2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/sysfs.h>
22 #include <linux/dcache.h>
23 #include <linux/percpu.h>
24 #include <linux/ptrace.h>
25 #include <linux/reboot.h>
26 #include <linux/vmstat.h>
27 #include <linux/device.h>
28 #include <linux/export.h>
29 #include <linux/vmalloc.h>
30 #include <linux/hardirq.h>
31 #include <linux/rculist.h>
32 #include <linux/uaccess.h>
33 #include <linux/syscalls.h>
34 #include <linux/anon_inodes.h>
35 #include <linux/kernel_stat.h>
36 #include <linux/perf_event.h>
37 #include <linux/ftrace_event.h>
38 #include <linux/hw_breakpoint.h>
42 #include <asm/irq_regs.h>
44 struct remote_function_call
{
45 struct task_struct
*p
;
46 int (*func
)(void *info
);
51 static void remote_function(void *data
)
53 struct remote_function_call
*tfc
= data
;
54 struct task_struct
*p
= tfc
->p
;
58 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
62 tfc
->ret
= tfc
->func(tfc
->info
);
66 * task_function_call - call a function on the cpu on which a task runs
67 * @p: the task to evaluate
68 * @func: the function to be called
69 * @info: the function call argument
71 * Calls the function @func when the task is currently running. This might
72 * be on the current CPU, which just calls the function directly
74 * returns: @func return value, or
75 * -ESRCH - when the process isn't running
76 * -EAGAIN - when the process moved away
79 task_function_call(struct task_struct
*p
, int (*func
) (void *info
), void *info
)
81 struct remote_function_call data
= {
85 .ret
= -ESRCH
, /* No such (running) process */
89 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
95 * cpu_function_call - call a function on the cpu
96 * @func: the function to be called
97 * @info: the function call argument
99 * Calls the function @func on the remote cpu.
101 * returns: @func return value or -ENXIO when the cpu is offline
103 static int cpu_function_call(int cpu
, int (*func
) (void *info
), void *info
)
105 struct remote_function_call data
= {
109 .ret
= -ENXIO
, /* No such CPU */
112 smp_call_function_single(cpu
, remote_function
, &data
, 1);
117 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
118 PERF_FLAG_FD_OUTPUT |\
119 PERF_FLAG_PID_CGROUP)
122 EVENT_FLEXIBLE
= 0x1,
124 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
128 * perf_sched_events : >0 events exist
129 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
131 struct jump_label_key perf_sched_events __read_mostly
;
132 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
134 static atomic_t nr_mmap_events __read_mostly
;
135 static atomic_t nr_comm_events __read_mostly
;
136 static atomic_t nr_task_events __read_mostly
;
138 static LIST_HEAD(pmus
);
139 static DEFINE_MUTEX(pmus_lock
);
140 static struct srcu_struct pmus_srcu
;
143 * perf event paranoia level:
144 * -1 - not paranoid at all
145 * 0 - disallow raw tracepoint access for unpriv
146 * 1 - disallow cpu events for unpriv
147 * 2 - disallow kernel profiling for unpriv
149 int sysctl_perf_event_paranoid __read_mostly
= 1;
151 /* Minimum for 512 kiB + 1 user control page */
152 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
155 * max perf event sample rate
157 #define DEFAULT_MAX_SAMPLE_RATE 100000
158 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
159 static int max_samples_per_tick __read_mostly
=
160 DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
162 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
163 void __user
*buffer
, size_t *lenp
,
166 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
171 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
176 static atomic64_t perf_event_id
;
178 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
179 enum event_type_t event_type
);
181 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
182 enum event_type_t event_type
,
183 struct task_struct
*task
);
185 static void update_context_time(struct perf_event_context
*ctx
);
186 static u64
perf_event_time(struct perf_event
*event
);
188 static void ring_buffer_attach(struct perf_event
*event
,
189 struct ring_buffer
*rb
);
191 void __weak
perf_event_print_debug(void) { }
193 extern __weak
const char *perf_pmu_name(void)
198 static inline u64
perf_clock(void)
200 return local_clock();
203 static inline struct perf_cpu_context
*
204 __get_cpu_context(struct perf_event_context
*ctx
)
206 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
209 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
210 struct perf_event_context
*ctx
)
212 raw_spin_lock(&cpuctx
->ctx
.lock
);
214 raw_spin_lock(&ctx
->lock
);
217 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
218 struct perf_event_context
*ctx
)
221 raw_spin_unlock(&ctx
->lock
);
222 raw_spin_unlock(&cpuctx
->ctx
.lock
);
225 #ifdef CONFIG_CGROUP_PERF
228 * Must ensure cgroup is pinned (css_get) before calling
229 * this function. In other words, we cannot call this function
230 * if there is no cgroup event for the current CPU context.
232 static inline struct perf_cgroup
*
233 perf_cgroup_from_task(struct task_struct
*task
)
235 return container_of(task_subsys_state(task
, perf_subsys_id
),
236 struct perf_cgroup
, css
);
240 perf_cgroup_match(struct perf_event
*event
)
242 struct perf_event_context
*ctx
= event
->ctx
;
243 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
245 return !event
->cgrp
|| event
->cgrp
== cpuctx
->cgrp
;
248 static inline void perf_get_cgroup(struct perf_event
*event
)
250 css_get(&event
->cgrp
->css
);
253 static inline void perf_put_cgroup(struct perf_event
*event
)
255 css_put(&event
->cgrp
->css
);
258 static inline void perf_detach_cgroup(struct perf_event
*event
)
260 perf_put_cgroup(event
);
264 static inline int is_cgroup_event(struct perf_event
*event
)
266 return event
->cgrp
!= NULL
;
269 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
271 struct perf_cgroup_info
*t
;
273 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
277 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
279 struct perf_cgroup_info
*info
;
284 info
= this_cpu_ptr(cgrp
->info
);
286 info
->time
+= now
- info
->timestamp
;
287 info
->timestamp
= now
;
290 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
292 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
294 __update_cgrp_time(cgrp_out
);
297 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
299 struct perf_cgroup
*cgrp
;
302 * ensure we access cgroup data only when needed and
303 * when we know the cgroup is pinned (css_get)
305 if (!is_cgroup_event(event
))
308 cgrp
= perf_cgroup_from_task(current
);
310 * Do not update time when cgroup is not active
312 if (cgrp
== event
->cgrp
)
313 __update_cgrp_time(event
->cgrp
);
317 perf_cgroup_set_timestamp(struct task_struct
*task
,
318 struct perf_event_context
*ctx
)
320 struct perf_cgroup
*cgrp
;
321 struct perf_cgroup_info
*info
;
324 * ctx->lock held by caller
325 * ensure we do not access cgroup data
326 * unless we have the cgroup pinned (css_get)
328 if (!task
|| !ctx
->nr_cgroups
)
331 cgrp
= perf_cgroup_from_task(task
);
332 info
= this_cpu_ptr(cgrp
->info
);
333 info
->timestamp
= ctx
->timestamp
;
336 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
337 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
340 * reschedule events based on the cgroup constraint of task.
342 * mode SWOUT : schedule out everything
343 * mode SWIN : schedule in based on cgroup for next
345 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
347 struct perf_cpu_context
*cpuctx
;
352 * disable interrupts to avoid geting nr_cgroup
353 * changes via __perf_event_disable(). Also
356 local_irq_save(flags
);
359 * we reschedule only in the presence of cgroup
360 * constrained events.
364 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
365 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
368 * perf_cgroup_events says at least one
369 * context on this CPU has cgroup events.
371 * ctx->nr_cgroups reports the number of cgroup
372 * events for a context.
374 if (cpuctx
->ctx
.nr_cgroups
> 0) {
375 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
376 perf_pmu_disable(cpuctx
->ctx
.pmu
);
378 if (mode
& PERF_CGROUP_SWOUT
) {
379 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
381 * must not be done before ctxswout due
382 * to event_filter_match() in event_sched_out()
387 if (mode
& PERF_CGROUP_SWIN
) {
388 WARN_ON_ONCE(cpuctx
->cgrp
);
389 /* set cgrp before ctxsw in to
390 * allow event_filter_match() to not
391 * have to pass task around
393 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
394 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
396 perf_pmu_enable(cpuctx
->ctx
.pmu
);
397 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
403 local_irq_restore(flags
);
406 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
407 struct task_struct
*next
)
409 struct perf_cgroup
*cgrp1
;
410 struct perf_cgroup
*cgrp2
= NULL
;
413 * we come here when we know perf_cgroup_events > 0
415 cgrp1
= perf_cgroup_from_task(task
);
418 * next is NULL when called from perf_event_enable_on_exec()
419 * that will systematically cause a cgroup_switch()
422 cgrp2
= perf_cgroup_from_task(next
);
425 * only schedule out current cgroup events if we know
426 * that we are switching to a different cgroup. Otherwise,
427 * do no touch the cgroup events.
430 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
433 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
434 struct task_struct
*task
)
436 struct perf_cgroup
*cgrp1
;
437 struct perf_cgroup
*cgrp2
= NULL
;
440 * we come here when we know perf_cgroup_events > 0
442 cgrp1
= perf_cgroup_from_task(task
);
444 /* prev can never be NULL */
445 cgrp2
= perf_cgroup_from_task(prev
);
448 * only need to schedule in cgroup events if we are changing
449 * cgroup during ctxsw. Cgroup events were not scheduled
450 * out of ctxsw out if that was not the case.
453 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
456 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
457 struct perf_event_attr
*attr
,
458 struct perf_event
*group_leader
)
460 struct perf_cgroup
*cgrp
;
461 struct cgroup_subsys_state
*css
;
463 int ret
= 0, fput_needed
;
465 file
= fget_light(fd
, &fput_needed
);
469 css
= cgroup_css_from_dir(file
, perf_subsys_id
);
475 cgrp
= container_of(css
, struct perf_cgroup
, css
);
478 /* must be done before we fput() the file */
479 perf_get_cgroup(event
);
482 * all events in a group must monitor
483 * the same cgroup because a task belongs
484 * to only one perf cgroup at a time
486 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
487 perf_detach_cgroup(event
);
491 fput_light(file
, fput_needed
);
496 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
498 struct perf_cgroup_info
*t
;
499 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
500 event
->shadow_ctx_time
= now
- t
->timestamp
;
504 perf_cgroup_defer_enabled(struct perf_event
*event
)
507 * when the current task's perf cgroup does not match
508 * the event's, we need to remember to call the
509 * perf_mark_enable() function the first time a task with
510 * a matching perf cgroup is scheduled in.
512 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
513 event
->cgrp_defer_enabled
= 1;
517 perf_cgroup_mark_enabled(struct perf_event
*event
,
518 struct perf_event_context
*ctx
)
520 struct perf_event
*sub
;
521 u64 tstamp
= perf_event_time(event
);
523 if (!event
->cgrp_defer_enabled
)
526 event
->cgrp_defer_enabled
= 0;
528 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
529 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
530 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
531 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
532 sub
->cgrp_defer_enabled
= 0;
536 #else /* !CONFIG_CGROUP_PERF */
539 perf_cgroup_match(struct perf_event
*event
)
544 static inline void perf_detach_cgroup(struct perf_event
*event
)
547 static inline int is_cgroup_event(struct perf_event
*event
)
552 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
557 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
561 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
565 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
566 struct task_struct
*next
)
570 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
571 struct task_struct
*task
)
575 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
576 struct perf_event_attr
*attr
,
577 struct perf_event
*group_leader
)
583 perf_cgroup_set_timestamp(struct task_struct
*task
,
584 struct perf_event_context
*ctx
)
589 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
594 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
598 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
604 perf_cgroup_defer_enabled(struct perf_event
*event
)
609 perf_cgroup_mark_enabled(struct perf_event
*event
,
610 struct perf_event_context
*ctx
)
615 void perf_pmu_disable(struct pmu
*pmu
)
617 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
619 pmu
->pmu_disable(pmu
);
622 void perf_pmu_enable(struct pmu
*pmu
)
624 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
626 pmu
->pmu_enable(pmu
);
629 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
632 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
633 * because they're strictly cpu affine and rotate_start is called with IRQs
634 * disabled, while rotate_context is called from IRQ context.
636 static void perf_pmu_rotate_start(struct pmu
*pmu
)
638 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
639 struct list_head
*head
= &__get_cpu_var(rotation_list
);
641 WARN_ON(!irqs_disabled());
643 if (list_empty(&cpuctx
->rotation_list
))
644 list_add(&cpuctx
->rotation_list
, head
);
647 static void get_ctx(struct perf_event_context
*ctx
)
649 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
652 static void put_ctx(struct perf_event_context
*ctx
)
654 if (atomic_dec_and_test(&ctx
->refcount
)) {
656 put_ctx(ctx
->parent_ctx
);
658 put_task_struct(ctx
->task
);
659 kfree_rcu(ctx
, rcu_head
);
663 static void unclone_ctx(struct perf_event_context
*ctx
)
665 if (ctx
->parent_ctx
) {
666 put_ctx(ctx
->parent_ctx
);
667 ctx
->parent_ctx
= NULL
;
671 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
674 * only top level events have the pid namespace they were created in
677 event
= event
->parent
;
679 return task_tgid_nr_ns(p
, event
->ns
);
682 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
685 * only top level events have the pid namespace they were created in
688 event
= event
->parent
;
690 return task_pid_nr_ns(p
, event
->ns
);
694 * If we inherit events we want to return the parent event id
697 static u64
primary_event_id(struct perf_event
*event
)
702 id
= event
->parent
->id
;
708 * Get the perf_event_context for a task and lock it.
709 * This has to cope with with the fact that until it is locked,
710 * the context could get moved to another task.
712 static struct perf_event_context
*
713 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
715 struct perf_event_context
*ctx
;
719 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
722 * If this context is a clone of another, it might
723 * get swapped for another underneath us by
724 * perf_event_task_sched_out, though the
725 * rcu_read_lock() protects us from any context
726 * getting freed. Lock the context and check if it
727 * got swapped before we could get the lock, and retry
728 * if so. If we locked the right context, then it
729 * can't get swapped on us any more.
731 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
732 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
733 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
737 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
738 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
747 * Get the context for a task and increment its pin_count so it
748 * can't get swapped to another task. This also increments its
749 * reference count so that the context can't get freed.
751 static struct perf_event_context
*
752 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
754 struct perf_event_context
*ctx
;
757 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
760 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
765 static void perf_unpin_context(struct perf_event_context
*ctx
)
769 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
771 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
775 * Update the record of the current time in a context.
777 static void update_context_time(struct perf_event_context
*ctx
)
779 u64 now
= perf_clock();
781 ctx
->time
+= now
- ctx
->timestamp
;
782 ctx
->timestamp
= now
;
785 static u64
perf_event_time(struct perf_event
*event
)
787 struct perf_event_context
*ctx
= event
->ctx
;
789 if (is_cgroup_event(event
))
790 return perf_cgroup_event_time(event
);
792 return ctx
? ctx
->time
: 0;
796 * Update the total_time_enabled and total_time_running fields for a event.
797 * The caller of this function needs to hold the ctx->lock.
