2 * Performance events core code:
4 * Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
5 * Copyright (C) 2008-2011 Red Hat, Inc., Ingo Molnar
6 * Copyright (C) 2008-2011 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
7 * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
9 * For licensing details see kernel-base/COPYING
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <linux/idr.h>
17 #include <linux/file.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/hash.h>
21 #include <linux/tick.h>
22 #include <linux/sysfs.h>
23 #include <linux/dcache.h>
24 #include <linux/percpu.h>
25 #include <linux/ptrace.h>
26 #include <linux/reboot.h>
27 #include <linux/vmstat.h>
28 #include <linux/device.h>
29 #include <linux/export.h>
30 #include <linux/vmalloc.h>
31 #include <linux/hardirq.h>
32 #include <linux/rculist.h>
33 #include <linux/uaccess.h>
34 #include <linux/syscalls.h>
35 #include <linux/anon_inodes.h>
36 #include <linux/kernel_stat.h>
37 #include <linux/perf_event.h>
38 #include <linux/ftrace_event.h>
39 #include <linux/hw_breakpoint.h>
40 #include <linux/mm_types.h>
41 #include <linux/cgroup.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
48 #include <asm/irq_regs.h>
50 struct remote_function_call
{
51 struct task_struct
*p
;
52 int (*func
)(void *info
);
57 static void remote_function(void *data
)
59 struct remote_function_call
*tfc
= data
;
60 struct task_struct
*p
= tfc
->p
;
64 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
68 tfc
->ret
= tfc
->func(tfc
->info
);
72 * task_function_call - call a function on the cpu on which a task runs
73 * @p: the task to evaluate
74 * @func: the function to be called
75 * @info: the function call argument
77 * Calls the function @func when the task is currently running. This might
78 * be on the current CPU, which just calls the function directly
80 * returns: @func return value, or
81 * -ESRCH - when the process isn't running
82 * -EAGAIN - when the process moved away
85 task_function_call(struct task_struct
*p
, int (*func
) (void *info
), void *info
)
87 struct remote_function_call data
= {
91 .ret
= -ESRCH
, /* No such (running) process */
95 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
101 * cpu_function_call - call a function on the cpu
102 * @func: the function to be called
103 * @info: the function call argument
105 * Calls the function @func on the remote cpu.
107 * returns: @func return value or -ENXIO when the cpu is offline
109 static int cpu_function_call(int cpu
, int (*func
) (void *info
), void *info
)
111 struct remote_function_call data
= {
115 .ret
= -ENXIO
, /* No such CPU */
118 smp_call_function_single(cpu
, remote_function
, &data
, 1);
123 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
124 PERF_FLAG_FD_OUTPUT |\
125 PERF_FLAG_PID_CGROUP |\
126 PERF_FLAG_FD_CLOEXEC)
129 * branch priv levels that need permission checks
131 #define PERF_SAMPLE_BRANCH_PERM_PLM \
132 (PERF_SAMPLE_BRANCH_KERNEL |\
133 PERF_SAMPLE_BRANCH_HV)
136 EVENT_FLEXIBLE
= 0x1,
138 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
142 * perf_sched_events : >0 events exist
143 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
145 struct static_key_deferred perf_sched_events __read_mostly
;
146 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
147 static DEFINE_PER_CPU(atomic_t
, perf_branch_stack_events
);
149 static atomic_t nr_mmap_events __read_mostly
;
150 static atomic_t nr_comm_events __read_mostly
;
151 static atomic_t nr_task_events __read_mostly
;
152 static atomic_t nr_freq_events __read_mostly
;
154 static LIST_HEAD(pmus
);
155 static DEFINE_MUTEX(pmus_lock
);
156 static struct srcu_struct pmus_srcu
;
159 * perf event paranoia level:
160 * -1 - not paranoid at all
161 * 0 - disallow raw tracepoint access for unpriv
162 * 1 - disallow cpu events for unpriv
163 * 2 - disallow kernel profiling for unpriv
165 int sysctl_perf_event_paranoid __read_mostly
= 1;
167 /* Minimum for 512 kiB + 1 user control page */
168 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
171 * max perf event sample rate
173 #define DEFAULT_MAX_SAMPLE_RATE 100000
174 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
175 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
177 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
179 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
180 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
182 static int perf_sample_allowed_ns __read_mostly
=
183 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
185 void update_perf_cpu_limits(void)
187 u64 tmp
= perf_sample_period_ns
;
189 tmp
*= sysctl_perf_cpu_time_max_percent
;
191 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
194 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
196 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
197 void __user
*buffer
, size_t *lenp
,
200 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
205 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
206 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
207 update_perf_cpu_limits();
212 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
214 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
215 void __user
*buffer
, size_t *lenp
,
218 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
223 update_perf_cpu_limits();
229 * perf samples are done in some very critical code paths (NMIs).
230 * If they take too much CPU time, the system can lock up and not
231 * get any real work done. This will drop the sample rate when
232 * we detect that events are taking too long.
234 #define NR_ACCUMULATED_SAMPLES 128
235 static DEFINE_PER_CPU(u64
, running_sample_length
);
237 static void perf_duration_warn(struct irq_work
*w
)
239 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
240 u64 avg_local_sample_len
;
241 u64 local_samples_len
;
243 local_samples_len
= __get_cpu_var(running_sample_length
);
244 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
246 printk_ratelimited(KERN_WARNING
247 "perf interrupt took too long (%lld > %lld), lowering "
248 "kernel.perf_event_max_sample_rate to %d\n",
249 avg_local_sample_len
, allowed_ns
>> 1,
250 sysctl_perf_event_sample_rate
);
253 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
255 void perf_sample_event_took(u64 sample_len_ns
)
257 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
258 u64 avg_local_sample_len
;
259 u64 local_samples_len
;
264 /* decay the counter by 1 average sample */
265 local_samples_len
= __get_cpu_var(running_sample_length
);
266 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
267 local_samples_len
+= sample_len_ns
;
268 __get_cpu_var(running_sample_length
) = local_samples_len
;
271 * note: this will be biased artifically low until we have
272 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
273 * from having to maintain a count.
275 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
277 if (avg_local_sample_len
<= allowed_ns
)
280 if (max_samples_per_tick
<= 1)
283 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
284 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
285 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
287 update_perf_cpu_limits();
289 if (!irq_work_queue(&perf_duration_work
)) {
290 early_printk("perf interrupt took too long (%lld > %lld), lowering "
291 "kernel.perf_event_max_sample_rate to %d\n",
292 avg_local_sample_len
, allowed_ns
>> 1,
293 sysctl_perf_event_sample_rate
);
297 static atomic64_t perf_event_id
;
299 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
300 enum event_type_t event_type
);
302 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
303 enum event_type_t event_type
,
304 struct task_struct
*task
);
306 static void update_context_time(struct perf_event_context
*ctx
);
307 static u64
perf_event_time(struct perf_event
*event
);
309 void __weak
perf_event_print_debug(void) { }
311 extern __weak
const char *perf_pmu_name(void)
316 static inline u64
perf_clock(void)
318 return local_clock();
321 static inline struct perf_cpu_context
*
322 __get_cpu_context(struct perf_event_context
*ctx
)
324 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
327 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
328 struct perf_event_context
*ctx
)
330 raw_spin_lock(&cpuctx
->ctx
.lock
);
332 raw_spin_lock(&ctx
->lock
);
335 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
336 struct perf_event_context
*ctx
)
339 raw_spin_unlock(&ctx
->lock
);
340 raw_spin_unlock(&cpuctx
->ctx
.lock
);
343 #ifdef CONFIG_CGROUP_PERF
346 * perf_cgroup_info keeps track of time_enabled for a cgroup.
347 * This is a per-cpu dynamically allocated data structure.
349 struct perf_cgroup_info
{
355 struct cgroup_subsys_state css
;
356 struct perf_cgroup_info __percpu
*info
;
360 * Must ensure cgroup is pinned (css_get) before calling
361 * this function. In other words, we cannot call this function
362 * if there is no cgroup event for the current CPU context.
364 static inline struct perf_cgroup
*
365 perf_cgroup_from_task(struct task_struct
*task
)
367 return container_of(task_css(task
, perf_event_cgrp_id
),
368 struct perf_cgroup
, css
);
372 perf_cgroup_match(struct perf_event
*event
)
374 struct perf_event_context
*ctx
= event
->ctx
;
375 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
377 /* @event doesn't care about cgroup */
381 /* wants specific cgroup scope but @cpuctx isn't associated with any */
386 * Cgroup scoping is recursive. An event enabled for a cgroup is
387 * also enabled for all its descendant cgroups. If @cpuctx's
388 * cgroup is a descendant of @event's (the test covers identity
389 * case), it's a match.
391 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
392 event
->cgrp
->css
.cgroup
);
395 static inline void perf_put_cgroup(struct perf_event
*event
)
397 css_put(&event
->cgrp
->css
);
400 static inline void perf_detach_cgroup(struct perf_event
*event
)
402 perf_put_cgroup(event
);
406 static inline int is_cgroup_event(struct perf_event
*event
)
408 return event
->cgrp
!= NULL
;
411 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
413 struct perf_cgroup_info
*t
;
415 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
419 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
421 struct perf_cgroup_info
*info
;
426 info
= this_cpu_ptr(cgrp
->info
);
428 info
->time
+= now
- info
->timestamp
;
429 info
->timestamp
= now
;
432 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
434 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
436 __update_cgrp_time(cgrp_out
);
439 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
441 struct perf_cgroup
*cgrp
;
444 * ensure we access cgroup data only when needed and
445 * when we know the cgroup is pinned (css_get)
447 if (!is_cgroup_event(event
))
450 cgrp
= perf_cgroup_from_task(current
);
452 * Do not update time when cgroup is not active
454 if (cgrp
== event
->cgrp
)
455 __update_cgrp_time(event
->cgrp
);
459 perf_cgroup_set_timestamp(struct task_struct
*task
,
460 struct perf_event_context
*ctx
)
462 struct perf_cgroup
*cgrp
;
463 struct perf_cgroup_info
*info
;
466 * ctx->lock held by caller
467 * ensure we do not access cgroup data
468 * unless we have the cgroup pinned (css_get)
470 if (!task
|| !ctx
->nr_cgroups
)
473 cgrp
= perf_cgroup_from_task(task
);
474 info
= this_cpu_ptr(cgrp
->info
);
475 info
->timestamp
= ctx
->timestamp
;
478 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
479 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
482 * reschedule events based on the cgroup constraint of task.
484 * mode SWOUT : schedule out everything
485 * mode SWIN : schedule in based on cgroup for next
487 void perf_cgroup_switch(struct task_struct
*task
, int mode
)
489 struct perf_cpu_context
*cpuctx
;
494 * disable interrupts to avoid geting nr_cgroup
495 * changes via __perf_event_disable(). Also
498 local_irq_save(flags
);
501 * we reschedule only in the presence of cgroup
502 * constrained events.
506 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
507 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
508 if (cpuctx
->unique_pmu
!= pmu
)
509 continue; /* ensure we process each cpuctx once */
512 * perf_cgroup_events says at least one
513 * context on this CPU has cgroup events.
515 * ctx->nr_cgroups reports the number of cgroup
516 * events for a context.
518 if (cpuctx
->ctx
.nr_cgroups
> 0) {
519 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
520 perf_pmu_disable(cpuctx
->ctx
.pmu
);
522 if (mode
& PERF_CGROUP_SWOUT
) {
523 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
525 * must not be done before ctxswout due
526 * to event_filter_match() in event_sched_out()
531 if (mode
& PERF_CGROUP_SWIN
) {
532 WARN_ON_ONCE(cpuctx
->cgrp
);
534 * set cgrp before ctxsw in to allow
535 * event_filter_match() to not have to pass
538 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
539 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
541 perf_pmu_enable(cpuctx
->ctx
.pmu
);
542 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
548 local_irq_restore(flags
);
551 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
552 struct task_struct
*next
)
554 struct perf_cgroup
*cgrp1
;
555 struct perf_cgroup
*cgrp2
= NULL
;
558 * we come here when we know perf_cgroup_events > 0
560 cgrp1
= perf_cgroup_from_task(task
);
563 * next is NULL when called from perf_event_enable_on_exec()
564 * that will systematically cause a cgroup_switch()
567 cgrp2
= perf_cgroup_from_task(next
);
570 * only schedule out current cgroup events if we know
571 * that we are switching to a different cgroup. Otherwise,
572 * do no touch the cgroup events.
575 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
578 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
579 struct task_struct
*task
)
581 struct perf_cgroup
*cgrp1
;
582 struct perf_cgroup
*cgrp2
= NULL
;
585 * we come here when we know perf_cgroup_events > 0
587 cgrp1
= perf_cgroup_from_task(task
);
589 /* prev can never be NULL */
590 cgrp2
= perf_cgroup_from_task(prev
);
593 * only need to schedule in cgroup events if we are changing
594 * cgroup during ctxsw. Cgroup events were not scheduled
595 * out of ctxsw out if that was not the case.
598 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
601 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
602 struct perf_event_attr
*attr
,
603 struct perf_event
*group_leader
)
605 struct perf_cgroup
*cgrp
;
606 struct cgroup_subsys_state
*css
;
607 struct fd f
= fdget(fd
);
613 css
= css_tryget_online_from_dir(f
.file
->f_dentry
,
614 &perf_event_cgrp_subsys
);
620 cgrp
= container_of(css
, struct perf_cgroup
, css
);
624 * all events in a group must monitor
625 * the same cgroup because a task belongs
626 * to only one perf cgroup at a time
628 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
629 perf_detach_cgroup(event
);
638 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
640 struct perf_cgroup_info
*t
;
641 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
642 event
->shadow_ctx_time
= now
- t
->timestamp
;
646 perf_cgroup_defer_enabled(struct perf_event
*event
)
649 * when the current task's perf cgroup does not match
650 * the event's, we need to remember to call the
651 * perf_mark_enable() function the first time a task with
652 * a matching perf cgroup is scheduled in.
654 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
655 event
->cgrp_defer_enabled
= 1;
659 perf_cgroup_mark_enabled(struct perf_event
*event
,
660 struct perf_event_context
*ctx
)
662 struct perf_event
*sub
;
663 u64 tstamp
= perf_event_time(event
);
665 if (!event
->cgrp_defer_enabled
)
668 event
->cgrp_defer_enabled
= 0;
670 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
671 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
672 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
673 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
674 sub
->cgrp_defer_enabled
= 0;
678 #else /* !CONFIG_CGROUP_PERF */
681 perf_cgroup_match(struct perf_event
*event
)
686 static inline void perf_detach_cgroup(struct perf_event
*event
)
689 static inline int is_cgroup_event(struct perf_event
*event
)
694 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
699 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
703 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
707 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
708 struct task_struct
*next
)
712 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
713 struct task_struct
*task
)
717 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
718 struct perf_event_attr
*attr
,
719 struct perf_event
*group_leader
)
725 perf_cgroup_set_timestamp(struct task_struct
*task
,
726 struct perf_event_context
*ctx
)
731 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
736 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
740 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
746 perf_cgroup_defer_enabled(struct perf_event
*event
)
751 perf_cgroup_mark_enabled(struct perf_event
*event
,
752 struct perf_event_context
*ctx
)
758 * set default to be dependent on timer tick just
761 #define PERF_CPU_HRTIMER (1000 / HZ)
763 * function must be called with interrupts disbled
765 static enum hrtimer_restart
perf_cpu_hrtimer_handler(struct hrtimer
*hr
)
767 struct perf_cpu_context
*cpuctx
;
768 enum hrtimer_restart ret
= HRTIMER_NORESTART
;
771 WARN_ON(!irqs_disabled());
773 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
775 rotations
= perf_rotate_context(cpuctx
);
778 * arm timer if needed
781 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
782 ret
= HRTIMER_RESTART
;
788 /* CPU is going down */
789 void perf_cpu_hrtimer_cancel(int cpu
)
791 struct perf_cpu_context
*cpuctx
;
795 if (WARN_ON(cpu
!= smp_processor_id()))
798 local_irq_save(flags
);
802 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
803 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
805 if (pmu
->task_ctx_nr
== perf_sw_context
)
808 hrtimer_cancel(&cpuctx
->hrtimer
);
813 local_irq_restore(flags
);
816 static void __perf_cpu_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
818 struct hrtimer
*hr
= &cpuctx
->hrtimer
;
819 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
822 /* no multiplexing needed for SW PMU */
823 if (pmu
->task_ctx_nr
== perf_sw_context
)
827 * check default is sane, if not set then force to
828 * default interval (1/tick)
830 timer
= pmu
->hrtimer_interval_ms
;
832 timer
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
834 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
836 hrtimer_init(hr
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL_PINNED
);
837 hr
->function
= perf_cpu_hrtimer_handler
;
840 static void perf_cpu_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
842 struct hrtimer
*hr
= &cpuctx
->hrtimer
;
843 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
846 if (pmu
->task_ctx_nr
== perf_sw_context
)
849 if (hrtimer_active(hr
))
852 if (!hrtimer_callback_running(hr
))
853 __hrtimer_start_range_ns(hr
, cpuctx
->hrtimer_interval
,
854 0, HRTIMER_MODE_REL_PINNED
, 0);
857 void perf_pmu_disable(struct pmu
*pmu
)
859 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
861 pmu
->pmu_disable(pmu
);
864 void perf_pmu_enable(struct pmu
*pmu
)
866 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
868 pmu
->pmu_enable(pmu
);
871 static DEFINE_PER_CPU(struct list_head
, rotation_list
);
874 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
875 * because they're strictly cpu affine and rotate_start is called with IRQs
876 * disabled, while rotate_context is called from IRQ context.
878 static void perf_pmu_rotate_start(struct pmu
*pmu
)
880 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
881 struct list_head
*head
= &__get_cpu_var(rotation_list
);
883 WARN_ON(!irqs_disabled());
885 if (list_empty(&cpuctx
->rotation_list
))
886 list_add(&cpuctx
->rotation_list
, head
);
889 static void get_ctx(struct perf_event_context
*ctx
)
891 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
894 static void put_ctx(struct perf_event_context
*ctx
)
896 if (atomic_dec_and_test(&ctx
->refcount
)) {
898 put_ctx(ctx
->parent_ctx
);
900 put_task_struct(ctx
->task
);
901 kfree_rcu(ctx
, rcu_head
);
905 static void unclone_ctx(struct perf_event_context
*ctx
)
907 if (ctx
->parent_ctx
) {
908 put_ctx(ctx
->parent_ctx
);
909 ctx
->parent_ctx
= NULL
;
914 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
917 * only top level events have the pid namespace they were created in
920 event
= event
->parent
;
922 return task_tgid_nr_ns(p
, event
->ns
);
925 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
928 * only top level events have the pid namespace they were created in
931 event
= event
->parent
;
933 return task_pid_nr_ns(p
, event
->ns
);
937 * If we inherit events we want to return the parent event id
940 static u64
primary_event_id(struct perf_event
*event
)
945 id
= event
->parent
->id
;
951 * Get the perf_event_context for a task and lock it.
952 * This has to cope with with the fact that until it is locked,
953 * the context could get moved to another task.
955 static struct perf_event_context
*
956 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
958 struct perf_event_context
*ctx
;
962 * One of the few rules of preemptible RCU is that one cannot do
963 * rcu_read_unlock() while holding a scheduler (or nested) lock when
964 * part of the read side critical section was preemptible -- see
965 * rcu_read_unlock_special().
967 * Since ctx->lock nests under rq->lock we must ensure the entire read
968 * side critical section is non-preemptible.
972 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
975 * If this context is a clone of another, it might
976 * get swapped for another underneath us by
977 * perf_event_task_sched_out, though the
978 * rcu_read_lock() protects us from any context
979 * getting freed. Lock the context and check if it
980 * got swapped before we could get the lock, and retry
981 * if so. If we locked the right context, then it
982 * can't get swapped on us any more.
984 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
985 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
986 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
992 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
993 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
1003 * Get the context for a task and increment its pin_count so it
1004 * can't get swapped to another task. This also increments its
1005 * reference count so that the context can't get freed.
1007 static struct perf_event_context
*
1008 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1010 struct perf_event_context
*ctx
;
1011 unsigned long flags
;
1013 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1016 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1021 static void perf_unpin_context(struct perf_event_context
*ctx
)
1023 unsigned long flags
;
1025 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1027 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1031 * Update the record of the current time in a context.
1033 static void update_context_time(struct perf_event_context
*ctx
)
1035 u64 now
= perf_clock();
1037 ctx
->time
+= now
- ctx
->timestamp
;
1038 ctx
->timestamp
= now
;
1041 static u64
perf_event_time(struct perf_event
*event
)
1043 struct perf_event_context
*ctx
= event
->ctx
;
1045 if (is_cgroup_event(event
))
1046 return perf_cgroup_event_time(event
);
1048 return ctx
? ctx
->time
: 0;
1052 * Update the total_time_enabled and total_time_running fields for a event.
1053 * The caller of this function needs to hold the ctx->lock.
1055 static void update_event_times(struct perf_event
*event
)
1057 struct perf_event_context
*ctx
= event
->ctx
;
1060 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1061 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1064 * in cgroup mode, time_enabled represents
1065 * the time the event was enabled AND active
1066 * tasks were in the monitored cgroup. This is
1067 * independent of the activity of the context as
1068 * there may be a mix of cgroup and non-cgroup events.
1070 * That is why we treat cgroup events differently
1073 if (is_cgroup_event(event
))
1074 run_end
= perf_cgroup_event_time(event
);
1075 else if (ctx
->is_active
)
1076 run_end
= ctx
->time
;
1078 run_end
= event
->tstamp_stopped
;
1080 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1082 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1083 run_end
= event
->tstamp_stopped
;
1085 run_end
= perf_event_time(event
);
1087 event
->total_time_running
= run_end
- event
->tstamp_running
;
1092 * Update total_time_enabled and total_time_running for all events in a group.
1094 static void update_group_times(struct perf_event
*leader
)
1096 struct perf_event
*event
;
1098 update_event_times(leader
);
1099 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1100 update_event_times(event
);
1103 static struct list_head
*
1104 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1106 if (event
->attr
.pinned
)
1107 return &ctx
->pinned_groups
;
1109 return &ctx
->flexible_groups
;
1113 * Add a event from the lists for its context.
1114 * Must be called with ctx->mutex and ctx->lock held.
