
, task_event
);
4059 static void perf_event_task_event(struct perf_task_event
*task_event
)
4061 struct perf_cpu_context
*cpuctx
;
4062 struct perf_event_context
*ctx
;
4067 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4068 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4069 if (cpuctx
->active_pmu
!= pmu
)
4071 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
4073 ctx
= task_event
->task_ctx
;
4075 ctxn
= pmu
->task_ctx_nr
;
4078 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4081 perf_event_task_ctx(ctx
, task_event
);
4083 put_cpu_ptr(pmu
->pmu_cpu_context
);
4088 static void perf_event_task(struct task_struct
*task
,
4089 struct perf_event_context
*task_ctx
,
4092 struct perf_task_event task_event
;
4094 if (!atomic_read(&nr_comm_events
) &&
4095 !atomic_read(&nr_mmap_events
) &&
4096 !atomic_read(&nr_task_events
))
4099 task_event
= (struct perf_task_event
){
4101 .task_ctx
= task_ctx
,
4104 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4106 .size
= sizeof(task_event
.event_id
),
4112 .time
= perf_clock(),
4116 perf_event_task_event(&task_event
);
4119 void perf_event_fork(struct task_struct
*task
)
4121 perf_event_task(task
, NULL
, 1);
4128 struct perf_comm_event
{
4129 struct task_struct
*task
;
4134 struct perf_event_header header
;
4141 static void perf_event_comm_output(struct perf_event
*event
,
4142 struct perf_comm_event
*comm_event
)
4144 struct perf_output_handle handle
;
4145 struct perf_sample_data sample
;
4146 int size
= comm_event
->event_id
.header
.size
;
4149 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4150 ret
= perf_output_begin(&handle
, event
,
4151 comm_event
->event_id
.header
.size
);
4156 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4157 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4159 perf_output_put(&handle
, comm_event
->event_id
);
4160 __output_copy(&handle
, comm_event
->comm
,
4161 comm_event
->comm_size
);
4163 perf_event__output_id_sample(event
, &handle
, &sample
);
4165 perf_output_end(&handle
);
4167 comm_event
->event_id
.header
.size
= size
;
4170 static int perf_event_comm_match(struct perf_event
*event
)
4172 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4175 if (!event_filter_match(event
))
4178 if (event
->attr
.comm
)
4184 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4185 struct perf_comm_event
*comm_event
)
4187 struct perf_event
*event
;
4189 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4190 if (perf_event_comm_match(event
))
4191 perf_event_comm_output(event
, comm_event
);
4195 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4197 struct perf_cpu_context
*cpuctx
;
4198 struct perf_event_context
*ctx
;
4199 char comm
[TASK_COMM_LEN
];
4204 memset(comm
, 0, sizeof(comm
));
4205 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4206 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4208 comm_event
->comm
= comm
;
4209 comm_event
->comm_size
= size
;
4211 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4213 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4214 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4215 if (cpuctx
->active_pmu
!= pmu
)
4217 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4219 ctxn
= pmu
->task_ctx_nr
;
4223 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4225 perf_event_comm_ctx(ctx
, comm_event
);
4227 put_cpu_ptr(pmu
->pmu_cpu_context
);
4232 void perf_event_comm(struct task_struct
*task
)
4234 struct perf_comm_event comm_event
;
4235 struct perf_event_context
*ctx
;
4238 for_each_task_context_nr(ctxn
) {
4239 ctx
= task
->perf_event_ctxp
[ctxn
];
4243 perf_event_enable_on_exec(ctx
);
4246 if (!atomic_read(&nr_comm_events
))
4249 comm_event
= (struct perf_comm_event
){
4255 .type
= PERF_RECORD_COMM
,
4264 perf_event_comm_event(&comm_event
);
4271 struct perf_mmap_event
{
4272 struct vm_area_struct
*vma
;
4274 const char *file_name
;
4278 struct perf_event_header header
;
4288 static void perf_event_mmap_output(struct perf_event
*event
,
4289 struct perf_mmap_event
*mmap_event
)
4291 struct perf_output_handle handle
;
4292 struct perf_sample_data sample
;
4293 int size
= mmap_event
->event_id
.header
.size
;
4296 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4297 ret
= perf_output_begin(&handle
, event
,
4298 mmap_event
->event_id
.header
.size
);
4302 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4303 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4305 perf_output_put(&handle
, mmap_event
->event_id
);
4306 __output_copy(&handle
, mmap_event
->file_name
,
4307 mmap_event
->file_size
);
4309 perf_event__output_id_sample(event
, &handle
, &sample
);
4311 perf_output_end(&handle
);
4313 mmap_event
->event_id
.header
.size
= size
;
4316 static int perf_event_mmap_match(struct perf_event
*event
,
4317 struct perf_mmap_event
*mmap_event
,
4320 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4323 if (!event_filter_match(event
))
4326 if ((!executable
&& event
->attr
.mmap_data
) ||
4327 (executable
&& event
->attr
.mmap
))
4333 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4334 struct perf_mmap_event
*mmap_event
,
4337 struct perf_event
*event
;
4339 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4340 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4341 perf_event_mmap_output(event
, mmap_event
);
4345 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4347 struct perf_cpu_context
*cpuctx
;
4348 struct perf_event_context
*ctx
;
4349 struct vm_area_struct
*vma
= mmap_event
->vma
;
4350 struct file
*file
= vma
->vm_file
;
4358 memset(tmp
, 0, sizeof(tmp
));
4362 * d_path works from the end of the rb backwards, so we
4363 * need to add enough zero bytes after the string to handle
4364 * the 64bit alignment we do later.
4366 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4368 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4371 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4373 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4377 if (arch_vma_name(mmap_event
->vma
)) {
4378 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4384 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4386 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4387 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4388 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4390 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4391 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4392 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4396 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4401 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4403 mmap_event
->file_name
= name
;
4404 mmap_event
->file_size
= size
;
4406 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4409 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4410 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4411 if (cpuctx
->active_pmu
!= pmu
)
4413 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4414 vma
->vm_flags
& VM_EXEC
);
4416 ctxn
= pmu
->task_ctx_nr
;
4420 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4422 perf_event_mmap_ctx(ctx
, mmap_event
,
4423 vma
->vm_flags
& VM_EXEC
);
4426 put_cpu_ptr(pmu
->pmu_cpu_context
);
4433 void perf_event_mmap(struct vm_area_struct
*vma
)
4435 struct perf_mmap_event mmap_event
;
4437 if (!atomic_read(&nr_mmap_events
))
4440 mmap_event
= (struct perf_mmap_event
){
4446 .type
= PERF_RECORD_MMAP
,
4447 .misc
= PERF_RECORD_MISC_USER
,
4452 .start
= vma
->vm_start
,
4453 .len
= vma
->vm_end
- vma
->vm_start
,
4454 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4458 perf_event_mmap_event(&mmap_event
);
4462 * IRQ throttle logging
4465 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4467 struct perf_output_handle handle
;
4468 struct perf_sample_data sample
;
4472 struct perf_event_header header
;
4476 } throttle_event
= {
4478 .type
= PERF_RECORD_THROTTLE
,
4480 .size
= sizeof(throttle_event
),
4482 .time
= perf_clock(),
4483 .id
= primary_event_id(event
),
4484 .stream_id
= event
->id
,
4488 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4490 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4492 ret
= perf_output_begin(&handle
, event
,
4493 throttle_event
.header
.size
);
4497 perf_output_put(&handle
, throttle_event
);
4498 perf_event__output_id_sample(event
, &handle
, &sample
);
4499 perf_output_end(&handle
);
4503 * Generic event overflow handling, sampling.
