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/cgroup.h>
38 #include <linux/perf_event.h>
39 #include <linux/trace_events.h>
40 #include <linux/hw_breakpoint.h>
41 #include <linux/mm_types.h>
42 #include <linux/module.h>
43 #include <linux/mman.h>
44 #include <linux/compat.h>
45 #include <linux/bpf.h>
46 #include <linux/filter.h>
50 #include <asm/irq_regs.h>
52 static struct workqueue_struct
*perf_wq
;
54 typedef int (*remote_function_f
)(void *);
56 struct remote_function_call
{
57 struct task_struct
*p
;
58 remote_function_f func
;
63 static void remote_function(void *data
)
65 struct remote_function_call
*tfc
= data
;
66 struct task_struct
*p
= tfc
->p
;
70 if (task_cpu(p
) != smp_processor_id() || !task_curr(p
))
74 tfc
->ret
= tfc
->func(tfc
->info
);
78 * task_function_call - call a function on the cpu on which a task runs
79 * @p: the task to evaluate
80 * @func: the function to be called
81 * @info: the function call argument
83 * Calls the function @func when the task is currently running. This might
84 * be on the current CPU, which just calls the function directly
86 * returns: @func return value, or
87 * -ESRCH - when the process isn't running
88 * -EAGAIN - when the process moved away
91 task_function_call(struct task_struct
*p
, remote_function_f func
, void *info
)
93 struct remote_function_call data
= {
97 .ret
= -ESRCH
, /* No such (running) process */
101 smp_call_function_single(task_cpu(p
), remote_function
, &data
, 1);
107 * cpu_function_call - call a function on the cpu
108 * @func: the function to be called
109 * @info: the function call argument
111 * Calls the function @func on the remote cpu.
113 * returns: @func return value or -ENXIO when the cpu is offline
115 static int cpu_function_call(int cpu
, remote_function_f func
, void *info
)
117 struct remote_function_call data
= {
121 .ret
= -ENXIO
, /* No such CPU */
124 smp_call_function_single(cpu
, remote_function
, &data
, 1);
129 #define EVENT_OWNER_KERNEL ((void *) -1)
131 static bool is_kernel_event(struct perf_event
*event
)
133 return event
->owner
== EVENT_OWNER_KERNEL
;
136 #define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
137 PERF_FLAG_FD_OUTPUT |\
138 PERF_FLAG_PID_CGROUP |\
139 PERF_FLAG_FD_CLOEXEC)
142 * branch priv levels that need permission checks
144 #define PERF_SAMPLE_BRANCH_PERM_PLM \
145 (PERF_SAMPLE_BRANCH_KERNEL |\
146 PERF_SAMPLE_BRANCH_HV)
149 EVENT_FLEXIBLE
= 0x1,
151 EVENT_ALL
= EVENT_FLEXIBLE
| EVENT_PINNED
,
155 * perf_sched_events : >0 events exist
156 * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu
158 struct static_key_deferred perf_sched_events __read_mostly
;
159 static DEFINE_PER_CPU(atomic_t
, perf_cgroup_events
);
160 static DEFINE_PER_CPU(int, perf_sched_cb_usages
);
162 static atomic_t nr_mmap_events __read_mostly
;
163 static atomic_t nr_comm_events __read_mostly
;
164 static atomic_t nr_task_events __read_mostly
;
165 static atomic_t nr_freq_events __read_mostly
;
166 static atomic_t nr_switch_events __read_mostly
;
168 static LIST_HEAD(pmus
);
169 static DEFINE_MUTEX(pmus_lock
);
170 static struct srcu_struct pmus_srcu
;
173 * perf event paranoia level:
174 * -1 - not paranoid at all
175 * 0 - disallow raw tracepoint access for unpriv
176 * 1 - disallow cpu events for unpriv
177 * 2 - disallow kernel profiling for unpriv
179 int sysctl_perf_event_paranoid __read_mostly
= 1;
181 /* Minimum for 512 kiB + 1 user control page */
182 int sysctl_perf_event_mlock __read_mostly
= 512 + (PAGE_SIZE
/ 1024); /* 'free' kiB per user */
185 * max perf event sample rate
187 #define DEFAULT_MAX_SAMPLE_RATE 100000
188 #define DEFAULT_SAMPLE_PERIOD_NS (NSEC_PER_SEC / DEFAULT_MAX_SAMPLE_RATE)
189 #define DEFAULT_CPU_TIME_MAX_PERCENT 25
191 int sysctl_perf_event_sample_rate __read_mostly
= DEFAULT_MAX_SAMPLE_RATE
;
193 static int max_samples_per_tick __read_mostly
= DIV_ROUND_UP(DEFAULT_MAX_SAMPLE_RATE
, HZ
);
194 static int perf_sample_period_ns __read_mostly
= DEFAULT_SAMPLE_PERIOD_NS
;
196 static int perf_sample_allowed_ns __read_mostly
=
197 DEFAULT_SAMPLE_PERIOD_NS
* DEFAULT_CPU_TIME_MAX_PERCENT
/ 100;
199 static void update_perf_cpu_limits(void)
201 u64 tmp
= perf_sample_period_ns
;
203 tmp
*= sysctl_perf_cpu_time_max_percent
;
205 ACCESS_ONCE(perf_sample_allowed_ns
) = tmp
;
208 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
);
210 int perf_proc_update_handler(struct ctl_table
*table
, int write
,
211 void __user
*buffer
, size_t *lenp
,
214 int ret
= proc_dointvec_minmax(table
, write
, buffer
, lenp
, ppos
);
219 max_samples_per_tick
= DIV_ROUND_UP(sysctl_perf_event_sample_rate
, HZ
);
220 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
221 update_perf_cpu_limits();
226 int sysctl_perf_cpu_time_max_percent __read_mostly
= DEFAULT_CPU_TIME_MAX_PERCENT
;
228 int perf_cpu_time_max_percent_handler(struct ctl_table
*table
, int write
,
229 void __user
*buffer
, size_t *lenp
,
232 int ret
= proc_dointvec(table
, write
, buffer
, lenp
, ppos
);
237 update_perf_cpu_limits();
243 * perf samples are done in some very critical code paths (NMIs).
244 * If they take too much CPU time, the system can lock up and not
245 * get any real work done. This will drop the sample rate when
246 * we detect that events are taking too long.
248 #define NR_ACCUMULATED_SAMPLES 128
249 static DEFINE_PER_CPU(u64
, running_sample_length
);
251 static void perf_duration_warn(struct irq_work
*w
)
253 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
254 u64 avg_local_sample_len
;
255 u64 local_samples_len
;
257 local_samples_len
= __this_cpu_read(running_sample_length
);
258 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
260 printk_ratelimited(KERN_WARNING
261 "perf interrupt took too long (%lld > %lld), lowering "
262 "kernel.perf_event_max_sample_rate to %d\n",
263 avg_local_sample_len
, allowed_ns
>> 1,
264 sysctl_perf_event_sample_rate
);
267 static DEFINE_IRQ_WORK(perf_duration_work
, perf_duration_warn
);
269 void perf_sample_event_took(u64 sample_len_ns
)
271 u64 allowed_ns
= ACCESS_ONCE(perf_sample_allowed_ns
);
272 u64 avg_local_sample_len
;
273 u64 local_samples_len
;
278 /* decay the counter by 1 average sample */
279 local_samples_len
= __this_cpu_read(running_sample_length
);
280 local_samples_len
-= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
281 local_samples_len
+= sample_len_ns
;
282 __this_cpu_write(running_sample_length
, local_samples_len
);
285 * note: this will be biased artifically low until we have
286 * seen NR_ACCUMULATED_SAMPLES. Doing it this way keeps us
287 * from having to maintain a count.
289 avg_local_sample_len
= local_samples_len
/NR_ACCUMULATED_SAMPLES
;
291 if (avg_local_sample_len
<= allowed_ns
)
294 if (max_samples_per_tick
<= 1)
297 max_samples_per_tick
= DIV_ROUND_UP(max_samples_per_tick
, 2);
298 sysctl_perf_event_sample_rate
= max_samples_per_tick
* HZ
;
299 perf_sample_period_ns
= NSEC_PER_SEC
/ sysctl_perf_event_sample_rate
;
301 update_perf_cpu_limits();
303 if (!irq_work_queue(&perf_duration_work
)) {
304 early_printk("perf interrupt took too long (%lld > %lld), lowering "
305 "kernel.perf_event_max_sample_rate to %d\n",
306 avg_local_sample_len
, allowed_ns
>> 1,
307 sysctl_perf_event_sample_rate
);
311 static atomic64_t perf_event_id
;
313 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
314 enum event_type_t event_type
);
316 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
317 enum event_type_t event_type
,
318 struct task_struct
*task
);
320 static void update_context_time(struct perf_event_context
*ctx
);
321 static u64
perf_event_time(struct perf_event
*event
);
323 void __weak
perf_event_print_debug(void) { }
325 extern __weak
const char *perf_pmu_name(void)
330 static inline u64
perf_clock(void)
332 return local_clock();
335 static inline u64
perf_event_clock(struct perf_event
*event
)
337 return event
->clock();
340 static inline struct perf_cpu_context
*
341 __get_cpu_context(struct perf_event_context
*ctx
)
343 return this_cpu_ptr(ctx
->pmu
->pmu_cpu_context
);
346 static void perf_ctx_lock(struct perf_cpu_context
*cpuctx
,
347 struct perf_event_context
*ctx
)
349 raw_spin_lock(&cpuctx
->ctx
.lock
);
351 raw_spin_lock(&ctx
->lock
);
354 static void perf_ctx_unlock(struct perf_cpu_context
*cpuctx
,
355 struct perf_event_context
*ctx
)
358 raw_spin_unlock(&ctx
->lock
);
359 raw_spin_unlock(&cpuctx
->ctx
.lock
);
362 #ifdef CONFIG_CGROUP_PERF
365 perf_cgroup_match(struct perf_event
*event
)
367 struct perf_event_context
*ctx
= event
->ctx
;
368 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
370 /* @event doesn't care about cgroup */
374 /* wants specific cgroup scope but @cpuctx isn't associated with any */
379 * Cgroup scoping is recursive. An event enabled for a cgroup is
380 * also enabled for all its descendant cgroups. If @cpuctx's
381 * cgroup is a descendant of @event's (the test covers identity
382 * case), it's a match.
384 return cgroup_is_descendant(cpuctx
->cgrp
->css
.cgroup
,
385 event
->cgrp
->css
.cgroup
);
388 static inline void perf_detach_cgroup(struct perf_event
*event
)
390 css_put(&event
->cgrp
->css
);
394 static inline int is_cgroup_event(struct perf_event
*event
)
396 return event
->cgrp
!= NULL
;
399 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
401 struct perf_cgroup_info
*t
;
403 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
407 static inline void __update_cgrp_time(struct perf_cgroup
*cgrp
)
409 struct perf_cgroup_info
*info
;
414 info
= this_cpu_ptr(cgrp
->info
);
416 info
->time
+= now
- info
->timestamp
;
417 info
->timestamp
= now
;
420 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
422 struct perf_cgroup
*cgrp_out
= cpuctx
->cgrp
;
424 __update_cgrp_time(cgrp_out
);
427 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
429 struct perf_cgroup
*cgrp
;
432 * ensure we access cgroup data only when needed and
433 * when we know the cgroup is pinned (css_get)
435 if (!is_cgroup_event(event
))
438 cgrp
= perf_cgroup_from_task(current
);
440 * Do not update time when cgroup is not active
442 if (cgrp
== event
->cgrp
)
443 __update_cgrp_time(event
->cgrp
);
447 perf_cgroup_set_timestamp(struct task_struct
*task
,
448 struct perf_event_context
*ctx
)
450 struct perf_cgroup
*cgrp
;
451 struct perf_cgroup_info
*info
;
454 * ctx->lock held by caller
455 * ensure we do not access cgroup data
456 * unless we have the cgroup pinned (css_get)
458 if (!task
|| !ctx
->nr_cgroups
)
461 cgrp
= perf_cgroup_from_task(task
);
462 info
= this_cpu_ptr(cgrp
->info
);
463 info
->timestamp
= ctx
->timestamp
;
466 #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */
467 #define PERF_CGROUP_SWIN 0x2 /* cgroup switch in events based on task */
470 * reschedule events based on the cgroup constraint of task.
472 * mode SWOUT : schedule out everything
473 * mode SWIN : schedule in based on cgroup for next
475 static void perf_cgroup_switch(struct task_struct
*task
, int mode
)
477 struct perf_cpu_context
*cpuctx
;
482 * disable interrupts to avoid geting nr_cgroup
483 * changes via __perf_event_disable(). Also
486 local_irq_save(flags
);
489 * we reschedule only in the presence of cgroup
490 * constrained events.
494 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
495 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
496 if (cpuctx
->unique_pmu
!= pmu
)
497 continue; /* ensure we process each cpuctx once */
500 * perf_cgroup_events says at least one
501 * context on this CPU has cgroup events.
503 * ctx->nr_cgroups reports the number of cgroup
504 * events for a context.
506 if (cpuctx
->ctx
.nr_cgroups
> 0) {
507 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
508 perf_pmu_disable(cpuctx
->ctx
.pmu
);
510 if (mode
& PERF_CGROUP_SWOUT
) {
511 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
513 * must not be done before ctxswout due
514 * to event_filter_match() in event_sched_out()
519 if (mode
& PERF_CGROUP_SWIN
) {
520 WARN_ON_ONCE(cpuctx
->cgrp
);
522 * set cgrp before ctxsw in to allow
523 * event_filter_match() to not have to pass
526 cpuctx
->cgrp
= perf_cgroup_from_task(task
);
527 cpu_ctx_sched_in(cpuctx
, EVENT_ALL
, task
);
529 perf_pmu_enable(cpuctx
->ctx
.pmu
);
530 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
536 local_irq_restore(flags
);
539 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
540 struct task_struct
*next
)
542 struct perf_cgroup
*cgrp1
;
543 struct perf_cgroup
*cgrp2
= NULL
;
546 * we come here when we know perf_cgroup_events > 0
548 cgrp1
= perf_cgroup_from_task(task
);
551 * next is NULL when called from perf_event_enable_on_exec()
552 * that will systematically cause a cgroup_switch()
555 cgrp2
= perf_cgroup_from_task(next
);
558 * only schedule out current cgroup events if we know
559 * that we are switching to a different cgroup. Otherwise,
560 * do no touch the cgroup events.
563 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
);
566 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
567 struct task_struct
*task
)
569 struct perf_cgroup
*cgrp1
;
570 struct perf_cgroup
*cgrp2
= NULL
;
573 * we come here when we know perf_cgroup_events > 0
575 cgrp1
= perf_cgroup_from_task(task
);
577 /* prev can never be NULL */
578 cgrp2
= perf_cgroup_from_task(prev
);
581 * only need to schedule in cgroup events if we are changing
582 * cgroup during ctxsw. Cgroup events were not scheduled
583 * out of ctxsw out if that was not the case.
586 perf_cgroup_switch(task
, PERF_CGROUP_SWIN
);
589 static inline int perf_cgroup_connect(int fd
, struct perf_event
*event
,
590 struct perf_event_attr
*attr
,
591 struct perf_event
*group_leader
)
593 struct perf_cgroup
*cgrp
;
594 struct cgroup_subsys_state
*css
;
595 struct fd f
= fdget(fd
);
601 css
= css_tryget_online_from_dir(f
.file
->f_path
.dentry
,
602 &perf_event_cgrp_subsys
);
608 cgrp
= container_of(css
, struct perf_cgroup
, css
);
612 * all events in a group must monitor
613 * the same cgroup because a task belongs
614 * to only one perf cgroup at a time
616 if (group_leader
&& group_leader
->cgrp
!= cgrp
) {
617 perf_detach_cgroup(event
);
626 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
628 struct perf_cgroup_info
*t
;
629 t
= per_cpu_ptr(event
->cgrp
->info
, event
->cpu
);
630 event
->shadow_ctx_time
= now
- t
->timestamp
;
634 perf_cgroup_defer_enabled(struct perf_event
*event
)
637 * when the current task's perf cgroup does not match
638 * the event's, we need to remember to call the
639 * perf_mark_enable() function the first time a task with
640 * a matching perf cgroup is scheduled in.
642 if (is_cgroup_event(event
) && !perf_cgroup_match(event
))
643 event
->cgrp_defer_enabled
= 1;
647 perf_cgroup_mark_enabled(struct perf_event
*event
,
648 struct perf_event_context
*ctx
)
650 struct perf_event
*sub
;
651 u64 tstamp
= perf_event_time(event
);
653 if (!event
->cgrp_defer_enabled
)
656 event
->cgrp_defer_enabled
= 0;
658 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
659 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
660 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
) {
661 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
662 sub
->cgrp_defer_enabled
= 0;
666 #else /* !CONFIG_CGROUP_PERF */
669 perf_cgroup_match(struct perf_event
*event
)
674 static inline void perf_detach_cgroup(struct perf_event
*event
)
677 static inline int is_cgroup_event(struct perf_event
*event
)
682 static inline u64
perf_cgroup_event_cgrp_time(struct perf_event
*event
)
687 static inline void update_cgrp_time_from_event(struct perf_event
*event
)
691 static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context
*cpuctx
)
695 static inline void perf_cgroup_sched_out(struct task_struct
*task
,
696 struct task_struct
*next
)
700 static inline void perf_cgroup_sched_in(struct task_struct
*prev
,
701 struct task_struct
*task
)
705 static inline int perf_cgroup_connect(pid_t pid
, struct perf_event
*event
,
706 struct perf_event_attr
*attr
,
707 struct perf_event
*group_leader
)
713 perf_cgroup_set_timestamp(struct task_struct
*task
,
714 struct perf_event_context
*ctx
)
719 perf_cgroup_switch(struct task_struct
*task
, struct task_struct
*next
)
724 perf_cgroup_set_shadow_time(struct perf_event
*event
, u64 now
)
728 static inline u64
perf_cgroup_event_time(struct perf_event
*event
)
734 perf_cgroup_defer_enabled(struct perf_event
*event
)
739 perf_cgroup_mark_enabled(struct perf_event
*event
,
740 struct perf_event_context
*ctx
)
746 * set default to be dependent on timer tick just
749 #define PERF_CPU_HRTIMER (1000 / HZ)
751 * function must be called with interrupts disbled
753 static enum hrtimer_restart
perf_mux_hrtimer_handler(struct hrtimer
*hr
)
755 struct perf_cpu_context
*cpuctx
;
758 WARN_ON(!irqs_disabled());
760 cpuctx
= container_of(hr
, struct perf_cpu_context
, hrtimer
);
761 rotations
= perf_rotate_context(cpuctx
);
763 raw_spin_lock(&cpuctx
->hrtimer_lock
);
765 hrtimer_forward_now(hr
, cpuctx
->hrtimer_interval
);
767 cpuctx
->hrtimer_active
= 0;
768 raw_spin_unlock(&cpuctx
->hrtimer_lock
);
770 return rotations
? HRTIMER_RESTART
: HRTIMER_NORESTART
;
773 static void __perf_mux_hrtimer_init(struct perf_cpu_context
*cpuctx
, int cpu
)
775 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
776 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
779 /* no multiplexing needed for SW PMU */
780 if (pmu
->task_ctx_nr
== perf_sw_context
)
784 * check default is sane, if not set then force to
785 * default interval (1/tick)
787 interval
= pmu
->hrtimer_interval_ms
;
789 interval
= pmu
->hrtimer_interval_ms
= PERF_CPU_HRTIMER
;
791 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* interval
);
793 raw_spin_lock_init(&cpuctx
->hrtimer_lock
);
794 hrtimer_init(timer
, CLOCK_MONOTONIC
, HRTIMER_MODE_ABS_PINNED
);
795 timer
->function
= perf_mux_hrtimer_handler
;
798 static int perf_mux_hrtimer_restart(struct perf_cpu_context
*cpuctx
)
800 struct hrtimer
*timer
= &cpuctx
->hrtimer
;
801 struct pmu
*pmu
= cpuctx
->ctx
.pmu
;
805 if (pmu
->task_ctx_nr
== perf_sw_context
)
808 raw_spin_lock_irqsave(&cpuctx
->hrtimer_lock
, flags
);
809 if (!cpuctx
->hrtimer_active
) {
810 cpuctx
->hrtimer_active
= 1;
811 hrtimer_forward_now(timer
, cpuctx
->hrtimer_interval
);
812 hrtimer_start_expires(timer
, HRTIMER_MODE_ABS_PINNED
);
814 raw_spin_unlock_irqrestore(&cpuctx
->hrtimer_lock
, flags
);
819 void perf_pmu_disable(struct pmu
*pmu
)
821 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
823 pmu
->pmu_disable(pmu
);
826 void perf_pmu_enable(struct pmu
*pmu
)
828 int *count
= this_cpu_ptr(pmu
->pmu_disable_count
);
830 pmu
->pmu_enable(pmu
);
833 static DEFINE_PER_CPU(struct list_head
, active_ctx_list
);
836 * perf_event_ctx_activate(), perf_event_ctx_deactivate(), and
837 * perf_event_task_tick() are fully serialized because they're strictly cpu
838 * affine and perf_event_ctx{activate,deactivate} are called with IRQs
839 * disabled, while perf_event_task_tick is called from IRQ context.
841 static void perf_event_ctx_activate(struct perf_event_context
*ctx
)
843 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
845 WARN_ON(!irqs_disabled());
847 WARN_ON(!list_empty(&ctx
->active_ctx_list
));
849 list_add(&ctx
->active_ctx_list
, head
);
852 static void perf_event_ctx_deactivate(struct perf_event_context
*ctx
)
854 WARN_ON(!irqs_disabled());
856 WARN_ON(list_empty(&ctx
->active_ctx_list
));
858 list_del_init(&ctx
->active_ctx_list
);
861 static void get_ctx(struct perf_event_context
*ctx
)
863 WARN_ON(!atomic_inc_not_zero(&ctx
->refcount
));
866 static void free_ctx(struct rcu_head
*head
)
868 struct perf_event_context
*ctx
;
870 ctx
= container_of(head
, struct perf_event_context
, rcu_head
);
871 kfree(ctx
->task_ctx_data
);
875 static void put_ctx(struct perf_event_context
*ctx
)
877 if (atomic_dec_and_test(&ctx
->refcount
)) {
879 put_ctx(ctx
->parent_ctx
);
881 put_task_struct(ctx
->task
);
882 call_rcu(&ctx
->rcu_head
, free_ctx
);
887 * Because of perf_event::ctx migration in sys_perf_event_open::move_group and
888 * perf_pmu_migrate_context() we need some magic.
890 * Those places that change perf_event::ctx will hold both
891 * perf_event_ctx::mutex of the 'old' and 'new' ctx value.
893 * Lock ordering is by mutex address. There are two other sites where
894 * perf_event_context::mutex nests and those are:
896 * - perf_event_exit_task_context() [ child , 0 ]
897 * __perf_event_exit_task()
899 * put_event() [ parent, 1 ]
901 * - perf_event_init_context() [ parent, 0 ]
902 * inherit_task_group()
907 * perf_try_init_event() [ child , 1 ]
909 * While it appears there is an obvious deadlock here -- the parent and child
910 * nesting levels are inverted between the two. This is in fact safe because
911 * life-time rules separate them. That is an exiting task cannot fork, and a
912 * spawning task cannot (yet) exit.
914 * But remember that that these are parent<->child context relations, and
915 * migration does not affect children, therefore these two orderings should not
918 * The change in perf_event::ctx does not affect children (as claimed above)
919 * because the sys_perf_event_open() case will install a new event and break
920 * the ctx parent<->child relation, and perf_pmu_migrate_context() is only
921 * concerned with cpuctx and that doesn't have children.
923 * The places that change perf_event::ctx will issue:
925 * perf_remove_from_context();
927 * perf_install_in_context();
929 * to affect the change. The remove_from_context() + synchronize_rcu() should
930 * quiesce the event, after which we can install it in the new location. This
931 * means that only external vectors (perf_fops, prctl) can perturb the event
932 * while in transit. Therefore all such accessors should also acquire
933 * perf_event_context::mutex to serialize against this.
935 * However; because event->ctx can change while we're waiting to acquire
936 * ctx->mutex we must be careful and use the below perf_event_ctx_lock()
940 * task_struct::perf_event_mutex
941 * perf_event_context::mutex
942 * perf_event_context::lock
943 * perf_event::child_mutex;
944 * perf_event::mmap_mutex
947 static struct perf_event_context
*
948 perf_event_ctx_lock_nested(struct perf_event
*event
, int nesting
)
950 struct perf_event_context
*ctx
;
954 ctx
= ACCESS_ONCE(event
->ctx
);
955 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
961 mutex_lock_nested(&ctx
->mutex
, nesting
);
962 if (event
->ctx
!= ctx
) {
963 mutex_unlock(&ctx
->mutex
);
971 static inline struct perf_event_context
*
972 perf_event_ctx_lock(struct perf_event
*event
)
974 return perf_event_ctx_lock_nested(event
, 0);
977 static void perf_event_ctx_unlock(struct perf_event
*event
,
978 struct perf_event_context
*ctx
)
980 mutex_unlock(&ctx
->mutex
);
985 * This must be done under the ctx->lock, such as to serialize against
986 * context_equiv(), therefore we cannot call put_ctx() since that might end up
987 * calling scheduler related locks and ctx->lock nests inside those.
989 static __must_check
struct perf_event_context
*
990 unclone_ctx(struct perf_event_context
*ctx
)
992 struct perf_event_context
*parent_ctx
= ctx
->parent_ctx
;
994 lockdep_assert_held(&ctx
->lock
);
997 ctx
->parent_ctx
= NULL
;
1003 static u32
perf_event_pid(struct perf_event
*event
, struct task_struct
*p
)
1006 * only top level events have the pid namespace they were created in
1009 event
= event
->parent
;
1011 return task_tgid_nr_ns(p
, event
->ns
);
1014 static u32
perf_event_tid(struct perf_event
*event
, struct task_struct
*p
)
1017 * only top level events have the pid namespace they were created in
1020 event
= event
->parent
;
1022 return task_pid_nr_ns(p
, event
->ns
);
1026 * If we inherit events we want to return the parent event id
1029 static u64
primary_event_id(struct perf_event
*event
)
1034 id
= event
->parent
->id
;
1040 * Get the perf_event_context for a task and lock it.
1041 * This has to cope with with the fact that until it is locked,
1042 * the context could get moved to another task.
1044 static struct perf_event_context
*
1045 perf_lock_task_context(struct task_struct
*task
, int ctxn
, unsigned long *flags
)
1047 struct perf_event_context
*ctx
;
1051 * One of the few rules of preemptible RCU is that one cannot do
1052 * rcu_read_unlock() while holding a scheduler (or nested) lock when
1053 * part of the read side critical section was preemptible -- see
1054 * rcu_read_unlock_special().
1056 * Since ctx->lock nests under rq->lock we must ensure the entire read
1057 * side critical section is non-preemptible.
1061 ctx
= rcu_dereference(task
->perf_event_ctxp
[ctxn
]);
1064 * If this context is a clone of another, it might
1065 * get swapped for another underneath us by
1066 * perf_event_task_sched_out, though the
1067 * rcu_read_lock() protects us from any context
1068 * getting freed. Lock the context and check if it
1069 * got swapped before we could get the lock, and retry
1070 * if so. If we locked the right context, then it
1071 * can't get swapped on us any more.
1073 raw_spin_lock_irqsave(&ctx
->lock
, *flags
);
1074 if (ctx
!= rcu_dereference(task
->perf_event_ctxp
[ctxn
])) {
1075 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
1081 if (!atomic_inc_not_zero(&ctx
->refcount
)) {
1082 raw_spin_unlock_irqrestore(&ctx
->lock
, *flags
);
1092 * Get the context for a task and increment its pin_count so it
1093 * can't get swapped to another task. This also increments its
1094 * reference count so that the context can't get freed.
1096 static struct perf_event_context
*
1097 perf_pin_task_context(struct task_struct
*task
, int ctxn
)
1099 struct perf_event_context
*ctx
;
1100 unsigned long flags
;
1102 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
1105 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1110 static void perf_unpin_context(struct perf_event_context
*ctx
)
1112 unsigned long flags
;
1114 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
1116 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
1120 * Update the record of the current time in a context.
1122 static void update_context_time(struct perf_event_context
*ctx
)
1124 u64 now
= perf_clock();
1126 ctx
->time
+= now
- ctx
->timestamp
;
1127 ctx
->timestamp
= now
;
1130 static u64
perf_event_time(struct perf_event
*event
)
1132 struct perf_event_context
*ctx
= event
->ctx
;
1134 if (is_cgroup_event(event
))
1135 return perf_cgroup_event_time(event
);
1137 return ctx
? ctx
->time
: 0;
1141 * Update the total_time_enabled and total_time_running fields for a event.
1142 * The caller of this function needs to hold the ctx->lock.
1144 static void update_event_times(struct perf_event
*event
)
1146 struct perf_event_context
*ctx
= event
->ctx
;
1149 if (event
->state
< PERF_EVENT_STATE_INACTIVE
||
1150 event
->group_leader
->state
< PERF_EVENT_STATE_INACTIVE
)
1153 * in cgroup mode, time_enabled represents
1154 * the time the event was enabled AND active
1155 * tasks were in the monitored cgroup. This is
1156 * independent of the activity of the context as
1157 * there may be a mix of cgroup and non-cgroup events.
1159 * That is why we treat cgroup events differently
1162 if (is_cgroup_event(event
))
1163 run_end
= perf_cgroup_event_time(event
);
1164 else if (ctx
->is_active
)
1165 run_end
= ctx
->time
;
1167 run_end
= event
->tstamp_stopped
;
1169 event
->total_time_enabled
= run_end
- event
->tstamp_enabled
;
1171 if (event
->state
== PERF_EVENT_STATE_INACTIVE
)
1172 run_end
= event
->tstamp_stopped
;
1174 run_end
= perf_event_time(event
);
1176 event
->total_time_running
= run_end
- event
->tstamp_running
;
1181 * Update total_time_enabled and total_time_running for all events in a group.
1183 static void update_group_times(struct perf_event
*leader
)
1185 struct perf_event
*event
;
1187 update_event_times(leader
);
1188 list_for_each_entry(event
, &leader
->sibling_list
, group_entry
)
1189 update_event_times(event
);
1192 static struct list_head
*
1193 ctx_group_list(struct perf_event
*event
, struct perf_event_context
*ctx
)
1195 if (event
->attr
.pinned
)
1196 return &ctx
->pinned_groups
;
1198 return &ctx
->flexible_groups
;
1202 * Add a event from the lists for its context.
1203 * Must be called with ctx->mutex and ctx->lock held.
1206 list_add_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1208 WARN_ON_ONCE(event
->attach_state
& PERF_ATTACH_CONTEXT
);
1209 event
->attach_state
|= PERF_ATTACH_CONTEXT
;
1212 * If we're a stand alone event or group leader, we go to the context
1213 * list, group events are kept attached to the group so that
1214 * perf_group_detach can, at all times, locate all siblings.
