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_cgroup_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 static int perf_event_index(struct perf_event
*event
)
3213 if (event
->hw
.state
& PERF_HES_STOPPED
)
3216 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3219 return event
->pmu
->event_idx(event
);
3222 static void calc_timer_values(struct perf_event
*event
,
3229 *now
= perf_clock();
3230 ctx_time
= event
->shadow_ctx_time
+ *now
;
3231 *enabled
= ctx_time
- event
->tstamp_enabled
;
3232 *running
= ctx_time
- event
->tstamp_running
;
3235 void __weak
perf_update_user_clock(struct perf_event_mmap_page
*userpg
, u64 now
)
3240 * Callers need to ensure there can be no nesting of this function, otherwise
3241 * the seqlock logic goes bad. We can not serialize this because the arch
3242 * code calls this from NMI context.
3244 void perf_event_update_userpage(struct perf_event
*event
)
3246 struct perf_event_mmap_page
*userpg
;
3247 struct ring_buffer
*rb
;
3248 u64 enabled
, running
, now
;
3252 * compute total_time_enabled, total_time_running
3253 * based on snapshot values taken when the event
3254 * was last scheduled in.
3256 * we cannot simply called update_context_time()
3257 * because of locking issue as we can be called in
3260 calc_timer_values(event
, &now
, &enabled
, &running
);
3261 rb
= rcu_dereference(event
->rb
);
3265 userpg
= rb
->user_page
;
3268 * Disable preemption so as to not let the corresponding user-space
3269 * spin too long if we get preempted.
3274 userpg
->index
= perf_event_index(event
);
3275 userpg
->offset
= perf_event_count(event
);
3277 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3279 userpg
->time_enabled
= enabled
+
3280 atomic64_read(&event
->child_total_time_enabled
);
3282 userpg
->time_running
= running
+
3283 atomic64_read(&event
->child_total_time_running
);
3285 perf_update_user_clock(userpg
, now
);
3294 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3296 struct perf_event
*event
= vma
->vm_file
->private_data
;
3297 struct ring_buffer
*rb
;
3298 int ret
= VM_FAULT_SIGBUS
;
3300 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3301 if (vmf
->pgoff
== 0)
3307 rb
= rcu_dereference(event
->rb
);
3311 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3314 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3318 get_page(vmf
->page
);
3319 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3320 vmf
->page
->index
= vmf
->pgoff
;
3329 static void ring_buffer_attach(struct perf_event
*event
,
3330 struct ring_buffer
*rb
)
3332 unsigned long flags
;
3334 if (!list_empty(&event
->rb_entry
))
3337 spin_lock_irqsave(&rb
->event_lock
, flags
);
3338 if (!list_empty(&event
->rb_entry
))
3341 list_add(&event
->rb_entry
, &rb
->event_list
);
3343 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3346 static void ring_buffer_detach(struct perf_event
*event
,
3347 struct ring_buffer
*rb
)
3349 unsigned long flags
;
3351 if (list_empty(&event
->rb_entry
))
3354 spin_lock_irqsave(&rb
->event_lock
, flags
);
3355 list_del_init(&event
->rb_entry
);
3356 wake_up_all(&event
->waitq
);
3357 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3360 static void ring_buffer_wakeup(struct perf_event
*event
)
3362 struct ring_buffer
*rb
;
3365 rb
= rcu_dereference(event
->rb
);
3369 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
3370 wake_up_all(&event
->waitq
);
3376 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3378 struct ring_buffer
*rb
;
3380 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3384 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3386 struct ring_buffer
*rb
;
3389 rb
= rcu_dereference(event
->rb
);
3391 if (!atomic_inc_not_zero(&rb
->refcount
))
3399 static void ring_buffer_put(struct ring_buffer
*rb
)
3401 struct perf_event
*event
, *n
;
3402 unsigned long flags
;
3404 if (!atomic_dec_and_test(&rb
->refcount
))
3407 spin_lock_irqsave(&rb
->event_lock
, flags
);
3408 list_for_each_entry_safe(event
, n
, &rb
->event_list
, rb_entry
) {
3409 list_del_init(&event
->rb_entry
);
3410 wake_up_all(&event
->waitq
);
3412 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3414 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3417 static void perf_mmap_open(struct vm_area_struct
*vma
)
3419 struct perf_event
*event
= vma
->vm_file
->private_data
;
3421 atomic_inc(&event
->mmap_count
);
3424 static void perf_mmap_close(struct vm_area_struct
*vma
)
3426 struct perf_event
*event
= vma
->vm_file
->private_data
;
3428 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3429 unsigned long size
= perf_data_size(event
->rb
);
3430 struct user_struct
*user
= event
->mmap_user
;
3431 struct ring_buffer
*rb
= event
->rb
;
3433 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3434 vma
->vm_mm
->pinned_vm
-= event
->mmap_locked
;
3435 rcu_assign_pointer(event
->rb
, NULL
);
3436 ring_buffer_detach(event
, rb
);
3437 mutex_unlock(&event
->mmap_mutex
);
3439 ring_buffer_put(rb
);
3444 static const struct vm_operations_struct perf_mmap_vmops
= {
3445 .open
= perf_mmap_open
,
3446 .close
= perf_mmap_close
,
3447 .fault
= perf_mmap_fault
,
3448 .page_mkwrite
= perf_mmap_fault
,
3451 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3453 struct perf_event
*event
= file
->private_data
;
3454 unsigned long user_locked
, user_lock_limit
;
3455 struct user_struct
*user
= current_user();
3456 unsigned long locked
, lock_limit
;
3457 struct ring_buffer
*rb
;
3458 unsigned long vma_size
;
3459 unsigned long nr_pages
;
3460 long user_extra
, extra
;
3461 int ret
= 0, flags
= 0;
3464 * Don't allow mmap() of inherited per-task counters. This would
3465 * create a performance issue due to all children writing to the
3468 if (event
->cpu
== -1 && event
->attr
.inherit
)
3471 if (!(vma
->vm_flags
& VM_SHARED
))
3474 vma_size
= vma
->vm_end
- vma
->vm_start
;
3475 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3478 * If we have rb pages ensure they're a power-of-two number, so we
3479 * can do bitmasks instead of modulo.
3481 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3484 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3487 if (vma
->vm_pgoff
!= 0)
3490 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3491 mutex_lock(&event
->mmap_mutex
);
3493 if (event
->rb
->nr_pages
== nr_pages
)
3494 atomic_inc(&event
->rb
->refcount
);
3500 user_extra
= nr_pages
+ 1;
3501 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3504 * Increase the limit linearly with more CPUs:
3506 user_lock_limit
*= num_online_cpus();
3508 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3511 if (user_locked
> user_lock_limit
)
3512 extra
= user_locked
- user_lock_limit
;
3514 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3515 lock_limit
>>= PAGE_SHIFT
;
3516 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
3518 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3519 !capable(CAP_IPC_LOCK
)) {
3526 if (vma
->vm_flags
& VM_WRITE
)
3527 flags
|= RING_BUFFER_WRITABLE
;
3529 rb
= rb_alloc(nr_pages
,
3530 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
3537 rcu_assign_pointer(event
->rb
, rb
);
3539 atomic_long_add(user_extra
, &user
->locked_vm
);
3540 event
->mmap_locked
= extra
;
3541 event
->mmap_user
= get_current_user();
3542 vma
->vm_mm
->pinned_vm
+= event
->mmap_locked
;
3544 perf_event_update_userpage(event
);
3548 atomic_inc(&event
->mmap_count
);
3549 mutex_unlock(&event
->mmap_mutex
);
3551 vma
->vm_flags
|= VM_RESERVED
;
3552 vma
->vm_ops
= &perf_mmap_vmops
;
3557 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3559 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3560 struct perf_event
*event
= filp
->private_data
;
3563 mutex_lock(&inode
->i_mutex
);
3564 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3565 mutex_unlock(&inode
->i_mutex
);
3573 static const struct file_operations perf_fops
= {
3574 .llseek
= no_llseek
,
3575 .release
= perf_release
,
3578 .unlocked_ioctl
= perf_ioctl
,
3579 .compat_ioctl
= perf_ioctl
,
3581 .fasync
= perf_fasync
,
3587 * If there's data, ensure we set the poll() state and publish everything
3588 * to user-space before waking everybody up.
3591 void perf_event_wakeup(struct perf_event
*event
)
3593 ring_buffer_wakeup(event
);
3595 if (event
->pending_kill
) {
3596 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3597 event
->pending_kill
= 0;
3601 static void perf_pending_event(struct irq_work
*entry
)
3603 struct perf_event
*event
= container_of(entry
,
3604 struct perf_event
, pending
);
3606 if (event
->pending_disable
) {
3607 event
->pending_disable
= 0;
3608 __perf_event_disable(event
);
3611 if (event
->pending_wakeup
) {
3612 event
->pending_wakeup
= 0;
3613 perf_event_wakeup(event
);
3618 * We assume there is only KVM supporting the callbacks.
3619 * Later on, we might change it to a list if there is
3620 * another virtualization implementation supporting the callbacks.