4506 static int __perf_event_overflow(struct perf_event
*event
,
4507 int throttle
, struct perf_sample_data
*data
,
4508 struct pt_regs
*regs
)
4510 int events
= atomic_read(&event
->event_limit
);
4511 struct hw_perf_event
*hwc
= &event
->hw
;
4515 * Non-sampling counters might still use the PMI to fold short
4516 * hardware counters, ignore those.
4518 if (unlikely(!is_sampling_event(event
)))
4521 if (unlikely(hwc
->interrupts
>= max_samples_per_tick
)) {
4523 hwc
->interrupts
= MAX_INTERRUPTS
;
4524 perf_log_throttle(event
, 0);
4530 if (event
->attr
.freq
) {
4531 u64 now
= perf_clock();
4532 s64 delta
= now
- hwc
->freq_time_stamp
;
4534 hwc
->freq_time_stamp
= now
;
4536 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4537 perf_adjust_period(event
, delta
, hwc
->last_period
);
4541 * XXX event_limit might not quite work as expected on inherited
4545 event
->pending_kill
= POLL_IN
;
4546 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4548 event
->pending_kill
= POLL_HUP
;
4549 event
->pending_disable
= 1;
4550 irq_work_queue(&event
->pending
);
4553 if (event
->overflow_handler
)
4554 event
->overflow_handler(event
, data
, regs
);
4556 perf_event_output(event
, data
, regs
);
4558 if (event
->fasync
&& event
->pending_kill
) {
4559 event
->pending_wakeup
= 1;
4560 irq_work_queue(&event
->pending
);
4566 int perf_event_overflow(struct perf_event
*event
,
4567 struct perf_sample_data
*data
,
4568 struct pt_regs
*regs
)
4570 return __perf_event_overflow(event
, 1, data
, regs
);
4574 * Generic software event infrastructure
4577 struct swevent_htable
{
4578 struct swevent_hlist
*swevent_hlist
;
4579 struct mutex hlist_mutex
;
4582 /* Recursion avoidance in each contexts */
4583 int recursion
[PERF_NR_CONTEXTS
];
4586 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
4589 * We directly increment event->count and keep a second value in
4590 * event->hw.period_left to count intervals. This period event
4591 * is kept in the range [-sample_period, 0] so that we can use the
4595 static u64
perf_swevent_set_period(struct perf_event
*event
)
4597 struct hw_perf_event
*hwc
= &event
->hw
;
4598 u64 period
= hwc
->last_period
;
4602 hwc
->last_period
= hwc
->sample_period
;
4605 old
= val
= local64_read(&hwc
->period_left
);
4609 nr
= div64_u64(period
+ val
, period
);
4610 offset
= nr
* period
;
4612 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
4618 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
4619 struct perf_sample_data
*data
,
4620 struct pt_regs
*regs
)
4622 struct hw_perf_event
*hwc
= &event
->hw
;
4626 overflow
= perf_swevent_set_period(event
);
4628 if (hwc
->interrupts
== MAX_INTERRUPTS
)
4631 for (; overflow
; overflow
--) {
4632 if (__perf_event_overflow(event
, throttle
,
4635 * We inhibit the overflow from happening when
4636 * hwc->interrupts == MAX_INTERRUPTS.
4644 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
4645 struct perf_sample_data
*data
,
4646 struct pt_regs
*regs
)
4648 struct hw_perf_event
*hwc
= &event
->hw
;
4650 local64_add(nr
, &event
->count
);
4655 if (!is_sampling_event(event
))
4658 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
4660 return perf_swevent_overflow(event
, 1, data
, regs
);
4662 data
->period
= event
->hw
.last_period
;
4664 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
4665 return perf_swevent_overflow(event
, 1, data
, regs
);
4667 if (local64_add_negative(nr
, &hwc
->period_left
))
4670 perf_swevent_overflow(event
, 0, data
, regs
);
4673 static int perf_exclude_event(struct perf_event
*event
,
4674 struct pt_regs
*regs
)
4676 if (event
->hw
.state
& PERF_HES_STOPPED
)
4680 if (event
->attr
.exclude_user
&& user_mode(regs
))
4683 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4690 static int perf_swevent_match(struct perf_event
*event
,
4691 enum perf_type_id type
,
4693 struct perf_sample_data
*data
,
4694 struct pt_regs
*regs
)
4696 if (event
->attr
.type
!= type
)
4699 if (event
->attr
.config
!= event_id
)
4702 if (perf_exclude_event(event
, regs
))
4708 static inline u64
swevent_hash(u64 type
, u32 event_id
)
4710 u64 val
= event_id
| (type
<< 32);
4712 return hash_64(val
, SWEVENT_HLIST_BITS
);
4715 static inline struct hlist_head
*
4716 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
4718 u64 hash
= swevent_hash(type
, event_id
);
4720 return &hlist
->heads
[hash
];
4723 /* For the read side: events when they trigger */
4724 static inline struct hlist_head
*
4725 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
4727 struct swevent_hlist
*hlist
;
4729 hlist
= rcu_dereference(swhash
->swevent_hlist
);
4733 return __find_swevent_head(hlist
, type
, event_id
);
4736 /* For the event head insertion and removal in the hlist */
4737 static inline struct hlist_head
*
4738 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
4740 struct swevent_hlist
*hlist
;
4741 u32 event_id
= event
->attr
.config
;
4742 u64 type
= event
->attr
.type
;
4745 * Event scheduling is always serialized against hlist allocation
4746 * and release. Which makes the protected version suitable here.
4747 * The context lock guarantees that.