799 static void update_event_times(struct perf_event
*event
)
801 struct perf_event_context
*ctx
= event
->ctx
;
804 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
805 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
808 * in cgroup mode, time_enabled represents
809 * the time the event was enabled AND active
810 * tasks were in the monitored cgroup. This is
811 * independent of the activity of the context as
812 * there may be a mix of cgroup and non-cgroup events.
814 * That is why we treat cgroup events differently
817 if (is_cgroup_event(event
))
818 run_end
= perf_event_time(event
);
819 else if (ctx
->is_active
)
822 run_end
= event
->tstamp_stopped
;
824 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
826 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
827 run_end
= event
->tstamp_stopped
;
829 run_end
= perf_event_time(event
);
831 event
->total_time_running
= run_end
- event
->tstamp_running
;
836 * Update total_time_enabled and total_time_running for all events in a group.
838 static void update_group_times(struct perf_event
*leader
)
840 struct perf_event
*event
;
842 update_event_times(leader
);
843 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
844 update_event_times(event
);
847 static struct list_head
*
848 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
850 if (event
->attr
.pinned
)
851 return &ctx
->pinned_groups
;
853 return &ctx
->flexible_groups
;
857 * Add a event from the lists for its context.
858 * Must be called with ctx->mutex and ctx->lock held.
861 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
863 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
864 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
867 * If we're a stand alone event or group leader, we go to the context
868 * list, group events are kept attached to the group so that
869 * perf_group_detach can, at all times, locate all siblings.
871 if (event
->group_leader
== event
) {
872 struct list_head
*list
;
874 if (is_software_event(event
))
875 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
877 list
= ctx_group_list(event
, ctx
);
878 list_add_tail(&event
->group_entry
, list
);
881 if (is_cgroup_event(event
))
884 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
886 perf_pmu_rotate_start(ctx
->pmu
);
888 if (event
->attr
.inherit_stat
)
893 * Called at perf_event creation and when events are attached/detached from a
896 static void perf_event__read_size(struct perf_event
*event
)
898 int entry
= sizeof(u64
); /* value */
902 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
905 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
908 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
909 entry
+= sizeof(u64
);
911 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
912 nr
+= event
->group_leader
->nr_siblings
;
917 event
->read_size
= size
;
920 static void perf_event__header_size(struct perf_event
*event
)
922 struct perf_sample_data
*data
;
923 u64 sample_type
= event
->attr
.sample_type
;
926 perf_event__read_size(event
);
928 if (sample_type
& PERF_SAMPLE_IP
)
929 size
+= sizeof(data
->ip
);
931 if (sample_type
& PERF_SAMPLE_ADDR
)
932 size
+= sizeof(data
->addr
);
934 if (sample_type
& PERF_SAMPLE_PERIOD
)
935 size
+= sizeof(data
->period
);
937 if (sample_type
& PERF_SAMPLE_READ
)
938 size
+= event
->read_size
;
940 event
->header_size
= size
;
943 static void perf_event__id_header_size(struct perf_event
*event
)
945 struct perf_sample_data
*data
;
946 u64 sample_type
= event
->attr
.sample_type
;
949 if (sample_type
& PERF_SAMPLE_TID
)
950 size
+= sizeof(data
->tid_entry
);
952 if (sample_type
& PERF_SAMPLE_TIME
)
953 size
+= sizeof(data
->time
);
955 if (sample_type
& PERF_SAMPLE_ID
)
956 size
+= sizeof(data
->id
);
958 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
959 size
+= sizeof(data
->stream_id
);
961 if (sample_type
& PERF_SAMPLE_CPU
)
962 size
+= sizeof(data
->cpu_entry
);
964 event
->id_header_size
= size
;
967 static void perf_group_attach(struct perf_event
*event
)
969 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
972 * We can have double attach due to group movement in perf_event_open.
974 if (event
->attach_state
& PERF_ATTACH_GROUP
)
977 event
->attach_state
|= PERF_ATTACH_GROUP
;
979 if (group_leader
== event
)
982 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
983 !is_software_event(event
))
984 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
986 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
987 group_leader
->nr_siblings
++;
989 perf_event__header_size(group_leader
);
991 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
992 perf_event__header_size(pos
);
996 * Remove a event from the lists for its context.
997 * Must be called with ctx->mutex and ctx->lock held.
1000 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1002 struct perf_cpu_context
*cpuctx
;
1004 * We can have double detach due to exit/hot-unplug + close.
1006 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1009 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1011 if (is_cgroup_event(event
)) {
1013 cpuctx
= __get_cpu_context(ctx
);
1015 * if there are no more cgroup events
1016 * then cler cgrp to avoid stale pointer
1017 * in update_cgrp_time_from_cpuctx()
1019 if (!ctx
->nr_cgroups
)
1020 cpuctx
->cgrp
= NULL
;
1024 if (event
->attr
.inherit_stat
)
1027 list_del_rcu(&event
->event_entry
);
1029 if (event
->group_leader
== event
)
1030 list_del_init(&event
->group_entry
);
1032 update_group_times(event
);
1035 * If event was in error state, then keep it
1036 * that way, otherwise bogus counts will be
1037 * returned on read(). The only way to get out
1038 * of error state is by explicit re-enabling
1041 if (event
->state
> PERF_EVENT_STATE_OFF
)
1042 event
->state
= PERF_EVENT_STATE_OFF
;
1045 static void perf_group_detach(struct perf_event
*event
)
1047 struct perf_event
*sibling
, *tmp
;
1048 struct list_head
*list
= NULL
;
1051 * We can have double detach due to exit/hot-unplug + close.
1053 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1056 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1059 * If this is a sibling, remove it from its group.
1061 if (event
->group_leader
!= event
) {
1062 list_del_init(&event
->group_entry
);
1063 event
->group_leader
->nr_siblings
--;
1067 if (!list_empty(&event
->group_entry
))
1068 list
= &event
->group_entry
;
1071 * If this was a group event with sibling events then
1072 * upgrade the siblings to singleton events by adding them
1073 * to whatever list we are on.
1075 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1077 list_move_tail(&sibling
->group_entry
, list
);
1078 sibling
->group_leader
= sibling
;
1080 /* Inherit group flags from the previous leader */
1081 sibling
->group_flags
= event
->group_flags
;
1085 perf_event__header_size(event
->group_leader
);
1087 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1088 perf_event__header_size(tmp
);
1092 event_filter_match(struct perf_event
*event
)
1094 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1095 && perf_cgroup_match(event
);
1099 event_sched_out(struct perf_event
*event
,
1100 struct perf_cpu_context
*cpuctx
,
1101 struct perf_event_context
*ctx
)
1103 u64 tstamp
= perf_event_time(event
);
1106 * An event which could not be activated because of
1107 * filter mismatch still needs to have its timings
1108 * maintained, otherwise bogus information is return
1109 * via read() for time_enabled, time_running:
1111 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1112 && !event_filter_match(event
)) {
1113 delta
= tstamp
- event
->tstamp_stopped
;
1114 event
->tstamp_running
+= delta
;
1115 event
->tstamp_stopped
= tstamp
;
1118 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1121 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1122 if (event
->pending_disable
) {
1123 event
->pending_disable
= 0;
1124 event
->state
= PERF_EVENT_STATE_OFF
;
1126 event
->tstamp_stopped
= tstamp
;
1127 event
->pmu
->del(event
, 0);
1130 if (!is_software_event(event
))
1131 cpuctx
->active_oncpu
--;
1133 if (event
->attr
.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
);
2182 perf_event_sched_in(cpuctx
, ctx
, task
);
2185 cpuctx
->task_ctx
= ctx
;
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
->pinned_groups
, group_entry
) {
2501 ret
= event_enable_on_exec(event
, ctx
);
2506 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2507 ret
= event_enable_on_exec(event
, ctx
);
2513 * Unclone this context if we enabled any event.
2518 raw_spin_unlock(&ctx
->lock
);
2521 * Also calls ctxswin for cgroup events, if any:
2523 perf_event_context_sched_in(ctx
, ctx
->task
);
2525 local_irq_restore(flags
);
2529 * Cross CPU call to read the hardware event
2531 static void __perf_event_read(void *info
)
2533 struct perf_event
*event
= info
;
2534 struct perf_event_context
*ctx
= event
->ctx
;
2535 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2538 * If this is a task context, we need to check whether it is
2539 * the current task context of this cpu. If not it has been
2540 * scheduled out before the smp call arrived. In that case
2541 * event->count would have been updated to a recent sample
2542 * when the event was scheduled out.
2544 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
2547 raw_spin_lock(&ctx
->lock
);
2548 if (ctx
->is_active
) {
2549 update_context_time(ctx
);
2550 update_cgrp_time_from_event(event
);
2552 update_event_times(event
);
2553 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
2554 event
->pmu
->read(event
);
2555 raw_spin_unlock(&ctx
->lock
);
2558 static inline u64
perf_event_count(struct perf_event
*event
)
2560 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
2563 static u64
perf_event_read(struct perf_event
*event
)
2566 * If event is enabled and currently active on a CPU, update the
2567 * value in the event structure:
2569 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
2570 smp_call_function_single(event
->oncpu
,
2571 __perf_event_read
, event
, 1);
2572 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2573 struct perf_event_context
*ctx
= event
->ctx
;
2574 unsigned long flags
;
2576 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
2578 * may read while context is not active
2579 * (e.g., thread is blocked), in that case
2580 * we cannot update context time
2582 if (ctx
->is_active
) {
2583 update_context_time(ctx
);
2584 update_cgrp_time_from_event(event
);
2586 update_event_times(event
);
2587 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2590 return perf_event_count(event
);
2594 * Initialize the perf_event context in a task_struct:
2596 static void __perf_event_init_context(struct perf_event_context
*ctx
)
2598 raw_spin_lock_init(&ctx
->lock
);
2599 mutex_init(&ctx
->mutex
);
2600 INIT_LIST_HEAD(&ctx
->pinned_groups
);
2601 INIT_LIST_HEAD(&ctx
->flexible_groups
);
2602 INIT_LIST_HEAD(&ctx
->event_list
);
2603 atomic_set(&ctx
->refcount
, 1);
2606 static struct perf_event_context
*
2607 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
2609 struct perf_event_context
*ctx
;
2611 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
2615 __perf_event_init_context(ctx
);
2618 get_task_struct(task
);
2625 static struct task_struct
*
2626 find_lively_task_by_vpid(pid_t vpid
)
2628 struct task_struct
*task
;
2635 task
= find_task_by_vpid(vpid
);
2637 get_task_struct(task
);
2641 return ERR_PTR(-ESRCH
);
2643 /* Reuse ptrace permission checks for now. */
2645 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
2650 put_task_struct(task
);
2651 return ERR_PTR(err
);
2656 * Returns a matching context with refcount and pincount.
2658 static struct perf_event_context
*
2659 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
2661 struct perf_event_context
*ctx
;
2662 struct perf_cpu_context
*cpuctx
;
2663 unsigned long flags
;
2667 /* Must be root to operate on a CPU event: */
2668 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
2669 return ERR_PTR(-EACCES
);
2672 * We could be clever and allow to attach a event to an
2673 * offline CPU and activate it when the CPU comes up, but
2676 if (!cpu_online(cpu
))
2677 return ERR_PTR(-ENODEV
);
2679 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
2688 ctxn
= pmu
->task_ctx_nr
;
2693 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
2697 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
2699 ctx
= alloc_perf_context(pmu
, task
);
2705 mutex_lock(&task
->perf_event_mutex
);
2707 * If it has already passed perf_event_exit_task().
2708 * we must see PF_EXITING, it takes this mutex too.
2710 if (task
->flags
& PF_EXITING
)
2712 else if (task
->perf_event_ctxp
[ctxn
])
2717 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
2719 mutex_unlock(&task
->perf_event_mutex
);
2721 if (unlikely(err
)) {
2733 return ERR_PTR(err
);
2736 static void perf_event_free_filter(struct perf_event
*event
);
2738 static void free_event_rcu(struct rcu_head
*head
)
2740 struct perf_event
*event
;
2742 event
= container_of(head
, struct perf_event
, rcu_head
);
2744 put_pid_ns(event
->ns
);
2745 perf_event_free_filter(event
);
2749 static void ring_buffer_put(struct ring_buffer
*rb
);
2751 static void free_event(struct perf_event
*event
)
2753 irq_work_sync(&event
->pending
);
2755 if (!event
->parent
) {
2756 if (event
->attach_state
& PERF_ATTACH_TASK
)
2757 jump_label_dec(&perf_sched_events
);
2758 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
2759 atomic_dec(&nr_mmap_events
);
2760 if (event
->attr
.comm
)
2761 atomic_dec(&nr_comm_events
);
2762 if (event
->attr
.task
)
2763 atomic_dec(&nr_task_events
);
2764 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
2765 put_callchain_buffers();
2766 if (is_cgroup_event(event
)) {
2767 atomic_dec(&per_cpu(perf_cgroup_events
, event
->cpu
));
2768 jump_label_dec(&perf_sched_events
);
2773 ring_buffer_put(event
->rb
);
2777 if (is_cgroup_event(event
))
2778 perf_detach_cgroup(event
);
2781 event
->destroy(event
);
2784 put_ctx(event
->ctx
);
2786 call_rcu(&event
->rcu_head
, free_event_rcu
);
2789 int perf_event_release_kernel(struct perf_event
*event
)
2791 struct perf_event_context
*ctx
= event
->ctx
;
2793 WARN_ON_ONCE(ctx
->parent_ctx
);
2795 * There are two ways this annotation is useful:
2797 * 1) there is a lock recursion from perf_event_exit_task
2798 * see the comment there.
2800 * 2) there is a lock-inversion with mmap_sem through
2801 * perf_event_read_group(), which takes faults while
2802 * holding ctx->mutex, however this is called after
2803 * the last filedesc died, so there is no possibility
2804 * to trigger the AB-BA case.
2806 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
2807 raw_spin_lock_irq(&ctx
->lock
);
2808 perf_group_detach(event
);
2809 raw_spin_unlock_irq(&ctx
->lock
);
2810 perf_remove_from_context(event
);
2811 mutex_unlock(&ctx
->mutex
);
2817 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
2820 * Called when the last reference to the file is gone.
2822 static int perf_release(struct inode
*inode
, struct file
*file
)
2824 struct perf_event
*event
= file
->private_data
;
2825 struct task_struct
*owner
;
2827 file
->private_data
= NULL
;
2830 owner
= ACCESS_ONCE(event
->owner
);
2832 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
2833 * !owner it means the list deletion is complete and we can indeed
2834 * free this event, otherwise we need to serialize on
2835 * owner->perf_event_mutex.
2837 smp_read_barrier_depends();
2840 * Since delayed_put_task_struct() also drops the last
2841 * task reference we can safely take a new reference
2842 * while holding the rcu_read_lock().