3622 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3624 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3626 perf_guest_cbs
= cbs
;
3629 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3631 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3633 perf_guest_cbs
= NULL
;
3636 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3638 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3639 struct perf_sample_data
*data
,
3640 struct perf_event
*event
)
3642 u64 sample_type
= event
->attr
.sample_type
;
3644 data
->type
= sample_type
;
3645 header
->size
+= event
->id_header_size
;
3647 if (sample_type
& PERF_SAMPLE_TID
) {
3648 /* namespace issues */
3649 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3650 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3653 if (sample_type
& PERF_SAMPLE_TIME
)
3654 data
->time
= perf_clock();
3656 if (sample_type
& PERF_SAMPLE_ID
)
3657 data
->id
= primary_event_id(event
);
3659 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3660 data
->stream_id
= event
->id
;
3662 if (sample_type
& PERF_SAMPLE_CPU
) {
3663 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3664 data
->cpu_entry
.reserved
= 0;
3668 void perf_event_header__init_id(struct perf_event_header
*header
,
3669 struct perf_sample_data
*data
,
3670 struct perf_event
*event
)
3672 if (event
->attr
.sample_id_all
)
3673 __perf_event_header__init_id(header
, data
, event
);
3676 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
3677 struct perf_sample_data
*data
)
3679 u64 sample_type
= data
->type
;
3681 if (sample_type
& PERF_SAMPLE_TID
)
3682 perf_output_put(handle
, data
->tid_entry
);
3684 if (sample_type
& PERF_SAMPLE_TIME
)
3685 perf_output_put(handle
, data
->time
);
3687 if (sample_type
& PERF_SAMPLE_ID
)
3688 perf_output_put(handle
, data
->id
);
3690 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3691 perf_output_put(handle
, data
->stream_id
);
3693 if (sample_type
& PERF_SAMPLE_CPU
)
3694 perf_output_put(handle
, data
->cpu_entry
);
3697 void perf_event__output_id_sample(struct perf_event
*event
,
3698 struct perf_output_handle
*handle
,
3699 struct perf_sample_data
*sample
)
3701 if (event
->attr
.sample_id_all
)
3702 __perf_event__output_id_sample(handle
, sample
);
3705 static void perf_output_read_one(struct perf_output_handle
*handle
,
3706 struct perf_event
*event
,
3707 u64 enabled
, u64 running
)
3709 u64 read_format
= event
->attr
.read_format
;
3713 values
[n
++] = perf_event_count(event
);
3714 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3715 values
[n
++] = enabled
+
3716 atomic64_read(&event
->child_total_time_enabled
);
3718 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3719 values
[n
++] = running
+
3720 atomic64_read(&event
->child_total_time_running
);
3722 if (read_format
& PERF_FORMAT_ID
)
3723 values
[n
++] = primary_event_id(event
);
3725 __output_copy(handle
, values
, n
* sizeof(u64
));
3729 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3731 static void perf_output_read_group(struct perf_output_handle
*handle
,
3732 struct perf_event
*event
,
3733 u64 enabled
, u64 running
)
3735 struct perf_event
*leader
= event
->group_leader
, *sub
;
3736 u64 read_format
= event
->attr
.read_format
;
3740 values
[n
++] = 1 + leader
->nr_siblings
;
3742 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3743 values
[n
++] = enabled
;
3745 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3746 values
[n
++] = running
;
3748 if (leader
!= event
)
3749 leader
->pmu
->read(leader
);
3751 values
[n
++] = perf_event_count(leader
);
3752 if (read_format
& PERF_FORMAT_ID
)
3753 values
[n
++] = primary_event_id(leader
);
3755 __output_copy(handle
, values
, n
* sizeof(u64
));
3757 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3761 sub
->pmu
->read(sub
);
3763 values
[n
++] = perf_event_count(sub
);
3764 if (read_format
& PERF_FORMAT_ID
)
3765 values
[n
++] = primary_event_id(sub
);
3767 __output_copy(handle
, values
, n
* sizeof(u64
));
3771 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
3772 PERF_FORMAT_TOTAL_TIME_RUNNING)
3774 static void perf_output_read(struct perf_output_handle
*handle
,
3775 struct perf_event
*event
)
3777 u64 enabled
= 0, running
= 0, now
;
3778 u64 read_format
= event
->attr
.read_format
;
3781 * compute total_time_enabled, total_time_running
3782 * based on snapshot values taken when the event
3783 * was last scheduled in.
3785 * we cannot simply called update_context_time()
3786 * because of locking issue as we are called in
3789 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
3790 calc_timer_values(event
, &now
, &enabled
, &running
);
3792 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3793 perf_output_read_group(handle
, event
, enabled
, running
);
3795 perf_output_read_one(handle
, event
, enabled
, running
);
3798 void perf_output_sample(struct perf_output_handle
*handle
,
3799 struct perf_event_header
*header
,
3800 struct perf_sample_data
*data
,
3801 struct perf_event
*event
)
3803 u64 sample_type
= data
->type
;
3805 perf_output_put(handle
, *header
);
3807 if (sample_type
& PERF_SAMPLE_IP
)
3808 perf_output_put(handle
, data
->ip
);
3810 if (sample_type
& PERF_SAMPLE_TID
)
3811 perf_output_put(handle
, data
->tid_entry
);
3813 if (sample_type
& PERF_SAMPLE_TIME
)
3814 perf_output_put(handle
, data
->time
);
3816 if (sample_type
& PERF_SAMPLE_ADDR
)
3817 perf_output_put(handle
, data
->addr
);
3819 if (sample_type
& PERF_SAMPLE_ID
)
3820 perf_output_put(handle
, data
->id
);
3822 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3823 perf_output_put(handle
, data
->stream_id
);
3825 if (sample_type
& PERF_SAMPLE_CPU
)
3826 perf_output_put(handle
, data
->cpu_entry
);
3828 if (sample_type
& PERF_SAMPLE_PERIOD
)
3829 perf_output_put(handle
, data
->period
);
3831 if (sample_type
& PERF_SAMPLE_READ
)
3832 perf_output_read(handle
, event
);
3834 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3835 if (data
->callchain
) {
3838 if (data
->callchain
)
3839 size
+= data
->callchain
->nr
;
3841 size
*= sizeof(u64
);
3843 __output_copy(handle
, data
->callchain
, size
);
3846 perf_output_put(handle
, nr
);
3850 if (sample_type
& PERF_SAMPLE_RAW
) {
3852 perf_output_put(handle
, data
->raw
->size
);
3853 __output_copy(handle
, data
->raw
->data
,
3860 .size
= sizeof(u32
),
3863 perf_output_put(handle
, raw
);
3867 if (!event
->attr
.watermark
) {
3868 int wakeup_events
= event
->attr
.wakeup_events
;
3870 if (wakeup_events
) {
3871 struct ring_buffer
*rb
= handle
->rb
;
3872 int events
= local_inc_return(&rb
->events
);
3874 if (events
>= wakeup_events
) {
3875 local_sub(wakeup_events
, &rb
->events
);
3876 local_inc(&rb
->wakeup
);
3882 void perf_prepare_sample(struct perf_event_header
*header
,
3883 struct perf_sample_data
*data
,
3884 struct perf_event
*event
,
3885 struct pt_regs
*regs
)
3887 u64 sample_type
= event
->attr
.sample_type
;
3889 header
->type
= PERF_RECORD_SAMPLE
;
3890 header
->size
= sizeof(*header
) + event
->header_size
;
3893 header
->misc
|= perf_misc_flags(regs
);
3895 __perf_event_header__init_id(header
, data
, event
);
3897 if (sample_type
& PERF_SAMPLE_IP
)
3898 data
->ip
= perf_instruction_pointer(regs
);
3900 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3903 data
->callchain
= perf_callchain(regs
);
3905 if (data
->callchain
)
3906 size
+= data
->callchain
->nr
;
3908 header
->size
+= size
* sizeof(u64
);
3911 if (sample_type
& PERF_SAMPLE_RAW
) {
3912 int size
= sizeof(u32
);
3915 size
+= data
->raw
->size
;
3917 size
+= sizeof(u32
);
3919 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3920 header
->size
+= size
;
3924 static void perf_event_output(struct perf_event
*event
,
3925 struct perf_sample_data
*data
,
3926 struct pt_regs
*regs
)
3928 struct perf_output_handle handle
;
3929 struct perf_event_header header
;
3931 /* protect the callchain buffers */
3934 perf_prepare_sample(&header
, data
, event
, regs
);
3936 if (perf_output_begin(&handle
, event
, header
.size
))
3939 perf_output_sample(&handle
, &header
, data
, event
);
3941 perf_output_end(&handle
);
3951 struct perf_read_event
{
3952 struct perf_event_header header
;
3959 perf_event_read_event(struct perf_event
*event
,
3960 struct task_struct
*task
)
3962 struct perf_output_handle handle
;
3963 struct perf_sample_data sample
;
3964 struct perf_read_event read_event
= {
3966 .type
= PERF_RECORD_READ
,
3968 .size
= sizeof(read_event
) + event
->read_size
,
3970 .pid
= perf_event_pid(event
, task
),
3971 .tid
= perf_event_tid(event
, task
),
3975 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
3976 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
3980 perf_output_put(&handle
, read_event
);
3981 perf_output_read(&handle
, event
);
3982 perf_event__output_id_sample(event
, &handle
, &sample
);
3984 perf_output_end(&handle
);
3988 * task tracking -- fork/exit
3990 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
3993 struct perf_task_event
{
3994 struct task_struct
*task
;
3995 struct perf_event_context
*task_ctx
;
3998 struct perf_event_header header
;
4008 static void perf_event_task_output(struct perf_event
*event
,
4009 struct perf_task_event
*task_event
)
4011 struct perf_output_handle handle
;
4012 struct perf_sample_data sample
;
4013 struct task_struct
*task
= task_event
->task
;
4014 int ret
, size
= task_event
->event_id
.header
.size
;
4016 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4018 ret
= perf_output_begin(&handle
, event
,
4019 task_event
->event_id
.header
.size
);
4023 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4024 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4026 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4027 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4029 perf_output_put(&handle
, task_event
->event_id
);
4031 perf_event__output_id_sample(event
, &handle
, &sample
);
4033 perf_output_end(&handle
);
4035 task_event
->event_id
.header
.size
= size
;
4038 static int perf_event_task_match(struct perf_event
*event
)
4040 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4043 if (!event_filter_match(event
))
4046 if (event
->attr
.comm
|| event
->attr
.mmap
||
4047 event
->attr
.mmap_data
|| event
->attr
.task
)
4053 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
4054 struct perf_task_event
*task_event
)
4056 struct perf_event
*event
;
4058 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4059 if (perf_event_task_match(event
))
4060 perf_event_task_output(event
, task_event
);
4064 static void perf_event_task_event(struct perf_task_event
*task_event
)
4066 struct perf_cpu_context
*cpuctx
;
4067 struct perf_event_context
*ctx
;
4072 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4073 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4074 if (cpuctx
->active_pmu
!= pmu
)
4076 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