4749 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
4750 lockdep_is_held(&event
->ctx
->lock
));
4754 return __find_swevent_head(hlist
, type
, event_id
);
4757 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4759 struct perf_sample_data
*data
,
4760 struct pt_regs
*regs
)
4762 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4763 struct perf_event
*event
;
4764 struct hlist_node
*node
;
4765 struct hlist_head
*head
;
4768 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
4772 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4773 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4774 perf_swevent_event(event
, nr
, data
, regs
);
4780 int perf_swevent_get_recursion_context(void)
4782 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4784 return get_recursion_context(swhash
->recursion
);
4786 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4788 inline void perf_swevent_put_recursion_context(int rctx
)
4790 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4792 put_recursion_context(swhash
->recursion
, rctx
);
4795 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
4797 struct perf_sample_data data
;
4800 preempt_disable_notrace();
4801 rctx
= perf_swevent_get_recursion_context();
4805 perf_sample_data_init(&data
, addr
);
4807 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
4809 perf_swevent_put_recursion_context(rctx
);
4810 preempt_enable_notrace();
4813 static void perf_swevent_read(struct perf_event
*event
)
4817 static int perf_swevent_add(struct perf_event
*event
, int flags
)
4819 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4820 struct hw_perf_event
*hwc
= &event
->hw
;
4821 struct hlist_head
*head
;
4823 if (is_sampling_event(event
)) {
4824 hwc
->last_period
= hwc
->sample_period
;
4825 perf_swevent_set_period(event
);
4828 hwc
->state
= !(flags
& PERF_EF_START
);
4830 head
= find_swevent_head(swhash
, event
);
4831 if (WARN_ON_ONCE(!head
))
4834 hlist_add_head_rcu(&event
->hlist_entry
, head
);
4839 static void perf_swevent_del(struct perf_event
*event
, int flags
)
4841 hlist_del_rcu(&event
->hlist_entry
);
4844 static void perf_swevent_start(struct perf_event
*event
, int flags
)
4846 event
->hw
.state
= 0;
4849 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
4851 event
->hw
.state
= PERF_HES_STOPPED
;
4854 /* Deref the hlist from the update side */
4855 static inline struct swevent_hlist
*
4856 swevent_hlist_deref(struct swevent_htable
*swhash
)
4858 return rcu_dereference_protected(swhash
->swevent_hlist
,
4859 lockdep_is_held(&swhash
->hlist_mutex
));
4862 static void swevent_hlist_release(struct swevent_htable
*swhash
)
4864 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
4869 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
4870 kfree_rcu(hlist
, rcu_head
);
4873 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
4875 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4877 mutex_lock(&swhash
->hlist_mutex
);
4879 if (!--swhash
->hlist_refcount
)
4880 swevent_hlist_release(swhash
);
4882 mutex_unlock(&swhash
->hlist_mutex
);
4885 static void swevent_hlist_put(struct perf_event
*event
)
4889 if (event
->cpu
!= -1) {
4890 swevent_hlist_put_cpu(event
, event
->cpu
);
4894 for_each_possible_cpu(cpu
)
4895 swevent_hlist_put_cpu(event
, cpu
);
4898 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
4900 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4903 mutex_lock(&swhash
->hlist_mutex
);
4905 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
4906 struct swevent_hlist
*hlist
;
4908 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
4913 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
4915 swhash
->hlist_refcount
++;
4917 mutex_unlock(&swhash
->hlist_mutex
);
4922 static int swevent_hlist_get(struct perf_event
*event
)
4925 int cpu
, failed_cpu
;
4927 if (event
->cpu
!= -1)
4928 return swevent_hlist_get_cpu(event
, event
->cpu
);
4931 for_each_possible_cpu(cpu
) {
4932 err
= swevent_hlist_get_cpu(event
, cpu
);
4942 for_each_possible_cpu(cpu
) {
4943 if (cpu
== failed_cpu
)
4945 swevent_hlist_put_cpu(event
, cpu
);
4952 struct jump_label_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4954 static void sw_perf_event_destroy(struct perf_event
*event
)
4956 u64 event_id
= event
->attr
.config
;
4958 WARN_ON(event
->parent
);
4960 jump_label_dec(&perf_swevent_enabled
[event_id
]);
4961 swevent_hlist_put(event
);
4964 static int perf_swevent_init(struct perf_event
*event
)
4966 int event_id
= event
->attr
.config
;
4968 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
4972 case PERF_COUNT_SW_CPU_CLOCK
:
4973 case PERF_COUNT_SW_TASK_CLOCK
:
4980 if (event_id
>= PERF_COUNT_SW_MAX
)
4983 if (!event
->parent
) {
4986 err
= swevent_hlist_get(event
);
4990 jump_label_inc(&perf_swevent_enabled
[event_id
]);
4991 event
->destroy
= sw_perf_event_destroy
;
4997 static struct pmu perf_swevent
= {
4998 .task_ctx_nr
= perf_sw_context
,
5000 .event_init
= perf_swevent_init
,
5001 .add
= perf_swevent_add
,
5002 .del
= perf_swevent_del
,
5003 .start
= perf_swevent_start
,
5004 .stop
= perf_swevent_stop
,
5005 .read
= perf_swevent_read
,
5008 #ifdef CONFIG_EVENT_TRACING
5010 static int perf_tp_filter_match(struct perf_event
*event
,
5011 struct perf_sample_data
*data
)
5013 void *record
= data
->raw
->data
;
5015 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5020 static int perf_tp_event_match(struct perf_event
*event
,
5021 struct perf_sample_data
*data
,
5022 struct pt_regs
*regs
)
5024 if (event
->hw
.state
& PERF_HES_STOPPED
)
5027 * All tracepoints are from kernel-space.
5029 if (event
->attr
.exclude_kernel
)
5032 if (!perf_tp_filter_match(event
, data
))
5038 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5039 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
5041 struct perf_sample_data data
;
5042 struct perf_event
*event
;
5043 struct hlist_node
*node
;
5045 struct perf_raw_record raw
= {
5050 perf_sample_data_init(&data
, addr
);
5053 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5054 if (perf_tp_event_match(event
, &data
, regs
))
5055 perf_swevent_event(event
, count
, &data
, regs
);
5058 perf_swevent_put_recursion_context(rctx
);
5060 EXPORT_SYMBOL_GPL(perf_tp_event
);
5062 static void tp_perf_event_destroy(struct perf_event
*event
)
5064 perf_trace_destroy(event
);
5067 static int perf_tp_event_init(struct perf_event
*event
)
5071 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5074 err
= perf_trace_init(event
);
5078 event
->destroy
= tp_perf_event_destroy
;
5083 static struct pmu perf_tracepoint
= {
5084 .task_ctx_nr
= perf_sw_context
,
5086 .event_init
= perf_tp_event_init
,
5087 .add
= perf_trace_add
,
5088 .del
= perf_trace_del
,
5089 .start
= perf_swevent_start
,
5090 .stop
= perf_swevent_stop
,
5091 .read
= perf_swevent_read
,
5094 static inline void perf_tp_register(void)
5096 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5099 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5104 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5107 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5108 if (IS_ERR(filter_str
))
5109 return PTR_ERR(filter_str
);
5111 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5117 static void perf_event_free_filter(struct perf_event
*event
)
5119 ftrace_profile_free_filter(event
);
5124 static inline void perf_tp_register(void)
5128 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5133 static void perf_event_free_filter(struct perf_event
*event
)
5137 #endif /* CONFIG_EVENT_TRACING */
5139 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5140 void perf_bp_event(struct perf_event
*bp
, void *data
)
5142 struct perf_sample_data sample
;
5143 struct pt_regs
*regs
= data
;
5145 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
5147 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5148 perf_swevent_event(bp
, 1, &sample
, regs
);
5153 * hrtimer based swevent callback
5156 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5158 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5159 struct perf_sample_data data
;
5160 struct pt_regs
*regs
;
5161 struct perf_event
*event
;
5164 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5166 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5167 return HRTIMER_NORESTART
;
5169 event
->pmu
->read(event
);
5171 perf_sample_data_init(&data
, 0);
5172 data
.period
= event
->hw
.last_period
;
5173 regs
= get_irq_regs();
5175 if (regs
&& !perf_exclude_event(event
, regs
)) {
5176 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
5177 if (perf_event_overflow(event
, &data
, regs
))
5178 ret
= HRTIMER_NORESTART
;
5181 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5182 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5187 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5189 struct hw_perf_event
*hwc
= &event
->hw
;
5192 if (!is_sampling_event(event
))
5195 period
= local64_read(&hwc
->period_left
);
5200 local64_set(&hwc
->period_left
, 0);
5202 period
= max_t(u64
, 10000, hwc
->sample_period
);
5204 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5205 ns_to_ktime(period
), 0,
5206 HRTIMER_MODE_REL_PINNED
, 0);
5209 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5211 struct hw_perf_event
*hwc
= &event
->hw
;
5213 if (is_sampling_event(event
)) {
5214 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5215 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5217 hrtimer_cancel(&hwc
->hrtimer
);
5221 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
5223 struct hw_perf_event
*hwc
= &event
->hw
;
5225 if (!is_sampling_event(event
))
5228 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5229 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5232 * Since hrtimers have a fixed rate, we can do a static freq->period
5233 * mapping and avoid the whole period adjust feedback stuff.