2844 get_task_struct(owner
);
2849 mutex_lock(&owner
->perf_event_mutex
);
2851 * We have to re-check the event->owner field, if it is cleared
2852 * we raced with perf_event_exit_task(), acquiring the mutex
2853 * ensured they're done, and we can proceed with freeing the
2857 list_del_init(&event
->owner_entry
);
2858 mutex_unlock(&owner
->perf_event_mutex
);
2859 put_task_struct(owner
);
2862 return perf_event_release_kernel(event
);
2865 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
2867 struct perf_event
*child
;
2873 mutex_lock(&event
->child_mutex
);
2874 total
+= perf_event_read(event
);
2875 *enabled
+= event
->total_time_enabled
+
2876 atomic64_read(&event
->child_total_time_enabled
);
2877 *running
+= event
->total_time_running
+
2878 atomic64_read(&event
->child_total_time_running
);
2880 list_for_each_entry(child
, &event
->child_list
, child_list
) {
2881 total
+= perf_event_read(child
);
2882 *enabled
+= child
->total_time_enabled
;
2883 *running
+= child
->total_time_running
;
2885 mutex_unlock(&event
->child_mutex
);
2889 EXPORT_SYMBOL_GPL(perf_event_read_value
);
2891 static int perf_event_read_group(struct perf_event
*event
,
2892 u64 read_format
, char __user
*buf
)
2894 struct perf_event
*leader
= event
->group_leader
, *sub
;
2895 int n
= 0, size
= 0, ret
= -EFAULT
;
2896 struct perf_event_context
*ctx
= leader
->ctx
;
2898 u64 count
, enabled
, running
;
2900 mutex_lock(&ctx
->mutex
);
2901 count
= perf_event_read_value(leader
, &enabled
, &running
);
2903 values
[n
++] = 1 + leader
->nr_siblings
;
2904 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2905 values
[n
++] = enabled
;
2906 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2907 values
[n
++] = running
;
2908 values
[n
++] = count
;
2909 if (read_format
& PERF_FORMAT_ID
)
2910 values
[n
++] = primary_event_id(leader
);
2912 size
= n
* sizeof(u64
);
2914 if (copy_to_user(buf
, values
, size
))
2919 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
2922 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
2923 if (read_format
& PERF_FORMAT_ID
)
2924 values
[n
++] = primary_event_id(sub
);
2926 size
= n
* sizeof(u64
);
2928 if (copy_to_user(buf
+ ret
, values
, size
)) {
2936 mutex_unlock(&ctx
->mutex
);
2941 static int perf_event_read_one(struct perf_event
*event
,
2942 u64 read_format
, char __user
*buf
)
2944 u64 enabled
, running
;
2948 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
2949 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
2950 values
[n
++] = enabled
;
2951 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
2952 values
[n
++] = running
;
2953 if (read_format
& PERF_FORMAT_ID
)
2954 values
[n
++] = primary_event_id(event
);
2956 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
2959 return n
* sizeof(u64
);
2963 * Read the performance event - simple non blocking version for now
2966 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
2968 u64 read_format
= event
->attr
.read_format
;
2972 * Return end-of-file for a read on a event that is in
2973 * error state (i.e. because it was pinned but it couldn't be
2974 * scheduled on to the CPU at some point).
2976 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2979 if (count
< event
->read_size
)
2982 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
2983 if (read_format
& PERF_FORMAT_GROUP
)
2984 ret
= perf_event_read_group(event
, read_format
, buf
);
2986 ret
= perf_event_read_one(event
, read_format
, buf
);
2992 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
2994 struct perf_event
*event
= file
->private_data
;
2996 return perf_read_hw(event
, buf
, count
);
2999 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3001 struct perf_event
*event
= file
->private_data
;
3002 struct ring_buffer
*rb
;
3003 unsigned int events
= POLL_HUP
;
3006 * Race between perf_event_set_output() and perf_poll(): perf_poll()
3007 * grabs the rb reference but perf_event_set_output() overrides it.
3008 * Here is the timeline for two threads T1, T2:
3009 * t0: T1, rb = rcu_dereference(event->rb)
3010 * t1: T2, old_rb = event->rb
3011 * t2: T2, event->rb = new rb
3012 * t3: T2, ring_buffer_detach(old_rb)
3013 * t4: T1, ring_buffer_attach(rb1)
3014 * t5: T1, poll_wait(event->waitq)
3016 * To avoid this problem, we grab mmap_mutex in perf_poll()
3017 * thereby ensuring that the assignment of the new ring buffer
3018 * and the detachment of the old buffer appear atomic to perf_poll()
3020 mutex_lock(&event
->mmap_mutex
);
3023 rb
= rcu_dereference(event
->rb
);
3025 ring_buffer_attach(event
, rb
);
3026 events
= atomic_xchg(&rb
->poll
, 0);
3030 mutex_unlock(&event
->mmap_mutex
);
3032 poll_wait(file
, &event
->waitq
, wait
);
3037 static void perf_event_reset(struct perf_event
*event
)
3039 (void)perf_event_read(event
);
3040 local64_set(&event
->count
, 0);
3041 perf_event_update_userpage(event
);
3045 * Holding the top-level event's child_mutex means that any
3046 * descendant process that has inherited this event will block
3047 * in sync_child_event if it goes to exit, thus satisfying the
3048 * task existence requirements of perf_event_enable/disable.
3050 static void perf_event_for_each_child(struct perf_event
*event
,
3051 void (*func
)(struct perf_event
*))
3053 struct perf_event
*child
;
3055 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3056 mutex_lock(&event
->child_mutex
);
3058 list_for_each_entry(child
, &event
->child_list
, child_list
)
3060 mutex_unlock(&event
->child_mutex
);
3063 static void perf_event_for_each(struct perf_event
*event
,
3064 void (*func
)(struct perf_event
*))
3066 struct perf_event_context
*ctx
= event
->ctx
;
3067 struct perf_event
*sibling
;
3069 WARN_ON_ONCE(ctx
->parent_ctx
);
3070 mutex_lock(&ctx
->mutex
);
3071 event
= event
->group_leader
;
3073 perf_event_for_each_child(event
, func
);
3075 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3076 perf_event_for_each_child(event
, func
);
3077 mutex_unlock(&ctx
->mutex
);
3080 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3082 struct perf_event_context
*ctx
= event
->ctx
;
3086 if (!is_sampling_event(event
))
3089 if (copy_from_user(&value
, arg
, sizeof(value
)))
3095 raw_spin_lock_irq(&ctx
->lock
);
3096 if (event
->attr
.freq
) {
3097 if (value
> sysctl_perf_event_sample_rate
) {
3102 event
->attr
.sample_freq
= value
;
3104 event
->attr
.sample_period
= value
;
3105 event
->hw
.sample_period
= value
;
3108 raw_spin_unlock_irq(&ctx
->lock
);
3113 static const struct file_operations perf_fops
;
3115 static struct perf_event
*perf_fget_light(int fd
, int *fput_needed
)
3119 file
= fget_light(fd
, fput_needed
);
3121 return ERR_PTR(-EBADF
);
3123 if (file
->f_op
!= &perf_fops
) {
3124 fput_light(file
, *fput_needed
);
3126 return ERR_PTR(-EBADF
);
3129 return file
->private_data
;
3132 static int perf_event_set_output(struct perf_event
*event
,
3133 struct perf_event
*output_event
);
3134 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3136 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3138 struct perf_event
*event
= file
->private_data
;
3139 void (*func
)(struct perf_event
*);
3143 case PERF_EVENT_IOC_ENABLE
:
3144 func
= perf_event_enable
;
3146 case PERF_EVENT_IOC_DISABLE
:
3147 func
= perf_event_disable
;
3149 case PERF_EVENT_IOC_RESET
:
3150 func
= perf_event_reset
;
3153 case PERF_EVENT_IOC_REFRESH
:
3154 return perf_event_refresh(event
, arg
);
3156 case PERF_EVENT_IOC_PERIOD
:
3157 return perf_event_period(event
, (u64 __user
*)arg
);
3159 case PERF_EVENT_IOC_SET_OUTPUT
:
3161 struct perf_event
*output_event
= NULL
;
3162 int fput_needed
= 0;
3166 output_event
= perf_fget_light(arg
, &fput_needed
);
3167 if (IS_ERR(output_event
))
3168 return PTR_ERR(output_event
);
3171 ret
= perf_event_set_output(event
, output_event
);
3173 fput_light(output_event
->filp
, fput_needed
);
3178 case PERF_EVENT_IOC_SET_FILTER
:
3179 return perf_event_set_filter(event
, (void __user
*)arg
);
3185 if (flags
& PERF_IOC_FLAG_GROUP
)
3186 perf_event_for_each(event
, func
);
3188 perf_event_for_each_child(event
, func
);
3193 int perf_event_task_enable(void)
3195 struct perf_event
*event
;
3197 mutex_lock(¤t
->perf_event_mutex
);
3198 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3199 perf_event_for_each_child(event
, perf_event_enable
);
3200 mutex_unlock(¤t
->perf_event_mutex
);
3205 int perf_event_task_disable(void)
3207 struct perf_event
*event
;
3209 mutex_lock(¤t
->perf_event_mutex
);
3210 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3211 perf_event_for_each_child(event
, perf_event_disable
);
3212 mutex_unlock(¤t
->perf_event_mutex
);
3217 #ifndef PERF_EVENT_INDEX_OFFSET
3218 # define PERF_EVENT_INDEX_OFFSET 0
3221 static int perf_event_index(struct perf_event
*event
)
3223 if (event
->hw
.state
& PERF_HES_STOPPED
)
3226 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3229 return event
->hw
.idx
+ 1 - PERF_EVENT_INDEX_OFFSET
;
3232 static void calc_timer_values(struct perf_event
*event
,
3239 ctx_time
= event
->shadow_ctx_time
+ now
;
3240 *enabled
= ctx_time
- event
->tstamp_enabled
;
3241 *running
= ctx_time
- event
->tstamp_running
;
3245 * Callers need to ensure there can be no nesting of this function, otherwise
3246 * the seqlock logic goes bad. We can not serialize this because the arch
3247 * code calls this from NMI context.
3249 void perf_event_update_userpage(struct perf_event
*event
)
3251 struct perf_event_mmap_page
*userpg
;
3252 struct ring_buffer
*rb
;
3253 u64 enabled
, running
;
3257 * compute total_time_enabled, total_time_running
3258 * based on snapshot values taken when the event
3259 * was last scheduled in.
3261 * we cannot simply called update_context_time()
3262 * because of locking issue as we can be called in
3265 calc_timer_values(event
, &enabled
, &running
);
3266 rb
= rcu_dereference(event
->rb
);
3270 userpg
= rb
->user_page
;
3273 * Disable preemption so as to not let the corresponding user-space
3274 * spin too long if we get preempted.
3279 userpg
->index
= perf_event_index(event
);
3280 userpg
->offset
= perf_event_count(event
);
3281 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3282 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3284 userpg
->time_enabled
= enabled
+
3285 atomic64_read(&event
->child_total_time_enabled
);
3287 userpg
->time_running
= running
+
3288 atomic64_read(&event
->child_total_time_running
);
3297 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3299 struct perf_event
*event
= vma
->vm_file
->private_data
;
3300 struct ring_buffer
*rb
;
3301 int ret
= VM_FAULT_SIGBUS
;
3303 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3304 if (vmf
->pgoff
== 0)
3310 rb
= rcu_dereference(event
->rb
);
3314 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3317 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3321 get_page(vmf
->page
);
3322 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3323 vmf
->page
->index
= vmf
->pgoff
;
3332 static void ring_buffer_attach(struct perf_event
*event
,
3333 struct ring_buffer
*rb
)
3335 unsigned long flags
;
3337 if (!list_empty(&event
->rb_entry
))
3340 spin_lock_irqsave(&rb
->event_lock
, flags
);
3341 if (!list_empty(&event
->rb_entry
))
3344 list_add(&event
->rb_entry
, &rb
->event_list
);
3346 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3349 static void ring_buffer_detach(struct perf_event
*event
,
3350 struct ring_buffer
*rb
)
3352 unsigned long flags
;
3354 if (list_empty(&event
->rb_entry
))
3357 spin_lock_irqsave(&rb
->event_lock
, flags
);
3358 list_del_init(&event
->rb_entry
);
3359 wake_up_all(&event
->waitq
);
3360 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3363 static void ring_buffer_wakeup(struct perf_event
*event
)
3365 struct ring_buffer
*rb
;
3368 rb
= rcu_dereference(event
->rb
);
3369 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
3370 wake_up_all(&event
->waitq
);
3375 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3377 struct ring_buffer
*rb
;
3379 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3383 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3385 struct ring_buffer
*rb
;
3388 rb
= rcu_dereference(event
->rb
);
3390 if (!atomic_inc_not_zero(&rb
->refcount
))
3398 static void ring_buffer_put(struct ring_buffer
*rb
)
3400 struct perf_event
*event
, *n
;
3401 unsigned long flags
;
3403 if (!atomic_dec_and_test(&rb
->refcount
))
3406 spin_lock_irqsave(&rb
->event_lock
, flags
);
3407 list_for_each_entry_safe(event
, n
, &rb
->event_list
, rb_entry
) {
3408 list_del_init(&event
->rb_entry
);
3409 wake_up_all(&event
->waitq
);
3411 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3413 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3416 static void perf_mmap_open(struct vm_area_struct
*vma
)
3418 struct perf_event
*event
= vma
->vm_file
->private_data
;
3420 atomic_inc(&event
->mmap_count
);
3423 static void perf_mmap_close(struct vm_area_struct
*vma
)
3425 struct perf_event
*event
= vma
->vm_file
->private_data
;
3427 if (atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
)) {
3428 unsigned long size
= perf_data_size(event
->rb
);
3429 struct user_struct
*user
= event
->mmap_user
;
3430 struct ring_buffer
*rb
= event
->rb
;
3432 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &user
->locked_vm
);
3433 vma
->vm_mm
->pinned_vm
-= event
->mmap_locked
;
3434 rcu_assign_pointer(event
->rb
, NULL
);
3435 ring_buffer_detach(event
, rb
);
3436 mutex_unlock(&event
->mmap_mutex
);
3438 ring_buffer_put(rb
);
3443 static const struct vm_operations_struct perf_mmap_vmops
= {
3444 .open
= perf_mmap_open
,
3445 .close
= perf_mmap_close
,
3446 .fault
= perf_mmap_fault
,
3447 .page_mkwrite
= perf_mmap_fault
,
3450 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3452 struct perf_event
*event
= file
->private_data
;
3453 unsigned long user_locked
, user_lock_limit
;
3454 struct user_struct
*user
= current_user();
3455 unsigned long locked
, lock_limit
;
3456 struct ring_buffer
*rb
;
3457 unsigned long vma_size
;
3458 unsigned long nr_pages
;
3459 long user_extra
, extra
;
3460 int ret
= 0, flags
= 0;
3463 * Don't allow mmap() of inherited per-task counters. This would
3464 * create a performance issue due to all children writing to the
3467 if (event
->cpu
== -1 && event
->attr
.inherit
)
3470 if (!(vma
->vm_flags
& VM_SHARED
))
3473 vma_size
= vma
->vm_end
- vma
->vm_start
;
3474 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
3477 * If we have rb pages ensure they're a power-of-two number, so we
3478 * can do bitmasks instead of modulo.