4078 ctx
= task_event
->task_ctx
;
4080 ctxn
= pmu
->task_ctx_nr
;
4083 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4086 perf_event_task_ctx(ctx
, task_event
);
4088 put_cpu_ptr(pmu
->pmu_cpu_context
);
4093 static void perf_event_task(struct task_struct
*task
,
4094 struct perf_event_context
*task_ctx
,
4097 struct perf_task_event task_event
;
4099 if (!atomic_read(&nr_comm_events
) &&
4100 !atomic_read(&nr_mmap_events
) &&
4101 !atomic_read(&nr_task_events
))
4104 task_event
= (struct perf_task_event
){
4106 .task_ctx
= task_ctx
,
4109 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4111 .size
= sizeof(task_event
.event_id
),
4117 .time
= perf_clock(),
4121 perf_event_task_event(&task_event
);
4124 void perf_event_fork(struct task_struct
*task
)
4126 perf_event_task(task
, NULL
, 1);
4133 struct perf_comm_event
{
4134 struct task_struct
*task
;
4139 struct perf_event_header header
;
4146 static void perf_event_comm_output(struct perf_event
*event
,
4147 struct perf_comm_event
*comm_event
)
4149 struct perf_output_handle handle
;
4150 struct perf_sample_data sample
;
4151 int size
= comm_event
->event_id
.header
.size
;
4154 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4155 ret
= perf_output_begin(&handle
, event
,
4156 comm_event
->event_id
.header
.size
);
4161 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4162 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4164 perf_output_put(&handle
, comm_event
->event_id
);
4165 __output_copy(&handle
, comm_event
->comm
,
4166 comm_event
->comm_size
);
4168 perf_event__output_id_sample(event
, &handle
, &sample
);
4170 perf_output_end(&handle
);
4172 comm_event
->event_id
.header
.size
= size
;
4175 static int perf_event_comm_match(struct perf_event
*event
)
4177 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4180 if (!event_filter_match(event
))
4183 if (event
->attr
.comm
)
4189 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4190 struct perf_comm_event
*comm_event
)
4192 struct perf_event
*event
;
4194 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4195 if (perf_event_comm_match(event
))
4196 perf_event_comm_output(event
, comm_event
);
4200 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4202 struct perf_cpu_context
*cpuctx
;
4203 struct perf_event_context
*ctx
;
4204 char comm
[TASK_COMM_LEN
];
4209 memset(comm
, 0, sizeof(comm
));
4210 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4211 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4213 comm_event
->comm
= comm
;
4214 comm_event
->comm_size
= size
;
4216 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4218 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4219 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4220 if (cpuctx
->active_pmu
!= pmu
)
4222 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4224 ctxn
= pmu
->task_ctx_nr
;
4228 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4230 perf_event_comm_ctx(ctx
, comm_event
);
4232 put_cpu_ptr(pmu
->pmu_cpu_context
);
4237 void perf_event_comm(struct task_struct
*task
)
4239 struct perf_comm_event comm_event
;
4240 struct perf_event_context
*ctx
;
4243 for_each_task_context_nr(ctxn
) {
4244 ctx
= task
->perf_event_ctxp
[ctxn
];
4248 perf_event_enable_on_exec(ctx
);
4251 if (!atomic_read(&nr_comm_events
))
4254 comm_event
= (struct perf_comm_event
){
4260 .type
= PERF_RECORD_COMM
,
4269 perf_event_comm_event(&comm_event
);
4276 struct perf_mmap_event
{
4277 struct vm_area_struct
*vma
;
4279 const char *file_name
;
4283 struct perf_event_header header
;
4293 static void perf_event_mmap_output(struct perf_event
*event
,
4294 struct perf_mmap_event
*mmap_event
)
4296 struct perf_output_handle handle
;
4297 struct perf_sample_data sample
;
4298 int size
= mmap_event
->event_id
.header
.size
;
4301 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4302 ret
= perf_output_begin(&handle
, event
,
4303 mmap_event
->event_id
.header
.size
);
4307 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4308 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4310 perf_output_put(&handle
, mmap_event
->event_id
);
4311 __output_copy(&handle
, mmap_event
->file_name
,
4312 mmap_event
->file_size
);
4314 perf_event__output_id_sample(event
, &handle
, &sample
);
4316 perf_output_end(&handle
);
4318 mmap_event
->event_id
.header
.size
= size
;
4321 static int perf_event_mmap_match(struct perf_event
*event
,
4322 struct perf_mmap_event
*mmap_event
,
4325 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4328 if (!event_filter_match(event
))
4331 if ((!executable
&& event
->attr
.mmap_data
) ||
4332 (executable
&& event
->attr
.mmap
))
4338 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4339 struct perf_mmap_event
*mmap_event
,
4342 struct perf_event
*event
;
4344 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4345 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4346 perf_event_mmap_output(event
, mmap_event
);
4350 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4352 struct perf_cpu_context
*cpuctx
;
4353 struct perf_event_context
*ctx
;
4354 struct vm_area_struct
*vma
= mmap_event
->vma
;
4355 struct file
*file
= vma
->vm_file
;
4363 memset(tmp
, 0, sizeof(tmp
));
4367 * d_path works from the end of the rb backwards, so we
4368 * need to add enough zero bytes after the string to handle
4369 * the 64bit alignment we do later.
4371 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4373 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4376 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4378 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4382 if (arch_vma_name(mmap_event
->vma
)) {
4383 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4389 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4391 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4392 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4393 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4395 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4396 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4397 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4401 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4406 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4408 mmap_event
->file_name
= name
;
4409 mmap_event
->file_size
= size
;
4411 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4414 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4415 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4416 if (cpuctx
->active_pmu
!= pmu
)
4418 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4419 vma
->vm_flags
& VM_EXEC
);
4421 ctxn
= pmu
->task_ctx_nr
;
4425 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4427 perf_event_mmap_ctx(ctx
, mmap_event
,
4428 vma
->vm_flags
& VM_EXEC
);
4431 put_cpu_ptr(pmu
->pmu_cpu_context
);
4438 void perf_event_mmap(struct vm_area_struct
*vma
)
4440 struct perf_mmap_event mmap_event
;
4442 if (!atomic_read(&nr_mmap_events
))
4445 mmap_event
= (struct perf_mmap_event
){
4451 .type
= PERF_RECORD_MMAP
,
4452 .misc
= PERF_RECORD_MISC_USER
,
4457 .start
= vma
->vm_start
,
4458 .len
= vma
->vm_end
- vma
->vm_start
,
4459 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4463 perf_event_mmap_event(&mmap_event
);
4467 * IRQ throttle logging
4470 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4472 struct perf_output_handle handle
;
4473 struct perf_sample_data sample
;
4477 struct perf_event_header header
;
4481 } throttle_event
= {
4483 .type
= PERF_RECORD_THROTTLE
,
4485 .size
= sizeof(throttle_event
),
4487 .time
= perf_clock(),
4488 .id
= primary_event_id(event
),
4489 .stream_id
= event
->id
,
4493 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4495 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4497 ret
= perf_output_begin(&handle
, event
,
4498 throttle_event
.header
.size
);
4502 perf_output_put(&handle
, throttle_event
);
4503 perf_event__output_id_sample(event
, &handle
, &sample
);
4504 perf_output_end(&handle
);
4508 * Generic event overflow handling, sampling.
4511 static int __perf_event_overflow(struct perf_event
*event
,
4512 int throttle
, struct perf_sample_data
*data
,
4513 struct pt_regs
*regs
)
4515 int events
= atomic_read(&event
->event_limit
);
4516 struct hw_perf_event
*hwc
= &event
->hw
;
4520 * Non-sampling counters might still use the PMI to fold short
4521 * hardware counters, ignore those.
4523 if (unlikely(!is_sampling_event(event
)))
4526 if (unlikely(hwc
->interrupts
>= max_samples_per_tick
)) {
4528 hwc
->interrupts
= MAX_INTERRUPTS
;
4529 perf_log_throttle(event
, 0);
4535 if (event
->attr
.freq
) {
4536 u64 now
= perf_clock();
4537 s64 delta
= now
- hwc
->freq_time_stamp
;
4539 hwc
->freq_time_stamp
= now
;
4541 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4542 perf_adjust_period(event
, delta
, hwc
->last_period
);
4546 * XXX event_limit might not quite work as expected on inherited
4550 event
->pending_kill
= POLL_IN
;
4551 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4553 event
->pending_kill
= POLL_HUP
;
4554 event
->pending_disable
= 1;
4555 irq_work_queue(&event
->pending
);
4558 if (event
->overflow_handler
)
4559 event
->overflow_handler(event
, data
, regs
);
4561 perf_event_output(event
, data
, regs
);
4563 if (event
->fasync
&& event
->pending_kill
) {
4564 event
->pending_wakeup
= 1;
4565 irq_work_queue(&event
->pending
);
4571 int perf_event_overflow(struct perf_event
*event
,
4572 struct perf_sample_data
*data
,
4573 struct pt_regs
*regs
)
4575 return __perf_event_overflow(event
, 1, data
, regs
);
4579 * Generic software event infrastructure
4582 struct swevent_htable
{
4583 struct swevent_hlist
*swevent_hlist
;
4584 struct mutex hlist_mutex
;
4587 /* Recursion avoidance in each contexts */
4588 int recursion
[PERF_NR_CONTEXTS
];
4591 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
4594 * We directly increment event->count and keep a second value in
4595 * event->hw.period_left to count intervals. This period event
4596 * is kept in the range [-sample_period, 0] so that we can use the
4600 static u64
perf_swevent_set_period(struct perf_event
*event
)
4602 struct hw_perf_event
*hwc
= &event
->hw
;
4603 u64 period
= hwc
->last_period
;
4607 hwc
->last_period
= hwc
->sample_period
;
4610 old
= val
= local64_read(&hwc
->period_left
);
4614 nr
= div64_u64(period
+ val
, period
);
4615 offset
= nr
* period
;
4617 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
4623 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
4624 struct perf_sample_data
*data
,
4625 struct pt_regs
*regs
)
4627 struct hw_perf_event
*hwc
= &event
->hw
;
4631 overflow
= perf_swevent_set_period(event
);
4633 if (hwc
->interrupts
== MAX_INTERRUPTS
)
4636 for (; overflow
; overflow
--) {
4637 if (__perf_event_overflow(event
, throttle
,
4640 * We inhibit the overflow from happening when
4641 * hwc->interrupts == MAX_INTERRUPTS.