1117 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1119 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1120 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1123 * If we're a stand alone event or group leader, we go to the context
1124 * list, group events are kept attached to the group so that
1125 * perf_group_detach can, at all times, locate all siblings.
1127 if (event
->group_leader
== event
) {
1128 struct list_head
*list
;
1130 if (is_software_event(event
))
1131 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1133 list
= ctx_group_list(event
, ctx
);
1134 list_add_tail(&event
->group_entry
, list
);
1137 if (is_cgroup_event(event
))
1140 if (has_branch_stack(event
))
1141 ctx
->nr_branch_stack
++;
1143 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1144 if (!ctx
->nr_events
)
1145 perf_pmu_rotate_start(ctx
->pmu
);
1147 if (event
->attr
.inherit_stat
)
1154 * Initialize event state based on the perf_event_attr::disabled.
1156 static inline void perf_event__state_init(struct perf_event
*event
)
1158 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1159 PERF_EVENT_STATE_INACTIVE
;
1163 * Called at perf_event creation and when events are attached/detached from a
1166 static void perf_event__read_size(struct perf_event
*event
)
1168 int entry
= sizeof(u64
); /* value */
1172 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1173 size
+= sizeof(u64
);
1175 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1176 size
+= sizeof(u64
);
1178 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1179 entry
+= sizeof(u64
);
1181 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1182 nr
+= event
->group_leader
->nr_siblings
;
1183 size
+= sizeof(u64
);
1187 event
->read_size
= size
;
1190 static void perf_event__header_size(struct perf_event
*event
)
1192 struct perf_sample_data
*data
;
1193 u64 sample_type
= event
->attr
.sample_type
;
1196 perf_event__read_size(event
);
1198 if (sample_type
& PERF_SAMPLE_IP
)
1199 size
+= sizeof(data
->ip
);
1201 if (sample_type
& PERF_SAMPLE_ADDR
)
1202 size
+= sizeof(data
->addr
);
1204 if (sample_type
& PERF_SAMPLE_PERIOD
)
1205 size
+= sizeof(data
->period
);
1207 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1208 size
+= sizeof(data
->weight
);
1210 if (sample_type
& PERF_SAMPLE_READ
)
1211 size
+= event
->read_size
;
1213 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1214 size
+= sizeof(data
->data_src
.val
);
1216 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1217 size
+= sizeof(data
->txn
);
1219 event
->header_size
= size
;
1222 static void perf_event__id_header_size(struct perf_event
*event
)
1224 struct perf_sample_data
*data
;
1225 u64 sample_type
= event
->attr
.sample_type
;
1228 if (sample_type
& PERF_SAMPLE_TID
)
1229 size
+= sizeof(data
->tid_entry
);
1231 if (sample_type
& PERF_SAMPLE_TIME
)
1232 size
+= sizeof(data
->time
);
1234 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1235 size
+= sizeof(data
->id
);
1237 if (sample_type
& PERF_SAMPLE_ID
)
1238 size
+= sizeof(data
->id
);
1240 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1241 size
+= sizeof(data
->stream_id
);
1243 if (sample_type
& PERF_SAMPLE_CPU
)
1244 size
+= sizeof(data
->cpu_entry
);
1246 event
->id_header_size
= size
;
1249 static void perf_group_attach(struct perf_event
*event
)
1251 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1254 * We can have double attach due to group movement in perf_event_open.
1256 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1259 event
->attach_state
|= PERF_ATTACH_GROUP
;
1261 if (group_leader
== event
)
1264 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1265 !is_software_event(event
))
1266 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1268 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1269 group_leader
->nr_siblings
++;
1271 perf_event__header_size(group_leader
);
1273 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1274 perf_event__header_size(pos
);
1278 * Remove a event from the lists for its context.
1279 * Must be called with ctx->mutex and ctx->lock held.
1282 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1284 struct perf_cpu_context
*cpuctx
;
1286 * We can have double detach due to exit/hot-unplug + close.
1288 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1291 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1293 if (is_cgroup_event(event
)) {
1295 cpuctx
= __get_cpu_context(ctx
);
1297 * if there are no more cgroup events
1298 * then cler cgrp to avoid stale pointer
1299 * in update_cgrp_time_from_cpuctx()
1301 if (!ctx
->nr_cgroups
)
1302 cpuctx
->cgrp
= NULL
;
1305 if (has_branch_stack(event
))
1306 ctx
->nr_branch_stack
--;
1309 if (event
->attr
.inherit_stat
)
1312 list_del_rcu(&event
->event_entry
);
1314 if (event
->group_leader
== event
)
1315 list_del_init(&event
->group_entry
);
1317 update_group_times(event
);
1320 * If event was in error state, then keep it
1321 * that way, otherwise bogus counts will be
1322 * returned on read(). The only way to get out
1323 * of error state is by explicit re-enabling
1326 if (event
->state
> PERF_EVENT_STATE_OFF
)
1327 event
->state
= PERF_EVENT_STATE_OFF
;
1332 static void perf_group_detach(struct perf_event
*event
)
1334 struct perf_event
*sibling
, *tmp
;
1335 struct list_head
*list
= NULL
;
1338 * We can have double detach due to exit/hot-unplug + close.
1340 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1343 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1346 * If this is a sibling, remove it from its group.
1348 if (event
->group_leader
!= event
) {
1349 list_del_init(&event
->group_entry
);
1350 event
->group_leader
->nr_siblings
--;
1354 if (!list_empty(&event
->group_entry
))
1355 list
= &event
->group_entry
;
1358 * If this was a group event with sibling events then
1359 * upgrade the siblings to singleton events by adding them
1360 * to whatever list we are on.
1362 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1364 list_move_tail(&sibling
->group_entry
, list
);
1365 sibling
->group_leader
= sibling
;
1367 /* Inherit group flags from the previous leader */
1368 sibling
->group_flags
= event
->group_flags
;
1372 perf_event__header_size(event
->group_leader
);
1374 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1375 perf_event__header_size(tmp
);
1379 event_filter_match(struct perf_event
*event
)
1381 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1382 && perf_cgroup_match(event
);
1386 event_sched_out(struct perf_event
*event
,
1387 struct perf_cpu_context
*cpuctx
,
1388 struct perf_event_context
*ctx
)
1390 u64 tstamp
= perf_event_time(event
);
1393 * An event which could not be activated because of
1394 * filter mismatch still needs to have its timings
1395 * maintained, otherwise bogus information is return
1396 * via read() for time_enabled, time_running:
1398 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1399 && !event_filter_match(event
)) {
1400 delta
= tstamp
- event
->tstamp_stopped
;
1401 event
->tstamp_running
+= delta
;
1402 event
->tstamp_stopped
= tstamp
;
1405 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1408 perf_pmu_disable(event
->pmu
);
1410 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1411 if (event
->pending_disable
) {
1412 event
->pending_disable
= 0;
1413 event
->state
= PERF_EVENT_STATE_OFF
;
1415 event
->tstamp_stopped
= tstamp
;
1416 event
->pmu
->del(event
, 0);
1419 if (!is_software_event(event
))
1420 cpuctx
->active_oncpu
--;
1422 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1424 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1425 cpuctx
->exclusive
= 0;
1427 perf_pmu_enable(event
->pmu
);
1431 group_sched_out(struct perf_event
*group_event
,
1432 struct perf_cpu_context
*cpuctx
,
1433 struct perf_event_context
*ctx
)
1435 struct perf_event
*event
;
1436 int state
= group_event
->state
;
1438 event_sched_out(group_event
, cpuctx
, ctx
);
1441 * Schedule out siblings (if any):
1443 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1444 event_sched_out(event
, cpuctx
, ctx
);
1446 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1447 cpuctx
->exclusive
= 0;
1450 struct remove_event
{
1451 struct perf_event
*event
;
1456 * Cross CPU call to remove a performance event
1458 * We disable the event on the hardware level first. After that we
1459 * remove it from the context list.
1461 static int __perf_remove_from_context(void *info
)
1463 struct remove_event
*re
= info
;
1464 struct perf_event
*event
= re
->event
;
1465 struct perf_event_context
*ctx
= event
->ctx
;
1466 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1468 raw_spin_lock(&ctx
->lock
);
1469 event_sched_out(event
, cpuctx
, ctx
);
1470 if (re
->detach_group
)
1471 perf_group_detach(event
);
1472 list_del_event(event
, ctx
);
1473 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1475 cpuctx
->task_ctx
= NULL
;
1477 raw_spin_unlock(&ctx
->lock
);
1484 * Remove the event from a task's (or a CPU's) list of events.
1486 * CPU events are removed with a smp call. For task events we only
1487 * call when the task is on a CPU.
1489 * If event->ctx is a cloned context, callers must make sure that
1490 * every task struct that event->ctx->task could possibly point to
1491 * remains valid. This is OK when called from perf_release since
1492 * that only calls us on the top-level context, which can't be a clone.
1493 * When called from perf_event_exit_task, it's OK because the
1494 * context has been detached from its task.
1496 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1498 struct perf_event_context
*ctx
= event
->ctx
;
1499 struct task_struct
*task
= ctx
->task
;
1500 struct remove_event re
= {
1502 .detach_group
= detach_group
,
1505 lockdep_assert_held(&ctx
->mutex
);
1509 * Per cpu events are removed via an smp call and
1510 * the removal is always successful.
1512 cpu_function_call(event
->cpu
, __perf_remove_from_context
, &re
);
1517 if (!task_function_call(task
, __perf_remove_from_context
, &re
))
1520 raw_spin_lock_irq(&ctx
->lock
);
1522 * If we failed to find a running task, but find the context active now
1523 * that we've acquired the ctx->lock, retry.
1525 if (ctx
->is_active
) {
1526 raw_spin_unlock_irq(&ctx
->lock
);
1531 * Since the task isn't running, its safe to remove the event, us
1532 * holding the ctx->lock ensures the task won't get scheduled in.
1535 perf_group_detach(event
);
1536 list_del_event(event
, ctx
);
1537 raw_spin_unlock_irq(&ctx
->lock
);
1541 * Cross CPU call to disable a performance event
1543 int __perf_event_disable(void *info
)
1545 struct perf_event
*event
= info
;
1546 struct perf_event_context
*ctx
= event
->ctx
;
1547 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1550 * If this is a per-task event, need to check whether this
1551 * event's task is the current task on this cpu.
1553 * Can trigger due to concurrent perf_event_context_sched_out()
1554 * flipping contexts around.
1556 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1559 raw_spin_lock(&ctx
->lock
);
1562 * If the event is on, turn it off.
1563 * If it is in error state, leave it in error state.
1565 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1566 update_context_time(ctx
);
1567 update_cgrp_time_from_event(event
);
1568 update_group_times(event
);
1569 if (event
== event
->group_leader
)
1570 group_sched_out(event
, cpuctx
, ctx
);
1572 event_sched_out(event
, cpuctx
, ctx
);
1573 event
->state
= PERF_EVENT_STATE_OFF
;
1576 raw_spin_unlock(&ctx
->lock
);
1584 * If event->ctx is a cloned context, callers must make sure that
1585 * every task struct that event->ctx->task could possibly point to
1586 * remains valid. This condition is satisifed when called through
1587 * perf_event_for_each_child or perf_event_for_each because they
1588 * hold the top-level event's child_mutex, so any descendant that
1589 * goes to exit will block in sync_child_event.
1590 * When called from perf_pending_event it's OK because event->ctx
1591 * is the current context on this CPU and preemption is disabled,
1592 * hence we can't get into perf_event_task_sched_out for this context.
1594 void perf_event_disable(struct perf_event
*event
)
1596 struct perf_event_context
*ctx
= event
->ctx
;
1597 struct task_struct
*task
= ctx
->task
;
1601 * Disable the event on the cpu that it's on
1603 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1608 if (!task_function_call(task
, __perf_event_disable
, event
))
1611 raw_spin_lock_irq(&ctx
->lock
);
1613 * If the event is still active, we need to retry the cross-call.
1615 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1616 raw_spin_unlock_irq(&ctx
->lock
);
1618 * Reload the task pointer, it might have been changed by
1619 * a concurrent perf_event_context_sched_out().
1626 * Since we have the lock this context can't be scheduled
1627 * in, so we can change the state safely.
1629 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1630 update_group_times(event
);
1631 event
->state
= PERF_EVENT_STATE_OFF
;
1633 raw_spin_unlock_irq(&ctx
->lock
);
1635 EXPORT_SYMBOL_GPL(perf_event_disable
);
1637 static void perf_set_shadow_time(struct perf_event
*event
,
1638 struct perf_event_context
*ctx
,
1642 * use the correct time source for the time snapshot
1644 * We could get by without this by leveraging the
1645 * fact that to get to this function, the caller
1646 * has most likely already called update_context_time()
1647 * and update_cgrp_time_xx() and thus both timestamp
1648 * are identical (or very close). Given that tstamp is,
1649 * already adjusted for cgroup, we could say that:
1650 * tstamp - ctx->timestamp
1652 * tstamp - cgrp->timestamp.
1654 * Then, in perf_output_read(), the calculation would
1655 * work with no changes because:
1656 * - event is guaranteed scheduled in
1657 * - no scheduled out in between
1658 * - thus the timestamp would be the same
1660 * But this is a bit hairy.
1662 * So instead, we have an explicit cgroup call to remain
1663 * within the time time source all along. We believe it
1664 * is cleaner and simpler to understand.
1666 if (is_cgroup_event(event
))
1667 perf_cgroup_set_shadow_time(event
, tstamp
);
1669 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1672 #define MAX_INTERRUPTS (~0ULL)
1674 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1677 event_sched_in(struct perf_event
*event
,
1678 struct perf_cpu_context
*cpuctx
,
1679 struct perf_event_context
*ctx
)
1681 u64 tstamp
= perf_event_time(event
);
1684 lockdep_assert_held(&ctx
->lock
);
1686 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1689 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1690 event
->oncpu
= smp_processor_id();
1693 * Unthrottle events, since we scheduled we might have missed several
1694 * ticks already, also for a heavily scheduling task there is little
1695 * guarantee it'll get a tick in a timely manner.
1697 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1698 perf_log_throttle(event
, 1);
1699 event
->hw
.interrupts
= 0;
1703 * The new state must be visible before we turn it on in the hardware:
1707 perf_pmu_disable(event
->pmu
);
1709 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1710 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1716 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1718 perf_set_shadow_time(event
, ctx
, tstamp
);
1720 if (!is_software_event(event
))
1721 cpuctx
->active_oncpu
++;
1723 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1726 if (event
->attr
.exclusive
)
1727 cpuctx
->exclusive
= 1;
1730 perf_pmu_enable(event
->pmu
);
1736 group_sched_in(struct perf_event
*group_event
,
1737 struct perf_cpu_context
*cpuctx
,
1738 struct perf_event_context
*ctx
)
1740 struct perf_event
*event
, *partial_group
= NULL
;
1741 struct pmu
*pmu
= ctx
->pmu
;
1742 u64 now
= ctx
->time
;
1743 bool simulate
= false;
1745 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1748 pmu
->start_txn(pmu
);
1750 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1751 pmu
->cancel_txn(pmu
);
1752 perf_cpu_hrtimer_restart(cpuctx
);
1757 * Schedule in siblings as one group (if any):
1759 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1760 if (event_sched_in(event
, cpuctx
, ctx
)) {
1761 partial_group
= event
;
1766 if (!pmu
->commit_txn(pmu
))
1771 * Groups can be scheduled in as one unit only, so undo any
1772 * partial group before returning:
1773 * The events up to the failed event are scheduled out normally,
1774 * tstamp_stopped will be updated.
1776 * The failed events and the remaining siblings need to have
1777 * their timings updated as if they had gone thru event_sched_in()
1778 * and event_sched_out(). This is required to get consistent timings
1779 * across the group. This also takes care of the case where the group
1780 * could never be scheduled by ensuring tstamp_stopped is set to mark
1781 * the time the event was actually stopped, such that time delta
1782 * calculation in update_event_times() is correct.
1784 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1785 if (event
== partial_group
)
1789 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1790 event
->tstamp_stopped
= now
;
1792 event_sched_out(event
, cpuctx
, ctx
);
1795 event_sched_out(group_event
, cpuctx
, ctx
);
1797 pmu
->cancel_txn(pmu
);
1799 perf_cpu_hrtimer_restart(cpuctx
);
1805 * Work out whether we can put this event group on the CPU now.
1807 static int group_can_go_on(struct perf_event
*event
,
1808 struct perf_cpu_context
*cpuctx
,
1812 * Groups consisting entirely of software events can always go on.
1814 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
1817 * If an exclusive group is already on, no other hardware
1820 if (cpuctx
->exclusive
)
1823 * If this group is exclusive and there are already
1824 * events on the CPU, it can't go on.
1826 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
1829 * Otherwise, try to add it if all previous groups were able
1835 static void add_event_to_ctx(struct perf_event
*event
,
1836 struct perf_event_context
*ctx
)
1838 u64 tstamp
= perf_event_time(event
);
1840 list_add_event(event
, ctx
);
1841 perf_group_attach(event
);
1842 event
->tstamp_enabled
= tstamp
;
1843 event
->tstamp_running
= tstamp
;
1844 event
->tstamp_stopped
= tstamp
;
1847 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
1849 ctx_sched_in(struct perf_event_context
*ctx
,
1850 struct perf_cpu_context
*cpuctx
,
1851 enum event_type_t event_type
,
1852 struct task_struct
*task
);
1854 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
1855 struct perf_event_context
*ctx
,
1856 struct task_struct
*task
)
1858 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
1860 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
1861 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
1863 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
1867 * Cross CPU call to install and enable a performance event
1869 * Must be called with ctx->mutex held
1871 static int __perf_install_in_context(void *info
)
1873 struct perf_event
*event
= info
;
1874 struct perf_event_context
*ctx
= event
->ctx
;
1875 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1876 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
1877 struct task_struct
*task
= current
;
1879 perf_ctx_lock(cpuctx
, task_ctx
);
1880 perf_pmu_disable(cpuctx
->ctx
.pmu
);
1883 * If there was an active task_ctx schedule it out.
1886 task_ctx_sched_out(task_ctx
);
1889 * If the context we're installing events in is not the
1890 * active task_ctx, flip them.
1892 if (ctx
->task
&& task_ctx
!= ctx
) {
1894 raw_spin_unlock(&task_ctx
->lock
);
1895 raw_spin_lock(&ctx
->lock
);
1900 cpuctx
->task_ctx
= task_ctx
;
1901 task
= task_ctx
->task
;
1904 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
1906 update_context_time(ctx
);
1908 * update cgrp time only if current cgrp
1909 * matches event->cgrp. Must be done before
1910 * calling add_event_to_ctx()
1912 update_cgrp_time_from_event(event
);
1914 add_event_to_ctx(event
, ctx
);
1917 * Schedule everything back in
1919 perf_event_sched_in(cpuctx
, task_ctx
, task
);
1921 perf_pmu_enable(cpuctx
->ctx
.pmu
);
1922 perf_ctx_unlock(cpuctx
, task_ctx
);
1928 * Attach a performance event to a context
1930 * First we add the event to the list with the hardware enable bit
1931 * in event->hw_config cleared.
1933 * If the event is attached to a task which is on a CPU we use a smp
1934 * call to enable it in the task context. The task might have been
1935 * scheduled away, but we check this in the smp call again.
1938 perf_install_in_context(struct perf_event_context
*ctx
,
1939 struct perf_event
*event
,
1942 struct task_struct
*task
= ctx
->task
;
1944 lockdep_assert_held(&ctx
->mutex
);
1947 if (event
->cpu
!= -1)
1952 * Per cpu events are installed via an smp call and
1953 * the install is always successful.
1955 cpu_function_call(cpu
, __perf_install_in_context
, event
);
1960 if (!task_function_call(task
, __perf_install_in_context
, event
))
1963 raw_spin_lock_irq(&ctx
->lock
);
1965 * If we failed to find a running task, but find the context active now
1966 * that we've acquired the ctx->lock, retry.
1968 if (ctx
->is_active
) {
1969 raw_spin_unlock_irq(&ctx
->lock
);
1974 * Since the task isn't running, its safe to add the event, us holding
1975 * the ctx->lock ensures the task won't get scheduled in.
1977 add_event_to_ctx(event
, ctx
);
1978 raw_spin_unlock_irq(&ctx
->lock
);
1982 * Put a event into inactive state and update time fields.
1983 * Enabling the leader of a group effectively enables all
1984 * the group members that aren't explicitly disabled, so we
1985 * have to update their ->tstamp_enabled also.
1986 * Note: this works for group members as well as group leaders
1987 * since the non-leader members' sibling_lists will be empty.
1989 static void __perf_event_mark_enabled(struct perf_event
*event
)
1991 struct perf_event
*sub
;
1992 u64 tstamp
= perf_event_time(event
);
1994 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1995 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
1996 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
1997 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
1998 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2003 * Cross CPU call to enable a performance event
2005 static int __perf_event_enable(void *info
)
2007 struct perf_event
*event
= info
;
2008 struct perf_event_context
*ctx
= event
->ctx
;
2009 struct perf_event
*leader
= event
->group_leader
;
2010 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2014 * There's a time window between 'ctx->is_active' check
2015 * in perf_event_enable function and this place having:
2017 * - ctx->lock unlocked
2019 * where the task could be killed and 'ctx' deactivated
2020 * by perf_event_exit_task.
2022 if (!ctx
->is_active
)
2025 raw_spin_lock(&ctx
->lock
);
2026 update_context_time(ctx
);
2028 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2032 * set current task's cgroup time reference point
2034 perf_cgroup_set_timestamp(current
, ctx
);
2036 __perf_event_mark_enabled(event
);
2038 if (!event_filter_match(event
)) {
2039 if (is_cgroup_event(event
))
2040 perf_cgroup_defer_enabled(event
);
2045 * If the event is in a group and isn't the group leader,
2046 * then don't put it on unless the group is on.
2048 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2051 if (!group_can_go_on(event
, cpuctx
, 1)) {
2054 if (event
== leader
)
2055 err
= group_sched_in(event
, cpuctx
, ctx
);
2057 err
= event_sched_in(event
, cpuctx
, ctx
);
2062 * If this event can't go on and it's part of a
2063 * group, then the whole group has to come off.