1216 if (event
->group_leader
== event
) {
1217 struct list_head
*list
;
1219 if (is_software_event(event
))
1220 event
->group_flags
|= PERF_GROUP_SOFTWARE
;
1222 list
= ctx_group_list(event
, ctx
);
1223 list_add_tail(&event
->group_entry
, list
);
1226 if (is_cgroup_event(event
))
1229 list_add_rcu(&event
->event_entry
, &ctx
->event_list
);
1231 if (event
->attr
.inherit_stat
)
1238 * Initialize event state based on the perf_event_attr::disabled.
1240 static inline void perf_event__state_init(struct perf_event
*event
)
1242 event
->state
= event
->attr
.disabled
? PERF_EVENT_STATE_OFF
:
1243 PERF_EVENT_STATE_INACTIVE
;
1246 static void __perf_event_read_size(struct perf_event
*event
, int nr_siblings
)
1248 int entry
= sizeof(u64
); /* value */
1252 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
1253 size
+= sizeof(u64
);
1255 if (event
->attr
.read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
1256 size
+= sizeof(u64
);
1258 if (event
->attr
.read_format
& PERF_FORMAT_ID
)
1259 entry
+= sizeof(u64
);
1261 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
) {
1263 size
+= sizeof(u64
);
1267 event
->read_size
= size
;
1270 static void __perf_event_header_size(struct perf_event
*event
, u64 sample_type
)
1272 struct perf_sample_data
*data
;
1275 if (sample_type
& PERF_SAMPLE_IP
)
1276 size
+= sizeof(data
->ip
);
1278 if (sample_type
& PERF_SAMPLE_ADDR
)
1279 size
+= sizeof(data
->addr
);
1281 if (sample_type
& PERF_SAMPLE_PERIOD
)
1282 size
+= sizeof(data
->period
);
1284 if (sample_type
& PERF_SAMPLE_WEIGHT
)
1285 size
+= sizeof(data
->weight
);
1287 if (sample_type
& PERF_SAMPLE_READ
)
1288 size
+= event
->read_size
;
1290 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
1291 size
+= sizeof(data
->data_src
.val
);
1293 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
1294 size
+= sizeof(data
->txn
);
1296 event
->header_size
= size
;
1300 * Called at perf_event creation and when events are attached/detached from a
1303 static void perf_event__header_size(struct perf_event
*event
)
1305 __perf_event_read_size(event
,
1306 event
->group_leader
->nr_siblings
);
1307 __perf_event_header_size(event
, event
->attr
.sample_type
);
1310 static void perf_event__id_header_size(struct perf_event
*event
)
1312 struct perf_sample_data
*data
;
1313 u64 sample_type
= event
->attr
.sample_type
;
1316 if (sample_type
& PERF_SAMPLE_TID
)
1317 size
+= sizeof(data
->tid_entry
);
1319 if (sample_type
& PERF_SAMPLE_TIME
)
1320 size
+= sizeof(data
->time
);
1322 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
1323 size
+= sizeof(data
->id
);
1325 if (sample_type
& PERF_SAMPLE_ID
)
1326 size
+= sizeof(data
->id
);
1328 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
1329 size
+= sizeof(data
->stream_id
);
1331 if (sample_type
& PERF_SAMPLE_CPU
)
1332 size
+= sizeof(data
->cpu_entry
);
1334 event
->id_header_size
= size
;
1337 static bool perf_event_validate_size(struct perf_event
*event
)
1340 * The values computed here will be over-written when we actually
1343 __perf_event_read_size(event
, event
->group_leader
->nr_siblings
+ 1);
1344 __perf_event_header_size(event
, event
->attr
.sample_type
& ~PERF_SAMPLE_READ
);
1345 perf_event__id_header_size(event
);
1348 * Sum the lot; should not exceed the 64k limit we have on records.
1349 * Conservative limit to allow for callchains and other variable fields.
1351 if (event
->read_size
+ event
->header_size
+
1352 event
->id_header_size
+ sizeof(struct perf_event_header
) >= 16*1024)
1358 static void perf_group_attach(struct perf_event
*event
)
1360 struct perf_event
*group_leader
= event
->group_leader
, *pos
;
1363 * We can have double attach due to group movement in perf_event_open.
1365 if (event
->attach_state
& PERF_ATTACH_GROUP
)
1368 event
->attach_state
|= PERF_ATTACH_GROUP
;
1370 if (group_leader
== event
)
1373 WARN_ON_ONCE(group_leader
->ctx
!= event
->ctx
);
1375 if (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
&&
1376 !is_software_event(event
))
1377 group_leader
->group_flags
&= ~PERF_GROUP_SOFTWARE
;
1379 list_add_tail(&event
->group_entry
, &group_leader
->sibling_list
);
1380 group_leader
->nr_siblings
++;
1382 perf_event__header_size(group_leader
);
1384 list_for_each_entry(pos
, &group_leader
->sibling_list
, group_entry
)
1385 perf_event__header_size(pos
);
1389 * Remove a event from the lists for its context.
1390 * Must be called with ctx->mutex and ctx->lock held.
1393 list_del_event(struct perf_event
*event
, struct perf_event_context
*ctx
)
1395 struct perf_cpu_context
*cpuctx
;
1397 WARN_ON_ONCE(event
->ctx
!= ctx
);
1398 lockdep_assert_held(&ctx
->lock
);
1401 * We can have double detach due to exit/hot-unplug + close.
1403 if (!(event
->attach_state
& PERF_ATTACH_CONTEXT
))
1406 event
->attach_state
&= ~PERF_ATTACH_CONTEXT
;
1408 if (is_cgroup_event(event
)) {
1410 cpuctx
= __get_cpu_context(ctx
);
1412 * if there are no more cgroup events
1413 * then cler cgrp to avoid stale pointer
1414 * in update_cgrp_time_from_cpuctx()
1416 if (!ctx
->nr_cgroups
)
1417 cpuctx
->cgrp
= NULL
;
1421 if (event
->attr
.inherit_stat
)
1424 list_del_rcu(&event
->event_entry
);
1426 if (event
->group_leader
== event
)
1427 list_del_init(&event
->group_entry
);
1429 update_group_times(event
);
1432 * If event was in error state, then keep it
1433 * that way, otherwise bogus counts will be
1434 * returned on read(). The only way to get out
1435 * of error state is by explicit re-enabling
1438 if (event
->state
> PERF_EVENT_STATE_OFF
)
1439 event
->state
= PERF_EVENT_STATE_OFF
;
1444 static void perf_group_detach(struct perf_event
*event
)
1446 struct perf_event
*sibling
, *tmp
;
1447 struct list_head
*list
= NULL
;
1450 * We can have double detach due to exit/hot-unplug + close.
1452 if (!(event
->attach_state
& PERF_ATTACH_GROUP
))
1455 event
->attach_state
&= ~PERF_ATTACH_GROUP
;
1458 * If this is a sibling, remove it from its group.
1460 if (event
->group_leader
!= event
) {
1461 list_del_init(&event
->group_entry
);
1462 event
->group_leader
->nr_siblings
--;
1466 if (!list_empty(&event
->group_entry
))
1467 list
= &event
->group_entry
;
1470 * If this was a group event with sibling events then
1471 * upgrade the siblings to singleton events by adding them
1472 * to whatever list we are on.
1474 list_for_each_entry_safe(sibling
, tmp
, &event
->sibling_list
, group_entry
) {
1476 list_move_tail(&sibling
->group_entry
, list
);
1477 sibling
->group_leader
= sibling
;
1479 /* Inherit group flags from the previous leader */
1480 sibling
->group_flags
= event
->group_flags
;
1482 WARN_ON_ONCE(sibling
->ctx
!= event
->ctx
);
1486 perf_event__header_size(event
->group_leader
);
1488 list_for_each_entry(tmp
, &event
->group_leader
->sibling_list
, group_entry
)
1489 perf_event__header_size(tmp
);
1493 * User event without the task.
1495 static bool is_orphaned_event(struct perf_event
*event
)
1497 return event
&& !is_kernel_event(event
) && !event
->owner
;
1501 * Event has a parent but parent's task finished and it's
1502 * alive only because of children holding refference.
1504 static bool is_orphaned_child(struct perf_event
*event
)
1506 return is_orphaned_event(event
->parent
);
1509 static void orphans_remove_work(struct work_struct
*work
);
1511 static void schedule_orphans_remove(struct perf_event_context
*ctx
)
1513 if (!ctx
->task
|| ctx
->orphans_remove_sched
|| !perf_wq
)
1516 if (queue_delayed_work(perf_wq
, &ctx
->orphans_remove
, 1)) {
1518 ctx
->orphans_remove_sched
= true;
1522 static int __init
perf_workqueue_init(void)
1524 perf_wq
= create_singlethread_workqueue("perf");
1525 WARN(!perf_wq
, "failed to create perf workqueue\n");
1526 return perf_wq
? 0 : -1;
1529 core_initcall(perf_workqueue_init
);
1531 static inline int pmu_filter_match(struct perf_event
*event
)
1533 struct pmu
*pmu
= event
->pmu
;
1534 return pmu
->filter_match
? pmu
->filter_match(event
) : 1;
1538 event_filter_match(struct perf_event
*event
)
1540 return (event
->cpu
== -1 || event
->cpu
== smp_processor_id())
1541 && perf_cgroup_match(event
) && pmu_filter_match(event
);
1545 event_sched_out(struct perf_event
*event
,
1546 struct perf_cpu_context
*cpuctx
,
1547 struct perf_event_context
*ctx
)
1549 u64 tstamp
= perf_event_time(event
);
1552 WARN_ON_ONCE(event
->ctx
!= ctx
);
1553 lockdep_assert_held(&ctx
->lock
);
1556 * An event which could not be activated because of
1557 * filter mismatch still needs to have its timings
1558 * maintained, otherwise bogus information is return
1559 * via read() for time_enabled, time_running:
1561 if (event
->state
== PERF_EVENT_STATE_INACTIVE
1562 && !event_filter_match(event
)) {
1563 delta
= tstamp
- event
->tstamp_stopped
;
1564 event
->tstamp_running
+= delta
;
1565 event
->tstamp_stopped
= tstamp
;
1568 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
1571 perf_pmu_disable(event
->pmu
);
1573 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1574 if (event
->pending_disable
) {
1575 event
->pending_disable
= 0;
1576 event
->state
= PERF_EVENT_STATE_OFF
;
1578 event
->tstamp_stopped
= tstamp
;
1579 event
->pmu
->del(event
, 0);
1582 if (!is_software_event(event
))
1583 cpuctx
->active_oncpu
--;
1584 if (!--ctx
->nr_active
)
1585 perf_event_ctx_deactivate(ctx
);
1586 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1588 if (event
->attr
.exclusive
|| !cpuctx
->active_oncpu
)
1589 cpuctx
->exclusive
= 0;
1591 if (is_orphaned_child(event
))
1592 schedule_orphans_remove(ctx
);
1594 perf_pmu_enable(event
->pmu
);
1598 group_sched_out(struct perf_event
*group_event
,
1599 struct perf_cpu_context
*cpuctx
,
1600 struct perf_event_context
*ctx
)
1602 struct perf_event
*event
;
1603 int state
= group_event
->state
;
1605 event_sched_out(group_event
, cpuctx
, ctx
);
1608 * Schedule out siblings (if any):
1610 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
)
1611 event_sched_out(event
, cpuctx
, ctx
);
1613 if (state
== PERF_EVENT_STATE_ACTIVE
&& group_event
->attr
.exclusive
)
1614 cpuctx
->exclusive
= 0;
1617 struct remove_event
{
1618 struct perf_event
*event
;
1623 * Cross CPU call to remove a performance event
1625 * We disable the event on the hardware level first. After that we
1626 * remove it from the context list.
1628 static int __perf_remove_from_context(void *info
)
1630 struct remove_event
*re
= info
;
1631 struct perf_event
*event
= re
->event
;
1632 struct perf_event_context
*ctx
= event
->ctx
;
1633 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1635 raw_spin_lock(&ctx
->lock
);
1636 event_sched_out(event
, cpuctx
, ctx
);
1637 if (re
->detach_group
)
1638 perf_group_detach(event
);
1639 list_del_event(event
, ctx
);
1640 if (!ctx
->nr_events
&& cpuctx
->task_ctx
== ctx
) {
1642 cpuctx
->task_ctx
= NULL
;
1644 raw_spin_unlock(&ctx
->lock
);
1651 * Remove the event from a task's (or a CPU's) list of events.
1653 * CPU events are removed with a smp call. For task events we only
1654 * call when the task is on a CPU.
1656 * If event->ctx is a cloned context, callers must make sure that
1657 * every task struct that event->ctx->task could possibly point to
1658 * remains valid. This is OK when called from perf_release since
1659 * that only calls us on the top-level context, which can't be a clone.
1660 * When called from perf_event_exit_task, it's OK because the
1661 * context has been detached from its task.
1663 static void perf_remove_from_context(struct perf_event
*event
, bool detach_group
)
1665 struct perf_event_context
*ctx
= event
->ctx
;
1666 struct task_struct
*task
= ctx
->task
;
1667 struct remove_event re
= {
1669 .detach_group
= detach_group
,
1672 lockdep_assert_held(&ctx
->mutex
);
1676 * Per cpu events are removed via an smp call. The removal can
1677 * fail if the CPU is currently offline, but in that case we
1678 * already called __perf_remove_from_context from
1679 * perf_event_exit_cpu.
1681 cpu_function_call(event
->cpu
, __perf_remove_from_context
, &re
);
1686 if (!task_function_call(task
, __perf_remove_from_context
, &re
))
1689 raw_spin_lock_irq(&ctx
->lock
);
1691 * If we failed to find a running task, but find the context active now
1692 * that we've acquired the ctx->lock, retry.
1694 if (ctx
->is_active
) {
1695 raw_spin_unlock_irq(&ctx
->lock
);
1697 * Reload the task pointer, it might have been changed by
1698 * a concurrent perf_event_context_sched_out().
1705 * Since the task isn't running, its safe to remove the event, us
1706 * holding the ctx->lock ensures the task won't get scheduled in.
1709 perf_group_detach(event
);
1710 list_del_event(event
, ctx
);
1711 raw_spin_unlock_irq(&ctx
->lock
);
1715 * Cross CPU call to disable a performance event
1717 int __perf_event_disable(void *info
)
1719 struct perf_event
*event
= info
;
1720 struct perf_event_context
*ctx
= event
->ctx
;
1721 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
1724 * If this is a per-task event, need to check whether this
1725 * event's task is the current task on this cpu.
1727 * Can trigger due to concurrent perf_event_context_sched_out()
1728 * flipping contexts around.
1730 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
1733 raw_spin_lock(&ctx
->lock
);
1736 * If the event is on, turn it off.
1737 * If it is in error state, leave it in error state.
1739 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
) {
1740 update_context_time(ctx
);
1741 update_cgrp_time_from_event(event
);
1742 update_group_times(event
);
1743 if (event
== event
->group_leader
)
1744 group_sched_out(event
, cpuctx
, ctx
);
1746 event_sched_out(event
, cpuctx
, ctx
);
1747 event
->state
= PERF_EVENT_STATE_OFF
;
1750 raw_spin_unlock(&ctx
->lock
);
1758 * If event->ctx is a cloned context, callers must make sure that
1759 * every task struct that event->ctx->task could possibly point to
1760 * remains valid. This condition is satisifed when called through
1761 * perf_event_for_each_child or perf_event_for_each because they
1762 * hold the top-level event's child_mutex, so any descendant that
1763 * goes to exit will block in sync_child_event.
1764 * When called from perf_pending_event it's OK because event->ctx
1765 * is the current context on this CPU and preemption is disabled,
1766 * hence we can't get into perf_event_task_sched_out for this context.
1768 static void _perf_event_disable(struct perf_event
*event
)
1770 struct perf_event_context
*ctx
= event
->ctx
;
1771 struct task_struct
*task
= ctx
->task
;
1775 * Disable the event on the cpu that it's on
1777 cpu_function_call(event
->cpu
, __perf_event_disable
, event
);
1782 if (!task_function_call(task
, __perf_event_disable
, event
))
1785 raw_spin_lock_irq(&ctx
->lock
);
1787 * If the event is still active, we need to retry the cross-call.
1789 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
1790 raw_spin_unlock_irq(&ctx
->lock
);
1792 * Reload the task pointer, it might have been changed by
1793 * a concurrent perf_event_context_sched_out().
1800 * Since we have the lock this context can't be scheduled
1801 * in, so we can change the state safely.
1803 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
1804 update_group_times(event
);
1805 event
->state
= PERF_EVENT_STATE_OFF
;
1807 raw_spin_unlock_irq(&ctx
->lock
);
1811 * Strictly speaking kernel users cannot create groups and therefore this
1812 * interface does not need the perf_event_ctx_lock() magic.
1814 void perf_event_disable(struct perf_event
*event
)
1816 struct perf_event_context
*ctx
;
1818 ctx
= perf_event_ctx_lock(event
);
1819 _perf_event_disable(event
);
1820 perf_event_ctx_unlock(event
, ctx
);
1822 EXPORT_SYMBOL_GPL(perf_event_disable
);
1824 static void perf_set_shadow_time(struct perf_event
*event
,
1825 struct perf_event_context
*ctx
,
1829 * use the correct time source for the time snapshot
1831 * We could get by without this by leveraging the
1832 * fact that to get to this function, the caller
1833 * has most likely already called update_context_time()
1834 * and update_cgrp_time_xx() and thus both timestamp
1835 * are identical (or very close). Given that tstamp is,
1836 * already adjusted for cgroup, we could say that:
1837 * tstamp - ctx->timestamp
1839 * tstamp - cgrp->timestamp.
1841 * Then, in perf_output_read(), the calculation would
1842 * work with no changes because:
1843 * - event is guaranteed scheduled in
1844 * - no scheduled out in between
1845 * - thus the timestamp would be the same
1847 * But this is a bit hairy.
1849 * So instead, we have an explicit cgroup call to remain
1850 * within the time time source all along. We believe it
1851 * is cleaner and simpler to understand.
1853 if (is_cgroup_event(event
))
1854 perf_cgroup_set_shadow_time(event
, tstamp
);
1856 event
->shadow_ctx_time
= tstamp
- ctx
->timestamp
;
1859 #define MAX_INTERRUPTS (~0ULL)
1861 static void perf_log_throttle(struct perf_event
*event
, int enable
);
1862 static void perf_log_itrace_start(struct perf_event
*event
);
1865 event_sched_in(struct perf_event
*event
,
1866 struct perf_cpu_context
*cpuctx
,
1867 struct perf_event_context
*ctx
)
1869 u64 tstamp
= perf_event_time(event
);
1872 lockdep_assert_held(&ctx
->lock
);
1874 if (event
->state
<= PERF_EVENT_STATE_OFF
)
1877 event
->state
= PERF_EVENT_STATE_ACTIVE
;
1878 event
->oncpu
= smp_processor_id();
1881 * Unthrottle events, since we scheduled we might have missed several
1882 * ticks already, also for a heavily scheduling task there is little
1883 * guarantee it'll get a tick in a timely manner.
1885 if (unlikely(event
->hw
.interrupts
== MAX_INTERRUPTS
)) {
1886 perf_log_throttle(event
, 1);
1887 event
->hw
.interrupts
= 0;
1891 * The new state must be visible before we turn it on in the hardware:
1895 perf_pmu_disable(event
->pmu
);
1897 perf_set_shadow_time(event
, ctx
, tstamp
);
1899 perf_log_itrace_start(event
);
1901 if (event
->pmu
->add(event
, PERF_EF_START
)) {
1902 event
->state
= PERF_EVENT_STATE_INACTIVE
;
1908 event
->tstamp_running
+= tstamp
- event
->tstamp_stopped
;
1910 if (!is_software_event(event
))
1911 cpuctx
->active_oncpu
++;
1912 if (!ctx
->nr_active
++)
1913 perf_event_ctx_activate(ctx
);
1914 if (event
->attr
.freq
&& event
->attr
.sample_freq
)
1917 if (event
->attr
.exclusive
)
1918 cpuctx
->exclusive
= 1;
1920 if (is_orphaned_child(event
))
1921 schedule_orphans_remove(ctx
);
1924 perf_pmu_enable(event
->pmu
);
1930 group_sched_in(struct perf_event
*group_event
,
1931 struct perf_cpu_context
*cpuctx
,
1932 struct perf_event_context
*ctx
)
1934 struct perf_event
*event
, *partial_group
= NULL
;
1935 struct pmu
*pmu
= ctx
->pmu
;
1936 u64 now
= ctx
->time
;
1937 bool simulate
= false;
1939 if (group_event
->state
== PERF_EVENT_STATE_OFF
)
1942 pmu
->start_txn(pmu
, PERF_PMU_TXN_ADD
);
1944 if (event_sched_in(group_event
, cpuctx
, ctx
)) {
1945 pmu
->cancel_txn(pmu
);
1946 perf_mux_hrtimer_restart(cpuctx
);
1951 * Schedule in siblings as one group (if any):
1953 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1954 if (event_sched_in(event
, cpuctx
, ctx
)) {
1955 partial_group
= event
;
1960 if (!pmu
->commit_txn(pmu
))
1965 * Groups can be scheduled in as one unit only, so undo any
1966 * partial group before returning:
1967 * The events up to the failed event are scheduled out normally,
1968 * tstamp_stopped will be updated.
1970 * The failed events and the remaining siblings need to have
1971 * their timings updated as if they had gone thru event_sched_in()
1972 * and event_sched_out(). This is required to get consistent timings
1973 * across the group. This also takes care of the case where the group
1974 * could never be scheduled by ensuring tstamp_stopped is set to mark
1975 * the time the event was actually stopped, such that time delta
1976 * calculation in update_event_times() is correct.
1978 list_for_each_entry(event
, &group_event
->sibling_list
, group_entry
) {
1979 if (event
== partial_group
)
1983 event
->tstamp_running
+= now
- event
->tstamp_stopped
;
1984 event
->tstamp_stopped
= now
;
1986 event_sched_out(event
, cpuctx
, ctx
);
1989 event_sched_out(group_event
, cpuctx
, ctx
);
1991 pmu
->cancel_txn(pmu
);
1993 perf_mux_hrtimer_restart(cpuctx
);
1999 * Work out whether we can put this event group on the CPU now.
2001 static int group_can_go_on(struct perf_event
*event
,
2002 struct perf_cpu_context
*cpuctx
,
2006 * Groups consisting entirely of software events can always go on.
2008 if (event
->group_flags
& PERF_GROUP_SOFTWARE
)
2011 * If an exclusive group is already on, no other hardware
2014 if (cpuctx
->exclusive
)
2017 * If this group is exclusive and there are already
2018 * events on the CPU, it can't go on.
2020 if (event
->attr
.exclusive
&& cpuctx
->active_oncpu
)
2023 * Otherwise, try to add it if all previous groups were able
2029 static void add_event_to_ctx(struct perf_event
*event
,
2030 struct perf_event_context
*ctx
)
2032 u64 tstamp
= perf_event_time(event
);
2034 list_add_event(event
, ctx
);
2035 perf_group_attach(event
);
2036 event
->tstamp_enabled
= tstamp
;
2037 event
->tstamp_running
= tstamp
;
2038 event
->tstamp_stopped
= tstamp
;
2041 static void task_ctx_sched_out(struct perf_event_context
*ctx
);
2043 ctx_sched_in(struct perf_event_context
*ctx
,
2044 struct perf_cpu_context
*cpuctx
,
2045 enum event_type_t event_type
,
2046 struct task_struct
*task
);
2048 static void perf_event_sched_in(struct perf_cpu_context
*cpuctx
,
2049 struct perf_event_context
*ctx
,
2050 struct task_struct
*task
)
2052 cpu_ctx_sched_in(cpuctx
, EVENT_PINNED
, task
);
2054 ctx_sched_in(ctx
, cpuctx
, EVENT_PINNED
, task
);
2055 cpu_ctx_sched_in(cpuctx
, EVENT_FLEXIBLE
, task
);
2057 ctx_sched_in(ctx
, cpuctx
, EVENT_FLEXIBLE
, task
);
2061 * Cross CPU call to install and enable a performance event
2063 * Must be called with ctx->mutex held
2065 static int __perf_install_in_context(void *info
)
2067 struct perf_event
*event
= info
;
2068 struct perf_event_context
*ctx
= event
->ctx
;
2069 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2070 struct perf_event_context
*task_ctx
= cpuctx
->task_ctx
;
2071 struct task_struct
*task
= current
;
2073 perf_ctx_lock(cpuctx
, task_ctx
);
2074 perf_pmu_disable(cpuctx
->ctx
.pmu
);
2077 * If there was an active task_ctx schedule it out.
2080 task_ctx_sched_out(task_ctx
);
2083 * If the context we're installing events in is not the
2084 * active task_ctx, flip them.
2086 if (ctx
->task
&& task_ctx
!= ctx
) {
2088 raw_spin_unlock(&task_ctx
->lock
);
2089 raw_spin_lock(&ctx
->lock
);
2094 cpuctx
->task_ctx
= task_ctx
;
2095 task
= task_ctx
->task
;
2098 cpu_ctx_sched_out(cpuctx
, EVENT_ALL
);
2100 update_context_time(ctx
);
2102 * update cgrp time only if current cgrp
2103 * matches event->cgrp. Must be done before
2104 * calling add_event_to_ctx()
2106 update_cgrp_time_from_event(event
);
2108 add_event_to_ctx(event
, ctx
);
2111 * Schedule everything back in
2113 perf_event_sched_in(cpuctx
, task_ctx
, task
);
2115 perf_pmu_enable(cpuctx
->ctx
.pmu
);
2116 perf_ctx_unlock(cpuctx
, task_ctx
);
2122 * Attach a performance event to a context
2124 * First we add the event to the list with the hardware enable bit
2125 * in event->hw_config cleared.
2127 * If the event is attached to a task which is on a CPU we use a smp
2128 * call to enable it in the task context. The task might have been
2129 * scheduled away, but we check this in the smp call again.
2132 perf_install_in_context(struct perf_event_context
*ctx
,
2133 struct perf_event
*event
,
2136 struct task_struct
*task
= ctx
->task
;
2138 lockdep_assert_held(&ctx
->mutex
);
2141 if (event
->cpu
!= -1)
2146 * Per cpu events are installed via an smp call and
2147 * the install is always successful.
2149 cpu_function_call(cpu
, __perf_install_in_context
, event
);
2154 if (!task_function_call(task
, __perf_install_in_context
, event
))
2157 raw_spin_lock_irq(&ctx
->lock
);
2159 * If we failed to find a running task, but find the context active now
2160 * that we've acquired the ctx->lock, retry.
2162 if (ctx
->is_active
) {
2163 raw_spin_unlock_irq(&ctx
->lock
);
2165 * Reload the task pointer, it might have been changed by
2166 * a concurrent perf_event_context_sched_out().
2173 * Since the task isn't running, its safe to add the event, us holding
2174 * the ctx->lock ensures the task won't get scheduled in.
2176 add_event_to_ctx(event
, ctx
);
2177 raw_spin_unlock_irq(&ctx
->lock
);
2181 * Put a event into inactive state and update time fields.
2182 * Enabling the leader of a group effectively enables all
2183 * the group members that aren't explicitly disabled, so we
2184 * have to update their ->tstamp_enabled also.
2185 * Note: this works for group members as well as group leaders
2186 * since the non-leader members' sibling_lists will be empty.
2188 static void __perf_event_mark_enabled(struct perf_event
*event
)
2190 struct perf_event
*sub
;
2191 u64 tstamp
= perf_event_time(event
);
2193 event
->state
= PERF_EVENT_STATE_INACTIVE
;
2194 event
->tstamp_enabled
= tstamp
- event
->total_time_enabled
;
2195 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
2196 if (sub
->state
>= PERF_EVENT_STATE_INACTIVE
)
2197 sub
->tstamp_enabled
= tstamp
- sub
->total_time_enabled
;
2202 * Cross CPU call to enable a performance event
2204 static int __perf_event_enable(void *info
)
2206 struct perf_event
*event
= info
;
2207 struct perf_event_context
*ctx
= event
->ctx
;
2208 struct perf_event
*leader
= event
->group_leader
;
2209 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2213 * There's a time window between 'ctx->is_active' check
2214 * in perf_event_enable function and this place having:
2216 * - ctx->lock unlocked
2218 * where the task could be killed and 'ctx' deactivated
2219 * by perf_event_exit_task.
2221 if (!ctx
->is_active
)
2224 raw_spin_lock(&ctx
->lock
);
2225 update_context_time(ctx
);
2227 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2231 * set current task's cgroup time reference point
2233 perf_cgroup_set_timestamp(current
, ctx
);
2235 __perf_event_mark_enabled(event
);
2237 if (!event_filter_match(event
)) {
2238 if (is_cgroup_event(event
))
2239 perf_cgroup_defer_enabled(event
);
2244 * If the event is in a group and isn't the group leader,
2245 * then don't put it on unless the group is on.
2247 if (leader
!= event
&& leader
->state
!= PERF_EVENT_STATE_ACTIVE
)
2250 if (!group_can_go_on(event
, cpuctx
, 1)) {
2253 if (event
== leader
)
2254 err
= group_sched_in(event
, cpuctx
, ctx
);
2256 err
= event_sched_in(event
, cpuctx
, ctx
);
2261 * If this event can't go on and it's part of a
2262 * group, then the whole group has to come off.
2264 if (leader
!= event
) {
2265 group_sched_out(leader
, cpuctx
, ctx
);
2266 perf_mux_hrtimer_restart(cpuctx
);
2268 if (leader
->attr
.pinned
) {
2269 update_group_times(leader
);
2270 leader
->state
= PERF_EVENT_STATE_ERROR
;
2275 raw_spin_unlock(&ctx
->lock
);
2283 * If event->ctx is a cloned context, callers must make sure that
2284 * every task struct that event->ctx->task could possibly point to
2285 * remains valid. This condition is satisfied when called through
2286 * perf_event_for_each_child or perf_event_for_each as described
2287 * for perf_event_disable.
2289 static void _perf_event_enable(struct perf_event
*event
)
2291 struct perf_event_context
*ctx
= event
->ctx
;
2292 struct task_struct
*task
= ctx
->task
;
2296 * Enable the event on the cpu that it's on
2298 cpu_function_call(event
->cpu
, __perf_event_enable
, event
);
2302 raw_spin_lock_irq(&ctx
->lock
);
2303 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
2307 * If the event is in error state, clear that first.
2308 * That way, if we see the event in error state below, we
2309 * know that it has gone back into error state, as distinct
2310 * from the task having been scheduled away before the
2311 * cross-call arrived.
2313 if (event
->state
== PERF_EVENT_STATE_ERROR
)
2314 event
->state
= PERF_EVENT_STATE_OFF
;
2317 if (!ctx
->is_active
) {
2318 __perf_event_mark_enabled(event
);
2322 raw_spin_unlock_irq(&ctx
->lock
);
2324 if (!task_function_call(task
, __perf_event_enable
, event
))
2327 raw_spin_lock_irq(&ctx
->lock
);
2330 * If the context is active and the event is still off,
2331 * we need to retry the cross-call.