4649 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
4650 struct perf_sample_data
*data
,
4651 struct pt_regs
*regs
)
4653 struct hw_perf_event
*hwc
= &event
->hw
;
4655 local64_add(nr
, &event
->count
);
4660 if (!is_sampling_event(event
))
4663 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
4665 return perf_swevent_overflow(event
, 1, data
, regs
);
4667 data
->period
= event
->hw
.last_period
;
4669 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
4670 return perf_swevent_overflow(event
, 1, data
, regs
);
4672 if (local64_add_negative(nr
, &hwc
->period_left
))
4675 perf_swevent_overflow(event
, 0, data
, regs
);
4678 static int perf_exclude_event(struct perf_event
*event
,
4679 struct pt_regs
*regs
)
4681 if (event
->hw
.state
& PERF_HES_STOPPED
)
4685 if (event
->attr
.exclude_user
&& user_mode(regs
))
4688 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4695 static int perf_swevent_match(struct perf_event
*event
,
4696 enum perf_type_id type
,
4698 struct perf_sample_data
*data
,
4699 struct pt_regs
*regs
)
4701 if (event
->attr
.type
!= type
)
4704 if (event
->attr
.config
!= event_id
)
4707 if (perf_exclude_event(event
, regs
))
4713 static inline u64
swevent_hash(u64 type
, u32 event_id
)
4715 u64 val
= event_id
| (type
<< 32);
4717 return hash_64(val
, SWEVENT_HLIST_BITS
);
4720 static inline struct hlist_head
*
4721 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
4723 u64 hash
= swevent_hash(type
, event_id
);
4725 return &hlist
->heads
[hash
];
4728 /* For the read side: events when they trigger */
4729 static inline struct hlist_head
*
4730 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
4732 struct swevent_hlist
*hlist
;
4734 hlist
= rcu_dereference(swhash
->swevent_hlist
);
4738 return __find_swevent_head(hlist
, type
, event_id
);
4741 /* For the event head insertion and removal in the hlist */
4742 static inline struct hlist_head
*
4743 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
4745 struct swevent_hlist
*hlist
;
4746 u32 event_id
= event
->attr
.config
;
4747 u64 type
= event
->attr
.type
;
4750 * Event scheduling is always serialized against hlist allocation
4751 * and release. Which makes the protected version suitable here.
4752 * The context lock guarantees that.
4754 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
4755 lockdep_is_held(&event
->ctx
->lock
));
4759 return __find_swevent_head(hlist
, type
, event_id
);
4762 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4764 struct perf_sample_data
*data
,
4765 struct pt_regs
*regs
)
4767 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4768 struct perf_event
*event
;
4769 struct hlist_node
*node
;
4770 struct hlist_head
*head
;
4773 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
4777 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4778 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4779 perf_swevent_event(event
, nr
, data
, regs
);
4785 int perf_swevent_get_recursion_context(void)
4787 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4789 return get_recursion_context(swhash
->recursion
);
4791 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4793 inline void perf_swevent_put_recursion_context(int rctx
)
4795 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4797 put_recursion_context(swhash
->recursion
, rctx
);
4800 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
4802 struct perf_sample_data data
;
4805 preempt_disable_notrace();
4806 rctx
= perf_swevent_get_recursion_context();
4810 perf_sample_data_init(&data
, addr
);
4812 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
4814 perf_swevent_put_recursion_context(rctx
);
4815 preempt_enable_notrace();
4818 static void perf_swevent_read(struct perf_event
*event
)
4822 static int perf_swevent_add(struct perf_event
*event
, int flags
)
4824 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4825 struct hw_perf_event
*hwc
= &event
->hw
;
4826 struct hlist_head
*head
;
4828 if (is_sampling_event(event
)) {
4829 hwc
->last_period
= hwc
->sample_period
;
4830 perf_swevent_set_period(event
);
4833 hwc
->state
= !(flags
& PERF_EF_START
);
4835 head
= find_swevent_head(swhash
, event
);
4836 if (WARN_ON_ONCE(!head
))
4839 hlist_add_head_rcu(&event
->hlist_entry
, head
);
4844 static void perf_swevent_del(struct perf_event
*event
, int flags
)
4846 hlist_del_rcu(&event
->hlist_entry
);
4849 static void perf_swevent_start(struct perf_event
*event
, int flags
)
4851 event
->hw
.state
= 0;
4854 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
4856 event
->hw
.state
= PERF_HES_STOPPED
;
4859 /* Deref the hlist from the update side */
4860 static inline struct swevent_hlist
*
4861 swevent_hlist_deref(struct swevent_htable
*swhash
)
4863 return rcu_dereference_protected(swhash
->swevent_hlist
,
4864 lockdep_is_held(&swhash
->hlist_mutex
));
4867 static void swevent_hlist_release(struct swevent_htable
*swhash
)
4869 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
4874 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
4875 kfree_rcu(hlist
, rcu_head
);
4878 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
4880 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4882 mutex_lock(&swhash
->hlist_mutex
);
4884 if (!--swhash
->hlist_refcount
)
4885 swevent_hlist_release(swhash
);
4887 mutex_unlock(&swhash
->hlist_mutex
);
4890 static void swevent_hlist_put(struct perf_event
*event
)
4894 if (event
->cpu
!= -1) {
4895 swevent_hlist_put_cpu(event
, event
->cpu
);
4899 for_each_possible_cpu(cpu
)
4900 swevent_hlist_put_cpu(event
, cpu
);
4903 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
4905 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4908 mutex_lock(&swhash
->hlist_mutex
);
4910 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
4911 struct swevent_hlist
*hlist
;
4913 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
4918 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
4920 swhash
->hlist_refcount
++;
4922 mutex_unlock(&swhash
->hlist_mutex
);
4927 static int swevent_hlist_get(struct perf_event
*event
)
4930 int cpu
, failed_cpu
;
4932 if (event
->cpu
!= -1)
4933 return swevent_hlist_get_cpu(event
, event
->cpu
);
4936 for_each_possible_cpu(cpu
) {
4937 err
= swevent_hlist_get_cpu(event
, cpu
);
4947 for_each_possible_cpu(cpu
) {
4948 if (cpu
== failed_cpu
)
4950 swevent_hlist_put_cpu(event
, cpu
);
4957 struct jump_label_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4959 static void sw_perf_event_destroy(struct perf_event
*event
)
4961 u64 event_id
= event
->attr
.config
;
4963 WARN_ON(event
->parent
);
4965 jump_label_dec(&perf_swevent_enabled
[event_id
]);
4966 swevent_hlist_put(event
);
4969 static int perf_swevent_init(struct perf_event
*event
)
4971 int event_id
= event
->attr
.config
;
4973 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
4977 case PERF_COUNT_SW_CPU_CLOCK
:
4978 case PERF_COUNT_SW_TASK_CLOCK
:
4985 if (event_id
>= PERF_COUNT_SW_MAX
)
4988 if (!event
->parent
) {
4991 err
= swevent_hlist_get(event
);
4995 jump_label_inc(&perf_swevent_enabled
[event_id
]);
4996 event
->destroy
= sw_perf_event_destroy
;
5002 static int perf_swevent_event_idx(struct perf_event
*event
)
5007 static struct pmu perf_swevent
= {
5008 .task_ctx_nr
= perf_sw_context
,
5010 .event_init
= perf_swevent_init
,
5011 .add
= perf_swevent_add
,
5012 .del
= perf_swevent_del
,
5013 .start
= perf_swevent_start
,
5014 .stop
= perf_swevent_stop
,
5015 .read
= perf_swevent_read
,
5017 .event_idx
= perf_swevent_event_idx
,
5020 #ifdef CONFIG_EVENT_TRACING
5022 static int perf_tp_filter_match(struct perf_event
*event
,
5023 struct perf_sample_data
*data
)
5025 void *record
= data
->raw
->data
;
5027 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5032 static int perf_tp_event_match(struct perf_event
*event
,
5033 struct perf_sample_data
*data
,
5034 struct pt_regs
*regs
)
5036 if (event
->hw
.state
& PERF_HES_STOPPED
)
5039 * All tracepoints are from kernel-space.