5235 if (event
->attr
.freq
) {
5236 long freq
= event
->attr
.sample_freq
;
5238 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
5239 hwc
->sample_period
= event
->attr
.sample_period
;
5240 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5241 event
->attr
.freq
= 0;
5246 * Software event: cpu wall time clock
5249 static void cpu_clock_event_update(struct perf_event
*event
)
5254 now
= local_clock();
5255 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5256 local64_add(now
- prev
, &event
->count
);
5259 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5261 local64_set(&event
->hw
.prev_count
, local_clock());
5262 perf_swevent_start_hrtimer(event
);
5265 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5267 perf_swevent_cancel_hrtimer(event
);
5268 cpu_clock_event_update(event
);
5271 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5273 if (flags
& PERF_EF_START
)
5274 cpu_clock_event_start(event
, flags
);
5279 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5281 cpu_clock_event_stop(event
, flags
);
5284 static void cpu_clock_event_read(struct perf_event
*event
)
5286 cpu_clock_event_update(event
);
5289 static int cpu_clock_event_init(struct perf_event
*event
)
5291 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5294 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5297 perf_swevent_init_hrtimer(event
);
5302 static struct pmu perf_cpu_clock
= {
5303 .task_ctx_nr
= perf_sw_context
,
5305 .event_init
= cpu_clock_event_init
,
5306 .add
= cpu_clock_event_add
,
5307 .del
= cpu_clock_event_del
,
5308 .start
= cpu_clock_event_start
,
5309 .stop
= cpu_clock_event_stop
,
5310 .read
= cpu_clock_event_read
,
5314 * Software event: task time clock
5317 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5322 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5324 local64_add(delta
, &event
->count
);
5327 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5329 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5330 perf_swevent_start_hrtimer(event
);
5333 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5335 perf_swevent_cancel_hrtimer(event
);
5336 task_clock_event_update(event
, event
->ctx
->time
);
5339 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5341 if (flags
& PERF_EF_START
)
5342 task_clock_event_start(event
, flags
);
5347 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5349 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5352 static void task_clock_event_read(struct perf_event
*event
)
5354 u64 now
= perf_clock();
5355 u64 delta
= now
- event
->ctx
->timestamp
;
5356 u64 time
= event
->ctx
->time
+ delta
;
5358 task_clock_event_update(event
, time
);
5361 static int task_clock_event_init(struct perf_event
*event
)
5363 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5366 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5369 perf_swevent_init_hrtimer(event
);
5374 static struct pmu perf_task_clock
= {
5375 .task_ctx_nr
= perf_sw_context
,
5377 .event_init
= task_clock_event_init
,
5378 .add
= task_clock_event_add
,
5379 .del
= task_clock_event_del
,
5380 .start
= task_clock_event_start
,
5381 .stop
= task_clock_event_stop
,
5382 .read
= task_clock_event_read
,
5385 static void perf_pmu_nop_void(struct pmu
*pmu
)
5389 static int perf_pmu_nop_int(struct pmu
*pmu
)
5394 static void perf_pmu_start_txn(struct pmu
*pmu
)
5396 perf_pmu_disable(pmu
);
5399 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5401 perf_pmu_enable(pmu
);
5405 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5407 perf_pmu_enable(pmu
);
5411 * Ensures all contexts with the same task_ctx_nr have the same
5412 * pmu_cpu_context too.
5414 static void *find_pmu_context(int ctxn
)
5421 list_for_each_entry(pmu
, &pmus
, entry
) {
5422 if (pmu
->task_ctx_nr
== ctxn
)
5423 return pmu
->pmu_cpu_context
;
5429 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5433 for_each_possible_cpu(cpu
) {
5434 struct perf_cpu_context
*cpuctx
;
5436 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5438 if (cpuctx
->active_pmu
== old_pmu
)
5439 cpuctx
->active_pmu
= pmu
;
5443 static void free_pmu_context(struct pmu
*pmu
)
5447 mutex_lock(&pmus_lock
);
5449 * Like a real lame refcount.
5451 list_for_each_entry(i
, &pmus
, entry
) {
5452 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5453 update_pmu_context(i
, pmu
);
5458 free_percpu(pmu
->pmu_cpu_context
);
5460 mutex_unlock(&pmus_lock
);
5462 static struct idr pmu_idr
;
5465 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5467 struct pmu
*pmu
= dev_get_drvdata(dev
);
5469 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5472 static struct device_attribute pmu_dev_attrs
[] = {
5477 static int pmu_bus_running
;
5478 static struct bus_type pmu_bus
= {
5479 .name
= "event_source",
5480 .dev_attrs
= pmu_dev_attrs
,
5483 static void pmu_dev_release(struct device
*dev
)
5488 static int pmu_dev_alloc(struct pmu
*pmu
)
5492 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5496 device_initialize(pmu
->dev
);
5497 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5501 dev_set_drvdata(pmu
->dev
, pmu
);
5502 pmu
->dev
->bus
= &pmu_bus
;
5503 pmu
->dev
->release
= pmu_dev_release
;
5504 ret
= device_add(pmu
->dev
);
5512 put_device(pmu
->dev
);
5516 static struct lock_class_key cpuctx_mutex
;
5517 static struct lock_class_key cpuctx_lock
;
5519 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5523 mutex_lock(&pmus_lock
);
5525 pmu
->pmu_disable_count
= alloc_percpu(int);
5526 if (!pmu
->pmu_disable_count
)
5535 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
5539 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
5547 if (pmu_bus_running
) {
5548 ret
= pmu_dev_alloc(pmu
);
5554 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
5555 if (pmu
->pmu_cpu_context
)
5556 goto got_cpu_context
;
5558 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
5559 if (!pmu
->pmu_cpu_context
)
5562 for_each_possible_cpu(cpu
) {
5563 struct perf_cpu_context
*cpuctx
;
5565 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5566 __perf_event_init_context(&cpuctx
->ctx
);
5567 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
5568 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
5569 cpuctx
->ctx
.type
= cpu_context
;
5570 cpuctx
->ctx
.pmu
= pmu
;
5571 cpuctx
->jiffies_interval
= 1;
5572 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
5573 cpuctx
->active_pmu
= pmu
;
5577 if (!pmu
->start_txn
) {
5578 if (pmu
->pmu_enable
) {
5580 * If we have pmu_enable/pmu_disable calls, install
5581 * transaction stubs that use that to try and batch
5582 * hardware accesses.
5584 pmu
->start_txn
= perf_pmu_start_txn
;
5585 pmu
->commit_txn
= perf_pmu_commit_txn
;
5586 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
5588 pmu
->start_txn
= perf_pmu_nop_void
;
5589 pmu
->commit_txn
= perf_pmu_nop_int
;
5590 pmu
->cancel_txn
= perf_pmu_nop_void
;
5594 if (!pmu
->pmu_enable
) {
5595 pmu
->pmu_enable
= perf_pmu_nop_void
;
5596 pmu
->pmu_disable
= perf_pmu_nop_void
;
5599 list_add_rcu(&pmu
->entry
, &pmus
);
5602 mutex_unlock(&pmus_lock
);
5607 device_del(pmu
->dev
);
5608 put_device(pmu
->dev
);
5611 if (pmu
->type
>= PERF_TYPE_MAX
)
5612 idr_remove(&pmu_idr
, pmu
->type
);
5615 free_percpu(pmu
->pmu_disable_count
);
5619 void perf_pmu_unregister(struct pmu
*pmu
)
5621 mutex_lock(&pmus_lock
);
5622 list_del_rcu(&pmu
->entry
);
5623 mutex_unlock(&pmus_lock
);
5626 * We dereference the pmu list under both SRCU and regular RCU, so
5627 * synchronize against both of those.