3480 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
3483 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
3486 if (vma
->vm_pgoff
!= 0)
3489 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3490 mutex_lock(&event
->mmap_mutex
);
3492 if (event
->rb
->nr_pages
== nr_pages
)
3493 atomic_inc(&event
->rb
->refcount
);
3499 user_extra
= nr_pages
+ 1;
3500 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
3503 * Increase the limit linearly with more CPUs:
3505 user_lock_limit
*= num_online_cpus();
3507 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
3510 if (user_locked
> user_lock_limit
)
3511 extra
= user_locked
- user_lock_limit
;
3513 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
3514 lock_limit
>>= PAGE_SHIFT
;
3515 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
3517 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
3518 !capable(CAP_IPC_LOCK
)) {
3525 if (vma
->vm_flags
& VM_WRITE
)
3526 flags
|= RING_BUFFER_WRITABLE
;
3528 rb
= rb_alloc(nr_pages
,
3529 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
3536 rcu_assign_pointer(event
->rb
, rb
);
3538 atomic_long_add(user_extra
, &user
->locked_vm
);
3539 event
->mmap_locked
= extra
;
3540 event
->mmap_user
= get_current_user();
3541 vma
->vm_mm
->pinned_vm
+= event
->mmap_locked
;
3545 atomic_inc(&event
->mmap_count
);
3546 mutex_unlock(&event
->mmap_mutex
);
3548 vma
->vm_flags
|= VM_RESERVED
;
3549 vma
->vm_ops
= &perf_mmap_vmops
;
3554 static int perf_fasync(int fd
, struct file
*filp
, int on
)
3556 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
3557 struct perf_event
*event
= filp
->private_data
;
3560 mutex_lock(&inode
->i_mutex
);
3561 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
3562 mutex_unlock(&inode
->i_mutex
);
3570 static const struct file_operations perf_fops
= {
3571 .llseek
= no_llseek
,
3572 .release
= perf_release
,
3575 .unlocked_ioctl
= perf_ioctl
,
3576 .compat_ioctl
= perf_ioctl
,
3578 .fasync
= perf_fasync
,
3584 * If there's data, ensure we set the poll() state and publish everything
3585 * to user-space before waking everybody up.
3588 void perf_event_wakeup(struct perf_event
*event
)
3590 ring_buffer_wakeup(event
);
3592 if (event
->pending_kill
) {
3593 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
3594 event
->pending_kill
= 0;
3598 static void perf_pending_event(struct irq_work
*entry
)
3600 struct perf_event
*event
= container_of(entry
,
3601 struct perf_event
, pending
);
3603 if (event
->pending_disable
) {
3604 event
->pending_disable
= 0;
3605 __perf_event_disable(event
);
3608 if (event
->pending_wakeup
) {
3609 event
->pending_wakeup
= 0;
3610 perf_event_wakeup(event
);
3615 * We assume there is only KVM supporting the callbacks.
3616 * Later on, we might change it to a list if there is
3617 * another virtualization implementation supporting the callbacks.
3619 struct perf_guest_info_callbacks
*perf_guest_cbs
;
3621 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3623 perf_guest_cbs
= cbs
;
3626 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
3628 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
3630 perf_guest_cbs
= NULL
;
3633 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
3635 static void __perf_event_header__init_id(struct perf_event_header
*header
,
3636 struct perf_sample_data
*data
,
3637 struct perf_event
*event
)
3639 u64 sample_type
= event
->attr
.sample_type
;
3641 data
->type
= sample_type
;
3642 header
->size
+= event
->id_header_size
;
3644 if (sample_type
& PERF_SAMPLE_TID
) {
3645 /* namespace issues */
3646 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
3647 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
3650 if (sample_type
& PERF_SAMPLE_TIME
)
3651 data
->time
= perf_clock();
3653 if (sample_type
& PERF_SAMPLE_ID
)
3654 data
->id
= primary_event_id(event
);
3656 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3657 data
->stream_id
= event
->id
;
3659 if (sample_type
& PERF_SAMPLE_CPU
) {
3660 data
->cpu_entry
.cpu
= raw_smp_processor_id();
3661 data
->cpu_entry
.reserved
= 0;
3665 void perf_event_header__init_id(struct perf_event_header
*header
,
3666 struct perf_sample_data
*data
,
3667 struct perf_event
*event
)
3669 if (event
->attr
.sample_id_all
)
3670 __perf_event_header__init_id(header
, data
, event
);
3673 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
3674 struct perf_sample_data
*data
)
3676 u64 sample_type
= data
->type
;
3678 if (sample_type
& PERF_SAMPLE_TID
)
3679 perf_output_put(handle
, data
->tid_entry
);
3681 if (sample_type
& PERF_SAMPLE_TIME
)
3682 perf_output_put(handle
, data
->time
);
3684 if (sample_type
& PERF_SAMPLE_ID
)
3685 perf_output_put(handle
, data
->id
);
3687 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3688 perf_output_put(handle
, data
->stream_id
);
3690 if (sample_type
& PERF_SAMPLE_CPU
)
3691 perf_output_put(handle
, data
->cpu_entry
);
3694 void perf_event__output_id_sample(struct perf_event
*event
,
3695 struct perf_output_handle
*handle
,
3696 struct perf_sample_data
*sample
)
3698 if (event
->attr
.sample_id_all
)
3699 __perf_event__output_id_sample(handle
, sample
);
3702 static void perf_output_read_one(struct perf_output_handle
*handle
,
3703 struct perf_event
*event
,
3704 u64 enabled
, u64 running
)
3706 u64 read_format
= event
->attr
.read_format
;
3710 values
[n
++] = perf_event_count(event
);
3711 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3712 values
[n
++] = enabled
+
3713 atomic64_read(&event
->child_total_time_enabled
);
3715 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3716 values
[n
++] = running
+
3717 atomic64_read(&event
->child_total_time_running
);
3719 if (read_format
& PERF_FORMAT_ID
)
3720 values
[n
++] = primary_event_id(event
);
3722 __output_copy(handle
, values
, n
* sizeof(u64
));
3726 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
3728 static void perf_output_read_group(struct perf_output_handle
*handle
,
3729 struct perf_event
*event
,
3730 u64 enabled
, u64 running
)
3732 struct perf_event
*leader
= event
->group_leader
, *sub
;
3733 u64 read_format
= event
->attr
.read_format
;
3737 values
[n
++] = 1 + leader
->nr_siblings
;
3739 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3740 values
[n
++] = enabled
;
3742 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3743 values
[n
++] = running
;
3745 if (leader
!= event
)
3746 leader
->pmu
->read(leader
);
3748 values
[n
++] = perf_event_count(leader
);
3749 if (read_format
& PERF_FORMAT_ID
)
3750 values
[n
++] = primary_event_id(leader
);
3752 __output_copy(handle
, values
, n
* sizeof(u64
));
3754 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3758 sub
->pmu
->read(sub
);
3760 values
[n
++] = perf_event_count(sub
);
3761 if (read_format
& PERF_FORMAT_ID
)
3762 values
[n
++] = primary_event_id(sub
);
3764 __output_copy(handle
, values
, n
* sizeof(u64
));
3768 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
3769 PERF_FORMAT_TOTAL_TIME_RUNNING)
3771 static void perf_output_read(struct perf_output_handle
*handle
,
3772 struct perf_event
*event
)
3774 u64 enabled
= 0, running
= 0;
3775 u64 read_format
= event
->attr
.read_format
;
3778 * compute total_time_enabled, total_time_running
3779 * based on snapshot values taken when the event
3780 * was last scheduled in.
3782 * we cannot simply called update_context_time()
3783 * because of locking issue as we are called in
3786 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
3787 calc_timer_values(event
, &enabled
, &running
);
3789 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
3790 perf_output_read_group(handle
, event
, enabled
, running
);
3792 perf_output_read_one(handle
, event
, enabled
, running
);
3795 void perf_output_sample(struct perf_output_handle
*handle
,
3796 struct perf_event_header
*header
,
3797 struct perf_sample_data
*data
,
3798 struct perf_event
*event
)
3800 u64 sample_type
= data
->type
;
3802 perf_output_put(handle
, *header
);
3804 if (sample_type
& PERF_SAMPLE_IP
)
3805 perf_output_put(handle
, data
->ip
);
3807 if (sample_type
& PERF_SAMPLE_TID
)
3808 perf_output_put(handle
, data
->tid_entry
);
3810 if (sample_type
& PERF_SAMPLE_TIME
)
3811 perf_output_put(handle
, data
->time
);
3813 if (sample_type
& PERF_SAMPLE_ADDR
)
3814 perf_output_put(handle
, data
->addr
);
3816 if (sample_type
& PERF_SAMPLE_ID
)
3817 perf_output_put(handle
, data
->id
);
3819 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
3820 perf_output_put(handle
, data
->stream_id
);
3822 if (sample_type
& PERF_SAMPLE_CPU
)
3823 perf_output_put(handle
, data
->cpu_entry
);
3825 if (sample_type
& PERF_SAMPLE_PERIOD
)
3826 perf_output_put(handle
, data
->period
);
3828 if (sample_type
& PERF_SAMPLE_READ
)
3829 perf_output_read(handle
, event
);
3831 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3832 if (data
->callchain
) {
3835 if (data
->callchain
)
3836 size
+= data
->callchain
->nr
;
3838 size
*= sizeof(u64
);
3840 __output_copy(handle
, data
->callchain
, size
);
3843 perf_output_put(handle
, nr
);
3847 if (sample_type
& PERF_SAMPLE_RAW
) {
3849 perf_output_put(handle
, data
->raw
->size
);
3850 __output_copy(handle
, data
->raw
->data
,
3857 .size
= sizeof(u32
),
3860 perf_output_put(handle
, raw
);
3864 if (!event
->attr
.watermark
) {
3865 int wakeup_events
= event
->attr
.wakeup_events
;
3867 if (wakeup_events
) {
3868 struct ring_buffer
*rb
= handle
->rb
;
3869 int events
= local_inc_return(&rb
->events
);
3871 if (events
>= wakeup_events
) {
3872 local_sub(wakeup_events
, &rb
->events
);
3873 local_inc(&rb
->wakeup
);
3879 void perf_prepare_sample(struct perf_event_header
*header
,
3880 struct perf_sample_data
*data
,
3881 struct perf_event
*event
,
3882 struct pt_regs
*regs
)
3884 u64 sample_type
= event
->attr
.sample_type
;
3886 header
->type
= PERF_RECORD_SAMPLE
;
3887 header
->size
= sizeof(*header
) + event
->header_size
;
3890 header
->misc
|= perf_misc_flags(regs
);
3892 __perf_event_header__init_id(header
, data
, event
);
3894 if (sample_type
& PERF_SAMPLE_IP
)
3895 data
->ip
= perf_instruction_pointer(regs
);
3897 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
3900 data
->callchain
= perf_callchain(regs
);
3902 if (data
->callchain
)
3903 size
+= data
->callchain
->nr
;
3905 header
->size
+= size
* sizeof(u64
);
3908 if (sample_type
& PERF_SAMPLE_RAW
) {
3909 int size
= sizeof(u32
);
3912 size
+= data
->raw
->size
;
3914 size
+= sizeof(u32
);
3916 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
3917 header
->size
+= size
;
3921 static void perf_event_output(struct perf_event
*event
,
3922 struct perf_sample_data
*data
,
3923 struct pt_regs
*regs
)
3925 struct perf_output_handle handle
;
3926 struct perf_event_header header
;
3928 /* protect the callchain buffers */
3931 perf_prepare_sample(&header
, data
, event
, regs
);
3933 if (perf_output_begin(&handle
, event
, header
.size
))
3936 perf_output_sample(&handle
, &header
, data
, event
);
3938 perf_output_end(&handle
);
3948 struct perf_read_event
{
3949 struct perf_event_header header
;
3956 perf_event_read_event(struct perf_event
*event
,
3957 struct task_struct
*task
)
3959 struct perf_output_handle handle
;
3960 struct perf_sample_data sample
;
3961 struct perf_read_event read_event
= {
3963 .type
= PERF_RECORD_READ
,
3965 .size
= sizeof(read_event
) + event
->read_size
,
3967 .pid
= perf_event_pid(event
, task
),
3968 .tid
= perf_event_tid(event
, task
),
3972 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
3973 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
3977 perf_output_put(&handle
, read_event
);
3978 perf_output_read(&handle
, event
);
3979 perf_event__output_id_sample(event
, &handle
, &sample
);
3981 perf_output_end(&handle
);
3985 * task tracking -- fork/exit
3987 * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
3990 struct perf_task_event
{
3991 struct task_struct
*task
;
3992 struct perf_event_context
*task_ctx
;
3995 struct perf_event_header header
;
4005 static void perf_event_task_output(struct perf_event
*event
,
4006 struct perf_task_event
*task_event
)
4008 struct perf_output_handle handle
;
4009 struct perf_sample_data sample
;
4010 struct task_struct
*task
= task_event
->task
;
4011 int ret
, size
= task_event
->event_id
.header
.size
;
4013 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4015 ret
= perf_output_begin(&handle
, event
,
4016 task_event
->event_id
.header
.size
);
4020 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4021 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4023 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4024 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4026 perf_output_put(&handle
, task_event
->event_id
);
4028 perf_event__output_id_sample(event
, &handle
, &sample
);
4030 perf_output_end(&handle
);
4032 task_event
->event_id
.header
.size
= size
;
4035 static int perf_event_task_match(struct perf_event
*event
)
4037 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4040 if (!event_filter_match(event
))
4043 if (event
->attr
.comm
|| event
->attr
.mmap
||
4044 event
->attr
.mmap_data
|| event
->attr
.task
)
4050 static void perf_event_task_ctx(struct perf_event_context
*ctx
,
4051 struct perf_task_event
*task_event
)
4053 struct perf_event
*event
;
4055 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4056 if (perf_event_task_match(event
))
4057 perf_event_task_output(event
, task_event
);
4061 static void perf_event_task_event(struct perf_task_event
*task_event
)
4063 struct perf_cpu_context
*cpuctx
;
4064 struct perf_event_context
*ctx
;
4069 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4070 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4071 if (cpuctx
->active_pmu
!= pmu
)
4073 perf_event_task_ctx(&cpuctx
->ctx
, task_event
);
4075 ctx
= task_event
->task_ctx
;
4077 ctxn
= pmu
->task_ctx_nr
;
4080 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4083 perf_event_task_ctx(ctx
, task_event
);
4085 put_cpu_ptr(pmu
->pmu_cpu_context
);
4090 static void perf_event_task(struct task_struct
*task
,
4091 struct perf_event_context
*task_ctx
,
4094 struct perf_task_event task_event
;
4096 if (!atomic_read(&nr_comm_events
) &&
4097 !atomic_read(&nr_mmap_events
) &&
4098 !atomic_read(&nr_task_events
))
4101 task_event
= (struct perf_task_event
){
4103 .task_ctx
= task_ctx
,
4106 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
4108 .size
= sizeof(task_event
.event_id
),
4114 .time
= perf_clock(),
4118 perf_event_task_event(&task_event
);
4121 void perf_event_fork(struct task_struct
*task
)
4123 perf_event_task(task
, NULL
, 1);
4130 struct perf_comm_event
{
4131 struct task_struct
*task
;
4136 struct perf_event_header header
;
4143 static void perf_event_comm_output(struct perf_event
*event
,
4144 struct perf_comm_event
*comm_event
)
4146 struct perf_output_handle handle
;
4147 struct perf_sample_data sample
;
4148 int size
= comm_event
->event_id
.header
.size
;
4151 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
4152 ret
= perf_output_begin(&handle
, event
,
4153 comm_event
->event_id
.header
.size
);
4158 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
4159 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
4161 perf_output_put(&handle
, comm_event
->event_id
);
4162 __output_copy(&handle
, comm_event
->comm
,
4163 comm_event
->comm_size
);
4165 perf_event__output_id_sample(event
, &handle
, &sample
);
4167 perf_output_end(&handle
);
4169 comm_event
->event_id
.header
.size
= size
;
4172 static int perf_event_comm_match(struct perf_event
*event
)
4174 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4177 if (!event_filter_match(event
))
4180 if (event
->attr
.comm
)
4186 static void perf_event_comm_ctx(struct perf_event_context
*ctx
,
4187 struct perf_comm_event
*comm_event
)
4189 struct perf_event
*event
;
4191 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4192 if (perf_event_comm_match(event
))
4193 perf_event_comm_output(event
, comm_event
);
4197 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
4199 struct perf_cpu_context
*cpuctx
;
4200 struct perf_event_context
*ctx
;
4201 char comm
[TASK_COMM_LEN
];
4206 memset(comm
, 0, sizeof(comm
));
4207 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
4208 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
4210 comm_event
->comm
= comm
;
4211 comm_event
->comm_size
= size
;
4213 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
4215 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4216 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4217 if (cpuctx
->active_pmu
!= pmu
)
4219 perf_event_comm_ctx(&cpuctx
->ctx
, comm_event
);
4221 ctxn
= pmu
->task_ctx_nr
;
4225 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4227 perf_event_comm_ctx(ctx
, comm_event
);
4229 put_cpu_ptr(pmu
->pmu_cpu_context
);
4234 void perf_event_comm(struct task_struct
*task
)
4236 struct perf_comm_event comm_event
;
4237 struct perf_event_context
*ctx
;
4240 for_each_task_context_nr(ctxn
) {
4241 ctx
= task
->perf_event_ctxp
[ctxn
];
4245 perf_event_enable_on_exec(ctx
);
4248 if (!atomic_read(&nr_comm_events
))
4251 comm_event
= (struct perf_comm_event
){
4257 .type
= PERF_RECORD_COMM
,
4266 perf_event_comm_event(&comm_event
);
4273 struct perf_mmap_event
{
4274 struct vm_area_struct
*vma
;
4276 const char *file_name
;
4280 struct perf_event_header header
;
4290 static void perf_event_mmap_output(struct perf_event
*event
,
4291 struct perf_mmap_event
*mmap_event
)
4293 struct perf_output_handle handle
;
4294 struct perf_sample_data sample
;
4295 int size
= mmap_event
->event_id
.header
.size
;
4298 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
4299 ret
= perf_output_begin(&handle
, event
,
4300 mmap_event
->event_id
.header
.size
);
4304 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
4305 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
4307 perf_output_put(&handle
, mmap_event
->event_id
);
4308 __output_copy(&handle
, mmap_event
->file_name
,
4309 mmap_event
->file_size
);
4311 perf_event__output_id_sample(event
, &handle
, &sample
);
4313 perf_output_end(&handle
);
4315 mmap_event
->event_id
.header
.size
= size
;
4318 static int perf_event_mmap_match(struct perf_event
*event
,
4319 struct perf_mmap_event
*mmap_event
,
4322 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4325 if (!event_filter_match(event
))
4328 if ((!executable
&& event
->attr
.mmap_data
) ||
4329 (executable
&& event
->attr
.mmap
))
4335 static void perf_event_mmap_ctx(struct perf_event_context
*ctx
,
4336 struct perf_mmap_event
*mmap_event
,
4339 struct perf_event
*event
;
4341 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4342 if (perf_event_mmap_match(event
, mmap_event
, executable
))
4343 perf_event_mmap_output(event
, mmap_event
);
4347 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
4349 struct perf_cpu_context
*cpuctx
;
4350 struct perf_event_context
*ctx
;
4351 struct vm_area_struct
*vma
= mmap_event
->vma
;
4352 struct file
*file
= vma
->vm_file
;
4360 memset(tmp
, 0, sizeof(tmp
));
4364 * d_path works from the end of the rb backwards, so we
4365 * need to add enough zero bytes after the string to handle
4366 * the 64bit alignment we do later.