2065 if (leader
!= event
) {
2066 group_sched_out(leader
, cpuctx
, ctx
);
2067 perf_cpu_hrtimer_restart(cpuctx
);
2069 if (leader
->attr
.pinned
) {
2070 update_group_times(leader
);
2071 leader
->state
= PERF_EVENT_STATE_ERROR
;
2076 raw_spin_unlock(&ctx
->lock
);
2084 * If event->ctx is a cloned context, callers must make sure that
2085 * every task struct that event->ctx->task could possibly point to
2086 * remains valid. This condition is satisfied when called through
2087 * perf_event_for_each_child or perf_event_for_each as described
2088 * for perf_event_disable.
2090 void perf_event_enable(struct perf_event
*event
)
2092 struct perf_event_context
*ctx
= event
->ctx
;
2093 struct task_struct
*task
= ctx
->task
;
2097 * Enable the event on the cpu that it's on
2099 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
2103 raw_spin_lock_irq(&ctx
->lock
);
2104 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2108 * If the event is in error state, clear that first.
2109 * That way, if we see the event in error state below, we
2110 * know that it has gone back into error state, as distinct
2111 * from the task having been scheduled away before the
2112 * cross-call arrived.
2114 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2115 event
->state
= PERF_EVENT_STATE_OFF
;
2118 if (!ctx
->is_active
) {
2119 __perf_event_mark_enabled(event
);
2123 raw_spin_unlock_irq(&ctx
->lock
);
2125 if (!task_function_call(task
, __perf_event_enable
, event
))
2128 raw_spin_lock_irq(&ctx
->lock
);
2131 * If the context is active and the event is still off,
2132 * we need to retry the cross-call.
2134 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
2136 * task could have been flipped by a concurrent
2137 * perf_event_context_sched_out()
2144 raw_spin_unlock_irq(&ctx
->lock
);
2146 EXPORT_SYMBOL_GPL(perf_event_enable
);
2148 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2151 * not supported on inherited events
2153 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2156 atomic_add(refresh
, &event
->event_limit
);
2157 perf_event_enable(event
);
2161 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2163 static void ctx_sched_out(struct perf_event_context
*ctx
,
2164 struct perf_cpu_context
*cpuctx
,
2165 enum event_type_t event_type
)
2167 struct perf_event
*event
;
2168 int is_active
= ctx
->is_active
;
2170 ctx
->is_active
&= ~event_type
;
2171 if (likely(!ctx
->nr_events
))
2174 update_context_time(ctx
);
2175 update_cgrp_time_from_cpuctx(cpuctx
);
2176 if (!ctx
->nr_active
)
2179 perf_pmu_disable(ctx
->pmu
);
2180 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2181 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2182 group_sched_out(event
, cpuctx
, ctx
);
2185 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2186 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2187 group_sched_out(event
, cpuctx
, ctx
);
2189 perf_pmu_enable(ctx
->pmu
);
2193 * Test whether two contexts are equivalent, i.e. whether they have both been
2194 * cloned from the same version of the same context.
2196 * Equivalence is measured using a generation number in the context that is
2197 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2198 * and list_del_event().
2200 static int context_equiv(struct perf_event_context
*ctx1
,
2201 struct perf_event_context
*ctx2
)
2203 /* Pinning disables the swap optimization */
2204 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2207 /* If ctx1 is the parent of ctx2 */
2208 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2211 /* If ctx2 is the parent of ctx1 */
2212 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2216 * If ctx1 and ctx2 have the same parent; we flatten the parent
2217 * hierarchy, see perf_event_init_context().
2219 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2220 ctx1
->parent_gen
== ctx2
->parent_gen
)
2227 static void __perf_event_sync_stat(struct perf_event
*event
,
2228 struct perf_event
*next_event
)
2232 if (!event
->attr
.inherit_stat
)
2236 * Update the event value, we cannot use perf_event_read()
2237 * because we're in the middle of a context switch and have IRQs
2238 * disabled, which upsets smp_call_function_single(), however
2239 * we know the event must be on the current CPU, therefore we
2240 * don't need to use it.
2242 switch (event
->state
) {
2243 case PERF_EVENT_STATE_ACTIVE
:
2244 event
->pmu
->read(event
);
2247 case PERF_EVENT_STATE_INACTIVE
:
2248 update_event_times(event
);
2256 * In order to keep per-task stats reliable we need to flip the event
2257 * values when we flip the contexts.
2259 value
= local64_read(&next_event
->count
);
2260 value
= local64_xchg(&event
->count
, value
);
2261 local64_set(&next_event
->count
, value
);
2263 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2264 swap(event
->total_time_running
, next_event
->total_time_running
);
2267 * Since we swizzled the values, update the user visible data too.
2269 perf_event_update_userpage(event
);
2270 perf_event_update_userpage(next_event
);
2273 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2274 struct perf_event_context
*next_ctx
)
2276 struct perf_event
*event
, *next_event
;
2281 update_context_time(ctx
);
2283 event
= list_first_entry(&ctx
->event_list
,
2284 struct perf_event
, event_entry
);
2286 next_event
= list_first_entry(&next_ctx
->event_list
,
2287 struct perf_event
, event_entry
);
2289 while (&event
->event_entry
!= &ctx
->event_list
&&
2290 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2292 __perf_event_sync_stat(event
, next_event
);
2294 event
= list_next_entry(event
, event_entry
);
2295 next_event
= list_next_entry(next_event
, event_entry
);
2299 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2300 struct task_struct
*next
)
2302 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2303 struct perf_event_context
*next_ctx
;
2304 struct perf_event_context
*parent
, *next_parent
;
2305 struct perf_cpu_context
*cpuctx
;
2311 cpuctx
= __get_cpu_context(ctx
);
2312 if (!cpuctx
->task_ctx
)
2316 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2320 parent
= rcu_dereference(ctx
->parent_ctx
);
2321 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2323 /* If neither context have a parent context; they cannot be clones. */
2324 if (!parent
|| !next_parent
)
2327 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2329 * Looks like the two contexts are clones, so we might be
2330 * able to optimize the context switch. We lock both
2331 * contexts and check that they are clones under the
2332 * lock (including re-checking that neither has been
2333 * uncloned in the meantime). It doesn't matter which
2334 * order we take the locks because no other cpu could
2335 * be trying to lock both of these tasks.
2337 raw_spin_lock(&ctx
->lock
);
2338 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2339 if (context_equiv(ctx
, next_ctx
)) {
2341 * XXX do we need a memory barrier of sorts
2342 * wrt to rcu_dereference() of perf_event_ctxp
2344 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2345 next
->perf_event_ctxp
[ctxn
] = ctx
;
2347 next_ctx
->task
= task
;
2350 perf_event_sync_stat(ctx
, next_ctx
);
2352 raw_spin_unlock(&next_ctx
->lock
);
2353 raw_spin_unlock(&ctx
->lock
);
2359 raw_spin_lock(&ctx
->lock
);
2360 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2361 cpuctx
->task_ctx
= NULL
;
2362 raw_spin_unlock(&ctx
->lock
);
2366 #define for_each_task_context_nr(ctxn) \
2367 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2370 * Called from scheduler to remove the events of the current task,
2371 * with interrupts disabled.
2373 * We stop each event and update the event value in event->count.
2375 * This does not protect us against NMI, but disable()
2376 * sets the disabled bit in the control field of event _before_
2377 * accessing the event control register. If a NMI hits, then it will
2378 * not restart the event.
2380 void __perf_event_task_sched_out(struct task_struct
*task
,
2381 struct task_struct
*next
)
2385 for_each_task_context_nr(ctxn
)
2386 perf_event_context_sched_out(task
, ctxn
, next
);
2389 * if cgroup events exist on this CPU, then we need
2390 * to check if we have to switch out PMU state.
2391 * cgroup event are system-wide mode only
2393 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2394 perf_cgroup_sched_out(task
, next
);
2397 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2399 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2401 if (!cpuctx
->task_ctx
)
2404 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2407 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2408 cpuctx
->task_ctx
= NULL
;
2412 * Called with IRQs disabled
2414 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2415 enum event_type_t event_type
)
2417 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2421 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2422 struct perf_cpu_context
*cpuctx
)
2424 struct perf_event
*event
;
2426 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2427 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2429 if (!event_filter_match(event
))
2432 /* may need to reset tstamp_enabled */
2433 if (is_cgroup_event(event
))
2434 perf_cgroup_mark_enabled(event
, ctx
);
2436 if (group_can_go_on(event
, cpuctx
, 1))
2437 group_sched_in(event
, cpuctx
, ctx
);
2440 * If this pinned group hasn't been scheduled,
2441 * put it in error state.
2443 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2444 update_group_times(event
);
2445 event
->state
= PERF_EVENT_STATE_ERROR
;
2451 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2452 struct perf_cpu_context
*cpuctx
)
2454 struct perf_event
*event
;
2457 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2458 /* Ignore events in OFF or ERROR state */
2459 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2462 * Listen to the 'cpu' scheduling filter constraint
2465 if (!event_filter_match(event
))
2468 /* may need to reset tstamp_enabled */
2469 if (is_cgroup_event(event
))
2470 perf_cgroup_mark_enabled(event
, ctx
);
2472 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2473 if (group_sched_in(event
, cpuctx
, ctx
))
2480 ctx_sched_in(struct perf_event_context
*ctx
,
2481 struct perf_cpu_context
*cpuctx
,
2482 enum event_type_t event_type
,
2483 struct task_struct
*task
)
2486 int is_active
= ctx
->is_active
;
2488 ctx
->is_active
|= event_type
;
2489 if (likely(!ctx
->nr_events
))
2493 ctx
->timestamp
= now
;
2494 perf_cgroup_set_timestamp(task
, ctx
);
2496 * First go through the list and put on any pinned groups
2497 * in order to give them the best chance of going on.
2499 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2500 ctx_pinned_sched_in(ctx
, cpuctx
);
2502 /* Then walk through the lower prio flexible groups */
2503 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2504 ctx_flexible_sched_in(ctx
, cpuctx
);
2507 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2508 enum event_type_t event_type
,
2509 struct task_struct
*task
)
2511 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2513 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2516 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2517 struct task_struct
*task
)
2519 struct perf_cpu_context
*cpuctx
;
2521 cpuctx
= __get_cpu_context(ctx
);
2522 if (cpuctx
->task_ctx
== ctx
)
2525 perf_ctx_lock(cpuctx
, ctx
);
2526 perf_pmu_disable(ctx
->pmu
);
2528 * We want to keep the following priority order:
2529 * cpu pinned (that don't need to move), task pinned,
2530 * cpu flexible, task flexible.
2532 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2535 cpuctx
->task_ctx
= ctx
;
2537 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2539 perf_pmu_enable(ctx
->pmu
);
2540 perf_ctx_unlock(cpuctx
, ctx
);
2543 * Since these rotations are per-cpu, we need to ensure the
2544 * cpu-context we got scheduled on is actually rotating.
2546 perf_pmu_rotate_start(ctx
->pmu
);
2550 * When sampling the branck stack in system-wide, it may be necessary
2551 * to flush the stack on context switch. This happens when the branch
2552 * stack does not tag its entries with the pid of the current task.
2553 * Otherwise it becomes impossible to associate a branch entry with a
2554 * task. This ambiguity is more likely to appear when the branch stack
2555 * supports priv level filtering and the user sets it to monitor only
2556 * at the user level (which could be a useful measurement in system-wide
2557 * mode). In that case, the risk is high of having a branch stack with
2558 * branch from multiple tasks. Flushing may mean dropping the existing
2559 * entries or stashing them somewhere in the PMU specific code layer.
2561 * This function provides the context switch callback to the lower code
2562 * layer. It is invoked ONLY when there is at least one system-wide context
2563 * with at least one active event using taken branch sampling.
2565 static void perf_branch_stack_sched_in(struct task_struct
*prev
,
2566 struct task_struct
*task
)
2568 struct perf_cpu_context
*cpuctx
;
2570 unsigned long flags
;
2572 /* no need to flush branch stack if not changing task */
2576 local_irq_save(flags
);
2580 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2581 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2584 * check if the context has at least one
2585 * event using PERF_SAMPLE_BRANCH_STACK
2587 if (cpuctx
->ctx
.nr_branch_stack
> 0
2588 && pmu
->flush_branch_stack
) {
2590 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2592 perf_pmu_disable(pmu
);
2594 pmu
->flush_branch_stack();
2596 perf_pmu_enable(pmu
);
2598 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2604 local_irq_restore(flags
);
2608 * Called from scheduler to add the events of the current task
2609 * with interrupts disabled.
2611 * We restore the event value and then enable it.
2613 * This does not protect us against NMI, but enable()
2614 * sets the enabled bit in the control field of event _before_
2615 * accessing the event control register. If a NMI hits, then it will
2616 * keep the event running.
2618 void __perf_event_task_sched_in(struct task_struct
*prev
,
2619 struct task_struct
*task
)
2621 struct perf_event_context
*ctx
;
2624 for_each_task_context_nr(ctxn
) {
2625 ctx
= task
->perf_event_ctxp
[ctxn
];
2629 perf_event_context_sched_in(ctx
, task
);
2632 * if cgroup events exist on this CPU, then we need
2633 * to check if we have to switch in PMU state.
2634 * cgroup event are system-wide mode only
2636 if (atomic_read(&__get_cpu_var(perf_cgroup_events
)))
2637 perf_cgroup_sched_in(prev
, task
);
2639 /* check for system-wide branch_stack events */
2640 if (atomic_read(&__get_cpu_var(perf_branch_stack_events
)))
2641 perf_branch_stack_sched_in(prev
, task
);
2644 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2646 u64 frequency
= event
->attr
.sample_freq
;
2647 u64 sec
= NSEC_PER_SEC
;
2648 u64 divisor
, dividend
;
2650 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2652 count_fls
= fls64(count
);
2653 nsec_fls
= fls64(nsec
);
2654 frequency_fls
= fls64(frequency
);
2658 * We got @count in @nsec, with a target of sample_freq HZ
2659 * the target period becomes:
2662 * period = -------------------
2663 * @nsec * sample_freq
2668 * Reduce accuracy by one bit such that @a and @b converge
2669 * to a similar magnitude.
2671 #define REDUCE_FLS(a, b) \
2673 if (a##_fls > b##_fls) { \
2683 * Reduce accuracy until either term fits in a u64, then proceed with
2684 * the other, so that finally we can do a u64/u64 division.
2686 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2687 REDUCE_FLS(nsec
, frequency
);
2688 REDUCE_FLS(sec
, count
);
2691 if (count_fls
+ sec_fls
> 64) {
2692 divisor
= nsec
* frequency
;
2694 while (count_fls
+ sec_fls
> 64) {
2695 REDUCE_FLS(count
, sec
);
2699 dividend
= count
* sec
;
2701 dividend
= count
* sec
;
2703 while (nsec_fls
+ frequency_fls
> 64) {
2704 REDUCE_FLS(nsec
, frequency
);
2708 divisor
= nsec
* frequency
;
2714 return div64_u64(dividend
, divisor
);
2717 static DEFINE_PER_CPU(int, perf_throttled_count
);
2718 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2720 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2722 struct hw_perf_event
*hwc
= &event
->hw
;
2723 s64 period
, sample_period
;
2726 period
= perf_calculate_period(event
, nsec
, count
);
2728 delta
= (s64
)(period
- hwc
->sample_period
);
2729 delta
= (delta
+ 7) / 8; /* low pass filter */
2731 sample_period
= hwc
->sample_period
+ delta
;
2736 hwc
->sample_period
= sample_period
;
2738 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2740 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2742 local64_set(&hwc
->period_left
, 0);
2745 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2750 * combine freq adjustment with unthrottling to avoid two passes over the
2751 * events. At the same time, make sure, having freq events does not change
2752 * the rate of unthrottling as that would introduce bias.
2754 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2757 struct perf_event
*event
;
2758 struct hw_perf_event
*hwc
;
2759 u64 now
, period
= TICK_NSEC
;
2763 * only need to iterate over all events iff:
2764 * - context have events in frequency mode (needs freq adjust)
2765 * - there are events to unthrottle on this cpu
2767 if (!(ctx
->nr_freq
|| needs_unthr
))
2770 raw_spin_lock(&ctx
->lock
);
2771 perf_pmu_disable(ctx
->pmu
);
2773 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
2774 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
2777 if (!event_filter_match(event
))
2780 perf_pmu_disable(event
->pmu
);
2784 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
2785 hwc
->interrupts
= 0;
2786 perf_log_throttle(event
, 1);
2787 event
->pmu
->start(event
, 0);
2790 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
2794 * stop the event and update event->count
2796 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2798 now
= local64_read(&event
->count
);
2799 delta
= now
- hwc
->freq_count_stamp
;
2800 hwc
->freq_count_stamp
= now
;
2804 * reload only if value has changed
2805 * we have stopped the event so tell that
2806 * to perf_adjust_period() to avoid stopping it
2810 perf_adjust_period(event
, period
, delta
, false);
2812 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
2814 perf_pmu_enable(event
->pmu
);
2817 perf_pmu_enable(ctx
->pmu
);
2818 raw_spin_unlock(&ctx
->lock
);
2822 * Round-robin a context's events:
2824 static void rotate_ctx(struct perf_event_context
*ctx
)
2827 * Rotate the first entry last of non-pinned groups. Rotation might be
2828 * disabled by the inheritance code.
2830 if (!ctx
->rotate_disable
)
2831 list_rotate_left(&ctx
->flexible_groups
);
2835 * perf_pmu_rotate_start() and perf_rotate_context() are fully serialized
2836 * because they're strictly cpu affine and rotate_start is called with IRQs
2837 * disabled, while rotate_context is called from IRQ context.
2839 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
2841 struct perf_event_context
*ctx
= NULL
;
2842 int rotate
= 0, remove
= 1;
2844 if (cpuctx
->ctx
.nr_events
) {
2846 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
2850 ctx
= cpuctx
->task_ctx
;
2851 if (ctx
&& ctx
->nr_events
) {
2853 if (ctx
->nr_events
!= ctx
->nr_active
)
2860 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2861 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2863 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2865 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
2867 rotate_ctx(&cpuctx
->ctx
);
2871 perf_event_sched_in(cpuctx
, ctx
, current
);
2873 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2874 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2877 list_del_init(&cpuctx
->rotation_list
);
2882 #ifdef CONFIG_NO_HZ_FULL
2883 bool perf_event_can_stop_tick(void)
2885 if (atomic_read(&nr_freq_events
) ||
2886 __this_cpu_read(perf_throttled_count
))
2893 void perf_event_task_tick(void)
2895 struct list_head
*head
= &__get_cpu_var(rotation_list
);
2896 struct perf_cpu_context
*cpuctx
, *tmp
;
2897 struct perf_event_context
*ctx
;
2900 WARN_ON(!irqs_disabled());
2902 __this_cpu_inc(perf_throttled_seq
);
2903 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
2905 list_for_each_entry_safe(cpuctx
, tmp
, head
, rotation_list
) {
2907 perf_adjust_freq_unthr_context(ctx
, throttled
);
2909 ctx
= cpuctx
->task_ctx
;
2911 perf_adjust_freq_unthr_context(ctx
, throttled
);
2915 static int event_enable_on_exec(struct perf_event
*event
,
2916 struct perf_event_context
*ctx
)
2918 if (!event
->attr
.enable_on_exec
)
2921 event
->attr
.enable_on_exec
= 0;
2922 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2925 __perf_event_mark_enabled(event
);
2931 * Enable all of a task's events that have been marked enable-on-exec.
2932 * This expects task == current.
2934 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
2936 struct perf_event
*event
;
2937 unsigned long flags
;
2941 local_irq_save(flags
);
2942 if (!ctx
|| !ctx
->nr_events
)
2946 * We must ctxsw out cgroup events to avoid conflict
2947 * when invoking perf_task_event_sched_in() later on
2948 * in this function. Otherwise we end up trying to
2949 * ctxswin cgroup events which are already scheduled
2952 perf_cgroup_sched_out(current
, NULL
);
2954 raw_spin_lock(&ctx
->lock
);
2955 task_ctx_sched_out(ctx
);
2957 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
2958 ret
= event_enable_on_exec(event
, ctx
);
2964 * Unclone this context if we enabled any event.
2969 raw_spin_unlock(&ctx
->lock
);
2972 * Also calls ctxswin for cgroup events, if any:
2974 perf_event_context_sched_in(ctx
, ctx
->task
);
2976 local_irq_restore(flags
);
2979 void perf_event_exec(void)
2981 struct perf_event_context
*ctx
;
2985 for_each_task_context_nr(ctxn
) {
2986 ctx
= current
->perf_event_ctxp
[ctxn
];
2990 perf_event_enable_on_exec(ctx
);
2996 * Cross CPU call to read the hardware event
2998 static void __perf_event_read(void *info
)
3000 struct perf_event
*event
= info
;
3001 struct perf_event_context
*ctx
= event
->ctx
;
3002 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3005 * If this is a task context, we need to check whether it is
3006 * the current task context of this cpu. If not it has been
3007 * scheduled out before the smp call arrived. In that case
3008 * event->count would have been updated to a recent sample
3009 * when the event was scheduled out.
3011 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3014 raw_spin_lock(&ctx
->lock
);
3015 if (ctx
->is_active
) {
3016 update_context_time(ctx
);
3017 update_cgrp_time_from_event(event
);
3019 update_event_times(event
);
3020 if (event
->state
== PERF_EVENT_STATE_ACTIVE
)
3021 event
->pmu
->read(event
);
3022 raw_spin_unlock(&ctx
->lock
);
3025 static inline u64
perf_event_count(struct perf_event
*event
)
3027 return local64_read(&event
->count
) + atomic64_read(&event
->child_count
);
3030 static u64
perf_event_read(struct perf_event
*event
)
3033 * If event is enabled and currently active on a CPU, update the
3034 * value in the event structure:
3036 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3037 smp_call_function_single(event
->oncpu
,
3038 __perf_event_read
, event
, 1);
3039 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3040 struct perf_event_context
*ctx
= event
->ctx
;
3041 unsigned long flags
;
3043 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3045 * may read while context is not active
3046 * (e.g., thread is blocked), in that case
3047 * we cannot update context time
3049 if (ctx
->is_active
) {
3050 update_context_time(ctx
);
3051 update_cgrp_time_from_event(event
);
3053 update_event_times(event
);
3054 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3057 return perf_event_count(event
);
3061 * Initialize the perf_event context in a task_struct:
3063 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3065 raw_spin_lock_init(&ctx
->lock
);
3066 mutex_init(&ctx
->mutex
);
3067 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3068 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3069 INIT_LIST_HEAD(&ctx
->event_list
);
3070 atomic_set(&ctx
->refcount
, 1);
3073 static struct perf_event_context
*
3074 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3076 struct perf_event_context
*ctx
;
3078 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3082 __perf_event_init_context(ctx
);
3085 get_task_struct(task
);
3092 static struct task_struct
*
3093 find_lively_task_by_vpid(pid_t vpid
)
3095 struct task_struct
*task
;
3102 task
= find_task_by_vpid(vpid
);
3104 get_task_struct(task
);
3108 return ERR_PTR(-ESRCH
);
3110 /* Reuse ptrace permission checks for now. */
3112 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3117 put_task_struct(task
);
3118 return ERR_PTR(err
);
3123 * Returns a matching context with refcount and pincount.