5629 synchronize_srcu(&pmus_srcu
);
5632 free_percpu(pmu
->pmu_disable_count
);
5633 if (pmu
->type
>= PERF_TYPE_MAX
)
5634 idr_remove(&pmu_idr
, pmu
->type
);
5635 device_del(pmu
->dev
);
5636 put_device(pmu
->dev
);
5637 free_pmu_context(pmu
);
5640 struct pmu
*perf_init_event(struct perf_event
*event
)
5642 struct pmu
*pmu
= NULL
;
5646 idx
= srcu_read_lock(&pmus_srcu
);
5649 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
5653 ret
= pmu
->event_init(event
);
5659 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5661 ret
= pmu
->event_init(event
);
5665 if (ret
!= -ENOENT
) {
5670 pmu
= ERR_PTR(-ENOENT
);
5672 srcu_read_unlock(&pmus_srcu
, idx
);
5678 * Allocate and initialize a event structure
5680 static struct perf_event
*
5681 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
5682 struct task_struct
*task
,
5683 struct perf_event
*group_leader
,
5684 struct perf_event
*parent_event
,
5685 perf_overflow_handler_t overflow_handler
,
5689 struct perf_event
*event
;
5690 struct hw_perf_event
*hwc
;
5693 if ((unsigned)cpu
>= nr_cpu_ids
) {
5694 if (!task
|| cpu
!= -1)
5695 return ERR_PTR(-EINVAL
);
5698 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
5700 return ERR_PTR(-ENOMEM
);
5703 * Single events are their own group leaders, with an
5704 * empty sibling list:
5707 group_leader
= event
;
5709 mutex_init(&event
->child_mutex
);
5710 INIT_LIST_HEAD(&event
->child_list
);
5712 INIT_LIST_HEAD(&event
->group_entry
);
5713 INIT_LIST_HEAD(&event
->event_entry
);
5714 INIT_LIST_HEAD(&event
->sibling_list
);
5715 INIT_LIST_HEAD(&event
->rb_entry
);
5717 init_waitqueue_head(&event
->waitq
);
5718 init_irq_work(&event
->pending
, perf_pending_event
);
5720 mutex_init(&event
->mmap_mutex
);
5723 event
->attr
= *attr
;
5724 event
->group_leader
= group_leader
;
5728 event
->parent
= parent_event
;
5730 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
5731 event
->id
= atomic64_inc_return(&perf_event_id
);
5733 event
->state
= PERF_EVENT_STATE_INACTIVE
;
5736 event
->attach_state
= PERF_ATTACH_TASK
;
5737 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5739 * hw_breakpoint is a bit difficult here..
5741 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
5742 event
->hw
.bp_target
= task
;
5746 if (!overflow_handler
&& parent_event
) {
5747 overflow_handler
= parent_event
->overflow_handler
;
5748 context
= parent_event
->overflow_handler_context
;
5751 event
->overflow_handler
= overflow_handler
;
5752 event
->overflow_handler_context
= context
;
5755 event
->state
= PERF_EVENT_STATE_OFF
;
5760 hwc
->sample_period
= attr
->sample_period
;
5761 if (attr
->freq
&& attr
->sample_freq
)
5762 hwc
->sample_period
= 1;
5763 hwc
->last_period
= hwc
->sample_period
;
5765 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5768 * we currently do not support PERF_FORMAT_GROUP on inherited events
5770 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
5773 pmu
= perf_init_event(event
);
5779 else if (IS_ERR(pmu
))
5784 put_pid_ns(event
->ns
);
5786 return ERR_PTR(err
);
5789 if (!event
->parent
) {
5790 if (event
->attach_state
& PERF_ATTACH_TASK
)
5791 jump_label_inc(&perf_sched_events
.key
);
5792 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
5793 atomic_inc(&nr_mmap_events
);
5794 if (event
->attr
.comm
)
5795 atomic_inc(&nr_comm_events
);
5796 if (event
->attr
.task
)
5797 atomic_inc(&nr_task_events
);
5798 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5799 err
= get_callchain_buffers();
5802 return ERR_PTR(err
);
5810 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5811 struct perf_event_attr
*attr
)
5816 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
5820 * zero the full structure, so that a short copy will be nice.
5822 memset(attr
, 0, sizeof(*attr
));
5824 ret
= get_user(size
, &uattr
->size
);
5828 if (size
> PAGE_SIZE
) /* silly large */
5831 if (!size
) /* abi compat */
5832 size
= PERF_ATTR_SIZE_VER0
;
5834 if (size
< PERF_ATTR_SIZE_VER0
)
5838 * If we're handed a bigger struct than we know of,
5839 * ensure all the unknown bits are 0 - i.e. new
5840 * user-space does not rely on any kernel feature
5841 * extensions we dont know about yet.
5843 if (size
> sizeof(*attr
)) {
5844 unsigned char __user
*addr
;
5845 unsigned char __user
*end
;
5848 addr
= (void __user
*)uattr
+ sizeof(*attr
);
5849 end
= (void __user
*)uattr
+ size
;
5851 for (; addr
< end
; addr
++) {
5852 ret
= get_user(val
, addr
);
5858 size
= sizeof(*attr
);
5861 ret
= copy_from_user(attr
, uattr
, size
);
5865 if (attr
->__reserved_1
)
5868 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
5871 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
5878 put_user(sizeof(*attr
), &uattr
->size
);
5884 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
5886 struct ring_buffer
*rb
= NULL
, *old_rb
= NULL
;
5892 /* don't allow circular references */
5893 if (event
== output_event
)
5897 * Don't allow cross-cpu buffers
5899 if (output_event
->cpu
!= event
->cpu
)
5903 * If its not a per-cpu rb, it must be the same task.
5905 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
5909 mutex_lock(&event
->mmap_mutex
);
5910 /* Can't redirect output if we've got an active mmap() */
5911 if (atomic_read(&event
->mmap_count
))
5915 /* get the rb we want to redirect to */
5916 rb
= ring_buffer_get(output_event
);
5922 rcu_assign_pointer(event
->rb
, rb
);
5924 ring_buffer_detach(event
, old_rb
);
5927 mutex_unlock(&event
->mmap_mutex
);
5930 ring_buffer_put(old_rb
);
5936 * sys_perf_event_open - open a performance event, associate it to a task/cpu
5938 * @attr_uptr: event_id type attributes for monitoring/sampling
5941 * @group_fd: group leader event fd
5943 SYSCALL_DEFINE5(perf_event_open
,
5944 struct perf_event_attr __user
*, attr_uptr
,
5945 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
5947 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
5948 struct perf_event
*event
, *sibling
;
5949 struct perf_event_attr attr
;
5950 struct perf_event_context
*ctx
;
5951 struct file
*event_file
= NULL
;
5952 struct file
*group_file
= NULL
;
5953 struct task_struct
*task
= NULL
;
5957 int fput_needed
= 0;
5960 /* for future expandability... */
5961 if (flags
& ~PERF_FLAG_ALL
)
5964 err
= perf_copy_attr(attr_uptr
, &attr
);
5968 if (!attr
.exclude_kernel
) {
5969 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
5974 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
5979 * In cgroup mode, the pid argument is used to pass the fd
5980 * opened to the cgroup directory in cgroupfs. The cpu argument
5981 * designates the cpu on which to monitor threads from that
5984 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
5987 event_fd
= get_unused_fd_flags(O_RDWR
);
5991 if (group_fd
!= -1) {
5992 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
5993 if (IS_ERR(group_leader
)) {
5994 err
= PTR_ERR(group_leader
);
5997 group_file
= group_leader
->filp
;
5998 if (flags
& PERF_FLAG_FD_OUTPUT
)
5999 output_event
= group_leader
;
6000 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6001 group_leader
= NULL
;
6004 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6005 task
= find_lively_task_by_vpid(pid
);
6007 err
= PTR_ERR(task
);
6012 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
6014 if (IS_ERR(event
)) {
6015 err
= PTR_ERR(event
);
6019 if (flags
& PERF_FLAG_PID_CGROUP
) {
6020 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6025 * - that has cgroup constraint on event->cpu
6026 * - that may need work on context switch
6028 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
6029 jump_label_inc(&perf_sched_events
.key
);
6033 * Special case software events and allow them to be part of
6034 * any hardware group.