5041 if (event
->attr
.exclude_kernel
)
5044 if (!perf_tp_filter_match(event
, data
))
5050 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5051 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
5053 struct perf_sample_data data
;
5054 struct perf_event
*event
;
5055 struct hlist_node
*node
;
5057 struct perf_raw_record raw
= {
5062 perf_sample_data_init(&data
, addr
);
5065 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5066 if (perf_tp_event_match(event
, &data
, regs
))
5067 perf_swevent_event(event
, count
, &data
, regs
);
5070 perf_swevent_put_recursion_context(rctx
);
5072 EXPORT_SYMBOL_GPL(perf_tp_event
);
5074 static void tp_perf_event_destroy(struct perf_event
*event
)
5076 perf_trace_destroy(event
);
5079 static int perf_tp_event_init(struct perf_event
*event
)
5083 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5086 err
= perf_trace_init(event
);
5090 event
->destroy
= tp_perf_event_destroy
;
5095 static struct pmu perf_tracepoint
= {
5096 .task_ctx_nr
= perf_sw_context
,
5098 .event_init
= perf_tp_event_init
,
5099 .add
= perf_trace_add
,
5100 .del
= perf_trace_del
,
5101 .start
= perf_swevent_start
,
5102 .stop
= perf_swevent_stop
,
5103 .read
= perf_swevent_read
,
5105 .event_idx
= perf_swevent_event_idx
,
5108 static inline void perf_tp_register(void)
5110 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5113 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5118 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5121 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5122 if (IS_ERR(filter_str
))
5123 return PTR_ERR(filter_str
);
5125 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5131 static void perf_event_free_filter(struct perf_event
*event
)
5133 ftrace_profile_free_filter(event
);
5138 static inline void perf_tp_register(void)
5142 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5147 static void perf_event_free_filter(struct perf_event
*event
)
5151 #endif /* CONFIG_EVENT_TRACING */
5153 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5154 void perf_bp_event(struct perf_event
*bp
, void *data
)
5156 struct perf_sample_data sample
;
5157 struct pt_regs
*regs
= data
;
5159 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
5161 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5162 perf_swevent_event(bp
, 1, &sample
, regs
);
5167 * hrtimer based swevent callback
5170 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5172 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5173 struct perf_sample_data data
;
5174 struct pt_regs
*regs
;
5175 struct perf_event
*event
;
5178 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5180 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5181 return HRTIMER_NORESTART
;
5183 event
->pmu
->read(event
);
5185 perf_sample_data_init(&data
, 0);
5186 data
.period
= event
->hw
.last_period
;
5187 regs
= get_irq_regs();
5189 if (regs
&& !perf_exclude_event(event
, regs
)) {
5190 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
5191 if (perf_event_overflow(event
, &data
, regs
))
5192 ret
= HRTIMER_NORESTART
;
5195 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5196 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5201 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5203 struct hw_perf_event
*hwc
= &event
->hw
;
5206 if (!is_sampling_event(event
))
5209 period
= local64_read(&hwc
->period_left
);
5214 local64_set(&hwc
->period_left
, 0);
5216 period
= max_t(u64
, 10000, hwc
->sample_period
);
5218 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5219 ns_to_ktime(period
), 0,
5220 HRTIMER_MODE_REL_PINNED
, 0);
5223 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5225 struct hw_perf_event
*hwc
= &event
->hw
;
5227 if (is_sampling_event(event
)) {
5228 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5229 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5231 hrtimer_cancel(&hwc
->hrtimer
);
5235 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
5237 struct hw_perf_event
*hwc
= &event
->hw
;
5239 if (!is_sampling_event(event
))
5242 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5243 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5246 * Since hrtimers have a fixed rate, we can do a static freq->period
5247 * mapping and avoid the whole period adjust feedback stuff.
5249 if (event
->attr
.freq
) {
5250 long freq
= event
->attr
.sample_freq
;
5252 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
5253 hwc
->sample_period
= event
->attr
.sample_period
;
5254 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5255 event
->attr
.freq
= 0;
5260 * Software event: cpu wall time clock
5263 static void cpu_clock_event_update(struct perf_event
*event
)
5268 now
= local_clock();
5269 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5270 local64_add(now
- prev
, &event
->count
);
5273 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5275 local64_set(&event
->hw
.prev_count
, local_clock());
5276 perf_swevent_start_hrtimer(event
);
5279 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5281 perf_swevent_cancel_hrtimer(event
);
5282 cpu_clock_event_update(event
);
5285 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5287 if (flags
& PERF_EF_START
)
5288 cpu_clock_event_start(event
, flags
);
5293 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5295 cpu_clock_event_stop(event
, flags
);
5298 static void cpu_clock_event_read(struct perf_event
*event
)
5300 cpu_clock_event_update(event
);
5303 static int cpu_clock_event_init(struct perf_event
*event
)
5305 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5308 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5311 perf_swevent_init_hrtimer(event
);
5316 static struct pmu perf_cpu_clock
= {
5317 .task_ctx_nr
= perf_sw_context
,
5319 .event_init
= cpu_clock_event_init
,
5320 .add
= cpu_clock_event_add
,
5321 .del
= cpu_clock_event_del
,
5322 .start
= cpu_clock_event_start
,
5323 .stop
= cpu_clock_event_stop
,
5324 .read
= cpu_clock_event_read
,
5326 .event_idx
= perf_swevent_event_idx
,
5330 * Software event: task time clock
5333 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5338 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5340 local64_add(delta
, &event
->count
);
5343 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5345 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5346 perf_swevent_start_hrtimer(event
);
5349 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5351 perf_swevent_cancel_hrtimer(event
);
5352 task_clock_event_update(event
, event
->ctx
->time
);
5355 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5357 if (flags
& PERF_EF_START
)
5358 task_clock_event_start(event
, flags
);
5363 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5365 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5368 static void task_clock_event_read(struct perf_event
*event
)
5370 u64 now
= perf_clock();
5371 u64 delta
= now
- event
->ctx
->timestamp
;
5372 u64 time
= event
->ctx
->time
+ delta
;
5374 task_clock_event_update(event
, time
);
5377 static int task_clock_event_init(struct perf_event
*event
)
5379 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5382 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5385 perf_swevent_init_hrtimer(event
);
5390 static struct pmu perf_task_clock
= {
5391 .task_ctx_nr
= perf_sw_context
,
5393 .event_init
= task_clock_event_init
,
5394 .add
= task_clock_event_add
,
5395 .del
= task_clock_event_del
,
5396 .start
= task_clock_event_start
,
5397 .stop
= task_clock_event_stop
,
5398 .read
= task_clock_event_read
,
5400 .event_idx
= perf_swevent_event_idx
,
5403 static void perf_pmu_nop_void(struct pmu
*pmu
)
5407 static int perf_pmu_nop_int(struct pmu
*pmu
)
5412 static void perf_pmu_start_txn(struct pmu
*pmu
)
5414 perf_pmu_disable(pmu
);
5417 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5419 perf_pmu_enable(pmu
);
5423 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5425 perf_pmu_enable(pmu
);
5428 static int perf_event_idx_default(struct perf_event
*event
)
5430 return event
->hw
.idx
+ 1;
5434 * Ensures all contexts with the same task_ctx_nr have the same
5435 * pmu_cpu_context too.
5437 static void *find_pmu_context(int ctxn
)
5444 list_for_each_entry(pmu
, &pmus
, entry
) {
5445 if (pmu
->task_ctx_nr
== ctxn
)
5446 return pmu
->pmu_cpu_context
;
5452 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5456 for_each_possible_cpu(cpu
) {
5457 struct perf_cpu_context
*cpuctx
;
5459 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5461 if (cpuctx
->active_pmu
== old_pmu
)
5462 cpuctx
->active_pmu
= pmu
;
5466 static void free_pmu_context(struct pmu
*pmu
)
5470 mutex_lock(&pmus_lock
);
5472 * Like a real lame refcount.
5474 list_for_each_entry(i
, &pmus
, entry
) {
5475 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5476 update_pmu_context(i
, pmu
);
5481 free_percpu(pmu
->pmu_cpu_context
);
5483 mutex_unlock(&pmus_lock
);
5485 static struct idr pmu_idr
;
5488 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5490 struct pmu
*pmu
= dev_get_drvdata(dev
);
5492 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5495 static struct device_attribute pmu_dev_attrs
[] = {
5500 static int pmu_bus_running
;
5501 static struct bus_type pmu_bus
= {
5502 .name
= "event_source",
5503 .dev_attrs
= pmu_dev_attrs
,
5506 static void pmu_dev_release(struct device
*dev
)
5511 static int pmu_dev_alloc(struct pmu
*pmu
)
5515 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5519 pmu
->dev
->groups
= pmu
->attr_groups
;
5520 device_initialize(pmu
->dev
);
5521 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5525 dev_set_drvdata(pmu
->dev
, pmu
);
5526 pmu
->dev
->bus
= &pmu_bus
;
5527 pmu
->dev
->release
= pmu_dev_release
;
5528 ret
= device_add(pmu
->dev
);
5536 put_device(pmu
->dev
);
5540 static struct lock_class_key cpuctx_mutex
;
5541 static struct lock_class_key cpuctx_lock
;
5543 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5547 mutex_lock(&pmus_lock
);
5549 pmu
->pmu_disable_count
= alloc_percpu(int);
5550 if (!pmu
->pmu_disable_count
)
5559 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
5563 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
5571 if (pmu_bus_running
) {
5572 ret
= pmu_dev_alloc(pmu
);
5578 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
5579 if (pmu
->pmu_cpu_context
)
5580 goto got_cpu_context
;
5582 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
5583 if (!pmu
->pmu_cpu_context
)
5586 for_each_possible_cpu(cpu
) {
5587 struct perf_cpu_context
*cpuctx
;
5589 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5590 __perf_event_init_context(&cpuctx
->ctx
);
5591 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
5592 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
5593 cpuctx
->ctx
.type
= cpu_context
;
5594 cpuctx
->ctx
.pmu
= pmu
;
5595 cpuctx
->jiffies_interval
= 1;
5596 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
5597 cpuctx
->active_pmu
= pmu
;
5601 if (!pmu
->start_txn
) {
5602 if (pmu
->pmu_enable
) {
5604 * If we have pmu_enable/pmu_disable calls, install
5605 * transaction stubs that use that to try and batch
5606 * hardware accesses.
5608 pmu
->start_txn
= perf_pmu_start_txn
;
5609 pmu
->commit_txn
= perf_pmu_commit_txn
;
5610 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
5612 pmu
->start_txn
= perf_pmu_nop_void
;
5613 pmu
->commit_txn
= perf_pmu_nop_int
;
5614 pmu
->cancel_txn
= perf_pmu_nop_void
;
5618 if (!pmu
->pmu_enable
) {
5619 pmu
->pmu_enable
= perf_pmu_nop_void
;
5620 pmu
->pmu_disable
= perf_pmu_nop_void
;
5623 if (!pmu
->event_idx
)
5624 pmu
->event_idx
= perf_event_idx_default
;
5626 list_add_rcu(&pmu
->entry
, &pmus
);
5629 mutex_unlock(&pmus_lock
);
5634 device_del(pmu
->dev
);
5635 put_device(pmu
->dev
);
5638 if (pmu
->type
>= PERF_TYPE_MAX
)
5639 idr_remove(&pmu_idr
, pmu
->type
);
5642 free_percpu(pmu
->pmu_disable_count
);
5646 void perf_pmu_unregister(struct pmu
*pmu
)
5648 mutex_lock(&pmus_lock
);
5649 list_del_rcu(&pmu
->entry
);
5650 mutex_unlock(&pmus_lock
);
5653 * We dereference the pmu list under both SRCU and regular RCU, so
5654 * synchronize against both of those.