2333 if (ctx
->is_active
&& event
->state
== PERF_EVENT_STATE_OFF
) {
2335 * task could have been flipped by a concurrent
2336 * perf_event_context_sched_out()
2343 raw_spin_unlock_irq(&ctx
->lock
);
2347 * See perf_event_disable();
2349 void perf_event_enable(struct perf_event
*event
)
2351 struct perf_event_context
*ctx
;
2353 ctx
= perf_event_ctx_lock(event
);
2354 _perf_event_enable(event
);
2355 perf_event_ctx_unlock(event
, ctx
);
2357 EXPORT_SYMBOL_GPL(perf_event_enable
);
2359 static int _perf_event_refresh(struct perf_event
*event
, int refresh
)
2362 * not supported on inherited events
2364 if (event
->attr
.inherit
|| !is_sampling_event(event
))
2367 atomic_add(refresh
, &event
->event_limit
);
2368 _perf_event_enable(event
);
2374 * See perf_event_disable()
2376 int perf_event_refresh(struct perf_event
*event
, int refresh
)
2378 struct perf_event_context
*ctx
;
2381 ctx
= perf_event_ctx_lock(event
);
2382 ret
= _perf_event_refresh(event
, refresh
);
2383 perf_event_ctx_unlock(event
, ctx
);
2387 EXPORT_SYMBOL_GPL(perf_event_refresh
);
2389 static void ctx_sched_out(struct perf_event_context
*ctx
,
2390 struct perf_cpu_context
*cpuctx
,
2391 enum event_type_t event_type
)
2393 struct perf_event
*event
;
2394 int is_active
= ctx
->is_active
;
2396 ctx
->is_active
&= ~event_type
;
2397 if (likely(!ctx
->nr_events
))
2400 update_context_time(ctx
);
2401 update_cgrp_time_from_cpuctx(cpuctx
);
2402 if (!ctx
->nr_active
)
2405 perf_pmu_disable(ctx
->pmu
);
2406 if ((is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
)) {
2407 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
)
2408 group_sched_out(event
, cpuctx
, ctx
);
2411 if ((is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
)) {
2412 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
)
2413 group_sched_out(event
, cpuctx
, ctx
);
2415 perf_pmu_enable(ctx
->pmu
);
2419 * Test whether two contexts are equivalent, i.e. whether they have both been
2420 * cloned from the same version of the same context.
2422 * Equivalence is measured using a generation number in the context that is
2423 * incremented on each modification to it; see unclone_ctx(), list_add_event()
2424 * and list_del_event().
2426 static int context_equiv(struct perf_event_context
*ctx1
,
2427 struct perf_event_context
*ctx2
)
2429 lockdep_assert_held(&ctx1
->lock
);
2430 lockdep_assert_held(&ctx2
->lock
);
2432 /* Pinning disables the swap optimization */
2433 if (ctx1
->pin_count
|| ctx2
->pin_count
)
2436 /* If ctx1 is the parent of ctx2 */
2437 if (ctx1
== ctx2
->parent_ctx
&& ctx1
->generation
== ctx2
->parent_gen
)
2440 /* If ctx2 is the parent of ctx1 */
2441 if (ctx1
->parent_ctx
== ctx2
&& ctx1
->parent_gen
== ctx2
->generation
)
2445 * If ctx1 and ctx2 have the same parent; we flatten the parent
2446 * hierarchy, see perf_event_init_context().
2448 if (ctx1
->parent_ctx
&& ctx1
->parent_ctx
== ctx2
->parent_ctx
&&
2449 ctx1
->parent_gen
== ctx2
->parent_gen
)
2456 static void __perf_event_sync_stat(struct perf_event
*event
,
2457 struct perf_event
*next_event
)
2461 if (!event
->attr
.inherit_stat
)
2465 * Update the event value, we cannot use perf_event_read()
2466 * because we're in the middle of a context switch and have IRQs
2467 * disabled, which upsets smp_call_function_single(), however
2468 * we know the event must be on the current CPU, therefore we
2469 * don't need to use it.
2471 switch (event
->state
) {
2472 case PERF_EVENT_STATE_ACTIVE
:
2473 event
->pmu
->read(event
);
2476 case PERF_EVENT_STATE_INACTIVE
:
2477 update_event_times(event
);
2485 * In order to keep per-task stats reliable we need to flip the event
2486 * values when we flip the contexts.
2488 value
= local64_read(&next_event
->count
);
2489 value
= local64_xchg(&event
->count
, value
);
2490 local64_set(&next_event
->count
, value
);
2492 swap(event
->total_time_enabled
, next_event
->total_time_enabled
);
2493 swap(event
->total_time_running
, next_event
->total_time_running
);
2496 * Since we swizzled the values, update the user visible data too.
2498 perf_event_update_userpage(event
);
2499 perf_event_update_userpage(next_event
);
2502 static void perf_event_sync_stat(struct perf_event_context
*ctx
,
2503 struct perf_event_context
*next_ctx
)
2505 struct perf_event
*event
, *next_event
;
2510 update_context_time(ctx
);
2512 event
= list_first_entry(&ctx
->event_list
,
2513 struct perf_event
, event_entry
);
2515 next_event
= list_first_entry(&next_ctx
->event_list
,
2516 struct perf_event
, event_entry
);
2518 while (&event
->event_entry
!= &ctx
->event_list
&&
2519 &next_event
->event_entry
!= &next_ctx
->event_list
) {
2521 __perf_event_sync_stat(event
, next_event
);
2523 event
= list_next_entry(event
, event_entry
);
2524 next_event
= list_next_entry(next_event
, event_entry
);
2528 static void perf_event_context_sched_out(struct task_struct
*task
, int ctxn
,
2529 struct task_struct
*next
)
2531 struct perf_event_context
*ctx
= task
->perf_event_ctxp
[ctxn
];
2532 struct perf_event_context
*next_ctx
;
2533 struct perf_event_context
*parent
, *next_parent
;
2534 struct perf_cpu_context
*cpuctx
;
2540 cpuctx
= __get_cpu_context(ctx
);
2541 if (!cpuctx
->task_ctx
)
2545 next_ctx
= next
->perf_event_ctxp
[ctxn
];
2549 parent
= rcu_dereference(ctx
->parent_ctx
);
2550 next_parent
= rcu_dereference(next_ctx
->parent_ctx
);
2552 /* If neither context have a parent context; they cannot be clones. */
2553 if (!parent
&& !next_parent
)
2556 if (next_parent
== ctx
|| next_ctx
== parent
|| next_parent
== parent
) {
2558 * Looks like the two contexts are clones, so we might be
2559 * able to optimize the context switch. We lock both
2560 * contexts and check that they are clones under the
2561 * lock (including re-checking that neither has been
2562 * uncloned in the meantime). It doesn't matter which
2563 * order we take the locks because no other cpu could
2564 * be trying to lock both of these tasks.
2566 raw_spin_lock(&ctx
->lock
);
2567 raw_spin_lock_nested(&next_ctx
->lock
, SINGLE_DEPTH_NESTING
);
2568 if (context_equiv(ctx
, next_ctx
)) {
2570 * XXX do we need a memory barrier of sorts
2571 * wrt to rcu_dereference() of perf_event_ctxp
2573 task
->perf_event_ctxp
[ctxn
] = next_ctx
;
2574 next
->perf_event_ctxp
[ctxn
] = ctx
;
2576 next_ctx
->task
= task
;
2578 swap(ctx
->task_ctx_data
, next_ctx
->task_ctx_data
);
2582 perf_event_sync_stat(ctx
, next_ctx
);
2584 raw_spin_unlock(&next_ctx
->lock
);
2585 raw_spin_unlock(&ctx
->lock
);
2591 raw_spin_lock(&ctx
->lock
);
2592 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2593 cpuctx
->task_ctx
= NULL
;
2594 raw_spin_unlock(&ctx
->lock
);
2598 void perf_sched_cb_dec(struct pmu
*pmu
)
2600 this_cpu_dec(perf_sched_cb_usages
);
2603 void perf_sched_cb_inc(struct pmu
*pmu
)
2605 this_cpu_inc(perf_sched_cb_usages
);
2609 * This function provides the context switch callback to the lower code
2610 * layer. It is invoked ONLY when the context switch callback is enabled.
2612 static void perf_pmu_sched_task(struct task_struct
*prev
,
2613 struct task_struct
*next
,
2616 struct perf_cpu_context
*cpuctx
;
2618 unsigned long flags
;
2623 local_irq_save(flags
);
2627 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
2628 if (pmu
->sched_task
) {
2629 cpuctx
= this_cpu_ptr(pmu
->pmu_cpu_context
);
2631 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
2633 perf_pmu_disable(pmu
);
2635 pmu
->sched_task(cpuctx
->task_ctx
, sched_in
);
2637 perf_pmu_enable(pmu
);
2639 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
2645 local_irq_restore(flags
);
2648 static void perf_event_switch(struct task_struct
*task
,
2649 struct task_struct
*next_prev
, bool sched_in
);
2651 #define for_each_task_context_nr(ctxn) \
2652 for ((ctxn) = 0; (ctxn) < perf_nr_task_contexts; (ctxn)++)
2655 * Called from scheduler to remove the events of the current task,
2656 * with interrupts disabled.
2658 * We stop each event and update the event value in event->count.
2660 * This does not protect us against NMI, but disable()
2661 * sets the disabled bit in the control field of event _before_
2662 * accessing the event control register. If a NMI hits, then it will
2663 * not restart the event.
2665 void __perf_event_task_sched_out(struct task_struct
*task
,
2666 struct task_struct
*next
)
2670 if (__this_cpu_read(perf_sched_cb_usages
))
2671 perf_pmu_sched_task(task
, next
, false);
2673 if (atomic_read(&nr_switch_events
))
2674 perf_event_switch(task
, next
, false);
2676 for_each_task_context_nr(ctxn
)
2677 perf_event_context_sched_out(task
, ctxn
, next
);
2680 * if cgroup events exist on this CPU, then we need
2681 * to check if we have to switch out PMU state.
2682 * cgroup event are system-wide mode only
2684 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2685 perf_cgroup_sched_out(task
, next
);
2688 static void task_ctx_sched_out(struct perf_event_context
*ctx
)
2690 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
2692 if (!cpuctx
->task_ctx
)
2695 if (WARN_ON_ONCE(ctx
!= cpuctx
->task_ctx
))
2698 ctx_sched_out(ctx
, cpuctx
, EVENT_ALL
);
2699 cpuctx
->task_ctx
= NULL
;
2703 * Called with IRQs disabled
2705 static void cpu_ctx_sched_out(struct perf_cpu_context
*cpuctx
,
2706 enum event_type_t event_type
)
2708 ctx_sched_out(&cpuctx
->ctx
, cpuctx
, event_type
);
2712 ctx_pinned_sched_in(struct perf_event_context
*ctx
,
2713 struct perf_cpu_context
*cpuctx
)
2715 struct perf_event
*event
;
2717 list_for_each_entry(event
, &ctx
->pinned_groups
, group_entry
) {
2718 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2720 if (!event_filter_match(event
))
2723 /* may need to reset tstamp_enabled */
2724 if (is_cgroup_event(event
))
2725 perf_cgroup_mark_enabled(event
, ctx
);
2727 if (group_can_go_on(event
, cpuctx
, 1))
2728 group_sched_in(event
, cpuctx
, ctx
);
2731 * If this pinned group hasn't been scheduled,
2732 * put it in error state.
2734 if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
2735 update_group_times(event
);
2736 event
->state
= PERF_EVENT_STATE_ERROR
;
2742 ctx_flexible_sched_in(struct perf_event_context
*ctx
,
2743 struct perf_cpu_context
*cpuctx
)
2745 struct perf_event
*event
;
2748 list_for_each_entry(event
, &ctx
->flexible_groups
, group_entry
) {
2749 /* Ignore events in OFF or ERROR state */
2750 if (event
->state
<= PERF_EVENT_STATE_OFF
)
2753 * Listen to the 'cpu' scheduling filter constraint
2756 if (!event_filter_match(event
))
2759 /* may need to reset tstamp_enabled */
2760 if (is_cgroup_event(event
))
2761 perf_cgroup_mark_enabled(event
, ctx
);
2763 if (group_can_go_on(event
, cpuctx
, can_add_hw
)) {
2764 if (group_sched_in(event
, cpuctx
, ctx
))
2771 ctx_sched_in(struct perf_event_context
*ctx
,
2772 struct perf_cpu_context
*cpuctx
,
2773 enum event_type_t event_type
,
2774 struct task_struct
*task
)
2777 int is_active
= ctx
->is_active
;
2779 ctx
->is_active
|= event_type
;
2780 if (likely(!ctx
->nr_events
))
2784 ctx
->timestamp
= now
;
2785 perf_cgroup_set_timestamp(task
, ctx
);
2787 * First go through the list and put on any pinned groups
2788 * in order to give them the best chance of going on.
2790 if (!(is_active
& EVENT_PINNED
) && (event_type
& EVENT_PINNED
))
2791 ctx_pinned_sched_in(ctx
, cpuctx
);
2793 /* Then walk through the lower prio flexible groups */
2794 if (!(is_active
& EVENT_FLEXIBLE
) && (event_type
& EVENT_FLEXIBLE
))
2795 ctx_flexible_sched_in(ctx
, cpuctx
);
2798 static void cpu_ctx_sched_in(struct perf_cpu_context
*cpuctx
,
2799 enum event_type_t event_type
,
2800 struct task_struct
*task
)
2802 struct perf_event_context
*ctx
= &cpuctx
->ctx
;
2804 ctx_sched_in(ctx
, cpuctx
, event_type
, task
);
2807 static void perf_event_context_sched_in(struct perf_event_context
*ctx
,
2808 struct task_struct
*task
)
2810 struct perf_cpu_context
*cpuctx
;
2812 cpuctx
= __get_cpu_context(ctx
);
2813 if (cpuctx
->task_ctx
== ctx
)
2816 perf_ctx_lock(cpuctx
, ctx
);
2817 perf_pmu_disable(ctx
->pmu
);
2819 * We want to keep the following priority order:
2820 * cpu pinned (that don't need to move), task pinned,
2821 * cpu flexible, task flexible.
2823 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
2826 cpuctx
->task_ctx
= ctx
;
2828 perf_event_sched_in(cpuctx
, cpuctx
->task_ctx
, task
);
2830 perf_pmu_enable(ctx
->pmu
);
2831 perf_ctx_unlock(cpuctx
, ctx
);
2835 * Called from scheduler to add the events of the current task
2836 * with interrupts disabled.
2838 * We restore the event value and then enable it.
2840 * This does not protect us against NMI, but enable()
2841 * sets the enabled bit in the control field of event _before_
2842 * accessing the event control register. If a NMI hits, then it will
2843 * keep the event running.
2845 void __perf_event_task_sched_in(struct task_struct
*prev
,
2846 struct task_struct
*task
)
2848 struct perf_event_context
*ctx
;
2851 for_each_task_context_nr(ctxn
) {
2852 ctx
= task
->perf_event_ctxp
[ctxn
];
2856 perf_event_context_sched_in(ctx
, task
);
2859 * if cgroup events exist on this CPU, then we need
2860 * to check if we have to switch in PMU state.
2861 * cgroup event are system-wide mode only
2863 if (atomic_read(this_cpu_ptr(&perf_cgroup_events
)))
2864 perf_cgroup_sched_in(prev
, task
);
2866 if (atomic_read(&nr_switch_events
))
2867 perf_event_switch(task
, prev
, true);
2869 if (__this_cpu_read(perf_sched_cb_usages
))
2870 perf_pmu_sched_task(prev
, task
, true);
2873 static u64
perf_calculate_period(struct perf_event
*event
, u64 nsec
, u64 count
)
2875 u64 frequency
= event
->attr
.sample_freq
;
2876 u64 sec
= NSEC_PER_SEC
;
2877 u64 divisor
, dividend
;
2879 int count_fls
, nsec_fls
, frequency_fls
, sec_fls
;
2881 count_fls
= fls64(count
);
2882 nsec_fls
= fls64(nsec
);
2883 frequency_fls
= fls64(frequency
);
2887 * We got @count in @nsec, with a target of sample_freq HZ
2888 * the target period becomes:
2891 * period = -------------------
2892 * @nsec * sample_freq
2897 * Reduce accuracy by one bit such that @a and @b converge
2898 * to a similar magnitude.
2900 #define REDUCE_FLS(a, b) \
2902 if (a##_fls > b##_fls) { \
2912 * Reduce accuracy until either term fits in a u64, then proceed with
2913 * the other, so that finally we can do a u64/u64 division.
2915 while (count_fls
+ sec_fls
> 64 && nsec_fls
+ frequency_fls
> 64) {
2916 REDUCE_FLS(nsec
, frequency
);
2917 REDUCE_FLS(sec
, count
);
2920 if (count_fls
+ sec_fls
> 64) {
2921 divisor
= nsec
* frequency
;
2923 while (count_fls
+ sec_fls
> 64) {
2924 REDUCE_FLS(count
, sec
);
2928 dividend
= count
* sec
;
2930 dividend
= count
* sec
;
2932 while (nsec_fls
+ frequency_fls
> 64) {
2933 REDUCE_FLS(nsec
, frequency
);
2937 divisor
= nsec
* frequency
;
2943 return div64_u64(dividend
, divisor
);
2946 static DEFINE_PER_CPU(int, perf_throttled_count
);
2947 static DEFINE_PER_CPU(u64
, perf_throttled_seq
);
2949 static void perf_adjust_period(struct perf_event
*event
, u64 nsec
, u64 count
, bool disable
)
2951 struct hw_perf_event
*hwc
= &event
->hw
;
2952 s64 period
, sample_period
;
2955 period
= perf_calculate_period(event
, nsec
, count
);
2957 delta
= (s64
)(period
- hwc
->sample_period
);
2958 delta
= (delta
+ 7) / 8; /* low pass filter */
2960 sample_period
= hwc
->sample_period
+ delta
;
2965 hwc
->sample_period
= sample_period
;
2967 if (local64_read(&hwc
->period_left
) > 8*sample_period
) {
2969 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
2971 local64_set(&hwc
->period_left
, 0);
2974 event
->pmu
->start(event
, PERF_EF_RELOAD
);
2979 * combine freq adjustment with unthrottling to avoid two passes over the
2980 * events. At the same time, make sure, having freq events does not change
2981 * the rate of unthrottling as that would introduce bias.
2983 static void perf_adjust_freq_unthr_context(struct perf_event_context
*ctx
,
2986 struct perf_event
*event
;
2987 struct hw_perf_event
*hwc
;
2988 u64 now
, period
= TICK_NSEC
;
2992 * only need to iterate over all events iff:
2993 * - context have events in frequency mode (needs freq adjust)
2994 * - there are events to unthrottle on this cpu
2996 if (!(ctx
->nr_freq
|| needs_unthr
))
2999 raw_spin_lock(&ctx
->lock
);
3000 perf_pmu_disable(ctx
->pmu
);
3002 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
3003 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3006 if (!event_filter_match(event
))
3009 perf_pmu_disable(event
->pmu
);
3013 if (hwc
->interrupts
== MAX_INTERRUPTS
) {
3014 hwc
->interrupts
= 0;
3015 perf_log_throttle(event
, 1);
3016 event
->pmu
->start(event
, 0);
3019 if (!event
->attr
.freq
|| !event
->attr
.sample_freq
)
3023 * stop the event and update event->count
3025 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
3027 now
= local64_read(&event
->count
);
3028 delta
= now
- hwc
->freq_count_stamp
;
3029 hwc
->freq_count_stamp
= now
;
3033 * reload only if value has changed
3034 * we have stopped the event so tell that
3035 * to perf_adjust_period() to avoid stopping it
3039 perf_adjust_period(event
, period
, delta
, false);
3041 event
->pmu
->start(event
, delta
> 0 ? PERF_EF_RELOAD
: 0);
3043 perf_pmu_enable(event
->pmu
);
3046 perf_pmu_enable(ctx
->pmu
);
3047 raw_spin_unlock(&ctx
->lock
);
3051 * Round-robin a context's events:
3053 static void rotate_ctx(struct perf_event_context
*ctx
)
3056 * Rotate the first entry last of non-pinned groups. Rotation might be
3057 * disabled by the inheritance code.
3059 if (!ctx
->rotate_disable
)
3060 list_rotate_left(&ctx
->flexible_groups
);
3063 static int perf_rotate_context(struct perf_cpu_context
*cpuctx
)
3065 struct perf_event_context
*ctx
= NULL
;
3068 if (cpuctx
->ctx
.nr_events
) {
3069 if (cpuctx
->ctx
.nr_events
!= cpuctx
->ctx
.nr_active
)
3073 ctx
= cpuctx
->task_ctx
;
3074 if (ctx
&& ctx
->nr_events
) {
3075 if (ctx
->nr_events
!= ctx
->nr_active
)
3082 perf_ctx_lock(cpuctx
, cpuctx
->task_ctx
);
3083 perf_pmu_disable(cpuctx
->ctx
.pmu
);
3085 cpu_ctx_sched_out(cpuctx
, EVENT_FLEXIBLE
);
3087 ctx_sched_out(ctx
, cpuctx
, EVENT_FLEXIBLE
);
3089 rotate_ctx(&cpuctx
->ctx
);
3093 perf_event_sched_in(cpuctx
, ctx
, current
);
3095 perf_pmu_enable(cpuctx
->ctx
.pmu
);
3096 perf_ctx_unlock(cpuctx
, cpuctx
->task_ctx
);
3102 #ifdef CONFIG_NO_HZ_FULL
3103 bool perf_event_can_stop_tick(void)
3105 if (atomic_read(&nr_freq_events
) ||
3106 __this_cpu_read(perf_throttled_count
))
3113 void perf_event_task_tick(void)
3115 struct list_head
*head
= this_cpu_ptr(&active_ctx_list
);
3116 struct perf_event_context
*ctx
, *tmp
;
3119 WARN_ON(!irqs_disabled());
3121 __this_cpu_inc(perf_throttled_seq
);
3122 throttled
= __this_cpu_xchg(perf_throttled_count
, 0);
3124 list_for_each_entry_safe(ctx
, tmp
, head
, active_ctx_list
)
3125 perf_adjust_freq_unthr_context(ctx
, throttled
);
3128 static int event_enable_on_exec(struct perf_event
*event
,
3129 struct perf_event_context
*ctx
)
3131 if (!event
->attr
.enable_on_exec
)
3134 event
->attr
.enable_on_exec
= 0;
3135 if (event
->state
>= PERF_EVENT_STATE_INACTIVE
)
3138 __perf_event_mark_enabled(event
);
3144 * Enable all of a task's events that have been marked enable-on-exec.
3145 * This expects task == current.
3147 static void perf_event_enable_on_exec(struct perf_event_context
*ctx
)
3149 struct perf_event_context
*clone_ctx
= NULL
;
3150 struct perf_event
*event
;
3151 unsigned long flags
;
3155 local_irq_save(flags
);
3156 if (!ctx
|| !ctx
->nr_events
)
3160 * We must ctxsw out cgroup events to avoid conflict
3161 * when invoking perf_task_event_sched_in() later on
3162 * in this function. Otherwise we end up trying to
3163 * ctxswin cgroup events which are already scheduled
3166 perf_cgroup_sched_out(current
, NULL
);
3168 raw_spin_lock(&ctx
->lock
);
3169 task_ctx_sched_out(ctx
);
3171 list_for_each_entry(event
, &ctx
->event_list
, event_entry
) {
3172 ret
= event_enable_on_exec(event
, ctx
);
3178 * Unclone this context if we enabled any event.
3181 clone_ctx
= unclone_ctx(ctx
);
3183 raw_spin_unlock(&ctx
->lock
);
3186 * Also calls ctxswin for cgroup events, if any:
3188 perf_event_context_sched_in(ctx
, ctx
->task
);
3190 local_irq_restore(flags
);
3196 void perf_event_exec(void)
3198 struct perf_event_context
*ctx
;
3202 for_each_task_context_nr(ctxn
) {
3203 ctx
= current
->perf_event_ctxp
[ctxn
];
3207 perf_event_enable_on_exec(ctx
);
3212 struct perf_read_data
{
3213 struct perf_event
*event
;
3219 * Cross CPU call to read the hardware event
3221 static void __perf_event_read(void *info
)
3223 struct perf_read_data
*data
= info
;
3224 struct perf_event
*sub
, *event
= data
->event
;
3225 struct perf_event_context
*ctx
= event
->ctx
;
3226 struct perf_cpu_context
*cpuctx
= __get_cpu_context(ctx
);
3227 struct pmu
*pmu
= event
->pmu
;
3230 * If this is a task context, we need to check whether it is
3231 * the current task context of this cpu. If not it has been
3232 * scheduled out before the smp call arrived. In that case
3233 * event->count would have been updated to a recent sample
3234 * when the event was scheduled out.
3236 if (ctx
->task
&& cpuctx
->task_ctx
!= ctx
)
3239 raw_spin_lock(&ctx
->lock
);
3240 if (ctx
->is_active
) {
3241 update_context_time(ctx
);
3242 update_cgrp_time_from_event(event
);
3245 update_event_times(event
);
3246 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
3255 pmu
->start_txn(pmu
, PERF_PMU_TXN_READ
);
3259 list_for_each_entry(sub
, &event
->sibling_list
, group_entry
) {
3260 update_event_times(sub
);
3261 if (sub
->state
== PERF_EVENT_STATE_ACTIVE
) {
3263 * Use sibling's PMU rather than @event's since
3264 * sibling could be on different (eg: software) PMU.
3266 sub
->pmu
->read(sub
);
3270 data
->ret
= pmu
->commit_txn(pmu
);
3273 raw_spin_unlock(&ctx
->lock
);
3276 static inline u64
perf_event_count(struct perf_event
*event
)
3278 if (event
->pmu
->count
)
3279 return event
->pmu
->count(event
);
3281 return __perf_event_count(event
);
3285 * NMI-safe method to read a local event, that is an event that
3287 * - either for the current task, or for this CPU
3288 * - does not have inherit set, for inherited task events
3289 * will not be local and we cannot read them atomically
3290 * - must not have a pmu::count method
3292 u64
perf_event_read_local(struct perf_event
*event
)
3294 unsigned long flags
;
3298 * Disabling interrupts avoids all counter scheduling (context
3299 * switches, timer based rotation and IPIs).
3301 local_irq_save(flags
);
3303 /* If this is a per-task event, it must be for current */
3304 WARN_ON_ONCE((event
->attach_state
& PERF_ATTACH_TASK
) &&
3305 event
->hw
.target
!= current
);
3307 /* If this is a per-CPU event, it must be for this CPU */
3308 WARN_ON_ONCE(!(event
->attach_state
& PERF_ATTACH_TASK
) &&
3309 event
->cpu
!= smp_processor_id());
3312 * It must not be an event with inherit set, we cannot read
3313 * all child counters from atomic context.
3315 WARN_ON_ONCE(event
->attr
.inherit
);
3318 * It must not have a pmu::count method, those are not
3321 WARN_ON_ONCE(event
->pmu
->count
);
3324 * If the event is currently on this CPU, its either a per-task event,
3325 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
3328 if (event
->oncpu
== smp_processor_id())
3329 event
->pmu
->read(event
);
3331 val
= local64_read(&event
->count
);
3332 local_irq_restore(flags
);
3337 static int perf_event_read(struct perf_event
*event
, bool group
)
3342 * If event is enabled and currently active on a CPU, update the
3343 * value in the event structure:
3345 if (event
->state
== PERF_EVENT_STATE_ACTIVE
) {
3346 struct perf_read_data data
= {
3351 smp_call_function_single(event
->oncpu
,
3352 __perf_event_read
, &data
, 1);
3354 } else if (event
->state
== PERF_EVENT_STATE_INACTIVE
) {
3355 struct perf_event_context
*ctx
= event
->ctx
;
3356 unsigned long flags
;
3358 raw_spin_lock_irqsave(&ctx
->lock
, flags
);
3360 * may read while context is not active
3361 * (e.g., thread is blocked), in that case
3362 * we cannot update context time
3364 if (ctx
->is_active
) {
3365 update_context_time(ctx
);
3366 update_cgrp_time_from_event(event
);
3369 update_group_times(event
);
3371 update_event_times(event
);
3372 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3379 * Initialize the perf_event context in a task_struct:
3381 static void __perf_event_init_context(struct perf_event_context
*ctx
)
3383 raw_spin_lock_init(&ctx
->lock
);
3384 mutex_init(&ctx
->mutex
);
3385 INIT_LIST_HEAD(&ctx
->active_ctx_list
);
3386 INIT_LIST_HEAD(&ctx
->pinned_groups
);
3387 INIT_LIST_HEAD(&ctx
->flexible_groups
);
3388 INIT_LIST_HEAD(&ctx
->event_list
);
3389 atomic_set(&ctx
->refcount
, 1);
3390 INIT_DELAYED_WORK(&ctx
->orphans_remove
, orphans_remove_work
);
3393 static struct perf_event_context
*
3394 alloc_perf_context(struct pmu
*pmu
, struct task_struct
*task
)
3396 struct perf_event_context
*ctx
;
3398 ctx
= kzalloc(sizeof(struct perf_event_context
), GFP_KERNEL
);
3402 __perf_event_init_context(ctx
);
3405 get_task_struct(task
);
3412 static struct task_struct
*
3413 find_lively_task_by_vpid(pid_t vpid
)
3415 struct task_struct
*task
;
3422 task
= find_task_by_vpid(vpid
);
3424 get_task_struct(task
);
3428 return ERR_PTR(-ESRCH
);
3430 /* Reuse ptrace permission checks for now. */
3432 if (!ptrace_may_access(task
, PTRACE_MODE_READ
))
3437 put_task_struct(task
);
3438 return ERR_PTR(err
);
3443 * Returns a matching context with refcount and pincount.
3445 static struct perf_event_context
*
3446 find_get_context(struct pmu
*pmu
, struct task_struct
*task
,
3447 struct perf_event
*event
)
3449 struct perf_event_context
*ctx
, *clone_ctx
= NULL
;
3450 struct perf_cpu_context
*cpuctx
;
3451 void *task_ctx_data
= NULL
;
3452 unsigned long flags
;
3454 int cpu
= event
->cpu
;
3457 /* Must be root to operate on a CPU event: */
3458 if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN
))
3459 return ERR_PTR(-EACCES
);
3462 * We could be clever and allow to attach a event to an
3463 * offline CPU and activate it when the CPU comes up, but
3466 if (!cpu_online(cpu
))
3467 return ERR_PTR(-ENODEV
);
3469 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
3478 ctxn
= pmu
->task_ctx_nr
;
3482 if (event
->attach_state
& PERF_ATTACH_TASK_DATA
) {
3483 task_ctx_data
= kzalloc(pmu
->task_ctx_size
, GFP_KERNEL
);
3484 if (!task_ctx_data
) {
3491 ctx
= perf_lock_task_context(task
, ctxn
, &flags
);
3493 clone_ctx
= unclone_ctx(ctx
);
3496 if (task_ctx_data
&& !ctx
->task_ctx_data
) {
3497 ctx
->task_ctx_data
= task_ctx_data
;
3498 task_ctx_data
= NULL
;
3500 raw_spin_unlock_irqrestore(&ctx
->lock
, flags
);
3505 ctx
= alloc_perf_context(pmu
, task
);
3510 if (task_ctx_data
) {
3511 ctx
->task_ctx_data
= task_ctx_data
;
3512 task_ctx_data
= NULL
;
3516 mutex_lock(&task
->perf_event_mutex
);
3518 * If it has already passed perf_event_exit_task().
3519 * we must see PF_EXITING, it takes this mutex too.