4368 buf
= kzalloc(PATH_MAX
+ sizeof(u64
), GFP_KERNEL
);
4370 name
= strncpy(tmp
, "//enomem", sizeof(tmp
));
4373 name
= d_path(&file
->f_path
, buf
, PATH_MAX
);
4375 name
= strncpy(tmp
, "//toolong", sizeof(tmp
));
4379 if (arch_vma_name(mmap_event
->vma
)) {
4380 name
= strncpy(tmp
, arch_vma_name(mmap_event
->vma
),
4386 name
= strncpy(tmp
, "[vdso]", sizeof(tmp
));
4388 } else if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
4389 vma
->vm_end
>= vma
->vm_mm
->brk
) {
4390 name
= strncpy(tmp
, "[heap]", sizeof(tmp
));
4392 } else if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
4393 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
4394 name
= strncpy(tmp
, "[stack]", sizeof(tmp
));
4398 name
= strncpy(tmp
, "//anon", sizeof(tmp
));
4403 size
= ALIGN(strlen(name
)+1, sizeof(u64
));
4405 mmap_event
->file_name
= name
;
4406 mmap_event
->file_size
= size
;
4408 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
4411 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4412 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4413 if (cpuctx
->active_pmu
!= pmu
)
4415 perf_event_mmap_ctx(&cpuctx
->ctx
, mmap_event
,
4416 vma
->vm_flags
& VM_EXEC
);
4418 ctxn
= pmu
->task_ctx_nr
;
4422 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4424 perf_event_mmap_ctx(ctx
, mmap_event
,
4425 vma
->vm_flags
& VM_EXEC
);
4428 put_cpu_ptr(pmu
->pmu_cpu_context
);
4435 void perf_event_mmap(struct vm_area_struct
*vma
)
4437 struct perf_mmap_event mmap_event
;
4439 if (!atomic_read(&nr_mmap_events
))
4442 mmap_event
= (struct perf_mmap_event
){
4448 .type
= PERF_RECORD_MMAP
,
4449 .misc
= PERF_RECORD_MISC_USER
,
4454 .start
= vma
->vm_start
,
4455 .len
= vma
->vm_end
- vma
->vm_start
,
4456 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
4460 perf_event_mmap_event(&mmap_event
);
4464 * IRQ throttle logging
4467 static void perf_log_throttle(struct perf_event
*event
, int enable
)
4469 struct perf_output_handle handle
;
4470 struct perf_sample_data sample
;
4474 struct perf_event_header header
;
4478 } throttle_event
= {
4480 .type
= PERF_RECORD_THROTTLE
,
4482 .size
= sizeof(throttle_event
),
4484 .time
= perf_clock(),
4485 .id
= primary_event_id(event
),
4486 .stream_id
= event
->id
,
4490 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
4492 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
4494 ret
= perf_output_begin(&handle
, event
,
4495 throttle_event
.header
.size
);
4499 perf_output_put(&handle
, throttle_event
);
4500 perf_event__output_id_sample(event
, &handle
, &sample
);
4501 perf_output_end(&handle
);
4505 * Generic event overflow handling, sampling.
4508 static int __perf_event_overflow(struct perf_event
*event
,
4509 int throttle
, struct perf_sample_data
*data
,
4510 struct pt_regs
*regs
)
4512 int events
= atomic_read(&event
->event_limit
);
4513 struct hw_perf_event
*hwc
= &event
->hw
;
4517 * Non-sampling counters might still use the PMI to fold short
4518 * hardware counters, ignore those.
4520 if (unlikely(!is_sampling_event(event
)))
4523 if (unlikely(hwc
->interrupts
>= max_samples_per_tick
)) {
4525 hwc
->interrupts
= MAX_INTERRUPTS
;
4526 perf_log_throttle(event
, 0);
4532 if (event
->attr
.freq
) {
4533 u64 now
= perf_clock();
4534 s64 delta
= now
- hwc
->freq_time_stamp
;
4536 hwc
->freq_time_stamp
= now
;
4538 if (delta
> 0 && delta
< 2*TICK_NSEC
)
4539 perf_adjust_period(event
, delta
, hwc
->last_period
);
4543 * XXX event_limit might not quite work as expected on inherited
4547 event
->pending_kill
= POLL_IN
;
4548 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
4550 event
->pending_kill
= POLL_HUP
;
4551 event
->pending_disable
= 1;
4552 irq_work_queue(&event
->pending
);
4555 if (event
->overflow_handler
)
4556 event
->overflow_handler(event
, data
, regs
);
4558 perf_event_output(event
, data
, regs
);
4560 if (event
->fasync
&& event
->pending_kill
) {
4561 event
->pending_wakeup
= 1;
4562 irq_work_queue(&event
->pending
);
4568 int perf_event_overflow(struct perf_event
*event
,
4569 struct perf_sample_data
*data
,
4570 struct pt_regs
*regs
)
4572 return __perf_event_overflow(event
, 1, data
, regs
);
4576 * Generic software event infrastructure
4579 struct swevent_htable
{
4580 struct swevent_hlist
*swevent_hlist
;
4581 struct mutex hlist_mutex
;
4584 /* Recursion avoidance in each contexts */
4585 int recursion
[PERF_NR_CONTEXTS
];
4588 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
4591 * We directly increment event->count and keep a second value in
4592 * event->hw.period_left to count intervals. This period event
4593 * is kept in the range [-sample_period, 0] so that we can use the
4597 static u64
perf_swevent_set_period(struct perf_event
*event
)
4599 struct hw_perf_event
*hwc
= &event
->hw
;
4600 u64 period
= hwc
->last_period
;
4604 hwc
->last_period
= hwc
->sample_period
;
4607 old
= val
= local64_read(&hwc
->period_left
);
4611 nr
= div64_u64(period
+ val
, period
);
4612 offset
= nr
* period
;
4614 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
4620 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
4621 struct perf_sample_data
*data
,
4622 struct pt_regs
*regs
)
4624 struct hw_perf_event
*hwc
= &event
->hw
;
4628 overflow
= perf_swevent_set_period(event
);
4630 if (hwc
->interrupts
== MAX_INTERRUPTS
)
4633 for (; overflow
; overflow
--) {
4634 if (__perf_event_overflow(event
, throttle
,
4637 * We inhibit the overflow from happening when
4638 * hwc->interrupts == MAX_INTERRUPTS.
4646 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
4647 struct perf_sample_data
*data
,
4648 struct pt_regs
*regs
)
4650 struct hw_perf_event
*hwc
= &event
->hw
;
4652 local64_add(nr
, &event
->count
);
4657 if (!is_sampling_event(event
))
4660 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
4662 return perf_swevent_overflow(event
, 1, data
, regs
);
4664 data
->period
= event
->hw
.last_period
;
4666 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
4667 return perf_swevent_overflow(event
, 1, data
, regs
);
4669 if (local64_add_negative(nr
, &hwc
->period_left
))
4672 perf_swevent_overflow(event
, 0, data
, regs
);
4675 static int perf_exclude_event(struct perf_event
*event
,
4676 struct pt_regs
*regs
)
4678 if (event
->hw
.state
& PERF_HES_STOPPED
)
4682 if (event
->attr
.exclude_user
&& user_mode(regs
))
4685 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
4692 static int perf_swevent_match(struct perf_event
*event
,
4693 enum perf_type_id type
,
4695 struct perf_sample_data
*data
,
4696 struct pt_regs
*regs
)
4698 if (event
->attr
.type
!= type
)
4701 if (event
->attr
.config
!= event_id
)
4704 if (perf_exclude_event(event
, regs
))
4710 static inline u64
swevent_hash(u64 type
, u32 event_id
)
4712 u64 val
= event_id
| (type
<< 32);
4714 return hash_64(val
, SWEVENT_HLIST_BITS
);
4717 static inline struct hlist_head
*
4718 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
4720 u64 hash
= swevent_hash(type
, event_id
);
4722 return &hlist
->heads
[hash
];
4725 /* For the read side: events when they trigger */
4726 static inline struct hlist_head
*
4727 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
4729 struct swevent_hlist
*hlist
;
4731 hlist
= rcu_dereference(swhash
->swevent_hlist
);
4735 return __find_swevent_head(hlist
, type
, event_id
);
4738 /* For the event head insertion and removal in the hlist */
4739 static inline struct hlist_head
*
4740 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
4742 struct swevent_hlist
*hlist
;
4743 u32 event_id
= event
->attr
.config
;
4744 u64 type
= event
->attr
.type
;
4747 * Event scheduling is always serialized against hlist allocation
4748 * and release. Which makes the protected version suitable here.
4749 * The context lock guarantees that.