5656 synchronize_srcu(&pmus_srcu
);
5659 free_percpu(pmu
->pmu_disable_count
);
5660 if (pmu
->type
>= PERF_TYPE_MAX
)
5661 idr_remove(&pmu_idr
, pmu
->type
);
5662 device_del(pmu
->dev
);
5663 put_device(pmu
->dev
);
5664 free_pmu_context(pmu
);
5667 struct pmu
*perf_init_event(struct perf_event
*event
)
5669 struct pmu
*pmu
= NULL
;
5673 idx
= srcu_read_lock(&pmus_srcu
);
5676 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
5680 ret
= pmu
->event_init(event
);
5686 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5688 ret
= pmu
->event_init(event
);
5692 if (ret
!= -ENOENT
) {
5697 pmu
= ERR_PTR(-ENOENT
);
5699 srcu_read_unlock(&pmus_srcu
, idx
);
5705 * Allocate and initialize a event structure
5707 static struct perf_event
*
5708 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
5709 struct task_struct
*task
,
5710 struct perf_event
*group_leader
,
5711 struct perf_event
*parent_event
,
5712 perf_overflow_handler_t overflow_handler
,
5716 struct perf_event
*event
;
5717 struct hw_perf_event
*hwc
;
5720 if ((unsigned)cpu
>= nr_cpu_ids
) {
5721 if (!task
|| cpu
!= -1)
5722 return ERR_PTR(-EINVAL
);
5725 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
5727 return ERR_PTR(-ENOMEM
);
5730 * Single events are their own group leaders, with an
5731 * empty sibling list:
5734 group_leader
= event
;
5736 mutex_init(&event
->child_mutex
);
5737 INIT_LIST_HEAD(&event
->child_list
);
5739 INIT_LIST_HEAD(&event
->group_entry
);
5740 INIT_LIST_HEAD(&event
->event_entry
);
5741 INIT_LIST_HEAD(&event
->sibling_list
);
5742 INIT_LIST_HEAD(&event
->rb_entry
);
5744 init_waitqueue_head(&event
->waitq
);
5745 init_irq_work(&event
->pending
, perf_pending_event
);
5747 mutex_init(&event
->mmap_mutex
);
5750 event
->attr
= *attr
;
5751 event
->group_leader
= group_leader
;
5755 event
->parent
= parent_event
;
5757 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
5758 event
->id
= atomic64_inc_return(&perf_event_id
);
5760 event
->state
= PERF_EVENT_STATE_INACTIVE
;
5763 event
->attach_state
= PERF_ATTACH_TASK
;
5764 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5766 * hw_breakpoint is a bit difficult here..
5768 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
5769 event
->hw
.bp_target
= task
;
5773 if (!overflow_handler
&& parent_event
) {
5774 overflow_handler
= parent_event
->overflow_handler
;
5775 context
= parent_event
->overflow_handler_context
;
5778 event
->overflow_handler
= overflow_handler
;
5779 event
->overflow_handler_context
= context
;
5782 event
->state
= PERF_EVENT_STATE_OFF
;
5787 hwc
->sample_period
= attr
->sample_period
;
5788 if (attr
->freq
&& attr
->sample_freq
)
5789 hwc
->sample_period
= 1;
5790 hwc
->last_period
= hwc
->sample_period
;
5792 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5795 * we currently do not support PERF_FORMAT_GROUP on inherited events
5797 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
5800 pmu
= perf_init_event(event
);
5806 else if (IS_ERR(pmu
))
5811 put_pid_ns(event
->ns
);
5813 return ERR_PTR(err
);
5816 if (!event
->parent
) {
5817 if (event
->attach_state
& PERF_ATTACH_TASK
)
5818 jump_label_inc(&perf_sched_events
.key
);
5819 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
5820 atomic_inc(&nr_mmap_events
);
5821 if (event
->attr
.comm
)
5822 atomic_inc(&nr_comm_events
);
5823 if (event
->attr
.task
)
5824 atomic_inc(&nr_task_events
);
5825 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5826 err
= get_callchain_buffers();
5829 return ERR_PTR(err
);
5837 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5838 struct perf_event_attr
*attr
)
5843 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
5847 * zero the full structure, so that a short copy will be nice.
5849 memset(attr
, 0, sizeof(*attr
));
5851 ret
= get_user(size
, &uattr
->size
);
5855 if (size
> PAGE_SIZE
) /* silly large */
5858 if (!size
) /* abi compat */
5859 size
= PERF_ATTR_SIZE_VER0
;
5861 if (size
< PERF_ATTR_SIZE_VER0
)
5865 * If we're handed a bigger struct than we know of,
5866 * ensure all the unknown bits are 0 - i.e. new
5867 * user-space does not rely on any kernel feature
5868 * extensions we dont know about yet.
5870 if (size
> sizeof(*attr
)) {
5871 unsigned char __user
*addr
;
5872 unsigned char __user
*end
;
5875 addr
= (void __user
*)uattr
+ sizeof(*attr
);
5876 end
= (void __user
*)uattr
+ size
;
5878 for (; addr
< end
; addr
++) {
5879 ret
= get_user(val
, addr
);
5885 size
= sizeof(*attr
);
5888 ret
= copy_from_user(attr
, uattr
, size
);
5892 if (attr
->__reserved_1
)
5895 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
5898 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
5905 put_user(sizeof(*attr
), &uattr
->size
);
5911 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
5913 struct ring_buffer
*rb
= NULL
, *old_rb
= NULL
;
5919 /* don't allow circular references */
5920 if (event
== output_event
)
5924 * Don't allow cross-cpu buffers
5926 if (output_event
->cpu
!= event
->cpu
)
5930 * If its not a per-cpu rb, it must be the same task.
5932 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
5936 mutex_lock(&event
->mmap_mutex
);
5937 /* Can't redirect output if we've got an active mmap() */
5938 if (atomic_read(&event
->mmap_count
))
5942 /* get the rb we want to redirect to */
5943 rb
= ring_buffer_get(output_event
);
5949 rcu_assign_pointer(event
->rb
, rb
);
5951 ring_buffer_detach(event
, old_rb
);
5954 mutex_unlock(&event
->mmap_mutex
);
5957 ring_buffer_put(old_rb
);
5963 * sys_perf_event_open - open a performance event, associate it to a task/cpu
5965 * @attr_uptr: event_id type attributes for monitoring/sampling
5968 * @group_fd: group leader event fd
5970 SYSCALL_DEFINE5(perf_event_open
,
5971 struct perf_event_attr __user
*, attr_uptr
,
5972 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
5974 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
5975 struct perf_event
*event
, *sibling
;
5976 struct perf_event_attr attr
;
5977 struct perf_event_context
*ctx
;
5978 struct file
*event_file
= NULL
;
5979 struct file
*group_file
= NULL
;
5980 struct task_struct
*task
= NULL
;
5984 int fput_needed
= 0;
5987 /* for future expandability... */
5988 if (flags
& ~PERF_FLAG_ALL
)
5991 err
= perf_copy_attr(attr_uptr
, &attr
);
5995 if (!attr
.exclude_kernel
) {
5996 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
6001 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
6006 * In cgroup mode, the pid argument is used to pass the fd
6007 * opened to the cgroup directory in cgroupfs. The cpu argument
6008 * designates the cpu on which to monitor threads from that
6011 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
6014 event_fd
= get_unused_fd_flags(O_RDWR
);
6018 if (group_fd
!= -1) {
6019 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
6020 if (IS_ERR(group_leader
)) {
6021 err
= PTR_ERR(group_leader
);
6024 group_file
= group_leader
->filp
;
6025 if (flags
& PERF_FLAG_FD_OUTPUT
)
6026 output_event
= group_leader
;
6027 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6028 group_leader
= NULL
;
6031 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6032 task
= find_lively_task_by_vpid(pid
);
6034 err
= PTR_ERR(task
);
6039 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
6041 if (IS_ERR(event
)) {
6042 err
= PTR_ERR(event
);
6046 if (flags
& PERF_FLAG_PID_CGROUP
) {
6047 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6052 * - that has cgroup constraint on event->cpu
6053 * - that may need work on context switch
6055 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
6056 jump_label_inc(&perf_sched_events
.key
);
6060 * Special case software events and allow them to be part of
6061 * any hardware group.
6066 (is_software_event(event
) != is_software_event(group_leader
))) {
6067 if (is_software_event(event
)) {
6069 * If event and group_leader are not both a software
6070 * event, and event is, then group leader is not.
6072 * Allow the addition of software events to !software
6073 * groups, this is safe because software events never
6076 pmu
= group_leader
->pmu
;
6077 } else if (is_software_event(group_leader
) &&
6078 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6080 * In case the group is a pure software group, and we
6081 * try to add a hardware event, move the whole group to
6082 * the hardware context.