3521 if (task
->flags
& PF_EXITING
)
3523 else if (task
->perf_event_ctxp
[ctxn
])
3528 rcu_assign_pointer(task
->perf_event_ctxp
[ctxn
], ctx
);
3530 mutex_unlock(&task
->perf_event_mutex
);
3532 if (unlikely(err
)) {
3541 kfree(task_ctx_data
);
3545 kfree(task_ctx_data
);
3546 return ERR_PTR(err
);
3549 static void perf_event_free_filter(struct perf_event
*event
);
3550 static void perf_event_free_bpf_prog(struct perf_event
*event
);
3552 static void free_event_rcu(struct rcu_head
*head
)
3554 struct perf_event
*event
;
3556 event
= container_of(head
, struct perf_event
, rcu_head
);
3558 put_pid_ns(event
->ns
);
3559 perf_event_free_filter(event
);
3563 static void ring_buffer_attach(struct perf_event
*event
,
3564 struct ring_buffer
*rb
);
3566 static void unaccount_event_cpu(struct perf_event
*event
, int cpu
)
3571 if (is_cgroup_event(event
))
3572 atomic_dec(&per_cpu(perf_cgroup_events
, cpu
));
3575 static void unaccount_event(struct perf_event
*event
)
3580 if (event
->attach_state
& PERF_ATTACH_TASK
)
3581 static_key_slow_dec_deferred(&perf_sched_events
);
3582 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
3583 atomic_dec(&nr_mmap_events
);
3584 if (event
->attr
.comm
)
3585 atomic_dec(&nr_comm_events
);
3586 if (event
->attr
.task
)
3587 atomic_dec(&nr_task_events
);
3588 if (event
->attr
.freq
)
3589 atomic_dec(&nr_freq_events
);
3590 if (event
->attr
.context_switch
) {
3591 static_key_slow_dec_deferred(&perf_sched_events
);
3592 atomic_dec(&nr_switch_events
);
3594 if (is_cgroup_event(event
))
3595 static_key_slow_dec_deferred(&perf_sched_events
);
3596 if (has_branch_stack(event
))
3597 static_key_slow_dec_deferred(&perf_sched_events
);
3599 unaccount_event_cpu(event
, event
->cpu
);
3603 * The following implement mutual exclusion of events on "exclusive" pmus
3604 * (PERF_PMU_CAP_EXCLUSIVE). Such pmus can only have one event scheduled
3605 * at a time, so we disallow creating events that might conflict, namely:
3607 * 1) cpu-wide events in the presence of per-task events,
3608 * 2) per-task events in the presence of cpu-wide events,
3609 * 3) two matching events on the same context.
3611 * The former two cases are handled in the allocation path (perf_event_alloc(),
3612 * __free_event()), the latter -- before the first perf_install_in_context().
3614 static int exclusive_event_init(struct perf_event
*event
)
3616 struct pmu
*pmu
= event
->pmu
;
3618 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3622 * Prevent co-existence of per-task and cpu-wide events on the
3623 * same exclusive pmu.
3625 * Negative pmu::exclusive_cnt means there are cpu-wide
3626 * events on this "exclusive" pmu, positive means there are
3629 * Since this is called in perf_event_alloc() path, event::ctx
3630 * doesn't exist yet; it is, however, safe to use PERF_ATTACH_TASK
3631 * to mean "per-task event", because unlike other attach states it
3632 * never gets cleared.
3634 if (event
->attach_state
& PERF_ATTACH_TASK
) {
3635 if (!atomic_inc_unless_negative(&pmu
->exclusive_cnt
))
3638 if (!atomic_dec_unless_positive(&pmu
->exclusive_cnt
))
3645 static void exclusive_event_destroy(struct perf_event
*event
)
3647 struct pmu
*pmu
= event
->pmu
;
3649 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3652 /* see comment in exclusive_event_init() */
3653 if (event
->attach_state
& PERF_ATTACH_TASK
)
3654 atomic_dec(&pmu
->exclusive_cnt
);
3656 atomic_inc(&pmu
->exclusive_cnt
);
3659 static bool exclusive_event_match(struct perf_event
*e1
, struct perf_event
*e2
)
3661 if ((e1
->pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) &&
3662 (e1
->cpu
== e2
->cpu
||
3669 /* Called under the same ctx::mutex as perf_install_in_context() */
3670 static bool exclusive_event_installable(struct perf_event
*event
,
3671 struct perf_event_context
*ctx
)
3673 struct perf_event
*iter_event
;
3674 struct pmu
*pmu
= event
->pmu
;
3676 if (!(pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
))
3679 list_for_each_entry(iter_event
, &ctx
->event_list
, event_entry
) {
3680 if (exclusive_event_match(iter_event
, event
))
3687 static void __free_event(struct perf_event
*event
)
3689 if (!event
->parent
) {
3690 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
)
3691 put_callchain_buffers();
3694 perf_event_free_bpf_prog(event
);
3697 event
->destroy(event
);
3700 put_ctx(event
->ctx
);
3703 exclusive_event_destroy(event
);
3704 module_put(event
->pmu
->module
);
3707 call_rcu(&event
->rcu_head
, free_event_rcu
);
3710 static void _free_event(struct perf_event
*event
)
3712 irq_work_sync(&event
->pending
);
3714 unaccount_event(event
);
3718 * Can happen when we close an event with re-directed output.
3720 * Since we have a 0 refcount, perf_mmap_close() will skip
3721 * over us; possibly making our ring_buffer_put() the last.
3723 mutex_lock(&event
->mmap_mutex
);
3724 ring_buffer_attach(event
, NULL
);
3725 mutex_unlock(&event
->mmap_mutex
);
3728 if (is_cgroup_event(event
))
3729 perf_detach_cgroup(event
);
3731 __free_event(event
);
3735 * Used to free events which have a known refcount of 1, such as in error paths
3736 * where the event isn't exposed yet and inherited events.
3738 static void free_event(struct perf_event
*event
)
3740 if (WARN(atomic_long_cmpxchg(&event
->refcount
, 1, 0) != 1,
3741 "unexpected event refcount: %ld; ptr=%p\n",
3742 atomic_long_read(&event
->refcount
), event
)) {
3743 /* leak to avoid use-after-free */
3751 * Remove user event from the owner task.
3753 static void perf_remove_from_owner(struct perf_event
*event
)
3755 struct task_struct
*owner
;
3758 owner
= ACCESS_ONCE(event
->owner
);
3760 * Matches the smp_wmb() in perf_event_exit_task(). If we observe
3761 * !owner it means the list deletion is complete and we can indeed
3762 * free this event, otherwise we need to serialize on
3763 * owner->perf_event_mutex.
3765 smp_read_barrier_depends();
3768 * Since delayed_put_task_struct() also drops the last
3769 * task reference we can safely take a new reference
3770 * while holding the rcu_read_lock().
3772 get_task_struct(owner
);
3778 * If we're here through perf_event_exit_task() we're already
3779 * holding ctx->mutex which would be an inversion wrt. the
3780 * normal lock order.
3782 * However we can safely take this lock because its the child
3785 mutex_lock_nested(&owner
->perf_event_mutex
, SINGLE_DEPTH_NESTING
);
3788 * We have to re-check the event->owner field, if it is cleared
3789 * we raced with perf_event_exit_task(), acquiring the mutex
3790 * ensured they're done, and we can proceed with freeing the
3794 list_del_init(&event
->owner_entry
);
3795 mutex_unlock(&owner
->perf_event_mutex
);
3796 put_task_struct(owner
);
3800 static void put_event(struct perf_event
*event
)
3802 struct perf_event_context
*ctx
;
3804 if (!atomic_long_dec_and_test(&event
->refcount
))
3807 if (!is_kernel_event(event
))
3808 perf_remove_from_owner(event
);
3811 * There are two ways this annotation is useful:
3813 * 1) there is a lock recursion from perf_event_exit_task
3814 * see the comment there.
3816 * 2) there is a lock-inversion with mmap_sem through
3817 * perf_read_group(), which takes faults while
3818 * holding ctx->mutex, however this is called after
3819 * the last filedesc died, so there is no possibility
3820 * to trigger the AB-BA case.
3822 ctx
= perf_event_ctx_lock_nested(event
, SINGLE_DEPTH_NESTING
);
3823 WARN_ON_ONCE(ctx
->parent_ctx
);
3824 perf_remove_from_context(event
, true);
3825 perf_event_ctx_unlock(event
, ctx
);
3830 int perf_event_release_kernel(struct perf_event
*event
)
3835 EXPORT_SYMBOL_GPL(perf_event_release_kernel
);
3838 * Called when the last reference to the file is gone.
3840 static int perf_release(struct inode
*inode
, struct file
*file
)
3842 put_event(file
->private_data
);
3847 * Remove all orphanes events from the context.
3849 static void orphans_remove_work(struct work_struct
*work
)
3851 struct perf_event_context
*ctx
;
3852 struct perf_event
*event
, *tmp
;
3854 ctx
= container_of(work
, struct perf_event_context
,
3855 orphans_remove
.work
);
3857 mutex_lock(&ctx
->mutex
);
3858 list_for_each_entry_safe(event
, tmp
, &ctx
->event_list
, event_entry
) {
3859 struct perf_event
*parent_event
= event
->parent
;
3861 if (!is_orphaned_child(event
))
3864 perf_remove_from_context(event
, true);
3866 mutex_lock(&parent_event
->child_mutex
);
3867 list_del_init(&event
->child_list
);
3868 mutex_unlock(&parent_event
->child_mutex
);
3871 put_event(parent_event
);
3874 raw_spin_lock_irq(&ctx
->lock
);
3875 ctx
->orphans_remove_sched
= false;
3876 raw_spin_unlock_irq(&ctx
->lock
);
3877 mutex_unlock(&ctx
->mutex
);
3882 u64
perf_event_read_value(struct perf_event
*event
, u64
*enabled
, u64
*running
)
3884 struct perf_event
*child
;
3890 mutex_lock(&event
->child_mutex
);
3892 (void)perf_event_read(event
, false);
3893 total
+= perf_event_count(event
);
3895 *enabled
+= event
->total_time_enabled
+
3896 atomic64_read(&event
->child_total_time_enabled
);
3897 *running
+= event
->total_time_running
+
3898 atomic64_read(&event
->child_total_time_running
);
3900 list_for_each_entry(child
, &event
->child_list
, child_list
) {
3901 (void)perf_event_read(child
, false);
3902 total
+= perf_event_count(child
);
3903 *enabled
+= child
->total_time_enabled
;
3904 *running
+= child
->total_time_running
;
3906 mutex_unlock(&event
->child_mutex
);
3910 EXPORT_SYMBOL_GPL(perf_event_read_value
);
3912 static int __perf_read_group_add(struct perf_event
*leader
,
3913 u64 read_format
, u64
*values
)
3915 struct perf_event
*sub
;
3916 int n
= 1; /* skip @nr */
3919 ret
= perf_event_read(leader
, true);
3924 * Since we co-schedule groups, {enabled,running} times of siblings
3925 * will be identical to those of the leader, so we only publish one
3928 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
3929 values
[n
++] += leader
->total_time_enabled
+
3930 atomic64_read(&leader
->child_total_time_enabled
);
3933 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
3934 values
[n
++] += leader
->total_time_running
+
3935 atomic64_read(&leader
->child_total_time_running
);
3939 * Write {count,id} tuples for every sibling.
3941 values
[n
++] += perf_event_count(leader
);
3942 if (read_format
& PERF_FORMAT_ID
)
3943 values
[n
++] = primary_event_id(leader
);
3945 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
3946 values
[n
++] += perf_event_count(sub
);
3947 if (read_format
& PERF_FORMAT_ID
)
3948 values
[n
++] = primary_event_id(sub
);
3954 static int perf_read_group(struct perf_event
*event
,
3955 u64 read_format
, char __user
*buf
)
3957 struct perf_event
*leader
= event
->group_leader
, *child
;
3958 struct perf_event_context
*ctx
= leader
->ctx
;
3962 lockdep_assert_held(&ctx
->mutex
);
3964 values
= kzalloc(event
->read_size
, GFP_KERNEL
);
3968 values
[0] = 1 + leader
->nr_siblings
;
3971 * By locking the child_mutex of the leader we effectively
3972 * lock the child list of all siblings.. XXX explain how.
3974 mutex_lock(&leader
->child_mutex
);
3976 ret
= __perf_read_group_add(leader
, read_format
, values
);
3980 list_for_each_entry(child
, &leader
->child_list
, child_list
) {
3981 ret
= __perf_read_group_add(child
, read_format
, values
);
3986 mutex_unlock(&leader
->child_mutex
);
3988 ret
= event
->read_size
;
3989 if (copy_to_user(buf
, values
, event
->read_size
))
3994 mutex_unlock(&leader
->child_mutex
);
4000 static int perf_read_one(struct perf_event
*event
,
4001 u64 read_format
, char __user
*buf
)
4003 u64 enabled
, running
;
4007 values
[n
++] = perf_event_read_value(event
, &enabled
, &running
);
4008 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
4009 values
[n
++] = enabled
;
4010 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
4011 values
[n
++] = running
;
4012 if (read_format
& PERF_FORMAT_ID
)
4013 values
[n
++] = primary_event_id(event
);
4015 if (copy_to_user(buf
, values
, n
* sizeof(u64
)))
4018 return n
* sizeof(u64
);
4021 static bool is_event_hup(struct perf_event
*event
)
4025 if (event
->state
!= PERF_EVENT_STATE_EXIT
)
4028 mutex_lock(&event
->child_mutex
);
4029 no_children
= list_empty(&event
->child_list
);
4030 mutex_unlock(&event
->child_mutex
);
4035 * Read the performance event - simple non blocking version for now
4038 __perf_read(struct perf_event
*event
, char __user
*buf
, size_t count
)
4040 u64 read_format
= event
->attr
.read_format
;
4044 * Return end-of-file for a read on a event that is in
4045 * error state (i.e. because it was pinned but it couldn't be
4046 * scheduled on to the CPU at some point).
4048 if (event
->state
== PERF_EVENT_STATE_ERROR
)
4051 if (count
< event
->read_size
)
4054 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4055 if (read_format
& PERF_FORMAT_GROUP
)
4056 ret
= perf_read_group(event
, read_format
, buf
);
4058 ret
= perf_read_one(event
, read_format
, buf
);
4064 perf_read(struct file
*file
, char __user
*buf
, size_t count
, loff_t
*ppos
)
4066 struct perf_event
*event
= file
->private_data
;
4067 struct perf_event_context
*ctx
;
4070 ctx
= perf_event_ctx_lock(event
);
4071 ret
= __perf_read(event
, buf
, count
);
4072 perf_event_ctx_unlock(event
, ctx
);
4077 static unsigned int perf_poll(struct file
*file
, poll_table
*wait
)
4079 struct perf_event
*event
= file
->private_data
;
4080 struct ring_buffer
*rb
;
4081 unsigned int events
= POLLHUP
;
4083 poll_wait(file
, &event
->waitq
, wait
);
4085 if (is_event_hup(event
))
4089 * Pin the event->rb by taking event->mmap_mutex; otherwise
4090 * perf_event_set_output() can swizzle our rb and make us miss wakeups.
4092 mutex_lock(&event
->mmap_mutex
);
4095 events
= atomic_xchg(&rb
->poll
, 0);
4096 mutex_unlock(&event
->mmap_mutex
);
4100 static void _perf_event_reset(struct perf_event
*event
)
4102 (void)perf_event_read(event
, false);
4103 local64_set(&event
->count
, 0);
4104 perf_event_update_userpage(event
);
4108 * Holding the top-level event's child_mutex means that any
4109 * descendant process that has inherited this event will block
4110 * in sync_child_event if it goes to exit, thus satisfying the
4111 * task existence requirements of perf_event_enable/disable.
4113 static void perf_event_for_each_child(struct perf_event
*event
,
4114 void (*func
)(struct perf_event
*))
4116 struct perf_event
*child
;
4118 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4120 mutex_lock(&event
->child_mutex
);
4122 list_for_each_entry(child
, &event
->child_list
, child_list
)
4124 mutex_unlock(&event
->child_mutex
);
4127 static void perf_event_for_each(struct perf_event
*event
,
4128 void (*func
)(struct perf_event
*))
4130 struct perf_event_context
*ctx
= event
->ctx
;
4131 struct perf_event
*sibling
;
4133 lockdep_assert_held(&ctx
->mutex
);
4135 event
= event
->group_leader
;
4137 perf_event_for_each_child(event
, func
);
4138 list_for_each_entry(sibling
, &event
->sibling_list
, group_entry
)
4139 perf_event_for_each_child(sibling
, func
);
4142 struct period_event
{
4143 struct perf_event
*event
;
4147 static int __perf_event_period(void *info
)
4149 struct period_event
*pe
= info
;
4150 struct perf_event
*event
= pe
->event
;
4151 struct perf_event_context
*ctx
= event
->ctx
;
4152 u64 value
= pe
->value
;
4155 raw_spin_lock(&ctx
->lock
);
4156 if (event
->attr
.freq
) {
4157 event
->attr
.sample_freq
= value
;
4159 event
->attr
.sample_period
= value
;
4160 event
->hw
.sample_period
= value
;
4163 active
= (event
->state
== PERF_EVENT_STATE_ACTIVE
);
4165 perf_pmu_disable(ctx
->pmu
);
4166 event
->pmu
->stop(event
, PERF_EF_UPDATE
);
4169 local64_set(&event
->hw
.period_left
, 0);
4172 event
->pmu
->start(event
, PERF_EF_RELOAD
);
4173 perf_pmu_enable(ctx
->pmu
);
4175 raw_spin_unlock(&ctx
->lock
);
4180 static int perf_event_period(struct perf_event
*event
, u64 __user
*arg
)
4182 struct period_event pe
= { .event
= event
, };
4183 struct perf_event_context
*ctx
= event
->ctx
;
4184 struct task_struct
*task
;
4187 if (!is_sampling_event(event
))
4190 if (copy_from_user(&value
, arg
, sizeof(value
)))
4196 if (event
->attr
.freq
&& value
> sysctl_perf_event_sample_rate
)
4203 cpu_function_call(event
->cpu
, __perf_event_period
, &pe
);
4208 if (!task_function_call(task
, __perf_event_period
, &pe
))
4211 raw_spin_lock_irq(&ctx
->lock
);
4212 if (ctx
->is_active
) {
4213 raw_spin_unlock_irq(&ctx
->lock
);
4218 __perf_event_period(&pe
);
4219 raw_spin_unlock_irq(&ctx
->lock
);
4224 static const struct file_operations perf_fops
;
4226 static inline int perf_fget_light(int fd
, struct fd
*p
)
4228 struct fd f
= fdget(fd
);
4232 if (f
.file
->f_op
!= &perf_fops
) {
4240 static int perf_event_set_output(struct perf_event
*event
,
4241 struct perf_event
*output_event
);
4242 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
);
4243 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
);
4245 static long _perf_ioctl(struct perf_event
*event
, unsigned int cmd
, unsigned long arg
)
4247 void (*func
)(struct perf_event
*);
4251 case PERF_EVENT_IOC_ENABLE
:
4252 func
= _perf_event_enable
;
4254 case PERF_EVENT_IOC_DISABLE
:
4255 func
= _perf_event_disable
;
4257 case PERF_EVENT_IOC_RESET
:
4258 func
= _perf_event_reset
;
4261 case PERF_EVENT_IOC_REFRESH
:
4262 return _perf_event_refresh(event
, arg
);
4264 case PERF_EVENT_IOC_PERIOD
:
4265 return perf_event_period(event
, (u64 __user
*)arg
);
4267 case PERF_EVENT_IOC_ID
:
4269 u64 id
= primary_event_id(event
);
4271 if (copy_to_user((void __user
*)arg
, &id
, sizeof(id
)))
4276 case PERF_EVENT_IOC_SET_OUTPUT
:
4280 struct perf_event
*output_event
;
4282 ret
= perf_fget_light(arg
, &output
);
4285 output_event
= output
.file
->private_data
;
4286 ret
= perf_event_set_output(event
, output_event
);
4289 ret
= perf_event_set_output(event
, NULL
);
4294 case PERF_EVENT_IOC_SET_FILTER
:
4295 return perf_event_set_filter(event
, (void __user
*)arg
);
4297 case PERF_EVENT_IOC_SET_BPF
:
4298 return perf_event_set_bpf_prog(event
, arg
);
4304 if (flags
& PERF_IOC_FLAG_GROUP
)
4305 perf_event_for_each(event
, func
);
4307 perf_event_for_each_child(event
, func
);
4312 static long perf_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
4314 struct perf_event
*event
= file
->private_data
;
4315 struct perf_event_context
*ctx
;
4318 ctx
= perf_event_ctx_lock(event
);
4319 ret
= _perf_ioctl(event
, cmd
, arg
);
4320 perf_event_ctx_unlock(event
, ctx
);
4325 #ifdef CONFIG_COMPAT
4326 static long perf_compat_ioctl(struct file
*file
, unsigned int cmd
,
4329 switch (_IOC_NR(cmd
)) {
4330 case _IOC_NR(PERF_EVENT_IOC_SET_FILTER
):
4331 case _IOC_NR(PERF_EVENT_IOC_ID
):
4332 /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
4333 if (_IOC_SIZE(cmd
) == sizeof(compat_uptr_t
)) {
4334 cmd
&= ~IOCSIZE_MASK
;
4335 cmd
|= sizeof(void *) << IOCSIZE_SHIFT
;
4339 return perf_ioctl(file
, cmd
, arg
);
4342 # define perf_compat_ioctl NULL
4345 int perf_event_task_enable(void)
4347 struct perf_event_context
*ctx
;
4348 struct perf_event
*event
;
4350 mutex_lock(¤t
->perf_event_mutex
);
4351 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4352 ctx
= perf_event_ctx_lock(event
);
4353 perf_event_for_each_child(event
, _perf_event_enable
);
4354 perf_event_ctx_unlock(event
, ctx
);
4356 mutex_unlock(¤t
->perf_event_mutex
);
4361 int perf_event_task_disable(void)
4363 struct perf_event_context
*ctx
;
4364 struct perf_event
*event
;
4366 mutex_lock(¤t
->perf_event_mutex
);
4367 list_for_each_entry(event
, ¤t
->perf_event_list
, owner_entry
) {
4368 ctx
= perf_event_ctx_lock(event
);
4369 perf_event_for_each_child(event
, _perf_event_disable
);
4370 perf_event_ctx_unlock(event
, ctx
);
4372 mutex_unlock(¤t
->perf_event_mutex
);
4377 static int perf_event_index(struct perf_event
*event
)
4379 if (event
->hw
.state
& PERF_HES_STOPPED
)
4382 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
4385 return event
->pmu
->event_idx(event
);
4388 static void calc_timer_values(struct perf_event
*event
,
4395 *now
= perf_clock();
4396 ctx_time
= event
->shadow_ctx_time
+ *now
;
4397 *enabled
= ctx_time
- event
->tstamp_enabled
;
4398 *running
= ctx_time
- event
->tstamp_running
;
4401 static void perf_event_init_userpage(struct perf_event
*event
)
4403 struct perf_event_mmap_page
*userpg
;
4404 struct ring_buffer
*rb
;
4407 rb
= rcu_dereference(event
->rb
);
4411 userpg
= rb
->user_page
;
4413 /* Allow new userspace to detect that bit 0 is deprecated */
4414 userpg
->cap_bit0_is_deprecated
= 1;
4415 userpg
->size
= offsetof(struct perf_event_mmap_page
, __reserved
);
4416 userpg
->data_offset
= PAGE_SIZE
;
4417 userpg
->data_size
= perf_data_size(rb
);
4423 void __weak
arch_perf_update_userpage(
4424 struct perf_event
*event
, struct perf_event_mmap_page
*userpg
, u64 now
)
4429 * Callers need to ensure there can be no nesting of this function, otherwise
4430 * the seqlock logic goes bad. We can not serialize this because the arch
4431 * code calls this from NMI context.
4433 void perf_event_update_userpage(struct perf_event
*event
)
4435 struct perf_event_mmap_page
*userpg
;
4436 struct ring_buffer
*rb
;
4437 u64 enabled
, running
, now
;
4440 rb
= rcu_dereference(event
->rb
);
4445 * compute total_time_enabled, total_time_running
4446 * based on snapshot values taken when the event
4447 * was last scheduled in.
4449 * we cannot simply called update_context_time()
4450 * because of locking issue as we can be called in
4453 calc_timer_values(event
, &now
, &enabled
, &running
);
4455 userpg
= rb
->user_page
;
4457 * Disable preemption so as to not let the corresponding user-space
4458 * spin too long if we get preempted.
4463 userpg
->index
= perf_event_index(event
);
4464 userpg
->offset
= perf_event_count(event
);
4466 userpg
->offset
-= local64_read(&event
->hw
.prev_count
);
4468 userpg
->time_enabled
= enabled
+
4469 atomic64_read(&event
->child_total_time_enabled
);
4471 userpg
->time_running
= running
+
4472 atomic64_read(&event
->child_total_time_running
);
4474 arch_perf_update_userpage(event
, userpg
, now
);
4483 static int perf_mmap_fault(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
4485 struct perf_event
*event
= vma
->vm_file
->private_data
;
4486 struct ring_buffer
*rb
;
4487 int ret
= VM_FAULT_SIGBUS
;
4489 if (vmf
->flags
& FAULT_FLAG_MKWRITE
) {
4490 if (vmf
->pgoff
== 0)
4496 rb
= rcu_dereference(event
->rb
);
4500 if (vmf
->pgoff
&& (vmf
->flags
& FAULT_FLAG_WRITE
))
4503 vmf
->page
= perf_mmap_to_page(rb
, vmf
->pgoff
);
4507 get_page(vmf
->page
);
4508 vmf
->page
->mapping
= vma
->vm_file
->f_mapping
;
4509 vmf
->page
->index
= vmf
->pgoff
;
4518 static void ring_buffer_attach(struct perf_event
*event
,
4519 struct ring_buffer
*rb
)
4521 struct ring_buffer
*old_rb
= NULL
;
4522 unsigned long flags
;
4526 * Should be impossible, we set this when removing
4527 * event->rb_entry and wait/clear when adding event->rb_entry.
4529 WARN_ON_ONCE(event
->rcu_pending
);
4532 spin_lock_irqsave(&old_rb
->event_lock
, flags
);
4533 list_del_rcu(&event
->rb_entry
);
4534 spin_unlock_irqrestore(&old_rb
->event_lock
, flags
);
4536 event
->rcu_batches
= get_state_synchronize_rcu();
4537 event
->rcu_pending
= 1;
4541 if (event
->rcu_pending
) {
4542 cond_synchronize_rcu(event
->rcu_batches
);
4543 event
->rcu_pending
= 0;
4546 spin_lock_irqsave(&rb
->event_lock
, flags
);
4547 list_add_rcu(&event
->rb_entry
, &rb
->event_list
);
4548 spin_unlock_irqrestore(&rb
->event_lock
, flags
);
4551 rcu_assign_pointer(event
->rb
, rb
);
4554 ring_buffer_put(old_rb
);
4556 * Since we detached before setting the new rb, so that we
4557 * could attach the new rb, we could have missed a wakeup.
4560 wake_up_all(&event
->waitq
);
4564 static void ring_buffer_wakeup(struct perf_event
*event
)
4566 struct ring_buffer
*rb
;
4569 rb
= rcu_dereference(event
->rb
);
4571 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
)
4572 wake_up_all(&event
->waitq
);
4577 struct ring_buffer
*ring_buffer_get(struct perf_event
*event
)
4579 struct ring_buffer
*rb
;
4582 rb
= rcu_dereference(event
->rb
);
4584 if (!atomic_inc_not_zero(&rb
->refcount
))
4592 void ring_buffer_put(struct ring_buffer
*rb
)
4594 if (!atomic_dec_and_test(&rb
->refcount
))
4597 WARN_ON_ONCE(!list_empty(&rb
->event_list
));
4599 call_rcu(&rb
->rcu_head
, rb_free_rcu
);
4602 static void perf_mmap_open(struct vm_area_struct
*vma
)
4604 struct perf_event
*event
= vma
->vm_file
->private_data
;
4606 atomic_inc(&event
->mmap_count
);
4607 atomic_inc(&event
->rb
->mmap_count
);
4610 atomic_inc(&event
->rb
->aux_mmap_count
);
4612 if (event
->pmu
->event_mapped
)
4613 event
->pmu
->event_mapped(event
);
4617 * A buffer can be mmap()ed multiple times; either directly through the same
4618 * event, or through other events by use of perf_event_set_output().
4620 * In order to undo the VM accounting done by perf_mmap() we need to destroy
4621 * the buffer here, where we still have a VM context. This means we need
4622 * to detach all events redirecting to us.
4624 static void perf_mmap_close(struct vm_area_struct
*vma
)
4626 struct perf_event
*event
= vma
->vm_file
->private_data
;
4628 struct ring_buffer
*rb
= ring_buffer_get(event
);
4629 struct user_struct
*mmap_user
= rb
->mmap_user
;
4630 int mmap_locked
= rb
->mmap_locked
;
4631 unsigned long size
= perf_data_size(rb
);
4633 if (event
->pmu
->event_unmapped
)
4634 event
->pmu
->event_unmapped(event
);
4637 * rb->aux_mmap_count will always drop before rb->mmap_count and
4638 * event->mmap_count, so it is ok to use event->mmap_mutex to
4639 * serialize with perf_mmap here.
4641 if (rb_has_aux(rb
) && vma
->vm_pgoff
== rb
->aux_pgoff
&&
4642 atomic_dec_and_mutex_lock(&rb
->aux_mmap_count
, &event
->mmap_mutex
)) {
4643 atomic_long_sub(rb
->aux_nr_pages
, &mmap_user
->locked_vm
);
4644 vma
->vm_mm
->pinned_vm
-= rb
->aux_mmap_locked
;
4647 mutex_unlock(&event
->mmap_mutex
);
4650 atomic_dec(&rb
->mmap_count
);
4652 if (!atomic_dec_and_mutex_lock(&event
->mmap_count
, &event
->mmap_mutex
))
4655 ring_buffer_attach(event
, NULL
);
4656 mutex_unlock(&event
->mmap_mutex
);
4658 /* If there's still other mmap()s of this buffer, we're done. */
4659 if (atomic_read(&rb
->mmap_count
))
4663 * No other mmap()s, detach from all other events that might redirect
4664 * into the now unreachable buffer. Somewhat complicated by the
4665 * fact that rb::event_lock otherwise nests inside mmap_mutex.
4669 list_for_each_entry_rcu(event
, &rb
->event_list
, rb_entry
) {
4670 if (!atomic_long_inc_not_zero(&event
->refcount
)) {
4672 * This event is en-route to free_event() which will
4673 * detach it and remove it from the list.
4679 mutex_lock(&event
->mmap_mutex
);
4681 * Check we didn't race with perf_event_set_output() which can
4682 * swizzle the rb from under us while we were waiting to
4683 * acquire mmap_mutex.
4685 * If we find a different rb; ignore this event, a next
4686 * iteration will no longer find it on the list. We have to
4687 * still restart the iteration to make sure we're not now
4688 * iterating the wrong list.
4690 if (event
->rb
== rb
)
4691 ring_buffer_attach(event
, NULL
);
4693 mutex_unlock(&event
->mmap_mutex
);
4697 * Restart the iteration; either we're on the wrong list or
4698 * destroyed its integrity by doing a deletion.