6039 (is_software_event(event
) != is_software_event(group_leader
))) {
6040 if (is_software_event(event
)) {
6042 * If event and group_leader are not both a software
6043 * event, and event is, then group leader is not.
6045 * Allow the addition of software events to !software
6046 * groups, this is safe because software events never
6049 pmu
= group_leader
->pmu
;
6050 } else if (is_software_event(group_leader
) &&
6051 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6053 * In case the group is a pure software group, and we
6054 * try to add a hardware event, move the whole group to
6055 * the hardware context.
6062 * Get the target context (task or percpu):
6064 ctx
= find_get_context(pmu
, task
, cpu
);
6071 put_task_struct(task
);
6076 * Look up the group leader (we will attach this event to it):
6082 * Do not allow a recursive hierarchy (this new sibling
6083 * becoming part of another group-sibling):
6085 if (group_leader
->group_leader
!= group_leader
)
6088 * Do not allow to attach to a group in a different
6089 * task or CPU context:
6092 if (group_leader
->ctx
->type
!= ctx
->type
)
6095 if (group_leader
->ctx
!= ctx
)
6100 * Only a group leader can be exclusive or pinned
6102 if (attr
.exclusive
|| attr
.pinned
)
6107 err
= perf_event_set_output(event
, output_event
);
6112 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6113 if (IS_ERR(event_file
)) {
6114 err
= PTR_ERR(event_file
);
6119 struct perf_event_context
*gctx
= group_leader
->ctx
;
6121 mutex_lock(&gctx
->mutex
);
6122 perf_remove_from_context(group_leader
);
6123 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6125 perf_remove_from_context(sibling
);
6128 mutex_unlock(&gctx
->mutex
);
6132 event
->filp
= event_file
;
6133 WARN_ON_ONCE(ctx
->parent_ctx
);
6134 mutex_lock(&ctx
->mutex
);
6137 perf_install_in_context(ctx
, group_leader
, cpu
);
6139 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6141 perf_install_in_context(ctx
, sibling
, cpu
);
6146 perf_install_in_context(ctx
, event
, cpu
);
6148 perf_unpin_context(ctx
);
6149 mutex_unlock(&ctx
->mutex
);
6151 event
->owner
= current
;
6153 mutex_lock(¤t
->perf_event_mutex
);
6154 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6155 mutex_unlock(¤t
->perf_event_mutex
);
6158 * Precalculate sample_data sizes
6160 perf_event__header_size(event
);
6161 perf_event__id_header_size(event
);
6164 * Drop the reference on the group_event after placing the
6165 * new event on the sibling_list. This ensures destruction
6166 * of the group leader will find the pointer to itself in
6167 * perf_group_detach().
6169 fput_light(group_file
, fput_needed
);
6170 fd_install(event_fd
, event_file
);
6174 perf_unpin_context(ctx
);
6180 put_task_struct(task
);
6182 fput_light(group_file
, fput_needed
);
6184 put_unused_fd(event_fd
);
6189 * perf_event_create_kernel_counter
6191 * @attr: attributes of the counter to create
6192 * @cpu: cpu in which the counter is bound
6193 * @task: task to profile (NULL for percpu)
6196 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6197 struct task_struct
*task
,
6198 perf_overflow_handler_t overflow_handler
,
6201 struct perf_event_context
*ctx
;
6202 struct perf_event
*event
;
6206 * Get the target context (task or percpu):
6209 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
6210 overflow_handler
, context
);
6211 if (IS_ERR(event
)) {
6212 err
= PTR_ERR(event
);
6216 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6223 WARN_ON_ONCE(ctx
->parent_ctx
);
6224 mutex_lock(&ctx
->mutex
);
6225 perf_install_in_context(ctx
, event
, cpu
);
6227 perf_unpin_context(ctx
);
6228 mutex_unlock(&ctx
->mutex
);
6235 return ERR_PTR(err
);
6237 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6239 static void sync_child_event(struct perf_event
*child_event
,
6240 struct task_struct
*child
)
6242 struct perf_event
*parent_event
= child_event
->parent
;
6245 if (child_event
->attr
.inherit_stat
)
6246 perf_event_read_event(child_event
, child
);
6248 child_val
= perf_event_count(child_event
);
6251 * Add back the child's count to the parent's count:
6253 atomic64_add(child_val
, &parent_event
->child_count
);
6254 atomic64_add(child_event
->total_time_enabled
,
6255 &parent_event
->child_total_time_enabled
);
6256 atomic64_add(child_event
->total_time_running
,
6257 &parent_event
->child_total_time_running
);
6260 * Remove this event from the parent's list
6262 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6263 mutex_lock(&parent_event
->child_mutex
);
6264 list_del_init(&child_event
->child_list
);
6265 mutex_unlock(&parent_event
->child_mutex
);
6268 * Release the parent event, if this was the last
6271 fput(parent_event
->filp
);
6275 __perf_event_exit_task(struct perf_event
*child_event
,
6276 struct perf_event_context
*child_ctx
,
6277 struct task_struct
*child
)
6279 if (child_event
->parent
) {
6280 raw_spin_lock_irq(&child_ctx
->lock
);
6281 perf_group_detach(child_event
);
6282 raw_spin_unlock_irq(&child_ctx
->lock
);
6285 perf_remove_from_context(child_event
);
6288 * It can happen that the parent exits first, and has events
6289 * that are still around due to the child reference. These
6290 * events need to be zapped.
6292 if (child_event
->parent
) {
6293 sync_child_event(child_event
, child
);
6294 free_event(child_event
);
6298 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6300 struct perf_event
*child_event
, *tmp
;
6301 struct perf_event_context
*child_ctx
;
6302 unsigned long flags
;
6304 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6305 perf_event_task(child
, NULL
, 0);
6309 local_irq_save(flags
);
6311 * We can't reschedule here because interrupts are disabled,
6312 * and either child is current or it is a task that can't be
6313 * scheduled, so we are now safe from rescheduling changing
6316 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6319 * Take the context lock here so that if find_get_context is
6320 * reading child->perf_event_ctxp, we wait until it has
6321 * incremented the context's refcount before we do put_ctx below.
6323 raw_spin_lock(&child_ctx
->lock
);
6324 task_ctx_sched_out(child_ctx
);
6325 child
->perf_event_ctxp
[ctxn
] = NULL
;
6327 * If this context is a clone; unclone it so it can't get
6328 * swapped to another process while we're removing all
6329 * the events from it.