6089 * Get the target context (task or percpu):
6091 ctx
= find_get_context(pmu
, task
, cpu
);
6098 put_task_struct(task
);
6103 * Look up the group leader (we will attach this event to it):
6109 * Do not allow a recursive hierarchy (this new sibling
6110 * becoming part of another group-sibling):
6112 if (group_leader
->group_leader
!= group_leader
)
6115 * Do not allow to attach to a group in a different
6116 * task or CPU context:
6119 if (group_leader
->ctx
->type
!= ctx
->type
)
6122 if (group_leader
->ctx
!= ctx
)
6127 * Only a group leader can be exclusive or pinned
6129 if (attr
.exclusive
|| attr
.pinned
)
6134 err
= perf_event_set_output(event
, output_event
);
6139 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6140 if (IS_ERR(event_file
)) {
6141 err
= PTR_ERR(event_file
);
6146 struct perf_event_context
*gctx
= group_leader
->ctx
;
6148 mutex_lock(&gctx
->mutex
);
6149 perf_remove_from_context(group_leader
);
6150 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6152 perf_remove_from_context(sibling
);
6155 mutex_unlock(&gctx
->mutex
);
6159 event
->filp
= event_file
;
6160 WARN_ON_ONCE(ctx
->parent_ctx
);
6161 mutex_lock(&ctx
->mutex
);
6164 perf_install_in_context(ctx
, group_leader
, cpu
);
6166 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6168 perf_install_in_context(ctx
, sibling
, cpu
);
6173 perf_install_in_context(ctx
, event
, cpu
);
6175 perf_unpin_context(ctx
);
6176 mutex_unlock(&ctx
->mutex
);
6178 event
->owner
= current
;
6180 mutex_lock(¤t
->perf_event_mutex
);
6181 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6182 mutex_unlock(¤t
->perf_event_mutex
);
6185 * Precalculate sample_data sizes
6187 perf_event__header_size(event
);
6188 perf_event__id_header_size(event
);
6191 * Drop the reference on the group_event after placing the
6192 * new event on the sibling_list. This ensures destruction
6193 * of the group leader will find the pointer to itself in
6194 * perf_group_detach().
6196 fput_light(group_file
, fput_needed
);
6197 fd_install(event_fd
, event_file
);
6201 perf_unpin_context(ctx
);
6207 put_task_struct(task
);
6209 fput_light(group_file
, fput_needed
);
6211 put_unused_fd(event_fd
);
6216 * perf_event_create_kernel_counter
6218 * @attr: attributes of the counter to create
6219 * @cpu: cpu in which the counter is bound
6220 * @task: task to profile (NULL for percpu)
6223 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6224 struct task_struct
*task
,
6225 perf_overflow_handler_t overflow_handler
,
6228 struct perf_event_context
*ctx
;
6229 struct perf_event
*event
;
6233 * Get the target context (task or percpu):
6236 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
6237 overflow_handler
, context
);
6238 if (IS_ERR(event
)) {
6239 err
= PTR_ERR(event
);
6243 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6250 WARN_ON_ONCE(ctx
->parent_ctx
);
6251 mutex_lock(&ctx
->mutex
);
6252 perf_install_in_context(ctx
, event
, cpu
);
6254 perf_unpin_context(ctx
);
6255 mutex_unlock(&ctx
->mutex
);
6262 return ERR_PTR(err
);
6264 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6266 static void sync_child_event(struct perf_event
*child_event
,
6267 struct task_struct
*child
)
6269 struct perf_event
*parent_event
= child_event
->parent
;
6272 if (child_event
->attr
.inherit_stat
)
6273 perf_event_read_event(child_event
, child
);
6275 child_val
= perf_event_count(child_event
);
6278 * Add back the child's count to the parent's count:
6280 atomic64_add(child_val
, &parent_event
->child_count
);
6281 atomic64_add(child_event
->total_time_enabled
,
6282 &parent_event
->child_total_time_enabled
);
6283 atomic64_add(child_event
->total_time_running
,
6284 &parent_event
->child_total_time_running
);
6287 * Remove this event from the parent's list
6289 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6290 mutex_lock(&parent_event
->child_mutex
);
6291 list_del_init(&child_event
->child_list
);
6292 mutex_unlock(&parent_event
->child_mutex
);
6295 * Release the parent event, if this was the last
6298 fput(parent_event
->filp
);
6302 __perf_event_exit_task(struct perf_event
*child_event
,
6303 struct perf_event_context
*child_ctx
,
6304 struct task_struct
*child
)
6306 if (child_event
->parent
) {
6307 raw_spin_lock_irq(&child_ctx
->lock
);
6308 perf_group_detach(child_event
);
6309 raw_spin_unlock_irq(&child_ctx
->lock
);
6312 perf_remove_from_context(child_event
);
6315 * It can happen that the parent exits first, and has events
6316 * that are still around due to the child reference. These
6317 * events need to be zapped.
6319 if (child_event
->parent
) {
6320 sync_child_event(child_event
, child
);
6321 free_event(child_event
);
6325 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6327 struct perf_event
*child_event
, *tmp
;
6328 struct perf_event_context
*child_ctx
;
6329 unsigned long flags
;
6331 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6332 perf_event_task(child
, NULL
, 0);
6336 local_irq_save(flags
);
6338 * We can't reschedule here because interrupts are disabled,
6339 * and either child is current or it is a task that can't be
6340 * scheduled, so we are now safe from rescheduling changing
6343 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6346 * Take the context lock here so that if find_get_context is
6347 * reading child->perf_event_ctxp, we wait until it has
6348 * incremented the context's refcount before we do put_ctx below.
6350 raw_spin_lock(&child_ctx
->lock
);
6351 task_ctx_sched_out(child_ctx
);
6352 child
->perf_event_ctxp
[ctxn
] = NULL
;
6354 * If this context is a clone; unclone it so it can't get
6355 * swapped to another process while we're removing all
6356 * the events from it.
6358 unclone_ctx(child_ctx
);
6359 update_context_time(child_ctx
);
6360 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6363 * Report the task dead after unscheduling the events so that we
6364 * won't get any samples after PERF_RECORD_EXIT. We can however still
6365 * get a few PERF_RECORD_READ events.
6367 perf_event_task(child
, child_ctx
, 0);
6370 * We can recurse on the same lock type through:
6372 * __perf_event_exit_task()
6373 * sync_child_event()
6374 * fput(parent_event->filp)
6376 * mutex_lock(&ctx->mutex)
6378 * But since its the parent context it won't be the same instance.
6380 mutex_lock(&child_ctx
->mutex
);
6383 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6385 __perf_event_exit_task(child_event
, child_ctx
, child
);
6387 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6389 __perf_event_exit_task(child_event
, child_ctx
, child
);
6392 * If the last event was a group event, it will have appended all
6393 * its siblings to the list, but we obtained 'tmp' before that which
6394 * will still point to the list head terminating the iteration.
6396 if (!list_empty(&child_ctx
->pinned_groups
) ||
6397 !list_empty(&child_ctx
->flexible_groups
))
6400 mutex_unlock(&child_ctx
->mutex
);
6406 * When a child task exits, feed back event values to parent events.
6408 void perf_event_exit_task(struct task_struct
*child
)
6410 struct perf_event
*event
, *tmp
;
6413 mutex_lock(&child
->perf_event_mutex
);
6414 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6416 list_del_init(&event
->owner_entry
);
6419 * Ensure the list deletion is visible before we clear
6420 * the owner, closes a race against perf_release() where
6421 * we need to serialize on the owner->perf_event_mutex.
6424 event
->owner
= NULL
;
6426 mutex_unlock(&child
->perf_event_mutex
);
6428 for_each_task_context_nr(ctxn
)
6429 perf_event_exit_task_context(child
, ctxn
);
6432 static void perf_free_event(struct perf_event
*event
,
6433 struct perf_event_context
*ctx
)
6435 struct perf_event
*parent
= event
->parent
;
6437 if (WARN_ON_ONCE(!parent
))
6440 mutex_lock(&parent
->child_mutex
);
6441 list_del_init(&event
->child_list
);
6442 mutex_unlock(&parent
->child_mutex
);
6446 perf_group_detach(event
);
6447 list_del_event(event
, ctx
);
6452 * free an unexposed, unused context as created by inheritance by
6453 * perf_event_init_task below, used by fork() in case of fail.
6455 void perf_event_free_task(struct task_struct
*task
)
6457 struct perf_event_context
*ctx
;
6458 struct perf_event
*event
, *tmp
;
6461 for_each_task_context_nr(ctxn
) {
6462 ctx
= task
->perf_event_ctxp
[ctxn
];
6466 mutex_lock(&ctx
->mutex
);
6468 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6470 perf_free_event(event
, ctx
);
6472 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6474 perf_free_event(event
, ctx
);
6476 if (!list_empty(&ctx
->pinned_groups
) ||
6477 !list_empty(&ctx
->flexible_groups
))
6480 mutex_unlock(&ctx
->mutex
);
6486 void perf_event_delayed_put(struct task_struct
*task
)
6490 for_each_task_context_nr(ctxn
)
6491 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6495 * inherit a event from parent task to child task:
6497 static struct perf_event
*
6498 inherit_event(struct perf_event
*parent_event
,
6499 struct task_struct
*parent
,
6500 struct perf_event_context
*parent_ctx
,
6501 struct task_struct
*child
,
6502 struct perf_event
*group_leader
,
6503 struct perf_event_context
*child_ctx
)
6505 struct perf_event
*child_event
;
6506 unsigned long flags
;
6509 * Instead of creating recursive hierarchies of events,
6510 * we link inherited events back to the original parent,
6511 * which has a filp for sure, which we use as the reference
6514 if (parent_event
->parent
)
6515 parent_event
= parent_event
->parent
;
6517 child_event
= perf_event_alloc(&parent_event
->attr
,
6520 group_leader
, parent_event
,
6522 if (IS_ERR(child_event
))
6527 * Make the child state follow the state of the parent event,
6528 * not its attr.disabled bit. We hold the parent's mutex,
6529 * so we won't race with perf_event_{en, dis}able_family.