4705 * It could be there's still a few 0-ref events on the list; they'll
4706 * get cleaned up by free_event() -- they'll also still have their
4707 * ref on the rb and will free it whenever they are done with it.
4709 * Aside from that, this buffer is 'fully' detached and unmapped,
4710 * undo the VM accounting.
4713 atomic_long_sub((size
>> PAGE_SHIFT
) + 1, &mmap_user
->locked_vm
);
4714 vma
->vm_mm
->pinned_vm
-= mmap_locked
;
4715 free_uid(mmap_user
);
4718 ring_buffer_put(rb
); /* could be last */
4721 static const struct vm_operations_struct perf_mmap_vmops
= {
4722 .open
= perf_mmap_open
,
4723 .close
= perf_mmap_close
, /* non mergable */
4724 .fault
= perf_mmap_fault
,
4725 .page_mkwrite
= perf_mmap_fault
,
4728 static int perf_mmap(struct file
*file
, struct vm_area_struct
*vma
)
4730 struct perf_event
*event
= file
->private_data
;
4731 unsigned long user_locked
, user_lock_limit
;
4732 struct user_struct
*user
= current_user();
4733 unsigned long locked
, lock_limit
;
4734 struct ring_buffer
*rb
= NULL
;
4735 unsigned long vma_size
;
4736 unsigned long nr_pages
;
4737 long user_extra
= 0, extra
= 0;
4738 int ret
= 0, flags
= 0;
4741 * Don't allow mmap() of inherited per-task counters. This would
4742 * create a performance issue due to all children writing to the
4745 if (event
->cpu
== -1 && event
->attr
.inherit
)
4748 if (!(vma
->vm_flags
& VM_SHARED
))
4751 vma_size
= vma
->vm_end
- vma
->vm_start
;
4753 if (vma
->vm_pgoff
== 0) {
4754 nr_pages
= (vma_size
/ PAGE_SIZE
) - 1;
4757 * AUX area mapping: if rb->aux_nr_pages != 0, it's already
4758 * mapped, all subsequent mappings should have the same size
4759 * and offset. Must be above the normal perf buffer.
4761 u64 aux_offset
, aux_size
;
4766 nr_pages
= vma_size
/ PAGE_SIZE
;
4768 mutex_lock(&event
->mmap_mutex
);
4775 aux_offset
= ACCESS_ONCE(rb
->user_page
->aux_offset
);
4776 aux_size
= ACCESS_ONCE(rb
->user_page
->aux_size
);
4778 if (aux_offset
< perf_data_size(rb
) + PAGE_SIZE
)
4781 if (aux_offset
!= vma
->vm_pgoff
<< PAGE_SHIFT
)
4784 /* already mapped with a different offset */
4785 if (rb_has_aux(rb
) && rb
->aux_pgoff
!= vma
->vm_pgoff
)
4788 if (aux_size
!= vma_size
|| aux_size
!= nr_pages
* PAGE_SIZE
)
4791 /* already mapped with a different size */
4792 if (rb_has_aux(rb
) && rb
->aux_nr_pages
!= nr_pages
)
4795 if (!is_power_of_2(nr_pages
))
4798 if (!atomic_inc_not_zero(&rb
->mmap_count
))
4801 if (rb_has_aux(rb
)) {
4802 atomic_inc(&rb
->aux_mmap_count
);
4807 atomic_set(&rb
->aux_mmap_count
, 1);
4808 user_extra
= nr_pages
;
4814 * If we have rb pages ensure they're a power-of-two number, so we
4815 * can do bitmasks instead of modulo.
4817 if (nr_pages
!= 0 && !is_power_of_2(nr_pages
))
4820 if (vma_size
!= PAGE_SIZE
* (1 + nr_pages
))
4823 WARN_ON_ONCE(event
->ctx
->parent_ctx
);
4825 mutex_lock(&event
->mmap_mutex
);
4827 if (event
->rb
->nr_pages
!= nr_pages
) {
4832 if (!atomic_inc_not_zero(&event
->rb
->mmap_count
)) {
4834 * Raced against perf_mmap_close() through
4835 * perf_event_set_output(). Try again, hope for better
4838 mutex_unlock(&event
->mmap_mutex
);
4845 user_extra
= nr_pages
+ 1;
4848 user_lock_limit
= sysctl_perf_event_mlock
>> (PAGE_SHIFT
- 10);
4851 * Increase the limit linearly with more CPUs:
4853 user_lock_limit
*= num_online_cpus();
4855 user_locked
= atomic_long_read(&user
->locked_vm
) + user_extra
;
4857 if (user_locked
> user_lock_limit
)
4858 extra
= user_locked
- user_lock_limit
;
4860 lock_limit
= rlimit(RLIMIT_MEMLOCK
);
4861 lock_limit
>>= PAGE_SHIFT
;
4862 locked
= vma
->vm_mm
->pinned_vm
+ extra
;
4864 if ((locked
> lock_limit
) && perf_paranoid_tracepoint_raw() &&
4865 !capable(CAP_IPC_LOCK
)) {
4870 WARN_ON(!rb
&& event
->rb
);
4872 if (vma
->vm_flags
& VM_WRITE
)
4873 flags
|= RING_BUFFER_WRITABLE
;
4876 rb
= rb_alloc(nr_pages
,
4877 event
->attr
.watermark
? event
->attr
.wakeup_watermark
: 0,
4885 atomic_set(&rb
->mmap_count
, 1);
4886 rb
->mmap_user
= get_current_user();
4887 rb
->mmap_locked
= extra
;
4889 ring_buffer_attach(event
, rb
);
4891 perf_event_init_userpage(event
);
4892 perf_event_update_userpage(event
);
4894 ret
= rb_alloc_aux(rb
, event
, vma
->vm_pgoff
, nr_pages
,
4895 event
->attr
.aux_watermark
, flags
);
4897 rb
->aux_mmap_locked
= extra
;
4902 atomic_long_add(user_extra
, &user
->locked_vm
);
4903 vma
->vm_mm
->pinned_vm
+= extra
;
4905 atomic_inc(&event
->mmap_count
);
4907 atomic_dec(&rb
->mmap_count
);
4910 mutex_unlock(&event
->mmap_mutex
);
4913 * Since pinned accounting is per vm we cannot allow fork() to copy our
4916 vma
->vm_flags
|= VM_DONTCOPY
| VM_DONTEXPAND
| VM_DONTDUMP
;
4917 vma
->vm_ops
= &perf_mmap_vmops
;
4919 if (event
->pmu
->event_mapped
)
4920 event
->pmu
->event_mapped(event
);
4925 static int perf_fasync(int fd
, struct file
*filp
, int on
)
4927 struct inode
*inode
= file_inode(filp
);
4928 struct perf_event
*event
= filp
->private_data
;
4931 mutex_lock(&inode
->i_mutex
);
4932 retval
= fasync_helper(fd
, filp
, on
, &event
->fasync
);
4933 mutex_unlock(&inode
->i_mutex
);
4941 static const struct file_operations perf_fops
= {
4942 .llseek
= no_llseek
,
4943 .release
= perf_release
,
4946 .unlocked_ioctl
= perf_ioctl
,
4947 .compat_ioctl
= perf_compat_ioctl
,
4949 .fasync
= perf_fasync
,
4955 * If there's data, ensure we set the poll() state and publish everything
4956 * to user-space before waking everybody up.
4959 static inline struct fasync_struct
**perf_event_fasync(struct perf_event
*event
)
4961 /* only the parent has fasync state */
4963 event
= event
->parent
;
4964 return &event
->fasync
;
4967 void perf_event_wakeup(struct perf_event
*event
)
4969 ring_buffer_wakeup(event
);
4971 if (event
->pending_kill
) {
4972 kill_fasync(perf_event_fasync(event
), SIGIO
, event
->pending_kill
);
4973 event
->pending_kill
= 0;
4977 static void perf_pending_event(struct irq_work
*entry
)
4979 struct perf_event
*event
= container_of(entry
,
4980 struct perf_event
, pending
);
4983 rctx
= perf_swevent_get_recursion_context();
4985 * If we 'fail' here, that's OK, it means recursion is already disabled
4986 * and we won't recurse 'further'.
4989 if (event
->pending_disable
) {
4990 event
->pending_disable
= 0;
4991 __perf_event_disable(event
);
4994 if (event
->pending_wakeup
) {
4995 event
->pending_wakeup
= 0;
4996 perf_event_wakeup(event
);
5000 perf_swevent_put_recursion_context(rctx
);
5004 * We assume there is only KVM supporting the callbacks.
5005 * Later on, we might change it to a list if there is
5006 * another virtualization implementation supporting the callbacks.
5008 struct perf_guest_info_callbacks
*perf_guest_cbs
;
5010 int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5012 perf_guest_cbs
= cbs
;
5015 EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks
);
5017 int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks
*cbs
)
5019 perf_guest_cbs
= NULL
;
5022 EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks
);
5025 perf_output_sample_regs(struct perf_output_handle
*handle
,
5026 struct pt_regs
*regs
, u64 mask
)
5030 for_each_set_bit(bit
, (const unsigned long *) &mask
,
5031 sizeof(mask
) * BITS_PER_BYTE
) {
5034 val
= perf_reg_value(regs
, bit
);
5035 perf_output_put(handle
, val
);
5039 static void perf_sample_regs_user(struct perf_regs
*regs_user
,
5040 struct pt_regs
*regs
,
5041 struct pt_regs
*regs_user_copy
)
5043 if (user_mode(regs
)) {
5044 regs_user
->abi
= perf_reg_abi(current
);
5045 regs_user
->regs
= regs
;
5046 } else if (current
->mm
) {
5047 perf_get_regs_user(regs_user
, regs
, regs_user_copy
);
5049 regs_user
->abi
= PERF_SAMPLE_REGS_ABI_NONE
;
5050 regs_user
->regs
= NULL
;
5054 static void perf_sample_regs_intr(struct perf_regs
*regs_intr
,
5055 struct pt_regs
*regs
)
5057 regs_intr
->regs
= regs
;
5058 regs_intr
->abi
= perf_reg_abi(current
);
5063 * Get remaining task size from user stack pointer.
5065 * It'd be better to take stack vma map and limit this more
5066 * precisly, but there's no way to get it safely under interrupt,
5067 * so using TASK_SIZE as limit.
5069 static u64
perf_ustack_task_size(struct pt_regs
*regs
)
5071 unsigned long addr
= perf_user_stack_pointer(regs
);
5073 if (!addr
|| addr
>= TASK_SIZE
)
5076 return TASK_SIZE
- addr
;
5080 perf_sample_ustack_size(u16 stack_size
, u16 header_size
,
5081 struct pt_regs
*regs
)
5085 /* No regs, no stack pointer, no dump. */
5090 * Check if we fit in with the requested stack size into the:
5092 * If we don't, we limit the size to the TASK_SIZE.
5094 * - remaining sample size
5095 * If we don't, we customize the stack size to
5096 * fit in to the remaining sample size.
5099 task_size
= min((u64
) USHRT_MAX
, perf_ustack_task_size(regs
));
5100 stack_size
= min(stack_size
, (u16
) task_size
);
5102 /* Current header size plus static size and dynamic size. */
5103 header_size
+= 2 * sizeof(u64
);
5105 /* Do we fit in with the current stack dump size? */
5106 if ((u16
) (header_size
+ stack_size
) < header_size
) {
5108 * If we overflow the maximum size for the sample,
5109 * we customize the stack dump size to fit in.
5111 stack_size
= USHRT_MAX
- header_size
- sizeof(u64
);
5112 stack_size
= round_up(stack_size
, sizeof(u64
));
5119 perf_output_sample_ustack(struct perf_output_handle
*handle
, u64 dump_size
,
5120 struct pt_regs
*regs
)
5122 /* Case of a kernel thread, nothing to dump */
5125 perf_output_put(handle
, size
);
5134 * - the size requested by user or the best one we can fit
5135 * in to the sample max size
5137 * - user stack dump data
5139 * - the actual dumped size
5143 perf_output_put(handle
, dump_size
);
5146 sp
= perf_user_stack_pointer(regs
);
5147 rem
= __output_copy_user(handle
, (void *) sp
, dump_size
);
5148 dyn_size
= dump_size
- rem
;
5150 perf_output_skip(handle
, rem
);
5153 perf_output_put(handle
, dyn_size
);
5157 static void __perf_event_header__init_id(struct perf_event_header
*header
,
5158 struct perf_sample_data
*data
,
5159 struct perf_event
*event
)
5161 u64 sample_type
= event
->attr
.sample_type
;
5163 data
->type
= sample_type
;
5164 header
->size
+= event
->id_header_size
;
5166 if (sample_type
& PERF_SAMPLE_TID
) {
5167 /* namespace issues */
5168 data
->tid_entry
.pid
= perf_event_pid(event
, current
);
5169 data
->tid_entry
.tid
= perf_event_tid(event
, current
);
5172 if (sample_type
& PERF_SAMPLE_TIME
)
5173 data
->time
= perf_event_clock(event
);
5175 if (sample_type
& (PERF_SAMPLE_ID
| PERF_SAMPLE_IDENTIFIER
))
5176 data
->id
= primary_event_id(event
);
5178 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5179 data
->stream_id
= event
->id
;
5181 if (sample_type
& PERF_SAMPLE_CPU
) {
5182 data
->cpu_entry
.cpu
= raw_smp_processor_id();
5183 data
->cpu_entry
.reserved
= 0;
5187 void perf_event_header__init_id(struct perf_event_header
*header
,
5188 struct perf_sample_data
*data
,
5189 struct perf_event
*event
)
5191 if (event
->attr
.sample_id_all
)
5192 __perf_event_header__init_id(header
, data
, event
);
5195 static void __perf_event__output_id_sample(struct perf_output_handle
*handle
,
5196 struct perf_sample_data
*data
)
5198 u64 sample_type
= data
->type
;
5200 if (sample_type
& PERF_SAMPLE_TID
)
5201 perf_output_put(handle
, data
->tid_entry
);
5203 if (sample_type
& PERF_SAMPLE_TIME
)
5204 perf_output_put(handle
, data
->time
);
5206 if (sample_type
& PERF_SAMPLE_ID
)
5207 perf_output_put(handle
, data
->id
);
5209 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5210 perf_output_put(handle
, data
->stream_id
);
5212 if (sample_type
& PERF_SAMPLE_CPU
)
5213 perf_output_put(handle
, data
->cpu_entry
);
5215 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5216 perf_output_put(handle
, data
->id
);
5219 void perf_event__output_id_sample(struct perf_event
*event
,
5220 struct perf_output_handle
*handle
,
5221 struct perf_sample_data
*sample
)
5223 if (event
->attr
.sample_id_all
)
5224 __perf_event__output_id_sample(handle
, sample
);
5227 static void perf_output_read_one(struct perf_output_handle
*handle
,
5228 struct perf_event
*event
,
5229 u64 enabled
, u64 running
)
5231 u64 read_format
= event
->attr
.read_format
;
5235 values
[n
++] = perf_event_count(event
);
5236 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
) {
5237 values
[n
++] = enabled
+
5238 atomic64_read(&event
->child_total_time_enabled
);
5240 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
) {
5241 values
[n
++] = running
+
5242 atomic64_read(&event
->child_total_time_running
);
5244 if (read_format
& PERF_FORMAT_ID
)
5245 values
[n
++] = primary_event_id(event
);
5247 __output_copy(handle
, values
, n
* sizeof(u64
));
5251 * XXX PERF_FORMAT_GROUP vs inherited events seems difficult.
5253 static void perf_output_read_group(struct perf_output_handle
*handle
,
5254 struct perf_event
*event
,
5255 u64 enabled
, u64 running
)
5257 struct perf_event
*leader
= event
->group_leader
, *sub
;
5258 u64 read_format
= event
->attr
.read_format
;
5262 values
[n
++] = 1 + leader
->nr_siblings
;
5264 if (read_format
& PERF_FORMAT_TOTAL_TIME_ENABLED
)
5265 values
[n
++] = enabled
;
5267 if (read_format
& PERF_FORMAT_TOTAL_TIME_RUNNING
)
5268 values
[n
++] = running
;
5270 if (leader
!= event
)
5271 leader
->pmu
->read(leader
);
5273 values
[n
++] = perf_event_count(leader
);
5274 if (read_format
& PERF_FORMAT_ID
)
5275 values
[n
++] = primary_event_id(leader
);
5277 __output_copy(handle
, values
, n
* sizeof(u64
));
5279 list_for_each_entry(sub
, &leader
->sibling_list
, group_entry
) {
5282 if ((sub
!= event
) &&
5283 (sub
->state
== PERF_EVENT_STATE_ACTIVE
))
5284 sub
->pmu
->read(sub
);
5286 values
[n
++] = perf_event_count(sub
);
5287 if (read_format
& PERF_FORMAT_ID
)
5288 values
[n
++] = primary_event_id(sub
);
5290 __output_copy(handle
, values
, n
* sizeof(u64
));
5294 #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\
5295 PERF_FORMAT_TOTAL_TIME_RUNNING)
5297 static void perf_output_read(struct perf_output_handle
*handle
,
5298 struct perf_event
*event
)
5300 u64 enabled
= 0, running
= 0, now
;
5301 u64 read_format
= event
->attr
.read_format
;
5304 * compute total_time_enabled, total_time_running
5305 * based on snapshot values taken when the event
5306 * was last scheduled in.
5308 * we cannot simply called update_context_time()
5309 * because of locking issue as we are called in
5312 if (read_format
& PERF_FORMAT_TOTAL_TIMES
)
5313 calc_timer_values(event
, &now
, &enabled
, &running
);
5315 if (event
->attr
.read_format
& PERF_FORMAT_GROUP
)
5316 perf_output_read_group(handle
, event
, enabled
, running
);
5318 perf_output_read_one(handle
, event
, enabled
, running
);
5321 void perf_output_sample(struct perf_output_handle
*handle
,
5322 struct perf_event_header
*header
,
5323 struct perf_sample_data
*data
,
5324 struct perf_event
*event
)
5326 u64 sample_type
= data
->type
;
5328 perf_output_put(handle
, *header
);
5330 if (sample_type
& PERF_SAMPLE_IDENTIFIER
)
5331 perf_output_put(handle
, data
->id
);
5333 if (sample_type
& PERF_SAMPLE_IP
)
5334 perf_output_put(handle
, data
->ip
);
5336 if (sample_type
& PERF_SAMPLE_TID
)
5337 perf_output_put(handle
, data
->tid_entry
);
5339 if (sample_type
& PERF_SAMPLE_TIME
)
5340 perf_output_put(handle
, data
->time
);
5342 if (sample_type
& PERF_SAMPLE_ADDR
)
5343 perf_output_put(handle
, data
->addr
);
5345 if (sample_type
& PERF_SAMPLE_ID
)
5346 perf_output_put(handle
, data
->id
);
5348 if (sample_type
& PERF_SAMPLE_STREAM_ID
)
5349 perf_output_put(handle
, data
->stream_id
);
5351 if (sample_type
& PERF_SAMPLE_CPU
)
5352 perf_output_put(handle
, data
->cpu_entry
);
5354 if (sample_type
& PERF_SAMPLE_PERIOD
)
5355 perf_output_put(handle
, data
->period
);
5357 if (sample_type
& PERF_SAMPLE_READ
)
5358 perf_output_read(handle
, event
);
5360 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5361 if (data
->callchain
) {
5364 if (data
->callchain
)
5365 size
+= data
->callchain
->nr
;
5367 size
*= sizeof(u64
);
5369 __output_copy(handle
, data
->callchain
, size
);
5372 perf_output_put(handle
, nr
);
5376 if (sample_type
& PERF_SAMPLE_RAW
) {
5378 u32 raw_size
= data
->raw
->size
;
5379 u32 real_size
= round_up(raw_size
+ sizeof(u32
),
5380 sizeof(u64
)) - sizeof(u32
);
5383 perf_output_put(handle
, real_size
);
5384 __output_copy(handle
, data
->raw
->data
, raw_size
);
5385 if (real_size
- raw_size
)
5386 __output_copy(handle
, &zero
, real_size
- raw_size
);
5392 .size
= sizeof(u32
),
5395 perf_output_put(handle
, raw
);
5399 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5400 if (data
->br_stack
) {
5403 size
= data
->br_stack
->nr
5404 * sizeof(struct perf_branch_entry
);
5406 perf_output_put(handle
, data
->br_stack
->nr
);
5407 perf_output_copy(handle
, data
->br_stack
->entries
, size
);
5410 * we always store at least the value of nr
5413 perf_output_put(handle
, nr
);
5417 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5418 u64 abi
= data
->regs_user
.abi
;
5421 * If there are no regs to dump, notice it through
5422 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5424 perf_output_put(handle
, abi
);
5427 u64 mask
= event
->attr
.sample_regs_user
;
5428 perf_output_sample_regs(handle
,
5429 data
->regs_user
.regs
,
5434 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5435 perf_output_sample_ustack(handle
,
5436 data
->stack_user_size
,
5437 data
->regs_user
.regs
);
5440 if (sample_type
& PERF_SAMPLE_WEIGHT
)
5441 perf_output_put(handle
, data
->weight
);
5443 if (sample_type
& PERF_SAMPLE_DATA_SRC
)
5444 perf_output_put(handle
, data
->data_src
.val
);
5446 if (sample_type
& PERF_SAMPLE_TRANSACTION
)
5447 perf_output_put(handle
, data
->txn
);
5449 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5450 u64 abi
= data
->regs_intr
.abi
;
5452 * If there are no regs to dump, notice it through
5453 * first u64 being zero (PERF_SAMPLE_REGS_ABI_NONE).
5455 perf_output_put(handle
, abi
);
5458 u64 mask
= event
->attr
.sample_regs_intr
;
5460 perf_output_sample_regs(handle
,
5461 data
->regs_intr
.regs
,
5466 if (!event
->attr
.watermark
) {
5467 int wakeup_events
= event
->attr
.wakeup_events
;
5469 if (wakeup_events
) {
5470 struct ring_buffer
*rb
= handle
->rb
;
5471 int events
= local_inc_return(&rb
->events
);
5473 if (events
>= wakeup_events
) {
5474 local_sub(wakeup_events
, &rb
->events
);
5475 local_inc(&rb
->wakeup
);
5481 void perf_prepare_sample(struct perf_event_header
*header
,
5482 struct perf_sample_data
*data
,
5483 struct perf_event
*event
,
5484 struct pt_regs
*regs
)
5486 u64 sample_type
= event
->attr
.sample_type
;
5488 header
->type
= PERF_RECORD_SAMPLE
;
5489 header
->size
= sizeof(*header
) + event
->header_size
;
5492 header
->misc
|= perf_misc_flags(regs
);
5494 __perf_event_header__init_id(header
, data
, event
);
5496 if (sample_type
& PERF_SAMPLE_IP
)
5497 data
->ip
= perf_instruction_pointer(regs
);
5499 if (sample_type
& PERF_SAMPLE_CALLCHAIN
) {
5502 data
->callchain
= perf_callchain(event
, regs
);
5504 if (data
->callchain
)
5505 size
+= data
->callchain
->nr
;
5507 header
->size
+= size
* sizeof(u64
);
5510 if (sample_type
& PERF_SAMPLE_RAW
) {
5511 int size
= sizeof(u32
);
5514 size
+= data
->raw
->size
;
5516 size
+= sizeof(u32
);
5518 header
->size
+= round_up(size
, sizeof(u64
));
5521 if (sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
5522 int size
= sizeof(u64
); /* nr */
5523 if (data
->br_stack
) {
5524 size
+= data
->br_stack
->nr
5525 * sizeof(struct perf_branch_entry
);
5527 header
->size
+= size
;
5530 if (sample_type
& (PERF_SAMPLE_REGS_USER
| PERF_SAMPLE_STACK_USER
))
5531 perf_sample_regs_user(&data
->regs_user
, regs
,
5532 &data
->regs_user_copy
);
5534 if (sample_type
& PERF_SAMPLE_REGS_USER
) {
5535 /* regs dump ABI info */
5536 int size
= sizeof(u64
);
5538 if (data
->regs_user
.regs
) {
5539 u64 mask
= event
->attr
.sample_regs_user
;
5540 size
+= hweight64(mask
) * sizeof(u64
);
5543 header
->size
+= size
;
5546 if (sample_type
& PERF_SAMPLE_STACK_USER
) {
5548 * Either we need PERF_SAMPLE_STACK_USER bit to be allways
5549 * processed as the last one or have additional check added
5550 * in case new sample type is added, because we could eat
5551 * up the rest of the sample size.
5553 u16 stack_size
= event
->attr
.sample_stack_user
;
5554 u16 size
= sizeof(u64
);
5556 stack_size
= perf_sample_ustack_size(stack_size
, header
->size
,
5557 data
->regs_user
.regs
);
5560 * If there is something to dump, add space for the dump
5561 * itself and for the field that tells the dynamic size,
5562 * which is how many have been actually dumped.
5565 size
+= sizeof(u64
) + stack_size
;
5567 data
->stack_user_size
= stack_size
;
5568 header
->size
+= size
;
5571 if (sample_type
& PERF_SAMPLE_REGS_INTR
) {
5572 /* regs dump ABI info */
5573 int size
= sizeof(u64
);
5575 perf_sample_regs_intr(&data
->regs_intr
, regs
);
5577 if (data
->regs_intr
.regs
) {
5578 u64 mask
= event
->attr
.sample_regs_intr
;
5580 size
+= hweight64(mask
) * sizeof(u64
);
5583 header
->size
+= size
;
5587 void perf_event_output(struct perf_event
*event
,
5588 struct perf_sample_data
*data
,
5589 struct pt_regs
*regs
)
5591 struct perf_output_handle handle
;
5592 struct perf_event_header header
;
5594 /* protect the callchain buffers */
5597 perf_prepare_sample(&header
, data
, event
, regs
);
5599 if (perf_output_begin(&handle
, event
, header
.size
))
5602 perf_output_sample(&handle
, &header
, data
, event
);
5604 perf_output_end(&handle
);
5614 struct perf_read_event
{
5615 struct perf_event_header header
;
5622 perf_event_read_event(struct perf_event
*event
,
5623 struct task_struct
*task
)
5625 struct perf_output_handle handle
;
5626 struct perf_sample_data sample
;
5627 struct perf_read_event read_event
= {
5629 .type
= PERF_RECORD_READ
,
5631 .size
= sizeof(read_event
) + event
->read_size
,
5633 .pid
= perf_event_pid(event
, task
),
5634 .tid
= perf_event_tid(event
, task
),
5638 perf_event_header__init_id(&read_event
.header
, &sample
, event
);
5639 ret
= perf_output_begin(&handle
, event
, read_event
.header
.size
);
5643 perf_output_put(&handle
, read_event
);
5644 perf_output_read(&handle
, event
);
5645 perf_event__output_id_sample(event
, &handle
, &sample
);
5647 perf_output_end(&handle
);
5650 typedef void (perf_event_aux_output_cb
)(struct perf_event
*event
, void *data
);
5653 perf_event_aux_ctx(struct perf_event_context
*ctx
,
5654 perf_event_aux_output_cb output
,
5657 struct perf_event
*event
;
5659 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
5660 if (event
->state
< PERF_EVENT_STATE_INACTIVE
)
5662 if (!event_filter_match(event
))
5664 output(event
, data
);
5669 perf_event_aux(perf_event_aux_output_cb output
, void *data
,
5670 struct perf_event_context
*task_ctx
)
5672 struct perf_cpu_context
*cpuctx
;
5673 struct perf_event_context
*ctx
;
5678 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
5679 cpuctx
= get_cpu_ptr(pmu
->pmu_cpu_context
);
5680 if (cpuctx
->unique_pmu
!= pmu
)
5682 perf_event_aux_ctx(&cpuctx
->ctx
, output
, data
);
5685 ctxn
= pmu
->task_ctx_nr
;
5688 ctx
= rcu_dereference(current
->perf_event_ctxp
[ctxn
]);
5690 perf_event_aux_ctx(ctx
, output
, data
);
5692 put_cpu_ptr(pmu
->pmu_cpu_context
);
5697 perf_event_aux_ctx(task_ctx
, output
, data
);
5704 * task tracking -- fork/exit
5706 * enabled by: attr.comm | attr.mmap | attr.mmap2 | attr.mmap_data | attr.task
5709 struct perf_task_event
{
5710 struct task_struct
*task
;
5711 struct perf_event_context
*task_ctx
;
5714 struct perf_event_header header
;
5724 static int perf_event_task_match(struct perf_event
*event
)
5726 return event
->attr
.comm
|| event
->attr
.mmap
||
5727 event
->attr
.mmap2
|| event
->attr
.mmap_data
||
5731 static void perf_event_task_output(struct perf_event
*event
,
5734 struct perf_task_event
*task_event
= data
;
5735 struct perf_output_handle handle
;
5736 struct perf_sample_data sample
;
5737 struct task_struct
*task
= task_event
->task
;
5738 int ret
, size
= task_event
->event_id
.header
.size
;
5740 if (!perf_event_task_match(event
))
5743 perf_event_header__init_id(&task_event
->event_id
.header
, &sample
, event
);
5745 ret
= perf_output_begin(&handle
, event
,
5746 task_event
->event_id
.header
.size
);
5750 task_event
->event_id
.pid
= perf_event_pid(event
, task
);
5751 task_event
->event_id
.ppid
= perf_event_pid(event
, current
);
5753 task_event
->event_id
.tid
= perf_event_tid(event
, task
);
5754 task_event
->event_id
.ptid
= perf_event_tid(event
, current
);
5756 task_event
->event_id
.time
= perf_event_clock(event
);
5758 perf_output_put(&handle
, task_event
->event_id
);
5760 perf_event__output_id_sample(event
, &handle
, &sample
);
5762 perf_output_end(&handle
);
5764 task_event
->event_id
.header
.size
= size
;
5767 static void perf_event_task(struct task_struct
*task
,
5768 struct perf_event_context
*task_ctx
,
5771 struct perf_task_event task_event
;
5773 if (!atomic_read(&nr_comm_events
) &&
5774 !atomic_read(&nr_mmap_events
) &&
5775 !atomic_read(&nr_task_events
))
5778 task_event
= (struct perf_task_event
){
5780 .task_ctx
= task_ctx
,
5783 .type
= new ? PERF_RECORD_FORK
: PERF_RECORD_EXIT
,
5785 .size
= sizeof(task_event
.event_id
),
5795 perf_event_aux(perf_event_task_output
,
5800 void perf_event_fork(struct task_struct
*task
)
5802 perf_event_task(task
, NULL
, 1);
5809 struct perf_comm_event
{
5810 struct task_struct
*task
;
5815 struct perf_event_header header
;
5822 static int perf_event_comm_match(struct perf_event
*event
)
5824 return event
->attr
.comm
;
5827 static void perf_event_comm_output(struct perf_event
*event
,
5830 struct perf_comm_event
*comm_event
= data
;
5831 struct perf_output_handle handle
;
5832 struct perf_sample_data sample
;
5833 int size
= comm_event
->event_id
.header
.size
;
5836 if (!perf_event_comm_match(event
))
5839 perf_event_header__init_id(&comm_event
->event_id
.header
, &sample
, event
);
5840 ret
= perf_output_begin(&handle
, event
,
5841 comm_event
->event_id
.header
.size
);
5846 comm_event
->event_id
.pid
= perf_event_pid(event
, comm_event
->task
);
5847 comm_event
->event_id
.tid
= perf_event_tid(event
, comm_event
->task
);
5849 perf_output_put(&handle
, comm_event
->event_id
);
5850 __output_copy(&handle
, comm_event
->comm
,
5851 comm_event
->comm_size
);
5853 perf_event__output_id_sample(event
, &handle
, &sample
);
5855 perf_output_end(&handle
);
5857 comm_event
->event_id
.header
.size
= size
;
5860 static void perf_event_comm_event(struct perf_comm_event
*comm_event
)
5862 char comm
[TASK_COMM_LEN
];
5865 memset(comm
, 0, sizeof(comm
));
5866 strlcpy(comm
, comm_event
->task
->comm
, sizeof(comm
));
5867 size
= ALIGN(strlen(comm
)+1, sizeof(u64
));
5869 comm_event
->comm
= comm
;
5870 comm_event
->comm_size
= size
;
5872 comm_event
->event_id
.header
.size
= sizeof(comm_event
->event_id
) + size
;
5874 perf_event_aux(perf_event_comm_output
,
5879 void perf_event_comm(struct task_struct
*task
, bool exec
)
5881 struct perf_comm_event comm_event
;
5883 if (!atomic_read(&nr_comm_events
))
5886 comm_event
= (struct perf_comm_event
){
5892 .type
= PERF_RECORD_COMM
,
5893 .misc
= exec
? PERF_RECORD_MISC_COMM_EXEC
: 0,
5901 perf_event_comm_event(&comm_event
);
5908 struct perf_mmap_event
{
5909 struct vm_area_struct
*vma
;
5911 const char *file_name
;
5919 struct perf_event_header header
;
5929 static int perf_event_mmap_match(struct perf_event
*event
,
5932 struct perf_mmap_event
*mmap_event
= data
;
5933 struct vm_area_struct
*vma
= mmap_event
->vma
;
5934 int executable
= vma
->vm_flags
& VM_EXEC
;
5936 return (!executable
&& event
->attr
.mmap_data
) ||
5937 (executable
&& (event
->attr
.mmap
|| event
->attr
.mmap2
));
5940 static void perf_event_mmap_output(struct perf_event
*event
,
5943 struct perf_mmap_event
*mmap_event
= data
;
5944 struct perf_output_handle handle
;
5945 struct perf_sample_data sample
;
5946 int size
= mmap_event
->event_id
.header
.size
;
5949 if (!perf_event_mmap_match(event
, data
))
5952 if (event
->attr
.mmap2
) {
5953 mmap_event
->event_id
.header
.type
= PERF_RECORD_MMAP2
;
5954 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->maj
);
5955 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->min
);
5956 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino
);
5957 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->ino_generation
);
5958 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->prot
);
5959 mmap_event
->event_id
.header
.size
+= sizeof(mmap_event
->flags
);
5962 perf_event_header__init_id(&mmap_event
->event_id
.header
, &sample
, event
);
5963 ret
= perf_output_begin(&handle
, event
,
5964 mmap_event
->event_id
.header
.size
);
5968 mmap_event
->event_id
.pid
= perf_event_pid(event
, current
);
5969 mmap_event
->event_id
.tid
= perf_event_tid(event
, current
);
5971 perf_output_put(&handle
, mmap_event
->event_id
);
5973 if (event
->attr
.mmap2
) {
5974 perf_output_put(&handle
, mmap_event
->maj
);
5975 perf_output_put(&handle
, mmap_event
->min
);
5976 perf_output_put(&handle
, mmap_event
->ino
);
5977 perf_output_put(&handle
, mmap_event
->ino_generation
);
5978 perf_output_put(&handle
, mmap_event
->prot
);
5979 perf_output_put(&handle
, mmap_event
->flags
);
5982 __output_copy(&handle
, mmap_event
->file_name
,
5983 mmap_event
->file_size
);
5985 perf_event__output_id_sample(event
, &handle
, &sample
);
5987 perf_output_end(&handle
);
5989 mmap_event
->event_id
.header
.size
= size
;
5992 static void perf_event_mmap_event(struct perf_mmap_event
*mmap_event
)
5994 struct vm_area_struct
*vma
= mmap_event
->vma
;
5995 struct file
*file
= vma
->vm_file
;
5996 int maj
= 0, min
= 0;
5997 u64 ino
= 0, gen
= 0;
5998 u32 prot
= 0, flags
= 0;
6005 struct inode
*inode
;
6008 buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
6014 * d_path() works from the end of the rb backwards, so we
6015 * need to add enough zero bytes after the string to handle
6016 * the 64bit alignment we do later.