3125 static struct perf_event_context
*
3126 find_get_context(struct pmu
*pmu
, struct task_struct
*task
, int cpu
)
3128 struct perf_event_context
*ctx
;
3129 struct perf_cpu_context
*cpuctx
;
3130 unsigned long flags
;
3134 /* Must be root to operate on a CPU event: */
3135 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3136 return ERR_PTR(-EACCES
);
3139 * We could be clever and allow to attach a event to an
3140 * offline CPU and activate it when the CPU comes up, but
3143 if (!cpu_online(cpu
))
3144 return ERR_PTR(-ENODEV
);
3146 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3155 ctxn
= pmu
->task_ctx_nr
;
3160 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3164 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3166 ctx
= alloc_perf_context(pmu
, task
);
3172 mutex_lock(&task
->perf_event_mutex
);
3174 * If it has already passed perf_event_exit_task().
3175 * we must see PF_EXITING, it takes this mutex too.
3177 if (task
->flags
& PF_EXITING
)
3179 else if (task
->perf_event_ctxp
[ctxn
])
3184 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3186 mutex_unlock(&task
->perf_event_mutex
);
3188 if (unlikely(err
)) {
3200 return ERR_PTR(err
);
3203 static void perf_event_free_filter(struct perf_event
*event
);
3205 static void free_event_rcu(struct rcu_head
*head
)
3207 struct perf_event
*event
;
3209 event
= container_of(head
, struct perf_event
, rcu_head
);
3211 put_pid_ns(event
->ns
);
3212 perf_event_free_filter(event
);
3216 static void ring_buffer_put(struct ring_buffer
*rb
);
3217 static void ring_buffer_attach(struct perf_event
*event
,
3218 struct ring_buffer
*rb
);
3220 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3225 if (has_branch_stack(event
)) {
3226 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
3227 atomic_dec(&per_cpu(perf_branch_stack_events
, cpu
));
3229 if (is_cgroup_event(event
))
3230 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3233 static void unaccount_event(struct perf_event
*event
)
3238 if (event
->attach_state
& PERF_ATTACH_TASK
)
3239 static_key_slow_dec_deferred(&perf_sched_events
);
3240 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3241 atomic_dec(&nr_mmap_events
);
3242 if (event
->attr
.comm
)
3243 atomic_dec(&nr_comm_events
);
3244 if (event
->attr
.task
)
3245 atomic_dec(&nr_task_events
);
3246 if (event
->attr
.freq
)
3247 atomic_dec(&nr_freq_events
);
3248 if (is_cgroup_event(event
))
3249 static_key_slow_dec_deferred(&perf_sched_events
);
3250 if (has_branch_stack(event
))
3251 static_key_slow_dec_deferred(&perf_sched_events
);
3253 unaccount_event_cpu(event
, event
->cpu
);
3256 static void __free_event(struct perf_event
*event
)
3258 if (!event
->parent
) {
3259 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3260 put_callchain_buffers();
3264 event
->destroy(event
);
3267 put_ctx(event
->ctx
);
3270 module_put(event
->pmu
->module
);
3272 call_rcu(&event
->rcu_head
, free_event_rcu
);
3275 static void _free_event(struct perf_event
*event
)
3277 irq_work_sync(&event
->pending
);
3279 unaccount_event(event
);
3283 * Can happen when we close an event with re-directed output.
3285 * Since we have a 0 refcount, perf_mmap_close() will skip
3286 * over us; possibly making our ring_buffer_put() the last.
3288 mutex_lock(&event
->mmap_mutex
);
3289 ring_buffer_attach(event
, NULL
);
3290 mutex_unlock(&event
->mmap_mutex
);
3293 if (is_cgroup_event(event
))
3294 perf_detach_cgroup(event
);
3296 __free_event(event
);
3300 * Used to free events which have a known refcount of 1, such as in error paths
3301 * where the event isn't exposed yet and inherited events.
3303 static void free_event(struct perf_event
*event
)
3305 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3306 "unexpected event refcount: %ld; ptr=%p\n",
3307 atomic_long_read(&event
->refcount
), event
)) {
3308 /* leak to avoid use-after-free */
3316 * Called when the last reference to the file is gone.
3318 static void put_event(struct perf_event
*event
)
3320 struct perf_event_context
*ctx
= event
->ctx
;
3321 struct task_struct
*owner
;
3323 if (!atomic_long_dec_and_test(&event
->refcount
))
3327 owner
= ACCESS_ONCE(event
->owner
);
3329 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3330 * !owner it means the list deletion is complete and we can indeed
3331 * free this event, otherwise we need to serialize on
3332 * owner->perf_event_mutex.
3334 smp_read_barrier_depends();
3337 * Since delayed_put_task_struct() also drops the last
3338 * task reference we can safely take a new reference
3339 * while holding the rcu_read_lock().
3341 get_task_struct(owner
);
3346 mutex_lock(&owner
->perf_event_mutex
);
3348 * We have to re-check the event->owner field, if it is cleared
3349 * we raced with perf_event_exit_task(), acquiring the mutex
3350 * ensured they're done, and we can proceed with freeing the
3354 list_del_init(&event
->owner_entry
);
3355 mutex_unlock(&owner
->perf_event_mutex
);
3356 put_task_struct(owner
);
3359 WARN_ON_ONCE(ctx
->parent_ctx
);
3361 * There are two ways this annotation is useful:
3363 * 1) there is a lock recursion from perf_event_exit_task
3364 * see the comment there.
3366 * 2) there is a lock-inversion with mmap_sem through
3367 * perf_event_read_group(), which takes faults while
3368 * holding ctx->mutex, however this is called after
3369 * the last filedesc died, so there is no possibility
3370 * to trigger the AB-BA case.
3372 mutex_lock_nested(&ctx
->mutex
, SINGLE_DEPTH_NESTING
);
3373 perf_remove_from_context(event
, true);
3374 mutex_unlock(&ctx
->mutex
);
3379 int perf_event_release_kernel(struct perf_event
*event
)
3384 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3386 static int perf_release(struct inode
*inode
, struct file
*file
)
3388 put_event(file
->private_data
);
3392 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3394 struct perf_event
*child
;
3400 mutex_lock(&event
->child_mutex
);
3401 total
+= perf_event_read(event
);
3402 *enabled
+= event
->total_time_enabled
+
3403 atomic64_read(&event
->child_total_time_enabled
);
3404 *running
+= event
->total_time_running
+
3405 atomic64_read(&event
->child_total_time_running
);
3407 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3408 total
+= perf_event_read(child
);
3409 *enabled
+= child
->total_time_enabled
;
3410 *running
+= child
->total_time_running
;
3412 mutex_unlock(&event
->child_mutex
);
3416 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3418 static int perf_event_read_group(struct perf_event
*event
,
3419 u64 read_format
, char __user
*buf
)
3421 struct perf_event
*leader
= event
->group_leader
, *sub
;
3422 int n
= 0, size
= 0, ret
= -EFAULT
;
3423 struct perf_event_context
*ctx
= leader
->ctx
;
3425 u64 count
, enabled
, running
;
3427 mutex_lock(&ctx
->mutex
);
3428 count
= perf_event_read_value(leader
, &enabled
, &running
);
3430 values
[n
++] = 1 + leader
->nr_siblings
;
3431 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3432 values
[n
++] = enabled
;
3433 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3434 values
[n
++] = running
;
3435 values
[n
++] = count
;
3436 if (read_format
& PERF_FORMAT_ID
)
3437 values
[n
++] = primary_event_id(leader
);
3439 size
= n
* sizeof(u64
);
3441 if (copy_to_user(buf
, values
, size
))
3446 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3449 values
[n
++] = perf_event_read_value(sub
, &enabled
, &running
);
3450 if (read_format
& PERF_FORMAT_ID
)
3451 values
[n
++] = primary_event_id(sub
);
3453 size
= n
* sizeof(u64
);
3455 if (copy_to_user(buf
+ ret
, values
, size
)) {
3463 mutex_unlock(&ctx
->mutex
);
3468 static int perf_event_read_one(struct perf_event
*event
,
3469 u64 read_format
, char __user
*buf
)
3471 u64 enabled
, running
;
3475 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
3476 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
3477 values
[n
++] = enabled
;
3478 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
3479 values
[n
++] = running
;
3480 if (read_format
& PERF_FORMAT_ID
)
3481 values
[n
++] = primary_event_id(event
);
3483 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
3486 return n
* sizeof(u64
);
3490 * Read the performance event - simple non blocking version for now
3493 perf_read_hw(struct perf_event
*event
, char __user
*buf
, size_t count
)
3495 u64 read_format
= event
->attr
.read_format
;
3499 * Return end-of-file for a read on a event that is in
3500 * error state (i.e. because it was pinned but it couldn't be
3501 * scheduled on to the CPU at some point).
3503 if (event
->state
== PERF_EVENT_STATE_ERROR
)
3506 if (count
< event
->read_size
)
3509 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3510 if (read_format
& PERF_FORMAT_GROUP
)
3511 ret
= perf_event_read_group(event
, read_format
, buf
);
3513 ret
= perf_event_read_one(event
, read_format
, buf
);
3519 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
3521 struct perf_event
*event
= file
->private_data
;
3523 return perf_read_hw(event
, buf
, count
);
3526 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
3528 struct perf_event
*event
= file
->private_data
;
3529 struct ring_buffer
*rb
;
3530 unsigned int events
= POLL_HUP
;
3533 * Pin the event->rb by taking event->mmap_mutex; otherwise
3534 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
3536 mutex_lock(&event
->mmap_mutex
);
3539 events
= atomic_xchg(&rb
->poll
, 0);
3540 mutex_unlock(&event
->mmap_mutex
);
3542 poll_wait(file
, &event
->waitq
, wait
);
3547 static void perf_event_reset(struct perf_event
*event
)
3549 (void)perf_event_read(event
);
3550 local64_set(&event
->count
, 0);
3551 perf_event_update_userpage(event
);
3555 * Holding the top-level event's child_mutex means that any
3556 * descendant process that has inherited this event will block
3557 * in sync_child_event if it goes to exit, thus satisfying the
3558 * task existence requirements of perf_event_enable/disable.
3560 static void perf_event_for_each_child(struct perf_event
*event
,
3561 void (*func
)(struct perf_event
*))
3563 struct perf_event
*child
;
3565 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
3566 mutex_lock(&event
->child_mutex
);
3568 list_for_each_entry(child
, &event
->child_list
, child_list
)
3570 mutex_unlock(&event
->child_mutex
);
3573 static void perf_event_for_each(struct perf_event
*event
,
3574 void (*func
)(struct perf_event
*))
3576 struct perf_event_context
*ctx
= event
->ctx
;
3577 struct perf_event
*sibling
;
3579 WARN_ON_ONCE(ctx
->parent_ctx
);
3580 mutex_lock(&ctx
->mutex
);
3581 event
= event
->group_leader
;
3583 perf_event_for_each_child(event
, func
);
3584 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
3585 perf_event_for_each_child(sibling
, func
);
3586 mutex_unlock(&ctx
->mutex
);
3589 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
3591 struct perf_event_context
*ctx
= event
->ctx
;
3592 int ret
= 0, active
;
3595 if (!is_sampling_event(event
))
3598 if (copy_from_user(&value
, arg
, sizeof(value
)))
3604 raw_spin_lock_irq(&ctx
->lock
);
3605 if (event
->attr
.freq
) {
3606 if (value
> sysctl_perf_event_sample_rate
) {
3611 event
->attr
.sample_freq
= value
;
3613 event
->attr
.sample_period
= value
;
3614 event
->hw
.sample_period
= value
;
3617 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
3619 perf_pmu_disable(ctx
->pmu
);
3620 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3623 local64_set(&event
->hw
.period_left
, 0);
3626 event
->pmu
->start(event
, PERF_EF_RELOAD
);
3627 perf_pmu_enable(ctx
->pmu
);
3631 raw_spin_unlock_irq(&ctx
->lock
);
3636 static const struct file_operations perf_fops
;
3638 static inline int perf_fget_light(int fd
, struct fd
*p
)
3640 struct fd f
= fdget(fd
);
3644 if (f
.file
->f_op
!= &perf_fops
) {
3652 static int perf_event_set_output(struct perf_event
*event
,
3653 struct perf_event
*output_event
);
3654 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
3656 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
3658 struct perf_event
*event
= file
->private_data
;
3659 void (*func
)(struct perf_event
*);
3663 case PERF_EVENT_IOC_ENABLE
:
3664 func
= perf_event_enable
;
3666 case PERF_EVENT_IOC_DISABLE
:
3667 func
= perf_event_disable
;
3669 case PERF_EVENT_IOC_RESET
:
3670 func
= perf_event_reset
;
3673 case PERF_EVENT_IOC_REFRESH
:
3674 return perf_event_refresh(event
, arg
);
3676 case PERF_EVENT_IOC_PERIOD
:
3677 return perf_event_period(event
, (u64 __user
*)arg
);
3679 case PERF_EVENT_IOC_ID
:
3681 u64 id
= primary_event_id(event
);
3683 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
3688 case PERF_EVENT_IOC_SET_OUTPUT
:
3692 struct perf_event
*output_event
;
3694 ret
= perf_fget_light(arg
, &output
);
3697 output_event
= output
.file
->private_data
;
3698 ret
= perf_event_set_output(event
, output_event
);
3701 ret
= perf_event_set_output(event
, NULL
);
3706 case PERF_EVENT_IOC_SET_FILTER
:
3707 return perf_event_set_filter(event
, (void __user
*)arg
);
3713 if (flags
& PERF_IOC_FLAG_GROUP
)
3714 perf_event_for_each(event
, func
);
3716 perf_event_for_each_child(event
, func
);
3721 #ifdef CONFIG_COMPAT
3722 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
3725 switch (_IOC_NR(cmd
)) {
3726 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
3727 case _IOC_NR(PERF_EVENT_IOC_ID
):
3728 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
3729 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
3730 cmd
&= ~IOCSIZE_MASK
;
3731 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
3735 return perf_ioctl(file
, cmd
, arg
);
3738 # define perf_compat_ioctl NULL
3741 int perf_event_task_enable(void)
3743 struct perf_event
*event
;
3745 mutex_lock(¤t
->perf_event_mutex
);
3746 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3747 perf_event_for_each_child(event
, perf_event_enable
);
3748 mutex_unlock(¤t
->perf_event_mutex
);
3753 int perf_event_task_disable(void)
3755 struct perf_event
*event
;
3757 mutex_lock(¤t
->perf_event_mutex
);
3758 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
)
3759 perf_event_for_each_child(event
, perf_event_disable
);
3760 mutex_unlock(¤t
->perf_event_mutex
);
3765 static int perf_event_index(struct perf_event
*event
)
3767 if (event
->hw
.state
& PERF_HES_STOPPED
)
3770 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3773 return event
->pmu
->event_idx(event
);
3776 static void calc_timer_values(struct perf_event
*event
,
3783 *now
= perf_clock();
3784 ctx_time
= event
->shadow_ctx_time
+ *now
;
3785 *enabled
= ctx_time
- event
->tstamp_enabled
;
3786 *running
= ctx_time
- event
->tstamp_running
;
3789 static void perf_event_init_userpage(struct perf_event
*event
)
3791 struct perf_event_mmap_page
*userpg
;
3792 struct ring_buffer
*rb
;
3795 rb
= rcu_dereference(event
->rb
);
3799 userpg
= rb
->user_page
;
3801 /* Allow new userspace to detect that bit 0 is deprecated */
3802 userpg
->cap_bit0_is_deprecated
= 1;
3803 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
3809 void __weak
arch_perf_update_userpage(struct perf_event_mmap_page
*userpg
, u64 now
)
3814 * Callers need to ensure there can be no nesting of this function, otherwise
3815 * the seqlock logic goes bad. We can not serialize this because the arch
3816 * code calls this from NMI context.
3818 void perf_event_update_userpage(struct perf_event
*event
)
3820 struct perf_event_mmap_page
*userpg
;
3821 struct ring_buffer
*rb
;
3822 u64 enabled
, running
, now
;
3825 rb
= rcu_dereference(event
->rb
);
3830 * compute total_time_enabled, total_time_running
3831 * based on snapshot values taken when the event
3832 * was last scheduled in.
3834 * we cannot simply called update_context_time()
3835 * because of locking issue as we can be called in
3838 calc_timer_values(event
, &now
, &enabled
, &running
);
3840 userpg
= rb
->user_page
;
3842 * Disable preemption so as to not let the corresponding user-space
3843 * spin too long if we get preempted.
3848 userpg
->index
= perf_event_index(event
);
3849 userpg
->offset
= perf_event_count(event
);
3851 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
3853 userpg
->time_enabled
= enabled
+
3854 atomic64_read(&event
->child_total_time_enabled
);
3856 userpg
->time_running
= running
+
3857 atomic64_read(&event
->child_total_time_running
);
3859 arch_perf_update_userpage(userpg
, now
);
3868 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
3870 struct perf_event
*event
= vma
->vm_file
->private_data
;
3871 struct ring_buffer
*rb
;
3872 int ret
= VM_FAULT_SIGBUS
;
3874 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
3875 if (vmf
->pgoff
== 0)
3881 rb
= rcu_dereference(event
->rb
);
3885 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
3888 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
3892 get_page(vmf
->page
);
3893 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
3894 vmf
->page
->index
= vmf
->pgoff
;
3903 static void ring_buffer_attach(struct perf_event
*event
,
3904 struct ring_buffer
*rb
)
3906 struct ring_buffer
*old_rb
= NULL
;
3907 unsigned long flags
;
3911 * Should be impossible, we set this when removing
3912 * event->rb_entry and wait/clear when adding event->rb_entry.
3914 WARN_ON_ONCE(event
->rcu_pending
);
3917 event
->rcu_batches
= get_state_synchronize_rcu();
3918 event
->rcu_pending
= 1;
3920 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
3921 list_del_rcu(&event
->rb_entry
);
3922 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
3925 if (event
->rcu_pending
&& rb
) {
3926 cond_synchronize_rcu(event
->rcu_batches
);
3927 event
->rcu_pending
= 0;
3931 spin_lock_irqsave(&rb
->event_lock
, flags
);
3932 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
3933 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
3936 rcu_assign_pointer(event
->rb
, rb
);
3939 ring_buffer_put(old_rb
);
3941 * Since we detached before setting the new rb, so that we
3942 * could attach the new rb, we could have missed a wakeup.
3945 wake_up_all(&event
->waitq
);
3949 static void ring_buffer_wakeup(struct perf_event
*event
)
3951 struct ring_buffer
*rb
;
3954 rb
= rcu_dereference(event
->rb
);
3956 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
3957 wake_up_all(&event
->waitq
);
3962 static void rb_free_rcu(struct rcu_head
*rcu_head
)
3964 struct ring_buffer
*rb
;
3966 rb
= container_of(rcu_head
, struct ring_buffer
, rcu_head
);
3970 static struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
3972 struct ring_buffer
*rb
;
3975 rb
= rcu_dereference(event
->rb
);
3977 if (!atomic_inc_not_zero(&rb
->refcount
))
3985 static void ring_buffer_put(struct ring_buffer
*rb
)
3987 if (!atomic_dec_and_test(&rb
->refcount
))
3990 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
3992 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
3995 static void perf_mmap_open(struct vm_area_struct
*vma
)
3997 struct perf_event
*event
= vma
->vm_file
->private_data
;
3999 atomic_inc(&event
->mmap_count
);
4000 atomic_inc(&event
->rb
->mmap_count
);
4004 * A buffer can be mmap()ed multiple times; either directly through the same
4005 * event, or through other events by use of perf_event_set_output().
4007 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4008 * the buffer here, where we still have a VM context. This means we need
4009 * to detach all events redirecting to us.
4011 static void perf_mmap_close(struct vm_area_struct
*vma
)
4013 struct perf_event
*event
= vma
->vm_file
->private_data
;
4015 struct ring_buffer
*rb
= ring_buffer_get(event
);
4016 struct user_struct
*mmap_user
= rb
->mmap_user
;
4017 int mmap_locked
= rb
->mmap_locked
;
4018 unsigned long size
= perf_data_size(rb
);
4020 atomic_dec(&rb
->mmap_count
);
4022 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4025 ring_buffer_attach(event
, NULL
);
4026 mutex_unlock(&event
->mmap_mutex
);
4028 /* If there's still other mmap()s of this buffer, we're done. */
4029 if (atomic_read(&rb
->mmap_count
))
4033 * No other mmap()s, detach from all other events that might redirect
4034 * into the now unreachable buffer. Somewhat complicated by the
4035 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4039 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4040 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4042 * This event is en-route to free_event() which will
4043 * detach it and remove it from the list.
4049 mutex_lock(&event
->mmap_mutex
);
4051 * Check we didn't race with perf_event_set_output() which can
4052 * swizzle the rb from under us while we were waiting to
4053 * acquire mmap_mutex.
4055 * If we find a different rb; ignore this event, a next
4056 * iteration will no longer find it on the list. We have to
4057 * still restart the iteration to make sure we're not now
4058 * iterating the wrong list.
4060 if (event
->rb
== rb
)
4061 ring_buffer_attach(event
, NULL
);
4063 mutex_unlock(&event
->mmap_mutex
);
4067 * Restart the iteration; either we're on the wrong list or
4068 * destroyed its integrity by doing a deletion.