6531 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6532 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6534 child_event
->state
= PERF_EVENT_STATE_OFF
;
6536 if (parent_event
->attr
.freq
) {
6537 u64 sample_period
= parent_event
->hw
.sample_period
;
6538 struct hw_perf_event
*hwc
= &child_event
->hw
;
6540 hwc
->sample_period
= sample_period
;
6541 hwc
->last_period
= sample_period
;
6543 local64_set(&hwc
->period_left
, sample_period
);
6546 child_event
->ctx
= child_ctx
;
6547 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6548 child_event
->overflow_handler_context
6549 = parent_event
->overflow_handler_context
;
6552 * Precalculate sample_data sizes
6554 perf_event__header_size(child_event
);
6555 perf_event__id_header_size(child_event
);
6558 * Link it up in the child's context:
6560 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6561 add_event_to_ctx(child_event
, child_ctx
);
6562 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6565 * Get a reference to the parent filp - we will fput it
6566 * when the child event exits. This is safe to do because
6567 * we are in the parent and we know that the filp still
6568 * exists and has a nonzero count:
6570 atomic_long_inc(&parent_event
->filp
->f_count
);
6573 * Link this into the parent event's child list
6575 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6576 mutex_lock(&parent_event
->child_mutex
);
6577 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
6578 mutex_unlock(&parent_event
->child_mutex
);
6583 static int inherit_group(struct perf_event
*parent_event
,
6584 struct task_struct
*parent
,
6585 struct perf_event_context
*parent_ctx
,
6586 struct task_struct
*child
,
6587 struct perf_event_context
*child_ctx
)
6589 struct perf_event
*leader
;
6590 struct perf_event
*sub
;
6591 struct perf_event
*child_ctr
;
6593 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
6594 child
, NULL
, child_ctx
);
6596 return PTR_ERR(leader
);
6597 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
6598 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
6599 child
, leader
, child_ctx
);
6600 if (IS_ERR(child_ctr
))
6601 return PTR_ERR(child_ctr
);
6607 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
6608 struct perf_event_context
*parent_ctx
,
6609 struct task_struct
*child
, int ctxn
,
6613 struct perf_event_context
*child_ctx
;
6615 if (!event
->attr
.inherit
) {
6620 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6623 * This is executed from the parent task context, so
6624 * inherit events that have been marked for cloning.
6625 * First allocate and initialize a context for the
6629 child_ctx
= alloc_perf_context(event
->pmu
, child
);
6633 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
6636 ret
= inherit_group(event
, parent
, parent_ctx
,
6646 * Initialize the perf_event context in task_struct
6648 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
6650 struct perf_event_context
*child_ctx
, *parent_ctx
;
6651 struct perf_event_context
*cloned_ctx
;
6652 struct perf_event
*event
;
6653 struct task_struct
*parent
= current
;
6654 int inherited_all
= 1;
6655 unsigned long flags
;
6658 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
6662 * If the parent's context is a clone, pin it so it won't get
6665 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
6668 * No need to check if parent_ctx != NULL here; since we saw
6669 * it non-NULL earlier, the only reason for it to become NULL
6670 * is if we exit, and since we're currently in the middle of
6671 * a fork we can't be exiting at the same time.
6675 * Lock the parent list. No need to lock the child - not PID
6676 * hashed yet and not running, so nobody can access it.
6678 mutex_lock(&parent_ctx
->mutex
);
6681 * We dont have to disable NMIs - we are only looking at
6682 * the list, not manipulating it:
6684 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
6685 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6686 child
, ctxn
, &inherited_all
);
6692 * We can't hold ctx->lock when iterating the ->flexible_group list due
6693 * to allocations, but we need to prevent rotation because
6694 * rotate_ctx() will change the list from interrupt context.
6696 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6697 parent_ctx
->rotate_disable
= 1;
6698 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6700 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
6701 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6702 child
, ctxn
, &inherited_all
);
6707 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6708 parent_ctx
->rotate_disable
= 0;
6710 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6712 if (child_ctx
&& inherited_all
) {
6714 * Mark the child context as a clone of the parent
6715 * context, or of whatever the parent is a clone of.
6717 * Note that if the parent is a clone, the holding of
6718 * parent_ctx->lock avoids it from being uncloned.
6720 cloned_ctx
= parent_ctx
->parent_ctx
;
6722 child_ctx
->parent_ctx
= cloned_ctx
;
6723 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
6725 child_ctx
->parent_ctx
= parent_ctx
;
6726 child_ctx
->parent_gen
= parent_ctx
->generation
;
6728 get_ctx(child_ctx
->parent_ctx
);
6731 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6732 mutex_unlock(&parent_ctx
->mutex
);
6734 perf_unpin_context(parent_ctx
);
6735 put_ctx(parent_ctx
);
6741 * Initialize the perf_event context in task_struct
6743 int perf_event_init_task(struct task_struct
*child
)
6747 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
6748 mutex_init(&child
->perf_event_mutex
);
6749 INIT_LIST_HEAD(&child
->perf_event_list
);
6751 for_each_task_context_nr(ctxn
) {
6752 ret
= perf_event_init_context(child
, ctxn
);
6760 static void __init
perf_event_init_all_cpus(void)
6762 struct swevent_htable
*swhash
;
6765 for_each_possible_cpu(cpu
) {
6766 swhash
= &per_cpu(swevent_htable
, cpu
);
6767 mutex_init(&swhash
->hlist_mutex
);
6768 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
6772 static void __cpuinit
perf_event_init_cpu(int cpu
)
6774 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6776 mutex_lock(&swhash
->hlist_mutex
);
6777 if (swhash
->hlist_refcount
> 0) {
6778 struct swevent_hlist
*hlist
;
6780 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
6782 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6784 mutex_unlock(&swhash
->hlist_mutex
);
6787 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
6788 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
6790 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6792 WARN_ON(!irqs_disabled());
6794 list_del_init(&cpuctx
->rotation_list
);
6797 static void __perf_event_exit_context(void *__info
)
6799 struct perf_event_context
*ctx
= __info
;
6800 struct perf_event
*event
, *tmp
;
6802 perf_pmu_rotate_stop(ctx
->pmu
);
6804 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
6805 __perf_remove_from_context(event
);
6806 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
6807 __perf_remove_from_context(event
);
6810 static void perf_event_exit_cpu_context(int cpu
)
6812 struct perf_event_context
*ctx
;
6816 idx
= srcu_read_lock(&pmus_srcu
);
6817 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6818 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
6820 mutex_lock(&ctx
->mutex
);
6821 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
6822 mutex_unlock(&ctx
->mutex
);
6824 srcu_read_unlock(&pmus_srcu
, idx
);
6827 static void perf_event_exit_cpu(int cpu
)
6829 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6831 mutex_lock(&swhash
->hlist_mutex
);
6832 swevent_hlist_release(swhash
);
6833 mutex_unlock(&swhash
->hlist_mutex
);
6835 perf_event_exit_cpu_context(cpu
);
6838 static inline void perf_event_exit_cpu(int cpu
) { }
6842 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
6846 for_each_online_cpu(cpu
)
6847 perf_event_exit_cpu(cpu
);
6853 * Run the perf reboot notifier at the very last possible moment so that
6854 * the generic watchdog code runs as long as possible.
6856 static struct notifier_block perf_reboot_notifier
= {
6857 .notifier_call
= perf_reboot
,
6858 .priority
= INT_MIN
,
6861 static int __cpuinit
6862 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
6864 unsigned int cpu
= (long)hcpu
;
6866 switch (action
& ~CPU_TASKS_FROZEN
) {
6868 case CPU_UP_PREPARE
:
6869 case CPU_DOWN_FAILED
:
6870 perf_event_init_cpu(cpu
);
6873 case CPU_UP_CANCELED
:
6874 case CPU_DOWN_PREPARE
:
6875 perf_event_exit_cpu(cpu
);
6885 void __init
perf_event_init(void)
6891 perf_event_init_all_cpus();
6892 init_srcu_struct(&pmus_srcu
);
6893 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
6894 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
6895 perf_pmu_register(&perf_task_clock
, NULL
, -1);
6897 perf_cpu_notifier(perf_cpu_notify
);
6898 register_reboot_notifier(&perf_reboot_notifier
);
6900 ret
= init_hw_breakpoint();
6901 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
6903 /* do not patch jump label more than once per second */
6904 jump_label_rate_limit(&perf_sched_events
, HZ
);
6907 static int __init
perf_event_sysfs_init(void)
6912 mutex_lock(&pmus_lock
);
6914 ret
= bus_register(&pmu_bus
);
6918 list_for_each_entry(pmu
, &pmus
, entry
) {
6919 if (!pmu
->name
|| pmu
->type
< 0)
6922 ret
= pmu_dev_alloc(pmu
);
6923 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
6925 pmu_bus_running
= 1;
6929 mutex_unlock(&pmus_lock
);
6933 device_initcall(perf_event_sysfs_init
);
6935 #ifdef CONFIG_CGROUP_PERF
6936 static struct cgroup_subsys_state
*perf_cgroup_create(
6937 struct cgroup_subsys
*ss
, struct cgroup
*cont
)
6939 struct perf_cgroup
*jc
;
6941 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
6943 return ERR_PTR(-ENOMEM
);
6945 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
6948 return ERR_PTR(-ENOMEM
);
6954 static void perf_cgroup_destroy(struct cgroup_subsys
*ss
,
6955 struct cgroup
*cont
)
6957 struct perf_cgroup
*jc
;
6958 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
6959 struct perf_cgroup
, css
);
6960 free_percpu(jc
->info
);
6964 static int __perf_cgroup_move(void *info
)
6966 struct task_struct
*task
= info
;
6967 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
6971 static void perf_cgroup_attach(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
6972 struct cgroup_taskset
*tset
)
6974 struct task_struct
*task
;
6976 cgroup_taskset_for_each(task
, cgrp
, tset
)
6977 task_function_call(task
, __perf_cgroup_move
, task
);
6980 static void perf_cgroup_exit(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
6981 struct cgroup
*old_cgrp
, struct task_struct
*task
)
6984 * cgroup_exit() is called in the copy_process() failure path.
6985 * Ignore this case since the task hasn't ran yet, this avoids
6986 * trying to poke a half freed task state from generic code.
6988 if (!(task
->flags
& PF_EXITING
))
6991 task_function_call(task
, __perf_cgroup_move
, task
);
6994 struct cgroup_subsys perf_subsys
= {
6995 .name
= "perf_event",
6996 .subsys_id
= perf_subsys_id
,
6997 .create
= perf_cgroup_create
,
6998 .destroy
= perf_cgroup_destroy
,
6999 .exit
= perf_cgroup_exit
,
7000 .attach
= perf_cgroup_attach
,
7002 #endif /* CONFIG_CGROUP_PERF */