6018 name
= file_path(file
, buf
, PATH_MAX
- sizeof(u64
));
6023 inode
= file_inode(vma
->vm_file
);
6024 dev
= inode
->i_sb
->s_dev
;
6026 gen
= inode
->i_generation
;
6030 if (vma
->vm_flags
& VM_READ
)
6032 if (vma
->vm_flags
& VM_WRITE
)
6034 if (vma
->vm_flags
& VM_EXEC
)
6037 if (vma
->vm_flags
& VM_MAYSHARE
)
6040 flags
= MAP_PRIVATE
;
6042 if (vma
->vm_flags
& VM_DENYWRITE
)
6043 flags
|= MAP_DENYWRITE
;
6044 if (vma
->vm_flags
& VM_MAYEXEC
)
6045 flags
|= MAP_EXECUTABLE
;
6046 if (vma
->vm_flags
& VM_LOCKED
)
6047 flags
|= MAP_LOCKED
;
6048 if (vma
->vm_flags
& VM_HUGETLB
)
6049 flags
|= MAP_HUGETLB
;
6053 if (vma
->vm_ops
&& vma
->vm_ops
->name
) {
6054 name
= (char *) vma
->vm_ops
->name(vma
);
6059 name
= (char *)arch_vma_name(vma
);
6063 if (vma
->vm_start
<= vma
->vm_mm
->start_brk
&&
6064 vma
->vm_end
>= vma
->vm_mm
->brk
) {
6068 if (vma
->vm_start
<= vma
->vm_mm
->start_stack
&&
6069 vma
->vm_end
>= vma
->vm_mm
->start_stack
) {
6079 strlcpy(tmp
, name
, sizeof(tmp
));
6083 * Since our buffer works in 8 byte units we need to align our string
6084 * size to a multiple of 8. However, we must guarantee the tail end is
6085 * zero'd out to avoid leaking random bits to userspace.
6087 size
= strlen(name
)+1;
6088 while (!IS_ALIGNED(size
, sizeof(u64
)))
6089 name
[size
++] = '\0';
6091 mmap_event
->file_name
= name
;
6092 mmap_event
->file_size
= size
;
6093 mmap_event
->maj
= maj
;
6094 mmap_event
->min
= min
;
6095 mmap_event
->ino
= ino
;
6096 mmap_event
->ino_generation
= gen
;
6097 mmap_event
->prot
= prot
;
6098 mmap_event
->flags
= flags
;
6100 if (!(vma
->vm_flags
& VM_EXEC
))
6101 mmap_event
->event_id
.header
.misc
|= PERF_RECORD_MISC_MMAP_DATA
;
6103 mmap_event
->event_id
.header
.size
= sizeof(mmap_event
->event_id
) + size
;
6105 perf_event_aux(perf_event_mmap_output
,
6112 void perf_event_mmap(struct vm_area_struct
*vma
)
6114 struct perf_mmap_event mmap_event
;
6116 if (!atomic_read(&nr_mmap_events
))
6119 mmap_event
= (struct perf_mmap_event
){
6125 .type
= PERF_RECORD_MMAP
,
6126 .misc
= PERF_RECORD_MISC_USER
,
6131 .start
= vma
->vm_start
,
6132 .len
= vma
->vm_end
- vma
->vm_start
,
6133 .pgoff
= (u64
)vma
->vm_pgoff
<< PAGE_SHIFT
,
6135 /* .maj (attr_mmap2 only) */
6136 /* .min (attr_mmap2 only) */
6137 /* .ino (attr_mmap2 only) */
6138 /* .ino_generation (attr_mmap2 only) */
6139 /* .prot (attr_mmap2 only) */
6140 /* .flags (attr_mmap2 only) */
6143 perf_event_mmap_event(&mmap_event
);
6146 void perf_event_aux_event(struct perf_event
*event
, unsigned long head
,
6147 unsigned long size
, u64 flags
)
6149 struct perf_output_handle handle
;
6150 struct perf_sample_data sample
;
6151 struct perf_aux_event
{
6152 struct perf_event_header header
;
6158 .type
= PERF_RECORD_AUX
,
6160 .size
= sizeof(rec
),
6168 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6169 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6174 perf_output_put(&handle
, rec
);
6175 perf_event__output_id_sample(event
, &handle
, &sample
);
6177 perf_output_end(&handle
);
6181 * Lost/dropped samples logging
6183 void perf_log_lost_samples(struct perf_event
*event
, u64 lost
)
6185 struct perf_output_handle handle
;
6186 struct perf_sample_data sample
;
6190 struct perf_event_header header
;
6192 } lost_samples_event
= {
6194 .type
= PERF_RECORD_LOST_SAMPLES
,
6196 .size
= sizeof(lost_samples_event
),
6201 perf_event_header__init_id(&lost_samples_event
.header
, &sample
, event
);
6203 ret
= perf_output_begin(&handle
, event
,
6204 lost_samples_event
.header
.size
);
6208 perf_output_put(&handle
, lost_samples_event
);
6209 perf_event__output_id_sample(event
, &handle
, &sample
);
6210 perf_output_end(&handle
);
6214 * context_switch tracking
6217 struct perf_switch_event
{
6218 struct task_struct
*task
;
6219 struct task_struct
*next_prev
;
6222 struct perf_event_header header
;
6228 static int perf_event_switch_match(struct perf_event
*event
)
6230 return event
->attr
.context_switch
;
6233 static void perf_event_switch_output(struct perf_event
*event
, void *data
)
6235 struct perf_switch_event
*se
= data
;
6236 struct perf_output_handle handle
;
6237 struct perf_sample_data sample
;
6240 if (!perf_event_switch_match(event
))
6243 /* Only CPU-wide events are allowed to see next/prev pid/tid */
6244 if (event
->ctx
->task
) {
6245 se
->event_id
.header
.type
= PERF_RECORD_SWITCH
;
6246 se
->event_id
.header
.size
= sizeof(se
->event_id
.header
);
6248 se
->event_id
.header
.type
= PERF_RECORD_SWITCH_CPU_WIDE
;
6249 se
->event_id
.header
.size
= sizeof(se
->event_id
);
6250 se
->event_id
.next_prev_pid
=
6251 perf_event_pid(event
, se
->next_prev
);
6252 se
->event_id
.next_prev_tid
=
6253 perf_event_tid(event
, se
->next_prev
);
6256 perf_event_header__init_id(&se
->event_id
.header
, &sample
, event
);
6258 ret
= perf_output_begin(&handle
, event
, se
->event_id
.header
.size
);
6262 if (event
->ctx
->task
)
6263 perf_output_put(&handle
, se
->event_id
.header
);
6265 perf_output_put(&handle
, se
->event_id
);
6267 perf_event__output_id_sample(event
, &handle
, &sample
);
6269 perf_output_end(&handle
);
6272 static void perf_event_switch(struct task_struct
*task
,
6273 struct task_struct
*next_prev
, bool sched_in
)
6275 struct perf_switch_event switch_event
;
6277 /* N.B. caller checks nr_switch_events != 0 */
6279 switch_event
= (struct perf_switch_event
){
6281 .next_prev
= next_prev
,
6285 .misc
= sched_in
? 0 : PERF_RECORD_MISC_SWITCH_OUT
,
6288 /* .next_prev_pid */
6289 /* .next_prev_tid */
6293 perf_event_aux(perf_event_switch_output
,
6299 * IRQ throttle logging
6302 static void perf_log_throttle(struct perf_event
*event
, int enable
)
6304 struct perf_output_handle handle
;
6305 struct perf_sample_data sample
;
6309 struct perf_event_header header
;
6313 } throttle_event
= {
6315 .type
= PERF_RECORD_THROTTLE
,
6317 .size
= sizeof(throttle_event
),
6319 .time
= perf_event_clock(event
),
6320 .id
= primary_event_id(event
),
6321 .stream_id
= event
->id
,
6325 throttle_event
.header
.type
= PERF_RECORD_UNTHROTTLE
;
6327 perf_event_header__init_id(&throttle_event
.header
, &sample
, event
);
6329 ret
= perf_output_begin(&handle
, event
,
6330 throttle_event
.header
.size
);
6334 perf_output_put(&handle
, throttle_event
);
6335 perf_event__output_id_sample(event
, &handle
, &sample
);
6336 perf_output_end(&handle
);
6339 static void perf_log_itrace_start(struct perf_event
*event
)
6341 struct perf_output_handle handle
;
6342 struct perf_sample_data sample
;
6343 struct perf_aux_event
{
6344 struct perf_event_header header
;
6351 event
= event
->parent
;
6353 if (!(event
->pmu
->capabilities
& PERF_PMU_CAP_ITRACE
) ||
6354 event
->hw
.itrace_started
)
6357 rec
.header
.type
= PERF_RECORD_ITRACE_START
;
6358 rec
.header
.misc
= 0;
6359 rec
.header
.size
= sizeof(rec
);
6360 rec
.pid
= perf_event_pid(event
, current
);
6361 rec
.tid
= perf_event_tid(event
, current
);
6363 perf_event_header__init_id(&rec
.header
, &sample
, event
);
6364 ret
= perf_output_begin(&handle
, event
, rec
.header
.size
);
6369 perf_output_put(&handle
, rec
);
6370 perf_event__output_id_sample(event
, &handle
, &sample
);
6372 perf_output_end(&handle
);
6376 * Generic event overflow handling, sampling.
6379 static int __perf_event_overflow(struct perf_event
*event
,
6380 int throttle
, struct perf_sample_data
*data
,
6381 struct pt_regs
*regs
)
6383 int events
= atomic_read(&event
->event_limit
);
6384 struct hw_perf_event
*hwc
= &event
->hw
;
6389 * Non-sampling counters might still use the PMI to fold short
6390 * hardware counters, ignore those.
6392 if (unlikely(!is_sampling_event(event
)))
6395 seq
= __this_cpu_read(perf_throttled_seq
);
6396 if (seq
!= hwc
->interrupts_seq
) {
6397 hwc
->interrupts_seq
= seq
;
6398 hwc
->interrupts
= 1;
6401 if (unlikely(throttle
6402 && hwc
->interrupts
>= max_samples_per_tick
)) {
6403 __this_cpu_inc(perf_throttled_count
);
6404 hwc
->interrupts
= MAX_INTERRUPTS
;
6405 perf_log_throttle(event
, 0);
6406 tick_nohz_full_kick();
6411 if (event
->attr
.freq
) {
6412 u64 now
= perf_clock();
6413 s64 delta
= now
- hwc
->freq_time_stamp
;
6415 hwc
->freq_time_stamp
= now
;
6417 if (delta
> 0 && delta
< 2*TICK_NSEC
)
6418 perf_adjust_period(event
, delta
, hwc
->last_period
, true);
6422 * XXX event_limit might not quite work as expected on inherited
6426 event
->pending_kill
= POLL_IN
;
6427 if (events
&& atomic_dec_and_test(&event
->event_limit
)) {
6429 event
->pending_kill
= POLL_HUP
;
6430 event
->pending_disable
= 1;
6431 irq_work_queue(&event
->pending
);
6434 if (event
->overflow_handler
)
6435 event
->overflow_handler(event
, data
, regs
);
6437 perf_event_output(event
, data
, regs
);
6439 if (*perf_event_fasync(event
) && event
->pending_kill
) {
6440 event
->pending_wakeup
= 1;
6441 irq_work_queue(&event
->pending
);
6447 int perf_event_overflow(struct perf_event
*event
,
6448 struct perf_sample_data
*data
,
6449 struct pt_regs
*regs
)
6451 return __perf_event_overflow(event
, 1, data
, regs
);
6455 * Generic software event infrastructure
6458 struct swevent_htable
{
6459 struct swevent_hlist
*swevent_hlist
;
6460 struct mutex hlist_mutex
;
6463 /* Recursion avoidance in each contexts */
6464 int recursion
[PERF_NR_CONTEXTS
];
6466 /* Keeps track of cpu being initialized/exited */
6470 static DEFINE_PER_CPU(struct swevent_htable
, swevent_htable
);
6473 * We directly increment event->count and keep a second value in
6474 * event->hw.period_left to count intervals. This period event
6475 * is kept in the range [-sample_period, 0] so that we can use the
6479 u64
perf_swevent_set_period(struct perf_event
*event
)
6481 struct hw_perf_event
*hwc
= &event
->hw
;
6482 u64 period
= hwc
->last_period
;
6486 hwc
->last_period
= hwc
->sample_period
;
6489 old
= val
= local64_read(&hwc
->period_left
);
6493 nr
= div64_u64(period
+ val
, period
);
6494 offset
= nr
* period
;
6496 if (local64_cmpxchg(&hwc
->period_left
, old
, val
) != old
)
6502 static void perf_swevent_overflow(struct perf_event
*event
, u64 overflow
,
6503 struct perf_sample_data
*data
,
6504 struct pt_regs
*regs
)
6506 struct hw_perf_event
*hwc
= &event
->hw
;
6510 overflow
= perf_swevent_set_period(event
);
6512 if (hwc
->interrupts
== MAX_INTERRUPTS
)
6515 for (; overflow
; overflow
--) {
6516 if (__perf_event_overflow(event
, throttle
,
6519 * We inhibit the overflow from happening when
6520 * hwc->interrupts == MAX_INTERRUPTS.
6528 static void perf_swevent_event(struct perf_event
*event
, u64 nr
,
6529 struct perf_sample_data
*data
,
6530 struct pt_regs
*regs
)
6532 struct hw_perf_event
*hwc
= &event
->hw
;
6534 local64_add(nr
, &event
->count
);
6539 if (!is_sampling_event(event
))
6542 if ((event
->attr
.sample_type
& PERF_SAMPLE_PERIOD
) && !event
->attr
.freq
) {
6544 return perf_swevent_overflow(event
, 1, data
, regs
);
6546 data
->period
= event
->hw
.last_period
;
6548 if (nr
== 1 && hwc
->sample_period
== 1 && !event
->attr
.freq
)
6549 return perf_swevent_overflow(event
, 1, data
, regs
);
6551 if (local64_add_negative(nr
, &hwc
->period_left
))
6554 perf_swevent_overflow(event
, 0, data
, regs
);
6557 static int perf_exclude_event(struct perf_event
*event
,
6558 struct pt_regs
*regs
)
6560 if (event
->hw
.state
& PERF_HES_STOPPED
)
6564 if (event
->attr
.exclude_user
&& user_mode(regs
))
6567 if (event
->attr
.exclude_kernel
&& !user_mode(regs
))
6574 static int perf_swevent_match(struct perf_event
*event
,
6575 enum perf_type_id type
,
6577 struct perf_sample_data
*data
,
6578 struct pt_regs
*regs
)
6580 if (event
->attr
.type
!= type
)
6583 if (event
->attr
.config
!= event_id
)
6586 if (perf_exclude_event(event
, regs
))
6592 static inline u64
swevent_hash(u64 type
, u32 event_id
)
6594 u64 val
= event_id
| (type
<< 32);
6596 return hash_64(val
, SWEVENT_HLIST_BITS
);
6599 static inline struct hlist_head
*
6600 __find_swevent_head(struct swevent_hlist
*hlist
, u64 type
, u32 event_id
)
6602 u64 hash
= swevent_hash(type
, event_id
);
6604 return &hlist
->heads
[hash
];
6607 /* For the read side: events when they trigger */
6608 static inline struct hlist_head
*
6609 find_swevent_head_rcu(struct swevent_htable
*swhash
, u64 type
, u32 event_id
)
6611 struct swevent_hlist
*hlist
;
6613 hlist
= rcu_dereference(swhash
->swevent_hlist
);
6617 return __find_swevent_head(hlist
, type
, event_id
);
6620 /* For the event head insertion and removal in the hlist */
6621 static inline struct hlist_head
*
6622 find_swevent_head(struct swevent_htable
*swhash
, struct perf_event
*event
)
6624 struct swevent_hlist
*hlist
;
6625 u32 event_id
= event
->attr
.config
;
6626 u64 type
= event
->attr
.type
;
6629 * Event scheduling is always serialized against hlist allocation
6630 * and release. Which makes the protected version suitable here.
6631 * The context lock guarantees that.
6633 hlist
= rcu_dereference_protected(swhash
->swevent_hlist
,
6634 lockdep_is_held(&event
->ctx
->lock
));
6638 return __find_swevent_head(hlist
, type
, event_id
);
6641 static void do_perf_sw_event(enum perf_type_id type
, u32 event_id
,
6643 struct perf_sample_data
*data
,
6644 struct pt_regs
*regs
)
6646 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6647 struct perf_event
*event
;
6648 struct hlist_head
*head
;
6651 head
= find_swevent_head_rcu(swhash
, type
, event_id
);
6655 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6656 if (perf_swevent_match(event
, type
, event_id
, data
, regs
))
6657 perf_swevent_event(event
, nr
, data
, regs
);
6663 DEFINE_PER_CPU(struct pt_regs
, __perf_regs
[4]);
6665 int perf_swevent_get_recursion_context(void)
6667 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6669 return get_recursion_context(swhash
->recursion
);
6671 EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context
);
6673 inline void perf_swevent_put_recursion_context(int rctx
)
6675 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6677 put_recursion_context(swhash
->recursion
, rctx
);
6680 void ___perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6682 struct perf_sample_data data
;
6684 if (WARN_ON_ONCE(!regs
))
6687 perf_sample_data_init(&data
, addr
, 0);
6688 do_perf_sw_event(PERF_TYPE_SOFTWARE
, event_id
, nr
, &data
, regs
);
6691 void __perf_sw_event(u32 event_id
, u64 nr
, struct pt_regs
*regs
, u64 addr
)
6695 preempt_disable_notrace();
6696 rctx
= perf_swevent_get_recursion_context();
6697 if (unlikely(rctx
< 0))
6700 ___perf_sw_event(event_id
, nr
, regs
, addr
);
6702 perf_swevent_put_recursion_context(rctx
);
6704 preempt_enable_notrace();
6707 static void perf_swevent_read(struct perf_event
*event
)
6711 static int perf_swevent_add(struct perf_event
*event
, int flags
)
6713 struct swevent_htable
*swhash
= this_cpu_ptr(&swevent_htable
);
6714 struct hw_perf_event
*hwc
= &event
->hw
;
6715 struct hlist_head
*head
;
6717 if (is_sampling_event(event
)) {
6718 hwc
->last_period
= hwc
->sample_period
;
6719 perf_swevent_set_period(event
);
6722 hwc
->state
= !(flags
& PERF_EF_START
);
6724 head
= find_swevent_head(swhash
, event
);
6727 * We can race with cpu hotplug code. Do not
6728 * WARN if the cpu just got unplugged.
6730 WARN_ON_ONCE(swhash
->online
);
6734 hlist_add_head_rcu(&event
->hlist_entry
, head
);
6735 perf_event_update_userpage(event
);
6740 static void perf_swevent_del(struct perf_event
*event
, int flags
)
6742 hlist_del_rcu(&event
->hlist_entry
);
6745 static void perf_swevent_start(struct perf_event
*event
, int flags
)
6747 event
->hw
.state
= 0;
6750 static void perf_swevent_stop(struct perf_event
*event
, int flags
)
6752 event
->hw
.state
= PERF_HES_STOPPED
;
6755 /* Deref the hlist from the update side */
6756 static inline struct swevent_hlist
*
6757 swevent_hlist_deref(struct swevent_htable
*swhash
)
6759 return rcu_dereference_protected(swhash
->swevent_hlist
,
6760 lockdep_is_held(&swhash
->hlist_mutex
));
6763 static void swevent_hlist_release(struct swevent_htable
*swhash
)
6765 struct swevent_hlist
*hlist
= swevent_hlist_deref(swhash
);
6770 RCU_INIT_POINTER(swhash
->swevent_hlist
, NULL
);
6771 kfree_rcu(hlist
, rcu_head
);
6774 static void swevent_hlist_put_cpu(struct perf_event
*event
, int cpu
)
6776 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6778 mutex_lock(&swhash
->hlist_mutex
);
6780 if (!--swhash
->hlist_refcount
)
6781 swevent_hlist_release(swhash
);
6783 mutex_unlock(&swhash
->hlist_mutex
);
6786 static void swevent_hlist_put(struct perf_event
*event
)
6790 for_each_possible_cpu(cpu
)
6791 swevent_hlist_put_cpu(event
, cpu
);
6794 static int swevent_hlist_get_cpu(struct perf_event
*event
, int cpu
)
6796 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
6799 mutex_lock(&swhash
->hlist_mutex
);
6801 if (!swevent_hlist_deref(swhash
) && cpu_online(cpu
)) {
6802 struct swevent_hlist
*hlist
;
6804 hlist
= kzalloc(sizeof(*hlist
), GFP_KERNEL
);
6809 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
6811 swhash
->hlist_refcount
++;
6813 mutex_unlock(&swhash
->hlist_mutex
);
6818 static int swevent_hlist_get(struct perf_event
*event
)
6821 int cpu
, failed_cpu
;
6824 for_each_possible_cpu(cpu
) {
6825 err
= swevent_hlist_get_cpu(event
, cpu
);
6835 for_each_possible_cpu(cpu
) {
6836 if (cpu
== failed_cpu
)
6838 swevent_hlist_put_cpu(event
, cpu
);
6845 struct static_key perf_swevent_enabled
[PERF_COUNT_SW_MAX
];
6847 static void sw_perf_event_destroy(struct perf_event
*event
)
6849 u64 event_id
= event
->attr
.config
;
6851 WARN_ON(event
->parent
);
6853 static_key_slow_dec(&perf_swevent_enabled
[event_id
]);
6854 swevent_hlist_put(event
);
6857 static int perf_swevent_init(struct perf_event
*event
)
6859 u64 event_id
= event
->attr
.config
;
6861 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
6865 * no branch sampling for software events
6867 if (has_branch_stack(event
))
6871 case PERF_COUNT_SW_CPU_CLOCK
:
6872 case PERF_COUNT_SW_TASK_CLOCK
:
6879 if (event_id
>= PERF_COUNT_SW_MAX
)
6882 if (!event
->parent
) {
6885 err
= swevent_hlist_get(event
);
6889 static_key_slow_inc(&perf_swevent_enabled
[event_id
]);
6890 event
->destroy
= sw_perf_event_destroy
;
6896 static struct pmu perf_swevent
= {
6897 .task_ctx_nr
= perf_sw_context
,
6899 .capabilities
= PERF_PMU_CAP_NO_NMI
,
6901 .event_init
= perf_swevent_init
,
6902 .add
= perf_swevent_add
,
6903 .del
= perf_swevent_del
,
6904 .start
= perf_swevent_start
,
6905 .stop
= perf_swevent_stop
,
6906 .read
= perf_swevent_read
,
6909 #ifdef CONFIG_EVENT_TRACING
6911 static int perf_tp_filter_match(struct perf_event
*event
,
6912 struct perf_sample_data
*data
)
6914 void *record
= data
->raw
->data
;
6916 if (likely(!event
->filter
) || filter_match_preds(event
->filter
, record
))
6921 static int perf_tp_event_match(struct perf_event
*event
,
6922 struct perf_sample_data
*data
,
6923 struct pt_regs
*regs
)
6925 if (event
->hw
.state
& PERF_HES_STOPPED
)
6928 * All tracepoints are from kernel-space.
6930 if (event
->attr
.exclude_kernel
)
6933 if (!perf_tp_filter_match(event
, data
))
6939 void perf_tp_event(u64 addr
, u64 count
, void *record
, int entry_size
,
6940 struct pt_regs
*regs
, struct hlist_head
*head
, int rctx
,
6941 struct task_struct
*task
)
6943 struct perf_sample_data data
;
6944 struct perf_event
*event
;
6946 struct perf_raw_record raw
= {
6951 perf_sample_data_init(&data
, addr
, 0);
6954 hlist_for_each_entry_rcu(event
, head
, hlist_entry
) {
6955 if (perf_tp_event_match(event
, &data
, regs
))
6956 perf_swevent_event(event
, count
, &data
, regs
);
6960 * If we got specified a target task, also iterate its context and
6961 * deliver this event there too.