4075 * It could be there's still a few 0-ref events on the list; they'll
4076 * get cleaned up by free_event() -- they'll also still have their
4077 * ref on the rb and will free it whenever they are done with it.
4079 * Aside from that, this buffer is 'fully' detached and unmapped,
4080 * undo the VM accounting.
4083 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4084 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4085 free_uid(mmap_user
);
4088 ring_buffer_put(rb
); /* could be last */
4091 static const struct vm_operations_struct perf_mmap_vmops
= {
4092 .open
= perf_mmap_open
,
4093 .close
= perf_mmap_close
,
4094 .fault
= perf_mmap_fault
,
4095 .page_mkwrite
= perf_mmap_fault
,
4098 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4100 struct perf_event
*event
= file
->private_data
;
4101 unsigned long user_locked
, user_lock_limit
;
4102 struct user_struct
*user
= current_user();
4103 unsigned long locked
, lock_limit
;
4104 struct ring_buffer
*rb
;
4105 unsigned long vma_size
;
4106 unsigned long nr_pages
;
4107 long user_extra
, extra
;
4108 int ret
= 0, flags
= 0;
4111 * Don't allow mmap() of inherited per-task counters. This would
4112 * create a performance issue due to all children writing to the
4115 if (event
->cpu
== -1 && event
->attr
.inherit
)
4118 if (!(vma
->vm_flags
& VM_SHARED
))
4121 vma_size
= vma
->vm_end
- vma
->vm_start
;
4122 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4125 * If we have rb pages ensure they're a power-of-two number, so we
4126 * can do bitmasks instead of modulo.
4128 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4131 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4134 if (vma
->vm_pgoff
!= 0)
4137 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4139 mutex_lock(&event
->mmap_mutex
);
4141 if (event
->rb
->nr_pages
!= nr_pages
) {
4146 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4148 * Raced against perf_mmap_close() through
4149 * perf_event_set_output(). Try again, hope for better
4152 mutex_unlock(&event
->mmap_mutex
);
4159 user_extra
= nr_pages
+ 1;
4160 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4163 * Increase the limit linearly with more CPUs:
4165 user_lock_limit
*= num_online_cpus();
4167 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4170 if (user_locked
> user_lock_limit
)
4171 extra
= user_locked
- user_lock_limit
;
4173 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4174 lock_limit
>>= PAGE_SHIFT
;
4175 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4177 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4178 !capable(CAP_IPC_LOCK
)) {
4185 if (vma
->vm_flags
& VM_WRITE
)
4186 flags
|= RING_BUFFER_WRITABLE
;
4188 rb
= rb_alloc(nr_pages
,
4189 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4197 atomic_set(&rb
->mmap_count
, 1);
4198 rb
->mmap_locked
= extra
;
4199 rb
->mmap_user
= get_current_user();
4201 atomic_long_add(user_extra
, &user
->locked_vm
);
4202 vma
->vm_mm
->pinned_vm
+= extra
;
4204 ring_buffer_attach(event
, rb
);
4206 perf_event_init_userpage(event
);
4207 perf_event_update_userpage(event
);
4211 atomic_inc(&event
->mmap_count
);
4212 mutex_unlock(&event
->mmap_mutex
);
4215 * Since pinned accounting is per vm we cannot allow fork() to copy our
4218 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4219 vma
->vm_ops
= &perf_mmap_vmops
;
4224 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4226 struct inode
*inode
= file_inode(filp
);
4227 struct perf_event
*event
= filp
->private_data
;
4230 mutex_lock(&inode
->i_mutex
);
4231 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4232 mutex_unlock(&inode
->i_mutex
);
4240 static const struct file_operations perf_fops
= {
4241 .llseek
= no_llseek
,
4242 .release
= perf_release
,
4245 .unlocked_ioctl
= perf_ioctl
,
4246 .compat_ioctl
= perf_compat_ioctl
,
4248 .fasync
= perf_fasync
,
4254 * If there's data, ensure we set the poll() state and publish everything
4255 * to user-space before waking everybody up.
4258 void perf_event_wakeup(struct perf_event
*event
)
4260 ring_buffer_wakeup(event
);
4262 if (event
->pending_kill
) {
4263 kill_fasync(&event
->fasync
, SIGIO
, event
->pending_kill
);
4264 event
->pending_kill
= 0;
4268 static void perf_pending_event(struct irq_work
*entry
)
4270 struct perf_event
*event
= container_of(entry
,
4271 struct perf_event
, pending
);
4273 if (event
->pending_disable
) {
4274 event
->pending_disable
= 0;
4275 __perf_event_disable(event
);
4278 if (event
->pending_wakeup
) {
4279 event
->pending_wakeup
= 0;
4280 perf_event_wakeup(event
);
4285 * We assume there is only KVM supporting the callbacks.
4286 * Later on, we might change it to a list if there is
4287 * another virtualization implementation supporting the callbacks.
4289 struct perf_guest_info_callbacks
*perf_guest_cbs
;
4291 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4293 perf_guest_cbs
= cbs
;
4296 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
4298 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
4300 perf_guest_cbs
= NULL
;
4303 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
4306 perf_output_sample_regs(struct perf_output_handle
*handle
,
4307 struct pt_regs
*regs
, u64 mask
)
4311 for_each_set_bit(bit
, (const unsigned long *) &mask
,
4312 sizeof(mask
) * BITS_PER_BYTE
) {
4315 val
= perf_reg_value(regs
, bit
);
4316 perf_output_put(handle
, val
);
4320 static void perf_sample_regs_user(struct perf_regs_user
*regs_user
,
4321 struct pt_regs
*regs
)
4323 if (!user_mode(regs
)) {
4325 regs
= task_pt_regs(current
);
4331 regs_user
->regs
= regs
;
4332 regs_user
->abi
= perf_reg_abi(current
);
4337 * Get remaining task size from user stack pointer.
4339 * It'd be better to take stack vma map and limit this more
4340 * precisly, but there's no way to get it safely under interrupt,
4341 * so using TASK_SIZE as limit.
4343 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
4345 unsigned long addr
= perf_user_stack_pointer(regs
);
4347 if (!addr
|| addr
>= TASK_SIZE
)
4350 return TASK_SIZE
- addr
;
4354 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
4355 struct pt_regs
*regs
)
4359 /* No regs, no stack pointer, no dump. */
4364 * Check if we fit in with the requested stack size into the:
4366 * If we don't, we limit the size to the TASK_SIZE.
4368 * - remaining sample size
4369 * If we don't, we customize the stack size to
4370 * fit in to the remaining sample size.
4373 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
4374 stack_size
= min(stack_size
, (u16
) task_size
);
4376 /* Current header size plus static size and dynamic size. */
4377 header_size
+= 2 * sizeof(u64
);
4379 /* Do we fit in with the current stack dump size? */
4380 if ((u16
) (header_size
+ stack_size
) < header_size
) {
4382 * If we overflow the maximum size for the sample,
4383 * we customize the stack dump size to fit in.
4385 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
4386 stack_size
= round_up(stack_size
, sizeof(u64
));
4393 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
4394 struct pt_regs
*regs
)
4396 /* Case of a kernel thread, nothing to dump */
4399 perf_output_put(handle
, size
);
4408 * - the size requested by user or the best one we can fit
4409 * in to the sample max size
4411 * - user stack dump data
4413 * - the actual dumped size
4417 perf_output_put(handle
, dump_size
);
4420 sp
= perf_user_stack_pointer(regs
);
4421 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
4422 dyn_size
= dump_size
- rem
;
4424 perf_output_skip(handle
, rem
);
4427 perf_output_put(handle
, dyn_size
);
4431 static void __perf_event_header__init_id(struct perf_event_header
*header
,
4432 struct perf_sample_data
*data
,
4433 struct perf_event
*event
)
4435 u64 sample_type
= event
->attr
.sample_type
;
4437 data
->type
= sample_type
;
4438 header
->size
+= event
->id_header_size
;
4440 if (sample_type
& PERF_SAMPLE_TID
) {
4441 /* namespace issues */
4442 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
4443 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
4446 if (sample_type
& PERF_SAMPLE_TIME
)
4447 data
->time
= perf_clock();
4449 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
4450 data
->id
= primary_event_id(event
);
4452 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4453 data
->stream_id
= event
->id
;
4455 if (sample_type
& PERF_SAMPLE_CPU
) {
4456 data
->cpu_entry
.cpu
= raw_smp_processor_id();
4457 data
->cpu_entry
.reserved
= 0;
4461 void perf_event_header__init_id(struct perf_event_header
*header
,
4462 struct perf_sample_data
*data
,
4463 struct perf_event
*event
)
4465 if (event
->attr
.sample_id_all
)
4466 __perf_event_header__init_id(header
, data
, event
);
4469 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
4470 struct perf_sample_data
*data
)
4472 u64 sample_type
= data
->type
;
4474 if (sample_type
& PERF_SAMPLE_TID
)
4475 perf_output_put(handle
, data
->tid_entry
);
4477 if (sample_type
& PERF_SAMPLE_TIME
)
4478 perf_output_put(handle
, data
->time
);
4480 if (sample_type
& PERF_SAMPLE_ID
)
4481 perf_output_put(handle
, data
->id
);
4483 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4484 perf_output_put(handle
, data
->stream_id
);
4486 if (sample_type
& PERF_SAMPLE_CPU
)
4487 perf_output_put(handle
, data
->cpu_entry
);
4489 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
4490 perf_output_put(handle
, data
->id
);
4493 void perf_event__output_id_sample(struct perf_event
*event
,
4494 struct perf_output_handle
*handle
,
4495 struct perf_sample_data
*sample
)
4497 if (event
->attr
.sample_id_all
)
4498 __perf_event__output_id_sample(handle
, sample
);
4501 static void perf_output_read_one(struct perf_output_handle
*handle
,
4502 struct perf_event
*event
,
4503 u64 enabled
, u64 running
)
4505 u64 read_format
= event
->attr
.read_format
;
4509 values
[n
++] = perf_event_count(event
);
4510 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
4511 values
[n
++] = enabled
+
4512 atomic64_read(&event
->child_total_time_enabled
);
4514 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
4515 values
[n
++] = running
+
4516 atomic64_read(&event
->child_total_time_running
);
4518 if (read_format
& PERF_FORMAT_ID
)
4519 values
[n
++] = primary_event_id(event
);
4521 __output_copy(handle
, values
, n
* sizeof(u64
));
4525 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
4527 static void perf_output_read_group(struct perf_output_handle
*handle
,
4528 struct perf_event
*event
,
4529 u64 enabled
, u64 running
)
4531 struct perf_event
*leader
= event
->group_leader
, *sub
;
4532 u64 read_format
= event
->attr
.read_format
;
4536 values
[n
++] = 1 + leader
->nr_siblings
;
4538 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4539 values
[n
++] = enabled
;
4541 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4542 values
[n
++] = running
;
4544 if (leader
!= event
)
4545 leader
->pmu
->read(leader
);
4547 values
[n
++] = perf_event_count(leader
);
4548 if (read_format
& PERF_FORMAT_ID
)
4549 values
[n
++] = primary_event_id(leader
);
4551 __output_copy(handle
, values
, n
* sizeof(u64
));
4553 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
4556 if ((sub
!= event
) &&
4557 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
4558 sub
->pmu
->read(sub
);
4560 values
[n
++] = perf_event_count(sub
);
4561 if (read_format
& PERF_FORMAT_ID
)
4562 values
[n
++] = primary_event_id(sub
);
4564 __output_copy(handle
, values
, n
* sizeof(u64
));
4568 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
4569 PERF_FORMAT_TOTAL_TIME_RUNNING)
4571 static void perf_output_read(struct perf_output_handle
*handle
,
4572 struct perf_event
*event
)
4574 u64 enabled
= 0, running
= 0, now
;
4575 u64 read_format
= event
->attr
.read_format
;
4578 * compute total_time_enabled, total_time_running
4579 * based on snapshot values taken when the event
4580 * was last scheduled in.
4582 * we cannot simply called update_context_time()
4583 * because of locking issue as we are called in
4586 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
4587 calc_timer_values(event
, &now
, &enabled
, &running
);
4589 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
4590 perf_output_read_group(handle
, event
, enabled
, running
);
4592 perf_output_read_one(handle
, event
, enabled
, running
);
4595 void perf_output_sample(struct perf_output_handle
*handle
,
4596 struct perf_event_header
*header
,
4597 struct perf_sample_data
*data
,
4598 struct perf_event
*event
)
4600 u64 sample_type
= data
->type
;
4602 perf_output_put(handle
, *header
);
4604 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
4605 perf_output_put(handle
, data
->id
);
4607 if (sample_type
& PERF_SAMPLE_IP
)
4608 perf_output_put(handle
, data
->ip
);
4610 if (sample_type
& PERF_SAMPLE_TID
)
4611 perf_output_put(handle
, data
->tid_entry
);
4613 if (sample_type
& PERF_SAMPLE_TIME
)
4614 perf_output_put(handle
, data
->time
);
4616 if (sample_type
& PERF_SAMPLE_ADDR
)
4617 perf_output_put(handle
, data
->addr
);
4619 if (sample_type
& PERF_SAMPLE_ID
)
4620 perf_output_put(handle
, data
->id
);
4622 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
4623 perf_output_put(handle
, data
->stream_id
);
4625 if (sample_type
& PERF_SAMPLE_CPU
)
4626 perf_output_put(handle
, data
->cpu_entry
);
4628 if (sample_type
& PERF_SAMPLE_PERIOD
)
4629 perf_output_put(handle
, data
->period
);
4631 if (sample_type
& PERF_SAMPLE_READ
)
4632 perf_output_read(handle
, event
);
4634 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4635 if (data
->callchain
) {
4638 if (data
->callchain
)
4639 size
+= data
->callchain
->nr
;
4641 size
*= sizeof(u64
);
4643 __output_copy(handle
, data
->callchain
, size
);
4646 perf_output_put(handle
, nr
);
4650 if (sample_type
& PERF_SAMPLE_RAW
) {
4652 perf_output_put(handle
, data
->raw
->size
);
4653 __output_copy(handle
, data
->raw
->data
,
4660 .size
= sizeof(u32
),
4663 perf_output_put(handle
, raw
);
4667 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4668 if (data
->br_stack
) {
4671 size
= data
->br_stack
->nr
4672 * sizeof(struct perf_branch_entry
);
4674 perf_output_put(handle
, data
->br_stack
->nr
);
4675 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
4678 * we always store at least the value of nr
4681 perf_output_put(handle
, nr
);
4685 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4686 u64 abi
= data
->regs_user
.abi
;
4689 * If there are no regs to dump, notice it through
4690 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
4692 perf_output_put(handle
, abi
);
4695 u64 mask
= event
->attr
.sample_regs_user
;
4696 perf_output_sample_regs(handle
,
4697 data
->regs_user
.regs
,
4702 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
4703 perf_output_sample_ustack(handle
,
4704 data
->stack_user_size
,
4705 data
->regs_user
.regs
);
4708 if (sample_type
& PERF_SAMPLE_WEIGHT
)
4709 perf_output_put(handle
, data
->weight
);
4711 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
4712 perf_output_put(handle
, data
->data_src
.val
);
4714 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
4715 perf_output_put(handle
, data
->txn
);
4717 if (!event
->attr
.watermark
) {
4718 int wakeup_events
= event
->attr
.wakeup_events
;
4720 if (wakeup_events
) {
4721 struct ring_buffer
*rb
= handle
->rb
;
4722 int events
= local_inc_return(&rb
->events
);
4724 if (events
>= wakeup_events
) {
4725 local_sub(wakeup_events
, &rb
->events
);
4726 local_inc(&rb
->wakeup
);
4732 void perf_prepare_sample(struct perf_event_header
*header
,
4733 struct perf_sample_data
*data
,
4734 struct perf_event
*event
,
4735 struct pt_regs
*regs
)
4737 u64 sample_type
= event
->attr
.sample_type
;
4739 header
->type
= PERF_RECORD_SAMPLE
;
4740 header
->size
= sizeof(*header
) + event
->header_size
;
4743 header
->misc
|= perf_misc_flags(regs
);
4745 __perf_event_header__init_id(header
, data
, event
);
4747 if (sample_type
& PERF_SAMPLE_IP
)
4748 data
->ip
= perf_instruction_pointer(regs
);
4750 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
4753 data
->callchain
= perf_callchain(event
, regs
);
4755 if (data
->callchain
)
4756 size
+= data
->callchain
->nr
;
4758 header
->size
+= size
* sizeof(u64
);
4761 if (sample_type
& PERF_SAMPLE_RAW
) {
4762 int size
= sizeof(u32
);
4765 size
+= data
->raw
->size
;
4767 size
+= sizeof(u32
);
4769 WARN_ON_ONCE(size
& (sizeof(u64
)-1));
4770 header
->size
+= size
;
4773 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
4774 int size
= sizeof(u64
); /* nr */
4775 if (data
->br_stack
) {
4776 size
+= data
->br_stack
->nr
4777 * sizeof(struct perf_branch_entry
);
4779 header
->size
+= size
;
4782 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
4783 /* regs dump ABI info */
4784 int size
= sizeof(u64
);
4786 perf_sample_regs_user(&data
->regs_user
, regs
);
4788 if (data
->regs_user
.regs
) {
4789 u64 mask
= event
->attr
.sample_regs_user
;
4790 size
+= hweight64(mask
) * sizeof(u64
);
4793 header
->size
+= size
;
4796 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
4798 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
4799 * processed as the last one or have additional check added
4800 * in case new sample type is added, because we could eat
4801 * up the rest of the sample size.
4803 struct perf_regs_user
*uregs
= &data
->regs_user
;
4804 u16 stack_size
= event
->attr
.sample_stack_user
;
4805 u16 size
= sizeof(u64
);
4808 perf_sample_regs_user(uregs
, regs
);
4810 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
4814 * If there is something to dump, add space for the dump
4815 * itself and for the field that tells the dynamic size,
4816 * which is how many have been actually dumped.
4819 size
+= sizeof(u64
) + stack_size
;
4821 data
->stack_user_size
= stack_size
;
4822 header
->size
+= size
;
4826 static void perf_event_output(struct perf_event
*event
,
4827 struct perf_sample_data
*data
,
4828 struct pt_regs
*regs
)
4830 struct perf_output_handle handle
;
4831 struct perf_event_header header
;
4833 /* protect the callchain buffers */
4836 perf_prepare_sample(&header
, data
, event
, regs
);
4838 if (perf_output_begin(&handle
, event
, header
.size
))
4841 perf_output_sample(&handle
, &header
, data
, event
);
4843 perf_output_end(&handle
);
4853 struct perf_read_event
{
4854 struct perf_event_header header
;
4861 perf_event_read_event(struct perf_event
*event
,
4862 struct task_struct
*task
)
4864 struct perf_output_handle handle
;
4865 struct perf_sample_data sample
;
4866 struct perf_read_event read_event
= {
4868 .type
= PERF_RECORD_READ
,
4870 .size
= sizeof(read_event
) + event
->read_size
,
4872 .pid
= perf_event_pid(event
, task
),
4873 .tid
= perf_event_tid(event
, task
),
4877 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
4878 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
4882 perf_output_put(&handle
, read_event
);
4883 perf_output_read(&handle
, event
);
4884 perf_event__output_id_sample(event
, &handle
, &sample
);
4886 perf_output_end(&handle
);
4889 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
4892 perf_event_aux_ctx(struct perf_event_context
*ctx
,
4893 perf_event_aux_output_cb output
,
4896 struct perf_event
*event
;
4898 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
4899 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
4901 if (!event_filter_match(event
))
4903 output(event
, data
);
4908 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
4909 struct perf_event_context
*task_ctx
)
4911 struct perf_cpu_context
*cpuctx
;
4912 struct perf_event_context
*ctx
;
4917 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
4918 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
4919 if (cpuctx
->unique_pmu
!= pmu
)
4921 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
4924 ctxn
= pmu
->task_ctx_nr
;
4927 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
4929 perf_event_aux_ctx(ctx
, output
, data
);
4931 put_cpu_ptr(pmu
->pmu_cpu_context
);
4936 perf_event_aux_ctx(task_ctx
, output
, data
);
4943 * task tracking -- fork/exit
4945 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
4948 struct perf_task_event
{
4949 struct task_struct
*task
;
4950 struct perf_event_context
*task_ctx
;
4953 struct perf_event_header header
;
4963 static int perf_event_task_match(struct perf_event
*event
)
4965 return event
->attr
.comm
|| event
->attr
.mmap
||
4966 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
4970 static void perf_event_task_output(struct perf_event
*event
,
4973 struct perf_task_event
*task_event
= data
;
4974 struct perf_output_handle handle
;
4975 struct perf_sample_data sample
;
4976 struct task_struct
*task
= task_event
->task
;
4977 int ret
, size
= task_event
->event_id
.header
.size
;
4979 if (!perf_event_task_match(event
))
4982 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
4984 ret
= perf_output_begin(&handle
, event
,
4985 task_event
->event_id
.header
.size
);
4989 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
4990 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
4992 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
4993 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
4995 perf_output_put(&handle
, task_event
->event_id
);
4997 perf_event__output_id_sample(event
, &handle
, &sample
);
4999 perf_output_end(&handle
);
5001 task_event
->event_id
.header
.size
= size
;
5004 static void perf_event_task(struct task_struct
*task
,
5005 struct perf_event_context
*task_ctx
,
5008 struct perf_task_event task_event
;
5010 if (!atomic_read(&nr_comm_events
) &&
5011 !atomic_read(&nr_mmap_events
) &&
5012 !atomic_read(&nr_task_events
))
5015 task_event
= (struct perf_task_event
){
5017 .task_ctx
= task_ctx
,
5020 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5022 .size
= sizeof(task_event
.event_id
),
5028 .time
= perf_clock(),
5032 perf_event_aux(perf_event_task_output
,
5037 void perf_event_fork(struct task_struct
*task
)
5039 perf_event_task(task
, NULL
, 1);
5046 struct perf_comm_event
{
5047 struct task_struct
*task
;
5052 struct perf_event_header header
;
5059 static int perf_event_comm_match(struct perf_event
*event
)
5061 return event
->attr
.comm
;
5064 static void perf_event_comm_output(struct perf_event
*event
,
5067 struct perf_comm_event
*comm_event
= data
;
5068 struct perf_output_handle handle
;
5069 struct perf_sample_data sample
;
5070 int size
= comm_event
->event_id
.header
.size
;
5073 if (!perf_event_comm_match(event
))
5076 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5077 ret
= perf_output_begin(&handle
, event
,
5078 comm_event
->event_id
.header
.size
);
5083 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5084 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5086 perf_output_put(&handle
, comm_event
->event_id
);
5087 __output_copy(&handle
, comm_event
->comm
,
5088 comm_event
->comm_size
);
5090 perf_event__output_id_sample(event
, &handle
, &sample
);
5092 perf_output_end(&handle
);
5094 comm_event
->event_id
.header
.size
= size
;
5097 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5099 char comm
[TASK_COMM_LEN
];
5102 memset(comm
, 0, sizeof(comm
));
5103 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5104 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5106 comm_event
->comm
= comm
;
5107 comm_event
->comm_size
= size
;
5109 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5111 perf_event_aux(perf_event_comm_output
,
5116 void perf_event_comm(struct task_struct
*task
, bool exec
)
5118 struct perf_comm_event comm_event
;
5120 if (!atomic_read(&nr_comm_events
))
5123 comm_event
= (struct perf_comm_event
){
5129 .type
= PERF_RECORD_COMM
,
5130 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5138 perf_event_comm_event(&comm_event
);
5145 struct perf_mmap_event
{
5146 struct vm_area_struct
*vma
;
5148 const char *file_name
;
5156 struct perf_event_header header
;
5166 static int perf_event_mmap_match(struct perf_event
*event
,
5169 struct perf_mmap_event
*mmap_event
= data
;
5170 struct vm_area_struct
*vma
= mmap_event
->vma
;
5171 int executable
= vma
->vm_flags
& VM_EXEC
;
5173 return (!executable
&& event
->attr
.mmap_data
) ||
5174 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5177 static void perf_event_mmap_output(struct perf_event
*event
,
5180 struct perf_mmap_event
*mmap_event
= data
;
5181 struct perf_output_handle handle
;
5182 struct perf_sample_data sample
;
5183 int size
= mmap_event
->event_id
.header
.size
;
5186 if (!perf_event_mmap_match(event
, data
))
5189 if (event
->attr
.mmap2
) {
5190 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5191 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5192 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5193 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5194 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5195 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5196 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5199 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5200 ret
= perf_output_begin(&handle
, event
,
5201 mmap_event
->event_id
.header
.size
);
5205 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5206 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5208 perf_output_put(&handle
, mmap_event
->event_id
);
5210 if (event
->attr
.mmap2
) {
5211 perf_output_put(&handle
, mmap_event
->maj
);
5212 perf_output_put(&handle
, mmap_event
->min
);
5213 perf_output_put(&handle
, mmap_event
->ino
);
5214 perf_output_put(&handle
, mmap_event
->ino_generation
);
5215 perf_output_put(&handle
, mmap_event
->prot
);
5216 perf_output_put(&handle
, mmap_event
->flags
);
5219 __output_copy(&handle
, mmap_event
->file_name
,
5220 mmap_event
->file_size
);
5222 perf_event__output_id_sample(event
, &handle
, &sample
);
5224 perf_output_end(&handle
);
5226 mmap_event
->event_id
.header
.size
= size
;
5229 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5231 struct vm_area_struct
*vma
= mmap_event
->vma
;
5232 struct file
*file
= vma
->vm_file
;
5233 int maj
= 0, min
= 0;
5234 u64 ino
= 0, gen
= 0;
5235 u32 prot
= 0, flags
= 0;
5242 struct inode
*inode
;
5245 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
5251 * d_path() works from the end of the rb backwards, so we
5252 * need to add enough zero bytes after the string to handle
5253 * the 64bit alignment we do later.