6331 unclone_ctx(child_ctx
);
6332 update_context_time(child_ctx
);
6333 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6336 * Report the task dead after unscheduling the events so that we
6337 * won't get any samples after PERF_RECORD_EXIT. We can however still
6338 * get a few PERF_RECORD_READ events.
6340 perf_event_task(child
, child_ctx
, 0);
6343 * We can recurse on the same lock type through:
6345 * __perf_event_exit_task()
6346 * sync_child_event()
6347 * fput(parent_event->filp)
6349 * mutex_lock(&ctx->mutex)
6351 * But since its the parent context it won't be the same instance.
6353 mutex_lock(&child_ctx
->mutex
);
6356 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6358 __perf_event_exit_task(child_event
, child_ctx
, child
);
6360 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6362 __perf_event_exit_task(child_event
, child_ctx
, child
);
6365 * If the last event was a group event, it will have appended all
6366 * its siblings to the list, but we obtained 'tmp' before that which
6367 * will still point to the list head terminating the iteration.
6369 if (!list_empty(&child_ctx
->pinned_groups
) ||
6370 !list_empty(&child_ctx
->flexible_groups
))
6373 mutex_unlock(&child_ctx
->mutex
);
6379 * When a child task exits, feed back event values to parent events.
6381 void perf_event_exit_task(struct task_struct
*child
)
6383 struct perf_event
*event
, *tmp
;
6386 mutex_lock(&child
->perf_event_mutex
);
6387 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6389 list_del_init(&event
->owner_entry
);
6392 * Ensure the list deletion is visible before we clear
6393 * the owner, closes a race against perf_release() where
6394 * we need to serialize on the owner->perf_event_mutex.
6397 event
->owner
= NULL
;
6399 mutex_unlock(&child
->perf_event_mutex
);
6401 for_each_task_context_nr(ctxn
)
6402 perf_event_exit_task_context(child
, ctxn
);
6405 static void perf_free_event(struct perf_event
*event
,
6406 struct perf_event_context
*ctx
)
6408 struct perf_event
*parent
= event
->parent
;
6410 if (WARN_ON_ONCE(!parent
))
6413 mutex_lock(&parent
->child_mutex
);
6414 list_del_init(&event
->child_list
);
6415 mutex_unlock(&parent
->child_mutex
);
6419 perf_group_detach(event
);
6420 list_del_event(event
, ctx
);
6425 * free an unexposed, unused context as created by inheritance by
6426 * perf_event_init_task below, used by fork() in case of fail.
6428 void perf_event_free_task(struct task_struct
*task
)
6430 struct perf_event_context
*ctx
;
6431 struct perf_event
*event
, *tmp
;
6434 for_each_task_context_nr(ctxn
) {
6435 ctx
= task
->perf_event_ctxp
[ctxn
];
6439 mutex_lock(&ctx
->mutex
);
6441 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6443 perf_free_event(event
, ctx
);
6445 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6447 perf_free_event(event
, ctx
);
6449 if (!list_empty(&ctx
->pinned_groups
) ||
6450 !list_empty(&ctx
->flexible_groups
))
6453 mutex_unlock(&ctx
->mutex
);
6459 void perf_event_delayed_put(struct task_struct
*task
)
6463 for_each_task_context_nr(ctxn
)
6464 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6468 * inherit a event from parent task to child task:
6470 static struct perf_event
*
6471 inherit_event(struct perf_event
*parent_event
,
6472 struct task_struct
*parent
,
6473 struct perf_event_context
*parent_ctx
,
6474 struct task_struct
*child
,
6475 struct perf_event
*group_leader
,
6476 struct perf_event_context
*child_ctx
)
6478 struct perf_event
*child_event
;
6479 unsigned long flags
;
6482 * Instead of creating recursive hierarchies of events,
6483 * we link inherited events back to the original parent,
6484 * which has a filp for sure, which we use as the reference
6487 if (parent_event
->parent
)
6488 parent_event
= parent_event
->parent
;
6490 child_event
= perf_event_alloc(&parent_event
->attr
,
6493 group_leader
, parent_event
,
6495 if (IS_ERR(child_event
))
6500 * Make the child state follow the state of the parent event,
6501 * not its attr.disabled bit. We hold the parent's mutex,
6502 * so we won't race with perf_event_{en, dis}able_family.
6504 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6505 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6507 child_event
->state
= PERF_EVENT_STATE_OFF
;
6509 if (parent_event
->attr
.freq
) {
6510 u64 sample_period
= parent_event
->hw
.sample_period
;
6511 struct hw_perf_event
*hwc
= &child_event
->hw
;
6513 hwc
->sample_period
= sample_period
;
6514 hwc
->last_period
= sample_period
;
6516 local64_set(&hwc
->period_left
, sample_period
);
6519 child_event
->ctx
= child_ctx
;
6520 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6521 child_event
->overflow_handler_context
6522 = parent_event
->overflow_handler_context
;
6525 * Precalculate sample_data sizes
6527 perf_event__header_size(child_event
);
6528 perf_event__id_header_size(child_event
);
6531 * Link it up in the child's context:
6533 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6534 add_event_to_ctx(child_event
, child_ctx
);
6535 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6538 * Get a reference to the parent filp - we will fput it
6539 * when the child event exits. This is safe to do because
6540 * we are in the parent and we know that the filp still
6541 * exists and has a nonzero count:
6543 atomic_long_inc(&parent_event
->filp
->f_count
);
6546 * Link this into the parent event's child list
6548 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6549 mutex_lock(&parent_event
->child_mutex
);
6550 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
6551 mutex_unlock(&parent_event
->child_mutex
);
6556 static int inherit_group(struct perf_event
*parent_event
,
6557 struct task_struct
*parent
,
6558 struct perf_event_context
*parent_ctx
,
6559 struct task_struct
*child
,
6560 struct perf_event_context
*child_ctx
)
6562 struct perf_event
*leader
;
6563 struct perf_event
*sub
;
6564 struct perf_event
*child_ctr
;
6566 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
6567 child
, NULL
, child_ctx
);
6569 return PTR_ERR(leader
);
6570 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
6571 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
6572 child
, leader
, child_ctx
);
6573 if (IS_ERR(child_ctr
))
6574 return PTR_ERR(child_ctr
);
6580 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
6581 struct perf_event_context
*parent_ctx
,
6582 struct task_struct
*child
, int ctxn
,
6586 struct perf_event_context
*child_ctx
;
6588 if (!event
->attr
.inherit
) {
6593 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6596 * This is executed from the parent task context, so
6597 * inherit events that have been marked for cloning.
6598 * First allocate and initialize a context for the
6602 child_ctx
= alloc_perf_context(event
->pmu
, child
);
6606 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
6609 ret
= inherit_group(event
, parent
, parent_ctx
,
6619 * Initialize the perf_event context in task_struct
6621 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
6623 struct perf_event_context
*child_ctx
, *parent_ctx
;
6624 struct perf_event_context
*cloned_ctx
;
6625 struct perf_event
*event
;
6626 struct task_struct
*parent
= current
;
6627 int inherited_all
= 1;
6628 unsigned long flags
;
6631 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
6635 * If the parent's context is a clone, pin it so it won't get
6638 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
6641 * No need to check if parent_ctx != NULL here; since we saw
6642 * it non-NULL earlier, the only reason for it to become NULL
6643 * is if we exit, and since we're currently in the middle of
6644 * a fork we can't be exiting at the same time.
6648 * Lock the parent list. No need to lock the child - not PID
6649 * hashed yet and not running, so nobody can access it.