6963 if (task
&& task
!= current
) {
6964 struct perf_event_context
*ctx
;
6965 struct trace_entry
*entry
= record
;
6968 ctx
= rcu_dereference(task
->perf_event_ctxp
[perf_sw_context
]);
6972 list_for_each_entry_rcu(event
, &ctx
->event_list
, event_entry
) {
6973 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
6975 if (event
->attr
.config
!= entry
->type
)
6977 if (perf_tp_event_match(event
, &data
, regs
))
6978 perf_swevent_event(event
, count
, &data
, regs
);
6984 perf_swevent_put_recursion_context(rctx
);
6986 EXPORT_SYMBOL_GPL(perf_tp_event
);
6988 static void tp_perf_event_destroy(struct perf_event
*event
)
6990 perf_trace_destroy(event
);
6993 static int perf_tp_event_init(struct perf_event
*event
)
6997 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7001 * no branch sampling for tracepoint events
7003 if (has_branch_stack(event
))
7006 err
= perf_trace_init(event
);
7010 event
->destroy
= tp_perf_event_destroy
;
7015 static struct pmu perf_tracepoint
= {
7016 .task_ctx_nr
= perf_sw_context
,
7018 .event_init
= perf_tp_event_init
,
7019 .add
= perf_trace_add
,
7020 .del
= perf_trace_del
,
7021 .start
= perf_swevent_start
,
7022 .stop
= perf_swevent_stop
,
7023 .read
= perf_swevent_read
,
7026 static inline void perf_tp_register(void)
7028 perf_pmu_register(&perf_tracepoint
, "tracepoint", PERF_TYPE_TRACEPOINT
);
7031 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7036 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7039 filter_str
= strndup_user(arg
, PAGE_SIZE
);
7040 if (IS_ERR(filter_str
))
7041 return PTR_ERR(filter_str
);
7043 ret
= ftrace_profile_set_filter(event
, event
->attr
.config
, filter_str
);
7049 static void perf_event_free_filter(struct perf_event
*event
)
7051 ftrace_profile_free_filter(event
);
7054 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7056 struct bpf_prog
*prog
;
7058 if (event
->attr
.type
!= PERF_TYPE_TRACEPOINT
)
7061 if (event
->tp_event
->prog
)
7064 if (!(event
->tp_event
->flags
& TRACE_EVENT_FL_UKPROBE
))
7065 /* bpf programs can only be attached to u/kprobes */
7068 prog
= bpf_prog_get(prog_fd
);
7070 return PTR_ERR(prog
);
7072 if (prog
->type
!= BPF_PROG_TYPE_KPROBE
) {
7073 /* valid fd, but invalid bpf program type */
7078 event
->tp_event
->prog
= prog
;
7083 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7085 struct bpf_prog
*prog
;
7087 if (!event
->tp_event
)
7090 prog
= event
->tp_event
->prog
;
7092 event
->tp_event
->prog
= NULL
;
7099 static inline void perf_tp_register(void)
7103 static int perf_event_set_filter(struct perf_event
*event
, void __user
*arg
)
7108 static void perf_event_free_filter(struct perf_event
*event
)
7112 static int perf_event_set_bpf_prog(struct perf_event
*event
, u32 prog_fd
)
7117 static void perf_event_free_bpf_prog(struct perf_event
*event
)
7120 #endif /* CONFIG_EVENT_TRACING */
7122 #ifdef CONFIG_HAVE_HW_BREAKPOINT
7123 void perf_bp_event(struct perf_event
*bp
, void *data
)
7125 struct perf_sample_data sample
;
7126 struct pt_regs
*regs
= data
;
7128 perf_sample_data_init(&sample
, bp
->attr
.bp_addr
, 0);
7130 if (!bp
->hw
.state
&& !perf_exclude_event(bp
, regs
))
7131 perf_swevent_event(bp
, 1, &sample
, regs
);
7136 * hrtimer based swevent callback
7139 static enum hrtimer_restart
perf_swevent_hrtimer(struct hrtimer
*hrtimer
)
7141 enum hrtimer_restart ret
= HRTIMER_RESTART
;
7142 struct perf_sample_data data
;
7143 struct pt_regs
*regs
;
7144 struct perf_event
*event
;
7147 event
= container_of(hrtimer
, struct perf_event
, hw
.hrtimer
);
7149 if (event
->state
!= PERF_EVENT_STATE_ACTIVE
)
7150 return HRTIMER_NORESTART
;
7152 event
->pmu
->read(event
);
7154 perf_sample_data_init(&data
, 0, event
->hw
.last_period
);
7155 regs
= get_irq_regs();
7157 if (regs
&& !perf_exclude_event(event
, regs
)) {
7158 if (!(event
->attr
.exclude_idle
&& is_idle_task(current
)))
7159 if (__perf_event_overflow(event
, 1, &data
, regs
))
7160 ret
= HRTIMER_NORESTART
;
7163 period
= max_t(u64
, 10000, event
->hw
.sample_period
);
7164 hrtimer_forward_now(hrtimer
, ns_to_ktime(period
));
7169 static void perf_swevent_start_hrtimer(struct perf_event
*event
)
7171 struct hw_perf_event
*hwc
= &event
->hw
;
7174 if (!is_sampling_event(event
))
7177 period
= local64_read(&hwc
->period_left
);
7182 local64_set(&hwc
->period_left
, 0);
7184 period
= max_t(u64
, 10000, hwc
->sample_period
);
7186 hrtimer_start(&hwc
->hrtimer
, ns_to_ktime(period
),
7187 HRTIMER_MODE_REL_PINNED
);
7190 static void perf_swevent_cancel_hrtimer(struct perf_event
*event
)
7192 struct hw_perf_event
*hwc
= &event
->hw
;
7194 if (is_sampling_event(event
)) {
7195 ktime_t remaining
= hrtimer_get_remaining(&hwc
->hrtimer
);
7196 local64_set(&hwc
->period_left
, ktime_to_ns(remaining
));
7198 hrtimer_cancel(&hwc
->hrtimer
);
7202 static void perf_swevent_init_hrtimer(struct perf_event
*event
)
7204 struct hw_perf_event
*hwc
= &event
->hw
;
7206 if (!is_sampling_event(event
))
7209 hrtimer_init(&hwc
->hrtimer
, CLOCK_MONOTONIC
, HRTIMER_MODE_REL
);
7210 hwc
->hrtimer
.function
= perf_swevent_hrtimer
;
7213 * Since hrtimers have a fixed rate, we can do a static freq->period
7214 * mapping and avoid the whole period adjust feedback stuff.
7216 if (event
->attr
.freq
) {
7217 long freq
= event
->attr
.sample_freq
;
7219 event
->attr
.sample_period
= NSEC_PER_SEC
/ freq
;
7220 hwc
->sample_period
= event
->attr
.sample_period
;
7221 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7222 hwc
->last_period
= hwc
->sample_period
;
7223 event
->attr
.freq
= 0;
7228 * Software event: cpu wall time clock
7231 static void cpu_clock_event_update(struct perf_event
*event
)
7236 now
= local_clock();
7237 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7238 local64_add(now
- prev
, &event
->count
);
7241 static void cpu_clock_event_start(struct perf_event
*event
, int flags
)
7243 local64_set(&event
->hw
.prev_count
, local_clock());
7244 perf_swevent_start_hrtimer(event
);
7247 static void cpu_clock_event_stop(struct perf_event
*event
, int flags
)
7249 perf_swevent_cancel_hrtimer(event
);
7250 cpu_clock_event_update(event
);
7253 static int cpu_clock_event_add(struct perf_event
*event
, int flags
)
7255 if (flags
& PERF_EF_START
)
7256 cpu_clock_event_start(event
, flags
);
7257 perf_event_update_userpage(event
);
7262 static void cpu_clock_event_del(struct perf_event
*event
, int flags
)
7264 cpu_clock_event_stop(event
, flags
);
7267 static void cpu_clock_event_read(struct perf_event
*event
)
7269 cpu_clock_event_update(event
);
7272 static int cpu_clock_event_init(struct perf_event
*event
)
7274 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7277 if (event
->attr
.config
!= PERF_COUNT_SW_CPU_CLOCK
)
7281 * no branch sampling for software events
7283 if (has_branch_stack(event
))
7286 perf_swevent_init_hrtimer(event
);
7291 static struct pmu perf_cpu_clock
= {
7292 .task_ctx_nr
= perf_sw_context
,
7294 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7296 .event_init
= cpu_clock_event_init
,
7297 .add
= cpu_clock_event_add
,
7298 .del
= cpu_clock_event_del
,
7299 .start
= cpu_clock_event_start
,
7300 .stop
= cpu_clock_event_stop
,
7301 .read
= cpu_clock_event_read
,
7305 * Software event: task time clock
7308 static void task_clock_event_update(struct perf_event
*event
, u64 now
)
7313 prev
= local64_xchg(&event
->hw
.prev_count
, now
);
7315 local64_add(delta
, &event
->count
);
7318 static void task_clock_event_start(struct perf_event
*event
, int flags
)
7320 local64_set(&event
->hw
.prev_count
, event
->ctx
->time
);
7321 perf_swevent_start_hrtimer(event
);
7324 static void task_clock_event_stop(struct perf_event
*event
, int flags
)
7326 perf_swevent_cancel_hrtimer(event
);
7327 task_clock_event_update(event
, event
->ctx
->time
);
7330 static int task_clock_event_add(struct perf_event
*event
, int flags
)
7332 if (flags
& PERF_EF_START
)
7333 task_clock_event_start(event
, flags
);
7334 perf_event_update_userpage(event
);
7339 static void task_clock_event_del(struct perf_event
*event
, int flags
)
7341 task_clock_event_stop(event
, PERF_EF_UPDATE
);
7344 static void task_clock_event_read(struct perf_event
*event
)
7346 u64 now
= perf_clock();
7347 u64 delta
= now
- event
->ctx
->timestamp
;
7348 u64 time
= event
->ctx
->time
+ delta
;
7350 task_clock_event_update(event
, time
);
7353 static int task_clock_event_init(struct perf_event
*event
)
7355 if (event
->attr
.type
!= PERF_TYPE_SOFTWARE
)
7358 if (event
->attr
.config
!= PERF_COUNT_SW_TASK_CLOCK
)
7362 * no branch sampling for software events
7364 if (has_branch_stack(event
))
7367 perf_swevent_init_hrtimer(event
);
7372 static struct pmu perf_task_clock
= {
7373 .task_ctx_nr
= perf_sw_context
,
7375 .capabilities
= PERF_PMU_CAP_NO_NMI
,
7377 .event_init
= task_clock_event_init
,
7378 .add
= task_clock_event_add
,
7379 .del
= task_clock_event_del
,
7380 .start
= task_clock_event_start
,
7381 .stop
= task_clock_event_stop
,
7382 .read
= task_clock_event_read
,
7385 static void perf_pmu_nop_void(struct pmu
*pmu
)
7389 static void perf_pmu_nop_txn(struct pmu
*pmu
, unsigned int flags
)
7393 static int perf_pmu_nop_int(struct pmu
*pmu
)
7398 static DEFINE_PER_CPU(unsigned int, nop_txn_flags
);
7400 static void perf_pmu_start_txn(struct pmu
*pmu
, unsigned int flags
)
7402 __this_cpu_write(nop_txn_flags
, flags
);
7404 if (flags
& ~PERF_PMU_TXN_ADD
)
7407 perf_pmu_disable(pmu
);
7410 static int perf_pmu_commit_txn(struct pmu
*pmu
)
7412 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7414 __this_cpu_write(nop_txn_flags
, 0);
7416 if (flags
& ~PERF_PMU_TXN_ADD
)
7419 perf_pmu_enable(pmu
);
7423 static void perf_pmu_cancel_txn(struct pmu
*pmu
)
7425 unsigned int flags
= __this_cpu_read(nop_txn_flags
);
7427 __this_cpu_write(nop_txn_flags
, 0);
7429 if (flags
& ~PERF_PMU_TXN_ADD
)
7432 perf_pmu_enable(pmu
);
7435 static int perf_event_idx_default(struct perf_event
*event
)
7441 * Ensures all contexts with the same task_ctx_nr have the same
7442 * pmu_cpu_context too.
7444 static struct perf_cpu_context __percpu
*find_pmu_context(int ctxn
)
7451 list_for_each_entry(pmu
, &pmus
, entry
) {
7452 if (pmu
->task_ctx_nr
== ctxn
)
7453 return pmu
->pmu_cpu_context
;
7459 static void update_pmu_context(struct pmu
*pmu
, struct pmu
*old_pmu
)
7463 for_each_possible_cpu(cpu
) {
7464 struct perf_cpu_context
*cpuctx
;
7466 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7468 if (cpuctx
->unique_pmu
== old_pmu
)
7469 cpuctx
->unique_pmu
= pmu
;
7473 static void free_pmu_context(struct pmu
*pmu
)
7477 mutex_lock(&pmus_lock
);
7479 * Like a real lame refcount.
7481 list_for_each_entry(i
, &pmus
, entry
) {
7482 if (i
->pmu_cpu_context
== pmu
->pmu_cpu_context
) {
7483 update_pmu_context(i
, pmu
);
7488 free_percpu(pmu
->pmu_cpu_context
);
7490 mutex_unlock(&pmus_lock
);
7492 static struct idr pmu_idr
;
7495 type_show(struct device
*dev
, struct device_attribute
*attr
, char *page
)
7497 struct pmu
*pmu
= dev_get_drvdata(dev
);
7499 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->type
);
7501 static DEVICE_ATTR_RO(type
);
7504 perf_event_mux_interval_ms_show(struct device
*dev
,
7505 struct device_attribute
*attr
,
7508 struct pmu
*pmu
= dev_get_drvdata(dev
);
7510 return snprintf(page
, PAGE_SIZE
-1, "%d\n", pmu
->hrtimer_interval_ms
);
7513 static DEFINE_MUTEX(mux_interval_mutex
);
7516 perf_event_mux_interval_ms_store(struct device
*dev
,
7517 struct device_attribute
*attr
,
7518 const char *buf
, size_t count
)
7520 struct pmu
*pmu
= dev_get_drvdata(dev
);
7521 int timer
, cpu
, ret
;
7523 ret
= kstrtoint(buf
, 0, &timer
);
7530 /* same value, noting to do */
7531 if (timer
== pmu
->hrtimer_interval_ms
)
7534 mutex_lock(&mux_interval_mutex
);
7535 pmu
->hrtimer_interval_ms
= timer
;
7537 /* update all cpuctx for this PMU */
7539 for_each_online_cpu(cpu
) {
7540 struct perf_cpu_context
*cpuctx
;
7541 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7542 cpuctx
->hrtimer_interval
= ns_to_ktime(NSEC_PER_MSEC
* timer
);
7544 cpu_function_call(cpu
,
7545 (remote_function_f
)perf_mux_hrtimer_restart
, cpuctx
);
7548 mutex_unlock(&mux_interval_mutex
);
7552 static DEVICE_ATTR_RW(perf_event_mux_interval_ms
);
7554 static struct attribute
*pmu_dev_attrs
[] = {
7555 &dev_attr_type
.attr
,
7556 &dev_attr_perf_event_mux_interval_ms
.attr
,
7559 ATTRIBUTE_GROUPS(pmu_dev
);
7561 static int pmu_bus_running
;
7562 static struct bus_type pmu_bus
= {
7563 .name
= "event_source",
7564 .dev_groups
= pmu_dev_groups
,
7567 static void pmu_dev_release(struct device
*dev
)
7572 static int pmu_dev_alloc(struct pmu
*pmu
)
7576 pmu
->dev
= kzalloc(sizeof(struct device
), GFP_KERNEL
);
7580 pmu
->dev
->groups
= pmu
->attr_groups
;
7581 device_initialize(pmu
->dev
);
7582 ret
= dev_set_name(pmu
->dev
, "%s", pmu
->name
);
7586 dev_set_drvdata(pmu
->dev
, pmu
);
7587 pmu
->dev
->bus
= &pmu_bus
;
7588 pmu
->dev
->release
= pmu_dev_release
;
7589 ret
= device_add(pmu
->dev
);
7597 put_device(pmu
->dev
);
7601 static struct lock_class_key cpuctx_mutex
;
7602 static struct lock_class_key cpuctx_lock
;
7604 int perf_pmu_register(struct pmu
*pmu
, const char *name
, int type
)
7608 mutex_lock(&pmus_lock
);
7610 pmu
->pmu_disable_count
= alloc_percpu(int);
7611 if (!pmu
->pmu_disable_count
)
7620 type
= idr_alloc(&pmu_idr
, pmu
, PERF_TYPE_MAX
, 0, GFP_KERNEL
);
7628 if (pmu_bus_running
) {
7629 ret
= pmu_dev_alloc(pmu
);
7635 pmu
->pmu_cpu_context
= find_pmu_context(pmu
->task_ctx_nr
);
7636 if (pmu
->pmu_cpu_context
)
7637 goto got_cpu_context
;
7640 pmu
->pmu_cpu_context
= alloc_percpu(struct perf_cpu_context
);
7641 if (!pmu
->pmu_cpu_context
)
7644 for_each_possible_cpu(cpu
) {
7645 struct perf_cpu_context
*cpuctx
;
7647 cpuctx
= per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
);
7648 __perf_event_init_context(&cpuctx
->ctx
);
7649 lockdep_set_class(&cpuctx
->ctx
.mutex
, &cpuctx_mutex
);
7650 lockdep_set_class(&cpuctx
->ctx
.lock
, &cpuctx_lock
);
7651 cpuctx
->ctx
.pmu
= pmu
;
7653 __perf_mux_hrtimer_init(cpuctx
, cpu
);
7655 cpuctx
->unique_pmu
= pmu
;
7659 if (!pmu
->start_txn
) {
7660 if (pmu
->pmu_enable
) {
7662 * If we have pmu_enable/pmu_disable calls, install
7663 * transaction stubs that use that to try and batch
7664 * hardware accesses.
7666 pmu
->start_txn
= perf_pmu_start_txn
;
7667 pmu
->commit_txn
= perf_pmu_commit_txn
;
7668 pmu
->cancel_txn
= perf_pmu_cancel_txn
;
7670 pmu
->start_txn
= perf_pmu_nop_txn
;
7671 pmu
->commit_txn
= perf_pmu_nop_int
;
7672 pmu
->cancel_txn
= perf_pmu_nop_void
;
7676 if (!pmu
->pmu_enable
) {
7677 pmu
->pmu_enable
= perf_pmu_nop_void
;
7678 pmu
->pmu_disable
= perf_pmu_nop_void
;
7681 if (!pmu
->event_idx
)
7682 pmu
->event_idx
= perf_event_idx_default
;
7684 list_add_rcu(&pmu
->entry
, &pmus
);
7685 atomic_set(&pmu
->exclusive_cnt
, 0);
7688 mutex_unlock(&pmus_lock
);
7693 device_del(pmu
->dev
);
7694 put_device(pmu
->dev
);
7697 if (pmu
->type
>= PERF_TYPE_MAX
)
7698 idr_remove(&pmu_idr
, pmu
->type
);
7701 free_percpu(pmu
->pmu_disable_count
);
7704 EXPORT_SYMBOL_GPL(perf_pmu_register
);
7706 void perf_pmu_unregister(struct pmu
*pmu
)
7708 mutex_lock(&pmus_lock
);
7709 list_del_rcu(&pmu
->entry
);
7710 mutex_unlock(&pmus_lock
);
7713 * We dereference the pmu list under both SRCU and regular RCU, so
7714 * synchronize against both of those.
7716 synchronize_srcu(&pmus_srcu
);
7719 free_percpu(pmu
->pmu_disable_count
);
7720 if (pmu
->type
>= PERF_TYPE_MAX
)
7721 idr_remove(&pmu_idr
, pmu
->type
);
7722 device_del(pmu
->dev
);
7723 put_device(pmu
->dev
);
7724 free_pmu_context(pmu
);
7726 EXPORT_SYMBOL_GPL(perf_pmu_unregister
);
7728 static int perf_try_init_event(struct pmu
*pmu
, struct perf_event
*event
)
7730 struct perf_event_context
*ctx
= NULL
;
7733 if (!try_module_get(pmu
->module
))
7736 if (event
->group_leader
!= event
) {
7738 * This ctx->mutex can nest when we're called through
7739 * inheritance. See the perf_event_ctx_lock_nested() comment.
7741 ctx
= perf_event_ctx_lock_nested(event
->group_leader
,
7742 SINGLE_DEPTH_NESTING
);
7747 ret
= pmu
->event_init(event
);
7750 perf_event_ctx_unlock(event
->group_leader
, ctx
);
7753 module_put(pmu
->module
);
7758 static struct pmu
*perf_init_event(struct perf_event
*event
)
7760 struct pmu
*pmu
= NULL
;
7764 idx
= srcu_read_lock(&pmus_srcu
);
7767 pmu
= idr_find(&pmu_idr
, event
->attr
.type
);
7770 ret
= perf_try_init_event(pmu
, event
);
7776 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
7777 ret
= perf_try_init_event(pmu
, event
);
7781 if (ret
!= -ENOENT
) {
7786 pmu
= ERR_PTR(-ENOENT
);
7788 srcu_read_unlock(&pmus_srcu
, idx
);
7793 static void account_event_cpu(struct perf_event
*event
, int cpu
)
7798 if (is_cgroup_event(event
))
7799 atomic_inc(&per_cpu(perf_cgroup_events
, cpu
));
7802 static void account_event(struct perf_event
*event
)
7807 if (event
->attach_state
& PERF_ATTACH_TASK
)
7808 static_key_slow_inc(&perf_sched_events
.key
);
7809 if (event
->attr
.mmap
|| event
->attr
.mmap_data
)
7810 atomic_inc(&nr_mmap_events
);
7811 if (event
->attr
.comm
)
7812 atomic_inc(&nr_comm_events
);
7813 if (event
->attr
.task
)
7814 atomic_inc(&nr_task_events
);
7815 if (event
->attr
.freq
) {
7816 if (atomic_inc_return(&nr_freq_events
) == 1)
7817 tick_nohz_full_kick_all();
7819 if (event
->attr
.context_switch
) {
7820 atomic_inc(&nr_switch_events
);
7821 static_key_slow_inc(&perf_sched_events
.key
);
7823 if (has_branch_stack(event
))
7824 static_key_slow_inc(&perf_sched_events
.key
);
7825 if (is_cgroup_event(event
))
7826 static_key_slow_inc(&perf_sched_events
.key
);
7828 account_event_cpu(event
, event
->cpu
);
7832 * Allocate and initialize a event structure
7834 static struct perf_event
*
7835 perf_event_alloc(struct perf_event_attr
*attr
, int cpu
,
7836 struct task_struct
*task
,
7837 struct perf_event
*group_leader
,
7838 struct perf_event
*parent_event
,
7839 perf_overflow_handler_t overflow_handler
,
7840 void *context
, int cgroup_fd
)
7843 struct perf_event
*event
;
7844 struct hw_perf_event
*hwc
;
7847 if ((unsigned)cpu
>= nr_cpu_ids
) {
7848 if (!task
|| cpu
!= -1)
7849 return ERR_PTR(-EINVAL
);
7852 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
7854 return ERR_PTR(-ENOMEM
);
7857 * Single events are their own group leaders, with an
7858 * empty sibling list:
7861 group_leader
= event
;
7863 mutex_init(&event
->child_mutex
);
7864 INIT_LIST_HEAD(&event
->child_list
);
7866 INIT_LIST_HEAD(&event
->group_entry
);
7867 INIT_LIST_HEAD(&event
->event_entry
);
7868 INIT_LIST_HEAD(&event
->sibling_list
);
7869 INIT_LIST_HEAD(&event
->rb_entry
);
7870 INIT_LIST_HEAD(&event
->active_entry
);
7871 INIT_HLIST_NODE(&event
->hlist_entry
);
7874 init_waitqueue_head(&event
->waitq
);
7875 init_irq_work(&event
->pending
, perf_pending_event
);
7877 mutex_init(&event
->mmap_mutex
);
7879 atomic_long_set(&event
->refcount
, 1);
7881 event
->attr
= *attr
;
7882 event
->group_leader
= group_leader
;
7886 event
->parent
= parent_event
;
7888 event
->ns
= get_pid_ns(task_active_pid_ns(current
));
7889 event
->id
= atomic64_inc_return(&perf_event_id
);
7891 event
->state
= PERF_EVENT_STATE_INACTIVE
;
7894 event
->attach_state
= PERF_ATTACH_TASK
;
7896 * XXX pmu::event_init needs to know what task to account to
7897 * and we cannot use the ctx information because we need the
7898 * pmu before we get a ctx.
7900 event
->hw
.target
= task
;
7903 event
->clock
= &local_clock
;
7905 event
->clock
= parent_event
->clock
;
7907 if (!overflow_handler
&& parent_event
) {
7908 overflow_handler
= parent_event
->overflow_handler
;
7909 context
= parent_event
->overflow_handler_context
;
7912 event
->overflow_handler
= overflow_handler
;
7913 event
->overflow_handler_context
= context
;
7915 perf_event__state_init(event
);
7920 hwc
->sample_period
= attr
->sample_period
;
7921 if (attr
->freq
&& attr
->sample_freq
)
7922 hwc
->sample_period
= 1;
7923 hwc
->last_period
= hwc
->sample_period
;
7925 local64_set(&hwc
->period_left
, hwc
->sample_period
);
7928 * we currently do not support PERF_FORMAT_GROUP on inherited events
7930 if (attr
->inherit
&& (attr
->read_format
& PERF_FORMAT_GROUP
))
7933 if (!has_branch_stack(event
))
7934 event
->attr
.branch_sample_type
= 0;
7936 if (cgroup_fd
!= -1) {
7937 err
= perf_cgroup_connect(cgroup_fd
, event
, attr
, group_leader
);
7942 pmu
= perf_init_event(event
);
7945 else if (IS_ERR(pmu
)) {
7950 err
= exclusive_event_init(event
);
7954 if (!event
->parent
) {
7955 if (event
->attr
.sample_type
& PERF_SAMPLE_CALLCHAIN
) {
7956 err
= get_callchain_buffers();
7965 exclusive_event_destroy(event
);
7969 event
->destroy(event
);
7970 module_put(pmu
->module
);
7972 if (is_cgroup_event(event
))
7973 perf_detach_cgroup(event
);
7975 put_pid_ns(event
->ns
);
7978 return ERR_PTR(err
);
7981 static int perf_copy_attr(struct perf_event_attr __user
*uattr
,
7982 struct perf_event_attr
*attr
)
7987 if (!access_ok(VERIFY_WRITE
, uattr
, PERF_ATTR_SIZE_VER0
))
7991 * zero the full structure, so that a short copy will be nice.
7993 memset(attr
, 0, sizeof(*attr
));
7995 ret
= get_user(size
, &uattr
->size
);
7999 if (size
> PAGE_SIZE
) /* silly large */
8002 if (!size
) /* abi compat */
8003 size
= PERF_ATTR_SIZE_VER0
;
8005 if (size
< PERF_ATTR_SIZE_VER0
)
8009 * If we're handed a bigger struct than we know of,
8010 * ensure all the unknown bits are 0 - i.e. new
8011 * user-space does not rely on any kernel feature
8012 * extensions we dont know about yet.
8014 if (size
> sizeof(*attr
)) {
8015 unsigned char __user
*addr
;
8016 unsigned char __user
*end
;
8019 addr
= (void __user
*)uattr
+ sizeof(*attr
);
8020 end
= (void __user
*)uattr
+ size
;
8022 for (; addr
< end
; addr
++) {
8023 ret
= get_user(val
, addr
);
8029 size
= sizeof(*attr
);
8032 ret
= copy_from_user(attr
, uattr
, size
);
8036 if (attr
->__reserved_1
)
8039 if (attr
->sample_type
& ~(PERF_SAMPLE_MAX
-1))
8042 if (attr
->read_format
& ~(PERF_FORMAT_MAX
-1))
8045 if (attr
->sample_type
& PERF_SAMPLE_BRANCH_STACK
) {
8046 u64 mask
= attr
->branch_sample_type
;
8048 /* only using defined bits */
8049 if (mask
& ~(PERF_SAMPLE_BRANCH_MAX
-1))
8052 /* at least one branch bit must be set */
8053 if (!(mask
& ~PERF_SAMPLE_BRANCH_PLM_ALL
))
8056 /* propagate priv level, when not set for branch */
8057 if (!(mask
& PERF_SAMPLE_BRANCH_PLM_ALL
)) {
8059 /* exclude_kernel checked on syscall entry */
8060 if (!attr
->exclude_kernel
)
8061 mask
|= PERF_SAMPLE_BRANCH_KERNEL
;
8063 if (!attr
->exclude_user
)
8064 mask
|= PERF_SAMPLE_BRANCH_USER
;
8066 if (!attr
->exclude_hv
)
8067 mask
|= PERF_SAMPLE_BRANCH_HV
;
8069 * adjust user setting (for HW filter setup)
8071 attr
->branch_sample_type
= mask
;
8073 /* privileged levels capture (kernel, hv): check permissions */
8074 if ((mask
& PERF_SAMPLE_BRANCH_PERM_PLM
)
8075 && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8079 if (attr
->sample_type
& PERF_SAMPLE_REGS_USER
) {
8080 ret
= perf_reg_validate(attr
->sample_regs_user
);
8085 if (attr
->sample_type
& PERF_SAMPLE_STACK_USER
) {
8086 if (!arch_perf_have_user_stack_dump())
8090 * We have __u32 type for the size, but so far
8091 * we can only use __u16 as maximum due to the
8092 * __u16 sample size limit.
8094 if (attr
->sample_stack_user
>= USHRT_MAX
)
8096 else if (!IS_ALIGNED(attr
->sample_stack_user
, sizeof(u64
)))
8100 if (attr
->sample_type
& PERF_SAMPLE_REGS_INTR
)
8101 ret
= perf_reg_validate(attr
->sample_regs_intr
);
8106 put_user(sizeof(*attr
), &uattr
->size
);
8112 perf_event_set_output(struct perf_event
*event
, struct perf_event
*output_event
)
8114 struct ring_buffer
*rb
= NULL
;
8120 /* don't allow circular references */
8121 if (event
== output_event
)
8125 * Don't allow cross-cpu buffers
8127 if (output_event
->cpu
!= event
->cpu
)
8131 * If its not a per-cpu rb, it must be the same task.
8133 if (output_event
->cpu
== -1 && output_event
->ctx
!= event
->ctx
)
8137 * Mixing clocks in the same buffer is trouble you don't need.
8139 if (output_event
->clock
!= event
->clock
)
8143 * If both events generate aux data, they must be on the same PMU
8145 if (has_aux(event
) && has_aux(output_event
) &&
8146 event
->pmu
!= output_event
->pmu
)
8150 mutex_lock(&event
->mmap_mutex
);
8151 /* Can't redirect output if we've got an active mmap() */
8152 if (atomic_read(&event
->mmap_count
))
8156 /* get the rb we want to redirect to */
8157 rb
= ring_buffer_get(output_event
);
8162 ring_buffer_attach(event
, rb
);
8166 mutex_unlock(&event
->mmap_mutex
);
8172 static void mutex_lock_double(struct mutex
*a
, struct mutex
*b
)
8178 mutex_lock_nested(b
, SINGLE_DEPTH_NESTING
);
8181 static int perf_event_set_clock(struct perf_event
*event
, clockid_t clk_id
)
8183 bool nmi_safe
= false;
8186 case CLOCK_MONOTONIC
:
8187 event
->clock
= &ktime_get_mono_fast_ns
;
8191 case CLOCK_MONOTONIC_RAW
:
8192 event
->clock
= &ktime_get_raw_fast_ns
;
8196 case CLOCK_REALTIME
:
8197 event
->clock
= &ktime_get_real_ns
;
8200 case CLOCK_BOOTTIME
:
8201 event
->clock
= &ktime_get_boot_ns
;
8205 event
->clock
= &ktime_get_tai_ns
;
8212 if (!nmi_safe
&& !(event
->pmu
->capabilities
& PERF_PMU_CAP_NO_NMI
))
8219 * sys_perf_event_open - open a performance event, associate it to a task/cpu
8221 * @attr_uptr: event_id type attributes for monitoring/sampling
8224 * @group_fd: group leader event fd
8226 SYSCALL_DEFINE5(perf_event_open
,
8227 struct perf_event_attr __user
*, attr_uptr
,
8228 pid_t
, pid
, int, cpu
, int, group_fd
, unsigned long, flags
)
8230 struct perf_event
*group_leader
= NULL
, *output_event
= NULL
;
8231 struct perf_event
*event
, *sibling
;
8232 struct perf_event_attr attr
;
8233 struct perf_event_context
*ctx
, *uninitialized_var(gctx
);
8234 struct file
*event_file
= NULL
;
8235 struct fd group
= {NULL
, 0};
8236 struct task_struct
*task
= NULL
;
8241 int f_flags
= O_RDWR
;
8244 /* for future expandability... */
8245 if (flags
& ~PERF_FLAG_ALL
)
8248 err
= perf_copy_attr(attr_uptr
, &attr
);
8252 if (!attr
.exclude_kernel
) {
8253 if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN
))
8258 if (attr
.sample_freq
> sysctl_perf_event_sample_rate
)
8261 if (attr
.sample_period
& (1ULL << 63))
8266 * In cgroup mode, the pid argument is used to pass the fd
8267 * opened to the cgroup directory in cgroupfs. The cpu argument
8268 * designates the cpu on which to monitor threads from that
8271 if ((flags
& PERF_FLAG_PID_CGROUP
) && (pid
== -1 || cpu
== -1))
8274 if (flags
& PERF_FLAG_FD_CLOEXEC
)
8275 f_flags
|= O_CLOEXEC
;
8277 event_fd
= get_unused_fd_flags(f_flags
);
8281 if (group_fd
!= -1) {
8282 err
= perf_fget_light(group_fd
, &group
);
8285 group_leader
= group
.file
->private_data
;
8286 if (flags
& PERF_FLAG_FD_OUTPUT
)
8287 output_event
= group_leader
;
8288 if (flags
& PERF_FLAG_FD_NO_GROUP
)
8289 group_leader
= NULL
;
8292 if (pid
!= -1 && !(flags
& PERF_FLAG_PID_CGROUP
)) {
8293 task
= find_lively_task_by_vpid(pid
);
8295 err
= PTR_ERR(task
);
8300 if (task
&& group_leader
&&
8301 group_leader
->attr
.inherit
!= attr
.inherit
) {
8308 if (flags
& PERF_FLAG_PID_CGROUP
)
8311 event
= perf_event_alloc(&attr
, cpu
, task
, group_leader
, NULL
,
8312 NULL
, NULL
, cgroup_fd
);
8313 if (IS_ERR(event
)) {
8314 err
= PTR_ERR(event
);
8318 if (is_sampling_event(event
)) {
8319 if (event
->pmu
->capabilities
& PERF_PMU_CAP_NO_INTERRUPT
) {
8325 account_event(event
);
8328 * Special case software events and allow them to be part of
8329 * any hardware group.