5255 name
= d_path(&file
->f_path
, buf
, PATH_MAX
- sizeof(u64
));
5260 inode
= file_inode(vma
->vm_file
);
5261 dev
= inode
->i_sb
->s_dev
;
5263 gen
= inode
->i_generation
;
5267 if (vma
->vm_flags
& VM_READ
)
5269 if (vma
->vm_flags
& VM_WRITE
)
5271 if (vma
->vm_flags
& VM_EXEC
)
5274 if (vma
->vm_flags
& VM_MAYSHARE
)
5277 flags
= MAP_PRIVATE
;
5279 if (vma
->vm_flags
& VM_DENYWRITE
)
5280 flags
|= MAP_DENYWRITE
;
5281 if (vma
->vm_flags
& VM_MAYEXEC
)
5282 flags
|= MAP_EXECUTABLE
;
5283 if (vma
->vm_flags
& VM_LOCKED
)
5284 flags
|= MAP_LOCKED
;
5285 if (vma
->vm_flags
& VM_HUGETLB
)
5286 flags
|= MAP_HUGETLB
;
5290 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
5291 name
= (char *) vma
->vm_ops
->name(vma
);
5296 name
= (char *)arch_vma_name(vma
);
5300 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
5301 vma
->vm_end
>= vma
->vm_mm
->brk
) {
5305 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
5306 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
5316 strlcpy(tmp
, name
, sizeof(tmp
));
5320 * Since our buffer works in 8 byte units we need to align our string
5321 * size to a multiple of 8. However, we must guarantee the tail end is
5322 * zero'd out to avoid leaking random bits to userspace.
5324 size
= strlen(name
)+1;
5325 while (!IS_ALIGNED(size
, sizeof(u64
)))
5326 name
[size
++] = '\0';
5328 mmap_event
->file_name
= name
;
5329 mmap_event
->file_size
= size
;
5330 mmap_event
->maj
= maj
;
5331 mmap_event
->min
= min
;
5332 mmap_event
->ino
= ino
;
5333 mmap_event
->ino_generation
= gen
;
5334 mmap_event
->prot
= prot
;
5335 mmap_event
->flags
= flags
;
5337 if (!(vma
->vm_flags
& VM_EXEC
))
5338 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
5340 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
5342 perf_event_aux(perf_event_mmap_output
,
5349 void perf_event_mmap(struct vm_area_struct
*vma
)
5351 struct perf_mmap_event mmap_event
;
5353 if (!atomic_read(&nr_mmap_events
))
5356 mmap_event
= (struct perf_mmap_event
){
5362 .type
= PERF_RECORD_MMAP
,
5363 .misc
= PERF_RECORD_MISC_USER
,
5368 .start
= vma
->vm_start
,
5369 .len
= vma
->vm_end
- vma
->vm_start
,
5370 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
5372 /* .maj (attr_mmap2 only) */
5373 /* .min (attr_mmap2 only) */
5374 /* .ino (attr_mmap2 only) */
5375 /* .ino_generation (attr_mmap2 only) */
5376 /* .prot (attr_mmap2 only) */
5377 /* .flags (attr_mmap2 only) */
5380 perf_event_mmap_event(&mmap_event
);
5384 * IRQ throttle logging
5387 static void perf_log_throttle(struct perf_event
*event
, int enable
)
5389 struct perf_output_handle handle
;
5390 struct perf_sample_data sample
;
5394 struct perf_event_header header
;
5398 } throttle_event
= {
5400 .type
= PERF_RECORD_THROTTLE
,
5402 .size
= sizeof(throttle_event
),
5404 .time
= perf_clock(),
5405 .id
= primary_event_id(event
),
5406 .stream_id
= event
->id
,
5410 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
5412 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
5414 ret
= perf_output_begin(&handle
, event
,
5415 throttle_event
.header
.size
);
5419 perf_output_put(&handle
, throttle_event
);
5420 perf_event__output_id_sample(event
, &handle
, &sample
);
5421 perf_output_end(&handle
);
5425 * Generic event overflow handling, sampling.
5428 static int __perf_event_overflow(struct perf_event
*event
,
5429 int throttle
, struct perf_sample_data
*data
,
5430 struct pt_regs
*regs
)
5432 int events
= atomic_read(&event
->event_limit
);
5433 struct hw_perf_event
*hwc
= &event
->hw
;
5438 * Non-sampling counters might still use the PMI to fold short
5439 * hardware counters, ignore those.
5441 if (unlikely(!is_sampling_event(event
)))
5444 seq
= __this_cpu_read(perf_throttled_seq
);
5445 if (seq
!= hwc
->interrupts_seq
) {
5446 hwc
->interrupts_seq
= seq
;
5447 hwc
->interrupts
= 1;
5450 if (unlikely(throttle
5451 && hwc
->interrupts
>= max_samples_per_tick
)) {
5452 __this_cpu_inc(perf_throttled_count
);
5453 hwc
->interrupts
= MAX_INTERRUPTS
;
5454 perf_log_throttle(event
, 0);
5455 tick_nohz_full_kick();
5460 if (event
->attr
.freq
) {
5461 u64 now
= perf_clock();
5462 s64 delta
= now
- hwc
->freq_time_stamp
;
5464 hwc
->freq_time_stamp
= now
;
5466 if (delta
> 0 && delta
< 2*TICK_NSEC
)
5467 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
5471 * XXX event_limit might not quite work as expected on inherited
5475 event
->pending_kill
= POLL_IN
;
5476 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
5478 event
->pending_kill
= POLL_HUP
;
5479 event
->pending_disable
= 1;
5480 irq_work_queue(&event
->pending
);
5483 if (event
->overflow_handler
)
5484 event
->overflow_handler(event
, data
, regs
);
5486 perf_event_output(event
, data
, regs
);
5488 if (event
->fasync
&& event
->pending_kill
) {
5489 event
->pending_wakeup
= 1;
5490 irq_work_queue(&event
->pending
);
5496 int perf_event_overflow(struct perf_event
*event
,
5497 struct perf_sample_data
*data
,
5498 struct pt_regs
*regs
)
5500 return __perf_event_overflow(event
, 1, data
, regs
);
5504 * Generic software event infrastructure
5507 struct swevent_htable
{
5508 struct swevent_hlist
*swevent_hlist
;
5509 struct mutex hlist_mutex
;
5512 /* Recursion avoidance in each contexts */
5513 int recursion
[PERF_NR_CONTEXTS
];
5515 /* Keeps track of cpu being initialized/exited */
5519 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
5522 * We directly increment event->count and keep a second value in
5523 * event->hw.period_left to count intervals. This period event
5524 * is kept in the range [-sample_period, 0] so that we can use the
5528 u64
perf_swevent_set_period(struct perf_event
*event
)
5530 struct hw_perf_event
*hwc
= &event
->hw
;
5531 u64 period
= hwc
->last_period
;
5535 hwc
->last_period
= hwc
->sample_period
;
5538 old
= val
= local64_read(&hwc
->period_left
);
5542 nr
= div64_u64(period
+ val
, period
);
5543 offset
= nr
* period
;
5545 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
5551 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
5552 struct perf_sample_data
*data
,
5553 struct pt_regs
*regs
)
5555 struct hw_perf_event
*hwc
= &event
->hw
;
5559 overflow
= perf_swevent_set_period(event
);
5561 if (hwc
->interrupts
== MAX_INTERRUPTS
)
5564 for (; overflow
; overflow
--) {
5565 if (__perf_event_overflow(event
, throttle
,
5568 * We inhibit the overflow from happening when
5569 * hwc->interrupts == MAX_INTERRUPTS.
5577 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
5578 struct perf_sample_data
*data
,
5579 struct pt_regs
*regs
)
5581 struct hw_perf_event
*hwc
= &event
->hw
;
5583 local64_add(nr
, &event
->count
);
5588 if (!is_sampling_event(event
))
5591 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
5593 return perf_swevent_overflow(event
, 1, data
, regs
);
5595 data
->period
= event
->hw
.last_period
;
5597 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
5598 return perf_swevent_overflow(event
, 1, data
, regs
);
5600 if (local64_add_negative(nr
, &hwc
->period_left
))
5603 perf_swevent_overflow(event
, 0, data
, regs
);
5606 static int perf_exclude_event(struct perf_event
*event
,
5607 struct pt_regs
*regs
)
5609 if (event
->hw
.state
& PERF_HES_STOPPED
)
5613 if (event
->attr
.exclude_user
&& user_mode(regs
))
5616 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
5623 static int perf_swevent_match(struct perf_event
*event
,
5624 enum perf_type_id type
,
5626 struct perf_sample_data
*data
,
5627 struct pt_regs
*regs
)
5629 if (event
->attr
.type
!= type
)
5632 if (event
->attr
.config
!= event_id
)
5635 if (perf_exclude_event(event
, regs
))
5641 static inline u64
swevent_hash(u64 type
, u32 event_id
)
5643 u64 val
= event_id
| (type
<< 32);
5645 return hash_64(val
, SWEVENT_HLIST_BITS
);
5648 static inline struct hlist_head
*
5649 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
5651 u64 hash
= swevent_hash(type
, event_id
);
5653 return &hlist
->heads
[hash
];
5656 /* For the read side: events when they trigger */
5657 static inline struct hlist_head
*
5658 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
5660 struct swevent_hlist
*hlist
;
5662 hlist
= rcu_dereference(swhash
->swevent_hlist
);
5666 return __find_swevent_head(hlist
, type
, event_id
);
5669 /* For the event head insertion and removal in the hlist */
5670 static inline struct hlist_head
*
5671 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
5673 struct swevent_hlist
*hlist
;
5674 u32 event_id
= event
->attr
.config
;
5675 u64 type
= event
->attr
.type
;
5678 * Event scheduling is always serialized against hlist allocation
5679 * and release. Which makes the protected version suitable here.
5680 * The context lock guarantees that.
5682 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
5683 lockdep_is_held(&event
->ctx
->lock
));
5687 return __find_swevent_head(hlist
, type
, event_id
);
5690 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
5692 struct perf_sample_data
*data
,
5693 struct pt_regs
*regs
)
5695 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5696 struct perf_event
*event
;
5697 struct hlist_head
*head
;
5700 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
5704 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5705 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
5706 perf_swevent_event(event
, nr
, data
, regs
);
5712 int perf_swevent_get_recursion_context(void)
5714 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5716 return get_recursion_context(swhash
->recursion
);
5718 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
5720 inline void perf_swevent_put_recursion_context(int rctx
)
5722 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5724 put_recursion_context(swhash
->recursion
, rctx
);
5727 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
5729 struct perf_sample_data data
;
5732 preempt_disable_notrace();
5733 rctx
= perf_swevent_get_recursion_context();
5737 perf_sample_data_init(&data
, addr
, 0);
5739 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
5741 perf_swevent_put_recursion_context(rctx
);
5742 preempt_enable_notrace();
5745 static void perf_swevent_read(struct perf_event
*event
)
5749 static int perf_swevent_add(struct perf_event
*event
, int flags
)
5751 struct swevent_htable
*swhash
= &__get_cpu_var(swevent_htable
);
5752 struct hw_perf_event
*hwc
= &event
->hw
;
5753 struct hlist_head
*head
;
5755 if (is_sampling_event(event
)) {
5756 hwc
->last_period
= hwc
->sample_period
;
5757 perf_swevent_set_period(event
);
5760 hwc
->state
= !(flags
& PERF_EF_START
);
5762 head
= find_swevent_head(swhash
, event
);
5765 * We can race with cpu hotplug code. Do not
5766 * WARN if the cpu just got unplugged.
5768 WARN_ON_ONCE(swhash
->online
);
5772 hlist_add_head_rcu(&event
->hlist_entry
, head
);
5777 static void perf_swevent_del(struct perf_event
*event
, int flags
)
5779 hlist_del_rcu(&event
->hlist_entry
);
5782 static void perf_swevent_start(struct perf_event
*event
, int flags
)
5784 event
->hw
.state
= 0;
5787 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
5789 event
->hw
.state
= PERF_HES_STOPPED
;
5792 /* Deref the hlist from the update side */
5793 static inline struct swevent_hlist
*
5794 swevent_hlist_deref(struct swevent_htable
*swhash
)
5796 return rcu_dereference_protected(swhash
->swevent_hlist
,
5797 lockdep_is_held(&swhash
->hlist_mutex
));
5800 static void swevent_hlist_release(struct swevent_htable
*swhash
)
5802 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
5807 rcu_assign_pointer(swhash
->swevent_hlist
, NULL
);
5808 kfree_rcu(hlist
, rcu_head
);
5811 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
5813 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5815 mutex_lock(&swhash
->hlist_mutex
);
5817 if (!--swhash
->hlist_refcount
)
5818 swevent_hlist_release(swhash
);
5820 mutex_unlock(&swhash
->hlist_mutex
);
5823 static void swevent_hlist_put(struct perf_event
*event
)
5827 for_each_possible_cpu(cpu
)
5828 swevent_hlist_put_cpu(event
, cpu
);
5831 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
5833 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
5836 mutex_lock(&swhash
->hlist_mutex
);
5838 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
5839 struct swevent_hlist
*hlist
;
5841 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
5846 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
5848 swhash
->hlist_refcount
++;
5850 mutex_unlock(&swhash
->hlist_mutex
);
5855 static int swevent_hlist_get(struct perf_event
*event
)
5858 int cpu
, failed_cpu
;
5861 for_each_possible_cpu(cpu
) {
5862 err
= swevent_hlist_get_cpu(event
, cpu
);
5872 for_each_possible_cpu(cpu
) {
5873 if (cpu
== failed_cpu
)
5875 swevent_hlist_put_cpu(event
, cpu
);
5882 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
5884 static void sw_perf_event_destroy(struct perf_event
*event
)
5886 u64 event_id
= event
->attr
.config
;
5888 WARN_ON(event
->parent
);
5890 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
5891 swevent_hlist_put(event
);
5894 static int perf_swevent_init(struct perf_event
*event
)
5896 u64 event_id
= event
->attr
.config
;
5898 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
5902 * no branch sampling for software events
5904 if (has_branch_stack(event
))
5908 case PERF_COUNT_SW_CPU_CLOCK
:
5909 case PERF_COUNT_SW_TASK_CLOCK
:
5916 if (event_id
>= PERF_COUNT_SW_MAX
)
5919 if (!event
->parent
) {
5922 err
= swevent_hlist_get(event
);
5926 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
5927 event
->destroy
= sw_perf_event_destroy
;
5933 static int perf_swevent_event_idx(struct perf_event
*event
)
5938 static struct pmu perf_swevent
= {
5939 .task_ctx_nr
= perf_sw_context
,
5941 .event_init
= perf_swevent_init
,
5942 .add
= perf_swevent_add
,
5943 .del
= perf_swevent_del
,
5944 .start
= perf_swevent_start
,
5945 .stop
= perf_swevent_stop
,
5946 .read
= perf_swevent_read
,
5948 .event_idx
= perf_swevent_event_idx
,
5951 #ifdef CONFIG_EVENT_TRACING
5953 static int perf_tp_filter_match(struct perf_event
*event
,
5954 struct perf_sample_data
*data
)
5956 void *record
= data
->raw
->data
;
5958 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
5963 static int perf_tp_event_match(struct perf_event
*event
,
5964 struct perf_sample_data
*data
,
5965 struct pt_regs
*regs
)
5967 if (event
->hw
.state
& PERF_HES_STOPPED
)
5970 * All tracepoints are from kernel-space.
5972 if (event
->attr
.exclude_kernel
)
5975 if (!perf_tp_filter_match(event
, data
))
5981 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
5982 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
5983 struct task_struct
*task
)
5985 struct perf_sample_data data
;
5986 struct perf_event
*event
;
5988 struct perf_raw_record raw
= {
5993 perf_sample_data_init(&data
, addr
, 0);
5996 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
5997 if (perf_tp_event_match(event
, &data
, regs
))
5998 perf_swevent_event(event
, count
, &data
, regs
);
6002 * If we got specified a target task, also iterate its context and
6003 * deliver this event there too.
6005 if (task
&& task
!= current
) {
6006 struct perf_event_context
*ctx
;
6007 struct trace_entry
*entry
= record
;
6010 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6014 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6015 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6017 if (event
->attr
.config
!= entry
->type
)
6019 if (perf_tp_event_match(event
, &data
, regs
))
6020 perf_swevent_event(event
, count
, &data
, regs
);
6026 perf_swevent_put_recursion_context(rctx
);
6028 EXPORT_SYMBOL_GPL(perf_tp_event
);
6030 static void tp_perf_event_destroy(struct perf_event
*event
)
6032 perf_trace_destroy(event
);
6035 static int perf_tp_event_init(struct perf_event
*event
)
6039 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6043 * no branch sampling for tracepoint events
6045 if (has_branch_stack(event
))
6048 err
= perf_trace_init(event
);
6052 event
->destroy
= tp_perf_event_destroy
;
6057 static struct pmu perf_tracepoint
= {
6058 .task_ctx_nr
= perf_sw_context
,
6060 .event_init
= perf_tp_event_init
,
6061 .add
= perf_trace_add
,
6062 .del
= perf_trace_del
,
6063 .start
= perf_swevent_start
,
6064 .stop
= perf_swevent_stop
,
6065 .read
= perf_swevent_read
,
6067 .event_idx
= perf_swevent_event_idx
,
6070 static inline void perf_tp_register(void)
6072 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
6075 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6080 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6083 filter_str
= strndup_user(arg
, PAGE_SIZE
);
6084 if (IS_ERR(filter_str
))
6085 return PTR_ERR(filter_str
);
6087 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
6093 static void perf_event_free_filter(struct perf_event
*event
)
6095 ftrace_profile_free_filter(event
);
6100 static inline void perf_tp_register(void)
6104 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
6109 static void perf_event_free_filter(struct perf_event
*event
)
6113 #endif /* CONFIG_EVENT_TRACING */
6115 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6116 void perf_bp_event(struct perf_event
*bp
, void *data
)
6118 struct perf_sample_data sample
;
6119 struct pt_regs
*regs
= data
;
6121 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
6123 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
6124 perf_swevent_event(bp
, 1, &sample
, regs
);
6129 * hrtimer based swevent callback
6132 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
6134 enum hrtimer_restart ret
= HRTIMER_RESTART
;
6135 struct perf_sample_data data
;
6136 struct pt_regs
*regs
;
6137 struct perf_event
*event
;
6140 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
6142 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
6143 return HRTIMER_NORESTART
;
6145 event
->pmu
->read(event
);
6147 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
6148 regs
= get_irq_regs();
6150 if (regs
&& !perf_exclude_event(event
, regs
)) {
6151 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
6152 if (__perf_event_overflow(event
, 1, &data
, regs
))
6153 ret
= HRTIMER_NORESTART
;
6156 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
6157 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
6162 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
6164 struct hw_perf_event
*hwc
= &event
->hw
;
6167 if (!is_sampling_event(event
))
6170 period
= local64_read(&hwc
->period_left
);
6175 local64_set(&hwc
->period_left
, 0);
6177 period
= max_t(u64
, 10000, hwc
->sample_period
);
6179 __hrtimer_start_range_ns(&hwc
->hrtimer
,
6180 ns_to_ktime(period
), 0,
6181 HRTIMER_MODE_REL_PINNED
, 0);
6184 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
6186 struct hw_perf_event
*hwc
= &event
->hw
;
6188 if (is_sampling_event(event
)) {
6189 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
6190 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
6192 hrtimer_cancel(&hwc
->hrtimer
);
6196 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
6198 struct hw_perf_event
*hwc
= &event
->hw
;
6200 if (!is_sampling_event(event
))
6203 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
6204 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
6207 * Since hrtimers have a fixed rate, we can do a static freq->period
6208 * mapping and avoid the whole period adjust feedback stuff.