4751 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
4752 lockdep_is_held(&event
->ctx
->lock
));
4756 return __find_swevent_head(hlist
, type
, event_id
);
4759 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
4761 struct perf_sample_data
*data
,
4762 struct pt_regs
*regs
)
4764 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4765 struct perf_event
*event
;
4766 struct hlist_node
*node
;
4767 struct hlist_head
*head
;
4770 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
4774 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
4775 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
4776 perf_swevent_event(event
, nr
, data
, regs
);
4782 int perf_swevent_get_recursion_context(void)
4784 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4786 return get_recursion_context(swhash
->recursion
);
4788 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
4790 inline void perf_swevent_put_recursion_context(int rctx
)
4792 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4794 put_recursion_context(swhash
->recursion
, rctx
);
4797 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
4799 struct perf_sample_data data
;
4802 preempt_disable_notrace();
4803 rctx
= perf_swevent_get_recursion_context();
4807 perf_sample_data_init(&data
, addr
);
4809 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
4811 perf_swevent_put_recursion_context(rctx
);
4812 preempt_enable_notrace();
4815 static void perf_swevent_read(struct perf_event
*event
)
4819 static int perf_swevent_add(struct perf_event
*event
, int flags
)
4821 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
4822 struct hw_perf_event
*hwc
= &event
->hw
;
4823 struct hlist_head
*head
;
4825 if (is_sampling_event(event
)) {
4826 hwc
->last_period
= hwc
->sample_period
;
4827 perf_swevent_set_period(event
);
4830 hwc
->state
= !(flags
& PERF_EF_START
);
4832 head
= find_swevent_head(swhash
, event
);
4833 if (WARN_ON_ONCE(!head
))
4836 hlist_add_head_rcu(&event
->hlist_entry
, head
);
4841 static void perf_swevent_del(struct perf_event
*event
, int flags
)
4843 hlist_del_rcu(&event
->hlist_entry
);
4846 static void perf_swevent_start(struct perf_event
*event
, int flags
)
4848 event
->hw
.state
= 0;
4851 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
4853 event
->hw
.state
= PERF_HES_STOPPED
;
4856 /* Deref the hlist from the update side */
4857 static inline struct swevent_hlist
*
4858 swevent_hlist_deref(struct swevent_htable
*swhash
)
4860 return rcu_dereference_protected(swhash
->swevent_hlist
,
4861 lockdep_is_held(&swhash
->hlist_mutex
));
4864 static void swevent_hlist_release(struct swevent_htable
*swhash
)
4866 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
4871 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
4872 kfree_rcu(hlist
, rcu_head
);
4875 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
4877 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4879 mutex_lock(&swhash
->hlist_mutex
);
4881 if (!--swhash
->hlist_refcount
)
4882 swevent_hlist_release(swhash
);
4884 mutex_unlock(&swhash
->hlist_mutex
);
4887 static void swevent_hlist_put(struct perf_event
*event
)
4891 if (event
->cpu
!= -1) {
4892 swevent_hlist_put_cpu(event
, event
->cpu
);
4896 for_each_possible_cpu(cpu
)
4897 swevent_hlist_put_cpu(event
, cpu
);
4900 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
4902 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
4905 mutex_lock(&swhash
->hlist_mutex
);
4907 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
4908 struct swevent_hlist
*hlist
;
4910 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
4915 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
4917 swhash
->hlist_refcount
++;
4919 mutex_unlock(&swhash
->hlist_mutex
);
4924 static int swevent_hlist_get(struct perf_event
*event
)
4927 int cpu
, failed_cpu
;
4929 if (event
->cpu
!= -1)
4930 return swevent_hlist_get_cpu(event
, event
->cpu
);
4933 for_each_possible_cpu(cpu
) {
4934 err
= swevent_hlist_get_cpu(event
, cpu
);
4944 for_each_possible_cpu(cpu
) {
4945 if (cpu
== failed_cpu
)
4947 swevent_hlist_put_cpu(event
, cpu
);
4954 struct jump_label_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
4956 static void sw_perf_event_destroy(struct perf_event
*event
)
4958 u64 event_id
= event
->attr
.config
;
4960 WARN_ON(event
->parent
);
4962 jump_label_dec(&perf_swevent_enabled
[event_id
]);
4963 swevent_hlist_put(event
);
4966 static int perf_swevent_init(struct perf_event
*event
)
4968 int event_id
= event
->attr
.config
;
4970 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
4974 case PERF_COUNT_SW_CPU_CLOCK
:
4975 case PERF_COUNT_SW_TASK_CLOCK
:
4982 if (event_id
>= PERF_COUNT_SW_MAX
)
4985 if (!event
->parent
) {
4988 err
= swevent_hlist_get(event
);
4992 jump_label_inc(&perf_swevent_enabled
[event_id
]);
4993 event
->destroy
= sw_perf_event_destroy
;
4999 static struct pmu perf_swevent
= {
5000 .task_ctx_nr
= perf_sw_context
,
5002 .event_init
= perf_swevent_init
,
5003 .add
= perf_swevent_add
,
5004 .del
= perf_swevent_del
,
5005 .start
= perf_swevent_start
,
5006 .stop
= perf_swevent_stop
,
5007 .read
= perf_swevent_read
,
5010 #ifdef CONFIG_EVENT_TRACING
5012 static int perf_tp_filter_match(struct perf_event
*event
,
5013 struct perf_sample_data
*data
)
5015 void *record
= data
->raw
->data
;
5017 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5022 static int perf_tp_event_match(struct perf_event
*event
,
5023 struct perf_sample_data
*data
,
5024 struct pt_regs
*regs
)
5026 if (event
->hw
.state
& PERF_HES_STOPPED
)
5029 * All tracepoints are from kernel-space.
5031 if (event
->attr
.exclude_kernel
)
5034 if (!perf_tp_filter_match(event
, data
))
5040 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5041 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
)
5043 struct perf_sample_data data
;
5044 struct perf_event
*event
;
5045 struct hlist_node
*node
;
5047 struct perf_raw_record raw
= {
5052 perf_sample_data_init(&data
, addr
);
5055 hlist_for_each_entry_rcu(event
, node
, head
, hlist_entry
) {
5056 if (perf_tp_event_match(event
, &data
, regs
))
5057 perf_swevent_event(event
, count
, &data
, regs
);
5060 perf_swevent_put_recursion_context(rctx
);
5062 EXPORT_SYMBOL_GPL(perf_tp_event
);
5064 static void tp_perf_event_destroy(struct perf_event
*event
)
5066 perf_trace_destroy(event
);
5069 static int perf_tp_event_init(struct perf_event
*event
)
5073 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5076 err
= perf_trace_init(event
);
5080 event
->destroy
= tp_perf_event_destroy
;
5085 static struct pmu perf_tracepoint
= {
5086 .task_ctx_nr
= perf_sw_context
,
5088 .event_init
= perf_tp_event_init
,
5089 .add
= perf_trace_add
,
5090 .del
= perf_trace_del
,
5091 .start
= perf_swevent_start
,
5092 .stop
= perf_swevent_stop
,
5093 .read
= perf_swevent_read
,
5096 static inline void perf_tp_register(void)
5098 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
5101 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5106 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
5109 filter_str
= strndup_user(arg
, PAGE_SIZE
);
5110 if (IS_ERR(filter_str
))
5111 return PTR_ERR(filter_str
);
5113 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
5119 static void perf_event_free_filter(struct perf_event
*event
)
5121 ftrace_profile_free_filter(event
);
5126 static inline void perf_tp_register(void)
5130 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
5135 static void perf_event_free_filter(struct perf_event
*event
)
5139 #endif /* CONFIG_EVENT_TRACING */
5141 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5142 void perf_bp_event(struct perf_event
*bp
, void *data
)
5144 struct perf_sample_data sample
;
5145 struct pt_regs
*regs
= data
;
5147 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
);
5149 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
5150 perf_swevent_event(bp
, 1, &sample
, regs
);
5155 * hrtimer based swevent callback
5158 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
5160 enum hrtimer_restart ret
= HRTIMER_RESTART
;
5161 struct perf_sample_data data
;
5162 struct pt_regs
*regs
;
5163 struct perf_event
*event
;
5166 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
5168 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
5169 return HRTIMER_NORESTART
;
5171 event
->pmu
->read(event
);
5173 perf_sample_data_init(&data
, 0);
5174 data
.period
= event
->hw
.last_period
;
5175 regs
= get_irq_regs();
5177 if (regs
&& !perf_exclude_event(event
, regs
)) {
5178 if (!(event
->attr
.exclude_idle
&& current
->pid
== 0))
5179 if (perf_event_overflow(event
, &data
, regs
))
5180 ret
= HRTIMER_NORESTART
;
5183 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
5184 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
5189 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
5191 struct hw_perf_event
*hwc
= &event
->hw
;
5194 if (!is_sampling_event(event
))
5197 period
= local64_read(&hwc
->period_left
);
5202 local64_set(&hwc
->period_left
, 0);
5204 period
= max_t(u64
, 10000, hwc
->sample_period
);
5206 __hrtimer_start_range_ns(&hwc
->hrtimer
,
5207 ns_to_ktime(period
), 0,
5208 HRTIMER_MODE_REL_PINNED
, 0);
5211 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
5213 struct hw_perf_event
*hwc
= &event
->hw
;
5215 if (is_sampling_event(event
)) {
5216 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
5217 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
5219 hrtimer_cancel(&hwc
->hrtimer
);
5223 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
5225 struct hw_perf_event
*hwc
= &event
->hw
;
5227 if (!is_sampling_event(event
))
5230 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
5231 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
5234 * Since hrtimers have a fixed rate, we can do a static freq->period
5235 * mapping and avoid the whole period adjust feedback stuff.
5237 if (event
->attr
.freq
) {
5238 long freq
= event
->attr
.sample_freq
;
5240 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
5241 hwc
->sample_period
= event
->attr
.sample_period
;
5242 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5243 event
->attr
.freq
= 0;
5248 * Software event: cpu wall time clock
5251 static void cpu_clock_event_update(struct perf_event
*event
)
5256 now
= local_clock();
5257 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5258 local64_add(now
- prev
, &event
->count
);
5261 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
5263 local64_set(&event
->hw
.prev_count
, local_clock());
5264 perf_swevent_start_hrtimer(event
);
5267 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
5269 perf_swevent_cancel_hrtimer(event
);
5270 cpu_clock_event_update(event
);
5273 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
5275 if (flags
& PERF_EF_START
)
5276 cpu_clock_event_start(event
, flags
);
5281 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
5283 cpu_clock_event_stop(event
, flags
);
5286 static void cpu_clock_event_read(struct perf_event
*event
)
5288 cpu_clock_event_update(event
);
5291 static int cpu_clock_event_init(struct perf_event
*event
)
5293 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5296 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
5299 perf_swevent_init_hrtimer(event
);
5304 static struct pmu perf_cpu_clock
= {
5305 .task_ctx_nr
= perf_sw_context
,
5307 .event_init
= cpu_clock_event_init
,
5308 .add
= cpu_clock_event_add
,
5309 .del
= cpu_clock_event_del
,
5310 .start
= cpu_clock_event_start
,
5311 .stop
= cpu_clock_event_stop
,
5312 .read
= cpu_clock_event_read
,
5316 * Software event: task time clock
5319 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
5324 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
5326 local64_add(delta
, &event
->count
);
5329 static void task_clock_event_start(struct perf_event
*event
, int flags
)
5331 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
5332 perf_swevent_start_hrtimer(event
);
5335 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
5337 perf_swevent_cancel_hrtimer(event
);
5338 task_clock_event_update(event
, event
->ctx
->time
);
5341 static int task_clock_event_add(struct perf_event
*event
, int flags
)
5343 if (flags
& PERF_EF_START
)
5344 task_clock_event_start(event
, flags
);
5349 static void task_clock_event_del(struct perf_event
*event
, int flags
)
5351 task_clock_event_stop(event
, PERF_EF_UPDATE
);
5354 static void task_clock_event_read(struct perf_event
*event
)
5356 u64 now
= perf_clock();
5357 u64 delta
= now
- event
->ctx
->timestamp
;
5358 u64 time
= event
->ctx
->time
+ delta
;
5360 task_clock_event_update(event
, time
);
5363 static int task_clock_event_init(struct perf_event
*event
)
5365 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5368 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
5371 perf_swevent_init_hrtimer(event
);
5376 static struct pmu perf_task_clock
= {
5377 .task_ctx_nr
= perf_sw_context
,
5379 .event_init
= task_clock_event_init
,
5380 .add
= task_clock_event_add
,
5381 .del
= task_clock_event_del
,
5382 .start
= task_clock_event_start
,
5383 .stop
= task_clock_event_stop
,
5384 .read
= task_clock_event_read
,
5387 static void perf_pmu_nop_void(struct pmu
*pmu
)
5391 static int perf_pmu_nop_int(struct pmu
*pmu
)
5396 static void perf_pmu_start_txn(struct pmu
*pmu
)
5398 perf_pmu_disable(pmu
);
5401 static int perf_pmu_commit_txn(struct pmu
*pmu
)
5403 perf_pmu_enable(pmu
);
5407 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
5409 perf_pmu_enable(pmu
);
5413 * Ensures all contexts with the same task_ctx_nr have the same
5414 * pmu_cpu_context too.
5416 static void *find_pmu_context(int ctxn
)
5423 list_for_each_entry(pmu
, &pmus
, entry
) {
5424 if (pmu
->task_ctx_nr
== ctxn
)
5425 return pmu
->pmu_cpu_context
;
5431 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
5435 for_each_possible_cpu(cpu
) {
5436 struct perf_cpu_context
*cpuctx
;
5438 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5440 if (cpuctx
->active_pmu
== old_pmu
)
5441 cpuctx
->active_pmu
= pmu
;
5445 static void free_pmu_context(struct pmu
*pmu
)
5449 mutex_lock(&pmus_lock
);
5451 * Like a real lame refcount.
5453 list_for_each_entry(i
, &pmus
, entry
) {
5454 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
5455 update_pmu_context(i
, pmu
);
5460 free_percpu(pmu
->pmu_cpu_context
);
5462 mutex_unlock(&pmus_lock
);
5464 static struct idr pmu_idr
;
5467 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
5469 struct pmu
*pmu
= dev_get_drvdata(dev
);
5471 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
5474 static struct device_attribute pmu_dev_attrs
[] = {
5479 static int pmu_bus_running
;
5480 static struct bus_type pmu_bus
= {
5481 .name
= "event_source",
5482 .dev_attrs
= pmu_dev_attrs
,
5485 static void pmu_dev_release(struct device
*dev
)
5490 static int pmu_dev_alloc(struct pmu
*pmu
)
5494 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
5498 device_initialize(pmu
->dev
);
5499 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
5503 dev_set_drvdata(pmu
->dev
, pmu
);
5504 pmu
->dev
->bus
= &pmu_bus
;
5505 pmu
->dev
->release
= pmu_dev_release
;
5506 ret
= device_add(pmu
->dev
);
5514 put_device(pmu
->dev
);
5518 static struct lock_class_key cpuctx_mutex
;
5519 static struct lock_class_key cpuctx_lock
;
5521 int perf_pmu_register(struct pmu
*pmu
, char *name
, int type
)
5525 mutex_lock(&pmus_lock
);
5527 pmu
->pmu_disable_count
= alloc_percpu(int);
5528 if (!pmu
->pmu_disable_count
)
5537 int err
= idr_pre_get(&pmu_idr
, GFP_KERNEL
);
5541 err
= idr_get_new_above(&pmu_idr
, pmu
, PERF_TYPE_MAX
, &type
);
5549 if (pmu_bus_running
) {
5550 ret
= pmu_dev_alloc(pmu
);
5556 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
5557 if (pmu
->pmu_cpu_context
)
5558 goto got_cpu_context
;
5560 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
5561 if (!pmu
->pmu_cpu_context
)
5564 for_each_possible_cpu(cpu
) {
5565 struct perf_cpu_context
*cpuctx
;
5567 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
5568 __perf_event_init_context(&cpuctx
->ctx
);
5569 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
5570 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
5571 cpuctx
->ctx
.type
= cpu_context
;
5572 cpuctx
->ctx
.pmu
= pmu
;
5573 cpuctx
->jiffies_interval
= 1;
5574 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
5575 cpuctx
->active_pmu
= pmu
;
5579 if (!pmu
->start_txn
) {
5580 if (pmu
->pmu_enable
) {
5582 * If we have pmu_enable/pmu_disable calls, install
5583 * transaction stubs that use that to try and batch
5584 * hardware accesses.
5586 pmu
->start_txn
= perf_pmu_start_txn
;
5587 pmu
->commit_txn
= perf_pmu_commit_txn
;
5588 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
5590 pmu
->start_txn
= perf_pmu_nop_void
;
5591 pmu
->commit_txn
= perf_pmu_nop_int
;
5592 pmu
->cancel_txn
= perf_pmu_nop_void
;
5596 if (!pmu
->pmu_enable
) {
5597 pmu
->pmu_enable
= perf_pmu_nop_void
;
5598 pmu
->pmu_disable
= perf_pmu_nop_void
;
5601 list_add_rcu(&pmu
->entry
, &pmus
);
5604 mutex_unlock(&pmus_lock
);
5609 device_del(pmu
->dev
);
5610 put_device(pmu
->dev
);
5613 if (pmu
->type
>= PERF_TYPE_MAX
)
5614 idr_remove(&pmu_idr
, pmu
->type
);
5617 free_percpu(pmu
->pmu_disable_count
);
5621 void perf_pmu_unregister(struct pmu
*pmu
)
5623 mutex_lock(&pmus_lock
);
5624 list_del_rcu(&pmu
->entry
);
5625 mutex_unlock(&pmus_lock
);
5628 * We dereference the pmu list under both SRCU and regular RCU, so
5629 * synchronize against both of those.