8333 if (attr
.use_clockid
) {
8334 err
= perf_event_set_clock(event
, attr
.clockid
);
8340 (is_software_event(event
) != is_software_event(group_leader
))) {
8341 if (is_software_event(event
)) {
8343 * If event and group_leader are not both a software
8344 * event, and event is, then group leader is not.
8346 * Allow the addition of software events to !software
8347 * groups, this is safe because software events never
8350 pmu
= group_leader
->pmu
;
8351 } else if (is_software_event(group_leader
) &&
8352 (group_leader
->group_flags
& PERF_GROUP_SOFTWARE
)) {
8354 * In case the group is a pure software group, and we
8355 * try to add a hardware event, move the whole group to
8356 * the hardware context.
8363 * Get the target context (task or percpu):
8365 ctx
= find_get_context(pmu
, task
, event
);
8371 if ((pmu
->capabilities
& PERF_PMU_CAP_EXCLUSIVE
) && group_leader
) {
8377 put_task_struct(task
);
8382 * Look up the group leader (we will attach this event to it):
8388 * Do not allow a recursive hierarchy (this new sibling
8389 * becoming part of another group-sibling):
8391 if (group_leader
->group_leader
!= group_leader
)
8394 /* All events in a group should have the same clock */
8395 if (group_leader
->clock
!= event
->clock
)
8399 * Do not allow to attach to a group in a different
8400 * task or CPU context:
8404 * Make sure we're both on the same task, or both
8407 if (group_leader
->ctx
->task
!= ctx
->task
)
8411 * Make sure we're both events for the same CPU;
8412 * grouping events for different CPUs is broken; since
8413 * you can never concurrently schedule them anyhow.
8415 if (group_leader
->cpu
!= event
->cpu
)
8418 if (group_leader
->ctx
!= ctx
)
8423 * Only a group leader can be exclusive or pinned
8425 if (attr
.exclusive
|| attr
.pinned
)
8430 err
= perf_event_set_output(event
, output_event
);
8435 event_file
= anon_inode_getfile("[perf_event]", &perf_fops
, event
,
8437 if (IS_ERR(event_file
)) {
8438 err
= PTR_ERR(event_file
);
8443 gctx
= group_leader
->ctx
;
8444 mutex_lock_double(&gctx
->mutex
, &ctx
->mutex
);
8446 mutex_lock(&ctx
->mutex
);
8449 if (!perf_event_validate_size(event
)) {
8455 * Must be under the same ctx::mutex as perf_install_in_context(),
8456 * because we need to serialize with concurrent event creation.
8458 if (!exclusive_event_installable(event
, ctx
)) {
8459 /* exclusive and group stuff are assumed mutually exclusive */
8460 WARN_ON_ONCE(move_group
);
8466 WARN_ON_ONCE(ctx
->parent_ctx
);
8470 * See perf_event_ctx_lock() for comments on the details
8471 * of swizzling perf_event::ctx.
8473 perf_remove_from_context(group_leader
, false);
8475 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8477 perf_remove_from_context(sibling
, false);
8482 * Wait for everybody to stop referencing the events through
8483 * the old lists, before installing it on new lists.
8488 * Install the group siblings before the group leader.
8490 * Because a group leader will try and install the entire group
8491 * (through the sibling list, which is still in-tact), we can
8492 * end up with siblings installed in the wrong context.
8494 * By installing siblings first we NO-OP because they're not
8495 * reachable through the group lists.
8497 list_for_each_entry(sibling
, &group_leader
->sibling_list
,
8499 perf_event__state_init(sibling
);
8500 perf_install_in_context(ctx
, sibling
, sibling
->cpu
);
8505 * Removing from the context ends up with disabled
8506 * event. What we want here is event in the initial
8507 * startup state, ready to be add into new context.
8509 perf_event__state_init(group_leader
);
8510 perf_install_in_context(ctx
, group_leader
, group_leader
->cpu
);
8514 * Now that all events are installed in @ctx, nothing
8515 * references @gctx anymore, so drop the last reference we have
8522 * Precalculate sample_data sizes; do while holding ctx::mutex such
8523 * that we're serialized against further additions and before
8524 * perf_install_in_context() which is the point the event is active and
8525 * can use these values.
8527 perf_event__header_size(event
);
8528 perf_event__id_header_size(event
);
8530 perf_install_in_context(ctx
, event
, event
->cpu
);
8531 perf_unpin_context(ctx
);
8534 mutex_unlock(&gctx
->mutex
);
8535 mutex_unlock(&ctx
->mutex
);
8539 event
->owner
= current
;
8541 mutex_lock(¤t
->perf_event_mutex
);
8542 list_add_tail(&event
->owner_entry
, ¤t
->perf_event_list
);
8543 mutex_unlock(¤t
->perf_event_mutex
);
8546 * Drop the reference on the group_event after placing the
8547 * new event on the sibling_list. This ensures destruction
8548 * of the group leader will find the pointer to itself in
8549 * perf_group_detach().
8552 fd_install(event_fd
, event_file
);
8557 mutex_unlock(&gctx
->mutex
);
8558 mutex_unlock(&ctx
->mutex
);
8562 perf_unpin_context(ctx
);
8570 put_task_struct(task
);
8574 put_unused_fd(event_fd
);
8579 * perf_event_create_kernel_counter
8581 * @attr: attributes of the counter to create
8582 * @cpu: cpu in which the counter is bound
8583 * @task: task to profile (NULL for percpu)
8586 perf_event_create_kernel_counter(struct perf_event_attr
*attr
, int cpu
,
8587 struct task_struct
*task
,
8588 perf_overflow_handler_t overflow_handler
,
8591 struct perf_event_context
*ctx
;
8592 struct perf_event
*event
;
8596 * Get the target context (task or percpu):
8599 event
= perf_event_alloc(attr
, cpu
, task
, NULL
, NULL
,
8600 overflow_handler
, context
, -1);
8601 if (IS_ERR(event
)) {
8602 err
= PTR_ERR(event
);
8606 /* Mark owner so we could distinguish it from user events. */
8607 event
->owner
= EVENT_OWNER_KERNEL
;
8609 account_event(event
);
8611 ctx
= find_get_context(event
->pmu
, task
, event
);
8617 WARN_ON_ONCE(ctx
->parent_ctx
);
8618 mutex_lock(&ctx
->mutex
);
8619 if (!exclusive_event_installable(event
, ctx
)) {
8620 mutex_unlock(&ctx
->mutex
);
8621 perf_unpin_context(ctx
);
8627 perf_install_in_context(ctx
, event
, cpu
);
8628 perf_unpin_context(ctx
);
8629 mutex_unlock(&ctx
->mutex
);
8636 return ERR_PTR(err
);
8638 EXPORT_SYMBOL_GPL(perf_event_create_kernel_counter
);
8640 void perf_pmu_migrate_context(struct pmu
*pmu
, int src_cpu
, int dst_cpu
)
8642 struct perf_event_context
*src_ctx
;
8643 struct perf_event_context
*dst_ctx
;
8644 struct perf_event
*event
, *tmp
;
8647 src_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, src_cpu
)->ctx
;
8648 dst_ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, dst_cpu
)->ctx
;
8651 * See perf_event_ctx_lock() for comments on the details
8652 * of swizzling perf_event::ctx.
8654 mutex_lock_double(&src_ctx
->mutex
, &dst_ctx
->mutex
);
8655 list_for_each_entry_safe(event
, tmp
, &src_ctx
->event_list
,
8657 perf_remove_from_context(event
, false);
8658 unaccount_event_cpu(event
, src_cpu
);
8660 list_add(&event
->migrate_entry
, &events
);
8664 * Wait for the events to quiesce before re-instating them.
8669 * Re-instate events in 2 passes.
8671 * Skip over group leaders and only install siblings on this first
8672 * pass, siblings will not get enabled without a leader, however a
8673 * leader will enable its siblings, even if those are still on the old
8676 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8677 if (event
->group_leader
== event
)
8680 list_del(&event
->migrate_entry
);
8681 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8682 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8683 account_event_cpu(event
, dst_cpu
);
8684 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8689 * Once all the siblings are setup properly, install the group leaders
8692 list_for_each_entry_safe(event
, tmp
, &events
, migrate_entry
) {
8693 list_del(&event
->migrate_entry
);
8694 if (event
->state
>= PERF_EVENT_STATE_OFF
)
8695 event
->state
= PERF_EVENT_STATE_INACTIVE
;
8696 account_event_cpu(event
, dst_cpu
);
8697 perf_install_in_context(dst_ctx
, event
, dst_cpu
);
8700 mutex_unlock(&dst_ctx
->mutex
);
8701 mutex_unlock(&src_ctx
->mutex
);
8703 EXPORT_SYMBOL_GPL(perf_pmu_migrate_context
);
8705 static void sync_child_event(struct perf_event
*child_event
,
8706 struct task_struct
*child
)
8708 struct perf_event
*parent_event
= child_event
->parent
;
8711 if (child_event
->attr
.inherit_stat
)
8712 perf_event_read_event(child_event
, child
);
8714 child_val
= perf_event_count(child_event
);
8717 * Add back the child's count to the parent's count:
8719 atomic64_add(child_val
, &parent_event
->child_count
);
8720 atomic64_add(child_event
->total_time_enabled
,
8721 &parent_event
->child_total_time_enabled
);
8722 atomic64_add(child_event
->total_time_running
,
8723 &parent_event
->child_total_time_running
);
8726 * Remove this event from the parent's list
8728 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
8729 mutex_lock(&parent_event
->child_mutex
);
8730 list_del_init(&child_event
->child_list
);
8731 mutex_unlock(&parent_event
->child_mutex
);
8734 * Make sure user/parent get notified, that we just
8737 perf_event_wakeup(parent_event
);
8740 * Release the parent event, if this was the last
8743 put_event(parent_event
);
8747 __perf_event_exit_task(struct perf_event
*child_event
,
8748 struct perf_event_context
*child_ctx
,
8749 struct task_struct
*child
)
8752 * Do not destroy the 'original' grouping; because of the context
8753 * switch optimization the original events could've ended up in a
8754 * random child task.
8756 * If we were to destroy the original group, all group related
8757 * operations would cease to function properly after this random
8760 * Do destroy all inherited groups, we don't care about those
8761 * and being thorough is better.
8763 perf_remove_from_context(child_event
, !!child_event
->parent
);
8766 * It can happen that the parent exits first, and has events
8767 * that are still around due to the child reference. These
8768 * events need to be zapped.
8770 if (child_event
->parent
) {
8771 sync_child_event(child_event
, child
);
8772 free_event(child_event
);
8774 child_event
->state
= PERF_EVENT_STATE_EXIT
;
8775 perf_event_wakeup(child_event
);
8779 static void perf_event_exit_task_context(struct task_struct
*child
, int ctxn
)
8781 struct perf_event
*child_event
, *next
;
8782 struct perf_event_context
*child_ctx
, *clone_ctx
= NULL
;
8783 unsigned long flags
;
8785 if (likely(!child
->perf_event_ctxp
[ctxn
])) {
8786 perf_event_task(child
, NULL
, 0);
8790 local_irq_save(flags
);
8792 * We can't reschedule here because interrupts are disabled,
8793 * and either child is current or it is a task that can't be
8794 * scheduled, so we are now safe from rescheduling changing
8797 child_ctx
= rcu_dereference_raw(child
->perf_event_ctxp
[ctxn
]);
8800 * Take the context lock here so that if find_get_context is
8801 * reading child->perf_event_ctxp, we wait until it has
8802 * incremented the context's refcount before we do put_ctx below.
8804 raw_spin_lock(&child_ctx
->lock
);
8805 task_ctx_sched_out(child_ctx
);
8806 child
->perf_event_ctxp
[ctxn
] = NULL
;
8809 * If this context is a clone; unclone it so it can't get
8810 * swapped to another process while we're removing all
8811 * the events from it.
8813 clone_ctx
= unclone_ctx(child_ctx
);
8814 update_context_time(child_ctx
);
8815 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
8821 * Report the task dead after unscheduling the events so that we
8822 * won't get any samples after PERF_RECORD_EXIT. We can however still
8823 * get a few PERF_RECORD_READ events.
8825 perf_event_task(child
, child_ctx
, 0);
8828 * We can recurse on the same lock type through:
8830 * __perf_event_exit_task()
8831 * sync_child_event()
8833 * mutex_lock(&ctx->mutex)
8835 * But since its the parent context it won't be the same instance.
8837 mutex_lock(&child_ctx
->mutex
);
8839 list_for_each_entry_safe(child_event
, next
, &child_ctx
->event_list
, event_entry
)
8840 __perf_event_exit_task(child_event
, child_ctx
, child
);
8842 mutex_unlock(&child_ctx
->mutex
);
8848 * When a child task exits, feed back event values to parent events.
8850 void perf_event_exit_task(struct task_struct
*child
)
8852 struct perf_event
*event
, *tmp
;
8855 mutex_lock(&child
->perf_event_mutex
);
8856 list_for_each_entry_safe(event
, tmp
, &child
->perf_event_list
,
8858 list_del_init(&event
->owner_entry
);
8861 * Ensure the list deletion is visible before we clear
8862 * the owner, closes a race against perf_release() where
8863 * we need to serialize on the owner->perf_event_mutex.
8866 event
->owner
= NULL
;
8868 mutex_unlock(&child
->perf_event_mutex
);
8870 for_each_task_context_nr(ctxn
)
8871 perf_event_exit_task_context(child
, ctxn
);
8874 static void perf_free_event(struct perf_event
*event
,
8875 struct perf_event_context
*ctx
)
8877 struct perf_event
*parent
= event
->parent
;
8879 if (WARN_ON_ONCE(!parent
))
8882 mutex_lock(&parent
->child_mutex
);
8883 list_del_init(&event
->child_list
);
8884 mutex_unlock(&parent
->child_mutex
);
8888 raw_spin_lock_irq(&ctx
->lock
);
8889 perf_group_detach(event
);
8890 list_del_event(event
, ctx
);
8891 raw_spin_unlock_irq(&ctx
->lock
);
8896 * Free an unexposed, unused context as created by inheritance by
8897 * perf_event_init_task below, used by fork() in case of fail.
8899 * Not all locks are strictly required, but take them anyway to be nice and
8900 * help out with the lockdep assertions.
8902 void perf_event_free_task(struct task_struct
*task
)
8904 struct perf_event_context
*ctx
;
8905 struct perf_event
*event
, *tmp
;
8908 for_each_task_context_nr(ctxn
) {
8909 ctx
= task
->perf_event_ctxp
[ctxn
];
8913 mutex_lock(&ctx
->mutex
);
8915 list_for_each_entry_safe(event
, tmp
, &ctx
->pinned_groups
,
8917 perf_free_event(event
, ctx
);
8919 list_for_each_entry_safe(event
, tmp
, &ctx
->flexible_groups
,
8921 perf_free_event(event
, ctx
);
8923 if (!list_empty(&ctx
->pinned_groups
) ||
8924 !list_empty(&ctx
->flexible_groups
))
8927 mutex_unlock(&ctx
->mutex
);
8933 void perf_event_delayed_put(struct task_struct
*task
)
8937 for_each_task_context_nr(ctxn
)
8938 WARN_ON_ONCE(task
->perf_event_ctxp
[ctxn
]);
8941 struct perf_event
*perf_event_get(unsigned int fd
)
8945 struct perf_event
*event
;
8947 err
= perf_fget_light(fd
, &f
);
8949 return ERR_PTR(err
);
8951 event
= f
.file
->private_data
;
8952 atomic_long_inc(&event
->refcount
);
8958 const struct perf_event_attr
*perf_event_attrs(struct perf_event
*event
)
8961 return ERR_PTR(-EINVAL
);
8963 return &event
->attr
;
8967 * inherit a event from parent task to child task:
8969 static struct perf_event
*
8970 inherit_event(struct perf_event
*parent_event
,
8971 struct task_struct
*parent
,
8972 struct perf_event_context
*parent_ctx
,
8973 struct task_struct
*child
,
8974 struct perf_event
*group_leader
,
8975 struct perf_event_context
*child_ctx
)
8977 enum perf_event_active_state parent_state
= parent_event
->state
;
8978 struct perf_event
*child_event
;
8979 unsigned long flags
;
8982 * Instead of creating recursive hierarchies of events,
8983 * we link inherited events back to the original parent,
8984 * which has a filp for sure, which we use as the reference
8987 if (parent_event
->parent
)
8988 parent_event
= parent_event
->parent
;
8990 child_event
= perf_event_alloc(&parent_event
->attr
,
8993 group_leader
, parent_event
,
8995 if (IS_ERR(child_event
))
8998 if (is_orphaned_event(parent_event
) ||
8999 !atomic_long_inc_not_zero(&parent_event
->refcount
)) {
9000 free_event(child_event
);
9007 * Make the child state follow the state of the parent event,
9008 * not its attr.disabled bit. We hold the parent's mutex,
9009 * so we won't race with perf_event_{en, dis}able_family.
9011 if (parent_state
>= PERF_EVENT_STATE_INACTIVE
)
9012 child_event
->state
= PERF_EVENT_STATE_INACTIVE
;
9014 child_event
->state
= PERF_EVENT_STATE_OFF
;
9016 if (parent_event
->attr
.freq
) {
9017 u64 sample_period
= parent_event
->hw
.sample_period
;
9018 struct hw_perf_event
*hwc
= &child_event
->hw
;
9020 hwc
->sample_period
= sample_period
;
9021 hwc
->last_period
= sample_period
;
9023 local64_set(&hwc
->period_left
, sample_period
);
9026 child_event
->ctx
= child_ctx
;
9027 child_event
->overflow_handler
= parent_event
->overflow_handler
;
9028 child_event
->overflow_handler_context
9029 = parent_event
->overflow_handler_context
;
9032 * Precalculate sample_data sizes
9034 perf_event__header_size(child_event
);
9035 perf_event__id_header_size(child_event
);
9038 * Link it up in the child's context:
9040 raw_spin_lock_irqsave(&child_ctx
->lock
, flags
);
9041 add_event_to_ctx(child_event
, child_ctx
);
9042 raw_spin_unlock_irqrestore(&child_ctx
->lock
, flags
);
9045 * Link this into the parent event's child list
9047 WARN_ON_ONCE(parent_event
->ctx
->parent_ctx
);
9048 mutex_lock(&parent_event
->child_mutex
);
9049 list_add_tail(&child_event
->child_list
, &parent_event
->child_list
);
9050 mutex_unlock(&parent_event
->child_mutex
);
9055 static int inherit_group(struct perf_event
*parent_event
,
9056 struct task_struct
*parent
,
9057 struct perf_event_context
*parent_ctx
,
9058 struct task_struct
*child
,
9059 struct perf_event_context
*child_ctx
)
9061 struct perf_event
*leader
;
9062 struct perf_event
*sub
;
9063 struct perf_event
*child_ctr
;
9065 leader
= inherit_event(parent_event
, parent
, parent_ctx
,
9066 child
, NULL
, child_ctx
);
9068 return PTR_ERR(leader
);
9069 list_for_each_entry(sub
, &parent_event
->sibling_list
, group_entry
) {
9070 child_ctr
= inherit_event(sub
, parent
, parent_ctx
,
9071 child
, leader
, child_ctx
);
9072 if (IS_ERR(child_ctr
))
9073 return PTR_ERR(child_ctr
);
9079 inherit_task_group(struct perf_event
*event
, struct task_struct
*parent
,
9080 struct perf_event_context
*parent_ctx
,
9081 struct task_struct
*child
, int ctxn
,
9085 struct perf_event_context
*child_ctx
;
9087 if (!event
->attr
.inherit
) {
9092 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9095 * This is executed from the parent task context, so
9096 * inherit events that have been marked for cloning.
9097 * First allocate and initialize a context for the
9101 child_ctx
= alloc_perf_context(parent_ctx
->pmu
, child
);
9105 child
->perf_event_ctxp
[ctxn
] = child_ctx
;
9108 ret
= inherit_group(event
, parent
, parent_ctx
,
9118 * Initialize the perf_event context in task_struct
9120 static int perf_event_init_context(struct task_struct
*child
, int ctxn
)
9122 struct perf_event_context
*child_ctx
, *parent_ctx
;
9123 struct perf_event_context
*cloned_ctx
;
9124 struct perf_event
*event
;
9125 struct task_struct
*parent
= current
;
9126 int inherited_all
= 1;
9127 unsigned long flags
;
9130 if (likely(!parent
->perf_event_ctxp
[ctxn
]))
9134 * If the parent's context is a clone, pin it so it won't get
9137 parent_ctx
= perf_pin_task_context(parent
, ctxn
);
9142 * No need to check if parent_ctx != NULL here; since we saw
9143 * it non-NULL earlier, the only reason for it to become NULL
9144 * is if we exit, and since we're currently in the middle of
9145 * a fork we can't be exiting at the same time.
9149 * Lock the parent list. No need to lock the child - not PID
9150 * hashed yet and not running, so nobody can access it.
9152 mutex_lock(&parent_ctx
->mutex
);
9155 * We dont have to disable NMIs - we are only looking at
9156 * the list, not manipulating it:
9158 list_for_each_entry(event
, &parent_ctx
->pinned_groups
, group_entry
) {
9159 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9160 child
, ctxn
, &inherited_all
);
9166 * We can't hold ctx->lock when iterating the ->flexible_group list due
9167 * to allocations, but we need to prevent rotation because
9168 * rotate_ctx() will change the list from interrupt context.
9170 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9171 parent_ctx
->rotate_disable
= 1;
9172 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9174 list_for_each_entry(event
, &parent_ctx
->flexible_groups
, group_entry
) {
9175 ret
= inherit_task_group(event
, parent
, parent_ctx
,
9176 child
, ctxn
, &inherited_all
);
9181 raw_spin_lock_irqsave(&parent_ctx
->lock
, flags
);
9182 parent_ctx
->rotate_disable
= 0;
9184 child_ctx
= child
->perf_event_ctxp
[ctxn
];
9186 if (child_ctx
&& inherited_all
) {
9188 * Mark the child context as a clone of the parent
9189 * context, or of whatever the parent is a clone of.
9191 * Note that if the parent is a clone, the holding of
9192 * parent_ctx->lock avoids it from being uncloned.
9194 cloned_ctx
= parent_ctx
->parent_ctx
;
9196 child_ctx
->parent_ctx
= cloned_ctx
;
9197 child_ctx
->parent_gen
= parent_ctx
->parent_gen
;
9199 child_ctx
->parent_ctx
= parent_ctx
;
9200 child_ctx
->parent_gen
= parent_ctx
->generation
;
9202 get_ctx(child_ctx
->parent_ctx
);
9205 raw_spin_unlock_irqrestore(&parent_ctx
->lock
, flags
);
9206 mutex_unlock(&parent_ctx
->mutex
);
9208 perf_unpin_context(parent_ctx
);
9209 put_ctx(parent_ctx
);
9215 * Initialize the perf_event context in task_struct
9217 int perf_event_init_task(struct task_struct
*child
)
9221 memset(child
->perf_event_ctxp
, 0, sizeof(child
->perf_event_ctxp
));
9222 mutex_init(&child
->perf_event_mutex
);
9223 INIT_LIST_HEAD(&child
->perf_event_list
);
9225 for_each_task_context_nr(ctxn
) {
9226 ret
= perf_event_init_context(child
, ctxn
);
9228 perf_event_free_task(child
);
9236 static void __init
perf_event_init_all_cpus(void)
9238 struct swevent_htable
*swhash
;
9241 for_each_possible_cpu(cpu
) {
9242 swhash
= &per_cpu(swevent_htable
, cpu
);
9243 mutex_init(&swhash
->hlist_mutex
);
9244 INIT_LIST_HEAD(&per_cpu(active_ctx_list
, cpu
));
9248 static void perf_event_init_cpu(int cpu
)
9250 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9252 mutex_lock(&swhash
->hlist_mutex
);
9253 swhash
->online
= true;
9254 if (swhash
->hlist_refcount
> 0) {
9255 struct swevent_hlist
*hlist
;
9257 hlist
= kzalloc_node(sizeof(*hlist
), GFP_KERNEL
, cpu_to_node(cpu
));
9259 rcu_assign_pointer(swhash
->swevent_hlist
, hlist
);
9261 mutex_unlock(&swhash
->hlist_mutex
);
9264 #if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
9265 static void __perf_event_exit_context(void *__info
)
9267 struct remove_event re
= { .detach_group
= true };
9268 struct perf_event_context
*ctx
= __info
;
9271 list_for_each_entry_rcu(re
.event
, &ctx
->event_list
, event_entry
)
9272 __perf_remove_from_context(&re
);
9276 static void perf_event_exit_cpu_context(int cpu
)
9278 struct perf_event_context
*ctx
;
9282 idx
= srcu_read_lock(&pmus_srcu
);
9283 list_for_each_entry_rcu(pmu
, &pmus
, entry
) {
9284 ctx
= &per_cpu_ptr(pmu
->pmu_cpu_context
, cpu
)->ctx
;
9286 mutex_lock(&ctx
->mutex
);
9287 smp_call_function_single(cpu
, __perf_event_exit_context
, ctx
, 1);
9288 mutex_unlock(&ctx
->mutex
);
9290 srcu_read_unlock(&pmus_srcu
, idx
);
9293 static void perf_event_exit_cpu(int cpu
)
9295 struct swevent_htable
*swhash
= &per_cpu(swevent_htable
, cpu
);
9297 perf_event_exit_cpu_context(cpu
);
9299 mutex_lock(&swhash
->hlist_mutex
);
9300 swhash
->online
= false;
9301 swevent_hlist_release(swhash
);
9302 mutex_unlock(&swhash
->hlist_mutex
);
9305 static inline void perf_event_exit_cpu(int cpu
) { }
9309 perf_reboot(struct notifier_block
*notifier
, unsigned long val
, void *v
)
9313 for_each_online_cpu(cpu
)
9314 perf_event_exit_cpu(cpu
);
9320 * Run the perf reboot notifier at the very last possible moment so that
9321 * the generic watchdog code runs as long as possible.
9323 static struct notifier_block perf_reboot_notifier
= {
9324 .notifier_call
= perf_reboot
,
9325 .priority
= INT_MIN
,
9329 perf_cpu_notify(struct notifier_block
*self
, unsigned long action
, void *hcpu
)
9331 unsigned int cpu
= (long)hcpu
;
9333 switch (action
& ~CPU_TASKS_FROZEN
) {
9335 case CPU_UP_PREPARE
:
9336 case CPU_DOWN_FAILED
:
9337 perf_event_init_cpu(cpu
);
9340 case CPU_UP_CANCELED
:
9341 case CPU_DOWN_PREPARE
:
9342 perf_event_exit_cpu(cpu
);
9351 void __init
perf_event_init(void)
9357 perf_event_init_all_cpus();
9358 init_srcu_struct(&pmus_srcu
);
9359 perf_pmu_register(&perf_swevent
, "software", PERF_TYPE_SOFTWARE
);
9360 perf_pmu_register(&perf_cpu_clock
, NULL
, -1);
9361 perf_pmu_register(&perf_task_clock
, NULL
, -1);
9363 perf_cpu_notifier(perf_cpu_notify
);
9364 register_reboot_notifier(&perf_reboot_notifier
);
9366 ret
= init_hw_breakpoint();
9367 WARN(ret
, "hw_breakpoint initialization failed with: %d", ret
);
9369 /* do not patch jump label more than once per second */
9370 jump_label_rate_limit(&perf_sched_events
, HZ
);
9373 * Build time assertion that we keep the data_head at the intended
9374 * location. IOW, validation we got the __reserved[] size right.
9376 BUILD_BUG_ON((offsetof(struct perf_event_mmap_page
, data_head
))
9380 ssize_t
perf_event_sysfs_show(struct device
*dev
, struct device_attribute
*attr
,
9383 struct perf_pmu_events_attr
*pmu_attr
=
9384 container_of(attr
, struct perf_pmu_events_attr
, attr
);
9386 if (pmu_attr
->event_str
)
9387 return sprintf(page
, "%s\n", pmu_attr
->event_str
);
9392 static int __init
perf_event_sysfs_init(void)
9397 mutex_lock(&pmus_lock
);
9399 ret
= bus_register(&pmu_bus
);
9403 list_for_each_entry(pmu
, &pmus
, entry
) {
9404 if (!pmu
->name
|| pmu
->type
< 0)
9407 ret
= pmu_dev_alloc(pmu
);
9408 WARN(ret
, "Failed to register pmu: %s, reason %d\n", pmu
->name
, ret
);
9410 pmu_bus_running
= 1;
9414 mutex_unlock(&pmus_lock
);
9418 device_initcall(perf_event_sysfs_init
);
9420 #ifdef CONFIG_CGROUP_PERF
9421 static struct cgroup_subsys_state
*
9422 perf_cgroup_css_alloc(struct cgroup_subsys_state
*parent_css
)
9424 struct perf_cgroup
*jc
;
9426 jc
= kzalloc(sizeof(*jc
), GFP_KERNEL
);
9428 return ERR_PTR(-ENOMEM
);
9430 jc
->info
= alloc_percpu(struct perf_cgroup_info
);
9433 return ERR_PTR(-ENOMEM
);
9439 static void perf_cgroup_css_free(struct cgroup_subsys_state
*css
)
9441 struct perf_cgroup
*jc
= container_of(css
, struct perf_cgroup
, css
);
9443 free_percpu(jc
->info
);
9447 static int __perf_cgroup_move(void *info
)
9449 struct task_struct
*task
= info
;
9450 perf_cgroup_switch(task
, PERF_CGROUP_SWOUT
| PERF_CGROUP_SWIN
);
9454 static void perf_cgroup_attach(struct cgroup_subsys_state
*css
,
9455 struct cgroup_taskset
*tset
)
9457 struct task_struct
*task
;
9459 cgroup_taskset_for_each(task
, tset
)
9460 task_function_call(task
, __perf_cgroup_move
, task
);
9463 static void perf_cgroup_exit(struct cgroup_subsys_state
*css
,
9464 struct cgroup_subsys_state
*old_css
,
9465 struct task_struct
*task
)
9467 task_function_call(task
, __perf_cgroup_move
, task
);
9470 struct cgroup_subsys perf_event_cgrp_subsys
= {
9471 .css_alloc
= perf_cgroup_css_alloc
,
9472 .css_free
= perf_cgroup_css_free
,
9473 .exit
= perf_cgroup_exit
,
9474 .attach
= perf_cgroup_attach
,
9476 #endif /* CONFIG_CGROUP_PERF */