6210 if (event
->attr
.freq
) {
6211 long freq
= event
->attr
.sample_freq
;
6213 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
6214 hwc
->sample_period
= event
->attr
.sample_period
;
6215 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6216 hwc
->last_period
= hwc
->sample_period
;
6217 event
->attr
.freq
= 0;
6222 * Software event: cpu wall time clock
6225 static void cpu_clock_event_update(struct perf_event
*event
)
6230 now
= local_clock();
6231 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
6232 local64_add(now
- prev
, &event
->count
);
6235 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
6237 local64_set(&event
->hw
.prev_count
, local_clock());
6238 perf_swevent_start_hrtimer(event
);
6241 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
6243 perf_swevent_cancel_hrtimer(event
);
6244 cpu_clock_event_update(event
);
6247 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
6249 if (flags
& PERF_EF_START
)
6250 cpu_clock_event_start(event
, flags
);
6255 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
6257 cpu_clock_event_stop(event
, flags
);
6260 static void cpu_clock_event_read(struct perf_event
*event
)
6262 cpu_clock_event_update(event
);
6265 static int cpu_clock_event_init(struct perf_event
*event
)
6267 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6270 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
6274 * no branch sampling for software events
6276 if (has_branch_stack(event
))
6279 perf_swevent_init_hrtimer(event
);
6284 static struct pmu perf_cpu_clock
= {
6285 .task_ctx_nr
= perf_sw_context
,
6287 .event_init
= cpu_clock_event_init
,
6288 .add
= cpu_clock_event_add
,
6289 .del
= cpu_clock_event_del
,
6290 .start
= cpu_clock_event_start
,
6291 .stop
= cpu_clock_event_stop
,
6292 .read
= cpu_clock_event_read
,
6294 .event_idx
= perf_swevent_event_idx
,
6298 * Software event: task time clock
6301 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
6306 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
6308 local64_add(delta
, &event
->count
);
6311 static void task_clock_event_start(struct perf_event
*event
, int flags
)
6313 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
6314 perf_swevent_start_hrtimer(event
);
6317 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
6319 perf_swevent_cancel_hrtimer(event
);
6320 task_clock_event_update(event
, event
->ctx
->time
);
6323 static int task_clock_event_add(struct perf_event
*event
, int flags
)
6325 if (flags
& PERF_EF_START
)
6326 task_clock_event_start(event
, flags
);
6331 static void task_clock_event_del(struct perf_event
*event
, int flags
)
6333 task_clock_event_stop(event
, PERF_EF_UPDATE
);
6336 static void task_clock_event_read(struct perf_event
*event
)
6338 u64 now
= perf_clock();
6339 u64 delta
= now
- event
->ctx
->timestamp
;
6340 u64 time
= event
->ctx
->time
+ delta
;
6342 task_clock_event_update(event
, time
);
6345 static int task_clock_event_init(struct perf_event
*event
)
6347 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6350 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
6354 * no branch sampling for software events
6356 if (has_branch_stack(event
))
6359 perf_swevent_init_hrtimer(event
);
6364 static struct pmu perf_task_clock
= {
6365 .task_ctx_nr
= perf_sw_context
,
6367 .event_init
= task_clock_event_init
,
6368 .add
= task_clock_event_add
,
6369 .del
= task_clock_event_del
,
6370 .start
= task_clock_event_start
,
6371 .stop
= task_clock_event_stop
,
6372 .read
= task_clock_event_read
,
6374 .event_idx
= perf_swevent_event_idx
,
6377 static void perf_pmu_nop_void(struct pmu
*pmu
)
6381 static int perf_pmu_nop_int(struct pmu
*pmu
)
6386 static void perf_pmu_start_txn(struct pmu
*pmu
)
6388 perf_pmu_disable(pmu
);
6391 static int perf_pmu_commit_txn(struct pmu
*pmu
)
6393 perf_pmu_enable(pmu
);
6397 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
6399 perf_pmu_enable(pmu
);
6402 static int perf_event_idx_default(struct perf_event
*event
)
6404 return event
->hw
.idx
+ 1;
6408 * Ensures all contexts with the same task_ctx_nr have the same
6409 * pmu_cpu_context too.
6411 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
6418 list_for_each_entry(pmu
, &pmus
, entry
) {
6419 if (pmu
->task_ctx_nr
== ctxn
)
6420 return pmu
->pmu_cpu_context
;
6426 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
6430 for_each_possible_cpu(cpu
) {
6431 struct perf_cpu_context
*cpuctx
;
6433 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6435 if (cpuctx
->unique_pmu
== old_pmu
)
6436 cpuctx
->unique_pmu
= pmu
;
6440 static void free_pmu_context(struct pmu
*pmu
)
6444 mutex_lock(&pmus_lock
);
6446 * Like a real lame refcount.
6448 list_for_each_entry(i
, &pmus
, entry
) {
6449 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
6450 update_pmu_context(i
, pmu
);
6455 free_percpu(pmu
->pmu_cpu_context
);
6457 mutex_unlock(&pmus_lock
);
6459 static struct idr pmu_idr
;
6462 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
6464 struct pmu
*pmu
= dev_get_drvdata(dev
);
6466 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
6468 static DEVICE_ATTR_RO(type
);
6471 perf_event_mux_interval_ms_show(struct device
*dev
,
6472 struct device_attribute
*attr
,
6475 struct pmu
*pmu
= dev_get_drvdata(dev
);
6477 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
6481 perf_event_mux_interval_ms_store(struct device
*dev
,
6482 struct device_attribute
*attr
,
6483 const char *buf
, size_t count
)
6485 struct pmu
*pmu
= dev_get_drvdata(dev
);
6486 int timer
, cpu
, ret
;
6488 ret
= kstrtoint(buf
, 0, &timer
);
6495 /* same value, noting to do */
6496 if (timer
== pmu
->hrtimer_interval_ms
)
6499 pmu
->hrtimer_interval_ms
= timer
;
6501 /* update all cpuctx for this PMU */
6502 for_each_possible_cpu(cpu
) {
6503 struct perf_cpu_context
*cpuctx
;
6504 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6505 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
6507 if (hrtimer_active(&cpuctx
->hrtimer
))
6508 hrtimer_forward_now(&cpuctx
->hrtimer
, cpuctx
->hrtimer_interval
);
6513 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
6515 static struct attribute
*pmu_dev_attrs
[] = {
6516 &dev_attr_type
.attr
,
6517 &dev_attr_perf_event_mux_interval_ms
.attr
,
6520 ATTRIBUTE_GROUPS(pmu_dev
);
6522 static int pmu_bus_running
;
6523 static struct bus_type pmu_bus
= {
6524 .name
= "event_source",
6525 .dev_groups
= pmu_dev_groups
,
6528 static void pmu_dev_release(struct device
*dev
)
6533 static int pmu_dev_alloc(struct pmu
*pmu
)
6537 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
6541 pmu
->dev
->groups
= pmu
->attr_groups
;
6542 device_initialize(pmu
->dev
);
6543 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
6547 dev_set_drvdata(pmu
->dev
, pmu
);
6548 pmu
->dev
->bus
= &pmu_bus
;
6549 pmu
->dev
->release
= pmu_dev_release
;
6550 ret
= device_add(pmu
->dev
);
6558 put_device(pmu
->dev
);
6562 static struct lock_class_key cpuctx_mutex
;
6563 static struct lock_class_key cpuctx_lock
;
6565 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
6569 mutex_lock(&pmus_lock
);
6571 pmu
->pmu_disable_count
= alloc_percpu(int);
6572 if (!pmu
->pmu_disable_count
)
6581 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
6589 if (pmu_bus_running
) {
6590 ret
= pmu_dev_alloc(pmu
);
6596 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
6597 if (pmu
->pmu_cpu_context
)
6598 goto got_cpu_context
;
6601 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
6602 if (!pmu
->pmu_cpu_context
)
6605 for_each_possible_cpu(cpu
) {
6606 struct perf_cpu_context
*cpuctx
;
6608 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
6609 __perf_event_init_context(&cpuctx
->ctx
);
6610 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
6611 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
6612 cpuctx
->ctx
.type
= cpu_context
;
6613 cpuctx
->ctx
.pmu
= pmu
;
6615 __perf_cpu_hrtimer_init(cpuctx
, cpu
);
6617 INIT_LIST_HEAD(&cpuctx
->rotation_list
);
6618 cpuctx
->unique_pmu
= pmu
;
6622 if (!pmu
->start_txn
) {
6623 if (pmu
->pmu_enable
) {
6625 * If we have pmu_enable/pmu_disable calls, install
6626 * transaction stubs that use that to try and batch
6627 * hardware accesses.
6629 pmu
->start_txn
= perf_pmu_start_txn
;
6630 pmu
->commit_txn
= perf_pmu_commit_txn
;
6631 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
6633 pmu
->start_txn
= perf_pmu_nop_void
;
6634 pmu
->commit_txn
= perf_pmu_nop_int
;
6635 pmu
->cancel_txn
= perf_pmu_nop_void
;
6639 if (!pmu
->pmu_enable
) {
6640 pmu
->pmu_enable
= perf_pmu_nop_void
;
6641 pmu
->pmu_disable
= perf_pmu_nop_void
;
6644 if (!pmu
->event_idx
)
6645 pmu
->event_idx
= perf_event_idx_default
;
6647 list_add_rcu(&pmu
->entry
, &pmus
);
6650 mutex_unlock(&pmus_lock
);
6655 device_del(pmu
->dev
);
6656 put_device(pmu
->dev
);
6659 if (pmu
->type
>= PERF_TYPE_MAX
)
6660 idr_remove(&pmu_idr
, pmu
->type
);
6663 free_percpu(pmu
->pmu_disable_count
);
6666 EXPORT_SYMBOL_GPL(perf_pmu_register
);
6668 void perf_pmu_unregister(struct pmu
*pmu
)
6670 mutex_lock(&pmus_lock
);
6671 list_del_rcu(&pmu
->entry
);
6672 mutex_unlock(&pmus_lock
);
6675 * We dereference the pmu list under both SRCU and regular RCU, so
6676 * synchronize against both of those.
6678 synchronize_srcu(&pmus_srcu
);
6681 free_percpu(pmu
->pmu_disable_count
);
6682 if (pmu
->type
>= PERF_TYPE_MAX
)
6683 idr_remove(&pmu_idr
, pmu
->type
);
6684 device_del(pmu
->dev
);
6685 put_device(pmu
->dev
);
6686 free_pmu_context(pmu
);
6688 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
6690 struct pmu
*perf_init_event(struct perf_event
*event
)
6692 struct pmu
*pmu
= NULL
;
6696 idx
= srcu_read_lock(&pmus_srcu
);
6699 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
6702 if (!try_module_get(pmu
->module
)) {
6703 pmu
= ERR_PTR(-ENODEV
);
6707 ret
= pmu
->event_init(event
);
6713 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
6714 if (!try_module_get(pmu
->module
)) {
6715 pmu
= ERR_PTR(-ENODEV
);
6719 ret
= pmu
->event_init(event
);
6723 if (ret
!= -ENOENT
) {
6728 pmu
= ERR_PTR(-ENOENT
);
6730 srcu_read_unlock(&pmus_srcu
, idx
);
6735 static void account_event_cpu(struct perf_event
*event
, int cpu
)
6740 if (has_branch_stack(event
)) {
6741 if (!(event
->attach_state
& PERF_ATTACH_TASK
))
6742 atomic_inc(&per_cpu(perf_branch_stack_events
, cpu
));
6744 if (is_cgroup_event(event
))
6745 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
6748 static void account_event(struct perf_event
*event
)
6753 if (event
->attach_state
& PERF_ATTACH_TASK
)
6754 static_key_slow_inc(&perf_sched_events
.key
);
6755 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
6756 atomic_inc(&nr_mmap_events
);
6757 if (event
->attr
.comm
)
6758 atomic_inc(&nr_comm_events
);
6759 if (event
->attr
.task
)
6760 atomic_inc(&nr_task_events
);
6761 if (event
->attr
.freq
) {
6762 if (atomic_inc_return(&nr_freq_events
) == 1)
6763 tick_nohz_full_kick_all();
6765 if (has_branch_stack(event
))
6766 static_key_slow_inc(&perf_sched_events
.key
);
6767 if (is_cgroup_event(event
))
6768 static_key_slow_inc(&perf_sched_events
.key
);
6770 account_event_cpu(event
, event
->cpu
);
6774 * Allocate and initialize a event structure
6776 static struct perf_event
*
6777 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
6778 struct task_struct
*task
,
6779 struct perf_event
*group_leader
,
6780 struct perf_event
*parent_event
,
6781 perf_overflow_handler_t overflow_handler
,
6785 struct perf_event
*event
;
6786 struct hw_perf_event
*hwc
;
6789 if ((unsigned)cpu
>= nr_cpu_ids
) {
6790 if (!task
|| cpu
!= -1)
6791 return ERR_PTR(-EINVAL
);
6794 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
6796 return ERR_PTR(-ENOMEM
);
6799 * Single events are their own group leaders, with an
6800 * empty sibling list:
6803 group_leader
= event
;
6805 mutex_init(&event
->child_mutex
);
6806 INIT_LIST_HEAD(&event
->child_list
);
6808 INIT_LIST_HEAD(&event
->group_entry
);
6809 INIT_LIST_HEAD(&event
->event_entry
);
6810 INIT_LIST_HEAD(&event
->sibling_list
);
6811 INIT_LIST_HEAD(&event
->rb_entry
);
6812 INIT_LIST_HEAD(&event
->active_entry
);
6813 INIT_HLIST_NODE(&event
->hlist_entry
);
6816 init_waitqueue_head(&event
->waitq
);
6817 init_irq_work(&event
->pending
, perf_pending_event
);
6819 mutex_init(&event
->mmap_mutex
);
6821 atomic_long_set(&event
->refcount
, 1);
6823 event
->attr
= *attr
;
6824 event
->group_leader
= group_leader
;
6828 event
->parent
= parent_event
;
6830 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
6831 event
->id
= atomic64_inc_return(&perf_event_id
);
6833 event
->state
= PERF_EVENT_STATE_INACTIVE
;
6836 event
->attach_state
= PERF_ATTACH_TASK
;
6838 if (attr
->type
== PERF_TYPE_TRACEPOINT
)
6839 event
->hw
.tp_target
= task
;
6840 #ifdef CONFIG_HAVE_HW_BREAKPOINT
6842 * hw_breakpoint is a bit difficult here..
6844 else if (attr
->type
== PERF_TYPE_BREAKPOINT
)
6845 event
->hw
.bp_target
= task
;
6849 if (!overflow_handler
&& parent_event
) {
6850 overflow_handler
= parent_event
->overflow_handler
;
6851 context
= parent_event
->overflow_handler_context
;
6854 event
->overflow_handler
= overflow_handler
;
6855 event
->overflow_handler_context
= context
;
6857 perf_event__state_init(event
);
6862 hwc
->sample_period
= attr
->sample_period
;
6863 if (attr
->freq
&& attr
->sample_freq
)
6864 hwc
->sample_period
= 1;
6865 hwc
->last_period
= hwc
->sample_period
;
6867 local64_set(&hwc
->period_left
, hwc
->sample_period
);
6870 * we currently do not support PERF_FORMAT_GROUP on inherited events
6872 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
6875 pmu
= perf_init_event(event
);
6878 else if (IS_ERR(pmu
)) {
6883 if (!event
->parent
) {
6884 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
6885 err
= get_callchain_buffers();
6895 event
->destroy(event
);
6896 module_put(pmu
->module
);
6899 put_pid_ns(event
->ns
);
6902 return ERR_PTR(err
);
6905 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
6906 struct perf_event_attr
*attr
)
6911 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
6915 * zero the full structure, so that a short copy will be nice.
6917 memset(attr
, 0, sizeof(*attr
));
6919 ret
= get_user(size
, &uattr
->size
);
6923 if (size
> PAGE_SIZE
) /* silly large */
6926 if (!size
) /* abi compat */
6927 size
= PERF_ATTR_SIZE_VER0
;
6929 if (size
< PERF_ATTR_SIZE_VER0
)
6933 * If we're handed a bigger struct than we know of,
6934 * ensure all the unknown bits are 0 - i.e. new
6935 * user-space does not rely on any kernel feature
6936 * extensions we dont know about yet.
6938 if (size
> sizeof(*attr
)) {
6939 unsigned char __user
*addr
;
6940 unsigned char __user
*end
;
6943 addr
= (void __user
*)uattr
+ sizeof(*attr
);
6944 end
= (void __user
*)uattr
+ size
;
6946 for (; addr
< end
; addr
++) {
6947 ret
= get_user(val
, addr
);
6953 size
= sizeof(*attr
);
6956 ret
= copy_from_user(attr
, uattr
, size
);
6960 if (attr
->__reserved_1
)
6963 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
6966 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
6969 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
6970 u64 mask
= attr
->branch_sample_type
;
6972 /* only using defined bits */
6973 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
6976 /* at least one branch bit must be set */
6977 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
6980 /* propagate priv level, when not set for branch */
6981 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
6983 /* exclude_kernel checked on syscall entry */
6984 if (!attr
->exclude_kernel
)
6985 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
6987 if (!attr
->exclude_user
)
6988 mask
|= PERF_SAMPLE_BRANCH_USER
;
6990 if (!attr
->exclude_hv
)
6991 mask
|= PERF_SAMPLE_BRANCH_HV
;
6993 * adjust user setting (for HW filter setup)
6995 attr
->branch_sample_type
= mask
;
6997 /* privileged levels capture (kernel, hv): check permissions */
6998 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
6999 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
7003 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
7004 ret
= perf_reg_validate(attr
->sample_regs_user
);
7009 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
7010 if (!arch_perf_have_user_stack_dump())
7014 * We have __u32 type for the size, but so far
7015 * we can only use __u16 as maximum due to the
7016 * __u16 sample size limit.
7018 if (attr
->sample_stack_user
>= USHRT_MAX
)
7020 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
7028 put_user(sizeof(*attr
), &uattr
->size
);
7034 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
7036 struct ring_buffer
*rb
= NULL
;
7042 /* don't allow circular references */
7043 if (event
== output_event
)
7047 * Don't allow cross-cpu buffers
7049 if (output_event
->cpu
!= event
->cpu
)
7053 * If its not a per-cpu rb, it must be the same task.
7055 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
7059 mutex_lock(&event
->mmap_mutex
);
7060 /* Can't redirect output if we've got an active mmap() */
7061 if (atomic_read(&event
->mmap_count
))
7065 /* get the rb we want to redirect to */
7066 rb
= ring_buffer_get(output_event
);
7071 ring_buffer_attach(event
, rb
);
7075 mutex_unlock(&event
->mmap_mutex
);
7082 * sys_perf_event_open - open a performance event, associate it to a task/cpu
7084 * @attr_uptr: event_id type attributes for monitoring/sampling
7087 * @group_fd: group leader event fd
7089 SYSCALL_DEFINE5(perf_event_open
,
7090 struct perf_event_attr __user
*, attr_uptr
,
7091 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
7093 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
7094 struct perf_event
*event
, *sibling
;
7095 struct perf_event_attr attr
;
7096 struct perf_event_context
*ctx
;
7097 struct file
*event_file
= NULL
;
7098 struct fd group
= {NULL
, 0};
7099 struct task_struct
*task
= NULL
;
7104 int f_flags
= O_RDWR
;
7106 /* for future expandability... */
7107 if (flags
& ~PERF_FLAG_ALL
)
7110 err
= perf_copy_attr(attr_uptr
, &attr
);
7114 if (!attr
.exclude_kernel
) {
7115 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
7120 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
7123 if (attr
.sample_period
& (1ULL << 63))
7128 * In cgroup mode, the pid argument is used to pass the fd
7129 * opened to the cgroup directory in cgroupfs. The cpu argument
7130 * designates the cpu on which to monitor threads from that
7133 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
7136 if (flags
& PERF_FLAG_FD_CLOEXEC
)
7137 f_flags
|= O_CLOEXEC
;
7139 event_fd
= get_unused_fd_flags(f_flags
);
7143 if (group_fd
!= -1) {
7144 err
= perf_fget_light(group_fd
, &group
);
7147 group_leader
= group
.file
->private_data
;
7148 if (flags
& PERF_FLAG_FD_OUTPUT
)
7149 output_event
= group_leader
;
7150 if (flags
& PERF_FLAG_FD_NO_GROUP
)
7151 group_leader
= NULL
;
7154 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
7155 task
= find_lively_task_by_vpid(pid
);
7157 err
= PTR_ERR(task
);
7162 if (task
&& group_leader
&&
7163 group_leader
->attr
.inherit
!= attr
.inherit
) {
7170 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
7172 if (IS_ERR(event
)) {
7173 err
= PTR_ERR(event
);
7177 if (flags
& PERF_FLAG_PID_CGROUP
) {
7178 err
= perf_cgroup_connect(pid
, event
, &attr
, group_leader
);
7180 __free_event(event
);
7185 if (is_sampling_event(event
)) {
7186 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
7192 account_event(event
);
7195 * Special case software events and allow them to be part of
7196 * any hardware group.
7201 (is_software_event(event
) != is_software_event(group_leader
))) {
7202 if (is_software_event(event
)) {
7204 * If event and group_leader are not both a software
7205 * event, and event is, then group leader is not.