6651 mutex_lock(&parent_ctx
->mutex
);
6654 * We dont have to disable NMIs - we are only looking at
6655 * the list, not manipulating it:
6657 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
6658 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6659 child
, ctxn
, &inherited_all
);
6665 * We can't hold ctx->lock when iterating the ->flexible_group list due
6666 * to allocations, but we need to prevent rotation because
6667 * rotate_ctx() will change the list from interrupt context.
6669 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6670 parent_ctx
->rotate_disable
= 1;
6671 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6673 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
6674 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6675 child
, ctxn
, &inherited_all
);
6680 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6681 parent_ctx
->rotate_disable
= 0;
6683 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6685 if (child_ctx
&& inherited_all
) {
6687 * Mark the child context as a clone of the parent
6688 * context, or of whatever the parent is a clone of.
6690 * Note that if the parent is a clone, the holding of
6691 * parent_ctx->lock avoids it from being uncloned.
6693 cloned_ctx
= parent_ctx
->parent_ctx
;
6695 child_ctx
->parent_ctx
= cloned_ctx
;
6696 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
6698 child_ctx
->parent_ctx
= parent_ctx
;
6699 child_ctx
->parent_gen
= parent_ctx
->generation
;
6701 get_ctx(child_ctx
->parent_ctx
);
6704 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6705 mutex_unlock(&parent_ctx
->mutex
);
6707 perf_unpin_context(parent_ctx
);
6708 put_ctx(parent_ctx
);
6714 * Initialize the perf_event context in task_struct
6716 int perf_event_init_task(struct task_struct
*child
)
6720 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
6721 mutex_init(&child
->perf_event_mutex
);
6722 INIT_LIST_HEAD(&child
->perf_event_list
);
6724 for_each_task_context_nr(ctxn
) {
6725 ret
= perf_event_init_context(child
, ctxn
);
6733 static void __init
perf_event_init_all_cpus(void)
6735 struct swevent_htable
*swhash
;
6738 for_each_possible_cpu(cpu
) {
6739 swhash
= &per_cpu(swevent_htable
, cpu
);
6740 mutex_init(&swhash
->hlist_mutex
);
6741 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
6745 static void __cpuinit
perf_event_init_cpu(int cpu
)
6747 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6749 mutex_lock(&swhash
->hlist_mutex
);
6750 if (swhash
->hlist_refcount
> 0) {
6751 struct swevent_hlist
*hlist
;
6753 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
6755 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6757 mutex_unlock(&swhash
->hlist_mutex
);
6760 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
6761 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
6763 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6765 WARN_ON(!irqs_disabled());
6767 list_del_init(&cpuctx
->rotation_list
);
6770 static void __perf_event_exit_context(void *__info
)
6772 struct perf_event_context
*ctx
= __info
;
6773 struct perf_event
*event
, *tmp
;
6775 perf_pmu_rotate_stop(ctx
->pmu
);
6777 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
6778 __perf_remove_from_context(event
);
6779 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
6780 __perf_remove_from_context(event
);
6783 static void perf_event_exit_cpu_context(int cpu
)
6785 struct perf_event_context
*ctx
;
6789 idx
= srcu_read_lock(&pmus_srcu
);
6790 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6791 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
6793 mutex_lock(&ctx
->mutex
);
6794 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
6795 mutex_unlock(&ctx
->mutex
);
6797 srcu_read_unlock(&pmus_srcu
, idx
);
6800 static void perf_event_exit_cpu(int cpu
)
6802 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6804 mutex_lock(&swhash
->hlist_mutex
);
6805 swevent_hlist_release(swhash
);
6806 mutex_unlock(&swhash
->hlist_mutex
);
6808 perf_event_exit_cpu_context(cpu
);
6811 static inline void perf_event_exit_cpu(int cpu
) { }
6815 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
6819 for_each_online_cpu(cpu
)
6820 perf_event_exit_cpu(cpu
);
6826 * Run the perf reboot notifier at the very last possible moment so that
6827 * the generic watchdog code runs as long as possible.
6829 static struct notifier_block perf_reboot_notifier
= {
6830 .notifier_call
= perf_reboot
,
6831 .priority
= INT_MIN
,
6834 static int __cpuinit
6835 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
6837 unsigned int cpu
= (long)hcpu
;
6839 switch (action
& ~CPU_TASKS_FROZEN
) {
6841 case CPU_UP_PREPARE
:
6842 case CPU_DOWN_FAILED
:
6843 perf_event_init_cpu(cpu
);
6846 case CPU_UP_CANCELED
:
6847 case CPU_DOWN_PREPARE
:
6848 perf_event_exit_cpu(cpu
);
6858 void __init
perf_event_init(void)
6864 perf_event_init_all_cpus();
6865 init_srcu_struct(&pmus_srcu
);
6866 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
6867 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
6868 perf_pmu_register(&perf_task_clock
, NULL
, -1);
6870 perf_cpu_notifier(perf_cpu_notify
);
6871 register_reboot_notifier(&perf_reboot_notifier
);
6873 ret
= init_hw_breakpoint();
6874 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
6876 /* do not patch jump label more than once per second */
6877 jump_label_rate_limit(&perf_sched_events
, HZ
);
6880 static int __init
perf_event_sysfs_init(void)
6885 mutex_lock(&pmus_lock
);
6887 ret
= bus_register(&pmu_bus
);
6891 list_for_each_entry(pmu
, &pmus
, entry
) {
6892 if (!pmu
->name
|| pmu
->type
< 0)
6895 ret
= pmu_dev_alloc(pmu
);
6896 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
6898 pmu_bus_running
= 1;
6902 mutex_unlock(&pmus_lock
);
6906 device_initcall(perf_event_sysfs_init
);
6908 #ifdef CONFIG_CGROUP_PERF
6909 static struct cgroup_subsys_state
*perf_cgroup_create(
6910 struct cgroup_subsys
*ss
, struct cgroup
*cont
)
6912 struct perf_cgroup
*jc
;
6914 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
6916 return ERR_PTR(-ENOMEM
);
6918 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
6921 return ERR_PTR(-ENOMEM
);
6927 static void perf_cgroup_destroy(struct cgroup_subsys
*ss
,
6928 struct cgroup
*cont
)
6930 struct perf_cgroup
*jc
;
6931 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
6932 struct perf_cgroup
, css
);
6933 free_percpu(jc
->info
);
6937 static int __perf_cgroup_move(void *info
)
6939 struct task_struct
*task
= info
;
6940 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
6944 static void perf_cgroup_attach(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
6945 struct cgroup_taskset
*tset
)
6947 struct task_struct
*task
;
6949 cgroup_taskset_for_each(task
, cgrp
, tset
)
6950 task_function_call(task
, __perf_cgroup_move
, task
);
6953 static void perf_cgroup_exit(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
6954 struct cgroup
*old_cgrp
, struct task_struct
*task
)
6957 * cgroup_exit() is called in the copy_process() failure path.
6958 * Ignore this case since the task hasn't ran yet, this avoids
6959 * trying to poke a half freed task state from generic code.
6961 if (!(task
->flags
& PF_EXITING
))
6964 task_function_call(task
, __perf_cgroup_move
, task
);
6967 struct cgroup_subsys perf_subsys
= {
6968 .name
= "perf_event",
6969 .subsys_id
= perf_subsys_id
,
6970 .create
= perf_cgroup_create
,
6971 .destroy
= perf_cgroup_destroy
,
6972 .exit
= perf_cgroup_exit
,
6973 .attach
= perf_cgroup_attach
,
6975 #endif /* CONFIG_CGROUP_PERF */