5631 synchronize_srcu(&pmus_srcu
);
5634 free_percpu(pmu
->pmu_disable_count
);
5635 if (pmu
->type
>= PERF_TYPE_MAX
)
5636 idr_remove(&pmu_idr
, pmu
->type
);
5637 device_del(pmu
->dev
);
5638 put_device(pmu
->dev
);
5639 free_pmu_context(pmu
);
5642 struct pmu
*perf_init_event(struct perf_event
*event
)
5644 struct pmu
*pmu
= NULL
;
5648 idx
= srcu_read_lock(&pmus_srcu
);
5651 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
5655 ret
= pmu
->event_init(event
);
5661 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5663 ret
= pmu
->event_init(event
);
5667 if (ret
!= -ENOENT
) {
5672 pmu
= ERR_PTR(-ENOENT
);
5674 srcu_read_unlock(&pmus_srcu
, idx
);
5680 * Allocate and initialize a event structure
5682 static struct perf_event
*
5683 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
5684 struct task_struct
*task
,
5685 struct perf_event
*group_leader
,
5686 struct perf_event
*parent_event
,
5687 perf_overflow_handler_t overflow_handler
,
5691 struct perf_event
*event
;
5692 struct hw_perf_event
*hwc
;
5695 if ((unsigned)cpu
>= nr_cpu_ids
) {
5696 if (!task
|| cpu
!= -1)
5697 return ERR_PTR(-EINVAL
);
5700 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
5702 return ERR_PTR(-ENOMEM
);
5705 * Single events are their own group leaders, with an
5706 * empty sibling list:
5709 group_leader
= event
;
5711 mutex_init(&event
->child_mutex
);
5712 INIT_LIST_HEAD(&event
->child_list
);
5714 INIT_LIST_HEAD(&event
->group_entry
);
5715 INIT_LIST_HEAD(&event
->event_entry
);
5716 INIT_LIST_HEAD(&event
->sibling_list
);
5717 INIT_LIST_HEAD(&event
->rb_entry
);
5719 init_waitqueue_head(&event
->waitq
);
5720 init_irq_work(&event
->pending
, perf_pending_event
);
5722 mutex_init(&event
->mmap_mutex
);
5725 event
->attr
= *attr
;
5726 event
->group_leader
= group_leader
;
5730 event
->parent
= parent_event
;
5732 event
->ns
= get_pid_ns(current
->nsproxy
->pid_ns
);
5733 event
->id
= atomic64_inc_return(&perf_event_id
);
5735 event
->state
= PERF_EVENT_STATE_INACTIVE
;
5738 event
->attach_state
= PERF_ATTACH_TASK
;
5739 #ifdef CONFIG_HAVE_HW_BREAKPOINT
5741 * hw_breakpoint is a bit difficult here..
5743 if (attr
->type
== PERF_TYPE_BREAKPOINT
)
5744 event
->hw
.bp_target
= task
;
5748 if (!overflow_handler
&& parent_event
) {
5749 overflow_handler
= parent_event
->overflow_handler
;
5750 context
= parent_event
->overflow_handler_context
;
5753 event
->overflow_handler
= overflow_handler
;
5754 event
->overflow_handler_context
= context
;
5757 event
->state
= PERF_EVENT_STATE_OFF
;
5762 hwc
->sample_period
= attr
->sample_period
;
5763 if (attr
->freq
&& attr
->sample_freq
)
5764 hwc
->sample_period
= 1;
5765 hwc
->last_period
= hwc
->sample_period
;
5767 local64_set(&hwc
->period_left
, hwc
->sample_period
);
5770 * we currently do not support PERF_FORMAT_GROUP on inherited events
5772 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
5775 pmu
= perf_init_event(event
);
5781 else if (IS_ERR(pmu
))
5786 put_pid_ns(event
->ns
);
5788 return ERR_PTR(err
);
5791 if (!event
->parent
) {
5792 if (event
->attach_state
& PERF_ATTACH_TASK
)
5793 jump_label_inc(&perf_sched_events
);
5794 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
5795 atomic_inc(&nr_mmap_events
);
5796 if (event
->attr
.comm
)
5797 atomic_inc(&nr_comm_events
);
5798 if (event
->attr
.task
)
5799 atomic_inc(&nr_task_events
);
5800 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5801 err
= get_callchain_buffers();
5804 return ERR_PTR(err
);
5812 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
5813 struct perf_event_attr
*attr
)
5818 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
5822 * zero the full structure, so that a short copy will be nice.
5824 memset(attr
, 0, sizeof(*attr
));
5826 ret
= get_user(size
, &uattr
->size
);
5830 if (size
> PAGE_SIZE
) /* silly large */
5833 if (!size
) /* abi compat */
5834 size
= PERF_ATTR_SIZE_VER0
;
5836 if (size
< PERF_ATTR_SIZE_VER0
)
5840 * If we're handed a bigger struct than we know of,
5841 * ensure all the unknown bits are 0 - i.e. new
5842 * user-space does not rely on any kernel feature
5843 * extensions we dont know about yet.
5845 if (size
> sizeof(*attr
)) {
5846 unsigned char __user
*addr
;
5847 unsigned char __user
*end
;
5850 addr
= (void __user
*)uattr
+ sizeof(*attr
);
5851 end
= (void __user
*)uattr
+ size
;
5853 for (; addr
< end
; addr
++) {
5854 ret
= get_user(val
, addr
);
5860 size
= sizeof(*attr
);
5863 ret
= copy_from_user(attr
, uattr
, size
);
5867 if (attr
->__reserved_1
)
5870 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
5873 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
5880 put_user(sizeof(*attr
), &uattr
->size
);
5886 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
5888 struct ring_buffer
*rb
= NULL
, *old_rb
= NULL
;
5894 /* don't allow circular references */
5895 if (event
== output_event
)
5899 * Don't allow cross-cpu buffers
5901 if (output_event
->cpu
!= event
->cpu
)
5905 * If its not a per-cpu rb, it must be the same task.
5907 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
5911 mutex_lock(&event
->mmap_mutex
);
5912 /* Can't redirect output if we've got an active mmap() */
5913 if (atomic_read(&event
->mmap_count
))
5917 /* get the rb we want to redirect to */
5918 rb
= ring_buffer_get(output_event
);
5924 rcu_assign_pointer(event
->rb
, rb
);
5926 ring_buffer_detach(event
, old_rb
);
5929 mutex_unlock(&event
->mmap_mutex
);
5932 ring_buffer_put(old_rb
);
5938 * sys_perf_event_open - open a performance event, associate it to a task/cpu
5940 * @attr_uptr: event_id type attributes for monitoring/sampling
5943 * @group_fd: group leader event fd
5945 SYSCALL_DEFINE5(perf_event_open
,
5946 struct perf_event_attr __user
*, attr_uptr
,
5947 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
5949 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
5950 struct perf_event
*event
, *sibling
;
5951 struct perf_event_attr attr
;
5952 struct perf_event_context
*ctx
;
5953 struct file
*event_file
= NULL
;
5954 struct file
*group_file
= NULL
;
5955 struct task_struct
*task
= NULL
;
5959 int fput_needed
= 0;
5962 /* for future expandability... */
5963 if (flags
& ~PERF_FLAG_ALL
)
5966 err
= perf_copy_attr(attr_uptr
, &attr
);
5970 if (!attr
.exclude_kernel
) {
5971 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
5976 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
5981 * In cgroup mode, the pid argument is used to pass the fd
5982 * opened to the cgroup directory in cgroupfs. The cpu argument
5983 * designates the cpu on which to monitor threads from that
5986 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
5989 event_fd
= get_unused_fd_flags(O_RDWR
);
5993 if (group_fd
!= -1) {
5994 group_leader
= perf_fget_light(group_fd
, &fput_needed
);
5995 if (IS_ERR(group_leader
)) {
5996 err
= PTR_ERR(group_leader
);
5999 group_file
= group_leader
->filp
;
6000 if (flags
& PERF_FLAG_FD_OUTPUT
)
6001 output_event
= group_leader
;
6002 if (flags
& PERF_FLAG_FD_NO_GROUP
)
6003 group_leader
= NULL
;
6006 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
6007 task
= find_lively_task_by_vpid(pid
);
6009 err
= PTR_ERR(task
);
6014 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
6016 if (IS_ERR(event
)) {
6017 err
= PTR_ERR(event
);
6021 if (flags
& PERF_FLAG_PID_CGROUP
) {
6022 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
6027 * - that has cgroup constraint on event->cpu
6028 * - that may need work on context switch
6030 atomic_inc(&per_cpu(perf_cgroup_events
, event
->cpu
));
6031 jump_label_inc(&perf_sched_events
);
6035 * Special case software events and allow them to be part of
6036 * any hardware group.
6041 (is_software_event(event
) != is_software_event(group_leader
))) {
6042 if (is_software_event(event
)) {
6044 * If event and group_leader are not both a software
6045 * event, and event is, then group leader is not.
6047 * Allow the addition of software events to !software
6048 * groups, this is safe because software events never
6051 pmu
= group_leader
->pmu
;
6052 } else if (is_software_event(group_leader
) &&
6053 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
6055 * In case the group is a pure software group, and we
6056 * try to add a hardware event, move the whole group to
6057 * the hardware context.
6064 * Get the target context (task or percpu):
6066 ctx
= find_get_context(pmu
, task
, cpu
);
6073 put_task_struct(task
);
6078 * Look up the group leader (we will attach this event to it):
6084 * Do not allow a recursive hierarchy (this new sibling
6085 * becoming part of another group-sibling):
6087 if (group_leader
->group_leader
!= group_leader
)
6090 * Do not allow to attach to a group in a different
6091 * task or CPU context:
6094 if (group_leader
->ctx
->type
!= ctx
->type
)
6097 if (group_leader
->ctx
!= ctx
)
6102 * Only a group leader can be exclusive or pinned
6104 if (attr
.exclusive
|| attr
.pinned
)
6109 err
= perf_event_set_output(event
, output_event
);
6114 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
, O_RDWR
);
6115 if (IS_ERR(event_file
)) {
6116 err
= PTR_ERR(event_file
);
6121 struct perf_event_context
*gctx
= group_leader
->ctx
;
6123 mutex_lock(&gctx
->mutex
);
6124 perf_remove_from_context(group_leader
);
6125 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6127 perf_remove_from_context(sibling
);
6130 mutex_unlock(&gctx
->mutex
);
6134 event
->filp
= event_file
;
6135 WARN_ON_ONCE(ctx
->parent_ctx
);
6136 mutex_lock(&ctx
->mutex
);
6139 perf_install_in_context(ctx
, group_leader
, cpu
);
6141 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
6143 perf_install_in_context(ctx
, sibling
, cpu
);
6148 perf_install_in_context(ctx
, event
, cpu
);
6150 perf_unpin_context(ctx
);
6151 mutex_unlock(&ctx
->mutex
);
6153 event
->owner
= current
;
6155 mutex_lock(¤t
->perf_event_mutex
);
6156 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
6157 mutex_unlock(¤t
->perf_event_mutex
);
6160 * Precalculate sample_data sizes
6162 perf_event__header_size(event
);
6163 perf_event__id_header_size(event
);
6166 * Drop the reference on the group_event after placing the
6167 * new event on the sibling_list. This ensures destruction
6168 * of the group leader will find the pointer to itself in
6169 * perf_group_detach().
6171 fput_light(group_file
, fput_needed
);
6172 fd_install(event_fd
, event_file
);
6176 perf_unpin_context(ctx
);
6182 put_task_struct(task
);
6184 fput_light(group_file
, fput_needed
);
6186 put_unused_fd(event_fd
);
6191 * perf_event_create_kernel_counter
6193 * @attr: attributes of the counter to create
6194 * @cpu: cpu in which the counter is bound
6195 * @task: task to profile (NULL for percpu)
6198 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
6199 struct task_struct
*task
,
6200 perf_overflow_handler_t overflow_handler
,
6203 struct perf_event_context
*ctx
;
6204 struct perf_event
*event
;
6208 * Get the target context (task or percpu):
6211 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
6212 overflow_handler
, context
);
6213 if (IS_ERR(event
)) {
6214 err
= PTR_ERR(event
);
6218 ctx
= find_get_context(event
->pmu
, task
, cpu
);
6225 WARN_ON_ONCE(ctx
->parent_ctx
);
6226 mutex_lock(&ctx
->mutex
);
6227 perf_install_in_context(ctx
, event
, cpu
);
6229 perf_unpin_context(ctx
);
6230 mutex_unlock(&ctx
->mutex
);
6237 return ERR_PTR(err
);
6239 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
6241 static void sync_child_event(struct perf_event
*child_event
,
6242 struct task_struct
*child
)
6244 struct perf_event
*parent_event
= child_event
->parent
;
6247 if (child_event
->attr
.inherit_stat
)
6248 perf_event_read_event(child_event
, child
);
6250 child_val
= perf_event_count(child_event
);
6253 * Add back the child's count to the parent's count:
6255 atomic64_add(child_val
, &parent_event
->child_count
);
6256 atomic64_add(child_event
->total_time_enabled
,
6257 &parent_event
->child_total_time_enabled
);
6258 atomic64_add(child_event
->total_time_running
,
6259 &parent_event
->child_total_time_running
);
6262 * Remove this event from the parent's list
6264 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6265 mutex_lock(&parent_event
->child_mutex
);
6266 list_del_init(&child_event
->child_list
);
6267 mutex_unlock(&parent_event
->child_mutex
);
6270 * Release the parent event, if this was the last
6273 fput(parent_event
->filp
);
6277 __perf_event_exit_task(struct perf_event
*child_event
,
6278 struct perf_event_context
*child_ctx
,
6279 struct task_struct
*child
)
6281 if (child_event
->parent
) {
6282 raw_spin_lock_irq(&child_ctx
->lock
);
6283 perf_group_detach(child_event
);
6284 raw_spin_unlock_irq(&child_ctx
->lock
);
6287 perf_remove_from_context(child_event
);
6290 * It can happen that the parent exits first, and has events
6291 * that are still around due to the child reference. These
6292 * events need to be zapped.
6294 if (child_event
->parent
) {
6295 sync_child_event(child_event
, child
);
6296 free_event(child_event
);
6300 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
6302 struct perf_event
*child_event
, *tmp
;
6303 struct perf_event_context
*child_ctx
;
6304 unsigned long flags
;
6306 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
6307 perf_event_task(child
, NULL
, 0);
6311 local_irq_save(flags
);
6313 * We can't reschedule here because interrupts are disabled,
6314 * and either child is current or it is a task that can't be
6315 * scheduled, so we are now safe from rescheduling changing
6318 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
6321 * Take the context lock here so that if find_get_context is
6322 * reading child->perf_event_ctxp, we wait until it has
6323 * incremented the context's refcount before we do put_ctx below.
6325 raw_spin_lock(&child_ctx
->lock
);
6326 task_ctx_sched_out(child_ctx
);
6327 child
->perf_event_ctxp
[ctxn
] = NULL
;
6329 * If this context is a clone; unclone it so it can't get
6330 * swapped to another process while we're removing all
6331 * the events from it.