7207 * Allow the addition of software events to !software
7208 * groups, this is safe because software events never
7211 pmu
= group_leader
->pmu
;
7212 } else if (is_software_event(group_leader
) &&
7213 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
7215 * In case the group is a pure software group, and we
7216 * try to add a hardware event, move the whole group to
7217 * the hardware context.
7224 * Get the target context (task or percpu):
7226 ctx
= find_get_context(pmu
, task
, event
->cpu
);
7233 put_task_struct(task
);
7238 * Look up the group leader (we will attach this event to it):
7244 * Do not allow a recursive hierarchy (this new sibling
7245 * becoming part of another group-sibling):
7247 if (group_leader
->group_leader
!= group_leader
)
7250 * Do not allow to attach to a group in a different
7251 * task or CPU context:
7254 if (group_leader
->ctx
->type
!= ctx
->type
)
7257 if (group_leader
->ctx
!= ctx
)
7262 * Only a group leader can be exclusive or pinned
7264 if (attr
.exclusive
|| attr
.pinned
)
7269 err
= perf_event_set_output(event
, output_event
);
7274 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
7276 if (IS_ERR(event_file
)) {
7277 err
= PTR_ERR(event_file
);
7282 struct perf_event_context
*gctx
= group_leader
->ctx
;
7284 mutex_lock(&gctx
->mutex
);
7285 perf_remove_from_context(group_leader
, false);
7288 * Removing from the context ends up with disabled
7289 * event. What we want here is event in the initial
7290 * startup state, ready to be add into new context.
7292 perf_event__state_init(group_leader
);
7293 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
7295 perf_remove_from_context(sibling
, false);
7296 perf_event__state_init(sibling
);
7299 mutex_unlock(&gctx
->mutex
);
7303 WARN_ON_ONCE(ctx
->parent_ctx
);
7304 mutex_lock(&ctx
->mutex
);
7308 perf_install_in_context(ctx
, group_leader
, event
->cpu
);
7310 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
7312 perf_install_in_context(ctx
, sibling
, event
->cpu
);
7317 perf_install_in_context(ctx
, event
, event
->cpu
);
7318 perf_unpin_context(ctx
);
7319 mutex_unlock(&ctx
->mutex
);
7323 event
->owner
= current
;
7325 mutex_lock(¤t
->perf_event_mutex
);
7326 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
7327 mutex_unlock(¤t
->perf_event_mutex
);
7330 * Precalculate sample_data sizes
7332 perf_event__header_size(event
);
7333 perf_event__id_header_size(event
);
7336 * Drop the reference on the group_event after placing the
7337 * new event on the sibling_list. This ensures destruction
7338 * of the group leader will find the pointer to itself in
7339 * perf_group_detach().
7342 fd_install(event_fd
, event_file
);
7346 perf_unpin_context(ctx
);
7354 put_task_struct(task
);
7358 put_unused_fd(event_fd
);
7363 * perf_event_create_kernel_counter
7365 * @attr: attributes of the counter to create
7366 * @cpu: cpu in which the counter is bound
7367 * @task: task to profile (NULL for percpu)
7370 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
7371 struct task_struct
*task
,
7372 perf_overflow_handler_t overflow_handler
,
7375 struct perf_event_context
*ctx
;
7376 struct perf_event
*event
;
7380 * Get the target context (task or percpu):
7383 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
7384 overflow_handler
, context
);
7385 if (IS_ERR(event
)) {
7386 err
= PTR_ERR(event
);
7390 account_event(event
);
7392 ctx
= find_get_context(event
->pmu
, task
, cpu
);
7398 WARN_ON_ONCE(ctx
->parent_ctx
);
7399 mutex_lock(&ctx
->mutex
);
7400 perf_install_in_context(ctx
, event
, cpu
);
7401 perf_unpin_context(ctx
);
7402 mutex_unlock(&ctx
->mutex
);
7409 return ERR_PTR(err
);
7411 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
7413 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
7415 struct perf_event_context
*src_ctx
;
7416 struct perf_event_context
*dst_ctx
;
7417 struct perf_event
*event
, *tmp
;
7420 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
7421 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
7423 mutex_lock(&src_ctx
->mutex
);
7424 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
7426 perf_remove_from_context(event
, false);
7427 unaccount_event_cpu(event
, src_cpu
);
7429 list_add(&event
->migrate_entry
, &events
);
7431 mutex_unlock(&src_ctx
->mutex
);
7435 mutex_lock(&dst_ctx
->mutex
);
7436 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
7437 list_del(&event
->migrate_entry
);
7438 if (event
->state
>= PERF_EVENT_STATE_OFF
)
7439 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7440 account_event_cpu(event
, dst_cpu
);
7441 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
7444 mutex_unlock(&dst_ctx
->mutex
);
7446 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
7448 static void sync_child_event(struct perf_event
*child_event
,
7449 struct task_struct
*child
)
7451 struct perf_event
*parent_event
= child_event
->parent
;
7454 if (child_event
->attr
.inherit_stat
)
7455 perf_event_read_event(child_event
, child
);
7457 child_val
= perf_event_count(child_event
);
7460 * Add back the child's count to the parent's count:
7462 atomic64_add(child_val
, &parent_event
->child_count
);
7463 atomic64_add(child_event
->total_time_enabled
,
7464 &parent_event
->child_total_time_enabled
);
7465 atomic64_add(child_event
->total_time_running
,
7466 &parent_event
->child_total_time_running
);
7469 * Remove this event from the parent's list
7471 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7472 mutex_lock(&parent_event
->child_mutex
);
7473 list_del_init(&child_event
->child_list
);
7474 mutex_unlock(&parent_event
->child_mutex
);
7477 * Release the parent event, if this was the last
7480 put_event(parent_event
);
7484 __perf_event_exit_task(struct perf_event
*child_event
,
7485 struct perf_event_context
*child_ctx
,
7486 struct task_struct
*child
)
7489 * Do not destroy the 'original' grouping; because of the context
7490 * switch optimization the original events could've ended up in a
7491 * random child task.
7493 * If we were to destroy the original group, all group related
7494 * operations would cease to function properly after this random
7497 * Do destroy all inherited groups, we don't care about those
7498 * and being thorough is better.
7500 perf_remove_from_context(child_event
, !!child_event
->parent
);
7503 * It can happen that the parent exits first, and has events
7504 * that are still around due to the child reference. These
7505 * events need to be zapped.
7507 if (child_event
->parent
) {
7508 sync_child_event(child_event
, child
);
7509 free_event(child_event
);
7513 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
7515 struct perf_event
*child_event
, *next
;
7516 struct perf_event_context
*child_ctx
, *parent_ctx
;
7517 unsigned long flags
;
7519 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
7520 perf_event_task(child
, NULL
, 0);
7524 local_irq_save(flags
);
7526 * We can't reschedule here because interrupts are disabled,
7527 * and either child is current or it is a task that can't be
7528 * scheduled, so we are now safe from rescheduling changing
7531 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
7534 * Take the context lock here so that if find_get_context is
7535 * reading child->perf_event_ctxp, we wait until it has
7536 * incremented the context's refcount before we do put_ctx below.
7538 raw_spin_lock(&child_ctx
->lock
);
7539 task_ctx_sched_out(child_ctx
);
7540 child
->perf_event_ctxp
[ctxn
] = NULL
;
7543 * In order to avoid freeing: child_ctx->parent_ctx->task
7544 * under perf_event_context::lock, grab another reference.
7546 parent_ctx
= child_ctx
->parent_ctx
;
7548 get_ctx(parent_ctx
);
7551 * If this context is a clone; unclone it so it can't get
7552 * swapped to another process while we're removing all
7553 * the events from it.
7555 unclone_ctx(child_ctx
);
7556 update_context_time(child_ctx
);
7557 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
7560 * Now that we no longer hold perf_event_context::lock, drop
7561 * our extra child_ctx->parent_ctx reference.
7564 put_ctx(parent_ctx
);
7567 * Report the task dead after unscheduling the events so that we
7568 * won't get any samples after PERF_RECORD_EXIT. We can however still
7569 * get a few PERF_RECORD_READ events.
7571 perf_event_task(child
, child_ctx
, 0);
7574 * We can recurse on the same lock type through:
7576 * __perf_event_exit_task()
7577 * sync_child_event()
7579 * mutex_lock(&ctx->mutex)
7581 * But since its the parent context it won't be the same instance.
7583 mutex_lock(&child_ctx
->mutex
);
7585 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
7586 __perf_event_exit_task(child_event
, child_ctx
, child
);
7588 mutex_unlock(&child_ctx
->mutex
);
7594 * When a child task exits, feed back event values to parent events.
7596 void perf_event_exit_task(struct task_struct
*child
)
7598 struct perf_event
*event
, *tmp
;
7601 mutex_lock(&child
->perf_event_mutex
);
7602 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
7604 list_del_init(&event
->owner_entry
);
7607 * Ensure the list deletion is visible before we clear
7608 * the owner, closes a race against perf_release() where
7609 * we need to serialize on the owner->perf_event_mutex.
7612 event
->owner
= NULL
;
7614 mutex_unlock(&child
->perf_event_mutex
);
7616 for_each_task_context_nr(ctxn
)
7617 perf_event_exit_task_context(child
, ctxn
);
7620 static void perf_free_event(struct perf_event
*event
,
7621 struct perf_event_context
*ctx
)
7623 struct perf_event
*parent
= event
->parent
;
7625 if (WARN_ON_ONCE(!parent
))
7628 mutex_lock(&parent
->child_mutex
);
7629 list_del_init(&event
->child_list
);
7630 mutex_unlock(&parent
->child_mutex
);
7634 perf_group_detach(event
);
7635 list_del_event(event
, ctx
);
7640 * free an unexposed, unused context as created by inheritance by
7641 * perf_event_init_task below, used by fork() in case of fail.
7643 void perf_event_free_task(struct task_struct
*task
)
7645 struct perf_event_context
*ctx
;
7646 struct perf_event
*event
, *tmp
;
7649 for_each_task_context_nr(ctxn
) {
7650 ctx
= task
->perf_event_ctxp
[ctxn
];
7654 mutex_lock(&ctx
->mutex
);
7656 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
7658 perf_free_event(event
, ctx
);
7660 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
7662 perf_free_event(event
, ctx
);
7664 if (!list_empty(&ctx
->pinned_groups
) ||
7665 !list_empty(&ctx
->flexible_groups
))
7668 mutex_unlock(&ctx
->mutex
);
7674 void perf_event_delayed_put(struct task_struct
*task
)
7678 for_each_task_context_nr(ctxn
)
7679 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
7683 * inherit a event from parent task to child task:
7685 static struct perf_event
*
7686 inherit_event(struct perf_event
*parent_event
,
7687 struct task_struct
*parent
,
7688 struct perf_event_context
*parent_ctx
,
7689 struct task_struct
*child
,
7690 struct perf_event
*group_leader
,
7691 struct perf_event_context
*child_ctx
)
7693 struct perf_event
*child_event
;
7694 unsigned long flags
;
7697 * Instead of creating recursive hierarchies of events,
7698 * we link inherited events back to the original parent,
7699 * which has a filp for sure, which we use as the reference
7702 if (parent_event
->parent
)
7703 parent_event
= parent_event
->parent
;
7705 child_event
= perf_event_alloc(&parent_event
->attr
,
7708 group_leader
, parent_event
,
7710 if (IS_ERR(child_event
))
7713 if (!atomic_long_inc_not_zero(&parent_event
->refcount
)) {
7714 free_event(child_event
);
7721 * Make the child state follow the state of the parent event,
7722 * not its attr.disabled bit. We hold the parent's mutex,
7723 * so we won't race with perf_event_{en, dis}able_family.
7725 if (parent_event
->state
>= PERF_EVENT_STATE_INACTIVE
)
7726 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
7728 child_event
->state
= PERF_EVENT_STATE_OFF
;
7730 if (parent_event
->attr
.freq
) {
7731 u64 sample_period
= parent_event
->hw
.sample_period
;
7732 struct hw_perf_event
*hwc
= &child_event
->hw
;
7734 hwc
->sample_period
= sample_period
;
7735 hwc
->last_period
= sample_period
;
7737 local64_set(&hwc
->period_left
, sample_period
);
7740 child_event
->ctx
= child_ctx
;
7741 child_event
->overflow_handler
= parent_event
->overflow_handler
;
7742 child_event
->overflow_handler_context
7743 = parent_event
->overflow_handler_context
;
7746 * Precalculate sample_data sizes
7748 perf_event__header_size(child_event
);
7749 perf_event__id_header_size(child_event
);
7752 * Link it up in the child's context:
7754 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
7755 add_event_to_ctx(child_event
, child_ctx
);
7756 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
7759 * Link this into the parent event's child list
7761 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
7762 mutex_lock(&parent_event
->child_mutex
);
7763 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
7764 mutex_unlock(&parent_event
->child_mutex
);
7769 static int inherit_group(struct perf_event
*parent_event
,
7770 struct task_struct
*parent
,
7771 struct perf_event_context
*parent_ctx
,
7772 struct task_struct
*child
,
7773 struct perf_event_context
*child_ctx
)
7775 struct perf_event
*leader
;
7776 struct perf_event
*sub
;
7777 struct perf_event
*child_ctr
;
7779 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
7780 child
, NULL
, child_ctx
);
7782 return PTR_ERR(leader
);
7783 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
7784 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
7785 child
, leader
, child_ctx
);
7786 if (IS_ERR(child_ctr
))
7787 return PTR_ERR(child_ctr
);
7793 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
7794 struct perf_event_context
*parent_ctx
,
7795 struct task_struct
*child
, int ctxn
,
7799 struct perf_event_context
*child_ctx
;
7801 if (!event
->attr
.inherit
) {
7806 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7809 * This is executed from the parent task context, so
7810 * inherit events that have been marked for cloning.
7811 * First allocate and initialize a context for the
7815 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
7819 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
7822 ret
= inherit_group(event
, parent
, parent_ctx
,
7832 * Initialize the perf_event context in task_struct
7834 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
7836 struct perf_event_context
*child_ctx
, *parent_ctx
;
7837 struct perf_event_context
*cloned_ctx
;
7838 struct perf_event
*event
;
7839 struct task_struct
*parent
= current
;
7840 int inherited_all
= 1;
7841 unsigned long flags
;
7844 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
7848 * If the parent's context is a clone, pin it so it won't get
7851 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
7856 * No need to check if parent_ctx != NULL here; since we saw
7857 * it non-NULL earlier, the only reason for it to become NULL
7858 * is if we exit, and since we're currently in the middle of
7859 * a fork we can't be exiting at the same time.
7863 * Lock the parent list. No need to lock the child - not PID
7864 * hashed yet and not running, so nobody can access it.
7866 mutex_lock(&parent_ctx
->mutex
);
7869 * We dont have to disable NMIs - we are only looking at
7870 * the list, not manipulating it:
7872 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
7873 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7874 child
, ctxn
, &inherited_all
);
7880 * We can't hold ctx->lock when iterating the ->flexible_group list due
7881 * to allocations, but we need to prevent rotation because
7882 * rotate_ctx() will change the list from interrupt context.
7884 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7885 parent_ctx
->rotate_disable
= 1;
7886 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7888 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
7889 ret
= inherit_task_group(event
, parent
, parent_ctx
,
7890 child
, ctxn
, &inherited_all
);
7895 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
7896 parent_ctx
->rotate_disable
= 0;
7898 child_ctx
= child
->perf_event_ctxp
[ctxn
];
7900 if (child_ctx
&& inherited_all
) {
7902 * Mark the child context as a clone of the parent
7903 * context, or of whatever the parent is a clone of.
7905 * Note that if the parent is a clone, the holding of
7906 * parent_ctx->lock avoids it from being uncloned.
7908 cloned_ctx
= parent_ctx
->parent_ctx
;
7910 child_ctx
->parent_ctx
= cloned_ctx
;
7911 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
7913 child_ctx
->parent_ctx
= parent_ctx
;
7914 child_ctx
->parent_gen
= parent_ctx
->generation
;
7916 get_ctx(child_ctx
->parent_ctx
);
7919 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
7920 mutex_unlock(&parent_ctx
->mutex
);
7922 perf_unpin_context(parent_ctx
);
7923 put_ctx(parent_ctx
);
7929 * Initialize the perf_event context in task_struct
7931 int perf_event_init_task(struct task_struct
*child
)
7935 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
7936 mutex_init(&child
->perf_event_mutex
);
7937 INIT_LIST_HEAD(&child
->perf_event_list
);
7939 for_each_task_context_nr(ctxn
) {
7940 ret
= perf_event_init_context(child
, ctxn
);
7948 static void __init
perf_event_init_all_cpus(void)
7950 struct swevent_htable
*swhash
;
7953 for_each_possible_cpu(cpu
) {
7954 swhash
= &per_cpu(swevent_htable
, cpu
);
7955 mutex_init(&swhash
->hlist_mutex
);
7956 INIT_LIST_HEAD(&per_cpu(rotation_list
, cpu
));
7960 static void perf_event_init_cpu(int cpu
)
7962 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
7964 mutex_lock(&swhash
->hlist_mutex
);
7965 swhash
->online
= true;
7966 if (swhash
->hlist_refcount
> 0) {
7967 struct swevent_hlist
*hlist
;
7969 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
7971 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
7973 mutex_unlock(&swhash
->hlist_mutex
);
7976 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
7977 static void perf_pmu_rotate_stop(struct pmu
*pmu
)
7979 struct perf_cpu_context
*cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
7981 WARN_ON(!irqs_disabled());
7983 list_del_init(&cpuctx
->rotation_list
);
7986 static void __perf_event_exit_context(void *__info
)
7988 struct remove_event re
= { .detach_group
= false };
7989 struct perf_event_context
*ctx
= __info
;
7991 perf_pmu_rotate_stop(ctx
->pmu
);
7994 list_for_each_entry_rcu(re
.event
, &ctx
->event_list
, event_entry
)
7995 __perf_remove_from_context(&re
);
7999 static void perf_event_exit_cpu_context(int cpu
)
8001 struct perf_event_context
*ctx
;
8005 idx
= srcu_read_lock(&pmus_srcu
);
8006 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
8007 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
8009 mutex_lock(&ctx
->mutex
);
8010 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
8011 mutex_unlock(&ctx
->mutex
);
8013 srcu_read_unlock(&pmus_srcu
, idx
);
8016 static void perf_event_exit_cpu(int cpu
)
8018 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
8020 perf_event_exit_cpu_context(cpu
);
8022 mutex_lock(&swhash
->hlist_mutex
);
8023 swhash
->online
= false;
8024 swevent_hlist_release(swhash
);
8025 mutex_unlock(&swhash
->hlist_mutex
);
8028 static inline void perf_event_exit_cpu(int cpu
) { }
8032 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
8036 for_each_online_cpu(cpu
)
8037 perf_event_exit_cpu(cpu
);
8043 * Run the perf reboot notifier at the very last possible moment so that
8044 * the generic watchdog code runs as long as possible.
8046 static struct notifier_block perf_reboot_notifier
= {
8047 .notifier_call
= perf_reboot
,
8048 .priority
= INT_MIN
,
8052 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
8054 unsigned int cpu
= (long)hcpu
;
8056 switch (action
& ~CPU_TASKS_FROZEN
) {
8058 case CPU_UP_PREPARE
:
8059 case CPU_DOWN_FAILED
:
8060 perf_event_init_cpu(cpu
);
8063 case CPU_UP_CANCELED
:
8064 case CPU_DOWN_PREPARE
:
8065 perf_event_exit_cpu(cpu
);
8074 void __init
perf_event_init(void)
8080 perf_event_init_all_cpus();
8081 init_srcu_struct(&pmus_srcu
);
8082 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
8083 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
8084 perf_pmu_register(&perf_task_clock
, NULL
, -1);
8086 perf_cpu_notifier(perf_cpu_notify
);
8087 register_reboot_notifier(&perf_reboot_notifier
);
8089 ret
= init_hw_breakpoint();
8090 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
8092 /* do not patch jump label more than once per second */
8093 jump_label_rate_limit(&perf_sched_events
, HZ
);
8096 * Build time assertion that we keep the data_head at the intended
8097 * location. IOW, validation we got the __reserved[] size right.
8099 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
8103 static int __init
perf_event_sysfs_init(void)
8108 mutex_lock(&pmus_lock
);
8110 ret
= bus_register(&pmu_bus
);
8114 list_for_each_entry(pmu
, &pmus
, entry
) {
8115 if (!pmu
->name
|| pmu
->type
< 0)
8118 ret
= pmu_dev_alloc(pmu
);
8119 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
8121 pmu_bus_running
= 1;
8125 mutex_unlock(&pmus_lock
);
8129 device_initcall(perf_event_sysfs_init
);
8131 #ifdef CONFIG_CGROUP_PERF
8132 static struct cgroup_subsys_state
*
8133 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
8135 struct perf_cgroup
*jc
;
8137 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
8139 return ERR_PTR(-ENOMEM
);
8141 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
8144 return ERR_PTR(-ENOMEM
);
8150 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
8152 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
8154 free_percpu(jc
->info
);
8158 static int __perf_cgroup_move(void *info
)
8160 struct task_struct
*task
= info
;
8161 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
8165 static void perf_cgroup_attach(struct cgroup_subsys_state
*css
,
8166 struct cgroup_taskset
*tset
)
8168 struct task_struct
*task
;
8170 cgroup_taskset_for_each(task
, tset
)
8171 task_function_call(task
, __perf_cgroup_move
, task
);
8174 static void perf_cgroup_exit(struct cgroup_subsys_state
*css
,
8175 struct cgroup_subsys_state
*old_css
,
8176 struct task_struct
*task
)
8179 * cgroup_exit() is called in the copy_process() failure path.
8180 * Ignore this case since the task hasn't ran yet, this avoids
8181 * trying to poke a half freed task state from generic code.
8183 if (!(task
->flags
& PF_EXITING
))
8186 task_function_call(task
, __perf_cgroup_move
, task
);
8189 struct cgroup_subsys perf_event_cgrp_subsys
= {
8190 .css_alloc
= perf_cgroup_css_alloc
,
8191 .css_free
= perf_cgroup_css_free
,
8192 .exit
= perf_cgroup_exit
,
8193 .attach
= perf_cgroup_attach
,
8195 #endif /* CONFIG_CGROUP_PERF */