6333 unclone_ctx(child_ctx
);
6334 update_context_time(child_ctx
);
6335 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6338 * Report the task dead after unscheduling the events so that we
6339 * won't get any samples after PERF_RECORD_EXIT. We can however still
6340 * get a few PERF_RECORD_READ events.
6342 perf_event_task(child
, child_ctx
, 0);
6345 * We can recurse on the same lock type through:
6347 * __perf_event_exit_task()
6348 * sync_child_event()
6349 * fput(parent_event->filp)
6351 * mutex_lock(&ctx->mutex)
6353 * But since its the parent context it won't be the same instance.
6355 mutex_lock(&child_ctx
->mutex
);
6358 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->pinned_groups
,
6360 __perf_event_exit_task(child_event
, child_ctx
, child
);
6362 list_for_each_entry_safe(child_event
, tmp
, &child_ctx
->flexible_groups
,
6364 __perf_event_exit_task(child_event
, child_ctx
, child
);
6367 * If the last event was a group event, it will have appended all
6368 * its siblings to the list, but we obtained 'tmp' before that which
6369 * will still point to the list head terminating the iteration.
6371 if (!list_empty(&child_ctx
->pinned_groups
) ||
6372 !list_empty(&child_ctx
->flexible_groups
))
6375 mutex_unlock(&child_ctx
->mutex
);
6381 * When a child task exits, feed back event values to parent events.
6383 void perf_event_exit_task(struct task_struct
*child
)
6385 struct perf_event
*event
, *tmp
;
6388 mutex_lock(&child
->perf_event_mutex
);
6389 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
6391 list_del_init(&event
->owner_entry
);
6394 * Ensure the list deletion is visible before we clear
6395 * the owner, closes a race against perf_release() where
6396 * we need to serialize on the owner->perf_event_mutex.
6399 event
->owner
= NULL
;
6401 mutex_unlock(&child
->perf_event_mutex
);
6403 for_each_task_context_nr(ctxn
)
6404 perf_event_exit_task_context(child
, ctxn
);
6407 static void perf_free_event(struct perf_event
*event
,
6408 struct perf_event_context
*ctx
)
6410 struct perf_event
*parent
= event
->parent
;
6412 if (WARN_ON_ONCE(!parent
))
6415 mutex_lock(&parent
->child_mutex
);
6416 list_del_init(&event
->child_list
);
6417 mutex_unlock(&parent
->child_mutex
);
6421 perf_group_detach(event
);
6422 list_del_event(event
, ctx
);
6427 * free an unexposed, unused context as created by inheritance by
6428 * perf_event_init_task below, used by fork() in case of fail.
6430 void perf_event_free_task(struct task_struct
*task
)
6432 struct perf_event_context
*ctx
;
6433 struct perf_event
*event
, *tmp
;
6436 for_each_task_context_nr(ctxn
) {
6437 ctx
= task
->perf_event_ctxp
[ctxn
];
6441 mutex_lock(&ctx
->mutex
);
6443 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
6445 perf_free_event(event
, ctx
);
6447 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
6449 perf_free_event(event
, ctx
);
6451 if (!list_empty(&ctx
->pinned_groups
) ||
6452 !list_empty(&ctx
->flexible_groups
))
6455 mutex_unlock(&ctx
->mutex
);
6461 void perf_event_delayed_put(struct task_struct
*task
)
6465 for_each_task_context_nr(ctxn
)
6466 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
6470 * inherit a event from parent task to child task:
6472 static struct perf_event
*
6473 inherit_event(struct perf_event
*parent_event
,
6474 struct task_struct
*parent
,
6475 struct perf_event_context
*parent_ctx
,
6476 struct task_struct
*child
,
6477 struct perf_event
*group_leader
,
6478 struct perf_event_context
*child_ctx
)
6480 struct perf_event
*child_event
;
6481 unsigned long flags
;
6484 * Instead of creating recursive hierarchies of events,
6485 * we link inherited events back to the original parent,
6486 * which has a filp for sure, which we use as the reference
6489 if (parent_event
->parent
)
6490 parent_event
= parent_event
->parent
;
6492 child_event
= perf_event_alloc(&parent_event
->attr
,
6495 group_leader
, parent_event
,
6497 if (IS_ERR(child_event
))
6502 * Make the child state follow the state of the parent event,
6503 * not its attr.disabled bit. We hold the parent's mutex,
6504 * so we won't race with perf_event_{en, dis}able_family.
6506 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
6507 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
6509 child_event
->state
= PERF_EVENT_STATE_OFF
;
6511 if (parent_event
->attr
.freq
) {
6512 u64 sample_period
= parent_event
->hw
.sample_period
;
6513 struct hw_perf_event
*hwc
= &child_event
->hw
;
6515 hwc
->sample_period
= sample_period
;
6516 hwc
->last_period
= sample_period
;
6518 local64_set(&hwc
->period_left
, sample_period
);
6521 child_event
->ctx
= child_ctx
;
6522 child_event
->overflow_handler
= parent_event
->overflow_handler
;
6523 child_event
->overflow_handler_context
6524 = parent_event
->overflow_handler_context
;
6527 * Precalculate sample_data sizes
6529 perf_event__header_size(child_event
);
6530 perf_event__id_header_size(child_event
);
6533 * Link it up in the child's context:
6535 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
6536 add_event_to_ctx(child_event
, child_ctx
);
6537 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
6540 * Get a reference to the parent filp - we will fput it
6541 * when the child event exits. This is safe to do because
6542 * we are in the parent and we know that the filp still
6543 * exists and has a nonzero count:
6545 atomic_long_inc(&parent_event
->filp
->f_count
);
6548 * Link this into the parent event's child list
6550 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
6551 mutex_lock(&parent_event
->child_mutex
);
6552 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
6553 mutex_unlock(&parent_event
->child_mutex
);
6558 static int inherit_group(struct perf_event
*parent_event
,
6559 struct task_struct
*parent
,
6560 struct perf_event_context
*parent_ctx
,
6561 struct task_struct
*child
,
6562 struct perf_event_context
*child_ctx
)
6564 struct perf_event
*leader
;
6565 struct perf_event
*sub
;
6566 struct perf_event
*child_ctr
;
6568 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
6569 child
, NULL
, child_ctx
);
6571 return PTR_ERR(leader
);
6572 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
6573 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
6574 child
, leader
, child_ctx
);
6575 if (IS_ERR(child_ctr
))
6576 return PTR_ERR(child_ctr
);
6582 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
6583 struct perf_event_context
*parent_ctx
,
6584 struct task_struct
*child
, int ctxn
,
6588 struct perf_event_context
*child_ctx
;
6590 if (!event
->attr
.inherit
) {
6595 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6598 * This is executed from the parent task context, so
6599 * inherit events that have been marked for cloning.
6600 * First allocate and initialize a context for the
6604 child_ctx
= alloc_perf_context(event
->pmu
, child
);
6608 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
6611 ret
= inherit_group(event
, parent
, parent_ctx
,
6621 * Initialize the perf_event context in task_struct
6623 int perf_event_init_context(struct task_struct
*child
, int ctxn
)
6625 struct perf_event_context
*child_ctx
, *parent_ctx
;
6626 struct perf_event_context
*cloned_ctx
;
6627 struct perf_event
*event
;
6628 struct task_struct
*parent
= current
;
6629 int inherited_all
= 1;
6630 unsigned long flags
;
6633 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
6637 * If the parent's context is a clone, pin it so it won't get
6640 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
6643 * No need to check if parent_ctx != NULL here; since we saw
6644 * it non-NULL earlier, the only reason for it to become NULL
6645 * is if we exit, and since we're currently in the middle of
6646 * a fork we can't be exiting at the same time.
6650 * Lock the parent list. No need to lock the child - not PID
6651 * hashed yet and not running, so nobody can access it.
6653 mutex_lock(&parent_ctx
->mutex
);
6656 * We dont have to disable NMIs - we are only looking at
6657 * the list, not manipulating it:
6659 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
6660 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6661 child
, ctxn
, &inherited_all
);
6667 * We can't hold ctx->lock when iterating the ->flexible_group list due
6668 * to allocations, but we need to prevent rotation because
6669 * rotate_ctx() will change the list from interrupt context.
6671 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6672 parent_ctx
->rotate_disable
= 1;
6673 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6675 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
6676 ret
= inherit_task_group(event
, parent
, parent_ctx
,
6677 child
, ctxn
, &inherited_all
);
6682 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
6683 parent_ctx
->rotate_disable
= 0;
6685 child_ctx
= child
->perf_event_ctxp
[ctxn
];
6687 if (child_ctx
&& inherited_all
) {
6689 * Mark the child context as a clone of the parent
6690 * context, or of whatever the parent is a clone of.
6692 * Note that if the parent is a clone, the holding of
6693 * parent_ctx->lock avoids it from being uncloned.
6695 cloned_ctx
= parent_ctx
->parent_ctx
;
6697 child_ctx
->parent_ctx
= cloned_ctx
;
6698 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
6700 child_ctx
->parent_ctx
= parent_ctx
;
6701 child_ctx
->parent_gen
= parent_ctx
->generation
;
6703 get_ctx(child_ctx
->parent_ctx
);
6706 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
6707 mutex_unlock(&parent_ctx
->mutex
);
6709 perf_unpin_context(parent_ctx
);
6710 put_ctx(parent_ctx
);
6716 * Initialize the perf_event context in task_struct
6718 int perf_event_init_task(struct task_struct
*child
)
6722 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
6723 mutex_init(&child
->perf_event_mutex
);
6724 INIT_LIST_HEAD(&child
->perf_event_list
);
6726 for_each_task_context_nr(ctxn
) {
6727 ret
= perf_event_init_context(child
, ctxn
);
6735 static void __init
perf_event_init_all_cpus(void)
6737 struct swevent_htable
*swhash
;
6740 for_each_possible_cpu(cpu
) {
6741 swhash
= &per_cpu(swevent_htable
, cpu
);
6742 mutex_init(&swhash
->hlist_mutex
);
6743 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
6747 static void __cpuinit
perf_event_init_cpu(int cpu
)
6749 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6751 mutex_lock(&swhash
->hlist_mutex
);
6752 if (swhash
->hlist_refcount
> 0) {
6753 struct swevent_hlist
*hlist
;
6755 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
6757 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6759 mutex_unlock(&swhash
->hlist_mutex
);
6762 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
6763 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
6765 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
6767 WARN_ON(!irqs_disabled());
6769 list_del_init(&cpuctx
->rotation_list
);
6772 static void __perf_event_exit_context(void *__info
)
6774 struct perf_event_context
*ctx
= __info
;
6775 struct perf_event
*event
, *tmp
;
6777 perf_pmu_rotate_stop(ctx
->pmu
);
6779 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
, group_entry
)
6780 __perf_remove_from_context(event
);
6781 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
, group_entry
)
6782 __perf_remove_from_context(event
);
6785 static void perf_event_exit_cpu_context(int cpu
)
6787 struct perf_event_context
*ctx
;
6791 idx
= srcu_read_lock(&pmus_srcu
);
6792 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6793 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
6795 mutex_lock(&ctx
->mutex
);
6796 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
6797 mutex_unlock(&ctx
->mutex
);
6799 srcu_read_unlock(&pmus_srcu
, idx
);
6802 static void perf_event_exit_cpu(int cpu
)
6804 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6806 mutex_lock(&swhash
->hlist_mutex
);
6807 swevent_hlist_release(swhash
);
6808 mutex_unlock(&swhash
->hlist_mutex
);
6810 perf_event_exit_cpu_context(cpu
);
6813 static inline void perf_event_exit_cpu(int cpu
) { }
6817 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
6821 for_each_online_cpu(cpu
)
6822 perf_event_exit_cpu(cpu
);
6828 * Run the perf reboot notifier at the very last possible moment so that
6829 * the generic watchdog code runs as long as possible.
6831 static struct notifier_block perf_reboot_notifier
= {
6832 .notifier_call
= perf_reboot
,
6833 .priority
= INT_MIN
,
6836 static int __cpuinit
6837 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
6839 unsigned int cpu
= (long)hcpu
;
6841 switch (action
& ~CPU_TASKS_FROZEN
) {
6843 case CPU_UP_PREPARE
:
6844 case CPU_DOWN_FAILED
:
6845 perf_event_init_cpu(cpu
);
6848 case CPU_UP_CANCELED
:
6849 case CPU_DOWN_PREPARE
:
6850 perf_event_exit_cpu(cpu
);
6860 void __init
perf_event_init(void)
6866 perf_event_init_all_cpus();
6867 init_srcu_struct(&pmus_srcu
);
6868 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
6869 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
6870 perf_pmu_register(&perf_task_clock
, NULL
, -1);
6872 perf_cpu_notifier(perf_cpu_notify
);
6873 register_reboot_notifier(&perf_reboot_notifier
);
6875 ret
= init_hw_breakpoint();
6876 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
6879 static int __init
perf_event_sysfs_init(void)
6884 mutex_lock(&pmus_lock
);
6886 ret
= bus_register(&pmu_bus
);
6890 list_for_each_entry(pmu
, &pmus
, entry
) {
6891 if (!pmu
->name
|| pmu
->type
< 0)
6894 ret
= pmu_dev_alloc(pmu
);
6895 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
6897 pmu_bus_running
= 1;
6901 mutex_unlock(&pmus_lock
);
6905 device_initcall(perf_event_sysfs_init
);
6907 #ifdef CONFIG_CGROUP_PERF
6908 static struct cgroup_subsys_state
*perf_cgroup_create(
6909 struct cgroup_subsys
*ss
, struct cgroup
*cont
)
6911 struct perf_cgroup
*jc
;
6913 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
6915 return ERR_PTR(-ENOMEM
);
6917 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
6920 return ERR_PTR(-ENOMEM
);
6926 static void perf_cgroup_destroy(struct cgroup_subsys
*ss
,
6927 struct cgroup
*cont
)
6929 struct perf_cgroup
*jc
;
6930 jc
= container_of(cgroup_subsys_state(cont
, perf_subsys_id
),
6931 struct perf_cgroup
, css
);
6932 free_percpu(jc
->info
);
6936 static int __perf_cgroup_move(void *info
)
6938 struct task_struct
*task
= info
;
6939 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
6944 perf_cgroup_attach_task(struct cgroup
*cgrp
, struct task_struct
*task
)
6946 task_function_call(task
, __perf_cgroup_move
, task
);
6949 static void perf_cgroup_exit(struct cgroup_subsys
*ss
, struct cgroup
*cgrp
,
6950 struct cgroup
*old_cgrp
, struct task_struct
*task
)
6953 * cgroup_exit() is called in the copy_process() failure path.
6954 * Ignore this case since the task hasn't ran yet, this avoids
6955 * trying to poke a half freed task state from generic code.
6957 if (!(task
->flags
& PF_EXITING
))
6960 perf_cgroup_attach_task(cgrp
, task
);
6963 struct cgroup_subsys perf_subsys
= {
6964 .name
= "perf_event",
6965 .subsys_id
= perf_subsys_id
,
6966 .create
= perf_cgroup_create
,
6967 .destroy
= perf_cgroup_destroy
,
6968 .exit
= perf_cgroup_exit
,
6969 .attach_task
= perf_cgroup_attach_task
,
6971 #endif /* CONFIG_CGROUP_PERF */